Fix problem where symllink alias pointer was being used after free
[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 1.96 2009-12-03 03:42:28 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 #define YAFFS_PASSIVE_GC_CHUNKS 2
37
38 #include "yaffs_ecc.h"
39
40
41 /* Robustification (if it ever comes about...) */
42 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND);
43 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
44                 int erasedOk);
45 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
46                                 const __u8 *data,
47                                 const yaffs_ExtendedTags *tags);
48 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
49                                 const yaffs_ExtendedTags *tags);
50
51 /* Other local prototypes */
52 static void yaffs_UpdateParent(yaffs_Object *obj);
53 static int yaffs_UnlinkObject(yaffs_Object *obj);
54 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);
55
56 static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList);
57
58 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev,
59                                         const __u8 *buffer,
60                                         yaffs_ExtendedTags *tags,
61                                         int useReserve);
62 static int yaffs_PutChunkIntoFile(yaffs_Object *in, int chunkInInode,
63                                 int chunkInNAND, int inScan);
64
65 static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
66                                         yaffs_ObjectType type);
67 static void yaffs_AddObjectToDirectory(yaffs_Object *directory,
68                                 yaffs_Object *obj);
69 static int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name,
70                                 int force, int isShrink, int shadows);
71 static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
72 static int yaffs_CheckStructures(void);
73 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
74                         int chunkOffset, int *limit);
75 static int yaffs_DoGenericObjectDeletion(yaffs_Object *in);
76
77 static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device *dev, int blockNo);
78
79
80 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
81                                 int chunkInNAND);
82
83 static int yaffs_UnlinkWorker(yaffs_Object *obj);
84
85 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
86                         int chunkInObject);
87
88 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
89                                 yaffs_BlockInfo **blockUsedPtr);
90
91 static void yaffs_VerifyFreeChunks(yaffs_Device *dev);
92
93 static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
94
95 static void yaffs_VerifyDirectory(yaffs_Object *directory);
96 #ifdef YAFFS_PARANOID
97 static int yaffs_CheckFileSanity(yaffs_Object *in);
98 #else
99 #define yaffs_CheckFileSanity(in)
100 #endif
101
102 static void yaffs_InvalidateWholeChunkCache(yaffs_Object *in);
103 static void yaffs_InvalidateChunkCache(yaffs_Object *object, int chunkId);
104
105 static void yaffs_InvalidateCheckpoint(yaffs_Device *dev);
106
107 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
108                                 yaffs_ExtendedTags *tags);
109
110 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn,
111                 unsigned pos);
112 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,
113                                         yaffs_FileStructure *fStruct,
114                                         __u32 chunkId);
115
116 /* Function to calculate chunk and offset */
117
118 static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, int *chunkOut,
119                 __u32 *offsetOut)
120 {
121         int chunk;
122         __u32 offset;
123
124         chunk  = (__u32)(addr >> dev->chunkShift);
125
126         if (dev->chunkDiv == 1) {
127                 /* easy power of 2 case */
128                 offset = (__u32)(addr & dev->chunkMask);
129         } else {
130                 /* Non power-of-2 case */
131
132                 loff_t chunkBase;
133
134                 chunk /= dev->chunkDiv;
135
136                 chunkBase = ((loff_t)chunk) * dev->nDataBytesPerChunk;
137                 offset = (__u32)(addr - chunkBase);
138         }
139
140         *chunkOut = chunk;
141         *offsetOut = offset;
142 }
143
144 /* Function to return the number of shifts for a power of 2 greater than or
145  * equal to the given number
146  * Note we don't try to cater for all possible numbers and this does not have to
147  * be hellishly efficient.
148  */
149
150 static __u32 ShiftsGE(__u32 x)
151 {
152         int extraBits;
153         int nShifts;
154
155         nShifts = extraBits = 0;
156
157         while (x > 1) {
158                 if (x & 1)
159                         extraBits++;
160                 x >>= 1;
161                 nShifts++;
162         }
163
164         if (extraBits)
165                 nShifts++;
166
167         return nShifts;
168 }
169
170 /* Function to return the number of shifts to get a 1 in bit 0
171  */
172
173 static __u32 Shifts(__u32 x)
174 {
175         int nShifts;
176
177         nShifts =  0;
178
179         if (!x)
180                 return 0;
181
182         while (!(x&1)) {
183                 x >>= 1;
184                 nShifts++;
185         }
186
187         return nShifts;
188 }
189
190
191
192 /*
193  * Temporary buffer manipulations.
194  */
195
196 static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)
197 {
198         int i;
199         __u8 *buf = (__u8 *)1;
200
201         memset(dev->tempBuffer, 0, sizeof(dev->tempBuffer));
202
203         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
204                 dev->tempBuffer[i].line = 0;    /* not in use */
205                 dev->tempBuffer[i].buffer = buf =
206                     YMALLOC_DMA(dev->totalBytesPerChunk);
207         }
208
209         return buf ? YAFFS_OK : YAFFS_FAIL;
210 }
211
212 __u8 *yaffs_GetTempBuffer(yaffs_Device *dev, int lineNo)
213 {
214         int i, j;
215
216         dev->tempInUse++;
217         if (dev->tempInUse > dev->maxTemp)
218                 dev->maxTemp = dev->tempInUse;
219
220         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
221                 if (dev->tempBuffer[i].line == 0) {
222                         dev->tempBuffer[i].line = lineNo;
223                         if ((i + 1) > dev->maxTemp) {
224                                 dev->maxTemp = i + 1;
225                                 for (j = 0; j <= i; j++)
226                                         dev->tempBuffer[j].maxLine =
227                                             dev->tempBuffer[j].line;
228                         }
229
230                         return dev->tempBuffer[i].buffer;
231                 }
232         }
233
234         T(YAFFS_TRACE_BUFFERS,
235           (TSTR("Out of temp buffers at line %d, other held by lines:"),
236            lineNo));
237         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
238                 T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
239
240         T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
241
242         /*
243          * If we got here then we have to allocate an unmanaged one
244          * This is not good.
245          */
246
247         dev->unmanagedTempAllocations++;
248         return YMALLOC(dev->nDataBytesPerChunk);
249
250 }
251
252 void yaffs_ReleaseTempBuffer(yaffs_Device *dev, __u8 *buffer,
253                                     int lineNo)
254 {
255         int i;
256
257         dev->tempInUse--;
258
259         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
260                 if (dev->tempBuffer[i].buffer == buffer) {
261                         dev->tempBuffer[i].line = 0;
262                         return;
263                 }
264         }
265
266         if (buffer) {
267                 /* assume it is an unmanaged one. */
268                 T(YAFFS_TRACE_BUFFERS,
269                   (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
270                    lineNo));
271                 YFREE(buffer);
272                 dev->unmanagedTempDeallocations++;
273         }
274
275 }
276
277 /*
278  * Determine if we have a managed buffer.
279  */
280 int yaffs_IsManagedTempBuffer(yaffs_Device *dev, const __u8 *buffer)
281 {
282         int i;
283
284         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
285                 if (dev->tempBuffer[i].buffer == buffer)
286                         return 1;
287         }
288
289         for (i = 0; i < dev->nShortOpCaches; i++) {
290                 if (dev->srCache[i].data == buffer)
291                         return 1;
292         }
293
294         if (buffer == dev->checkpointBuffer)
295                 return 1;
296
297         T(YAFFS_TRACE_ALWAYS,
298                 (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
299         return 0;
300 }
301
302
303
304 /*
305  * Chunk bitmap manipulations
306  */
307
308 static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device *dev, int blk)
309 {
310         if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
311                 T(YAFFS_TRACE_ERROR,
312                         (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
313                         blk));
314                 YBUG();
315         }
316         return dev->chunkBits +
317                 (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
318 }
319
320 static Y_INLINE void yaffs_VerifyChunkBitId(yaffs_Device *dev, int blk, int chunk)
321 {
322         if (blk < dev->internalStartBlock || blk > dev->internalEndBlock ||
323                         chunk < 0 || chunk >= dev->nChunksPerBlock) {
324                 T(YAFFS_TRACE_ERROR,
325                 (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),
326                         blk, chunk));
327                 YBUG();
328         }
329 }
330
331 static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device *dev, int blk)
332 {
333         __u8 *blkBits = yaffs_BlockBits(dev, blk);
334
335         memset(blkBits, 0, dev->chunkBitmapStride);
336 }
337
338 static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device *dev, int blk, int chunk)
339 {
340         __u8 *blkBits = yaffs_BlockBits(dev, blk);
341
342         yaffs_VerifyChunkBitId(dev, blk, chunk);
343
344         blkBits[chunk / 8] &= ~(1 << (chunk & 7));
345 }
346
347 static Y_INLINE void yaffs_SetChunkBit(yaffs_Device *dev, int blk, int chunk)
348 {
349         __u8 *blkBits = yaffs_BlockBits(dev, blk);
350
351         yaffs_VerifyChunkBitId(dev, blk, chunk);
352
353         blkBits[chunk / 8] |= (1 << (chunk & 7));
354 }
355
356 static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device *dev, int blk, int chunk)
357 {
358         __u8 *blkBits = yaffs_BlockBits(dev, blk);
359         yaffs_VerifyChunkBitId(dev, blk, chunk);
360
361         return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
362 }
363
364 static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device *dev, int blk)
365 {
366         __u8 *blkBits = yaffs_BlockBits(dev, blk);
367         int i;
368         for (i = 0; i < dev->chunkBitmapStride; i++) {
369                 if (*blkBits)
370                         return 1;
371                 blkBits++;
372         }
373         return 0;
374 }
375
376 static int yaffs_CountChunkBits(yaffs_Device *dev, int blk)
377 {
378         __u8 *blkBits = yaffs_BlockBits(dev, blk);
379         int i;
380         int n = 0;
381         for (i = 0; i < dev->chunkBitmapStride; i++) {
382                 __u8 x = *blkBits;
383                 while (x) {
384                         if (x & 1)
385                                 n++;
386                         x >>= 1;
387                 }
388
389                 blkBits++;
390         }
391         return n;
392 }
393
394 /*
395  * Verification code
396  */
397
398 static int yaffs_SkipVerification(yaffs_Device *dev)
399 {
400         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
401 }
402
403 static int yaffs_SkipFullVerification(yaffs_Device *dev)
404 {
405         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_FULL));
406 }
407
408 static int yaffs_SkipNANDVerification(yaffs_Device *dev)
409 {
410         return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_NAND));
411 }
412
413 static const char *blockStateName[] = {
414 "Unknown",
415 "Needs scanning",
416 "Scanning",
417 "Empty",
418 "Allocating",
419 "Full",
420 "Dirty",
421 "Checkpoint",
422 "Collecting",
423 "Dead"
424 };
425
426 static void yaffs_VerifyBlock(yaffs_Device *dev, yaffs_BlockInfo *bi, int n)
427 {
428         int actuallyUsed;
429         int inUse;
430
431         if (yaffs_SkipVerification(dev))
432                 return;
433
434         /* Report illegal runtime states */
435         if (bi->blockState >= YAFFS_NUMBER_OF_BLOCK_STATES)
436                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has undefined state %d"TENDSTR), n, bi->blockState));
437
438         switch (bi->blockState) {
439         case YAFFS_BLOCK_STATE_UNKNOWN:
440         case YAFFS_BLOCK_STATE_SCANNING:
441         case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
442                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has bad run-state %s"TENDSTR),
443                 n, blockStateName[bi->blockState]));
444         }
445
446         /* Check pages in use and soft deletions are legal */
447
448         actuallyUsed = bi->pagesInUse - bi->softDeletions;
449
450         if (bi->pagesInUse < 0 || bi->pagesInUse > dev->nChunksPerBlock ||
451            bi->softDeletions < 0 || bi->softDeletions > dev->nChunksPerBlock ||
452            actuallyUsed < 0 || actuallyUsed > dev->nChunksPerBlock)
453                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has illegal values pagesInUsed %d softDeletions %d"TENDSTR),
454                 n, bi->pagesInUse, bi->softDeletions));
455
456
457         /* Check chunk bitmap legal */
458         inUse = yaffs_CountChunkBits(dev, n);
459         if (inUse != bi->pagesInUse)
460                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has inconsistent values pagesInUse %d counted chunk bits %d"TENDSTR),
461                         n, bi->pagesInUse, inUse));
462
463         /* Check that the sequence number is valid.
464          * Ten million is legal, but is very unlikely
465          */
466         if (dev->isYaffs2 &&
467            (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING || bi->blockState == YAFFS_BLOCK_STATE_FULL) &&
468            (bi->sequenceNumber < YAFFS_LOWEST_SEQUENCE_NUMBER || bi->sequenceNumber > 10000000))
469                 T(YAFFS_TRACE_VERIFY, (TSTR("Block %d has suspect sequence number of %d"TENDSTR),
470                 n, bi->sequenceNumber));
471 }
472
473 static void yaffs_VerifyCollectedBlock(yaffs_Device *dev, yaffs_BlockInfo *bi,
474                 int n)
475 {
476         yaffs_VerifyBlock(dev, bi, n);
477
478         /* After collection the block should be in the erased state */
479         /* This will need to change if we do partial gc */
480
481         if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING &&
482                         bi->blockState != YAFFS_BLOCK_STATE_EMPTY) {
483                 T(YAFFS_TRACE_ERROR, (TSTR("Block %d is in state %d after gc, should be erased"TENDSTR),
484                         n, bi->blockState));
485         }
486 }
487
488 static void yaffs_VerifyBlocks(yaffs_Device *dev)
489 {
490         int i;
491         int nBlocksPerState[YAFFS_NUMBER_OF_BLOCK_STATES];
492         int nIllegalBlockStates = 0;
493
494         if (yaffs_SkipVerification(dev))
495                 return;
496
497         memset(nBlocksPerState, 0, sizeof(nBlocksPerState));
498
499         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
500                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, i);
501                 yaffs_VerifyBlock(dev, bi, i);
502
503                 if (bi->blockState < YAFFS_NUMBER_OF_BLOCK_STATES)
504                         nBlocksPerState[bi->blockState]++;
505                 else
506                         nIllegalBlockStates++;
507         }
508
509         T(YAFFS_TRACE_VERIFY, (TSTR(""TENDSTR)));
510         T(YAFFS_TRACE_VERIFY, (TSTR("Block summary"TENDSTR)));
511
512         T(YAFFS_TRACE_VERIFY, (TSTR("%d blocks have illegal states"TENDSTR), nIllegalBlockStates));
513         if (nBlocksPerState[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
514                 T(YAFFS_TRACE_VERIFY, (TSTR("Too many allocating blocks"TENDSTR)));
515
516         for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
517                 T(YAFFS_TRACE_VERIFY,
518                   (TSTR("%s %d blocks"TENDSTR),
519                   blockStateName[i], nBlocksPerState[i]));
520
521         if (dev->blocksInCheckpoint != nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT])
522                 T(YAFFS_TRACE_VERIFY,
523                  (TSTR("Checkpoint block count wrong dev %d count %d"TENDSTR),
524                  dev->blocksInCheckpoint, nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT]));
525
526         if (dev->nErasedBlocks != nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY])
527                 T(YAFFS_TRACE_VERIFY,
528                  (TSTR("Erased block count wrong dev %d count %d"TENDSTR),
529                  dev->nErasedBlocks, nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY]));
530
531         if (nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
532                 T(YAFFS_TRACE_VERIFY,
533                  (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
534                  nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));
535
536         T(YAFFS_TRACE_VERIFY, (TSTR(""TENDSTR)));
537
538 }
539
540 /*
541  * Verify the object header. oh must be valid, but obj and tags may be NULL in which
542  * case those tests will not be performed.
543  */
544 static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
545 {
546         if (obj && yaffs_SkipVerification(obj->myDev))
547                 return;
548
549         if (!(tags && obj && oh)) {
550                 T(YAFFS_TRACE_VERIFY,
551                                 (TSTR("Verifying object header tags %x obj %x oh %x"TENDSTR),
552                                 (__u32)tags, (__u32)obj, (__u32)oh));
553                 return;
554         }
555
556         if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
557                         oh->type > YAFFS_OBJECT_TYPE_MAX)
558                 T(YAFFS_TRACE_VERIFY,
559                         (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
560                         tags->objectId, oh->type));
561
562         if (tags->objectId != obj->objectId)
563                 T(YAFFS_TRACE_VERIFY,
564                         (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
565                         tags->objectId, obj->objectId));
566
567
568         /*
569          * Check that the object's parent ids match if parentCheck requested.
570          *
571          * Tests do not apply to the root object.
572          */
573
574         if (parentCheck && tags->objectId > 1 && !obj->parent)
575                 T(YAFFS_TRACE_VERIFY,
576                         (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
577                         tags->objectId, oh->parentObjectId));
578
579         if (parentCheck && obj->parent &&
580                         oh->parentObjectId != obj->parent->objectId &&
581                         (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
582                         obj->parent->objectId != YAFFS_OBJECTID_DELETED))
583                 T(YAFFS_TRACE_VERIFY,
584                         (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
585                         tags->objectId, oh->parentObjectId, obj->parent->objectId));
586
587         if (tags->objectId > 1 && oh->name[0] == 0) /* Null name */
588                 T(YAFFS_TRACE_VERIFY,
589                         (TSTR("Obj %d header name is NULL"TENDSTR),
590                         obj->objectId));
591
592         if (tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
593                 T(YAFFS_TRACE_VERIFY,
594                         (TSTR("Obj %d header name is 0xFF"TENDSTR),
595                         obj->objectId));
596 }
597
598
599
600 static int yaffs_VerifyTnodeWorker(yaffs_Object *obj, yaffs_Tnode *tn,
601                                         __u32 level, int chunkOffset)
602 {
603         int i;
604         yaffs_Device *dev = obj->myDev;
605         int ok = 1;
606
607         if (tn) {
608                 if (level > 0) {
609
610                         for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
611                                 if (tn->internal[i]) {
612                                         ok = yaffs_VerifyTnodeWorker(obj,
613                                                         tn->internal[i],
614                                                         level - 1,
615                                                         (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
616                                 }
617                         }
618                 } else if (level == 0) {
619                         yaffs_ExtendedTags tags;
620                         __u32 objectId = obj->objectId;
621
622                         chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
623
624                         for (i = 0; i < YAFFS_NTNODES_LEVEL0; i++) {
625                                 __u32 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
626
627                                 if (theChunk > 0) {
628                                         /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
629                                         yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL, &tags);
630                                         if (tags.objectId != objectId || tags.chunkId != chunkOffset) {
631                                                 T(~0, (TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
632                                                         objectId, chunkOffset, theChunk,
633                                                         tags.objectId, tags.chunkId));
634                                         }
635                                 }
636                                 chunkOffset++;
637                         }
638                 }
639         }
640
641         return ok;
642
643 }
644
645
646 static void yaffs_VerifyFile(yaffs_Object *obj)
647 {
648         int requiredTallness;
649         int actualTallness;
650         __u32 lastChunk;
651         __u32 x;
652         __u32 i;
653         yaffs_Device *dev;
654         yaffs_ExtendedTags tags;
655         yaffs_Tnode *tn;
656         __u32 objectId;
657
658         if (!obj)
659                 return;
660
661         if (yaffs_SkipVerification(obj->myDev))
662                 return;
663
664         dev = obj->myDev;
665         objectId = obj->objectId;
666
667         /* Check file size is consistent with tnode depth */
668         lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
669         x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
670         requiredTallness = 0;
671         while (x > 0) {
672                 x >>= YAFFS_TNODES_INTERNAL_BITS;
673                 requiredTallness++;
674         }
675
676         actualTallness = obj->variant.fileVariant.topLevel;
677
678         if (requiredTallness > actualTallness)
679                 T(YAFFS_TRACE_VERIFY,
680                 (TSTR("Obj %d had tnode tallness %d, needs to be %d"TENDSTR),
681                  obj->objectId, actualTallness, requiredTallness));
682
683
684         /* Check that the chunks in the tnode tree are all correct.
685          * We do this by scanning through the tnode tree and
686          * checking the tags for every chunk match.
687          */
688
689         if (yaffs_SkipNANDVerification(dev))
690                 return;
691
692         for (i = 1; i <= lastChunk; i++) {
693                 tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant, i);
694
695                 if (tn) {
696                         __u32 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
697                         if (theChunk > 0) {
698                                 /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
699                                 yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL, &tags);
700                                 if (tags.objectId != objectId || tags.chunkId != i) {
701                                         T(~0, (TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
702                                                 objectId, i, theChunk,
703                                                 tags.objectId, tags.chunkId));
704                                 }
705                         }
706                 }
707         }
708 }
709
710
711 static void yaffs_VerifyHardLink(yaffs_Object *obj)
712 {
713         if (obj && yaffs_SkipVerification(obj->myDev))
714                 return;
715
716         /* Verify sane equivalent object */
717 }
718
719 static void yaffs_VerifySymlink(yaffs_Object *obj)
720 {
721         if (obj && yaffs_SkipVerification(obj->myDev))
722                 return;
723
724         /* Verify symlink string */
725 }
726
727 static void yaffs_VerifySpecial(yaffs_Object *obj)
728 {
729         if (obj && yaffs_SkipVerification(obj->myDev))
730                 return;
731 }
732
733 static void yaffs_VerifyObject(yaffs_Object *obj)
734 {
735         yaffs_Device *dev;
736
737         __u32 chunkMin;
738         __u32 chunkMax;
739
740         __u32 chunkIdOk;
741         __u32 chunkInRange;
742         __u32 chunkShouldNotBeDeleted;
743         __u32 chunkValid;
744
745         if (!obj)
746                 return;
747
748         if (obj->beingCreated)
749                 return;
750
751         dev = obj->myDev;
752
753         if (yaffs_SkipVerification(dev))
754                 return;
755
756         /* Check sane object header chunk */
757
758         chunkMin = dev->internalStartBlock * dev->nChunksPerBlock;
759         chunkMax = (dev->internalEndBlock+1) * dev->nChunksPerBlock - 1;
760
761         chunkInRange = (((unsigned)(obj->hdrChunk)) >= chunkMin && ((unsigned)(obj->hdrChunk)) <= chunkMax);
762         chunkIdOk = chunkInRange || (obj->hdrChunk == 0);
763         chunkValid = chunkInRange &&
764                         yaffs_CheckChunkBit(dev,
765                                         obj->hdrChunk / dev->nChunksPerBlock,
766                                         obj->hdrChunk % dev->nChunksPerBlock);
767         chunkShouldNotBeDeleted = chunkInRange && !chunkValid;
768
769         if (!obj->fake &&
770                         (!chunkIdOk || chunkShouldNotBeDeleted)) {
771                 T(YAFFS_TRACE_VERIFY,
772                         (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
773                         obj->objectId, obj->hdrChunk,
774                         chunkIdOk ? "" : ",out of range",
775                         chunkShouldNotBeDeleted ? ",marked as deleted" : ""));
776         }
777
778         if (chunkValid && !yaffs_SkipNANDVerification(dev)) {
779                 yaffs_ExtendedTags tags;
780                 yaffs_ObjectHeader *oh;
781                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
782
783                 oh = (yaffs_ObjectHeader *)buffer;
784
785                 yaffs_ReadChunkWithTagsFromNAND(dev, obj->hdrChunk, buffer,
786                                 &tags);
787
788                 yaffs_VerifyObjectHeader(obj, oh, &tags, 1);
789
790                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
791         }
792
793         /* Verify it has a parent */
794         if (obj && !obj->fake &&
795                         (!obj->parent || obj->parent->myDev != dev)) {
796                 T(YAFFS_TRACE_VERIFY,
797                         (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
798                         obj->objectId, obj->parent));
799         }
800
801         /* Verify parent is a directory */
802         if (obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
803                 T(YAFFS_TRACE_VERIFY,
804                         (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
805                         obj->objectId, obj->parent->variantType));
806         }
807
808         switch (obj->variantType) {
809         case YAFFS_OBJECT_TYPE_FILE:
810                 yaffs_VerifyFile(obj);
811                 break;
812         case YAFFS_OBJECT_TYPE_SYMLINK:
813                 yaffs_VerifySymlink(obj);
814                 break;
815         case YAFFS_OBJECT_TYPE_DIRECTORY:
816                 yaffs_VerifyDirectory(obj);
817                 break;
818         case YAFFS_OBJECT_TYPE_HARDLINK:
819                 yaffs_VerifyHardLink(obj);
820                 break;
821         case YAFFS_OBJECT_TYPE_SPECIAL:
822                 yaffs_VerifySpecial(obj);
823                 break;
824         case YAFFS_OBJECT_TYPE_UNKNOWN:
825         default:
826                 T(YAFFS_TRACE_VERIFY,
827                 (TSTR("Obj %d has illegaltype %d"TENDSTR),
828                 obj->objectId, obj->variantType));
829                 break;
830         }
831 }
832
833 static void yaffs_VerifyObjects(yaffs_Device *dev)
834 {
835         yaffs_Object *obj;
836         int i;
837         struct ylist_head *lh;
838
839         if (yaffs_SkipVerification(dev))
840                 return;
841
842         /* Iterate through the objects in each hash entry */
843
844         for (i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++) {
845                 ylist_for_each(lh, &dev->objectBucket[i].list) {
846                         if (lh) {
847                                 obj = ylist_entry(lh, yaffs_Object, hashLink);
848                                 yaffs_VerifyObject(obj);
849                         }
850                 }
851         }
852 }
853
854
855 /*
856  *  Simple hash function. Needs to have a reasonable spread
857  */
858
859 static Y_INLINE int yaffs_HashFunction(int n)
860 {
861         n = abs(n);
862         return n % YAFFS_NOBJECT_BUCKETS;
863 }
864
865 /*
866  * Access functions to useful fake objects.
867  * Note that root might have a presence in NAND if permissions are set.
868  */
869
870 yaffs_Object *yaffs_Root(yaffs_Device *dev)
871 {
872         return dev->rootDir;
873 }
874
875 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev)
876 {
877         return dev->lostNFoundDir;
878 }
879
880
881 /*
882  *  Erased NAND checking functions
883  */
884
885 int yaffs_CheckFF(__u8 *buffer, int nBytes)
886 {
887         /* Horrible, slow implementation */
888         while (nBytes--) {
889                 if (*buffer != 0xFF)
890                         return 0;
891                 buffer++;
892         }
893         return 1;
894 }
895
896 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
897                                 int chunkInNAND)
898 {
899         int retval = YAFFS_OK;
900         __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
901         yaffs_ExtendedTags tags;
902         int result;
903
904         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
905
906         if (tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
907                 retval = YAFFS_FAIL;
908
909         if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
910                 T(YAFFS_TRACE_NANDACCESS,
911                   (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
912                 retval = YAFFS_FAIL;
913         }
914
915         yaffs_ReleaseTempBuffer(dev, data, __LINE__);
916
917         return retval;
918
919 }
920
921 static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
922                                         const __u8 *data,
923                                         yaffs_ExtendedTags *tags,
924                                         int useReserve)
925 {
926         int attempts = 0;
927         int writeOk = 0;
928         int chunk;
929
930         yaffs_InvalidateCheckpoint(dev);
931
932         do {
933                 yaffs_BlockInfo *bi = 0;
934                 int erasedOk = 0;
935
936                 chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
937                 if (chunk < 0) {
938                         /* no space */
939                         break;
940                 }
941
942                 /* First check this chunk is erased, if it needs
943                  * checking.  The checking policy (unless forced
944                  * always on) is as follows:
945                  *
946                  * Check the first page we try to write in a block.
947                  * If the check passes then we don't need to check any
948                  * more.        If the check fails, we check again...
949                  * If the block has been erased, we don't need to check.
950                  *
951                  * However, if the block has been prioritised for gc,
952                  * then we think there might be something odd about
953                  * this block and stop using it.
954                  *
955                  * Rationale: We should only ever see chunks that have
956                  * not been erased if there was a partially written
957                  * chunk due to power loss.  This checking policy should
958                  * catch that case with very few checks and thus save a
959                  * lot of checks that are most likely not needed.
960                  */
961                 if (bi->gcPrioritise) {
962                         yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
963                         /* try another chunk */
964                         continue;
965                 }
966
967                 /* let's give it a try */
968                 attempts++;
969
970 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
971                 bi->skipErasedCheck = 0;
972 #endif
973                 if (!bi->skipErasedCheck) {
974                         erasedOk = yaffs_CheckChunkErased(dev, chunk);
975                         if (erasedOk != YAFFS_OK) {
976                                 T(YAFFS_TRACE_ERROR,
977                                 (TSTR("**>> yaffs chunk %d was not erased"
978                                 TENDSTR), chunk));
979
980                                 /* try another chunk */
981                                 continue;
982                         }
983                         bi->skipErasedCheck = 1;
984                 }
985
986                 writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
987                                 data, tags);
988                 if (writeOk != YAFFS_OK) {
989                         yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
990                         /* try another chunk */
991                         continue;
992                 }
993
994                 /* Copy the data into the robustification buffer */
995                 yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
996
997         } while (writeOk != YAFFS_OK &&
998                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
999
1000         if (!writeOk)
1001                 chunk = -1;
1002
1003         if (attempts > 1) {
1004                 T(YAFFS_TRACE_ERROR,
1005                         (TSTR("**>> yaffs write required %d attempts" TENDSTR),
1006                         attempts));
1007
1008                 dev->nRetriedWrites += (attempts - 1);
1009         }
1010
1011         return chunk;
1012 }
1013
1014 /*
1015  * Block retiring for handling a broken block.
1016  */
1017
1018 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND)
1019 {
1020         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1021
1022         yaffs_InvalidateCheckpoint(dev);
1023
1024         if (yaffs_MarkBlockBad(dev, blockInNAND) != YAFFS_OK) {
1025                 if (yaffs_EraseBlockInNAND(dev, blockInNAND) != YAFFS_OK) {
1026                         T(YAFFS_TRACE_ALWAYS, (TSTR(
1027                                 "yaffs: Failed to mark bad and erase block %d"
1028                                 TENDSTR), blockInNAND));
1029                 } else {
1030                         yaffs_ExtendedTags tags;
1031                         int chunkId = blockInNAND * dev->nChunksPerBlock;
1032
1033                         __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
1034
1035                         memset(buffer, 0xff, dev->nDataBytesPerChunk);
1036                         yaffs_InitialiseTags(&tags);
1037                         tags.sequenceNumber = YAFFS_SEQUENCE_BAD_BLOCK;
1038                         if (dev->writeChunkWithTagsToNAND(dev, chunkId -
1039                                 dev->chunkOffset, buffer, &tags) != YAFFS_OK)
1040                                 T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Failed to "
1041                                         TCONT("write bad block marker to block %d")
1042                                         TENDSTR), blockInNAND));
1043
1044                         yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
1045                 }
1046         }
1047
1048         bi->blockState = YAFFS_BLOCK_STATE_DEAD;
1049         bi->gcPrioritise = 0;
1050         bi->needsRetiring = 0;
1051
1052         dev->nRetiredBlocks++;
1053 }
1054
1055 /*
1056  * Functions for robustisizing TODO
1057  *
1058  */
1059
1060 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
1061                                 const __u8 *data,
1062                                 const yaffs_ExtendedTags *tags)
1063 {
1064 }
1065
1066 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
1067                                 const yaffs_ExtendedTags *tags)
1068 {
1069 }
1070
1071 void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
1072 {
1073         if (!bi->gcPrioritise) {
1074                 bi->gcPrioritise = 1;
1075                 dev->hasPendingPrioritisedGCs = 1;
1076                 bi->chunkErrorStrikes++;
1077
1078                 if (bi->chunkErrorStrikes > 3) {
1079                         bi->needsRetiring = 1; /* Too many stikes, so retire this */
1080                         T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));
1081
1082                 }
1083         }
1084 }
1085
1086 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
1087                 int erasedOk)
1088 {
1089         int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
1090         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
1091
1092         yaffs_HandleChunkError(dev, bi);
1093
1094         if (erasedOk) {
1095                 /* Was an actual write failure, so mark the block for retirement  */
1096                 bi->needsRetiring = 1;
1097                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
1098                   (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));
1099         }
1100
1101         /* Delete the chunk */
1102         yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
1103 }
1104
1105
1106 /*---------------- Name handling functions ------------*/
1107
1108 static __u16 yaffs_CalcNameSum(const YCHAR *name)
1109 {
1110         __u16 sum = 0;
1111         __u16 i = 1;
1112
1113         const YUCHAR *bname = (const YUCHAR *) name;
1114         if (bname) {
1115                 while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
1116
1117 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
1118                         sum += yaffs_toupper(*bname) * i;
1119 #else
1120                         sum += (*bname) * i;
1121 #endif
1122                         i++;
1123                         bname++;
1124                 }
1125         }
1126         return sum;
1127 }
1128
1129 static void yaffs_SetObjectName(yaffs_Object *obj, const YCHAR *name)
1130 {
1131 #ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
1132         memset(obj->shortName, 0, sizeof(YCHAR) * (YAFFS_SHORT_NAME_LENGTH+1));
1133         if (name && yaffs_strlen(name) <= YAFFS_SHORT_NAME_LENGTH)
1134                 yaffs_strcpy(obj->shortName, name);
1135         else
1136                 obj->shortName[0] = _Y('\0');
1137 #endif
1138         obj->sum = yaffs_CalcNameSum(name);
1139 }
1140
1141 /*-------------------- TNODES -------------------
1142
1143  * List of spare tnodes
1144  * The list is hooked together using the first pointer
1145  * in the tnode.
1146  */
1147
1148 /* yaffs_CreateTnodes creates a bunch more tnodes and
1149  * adds them to the tnode free list.
1150  * Don't use this function directly
1151  */
1152
1153 static int yaffs_CreateTnodes(yaffs_Device *dev, int nTnodes)
1154 {
1155         int i;
1156         int tnodeSize;
1157         yaffs_Tnode *newTnodes;
1158         __u8 *mem;
1159         yaffs_Tnode *curr;
1160         yaffs_Tnode *next;
1161         yaffs_TnodeList *tnl;
1162
1163         if (nTnodes < 1)
1164                 return YAFFS_OK;
1165
1166         /* Calculate the tnode size in bytes for variable width tnode support.
1167          * Must be a multiple of 32-bits  */
1168         tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
1169
1170         if (tnodeSize < sizeof(yaffs_Tnode))
1171                 tnodeSize = sizeof(yaffs_Tnode);
1172
1173         /* make these things */
1174
1175         newTnodes = YMALLOC(nTnodes * tnodeSize);
1176         mem = (__u8 *)newTnodes;
1177
1178         if (!newTnodes) {
1179                 T(YAFFS_TRACE_ERROR,
1180                         (TSTR("yaffs: Could not allocate Tnodes" TENDSTR)));
1181                 return YAFFS_FAIL;
1182         }
1183
1184         /* Hook them into the free list */
1185 #if 0
1186         for (i = 0; i < nTnodes - 1; i++) {
1187                 newTnodes[i].internal[0] = &newTnodes[i + 1];
1188 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1189                 newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1190 #endif
1191         }
1192
1193         newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
1194 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1195         newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1196 #endif
1197         dev->freeTnodes = newTnodes;
1198 #else
1199         /* New hookup for wide tnodes */
1200         for (i = 0; i < nTnodes - 1; i++) {
1201                 curr = (yaffs_Tnode *) &mem[i * tnodeSize];
1202                 next = (yaffs_Tnode *) &mem[(i+1) * tnodeSize];
1203                 curr->internal[0] = next;
1204         }
1205
1206         curr = (yaffs_Tnode *) &mem[(nTnodes - 1) * tnodeSize];
1207         curr->internal[0] = dev->freeTnodes;
1208         dev->freeTnodes = (yaffs_Tnode *)mem;
1209
1210 #endif
1211
1212
1213         dev->nFreeTnodes += nTnodes;
1214         dev->nTnodesCreated += nTnodes;
1215
1216         /* Now add this bunch of tnodes to a list for freeing up.
1217          * NB If we can't add this to the management list it isn't fatal
1218          * but it just means we can't free this bunch of tnodes later.
1219          */
1220
1221         tnl = YMALLOC(sizeof(yaffs_TnodeList));
1222         if (!tnl) {
1223                 T(YAFFS_TRACE_ERROR,
1224                   (TSTR
1225                    ("yaffs: Could not add tnodes to management list" TENDSTR)));
1226                    return YAFFS_FAIL;
1227         } else {
1228                 tnl->tnodes = newTnodes;
1229                 tnl->next = dev->allocatedTnodeList;
1230                 dev->allocatedTnodeList = tnl;
1231         }
1232
1233         T(YAFFS_TRACE_ALLOCATE, (TSTR("yaffs: Tnodes added" TENDSTR)));
1234
1235         return YAFFS_OK;
1236 }
1237
1238 /* GetTnode gets us a clean tnode. Tries to make allocate more if we run out */
1239
1240 static yaffs_Tnode *yaffs_GetTnodeRaw(yaffs_Device *dev)
1241 {
1242         yaffs_Tnode *tn = NULL;
1243
1244         /* If there are none left make more */
1245         if (!dev->freeTnodes)
1246                 yaffs_CreateTnodes(dev, YAFFS_ALLOCATION_NTNODES);
1247
1248         if (dev->freeTnodes) {
1249                 tn = dev->freeTnodes;
1250 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1251                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != (void *)1) {
1252                         /* Hoosterman, this thing looks like it isn't in the list */
1253                         T(YAFFS_TRACE_ALWAYS,
1254                           (TSTR("yaffs: Tnode list bug 1" TENDSTR)));
1255                 }
1256 #endif
1257                 dev->freeTnodes = dev->freeTnodes->internal[0];
1258                 dev->nFreeTnodes--;
1259         }
1260
1261         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1262
1263         return tn;
1264 }
1265
1266 static yaffs_Tnode *yaffs_GetTnode(yaffs_Device *dev)
1267 {
1268         yaffs_Tnode *tn = yaffs_GetTnodeRaw(dev);
1269         int tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
1270
1271         if (tnodeSize < sizeof(yaffs_Tnode))
1272                 tnodeSize = sizeof(yaffs_Tnode);
1273
1274         if (tn)
1275                 memset(tn, 0, tnodeSize);
1276
1277         return tn;
1278 }
1279
1280 /* FreeTnode frees up a tnode and puts it back on the free list */
1281 static void yaffs_FreeTnode(yaffs_Device *dev, yaffs_Tnode *tn)
1282 {
1283         if (tn) {
1284 #ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
1285                 if (tn->internal[YAFFS_NTNODES_INTERNAL] != 0) {
1286                         /* Hoosterman, this thing looks like it is already in the list */
1287                         T(YAFFS_TRACE_ALWAYS,
1288                           (TSTR("yaffs: Tnode list bug 2" TENDSTR)));
1289                 }
1290                 tn->internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
1291 #endif
1292                 tn->internal[0] = dev->freeTnodes;
1293                 dev->freeTnodes = tn;
1294                 dev->nFreeTnodes++;
1295         }
1296         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1297 }
1298
1299 static void yaffs_DeinitialiseTnodes(yaffs_Device *dev)
1300 {
1301         /* Free the list of allocated tnodes */
1302         yaffs_TnodeList *tmp;
1303
1304         while (dev->allocatedTnodeList) {
1305                 tmp = dev->allocatedTnodeList->next;
1306
1307                 YFREE(dev->allocatedTnodeList->tnodes);
1308                 YFREE(dev->allocatedTnodeList);
1309                 dev->allocatedTnodeList = tmp;
1310
1311         }
1312
1313         dev->freeTnodes = NULL;
1314         dev->nFreeTnodes = 0;
1315 }
1316
1317 static void yaffs_InitialiseTnodes(yaffs_Device *dev)
1318 {
1319         dev->allocatedTnodeList = NULL;
1320         dev->freeTnodes = NULL;
1321         dev->nFreeTnodes = 0;
1322         dev->nTnodesCreated = 0;
1323 }
1324
1325
1326 void yaffs_LoadLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos,
1327                 unsigned val)
1328 {
1329         __u32 *map = (__u32 *)tn;
1330         __u32 bitInMap;
1331         __u32 bitInWord;
1332         __u32 wordInMap;
1333         __u32 mask;
1334
1335         pos &= YAFFS_TNODES_LEVEL0_MASK;
1336         val >>= dev->chunkGroupBits;
1337
1338         bitInMap = pos * dev->tnodeWidth;
1339         wordInMap = bitInMap / 32;
1340         bitInWord = bitInMap & (32 - 1);
1341
1342         mask = dev->tnodeMask << bitInWord;
1343
1344         map[wordInMap] &= ~mask;
1345         map[wordInMap] |= (mask & (val << bitInWord));
1346
1347         if (dev->tnodeWidth > (32 - bitInWord)) {
1348                 bitInWord = (32 - bitInWord);
1349                 wordInMap++;;
1350                 mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
1351                 map[wordInMap] &= ~mask;
1352                 map[wordInMap] |= (mask & (val >> bitInWord));
1353         }
1354 }
1355
1356 static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn,
1357                 unsigned pos)
1358 {
1359         __u32 *map = (__u32 *)tn;
1360         __u32 bitInMap;
1361         __u32 bitInWord;
1362         __u32 wordInMap;
1363         __u32 val;
1364
1365         pos &= YAFFS_TNODES_LEVEL0_MASK;
1366
1367         bitInMap = pos * dev->tnodeWidth;
1368         wordInMap = bitInMap / 32;
1369         bitInWord = bitInMap & (32 - 1);
1370
1371         val = map[wordInMap] >> bitInWord;
1372
1373         if      (dev->tnodeWidth > (32 - bitInWord)) {
1374                 bitInWord = (32 - bitInWord);
1375                 wordInMap++;;
1376                 val |= (map[wordInMap] << bitInWord);
1377         }
1378
1379         val &= dev->tnodeMask;
1380         val <<= dev->chunkGroupBits;
1381
1382         return val;
1383 }
1384
1385 /* ------------------- End of individual tnode manipulation -----------------*/
1386
1387 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
1388  * The look up tree is represented by the top tnode and the number of topLevel
1389  * in the tree. 0 means only the level 0 tnode is in the tree.
1390  */
1391
1392 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
1393 static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,
1394                                         yaffs_FileStructure *fStruct,
1395                                         __u32 chunkId)
1396 {
1397         yaffs_Tnode *tn = fStruct->top;
1398         __u32 i;
1399         int requiredTallness;
1400         int level = fStruct->topLevel;
1401
1402         /* Check sane level and chunk Id */
1403         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
1404                 return NULL;
1405
1406         if (chunkId > YAFFS_MAX_CHUNK_ID)
1407                 return NULL;
1408
1409         /* First check we're tall enough (ie enough topLevel) */
1410
1411         i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1412         requiredTallness = 0;
1413         while (i) {
1414                 i >>= YAFFS_TNODES_INTERNAL_BITS;
1415                 requiredTallness++;
1416         }
1417
1418         if (requiredTallness > fStruct->topLevel)
1419                 return NULL; /* Not tall enough, so we can't find it */
1420
1421         /* Traverse down to level 0 */
1422         while (level > 0 && tn) {
1423                 tn = tn->internal[(chunkId >>
1424                         (YAFFS_TNODES_LEVEL0_BITS +
1425                                 (level - 1) *
1426                                 YAFFS_TNODES_INTERNAL_BITS)) &
1427                         YAFFS_TNODES_INTERNAL_MASK];
1428                 level--;
1429         }
1430
1431         return tn;
1432 }
1433
1434 /* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
1435  * This happens in two steps:
1436  *  1. If the tree isn't tall enough, then make it taller.
1437  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
1438  *
1439  * Used when modifying the tree.
1440  *
1441  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
1442  *  be plugged into the ttree.
1443  */
1444
1445 static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device *dev,
1446                                         yaffs_FileStructure *fStruct,
1447                                         __u32 chunkId,
1448                                         yaffs_Tnode *passedTn)
1449 {
1450         int requiredTallness;
1451         int i;
1452         int l;
1453         yaffs_Tnode *tn;
1454
1455         __u32 x;
1456
1457
1458         /* Check sane level and page Id */
1459         if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL)
1460                 return NULL;
1461
1462         if (chunkId > YAFFS_MAX_CHUNK_ID)
1463                 return NULL;
1464
1465         /* First check we're tall enough (ie enough topLevel) */
1466
1467         x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
1468         requiredTallness = 0;
1469         while (x) {
1470                 x >>= YAFFS_TNODES_INTERNAL_BITS;
1471                 requiredTallness++;
1472         }
1473
1474
1475         if (requiredTallness > fStruct->topLevel) {
1476                 /* Not tall enough, gotta make the tree taller */
1477                 for (i = fStruct->topLevel; i < requiredTallness; i++) {
1478
1479                         tn = yaffs_GetTnode(dev);
1480
1481                         if (tn) {
1482                                 tn->internal[0] = fStruct->top;
1483                                 fStruct->top = tn;
1484                                 fStruct->topLevel++;
1485                         } else {
1486                                 T(YAFFS_TRACE_ERROR,
1487                                         (TSTR("yaffs: no more tnodes" TENDSTR)));
1488                                 return NULL;
1489                         }
1490                 }
1491         }
1492
1493         /* Traverse down to level 0, adding anything we need */
1494
1495         l = fStruct->topLevel;
1496         tn = fStruct->top;
1497
1498         if (l > 0) {
1499                 while (l > 0 && tn) {
1500                         x = (chunkId >>
1501                              (YAFFS_TNODES_LEVEL0_BITS +
1502                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
1503                             YAFFS_TNODES_INTERNAL_MASK;
1504
1505
1506                         if ((l > 1) && !tn->internal[x]) {
1507                                 /* Add missing non-level-zero tnode */
1508                                 tn->internal[x] = yaffs_GetTnode(dev);
1509                                 if(!tn->internal[x])
1510                                         return NULL;
1511
1512                         } else if (l == 1) {
1513                                 /* Looking from level 1 at level 0 */
1514                                 if (passedTn) {
1515                                         /* If we already have one, then release it.*/
1516                                         if (tn->internal[x])
1517                                                 yaffs_FreeTnode(dev, tn->internal[x]);
1518                                         tn->internal[x] = passedTn;
1519
1520                                 } else if (!tn->internal[x]) {
1521                                         /* Don't have one, none passed in */
1522                                         tn->internal[x] = yaffs_GetTnode(dev);
1523                                         if(!tn->internal[x])
1524                                                 return NULL;
1525                                 }
1526                         }
1527
1528                         tn = tn->internal[x];
1529                         l--;
1530                 }
1531         } else {
1532                 /* top is level 0 */
1533                 if (passedTn) {
1534                         memcpy(tn, passedTn, (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
1535                         yaffs_FreeTnode(dev, passedTn);
1536                 }
1537         }
1538
1539         return tn;
1540 }
1541
1542 static int yaffs_FindChunkInGroup(yaffs_Device *dev, int theChunk,
1543                                 yaffs_ExtendedTags *tags, int objectId,
1544                                 int chunkInInode)
1545 {
1546         int j;
1547
1548         for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
1549                 if (yaffs_CheckChunkBit(dev, theChunk / dev->nChunksPerBlock,
1550                                 theChunk % dev->nChunksPerBlock)) {
1551                         
1552                         if(dev->chunkGroupSize == 1)
1553                                 return theChunk;
1554                         else {
1555                                 yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
1556                                                                 tags);
1557                                 if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
1558                                         /* found it; */
1559                                         return theChunk;
1560                                 }
1561                         }
1562                 }
1563                 theChunk++;
1564         }
1565         return -1;
1566 }
1567
1568
1569 /* DeleteWorker scans backwards through the tnode tree and deletes all the
1570  * chunks and tnodes in the file
1571  * Returns 1 if the tree was deleted.
1572  * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
1573  */
1574
1575 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
1576                               int chunkOffset, int *limit)
1577 {
1578         int i;
1579         int chunkInInode;
1580         int theChunk;
1581         yaffs_ExtendedTags tags;
1582         int foundChunk;
1583         yaffs_Device *dev = in->myDev;
1584
1585         int allDone = 1;
1586
1587         if (tn) {
1588                 if (level > 0) {
1589                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1590                              i--) {
1591                                 if (tn->internal[i]) {
1592                                         if (limit && (*limit) < 0) {
1593                                                 allDone = 0;
1594                                         } else {
1595                                                 allDone =
1596                                                         yaffs_DeleteWorker(in,
1597                                                                 tn->
1598                                                                 internal
1599                                                                 [i],
1600                                                                 level -
1601                                                                 1,
1602                                                                 (chunkOffset
1603                                                                         <<
1604                                                                         YAFFS_TNODES_INTERNAL_BITS)
1605                                                                 + i,
1606                                                                 limit);
1607                                         }
1608                                         if (allDone) {
1609                                                 yaffs_FreeTnode(dev,
1610                                                                 tn->
1611                                                                 internal[i]);
1612                                                 tn->internal[i] = NULL;
1613                                         }
1614                                 }
1615                         }
1616                         return (allDone) ? 1 : 0;
1617                 } else if (level == 0) {
1618                         int hitLimit = 0;
1619
1620                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
1621                                         i--) {
1622                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
1623                                 if (theChunk) {
1624
1625                                         chunkInInode = (chunkOffset <<
1626                                                 YAFFS_TNODES_LEVEL0_BITS) + i;
1627
1628                                         foundChunk =
1629                                                 yaffs_FindChunkInGroup(dev,
1630                                                                 theChunk,
1631                                                                 &tags,
1632                                                                 in->objectId,
1633                                                                 chunkInInode);
1634
1635                                         if (foundChunk > 0) {
1636                                                 yaffs_DeleteChunk(dev,
1637                                                                   foundChunk, 1,
1638                                                                   __LINE__);
1639                                                 in->nDataChunks--;
1640                                                 if (limit) {
1641                                                         *limit = *limit - 1;
1642                                                         if (*limit <= 0)
1643                                                                 hitLimit = 1;
1644                                                 }
1645
1646                                         }
1647
1648                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1649                                 }
1650
1651                         }
1652                         return (i < 0) ? 1 : 0;
1653
1654                 }
1655
1656         }
1657
1658         return 1;
1659
1660 }
1661
1662 static void yaffs_SoftDeleteChunk(yaffs_Device *dev, int chunk)
1663 {
1664         yaffs_BlockInfo *theBlock;
1665
1666         T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
1667
1668         theBlock = yaffs_GetBlockInfo(dev, chunk / dev->nChunksPerBlock);
1669         if (theBlock) {
1670                 theBlock->softDeletions++;
1671                 dev->nFreeChunks++;
1672         }
1673 }
1674
1675 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1676  * All soft deleting does is increment the block's softdelete count and pulls the chunk out
1677  * of the tnode.
1678  * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1679  */
1680
1681 static int yaffs_SoftDeleteWorker(yaffs_Object *in, yaffs_Tnode *tn,
1682                                   __u32 level, int chunkOffset)
1683 {
1684         int i;
1685         int theChunk;
1686         int allDone = 1;
1687         yaffs_Device *dev = in->myDev;
1688
1689         if (tn) {
1690                 if (level > 0) {
1691
1692                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1693                              i--) {
1694                                 if (tn->internal[i]) {
1695                                         allDone =
1696                                             yaffs_SoftDeleteWorker(in,
1697                                                                    tn->
1698                                                                    internal[i],
1699                                                                    level - 1,
1700                                                                    (chunkOffset
1701                                                                     <<
1702                                                                     YAFFS_TNODES_INTERNAL_BITS)
1703                                                                    + i);
1704                                         if (allDone) {
1705                                                 yaffs_FreeTnode(dev,
1706                                                                 tn->
1707                                                                 internal[i]);
1708                                                 tn->internal[i] = NULL;
1709                                         } else {
1710                                                 /* Hoosterman... how could this happen? */
1711                                         }
1712                                 }
1713                         }
1714                         return (allDone) ? 1 : 0;
1715                 } else if (level == 0) {
1716
1717                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1718                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
1719                                 if (theChunk) {
1720                                         /* Note this does not find the real chunk, only the chunk group.
1721                                          * We make an assumption that a chunk group is not larger than
1722                                          * a block.
1723                                          */
1724                                         yaffs_SoftDeleteChunk(dev, theChunk);
1725                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1726                                 }
1727
1728                         }
1729                         return 1;
1730
1731                 }
1732
1733         }
1734
1735         return 1;
1736
1737 }
1738
1739 static void yaffs_SoftDeleteFile(yaffs_Object *obj)
1740 {
1741         if (obj->deleted &&
1742             obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
1743                 if (obj->nDataChunks <= 0) {
1744                         /* Empty file with no duplicate object headers, just delete it immediately */
1745                         yaffs_FreeTnode(obj->myDev,
1746                                         obj->variant.fileVariant.top);
1747                         obj->variant.fileVariant.top = NULL;
1748                         T(YAFFS_TRACE_TRACING,
1749                           (TSTR("yaffs: Deleting empty file %d" TENDSTR),
1750                            obj->objectId));
1751                         yaffs_DoGenericObjectDeletion(obj);
1752                 } else {
1753                         yaffs_SoftDeleteWorker(obj,
1754                                                obj->variant.fileVariant.top,
1755                                                obj->variant.fileVariant.
1756                                                topLevel, 0);
1757                         obj->softDeleted = 1;
1758                 }
1759         }
1760 }
1761
1762 /* Pruning removes any part of the file structure tree that is beyond the
1763  * bounds of the file (ie that does not point to chunks).
1764  *
1765  * A file should only get pruned when its size is reduced.
1766  *
1767  * Before pruning, the chunks must be pulled from the tree and the
1768  * level 0 tnode entries must be zeroed out.
1769  * Could also use this for file deletion, but that's probably better handled
1770  * by a special case.
1771  */
1772
1773 static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device *dev, yaffs_Tnode *tn,
1774                                 __u32 level, int del0)
1775 {
1776         int i;
1777         int hasData;
1778
1779         if (tn) {
1780                 hasData = 0;
1781
1782                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1783                         if (tn->internal[i] && level > 0) {
1784                                 tn->internal[i] =
1785                                     yaffs_PruneWorker(dev, tn->internal[i],
1786                                                       level - 1,
1787                                                       (i == 0) ? del0 : 1);
1788                         }
1789
1790                         if (tn->internal[i])
1791                                 hasData++;
1792                 }
1793
1794                 if (hasData == 0 && del0) {
1795                         /* Free and return NULL */
1796
1797                         yaffs_FreeTnode(dev, tn);
1798                         tn = NULL;
1799                 }
1800
1801         }
1802
1803         return tn;
1804
1805 }
1806
1807 static int yaffs_PruneFileStructure(yaffs_Device *dev,
1808                                 yaffs_FileStructure *fStruct)
1809 {
1810         int i;
1811         int hasData;
1812         int done = 0;
1813         yaffs_Tnode *tn;
1814
1815         if (fStruct->topLevel > 0) {
1816                 fStruct->top =
1817                     yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);
1818
1819                 /* Now we have a tree with all the non-zero branches NULL but the height
1820                  * is the same as it was.
1821                  * Let's see if we can trim internal tnodes to shorten the tree.
1822                  * We can do this if only the 0th element in the tnode is in use
1823                  * (ie all the non-zero are NULL)
1824                  */
1825
1826                 while (fStruct->topLevel && !done) {
1827                         tn = fStruct->top;
1828
1829                         hasData = 0;
1830                         for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1831                                 if (tn->internal[i])
1832                                         hasData++;
1833                         }
1834
1835                         if (!hasData) {
1836                                 fStruct->top = tn->internal[0];
1837                                 fStruct->topLevel--;
1838                                 yaffs_FreeTnode(dev, tn);
1839                         } else {
1840                                 done = 1;
1841                         }
1842                 }
1843         }
1844
1845         return YAFFS_OK;
1846 }
1847
1848 /*-------------------- End of File Structure functions.-------------------*/
1849
1850 /* yaffs_CreateFreeObjects creates a bunch more objects and
1851  * adds them to the object free list.
1852  */
1853 static int yaffs_CreateFreeObjects(yaffs_Device *dev, int nObjects)
1854 {
1855         int i;
1856         yaffs_Object *newObjects;
1857         yaffs_ObjectList *list;
1858
1859         if (nObjects < 1)
1860                 return YAFFS_OK;
1861
1862         /* make these things */
1863         newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
1864         list = YMALLOC(sizeof(yaffs_ObjectList));
1865
1866         if (!newObjects || !list) {
1867                 if (newObjects){
1868                         YFREE(newObjects);
1869                         newObjects = NULL;
1870                 }
1871                 if (list){
1872                         YFREE(list);
1873                         list = NULL;
1874                 }
1875                 T(YAFFS_TRACE_ALLOCATE,
1876                   (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
1877                 return YAFFS_FAIL;
1878         }
1879
1880         /* Hook them into the free list */
1881         for (i = 0; i < nObjects - 1; i++) {
1882                 newObjects[i].siblings.next =
1883                                 (struct ylist_head *)(&newObjects[i + 1]);
1884         }
1885
1886         newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
1887         dev->freeObjects = newObjects;
1888         dev->nFreeObjects += nObjects;
1889         dev->nObjectsCreated += nObjects;
1890
1891         /* Now add this bunch of Objects to a list for freeing up. */
1892
1893         list->objects = newObjects;
1894         list->next = dev->allocatedObjectList;
1895         dev->allocatedObjectList = list;
1896
1897         return YAFFS_OK;
1898 }
1899
1900
1901 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
1902 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
1903 {
1904         yaffs_Object *tn = NULL;
1905
1906 #ifdef VALGRIND_TEST
1907         tn = YMALLOC(sizeof(yaffs_Object));
1908 #else
1909         /* If there are none left make more */
1910         if (!dev->freeObjects)
1911                 yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
1912
1913         if (dev->freeObjects) {
1914                 tn = dev->freeObjects;
1915                 dev->freeObjects =
1916                         (yaffs_Object *) (dev->freeObjects->siblings.next);
1917                 dev->nFreeObjects--;
1918         }
1919 #endif
1920         if (tn) {
1921                 /* Now sweeten it up... */
1922
1923                 memset(tn, 0, sizeof(yaffs_Object));
1924                 tn->beingCreated = 1;
1925
1926                 tn->myDev = dev;
1927                 tn->hdrChunk = 0;
1928                 tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
1929                 YINIT_LIST_HEAD(&(tn->hardLinks));
1930                 YINIT_LIST_HEAD(&(tn->hashLink));
1931                 YINIT_LIST_HEAD(&tn->siblings);
1932
1933
1934                 /* Now make the directory sane */
1935                 if (dev->rootDir) {
1936                         tn->parent = dev->rootDir;
1937                         ylist_add(&(tn->siblings), &dev->rootDir->variant.directoryVariant.children);
1938                 }
1939
1940                 /* Add it to the lost and found directory.
1941                  * NB Can't put root or lostNFound in lostNFound so
1942                  * check if lostNFound exists first
1943                  */
1944                 if (dev->lostNFoundDir)
1945                         yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
1946
1947                 tn->beingCreated = 0;
1948         }
1949
1950         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1951
1952         return tn;
1953 }
1954
1955 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev, int number,
1956                                                __u32 mode)
1957 {
1958
1959         yaffs_Object *obj =
1960             yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1961         if (obj) {
1962                 obj->fake = 1;          /* it is fake so it might have no NAND presence... */
1963                 obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
1964                 obj->unlinkAllowed = 0; /* ... or unlink it */
1965                 obj->deleted = 0;
1966                 obj->unlinked = 0;
1967                 obj->yst_mode = mode;
1968                 obj->myDev = dev;
1969                 obj->hdrChunk = 0;      /* Not a valid chunk. */
1970         }
1971
1972         return obj;
1973
1974 }
1975
1976 static void yaffs_UnhashObject(yaffs_Object *tn)
1977 {
1978         int bucket;
1979         yaffs_Device *dev = tn->myDev;
1980
1981         /* If it is still linked into the bucket list, free from the list */
1982         if (!ylist_empty(&tn->hashLink)) {
1983                 ylist_del_init(&tn->hashLink);
1984                 bucket = yaffs_HashFunction(tn->objectId);
1985                 dev->objectBucket[bucket].count--;
1986         }
1987 }
1988
1989 /*  FreeObject frees up a Object and puts it back on the free list */
1990 static void yaffs_FreeObject(yaffs_Object *tn)
1991 {
1992         yaffs_Device *dev = tn->myDev;
1993
1994 #ifdef __KERNEL__
1995         T(YAFFS_TRACE_OS, (TSTR("FreeObject %p inode %p"TENDSTR), tn, tn->myInode));
1996 #endif
1997
1998         if (tn->parent)
1999                 YBUG();
2000         if (!ylist_empty(&tn->siblings))
2001                 YBUG();
2002
2003
2004 #ifdef __KERNEL__
2005         if (tn->myInode) {
2006                 /* We're still hooked up to a cached inode.
2007                  * Don't delete now, but mark for later deletion
2008                  */
2009                 tn->deferedFree = 1;
2010                 return;
2011         }
2012 #endif
2013
2014         yaffs_UnhashObject(tn);
2015
2016 #ifdef VALGRIND_TEST
2017         YFREE(tn);
2018         tn = NULL;
2019 #else
2020         /* Link into the free list. */
2021         tn->siblings.next = (struct ylist_head *)(dev->freeObjects);
2022         dev->freeObjects = tn;
2023         dev->nFreeObjects++;
2024 #endif
2025         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
2026 }
2027
2028 #ifdef __KERNEL__
2029
2030 void yaffs_HandleDeferedFree(yaffs_Object *obj)
2031 {
2032         if (obj->deferedFree)
2033                 yaffs_FreeObject(obj);
2034 }
2035
2036 #endif
2037
2038 static void yaffs_DeinitialiseObjects(yaffs_Device *dev)
2039 {
2040         /* Free the list of allocated Objects */
2041
2042         yaffs_ObjectList *tmp;
2043
2044         while (dev->allocatedObjectList) {
2045                 tmp = dev->allocatedObjectList->next;
2046                 YFREE(dev->allocatedObjectList->objects);
2047                 YFREE(dev->allocatedObjectList);
2048
2049                 dev->allocatedObjectList = tmp;
2050         }
2051
2052         dev->freeObjects = NULL;
2053         dev->nFreeObjects = 0;
2054 }
2055
2056 static void yaffs_InitialiseObjects(yaffs_Device *dev)
2057 {
2058         int i;
2059
2060         dev->allocatedObjectList = NULL;
2061         dev->freeObjects = NULL;
2062         dev->nFreeObjects = 0;
2063
2064         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2065                 YINIT_LIST_HEAD(&dev->objectBucket[i].list);
2066                 dev->objectBucket[i].count = 0;
2067         }
2068 }
2069
2070 static int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
2071 {
2072         static int x;
2073         int i;
2074         int l = 999;
2075         int lowest = 999999;
2076
2077         /* First let's see if we can find one that's empty. */
2078
2079         for (i = 0; i < 10 && lowest > 0; i++) {
2080                 x++;
2081                 x %= YAFFS_NOBJECT_BUCKETS;
2082                 if (dev->objectBucket[x].count < lowest) {
2083                         lowest = dev->objectBucket[x].count;
2084                         l = x;
2085                 }
2086
2087         }
2088
2089         /* If we didn't find an empty list, then try
2090          * looking a bit further for a short one
2091          */
2092
2093         for (i = 0; i < 10 && lowest > 3; i++) {
2094                 x++;
2095                 x %= YAFFS_NOBJECT_BUCKETS;
2096                 if (dev->objectBucket[x].count < lowest) {
2097                         lowest = dev->objectBucket[x].count;
2098                         l = x;
2099                 }
2100
2101         }
2102
2103         return l;
2104 }
2105
2106 static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
2107 {
2108         int bucket = yaffs_FindNiceObjectBucket(dev);
2109
2110         /* Now find an object value that has not already been taken
2111          * by scanning the list.
2112          */
2113
2114         int found = 0;
2115         struct ylist_head *i;
2116
2117         __u32 n = (__u32) bucket;
2118
2119         /* yaffs_CheckObjectHashSanity();  */
2120
2121         while (!found) {
2122                 found = 1;
2123                 n += YAFFS_NOBJECT_BUCKETS;
2124                 if (1 || dev->objectBucket[bucket].count > 0) {
2125                         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2126                                 /* If there is already one in the list */
2127                                 if (i && ylist_entry(i, yaffs_Object,
2128                                                 hashLink)->objectId == n) {
2129                                         found = 0;
2130                                 }
2131                         }
2132                 }
2133         }
2134
2135         return n;
2136 }
2137
2138 static void yaffs_HashObject(yaffs_Object *in)
2139 {
2140         int bucket = yaffs_HashFunction(in->objectId);
2141         yaffs_Device *dev = in->myDev;
2142
2143         ylist_add(&in->hashLink, &dev->objectBucket[bucket].list);
2144         dev->objectBucket[bucket].count++;
2145 }
2146
2147 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev, __u32 number)
2148 {
2149         int bucket = yaffs_HashFunction(number);
2150         struct ylist_head *i;
2151         yaffs_Object *in;
2152
2153         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2154                 /* Look if it is in the list */
2155                 if (i) {
2156                         in = ylist_entry(i, yaffs_Object, hashLink);
2157                         if (in->objectId == number) {
2158 #ifdef __KERNEL__
2159                                 /* Don't tell the VFS about this one if it is defered free */
2160                                 if (in->deferedFree)
2161                                         return NULL;
2162 #endif
2163
2164                                 return in;
2165                         }
2166                 }
2167         }
2168
2169         return NULL;
2170 }
2171
2172 yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
2173                                     yaffs_ObjectType type)
2174 {
2175         yaffs_Object *theObject;
2176         yaffs_Tnode *tn = NULL;
2177
2178         if (number < 0)
2179                 number = yaffs_CreateNewObjectNumber(dev);
2180
2181         if (type == YAFFS_OBJECT_TYPE_FILE) {
2182                 tn = yaffs_GetTnode(dev);
2183                 if (!tn)
2184                         return NULL;
2185         }
2186
2187         theObject = yaffs_AllocateEmptyObject(dev);
2188         if (!theObject){
2189                 if(tn)
2190                         yaffs_FreeTnode(dev,tn);
2191                 return NULL;
2192         }
2193
2194
2195         if (theObject) {
2196                 theObject->fake = 0;
2197                 theObject->renameAllowed = 1;
2198                 theObject->unlinkAllowed = 1;
2199                 theObject->objectId = number;
2200                 yaffs_HashObject(theObject);
2201                 theObject->variantType = type;
2202 #ifdef CONFIG_YAFFS_WINCE
2203                 yfsd_WinFileTimeNow(theObject->win_atime);
2204                 theObject->win_ctime[0] = theObject->win_mtime[0] =
2205                     theObject->win_atime[0];
2206                 theObject->win_ctime[1] = theObject->win_mtime[1] =
2207                     theObject->win_atime[1];
2208
2209 #else
2210
2211                 theObject->yst_atime = theObject->yst_mtime =
2212                     theObject->yst_ctime = Y_CURRENT_TIME;
2213 #endif
2214                 switch (type) {
2215                 case YAFFS_OBJECT_TYPE_FILE:
2216                         theObject->variant.fileVariant.fileSize = 0;
2217                         theObject->variant.fileVariant.scannedFileSize = 0;
2218                         theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
2219                         theObject->variant.fileVariant.topLevel = 0;
2220                         theObject->variant.fileVariant.top = tn;
2221                         break;
2222                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2223                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
2224                                         children);
2225                         break;
2226                 case YAFFS_OBJECT_TYPE_SYMLINK:
2227                 case YAFFS_OBJECT_TYPE_HARDLINK:
2228                 case YAFFS_OBJECT_TYPE_SPECIAL:
2229                         /* No action required */
2230                         break;
2231                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2232                         /* todo this should not happen */
2233                         break;
2234                 }
2235         }
2236
2237         return theObject;
2238 }
2239
2240 static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev,
2241                                                       int number,
2242                                                       yaffs_ObjectType type)
2243 {
2244         yaffs_Object *theObject = NULL;
2245
2246         if (number > 0)
2247                 theObject = yaffs_FindObjectByNumber(dev, number);
2248
2249         if (!theObject)
2250                 theObject = yaffs_CreateNewObject(dev, number, type);
2251
2252         return theObject;
2253
2254 }
2255
2256
2257 static YCHAR *yaffs_CloneString(const YCHAR *str)
2258 {
2259         YCHAR *newStr = NULL;
2260
2261         if (!str)
2262                 str = _Y("");
2263
2264         newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
2265         if (newStr)
2266                 yaffs_strcpy(newStr, str);
2267
2268         return newStr;
2269
2270 }
2271
2272 /*
2273  * Mknod (create) a new object.
2274  * equivalentObject only has meaning for a hard link;
2275  * aliasString only has meaning for a symlink.
2276  * rdev only has meaning for devices (a subset of special objects)
2277  */
2278
2279 static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
2280                                        yaffs_Object *parent,
2281                                        const YCHAR *name,
2282                                        __u32 mode,
2283                                        __u32 uid,
2284                                        __u32 gid,
2285                                        yaffs_Object *equivalentObject,
2286                                        const YCHAR *aliasString, __u32 rdev)
2287 {
2288         yaffs_Object *in;
2289         YCHAR *str = NULL;
2290
2291         yaffs_Device *dev = parent->myDev;
2292
2293         /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
2294         if (yaffs_FindObjectByName(parent, name))
2295                 return NULL;
2296
2297         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2298                 str = yaffs_CloneString(aliasString);
2299                 if (!str)
2300                         return NULL;
2301         }
2302
2303         in = yaffs_CreateNewObject(dev, -1, type);
2304
2305         if (!in){
2306                 if(str)
2307                         YFREE(str);
2308                 return NULL;
2309         }
2310
2311
2312
2313
2314         if (in) {
2315                 in->hdrChunk = 0;
2316                 in->valid = 1;
2317                 in->variantType = type;
2318
2319                 in->yst_mode = mode;
2320
2321 #ifdef CONFIG_YAFFS_WINCE
2322                 yfsd_WinFileTimeNow(in->win_atime);
2323                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
2324                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
2325
2326 #else
2327                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
2328
2329                 in->yst_rdev = rdev;
2330                 in->yst_uid = uid;
2331                 in->yst_gid = gid;
2332 #endif
2333                 in->nDataChunks = 0;
2334
2335                 yaffs_SetObjectName(in, name);
2336                 in->dirty = 1;
2337
2338                 yaffs_AddObjectToDirectory(parent, in);
2339
2340                 in->myDev = parent->myDev;
2341
2342                 switch (type) {
2343                 case YAFFS_OBJECT_TYPE_SYMLINK:
2344                         in->variant.symLinkVariant.alias = str;
2345                         break;
2346                 case YAFFS_OBJECT_TYPE_HARDLINK:
2347                         in->variant.hardLinkVariant.equivalentObject =
2348                                 equivalentObject;
2349                         in->variant.hardLinkVariant.equivalentObjectId =
2350                                 equivalentObject->objectId;
2351                         ylist_add(&in->hardLinks, &equivalentObject->hardLinks);
2352                         break;
2353                 case YAFFS_OBJECT_TYPE_FILE:
2354                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2355                 case YAFFS_OBJECT_TYPE_SPECIAL:
2356                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2357                         /* do nothing */
2358                         break;
2359                 }
2360
2361                 if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
2362                         /* Could not create the object header, fail the creation */
2363                         yaffs_DeleteObject(in);
2364                         in = NULL;
2365                 }
2366
2367                 yaffs_UpdateParent(parent);
2368         }
2369
2370         return in;
2371 }
2372
2373 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent, const YCHAR *name,
2374                         __u32 mode, __u32 uid, __u32 gid)
2375 {
2376         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2377                                 uid, gid, NULL, NULL, 0);
2378 }
2379
2380 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent, const YCHAR *name,
2381                                 __u32 mode, __u32 uid, __u32 gid)
2382 {
2383         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2384                                  mode, uid, gid, NULL, NULL, 0);
2385 }
2386
2387 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent, const YCHAR *name,
2388                                 __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
2389 {
2390         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2391                                  uid, gid, NULL, NULL, rdev);
2392 }
2393
2394 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const YCHAR *name,
2395                                 __u32 mode, __u32 uid, __u32 gid,
2396                                 const YCHAR *alias)
2397 {
2398         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2399                                 uid, gid, NULL, alias, 0);
2400 }
2401
2402 /* yaffs_Link returns the object id of the equivalent object.*/
2403 yaffs_Object *yaffs_Link(yaffs_Object *parent, const YCHAR *name,
2404                         yaffs_Object *equivalentObject)
2405 {
2406         /* Get the real object in case we were fed a hard link as an equivalent object */
2407         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
2408
2409         if (yaffs_MknodObject
2410             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
2411              equivalentObject, NULL, 0)) {
2412                 return equivalentObject;
2413         } else {
2414                 return NULL;
2415         }
2416
2417 }
2418
2419 static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir,
2420                                 const YCHAR *newName, int force, int shadows)
2421 {
2422         int unlinkOp;
2423         int deleteOp;
2424
2425         yaffs_Object *existingTarget;
2426
2427         if (newDir == NULL)
2428                 newDir = obj->parent;   /* use the old directory */
2429
2430         if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
2431                 T(YAFFS_TRACE_ALWAYS,
2432                   (TSTR
2433                    ("tragedy: yaffs_ChangeObjectName: newDir is not a directory"
2434                     TENDSTR)));
2435                 YBUG();
2436         }
2437
2438         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
2439         if (obj->myDev->isYaffs2)
2440                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
2441         else
2442                 unlinkOp = (newDir == obj->myDev->unlinkedDir
2443                             && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
2444
2445         deleteOp = (newDir == obj->myDev->deletedDir);
2446
2447         existingTarget = yaffs_FindObjectByName(newDir, newName);
2448
2449         /* If the object is a file going into the unlinked directory,
2450          *   then it is OK to just stuff it in since duplicate names are allowed.
2451          *   else only proceed if the new name does not exist and if we're putting
2452          *   it into a directory.
2453          */
2454         if ((unlinkOp ||
2455              deleteOp ||
2456              force ||
2457              (shadows > 0) ||
2458              !existingTarget) &&
2459             newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
2460                 yaffs_SetObjectName(obj, newName);
2461                 obj->dirty = 1;
2462
2463                 yaffs_AddObjectToDirectory(newDir, obj);
2464
2465                 if (unlinkOp)
2466                         obj->unlinked = 1;
2467
2468                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
2469                 if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows) >= 0)
2470                         return YAFFS_OK;
2471         }
2472
2473         return YAFFS_FAIL;
2474 }
2475
2476 int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName,
2477                 yaffs_Object *newDir, const YCHAR *newName)
2478 {
2479         yaffs_Object *obj = NULL;
2480         yaffs_Object *existingTarget = NULL;
2481         int force = 0;
2482         int result;
2483         yaffs_Device *dev;
2484
2485
2486         if (!oldDir || oldDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2487                 YBUG();
2488         if (!newDir || newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2489                 YBUG();
2490
2491         dev = oldDir->myDev;
2492
2493 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
2494         /* Special case for case insemsitive systems (eg. WinCE).
2495          * While look-up is case insensitive, the name isn't.
2496          * Therefore we might want to change x.txt to X.txt
2497         */
2498         if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0)
2499                 force = 1;
2500 #endif
2501
2502         if(yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
2503                 /* ENAMETOOLONG */
2504                 return YAFFS_FAIL;
2505
2506         obj = yaffs_FindObjectByName(oldDir, oldName);
2507
2508         if (obj && obj->renameAllowed) {
2509
2510                 /* Now do the handling for an existing target, if there is one */
2511
2512                 existingTarget = yaffs_FindObjectByName(newDir, newName);
2513                 if (existingTarget &&
2514                         existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
2515                         !ylist_empty(&existingTarget->variant.directoryVariant.children)) {
2516                         /* There is a target that is a non-empty directory, so we fail */
2517                         return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
2518                 } else if (existingTarget && existingTarget != obj) {
2519                         /* Nuke the target first, using shadowing,
2520                          * but only if it isn't the same object.
2521                          *
2522                          * Note we must disable gc otherwise it can mess up the shadowing.
2523                          *
2524                          */
2525                         dev->isDoingGC=1;
2526                         yaffs_ChangeObjectName(obj, newDir, newName, force,
2527                                                 existingTarget->objectId);
2528                         existingTarget->isShadowed = 1;
2529                         yaffs_UnlinkObject(existingTarget);
2530                         dev->isDoingGC=0;
2531                 }
2532
2533                 result = yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
2534
2535                 yaffs_UpdateParent(oldDir);
2536                 if(newDir != oldDir)
2537                         yaffs_UpdateParent(newDir);
2538                 
2539                 return result;
2540         }
2541         return YAFFS_FAIL;
2542 }
2543
2544 /*------------------------- Block Management and Page Allocation ----------------*/
2545
2546 static int yaffs_InitialiseBlocks(yaffs_Device *dev)
2547 {
2548         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
2549
2550         dev->blockInfo = NULL;
2551         dev->chunkBits = NULL;
2552
2553         dev->allocationBlock = -1;      /* force it to get a new one */
2554
2555         /* If the first allocation strategy fails, thry the alternate one */
2556         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
2557         if (!dev->blockInfo) {
2558                 dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
2559                 dev->blockInfoAlt = 1;
2560         } else
2561                 dev->blockInfoAlt = 0;
2562
2563         if (dev->blockInfo) {
2564                 /* Set up dynamic blockinfo stuff. */
2565                 dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; /* round up bytes */
2566                 dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
2567                 if (!dev->chunkBits) {
2568                         dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
2569                         dev->chunkBitsAlt = 1;
2570                 } else
2571                         dev->chunkBitsAlt = 0;
2572         }
2573
2574         if (dev->blockInfo && dev->chunkBits) {
2575                 memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
2576                 memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
2577                 return YAFFS_OK;
2578         }
2579
2580         return YAFFS_FAIL;
2581 }
2582
2583 static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
2584 {
2585         if (dev->blockInfoAlt && dev->blockInfo)
2586                 YFREE_ALT(dev->blockInfo);
2587         else if (dev->blockInfo)
2588                 YFREE(dev->blockInfo);
2589
2590         dev->blockInfoAlt = 0;
2591
2592         dev->blockInfo = NULL;
2593
2594         if (dev->chunkBitsAlt && dev->chunkBits)
2595                 YFREE_ALT(dev->chunkBits);
2596         else if (dev->chunkBits)
2597                 YFREE(dev->chunkBits);
2598         dev->chunkBitsAlt = 0;
2599         dev->chunkBits = NULL;
2600 }
2601
2602 static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device *dev,
2603                                         yaffs_BlockInfo *bi)
2604 {
2605         int i;
2606         __u32 seq;
2607         yaffs_BlockInfo *b;
2608
2609         if (!dev->isYaffs2)
2610                 return 1;       /* disqualification only applies to yaffs2. */
2611
2612         if (!bi->hasShrinkHeader)
2613                 return 1;       /* can gc */
2614
2615         /* Find the oldest dirty sequence number if we don't know it and save it
2616          * so we don't have to keep recomputing it.
2617          */
2618         if (!dev->oldestDirtySequence) {
2619                 seq = dev->sequenceNumber;
2620
2621                 for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
2622                                 i++) {
2623                         b = yaffs_GetBlockInfo(dev, i);
2624                         if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
2625                             (b->pagesInUse - b->softDeletions) <
2626                             dev->nChunksPerBlock && b->sequenceNumber < seq) {
2627                                 seq = b->sequenceNumber;
2628                         }
2629                 }
2630                 dev->oldestDirtySequence = seq;
2631         }
2632
2633         /* Can't do gc of this block if there are any blocks older than this one that have
2634          * discarded pages.
2635          */
2636         return (bi->sequenceNumber <= dev->oldestDirtySequence);
2637 }
2638
2639 /* FindDiretiestBlock is used to select the dirtiest block (or close enough)
2640  * for garbage collection.
2641  */
2642
2643 static int yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
2644                                         int aggressive)
2645 {
2646         int b = dev->currentDirtyChecker;
2647
2648         int i;
2649         int iterations;
2650         int dirtiest = -1;
2651         int pagesInUse = 0;
2652         int prioritised = 0;
2653         yaffs_BlockInfo *bi;
2654         int pendingPrioritisedExist = 0;
2655
2656         /* First let's see if we need to grab a prioritised block */
2657         if (dev->hasPendingPrioritisedGCs) {
2658                 for (i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++) {
2659
2660                         bi = yaffs_GetBlockInfo(dev, i);
2661                         /* yaffs_VerifyBlock(dev,bi,i); */
2662
2663                         if (bi->gcPrioritise) {
2664                                 pendingPrioritisedExist = 1;
2665                                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2666                                    yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2667                                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2668                                         dirtiest = i;
2669                                         prioritised = 1;
2670                                         aggressive = 1; /* Fool the non-aggressive skip logiv below */
2671                                 }
2672                         }
2673                 }
2674
2675                 if (!pendingPrioritisedExist) /* None found, so we can clear this */
2676                         dev->hasPendingPrioritisedGCs = 0;
2677         }
2678
2679         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2680          * search harder.
2681          * else (we're doing a leasurely gc), then we only bother to do this if the
2682          * block has only a few pages in use.
2683          */
2684
2685         dev->nonAggressiveSkip--;
2686
2687         if (!aggressive && (dev->nonAggressiveSkip > 0))
2688                 return -1;
2689
2690         if (!prioritised)
2691                 pagesInUse =
2692                         (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
2693
2694         if (aggressive)
2695                 iterations =
2696                     dev->internalEndBlock - dev->internalStartBlock + 1;
2697         else {
2698                 iterations =
2699                     dev->internalEndBlock - dev->internalStartBlock + 1;
2700                 iterations = iterations / 16;
2701                 if (iterations > 200)
2702                         iterations = 200;
2703         }
2704
2705         for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
2706                 b++;
2707                 if (b < dev->internalStartBlock || b > dev->internalEndBlock)
2708                         b = dev->internalStartBlock;
2709
2710                 if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
2711                         T(YAFFS_TRACE_ERROR,
2712                           (TSTR("**>> Block %d is not valid" TENDSTR), b));
2713                         YBUG();
2714                 }
2715
2716                 bi = yaffs_GetBlockInfo(dev, b);
2717
2718                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2719                         (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
2720                                 yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2721                         dirtiest = b;
2722                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2723                 }
2724         }
2725
2726         dev->currentDirtyChecker = b;
2727
2728         if (dirtiest > 0) {
2729                 T(YAFFS_TRACE_GC,
2730                   (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
2731                    dev->nChunksPerBlock - pagesInUse, prioritised));
2732         }
2733
2734         dev->oldestDirtySequence = 0;
2735
2736         if (dirtiest > 0)
2737                 dev->nonAggressiveSkip = 4;
2738
2739         return dirtiest;
2740 }
2741
2742 static void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
2743 {
2744         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
2745
2746         int erasedOk = 0;
2747
2748         /* If the block is still healthy erase it and mark as clean.
2749          * If the block has had a data failure, then retire it.
2750          */
2751
2752         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2753                 (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
2754                 blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
2755
2756         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
2757
2758         if (!bi->needsRetiring) {
2759                 yaffs_InvalidateCheckpoint(dev);
2760                 erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
2761                 if (!erasedOk) {
2762                         dev->nErasureFailures++;
2763                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2764                           (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
2765                 }
2766         }
2767
2768         if (erasedOk &&
2769             ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
2770                 int i;
2771                 for (i = 0; i < dev->nChunksPerBlock; i++) {
2772                         if (!yaffs_CheckChunkErased
2773                             (dev, blockNo * dev->nChunksPerBlock + i)) {
2774                                 T(YAFFS_TRACE_ERROR,
2775                                   (TSTR
2776                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
2777                                     TENDSTR), blockNo, i));
2778                         }
2779                 }
2780         }
2781
2782         if (erasedOk) {
2783                 /* Clean it up... */
2784                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
2785                 dev->nErasedBlocks++;
2786                 bi->pagesInUse = 0;
2787                 bi->softDeletions = 0;
2788                 bi->hasShrinkHeader = 0;
2789                 bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
2790                 bi->gcPrioritise = 0;
2791                 yaffs_ClearChunkBits(dev, blockNo);
2792
2793                 T(YAFFS_TRACE_ERASE,
2794                   (TSTR("Erased block %d" TENDSTR), blockNo));
2795         } else {
2796                 dev->nFreeChunks -= dev->nChunksPerBlock;       /* We lost a block of free space */
2797
2798                 yaffs_RetireBlock(dev, blockNo);
2799                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2800                   (TSTR("**>> Block %d retired" TENDSTR), blockNo));
2801         }
2802 }
2803
2804 static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
2805 {
2806         int i;
2807
2808         yaffs_BlockInfo *bi;
2809
2810         if (dev->nErasedBlocks < 1) {
2811                 /* Hoosterman we've got a problem.
2812                  * Can't get space to gc
2813                  */
2814                 T(YAFFS_TRACE_ERROR,
2815                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
2816
2817                 return -1;
2818         }
2819
2820         /* Find an empty block. */
2821
2822         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
2823                 dev->allocationBlockFinder++;
2824                 if (dev->allocationBlockFinder < dev->internalStartBlock
2825                     || dev->allocationBlockFinder > dev->internalEndBlock) {
2826                         dev->allocationBlockFinder = dev->internalStartBlock;
2827                 }
2828
2829                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
2830
2831                 if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
2832                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
2833                         dev->sequenceNumber++;
2834                         bi->sequenceNumber = dev->sequenceNumber;
2835                         dev->nErasedBlocks--;
2836                         T(YAFFS_TRACE_ALLOCATE,
2837                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
2838                            dev->allocationBlockFinder, dev->sequenceNumber,
2839                            dev->nErasedBlocks));
2840                         return dev->allocationBlockFinder;
2841                 }
2842         }
2843
2844         T(YAFFS_TRACE_ALWAYS,
2845           (TSTR
2846            ("yaffs tragedy: no more erased blocks, but there should have been %d"
2847             TENDSTR), dev->nErasedBlocks));
2848
2849         return -1;
2850 }
2851
2852
2853
2854 static int yaffs_CalcCheckpointBlocksRequired(yaffs_Device *dev)
2855 {
2856         if (!dev->nCheckpointBlocksRequired &&
2857            dev->isYaffs2) {
2858                 /* Not a valid value so recalculate */
2859                 int nBytes = 0;
2860                 int nBlocks;
2861                 int devBlocks = (dev->endBlock - dev->startBlock + 1);
2862                 int tnodeSize;
2863
2864                 tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
2865
2866                 if (tnodeSize < sizeof(yaffs_Tnode))
2867                         tnodeSize = sizeof(yaffs_Tnode);
2868
2869                 nBytes += sizeof(yaffs_CheckpointValidity);
2870                 nBytes += sizeof(yaffs_CheckpointDevice);
2871                 nBytes += devBlocks * sizeof(yaffs_BlockInfo);
2872                 nBytes += devBlocks * dev->chunkBitmapStride;
2873                 nBytes += (sizeof(yaffs_CheckpointObject) + sizeof(__u32)) * (dev->nObjectsCreated - dev->nFreeObjects);
2874                 nBytes += (tnodeSize + sizeof(__u32)) * (dev->nTnodesCreated - dev->nFreeTnodes);
2875                 nBytes += sizeof(yaffs_CheckpointValidity);
2876                 nBytes += sizeof(__u32); /* checksum*/
2877
2878                 /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
2879
2880                 nBlocks = (nBytes/(dev->nDataBytesPerChunk * dev->nChunksPerBlock)) + 3;
2881
2882                 dev->nCheckpointBlocksRequired = nBlocks;
2883         }
2884
2885         return dev->nCheckpointBlocksRequired;
2886 }
2887
2888 /*
2889  * Check if there's space to allocate...
2890  * Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
2891  */
2892 static int yaffs_CheckSpaceForAllocation(yaffs_Device *dev)
2893 {
2894         int reservedChunks;
2895         int reservedBlocks = dev->nReservedBlocks;
2896         int checkpointBlocks;
2897
2898         if (dev->isYaffs2) {
2899                 checkpointBlocks =  yaffs_CalcCheckpointBlocksRequired(dev) -
2900                                     dev->blocksInCheckpoint;
2901                 if (checkpointBlocks < 0)
2902                         checkpointBlocks = 0;
2903         } else {
2904                 checkpointBlocks = 0;
2905         }
2906
2907         reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);
2908
2909         return (dev->nFreeChunks > reservedChunks);
2910 }
2911
2912 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
2913                 yaffs_BlockInfo **blockUsedPtr)
2914 {
2915         int retVal;
2916         yaffs_BlockInfo *bi;
2917
2918         if (dev->allocationBlock < 0) {
2919                 /* Get next block to allocate off */
2920                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
2921                 dev->allocationPage = 0;
2922         }
2923
2924         if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
2925                 /* Not enough space to allocate unless we're allowed to use the reserve. */
2926                 return -1;
2927         }
2928
2929         if (dev->nErasedBlocks < dev->nReservedBlocks
2930                         && dev->allocationPage == 0) {
2931                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
2932         }
2933
2934         /* Next page please.... */
2935         if (dev->allocationBlock >= 0) {
2936                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
2937
2938                 retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
2939                         dev->allocationPage;
2940                 bi->pagesInUse++;
2941                 yaffs_SetChunkBit(dev, dev->allocationBlock,
2942                                 dev->allocationPage);
2943
2944                 dev->allocationPage++;
2945
2946                 dev->nFreeChunks--;
2947
2948                 /* If the block is full set the state to full */
2949                 if (dev->allocationPage >= dev->nChunksPerBlock) {
2950                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2951                         dev->allocationBlock = -1;
2952                 }
2953
2954                 if (blockUsedPtr)
2955                         *blockUsedPtr = bi;
2956
2957                 return retVal;
2958         }
2959
2960         T(YAFFS_TRACE_ERROR,
2961                         (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
2962
2963         return -1;
2964 }
2965
2966 static int yaffs_GetErasedChunks(yaffs_Device *dev)
2967 {
2968         int n;
2969
2970         n = dev->nErasedBlocks * dev->nChunksPerBlock;
2971
2972         if (dev->allocationBlock > 0)
2973                 n += (dev->nChunksPerBlock - dev->allocationPage);
2974
2975         return n;
2976
2977 }
2978
2979 static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
2980                 int wholeBlock)
2981 {
2982         int oldChunk;
2983         int newChunk;
2984         int markNAND;
2985         int retVal = YAFFS_OK;
2986         int cleanups = 0;
2987         int i;
2988         int isCheckpointBlock;
2989         int matchingChunk;
2990         int maxCopies;
2991
2992         int chunksBefore = yaffs_GetErasedChunks(dev);
2993         int chunksAfter;
2994
2995         yaffs_ExtendedTags tags;
2996
2997         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
2998
2999         yaffs_Object *object;
3000
3001         isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
3002
3003
3004         T(YAFFS_TRACE_TRACING,
3005                         (TSTR("Collecting block %d, in use %d, shrink %d, wholeBlock %d" TENDSTR),
3006                          block,
3007                          bi->pagesInUse,
3008                          bi->hasShrinkHeader,
3009                          wholeBlock));
3010
3011         /*yaffs_VerifyFreeChunks(dev); */
3012
3013         if(bi->blockState == YAFFS_BLOCK_STATE_FULL)
3014                 bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
3015         
3016         bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
3017
3018         /* Take off the number of soft deleted entries because
3019          * they're going to get really deleted during GC.
3020          */
3021         if(dev->gcChunk == 0) /* first time through for this block */
3022                 dev->nFreeChunks -= bi->softDeletions;
3023
3024         dev->isDoingGC = 1;
3025
3026         if (isCheckpointBlock ||
3027                         !yaffs_StillSomeChunkBits(dev, block)) {
3028                 T(YAFFS_TRACE_TRACING,
3029                                 (TSTR
3030                                  ("Collecting block %d that has no chunks in use" TENDSTR),
3031                                  block));
3032                 yaffs_BlockBecameDirty(dev, block);
3033         } else {
3034
3035                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
3036
3037                 yaffs_VerifyBlock(dev, bi, block);
3038
3039                 maxCopies = (wholeBlock) ? dev->nChunksPerBlock : 10;
3040                 oldChunk = block * dev->nChunksPerBlock + dev->gcChunk;
3041
3042                 for (/* init already done */;
3043                      retVal == YAFFS_OK &&
3044                      dev->gcChunk < dev->nChunksPerBlock &&
3045                      (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) &&
3046                      maxCopies > 0;
3047                      dev->gcChunk++, oldChunk++) {
3048                         if (yaffs_CheckChunkBit(dev, block, dev->gcChunk)) {
3049
3050                                 /* This page is in use and might need to be copied off */
3051
3052                                 maxCopies--;
3053
3054                                 markNAND = 1;
3055
3056                                 yaffs_InitialiseTags(&tags);
3057
3058                                 yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
3059                                                                 buffer, &tags);
3060
3061                                 object =
3062                                     yaffs_FindObjectByNumber(dev,
3063                                                              tags.objectId);
3064
3065                                 T(YAFFS_TRACE_GC_DETAIL,
3066                                   (TSTR
3067                                    ("Collecting chunk in block %d, %d %d %d " TENDSTR),
3068                                    dev->gcChunk, tags.objectId, tags.chunkId,
3069                                    tags.byteCount));
3070
3071                                 if (object && !yaffs_SkipVerification(dev)) {
3072                                         if (tags.chunkId == 0)
3073                                                 matchingChunk = object->hdrChunk;
3074                                         else if (object->softDeleted)
3075                                                 matchingChunk = oldChunk; /* Defeat the test */
3076                                         else
3077                                                 matchingChunk = yaffs_FindChunkInFile(object, tags.chunkId, NULL);
3078
3079                                         if (oldChunk != matchingChunk)
3080                                                 T(YAFFS_TRACE_ERROR,
3081                                                   (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
3082                                                   oldChunk, matchingChunk, tags.objectId, tags.chunkId));
3083
3084                                 }
3085
3086                                 if (!object) {
3087                                         T(YAFFS_TRACE_ERROR,
3088                                           (TSTR
3089                                            ("page %d in gc has no object: %d %d %d "
3090                                             TENDSTR), oldChunk,
3091                                             tags.objectId, tags.chunkId, tags.byteCount));
3092                                 }
3093
3094                                 if (object &&
3095                                     object->deleted &&
3096                                     object->softDeleted &&
3097                                     tags.chunkId != 0) {
3098                                         /* Data chunk in a soft deleted file, throw it away
3099                                          * It's a soft deleted data chunk,
3100                                          * No need to copy this, just forget about it and
3101                                          * fix up the object.
3102                                          */
3103
3104                                         object->nDataChunks--;
3105
3106                                         if (object->nDataChunks <= 0) {
3107                                                 /* remeber to clean up the object */
3108                                                 dev->gcCleanupList[cleanups] =
3109                                                     tags.objectId;
3110                                                 cleanups++;
3111                                         }
3112                                         markNAND = 0;
3113                                 } else if (0) {
3114                                         /* Todo object && object->deleted && object->nDataChunks == 0 */
3115                                         /* Deleted object header with no data chunks.
3116                                          * Can be discarded and the file deleted.
3117                                          */
3118                                         object->hdrChunk = 0;
3119                                         yaffs_FreeTnode(object->myDev,
3120                                                         object->variant.
3121                                                         fileVariant.top);
3122                                         object->variant.fileVariant.top = NULL;
3123                                         yaffs_DoGenericObjectDeletion(object);
3124
3125                                 } else if (object) {
3126                                         /* It's either a data chunk in a live file or
3127                                          * an ObjectHeader, so we're interested in it.
3128                                          * NB Need to keep the ObjectHeaders of deleted files
3129                                          * until the whole file has been deleted off
3130                                          */
3131                                         tags.serialNumber++;
3132
3133                                         dev->nGCCopies++;
3134
3135                                         if (tags.chunkId == 0) {
3136                                                 /* It is an object Id,
3137                                                  * We need to nuke the shrinkheader flags first
3138                                                  * We no longer want the shrinkHeader flag since its work is done
3139                                                  * and if it is left in place it will mess up scanning.
3140                                                  */
3141
3142                                                 yaffs_ObjectHeader *oh;
3143                                                 oh = (yaffs_ObjectHeader *)buffer;
3144                                                 oh->isShrink = 0;
3145                                                 tags.extraIsShrinkHeader = 0;
3146
3147                                                 yaffs_VerifyObjectHeader(object, oh, &tags, 1);
3148                                         }
3149
3150                                         newChunk =
3151                                             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
3152
3153                                         if (newChunk < 0) {
3154                                                 retVal = YAFFS_FAIL;
3155                                         } else {
3156
3157                                                 /* Ok, now fix up the Tnodes etc. */
3158
3159                                                 if (tags.chunkId == 0) {
3160                                                         /* It's a header */
3161                                                         object->hdrChunk =  newChunk;
3162                                                         object->serial =   tags.serialNumber;
3163                                                 } else {
3164                                                         /* It's a data chunk */
3165                                                         yaffs_PutChunkIntoFile
3166                                                             (object,
3167                                                              tags.chunkId,
3168                                                              newChunk, 0);
3169                                                 }
3170                                         }
3171                                 }
3172
3173                                 if (retVal == YAFFS_OK)
3174                                         yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
3175
3176                         }
3177                 }
3178
3179                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3180
3181
3182                 /* Do any required cleanups */
3183                 for (i = 0; i < cleanups; i++) {
3184                         /* Time to delete the file too */
3185                         object =
3186                             yaffs_FindObjectByNumber(dev,
3187                                                      dev->gcCleanupList[i]);
3188                         if (object) {
3189                                 yaffs_FreeTnode(dev,
3190                                                 object->variant.fileVariant.
3191                                                 top);
3192                                 object->variant.fileVariant.top = NULL;
3193                                 T(YAFFS_TRACE_GC,
3194                                   (TSTR
3195                                    ("yaffs: About to finally delete object %d"
3196                                     TENDSTR), object->objectId));
3197                                 yaffs_DoGenericObjectDeletion(object);
3198                                 object->myDev->nDeletedFiles--;
3199                         }
3200
3201                 }
3202
3203         }
3204
3205         yaffs_VerifyCollectedBlock(dev, bi, block);
3206
3207         chunksAfter = yaffs_GetErasedChunks(dev);
3208         if (chunksBefore >= chunksAfter) {
3209                 T(YAFFS_TRACE_GC,
3210                   (TSTR
3211                    ("gc did not increase free chunks before %d after %d"
3212                     TENDSTR), chunksBefore, chunksAfter));
3213         }
3214
3215         /* If the gc completed then clear the current gcBlock so that we find another. */
3216         if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING) {
3217                 dev->gcBlock = -1;
3218                 dev->gcChunk = 0;
3219         }
3220
3221         dev->isDoingGC = 0;
3222
3223         return retVal;
3224 }
3225
3226 /* New garbage collector
3227  * If we're very low on erased blocks then we do aggressive garbage collection
3228  * otherwise we do "leasurely" garbage collection.
3229  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
3230  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
3231  *
3232  * The idea is to help clear out space in a more spread-out manner.
3233  * Dunno if it really does anything useful.
3234  */
3235 static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
3236 {
3237         int block;
3238         int aggressive;
3239         int gcOk = YAFFS_OK;
3240         int maxTries = 0;
3241
3242         int checkpointBlockAdjust;
3243
3244         if (dev->isDoingGC) {
3245                 /* Bail out so we don't get recursive gc */
3246                 return YAFFS_OK;
3247         }
3248
3249         /* This loop should pass the first time.
3250          * We'll only see looping here if the erase of the collected block fails.
3251          */
3252
3253         do {
3254                 maxTries++;
3255
3256                 checkpointBlockAdjust = yaffs_CalcCheckpointBlocksRequired(dev) - dev->blocksInCheckpoint;
3257                 if (checkpointBlockAdjust < 0)
3258                         checkpointBlockAdjust = 0;
3259
3260                 if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
3261                         /* We need a block soon...*/
3262                         aggressive = 1;
3263                 } else {
3264                         /* We're in no hurry */
3265                         aggressive = 0;
3266                 }
3267
3268                 if (dev->gcBlock <= 0) {
3269                         dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive);
3270                         dev->gcChunk = 0;
3271                 }
3272
3273                 block = dev->gcBlock;
3274
3275                 if (block > 0) {
3276                         dev->garbageCollections++;
3277                         if (!aggressive)
3278                                 dev->passiveGarbageCollections++;
3279
3280                         T(YAFFS_TRACE_GC,
3281                           (TSTR
3282                            ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
3283                            dev->nErasedBlocks, aggressive));
3284
3285                         gcOk = yaffs_GarbageCollectBlock(dev, block, aggressive);
3286                 }
3287
3288                 if (dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) {
3289                         T(YAFFS_TRACE_GC,
3290                           (TSTR
3291                            ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
3292                             TENDSTR), dev->nErasedBlocks, maxTries, block));
3293                 }
3294         } while ((dev->nErasedBlocks < dev->nReservedBlocks) &&
3295                  (block > 0) &&
3296                  (maxTries < 2));
3297
3298         return aggressive ? gcOk : YAFFS_OK;
3299 }
3300
3301 /*-------------------------  TAGS --------------------------------*/
3302
3303 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
3304                            int chunkInObject)
3305 {
3306         return (tags->chunkId == chunkInObject &&
3307                 tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
3308
3309 }
3310
3311
3312 /*-------------------- Data file manipulation -----------------*/
3313
3314 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
3315                                  yaffs_ExtendedTags *tags)
3316 {
3317         /*Get the Tnode, then get the level 0 offset chunk offset */
3318         yaffs_Tnode *tn;
3319         int theChunk = -1;
3320         yaffs_ExtendedTags localTags;
3321         int retVal = -1;
3322
3323         yaffs_Device *dev = in->myDev;
3324
3325         if (!tags) {
3326                 /* Passed a NULL, so use our own tags space */
3327                 tags = &localTags;
3328         }
3329
3330         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3331
3332         if (tn) {
3333                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3334
3335                 retVal =
3336                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3337                                            chunkInInode);
3338         }
3339         return retVal;
3340 }
3341
3342 static int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in, int chunkInInode,
3343                                           yaffs_ExtendedTags *tags)
3344 {
3345         /* Get the Tnode, then get the level 0 offset chunk offset */
3346         yaffs_Tnode *tn;
3347         int theChunk = -1;
3348         yaffs_ExtendedTags localTags;
3349
3350         yaffs_Device *dev = in->myDev;
3351         int retVal = -1;
3352
3353         if (!tags) {
3354                 /* Passed a NULL, so use our own tags space */
3355                 tags = &localTags;
3356         }
3357
3358         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3359
3360         if (tn) {