Revert "Merge branch 'master' of https://bitbucket.org/lindenlab/viewer into DRTVWR-519"

This reverts commit e61f485a04dc8c8ac6bcf6a24848359092884d14, reversing
changes made to 00c47d079f7e958e473ed4083a7f7691fa02dcd5.

1 files changed, 2220 insertions, 0 deletions

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);
+	}
+}