Some improvements to garbage collection and st_xxx to yst_xxx changes
[yaffs2.git] / yaffs_guts.c
1
2 /*
3  * YAFFS: Yet another FFS. A NAND-flash specific file system. 
4  *
5  * Copyright (C) 2002 Aleph One Ltd.
6  *   for Toby Churchill Ltd and Brightstar Engineering
7  *
8  * Created by Charles Manning <charles@aleph1.co.uk>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  */
15  //yaffs_guts.c
16
17 const char *yaffs_guts_c_version="$Id: yaffs_guts.c,v 1.9 2005-07-18 23:16:04 charles Exp $";
18
19 #include "yportenv.h"
20
21 #include "yaffsinterface.h"
22 #include "yaffs_guts.h"
23 #include "yaffs_tagsvalidity.h"
24
25
26 #include "yaffs_tagscompat.h"
27
28 #ifdef CONFIG_YAFFS_WINCE
29 void yfsd_LockYAFFS(BOOL fsLockOnly);
30 void yfsd_UnlockYAFFS(BOOL fsLockOnly);
31 #endif
32
33 #define YAFFS_PASSIVE_GC_CHUNKS 2
34
35 #if 0
36 // Use Steven Hill's ECC struff instead
37 // External functions for ECC on data
38 void nand_calculate_ecc (const u_char *dat, u_char *ecc_code);
39 int nand_correct_data (u_char *dat, u_char *read_ecc, u_char *calc_ecc);
40 #define yaffs_ECCCalculate(data,ecc) nand_calculate_ecc(data,ecc)
41 #define yaffs_ECCCorrect(data,read_ecc,calc_ecc) nand_correct_ecc(data,read_ecc,calc_ecc)
42 #else
43 #include "yaffs_ecc.h"
44 #endif
45
46 #if 0
47 // countBits is a quick way of counting the number of bits in a byte.
48 // ie. countBits[n] holds the number of 1 bits in a byte with the value n.
49
50 static const char yaffs_countBitsTable[256] =
51 {
52 0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,
53 1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
54 1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
55 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
56 1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
57 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
58 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
59 3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
60 1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
61 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
62 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
63 3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
64 2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
65 3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
66 3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
67 4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8
68 };
69
70 static int yaffs_CountBits(__u8 x)
71 {
72         int retVal;
73         retVal = yaffs_countBitsTable[x];
74         return retVal;
75 }
76
77 #endif
78
79
80 #if 0
81 // Stuff using yea olde tags
82 static void yaffs_LoadTagsIntoSpare(yaffs_Spare *sparePtr, yaffs_Tags *tagsPtr);
83 static void yaffs_GetTagsFromSpare(yaffs_Device *dev, yaffs_Spare *sparePtr,yaffs_Tags *tagsPtr);
84
85 static int yaffs_ReadChunkTagsFromNAND(yaffs_Device *dev,int chunkInNAND, yaffs_Tags *tags, int *chunkDeleted);
86 static int yaffs_TagsMatch(const yaffs_Tags *tags, int objectId, int chunkInObject, int chunkDeleted);
87 #else
88 #endif
89
90 // NAND access
91
92
93 static Y_INLINE int yaffs_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *buffer, yaffs_ExtendedTags *tags);
94 static Y_INLINE int yaffs_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND, const __u8 *data, yaffs_ExtendedTags *tags);
95 static Y_INLINE int yaffs_MarkBlockBad(yaffs_Device *dev, int blockNo);
96 static Y_INLINE int yaffs_QueryInitialBlockState(yaffs_Device *dev,int blockNo, yaffs_BlockState *state,unsigned *sequenceNumber);
97 // Local prototypes
98 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev, const __u8 *buffer, yaffs_ExtendedTags *tags, int useReserve);
99 #if 0
100 static int yaffs_CheckObjectHashSanity(yaffs_Device *dev);
101 #endif
102 static int yaffs_PutChunkIntoFile(yaffs_Object *in,int chunkInInode, int chunkInNAND, int inScan);
103
104 static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev,int number,yaffs_ObjectType type);
105 static void yaffs_AddObjectToDirectory(yaffs_Object *directory, yaffs_Object *obj);
106 static int yaffs_UpdateObjectHeader(yaffs_Object *in,const YCHAR *name, int force,int isShrink);
107 static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
108 static int yaffs_CheckStructures(void);
109 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level, int chunkOffset,int *limit);
110 static int yaffs_DoGenericObjectDeletion(yaffs_Object *in);
111
112 static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device *dev,int blockNo);
113
114 static __u8 *yaffs_GetTempBuffer(yaffs_Device *dev,int lineNo);
115 static void yaffs_ReleaseTempBuffer(yaffs_Device *dev, __u8 *buffer, int lineNo);
116
117
118 // Robustification (if it ever comes about...)
119 static void yaffs_RetireBlock(yaffs_Device *dev,int blockInNAND);
120 #if 0
121 static void yaffs_HandleReadDataError(yaffs_Device *dev,int chunkInNAND);
122 #endif
123 static void yaffs_HandleWriteChunkError(yaffs_Device *dev,int chunkInNAND);
124 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags);
125 static void yaffs_HandleUpdateChunk(yaffs_Device *dev,int chunkInNAND,  const yaffs_ExtendedTags *tags);
126
127 static int  yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,int chunkInNAND);
128
129 static int yaffs_UnlinkWorker(yaffs_Object *obj);
130 static void yaffs_DestroyObject(yaffs_Object *obj);
131
132 #if 0
133 static int yaffs_VerifyCompare(const __u8 *d0, const __u8 * d1, const yaffs_Spare *s0, const yaffs_Spare *s1,int dataSize);
134 #endif
135
136 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId, int chunkInObject);
137
138
139 loff_t yaffs_GetFileSize(yaffs_Object *obj);
140
141
142 static int yaffs_AllocateChunk(yaffs_Device *dev,int useReserve);
143
144 static void yaffs_VerifyFreeChunks(yaffs_Device *dev);
145
146 #ifdef YAFFS_PARANOID
147 static int yaffs_CheckFileSanity(yaffs_Object *in);
148 #else
149 #define yaffs_CheckFileSanity(in)
150 #endif
151
152 static void yaffs_InvalidateWholeChunkCache(yaffs_Object *in);
153 static void yaffs_InvalidateChunkCache(yaffs_Object *object, int chunkId);
154
155 static int yaffs_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *buffer, yaffs_ExtendedTags *tags)
156 {
157         chunkInNAND -= dev->chunkOffset;
158         
159         if(dev->readChunkWithTagsFromNAND)
160                 return dev->readChunkWithTagsFromNAND(dev,chunkInNAND,buffer,tags);
161         else
162                 return yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(dev,chunkInNAND,buffer,tags);
163 }
164
165 static Y_INLINE int yaffs_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND, const __u8 *buffer, yaffs_ExtendedTags *tags)
166 {
167         chunkInNAND -= dev->chunkOffset;
168         
169         if(tags)
170         {
171                 tags->sequenceNumber = dev->sequenceNumber;
172                 tags->chunkUsed = 1;
173                 if(!yaffs_ValidateTags(tags))
174                 {
175                         T(YAFFS_TRACE_ERROR,(TSTR("Writing uninitialised tags" TENDSTR)));
176                         YBUG();
177                 }
178                 T(YAFFS_TRACE_WRITE,(TSTR("Writing chunk %d tags %d %d"TENDSTR),chunkInNAND,tags->objectId,tags->chunkId));
179         }
180         else
181         {
182                         T(YAFFS_TRACE_ERROR,(TSTR("Writing with no tags" TENDSTR)));
183                         YBUG();
184         }
185
186         if(dev->writeChunkWithTagsToNAND)
187                 return dev->writeChunkWithTagsToNAND(dev,chunkInNAND,buffer,tags);
188         else
189                 return yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(dev,chunkInNAND,buffer,tags);
190 }
191
192 static Y_INLINE int yaffs_MarkBlockBad(yaffs_Device *dev, int blockNo)
193 {
194         blockNo -= dev->blockOffset;
195         
196         if(dev->markNANDBlockBad)
197                 return dev->markNANDBlockBad(dev,blockNo);
198         else
199                 return yaffs_TagsCompatabilityMarkNANDBlockBad(dev,blockNo);
200 }
201 static Y_INLINE int yaffs_QueryInitialBlockState(yaffs_Device *dev,int blockNo, yaffs_BlockState *state, unsigned *sequenceNumber)
202 {
203         blockNo -= dev->blockOffset;
204         
205         if(dev->queryNANDBlock)
206                 return dev->queryNANDBlock(dev,blockNo,state,sequenceNumber);
207         else
208                 return yaffs_TagsCompatabilityQueryNANDBlock(dev,blockNo,state,sequenceNumber);
209 }
210
211 int yaffs_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,int blockInNAND)
212 {
213         int result;
214         
215         blockInNAND -= dev->blockOffset;
216
217         dev->nBlockErasures++;
218         result = dev->eraseBlockInNAND(dev,blockInNAND);
219
220         if(!result)result = dev->eraseBlockInNAND(dev,blockInNAND); // If at first we don't succeed, try again *once*.
221         return result;
222 }
223
224 static int yaffs_InitialiseNAND(struct yaffs_DeviceStruct *dev)
225 {
226         return dev->initialiseNAND(dev);
227 }
228
229
230
231
232 // Temporary buffer manipulations
233
234 static __u8 *yaffs_GetTempBuffer(yaffs_Device *dev,int lineNo)
235 {
236         int i,j;
237         for(i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
238         {
239                 if(dev->tempBuffer[i].line == 0)
240                 {
241                         dev->tempBuffer[i].line = lineNo;
242                         if((i+1) > dev->maxTemp)
243                         {
244                                 dev->maxTemp = i + 1;
245                                 for(j = 0; j <= i; j++)
246                                         dev->tempBuffer[j].maxLine = dev->tempBuffer[j].line;
247                         }       
248                         
249                         return dev->tempBuffer[i].buffer;
250                 }
251         }
252
253         T(YAFFS_TRACE_BUFFERS,(TSTR("Out of temp buffers at line %d, other held by lines:"),lineNo));
254         for(i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
255         {
256                 T(YAFFS_TRACE_BUFFERS,(TSTR(" %d "),dev->tempBuffer[i].line));
257         }
258         T(YAFFS_TRACE_BUFFERS,(TSTR(" "TENDSTR)));
259         
260         dev->unmanagedTempAllocations++;
261         // Get an unmanaged one
262         return YMALLOC(dev->nBytesPerChunk);    
263         
264         
265 }
266
267 static void yaffs_ReleaseTempBuffer(yaffs_Device *dev, __u8 *buffer, int lineNo)
268 {
269         int i;
270         for(i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
271         {
272                 if(dev->tempBuffer[i].buffer == buffer)
273                 {
274                         dev->tempBuffer[i].line = 0;
275                         return;
276                 }
277         }
278         
279         if(buffer)
280         {
281                 // assume it is an unmanaged one.
282                 T(YAFFS_TRACE_BUFFERS,(TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),lineNo));
283                 YFREE(buffer);
284                 dev->unmanagedTempDeallocations++;
285         }
286
287 }
288
289
290 // Chunk bitmap manipulations
291
292 static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device *dev, int blk)
293 {
294         if(blk < dev->internalStartBlock || blk > dev->internalEndBlock)
295         {
296                 T(YAFFS_TRACE_ERROR,(TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),blk));
297                 YBUG();
298         }
299         return dev->chunkBits + (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
300 }
301
302 static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device *dev,int blk)
303 {
304         __u8 *blkBits = yaffs_BlockBits(dev,blk);
305
306          memset(blkBits,0,dev->chunkBitmapStride);
307 }
308
309 static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device *dev,int blk,int chunk)
310 {
311         __u8 *blkBits = yaffs_BlockBits(dev,blk);
312         
313         blkBits[chunk/8] &=  ~ (1<<(chunk & 7));
314 }
315
316 static Y_INLINE void yaffs_SetChunkBit(yaffs_Device *dev,int blk,int chunk)
317 {
318         __u8 *blkBits = yaffs_BlockBits(dev,blk);
319
320         blkBits[chunk/8] |=   (1<<(chunk & 7));
321 }
322
323 static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device *dev,int blk,int chunk)
324 {
325         __u8 *blkBits = yaffs_BlockBits(dev,blk);
326         return (blkBits[chunk/8] &  (1<<(chunk & 7))) ? 1 :0;
327 }
328
329 static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device *dev,int blk)
330 {
331         __u8 *blkBits = yaffs_BlockBits(dev,blk);
332         int i;
333         for(i = 0; i < dev->chunkBitmapStride; i++)
334         {
335                 if(*blkBits) return 1;
336                 blkBits++;
337         }
338         return 0;
339 }
340
341
342 static  Y_INLINE int yaffs_HashFunction(int n)
343 {
344         return (n % YAFFS_NOBJECT_BUCKETS);
345 }
346
347
348 yaffs_Object *yaffs_Root(yaffs_Device *dev)
349 {
350         return dev->rootDir;
351 }
352
353 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev)
354 {
355         return dev->lostNFoundDir;
356 }
357
358
359
360
361 int yaffs_CheckFF(__u8 *buffer,int nBytes)
362 {
363         //Horrible, slow implementation
364         while(nBytes--)
365         {
366                 if(*buffer != 0xFF) return 0;
367                 buffer++;
368         }
369         return 1;
370 }
371
372 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,int chunkInNAND)
373 {
374
375         int retval = YAFFS_OK;
376         __u8 *data = yaffs_GetTempBuffer(dev,__LINE__);
377         yaffs_ExtendedTags tags;
378
379 // NCB          dev->readChunkWithTagsFromNAND(dev,chunkInNAND,data,&tags);
380         yaffs_ReadChunkWithTagsFromNAND(dev,chunkInNAND,data,&tags);
381         
382         if(!yaffs_CheckFF(data,dev->nBytesPerChunk) || tags.chunkUsed)
383         {
384                 T(YAFFS_TRACE_NANDACCESS,(TSTR("Chunk %d not erased" TENDSTR),chunkInNAND));
385                 retval = YAFFS_FAIL;
386         }
387
388         yaffs_ReleaseTempBuffer(dev,data,__LINE__);
389         
390         return retval;
391         
392 }
393
394
395
396 #if 1
397 static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev, const __u8 *data, yaffs_ExtendedTags *tags,int useReserve)
398 {
399         int chunk;
400         
401         int writeOk = 1;
402         int attempts = 0;
403         
404
405         
406         do{
407                 chunk = yaffs_AllocateChunk(dev,useReserve);
408         
409                 if(chunk >= 0)
410                 {
411
412                         // First check this chunk is erased...
413 #ifndef CONFIG_YAFFS_DISABLE_CHUNK_ERASED_CHECK
414                         writeOk = yaffs_CheckChunkErased(dev,chunk);
415 #endif          
416                         if(!writeOk)
417                         {
418                                 T(YAFFS_TRACE_ERROR,(TSTR("**>> yaffs chunk %d was not erased" TENDSTR),chunk));
419                         }
420                         else
421                         {
422                                 writeOk =  yaffs_WriteChunkWithTagsToNAND(dev,chunk,data,tags);
423                         }
424                         attempts++;
425
426                         if(writeOk)
427                         {
428                                 // Copy the data into the robustification buffer.
429                                 // NB We do this at the end to prevent duplicates in the case of a write error.
430                                 //Todo
431                                 yaffs_HandleWriteChunkOk(dev,chunk,data,tags);
432                         }
433                         else
434                         {
435                                 yaffs_HandleWriteChunkError(dev,chunk);
436                         }
437                 }
438                 
439         } while(chunk >= 0 && ! writeOk);
440         
441         if(attempts > 1)
442         {
443                 T(YAFFS_TRACE_ERROR,(TSTR("**>> yaffs write required %d attempts" TENDSTR),attempts));
444                 dev->nRetriedWrites+= (attempts - 1);   
445         }
446         
447
448         
449         return chunk;
450 }
451 #endif
452
453
454 ///
455 // Functions for robustisizing
456 //
457 //
458
459 static void yaffs_RetireBlock(yaffs_Device *dev,int blockInNAND)
460 {
461         
462         yaffs_MarkBlockBad(dev,blockInNAND);
463         
464         yaffs_GetBlockInfo(dev,blockInNAND)->blockState = YAFFS_BLOCK_STATE_DEAD;
465
466         dev->nRetiredBlocks++;
467 }
468
469
470 #if 0
471 static int yaffs_RewriteBufferedBlock(yaffs_Device *dev)
472 {
473         dev->doingBufferedBlockRewrite = 1;
474         //
475         //      Remove erased chunks
476         //  Rewrite existing chunks to a new block
477         //      Set current write block to the new block
478         
479         dev->doingBufferedBlockRewrite = 0;
480         
481         return 1;
482 }
483
484
485 static void yaffs_HandleReadDataError(yaffs_Device *dev,int chunkInNAND)
486 {
487         int blockInNAND = chunkInNAND/dev->nChunksPerBlock;
488
489         // Mark the block for retirement
490         yaffs_GetBlockInfo(dev,blockInNAND)->needsRetiring = 1;
491         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,(TSTR("**>>Block %d marked for retirement" TENDSTR),blockInNAND));
492
493
494         //TODO  
495         // Just do a garbage collection on the affected block then retire the block
496         // NB recursion
497 }
498
499
500 static void yaffs_CheckWrittenBlock(yaffs_Device *dev,int chunkInNAND)
501 {
502 }
503
504 #endif
505
506 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags)
507 {
508 }
509
510 static void yaffs_HandleUpdateChunk(yaffs_Device *dev,int chunkInNAND, const yaffs_ExtendedTags *tags)
511 {
512 }
513
514 static void yaffs_HandleWriteChunkError(yaffs_Device *dev,int chunkInNAND)
515 {
516         int blockInNAND = chunkInNAND/dev->nChunksPerBlock;
517
518         // Mark the block for retirement
519         yaffs_GetBlockInfo(dev,blockInNAND)->needsRetiring = 1;
520         // Delete the chunk
521         yaffs_DeleteChunk(dev,chunkInNAND,1,__LINE__);
522 }
523
524
525
526 #if 0
527 static int yaffs_VerifyCompare(const __u8 *d0, const __u8 * d1, const yaffs_Spare *s0, const yaffs_Spare *s1,int dataSize)
528 {
529
530
531         if( memcmp(d0,d1,dataSize) != 0 ||
532                 s0->tagByte0 != s1->tagByte0 ||
533                 s0->tagByte1 != s1->tagByte1 ||
534                 s0->tagByte2 != s1->tagByte2 ||
535                 s0->tagByte3 != s1->tagByte3 ||
536                 s0->tagByte4 != s1->tagByte4 ||
537                 s0->tagByte5 != s1->tagByte5 ||
538                 s0->tagByte6 != s1->tagByte6 ||
539                 s0->tagByte7 != s1->tagByte7 ||
540                 s0->ecc1[0]  != s1->ecc1[0]  ||
541                 s0->ecc1[1]  != s1->ecc1[1]  ||
542                 s0->ecc1[2]  != s1->ecc1[2]  ||
543                 s0->ecc2[0]  != s1->ecc2[0]  ||
544                 s0->ecc2[1]  != s1->ecc2[1]  ||
545                 s0->ecc2[2]  != s1->ecc2[2] )
546                 {
547                         return 0;
548                 }
549         
550         return 1;
551 }
552 #endif
553
554
555 ///////////////////////// Object management //////////////////
556 // List of spare objects
557 // The list is hooked together using the first pointer
558 // in the object
559
560 // static yaffs_Object *yaffs_freeObjects = NULL;
561
562 // static int yaffs_nFreeObjects;
563
564 // static yaffs_ObjectList *yaffs_allocatedObjectList = NULL;
565
566 // static yaffs_ObjectBucket yaffs_objectBucket[YAFFS_NOBJECT_BUCKETS];
567
568
569 static __u16 yaffs_CalcNameSum(const YCHAR *name)
570 {
571         __u16 sum = 0;
572         __u16 i = 1;
573         
574         YUCHAR *bname = (YUCHAR *)name;
575         if(bname)
576         {
577                 while ((*bname) && (i <=YAFFS_MAX_NAME_LENGTH))
578                 {
579
580 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
581                         sum += yaffs_toupper(*bname) * i;
582 #else
583                         sum += (*bname) * i;
584 #endif
585                         i++;
586                         bname++;
587                 }
588         }
589         return sum;
590 }
591
592 void yaffs_SetObjectName(yaffs_Object *obj, const YCHAR *name)
593 {
594 #ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
595                                         if(name && yaffs_strlen(name) <= YAFFS_SHORT_NAME_LENGTH)
596                                         {
597                                                 yaffs_strcpy(obj->shortName,name);
598                                         }
599                                         else
600                                         {
601                                                 obj->shortName[0]=_Y('\0');
602                                         }
603 #endif
604                                         obj->sum = yaffs_CalcNameSum(name);
605 }
606
607 #if 0
608 void yaffs_CalcECC(const __u8 *data, yaffs_Spare *spare)
609 {
610         yaffs_ECCCalculate(data , spare->ecc1);
611         yaffs_ECCCalculate(&data[256] , spare->ecc2);
612 }
613 #endif
614
615
616 ///////////////////////// TNODES ///////////////////////
617
618 // List of spare tnodes
619 // The list is hooked together using the first pointer
620 // in the tnode.
621
622 //static yaffs_Tnode *yaffs_freeTnodes = NULL;
623
624 // static int yaffs_nFreeTnodes;
625
626 //static yaffs_TnodeList *yaffs_allocatedTnodeList = NULL;
627
628
629
630 // yaffs_CreateTnodes creates a bunch more tnodes and
631 // adds them to the tnode free list.
632 // Don't use this function directly
633
634 static int yaffs_CreateTnodes(yaffs_Device *dev,int nTnodes)
635 {
636     int i;
637     yaffs_Tnode *newTnodes;
638     yaffs_TnodeList *tnl;
639     
640     if(nTnodes < 1) return YAFFS_OK;
641    
642         // make these things
643         
644     newTnodes = YMALLOC(nTnodes * sizeof(yaffs_Tnode));
645    
646     if (!newTnodes)
647     {
648                 T(YAFFS_TRACE_ERROR,(TSTR("yaffs: Could not allocate Tnodes"TENDSTR)));
649                 return YAFFS_FAIL;
650     }
651     
652     // Hook them into the free list
653     for(i = 0; i < nTnodes - 1; i++)
654     {
655         newTnodes[i].internal[0] = &newTnodes[i+1];
656 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
657         newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = 1;
658 #endif
659     }
660         
661         newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
662 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
663         newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = 1;
664 #endif
665         dev->freeTnodes = newTnodes;
666         dev->nFreeTnodes+= nTnodes;
667         dev->nTnodesCreated += nTnodes;
668
669         // Now add this bunch of tnodes to a list for freeing up.
670         // NB If we can't add this to the management list it isn't fatal
671         // but it just means we can't free this bunch of tnodes later.
672         tnl = YMALLOC(sizeof(yaffs_TnodeList));
673         if(!tnl)
674         {
675                 T(YAFFS_TRACE_ERROR,(TSTR("yaffs: Could not add tnodes to management list" TENDSTR)));
676                 
677         }
678         else
679         {
680                 tnl->tnodes = newTnodes;
681                 tnl->next = dev->allocatedTnodeList;
682                 dev->allocatedTnodeList = tnl;
683         }
684
685
686         T(YAFFS_TRACE_ALLOCATE,(TSTR("yaffs: Tnodes added" TENDSTR)));
687
688
689         return YAFFS_OK;
690 }
691
692
693 // GetTnode gets us a clean tnode. Tries to make allocate more if we run out
694 static yaffs_Tnode *yaffs_GetTnode(yaffs_Device *dev)
695 {
696         yaffs_Tnode *tn = NULL;
697         
698         // If there are none left make more
699         if(!dev->freeTnodes)
700         {
701                 yaffs_CreateTnodes(dev,YAFFS_ALLOCATION_NTNODES);
702         }
703         
704         if(dev->freeTnodes)
705         {
706                 tn = dev->freeTnodes;
707 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
708         if(tn->internal[YAFFS_NTNODES_INTERNAL] != 1)
709                 {
710                         // Hoosterman, this thing looks like it isn't in the list
711                                 T(YAFFS_TRACE_ALWAYS,(TSTR("yaffs: Tnode list bug 1" TENDSTR)));
712                 }
713 #endif
714                 dev->freeTnodes = dev->freeTnodes->internal[0];
715                 dev->nFreeTnodes--;
716                 // zero out
717                 memset(tn,0,sizeof(yaffs_Tnode));
718         }
719         
720
721         return tn;
722 }
723
724
725 // FreeTnode frees up a tnode and puts it back on the free list
726 static void yaffs_FreeTnode(yaffs_Device*dev, yaffs_Tnode *tn)
727 {
728         if(tn)
729         {
730 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
731         if(tn->internal[YAFFS_NTNODES_INTERNAL] != 0)
732                 {
733                         // Hoosterman, this thing looks like it is already in the list
734                                 T(YAFFS_TRACE_ALWAYS,(TSTR("yaffs: Tnode list bug 2" TENDSTR)));
735                 }
736                 tn->internal[YAFFS_NTNODES_INTERNAL] = 1;
737 #endif
738                 tn->internal[0] = dev->freeTnodes;
739                 dev->freeTnodes = tn;
740                 dev->nFreeTnodes++;
741         }
742 }
743
744
745 static void yaffs_DeinitialiseTnodes(yaffs_Device*dev)
746 {
747         // Free the list of allocated tnodes
748         yaffs_TnodeList *tmp;
749                 
750         while(dev->allocatedTnodeList)
751         {
752                 tmp =  dev->allocatedTnodeList->next;
753
754                 YFREE(dev->allocatedTnodeList->tnodes);
755                 YFREE(dev->allocatedTnodeList);
756                 dev->allocatedTnodeList = tmp;
757                 
758         }
759         
760         dev->freeTnodes = NULL;
761         dev->nFreeTnodes = 0;
762 }
763
764 static void yaffs_InitialiseTnodes(yaffs_Device*dev)
765 {
766         dev->allocatedTnodeList = NULL;
767         dev->freeTnodes = NULL;
768         dev->nFreeTnodes = 0;
769         dev->nTnodesCreated = 0;
770
771 }
772
773 #if 0
774 void yaffs_TnodeTest(yaffs_Device *dev)
775 {
776
777         int i;
778         int j;
779         yaffs_Tnode *tn[1000];
780         
781         YINFO("Testing TNodes");
782         
783         for(j = 0; j < 50; j++)
784         {
785                 for(i = 0; i < 1000; i++)
786                 {
787                         tn[i] = yaffs_GetTnode(dev);
788                         if(!tn[i])
789                         {
790                                 YALERT("Getting tnode failed");
791                         }
792                 }
793                 for(i = 0; i < 1000; i+=3)
794                 {
795                         yaffs_FreeTnode(dev,tn[i]);
796                         tn[i] = NULL;
797                 }
798                 
799         }
800 }
801 #endif
802
803
804 ////////////////// END OF TNODE MANIPULATION ///////////////////////////
805
806 /////////////// Functions to manipulate the look-up tree (made up of tnodes)
807 // The look up tree is represented by the top tnode and the number of topLevel
808 // in the tree. 0 means only the level 0 tnode is in the tree.
809
810
811 // FindLevel0Tnode finds the level 0 tnode, if one exists.
812 // Used when reading.....
813 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,yaffs_FileStructure *fStruct, __u32 chunkId)
814 {
815         
816         yaffs_Tnode *tn = fStruct->top;
817         __u32 i;
818         int requiredTallness;   
819         int level = fStruct->topLevel;
820         
821         // Check sane level and chunk Id
822         if(level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
823         {
824 //              char str[50];
825 //              sprintf(str,"Bad level %d",level);
826 //              YALERT(str);
827                 return NULL;
828         }
829         
830         if(chunkId > YAFFS_MAX_CHUNK_ID)
831         {
832 //              char str[50];
833 //              sprintf(str,"Bad chunkId %d",chunkId);
834 //              YALERT(str);
835                 return NULL;
836         }
837
838         // First check we're tall enough (ie enough topLevel)
839         
840         i = chunkId >> (/*dev->chunkGroupBits  + */YAFFS_TNODES_LEVEL0_BITS);
841         requiredTallness = 0;
842         while(i)
843         {
844                 i >>= YAFFS_TNODES_INTERNAL_BITS;
845                 requiredTallness++;
846         }
847         
848         
849         if(requiredTallness > fStruct->topLevel)
850         {
851                 // Not tall enough, so we can't find it, return NULL.
852                 return NULL;
853         }
854                 
855         
856         // Traverse down to level 0
857         while (level > 0 && tn)
858         {
859             tn = tn->internal[(chunkId >>(/* dev->chunkGroupBits + */ YAFFS_TNODES_LEVEL0_BITS + (level-1) * YAFFS_TNODES_INTERNAL_BITS)) & 
860                                YAFFS_TNODES_INTERNAL_MASK]; 
861                 level--;
862         
863         }
864         
865         return tn;              
866 }
867
868 // AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
869 // This happens in two steps:
870 //  1. If the tree isn't tall enough, then make it taller.
871 //  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
872 //
873 // Used when modifying the tree.
874 //
875 static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device *dev, yaffs_FileStructure *fStruct, __u32 chunkId)
876 {
877         
878         yaffs_Tnode *tn; 
879         
880         int requiredTallness;
881         int i;
882         int l;
883         
884         __u32 x;
885                 
886         
887         //T((TSTR("AddOrFind topLevel=%d, chunk=%d"),fStruct->topLevel,chunkId));
888         
889         // Check sane level and page Id
890         if(fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL)
891         {
892 //              char str[50];
893 //              sprintf(str,"Bad level %d",fStruct->topLevel);
894 //              YALERT(str);
895                 return NULL;
896         }
897         
898         if(chunkId > YAFFS_MAX_CHUNK_ID)
899         {
900 //              char str[50];
901 //              sprintf(str,"Bad chunkId %d",chunkId);
902 //              YALERT(str);
903                 return NULL;
904         }
905         
906         // First check we're tall enough (ie enough topLevel)
907         
908         x = chunkId >> (/*dev->chunkGroupBits + */YAFFS_TNODES_LEVEL0_BITS);
909         requiredTallness = 0;
910         while(x)
911         {
912                 x >>= YAFFS_TNODES_INTERNAL_BITS;
913                 requiredTallness++;
914         }
915         
916         //T((TSTR(" required=%d"),requiredTallness));
917         
918         
919         if(requiredTallness > fStruct->topLevel)
920         {
921                 // Not tall enough,gotta make the tree taller
922                 for(i = fStruct->topLevel; i < requiredTallness; i++)
923                 {
924                         //T((TSTR(" add new top")));
925                         
926                         tn = yaffs_GetTnode(dev);
927                         
928                         if(tn)
929                         {
930                                 tn->internal[0] = fStruct->top;
931                                 fStruct->top = tn;
932                         }
933                         else
934                         {
935                                         T(YAFFS_TRACE_ERROR,(TSTR("yaffs: no more tnodes" TENDSTR)));
936                         }
937                 }
938                 
939                 fStruct->topLevel = requiredTallness;
940         }
941         
942         
943         // Traverse down to level 0, adding anything we need
944         
945         l = fStruct->topLevel;
946         tn = fStruct->top;
947         while (l > 0 && tn)
948         {
949                 x = (chunkId >> (/*dev->chunkGroupBits + */YAFFS_TNODES_LEVEL0_BITS + (l-1) * YAFFS_TNODES_INTERNAL_BITS)) & 
950                                YAFFS_TNODES_INTERNAL_MASK;
951                                
952                 //T((TSTR(" [%d:%d]"),l,i));
953                 
954             if(!tn->internal[x])
955             {
956                 //T((TSTR(" added")));
957                 
958                 tn->internal[x] = yaffs_GetTnode(dev);
959             }
960             
961             tn =        tn->internal[x];
962                 l--;
963         
964         }
965         
966         //TSTR(TENDSTR)));
967         
968         return tn;              
969 }
970
971
972 int yaffs_FindChunkInGroup(yaffs_Device *dev, int theChunk, yaffs_ExtendedTags *tags, int objectId, int chunkInInode)
973 {
974         int j;
975         
976                                         
977         for(j = 0; theChunk && j < dev->chunkGroupSize; j++)
978         {
979                 if(yaffs_CheckChunkBit(dev,theChunk / dev->nChunksPerBlock,theChunk % dev->nChunksPerBlock))
980                 {
981                         yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL,tags);
982                         if(yaffs_TagsMatch(tags,objectId,chunkInInode))
983                         {
984                                 // found it;
985                                 return theChunk;
986                                         
987                         }
988                 }
989                 theChunk++;
990         }
991         return -1;
992 }
993
994 // DeleteWorker scans backwards through the tnode tree and deletes all the
995 // chunks and tnodes in the file
996 // Returns 1 if the tree was deleted. Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
997
998 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level, int chunkOffset,int *limit)
999 {
1000         int i;
1001         int chunkInInode;
1002         int theChunk;
1003         yaffs_ExtendedTags tags;
1004         int foundChunk;
1005         yaffs_Device *dev = in->myDev;
1006
1007         int allDone = 1;
1008         
1009         
1010         if(tn)
1011         {
1012                 if(level > 0)
1013                 {
1014                 
1015                         for(i = YAFFS_NTNODES_INTERNAL -1; allDone && i >= 0; i--)
1016                         {
1017                             if(tn->internal[i])
1018                         {
1019                                         if(limit && (*limit) < 0)
1020                                         {
1021                                                 allDone = 0;
1022                                         }
1023                                         else
1024                                         {
1025                                                 allDone = yaffs_DeleteWorker(in,tn->internal[i],level - 1,
1026                                                                                 (chunkOffset << YAFFS_TNODES_INTERNAL_BITS ) + i ,limit);
1027                                         }
1028                                         if(allDone)
1029                                         {
1030                                                 yaffs_FreeTnode(dev,tn->internal[i]);
1031                                         tn->internal[i] = NULL;
1032                                         }
1033                             }
1034                     
1035                         }
1036                         return (allDone) ? 1 : 0;
1037                 }
1038                 else if(level == 0)
1039                 {
1040                         int hitLimit = 0;
1041                         
1042                         for(i = YAFFS_NTNODES_LEVEL0 -1; i >= 0 && !hitLimit; i--)
1043                         {
1044                             if(tn->level0[i])
1045                         {
1046                                         
1047                                         chunkInInode = (chunkOffset << YAFFS_TNODES_LEVEL0_BITS ) + i;
1048                                         
1049                                         theChunk =  tn->level0[i] << dev->chunkGroupBits;
1050                                         
1051                                         foundChunk = yaffs_FindChunkInGroup(dev,theChunk,&tags,in->objectId,chunkInInode);
1052                                         
1053                                         if(foundChunk > 0)
1054                                         {
1055                                                 yaffs_DeleteChunk(dev,foundChunk,1,__LINE__);
1056                                                 in->nDataChunks--;
1057                                                 if(limit)
1058                                                 { 
1059                                                         *limit = *limit-1;
1060                                                         if(*limit <= 0) 
1061                                                         { 
1062                                                                 hitLimit = 1;
1063                                                         }
1064                                                 }
1065                                         
1066                                         }
1067                                         
1068                                 tn->level0[i] = 0;
1069                             }
1070                     
1071                         }
1072                         return (i < 0) ? 1 : 0;
1073
1074                         
1075                 }
1076                 
1077         }
1078         
1079         return 1;
1080         
1081 }
1082
1083
1084 static void yaffs_SoftDeleteChunk(yaffs_Device *dev, int chunk)
1085 {
1086
1087         yaffs_BlockInfo *theBlock;                                      
1088         
1089         T(YAFFS_TRACE_DELETION,(TSTR("soft delete chunk %d" TENDSTR),chunk));
1090                                                 
1091         theBlock =      yaffs_GetBlockInfo(dev,  chunk/dev->nChunksPerBlock);
1092         if(theBlock)
1093         {
1094                 theBlock->softDeletions++;
1095                 dev->nFreeChunks++;
1096         }
1097 }
1098
1099 // SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1100 // All soft deleting does is increment the block's softdelete count and pulls the chunk out
1101 // of the tnode.
1102 // THus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1103 //
1104 static int yaffs_SoftDeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level, int chunkOffset)
1105 {
1106         int i;
1107         int theChunk;
1108         int allDone = 1;
1109         yaffs_Device *dev = in->myDev;
1110         
1111         
1112         if(tn)
1113         {
1114                 if(level > 0)
1115                 {
1116                 
1117                         for(i = YAFFS_NTNODES_INTERNAL -1; allDone && i >= 0; i--)
1118                         {
1119                             if(tn->internal[i])
1120                         {
1121                                                 allDone = yaffs_SoftDeleteWorker(in,tn->internal[i],level - 1,
1122                                                                                 (chunkOffset << YAFFS_TNODES_INTERNAL_BITS ) + i);
1123                                         if(allDone)
1124                                         {
1125                                                 yaffs_FreeTnode(dev,tn->internal[i]);
1126                                         tn->internal[i] = NULL;
1127                                         }
1128                                         else
1129                                         {
1130                                                 //Hoosterman... how could this happen.
1131                                         }                           
1132                                 }                   
1133                         }
1134                         return (allDone) ? 1 : 0;
1135                 }
1136                 else if(level == 0)
1137                 {
1138                         
1139                         for(i = YAFFS_NTNODES_LEVEL0 -1; i >=0; i--)
1140                         {
1141                             if(tn->level0[i])
1142                         {
1143                                         // Note this does not find the real chunk, only the chunk group.
1144                                         // We make an assumption that a chunk group is niot larger than a block.
1145                                         theChunk =  (tn->level0[i] << dev->chunkGroupBits);
1146                                         
1147                                         yaffs_SoftDeleteChunk(dev,theChunk);
1148                                 tn->level0[i] = 0;
1149                             }
1150                     
1151                         }
1152                         return 1;
1153                         
1154                 }
1155                 
1156         }
1157         
1158         return 1;
1159                 
1160 }
1161
1162
1163
1164 static void yaffs_SoftDeleteFile(yaffs_Object *obj)
1165 {
1166         if(obj->deleted &&
1167            obj->variantType == YAFFS_OBJECT_TYPE_FILE &&
1168            !obj->softDeleted)
1169         {
1170                 if(obj->nDataChunks <= 0)
1171                 {
1172                                 // Empty file with no duplicate object headers, just delete it immediately
1173                                 yaffs_FreeTnode(obj->myDev,obj->variant.fileVariant.top);
1174                                 obj->variant.fileVariant.top = NULL;
1175                                 T(YAFFS_TRACE_TRACING,(TSTR("yaffs: Deleting empty file %d" TENDSTR),obj->objectId));
1176                                 yaffs_DoGenericObjectDeletion(obj);     
1177                 }
1178                 else
1179                 {
1180                         yaffs_SoftDeleteWorker(obj, obj->variant.fileVariant.top, obj->variant.fileVariant.topLevel, 0);
1181                         obj->softDeleted = 1;
1182                 }
1183         }
1184 }
1185
1186
1187
1188
1189
1190 // Pruning removes any part of the file structure tree that is beyond the
1191 // bounds of the file (ie that does not point to chunks).
1192 //
1193 // A file should only get pruned when its size is reduced.
1194 //
1195 // Before pruning, the chunks must be pulled from the tree and the
1196 // level 0 tnode entries must be zeroed out.
1197 // Could also use this for file deletion, but that's probably better handled
1198 // by a special case.
1199
1200 // yaffs_PruneWorker should only be called by yaffs_PruneFileStructure()
1201
1202 static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device *dev, yaffs_Tnode *tn, __u32 level, int del0)
1203 {
1204         int i;
1205         int hasData;
1206         
1207         if(tn)
1208         {
1209                 hasData = 0;
1210                 
1211                 for(i = 0; i < YAFFS_NTNODES_INTERNAL; i++)
1212                 {
1213                     if(tn->internal[i] && level > 0)
1214                     {
1215                         tn->internal[i] = yaffs_PruneWorker(dev,tn->internal[i],level - 1, ( i == 0) ? del0 : 1);
1216                     }
1217                     
1218                     if(tn->internal[i])
1219                     {
1220                         hasData++;
1221                         }
1222                 }
1223                 
1224                 if(hasData == 0 && del0)
1225                 {
1226                         // Free and return NULL
1227                         
1228                         yaffs_FreeTnode(dev,tn);
1229                         tn = NULL;
1230                 }
1231                 
1232         }
1233
1234         return tn;
1235         
1236 }
1237
1238 static int yaffs_PruneFileStructure(yaffs_Device *dev, yaffs_FileStructure *fStruct)
1239 {
1240         int i;
1241         int hasData;
1242         int done = 0;
1243         yaffs_Tnode *tn;
1244         
1245         if(fStruct->topLevel > 0)
1246         {
1247                 fStruct->top = yaffs_PruneWorker(dev,fStruct->top, fStruct->topLevel,0);
1248                 
1249                 // Now we have a tree with all the non-zero branches NULL but the height
1250                 // is the same as it was.
1251                 // Let's see if we can trim internal tnodes to shorten the tree.
1252                 // We can do this if only the 0th element in the tnode is in use 
1253                 // (ie all the non-zero are NULL)
1254                 
1255                 while(fStruct->topLevel && !done)
1256                 {
1257                         tn = fStruct->top;
1258                         
1259                         hasData = 0;
1260                         for(i = 1; i <YAFFS_NTNODES_INTERNAL; i++)
1261                         {
1262                                 if(tn->internal[i])
1263                         {
1264                                 hasData++;
1265                                 }
1266                         }
1267                         
1268                         if(!hasData)
1269                         {
1270                                 fStruct->top = tn->internal[0];
1271                                 fStruct->topLevel--;
1272                                 yaffs_FreeTnode(dev,tn);
1273                         }
1274                         else
1275                         {
1276                                 done = 1;
1277                         }
1278                 }
1279         }
1280         
1281         return YAFFS_OK;
1282 }
1283
1284
1285
1286
1287
1288 /////////////////////// End of File Structure functions. /////////////////
1289
1290 // yaffs_CreateFreeObjects creates a bunch more objects and
1291 // adds them to the object free list.
1292 static int yaffs_CreateFreeObjects(yaffs_Device *dev, int nObjects)
1293 {
1294     int i;
1295     yaffs_Object *newObjects;
1296     yaffs_ObjectList *list;
1297     
1298     if(nObjects < 1) return YAFFS_OK;
1299    
1300         // make these things
1301         
1302     newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
1303    
1304     if (!newObjects)
1305     {
1306                 T(YAFFS_TRACE_ALLOCATE,(TSTR("yaffs: Could not allocate more objects" TENDSTR)));
1307                 return YAFFS_FAIL;
1308     }
1309     
1310     // Hook them into the free list
1311     for(i = 0; i < nObjects - 1; i++)
1312     {
1313         newObjects[i].siblings.next = (struct list_head *)(&newObjects[i+1]);
1314     }
1315         
1316         newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
1317         dev->freeObjects = newObjects;
1318         dev->nFreeObjects+= nObjects;
1319         dev->nObjectsCreated+= nObjects;
1320         
1321         // Now add this bunch of Objects to a list for freeing up.
1322         
1323         list = YMALLOC(sizeof(yaffs_ObjectList));
1324         if(!list)
1325         {
1326                 T(YAFFS_TRACE_ALLOCATE,(TSTR("Could not add objects to management list" TENDSTR)));
1327         }
1328         else
1329         {
1330                 list->objects = newObjects;
1331                 list->next = dev->allocatedObjectList;
1332                 dev->allocatedObjectList = list;
1333         }
1334         
1335         
1336         
1337         return YAFFS_OK;
1338 }
1339
1340
1341 // AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out
1342 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
1343 {
1344         yaffs_Object *tn = NULL;
1345         
1346         // If there are none left make more
1347         if(!dev->freeObjects)
1348         {
1349                 yaffs_CreateFreeObjects(dev,YAFFS_ALLOCATION_NOBJECTS);
1350         }
1351         
1352         if(dev->freeObjects)
1353         {
1354                 tn = dev->freeObjects;
1355                 dev->freeObjects = (yaffs_Object *)(dev->freeObjects->siblings.next);
1356                 dev->nFreeObjects--;
1357                 
1358                 // Now sweeten it up...
1359         
1360                 memset(tn,0,sizeof(yaffs_Object));
1361                 tn->myDev = dev;
1362                 tn->chunkId = -1;
1363                 tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
1364                 INIT_LIST_HEAD(&(tn->hardLinks));
1365                 INIT_LIST_HEAD(&(tn->hashLink));
1366                 INIT_LIST_HEAD(&tn->siblings);
1367                 
1368                 // Add it to the lost and found directory.
1369                 // NB Can't put root or lostNFound in lostNFound so
1370                 // check if lostNFound exists first
1371                 if(dev->lostNFoundDir)
1372                 {
1373                         yaffs_AddObjectToDirectory(dev->lostNFoundDir,tn);      
1374                 }
1375         }
1376         
1377
1378         return tn;
1379 }
1380
1381 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev,int number,__u32 mode)
1382 {
1383
1384         yaffs_Object *obj = yaffs_CreateNewObject(dev,number,YAFFS_OBJECT_TYPE_DIRECTORY);              
1385         if(obj)
1386         {
1387                 obj->fake = 1;                  // it is fake so it has no NAND presence...
1388                 obj->renameAllowed= 0;  // ... and we're not allowed to rename it...
1389                 obj->unlinkAllowed= 0;  // ... or unlink it
1390                 obj->deleted = 0;
1391                 obj->unlinked = 0;
1392                 obj->yst_mode = mode;
1393                 obj->myDev = dev;
1394                 obj->chunkId = 0; // Not a valid chunk.
1395         }
1396         
1397         return obj;
1398         
1399 }
1400
1401
1402 static void yaffs_UnhashObject(yaffs_Object *tn)
1403 {
1404         int bucket;
1405         yaffs_Device *dev = tn->myDev;
1406         
1407         
1408         // If it is still linked into the bucket list, free from the list
1409         if(!list_empty(&tn->hashLink))
1410         {
1411                 list_del_init(&tn->hashLink);
1412                 bucket =  yaffs_HashFunction(tn->objectId);
1413                 dev->objectBucket[bucket].count--;
1414         }
1415         
1416 }
1417
1418
1419 // FreeObject frees up a Object and puts it back on the free list
1420 static void yaffs_FreeObject(yaffs_Object *tn)
1421 {
1422
1423         yaffs_Device *dev = tn->myDev;
1424         
1425 #ifdef  __KERNEL__
1426         if(tn->myInode)
1427         {
1428                 // We're still hooked up to a cached inode.
1429                 // Don't delete now, but mark for later deletion
1430                 tn->deferedFree = 1;
1431                 return;
1432         }
1433 #endif
1434         
1435         yaffs_UnhashObject(tn);
1436         
1437         // Link into the free list.
1438         tn->siblings.next = (struct list_head *)(dev->freeObjects);
1439         dev->freeObjects = tn;
1440         dev->nFreeObjects++;
1441 }
1442
1443
1444
1445 #ifdef __KERNEL__
1446
1447 void yaffs_HandleDeferedFree(yaffs_Object *obj)
1448 {
1449         if(obj->deferedFree)
1450         {
1451            yaffs_FreeObject(obj);
1452         }
1453 }
1454
1455 #endif
1456
1457
1458
1459 static void yaffs_DeinitialiseObjects(yaffs_Device *dev)
1460 {
1461         // Free the list of allocated Objects
1462         
1463         yaffs_ObjectList *tmp;
1464         
1465         while( dev->allocatedObjectList)
1466         {
1467                 tmp =  dev->allocatedObjectList->next;
1468                 YFREE(dev->allocatedObjectList->objects);
1469                 YFREE(dev->allocatedObjectList);
1470                 
1471                 dev->allocatedObjectList =  tmp;
1472         }
1473         
1474         dev->freeObjects = NULL;
1475         dev->nFreeObjects = 0;
1476 }
1477
1478 static void yaffs_InitialiseObjects(yaffs_Device *dev)
1479 {
1480         int i;
1481         
1482         dev->allocatedObjectList = NULL;
1483         dev->freeObjects = NULL;
1484         dev->nFreeObjects = 0;
1485         
1486         for(i = 0; i < YAFFS_NOBJECT_BUCKETS; i++)
1487         {
1488                 INIT_LIST_HEAD(&dev->objectBucket[i].list);
1489                 dev->objectBucket[i].count = 0; 
1490         }
1491
1492 }
1493
1494
1495
1496
1497
1498
1499 int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
1500 {
1501         static int x = 0;
1502         int i;
1503         int l = 999;
1504         int lowest = 999999;
1505
1506                 
1507         // First let's see if we can find one that's empty.
1508         
1509         for(i = 0; i < 10 && lowest > 0; i++)
1510          {
1511                 x++;
1512                 x %=  YAFFS_NOBJECT_BUCKETS;
1513                 if(dev->objectBucket[x].count < lowest)
1514                 {
1515                         lowest = dev->objectBucket[x].count;
1516                         l = x;
1517                 }
1518                 
1519         }
1520         
1521         // If we didn't find an empty list, then try
1522         // looking a bit further for a short one
1523         
1524         for(i = 0; i < 10 && lowest > 3; i++)
1525          {
1526                 x++;
1527                 x %=  YAFFS_NOBJECT_BUCKETS;
1528                 if(dev->objectBucket[x].count < lowest)
1529                 {
1530                         lowest = dev->objectBucket[x].count;
1531                         l = x;
1532                 }
1533                 
1534         }
1535         
1536         return l;
1537 }
1538
1539 static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
1540 {
1541         int bucket = yaffs_FindNiceObjectBucket(dev);
1542         
1543         // Now find an object value that has not already been taken
1544         // by scanning the list.
1545         
1546         int found = 0;
1547         struct list_head *i;
1548         
1549         __u32 n = (__u32)bucket;
1550
1551         //yaffs_CheckObjectHashSanity();        
1552         
1553         while(!found)
1554         {
1555                 found = 1;
1556                 n +=  YAFFS_NOBJECT_BUCKETS;
1557                 if(1 ||dev->objectBucket[bucket].count > 0)
1558                 {
1559                         list_for_each(i,&dev->objectBucket[bucket].list)
1560                         {
1561                                 // If there is already one in the list
1562                                 if(i && list_entry(i, yaffs_Object,hashLink)->objectId == n)
1563                                 {
1564                                         found = 0;
1565                                 }
1566                         }
1567                 }
1568         }
1569         
1570         //T(("bucket %d count %d inode %d\n",bucket,yaffs_objectBucket[bucket].count,n);
1571         
1572         return n;       
1573 }
1574
1575 void yaffs_HashObject(yaffs_Object *in)
1576 {
1577         int bucket = yaffs_HashFunction(in->objectId);
1578         yaffs_Device *dev = in->myDev;
1579         
1580         if(!list_empty(&in->hashLink))
1581         {
1582                 //YINFO("!!!");
1583         }
1584
1585         
1586         list_add(&in->hashLink,&dev->objectBucket[bucket].list);
1587         dev->objectBucket[bucket].count++;
1588
1589 }
1590
1591 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,__u32 number)
1592 {
1593         int bucket = yaffs_HashFunction(number);
1594         struct list_head *i;
1595         yaffs_Object *in;
1596         
1597         list_for_each(i,&dev->objectBucket[bucket].list)
1598         {
1599                 // Look if it is in the list
1600                 if(i)
1601                 {
1602                         in = list_entry(i, yaffs_Object,hashLink);
1603                         if(in->objectId == number)
1604                         {
1605 #ifdef __KERNEL__
1606                                 // Don't tell the VFS about this one if it is defered free
1607                                 if(in->deferedFree)
1608                                   return NULL;
1609 #endif
1610                                   
1611                                 return in;
1612                         }
1613                 }
1614         }
1615         
1616         return NULL;
1617 }
1618
1619
1620
1621 yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev,int number,yaffs_ObjectType type)
1622 {
1623                 
1624         yaffs_Object *theObject;
1625
1626         if(number < 0)
1627         {
1628                 number = yaffs_CreateNewObjectNumber(dev);
1629         }
1630         
1631         theObject = yaffs_AllocateEmptyObject(dev);
1632         
1633         if(theObject)
1634         {
1635                 theObject->fake = 0;
1636                 theObject->renameAllowed = 1;
1637                 theObject->unlinkAllowed = 1;
1638                 theObject->objectId = number;
1639                 yaffs_HashObject(theObject);
1640                 theObject->variantType = type;
1641 #ifdef CONFIG_YAFFS_WINCE
1642                 yfsd_WinFileTimeNow(theObject->win_atime);
1643                 theObject->win_ctime[0] = theObject->win_mtime[0] = theObject->win_atime[0];
1644                 theObject->win_ctime[1] = theObject->win_mtime[1] = theObject->win_atime[1];
1645
1646 #else
1647
1648                 theObject->yst_atime = theObject->yst_mtime = theObject->yst_ctime = Y_CURRENT_TIME;            
1649 #endif
1650                 switch(type)
1651                 {
1652                         case YAFFS_OBJECT_TYPE_FILE: 
1653                                 theObject->variant.fileVariant.fileSize = 0;
1654                                 theObject->variant.fileVariant.scannedFileSize = 0;
1655                                 theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; // max __u32
1656                                 theObject->variant.fileVariant.topLevel = 0;
1657                                 theObject->variant.fileVariant.top  = yaffs_GetTnode(dev);
1658                                 break;
1659                         case YAFFS_OBJECT_TYPE_DIRECTORY:
1660                                 INIT_LIST_HEAD(&theObject->variant.directoryVariant.children);
1661                                 break;
1662                         case YAFFS_OBJECT_TYPE_SYMLINK:
1663                                 // No action required
1664                                 break;
1665                         case YAFFS_OBJECT_TYPE_HARDLINK:
1666                                 // No action required
1667                                 break;
1668                         case YAFFS_OBJECT_TYPE_SPECIAL:
1669                                 // No action required
1670                                 break;
1671                         case YAFFS_OBJECT_TYPE_UNKNOWN:
1672                                 // todo this should not happen
1673                                 break;
1674                 }
1675         }
1676         
1677         return theObject;
1678 }
1679
1680 yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev, int number,yaffs_ObjectType type)
1681 {
1682         yaffs_Object *theObject = NULL;
1683         
1684         if(number > 0)
1685         {
1686                 theObject = yaffs_FindObjectByNumber(dev,number);
1687         }
1688         
1689         if(!theObject)
1690         {
1691                 theObject = yaffs_CreateNewObject(dev,number,type);
1692         }
1693         
1694         return theObject;
1695
1696 }
1697
1698 YCHAR *yaffs_CloneString(const YCHAR *str)
1699 {
1700         YCHAR *newStr = NULL;
1701         
1702         if(str && *str)
1703         {
1704                 newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
1705                 yaffs_strcpy(newStr,str);
1706         }
1707
1708         return newStr;
1709         
1710 }
1711
1712 //
1713 // Mknod (create) a new object.
1714 // equivalentObject only has meaning for a hard link;
1715 // aliasString only has meaning for a sumlink.
1716 // rdev only has meaning for devices (a subset of special objects)
1717 yaffs_Object *yaffs_MknodObject( yaffs_ObjectType type,
1718                                                                  yaffs_Object *parent,
1719                                                                  const YCHAR *name, 
1720                                                                  __u32 mode,
1721                                                                  __u32 uid,
1722                                                                  __u32 gid,
1723                                                                  yaffs_Object *equivalentObject,
1724                                                                  const YCHAR *aliasString,
1725                                                                  __u32 rdev)
1726 {
1727         yaffs_Object *in;
1728
1729         yaffs_Device *dev = parent->myDev;
1730         
1731         // Check if the entry exists. If it does then fail the call since we don't want a dup.
1732         if(yaffs_FindObjectByName(parent,name))
1733         {
1734                 return NULL;
1735         }
1736         
1737         in = yaffs_CreateNewObject(dev,-1,type);
1738         
1739         if(in)
1740         {
1741                 in->chunkId = -1;
1742                 in->valid = 1;
1743                 in->variantType = type;
1744
1745                 in->yst_mode  = mode;
1746                 
1747 #ifdef CONFIG_YAFFS_WINCE
1748                 yfsd_WinFileTimeNow(in->win_atime);
1749                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
1750                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
1751                 
1752 #else
1753                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
1754
1755                 in->yst_rdev  = rdev;
1756                 in->yst_uid   = uid;
1757                 in->yst_gid   = gid;
1758 #endif          
1759                 in->nDataChunks = 0;
1760
1761                 yaffs_SetObjectName(in,name);
1762                 in->dirty = 1;
1763                 
1764                 yaffs_AddObjectToDirectory(parent,in);
1765                 
1766                 in->myDev = parent->myDev;
1767                 
1768                                 
1769                 switch(type)
1770                 {
1771                         case YAFFS_OBJECT_TYPE_SYMLINK:
1772                                 in->variant.symLinkVariant.alias = yaffs_CloneString(aliasString);
1773                                 break;
1774                         case YAFFS_OBJECT_TYPE_HARDLINK:
1775                                 in->variant.hardLinkVariant.equivalentObject = equivalentObject;
1776                                 in->variant.hardLinkVariant.equivalentObjectId = equivalentObject->objectId;
1777                                 list_add(&in->hardLinks,&equivalentObject->hardLinks);
1778                                 break;
1779                         case YAFFS_OBJECT_TYPE_FILE: // do nothing
1780                         case YAFFS_OBJECT_TYPE_DIRECTORY: // do nothing
1781                         case YAFFS_OBJECT_TYPE_SPECIAL: // do nothing
1782                         case YAFFS_OBJECT_TYPE_UNKNOWN:
1783                                 break;
1784                 }
1785
1786                 if(/*yaffs_GetNumberOfFreeChunks(dev) <= 0 || */
1787                    yaffs_UpdateObjectHeader(in,name,0,0) < 0)
1788                 {
1789                         // Could not create the object header, fail the creation
1790                         yaffs_DestroyObject(in);
1791                         in = NULL;
1792                 }
1793
1794         }
1795         
1796         return in;
1797 }
1798
1799 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const YCHAR *name, __u32 mode, __u32 uid, __u32 gid)
1800 {
1801         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE,parent,name,mode,uid,gid,NULL,NULL,0);
1802 }
1803
1804 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const YCHAR *name, __u32 mode, __u32 uid, __u32 gid)
1805 {
1806         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY,parent,name,mode,uid,gid,NULL,NULL,0);
1807 }
1808
1809 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent,const YCHAR *name, __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
1810 {
1811         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL,parent,name,mode,uid,gid,NULL,NULL,rdev);
1812 }
1813
1814 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent,const YCHAR *name, __u32 mode, __u32 uid, __u32 gid,const YCHAR *alias)
1815 {
1816         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK,parent,name,mode,uid,gid,NULL,alias,0);
1817 }
1818
1819 // NB yaffs_Link returns the object id of the equivalent object.
1820 yaffs_Object *yaffs_Link(yaffs_Object *parent, const YCHAR *name, yaffs_Object *equivalentObject)
1821 {
1822         // Get the real object in case we were fed a hard link as an equivalent object
1823         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
1824         
1825         if(yaffs_MknodObject(YAFFS_OBJECT_TYPE_HARDLINK,parent,name,0,0,0,equivalentObject,NULL,0))
1826         {
1827                 return equivalentObject;
1828         }
1829         else
1830         {
1831                 return NULL;
1832         }
1833         
1834 }
1835
1836
1837 static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir, const YCHAR *newName,int force)
1838 {
1839         int unlinkOp;
1840         int deleteOp;
1841
1842         if(newDir == NULL)
1843         {
1844                 newDir = obj->parent; // use the old directory
1845         }
1846         
1847         if(newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
1848         {
1849                 T(YAFFS_TRACE_ALWAYS,(TSTR("tragendy: yaffs_ChangeObjectName: newDir is not a directory"TENDSTR)));
1850                 YBUG();
1851         }
1852
1853         // TODO: Do we need this different handling for YAFFS2 and YAFFS1??
1854         if(obj->myDev->isYaffs2)
1855         {
1856                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
1857         }
1858         else
1859         {
1860                 unlinkOp = (newDir == obj->myDev->unlinkedDir && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
1861         }
1862
1863         deleteOp = (newDir == obj->myDev->deletedDir);
1864         
1865         // If the object is a file going into the unlinked directory, then it is OK to just stuff it in since
1866         // duplicate names are allowed.
1867         // Otherwise only proceed if the new name does not exist and if we're putting it into a directory.
1868         if( (unlinkOp|| 
1869                  deleteOp ||
1870                  force || 
1871                  !yaffs_FindObjectByName(newDir,newName))  &&
1872              newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY)
1873         {
1874                 yaffs_SetObjectName(obj,newName);
1875                 obj->dirty = 1;
1876                 
1877                 yaffs_AddObjectToDirectory(newDir,obj);
1878                 
1879                 if(unlinkOp) obj->unlinked = 1;
1880                 
1881                 // If it is a deletion then we mark it as a shrink for gc purposes.
1882                 if(yaffs_UpdateObjectHeader(obj,newName,0,deleteOp) >= 0)
1883                 {
1884                         return YAFFS_OK;
1885                 }
1886         }
1887         
1888         return YAFFS_FAIL;
1889 }
1890
1891
1892
1893 int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName, yaffs_Object *newDir, const YCHAR *newName)
1894 {
1895         yaffs_Object *obj;
1896         int force = 0;
1897         
1898 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
1899         // Special case for case insemsitive systems (eg. WinCE).
1900         // While look-up is case insensitive, the name isn't.
1901         // THerefore we might want to change x.txt to X.txt
1902         if(oldDir == newDir && yaffs_strcmp(oldName,newName) == 0)
1903         {
1904                 force = 1;
1905         }       
1906 #endif
1907         
1908         obj = yaffs_FindObjectByName(oldDir,oldName);
1909         if(obj && obj->renameAllowed)
1910         {
1911                 return yaffs_ChangeObjectName(obj,newDir,newName,force);
1912         }
1913         return YAFFS_FAIL;
1914 }
1915
1916
1917 #if 0
1918
1919 static int yaffs_CheckObjectHashSanity(yaffs_Device *dev)
1920 {
1921         // Scan the buckets and check that the lists 
1922         // have as many members as the count says there are
1923         int bucket;
1924         int countEm;
1925         struct list_head *j;
1926         int ok = YAFFS_OK;
1927         
1928         for(bucket = 0; bucket < YAFFS_NOBJECT_BUCKETS; bucket++)
1929         {
1930                 countEm = 0;
1931                 
1932                 list_for_each(j,&dev->objectBucket[bucket].list)
1933                 {
1934                         countEm++;
1935                 }
1936                 
1937                 if(countEm != dev->objectBucket[bucket].count)
1938                 {
1939                         T(YAFFS_TRACE_ERROR,(TSTR("Inode hash inconsistency" TENDSTR)));
1940                         ok = YAFFS_FAIL;
1941                 }
1942         }
1943
1944         return ok;
1945 }
1946
1947
1948 void yaffs_ObjectTest(yaffs_Device *dev)
1949 {
1950         yaffs_Object *in[1000];
1951         int inNo[1000];
1952         yaffs_Object *inold[1000];
1953         int i;
1954         int j;
1955         
1956         memset(in,0,1000*sizeof(yaffs_Object *));
1957         memset(inold,0,1000*sizeof(yaffs_Object *));
1958         
1959         yaffs_CheckObjectHashSanity(dev);
1960         
1961         for(j = 0; j < 10; j++)
1962         {
1963                 //T(("%d\n",j));
1964                 
1965                 for(i = 0; i < 1000; i++)
1966                 {
1967                         in[i] = yaffs_CreateNewObject(dev,-1,YAFFS_OBJECT_TYPE_FILE);
1968                         if(!in[i])
1969                         {
1970                                 YINFO("No more inodes");
1971                         }
1972                         else
1973                         {
1974                                 inNo[i] = in[i]->objectId;
1975                         }
1976                 }
1977                 
1978                 for(i = 0; i < 1000; i++)
1979                 {
1980                         if(yaffs_FindObjectByNumber(dev,inNo[i]) != in[i])
1981                         {
1982                                 //T(("Differnce in look up test\n"));
1983                         }
1984                         else
1985                         {
1986                                 // T(("Look up ok\n"));
1987                         }
1988                 }
1989                 
1990                 yaffs_CheckObjectHashSanity(dev);
1991         
1992                 for(i = 0; i < 1000; i+=3)
1993                 {
1994                         yaffs_FreeObject(in[i]);        
1995                         in[i] = NULL;
1996                 }
1997                 
1998         
1999                 yaffs_CheckObjectHashSanity(dev);
2000         }
2001                 
2002 }
2003
2004 #endif
2005
2006 /////////////////////////// Block Management and Page Allocation ///////////////////
2007
2008
2009 static int yaffs_InitialiseBlocks(yaffs_Device *dev,int nBlocks)
2010 {
2011         dev->allocationBlock = -1; // force it to get a new one
2012         //Todo we're assuming the malloc will pass.
2013         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
2014         // Set up dynamic blockinfo stuff.
2015         dev->chunkBitmapStride = (dev->nChunksPerBlock+7)/8;
2016         dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
2017         if(dev->blockInfo && dev->chunkBits)
2018         {
2019                 memset(dev->blockInfo,0,nBlocks * sizeof(yaffs_BlockInfo));
2020                 memset(dev->chunkBits,0,dev->chunkBitmapStride * nBlocks);
2021                 return YAFFS_OK;
2022         }
2023         
2024         return YAFFS_FAIL;
2025         
2026 }
2027
2028 static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
2029 {
2030         YFREE(dev->blockInfo);
2031         dev->blockInfo = NULL;
2032         YFREE(dev->chunkBits);
2033         dev->chunkBits = NULL;
2034 }
2035
2036
2037 static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device *dev, yaffs_BlockInfo *bi)
2038 {
2039         int i;
2040         __u32 seq;
2041         yaffs_BlockInfo *b;
2042         
2043         if(!dev->isYaffs2) return 1; // disqualification only applies to yaffs2.
2044         
2045         if(!bi->hasShrinkHeader) return 1; // can gc
2046
2047
2048         // Find the oldest dirty sequence number if we don't know it and save it
2049         // so we don't have to keep recomputing it.
2050         if(!dev->oldestDirtySequence)
2051         {
2052                 seq = dev->sequenceNumber;
2053
2054                 for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++)
2055                 {
2056                         b = yaffs_GetBlockInfo(dev,i);
2057                         if(b->blockState == YAFFS_BLOCK_STATE_FULL &&
2058                         (b->pagesInUse - b->softDeletions )< dev->nChunksPerBlock &&
2059                         b->sequenceNumber < seq)
2060                         {
2061                                 seq = b->sequenceNumber;
2062                         }
2063                 }
2064                 dev->oldestDirtySequence = seq;
2065         }
2066
2067
2068         // Can't do gc of this block if there are any blocks older than this one that have
2069         // discarded pages.
2070         return (bi->sequenceNumber <= dev->oldestDirtySequence);
2071         
2072         
2073         return 1;
2074
2075 }
2076
2077 // FindDiretiestBlock is used to select the dirtiest block (or close enough)
2078 // for garbage collection.
2079 //
2080
2081
2082
2083 static int yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,int aggressive)
2084 {
2085
2086         int b = dev->currentDirtyChecker;
2087         
2088         int i;
2089         int iterations;
2090         int dirtiest = -1;
2091         int pagesInUse; 
2092         yaffs_BlockInfo *bi;
2093         static int  nonAggressiveSkip = 0;
2094
2095         // If we're doing aggressive GC then we are happy to take a less-dirty block, and
2096         // search harder.
2097         // else (we're doing a leasurely gc), then we only bother to do this if the
2098         // block has only a few pages in use.
2099         
2100
2101         nonAggressiveSkip--;
2102
2103         if(!aggressive &&(nonAggressiveSkip > 0))
2104         {
2105                 return -1;
2106         }
2107
2108         pagesInUse = (aggressive)? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
2109
2110         if(aggressive)
2111         {
2112                 iterations = dev->internalEndBlock - dev->internalStartBlock + 1;
2113         }
2114         else
2115         {
2116                 iterations = dev->internalEndBlock - dev->internalStartBlock + 1;
2117                 iterations = iterations / 16; 
2118                 if(iterations > 200)
2119                 {
2120                         iterations = 200;
2121                 }
2122         }
2123         
2124         for(i = 0; i <= iterations && pagesInUse > 0 ; i++)
2125         {
2126                 b++;
2127                 if ( b < dev->internalStartBlock || b > dev->internalEndBlock)
2128                 {
2129                         b =  dev->internalStartBlock;
2130                 }
2131
2132                 if(b < dev->internalStartBlock || b > dev->internalEndBlock)
2133                 {
2134                         T(YAFFS_TRACE_ERROR,(TSTR("**>> Block %d is not valid" TENDSTR),b));
2135                         YBUG();
2136                 }
2137                 
2138                 bi = yaffs_GetBlockInfo(dev,b);
2139                 
2140                 if(bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2141                    (bi->pagesInUse - bi->softDeletions )< pagesInUse &&
2142                    yaffs_BlockNotDisqualifiedFromGC(dev,bi))
2143                 {
2144                         dirtiest = b;
2145                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2146                 }
2147         }
2148         
2149         dev->currentDirtyChecker = b;
2150         
2151         if(dirtiest > 0)
2152         {
2153                 T(YAFFS_TRACE_GC,(TSTR("GC Selected block %d with %d free" TENDSTR),dirtiest,dev->nChunksPerBlock - pagesInUse));
2154         }
2155         
2156         dev->oldestDirtySequence = 0; // clear this
2157         
2158         if(dirtiest > 0)
2159         {
2160                 nonAggressiveSkip = 4;
2161         }
2162
2163         return dirtiest;
2164 }
2165
2166
2167 static void yaffs_BlockBecameDirty(yaffs_Device *dev,int blockNo)
2168 {
2169         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,blockNo);
2170         
2171         int erasedOk = 0;
2172         
2173         // If the block is still healthy erase it and mark as clean.
2174         // If the block has had a data failure, then retire it.
2175         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
2176
2177         if(!bi->needsRetiring)
2178         {
2179                 erasedOk = yaffs_EraseBlockInNAND(dev,blockNo);
2180                 if(!erasedOk)
2181                 {
2182                         dev->nErasureFailures++;
2183                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,(TSTR("**>> Erasure failed %d" TENDSTR),blockNo));
2184                 }
2185         }
2186
2187         if(erasedOk && (yaffs_traceMask & YAFFS_TRACE_ERASE))
2188         {
2189                         int i;
2190                         for(i = 0; i < dev->nChunksPerBlock; i++)
2191                         {
2192                                         if(!yaffs_CheckChunkErased(dev,blockNo * dev->nChunksPerBlock + i))
2193                                         {
2194                                                 T(YAFFS_TRACE_ERROR,(TSTR(">>Block %d erasure supposedly OK, but chunk %d not erased" TENDSTR),blockNo,i));
2195                                         }
2196                         }
2197         }
2198         
2199         if( erasedOk )
2200         {
2201                 // Clean it up...
2202                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
2203                 dev->nErasedBlocks++;
2204                 bi->pagesInUse = 0;
2205                 bi->softDeletions = 0;
2206                 bi->hasShrinkHeader=0;
2207                 yaffs_ClearChunkBits(dev,blockNo);
2208         
2209                 T(YAFFS_TRACE_ERASE,(TSTR("Erased block %d" TENDSTR),blockNo));
2210         }
2211         else
2212         {
2213                 dev->nFreeChunks -= dev->nChunksPerBlock; // We lost a block of free space
2214                 
2215                 yaffs_RetireBlock(dev,blockNo);
2216                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,(TSTR("**>> Block %d retired" TENDSTR),blockNo));
2217         }
2218 }
2219
2220 #if 0
2221 static void yaffs_DumpBlockStats(yaffs_Device *dev)
2222 {
2223         int i,j;
2224         yaffs_BlockInfo *bi;
2225         
2226         for(i= dev->internalStartBlock; i <=dev->internalEndBlock; i++)
2227         {
2228                 bi = yaffs_GetBlockInfo(dev,i);
2229                 T(YAFFS_TRACE_ALLOCATE,(TSTR("%3d state %d shrink %d inuse %d/%d seq %d pages"),i,
2230                 bi->blockState,bi->hasShrinkHeader,bi->pagesInUse,bi->softDeletions,bi->sequenceNumber));       
2231                 
2232                 for(j = 0; j < dev->nChunksPerBlock; j++)
2233                 {
2234                         if(yaffs_CheckChunkBit(dev,i,j))
2235                         {
2236                                 T(YAFFS_TRACE_ALLOCATE,(TSTR(" %d"),j));
2237
2238                         }
2239                 }
2240                 T(YAFFS_TRACE_ALLOCATE,(TSTR(" " TENDSTR)));
2241
2242         }
2243 }
2244 #endif
2245
2246
2247 static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
2248 {
2249         int i;
2250         
2251         yaffs_BlockInfo *bi;
2252         
2253 #if 0
2254         static int j = 0;
2255         j++;
2256         if(j < 0 || j > 100)
2257         {
2258                 j = 0;
2259                 yaffs_DumpBlockStats(dev);
2260         }
2261         
2262 #endif
2263         
2264         if(dev->nErasedBlocks < 1)
2265         {
2266                 // Hoosterman we've got a problem.
2267                 // Can't get space to gc
2268                 T(YAFFS_TRACE_ERROR, (TSTR("yaffs tragedy: no more eraased blocks" TENDSTR)));
2269
2270                 return -1;
2271         }
2272         
2273         // Find an empty block.
2274         
2275         for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++)
2276         {
2277                 dev->allocationBlockFinder++;
2278                 if(dev->allocationBlockFinder < dev->internalStartBlock || dev->allocationBlockFinder> dev->internalEndBlock) 
2279                 {
2280                         dev->allocationBlockFinder = dev->internalStartBlock;
2281                 }
2282                 
2283                 bi = yaffs_GetBlockInfo(dev,dev->allocationBlockFinder);
2284
2285                 if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY)
2286                 {
2287                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
2288                         dev->sequenceNumber++;
2289                         bi->sequenceNumber = dev->sequenceNumber;
2290                         dev->nErasedBlocks--;           
2291                         T(YAFFS_TRACE_ALLOCATE,(TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),dev->allocationBlockFinder,dev->sequenceNumber, dev->nErasedBlocks));      
2292                         return dev->allocationBlockFinder;
2293                 }
2294         }
2295         
2296         
2297         T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs tragedy: no more eraased blocks, but there should have been %d" TENDSTR),dev->nErasedBlocks));
2298         
2299         
2300         
2301
2302         
2303         return -1;      
2304 }
2305
2306
2307 // To determine if we have enough space we just look at the 
2308 // number of erased blocks.
2309
2310 static int yaffs_CheckSpaceForAllocation(yaffs_Device *dev)
2311 {
2312         int reservedChunks = (dev->nReservedBlocks * dev->nChunksPerBlock);
2313         return (dev->nFreeChunks > reservedChunks);
2314 }
2315
2316
2317 static int yaffs_AllocateChunk(yaffs_Device *dev,int useReserve)
2318 {
2319         int retVal;
2320         yaffs_BlockInfo *bi;
2321         
2322         if(dev->allocationBlock < 0)
2323         {
2324                 // Get next block to allocate off
2325                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
2326                 dev->allocationPage = 0;
2327         }
2328         
2329         if(!useReserve &&  !yaffs_CheckSpaceForAllocation(dev))
2330         {
2331                 // Not enough space to allocate unless we're allowed to use the reserve.
2332                 return -1;
2333         }
2334
2335         if(dev->nErasedBlocks < dev->nReservedBlocks && dev->allocationPage == 0)
2336         {
2337                 T(YAFFS_TRACE_ALLOCATE,(TSTR("Allocating reserve" TENDSTR)));   
2338         }
2339
2340         
2341         // Next page please....
2342         if(dev->allocationBlock >= 0)
2343         {
2344                 bi = yaffs_GetBlockInfo(dev,dev->allocationBlock);
2345                 
2346                 retVal = (dev->allocationBlock * dev->nChunksPerBlock) + 
2347                                   dev->allocationPage;
2348                 bi->pagesInUse++;
2349                 yaffs_SetChunkBit(dev,dev->allocationBlock,dev->allocationPage);
2350
2351                 dev->allocationPage++;
2352                 
2353                 dev->nFreeChunks--;
2354                 
2355                 // If the block is full set the state to full
2356                 if(dev->allocationPage >= dev->nChunksPerBlock)
2357                 {
2358                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2359                         dev->allocationBlock = -1;
2360                 }
2361
2362
2363                 return retVal;
2364                 
2365         }
2366         T(YAFFS_TRACE_ERROR,(TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
2367
2368         return -1;      
2369 }
2370
2371
2372
2373
2374 static int yaffs_GetErasedChunks(yaffs_Device *dev)
2375 {
2376                 int n;
2377
2378                 n = dev->nErasedBlocks * dev->nChunksPerBlock;
2379
2380                 if(dev->allocationBlock> 0)
2381                 {
2382                         n += (dev->nChunksPerBlock - dev->allocationPage);
2383                 }
2384
2385                 return n;
2386
2387 }
2388
2389 int  yaffs_GarbageCollectBlock(yaffs_Device *dev,int block)
2390 {
2391         int oldChunk;
2392         int newChunk;
2393         int chunkInBlock;
2394         int markNAND;
2395         int retVal = YAFFS_OK;
2396         int cleanups = 0;
2397         int i;
2398
2399         int chunksBefore = yaffs_GetErasedChunks(dev);
2400         int chunksAfter;
2401
2402         yaffs_ExtendedTags  tags;
2403         
2404         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,block);
2405         
2406         yaffs_Object *object;
2407         
2408         bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
2409
2410         T(YAFFS_TRACE_TRACING,(TSTR("Collecting block %d, in use %d, shrink %d, " TENDSTR),block,bi->pagesInUse,bi->hasShrinkHeader));
2411         //T(("Collecting block %d n %d bits %x\n",block, bi->pagesInUse, bi->pageBits));        
2412         
2413         //yaffs_VerifyFreeChunks(dev);
2414
2415         bi->hasShrinkHeader = 0; // clear the flag so that the block can erase
2416         
2417         dev->nFreeChunks -= bi->softDeletions;  // Take off the number of soft deleted entries because
2418                                                 // they're going to get really deleted during GC.
2419
2420
2421         if(!yaffs_StillSomeChunkBits(dev,block))
2422         {
2423                 T(YAFFS_TRACE_TRACING,(TSTR("Collecting block %d that has no chunks in use" TENDSTR),block));
2424                 yaffs_BlockBecameDirty(dev,block);
2425         }
2426         else
2427         {
2428
2429         __u8  *buffer = yaffs_GetTempBuffer(dev,__LINE__);
2430
2431         for(chunkInBlock = 0,oldChunk = block * dev->nChunksPerBlock; 
2432             chunkInBlock < dev->nChunksPerBlock && yaffs_StillSomeChunkBits(dev,block);
2433             chunkInBlock++, oldChunk++ )
2434         {
2435                 if(yaffs_CheckChunkBit(dev,block,chunkInBlock))
2436                 {
2437                         
2438                         // This page is in use and might need to be copied off
2439                         
2440                         markNAND = 1;
2441                         
2442                         //T(("copying page %x from %d to %d\n",mask,oldChunk,newChunk));
2443                         
2444                         yaffs_InitialiseTags(&tags);
2445                         
2446                         yaffs_ReadChunkWithTagsFromNAND(dev,oldChunk,buffer, &tags);
2447
2448                         object = yaffs_FindObjectByNumber(dev,tags.objectId);
2449                         
2450                         T(YAFFS_TRACE_GC_DETAIL,(TSTR("Collecting page %d, %d %d %d " TENDSTR),chunkInBlock,tags.objectId,tags.chunkId,tags.byteCount));
2451                         
2452                         if(!object)
2453                         {
2454                                 T(YAFFS_TRACE_ERROR,(TSTR("page %d in gc has no object " TENDSTR),oldChunk));
2455                         }
2456                         
2457                         if(object && object->deleted && tags.chunkId != 0)
2458                         {
2459                                 // Data chunk in a deleted file, throw it away
2460                                 // It's a soft deleted data chunk,
2461                                 // No need to copy this, just forget about it and fix up the
2462                                 // object.
2463                                 
2464                                 //yaffs_PutChunkIntoFile(object, tags.chunkId, 0,0); 
2465                                 object->nDataChunks--;
2466                                 
2467                                 if(object->nDataChunks <= 0)
2468                                 {
2469                                         // remeber to clean up the object
2470                                         dev->gcCleanupList[cleanups] = tags.objectId;
2471                                         cleanups++;
2472                                 }
2473                                 markNAND = 0;
2474                         }
2475                         else if( 0 /* Todo object && object->deleted && object->nDataChunks == 0 */)
2476                         {
2477                                 // Deleted object header with no data chunks.
2478                                 // Can be discarded and the file deleted.
2479                                 object->chunkId = 0;
2480                                 yaffs_FreeTnode(object->myDev,object->variant.fileVariant.top);
2481                                 object->variant.fileVariant.top = NULL;
2482                                 yaffs_DoGenericObjectDeletion(object);
2483                                 
2484                         }
2485                         else if(object)
2486                         {
2487                                 // It's either a data chunk in a live file or
2488                                 // an ObjectHeader, so we're interested in it.
2489                                 // NB Need to keep the ObjectHeaders of deleted files
2490                                 // until the whole file has been deleted off
2491                                 tags.serialNumber++;
2492
2493                                 dev->nGCCopies++;
2494
2495                                 newChunk = yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags,1);
2496                         
2497                                 if(newChunk < 0)
2498                                 {
2499                                         retVal =  YAFFS_FAIL;
2500                                 }
2501                                 else
2502                                 {
2503                         
2504                                         // Ok, now fix up the Tnodes etc.
2505                         
2506                                         if(tags.chunkId == 0)
2507                                         {
2508                                                 // It's a header
2509                                                 object->chunkId = newChunk;
2510                                                 object->serial = tags.serialNumber;
2511                                         }
2512                                         else
2513                                         {
2514                                                 // It's a data chunk
2515                                                 yaffs_PutChunkIntoFile(object, tags.chunkId, newChunk,0);
2516                                         }
2517                                 }
2518                         }
2519                         
2520                         yaffs_DeleteChunk(dev,oldChunk,markNAND,__LINE__);                      
2521                         
2522                 }
2523         }
2524
2525         yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
2526
2527         //yaffs_VerifyFreeChunks(dev);
2528
2529         // Do any required cleanups
2530         for(i = 0; i < cleanups; i++)
2531         {                                               
2532                 // Time to delete the file too
2533                 object =  yaffs_FindObjectByNumber(dev,dev->gcCleanupList[i]);
2534                 if(object)
2535                 {
2536                         yaffs_FreeTnode(dev,object->variant.fileVariant.top);
2537                         object->variant.fileVariant.top = NULL;
2538                         T(YAFFS_TRACE_GC,(TSTR("yaffs: About to finally delete object %d" TENDSTR),object->objectId));
2539                         yaffs_DoGenericObjectDeletion(object);
2540                 }
2541
2542         }
2543
2544         }
2545
2546         if(chunksBefore >= (chunksAfter = yaffs_GetErasedChunks(dev)))
2547         {
2548                         T(YAFFS_TRACE_GC,(TSTR("gc did not increase free chunks before %d after %d" TENDSTR),chunksBefore,chunksAfter));
2549         }
2550         
2551         
2552         //yaffs_VerifyFreeChunks(dev);
2553                         
2554         return YAFFS_OK;
2555 }
2556
2557 #if 0
2558 static yaffs_Object *yaffs_FindDeletedUnlinkedFile(yaffs_Device *dev)
2559 {
2560         // find a file to delete
2561         struct list_head *i;    
2562         yaffs_Object *l;
2563
2564
2565         //Scan the unlinked files looking for one to delete
2566         list_for_each(i,&dev->unlinkedDir->variant.directoryVariant.children)
2567         {
2568                 if(i)
2569                 {
2570                         l = list_entry(i, yaffs_Object,siblings);
2571                         if(l->deleted)
2572                         {
2573                                 return l;                       
2574                         }
2575                 }
2576         }       
2577         return NULL;
2578 }
2579
2580
2581 static void yaffs_DoUnlinkedFileDeletion(yaffs_Device *dev)
2582 {
2583         // This does background deletion on unlinked files.. only deleted ones.
2584         // If we don't have a file we're working on then find one
2585         if(!dev->unlinkedDeletion && dev->nDeletedFiles > 0)
2586         {
2587                 dev->unlinkedDeletion = yaffs_FindDeletedUnlinkedFile(dev);
2588         }
2589         
2590         // OK, we're working on a file...
2591         if(dev->unlinkedDeletion)
2592         {
2593                 yaffs_Object *obj = dev->unlinkedDeletion;
2594                 int delresult;
2595                 int limit; // Number of chunks to delete in a file.
2596                                    // NB this can be exceeded, but not by much.
2597                                    
2598                 limit = -1;
2599
2600                 delresult = yaffs_DeleteWorker(obj, obj->variant.fileVariant.top, obj->variant.fileVariant.topLevel, 0,&limit);
2601                 
2602                 if(obj->nDataChunks == 0)
2603                 {
2604                         // Done all the deleting of data chunks.
2605                         // Now dump the header and clean up
2606                         yaffs_FreeTnode(dev,obj->variant.fileVariant.top);
2607                         obj->variant.fileVariant.top = NULL;
2608                         yaffs_DoGenericObjectDeletion(obj);
2609                         dev->nDeletedFiles--;
2610                         dev->nUnlinkedFiles--;
2611                         dev->nBackgroundDeletions++;
2612                         dev->unlinkedDeletion = NULL;   
2613                 }
2614         }
2615 }
2616
2617 #endif
2618
2619
2620
2621 // New garbage collector
2622 // If we're very low on erased blocks then we do aggressive garbage collection
2623 // otherwise we do "leasurely" garbage collection.
2624 // Aggressive gc looks further (whole array) and will accept dirtier blocks.
2625 // Passive gc only inspects smaller areas and will only accept cleaner blocks.
2626 //
2627 // The idea is to help clear out space in a more spread-out manner.
2628 // Dunno if it really does anything useful.
2629 //
2630 int yaffs_CheckGarbageCollection(yaffs_Device *dev)
2631 {
2632         int block;
2633         int aggressive; 
2634         int gcOk = YAFFS_OK;
2635         int maxTries = 0;
2636         
2637         //yaffs_DoUnlinkedFileDeletion(dev);
2638         
2639         //yaffs_VerifyFreeChunks(dev);
2640
2641         // This loop should pass the first time.
2642         // We'll only see looping here if the erase of the collected block fails.
2643         
2644         do{
2645                 maxTries++;
2646                 if(dev->nErasedBlocks < dev->nReservedBlocks)
2647                 {
2648                         // We need a block soon...
2649                         aggressive = 1;
2650                 }
2651                 else 
2652                 {
2653                         // We're in no hurry
2654                         aggressive = 0;
2655                 }
2656         
2657                 block = yaffs_FindBlockForGarbageCollection(dev,aggressive);
2658         
2659                 if(block > 0)
2660                 {
2661                         dev->garbageCollections++;
2662                         if(!aggressive)
2663                         {
2664                                 dev->passiveGarbageCollections++;
2665                         }
2666
2667                         T(YAFFS_TRACE_GC,(TSTR("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),dev->nErasedBlocks,aggressive));
2668
2669                         gcOk =  yaffs_GarbageCollectBlock(dev,block);
2670                 }
2671
2672                 if(dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) 
2673                 {
2674                         T(YAFFS_TRACE_GC,(TSTR("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d" TENDSTR),dev->nErasedBlocks,maxTries,block));
2675                 }
2676         } while((dev->nErasedBlocks < dev->nReservedBlocks) && (block > 0) && (maxTries < 2));
2677
2678         return aggressive ? gcOk: YAFFS_OK;
2679 }
2680
2681
2682 //////////////////////////// TAGS ///////////////////////////////////////
2683
2684
2685
2686 #if 0
2687
2688 void yaffs_CalcTagsECC(yaffs_Tags *tags)
2689 {
2690         // Calculate an ecc
2691         
2692         unsigned char *b = ((yaffs_TagsUnion *)tags)->asBytes;
2693         unsigned  i,j;
2694         unsigned  ecc = 0;
2695         unsigned bit = 0;
2696
2697         tags->ecc = 0;
2698         
2699         for(i = 0; i < 8; i++)
2700         {
2701                 for(j = 1; j &0xff; j<<=1)
2702                 {
2703                         bit++;
2704                         if(b[i] & j)
2705                         {
2706                                 ecc ^= bit;
2707                         }
2708                 }
2709         }
2710         
2711         tags->ecc = ecc;
2712         
2713         
2714 }
2715
2716 int  yaffs_CheckECCOnTags(yaffs_Tags *tags)
2717 {
2718         unsigned ecc = tags->ecc;
2719         
2720         yaffs_CalcTagsECC(tags);
2721         
2722         ecc ^= tags->ecc;
2723         
2724         if(ecc && ecc <= 64)
2725         {
2726                 // TODO: Handle the failure better. Retire?
2727                 unsigned char *b = ((yaffs_TagsUnion *)tags)->asBytes;
2728
2729                 ecc--;
2730                                 
2731                 b[ecc / 8] ^= (1 << (ecc & 7));
2732                 
2733                 // Now recvalc the ecc
2734                 yaffs_CalcTagsECC(tags);
2735                 
2736                 return 1; // recovered error
2737         }
2738         else if(ecc)
2739         {
2740                 // Wierd ecc failure value
2741                 // TODO Need to do somethiong here
2742                 return -1; //unrecovered error
2743         }
2744         
2745         return 0;
2746 }
2747
2748 static void yaffs_LoadTagsIntoSpare(yaffs_Spare *sparePtr, yaffs_Tags *tagsPtr)
2749 {
2750         yaffs_TagsUnion *tu = (yaffs_TagsUnion *)tagsPtr;
2751         
2752         yaffs_CalcTagsECC(tagsPtr);
2753         
2754         sparePtr->tagByte0 = tu->asBytes[0];
2755         sparePtr->tagByte1 = tu->asBytes[1];
2756         sparePtr->tagByte2 = tu->asBytes[2];
2757         sparePtr->tagByte3 = tu->asBytes[3];
2758         sparePtr->tagByte4 = tu->asBytes[4];
2759         sparePtr->tagByte5 = tu->asBytes[5];
2760         sparePtr->tagByte6 = tu->asBytes[6];
2761         sparePtr->tagByte7 = tu->asBytes[7];
2762 }
2763
2764 static void yaffs_GetTagsFromSpare(yaffs_Device *dev, yaffs_Spare *sparePtr,yaffs_Tags *tagsPtr)
2765 {
2766         yaffs_TagsUnion *tu = (yaffs_TagsUnion *)tagsPtr;
2767         int result;
2768
2769         tu->asBytes[0]= sparePtr->tagByte0;
2770         tu->asBytes[1]= sparePtr->tagByte1;
2771         tu->asBytes[2]= sparePtr->tagByte2;
2772         tu->asBytes[3]= sparePtr->tagByte3;
2773         tu->asBytes[4]= sparePtr->tagByte4;
2774         tu->asBytes[5]= sparePtr->tagByte5;
2775         tu->asBytes[6]= sparePtr->tagByte6;
2776         tu->asBytes[7]= sparePtr->tagByte7;
2777         
2778         result =  yaffs_CheckECCOnTags(tagsPtr);
2779         if(result> 0)
2780         {
2781                 dev->tagsEccFixed++;
2782         }
2783         else if(result <0)
2784         {
2785                 dev->tagsEccUnfixed++;
2786         }
2787 }
2788
2789 static void yaffs_SpareInitialise(yaffs_Spare *spare)
2790 {
2791         memset(spare,0xFF,sizeof(yaffs_Spare));
2792 }
2793
2794 #endif
2795
2796 #if 0
2797 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev, const __u8 *buffer, yaffs_ExtendedTags *tags, int useReserve)
2798 {
2799         // NB There must be tags, data is optional
2800         // If there is data, then an ECC is calculated on it.
2801         
2802         yaffs_Spare spare;
2803         
2804         if(!tags)
2805         {
2806                 return YAFFS_FAIL;
2807         }
2808         
2809         //yaffs_SpareInitialise(&spare);
2810         
2811         //if(!dev->useNANDECC && buffer)
2812         //{
2813         //      yaffs_CalcECC(buffer,&spare);
2814         //}
2815         
2816         //yaffs_LoadTagsIntoSpare(&spare,tags);
2817         
2818         return yaffs_WriteNewChunkToNAND(dev,buffer,&spare,useReserve);
2819         
2820 }
2821 #endif
2822
2823 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId, int chunkInObject)
2824 {
2825         return  (  tags->chunkId == chunkInObject &&
2826                            tags->objectId == objectId &&
2827                            !tags->chunkDeleted) ? 1 : 0;
2828         
2829 }
2830
2831 /////////////////////////////////////////////////////////////////////////////////////////////////////////
2832
2833
2834 int yaffs_FindChunkInFile(yaffs_Object *in,int chunkInInode,yaffs_ExtendedTags *tags)
2835 {
2836         //Get the Tnode, then get the level 0 offset chunk offset
2837     yaffs_Tnode *tn;     
2838     int theChunk = -1;
2839     yaffs_ExtendedTags localTags;
2840     int retVal = -1;
2841     
2842     yaffs_Device *dev = in->myDev;
2843     
2844     
2845     if(!tags)
2846     {
2847         // Passed a NULL, so use our own tags space
2848         tags = &localTags;
2849     }
2850     
2851     tn = yaffs_FindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
2852     
2853     if(tn)
2854     {
2855                 theChunk = tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] << dev->chunkGroupBits;
2856                 
2857                 retVal = yaffs_FindChunkInGroup(dev,theChunk,tags,in->objectId,chunkInInode);
2858     }
2859     return retVal;
2860 }
2861
2862 int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in,int chunkInInode,yaffs_ExtendedTags *tags)
2863 {
2864         //Get the Tnode, then get the level 0 offset chunk offset
2865     yaffs_Tnode *tn;     
2866     int theChunk = -1;
2867     yaffs_ExtendedTags localTags;
2868
2869     yaffs_Device *dev = in->myDev;
2870     int retVal = -1;
2871     
2872     if(!tags)
2873     {
2874         // Passed a NULL, so use our own tags space
2875         tags = &localTags;
2876     }
2877     
2878     tn = yaffs_FindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
2879     
2880     if(tn)
2881     {
2882     
2883                 theChunk = tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] << dev->chunkGroupBits;
2884                 
2885                 retVal = yaffs_FindChunkInGroup(dev,theChunk,tags,in->objectId,chunkInInode);
2886     
2887                 // Delete the entry in the filestructure (if found)
2888                 if(retVal != -1)
2889                 {
2890                         tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] = 0;
2891                 }
2892     }
2893     else
2894     {
2895         //T(("No level 0 found for %d\n", chunkInInode));
2896     }
2897     
2898     if(retVal == -1)
2899     {
2900         //T(("Could not find %d to delete\n",chunkInInode));
2901     }
2902     return retVal;
2903 }
2904
2905
2906 #ifdef YAFFS_PARANOID
2907
2908 static int yaffs_CheckFileSanity(yaffs_Object *in)
2909 {
2910         int chunk;
2911         int nChunks;
2912         int fSize;
2913         int failed = 0;
2914         int objId;
2915         yaffs_Tnode *tn;
2916     yaffs_Tags localTags;
2917     yaffs_Tags *tags = &localTags;
2918     int theChunk;
2919     int chunkDeleted;
2920     
2921         
2922         if(in->variantType != YAFFS_OBJECT_TYPE_FILE)
2923         {
2924                 //T(("Object not a file\n"));
2925                 return YAFFS_FAIL;
2926         }
2927         
2928         objId = in->objectId;
2929         fSize  = in->variant.fileVariant.fileSize;
2930         nChunks = (fSize + in->myDev->nBytesPerChunk -1)/in->myDev->nBytesPerChunk;
2931         
2932         for(chunk = 1; chunk <= nChunks; chunk++)
2933         {
2934                 tn = yaffs_FindLevel0Tnode(in->myDev,&in->variant.fileVariant, chunk);
2935     
2936                 if(tn)
2937                 {
2938     
2939                         theChunk = tn->level0[chunk & YAFFS_TNODES_LEVEL0_MASK] << in->myDev->chunkGroupBits;
2940                         
2941                 if(yaffs_CheckChunkBits(dev,theChunk/dev->nChunksPerBlock,theChunk%dev->nChunksPerBlock))
2942                         {
2943
2944
2945                                 yaffs_ReadChunkTagsFromNAND(in->myDev,theChunk,tags,&chunkDeleted);
2946                                 if(yaffs_TagsMatch(tags,in->objectId,chunk,chunkDeleted))
2947                                 {
2948                                         // found it;
2949                                 
2950                                 }
2951                         }
2952                         else
2953                         {
2954                                 //T(("File problem file [%d,%d] NAND %d  tags[%d,%d]\n",
2955                                 //              objId,chunk,theChunk,tags->chunkId,tags->objectId);
2956                                                 
2957                                 failed = 1;
2958                                                         
2959                         }
2960     
2961                 }
2962                 else
2963                 {
2964                         //T(("No level 0 found for %d\n", chunk));
2965                 }
2966         }
2967         
2968         return failed ? YAFFS_FAIL : YAFFS_OK;
2969 }
2970
2971 #endif
2972
2973 static int yaffs_PutChunkIntoFile(yaffs_Object *in,int chunkInInode, int chunkInNAND, int inScan)
2974 {
2975         // NB inScan is zero unless scanning. For forward scanning, inScan is > 0; for backward scanning inScan is < 0
2976         yaffs_Tnode *tn;
2977         yaffs_Device *dev = in->myDev;
2978         int existingChunk;
2979         yaffs_ExtendedTags existingTags;
2980         yaffs_ExtendedTags newTags;
2981         unsigned existingSerial, newSerial;
2982         
2983         if(in->variantType != YAFFS_OBJECT_TYPE_FILE)
2984         {
2985                 // Just ignore an attempt at putting a chunk into a non-file during scanning
2986                 // If it is not during Scanning then something went wrong!
2987                 if(!inScan)
2988                 {
2989                         T(YAFFS_TRACE_ERROR, (TSTR("yaffs tragedy:attempt to put data chunk into a non-file" TENDSTR)));
2990                         YBUG();
2991                 }
2992                 
2993                 yaffs_DeleteChunk(dev,chunkInNAND,1,__LINE__);
2994                 return YAFFS_OK;
2995         }
2996                 
2997         tn = yaffs_AddOrFindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
2998         if(!tn)
2999         {
3000                 return YAFFS_FAIL;
3001         }
3002
3003         existingChunk = tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK];            
3004         
3005         if(inScan != 0)
3006         {
3007                 // If we're scanning then we need to test for duplicates
3008                 // NB This does not need to be efficient since it should only ever 
3009                 // happen when the power fails during a write, then only one
3010                 // chunk should ever be affected.
3011                 //
3012                 // Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
3013                 // Update: For backward scanning we don't need to re-read tags so this is quite cheap.
3014                 
3015         
3016                 
3017                 if(existingChunk != 0)
3018                 {
3019                         // NB Right now existing chunk will not be real chunkId if the device >= 32MB
3020                         //    thus we have to do a FindChunkInFile to get the real chunk id.
3021                         //
3022                         // We have a duplicate now we need to decide which one to use:
3023                         //
3024                         // Backwards scanning YAFFS2: The old one is what we use, dump the new one.
3025                         // Forward scanning YAFFS2: The new one is what we use, dump the old one.
3026                         // YAFFS1: Get both sets of tags and compare serial numbers.
3027                         //
3028                         //
3029                         
3030                         if(inScan > 0)
3031                         {
3032                                 // Only do this for forward scanning
3033                                 yaffs_ReadChunkWithTagsFromNAND(dev,chunkInNAND, NULL,&newTags);
3034                         
3035                         
3036                                 // Do a proper find
3037                                 existingChunk = yaffs_FindChunkInFile(in,chunkInInode, &existingTags);
3038                         }
3039
3040                         if(existingChunk <=0)
3041                         {
3042                                 //Hoosterman - how did this happen?
3043                                 
3044                                 T(YAFFS_TRACE_ERROR, (TSTR("yaffs tragedy: existing chunk < 0 in scan" TENDSTR)));
3045
3046                         }
3047
3048                         
3049                         // NB The deleted flags should be false, otherwise the chunks will 
3050                         // not be loaded during a scan
3051                         
3052                         newSerial = newTags.serialNumber;
3053                         existingSerial = existingTags.serialNumber;
3054                         
3055                         if( (inScan > 0) &&
3056                             ( in->myDev->isYaffs2  ||
3057                               existingChunk <= 0 ||
3058                              ((existingSerial+1) & 3) == newSerial))
3059                         {
3060                                 // Forward scanning.                            
3061                                 // Use new
3062                                 // Delete the old one and drop through to update the tnode
3063                                 yaffs_DeleteChunk(dev,existingChunk,1,__LINE__);
3064                         }
3065                         else
3066                         {
3067                                 // Backward scanning or we want to use the existing one
3068                                 // Use existing.
3069                                 // Delete the new one and return early so that the tnode isn't changed
3070                                 yaffs_DeleteChunk(dev,chunkInNAND,1,__LINE__);
3071                                 return YAFFS_OK;
3072                         }
3073                 }
3074
3075         }
3076                 
3077         if(existingChunk == 0)
3078         {
3079                 in->nDataChunks++;
3080         }
3081         
3082         tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] = (chunkInNAND >> dev->chunkGroupBits);
3083         
3084         return YAFFS_OK;
3085 }
3086
3087
3088
3089 int yaffs_ReadChunkDataFromObject(yaffs_Object *in,int chunkInInode, __u8 *buffer)
3090 {
3091     int chunkInNAND = yaffs_FindChunkInFile(in,chunkInInode,NULL);
3092     
3093     if(chunkInNAND >= 0)
3094     {
3095                 return yaffs_ReadChunkWithTagsFromNAND(in->myDev,chunkInNAND,buffer,NULL);
3096         }
3097         else
3098         {
3099                 T(YAFFS_TRACE_NANDACCESS,(TSTR("Chunk %d not found zero instead" TENDSTR),chunkInNAND));
3100
3101                 memset(buffer,0,in->myDev->nBytesPerChunk); // get sane data if you read a hole
3102                 return 0;
3103         }
3104
3105 }
3106
3107
3108 void yaffs_DeleteChunk(yaffs_Device *dev,int chunkId,int markNAND,int lyn)
3109 {
3110         int block;
3111         int page;
3112         yaffs_ExtendedTags tags;
3113         yaffs_BlockInfo *bi;
3114         
3115         if(chunkId <= 0) return;        
3116         
3117         dev->nDeletions++;
3118         block = chunkId / dev->nChunksPerBlock;
3119         page = chunkId % dev->nChunksPerBlock;
3120         
3121         bi = yaffs_GetBlockInfo(dev,block);
3122         
3123         T(YAFFS_TRACE_DELETION,(TSTR("line %d delete of chunk %d" TENDSTR),lyn,chunkId));
3124         
3125         if(markNAND && 
3126           bi->blockState != YAFFS_BLOCK_STATE_COLLECTING &&
3127           !dev->isYaffs2)
3128         {
3129 //              yaffs_SpareInitialise(&spare);
3130
3131 #ifdef CONFIG_MTD_NAND_VERIFY_WRITE
3132
3133                 //read data before write, to ensure correct ecc 
3134                 //if we're using MTD verification under Linux
3135                 yaffs_ReadChunkFromNAND(dev,chunkId,NULL,&spare,0);
3136 #endif
3137
3138                 yaffs_InitialiseTags(&tags);
3139
3140                 tags.chunkDeleted = 1;
3141
3142         
3143                 yaffs_WriteChunkWithTagsToNAND(dev,chunkId,NULL,&tags);
3144                 yaffs_HandleUpdateChunk(dev,chunkId,&tags);
3145         }
3146         else
3147         {
3148                         dev->nUnmarkedDeletions++;
3149         }       
3150         
3151         
3152         // Pull out of the management area.
3153         // If the whole block became dirty, this will kick off an erasure.
3154         if(     bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
3155             bi->blockState == YAFFS_BLOCK_STATE_FULL ||     
3156             bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
3157             bi->blockState == YAFFS_BLOCK_STATE_COLLECTING)
3158         {
3159                 dev->nFreeChunks++;
3160
3161                 yaffs_ClearChunkBit(dev,block,page);
3162                 
3163                 bi->pagesInUse--;
3164                 
3165                 if(bi->pagesInUse == 0 &&
3166                    !bi->hasShrinkHeader &&
3167                bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
3168                bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING)
3169             {
3170                 yaffs_BlockBecameDirty(dev,block);
3171             }
3172
3173         }
3174         else
3175         {
3176                 // T(("Bad news deleting chunk %d\n",chunkId));
3177         }
3178         
3179 }
3180
3181
3182
3183
3184 int yaffs_WriteChunkDataToObject(yaffs_Object *in,int chunkInInode, const __u8 *buffer,int nBytes,int useReserve)
3185 {
3186         // Find old chunk Need to do this to get serial number
3187         // Write new one and patch into tree.
3188         // Invalidate old tags.
3189
3190     int prevChunkId;
3191     yaffs_ExtendedTags prevTags;
3192     
3193     int newChunkId;
3194     yaffs_ExtendedTags newTags;
3195
3196     yaffs_Device *dev = in->myDev;    
3197
3198         yaffs_CheckGarbageCollection(dev);
3199
3200         // Get the previous chunk at this location in the file if it exists
3201     prevChunkId  = yaffs_FindChunkInFile(in,chunkInInode,&prevTags);
3202     
3203     // Set up new tags
3204     yaffs_InitialiseTags(&newTags);
3205     
3206         newTags.chunkId = chunkInInode;
3207         newTags.objectId = in->objectId;
3208         newTags.serialNumber = (prevChunkId >= 0) ? prevTags.serialNumber + 1 : 1;
3209         newTags.byteCount = nBytes;
3210                 
3211 //      yaffs_CalcTagsECC(&newTags);
3212
3213         newChunkId = yaffs_WriteNewChunkWithTagsToNAND(dev,buffer,&newTags,useReserve);
3214         
3215         if(newChunkId >= 0)
3216         {
3217                 yaffs_PutChunkIntoFile(in,chunkInInode,newChunkId,0);
3218                 
3219                 
3220                 if(prevChunkId >= 0)
3221                 {
3222                         yaffs_DeleteChunk(dev,prevChunkId,1,__LINE__);
3223         
3224                 }
3225                 
3226                 yaffs_CheckFileSanity(in);
3227         }
3228         return newChunkId;
3229
3230
3231
3232
3233
3234 }
3235
3236
3237 // UpdateObjectHeader updates the header on NAND for an object.
3238 // If name is not NULL, then that new name is used.
3239 //
3240 int yaffs_UpdateObjectHeader(yaffs_Object *in,const YCHAR *name, int force,int isShrink)
3241 {
3242
3243         yaffs_BlockInfo *bi;
3244         
3245         yaffs_Device *dev = in->myDev;
3246         
3247     int prevChunkId;
3248     int retVal = 0;
3249     
3250     int newChunkId;
3251     yaffs_ExtendedTags newTags;
3252     
3253     __u8 *buffer = NULL;
3254     YCHAR oldName[YAFFS_MAX_NAME_LENGTH+1];
3255     
3256    // __u8 bufferOld[YAFFS_BYTES_PER_CHUNK];
3257     
3258     yaffs_ObjectHeader *oh = NULL;
3259     // yaffs_ObjectHeader *ohOld = (yaffs_ObjectHeader *)bufferOld;
3260
3261     
3262     if(!in->fake || force)
3263     {
3264   
3265                 yaffs_CheckGarbageCollection(dev);              
3266     
3267             buffer = yaffs_GetTempBuffer(in->myDev,__LINE__);
3268             oh  = (yaffs_ObjectHeader *)buffer;
3269     
3270                 prevChunkId = in->chunkId;
3271     
3272                 if(prevChunkId >= 0)
3273                 {
3274                         yaffs_ReadChunkWithTagsFromNAND(dev,prevChunkId,buffer,NULL);
3275                         memcpy(oldName,oh->name,sizeof(oh->name));      
3276                 }
3277
3278                 memset(buffer,0xFF,dev->nBytesPerChunk);
3279
3280                 // Header data
3281                 oh->type = in->variantType;
3282                 
3283                 oh->yst_mode = in->yst_mode;
3284
3285 #ifdef CONFIG_YAFFS_WINCE
3286                 oh->win_atime[0] = in->win_atime[0];
3287                 oh->win_ctime[0] = in->win_ctime[0];
3288                 oh->win_mtime[0] = in->win_mtime[0];
3289                 oh->win_atime[1] = in->win_atime[1];
3290                 oh->win_ctime[1] = in->win_ctime[1];
3291                 oh->win_mtime[1] = in->win_mtime[1];
3292 #else
3293                 oh->yst_uid = in->yst_uid;
3294                 oh->yst_gid = in->yst_gid;
3295                 oh->yst_atime = in->yst_atime;
3296                 oh->yst_mtime = in->yst_mtime;
3297                 oh->yst_ctime = in->yst_ctime;
3298                 oh->yst_rdev = in->yst_rdev;
3299 #endif  
3300                 if(in->parent)
3301                 {
3302                         oh->parentObjectId = in->parent->objectId;
3303                 }
3304                 else
3305                 {
3306                         oh->parentObjectId = 0;
3307                 }
3308                 
3309                 //oh->sum = in->sum;
3310                 if(name && *name)
3311                 {
3312                         memset(oh->name,0,sizeof(oh->name));
3313                         yaffs_strncpy(oh->name,name,YAFFS_MAX_NAME_LENGTH);
3314                 }
3315                 else if(prevChunkId)
3316                 {       
3317                         memcpy(oh->name, oldName,sizeof(oh->name));
3318                 }
3319                 else
3320                 {
3321                         memset(oh->name,0,sizeof(oh->name));    
3322                 }
3323                 
3324                 oh->isShrink = isShrink;
3325         
3326                 switch(in->variantType)
3327                 {
3328                         case YAFFS_OBJECT_TYPE_UNKNOWN:         
3329                                 // Should not happen
3330                                 break;
3331                         case YAFFS_OBJECT_TYPE_FILE:
3332                                 oh->fileSize = (oh->parentObjectId == YAFFS_OBJECTID_DELETED ||
3333                                                 oh->parentObjectId == YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.fileVariant.fileSize;
3334                                 break;
3335                         case YAFFS_OBJECT_TYPE_HARDLINK:
3336                                 oh->equivalentObjectId = in->variant.hardLinkVariant.equivalentObjectId;
3337                                 break;
3338                         case YAFFS_OBJECT_TYPE_SPECIAL: 
3339                                 // Do nothing
3340                                 break;
3341                         case YAFFS_OBJECT_TYPE_DIRECTORY:       
3342                                 // Do nothing
3343                                 break;
3344                         case YAFFS_OBJECT_TYPE_SYMLINK:
3345                                 yaffs_strncpy(oh->alias,in->variant.symLinkVariant.alias,YAFFS_MAX_ALIAS_LENGTH);
3346                                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3347                                 break;
3348                 }
3349
3350                 // Tags
3351                 yaffs_InitialiseTags(&newTags);
3352                 in->serial++;
3353                 newTags.chunkId = 0;
3354                 newTags.objectId = in->objectId;
3355                 newTags.serialNumber = in->serial;
3356                 
3357                 // Add extra info for file header
3358                 
3359                 newTags.extraHeaderInfoAvailable = 1;
3360                 newTags.extraParentObjectId = oh->parentObjectId;
3361                 newTags.extraFileLength = oh->fileSize;
3362                 newTags.extraIsShrinkHeader = oh->isShrink;
3363                 newTags.extraEquivalentObjectId = oh->equivalentObjectId;
3364                 newTags.extraObjectType  = in->variantType;
3365                 
3366                 // Create new chunk in NAND
3367                 newChunkId = yaffs_WriteNewChunkWithTagsToNAND(dev,buffer,&newTags, (prevChunkId >= 0) ? 1 : 0 );
3368     
3369                 if(newChunkId >= 0)
3370                 {
3371                 
3372                         in->chunkId = newChunkId;       
3373                 
3374                         if(prevChunkId >= 0)
3375                         {
3376                                 yaffs_DeleteChunk(dev,prevChunkId,1,__LINE__);
3377                         }
3378                 
3379                         in->dirty = 0;
3380                         
3381                         // If this was a shrink, then mark the block that the chunk lives on
3382                         if(isShrink)
3383                         {
3384                                 bi = yaffs_GetBlockInfo(in->myDev,newChunkId / in->myDev->nChunksPerBlock);
3385                                 bi->hasShrinkHeader = 1;
3386                         }
3387                         
3388                 }
3389                 
3390                 retVal =  newChunkId;
3391
3392     }
3393     
3394         if(buffer) 
3395                 yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
3396         
3397     return retVal;
3398 }
3399
3400
3401 /////////////////////// Short Operations Cache ////////////////////////////////
3402 //      In many siturations where there is no high level buffering (eg WinCE) a lot of
3403 //      reads might be short sequential reads, and a lot of writes may be short 
3404 //  sequential writes. eg. scanning/writing a jpeg file.
3405 //      In these cases, a short read/write cache can provide a huge perfomance benefit 
3406 //  with dumb-as-a-rock code.
3407 //  There are a limited number (~10) of cache chunks per device so that we don't
3408 //  need a very intelligent search.
3409
3410
3411
3412
3413
3414 static void yaffs_FlushFilesChunkCache(yaffs_Object *obj)
3415 {
3416         yaffs_Device *dev = obj->myDev;
3417         int lowest;
3418         int i;
3419         yaffs_ChunkCache *cache;
3420         int chunkWritten = 0;
3421         //int nBytes;
3422         int nCaches = obj->myDev->nShortOpCaches;
3423         
3424         if  (nCaches > 0)
3425         {
3426                 do{
3427                         cache = NULL;
3428                 
3429                         // Find the dirty cache for this object with the lowest chunk id.
3430                         for(i = 0; i < nCaches; i++)
3431                         {
3432                                 if(dev->srCache[i].object == obj &&
3433                                    dev->srCache[i].dirty)
3434                                 {
3435                                         if(!cache ||  dev->srCache[i].chunkId < lowest)
3436                                         {
3437                                                 cache = &dev->srCache[i];
3438                                                 lowest = cache->chunkId;
3439                                         }
3440                                 }
3441                         }
3442                 
3443                         if(cache && !cache->locked)
3444                         {
3445                                 //Write it out and free it up
3446
3447 #if 0
3448                                 nBytes = cache->object->variant.fileVariant.fileSize - ((cache->chunkId -1) * YAFFS_BYTES_PER_CHUNK);
3449                         
3450                                 if(nBytes > YAFFS_BYTES_PER_CHUNK)
3451                                 {
3452<