Some fixes and add NOR integrity code
[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 1.62 2008-11-07 00:32:20 charles Exp $";
16
17 #include "yportenv.h"
18
19 #include "yaffsinterface.h"
20 #include "yaffs_guts.h"
21 #include "yaffs_tagsvalidity.h"
22 #include "yaffs_getblockinfo.h"
23
24 #include "yaffs_tagscompat.h"
25 #ifndef  CONFIG_YAFFS_USE_OWN_SORT
26 #include "yaffs_qsort.h"
27 #endif
28 #include "yaffs_nand.h"
29
30 #include "yaffs_checkptrw.h"
31
32 #include "yaffs_nand.h"
33 #include "yaffs_packedtags2.h"
34
35
36 #ifdef CONFIG_YAFFS_WINCE
37 void yfsd_LockYAFFS(BOOL fsLockOnly);
38 void yfsd_UnlockYAFFS(BOOL fsLockOnly);
39 #endif
40
41 #define YAFFS_PASSIVE_GC_CHUNKS 2
42
43 #include "yaffs_ecc.h"
44
45
46 /* Robustification (if it ever comes about...) */
47 static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND);
48 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk);
49 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
50                                      const __u8 * data,
51                                      const yaffs_ExtendedTags * tags);
52 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
53                                     const yaffs_ExtendedTags * tags);
54
55 /* Other local prototypes */
56 static int yaffs_UnlinkObject( yaffs_Object *obj);
57 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);
58
59 static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList);
60
61 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device * dev,
62                                              const __u8 * buffer,
63                                              yaffs_ExtendedTags * tags,
64                                              int useReserve);
65 static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
66                                   int chunkInNAND, int inScan);
67
68 static yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
69                                            yaffs_ObjectType type);
70 static void yaffs_AddObjectToDirectory(yaffs_Object * directory,
71                                        yaffs_Object * obj);
72 static int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name,
73                                     int force, int isShrink, int shadows);
74 static void yaffs_RemoveObjectFromDirectory(yaffs_Object * obj);
75 static int yaffs_CheckStructures(void);
76 static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
77                               int chunkOffset, int *limit);
78 static int yaffs_DoGenericObjectDeletion(yaffs_Object * in);
79
80 static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device * dev, int blockNo);
81
82
83 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
84                                   int chunkInNAND);
85
86 static int yaffs_UnlinkWorker(yaffs_Object * obj);
87 static void yaffs_DestroyObject(yaffs_Object * obj);
88
89 static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
90                            int chunkInObject);
91
92 loff_t yaffs_GetFileSize(yaffs_Object * obj);
93
94 static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr);
95
96 static void yaffs_VerifyFreeChunks(yaffs_Device * dev);
97
98 static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
99
100 static void yaffs_VerifyDirectory(yaffs_Object *directory);
101 #ifdef YAFFS_PARANOID
102 static int yaffs_CheckFileSanity(yaffs_Object * in);
103 #else
104 #define yaffs_CheckFileSanity(in)
105 #endif
106
107 static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in);
108 static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId);
109
110 static void yaffs_InvalidateCheckpoint(yaffs_Device *dev);
111
112 static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
113                                  yaffs_ExtendedTags * tags);
114
115 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos);
116 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
117                                           yaffs_FileStructure * fStruct,
118                                           __u32 chunkId);
119
120
121 /* Function to calculate chunk and offset */
122
123 static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, int *chunkOut, __u32 *offsetOut)
124 {
125         int chunk;
126         __u32 offset;
127         
128         chunk  = (__u32)(addr >> dev->chunkShift);
129                 
130         if(dev->chunkDiv == 1)
131         {
132                 /* easy power of 2 case */
133                 offset = (__u32)(addr & dev->chunkMask);
134         }
135         else
136         {
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 equal 
152  * 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) extraBits++;
166                 x>>=1;
167                 nShifts++;
168         }
169
170         if(extraBits) 
171                 nShifts++;
172                 
173         return nShifts;
174 }
175
176 /* Function to return the number of shifts to get a 1 in bit 0
177  */
178  
179 static __u32 Shifts(__u32 x)
180 {
181         int nShifts;
182         
183         nShifts =  0;
184         
185         if(!x) return 0;
186         
187         while( !(x&1)){
188                 x>>=1;
189                 nShifts++;
190         }
191                 
192         return nShifts;
193 }
194
195
196
197 /* 
198  * Temporary buffer manipulations.
199  */
200
201 static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)       
202 {
203         int i;
204         __u8 *buf = (__u8 *)1;
205                 
206         memset(dev->tempBuffer,0,sizeof(dev->tempBuffer));
207                 
208         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
209                 dev->tempBuffer[i].line = 0;    /* not in use */
210                 dev->tempBuffer[i].buffer = buf =
211                     YMALLOC_DMA(dev->totalBytesPerChunk);
212         }
213                 
214         return buf ? YAFFS_OK : YAFFS_FAIL;
215         
216 }
217
218 __u8 *yaffs_GetTempBuffer(yaffs_Device * dev, int lineNo)
219 {
220         int i, j;
221
222         dev->tempInUse++;
223         if(dev->tempInUse > dev->maxTemp)
224                 dev->maxTemp = dev->tempInUse;
225
226         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
227                 if (dev->tempBuffer[i].line == 0) {
228                         dev->tempBuffer[i].line = lineNo;
229                         if ((i + 1) > dev->maxTemp) {
230                                 dev->maxTemp = i + 1;
231                                 for (j = 0; j <= i; j++)
232                                         dev->tempBuffer[j].maxLine =
233                                             dev->tempBuffer[j].line;
234                         }
235
236                         return dev->tempBuffer[i].buffer;
237                 }
238         }
239
240         T(YAFFS_TRACE_BUFFERS,
241           (TSTR("Out of temp buffers at line %d, other held by lines:"),
242            lineNo));
243         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
244                 T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
245         }
246         T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
247
248         /*
249          * If we got here then we have to allocate an unmanaged one
250          * This is not good.
251          */
252
253         dev->unmanagedTempAllocations++;
254         return YMALLOC(dev->nDataBytesPerChunk);
255
256 }
257
258 void yaffs_ReleaseTempBuffer(yaffs_Device * dev, __u8 * buffer,
259                                     int lineNo)
260 {
261         int i;
262         
263         dev->tempInUse--;
264         
265         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
266                 if (dev->tempBuffer[i].buffer == buffer) {
267                         dev->tempBuffer[i].line = 0;
268                         return;
269                 }
270         }
271
272         if (buffer) {
273                 /* assume it is an unmanaged one. */
274                 T(YAFFS_TRACE_BUFFERS,
275                   (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
276                    lineNo));
277                 YFREE(buffer);
278                 dev->unmanagedTempDeallocations++;
279         }
280
281 }
282
283 /*
284  * Determine if we have a managed buffer.
285  */
286 int yaffs_IsManagedTempBuffer(yaffs_Device * dev, const __u8 * buffer)
287 {
288         int i;
289         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
290                 if (dev->tempBuffer[i].buffer == buffer)
291                         return 1;
292
293         }
294
295     for (i = 0; i < dev->nShortOpCaches; i++) {
296         if( dev->srCache[i].data == buffer )
297             return 1;
298
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->nChunksPerBlock) {
331            T(YAFFS_TRACE_ERROR,
332             (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),blk,chunk));
333             YBUG();
334         }
335 }
336
337 static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device * dev, int blk)
338 {
339         __u8 *blkBits = yaffs_BlockBits(dev, blk);
340
341         memset(blkBits, 0, dev->chunkBitmapStride);
342 }
343
344 static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device * dev, int blk, int chunk)
345 {
346         __u8 *blkBits = yaffs_BlockBits(dev, blk);
347
348         yaffs_VerifyChunkBitId(dev,blk,chunk);
349
350         blkBits[chunk / 8] &= ~(1 << (chunk & 7));
351 }
352
353 static Y_INLINE void yaffs_SetChunkBit(yaffs_Device * dev, int blk, int chunk)
354 {
355         __u8 *blkBits = yaffs_BlockBits(dev, blk);
356         
357         yaffs_VerifyChunkBitId(dev,blk,chunk);
358
359         blkBits[chunk / 8] |= (1 << (chunk & 7));
360 }
361
362 static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device * dev, int blk, int chunk)
363 {
364         __u8 *blkBits = yaffs_BlockBits(dev, blk);
365         yaffs_VerifyChunkBitId(dev,blk,chunk);
366
367         return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
368 }
369
370 static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device * dev, int blk)
371 {
372         __u8 *blkBits = yaffs_BlockBits(dev, blk);
373         int i;
374         for (i = 0; i < dev->chunkBitmapStride; i++) {
375                 if (*blkBits)
376                         return 1;
377                 blkBits++;
378         }
379         return 0;
380 }
381
382 static int yaffs_CountChunkBits(yaffs_Device * dev, int blk)
383 {
384         __u8 *blkBits = yaffs_BlockBits(dev, blk);
385         int i;
386         int n = 0;
387         for (i = 0; i < dev->chunkBitmapStride; i++) {
388                 __u8 x = *blkBits;
389                 while(x){
390                         if(x & 1)
391                                 n++;
392                         x >>=1;
393                 }
394                         
395                 blkBits++;
396         }
397         return n;
398 }
399
400 /* 
401  * Verification code
402  */
403  
404 static int yaffs_SkipVerification(yaffs_Device *dev)
405 {
406         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
407 }
408
409 #if 0
410 static int yaffs_SkipFullVerification(yaffs_Device *dev)
411 {
412         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_FULL));
413 }
414
415 #endif
416
417 static int yaffs_SkipNANDVerification(yaffs_Device *dev)
418 {
419         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_NAND));
420 }
421
422 static const char * blockStateName[] = {
423 "Unknown",
424 "Needs scanning",
425 "Scanning",
426 "Empty",
427 "Allocating",
428 "Full",
429 "Dirty",
430 "Checkpoint",
431 "Collecting",
432 "Dead"
433 };
434
435 static void yaffs_VerifyBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
436 {
437         int actuallyUsed;
438         int inUse;
439         
440         if(yaffs_SkipVerification(dev))
441                 return;
442                 
443         /* Report illegal runtime states */
444         if(bi->blockState >= YAFFS_NUMBER_OF_BLOCK_STATES)
445                 T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has undefined state %d"TENDSTR),n,bi->blockState));
446                 
447         switch(bi->blockState){
448          case YAFFS_BLOCK_STATE_UNKNOWN:
449          case YAFFS_BLOCK_STATE_SCANNING:
450          case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
451                 T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has bad run-state %s"TENDSTR),
452                 n,blockStateName[bi->blockState]));
453         }
454         
455         /* Check pages in use and soft deletions are legal */
456         
457         actuallyUsed = bi->pagesInUse - bi->softDeletions;
458         
459         if(bi->pagesInUse < 0 || bi->pagesInUse > dev->nChunksPerBlock ||
460            bi->softDeletions < 0 || bi->softDeletions > dev->nChunksPerBlock ||
461            actuallyUsed < 0 || actuallyUsed > dev->nChunksPerBlock)
462                 T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has illegal values pagesInUsed %d softDeletions %d"TENDSTR),
463                 n,bi->pagesInUse,bi->softDeletions));
464         
465                 
466         /* Check chunk bitmap legal */
467         inUse = yaffs_CountChunkBits(dev,n);
468         if(inUse != bi->pagesInUse)
469                 T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has inconsistent values pagesInUse %d counted chunk bits %d"TENDSTR),
470                         n,bi->pagesInUse,inUse));
471         
472         /* Check that the sequence number is valid.
473          * Ten million is legal, but is very unlikely 
474          */
475         if(dev->isYaffs2 && 
476            (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING || bi->blockState == YAFFS_BLOCK_STATE_FULL) &&
477            (bi->sequenceNumber < YAFFS_LOWEST_SEQUENCE_NUMBER || bi->sequenceNumber > 10000000 ))
478                 T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has suspect sequence number of %d"TENDSTR),
479                 n,bi->sequenceNumber));
480                 
481 }
482
483 static void yaffs_VerifyCollectedBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
484 {
485         yaffs_VerifyBlock(dev,bi,n);
486         
487         /* After collection the block should be in the erased state */
488         /* TODO: This will need to change if we do partial gc */
489         
490         if(bi->blockState != YAFFS_BLOCK_STATE_EMPTY){
491                 T(YAFFS_TRACE_ERROR,(TSTR("Block %d is in state %d after gc, should be erased"TENDSTR),
492                         n,bi->blockState));
493         }
494 }
495
496 static void yaffs_VerifyBlocks(yaffs_Device *dev)
497 {
498         int i;
499         int nBlocksPerState[YAFFS_NUMBER_OF_BLOCK_STATES];
500         int nIllegalBlockStates = 0;
501         
502
503         if(yaffs_SkipVerification(dev))
504                 return;
505
506         memset(nBlocksPerState,0,sizeof(nBlocksPerState));
507
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         
520         T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
521         T(YAFFS_TRACE_VERIFY,(TSTR("Block summary"TENDSTR)));
522         
523         T(YAFFS_TRACE_VERIFY,(TSTR("%d blocks have illegal states"TENDSTR),nIllegalBlockStates));
524         if(nBlocksPerState[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
525                 T(YAFFS_TRACE_VERIFY,(TSTR("Too many allocating blocks"TENDSTR)));
526
527         for(i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
528                 T(YAFFS_TRACE_VERIFY,
529                   (TSTR("%s %d blocks"TENDSTR),
530                   blockStateName[i],nBlocksPerState[i]));
531         
532         if(dev->blocksInCheckpoint != nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT])
533                 T(YAFFS_TRACE_VERIFY,
534                  (TSTR("Checkpoint block count wrong dev %d count %d"TENDSTR),
535                  dev->blocksInCheckpoint, nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT]));
536                  
537         if(dev->nErasedBlocks != nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY])
538                 T(YAFFS_TRACE_VERIFY,
539                  (TSTR("Erased block count wrong dev %d count %d"TENDSTR),
540                  dev->nErasedBlocks, nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY]));
541                  
542         if(nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
543                 T(YAFFS_TRACE_VERIFY,
544                  (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
545                  nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));
546
547         T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
548
549 }
550
551 /*
552  * Verify the object header. oh must be valid, but obj and tags may be NULL in which
553  * case those tests will not be performed.
554  */
555 static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
556 {
557         if(obj && yaffs_SkipVerification(obj->myDev))
558                 return;
559                 
560         if(!(tags && obj && oh)){
561                 T(YAFFS_TRACE_VERIFY,
562                                 (TSTR("Verifying object header tags %x obj %x oh %x"TENDSTR),
563                                 (__u32)tags,(__u32)obj,(__u32)oh));
564                 return;
565         }
566         
567         if(oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
568            oh->type > YAFFS_OBJECT_TYPE_MAX)
569                 T(YAFFS_TRACE_VERIFY,
570                  (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
571                  tags->objectId, oh->type));
572
573         if(tags->objectId != obj->objectId)
574                 T(YAFFS_TRACE_VERIFY,
575                  (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
576                  tags->objectId, obj->objectId));
577
578
579         /*
580          * Check that the object's parent ids match if parentCheck requested.
581          * 
582          * Tests do not apply to the root object.
583          */
584         
585         if(parentCheck && tags->objectId > 1 && !obj->parent)
586                 T(YAFFS_TRACE_VERIFY,
587                  (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
588                  tags->objectId, oh->parentObjectId));
589                 
590         
591         if(parentCheck && obj->parent &&
592            oh->parentObjectId != obj->parent->objectId && 
593            (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
594             obj->parent->objectId != YAFFS_OBJECTID_DELETED))
595                 T(YAFFS_TRACE_VERIFY,
596                  (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
597                  tags->objectId, oh->parentObjectId, obj->parent->objectId));
598                 
599         
600         if(tags->objectId > 1 && oh->name[0] == 0) /* Null name */
601                 T(YAFFS_TRACE_VERIFY,
602                 (TSTR("Obj %d header name is NULL"TENDSTR),
603                  obj->objectId));
604
605         if(tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
606                 T(YAFFS_TRACE_VERIFY,
607                 (TSTR("Obj %d header name is 0xFF"TENDSTR),
608                  obj->objectId));
609 }
610
611
612
613 static int yaffs_VerifyTnodeWorker(yaffs_Object * obj, yaffs_Tnode * tn,
614                                         __u32 level, int chunkOffset)
615 {
616         int i;
617         yaffs_Device *dev = obj->myDev;
618         int ok = 1;
619
620         if (tn) {
621                 if (level > 0) {
622
623                         for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++){
624                                 if (tn->internal[i]) {
625                                         ok = yaffs_VerifyTnodeWorker(obj,
626                                                         tn->internal[i],
627                                                         level - 1,
628                                                         (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
629                                 }
630                         }
631                 } else if (level == 0) {
632                         yaffs_ExtendedTags tags;
633                         __u32 objectId = obj->objectId;
634                         
635                         chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
636                         
637                         for(i = 0; i < YAFFS_NTNODES_LEVEL0; i++){
638                                 __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
639                                 
640                                 if(theChunk > 0){
641                                         /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
642                                         yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
643                                         if(tags.objectId != objectId || tags.chunkId != chunkOffset){
644                                                 T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
645                                                         objectId, chunkOffset, theChunk,
646                                                         tags.objectId, tags.chunkId));
647                                         }
648                                 }
649                                 chunkOffset++;
650                         }
651                 }
652         }
653
654         return ok;
655
656 }
657
658
659 static void yaffs_VerifyFile(yaffs_Object *obj)
660 {
661         int requiredTallness;
662         int actualTallness;
663         __u32 lastChunk;
664         __u32 x;
665         __u32 i;
666         yaffs_Device *dev;
667         yaffs_ExtendedTags tags;
668         yaffs_Tnode *tn;
669         __u32 objectId;
670         
671         if(!obj)
672                 return;
673
674         if(yaffs_SkipVerification(obj->myDev))
675                 return;
676         
677         dev = obj->myDev;
678         objectId = obj->objectId;
679         
680         /* Check file size is consistent with tnode depth */
681         lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
682         x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
683         requiredTallness = 0;
684         while (x> 0) {
685                 x >>= YAFFS_TNODES_INTERNAL_BITS;
686                 requiredTallness++;
687         }
688         
689         actualTallness = obj->variant.fileVariant.topLevel;
690         
691         if(requiredTallness > actualTallness )
692                 T(YAFFS_TRACE_VERIFY,
693                 (TSTR("Obj %d had tnode tallness %d, needs to be %d"TENDSTR),
694                  obj->objectId,actualTallness, requiredTallness));
695         
696         
697         /* Check that the chunks in the tnode tree are all correct. 
698          * We do this by scanning through the tnode tree and
699          * checking the tags for every chunk match.
700          */
701
702         if(yaffs_SkipNANDVerification(dev))
703                 return;
704                 
705         for(i = 1; i <= lastChunk; i++){
706                 tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant,i);
707
708                 if (tn) {
709                         __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
710                         if(theChunk > 0){
711                                 /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
712                                 yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
713                                 if(tags.objectId != objectId || tags.chunkId != i){
714                                         T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
715                                                 objectId, i, theChunk,
716                                                 tags.objectId, tags.chunkId));
717                                 }
718                         }
719                 }
720
721         }
722
723 }
724
725
726 static void yaffs_VerifyHardLink(yaffs_Object *obj)
727 {
728         if(obj && yaffs_SkipVerification(obj->myDev))
729                 return;
730                 
731         /* Verify sane equivalent object */
732 }
733
734 static void yaffs_VerifySymlink(yaffs_Object *obj)
735 {
736         if(obj && yaffs_SkipVerification(obj->myDev))
737                 return;
738                 
739         /* Verify symlink string */
740 }
741
742 static void yaffs_VerifySpecial(yaffs_Object *obj)
743 {
744         if(obj && yaffs_SkipVerification(obj->myDev))
745                 return;
746 }
747
748 static void yaffs_VerifyObject(yaffs_Object *obj)
749 {
750         yaffs_Device *dev;
751         
752         __u32 chunkMin;
753         __u32 chunkMax;
754         
755         __u32 chunkIdOk;
756         __u32 chunkIsLive;
757         
758         if(!obj)
759                 return;
760         
761         dev = obj->myDev;
762         
763         if(yaffs_SkipVerification(dev))
764                 return;
765                 
766         /* Check sane object header chunk */
767
768         chunkMin = dev->internalStartBlock * dev->nChunksPerBlock;
769         chunkMax = (dev->internalEndBlock+1) * dev->nChunksPerBlock - 1;
770
771         chunkIdOk = (((unsigned)(obj->hdrChunk)) >= chunkMin && ((unsigned)(obj->hdrChunk)) <= chunkMax);
772         chunkIsLive = chunkIdOk &&
773                         yaffs_CheckChunkBit(dev,
774                                             obj->hdrChunk / dev->nChunksPerBlock,
775                                             obj->hdrChunk % dev->nChunksPerBlock);
776         if(!obj->fake &&
777             (!chunkIdOk || !chunkIsLive)) {
778            T(YAFFS_TRACE_VERIFY,
779            (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
780            obj->objectId,obj->hdrChunk,
781            chunkIdOk ? "" : ",out of range",
782            chunkIsLive || !chunkIdOk ? "" : ",marked as deleted"));
783         }
784         
785         if(chunkIdOk && chunkIsLive &&!yaffs_SkipNANDVerification(dev)) {
786                 yaffs_ExtendedTags tags;
787                 yaffs_ObjectHeader *oh;
788                 __u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
789                 
790                 oh = (yaffs_ObjectHeader *)buffer;
791
792                 yaffs_ReadChunkWithTagsFromNAND(dev, obj->hdrChunk,buffer, &tags);
793
794                 yaffs_VerifyObjectHeader(obj,oh,&tags,1);
795                 
796                 yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
797         }
798         
799         /* Verify it has a parent */
800         if(obj && !obj->fake &&
801            (!obj->parent || obj->parent->myDev != dev)){
802            T(YAFFS_TRACE_VERIFY,
803            (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
804            obj->objectId,obj->parent));    
805         }
806         
807         /* Verify parent is a directory */
808         if(obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY){
809            T(YAFFS_TRACE_VERIFY,
810            (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
811            obj->objectId,obj->parent->variantType));       
812         }
813         
814         switch(obj->variantType){
815         case YAFFS_OBJECT_TYPE_FILE:
816                 yaffs_VerifyFile(obj);
817                 break;
818         case YAFFS_OBJECT_TYPE_SYMLINK:
819                 yaffs_VerifySymlink(obj);
820                 break;
821         case YAFFS_OBJECT_TYPE_DIRECTORY:
822                 yaffs_VerifyDirectory(obj);
823                 break;
824         case YAFFS_OBJECT_TYPE_HARDLINK:
825                 yaffs_VerifyHardLink(obj);
826                 break;
827         case YAFFS_OBJECT_TYPE_SPECIAL:
828                 yaffs_VerifySpecial(obj);
829                 break;
830         case YAFFS_OBJECT_TYPE_UNKNOWN:
831         default:
832                 T(YAFFS_TRACE_VERIFY,
833                 (TSTR("Obj %d has illegaltype %d"TENDSTR),
834                 obj->objectId,obj->variantType));          
835                 break;
836         }
837         
838         
839 }
840
841 static void yaffs_VerifyObjects(yaffs_Device *dev)
842 {
843         yaffs_Object *obj;
844         int i;
845         struct ylist_head *lh;
846
847         if(yaffs_SkipVerification(dev))
848                 return;
849         
850         /* Iterate through the objects in each hash entry */
851          
852          for(i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++){
853                 ylist_for_each(lh, &dev->objectBucket[i].list) {
854                         if (lh) {
855                                 obj = ylist_entry(lh, yaffs_Object, hashLink);
856                                 yaffs_VerifyObject(obj);
857                         }
858                 }
859          }
860
861 }
862
863
864 /*
865  *  Simple hash function. Needs to have a reasonable spread
866  */
867  
868 static Y_INLINE int yaffs_HashFunction(int n)
869 {
870         n = abs(n);
871         return (n % YAFFS_NOBJECT_BUCKETS);
872 }
873
874 /*
875  * Access functions to useful fake objects.
876  * Note that root might have a presence in NAND if permissions are set.
877  */
878  
879 yaffs_Object *yaffs_Root(yaffs_Device * dev)
880 {
881         return dev->rootDir;
882 }
883
884 yaffs_Object *yaffs_LostNFound(yaffs_Device * dev)
885 {
886         return dev->lostNFoundDir;
887 }
888
889
890 /*
891  *  Erased NAND checking functions
892  */
893  
894 int yaffs_CheckFF(__u8 * buffer, int nBytes)
895 {
896         /* Horrible, slow implementation */
897         while (nBytes--) {
898                 if (*buffer != 0xFF)
899                         return 0;
900                 buffer++;
901         }
902         return 1;
903 }
904
905 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
906                                   int chunkInNAND)
907 {
908
909         int retval = YAFFS_OK;
910         __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
911         yaffs_ExtendedTags tags;
912         int result;
913
914         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
915         
916         if(tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
917                 retval = YAFFS_FAIL;
918                 
919
920         if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
921                 T(YAFFS_TRACE_NANDACCESS,
922                   (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
923                 retval = YAFFS_FAIL;
924         }
925
926         yaffs_ReleaseTempBuffer(dev, data, __LINE__);
927
928         return retval;
929
930 }
931
932 static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
933                                              const __u8 * data,
934                                              yaffs_ExtendedTags * tags,
935                                              int useReserve)
936 {
937         int attempts = 0;
938         int writeOk = 0;
939         int chunk;
940
941         yaffs_InvalidateCheckpoint(dev);
942
943         do {
944                 yaffs_BlockInfo *bi = 0;
945                 int erasedOk = 0;
946
947                 chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
948                 if (chunk < 0) {
949                         /* no space */
950                         break;
951                 }
952
953                 /* First check this chunk is erased, if it needs
954                  * checking.  The checking policy (unless forced
955                  * always on) is as follows:
956                  *
957                  * Check the first page we try to write in a block.
958                  * If the check passes then we don't need to check any
959                  * more.        If the check fails, we check again...
960                  * If the block has been erased, we don't need to check.
961                  *
962                  * However, if the block has been prioritised for gc,
963                  * then we think there might be something odd about
964                  * this block and stop using it.
965                  *
966                  * Rationale: We should only ever see chunks that have
967                  * not been erased if there was a partially written
968                  * chunk due to power loss.  This checking policy should
969                  * catch that case with very few checks and thus save a
970                  * lot of checks that are most likely not needed.
971                  */
972                 if (bi->gcPrioritise) {
973                         yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
974                         /* try another chunk */
975                         continue;
976                 }
977
978                 /* let's give it a try */
979                 attempts++;
980
981 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
982                 bi->skipErasedCheck = 0;
983 #endif
984                 if (!bi->skipErasedCheck) {
985                         erasedOk = yaffs_CheckChunkErased(dev, chunk);
986                         if (erasedOk != YAFFS_OK) {
987                                 T(YAFFS_TRACE_ERROR,
988                                 (TSTR ("**>> yaffs chunk %d was not erased"
989                                 TENDSTR), chunk));
990
991                                 /* try another chunk */
992                                 continue;
993                         }
994                         bi->skipErasedCheck = 1;
995                 }
996
997                 writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
998                                 data, tags);
999                 if (writeOk != YAFFS_OK) {
1000                         yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
1001                         /* try another chunk */
1002                         continue;
1003                 }
1004
1005                 /* Copy the data into the robustification buffer */
1006                 yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
1007
1008         } while (writeOk != YAFFS_OK && 
1009                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
1010         
1011         if(!writeOk)
1012                 chunk = -1;
1013
1014         if (attempts > 1) {
1015                 T(YAFFS_TRACE_ERROR,
1016                         (TSTR("**>> yaffs write required %d attempts" TENDSTR),
1017                         attempts));
1018
1019                 dev->nRetriedWrites += (attempts - 1);
1020         }
1021
1022         return chunk;
1023 }
1024
1025 /*
1026  * Block retiring for handling a broken block.
1027  */
1028  
1029 static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND)
1030 {
1031         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1032
1033         yaffs_InvalidateCheckpoint(dev);
1034         
1035         yaffs_MarkBlockBad(dev, blockInNAND);
1036
1037         bi->blockState = YAFFS_BLOCK_STATE_DEAD;
1038         bi->gcPrioritise = 0;
1039         bi->needsRetiring = 0;
1040
1041         dev->nRetiredBlocks++;
1042 }
1043
1044 /*
1045  * Functions for robustisizing TODO
1046  *
1047  */
1048  
1049 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
1050                                      const __u8 * data,
1051                                      const yaffs_ExtendedTags * tags)
1052 {
1053 }
1054
1055 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
1056                                     const yaffs_ExtendedTags * tags)
1057 {
1058 }
1059
1060 void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
1061 {
1062         if(!bi->gcPrioritise){
1063                 bi->gcPrioritise = 1;
1064                 dev->hasPendingPrioritisedGCs = 1;
1065                 bi->chunkErrorStrikes ++;
1066                 
1067                 if(bi->chunkErrorStrikes > 3){
1068                         bi->needsRetiring = 1; /* Too many stikes, so retire this */
1069                         T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));
1070
1071                 }
1072                 
1073         }
1074 }
1075
1076 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk)
1077 {
1078
1079         int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
1080         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1081
1082         yaffs_HandleChunkError(dev,bi);
1083                 
1084         
1085         if(erasedOk ) {
1086                 /* Was an actual write failure, so mark the block for retirement  */
1087                 bi->needsRetiring = 1;
1088                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
1089                   (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));
1090
1091                 
1092         }
1093         
1094         /* Delete the chunk */
1095         yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
1096 }
1097
1098
1099 /*---------------- Name handling functions ------------*/ 
1100
1101 static __u16 yaffs_CalcNameSum(const YCHAR * name)
1102 {
1103         __u16 sum = 0;
1104         __u16 i = 1;
1105
1106         const YUCHAR *bname = (const YUCHAR *) name;
1107         if (bname) {
1108                 while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
1109
1110 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
1111                         sum += yaffs_toupper(*bname) * i;
1112 #else
1113                         sum += (*bname) * i;
1114 #endif
1115                         i++;
1116                         bname++;
1117                 }
1118         }
1119         
1120         return sum;
1121 }
1122
1123 static void yaffs_SetObjectName(yaffs_Object * obj, const YCHAR * name)
1124 {
1125 #ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
1126         memset(obj->shortName,0,sizeof (YCHAR) * (YAFFS_SHORT_NAME_LENGTH+1)); 
1127         if (name && yaffs_strlen(name) <= YAFFS_SHORT_NAME_LENGTH) {
1128                 yaffs_strcpy(obj->shortName, name);
1129         } else {
1130                 obj->shortName[0] = _Y('\0');
1131         }
1132 #endif
1133         obj->sum = yaffs_CalcNameSum(name);
1134 }
1135
1136 /*-------------------- TNODES -------------------
1137
1138  * List of spare tnodes
1139  * The list is hooked together using the first pointer
1140  * in the tnode.
1141  */
1142  
1143 /* yaffs_CreateTnodes creates a bunch more tnodes and
1144  * adds them to the tnode free list.
1145  * Don't use this function directly
1146  */
1147
1148 static int yaffs_CreateTnodes(yaffs_Device * dev, int nTnodes)
1149 {
1150         int i;
1151         int tnodeSize;
1152         yaffs_Tnode *newTnodes;
1153         __u8 *mem;
1154         yaffs_Tnode *curr;
1155         yaffs_Tnode *next;
1156         yaffs_TnodeList *tnl;
1157
1158         if (nTnodes < 1)
1159                 return YAFFS_OK;
1160                 
1161         /* Calculate the tnode size in bytes for variable width tnode support.
1162          * Must be a multiple of 32-bits  */
1163         tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
1164
1165         if(tnodeSize < sizeof(yaffs_Tnode))
1166                 tnodeSize = sizeof(yaffs_Tnode);
1167                 
1168
1169         /* make these things */
1170
1171         newTnodes = YMALLOC(nTnodes * tnodeSize);
1172         mem = (__u8 *)newTnodes;
1173
1174         if (!newTnodes) {
1175                 T(YAFFS_TRACE_ERROR,
1176                   (TSTR("yaffs: Could not allocate Tnodes" TENDSTR)));
1177                 return YAFFS_FAIL;
1178         }
1179
1180         /* Hook them into the free list */
1181 #if 0
1182         for (i = 0; i < nTnodes - 1; i++) {
1183                 newTnodes[i].internal[0] = &newTnodes[i + 1];
1184 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1185                 newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1186 #endif
1187         }
1188
1189         newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
1190 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1191         newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1192 #endif
1193         dev->freeTnodes = newTnodes;
1194 #else
1195         /* New hookup for wide tnodes */
1196         for(i = 0; i < nTnodes -1; i++) {
1197                 curr = (yaffs_Tnode *) &mem[i * tnodeSize];
1198                 next = (yaffs_Tnode *) &mem[(i+1) * tnodeSize];
1199                 curr->internal[0] = next;
1200         }
1201         
1202         curr = (yaffs_Tnode *) &mem[(nTnodes - 1) * tnodeSize];
1203         curr->internal[0] = dev->freeTnodes;
1204         dev->freeTnodes = (yaffs_Tnode *)mem;
1205
1206 #endif
1207
1208
1209         dev->nFreeTnodes += nTnodes;
1210         dev->nTnodesCreated += nTnodes;
1211
1212         /* Now add this bunch of tnodes to a list for freeing up.
1213          * NB If we can't add this to the management list it isn't fatal
1214          * but it just means we can't free this bunch of tnodes later.
1215          */
1216          
1217         tnl = YMALLOC(sizeof(yaffs_TnodeList));
1218         if (!tnl) {
1219                 T(YAFFS_TRACE_ERROR,
1220                   (TSTR
1221                    ("yaffs: Could not add tnodes to management list" TENDSTR)));
1222                    return YAFFS_FAIL;
1223
1224         } else {
1225                 tnl->tnodes = newTnodes;
1226                 tnl->next = dev->allocatedTnodeList;
1227                 dev->allocatedTnodeList = tnl;
1228         }
1229
1230         T(YAFFS_TRACE_ALLOCATE, (TSTR("yaffs: Tnodes added" TENDSTR)));
1231
1232         return YAFFS_OK;
1233 }
1234
1235 /* GetTnode gets us a clean tnode. Tries to make allocate more if we run out */
1236
1237 static yaffs_Tnode *yaffs_GetTnodeRaw(yaffs_Device * dev)
1238 {
1239         yaffs_Tnode *tn = NULL;
1240
1241         /* If there are none left make more */
1242         if (!dev->freeTnodes) {
1243                 yaffs_CreateTnodes(dev, YAFFS_ALLOCATION_NTNODES);
1244         }
1245
1246         if (dev->freeTnodes) {
1247                 tn = dev->freeTnodes;
1248 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1249                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != (void *)1) {
1250                         /* Hoosterman, this thing looks like it isn't in the list */
1251                         T(YAFFS_TRACE_ALWAYS,
1252                           (TSTR("yaffs: Tnode list bug 1" TENDSTR)));
1253                 }
1254 #endif
1255                 dev->freeTnodes = dev->freeTnodes->internal[0];
1256                 dev->nFreeTnodes--;
1257         }
1258
1259         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1260
1261         return tn;
1262 }
1263
1264 static yaffs_Tnode *yaffs_GetTnode(yaffs_Device * dev)
1265 {
1266         yaffs_Tnode *tn = yaffs_GetTnodeRaw(dev);
1267         int tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
1268
1269         if(tnodeSize < sizeof(yaffs_Tnode))
1270                 tnodeSize = sizeof(yaffs_Tnode);
1271         
1272         if(tn)
1273                 memset(tn, 0, tnodeSize);
1274
1275         return tn;      
1276 }
1277
1278 /* FreeTnode frees up a tnode and puts it back on the free list */
1279 static void yaffs_FreeTnode(yaffs_Device * dev, yaffs_Tnode * tn)
1280 {
1281         if (tn) {
1282 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1283                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != 0) {
1284                         /* Hoosterman, this thing looks like it is already in the list */
1285                         T(YAFFS_TRACE_ALWAYS,
1286                           (TSTR("yaffs: Tnode list bug 2" TENDSTR)));
1287                 }
1288                 tn->internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1289 #endif
1290                 tn->internal[0] = dev->freeTnodes;
1291                 dev->freeTnodes = tn;
1292                 dev->nFreeTnodes++;
1293         }
1294         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1295         
1296 }
1297
1298 static void yaffs_DeinitialiseTnodes(yaffs_Device * dev)
1299 {
1300         /* Free the list of allocated tnodes */
1301         yaffs_TnodeList *tmp;
1302
1303         while (dev->allocatedTnodeList) {
1304                 tmp = dev->allocatedTnodeList->next;
1305
1306                 YFREE(dev->allocatedTnodeList->tnodes);
1307                 YFREE(dev->allocatedTnodeList);
1308                 dev->allocatedTnodeList = tmp;
1309
1310         }
1311
1312         dev->freeTnodes = NULL;
1313         dev->nFreeTnodes = 0;
1314 }
1315
1316 static void yaffs_InitialiseTnodes(yaffs_Device * dev)
1317 {
1318         dev->allocatedTnodeList = NULL;
1319         dev->freeTnodes = NULL;
1320         dev->nFreeTnodes = 0;
1321         dev->nTnodesCreated = 0;
1322
1323 }
1324
1325
1326 void yaffs_PutLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos, unsigned val)
1327 {
1328   __u32 *map = (__u32 *)tn;
1329   __u32 bitInMap;
1330   __u32 bitInWord;
1331   __u32 wordInMap;
1332   __u32 mask;
1333   
1334   pos &= YAFFS_TNODES_LEVEL0_MASK;
1335   val >>= dev->chunkGroupBits;
1336   
1337   bitInMap = pos * dev->tnodeWidth;
1338   wordInMap = bitInMap /32;
1339   bitInWord = bitInMap & (32 -1);
1340   
1341   mask = dev->tnodeMask << bitInWord;
1342   
1343   map[wordInMap] &= ~mask;
1344   map[wordInMap] |= (mask & (val << bitInWord));
1345   
1346   if(dev->tnodeWidth > (32-bitInWord)) {
1347     bitInWord = (32 - bitInWord);
1348     wordInMap++;;
1349     mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
1350     map[wordInMap] &= ~mask;
1351     map[wordInMap] |= (mask & (val >> bitInWord));
1352   }
1353 }
1354
1355 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos)
1356 {
1357   __u32 *map = (__u32 *)tn;
1358   __u32 bitInMap;
1359   __u32 bitInWord;
1360   __u32 wordInMap;
1361   __u32 val;
1362   
1363   pos &= YAFFS_TNODES_LEVEL0_MASK;
1364   
1365   bitInMap = pos * dev->tnodeWidth;
1366   wordInMap = bitInMap /32;
1367   bitInWord = bitInMap & (32 -1);
1368   
1369   val = map[wordInMap] >> bitInWord;
1370   
1371   if(dev->tnodeWidth > (32-bitInWord)) {
1372     bitInWord = (32 - bitInWord);
1373     wordInMap++;;
1374     val |= (map[wordInMap] << bitInWord);
1375   }
1376   
1377   val &= dev->tnodeMask;
1378   val <<= dev->chunkGroupBits;
1379   
1380   return val;
1381 }
1382
1383 /* ------------------- End of individual tnode manipulation -----------------*/
1384
1385 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
1386  * The look up tree is represented by the top tnode and the number of topLevel
1387  * in the tree. 0 means only the level 0 tnode is in the tree.
1388  */
1389
1390 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
1391 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
1392                                           yaffs_FileStructure * fStruct,
1393                                           __u32 chunkId)
1394 {
1395
1396         yaffs_Tnode *tn = fStruct->top;
1397         __u32 i;
1398         int requiredTallness;
1399         int level = fStruct->topLevel;
1400
1401         /* Check sane level and chunk Id */
1402         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL) {
1403                 return NULL;
1404         }
1405
1406         if (chunkId > YAFFS_MAX_CHUNK_ID) {
1407                 return NULL;
1408         }
1409
1410         /* First check we're tall enough (ie enough topLevel) */
1411
1412         i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1413         requiredTallness = 0;
1414         while (i) {
1415                 i >>= YAFFS_TNODES_INTERNAL_BITS;
1416                 requiredTallness++;
1417         }
1418
1419         if (requiredTallness > fStruct->topLevel) {
1420                 /* Not tall enough, so we can't find it, return NULL. */
1421                 return NULL;
1422         }
1423
1424         /* Traverse down to level 0 */
1425         while (level > 0 && tn) {
1426                 tn = tn->
1427                     internal[(chunkId >>
1428                                ( YAFFS_TNODES_LEVEL0_BITS + 
1429                                  (level - 1) *
1430                                  YAFFS_TNODES_INTERNAL_BITS)
1431                               ) &
1432                              YAFFS_TNODES_INTERNAL_MASK];
1433                 level--;
1434
1435         }
1436
1437         return tn;
1438 }
1439
1440 /* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
1441  * This happens in two steps:
1442  *  1. If the tree isn't tall enough, then make it taller.
1443  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
1444  *
1445  * Used when modifying the tree.
1446  *
1447  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
1448  *  be plugged into the ttree.
1449  */
1450  
1451 static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device * dev,
1452                                                yaffs_FileStructure * fStruct,
1453                                                __u32 chunkId,
1454                                                yaffs_Tnode *passedTn)
1455 {
1456
1457         int requiredTallness;
1458         int i;
1459         int l;
1460         yaffs_Tnode *tn;
1461
1462         __u32 x;
1463
1464
1465         /* Check sane level and page Id */
1466         if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL) {
1467                 return NULL;
1468         }
1469
1470         if (chunkId > YAFFS_MAX_CHUNK_ID) {
1471                 return NULL;
1472         }
1473
1474         /* First check we're tall enough (ie enough topLevel) */
1475
1476         x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1477         requiredTallness = 0;
1478         while (x) {
1479                 x >>= YAFFS_TNODES_INTERNAL_BITS;
1480                 requiredTallness++;
1481         }
1482
1483
1484         if (requiredTallness > fStruct->topLevel) {
1485                 /* Not tall enough,gotta make the tree taller */
1486                 for (i = fStruct->topLevel; i < requiredTallness; i++) {
1487                 
1488                         tn = yaffs_GetTnode(dev);
1489
1490                         if (tn) {
1491                                 tn->internal[0] = fStruct->top;
1492                                 fStruct->top = tn;
1493                         } else {
1494                                 T(YAFFS_TRACE_ERROR,
1495                                   (TSTR("yaffs: no more tnodes" TENDSTR)));
1496                         }
1497                 }
1498
1499                 fStruct->topLevel = requiredTallness;
1500         }
1501
1502         /* Traverse down to level 0, adding anything we need */
1503
1504         l = fStruct->topLevel;
1505         tn = fStruct->top;
1506         
1507         if(l > 0) {
1508                 while (l > 0 && tn) {
1509                         x = (chunkId >>
1510                              ( YAFFS_TNODES_LEVEL0_BITS +
1511                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
1512                             YAFFS_TNODES_INTERNAL_MASK;
1513
1514
1515                         if((l>1) && !tn->internal[x]){
1516                                 /* Add missing non-level-zero tnode */
1517                                 tn->internal[x] = yaffs_GetTnode(dev);
1518
1519                         } else if(l == 1) {
1520                                 /* Looking from level 1 at level 0 */
1521                                 if (passedTn) {
1522                                         /* If we already have one, then release it.*/
1523                                         if(tn->internal[x])
1524                                                 yaffs_FreeTnode(dev,tn->internal[x]);
1525                                         tn->internal[x] = passedTn;
1526                         
1527                                 } else if(!tn->internal[x]) {
1528                                         /* Don't have one, none passed in */
1529                                         tn->internal[x] = yaffs_GetTnode(dev);
1530                                 }
1531                         }
1532                 
1533                         tn = tn->internal[x];
1534                         l--;
1535                 }
1536         } else {
1537                 /* top is level 0 */
1538                 if(passedTn) {
1539                         memcpy(tn,passedTn,(dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
1540                         yaffs_FreeTnode(dev,passedTn);
1541                 }
1542         }
1543
1544         return tn;
1545 }
1546
1547 static int yaffs_FindChunkInGroup(yaffs_Device * dev, int theChunk,
1548                                   yaffs_ExtendedTags * tags, int objectId,
1549                                   int chunkInInode)
1550 {
1551         int j;
1552
1553         for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
1554                 if (yaffs_CheckChunkBit
1555                     (dev, theChunk / dev->nChunksPerBlock,
1556                      theChunk % dev->nChunksPerBlock)) {
1557                         yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
1558                                                         tags);
1559                         if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
1560                                 /* found it; */
1561                                 return theChunk;
1562
1563                         }
1564                 }
1565                 theChunk++;
1566         }
1567         return -1;
1568 }
1569
1570
1571 /* DeleteWorker scans backwards through the tnode tree and deletes all the
1572  * chunks and tnodes in the file
1573  * Returns 1 if the tree was deleted. 
1574  * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
1575  */
1576
1577 static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
1578                               int chunkOffset, int *limit)
1579 {
1580         int i;
1581         int chunkInInode;
1582         int theChunk;
1583         yaffs_ExtendedTags tags;
1584         int foundChunk;
1585         yaffs_Device *dev = in->myDev;
1586
1587         int allDone = 1;
1588
1589         if (tn) {
1590                 if (level > 0) {
1591
1592                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1593                              i--) {
1594                                 if (tn->internal[i]) {
1595                                         if (limit && (*limit) < 0) {
1596                                                 allDone = 0;
1597                                         } else {
1598                                                 allDone =
1599                                                     yaffs_DeleteWorker(in,
1600                                                                        tn->
1601                                                                        internal
1602                                                                        [i],
1603                                                                        level -
1604                                                                        1,
1605                                                                        (chunkOffset
1606                                                                         <<
1607                                                                         YAFFS_TNODES_INTERNAL_BITS)
1608                                                                        + i,
1609                                                                        limit);
1610                                         }
1611                                         if (allDone) {
1612                                                 yaffs_FreeTnode(dev,
1613                                                                 tn->
1614                                                                 internal[i]);
1615                                                 tn->internal[i] = NULL;
1616                                         }
1617                                 }
1618
1619                         }
1620                         return (allDone) ? 1 : 0;
1621                 } else if (level == 0) {
1622                         int hitLimit = 0;
1623
1624                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
1625                              i--) {
1626                                 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
1627                                 if (theChunk) {
1628
1629                                         chunkInInode =
1630                                             (chunkOffset <<
1631                                              YAFFS_TNODES_LEVEL0_BITS) + i;
1632
1633                                         foundChunk =
1634                                             yaffs_FindChunkInGroup(dev,
1635                                                                    theChunk,
1636                                                                    &tags,
1637                                                                    in->objectId,
1638                                                                    chunkInInode);
1639
1640                                         if (foundChunk > 0) {
1641                                                 yaffs_DeleteChunk(dev,
1642                                                                   foundChunk, 1,
1643                                                                   __LINE__);
1644                                                 in->nDataChunks--;
1645                                                 if (limit) {
1646                                                         *limit = *limit - 1;
1647                                                         if (*limit <= 0) {
1648                                                                 hitLimit = 1;
1649                                                         }
1650                                                 }
1651
1652                                         }
1653
1654                                         yaffs_PutLevel0Tnode(dev,tn,i,0);
1655                                 }
1656
1657                         }
1658                         return (i < 0) ? 1 : 0;
1659
1660                 }
1661
1662         }
1663
1664         return 1;
1665
1666 }
1667
1668 static void yaffs_SoftDeleteChunk(yaffs_Device * dev, int chunk)
1669 {
1670
1671         yaffs_BlockInfo *theBlock;
1672
1673         T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
1674
1675         theBlock = yaffs_GetBlockInfo(dev, chunk / dev->nChunksPerBlock);
1676         if (theBlock) {
1677                 theBlock->softDeletions++;
1678                 dev->nFreeChunks++;
1679         }
1680 }
1681
1682 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1683  * All soft deleting does is increment the block's softdelete count and pulls the chunk out
1684  * of the tnode.
1685  * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1686  */
1687  
1688 static int yaffs_SoftDeleteWorker(yaffs_Object * in, yaffs_Tnode * tn,
1689                                   __u32 level, int chunkOffset)
1690 {
1691         int i;
1692         int theChunk;
1693         int allDone = 1;
1694         yaffs_Device *dev = in->myDev;
1695
1696         if (tn) {
1697                 if (level > 0) {
1698
1699                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1700                              i--) {
1701                                 if (tn->internal[i]) {
1702                                         allDone =
1703                                             yaffs_SoftDeleteWorker(in,
1704                                                                    tn->
1705                                                                    internal[i],
1706                                                                    level - 1,
1707                                                                    (chunkOffset
1708                                                                     <<
1709                                                                     YAFFS_TNODES_INTERNAL_BITS)
1710                                                                    + i);
1711                                         if (allDone) {
1712                                                 yaffs_FreeTnode(dev,
1713                                                                 tn->
1714                                                                 internal[i]);
1715                                                 tn->internal[i] = NULL;
1716                                         } else {
1717                                                 /* Hoosterman... how could this happen? */
1718                                         }
1719                                 }
1720                         }
1721                         return (allDone) ? 1 : 0;
1722                 } else if (level == 0) {
1723
1724                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1725                                 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
1726                                 if (theChunk) {
1727                                         /* Note this does not find the real chunk, only the chunk group.
1728                                          * We make an assumption that a chunk group is not larger than 
1729                                          * a block.
1730                                          */
1731                                         yaffs_SoftDeleteChunk(dev, theChunk);
1732                                         yaffs_PutLevel0Tnode(dev,tn,i,0);
1733                                 }
1734
1735                         }
1736                         return 1;
1737
1738                 }
1739
1740         }
1741
1742         return 1;
1743
1744 }
1745
1746 static void yaffs_SoftDeleteFile(yaffs_Object * obj)
1747 {
1748         if (obj->deleted &&
1749             obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
1750                 if (obj->nDataChunks <= 0) {
1751                         /* Empty file with no duplicate object headers, just delete it immediately */
1752                         yaffs_FreeTnode(obj->myDev,
1753                                         obj->variant.fileVariant.top);
1754                         obj->variant.fileVariant.top = NULL;
1755                         T(YAFFS_TRACE_TRACING,
1756                           (TSTR("yaffs: Deleting empty file %d" TENDSTR),
1757                            obj->objectId));
1758                         yaffs_DoGenericObjectDeletion(obj);
1759                 } else {
1760                         yaffs_SoftDeleteWorker(obj,
1761                                                obj->variant.fileVariant.top,
1762                                                obj->variant.fileVariant.
1763                                                topLevel, 0);
1764                         obj->softDeleted = 1;
1765                 }
1766         }
1767 }
1768
1769 /* Pruning removes any part of the file structure tree that is beyond the
1770  * bounds of the file (ie that does not point to chunks).
1771  *
1772  * A file should only get pruned when its size is reduced.
1773  *
1774  * Before pruning, the chunks must be pulled from the tree and the
1775  * level 0 tnode entries must be zeroed out.
1776  * Could also use this for file deletion, but that's probably better handled
1777  * by a special case.
1778  */
1779
1780 static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device * dev, yaffs_Tnode * tn,
1781                                       __u32 level, int del0)
1782 {
1783         int i;
1784         int hasData;
1785
1786         if (tn) {
1787                 hasData = 0;
1788
1789                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1790                         if (tn->internal[i] && level > 0) {
1791                                 tn->internal[i] =
1792                                     yaffs_PruneWorker(dev, tn->internal[i],
1793                                                       level - 1,
1794                                                       (i == 0) ? del0 : 1);
1795                         }
1796
1797                         if (tn->internal[i]) {
1798                                 hasData++;
1799                         }
1800                 }
1801
1802                 if (hasData == 0 && del0) {
1803                         /* Free and return NULL */
1804
1805                         yaffs_FreeTnode(dev, tn);
1806                         tn = NULL;
1807                 }
1808
1809         }
1810
1811         return tn;
1812
1813 }
1814
1815 static int yaffs_PruneFileStructure(yaffs_Device * dev,
1816                                     yaffs_FileStructure * fStruct)
1817 {
1818         int i;
1819         int hasData;
1820         int done = 0;
1821         yaffs_Tnode *tn;
1822
1823         if (fStruct->topLevel > 0) {
1824                 fStruct->top =
1825                     yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);
1826
1827                 /* Now we have a tree with all the non-zero branches NULL but the height
1828                  * is the same as it was.
1829                  * Let's see if we can trim internal tnodes to shorten the tree.
1830                  * We can do this if only the 0th element in the tnode is in use 
1831                  * (ie all the non-zero are NULL)
1832                  */
1833
1834                 while (fStruct->topLevel && !done) {
1835                         tn = fStruct->top;
1836
1837                         hasData = 0;
1838                         for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1839                                 if (tn->internal[i]) {
1840                                         hasData++;
1841                                 }
1842                         }
1843
1844                         if (!hasData) {
1845                                 fStruct->top = tn->internal[0];
1846                                 fStruct->topLevel--;
1847                                 yaffs_FreeTnode(dev, tn);
1848                         } else {
1849                                 done = 1;
1850                         }
1851                 }
1852         }
1853
1854         return YAFFS_OK;
1855 }
1856
1857 /*-------------------- End of File Structure functions.-------------------*/
1858
1859 /* yaffs_CreateFreeObjects creates a bunch more objects and
1860  * adds them to the object free list.
1861  */
1862 static int yaffs_CreateFreeObjects(yaffs_Device * dev, int nObjects)
1863 {
1864         int i;
1865         yaffs_Object *newObjects;
1866         yaffs_ObjectList *list;
1867
1868         if (nObjects < 1)
1869                 return YAFFS_OK;
1870
1871         /* make these things */
1872         newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
1873         list = YMALLOC(sizeof(yaffs_ObjectList));
1874
1875         if (!newObjects || !list) {
1876                 if(newObjects)
1877                         YFREE(newObjects);
1878                 if(list)
1879                         YFREE(list);
1880                 T(YAFFS_TRACE_ALLOCATE,
1881                   (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
1882                 return YAFFS_FAIL;
1883         }
1884         
1885         /* Hook them into the free list */
1886         for (i = 0; i < nObjects - 1; i++) {
1887                 newObjects[i].siblings.next =
1888                     (struct ylist_head *)(&newObjects[i + 1]);
1889         }
1890
1891         newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
1892         dev->freeObjects = newObjects;
1893         dev->nFreeObjects += nObjects;
1894         dev->nObjectsCreated += nObjects;
1895
1896         /* Now add this bunch of Objects to a list for freeing up. */
1897
1898         list->objects = newObjects;
1899         list->next = dev->allocatedObjectList;
1900         dev->allocatedObjectList = list;
1901
1902         return YAFFS_OK;
1903 }
1904
1905
1906 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
1907 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device * dev)
1908 {
1909         yaffs_Object *tn = NULL;
1910
1911 #ifdef VALGRIND_TEST
1912         tn = YMALLOC(sizeof(yaffs_Object));
1913 #else
1914         /* If there are none left make more */
1915         if (!dev->freeObjects) {
1916                 yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
1917         }
1918
1919         if (dev->freeObjects) {
1920                 tn = dev->freeObjects;
1921                 dev->freeObjects =
1922                     (yaffs_Object *) (dev->freeObjects->siblings.next);
1923                 dev->nFreeObjects--;
1924         }
1925 #endif
1926         if(tn){
1927                 /* Now sweeten it up... */
1928
1929                 memset(tn, 0, sizeof(yaffs_Object));
1930                 tn->myDev = dev;
1931                 tn->hdrChunk = 0;
1932                 tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
1933                 YINIT_LIST_HEAD(&(tn->hardLinks));
1934                 YINIT_LIST_HEAD(&(tn->hashLink));
1935                 YINIT_LIST_HEAD(&tn->siblings);
1936                 
1937
1938                 /* Now make the directory sane */
1939                 if(dev->rootDir){
1940                         tn->parent = dev->rootDir;
1941                         ylist_add(&(tn->siblings),&dev->rootDir->variant.directoryVariant.children);
1942                 }
1943
1944                 /* Add it to the lost and found directory.
1945                  * NB Can't put root or lostNFound in lostNFound so
1946                  * check if lostNFound exists first
1947                  */
1948                 if (dev->lostNFoundDir) {
1949                         yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
1950                 }
1951         }
1952         
1953         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1954
1955         return tn;
1956 }
1957
1958 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device * dev, int number,
1959                                                __u32 mode)
1960 {
1961
1962         yaffs_Object *obj =
1963             yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1964         if (obj) {
1965                 obj->fake = 1;          /* it is fake so it might have no NAND presence... */
1966                 obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
1967                 obj->unlinkAllowed = 0; /* ... or unlink it */
1968                 obj->deleted = 0;
1969                 obj->unlinked = 0;
1970                 obj->yst_mode = mode;
1971                 obj->myDev = dev;
1972                 obj->hdrChunk = 0;      /* Not a valid chunk. */
1973         }
1974
1975         return obj;
1976
1977 }
1978
1979 static void yaffs_UnhashObject(yaffs_Object * tn)
1980 {
1981         int bucket;
1982         yaffs_Device *dev = tn->myDev;
1983
1984         /* If it is still linked into the bucket list, free from the list */
1985         if (!ylist_empty(&tn->hashLink)) {
1986                 ylist_del_init(&tn->hashLink);
1987                 bucket = yaffs_HashFunction(tn->objectId);
1988                 dev->objectBucket[bucket].count--;
1989         }
1990
1991 }
1992
1993 /*  FreeObject frees up a Object and puts it back on the free list */
1994 static void yaffs_FreeObject(yaffs_Object * tn)
1995 {
1996
1997         yaffs_Device *dev = tn->myDev;
1998
1999         
2000         if(tn->parent)
2001                 YBUG();
2002         if(!ylist_empty(&tn->siblings))
2003                 YBUG();
2004
2005
2006 #ifdef  __KERNEL__
2007         if (tn->myInode) {
2008                 /* We're still hooked up to a cached inode.
2009                  * Don't delete now, but mark for later deletion
2010                  */
2011                 tn->deferedFree = 1;
2012                 return;
2013         }
2014 #endif
2015
2016         yaffs_UnhashObject(tn);
2017
2018 #ifdef VALGRIND_TEST
2019         YFREE(tn);
2020 #else
2021         /* Link into the free list. */
2022         tn->siblings.next = (struct ylist_head *)(dev->freeObjects);
2023         dev->freeObjects = tn;
2024         dev->nFreeObjects++;
2025 #endif
2026         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
2027
2028 }
2029
2030 #ifdef __KERNEL__
2031
2032 void yaffs_HandleDeferedFree(yaffs_Object * obj)
2033 {
2034         if (obj->deferedFree) {
2035                 yaffs_FreeObject(obj);
2036         }
2037 }
2038
2039 #endif
2040
2041 static void yaffs_DeinitialiseObjects(yaffs_Device * dev)
2042 {
2043         /* Free the list of allocated Objects */
2044
2045         yaffs_ObjectList *tmp;
2046
2047         while (dev->allocatedObjectList) {
2048                 tmp = dev->allocatedObjectList->next;
2049                 YFREE(dev->allocatedObjectList->objects);
2050                 YFREE(dev->allocatedObjectList);
2051
2052                 dev->allocatedObjectList = tmp;
2053         }
2054
2055         dev->freeObjects = NULL;
2056         dev->nFreeObjects = 0;
2057 }
2058
2059 static void yaffs_InitialiseObjects(yaffs_Device * dev)
2060 {
2061         int i;
2062
2063         dev->allocatedObjectList = NULL;
2064         dev->freeObjects = NULL;
2065         dev->nFreeObjects = 0;
2066
2067         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2068                 YINIT_LIST_HEAD(&dev->objectBucket[i].list);
2069                 dev->objectBucket[i].count = 0;
2070         }
2071
2072 }
2073
2074 static int yaffs_FindNiceObjectBucket(yaffs_Device * dev)
2075 {
2076         static int x = 0;
2077         int i;
2078         int l = 999;
2079         int lowest = 999999;
2080
2081         /* First let's see if we can find one that's empty. */
2082
2083         for (i = 0; i < 10 && lowest > 0; i++) {
2084                 x++;
2085                 x %= YAFFS_NOBJECT_BUCKETS;
2086                 if (dev->objectBucket[x].count < lowest) {
2087                         lowest = dev->objectBucket[x].count;
2088                         l = x;
2089                 }
2090
2091         }
2092
2093         /* If we didn't find an empty list, then try
2094          * looking a bit further for a short one
2095          */
2096
2097         for (i = 0; i < 10 && lowest > 3; i++) {
2098                 x++;
2099                 x %= YAFFS_NOBJECT_BUCKETS;
2100                 if (dev->objectBucket[x].count < lowest) {
2101                         lowest = dev->objectBucket[x].count;
2102                         l = x;
2103                 }
2104
2105         }
2106
2107         return l;
2108 }
2109
2110 static int yaffs_CreateNewObjectNumber(yaffs_Device * dev)
2111 {
2112         int bucket = yaffs_FindNiceObjectBucket(dev);
2113
2114         /* Now find an object value that has not already been taken
2115          * by scanning the list.
2116          */
2117
2118         int found = 0;
2119         struct ylist_head *i;
2120
2121         __u32 n = (__u32) bucket;
2122
2123         /* yaffs_CheckObjectHashSanity();  */
2124
2125         while (!found) {
2126                 found = 1;
2127                 n += YAFFS_NOBJECT_BUCKETS;
2128                 if (1 || dev->objectBucket[bucket].count > 0) {
2129                         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2130                                 /* If there is already one in the list */
2131                                 if (i
2132                                     && ylist_entry(i, yaffs_Object,
2133                                                   hashLink)->objectId == n) {
2134                                         found = 0;
2135                                 }
2136                         }
2137                 }
2138         }
2139
2140
2141         return n;
2142 }
2143
2144 static void yaffs_HashObject(yaffs_Object * in)
2145 {
2146         int bucket = yaffs_HashFunction(in->objectId);
2147         yaffs_Device *dev = in->myDev;
2148
2149         ylist_add(&in->hashLink, &dev->objectBucket[bucket].list);
2150         dev->objectBucket[bucket].count++;
2151
2152 }
2153
2154 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device * dev, __u32 number)
2155 {
2156         int bucket = yaffs_HashFunction(number);
2157         struct ylist_head *i;
2158         yaffs_Object *in;
2159
2160         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2161                 /* Look if it is in the list */
2162                 if (i) {
2163                         in = ylist_entry(i, yaffs_Object, hashLink);
2164                         if (in->objectId == number) {
2165 #ifdef __KERNEL__
2166                                 /* Don't tell the VFS about this one if it is defered free */
2167                                 if (in->deferedFree)
2168                                         return NULL;
2169 #endif
2170
2171                                 return in;
2172                         }
2173                 }
2174         }
2175
2176         return NULL;
2177 }
2178
2179 yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
2180                                     yaffs_ObjectType type)
2181 {
2182
2183         yaffs_Object *theObject;
2184         yaffs_Tnode *tn = NULL;
2185
2186         if (number < 0) {
2187                 number = yaffs_CreateNewObjectNumber(dev);
2188         }
2189
2190         theObject = yaffs_AllocateEmptyObject(dev);
2191         if(!theObject)
2192                 return NULL;
2193                 
2194         if(type == YAFFS_OBJECT_TYPE_FILE){
2195                 tn = yaffs_GetTnode(dev);
2196                 if(!tn){
2197                         yaffs_FreeObject(theObject);
2198                         return NULL;
2199                 }
2200         }
2201                 
2202         
2203
2204         if (theObject) {
2205                 theObject->fake = 0;
2206                 theObject->renameAllowed = 1;
2207                 theObject->unlinkAllowed = 1;
2208                 theObject->objectId = number;
2209                 yaffs_HashObject(theObject);
2210                 theObject->variantType = type;
2211 #ifdef CONFIG_YAFFS_WINCE
2212                 yfsd_WinFileTimeNow(theObject->win_atime);
2213                 theObject->win_ctime[0] = theObject->win_mtime[0] =
2214                     theObject->win_atime[0];
2215                 theObject->win_ctime[1] = theObject->win_mtime[1] =
2216                     theObject->win_atime[1];
2217
2218 #else
2219
2220                 theObject->yst_atime = theObject->yst_mtime =
2221                     theObject->yst_ctime = Y_CURRENT_TIME;
2222 #endif
2223
2224 #if 0
2225                 theObject->sum_prev = 12345;
2226                 theObject->sum_trailer = 6789;
2227 #endif
2228
2229                 switch (type) {
2230                 case YAFFS_OBJECT_TYPE_FILE:
2231                         theObject->variant.fileVariant.fileSize = 0;
2232                         theObject->variant.fileVariant.scannedFileSize = 0;
2233                         theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
2234                         theObject->variant.fileVariant.topLevel = 0;
2235                         theObject->variant.fileVariant.top = tn;
2236                         break;
2237                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2238                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
2239                                        children);
2240                         break;
2241                 case YAFFS_OBJECT_TYPE_SYMLINK:
2242                 case YAFFS_OBJECT_TYPE_HARDLINK:
2243                 case YAFFS_OBJECT_TYPE_SPECIAL:
2244                         /* No action required */
2245                         break;
2246                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2247                         /* todo this should not happen */
2248                         break;
2249                 }
2250         }
2251
2252         return theObject;
2253 }
2254
2255 static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device * dev,
2256                                                       int number,
2257                                                       yaffs_ObjectType type)
2258 {
2259         yaffs_Object *theObject = NULL;
2260
2261         if (number > 0) {
2262                 theObject = yaffs_FindObjectByNumber(dev, number);
2263         }
2264
2265         if (!theObject) {
2266                 theObject = yaffs_CreateNewObject(dev, number, type);
2267         }
2268
2269         return theObject;
2270
2271 }
2272                         
2273
2274 static YCHAR *yaffs_CloneString(const YCHAR * str)
2275 {
2276         YCHAR *newStr = NULL;
2277
2278         if (str && *str) {
2279                 newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
2280                 if(newStr)
2281                         yaffs_strcpy(newStr, str);
2282         }
2283
2284         return newStr;
2285
2286 }
2287
2288 /*
2289  * Mknod (create) a new object.
2290  * equivalentObject only has meaning for a hard link;
2291  * aliasString only has meaning for a sumlink.
2292  * rdev only has meaning for devices (a subset of special objects)
2293  */
2294  
2295 static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
2296                                        yaffs_Object * parent,
2297                                        const YCHAR * name,
2298                                        __u32 mode,
2299                                        __u32 uid,
2300                                        __u32 gid,
2301                                        yaffs_Object * equivalentObject,
2302                                        const YCHAR * aliasString, __u32 rdev)
2303 {
2304         yaffs_Object *in;
2305         YCHAR *str = NULL;
2306
2307         yaffs_Device *dev = parent->myDev;
2308
2309         /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
2310         if (yaffs_FindObjectByName(parent, name)) {
2311                 return NULL;
2312         }
2313
2314         in = yaffs_CreateNewObject(dev, -1, type);
2315
2316         if(!in)
2317                 return YAFFS_FAIL;
2318         
2319         if(type == YAFFS_OBJECT_TYPE_SYMLINK){
2320                 str = yaffs_CloneString(aliasString);
2321                 if(!str){
2322                         yaffs_FreeObject(in);
2323                         return NULL;
2324                 }
2325         }
2326         
2327         
2328
2329         if (in) {
2330                 in->hdrChunk = 0;
2331                 in->valid = 1;
2332                 in->variantType = type;
2333
2334                 in->yst_mode = mode;
2335
2336 #ifdef CONFIG_YAFFS_WINCE
2337                 yfsd_WinFileTimeNow(in->win_atime);
2338                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
2339                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
2340
2341 #else
2342                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
2343
2344                 in->yst_rdev = rdev;
2345                 in->yst_uid = uid;
2346                 in->yst_gid = gid;
2347 #endif
2348                 in->nDataChunks = 0;
2349
2350                 yaffs_SetObjectName(in, name);
2351                 in->dirty = 1;
2352
2353                 yaffs_AddObjectToDirectory(parent, in);
2354
2355                 in->myDev = parent->myDev;
2356
2357                 switch (type) {
2358                 case YAFFS_OBJECT_TYPE_SYMLINK:
2359                         in->variant.symLinkVariant.alias = str;
2360                         break;
2361                 case YAFFS_OBJECT_TYPE_HARDLINK:
2362                         in->variant.hardLinkVariant.equivalentObject =
2363                             equivalentObject;
2364                         in->variant.hardLinkVariant.equivalentObjectId =
2365                             equivalentObject->objectId;
2366                         ylist_add(&in->hardLinks, &equivalentObject->hardLinks);
2367                         break;
2368                 case YAFFS_OBJECT_TYPE_FILE:    
2369                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2370                 case YAFFS_OBJECT_TYPE_SPECIAL:
2371                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2372                         /* do nothing */
2373                         break;
2374                 }
2375
2376                 if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
2377                         /* Could not create the object header, fail the creation */
2378                         yaffs_DestroyObject(in);
2379                         in = NULL;
2380                 }
2381
2382         }
2383
2384         return in;
2385 }
2386
2387 yaffs_Object *yaffs_MknodFile(yaffs_Object * parent, const YCHAR * name,
2388                               __u32 mode, __u32 uid, __u32 gid)
2389 {
2390         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2391                                  uid, gid, NULL, NULL, 0);
2392 }
2393
2394 yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
2395                                    __u32 mode, __u32 uid, __u32 gid)
2396 {
2397         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2398                                  mode, uid, gid, NULL, NULL, 0);
2399 }
2400
2401 yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
2402                                  __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
2403 {
2404         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2405                                  uid, gid, NULL, NULL, rdev);
2406 }
2407
2408 yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
2409                                  __u32 mode, __u32 uid, __u32 gid,
2410                                  const YCHAR * alias)
2411 {
2412         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2413                                  uid, gid, NULL, alias, 0);
2414 }
2415
2416 /* yaffs_Link returns the object id of the equivalent object.*/
2417 yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
2418                          yaffs_Object * equivalentObject)
2419 {
2420         /* Get the real object in case we were fed a hard link as an equivalent object */
2421         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
2422
2423         if (yaffs_MknodObject
2424             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
2425              equivalentObject, NULL, 0)) {
2426                 return equivalentObject;
2427         } else {
2428                 return NULL;
2429         }
2430
2431 }
2432
2433 static int yaffs_ChangeObjectName(yaffs_Object * obj, yaffs_Object * newDir,
2434                                   const YCHAR * newName, int force, int shadows)
2435 {
2436         int unlinkOp;
2437         int deleteOp;
2438
2439         yaffs_Object *existingTarget;
2440
2441         if (newDir == NULL) {
2442                 newDir = obj->parent;   /* use the old directory */
2443         }
2444
2445         if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
2446                 T(YAFFS_TRACE_ALWAYS,
2447                   (TSTR
2448                    ("tragedy: yaffs_ChangeObjectName: newDir is not a directory"
2449                     TENDSTR)));
2450                 YBUG();
2451         }
2452         
2453         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
2454         if (obj->myDev->isYaffs2) {
2455                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
2456         } else {
2457                 unlinkOp = (newDir == obj->myDev->unlinkedDir
2458                             && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
2459         }
2460
2461         deleteOp = (newDir == obj->myDev->deletedDir);
2462
2463         existingTarget = yaffs_FindObjectByName(newDir, newName);
2464
2465         /* If the object is a file going into the unlinked directory, 
2466          *   then it is OK to just stuff it in since duplicate names are allowed.
2467          *   else only proceed if the new name does not exist and if we're putting 
2468          *   it into a directory.
2469          */
2470         if ((unlinkOp ||
2471              deleteOp ||
2472              force ||
2473              (shadows > 0) ||
2474              !existingTarget) &&
2475             newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
2476                 yaffs_SetObjectName(obj, newName);
2477                 obj->dirty = 1;
2478
2479                 yaffs_AddObjectToDirectory(newDir, obj);
2480
2481                 if (unlinkOp)
2482                         obj->unlinked = 1;
2483
2484                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
2485                 if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows)>= 0)
2486                         return YAFFS_OK;
2487         }
2488
2489         return YAFFS_FAIL;
2490 }
2491
2492 int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
2493                        yaffs_Object * newDir, const YCHAR * newName)
2494 {
2495         yaffs_Object *obj=NULL;
2496         yaffs_Object *existingTarget=NULL;
2497         int force = 0;
2498         
2499         
2500         if(!oldDir || oldDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2501                 YBUG();
2502         if(!newDir || newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2503                 YBUG();
2504
2505 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
2506         /* Special case for case insemsitive systems (eg. WinCE).
2507          * While look-up is case insensitive, the name isn't.
2508          * Therefore we might want to change x.txt to X.txt
2509         */
2510         if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0) {
2511                 force = 1;
2512         }
2513 #endif
2514
2515         else if (yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
2516           /* ENAMETOOLONG */
2517           return YAFFS_FAIL;
2518
2519         obj = yaffs_FindObjectByName(oldDir, oldName);
2520
2521         if (obj && obj->renameAllowed) {
2522
2523                 /* Now do the handling for an existing target, if there is one */
2524
2525                 existingTarget = yaffs_FindObjectByName(newDir, newName);
2526                 if (existingTarget &&
2527                     existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
2528                     !ylist_empty(&existingTarget->variant.directoryVariant.children)) {
2529                         /* There is a target that is a non-empty directory, so we fail */
2530                         return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
2531                 } else if (existingTarget && existingTarget != obj) {
2532                         /* Nuke the target first, using shadowing, 
2533                          * but only if it isn't the same object
2534                          */
2535                         yaffs_ChangeObjectName(obj, newDir, newName, force,
2536                                                existingTarget->objectId);
2537                         yaffs_UnlinkObject(existingTarget);
2538                 }
2539
2540                 return yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
2541         }
2542         return YAFFS_FAIL;
2543 }
2544
2545 /*------------------------- Block Management and Page Allocation ----------------*/
2546
2547 static int yaffs_InitialiseBlocks(yaffs_Device * dev)
2548 {
2549         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
2550         
2551         dev->blockInfo = NULL;
2552         dev->chunkBits = NULL;
2553         
2554         dev->allocationBlock = -1;      /* force it to get a new one */
2555
2556         /* If the first allocation strategy fails, thry the alternate one */
2557         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
2558         if(!dev->blockInfo){
2559                 dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
2560                 dev->blockInfoAlt = 1;
2561         }
2562         else
2563                 dev->blockInfoAlt = 0;
2564                 
2565         if(dev->blockInfo){
2566         
2567                 /* Set up dynamic blockinfo stuff. */
2568                 dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; /* round up bytes */
2569                 dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
2570                 if(!dev->chunkBits){
2571                         dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
2572                         dev->chunkBitsAlt = 1;
2573                 }
2574                 else
2575                         dev->chunkBitsAlt = 0;
2576         }
2577         
2578         if (dev->blockInfo && dev->chunkBits) {
2579                 memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
2580                 memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
2581                 return YAFFS_OK;
2582         }
2583
2584         return YAFFS_FAIL;
2585
2586 }
2587
2588 static void yaffs_DeinitialiseBlocks(yaffs_Device * dev)
2589 {
2590         if(dev->blockInfoAlt && dev->blockInfo)
2591                 YFREE_ALT(dev->blockInfo);
2592         else if(dev->blockInfo)
2593                 YFREE(dev->blockInfo);
2594
2595         dev->blockInfoAlt = 0;
2596
2597         dev->blockInfo = NULL;
2598         
2599         if(dev->chunkBitsAlt && dev->chunkBits)
2600                 YFREE_ALT(dev->chunkBits);
2601         else if(dev->chunkBits)
2602                 YFREE(dev->chunkBits);
2603         dev->chunkBitsAlt = 0;
2604         dev->chunkBits = NULL;
2605 }
2606
2607 static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device * dev,
2608                                             yaffs_BlockInfo * bi)
2609 {
2610         int i;
2611         __u32 seq;
2612         yaffs_BlockInfo *b;
2613
2614         if (!dev->isYaffs2)
2615                 return 1;       /* disqualification only applies to yaffs2. */
2616
2617         if (!bi->hasShrinkHeader)
2618                 return 1;       /* can gc */
2619
2620         /* Find the oldest dirty sequence number if we don't know it and save it
2621          * so we don't have to keep recomputing it.
2622          */
2623         if (!dev->oldestDirtySequence) {
2624                 seq = dev->sequenceNumber;
2625
2626                 for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
2627                      i++) {
2628                         b = yaffs_GetBlockInfo(dev, i);
2629                         if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
2630                             (b->pagesInUse - b->softDeletions) <
2631                             dev->nChunksPerBlock && b->sequenceNumber < seq) {
2632                                 seq = b->sequenceNumber;
2633                         }
2634                 }
2635                 dev->oldestDirtySequence = seq;
2636         }
2637
2638         /* Can't do gc of this block if there are any blocks older than this one that have
2639          * discarded pages.
2640          */
2641         return (bi->sequenceNumber <= dev->oldestDirtySequence);
2642
2643 }
2644
2645 /* FindDiretiestBlock is used to select the dirtiest block (or close enough)
2646  * for garbage collection.
2647  */
2648
2649 static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
2650                                                int aggressive)
2651 {
2652
2653         int b = dev->currentDirtyChecker;
2654
2655         int i;
2656         int iterations;
2657         int dirtiest = -1;
2658         int pagesInUse = 0;
2659         int prioritised=0;
2660         yaffs_BlockInfo *bi;
2661         int pendingPrioritisedExist = 0;
2662         
2663         /* First let's see if we need to grab a prioritised block */
2664         if(dev->hasPendingPrioritisedGCs){
2665                 for(i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++){
2666
2667                         bi = yaffs_GetBlockInfo(dev, i);
2668                         //yaffs_VerifyBlock(dev,bi,i);
2669                         
2670                         if(bi->gcPrioritise) {
2671                                 pendingPrioritisedExist = 1;
2672                                 if(bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2673                                    yaffs_BlockNotDisqualifiedFromGC(dev, bi)){
2674                                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2675                                         dirtiest = i;
2676                                         prioritised = 1;
2677                                         aggressive = 1; /* Fool the non-aggressive skip logiv below */
2678                                 }
2679                         }
2680                 }
2681                 
2682                 if(!pendingPrioritisedExist) /* None found, so we can clear this */
2683                         dev->hasPendingPrioritisedGCs = 0;
2684         }
2685
2686         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2687          * search harder.
2688          * else (we're doing a leasurely gc), then we only bother to do this if the
2689          * block has only a few pages in use.
2690          */
2691
2692         dev->nonAggressiveSkip--;
2693
2694         if (!aggressive && (dev->nonAggressiveSkip > 0)) {
2695                 return -1;
2696         }
2697
2698         if(!prioritised)
2699                 pagesInUse =
2700                         (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
2701
2702         if (aggressive) {
2703                 iterations =
2704                     dev->internalEndBlock - dev->internalStartBlock + 1;
2705         } else {
2706                 iterations =
2707                     dev->internalEndBlock - dev->internalStartBlock + 1;
2708                 iterations = iterations / 16;
2709                 if (iterations > 200) {
2710                         iterations = 200;
2711                 }
2712         }
2713
2714         for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
2715                 b++;
2716                 if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
2717                         b = dev->internalStartBlock;
2718                 }
2719
2720                 if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
2721                         T(YAFFS_TRACE_ERROR,
2722                           (TSTR("**>> Block %d is not valid" TENDSTR), b));
2723                         YBUG();
2724                 }
2725
2726                 bi = yaffs_GetBlockInfo(dev, b);
2727
2728 #if 0
2729                 if (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT) {
2730                         dirtiest = b;
2731                         pagesInUse = 0;
2732                 }
2733                 else 
2734 #endif
2735
2736                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2737                        (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
2738                         yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2739                         dirtiest = b;
2740                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2741                 }
2742         }
2743
2744         dev->currentDirtyChecker = b;
2745
2746         if (dirtiest > 0) {
2747                 T(YAFFS_TRACE_GC,
2748                   (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
2749                    dev->nChunksPerBlock - pagesInUse,prioritised));
2750         }
2751
2752         dev->oldestDirtySequence = 0;
2753
2754         if (dirtiest > 0) {
2755                 dev->nonAggressiveSkip = 4;
2756         }
2757
2758         return dirtiest;
2759 }
2760
2761 static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
2762 {
2763         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
2764
2765         int erasedOk = 0;
2766
2767         /* If the block is still healthy erase it and mark as clean.
2768          * If the block has had a data failure, then retire it.
2769          */
2770          
2771         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2772                 (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
2773                 blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
2774                 
2775         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
2776
2777         if (!bi->needsRetiring) {
2778                 yaffs_InvalidateCheckpoint(dev);
2779                 erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
2780                 if (!erasedOk) {
2781                         dev->nErasureFailures++;
2782                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2783                           (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
2784                 }
2785         }
2786
2787         if (erasedOk && 
2788             ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
2789                 int i;
2790                 for (i = 0; i < dev->nChunksPerBlock; i++) {
2791                         if (!yaffs_CheckChunkErased
2792                             (dev, blockNo * dev->nChunksPerBlock + i)) {
2793                                 T(YAFFS_TRACE_ERROR,
2794                                   (TSTR
2795                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
2796                                     TENDSTR), blockNo, i));
2797                         }
2798                 }
2799         }
2800
2801         if (erasedOk) {
2802                 /* Clean it up... */
2803                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
2804                 dev->nErasedBlocks++;
2805                 bi->pagesInUse = 0;
2806                 bi->softDeletions = 0;
2807                 bi->hasShrinkHeader = 0;
2808                 bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
2809                 bi->gcPrioritise = 0;
2810                 yaffs_ClearChunkBits(dev, blockNo);
2811
2812                 T(YAFFS_TRACE_ERASE,
2813                   (TSTR("Erased block %d" TENDSTR), blockNo));
2814         } else {
2815                 dev->nFreeChunks -= dev->nChunksPerBlock;       /* We lost a block of free space */
2816
2817                 yaffs_RetireBlock(dev, blockNo);
2818                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2819                   (TSTR("**>> Block %d retired" TENDSTR), blockNo));
2820         }
2821 }
2822
2823 static int yaffs_FindBlockForAllocation(yaffs_Device * dev)
2824 {
2825         int i;
2826
2827         yaffs_BlockInfo *bi;
2828
2829         if (dev->nErasedBlocks < 1) {
2830                 /* Hoosterman we've got a problem.
2831                  * Can't get space to gc
2832                  */
2833                 T(YAFFS_TRACE_ERROR,
2834                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
2835
2836                 return -1;
2837         }
2838         
2839         /* Find an empty block. */
2840
2841         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
2842                 dev->allocationBlockFinder++;
2843                 if (dev->allocationBlockFinder < dev->internalStartBlock
2844                     || dev->allocationBlockFinder > dev->internalEndBlock) {
2845                         dev->allocationBlockFinder = dev->internalStartBlock;
2846                 }
2847
2848                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
2849
2850                 if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
2851                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
2852                         dev->sequenceNumber++;
2853                         bi->sequenceNumber = dev->sequenceNumber;
2854                         dev->nErasedBlocks--;
2855                         T(YAFFS_TRACE_ALLOCATE,
2856                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
2857                            dev->allocationBlockFinder, dev->sequenceNumber,
2858                            dev->nErasedBlocks));
2859                         return dev->allocationBlockFinder;
2860                 }
2861         }
2862
2863         T(YAFFS_TRACE_ALWAYS,
2864           (TSTR
2865            ("yaffs tragedy: no more erased blocks, but there should have been %d"
2866             TENDSTR), dev->nErasedBlocks));
2867
2868         return -1;
2869 }
2870
2871
2872
2873 static int yaffs_CalcCheckpointBlocksRequired(yaffs_Device *dev)
2874 {
2875         if(!dev->nCheckpointBlocksRequired &&
2876            dev->isYaffs2){
2877                 /* Not a valid value so recalculate */
2878                 int nBytes = 0;
2879                 int nBlocks;
2880                 int devBlocks = (dev->endBlock - dev->startBlock + 1);
2881                 int tnodeSize;
2882
2883                 tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
2884
2885                 if(tnodeSize < sizeof(yaffs_Tnode))
2886                         tnodeSize = sizeof(yaffs_Tnode);
2887                 
2888                 nBytes += sizeof(yaffs_CheckpointValidity);
2889                 nBytes += sizeof(yaffs_CheckpointDevice);
2890                 nBytes += devBlocks * sizeof(yaffs_BlockInfo);
2891                 nBytes += devBlocks * dev->chunkBitmapStride;
2892                 nBytes += (sizeof(yaffs_CheckpointObject) + sizeof(__u32)) * (dev->nObjectsCreated - dev->nFreeObjects);
2893                 nBytes += (tnodeSize + sizeof(__u32)) * (dev->nTnodesCreated - dev->nFreeTnodes);
2894                 nBytes += sizeof(yaffs_CheckpointValidity);
2895                 nBytes += sizeof(__u32); /* checksum*/
2896         
2897                 /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
2898         
2899                 nBlocks = (nBytes/(dev->nDataBytesPerChunk * dev->nChunksPerBlock)) + 3;
2900         
2901                 dev->nCheckpointBlocksRequired = nBlocks;
2902         }
2903
2904         return dev->nCheckpointBlocksRequired;
2905 }
2906
2907 // Check if there's space to allocate...
2908 // Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
2909 static int yaffs_CheckSpaceForAllocation(yaffs_Device * dev)
2910 {
2911         int reservedChunks;
2912         int reservedBlocks = dev->nReservedBlocks;
2913         int checkpointBlocks;
2914         
2915         if(dev->isYaffs2){
2916                 checkpointBlocks =  yaffs_CalcCheckpointBlocksRequired(dev) - 
2917                                     dev->blocksInCheckpoint;
2918                 if(checkpointBlocks < 0)
2919                         checkpointBlocks = 0;
2920         } else {
2921                 checkpointBlocks =0;
2922         }
2923         
2924         reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);
2925         
2926         return (dev->nFreeChunks > reservedChunks);
2927 }
2928
2929 static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr)
2930 {
2931         int retVal;
2932         yaffs_BlockInfo *bi;
2933
2934         if (dev->allocationBlock < 0) {
2935                 /* Get next block to allocate off */
2936                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
2937                 dev->allocationPage = 0;
2938         }
2939
2940         if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
2941                 /* Not enough space to allocate unless we're allowed to use the reserve. */
2942                 return -1;
2943         }
2944
2945         if (dev->nErasedBlocks < dev->nReservedBlocks
2946             && dev->allocationPage == 0) {
2947                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
2948         }
2949
2950         /* Next page please.... */
2951         if (dev->allocationBlock >= 0) {
2952                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
2953
2954                 retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
2955                     dev->allocationPage;
2956                 bi->pagesInUse++;
2957                 yaffs_SetChunkBit(dev, dev->allocationBlock,
2958                                   dev->allocationPage);
2959
2960                 dev->allocationPage++;
2961
2962                 dev->nFreeChunks--;
2963
2964                 /* If the block is full set the state to full */
2965                 if (dev->allocationPage >= dev->nChunksPerBlock) {
2966                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2967                         dev->allocationBlock = -1;
2968                 }
2969
2970                 if(blockUsedPtr)
2971                         *blockUsedPtr = bi;
2972                         
2973                 return retVal;
2974         }
2975         
2976         T(YAFFS_TRACE_ERROR,
2977           (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
2978
2979         return -1;
2980 }
2981
2982 static int yaffs_GetErasedChunks(yaffs_Device * dev)
2983 {
2984         int n;
2985
2986         n = dev->nErasedBlocks * dev->nChunksPerBlock;
2987
2988         if (dev->allocationBlock > 0) {
2989                 n += (dev->nChunksPerBlock - dev->allocationPage);
2990         }
2991
2992         return n;
2993
2994 }
2995
2996 static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
2997 {
2998         int oldChunk;
2999         int newChunk;
3000         int chunkInBlock;
3001         int markNAND;
3002         int retVal = YAFFS_OK;
3003         int cleanups = 0;
3004         int i;
3005         int isCheckpointBlock;
3006         int matchingChunk;
3007
3008         int chunksBefore = yaffs_GetErasedChunks(dev);
3009         int chunksAfter;
3010
3011         yaffs_ExtendedTags tags;
3012
3013         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
3014
3015         yaffs_Object *object;
3016
3017         isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
3018         
3019         bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
3020
3021         T(YAFFS_TRACE_TRACING,
3022           (TSTR("Collecting block %d, in use %d, shrink %d, " TENDSTR), block,
3023            bi->pagesInUse, bi->hasShrinkHeader));
3024
3025         /*yaffs_VerifyFreeChunks(dev); */
3026
3027         bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
3028
3029         /* Take off the number of soft deleted entries because
3030          * they're going to get really deleted during GC.
3031          */
3032         dev->nFreeChunks -= bi->softDeletions;
3033
3034         dev->isDoingGC = 1;
3035
3036         if (isCheckpointBlock ||
3037             !yaffs_StillSomeChunkBits(dev, block)) {
3038                 T(YAFFS_TRACE_TRACING,
3039                   (TSTR
3040                    ("Collecting block %d that has no chunks in use" TENDSTR),
3041                    block));
3042                 yaffs_BlockBecameDirty(dev, block);
3043         } else {
3044
3045                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
3046                 
3047                 yaffs_VerifyBlock(dev,bi,block);
3048
3049                 for (chunkInBlock = 0, oldChunk = block * dev->nChunksPerBlock;
3050                      retVal == YAFFS_OK &&
3051                      chunkInBlock < dev->nChunksPerBlock
3052                      && yaffs_StillSomeChunkBits(dev, block);
3053                      chunkInBlock++, oldChunk++) {
3054                         if (yaffs_CheckChunkBit(dev, block, chunkInBlock)) {
3055
3056                                 /* This page is in use and might need to be copied off */
3057
3058                                 markNAND = 1;
3059
3060                                 yaffs_InitialiseTags(&tags);
3061
3062                                 yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
3063                                                                 buffer, &tags);
3064
3065                                 object =
3066                                     yaffs_FindObjectByNumber(dev,
3067                                                              tags.objectId);
3068
3069                                 T(YAFFS_TRACE_GC_DETAIL,
3070                                   (TSTR
3071                                    ("Collecting page %d, %d %d %d " TENDSTR),
3072                                    chunkInBlock, tags.objectId, tags.chunkId,
3073                                    tags.byteCount));
3074                                    
3075                                 if(object && !yaffs_SkipVerification(dev)){
3076                                         if(tags.chunkId == 0)
3077                                                 matchingChunk = object->hdrChunk;
3078                                         else if(object->softDeleted)
3079                                                 matchingChunk = oldChunk; /* Defeat the test */
3080                                         else
3081                                                 matchingChunk = yaffs_FindChunkInFile(object,tags.chunkId,NULL);
3082                                         
3083                                         if(oldChunk != matchingChunk)
3084                                                 T(YAFFS_TRACE_ERROR,
3085                                                   (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
3086                                                   oldChunk,matchingChunk,tags.objectId, tags.chunkId));
3087                                                 
3088                                 }
3089
3090                                 if (!object) {
3091                                         T(YAFFS_TRACE_ERROR,
3092                                           (TSTR
3093                                            ("page %d in gc has no object: %d %d %d "
3094                                             TENDSTR), oldChunk,
3095                                             tags.objectId, tags.chunkId, tags.byteCount));
3096                                 }
3097
3098                                 if (object && 
3099                                     object->deleted &&
3100                                     object->softDeleted &&
3101                                     tags.chunkId != 0) {
3102                                         /* Data chunk in a soft deleted file, throw it away
3103                                          * It's a soft deleted data chunk,
3104                                          * No need to copy this, just forget about it and 
3105                                          * fix up the object.
3106                                          */
3107
3108                                         object->nDataChunks--;
3109
3110                                         if (object->nDataChunks <= 0) {
3111                                                 /* remeber to clean up the object */
3112                                                 dev->gcCleanupList[cleanups] =
3113                                                     tags.objectId;
3114                                                 cleanups++;
3115                                         }
3116                                         markNAND = 0;
3117                                 } else if (0
3118                                            /* Todo object && object->deleted && object->nDataChunks == 0 */
3119                                            ) {
3120                                         /* Deleted object header with no data chunks.
3121                                          * Can be discarded and the file deleted.
3122                                          */
3123                                         object->hdrChunk = 0;
3124                                         yaffs_FreeTnode(object->myDev,
3125                                                         object->variant.
3126                                                         fileVariant.top);
3127                                         object->variant.fileVariant.top = NULL;
3128                                         yaffs_DoGenericObjectDeletion(object);
3129
3130                                 } else if (object) {
3131                                         /* It's either a data chunk in a live file or
3132                                          * an ObjectHeader, so we're interested in it.
3133                                          * NB Need to keep the ObjectHeaders of deleted files
3134                                          * until the whole file has been deleted off
3135                                          */
3136                                         tags.serialNumber++;
3137
3138                                         dev->nGCCopies++;
3139
3140                                         if (tags.chunkId == 0) {
3141                                                 /* It is an object Id,
3142                                                  * We need to nuke the shrinkheader flags first
3143                                                  * We no longer want the shrinkHeader flag since its work is done
3144                                                  * and if it is left in place it will mess up scanning.
3145                                                  * Also, clear out any shadowing stuff
3146                                                  */
3147
3148                                                 yaffs_ObjectHeader *oh;
3149                                                 oh = (yaffs_ObjectHeader *)buffer;
3150                                                 oh->isShrink = 0;
3151                                                 oh->shadowsObject = oh->inbandShadowsObject = -1;
3152                                                 tags.extraShadows = 0;
3153                                                 tags.extraIsShrinkHeader = 0;
3154                                                 
3155                                                 yaffs_VerifyObjectHeader(object,oh,&tags,1);
3156                                         }
3157
3158                                         newChunk =
3159                                             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
3160
3161                                         if (newChunk < 0) {
3162                                                 retVal = YAFFS_FAIL;
3163                                         } else {
3164
3165                                                 /* Ok, now fix up the Tnodes etc. */
3166
3167                                                 if (tags.chunkId == 0) {
3168                                                         /* It's a header */
3169                                                         object->hdrChunk =  newChunk;
3170                                                         object->serial =   tags.serialNumber;
3171                                                 } else {
3172                                                         /* It's a data chunk */
3173                                                         yaffs_PutChunkIntoFile
3174                                                             (object,
3175                                                              tags.chunkId,
3176                                                              newChunk, 0);
3177                                                 }
3178                                         }
3179                                 }
3180
3181                                 if(retVal == YAFFS_OK)
3182                                         yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
3183
3184                         }
3185                 }
3186
3187                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3188
3189
3190                 /* Do any required cleanups */
3191                 for (i = 0; i < cleanups; i++) {
3192                         /* Time to delete the file too */
3193                         object =
3194                             yaffs_FindObjectByNumber(dev,
3195                                                      dev->gcCleanupList[i]);
3196                         if (object) {
3197                                 yaffs_FreeTnode(dev,
3198                                                 object->variant.fileVariant.
3199                                                 top);
3200                                 object->variant.fileVariant.top = NULL;
3201                                 T(YAFFS_TRACE_GC,
3202                                   (TSTR
3203                                    ("yaffs: About to finally delete object %d"
3204                                     TENDSTR), object->objectId));
3205                                 yaffs_DoGenericObjectDeletion(object);
3206                                 object->myDev->nDeletedFiles--;
3207                         }
3208
3209                 }
3210
3211         }
3212
3213         yaffs_VerifyCollectedBlock(dev,bi,block);
3214           
3215         if (chunksBefore >= (chunksAfter = yaffs_GetErasedChunks(dev))) {
3216                 T(YAFFS_TRACE_GC,
3217                   (TSTR
3218                    ("gc did not increase free chunks before %d after %d"
3219                     TENDSTR), chunksBefore, chunksAfter));
3220         }
3221
3222         dev->isDoingGC = 0;
3223
3224         return retVal;
3225 }
3226
3227 /* New garbage collector
3228  * If we're very low on erased blocks then we do aggressive garbage collection
3229  * otherwise we do "leasurely" garbage collection.
3230  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
3231  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
3232  *
3233  * The idea is to help clear out space in a more spread-out manner.
3234  * Dunno if it really does anything useful.
3235  */
3236 static int yaffs_CheckGarbageCollection(yaffs_Device * dev)
3237 {
3238         int block;
3239         int aggressive;
3240         int gcOk = YAFFS_OK;
3241         int maxTries = 0;
3242         
3243         int checkpointBlockAdjust;
3244
3245         if (dev->isDoingGC) {
3246                 /* Bail out so we don't get recursive gc */
3247                 return YAFFS_OK;
3248         }
3249         
3250         /* This loop should pass the first time.
3251          * We'll only see looping here if the erase of the collected block fails.
3252          */
3253
3254         do {
3255                 maxTries++;
3256                 
3257                 checkpointBlockAdjust = yaffs_CalcCheckpointBlocksRequired(dev) - dev->blocksInCheckpoint;
3258                 if(checkpointBlockAdjust < 0)
3259                         checkpointBlockAdjust = 0;
3260
3261                 if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
3262                         /* We need a block soon...*/
3263                         aggressive = 1;
3264                 } else {
3265                         /* We're in no hurry */
3266                         aggressive = 0;
3267                 }
3268
3269                 block = yaffs_FindBlockForGarbageCollection(dev, aggressive);
3270
3271                 if (block > 0) {
3272                         dev->garbageCollections++;
3273                         if (!aggressive) {
3274                                 dev->passiveGarbageCollections++;
3275                         }
3276
3277                         T(YAFFS_TRACE_GC,
3278                           (TSTR
3279                            ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
3280                            dev->nErasedBlocks, aggressive));
3281
3282                         gcOk = yaffs_GarbageCollectBlock(dev, block);
3283                 }
3284
3285                 if (dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) {
3286                         T(YAFFS_TRACE_GC,
3287                           (TSTR
3288                            ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
3289                             TENDSTR), dev->nErasedBlocks, maxTries, block));
3290                 }
3291         } while ((dev->nErasedBlocks < dev->nReservedBlocks) && (block > 0)
3292                  && (maxTries < 2));
3293
3294         return aggressive ? gcOk : YAFFS_OK;
3295 }
3296
3297 /*-------------------------  TAGS --------------------------------*/
3298
3299 static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
3300                            int chunkInObject)
3301 {
3302         return (tags->chunkId == chunkInObject &&
3303                 tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
3304
3305 }
3306
3307
3308 /*-------------------- Data file manipulation -----------------*/
3309
3310 static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
3311                                  yaffs_ExtendedTags * tags)
3312 {
3313         /*Get the Tnode, then get the level 0 offset chunk offset */
3314         yaffs_Tnode *tn;
3315         int theChunk = -1;
3316         yaffs_ExtendedTags localTags;
3317         int retVal = -1;
3318
3319         yaffs_Device *dev = in->myDev;
3320
3321         if (!tags) {
3322                 /* Passed a NULL, so use our own tags space */
3323                 tags = &localTags;
3324         }
3325
3326         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3327
3328         if (tn) {
3329                 theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
3330
3331                 retVal =
3332                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3333                                            chunkInInode);
3334         }
3335         return retVal;
3336 }
3337
3338 static int yaffs_FindAndDeleteChunkInFile(yaffs_Object * in, int chunkInInode,
3339                                           yaffs_ExtendedTags * tags)
3340 {
3341         /* Get the Tnode, then get the level 0 offset chunk offset */
3342         yaffs_Tnode *tn;
3343         int theChunk = -1;
3344         yaffs_ExtendedTags localTags;
3345
3346         yaffs_Device *dev = in->myDev;
3347         int retVal = -1;
3348
3349         if (!tags) {
3350                 /* Passed a NULL, so use our own tags space */
3351                 tags = &localTags;
3352         }
3353
3354         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3355
3356         if (tn) {
3357
3358                 theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
3359
3360                 retVal =
3361                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3362                                            chunkInInode);
3363
3364                 /* Delete the entry in the filestructure (if found) */
3365                 if (retVal != -1) {
3366                         yaffs_PutLevel0Tnode(dev,tn,chunkInInode,0);
3367                 }
3368         } else {
3369                 /*T(("No level 0 found for %d\n", chunkInInode)); */
3370         }
3371
3372         if (retVal == -1) {
3373                 /* T(("Could not find %d to delete\n",chunkInInode)); */
3374         }
3375         return retVal;
3376 }
3377
3378 #ifdef YAFFS_PARANOID
3379
3380 static int yaffs_CheckFileSanity(yaffs_Object * in)
3381 {
3382         int chunk;
3383         int nChunks;
3384         int fSize;
3385         int failed = 0;
3386         int objId;
3387         yaffs_Tnode *tn;
3388         yaffs_Tags localTags;
3389         yaffs_Tags *tags = &localTags;
3390         int theChunk;
3391         int chunkDeleted;
3392
3393         if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
3394                 /* T(("Object not a file\n")); */
3395                 return YAFFS_FAIL;
3396         }
3397
3398         objId = in->objectId;
3399         fSize = in->variant.fileVariant.fileSize;
3400         nChunks =
3401             (fSize + in->myDev->nDataBytesPerChunk - 1) / in->myDev->nDataBytesPerChunk;
3402
3403         for (chunk = 1; chunk <= nChunks; chunk++) {
3404                 tn = yaffs_FindLevel0Tnode(in->myDev, &in->variant.fileVariant,
3405                                            chunk);
3406
3407                 if (tn) {
3408
3409                         theChunk = yaffs_GetChunkGroupBase(dev,tn,chunk);
3410
3411                         if (yaffs_CheckChunkBits
3412                             (dev, theChunk / dev->nChunksPerBlock,
3413                              theChunk % dev->nChunksPerBlock)) {
3414
3415                                 yaffs_ReadChunkTagsFromNAND(in->myDev, theChunk,
3416                                                             tags,
3417                                                             &chunkDeleted);
3418                                 if (yaffs_TagsMatch
3419                                     (tags, in->objectId, chunk, chunkDeleted)) {
3420                                         /* found it; */
3421
3422                                 }
3423                         } else {
3424
3425                                 failed = 1;
3426                         }
3427
3428                 } else {
3429                         /* T(("No level 0 found for %d\n", chunk)); */
3430                 }
3431         }
3432
3433         return failed ? YAFFS_FAIL : YAFFS_OK;
3434 }
3435
3436 #endif
3437
3438 static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
3439                                   int chunkInNAND, int inScan)
3440 {
3441         /* NB inScan is zero unless scanning. 
3442          * For forward scanning, inScan is > 0; 
3443          * for backward scanning inScan is < 0
3444          */
3445          
3446         yaffs_Tnode *tn;
3447         yaffs_Device *dev = in->myDev;
3448         int existingChunk;
3449         yaffs_ExtendedTags existingTags;
3450         yaffs_ExtendedTags newTags;
3451         unsigned existingSerial, newSerial;
3452
3453         if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
3454                 /* Just ignore an attempt at putting a chunk into a non-file during scanning
3455                  * If it is not during Scanning then something went wrong!
3456                  */
3457                 if (!inScan) {
3458                         T(YAFFS_TRACE_ERROR,
3459                           (TSTR
3460                            ("yaffs tragedy:attempt to put data chunk into a non-file"
3461                             TENDSTR)));
3462                         YBUG();
3463                 }
3464
3465                 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
3466                 return YAFFS_OK;
3467         }
3468
3469         tn = yaffs_AddOrFindLevel0Tnode(dev, 
3470                                         &in->variant.fileVariant,
3471                                         chunkInInode,
3472                                         NULL);
3473         if (!tn) {
3474                 return YAFFS_FAIL;
3475         }
3476
3477         existingChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
3478
3479         if (inScan != 0) {
3480                 /* If we're scanning then we need to test for duplicates
3481                  * NB This does not need to be efficient since it should only ever 
3482                  * happen when the power fails during a write, then only one
3483                  * chunk should ever be affected.
3484                  *
3485                  * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
3486                  * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
3487                  */
3488
3489                 if (existingChunk > 0) {
3490                         /* NB Right now existing chunk will not be real chunkId if the device >= 32MB
3491                          *    thus we have to do a FindChunkInFile to get the real chunk id.
3492                          *
3493                          * We have a duplicate now we need to decide which one to use:
3494                          *
3495                          * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
3496                          * Forward scanning YAFFS2: The new one is what we use, dump the old one.
3497                          * YAFFS1: Get both sets of tags and compare serial numbers.
3498                          */
3499
3500                         if (inScan > 0) {
3501                                 /* Only do this for forward scanning */
3502                                 yaffs_ReadChunkWithTagsFromNAND(dev,
3503                                                                 chunkInNAND,
3504                                                                 NULL, &newTags);
3505
3506                                 /* Do a proper find */
3507                                 existingChunk =
3508                                     yaffs_FindChunkInFile(in, chunkInInode,
3509                                                           &existingTags);
3510                         }
3511
3512                         if (existingChunk <= 0) {
3513                                 /*Hoosterman - how did this happen? */
3514
3515                                 T(YAFFS_TRACE_ERROR,
3516                                   (TSTR
3517                                    ("yaffs tragedy: existing chunk < 0 in scan"
3518                                     TENDSTR)));
3519
3520                         }
3521
3522                         /* NB The deleted flags should be false, otherwise the chunks will 
3523                          * not be loaded during a scan
3524                          */
3525
3526                         if(inScan > 0) {
3527                                 newSerial = newTags.serialNumber;
3528                                 existingSerial = existingTags.serialNumber;
3529                         }
3530
3531                         if ((inScan > 0) &&
3532                             (in->myDev->isYaffs2 ||
3533                              existingChunk <= 0 ||
3534                              ((existingSerial + 1) & 3) == newSerial)) {
3535                                 /* Forward scanning.                            
3536                                  * Use new
3537                                  * Delete the old one and drop through to update the tnode
3538                                  */
3539                                 yaffs_DeleteChunk(dev, existingChunk, 1,
3540                                                   __LINE__);
3541                         } else {
3542                                 /* Backward scanning or we want to use the existing one
3543                                  * Use existing.
3544                                  * Delete the new one and return early so that the tnode isn't changed
3545                                  */
3546                                 yaffs_DeleteChunk(dev, chunkInNAND, 1,
3547                                                   __LINE__);
3548                                 return YAFFS_OK;
3549                         }
3550                 }
3551
3552         }
3553
3554         if (existingChunk == 0) {
3555                 in->nDataChunks++;
3556         }
3557
3558         yaffs_PutLevel0Tnode(dev,tn,chunkInInode,chunkInNAND);
3559
3560         return YAFFS_OK;
3561 }
3562
3563 static int yaffs_ReadChunkDataFromObject(yaffs_Object * in, int chunkInInode,
3564                                          __u8 * buffer)
3565 {
3566         int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);
3567
3568         if (chunkInNAND >= 0) {
3569                 return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
3570                                                        buffer,NULL);
3571         } else {
3572                 T(YAFFS_TRACE_NANDACCESS,
3573                   (TSTR("Chunk %d not found zero instead" TENDSTR),
3574                    chunkInNAND));
3575                 /* get sane (zero) data if you read a hole */
3576                 memset(buffer, 0, in->myDev->nDataBytesPerChunk);       
3577                 return 0;
3578         }
3579
3580 }
3581
3582 void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn)
3583 {
3584         int block;
3585         int page;
3586         yaffs_ExtendedTags tags;
3587         yaffs_BlockInfo *bi;
3588
3589         if (chunkId <= 0)
3590                 return;
3591                 
3592
3593         dev->nDeletions++;
3594         block = chunkId / dev->nChunksPerBlock;
3595         page = chunkId % dev->nChunksPerBlock;
3596
3597
3598         if(!yaffs_CheckChunkBit(dev,block,page))
3599                 T(YAFFS_TRACE_VERIFY,
3600                         (TSTR("Deleting invalid chunk %d"TENDSTR),
3601                          chunkId));
3602
3603         bi = yaffs_GetBlockInfo(dev, block);
3604
3605         T(YAFFS_TRACE_DELETION,
3606           (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
3607
3608         if (markNAND &&
3609             bi->blockState != YAFFS_BLOCK_STATE_COLLECTING && !dev->isYaffs2) {
3610
3611                 yaffs_InitialiseTags(&tags);
3612
3613                 tags.chunkDeleted = 1;
3614
3615                 yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
3616                 yaffs_HandleUpdateChunk(dev, chunkId, &tags);
3617         } else {
3618                 dev->nUnmarkedDeletions++;
3619         }
3620
3621         /* Pull out of the management area.
3622          * If the whole block became dirty, this will kick off an erasure.
3623          */
3624         if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
3625             bi->blockState == YAFFS_BLOCK_STATE_FULL ||
3626             bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
3627             bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
3628                 dev->nFreeChunks++;
3629
3630                 yaffs_ClearChunkBit(dev, block, page);
3631
3632                 bi->pagesInUse--;
3633
3634                 if (bi->pagesInUse == 0 &&
3635                     !bi->hasShrinkHeader &&
3636                     bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
3637                     bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
3638                         yaffs_BlockBecameDirty(dev, block);
3639                 }
3640
3641         } else {
3642                 /* T(("Bad news deleting chunk %d\n",chunkId)); */
3643         }
3644
3645 }
3646
3647 static int yaffs_WriteChunkDataToObject(yaffs_Object * in, int chunkInInode,
3648                                         const __u8 * buffer, int nBytes,
3649                                         int useReserve)
3650 {
3651         /* Find old chunk Need to do this to get serial number
3652          * Write new one and patch into tree.
3653          * Invalidate old tags.
3654          */
3655
3656         int prevChunkId;
3657         yaffs_ExtendedTags prevTags;
3658
3659         int newChunkId;
3660         yaffs_ExtendedTags newTags;
3661
3662         yaffs_Device *dev = in->myDev;
3663
3664         yaffs_CheckGarbageCollection(dev);
3665
3666         /* Get the previous chunk at this location in the file if it exists */
3667         prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);
3668
3669         /* Set up new tags */
3670         yaffs_InitialiseTags(&newTags);
3671
3672         newTags.chunkId = chunkInInode;
3673         newTags.objectId = in->objectId;
3674         newTags.serialNumber =
3675             (prevChunkId >= 0) ? prevTags.serialNumber + 1 : 1;
3676         newTags.byteCount = nBytes;
3677         
3678         if(nBytes < 1 || nBytes > dev->totalBytesPerChunk){
3679           T(YAFFS_TRACE_ERROR,
3680           (TSTR("Writing %d bytes to chunk!!!!!!!!!" TENDSTR), nBytes));
3681           while(1){}
3682         }
3683         
3684         
3685
3686         newChunkId =
3687             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3688                                               useReserve);
3689
3690         if (newChunkId >= 0) {
3691                 yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);
3692
3693                 if (prevChunkId >= 0) {
3694                         yaffs_DeleteChunk(dev, prevChunkId, 1, __LINE__);
3695
3696                 }
3697
3698                 yaffs_CheckFileSanity(in);
3699         }
3700         return newChunkId;
3701
3702 }
3703
3704 /* UpdateObjectHeader updates the header on NAND for an object.
3705  * If name is not NULL, then that new name is used.
3706  */
3707 int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
3708                              int isShrink, int shadows)
3709 {
3710
3711         yaffs_BlockInfo *bi;
3712
3713         yaffs_Device *dev = in->myDev;
3714
3715         int prevChunkId;
3716         int retVal = 0;
3717         int result = 0;
3718
3719         int newChunkId;
3720         yaffs_ExtendedTags newTags;
3721         yaffs_ExtendedTags oldTags;
3722
3723         __u8 *buffer = NULL;
3724         YCHAR oldName[YAFFS_MAX_NAME_LENGTH + 1];
3725
3726         yaffs_ObjectHeader *oh = NULL;
3727         
3728         yaffs_strcpy(oldName,_Y("silly old name"));
3729
3730
3731         if (!in->fake || 
3732             in == dev->rootDir || /* The rootDir should also be saved */
3733             force) {
3734
3735                 yaffs_CheckGarbageCollection(dev);
3736                 yaffs_CheckObjectDetailsLoaded(in);
3737
3738                 buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
3739                 oh = (yaffs_ObjectHeader *) buffer;
3740
3741                 prevChunkId = in->hdrChunk;
3742
3743                 if (prevChunkId > 0) {
3744                         result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
3745                                                         buffer, &oldTags);
3746                         
3747                         yaffs_VerifyObjectHeader(in,oh,&oldTags,0);
3748                                                                                 
3749                         memcpy(oldName, oh->name, sizeof(oh->name));
3750                 }
3751
3752                 memset(buffer, 0xFF, dev->nDataBytesPerChunk);
3753
3754                 oh->type = in->variantType;
3755                 oh->yst_mode = in->yst_mode;
3756                 oh->shadowsObject = oh->inbandShadowsObject = shadows;
3757
3758 #ifdef CONFIG_YAFFS_WINCE
3759                 oh->win_atime[0] = in->win_atime[0];
3760                 oh->win_ctime[0] = in->win_ctime[0];
3761                 oh->win_mtime[0] = in->win_mtime[0];
3762                 oh->win_atime[1] = in->win_atime[1];
3763                 oh->win_ctime[1] = in->win_ctime[1];
3764                 oh->win_mtime[1] = in->win_mtime[1];
3765 #else
3766                 oh->yst_uid = in->yst_uid;
3767                 oh->yst_gid = in->yst_gid;
3768                 oh->yst_atime = in->yst_atime;
3769                 oh->yst_mtime = in->yst_mtime;
3770                 oh->yst_ctime = in->yst_ctime;
3771                 oh->yst_rdev = in->yst_rdev;
3772 #endif
3773                 if (in->parent) {
3774                         oh->parentObjectId = in->parent->objectId;
3775                 } else {
3776                         oh->parentObjectId = 0;
3777                 }
3778
3779                 if (name && *name) {
3780                         memset(oh->name, 0, sizeof(oh->name));
3781                         yaffs_strncpy(oh->name, name, YAFFS_MAX_NAME_LENGTH);
3782                 } else if (prevChunkId>=0) {
3783                         memcpy(oh->name, oldName, sizeof(oh->name));
3784                 } else {
3785                         memset(oh->name, 0, sizeof(oh->name));
3786                 }
3787
3788                 oh->isShrink = isShrink;
3789
3790                 switch (in->variantType) {
3791                 case YAFFS_OBJECT_TYPE_UNKNOWN:
3792                         /* Should not happen */
3793                         break;
3794                 case YAFFS_OBJECT_TYPE_FILE:
3795                         oh->fileSize =
3796                             (oh->parentObjectId == YAFFS_OBJECTID_DELETED
3797                              || oh->parentObjectId ==
3798                              YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.
3799                             fileVariant.fileSize;
3800                         break;
3801                 case YAFFS_OBJECT_TYPE_HARDLINK:
3802                         oh->equivalentObjectId =
3803                             in->variant.hardLinkVariant.equivalentObjectId;
3804                         break;
3805                 case YAFFS_OBJECT_TYPE_SPECIAL:
3806                         /* Do nothing */
3807                         break;
3808                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3809                         /* Do nothing */
3810                         break;
3811                 case YAFFS_OBJECT_TYPE_SYMLINK:
3812                         yaffs_strncpy(oh->alias,
3813                                       in->variant.symLinkVariant.alias,
3814                                       YAFFS_MAX_ALIAS_LENGTH);
3815                         oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3816                         break;
3817                 }
3818
3819                 /* Tags */
3820                 yaffs_InitialiseTags(&newTags);
3821                 in->serial++;
3822                 newTags.chunkId = 0;
3823                 newTags.objectId = in->objectId;
3824                 newTags.serialNumber = in->serial;
3825
3826                 /* Add extra info for file header */
3827
3828                 newTags.extraHeaderInfoAvailable = 1;
3829                 newTags.extraParentObjectId = oh->parentObjectId;
3830                 newTags.extraFileLength = oh->fileSize;
3831                 newTags.extraIsShrinkHeader = oh->isShrink;
3832                 newTags.extraEquivalentObjectId = oh->equivalentObjectId;
3833                 newTags.extraShadows = (oh->shadowsObject > 0) ? 1 : 0;
3834                 newTags.extraObjectType = in->variantType;
3835
3836                 yaffs_VerifyObjectHeader(in,oh,&newTags,1);
3837
3838                 /* Create new chunk in NAND */
3839                 newChunkId =
3840                     yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3841                                                       (prevChunkId >= 0) ? 1 : 0);
3842
3843                 if (newChunkId >= 0) {
3844
3845                         in->hdrChunk = newChunkId;
3846
3847                         if (prevChunkId >= 0) {
3848                                 yaffs_DeleteChunk(dev, prevChunkId, 1,
3849                                                   __LINE__);
3850                         }
3851
3852                         if(!yaffs_ObjectHasCachedWriteData(in))
3853                                 in->dirty = 0;
3854
3855                         /* If this was a shrink, then mark the block that the chunk lives on */
3856                         if (isShrink) {
3857                                 bi = yaffs_GetBlockInfo(in->myDev,
3858                                                         newChunkId /in->myDev-> nChunksPerBlock);
3859                                 bi->hasShrinkHeader = 1;
3860                         }
3861
3862                 }
3863
3864                 retVal = newChunkId;
3865
3866         }
3867
3868         if (buffer)
3869                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3870
3871         return retVal;
3872 }
3873
3874 /*------------------------ Short Operations Cache ----------------------------------------
3875  *   In many situations where there is no high level buffering (eg WinCE) a lot of
3876  *   reads might be short sequential reads, and a lot of writes may be short 
3877  *   sequential writes. eg. scanning/writing a jpeg file.
3878  *   In these cases, a short read/write cache can provide a huge perfomance benefit 
3879  *   with dumb-as-a-rock code.
3880  *   In Linux, the page cache&