e5b1eaf185dd410014dde4b69bf04aceb68585c7
[yaffs2.git] / yaffs_guts.c
1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2007 Aleph One Ltd.
5  *   for Toby Churchill Ltd and Brightstar Engineering
6  *
7  * Created by Charles Manning <charles@aleph1.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 const char *yaffs_guts_c_version =
15     "$Id: yaffs_guts.c,v 1.115 2010-03-07 23:43:34 charles Exp $";
16
17 #include "yportenv.h"
18 #include "yaffs_trace.h"
19
20 #include "yaffsinterface.h"
21 #include "yaffs_guts.h"
22 #include "yaffs_tagsvalidity.h"
23 #include "yaffs_getblockinfo.h"
24
25 #include "yaffs_tagscompat.h"
26 #ifndef CONFIG_YAFFS_USE_OWN_SORT
27 #include "yaffs_qsort.h"
28 #endif
29 #include "yaffs_nand.h"
30
31 #include "yaffs_checkptrw.h"
32
33 #include "yaffs_nand.h"
34 #include "yaffs_packedtags2.h"
35
36
37 #define YAFFS_PASSIVE_GC_CHUNKS 2
38
39 #include "yaffs_ecc.h"
40
41
42 /* Robustification (if it ever comes about...) */
43 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND);
44 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
45                 int erasedOk);
46 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
47                                 const __u8 *data,
48                                 const yaffs_ExtendedTags *tags);
49 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
50                                 const yaffs_ExtendedTags *tags);
51
52 /* Other local prototypes */
53 static void yaffs_UpdateParent(yaffs_Object *obj);
54 static int yaffs_UnlinkObject(yaffs_Object *obj);
55 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);
56
57 static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList);
58
59 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev,
60                                         const __u8 *buffer,
61                                         yaffs_ExtendedTags *tags,
62                                         int useReserve);
63 static int yaffs_PutChunkIntoFile(yaffs_Object *in, int chunkInInode,
64                                 int chunkInNAND, int inScan);
65
66 static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
67                                         yaffs_ObjectType type);
68 static void yaffs_AddObjectToDirectory(yaffs_Object *directory,
69                                 yaffs_Object *obj);
70 static int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name,
71                                 int force, int isShrink, int shadows);
72 static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
73 static int yaffs_CheckStructures(void);
74 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
75                         int chunkOffset, int *limit);
76 static int yaffs_DoGenericObjectDeletion(yaffs_Object *in);
77
78 static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device *dev, int blockNo);
79
80
81 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
82                                 int chunkInNAND);
83
84 static int yaffs_UnlinkWorker(yaffs_Object *obj);
85
86 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
87                         int chunkInObject);
88
89 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
90                                 yaffs_BlockInfo **blockUsedPtr);
91
92 static void yaffs_VerifyFreeChunks(yaffs_Device *dev);
93
94 static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
95
96 static void yaffs_VerifyDirectory(yaffs_Object *directory);
97 #ifdef YAFFS_PARANOID
98 static int yaffs_CheckFileSanity(yaffs_Object *in);
99 #else
100 #define yaffs_CheckFileSanity(in)
101 #endif
102
103 static void yaffs_InvalidateWholeChunkCache(yaffs_Object *in);
104 static void yaffs_InvalidateChunkCache(yaffs_Object *object, int chunkId);
105
106 static void yaffs_InvalidateCheckpoint(yaffs_Device *dev);
107
108 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
109                                 yaffs_ExtendedTags *tags);
110
111 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn,
112                 unsigned pos);
113 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,
114                                         yaffs_FileStructure *fStruct,
115                                         __u32 chunkId);
116
117 static void yaffs_SkipRestOfBlock(yaffs_Device *dev);
118 static int yaffs_VerifyChunkWritten(yaffs_Device *dev,
119                                         int chunkInNAND,
120                                         const __u8 *data,
121                                         yaffs_ExtendedTags *tags);
122
123 /* Function to calculate chunk and offset */
124
125 static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, int *chunkOut,
126                 __u32 *offsetOut)
127 {
128         int chunk;
129         __u32 offset;
130
131         chunk  = (__u32)(addr >> dev->chunkShift);
132
133         if (dev->chunkDiv == 1) {
134                 /* easy power of 2 case */
135                 offset = (__u32)(addr & dev->chunkMask);
136         } else {
137                 /* Non power-of-2 case */
138
139                 loff_t chunkBase;
140
141                 chunk /= dev->chunkDiv;
142
143                 chunkBase = ((loff_t)chunk) * dev->nDataBytesPerChunk;
144                 offset = (__u32)(addr - chunkBase);
145         }
146
147         *chunkOut = chunk;
148         *offsetOut = offset;
149 }
150
151 /* Function to return the number of shifts for a power of 2 greater than or
152  * equal to the given number
153  * Note we don't try to cater for all possible numbers and this does not have to
154  * be hellishly efficient.
155  */
156
157 static __u32 ShiftsGE(__u32 x)
158 {
159         int extraBits;
160         int nShifts;
161
162         nShifts = extraBits = 0;
163
164         while (x > 1) {
165                 if (x & 1)
166                         extraBits++;
167                 x >>= 1;
168                 nShifts++;
169         }
170
171         if (extraBits)
172                 nShifts++;
173
174         return nShifts;
175 }
176
177 /* Function to return the number of shifts to get a 1 in bit 0
178  */
179
180 static __u32 Shifts(__u32 x)
181 {
182         int nShifts;
183
184         nShifts =  0;
185
186         if (!x)
187                 return 0;
188
189         while (!(x&1)) {
190                 x >>= 1;
191                 nShifts++;
192         }
193
194         return nShifts;
195 }
196
197
198
199 /*
200  * Temporary buffer manipulations.
201  */
202
203 static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)
204 {
205         int i;
206         __u8 *buf = (__u8 *)1;
207
208         memset(dev->tempBuffer, 0, sizeof(dev->tempBuffer));
209
210         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
211                 dev->tempBuffer[i].line = 0;    /* not in use */
212                 dev->tempBuffer[i].buffer = buf =
213                     YMALLOC_DMA(dev->param.totalBytesPerChunk);
214         }
215
216         return buf ? YAFFS_OK : YAFFS_FAIL;
217 }
218
219 __u8 *yaffs_GetTempBuffer(yaffs_Device *dev, int lineNo)
220 {
221         int i, j;
222
223         dev->tempInUse++;
224         if (dev->tempInUse > dev->maxTemp)
225                 dev->maxTemp = dev->tempInUse;
226
227         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
228                 if (dev->tempBuffer[i].line == 0) {
229                         dev->tempBuffer[i].line = lineNo;
230                         if ((i + 1) > dev->maxTemp) {
231                                 dev->maxTemp = i + 1;
232                                 for (j = 0; j <= i; j++)
233                                         dev->tempBuffer[j].maxLine =
234                                             dev->tempBuffer[j].line;
235                         }
236
237                         return dev->tempBuffer[i].buffer;
238                 }
239         }
240
241         T(YAFFS_TRACE_BUFFERS,
242           (TSTR("Out of temp buffers at line %d, other held by lines:"),
243            lineNo));
244         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
245                 T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
246
247         T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
248
249         /*
250          * If we got here then we have to allocate an unmanaged one
251          * This is not good.
252          */
253
254         dev->unmanagedTempAllocations++;
255         return YMALLOC(dev->nDataBytesPerChunk);
256
257 }
258
259 void yaffs_ReleaseTempBuffer(yaffs_Device *dev, __u8 *buffer,
260                                     int lineNo)
261 {
262         int i;
263
264         dev->tempInUse--;
265
266         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
267                 if (dev->tempBuffer[i].buffer == buffer) {
268                         dev->tempBuffer[i].line = 0;
269                         return;
270                 }
271         }
272
273         if (buffer) {
274                 /* assume it is an unmanaged one. */
275                 T(YAFFS_TRACE_BUFFERS,
276                   (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
277                    lineNo));
278                 YFREE(buffer);
279                 dev->unmanagedTempDeallocations++;
280         }
281
282 }
283
284 /*
285  * Determine if we have a managed buffer.
286  */
287 int yaffs_IsManagedTempBuffer(yaffs_Device *dev, const __u8 *buffer)
288 {
289         int i;
290
291         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
292                 if (dev->tempBuffer[i].buffer == buffer)
293                         return 1;
294         }
295
296         for (i = 0; i < dev->param.nShortOpCaches; i++) {
297                 if (dev->srCache[i].data == buffer)
298                         return 1;
299         }
300
301         if (buffer == dev->checkpointBuffer)
302                 return 1;
303
304         T(YAFFS_TRACE_ALWAYS,
305                 (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
306         return 0;
307 }
308
309
310
311 /*
312  * Chunk bitmap manipulations
313  */
314
315 static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device *dev, int blk)
316 {
317         if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
318                 T(YAFFS_TRACE_ERROR,
319                         (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
320                         blk));
321                 YBUG();
322         }
323         return dev->chunkBits +
324                 (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
325 }
326
327 static Y_INLINE void yaffs_VerifyChunkBitId(yaffs_Device *dev, int blk, int chunk)
328 {
329         if (blk < dev->internalStartBlock || blk > dev->internalEndBlock ||
330                         chunk < 0 || chunk >= dev->param.nChunksPerBlock) {
331                 T(YAFFS_TRACE_ERROR,
332                 (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),
333                         blk, chunk));
334                 YBUG();
335         }
336 }
337
338 static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device *dev, int blk)
339 {
340         __u8 *blkBits = yaffs_BlockBits(dev, blk);
341
342         memset(blkBits, 0, dev->chunkBitmapStride);
343 }
344
345 static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device *dev, int blk, int chunk)
346 {
347         __u8 *blkBits = yaffs_BlockBits(dev, blk);
348
349         yaffs_VerifyChunkBitId(dev, blk, chunk);
350
351         blkBits[chunk / 8] &= ~(1 << (chunk & 7));
352 }
353
354 static Y_INLINE void yaffs_SetChunkBit(yaffs_Device *dev, int blk, int chunk)
355 {
356         __u8 *blkBits = yaffs_BlockBits(dev, blk);
357
358         yaffs_VerifyChunkBitId(dev, blk, chunk);
359
360         blkBits[chunk / 8] |= (1 << (chunk & 7));
361 }
362
363 static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device *dev, int blk, int chunk)
364 {
365         __u8 *blkBits = yaffs_BlockBits(dev, blk);
366         yaffs_VerifyChunkBitId(dev, blk, chunk);
367
368         return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
369 }
370
371 static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device *dev, int blk)
372 {
373         __u8 *blkBits = yaffs_BlockBits(dev, blk);
374         int i;
375         for (i = 0; i < dev->chunkBitmapStride; i++) {
376                 if (*blkBits)
377                         return 1;
378                 blkBits++;
379         }
380         return 0;
381 }
382
383 static int yaffs_CountChunkBits(yaffs_Device *dev, int blk)
384 {
385         __u8 *blkBits = yaffs_BlockBits(dev, blk);
386         int i;
387         int n = 0;
388         for (i = 0; i < dev->chunkBitmapStride; i++) {
389                 __u8 x = *blkBits;
390                 while (x) {
391                         if (x & 1)
392                                 n++;
393                         x >>= 1;
394                 }
395
396                 blkBits++;
397         }
398         return n;
399 }
400
401 /*
402  * Verification code
403  */
404
405 static int yaffs_SkipVerification(yaffs_Device *dev)
406 {
407         dev=dev;
408         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
409 }
410
411 static int yaffs_SkipFullVerification(yaffs_Device *dev)
412 {
413         dev=dev;
414         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_FULL));
415 }
416
417 static int yaffs_SkipNANDVerification(yaffs_Device *dev)
418 {
419         dev=dev;
420         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_NAND));
421 }
422
423 static const char *blockStateName[] = {
424 "Unknown",
425 "Needs scanning",
426 "Scanning",
427 "Empty",
428 "Allocating",
429 "Full",
430 "Dirty",
431 "Checkpoint",
432 "Collecting",
433 "Dead"
434 };
435
436 static void yaffs_VerifyBlock(yaffs_Device *dev, yaffs_BlockInfo *bi, int n)
437 {
438         int actuallyUsed;
439         int inUse;
440
441         if (yaffs_SkipVerification(dev))
442                 return;
443
444         /* Report illegal runtime states */
445         if (bi->blockState >= YAFFS_NUMBER_OF_BLOCK_STATES)
446                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has undefined state %d"TENDSTR), n, bi->blockState));
447
448         switch (bi->blockState) {
449         case YAFFS_BLOCK_STATE_UNKNOWN:
450         case YAFFS_BLOCK_STATE_SCANNING:
451         case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
452                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has bad run-state %s"TENDSTR),
453                 n, blockStateName[bi->blockState]));
454         }
455
456         /* Check pages in use and soft deletions are legal */
457
458         actuallyUsed = bi->pagesInUse - bi->softDeletions;
459
460         if (bi->pagesInUse < 0 || bi->pagesInUse > dev->param.nChunksPerBlock ||
461            bi->softDeletions < 0 || bi->softDeletions > dev->param.nChunksPerBlock ||
462            actuallyUsed < 0 || actuallyUsed > dev->param.nChunksPerBlock)
463                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has illegal values pagesInUsed %d softDeletions %d"TENDSTR),
464                 n, bi->pagesInUse, bi->softDeletions));
465
466
467         /* Check chunk bitmap legal */
468         inUse = yaffs_CountChunkBits(dev, n);
469         if (inUse != bi->pagesInUse)
470                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has inconsistent values pagesInUse %d counted chunk bits %d"TENDSTR),
471                         n, bi->pagesInUse, inUse));
472
473         /* Check that the sequence number is valid.
474          * Ten million is legal, but is very unlikely
475          */
476         if (dev->param.isYaffs2 &&
477            (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING || bi->blockState == YAFFS_BLOCK_STATE_FULL) &&
478            (bi->sequenceNumber < YAFFS_LOWEST_SEQUENCE_NUMBER || bi->sequenceNumber > 10000000))
479                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has suspect sequence number of %d"TENDSTR),
480                 n, bi->sequenceNumber));
481 }
482
483 static void yaffs_VerifyCollectedBlock(yaffs_Device *dev, yaffs_BlockInfo *bi,
484                 int n)
485 {
486         yaffs_VerifyBlock(dev, bi, n);
487
488         /* After collection the block should be in the erased state */
489         /* This will need to change if we do partial gc */
490
491         if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING &&
492                         bi->blockState != YAFFS_BLOCK_STATE_EMPTY) {
493                 T(YAFFS_TRACE_ERROR, (TSTR("Block %d is in state %d after gc, should be erased"TENDSTR),
494                         n, bi->blockState));
495         }
496 }
497
498 static void yaffs_VerifyBlocks(yaffs_Device *dev)
499 {
500         int i;
501         int nBlocksPerState[YAFFS_NUMBER_OF_BLOCK_STATES];
502         int nIllegalBlockStates = 0;
503
504         if (yaffs_SkipVerification(dev))
505                 return;
506
507         memset(nBlocksPerState, 0, sizeof(nBlocksPerState));
508
509         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
510                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, i);
511                 yaffs_VerifyBlock(dev, bi, i);
512
513                 if (bi->blockState < YAFFS_NUMBER_OF_BLOCK_STATES)
514                         nBlocksPerState[bi->blockState]++;
515                 else
516                         nIllegalBlockStates++;
517         }
518
519         T(YAFFS_TRACE_VERIFY, (TSTR(""TENDSTR)));
520         T(YAFFS_TRACE_VERIFY, (TSTR("Block summary"TENDSTR)));
521
522         T(YAFFS_TRACE_VERIFY, (TSTR("%d blocks have illegal states"TENDSTR), nIllegalBlockStates));
523         if (nBlocksPerState[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
524                 T(YAFFS_TRACE_VERIFY, (TSTR("Too many allocating blocks"TENDSTR)));
525
526         for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
527                 T(YAFFS_TRACE_VERIFY,
528                   (TSTR("%s %d blocks"TENDSTR),
529                   blockStateName[i], nBlocksPerState[i]));
530
531         if (dev->blocksInCheckpoint != nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT])
532                 T(YAFFS_TRACE_VERIFY,
533                  (TSTR("Checkpoint block count wrong dev %d count %d"TENDSTR),
534                  dev->blocksInCheckpoint, nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT]));
535
536         if (dev->nErasedBlocks != nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY])
537                 T(YAFFS_TRACE_VERIFY,
538                  (TSTR("Erased block count wrong dev %d count %d"TENDSTR),
539                  dev->nErasedBlocks, nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY]));
540
541         if (nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
542                 T(YAFFS_TRACE_VERIFY,
543                  (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
544                  nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));
545
546         T(YAFFS_TRACE_VERIFY, (TSTR(""TENDSTR)));
547
548 }
549
550 /*
551  * Verify the object header. oh must be valid, but obj and tags may be NULL in which
552  * case those tests will not be performed.
553  */
554 static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
555 {
556         if (obj && yaffs_SkipVerification(obj->myDev))
557                 return;
558
559         if (!(tags && obj && oh)) {
560                 T(YAFFS_TRACE_VERIFY,
561                                 (TSTR("Verifying object header tags %p obj %p oh %p"TENDSTR),
562                                 tags, obj, oh));
563                 return;
564         }
565
566         if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
567                         oh->type > YAFFS_OBJECT_TYPE_MAX)
568                 T(YAFFS_TRACE_VERIFY,
569                         (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
570                         tags->objectId, oh->type));
571
572         if (tags->objectId != obj->objectId)
573                 T(YAFFS_TRACE_VERIFY,
574                         (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
575                         tags->objectId, obj->objectId));
576
577
578         /*
579          * Check that the object's parent ids match if parentCheck requested.
580          *
581          * Tests do not apply to the root object.
582          */
583
584         if (parentCheck && tags->objectId > 1 && !obj->parent)
585                 T(YAFFS_TRACE_VERIFY,
586                         (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
587                         tags->objectId, oh->parentObjectId));
588
589         if (parentCheck && obj->parent &&
590                         oh->parentObjectId != obj->parent->objectId &&
591                         (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
592                         obj->parent->objectId != YAFFS_OBJECTID_DELETED))
593                 T(YAFFS_TRACE_VERIFY,
594                         (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
595                         tags->objectId, oh->parentObjectId, obj->parent->objectId));
596
597         if (tags->objectId > 1 && oh->name[0] == 0) /* Null name */
598                 T(YAFFS_TRACE_VERIFY,
599                         (TSTR("Obj %d header name is NULL"TENDSTR),
600                         obj->objectId));
601
602         if (tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
603                 T(YAFFS_TRACE_VERIFY,
604                         (TSTR("Obj %d header name is 0xFF"TENDSTR),
605                         obj->objectId));
606 }
607
608
609
610 static int yaffs_VerifyTnodeWorker(yaffs_Object *obj, yaffs_Tnode *tn,
611                                         __u32 level, int chunkOffset)
612 {
613         int i;
614         yaffs_Device *dev = obj->myDev;
615         int ok = 1;
616
617         if (tn) {
618                 if (level > 0) {
619
620                         for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
621                                 if (tn->internal[i]) {
622                                         ok = yaffs_VerifyTnodeWorker(obj,
623                                                         tn->internal[i],
624                                                         level - 1,
625                                                         (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
626                                 }
627                         }
628                 } else if (level == 0) {
629                         yaffs_ExtendedTags tags;
630                         __u32 objectId = obj->objectId;
631
632                         chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
633
634                         for (i = 0; i < YAFFS_NTNODES_LEVEL0; i++) {
635                                 __u32 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
636
637                                 if (theChunk > 0) {
638                                         /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
639                                         yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL, &tags);
640                                         if (tags.objectId != objectId || tags.chunkId != chunkOffset) {
641                                                 T(~0, (TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
642                                                         objectId, chunkOffset, theChunk,
643                                                         tags.objectId, tags.chunkId));
644                                         }
645                                 }
646                                 chunkOffset++;
647                         }
648                 }
649         }
650
651         return ok;
652
653 }
654
655
656 static void yaffs_VerifyFile(yaffs_Object *obj)
657 {
658         int requiredTallness;
659         int actualTallness;
660         __u32 lastChunk;
661         __u32 x;
662         __u32 i;
663         yaffs_Device *dev;
664         yaffs_ExtendedTags tags;
665         yaffs_Tnode *tn;
666         __u32 objectId;
667
668         if (!obj)
669                 return;
670
671         if (yaffs_SkipVerification(obj->myDev))
672                 return;
673
674         dev = obj->myDev;
675         objectId = obj->objectId;
676
677         /* Check file size is consistent with tnode depth */
678         lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
679         x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
680         requiredTallness = 0;
681         while (x > 0) {
682                 x >>= YAFFS_TNODES_INTERNAL_BITS;
683                 requiredTallness++;
684         }
685
686         actualTallness = obj->variant.fileVariant.topLevel;
687
688         /* Check that the chunks in the tnode tree are all correct.
689          * We do this by scanning through the tnode tree and
690          * checking the tags for every chunk match.
691          */
692
693         if (yaffs_SkipNANDVerification(dev))
694                 return;
695
696         for (i = 1; i <= lastChunk; i++) {
697                 tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant, i);
698
699                 if (tn) {
700                         __u32 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
701                         if (theChunk > 0) {
702                                 /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
703                                 yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL, &tags);
704                                 if (tags.objectId != objectId || tags.chunkId != i) {
705                                         T(~0, (TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
706                                                 objectId, i, theChunk,
707                                                 tags.objectId, tags.chunkId));
708                                 }
709                         }
710                 }
711         }
712 }
713
714
715 static void yaffs_VerifyHardLink(yaffs_Object *obj)
716 {
717         if (obj && yaffs_SkipVerification(obj->myDev))
718                 return;
719
720         /* Verify sane equivalent object */
721 }
722
723 static void yaffs_VerifySymlink(yaffs_Object *obj)
724 {
725         if (obj && yaffs_SkipVerification(obj->myDev))
726                 return;
727
728         /* Verify symlink string */
729 }
730
731 static void yaffs_VerifySpecial(yaffs_Object *obj)
732 {
733         if (obj && yaffs_SkipVerification(obj->myDev))
734                 return;
735 }
736
737 static void yaffs_VerifyObject(yaffs_Object *obj)
738 {
739         yaffs_Device *dev;
740
741         __u32 chunkMin;
742         __u32 chunkMax;
743
744         __u32 chunkIdOk;
745         __u32 chunkInRange;
746         __u32 chunkShouldNotBeDeleted;
747         __u32 chunkValid;
748
749         if (!obj)
750                 return;
751
752         if (obj->beingCreated)
753                 return;
754
755         dev = obj->myDev;
756
757         if (yaffs_SkipVerification(dev))
758                 return;
759
760         /* Check sane object header chunk */
761
762         chunkMin = dev->internalStartBlock * dev->param.nChunksPerBlock;
763         chunkMax = (dev->internalEndBlock+1) * dev->param.nChunksPerBlock - 1;
764
765         chunkInRange = (((unsigned)(obj->hdrChunk)) >= chunkMin && ((unsigned)(obj->hdrChunk)) <= chunkMax);
766         chunkIdOk = chunkInRange || (obj->hdrChunk == 0);
767         chunkValid = chunkInRange &&
768                         yaffs_CheckChunkBit(dev,
769                                         obj->hdrChunk / dev->param.nChunksPerBlock,
770                                         obj->hdrChunk % dev->param.nChunksPerBlock);
771         chunkShouldNotBeDeleted = chunkInRange && !chunkValid;
772
773         if (!obj->fake &&
774                         (!chunkIdOk || chunkShouldNotBeDeleted)) {
775                 T(YAFFS_TRACE_VERIFY,
776                         (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
777                         obj->objectId, obj->hdrChunk,
778                         chunkIdOk ? "" : ",out of range",
779                         chunkShouldNotBeDeleted ? ",marked as deleted" : ""));
780         }
781
782         if (chunkValid && !yaffs_SkipNANDVerification(dev)) {
783                 yaffs_ExtendedTags tags;
784                 yaffs_ObjectHeader *oh;
785                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
786
787                 oh = (yaffs_ObjectHeader *)buffer;
788
789                 yaffs_ReadChunkWithTagsFromNAND(dev, obj->hdrChunk, buffer,
790                                 &tags);
791
792                 yaffs_VerifyObjectHeader(obj, oh, &tags, 1);
793
794                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
795         }
796
797         /* Verify it has a parent */
798         if (obj && !obj->fake &&
799                         (!obj->parent || obj->parent->myDev != dev)) {
800                 T(YAFFS_TRACE_VERIFY,
801                         (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
802                         obj->objectId, obj->parent));
803         }
804
805         /* Verify parent is a directory */
806         if (obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
807                 T(YAFFS_TRACE_VERIFY,
808                         (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
809                         obj->objectId, obj->parent->variantType));
810         }
811
812         switch (obj->variantType) {
813         case YAFFS_OBJECT_TYPE_FILE:
814                 yaffs_VerifyFile(obj);
815                 break;
816         case YAFFS_OBJECT_TYPE_SYMLINK:
817                 yaffs_VerifySymlink(obj);
818                 break;
819         case YAFFS_OBJECT_TYPE_DIRECTORY:
820                 yaffs_VerifyDirectory(obj);
821                 break;
822         case YAFFS_OBJECT_TYPE_HARDLINK:
823                 yaffs_VerifyHardLink(obj);
824                 break;
825         case YAFFS_OBJECT_TYPE_SPECIAL:
826                 yaffs_VerifySpecial(obj);
827                 break;
828         case YAFFS_OBJECT_TYPE_UNKNOWN:
829         default:
830                 T(YAFFS_TRACE_VERIFY,
831                 (TSTR("Obj %d has illegaltype %d"TENDSTR),
832                 obj->objectId, obj->variantType));
833                 break;
834         }
835 }
836
837 static void yaffs_VerifyObjects(yaffs_Device *dev)
838 {
839         yaffs_Object *obj;
840         int i;
841         struct ylist_head *lh;
842
843         if (yaffs_SkipVerification(dev))
844                 return;
845
846         /* Iterate through the objects in each hash entry */
847
848         for (i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++) {
849                 ylist_for_each(lh, &dev->objectBucket[i].list) {
850                         if (lh) {
851                                 obj = ylist_entry(lh, yaffs_Object, hashLink);
852                                 yaffs_VerifyObject(obj);
853                         }
854                 }
855         }
856 }
857
858
859 /*
860  *  Simple hash function. Needs to have a reasonable spread
861  */
862
863 static Y_INLINE int yaffs_HashFunction(int n)
864 {
865         n = abs(n);
866         return n % YAFFS_NOBJECT_BUCKETS;
867 }
868
869 /*
870  * Access functions to useful fake objects.
871  * Note that root might have a presence in NAND if permissions are set.
872  */
873
874 yaffs_Object *yaffs_Root(yaffs_Device *dev)
875 {
876         return dev->rootDir;
877 }
878
879 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev)
880 {
881         return dev->lostNFoundDir;
882 }
883
884
885 /*
886  *  Erased NAND checking functions
887  */
888
889 int yaffs_CheckFF(__u8 *buffer, int nBytes)
890 {
891         /* Horrible, slow implementation */
892         while (nBytes--) {
893                 if (*buffer != 0xFF)
894                         return 0;
895                 buffer++;
896         }
897         return 1;
898 }
899
900 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
901                                 int chunkInNAND)
902 {
903         int retval = YAFFS_OK;
904         __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
905         yaffs_ExtendedTags tags;
906         int result;
907
908         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
909
910         if (tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
911                 retval = YAFFS_FAIL;
912
913         if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
914                 T(YAFFS_TRACE_NANDACCESS,
915                   (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
916                 retval = YAFFS_FAIL;
917         }
918
919         yaffs_ReleaseTempBuffer(dev, data, __LINE__);
920
921         return retval;
922
923 }
924
925
926 static int yaffs_VerifyChunkWritten(yaffs_Device *dev,
927                                         int chunkInNAND,
928                                         const __u8 *data,
929                                         yaffs_ExtendedTags *tags)
930 {
931         int retval = YAFFS_OK;
932         yaffs_ExtendedTags tempTags;
933         __u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
934         int result;
935         
936         result = yaffs_ReadChunkWithTagsFromNAND(dev,chunkInNAND,buffer,&tempTags);
937         if(memcmp(buffer,data,dev->nDataBytesPerChunk) ||
938                 tempTags.objectId != tags->objectId ||
939                 tempTags.chunkId  != tags->chunkId ||
940                 tempTags.byteCount != tags->byteCount)
941                 retval = YAFFS_FAIL;
942
943         yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
944
945         return retval;
946 }
947
948 static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
949                                         const __u8 *data,
950                                         yaffs_ExtendedTags *tags,
951                                         int useReserve)
952 {
953         int attempts = 0;
954         int writeOk = 0;
955         int chunk;
956
957         yaffs_InvalidateCheckpoint(dev);
958
959         do {
960                 yaffs_BlockInfo *bi = 0;
961                 int erasedOk = 0;
962
963                 chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
964                 if (chunk < 0) {
965                         /* no space */
966                         break;
967                 }
968
969                 /* First check this chunk is erased, if it needs
970                  * checking.  The checking policy (unless forced
971                  * always on) is as follows:
972                  *
973                  * Check the first page we try to write in a block.
974                  * If the check passes then we don't need to check any
975                  * more.        If the check fails, we check again...
976                  * If the block has been erased, we don't need to check.
977                  *
978                  * However, if the block has been prioritised for gc,
979                  * then we think there might be something odd about
980                  * this block and stop using it.
981                  *
982                  * Rationale: We should only ever see chunks that have
983                  * not been erased if there was a partially written
984                  * chunk due to power loss.  This checking policy should
985                  * catch that case with very few checks and thus save a
986                  * lot of checks that are most likely not needed.
987                  *
988                  * Mods to the above
989                  * If an erase check fails or the write fails we skip the 
990                  * rest of the block.
991                  */
992
993                 /* let's give it a try */
994                 attempts++;
995
996 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
997                 bi->skipErasedCheck = 0;
998 #endif
999                 if (!bi->skipErasedCheck) {
1000                         erasedOk = yaffs_CheckChunkErased(dev, chunk);
1001                         if (erasedOk != YAFFS_OK) {
1002                                 T(YAFFS_TRACE_ERROR,
1003                                 (TSTR("**>> yaffs chunk %d was not erased"
1004                                 TENDSTR), chunk));
1005
1006                                 /* If not erased, delete this one,
1007                                  * skip rest of block and
1008                                  * try another chunk */
1009                                  yaffs_DeleteChunk(dev,chunk,1,__LINE__);
1010                                  yaffs_SkipRestOfBlock(dev);
1011                                 continue;
1012                         }
1013                 }
1014
1015                 writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
1016                                 data, tags);
1017
1018                 if(!bi->skipErasedCheck)
1019                         writeOk = yaffs_VerifyChunkWritten(dev, chunk, data, tags);
1020
1021                 if (writeOk != YAFFS_OK) {
1022                         /* Clean up aborted write, skip to next block and
1023                          * try another chunk */
1024                         yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
1025                         continue;
1026                 }
1027
1028                 bi->skipErasedCheck = 1;
1029
1030                 /* Copy the data into the robustification buffer */
1031                 yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
1032
1033         } while (writeOk != YAFFS_OK &&
1034                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
1035
1036         if (!writeOk)
1037                 chunk = -1;
1038
1039         if (attempts > 1) {
1040                 T(YAFFS_TRACE_ERROR,
1041                         (TSTR("**>> yaffs write required %d attempts" TENDSTR),
1042                         attempts));
1043
1044                 dev->nRetriedWrites += (attempts - 1);
1045         }
1046
1047         return chunk;
1048 }
1049
1050
1051 /*
1052  * Oldest Dirty Sequence Number handling.
1053  */
1054  
1055 /* yaffs_CalcOldestDirtySequence()
1056  * yaffs_FindOldestDirtySequence()
1057  * Calculate the oldest dirty sequence number if we don't know it.
1058  */
1059 static int yaffs_CalcOldestDirtySequence(yaffs_Device *dev)
1060 {
1061         int i;
1062         __u32 seq;
1063         yaffs_BlockInfo *b = 0;
1064
1065         if(!dev->param.isYaffs2)
1066                 return 0;
1067
1068         /* Find the oldest dirty sequence number. */
1069         seq = dev->sequenceNumber;
1070         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
1071                 b = yaffs_GetBlockInfo(dev, i);
1072                 if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
1073                     (b->pagesInUse - b->softDeletions) < dev->param.nChunksPerBlock &&
1074                     b->sequenceNumber < seq) 
1075                                 seq = b->sequenceNumber;
1076         }
1077         return seq;
1078 }
1079
1080
1081 static void yaffs_FindOldestDirtySequence(yaffs_Device *dev)
1082 {
1083         if(dev->param.isYaffs2 && !dev->oldestDirtySequence)
1084                 dev->oldestDirtySequence = 
1085                         yaffs_CalcOldestDirtySequence(dev);
1086
1087 #if 0
1088         if(!yaffs_SkipVerification(dev) &&
1089                 dev->oldestDirtySequence != yaffs_CalcOldestDirtySequence(dev))
1090                 YBUG();
1091
1092 #endif
1093 }
1094
1095 /*
1096  * yaffs_ClearOldestDirtySequence()
1097  * Called when a block is erased or marked bad. (ie. when its sequenceNumber
1098  * becomes invalid). If the value matches the oldest then we clear 
1099  * dev->oldestDirtySequence to force its recomputation.
1100  */
1101 static void yaffs_ClearOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *bi)
1102 {
1103
1104         if(!dev->param.isYaffs2)
1105                 return;
1106
1107         if(!bi || bi->sequenceNumber == dev->oldestDirtySequence)
1108                 dev->oldestDirtySequence = 0;
1109 }
1110
1111 /*
1112  * yaffs_UpdateOldestDirtySequence()
1113  * Update the oldest dirty sequence number whenever we dirty a block.
1114  * Only do this if the oldestDirtySequence is actually being tracked.
1115  */
1116 static void yaffs_UpdateOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *bi)
1117 {
1118         if(dev->param.isYaffs2 && dev->oldestDirtySequence){
1119                 if(dev->oldestDirtySequence > bi->sequenceNumber)
1120                         dev->oldestDirtySequence = bi->sequenceNumber;
1121         }
1122 }
1123  
1124 /*
1125  * Block retiring for handling a broken block.
1126  */
1127
1128 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND)
1129 {
1130         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1131
1132         yaffs_InvalidateCheckpoint(dev);
1133         
1134         yaffs_ClearOldestDirtySequence(dev,bi);
1135
1136         if (yaffs_MarkBlockBad(dev, blockInNAND) != YAFFS_OK) {
1137                 if (yaffs_EraseBlockInNAND(dev, blockInNAND) != YAFFS_OK) {
1138                         T(YAFFS_TRACE_ALWAYS, (TSTR(
1139                                 "yaffs: Failed to mark bad and erase block %d"
1140                                 TENDSTR), blockInNAND));
1141                 } else {
1142                         yaffs_ExtendedTags tags;
1143                         int chunkId = blockInNAND * dev->param.nChunksPerBlock;
1144
1145                         __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
1146
1147                         memset(buffer, 0xff, dev->nDataBytesPerChunk);
1148                         yaffs_InitialiseTags(&tags);
1149                         tags.sequenceNumber = YAFFS_SEQUENCE_BAD_BLOCK;
1150                         if (dev->param.writeChunkWithTagsToNAND(dev, chunkId -
1151                                 dev->chunkOffset, buffer, &tags) != YAFFS_OK)
1152                                 T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Failed to "
1153                                         TCONT("write bad block marker to block %d")
1154                                         TENDSTR), blockInNAND));
1155
1156                         yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
1157                 }
1158         }
1159
1160         bi->blockState = YAFFS_BLOCK_STATE_DEAD;
1161         bi->gcPrioritise = 0;
1162         bi->needsRetiring = 0;
1163
1164         dev->nRetiredBlocks++;
1165 }
1166
1167 /*
1168  * Functions for robustisizing TODO
1169  *
1170  */
1171
1172 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
1173                                 const __u8 *data,
1174                                 const yaffs_ExtendedTags *tags)
1175 {
1176         dev=dev;
1177         chunkInNAND=chunkInNAND;
1178         data=data;
1179         tags=tags;
1180 }
1181
1182 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
1183                                 const yaffs_ExtendedTags *tags)
1184 {
1185         dev=dev;
1186         chunkInNAND=chunkInNAND;
1187         tags=tags;
1188 }
1189
1190 void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
1191 {
1192         if (!bi->gcPrioritise) {
1193                 bi->gcPrioritise = 1;
1194                 dev->hasPendingPrioritisedGCs = 1;
1195                 bi->chunkErrorStrikes++;
1196
1197                 if (bi->chunkErrorStrikes > 3) {
1198                         bi->needsRetiring = 1; /* Too many stikes, so retire this */
1199                         T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));
1200
1201                 }
1202         }
1203 }
1204
1205 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
1206                 int erasedOk)
1207 {
1208         int blockInNAND = chunkInNAND / dev->param.nChunksPerBlock;
1209         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1210
1211         yaffs_HandleChunkError(dev, bi);
1212
1213         if (erasedOk) {
1214                 /* Was an actual write failure, so mark the block for retirement  */
1215                 bi->needsRetiring = 1;
1216                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
1217                   (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));
1218         }
1219
1220         /* Delete the chunk */
1221         yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
1222         yaffs_SkipRestOfBlock(dev);
1223 }
1224
1225
1226 /*---------------- Name handling functions ------------*/
1227
1228 static __u16 yaffs_CalcNameSum(const YCHAR *name)
1229 {
1230         __u16 sum = 0;
1231         __u16 i = 1;
1232
1233         const YUCHAR *bname = (const YUCHAR *) name;
1234         if (bname) {
1235                 while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
1236
1237 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
1238                         sum += yaffs_toupper(*bname) * i;
1239 #else
1240                         sum += (*bname) * i;
1241 #endif
1242                         i++;
1243                         bname++;
1244                 }
1245         }
1246         return sum;
1247 }
1248
1249 static void yaffs_SetObjectName(yaffs_Object *obj, const YCHAR *name)
1250 {
1251 #ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
1252         memset(obj->shortName, 0, sizeof(YCHAR) * (YAFFS_SHORT_NAME_LENGTH+1));
1253         if (name && yaffs_strnlen(name,YAFFS_SHORT_NAME_LENGTH+1) <= YAFFS_SHORT_NAME_LENGTH)
1254                 yaffs_strcpy(obj->shortName, name);
1255         else
1256                 obj->shortName[0] = _Y('\0');
1257 #endif
1258         obj->sum = yaffs_CalcNameSum(name);
1259 }
1260
1261 /*-------------------- TNODES -------------------
1262
1263  * List of spare tnodes
1264  * The list is hooked together using the first pointer
1265  * in the tnode.
1266  */
1267
1268 /* yaffs_CreateTnodes creates a bunch more tnodes and
1269  * adds them to the tnode free list.
1270  * Don't use this function directly
1271  */
1272 static Y_INLINE int yaffs_CalcTnodeSize(yaffs_Device *dev)
1273 {
1274         int tnodeSize;
1275         /* Calculate the tnode size in bytes for variable width tnode support.
1276          * Must be a multiple of 32-bits  */
1277         tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
1278
1279         if (tnodeSize < sizeof(yaffs_Tnode))
1280                 tnodeSize = sizeof(yaffs_Tnode);
1281         return tnodeSize;
1282 }
1283
1284 static int yaffs_CreateTnodes(yaffs_Device *dev, int nTnodes)
1285 {
1286         int i;
1287         int tnodeSize = yaffs_CalcTnodeSize(dev);
1288         yaffs_Tnode *newTnodes;
1289         __u8 *mem;
1290         yaffs_Tnode *curr;
1291         yaffs_Tnode *next;
1292         yaffs_TnodeList *tnl;
1293
1294         if (nTnodes < 1)
1295                 return YAFFS_OK;
1296
1297
1298         /* make these things */
1299
1300         newTnodes = YMALLOC(nTnodes * tnodeSize);
1301         mem = (__u8 *)newTnodes;
1302
1303         if (!newTnodes) {
1304                 T(YAFFS_TRACE_ERROR,
1305                         (TSTR("yaffs: Could not allocate Tnodes" TENDSTR)));
1306                 return YAFFS_FAIL;
1307         }
1308
1309         /* Hook them into the free list */
1310 #if 0
1311         for (i = 0; i < nTnodes - 1; i++) {
1312                 newTnodes[i].internal[0] = &newTnodes[i + 1];
1313 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1314                 newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1315 #endif
1316         }
1317
1318         newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
1319 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1320         newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1321 #endif
1322         dev->freeTnodes = newTnodes;
1323 #else
1324         /* New hookup for wide tnodes */
1325         for (i = 0; i < nTnodes - 1; i++) {
1326                 curr = (yaffs_Tnode *) &mem[i * tnodeSize];
1327                 next = (yaffs_Tnode *) &mem[(i+1) * tnodeSize];
1328                 curr->internal[0] = next;
1329         }
1330
1331         curr = (yaffs_Tnode *) &mem[(nTnodes - 1) * tnodeSize];
1332         curr->internal[0] = dev->freeTnodes;
1333         dev->freeTnodes = (yaffs_Tnode *)mem;
1334
1335 #endif
1336
1337
1338         dev->nFreeTnodes += nTnodes;
1339         dev->nTnodesCreated += nTnodes;
1340
1341         /* Now add this bunch of tnodes to a list for freeing up.
1342          * NB If we can't add this to the management list it isn't fatal
1343          * but it just means we can't free this bunch of tnodes later.
1344          */
1345
1346         tnl = YMALLOC(sizeof(yaffs_TnodeList));
1347         if (!tnl) {
1348                 T(YAFFS_TRACE_ERROR,
1349                   (TSTR
1350                    ("yaffs: Could not add tnodes to management list" TENDSTR)));
1351                    return YAFFS_FAIL;
1352         } else {
1353                 tnl->tnodes = newTnodes;
1354                 tnl->next = dev->allocatedTnodeList;
1355                 dev->allocatedTnodeList = tnl;
1356         }
1357
1358         T(YAFFS_TRACE_ALLOCATE, (TSTR("yaffs: Tnodes added" TENDSTR)));
1359
1360         return YAFFS_OK;
1361 }
1362
1363 /* GetTnode gets us a clean tnode. Tries to make allocate more if we run out */
1364
1365 static yaffs_Tnode *yaffs_GetTnodeRaw(yaffs_Device *dev)
1366 {
1367         yaffs_Tnode *tn = NULL;
1368
1369 #ifdef CONFIG_YAFFS_VALGRIND_TEST
1370         tn = YMALLOC(yaffs_CalcTnodeSize(dev));
1371         if(tn)
1372                 dev->nTnodesCreated++;
1373 #else
1374         /* If there are none left make more */
1375         if (!dev->freeTnodes)
1376                 yaffs_CreateTnodes(dev, YAFFS_ALLOCATION_NTNODES);
1377
1378         if (dev->freeTnodes) {
1379                 tn = dev->freeTnodes;
1380 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1381                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != (void *)1) {
1382                         /* Hoosterman, this thing looks like it isn't in the list */
1383                         T(YAFFS_TRACE_ALWAYS,
1384                           (TSTR("yaffs: Tnode list bug 1" TENDSTR)));
1385                 }
1386 #endif
1387                 dev->freeTnodes = dev->freeTnodes->internal[0];
1388                 dev->nFreeTnodes--;
1389         }
1390 #endif
1391         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1392
1393         return tn;
1394 }
1395
1396 static yaffs_Tnode *yaffs_GetTnode(yaffs_Device *dev)
1397 {
1398         yaffs_Tnode *tn = yaffs_GetTnodeRaw(dev);
1399         int tnodeSize = yaffs_CalcTnodeSize(dev);
1400
1401         if (tn)
1402                 memset(tn, 0, tnodeSize);
1403
1404         return tn;
1405 }
1406
1407 /* FreeTnode frees up a tnode and puts it back on the free list */
1408 static void yaffs_FreeTnode(yaffs_Device *dev, yaffs_Tnode *tn)
1409 {
1410         if (tn) {
1411 #ifdef CONFIG_YAFFS_VALGRIND_TEST
1412                 YFREE(tn);
1413                 dev->nTnodesCreated--;
1414 #else
1415 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1416                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != 0) {
1417                         /* Hoosterman, this thing looks like it is already in the list */
1418                         T(YAFFS_TRACE_ALWAYS,
1419                           (TSTR("yaffs: Tnode list bug 2" TENDSTR)));
1420                 }
1421                 tn->internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1422 #endif
1423                 tn->internal[0] = dev->freeTnodes;
1424                 dev->freeTnodes = tn;
1425                 dev->nFreeTnodes++;
1426 #endif
1427         }
1428         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1429 }
1430
1431 static void yaffs_DeinitialiseTnodes(yaffs_Device *dev)
1432 {
1433         /* Free the list of allocated tnodes */
1434         yaffs_TnodeList *tmp;
1435
1436         while (dev->allocatedTnodeList) {
1437                 tmp = dev->allocatedTnodeList->next;
1438
1439                 YFREE(dev->allocatedTnodeList->tnodes);
1440                 YFREE(dev->allocatedTnodeList);
1441                 dev->allocatedTnodeList = tmp;
1442
1443         }
1444
1445         dev->freeTnodes = NULL;
1446         dev->nFreeTnodes = 0;
1447         dev->nTnodesCreated = 0;
1448 }
1449
1450 static void yaffs_InitialiseTnodes(yaffs_Device *dev)
1451 {
1452         dev->allocatedTnodeList = NULL;
1453         dev->freeTnodes = NULL;
1454         dev->nFreeTnodes = 0;
1455         dev->nTnodesCreated = 0;
1456 }
1457
1458
1459 void yaffs_LoadLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos,
1460                 unsigned val)
1461 {
1462         __u32 *map = (__u32 *)tn;
1463         __u32 bitInMap;
1464         __u32 bitInWord;
1465         __u32 wordInMap;
1466         __u32 mask;
1467
1468         pos &= YAFFS_TNODES_LEVEL0_MASK;
1469         val >>= dev->chunkGroupBits;
1470
1471         bitInMap = pos * dev->tnodeWidth;
1472         wordInMap = bitInMap / 32;
1473         bitInWord = bitInMap & (32 - 1);
1474
1475         mask = dev->tnodeMask << bitInWord;
1476
1477         map[wordInMap] &= ~mask;
1478         map[wordInMap] |= (mask & (val << bitInWord));
1479
1480         if (dev->tnodeWidth > (32 - bitInWord)) {
1481                 bitInWord = (32 - bitInWord);
1482                 wordInMap++;;
1483                 mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
1484                 map[wordInMap] &= ~mask;
1485                 map[wordInMap] |= (mask & (val >> bitInWord));
1486         }
1487 }
1488
1489 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn,
1490                 unsigned pos)
1491 {
1492         __u32 *map = (__u32 *)tn;
1493         __u32 bitInMap;
1494         __u32 bitInWord;
1495         __u32 wordInMap;
1496         __u32 val;
1497
1498         pos &= YAFFS_TNODES_LEVEL0_MASK;
1499
1500         bitInMap = pos * dev->tnodeWidth;
1501         wordInMap = bitInMap / 32;
1502         bitInWord = bitInMap & (32 - 1);
1503
1504         val = map[wordInMap] >> bitInWord;
1505
1506         if      (dev->tnodeWidth > (32 - bitInWord)) {
1507                 bitInWord = (32 - bitInWord);
1508                 wordInMap++;;
1509                 val |= (map[wordInMap] << bitInWord);
1510         }
1511
1512         val &= dev->tnodeMask;
1513         val <<= dev->chunkGroupBits;
1514
1515         return val;
1516 }
1517
1518 /* ------------------- End of individual tnode manipulation -----------------*/
1519
1520 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
1521  * The look up tree is represented by the top tnode and the number of topLevel
1522  * in the tree. 0 means only the level 0 tnode is in the tree.
1523  */
1524
1525 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
1526 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,
1527                                         yaffs_FileStructure *fStruct,
1528                                         __u32 chunkId)
1529 {
1530         yaffs_Tnode *tn = fStruct->top;
1531         __u32 i;
1532         int requiredTallness;
1533         int level = fStruct->topLevel;
1534
1535         dev=dev;
1536
1537         /* Check sane level and chunk Id */
1538         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
1539                 return NULL;
1540
1541         if (chunkId > YAFFS_MAX_CHUNK_ID)
1542                 return NULL;
1543
1544         /* First check we're tall enough (ie enough topLevel) */
1545
1546         i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1547         requiredTallness = 0;
1548         while (i) {
1549                 i >>= YAFFS_TNODES_INTERNAL_BITS;
1550                 requiredTallness++;
1551         }
1552
1553         if (requiredTallness > fStruct->topLevel)
1554                 return NULL; /* Not tall enough, so we can't find it */
1555
1556         /* Traverse down to level 0 */
1557         while (level > 0 && tn) {
1558                 tn = tn->internal[(chunkId >>
1559                         (YAFFS_TNODES_LEVEL0_BITS +
1560                                 (level - 1) *
1561                                 YAFFS_TNODES_INTERNAL_BITS)) &
1562                         YAFFS_TNODES_INTERNAL_MASK];
1563                 level--;
1564         }
1565
1566         return tn;
1567 }
1568
1569 /* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
1570  * This happens in two steps:
1571  *  1. If the tree isn't tall enough, then make it taller.
1572  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
1573  *
1574  * Used when modifying the tree.
1575  *
1576  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
1577  *  be plugged into the ttree.
1578  */
1579
1580 static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device *dev,
1581                                         yaffs_FileStructure *fStruct,
1582                                         __u32 chunkId,
1583                                         yaffs_Tnode *passedTn)
1584 {
1585         int requiredTallness;
1586         int i;
1587         int l;
1588         yaffs_Tnode *tn;
1589
1590         __u32 x;
1591
1592
1593         /* Check sane level and page Id */
1594         if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL)
1595                 return NULL;
1596
1597         if (chunkId > YAFFS_MAX_CHUNK_ID)
1598                 return NULL;
1599
1600         /* First check we're tall enough (ie enough topLevel) */
1601
1602         x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1603         requiredTallness = 0;
1604         while (x) {
1605                 x >>= YAFFS_TNODES_INTERNAL_BITS;
1606                 requiredTallness++;
1607         }
1608
1609
1610         if (requiredTallness > fStruct->topLevel) {
1611                 /* Not tall enough, gotta make the tree taller */
1612                 for (i = fStruct->topLevel; i < requiredTallness; i++) {
1613
1614                         tn = yaffs_GetTnode(dev);
1615
1616                         if (tn) {
1617                                 tn->internal[0] = fStruct->top;
1618                                 fStruct->top = tn;
1619                                 fStruct->topLevel++;
1620                         } else {
1621                                 T(YAFFS_TRACE_ERROR,
1622                                         (TSTR("yaffs: no more tnodes" TENDSTR)));
1623                                 return NULL;
1624                         }
1625                 }
1626         }
1627
1628         /* Traverse down to level 0, adding anything we need */
1629
1630         l = fStruct->topLevel;
1631         tn = fStruct->top;
1632
1633         if (l > 0) {
1634                 while (l > 0 && tn) {
1635                         x = (chunkId >>
1636                              (YAFFS_TNODES_LEVEL0_BITS +
1637                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
1638                             YAFFS_TNODES_INTERNAL_MASK;
1639
1640
1641                         if ((l > 1) && !tn->internal[x]) {
1642                                 /* Add missing non-level-zero tnode */
1643                                 tn->internal[x] = yaffs_GetTnode(dev);
1644                                 if(!tn->internal[x])
1645                                         return NULL;
1646                         } else if (l == 1) {
1647                                 /* Looking from level 1 at level 0 */
1648                                 if (passedTn) {
1649                                         /* If we already have one, then release it.*/
1650                                         if (tn->internal[x])
1651                                                 yaffs_FreeTnode(dev, tn->internal[x]);
1652                                         tn->internal[x] = passedTn;
1653
1654                                 } else if (!tn->internal[x]) {
1655                                         /* Don't have one, none passed in */
1656                                         tn->internal[x] = yaffs_GetTnode(dev);
1657                                         if(!tn->internal[x])
1658                                                 return NULL;
1659                                 }
1660                         }
1661
1662                         tn = tn->internal[x];
1663                         l--;
1664                 }
1665         } else {
1666                 /* top is level 0 */
1667                 if (passedTn) {
1668                         memcpy(tn, passedTn, (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
1669                         yaffs_FreeTnode(dev, passedTn);
1670                 }
1671         }
1672
1673         return tn;
1674 }
1675
1676 static int yaffs_FindChunkInGroup(yaffs_Device *dev, int theChunk,
1677                                 yaffs_ExtendedTags *tags, int objectId,
1678                                 int chunkInInode)
1679 {
1680         int j;
1681
1682         for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
1683                 if (yaffs_CheckChunkBit(dev, theChunk / dev->param.nChunksPerBlock,
1684                                 theChunk % dev->param.nChunksPerBlock)) {
1685                         
1686                         if(dev->chunkGroupSize == 1)
1687                                 return theChunk;
1688                         else {
1689                                 yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
1690                                                                 tags);
1691                                 if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
1692                                         /* found it; */
1693                                         return theChunk;
1694                                 }
1695                         }
1696                 }
1697                 theChunk++;
1698         }
1699         return -1;
1700 }
1701
1702
1703 /* DeleteWorker scans backwards through the tnode tree and deletes all the
1704  * chunks and tnodes in the file
1705  * Returns 1 if the tree was deleted.
1706  * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
1707  */
1708
1709 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
1710                               int chunkOffset, int *limit)
1711 {
1712         int i;
1713         int chunkInInode;
1714         int theChunk;
1715         yaffs_ExtendedTags tags;
1716         int foundChunk;
1717         yaffs_Device *dev = in->myDev;
1718
1719         int allDone = 1;
1720
1721         if (tn) {
1722                 if (level > 0) {
1723                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1724                              i--) {
1725                                 if (tn->internal[i]) {
1726                                         if (limit && (*limit) < 0) {
1727                                                 allDone = 0;
1728                                         } else {
1729                                                 allDone =
1730                                                         yaffs_DeleteWorker(in,
1731                                                                 tn->
1732                                                                 internal
1733                                                                 [i],
1734                                                                 level -
1735                                                                 1,
1736                                                                 (chunkOffset
1737                                                                         <<
1738                                                                         YAFFS_TNODES_INTERNAL_BITS)
1739                                                                 + i,
1740                                                                 limit);
1741                                         }
1742                                         if (allDone) {
1743                                                 yaffs_FreeTnode(dev,
1744                                                                 tn->
1745                                                                 internal[i]);
1746                                                 tn->internal[i] = NULL;
1747                                         }
1748                                 }
1749                         }
1750                         return (allDone) ? 1 : 0;
1751                 } else if (level == 0) {
1752                         int hitLimit = 0;
1753
1754                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
1755                                         i--) {
1756                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
1757                                 if (theChunk) {
1758
1759                                         chunkInInode = (chunkOffset <<
1760                                                 YAFFS_TNODES_LEVEL0_BITS) + i;
1761
1762                                         foundChunk =
1763                                                 yaffs_FindChunkInGroup(dev,
1764                                                                 theChunk,
1765                                                                 &tags,
1766                                                                 in->objectId,
1767                                                                 chunkInInode);
1768
1769                                         if (foundChunk > 0) {
1770                                                 yaffs_DeleteChunk(dev,
1771                                                                   foundChunk, 1,
1772                                                                   __LINE__);
1773                                                 in->nDataChunks--;
1774                                                 if (limit) {
1775                                                         *limit = *limit - 1;
1776                                                         if (*limit <= 0)
1777                                                                 hitLimit = 1;
1778                                                 }
1779
1780                                         }
1781
1782                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1783                                 }
1784
1785                         }
1786                         return (i < 0) ? 1 : 0;
1787
1788                 }
1789
1790         }
1791
1792         return 1;
1793
1794 }
1795
1796 static void yaffs_SoftDeleteChunk(yaffs_Device *dev, int chunk)
1797 {
1798         yaffs_BlockInfo *theBlock;
1799
1800         T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
1801
1802         theBlock = yaffs_GetBlockInfo(dev, chunk / dev->param.nChunksPerBlock);
1803         if (theBlock) {
1804                 theBlock->softDeletions++;
1805                 dev->nFreeChunks++;
1806                 yaffs_UpdateOldestDirtySequence(dev,theBlock);
1807         }
1808 }
1809
1810 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1811  * All soft deleting does is increment the block's softdelete count and pulls the chunk out
1812  * of the tnode.
1813  * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1814  */
1815
1816 static int yaffs_SoftDeleteWorker(yaffs_Object *in, yaffs_Tnode *tn,
1817                                   __u32 level, int chunkOffset)
1818 {
1819         int i;
1820         int theChunk;
1821         int allDone = 1;
1822         yaffs_Device *dev = in->myDev;
1823
1824         if (tn) {
1825                 if (level > 0) {
1826
1827                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1828                              i--) {
1829                                 if (tn->internal[i]) {
1830                                         allDone =
1831                                             yaffs_SoftDeleteWorker(in,
1832                                                                    tn->
1833                                                                    internal[i],
1834                                                                    level - 1,
1835                                                                    (chunkOffset
1836                                                                     <<
1837                                                                     YAFFS_TNODES_INTERNAL_BITS)
1838                                                                    + i);
1839                                         if (allDone) {
1840                                                 yaffs_FreeTnode(dev,
1841                                                                 tn->
1842                                                                 internal[i]);
1843                                                 tn->internal[i] = NULL;
1844                                         } else {
1845                                                 /* Hoosterman... how could this happen? */
1846                                         }
1847                                 }
1848                         }
1849                         return (allDone) ? 1 : 0;
1850                 } else if (level == 0) {
1851
1852                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1853                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
1854                                 if (theChunk) {
1855                                         /* Note this does not find the real chunk, only the chunk group.
1856                                          * We make an assumption that a chunk group is not larger than
1857                                          * a block.
1858                                          */
1859                                         yaffs_SoftDeleteChunk(dev, theChunk);
1860                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1861                                 }
1862
1863                         }
1864                         return 1;
1865
1866                 }
1867
1868         }
1869
1870         return 1;
1871
1872 }
1873
1874 static void yaffs_SoftDeleteFile(yaffs_Object *obj)
1875 {
1876         if (obj->deleted &&
1877             obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
1878                 if (obj->nDataChunks <= 0) {
1879                         /* Empty file with no duplicate object headers, just delete it immediately */
1880                         yaffs_FreeTnode(obj->myDev,
1881                                         obj->variant.fileVariant.top);
1882                         obj->variant.fileVariant.top = NULL;
1883                         T(YAFFS_TRACE_TRACING,
1884                           (TSTR("yaffs: Deleting empty file %d" TENDSTR),
1885                            obj->objectId));
1886                         yaffs_DoGenericObjectDeletion(obj);
1887                 } else {
1888                         yaffs_SoftDeleteWorker(obj,
1889                                                obj->variant.fileVariant.top,
1890                                                obj->variant.fileVariant.
1891                                                topLevel, 0);
1892                         obj->softDeleted = 1;
1893                 }
1894         }
1895 }
1896
1897 /* Pruning removes any part of the file structure tree that is beyond the
1898  * bounds of the file (ie that does not point to chunks).
1899  *
1900  * A file should only get pruned when its size is reduced.
1901  *
1902  * Before pruning, the chunks must be pulled from the tree and the
1903  * level 0 tnode entries must be zeroed out.
1904  * Could also use this for file deletion, but that's probably better handled
1905  * by a special case.
1906  *
1907  * This function is recursive. For levels > 0 the function is called again on
1908  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1909  * If there is no data in a subtree then it is pruned.
1910  */
1911
1912 static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device *dev, yaffs_Tnode *tn,
1913                                 __u32 level, int del0)
1914 {
1915         int i;
1916         int hasData;
1917
1918         if (tn) {
1919                 hasData = 0;
1920
1921                 if(level > 0){
1922                         for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1923                                 if (tn->internal[i]) {
1924                                         tn->internal[i] =
1925                                                 yaffs_PruneWorker(dev, tn->internal[i],
1926                                                         level - 1,
1927                                                         (i == 0) ? del0 : 1);
1928                                 }
1929
1930                                 if (tn->internal[i])
1931                                         hasData++;
1932                         }
1933                 } else {
1934                         int tnodeSize_u32 = yaffs_CalcTnodeSize(dev)/sizeof(__u32);
1935                         __u32 *map = (__u32 *)tn;
1936
1937                         for(i = 0; !hasData && i < tnodeSize_u32; i++){
1938                                 if(map[i])
1939                                         hasData++;
1940                         }
1941                 }
1942
1943                 if (hasData == 0 && del0) {
1944                         /* Free and return NULL */
1945
1946                         yaffs_FreeTnode(dev, tn);
1947                         tn = NULL;
1948                 }
1949
1950         }
1951
1952         return tn;
1953
1954 }
1955
1956 static int yaffs_PruneFileStructure(yaffs_Device *dev,
1957                                 yaffs_FileStructure *fStruct)
1958 {
1959         int i;
1960         int hasData;
1961         int done = 0;
1962         yaffs_Tnode *tn;
1963
1964         if (fStruct->topLevel > 0) {
1965                 fStruct->top =
1966                     yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);
1967
1968                 /* Now we have a tree with all the non-zero branches NULL but the height
1969                  * is the same as it was.
1970                  * Let's see if we can trim internal tnodes to shorten the tree.
1971                  * We can do this if only the 0th element in the tnode is in use
1972                  * (ie all the non-zero are NULL)
1973                  */
1974
1975                 while (fStruct->topLevel && !done) {
1976                         tn = fStruct->top;
1977
1978                         hasData = 0;
1979                         for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1980                                 if (tn->internal[i])
1981                                         hasData++;
1982                         }
1983
1984                         if (!hasData) {
1985                                 fStruct->top = tn->internal[0];
1986                                 fStruct->topLevel--;
1987                                 yaffs_FreeTnode(dev, tn);
1988                         } else {
1989                                 done = 1;
1990                         }
1991                 }
1992         }
1993
1994         return YAFFS_OK;
1995 }
1996
1997 /*-------------------- End of File Structure functions.-------------------*/
1998
1999 /* yaffs_CreateFreeObjects creates a bunch more objects and
2000  * adds them to the object free list.
2001  */
2002 static int yaffs_CreateFreeObjects(yaffs_Device *dev, int nObjects)
2003 {
2004         int i;
2005         yaffs_Object *newObjects;
2006         yaffs_ObjectList *list;
2007
2008         if (nObjects < 1)
2009                 return YAFFS_OK;
2010
2011         /* make these things */
2012         newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
2013         list = YMALLOC(sizeof(yaffs_ObjectList));
2014
2015         if (!newObjects || !list) {
2016                 if (newObjects){
2017                         YFREE(newObjects);
2018                         newObjects = NULL;
2019                 }
2020                 if (list){
2021                         YFREE(list);
2022                         list = NULL;
2023                 }
2024                 T(YAFFS_TRACE_ALLOCATE,
2025                   (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
2026                 return YAFFS_FAIL;
2027         }
2028
2029         /* Hook them into the free list */
2030         for (i = 0; i < nObjects - 1; i++) {
2031                 newObjects[i].siblings.next =
2032                                 (struct ylist_head *)(&newObjects[i + 1]);
2033         }
2034
2035         newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
2036         dev->freeObjects = newObjects;
2037         dev->nFreeObjects += nObjects;
2038         dev->nObjectsCreated += nObjects;
2039
2040         /* Now add this bunch of Objects to a list for freeing up. */
2041
2042         list->objects = newObjects;
2043         list->next = dev->allocatedObjectList;
2044         dev->allocatedObjectList = list;
2045
2046         return YAFFS_OK;
2047 }
2048
2049
2050 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
2051 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
2052 {
2053         yaffs_Object *tn = NULL;
2054
2055 #ifdef CONFIG_YAFFS_VALGRIND_TEST
2056         tn = YMALLOC(sizeof(yaffs_Object));
2057         if(tn)
2058                 dev->nObjectsCreated++;
2059 #else
2060         /* If there are none left make more */
2061         if (!dev->freeObjects)
2062                 yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
2063
2064         if (dev->freeObjects) {
2065                 tn = dev->freeObjects;
2066                 dev->freeObjects =
2067                         (yaffs_Object *) (dev->freeObjects->siblings.next);
2068                 dev->nFreeObjects--;
2069         }
2070 #endif
2071         if (tn) {
2072                 /* Now sweeten it up... */
2073
2074                 memset(tn, 0, sizeof(yaffs_Object));
2075                 tn->beingCreated = 1;
2076
2077                 tn->myDev = dev;
2078                 tn->hdrChunk = 0;
2079                 tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
2080                 YINIT_LIST_HEAD(&(tn->hardLinks));
2081                 YINIT_LIST_HEAD(&(tn->hashLink));
2082                 YINIT_LIST_HEAD(&tn->siblings);
2083
2084
2085                 /* Now make the directory sane */
2086                 if (dev->rootDir) {
2087                         tn->parent = dev->rootDir;
2088                         ylist_add(&(tn->siblings), &dev->rootDir->variant.directoryVariant.children);
2089                 }
2090
2091                 /* Add it to the lost and found directory.
2092                  * NB Can't put root or lostNFound in lostNFound so
2093                  * check if lostNFound exists first
2094                  */
2095                 if (dev->lostNFoundDir)
2096                         yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
2097
2098                 tn->beingCreated = 0;
2099         }
2100
2101         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
2102
2103         return tn;
2104 }
2105
2106 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev, int number,
2107                                                __u32 mode)
2108 {
2109
2110         yaffs_Object *obj =
2111             yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
2112         if (obj) {
2113                 obj->fake = 1;          /* it is fake so it might have no NAND presence... */
2114                 obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
2115                 obj->unlinkAllowed = 0; /* ... or unlink it */
2116                 obj->deleted = 0;
2117                 obj->unlinked = 0;
2118                 obj->yst_mode = mode;
2119                 obj->myDev = dev;
2120                 obj->hdrChunk = 0;      /* Not a valid chunk. */
2121         }
2122
2123         return obj;
2124
2125 }
2126
2127 static void yaffs_UnhashObject(yaffs_Object *tn)
2128 {
2129         int bucket;
2130         yaffs_Device *dev = tn->myDev;
2131
2132         /* If it is still linked into the bucket list, free from the list */
2133         if (!ylist_empty(&tn->hashLink)) {
2134                 ylist_del_init(&tn->hashLink);
2135                 bucket = yaffs_HashFunction(tn->objectId);
2136                 dev->objectBucket[bucket].count--;
2137         }
2138 }
2139
2140 /*  FreeObject frees up a Object and puts it back on the free list */
2141 static void yaffs_FreeObject(yaffs_Object *tn)
2142 {
2143         yaffs_Device *dev = tn->myDev;
2144
2145         T(YAFFS_TRACE_OS, (TSTR("FreeObject %p inode %p"TENDSTR), tn, tn->myInode));
2146
2147         if (!tn)
2148                 YBUG();
2149         if (tn->parent)
2150                 YBUG();
2151         if (!ylist_empty(&tn->siblings))
2152                 YBUG();
2153
2154
2155         if (tn->myInode) {
2156                 /* We're still hooked up to a cached inode.
2157                  * Don't delete now, but mark for later deletion
2158                  */
2159                 tn->deferedFree = 1;
2160                 return;
2161         }
2162
2163         yaffs_UnhashObject(tn);
2164
2165 #ifdef CONFIG_YAFFS_VALGRIND_TEST
2166         YFREE(tn);
2167         dev->nObjectsCreated--;
2168         tn = NULL;
2169 #else
2170         /* Link into the free list. */
2171         tn->siblings.next = (struct ylist_head *)(dev->freeObjects);
2172         dev->freeObjects = tn;
2173         dev->nFreeObjects++;
2174 #endif
2175         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
2176 }
2177
2178
2179 void yaffs_HandleDeferedFree(yaffs_Object *obj)
2180 {
2181         if (obj->deferedFree)
2182                 yaffs_FreeObject(obj);
2183 }
2184
2185
2186 static void yaffs_DeinitialiseObjects(yaffs_Device *dev)
2187 {
2188         /* Free the list of allocated Objects */
2189
2190         yaffs_ObjectList *tmp;
2191
2192         while (dev->allocatedObjectList) {
2193                 tmp = dev->allocatedObjectList->next;
2194                 YFREE(dev->allocatedObjectList->objects);
2195                 YFREE(dev->allocatedObjectList);
2196
2197                 dev->allocatedObjectList = tmp;
2198         }
2199
2200         dev->freeObjects = NULL;
2201         dev->nFreeObjects = 0;
2202         dev->nObjectsCreated = 0;
2203 }
2204
2205 static void yaffs_InitialiseObjects(yaffs_Device *dev)
2206 {
2207         int i;
2208
2209         dev->allocatedObjectList = NULL;
2210         dev->freeObjects = NULL;
2211         dev->nFreeObjects = 0;
2212
2213         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2214                 YINIT_LIST_HEAD(&dev->objectBucket[i].list);
2215                 dev->objectBucket[i].count = 0;
2216         }
2217 }
2218
2219 static int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
2220 {
2221         int i;
2222         int l = 999;
2223         int lowest = 999999;
2224
2225
2226         /* Search for the shortest list or one that
2227          * isn't too long.
2228          */
2229
2230         for (i = 0; i < 10 && lowest > 4; i++) {
2231                 dev->bucketFinder++;
2232                 dev->bucketFinder %= YAFFS_NOBJECT_BUCKETS;
2233                 if (dev->objectBucket[dev->bucketFinder].count < lowest) {
2234                         lowest = dev->objectBucket[dev->bucketFinder].count;
2235                         l = dev->bucketFinder;
2236                 }
2237
2238         }
2239
2240         return l;
2241 }
2242
2243 static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
2244 {
2245         int bucket = yaffs_FindNiceObjectBucket(dev);
2246
2247         /* Now find an object value that has not already been taken
2248          * by scanning the list.
2249          */
2250
2251         int found = 0;
2252         struct ylist_head *i;
2253
2254         __u32 n = (__u32) bucket;
2255
2256         /* yaffs_CheckObjectHashSanity();  */
2257
2258         while (!found) {
2259                 found = 1;
2260                 n += YAFFS_NOBJECT_BUCKETS;
2261                 if (1 || dev->objectBucket[bucket].count > 0) {
2262                         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2263                                 /* If there is already one in the list */
2264                                 if (i && ylist_entry(i, yaffs_Object,
2265                                                 hashLink)->objectId == n) {
2266                                         found = 0;
2267                                 }
2268                         }
2269                 }
2270         }
2271
2272         return n;
2273 }
2274
2275 static void yaffs_HashObject(yaffs_Object *in)
2276 {
2277         int bucket = yaffs_HashFunction(in->objectId);
2278         yaffs_Device *dev = in->myDev;
2279
2280         ylist_add(&in->hashLink, &dev->objectBucket[bucket].list);
2281         dev->objectBucket[bucket].count++;
2282 }
2283
2284 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev, __u32 number)
2285 {
2286         int bucket = yaffs_HashFunction(number);
2287         struct ylist_head *i;
2288         yaffs_Object *in;
2289
2290         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2291                 /* Look if it is in the list */
2292                 if (i) {
2293                         in = ylist_entry(i, yaffs_Object, hashLink);
2294                         if (in->objectId == number) {
2295
2296                                 /* Don't tell the VFS about this one if it is defered free */
2297                                 if (in->deferedFree)
2298                                         return NULL;
2299
2300                                 return in;
2301                         }
2302                 }
2303         }
2304
2305         return NULL;
2306 }
2307
2308 yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
2309                                     yaffs_ObjectType type)
2310 {
2311         yaffs_Object *theObject=NULL;
2312         yaffs_Tnode *tn = NULL;
2313
2314         if (number < 0)
2315                 number = yaffs_CreateNewObjectNumber(dev);
2316
2317         if (type == YAFFS_OBJECT_TYPE_FILE) {
2318                 tn = yaffs_GetTnode(dev);
2319                 if (!tn)
2320                         return NULL;
2321         }
2322
2323         theObject = yaffs_AllocateEmptyObject(dev);
2324         if (!theObject){
2325                 if(tn)
2326                         yaffs_FreeTnode(dev,tn);
2327                 return NULL;
2328         }
2329
2330
2331         if (theObject) {
2332                 theObject->fake = 0;
2333                 theObject->renameAllowed = 1;
2334                 theObject->unlinkAllowed = 1;
2335                 theObject->objectId = number;
2336                 yaffs_HashObject(theObject);
2337                 theObject->variantType = type;
2338 #ifdef CONFIG_YAFFS_WINCE
2339                 yfsd_WinFileTimeNow(theObject->win_atime);
2340                 theObject->win_ctime[0] = theObject->win_mtime[0] =
2341                     theObject->win_atime[0];
2342                 theObject->win_ctime[1] = theObject->win_mtime[1] =
2343                     theObject->win_atime[1];
2344
2345 #else
2346
2347                 theObject->yst_atime = theObject->yst_mtime =
2348                     theObject->yst_ctime = Y_CURRENT_TIME;
2349 #endif
2350                 switch (type) {
2351                 case YAFFS_OBJECT_TYPE_FILE:
2352                         theObject->variant.fileVariant.fileSize = 0;
2353                         theObject->variant.fileVariant.scannedFileSize = 0;
2354                         theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
2355                         theObject->variant.fileVariant.topLevel = 0;
2356                         theObject->variant.fileVariant.top = tn;
2357                         break;
2358                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2359                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
2360                                         children);
2361                         break;
2362                 case YAFFS_OBJECT_TYPE_SYMLINK:
2363                 case YAFFS_OBJECT_TYPE_HARDLINK:
2364                 case YAFFS_OBJECT_TYPE_SPECIAL:
2365                         /* No action required */
2366                         break;
2367                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2368                         /* todo this should not happen */
2369                         break;
2370                 }
2371         }
2372
2373         return theObject;
2374 }
2375
2376 static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev,
2377                                                       int number,
2378                                                       yaffs_ObjectType type)
2379 {
2380         yaffs_Object *theObject = NULL;
2381
2382         if (number > 0)
2383                 theObject = yaffs_FindObjectByNumber(dev, number);
2384
2385         if (!theObject)
2386                 theObject = yaffs_CreateNewObject(dev, number, type);
2387
2388         return theObject;
2389
2390 }
2391
2392
2393 static YCHAR *yaffs_CloneString(const YCHAR *str)
2394 {
2395         YCHAR *newStr = NULL;
2396         int len;
2397
2398         if (!str)
2399                 str = _Y("");
2400
2401         len = yaffs_strnlen(str,YAFFS_MAX_ALIAS_LENGTH);
2402         newStr = YMALLOC((len + 1) * sizeof(YCHAR));
2403         if (newStr){
2404                 yaffs_strncpy(newStr, str,len);
2405                 newStr[len] = 0;
2406         }
2407         return newStr;
2408
2409 }
2410
2411 /*
2412  * Mknod (create) a new object.
2413  * equivalentObject only has meaning for a hard link;
2414  * aliasString only has meaning for a symlink.
2415  * rdev only has meaning for devices (a subset of special objects)
2416  */
2417
2418 static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
2419                                        yaffs_Object *parent,
2420                                        const YCHAR *name,
2421                                        __u32 mode,
2422                                        __u32 uid,
2423                                        __u32 gid,
2424                                        yaffs_Object *equivalentObject,
2425                                        const YCHAR *aliasString, __u32 rdev)
2426 {
2427         yaffs_Object *in;
2428         YCHAR *str = NULL;
2429
2430         yaffs_Device *dev = parent->myDev;
2431
2432         /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
2433         if (yaffs_FindObjectByName(parent, name))
2434                 return NULL;
2435
2436         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2437                 str = yaffs_CloneString(aliasString);
2438                 if (!str)
2439                         return NULL;
2440         }
2441
2442         in = yaffs_CreateNewObject(dev, -1, type);
2443
2444         if (!in){
2445                 if(str)
2446                         YFREE(str);
2447                 return NULL;
2448         }
2449
2450
2451
2452
2453
2454         if (in) {
2455                 in->hdrChunk = 0;
2456                 in->valid = 1;
2457                 in->variantType = type;
2458
2459                 in->yst_mode = mode;
2460
2461 #ifdef CONFIG_YAFFS_WINCE
2462                 yfsd_WinFileTimeNow(in->win_atime);
2463                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
2464                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
2465
2466 #else
2467                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
2468
2469                 in->yst_rdev = rdev;
2470                 in->yst_uid = uid;
2471                 in->yst_gid = gid;
2472 #endif
2473                 in->nDataChunks = 0;
2474
2475                 yaffs_SetObjectName(in, name);
2476                 in->dirty = 1;
2477
2478                 yaffs_AddObjectToDirectory(parent, in);
2479
2480                 in->myDev = parent->myDev;
2481
2482                 switch (type) {
2483                 case YAFFS_OBJECT_TYPE_SYMLINK:
2484                         in->variant.symLinkVariant.alias = str;
2485                         break;
2486                 case YAFFS_OBJECT_TYPE_HARDLINK:
2487                         in->variant.hardLinkVariant.equivalentObject =
2488                                 equivalentObject;
2489                         in->variant.hardLinkVariant.equivalentObjectId =
2490                                 equivalentObject->objectId;
2491                         ylist_add(&in->hardLinks, &equivalentObject->hardLinks);
2492                         break;
2493                 case YAFFS_OBJECT_TYPE_FILE:
2494                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2495                 case YAFFS_OBJECT_TYPE_SPECIAL:
2496                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2497                         /* do nothing */
2498                         break;
2499                 }
2500
2501                 if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
2502                         /* Could not create the object header, fail the creation */
2503                         yaffs_DeleteObject(in);
2504                         in = NULL;
2505                 }
2506
2507                 yaffs_UpdateParent(parent);
2508         }
2509
2510         return in;
2511 }
2512
2513 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent, const YCHAR *name,
2514                         __u32 mode, __u32 uid, __u32 gid)
2515 {
2516         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2517                                 uid, gid, NULL, NULL, 0);
2518 }
2519
2520 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent, const YCHAR *name,
2521                                 __u32 mode, __u32 uid, __u32 gid)
2522 {
2523         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2524                                  mode, uid, gid, NULL, NULL, 0);
2525 }
2526
2527 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent, const YCHAR *name,
2528                                 __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
2529 {
2530         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2531                                  uid, gid, NULL, NULL, rdev);
2532 }
2533
2534 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const YCHAR *name,
2535                                 __u32 mode, __u32 uid, __u32 gid,
2536                                 const YCHAR *alias)
2537 {
2538         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2539                                 uid, gid, NULL, alias, 0);
2540 }
2541
2542 /* yaffs_Link returns the object id of the equivalent object.*/
2543 yaffs_Object *yaffs_Link(yaffs_Object *parent, const YCHAR *name,
2544                         yaffs_Object *equivalentObject)
2545 {
2546         /* Get the real object in case we were fed a hard link as an equivalent object */
2547         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
2548
2549         if (yaffs_MknodObject
2550             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
2551              equivalentObject, NULL, 0)) {
2552                 return equivalentObject;
2553         } else {
2554                 return NULL;
2555         }
2556
2557 }
2558
2559 static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir,
2560                                 const YCHAR *newName, int force, int shadows)
2561 {
2562         int unlinkOp;
2563         int deleteOp;
2564
2565         yaffs_Object *existingTarget;
2566
2567         if (newDir == NULL)
2568                 newDir = obj->parent;   /* use the old directory */
2569
2570         if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
2571                 T(YAFFS_TRACE_ALWAYS,
2572                   (TSTR
2573                    ("tragedy: yaffs_ChangeObjectName: newDir is not a directory"
2574                     TENDSTR)));
2575                 YBUG();
2576         }
2577
2578         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
2579         if (obj->myDev->param.isYaffs2)
2580                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
2581         else
2582                 unlinkOp = (newDir == obj->myDev->unlinkedDir
2583                             && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
2584
2585         deleteOp = (newDir == obj->myDev->deletedDir);
2586
2587         existingTarget = yaffs_FindObjectByName(newDir, newName);
2588
2589         /* If the object is a file going into the unlinked directory,
2590          *   then it is OK to just stuff it in since duplicate names are allowed.
2591          *   else only proceed if the new name does not exist and if we're putting
2592          *   it into a directory.
2593          */
2594         if ((unlinkOp ||
2595              deleteOp ||
2596              force ||
2597              (shadows > 0) ||
2598              !existingTarget) &&
2599             newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
2600                 yaffs_SetObjectName(obj, newName);
2601                 obj->dirty = 1;
2602
2603                 yaffs_AddObjectToDirectory(newDir, obj);
2604
2605                 if (unlinkOp)
2606                         obj->unlinked = 1;
2607
2608                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
2609                 if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows) >= 0)
2610                         return YAFFS_OK;
2611         }
2612
2613         return YAFFS_FAIL;
2614 }
2615
2616 int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName,
2617                 yaffs_Object *newDir, const YCHAR *newName)
2618 {
2619         yaffs_Object *obj = NULL;
2620         yaffs_Object *existingTarget = NULL;
2621         int force = 0;
2622         int result;
2623         yaffs_Device *dev;
2624
2625
2626         if (!oldDir || oldDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2627                 YBUG();
2628         if (!newDir || newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2629                 YBUG();
2630
2631         dev = oldDir->myDev;
2632
2633 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
2634         /* Special case for case insemsitive systems (eg. WinCE).
2635          * While look-up is case insensitive, the name isn't.
2636          * Therefore we might want to change x.txt to X.txt
2637         */
2638         if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0)
2639                 force = 1;
2640 #endif
2641
2642         if(yaffs_strnlen(newName,YAFFS_MAX_NAME_LENGTH+1) > YAFFS_MAX_NAME_LENGTH)
2643                 /* ENAMETOOLONG */
2644                 return YAFFS_FAIL;
2645
2646         obj = yaffs_FindObjectByName(oldDir, oldName);
2647
2648         if (obj && obj->renameAllowed) {
2649
2650                 /* Now do the handling for an existing target, if there is one */
2651
2652                 existingTarget = yaffs_FindObjectByName(newDir, newName);
2653                 if (existingTarget &&
2654                         existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
2655                         !ylist_empty(&existingTarget->variant.directoryVariant.children)) {
2656                         /* There is a target that is a non-empty directory, so we fail */
2657                         return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
2658                 } else if (existingTarget && existingTarget != obj) {
2659                         /* Nuke the target first, using shadowing,
2660                          * but only if it isn't the same object.
2661                          *
2662                          * Note we must disable gc otherwise it can mess up the shadowing.
2663                          *
2664                          */
2665                         dev->isDoingGC=1;
2666                         yaffs_ChangeObjectName(obj, newDir, newName, force,
2667                                                 existingTarget->objectId);
2668                         existingTarget->isShadowed = 1;
2669                         yaffs_UnlinkObject(existingTarget);
2670                         dev->isDoingGC=0;
2671                 }
2672
2673                 result = yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
2674
2675                 yaffs_UpdateParent(oldDir);
2676                 if(newDir != oldDir)
2677                         yaffs_UpdateParent(newDir);
2678                 
2679                 return result;
2680         }
2681         return YAFFS_FAIL;
2682 }
2683
2684 /*------------------------- Block Management and Page Allocation ----------------*/
2685
2686 static int yaffs_InitialiseBlocks(yaffs_Device *dev)
2687 {
2688         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
2689
2690         dev->blockInfo = NULL;
2691         dev->chunkBits = NULL;
2692
2693         dev->allocationBlock = -1;      /* force it to get a new one */
2694
2695         /* If the first allocation strategy fails, thry the alternate one */
2696         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
2697         if (!dev->blockInfo) {
2698                 dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
2699                 dev->blockInfoAlt = 1;
2700         } else
2701                 dev->blockInfoAlt = 0;
2702
2703         if (dev->blockInfo) {
2704                 /* Set up dynamic blockinfo stuff. */
2705                 dev->chunkBitmapStride = (dev->param.nChunksPerBlock + 7) / 8; /* round up bytes */
2706                 dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
2707                 if (!dev->chunkBits) {
2708                         dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
2709                         dev->chunkBitsAlt = 1;
2710                 } else
2711                         dev->chunkBitsAlt = 0;
2712         }
2713
2714         if (dev->blockInfo && dev->chunkBits) {
2715                 memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
2716                 memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
2717                 return YAFFS_OK;
2718         }
2719
2720         return YAFFS_FAIL;
2721 }
2722
2723 static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
2724 {
2725         if (dev->blockInfoAlt && dev->blockInfo)
2726                 YFREE_ALT(dev->blockInfo);
2727         else if (dev->blockInfo)
2728                 YFREE(dev->blockInfo);
2729
2730         dev->blockInfoAlt = 0;
2731
2732         dev->blockInfo = NULL;
2733
2734         if (dev->chunkBitsAlt && dev->chunkBits)
2735                 YFREE_ALT(dev->chunkBits);
2736         else if (dev->chunkBits)
2737                 YFREE(dev->chunkBits);
2738         dev->chunkBitsAlt = 0;
2739         dev->chunkBits = NULL;
2740 }
2741
2742 static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device *dev,
2743                                         yaffs_BlockInfo *bi)
2744 {
2745
2746         if (!dev->param.isYaffs2)
2747                 return 1;       /* disqualification only applies to yaffs2. */
2748
2749         if (!bi->hasShrinkHeader)
2750                 return 1;       /* can gc */
2751
2752         yaffs_FindOldestDirtySequence(dev);
2753
2754         /* Can't do gc of this block if there are any blocks older than this one that have
2755          * discarded pages.
2756          */
2757         return (bi->sequenceNumber <= dev->oldestDirtySequence);
2758 }
2759
2760 /*
2761  * yaffs_FindRefreshBlock()
2762  * periodically finds the oldest full block by sequence number for refreshing.
2763  * Only for yaffs2.
2764  */
2765 static __u32 yaffs_FindRefreshBlock(yaffs_Device *dev)
2766 {
2767         __u32 b ;
2768
2769         __u32 oldest = 0;
2770         __u32 oldestSequence = 0;
2771
2772         yaffs_BlockInfo *bi;
2773
2774         /*
2775          * If refresh period < 10 then refreshing is disabled.
2776          */
2777         if(dev->param.refreshPeriod < 10 ||
2778                 !dev->param.isYaffs2)
2779                 return oldest;
2780
2781         /*
2782          * Fix broken values.
2783          */
2784         if(dev->refreshSkip > dev->param.refreshPeriod)
2785                 dev->refreshSkip = dev->param.refreshPeriod;
2786
2787         if(dev->refreshSkip > 0){
2788                 dev->refreshSkip--;
2789                 return oldest;
2790         }
2791
2792         /*
2793          * Refresh skip is now zero.
2794          * We'll do a refresh this time around....
2795          * Update the refresh skip and find the oldest block.
2796          */
2797         dev->refreshSkip = dev->param.refreshPeriod;
2798         dev->refreshCount++;
2799
2800         for (b = dev->internalStartBlock; b <=dev->internalEndBlock; b++){
2801
2802                 bi = yaffs_GetBlockInfo(dev, b);
2803                 
2804
2805                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL){
2806
2807                         if(oldest < 1 ||
2808                                 bi->sequenceNumber < oldestSequence){
2809                                 oldest = b;
2810                                 oldestSequence = bi->sequenceNumber;
2811                         }
2812                 }
2813         }
2814
2815         if (oldest > 0) {
2816                 T(YAFFS_TRACE_GC,
2817                   (TSTR("GC refresh count %d selected block %d with sequenceNumber %d" TENDSTR),
2818                    dev->refreshCount, oldest, oldestSequence));
2819         }
2820
2821         return oldest;
2822 }
2823
2824 /*
2825  * FindDiretiestBlock is used to select the dirtiest block (or close enough)
2826  * for garbage collection.
2827  */
2828
2829 static int yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
2830                                         int aggressive)
2831 {
2832         int b = dev->currentDirtyChecker;
2833
2834         int i;
2835         int iterations;
2836         int dirtiest = -1;
2837         int pagesInUse = 0;
2838         int prioritised = 0;
2839         yaffs_BlockInfo *bi;
2840         int pendingPrioritisedExist = 0;
2841
2842         /* First let's see if we need to grab a prioritised block */
2843         if (dev->hasPendingPrioritisedGCs) {
2844                 for (i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++) {
2845
2846                         bi = yaffs_GetBlockInfo(dev, i);
2847                         /* yaffs_VerifyBlock(dev,bi,i); */
2848
2849                         if (bi->gcPrioritise) {
2850                                 pendingPrioritisedExist = 1;
2851                                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2852                                    yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2853                                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2854                                         dirtiest = i;
2855                                         prioritised = 1;
2856                                         aggressive = 1; /* Fool the non-aggressive skip logiv below */
2857                                 }
2858                         }
2859                 }
2860
2861                 if (!pendingPrioritisedExist) /* None found, so we can clear this */
2862                         dev->hasPendingPrioritisedGCs = 0;
2863         }
2864
2865         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2866          * search harder.
2867          * else (we're doing a leasurely gc), then we only bother to do this if the
2868          * block has only a few pages in use.
2869          */
2870
2871         dev->nonAggressiveSkip--;
2872
2873         if (!aggressive && (dev->nonAggressiveSkip > 0))
2874                 return -1;
2875
2876         if (!prioritised)
2877                 pagesInUse =
2878                         (aggressive) ? dev->param.nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
2879
2880         if (aggressive)
2881                 iterations =
2882                     dev->internalEndBlock - dev->internalStartBlock + 1;
2883         else {
2884                 iterations =
2885                     dev->internalEndBlock - dev->internalStartBlock + 1;
2886                 iterations = iterations / 16;
2887                 if (iterations > 200)
2888                         iterations = 200;
2889         }
2890
2891         for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
2892                 b++;
2893                 if (b < dev->internalStartBlock || b > dev->internalEndBlock)
2894                         b = dev->internalStartBlock;
2895
2896                 if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
2897                         T(YAFFS_TRACE_ERROR,
2898                           (TSTR("**>> Block %d is not valid" TENDSTR), b));
2899                         YBUG();
2900                 }
2901
2902                 bi = yaffs_GetBlockInfo(dev, b);
2903
2904                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2905                         (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
2906                                 yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2907                         dirtiest = b;
2908                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2909                 }
2910         }
2911
2912         dev->currentDirtyChecker = b;
2913
2914         if (dirtiest > 0) {
2915                 T(YAFFS_TRACE_GC,
2916                   (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
2917                    dev->param.nChunksPerBlock - pagesInUse, prioritised));
2918         }
2919
2920         if (dirtiest > 0)
2921                 dev->nonAggressiveSkip = 4;
2922
2923         return dirtiest;
2924 }
2925
2926 static void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
2927 {
2928         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
2929
2930         int erasedOk = 0;
2931
2932         /* If the block is still healthy erase it and mark as clean.
2933          * If the block has had a data failure, then retire it.
2934          */
2935
2936         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2937                 (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
2938                 blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
2939
2940         yaffs_ClearOldestDirtySequence(dev,bi);
2941
2942         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
2943
2944         if (!bi->needsRetiring) {
2945                 yaffs_InvalidateCheckpoint(dev);
2946                 erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
2947                 if (!erasedOk) {
2948                         dev->nErasureFailures++;
2949                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2950                           (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
2951                 }
2952         }
2953
2954         if (erasedOk &&
2955             ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
2956                 int i;
2957                 for (i = 0; i < dev->param.nChunksPerBlock; i++) {
2958                         if (!yaffs_CheckChunkErased
2959                             (dev, blockNo * dev->param.nChunksPerBlock + i)) {
2960                                 T(YAFFS_TRACE_ERROR,
2961                                   (TSTR
2962                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
2963                                     TENDSTR), blockNo, i));
2964                         }
2965                 }
2966         }
2967
2968         if (erasedOk) {
2969                 /* Clean it up... */
2970                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
2971                 bi->sequenceNumber = 0;
2972                 dev->nErasedBlocks++;
2973                 bi->pagesInUse = 0;
2974                 bi->softDeletions = 0;
2975                 bi->hasShrinkHeader = 0;
2976                 bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
2977                 bi->gcPrioritise = 0;
2978                 yaffs_ClearChunkBits(dev, blockNo);
2979
2980                 T(YAFFS_TRACE_ERASE,
2981                   (TSTR("Erased block %d" TENDSTR), blockNo));
2982         } else {
2983                 dev->nFreeChunks -= dev->param.nChunksPerBlock; /* We lost a block of free space */
2984
2985                 yaffs_RetireBlock(dev, blockNo);
2986                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2987                   (TSTR("**>> Block %d retired" TENDSTR), blockNo));
2988         }
2989 }
2990
2991 static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
2992 {
2993         int i;
2994
2995         yaffs_BlockInfo *bi;
2996
2997         if (dev->nErasedBlocks < 1) {
2998                 /* Hoosterman we've got a problem.
2999                  * Can't get space to gc
3000                  */
3001                 T(YAFFS_TRACE_ERROR,
3002                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
3003
3004                 return -1;
3005         }
3006
3007         /* Find an empty block. */
3008
3009         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
3010                 dev->allocationBlockFinder++;
3011                 if (dev->allocationBlockFinder < dev->internalStartBlock
3012                     || dev->allocationBlockFinder > dev->internalEndBlock) {
3013                         dev->allocationBlockFinder = dev->internalStartBlock;
3014                 }
3015
3016                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
3017
3018                 if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
3019                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
3020                         dev->sequenceNumber++;
3021                         bi->sequenceNumber = dev->sequenceNumber;
3022                         dev->nErasedBlocks--;
3023                         T(YAFFS_TRACE_ALLOCATE,
3024                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
3025                            dev->allocationBlockFinder, dev->sequenceNumber,
3026                            dev->nErasedBlocks));
3027                         return dev->allocationBlockFinder;
3028                 }
3029         }
3030
3031         T(YAFFS_TRACE_ALWAYS,
3032           (TSTR
3033            ("yaffs tragedy: no more erased blocks, but there should have been %d"
3034             TENDSTR), dev->nErasedBlocks));
3035
3036         return -1;
3037 }
3038
3039
3040
3041 static int yaffs_CalcCheckpointBlocksRequired(yaffs_Device *dev)
3042 {
3043         if (!dev->nCheckpointBlocksRequired &&
3044            dev->param.isYaffs2) {
3045                 /* Not a valid value so recalculate */
3046                 int nBytes = 0;
3047                 int nBlocks;
3048                 int devBlocks = (dev->param.endBlock - dev->param.startBlock + 1);
3049                 int tnodeSize = yaffs_CalcTnodeSize(dev);
3050
3051                 nBytes += sizeof(yaffs_CheckpointValidity);
3052                 nBytes += sizeof(yaffs_CheckpointDevice);
3053                 nBytes += devBlocks * sizeof(yaffs_BlockInfo);
3054                 nBytes += devBlocks * dev->chunkBitmapStride;
3055                 nBytes += (sizeof(yaffs_CheckpointObject) + sizeof(__u32)) * (dev->nObjectsCreated - dev->nFreeObjects);
3056                 nBytes += (tnodeSize + sizeof(__u32)) * (dev->nTnodesCreated - dev->nFreeTnodes);
3057                 nBytes += sizeof(yaffs_CheckpointValidity);
3058                 nBytes += sizeof(__u32); /* checksum*/
3059
3060                 /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
3061
3062                 nBlocks = (nBytes/(dev->nDataBytesPerChunk * dev->param.nChunksPerBlock)) + 3;
3063
3064                 dev->nCheckpointBlocksRequired = nBlocks;
3065         }
3066
3067         return dev->nCheckpointBlocksRequired;
3068 }
3069
3070 /*
3071  * Check if there's space to allocate...
3072  * Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
3073  */
3074 static int yaffs_CheckSpaceForAllocation(yaffs_Device *dev)
3075 {
3076         int reservedChunks;
3077         int reservedBlocks = dev->param.nReservedBlocks;
3078         int checkpointBlocks;
3079
3080         if (dev->param.isYaffs2) {
3081                 checkpointBlocks =  yaffs_CalcCheckpointBlocksRequired(dev) -
3082                                     dev->blocksInCheckpoint;
3083                 if (checkpointBlocks < 0)
3084                         checkpointBlocks = 0;
3085         } else {
3086                 checkpointBlocks = 0;
3087         }
3088
3089         reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->param.nChunksPerBlock);
3090
3091         return (dev->nFreeChunks > reservedChunks);
3092 }
3093
3094 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
3095                 yaffs_BlockInfo **blockUsedPtr)
3096 {
3097         int retVal;
3098         yaffs_BlockInfo *bi;
3099
3100         if (dev->allocationBlock < 0) {
3101                 /* Get next block to allocate off */
3102                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
3103                 dev->allocationPage = 0;
3104         }
3105
3106         if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
3107                 /* Not enough space to allocate unless we're allowed to use the reserve. */
3108                 return -1;
3109         }
3110
3111         if (dev->nErasedBlocks < dev->param.nReservedBlocks
3112                         && dev->allocationPage == 0) {
3113                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
3114         }
3115
3116         /* Next page please.... */
3117         if (dev->allocationBlock >= 0) {
3118                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
3119
3120                 retVal = (dev->allocationBlock * dev->param.nChunksPerBlock) +
3121                         dev->allocationPage;
3122                 bi->pagesInUse++;
3123                 yaffs_SetChunkBit(dev, dev->allocationBlock,
3124                                 dev->allocationPage);
3125
3126                 dev->allocationPage++;
3127
3128                 dev->nFreeChunks--;
3129
3130                 /* If the block is full set the state to full */
3131                 if (dev->allocationPage >= dev->param.nChunksPerBlock) {
3132                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
3133                         dev->allocationBlock = -1;
3134                 }
3135
3136                 if (blockUsedPtr)
3137                         *blockUsedPtr = bi;
3138
3139                 return retVal;
3140         }
3141
3142         T(YAFFS_TRACE_ERROR,
3143                         (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
3144
3145         return -1;
3146 }
3147
3148 static int yaffs_GetErasedChunks(yaffs_Device *dev)
3149 {
3150         int n;
3151
3152         n = dev->nErasedBlocks * dev->param.nChunksPerBlock;
3153
3154         if (dev->allocationBlock > 0)
3155                 n += (dev->param.nChunksPerBlock - dev->allocationPage);
3156
3157         return n;
3158
3159 }
3160
3161 /*
3162  * yaffs_SkipRestOfBlock() skips over the rest of the allocation block
3163  * if we don't want to write to it.
3164  */
3165 static void yaffs_SkipRestOfBlock(yaffs_Device *dev)
3166 {
3167         if(dev->allocationBlock > 0){
3168                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
3169                 if(bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING){
3170                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
3171                         dev->allocationBlock = -1;
3172                 }
3173         }
3174 }
3175
3176
3177 static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
3178                 int wholeBlock)
3179 {
3180         int oldChunk;
3181         int newChunk;
3182         int markNAND;
3183         int retVal = YAFFS_OK;
3184         int cleanups = 0;
3185         int i;
3186         int isCheckpointBlock;
3187         int matchingChunk;
3188         int maxCopies;
3189
3190         int chunksBefore = yaffs_GetErasedChunks(dev);
3191         int chunksAfter;
3192
3193         yaffs_ExtendedTags tags;
3194
3195         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
3196
3197         yaffs_Object *object;
3198
3199         isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
3200
3201
3202         T(YAFFS_TRACE_TRACING,
3203                         (TSTR("Collecting block %d, in use %d, shrink %d, wholeBlock %d" TENDSTR),
3204                          block,
3205                          bi->pagesInUse,
3206                          bi->hasShrinkHeader,
3207                          wholeBlock));
3208
3209         /*yaffs_VerifyFreeChunks(dev); */
3210
3211         if(bi->blockState == YAFFS_BLOCK_STATE_FULL)
3212                 bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
3213         
3214         bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
3215
3216         /* Take off the number of soft deleted entries because
3217          * they're going to get really deleted during GC.
3218          */
3219         if(dev->gcChunk == 0) /* first time through for this block */
3220                 dev->nFreeChunks -= bi->softDeletions;
3221
3222         dev->isDoingGC = 1;
3223
3224         if (isCheckpointBlock ||
3225                         !yaffs_StillSomeChunkBits(dev, block)) {
3226                 T(YAFFS_TRACE_TRACING,
3227                                 (TSTR
3228                                  ("Collecting block %d that has no chunks in use" TENDSTR),
3229                                  block));
3230                 yaffs_BlockBecameDirty(dev, block);
3231         } else {
3232
3233                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
3234
3235                 yaffs_VerifyBlock(dev, bi, block);
3236
3237                 maxCopies = (wholeBlock) ? dev->param.nChunksPerBlock : 10;
3238                 oldChunk = block * dev->param.nChunksPerBlock + dev->gcChunk;
3239
3240                 for (/* init already done */;
3241                      retVal == YAFFS_OK &&
3242                      dev->gcChunk < dev->param.nChunksPerBlock &&
3243                      (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) &&
3244                      maxCopies > 0;
3245                      dev->gcChunk++, oldChunk++) {
3246                         if (yaffs_CheckChunkBit(dev, block, dev->gcChunk)) {
3247
3248                                 /* This page is in use and might need to be copied off */
3249
3250                                 maxCopies--;
3251
3252                                 markNAND = 1;
3253
3254                                 yaffs_InitialiseTags(&tags);
3255
3256                                 yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
3257                                                                 buffer, &tags);
3258
3259                                 object =
3260                                     yaffs_FindObjectByNumber(dev,
3261                                                              tags.objectId);
3262
3263                                 T(YAFFS_TRACE_GC_DETAIL,
3264                                   (TSTR
3265                                    ("Collecting chunk in block %d, %d %d %d " TENDSTR),
3266                                    dev->gcChunk, tags.objectId, tags.chunkId,
3267                                    tags.byteCount));
3268
3269                                 if (object && !yaffs_SkipVerification(dev)) {
3270                                         if (tags.chunkId == 0)
3271                                                 matchingChunk = object->hdrChunk;
3272                                         else if (object->softDeleted)
3273                                                 matchingChunk = oldChunk; /* Defeat the test */
3274                                         else
3275                                                 matchingChunk = yaffs_FindChunkInFile(object, tags.chunkId, NULL);
3276
3277                                         if (oldChunk != matchingChunk)
3278                                                 T(YAFFS_TRACE_ERROR,
3279                                                   (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
3280                                                   oldChunk, matchingChunk, tags.objectId, tags.chunkId));
3281
3282                                 }
3283
3284                                 if (!object) {
3285                                         T(YAFFS_TRACE_ERROR,
3286                                           (TSTR
3287                                            ("page %d in gc has no object: %d %d %d "
3288                                             TENDSTR), oldChunk,
3289                                             tags.objectId, tags.chunkId, tags.byteCount));
3290                                 }
3291
3292                                 if (object &&
3293                                     object->deleted &&
3294                                     object->softDeleted &&
3295                                     tags.chunkId != 0) {
3296                                         /* Data chunk in a soft deleted file, throw it away
3297                                          * It's a soft deleted data chunk,
3298                                          * No need to copy this, just forget about it and
3299                                          * fix up the object.
3300                                          */
3301
3302                                         object->nDataChunks--;
3303
3304                                         if (object->nDataChunks <= 0) {
3305                                                 /* remeber to clean up the object */
3306                                                 dev->gcCleanupList[cleanups] =
3307                                                     tags.objectId;
3308                                                 cleanups++;
3309                                         }
3310                                         markNAND = 0;
3311                                 } else if (0) {
3312                                         /* Todo object && object->deleted && object->nDataChunks == 0 */
3313                                         /* Deleted object header with no data chunks.
3314                                          * Can be discarded and the file deleted.
3315                                          */
3316                                         object->hdrChunk = 0;
3317                                         yaffs_FreeTnode(object->myDev,
3318                                                         object->variant.
3319                                                         fileVariant.top);
3320                                         object->variant.fileVariant.top = NULL;
3321                                         yaffs_DoGenericObjectDeletion(object);
3322
3323                                 } else if (object) {
3324                                         /* It's either a data chunk in a live file or
3325                                          * an ObjectHeader, so we're interested in it.
3326                                          * NB Need to keep the ObjectHeaders of deleted files
3327                                          * until the whole file has been deleted off
3328                                          */
3329                                         tags.serialNumber++;
3330
3331                                         dev->nGCCopies++;
3332
3333                                         if (tags.chunkId == 0) {
3334                                                 /* It is an object Id,
3335                                                  * We need to nuke the shrinkheader flags first
3336                                                  * Also need to clean up shadowing.
3337                                                  * We no longer want the shrinkHeader flag since its work is done
3338                                                  * and if it is left in place it will mess up scanning.
3339                                                  */
3340
3341                                                 yaffs_ObjectHeader *oh;
3342                                                 oh = (yaffs_ObjectHeader *)buffer;
3343                                                 oh->isShrink = 0;
3344                                                 tags.extraIsShrinkHeader = 0;
3345                                                 oh->shadowsObject = 0;
3346                                                 oh->inbandShadowsObject = 0;
3347                                                 if(object->variantType == YAFFS_OBJECT_TYPE_FILE)
3348                                                         oh->fileSize = object->variant.fileVariant.fileSize;
3349                                                 tags.extraShadows = 0;
3350
3351                                                 yaffs_VerifyObjectHeader(object, oh, &tags, 1);
3352                                                 newChunk =
3353                                                     yaffs_WriteNewChunkWithTagsToNAND(dev,(__u8 *) oh, &tags, 1);
3354                                         } else
3355                                                 newChunk =
3356                                                     yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
3357
3358                                         if (newChunk < 0) {
3359                                                 retVal = YAFFS_FAIL;
3360                                         } else {
3361
3362                                                 /* Ok, now fix up the Tnodes etc. */
3363
3364                                                 if (tags.chunkId == 0) {
3365                                                         /* It's a header */
3366                                                         object->hdrChunk =  newChunk;
3367                                                         object->serial =   tags.serialNumber;
3368                                                 } else {
3369                                                         /* It's a data chunk */
3370                                                         int ok;
3371                                                         ok = yaffs_PutChunkIntoFile
3372                                                             (object,
3373                                                              tags.chunkId,
3374                                                              newChunk, 0);
3375                                                 }
3376                                         }
3377                                 }
3378
3379                                 if (retVal == YAFFS_OK)
3380                                         yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
3381
3382                         }
3383                 }
3384
3385                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3386
3387
3388                 /* Do any required cleanups */
3389                 for (i = 0; i < cleanups; i++) {
3390                         /* Time to delete the file too */
3391                         object =
3392                             yaffs_FindObjectByNumber(dev,
3393                                                      dev->gcCleanupList[i]);
3394                         if (object) {
3395                                 yaffs_FreeTnode(dev,
3396                                                 object->variant.fileVariant.
3397                                                 top);
3398                                 object->variant.fileVariant.top = NULL;
3399                                 T(YAFFS_TRACE_GC,
3400                                   (TSTR
3401                                    ("yaffs: About to finally delete object %d"
3402                                     TENDSTR), object->objectId));
3403                                 yaffs_DoGenericObjectDeletion(object);
3404                                 object->myDev->nDeletedFiles--;
3405                         }
3406
3407                 }
3408
3409         }
3410
3411         yaffs_VerifyCollectedBlock(dev, bi, block);
3412
3413
3414
3415         /* If the gc completed then clear the current gcBlock so that we find another. */
3416         if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING) {
3417                 chunksAfter = yaffs_GetErasedChunks(dev);
3418                 if (chunksBefore >= chunksAfter) {
3419                         T(YAFFS_TRACE_GC,
3420                           (TSTR
3421                            ("gc did not increase free chunks before %d after %d"
3422                             TENDSTR), chunksBefore, chunksAfter));
3423                 }
3424                 dev->gcBlock = -1;
3425                 dev->gcChunk = 0;
3426         }
3427
3428         dev->isDoingGC = 0;
3429
3430         return retVal;
3431 }
3432
3433 /* New garbage collector
3434  * If we're very low on erased blocks then we do aggressive garbage collection
3435  * otherwise we do "leasurely" garbage collection.
3436  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
3437  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
3438  *
3439  * The idea is to help clear out space in a more spread-out manner.
3440  * Dunno if it really does anything useful.
3441  */
3442 static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
3443 {
3444         int block;
3445         int aggressive;
3446         int gcOk = YAFFS_OK;
3447         int maxTries = 0;
3448
3449         int checkpointBlockAdjust;
3450
3451         if (dev->isDoingGC) {
3452                 /* Bail out so we don't get recursive gc */
3453                 return YAFFS_OK;
3454         }
3455
3456         /* This loop should pass the first time.
3457          * We'll only see looping here if the erase of the collected block fails.
3458          */
3459
3460         do {
3461                 maxTries++;
3462
3463                 checkpointBlockAdjust = yaffs_CalcCheckpointBlocksRequired(dev) - dev->blocksInCheckpoint;
3464                 if (checkpointBlockAdjust < 0)
3465                         checkpointBlockAdjust = 0;
3466
3467                 /* If we need a block soon then do aggressive gc.*/
3468                 if (dev->nErasedBlocks < (dev->param.nReservedBlocks + checkpointBlockAdjust + 2))
3469                         aggressive = 1;
3470                 else
3471                         aggressive = 0;
3472
3473                 /* If we don't already have a block being gc'd then see if we should start another */
3474
3475                 if (dev->gcBlock < 1 && !aggressive) {
3476                         dev->gcBlock = yaffs_FindRefreshBlock(dev);
3477                         dev->gcChunk = 0;
3478                 }
3479                 if (dev->gcBlock < 1) {
3480                         dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive);
3481                         dev->gcChunk = 0;
3482                 }
3483
3484                 block = dev->gcBlock;
3485
3486                 if (block > 0) {
3487                         dev->garbageCollections++;
3488                         if (!aggressive)
3489                                 dev->passiveGarbageCollections++;
3490
3491                         T(YAFFS_TRACE_GC,
3492                           (TSTR
3493                            ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
3494                            dev->nErasedBlocks, aggressive));
3495
3496                         gcOk = yaffs_GarbageCollectBlock(dev, block, aggressive);
3497                 }
3498
3499                 if (dev->nErasedBlocks < (dev->param.nReservedBlocks) && block > 0) {
3500                         T(YAFFS_TRACE_GC,
3501                           (TSTR
3502                            ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
3503                             TENDSTR), dev->nErasedBlocks, maxTries, block));
3504                 }
3505         } while ((dev->nErasedBlocks < dev->param.nReservedBlocks) &&
3506                  (block > 0) &&
3507                  (maxTries < 2));
3508
3509         return aggressive ? gcOk : YAFFS_OK;
3510 }
3511
3512 /*-------------------------  TAGS --------------------------------*/
3513
3514 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
3515                            int chunkInObject)
3516 {
3517         return (tags->chunkId == chunkInObject &&
3518                 tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
3519
3520 }
3521
3522
3523 /*-------------------- Data file manipulation -----------------*/
3524
3525 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
3526                                  yaffs_ExtendedTags *tags)
3527 {
3528         /*Get the Tnode, then get the level 0 offset chunk offset */
3529         yaffs_Tnode *tn;
3530         int theChunk = -1;
3531         yaffs_ExtendedTags localTags;
3532         int retVal = -1;
3533
3534         yaffs_Device *dev = in->myDev;
3535
3536         if (!tags) {
3537                 /* Passed a NULL, so use our own tags space */
3538                 tags = &localTags;
3539         }
3540
3541         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3542
3543         if (tn) {
3544                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3545
3546                 retVal =
3547                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3548                                            chunkInInode);
3549         }
3550         return retVal;
3551 }
3552
3553 static int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in, int chunkInInode,
3554                                           yaffs_ExtendedTags *tags)
3555 {
3556         /* Get the Tnode, then get the level 0 offset chunk offset */
3557         yaffs_Tnode *tn;
3558         int theChunk = -1;
3559         yaffs_ExtendedTags localTags;
3560
3561         yaffs_Device *dev = in->myDev;
3562         int retVal = -1;
3563
3564         if (!tags) {
3565                 /* Passed a NULL, so use our own tags space */
3566                 tags = &localTags;
3567         }
3568
3569         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3570
3571         if (tn) {
3572
3573                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3574
3575                 retVal =
3576                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3577                                            chunkInInode);
3578
3579                 /* Delete the entry in the filestructure (if found) */
3580                 if (retVal != -1)
3581                         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, 0);
3582         }
3583
3584         return retVal;
3585 }
3586
3587 #ifdef YAFFS_PARANOID
3588
3589 static int yaffs_CheckFileSanity(yaffs_Object *in)
3590 {
3591         int chunk;
3592         int nChunks;
3593         int fSize;
3594         int failed = 0;
3595         int objId;
3596         yaffs_Tnode *tn;
3597         yaffs_Tags localTags;
3598         yaffs_Tags *tags = &localTags;
3599         int theChunk;
3600         int chunkDeleted;
3601
3602         if (in->variantType != YAFFS_OBJECT_TYPE_FILE)
3603                 return YAFFS_FAIL;
3604
3605         objId = in->objectId;
3606         fSize = in->variant.fileVariant.fileSize;
3607         nChunks =
3608             (fSize + in->myDev->nDataBytesPerChunk - 1) / in->myDev->nDataBytesPerChunk;
3609
3610         for (chunk = 1; chunk <= nChunks; chunk++) {
3611                 tn = yaffs_FindLevel0Tnode(in->myDev, &in->variant.fileVariant,
3612                                            chunk);
3613
3614                 if (tn) {
3615
3616                         theChunk = yaffs_GetChunkGroupBase(dev, tn, chunk);
3617
3618                         if (yaffs_CheckChunkBits
3619                             (dev, theChunk / dev->param.nChunksPerBlock,
3620                              theChunk % dev->param.nChunksPerBlock)) {
3621
3622                                 yaffs_ReadChunkTagsFromNAND(in->myDev, theChunk,
3623                                                             tags,
3624                                                             &chunkDeleted);
3625                                 if (yaffs_TagsMatch
3626                                     (tags, in->objectId, chunk, chunkDeleted)) {
3627                                         /* found it; */
3628
3629                                 }
3630                         } else {
3631
3632                                 failed = 1;
3633                         }
3634
3635                 } else {
3636                         /* T(("No level 0 found for %d\n", chunk)); */
3637                 }
3638         }
3639
3640         return failed ? YAFFS_FAIL : YAFFS_OK;
3641 }
3642
3643 #endif
3644
3645 static int yaffs_PutChunkIntoFile(yaffs_Object *in, int chunkInInode,
3646                                   int chunkInNAND, int inScan)
3647 {
3648         /* NB inScan is zero unless scanning.
3649          * For forward scanning, inScan is > 0;
3650          * for backward scanning inScan is < 0
3651          *
3652          * chunkInNAND = 0 is a dummy insert to make sure the tnodes are there.
3653          */
3654
3655         yaffs_Tnode *tn;
3656         yaffs_Device *dev = in->myDev;
3657         int existingChunk;
3658         yaffs_ExtendedTags existingTags;
3659         yaffs_ExtendedTags newTags;
3660         unsigned existingSerial, newSerial;
3661
3662         if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
3663                 /* Just ignore an attempt at putting a chunk into a non-file during scanning
3664                  * If it is not during Scanning then something went wrong!
3665                  */
3666                 if (!inScan) {
3667                         T(YAFFS_TRACE_ERROR,
3668                           (TSTR
3669                            ("yaffs tragedy:attempt to put data chunk into a non-file"
3670                             TENDSTR)));
3671                         YBUG();
3672                 }
3673
3674                 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
3675                 return YAFFS_OK;
3676         }
3677
3678         tn = yaffs_AddOrFindLevel0Tnode(dev,
3679                                         &in->variant.fileVariant,
3680                                         chunkInInode,
3681                                         NULL);
3682         if (!tn)
3683                 return YAFFS_FAIL;
3684         
3685         if(!chunkInNAND)
3686                 /* Dummy insert, bail now */
3687                 return YAFFS_OK;
3688
3689         existingChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3690
3691         if (inScan != 0) {
3692                 /* If we're scanning then we need to test for duplicates
3693                  * NB This does not need to be efficient since it should only ever
3694                  * happen when the power fails during a write, then only one
3695                  * chunk should ever be affected.
3696                  *
3697                  * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
3698                  * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
3699                  */
3700
3701                 if (existingChunk > 0) {
3702                         /* NB Right now existing chunk will not be real chunkId if the device >= 32MB
3703                          *    thus we have to do a FindChunkInFile to get the real chunk id.
3704                          *
3705                          * We have a duplicate now we need to decide which one to use:
3706                          *
3707                          * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
3708                          * Forward scanning YAFFS2: The new one is what we use, dump the old one.
3709                          * YAFFS1: Get both sets of tags and compare serial numbers.
3710                          */
3711
3712                         if (inScan > 0) {
3713                                 /* Only do this for forward scanning */
3714                                 yaffs_ReadChunkWithTagsFromNAND(dev,
3715                                                                 chunkInNAND,
3716                                                                 NULL, &newTags);
3717
3718                                 /* Do a proper find */
3719                                 existingChunk =
3720                                     yaffs_FindChunkInFile(in, chunkInInode,
3721                                                           &existingTags);
3722                         }
3723
3724                         if (existingChunk <= 0) {
3725                                 /*Hoosterman - how did this happen? */
3726
3727                                 T(YAFFS_TRACE_ERROR,
3728                                   (TSTR
3729                                    ("yaffs tragedy: existing chunk < 0 in scan"
3730                                     TENDSTR)));
3731
3732                         }
3733
3734                         /* NB The deleted flags should be false, otherwise the chunks will
3735                          * not be loaded during a scan
3736                          */
3737
3738                         if (inScan > 0) {
3739                                 newSerial = newTags.serialNumber;
3740                                 existingSerial = existingTags.serialNumber;
3741                         }
3742
3743                         if ((inScan > 0) &&
3744                             (in->myDev->param.isYaffs2 ||
3745                              existingChunk <= 0 ||
3746                              ((existingSerial + 1) & 3) == newSerial)) {
3747                                 /* Forward scanning.
3748                                  * Use new
3749                                  * Delete the old one and drop through to update the tnode
3750                                  */
3751                                 yaffs_DeleteChunk(dev, existingChunk, 1,
3752                                                   __LINE__);
3753                         } else {
3754                                 /* Backward scanning or we want to use the existing one
3755                                  * Use existing.
3756                                  * Delete the new one and return early so that the tnode isn't changed
3757                                  */
3758                                 yaffs_DeleteChunk(dev, chunkInNAND, 1,
3759                                                   __LINE__);
3760                                 return YAFFS_OK;
3761                         }
3762                 }
3763
3764         }
3765
3766         if (existingChunk == 0)
3767                 in->nDataChunks++;
3768
3769         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, chunkInNAND);
3770
3771         return YAFFS_OK;
3772 }
3773
3774 static int yaffs_ReadChunkDataFromObject(yaffs_Object *in, int chunkInInode,
3775                                         __u8 *buffer)
3776 {
3777         int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);
3778
3779         if (chunkInNAND >= 0)
3780                 return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
3781                                                 buffer, NULL);
3782         else {
3783                 T(YAFFS_TRACE_NANDACCESS,
3784                   (TSTR("Chunk %d not found zero instead" TENDSTR),
3785                    chunkInNAND));
3786                 /* get sane (zero) data if you read a hole */
3787                 memset(buffer, 0, in->myDev->nDataBytesPerChunk);
3788                 return 0;
3789         }
3790
3791 }
3792
3793 void yaffs_DeleteChunk(yaffs_Device *dev, int chunkId, int markNAND, int lyn)
3794 {
3795         int block;
3796         int page;
3797         yaffs_ExtendedTags tags;
3798         yaffs_BlockInfo *bi;
3799
3800         if (chunkId <= 0)
3801                 return;
3802
3803         dev->nDeletions++;
3804         block = chunkId / dev->param.nChunksPerBlock;
3805         page = chunkId % dev->param.nChunksPerBlock;
3806
3807
3808         if (!yaffs_CheckChunkBit(dev, block, page))
3809                 T(YAFFS_TRACE_VERIFY,
3810                         (TSTR("Deleting invalid chunk %d"TENDSTR),
3811                          chunkId));
3812
3813         bi = yaffs_GetBlockInfo(dev, block);
3814         
3815         yaffs_UpdateOldestDirtySequence(dev,bi);
3816
3817         T(YAFFS_TRACE_DELETION,
3818           (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
3819
3820         if (markNAND &&
3821             bi->blockState != YAFFS_BLOCK_STATE_COLLECTING && !dev->param.isYaffs2) {
3822
3823                 yaffs_InitialiseTags(&tags);
3824
3825                 tags.chunkDeleted = 1;
3826
3827                 yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
3828                 yaffs_HandleUpdateChunk(dev, chunkId, &tags);
3829         } else {
3830                 dev->nUnmarkedDeletions++;
3831         }
3832
3833         /* Pull out of the management area.
3834          * If the whole block became dirty, this will kick off an erasure.
3835          */
3836         if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
3837             bi->blockState == YAFFS_BLOCK_STATE_FULL ||
3838             bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
3839             bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
3840                 dev->nFreeChunks++;
3841
3842                 yaffs_ClearChunkBit(dev, block, page);
3843
3844                 bi->pagesInUse--;
3845
3846                 if (bi->pagesInUse == 0 &&
3847                     !bi->hasShrinkHeader &&
3848                     bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
3849                     bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
3850                         yaffs_BlockBecameDirty(dev, block);
3851                 }
3852
3853         }
3854
3855 }
3856
3857 static int yaffs_WriteChunkDataToObject(yaffs_Object *in, int chunkInInode,
3858                                         const __u8 *buffer, int nBytes,
3859                                         int useReserve)
3860 {
3861         /* Find old chunk Need to do this to get serial number
3862          * Write new one and patch into tree.
3863          * Invalidate old tags.
3864          */
3865
3866         int prevChunkId;
3867         yaffs_ExtendedTags prevTags;
3868
3869         int newChunkId;
3870         yaffs_ExtendedTags newTags;
3871
3872         yaffs_Device *dev = in->myDev;
3873
3874         yaffs_CheckGarbageCollection(dev);
3875
3876         /* Get the previous chunk at this location in the file if it exists.
3877          * If it does not exist then put a zero into the tree. This creates
3878          * the tnode now, rather than later when it is harder to clean up.
3879          */
3880         prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);
3881         if(prevChunkId < 1 &&
3882                 !yaffs_PutChunkIntoFile(in, chunkInInode, 0, 0))
3883                 return 0;
3884
3885         /* Set up new tags */
3886         yaffs_InitialiseTags(&newTags);
3887
3888         newTags.chunkId = chunkInInode;
3889         newTags.objectId = in->objectId;
3890         newTags.serialNumber =
3891             (prevChunkId > 0) ? prevTags.serialNumber + 1 : 1;
3892         newTags.byteCount = nBytes;
3893
3894         if (nBytes < 1 || nBytes > dev->param.totalBytesPerChunk) {
3895                 T(YAFFS_TRACE_ERROR,
3896                 (TSTR("Writing %d bytes to chunk!!!!!!!!!" TENDSTR), nBytes));
3897                 YBUG();
3898         }
3899         
3900                 
3901         newChunkId =
3902             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3903                                               useReserve);
3904
3905         if (newChunkId > 0) {
3906                 yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);
3907
3908                 if (prevChunkI