Adding fsx test to yaffs direct
[yaffs2.git] / yaffs_guts.c
index 2736cedc52dab26e45b3973e549c2f39d9dd3521..c29c1f990cf0a0e5cfa1e322a2366630d52f0ac3 100644 (file)
@@ -1,7 +1,7 @@
 /*
- * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
  *
- * Copyright (C) 2002 Aleph One Ltd.
+ * Copyright (C) 2002-2007 Aleph One Ltd.
  *   for Toby Churchill Ltd and Brightstar Engineering
  *
  * Created by Charles Manning <charles@aleph1.co.uk>
@@ -9,11 +9,10 @@
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
  */
 
 const char *yaffs_guts_c_version =
-    "$Id: yaffs_guts.c,v 1.41 2006-11-07 23:26:52 charles Exp $";
+    "$Id: yaffs_guts.c,v 1.52 2007-10-16 00:45:05 charles Exp $";
 
 #include "yportenv.h"
 
@@ -22,7 +21,7 @@ const char *yaffs_guts_c_version =
 #include "yaffs_tagsvalidity.h"
 
 #include "yaffs_tagscompat.h"
-#ifndef CONFIG_YAFFS_OWN_SORT
+#ifndef  CONFIG_YAFFS_USE_OWN_SORT
 #include "yaffs_qsort.h"
 #endif
 #include "yaffs_nand.h"
@@ -98,6 +97,8 @@ static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockIn
 
 static void yaffs_VerifyFreeChunks(yaffs_Device * dev);
 
+static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
+
 #ifdef YAFFS_PARANOID
 static int yaffs_CheckFileSanity(yaffs_Object * in);
 #else
@@ -109,6 +110,13 @@ static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId);
 
 static void yaffs_InvalidateCheckpoint(yaffs_Device *dev);
 
+static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
+                                yaffs_ExtendedTags * tags);
+
+static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos);
+static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
+                                         yaffs_FileStructure * fStruct,
+                                         __u32 chunkId);
 
 
 /* Function to calculate chunk and offset */
@@ -182,6 +190,23 @@ static __u32 ShiftDiv(__u32 x)
  * Temporary buffer manipulations.
  */
 
+static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)      
+{
+       int i;
+       __u8 *buf = (__u8 *)1;
+               
+       memset(dev->tempBuffer,0,sizeof(dev->tempBuffer));
+               
+       for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+               dev->tempBuffer[i].line = 0;    /* not in use */
+               dev->tempBuffer[i].buffer = buf =
+                   YMALLOC_DMA(dev->nDataBytesPerChunk);
+       }
+               
+       return buf ? YAFFS_OK : YAFFS_FAIL;
+       
+}
+
 static __u8 *yaffs_GetTempBuffer(yaffs_Device * dev, int lineNo)
 {
        int i, j;
@@ -265,6 +290,8 @@ int yaffs_IsManagedTempBuffer(yaffs_Device * dev, const __u8 * buffer)
     return 0;
 }
 
+
+
 /*
  * Chunk bitmap manipulations
  */
@@ -281,6 +308,16 @@ static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device * dev, int blk)
            (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
 }
 
+static Y_INLINE void yaffs_VerifyChunkBitId(yaffs_Device *dev, int blk, int chunk)
+{
+       if(blk < dev->internalStartBlock || blk > dev->internalEndBlock ||
+          chunk < 0 || chunk >= dev->nChunksPerBlock) {
+          T(YAFFS_TRACE_ERROR,
+           (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),blk,chunk));
+           YBUG();
+       }
+}
+
 static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device * dev, int blk)
 {
        __u8 *blkBits = yaffs_BlockBits(dev, blk);
@@ -292,12 +329,16 @@ static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device * dev, int blk, int chunk)
 {
        __u8 *blkBits = yaffs_BlockBits(dev, blk);
 
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
+
        blkBits[chunk / 8] &= ~(1 << (chunk & 7));
 }
 
 static Y_INLINE void yaffs_SetChunkBit(yaffs_Device * dev, int blk, int chunk)
 {
        __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
 
        blkBits[chunk / 8] |= (1 << (chunk & 7));
 }
@@ -305,6 +346,8 @@ static Y_INLINE void yaffs_SetChunkBit(yaffs_Device * dev, int blk, int chunk)
 static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device * dev, int blk, int chunk)
 {
        __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
+
        return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
 }
 
@@ -320,6 +363,491 @@ static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device * dev, int blk)
        return 0;
 }
 
+static int yaffs_CountChunkBits(yaffs_Device * dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       int i;
+       int n = 0;
+       for (i = 0; i < dev->chunkBitmapStride; i++) {
+               __u8 x = *blkBits;
+               while(x){
+                       if(x & 1)
+                               n++;
+                       x >>=1;
+               }
+                       
+               blkBits++;
+       }
+       return n;
+}
+
+/* 
+ * Verification code
+ */
+static int yaffs_SkipVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_SkipFullVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_SkipNANDVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_NAND));
+}
+
+static const char * blockStateName[] = {
+"Unknown",
+"Needs scanning",
+"Scanning",
+"Empty",
+"Allocating",
+"Full",
+"Dirty",
+"Checkpoint",
+"Collecting",
+"Dead"
+};
+
+static void yaffs_VerifyBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
+{
+       int actuallyUsed;
+       int inUse;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+               
+       /* Report illegal runtime states */
+       if(bi->blockState <0 || bi->blockState >= YAFFS_NUMBER_OF_BLOCK_STATES)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has undefined state %d"TENDSTR),n,bi->blockState));
+               
+       switch(bi->blockState){
+        case YAFFS_BLOCK_STATE_UNKNOWN:
+        case YAFFS_BLOCK_STATE_SCANNING:
+        case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has bad run-state %s"TENDSTR),
+               n,blockStateName[bi->blockState]));
+       }
+       
+       /* Check pages in use and soft deletions are legal */
+       
+       actuallyUsed = bi->pagesInUse - bi->softDeletions;
+       
+       if(bi->pagesInUse < 0 || bi->pagesInUse > dev->nChunksPerBlock ||
+          bi->softDeletions < 0 || bi->softDeletions > dev->nChunksPerBlock ||
+          actuallyUsed < 0 || actuallyUsed > dev->nChunksPerBlock)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has illegal values pagesInUsed %d softDeletions %d"TENDSTR),
+               n,bi->pagesInUse,bi->softDeletions));
+       
+               
+       /* Check chunk bitmap legal */
+       inUse = yaffs_CountChunkBits(dev,n);
+       if(inUse != bi->pagesInUse)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has inconsistent values pagesInUse %d counted chunk bits %d"TENDSTR),
+                       n,bi->pagesInUse,inUse));
+       
+       /* Check that the sequence number is valid.
+        * Ten million is legal, but is very unlikely 
+        */
+       if(dev->isYaffs2 && 
+          (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING || bi->blockState == YAFFS_BLOCK_STATE_FULL) &&
+          (bi->sequenceNumber < YAFFS_LOWEST_SEQUENCE_NUMBER || bi->sequenceNumber > 10000000 ))
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has suspect sequence number of %d"TENDSTR),
+               n,bi->sequenceNumber));
+               
+}
+
+static void yaffs_VerifyCollectedBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
+{
+       yaffs_VerifyBlock(dev,bi,n);
+       
+       /* After collection the block should be in the erased state */
+       /* TODO: This will need to change if we do partial gc */
+       
+       if(bi->blockState != YAFFS_BLOCK_STATE_EMPTY){
+               T(YAFFS_TRACE_ERROR,(TSTR("Block %d is in state %d after gc, should be erased"TENDSTR),
+                       n,bi->blockState));
+       }
+}
+
+static void yaffs_VerifyBlocks(yaffs_Device *dev)
+{
+       int i;
+       int nBlocksPerState[YAFFS_NUMBER_OF_BLOCK_STATES];
+       int nIllegalBlockStates = 0;
+       
+
+       if(yaffs_SkipVerification(dev))
+               return;
+
+       memset(nBlocksPerState,0,sizeof(nBlocksPerState));
+
+               
+       for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++){
+               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
+               yaffs_VerifyBlock(dev,bi,i);
+
+               if(bi->blockState >=0 && bi->blockState < YAFFS_NUMBER_OF_BLOCK_STATES)
+                       nBlocksPerState[bi->blockState]++;
+               else
+                       nIllegalBlockStates++;
+                                       
+       }
+       
+       T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
+       T(YAFFS_TRACE_VERIFY,(TSTR("Block summary"TENDSTR)));
+       
+       T(YAFFS_TRACE_VERIFY,(TSTR("%d blocks have illegal states"TENDSTR),nIllegalBlockStates));
+       if(nBlocksPerState[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Too many allocating blocks"TENDSTR)));
+
+       for(i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
+               T(YAFFS_TRACE_VERIFY,
+                 (TSTR("%s %d blocks"TENDSTR),
+                 blockStateName[i],nBlocksPerState[i]));
+       
+       if(dev->blocksInCheckpoint != nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT])
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Checkpoint block count wrong dev %d count %d"TENDSTR),
+                dev->blocksInCheckpoint, nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT]));
+                
+       if(dev->nErasedBlocks != nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY])
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Erased block count wrong dev %d count %d"TENDSTR),
+                dev->nErasedBlocks, nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY]));
+                
+       if(nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
+                nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));
+
+       T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
+
+}
+
+/*
+ * Verify the object header. oh must be valid, but obj and tags may be NULL in which
+ * case those tests will not be performed.
+ */
+static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
+{
+       if(yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       if(!(tags && obj && oh)){
+               T(YAFFS_TRACE_VERIFY,
+                               (TSTR("Verifying object header tags %x obj %x oh %x"TENDSTR),
+                               (__u32)tags,(__u32)obj,(__u32)oh));
+               return;
+       }
+       
+       if(oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
+          oh->type > YAFFS_OBJECT_TYPE_MAX)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
+                tags->objectId, oh->type));
+
+       if(tags->objectId != obj->objectId)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
+                tags->objectId, obj->objectId));
+
+
+       /*
+        * Check that the object's parent ids match if parentCheck requested.
+        * 
+        * Tests do not apply to the root object.
+        */
+       
+       if(parentCheck && tags->objectId > 1 && !obj->parent)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
+                tags->objectId, oh->parentObjectId));
+               
+       
+       if(parentCheck && obj->parent &&
+          oh->parentObjectId != obj->parent->objectId && 
+          (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
+           obj->parent->objectId != YAFFS_OBJECTID_DELETED))
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
+                tags->objectId, oh->parentObjectId, obj->parent->objectId));
+               
+       
+       if(tags->objectId > 1 && oh->name[0] == 0) /* Null name */
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d header name is NULL"TENDSTR),
+                obj->objectId));
+
+       if(tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d header name is 0xFF"TENDSTR),
+                obj->objectId));
+}
+
+
+
+static int yaffs_VerifyTnodeWorker(yaffs_Object * obj, yaffs_Tnode * tn,
+                                       __u32 level, int chunkOffset)
+{
+       int i;
+       yaffs_Device *dev = obj->myDev;
+       int ok = 1;
+       int nTnodeBytes = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++){
+                               if (tn->internal[i]) {
+                                       ok = yaffs_VerifyTnodeWorker(obj,
+                                                       tn->internal[i],
+                                                       level - 1,
+                                                       (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
+                               }
+                       }
+               } else if (level == 0) {
+                       int i;
+                       yaffs_ExtendedTags tags;
+                       __u32 objectId = obj->objectId;
+                       
+                       chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
+                       
+                       for(i = 0; i < YAFFS_NTNODES_LEVEL0; i++){
+                               __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                               
+                               if(theChunk > 0){
+                                       /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
+                                       yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
+                                       if(tags.objectId != objectId || tags.chunkId != chunkOffset){
+                                               T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
+                                                       objectId, chunkOffset, theChunk,
+                                                       tags.objectId, tags.chunkId));
+                                       }
+                               }
+                               chunkOffset++;
+                       }
+               }
+       }
+
+       return ok;
+
+}
+
+
+static void yaffs_VerifyFile(yaffs_Object *obj)
+{
+       int requiredTallness;
+       int actualTallness;
+       __u32 lastChunk;
+       __u32 x;
+       __u32 i;
+       int ok;
+       yaffs_Device *dev;
+       yaffs_ExtendedTags tags;
+       yaffs_Tnode *tn;
+       __u32 objectId;
+       
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+       
+       dev = obj->myDev;
+       objectId = obj->objectId;
+       
+       /* Check file size is consistent with tnode depth */
+       lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
+       x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
+       requiredTallness = 0;
+       while (x> 0) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               requiredTallness++;
+       }
+       
+       actualTallness = obj->variant.fileVariant.topLevel;
+       
+       if(requiredTallness > actualTallness )
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d had tnode tallness %d, needs to be %d"TENDSTR),
+                obj->objectId,actualTallness, requiredTallness));
+       
+       
+       /* Check that the chunks in the tnode tree are all correct. 
+        * We do this by scanning through the tnode tree and
+        * checking the tags for every chunk match.
+        */
+
+       if(yaffs_SkipNANDVerification(dev))
+               return;
+               
+       for(i = 1; i <= lastChunk; i++){
+               tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant,i);
+
+               if (tn) {
+                       __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                       if(theChunk > 0){
+                               /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
+                               yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
+                               if(tags.objectId != objectId || tags.chunkId != i){
+                                       T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
+                                               objectId, i, theChunk,
+                                               tags.objectId, tags.chunkId));
+                               }
+                       }
+               }
+
+       }
+
+}
+
+static void yaffs_VerifyDirectory(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+       
+}
+
+static void yaffs_VerifyHardLink(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       /* Verify sane equivalent object */
+}
+
+static void yaffs_VerifySymlink(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       /* Verify symlink string */
+}
+
+static void yaffs_VerifySpecial(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+}
+
+static void yaffs_VerifyObject(yaffs_Object *obj)
+{
+       yaffs_Device *dev;
+       
+       __u32 chunkMin;
+       __u32 chunkMax;
+       
+       __u32 chunkIdOk;
+       __u32 chunkIsLive;
+       
+       if(!obj)
+               return;
+       
+       dev = obj->myDev;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+               
+       /* Check sane object header chunk */
+       
+       chunkMin = dev->internalStartBlock * dev->nChunksPerBlock;
+       chunkMax = (dev->internalEndBlock+1) * dev->nChunksPerBlock - 1;
+       
+       chunkIdOk = (obj->chunkId >= chunkMin && obj->chunkId <= chunkMax);
+       chunkIsLive = chunkIdOk && 
+                       yaffs_CheckChunkBit(dev, 
+                                           obj->chunkId / dev->nChunksPerBlock,
+                                           obj->chunkId % dev->nChunksPerBlock);
+       if(!obj->fake && 
+           (!chunkIdOk || !chunkIsLive)) {
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
+          obj->objectId,obj->chunkId,
+          chunkIdOk ? "" : ",out of range",
+          chunkIsLive || !chunkIdOk ? "" : ",marked as deleted"));
+       }
+       
+       if(chunkIdOk && chunkIsLive &&!yaffs_SkipNANDVerification(dev)) {
+               yaffs_ExtendedTags tags;
+               yaffs_ObjectHeader *oh;
+               __u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
+               
+               oh = (yaffs_ObjectHeader *)buffer;
+               
+               yaffs_ReadChunkWithTagsFromNAND(dev, obj->chunkId,buffer, &tags);
+               
+               yaffs_VerifyObjectHeader(obj,oh,&tags,1);
+               
+               yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
+       }
+       
+       /* Verify it has a parent */
+       if(obj && !obj->fake &&
+          (!obj->parent || obj->parent->myDev != dev)){
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
+          obj->objectId,obj->parent));    
+       }
+       
+       /* Verify parent is a directory */
+       if(obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY){
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
+          obj->objectId,obj->parent->variantType));       
+       }
+       
+       switch(obj->variantType){
+       case YAFFS_OBJECT_TYPE_FILE:
+               yaffs_VerifyFile(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               yaffs_VerifySymlink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               yaffs_VerifyDirectory(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               yaffs_VerifyHardLink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               yaffs_VerifySpecial(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+       default:
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d has illegaltype %d"TENDSTR),
+               obj->objectId,obj->variantType));          
+               break;
+       }
+       
+       
+}
+
+static void yaffs_VerifyObjects(yaffs_Device *dev)
+{
+       yaffs_Object *obj;
+       int i;
+       struct list_head *lh;
+
+       if(yaffs_SkipVerification(dev))
+               return;
+       
+       /* Iterate through the objects in each hash entry */
+        
+        for(i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++){
+               list_for_each(lh, &dev->objectBucket[i].list) {
+                       if (lh) {
+                               obj = list_entry(lh, yaffs_Object, hashLink);
+                               yaffs_VerifyObject(obj);
+                       }
+               }
+        }
+
+}
+
+
 /*
  *  Simple hash function. Needs to have a reasonable spread
  */
@@ -392,86 +920,88 @@ static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
                                             yaffs_ExtendedTags * tags,
                                             int useReserve)
 {
+       int attempts = 0;
+       int writeOk = 0;
        int chunk;
 
-       int writeOk = 0;
-       int erasedOk = 1;
-       int attempts = 0;
-       yaffs_BlockInfo *bi;
-       
        yaffs_InvalidateCheckpoint(dev);
 
        do {
-               chunk = yaffs_AllocateChunk(dev, useReserve,&bi);
-
-               if (chunk >= 0) {
-                       /* First check this chunk is erased, if it needs checking.
-                        * The checking policy (unless forced always on) is as follows:
-                        * Check the first page we try to write in a block.
-                        * - If the check passes then we don't need to check any more.
-                        * - If the check fails, we check again...
-                        * If the block has been erased, we don't need to check.
-                        *
-                        * However, if the block has been prioritised for gc, then
-                        * we think there might be something odd about this block
-                        * and stop using it.
-                        *
-                        * Rationale:
-                        * We should only ever see chunks that have not been erased
-                        * if there was a partially written chunk due to power loss
-                        * This checking policy should catch that case with very
-                        * few checks and thus save a lot of checks that are most likely not
-                        * needed.
-                        */
-                        
-                        if(bi->gcPrioritise){
-                                       yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
-                       } else {
-#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+               yaffs_BlockInfo *bi = 0;
+               int erasedOk = 0;
+
+               chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
+               if (chunk < 0) {
+                       /* no space */
+                       break;
+               }
+
+               /* First check this chunk is erased, if it needs
+                * checking.  The checking policy (unless forced
+                * always on) is as follows:
+                *
+                * Check the first page we try to write in a block.
+                * If the check passes then we don't need to check any
+                * more.        If the check fails, we check again...
+                * If the block has been erased, we don't need to check.
+                *
+                * However, if the block has been prioritised for gc,
+                * then we think there might be something odd about
+                * this block and stop using it.
+                *
+                * Rationale: We should only ever see chunks that have
+                * not been erased if there was a partially written
+                * chunk due to power loss.  This checking policy should
+                * catch that case with very few checks and thus save a
+                * lot of checks that are most likely not needed.
+                */
+               if (bi->gcPrioritise) {
+                       yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
+                       /* try another chunk */
+                       continue;
+               }
 
-                               bi->skipErasedCheck = 0;
+               /* let's give it a try */
+               attempts++;
 
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+               bi->skipErasedCheck = 0;
 #endif
-                               if(!bi->skipErasedCheck){
-                                       erasedOk = yaffs_CheckChunkErased(dev, chunk);
-                                       if(erasedOk && !bi->gcPrioritise)
-                                               bi->skipErasedCheck = 1;
-                               }
-
-                               if (!erasedOk) {
-                                       T(YAFFS_TRACE_ERROR,
-                                         (TSTR
-                                          ("**>> yaffs chunk %d was not erased"
-                                           TENDSTR), chunk));
-                               } else {
-                                       writeOk =
-                                           yaffs_WriteChunkWithTagsToNAND(dev, chunk,
-                                                                          data, tags);
-                               }
-                       
-                               attempts++;
+               if (!bi->skipErasedCheck) {
+                       erasedOk = yaffs_CheckChunkErased(dev, chunk);
+                       if (erasedOk != YAFFS_OK) {
+                               T(YAFFS_TRACE_ERROR,
+                               (TSTR ("**>> yaffs chunk %d was not erased"
+                               TENDSTR), chunk));
 
-                               if (writeOk) {
-                                       /*
-                                        *  Copy the data into the robustification buffer.
-                                        *  NB We do this at the end to prevent duplicates in the case of a write error.
-                                        *  Todo
-                                        */
-                                       yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
-                               
-                               } else {
-                                       /* The erased check or write failed */
-                                       yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
-                               }
+                               /* try another chunk */
+                               continue;
                        }
+                       bi->skipErasedCheck = 1;
                }
 
-       } while (chunk >= 0 && !writeOk);
+               writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
+                               data, tags);
+               if (writeOk != YAFFS_OK) {
+                       yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
+                       /* try another chunk */
+                       continue;
+               }
+
+               /* Copy the data into the robustification buffer */
+               yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
+
+       } while (writeOk != YAFFS_OK && 
+               (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+       
+       if(!writeOk)
+               chunk = -1;
 
        if (attempts > 1) {
                T(YAFFS_TRACE_ERROR,
-                 (TSTR("**>> yaffs write required %d attempts" TENDSTR),
-                  attempts));
+                       (TSTR("**>> yaffs write required %d attempts" TENDSTR),
+                       attempts));
+
                dev->nRetriedWrites += (attempts - 1);
        }
 
@@ -484,13 +1014,15 @@ static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
  
 static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND)
 {
+       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
 
        yaffs_InvalidateCheckpoint(dev);
        
        yaffs_MarkBlockBad(dev, blockInNAND);
 
-       yaffs_GetBlockInfo(dev, blockInNAND)->blockState =
-           YAFFS_BLOCK_STATE_DEAD;
+       bi->blockState = YAFFS_BLOCK_STATE_DEAD;
+       bi->gcPrioritise = 0;
+       bi->needsRetiring = 0;
 
        dev->nRetiredBlocks++;
 }
@@ -527,20 +1059,6 @@ void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
        }
 }
 
-static void yaffs_ReportOddballBlocks(yaffs_Device *dev)
-{
-       int i;
-       for(i = dev->startBlock; i <= dev->endBlock; i++){
-               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
-               if(bi->needsRetiring || bi->gcPrioritise)
-                       T(YAFFS_TRACE_BAD_BLOCKS,(TSTR("yaffs block %d%s%s" TENDSTR),
-                               i,
-                               bi->needsRetiring ? " needs retiring" : "",
-                               bi->gcPrioritise ?  " gc prioritised" : ""));
-               
-       }
-}
-
 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk)
 {
 
@@ -573,7 +1091,7 @@ static __u16 yaffs_CalcNameSum(const YCHAR * name)
 
        YUCHAR *bname = (YUCHAR *) name;
        if (bname) {
-               while ((*bname) && (i <= YAFFS_MAX_NAME_LENGTH)) {
+               while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
 
 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
                        sum += yaffs_toupper(*bname) * i;
@@ -681,6 +1199,7 @@ static int yaffs_CreateTnodes(yaffs_Device * dev, int nTnodes)
                T(YAFFS_TRACE_ERROR,
                  (TSTR
                   ("yaffs: Could not add tnodes to management list" TENDSTR)));
+                  return YAFFS_FAIL;
 
        } else {
                tnl->tnodes = newTnodes;
@@ -805,7 +1324,7 @@ void yaffs_PutLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos, unsi
   }
 }
 
-__u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos)
+static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos)
 {
   __u32 *map = (__u32 *)tn;
   __u32 bitInMap;
@@ -1323,8 +1842,13 @@ static int yaffs_CreateFreeObjects(yaffs_Device * dev, int nObjects)
 
        /* make these things */
        newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
+       list = YMALLOC(sizeof(yaffs_ObjectList));
 
-       if (!newObjects) {
+       if (!newObjects || !list) {
+               if(newObjects)
+                       YFREE(newObjects);
+               if(list)
+                       YFREE(list);
                T(YAFFS_TRACE_ALLOCATE,
                  (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
                return YAFFS_FAIL;
@@ -1343,15 +1867,9 @@ static int yaffs_CreateFreeObjects(yaffs_Device * dev, int nObjects)
 
        /* Now add this bunch of Objects to a list for freeing up. */
 
-       list = YMALLOC(sizeof(yaffs_ObjectList));
-       if (!list) {
-               T(YAFFS_TRACE_ALLOCATE,
-                 (TSTR("Could not add objects to management list" TENDSTR)));
-       } else {
-               list->objects = newObjects;
-               list->next = dev->allocatedObjectList;
-               dev->allocatedObjectList = list;
-       }
+       list->objects = newObjects;
+       list->next = dev->allocatedObjectList;
+       dev->allocatedObjectList = list;
 
        return YAFFS_OK;
 }
@@ -1608,12 +2126,25 @@ yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
 {
 
        yaffs_Object *theObject;
+       yaffs_Tnode *tn;
 
        if (number < 0) {
                number = yaffs_CreateNewObjectNumber(dev);
        }
 
        theObject = yaffs_AllocateEmptyObject(dev);
+       if(!theObject)
+               return NULL;
+               
+       if(type == YAFFS_OBJECT_TYPE_FILE){
+               tn = yaffs_GetTnode(dev);
+               if(!tn){
+                       yaffs_FreeObject(theObject);
+                       return NULL;
+               }
+       }
+               
+       
 
        if (theObject) {
                theObject->fake = 0;
@@ -1640,8 +2171,7 @@ yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
                        theObject->variant.fileVariant.scannedFileSize = 0;
                        theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
                        theObject->variant.fileVariant.topLevel = 0;
-                       theObject->variant.fileVariant.top =
-                           yaffs_GetTnode(dev);
+                       theObject->variant.fileVariant.top = tn;
                        break;
                case YAFFS_OBJECT_TYPE_DIRECTORY:
                        INIT_LIST_HEAD(&theObject->variant.directoryVariant.
@@ -1686,7 +2216,8 @@ static YCHAR *yaffs_CloneString(const YCHAR * str)
 
        if (str && *str) {
                newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
-               yaffs_strcpy(newStr, str);
+               if(newStr)
+                       yaffs_strcpy(newStr, str);
        }
 
        return newStr;
@@ -1710,6 +2241,7 @@ static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
                                       const YCHAR * aliasString, __u32 rdev)
 {
        yaffs_Object *in;
+       YCHAR *str;
 
        yaffs_Device *dev = parent->myDev;
 
@@ -1719,6 +2251,16 @@ static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
        }
 
        in = yaffs_CreateNewObject(dev, -1, type);
+       
+       if(type == YAFFS_OBJECT_TYPE_SYMLINK){
+               str = yaffs_CloneString(aliasString);
+               if(!str){
+                       yaffs_FreeObject(in);
+                       return NULL;
+               }
+       }
+       
+       
 
        if (in) {
                in->chunkId = -1;
@@ -1750,8 +2292,7 @@ static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
 
                switch (type) {
                case YAFFS_OBJECT_TYPE_SYMLINK:
-                       in->variant.symLinkVariant.alias =
-                           yaffs_CloneString(aliasString);
+                       in->variant.symLinkVariant.alias = str;
                        break;
                case YAFFS_OBJECT_TYPE_HARDLINK:
                        in->variant.hardLinkVariant.equivalentObject =
@@ -1942,9 +2483,12 @@ static int yaffs_InitialiseBlocks(yaffs_Device * dev)
 {
        int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
        
+       dev->blockInfo = NULL;
+       dev->chunkBits = NULL;
+       
        dev->allocationBlock = -1;      /* force it to get a new one */
 
-       /* Todo we're assuming the malloc will pass. */
+       /* If the first allocation strategy fails, thry the alternate one */
        dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
        if(!dev->blockInfo){
                dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
@@ -1952,16 +2496,19 @@ static int yaffs_InitialiseBlocks(yaffs_Device * dev)
        }
        else
                dev->blockInfoAlt = 0;
+               
+       if(dev->blockInfo){
        
-       /* Set up dynamic blockinfo stuff. */
-       dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; // round up bytes
-       dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
-       if(!dev->chunkBits){
-               dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
-               dev->chunkBitsAlt = 1;
+               /* Set up dynamic blockinfo stuff. */
+               dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; /* round up bytes */
+               dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
+               if(!dev->chunkBits){
+                       dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
+                       dev->chunkBitsAlt = 1;
+               }
+               else
+                       dev->chunkBitsAlt = 0;
        }
-       else
-               dev->chunkBitsAlt = 0;
        
        if (dev->blockInfo && dev->chunkBits) {
                memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
@@ -1975,17 +2522,18 @@ static int yaffs_InitialiseBlocks(yaffs_Device * dev)
 
 static void yaffs_DeinitialiseBlocks(yaffs_Device * dev)
 {
-       if(dev->blockInfoAlt)
+       if(dev->blockInfoAlt && dev->blockInfo)
                YFREE_ALT(dev->blockInfo);
-       else
+       else if(dev->blockInfo)
                YFREE(dev->blockInfo);
+
        dev->blockInfoAlt = 0;
 
        dev->blockInfo = NULL;
        
-       if(dev->chunkBitsAlt)
+       if(dev->chunkBitsAlt && dev->chunkBits)
                YFREE_ALT(dev->chunkBits);
-       else
+       else if(dev->chunkBits)
                YFREE(dev->chunkBits);
        dev->chunkBitsAlt = 0;
        dev->chunkBits = NULL;
@@ -2042,10 +2590,9 @@ static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
        int i;
        int iterations;
        int dirtiest = -1;
-       int pagesInUse;
+       int pagesInUse = 0;
        int prioritised=0;
        yaffs_BlockInfo *bi;
-       static int nonAggressiveSkip = 0;
        int pendingPrioritisedExist = 0;
        
        /* First let's see if we need to grab a prioritised block */
@@ -2053,15 +2600,17 @@ static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
                for(i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++){
 
                        bi = yaffs_GetBlockInfo(dev, i);
-                       if(bi->gcPrioritise)
+                       //yaffs_VerifyBlock(dev,bi,i);
+                       
+                       if(bi->gcPrioritise) {
                                pendingPrioritisedExist = 1;
-                       if(bi->blockState == YAFFS_BLOCK_STATE_FULL &&
-                          bi->gcPrioritise &&
-                          yaffs_BlockNotDisqualifiedFromGC(dev, bi)){
-                               pagesInUse = (bi->pagesInUse - bi->softDeletions);
-                               dirtiest = i;
-                               prioritised = 1;
-                               aggressive = 1; /* Fool the non-aggressive skip logiv below */
+                               if(bi->blockState == YAFFS_BLOCK_STATE_FULL &&
+                                  yaffs_BlockNotDisqualifiedFromGC(dev, bi)){
+                                       pagesInUse = (bi->pagesInUse - bi->softDeletions);
+                                       dirtiest = i;
+                                       prioritised = 1;
+                                       aggressive = 1; /* Fool the non-aggressive skip logiv below */
+                               }
                        }
                }
                
@@ -2075,9 +2624,9 @@ static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
         * block has only a few pages in use.
         */
 
-       nonAggressiveSkip--;
+       dev->nonAggressiveSkip--;
 
-       if (!aggressive && (nonAggressiveSkip > 0)) {
+       if (!aggressive && (dev->nonAggressiveSkip > 0)) {
                return -1;
        }
 
@@ -2138,7 +2687,7 @@ static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
        dev->oldestDirtySequence = 0;
 
        if (dirtiest > 0) {
-               nonAggressiveSkip = 4;
+               dev->nonAggressiveSkip = 4;
        }
 
        return dirtiest;
@@ -2153,6 +2702,11 @@ static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
        /* If the block is still healthy erase it and mark as clean.
         * If the block has had a data failure, then retire it.
         */
+        
+       T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+               (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
+               blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
+               
        bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
 
        if (!bi->needsRetiring) {
@@ -2165,7 +2719,8 @@ static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
                }
        }
 
-       if (erasedOk && (yaffs_traceMask & YAFFS_TRACE_ERASE)) {
+       if (erasedOk && 
+           ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
                int i;
                for (i = 0; i < dev->nChunksPerBlock; i++) {
                        if (!yaffs_CheckChunkErased
@@ -2343,6 +2898,7 @@ static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
        int cleanups = 0;
        int i;
        int isCheckpointBlock;
+       int matchingChunk;
 
        int chunksBefore = yaffs_GetErasedChunks(dev);
        int chunksAfter;
@@ -2382,6 +2938,8 @@ static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
        } else {
 
                __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
+               
+               yaffs_VerifyBlock(dev,bi,block);
 
                for (chunkInBlock = 0, oldChunk = block * dev->nChunksPerBlock;
                     chunkInBlock < dev->nChunksPerBlock
@@ -2407,12 +2965,28 @@ static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
                                   ("Collecting page %d, %d %d %d " TENDSTR),
                                   chunkInBlock, tags.objectId, tags.chunkId,
                                   tags.byteCount));
+                                  
+                               if(object && !yaffs_SkipVerification(dev)){
+                                       if(tags.chunkId == 0)
+                                               matchingChunk = object->chunkId;
+                                       else if(object->softDeleted)
+                                               matchingChunk = oldChunk; /* Defeat the test */
+                                       else
+                                               matchingChunk = yaffs_FindChunkInFile(object,tags.chunkId,NULL);
+                                       
+                                       if(oldChunk != matchingChunk)
+                                               T(YAFFS_TRACE_ERROR,
+                                                 (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
+                                                 oldChunk,matchingChunk,tags.objectId, tags.chunkId));
+                                               
+                               }
 
                                if (!object) {
                                        T(YAFFS_TRACE_ERROR,
                                          (TSTR
-                                          ("page %d in gc has no object "
-                                           TENDSTR), oldChunk));
+                                          ("page %d in gc has no object: %d %d %d "
+                                           TENDSTR), oldChunk,
+                                           tags.objectId, tags.chunkId, tags.byteCount));
                                }
 
                                if (object && object->deleted
@@ -2469,6 +3043,8 @@ static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
                                                oh->shadowsObject = -1;
                                                tags.extraShadows = 0;
                                                tags.extraIsShrinkHeader = 0;
+                                               
+                                               yaffs_VerifyObjectHeader(object,oh,&tags,1);
                                        }
 
                                        newChunk =
@@ -2525,6 +3101,8 @@ static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
 
        }
 
+       yaffs_VerifyCollectedBlock(dev,bi,block);
+         
        if (chunksBefore >= (chunksAfter = yaffs_GetErasedChunks(dev))) {
                T(YAFFS_TRACE_GC,
                  (TSTR
@@ -2571,7 +3149,7 @@ static int yaffs_CheckGarbageCollection(yaffs_Device * dev)
                if(checkpointBlockAdjust < 0)
                        checkpointBlockAdjust = 0;
 
-               if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust)) {
+               if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
                        /* We need a block soon...*/
                        aggressive = 1;
                } else {
@@ -2899,11 +3477,18 @@ void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn)
 
        if (chunkId <= 0)
                return;
+               
 
        dev->nDeletions++;
        block = chunkId / dev->nChunksPerBlock;
        page = chunkId % dev->nChunksPerBlock;
 
+
+       if(!yaffs_CheckChunkBit(dev,block,page))
+               T(YAFFS_TRACE_VERIFY,
+                       (TSTR("Deleting invalid chunk %d"TENDSTR),
+                        chunkId));
+
        bi = yaffs_GetBlockInfo(dev, block);
 
        T(YAFFS_TRACE_DELETION,
@@ -3014,15 +3599,19 @@ int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
 
        int newChunkId;
        yaffs_ExtendedTags newTags;
+       yaffs_ExtendedTags oldTags;
 
        __u8 *buffer = NULL;
        YCHAR oldName[YAFFS_MAX_NAME_LENGTH + 1];
 
        yaffs_ObjectHeader *oh = NULL;
+       
+       yaffs_strcpy(oldName,"silly old name");
 
        if (!in->fake || force) {
 
                yaffs_CheckGarbageCollection(dev);
+               yaffs_CheckObjectDetailsLoaded(in);
 
                buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
                oh = (yaffs_ObjectHeader *) buffer;
@@ -3031,7 +3620,10 @@ int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
 
                if (prevChunkId >= 0) {
                        result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
-                                                       buffer, NULL);
+                                                       buffer, &oldTags);
+                       
+                       yaffs_VerifyObjectHeader(in,oh,&oldTags,0);
+                                                                               
                        memcpy(oldName, oh->name, sizeof(oh->name));
                }
 
@@ -3065,7 +3657,7 @@ int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
                if (name && *name) {
                        memset(oh->name, 0, sizeof(oh->name));
                        yaffs_strncpy(oh->name, name, YAFFS_MAX_NAME_LENGTH);
-               } else if (prevChunkId) {
+               } else if (prevChunkId>=0) {
                        memcpy(oh->name, oldName, sizeof(oh->name));
                } else {
                        memset(oh->name, 0, sizeof(oh->name));
@@ -3119,6 +3711,8 @@ int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
                newTags.extraShadows = (oh->shadowsObject > 0) ? 1 : 0;
                newTags.extraObjectType = in->variantType;
 
+               yaffs_VerifyObjectHeader(in,oh,&newTags,1);
+
                /* Create new chunk in NAND */
                newChunkId =
                    yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
@@ -3441,6 +4035,9 @@ static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in)
 static int yaffs_WriteCheckpointValidityMarker(yaffs_Device *dev,int head)
 {
        yaffs_CheckpointValidity cp;
+       
+       memset(&cp,0,sizeof(cp));
+       
        cp.structType = sizeof(cp);
        cp.magic = YAFFS_MAGIC;
        cp.version = YAFFS_CHECKPOINT_VERSION;
@@ -3677,12 +4274,15 @@ static int yaffs_ReadCheckpointTnodes(yaffs_Object *obj)
        yaffs_Device *dev = obj->myDev;
        yaffs_FileStructure *fileStructPtr = &obj->variant.fileVariant;
        yaffs_Tnode *tn;
+       int nread = 0;
        
        ok = (yaffs_CheckpointRead(dev,&baseChunk,sizeof(baseChunk)) == sizeof(baseChunk));
        
        while(ok && (~baseChunk)){
+               nread++;
                /* Read level 0 tnode */
                
+               
                /* printf("read  tnode at %d\n",baseChunk); */
                tn = yaffs_GetTnodeRaw(dev);
                if(tn)
@@ -3696,6 +4296,7 @@ static int yaffs_ReadCheckpointTnodes(yaffs_Object *obj)
                                                        fileStructPtr,
                                                        baseChunk,
                                                        tn) ? 1 : 0;
+                                                       
                }
                        
                if(ok)
@@ -3703,6 +4304,10 @@ static int yaffs_ReadCheckpointTnodes(yaffs_Object *obj)
                
        }
 
+       T(YAFFS_TRACE_CHECKPOINT,(
+               TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
+               nread,baseChunk,ok));
+
        return ok ? 1 : 0;      
 }
  
@@ -3763,16 +4368,18 @@ static int yaffs_ReadCheckpointObjects(yaffs_Device *dev)
        while(ok && !done) {
                ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
                if(cp.structType != sizeof(cp)) {
-                       /* printf("structure parsing failed\n"); */
+                       T(YAFFS_TRACE_CHECKPOINT,(TSTR("struct size %d instead of %d ok %d"TENDSTR),
+                               cp.structType,sizeof(cp),ok));
                        ok = 0;
                }
                        
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("Checkpoint read object %d parent %d type %d chunk %d " TENDSTR),
+                       cp.objectId,cp.parentId,cp.variantType,cp.chunkId));
+                       
                if(ok && cp.objectId == ~0)
                        done = 1;
                else if(ok){
                        obj = yaffs_FindOrCreateObjectByNumber(dev,cp.objectId, cp.variantType);
-                       T(YAFFS_TRACE_CHECKPOINT,(TSTR("Checkpoint read object %d parent %d type %d chunk %d obj addr %x" TENDSTR),
-                               cp.objectId,cp.parentId,cp.variantType,cp.chunkId,(unsigned) obj));
                        if(obj) {
                                yaffs_CheckpointObjectToObject(obj,&cp);
                                if(obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
@@ -3794,22 +4401,76 @@ static int yaffs_ReadCheckpointObjects(yaffs_Device *dev)
        return ok ? 1 : 0;
 }
 
-static int yaffs_WriteCheckpointData(yaffs_Device *dev)
+static int yaffs_WriteCheckpointSum(yaffs_Device *dev)
 {
+       __u32 checkpointSum;
+       int ok;
+       
+       yaffs_GetCheckpointSum(dev,&checkpointSum);
+       
+       ok = (yaffs_CheckpointWrite(dev,&checkpointSum,sizeof(checkpointSum)) == sizeof(checkpointSum));
+       
+       if(!ok)
+               return 0;
+       
+       return 1;
+}
 
+static int yaffs_ReadCheckpointSum(yaffs_Device *dev)
+{
+       __u32 checkpointSum0;
+       __u32 checkpointSum1;
        int ok;
        
-       ok = yaffs_CheckpointOpen(dev,1);
+       yaffs_GetCheckpointSum(dev,&checkpointSum0);
+       
+       ok = (yaffs_CheckpointRead(dev,&checkpointSum1,sizeof(checkpointSum1)) == sizeof(checkpointSum1));
+       
+       if(!ok)
+               return 0;
+               
+       if(checkpointSum0 != checkpointSum1)
+               return 0;
+       
+       return 1;
+}
+
+
+static int yaffs_WriteCheckpointData(yaffs_Device *dev)
+{
+
+       int ok = 1;
        
+       if(dev->skipCheckpointWrite || !dev->isYaffs2){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("skipping checkpoint write" TENDSTR)));
+               ok = 0;
+       }
+               
        if(ok)
+               ok = yaffs_CheckpointOpen(dev,1);
+       
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint validity" TENDSTR)));
                ok = yaffs_WriteCheckpointValidityMarker(dev,1);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint device" TENDSTR)));
                ok = yaffs_WriteCheckpointDevice(dev);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint objects" TENDSTR)));
                ok = yaffs_WriteCheckpointObjects(dev);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint validity" TENDSTR)));
                ok = yaffs_WriteCheckpointValidityMarker(dev,0);
-               
+       }
+       
+       if(ok){
+               ok = yaffs_WriteCheckpointSum(dev);
+       }
+       
+       
        if(!yaffs_CheckpointClose(dev))
                 ok = 0;
                 
@@ -3823,20 +4484,37 @@ static int yaffs_WriteCheckpointData(yaffs_Device *dev)
 
 static int yaffs_ReadCheckpointData(yaffs_Device *dev)
 {
-       int ok;
+       int ok = 1;
        
-       ok = yaffs_CheckpointOpen(dev,0); /* open for read */
+       if(dev->skipCheckpointRead || !dev->isYaffs2){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("skipping checkpoint read" TENDSTR)));
+               ok = 0;
+       }
        
        if(ok)
+               ok = yaffs_CheckpointOpen(dev,0); /* open for read */
+       
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint validity" TENDSTR)));   
                ok = yaffs_ReadCheckpointValidityMarker(dev,1);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint device" TENDSTR)));
                ok = yaffs_ReadCheckpointDevice(dev);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint objects" TENDSTR)));    
                ok = yaffs_ReadCheckpointObjects(dev);
-       if(ok)
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint validity" TENDSTR)));
                ok = yaffs_ReadCheckpointValidityMarker(dev,0);
-               
-
+       }
+       
+       if(ok){
+               ok = yaffs_ReadCheckpointSum(dev);
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint checksum %d" TENDSTR),ok));
+       }
 
        if(!yaffs_CheckpointClose(dev))
                ok = 0;
@@ -3864,13 +4542,19 @@ static void yaffs_InvalidateCheckpoint(yaffs_Device *dev)
 
 int yaffs_CheckpointSave(yaffs_Device *dev)
 {
-       yaffs_ReportOddballBlocks(dev);
+
        T(YAFFS_TRACE_CHECKPOINT,(TSTR("save entry: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
 
-       if(!dev->isCheckpointed)
+       yaffs_VerifyObjects(dev);
+       yaffs_VerifyBlocks(dev);
+       yaffs_VerifyFreeChunks(dev);
+
+       if(!dev->isCheckpointed) {
+               yaffs_InvalidateCheckpoint(dev);
                yaffs_WriteCheckpointData(dev);
+       }
        
-       T(YAFFS_TRACE_CHECKPOINT,(TSTR("save exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
+       T(YAFFS_TRACE_ALWAYS,(TSTR("save exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
 
        return dev->isCheckpointed;
 }
@@ -3879,13 +4563,17 @@ int yaffs_CheckpointRestore(yaffs_Device *dev)
 {
        int retval;
        T(YAFFS_TRACE_CHECKPOINT,(TSTR("restore entry: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
-       
+               
        retval = yaffs_ReadCheckpointData(dev);
 
+       if(dev->isCheckpointed){
+               yaffs_VerifyObjects(dev);
+               yaffs_VerifyBlocks(dev);
+               yaffs_VerifyFreeChunks(dev);
+       }
+
        T(YAFFS_TRACE_CHECKPOINT,(TSTR("restore exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
        
-       yaffs_ReportOddballBlocks(dev);
-       
        return retval;
 }
 
@@ -4262,7 +4950,7 @@ int yaffs_ResizeFile(yaffs_Object * in, loff_t newSize)
        int newFullChunks;
        
        yaffs_Device *dev = in->myDev;
-       
+
        yaffs_AddrToChunk(dev, newSize, &newFullChunks, &newSizeOfPartialChunk);
 
        yaffs_FlushFilesChunkCache(in);
@@ -4303,7 +4991,13 @@ int yaffs_ResizeFile(yaffs_Object * in, loff_t newSize)
                in->variant.fileVariant.fileSize = newSize;
 
                yaffs_PruneFileStructure(dev, &in->variant.fileVariant);
+       } else {
+               /* newsSize > oldFileSize */
+               in->variant.fileVariant.fileSize = newSize;
        }
+
+               
+       
        /* Write a new object header.
         * show we've shrunk the file, if need be
         * Do this only if the file is not in the deleted directories.
@@ -4314,7 +5008,7 @@ int yaffs_ResizeFile(yaffs_Object * in, loff_t newSize)
                                         (newSize < oldFileSize) ? 1 : 0, 0);
        }
 
-       return newSize;
+       return YAFFS_OK;
 }
 
 loff_t yaffs_GetFileSize(yaffs_Object * obj)
@@ -4367,7 +5061,7 @@ static int yaffs_DoGenericObjectDeletion(yaffs_Object * in)
 
        if (in->myDev->isYaffs2 && (in->parent != in->myDev->deletedDir)) {
                /* Move to the unlinked directory so we have a record that it was deleted. */
-               yaffs_ChangeObjectName(in, in->myDev->deletedDir, NULL, 0, 0);
+               yaffs_ChangeObjectName(in, in->myDev->deletedDir,"deleted", 0, 0);
 
        }
 
@@ -4405,7 +5099,7 @@ static int yaffs_UnlinkFile(yaffs_Object * in)
                if (immediateDeletion) {
                        retVal =
                            yaffs_ChangeObjectName(in, in->myDev->deletedDir,
-                                                  NULL, 0, 0);
+                                                  "deleted", 0, 0);
                        T(YAFFS_TRACE_TRACING,
                          (TSTR("yaffs: immediate deletion of file %d" TENDSTR),
                           in->objectId));
@@ -4418,7 +5112,7 @@ static int yaffs_UnlinkFile(yaffs_Object * in)
                } else {
                        retVal =
                            yaffs_ChangeObjectName(in, in->myDev->unlinkedDir,
-                                                  NULL, 0, 0);
+                                                  "unlinked", 0, 0);
                }
 
        }
@@ -4679,13 +5373,15 @@ static int yaffs_Scan(yaffs_Device * dev)
        int deleted;
        yaffs_BlockState state;
        yaffs_Object *hardList = NULL;
-       yaffs_Object *hl;
        yaffs_BlockInfo *bi;
        int sequenceNumber;
        yaffs_ObjectHeader *oh;
        yaffs_Object *in;
        yaffs_Object *parent;
        int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
+       
+       int alloc_failed = 0;
+       
 
        __u8 *chunkData;
 
@@ -4709,6 +5405,8 @@ static int yaffs_Scan(yaffs_Device * dev)
 
        if (dev->isYaffs2) {
                blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));
+               if(!blockIndex)
+                       return YAFFS_FAIL;
        }
 
        /* Scan all the blocks to determine their state */
@@ -4790,7 +5488,7 @@ static int yaffs_Scan(yaffs_Device * dev)
        }
 
        /* For each block.... */
-       for (blockIterator = startIterator; blockIterator <= endIterator;
+       for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
             blockIterator++) {
 
                if (dev->isYaffs2) {
@@ -4806,7 +5504,7 @@ static int yaffs_Scan(yaffs_Device * dev)
                deleted = 0;
 
                /* For each chunk in each block that needs scanning....*/
-               for (c = 0; c < dev->nChunksPerBlock &&
+               for (c = 0; !alloc_failed && c < dev->nChunksPerBlock &&
                     state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
                        /* Read the tags and decide what to do */
                        chunk = blk * dev->nChunksPerBlock + c;
@@ -4874,12 +5572,20 @@ static int yaffs_Scan(yaffs_Device * dev)
                                /* PutChunkIntoFile checks for a clash (two data chunks with
                                 * the same chunkId).
                                 */
-                               yaffs_PutChunkIntoFile(in, tags.chunkId, chunk,
-                                                      1);
+                                
+                               if(!in)
+                                       alloc_failed = 1;
+
+                               if(in){
+                                       if(!yaffs_PutChunkIntoFile(in, tags.chunkId, chunk,1))
+                                               alloc_failed = 1;
+                               }
+                               
                                endpos =
                                    (tags.chunkId - 1) * dev->nDataBytesPerChunk +
                                    tags.byteCount;
-                               if (in->variantType == YAFFS_OBJECT_TYPE_FILE
+                               if (in && 
+                                   in->variantType == YAFFS_OBJECT_TYPE_FILE
                                    && in->variant.fileVariant.scannedFileSize <
                                    endpos) {
                                        in->variant.fileVariant.
@@ -4924,14 +5630,17 @@ static int yaffs_Scan(yaffs_Device * dev)
                                                                      objectId,
                                                                      oh->type);
 
-                               if (oh->shadowsObject > 0) {
+                               if(!in)
+                                       alloc_failed = 1;
+                                       
+                               if (in && oh->shadowsObject > 0) {
                                        yaffs_HandleShadowedObject(dev,
                                                                   oh->
                                                                   shadowsObject,
                                                                   0);
                                }
 
-                               if (in->valid) {
+                               if (in && in->valid) {
                                        /* We have already filled this one. We have a duplicate and need to resolve it. */
 
                                        unsigned existingSerial = in->serial;
@@ -4952,7 +5661,7 @@ static int yaffs_Scan(yaffs_Device * dev)
                                        }
                                }
 
-                               if (!in->valid &&
+                               if (in && !in->valid &&
                                    (tags.objectId == YAFFS_OBJECTID_ROOT ||
                                     tags.objectId == YAFFS_OBJECTID_LOSTNFOUND)) {
                                        /* We only load some info, don't fiddle with directory structure */
@@ -4977,7 +5686,7 @@ static int yaffs_Scan(yaffs_Device * dev)
 #endif
                                        in->chunkId = chunk;
 
-                               } else if (!in->valid) {
+                               } else if (in && !in->valid) {
                                        /* we need to load this info */
 
                                        in->valid = 1;
@@ -5086,9 +5795,10 @@ static int yaffs_Scan(yaffs_Device * dev)
                                                /* Do nothing */
                                                break;
                                        case YAFFS_OBJECT_TYPE_SYMLINK: 
-                                               in->variant.symLinkVariant.
-                                                   alias =
+                                               in->variant.symLinkVariant.alias =
                                                    yaffs_CloneString(oh->alias);
+                                               if(!in->variant.symLinkVariant.alias)
+                                                       alloc_failed = 1;
                                                break;
                                        }
 
@@ -5150,7 +5860,12 @@ static int yaffs_Scan(yaffs_Device * dev)
 
        yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
 
+       if(alloc_failed){
+               return YAFFS_FAIL;
+       }
+       
        T(YAFFS_TRACE_SCAN, (TSTR("yaffs_Scan ends" TENDSTR)));
+       
 
        return YAFFS_OK;
 }
@@ -5162,13 +5877,17 @@ static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in)
        yaffs_Device *dev = in->myDev;
        yaffs_ExtendedTags tags;
        int result;
-       
+       int alloc_failed = 0;
+
+       if(!in)
+               return;
+               
 #if 0
        T(YAFFS_TRACE_SCAN,(TSTR("details for object %d %s loaded" TENDSTR),
                in->objectId,
                in->lazyLoaded ? "not yet" : "already"));
 #endif
-               
+
        if(in->lazyLoaded){
                in->lazyLoaded = 0;
                chunkData = yaffs_GetTempBuffer(dev, __LINE__);
@@ -5195,9 +5914,12 @@ static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in)
 #endif
                yaffs_SetObjectName(in, oh->name);
                
-               if(in->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+               if(in->variantType == YAFFS_OBJECT_TYPE_SYMLINK){
                         in->variant.symLinkVariant.alias =
                                                    yaffs_CloneString(oh->alias);
+                       if(!in->variant.symLinkVariant.alias)
+                               alloc_failed = 1; /* Not returned to caller */
+               }
                                                    
                yaffs_ReleaseTempBuffer(dev,chunkData, __LINE__);
        }
@@ -5231,6 +5953,7 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
        int isShrink;
        int foundChunksInBlock;
        int equivalentObjectId;
+       int alloc_failed = 0;
        
 
        yaffs_BlockIndex *blockIndex = NULL;
@@ -5263,6 +5986,8 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                return YAFFS_FAIL;
        }
        
+       dev->blocksInCheckpoint = 0;
+       
        chunkData = yaffs_GetTempBuffer(dev, __LINE__);
 
        /* Scan all the blocks to determine their state */
@@ -5286,7 +6011,7 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
 
                
                if(state == YAFFS_BLOCK_STATE_CHECKPOINT){
-                       /* todo .. fix free space ? */
+                       dev->blocksInCheckpoint++;
                        
                } else if (state == YAFFS_BLOCK_STATE_DEAD) {
                        T(YAFFS_TRACE_BAD_BLOCKS,
@@ -5333,7 +6058,7 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
 #ifndef CONFIG_YAFFS_USE_OWN_SORT
        {
                /* Use qsort now. */
-               qsort(blockIndex, nBlocksToScan, sizeof(yaffs_BlockIndex), ybicmp);
+               yaffs_qsort(blockIndex, nBlocksToScan, sizeof(yaffs_BlockIndex), ybicmp);
        }
 #else
        {
@@ -5364,7 +6089,7 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
          (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));
 
        /* For each block.... backwards */
-       for (blockIterator = endIterator; blockIterator >= startIterator;
+       for (blockIterator = endIterator; !alloc_failed && blockIterator >= startIterator;
             blockIterator--) {
                /* Cooperative multitasking! This loop can run for so
                   long that watchdog timers expire. */
@@ -5374,18 +6099,22 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                blk = blockIndex[blockIterator].block;
 
                bi = yaffs_GetBlockInfo(dev, blk);
+               
+               
                state = bi->blockState;
 
                deleted = 0;
 
                /* For each chunk in each block that needs scanning.... */
                foundChunksInBlock = 0;
-               for (c = dev->nChunksPerBlock - 1; c >= 0 &&
+               for (c = dev->nChunksPerBlock - 1; 
+                    !alloc_failed && c >= 0 &&
                     (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
                      state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
                        /* Scan backwards... 
                         * Read the tags and decide what to do
                         */
+                       
                        chunk = blk * dev->nChunksPerBlock + c;
 
                        result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
@@ -5412,39 +6141,41 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                                        state = YAFFS_BLOCK_STATE_EMPTY;
                                        dev->nErasedBlocks++;
                                } else {
-                                       /* this is the block being allocated from */
-                                       if (state ==
-                                           YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
-                                               T(YAFFS_TRACE_SCAN,
-                                                 (TSTR
-                                                  (" Allocating from %d %d"
-                                                   TENDSTR), blk, c));
+                                       if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+                                           state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                                               if(dev->sequenceNumber == bi->sequenceNumber) {
+                                                       /* this is the block being allocated from */
+                                               
+                                                       T(YAFFS_TRACE_SCAN,
+                                                         (TSTR
+                                                          (" Allocating from %d %d"
+                                                           TENDSTR), blk, c));
+
+                                                       state = YAFFS_BLOCK_STATE_ALLOCATING;
+                                                       dev->allocationBlock = blk;
+                                                       dev->allocationPage = c;
+                                                       dev->allocationBlockFinder = blk;       
+                                               }
+                                               else {
+                                                       /* This is a partially written block that is not
+                                                        * the current allocation block. This block must have
+                                                        * had a write failure, so set up for retirement.
+                                                        */
+                                                 
+                                                        bi->needsRetiring = 1;
+                                                        bi->gcPrioritise = 1;
+                                                                                                        
+                                                        T(YAFFS_TRACE_ALWAYS,
+                                                        (TSTR("Partially written block %d being set for retirement" TENDSTR),
+                                                        blk));
+                                               }
+
                                        }
-                                       state = YAFFS_BLOCK_STATE_ALLOCATING;
-                                       dev->allocationBlock = blk;
-                                       dev->allocationPage = c;
-                                       dev->allocationBlockFinder = blk;       
-                                       /* Set it to here to encourage the allocator to 
-                                        *  go forth from here.
-                                        */
                                         
-                                       /* Yaffs2 sanity check:
-                                        * This should be the one with the highest sequence number
-                                        */
-                                       if (dev->isYaffs2
-                                           && (dev->sequenceNumber !=
-                                               bi->sequenceNumber)) {
-                                               T(YAFFS_TRACE_ALWAYS,
-                                                 (TSTR
-                                                  ("yaffs: Allocation block %d was not highest sequence "
-                                                   "id: block seq = %d, dev seq = %d"
-                                                   TENDSTR), blk,
-                                                  bi->sequenceNumber,
-                                                  dev->sequenceNumber));
-                                       }
                                }
 
                                dev->nFreeChunks++;
+                               
                        } else if (tags.chunkId > 0) {
                                /* chunkId > 0 so it is a data chunk... */
                                unsigned int endpos;
@@ -5461,12 +6192,20 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                                                                      tags.
                                                                      objectId,
                                                                      YAFFS_OBJECT_TYPE_FILE);
-                               if (in->variantType == YAFFS_OBJECT_TYPE_FILE
+                               if(!in){
+                                       /* Out of memory */
+                                       alloc_failed = 1;
+                               }
+                               
+                               if (in &&
+                                   in->variantType == YAFFS_OBJECT_TYPE_FILE
                                    && chunkBase <
                                    in->variant.fileVariant.shrinkSize) {
                                        /* This has not been invalidated by a resize */
-                                       yaffs_PutChunkIntoFile(in, tags.chunkId,
-                                                              chunk, -1);
+                                       if(!yaffs_PutChunkIntoFile(in, tags.chunkId,
+                                                              chunk, -1)){
+                                               alloc_failed = 1;
+                                       }
 
                                        /* File size is calculated by looking at the data chunks if we have not 
                                         * seen an object header yet. Stop this practice once we find an object header.
@@ -5487,7 +6226,7 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                                                    scannedFileSize;
                                        }
 
-                               } else {
+                               } else if(in) {
                                        /* This chunk has been invalidated by a resize, so delete */
                                        yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
 
@@ -5775,16 +6514,21 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
                                                /* Do nothing */
                                                break;
                                        case YAFFS_OBJECT_TYPE_SYMLINK:
-                                               if(oh)
+                                               if(oh){
                                                   in->variant.symLinkVariant.alias =
                                                    yaffs_CloneString(oh->
                                                                      alias);
+                                                  if(!in->variant.symLinkVariant.alias)
+                                                       alloc_failed = 1;
+                                               }
                                                break;
                                        }
 
                                }
+                               
                        }
-               }
+
+               } /* End of scanning for each chunk */
 
                if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
                        /* If we got this far while scanning, then the block is fully allocated. */
@@ -5847,6 +6591,10 @@ static int yaffs_ScanBackwards(yaffs_Device * dev)
        }
 
        yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
+       
+       if(alloc_failed){
+               return YAFFS_FAIL;
+       }
 
        T(YAFFS_TRACE_SCAN, (TSTR("yaffs_ScanBackwards ends" TENDSTR)));
 
@@ -5954,7 +6702,7 @@ yaffs_Object *yaffs_FindObjectByName(yaffs_Object * directory,
                                 */
                                yaffs_GetObjectName(l, buffer,
                                                    YAFFS_MAX_NAME_LENGTH);
-                               if (yaffs_strcmp(name, buffer) == 0) {
+                               if (yaffs_strncmp(name, buffer,YAFFS_MAX_NAME_LENGTH) == 0) {
                                        return l;
                                }
 
@@ -6010,6 +6758,7 @@ yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object * obj)
        if (obj && obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
                /* We want the object id of the equivalent object, not this one */
                obj = obj->variant.hardLinkVariant.equivalentObject;
+               yaffs_CheckObjectDetailsLoaded(obj);
        }
        return obj;
 
@@ -6247,7 +6996,7 @@ static int yaffs_CheckDevFunctions(const yaffs_Device * dev)
 }
 
 
-static void yaffs_CreateInitialDirectories(yaffs_Device *dev)
+static int yaffs_CreateInitialDirectories(yaffs_Device *dev)
 {
        /* Initialise the unlinked, deleted, root and lost and found directories */
        
@@ -6256,6 +7005,7 @@ static void yaffs_CreateInitialDirectories(yaffs_Device *dev)
 
        dev->unlinkedDir =
            yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+       
        dev->deletedDir =
            yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
 
@@ -6265,11 +7015,18 @@ static void yaffs_CreateInitialDirectories(yaffs_Device *dev)
        dev->lostNFoundDir =
            yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_LOSTNFOUND,
                                      YAFFS_LOSTNFOUND_MODE | S_IFDIR);
-       yaffs_AddObjectToDirectory(dev->rootDir, dev->lostNFoundDir);
+       
+       if(dev->lostNFoundDir && dev->rootDir && dev->unlinkedDir && dev->deletedDir){
+               yaffs_AddObjectToDirectory(dev->rootDir, dev->lostNFoundDir);
+               return YAFFS_OK;
+       }
+       
+       return YAFFS_FAIL;
 }
 
 int yaffs_GutsInitialise(yaffs_Device * dev)
 {
+       int init_failed = 0;
        unsigned x;
        int bits;
 
@@ -6441,71 +7198,111 @@ int yaffs_GutsInitialise(yaffs_Device * dev)
        dev->hasPendingPrioritisedGCs = 1; /* Assume the worst for now, will get fixed on first GC */
 
        /* Initialise temporary buffers and caches. */
-       {
-               int i;
-               for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
-                       dev->tempBuffer[i].line = 0;    /* not in use */
-                       dev->tempBuffer[i].buffer =
-                           YMALLOC_DMA(dev->nDataBytesPerChunk);
-               }
-       }
+       if(!yaffs_InitialiseTempBuffers(dev))
+               init_failed = 1;
        
-       if (dev->nShortOpCaches > 0) {
+       dev->srCache = NULL;
+       dev->gcCleanupList = NULL;
+       
+       
+       if (!init_failed &&
+           dev->nShortOpCaches > 0) {
                int i;
+               __u8 *buf;
+               int srCacheBytes = dev->nShortOpCaches * sizeof(yaffs_ChunkCache);
 
                if (dev->nShortOpCaches > YAFFS_MAX_SHORT_OP_CACHES) {
                        dev->nShortOpCaches = YAFFS_MAX_SHORT_OP_CACHES;
                }
 
-               dev->srCache =
-                   YMALLOC(dev->nShortOpCaches * sizeof(yaffs_ChunkCache));
-
-               for (i = 0; i < dev->nShortOpCaches; i++) {
+               buf = dev->srCache =  YMALLOC(srCacheBytes);
+                   
+               if(dev->srCache)
+                       memset(dev->srCache,0,srCacheBytes);
+                  
+               for (i = 0; i < dev->nShortOpCaches && buf; i++) {
                        dev->srCache[i].object = NULL;
                        dev->srCache[i].lastUse = 0;
                        dev->srCache[i].dirty = 0;
-                       dev->srCache[i].data = YMALLOC_DMA(dev->nDataBytesPerChunk);
+                       dev->srCache[i].data = buf = YMALLOC_DMA(dev->nDataBytesPerChunk);
                }
+               if(!buf)
+                       init_failed = 1;
+                       
                dev->srLastUse = 0;
        }
 
        dev->cacheHits = 0;
        
-       dev->gcCleanupList = YMALLOC(dev->nChunksPerBlock * sizeof(__u32));
+       if(!init_failed){
+               dev->gcCleanupList = YMALLOC(dev->nChunksPerBlock * sizeof(__u32));
+               if(!dev->gcCleanupList)
+                       init_failed = 1;
+       }
 
        if (dev->isYaffs2) {
                dev->useHeaderFileSize = 1;
        }
-
-       yaffs_InitialiseBlocks(dev);
+       if(!init_failed && !yaffs_InitialiseBlocks(dev))
+               init_failed = 1;
+               
        yaffs_InitialiseTnodes(dev);
        yaffs_InitialiseObjects(dev);
 
-       yaffs_CreateInitialDirectories(dev);
+       if(!init_failed && !yaffs_CreateInitialDirectories(dev))
+               init_failed = 1;
 
 
-       /* Now scan the flash. */
-       if (dev->isYaffs2) {
-               if(yaffs_CheckpointRestore(dev)) {
-                       T(YAFFS_TRACE_ALWAYS,
-                         (TSTR("yaffs: restored from checkpoint" TENDSTR)));
-               } else {
+       if(!init_failed){
+               /* Now scan the flash. */
+               if (dev->isYaffs2) {
+                       if(yaffs_CheckpointRestore(dev)) {
+                               T(YAFFS_TRACE_ALWAYS,
+                                 (TSTR("yaffs: restored from checkpoint" TENDSTR)));
+                       } else {
 
-                       /* Clean up the mess caused by an aborted checkpoint load 
-                        * and scan backwards. 
-                        */
-                       yaffs_DeinitialiseBlocks(dev);
-                       yaffs_DeinitialiseTnodes(dev);
-                       yaffs_DeinitialiseObjects(dev);
-                       yaffs_InitialiseBlocks(dev);
-                       yaffs_InitialiseTnodes(dev);
-                       yaffs_InitialiseObjects(dev);
-                       yaffs_CreateInitialDirectories(dev);
-
-                       yaffs_ScanBackwards(dev);
-               }
-       }else
-               yaffs_Scan(dev);
+                               /* Clean up the mess caused by an aborted checkpoint load 
+                                * and scan backwards. 
+                                */
+                               yaffs_DeinitialiseBlocks(dev);
+                               yaffs_DeinitialiseTnodes(dev);
+                               yaffs_DeinitialiseObjects(dev);
+                               
+                       
+                               dev->nErasedBlocks = 0;
+                               dev->nFreeChunks = 0;
+                               dev->allocationBlock = -1;
+                               dev->allocationPage = -1;
+                               dev->nDeletedFiles = 0;
+                               dev->nUnlinkedFiles = 0;
+                               dev->nBackgroundDeletions = 0;
+                               dev->oldestDirtySequence = 0;
+
+                               if(!init_failed && !yaffs_InitialiseBlocks(dev))
+                                       init_failed = 1;
+                                       
+                               yaffs_InitialiseTnodes(dev);
+                               yaffs_InitialiseObjects(dev);
+
+                               if(!init_failed && !yaffs_CreateInitialDirectories(dev))
+                                       init_failed = 1;
+
+                               if(!init_failed && !yaffs_ScanBackwards(dev))
+                                       init_failed = 1;
+                       }
+               }else
+                       if(!yaffs_Scan(dev))
+                               init_failed = 1;
+       }
+               
+       if(init_failed){
+               /* Clean up the mess */
+               T(YAFFS_TRACE_TRACING,
+                 (TSTR("yaffs: yaffs_GutsInitialise() aborted.\n" TENDSTR)));
+
+               yaffs_Deinitialise(dev);
+               return YAFFS_FAIL;
+       }
 
        /* Zero out stats */
        dev->nPageReads = 0;
@@ -6517,6 +7314,8 @@ int yaffs_GutsInitialise(yaffs_Device * dev)
        dev->nRetiredBlocks = 0;
 
        yaffs_VerifyFreeChunks(dev);
+       yaffs_VerifyBlocks(dev);
+       
 
        T(YAFFS_TRACE_TRACING,
          (TSTR("yaffs: yaffs_GutsInitialise() done.\n" TENDSTR)));
@@ -6532,13 +7331,17 @@ void yaffs_Deinitialise(yaffs_Device * dev)
                yaffs_DeinitialiseBlocks(dev);
                yaffs_DeinitialiseTnodes(dev);
                yaffs_DeinitialiseObjects(dev);
-               if (dev->nShortOpCaches > 0) {
+               if (dev->nShortOpCaches > 0 &&
+                   dev->srCache) {
 
                        for (i = 0; i < dev->nShortOpCaches; i++) {
-                               YFREE(dev->srCache[i].data);
+                               if(dev->srCache[i].data)
+                                       YFREE(dev->srCache[i].data);
+                               dev->srCache[i].data = NULL;
                        }
 
                        YFREE(dev->srCache);
+                       dev->srCache = NULL;
                }
 
                YFREE(dev->gcCleanupList);
@@ -6629,9 +7432,15 @@ static int yaffs_freeVerificationFailures;
 
 static void yaffs_VerifyFreeChunks(yaffs_Device * dev)
 {
-       int counted = yaffs_CountFreeChunks(dev);
+       int counted;
+       int difference;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+       
+       counted = yaffs_CountFreeChunks(dev);
 
-       int difference = dev->nFreeChunks - counted;
+       difference = dev->nFreeChunks - counted;
 
        if (difference) {
                T(YAFFS_TRACE_ALWAYS,