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yaffs_guts.c

/*
 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
 *
 * Copyright (C) 2002-2007 Aleph One Ltd.
 *   for Toby Churchill Ltd and Brightstar Engineering
 *
 * Created by Charles Manning <charles@aleph1.co.uk>
 *
 * 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.
 */

/* XXX U-BOOT XXX */
#include <common.h>

const char *yaffs_guts_c_version =
    "$Id: yaffs_guts.c,v 1.52 2007/10/16 00:45:05 charles Exp $";

#include "yportenv.h"
#include "linux/stat.h"

#include "yaffsinterface.h"
#include "yaffsfs.h"
#include "yaffs_guts.h"
#include "yaffs_tagsvalidity.h"

#include "yaffs_tagscompat.h"
#ifndef  CONFIG_YAFFS_USE_OWN_SORT
#include "yaffs_qsort.h"
#endif
#include "yaffs_nand.h"

#include "yaffs_checkptrw.h"

#include "yaffs_nand.h"
#include "yaffs_packedtags2.h"

#include "malloc.h"

#ifdef CONFIG_YAFFS_WINCE
void yfsd_LockYAFFS(BOOL fsLockOnly);
void yfsd_UnlockYAFFS(BOOL fsLockOnly);
#endif

#define YAFFS_PASSIVE_GC_CHUNKS 2

#include "yaffs_ecc.h"


/* Robustification (if it ever comes about...) */
static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND);
static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk);
static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
                             const __u8 * data,
                             const yaffs_ExtendedTags * tags);
static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
                            const yaffs_ExtendedTags * tags);

/* Other local prototypes */
static int yaffs_UnlinkObject( yaffs_Object *obj);
static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);

static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList);

static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device * dev,
                                   const __u8 * buffer,
                                   yaffs_ExtendedTags * tags,
                                   int useReserve);
static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
                          int chunkInNAND, int inScan);

static yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
                                 yaffs_ObjectType type);
static void yaffs_AddObjectToDirectory(yaffs_Object * directory,
                               yaffs_Object * obj);
static int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name,
                            int force, int isShrink, int shadows);
static void yaffs_RemoveObjectFromDirectory(yaffs_Object * obj);
static int yaffs_CheckStructures(void);
static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
                        int chunkOffset, int *limit);
static int yaffs_DoGenericObjectDeletion(yaffs_Object * in);

static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device * dev, int blockNo);

static __u8 *yaffs_GetTempBuffer(yaffs_Device * dev, int lineNo);
static void yaffs_ReleaseTempBuffer(yaffs_Device * dev, __u8 * buffer,
                            int lineNo);

static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
                          int chunkInNAND);

static int yaffs_UnlinkWorker(yaffs_Object * obj);
static void yaffs_DestroyObject(yaffs_Object * obj);

static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
                     int chunkInObject);

loff_t yaffs_GetFileSize(yaffs_Object * obj);

static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr);

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
#define yaffs_CheckFileSanity(in)
#endif

static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in);
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 */

static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, __u32 *chunk, __u32 *offset)
{
      if(dev->chunkShift){
            /* Easy-peasy power of 2 case */
            *chunk  = (__u32)(addr >> dev->chunkShift);
            *offset = (__u32)(addr & dev->chunkMask);
      }
      else if(dev->crumbsPerChunk)
      {
            /* Case where we're using "crumbs" */
            *offset = (__u32)(addr & dev->crumbMask);
            addr >>= dev->crumbShift;
            *chunk = ((__u32)addr)/dev->crumbsPerChunk;
            *offset += ((addr - (*chunk * dev->crumbsPerChunk)) << dev->crumbShift);
      }
      else
            YBUG();
}

/* Function to return the number of shifts for a power of 2 greater than or equal
 * to the given number
 * Note we don't try to cater for all possible numbers and this does not have to
 * be hellishly efficient.
 */

static __u32 ShiftsGE(__u32 x)
{
      int extraBits;
      int nShifts;

      nShifts = extraBits = 0;

      while(x>1){
            if(x & 1) extraBits++;
            x>>=1;
            nShifts++;
      }

      if(extraBits)
            nShifts++;

      return nShifts;
}

/* Function to return the number of shifts to get a 1 in bit 0
 */

static __u32 ShiftDiv(__u32 x)
{
      int nShifts;

      nShifts =  0;

      if(!x) return 0;

      while( !(x&1)){
            x>>=1;
            nShifts++;
      }

      return nShifts;
}



/*
 * 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;
      for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
            if (dev->tempBuffer[i].line == 0) {
                  dev->tempBuffer[i].line = lineNo;
                  if ((i + 1) > dev->maxTemp) {
                        dev->maxTemp = i + 1;
                        for (j = 0; j <= i; j++)
                              dev->tempBuffer[j].maxLine =
                                  dev->tempBuffer[j].line;
                  }

                  return dev->tempBuffer[i].buffer;
            }
      }

      T(YAFFS_TRACE_BUFFERS,
        (TSTR("Out of temp buffers at line %d, other held by lines:"),
         lineNo));
      for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
            T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
      }
      T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));

      /*
       * If we got here then we have to allocate an unmanaged one
       * This is not good.
       */

      dev->unmanagedTempAllocations++;
      return YMALLOC(dev->nDataBytesPerChunk);

}

static void yaffs_ReleaseTempBuffer(yaffs_Device * dev, __u8 * buffer,
                            int lineNo)
{
      int i;
      for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
            if (dev->tempBuffer[i].buffer == buffer) {
                  dev->tempBuffer[i].line = 0;
                  return;
            }
      }

      if (buffer) {
            /* assume it is an unmanaged one. */
            T(YAFFS_TRACE_BUFFERS,
              (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
               lineNo));
            YFREE(buffer);
            dev->unmanagedTempDeallocations++;
      }

}

/*
 * Determine if we have a managed buffer.
 */
int yaffs_IsManagedTempBuffer(yaffs_Device * dev, const __u8 * buffer)
{
      int i;
      for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
            if (dev->tempBuffer[i].buffer == buffer)
                  return 1;

      }

    for (i = 0; i < dev->nShortOpCaches; i++) {
      if( dev->srCache[i].data == buffer )
          return 1;

    }

    if (buffer == dev->checkpointBuffer)
      return 1;

    T(YAFFS_TRACE_ALWAYS,
        (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
    return 0;
}



/*
 * Chunk bitmap manipulations
 */

static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device * dev, int blk)
{
      if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
            T(YAFFS_TRACE_ERROR,
              (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
               blk));
            YBUG();
      }
      return dev->chunkBits +
          (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);

      memset(blkBits, 0, dev->chunkBitmapStride);
}

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));
}

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;
}

static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device * dev, int blk)
{
      __u8 *blkBits = yaffs_BlockBits(dev, blk);
      int i;
      for (i = 0; i < dev->chunkBitmapStride; i++) {
            if (*blkBits)
                  return 1;
            blkBits++;
      }
      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;

      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;
      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
 */

static Y_INLINE int yaffs_HashFunction(int n)
{
/* XXX U-BOOT XXX */
      /*n = abs(n); */
      if (n < 0)
            n = -n;
      return (n % YAFFS_NOBJECT_BUCKETS);
}

/*
 * Access functions to useful fake objects
 */

yaffs_Object *yaffs_Root(yaffs_Device * dev)
{
      return dev->rootDir;
}

yaffs_Object *yaffs_LostNFound(yaffs_Device * dev)
{
      return dev->lostNFoundDir;
}


/*
 *  Erased NAND checking functions
 */

int yaffs_CheckFF(__u8 * buffer, int nBytes)
{
      /* Horrible, slow implementation */
      while (nBytes--) {
            if (*buffer != 0xFF)
                  return 0;
            buffer++;
      }
      return 1;
}

static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
                          int chunkInNAND)
{

      int retval = YAFFS_OK;
      __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
      yaffs_ExtendedTags tags;
      int result;

      result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);

      if(tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
            retval = YAFFS_FAIL;


      if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
            T(YAFFS_TRACE_NANDACCESS,
              (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
            retval = YAFFS_FAIL;
      }

      yaffs_ReleaseTempBuffer(dev, data, __LINE__);

      return retval;

}

static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
                                   const __u8 * data,
                                   yaffs_ExtendedTags * tags,
                                   int useReserve)
{
      int attempts = 0;
      int writeOk = 0;
      int chunk;

      yaffs_InvalidateCheckpoint(dev);

      do {
            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;
            }

            /* 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 != YAFFS_OK) {
                        T(YAFFS_TRACE_ERROR,
                        (TSTR ("**>> yaffs chunk %d was not erased"
                        TENDSTR), chunk));

                        /* try another chunk */
                        continue;
                  }
                  bi->skipErasedCheck = 1;
            }

            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));

            dev->nRetriedWrites += (attempts - 1);
      }

      return chunk;
}

/*
 * Block retiring for handling a broken block.
 */

static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND)
{
      yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);

      yaffs_InvalidateCheckpoint(dev);

      yaffs_MarkBlockBad(dev, blockInNAND);

      bi->blockState = YAFFS_BLOCK_STATE_DEAD;
      bi->gcPrioritise = 0;
      bi->needsRetiring = 0;

      dev->nRetiredBlocks++;
}

/*
 * Functions for robustisizing TODO
 *
 */

static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
                             const __u8 * data,
                             const yaffs_ExtendedTags * tags)
{
}

static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
                            const yaffs_ExtendedTags * tags)
{
}

void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
{
      if(!bi->gcPrioritise){
            bi->gcPrioritise = 1;
            dev->hasPendingPrioritisedGCs = 1;
            bi->chunkErrorStrikes ++;

            if(bi->chunkErrorStrikes > 3){
                  bi->needsRetiring = 1; /* Too many stikes, so retire this */
                  T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));

            }

      }
}

static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk)
{

      int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
      yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);

      yaffs_HandleChunkError(dev,bi);


      if(erasedOk ) {
            /* Was an actual write failure, so mark the block for retirement  */
            bi->needsRetiring = 1;
            T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
              (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));


      }

      /* Delete the chunk */
      yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
}


/*---------------- Name handling functions ------------*/

static __u16 yaffs_CalcNameSum(const YCHAR * name)
{
      __u16 sum = 0;
      __u16 i = 1;

      YUCHAR *bname = (YUCHAR *) name;
      if (bname) {
            while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {

#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
                  sum += yaffs_toupper(*bname) * i;
#else
                  sum += (*bname) * i;
#endif
                  i++;
                  bname++;
            }
      }
      return sum;
}

static void yaffs_SetObjectName(yaffs_Object * obj, const YCHAR * name)
{
#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
      if (name && yaffs_strlen(name) <= YAFFS_SHORT_NAME_LENGTH) {
            yaffs_strcpy(obj->shortName, name);
      } else {
            obj->shortName[0] = _Y('\0');
      }
#endif
      obj->sum = yaffs_CalcNameSum(name);
}

/*-------------------- TNODES -------------------

 * List of spare tnodes
 * The list is hooked together using the first pointer
 * in the tnode.
 */

/* yaffs_CreateTnodes creates a bunch more tnodes and
 * adds them to the tnode free list.
 * Don't use this function directly
 */

static int yaffs_CreateTnodes(yaffs_Device * dev, int nTnodes)
{
      int i;
      int tnodeSize;
      yaffs_Tnode *newTnodes;
      __u8 *mem;
      yaffs_Tnode *curr;
      yaffs_Tnode *next;
      yaffs_TnodeList *tnl;

      if (nTnodes < 1)
            return YAFFS_OK;

      /* Calculate the tnode size in bytes for variable width tnode support.
       * Must be a multiple of 32-bits  */
      tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;

      /* make these things */

      newTnodes = YMALLOC(nTnodes * tnodeSize);
      mem = (__u8 *)newTnodes;

      if (!newTnodes) {
            T(YAFFS_TRACE_ERROR,
              (TSTR("yaffs: Could not allocate Tnodes" TENDSTR)));
            return YAFFS_FAIL;
      }

      /* Hook them into the free list */
#if 0
      for (i = 0; i < nTnodes - 1; i++) {
            newTnodes[i].internal[0] = &newTnodes[i + 1];
#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
            newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
#endif
      }

      newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
      newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
#endif
      dev->freeTnodes = newTnodes;
#else
      /* New hookup for wide tnodes */
      for(i = 0; i < nTnodes -1; i++) {
            curr = (yaffs_Tnode *) &mem[i * tnodeSize];
            next = (yaffs_Tnode *) &mem[(i+1) * tnodeSize];
            curr->internal[0] = next;
      }

      curr = (yaffs_Tnode *) &mem[(nTnodes - 1) * tnodeSize];
      curr->internal[0] = dev->freeTnodes;
      dev->freeTnodes = (yaffs_Tnode *)mem;

#endif


      dev->nFreeTnodes += nTnodes;
      dev->nTnodesCreated += nTnodes;

      /* Now add this bunch of tnodes to a list for freeing up.
       * NB If we can't add this to the management list it isn't fatal
       * but it just means we can't free this bunch of tnodes later.
       */

      tnl = YMALLOC(sizeof(yaffs_TnodeList));
      if (!tnl) {
            T(YAFFS_TRACE_ERROR,
              (TSTR
               ("yaffs: Could not add tnodes to management list" TENDSTR)));
               return YAFFS_FAIL;

      } else {
            tnl->tnodes = newTnodes;
            tnl->next = dev->allocatedTnodeList;
            dev->allocatedTnodeList = tnl;
      }

      T(YAFFS_TRACE_ALLOCATE, (TSTR("yaffs: Tnodes added" TENDSTR)));

      return YAFFS_OK;
}

/* GetTnode gets us a clean tnode. Tries to make allocate more if we run out */

static yaffs_Tnode *yaffs_GetTnodeRaw(yaffs_Device * dev)
{
      yaffs_Tnode *tn = NULL;

      /* If there are none left make more */
      if (!dev->freeTnodes) {
            yaffs_CreateTnodes(dev, YAFFS_ALLOCATION_NTNODES);
      }

      if (dev->freeTnodes) {
            tn = dev->freeTnodes;
#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
            if (tn->internal[YAFFS_NTNODES_INTERNAL] != (void *)1) {
                  /* Hoosterman, this thing looks like it isn't in the list */
                  T(YAFFS_TRACE_ALWAYS,
                    (TSTR("yaffs: Tnode list bug 1" TENDSTR)));
            }
#endif
            dev->freeTnodes = dev->freeTnodes->internal[0];
            dev->nFreeTnodes--;
      }

      return tn;
}

static yaffs_Tnode *yaffs_GetTnode(yaffs_Device * dev)
{
      yaffs_Tnode *tn = yaffs_GetTnodeRaw(dev);

      if(tn)
            memset(tn, 0, (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);

      return tn;
}

/* FreeTnode frees up a tnode and puts it back on the free list */
static void yaffs_FreeTnode(yaffs_Device * dev, yaffs_Tnode * tn)
{
      if (tn) {
#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
            if (tn->internal[YAFFS_NTNODES_INTERNAL] != 0) {
                  /* Hoosterman, this thing looks like it is already in the list */
                  T(YAFFS_TRACE_ALWAYS,
                    (TSTR("yaffs: Tnode list bug 2" TENDSTR)));
            }
            tn->internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
#endif
            tn->internal[0] = dev->freeTnodes;
            dev->freeTnodes = tn;
            dev->nFreeTnodes++;
      }
}

static void yaffs_DeinitialiseTnodes(yaffs_Device * dev)
{
      /* Free the list of allocated tnodes */
      yaffs_TnodeList *tmp;

      while (dev->allocatedTnodeList) {
            tmp = dev->allocatedTnodeList->next;

            YFREE(dev->allocatedTnodeList->tnodes);
            YFREE(dev->allocatedTnodeList);
            dev->allocatedTnodeList = tmp;

      }

      dev->freeTnodes = NULL;
      dev->nFreeTnodes = 0;
}

static void yaffs_InitialiseTnodes(yaffs_Device * dev)
{
      dev->allocatedTnodeList = NULL;
      dev->freeTnodes = NULL;
      dev->nFreeTnodes = 0;
      dev->nTnodesCreated = 0;

}


void yaffs_PutLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos, unsigned val)
{
  __u32 *map = (__u32 *)tn;
  __u32 bitInMap;
  __u32 bitInWord;
  __u32 wordInMap;
  __u32 mask;

  pos &= YAFFS_TNODES_LEVEL0_MASK;
  val >>= dev->chunkGroupBits;

  bitInMap = pos * dev->tnodeWidth;
  wordInMap = bitInMap /32;
  bitInWord = bitInMap & (32 -1);

  mask = dev->tnodeMask << bitInWord;

  map[wordInMap] &= ~mask;
  map[wordInMap] |= (mask & (val << bitInWord));

  if(dev->tnodeWidth > (32-bitInWord)) {
    bitInWord = (32 - bitInWord);
    wordInMap++;;
    mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
    map[wordInMap] &= ~mask;
    map[wordInMap] |= (mask & (val >> bitInWord));
  }
}

static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos)
{
  __u32 *map = (__u32 *)tn;
  __u32 bitInMap;
  __u32 bitInWord;
  __u32 wordInMap;
  __u32 val;

  pos &= YAFFS_TNODES_LEVEL0_MASK;

  bitInMap = pos * dev->tnodeWidth;
  wordInMap = bitInMap /32;
  bitInWord = bitInMap & (32 -1);

  val = map[wordInMap] >> bitInWord;

  if(dev->tnodeWidth > (32-bitInWord)) {
    bitInWord = (32 - bitInWord);
    wordInMap++;;
    val |= (map[wordInMap] << bitInWord);
  }

  val &= dev->tnodeMask;
  val <<= dev->chunkGroupBits;

  return val;
}

/* ------------------- End of individual tnode manipulation -----------------*/

/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 * The look up tree is represented by the top tnode and the number of topLevel
 * in the tree. 0 means only the level 0 tnode is in the tree.
 */

/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
                                yaffs_FileStructure * fStruct,
                                __u32 chunkId)
{

      yaffs_Tnode *tn = fStruct->top;
      __u32 i;
      int requiredTallness;
      int level = fStruct->topLevel;

      /* Check sane level and chunk Id */
      if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL) {
            return NULL;
      }

      if (chunkId > YAFFS_MAX_CHUNK_ID) {
            return NULL;
      }

      /* First check we're tall enough (ie enough topLevel) */

      i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
      requiredTallness = 0;
      while (i) {
            i >>= YAFFS_TNODES_INTERNAL_BITS;
            requiredTallness++;
      }

      if (requiredTallness > fStruct->topLevel) {
            /* Not tall enough, so we can't find it, return NULL. */
            return NULL;
      }

      /* Traverse down to level 0 */
      while (level > 0 && tn) {
            tn = tn->
                internal[(chunkId >>
                         ( YAFFS_TNODES_LEVEL0_BITS +
                         (level - 1) *
                         YAFFS_TNODES_INTERNAL_BITS)
                        ) &
                       YAFFS_TNODES_INTERNAL_MASK];
            level--;

      }

      return tn;
}

/* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
 * This happens in two steps:
 *  1. If the tree isn't tall enough, then make it taller.
 *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 *
 * Used when modifying the tree.
 *
 *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
 *  be plugged into the ttree.
 */

static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device * dev,
                                     yaffs_FileStructure * fStruct,
                                     __u32 chunkId,
                                     yaffs_Tnode *passedTn)
{

      int requiredTallness;
      int i;
      int l;
      yaffs_Tnode *tn;

      __u32 x;


      /* Check sane level and page Id */
      if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL) {
            return NULL;
      }

      if (chunkId > YAFFS_MAX_CHUNK_ID) {
            return NULL;
      }

      /* First check we're tall enough (ie enough topLevel) */

      x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
      requiredTallness = 0;
      while (x) {
            x >>= YAFFS_TNODES_INTERNAL_BITS;
            requiredTallness++;
      }


      if (requiredTallness > fStruct->topLevel) {
            /* Not tall enough,gotta make the tree taller */
            for (i = fStruct->topLevel; i < requiredTallness; i++) {

                  tn = yaffs_GetTnode(dev);

                  if (tn) {
                        tn->internal[0] = fStruct->top;
                        fStruct->top = tn;
                  } else {
                        T(YAFFS_TRACE_ERROR,
                          (TSTR("yaffs: no more tnodes" TENDSTR)));
                  }
            }

            fStruct->topLevel = requiredTallness;
      }

      /* Traverse down to level 0, adding anything we need */

      l = fStruct->topLevel;
      tn = fStruct->top;

      if(l > 0) {
            while (l > 0 && tn) {
                  x = (chunkId >>
                       ( YAFFS_TNODES_LEVEL0_BITS +
                        (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
                      YAFFS_TNODES_INTERNAL_MASK;


                  if((l>1) && !tn->internal[x]){
                        /* Add missing non-level-zero tnode */
                        tn->internal[x] = yaffs_GetTnode(dev);

                  } else if(l == 1) {
                        /* Looking from level 1 at level 0 */
                        if (passedTn) {
                              /* If we already have one, then release it.*/
                              if(tn->internal[x])
                                    yaffs_FreeTnode(dev,tn->internal[x]);
                              tn->internal[x] = passedTn;

                        } else if(!tn->internal[x]) {
                              /* Don't have one, none passed in */
                              tn->internal[x] = yaffs_GetTnode(dev);
                        }
                  }

                  tn = tn->internal[x];
                  l--;
            }
      } else {
            /* top is level 0 */
            if(passedTn) {
                  memcpy(tn,passedTn,(dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
                  yaffs_FreeTnode(dev,passedTn);
            }
      }

      return tn;
}

static int yaffs_FindChunkInGroup(yaffs_Device * dev, int theChunk,
                          yaffs_ExtendedTags * tags, int objectId,
                          int chunkInInode)
{
      int j;

      for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
            if (yaffs_CheckChunkBit
                (dev, theChunk / dev->nChunksPerBlock,
                 theChunk % dev->nChunksPerBlock)) {
                  yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
                                          tags);
                  if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
                        /* found it; */
                        return theChunk;

                  }
            }
            theChunk++;
      }
      return -1;
}


/* DeleteWorker scans backwards through the tnode tree and deletes all the
 * chunks and tnodes in the file
 * Returns 1 if the tree was deleted.
 * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
 */

static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
                        int chunkOffset, int *limit)
{
      int i;
      int chunkInInode;
      int theChunk;
      yaffs_ExtendedTags tags;
      int foundChunk;
      yaffs_Device *dev = in->myDev;

      int allDone = 1;

      if (tn) {
            if (level > 0) {

                  for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
                       i--) {
                        if (tn->internal[i]) {
                              if (limit && (*limit) < 0) {
                                    allDone = 0;
                              } else {
                                    allDone =
                                        yaffs_DeleteWorker(in,
                                                       tn->
                                                       internal
                                                       [i],
                                                       level -
                                                       1,
                                                       (chunkOffset
                                                      <<
                                                      YAFFS_TNODES_INTERNAL_BITS)
                                                       + i,
                                                       limit);
                              }
                              if (allDone) {
                                    yaffs_FreeTnode(dev,
                                                tn->
                                                internal[i]);
                                    tn->internal[i] = NULL;
                              }
                        }

                  }
                  return (allDone) ? 1 : 0;
            } else if (level == 0) {
                  int hitLimit = 0;

                  for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
                       i--) {
                        theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
                        if (theChunk) {

                              chunkInInode =
                                  (chunkOffset <<
                                   YAFFS_TNODES_LEVEL0_BITS) + i;

                              foundChunk =
                                  yaffs_FindChunkInGroup(dev,
                                                   theChunk,
                                                   &tags,
                                                   in->objectId,
                                                   chunkInInode);

                              if (foundChunk > 0) {
                                    yaffs_DeleteChunk(dev,
                                                  foundChunk, 1,
                                                  __LINE__);
                                    in->nDataChunks--;
                                    if (limit) {
                                          *limit = *limit - 1;
                                          if (*limit <= 0) {
                                                hitLimit = 1;
                                          }
                                    }

                              }

                              yaffs_PutLevel0Tnode(dev,tn,i,0);
                        }

                  }
                  return (i < 0) ? 1 : 0;

            }

      }

      return 1;

}

static void yaffs_SoftDeleteChunk(yaffs_Device * dev, int chunk)
{

      yaffs_BlockInfo *theBlock;

      T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));

      theBlock = yaffs_GetBlockInfo(dev, chunk / dev->nChunksPerBlock);
      if (theBlock) {
            theBlock->softDeletions++;
            dev->nFreeChunks++;
      }
}

/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
 * All soft deleting does is increment the block's softdelete count and pulls the chunk out
 * of the tnode.
 * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
 */

static int yaffs_SoftDeleteWorker(yaffs_Object * in, yaffs_Tnode * tn,
                          __u32 level, int chunkOffset)
{
      int i;
      int theChunk;
      int allDone = 1;
      yaffs_Device *dev = in->myDev;

      if (tn) {
            if (level > 0) {

                  for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
                       i--) {
                        if (tn->internal[i]) {
                              allDone =
                                  yaffs_SoftDeleteWorker(in,
                                                   tn->
                                                   internal[i],
                                                   level - 1,
                                                   (chunkOffset
                                                    <<
                                                    YAFFS_TNODES_INTERNAL_BITS)
                                                   + i);
                              if (allDone) {
                                    yaffs_FreeTnode(dev,
                                                tn->
                                                internal[i]);
                                    tn->internal[i] = NULL;
                              } else {
                                    /* Hoosterman... how could this happen? */
                              }
                        }
                  }
                  return (allDone) ? 1 : 0;
            } else if (level == 0) {

                  for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
                        theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
                        if (theChunk) {
                              /* Note this does not find the real chunk, only the chunk group.
                               * We make an assumption that a chunk group is not larger than
                               * a block.
                               */
                              yaffs_SoftDeleteChunk(dev, theChunk);
                              yaffs_PutLevel0Tnode(dev,tn,i,0);
                        }

                  }
                  return 1;

            }

      }

      return 1;

}

static void yaffs_SoftDeleteFile(yaffs_Object * obj)
{
      if (obj->deleted &&
          obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
            if (obj->nDataChunks <= 0) {
                  /* Empty file with no duplicate object headers, just delete it immediately */
                  yaffs_FreeTnode(obj->myDev,
                              obj->variant.fileVariant.top);
                  obj->variant.fileVariant.top = NULL;
                  T(YAFFS_TRACE_TRACING,
                    (TSTR("yaffs: Deleting empty file %d" TENDSTR),
                     obj->objectId));
                  yaffs_DoGenericObjectDeletion(obj);
            } else {
                  yaffs_SoftDeleteWorker(obj,
                                     obj->variant.fileVariant.top,
                                     obj->variant.fileVariant.
                                     topLevel, 0);
                  obj->softDeleted = 1;
            }
      }
}

/* Pruning removes any part of the file structure tree that is beyond the
 * bounds of the file (ie that does not point to chunks).
 *
 * A file should only get pruned when its size is reduced.
 *
 * Before pruning, the chunks must be pulled from the tree and the
 * level 0 tnode entries must be zeroed out.
 * Could also use this for file deletion, but that's probably better handled
 * by a special case.
 */

static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device * dev, yaffs_Tnode * tn,
                              __u32 level, int del0)
{
      int i;
      int hasData;

      if (tn) {
            hasData = 0;

            for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
                  if (tn->internal[i] && level > 0) {
                        tn->internal[i] =
                            yaffs_PruneWorker(dev, tn->internal[i],
                                          level - 1,
                                          (i == 0) ? del0 : 1);
                  }

                  if (tn->internal[i]) {
                        hasData++;
                  }
            }

            if (hasData == 0 && del0) {
                  /* Free and return NULL */

                  yaffs_FreeTnode(dev, tn);
                  tn = NULL;
            }

      }

      return tn;

}

static int yaffs_PruneFileStructure(yaffs_Device * dev,
                            yaffs_FileStructure * fStruct)
{
      int i;
      int hasData;
      int done = 0;
      yaffs_Tnode *tn;

      if (fStruct->topLevel > 0) {
            fStruct->top =
                yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);

            /* Now we have a tree with all the non-zero branches NULL but the height
             * is the same as it was.
             * Let's see if we can trim internal tnodes to shorten the tree.
             * We can do this if only the 0th element in the tnode is in use
             * (ie all the non-zero are NULL)
             */

            while (fStruct->topLevel && !done) {
                  tn = fStruct->top;

                  hasData = 0;
                  for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
                        if (tn->internal[i]) {
                              hasData++;
                        }
                  }

                  if (!hasData) {
                        fStruct->top = tn->internal[0];
                        fStruct->topLevel--;
                        yaffs_FreeTnode(dev, tn);
                  } else {
                        done = 1;
                  }
            }
      }

      return YAFFS_OK;
}

/*-------------------- End of File Structure functions.-------------------*/

/* yaffs_CreateFreeObjects creates a bunch more objects and
 * adds them to the object free list.
 */
static int yaffs_CreateFreeObjects(yaffs_Device * dev, int nObjects)
{
      int i;
      yaffs_Object *newObjects;
      yaffs_ObjectList *list;

      if (nObjects < 1)
            return YAFFS_OK;

      /* make these things */
      newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
      list = YMALLOC(sizeof(yaffs_ObjectList));

      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;
      }

      /* Hook them into the free list */
      for (i = 0; i < nObjects - 1; i++) {
            newObjects[i].siblings.next =
                (struct list_head *)(&newObjects[i + 1]);
      }

      newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
      dev->freeObjects = newObjects;
      dev->nFreeObjects += nObjects;
      dev->nObjectsCreated += nObjects;

      /* Now add this bunch of Objects to a list for freeing up. */

      list->objects = newObjects;
      list->next = dev->allocatedObjectList;
      dev->allocatedObjectList = list;

      return YAFFS_OK;
}


/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device * dev)
{
      yaffs_Object *tn = NULL;

      /* If there are none left make more */
      if (!dev->freeObjects) {
            yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
      }

      if (dev->freeObjects) {
            tn = dev->freeObjects;
            dev->freeObjects =
                (yaffs_Object *) (dev->freeObjects->siblings.next);
            dev->nFreeObjects--;

            /* Now sweeten it up... */

            memset(tn, 0, sizeof(yaffs_Object));
            tn->myDev = dev;
            tn->chunkId = -1;
            tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
            INIT_LIST_HEAD(&(tn->hardLinks));
            INIT_LIST_HEAD(&(tn->hashLink));
            INIT_LIST_HEAD(&tn->siblings);

            /* Add it to the lost and found directory.
             * NB Can't put root or lostNFound in lostNFound so
             * check if lostNFound exists first
             */
            if (dev->lostNFoundDir) {
                  yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
            }
      }

      return tn;
}

static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device * dev, int number,
                                     __u32 mode)
{

      yaffs_Object *obj =
          yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
      if (obj) {
            obj->fake = 1;          /* it is fake so it has no NAND presence... */
            obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
            obj->unlinkAllowed = 0; /* ... or unlink it */
            obj->deleted = 0;
            obj->unlinked = 0;
            obj->yst_mode = mode;
            obj->myDev = dev;
            obj->chunkId = 0; /* Not a valid chunk. */
      }

      return obj;

}

static void yaffs_UnhashObject(yaffs_Object * tn)
{
      int bucket;
      yaffs_Device *dev = tn->myDev;

      /* If it is still linked into the bucket list, free from the list */
      if (!list_empty(&tn->hashLink)) {
            list_del_init(&tn->hashLink);
            bucket = yaffs_HashFunction(tn->objectId);
            dev->objectBucket[bucket].count--;
      }

}

/*  FreeObject frees up a Object and puts it back on the free list */
static void yaffs_FreeObject(yaffs_Object * tn)
{

      yaffs_Device *dev = tn->myDev;

/* XXX U-BOOT XXX */
#if 0
#ifdef  __KERNEL__
      if (tn->myInode) {
            /* We're still hooked up to a cached inode.
             * Don't delete now, but mark for later deletion
             */
            tn->deferedFree = 1;
            return;
      }
#endif
#endif
      yaffs_UnhashObject(tn);

      /* Link into the free list. */
      tn->siblings.next = (struct list_head *)(dev->freeObjects);
      dev->freeObjects = tn;
      dev->nFreeObjects++;
}

/* XXX U-BOOT XXX */
#if 0
#ifdef __KERNEL__

void yaffs_HandleDeferedFree(yaffs_Object * obj)
{
      if (obj->deferedFree) {
            yaffs_FreeObject(obj);
      }
}

#endif
#endif

static void yaffs_DeinitialiseObjects(yaffs_Device * dev)
{
      /* Free the list of allocated Objects */

      yaffs_ObjectList *tmp;

      while (dev->allocatedObjectList) {
            tmp = dev->allocatedObjectList->next;
            YFREE(dev->allocatedObjectList->objects);
            YFREE(dev->allocatedObjectList);

            dev->allocatedObjectList = tmp;
      }

      dev->freeObjects = NULL;
      dev->nFreeObjects = 0;
}

static void yaffs_InitialiseObjects(yaffs_Device * dev)
{
      int i;

      dev->allocatedObjectList = NULL;
      dev->freeObjects = NULL;
      dev->nFreeObjects = 0;

      for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
            INIT_LIST_HEAD(&dev->objectBucket[i].list);
            dev->objectBucket[i].count = 0;
      }

}

static int yaffs_FindNiceObjectBucket(yaffs_Device * dev)
{
      static int x = 0;
      int i;
      int l = 999;
      int lowest = 999999;

      /* First let's see if we can find one that's empty. */

      for (i = 0; i < 10 && lowest > 0; i++) {
            x++;
            x %= YAFFS_NOBJECT_BUCKETS;
            if (dev->objectBucket[x].count < lowest) {
                  lowest = dev->objectBucket[x].count;
                  l = x;
            }

      }

      /* If we didn't find an empty list, then try
       * looking a bit further for a short one
       */

      for (i = 0; i < 10 && lowest > 3; i++) {
            x++;
            x %= YAFFS_NOBJECT_BUCKETS;
            if (dev->objectBucket[x].count < lowest) {
                  lowest = dev->objectBucket[x].count;
                  l = x;
            }

      }

      return l;
}

static int yaffs_CreateNewObjectNumber(yaffs_Device * dev)
{
      int bucket = yaffs_FindNiceObjectBucket(dev);

      /* Now find an object value that has not already been taken
       * by scanning the list.
       */

      int found = 0;
      struct list_head *i;

      __u32 n = (__u32) bucket;

      /* yaffs_CheckObjectHashSanity();  */

      while (!found) {
            found = 1;
            n += YAFFS_NOBJECT_BUCKETS;
            if (1 || dev->objectBucket[bucket].count > 0) {
                  list_for_each(i, &dev->objectBucket[bucket].list) {
                        /* If there is already one in the list */
                        if (i
                            && list_entry(i, yaffs_Object,
                                      hashLink)->objectId == n) {
                              found = 0;
                        }
                  }
            }
      }


      return n;
}

static void yaffs_HashObject(yaffs_Object * in)
{
      int bucket = yaffs_HashFunction(in->objectId);
      yaffs_Device *dev = in->myDev;

      list_add(&in->hashLink, &dev->objectBucket[bucket].list);
      dev->objectBucket[bucket].count++;

}

yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device * dev, __u32 number)
{
      int bucket = yaffs_HashFunction(number);
      struct list_head *i;
      yaffs_Object *in;

      list_for_each(i, &dev->objectBucket[bucket].list) {
            /* Look if it is in the list */
            if (i) {
                  in = list_entry(i, yaffs_Object, hashLink);
                  if (in->objectId == number) {
/* XXX U-BOOT XXX */
#if 0
#ifdef __KERNEL__
                        /* Don't tell the VFS about this one if it is defered free */
                        if (in->deferedFree)
                              return NULL;
#endif
#endif
                        return in;
                  }
            }
      }

      return NULL;
}

yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
                            yaffs_ObjectType type)
{

      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;
            theObject->renameAllowed = 1;
            theObject->unlinkAllowed = 1;
            theObject->objectId = number;
            yaffs_HashObject(theObject);
            theObject->variantType = type;
#ifdef CONFIG_YAFFS_WINCE
            yfsd_WinFileTimeNow(theObject->win_atime);
            theObject->win_ctime[0] = theObject->win_mtime[0] =
                theObject->win_atime[0];
            theObject->win_ctime[1] = theObject->win_mtime[1] =
                theObject->win_atime[1];

#else

            theObject->yst_atime = theObject->yst_mtime =
                theObject->yst_ctime = Y_CURRENT_TIME;
#endif
            switch (type) {
            case YAFFS_OBJECT_TYPE_FILE:
                  theObject->variant.fileVariant.fileSize = 0;
                  theObject->variant.fileVariant.scannedFileSize = 0;
                  theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF;     /* max __u32 */
                  theObject->variant.fileVariant.topLevel = 0;
                  theObject->variant.fileVariant.top = tn;
                  break;
            case YAFFS_OBJECT_TYPE_DIRECTORY:
                  INIT_LIST_HEAD(&theObject->variant.directoryVariant.
                               children);
                  break;
            case YAFFS_OBJECT_TYPE_SYMLINK:
            case YAFFS_OBJECT_TYPE_HARDLINK:
            case YAFFS_OBJECT_TYPE_SPECIAL:
                  /* No action required */
                  break;
            case YAFFS_OBJECT_TYPE_UNKNOWN:
                  /* todo this should not happen */
                  break;
            }
      }

      return theObject;
}

static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device * dev,
                                          int number,
                                          yaffs_ObjectType type)
{
      yaffs_Object *theObject = NULL;

      if (number > 0) {
            theObject = yaffs_FindObjectByNumber(dev, number);
      }

      if (!theObject) {
            theObject = yaffs_CreateNewObject(dev, number, type);
      }

      return theObject;

}


static YCHAR *yaffs_CloneString(const YCHAR * str)
{
      YCHAR *newStr = NULL;

      if (str && *str) {
            newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
            if(newStr)
                  yaffs_strcpy(newStr, str);
      }

      return newStr;

}

/*
 * Mknod (create) a new object.
 * equivalentObject only has meaning for a hard link;
 * aliasString only has meaning for a sumlink.
 * rdev only has meaning for devices (a subset of special objects)
 */

static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
                               yaffs_Object * parent,
                               const YCHAR * name,
                               __u32 mode,
                               __u32 uid,
                               __u32 gid,
                               yaffs_Object * equivalentObject,
                               const YCHAR * aliasString, __u32 rdev)
{
      yaffs_Object *in;
      YCHAR *str;

      yaffs_Device *dev = parent->myDev;

      /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
      if (yaffs_FindObjectByName(parent, name)) {
            return NULL;
      }

      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;
            in->valid = 1;
            in->variantType = type;

            in->yst_mode = mode;

#ifdef CONFIG_YAFFS_WINCE
            yfsd_WinFileTimeNow(in->win_atime);
            in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
            in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];

#else
            in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;

            in->yst_rdev = rdev;
            in->yst_uid = uid;
            in->yst_gid = gid;
#endif
            in->nDataChunks = 0;

            yaffs_SetObjectName(in, name);
            in->dirty = 1;

            yaffs_AddObjectToDirectory(parent, in);

            in->myDev = parent->myDev;

            switch (type) {
            case YAFFS_OBJECT_TYPE_SYMLINK:
                  in->variant.symLinkVariant.alias = str;
                  break;
            case YAFFS_OBJECT_TYPE_HARDLINK:
                  in->variant.hardLinkVariant.equivalentObject =
                      equivalentObject;
                  in->variant.hardLinkVariant.equivalentObjectId =
                      equivalentObject->objectId;
                  list_add(&in->hardLinks, &equivalentObject->hardLinks);
                  break;
            case YAFFS_OBJECT_TYPE_FILE:
            case YAFFS_OBJECT_TYPE_DIRECTORY:
            case YAFFS_OBJECT_TYPE_SPECIAL:
            case YAFFS_OBJECT_TYPE_UNKNOWN:
                  /* do nothing */
                  break;
            }

            if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
                  /* Could not create the object header, fail the creation */
                  yaffs_DestroyObject(in);
                  in = NULL;
            }

      }

      return in;
}

yaffs_Object *yaffs_MknodFile(yaffs_Object * parent, const YCHAR * name,
                        __u32 mode, __u32 uid, __u32 gid)
{
      return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
                         uid, gid, NULL, NULL, 0);
}

yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
                           __u32 mode, __u32 uid, __u32 gid)
{
      return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
                         mode, uid, gid, NULL, NULL, 0);
}

yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
                         __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
{
      return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
                         uid, gid, NULL, NULL, rdev);
}

yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
                         __u32 mode, __u32 uid, __u32 gid,
                         const YCHAR * alias)
{
      return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
                         uid, gid, NULL, alias, 0);
}

/* yaffs_Link returns the object id of the equivalent object.*/
yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
                   yaffs_Object * equivalentObject)
{
      /* Get the real object in case we were fed a hard link as an equivalent object */
      equivalentObject = yaffs_GetEquivalentObject(equivalentObject);

      if (yaffs_MknodObject
          (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
           equivalentObject, NULL, 0)) {
            return equivalentObject;
      } else {
            return NULL;
      }

}

static int yaffs_ChangeObjectName(yaffs_Object * obj, yaffs_Object * newDir,
                          const YCHAR * newName, int force, int shadows)
{
      int unlinkOp;
      int deleteOp;

      yaffs_Object *existingTarget;

      if (newDir == NULL) {
            newDir = obj->parent;   /* use the old directory */
      }

      if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragendy: yaffs_ChangeObjectName: newDir is not a directory"
                TENDSTR)));
            YBUG();
      }

      /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
      if (obj->myDev->isYaffs2) {
            unlinkOp = (newDir == obj->myDev->unlinkedDir);
      } else {
            unlinkOp = (newDir == obj->myDev->unlinkedDir
                      && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
      }

      deleteOp = (newDir == obj->myDev->deletedDir);

      existingTarget = yaffs_FindObjectByName(newDir, newName);

      /* If the object is a file going into the unlinked directory,
       *   then it is OK to just stuff it in since duplicate names are allowed.
       *   else only proceed if the new name does not exist and if we're putting
       *   it into a directory.
       */
      if ((unlinkOp ||
           deleteOp ||
           force ||
           (shadows > 0) ||
           !existingTarget) &&
          newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
            yaffs_SetObjectName(obj, newName);
            obj->dirty = 1;

            yaffs_AddObjectToDirectory(newDir, obj);

            if (unlinkOp)
                  obj->unlinked = 1;

            /* If it is a deletion then we mark it as a shrink for gc purposes. */
            if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows)>= 0)
                  return YAFFS_OK;
      }

      return YAFFS_FAIL;
}

int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
                   yaffs_Object * newDir, const YCHAR * newName)
{
      yaffs_Object *obj;
      yaffs_Object *existingTarget;
      int force = 0;

#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
      /* Special case for case insemsitive systems (eg. WinCE).
       * While look-up is case insensitive, the name isn't.
       * Therefore we might want to change x.txt to X.txt
      */
      if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0) {
            force = 1;
      }
#endif

      obj = yaffs_FindObjectByName(oldDir, oldName);
      /* Check new name to long. */
      if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK &&
          yaffs_strlen(newName) > YAFFS_MAX_ALIAS_LENGTH)
        /* ENAMETOOLONG */
        return YAFFS_FAIL;
      else if (obj->variantType != YAFFS_OBJECT_TYPE_SYMLINK &&
             yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
        /* ENAMETOOLONG */
        return YAFFS_FAIL;

      if (obj && obj->renameAllowed) {

            /* Now do the handling for an existing target, if there is one */

            existingTarget = yaffs_FindObjectByName(newDir, newName);
            if (existingTarget &&
                existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
                !list_empty(&existingTarget->variant.directoryVariant.children)) {
                  /* There is a target that is a non-empty directory, so we fail */
                  return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
            } else if (existingTarget && existingTarget != obj) {
                  /* Nuke the target first, using shadowing,
                   * but only if it isn't the same object
                   */
                  yaffs_ChangeObjectName(obj, newDir, newName, force,
                                     existingTarget->objectId);
                  yaffs_UnlinkObject(existingTarget);
            }

            return yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
      }
      return YAFFS_FAIL;
}

/*------------------------- Block Management and Page Allocation ----------------*/

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 */

      /* 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));
            dev->blockInfoAlt = 1;
      }
      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;
            }
            else
                  dev->chunkBitsAlt = 0;
      }

      if (dev->blockInfo && dev->chunkBits) {
            memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
            memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
            return YAFFS_OK;
      }

      return YAFFS_FAIL;

}

static void yaffs_DeinitialiseBlocks(yaffs_Device * dev)
{
      if(dev->blockInfoAlt && dev->blockInfo)
            YFREE_ALT(dev->blockInfo);
      else if(dev->blockInfo)
            YFREE(dev->blockInfo);

      dev->blockInfoAlt = 0;

      dev->blockInfo = NULL;

      if(dev->chunkBitsAlt && dev->chunkBits)
            YFREE_ALT(dev->chunkBits);
      else if(dev->chunkBits)
            YFREE(dev->chunkBits);
      dev->chunkBitsAlt = 0;
      dev->chunkBits = NULL;
}

static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device * dev,
                                  yaffs_BlockInfo * bi)
{
      int i;
      __u32 seq;
      yaffs_BlockInfo *b;

      if (!dev->isYaffs2)
            return 1;   /* disqualification only applies to yaffs2. */

      if (!bi->hasShrinkHeader)
            return 1;   /* can gc */

      /* Find the oldest dirty sequence number if we don't know it and save it
       * so we don't have to keep recomputing it.
       */
      if (!dev->oldestDirtySequence) {
            seq = dev->sequenceNumber;

            for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
                 i++) {
                  b = yaffs_GetBlockInfo(dev, i);
                  if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
                      (b->pagesInUse - b->softDeletions) <
                      dev->nChunksPerBlock && b->sequenceNumber < seq) {
                        seq = b->sequenceNumber;
                  }
            }
            dev->oldestDirtySequence = seq;
      }

      /* Can't do gc of this block if there are any blocks older than this one that have
       * discarded pages.
       */
      return (bi->sequenceNumber <= dev->oldestDirtySequence);

}

/* FindDiretiestBlock is used to select the dirtiest block (or close enough)
 * for garbage collection.
 */

static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
                                     int aggressive)
{

      int b = dev->currentDirtyChecker;

      int i;
      int iterations;
      int dirtiest = -1;
      int pagesInUse = 0;
      int prioritised=0;
      yaffs_BlockInfo *bi;
      int pendingPrioritisedExist = 0;

      /* First let's see if we need to grab a prioritised block */
      if(dev->hasPendingPrioritisedGCs){
            for(i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++){

                  bi = yaffs_GetBlockInfo(dev, i);
                  //yaffs_VerifyBlock(dev,bi,i);

                  if(bi->gcPrioritise) {
                        pendingPrioritisedExist = 1;
                        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 */
                        }
                  }
            }

            if(!pendingPrioritisedExist) /* None found, so we can clear this */
                  dev->hasPendingPrioritisedGCs = 0;
      }

      /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
       * search harder.
       * else (we're doing a leasurely gc), then we only bother to do this if the
       * block has only a few pages in use.
       */

      dev->nonAggressiveSkip--;

      if (!aggressive && (dev->nonAggressiveSkip > 0)) {
            return -1;
      }

      if(!prioritised)
            pagesInUse =
                  (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;

      if (aggressive) {
            iterations =
                dev->internalEndBlock - dev->internalStartBlock + 1;
      } else {
            iterations =
                dev->internalEndBlock - dev->internalStartBlock + 1;
            iterations = iterations / 16;
            if (iterations > 200) {
                  iterations = 200;
            }
      }

      for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
            b++;
            if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
                  b = dev->internalStartBlock;
            }

            if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
                  T(YAFFS_TRACE_ERROR,
                    (TSTR("**>> Block %d is not valid" TENDSTR), b));
                  YBUG();
            }

            bi = yaffs_GetBlockInfo(dev, b);

#if 0
            if (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT) {
                  dirtiest = b;
                  pagesInUse = 0;
            }
            else
#endif

            if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
                   (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
                  yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
                  dirtiest = b;
                  pagesInUse = (bi->pagesInUse - bi->softDeletions);
            }
      }

      dev->currentDirtyChecker = b;

      if (dirtiest > 0) {
            T(YAFFS_TRACE_GC,
              (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
               dev->nChunksPerBlock - pagesInUse,prioritised));
      }

      dev->oldestDirtySequence = 0;

      if (dirtiest > 0) {
            dev->nonAggressiveSkip = 4;
      }

      return dirtiest;
}

static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
{
      yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);

      int erasedOk = 0;

      /* 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) {
            yaffs_InvalidateCheckpoint(dev);
            erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
            if (!erasedOk) {
                  dev->nErasureFailures++;
                  T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
                    (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
            }
      }

      if (erasedOk &&
          ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
            int i;
            for (i = 0; i < dev->nChunksPerBlock; i++) {
                  if (!yaffs_CheckChunkErased
                      (dev, blockNo * dev->nChunksPerBlock + i)) {
                        T(YAFFS_TRACE_ERROR,
                          (TSTR
                           (">>Block %d erasure supposedly OK, but chunk %d not erased"
                            TENDSTR), blockNo, i));
                  }
            }
      }

      if (erasedOk) {
            /* Clean it up... */
            bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
            dev->nErasedBlocks++;
            bi->pagesInUse = 0;
            bi->softDeletions = 0;
            bi->hasShrinkHeader = 0;
            bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
            bi->gcPrioritise = 0;
            yaffs_ClearChunkBits(dev, blockNo);

            T(YAFFS_TRACE_ERASE,
              (TSTR("Erased block %d" TENDSTR), blockNo));
      } else {
            dev->nFreeChunks -= dev->nChunksPerBlock; /* We lost a block of free space */

            yaffs_RetireBlock(dev, blockNo);
            T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
              (TSTR("**>> Block %d retired" TENDSTR), blockNo));
      }
}

static int yaffs_FindBlockForAllocation(yaffs_Device * dev)
{
      int i;

      yaffs_BlockInfo *bi;

      if (dev->nErasedBlocks < 1) {
            /* Hoosterman we've got a problem.
             * Can't get space to gc
             */
            T(YAFFS_TRACE_ERROR,
              (TSTR("yaffs tragedy: no more eraased blocks" TENDSTR)));

            return -1;
      }

      /* Find an empty block. */

      for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
            dev->allocationBlockFinder++;
            if (dev->allocationBlockFinder < dev->internalStartBlock
                || dev->allocationBlockFinder > dev->internalEndBlock) {
                  dev->allocationBlockFinder = dev->internalStartBlock;
            }

            bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);

            if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
                  bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
                  dev->sequenceNumber++;
                  bi->sequenceNumber = dev->sequenceNumber;
                  dev->nErasedBlocks--;
                  T(YAFFS_TRACE_ALLOCATE,
                    (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
                     dev->allocationBlockFinder, dev->sequenceNumber,
                     dev->nErasedBlocks));
                  return dev->allocationBlockFinder;
            }
      }

      T(YAFFS_TRACE_ALWAYS,
        (TSTR
         ("yaffs tragedy: no more eraased blocks, but there should have been %d"
          TENDSTR), dev->nErasedBlocks));

      return -1;
}


// Check if there's space to allocate...
// Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
static int yaffs_CheckSpaceForAllocation(yaffs_Device * dev)
{
      int reservedChunks;
      int reservedBlocks = dev->nReservedBlocks;
      int checkpointBlocks;

      checkpointBlocks =  dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint;
      if(checkpointBlocks < 0)
            checkpointBlocks = 0;

      reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);

      return (dev->nFreeChunks > reservedChunks);
}

static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr)
{
      int retVal;
      yaffs_BlockInfo *bi;

      if (dev->allocationBlock < 0) {
            /* Get next block to allocate off */
            dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
            dev->allocationPage = 0;
      }

      if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
            /* Not enough space to allocate unless we're allowed to use the reserve. */
            return -1;
      }

      if (dev->nErasedBlocks < dev->nReservedBlocks
          && dev->allocationPage == 0) {
            T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
      }

      /* Next page please.... */
      if (dev->allocationBlock >= 0) {
            bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);

            retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
                dev->allocationPage;
            bi->pagesInUse++;
            yaffs_SetChunkBit(dev, dev->allocationBlock,
                          dev->allocationPage);

            dev->allocationPage++;

            dev->nFreeChunks--;

            /* If the block is full set the state to full */
            if (dev->allocationPage >= dev->nChunksPerBlock) {
                  bi->blockState = YAFFS_BLOCK_STATE_FULL;
                  dev->allocationBlock = -1;
            }

            if(blockUsedPtr)
                  *blockUsedPtr = bi;

            return retVal;
      }

      T(YAFFS_TRACE_ERROR,
        (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));

      return -1;
}

static int yaffs_GetErasedChunks(yaffs_Device * dev)
{
      int n;

      n = dev->nErasedBlocks * dev->nChunksPerBlock;

      if (dev->allocationBlock > 0) {
            n += (dev->nChunksPerBlock - dev->allocationPage);
      }

      return n;

}

static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
{
      int oldChunk;
      int newChunk;
      int chunkInBlock;
      int markNAND;
      int retVal = YAFFS_OK;
      int cleanups = 0;
      int i;
      int isCheckpointBlock;
      int matchingChunk;

      int chunksBefore = yaffs_GetErasedChunks(dev);
      int chunksAfter;

      yaffs_ExtendedTags tags;

      yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);

      yaffs_Object *object;

      isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);

      bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;

      T(YAFFS_TRACE_TRACING,
        (TSTR("Collecting block %d, in use %d, shrink %d, " TENDSTR), block,
         bi->pagesInUse, bi->hasShrinkHeader));

      /*yaffs_VerifyFreeChunks(dev); */

      bi->hasShrinkHeader = 0;      /* clear the flag so that the block can erase */

      /* Take off the number of soft deleted entries because
       * they're going to get really deleted during GC.
       */
      dev->nFreeChunks -= bi->softDeletions;

      dev->isDoingGC = 1;

      if (isCheckpointBlock ||
          !yaffs_StillSomeChunkBits(dev, block)) {
            T(YAFFS_TRACE_TRACING,
              (TSTR
               ("Collecting block %d that has no chunks in use" TENDSTR),
               block));
            yaffs_BlockBecameDirty(dev, block);
      } else {

            __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);

            yaffs_VerifyBlock(dev,bi,block);

            for (chunkInBlock = 0, oldChunk = block * dev->nChunksPerBlock;
                 chunkInBlock < dev->nChunksPerBlock
                 && yaffs_StillSomeChunkBits(dev, block);
                 chunkInBlock++, oldChunk++) {
                  if (yaffs_CheckChunkBit(dev, block, chunkInBlock)) {

                        /* This page is in use and might need to be copied off */

                        markNAND = 1;

                        yaffs_InitialiseTags(&tags);

                        yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
                                                buffer, &tags);

                        object =
                            yaffs_FindObjectByNumber(dev,
                                               tags.objectId);

                        T(YAFFS_TRACE_GC_DETAIL,
                          (TSTR
                           ("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: %d %d %d "
                                  TENDSTR), oldChunk,
                                  tags.objectId, tags.chunkId, tags.byteCount));
                        }

                        if (object && object->deleted
                            && tags.chunkId != 0) {
                              /* Data chunk in a deleted file, throw it away
                               * It's a soft deleted data chunk,
                               * No need to copy this, just forget about it and
                               * fix up the object.
                               */

                              object->nDataChunks--;

                              if (object->nDataChunks <= 0) {
                                    /* remeber to clean up the object */
                                    dev->gcCleanupList[cleanups] =
                                        tags.objectId;
                                    cleanups++;
                              }
                              markNAND = 0;
                        } else if (0
                                 /* Todo object && object->deleted && object->nDataChunks == 0 */
                                 ) {
                              /* Deleted object header with no data chunks.
                               * Can be discarded and the file deleted.
                               */
                              object->chunkId = 0;
                              yaffs_FreeTnode(object->myDev,
                                          object->variant.
                                          fileVariant.top);
                              object->variant.fileVariant.top = NULL;
                              yaffs_DoGenericObjectDeletion(object);

                        } else if (object) {
                              /* It's either a data chunk in a live file or
                               * an ObjectHeader, so we're interested in it.
                               * NB Need to keep the ObjectHeaders of deleted files
                               * until the whole file has been deleted off
                               */
                              tags.serialNumber++;

                              dev->nGCCopies++;

                              if (tags.chunkId == 0) {
                                    /* It is an object Id,
                                     * We need to nuke the shrinkheader flags first
                                     * We no longer want the shrinkHeader flag since its work is done
                                     * and if it is left in place it will mess up scanning.
                                     * Also, clear out any shadowing stuff
                                     */

                                    yaffs_ObjectHeader *oh;
                                    oh = (yaffs_ObjectHeader *)buffer;
                                    oh->isShrink = 0;
                                    oh->shadowsObject = -1;
                                    tags.extraShadows = 0;
                                    tags.extraIsShrinkHeader = 0;

                                    yaffs_VerifyObjectHeader(object,oh,&tags,1);
                              }

                              newChunk =
                                  yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);

                              if (newChunk < 0) {
                                    retVal = YAFFS_FAIL;
                              } else {

                                    /* Ok, now fix up the Tnodes etc. */

                                    if (tags.chunkId == 0) {
                                          /* It's a header */
                                          object->chunkId =  newChunk;
                                          object->serial =   tags.serialNumber;
                                    } else {
                                          /* It's a data chunk */
                                          yaffs_PutChunkIntoFile
                                              (object,
                                               tags.chunkId,
                                               newChunk, 0);
                                    }
                              }
                        }

                        yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);

                  }
            }

            yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);


            /* Do any required cleanups */
            for (i = 0; i < cleanups; i++) {
                  /* Time to delete the file too */
                  object =
                      yaffs_FindObjectByNumber(dev,
                                         dev->gcCleanupList[i]);
                  if (object) {
                        yaffs_FreeTnode(dev,
                                    object->variant.fileVariant.
                                    top);
                        object->variant.fileVariant.top = NULL;
                        T(YAFFS_TRACE_GC,
                          (TSTR
                           ("yaffs: About to finally delete object %d"
                            TENDSTR), object->objectId));
                        yaffs_DoGenericObjectDeletion(object);
                        object->myDev->nDeletedFiles--;
                  }

            }

      }

      yaffs_VerifyCollectedBlock(dev,bi,block);

      if (chunksBefore >= (chunksAfter = yaffs_GetErasedChunks(dev))) {
            T(YAFFS_TRACE_GC,
              (TSTR
               ("gc did not increase free chunks before %d after %d"
                TENDSTR), chunksBefore, chunksAfter));
      }

      dev->isDoingGC = 0;

      return YAFFS_OK;
}

/* New garbage collector
 * If we're very low on erased blocks then we do aggressive garbage collection
 * otherwise we do "leasurely" garbage collection.
 * Aggressive gc looks further (whole array) and will accept less dirty blocks.
 * Passive gc only inspects smaller areas and will only accept more dirty blocks.
 *
 * The idea is to help clear out space in a more spread-out manner.
 * Dunno if it really does anything useful.
 */
static int yaffs_CheckGarbageCollection(yaffs_Device * dev)
{
      int block;
      int aggressive;
      int gcOk = YAFFS_OK;
      int maxTries = 0;

      int checkpointBlockAdjust;

      if (dev->isDoingGC) {
            /* Bail out so we don't get recursive gc */
            return YAFFS_OK;
      }

      /* This loop should pass the first time.
       * We'll only see looping here if the erase of the collected block fails.
       */

      do {
            maxTries++;

            checkpointBlockAdjust = (dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint);
            if(checkpointBlockAdjust < 0)
                  checkpointBlockAdjust = 0;

            if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
                  /* We need a block soon...*/
                  aggressive = 1;
            } else {
                  /* We're in no hurry */
                  aggressive = 0;
            }

            block = yaffs_FindBlockForGarbageCollection(dev, aggressive);

            if (block > 0) {
                  dev->garbageCollections++;
                  if (!aggressive) {
                        dev->passiveGarbageCollections++;
                  }

                  T(YAFFS_TRACE_GC,
                    (TSTR
                     ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
                     dev->nErasedBlocks, aggressive));

                  gcOk = yaffs_GarbageCollectBlock(dev, block);
            }

            if (dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) {
                  T(YAFFS_TRACE_GC,
                    (TSTR
                     ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
                      TENDSTR), dev->nErasedBlocks, maxTries, block));
            }
      } while ((dev->nErasedBlocks < dev->nReservedBlocks) && (block > 0)
             && (maxTries < 2));

      return aggressive ? gcOk : YAFFS_OK;
}

/*-------------------------  TAGS --------------------------------*/

static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
                     int chunkInObject)
{
      return (tags->chunkId == chunkInObject &&
            tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;

}


/*-------------------- Data file manipulation -----------------*/

static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
                         yaffs_ExtendedTags * tags)
{
      /*Get the Tnode, then get the level 0 offset chunk offset */
      yaffs_Tnode *tn;
      int theChunk = -1;
      yaffs_ExtendedTags localTags;
      int retVal = -1;

      yaffs_Device *dev = in->myDev;

      if (!tags) {
            /* Passed a NULL, so use our own tags space */
            tags = &localTags;
      }

      tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);

      if (tn) {
            theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);

            retVal =
                yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
                                 chunkInInode);
      }
      return retVal;
}

static int yaffs_FindAndDeleteChunkInFile(yaffs_Object * in, int chunkInInode,
                                yaffs_ExtendedTags * tags)
{
      /* Get the Tnode, then get the level 0 offset chunk offset */
      yaffs_Tnode *tn;
      int theChunk = -1;
      yaffs_ExtendedTags localTags;

      yaffs_Device *dev = in->myDev;
      int retVal = -1;

      if (!tags) {
            /* Passed a NULL, so use our own tags space */
            tags = &localTags;
      }

      tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);

      if (tn) {

            theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);

            retVal =
                yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
                                 chunkInInode);

            /* Delete the entry in the filestructure (if found) */
            if (retVal != -1) {
                  yaffs_PutLevel0Tnode(dev,tn,chunkInInode,0);
            }
      } else {
            /*T(("No level 0 found for %d\n", chunkInInode)); */
      }

      if (retVal == -1) {
            /* T(("Could not find %d to delete\n",chunkInInode)); */
      }
      return retVal;
}

#ifdef YAFFS_PARANOID

static int yaffs_CheckFileSanity(yaffs_Object * in)
{
      int chunk;
      int nChunks;
      int fSize;
      int failed = 0;
      int objId;
      yaffs_Tnode *tn;
      yaffs_Tags localTags;
      yaffs_Tags *tags = &localTags;
      int theChunk;
      int chunkDeleted;

      if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
            /* T(("Object not a file\n")); */
            return YAFFS_FAIL;
      }

      objId = in->objectId;
      fSize = in->variant.fileVariant.fileSize;
      nChunks =
          (fSize + in->myDev->nDataBytesPerChunk - 1) / in->myDev->nDataBytesPerChunk;

      for (chunk = 1; chunk <= nChunks; chunk++) {
            tn = yaffs_FindLevel0Tnode(in->myDev, &in->variant.fileVariant,
                                 chunk);

            if (tn) {

                  theChunk = yaffs_GetChunkGroupBase(dev,tn,chunk);

                  if (yaffs_CheckChunkBits
                      (dev, theChunk / dev->nChunksPerBlock,
                       theChunk % dev->nChunksPerBlock)) {

                        yaffs_ReadChunkTagsFromNAND(in->myDev, theChunk,
                                              tags,
                                              &chunkDeleted);
                        if (yaffs_TagsMatch
                            (tags, in->objectId, chunk, chunkDeleted)) {
                              /* found it; */

                        }
                  } else {

                        failed = 1;
                  }

            } else {
                  /* T(("No level 0 found for %d\n", chunk)); */
            }
      }

      return failed ? YAFFS_FAIL : YAFFS_OK;
}

#endif

static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
                          int chunkInNAND, int inScan)
{
      /* NB inScan is zero unless scanning.
       * For forward scanning, inScan is > 0;
       * for backward scanning inScan is < 0
       */

      yaffs_Tnode *tn;
      yaffs_Device *dev = in->myDev;
      int existingChunk;
      yaffs_ExtendedTags existingTags;
      yaffs_ExtendedTags newTags;
      unsigned existingSerial, newSerial;

      if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
            /* Just ignore an attempt at putting a chunk into a non-file during scanning
             * If it is not during Scanning then something went wrong!
             */
            if (!inScan) {
                  T(YAFFS_TRACE_ERROR,
                    (TSTR
                     ("yaffs tragedy:attempt to put data chunk into a non-file"
                      TENDSTR)));
                  YBUG();
            }

            yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
            return YAFFS_OK;
      }

      tn = yaffs_AddOrFindLevel0Tnode(dev,
                              &in->variant.fileVariant,
                              chunkInInode,
                              NULL);
      if (!tn) {
            return YAFFS_FAIL;
      }

      existingChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);

      if (inScan != 0) {
            /* If we're scanning then we need to test for duplicates
             * NB This does not need to be efficient since it should only ever
             * happen when the power fails during a write, then only one
             * chunk should ever be affected.
             *
             * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
             * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
             */

            if (existingChunk != 0) {
                  /* NB Right now existing chunk will not be real chunkId if the device >= 32MB
                   *    thus we have to do a FindChunkInFile to get the real chunk id.
                   *
                   * We have a duplicate now we need to decide which one to use:
                   *
                   * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
                   * Forward scanning YAFFS2: The new one is what we use, dump the old one.
                   * YAFFS1: Get both sets of tags and compare serial numbers.
                   */

                  if (inScan > 0) {
                        /* Only do this for forward scanning */
                        yaffs_ReadChunkWithTagsFromNAND(dev,
                                                chunkInNAND,
                                                NULL, &newTags);

                        /* Do a proper find */
                        existingChunk =
                            yaffs_FindChunkInFile(in, chunkInInode,
                                            &existingTags);
                  }

                  if (existingChunk <= 0) {
                        /*Hoosterman - how did this happen? */

                        T(YAFFS_TRACE_ERROR,
                          (TSTR
                           ("yaffs tragedy: existing chunk < 0 in scan"
                            TENDSTR)));

                  }

                  /* NB The deleted flags should be false, otherwise the chunks will
                   * not be loaded during a scan
                   */

                  newSerial = newTags.serialNumber;
                  existingSerial = existingTags.serialNumber;

                  if ((inScan > 0) &&
                      (in->myDev->isYaffs2 ||
                       existingChunk <= 0 ||
                       ((existingSerial + 1) & 3) == newSerial)) {
                        /* Forward scanning.
                         * Use new
                         * Delete the old one and drop through to update the tnode
                         */
                        yaffs_DeleteChunk(dev, existingChunk, 1,
                                      __LINE__);
                  } else {
                        /* Backward scanning or we want to use the existing one
                         * Use existing.
                         * Delete the new one and return early so that the tnode isn't changed
                         */
                        yaffs_DeleteChunk(dev, chunkInNAND, 1,
                                      __LINE__);
                        return YAFFS_OK;
                  }
            }

      }

      if (existingChunk == 0) {
            in->nDataChunks++;
      }

      yaffs_PutLevel0Tnode(dev,tn,chunkInInode,chunkInNAND);

      return YAFFS_OK;
}

static int yaffs_ReadChunkDataFromObject(yaffs_Object * in, int chunkInInode,
                               __u8 * buffer)
{
      int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);

      if (chunkInNAND >= 0) {
            return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
                                           buffer,NULL);
      } else {
            T(YAFFS_TRACE_NANDACCESS,
              (TSTR("Chunk %d not found zero instead" TENDSTR),
               chunkInNAND));
            /* get sane (zero) data if you read a hole */
            memset(buffer, 0, in->myDev->nDataBytesPerChunk);
            return 0;
      }

}

void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn)
{
      int block;
      int page;
      yaffs_ExtendedTags tags;
      yaffs_BlockInfo *bi;

      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,
        (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));

      if (markNAND &&
          bi->blockState != YAFFS_BLOCK_STATE_COLLECTING && !dev->isYaffs2) {

            yaffs_InitialiseTags(&tags);

            tags.chunkDeleted = 1;

            yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
            yaffs_HandleUpdateChunk(dev, chunkId, &tags);
      } else {
            dev->nUnmarkedDeletions++;
      }

      /* Pull out of the management area.
       * If the whole block became dirty, this will kick off an erasure.
       */
      if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
          bi->blockState == YAFFS_BLOCK_STATE_FULL ||
          bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
          bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
            dev->nFreeChunks++;

            yaffs_ClearChunkBit(dev, block, page);

            bi->pagesInUse--;

            if (bi->pagesInUse == 0 &&
                !bi->hasShrinkHeader &&
                bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
                bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
                  yaffs_BlockBecameDirty(dev, block);
            }

      } else {
            /* T(("Bad news deleting chunk %d\n",chunkId)); */
      }

}

static int yaffs_WriteChunkDataToObject(yaffs_Object * in, int chunkInInode,
                              const __u8 * buffer, int nBytes,
                              int useReserve)
{
      /* Find old chunk Need to do this to get serial number
       * Write new one and patch into tree.
       * Invalidate old tags.
       */

      int prevChunkId;
      yaffs_ExtendedTags prevTags;

      int newChunkId;
      yaffs_ExtendedTags newTags;

      yaffs_Device *dev = in->myDev;

      yaffs_CheckGarbageCollection(dev);

      /* Get the previous chunk at this location in the file if it exists */
      prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);

      /* Set up new tags */
      yaffs_InitialiseTags(&newTags);

      newTags.chunkId = chunkInInode;
      newTags.objectId = in->objectId;
      newTags.serialNumber =
          (prevChunkId >= 0) ? prevTags.serialNumber + 1 : 1;
      newTags.byteCount = nBytes;

      newChunkId =
          yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
                                    useReserve);

      if (newChunkId >= 0) {
            yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);

            if (prevChunkId >= 0) {
                  yaffs_DeleteChunk(dev, prevChunkId, 1, __LINE__);

            }

            yaffs_CheckFileSanity(in);
      }
      return newChunkId;

}

/* UpdateObjectHeader updates the header on NAND for an object.
 * If name is not NULL, then that new name is used.
 */
int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
                       int isShrink, int shadows)
{

      yaffs_BlockInfo *bi;

      yaffs_Device *dev = in->myDev;

      int prevChunkId;
      int retVal = 0;
      int result = 0;

      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;

            prevChunkId = in->chunkId;

            if (prevChunkId >= 0) {
                  result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
                                          buffer, &oldTags);

                  yaffs_VerifyObjectHeader(in,oh,&oldTags,0);

                  memcpy(oldName, oh->name, sizeof(oh->name));
            }

            memset(buffer, 0xFF, dev->nDataBytesPerChunk);

            oh->type = in->variantType;
            oh->yst_mode = in->yst_mode;
            oh->shadowsObject = shadows;

#ifdef CONFIG_YAFFS_WINCE
            oh->win_atime[0] = in->win_atime[0];
            oh->win_ctime[0] = in->win_ctime[0];
            oh->win_mtime[0] = in->win_mtime[0];
            oh->win_atime[1] = in->win_atime[1];
            oh->win_ctime[1] = in->win_ctime[1];
            oh->win_mtime[1] = in->win_mtime[1];
#else
            oh->yst_uid = in->yst_uid;
            oh->yst_gid = in->yst_gid;
            oh->yst_atime = in->yst_atime;
            oh->yst_mtime = in->yst_mtime;
            oh->yst_ctime = in->yst_ctime;
            oh->yst_rdev = in->yst_rdev;
#endif
            if (in->parent) {
                  oh->parentObjectId = in->parent->objectId;
            } else {
                  oh->parentObjectId = 0;
            }

            if (name && *name) {
                  memset(oh->name, 0, sizeof(oh->name));
                  yaffs_strncpy(oh->name, name, YAFFS_MAX_NAME_LENGTH);
            } else if (prevChunkId>=0) {
                  memcpy(oh->name, oldName, sizeof(oh->name));
            } else {
                  memset(oh->name, 0, sizeof(oh->name));
            }

            oh->isShrink = isShrink;

            switch (in->variantType) {
            case YAFFS_OBJECT_TYPE_UNKNOWN:
                  /* Should not happen */
                  break;
            case YAFFS_OBJECT_TYPE_FILE:
                  oh->fileSize =
                      (oh->parentObjectId == YAFFS_OBJECTID_DELETED
                       || oh->parentObjectId ==
                       YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.
                      fileVariant.fileSize;
                  break;
            case YAFFS_OBJECT_TYPE_HARDLINK:
                  oh->equivalentObjectId =
                      in->variant.hardLinkVariant.equivalentObjectId;
                  break;
            case YAFFS_OBJECT_TYPE_SPECIAL:
                  /* Do nothing */
                  break;
            case YAFFS_OBJECT_TYPE_DIRECTORY:
                  /* Do nothing */
                  break;
            case YAFFS_OBJECT_TYPE_SYMLINK:
                  yaffs_strncpy(oh->alias,
                              in->variant.symLinkVariant.alias,
                              YAFFS_MAX_ALIAS_LENGTH);
                  oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
                  break;
            }

            /* Tags */
            yaffs_InitialiseTags(&newTags);
            in->serial++;
            newTags.chunkId = 0;
            newTags.objectId = in->objectId;
            newTags.serialNumber = in->serial;

            /* Add extra info for file header */

            newTags.extraHeaderInfoAvailable = 1;
            newTags.extraParentObjectId = oh->parentObjectId;
            newTags.extraFileLength = oh->fileSize;
            newTags.extraIsShrinkHeader = oh->isShrink;
            newTags.extraEquivalentObjectId = oh->equivalentObjectId;
            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,
                                          (prevChunkId >= 0) ? 1 : 0);

            if (newChunkId >= 0) {

                  in->chunkId = newChunkId;

                  if (prevChunkId >= 0) {
                        yaffs_DeleteChunk(dev, prevChunkId, 1,
                                      __LINE__);
                  }

                  if(!yaffs_ObjectHasCachedWriteData(in))
                        in->dirty = 0;

                  /* If this was a shrink, then mark the block that the chunk lives on */
                  if (isShrink) {
                        bi = yaffs_GetBlockInfo(in->myDev,
                                          newChunkId /in->myDev-> nChunksPerBlock);
                        bi->hasShrinkHeader = 1;
                  }

            }

            retVal = newChunkId;

      }

      if (buffer)
            yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);

      return retVal;
}

/*------------------------ Short Operations Cache ----------------------------------------
 *   In many situations where there is no high level buffering (eg WinCE) a lot of
 *   reads might be short sequential reads, and a lot of writes may be short
 *   sequential writes. eg. scanning/writing a jpeg file.
 *   In these cases, a short read/write cache can provide a huge perfomance benefit
 *   with dumb-as-a-rock code.
 *   In Linux, the page cache provides read buffering aand the short op cache provides write
 *   buffering.
 *
 *   There are a limited number (~10) of cache chunks per device so that we don't
 *   need a very intelligent search.
 */

static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj)
{
      yaffs_Device *dev = obj->myDev;
      int i;
      yaffs_ChunkCache *cache;
      int nCaches = obj->myDev->nShortOpCaches;

      for(i = 0; i < nCaches; i++){
            cache = &dev->srCache[i];
            if (cache->object == obj &&
                cache->dirty)
                  return 1;
      }

      return 0;
}


static void yaffs_FlushFilesChunkCache(yaffs_Object * obj)
{
      yaffs_Device *dev = obj->myDev;
      int lowest = -99; /* Stop compiler whining. */
      int i;
      yaffs_ChunkCache *cache;
      int chunkWritten = 0;
      int nCaches = obj->myDev->nShortOpCaches;

      if (nCaches > 0) {
            do {
                  cache = NULL;

                  /* Find the dirty cache for this object with the lowest chunk id. */
                  for (i = 0; i < nCaches; i++) {
                        if (dev->srCache[i].object == obj &&
                            dev->srCache[i].dirty) {
                              if (!cache
                                  || dev->srCache[i].chunkId <
                                  lowest) {
                                    cache = &dev->srCache[i];
                                    lowest = cache->chunkId;
                              }
                        }
                  }

                  if (cache && !cache->locked) {
                        /* Write it out and free it up */

                        chunkWritten =
                            yaffs_WriteChunkDataToObject(cache->object,
                                                 cache->chunkId,
                                                 cache->data,
                                                 cache->nBytes,
                                                 1);
                        cache->dirty = 0;
                        cache->object = NULL;
                  }

            } while (cache && chunkWritten > 0);

            if (cache) {
                  /* Hoosterman, disk full while writing cache out. */
                  T(YAFFS_TRACE_ERROR,
                    (TSTR("yaffs tragedy: no space during cache write" TENDSTR)));

            }
      }

}

/*yaffs_FlushEntireDeviceCache(dev)
 *
 *
 */

void yaffs_FlushEntireDeviceCache(yaffs_Device *dev)
{
      yaffs_Object *obj;
      int nCaches = dev->nShortOpCaches;
      int i;

      /* Find a dirty object in the cache and flush it...
       * until there are no further dirty objects.
       */
      do {
            obj = NULL;
            for( i = 0; i < nCaches && !obj; i++) {
                  if (dev->srCache[i].object &&
                      dev->srCache[i].dirty)
                        obj = dev->srCache[i].object;

            }
            if(obj)
                  yaffs_FlushFilesChunkCache(obj);

      } while(obj);

}


/* Grab us a cache chunk for use.
 * First look for an empty one.
 * Then look for the least recently used non-dirty one.
 * Then look for the least recently used dirty one...., flush and look again.
 */
static yaffs_ChunkCache *yaffs_GrabChunkCacheWorker(yaffs_Device * dev)
{
      int i;
      int usage;
      int theOne;

      if (dev->nShortOpCaches > 0) {
            for (i = 0; i < dev->nShortOpCaches; i++) {
                  if (!dev->srCache[i].object)
                        return &dev->srCache[i];
            }

            return NULL;

            theOne = -1;
            usage = 0;  /* just to stop the compiler grizzling */

            for (i = 0; i < dev->nShortOpCaches; i++) {
                  if (!dev->srCache[i].dirty &&
                      ((dev->srCache[i].lastUse < usage && theOne >= 0) ||
                       theOne < 0)) {
                        usage = dev->srCache[i].lastUse;
                        theOne = i;
                  }
            }


            return theOne >= 0 ? &dev->srCache[theOne] : NULL;
      } else {
            return NULL;
      }

}

static yaffs_ChunkCache *yaffs_GrabChunkCache(yaffs_Device * dev)
{
      yaffs_ChunkCache *cache;
      yaffs_Object *theObj;
      int usage;
      int i;
      int pushout;

      if (dev->nShortOpCaches > 0) {
            /* Try find a non-dirty one... */

            cache = yaffs_GrabChunkCacheWorker(dev);

            if (!cache) {
                  /* They were all dirty, find the last recently used object and flush
                   * its cache, then  find again.
                   * NB what's here is not very accurate, we actually flush the object
                   * the last recently used page.
                   */

                  /* With locking we can't assume we can use entry zero */

                  theObj = NULL;
                  usage = -1;
                  cache = NULL;
                  pushout = -1;

                  for (i = 0; i < dev->nShortOpCaches; i++) {
                        if (dev->srCache[i].object &&
                            !dev->srCache[i].locked &&
                            (dev->srCache[i].lastUse < usage || !cache))
                        {
                              usage = dev->srCache[i].lastUse;
                              theObj = dev->srCache[i].object;
                              cache = &dev->srCache[i];
                              pushout = i;
                        }
                  }

                  if (!cache || cache->dirty) {
                        /* Flush and try again */
                        yaffs_FlushFilesChunkCache(theObj);
                        cache = yaffs_GrabChunkCacheWorker(dev);
                  }

            }
            return cache;
      } else
            return NULL;

}

/* Find a cached chunk */
static yaffs_ChunkCache *yaffs_FindChunkCache(const yaffs_Object * obj,
                                    int chunkId)
{
      yaffs_Device *dev = obj->myDev;
      int i;
      if (dev->nShortOpCaches > 0) {
            for (i = 0; i < dev->nShortOpCaches; i++) {
                  if (dev->srCache[i].object == obj &&
                      dev->srCache[i].chunkId == chunkId) {
                        dev->cacheHits++;

                        return &dev->srCache[i];
                  }
            }
      }
      return NULL;
}

/* Mark the chunk for the least recently used algorithym */
static void yaffs_UseChunkCache(yaffs_Device * dev, yaffs_ChunkCache * cache,
                        int isAWrite)
{

      if (dev->nShortOpCaches > 0) {
            if (dev->srLastUse < 0 || dev->srLastUse > 100000000) {
                  /* Reset the cache usages */
                  int i;
                  for (i = 1; i < dev->nShortOpCaches; i++) {
                        dev->srCache[i].lastUse = 0;
                  }
                  dev->srLastUse = 0;
            }

            dev->srLastUse++;

            cache->lastUse = dev->srLastUse;

            if (isAWrite) {
                  cache->dirty = 1;
            }
      }
}

/* Invalidate a single cache page.
 * Do this when a whole page gets written,
 * ie the short cache for this page is no longer valid.
 */
static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId)
{
      if (object->myDev->nShortOpCaches > 0) {
            yaffs_ChunkCache *cache = yaffs_FindChunkCache(object, chunkId);

            if (cache) {
                  cache->object = NULL;
            }
      }
}

/* Invalidate all the cache pages associated with this object
 * Do this whenever ther file is deleted or resized.
 */
static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in)
{
      int i;
      yaffs_Device *dev = in->myDev;

      if (dev->nShortOpCaches > 0) {
            /* Invalidate it. */
            for (i = 0; i < dev->nShortOpCaches; i++) {
                  if (dev->srCache[i].object == in) {
                        dev->srCache[i].object = NULL;
                  }
            }
      }
}

/*--------------------- Checkpointing --------------------*/


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;
      cp.head = (head) ? 1 : 0;

      return (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp))?
            1 : 0;
}

static int yaffs_ReadCheckpointValidityMarker(yaffs_Device *dev, int head)
{
      yaffs_CheckpointValidity cp;
      int ok;

      ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));

      if(ok)
            ok = (cp.structType == sizeof(cp)) &&
                 (cp.magic == YAFFS_MAGIC) &&
                 (cp.version == YAFFS_CHECKPOINT_VERSION) &&
                 (cp.head == ((head) ? 1 : 0));
      return ok ? 1 : 0;
}

static void yaffs_DeviceToCheckpointDevice(yaffs_CheckpointDevice *cp,
                                 yaffs_Device *dev)
{
      cp->nErasedBlocks = dev->nErasedBlocks;
      cp->allocationBlock = dev->allocationBlock;
      cp->allocationPage = dev->allocationPage;
      cp->nFreeChunks = dev->nFreeChunks;

      cp->nDeletedFiles = dev->nDeletedFiles;
      cp->nUnlinkedFiles = dev->nUnlinkedFiles;
      cp->nBackgroundDeletions = dev->nBackgroundDeletions;
      cp->sequenceNumber = dev->sequenceNumber;
      cp->oldestDirtySequence = dev->oldestDirtySequence;

}

static void yaffs_CheckpointDeviceToDevice(yaffs_Device *dev,
                                 yaffs_CheckpointDevice *cp)
{
      dev->nErasedBlocks = cp->nErasedBlocks;
      dev->allocationBlock = cp->allocationBlock;
      dev->allocationPage = cp->allocationPage;
      dev->nFreeChunks = cp->nFreeChunks;

      dev->nDeletedFiles = cp->nDeletedFiles;
      dev->nUnlinkedFiles = cp->nUnlinkedFiles;
      dev->nBackgroundDeletions = cp->nBackgroundDeletions;
      dev->sequenceNumber = cp->sequenceNumber;
      dev->oldestDirtySequence = cp->oldestDirtySequence;
}


static int yaffs_WriteCheckpointDevice(yaffs_Device *dev)
{
      yaffs_CheckpointDevice cp;
      __u32 nBytes;
      __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);

      int ok;

      /* Write device runtime values*/
      yaffs_DeviceToCheckpointDevice(&cp,dev);
      cp.structType = sizeof(cp);

      ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));

      /* Write block info */
      if(ok) {
            nBytes = nBlocks * sizeof(yaffs_BlockInfo);
            ok = (yaffs_CheckpointWrite(dev,dev->blockInfo,nBytes) == nBytes);
      }

      /* Write chunk bits */
      if(ok) {
            nBytes = nBlocks * dev->chunkBitmapStride;
            ok = (yaffs_CheckpointWrite(dev,dev->chunkBits,nBytes) == nBytes);
      }
      return       ok ? 1 : 0;

}

static int yaffs_ReadCheckpointDevice(yaffs_Device *dev)
{
      yaffs_CheckpointDevice cp;
      __u32 nBytes;
      __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);

      int ok;

      ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
      if(!ok)
            return 0;

      if(cp.structType != sizeof(cp))
            return 0;


      yaffs_CheckpointDeviceToDevice(dev,&cp);

      nBytes = nBlocks * sizeof(yaffs_BlockInfo);

      ok = (yaffs_CheckpointRead(dev,dev->blockInfo,nBytes) == nBytes);

      if(!ok)
            return 0;
      nBytes = nBlocks * dev->chunkBitmapStride;

      ok = (yaffs_CheckpointRead(dev,dev->chunkBits,nBytes) == nBytes);

      return ok ? 1 : 0;
}

static void yaffs_ObjectToCheckpointObject(yaffs_CheckpointObject *cp,
                                 yaffs_Object *obj)
{

      cp->objectId = obj->objectId;
      cp->parentId = (obj->parent) ? obj->parent->objectId : 0;
      cp->chunkId = obj->chunkId;
      cp->variantType = obj->variantType;
      cp->deleted = obj->deleted;
      cp->softDeleted = obj->softDeleted;
      cp->unlinked = obj->unlinked;
      cp->fake = obj->fake;
      cp->renameAllowed = obj->renameAllowed;
      cp->unlinkAllowed = obj->unlinkAllowed;
      cp->serial = obj->serial;
      cp->nDataChunks = obj->nDataChunks;

      if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
            cp->fileSizeOrEquivalentObjectId = obj->variant.fileVariant.fileSize;
      else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
            cp->fileSizeOrEquivalentObjectId = obj->variant.hardLinkVariant.equivalentObjectId;
}

static void yaffs_CheckpointObjectToObject( yaffs_Object *obj,yaffs_CheckpointObject *cp)
{

      yaffs_Object *parent;

      obj->objectId = cp->objectId;

      if(cp->parentId)
            parent = yaffs_FindOrCreateObjectByNumber(
                              obj->myDev,
                              cp->parentId,
                              YAFFS_OBJECT_TYPE_DIRECTORY);
      else
            parent = NULL;

      if(parent)
            yaffs_AddObjectToDirectory(parent, obj);

      obj->chunkId = cp->chunkId;
      obj->variantType = cp->variantType;
      obj->deleted = cp->deleted;
      obj->softDeleted = cp->softDeleted;
      obj->unlinked = cp->unlinked;
      obj->fake = cp->fake;
      obj->renameAllowed = cp->renameAllowed;
      obj->unlinkAllowed = cp->unlinkAllowed;
      obj->serial = cp->serial;
      obj->nDataChunks = cp->nDataChunks;

      if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
            obj->variant.fileVariant.fileSize = cp->fileSizeOrEquivalentObjectId;
      else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
            obj->variant.hardLinkVariant.equivalentObjectId = cp->fileSizeOrEquivalentObjectId;

      if(obj->objectId >= YAFFS_NOBJECT_BUCKETS)
            obj->lazyLoaded = 1;
}



static int yaffs_CheckpointTnodeWorker(yaffs_Object * in, yaffs_Tnode * tn,
                              __u32 level, int chunkOffset)
{
      int i;
      yaffs_Device *dev = in->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_CheckpointTnodeWorker(in,
                                          tn->internal[i],
                                          level - 1,
                                          (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
                        }
                  }
            } else if (level == 0) {
                  __u32 baseOffset = chunkOffset <<  YAFFS_TNODES_LEVEL0_BITS;
                  /* printf("write tnode at %d\n",baseOffset); */
                  ok = (yaffs_CheckpointWrite(dev,&baseOffset,sizeof(baseOffset)) == sizeof(baseOffset));
                  if(ok)
                        ok = (yaffs_CheckpointWrite(dev,tn,nTnodeBytes) == nTnodeBytes);
            }
      }

      return ok;

}

static int yaffs_WriteCheckpointTnodes(yaffs_Object *obj)
{
      __u32 endMarker = ~0;
      int ok = 1;

      if(obj->variantType == YAFFS_OBJECT_TYPE_FILE){
            ok = yaffs_CheckpointTnodeWorker(obj,
                                  obj->variant.fileVariant.top,
                                  obj->variant.fileVariant.topLevel,
                                  0);
            if(ok)
                  ok = (yaffs_CheckpointWrite(obj->myDev,&endMarker,sizeof(endMarker)) ==
                        sizeof(endMarker));
      }

      return ok ? 1 : 0;
}

static int yaffs_ReadCheckpointTnodes(yaffs_Object *obj)
{
      __u32 baseChunk;
      int ok = 1;
      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)
                  ok = (yaffs_CheckpointRead(dev,tn,(dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8) ==
                        (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
            else
                  ok = 0;

            if(tn && ok){
                  ok = yaffs_AddOrFindLevel0Tnode(dev,
                                          fileStructPtr,
                                          baseChunk,
                                          tn) ? 1 : 0;

            }

            if(ok)
                  ok = (yaffs_CheckpointRead(dev,&baseChunk,sizeof(baseChunk)) == sizeof(baseChunk));

      }

      T(YAFFS_TRACE_CHECKPOINT,(
            TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
            nread,baseChunk,ok));

      return ok ? 1 : 0;
}


static int yaffs_WriteCheckpointObjects(yaffs_Device *dev)
{
      yaffs_Object *obj;
      yaffs_CheckpointObject cp;
      int i;
      int ok = 1;
      struct list_head *lh;


      /* Iterate through the objects in each hash entry,
       * dumping them to the checkpointing stream.
       */

       for(i = 0; ok &&  i <  YAFFS_NOBJECT_BUCKETS; i++){
            list_for_each(lh, &dev->objectBucket[i].list) {
                  if (lh) {
                        obj = list_entry(lh, yaffs_Object, hashLink);
                        if (!obj->deferedFree) {
                              yaffs_ObjectToCheckpointObject(&cp,obj);
                              cp.structType = sizeof(cp);

                              T(YAFFS_TRACE_CHECKPOINT,(
                                    TSTR("Checkpoint write object %d parent %d type %d chunk %d obj addr %x" TENDSTR),
                                    cp.objectId,cp.parentId,cp.variantType,cp.chunkId,(unsigned) obj));

                              ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));

                              if(ok && obj->variantType == YAFFS_OBJECT_TYPE_FILE){
                                    ok = yaffs_WriteCheckpointTnodes(obj);
                              }
                        }
                  }
            }
       }

       /* Dump end of list */
      memset(&cp,0xFF,sizeof(yaffs_CheckpointObject));
      cp.structType = sizeof(cp);

      if(ok)
            ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));

      return ok ? 1 : 0;
}

static int yaffs_ReadCheckpointObjects(yaffs_Device *dev)
{
      yaffs_Object *obj;
      yaffs_CheckpointObject cp;
      int ok = 1;
      int done = 0;
      yaffs_Object *hardList = NULL;

      while(ok && !done) {
            ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
            if(cp.structType != sizeof(cp)) {
                  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);
                  if(obj) {
                        yaffs_CheckpointObjectToObject(obj,&cp);
                        if(obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
                              ok = yaffs_ReadCheckpointTnodes(obj);
                        } else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
                              obj->hardLinks.next =
                                        (struct list_head *)
                                        hardList;
                              hardList = obj;
                        }

                  }
            }
      }

      if(ok)
            yaffs_HardlinkFixup(dev,hardList);

      return ok ? 1 : 0;
}

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;

      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){
            T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint device" TENDSTR)));
            ok = yaffs_WriteCheckpointDevice(dev);
      }
      if(ok){
            T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint objects" TENDSTR)));
            ok = yaffs_WriteCheckpointObjects(dev);
      }
      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;

      if(ok)
            dev->isCheckpointed = 1;
       else
            dev->isCheckpointed = 0;

      return dev->isCheckpointed;
}

static int yaffs_ReadCheckpointData(yaffs_Device *dev)
{
      int ok = 1;

      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){
            T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint device" TENDSTR)));
            ok = yaffs_ReadCheckpointDevice(dev);
      }
      if(ok){
            T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint objects" TENDSTR)));
            ok = yaffs_ReadCheckpointObjects(dev);
      }
      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;

      if(ok)
            dev->isCheckpointed = 1;
       else
            dev->isCheckpointed = 0;

      return ok ? 1 : 0;

}

static void yaffs_InvalidateCheckpoint(yaffs_Device *dev)
{
      if(dev->isCheckpointed ||
         dev->blocksInCheckpoint > 0){
            dev->isCheckpointed = 0;
            yaffs_CheckpointInvalidateStream(dev);
            if(dev->superBlock && dev->markSuperBlockDirty)
                  dev->markSuperBlockDirty(dev->superBlock);
      }
}


int yaffs_CheckpointSave(yaffs_Device *dev)
{

      T(YAFFS_TRACE_CHECKPOINT,(TSTR("save entry: isCheckpointed %d"TENDSTR),dev->isCheckpointed));

      yaffs_VerifyObjects(dev);
      yaffs_VerifyBlocks(dev);
      yaffs_VerifyFreeChunks(dev);

      if(!dev->isCheckpointed) {
            yaffs_InvalidateCheckpoint(dev);
            yaffs_WriteCheckpointData(dev);
      }

      T(YAFFS_TRACE_ALWAYS,(TSTR("save exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));

      return dev->isCheckpointed;
}

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));

      return retval;
}

/*--------------------- File read/write ------------------------
 * Read and write have very similar structures.
 * In general the read/write has three parts to it
 * An incomplete chunk to start with (if the read/write is not chunk-aligned)
 * Some complete chunks
 * An incomplete chunk to end off with
 *
 * Curve-balls: the first chunk might also be the last chunk.
 */

int yaffs_ReadDataFromFile(yaffs_Object * in, __u8 * buffer, loff_t offset,
                     int nBytes)
{

      int chunk;
      int start;
      int nToCopy;
      int n = nBytes;
      int nDone = 0;
      yaffs_ChunkCache *cache;

      yaffs_Device *dev;

      dev = in->myDev;

      while (n > 0) {
            //chunk = offset / dev->nDataBytesPerChunk + 1;
            //start = offset % dev->nDataBytesPerChunk;
            yaffs_AddrToChunk(dev,offset,&chunk,&start);
            chunk++;

            /* OK now check for the curveball where the start and end are in
             * the same chunk.
             */
            if ((start + n) < dev->nDataBytesPerChunk) {
                  nToCopy = n;
            } else {
                  nToCopy = dev->nDataBytesPerChunk - start;
            }

            cache = yaffs_FindChunkCache(in, chunk);

            /* If the chunk is already in the cache or it is less than a whole chunk
             * then use the cache (if there is caching)
             * else bypass the cache.
             */
            if (cache || nToCopy != dev->nDataBytesPerChunk) {
                  if (dev->nShortOpCaches > 0) {

                        /* If we can't find the data in the cache, then load it up. */

                        if (!cache) {
                              cache = yaffs_GrabChunkCache(in->myDev);
                              cache->object = in;
                              cache->chunkId = chunk;
                              cache->dirty = 0;
                              cache->locked = 0;
                              yaffs_ReadChunkDataFromObject(in, chunk,
                                                      cache->
                                                      data);
                              cache->nBytes = 0;
                        }

                        yaffs_UseChunkCache(dev, cache, 0);

                        cache->locked = 1;

#ifdef CONFIG_YAFFS_WINCE
                        yfsd_UnlockYAFFS(TRUE);
#endif
                        memcpy(buffer, &cache->data[start], nToCopy);

#ifdef CONFIG_YAFFS_WINCE
                        yfsd_LockYAFFS(TRUE);
#endif
                        cache->locked = 0;
                  } else {
                        /* Read into the local buffer then copy..*/

                        __u8 *localBuffer =
                            yaffs_GetTempBuffer(dev, __LINE__);
                        yaffs_ReadChunkDataFromObject(in, chunk,
                                                localBuffer);
#ifdef CONFIG_YAFFS_WINCE
                        yfsd_UnlockYAFFS(TRUE);
#endif
                        memcpy(buffer, &localBuffer[start], nToCopy);

#ifdef CONFIG_YAFFS_WINCE
                        yfsd_LockYAFFS(TRUE);
#endif
                        yaffs_ReleaseTempBuffer(dev, localBuffer,
                                          __LINE__);
                  }

            } else {
#ifdef CONFIG_YAFFS_WINCE
                  __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);

                  /* Under WinCE can't do direct transfer. Need to use a local buffer.
                   * This is because we otherwise screw up WinCE's memory mapper
                   */
                  yaffs_ReadChunkDataFromObject(in, chunk, localBuffer);

#ifdef CONFIG_YAFFS_WINCE
                  yfsd_UnlockYAFFS(TRUE);
#endif
                  memcpy(buffer, localBuffer, dev->nDataBytesPerChunk);

#ifdef CONFIG_YAFFS_WINCE
                  yfsd_LockYAFFS(TRUE);
                  yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
#endif

#else
                  /* A full chunk. Read directly into the supplied buffer. */
                  yaffs_ReadChunkDataFromObject(in, chunk, buffer);
#endif
            }

            n -= nToCopy;
            offset += nToCopy;
            buffer += nToCopy;
            nDone += nToCopy;

      }

      return nDone;
}

int yaffs_WriteDataToFile(yaffs_Object * in, const __u8 * buffer, loff_t offset,
                    int nBytes, int writeThrough)
{

      int chunk;
      int start;
      int nToCopy;
      int n = nBytes;
      int nDone = 0;
      int nToWriteBack;
      int startOfWrite = offset;
      int chunkWritten = 0;
      int nBytesRead;

      yaffs_Device *dev;

      dev = in->myDev;

      while (n > 0 && chunkWritten >= 0) {
            //chunk = offset / dev->nDataBytesPerChunk + 1;
            //start = offset % dev->nDataBytesPerChunk;
            yaffs_AddrToChunk(dev,offset,&chunk,&start);
            chunk++;

            /* OK now check for the curveball where the start and end are in
             * the same chunk.
             */

            if ((start + n) < dev->nDataBytesPerChunk) {
                  nToCopy = n;

                  /* Now folks, to calculate how many bytes to write back....
                   * If we're overwriting and not writing to then end of file then
                   * we need to write back as much as was there before.
                   */

                  nBytesRead =
                      in->variant.fileVariant.fileSize -
                      ((chunk - 1) * dev->nDataBytesPerChunk);

                  if (nBytesRead > dev->nDataBytesPerChunk) {
                        nBytesRead = dev->nDataBytesPerChunk;
                  }

                  nToWriteBack =
                      (nBytesRead >
                       (start + n)) ? nBytesRead : (start + n);

            } else {
                  nToCopy = dev->nDataBytesPerChunk - start;
                  nToWriteBack = dev->nDataBytesPerChunk;
            }

            if (nToCopy != dev->nDataBytesPerChunk) {
                  /* An incomplete start or end chunk (or maybe both start and end chunk) */
                  if (dev->nShortOpCaches > 0) {
                        yaffs_ChunkCache *cache;
                        /* If we can't find the data in the cache, then load the cache */
                        cache = yaffs_FindChunkCache(in, chunk);

                        if (!cache
                            && yaffs_CheckSpaceForAllocation(in->
                                                     myDev)) {
                              cache = yaffs_GrabChunkCache(in->myDev);
                              cache->object = in;
                              cache->chunkId = chunk;
                              cache->dirty = 0;
                              cache->locked = 0;
                              yaffs_ReadChunkDataFromObject(in, chunk,
                                                      cache->
                                                      data);
                        }
                        else if(cache &&
                              !cache->dirty &&
                              !yaffs_CheckSpaceForAllocation(in->myDev)){
                              /* Drop the cache if it was a read cache item and
                               * no space check has been made for it.
                               */
                               cache = NULL;
                        }

                        if (cache) {
                              yaffs_UseChunkCache(dev, cache, 1);
                              cache->locked = 1;
#ifdef CONFIG_YAFFS_WINCE
                              yfsd_UnlockYAFFS(TRUE);
#endif

                              memcpy(&cache->data[start], buffer,
                                     nToCopy);

#ifdef CONFIG_YAFFS_WINCE
                              yfsd_LockYAFFS(TRUE);
#endif
                              cache->locked = 0;
                              cache->nBytes = nToWriteBack;

                              if (writeThrough) {
                                    chunkWritten =
                                        yaffs_WriteChunkDataToObject
                                        (cache->object,
                                         cache->chunkId,
                                         cache->data, cache->nBytes,
                                         1);
                                    cache->dirty = 0;
                              }

                        } else {
                              chunkWritten = -1;      /* fail the write */
                        }
                  } else {
                        /* An incomplete start or end chunk (or maybe both start and end chunk)
                         * Read into the local buffer then copy, then copy over and write back.
                         */

                        __u8 *localBuffer =
                            yaffs_GetTempBuffer(dev, __LINE__);

                        yaffs_ReadChunkDataFromObject(in, chunk,
                                                localBuffer);

#ifdef CONFIG_YAFFS_WINCE
                        yfsd_UnlockYAFFS(TRUE);
#endif

                        memcpy(&localBuffer[start], buffer, nToCopy);

#ifdef CONFIG_YAFFS_WINCE
                        yfsd_LockYAFFS(TRUE);
#endif
                        chunkWritten =
                            yaffs_WriteChunkDataToObject(in, chunk,
                                                 localBuffer,
                                                 nToWriteBack,
                                                 0);

                        yaffs_ReleaseTempBuffer(dev, localBuffer,
                                          __LINE__);

                  }

            } else {

#ifdef CONFIG_YAFFS_WINCE
                  /* Under WinCE can't do direct transfer. Need to use a local buffer.
                   * This is because we otherwise screw up WinCE's memory mapper
                   */
                  __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
#ifdef CONFIG_YAFFS_WINCE
                  yfsd_UnlockYAFFS(TRUE);
#endif
                  memcpy(localBuffer, buffer, dev->nDataBytesPerChunk);
#ifdef CONFIG_YAFFS_WINCE
                  yfsd_LockYAFFS(TRUE);
#endif
                  chunkWritten =
                      yaffs_WriteChunkDataToObject(in, chunk, localBuffer,
                                           dev->nDataBytesPerChunk,
                                           0);
                  yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
#else
                  /* A full chunk. Write directly from the supplied buffer. */
                  chunkWritten =
                      yaffs_WriteChunkDataToObject(in, chunk, buffer,
                                           dev->nDataBytesPerChunk,
                                           0);
#endif
                  /* Since we've overwritten the cached data, we better invalidate it. */
                  yaffs_InvalidateChunkCache(in, chunk);
            }

            if (chunkWritten >= 0) {
                  n -= nToCopy;
                  offset += nToCopy;
                  buffer += nToCopy;
                  nDone += nToCopy;
            }

      }

      /* Update file object */

      if ((startOfWrite + nDone) > in->variant.fileVariant.fileSize) {
            in->variant.fileVariant.fileSize = (startOfWrite + nDone);
      }

      in->dirty = 1;

      return nDone;
}


/* ---------------------- File resizing stuff ------------------ */

static void yaffs_PruneResizedChunks(yaffs_Object * in, int newSize)
{

      yaffs_Device *dev = in->myDev;
      int oldFileSize = in->variant.fileVariant.fileSize;

      int lastDel = 1 + (oldFileSize - 1) / dev->nDataBytesPerChunk;

      int startDel = 1 + (newSize + dev->nDataBytesPerChunk - 1) /
          dev->nDataBytesPerChunk;
      int i;
      int chunkId;

      /* Delete backwards so that we don't end up with holes if
       * power is lost part-way through the operation.
       */
      for (i = lastDel; i >= startDel; i--) {
            /* NB this could be optimised somewhat,
             * eg. could retrieve the tags and write them without
             * using yaffs_DeleteChunk
             */

            chunkId = yaffs_FindAndDeleteChunkInFile(in, i, NULL);
            if (chunkId > 0) {
                  if (chunkId <
                      (dev->internalStartBlock * dev->nChunksPerBlock)
                      || chunkId >=
                      ((dev->internalEndBlock +
                        1) * dev->nChunksPerBlock)) {
                        T(YAFFS_TRACE_ALWAYS,
                          (TSTR("Found daft chunkId %d for %d" TENDSTR),
                           chunkId, i));
                  } else {
                        in->nDataChunks--;
                        yaffs_DeleteChunk(dev, chunkId, 1, __LINE__);
                  }
            }
      }

}

int yaffs_ResizeFile(yaffs_Object * in, loff_t newSize)
{

      int oldFileSize = in->variant.fileVariant.fileSize;
      int newSizeOfPartialChunk;
      int newFullChunks;

      yaffs_Device *dev = in->myDev;

      yaffs_AddrToChunk(dev, newSize, &newFullChunks, &newSizeOfPartialChunk);

      yaffs_FlushFilesChunkCache(in);
      yaffs_InvalidateWholeChunkCache(in);

      yaffs_CheckGarbageCollection(dev);

      if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
            return yaffs_GetFileSize(in);
      }

      if (newSize == oldFileSize) {
            return oldFileSize;
      }

      if (newSize < oldFileSize) {

            yaffs_PruneResizedChunks(in, newSize);

            if (newSizeOfPartialChunk != 0) {
                  int lastChunk = 1 + newFullChunks;

                  __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);

                  /* Got to read and rewrite the last chunk with its new size and zero pad */
                  yaffs_ReadChunkDataFromObject(in, lastChunk,
                                          localBuffer);

                  memset(localBuffer + newSizeOfPartialChunk, 0,
                         dev->nDataBytesPerChunk - newSizeOfPartialChunk);

                  yaffs_WriteChunkDataToObject(in, lastChunk, localBuffer,
                                         newSizeOfPartialChunk, 1);

                  yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
            }

            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.
       */
      if (in->parent->objectId != YAFFS_OBJECTID_UNLINKED &&
          in->parent->objectId != YAFFS_OBJECTID_DELETED) {
            yaffs_UpdateObjectHeader(in, NULL, 0,
                               (newSize < oldFileSize) ? 1 : 0, 0);
      }

      return YAFFS_OK;
}

loff_t yaffs_GetFileSize(yaffs_Object * obj)
{
      obj = yaffs_GetEquivalentObject(obj);

      switch (obj->variantType) {
      case YAFFS_OBJECT_TYPE_FILE:
            return obj->variant.fileVariant.fileSize;
      case YAFFS_OBJECT_TYPE_SYMLINK:
            return yaffs_strlen(obj->variant.symLinkVariant.alias);
      default:
            return 0;
      }
}



int yaffs_FlushFile(yaffs_Object * in, int updateTime)
{
      int retVal;
      if (in->dirty) {
            yaffs_FlushFilesChunkCache(in);
            if (updateTime) {
#ifdef CONFIG_YAFFS_WINCE
                  yfsd_WinFileTimeNow(in->win_mtime);
#else

                  in->yst_mtime = Y_CURRENT_TIME;

#endif
            }

            retVal =
                (yaffs_UpdateObjectHeader(in, NULL, 0, 0, 0) >=
                 0) ? YAFFS_OK : YAFFS_FAIL;
      } else {
            retVal = YAFFS_OK;
      }

      return retVal;

}

static int yaffs_DoGenericObjectDeletion(yaffs_Object * in)
{

      /* First off, invalidate the file's data in the cache, without flushing. */
      yaffs_InvalidateWholeChunkCache(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,"deleted", 0, 0);

      }

      yaffs_RemoveObjectFromDirectory(in);
      yaffs_DeleteChunk(in->myDev, in->chunkId, 1, __LINE__);
      in->chunkId = -1;

      yaffs_FreeObject(in);
      return YAFFS_OK;

}

/* yaffs_DeleteFile deletes the whole file data
 * and the inode associated with the file.
 * It does not delete the links associated with the file.
 */
static int yaffs_UnlinkFile(yaffs_Object * in)
{

      int retVal;
      int immediateDeletion = 0;

      if (1) {
/* XXX U-BOOT XXX */
#if 0
#ifdef __KERNEL__
            if (!in->myInode) {
                  immediateDeletion = 1;

            }
#endif
#else
            if (in->inUse <= 0) {
                  immediateDeletion = 1;

            }
#endif
            if (immediateDeletion) {
                  retVal =
                      yaffs_ChangeObjectName(in, in->myDev->deletedDir,
                                       "deleted", 0, 0);
                  T(YAFFS_TRACE_TRACING,
                    (TSTR("yaffs: immediate deletion of file %d" TENDSTR),
                     in->objectId));
                  in->deleted = 1;
                  in->myDev->nDeletedFiles++;
                  if (0 && in->myDev->isYaffs2) {
                        yaffs_ResizeFile(in, 0);
                  }
                  yaffs_SoftDeleteFile(in);
            } else {
                  retVal =
                      yaffs_ChangeObjectName(in, in->myDev->unlinkedDir,
                                       "unlinked", 0, 0);
            }

      }
      return retVal;
}

int yaffs_DeleteFile(yaffs_Object * in)
{
      int retVal = YAFFS_OK;

      if (in->nDataChunks > 0) {
            /* Use soft deletion if there is data in the file */
            if (!in->unlinked) {
                  retVal = yaffs_UnlinkFile(in);
            }
            if (retVal == YAFFS_OK && in->unlinked && !in->deleted) {
                  in->deleted = 1;
                  in->myDev->nDeletedFiles++;
                  yaffs_SoftDeleteFile(in);
            }
            return in->deleted ? YAFFS_OK : YAFFS_FAIL;
      } else {
            /* The file has no data chunks so we toss it immediately */
            yaffs_FreeTnode(in->myDev, in->variant.fileVariant.top);
            in->variant.fileVariant.top = NULL;
            yaffs_DoGenericObjectDeletion(in);

            return YAFFS_OK;
      }
}

static int yaffs_DeleteDirectory(yaffs_Object * in)
{
      /* First check that the directory is empty. */
      if (list_empty(&in->variant.directoryVariant.children)) {
            return yaffs_DoGenericObjectDeletion(in);
      }

      return YAFFS_FAIL;

}

static int yaffs_DeleteSymLink(yaffs_Object * in)
{
      YFREE(in->variant.symLinkVariant.alias);

      return yaffs_DoGenericObjectDeletion(in);
}

static int yaffs_DeleteHardLink(yaffs_Object * in)
{
      /* remove this hardlink from the list assocaited with the equivalent
       * object
       */
      list_del(&in->hardLinks);
      return yaffs_DoGenericObjectDeletion(in);
}

static void yaffs_DestroyObject(yaffs_Object * obj)
{
      switch (obj->variantType) {
      case YAFFS_OBJECT_TYPE_FILE:
            yaffs_DeleteFile(obj);
            break;
      case YAFFS_OBJECT_TYPE_DIRECTORY:
            yaffs_DeleteDirectory(obj);
            break;
      case YAFFS_OBJECT_TYPE_SYMLINK:
            yaffs_DeleteSymLink(obj);
            break;
      case YAFFS_OBJECT_TYPE_HARDLINK:
            yaffs_DeleteHardLink(obj);
            break;
      case YAFFS_OBJECT_TYPE_SPECIAL:
            yaffs_DoGenericObjectDeletion(obj);
            break;
      case YAFFS_OBJECT_TYPE_UNKNOWN:
            break;            /* should not happen. */
      }
}

static int yaffs_UnlinkWorker(yaffs_Object * obj)
{

      if (obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
            return yaffs_DeleteHardLink(obj);
      } else if (!list_empty(&obj->hardLinks)) {
            /* Curve ball: We're unlinking an object that has a hardlink.
             *
             * This problem arises because we are not strictly following
             * The Linux link/inode model.
             *
             * We can't really delete the object.
             * Instead, we do the following:
             * - Select a hardlink.
             * - Unhook it from the hard links
             * - Unhook it from its parent directory (so that the rename can work)
             * - Rename the object to the hardlink's name.
             * - Delete the hardlink
             */

            yaffs_Object *hl;
            int retVal;
            YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];

            hl = list_entry(obj->hardLinks.next, yaffs_Object, hardLinks);

            list_del_init(&hl->hardLinks);
            list_del_init(&hl->siblings);

            yaffs_GetObjectName(hl, name, YAFFS_MAX_NAME_LENGTH + 1);

            retVal = yaffs_ChangeObjectName(obj, hl->parent, name, 0, 0);

            if (retVal == YAFFS_OK) {
                  retVal = yaffs_DoGenericObjectDeletion(hl);
            }
            return retVal;

      } else {
            switch (obj->variantType) {
            case YAFFS_OBJECT_TYPE_FILE:
                  return yaffs_UnlinkFile(obj);
                  break;
            case YAFFS_OBJECT_TYPE_DIRECTORY:
                  return yaffs_DeleteDirectory(obj);
                  break;
            case YAFFS_OBJECT_TYPE_SYMLINK:
                  return yaffs_DeleteSymLink(obj);
                  break;
            case YAFFS_OBJECT_TYPE_SPECIAL:
                  return yaffs_DoGenericObjectDeletion(obj);
                  break;
            case YAFFS_OBJECT_TYPE_HARDLINK:
            case YAFFS_OBJECT_TYPE_UNKNOWN:
            default:
                  return YAFFS_FAIL;
            }
      }
}


static int yaffs_UnlinkObject( yaffs_Object *obj)
{

      if (obj && obj->unlinkAllowed) {
            return yaffs_UnlinkWorker(obj);
      }

      return YAFFS_FAIL;

}
int yaffs_Unlink(yaffs_Object * dir, const YCHAR * name)
{
      yaffs_Object *obj;

      obj = yaffs_FindObjectByName(dir, name);
      return yaffs_UnlinkObject(obj);
}

/*----------------------- Initialisation Scanning ---------------------- */

static void yaffs_HandleShadowedObject(yaffs_Device * dev, int objId,
                               int backwardScanning)
{
      yaffs_Object *obj;

      if (!backwardScanning) {
            /* Handle YAFFS1 forward scanning case
             * For YAFFS1 we always do the deletion
             */

      } else {
            /* Handle YAFFS2 case (backward scanning)
             * If the shadowed object exists then ignore.
             */
            if (yaffs_FindObjectByNumber(dev, objId)) {
                  return;
            }
      }

      /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
       * We put it in unlinked dir to be cleaned up after the scanning
       */
      obj =
          yaffs_FindOrCreateObjectByNumber(dev, objId,
                                   YAFFS_OBJECT_TYPE_FILE);
      yaffs_AddObjectToDirectory(dev->unlinkedDir, obj);
      obj->variant.fileVariant.shrinkSize = 0;
      obj->valid = 1;         /* So that we don't read any other info for this file */

}

typedef struct {
      int seq;
      int block;
} yaffs_BlockIndex;


static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList)
{
      yaffs_Object *hl;
      yaffs_Object *in;

      while (hardList) {
            hl = hardList;
            hardList = (yaffs_Object *) (hardList->hardLinks.next);

            in = yaffs_FindObjectByNumber(dev,
                                    hl->variant.hardLinkVariant.
                                    equivalentObjectId);

            if (in) {
                  /* Add the hardlink pointers */
                  hl->variant.hardLinkVariant.equivalentObject = in;
                  list_add(&hl->hardLinks, &in->hardLinks);
            } else {
                  /* Todo Need to report/handle this better.
                   * Got a problem... hardlink to a non-existant object
                   */
                  hl->variant.hardLinkVariant.equivalentObject = NULL;
                  INIT_LIST_HEAD(&hl->hardLinks);

            }

      }

}





static int ybicmp(const void *a, const void *b){
    register int aseq = ((yaffs_BlockIndex *)a)->seq;
    register int bseq = ((yaffs_BlockIndex *)b)->seq;
    register int ablock = ((yaffs_BlockIndex *)a)->block;
    register int bblock = ((yaffs_BlockIndex *)b)->block;
    if( aseq == bseq )
      return ablock - bblock;
    else
      return aseq - bseq;

}

static int yaffs_Scan(yaffs_Device * dev)
{
      yaffs_ExtendedTags tags;
      int blk;
      int blockIterator;
      int startIterator;
      int endIterator;
      int nBlocksToScan = 0;
      int result;

      int chunk;
      int c;
      int deleted;
      yaffs_BlockState state;
      yaffs_Object *hardList = NULL;
      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;

      yaffs_BlockIndex *blockIndex = NULL;

      if (dev->isYaffs2) {
            T(YAFFS_TRACE_SCAN,
              (TSTR("yaffs_Scan is not for YAFFS2!" TENDSTR)));
            return YAFFS_FAIL;
      }

      //TODO  Throw all the yaffs2 stuuf out of yaffs_Scan since it is only for yaffs1 format.

      T(YAFFS_TRACE_SCAN,
        (TSTR("yaffs_Scan starts  intstartblk %d intendblk %d..." TENDSTR),
         dev->internalStartBlock, dev->internalEndBlock));

      chunkData = yaffs_GetTempBuffer(dev, __LINE__);

      dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;

      if (dev->isYaffs2) {
            blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));
            if(!blockIndex)
                  return YAFFS_FAIL;
      }

      /* Scan all the blocks to determine their state */
      for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
            bi = yaffs_GetBlockInfo(dev, blk);
            yaffs_ClearChunkBits(dev, blk);
            bi->pagesInUse = 0;
            bi->softDeletions = 0;

            yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);

            bi->blockState = state;
            bi->sequenceNumber = sequenceNumber;

            T(YAFFS_TRACE_SCAN_DEBUG,
              (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
               state, sequenceNumber));

            if (state == YAFFS_BLOCK_STATE_DEAD) {
                  T(YAFFS_TRACE_BAD_BLOCKS,
                    (TSTR("block %d is bad" TENDSTR), blk));
            } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
                  T(YAFFS_TRACE_SCAN_DEBUG,
                    (TSTR("Block empty " TENDSTR)));
                  dev->nErasedBlocks++;
                  dev->nFreeChunks += dev->nChunksPerBlock;
            } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {

                  /* Determine the highest sequence number */
                  if (dev->isYaffs2 &&
                      sequenceNumber >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
                      sequenceNumber < YAFFS_HIGHEST_SEQUENCE_NUMBER) {

                        blockIndex[nBlocksToScan].seq = sequenceNumber;
                        blockIndex[nBlocksToScan].block = blk;

                        nBlocksToScan++;

                        if (sequenceNumber >= dev->sequenceNumber) {
                              dev->sequenceNumber = sequenceNumber;
                        }
                  } else if (dev->isYaffs2) {
                        /* TODO: Nasty sequence number! */
                        T(YAFFS_TRACE_SCAN,
                          (TSTR
                           ("Block scanning block %d has bad sequence number %d"
                            TENDSTR), blk, sequenceNumber));

                  }
            }
      }

      /* Sort the blocks
       * Dungy old bubble sort for now...
       */
      if (dev->isYaffs2) {
            yaffs_BlockIndex temp;
            int i;
            int j;

            for (i = 0; i < nBlocksToScan; i++)
                  for (j = i + 1; j < nBlocksToScan; j++)
                        if (blockIndex[i].seq > blockIndex[j].seq) {
                              temp = blockIndex[j];
                              blockIndex[j] = blockIndex[i];
                              blockIndex[i] = temp;
                        }
      }

      /* Now scan the blocks looking at the data. */
      if (dev->isYaffs2) {
            startIterator = 0;
            endIterator = nBlocksToScan - 1;
            T(YAFFS_TRACE_SCAN_DEBUG,
              (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));
      } else {
            startIterator = dev->internalStartBlock;
            endIterator = dev->internalEndBlock;
      }

      /* For each block.... */
      for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
           blockIterator++) {

            if (dev->isYaffs2) {
                  /* get the block to scan in the correct order */
                  blk = blockIndex[blockIterator].block;
            } else {
                  blk = blockIterator;
            }

            bi = yaffs_GetBlockInfo(dev, blk);
            state = bi->blockState;

            deleted = 0;

            /* For each chunk in each block that needs scanning....*/
            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;

                  result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
                                          &tags);

                  /* Let's have a good look at this chunk... */

                  if (!dev->isYaffs2 && tags.chunkDeleted) {
                        /* YAFFS1 only...
                         * A deleted chunk
                         */
                        deleted++;
                        dev->nFreeChunks++;
                        /*T((" %d %d deleted\n",blk,c)); */
                  } else if (!tags.chunkUsed) {
                        /* An unassigned chunk in the block
                         * This means that either the block is empty or
                         * this is the one being allocated from
                         */

                        if (c == 0) {
                              /* We're looking at the first chunk in the block so the block is unused */
                              state = YAFFS_BLOCK_STATE_EMPTY;
                              dev->nErasedBlocks++;
                        } else {
                              /* 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;
                              /* 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 += (dev->nChunksPerBlock - c);
                  } else if (tags.chunkId > 0) {
                        /* chunkId > 0 so it is a data chunk... */
                        unsigned int endpos;

                        yaffs_SetChunkBit(dev, blk, c);
                        bi->pagesInUse++;

                        in = yaffs_FindOrCreateObjectByNumber(dev,
                                                      tags.
                                                      objectId,
                                                      YAFFS_OBJECT_TYPE_FILE);
                        /* PutChunkIntoFile checks for a clash (two data chunks with
                         * the same chunkId).
                         */

                        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 &&
                            in->variantType == YAFFS_OBJECT_TYPE_FILE
                            && in->variant.fileVariant.scannedFileSize <
                            endpos) {
                              in->variant.fileVariant.
                                  scannedFileSize = endpos;
                              if (!dev->useHeaderFileSize) {
                                    in->variant.fileVariant.
                                        fileSize =
                                        in->variant.fileVariant.
                                        scannedFileSize;
                              }

                        }
                        /* T((" %d %d data %d %d\n",blk,c,tags.objectId,tags.chunkId));   */
                  } else {
                        /* chunkId == 0, so it is an ObjectHeader.
                         * Thus, we read in the object header and make the object
                         */
                        yaffs_SetChunkBit(dev, blk, c);
                        bi->pagesInUse++;

                        result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk,
                                                chunkData,
                                                NULL);

                        oh = (yaffs_ObjectHeader *) chunkData;

                        in = yaffs_FindObjectByNumber(dev,
                                                tags.objectId);
                        if (in && in->variantType != oh->type) {
                              /* This should not happen, but somehow
                               * Wev'e ended up with an objectId that has been reused but not yet
                               * deleted, and worse still it has changed type. Delete the old object.
                               */

                              yaffs_DestroyObject(in);

                              in = 0;
                        }

                        in = yaffs_FindOrCreateObjectByNumber(dev,
                                                      tags.
                                                      objectId,
                                                      oh->type);

                        if(!in)
                              alloc_failed = 1;

                        if (in && oh->shadowsObject > 0) {
                              yaffs_HandleShadowedObject(dev,
                                                   oh->
                                                   shadowsObject,
                                                   0);
                        }

                        if (in && in->valid) {
                              /* We have already filled this one. We have a duplicate and need to resolve it. */

                              unsigned existingSerial = in->serial;
                              unsigned newSerial = tags.serialNumber;

                              if (dev->isYaffs2 ||
                                  ((existingSerial + 1) & 3) ==
                                  newSerial) {
                                    /* Use new one - destroy the exisiting one */
                                    yaffs_DeleteChunk(dev,
                                                  in->chunkId,
                                                  1, __LINE__);
                                    in->valid = 0;
                              } else {
                                    /* Use existing - destroy this one. */
                                    yaffs_DeleteChunk(dev, chunk, 1,
                                                  __LINE__);
                              }
                        }

                        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 */
                              in->valid = 1;
                              in->variantType = oh->type;

                              in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
                              in->win_atime[0] = oh->win_atime[0];
                              in->win_ctime[0] = oh->win_ctime[0];
                              in->win_mtime[0] = oh->win_mtime[0];
                              in->win_atime[1] = oh->win_atime[1];
                              in->win_ctime[1] = oh->win_ctime[1];
                              in->win_mtime[1] = oh->win_mtime[1];
#else
                              in->yst_uid = oh->yst_uid;
                              in->yst_gid = oh->yst_gid;
                              in->yst_atime = oh->yst_atime;
                              in->yst_mtime = oh->yst_mtime;
                              in->yst_ctime = oh->yst_ctime;
                              in->yst_rdev = oh->yst_rdev;
#endif
                              in->chunkId = chunk;

                        } else if (in && !in->valid) {
                              /* we need to load this info */

                              in->valid = 1;
                              in->variantType = oh->type;

                              in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
                              in->win_atime[0] = oh->win_atime[0];
                              in->win_ctime[0] = oh->win_ctime[0];
                              in->win_mtime[0] = oh->win_mtime[0];
                              in->win_atime[1] = oh->win_atime[1];
                              in->win_ctime[1] = oh->win_ctime[1];
                              in->win_mtime[1] = oh->win_mtime[1];
#else
                              in->yst_uid = oh->yst_uid;
                              in->yst_gid = oh->yst_gid;
                              in->yst_atime = oh->yst_atime;
                              in->yst_mtime = oh->yst_mtime;
                              in->yst_ctime = oh->yst_ctime;
                              in->yst_rdev = oh->yst_rdev;
#endif
                              in->chunkId = chunk;

                              yaffs_SetObjectName(in, oh->name);
                              in->dirty = 0;

                              /* directory stuff...
                               * hook up to parent
                               */

                              parent =
                                  yaffs_FindOrCreateObjectByNumber
                                  (dev, oh->parentObjectId,
                                   YAFFS_OBJECT_TYPE_DIRECTORY);
                              if (parent->variantType ==
                                  YAFFS_OBJECT_TYPE_UNKNOWN) {
                                    /* Set up as a directory */
                                    parent->variantType =
                                        YAFFS_OBJECT_TYPE_DIRECTORY;
                                    INIT_LIST_HEAD(&parent->variant.
                                                 directoryVariant.
                                                 children);
                              } else if (parent->variantType !=
                                       YAFFS_OBJECT_TYPE_DIRECTORY)
                              {
                                    /* Hoosterman, another problem....
                                     * We're trying to use a non-directory as a directory
                                     */

                                    T(YAFFS_TRACE_ERROR,
                                      (TSTR
                                       ("yaffs tragedy: attempting to use non-directory as"
                                        " a directory in scan. Put in lost+found."
                                        TENDSTR)));
                                    parent = dev->lostNFoundDir;
                              }

                              yaffs_AddObjectToDirectory(parent, in);

                              if (0 && (parent == dev->deletedDir ||
                                      parent == dev->unlinkedDir)) {
                                    in->deleted = 1;  /* If it is unlinked at start up then it wants deleting */
                                    dev->nDeletedFiles++;
                              }
                              /* Note re hardlinks.
                               * Since we might scan a hardlink before its equivalent object is scanned
                               * we put them all in a list.
                               * After scanning is complete, we should have all the objects, so we run through this
                               * list and fix up all the chains.
                               */

                              switch (in->variantType) {
                              case YAFFS_OBJECT_TYPE_UNKNOWN:
                                    /* Todo got a problem */
                                    break;
                              case YAFFS_OBJECT_TYPE_FILE:
                                    if (dev->isYaffs2
                                        && oh->isShrink) {
                                          /* Prune back the shrunken chunks */
                                          yaffs_PruneResizedChunks
                                              (in, oh->fileSize);
                                          /* Mark the block as having a shrinkHeader */
                                          bi->hasShrinkHeader = 1;
                                    }

                                    if (dev->useHeaderFileSize)

                                          in->variant.fileVariant.
                                              fileSize =
                                              oh->fileSize;

                                    break;
                              case YAFFS_OBJECT_TYPE_HARDLINK:
                                    in->variant.hardLinkVariant.
                                        equivalentObjectId =
                                        oh->equivalentObjectId;
                                    in->hardLinks.next =
                                        (struct list_head *)
                                        hardList;
                                    hardList = in;
                                    break;
                              case YAFFS_OBJECT_TYPE_DIRECTORY:
                                    /* Do nothing */
                                    break;
                              case YAFFS_OBJECT_TYPE_SPECIAL:
                                    /* Do nothing */
                                    break;
                              case YAFFS_OBJECT_TYPE_SYMLINK:
                                    in->variant.symLinkVariant.alias =
                                        yaffs_CloneString(oh->alias);
                                    if(!in->variant.symLinkVariant.alias)
                                          alloc_failed = 1;
                                    break;
                              }

                              if (parent == dev->deletedDir) {
                                    yaffs_DestroyObject(in);
                                    bi->hasShrinkHeader = 1;
                              }
                        }
                  }
            }

            if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
                  /* If we got this far while scanning, then the block is fully allocated.*/
                  state = YAFFS_BLOCK_STATE_FULL;
            }

            bi->blockState = state;

            /* Now let's see if it was dirty */
            if (bi->pagesInUse == 0 &&
                !bi->hasShrinkHeader &&
                bi->blockState == YAFFS_BLOCK_STATE_FULL) {
                  yaffs_BlockBecameDirty(dev, blk);
            }

      }

      if (blockIndex) {
            YFREE(blockIndex);
      }


      /* Ok, we've done all the scanning.
       * Fix up the hard link chains.
       * We should now have scanned all the objects, now it's time to add these
       * hardlinks.
       */

      yaffs_HardlinkFixup(dev,hardList);

      /* Handle the unlinked files. Since they were left in an unlinked state we should
       * just delete them.
       */
      {
            struct list_head *i;
            struct list_head *n;

            yaffs_Object *l;
            /* Soft delete all the unlinked files */
            list_for_each_safe(i, n,
                           &dev->unlinkedDir->variant.directoryVariant.
                           children) {
                  if (i) {
                        l = list_entry(i, yaffs_Object, siblings);
                        yaffs_DestroyObject(l);
                  }
            }
      }

      yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);

      if(alloc_failed){
            return YAFFS_FAIL;
      }

      T(YAFFS_TRACE_SCAN, (TSTR("yaffs_Scan ends" TENDSTR)));


      return YAFFS_OK;
}

static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in)
{
      __u8 *chunkData;
      yaffs_ObjectHeader *oh;
      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__);

            result = yaffs_ReadChunkWithTagsFromNAND(dev,in->chunkId,chunkData,&tags);
            oh = (yaffs_ObjectHeader *) chunkData;

            in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
            in->win_atime[0] = oh->win_atime[0];
            in->win_ctime[0] = oh->win_ctime[0];
            in->win_mtime[0] = oh->win_mtime[0];
            in->win_atime[1] = oh->win_atime[1];
            in->win_ctime[1] = oh->win_ctime[1];
            in->win_mtime[1] = oh->win_mtime[1];
#else
            in->yst_uid = oh->yst_uid;
            in->yst_gid = oh->yst_gid;
            in->yst_atime = oh->yst_atime;
            in->yst_mtime = oh->yst_mtime;
            in->yst_ctime = oh->yst_ctime;
            in->yst_rdev = oh->yst_rdev;

#endif
            yaffs_SetObjectName(in, oh->name);

            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__);
      }
}

static int yaffs_ScanBackwards(yaffs_Device * dev)
{
      yaffs_ExtendedTags tags;
      int blk;
      int blockIterator;
      int startIterator;
      int endIterator;
      int nBlocksToScan = 0;

      int chunk;
      int result;
      int c;
      int deleted;
      yaffs_BlockState state;
      yaffs_Object *hardList = NULL;
      yaffs_BlockInfo *bi;
      int sequenceNumber;
      yaffs_ObjectHeader *oh;
      yaffs_Object *in;
      yaffs_Object *parent;
      int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
      int itsUnlinked;
      __u8 *chunkData;

      int fileSize;
      int isShrink;
      int foundChunksInBlock;
      int equivalentObjectId;
      int alloc_failed = 0;


      yaffs_BlockIndex *blockIndex = NULL;
      int altBlockIndex = 0;

      if (!dev->isYaffs2) {
            T(YAFFS_TRACE_SCAN,
              (TSTR("yaffs_ScanBackwards is only for YAFFS2!" TENDSTR)));
            return YAFFS_FAIL;
      }

      T(YAFFS_TRACE_SCAN,
        (TSTR
         ("yaffs_ScanBackwards starts  intstartblk %d intendblk %d..."
          TENDSTR), dev->internalStartBlock, dev->internalEndBlock));


      dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;

      blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));

      if(!blockIndex) {
            blockIndex = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockIndex));
            altBlockIndex = 1;
      }

      if(!blockIndex) {
            T(YAFFS_TRACE_SCAN,
              (TSTR("yaffs_Scan() could not allocate block index!" TENDSTR)));
            return YAFFS_FAIL;
      }

      dev->blocksInCheckpoint = 0;

      chunkData = yaffs_GetTempBuffer(dev, __LINE__);

      /* Scan all the blocks to determine their state */
      for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
            bi = yaffs_GetBlockInfo(dev, blk);
            yaffs_ClearChunkBits(dev, blk);
            bi->pagesInUse = 0;
            bi->softDeletions = 0;

            yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);

            bi->blockState = state;
            bi->sequenceNumber = sequenceNumber;

            if(bi->sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA)
                  bi->blockState = state = YAFFS_BLOCK_STATE_CHECKPOINT;

            T(YAFFS_TRACE_SCAN_DEBUG,
              (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
               state, sequenceNumber));


            if(state == YAFFS_BLOCK_STATE_CHECKPOINT){
                  dev->blocksInCheckpoint++;

            } else if (state == YAFFS_BLOCK_STATE_DEAD) {
                  T(YAFFS_TRACE_BAD_BLOCKS,
                    (TSTR("block %d is bad" TENDSTR), blk));
            } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
                  T(YAFFS_TRACE_SCAN_DEBUG,
                    (TSTR("Block empty " TENDSTR)));
                  dev->nErasedBlocks++;
                  dev->nFreeChunks += dev->nChunksPerBlock;
            } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {

                  /* Determine the highest sequence number */
                  if (dev->isYaffs2 &&
                      sequenceNumber >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
                      sequenceNumber < YAFFS_HIGHEST_SEQUENCE_NUMBER) {

                        blockIndex[nBlocksToScan].seq = sequenceNumber;
                        blockIndex[nBlocksToScan].block = blk;

                        nBlocksToScan++;

                        if (sequenceNumber >= dev->sequenceNumber) {
                              dev->sequenceNumber = sequenceNumber;
                        }
                  } else if (dev->isYaffs2) {
                        /* TODO: Nasty sequence number! */
                        T(YAFFS_TRACE_SCAN,
                          (TSTR
                           ("Block scanning block %d has bad sequence number %d"
                            TENDSTR), blk, sequenceNumber));

                  }
            }
      }

      T(YAFFS_TRACE_SCAN,
      (TSTR("%d blocks to be sorted..." TENDSTR), nBlocksToScan));



      YYIELD();

      /* Sort the blocks */
#ifndef CONFIG_YAFFS_USE_OWN_SORT
      {
            /* Use qsort now. */
            yaffs_qsort(blockIndex, nBlocksToScan, sizeof(yaffs_BlockIndex), ybicmp);
      }
#else
      {
            /* Dungy old bubble sort... */

            yaffs_BlockIndex temp;
            int i;
            int j;

            for (i = 0; i < nBlocksToScan; i++)
                  for (j = i + 1; j < nBlocksToScan; j++)
                        if (blockIndex[i].seq > blockIndex[j].seq) {
                              temp = blockIndex[j];
                              blockIndex[j] = blockIndex[i];
                              blockIndex[i] = temp;
                        }
      }
#endif

      YYIELD();

      T(YAFFS_TRACE_SCAN, (TSTR("...done" TENDSTR)));

      /* Now scan the blocks looking at the data. */
      startIterator = 0;
      endIterator = nBlocksToScan - 1;
      T(YAFFS_TRACE_SCAN_DEBUG,
        (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));

      /* For each block.... backwards */
      for (blockIterator = endIterator; !alloc_failed && blockIterator >= startIterator;
           blockIterator--) {
            /* Cooperative multitasking! This loop can run for so
               long that watchdog timers expire. */
            YYIELD();

            /* get the block to scan in the correct order */
            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;
                 !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,
                                          &tags);

                  /* Let's have a good look at this chunk... */

                  if (!tags.chunkUsed) {
                        /* An unassigned chunk in the block.
                         * If there are used chunks after this one, then
                         * it is a chunk that was skipped due to failing the erased
                         * check. Just skip it so that it can be deleted.
                         * But, more typically, We get here when this is an unallocated
                         * chunk and his means that either the block is empty or
                         * this is the one being allocated from
                         */

                        if(foundChunksInBlock)
                        {
                              /* This is a chunk that was skipped due to failing the erased check */

                        } else if (c == 0) {
                              /* We're looking at the first chunk in the block so the block is unused */
                              state = YAFFS_BLOCK_STATE_EMPTY;
                              dev->nErasedBlocks++;
                        } else {
                              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));
                                    }

                              }

                        }

                        dev->nFreeChunks++;

                  } else if (tags.chunkId > 0) {
                        /* chunkId > 0 so it is a data chunk... */
                        unsigned int endpos;
                        __u32 chunkBase =
                            (tags.chunkId - 1) * dev->nDataBytesPerChunk;

                        foundChunksInBlock = 1;


                        yaffs_SetChunkBit(dev, blk, c);
                        bi->pagesInUse++;

                        in = yaffs_FindOrCreateObjectByNumber(dev,
                                                      tags.
                                                      objectId,
                                                      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 */
                              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.
                               */
                              endpos =
                                  (tags.chunkId -
                                   1) * dev->nDataBytesPerChunk +
                                  tags.byteCount;

                              if (!in->valid && /* have not got an object header yet */
                                  in->variant.fileVariant.
                                  scannedFileSize < endpos) {
                                    in->variant.fileVariant.
                                        scannedFileSize = endpos;
                                    in->variant.fileVariant.
                                        fileSize =
                                        in->variant.fileVariant.
                                        scannedFileSize;
                              }

                        } else if(in) {
                              /* This chunk has been invalidated by a resize, so delete */
                              yaffs_DeleteChunk(dev, chunk, 1, __LINE__);

                        }
                  } else {
                        /* chunkId == 0, so it is an ObjectHeader.
                         * Thus, we read in the object header and make the object
                         */
                        foundChunksInBlock = 1;

                        yaffs_SetChunkBit(dev, blk, c);
                        bi->pagesInUse++;

                        oh = NULL;
                        in = NULL;

                        if (tags.extraHeaderInfoAvailable) {
                              in = yaffs_FindOrCreateObjectByNumber
                                  (dev, tags.objectId,
                                   tags.extraObjectType);
                        }

                        if (!in ||
#ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
                            !in->valid ||
#endif
                            tags.extraShadows ||
                            (!in->valid &&
                            (tags.objectId == YAFFS_OBJECTID_ROOT ||
                             tags.objectId == YAFFS_OBJECTID_LOSTNFOUND))
                            ) {

                              /* If we don't have  valid info then we need to read the chunk
                               * TODO In future we can probably defer reading the chunk and
                               * living with invalid data until needed.
                               */

                              result = yaffs_ReadChunkWithTagsFromNAND(dev,
                                                      chunk,
                                                      chunkData,
                                                      NULL);

                              oh = (yaffs_ObjectHeader *) chunkData;

                              if (!in)
                                    in = yaffs_FindOrCreateObjectByNumber(dev, tags.objectId, oh->type);

                        }

                        if (!in) {
                              /* TODO Hoosterman we have a problem! */
                              T(YAFFS_TRACE_ERROR,
                                (TSTR
                                 ("yaffs tragedy: Could not make object for object  %d  "
                                  "at chunk %d during scan"
                                  TENDSTR), tags.objectId, chunk));

                        }

                        if (in->valid) {
                              /* We have already filled this one.
                               * We have a duplicate that will be discarded, but
                               * we first have to suck out resize info if it is a file.
                               */

                              if ((in->variantType == YAFFS_OBJECT_TYPE_FILE) &&
                                   ((oh &&
                                     oh-> type == YAFFS_OBJECT_TYPE_FILE)||
                                    (tags.extraHeaderInfoAvailable  &&
                                     tags.extraObjectType == YAFFS_OBJECT_TYPE_FILE))
                                  ) {
                                    __u32 thisSize =
                                        (oh) ? oh->fileSize : tags.
                                        extraFileLength;
                                    __u32 parentObjectId =
                                        (oh) ? oh->
                                        parentObjectId : tags.
                                        extraParentObjectId;
                                    unsigned isShrink =
                                        (oh) ? oh->isShrink : tags.
                                        extraIsShrinkHeader;

                                    /* If it is deleted (unlinked at start also means deleted)
                                     * we treat the file size as being zeroed at this point.
                                     */
                                    if (parentObjectId ==
                                        YAFFS_OBJECTID_DELETED
                                        || parentObjectId ==
                                        YAFFS_OBJECTID_UNLINKED) {
                                          thisSize = 0;
                                          isShrink = 1;
                                    }

                                    if (isShrink &&
                                        in->variant.fileVariant.
                                        shrinkSize > thisSize) {
                                          in->variant.fileVariant.
                                              shrinkSize =
                                              thisSize;
                                    }

                                    if (isShrink) {
                                          bi->hasShrinkHeader = 1;
                                    }

                              }
                              /* Use existing - destroy this one. */
                              yaffs_DeleteChunk(dev, chunk, 1, __LINE__);

                        }

                        if (!in->valid &&
                            (tags.objectId == YAFFS_OBJECTID_ROOT ||
                             tags.objectId ==
                             YAFFS_OBJECTID_LOSTNFOUND)) {
                              /* We only load some info, don't fiddle with directory structure */
                              in->valid = 1;

                              if(oh) {
                                    in->variantType = oh->type;

                                    in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
                                    in->win_atime[0] = oh->win_atime[0];
                                    in->win_ctime[0] = oh->win_ctime[0];
                                    in->win_mtime[0] = oh->win_mtime[0];
                                    in->win_atime[1] = oh->win_atime[1];
                                    in->win_ctime[1] = oh->win_ctime[1];
                                    in->win_mtime[1] = oh->win_mtime[1];
#else
                                    in->yst_uid = oh->yst_uid;
                                    in->yst_gid = oh->yst_gid;
                                    in->yst_atime = oh->yst_atime;
                                    in->yst_mtime = oh->yst_mtime;
                                    in->yst_ctime = oh->yst_ctime;
                                    in->yst_rdev = oh->yst_rdev;

#endif
                              } else {
                                    in->variantType = tags.extraObjectType;
                                    in->lazyLoaded = 1;
                              }

                              in->chunkId = chunk;

                        } else if (!in->valid) {
                              /* we need to load this info */

                              in->valid = 1;
                              in->chunkId = chunk;

                              if(oh) {
                                    in->variantType = oh->type;

                                    in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
                                    in->win_atime[0] = oh->win_atime[0];
                                    in->win_ctime[0] = oh->win_ctime[0];
                                    in->win_mtime[0] = oh->win_mtime[0];
                                    in->win_atime[1] = oh->win_atime[1];
                                    in->win_ctime[1] = oh->win_ctime[1];
                                    in->win_mtime[1] = oh->win_mtime[1];
#else
                                    in->yst_uid = oh->yst_uid;
                                    in->yst_gid = oh->yst_gid;
                                    in->yst_atime = oh->yst_atime;
                                    in->yst_mtime = oh->yst_mtime;
                                    in->yst_ctime = oh->yst_ctime;
                                    in->yst_rdev = oh->yst_rdev;
#endif

                                    if (oh->shadowsObject > 0)
                                          yaffs_HandleShadowedObject(dev,
                                                         oh->
                                                         shadowsObject,
                                                         1);


                                    yaffs_SetObjectName(in, oh->name);
                                    parent =
                                        yaffs_FindOrCreateObjectByNumber
                                          (dev, oh->parentObjectId,
                                           YAFFS_OBJECT_TYPE_DIRECTORY);

                                     fileSize = oh->fileSize;
                                     isShrink = oh->isShrink;
                                     equivalentObjectId = oh->equivalentObjectId;

                              }
                              else {
                                    in->variantType = tags.extraObjectType;
                                    parent =
                                        yaffs_FindOrCreateObjectByNumber
                                          (dev, tags.extraParentObjectId,
                                           YAFFS_OBJECT_TYPE_DIRECTORY);
                                     fileSize = tags.extraFileLength;
                                     isShrink = tags.extraIsShrinkHeader;
                                     equivalentObjectId = tags.extraEquivalentObjectId;
                                    in->lazyLoaded = 1;

                              }
                              in->dirty = 0;

                              /* directory stuff...
                               * hook up to parent
                               */

                              if (parent->variantType ==
                                  YAFFS_OBJECT_TYPE_UNKNOWN) {
                                    /* Set up as a directory */
                                    parent->variantType =
                                        YAFFS_OBJECT_TYPE_DIRECTORY;
                                    INIT_LIST_HEAD(&parent->variant.
                                                 directoryVariant.
                                                 children);
                              } else if (parent->variantType !=
                                       YAFFS_OBJECT_TYPE_DIRECTORY)
                              {
                                    /* Hoosterman, another problem....
                                     * We're trying to use a non-directory as a directory
                                     */

                                    T(YAFFS_TRACE_ERROR,
                                      (TSTR
                                       ("yaffs tragedy: attempting to use non-directory as"
                                        " a directory in scan. Put in lost+found."
                                        TENDSTR)));
                                    parent = dev->lostNFoundDir;
                              }

                              yaffs_AddObjectToDirectory(parent, in);

                              itsUnlinked = (parent == dev->deletedDir) ||
                                          (parent == dev->unlinkedDir);

                              if (isShrink) {
                                    /* Mark the block as having a shrinkHeader */
                                    bi->hasShrinkHeader = 1;
                              }

                              /* Note re hardlinks.
                               * Since we might scan a hardlink before its equivalent object is scanned
                               * we put them all in a list.
                               * After scanning is complete, we should have all the objects, so we run
                               * through this list and fix up all the chains.
                               */

                              switch (in->variantType) {
                              case YAFFS_OBJECT_TYPE_UNKNOWN:
                                    /* Todo got a problem */
                                    break;
                              case YAFFS_OBJECT_TYPE_FILE:

                                    if (in->variant.fileVariant.
                                        scannedFileSize < fileSize) {
                                          /* This covers the case where the file size is greater
                                           * than where the data is
                                           * This will happen if the file is resized to be larger
                                           * than its current data extents.
                                           */
                                          in->variant.fileVariant.fileSize = fileSize;
                                          in->variant.fileVariant.scannedFileSize =
                                              in->variant.fileVariant.fileSize;
                                    }

                                    if (isShrink &&
                                        in->variant.fileVariant.shrinkSize > fileSize) {
                                          in->variant.fileVariant.shrinkSize = fileSize;
                                    }

                                    break;
                              case YAFFS_OBJECT_TYPE_HARDLINK:
                                    if(!itsUnlinked) {
                                      in->variant.hardLinkVariant.equivalentObjectId =
                                        equivalentObjectId;
                                      in->hardLinks.next =
                                        (struct list_head *) hardList;
                                      hardList = in;
                                    }
                                    break;
                              case YAFFS_OBJECT_TYPE_DIRECTORY:
                                    /* Do nothing */
                                    break;
                              case YAFFS_OBJECT_TYPE_SPECIAL:
                                    /* Do nothing */
                                    break;
                              case YAFFS_OBJECT_TYPE_SYMLINK:
                                    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. */
                  state = YAFFS_BLOCK_STATE_FULL;
            }

            bi->blockState = state;

            /* Now let's see if it was dirty */
            if (bi->pagesInUse == 0 &&
                !bi->hasShrinkHeader &&
                bi->blockState == YAFFS_BLOCK_STATE_FULL) {
                  yaffs_BlockBecameDirty(dev, blk);
            }

      }

      if (altBlockIndex)
            YFREE_ALT(blockIndex);
      else
            YFREE(blockIndex);

      /* Ok, we've done all the scanning.
       * Fix up the hard link chains.
       * We should now have scanned all the objects, now it's time to add these
       * hardlinks.
       */
      yaffs_HardlinkFixup(dev,hardList);


      /*
      *  Sort out state of unlinked and deleted objects.
      */
      {
            struct list_head *i;
            struct list_head *n;

            yaffs_Object *l;

            /* Soft delete all the unlinked files */
            list_for_each_safe(i, n,
                           &dev->unlinkedDir->variant.directoryVariant.
                           children) {
                  if (i) {
                        l = list_entry(i, yaffs_Object, siblings);
                        yaffs_DestroyObject(l);
                  }
            }

            /* Soft delete all the deletedDir files */
            list_for_each_safe(i, n,
                           &dev->deletedDir->variant.directoryVariant.
                           children) {
                  if (i) {
                        l = list_entry(i, yaffs_Object, siblings);
                        yaffs_DestroyObject(l);

                  }
            }
      }

      yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);

      if(alloc_failed){
            return YAFFS_FAIL;
      }

      T(YAFFS_TRACE_SCAN, (TSTR("yaffs_ScanBackwards ends" TENDSTR)));

      return YAFFS_OK;
}

/*------------------------------  Directory Functions ----------------------------- */

static void yaffs_RemoveObjectFromDirectory(yaffs_Object * obj)
{
      yaffs_Device *dev = obj->myDev;

      if(dev && dev->removeObjectCallback)
            dev->removeObjectCallback(obj);

      list_del_init(&obj->siblings);
      obj->parent = NULL;
}


static void yaffs_AddObjectToDirectory(yaffs_Object * directory,
                               yaffs_Object * obj)
{

      if (!directory) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: Trying to add an object to a null pointer directory"
                TENDSTR)));
            YBUG();
      }
      if (directory->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: Trying to add an object to a non-directory"
                TENDSTR)));
            YBUG();
      }

      if (obj->siblings.prev == NULL) {
            /* Not initialised */
            INIT_LIST_HEAD(&obj->siblings);

      } else if (!list_empty(&obj->siblings)) {
            /* If it is holed up somewhere else, un hook it */
            yaffs_RemoveObjectFromDirectory(obj);
      }
      /* Now add it */
      list_add(&obj->siblings, &directory->variant.directoryVariant.children);
      obj->parent = directory;

      if (directory == obj->myDev->unlinkedDir
          || directory == obj->myDev->deletedDir) {
            obj->unlinked = 1;
            obj->myDev->nUnlinkedFiles++;
            obj->renameAllowed = 0;
      }
}

yaffs_Object *yaffs_FindObjectByName(yaffs_Object * directory,
                             const YCHAR * name)
{
      int sum;

      struct list_head *i;
      YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];

      yaffs_Object *l;

      if (!name) {
            return NULL;
      }

      if (!directory) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: yaffs_FindObjectByName: null pointer directory"
                TENDSTR)));
            YBUG();
      }
      if (directory->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: yaffs_FindObjectByName: non-directory" TENDSTR)));
            YBUG();
      }

      sum = yaffs_CalcNameSum(name);

      list_for_each(i, &directory->variant.directoryVariant.children) {
            if (i) {
                  l = list_entry(i, yaffs_Object, siblings);

                  yaffs_CheckObjectDetailsLoaded(l);

                  /* Special case for lost-n-found */
                  if (l->objectId == YAFFS_OBJECTID_LOSTNFOUND) {
                        if (yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME) == 0) {
                              return l;
                        }
                  } else if (yaffs_SumCompare(l->sum, sum) || l->chunkId <= 0)
                  {
                        /* LostnFound cunk called Objxxx
                         * Do a real check
                         */
                        yaffs_GetObjectName(l, buffer,
                                        YAFFS_MAX_NAME_LENGTH);
                        if (yaffs_strncmp(name, buffer,YAFFS_MAX_NAME_LENGTH) == 0) {
                              return l;
                        }

                  }
            }
      }

      return NULL;
}


#if 0
int yaffs_ApplyToDirectoryChildren(yaffs_Object * theDir,
                           int (*fn) (yaffs_Object *))
{
      struct list_head *i;
      yaffs_Object *l;

      if (!theDir) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: yaffs_FindObjectByName: null pointer directory"
                TENDSTR)));
            YBUG();
      }
      if (theDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("tragedy: yaffs_FindObjectByName: non-directory" TENDSTR)));
            YBUG();
      }

      list_for_each(i, &theDir->variant.directoryVariant.children) {
            if (i) {
                  l = list_entry(i, yaffs_Object, siblings);
                  if (l && !fn(l)) {
                        return YAFFS_FAIL;
                  }
            }
      }

      return YAFFS_OK;

}
#endif

/* GetEquivalentObject dereferences any hard links to get to the
 * actual object.
 */

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;

}

int yaffs_GetObjectName(yaffs_Object * obj, YCHAR * name, int buffSize)
{
      memset(name, 0, buffSize * sizeof(YCHAR));

      yaffs_CheckObjectDetailsLoaded(obj);

      if (obj->objectId == YAFFS_OBJECTID_LOSTNFOUND) {
            yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffSize - 1);
      } else if (obj->chunkId <= 0) {
            YCHAR locName[20];
            /* make up a name */
            yaffs_sprintf(locName, _Y("%s%d"), YAFFS_LOSTNFOUND_PREFIX,
                        obj->objectId);
            yaffs_strncpy(name, locName, buffSize - 1);

      }
#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
      else if (obj->shortName[0]) {
            yaffs_strcpy(name, obj->shortName);
      }
#endif
      else {
            int result;
            __u8 *buffer = yaffs_GetTempBuffer(obj->myDev, __LINE__);

            yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *) buffer;

            memset(buffer, 0, obj->myDev->nDataBytesPerChunk);

            if (obj->chunkId >= 0) {
                  result = yaffs_ReadChunkWithTagsFromNAND(obj->myDev,
                                          obj->chunkId, buffer,
                                          NULL);
            }
            yaffs_strncpy(name, oh->name, buffSize - 1);

            yaffs_ReleaseTempBuffer(obj->myDev, buffer, __LINE__);
      }

      return yaffs_strlen(name);
}

int yaffs_GetObjectFileLength(yaffs_Object * obj)
{

      /* Dereference any hard linking */
      obj = yaffs_GetEquivalentObject(obj);

      if (obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
            return obj->variant.fileVariant.fileSize;
      }
      if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK) {
            return yaffs_strlen(obj->variant.symLinkVariant.alias);
      } else {
            /* Only a directory should drop through to here */
            return obj->myDev->nDataBytesPerChunk;
      }
}

int yaffs_GetObjectLinkCount(yaffs_Object * obj)
{
      int count = 0;
      struct list_head *i;

      if (!obj->unlinked) {
            count++;    /* the object itself */
      }
      list_for_each(i, &obj->hardLinks) {
            count++;    /* add the hard links; */
      }
      return count;

}

int yaffs_GetObjectInode(yaffs_Object * obj)
{
      obj = yaffs_GetEquivalentObject(obj);

      return obj->objectId;
}

unsigned yaffs_GetObjectType(yaffs_Object * obj)
{
      obj = yaffs_GetEquivalentObject(obj);

      switch (obj->variantType) {
      case YAFFS_OBJECT_TYPE_FILE:
            return DT_REG;
            break;
      case YAFFS_OBJECT_TYPE_DIRECTORY:
            return DT_DIR;
            break;
      case YAFFS_OBJECT_TYPE_SYMLINK:
            return DT_LNK;
            break;
      case YAFFS_OBJECT_TYPE_HARDLINK:
            return DT_REG;
            break;
      case YAFFS_OBJECT_TYPE_SPECIAL:
            if (S_ISFIFO(obj->yst_mode))
                  return DT_FIFO;
            if (S_ISCHR(obj->yst_mode))
                  return DT_CHR;
            if (S_ISBLK(obj->yst_mode))
                  return DT_BLK;
            if (S_ISSOCK(obj->yst_mode))
                  return DT_SOCK;
      default:
            return DT_REG;
            break;
      }
}

YCHAR *yaffs_GetSymlinkAlias(yaffs_Object * obj)
{
      obj = yaffs_GetEquivalentObject(obj);
      if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK) {
            return yaffs_CloneString(obj->variant.symLinkVariant.alias);
      } else {
            return yaffs_CloneString(_Y(""));
      }
}

#ifndef CONFIG_YAFFS_WINCE

int yaffs_SetAttributes(yaffs_Object * obj, struct iattr *attr)
{
      unsigned int valid = attr->ia_valid;

      if (valid & ATTR_MODE)
            obj->yst_mode = attr->ia_mode;
      if (valid & ATTR_UID)
            obj->yst_uid = attr->ia_uid;
      if (valid & ATTR_GID)
            obj->yst_gid = attr->ia_gid;

      if (valid & ATTR_ATIME)
            obj->yst_atime = Y_TIME_CONVERT(attr->ia_atime);
      if (valid & ATTR_CTIME)
            obj->yst_ctime = Y_TIME_CONVERT(attr->ia_ctime);
      if (valid & ATTR_MTIME)
            obj->yst_mtime = Y_TIME_CONVERT(attr->ia_mtime);

      if (valid & ATTR_SIZE)
            yaffs_ResizeFile(obj, attr->ia_size);

      yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0);

      return YAFFS_OK;

}
int yaffs_GetAttributes(yaffs_Object * obj, struct iattr *attr)
{
      unsigned int valid = 0;

      attr->ia_mode = obj->yst_mode;
      valid |= ATTR_MODE;
      attr->ia_uid = obj->yst_uid;
      valid |= ATTR_UID;
      attr->ia_gid = obj->yst_gid;
      valid |= ATTR_GID;

      Y_TIME_CONVERT(attr->ia_atime) = obj->yst_atime;
      valid |= ATTR_ATIME;
      Y_TIME_CONVERT(attr->ia_ctime) = obj->yst_ctime;
      valid |= ATTR_CTIME;
      Y_TIME_CONVERT(attr->ia_mtime) = obj->yst_mtime;
      valid |= ATTR_MTIME;

      attr->ia_size = yaffs_GetFileSize(obj);
      valid |= ATTR_SIZE;

      attr->ia_valid = valid;

      return YAFFS_OK;

}

#endif

#if 0
int yaffs_DumpObject(yaffs_Object * obj)
{
      YCHAR name[257];

      yaffs_GetObjectName(obj, name, 256);

      T(YAFFS_TRACE_ALWAYS,
        (TSTR
         ("Object %d, inode %d \"%s\"\n dirty %d valid %d serial %d sum %d"
          " chunk %d type %d size %d\n"
          TENDSTR), obj->objectId, yaffs_GetObjectInode(obj), name,
         obj->dirty, obj->valid, obj->serial, obj->sum, obj->chunkId,
         yaffs_GetObjectType(obj), yaffs_GetObjectFileLength(obj)));

      return YAFFS_OK;
}
#endif

/*---------------------------- Initialisation code -------------------------------------- */

static int yaffs_CheckDevFunctions(const yaffs_Device * dev)
{

      /* Common functions, gotta have */
      if (!dev->eraseBlockInNAND || !dev->initialiseNAND)
            return 0;

#ifdef CONFIG_YAFFS_YAFFS2

      /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
      if (dev->writeChunkWithTagsToNAND &&
          dev->readChunkWithTagsFromNAND &&
          !dev->writeChunkToNAND &&
          !dev->readChunkFromNAND &&
          dev->markNANDBlockBad && dev->queryNANDBlock)
            return 1;
#endif

      /* Can use the "spare" style interface for yaffs1 */
      if (!dev->isYaffs2 &&
          !dev->writeChunkWithTagsToNAND &&
          !dev->readChunkWithTagsFromNAND &&
          dev->writeChunkToNAND &&
          dev->readChunkFromNAND &&
          !dev->markNANDBlockBad && !dev->queryNANDBlock)
            return 1;

      return 0;         /* bad */
}


static int yaffs_CreateInitialDirectories(yaffs_Device *dev)
{
      /* Initialise the unlinked, deleted, root and lost and found directories */

      dev->lostNFoundDir = dev->rootDir =  NULL;
      dev->unlinkedDir = dev->deletedDir = NULL;

      dev->unlinkedDir =
          yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);

      dev->deletedDir =
          yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);

      dev->rootDir =
          yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_ROOT,
                              YAFFS_ROOT_MODE | S_IFDIR);
      dev->lostNFoundDir =
          yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_LOSTNFOUND,
                              YAFFS_LOSTNFOUND_MODE | S_IFDIR);

      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;

      T(YAFFS_TRACE_TRACING, (TSTR("yaffs: yaffs_GutsInitialise()" TENDSTR)));

      /* Check stuff that must be set */

      if (!dev) {
            T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Need a device" TENDSTR)));
            return YAFFS_FAIL;
      }

      dev->internalStartBlock = dev->startBlock;
      dev->internalEndBlock = dev->endBlock;
      dev->blockOffset = 0;
      dev->chunkOffset = 0;
      dev->nFreeChunks = 0;

      if (dev->startBlock == 0) {
            dev->internalStartBlock = dev->startBlock + 1;
            dev->internalEndBlock = dev->endBlock + 1;
            dev->blockOffset = 1;
            dev->chunkOffset = dev->nChunksPerBlock;
      }

      /* Check geometry parameters. */

      if ((dev->isYaffs2 && dev->nDataBytesPerChunk < 1024) ||
          (!dev->isYaffs2 && dev->nDataBytesPerChunk != 512) ||
           dev->nChunksPerBlock < 2 ||
           dev->nReservedBlocks < 2 ||
           dev->internalStartBlock <= 0 ||
           dev->internalEndBlock <= 0 ||
           dev->internalEndBlock <= (dev->internalStartBlock + dev->nReservedBlocks + 2)  // otherwise it is too small
          ) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("yaffs: NAND geometry problems: chunk size %d, type is yaffs%s "
                TENDSTR), dev->nDataBytesPerChunk, dev->isYaffs2 ? "2" : ""));
            return YAFFS_FAIL;
      }

      if (yaffs_InitialiseNAND(dev) != YAFFS_OK) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR("yaffs: InitialiseNAND failed" TENDSTR)));
            return YAFFS_FAIL;
      }

      /* Got the right mix of functions? */
      if (!yaffs_CheckDevFunctions(dev)) {
            /* Function missing */
            T(YAFFS_TRACE_ALWAYS,
              (TSTR
               ("yaffs: device function(s) missing or wrong\n" TENDSTR)));

            return YAFFS_FAIL;
      }

      /* This is really a compilation check. */
      if (!yaffs_CheckStructures()) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR("yaffs_CheckStructures failed\n" TENDSTR)));
            return YAFFS_FAIL;
      }

      if (dev->isMounted) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR("yaffs: device already mounted\n" TENDSTR)));
            return YAFFS_FAIL;
      }

      /* Finished with most checks. One or two more checks happen later on too. */

      dev->isMounted = 1;



      /* OK now calculate a few things for the device */

      /*
       *  Calculate all the chunk size manipulation numbers:
       */
       /* Start off assuming it is a power of 2 */
       dev->chunkShift = ShiftDiv(dev->nDataBytesPerChunk);
       dev->chunkMask = (1<<dev->chunkShift) - 1;

       if(dev->nDataBytesPerChunk == (dev->chunkMask + 1)){
            /* Yes it is a power of 2, disable crumbs */
            dev->crumbMask = 0;
            dev->crumbShift = 0;
            dev->crumbsPerChunk = 0;
       } else {
            /* Not a power of 2, use crumbs instead */
            dev->crumbShift = ShiftDiv(sizeof(yaffs_PackedTags2TagsPart));
            dev->crumbMask = (1<<dev->crumbShift)-1;
            dev->crumbsPerChunk = dev->nDataBytesPerChunk/(1 << dev->crumbShift);
            dev->chunkShift = 0;
            dev->chunkMask = 0;
      }


      /*
       * Calculate chunkGroupBits.
       * We need to find the next power of 2 > than internalEndBlock
       */

      x = dev->nChunksPerBlock * (dev->internalEndBlock + 1);

      bits = ShiftsGE(x);

      /* Set up tnode width if wide tnodes are enabled. */
      if(!dev->wideTnodesDisabled){
            /* bits must be even so that we end up with 32-bit words */
            if(bits & 1)
                  bits++;
            if(bits < 16)
                  dev->tnodeWidth = 16;
            else
                  dev->tnodeWidth = bits;
      }
      else
            dev->tnodeWidth = 16;

      dev->tnodeMask = (1<<dev->tnodeWidth)-1;

      /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
       * so if the bitwidth of the
       * chunk range we're using is greater than 16 we need
       * to figure out chunk shift and chunkGroupSize
       */

      if (bits <= dev->tnodeWidth)
            dev->chunkGroupBits = 0;
      else
            dev->chunkGroupBits = bits - dev->tnodeWidth;


      dev->chunkGroupSize = 1 << dev->chunkGroupBits;

      if (dev->nChunksPerBlock < dev->chunkGroupSize) {
            /* We have a problem because the soft delete won't work if
             * the chunk group size > chunks per block.
             * This can be remedied by using larger "virtual blocks".
             */
            T(YAFFS_TRACE_ALWAYS,
              (TSTR("yaffs: chunk group too large\n" TENDSTR)));

            return YAFFS_FAIL;
      }

      /* OK, we've finished verifying the device, lets continue with initialisation */

      /* More device initialisation */
      dev->garbageCollections = 0;
      dev->passiveGarbageCollections = 0;
      dev->currentDirtyChecker = 0;
      dev->bufferedBlock = -1;
      dev->doingBufferedBlockRewrite = 0;
      dev->nDeletedFiles = 0;
      dev->nBackgroundDeletions = 0;
      dev->nUnlinkedFiles = 0;
      dev->eccFixed = 0;
      dev->eccUnfixed = 0;
      dev->tagsEccFixed = 0;
      dev->tagsEccUnfixed = 0;
      dev->nErasureFailures = 0;
      dev->nErasedBlocks = 0;
      dev->isDoingGC = 0;
      dev->hasPendingPrioritisedGCs = 1; /* Assume the worst for now, will get fixed on first GC */

      /* Initialise temporary buffers and caches. */
      if(!yaffs_InitialiseTempBuffers(dev))
            init_failed = 1;

      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;
            }

            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 = buf = YMALLOC_DMA(dev->nDataBytesPerChunk);
            }
            if(!buf)
                  init_failed = 1;

            dev->srLastUse = 0;
      }

      dev->cacheHits = 0;

      if(!init_failed){
            dev->gcCleanupList = YMALLOC(dev->nChunksPerBlock * sizeof(__u32));
            if(!dev->gcCleanupList)
                  init_failed = 1;
      }

      if (dev->isYaffs2) {
            dev->useHeaderFileSize = 1;
      }
      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){
            /* 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);


                        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;
      dev->nPageWrites = 0;
      dev->nBlockErasures = 0;
      dev->nGCCopies = 0;
      dev->nRetriedWrites = 0;

      dev->nRetiredBlocks = 0;

      yaffs_VerifyFreeChunks(dev);
      yaffs_VerifyBlocks(dev);


      T(YAFFS_TRACE_TRACING,
        (TSTR("yaffs: yaffs_GutsInitialise() done.\n" TENDSTR)));
      return YAFFS_OK;

}

void yaffs_Deinitialise(yaffs_Device * dev)
{
      if (dev->isMounted) {
            int i;

            yaffs_DeinitialiseBlocks(dev);
            yaffs_DeinitialiseTnodes(dev);
            yaffs_DeinitialiseObjects(dev);
            if (dev->nShortOpCaches > 0 &&
                dev->srCache) {

                  for (i = 0; i < dev->nShortOpCaches; i++) {
                        if(dev->srCache[i].data)
                              YFREE(dev->srCache[i].data);
                        dev->srCache[i].data = NULL;
                  }

                  YFREE(dev->srCache);
                  dev->srCache = NULL;
            }

            YFREE(dev->gcCleanupList);

            for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
                  YFREE(dev->tempBuffer[i].buffer);
            }

            dev->isMounted = 0;
      }

}

static int yaffs_CountFreeChunks(yaffs_Device * dev)
{
      int nFree;
      int b;

      yaffs_BlockInfo *blk;

      for (nFree = 0, b = dev->internalStartBlock; b <= dev->internalEndBlock;
           b++) {
            blk = yaffs_GetBlockInfo(dev, b);

            switch (blk->blockState) {
            case YAFFS_BLOCK_STATE_EMPTY:
            case YAFFS_BLOCK_STATE_ALLOCATING:
            case YAFFS_BLOCK_STATE_COLLECTING:
            case YAFFS_BLOCK_STATE_FULL:
                  nFree +=
                      (dev->nChunksPerBlock - blk->pagesInUse +
                       blk->softDeletions);
                  break;
            default:
                  break;
            }

      }

      return nFree;
}

int yaffs_GetNumberOfFreeChunks(yaffs_Device * dev)
{
      /* This is what we report to the outside world */

      int nFree;
      int nDirtyCacheChunks;
      int blocksForCheckpoint;

#if 1
      nFree = dev->nFreeChunks;
#else
      nFree = yaffs_CountFreeChunks(dev);
#endif

      nFree += dev->nDeletedFiles;

      /* Now count the number of dirty chunks in the cache and subtract those */

      {
            int i;
            for (nDirtyCacheChunks = 0, i = 0; i < dev->nShortOpCaches; i++) {
                  if (dev->srCache[i].dirty)
                        nDirtyCacheChunks++;
            }
      }

      nFree -= nDirtyCacheChunks;

      nFree -= ((dev->nReservedBlocks + 1) * dev->nChunksPerBlock);

      /* Now we figure out how much to reserve for the checkpoint and report that... */
      blocksForCheckpoint = dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint;
      if(blocksForCheckpoint < 0)
            blocksForCheckpoint = 0;

      nFree -= (blocksForCheckpoint * dev->nChunksPerBlock);

      if (nFree < 0)
            nFree = 0;

      return nFree;

}

static int yaffs_freeVerificationFailures;

static void yaffs_VerifyFreeChunks(yaffs_Device * dev)
{
      int counted;
      int difference;

      if(yaffs_SkipVerification(dev))
            return;

      counted = yaffs_CountFreeChunks(dev);

      difference = dev->nFreeChunks - counted;

      if (difference) {
            T(YAFFS_TRACE_ALWAYS,
              (TSTR("Freechunks verification failure %d %d %d" TENDSTR),
               dev->nFreeChunks, counted, difference));
            yaffs_freeVerificationFailures++;
      }
}

/*---------------------------------------- YAFFS test code ----------------------*/

#define yaffs_CheckStruct(structure,syze, name) \
         if(sizeof(structure) != syze) \
             { \
             T(YAFFS_TRACE_ALWAYS,(TSTR("%s should be %d but is %d\n" TENDSTR),\
             name,syze,sizeof(structure))); \
             return YAFFS_FAIL; \
            }

static int yaffs_CheckStructures(void)
{
/*      yaffs_CheckStruct(yaffs_Tags,8,"yaffs_Tags") */
/*      yaffs_CheckStruct(yaffs_TagsUnion,8,"yaffs_TagsUnion") */
/*      yaffs_CheckStruct(yaffs_Spare,16,"yaffs_Spare") */
#ifndef CONFIG_YAFFS_TNODE_LIST_DEBUG
      yaffs_CheckStruct(yaffs_Tnode, 2 * YAFFS_NTNODES_LEVEL0, "yaffs_Tnode")
#endif
          yaffs_CheckStruct(yaffs_ObjectHeader, 512, "yaffs_ObjectHeader")

          return YAFFS_OK;
}

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