Merge branch 'master' into DRTVWR-486

174 files changed, 4793 insertions, 1456 deletions

diff --git a/README.md b/README.md
index 729c0ae368..e4078770f3 100644
--- a/README.md
+++ b/README.md
@@ -13,4 +13,3 @@ To download the current default version, visit
 [the download page](https://secondlife.com/support/downloads). For
 even newer versions try
 [the Alternate Viewers page](https://wiki.secondlife.com/wiki/Linden_Lab_Official:Alternate_Viewers)
-
diff --git a/indra/CMakeLists.txt b/indra/CMakeLists.txt
index 4b39bfe332..53e5d7b6a5 100644
--- a/indra/CMakeLists.txt
+++ b/indra/CMakeLists.txt
@@ -40,7 +40,7 @@ add_subdirectory(${LIBS_OPEN_PREFIX}llmath)
 add_subdirectory(${LIBS_OPEN_PREFIX}llmessage)
 add_subdirectory(${LIBS_OPEN_PREFIX}llprimitive)
 add_subdirectory(${LIBS_OPEN_PREFIX}llrender)
-add_subdirectory(${LIBS_OPEN_PREFIX}llfilesystem)
+add_subdirectory(${LIBS_OPEN_PREFIX}llvfs)
 add_subdirectory(${LIBS_OPEN_PREFIX}llwindow)
 add_subdirectory(${LIBS_OPEN_PREFIX}llxml)
 
diff --git a/indra/cmake/00-Common.cmake b/indra/cmake/00-Common.cmake
index f4071793d5..8aea50e02b 100644
--- a/indra/cmake/00-Common.cmake
+++ b/indra/cmake/00-Common.cmake
@@ -66,10 +66,11 @@ if (WINDOWS)
   # CP changed to only append the flag for 32bit builds - on 64bit builds,
   # locally at least, the build output is spammed with 1000s of 'D9002'
   # warnings about this switch being ignored.
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")  
   if( ADDRESS_SIZE EQUAL 32 )
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /p:PreferredToolArchitecture=x64")  
   endif()
+
   set(CMAKE_CXX_FLAGS_RELWITHDEBINFO 
       "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /Zo"
       CACHE STRING "C++ compiler release-with-debug options" FORCE)
diff --git a/indra/cmake/CMakeLists.txt b/indra/cmake/CMakeLists.txt
index 352dfc0641..a17e37cd32 100644
--- a/indra/cmake/CMakeLists.txt
+++ b/indra/cmake/CMakeLists.txt
@@ -69,7 +69,7 @@ set(cmake_SOURCE_FILES
     LLSharedLibs.cmake
     LLTestCommand.cmake
     LLUI.cmake
-    LLFileSystem.cmake
+    LLVFS.cmake
     LLWindow.cmake
     LLXML.cmake
     Linking.cmake
diff --git a/indra/cmake/LLFileSystem.cmake b/indra/cmake/LLFileSystem.cmake
deleted file mode 100644
index 2e6c42c30c..0000000000
--- a/indra/cmake/LLFileSystem.cmake
+++ /dev/null
@@ -1,7 +0,0 @@
-# -*- cmake -*-
-
-set(LLFILESYSTEM_INCLUDE_DIRS
-    ${LIBS_OPEN_DIR}/llfilesystem
-    )
-
-set(LLFILESYSTEM_LIBRARIES llfilesystem)
diff --git a/indra/cmake/LLVFS.cmake b/indra/cmake/LLVFS.cmake
new file mode 100644
index 0000000000..0fe87cdea6
--- /dev/null
+++ b/indra/cmake/LLVFS.cmake
@@ -0,0 +1,7 @@
+# -*- cmake -*-
+
+set(LLVFS_INCLUDE_DIRS
+    ${LIBS_OPEN_DIR}/llvfs
+    )
+
+set(LLVFS_LIBRARIES llvfs)
diff --git a/indra/integration_tests/llimage_libtest/CMakeLists.txt b/indra/integration_tests/llimage_libtest/CMakeLists.txt
index bd59f57e49..5787d4d600 100644
--- a/indra/integration_tests/llimage_libtest/CMakeLists.txt
+++ b/indra/integration_tests/llimage_libtest/CMakeLists.txt
@@ -10,11 +10,11 @@ include(LLImage)
 include(LLMath)
 include(LLImageJ2COJ) 
 include(LLKDU)
-include(LLFileSystem)
+include(LLVFS)
 
 include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLIMAGE_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     )
@@ -66,7 +66,7 @@ endif (DARWIN)
 target_link_libraries(llimage_libtest
     ${LEGACY_STDIO_LIBS}
     ${LLCOMMON_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLIMAGE_LIBRARIES}
     ${LLKDU_LIBRARIES}
diff --git a/indra/integration_tests/llui_libtest/CMakeLists.txt b/indra/integration_tests/llui_libtest/CMakeLists.txt
index d7706e73b2..1cec660eb0 100644
--- a/indra/integration_tests/llui_libtest/CMakeLists.txt
+++ b/indra/integration_tests/llui_libtest/CMakeLists.txt
@@ -16,7 +16,7 @@ include(LLMessage)
 include(LLRender)
 include(LLWindow)
 include(LLUI)
-include(LLFileSystem)
+include(LLVFS)        # ugh, needed for LLDir
 include(LLXML)
 include(Hunspell)
 include(Linking)
@@ -29,7 +29,7 @@ include_directories(
     ${LLMATH_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
     ${LLUI_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     ${LIBS_PREBUILD_DIR}/include/hunspell
diff --git a/indra/linux_crash_logger/CMakeLists.txt b/indra/linux_crash_logger/CMakeLists.txt
index aa82ed12cc..d789c850a0 100644
--- a/indra/linux_crash_logger/CMakeLists.txt
+++ b/indra/linux_crash_logger/CMakeLists.txt
@@ -9,7 +9,7 @@ include(LLCommon)
 include(LLCrashLogger)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 include(Linking)
 include(UI)
@@ -21,7 +21,7 @@ include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLCRASHLOGGER_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     ${FREETYPE_INCLUDE_DIRS}
     )
@@ -62,9 +62,10 @@ set(LIBRT_LIBRARY rt)
 
 target_link_libraries(linux-crash-logger
     ${LLCRASHLOGGER_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOREHTTP_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
diff --git a/indra/llappearance/CMakeLists.txt b/indra/llappearance/CMakeLists.txt
index 268849ad74..20eb4678dd 100644
--- a/indra/llappearance/CMakeLists.txt
+++ b/indra/llappearance/CMakeLists.txt
@@ -11,7 +11,7 @@ include(LLMath)
 include(LLMessage)
 include(LLCoreHttp)
 include(LLRender)
-include(LLFileSystem)
+include(LLVFS)
 include(LLWindow)
 include(LLXML)
 include(Linking)
@@ -23,7 +23,7 @@ include_directories(
     ${LLINVENTORY_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     )
@@ -83,7 +83,7 @@ target_link_libraries(llappearance
     ${LLINVENTORY_LIBRARIES}
     ${LLIMAGE_LIBRARIES}
     ${LLRENDER_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMATH_LIBRARIES}
@@ -100,7 +100,7 @@ if (BUILD_HEADLESS)
       ${LLINVENTORY_LIBRARIES}
       ${LLIMAGE_LIBRARIES}
       ${LLRENDERHEADLESS_LIBRARIES}
-      ${LLFILESYSTEM_LIBRARIES}
+      ${LLVFS_LIBRARIES}
       ${LLMATH_LIBRARIES}
       ${LLXML_LIBRARIES}
       ${LLMATH_LIBRARIES}
@@ -109,3 +109,15 @@ if (BUILD_HEADLESS)
       ${LLCOMMON_LIBRARIES}
       )
 endif (BUILD_HEADLESS)
+
+#add unit tests
+#if (LL_TESTS)
+#    INCLUDE(LLAddBuildTest)
+#    SET(llappearance_TEST_SOURCE_FILES
+#      # no real unit tests yet!
+#      )
+#    LL_ADD_PROJECT_UNIT_TESTS(llappearance "${llappearance_TEST_SOURCE_FILES}")
+
+    #set(TEST_DEBUG on)
+#    set(test_libs llappearance ${LLCOMMON_LIBRARIES})
+#endif (LL_TESTS)
diff --git a/indra/llappearance/lltexlayer.cpp b/indra/llappearance/lltexlayer.cpp
index a4600069ce..e5039141de 100644
--- a/indra/llappearance/lltexlayer.cpp
+++ b/indra/llappearance/lltexlayer.cpp
@@ -33,6 +33,8 @@
 #include "llimagej2c.h"
 #include "llimagetga.h"
 #include "lldir.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "lltexlayerparams.h"
 #include "lltexturemanagerbridge.h"
 #include "lllocaltextureobject.h"
diff --git a/indra/llaudio/CMakeLists.txt b/indra/llaudio/CMakeLists.txt
index 92a5cfe22f..558ede7bf6 100644
--- a/indra/llaudio/CMakeLists.txt
+++ b/indra/llaudio/CMakeLists.txt
@@ -9,14 +9,14 @@ include(OPENAL)
 include(LLCommon)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 
 include_directories(
     ${LLAUDIO_INCLUDE_DIRS}
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLMESSAGE_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${OGG_INCLUDE_DIRS}
     ${VORBISENC_INCLUDE_DIRS}
     ${VORBISFILE_INCLUDE_DIRS}
@@ -86,7 +86,7 @@ target_link_libraries(
     ${LLCOMMON_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${VORBISENC_LIBRARIES}
     ${VORBISFILE_LIBRARIES}
     ${VORBIS_LIBRARIES}
diff --git a/indra/llaudio/llaudiodecodemgr.cpp b/indra/llaudio/llaudiodecodemgr.cpp
index ff0aa6e76e..e7db84f6ab 100644
--- a/indra/llaudio/llaudiodecodemgr.cpp
+++ b/indra/llaudio/llaudiodecodemgr.cpp
@@ -29,7 +29,7 @@
 
 #include "llaudioengine.h"
 #include "lllfsthread.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llstring.h"
 #include "lldir.h"
 #include "llendianswizzle.h"
@@ -90,17 +90,19 @@ protected:
 	LLUUID mUUID;
 
 	std::vector<U8> mWAVBuffer;
+#if !defined(USE_WAV_VFILE)
 	std::string mOutFilename;
 	LLLFSThread::handle_t mFileHandle;
+#endif
 	
-	LLFileSystem *mInFilep;
+	LLVFile *mInFilep;
 	OggVorbis_File mVF;
 	S32 mCurrentSection;
 };
 
-size_t cache_read(void *ptr, size_t size, size_t nmemb, void *datasource)
+size_t vfs_read(void *ptr, size_t size, size_t nmemb, void *datasource)
 {
-	LLFileSystem *file = (LLFileSystem *)datasource;
+	LLVFile *file = (LLVFile *)datasource;
 
 	if (file->read((U8*)ptr, (S32)(size * nmemb)))	/*Flawfinder: ignore*/
 	{
@@ -113,11 +115,11 @@ size_t cache_read(void *ptr, size_t size, size_t nmemb, void *datasource)
 	}
 }
 
-S32 cache_seek(void *datasource, ogg_int64_t offset, S32 whence)
+S32 vfs_seek(void *datasource, ogg_int64_t offset, S32 whence)
 {
-	LLFileSystem *file = (LLFileSystem *)datasource;
+	LLVFile *file = (LLVFile *)datasource;
 
-	// cache has 31-bit files
+	// vfs has 31-bit files
 	if (offset > S32_MAX)
 	{
 		return -1;
@@ -135,7 +137,7 @@ S32 cache_seek(void *datasource, ogg_int64_t offset, S32 whence)
 		origin = -1;
 		break;
 	default:
-		LL_ERRS("AudioEngine") << "Invalid whence argument to cache_seek" << LL_ENDL;
+		LL_ERRS("AudioEngine") << "Invalid whence argument to vfs_seek" << LL_ENDL;
 		return -1;
 	}
 
@@ -149,16 +151,16 @@ S32 cache_seek(void *datasource, ogg_int64_t offset, S32 whence)
 	}
 }
 
-S32 cache_close (void *datasource)
+S32 vfs_close (void *datasource)
 {
-	LLFileSystem *file = (LLFileSystem *)datasource;
+	LLVFile *file = (LLVFile *)datasource;
 	delete file;
 	return 0;
 }
 
-long cache_tell (void *datasource)
+long vfs_tell (void *datasource)
 {
-	LLFileSystem *file = (LLFileSystem *)datasource;
+	LLVFile *file = (LLVFile *)datasource;
 	return file->tell();
 }
 
@@ -170,10 +172,11 @@ LLVorbisDecodeState::LLVorbisDecodeState(const LLUUID &uuid, const std::string &
 	mUUID = uuid;
 	mInFilep = NULL;
 	mCurrentSection = 0;
+#if !defined(USE_WAV_VFILE)
 	mOutFilename = out_filename;
 	mFileHandle = LLLFSThread::nullHandle();
-
-    // No default value for mVF, it's an ogg structure?
+#endif
+	// No default value for mVF, it's an ogg structure?
 	// Hey, let's zero it anyway, for predictability.
 	memset(&mVF, 0, sizeof(mVF));
 }
@@ -190,15 +193,15 @@ LLVorbisDecodeState::~LLVorbisDecodeState()
 
 BOOL LLVorbisDecodeState::initDecode()
 {
-	ov_callbacks cache_callbacks;
-	cache_callbacks.read_func = cache_read;
-	cache_callbacks.seek_func = cache_seek;
-	cache_callbacks.close_func = cache_close;
-	cache_callbacks.tell_func = cache_tell;
+	ov_callbacks vfs_callbacks;
+	vfs_callbacks.read_func = vfs_read;
+	vfs_callbacks.seek_func = vfs_seek;
+	vfs_callbacks.close_func = vfs_close;
+	vfs_callbacks.tell_func = vfs_tell;
 
 	LL_DEBUGS("AudioEngine") << "Initing decode from vfile: " << mUUID << LL_ENDL;
 
-	mInFilep = new LLFileSystem(mUUID, LLAssetType::AT_SOUND);
+	mInFilep = new LLVFile(gVFS, mUUID, LLAssetType::AT_SOUND);
 	if (!mInFilep || !mInFilep->getSize())
 	{
 		LL_WARNS("AudioEngine") << "unable to open vorbis source vfile for reading" << LL_ENDL;
@@ -207,7 +210,7 @@ BOOL LLVorbisDecodeState::initDecode()
 		return FALSE;
 	}
 
-	S32 r = ov_open_callbacks(mInFilep, &mVF, NULL, 0, cache_callbacks);
+	S32 r = ov_open_callbacks(mInFilep, &mVF, NULL, 0, vfs_callbacks);
 	if(r < 0) 
 	{
 		LL_WARNS("AudioEngine") << r << " Input to vorbis decode does not appear to be an Ogg bitstream: " << mUUID << LL_ENDL;
@@ -367,7 +370,7 @@ BOOL LLVorbisDecodeState::decodeSection()
 {
 	if (!mInFilep)
 	{
-		LL_WARNS("AudioEngine") << "No cache file to decode in vorbis!" << LL_ENDL;
+		LL_WARNS("AudioEngine") << "No VFS file to decode in vorbis!" << LL_ENDL;
 		return TRUE;
 	}
 	if (mDone)
@@ -417,7 +420,9 @@ BOOL LLVorbisDecodeState::finishDecode()
 		return TRUE; // We've finished
 	}
 
+#if !defined(USE_WAV_VFILE)	
 	if (mFileHandle == LLLFSThread::nullHandle())
+#endif
 	{
 		ov_clear(&mVF);
   
@@ -490,9 +495,11 @@ BOOL LLVorbisDecodeState::finishDecode()
 			mValid = FALSE;
 			return TRUE; // we've finished
 		}
+#if !defined(USE_WAV_VFILE)
 		mBytesRead = -1;
 		mFileHandle = LLLFSThread::sLocal->write(mOutFilename, &mWAVBuffer[0], 0, mWAVBuffer.size(),
 							 new WriteResponder(this));
+#endif
 	}
 
 	if (mFileHandle != LLLFSThread::nullHandle())
@@ -514,6 +521,11 @@ BOOL LLVorbisDecodeState::finishDecode()
 	
 	mDone = TRUE;
 
+#if defined(USE_WAV_VFILE)
+	// write the data.
+	LLVFile output(gVFS, mUUID, LLAssetType::AT_SOUND_WAV);
+	output.write(&mWAVBuffer[0], mWAVBuffer.size());
+#endif
 	LL_DEBUGS("AudioEngine") << "Finished decode for " << getUUID() << LL_ENDL;
 
 	return TRUE;
@@ -523,7 +535,7 @@ void LLVorbisDecodeState::flushBadFile()
 {
 	if (mInFilep)
 	{
-		LL_WARNS("AudioEngine") << "Flushing bad vorbis file from cache for " << mUUID << LL_ENDL;
+		LL_WARNS("AudioEngine") << "Flushing bad vorbis file from VFS for " << mUUID << LL_ENDL;
 		mInFilep->remove();
 	}
 }
diff --git a/indra/llaudio/llaudiodecodemgr.h b/indra/llaudio/llaudiodecodemgr.h
index ceaff3f2d8..8228e20e8c 100644
--- a/indra/llaudio/llaudiodecodemgr.h
+++ b/indra/llaudio/llaudiodecodemgr.h
@@ -33,6 +33,7 @@
 #include "llassettype.h"
 #include "llframetimer.h"
 
+class LLVFS;
 class LLVorbisDecodeState;
 
 class LLAudioDecodeMgr
diff --git a/indra/llaudio/llaudioengine.cpp b/indra/llaudio/llaudioengine.cpp
index d35f249973..1d447f32ae 100644
--- a/indra/llaudio/llaudioengine.cpp
+++ b/indra/llaudio/llaudioengine.cpp
@@ -35,7 +35,7 @@
 
 #include "sound_ids.h"  // temporary hack for min/max distances
 
-#include "llfilesystem.h"
+#include "llvfs.h"
 #include "lldir.h"
 #include "llaudiodecodemgr.h"
 #include "llassetstorage.h"
@@ -684,9 +684,13 @@ bool LLAudioEngine::preloadSound(const LLUUID &uuid)
 		return true;
 	}
 
+	// At some point we need to have the audio/asset system check the static VFS
+	// before it goes off and fetches stuff from the server.
+	//LL_WARNS() << "Used internal preload for non-local sound" << LL_ENDL;
 	return false;
 }
 
+
 bool LLAudioEngine::isWindEnabled()
 {
 	return mEnableWind;
@@ -1014,12 +1018,13 @@ bool LLAudioEngine::hasDecodedFile(const LLUUID &uuid)
 
 bool LLAudioEngine::hasLocalFile(const LLUUID &uuid)
 {
-	// See if it's in the cache.
-	bool have_local = LLFileSystem::getExists(uuid, LLAssetType::AT_SOUND);
-	LL_DEBUGS("AudioEngine") << "sound uuid " << uuid << " exists in cache" << LL_ENDL;
+	// See if it's in the VFS.
+	bool have_local = gVFS->getExists(uuid, LLAssetType::AT_SOUND);
+	LL_DEBUGS("AudioEngine") << "sound uuid "<<uuid<<" exists in VFS"<<LL_ENDL;
 	return have_local;
 }
 
+
 void LLAudioEngine::startNextTransfer()
 {
 	//LL_INFOS() << "LLAudioEngine::startNextTransfer()" << LL_ENDL;
@@ -1220,7 +1225,7 @@ void LLAudioEngine::startNextTransfer()
 
 
 // static
-void LLAudioEngine::assetCallback(const LLUUID &uuid, LLAssetType::EType type, void *user_data, S32 result_code, LLExtStat ext_status)
+void LLAudioEngine::assetCallback(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type, void *user_data, S32 result_code, LLExtStat ext_status)
 {
 	if (!gAudiop)
 	{
diff --git a/indra/llaudio/llaudioengine.h b/indra/llaudio/llaudioengine.h
index 577b36d667..97674f15f7 100644
--- a/indra/llaudio/llaudioengine.h
+++ b/indra/llaudio/llaudioengine.h
@@ -50,6 +50,15 @@ const F32 DEFAULT_MIN_DISTANCE = 2.0f;
 #define MAX_CHANNELS 30
 #define MAX_BUFFERS 40	// Some extra for preloading, maybe?
 
+// This define is intended to allow us to switch from os based wav
+// file loading to vfs based wav file loading. The problem is that I
+// am unconvinced that the LLWaveFile works for loading sounds from
+// memory. So, until that is fixed up, changed, whatever, this remains
+// undefined.
+//#define USE_WAV_VFILE
+
+class LLVFS;
+
 class LLAudioSource;
 class LLAudioData;
 class LLAudioChannel;
@@ -58,9 +67,11 @@ class LLAudioBuffer;
 class LLStreamingAudioInterface;
 struct SoundData;
 
+
 //
 //  LLAudioEngine definition
 //
+
 class LLAudioEngine 
 {
 	friend class LLAudioChannelOpenAL; // bleh. channel needs some listener methods.
@@ -171,7 +182,7 @@ public:
 
 	// Asset callback when we're retrieved a sound from the asset server.
 	void startNextTransfer();
-	static void assetCallback(const LLUUID &uuid, LLAssetType::EType type, void *user_data, S32 result_code, LLExtStat ext_status);
+	static void assetCallback(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type, void *user_data, S32 result_code, LLExtStat ext_status);
 
 	friend class LLPipeline; // For debugging
 public:
diff --git a/indra/llcharacter/CMakeLists.txt b/indra/llcharacter/CMakeLists.txt
index d90ffb5543..a17a5b0aa6 100644
--- a/indra/llcharacter/CMakeLists.txt
+++ b/indra/llcharacter/CMakeLists.txt
@@ -6,14 +6,14 @@ include(00-Common)
 include(LLCommon)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 
 include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLMESSAGE_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     )
 include_directories(SYSTEM
@@ -85,6 +85,18 @@ target_link_libraries(
     ${LLCOMMON_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
     )
+
+
+# Add tests
+#if (LL_TESTS)
+#    include(LLAddBuildTest)
+#    # UNIT TESTS
+#    SET(llcharacter_TEST_SOURCE_FILES
+#      lljoint.cpp
+#      )
+#    LL_ADD_PROJECT_UNIT_TESTS(llcharacter "${llcharacter_TEST_SOURCE_FILES}")
+#endif (LL_TESTS)
+
diff --git a/indra/llcharacter/llkeyframefallmotion.cpp b/indra/llcharacter/llkeyframefallmotion.cpp
index 7842f0e5fb..60ab2e9929 100644
--- a/indra/llcharacter/llkeyframefallmotion.cpp
+++ b/indra/llcharacter/llkeyframefallmotion.cpp
@@ -70,11 +70,6 @@ LLMotion::LLMotionInitStatus LLKeyframeFallMotion::onInitialize(LLCharacter *cha
 	// load keyframe data, setup pose and joint states
 	LLMotion::LLMotionInitStatus result = LLKeyframeMotion::onInitialize(character);
 
-	if (result != LLMotion::STATUS_SUCCESS)
-	{
-		return result;
-	}
-
 	for (U32 jm=0; jm<mJointMotionList->getNumJointMotions(); jm++)
 	{
 		if (!mJointStates[jm]->getJoint())
diff --git a/indra/llcharacter/llkeyframemotion.cpp b/indra/llcharacter/llkeyframemotion.cpp
index fe9de30f0a..cde38c8091 100644
--- a/indra/llcharacter/llkeyframemotion.cpp
+++ b/indra/llcharacter/llkeyframemotion.cpp
@@ -39,13 +39,14 @@
 #include "llendianswizzle.h"
 #include "llkeyframemotion.h"
 #include "llquantize.h"
+#include "llvfile.h"
 #include "m3math.h"
 #include "message.h"
-#include "llfilesystem.h"
 
 //-----------------------------------------------------------------------------
 // Static Definitions
 //-----------------------------------------------------------------------------
+LLVFS*				LLKeyframeMotion::sVFS = NULL;
 LLKeyframeDataCache::keyframe_data_map_t	LLKeyframeDataCache::sKeyframeDataMap;
 
 //-----------------------------------------------------------------------------
@@ -514,7 +515,7 @@ LLMotion::LLMotionInitStatus LLKeyframeMotion::onInitialize(LLCharacter *charact
 		return STATUS_SUCCESS;
 	default:
 		// we don't know what state the asset is in yet, so keep going
-		// check keyframe cache first then file cache then asset request
+		// check keyframe cache first then static vfs then asset request
 		break;
 	}
 
@@ -558,8 +559,13 @@ LLMotion::LLMotionInitStatus LLKeyframeMotion::onInitialize(LLCharacter *charact
 	U8 *anim_data;
 	S32 anim_file_size;
 
+	if (!sVFS)
+	{
+		LL_ERRS() << "Must call LLKeyframeMotion::setVFS() first before loading a keyframe file!" << LL_ENDL;
+	}
+
 	BOOL success = FALSE;
-	LLFileSystem* anim_file = new LLFileSystem(mID, LLAssetType::AT_ANIMATION);
+	LLVFile* anim_file = new LLVFile(sVFS, mID, LLAssetType::AT_ANIMATION);
 	if (!anim_file || !anim_file->getSize())
 	{
 		delete anim_file;
@@ -2290,9 +2296,10 @@ void LLKeyframeMotion::setLoopOut(F32 out_point)
 //-----------------------------------------------------------------------------
 // onLoadComplete()
 //-----------------------------------------------------------------------------
-void LLKeyframeMotion::onLoadComplete(const LLUUID& asset_uuid,
-									  LLAssetType::EType type,
-									  void* user_data, S32 status, LLExtStat ext_status)
+void LLKeyframeMotion::onLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
+									   LLAssetType::EType type,
+									   void* user_data, S32 status, LLExtStat ext_status)
 {
 	LLUUID* id = (LLUUID*)user_data;
 		
@@ -2324,7 +2331,7 @@ void LLKeyframeMotion::onLoadComplete(const LLUUID& asset_uuid,
 				// asset already loaded
 				return;
 			}
-			LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+			LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 			S32 size = file.getSize();
 			
 			U8* buffer = new U8[size];
diff --git a/indra/llcharacter/llkeyframemotion.h b/indra/llcharacter/llkeyframemotion.h
index d640556090..15c5c7c6c0 100644
--- a/indra/llcharacter/llkeyframemotion.h
+++ b/indra/llcharacter/llkeyframemotion.h
@@ -44,6 +44,7 @@
 #include "llbvhconsts.h"
 
 class LLKeyframeDataCache;
+class LLVFS;
 class LLDataPacker;
 
 #define MIN_REQUIRED_PIXEL_AREA_KEYFRAME (40.f)
@@ -140,7 +141,10 @@ public:
 
 	virtual void setStopTime(F32 time);
 
-	static void onLoadComplete(const LLUUID& asset_uuid,
+	static void setVFS(LLVFS* vfs) { sVFS = vfs; }
+
+	static void onLoadComplete(LLVFS *vfs,
+							   const LLUUID& asset_uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 
@@ -412,7 +416,13 @@ public:
 		U32 getNumJointMotions() const { return mJointMotionArray.size(); }
 	};
 
+
 protected:
+	static LLVFS*				sVFS;
+
+	//-------------------------------------------------------------------------
+	// Member Data
+	//-------------------------------------------------------------------------
 	JointMotionList*				mJointMotionList;
 	std::vector<LLPointer<LLJointState> > mJointStates;
 	LLJoint*						mPelvisp;
diff --git a/indra/llcommon/llerror.cpp b/indra/llcommon/llerror.cpp
index 6e8b9efaf7..f876b8ee4a 100644
--- a/indra/llcommon/llerror.cpp
+++ b/indra/llcommon/llerror.cpp
@@ -194,64 +194,23 @@ namespace {
         {
             return LLError::getEnabledLogTypesMask() & 0x04;
         }
-
-        LL_FORCE_INLINE std::string createBoldANSI()
-        {
-            std::string ansi_code;
-            ansi_code += '\033';
-            ansi_code += "[";
-            ansi_code += "1";
-            ansi_code += "m";
-
-            return ansi_code;
-        }
-
-        LL_FORCE_INLINE std::string createResetANSI()
-        {
-            std::string ansi_code;
-            ansi_code += '\033';
-            ansi_code += "[";
-            ansi_code += "0";
-            ansi_code += "m";
-
-            return ansi_code;
-        }
-
+        
         LL_FORCE_INLINE std::string createANSI(const std::string& color)
         {
             std::string ansi_code;
-            ansi_code += '\033';
-            ansi_code += "[";
-            ansi_code += "38;5;";
-            ansi_code += color;
+            ansi_code  += '\033';
+            ansi_code  += "[";
+            ansi_code  += color;
             ansi_code += "m";
-
             return ansi_code;
         }
 
 		virtual void recordMessage(LLError::ELevel level,
 					   const std::string& message) override
 		{
-            // The default colors for error, warn and debug are now a bit more pastel
-            // and easier to read on the default (black) terminal background but you 
-            // now have the option to set the color of each via an environment variables:
-            // LL_ANSI_ERROR_COLOR_CODE (default is red)
-            // LL_ANSI_WARN_COLOR_CODE  (default is blue)
-            // LL_ANSI_DEBUG_COLOR_CODE (default is magenta)
-            // The list of color codes can be found in many places but I used this page:
-            // https://www.lihaoyi.com/post/BuildyourownCommandLinewithANSIescapecodes.html#256-colors
-            // (Note: you may need to restart Visual Studio to pick environment changes)
-            char* val = nullptr;
-            std::string s_ansi_error_code = "160";
-            if ((val = getenv("LL_ANSI_ERROR_COLOR_CODE")) != nullptr) s_ansi_error_code = std::string(val);
-            std::string s_ansi_warn_code = "33";
-            if ((val = getenv("LL_ANSI_WARN_COLOR_CODE")) != nullptr) s_ansi_warn_code = std::string(val);
-            std::string s_ansi_debug_code = "177";
-            if ((val = getenv("LL_ANSI_DEBUG_COLOR_CODE")) != nullptr) s_ansi_debug_code = std::string(val);
-
-            static std::string s_ansi_error = createANSI(s_ansi_error_code); // default is red
-            static std::string s_ansi_warn  = createANSI(s_ansi_warn_code); // default is blue
-            static std::string s_ansi_debug = createANSI(s_ansi_debug_code); // default is magenta
+            static std::string s_ansi_error = createANSI("31"); // red
+            static std::string s_ansi_warn  = createANSI("34"); // blue
+            static std::string s_ansi_debug = createANSI("35"); // magenta
 
 			if (mUseANSI)
 			{
@@ -270,11 +229,11 @@ namespace {
 
         LL_FORCE_INLINE void writeANSI(const std::string& ansi_code, const std::string& message)
 		{
-            static std::string s_ansi_bold = createBoldANSI();  // bold text
-            static std::string s_ansi_reset = createResetANSI();  // reset
+            static std::string s_ansi_bold  = createANSI("1");  // bold
+            static std::string s_ansi_reset = createANSI("0");  // reset
 			// ANSI color code escape sequence, message, and reset in one fprintf call
             // Default all message levels to bold so we can distinguish our own messages from those dumped by subprocesses and libraries.
-			fprintf(stderr, "%s%s\n%s", ansi_code.c_str(), message.c_str(), s_ansi_reset.c_str() );
+			fprintf(stderr, "%s%s%s\n%s", s_ansi_bold.c_str(), ansi_code.c_str(), message.c_str(), s_ansi_reset.c_str() );
 		}
 
 		static bool checkANSI(void)
diff --git a/indra/llcrashlogger/CMakeLists.txt b/indra/llcrashlogger/CMakeLists.txt
index d70a1e0fb0..da23b46b7b 100644
--- a/indra/llcrashlogger/CMakeLists.txt
+++ b/indra/llcrashlogger/CMakeLists.txt
@@ -7,7 +7,7 @@ include(LLCoreHttp)
 include(LLCommon)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 
 include_directories(
@@ -15,7 +15,7 @@ include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLMESSAGE_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     )
 include_directories(SYSTEM
diff --git a/indra/llcrashlogger/llcrashlock.h b/indra/llcrashlogger/llcrashlock.h
index 60b060b736..cde183272f 100644
--- a/indra/llcrashlogger/llcrashlock.h
+++ b/indra/llcrashlogger/llcrashlock.h
@@ -1,5 +1,5 @@
 /** 
- * @file llcrashlock.h
+ * @file llpidlock.h
  * @brief Maintainence of disk locking files for crash reporting
  *
  * $LicenseInfo:firstyear=2001&license=viewerlgpl$
diff --git a/indra/llfilesystem/lldiskcache.cpp b/indra/llfilesystem/lldiskcache.cpp
deleted file mode 100644
index c9f7684b5a..0000000000
--- a/indra/llfilesystem/lldiskcache.cpp
+++ /dev/null
@@ -1,327 +0,0 @@
-/**
- * @file lldiskcache.cpp
- * @brief The disk cache implementation.
- *
- * Note: Rather than keep the top level function comments up
- * to date in both the source and header files, I elected to
- * only have explicit comments about each function and variable
- * in the header - look there for details. The same is true for
- * description of how this code is supposed to work.
- *
- * $LicenseInfo:firstyear=2009&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2020, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#include "linden_common.h"
-#include "llassettype.h"
-#include "lldir.h"
-#include <boost/filesystem.hpp>
-#include <boost/range/iterator_range.hpp>
-#include <chrono>
-
-#include "lldiskcache.h"
-
-LLDiskCache::LLDiskCache(const std::string cache_dir,
-                         const int max_size_bytes,
-                         const bool enable_cache_debug_info) :
-    mCacheDir(cache_dir),
-    mMaxSizeBytes(max_size_bytes),
-    mEnableCacheDebugInfo(enable_cache_debug_info)
-{
-    mCacheFilenamePrefix = "sl_cache";
-
-    LLFile::mkdir(cache_dir);
-}
-
-void LLDiskCache::purge()
-{
-    if (mEnableCacheDebugInfo)
-    {
-        LL_INFOS() << "Total dir size before purge is " << dirFileSize(mCacheDir) << LL_ENDL;
-    }
-
-    auto start_time = std::chrono::high_resolution_clock::now();
-
-    typedef std::pair<std::time_t, std::pair<uintmax_t, std::string>> file_info_t;
-    std::vector<file_info_t> file_info;
-
-#if LL_WINDOWS
-    std::wstring cache_path(utf8str_to_utf16str(mCacheDir));
-#else
-    std::string cache_path(mCacheDir);
-#endif
-    if (boost::filesystem::is_directory(cache_path))
-    {
-        for (auto& entry : boost::make_iterator_range(boost::filesystem::directory_iterator(cache_path), {}))
-        {
-            if (boost::filesystem::is_regular_file(entry))
-            {
-                if (entry.path().string().find(mCacheFilenamePrefix) != std::string::npos)
-                {
-                    uintmax_t file_size = boost::filesystem::file_size(entry);
-                    const std::string file_path = entry.path().string();
-                    const std::time_t file_time = boost::filesystem::last_write_time(entry);
-
-                    file_info.push_back(file_info_t(file_time, { file_size, file_path }));
-                }
-            }
-        }
-    }
-
-    std::sort(file_info.begin(), file_info.end(), [](file_info_t& x, file_info_t& y)
-    {
-        return x.first > y.first;
-    });
-
-    LL_INFOS() << "Purging cache to a maximum of " << mMaxSizeBytes << " bytes" << LL_ENDL;
-
-    uintmax_t file_size_total = 0;
-    for (file_info_t& entry : file_info)
-    {
-        file_size_total += entry.second.first;
-
-        std::string action = "";
-        if (file_size_total > mMaxSizeBytes)
-        {
-            action = "DELETE:";
-            boost::filesystem::remove(entry.second.second);
-        }
-        else
-        {
-            action = "  KEEP:";
-        }
-
-        if (mEnableCacheDebugInfo)
-        {
-            // have to do this because of LL_INFO/LL_END weirdness
-            std::ostringstream line;
-
-            line << action << "  ";
-            line << entry.first << "  ";
-            line << entry.second.first << "  ";
-            line << entry.second.second;
-            line << " (" << file_size_total << "/" << mMaxSizeBytes << ")";
-            LL_INFOS() << line.str() << LL_ENDL;
-        }
-    }
-
-    if (mEnableCacheDebugInfo)
-    {
-        auto end_time = std::chrono::high_resolution_clock::now();
-        auto execute_time = std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time).count();
-        LL_INFOS() << "Total dir size after purge is " << dirFileSize(mCacheDir) << LL_ENDL;
-        LL_INFOS() << "Cache purge took " << execute_time << " ms to execute for " << file_info.size() << " files" << LL_ENDL;
-    }
-}
-
-const std::string LLDiskCache::assetTypeToString(LLAssetType::EType at)
-{
-    /**
-     * Make use of the handy C++17  feature that allows
-     * for inline initialization of an std::map<>
-     */
-    typedef std::map<LLAssetType::EType, std::string> asset_type_to_name_t;
-    asset_type_to_name_t asset_type_to_name =
-    {
-        { LLAssetType::AT_TEXTURE, "TEXTURE" },
-        { LLAssetType::AT_SOUND, "SOUND" },
-        { LLAssetType::AT_CALLINGCARD, "CALLINGCARD" },
-        { LLAssetType::AT_LANDMARK, "LANDMARK" },
-        { LLAssetType::AT_SCRIPT, "SCRIPT" },
-        { LLAssetType::AT_CLOTHING, "CLOTHING" },
-        { LLAssetType::AT_OBJECT, "OBJECT" },
-        { LLAssetType::AT_NOTECARD, "NOTECARD" },
-        { LLAssetType::AT_CATEGORY, "CATEGORY" },
-        { LLAssetType::AT_LSL_TEXT, "LSL_TEXT" },
-        { LLAssetType::AT_LSL_BYTECODE, "LSL_BYTECODE" },
-        { LLAssetType::AT_TEXTURE_TGA, "TEXTURE_TGA" },
-        { LLAssetType::AT_BODYPART, "BODYPART" },
-        { LLAssetType::AT_SOUND_WAV, "SOUND_WAV" },
-        { LLAssetType::AT_IMAGE_TGA, "IMAGE_TGA" },
-        { LLAssetType::AT_IMAGE_JPEG, "IMAGE_JPEG" },
-        { LLAssetType::AT_ANIMATION, "ANIMATION" },
-        { LLAssetType::AT_GESTURE, "GESTURE" },
-        { LLAssetType::AT_SIMSTATE, "SIMSTATE" },
-        { LLAssetType::AT_LINK, "LINK" },
-        { LLAssetType::AT_LINK_FOLDER, "LINK_FOLDER" },
-        { LLAssetType::AT_MARKETPLACE_FOLDER, "MARKETPLACE_FOLDER" },
-        { LLAssetType::AT_WIDGET, "WIDGET" },
-        { LLAssetType::AT_PERSON, "PERSON" },
-        { LLAssetType::AT_MESH, "MESH" },
-        { LLAssetType::AT_SETTINGS, "SETTINGS" },
-        { LLAssetType::AT_UNKNOWN, "UNKNOWN" }
-    };
-
-    asset_type_to_name_t::iterator iter = asset_type_to_name.find(at);
-    if (iter != asset_type_to_name.end())
-    {
-        return iter->second;
-    }
-
-    return std::string("UNKNOWN");
-}
-
-const std::string LLDiskCache::metaDataToFilepath(const std::string id,
-        LLAssetType::EType at,
-        const std::string extra_info)
-{
-    std::ostringstream file_path;
-
-    file_path << mCacheDir;
-    file_path << gDirUtilp->getDirDelimiter();
-    file_path << mCacheFilenamePrefix;
-    file_path << "_";
-    file_path << id;
-    file_path << "_";
-    file_path << (extra_info.empty() ? "0" : extra_info);
-    //file_path << "_";
-    //file_path << assetTypeToString(at); // see  SL-14210 Prune descriptive tag from new cache filenames
-                                          // for details of why it was removed. Note that if you put it
-                                          // back or change the format of the filename, the cache files
-                                          // files will be invalidated (and perhaps, more importantly,
-                                          // never deleted unless you delete them manually).
-    file_path << ".asset";
-
-    return file_path.str();
-}
-
-void LLDiskCache::updateFileAccessTime(const std::string file_path)
-{
-    /**
-     * Threshold in time_t units that is used to decide if the last access time
-     * time of the file is updated or not. Added as a precaution for the concern
-     * outlined in SL-14582  about frequent writes on older SSDs reducing their
-     * lifespan. I think this is the right place for the threshold value - rather
-     * than it being a pref - do comment on that Jira if you disagree...
-     *
-     * Let's start with 1 hour in time_t units and see how that unfolds
-     */
-    const std::time_t time_threshold = 1 * 60 * 60;
-
-    // current time
-    const std::time_t cur_time = std::time(nullptr);
-
-#if LL_WINDOWS
-    // file last write time
-    const std::time_t last_write_time = boost::filesystem::last_write_time(utf8str_to_utf16str(file_path));
-
-    // delta between cur time and last time the file was written
-    const std::time_t delta_time = cur_time - last_write_time;
-
-    // we only write the new value if the time in time_threshold has elapsed
-    // before the last one
-    if (delta_time > time_threshold)
-    {
-        boost::filesystem::last_write_time(utf8str_to_utf16str(file_path), cur_time);
-    }
-#else
-    // file last write time
-    const std::time_t last_write_time = boost::filesystem::last_write_time(file_path);
-
-    // delta between cur time and last time the file was written
-    const std::time_t delta_time = cur_time - last_write_time;
-
-    // we only write the new value if the time in time_threshold has elapsed
-    // before the last one
-    if (delta_time > time_threshold)
-    {
-        boost::filesystem::last_write_time(file_path, cur_time);
-    }
-#endif
-}
-
-const std::string LLDiskCache::getCacheInfo()
-{
-    std::ostringstream cache_info;
-
-    F32 max_in_mb = (F32)mMaxSizeBytes / (1024.0 * 1024.0);
-    F32 percent_used = ((F32)dirFileSize(mCacheDir) / (F32)mMaxSizeBytes) * 100.0;
-
-    cache_info << std::fixed;
-    cache_info << std::setprecision(1);
-    cache_info << "Max size " << max_in_mb << " MB ";
-    cache_info << "(" << percent_used << "% used)";
-
-    return cache_info.str();
-}
-
-void LLDiskCache::clearCache()
-{
-    /**
-     * See notes on performance in dirFileSize(..) - there may be
-     * a quicker way to do this by operating on the parent dir vs
-     * the component files but it's called infrequently so it's
-     * likely just fine
-     */
-#if LL_WINDOWS
-    std::wstring cache_path(utf8str_to_utf16str(mCacheDir));
-#else
-    std::string cache_path(mCacheDir);
-#endif
-    if (boost::filesystem::is_directory(cache_path))
-    {
-        for (auto& entry : boost::make_iterator_range(boost::filesystem::directory_iterator(cache_path), {}))
-        {
-            if (boost::filesystem::is_regular_file(entry))
-            {
-                if (entry.path().string().find(mCacheFilenamePrefix) != std::string::npos)
-                {
-                    boost::filesystem::remove(entry);
-                }
-            }
-        }
-    }
-}
-
-uintmax_t LLDiskCache::dirFileSize(const std::string dir)
-{
-    uintmax_t total_file_size = 0;
-
-    /**
-     * There may be a better way that works directly on the folder (similar to
-     * right clicking on a folder in the OS and asking for size vs right clicking
-     * on all files and adding up manually) but this is very fast - less than 100ms
-     * for 10,000 files in my testing so, so long as it's not called frequently,
-     * it should be okay. Note that's it's only currently used for logging/debugging
-     * so if performance is ever an issue, optimizing this or removing it altogether,
-     * is an easy win.
-     */
-#if LL_WINDOWS
-    std::wstring dir_path(utf8str_to_utf16str(dir));
-#else
-    std::string dir_path(dir);
-#endif
-    if (boost::filesystem::is_directory(dir_path))
-    {
-        for (auto& entry : boost::make_iterator_range(boost::filesystem::directory_iterator(dir_path), {}))
-        {
-            if (boost::filesystem::is_regular_file(entry))
-            {
-                if (entry.path().string().find(mCacheFilenamePrefix) != std::string::npos)
-                {
-                    total_file_size += boost::filesystem::file_size(entry);
-                }
-            }
-        }
-    }
-
-    return total_file_size;
-}
diff --git a/indra/llfilesystem/lldiskcache.h b/indra/llfilesystem/lldiskcache.h
deleted file mode 100644
index 997884da31..0000000000
--- a/indra/llfilesystem/lldiskcache.h
+++ /dev/null
@@ -1,183 +0,0 @@
-/**
- * @file lldiskcache.h
- * @brief The disk cache implementation declarations.
- *
- * @Description:
- * This code implements a disk cache using the following ideas:
- * 1/ The metadata for a file can be encapsulated in the filename.
-      The filenames will be composed of the following fields:
-        Prefix:     Used to identify the file as a part of the cache.
-                    An additional reason for using a prefix is that it
-                    might be possible, either accidentally or maliciously
-                    to end up with the cache dir set to a non-cache
-                    location such as your OS system dir or a work folder.
-                    Purging files from that would obviously be a disaster
-                    so this is an extra step to help avoid that scenario.
-        ID:         Typically the asset ID (UUID) of the asset being
-                    saved but can be anything valid for a filename
-        Extra Info: A field for use in the future that can be used
-                    to store extra identifiers - e.g. the discard
-                    level of a JPEG2000 file
-        Asset Type: A text string created from the LLAssetType enum
-                    that identifies the type of asset being stored.
-        .asset      A file extension of .asset is used to help
-                    identify this as a Viewer asset file
- * 2/ The time of last access for a file can be updated instantly
- *    for file reads and automatically as part of the file writes.
- * 3/ The purge algorithm collects a list of all files in the
- *    directory, sorts them by date of last access (write) and then
- *    deletes any files based on age until the total size of all
- *    the files is less than the maximum size specified.
- * 4/ An LLSingleton idiom is used since there will only ever be
- *    a single cache and we want to access it from numerous places.
- * 5/ Performance on my modest system seems very acceptable. For
- *    example, in testing, I was able to purge a directory of
- *    10,000 files, deleting about half of them in ~ 1700ms. For
- *    the same sized directory of files, writing the last updated
- *    time to each took less than 600ms indicating that this
- *    important part of the mechanism has almost no overhead.
- *
- * $LicenseInfo:firstyear=2009&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2020, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#ifndef _LLDISKCACHE
-#define _LLDISKCACHE
-
-#include "llsingleton.h"
-
-class LLDiskCache :
-    public LLParamSingleton<LLDiskCache>
-{
-    public:
-        /**
-         * Since this is using the LLSingleton pattern but we
-         * want to allow the constructor to be called first
-         * with various parameters, we also invoke the
-         * LLParamSingleton idiom and use it to initialize
-         * the class via a call in LLAppViewer.
-         */
-        LLSINGLETON(LLDiskCache,
-                    /**
-                     * The full name of the cache folder - typically a
-                     * a child of the main Viewer cache directory. Defined
-                     * by the setting at 'DiskCacheDirName'
-                     */
-                    const std::string cache_dir,
-                    /**
-                     * The maximum size of the cache in bytes - Based on the
-                     * setting at 'CacheSize' and 'DiskCachePercentOfTotal'
-                     */
-                    const int max_size_bytes,
-                    /**
-                     * A flag that enables extra cache debugging so that
-                     * if there are bugs, we can ask uses to enable this
-                     * setting and send us their logs
-                     */
-                    const bool enable_cache_debug_info);
-
-        virtual ~LLDiskCache() = default;
-
-    public:
-        /**
-         * Construct a filename and path to it based on the file meta data
-         * (id, asset type, additional 'extra' info like discard level perhaps)
-         * Worth pointing out that this function used to be in LLFileSystem but
-         * so many things had to be pushed back there to accomodate it, that I
-         * decided to move it here.  Still not sure that's completely right.
-         */
-        const std::string metaDataToFilepath(const std::string id,
-                                             LLAssetType::EType at,
-                                             const std::string extra_info);
-
-        /**
-         * Update the "last write time" of a file to "now". This must be called whenever a
-         * file in the cache is read (not written) so that the last time the file was
-         * accessed is up to date (This is used in the mechanism for purging the cache)
-         */
-        void updateFileAccessTime(const std::string file_path);
-
-        /**
-         * Purge the oldest items in the cache so that the combined size of all files
-         * is no bigger than mMaxSizeBytes.
-         */
-        void purge();
-
-        /**
-         * Clear the cache by removing all the files in the specified cache
-         * directory individually. Only the files that contain a prefix defined
-         * by mCacheFilenamePrefix will be removed.
-         */
-        void clearCache();
-
-        /**
-         * Return some information about the cache for use in About Box etc.
-         */
-        const std::string getCacheInfo();
-
-    private:
-        /**
-         * Utility function to gather the total size the files in a given
-         * directory. Primarily used here to determine the directory size
-         * before and after the cache purge
-         */
-        uintmax_t dirFileSize(const std::string dir);
-
-        /**
-         * Utility function to convert an LLAssetType enum into a
-         * string that we use as part of the cache file filename
-         */
-        const std::string assetTypeToString(LLAssetType::EType at);
-
-    private:
-        /**
-         * The maximum size of the cache in bytes. After purge is called, the
-         * total size of the cache files in the cache directory will be
-         * less than this value
-         */
-        uintmax_t mMaxSizeBytes;
-
-        /**
-         * The folder that holds the cached files. The consumer of this
-         * class must avoid letting the user set this location as a malicious
-         * setting could potentially point it at a non-cache directory (for example,
-         * the Windows System dir) with disastrous results.
-         */
-        std::string mCacheDir;
-
-        /**
-         * The prefix inserted at the start of a cache file filename to
-         * help identify it as a cache file. It's probably not required
-         * (just the presence in the cache folder is enough) but I am
-         * paranoid about the cache folder being set to something bad
-         * like the users' OS system dir by mistake or maliciously and
-         * this will help to offset any damage if that happens.
-         */
-        std::string mCacheFilenamePrefix;
-
-        /**
-         * When enabled, displays additional debugging information in
-         * various parts of the code
-         */
-        bool mEnableCacheDebugInfo;
-};
-
-#endif // _LLDISKCACHE
diff --git a/indra/llfilesystem/llfilesystem.cpp b/indra/llfilesystem/llfilesystem.cpp
deleted file mode 100644
index 64e0b9f193..0000000000
--- a/indra/llfilesystem/llfilesystem.cpp
+++ /dev/null
@@ -1,283 +0,0 @@
-/**
- * @file filesystem.h
- * @brief Simulate local file system operations.
- * @Note The initial implementation does actually use standard C++
- *       file operations but eventually, there will be another
- *       layer that caches and manages file meta data too.
- *
- * $LicenseInfo:firstyear=2002&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#include "linden_common.h"
-
-#include "lldir.h"
-#include "llfilesystem.h"
-#include "llfasttimer.h"
-#include "lldiskcache.h"
-
-const S32 LLFileSystem::READ        = 0x00000001;
-const S32 LLFileSystem::WRITE       = 0x00000002;
-const S32 LLFileSystem::READ_WRITE  = 0x00000003;  // LLFileSystem::READ & LLFileSystem::WRITE
-const S32 LLFileSystem::APPEND      = 0x00000006;  // 0x00000004 & LLFileSystem::WRITE
-
-static LLTrace::BlockTimerStatHandle FTM_VFILE_WAIT("VFile Wait");
-
-LLFileSystem::LLFileSystem(const LLUUID& file_id, const LLAssetType::EType file_type, S32 mode)
-{
-    mFileType = file_type;
-    mFileID = file_id;
-    mPosition = 0;
-    mBytesRead = 0;
-    mMode = mode;
-}
-
-LLFileSystem::~LLFileSystem()
-{
-}
-
-// static
-bool LLFileSystem::getExists(const LLUUID& file_id, const LLAssetType::EType file_type)
-{
-    std::string id_str;
-    file_id.toString(id_str);
-    const std::string extra_info = "";
-    const std::string filename = LLDiskCache::getInstance()->metaDataToFilepath(id_str, file_type, extra_info);
-
-    llifstream file(filename, std::ios::binary);
-    if (file.is_open())
-    {
-        file.seekg(0, std::ios::end);
-        return file.tellg() > 0;
-    }
-    return false;
-}
-
-// static
-bool LLFileSystem::removeFile(const LLUUID& file_id, const LLAssetType::EType file_type)
-{
-    std::string id_str;
-    file_id.toString(id_str);
-    const std::string extra_info = "";
-    const std::string filename =  LLDiskCache::getInstance()->metaDataToFilepath(id_str, file_type, extra_info);
-
-    LLFile::remove(filename.c_str());
-
-    return true;
-}
-
-// static
-bool LLFileSystem::renameFile(const LLUUID& old_file_id, const LLAssetType::EType old_file_type,
-                              const LLUUID& new_file_id, const LLAssetType::EType new_file_type)
-{
-    std::string old_id_str;
-    old_file_id.toString(old_id_str);
-    const std::string extra_info = "";
-    const std::string old_filename =  LLDiskCache::getInstance()->metaDataToFilepath(old_id_str, old_file_type, extra_info);
-
-    std::string new_id_str;
-    new_file_id.toString(new_id_str);
-    const std::string new_filename =  LLDiskCache::getInstance()->metaDataToFilepath(new_id_str, new_file_type, extra_info);
-
-    // Rename needs the new file to not exist.
-    LLFileSystem::removeFile(new_file_id, new_file_type);
-
-    if (LLFile::rename(old_filename, new_filename) != 0)
-    {
-        // We would like to return FALSE here indicating the operation
-        // failed but the original code does not and doing so seems to
-        // break a lot of things so we go with the flow...
-        //return FALSE;
-        LL_WARNS() << "Failed to rename " << old_file_id << " to " << new_id_str << " reason: "  << strerror(errno) << LL_ENDL;
-    }
-
-    return TRUE;
-}
-
-// static
-S32 LLFileSystem::getFileSize(const LLUUID& file_id, const LLAssetType::EType file_type)
-{
-    std::string id_str;
-    file_id.toString(id_str);
-    const std::string extra_info = "";
-    const std::string filename =  LLDiskCache::getInstance()->metaDataToFilepath(id_str, file_type, extra_info);
-
-    S32 file_size = 0;
-    llifstream file(filename, std::ios::binary);
-    if (file.is_open())
-    {
-        file.seekg(0, std::ios::end);
-        file_size = file.tellg();
-    }
-
-    return file_size;
-}
-
-BOOL LLFileSystem::read(U8* buffer, S32 bytes)
-{
-    BOOL success = TRUE;
-
-    std::string id;
-    mFileID.toString(id);
-    const std::string extra_info = "";
-    const std::string filename =  LLDiskCache::getInstance()->metaDataToFilepath(id, mFileType, extra_info);
-
-    llifstream file(filename, std::ios::binary);
-    if (file.is_open())
-    {
-        file.seekg(mPosition, std::ios::beg);
-
-        file.read((char*)buffer, bytes);
-
-        if (file)
-        {
-            mBytesRead = bytes;
-        }
-        else
-        {
-            mBytesRead = file.gcount();
-        }
-
-        file.close();
-
-        mPosition += mBytesRead;
-        if (!mBytesRead)
-        {
-            success = FALSE;
-        }
-    }
-
-    // update the last access time for the file - this is required
-    // even though we are reading and not writing because this is the
-    // way the cache works - it relies on a valid "last accessed time" for
-    // each file so it knows how to remove the oldest, unused files
-    LLDiskCache::getInstance()->updateFileAccessTime(filename);
-
-    return success;
-}
-
-S32 LLFileSystem::getLastBytesRead()
-{
-    return mBytesRead;
-}
-
-BOOL LLFileSystem::eof()
-{
-    return mPosition >= getSize();
-}
-
-BOOL LLFileSystem::write(const U8* buffer, S32 bytes)
-{
-    std::string id_str;
-    mFileID.toString(id_str);
-    const std::string extra_info = "";
-    const std::string filename =  LLDiskCache::getInstance()->metaDataToFilepath(id_str, mFileType, extra_info);
-
-    BOOL success = FALSE;
-
-    if (mMode == APPEND)
-    {
-        llofstream ofs(filename, std::ios::app | std::ios::binary);
-        if (ofs)
-        {
-            ofs.write((const char*)buffer, bytes);
-
-            success = TRUE;
-        }
-    }
-    else
-    {
-        llofstream ofs(filename, std::ios::binary);
-        if (ofs)
-        {
-            ofs.write((const char*)buffer, bytes);
-
-            mPosition += bytes;
-
-            success = TRUE;
-        }
-    }
-
-    return success;
-}
-
-BOOL LLFileSystem::seek(S32 offset, S32 origin)
-{
-    if (-1 == origin)
-    {
-        origin = mPosition;
-    }
-
-    S32 new_pos = origin + offset;
-
-    S32 size = getSize();
-
-    if (new_pos > size)
-    {
-        LL_WARNS() << "Attempt to seek past end of file" << LL_ENDL;
-
-        mPosition = size;
-        return FALSE;
-    }
-    else if (new_pos < 0)
-    {
-        LL_WARNS() << "Attempt to seek past beginning of file" << LL_ENDL;
-
-        mPosition = 0;
-        return FALSE;
-    }
-
-    mPosition = new_pos;
-    return TRUE;
-}
-
-S32 LLFileSystem::tell() const
-{
-    return mPosition;
-}
-
-S32 LLFileSystem::getSize()
-{
-    return LLFileSystem::getFileSize(mFileID, mFileType);
-}
-
-S32 LLFileSystem::getMaxSize()
-{
-    // offer up a huge size since we don't care what the max is
-    return INT_MAX;
-}
-
-BOOL LLFileSystem::rename(const LLUUID& new_id, const LLAssetType::EType new_type)
-{
-    LLFileSystem::renameFile(mFileID, mFileType, new_id, new_type);
-
-    mFileID = new_id;
-    mFileType = new_type;
-
-    return TRUE;
-}
-
-BOOL LLFileSystem::remove()
-{
-    LLFileSystem::removeFile(mFileID, mFileType);
-
-    return TRUE;
-}
diff --git a/indra/llfilesystem/llfilesystem.h b/indra/llfilesystem/llfilesystem.h
deleted file mode 100644
index 89bfff5798..0000000000
--- a/indra/llfilesystem/llfilesystem.h
+++ /dev/null
@@ -1,78 +0,0 @@
-/**
- * @file filesystem.h
- * @brief Simulate local file system operations.
- * @Note The initial implementation does actually use standard C++
- *       file operations but eventually, there will be another
- *       layer that caches and manages file meta data too.
- *
- * $LicenseInfo:firstyear=2002&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#ifndef LL_FILESYSTEM_H
-#define LL_FILESYSTEM_H
-
-#include "lluuid.h"
-#include "llassettype.h"
-#include "lldiskcache.h"
-
-class LLFileSystem
-{
-    public:
-        LLFileSystem(const LLUUID& file_id, const LLAssetType::EType file_type, S32 mode = LLFileSystem::READ);
-        ~LLFileSystem();
-
-        BOOL read(U8* buffer, S32 bytes);
-        S32  getLastBytesRead();
-        BOOL eof();
-
-        BOOL write(const U8* buffer, S32 bytes);
-        BOOL seek(S32 offset, S32 origin = -1);
-        S32  tell() const;
-
-        S32 getSize();
-        S32 getMaxSize();
-        BOOL rename(const LLUUID& new_id, const LLAssetType::EType new_type);
-        BOOL remove();
-
-        static bool getExists(const LLUUID& file_id, const LLAssetType::EType file_type);
-        static bool removeFile(const LLUUID& file_id, const LLAssetType::EType file_type);
-        static bool renameFile(const LLUUID& old_file_id, const LLAssetType::EType old_file_type,
-                               const LLUUID& new_file_id, const LLAssetType::EType new_file_type);
-        static S32 getFileSize(const LLUUID& file_id, const LLAssetType::EType file_type);
-
-    public:
-        static const S32 READ;
-        static const S32 WRITE;
-        static const S32 READ_WRITE;
-        static const S32 APPEND;
-
-    protected:
-        LLAssetType::EType mFileType;
-        LLUUID  mFileID;
-        S32     mPosition;
-        S32     mMode;
-        S32     mBytesRead;
-//private:
-//    static const std::string idToFilepath(const std::string id, LLAssetType::EType at);
-};
-
-#endif  // LL_FILESYSTEM_H
diff --git a/indra/llimage/CMakeLists.txt b/indra/llimage/CMakeLists.txt
index dc8e9f7c2f..293ada7548 100644
--- a/indra/llimage/CMakeLists.txt
+++ b/indra/llimage/CMakeLists.txt
@@ -6,7 +6,7 @@ include(00-Common)
 include(LLCommon)
 include(LLImage)
 include(LLMath)
-include(LLFileSystem)
+include(LLVFS)
 include(LLKDU)
 include(LLImageJ2COJ)
 include(ZLIB)
@@ -17,7 +17,7 @@ include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLCOMMON_SYSTEM_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${PNG_INCLUDE_DIRS}
     ${ZLIB_INCLUDE_DIRS}
     )
@@ -68,7 +68,7 @@ else (USE_KDU)
 endif (USE_KDU)
 
 target_link_libraries(llimage
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
     ${JPEG_LIBRARIES}
diff --git a/indra/llimage/llimage.cpp b/indra/llimage/llimage.cpp
index 350a8eb120..aed8943439 100644
--- a/indra/llimage/llimage.cpp
+++ b/indra/llimage/llimage.cpp
@@ -2219,11 +2219,20 @@ bool LLImageFormatted::save(const std::string &filename)
 	return true;
 }
 
+// bool LLImageFormatted::save(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type)
+// Depricated to remove VFS dependency.
+// Use:
+// LLVFile::writeFile(image->getData(), image->getDataSize(), vfs, uuid, type);
+
+//----------------------------------------------------------------------------
+
 S8 LLImageFormatted::getCodec() const
 {
 	return mCodec;
 }
 
+//============================================================================
+
 static void avg4_colors4(const U8* a, const U8* b, const U8* c, const U8* d, U8* dst)
 {
 	dst[0] = (U8)(((U32)(a[0]) + b[0] + c[0] + d[0])>>2);
diff --git a/indra/llinventory/CMakeLists.txt b/indra/llinventory/CMakeLists.txt
index 04975940aa..e829788c91 100644
--- a/indra/llinventory/CMakeLists.txt
+++ b/indra/llinventory/CMakeLists.txt
@@ -7,7 +7,7 @@ include(LLCommon)
 include(LLCoreHttp)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 
 include_directories(
@@ -81,7 +81,7 @@ if (LL_TESTS)
     LL_ADD_PROJECT_UNIT_TESTS(llinventory "${llinventory_TEST_SOURCE_FILES}")
 
     #set(TEST_DEBUG on)
-    set(test_libs llinventory ${LLMESSAGE_LIBRARIES} ${LLFILESYSTEM_LIBRARIES} ${LLCOREHTTP_LIBRARIES} ${LLMATH_LIBRARIES} ${LLCOMMON_LIBRARIES} ${WINDOWS_LIBRARIES})
+    set(test_libs llinventory ${LLMESSAGE_LIBRARIES} ${LLVFS_LIBRARIES} ${LLCOREHTTP_LIBRARIES} ${LLMATH_LIBRARIES} ${LLCOMMON_LIBRARIES} ${WINDOWS_LIBRARIES})
     LL_ADD_INTEGRATION_TEST(inventorymisc "" "${test_libs}")
     LL_ADD_INTEGRATION_TEST(llparcel "" "${test_libs}")
 endif (LL_TESTS)
diff --git a/indra/llmessage/CMakeLists.txt b/indra/llmessage/CMakeLists.txt
index f0a1dfe940..2f99ca069e 100644
--- a/indra/llmessage/CMakeLists.txt
+++ b/indra/llmessage/CMakeLists.txt
@@ -9,7 +9,7 @@ include(LLCommon)
 include(LLCoreHttp)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLAddBuildTest)
 include(Python)
 include(Tut)
@@ -23,7 +23,7 @@ include_directories(
     ${LLCOREHTTP_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLMESSAGE_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${JSONCPP_INCLUDE_DIR}
     )
 
@@ -209,7 +209,7 @@ target_link_libraries(
   llmessage
   ${CURL_LIBRARIES}
   ${LLCOMMON_LIBRARIES}
-  ${LLFILESYSTEM_LIBRARIES}
+  ${LLVFS_LIBRARIES}
   ${LLMATH_LIBRARIES}
   ${JSONCPP_LIBRARIES}
   ${OPENSSL_LIBRARIES}
@@ -227,7 +227,7 @@ target_link_libraries(
   llmessage
   ${CURL_LIBRARIES}
   ${LLCOMMON_LIBRARIES}
-  ${LLFILESYSTEM_LIBRARIES}
+  ${LLVFS_LIBRARIES}
   ${LLMATH_LIBRARIES}
   ${JSONCPP_LIBRARIES}
   ${OPENSSL_LIBRARIES}
@@ -257,7 +257,7 @@ if (LL_TESTS)
 if (LINUX)
   set(test_libs
     ${WINDOWS_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${CURL_LIBRARIES}
     ${NGHTTP2_LIBRARIES}
@@ -273,7 +273,7 @@ if (LINUX)
 else (LINUX)
   set(test_libs
     ${WINDOWS_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${CURL_LIBRARIES}
     ${NGHTTP2_LIBRARIES}
diff --git a/indra/llmessage/llassetstorage.cpp b/indra/llmessage/llassetstorage.cpp
index f38a5e663e..d7801b6ddc 100644
--- a/indra/llmessage/llassetstorage.cpp
+++ b/indra/llmessage/llassetstorage.cpp
@@ -42,7 +42,8 @@
 // this library includes
 #include "message.h"
 #include "llxfermanager.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "lldbstrings.h"
 
 #include "lltransfersourceasset.h"
@@ -201,7 +202,7 @@ LLBaseDownloadRequest::LLBaseDownloadRequest(const LLUUID &uuid, const LLAssetTy
       mIsTemp(FALSE),
       mIsPriority(FALSE),
       mDataSentInFirstPacket(FALSE),
-      mDataIsInCache(FALSE)
+      mDataIsInVFS(FALSE)
 {
     // Need to guarantee that this time is up to date, we may be creating a circuit even though we haven't been
     //  running a message system loop.
@@ -265,8 +266,7 @@ LLSD LLAssetRequest::getFullDetails() const
     sd["is_local"] = mIsLocal;
     sd["is_priority"] = mIsPriority;
     sd["data_send_in_first_packet"] = mDataSentInFirstPacket;
-    // Note: cannot change this (easily) since it is consumed by server
-    sd["data_is_in_vfs"] = mDataIsInCache;
+    sd["data_is_in_vfs"] = mDataIsInVFS;
 
     return sd;
 }
@@ -330,23 +330,28 @@ LLBaseDownloadRequest* LLEstateAssetRequest::getCopy()
 // TODO: rework tempfile handling?
 
 
-LLAssetStorage::LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer, const LLHost &upstream_host)
+LLAssetStorage::LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer, LLVFS *vfs, LLVFS *static_vfs, const LLHost &upstream_host)
 {
-    _init(msg, xfer, upstream_host);
+    _init(msg, xfer, vfs, static_vfs, upstream_host);
 }
 
-LLAssetStorage::LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer)
+LLAssetStorage::LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+                               LLVFS *vfs, LLVFS *static_vfs)
 {
-    _init(msg, xfer, LLHost());
+    _init(msg, xfer, vfs, static_vfs, LLHost());
 }
 
 void LLAssetStorage::_init(LLMessageSystem *msg,
                            LLXferManager *xfer,
+                           LLVFS *vfs,
+                           LLVFS *static_vfs,
                            const LLHost &upstream_host)
 {
     mShutDown = FALSE;
     mMessageSys = msg;
     mXferManager = xfer;
+    mVFS = vfs;
+    mStaticVFS = static_vfs;
 
     setUpstream(upstream_host);
     msg->setHandlerFuncFast(_PREHASH_AssetUploadComplete, processUploadComplete, (void **)this);
@@ -425,7 +430,7 @@ void LLAssetStorage::_cleanupRequests(BOOL all, S32 error)
         }
         if (tmp->mDownCallback)
         {
-            tmp->mDownCallback(tmp->getUUID(), tmp->getType(), tmp->mUserData, error, LLExtStat::NONE);
+            tmp->mDownCallback(mVFS, tmp->getUUID(), tmp->getType(), tmp->mUserData, error, LLExtStat::NONE);
         }
         if (tmp->mInfoCallback)
         {
@@ -438,10 +443,10 @@ void LLAssetStorage::_cleanupRequests(BOOL all, S32 error)
 
 BOOL LLAssetStorage::hasLocalAsset(const LLUUID &uuid, const LLAssetType::EType type)
 {
-    return LLFileSystem::getExists(uuid, type);
+    return mStaticVFS->getExists(uuid, type) || mVFS->getExists(uuid, type);
 }
 
-bool LLAssetStorage::findInCacheAndInvokeCallback(const LLUUID& uuid, LLAssetType::EType type,
+bool LLAssetStorage::findInStaticVFSAndInvokeCallback(const LLUUID& uuid, LLAssetType::EType type,
                                                       LLGetAssetCallback callback, void *user_data)
 {
     if (user_data)
@@ -450,17 +455,17 @@ bool LLAssetStorage::findInCacheAndInvokeCallback(const LLUUID& uuid, LLAssetTyp
         llassert(callback != NULL);
     }
 
-    BOOL exists = LLFileSystem::getExists(uuid, type);
+    BOOL exists = mStaticVFS->getExists(uuid, type);
     if (exists)
     {
-        LLFileSystem file(uuid, type);
+        LLVFile file(mStaticVFS, uuid, type);
         U32 size = file.getSize();
         if (size > 0)
         {
             // we've already got the file
             if (callback)
             {
-                callback(uuid, type, user_data, LL_ERR_NOERR, LLExtStat::CACHE_CACHED);
+                callback(mStaticVFS, uuid, type, user_data, LL_ERR_NOERR, LLExtStat::VFS_CACHED);
             }
             return true;
         }
@@ -501,7 +506,7 @@ void LLAssetStorage::getAssetData(const LLUUID uuid,
         if (callback)
         {
             add(sFailedDownloadCount, 1);
-            callback(uuid, type, user_data, LL_ERR_ASSET_REQUEST_FAILED, LLExtStat::NONE);
+            callback(mVFS, uuid, type, user_data, LL_ERR_ASSET_REQUEST_FAILED, LLExtStat::NONE);
         }
         return;
     }
@@ -512,19 +517,20 @@ void LLAssetStorage::getAssetData(const LLUUID uuid,
         if (callback)
         {
             add(sFailedDownloadCount, 1);
-            callback(uuid, type, user_data, LL_ERR_ASSET_REQUEST_NOT_IN_DATABASE, LLExtStat::NULL_UUID);
+            callback(mVFS, uuid, type, user_data, LL_ERR_ASSET_REQUEST_NOT_IN_DATABASE, LLExtStat::NULL_UUID);
         }
         return;
     }
 
-    if (findInCacheAndInvokeCallback(uuid,type,callback,user_data))
+    // Try static VFS first.
+    if (findInStaticVFSAndInvokeCallback(uuid,type,callback,user_data))
     {
-        LL_DEBUGS("AssetStorage") << "ASSET_TRACE asset " << uuid << " found in cache" << LL_ENDL;
+        LL_DEBUGS("AssetStorage") << "ASSET_TRACE asset " << uuid << " found in static VFS" << LL_ENDL;
         return;
     }
 
-    BOOL exists = LLFileSystem::getExists(uuid, type);
-    LLFileSystem file(uuid, type);
+    BOOL exists = mVFS->getExists(uuid, type);
+    LLVFile file(mVFS, uuid, type);
     U32 size = exists ? file.getSize() : 0;
 
     if (size > 0)
@@ -534,10 +540,10 @@ void LLAssetStorage::getAssetData(const LLUUID uuid,
         // unless there's a weird error
         if (callback)
         {
-            callback(uuid, type, user_data, LL_ERR_NOERR, LLExtStat::CACHE_CACHED);
+            callback(mVFS, uuid, type, user_data, LL_ERR_NOERR, LLExtStat::VFS_CACHED);
         }
 
-        LL_DEBUGS("AssetStorage") << "ASSET_TRACE asset " << uuid << " found in cache" << LL_ENDL;
+        LL_DEBUGS("AssetStorage") << "ASSET_TRACE asset " << uuid << " found in VFS" << LL_ENDL;
     }
     else
     {
@@ -610,7 +616,7 @@ void LLAssetStorage::removeAndCallbackPendingDownloads(const LLUUID& file_id, LL
             {
                 add(sFailedDownloadCount, 1);
             }
-            tmp->mDownCallback(callback_id, callback_type, tmp->mUserData, result_code, ext_status);
+            tmp->mDownCallback(gAssetStorage->mVFS, callback_id, callback_type, tmp->mUserData, result_code, ext_status);
         }
         delete tmp;
     }
@@ -664,7 +670,7 @@ void LLAssetStorage::downloadCompleteCallback(
     if (LL_ERR_NOERR == result)
     {
         // we might have gotten a zero-size file
-        LLFileSystem vfile(callback_id, callback_type);
+        LLVFile vfile(gAssetStorage->mVFS, callback_id, callback_type);
         if (vfile.getSize() <= 0)
         {
             LL_WARNS("AssetStorage") << "downloadCompleteCallback has non-existent or zero-size asset " << callback_id << LL_ENDL;
@@ -713,19 +719,19 @@ void LLAssetStorage::getEstateAsset(
         if (callback)
         {
             add(sFailedDownloadCount, 1);
-            callback(asset_id, atype, user_data, LL_ERR_ASSET_REQUEST_NOT_IN_DATABASE, LLExtStat::NULL_UUID);
+            callback(mVFS, asset_id, atype, user_data, LL_ERR_ASSET_REQUEST_NOT_IN_DATABASE, LLExtStat::NULL_UUID);
         }
         return;
     }
 
-    // Try static first.
-    if (findInCacheAndInvokeCallback(asset_id,atype,callback,user_data))
+    // Try static VFS first.
+    if (findInStaticVFSAndInvokeCallback(asset_id,atype,callback,user_data))
     {
         return;
     }
     
-    BOOL exists = LLFileSystem::getExists(asset_id, atype);
-    LLFileSystem file(asset_id, atype);
+    BOOL exists = mVFS->getExists(asset_id, atype);
+    LLVFile file(mVFS, asset_id, atype);
     U32 size = exists ? file.getSize() : 0;
 
     if (size > 0)
@@ -735,7 +741,7 @@ void LLAssetStorage::getEstateAsset(
         // unless there's a weird error
         if (callback)
         {
-            callback(asset_id, atype, user_data, LL_ERR_NOERR, LLExtStat::CACHE_CACHED);
+            callback(mVFS, asset_id, atype, user_data, LL_ERR_NOERR, LLExtStat::VFS_CACHED);
         }
     }
     else
@@ -786,7 +792,7 @@ void LLAssetStorage::getEstateAsset(
             if (callback)
             {
                 add(sFailedDownloadCount, 1);
-                callback(asset_id, atype, user_data, LL_ERR_CIRCUIT_GONE, LLExtStat::NO_UPSTREAM);
+                callback(mVFS, asset_id, atype, user_data, LL_ERR_CIRCUIT_GONE, LLExtStat::NO_UPSTREAM);
             }
         }
     }
@@ -818,7 +824,7 @@ void LLAssetStorage::downloadEstateAssetCompleteCallback(
     if (LL_ERR_NOERR == result)
     {
         // we might have gotten a zero-size file
-        LLFileSystem vfile(req->getUUID(), req->getAType());
+        LLVFile vfile(gAssetStorage->mVFS, req->getUUID(), req->getAType());
         if (vfile.getSize() <= 0)
         {
             LL_WARNS("AssetStorage") << "downloadCompleteCallback has non-existent or zero-size asset!" << LL_ENDL;
@@ -832,7 +838,7 @@ void LLAssetStorage::downloadEstateAssetCompleteCallback(
     {
         add(sFailedDownloadCount, 1);
     }
-    req->mDownCallback(req->getUUID(), req->getAType(), req->mUserData, result, ext_status);
+    req->mDownCallback(gAssetStorage->mVFS, req->getUUID(), req->getAType(), req->mUserData, result, ext_status);
 }
 
 void LLAssetStorage::getInvItemAsset(
@@ -855,13 +861,14 @@ void LLAssetStorage::getInvItemAsset(
 
     if(asset_id.notNull())
     {
-        if (findInCacheAndInvokeCallback( asset_id, atype, callback, user_data))
+        // Try static VFS first.
+        if (findInStaticVFSAndInvokeCallback( asset_id, atype, callback, user_data))
         {
             return;
         }
 
-        exists = LLFileSystem::getExists(asset_id, atype);
-        LLFileSystem file(asset_id, atype);
+        exists = mVFS->getExists(asset_id, atype);
+        LLVFile file(mVFS, asset_id, atype);
         size = exists ? file.getSize() : 0;
         if(exists && size < 1)
         {
@@ -878,7 +885,7 @@ void LLAssetStorage::getInvItemAsset(
         // unless there's a weird error
         if (callback)
         {
-            callback(asset_id, atype, user_data, LL_ERR_NOERR, LLExtStat::CACHE_CACHED);
+            callback(mVFS, asset_id, atype, user_data, LL_ERR_NOERR, LLExtStat::VFS_CACHED);
         }
     }
     else
@@ -929,7 +936,7 @@ void LLAssetStorage::getInvItemAsset(
             if (callback)
             {
                 add(sFailedDownloadCount, 1);
-                callback(asset_id, atype, user_data, LL_ERR_CIRCUIT_GONE, LLExtStat::NO_UPSTREAM);
+                callback(mVFS, asset_id, atype, user_data, LL_ERR_CIRCUIT_GONE, LLExtStat::NO_UPSTREAM);
             }
         }
     }
@@ -961,7 +968,7 @@ void LLAssetStorage::downloadInvItemCompleteCallback(
     if (LL_ERR_NOERR == result)
     {
         // we might have gotten a zero-size file
-        LLFileSystem vfile(req->getUUID(), req->getType());
+        LLVFile vfile(gAssetStorage->mVFS, req->getUUID(), req->getType());
         if (vfile.getSize() <= 0)
         {
             LL_WARNS("AssetStorage") << "downloadCompleteCallback has non-existent or zero-size asset!" << LL_ENDL;
@@ -975,7 +982,7 @@ void LLAssetStorage::downloadInvItemCompleteCallback(
     {
         add(sFailedDownloadCount, 1);
     }
-    req->mDownCallback(req->getUUID(), req->getType(), req->mUserData, result, ext_status);
+    req->mDownCallback(gAssetStorage->mVFS, req->getUUID(), req->getType(), req->mUserData, result, ext_status);
 }
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -1286,7 +1293,7 @@ bool LLAssetStorage::deletePendingRequestImpl(LLAssetStorage::request_list_t* re
         if (req->mDownCallback)
         {
             add(sFailedDownloadCount, 1);
-            req->mDownCallback(req->getUUID(), req->getType(), req->mUserData, error, LLExtStat::REQUEST_DROPPED);
+            req->mDownCallback(mVFS, req->getUUID(), req->getType(), req->mUserData, error, LLExtStat::REQUEST_DROPPED);
         }
         if (req->mInfoCallback)
         {
@@ -1356,7 +1363,8 @@ void LLAssetStorage::getAssetData(const LLUUID uuid,
     {
         LLAssetRequest* tmp = *iter++;
 
-        auto cbptr = tmp->mDownCallback.target<void(*)(const LLUUID &, LLAssetType::EType, void *, S32, LLExtStat)>();
+        //void(*const* cbptr)(LLVFS *, const LLUUID &, LLAssetType::EType, void *, S32, LLExtStat) 
+        auto cbptr = tmp->mDownCallback.target<void(*)(LLVFS *, const LLUUID &, LLAssetType::EType, void *, S32, LLExtStat)>();
 
         if (type == tmp->getType() && 
             uuid == tmp->getUUID() &&
@@ -1381,7 +1389,8 @@ void LLAssetStorage::getAssetData(const LLUUID uuid,
 }
 
 // static
-void LLAssetStorage::legacyGetDataCallback(const LLUUID &uuid, 
+void LLAssetStorage::legacyGetDataCallback(LLVFS *vfs,
+                                           const LLUUID &uuid, 
                                            LLAssetType::EType type,
                                            void *user_data, 
                                            S32 status, 
@@ -1396,7 +1405,7 @@ void LLAssetStorage::legacyGetDataCallback(const LLUUID &uuid,
     if ( !status
          && !toxic )
     {
-        LLFileSystem file(uuid, type);
+        LLVFile file(vfs, uuid, type);
 
         std::string uuid_str;
 
diff --git a/indra/llmessage/llassetstorage.h b/indra/llmessage/llassetstorage.h
index e0f22f1160..c799d8eefc 100644
--- a/indra/llmessage/llassetstorage.h
+++ b/indra/llmessage/llassetstorage.h
@@ -44,6 +44,7 @@
 class LLMessageSystem;
 class LLXferManager;
 class LLAssetStorage;
+class LLVFS;
 class LLSD;
 
 // anything that takes longer than this to download will abort.
@@ -59,11 +60,11 @@ const int LL_ERR_ASSET_REQUEST_NOT_IN_DATABASE = -4;
 const int LL_ERR_INSUFFICIENT_PERMISSIONS = -5;
 const int LL_ERR_PRICE_MISMATCH = -23018;
 
-// *TODO: these typedefs are passed into the cache via a legacy C function pointer
+// *TODO: these typedefs are passed into the VFS via a legacy C function pointer
 // future project would be to convert these to C++ callables (std::function<>) so that 
 // we can use bind and remove the userData parameter.
 // 
-typedef std::function<void(const LLUUID &asset_id, LLAssetType::EType asset_type, void *user_data, S32 status, LLExtStat ext_status)> LLGetAssetCallback;
+typedef std::function<void(LLVFS *vfs, const LLUUID &asset_id, LLAssetType::EType asset_type, void *user_data, S32 status, LLExtStat ext_status)> LLGetAssetCallback;
 typedef std::function<void(const LLUUID &asset_id, void *user_data, S32 status, LLExtStat ext_status)> LLStoreAssetCallback;
 
 
@@ -119,6 +120,7 @@ protected:
 
 public:
     LLGetAssetCallback mDownCallback;
+//    void(*mDownCallback)(LLVFS*, const LLUUID&, LLAssetType::EType, void *, S32, LLExtStat);
 
     void	*mUserData;
     LLHost  mHost;
@@ -126,7 +128,7 @@ public:
     F64Seconds		mTime;				// Message system time
     BOOL    mIsPriority;
     BOOL	mDataSentInFirstPacket;
-    BOOL	mDataIsInCache;
+    BOOL	mDataIsInVFS;
 };
 
 class LLAssetRequest : public LLBaseDownloadRequest
@@ -196,6 +198,9 @@ typedef std::map<LLUUID,U64,lluuid_less> toxic_asset_map_t;
 class LLAssetStorage
 {
 public:
+	// VFS member is public because static child methods need it :(
+	LLVFS *mVFS;
+	LLVFS *mStaticVFS;
     typedef ::LLStoreAssetCallback LLStoreAssetCallback;
     typedef ::LLGetAssetCallback LLGetAssetCallback;
 
@@ -225,9 +230,11 @@ protected:
 	toxic_asset_map_t	mToxicAssetMap;		// Objects in this list are known to cause problems and are not loaded
 
 public:
-	LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer, const LLHost &upstream_host);
+	LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+				   LLVFS *vfs, LLVFS *static_vfs, const LLHost &upstream_host);
 
-	LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer);
+	LLAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+				   LLVFS *vfs, LLVFS *static_vfs);
 	virtual ~LLAssetStorage();
 
 	void setUpstream(const LLHost &upstream_host);
@@ -277,7 +284,7 @@ public:
 	void		markAssetToxic( const LLUUID& uuid );
 
 protected:
-	bool findInCacheAndInvokeCallback(const LLUUID& uuid, LLAssetType::EType type,
+	bool findInStaticVFSAndInvokeCallback(const LLUUID& uuid, LLAssetType::EType type,
 										  LLGetAssetCallback callback, void *user_data);
 
 	LLSD getPendingDetailsImpl(const request_list_t* requests,
@@ -368,7 +375,7 @@ public:
 		bool user_waiting = false,
 		F64Seconds timeout  = LL_ASSET_STORAGE_TIMEOUT) = 0;
 
-	static void legacyGetDataCallback(const LLUUID &uuid, LLAssetType::EType, void *user_data, S32 status, LLExtStat ext_status);
+	static void legacyGetDataCallback(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType, void *user_data, S32 status, LLExtStat ext_status);
 	static void legacyStoreDataCallback(const LLUUID &uuid, void *user_data, S32 status, LLExtStat ext_status);
 
 	// add extra methods to handle metadata
@@ -378,12 +385,15 @@ protected:
 	void _callUploadCallbacks(const LLUUID &uuid, const LLAssetType::EType asset_type, BOOL success, LLExtStat ext_status);
 
 	virtual void _queueDataRequest(const LLUUID& uuid, LLAssetType::EType type, LLGetAssetCallback callback,
+//								   void (*callback)(LLVFS *vfs, const LLUUID&, LLAssetType::EType, void *, S32, LLExtStat),
 								   void *user_data, BOOL duplicate,
 								   BOOL is_priority) = 0;
 
 private:
 	void _init(LLMessageSystem *msg,
 			   LLXferManager *xfer,
+			   LLVFS *vfs,
+			   LLVFS *static_vfs,
 			   const LLHost &upstream_host);
 
 protected:
@@ -398,7 +408,7 @@ protected:
 		MR_FILE_NONEXIST	= 3,	// Old format store call - source file does not exist
 		MR_NO_FILENAME		= 4,	// Old format store call - source filename is NULL/0-length
 		MR_NO_UPSTREAM		= 5,	// Upstream provider is missing
-		MR_CACHE_CORRUPTION	= 6		// cache is corrupt - too-large or mismatched stated/returned sizes
+		MR_VFS_CORRUPTION	= 6		// VFS is corrupt - too-large or mismatched stated/returned sizes
 	};
 
 	static class LLMetrics *metric_recipient;
diff --git a/indra/llmessage/llcorehttputil.cpp b/indra/llmessage/llcorehttputil.cpp
index 7031f1aa8c..0eae6d9826 100644
--- a/indra/llmessage/llcorehttputil.cpp
+++ b/indra/llmessage/llcorehttputil.cpp
@@ -37,7 +37,7 @@
 #include "llsdserialize.h"
 #include "reader.h" // JSON
 #include "writer.h" // JSON
-#include "llfilesystem.h"
+#include "llvfile.h"
 
 #include "message.h" // for getting the port
 
@@ -784,7 +784,7 @@ LLSD HttpCoroutineAdapter::postFileAndSuspend(LLCore::HttpRequest::ptr_t request
     // scoping for our streams so that they go away when we no longer need them.
     {
         LLCore::BufferArrayStream outs(fileData.get());
-        LLFileSystem vfile(assetId, assetType, LLFileSystem::READ);
+        LLVFile vfile(gVFS, assetId, assetType, LLVFile::READ);
 
         S32 fileSize = vfile.getSize();
         U8* fileBuffer;
diff --git a/indra/llmessage/llextendedstatus.h b/indra/llmessage/llextendedstatus.h
index 2a53dced80..9923d73c1a 100644
--- a/indra/llmessage/llextendedstatus.h
+++ b/indra/llmessage/llextendedstatus.h
@@ -1,7 +1,7 @@
 /** 
  * @file llextendedstatus.h
  * @date   August 2007
- * @brief extended status codes for curl/resident asset storage and delivery
+ * @brief extended status codes for curl/vfs/resident asset storage and delivery
  *
  * $LicenseInfo:firstyear=2007&license=viewerlgpl$
  * Second Life Viewer Source Code
@@ -32,9 +32,9 @@ enum class LLExtStat: uint32_t
 {
 	// Status provider groups - Top bits indicate which status type it is
 	// Zero is common status code (next section)
-	CURL_RESULT	 = 1UL<<30, // serviced by curl - use 1L if we really implement the below
-	RES_RESULT	 = 2UL<<30, // serviced by resident copy
-	CACHE_RESULT = 3UL<<30, // serviced by cache
+	CURL_RESULT	= 1UL<<30, // serviced by curl - use 1L if we really implement the below
+	RES_RESULT	= 2UL<<30, // serviced by resident copy
+	VFS_RESULT	= 3UL<<30, // serviced by vfs
 
 
 	// Common Status Codes
@@ -54,9 +54,9 @@ enum class LLExtStat: uint32_t
 	// Memory-Resident status codes:
 	// None at present
 
-	// CACHE status codes:
-	CACHE_CACHED	= CACHE_RESULT | 0x0001,
-	CACHE_CORRUPT	= CACHE_RESULT | 0x0002,
+	// VFS status codes:
+	VFS_CACHED	= VFS_RESULT | 0x0001,
+	VFS_CORRUPT	= VFS_RESULT | 0x0002,
 };
 
 
diff --git a/indra/llmessage/lltransfersourceasset.cpp b/indra/llmessage/lltransfersourceasset.cpp
index 027283232d..80ed3340c6 100644
--- a/indra/llmessage/lltransfersourceasset.cpp
+++ b/indra/llmessage/lltransfersourceasset.cpp
@@ -32,7 +32,7 @@
 #include "message.h"
 #include "lldatapacker.h"
 #include "lldir.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 
 LLTransferSourceAsset::LLTransferSourceAsset(const LLUUID &request_id, const F32 priority) :
 	LLTransferSource(LLTST_ASSET, request_id, priority),
@@ -99,7 +99,7 @@ LLTSCode LLTransferSourceAsset::dataCallback(const S32 packet_id,
 		return LLTS_SKIP;
 	}
 
-	LLFileSystem vf(mParams.getAssetID(), mParams.getAssetType(), LLFileSystem::READ);
+	LLVFile vf(gAssetStorage->mVFS, mParams.getAssetID(), mParams.getAssetType(), LLVFile::READ);
 
 	if (!vf.getSize())
 	{
@@ -171,7 +171,7 @@ BOOL LLTransferSourceAsset::unpackParams(LLDataPacker &dp)
 }
 
 
-void LLTransferSourceAsset::responderCallback(const LLUUID& uuid, LLAssetType::EType type,
+void LLTransferSourceAsset::responderCallback(LLVFS *vfs, const LLUUID& uuid, LLAssetType::EType type,
 											  void *user_data, S32 result, LLExtStat ext_status )
 {
 	LLUUID *tidp = ((LLUUID*) user_data);
@@ -198,7 +198,7 @@ void LLTransferSourceAsset::responderCallback(const LLUUID& uuid, LLAssetType::E
 	if (LL_ERR_NOERR == result)
 	{
 		// Everything's OK.
-		LLFileSystem vf(uuid, type, LLFileSystem::READ);
+		LLVFile vf(gAssetStorage->mVFS, uuid, type, LLVFile::READ);
 		tsap->mSize = vf.getSize();
 		status = LLTS_OK;
 	}
diff --git a/indra/llmessage/lltransfersourceasset.h b/indra/llmessage/lltransfersourceasset.h
index 585e683cb3..3abda83cf8 100644
--- a/indra/llmessage/lltransfersourceasset.h
+++ b/indra/llmessage/lltransfersourceasset.h
@@ -30,7 +30,7 @@
 #include "lltransfermanager.h"
 #include "llassetstorage.h"
 
-class LLFileSystem;
+class LLVFile;
 
 class LLTransferSourceParamsAsset : public LLTransferSourceParams
 {
@@ -56,7 +56,7 @@ public:
 	LLTransferSourceAsset(const LLUUID &request_id, const F32 priority);
 	virtual ~LLTransferSourceAsset();
 
-	static void responderCallback(const LLUUID& uuid, LLAssetType::EType type,
+	static void responderCallback(LLVFS *vfs, const LLUUID& uuid, LLAssetType::EType type,
 								  void *user_data, S32 result, LLExtStat ext_status );
 protected:
 	/*virtual*/ void initTransfer();
diff --git a/indra/llmessage/lltransfertargetvfile.cpp b/indra/llmessage/lltransfertargetvfile.cpp
index f6faadf87f..b27f0881e0 100644
--- a/indra/llmessage/lltransfertargetvfile.cpp
+++ b/indra/llmessage/lltransfertargetvfile.cpp
@@ -30,7 +30,7 @@
 
 #include "lldatapacker.h"
 #include "llerror.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 
 //static
 void LLTransferTargetVFile::updateQueue(bool shutdown)
@@ -138,9 +138,10 @@ LLTSCode LLTransferTargetVFile::dataCallback(const S32 packet_id, U8 *in_datap,
 	//LL_INFOS() << "LLTransferTargetFile::dataCallback" << LL_ENDL;
 	//LL_INFOS() << "Packet: " << packet_id << LL_ENDL;
 
-	LLFileSystem vf(mTempID, mParams.getAssetType(), LLFileSystem::APPEND);
+	LLVFile vf(gAssetStorage->mVFS, mTempID, mParams.getAssetType(), LLVFile::APPEND);
 	if (mNeedsCreate)
 	{
+		vf.setMaxSize(mSize);
 		mNeedsCreate = FALSE;
 	}
 
@@ -175,7 +176,7 @@ void LLTransferTargetVFile::completionCallback(const LLTSCode status)
 	  case LLTS_DONE:
 		if (!mNeedsCreate)
 		{
-			LLFileSystem file(mTempID, mParams.getAssetType(), LLFileSystem::WRITE);
+			LLVFile file(gAssetStorage->mVFS, mTempID, mParams.getAssetType(), LLVFile::WRITE);
 			if (!file.rename(mParams.getAssetID(), mParams.getAssetType()))
 			{
 				LL_ERRS() << "LLTransferTargetVFile: rename failed" << LL_ENDL;
@@ -194,7 +195,7 @@ void LLTransferTargetVFile::completionCallback(const LLTSCode status)
 	  {
 		  // We're aborting this transfer, we don't want to keep this file.
 		  LL_WARNS() << "Aborting vfile transfer for " << mParams.getAssetID() << LL_ENDL;
-		  LLFileSystem vf(mTempID, mParams.getAssetType(), LLFileSystem::APPEND);
+		  LLVFile vf(gAssetStorage->mVFS, mTempID, mParams.getAssetType(), LLVFile::APPEND);
 		  vf.remove();
 	  }
 	  break;
diff --git a/indra/llmessage/lltransfertargetvfile.h b/indra/llmessage/lltransfertargetvfile.h
index 39a9125f1b..c819c1e2f2 100644
--- a/indra/llmessage/lltransfertargetvfile.h
+++ b/indra/llmessage/lltransfertargetvfile.h
@@ -29,9 +29,9 @@
 
 #include "lltransfermanager.h"
 #include "llassetstorage.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 
-class LLFileSystem;
+class LLVFile;
 
 // Lame, an S32 for now until I figure out the deal with how we want to do
 // error codes.
diff --git a/indra/llmessage/llxfer_vfile.cpp b/indra/llmessage/llxfer_vfile.cpp
index 12419b342d..ddc24342f6 100644
--- a/indra/llmessage/llxfer_vfile.cpp
+++ b/indra/llmessage/llxfer_vfile.cpp
@@ -30,7 +30,8 @@
 #include "lluuid.h"
 #include "llerror.h"
 #include "llmath.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "lldir.h"
 
 // size of chunks read from/written to disk
@@ -41,13 +42,13 @@ const U32 LL_MAX_XFER_FILE_BUFFER = 65536;
 LLXfer_VFile::LLXfer_VFile ()
 : LLXfer(-1)
 {
-	init(LLUUID::null, LLAssetType::AT_NONE);
+	init(NULL, LLUUID::null, LLAssetType::AT_NONE);
 }
 
-LLXfer_VFile::LLXfer_VFile (const LLUUID &local_id, LLAssetType::EType type)
+LLXfer_VFile::LLXfer_VFile (LLVFS *vfs, const LLUUID &local_id, LLAssetType::EType type)
 : LLXfer(-1)
 {
-	init(local_id, type);
+	init(vfs, local_id, type);
 }
 
 ///////////////////////////////////////////////////////////
@@ -59,8 +60,10 @@ LLXfer_VFile::~LLXfer_VFile ()
 
 ///////////////////////////////////////////////////////////
 
-void LLXfer_VFile::init (const LLUUID &local_id, LLAssetType::EType type)
+void LLXfer_VFile::init (LLVFS *vfs, const LLUUID &local_id, LLAssetType::EType type)
 {
+
+	mVFS = vfs;
 	mLocalID = local_id;
 	mType = type;
 
@@ -79,14 +82,14 @@ void LLXfer_VFile::cleanup ()
 	if (mTempID.notNull() &&
 		mDeleteTempFile)
 	{
-		if (LLFileSystem::getExists(mTempID, mType))
+		if (mVFS->getExists(mTempID, mType))
 		{
-			LLFileSystem file(mTempID, mType, LLFileSystem::WRITE);
+			LLVFile file(mVFS, mTempID, mType, LLVFile::WRITE);
 			file.remove();
 		}
 		else
 		{
-			LL_WARNS("Xfer") << "LLXfer_VFile::cleanup() can't open to delete cache file " << mTempID << "." << LLAssetType::lookup(mType)		
+			LL_WARNS("Xfer") << "LLXfer_VFile::cleanup() can't open to delete VFS file " << mTempID << "." << LLAssetType::lookup(mType)		
 				<< ", mRemoteID is " << mRemoteID << LL_ENDL;
 		}
 	}
@@ -100,6 +103,7 @@ void LLXfer_VFile::cleanup ()
 ///////////////////////////////////////////////////////////
 
 S32 LLXfer_VFile::initializeRequest(U64 xfer_id,
+									LLVFS* vfs,
 									const LLUUID& local_id,
 									const LLUUID& remote_id,
 									LLAssetType::EType type,
@@ -111,6 +115,7 @@ S32 LLXfer_VFile::initializeRequest(U64 xfer_id,
 	
 	mRemoteHost = remote_host;
 
+	mVFS = vfs;
 	mLocalID = local_id;
 	mRemoteID = remote_id;
 	mType = type;
@@ -187,13 +192,13 @@ S32 LLXfer_VFile::startSend (U64 xfer_id, const LLHost &remote_host)
 	
 	delete mVFile;
 	mVFile = NULL;
-	if(LLFileSystem::getExists(mLocalID, mType))
+	if(mVFS->getExists(mLocalID, mType))
 	{
-		mVFile = new LLFileSystem(mLocalID, mType, LLFileSystem::READ);
+		mVFile = new LLVFile(mVFS, mLocalID, mType, LLVFile::READ);
 
 		if (mVFile->getSize() <= 0)
 		{
-			LL_WARNS("Xfer") << "LLXfer_VFile::startSend() cache file " << mLocalID << "." << LLAssetType::lookup(mType)		
+			LL_WARNS("Xfer") << "LLXfer_VFile::startSend() VFS file " << mLocalID << "." << LLAssetType::lookup(mType)		
 				<< " has unexpected file size of " << mVFile->getSize() << LL_ENDL;
 			delete mVFile;
 			mVFile = NULL;
@@ -209,7 +214,7 @@ S32 LLXfer_VFile::startSend (U64 xfer_id, const LLHost &remote_host)
 	}
 	else
 	{
-		LL_WARNS("Xfer") << "LLXfer_VFile::startSend() can't read cache file " << mLocalID << "." << LLAssetType::lookup(mType) << LL_ENDL;
+		LL_WARNS("Xfer") << "LLXfer_VFile::startSend() can't read VFS file " << mLocalID << "." << LLAssetType::lookup(mType) << LL_ENDL;
 		retval = LL_ERR_FILE_NOT_FOUND;
 	}
 
@@ -235,13 +240,13 @@ S32 LLXfer_VFile::reopenFileHandle()
 
 	if (mVFile == NULL)
 	{
-		if (LLFileSystem::getExists(mLocalID, mType))
+		if (mVFS->getExists(mLocalID, mType))
 		{
-			mVFile = new LLFileSystem(mLocalID, mType, LLFileSystem::READ);
+			mVFile = new LLVFile(mVFS, mLocalID, mType, LLVFile::READ);
 		}
 		else
 		{
-			LL_WARNS("Xfer") << "LLXfer_VFile::reopenFileHandle() can't read cache file " << mLocalID << "." << LLAssetType::lookup(mType) << LL_ENDL;
+			LL_WARNS("Xfer") << "LLXfer_VFile::reopenFileHandle() can't read VFS file " << mLocalID << "." << LLAssetType::lookup(mType) << LL_ENDL;
 			retval = LL_ERR_FILE_NOT_FOUND;
 		}
 	}
@@ -260,7 +265,8 @@ void LLXfer_VFile::setXferSize (S32 xfer_size)
 	// It would be nice if LLXFers could tell which end of the pipe they were
 	if (! mVFile)
 	{
-		LLFileSystem file(mTempID, mType, LLFileSystem::APPEND);
+		LLVFile file(mVFS, mTempID, mType, LLVFile::APPEND);
+		file.setMaxSize(xfer_size);
 	}
 }
 
@@ -314,7 +320,7 @@ S32 LLXfer_VFile::flush()
 	S32 retval = 0;
 	if (mBufferLength)
 	{
-		LLFileSystem file(mTempID, mType, LLFileSystem::APPEND);
+		LLVFile file(mVFS, mTempID, mType, LLVFile::APPEND);
 
 		file.write((U8*)mBuffer, mBufferLength);
 			
@@ -334,15 +340,22 @@ S32 LLXfer_VFile::processEOF()
 
 	if (!mCallbackResult)
 	{
-		if (LLFileSystem::getExists(mTempID, mType))
+		if (mVFS->getExists(mTempID, mType))
 		{
-			LLFileSystem file(mTempID, mType, LLFileSystem::WRITE);
+			LLVFile file(mVFS, mTempID, mType, LLVFile::WRITE);
 			if (!file.rename(mLocalID, mType))
 			{
-				LL_WARNS("Xfer") << "Cache rename of temp file failed: unable to rename " << mTempID << " to " << mLocalID << LL_ENDL;
+				LL_WARNS("Xfer") << "VFS rename of temp file failed: unable to rename " << mTempID << " to " << mLocalID << LL_ENDL;
 			}
 			else
-			{									
+			{					
+				#ifdef VFS_SPAM
+				// Debugging spam
+				LL_INFOS("Xfer") << "VFS rename of temp file done: renamed " << mTempID << " to " << mLocalID 
+					<< " LLVFile size is " << file.getSize()
+					<< LL_ENDL;
+				#endif				
+				
 				// Rename worked: the original file is gone.   Clear mDeleteTempFile
 				// so we don't attempt to delete the file in cleanup()
 				mDeleteTempFile = FALSE;
@@ -350,7 +363,7 @@ S32 LLXfer_VFile::processEOF()
 		}
 		else
 		{
-			LL_WARNS("Xfer") << "LLXfer_VFile::processEOF() can't open for renaming cache file " << mTempID << "." << LLAssetType::lookup(mType) << LL_ENDL;
+			LL_WARNS("Xfer") << "LLXfer_VFile::processEOF() can't open for renaming VFS file " << mTempID << "." << LLAssetType::lookup(mType) << LL_ENDL;
 		}
 	}
 
diff --git a/indra/llmessage/llxfer_vfile.h b/indra/llmessage/llxfer_vfile.h
index d82bab5f6c..5bf9a5cfba 100644
--- a/indra/llmessage/llxfer_vfile.h
+++ b/indra/llmessage/llxfer_vfile.h
@@ -30,7 +30,8 @@
 #include "llxfer.h"
 #include "llassetstorage.h"
 
-class LLFileSystem;
+class LLVFS;
+class LLVFile;
 
 class LLXfer_VFile : public LLXfer
 {
@@ -40,7 +41,9 @@ class LLXfer_VFile : public LLXfer
 	LLUUID mTempID;
 	LLAssetType::EType mType;
 	
-	LLFileSystem *mVFile;
+	LLVFile *mVFile;
+
+	LLVFS *mVFS;
 
 	std::string mName;
 
@@ -48,13 +51,14 @@ class LLXfer_VFile : public LLXfer
 
  public:
 	LLXfer_VFile ();
-	LLXfer_VFile (const LLUUID &local_id, LLAssetType::EType type);
+	LLXfer_VFile (LLVFS *vfs, const LLUUID &local_id, LLAssetType::EType type);
 	virtual ~LLXfer_VFile();
 
-	virtual void init(const LLUUID &local_id, LLAssetType::EType type);
+	virtual void init(LLVFS *vfs, const LLUUID &local_id, LLAssetType::EType type);
 	virtual void cleanup();
 
 	virtual S32 initializeRequest(U64 xfer_id,
+			LLVFS *vfs,
 			const LLUUID &local_id,
 			const LLUUID &remote_id,
 			const LLAssetType::EType type,
diff --git a/indra/llmessage/llxfermanager.cpp b/indra/llmessage/llxfermanager.cpp
index f9b59d7e42..4cea886c8a 100644
--- a/indra/llmessage/llxfermanager.cpp
+++ b/indra/llmessage/llxfermanager.cpp
@@ -56,9 +56,9 @@ const S32 LL_DEFAULT_MAX_HARD_LIMIT_SIMULTANEOUS_XFERS = 500;
 
 ///////////////////////////////////////////////////////////
 
-LLXferManager::LLXferManager ()
+LLXferManager::LLXferManager (LLVFS *vfs)
 {
-	init();
+	init(vfs);
 }
 
 ///////////////////////////////////////////////////////////
@@ -70,7 +70,7 @@ LLXferManager::~LLXferManager ()
 
 ///////////////////////////////////////////////////////////
 
-void LLXferManager::init()
+void LLXferManager::init (LLVFS *vfs)
 {
 	cleanup();
 
@@ -78,6 +78,8 @@ void LLXferManager::init()
 	setHardLimitOutgoingXfersPerCircuit(LL_DEFAULT_MAX_HARD_LIMIT_SIMULTANEOUS_XFERS);
 	setMaxIncomingXfers(LL_DEFAULT_MAX_REQUEST_FIFO_XFERS);
 
+	mVFS = vfs;
+
 	// Turn on or off ack throttling
 	mUseAckThrottling = FALSE;
 	setAckThrottleBPS(100000);
@@ -460,7 +462,7 @@ U64 LLXferManager::requestFile(const std::string& local_filename,
 
 void LLXferManager::requestVFile(const LLUUID& local_id,
 								 const LLUUID& remote_id,
-								 LLAssetType::EType type,
+								 LLAssetType::EType type, LLVFS* vfs,
 								 const LLHost& remote_host,
 								 void (*callback)(void**,S32,LLExtStat),
 								 void** user_data,
@@ -506,6 +508,7 @@ void LLXferManager::requestVFile(const LLUUID& local_id,
 
 		addToList(xfer_p, mReceiveList, is_priority);
 		((LLXfer_VFile *)xfer_p)->initializeRequest(getNextID(),
+			vfs,
 			local_id,
 			remote_id,
 			type,
@@ -781,17 +784,33 @@ void LLXferManager::processFileRequest (LLMessageSystem *mesgsys, void ** /*user
 	LLXfer *xferp;
 
 	if (uuid != LLUUID::null)
-	{	// Request for an asset - use a cache file
+	{	// Request for an asset - use a VFS file
 		if(NULL == LLAssetType::lookup(type))
 		{
 			LL_WARNS("Xfer") << "Invalid type for xfer request: " << uuid << ":"
 					<< type_s16 << " to " << mesgsys->getSender() << LL_ENDL;
 			return;
 		}
+			
+		if (! mVFS)
+		{
+			LL_WARNS("Xfer") << "Attempt to send VFile w/o available VFS" << LL_ENDL;
+			return;
+		}
+
+		/* Present in fireengine, not used by viewer
+		if (!validateVFileForTransfer(uuid.asString()))
+		{
+			// it is up to the app sending the file to mark it for expected 
+			// transfer before the request arrives or it will be dropped
+			LL_WARNS("Xfer") << "SECURITY: Unapproved VFile '" << uuid << "'" << LL_ENDL;
+			return;
+		}
+		*/
 
 		LL_INFOS("Xfer") << "starting vfile transfer: " << uuid << "," << LLAssetType::lookup(type) << " to " << mesgsys->getSender() << LL_ENDL;
 
-		xferp = (LLXfer *)new LLXfer_VFile(uuid, type);
+		xferp = (LLXfer *)new LLXfer_VFile(mVFS, uuid, type);
 		if (xferp)
 		{
 			mSendList.push_front(xferp);
@@ -1254,9 +1273,9 @@ void LLXferManager::addToList(LLXfer* xferp, xfer_list_t & xfer_list, BOOL is_pr
 LLXferManager *gXferManager = NULL;
 
 
-void start_xfer_manager()
+void start_xfer_manager(LLVFS *vfs)
 {
-	gXferManager = new LLXferManager();
+	gXferManager = new LLXferManager(vfs);
 }
 
 void cleanup_xfer_manager()
diff --git a/indra/llmessage/llxfermanager.h b/indra/llmessage/llxfermanager.h
index f49209bed0..45ae2ffdd3 100644
--- a/indra/llmessage/llxfermanager.h
+++ b/indra/llmessage/llxfermanager.h
@@ -35,6 +35,7 @@
 
 //Forward declaration to avoid circular dependencies
 class LLXfer;
+class LLVFS;
 
 #include "llxfer.h"
 #include "message.h"
@@ -71,6 +72,9 @@ public:
 
 class LLXferManager
 {
+ private:
+	LLVFS *mVFS;
+
  protected:
 	S32    mMaxOutgoingXfersPerCircuit;
 	S32    mHardLimitOutgoingXfersPerCircuit;	// At this limit, kill off the connection
@@ -107,10 +111,10 @@ class LLXferManager
 	std::multiset<std::string> mExpectedVFileRequests;  // files that are authorized to be downloaded on top of
 
  public:
-	LLXferManager();
+	LLXferManager(LLVFS *vfs);
 	virtual ~LLXferManager();
 
-	virtual void init();
+	virtual void init(LLVFS *vfs);
 	virtual void cleanup();
 
 	void setUseAckThrottling(const BOOL use);
@@ -162,7 +166,7 @@ class LLXferManager
 // vfile requesting
 // .. to vfile
 	virtual void requestVFile(const LLUUID &local_id, const LLUUID& remote_id,
-							  LLAssetType::EType type,
+							  LLAssetType::EType type, LLVFS* vfs,
 							  const LLHost& remote_host,
 							  void (*callback)(void**,S32,LLExtStat), void** user_data,
 							  BOOL is_priority = FALSE);
@@ -209,7 +213,7 @@ class LLXferManager
 extern LLXferManager*	gXferManager;
 
 // initialization and garbage collection
-void start_xfer_manager();
+void start_xfer_manager(LLVFS *vfs);
 void cleanup_xfer_manager();
 
 // message system callbacks
diff --git a/indra/llrender/CMakeLists.txt b/indra/llrender/CMakeLists.txt
index baab09a104..47e7ad915b 100644
--- a/indra/llrender/CMakeLists.txt
+++ b/indra/llrender/CMakeLists.txt
@@ -9,9 +9,10 @@ include(LLCommon)
 include(LLImage)
 include(LLMath)
 include(LLRender)
+include(LLVFS)
 include(LLWindow)
 include(LLXML)
-include(LLFileSystem)
+include(LLVFS)
 
 include_directories(
     ${FREETYPE_INCLUDE_DIRS}
@@ -19,9 +20,10 @@ include_directories(
     ${LLIMAGE_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     )
 include_directories(SYSTEM
     ${LLCOMMON_SYSTEM_INCLUDE_DIRS}
@@ -102,8 +104,9 @@ if (BUILD_HEADLESS)
     ${LLIMAGE_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLRENDER_HEADLESS_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLWINDOW_HEADLESS_LIBRARIES}
     ${OPENGL_HEADLESS_LIBRARIES})
 
@@ -123,8 +126,9 @@ target_link_libraries(llrender
     ${LLCOMMON_LIBRARIES}
     ${LLIMAGE_LIBRARIES}
     ${LLMATH_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLWINDOW_LIBRARIES}
     ${FREETYPE_LIBRARIES}
     ${OPENGL_LIBRARIES})
diff --git a/indra/llui/CMakeLists.txt b/indra/llui/CMakeLists.txt
index 7401e6130a..cce618487b 100644
--- a/indra/llui/CMakeLists.txt
+++ b/indra/llui/CMakeLists.txt
@@ -13,7 +13,7 @@ include(LLCoreHttp)
 include(LLRender)
 include(LLWindow)
 include(LLCoreHttp)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 
 include_directories(
@@ -25,7 +25,7 @@ include_directories(
     ${LLMESSAGE_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     ${LIBS_PREBUILD_DIR}/include/hunspell
     )
@@ -283,7 +283,7 @@ target_link_libraries(llui
     ${LLINVENTORY_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
     ${LLCOREHTTP_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}    # ugh, just for LLDir
     ${LLXUIXML_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMATH_LIBRARIES}
diff --git a/indra/llui/llviewereventrecorder.h b/indra/llui/llviewereventrecorder.h
index 94e66f5dc4..d1059d55de 100644
--- a/indra/llui/llviewereventrecorder.h
+++ b/indra/llui/llviewereventrecorder.h
@@ -32,6 +32,7 @@
 #include "lldir.h" 
 #include "llsd.h"  
 #include "llfile.h"
+#include "llvfile.h"
 #include "lldate.h"
 #include "llsdserialize.h"
 #include "llkeyboard.h"
diff --git a/indra/llfilesystem/CMakeLists.txt b/indra/llvfs/CMakeLists.txt
index 09c4c33ebf..67dce8c073 100644
--- a/indra/llfilesystem/CMakeLists.txt
+++ b/indra/llvfs/CMakeLists.txt
@@ -1,6 +1,6 @@
 # -*- cmake -*-
 
-project(llfilesystem)
+project(llvfs)
 
 include(00-Common)
 include(LLCommon)
@@ -11,34 +11,39 @@ include_directories(
     ${LLCOMMON_SYSTEM_INCLUDE_DIRS}
     )
 
-set(llfilesystem_SOURCE_FILES
+set(llvfs_SOURCE_FILES
     lldir.cpp
     lldiriterator.cpp
     lllfsthread.cpp
-    lldiskcache.cpp
-    llfilesystem.cpp
+    llpidlock.cpp
+    llvfile.cpp
+    llvfs.cpp
+    llvfsthread.cpp
     )
 
-set(llfilesystem_HEADER_FILES
+set(llvfs_HEADER_FILES
     CMakeLists.txt
+
     lldir.h
     lldirguard.h
     lldiriterator.h
     lllfsthread.h
-    lldiskcache.h
-    llfilesystem.h
+    llpidlock.h
+    llvfile.h
+    llvfs.h
+    llvfsthread.h
     )
 
 if (DARWIN)
-  LIST(APPEND llfilesystem_SOURCE_FILES lldir_utils_objc.mm)
-  LIST(APPEND llfilesystem_SOURCE_FILES lldir_utils_objc.h)
-  LIST(APPEND llfilesystem_SOURCE_FILES lldir_mac.cpp)
-  LIST(APPEND llfilesystem_HEADER_FILES lldir_mac.h)
+  LIST(APPEND llvfs_SOURCE_FILES lldir_mac.cpp)
+  LIST(APPEND llvfs_HEADER_FILES lldir_mac.h)
+  LIST(APPEND llvfs_SOURCE_FILES llvfs_objc.mm)
+  LIST(APPEND llvfs_HEADER_FILES llvfs_objc.h)
 endif (DARWIN)
 
 if (LINUX)
-  LIST(APPEND llfilesystem_SOURCE_FILES lldir_linux.cpp)
-  LIST(APPEND llfilesystem_HEADER_FILES lldir_linux.h)
+  LIST(APPEND llvfs_SOURCE_FILES lldir_linux.cpp)
+  LIST(APPEND llvfs_HEADER_FILES lldir_linux.h)
 
   if (INSTALL)
     set_source_files_properties(lldir_linux.cpp
@@ -49,31 +54,31 @@ if (LINUX)
 endif (LINUX)
 
 if (WINDOWS)
-  LIST(APPEND llfilesystem_SOURCE_FILES lldir_win32.cpp)
-  LIST(APPEND llfilesystem_HEADER_FILES lldir_win32.h)
+  LIST(APPEND llvfs_SOURCE_FILES lldir_win32.cpp)
+  LIST(APPEND llvfs_HEADER_FILES lldir_win32.h)
 endif (WINDOWS)
 
-set_source_files_properties(${llfilesystem_HEADER_FILES}
+set_source_files_properties(${llvfs_HEADER_FILES}
                             PROPERTIES HEADER_FILE_ONLY TRUE)
 
-list(APPEND llfilesystem_SOURCE_FILES ${llfilesystem_HEADER_FILES})
+list(APPEND llvfs_SOURCE_FILES ${llvfs_HEADER_FILES})
 
-add_library (llfilesystem ${llfilesystem_SOURCE_FILES})
+add_library (llvfs ${llvfs_SOURCE_FILES})
 
-set(cache_BOOST_LIBRARIES
+set(vfs_BOOST_LIBRARIES
     ${BOOST_FILESYSTEM_LIBRARY}
     ${BOOST_SYSTEM_LIBRARY}
     )
 
-target_link_libraries(llfilesystem
+target_link_libraries(llvfs
     ${LLCOMMON_LIBRARIES}
-    ${cache_BOOST_LIBRARIES}
+    ${vfs_BOOST_LIBRARIES}
     )
 
 if (DARWIN)
   include(CMakeFindFrameworks)
   find_library(COCOA_LIBRARY Cocoa)
-  target_link_libraries(llfilesystem ${COCOA_LIBRARY})
+  target_link_libraries(llvfs ${COCOA_LIBRARY})
 endif (DARWIN)
 
 
@@ -81,18 +86,18 @@ endif (DARWIN)
 if (LL_TESTS)
     include(LLAddBuildTest)
     # UNIT TESTS
-    SET(llfilesystem_TEST_SOURCE_FILES
+    SET(llvfs_TEST_SOURCE_FILES
     lldiriterator.cpp
     )
 
     set_source_files_properties(lldiriterator.cpp
     PROPERTIES
-    LL_TEST_ADDITIONAL_LIBRARIES "${cache_BOOST_LIBRARIES}"
+    LL_TEST_ADDITIONAL_LIBRARIES "${vfs_BOOST_LIBRARIES}"
     )
-    LL_ADD_PROJECT_UNIT_TESTS(llfilesystem "${llfilesystem_TEST_SOURCE_FILES}")
+    LL_ADD_PROJECT_UNIT_TESTS(llvfs "${llvfs_TEST_SOURCE_FILES}")
 
     # INTEGRATION TESTS
-    set(test_libs llmath llcommon llfilesystem ${LLCOMMON_LIBRARIES} ${WINDOWS_LIBRARIES})
+    set(test_libs llmath llcommon llvfs ${LLCOMMON_LIBRARIES} ${WINDOWS_LIBRARIES})
 
     # TODO: Some of these need refactoring to be proper Unit tests rather than Integration tests.
     LL_ADD_INTEGRATION_TEST(lldir "" "${test_libs}")
diff --git a/indra/llfilesystem/lldir.cpp b/indra/llvfs/lldir.cpp
index 10fbc06c61..10fbc06c61 100644
--- a/indra/llfilesystem/lldir.cpp
+++ b/indra/llvfs/lldir.cpp
diff --git a/indra/llfilesystem/lldir.h b/indra/llvfs/lldir.h
index 38e204ef04..38e204ef04 100644
--- a/indra/llfilesystem/lldir.h
+++ b/indra/llvfs/lldir.h
diff --git a/indra/llfilesystem/lldir_linux.cpp b/indra/llvfs/lldir_linux.cpp
index 80ad05345a..80ad05345a 100644
--- a/indra/llfilesystem/lldir_linux.cpp
+++ b/indra/llvfs/lldir_linux.cpp
diff --git a/indra/llfilesystem/lldir_linux.h b/indra/llvfs/lldir_linux.h
index e83a020ba4..e83a020ba4 100644
--- a/indra/llfilesystem/lldir_linux.h
+++ b/indra/llvfs/lldir_linux.h
diff --git a/indra/llfilesystem/lldir_mac.cpp b/indra/llvfs/lldir_mac.cpp
index 3bc4ee844e..87dc1b9795 100644
--- a/indra/llfilesystem/lldir_mac.cpp
+++ b/indra/llvfs/lldir_mac.cpp
@@ -36,7 +36,7 @@
 #include <unistd.h>
 #include <glob.h>
 #include <boost/filesystem.hpp>
-#include "lldir_utils_objc.h"
+#include "llvfs_objc.h"
 
 // --------------------------------------------------------------------------------
 
diff --git a/indra/llfilesystem/lldir_mac.h b/indra/llvfs/lldir_mac.h
index 558727ebbc..558727ebbc 100644
--- a/indra/llfilesystem/lldir_mac.h
+++ b/indra/llvfs/lldir_mac.h
diff --git a/indra/llfilesystem/lldir_solaris.cpp b/indra/llvfs/lldir_solaris.cpp
index f18560ff20..f18560ff20 100644
--- a/indra/llfilesystem/lldir_solaris.cpp
+++ b/indra/llvfs/lldir_solaris.cpp
diff --git a/indra/llfilesystem/lldir_solaris.h b/indra/llvfs/lldir_solaris.h
index c6dac57e14..c6dac57e14 100644
--- a/indra/llfilesystem/lldir_solaris.h
+++ b/indra/llvfs/lldir_solaris.h
diff --git a/indra/llfilesystem/lldir_win32.cpp b/indra/llvfs/lldir_win32.cpp
index b3b3afb37e..b3b3afb37e 100644
--- a/indra/llfilesystem/lldir_win32.cpp
+++ b/indra/llvfs/lldir_win32.cpp
diff --git a/indra/llfilesystem/lldir_win32.h b/indra/llvfs/lldir_win32.h
index 450efaf9da..450efaf9da 100644
--- a/indra/llfilesystem/lldir_win32.h
+++ b/indra/llvfs/lldir_win32.h
diff --git a/indra/llfilesystem/lldirguard.h b/indra/llvfs/lldirguard.h
index 37b9e9b83e..37b9e9b83e 100644
--- a/indra/llfilesystem/lldirguard.h
+++ b/indra/llvfs/lldirguard.h
diff --git a/indra/llfilesystem/lldiriterator.cpp b/indra/llvfs/lldiriterator.cpp
index 3eb64e69d9..3eb64e69d9 100644
--- a/indra/llfilesystem/lldiriterator.cpp
+++ b/indra/llvfs/lldiriterator.cpp
diff --git a/indra/llfilesystem/lldiriterator.h b/indra/llvfs/lldiriterator.h
index 0b48be41b3..0b48be41b3 100644
--- a/indra/llfilesystem/lldiriterator.h
+++ b/indra/llvfs/lldiriterator.h
diff --git a/indra/llfilesystem/lllfsthread.cpp b/indra/llvfs/lllfsthread.cpp
index be8e83a56f..be8e83a56f 100644
--- a/indra/llfilesystem/lllfsthread.cpp
+++ b/indra/llvfs/lllfsthread.cpp
diff --git a/indra/llfilesystem/lllfsthread.h b/indra/llvfs/lllfsthread.h
index 58f658f7ba..58f658f7ba 100644
--- a/indra/llfilesystem/lllfsthread.h
+++ b/indra/llvfs/lllfsthread.h
diff --git a/indra/llvfs/llpidlock.cpp b/indra/llvfs/llpidlock.cpp
new file mode 100644
index 0000000000..f770e93d45
--- /dev/null
+++ b/indra/llvfs/llpidlock.cpp
@@ -0,0 +1,276 @@
+/** 
+ * @file llformat.cpp
+ * @date   January 2007
+ * @brief string formatting utility
+ *
+ * $LicenseInfo:firstyear=2007&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llapr.h" // thread-related functions
+#include "llpidlock.h"
+#include "lldir.h"
+#include "llsd.h"
+#include "llsdserialize.h"
+#include "llnametable.h"
+#include "llframetimer.h"
+
+#if LL_WINDOWS   //For windows platform.
+
+#include <windows.h>
+
+bool isProcessAlive(U32 pid)
+{
+	return (bool) GetProcessVersion((DWORD)pid);
+}
+
+#else   //Everyone Else
+bool isProcessAlive(U32 pid)
+{   
+	return (bool) kill( (pid_t)pid, 0);
+}
+#endif //Everyone else.
+
+
+	
+class LLPidLockFile
+{
+	public:
+		LLPidLockFile( ) :
+			mAutosave(false),
+			mSaving(false),
+			mWaiting(false),
+			mPID(getpid()),
+			mNameTable(NULL),
+			mClean(true)
+		{
+			mLockName = gDirUtilp->getTempDir() + gDirUtilp->getDirDelimiter() + "savelock";
+		}
+		bool requestLock(LLNameTable<void *> *name_table, bool autosave,
+						bool force_immediate=FALSE, F32 timeout=300.0);
+		bool checkLock();
+		void releaseLock();
+
+	private:
+		void writeLockFile(LLSD pids);
+	public:
+		static LLPidLockFile& instance(); // return the singleton black list file
+			 
+		bool mAutosave;
+		bool mSaving;
+		bool mWaiting;
+		LLFrameTimer mTimer;
+		U32  mPID;
+		std::string mLockName;
+		std::string mSaveName;
+		LLSD mPIDS_sd;
+		LLNameTable<void*> *mNameTable;
+		bool mClean;
+};
+
+LLPidLockFile& LLPidLockFile::instance()
+{   
+	static LLPidLockFile the_file;
+	return the_file;
+}
+
+void LLPidLockFile::writeLockFile(LLSD pids)
+{
+	llofstream ofile(mLockName.c_str());
+
+	if (!LLSDSerialize::toXML(pids,ofile))
+	{
+		LL_WARNS() << "Unable to write concurrent save lock file." << LL_ENDL;
+	}
+	ofile.close();
+}
+
+bool LLPidLockFile::requestLock(LLNameTable<void *> *name_table, bool autosave,
+								bool force_immediate, F32 timeout)
+{
+	bool readyToSave = FALSE;
+
+	if (mSaving) return FALSE;	//Bail out if we're currently saving.  Will not queue another save.
+	
+	if (!mWaiting){
+		mNameTable=name_table;
+		mAutosave = autosave;
+	}
+
+	LLSD out_pids;
+	out_pids.append( (LLSD::Integer)mPID );
+
+	llifstream ifile(mLockName.c_str());
+
+	if (ifile.is_open()) 
+	{									//If file exists, we need to decide whether or not to continue.
+		if ( force_immediate
+			|| mTimer.hasExpired() )	//Only deserialize if we REALLY need to.
+		{
+
+			LLSD in_pids;
+
+			LLSDSerialize::fromXML(in_pids, ifile);	
+
+			//Clean up any dead PIDS that might be in there.
+			for (LLSD::array_iterator i=in_pids.beginArray();
+				i !=in_pids.endArray();
+				++i)
+			{
+				U32 stored_pid=(*i).asInteger();
+
+				if (isProcessAlive(stored_pid))
+				{
+					out_pids.append( (*i) );
+				}
+			}
+
+			readyToSave=TRUE;
+		}
+		ifile.close();
+	}
+	else
+	{
+		readyToSave=TRUE;
+	}
+
+	if (!mWaiting)				//Not presently waiting to save.  Queue up.
+	{
+		mTimer.resetWithExpiry(timeout);
+		mWaiting=TRUE;
+	}
+
+	if (readyToSave)
+	{	//Potential race condition won't kill us. Ignore it.
+		writeLockFile(out_pids);
+		mSaving=TRUE;
+	}
+	
+	return readyToSave;
+}
+
+bool LLPidLockFile::checkLock()
+{
+	return mWaiting;
+}
+
+void LLPidLockFile::releaseLock()
+{
+	llifstream ifile(mLockName.c_str());
+	LLSD in_pids;
+	LLSD out_pids;
+	bool write_file=FALSE;
+
+	LLSDSerialize::fromXML(in_pids, ifile);	
+
+	//Clean up this PID and any dead ones.
+	for (LLSD::array_iterator i=in_pids.beginArray();
+		i !=in_pids.endArray();
+		++i)
+	{
+		U32 stored_pid=(*i).asInteger();
+
+		if (stored_pid != mPID && isProcessAlive(stored_pid))
+		{
+			out_pids.append( (*i) );
+			write_file=TRUE;
+		}
+	}
+	ifile.close();
+
+	if (write_file)
+	{
+		writeLockFile(out_pids);
+	}
+	else
+	{
+		unlink(mLockName.c_str());
+	}
+
+	mSaving=FALSE;
+	mWaiting=FALSE;
+}
+
+//LLPidLock
+
+void LLPidLock::initClass() { 
+	(void) LLPidLockFile::instance(); 
+}
+
+bool LLPidLock::checkLock() 
+{
+	return LLPidLockFile::instance().checkLock();
+}
+
+bool LLPidLock::requestLock(LLNameTable<void *> *name_table, bool autosave,
+								bool force_immediate, F32 timeout)
+{
+	return LLPidLockFile::instance().requestLock(name_table,autosave,force_immediate,timeout);
+}
+
+void LLPidLock::releaseLock() 
+{ 
+	return LLPidLockFile::instance().releaseLock(); 
+}
+
+bool LLPidLock::isClean() 
+{ 
+	return LLPidLockFile::instance().mClean; 
+}
+
+//getters
+LLNameTable<void *> * LLPidLock::getNameTable() 
+{ 
+    return LLPidLockFile::instance().mNameTable; 
+}
+
+bool LLPidLock::getAutosave() 
+{ 
+	return LLPidLockFile::instance().mAutosave; 
+}
+
+bool LLPidLock::getClean() 
+{ 
+	return LLPidLockFile::instance().mClean; 
+}
+
+std::string LLPidLock::getSaveName() 
+{ 
+	return LLPidLockFile::instance().mSaveName; 
+}
+
+//setters
+void LLPidLock::setClean(bool clean) 
+{ 
+	LLPidLockFile::instance().mClean=clean; 
+}
+
+void LLPidLock::setSaveName(std::string savename) 
+{ 
+	LLPidLockFile::instance().mSaveName=savename; 
+}
+
+S32 LLPidLock::getPID()
+{
+    return (S32)getpid();
+}
diff --git a/indra/llvfs/llpidlock.h b/indra/llvfs/llpidlock.h
new file mode 100644
index 0000000000..334f26bb29
--- /dev/null
+++ b/indra/llvfs/llpidlock.h
@@ -0,0 +1,60 @@
+/** 
+ * @file llpidlock.h
+ * @brief System information debugging classes.
+ *
+ * $LicenseInfo:firstyear=2001&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_PIDLOCK_H
+#define LL_PIDLOCK_H
+#include "llnametable.h"
+
+class LLSD;
+class LLFrameTimer;
+
+#if !LL_WINDOWS	//For non-windows platforms.
+#include <signal.h>
+#endif
+
+namespace LLPidLock
+{
+    void initClass(); // { (void) LLPidLockFile::instance(); }
+
+    bool requestLock( LLNameTable<void *> *name_table=NULL, bool autosave=TRUE,
+                     bool force_immediate=FALSE, F32 timeout=300.0);
+    bool checkLock();
+    void releaseLock();
+    bool isClean();
+
+    //getters
+    LLNameTable<void *> * getNameTable();
+    bool getAutosave();
+    bool getClean();
+    std::string getSaveName();
+    S32 getPID();
+
+    //setters
+    void setClean(bool clean);
+    void setSaveName(std::string savename);
+};
+
+#endif // LL_PIDLOCK_H
diff --git a/indra/llvfs/llvfile.cpp b/indra/llvfs/llvfile.cpp
new file mode 100644
index 0000000000..b8588e99f4
--- /dev/null
+++ b/indra/llvfs/llvfile.cpp
@@ -0,0 +1,437 @@
+/** 
+ * @file llvfile.cpp
+ * @brief Implementation of virtual file
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llvfile.h"
+
+#include "llerror.h"
+#include "llthread.h"
+#include "lltimer.h"
+#include "llfasttimer.h"
+#include "llmemory.h"
+#include "llvfs.h"
+
+const S32 LLVFile::READ			= 0x00000001;
+const S32 LLVFile::WRITE		= 0x00000002;
+const S32 LLVFile::READ_WRITE	= 0x00000003;  // LLVFile::READ & LLVFile::WRITE
+const S32 LLVFile::APPEND		= 0x00000006;  // 0x00000004 & LLVFile::WRITE
+
+static LLTrace::BlockTimerStatHandle FTM_VFILE_WAIT("VFile Wait");
+
+//----------------------------------------------------------------------------
+LLVFSThread* LLVFile::sVFSThread = NULL;
+BOOL LLVFile::sAllocdVFSThread = FALSE;
+//----------------------------------------------------------------------------
+
+//============================================================================
+
+LLVFile::LLVFile(LLVFS *vfs, const LLUUID &file_id, const LLAssetType::EType file_type, S32 mode)
+{
+	mFileType =	file_type;
+
+	mFileID =	file_id;
+	mPosition = 0;
+	mMode =		mode;
+	mVFS =		vfs;
+
+	mBytesRead = 0;
+	mHandle = LLVFSThread::nullHandle();
+	mPriority = 128.f;
+
+	mVFS->incLock(mFileID, mFileType, VFSLOCK_OPEN);
+}
+
+LLVFile::~LLVFile()
+{
+	if (!isReadComplete())
+	{
+		if (mHandle != LLVFSThread::nullHandle())
+		{
+			if (!(mMode & LLVFile::WRITE))
+			{
+				//LL_WARNS() << "Destroying LLVFile with pending async read/write, aborting..." << LL_ENDL;
+				sVFSThread->setFlags(mHandle, LLVFSThread::FLAG_AUTO_COMPLETE | LLVFSThread::FLAG_ABORT);
+			}
+			else // WRITE
+			{
+				sVFSThread->setFlags(mHandle, LLVFSThread::FLAG_AUTO_COMPLETE);
+			}
+		}
+	}
+	mVFS->decLock(mFileID, mFileType, VFSLOCK_OPEN);
+}
+
+BOOL LLVFile::read(U8 *buffer, S32 bytes, BOOL async, F32 priority)
+{
+	if (! (mMode & READ))
+	{
+		LL_WARNS() << "Attempt to read from file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << LL_ENDL;
+		return FALSE;
+	}
+
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		LL_WARNS() << "Attempt to read from vfile object " << mFileID << " with pending async operation" << LL_ENDL;
+		return FALSE;
+	}
+	mPriority = priority;
+	
+	BOOL success = TRUE;
+
+	// We can't do a read while there are pending async writes
+	waitForLock(VFSLOCK_APPEND);
+	
+	// *FIX: (?)
+	if (async)
+	{
+		mHandle = sVFSThread->read(mVFS, mFileID, mFileType, buffer, mPosition, bytes, threadPri());
+	}
+	else
+	{
+		// We can't do a read while there are pending async writes on this file
+		mBytesRead = sVFSThread->readImmediate(mVFS, mFileID, mFileType, buffer, mPosition, bytes);
+		mPosition += mBytesRead;
+		if (! mBytesRead)
+		{
+			success = FALSE;
+		}
+	}
+
+	return success;
+}
+
+//static
+U8* LLVFile::readFile(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type, S32* bytes_read)
+{
+	U8 *data;
+	LLVFile file(vfs, uuid, type, LLVFile::READ);
+	S32 file_size = file.getSize();
+	if (file_size == 0)
+	{
+		// File is empty.
+		data = NULL;
+	}
+	else
+	{		
+		data = (U8*) ll_aligned_malloc<16>(file_size);
+		file.read(data, file_size);	/* Flawfinder: ignore */ 
+		
+		if (file.getLastBytesRead() != (S32)file_size)
+		{
+			ll_aligned_free<16>(data);
+			data = NULL;
+			file_size = 0;
+		}
+	}
+	if (bytes_read)
+	{
+		*bytes_read = file_size;
+	}
+	return data;
+}
+	
+void LLVFile::setReadPriority(const F32 priority)
+{
+	mPriority = priority;
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		sVFSThread->setPriority(mHandle, threadPri());
+	}
+}
+
+BOOL LLVFile::isReadComplete()
+{
+	BOOL res = TRUE;
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		LLVFSThread::Request* req = (LLVFSThread::Request*)sVFSThread->getRequest(mHandle);
+		LLVFSThread::status_t status = req->getStatus();
+		if (status == LLVFSThread::STATUS_COMPLETE)
+		{
+			mBytesRead = req->getBytesRead();
+			mPosition += mBytesRead;
+			sVFSThread->completeRequest(mHandle);
+			mHandle = LLVFSThread::nullHandle();
+		}
+		else
+		{
+			res = FALSE;
+		}
+	}
+	return res;
+}
+
+S32 LLVFile::getLastBytesRead()
+{
+	return mBytesRead;
+}
+
+BOOL LLVFile::eof()
+{
+	return mPosition >= getSize();
+}
+
+BOOL LLVFile::write(const U8 *buffer, S32 bytes)
+{
+	if (! (mMode & WRITE))
+	{
+		LL_WARNS() << "Attempt to write to file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << LL_ENDL;
+	}
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		LL_ERRS() << "Attempt to write to vfile object " << mFileID << " with pending async operation" << LL_ENDL;
+		return FALSE;
+	}
+	BOOL success = TRUE;
+	
+	// *FIX: allow async writes? potential problem wit mPosition...
+	if (mMode == APPEND) // all appends are async (but WRITEs are not)
+	{	
+		U8* writebuf = new U8[bytes];
+		memcpy(writebuf, buffer, bytes);
+		S32 offset = -1;
+		mHandle = sVFSThread->write(mVFS, mFileID, mFileType,
+									writebuf, offset, bytes,
+									LLVFSThread::FLAG_AUTO_COMPLETE | LLVFSThread::FLAG_AUTO_DELETE);
+		mHandle = LLVFSThread::nullHandle(); // FLAG_AUTO_COMPLETE means we don't track this
+	}
+	else
+	{
+		// We can't do a write while there are pending reads or writes on this file
+		waitForLock(VFSLOCK_READ);
+		waitForLock(VFSLOCK_APPEND);
+
+		S32 pos = (mMode & APPEND) == APPEND ? -1 : mPosition;
+
+		S32 wrote = sVFSThread->writeImmediate(mVFS, mFileID, mFileType, (U8*)buffer, pos, bytes);
+
+		mPosition += wrote;
+		
+		if (wrote < bytes)
+		{	
+			LL_WARNS() << "Tried to write " << bytes << " bytes, actually wrote " << wrote << LL_ENDL;
+
+			success = FALSE;
+		}
+	}
+	return success;
+}
+
+//static
+BOOL LLVFile::writeFile(const U8 *buffer, S32 bytes, LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type)
+{
+	LLVFile file(vfs, uuid, type, LLVFile::WRITE);
+	file.setMaxSize(bytes);
+	return file.write(buffer, bytes);
+}
+
+BOOL LLVFile::seek(S32 offset, S32 origin)
+{
+	if (mMode == APPEND)
+	{
+		LL_WARNS() << "Attempt to seek on append-only file" << LL_ENDL;
+		return FALSE;
+	}
+
+	if (-1 == origin)
+	{
+		origin = mPosition;
+	}
+
+	S32 new_pos = origin + offset;
+
+	S32 size = getSize(); // Calls waitForLock(VFSLOCK_APPEND)
+
+	if (new_pos > size)
+	{
+		LL_WARNS() << "Attempt to seek past end of file" << LL_ENDL;
+
+		mPosition = size;
+		return FALSE;
+	}
+	else if (new_pos < 0)
+	{
+		LL_WARNS() << "Attempt to seek past beginning of file" << LL_ENDL;
+
+		mPosition = 0;
+		return FALSE;
+	}
+
+	mPosition = new_pos;
+	return TRUE;
+}
+
+S32 LLVFile::tell() const
+{
+	return mPosition;
+}
+
+S32 LLVFile::getSize()
+{
+	waitForLock(VFSLOCK_APPEND);
+	S32 size = mVFS->getSize(mFileID, mFileType);
+
+	return size;
+}
+
+S32 LLVFile::getMaxSize()
+{
+	S32 size = mVFS->getMaxSize(mFileID, mFileType);
+
+	return size;
+}
+
+BOOL LLVFile::setMaxSize(S32 size)
+{
+	if (! (mMode & WRITE))
+	{
+		LL_WARNS() << "Attempt to change size of file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << LL_ENDL;
+
+		return FALSE;
+	}
+
+	if (!mVFS->checkAvailable(size))
+	{
+		//LL_RECORD_BLOCK_TIME(FTM_VFILE_WAIT);
+		S32 count = 0;
+		while (sVFSThread->getPending() > 1000)
+		{
+			if (count % 100 == 0)
+			{
+				LL_INFOS() << "VFS catching up... Pending: " << sVFSThread->getPending() << LL_ENDL;
+			}
+			if (sVFSThread->isPaused())
+			{
+				sVFSThread->update(0);
+			}
+			ms_sleep(10);
+		}
+	}
+	return mVFS->setMaxSize(mFileID, mFileType, size);
+}
+
+BOOL LLVFile::rename(const LLUUID &new_id, const LLAssetType::EType new_type)
+{
+	if (! (mMode & WRITE))
+	{
+		LL_WARNS() << "Attempt to rename file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << LL_ENDL;
+
+		return FALSE;
+	}
+
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		LL_WARNS() << "Renaming file with pending async read" << LL_ENDL;
+	}
+
+	waitForLock(VFSLOCK_READ);
+	waitForLock(VFSLOCK_APPEND);
+
+	// we need to release / replace our own lock
+	// since the renamed file will inherit locks from the new name
+	mVFS->decLock(mFileID, mFileType, VFSLOCK_OPEN);
+	mVFS->renameFile(mFileID, mFileType, new_id, new_type);
+	mVFS->incLock(new_id, new_type, VFSLOCK_OPEN);
+	
+	mFileID = new_id;
+	mFileType = new_type;
+
+	return TRUE;
+}
+
+BOOL LLVFile::remove()
+{
+// 	LL_INFOS() << "Removing file " << mFileID << LL_ENDL;
+	
+	if (! (mMode & WRITE))
+	{
+		// Leaving paranoia warning just because this should be a very infrequent
+		// operation.
+		LL_WARNS() << "Remove file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << LL_ENDL;
+	}
+
+	if (mHandle != LLVFSThread::nullHandle())
+	{
+		LL_WARNS() << "Removing file with pending async read" << LL_ENDL;
+	}
+	
+	// why not seek back to the beginning of the file too?
+	mPosition = 0;
+
+	waitForLock(VFSLOCK_READ);
+	waitForLock(VFSLOCK_APPEND);
+	mVFS->removeFile(mFileID, mFileType);
+
+	return TRUE;
+}
+
+// static
+void LLVFile::initClass(LLVFSThread* vfsthread)
+{
+	if (!vfsthread)
+	{
+		if (LLVFSThread::sLocal != NULL)
+		{
+			vfsthread = LLVFSThread::sLocal;
+		}
+		else
+		{
+			vfsthread = new LLVFSThread();
+			sAllocdVFSThread = TRUE;
+		}
+	}
+	sVFSThread = vfsthread;
+}
+
+// static
+void LLVFile::cleanupClass()
+{
+	if (sAllocdVFSThread)
+	{
+		delete sVFSThread;
+	}
+	sVFSThread = NULL;
+}
+
+bool LLVFile::isLocked(EVFSLock lock)
+{
+	return mVFS->isLocked(mFileID, mFileType, lock) ? true : false;
+}
+
+void LLVFile::waitForLock(EVFSLock lock)
+{
+	//LL_RECORD_BLOCK_TIME(FTM_VFILE_WAIT);
+	// spin until the lock clears
+	while (isLocked(lock))
+	{
+		if (sVFSThread->isPaused())
+		{
+			sVFSThread->update(0);
+		}
+		ms_sleep(1);
+	}
+}
diff --git a/indra/llvfs/llvfile.h b/indra/llvfs/llvfile.h
new file mode 100644
index 0000000000..7e9d9f73e5
--- /dev/null
+++ b/indra/llvfs/llvfile.h
@@ -0,0 +1,90 @@
+/** 
+ * @file llvfile.h
+ * @brief Definition of virtual file
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLVFILE_H
+#define LL_LLVFILE_H
+
+#include "lluuid.h"
+#include "llassettype.h"
+#include "llvfs.h"
+#include "llvfsthread.h"
+
+class LLVFile
+{
+public:
+	LLVFile(LLVFS *vfs, const LLUUID &file_id, const LLAssetType::EType file_type, S32 mode = LLVFile::READ);
+	~LLVFile();
+
+	BOOL read(U8 *buffer, S32 bytes, BOOL async = FALSE, F32 priority = 128.f);	/* Flawfinder: ignore */ 
+	static U8* readFile(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type, S32* bytes_read = 0);
+	void setReadPriority(const F32 priority);
+	BOOL isReadComplete();
+	S32  getLastBytesRead();
+	BOOL eof();
+
+	BOOL write(const U8 *buffer, S32 bytes);
+	static BOOL writeFile(const U8 *buffer, S32 bytes, LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type);
+	BOOL seek(S32 offset, S32 origin = -1);
+	S32  tell() const;
+
+	S32 getSize();
+	S32 getMaxSize();
+	BOOL setMaxSize(S32 size);
+	BOOL rename(const LLUUID &new_id, const LLAssetType::EType new_type);
+	BOOL remove();
+
+	bool isLocked(EVFSLock lock);
+	void waitForLock(EVFSLock lock);
+	
+	static void initClass(LLVFSThread* vfsthread = NULL);
+	static void cleanupClass();
+	static LLVFSThread* getVFSThread() { return sVFSThread; }
+
+protected:
+	static LLVFSThread* sVFSThread;
+	static BOOL sAllocdVFSThread;
+	U32 threadPri() { return LLVFSThread::PRIORITY_NORMAL + llmin((U32)mPriority,(U32)0xfff); }
+	
+public:
+	static const S32 READ;
+	static const S32 WRITE;
+	static const S32 READ_WRITE;
+	static const S32 APPEND;
+	
+protected:
+	LLAssetType::EType mFileType;
+
+	LLUUID	mFileID;
+	S32		mPosition;
+	S32		mMode;
+	LLVFS	*mVFS;
+	F32		mPriority;
+
+	S32		mBytesRead;
+	LLVFSThread::handle_t mHandle;
+};
+
+#endif
diff --git a/indra/llvfs/llvfs.cpp b/indra/llvfs/llvfs.cpp
new file mode 100644
index 0000000000..617056d94d
--- /dev/null
+++ b/indra/llvfs/llvfs.cpp
@@ -0,0 +1,2220 @@
+/** 
+ * @file llvfs.cpp
+ * @brief Implementation of virtual file system
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llvfs.h"
+
+#include <sys/stat.h>
+#include <set>
+#include <map>
+#if LL_WINDOWS
+#include <share.h>
+#elif LL_SOLARIS
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#else
+#include <sys/file.h>
+#endif
+    
+#include "llstl.h"
+#include "lltimer.h"
+    
+const S32 FILE_BLOCK_MASK = 0x000003FF;	 // 1024-byte blocks
+const S32 VFS_CLEANUP_SIZE = 5242880;  // how much space we free up in a single stroke
+const S32 BLOCK_LENGTH_INVALID = -1;	// mLength for invalid LLVFSFileBlocks
+
+LLVFS *gVFS = NULL;
+
+// internal class definitions
+class LLVFSBlock
+{
+public:
+	LLVFSBlock() 
+	{
+		mLocation = 0;
+		mLength = 0;
+	}
+    
+	LLVFSBlock(U32 loc, S32 size)
+	{
+		mLocation = loc;
+		mLength = size;
+	}
+    
+	static bool locationSortPredicate(
+		const LLVFSBlock* lhs,
+		const LLVFSBlock* rhs)
+	{
+		return lhs->mLocation < rhs->mLocation;
+	}
+
+public:
+	U32 mLocation;
+	S32	mLength;		// allocated block size
+};
+    
+LLVFSFileSpecifier::LLVFSFileSpecifier()
+:	mFileID(),
+	mFileType( LLAssetType::AT_NONE )
+{
+}
+    
+LLVFSFileSpecifier::LLVFSFileSpecifier(const LLUUID &file_id, const LLAssetType::EType file_type)
+{
+	mFileID = file_id;
+	mFileType = file_type;
+}
+    
+bool LLVFSFileSpecifier::operator<(const LLVFSFileSpecifier &rhs) const
+{
+	return (mFileID == rhs.mFileID)
+		? mFileType < rhs.mFileType
+		: mFileID < rhs.mFileID;
+}
+    
+bool LLVFSFileSpecifier::operator==(const LLVFSFileSpecifier &rhs) const
+{
+	return (mFileID == rhs.mFileID && 
+			mFileType == rhs.mFileType);
+}
+    
+    
+class LLVFSFileBlock : public LLVFSBlock, public LLVFSFileSpecifier
+{
+public:
+	LLVFSFileBlock() : LLVFSBlock(), LLVFSFileSpecifier()
+	{
+		init();
+	}
+    
+	LLVFSFileBlock(const LLUUID &file_id, LLAssetType::EType file_type, U32 loc = 0, S32 size = 0)
+		: LLVFSBlock(loc, size), LLVFSFileSpecifier( file_id, file_type )
+	{
+		init();
+	}
+
+	void init()
+	{
+		mSize = 0;
+		mIndexLocation = -1;
+		mAccessTime = (U32)time(NULL);
+
+		for (S32 i = 0; i < (S32)VFSLOCK_COUNT; i++)
+		{
+			mLocks[(EVFSLock)i] = 0;
+		}
+	}
+
+	#ifdef LL_LITTLE_ENDIAN
+	inline void swizzleCopy(void *dst, void *src, int size) { memcpy(dst, src, size); /* Flawfinder: ignore */}
+
+	#else
+	
+	inline U32 swizzle32(U32 x)
+	{
+		return(((x >> 24) & 0x000000FF) | ((x >> 8)  & 0x0000FF00) | ((x << 8)  & 0x00FF0000) |((x << 24) & 0xFF000000));
+	}
+	
+	inline U16 swizzle16(U16 x)
+	{
+		return(	((x >> 8)  & 0x000000FF) | ((x << 8)  & 0x0000FF00) );
+	}
+	
+	inline void swizzleCopy(void *dst, void *src, int size) 
+	{
+		if(size == 4)
+		{
+			((U32*)dst)[0] = swizzle32(((U32*)src)[0]); 
+		}
+		else if(size == 2)
+		{
+			((U16*)dst)[0] = swizzle16(((U16*)src)[0]); 
+		}
+		else
+		{
+			// Perhaps this should assert...
+			memcpy(dst, src, size);	/* Flawfinder: ignore */
+		}
+	}
+	
+	#endif
+
+	void serialize(U8 *buffer)
+	{
+		swizzleCopy(buffer, &mLocation, 4);
+		buffer += 4;
+		swizzleCopy(buffer, &mLength, 4);
+		buffer +=4;
+		swizzleCopy(buffer, &mAccessTime, 4);
+		buffer +=4;
+		memcpy(buffer, &mFileID.mData, 16); /* Flawfinder: ignore */	
+		buffer += 16;
+		S16 temp_type = mFileType;
+		swizzleCopy(buffer, &temp_type, 2);
+		buffer += 2;
+		swizzleCopy(buffer, &mSize, 4);
+	}
+    
+	void deserialize(U8 *buffer, const S32 index_loc)
+	{
+		mIndexLocation = index_loc;
+    
+		swizzleCopy(&mLocation, buffer, 4);
+		buffer += 4;
+		swizzleCopy(&mLength, buffer, 4);
+		buffer += 4;
+		swizzleCopy(&mAccessTime, buffer, 4);
+		buffer += 4;
+		memcpy(&mFileID.mData, buffer, 16);
+		buffer += 16;
+		S16 temp_type;
+		swizzleCopy(&temp_type, buffer, 2);
+		mFileType = (LLAssetType::EType)temp_type;
+		buffer += 2;
+		swizzleCopy(&mSize, buffer, 4);
+	}
+    
+	static BOOL insertLRU(LLVFSFileBlock* const& first,
+						  LLVFSFileBlock* const& second)
+	{
+		return (first->mAccessTime == second->mAccessTime)
+			? *first < *second
+			: first->mAccessTime < second->mAccessTime;
+	}
+    
+public:
+	S32  mSize;
+	S32  mIndexLocation; // location of index entry
+	U32  mAccessTime;
+	BOOL mLocks[VFSLOCK_COUNT]; // number of outstanding locks of each type
+    
+	static const S32 SERIAL_SIZE;
+};
+
+// Helper structure for doing lru w/ stl... is there a simpler way?
+struct LLVFSFileBlock_less
+{
+	bool operator()(LLVFSFileBlock* const& lhs, LLVFSFileBlock* const& rhs) const
+	{
+		return (LLVFSFileBlock::insertLRU(lhs, rhs)) ? true : false;
+	}
+};
+
+
+const S32 LLVFSFileBlock::SERIAL_SIZE = 34;
+     
+
+LLVFS::LLVFS(const std::string& index_filename, const std::string& data_filename, const BOOL read_only, const U32 presize, const BOOL remove_after_crash)
+:	mRemoveAfterCrash(remove_after_crash),
+	mDataFP(NULL),
+	mIndexFP(NULL)
+{
+	mDataMutex = new LLMutex();
+
+	S32 i;
+	for (i = 0; i < VFSLOCK_COUNT; i++)
+	{
+		mLockCounts[i] = 0;
+	}
+	mValid = VFSVALID_OK;
+	mReadOnly = read_only;
+	mIndexFilename = index_filename;
+	mDataFilename = data_filename;
+    
+	const char *file_mode = mReadOnly ? "rb" : "r+b";
+    
+	LL_INFOS("VFS") << "Attempting to open VFS index file " << mIndexFilename << LL_ENDL;
+	LL_INFOS("VFS") << "Attempting to open VFS data file " << mDataFilename << LL_ENDL;
+
+	mDataFP = openAndLock(mDataFilename, file_mode, mReadOnly);
+	if (!mDataFP)
+	{
+		if (mReadOnly)
+		{
+			LL_WARNS("VFS") << "Can't find " << mDataFilename << " to open read-only VFS" << LL_ENDL;
+			mValid = VFSVALID_BAD_CANNOT_OPEN_READONLY;
+			return;
+		}
+
+		mDataFP = openAndLock(mDataFilename, "w+b", FALSE);
+		if (mDataFP)
+		{
+			// Since we're creating this data file, assume any index file is bogus
+			// remove the index, since this vfs is now blank
+			LLFile::remove(mIndexFilename);
+		}
+		else
+		{
+			LL_WARNS("VFS") << "Couldn't open vfs data file " 
+				<< mDataFilename << LL_ENDL;
+			mValid = VFSVALID_BAD_CANNOT_CREATE;
+			return;
+		}
+
+		if (presize)
+		{
+			presizeDataFile(presize);
+		}
+	}
+
+	// Did we leave this file open for writing last time?
+	// If so, close it and start over.
+	if (!mReadOnly && mRemoveAfterCrash)
+	{
+		llstat marker_info;
+		std::string marker = mDataFilename + ".open";
+		if (!LLFile::stat(marker, &marker_info))
+		{
+			// marker exists, kill the lock and the VFS files
+			unlockAndClose(mDataFP);
+			mDataFP = NULL;
+
+			LL_WARNS("VFS") << "VFS: File left open on last run, removing old VFS file " << mDataFilename << LL_ENDL;
+			LLFile::remove(mIndexFilename);
+			LLFile::remove(mDataFilename);
+			LLFile::remove(marker);
+
+			mDataFP = openAndLock(mDataFilename, "w+b", FALSE);
+			if (!mDataFP)
+			{
+				LL_WARNS("VFS") << "Can't open VFS data file in crash recovery" << LL_ENDL;
+				mValid = VFSVALID_BAD_CANNOT_CREATE;
+				return;
+			}
+
+			if (presize)
+			{
+				presizeDataFile(presize);
+			}
+		}
+	}
+
+	// determine the real file size
+	fseek(mDataFP, 0, SEEK_END);
+	U32 data_size = ftell(mDataFP);
+
+	// read the index file
+	// make sure there's at least one file in it too
+	// if not, we'll treat this as a new vfs
+	llstat fbuf;
+	if (! LLFile::stat(mIndexFilename, &fbuf) &&
+		fbuf.st_size >= LLVFSFileBlock::SERIAL_SIZE &&
+		(mIndexFP = openAndLock(mIndexFilename, file_mode, mReadOnly))	// Yes, this is an assignment and not '=='
+		)
+	{	
+		std::vector<U8> buffer(fbuf.st_size);
+    		size_t buf_offset = 0;
+		size_t nread = fread(&buffer[0], 1, fbuf.st_size, mIndexFP);
+ 
+		std::vector<LLVFSFileBlock*> files_by_loc;
+		
+		while (buf_offset < nread)
+		{
+			LLVFSFileBlock *block = new LLVFSFileBlock();
+    
+			block->deserialize(&buffer[buf_offset], (S32)buf_offset);
+    
+			// Do sanity check on this block.
+			// Note that this skips zero size blocks, which helps VFS
+			// to heal after some errors. JC
+			if (block->mLength > 0 &&
+				(U32)block->mLength <= data_size &&
+				block->mLocation < data_size &&
+				block->mSize > 0 &&
+				block->mSize <= block->mLength &&
+				block->mFileType >= LLAssetType::AT_NONE &&
+				block->mFileType < LLAssetType::AT_COUNT)
+			{
+				mFileBlocks.insert(fileblock_map::value_type(*block, block));
+				files_by_loc.push_back(block);
+			}
+			else
+			if (block->mLength && block->mSize > 0)
+			{
+				// this is corrupt, not empty
+				LL_WARNS("VFS") << "VFS corruption: " << block->mFileID << " (" << block->mFileType << ") at index " << block->mIndexLocation << " DS: " << data_size << LL_ENDL;
+				LL_WARNS("VFS") << "Length: " << block->mLength << "\tLocation: " << block->mLocation << "\tSize: " << block->mSize << LL_ENDL;
+				LL_WARNS("VFS") << "File has bad data - VFS removed" << LL_ENDL;
+
+				delete block;
+
+				unlockAndClose( mIndexFP );
+				mIndexFP = NULL;
+				LLFile::remove( mIndexFilename );
+
+				unlockAndClose( mDataFP );
+				mDataFP = NULL;
+				LLFile::remove( mDataFilename );
+
+				LL_WARNS("VFS") << "Deleted corrupt VFS files " 
+					<< mDataFilename 
+					<< " and "
+					<< mIndexFilename
+					<< LL_ENDL;
+
+				mValid = VFSVALID_BAD_CORRUPT;
+				return;
+			}
+			else
+			{
+				// this is a null or bad entry, skip it
+				mIndexHoles.push_back(buf_offset);
+    
+				delete block;
+			}
+    
+			buf_offset += LLVFSFileBlock::SERIAL_SIZE;
+		}
+
+		std::sort(
+			files_by_loc.begin(),
+			files_by_loc.end(),
+			LLVFSFileBlock::locationSortPredicate);
+
+		// There are 3 cases that have to be considered.
+		// 1. No blocks
+		// 2. One block.
+		// 3. Two or more blocks.
+		if (!files_by_loc.empty())
+		{
+			// cur walks through the list.
+			std::vector<LLVFSFileBlock*>::iterator cur = files_by_loc.begin();
+			std::vector<LLVFSFileBlock*>::iterator end = files_by_loc.end();
+			LLVFSFileBlock* last_file_block = *cur;
+			
+			// Check to see if there is an empty space before the first file.
+			if (last_file_block->mLocation > 0)
+			{
+				// If so, create a free block.
+				addFreeBlock(new LLVFSBlock(0, last_file_block->mLocation));
+			}
+
+			// Walk through the 2nd+ block.  If there is a free space
+			// between cur_file_block and last_file_block, add it to
+			// the free space collection.  This block will not need to
+			// run in the case there is only one entry in the VFS.
+			++cur;
+			while( cur != end )
+			{
+				LLVFSFileBlock* cur_file_block = *cur;
+
+				// Dupe check on the block
+				if (cur_file_block->mLocation == last_file_block->mLocation
+					&& cur_file_block->mLength == last_file_block->mLength)
+				{
+					LL_WARNS("VFS") << "VFS: removing duplicate entry"
+						<< " at " << cur_file_block->mLocation 
+						<< " length " << cur_file_block->mLength 
+						<< " size " << cur_file_block->mSize
+						<< " ID " << cur_file_block->mFileID 
+						<< " type " << cur_file_block->mFileType 
+						<< LL_ENDL;
+
+					// Duplicate entries.  Nuke them both for safety.
+					mFileBlocks.erase(*cur_file_block);	// remove ID/type entry
+					if (cur_file_block->mLength > 0)
+					{
+						// convert to hole
+						addFreeBlock(
+							new LLVFSBlock(
+								cur_file_block->mLocation,
+								cur_file_block->mLength));
+					}
+					lockData();						// needed for sync()
+					sync(cur_file_block, TRUE);		// remove first on disk
+					sync(last_file_block, TRUE);	// remove last on disk
+					unlockData();					// needed for sync()
+					last_file_block = cur_file_block;
+					++cur;
+					continue;
+				}
+
+				// Figure out where the last block ended.
+				S32 loc = last_file_block->mLocation+last_file_block->mLength;
+
+				// Figure out how much space there is between where
+				// the last block ended and this block begins.
+				S32 length = cur_file_block->mLocation - loc;
+    
+				// Check for more errors...  Seeing if the current
+				// entry and the last entry make sense together.
+				if (length < 0 || loc < 0 || (U32)loc > data_size)
+				{
+					// Invalid VFS
+					unlockAndClose( mIndexFP );
+					mIndexFP = NULL;
+					LLFile::remove( mIndexFilename );
+
+					unlockAndClose( mDataFP );
+					mDataFP = NULL;
+					LLFile::remove( mDataFilename );
+
+					LL_WARNS("VFS") << "VFS: overlapping entries"
+						<< " at " << cur_file_block->mLocation 
+						<< " length " << cur_file_block->mLength 
+						<< " ID " << cur_file_block->mFileID 
+						<< " type " << cur_file_block->mFileType 
+						<< LL_ENDL;
+
+					LL_WARNS("VFS") << "Deleted corrupt VFS files " 
+						<< mDataFilename 
+						<< " and "
+						<< mIndexFilename
+						<< LL_ENDL;
+
+					mValid = VFSVALID_BAD_CORRUPT;
+					return;
+				}
+
+				// we don't want to add empty blocks to the list...
+				if (length > 0)
+				{
+					addFreeBlock(new LLVFSBlock(loc, length));
+				}
+				last_file_block = cur_file_block;
+				++cur;
+			}
+    
+			// also note any empty space at the end
+			U32 loc = last_file_block->mLocation + last_file_block->mLength;
+			if (loc < data_size)
+			{
+				addFreeBlock(new LLVFSBlock(loc, data_size - loc));
+			}
+		}
+		else // There where no blocks in the file.
+		{
+			addFreeBlock(new LLVFSBlock(0, data_size));
+		}
+	}
+	else	// Pre-existing index file wasn't opened
+	{
+		if (mReadOnly)
+		{
+			LL_WARNS("VFS") << "Can't find " << mIndexFilename << " to open read-only VFS" << LL_ENDL;
+			mValid = VFSVALID_BAD_CANNOT_OPEN_READONLY;
+			return;
+		}
+    
+	
+		mIndexFP = openAndLock(mIndexFilename, "w+b", FALSE);
+		if (!mIndexFP)
+		{
+			LL_WARNS("VFS") << "Couldn't open an index file for the VFS, probably a sharing violation!" << LL_ENDL;
+
+			unlockAndClose( mDataFP );
+			mDataFP = NULL;
+			LLFile::remove( mDataFilename );
+			
+			mValid = VFSVALID_BAD_CANNOT_CREATE;
+			return;
+		}
+	
+		// no index file, start from scratch w/ 1GB allocation
+		LLVFSBlock *first_block = new LLVFSBlock(0, data_size ? data_size : 0x40000000);
+		addFreeBlock(first_block);
+	}
+
+	// Open marker file to look for bad shutdowns
+	if (!mReadOnly && mRemoveAfterCrash)
+	{
+		std::string marker = mDataFilename + ".open";
+		LLFILE* marker_fp = LLFile::fopen(marker, "w");	/* Flawfinder: ignore */
+		if (marker_fp)
+		{
+			fclose(marker_fp);
+			marker_fp = NULL;
+		}
+	}
+
+	LL_INFOS("VFS") << "Using VFS index file " << mIndexFilename << LL_ENDL;
+	LL_INFOS("VFS") << "Using VFS data file " << mDataFilename << LL_ENDL;
+
+	mValid = VFSVALID_OK;
+}
+    
+LLVFS::~LLVFS()
+{
+	if (mDataMutex->isLocked())
+	{
+		LL_ERRS("VFS") << "LLVFS destroyed with mutex locked" << LL_ENDL;
+	}
+	
+	unlockAndClose(mIndexFP);
+	mIndexFP = NULL;
+
+	fileblock_map::const_iterator it;
+	for (it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		delete (*it).second;
+	}
+	mFileBlocks.clear();
+	
+	mFreeBlocksByLength.clear();
+
+	for_each(mFreeBlocksByLocation.begin(), mFreeBlocksByLocation.end(), DeletePairedPointer());
+	mFreeBlocksByLocation.clear();
+    
+	unlockAndClose(mDataFP);
+	mDataFP = NULL;
+    
+	// Remove marker file
+	if (!mReadOnly && mRemoveAfterCrash)
+	{
+		std::string marker = mDataFilename + ".open";
+		LLFile::remove(marker);
+	}
+
+	delete mDataMutex;
+}
+
+
+// Use this function normally to create LLVFS files.  
+// Will append digits to the end of the filename with multiple re-trys
+// static 
+LLVFS * LLVFS::createLLVFS(const std::string& index_filename, 
+		const std::string& data_filename, 
+		const BOOL read_only, 
+		const U32 presize, 
+		const BOOL remove_after_crash)
+{
+	LLVFS * new_vfs = new LLVFS(index_filename, data_filename, read_only, presize, remove_after_crash);
+
+	if( !new_vfs->isValid() )
+	{	// First name failed, retry with new names
+		std::string retry_vfs_index_name;
+		std::string retry_vfs_data_name;
+		S32 count = 0;
+		while (!new_vfs->isValid() &&
+				count < 256)
+		{	// Append '.<number>' to end of filenames
+			retry_vfs_index_name = index_filename + llformat(".%u",count);
+			retry_vfs_data_name = data_filename + llformat(".%u", count);
+
+			delete new_vfs;	// Delete bad VFS and try again
+			new_vfs = new LLVFS(retry_vfs_index_name, retry_vfs_data_name, read_only, presize, remove_after_crash);
+
+			count++;
+		}
+	}
+
+	if( !new_vfs->isValid() )
+	{
+		delete new_vfs;		// Delete bad VFS
+		new_vfs = NULL;		// Total failure
+	}
+
+	return new_vfs;
+}
+
+
+
+void LLVFS::presizeDataFile(const U32 size)
+{
+	if (!mDataFP)
+	{
+		LL_ERRS() << "LLVFS::presizeDataFile() with no data file open" << LL_ENDL;
+		return;
+	}
+
+	// we're creating this file for the first time, size it
+	fseek(mDataFP, size-1, SEEK_SET);
+	S32 tmp = 0;
+	tmp = (S32)fwrite(&tmp, 1, 1, mDataFP);
+	// fflush(mDataFP);
+
+	// also remove any index, since this vfs is now blank
+	LLFile::remove(mIndexFilename);
+
+	if (tmp)
+	{
+		LL_INFOS() << "Pre-sized VFS data file to " << ftell(mDataFP) << " bytes" << LL_ENDL;
+	}
+	else
+	{
+		LL_WARNS() << "Failed to pre-size VFS data file" << LL_ENDL;
+	}
+}
+
+BOOL LLVFS::getExists(const LLUUID &file_id, const LLAssetType::EType file_type)
+{
+	LLVFSFileBlock *block = NULL;
+		
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+
+	lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		block = (*it).second;
+		block->mAccessTime = (U32)time(NULL);
+	}
+
+	BOOL res = (block && block->mLength > 0) ? TRUE : FALSE;
+	
+	unlockData();
+	
+	return res;
+}
+    
+S32	 LLVFS::getSize(const LLUUID &file_id, const LLAssetType::EType file_type)
+{
+	S32 size = 0;
+	
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+
+	}
+
+	lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+
+		block->mAccessTime = (U32)time(NULL);
+		size = block->mSize;
+	}
+
+	unlockData();
+	
+	return size;
+}
+    
+S32  LLVFS::getMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type)
+{
+	S32 size = 0;
+	
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+
+	lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+
+		block->mAccessTime = (U32)time(NULL);
+		size = block->mLength;
+	}
+
+	unlockData();
+
+	return size;
+}
+
+BOOL LLVFS::checkAvailable(S32 max_size)
+{
+	lockData();
+	
+	blocks_length_map_t::iterator iter = mFreeBlocksByLength.lower_bound(max_size); // first entry >= size
+	const BOOL res(iter == mFreeBlocksByLength.end() ? FALSE : TRUE);
+
+	unlockData();
+	
+	return res;
+}
+
+BOOL LLVFS::setMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type, S32 max_size)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	if (mReadOnly)
+	{
+		LL_ERRS() << "Attempt to write to read-only VFS" << LL_ENDL;
+	}
+	if (max_size <= 0)
+	{
+		LL_WARNS() << "VFS: Attempt to assign size " << max_size << " to vfile " << file_id << LL_ENDL;
+		return FALSE;
+	}
+
+	lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	LLVFSFileBlock *block = NULL;
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		block = (*it).second;
+	}
+    
+	// round all sizes upward to KB increments
+	// SJB: Need to not round for the new texture-pipeline code so we know the correct
+	//      max file size. Need to investigate the potential problems with this...
+	if (file_type != LLAssetType::AT_TEXTURE)
+	{
+		if (max_size & FILE_BLOCK_MASK)
+		{
+			max_size += FILE_BLOCK_MASK;
+			max_size &= ~FILE_BLOCK_MASK;
+		}
+    }
+	
+	if (block && block->mLength > 0)
+	{    
+		block->mAccessTime = (U32)time(NULL);
+    
+		if (max_size == block->mLength)
+		{
+			unlockData();
+			return TRUE;
+		}
+		else if (max_size < block->mLength)
+		{
+			// this file is shrinking
+			LLVFSBlock *free_block = new LLVFSBlock(block->mLocation + max_size, block->mLength - max_size);
+
+			addFreeBlock(free_block);
+    
+			block->mLength = max_size;
+    
+			if (block->mLength < block->mSize)
+			{
+				// JC: Was a warning, but Ian says it's bad.
+				LL_ERRS() << "Truncating virtual file " << file_id << " to " << block->mLength << " bytes" << LL_ENDL;
+				block->mSize = block->mLength;
+			}
+    
+			sync(block);
+			//mergeFreeBlocks();
+
+			unlockData();
+			return TRUE;
+		}
+		else if (max_size > block->mLength)
+		{
+			// this file is growing
+			// first check for an adjacent free block to grow into
+			S32 size_increase = max_size - block->mLength;
+
+			// Find the first free block with and addres > block->mLocation
+			LLVFSBlock *free_block;
+			blocks_location_map_t::iterator iter = mFreeBlocksByLocation.upper_bound(block->mLocation);
+			if (iter != mFreeBlocksByLocation.end())
+			{
+				free_block = iter->second;
+			
+				if (free_block->mLocation == block->mLocation + block->mLength &&
+					free_block->mLength >= size_increase)
+				{
+					// this free block is at the end of the file and is large enough
+
+					// Must call useFreeSpace before sync(), as sync()
+					// unlocks data structures.
+					useFreeSpace(free_block, size_increase);
+					block->mLength += size_increase;
+					sync(block);
+
+					unlockData();
+					return TRUE;
+				}
+			}
+			
+			// no adjecent free block, find one in the list
+			free_block = findFreeBlock(max_size, block);
+    
+			if (free_block)
+			{
+				// Save location where data is going, useFreeSpace will move free_block->mLocation;
+				U32 new_data_location = free_block->mLocation;
+
+				//mark the free block as used so it does not
+				//interfere with other operations such as addFreeBlock
+				useFreeSpace(free_block, max_size);		// useFreeSpace takes ownership (and may delete) free_block
+
+				if (block->mLength > 0)
+				{
+					// create a new free block where this file used to be
+					LLVFSBlock *new_free_block = new LLVFSBlock(block->mLocation, block->mLength);
+
+					addFreeBlock(new_free_block);
+					
+					if (block->mSize > 0)
+					{
+						// move the file into the new block
+						std::vector<U8> buffer(block->mSize);
+						fseek(mDataFP, block->mLocation, SEEK_SET);
+						if (fread(&buffer[0], block->mSize, 1, mDataFP) == 1)
+						{
+							fseek(mDataFP, new_data_location, SEEK_SET);
+							if (fwrite(&buffer[0], block->mSize, 1, mDataFP) != 1)
+							{
+								LL_WARNS() << "Short write" << LL_ENDL;
+							}
+						} else {
+							LL_WARNS() << "Short read" << LL_ENDL;
+						}
+					}
+				}
+    
+				block->mLocation = new_data_location;
+    
+				block->mLength = max_size;
+
+
+				sync(block);
+
+				unlockData();
+				return TRUE;
+			}
+			else
+			{
+				LL_WARNS() << "VFS: No space (" << max_size << ") to resize existing vfile " << file_id << LL_ENDL;
+				//dumpMap();
+				unlockData();
+				dumpStatistics();
+				return FALSE;
+			}
+		}
+	}
+	else
+	{
+		// find a free block in the list
+		LLVFSBlock *free_block = findFreeBlock(max_size);
+    
+		if (free_block)
+		{        
+			if (block)
+			{
+				block->mLocation = free_block->mLocation;
+				block->mLength = max_size;
+			}
+			else
+			{
+				// this file doesn't exist, create it
+				block = new LLVFSFileBlock(file_id, file_type, free_block->mLocation, max_size);
+				mFileBlocks.insert(fileblock_map::value_type(spec, block));
+			}
+
+			// Must call useFreeSpace before sync(), as sync()
+			// unlocks data structures.
+			useFreeSpace(free_block, max_size);
+			block->mAccessTime = (U32)time(NULL);
+
+			sync(block);
+		}
+		else
+		{
+			LL_WARNS() << "VFS: No space (" << max_size << ") for new virtual file " << file_id << LL_ENDL;
+			//dumpMap();
+			unlockData();
+			dumpStatistics();
+			return FALSE;
+		}
+	}
+	unlockData();
+	return TRUE;
+}
+
+
+// WARNING: HERE BE DRAGONS!
+// rename is the weirdest VFS op, because the file moves but the locks don't!
+void LLVFS::renameFile(const LLUUID &file_id, const LLAssetType::EType file_type,
+					   const LLUUID &new_id, const LLAssetType::EType &new_type)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	if (mReadOnly)
+	{
+		LL_ERRS() << "Attempt to write to read-only VFS" << LL_ENDL;
+	}
+
+	lockData();
+	
+	LLVFSFileSpecifier new_spec(new_id, new_type);
+	LLVFSFileSpecifier old_spec(file_id, file_type);
+	
+	fileblock_map::iterator it = mFileBlocks.find(old_spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *src_block = (*it).second;
+
+		// this will purge the data but leave the file block in place, w/ locks, if any
+		// WAS: removeFile(new_id, new_type); NOW uses removeFileBlock() to avoid mutex lock recursion
+		fileblock_map::iterator new_it = mFileBlocks.find(new_spec);
+		if (new_it != mFileBlocks.end())
+		{
+			LLVFSFileBlock *new_block = (*new_it).second;
+			removeFileBlock(new_block);
+		}
+		
+		// if there's something in the target location, remove it but inherit its locks
+		it = mFileBlocks.find(new_spec);
+		if (it != mFileBlocks.end())
+		{
+			LLVFSFileBlock *dest_block = (*it).second;
+
+			for (S32 i = 0; i < (S32)VFSLOCK_COUNT; i++)
+			{
+				if(dest_block->mLocks[i])
+				{
+					LL_ERRS() << "Renaming VFS block to a locked file." << LL_ENDL;
+				}
+				dest_block->mLocks[i] = src_block->mLocks[i];
+			}
+			
+			mFileBlocks.erase(new_spec);
+			delete dest_block;
+		}
+
+		src_block->mFileID = new_id;
+		src_block->mFileType = new_type;
+		src_block->mAccessTime = (U32)time(NULL);
+   
+		mFileBlocks.erase(old_spec);
+		mFileBlocks.insert(fileblock_map::value_type(new_spec, src_block));
+
+		sync(src_block);
+	}
+	else
+	{
+		LL_WARNS() << "VFS: Attempt to rename nonexistent vfile " << file_id << ":" << file_type << LL_ENDL;
+	}
+	unlockData();
+}
+
+// mDataMutex must be LOCKED before calling this
+void LLVFS::removeFileBlock(LLVFSFileBlock *fileblock)
+{
+	// convert this into an unsaved, dummy fileblock to preserve locks
+	// a more rubust solution would store the locks in a seperate data structure
+	sync(fileblock, TRUE);
+	
+	if (fileblock->mLength > 0)
+	{
+		// turn this file into an empty block
+		LLVFSBlock *free_block = new LLVFSBlock(fileblock->mLocation, fileblock->mLength);
+		
+		addFreeBlock(free_block);
+	}
+	
+	fileblock->mLocation = 0;
+	fileblock->mSize = 0;
+	fileblock->mLength = BLOCK_LENGTH_INVALID;
+	fileblock->mIndexLocation = -1;
+
+	//mergeFreeBlocks();
+}
+
+void LLVFS::removeFile(const LLUUID &file_id, const LLAssetType::EType file_type)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	if (mReadOnly)
+	{
+		LL_ERRS() << "Attempt to write to read-only VFS" << LL_ENDL;
+	}
+
+    lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+		removeFileBlock(block);
+	}
+	else
+	{
+		LL_WARNS() << "VFS: attempting to remove nonexistent file " << file_id << " type " << file_type << LL_ENDL;
+	}
+
+	unlockData();
+}
+    
+    
+S32 LLVFS::getData(const LLUUID &file_id, const LLAssetType::EType file_type, U8 *buffer, S32 location, S32 length)
+{
+	S32 bytesread = 0;
+	
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	llassert(location >= 0);
+	llassert(length >= 0);
+
+	BOOL do_read = FALSE;
+	
+    lockData();
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+
+		block->mAccessTime = (U32)time(NULL);
+    
+		if (location > block->mSize)
+		{
+			LL_WARNS() << "VFS: Attempt to read location " << location << " in file " << file_id << " of length " << block->mSize << LL_ENDL;
+		}
+		else
+		{
+			if (length > block->mSize - location)
+			{
+				length = block->mSize - location;
+			}
+			location += block->mLocation;
+			do_read = TRUE;
+		}
+	}
+
+	if (do_read)
+	{
+		fseek(mDataFP, location, SEEK_SET);
+		bytesread = (S32)fread(buffer, 1, length, mDataFP);
+	}
+	
+	unlockData();
+
+	return bytesread;
+}
+    
+S32 LLVFS::storeData(const LLUUID &file_id, const LLAssetType::EType file_type, const U8 *buffer, S32 location, S32 length)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	if (mReadOnly)
+	{
+		LL_ERRS() << "Attempt to write to read-only VFS" << LL_ENDL;
+	}
+    
+	llassert(length > 0);
+
+    lockData();
+    
+	LLVFSFileSpecifier spec(file_id, file_type);
+	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+
+		S32 in_loc = location;
+		if (location == -1)
+		{
+			location = block->mSize;
+		}
+		llassert(location >= 0);
+		
+		block->mAccessTime = (U32)time(NULL);
+    
+		if (block->mLength == BLOCK_LENGTH_INVALID)
+		{
+			// Block was removed, ignore write
+			LL_WARNS() << "VFS: Attempt to write to invalid block"
+					<< " in file " << file_id 
+					<< " location: " << in_loc
+					<< " bytes: " << length
+					<< LL_ENDL;
+			unlockData();
+			return length;
+		}
+		else if (location > block->mLength)
+		{
+			LL_WARNS() << "VFS: Attempt to write to location " << location 
+					<< " in file " << file_id 
+					<< " type " << S32(file_type)
+					<< " of size " << block->mSize
+					<< " block length " << block->mLength
+					<< LL_ENDL;
+			unlockData();
+			return length;
+		}
+		else
+		{
+			if (length > block->mLength - location )
+			{
+				LL_WARNS() << "VFS: Truncating write to virtual file " << file_id << " type " << S32(file_type) << LL_ENDL;
+				length = block->mLength - location;
+			}
+			U32 file_location = location + block->mLocation;
+			
+			fseek(mDataFP, file_location, SEEK_SET);
+			S32 write_len = (S32)fwrite(buffer, 1, length, mDataFP);
+			if (write_len != length)
+			{
+				LL_WARNS() << llformat("VFS Write Error: %d != %d",write_len,length) << LL_ENDL;
+			}
+			// fflush(mDataFP);
+			
+			if (location + length > block->mSize)
+			{
+				block->mSize = location + write_len;
+				sync(block);
+			}
+			unlockData();
+			
+			return write_len;
+		}
+	}
+	else
+	{
+		unlockData();
+		return 0;
+	}
+}
+ 
+void LLVFS::incLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock)
+{
+	lockData();
+
+	LLVFSFileSpecifier spec(file_id, file_type);
+	LLVFSFileBlock *block;
+	
+ 	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		block = (*it).second;
+	}
+	else
+	{
+		// Create a dummy block which isn't saved
+		block = new LLVFSFileBlock(file_id, file_type, 0, BLOCK_LENGTH_INVALID);
+    	block->mAccessTime = (U32)time(NULL);
+		mFileBlocks.insert(fileblock_map::value_type(spec, block));
+	}
+
+	block->mLocks[lock]++;
+	mLockCounts[lock]++;
+	
+	unlockData();
+}
+
+void LLVFS::decLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock)
+{
+	lockData();
+
+	LLVFSFileSpecifier spec(file_id, file_type);
+ 	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+
+		if (block->mLocks[lock] > 0)
+		{
+			block->mLocks[lock]--;
+		}
+		else
+		{
+			LL_WARNS() << "VFS: Decrementing zero-value lock " << lock << LL_ENDL;
+		}
+		mLockCounts[lock]--;
+	}
+
+	unlockData();
+}
+
+BOOL LLVFS::isLocked(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock)
+{
+	lockData();
+	
+	BOOL res = FALSE;
+	
+	LLVFSFileSpecifier spec(file_id, file_type);
+ 	fileblock_map::iterator it = mFileBlocks.find(spec);
+	if (it != mFileBlocks.end())
+	{
+		LLVFSFileBlock *block = (*it).second;
+		res = (block->mLocks[lock] > 0);
+	}
+
+	unlockData();
+
+	return res;
+}
+
+//============================================================================
+// protected
+//============================================================================
+
+void LLVFS::eraseBlockLength(LLVFSBlock *block)
+{
+	// find the corresponding map entry in the length map and erase it
+	S32 length = block->mLength;
+	blocks_length_map_t::iterator iter = mFreeBlocksByLength.lower_bound(length);
+	blocks_length_map_t::iterator end = mFreeBlocksByLength.end();
+	bool found_block = false;
+	while(iter != end)
+	{
+		LLVFSBlock *tblock = iter->second;
+		llassert(tblock->mLength == length); // there had -better- be an entry with our length!
+		if (tblock == block)
+		{
+			mFreeBlocksByLength.erase(iter);
+			found_block = true;
+			break;
+		}
+		++iter;
+	}
+	if(!found_block)
+	{
+		LL_ERRS() << "eraseBlock could not find block" << LL_ENDL;
+	}
+}
+
+
+// Remove block from both free lists (by location and by length).
+void LLVFS::eraseBlock(LLVFSBlock *block)
+{
+	eraseBlockLength(block);
+	// find the corresponding map entry in the location map and erase it	
+	U32 location = block->mLocation;
+	llverify(mFreeBlocksByLocation.erase(location) == 1); // we should only have one entry per location.
+}
+
+
+// Add the region specified by block location and length to the free lists.
+// Also incrementally defragment by merging with previous and next free blocks.
+void LLVFS::addFreeBlock(LLVFSBlock *block)
+{
+#if LL_DEBUG
+	size_t dbgcount = mFreeBlocksByLocation.count(block->mLocation);
+	if(dbgcount > 0)
+	{
+		LL_ERRS() << "addFreeBlock called with block already in list" << LL_ENDL;
+	}
+#endif
+
+	// Get a pointer to the next free block (by location).
+	blocks_location_map_t::iterator next_free_it = mFreeBlocksByLocation.lower_bound(block->mLocation);
+
+	// We can merge with previous if it ends at our requested location.
+	LLVFSBlock* prev_block = NULL;
+	bool merge_prev = false;
+	if (next_free_it != mFreeBlocksByLocation.begin())
+	{
+		blocks_location_map_t::iterator prev_free_it = next_free_it;
+		--prev_free_it;
+		prev_block = prev_free_it->second;
+		merge_prev = (prev_block->mLocation + prev_block->mLength == block->mLocation);
+	}
+
+	// We can merge with next if our block ends at the next block's location.
+	LLVFSBlock* next_block = NULL;
+	bool merge_next = false;
+	if (next_free_it != mFreeBlocksByLocation.end())
+	{
+		next_block = next_free_it->second;
+		merge_next = (block->mLocation + block->mLength == next_block->mLocation);
+	}
+
+	if (merge_prev && merge_next)
+	{
+		// LL_INFOS() << "VFS merge BOTH" << LL_ENDL;
+		// Previous block is changing length (a lot), so only need to update length map.
+		// Next block is going away completely. JC
+		eraseBlockLength(prev_block);
+		eraseBlock(next_block);
+		prev_block->mLength += block->mLength + next_block->mLength;
+		mFreeBlocksByLength.insert(blocks_length_map_t::value_type(prev_block->mLength, prev_block));
+		delete block;
+		block = NULL;
+		delete next_block;
+		next_block = NULL;
+	}
+	else if (merge_prev)
+	{
+		// LL_INFOS() << "VFS merge previous" << LL_ENDL;
+		// Previous block is maintaining location, only changing length,
+		// therefore only need to update the length map. JC
+		eraseBlockLength(prev_block);
+		prev_block->mLength += block->mLength;
+		mFreeBlocksByLength.insert(blocks_length_map_t::value_type(prev_block->mLength, prev_block)); // multimap insert
+		delete block;
+		block = NULL;
+	}
+	else if (merge_next)
+	{
+		// LL_INFOS() << "VFS merge next" << LL_ENDL;
+		// Next block is changing both location and length,
+		// so both free lists must update. JC
+		eraseBlock(next_block);
+		next_block->mLocation = block->mLocation;
+		next_block->mLength += block->mLength;
+		// Don't hint here, next_free_it iterator may be invalid.
+		mFreeBlocksByLocation.insert(blocks_location_map_t::value_type(next_block->mLocation, next_block)); // multimap insert
+		mFreeBlocksByLength.insert(blocks_length_map_t::value_type(next_block->mLength, next_block)); // multimap insert			
+		delete block;
+		block = NULL;
+	}
+	else
+	{
+		// Can't merge with other free blocks.
+		// Hint that insert should go near next_free_it.
+ 		mFreeBlocksByLocation.insert(next_free_it, blocks_location_map_t::value_type(block->mLocation, block)); // multimap insert
+ 		mFreeBlocksByLength.insert(blocks_length_map_t::value_type(block->mLength, block)); // multimap insert
+	}
+}
+
+// Superceeded by new addFreeBlock which does incremental free space merging.
+// Incremental is faster overall.
+//void LLVFS::mergeFreeBlocks()
+//{
+// 	if (!isValid())
+// 	{
+// 		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+// 	}
+// 	// TODO: could we optimize this with hints from the calling code?
+// 	blocks_location_map_t::iterator iter = mFreeBlocksByLocation.begin();	
+// 	blocks_location_map_t::iterator end = mFreeBlocksByLocation.end();	
+// 	LLVFSBlock *first_block = iter->second;
+// 	while(iter != end)
+// 	{
+// 		blocks_location_map_t::iterator first_iter = iter; // save for if we do a merge
+// 		if (++iter == end)
+// 			break;
+// 		LLVFSBlock *second_block = iter->second;
+// 		if (first_block->mLocation + first_block->mLength == second_block->mLocation)
+// 		{
+// 			// remove the first block from the length map
+// 			eraseBlockLength(first_block);
+// 			// merge first_block with second_block, since they're adjacent
+// 			first_block->mLength += second_block->mLength;
+// 			// add the first block to the length map (with the new size)
+// 			mFreeBlocksByLength.insert(blocks_length_map_t::value_type(first_block->mLength, first_block)); // multimap insert
+//
+// 			// erase and delete the second block
+// 			eraseBlock(second_block);
+// 			delete second_block;
+//
+// 			// reset iterator
+// 			iter = first_iter; // haven't changed first_block, so corresponding iterator is still valid
+// 			end = mFreeBlocksByLocation.end();
+// 		}
+// 		first_block = second_block;
+// 	}
+//}
+	
+// length bytes from free_block are going to be used (so they are no longer free)
+void LLVFS::useFreeSpace(LLVFSBlock *free_block, S32 length)
+{
+	if (free_block->mLength == length)
+	{
+		eraseBlock(free_block);
+		delete free_block;
+	}
+	else
+	{
+		eraseBlock(free_block);
+  		
+		free_block->mLocation += length;
+		free_block->mLength -= length;
+
+		addFreeBlock(free_block);
+	}
+}
+
+// NOTE! mDataMutex must be LOCKED before calling this
+// sync this index entry out to the index file
+// we need to do this constantly to avoid corruption on viewer crash
+void LLVFS::sync(LLVFSFileBlock *block, BOOL remove)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	if (mReadOnly)
+	{
+		LL_WARNS() << "Attempt to sync read-only VFS" << LL_ENDL;
+		return;
+	}
+	if (block->mLength == BLOCK_LENGTH_INVALID)
+	{
+		// This is a dummy file, don't save
+		return;
+	}
+	if (block->mLength == 0)
+	{
+		LL_ERRS() << "VFS syncing zero-length block" << LL_ENDL;
+	}
+
+    BOOL set_index_to_end = FALSE;
+	long seek_pos = block->mIndexLocation;
+		
+	if (-1 == seek_pos)
+	{
+		if (!mIndexHoles.empty())
+		{
+			seek_pos = mIndexHoles.front();
+			mIndexHoles.pop_front();
+		}
+		else
+		{
+			set_index_to_end = TRUE;
+		}
+	}
+
+    if (set_index_to_end)
+	{
+		// Need fseek/ftell to update the seek_pos and hence data
+		// structures, so can't unlockData() before this.
+		fseek(mIndexFP, 0, SEEK_END);
+		seek_pos = ftell(mIndexFP);
+	}
+	    
+	block->mIndexLocation = seek_pos;
+	if (remove)
+	{
+		mIndexHoles.push_back(seek_pos);
+	}
+
+	U8 buffer[LLVFSFileBlock::SERIAL_SIZE];
+	if (remove)
+	{
+		memset(buffer, 0, LLVFSFileBlock::SERIAL_SIZE);
+	}
+	else
+	{
+		block->serialize(buffer);
+	}
+
+	// If set_index_to_end, file pointer is already at seek_pos
+	// and we don't need to do anything.  Only seek if not at end.
+	if (!set_index_to_end)
+	{
+		fseek(mIndexFP, seek_pos, SEEK_SET);
+	}
+
+	if (fwrite(buffer, LLVFSFileBlock::SERIAL_SIZE, 1, mIndexFP) != 1)
+	{
+		LL_WARNS() << "Short write" << LL_ENDL;
+	}
+
+	// *NOTE:  Why was this commented out?
+	// fflush(mIndexFP);
+	
+	return;
+}
+
+// mDataMutex must be LOCKED before calling this
+// Can initiate LRU-based file removal to make space.
+// The immune file block will not be removed.
+LLVFSBlock *LLVFS::findFreeBlock(S32 size, LLVFSFileBlock *immune)
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+
+	LLVFSBlock *block = NULL;
+	BOOL have_lru_list = FALSE;
+	
+	typedef std::set<LLVFSFileBlock*, LLVFSFileBlock_less> lru_set;
+	lru_set lru_list;
+    
+	LLTimer timer;
+
+	while (! block)
+	{
+		// look for a suitable free block
+		blocks_length_map_t::iterator iter = mFreeBlocksByLength.lower_bound(size); // first entry >= size
+		if (iter != mFreeBlocksByLength.end())
+			block = iter->second;
+    	
+		// no large enough free blocks, time to clean out some junk
+		if (! block)
+		{
+			// create a list of files sorted by usage time
+			// this is far faster than sorting a linked list
+			if (! have_lru_list)
+			{
+				for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+				{
+					LLVFSFileBlock *tmp = (*it).second;
+
+					if (tmp != immune &&
+						tmp->mLength > 0 &&
+						! tmp->mLocks[VFSLOCK_READ] &&
+						! tmp->mLocks[VFSLOCK_APPEND] &&
+						! tmp->mLocks[VFSLOCK_OPEN])
+					{
+						lru_list.insert(tmp);
+					}
+				}
+				
+				have_lru_list = TRUE;
+			}
+
+			if (lru_list.size() == 0)
+			{
+				// No more files to delete, and still not enough room!
+				LL_WARNS() << "VFS: Can't make " << size << " bytes of free space in VFS, giving up" << LL_ENDL;
+				break;
+			}
+
+			// is the oldest file big enough?  (Should be about half the time)
+			lru_set::iterator it = lru_list.begin();
+			LLVFSFileBlock *file_block = *it;
+			if (file_block->mLength >= size && file_block != immune)
+			{
+				// ditch this file and look again for a free block - should find it
+				// TODO: it'll be faster just to assign the free block and break
+				LL_INFOS() << "LRU: Removing " << file_block->mFileID << ":" << file_block->mFileType << LL_ENDL;
+				lru_list.erase(it);
+				removeFileBlock(file_block);
+				file_block = NULL;
+				continue;
+			}
+
+			
+			LL_INFOS() << "VFS: LRU: Aggressive: " << (S32)lru_list.size() << " files remain" << LL_ENDL;
+			dumpLockCounts();
+			
+			// Now it's time to aggressively make more space
+			// Delete the oldest 5MB of the vfs or enough to hold the file, which ever is larger
+			// This may yield too much free space, but we'll use it up soon enough
+			U32 cleanup_target = (size > VFS_CLEANUP_SIZE) ? size : VFS_CLEANUP_SIZE;
+			U32 cleaned_up = 0;
+		   	for (it = lru_list.begin();
+				 it != lru_list.end() && cleaned_up < cleanup_target;
+				 )
+			{
+				file_block = *it;
+				
+				// TODO: it would be great to be able to batch all these sync() calls
+				// LL_INFOS() << "LRU2: Removing " << file_block->mFileID << ":" << file_block->mFileType << " last accessed" << file_block->mAccessTime << LL_ENDL;
+
+				cleaned_up += file_block->mLength;
+				lru_list.erase(it++);
+				removeFileBlock(file_block);
+				file_block = NULL;
+			}
+			//mergeFreeBlocks();
+		}
+	}
+    
+	F32 time = timer.getElapsedTimeF32();
+	if (time > 0.5f)
+	{
+		LL_WARNS() << "VFS: Spent " << time << " seconds in findFreeBlock!" << LL_ENDL;
+	}
+
+	return block;
+}
+
+//============================================================================
+// public
+//============================================================================
+
+void LLVFS::pokeFiles()
+{
+	if (!isValid())
+	{
+		LL_ERRS() << "Attempting to use invalid VFS!" << LL_ENDL;
+	}
+	U32 word;
+	
+	// only write data if we actually read 4 bytes
+	// otherwise we're writing garbage and screwing up the file
+	fseek(mDataFP, 0, SEEK_SET);
+	if (fread(&word, sizeof(word), 1, mDataFP) == 1)
+	{
+		fseek(mDataFP, 0, SEEK_SET);
+		if (fwrite(&word, sizeof(word), 1, mDataFP) != 1)
+		{
+			LL_WARNS() << "Could not write to data file" << LL_ENDL;
+		}
+		fflush(mDataFP);
+	}
+
+	fseek(mIndexFP, 0, SEEK_SET);
+	if (fread(&word, sizeof(word), 1, mIndexFP) == 1)
+	{
+		fseek(mIndexFP, 0, SEEK_SET);
+		if (fwrite(&word, sizeof(word), 1, mIndexFP) != 1)
+		{
+			LL_WARNS() << "Could not write to index file" << LL_ENDL;
+		}
+		fflush(mIndexFP);
+	}
+}
+
+    
+void LLVFS::dumpMap()
+{
+	LL_INFOS() << "Files:" << LL_ENDL;
+	for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		LLVFSFileBlock *file_block = (*it).second;
+		LL_INFOS() << "Location: " << file_block->mLocation << "\tLength: " << file_block->mLength << "\t" << file_block->mFileID << "\t" << file_block->mFileType << LL_ENDL;
+	}
+    
+	LL_INFOS() << "Free Blocks:" << LL_ENDL;
+	for (blocks_location_map_t::iterator iter = mFreeBlocksByLocation.begin(),
+			 end = mFreeBlocksByLocation.end();
+		 iter != end; iter++)
+	{
+		LLVFSBlock *free_block = iter->second;
+		LL_INFOS() << "Location: " << free_block->mLocation << "\tLength: " << free_block->mLength << LL_ENDL;
+	}
+}
+    
+// verify that the index file contents match the in-memory file structure
+// Very slow, do not call routinely. JC
+void LLVFS::audit()
+{
+	// Lock the mutex through this whole function.
+	LLMutexLock lock_data(mDataMutex);
+	
+	fflush(mIndexFP);
+
+	fseek(mIndexFP, 0, SEEK_END);
+	size_t index_size = ftell(mIndexFP);
+	fseek(mIndexFP, 0, SEEK_SET);
+    
+	BOOL vfs_corrupt = FALSE;
+	
+	// since we take the address of element 0, we need to have at least one element.
+	std::vector<U8> buffer(llmax<size_t>(index_size,1U));
+
+	if (fread(&buffer[0], 1, index_size, mIndexFP) != index_size)
+	{
+		LL_WARNS() << "Index truncated" << LL_ENDL;
+		vfs_corrupt = TRUE;
+	}
+    
+	size_t buf_offset = 0;
+    
+	std::map<LLVFSFileSpecifier, LLVFSFileBlock*>	found_files;
+	U32 cur_time = (U32)time(NULL);
+
+	std::vector<LLVFSFileBlock*> audit_blocks;
+	while (!vfs_corrupt && buf_offset < index_size)
+	{
+		LLVFSFileBlock *block = new LLVFSFileBlock();
+		audit_blocks.push_back(block);
+		
+		block->deserialize(&buffer[buf_offset], (S32)buf_offset);
+		buf_offset += block->SERIAL_SIZE;
+    
+		// do sanity check on this block
+		if (block->mLength >= 0 &&
+			block->mSize >= 0 &&
+			block->mSize <= block->mLength &&
+			block->mFileType >= LLAssetType::AT_NONE &&
+			block->mFileType < LLAssetType::AT_COUNT &&
+			block->mAccessTime <= cur_time &&
+			block->mFileID != LLUUID::null)
+		{
+			if (mFileBlocks.find(*block) == mFileBlocks.end())
+			{
+				LL_WARNS() << "VFile " << block->mFileID << ":" << block->mFileType << " on disk, not in memory, loc " << block->mIndexLocation << LL_ENDL;
+			}
+			else if (found_files.find(*block) != found_files.end())
+			{
+				std::map<LLVFSFileSpecifier, LLVFSFileBlock*>::iterator it;
+				it = found_files.find(*block);
+				LLVFSFileBlock* dupe = it->second;
+				// try to keep data from being lost
+				unlockAndClose(mIndexFP);
+				mIndexFP = NULL;
+				unlockAndClose(mDataFP);
+				mDataFP = NULL;
+				LL_WARNS() << "VFS: Original block index " << block->mIndexLocation
+					<< " location " << block->mLocation 
+					<< " length " << block->mLength 
+					<< " size " << block->mSize 
+					<< " id " << block->mFileID
+					<< " type " << block->mFileType
+					<< LL_ENDL;
+				LL_WARNS() << "VFS: Duplicate block index " << dupe->mIndexLocation
+					<< " location " << dupe->mLocation 
+					<< " length " << dupe->mLength 
+					<< " size " << dupe->mSize 
+					<< " id " << dupe->mFileID
+					<< " type " << dupe->mFileType
+					<< LL_ENDL;
+				LL_WARNS() << "VFS: Index size " << index_size << LL_ENDL;
+				LL_WARNS() << "VFS: INDEX CORRUPT" << LL_ENDL;
+				vfs_corrupt = TRUE;
+				break;
+			}
+			else
+			{
+				found_files[*block] = block;
+			}
+		}
+		else
+		{
+			if (block->mLength)
+			{
+				LL_WARNS() << "VFile " << block->mFileID << ":" << block->mFileType << " corrupt on disk" << LL_ENDL;
+			}
+			// else this is just a hole
+		}
+	}
+    
+	if (!vfs_corrupt)
+	{
+		for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+		{
+			LLVFSFileBlock* block = (*it).second;
+
+			if (block->mSize > 0)
+			{
+				if (! found_files.count(*block))
+				{
+					LL_WARNS() << "VFile " << block->mFileID << ":" << block->mFileType << " in memory, not on disk, loc " << block->mIndexLocation<< LL_ENDL;
+					fseek(mIndexFP, block->mIndexLocation, SEEK_SET);
+					U8 buf[LLVFSFileBlock::SERIAL_SIZE];
+					if (fread(buf, LLVFSFileBlock::SERIAL_SIZE, 1, mIndexFP) != 1)
+					{
+						LL_WARNS() << "VFile " << block->mFileID
+								<< " gave short read" << LL_ENDL;
+					}
+    			
+					LLVFSFileBlock disk_block;
+					disk_block.deserialize(buf, block->mIndexLocation);
+				
+					LL_WARNS() << "Instead found " << disk_block.mFileID << ":" << block->mFileType << LL_ENDL;
+				}
+				else
+				{
+					block = found_files.find(*block)->second;
+					found_files.erase(*block);
+				}
+			}
+		}
+    
+		for (std::map<LLVFSFileSpecifier, LLVFSFileBlock*>::iterator iter = found_files.begin();
+			 iter != found_files.end(); iter++)
+		{
+			LLVFSFileBlock* block = iter->second;
+			LL_WARNS() << "VFile " << block->mFileID << ":" << block->mFileType << " szie:" << block->mSize << " leftover" << LL_ENDL;
+		}
+    
+		LL_INFOS() << "VFS: audit OK" << LL_ENDL;
+		// mutex released by LLMutexLock() destructor.
+	}
+
+	for_each(audit_blocks.begin(), audit_blocks.end(), DeletePointer());
+	audit_blocks.clear();
+}
+    
+    
+// quick check for uninitialized blocks
+// Slow, do not call in release.
+void LLVFS::checkMem()
+{
+	lockData();
+	
+	for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		LLVFSFileBlock *block = (*it).second;
+		llassert(block->mFileType >= LLAssetType::AT_NONE &&
+				 block->mFileType < LLAssetType::AT_COUNT &&
+				 block->mFileID != LLUUID::null);
+    
+		for (std::deque<S32>::iterator iter = mIndexHoles.begin();
+			 iter != mIndexHoles.end(); ++iter)
+		{
+			S32 index_loc = *iter;
+			if (index_loc == block->mIndexLocation)
+			{
+				LL_WARNS() << "VFile block " << block->mFileID << ":" << block->mFileType << " is marked as a hole" << LL_ENDL;
+			}
+		}
+	}
+    
+	LL_INFOS() << "VFS: mem check OK" << LL_ENDL;
+
+	unlockData();
+}
+
+void LLVFS::dumpLockCounts()
+{
+	S32 i;
+	for (i = 0; i < VFSLOCK_COUNT; i++)
+	{
+		LL_INFOS() << "LockType: " << i << ": " << mLockCounts[i] << LL_ENDL;
+	}
+}
+
+void LLVFS::dumpStatistics()
+{
+	lockData();
+	
+	// Investigate file blocks.
+	std::map<S32, S32> size_counts;
+	std::map<U32, S32> location_counts;
+	std::map<LLAssetType::EType, std::pair<S32,S32> > filetype_counts;
+
+	S32 max_file_size = 0;
+	S32 total_file_size = 0;
+	S32 invalid_file_count = 0;
+	for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		LLVFSFileBlock *file_block = (*it).second;
+		if (file_block->mLength == BLOCK_LENGTH_INVALID)
+		{
+			invalid_file_count++;
+		}
+		else if (file_block->mLength <= 0)
+		{
+			LL_INFOS() << "Bad file block at: " << file_block->mLocation << "\tLength: " << file_block->mLength << "\t" << file_block->mFileID << "\t" << file_block->mFileType << LL_ENDL;
+			size_counts[file_block->mLength]++;
+			location_counts[file_block->mLocation]++;
+		}
+		else
+		{
+			total_file_size += file_block->mLength;
+		}
+
+		if (file_block->mLength > max_file_size)
+		{
+			max_file_size = file_block->mLength;
+		}
+
+		filetype_counts[file_block->mFileType].first++;
+		filetype_counts[file_block->mFileType].second += file_block->mLength;
+	}
+    
+	for (std::map<S32,S32>::iterator it = size_counts.begin(); it != size_counts.end(); ++it)
+	{
+		S32 size = it->first;
+		S32 size_count = it->second;
+		LL_INFOS() << "Bad files size " << size << " count " << size_count << LL_ENDL;
+	}
+	for (std::map<U32,S32>::iterator it = location_counts.begin(); it != location_counts.end(); ++it)
+	{
+		U32 location = it->first;
+		S32 location_count = it->second;
+		LL_INFOS() << "Bad files location " << location << " count " << location_count << LL_ENDL;
+	}
+
+	// Investigate free list.
+	S32 max_free_size = 0;
+	S32 total_free_size = 0;
+	std::map<S32, S32> free_length_counts;
+	for (blocks_location_map_t::iterator iter = mFreeBlocksByLocation.begin(),
+			 end = mFreeBlocksByLocation.end();
+		 iter != end; iter++)
+	{
+		LLVFSBlock *free_block = iter->second;
+		if (free_block->mLength <= 0)
+		{
+			LL_INFOS() << "Bad free block at: " << free_block->mLocation << "\tLength: " << free_block->mLength << LL_ENDL;
+		}
+		else
+		{
+			LL_INFOS() << "Block: " << free_block->mLocation
+					<< "\tLength: " << free_block->mLength
+					<< "\tEnd: " << free_block->mLocation + free_block->mLength
+					<< LL_ENDL;
+			total_free_size += free_block->mLength;
+		}
+
+		if (free_block->mLength > max_free_size)
+		{
+			max_free_size = free_block->mLength;
+		}
+
+		free_length_counts[free_block->mLength]++;
+	}
+
+	// Dump histogram of free block sizes
+	for (std::map<S32,S32>::iterator it = free_length_counts.begin(); it != free_length_counts.end(); ++it)
+	{
+		LL_INFOS() << "Free length " << it->first << " count " << it->second << LL_ENDL;
+	}
+
+	LL_INFOS() << "Invalid blocks: " << invalid_file_count << LL_ENDL;
+	LL_INFOS() << "File blocks:    " << mFileBlocks.size() << LL_ENDL;
+
+	S32 length_list_count = (S32)mFreeBlocksByLength.size();
+	S32 location_list_count = (S32)mFreeBlocksByLocation.size();
+	if (length_list_count == location_list_count)
+	{
+		LL_INFOS() << "Free list lengths match, free blocks: " << location_list_count << LL_ENDL;
+	}
+	else
+	{
+		LL_WARNS() << "Free list lengths do not match!" << LL_ENDL;
+		LL_WARNS() << "By length: " << length_list_count << LL_ENDL;
+		LL_WARNS() << "By location: " << location_list_count << LL_ENDL;
+	}
+	LL_INFOS() << "Max file: " << max_file_size/1024 << "K" << LL_ENDL;
+	LL_INFOS() << "Max free: " << max_free_size/1024 << "K" << LL_ENDL;
+	LL_INFOS() << "Total file size: " << total_file_size/1024 << "K" << LL_ENDL;
+	LL_INFOS() << "Total free size: " << total_free_size/1024 << "K" << LL_ENDL;
+	LL_INFOS() << "Sum: " << (total_file_size + total_free_size) << " bytes" << LL_ENDL;
+	LL_INFOS() << llformat("%.0f%% full",((F32)(total_file_size)/(F32)(total_file_size+total_free_size))*100.f) << LL_ENDL;
+
+	LL_INFOS() << " " << LL_ENDL;
+	for (std::map<LLAssetType::EType, std::pair<S32,S32> >::iterator iter = filetype_counts.begin();
+		 iter != filetype_counts.end(); ++iter)
+	{
+		LL_INFOS() << "Type: " << LLAssetType::getDesc(iter->first)
+				<< " Count: " << iter->second.first
+				<< " Bytes: " << (iter->second.second>>20) << " MB" << LL_ENDL;
+	}
+	
+	// Look for potential merges 
+	{
+ 		blocks_location_map_t::iterator iter = mFreeBlocksByLocation.begin();	
+ 		blocks_location_map_t::iterator end = mFreeBlocksByLocation.end();	
+ 		LLVFSBlock *first_block = iter->second;
+ 		while(iter != end)
+ 		{
+ 			if (++iter == end)
+ 				break;
+ 			LLVFSBlock *second_block = iter->second;
+ 			if (first_block->mLocation + first_block->mLength == second_block->mLocation)
+ 			{
+				LL_INFOS() << "Potential merge at " << first_block->mLocation << LL_ENDL;
+ 			}
+ 			first_block = second_block;
+ 		}
+	}
+	unlockData();
+}
+
+// Debug Only!
+std::string get_extension(LLAssetType::EType type)
+{
+	std::string extension;
+	switch(type)
+	{
+	case LLAssetType::AT_TEXTURE:
+		extension = ".jp2";	// formerly ".j2c"
+		break;
+	case LLAssetType::AT_SOUND:
+		extension = ".ogg";
+		break;
+	case LLAssetType::AT_SOUND_WAV:
+		extension = ".wav";
+		break;
+	case LLAssetType::AT_TEXTURE_TGA:
+		extension = ".tga";
+		break;
+	case LLAssetType::AT_ANIMATION:
+		extension = ".lla";
+		break;
+	case LLAssetType::AT_MESH:
+		extension = ".slm";
+		break;
+	default:
+		// Just use the asset server filename extension in most cases
+		extension += ".";
+		extension += LLAssetType::lookup(type);
+		break;
+	}
+	return extension;
+}
+
+void LLVFS::listFiles()
+{
+	lockData();
+	
+	for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		LLVFSFileSpecifier file_spec = it->first;
+		LLVFSFileBlock *file_block = it->second;
+		S32 length = file_block->mLength;
+		S32 size = file_block->mSize;
+		if (length != BLOCK_LENGTH_INVALID && size > 0)
+		{
+			LLUUID id = file_spec.mFileID;
+			std::string extension = get_extension(file_spec.mFileType);
+			LL_INFOS() << " File: " << id
+					<< " Type: " << LLAssetType::getDesc(file_spec.mFileType)
+					<< " Size: " << size
+					<< LL_ENDL;
+		}
+	}
+	
+	unlockData();
+}
+
+#include "llapr.h"
+void LLVFS::dumpFiles()
+{
+	lockData();
+	
+	S32 files_extracted = 0;
+	for (fileblock_map::iterator it = mFileBlocks.begin(); it != mFileBlocks.end(); ++it)
+	{
+		LLVFSFileSpecifier file_spec = it->first;
+		LLVFSFileBlock *file_block = it->second;
+		S32 length = file_block->mLength;
+		S32 size = file_block->mSize;
+		if (length != BLOCK_LENGTH_INVALID && size > 0)
+		{
+			LLUUID id = file_spec.mFileID;
+			LLAssetType::EType type = file_spec.mFileType;
+			std::vector<U8> buffer(size);
+
+			unlockData();
+			getData(id, type, &buffer[0], 0, size);
+			lockData();
+			
+			std::string extension = get_extension(type);
+			std::string filename = id.asString() + extension;
+			LL_INFOS() << " Writing " << filename << LL_ENDL;
+			
+			LLAPRFile outfile;
+			outfile.open(filename, LL_APR_WB);
+			outfile.write(&buffer[0], size);
+			outfile.close();
+
+			files_extracted++;
+		}
+	}
+	
+	unlockData();
+
+	LL_INFOS() << "Extracted " << files_extracted << " files out of " << mFileBlocks.size() << LL_ENDL;
+}
+
+time_t LLVFS::creationTime()
+{
+    llstat data_file_stat;
+    int errors = LLFile::stat(mDataFilename, &data_file_stat);
+    if (0 == errors)
+    {
+        time_t creation_time = data_file_stat.st_ctime;
+#if LL_DARWIN
+        creation_time = data_file_stat.st_birthtime;
+#endif
+        return creation_time;
+    }
+    return 0;
+}
+
+//============================================================================
+// protected
+//============================================================================
+
+// static
+LLFILE *LLVFS::openAndLock(const std::string& filename, const char* mode, BOOL read_lock)
+{
+#if LL_WINDOWS
+    	
+	return LLFile::_fsopen(filename, mode, (read_lock ? _SH_DENYWR : _SH_DENYRW));
+    	
+#else
+
+	LLFILE *fp;
+	int fd;
+	
+	// first test the lock in a non-destructive way
+#if LL_SOLARIS
+        struct flock fl;
+        fl.l_whence = SEEK_SET;
+        fl.l_start = 0;
+        fl.l_len = 1;
+#else // !LL_SOLARIS
+	if (strchr(mode, 'w') != NULL)
+	{
+		fp = LLFile::fopen(filename, "rb");	/* Flawfinder: ignore */
+		if (fp)
+		{
+			fd = fileno(fp);
+			if (flock(fd, (read_lock ? LOCK_SH : LOCK_EX) | LOCK_NB) == -1)
+			{
+				fclose(fp);
+				return NULL;
+			}
+		  
+			fclose(fp);
+		}
+	}
+#endif // !LL_SOLARIS
+
+	// now actually open the file for use
+	fp = LLFile::fopen(filename, mode);	/* Flawfinder: ignore */
+	if (fp)
+	{
+		fd = fileno(fp);
+#if LL_SOLARIS
+                fl.l_type = read_lock ? F_RDLCK : F_WRLCK;
+                if (fcntl(fd, F_SETLK, &fl) == -1)
+#else
+		if (flock(fd, (read_lock ? LOCK_SH : LOCK_EX) | LOCK_NB) == -1)
+#endif
+		{
+			fclose(fp);
+			fp = NULL;
+		}
+	}
+
+	return fp;
+    	
+#endif
+}
+    
+// static
+void LLVFS::unlockAndClose(LLFILE *fp)
+{
+	if (fp)
+	{
+	// IW: we don't actually want to unlock on linux
+	// this is because a forked process can kill the parent's lock
+	// with an explicit unlock
+	// however, fclose() will implicitly remove the lock
+	// but only once both parent and child have closed the file
+    /*	
+	  #if !LL_WINDOWS
+	  int fd = fileno(fp);
+	  flock(fd, LOCK_UN);
+	  #endif
+    */
+#if LL_SOLARIS
+	        struct flock fl;
+		fl.l_whence = SEEK_SET;
+		fl.l_start = 0;
+		fl.l_len = 1;
+		fl.l_type = F_UNLCK;
+		fcntl(fileno(fp), F_SETLK, &fl);
+#endif
+		fclose(fp);
+	}
+}
diff --git a/indra/llvfs/llvfs.h b/indra/llvfs/llvfs.h
new file mode 100644
index 0000000000..42feafe20b
--- /dev/null
+++ b/indra/llvfs/llvfs.h
@@ -0,0 +1,183 @@
+/** 
+ * @file llvfs.h
+ * @brief Definition of virtual file system
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLVFS_H
+#define LL_LLVFS_H
+
+#include <deque>
+#include "lluuid.h"
+#include "llassettype.h"
+#include "llthread.h"
+#include "llmutex.h"
+
+enum EVFSValid 
+{
+	VFSVALID_UNKNOWN = 0, 
+	VFSVALID_OK = 1,
+	VFSVALID_BAD_CORRUPT = 2,
+	VFSVALID_BAD_CANNOT_OPEN_READONLY = 3,
+	VFSVALID_BAD_CANNOT_CREATE = 4
+};
+
+// Lock types for open vfiles, pending async reads, and pending async appends
+// (There are no async normal writes, currently)
+enum EVFSLock
+{
+	VFSLOCK_OPEN = 0,
+	VFSLOCK_READ = 1,
+	VFSLOCK_APPEND = 2,
+
+	VFSLOCK_COUNT = 3
+};
+
+// internal classes
+class LLVFSBlock;
+class LLVFSFileBlock;
+class LLVFSFileSpecifier
+{
+public:
+	LLVFSFileSpecifier();
+	LLVFSFileSpecifier(const LLUUID &file_id, const LLAssetType::EType file_type);
+	bool operator<(const LLVFSFileSpecifier &rhs) const;
+	bool operator==(const LLVFSFileSpecifier &rhs) const;
+
+public:
+	LLUUID mFileID;
+	LLAssetType::EType mFileType;
+};
+
+class LLVFS
+{
+private:
+	// Use createLLVFS() to open a VFS file
+	// Pass 0 to not presize
+	LLVFS(const std::string& index_filename, 
+			const std::string& data_filename, 
+			const BOOL read_only, 
+			const U32 presize, 
+			const BOOL remove_after_crash);
+public:
+	~LLVFS();
+
+	// Use this function normally to create LLVFS files
+	// Pass 0 to not presize
+	static LLVFS * createLLVFS(const std::string& index_filename, 
+			const std::string& data_filename, 
+			const BOOL read_only, 
+			const U32 presize, 
+			const BOOL remove_after_crash);
+
+	BOOL isValid() const			{ return (VFSVALID_OK == mValid); }
+	EVFSValid getValidState() const	{ return mValid; }
+
+	// ---------- The following fucntions lock/unlock mDataMutex ----------
+	BOOL getExists(const LLUUID &file_id, const LLAssetType::EType file_type);
+	S32	 getSize(const LLUUID &file_id, const LLAssetType::EType file_type);
+
+	BOOL checkAvailable(S32 max_size);
+	
+	S32  getMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type);
+	BOOL setMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type, S32 max_size);
+
+	void renameFile(const LLUUID &file_id, const LLAssetType::EType file_type,
+		const LLUUID &new_id, const LLAssetType::EType &new_type);
+	void removeFile(const LLUUID &file_id, const LLAssetType::EType file_type);
+
+	S32 getData(const LLUUID &file_id, const LLAssetType::EType file_type, U8 *buffer, S32 location, S32 length);
+	S32 storeData(const LLUUID &file_id, const LLAssetType::EType file_type, const U8 *buffer, S32 location, S32 length);
+
+	void incLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	void decLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	BOOL isLocked(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	// ----------------------------------------------------------------
+
+	// Used to trigger evil WinXP behavior of "preloading" entire file into memory.
+	void pokeFiles();
+
+	// Verify that the index file contents match the in-memory file structure
+	// Very slow, do not call routinely. JC
+	void audit();
+	// Check for uninitialized blocks.  Slow, do not call in release. JC
+	void checkMem();
+	// for debugging, prints a map of the vfs
+	void dumpMap();
+	void dumpLockCounts();
+	void dumpStatistics();
+	void listFiles();
+	void dumpFiles();
+	time_t creationTime();
+
+protected:
+	void removeFileBlock(LLVFSFileBlock *fileblock);
+	
+	void eraseBlockLength(LLVFSBlock *block);
+	void eraseBlock(LLVFSBlock *block);
+	void addFreeBlock(LLVFSBlock *block);
+	//void mergeFreeBlocks();
+	void useFreeSpace(LLVFSBlock *free_block, S32 length);
+	void sync(LLVFSFileBlock *block, BOOL remove = FALSE);
+	void presizeDataFile(const U32 size);
+
+	static LLFILE *openAndLock(const std::string& filename, const char* mode, BOOL read_lock);
+	static void unlockAndClose(FILE *fp);
+	
+	// Can initiate LRU-based file removal to make space.
+	// The immune file block will not be removed.
+	LLVFSBlock *findFreeBlock(S32 size, LLVFSFileBlock *immune = NULL);
+
+	// lock/unlock data mutex (mDataMutex)
+	void lockData() { mDataMutex->lock(); }
+	void unlockData() { mDataMutex->unlock(); }	
+	
+protected:
+	LLMutex* mDataMutex;
+	
+	typedef std::map<LLVFSFileSpecifier, LLVFSFileBlock*> fileblock_map;
+	fileblock_map mFileBlocks;
+
+	typedef std::multimap<S32, LLVFSBlock*>	blocks_length_map_t;
+	blocks_length_map_t 	mFreeBlocksByLength;
+	typedef std::multimap<U32, LLVFSBlock*>	blocks_location_map_t;
+	blocks_location_map_t 	mFreeBlocksByLocation;
+
+	LLFILE *mDataFP;
+	LLFILE *mIndexFP;
+
+	std::deque<S32> mIndexHoles;
+
+	std::string mIndexFilename;
+	std::string mDataFilename;
+	BOOL mReadOnly;
+
+	EVFSValid mValid;
+
+	S32 mLockCounts[VFSLOCK_COUNT];
+	BOOL mRemoveAfterCrash;
+};
+
+extern LLVFS *gVFS;
+
+#endif
diff --git a/indra/llfilesystem/lldir_utils_objc.h b/indra/llvfs/llvfs_objc.h
index 12019c4284..56cdbebfc5 100644
--- a/indra/llfilesystem/lldir_utils_objc.h
+++ b/indra/llvfs/llvfs_objc.h
@@ -1,10 +1,10 @@
 /** 
- * @file lldir_utils_objc.h
+ * @file llvfs_objc.h
  * @brief Definition of directory utilities class for Mac OS X
  *
- * $LicenseInfo:firstyear=2020&license=viewerlgpl$
+ * $LicenseInfo:firstyear=2000&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2020, Linden Research, Inc.
+ * Copyright (C) 2010, Linden Research, Inc.
  * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -28,8 +28,8 @@
 #error This header must not be included when compiling for any target other than Mac OS. Consider including lldir.h instead.
 #endif // !LL_DARWIN
 
-#ifndef LL_LLDIR_UTILS_OBJC_H
-#define LL_LLDIR_UTILS_OBJC_H
+#ifndef LL_LLVFS_OBJC_H
+#define LL_LLVFS_OBJC_H
 
 #include <iostream>
 
@@ -40,4 +40,4 @@ std::string* getSystemResourceFolder();
 std::string* getSystemExecutableFolder();
 
 
-#endif // LL_LLDIR_UTILS_OBJC_H
+#endif // LL_LLVFS_OBJC_H
diff --git a/indra/llfilesystem/lldir_utils_objc.mm b/indra/llvfs/llvfs_objc.mm
index da55a2f897..282ea41339 100644
--- a/indra/llfilesystem/lldir_utils_objc.mm
+++ b/indra/llvfs/llvfs_objc.mm
@@ -1,10 +1,10 @@
 /** 
- * @file lldir_utils_objc.mm
+ * @file llvfs_objc.cpp
  * @brief Cocoa implementation of directory utilities for Mac OS X
  *
- * $LicenseInfo:firstyear=2020&license=viewerlgpl$
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2020, Linden Research, Inc.
+ * Copyright (C) 2010, Linden Research, Inc.
  * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,7 +27,7 @@
 
 //WARNING:  This file CANNOT use standard linden includes due to conflicts between definitions of BOOL
 
-#include "lldir_utils_objc.h"
+#include "llvfs_objc.h"
 #import <Cocoa/Cocoa.h>
 
 std::string* getSystemTempFolder()
diff --git a/indra/llvfs/llvfsthread.cpp b/indra/llvfs/llvfsthread.cpp
new file mode 100644
index 0000000000..8cd85929e2
--- /dev/null
+++ b/indra/llvfs/llvfsthread.cpp
@@ -0,0 +1,300 @@
+/** 
+ * @file llvfsthread.cpp
+ * @brief LLVFSThread implementation
+ *
+ * $LicenseInfo:firstyear=2001&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+#include "llvfsthread.h"
+#include "llstl.h"
+
+//============================================================================
+
+/*static*/ std::string LLVFSThread::sDataPath = "";
+
+/*static*/ LLVFSThread* LLVFSThread::sLocal = NULL;
+
+//============================================================================
+// Run on MAIN thread
+//static
+void LLVFSThread::initClass(bool local_is_threaded)
+{
+	llassert(sLocal == NULL);
+	sLocal = new LLVFSThread(local_is_threaded);
+}
+
+//static
+S32 LLVFSThread::updateClass(U32 ms_elapsed)
+{
+	sLocal->update((F32)ms_elapsed);
+	return sLocal->getPending();
+}
+
+//static
+void LLVFSThread::cleanupClass()
+{
+	sLocal->setQuitting();
+	while (sLocal->getPending())
+	{
+		sLocal->update(0);
+	}
+	delete sLocal;
+	sLocal = 0;
+}
+
+//----------------------------------------------------------------------------
+
+LLVFSThread::LLVFSThread(bool threaded) :
+	LLQueuedThread("VFS", threaded)
+{
+}
+
+LLVFSThread::~LLVFSThread()
+{
+	// ~LLQueuedThread() will be called here
+}
+
+//----------------------------------------------------------------------------
+
+LLVFSThread::handle_t LLVFSThread::read(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+										U8* buffer, S32 offset, S32 numbytes, U32 priority, U32 flags)
+{
+	handle_t handle = generateHandle();
+
+	priority = llmax(priority, (U32)PRIORITY_LOW); // All reads are at least PRIORITY_LOW
+	Request* req = new Request(handle, priority, flags, FILE_READ, vfs, file_id, file_type,
+							   buffer, offset, numbytes);
+
+	bool res = addRequest(req);
+	if (!res)
+	{
+		LL_ERRS() << "LLVFSThread::read called after LLVFSThread::cleanupClass()" << LL_ENDL;
+		req->deleteRequest();
+		handle = nullHandle();
+	}
+
+	return handle;
+}
+
+S32 LLVFSThread::readImmediate(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+							   U8* buffer, S32 offset, S32 numbytes)
+{
+	handle_t handle = generateHandle();
+
+	Request* req = new Request(handle, PRIORITY_IMMEDIATE, 0, FILE_READ, vfs, file_id, file_type,
+							   buffer, offset, numbytes);
+	
+	S32 res = addRequest(req) ? 1 : 0;
+	if (res == 0)
+	{
+		LL_ERRS() << "LLVFSThread::read called after LLVFSThread::cleanupClass()" << LL_ENDL;
+		req->deleteRequest();
+	}
+	else
+	{
+		llverify(waitForResult(handle, false) == true);
+		res = req->getBytesRead();
+		completeRequest(handle);
+	}
+	return res;
+}
+
+LLVFSThread::handle_t LLVFSThread::write(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+										 U8* buffer, S32 offset, S32 numbytes, U32 flags)
+{
+	handle_t handle = generateHandle();
+
+	Request* req = new Request(handle, 0, flags, FILE_WRITE, vfs, file_id, file_type,
+							   buffer, offset, numbytes);
+
+	bool res = addRequest(req);
+	if (!res)
+	{
+		LL_ERRS() << "LLVFSThread::read called after LLVFSThread::cleanupClass()" << LL_ENDL;
+		req->deleteRequest();
+		handle = nullHandle();
+	}
+	
+	return handle;
+}
+
+S32 LLVFSThread::writeImmediate(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+								 U8* buffer, S32 offset, S32 numbytes)
+{
+	handle_t handle = generateHandle();
+
+	Request* req = new Request(handle, PRIORITY_IMMEDIATE, 0, FILE_WRITE, vfs, file_id, file_type,
+							   buffer, offset, numbytes);
+
+	S32 res = addRequest(req) ? 1 : 0;
+	if (res == 0)
+	{
+		LL_ERRS() << "LLVFSThread::read called after LLVFSThread::cleanupClass()" << LL_ENDL;
+		req->deleteRequest();
+	}
+	else
+	{
+		llverify(waitForResult(handle, false) == true);
+		res = req->getBytesRead();
+		completeRequest(handle);
+	}
+	return res;
+}
+
+
+// LLVFSThread::handle_t LLVFSThread::rename(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+// 										  const LLUUID &new_id, const LLAssetType::EType new_type, U32 flags)
+// {
+// 	handle_t handle = generateHandle();
+
+// 	LLUUID* new_idp = new LLUUID(new_id); // deleted with Request
+// 	// new_type is passed as "numbytes"
+// 	Request* req = new Request(handle, 0, flags, FILE_RENAME, vfs, file_id, file_type,
+// 							   (U8*)new_idp, 0, (S32)new_type);
+
+// 	bool res = addRequest(req);
+// 	if (!res)
+// 	{
+// 		LL_ERRS() << "LLVFSThread::read called after LLVFSThread::cleanupClass()" << LL_ENDL;
+// 		req->deleteRequest();
+// 		handle = nullHandle();
+// 	}
+	
+// 	return handle;
+// }
+
+//============================================================================
+
+LLVFSThread::Request::Request(handle_t handle, U32 priority, U32 flags,
+							  operation_t op, LLVFS* vfs,
+							  const LLUUID &file_id, const LLAssetType::EType file_type,
+							  U8* buffer, S32 offset, S32 numbytes) :
+	QueuedRequest(handle, priority, flags),
+	mOperation(op),
+	mVFS(vfs),
+	mFileID(file_id),
+	mFileType(file_type),
+	mBuffer(buffer),
+	mOffset(offset),
+	mBytes(numbytes),
+	mBytesRead(0)
+{
+	llassert(mBuffer);
+
+	if (numbytes <= 0 && mOperation != FILE_RENAME)
+	{
+		LL_WARNS() << "LLVFSThread: Request with numbytes = " << numbytes 
+			<< " operation = " << op
+			<< " offset " << offset 
+			<< " file_type " << file_type << LL_ENDL;
+	}
+	if (mOperation == FILE_WRITE)
+	{
+		S32 blocksize =  mVFS->getMaxSize(mFileID, mFileType);
+		if (blocksize < 0)
+		{
+			LL_WARNS() << "VFS write to temporary block (shouldn't happen)" << LL_ENDL;
+		}
+		mVFS->incLock(mFileID, mFileType, VFSLOCK_APPEND);
+	}
+	else if (mOperation == FILE_RENAME)
+	{
+		mVFS->incLock(mFileID, mFileType, VFSLOCK_APPEND);
+	}
+	else // if (mOperation == FILE_READ)
+	{
+		mVFS->incLock(mFileID, mFileType, VFSLOCK_READ);
+	}
+}
+
+// dec locks as soon as a request finishes
+void LLVFSThread::Request::finishRequest(bool completed)
+{
+	if (mOperation == FILE_WRITE)
+	{
+		mVFS->decLock(mFileID, mFileType, VFSLOCK_APPEND);
+	}
+	else if (mOperation == FILE_RENAME)
+	{
+		mVFS->decLock(mFileID, mFileType, VFSLOCK_APPEND);
+	}
+	else // if (mOperation == FILE_READ)
+	{
+		mVFS->decLock(mFileID, mFileType, VFSLOCK_READ);
+	}
+}
+
+void LLVFSThread::Request::deleteRequest()
+{
+	if (getStatus() == STATUS_QUEUED)
+	{
+		LL_ERRS() << "Attempt to delete a queued LLVFSThread::Request!" << LL_ENDL;
+	}	
+	if (mOperation == FILE_WRITE)
+	{
+		if (mFlags & FLAG_AUTO_DELETE)
+		{
+			delete [] mBuffer;
+		}
+	}
+	else if (mOperation == FILE_RENAME)
+	{
+		LLUUID* new_idp = (LLUUID*)mBuffer;
+		delete new_idp;
+	}
+	LLQueuedThread::QueuedRequest::deleteRequest();
+}
+
+bool LLVFSThread::Request::processRequest()
+{
+	bool complete = false;
+	if (mOperation ==  FILE_READ)
+	{
+		llassert(mOffset >= 0);
+		mBytesRead = mVFS->getData(mFileID, mFileType, mBuffer, mOffset, mBytes);
+		complete = true;
+		//LL_INFOS() << llformat("LLVFSThread::READ '%s': %d bytes arg:%d",getFilename(),mBytesRead) << LL_ENDL;
+	}
+	else if (mOperation ==  FILE_WRITE)
+	{
+		mBytesRead = mVFS->storeData(mFileID, mFileType, mBuffer, mOffset, mBytes);
+		complete = true;
+		//LL_INFOS() << llformat("LLVFSThread::WRITE '%s': %d bytes arg:%d",getFilename(),mBytesRead) << LL_ENDL;
+	}
+	else if (mOperation ==  FILE_RENAME)
+	{
+		LLUUID* new_idp = (LLUUID*)mBuffer;
+		LLAssetType::EType new_type = (LLAssetType::EType)mBytes;
+		mVFS->renameFile(mFileID, mFileType, *new_idp, new_type);
+		mFileID = *new_idp;
+		complete = true;
+		//LL_INFOS() << llformat("LLVFSThread::RENAME '%s': %d bytes arg:%d",getFilename(),mBytesRead) << LL_ENDL;
+	}
+	else
+	{
+		LL_ERRS() << llformat("LLVFSThread::unknown operation: %d", mOperation) << LL_ENDL;
+	}
+	return complete;
+}
+
+//============================================================================
diff --git a/indra/llvfs/llvfsthread.h b/indra/llvfs/llvfsthread.h
new file mode 100644
index 0000000000..7814de4a2d
--- /dev/null
+++ b/indra/llvfs/llvfsthread.h
@@ -0,0 +1,140 @@
+/** 
+ * @file llvfsthread.h
+ * @brief LLVFSThread definition
+ *
+ * $LicenseInfo:firstyear=2001&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLVFSTHREAD_H
+#define LL_LLVFSTHREAD_H
+
+#include <queue>
+#include <string>
+#include <map>
+#include <set>
+
+#include "llqueuedthread.h"
+
+#include "llvfs.h"
+
+//============================================================================
+
+class LLVFSThread : public LLQueuedThread
+{
+	//------------------------------------------------------------------------
+public:
+	enum operation_t {
+		FILE_READ,
+		FILE_WRITE,
+		FILE_RENAME
+	};
+
+	//------------------------------------------------------------------------
+public:
+
+	class Request : public QueuedRequest
+	{
+	protected:
+		~Request() {}; // use deleteRequest()
+		
+	public:
+		Request(handle_t handle, U32 priority, U32 flags,
+				operation_t op, LLVFS* vfs,
+				const LLUUID &file_id, const LLAssetType::EType file_type,
+				U8* buffer, S32 offset, S32 numbytes);
+
+		S32 getBytesRead()
+		{
+			return mBytesRead;
+		}
+		S32 getOperation()
+		{
+			return mOperation;
+		}
+		U8* getBuffer()
+		{
+			return mBuffer;
+		}
+		LLVFS* getVFS()
+		{
+			return mVFS;
+		}
+		std::string getFilename()
+		{
+			std::string tstring;
+			mFileID.toString(tstring);
+			return tstring;
+		}
+		
+		/*virtual*/ bool processRequest();
+		/*virtual*/ void finishRequest(bool completed);
+		/*virtual*/ void deleteRequest();
+		
+	private:
+		operation_t mOperation;
+		
+		LLVFS* mVFS;
+		LLUUID mFileID;
+		LLAssetType::EType mFileType;
+		
+		U8* mBuffer;	// dest for reads, source for writes, new UUID for rename
+		S32 mOffset;	// offset into file, -1 = append (WRITE only)
+		S32 mBytes;		// bytes to read from file, -1 = all (new mFileType for rename)
+		S32	mBytesRead;	// bytes read from file
+	};
+
+	//------------------------------------------------------------------------
+public:
+	static std::string sDataPath;
+	static LLVFSThread* sLocal;		// Default worker thread
+	
+public:
+	LLVFSThread(bool threaded = TRUE);
+	~LLVFSThread();	
+
+	// Return a Request handle
+	handle_t read(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,	/* Flawfinder: ignore */
+				  U8* buffer, S32 offset, S32 numbytes, U32 pri=PRIORITY_NORMAL, U32 flags = 0);
+	handle_t write(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+				   U8* buffer, S32 offset, S32 numbytes, U32 flags);
+	// SJB: rename seems to have issues, especially when threaded
+// 	handle_t rename(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+// 					const LLUUID &new_id, const LLAssetType::EType new_type, U32 flags);
+	// Return number of bytes read
+	S32 readImmediate(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+					  U8* buffer, S32 offset, S32 numbytes);
+	S32 writeImmediate(LLVFS* vfs, const LLUUID &file_id, const LLAssetType::EType file_type,
+					   U8* buffer, S32 offset, S32 numbytes);
+
+	/*virtual*/ bool processRequest(QueuedRequest* req);
+
+public:
+	static void initClass(bool local_is_threaded = TRUE); // Setup sLocal
+	static S32 updateClass(U32 ms_elapsed);
+	static void cleanupClass();		// Delete sLocal
+	static void setDataPath(const std::string& path) { sDataPath = path; }
+};
+
+//============================================================================
+
+
+#endif // LL_LLVFSTHREAD_H
diff --git a/indra/llfilesystem/tests/lldir_test.cpp b/indra/llvfs/tests/lldir_test.cpp
index 3cff622a4b..3cff622a4b 100644
--- a/indra/llfilesystem/tests/lldir_test.cpp
+++ b/indra/llvfs/tests/lldir_test.cpp
diff --git a/indra/llfilesystem/tests/lldiriterator_test.cpp b/indra/llvfs/tests/lldiriterator_test.cpp
index a65e3dada5..a65e3dada5 100644
--- a/indra/llfilesystem/tests/lldiriterator_test.cpp
+++ b/indra/llvfs/tests/lldiriterator_test.cpp
diff --git a/indra/llwindow/CMakeLists.txt b/indra/llwindow/CMakeLists.txt
index 70eb99c86c..8bfb23ed64 100644
--- a/indra/llwindow/CMakeLists.txt
+++ b/indra/llwindow/CMakeLists.txt
@@ -16,7 +16,7 @@ include(LLCommon)
 include(LLImage)
 include(LLMath)
 include(LLRender)
-include(LLFileSystem)
+include(LLVFS)
 include(LLWindow)
 include(LLXML)
 include(UI)
@@ -26,7 +26,7 @@ include_directories(
     ${LLIMAGE_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     )
@@ -72,7 +72,7 @@ if (LINUX)
       ${LLIMAGE_LIBRARIES}
       ${LLMATH_LIBRARIES}
       ${LLRENDER_LIBRARIES}
-      ${LLFILESYSTEM_LIBRARIES}
+      ${LLVFS_LIBRARIES}
       ${LLWINDOW_LIBRARIES}
       ${LLXML_LIBRARIES}
       ${UI_LIBRARIES}     # for GTK
@@ -95,7 +95,7 @@ if (LINUX)
         ${LLIMAGE_LIBRARIES}
         ${LLMATH_LIBRARIES}
         ${LLRENDER_HEADLESS_LIBRARIES}
-        ${LLFILESYSTEM_LIBRARIES}
+        ${LLVFS_LIBRARIES}
         ${LLWINDOW_HEADLESS_LIBRARIES}
         ${LLXML_LIBRARIES}
         fontconfig          # For FCInit and other FC* functions.
diff --git a/indra/llxml/CMakeLists.txt b/indra/llxml/CMakeLists.txt
index 3a7a54e51d..013a422d35 100644
--- a/indra/llxml/CMakeLists.txt
+++ b/indra/llxml/CMakeLists.txt
@@ -5,13 +5,13 @@ project(llxml)
 include(00-Common)
 include(LLCommon)
 include(LLMath)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 
 include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     )
 include_directories(
     ${LLCOMMON_SYSTEM_INCLUDE_DIRS}
@@ -42,7 +42,7 @@ add_library (llxml ${llxml_SOURCE_FILES})
 # Libraries on which this library depends, needed for Linux builds
 # Sort by high-level to low-level
 target_link_libraries( llxml
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
     ${EXPAT_LIBRARIES}
diff --git a/indra/mac_crash_logger/CMakeLists.txt b/indra/mac_crash_logger/CMakeLists.txt
index 75621d7b75..95637c9a28 100644
--- a/indra/mac_crash_logger/CMakeLists.txt
+++ b/indra/mac_crash_logger/CMakeLists.txt
@@ -8,7 +8,7 @@ include(LLCoreHttp)
 include(LLCrashLogger)
 include(LLMath)
 include(LLMessage)
-include(LLFilesystem)
+include(LLVFS)
 include(LLXML)
 include(Linking)
 include(LLSharedLibs)
@@ -19,7 +19,7 @@ include_directories(
     ${LLCOMMON_INCLUDE_DIRS}
     ${LLCRASHLOGGER_INCLUDE_DIRS}
     ${LLMATH_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     )
 include_directories(SYSTEM
@@ -68,10 +68,11 @@ find_library(COCOA_LIBRARY Cocoa)
 
 target_link_libraries(mac-crash-logger
     ${LLCRASHLOGGER_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${COCOA_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOREHTTP_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
diff --git a/indra/mac_crash_logger/mac_crash_logger.cpp b/indra/mac_crash_logger/mac_crash_logger.cpp
index 66d8cfa590..54e41a1954 100644
--- a/indra/mac_crash_logger/mac_crash_logger.cpp
+++ b/indra/mac_crash_logger/mac_crash_logger.cpp
@@ -27,6 +27,7 @@
 #include "linden_common.h"
 #include "llcrashloggermac.h"
 #include "indra_constants.h"
+#include "llpidlock.h"
 
 #include <iostream>
     
diff --git a/indra/newview/CMakeLists.txt b/indra/newview/CMakeLists.txt
index 82e6cda193..3439951e80 100644
--- a/indra/newview/CMakeLists.txt
+++ b/indra/newview/CMakeLists.txt
@@ -39,7 +39,7 @@ include(LLPlugin)
 include(LLPrimitive)
 include(LLRender)
 include(LLUI)
-include(LLFileSystem)
+include(LLVFS)
 include(LLWindow)
 include(LLXML)
 include(NDOF)
@@ -84,7 +84,7 @@ include_directories(
     ${LLPRIMITIVE_INCLUDE_DIRS}
     ${LLRENDER_INCLUDE_DIRS}
     ${LLUI_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     ${LLLOGIN_INCLUDE_DIRS}
@@ -2016,7 +2016,7 @@ target_link_libraries(${VIEWER_BINARY_NAME}
     ${LLRENDER_LIBRARIES}
     ${FREETYPE_LIBRARIES}
     ${LLUI_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLWINDOW_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMATH_LIBRARIES}
@@ -2492,7 +2492,7 @@ if (LL_TESTS)
   set(test_libs
     ${LLMESSAGE_LIBRARIES}
     ${WINDOWS_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
     ${GOOGLEMOCK_LIBRARIES}
@@ -2507,7 +2507,7 @@ if (LL_TESTS)
 
   set(test_libs
     ${WINDOWS_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLMATH_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
diff --git a/indra/newview/VIEWER_VERSION.txt b/indra/newview/VIEWER_VERSION.txt
index 9cc52c876b..dbe6222fdd 100644
--- a/indra/newview/VIEWER_VERSION.txt
+++ b/indra/newview/VIEWER_VERSION.txt
@@ -1 +1 @@
-6.4.15
+6.4.17
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 393a38fb9c..c0166f158e 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -1362,39 +1362,6 @@
       <key>Value</key>
       <integer>23</integer>
     </map>
-    <key>EnableCacheDebugInfo</key>
-    <map>
-      <key>Comment</key>
-      <string>When set, display additional cache debugging information</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>Boolean</string>
-      <key>Value</key>
-      <integer>0</integer>
-    </map>
-    <key>DiskCachePercentOfTotal</key>
-    <map>
-      <key>Comment</key>
-      <string>The percent of total cache size (defined by CacheSize) to use for the disk cache</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>F32</string>
-      <key>Value</key>
-      <real>20.0</real>
-    </map>
-    <key>DiskCacheDirName</key>
-    <map>
-      <key>Comment</key>
-      <string>The name of the disk cache (within the standard Viewer disk cache directory)</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>String</string>
-      <key>Value</key>
-      <string>cache</string>
-    </map>
     <key>CacheLocation</key>
     <map>
       <key>Comment</key>
@@ -2868,6 +2835,17 @@
       <key>Value</key>
       <integer>-1</integer>
     </map>
+    <key>DebugStatModeVFSPendingOps</key>
+    <map>
+      <key>Comment</key>
+      <string>Mode of stat in Statistics floater</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>S32</string>
+      <key>Value</key>
+      <integer>-1</integer>
+    </map>
     <key>DebugStatModeTimeDialation</key>
     <map>
       <key>Comment</key>
@@ -3660,6 +3638,17 @@
       <key>Value</key>
       <integer>4</integer>
     </map>
+    <key>DumpVFSCaches</key>
+    <map>
+      <key>Comment</key>
+      <string>Dump VFS caches on startup.</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
     <key>DynamicCameraStrength</key>
     <map>
       <key>Comment</key>
@@ -11591,7 +11580,7 @@
             <string>Boolean</string>
         <key>Value</key>
             <integer>0</integer>
-    </map>
+    </map> 
     <key>NearbyListShowMap</key>
     <map>
       <key>Comment</key>
@@ -14269,6 +14258,28 @@
       <key>Value</key>
       <string/>
     </map>
+    <key>VFSOldSize</key>
+    <map>
+      <key>Comment</key>
+      <string>[DO NOT MODIFY] Controls resizing of local file cache</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>U32</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
+    <key>VFSSalt</key>
+    <map>
+      <key>Comment</key>
+      <string>[DO NOT MODIFY] Controls local file caching behavior</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>U32</string>
+      <key>Value</key>
+      <integer>1</integer>
+    </map>
     <key>VelocityInterpolate</key>
     <map>
       <key>Comment</key>
@@ -16610,7 +16621,7 @@
       <key>Type</key>
       <string>Boolean</string>
       <key>Value</key>
-      <integer>1</integer>
+      <integer>1</integer>        
     </map>
 </map>
 </llsd>
diff --git a/indra/newview/app_settings/static_data.db2 b/indra/newview/app_settings/static_data.db2
new file mode 100644
index 0000000000..f85aa81601
--- /dev/null
+++ b/indra/newview/app_settings/static_data.db2
diff --git a/indra/newview/app_settings/static_index.db2 b/indra/newview/app_settings/static_index.db2
new file mode 100644
index 0000000000..a5440f96f2
--- /dev/null
+++ b/indra/newview/app_settings/static_index.db2
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index ea0b950e62..f518704e06 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -98,7 +98,6 @@
 #include "lllogininstance.h"
 #include "llprogressview.h"
 #include "llvocache.h"
-#include "lldiskcache.h"
 #include "llvopartgroup.h"
 #include "llweb.h"
 #include "llfloatertexturefetchdebugger.h"
@@ -116,6 +115,8 @@
 #include "llprimitive.h"
 #include "llurlaction.h"
 #include "llurlentry.h"
+#include "llvfile.h"
+#include "llvfsthread.h"
 #include "llvolumemgr.h"
 #include "llxfermanager.h"
 #include "llphysicsextensions.h"
@@ -339,6 +340,9 @@ bool			gUseWireframe = FALSE;
 //use for remember deferred mode in wireframe switch
 bool			gInitialDeferredModeForWireframe = FALSE;
 
+// VFS globals - see llappviewer.h
+LLVFS* gStaticVFS = NULL;
+
 LLMemoryInfo gSysMemory;
 U64Bytes gMemoryAllocated(0); // updated in display_stats() in llviewerdisplay.cpp
 
@@ -427,6 +431,12 @@ void init_default_trans_args()
 	default_trans_args.insert("create_account_url");
 }
 
+//----------------------------------------------------------------------------
+// File scope definitons
+const char *VFS_DATA_FILE_BASE = "data.db2.x.";
+const char *VFS_INDEX_FILE_BASE = "index.db2.x.";
+
+
 struct SettingsFile : public LLInitParam::Block<SettingsFile>
 {
 	Mandatory<std::string>	name;
@@ -961,6 +971,10 @@ bool LLAppViewer::init()
 
 	// *Note: this is where gViewerStats used to be created.
 
+	//
+	// Initialize the VFS, and gracefully handle initialization errors
+	//
+
 	if (!initCache())
 	{
 		LL_WARNS("InitInfo") << "Failed to init cache" << LL_ENDL;
@@ -1355,6 +1369,7 @@ static LLTrace::BlockTimerStatHandle FTM_TEXTURE_CACHE("Texture Cache");
 static LLTrace::BlockTimerStatHandle FTM_DECODE("Image Decode");
 static LLTrace::BlockTimerStatHandle FTM_FETCH("Image Fetch");
 
+static LLTrace::BlockTimerStatHandle FTM_VFS("VFS Thread");
 static LLTrace::BlockTimerStatHandle FTM_LFS("LFS Thread");
 static LLTrace::BlockTimerStatHandle FTM_PAUSE_THREADS("Pause Threads");
 static LLTrace::BlockTimerStatHandle FTM_IDLE("Idle");
@@ -1589,13 +1604,17 @@ bool LLAppViewer::doFrame()
 				work_pending += updateTextureThreads(max_time);
 
 				{
+					LL_RECORD_BLOCK_TIME(FTM_VFS);
+ 					io_pending += LLVFSThread::updateClass(1);
+				}
+				{
 					LL_RECORD_BLOCK_TIME(FTM_LFS);
  					io_pending += LLLFSThread::updateClass(1);
 				}
 
 				if (io_pending > 1000)
 				{
-					ms_sleep(llmin(io_pending/100,100)); // give the lfs some time to catch up
+					ms_sleep(llmin(io_pending/100,100)); // give the vfs some time to catch up
 				}
 
 				total_work_pending += work_pending ;
@@ -1612,6 +1631,7 @@ bool LLAppViewer::doFrame()
 			}
 			if(!total_io_pending) //pause file threads if nothing to process.
 			{
+				LLVFSThread::sLocal->pause();
 				LLLFSThread::sLocal->pause();
 			}
 
@@ -1673,11 +1693,12 @@ S32 LLAppViewer::updateTextureThreads(F32 max_time)
 	return work_pending;
 }
 
-void LLAppViewer::flushLFSIO()
+void LLAppViewer::flushVFSIO()
 {
 	while (1)
 	{
-		S32 pending = LLLFSThread::updateClass(0);
+		S32 pending = LLVFSThread::updateClass(0);
+		pending += LLLFSThread::updateClass(0);
 		if (!pending)
 		{
 			break;
@@ -1765,7 +1786,7 @@ bool LLAppViewer::cleanup()
 
 	LLKeyframeDataCache::clear();
 
- 	// End TransferManager before deleting systems it depends on (Audio, AssetStorage)
+ 	// End TransferManager before deleting systems it depends on (Audio, VFS, AssetStorage)
 #if 0 // this seems to get us stuck in an infinite loop...
 	gTransferManager.cleanup();
 #endif
@@ -1832,8 +1853,8 @@ bool LLAppViewer::cleanup()
 
 	LL_INFOS() << "Cache files removed" << LL_ENDL;
 
-	// Wait for any pending LFS IO
-	flushLFSIO();
+	// Wait for any pending VFS IO
+	flushVFSIO();
 	LL_INFOS() << "Shutting down Views" << LL_ENDL;
 
 	// Destroy the UI
@@ -1917,6 +1938,15 @@ bool LLAppViewer::cleanup()
 	SUBSYSTEM_CLEANUP(LLWorldMapView);
 	SUBSYSTEM_CLEANUP(LLFolderViewItem);
 
+	//
+	// Shut down the VFS's AFTER the decode manager cleans up (since it cleans up vfiles).
+	// Also after viewerwindow is deleted, since it may have image pointers (which have vfiles)
+	// Also after shutting down the messaging system since it has VFS dependencies
+
+	//
+	LL_INFOS() << "Cleaning up VFS" << LL_ENDL;
+	SUBSYSTEM_CLEANUP(LLVFile);
+
 	LL_INFOS() << "Saving Data" << LL_ENDL;
 
 	// Store the time of our current logoff
@@ -2003,6 +2033,7 @@ bool LLAppViewer::cleanup()
 		pending += LLAppViewer::getTextureCache()->update(1); // unpauses the worker thread
 		pending += LLAppViewer::getImageDecodeThread()->update(1); // unpauses the image thread
 		pending += LLAppViewer::getTextureFetch()->update(1); // unpauses the texture fetch thread
+		pending += LLVFSThread::updateClass(0);
 		pending += LLLFSThread::updateClass(0);
 		F64 idle_time = idleTimer.getElapsedTimeF64();
 		if(!pending)
@@ -2077,11 +2108,28 @@ bool LLAppViewer::cleanup()
 	gTextureList.shutdown(); // shutdown again in case a callback added something
 	LLUIImageList::getInstance()->cleanUp();
 
+	// This should eventually be done in LLAppViewer
 	SUBSYSTEM_CLEANUP(LLImage);
+	SUBSYSTEM_CLEANUP(LLVFSThread);
 	SUBSYSTEM_CLEANUP(LLLFSThread);
 
+#ifndef LL_RELEASE_FOR_DOWNLOAD
+	LL_INFOS() << "Auditing VFS" << LL_ENDL;
+	if(gVFS)
+	{
+		gVFS->audit();
+	}
+#endif
+
 	LL_INFOS() << "Misc Cleanup" << LL_ENDL;
 
+	// For safety, the LLVFS has to be deleted *after* LLVFSThread. This should be cleaned up.
+	// (LLVFS doesn't know about LLVFSThread so can't kill pending requests) -Steve
+	delete gStaticVFS;
+	gStaticVFS = NULL;
+	delete gVFS;
+	gVFS = NULL;
+
 	gSavedSettings.cleanup();
 	LLUIColorTable::instance().clear();
 
@@ -2163,6 +2211,7 @@ bool LLAppViewer::initThreads()
 
 	LLImage::initClass(gSavedSettings.getBOOL("TextureNewByteRange"),gSavedSettings.getS32("TextureReverseByteRange"));
 
+	LLVFSThread::initClass(enable_threads && false);
 	LLLFSThread::initClass(enable_threads && false);
 
 	// Image decoding
@@ -3164,6 +3213,10 @@ LLSD LLAppViewer::getViewerInfo() const
     info["GPU_SHADERS"] = gSavedSettings.getBOOL("RenderDeferred") ? "Enabled" : "Disabled";
     info["TEXTURE_MEMORY"] = gSavedSettings.getS32("TextureMemory");
 
+    LLSD substitution;
+    substitution["datetime"] = (S32)(gVFS ? gVFS->creationTime() : 0);
+    info["VFS_TIME"] = LLTrans::getString("AboutTime", substitution);
+
 #if LL_DARWIN
     info["HIDPI"] = gHiDPISupport;
 #endif
@@ -3255,9 +3308,6 @@ LLSD LLAppViewer::getViewerInfo() const
 		info["SERVER_RELEASE_NOTES_URL"] = mServerReleaseNotesURL;
 	}
 
-    // populate field for new local disk cache with some details
-    info["DISK_CACHE_INFO"] = LLDiskCache::getInstance()->getCacheInfo();
-
 	return info;
 }
 
@@ -3907,7 +3957,7 @@ void LLAppViewer::forceQuit()
 void LLAppViewer::fastQuit(S32 error_code)
 {
 	// finish pending transfers
-	flushLFSIO();
+	flushVFSIO();
 	// let sim know we're logging out
 	sendLogoutRequest();
 	// flush network buffers by shutting down messaging system
@@ -4096,6 +4146,39 @@ void LLAppViewer::migrateCacheDirectory()
 #endif // LL_WINDOWS || LL_DARWIN
 }
 
+void dumpVFSCaches()
+{
+	LL_INFOS() << "======= Static VFS ========" << LL_ENDL;
+	gStaticVFS->listFiles();
+#if LL_WINDOWS
+	LL_INFOS() << "======= Dumping static VFS to StaticVFSDump ========" << LL_ENDL;
+	WCHAR w_str[MAX_PATH];
+	GetCurrentDirectory(MAX_PATH, w_str);
+	S32 res = LLFile::mkdir("StaticVFSDump");
+	if (res == -1)
+	{
+		LL_WARNS() << "Couldn't create dir StaticVFSDump" << LL_ENDL;
+	}
+	SetCurrentDirectory(utf8str_to_utf16str("StaticVFSDump").c_str());
+	gStaticVFS->dumpFiles();
+	SetCurrentDirectory(w_str);
+#endif
+
+	LL_INFOS() << "========= Dynamic VFS ====" << LL_ENDL;
+	gVFS->listFiles();
+#if LL_WINDOWS
+	LL_INFOS() << "========= Dumping dynamic VFS to VFSDump ====" << LL_ENDL;
+	res = LLFile::mkdir("VFSDump");
+	if (res == -1)
+	{
+		LL_WARNS() << "Couldn't create dir VFSDump" << LL_ENDL;
+	}
+	SetCurrentDirectory(utf8str_to_utf16str("VFSDump").c_str());
+	gVFS->dumpFiles();
+	SetCurrentDirectory(w_str);
+#endif
+}
+
 //static
 U32 LLAppViewer::getTextureCacheVersion()
 {
@@ -4122,19 +4205,6 @@ bool LLAppViewer::initCache()
 	LLAppViewer::getTextureCache()->setReadOnly(read_only) ;
 	LLVOCache::initParamSingleton(read_only);
 
-	// initialize the new disk cache using saved settings
-	const std::string cache_dir_name = gSavedSettings.getString("DiskCacheDirName");
-
-    // note that the maximum size of this cache is defined as a percentage of the 
-    // total cache size - the 'CacheSize' pref - for all caches. 
-    const unsigned int cache_total_size_mb = gSavedSettings.getU32("CacheSize");
-    const double disk_cache_percent = gSavedSettings.getF32("DiskCachePercentOfTotal");
-    const unsigned int disk_cache_mb = cache_total_size_mb * disk_cache_percent / 100;
-    const unsigned int disk_cache_bytes = disk_cache_mb * 1024 * 1024;
-	const bool enable_cache_debug_info = gSavedSettings.getBOOL("EnableDiskCacheDebugInfo");
-	const std::string cache_dir = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, cache_dir_name);
-	LLDiskCache::initParamSingleton(cache_dir, disk_cache_bytes, enable_cache_debug_info);
-
 	bool texture_cache_mismatch = false;
 	if (gSavedSettings.getS32("LocalCacheVersion") != LLAppViewer::getTextureCacheVersion())
 	{
@@ -4181,21 +4251,10 @@ bool LLAppViewer::initCache()
 		gSavedSettings.setString("CacheLocationTopFolder", "");
 	}
 
-	if (!read_only)
+	if (mPurgeCache && !read_only)
 	{
-		if (mPurgeCache)
-		{
-			LLSplashScreen::update(LLTrans::getString("StartupClearingCache"));
-			purgeCache();
-
-			// clear the new C++ file system based cache
-			LLDiskCache::getInstance()->clearCache();
-		}
-		else
-		{
-			// purge excessive files from the new file system based cache
-			LLDiskCache::getInstance()->purge();
-		}
+		LLSplashScreen::update(LLTrans::getString("StartupClearingCache"));
+		purgeCache();
 	}
 
 	LLSplashScreen::update(LLTrans::getString("StartupInitializingTextureCache"));
@@ -4205,18 +4264,172 @@ bool LLAppViewer::initCache()
 	const S32 MB = 1024 * 1024;
 	const S64 MIN_CACHE_SIZE = 256 * MB;
 	const S64 MAX_CACHE_SIZE = 9984ll * MB;
+	const S64 MAX_VFS_SIZE = 1024 * MB; // 1 GB
 
 	S64 cache_size = (S64)(gSavedSettings.getU32("CacheSize")) * MB;
 	cache_size = llclamp(cache_size, MIN_CACHE_SIZE, MAX_CACHE_SIZE);
 
-	S64 texture_cache_size = cache_size;
+	S64 vfs_size = llmin((S64)((cache_size * 2) / 10), MAX_VFS_SIZE);
+	S64 texture_cache_size = cache_size - vfs_size;
 
 	S64 extra = LLAppViewer::getTextureCache()->initCache(LL_PATH_CACHE, texture_cache_size, texture_cache_mismatch);
 	texture_cache_size -= extra;
 
+
 	LLVOCache::getInstance()->initCache(LL_PATH_CACHE, gSavedSettings.getU32("CacheNumberOfRegionsForObjects"), getObjectCacheVersion());
 
-    return true;
+	LLSplashScreen::update(LLTrans::getString("StartupInitializingVFS"));
+
+	// Init the VFS
+	vfs_size = llmin(vfs_size + extra, MAX_VFS_SIZE);
+	vfs_size = (vfs_size / MB) * MB; // make sure it is MB aligned
+	U32 vfs_size_u32 = (U32)vfs_size;
+	U32 old_vfs_size = gSavedSettings.getU32("VFSOldSize") * MB;
+	bool resize_vfs = (vfs_size_u32 != old_vfs_size);
+	if (resize_vfs)
+	{
+		gSavedSettings.setU32("VFSOldSize", vfs_size_u32 / MB);
+	}
+	LL_INFOS("AppCache") << "VFS CACHE SIZE: " << vfs_size / (1024*1024) << " MB" << LL_ENDL;
+
+	// This has to happen BEFORE starting the vfs
+	// time_t	ltime;
+	srand(time(NULL));		// Flawfinder: ignore
+	U32 old_salt = gSavedSettings.getU32("VFSSalt");
+	U32 new_salt;
+	std::string old_vfs_data_file;
+	std::string old_vfs_index_file;
+	std::string new_vfs_data_file;
+	std::string new_vfs_index_file;
+	std::string static_vfs_index_file;
+	std::string static_vfs_data_file;
+
+	if (gSavedSettings.getBOOL("AllowMultipleViewers"))
+	{
+		// don't mess with renaming the VFS in this case
+		new_salt = old_salt;
+	}
+	else
+	{
+		do
+		{
+			new_salt = rand();
+		} while(new_salt == old_salt);
+	}
+
+	old_vfs_data_file = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, VFS_DATA_FILE_BASE) + llformat("%u", old_salt);
+
+	// make sure this file exists
+	llstat s;
+	S32 stat_result = LLFile::stat(old_vfs_data_file, &s);
+	if (stat_result)
+	{
+		// doesn't exist, look for a data file
+		std::string mask;
+		mask = VFS_DATA_FILE_BASE;
+		mask += "*";
+
+		std::string dir;
+		dir = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, "");
+
+		std::string found_file;
+		LLDirIterator iter(dir, mask);
+		if (iter.next(found_file))
+		{
+			old_vfs_data_file = gDirUtilp->add(dir, found_file);
+
+			S32 start_pos = found_file.find_last_of('.');
+			if (start_pos > 0)
+			{
+				sscanf(found_file.substr(start_pos+1).c_str(), "%d", &old_salt);
+			}
+			LL_DEBUGS("AppCache") << "Default vfs data file not present, found: " << old_vfs_data_file << " Old salt: " << old_salt << LL_ENDL;
+		}
+	}
+
+	old_vfs_index_file = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, VFS_INDEX_FILE_BASE) + llformat("%u", old_salt);
+
+	stat_result = LLFile::stat(old_vfs_index_file, &s);
+	if (stat_result)
+	{
+		// We've got a bad/missing index file, nukem!
+		LL_WARNS("AppCache") << "Bad or missing vfx index file " << old_vfs_index_file << LL_ENDL;
+		LL_WARNS("AppCache") << "Removing old vfs data file " << old_vfs_data_file << LL_ENDL;
+		LLFile::remove(old_vfs_data_file);
+		LLFile::remove(old_vfs_index_file);
+
+		// Just in case, nuke any other old cache files in the directory.
+		std::string dir;
+		dir = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, "");
+
+		std::string mask;
+		mask = VFS_DATA_FILE_BASE;
+		mask += "*";
+
+		gDirUtilp->deleteFilesInDir(dir, mask);
+
+		mask = VFS_INDEX_FILE_BASE;
+		mask += "*";
+
+		gDirUtilp->deleteFilesInDir(dir, mask);
+	}
+
+	new_vfs_data_file = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, VFS_DATA_FILE_BASE) + llformat("%u", new_salt);
+	new_vfs_index_file = gDirUtilp->getExpandedFilename(LL_PATH_CACHE, VFS_INDEX_FILE_BASE) + llformat("%u", new_salt);
+
+	static_vfs_data_file = gDirUtilp->getExpandedFilename(LL_PATH_APP_SETTINGS, "static_data.db2");
+	static_vfs_index_file = gDirUtilp->getExpandedFilename(LL_PATH_APP_SETTINGS, "static_index.db2");
+
+	if (resize_vfs)
+	{
+		LL_DEBUGS("AppCache") << "Removing old vfs and re-sizing" << LL_ENDL;
+
+		LLFile::remove(old_vfs_data_file);
+		LLFile::remove(old_vfs_index_file);
+	}
+	else if (old_salt != new_salt)
+	{
+		// move the vfs files to a new name before opening
+		LL_DEBUGS("AppCache") << "Renaming " << old_vfs_data_file << " to " << new_vfs_data_file << LL_ENDL;
+		LL_DEBUGS("AppCache") << "Renaming " << old_vfs_index_file << " to " << new_vfs_index_file << LL_ENDL;
+		LLFile::rename(old_vfs_data_file, new_vfs_data_file);
+		LLFile::rename(old_vfs_index_file, new_vfs_index_file);
+	}
+
+	// Startup the VFS...
+	gSavedSettings.setU32("VFSSalt", new_salt);
+
+	// Don't remove VFS after viewer crashes.  If user has corrupt data, they can reinstall. JC
+	gVFS = LLVFS::createLLVFS(new_vfs_index_file, new_vfs_data_file, false, vfs_size_u32, false);
+	if (!gVFS)
+	{
+		return false;
+	}
+
+	gStaticVFS = LLVFS::createLLVFS(static_vfs_index_file, static_vfs_data_file, true, 0, false);
+	if (!gStaticVFS)
+	{
+		return false;
+	}
+
+	BOOL success = gVFS->isValid() && gStaticVFS->isValid();
+	if (!success)
+	{
+		return false;
+	}
+	else
+	{
+		LLVFile::initClass();
+
+#ifndef LL_RELEASE_FOR_DOWNLOAD
+		if (gSavedSettings.getBOOL("DumpVFSCaches"))
+		{
+			dumpVFSCaches();
+		}
+#endif
+
+		return true;
+	}
 }
 
 void LLAppViewer::addOnIdleCallback(const boost::function<void()>& cb)
diff --git a/indra/newview/llappviewer.h b/indra/newview/llappviewer.h
index 902b94d495..5332fe2deb 100644
--- a/indra/newview/llappviewer.h
+++ b/indra/newview/llappviewer.h
@@ -1,6 +1,5 @@
 /** 
  * @mainpage
- * @mainpage
  *
  * This is the sources for the Second Life Viewer;
  * information on the open source project is at 
@@ -83,7 +82,7 @@ public:
 	virtual bool frame(); // Override for application body logic
 
 	// Application control
-	void flushLFSIO(); // waits for lfs transfers to complete
+	void flushVFSIO(); // waits for vfs transfers to complete
 	void forceQuit(); // Puts the viewer into 'shutting down without error' mode.
 	void fastQuit(S32 error_code = 0); // Shuts down the viewer immediately after sending a logout message
 	void requestQuit(); // Request a quit. A kinder, gentler quit.
@@ -382,6 +381,12 @@ extern BOOL			gRestoreGL;
 extern bool		gUseWireframe;
 extern bool		gInitialDeferredModeForWireframe;
 
+// VFS globals - gVFS is for general use
+// gStaticVFS is read-only and is shipped w/ the viewer
+// it has pre-cache data like the UI .TGAs
+class LLVFS;
+extern LLVFS	*gStaticVFS;
+
 extern LLMemoryInfo gSysMemory;
 extern U64Bytes gMemoryAllocated;
 
diff --git a/indra/newview/llappviewerwin32.cpp b/indra/newview/llappviewerwin32.cpp
index 84ffb3551d..9b1c0d1f8b 100644
--- a/indra/newview/llappviewerwin32.cpp
+++ b/indra/newview/llappviewerwin32.cpp
@@ -502,7 +502,7 @@ void LLAppViewerWin32::disableWinErrorReporting()
 	}
 }
 
-const S32 MAX_CONSOLE_LINES = 7500;
+const S32 MAX_CONSOLE_LINES = 500;
 // Only defined in newer SDKs than we currently use
 #ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
 #define ENABLE_VIRTUAL_TERMINAL_PROCESSING 4
diff --git a/indra/newview/llcompilequeue.cpp b/indra/newview/llcompilequeue.cpp
index 5d010a6f1e..3aaaaf52f5 100644
--- a/indra/newview/llcompilequeue.cpp
+++ b/indra/newview/llcompilequeue.cpp
@@ -52,7 +52,7 @@
 #include "lldir.h"
 #include "llnotificationsutil.h"
 #include "llviewerstats.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "lluictrlfactory.h"
 #include "lltrans.h"
 
@@ -116,7 +116,7 @@ namespace
 }
 
 // *NOTE$: A minor specialization of LLScriptAssetUpload, it does not require a buffer 
-// (and does not save a buffer to the cache) and it finds the compile queue window and 
+// (and does not save a buffer to the vFS) and it finds the compile queue window and 
 // displays a compiling message.
 class LLQueuedScriptAssetUpload : public LLScriptAssetUpload
 {
@@ -134,8 +134,8 @@ public:
     virtual LLSD prepareUpload()
     {
         /* *NOTE$: The parent class (LLScriptAssetUpload will attempt to save 
-         * the script buffer into to the cache.  Since the resource is already in 
-         * the cache we don't want to do that.  Just put a compiling message in
+         * the script buffer into to the VFS.  Since the resource is already in 
+         * the VFS we don't want to do that.  Just put a compiling message in
          * the window and move on
          */
         LLFloaterCompileQueue* queue = LLFloaterReg::findTypedInstance<LLFloaterCompileQueue>("compile_queue", LLSD(mQueueId));
@@ -283,11 +283,11 @@ void LLFloaterCompileQueue::handleHTTPResponse(std::string pumpName, const LLSD
     LLEventPumps::instance().post(pumpName, expresult);
 }
 
-// *TODO: handleSCriptRetrieval is passed into the cache via a legacy C function pointer
+// *TODO: handleSCriptRetrieval is passed into the VFS via a legacy C function pointer
 // future project would be to convert these to C++ callables (std::function<>) so that 
 // we can use bind and remove the userData parameter.
 // 
-void LLFloaterCompileQueue::handleScriptRetrieval(const LLUUID& assetId, 
+void LLFloaterCompileQueue::handleScriptRetrieval(LLVFS *vfs, const LLUUID& assetId, 
     LLAssetType::EType type, void* userData, S32 status, LLExtStat extStatus)
 {
     LLSD result(LLSD::emptyMap());
diff --git a/indra/newview/llcompilequeue.h b/indra/newview/llcompilequeue.h
index a9bac345b5..adb854875a 100644
--- a/indra/newview/llcompilequeue.h
+++ b/indra/newview/llcompilequeue.h
@@ -135,7 +135,7 @@ protected:
 
     //bool checkAssetId(const LLUUID &assetId);
     static void handleHTTPResponse(std::string pumpName, const LLSD &expresult);
-    static void handleScriptRetrieval(const LLUUID& assetId, LLAssetType::EType type, void* userData, S32 status, LLExtStat extStatus);
+    static void handleScriptRetrieval(LLVFS *vfs, const LLUUID& assetId, LLAssetType::EType type, void* userData, S32 status, LLExtStat extStatus);
 
 private:
     static void processExperienceIdResults(LLSD result, LLUUID parent);
diff --git a/indra/newview/llfilepicker.h b/indra/newview/llfilepicker.h
index 04ba4416d7..2fc496a144 100644
--- a/indra/newview/llfilepicker.h
+++ b/indra/newview/llfilepicker.h
@@ -136,7 +136,7 @@ public:
 
 	S32 getFileCount() const { return (S32)mFiles.size(); }
 
-	// see lldir.h : getBaseFileName and getDirName to extract base or directory names
+	// See llvfs/lldir.h : getBaseFileName and getDirName to extract base or directory names
 	
 	// clear any lists of buffers or whatever, and make sure the file
 	// picker isn't locked.
diff --git a/indra/newview/llfloaterauction.cpp b/indra/newview/llfloaterauction.cpp
index 9813156bf2..957b2e1e8e 100644
--- a/indra/newview/llfloaterauction.cpp
+++ b/indra/newview/llfloaterauction.cpp
@@ -32,7 +32,8 @@
 #include "llimagej2c.h"
 #include "llimagetga.h"
 #include "llparcel.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llwindow.h"
 #include "message.h"
 
@@ -201,9 +202,7 @@ void LLFloaterAuction::onClickSnapshot(void* data)
 
 		LLPointer<LLImageTGA> tga = new LLImageTGA;
 		tga->encode(raw);
-
-		LLFileSystem tga_file(self->mImageID, LLAssetType::AT_IMAGE_TGA, LLFileSystem::WRITE);
-		tga_file.write(tga->getData(), tga->getDataSize());
+		LLVFile::writeFile(tga->getData(), tga->getDataSize(), gVFS, self->mImageID, LLAssetType::AT_IMAGE_TGA);
 		
 		raw->biasedScaleToPowerOfTwo(LLViewerTexture::MAX_IMAGE_SIZE_DEFAULT);
 
@@ -211,9 +210,7 @@ void LLFloaterAuction::onClickSnapshot(void* data)
 
 		LLPointer<LLImageJ2C> j2c = new LLImageJ2C;
 		j2c->encode(raw, 0.0f);
-
-		LLFileSystem j2c_file(self->mImageID, LLAssetType::AT_TEXTURE, LLFileSystem::WRITE);
-		j2c_file.write(j2c->getData(), j2c->getDataSize());
+		LLVFile::writeFile(j2c->getData(), j2c->getDataSize(), gVFS, self->mImageID, LLAssetType::AT_TEXTURE);
 
 		self->mImage = LLViewerTextureManager::getLocalTexture((LLImageRaw*)raw, FALSE);
 		gGL.getTexUnit(0)->bind(self->mImage);
diff --git a/indra/newview/llfloaterbvhpreview.cpp b/indra/newview/llfloaterbvhpreview.cpp
index 687d820a18..131d9b077b 100644
--- a/indra/newview/llfloaterbvhpreview.cpp
+++ b/indra/newview/llfloaterbvhpreview.cpp
@@ -32,7 +32,7 @@
 #include "lldatapacker.h"
 #include "lldir.h"
 #include "llnotificationsutil.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llapr.h"
 #include "llstring.h"
 
@@ -997,9 +997,10 @@ void LLFloaterBvhPreview::onBtnOK(void* userdata)
 		LLDataPackerBinaryBuffer dp(buffer, file_size);
 		if (motionp->serialize(dp))
 		{
-			LLFileSystem file(motionp->getID(), LLAssetType::AT_ANIMATION, LLFileSystem::APPEND);
+			LLVFile file(gVFS, motionp->getID(), LLAssetType::AT_ANIMATION, LLVFile::APPEND);
 
 			S32 size = dp.getCurrentSize();
+			file.setMaxSize(size);
 			if (file.write((U8*)buffer, size))
 			{
 				std::string name = floaterp->getChild<LLUICtrl>("name_form")->getValue().asString();
diff --git a/indra/newview/llfloatermodelpreview.cpp b/indra/newview/llfloatermodelpreview.cpp
index 481a7dab66..b9c03f66a3 100644
--- a/indra/newview/llfloatermodelpreview.cpp
+++ b/indra/newview/llfloatermodelpreview.cpp
@@ -59,7 +59,6 @@
 #include "llspinctrl.h"
 #include "lltabcontainer.h"
 #include "lltrans.h"
-#include "llfilesystem.h"
 #include "llcallbacklist.h"
 #include "llviewertexteditor.h"
 #include "llviewernetwork.h"
diff --git a/indra/newview/llfloaterpreference.h b/indra/newview/llfloaterpreference.h
index f99d0e6150..526214a617 100644
--- a/indra/newview/llfloaterpreference.h
+++ b/indra/newview/llfloaterpreference.h
@@ -107,7 +107,7 @@ protected:
 	void		onBtnOK(const LLSD& userdata);
 	void		onBtnCancel(const LLSD& userdata);
 
-	void		onClickClearCache();			// Clear viewer texture cache, file cache on next startup
+	void		onClickClearCache();			// Clear viewer texture cache, vfs, and VO cache on next startup
 	void		onClickBrowserClearCache();		// Clear web history and caches as well as viewer caches above
 	void		onLanguageChange();
 	void		onNotificationsChange(const std::string& OptionName);
diff --git a/indra/newview/llfloaterregioninfo.cpp b/indra/newview/llfloaterregioninfo.cpp
index 0375c15467..ec1909d02a 100644
--- a/indra/newview/llfloaterregioninfo.cpp
+++ b/indra/newview/llfloaterregioninfo.cpp
@@ -36,7 +36,7 @@
 #include "llglheaders.h"
 #include "llregionflags.h"
 #include "llstl.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llxfermanager.h"
 #include "indra_constants.h"
 #include "message.h"
@@ -2229,9 +2229,10 @@ void LLPanelEstateCovenant::loadInvItem(LLInventoryItem *itemp)
 }
 
 // static
-void LLPanelEstateCovenant::onLoadComplete(const LLUUID& asset_uuid,
-									       LLAssetType::EType type,
-									       void* user_data, S32 status, LLExtStat ext_status)
+void LLPanelEstateCovenant::onLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
+									   LLAssetType::EType type,
+									   void* user_data, S32 status, LLExtStat ext_status)
 {
 	LL_INFOS() << "LLPanelEstateCovenant::onLoadComplete()" << LL_ENDL;
 	LLPanelEstateCovenant* panelp = (LLPanelEstateCovenant*)user_data;
@@ -2239,7 +2240,7 @@ void LLPanelEstateCovenant::onLoadComplete(const LLUUID& asset_uuid,
 	{
 		if(0 == status)
 		{
-			LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+			LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 
 			S32 file_length = file.getSize();
 
diff --git a/indra/newview/llfloaterregioninfo.h b/indra/newview/llfloaterregioninfo.h
index c34dbb62e8..75d0c3ea5c 100644
--- a/indra/newview/llfloaterregioninfo.h
+++ b/indra/newview/llfloaterregioninfo.h
@@ -55,6 +55,7 @@ class LLRadioGroup;
 class LLSliderCtrl;
 class LLSpinCtrl;
 class LLTextBox;
+class LLVFS;
 
 class LLPanelRegionGeneralInfo;
 class LLPanelRegionDebugInfo;
@@ -356,7 +357,8 @@ public:
 	static bool confirmResetCovenantCallback(const LLSD& notification, const LLSD& response);
 	void sendChangeCovenantID(const LLUUID &asset_id);
 	void loadInvItem(LLInventoryItem *itemp);
-	static void onLoadComplete(const LLUUID& asset_uuid,
+	static void onLoadComplete(LLVFS *vfs,
+							   const LLUUID& asset_uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 
diff --git a/indra/newview/llfloaterreporter.cpp b/indra/newview/llfloaterreporter.cpp
index 5d0e2bbc55..7bfba2a6d7 100644
--- a/indra/newview/llfloaterreporter.cpp
+++ b/indra/newview/llfloaterreporter.cpp
@@ -44,7 +44,8 @@
 #include "llnotificationsutil.h"
 #include "llstring.h"
 #include "llsys.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "mean_collision_data.h"
 #include "message.h"
 #include "v3math.h"
@@ -898,9 +899,12 @@ void LLFloaterReporter::takeScreenshot(bool use_prev_screenshot)
 	mResourceDatap->mAssetInfo.setName("screenshot_name");
 	mResourceDatap->mAssetInfo.setDescription("screenshot_descr");
 
-	// store in cache
-    LLFileSystem j2c_file(mResourceDatap->mAssetInfo.mUuid, mResourceDatap->mAssetInfo.mType, LLFileSystem::WRITE);
-    j2c_file.write(upload_data->getData(), upload_data->getDataSize());
+	// store in VFS
+	LLVFile::writeFile(upload_data->getData(), 
+						upload_data->getDataSize(), 
+						gVFS, 
+						mResourceDatap->mAssetInfo.mUuid, 
+						mResourceDatap->mAssetInfo.mType);
 
 	// store in the image list so it doesn't try to fetch from the server
 	LLPointer<LLViewerFetchedTexture> image_in_list = 
diff --git a/indra/newview/llfloatertos.cpp b/indra/newview/llfloatertos.cpp
index 1aeb727172..bd403f68d7 100644
--- a/indra/newview/llfloatertos.cpp
+++ b/indra/newview/llfloatertos.cpp
@@ -40,7 +40,7 @@
 #include "lltextbox.h"
 #include "llui.h"
 #include "lluictrlfactory.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "message.h"
 #include "llstartup.h"              // login_alert_done
 #include "llcorehttputil.h"
diff --git a/indra/newview/llfloatertos.h b/indra/newview/llfloatertos.h
index 7c2f0705b7..85033acf4d 100644
--- a/indra/newview/llfloatertos.h
+++ b/indra/newview/llfloatertos.h
@@ -36,6 +36,7 @@
 
 class LLButton;
 class LLRadioGroup;
+class LLVFS;
 class LLTextEditor;
 class LLUUID;
 
diff --git a/indra/newview/llgesturemgr.cpp b/indra/newview/llgesturemgr.cpp
index 9f2119281d..950a6cfaef 100644
--- a/indra/newview/llgesturemgr.cpp
+++ b/indra/newview/llgesturemgr.cpp
@@ -42,7 +42,7 @@
 #include "llnotificationsutil.h"
 #include "llstl.h"
 #include "llstring.h"	// todo: remove
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "message.h"
 
 // newview
@@ -548,7 +548,7 @@ void LLGestureMgr::playGesture(LLMultiGesture* gesture)
 				LLGestureStepAnimation* anim_step = (LLGestureStepAnimation*)step;
 				const LLUUID& anim_id = anim_step->mAnimAssetID;
 
-				// Don't request the animation if this step stops it or if it is already in the cache
+				// Don't request the animation if this step stops it or if it is already in Static VFS
 				if (!(anim_id.isNull()
 					  || anim_step->mFlags & ANIM_FLAG_STOP
 					  || gAssetStorage->hasLocalAsset(anim_id, LLAssetType::AT_ANIMATION)))
@@ -1038,9 +1038,10 @@ void LLGestureMgr::runStep(LLMultiGesture* gesture, LLGestureStep* step)
 
 
 // static
-void LLGestureMgr::onLoadComplete(const LLUUID& asset_uuid,
-								  LLAssetType::EType type,
-								  void* user_data, S32 status, LLExtStat ext_status)
+void LLGestureMgr::onLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
+									   LLAssetType::EType type,
+									   void* user_data, S32 status, LLExtStat ext_status)
 {
 	LLLoadInfo* info = (LLLoadInfo*)user_data;
 
@@ -1055,7 +1056,7 @@ void LLGestureMgr::onLoadComplete(const LLUUID& asset_uuid,
 
 	if (0 == status)
 	{
-		LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+		LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 		S32 size = file.getSize();
 
 		std::vector<char> buffer(size+1);
@@ -1158,7 +1159,8 @@ void LLGestureMgr::onLoadComplete(const LLUUID& asset_uuid,
 }
 
 // static
-void LLGestureMgr::onAssetLoadComplete(const LLUUID& asset_uuid,
+void LLGestureMgr::onAssetLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
 									   LLAssetType::EType type,
 									   void* user_data, S32 status, LLExtStat ext_status)
 {
@@ -1170,7 +1172,7 @@ void LLGestureMgr::onAssetLoadComplete(const LLUUID& asset_uuid,
 	{
 	case LLAssetType::AT_ANIMATION:
 		{
-			LLKeyframeMotion::onLoadComplete(asset_uuid, type, user_data, status, ext_status);
+			LLKeyframeMotion::onLoadComplete(vfs, asset_uuid, type, user_data, status, ext_status);
 
 			self.mLoadingAssets.erase(asset_uuid);
 
@@ -1178,7 +1180,7 @@ void LLGestureMgr::onAssetLoadComplete(const LLUUID& asset_uuid,
 		}
 	case LLAssetType::AT_SOUND:
 		{
-			LLAudioEngine::assetCallback(asset_uuid, type, user_data, status, ext_status);
+			LLAudioEngine::assetCallback(vfs, asset_uuid, type, user_data, status, ext_status);
 
 			self.mLoadingAssets.erase(asset_uuid);
 
diff --git a/indra/newview/llgesturemgr.h b/indra/newview/llgesturemgr.h
index 91ab445273..402bdf6039 100644
--- a/indra/newview/llgesturemgr.h
+++ b/indra/newview/llgesturemgr.h
@@ -40,6 +40,7 @@ class LLMultiGesture;
 class LLGestureListener;
 class LLGestureStep;
 class LLUUID;
+class LLVFS;
 
 class LLGestureManagerObserver
 {
@@ -153,13 +154,15 @@ protected:
 	void done();
 
 	// Used by loadGesture
-	static void onLoadComplete(const LLUUID& asset_uuid,
-					           LLAssetType::EType type,
-						       void* user_data, S32 status, LLExtStat ext_status);
+	static void onLoadComplete(LLVFS *vfs,
+						   const LLUUID& asset_uuid,
+						   LLAssetType::EType type,
+						   void* user_data, S32 status, LLExtStat ext_status);
 
 	// Used by playGesture to load an asset file
 	// required to play a gesture step
-	static void onAssetLoadComplete(const LLUUID& asset_uuid,
+	static void onAssetLoadComplete(LLVFS *vfs,
+									const LLUUID& asset_uuid,
 									LLAssetType::EType type,
 									void* user_data, S32 status, LLExtStat ext_status);
 
diff --git a/indra/newview/lllandmarklist.cpp b/indra/newview/lllandmarklist.cpp
index 2966ca1f10..b4236c406b 100644
--- a/indra/newview/lllandmarklist.cpp
+++ b/indra/newview/lllandmarklist.cpp
@@ -33,7 +33,7 @@
 
 #include "llappviewer.h"
 #include "llagent.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llviewerstats.h"
 
 // Globals
@@ -118,6 +118,7 @@ LLLandmark* LLLandmarkList::getAsset(const LLUUID& asset_uuid, loaded_callback_t
 
 // static
 void LLLandmarkList::processGetAssetReply(
+	LLVFS *vfs,
 	const LLUUID& uuid,
 	LLAssetType::EType type,
 	void* user_data,
@@ -126,7 +127,7 @@ void LLLandmarkList::processGetAssetReply(
 {
 	if( status == 0 )
 	{
-		LLFileSystem file(uuid, type);
+		LLVFile file(vfs, uuid, type);
 		S32 file_length = file.getSize();
 
 		std::vector<char> buffer(file_length + 1);
diff --git a/indra/newview/lllandmarklist.h b/indra/newview/lllandmarklist.h
index 0e4859dbc9..2e7bd25610 100644
--- a/indra/newview/lllandmarklist.h
+++ b/indra/newview/lllandmarklist.h
@@ -52,6 +52,7 @@ public:
 	BOOL assetExists(const LLUUID& asset_uuid);
 	LLLandmark* getAsset(const LLUUID& asset_uuid, loaded_callback_t cb = NULL);
 	static void processGetAssetReply(
+		LLVFS *vfs,
 		const LLUUID& uuid,
 		LLAssetType::EType type,
 		void* user_data,
diff --git a/indra/newview/llmeshrepository.cpp b/indra/newview/llmeshrepository.cpp
index 8e5bdc0225..3e8731dfe6 100644
--- a/indra/newview/llmeshrepository.cpp
+++ b/indra/newview/llmeshrepository.cpp
@@ -49,7 +49,7 @@
 #include "llsdutil_math.h"
 #include "llsdserialize.h"
 #include "llthread.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llviewercontrol.h"
 #include "llviewerinventory.h"
 #include "llviewermenufile.h"
@@ -294,6 +294,8 @@
 //   * Header parse failures come without much explanation.  Elaborate.
 //   * Work queue for uploads?  Any need for this or is the current scheme good
 //     enough?
+//   * Various temp buffers used in VFS I/O might be allocated once or even
+//     statically.  Look for some wins here.
 //   * Move data structures holding mesh data used by main thread into main-
 //     thread-only access so that no locking is needed.  May require duplication
 //     of some data so that worker thread has a minimal data set to guide
@@ -1334,8 +1336,8 @@ bool LLMeshRepoThread::fetchMeshSkinInfo(const LLUUID& mesh_id)
 
 		if (version <= MAX_MESH_VERSION && offset >= 0 && size > 0)
 		{
-			//check cache for mesh skin info
-			LLFileSystem file(mesh_id, LLAssetType::AT_MESH);
+			//check VFS for mesh skin info
+			LLVFile file(gVFS, mesh_id, LLAssetType::AT_MESH);
 			if (file.getSize() >= offset+size)
 			{
 				U8* buffer = new(std::nothrow) U8[size];
@@ -1368,7 +1370,7 @@ bool LLMeshRepoThread::fetchMeshSkinInfo(const LLUUID& mesh_id)
 				delete[] buffer;
 			}
 
-			//reading from cache failed for whatever reason, fetch from sim
+			//reading from VFS failed for whatever reason, fetch from sim
 			std::string http_url;
 			constructUrl(mesh_id, &http_url);
 
@@ -1430,8 +1432,8 @@ bool LLMeshRepoThread::fetchMeshDecomposition(const LLUUID& mesh_id)
 
 		if (version <= MAX_MESH_VERSION && offset >= 0 && size > 0)
 		{
-			//check cache for mesh skin info
-			LLFileSystem file(mesh_id, LLAssetType::AT_MESH);
+			//check VFS for mesh skin info
+			LLVFile file(gVFS, mesh_id, LLAssetType::AT_MESH);
 			if (file.getSize() >= offset+size)
 			{
 				U8* buffer = new(std::nothrow) U8[size];
@@ -1465,7 +1467,7 @@ bool LLMeshRepoThread::fetchMeshDecomposition(const LLUUID& mesh_id)
 				delete[] buffer;
 			}
 
-			//reading from cache failed for whatever reason, fetch from sim
+			//reading from VFS failed for whatever reason, fetch from sim
 			std::string http_url;
 			constructUrl(mesh_id, &http_url);
 			
@@ -1527,8 +1529,8 @@ bool LLMeshRepoThread::fetchMeshPhysicsShape(const LLUUID& mesh_id)
 
 		if (version <= MAX_MESH_VERSION && offset >= 0 && size > 0)
 		{
-			//check cache for mesh physics shape info
-			LLFileSystem file(mesh_id, LLAssetType::AT_MESH);
+			//check VFS for mesh physics shape info
+			LLVFile file(gVFS, mesh_id, LLAssetType::AT_MESH);
 			if (file.getSize() >= offset+size)
 			{
 				LLMeshRepository::sCacheBytesRead += size;
@@ -1561,7 +1563,7 @@ bool LLMeshRepoThread::fetchMeshPhysicsShape(const LLUUID& mesh_id)
 				delete[] buffer;
 			}
 
-			//reading from cache failed for whatever reason, fetch from sim
+			//reading from VFS failed for whatever reason, fetch from sim
 			std::string http_url;
 			constructUrl(mesh_id, &http_url);
 			
@@ -1632,8 +1634,8 @@ bool LLMeshRepoThread::fetchMeshHeader(const LLVolumeParams& mesh_params, bool c
 	++LLMeshRepository::sMeshRequestCount;
 
 	{
-		//look for mesh in asset in cache
-		LLFileSystem file(mesh_params.getSculptID(), LLAssetType::AT_MESH);
+		//look for mesh in asset in vfs
+		LLVFile file(gVFS, mesh_params.getSculptID(), LLAssetType::AT_MESH);
 			
 		S32 size = file.getSize();
 
@@ -1647,7 +1649,7 @@ bool LLMeshRepoThread::fetchMeshHeader(const LLVolumeParams& mesh_params, bool c
 			file.read(buffer, bytes);
 			if (headerReceived(mesh_params, buffer, bytes) == MESH_OK)
 			{
-				// Found mesh in cache
+				// Found mesh in VFS cache
 				return true;
 			}
 		}
@@ -1711,8 +1713,8 @@ bool LLMeshRepoThread::fetchMeshLOD(const LLVolumeParams& mesh_params, S32 lod,
 		if (version <= MAX_MESH_VERSION && offset >= 0 && size > 0)
 		{
 
-			//check cache for mesh asset
-			LLFileSystem file(mesh_id, LLAssetType::AT_MESH);
+			//check VFS for mesh asset
+			LLVFile file(gVFS, mesh_id, LLAssetType::AT_MESH);
 			if (file.getSize() >= offset+size)
 			{
 				U8* buffer = new(std::nothrow) U8[size];
@@ -1747,7 +1749,7 @@ bool LLMeshRepoThread::fetchMeshLOD(const LLVolumeParams& mesh_params, S32 lod,
 				delete[] buffer;
 			}
 
-			//reading from cache failed for whatever reason, fetch from sim
+			//reading from VFS failed for whatever reason, fetch from sim
 			std::string http_url;
 			constructUrl(mesh_id, &http_url);
 			
@@ -3206,7 +3208,7 @@ void LLMeshHeaderHandler::processData(LLCore::BufferArray * /* body */, S32 /* b
 	}
 	else if (data && data_size > 0)
 	{
-		// header was successfully retrieved from sim and parsed and is in cache
+		// header was successfully retrieved from sim and parsed, cache in vfs
 		S32 header_bytes = 0;
 		LLSD header;
 
@@ -3245,16 +3247,31 @@ void LLMeshHeaderHandler::processData(LLCore::BufferArray * /* body */, S32 /* b
 
 		
 			// It's possible for the remote asset to have more data than is needed for the local cache
-			// only allocate as much space in the cache as is needed for the local cache
+			// only allocate as much space in the VFS as is needed for the local cache
 			data_size = llmin(data_size, bytes);
 
-			LLFileSystem file(mesh_id, LLAssetType::AT_MESH, LLFileSystem::WRITE);
-			if (file.getMaxSize() >= bytes)
+			LLVFile file(gVFS, mesh_id, LLAssetType::AT_MESH, LLVFile::WRITE);
+			if (file.getMaxSize() >= bytes || file.setMaxSize(bytes))
 			{
 				LLMeshRepository::sCacheBytesWritten += data_size;
 				++LLMeshRepository::sCacheWrites;
 
 				file.write(data, data_size);
+			
+				// zero out the rest of the file 
+				U8 block[MESH_HEADER_SIZE];
+				memset(block, 0, sizeof(block));
+
+				while (bytes-file.tell() > sizeof(block))
+				{
+					file.write(block, sizeof(block));
+				}
+
+				S32 remaining = bytes-file.tell();
+				if (remaining > 0)
+				{
+					file.write(block, remaining);
+				}
 			}
 		}
 		else
@@ -3306,8 +3323,8 @@ void LLMeshLODHandler::processData(LLCore::BufferArray * /* body */, S32 /* body
 		EMeshProcessingResult result = gMeshRepo.mThread->lodReceived(mMeshParams, mLOD, data, data_size);
 		if (result == MESH_OK)
 		{
-			// good fetch from sim, write to cache
-			LLFileSystem file(mMeshParams.getSculptID(), LLAssetType::AT_MESH, LLFileSystem::WRITE);
+			// good fetch from sim, write to VFS for caching
+			LLVFile file(gVFS, mMeshParams.getSculptID(), LLAssetType::AT_MESH, LLVFile::WRITE);
 
 			S32 offset = mOffset;
 			S32 size = mRequestedBytes;
@@ -3370,8 +3387,8 @@ void LLMeshSkinInfoHandler::processData(LLCore::BufferArray * /* body */, S32 /*
 		&& ((data != NULL) == (data_size > 0)) // if we have data but no size or have size but no data, something is wrong
 		&& gMeshRepo.mThread->skinInfoReceived(mMeshID, data, data_size))
 	{
-		// good fetch from sim, write to cache
-		LLFileSystem file(mMeshID, LLAssetType::AT_MESH, LLFileSystem::WRITE);
+		// good fetch from sim, write to VFS for caching
+		LLVFile file(gVFS, mMeshID, LLAssetType::AT_MESH, LLVFile::WRITE);
 
 		S32 offset = mOffset;
 		S32 size = mRequestedBytes;
@@ -3418,8 +3435,8 @@ void LLMeshDecompositionHandler::processData(LLCore::BufferArray * /* body */, S
 		&& ((data != NULL) == (data_size > 0)) // if we have data but no size or have size but no data, something is wrong
 		&& gMeshRepo.mThread->decompositionReceived(mMeshID, data, data_size))
 	{
-		// good fetch from sim, write to cache
-		LLFileSystem file(mMeshID, LLAssetType::AT_MESH, LLFileSystem::WRITE);
+		// good fetch from sim, write to VFS for caching
+		LLVFile file(gVFS, mMeshID, LLAssetType::AT_MESH, LLVFile::WRITE);
 
 		S32 offset = mOffset;
 		S32 size = mRequestedBytes;
@@ -3465,8 +3482,8 @@ void LLMeshPhysicsShapeHandler::processData(LLCore::BufferArray * /* body */, S3
 		&& ((data != NULL) == (data_size > 0)) // if we have data but no size or have size but no data, something is wrong
 		&& gMeshRepo.mThread->physicsShapeReceived(mMeshID, data, data_size) == MESH_OK)
 	{
-		// good fetch from sim, write to cache for caching
-		LLFileSystem file(mMeshID, LLAssetType::AT_MESH, LLFileSystem::WRITE);
+		// good fetch from sim, write to VFS for caching
+		LLVFile file(gVFS, mMeshID, LLAssetType::AT_MESH, LLVFile::WRITE);
 
 		S32 offset = mOffset;
 		S32 size = mRequestedBytes;
diff --git a/indra/newview/llmeshrepository.h b/indra/newview/llmeshrepository.h
index 441264d42f..81e49cb1d8 100644
--- a/indra/newview/llmeshrepository.h
+++ b/indra/newview/llmeshrepository.h
@@ -48,6 +48,7 @@
 class LLVOVolume;
 class LLMutex;
 class LLCondition;
+class LLVFS;
 class LLMeshRepository;
 
 typedef enum e_mesh_processing_result_enum
diff --git a/indra/newview/lloutfitgallery.cpp b/indra/newview/lloutfitgallery.cpp
index 90f6d23a61..272e7ae351 100644
--- a/indra/newview/lloutfitgallery.cpp
+++ b/indra/newview/lloutfitgallery.cpp
@@ -32,7 +32,7 @@
 
 // llcommon
 #include "llcommonutils.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 
 #include "llaccordionctrltab.h"
 #include "llappearancemgr.h"
diff --git a/indra/newview/lloutfitgallery.h b/indra/newview/lloutfitgallery.h
index ce5c090134..6dd8a6298f 100644
--- a/indra/newview/lloutfitgallery.h
+++ b/indra/newview/lloutfitgallery.h
@@ -38,6 +38,7 @@
 
 #include <vector>
 
+class LLVFS;
 class LLOutfitGallery;
 class LLOutfitGalleryItem;
 class LLOutfitListGearMenuBase;
diff --git a/indra/newview/llpostcard.cpp b/indra/newview/llpostcard.cpp
index 071fc31d27..d5775042c1 100644
--- a/indra/newview/llpostcard.cpp
+++ b/indra/newview/llpostcard.cpp
@@ -28,7 +28,8 @@
 
 #include "llpostcard.h"
 
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llviewerregion.h"
 
 #include "message.h"
diff --git a/indra/newview/llpreviewgesture.cpp b/indra/newview/llpreviewgesture.cpp
index 4318a55704..70ce275734 100644
--- a/indra/newview/llpreviewgesture.cpp
+++ b/indra/newview/llpreviewgesture.cpp
@@ -30,7 +30,7 @@
 #include "llagent.h"
 #include "llanimstatelabels.h"
 #include "llanimationstates.h"
-#include "llappviewer.h"
+#include "llappviewer.h"			// gVFS
 #include "llcheckboxctrl.h"
 #include "llcombobox.h"
 #include "lldatapacker.h"
@@ -47,7 +47,7 @@
 #include "llradiogroup.h"
 #include "llresmgr.h"
 #include "lltrans.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llviewerobjectlist.h"
 #include "llviewerregion.h"
 #include "llviewerstats.h"
@@ -841,9 +841,10 @@ void LLPreviewGesture::loadAsset()
 
 
 // static
-void LLPreviewGesture::onLoadComplete(const LLUUID& asset_uuid,
-									  LLAssetType::EType type,
-									  void* user_data, S32 status, LLExtStat ext_status)
+void LLPreviewGesture::onLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
+									   LLAssetType::EType type,
+									   void* user_data, S32 status, LLExtStat ext_status)
 {
 	LLUUID* item_idp = (LLUUID*)user_data;
 
@@ -852,7 +853,7 @@ void LLPreviewGesture::onLoadComplete(const LLUUID& asset_uuid,
 	{
 		if (0 == status)
 		{
-			LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+			LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 			S32 size = file.getSize();
 
 			std::vector<char> buffer(size+1);
@@ -1137,9 +1138,10 @@ void LLPreviewGesture::saveIfNeeded()
             tid.generate();
             assetId = tid.makeAssetID(gAgent.getSecureSessionID());
 
-            LLFileSystem file(assetId, LLAssetType::AT_GESTURE, LLFileSystem::APPEND);
+            LLVFile file(gVFS, assetId, LLAssetType::AT_GESTURE, LLVFile::APPEND);
 
             S32 size = dp.getCurrentSize();
+            file.setMaxSize(size);
             file.write((U8*)buffer, size);
 
             LLLineEditor* descEditor = getChild<LLLineEditor>("desc");
diff --git a/indra/newview/llpreviewgesture.h b/indra/newview/llpreviewgesture.h
index 19bccf35bd..3ba4f56295 100644
--- a/indra/newview/llpreviewgesture.h
+++ b/indra/newview/llpreviewgesture.h
@@ -39,6 +39,7 @@ class LLScrollListCtrl;
 class LLScrollListItem;
 class LLButton;
 class LLRadioGroup;
+class LLVFS;
 
 class LLPreviewGesture : public LLPreview
 {
@@ -79,7 +80,8 @@ protected:
 
 	void loadAsset();
 
-	static void onLoadComplete(const LLUUID& asset_uuid,
+	static void onLoadComplete(LLVFS *vfs,
+							   const LLUUID& asset_uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 
diff --git a/indra/newview/llpreviewnotecard.cpp b/indra/newview/llpreviewnotecard.cpp
index a7bb5c8236..1b60610668 100644
--- a/indra/newview/llpreviewnotecard.cpp
+++ b/indra/newview/llpreviewnotecard.cpp
@@ -46,7 +46,7 @@
 #include "llselectmgr.h"
 #include "lltrans.h"
 #include "llviewertexteditor.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llviewerinventory.h"
 #include "llviewerobject.h"
 #include "llviewerobjectlist.h"
@@ -327,7 +327,8 @@ void LLPreviewNotecard::loadAsset()
 }
 
 // static
-void LLPreviewNotecard::onLoadComplete(const LLUUID& asset_uuid,
+void LLPreviewNotecard::onLoadComplete(LLVFS *vfs,
+									   const LLUUID& asset_uuid,
 									   LLAssetType::EType type,
 									   void* user_data, S32 status, LLExtStat ext_status)
 {
@@ -338,7 +339,7 @@ void LLPreviewNotecard::onLoadComplete(const LLUUID& asset_uuid,
 	{
 		if(0 == status)
 		{
-			LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+			LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 
 			S32 file_length = file.getSize();
 
@@ -445,7 +446,7 @@ void LLPreviewNotecard::finishInventoryUpload(LLUUID itemId, LLUUID newAssetId,
     LLPreviewNotecard* nc = LLFloaterReg::findTypedInstance<LLPreviewNotecard>("preview_notecard", LLSD(itemId));
     if (nc)
     {
-        // *HACK: we have to delete the asset in the cache so
+        // *HACK: we have to delete the asset in the VFS so
         // that the viewer will redownload it. This is only
         // really necessary if the asset had to be modified by
         // the uploader, so this can be optimized away in some
@@ -453,7 +454,7 @@ void LLPreviewNotecard::finishInventoryUpload(LLUUID itemId, LLUUID newAssetId,
         // script actually changed the asset.
         if (nc->hasEmbeddedInventory())
         {
-            LLFileSystem::removeFile(newAssetId, LLAssetType::AT_NOTECARD);
+            gVFS->removeFile(newAssetId, LLAssetType::AT_NOTECARD);
         }
         if (newItemId.isNull())
         {
@@ -478,7 +479,7 @@ void LLPreviewNotecard::finishTaskUpload(LLUUID itemId, LLUUID newAssetId, LLUUI
     {
         if (nc->hasEmbeddedInventory())
         {
-            LLFileSystem::removeFile(newAssetId, LLAssetType::AT_NOTECARD);
+            gVFS->removeFile(newAssetId, LLAssetType::AT_NOTECARD);
         }
         nc->setAssetId(newAssetId);
         nc->refreshFromInventory();
@@ -557,13 +558,14 @@ bool LLPreviewNotecard::saveIfNeeded(LLInventoryItem* copyitem, bool sync)
                 tid.generate();
                 asset_id = tid.makeAssetID(gAgent.getSecureSessionID());
 
-                LLFileSystem file(asset_id, LLAssetType::AT_NOTECARD, LLFileSystem::APPEND);
+                LLVFile file(gVFS, asset_id, LLAssetType::AT_NOTECARD, LLVFile::APPEND);
 
 
 				LLSaveNotecardInfo* info = new LLSaveNotecardInfo(this, mItemUUID, mObjectUUID,
 																tid, copyitem);
 
                 S32 size = buffer.length() + 1;
+                file.setMaxSize(size);
                 file.write((U8*)buffer.c_str(), size);
 
 				gAssetStorage->storeAssetData(tid, LLAssetType::AT_NOTECARD,
diff --git a/indra/newview/llpreviewnotecard.h b/indra/newview/llpreviewnotecard.h
index 063a01ca47..d9c14815c1 100644
--- a/indra/newview/llpreviewnotecard.h
+++ b/indra/newview/llpreviewnotecard.h
@@ -83,7 +83,8 @@ protected:
 
 	void deleteNotecard();
 
-	static void onLoadComplete(const LLUUID& asset_uuid,
+	static void onLoadComplete(LLVFS *vfs,
+							   const LLUUID& asset_uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 
diff --git a/indra/newview/llpreviewscript.cpp b/indra/newview/llpreviewscript.cpp
index 379bc9871c..5e81fa6402 100644
--- a/indra/newview/llpreviewscript.cpp
+++ b/indra/newview/llpreviewscript.cpp
@@ -51,7 +51,7 @@
 #include "llsdserialize.h"
 #include "llslider.h"
 #include "lltooldraganddrop.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 
 #include "llagent.h"
 #include "llmenugl.h"
@@ -1685,11 +1685,8 @@ void LLPreviewLSL::saveIfNeeded(bool sync /*= true*/)
         {
             std::string buffer(mScriptEd->mEditor->getText());
 
-            LLUUID old_asset_id = inv_item->getAssetUUID().isNull() ? mScriptEd->getAssetID() : inv_item->getAssetUUID();
-
             LLResourceUploadInfo::ptr_t uploadInfo(std::make_shared<LLScriptAssetUpload>(mItemUUID, buffer, 
-                [old_asset_id](LLUUID itemId, LLUUID, LLUUID, LLSD response) {
-                    LLFileSystem::removeFile(old_asset_id, LLAssetType::AT_LSL_TEXT);
+                [](LLUUID itemId, LLUUID, LLUUID, LLSD response) {
                     LLPreviewLSL::finishedLSLUpload(itemId, response);
                 }));
 
@@ -1699,8 +1696,8 @@ void LLPreviewLSL::saveIfNeeded(bool sync /*= true*/)
 }
 
 // static
-void LLPreviewLSL::onLoadComplete(const LLUUID& asset_uuid, LLAssetType::EType type,
-								  void* user_data, S32 status, LLExtStat ext_status)
+void LLPreviewLSL::onLoadComplete( LLVFS *vfs, const LLUUID& asset_uuid, LLAssetType::EType type,
+								   void* user_data, S32 status, LLExtStat ext_status)
 {
 	LL_DEBUGS() << "LLPreviewLSL::onLoadComplete: got uuid " << asset_uuid
 		 << LL_ENDL;
@@ -1710,7 +1707,7 @@ void LLPreviewLSL::onLoadComplete(const LLUUID& asset_uuid, LLAssetType::EType t
 	{
 		if(0 == status)
 		{
-			LLFileSystem file(asset_uuid, type);
+			LLVFile file(vfs, asset_uuid, type);
 			S32 file_length = file.getSize();
 
 			std::vector<char> buffer(file_length+1);
@@ -1737,7 +1734,6 @@ void LLPreviewLSL::onLoadComplete(const LLUUID& asset_uuid, LLAssetType::EType t
 			}
 			preview->mScriptEd->setScriptName(script_name);
 			preview->mScriptEd->setEnableEditing(is_modifiable);
-            preview->mScriptEd->setAssetID(asset_uuid);
 			preview->mAssetStatus = PREVIEW_ASSET_LOADED;
 		}
 		else
@@ -1974,7 +1970,7 @@ void LLLiveLSLEditor::loadAsset()
 }
 
 // static
-void LLLiveLSLEditor::onLoadComplete(const LLUUID& asset_id,
+void LLLiveLSLEditor::onLoadComplete(LLVFS *vfs, const LLUUID& asset_id,
 									 LLAssetType::EType type,
 									 void* user_data, S32 status, LLExtStat ext_status)
 {
@@ -1988,10 +1984,9 @@ void LLLiveLSLEditor::onLoadComplete(const LLUUID& asset_id,
 	{
 		if( LL_ERR_NOERR == status )
 		{
-			instance->loadScriptText(asset_id, type);
+			instance->loadScriptText(vfs, asset_id, type);
 			instance->mScriptEd->setEnableEditing(TRUE);
 			instance->mAssetStatus = PREVIEW_ASSET_LOADED;
-            instance->mScriptEd->setAssetID(asset_id);
 		}
 		else
 		{
@@ -2015,9 +2010,9 @@ void LLLiveLSLEditor::onLoadComplete(const LLUUID& asset_id,
 	delete floater_key;
 }
 
-void LLLiveLSLEditor::loadScriptText(const LLUUID &uuid, LLAssetType::EType type)
+void LLLiveLSLEditor::loadScriptText(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type)
 {
-	LLFileSystem file(uuid, type);
+	LLVFile file(vfs, uuid, type);
 	S32 file_length = file.getSize();
 	std::vector<char> buffer(file_length + 1);
 	file.read((U8*)&buffer[0], file_length);
@@ -2171,7 +2166,6 @@ void LLLiveLSLEditor::finishLSLUpload(LLUUID itemId, LLUUID taskId, LLUUID newAs
     if (preview)
     {
         preview->mItem->setAssetUUID(newAssetId);
-        preview->mScriptEd->setAssetID(newAssetId);
 
         // Bytecode save completed
         if (response["compiled"])
@@ -2242,14 +2236,12 @@ void LLLiveLSLEditor::saveIfNeeded(bool sync /*= true*/)
     if (!url.empty())
     {
         std::string buffer(mScriptEd->mEditor->getText());
-        LLUUID old_asset_id = mScriptEd->getAssetID();
 
         LLResourceUploadInfo::ptr_t uploadInfo(std::make_shared<LLScriptAssetUpload>(mObjectUUID, mItemUUID, 
                 monoChecked() ? LLScriptAssetUpload::MONO : LLScriptAssetUpload::LSL2, 
                 isRunning, mScriptEd->getAssociatedExperience(), buffer, 
-                [isRunning, old_asset_id](LLUUID itemId, LLUUID taskId, LLUUID newAssetId, LLSD response) { 
-                        LLFileSystem::removeFile(old_asset_id, LLAssetType::AT_LSL_TEXT);
-                        LLLiveLSLEditor::finishLSLUpload(itemId, taskId, newAssetId, response, isRunning);
+                [isRunning](LLUUID itemId, LLUUID taskId, LLUUID newAssetId, LLSD response) { 
+                    LLLiveLSLEditor::finishLSLUpload(itemId, taskId, newAssetId, response, isRunning);
                 }));
 
         LLViewerAssetUpload::EnqueueInventoryUpload(url, uploadInfo);
diff --git a/indra/newview/llpreviewscript.h b/indra/newview/llpreviewscript.h
index 18c10ab365..3cf22a0e6e 100644
--- a/indra/newview/llpreviewscript.h
+++ b/indra/newview/llpreviewscript.h
@@ -48,6 +48,7 @@ struct 	LLEntryAndEdCore;
 class LLMenuBarGL;
 class LLFloaterScriptSearch;
 class LLKeywordToken;
+class LLVFS;
 class LLViewerInventoryItem;
 class LLScriptEdContainer;
 class LLFloaterGotoLine;
@@ -142,9 +143,6 @@ public:
 
 	void 			setItemRemoved(bool script_removed){mScriptRemoved = script_removed;};
 
-    void 			setAssetID( const LLUUID& asset_id){ mAssetID = asset_id; };
-    LLUUID 			getAssetID() { return mAssetID; }
-
 private:
 	void		onBtnDynamicHelp();
 	void		onBtnUndoChanges();
@@ -190,7 +188,6 @@ private:
 	LLUUID			mAssociatedExperience;
 	BOOL			mScriptRemoved;
 	BOOL			mSaveDialogShown;
-    LLUUID          mAssetID;
 
 	LLScriptEdContainer* mContainer; // parent view
 
@@ -237,7 +234,7 @@ protected:
 	static void onLoad(void* userdata);
 	static void onSave(void* userdata, BOOL close_after_save);
 	
-	static void onLoadComplete(const LLUUID& uuid,
+	static void onLoadComplete(LLVFS *vfs, const LLUUID& uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 
@@ -298,13 +295,13 @@ private:
 	static void onLoad(void* userdata);
 	static void onSave(void* userdata, BOOL close_after_save);
 
-	static void onLoadComplete(const LLUUID& asset_uuid,
+	static void onLoadComplete(LLVFS *vfs, const LLUUID& asset_uuid,
 							   LLAssetType::EType type,
 							   void* user_data, S32 status, LLExtStat ext_status);
 	static void onRunningCheckboxClicked(LLUICtrl*, void* userdata);
 	static void onReset(void* userdata);
 
-	void loadScriptText(const LLUUID &uuid, LLAssetType::EType type);
+	void loadScriptText(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type);
 
 	static void onErrorList(LLUICtrl*, void* user_data);
 
diff --git a/indra/newview/llsettingsvo.cpp b/indra/newview/llsettingsvo.cpp
index 58cbe0e20a..1e5b893cbc 100644
--- a/indra/newview/llsettingsvo.cpp
+++ b/indra/newview/llsettingsvo.cpp
@@ -57,7 +57,7 @@
 
 #include "llinventorymodel.h"
 #include "llassetstorage.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "lldrawpoolwater.h"
 
 #include <boost/algorithm/string/replace.hpp>
@@ -292,18 +292,18 @@ void LLSettingsVOBase::onTaskAssetUploadComplete(LLUUID itemId, LLUUID taskId, L
 void LLSettingsVOBase::getSettingsAsset(const LLUUID &assetId, LLSettingsVOBase::asset_download_fn callback)
 {
     gAssetStorage->getAssetData(assetId, LLAssetType::AT_SETTINGS,
-        [callback](const LLUUID &asset_id, LLAssetType::EType, void *, S32 status, LLExtStat ext_status) 
-            { onAssetDownloadComplete(asset_id, status, ext_status, callback); },
+        [callback](LLVFS *vfs, const LLUUID &asset_id, LLAssetType::EType, void *, S32 status, LLExtStat ext_status) 
+            { onAssetDownloadComplete(vfs, asset_id, status, ext_status, callback); },
         nullptr, true);
 
 }
 
-void LLSettingsVOBase::onAssetDownloadComplete(const LLUUID &asset_id, S32 status, LLExtStat ext_status, LLSettingsVOBase::asset_download_fn callback)
+void LLSettingsVOBase::onAssetDownloadComplete(LLVFS *vfs, const LLUUID &asset_id, S32 status, LLExtStat ext_status, LLSettingsVOBase::asset_download_fn callback)
 {
     LLSettingsBase::ptr_t settings;
     if (!status)
     {
-        LLFileSystem file(asset_id, LLAssetType::AT_SETTINGS, LLFileSystem::READ);
+        LLVFile file(vfs, asset_id, LLAssetType::AT_SETTINGS, LLVFile::READ);
         S32 size = file.getSize();
 
         std::string buffer(size + 1, '\0');
diff --git a/indra/newview/llsettingsvo.h b/indra/newview/llsettingsvo.h
index a1baf02fe7..65136ad2f5 100644
--- a/indra/newview/llsettingsvo.h
+++ b/indra/newview/llsettingsvo.h
@@ -38,6 +38,7 @@
 #include "llextendedstatus.h"
 #include <boost/signals2.hpp>
 
+class LLVFS;
 class LLInventoryItem;
 class LLGLSLShader;
 
@@ -80,7 +81,7 @@ private:
     static void     onAgentAssetUploadComplete(LLUUID itemId, LLUUID newAssetId, LLUUID newItemId, LLSD response, LLSettingsBase::ptr_t psettings, inventory_result_fn callback);
     static void     onTaskAssetUploadComplete(LLUUID itemId, LLUUID taskId, LLUUID newAssetId, LLSD response, LLSettingsBase::ptr_t psettings, inventory_result_fn callback);
     
-    static void     onAssetDownloadComplete(const LLUUID &asset_id, S32 status, LLExtStat ext_status, asset_download_fn callback);
+    static void     onAssetDownloadComplete(LLVFS *vfs, const LLUUID &asset_id, S32 status, LLExtStat ext_status, asset_download_fn callback);
 };
 
 //=========================================================================
diff --git a/indra/newview/llsnapshotlivepreview.cpp b/indra/newview/llsnapshotlivepreview.cpp
index 8134187c21..8369def968 100644
--- a/indra/newview/llsnapshotlivepreview.cpp
+++ b/indra/newview/llsnapshotlivepreview.cpp
@@ -31,7 +31,6 @@
 #include "llagentbenefits.h"
 #include "llagentcamera.h"
 #include "llagentui.h"
-#include "llfilesystem.h"
 #include "llcombobox.h"
 #include "llfloaterperms.h"
 #include "llfloaterreg.h"
@@ -51,6 +50,8 @@
 #include "llviewercontrol.h"
 #include "llviewermenufile.h"	// upload_new_resource()
 #include "llviewerstats.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llwindow.h"
 #include "llworld.h"
 #include <boost/filesystem.hpp>
@@ -1005,8 +1006,7 @@ void LLSnapshotLivePreview::saveTexture(BOOL outfit_snapshot, std::string name)
 
 	if (formatted->encode(scaled, 0.0f))
 	{
-        LLFileSystem fmt_file(new_asset_id, LLAssetType::AT_TEXTURE, LLFileSystem::WRITE);
-        fmt_file.write(formatted->getData(), formatted->getDataSize());
+		LLVFile::writeFile(formatted->getData(), formatted->getDataSize(), gVFS, new_asset_id, LLAssetType::AT_TEXTURE);
 		std::string pos_string;
 		LLAgentUI::buildLocationString(pos_string, LLAgentUI::LOCATION_FORMAT_FULL);
 		std::string who_took_it;
diff --git a/indra/newview/llstartup.cpp b/indra/newview/llstartup.cpp
index f281b30a8e..17777c3ceb 100644
--- a/indra/newview/llstartup.cpp
+++ b/indra/newview/llstartup.cpp
@@ -82,6 +82,7 @@
 #include "llversioninfo.h"
 #include "llviewercontrol.h"
 #include "llviewerhelp.h"
+#include "llvfs.h"
 #include "llxorcipher.h"	// saved password, MAC address
 #include "llwindow.h"
 #include "message.h"
@@ -267,7 +268,7 @@ bool login_alert_status(const LLSD& notification, const LLSD& response);
 void login_packet_failed(void**, S32 result);
 void use_circuit_callback(void**, S32 result);
 void register_viewer_callbacks(LLMessageSystem* msg);
-void asset_callback_nothing(const LLUUID&, LLAssetType::EType, void*, S32);
+void asset_callback_nothing(LLVFS*, const LLUUID&, LLAssetType::EType, void*, S32);
 bool callback_choose_gender(const LLSD& notification, const LLSD& response);
 void init_start_screen(S32 location_id);
 void release_start_screen();
@@ -579,7 +580,7 @@ bool idle_startup()
 			// start the xfer system. by default, choke the downloads
 			// a lot...
 			const S32 VIEWER_MAX_XFER = 3;
-			start_xfer_manager();
+			start_xfer_manager(gVFS);
 			gXferManager->setMaxIncomingXfers(VIEWER_MAX_XFER);
 			F32 xfer_throttle_bps = gSavedSettings.getF32("XferThrottle");
 			if (xfer_throttle_bps > 1.f)
@@ -587,7 +588,7 @@ bool idle_startup()
 				gXferManager->setUseAckThrottling(TRUE);
 				gXferManager->setAckThrottleBPS(xfer_throttle_bps);
 			}
-			gAssetStorage = new LLViewerAssetStorage(msg, gXferManager);
+			gAssetStorage = new LLViewerAssetStorage(msg, gXferManager, gVFS, gStaticVFS);
 
 
 			F32 dropPercent = gSavedSettings.getF32("PacketDropPercentage");
@@ -1003,6 +1004,13 @@ bool idle_startup()
 
 		gViewerWindow->revealIntroPanel();
 
+		// Poke the VFS, which could potentially block for a while if
+		// Windows XP is acting up
+		set_startup_status(0.07f, LLTrans::getString("LoginVerifyingCache"), LLStringUtil::null);
+		display_startup();
+
+		gVFS->pokeFiles();
+
 		LLStartUp::setStartupState( STATE_LOGIN_AUTH_INIT );
 
 		return FALSE;
@@ -2581,7 +2589,7 @@ void register_viewer_callbacks(LLMessageSystem* msg)
 	msg->setHandlerFuncFast(_PREHASH_FeatureDisabled, process_feature_disabled_message);
 }
 
-void asset_callback_nothing(const LLUUID&, LLAssetType::EType, void*, S32)
+void asset_callback_nothing(LLVFS*, const LLUUID&, LLAssetType::EType, void*, S32)
 {
 	// nothing
 }
diff --git a/indra/newview/lltexturecache.cpp b/indra/newview/lltexturecache.cpp
index d4fc6f3de2..a9f19dc32d 100644
--- a/indra/newview/lltexturecache.cpp
+++ b/indra/newview/lltexturecache.cpp
@@ -55,7 +55,6 @@ const S32 TEXTURE_FAST_CACHE_ENTRY_OVERHEAD = sizeof(S32) * 4; //w, h, c, level
 const S32 TEXTURE_FAST_CACHE_DATA_SIZE = 16 * 16 * 4;
 const S32 TEXTURE_FAST_CACHE_ENTRY_SIZE = TEXTURE_FAST_CACHE_DATA_SIZE + TEXTURE_FAST_CACHE_ENTRY_OVERHEAD;
 const F32 TEXTURE_LAZY_PURGE_TIME_LIMIT = .004f; // 4ms. Would be better to autoadjust, but there is a major cache rework in progress.
-const F32 TEXTURE_PRUNING_MAX_TIME = 15.f;
 
 class LLTextureCacheWorker : public LLWorkerClass
 {
@@ -1552,6 +1551,7 @@ void LLTextureCache::readHeaderCache()
 			if (num_entries - empty_entries > sCacheMaxEntries)
 			{
 				// Special case: cache size was reduced, need to remove entries
+				// Note: After we prune entries, we will call this again and create the LRU
 				U32 entries_to_purge = (num_entries - empty_entries) - sCacheMaxEntries;
 				LL_INFOS() << "Texture Cache Entries: " << num_entries << " Max: " << sCacheMaxEntries << " Empty: " << empty_entries << " Purging: " << entries_to_purge << LL_ENDL;
 				// We can exit the following loop with the given condition, since if we'd reach the end of the lru set we'd have:
@@ -1564,7 +1564,7 @@ void LLTextureCache::readHeaderCache()
 					++iter;
 				}
 			}
-
+			else
 			{
 				S32 lru_entries = (S32)((F32)sCacheMaxEntries * TEXTURE_CACHE_LRU_SIZE);
 				for (std::set<lru_data_t>::iterator iter = lru.begin(); iter != lru.end(); ++iter)
@@ -1578,19 +1578,30 @@ void LLTextureCache::readHeaderCache()
 			
 			if (purge_list.size() > 0)
 			{
-				LLTimer timer;
 				for (std::set<U32>::iterator iter = purge_list.begin(); iter != purge_list.end(); ++iter)
 				{
 					std::string tex_filename = getTextureFileName(entries[*iter].mID);
 					removeEntry((S32)*iter, entries[*iter], tex_filename);
-
-					//make sure that pruning entries doesn't take too much time
-					if (timer.getElapsedTimeF32() > TEXTURE_PRUNING_MAX_TIME)
+				}
+				// If we removed any entries, we need to rebuild the entries list,
+				// write the header, and call this again
+				std::vector<Entry> new_entries;
+				for (U32 i=0; i<num_entries; i++)
+				{
+					const Entry& entry = entries[i];
+					if (entry.mImageSize > 0)
 					{
-						break;
+						new_entries.push_back(entry);
 					}
 				}
-				writeEntriesAndClose(entries);
+                mFreeList.clear(); // recreating list, no longer valid.
+				llassert_always(new_entries.size() <= sCacheMaxEntries);
+				mHeaderEntriesInfo.mEntries = new_entries.size();
+				writeEntriesHeader();
+				writeEntriesAndClose(new_entries);
+				mHeaderMutex.unlock(); // unlock the mutex before calling again
+				readHeaderCache(); // repeat with new entries file
+				mHeaderMutex.lock();
 			}
 			else
 			{
@@ -1713,7 +1724,7 @@ void LLTextureCache::purgeTexturesLazy(F32 time_limit_sec)
 		}
 
 		S64 cache_size = mTexturesSizeTotal;
-		S64 purged_cache_size = (llmax(cache_size, sCacheMaxTexturesSize) * (S64)((1.f - TEXTURE_CACHE_PURGE_AMOUNT) * 100)) / 100;
+		S64 purged_cache_size = (sCacheMaxTexturesSize * (S64)((1.f - TEXTURE_CACHE_PURGE_AMOUNT) * 100)) / 100;
 		for (time_idx_set_t::iterator iter = time_idx_set.begin();
 			iter != time_idx_set.end(); ++iter)
 		{
@@ -1809,26 +1820,21 @@ void LLTextureCache::purgeTextures(bool validate)
 	}
 
 	S64 cache_size = mTexturesSizeTotal;
-	S64 purged_cache_size = (llmax(cache_size, sCacheMaxTexturesSize) * (S64)((1.f - TEXTURE_CACHE_PURGE_AMOUNT) * 100)) / 100;
+	S64 purged_cache_size = (sCacheMaxTexturesSize * (S64)((1.f-TEXTURE_CACHE_PURGE_AMOUNT)*100)) / 100;
 	S32 purge_count = 0;
 	for (time_idx_set_t::iterator iter = time_idx_set.begin();
 		 iter != time_idx_set.end(); ++iter)
 	{
 		S32 idx = iter->second;
 		bool purge_entry = false;		
-
-		if (cache_size >= purged_cache_size)
-		{
-			purge_entry = true;
-		}
-		else if (validate)
+        if (validate)
 		{
 			// make sure file exists and is the correct size
 			U32 uuididx = entries[idx].mID.mData[0];
 			if (uuididx == validate_idx)
 			{
-				std::string filename = getTextureFileName(entries[idx].mID);
-				LL_DEBUGS("TextureCache") << "Validating: " << filename << "Size: " << entries[idx].mBodySize << LL_ENDL;
+                std::string filename = getTextureFileName(entries[idx].mID);
+ 				LL_DEBUGS("TextureCache") << "Validating: " << filename << "Size: " << entries[idx].mBodySize << LL_ENDL;
 				// mHeaderAPRFilePoolp because this is under header mutex in main thread
 				S32 bodysize = LLAPRFile::size(filename, mHeaderAPRFilePoolp);
 				if (bodysize != entries[idx].mBodySize)
@@ -1838,6 +1844,10 @@ void LLTextureCache::purgeTextures(bool validate)
 				}
 			}
 		}
+		else if (cache_size >= purged_cache_size)
+		{
+			purge_entry = true;
+		}
 		else
 		{
 			break;
diff --git a/indra/newview/llviewerassetstorage.cpp b/indra/newview/llviewerassetstorage.cpp
index 5b76d57196..54f80a2995 100644
--- a/indra/newview/llviewerassetstorage.cpp
+++ b/indra/newview/llviewerassetstorage.cpp
@@ -28,7 +28,8 @@
 
 #include "llviewerassetstorage.h"
 
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "message.h"
 
 #include "llagent.h"
@@ -103,8 +104,10 @@ public:
 ///----------------------------------------------------------------------------
 
 // Unused?
-LLViewerAssetStorage::LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer, const LLHost &upstream_host)
-    : LLAssetStorage(msg, xfer, upstream_host),
+LLViewerAssetStorage::LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+                                           LLVFS *vfs, LLVFS *static_vfs, 
+                                           const LLHost &upstream_host)
+    : LLAssetStorage(msg, xfer, vfs, static_vfs, upstream_host),
       mAssetCoroCount(0),
       mCountRequests(0),
       mCountStarted(0),
@@ -114,8 +117,10 @@ LLViewerAssetStorage::LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *
 {
 }
 
-LLViewerAssetStorage::LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer)
-    : LLAssetStorage(msg, xfer),
+
+LLViewerAssetStorage::LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+                                           LLVFS *vfs, LLVFS *static_vfs)
+    : LLAssetStorage(msg, xfer, vfs, static_vfs),
       mAssetCoroCount(0),
       mCountRequests(0),
       mCountStarted(0),
@@ -152,13 +157,13 @@ void LLViewerAssetStorage::storeAssetData(
     
     if (mUpstreamHost.isOk())
     {
-        if (LLFileSystem::getExists(asset_id, asset_type))
+        if (mVFS->getExists(asset_id, asset_type))
         {
             // Pack data into this packet if we can fit it.
             U8 buffer[MTUBYTES];
             buffer[0] = 0;
 
-            LLFileSystem vfile(asset_id, asset_type, LLFileSystem::READ);
+            LLVFile vfile(mVFS, asset_id, asset_type, LLVFile::READ);
             S32 asset_size = vfile.getSize();
 
             LLAssetRequest *req = new LLAssetRequest(asset_id, asset_type);
@@ -167,20 +172,22 @@ void LLViewerAssetStorage::storeAssetData(
 
             if (asset_size < 1)
             {
-                // This can happen if there's a bug in our code or if the cache has been corrupted.
-                LL_WARNS("AssetStorage") << "LLViewerAssetStorage::storeAssetData()  Data _should_ already be in the cache, but it's not! " << asset_id << LL_ENDL;
+                // This can happen if there's a bug in our code or if the VFS has been corrupted.
+                LL_WARNS("AssetStorage") << "LLViewerAssetStorage::storeAssetData()  Data _should_ already be in the VFS, but it's not! " << asset_id << LL_ENDL;
+                // LLAssetStorage metric: Zero size VFS
+                reportMetric( asset_id, asset_type, LLStringUtil::null, LLUUID::null, 0, MR_ZERO_SIZE, __FILE__, __LINE__, "The file didn't exist or was zero length (VFS - can't tell which)" );
 
                 delete req;
                 if (callback)
                 {
-                    callback(asset_id, user_data, LL_ERR_ASSET_REQUEST_FAILED, LLExtStat::CACHE_CORRUPT);
+                    callback(asset_id, user_data, LL_ERR_ASSET_REQUEST_FAILED, LLExtStat::VFS_CORRUPT);
                 }
                 return;
             }
             else
             {
                 // LLAssetStorage metric: Successful Request
-                S32 size = LLFileSystem::getFileSize(asset_id, asset_type);
+                S32 size = mVFS->getSize(asset_id, asset_type);
                 const char *message = "Added to upload queue";
                 reportMetric( asset_id, asset_type, LLStringUtil::null, LLUUID::null, size, MR_OKAY, __FILE__, __LINE__, message );
 
@@ -194,7 +201,7 @@ void LLViewerAssetStorage::storeAssetData(
                 }
             }
 
-            // Read the data from the cache if it'll fit in this packet.
+            // Read the data from the VFS if it'll fit in this packet.
             if (asset_size + 100 < MTUBYTES)
             {
                 BOOL res = vfile.read(buffer, asset_size);      /* Flawfinder: ignore */
@@ -207,11 +214,14 @@ void LLViewerAssetStorage::storeAssetData(
                 }
                 else
                 {
-                    LL_WARNS("AssetStorage") << "Probable corruption in cache file, aborting store asset data" << LL_ENDL;
+                    LL_WARNS("AssetStorage") << "Probable corruption in VFS file, aborting store asset data" << LL_ENDL;
+
+                    // LLAssetStorage metric: VFS corrupt - bogus size
+                    reportMetric( asset_id, asset_type, LLStringUtil::null, LLUUID::null, asset_size, MR_VFS_CORRUPTION, __FILE__, __LINE__, "VFS corruption" );
 
                     if (callback)
                     {
-                        callback(asset_id, user_data, LL_ERR_ASSET_REQUEST_NONEXISTENT_FILE, LLExtStat::CACHE_CORRUPT);
+                        callback(asset_id, user_data, LL_ERR_ASSET_REQUEST_NONEXISTENT_FILE, LLExtStat::VFS_CORRUPT);
                     }
                     return;
                 }
@@ -234,7 +244,8 @@ void LLViewerAssetStorage::storeAssetData(
         else
         {
             LL_WARNS("AssetStorage") << "AssetStorage: attempt to upload non-existent vfile " << asset_id << ":" << LLAssetType::lookup(asset_type) << LL_ENDL;
-            reportMetric( asset_id, asset_type, LLStringUtil::null, LLUUID::null, 0, MR_ZERO_SIZE, __FILE__, __LINE__, "The file didn't exist or was zero length (cache - can't tell which)" );
+            // LLAssetStorage metric: Zero size VFS
+            reportMetric( asset_id, asset_type, LLStringUtil::null, LLUUID::null, 0, MR_ZERO_SIZE, __FILE__, __LINE__, "The file didn't exist or was zero length (VFS - can't tell which)" );
             if (callback)
             {
                 callback(asset_id, user_data,  LL_ERR_ASSET_REQUEST_NONEXISTENT_FILE, LLExtStat::NONEXISTENT_FILE);
@@ -267,6 +278,7 @@ void LLViewerAssetStorage::storeAssetData(
     if(filename.empty())
     {
         // LLAssetStorage metric: no filename
+        reportMetric( LLUUID::null, asset_type, LLStringUtil::null, LLUUID::null, 0, MR_VFS_CORRUPTION, __FILE__, __LINE__, "Filename missing" );
         LL_ERRS() << "No filename specified" << LL_ENDL;
         return;
     }
@@ -291,7 +303,9 @@ void LLViewerAssetStorage::storeAssetData(
         legacy->mUpCallback = callback;
         legacy->mUserData = user_data;
 
-        LLFileSystem file(asset_id, asset_type, LLFileSystem::WRITE);
+        LLVFile file(mVFS, asset_id, asset_type, LLVFile::WRITE);
+
+        file.setMaxSize(size);
 
         const S32 buf_size = 65536;
         U8 copy_buf[buf_size];
@@ -525,20 +539,21 @@ void LLViewerAssetStorage::assetRequestCoro(
 			// case.
             LLUUID temp_id;
             temp_id.generate();
-            LLFileSystem vf(temp_id, atype, LLFileSystem::WRITE);
+            LLVFile vf(gAssetStorage->mVFS, temp_id, atype, LLVFile::WRITE);
+            vf.setMaxSize(size);
             req->mBytesFetched = size;
             if (!vf.write(raw.data(),size))
             {
                 // TODO asset-http: handle error
                 LL_WARNS("ViewerAsset") << "Failure in vf.write()" << LL_ENDL;
                 result_code = LL_ERR_ASSET_REQUEST_FAILED;
-                ext_status = LLExtStat::CACHE_CORRUPT;
+                ext_status = LLExtStat::VFS_CORRUPT;
             }
             else if (!vf.rename(uuid, atype))
             {
                 LL_WARNS("ViewerAsset") << "rename failed" << LL_ENDL;
                 result_code = LL_ERR_ASSET_REQUEST_FAILED;
-                ext_status = LLExtStat::CACHE_CORRUPT;
+                ext_status = LLExtStat::VFS_CORRUPT;
             }
             else
             {
diff --git a/indra/newview/llviewerassetstorage.h b/indra/newview/llviewerassetstorage.h
index 972c89de34..ef01d179b7 100644
--- a/indra/newview/llviewerassetstorage.h
+++ b/indra/newview/llviewerassetstorage.h
@@ -30,16 +30,18 @@
 #include "llassetstorage.h"
 #include "llcorehttputil.h"
 
-class LLFileSystem;
+class LLVFile;
 
 class LLViewerAssetRequest;
 
 class LLViewerAssetStorage : public LLAssetStorage
 {
 public:
-	LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer, const LLHost &upstream_host);
+	LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+				   LLVFS *vfs, LLVFS *static_vfs, const LLHost &upstream_host);
 
-	LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer);
+	LLViewerAssetStorage(LLMessageSystem *msg, LLXferManager *xfer,
+				   LLVFS *vfs, LLVFS *static_vfs);
 
 	~LLViewerAssetStorage();
 
diff --git a/indra/newview/llviewerassetupload.cpp b/indra/newview/llviewerassetupload.cpp
index 1923e7d6ff..bc07821ccd 100644
--- a/indra/newview/llviewerassetupload.cpp
+++ b/indra/newview/llviewerassetupload.cpp
@@ -45,7 +45,7 @@
 #include "llviewerassetupload.h"
 #include "llappviewer.h"
 #include "llviewerstats.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
 #include "llgesturemgr.h"
 #include "llpreviewnotecard.h"
 #include "llpreviewgesture.h"
@@ -467,13 +467,15 @@ LLSD LLNewFileResourceUploadInfo::exportTempFile()
 
     setAssetType(assetType);
 
-    // copy this file into the cache for upload
+    // copy this file into the vfs for upload
     S32 file_size;
     LLAPRFile infile;
     infile.open(filename, LL_APR_RB, NULL, &file_size);
     if (infile.getFileHandle())
     {
-        LLFileSystem file(getAssetId(), assetType, LLFileSystem::WRITE);
+        LLVFile file(gVFS, getAssetId(), assetType, LLVFile::WRITE);
+
+        file.setMaxSize(file_size);
 
         const S32 buf_size = 65536;
         U8 copy_buf[buf_size];
@@ -505,7 +507,7 @@ LLBufferedAssetUploadInfo::LLBufferedAssetUploadInfo(LLUUID itemId, LLAssetType:
     mContents(buffer),
     mInvnFinishFn(finish),
     mTaskFinishFn(nullptr),
-    mStoredToCache(false)
+    mStoredToVFS(false)
 {
     setItemId(itemId);
     setAssetType(assetType);
@@ -519,7 +521,7 @@ LLBufferedAssetUploadInfo::LLBufferedAssetUploadInfo(LLUUID itemId, LLPointer<LL
     mContents(),
     mInvnFinishFn(finish),
     mTaskFinishFn(nullptr),
-    mStoredToCache(false)
+    mStoredToVFS(false)
 {
     setItemId(itemId);
 
@@ -553,7 +555,7 @@ LLBufferedAssetUploadInfo::LLBufferedAssetUploadInfo(LLUUID taskId, LLUUID itemI
     mContents(buffer),
     mInvnFinishFn(nullptr),
     mTaskFinishFn(finish),
-    mStoredToCache(false)
+    mStoredToVFS(false)
 {
     setItemId(itemId);
     setAssetType(assetType);
@@ -564,12 +566,13 @@ LLSD LLBufferedAssetUploadInfo::prepareUpload()
     if (getAssetId().isNull())
         generateNewAssetId();
 
-    LLFileSystem file(getAssetId(), getAssetType(), LLFileSystem::APPEND);
+    LLVFile file(gVFS, getAssetId(), getAssetType(), LLVFile::APPEND);
 
     S32 size = mContents.length() + 1;
+    file.setMaxSize(size);
     file.write((U8*)mContents.c_str(), size);
 
-    mStoredToCache = true;
+    mStoredToVFS = true;
 
     return LLSD().with("success", LLSD::Boolean(true));
 }
@@ -592,10 +595,10 @@ LLUUID LLBufferedAssetUploadInfo::finishUpload(LLSD &result)
     LLUUID newAssetId = result["new_asset"].asUUID();
     LLUUID itemId = getItemId();
 
-    if (mStoredToCache)
+    if (mStoredToVFS)
     {
         LLAssetType::EType assetType(getAssetType());
-        LLFileSystem::renameFile(getAssetId(), assetType, newAssetId, assetType);
+        gVFS->renameFile(getAssetId(), assetType, newAssetId, assetType);
     }
 
     if (mTaskUpload)
diff --git a/indra/newview/llviewerassetupload.h b/indra/newview/llviewerassetupload.h
index e56ba7d8f7..d9eacf3167 100644
--- a/indra/newview/llviewerassetupload.h
+++ b/indra/newview/llviewerassetupload.h
@@ -197,7 +197,7 @@ private:
     std::string         mContents;
     invnUploadFinish_f  mInvnFinishFn;
     taskUploadFinish_f  mTaskFinishFn;
-    bool                mStoredToCache;
+    bool                mStoredToVFS;
 };
 
 //-------------------------------------------------------------------------
diff --git a/indra/newview/llviewermedia_streamingaudio.cpp b/indra/newview/llviewermedia_streamingaudio.cpp
index d3e24aece5..3ccf3070ab 100644
--- a/indra/newview/llviewermedia_streamingaudio.cpp
+++ b/indra/newview/llviewermedia_streamingaudio.cpp
@@ -33,8 +33,10 @@
 #include "llviewermedia_streamingaudio.h"
 
 #include "llmimetypes.h"
+#include "llvfs.h"
 #include "lldir.h"
 
+
 LLStreamingAudio_MediaPlugins::LLStreamingAudio_MediaPlugins() :
 	mMediaPlugin(NULL),
 	mGain(1.0)
diff --git a/indra/newview/llviewermenufile.cpp b/indra/newview/llviewermenufile.cpp
index e59a263adc..4b231c7067 100644
--- a/indra/newview/llviewermenufile.cpp
+++ b/indra/newview/llviewermenufile.cpp
@@ -53,6 +53,8 @@
 #include "llviewercontrol.h"	// gSavedSettings
 #include "llviewertexturelist.h"
 #include "lluictrlfactory.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llviewerinventory.h"
 #include "llviewermenu.h"	// gMenuHolder
 #include "llviewerparcelmgr.h"
diff --git a/indra/newview/llviewermessage.cpp b/indra/newview/llviewermessage.cpp
index 6ef452bd92..458fc3b13d 100644
--- a/indra/newview/llviewermessage.cpp
+++ b/indra/newview/llviewermessage.cpp
@@ -44,7 +44,8 @@
 #include "llteleportflags.h"
 #include "lltoastnotifypanel.h"
 #include "lltransactionflags.h"
-#include "llfilesystem.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llxfermanager.h"
 #include "mean_collision_data.h"
 
@@ -6843,15 +6844,16 @@ void process_covenant_reply(LLMessageSystem* msg, void**)
 	}
 }
 
-void onCovenantLoadComplete(const LLUUID& asset_uuid,
-							LLAssetType::EType type,
-							void* user_data, S32 status, LLExtStat ext_status)
+void onCovenantLoadComplete(LLVFS *vfs,
+					const LLUUID& asset_uuid,
+					LLAssetType::EType type,
+					void* user_data, S32 status, LLExtStat ext_status)
 {
 	LL_DEBUGS("Messaging") << "onCovenantLoadComplete()" << LL_ENDL;
 	std::string covenant_text;
 	if(0 == status)
 	{
-		LLFileSystem file(asset_uuid, type, LLFileSystem::READ);
+		LLVFile file(vfs, asset_uuid, type, LLVFile::READ);
 		
 		S32 file_length = file.getSize();
 		
diff --git a/indra/newview/llviewermessage.h b/indra/newview/llviewermessage.h
index 1e5a69ae13..78829a6a56 100644
--- a/indra/newview/llviewermessage.h
+++ b/indra/newview/llviewermessage.h
@@ -47,6 +47,7 @@ class LLInventoryObject;
 class LLInventoryItem;
 class LLMeanCollisionData;
 class LLMessageSystem;
+class LLVFS;
 class LLViewerObject;
 class LLViewerRegion;
 
@@ -188,7 +189,8 @@ void process_script_dialog(LLMessageSystem* msg, void**);
 void process_load_url(LLMessageSystem* msg, void**);
 void process_script_teleport_request(LLMessageSystem* msg, void**);
 void process_covenant_reply(LLMessageSystem* msg, void**);
-void onCovenantLoadComplete(const LLUUID& asset_uuid,
+void onCovenantLoadComplete(LLVFS *vfs,
+							const LLUUID& asset_uuid,
 							LLAssetType::EType type,
 							void* user_data, S32 status, LLExtStat ext_status);
 
diff --git a/indra/newview/llviewerprecompiledheaders.h b/indra/newview/llviewerprecompiledheaders.h
index e378c2448a..bbbacce8fa 100644
--- a/indra/newview/llviewerprecompiledheaders.h
+++ b/indra/newview/llviewerprecompiledheaders.h
@@ -101,6 +101,7 @@
 #include "v4math.h"
 #include "xform.h"
 
+// Library includes from llvfs
 #include "lldir.h"
 
 // Library includes from llmessage project
diff --git a/indra/newview/llviewerstats.cpp b/indra/newview/llviewerstats.cpp
index 35fb4de5a9..05f88b0a75 100644
--- a/indra/newview/llviewerstats.cpp
+++ b/indra/newview/llviewerstats.cpp
@@ -33,6 +33,7 @@
 #include "llfloaterreg.h"
 #include "llmemory.h"
 #include "lltimer.h"
+#include "llvfile.h"
 
 #include "llappviewer.h"
 
@@ -144,6 +145,7 @@ LLTrace::SampleStatHandle<>	FPS_SAMPLE("fpssample"),
 							VISIBLE_AVATARS("visibleavatars", "Visible Avatars"),
 							SHADER_OBJECTS("shaderobjects", "Object Shaders"),
 							DRAW_DISTANCE("drawdistance", "Draw Distance"),
+							PENDING_VFS_OPERATIONS("vfspendingoperations"),
 							WINDOW_WIDTH("windowwidth", "Window width"),
 							WINDOW_HEIGHT("windowheight", "Window height");
 
@@ -381,6 +383,7 @@ void update_statistics()
 	F64Bits layer_bits = gVLManager.getLandBits() + gVLManager.getWindBits() + gVLManager.getCloudBits();
 	add(LLStatViewer::LAYERS_NETWORK_DATA_RECEIVED, layer_bits);
 	add(LLStatViewer::OBJECT_NETWORK_DATA_RECEIVED, gObjectData);
+	sample(LLStatViewer::PENDING_VFS_OPERATIONS, LLVFile::getVFSThread()->getPending());
 	add(LLStatViewer::ASSET_UDP_DATA_RECEIVED, F64Bits(gTransferManager.getTransferBitsIn(LLTCT_ASSET)));
 	gTransferManager.resetTransferBitsIn(LLTCT_ASSET);
 
diff --git a/indra/newview/llviewerstats.h b/indra/newview/llviewerstats.h
index 72ce336664..04870e0c26 100644
--- a/indra/newview/llviewerstats.h
+++ b/indra/newview/llviewerstats.h
@@ -186,6 +186,7 @@ extern LLTrace::SampleStatHandle<>		FPS_SAMPLE,
 										VISIBLE_AVATARS,
 										SHADER_OBJECTS,
 										DRAW_DISTANCE,
+										PENDING_VFS_OPERATIONS,
 										WINDOW_WIDTH,
 										WINDOW_HEIGHT;
 
diff --git a/indra/newview/llviewertexlayer.cpp b/indra/newview/llviewertexlayer.cpp
index 4c2fbcf837..c501dd0035 100644
--- a/indra/newview/llviewertexlayer.cpp
+++ b/indra/newview/llviewertexlayer.cpp
@@ -31,6 +31,8 @@
 #include "llagent.h"
 #include "llimagej2c.h"
 #include "llnotificationsutil.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "llviewerregion.h"
 #include "llglslshader.h"
 #include "llvoavatarself.h"
diff --git a/indra/newview/llviewertexture.cpp b/indra/newview/llviewertexture.cpp
index d69ab1b110..20a22ba45e 100644
--- a/indra/newview/llviewertexture.cpp
+++ b/indra/newview/llviewertexture.cpp
@@ -39,6 +39,8 @@
 #include "llimagej2c.h"
 #include "llimagetga.h"
 #include "llstl.h"
+#include "llvfile.h"
+#include "llvfs.h"
 #include "message.h"
 #include "lltimer.h"
 
diff --git a/indra/newview/llviewertexture.h b/indra/newview/llviewertexture.h
index 07997e02a5..69568cc825 100644
--- a/indra/newview/llviewertexture.h
+++ b/indra/newview/llviewertexture.h
@@ -54,7 +54,7 @@ class LLTexturePipelineTester ;
 
 typedef	void	(*loaded_callback_func)( BOOL success, LLViewerFetchedTexture *src_vi, LLImageRaw* src, LLImageRaw* src_aux, S32 discard_level, BOOL final, void* userdata );
 
-class LLFileSystem;
+class LLVFile;
 class LLMessageSystem;
 class LLViewerMediaImpl ;
 class LLVOVolume ;
diff --git a/indra/newview/llviewertexturelist.cpp b/indra/newview/llviewertexturelist.cpp
index 38fccba169..561319ca5d 100644
--- a/indra/newview/llviewertexturelist.cpp
+++ b/indra/newview/llviewertexturelist.cpp
@@ -41,7 +41,9 @@
 
 #include "llsdserialize.h"
 #include "llsys.h"
-#include "llfilesystem.h"
+#include "llvfs.h"
+#include "llvfile.h"
+#include "llvfsthread.h"
 #include "llxmltree.h"
 #include "message.h"
 
diff --git a/indra/newview/llviewerwearable.cpp b/indra/newview/llviewerwearable.cpp
index 9a4607bb60..9c4dfd1ca2 100644
--- a/indra/newview/llviewerwearable.cpp
+++ b/indra/newview/llviewerwearable.cpp
@@ -107,6 +107,7 @@ LLWearable::EImportResult LLViewerWearable::importStream( std::istream& input_st
 		// Shouldn't really log the asset id for security reasons, but
 		// we need it in this case.
 		LL_WARNS() << "Bad Wearable asset header: " << mAssetID << LL_ENDL;
+		//gVFS->dumpMap();
 		return result;
 	}
 
diff --git a/indra/newview/llvoavatar.cpp b/indra/newview/llvoavatar.cpp
index 414a1da4fe..f69b9b3861 100644
--- a/indra/newview/llvoavatar.cpp
+++ b/indra/newview/llvoavatar.cpp
@@ -1140,6 +1140,7 @@ void LLVOAvatar::initInstance()
 	//-------------------------------------------------------------------------
 	if (LLCharacter::sInstances.size() == 1)
 	{
+		LLKeyframeMotion::setVFS(gStaticVFS);
 		registerMotion( ANIM_AGENT_DO_NOT_DISTURB,					LLNullMotion::create );
 		registerMotion( ANIM_AGENT_CROUCH,					LLKeyframeStandMotion::create );
 		registerMotion( ANIM_AGENT_CROUCHWALK,				LLKeyframeWalkMotion::create );
diff --git a/indra/newview/llvovolume.h b/indra/newview/llvovolume.h
index 73eeec813c..ce400a3498 100644
--- a/indra/newview/llvovolume.h
+++ b/indra/newview/llvovolume.h
@@ -218,9 +218,10 @@ public:
 				void	updateSculptTexture();
 				void    setIndexInTex(U32 ch, S32 index) { mIndexInTex[ch] = index ;}
 				void	sculpt();
-	 static     void    rebuildMeshAssetCallback(const LLUUID& asset_uuid,
-												 LLAssetType::EType type,
-												 void* user_data, S32 status, LLExtStat ext_status);
+	 static     void    rebuildMeshAssetCallback(LLVFS *vfs,
+														  const LLUUID& asset_uuid,
+														  LLAssetType::EType type,
+														  void* user_data, S32 status, LLExtStat ext_status);
 					
 				void	updateRelativeXform(bool force_identity = false);
 	/*virtual*/ BOOL	updateGeometry(LLDrawable *drawable);
diff --git a/indra/newview/skins/default/xui/da/floater_stats.xml b/indra/newview/skins/default/xui/da/floater_stats.xml
index d07f9e48ca..fe3fa9626e 100644
--- a/indra/newview/skins/default/xui/da/floater_stats.xml
+++ b/indra/newview/skins/default/xui/da/floater_stats.xml
@@ -32,6 +32,7 @@
 					<stat_bar label="Layers" name="layerskbitstat"/>
 					<stat_bar label="Actual In" name="actualinkbitstat"/>
 					<stat_bar label="Actual Out" name="actualoutkbitstat"/>
+					<stat_bar label="VFS Pending Ops" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulator" name="sim">
diff --git a/indra/newview/skins/default/xui/da/strings.xml b/indra/newview/skins/default/xui/da/strings.xml
index 814305c1bc..ec6ba4800d 100644
--- a/indra/newview/skins/default/xui/da/strings.xml
+++ b/indra/newview/skins/default/xui/da/strings.xml
@@ -22,6 +22,9 @@
 	<string name="StartupInitializingTextureCache">
 		Initialiserer tekstur cache...
 	</string>
+	<string name="StartupInitializingVFS">
+		Initialiserer VFS...
+	</string>
 	<string name="ProgressRestoring">
 		Gendanner...
 	</string>
diff --git a/indra/newview/skins/default/xui/de/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/de/floater_scene_load_stats.xml
index a3749f1cfa..dff462a594 100644
--- a/indra/newview/skins/default/xui/de/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/de/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Ebenen" name="layersdatareceived"/>
 					<stat_bar label="Tatsächlicher Eingang" name="messagedatain"/>
 					<stat_bar label="Tatsächlicher Ausgang" name="messagedataout"/>
+					<stat_bar label="Ausstehende Vorgänge im VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulator" name="sim">
diff --git a/indra/newview/skins/default/xui/de/floater_stats.xml b/indra/newview/skins/default/xui/de/floater_stats.xml
index 1838c2081a..4e6f56cd94 100644
--- a/indra/newview/skins/default/xui/de/floater_stats.xml
+++ b/indra/newview/skins/default/xui/de/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Ebenen" name="layersdatareceived"/>
 					<stat_bar label="Tatsächlicher Eingang" name="messagedatain"/>
 					<stat_bar label="Tatsächlicher Ausgang" name="messagedataout"/>
+					<stat_bar label="Ausstehende Vorgänge im VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulator" name="sim">
diff --git a/indra/newview/skins/default/xui/de/strings.xml b/indra/newview/skins/default/xui/de/strings.xml
index f021e03dc7..43327c132d 100644
--- a/indra/newview/skins/default/xui/de/strings.xml
+++ b/indra/newview/skins/default/xui/de/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		Textur-Cache wird initialisiert...
 	</string>
+	<string name="StartupInitializingVFS">
+		VFS wird initialisiert...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Grafikinitialisierung fehlgeschlagen. Bitte aktualisieren Sie Ihren Grafiktreiber.
 	</string>
@@ -70,6 +73,7 @@ LOD-Faktor: [LOD_FACTOR]
 Darstellungsqualität: [RENDER_QUALITY]
 Erweitertes Beleuchtungsmodell: [GPU_SHADERS]
 Texturspeicher: [TEXTURE_MEMORY] MB
+Erstellungszeit VFS (Cache): [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		HiDPI-Anzeigemodus: [HIDPI]
diff --git a/indra/newview/skins/default/xui/en/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/en/floater_scene_load_stats.xml
index 35d4385487..62cce3a1e3 100644
--- a/indra/newview/skins/default/xui/en/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/en/floater_scene_load_stats.xml
@@ -207,6 +207,12 @@
                     tick_spacing="128.f"
                     precision="1"
                     show_bar="false"/>
+			    <stat_bar name="vfspendingoperations"
+                    label="VFS Pending Operations"
+                    orientation="horizontal"
+                    stat="vfspendingoperations"
+                    unit_label=" Ops."
+                    show_bar="false"/>
 			  </stat_view>
 		  </stat_view>
 <!--Sim Stats-->
diff --git a/indra/newview/skins/default/xui/en/floater_stats.xml b/indra/newview/skins/default/xui/en/floater_stats.xml
index f9d44b2c69..e4f735740b 100644
--- a/indra/newview/skins/default/xui/en/floater_stats.xml
+++ b/indra/newview/skins/default/xui/en/floater_stats.xml
@@ -198,6 +198,10 @@
                     stat="messagedataout"
                     decimal_digits="1"
                     show_history="false"/>
+          <stat_bar name="vfspendingoperations"
+                    label="VFS Pending Operations"
+                    stat="vfspendingoperations"
+                    unit_label="Ops."/>
         </stat_view>
       </stat_view>
 
diff --git a/indra/newview/skins/default/xui/en/strings.xml b/indra/newview/skins/default/xui/en/strings.xml
index 619c869a3d..f9f12e7f5c 100644
--- a/indra/newview/skins/default/xui/en/strings.xml
+++ b/indra/newview/skins/default/xui/en/strings.xml
@@ -17,6 +17,7 @@
 	<string name="StartupLoading">Loading [APP_NAME]...</string>
 	<string name="StartupClearingCache">Clearing cache...</string>
 	<string name="StartupInitializingTextureCache">Initializing texture cache...</string>
+	<string name="StartupInitializingVFS">Initializing VFS...</string>
 	<string name="StartupRequireDriverUpdate">Graphics initialization failed. Please update your graphics driver!</string>
 
 	<!-- about dialog/support string-->
@@ -55,9 +56,9 @@ LOD factor: [LOD_FACTOR]
 Render quality: [RENDER_QUALITY]
 Advanced Lighting Model: [GPU_SHADERS]
 Texture memory: [TEXTURE_MEMORY]MB
-Disk cache: [DISK_CACHE_INFO]
+VFS (cache) creation time: [VFS_TIME]
 	</string>
-  <string name="AboutOSXHiDPI">
+	<string name="AboutOSXHiDPI">
 HiDPI display mode: [HIDPI]
 	</string>
 	<string name="AboutLibs">
diff --git a/indra/newview/skins/default/xui/es/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/es/floater_scene_load_stats.xml
index cfc5e524b5..f625d5257c 100644
--- a/indra/newview/skins/default/xui/es/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/es/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Capas" name="layersdatareceived"/>
 					<stat_bar label="Entrando ahora" name="messagedatain"/>
 					<stat_bar label="Saliendo ahora" name="messagedataout"/>
+					<stat_bar label="Operaciones VFS pendientes" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulador" name="sim">
diff --git a/indra/newview/skins/default/xui/es/floater_stats.xml b/indra/newview/skins/default/xui/es/floater_stats.xml
index 0aec786f25..d1c5e867db 100644
--- a/indra/newview/skins/default/xui/es/floater_stats.xml
+++ b/indra/newview/skins/default/xui/es/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Capas" name="layersdatareceived"/>
 					<stat_bar label="Entrando ahora" name="messagedatain"/>
 					<stat_bar label="Saliendo ahora" name="messagedataout"/>
+					<stat_bar label="Operaciones VFS pendientes" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulador" name="sim">
diff --git a/indra/newview/skins/default/xui/es/strings.xml b/indra/newview/skins/default/xui/es/strings.xml
index ebb4ceaa7e..f5e7d0bf4e 100644
--- a/indra/newview/skins/default/xui/es/strings.xml
+++ b/indra/newview/skins/default/xui/es/strings.xml
@@ -22,6 +22,9 @@
 	<string name="StartupInitializingTextureCache">
 		Iniciando la caché de las texturas...
 	</string>
+	<string name="StartupInitializingVFS">
+		Iniciando VFS...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Error de inicialización de gráficos. Actualiza tu controlador de gráficos.
 	</string>
@@ -62,6 +65,7 @@ Factor LOD: [LOD_FACTOR]
 Calidad de renderización: [RENDER_QUALITY]
 Modelo de iluminación avanzado: [GPU_SHADERS]
 Memoria de textura: [TEXTURE_MEMORY]MB
+VFS (cache) hora de creación: [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		Modo de visualización HiDPi: [HIDPI]
diff --git a/indra/newview/skins/default/xui/fr/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/fr/floater_scene_load_stats.xml
index 3889b13f0c..62830054bf 100644
--- a/indra/newview/skins/default/xui/fr/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/fr/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Couches" name="layersdatareceived"/>
 					<stat_bar label="Arrivés" name="messagedatain"/>
 					<stat_bar label="Sortis" name="messagedataout"/>
+					<stat_bar label="Opérations VFS en attente" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulateur" name="sim">
diff --git a/indra/newview/skins/default/xui/fr/floater_stats.xml b/indra/newview/skins/default/xui/fr/floater_stats.xml
index d0f7f42939..fae17e3608 100644
--- a/indra/newview/skins/default/xui/fr/floater_stats.xml
+++ b/indra/newview/skins/default/xui/fr/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Couches" name="layersdatareceived"/>
 					<stat_bar label="Arrivés" name="messagedatain"/>
 					<stat_bar label="Sortis" name="messagedataout"/>
+					<stat_bar label="Opérations VFS en attente" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulateur" name="sim">
diff --git a/indra/newview/skins/default/xui/fr/strings.xml b/indra/newview/skins/default/xui/fr/strings.xml
index 9fde703d6c..f26eac545a 100644
--- a/indra/newview/skins/default/xui/fr/strings.xml
+++ b/indra/newview/skins/default/xui/fr/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		Initialisation du cache des textures...
 	</string>
+	<string name="StartupInitializingVFS">
+		Initialisation VFS...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Échec d&apos;initialisation des graphiques. Veuillez mettre votre pilote graphique à jour.
 	</string>
@@ -71,6 +74,7 @@ Facteur LOD (niveau de détail) : [LOD_FACTOR]
 Qualité de rendu : [RENDER_QUALITY]
 Modèle d’éclairage avancé : [GPU_SHADERS]
 Mémoire textures : [TEXTURE_MEMORY] Mo
+Heure de création VFS (cache) : [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		Mode d&apos;affichage HiDPI : [HIDPI]
diff --git a/indra/newview/skins/default/xui/it/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/it/floater_scene_load_stats.xml
index efceb05298..ca18812eb7 100644
--- a/indra/newview/skins/default/xui/it/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/it/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Livelli" name="layersdatareceived"/>
 					<stat_bar label="Effettivi in ingresso" name="messagedatain"/>
 					<stat_bar label="Effettivi in uscita" name="messagedataout"/>
+					<stat_bar label="Operazioni VFS in sospeso" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulatore" name="sim">
diff --git a/indra/newview/skins/default/xui/it/floater_stats.xml b/indra/newview/skins/default/xui/it/floater_stats.xml
index 6434c3b66b..7ef13aa37f 100644
--- a/indra/newview/skins/default/xui/it/floater_stats.xml
+++ b/indra/newview/skins/default/xui/it/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Livelli" name="layersdatareceived"/>
 					<stat_bar label="Effettivi in ingresso" name="messagedatain"/>
 					<stat_bar label="Effettivi in uscita" name="messagedataout"/>
+					<stat_bar label="Operazioni VFS in sospeso" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulatore" name="sim">
diff --git a/indra/newview/skins/default/xui/it/strings.xml b/indra/newview/skins/default/xui/it/strings.xml
index 3049828f46..f0466cea81 100644
--- a/indra/newview/skins/default/xui/it/strings.xml
+++ b/indra/newview/skins/default/xui/it/strings.xml
@@ -28,6 +28,9 @@
 	<string name="StartupInitializingTextureCache">
 		Inizializzazione della cache texture...
 	</string>
+	<string name="StartupInitializingVFS">
+		Inizializzazione VFS...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Inizializzazione grafica non riuscita. Aggiorna il driver della scheda grafica!
 	</string>
@@ -68,6 +71,7 @@ Fattore livello di dettaglio: [LOD_FACTOR]
 Qualità di rendering: [RENDER_QUALITY]
 Modello illuminazione avanzato: [GPU_SHADERS]
 Memoria texture: [TEXTURE_MEMORY]MB
+Data/ora creazione VFS (cache): [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		Modalità display HiDPI: [HIDPI]
diff --git a/indra/newview/skins/default/xui/ja/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/ja/floater_scene_load_stats.xml
index f348ce3c4d..f6edce026f 100644
--- a/indra/newview/skins/default/xui/ja/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/ja/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="レイヤー" name="layersdatareceived"/>
 					<stat_bar label="実際の受信" name="messagedatain"/>
 					<stat_bar label="実際の送信" name="messagedataout"/>
+					<stat_bar label="VFS 保留中の操作" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="シミュレーター" name="sim">
diff --git a/indra/newview/skins/default/xui/ja/floater_stats.xml b/indra/newview/skins/default/xui/ja/floater_stats.xml
index 1da0e5ebc9..3bc343639b 100644
--- a/indra/newview/skins/default/xui/ja/floater_stats.xml
+++ b/indra/newview/skins/default/xui/ja/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="レイヤー" name="layersdatareceived"/>
 					<stat_bar label="実際の受信" name="messagedatain"/>
 					<stat_bar label="実際の送信" name="messagedataout"/>
+					<stat_bar label="VFS 保留中の操作" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="シミュレーター" name="sim">
diff --git a/indra/newview/skins/default/xui/ja/strings.xml b/indra/newview/skins/default/xui/ja/strings.xml
index dcd6e65d34..52d6fb0c2b 100644
--- a/indra/newview/skins/default/xui/ja/strings.xml
+++ b/indra/newview/skins/default/xui/ja/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		テクスチャキャッシュを初期化中です...
 	</string>
+	<string name="StartupInitializingVFS">
+		VFS を初期化中です...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		グラフィックを初期化できませんでした。グラフィックドライバを更新してください。
 	</string>
@@ -71,6 +74,7 @@ LOD 係数: [LOD_FACTOR]
 描画の質: [RENDER_QUALITY]
 高度なライティングモデル: [GPU_SHADERS]
 テクスチャメモリ: [TEXTURE_MEMORY]MB
+VFS（キャッシュ）作成時間: [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		HiDPI 表示モード: [HIDPI]
diff --git a/indra/newview/skins/default/xui/pl/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/pl/floater_scene_load_stats.xml
index 8f5d0c5c70..6fdc7e19f6 100644
--- a/indra/newview/skins/default/xui/pl/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/pl/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar name="layersdatareceived" label="Warstwy" />
 					<stat_bar name="messagedatain" label="Aktualna il. wchodząca" />
 					<stat_bar name="messagedataout" label="Aktualna il. wychodząca" />
+					<stat_bar name="vfspendingoperations" label="Operacje oczekujące VFS" unit_label=" op." />
 				</stat_view>
 			</stat_view>
 			<stat_view name="sim" label="Symulator">
diff --git a/indra/newview/skins/default/xui/pl/floater_stats.xml b/indra/newview/skins/default/xui/pl/floater_stats.xml
index 21e37717c2..5dd7d19bab 100644
--- a/indra/newview/skins/default/xui/pl/floater_stats.xml
+++ b/indra/newview/skins/default/xui/pl/floater_stats.xml
@@ -55,6 +55,7 @@
 					<stat_bar label="Warstwy" name="layersdatareceived" />
 					<stat_bar label="Aktualna il. wchodząca" name="messagedatain" />
 					<stat_bar label="Aktualna il. wychodząca" name="messagedataout" />
+					<stat_bar label="Operacje oczekujące VFS" name="vfspendingoperations" />
 				</stat_view>
 			</stat_view>
 			<stat_view label="Symulator" name="sim">
diff --git a/indra/newview/skins/default/xui/pl/strings.xml b/indra/newview/skins/default/xui/pl/strings.xml
index cf033df3c9..91fea234d2 100644
--- a/indra/newview/skins/default/xui/pl/strings.xml
+++ b/indra/newview/skins/default/xui/pl/strings.xml
@@ -15,6 +15,9 @@
 	<string name="StartupInitializingTextureCache">
 		Inicjowanie bufora danych tekstur...
 	</string>
+	<string name="StartupInitializingVFS">
+		Inicjowanie wirtualnego systemu plików...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Nie można zainicjować grafiki. Zaktualizuj sterowniki!
 	</string>
diff --git a/indra/newview/skins/default/xui/pt/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/pt/floater_scene_load_stats.xml
index dbaab1d782..027e1ef311 100644
--- a/indra/newview/skins/default/xui/pt/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/pt/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Layers" name="layersdatareceived"/>
 					<stat_bar label="Actual In" name="messagedatain"/>
 					<stat_bar label="Actual Out" name="messagedataout"/>
+					<stat_bar label="Operações pendentes do VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulator" name="sim">
diff --git a/indra/newview/skins/default/xui/pt/floater_stats.xml b/indra/newview/skins/default/xui/pt/floater_stats.xml
index 3253984268..f41fe17778 100644
--- a/indra/newview/skins/default/xui/pt/floater_stats.xml
+++ b/indra/newview/skins/default/xui/pt/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Layers" name="layersdatareceived"/>
 					<stat_bar label="Actual In" name="messagedatain"/>
 					<stat_bar label="Actual Out" name="messagedataout"/>
+					<stat_bar label="Operações pendentes do VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simulator" name="sim">
diff --git a/indra/newview/skins/default/xui/pt/strings.xml b/indra/newview/skins/default/xui/pt/strings.xml
index c72a41fd3a..ee982b5b22 100644
--- a/indra/newview/skins/default/xui/pt/strings.xml
+++ b/indra/newview/skins/default/xui/pt/strings.xml
@@ -22,6 +22,9 @@
 	<string name="StartupInitializingTextureCache">
 		Iniciando cache de texturas...
 	</string>
+	<string name="StartupInitializingVFS">
+		Iniciando VFS...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Falha na inicialização dos gráficos. Atualize seu driver gráfico!
 	</string>
@@ -62,6 +65,7 @@ LOD fator: [LOD_FACTOR]
 Qualidade de renderização: [RENDER_QUALITY]
 Modelo avançado de luzes: [GPU_SHADERS]
 Memória de textura: [TEXTURE_MEMORY]MB
+VFS (cache) tempo de criação: [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		HiDPI modo de exibição: [HIDPI]
diff --git a/indra/newview/skins/default/xui/ru/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/ru/floater_scene_load_stats.xml
index c4f432023c..a101e62627 100644
--- a/indra/newview/skins/default/xui/ru/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/ru/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Слои" name="layersdatareceived"/>
 					<stat_bar label="Действительный ввод" name="messagedatain"/>
 					<stat_bar label="Действительный вывод" name="messagedataout"/>
+					<stat_bar label="Ожидающие операции VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Симулятор" name="sim">
diff --git a/indra/newview/skins/default/xui/ru/floater_stats.xml b/indra/newview/skins/default/xui/ru/floater_stats.xml
index a7d26029c2..10e9f5a7f4 100644
--- a/indra/newview/skins/default/xui/ru/floater_stats.xml
+++ b/indra/newview/skins/default/xui/ru/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Слои" name="layersdatareceived"/>
 					<stat_bar label="Действительный ввод" name="messagedatain"/>
 					<stat_bar label="Действительный вывод" name="messagedataout"/>
+					<stat_bar label="Ожидающие операции VFS" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Симулятор" name="sim">
diff --git a/indra/newview/skins/default/xui/ru/strings.xml b/indra/newview/skins/default/xui/ru/strings.xml
index 43a87b2b18..e9592a0476 100644
--- a/indra/newview/skins/default/xui/ru/strings.xml
+++ b/indra/newview/skins/default/xui/ru/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		Инициализация кэша текстур...
 	</string>
+	<string name="StartupInitializingVFS">
+		Инициализация виртуальной файловой системы...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Ошибка инициализации графики. Обновите графический драйвер!
 	</string>
@@ -71,6 +74,7 @@ SLURL: &lt;nolink&gt;[SLURL]&lt;/nolink&gt;
 Качество визуализации: [RENDER_QUALITY]
 Расширенная модель освещения: [GPU_SHADERS]
 Память текстур: [TEXTURE_MEMORY] МБ
+Время создания VFS (кэш): [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		Режим отображения HiDPI: [HIDPI]
diff --git a/indra/newview/skins/default/xui/tr/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/tr/floater_scene_load_stats.xml
index 7d5f4adb02..ae0a94595d 100644
--- a/indra/newview/skins/default/xui/tr/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/tr/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="Katmanlar" name="layersdatareceived"/>
 					<stat_bar label="Gerçekte Gelen" name="messagedatain"/>
 					<stat_bar label="Gerçekte Giden" name="messagedataout"/>
+					<stat_bar label="VFS Bekleyen İşlemler" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simülatör" name="sim">
diff --git a/indra/newview/skins/default/xui/tr/floater_stats.xml b/indra/newview/skins/default/xui/tr/floater_stats.xml
index bd36d4916f..1ae42ad382 100644
--- a/indra/newview/skins/default/xui/tr/floater_stats.xml
+++ b/indra/newview/skins/default/xui/tr/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="Katmanlar" name="layersdatareceived"/>
 					<stat_bar label="Gerçekte Gelen" name="messagedatain"/>
 					<stat_bar label="Gerçekte Giden" name="messagedataout"/>
+					<stat_bar label="VFS Bekleyen İşlemler" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="Simülatör" name="sim">
diff --git a/indra/newview/skins/default/xui/tr/strings.xml b/indra/newview/skins/default/xui/tr/strings.xml
index 982de76a5b..56fad978f5 100644
--- a/indra/newview/skins/default/xui/tr/strings.xml
+++ b/indra/newview/skins/default/xui/tr/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		Doku önbelleği başlatılıyor...
 	</string>
+	<string name="StartupInitializingVFS">
+		VFS Başlatılıyor...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		Grafik başlatma başarılamadı. Lütfen grafik sürücünüzü güncelleştirin!
 	</string>
@@ -71,6 +74,7 @@ LOD faktörü: [LOD_FACTOR]
 İşleme kalitesi: [RENDER_QUALITY]
 Gelişmiş Aydınlatma Modeli: [GPU_SHADERS]
 Doku belleği: [TEXTURE_MEMORY]MB
+VFS (önbellek) oluşturma saati: [VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		HiDPI görüntü modu: [HIDPI]
diff --git a/indra/newview/skins/default/xui/zh/floater_scene_load_stats.xml b/indra/newview/skins/default/xui/zh/floater_scene_load_stats.xml
index 20344e299f..1a5c20abeb 100644
--- a/indra/newview/skins/default/xui/zh/floater_scene_load_stats.xml
+++ b/indra/newview/skins/default/xui/zh/floater_scene_load_stats.xml
@@ -29,6 +29,7 @@
 					<stat_bar label="層次" name="layersdatareceived"/>
 					<stat_bar label="實入" name="messagedatain"/>
 					<stat_bar label="實出" name="messagedataout"/>
+					<stat_bar label="VFS 待行作業" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="模擬器" name="sim">
diff --git a/indra/newview/skins/default/xui/zh/floater_stats.xml b/indra/newview/skins/default/xui/zh/floater_stats.xml
index e233ece527..f06eb5e78f 100644
--- a/indra/newview/skins/default/xui/zh/floater_stats.xml
+++ b/indra/newview/skins/default/xui/zh/floater_stats.xml
@@ -56,6 +56,7 @@
 					<stat_bar label="層次" name="layersdatareceived"/>
 					<stat_bar label="實入" name="messagedatain"/>
 					<stat_bar label="實出" name="messagedataout"/>
+					<stat_bar label="VFS 待行作業" name="vfspendingoperations"/>
 				</stat_view>
 			</stat_view>
 			<stat_view label="模擬器" name="sim">
diff --git a/indra/newview/skins/default/xui/zh/strings.xml b/indra/newview/skins/default/xui/zh/strings.xml
index 3221cde3b7..e6c61a5d94 100644
--- a/indra/newview/skins/default/xui/zh/strings.xml
+++ b/indra/newview/skins/default/xui/zh/strings.xml
@@ -31,6 +31,9 @@
 	<string name="StartupInitializingTextureCache">
 		正在初始化材質快取...
 	</string>
+	<string name="StartupInitializingVFS">
+		VFS 初始化中...
+	</string>
 	<string name="StartupRequireDriverUpdate">
 		顯像初始化失敗。 請更新你的顯像卡驅動程式！
 	</string>
@@ -71,6 +74,7 @@
 呈像品質：[RENDER_QUALITY]
 進階照明模型：[GPU_SHADERS]
 材質記憶體：[TEXTURE_MEMORY]MB
+VFS（快取）建立時間：[VFS_TIME]
 	</string>
 	<string name="AboutOSXHiDPI">
 		HiDPI顯示模式：[HIDPI]
diff --git a/indra/newview/viewer_manifest.py b/indra/newview/viewer_manifest.py
index 8eee583a48..6d231040f7 100755
--- a/indra/newview/viewer_manifest.py
+++ b/indra/newview/viewer_manifest.py
@@ -69,6 +69,7 @@ class ViewerManifest(LLManifest):
                 self.exclude("logcontrol-dev.xml")
                 self.path("*.ini")
                 self.path("*.xml")
+                self.path("*.db2")
 
                 # include the entire shaders directory recursively
                 self.path("shaders")
diff --git a/indra/test/CMakeLists.txt b/indra/test/CMakeLists.txt
index b3bff3611a..87536e146b 100644
--- a/indra/test/CMakeLists.txt
+++ b/indra/test/CMakeLists.txt
@@ -8,11 +8,12 @@ include(LLCoreHttp)
 include(LLInventory)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLXML)
 include(Linking)
 include(Tut)
 include(LLAddBuildTest)
+
 include(GoogleMock)
 
 include_directories(
@@ -22,7 +23,7 @@ include_directories(
     ${LLMATH_INCLUDE_DIRS}
     ${LLMESSAGE_INCLUDE_DIRS}
     ${LLINVENTORY_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
     ${LSCRIPT_INCLUDE_DIRS}
     ${GOOGLEMOCK_INCLUDE_DIRS}
@@ -88,7 +89,7 @@ target_link_libraries(lltest
     ${LLINVENTORY_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
     ${LLMATH_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LSCRIPT_LIBRARIES}
     ${LLCOMMON_LIBRARIES}
diff --git a/indra/win_crash_logger/CMakeLists.txt b/indra/win_crash_logger/CMakeLists.txt
index 1b187d624a..86aa655f03 100644
--- a/indra/win_crash_logger/CMakeLists.txt
+++ b/indra/win_crash_logger/CMakeLists.txt
@@ -8,7 +8,7 @@ include(LLCoreHttp)
 include(LLCrashLogger)
 include(LLMath)
 include(LLMessage)
-include(LLFileSystem)
+include(LLVFS)
 include(LLWindow)
 include(LLXML)
 include(Linking)
@@ -23,7 +23,7 @@ include_directories(
     ${LLMATH_INCLUDE_DIRS}
     ${LLWINDOW_INCLUDE_DIRS}
     ${LLXML_INCLUDE_DIRS}
-    ${LLFILESYSTEM_INCLUDE_DIRS}
+    ${LLVFS_INCLUDE_DIRS}
     ${BREAKPAD_INCLUDE_DIRECTORIES}
     )
 include_directories(SYSTEM
@@ -76,7 +76,7 @@ target_link_libraries(windows-crash-logger
     ${BREAKPAD_EXCEPTION_HANDLER_LIBRARIES}
     ${LLCRASHLOGGER_LIBRARIES}
     ${LLWINDOW_LIBRARIES}
-    ${LLFILESYSTEM_LIBRARIES}
+    ${LLVFS_LIBRARIES}
     ${LLXML_LIBRARIES}
     ${LLMESSAGE_LIBRARIES}
     ${LLMATH_LIBRARIES}