9517550b20f8f78c3c0163d64e054d60a518635c
[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 1.95 2009-11-11 01:40:41 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                 if (list)
1870                         YFREE(list);
1871                 T(YAFFS_TRACE_ALLOCATE,
1872                   (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
1873                 return YAFFS_FAIL;
1874         }
1875
1876         /* Hook them into the free list */
1877         for (i = 0; i < nObjects - 1; i++) {
1878                 newObjects[i].siblings.next =
1879                                 (struct ylist_head *)(&newObjects[i + 1]);
1880         }
1881
1882         newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
1883         dev->freeObjects = newObjects;
1884         dev->nFreeObjects += nObjects;
1885         dev->nObjectsCreated += nObjects;
1886
1887         /* Now add this bunch of Objects to a list for freeing up. */
1888
1889         list->objects = newObjects;
1890         list->next = dev->allocatedObjectList;
1891         dev->allocatedObjectList = list;
1892
1893         return YAFFS_OK;
1894 }
1895
1896
1897 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
1898 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
1899 {
1900         yaffs_Object *tn = NULL;
1901
1902 #ifdef VALGRIND_TEST
1903         tn = YMALLOC(sizeof(yaffs_Object));
1904 #else
1905         /* If there are none left make more */
1906         if (!dev->freeObjects)
1907                 yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
1908
1909         if (dev->freeObjects) {
1910                 tn = dev->freeObjects;
1911                 dev->freeObjects =
1912                         (yaffs_Object *) (dev->freeObjects->siblings.next);
1913                 dev->nFreeObjects--;
1914         }
1915 #endif
1916         if (tn) {
1917                 /* Now sweeten it up... */
1918
1919                 memset(tn, 0, sizeof(yaffs_Object));
1920                 tn->beingCreated = 1;
1921
1922                 tn->myDev = dev;
1923                 tn->hdrChunk = 0;
1924                 tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
1925                 YINIT_LIST_HEAD(&(tn->hardLinks));
1926                 YINIT_LIST_HEAD(&(tn->hashLink));
1927                 YINIT_LIST_HEAD(&tn->siblings);
1928
1929
1930                 /* Now make the directory sane */
1931                 if (dev->rootDir) {
1932                         tn->parent = dev->rootDir;
1933                         ylist_add(&(tn->siblings), &dev->rootDir->variant.directoryVariant.children);
1934                 }
1935
1936                 /* Add it to the lost and found directory.
1937                  * NB Can't put root or lostNFound in lostNFound so
1938                  * check if lostNFound exists first
1939                  */
1940                 if (dev->lostNFoundDir)
1941                         yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
1942
1943                 tn->beingCreated = 0;
1944         }
1945
1946         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1947
1948         return tn;
1949 }
1950
1951 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev, int number,
1952                                                __u32 mode)
1953 {
1954
1955         yaffs_Object *obj =
1956             yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1957         if (obj) {
1958                 obj->fake = 1;          /* it is fake so it might have no NAND presence... */
1959                 obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
1960                 obj->unlinkAllowed = 0; /* ... or unlink it */
1961                 obj->deleted = 0;
1962                 obj->unlinked = 0;
1963                 obj->yst_mode = mode;
1964                 obj->myDev = dev;
1965                 obj->hdrChunk = 0;      /* Not a valid chunk. */
1966         }
1967
1968         return obj;
1969
1970 }
1971
1972 static void yaffs_UnhashObject(yaffs_Object *tn)
1973 {
1974         int bucket;
1975         yaffs_Device *dev = tn->myDev;
1976
1977         /* If it is still linked into the bucket list, free from the list */
1978         if (!ylist_empty(&tn->hashLink)) {
1979                 ylist_del_init(&tn->hashLink);
1980                 bucket = yaffs_HashFunction(tn->objectId);
1981                 dev->objectBucket[bucket].count--;
1982         }
1983 }
1984
1985 /*  FreeObject frees up a Object and puts it back on the free list */
1986 static void yaffs_FreeObject(yaffs_Object *tn)
1987 {
1988         yaffs_Device *dev = tn->myDev;
1989
1990 #ifdef __KERNEL__
1991         T(YAFFS_TRACE_OS, (TSTR("FreeObject %p inode %p"TENDSTR), tn, tn->myInode));
1992 #endif
1993
1994         if (tn->parent)
1995                 YBUG();
1996         if (!ylist_empty(&tn->siblings))
1997                 YBUG();
1998
1999
2000 #ifdef __KERNEL__
2001         if (tn->myInode) {
2002                 /* We're still hooked up to a cached inode.
2003                  * Don't delete now, but mark for later deletion
2004                  */
2005                 tn->deferedFree = 1;
2006                 return;
2007         }
2008 #endif
2009
2010         yaffs_UnhashObject(tn);
2011
2012 #ifdef VALGRIND_TEST
2013         YFREE(tn);
2014 #else
2015         /* Link into the free list. */
2016         tn->siblings.next = (struct ylist_head *)(dev->freeObjects);
2017         dev->freeObjects = tn;
2018         dev->nFreeObjects++;
2019 #endif
2020         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
2021 }
2022
2023 #ifdef __KERNEL__
2024
2025 void yaffs_HandleDeferedFree(yaffs_Object *obj)
2026 {
2027         if (obj->deferedFree)
2028                 yaffs_FreeObject(obj);
2029 }
2030
2031 #endif
2032
2033 static void yaffs_DeinitialiseObjects(yaffs_Device *dev)
2034 {
2035         /* Free the list of allocated Objects */
2036
2037         yaffs_ObjectList *tmp;
2038
2039         while (dev->allocatedObjectList) {
2040                 tmp = dev->allocatedObjectList->next;
2041                 YFREE(dev->allocatedObjectList->objects);
2042                 YFREE(dev->allocatedObjectList);
2043
2044                 dev->allocatedObjectList = tmp;
2045         }
2046
2047         dev->freeObjects = NULL;
2048         dev->nFreeObjects = 0;
2049 }
2050
2051 static void yaffs_InitialiseObjects(yaffs_Device *dev)
2052 {
2053         int i;
2054
2055         dev->allocatedObjectList = NULL;
2056         dev->freeObjects = NULL;
2057         dev->nFreeObjects = 0;
2058
2059         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2060                 YINIT_LIST_HEAD(&dev->objectBucket[i].list);
2061                 dev->objectBucket[i].count = 0;
2062         }
2063 }
2064
2065 static int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
2066 {
2067         static int x;
2068         int i;
2069         int l = 999;
2070         int lowest = 999999;
2071
2072         /* First let's see if we can find one that's empty. */
2073
2074         for (i = 0; i < 10 && lowest > 0; i++) {
2075                 x++;
2076                 x %= YAFFS_NOBJECT_BUCKETS;
2077                 if (dev->objectBucket[x].count < lowest) {
2078                         lowest = dev->objectBucket[x].count;
2079                         l = x;
2080                 }
2081
2082         }
2083
2084         /* If we didn't find an empty list, then try
2085          * looking a bit further for a short one
2086          */
2087
2088         for (i = 0; i < 10 && lowest > 3; i++) {
2089                 x++;
2090                 x %= YAFFS_NOBJECT_BUCKETS;
2091                 if (dev->objectBucket[x].count < lowest) {
2092                         lowest = dev->objectBucket[x].count;
2093                         l = x;
2094                 }
2095
2096         }
2097
2098         return l;
2099 }
2100
2101 static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
2102 {
2103         int bucket = yaffs_FindNiceObjectBucket(dev);
2104
2105         /* Now find an object value that has not already been taken
2106          * by scanning the list.
2107          */
2108
2109         int found = 0;
2110         struct ylist_head *i;
2111
2112         __u32 n = (__u32) bucket;
2113
2114         /* yaffs_CheckObjectHashSanity();  */
2115
2116         while (!found) {
2117                 found = 1;
2118                 n += YAFFS_NOBJECT_BUCKETS;
2119                 if (1 || dev->objectBucket[bucket].count > 0) {
2120                         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2121                                 /* If there is already one in the list */
2122                                 if (i && ylist_entry(i, yaffs_Object,
2123                                                 hashLink)->objectId == n) {
2124                                         found = 0;
2125                                 }
2126                         }
2127                 }
2128         }
2129
2130         return n;
2131 }
2132
2133 static void yaffs_HashObject(yaffs_Object *in)
2134 {
2135         int bucket = yaffs_HashFunction(in->objectId);
2136         yaffs_Device *dev = in->myDev;
2137
2138         ylist_add(&in->hashLink, &dev->objectBucket[bucket].list);
2139         dev->objectBucket[bucket].count++;
2140 }
2141
2142 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev, __u32 number)
2143 {
2144         int bucket = yaffs_HashFunction(number);
2145         struct ylist_head *i;
2146         yaffs_Object *in;
2147
2148         ylist_for_each(i, &dev->objectBucket[bucket].list) {
2149                 /* Look if it is in the list */
2150                 if (i) {
2151                         in = ylist_entry(i, yaffs_Object, hashLink);
2152                         if (in->objectId == number) {
2153 #ifdef __KERNEL__
2154                                 /* Don't tell the VFS about this one if it is defered free */
2155                                 if (in->deferedFree)
2156                                         return NULL;
2157 #endif
2158
2159                                 return in;
2160                         }
2161                 }
2162         }
2163
2164         return NULL;
2165 }
2166
2167 yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
2168                                     yaffs_ObjectType type)
2169 {
2170         yaffs_Object *theObject;
2171         yaffs_Tnode *tn = NULL;
2172
2173         if (number < 0)
2174                 number = yaffs_CreateNewObjectNumber(dev);
2175
2176         if (type == YAFFS_OBJECT_TYPE_FILE) {
2177                 tn = yaffs_GetTnode(dev);
2178                 if (!tn)
2179                         return NULL;
2180         }
2181
2182         theObject = yaffs_AllocateEmptyObject(dev);
2183         if (!theObject){
2184                 if(tn)
2185                         yaffs_FreeTnode(dev,tn);
2186                 return NULL;
2187         }
2188
2189
2190         if (theObject) {
2191                 theObject->fake = 0;
2192                 theObject->renameAllowed = 1;
2193                 theObject->unlinkAllowed = 1;
2194                 theObject->objectId = number;
2195                 yaffs_HashObject(theObject);
2196                 theObject->variantType = type;
2197 #ifdef CONFIG_YAFFS_WINCE
2198                 yfsd_WinFileTimeNow(theObject->win_atime);
2199                 theObject->win_ctime[0] = theObject->win_mtime[0] =
2200                     theObject->win_atime[0];
2201                 theObject->win_ctime[1] = theObject->win_mtime[1] =
2202                     theObject->win_atime[1];
2203
2204 #else
2205
2206                 theObject->yst_atime = theObject->yst_mtime =
2207                     theObject->yst_ctime = Y_CURRENT_TIME;
2208 #endif
2209                 switch (type) {
2210                 case YAFFS_OBJECT_TYPE_FILE:
2211                         theObject->variant.fileVariant.fileSize = 0;
2212                         theObject->variant.fileVariant.scannedFileSize = 0;
2213                         theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
2214                         theObject->variant.fileVariant.topLevel = 0;
2215                         theObject->variant.fileVariant.top = tn;
2216                         break;
2217                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2218                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
2219                                         children);
2220                         break;
2221                 case YAFFS_OBJECT_TYPE_SYMLINK:
2222                 case YAFFS_OBJECT_TYPE_HARDLINK:
2223                 case YAFFS_OBJECT_TYPE_SPECIAL:
2224                         /* No action required */
2225                         break;
2226                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2227                         /* todo this should not happen */
2228                         break;
2229                 }
2230         }
2231
2232         return theObject;
2233 }
2234
2235 static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev,
2236                                                       int number,
2237                                                       yaffs_ObjectType type)
2238 {
2239         yaffs_Object *theObject = NULL;
2240
2241         if (number > 0)
2242                 theObject = yaffs_FindObjectByNumber(dev, number);
2243
2244         if (!theObject)
2245                 theObject = yaffs_CreateNewObject(dev, number, type);
2246
2247         return theObject;
2248
2249 }
2250
2251
2252 static YCHAR *yaffs_CloneString(const YCHAR *str)
2253 {
2254         YCHAR *newStr = NULL;
2255
2256         if (str && *str) {
2257                 newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
2258                 if (newStr)
2259                         yaffs_strcpy(newStr, str);
2260         }
2261
2262         return newStr;
2263
2264 }
2265
2266 /*
2267  * Mknod (create) a new object.
2268  * equivalentObject only has meaning for a hard link;
2269  * aliasString only has meaning for a sumlink.
2270  * rdev only has meaning for devices (a subset of special objects)
2271  */
2272
2273 static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
2274                                        yaffs_Object *parent,
2275                                        const YCHAR *name,
2276                                        __u32 mode,
2277                                        __u32 uid,
2278                                        __u32 gid,
2279                                        yaffs_Object *equivalentObject,
2280                                        const YCHAR *aliasString, __u32 rdev)
2281 {
2282         yaffs_Object *in;
2283         YCHAR *str = NULL;
2284
2285         yaffs_Device *dev = parent->myDev;
2286
2287         /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
2288         if (yaffs_FindObjectByName(parent, name))
2289                 return NULL;
2290
2291         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2292                 str = yaffs_CloneString(aliasString);
2293                 if (!str)
2294                         return NULL;
2295         }
2296
2297         in = yaffs_CreateNewObject(dev, -1, type);
2298
2299         if (!in){
2300                 if(str)
2301                         YFREE(str);
2302                 return NULL;
2303         }
2304
2305
2306
2307
2308         if (in) {
2309                 in->hdrChunk = 0;
2310                 in->valid = 1;
2311                 in->variantType = type;
2312
2313                 in->yst_mode = mode;
2314
2315 #ifdef CONFIG_YAFFS_WINCE
2316                 yfsd_WinFileTimeNow(in->win_atime);
2317                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
2318                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
2319
2320 #else
2321                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
2322
2323                 in->yst_rdev = rdev;
2324                 in->yst_uid = uid;
2325                 in->yst_gid = gid;
2326 #endif
2327                 in->nDataChunks = 0;
2328
2329                 yaffs_SetObjectName(in, name);
2330                 in->dirty = 1;
2331
2332                 yaffs_AddObjectToDirectory(parent, in);
2333
2334                 in->myDev = parent->myDev;
2335
2336                 switch (type) {
2337                 case YAFFS_OBJECT_TYPE_SYMLINK:
2338                         in->variant.symLinkVariant.alias = str;
2339                         break;
2340                 case YAFFS_OBJECT_TYPE_HARDLINK:
2341                         in->variant.hardLinkVariant.equivalentObject =
2342                                 equivalentObject;
2343                         in->variant.hardLinkVariant.equivalentObjectId =
2344                                 equivalentObject->objectId;
2345                         ylist_add(&in->hardLinks, &equivalentObject->hardLinks);
2346                         break;
2347                 case YAFFS_OBJECT_TYPE_FILE:
2348                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2349                 case YAFFS_OBJECT_TYPE_SPECIAL:
2350                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2351                         /* do nothing */
2352                         break;
2353                 }
2354
2355                 if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
2356                         /* Could not create the object header, fail the creation */
2357                         yaffs_DeleteObject(in);
2358                         in = NULL;
2359                 }
2360
2361                 yaffs_UpdateParent(parent);
2362         }
2363
2364         return in;
2365 }
2366
2367 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent, const YCHAR *name,
2368                         __u32 mode, __u32 uid, __u32 gid)
2369 {
2370         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2371                                 uid, gid, NULL, NULL, 0);
2372 }
2373
2374 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent, const YCHAR *name,
2375                                 __u32 mode, __u32 uid, __u32 gid)
2376 {
2377         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2378                                  mode, uid, gid, NULL, NULL, 0);
2379 }
2380
2381 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent, const YCHAR *name,
2382                                 __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
2383 {
2384         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2385                                  uid, gid, NULL, NULL, rdev);
2386 }
2387
2388 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const YCHAR *name,
2389                                 __u32 mode, __u32 uid, __u32 gid,
2390                                 const YCHAR *alias)
2391 {
2392         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2393                                 uid, gid, NULL, alias, 0);
2394 }
2395
2396 /* yaffs_Link returns the object id of the equivalent object.*/
2397 yaffs_Object *yaffs_Link(yaffs_Object *parent, const YCHAR *name,
2398                         yaffs_Object *equivalentObject)
2399 {
2400         /* Get the real object in case we were fed a hard link as an equivalent object */
2401         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
2402
2403         if (yaffs_MknodObject
2404             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
2405              equivalentObject, NULL, 0)) {
2406                 return equivalentObject;
2407         } else {
2408                 return NULL;
2409         }
2410
2411 }
2412
2413 static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir,
2414                                 const YCHAR *newName, int force, int shadows)
2415 {
2416         int unlinkOp;
2417         int deleteOp;
2418
2419         yaffs_Object *existingTarget;
2420
2421         if (newDir == NULL)
2422                 newDir = obj->parent;   /* use the old directory */
2423
2424         if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
2425                 T(YAFFS_TRACE_ALWAYS,
2426                   (TSTR
2427                    ("tragedy: yaffs_ChangeObjectName: newDir is not a directory"
2428                     TENDSTR)));
2429                 YBUG();
2430         }
2431
2432         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
2433         if (obj->myDev->isYaffs2)
2434                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
2435         else
2436                 unlinkOp = (newDir == obj->myDev->unlinkedDir
2437                             && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
2438
2439         deleteOp = (newDir == obj->myDev->deletedDir);
2440
2441         existingTarget = yaffs_FindObjectByName(newDir, newName);
2442
2443         /* If the object is a file going into the unlinked directory,
2444          *   then it is OK to just stuff it in since duplicate names are allowed.
2445          *   else only proceed if the new name does not exist and if we're putting
2446          *   it into a directory.
2447          */
2448         if ((unlinkOp ||
2449              deleteOp ||
2450              force ||
2451              (shadows > 0) ||
2452              !existingTarget) &&
2453             newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
2454                 yaffs_SetObjectName(obj, newName);
2455                 obj->dirty = 1;
2456
2457                 yaffs_AddObjectToDirectory(newDir, obj);
2458
2459                 if (unlinkOp)
2460                         obj->unlinked = 1;
2461
2462                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
2463                 if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows) >= 0)
2464                         return YAFFS_OK;
2465         }
2466
2467         return YAFFS_FAIL;
2468 }
2469
2470 int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName,
2471                 yaffs_Object *newDir, const YCHAR *newName)
2472 {
2473         yaffs_Object *obj = NULL;
2474         yaffs_Object *existingTarget = NULL;
2475         int force = 0;
2476         int result;
2477         yaffs_Device *dev;
2478
2479
2480         if (!oldDir || oldDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2481                 YBUG();
2482         if (!newDir || newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
2483                 YBUG();
2484
2485         dev = oldDir->myDev;
2486
2487 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
2488         /* Special case for case insemsitive systems (eg. WinCE).
2489          * While look-up is case insensitive, the name isn't.
2490          * Therefore we might want to change x.txt to X.txt
2491         */
2492         if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0)
2493                 force = 1;
2494 #endif
2495
2496         if(yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
2497                 /* ENAMETOOLONG */
2498                 return YAFFS_FAIL;
2499
2500         obj = yaffs_FindObjectByName(oldDir, oldName);
2501
2502         if (obj && obj->renameAllowed) {
2503
2504                 /* Now do the handling for an existing target, if there is one */
2505
2506                 existingTarget = yaffs_FindObjectByName(newDir, newName);
2507                 if (existingTarget &&
2508                         existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
2509                         !ylist_empty(&existingTarget->variant.directoryVariant.children)) {
2510                         /* There is a target that is a non-empty directory, so we fail */
2511                         return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
2512                 } else if (existingTarget && existingTarget != obj) {
2513                         /* Nuke the target first, using shadowing,
2514                          * but only if it isn't the same object.
2515                          *
2516                          * Note we must disable gc otherwise it can mess up the shadowing.
2517                          *
2518                          */
2519                         dev->isDoingGC=1;
2520                         yaffs_ChangeObjectName(obj, newDir, newName, force,
2521                                                 existingTarget->objectId);
2522                         existingTarget->isShadowed = 1;
2523                         yaffs_UnlinkObject(existingTarget);
2524                         dev->isDoingGC=0;
2525                 }
2526
2527                 result = yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
2528
2529                 yaffs_UpdateParent(oldDir);
2530                 if(newDir != oldDir)
2531                         yaffs_UpdateParent(newDir);
2532                 
2533                 return result;
2534         }
2535         return YAFFS_FAIL;
2536 }
2537
2538 /*------------------------- Block Management and Page Allocation ----------------*/
2539
2540 static int yaffs_InitialiseBlocks(yaffs_Device *dev)
2541 {
2542         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
2543
2544         dev->blockInfo = NULL;
2545         dev->chunkBits = NULL;
2546
2547         dev->allocationBlock = -1;      /* force it to get a new one */
2548
2549         /* If the first allocation strategy fails, thry the alternate one */
2550         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
2551         if (!dev->blockInfo) {
2552                 dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
2553                 dev->blockInfoAlt = 1;
2554         } else
2555                 dev->blockInfoAlt = 0;
2556
2557         if (dev->blockInfo) {
2558                 /* Set up dynamic blockinfo stuff. */
2559                 dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; /* round up bytes */
2560                 dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
2561                 if (!dev->chunkBits) {
2562                         dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
2563                         dev->chunkBitsAlt = 1;
2564                 } else
2565                         dev->chunkBitsAlt = 0;
2566         }
2567
2568         if (dev->blockInfo && dev->chunkBits) {
2569                 memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
2570                 memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
2571                 return YAFFS_OK;
2572         }
2573
2574         return YAFFS_FAIL;
2575 }
2576
2577 static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
2578 {
2579         if (dev->blockInfoAlt && dev->blockInfo)
2580                 YFREE_ALT(dev->blockInfo);
2581         else if (dev->blockInfo)
2582                 YFREE(dev->blockInfo);
2583
2584         dev->blockInfoAlt = 0;
2585
2586         dev->blockInfo = NULL;
2587
2588         if (dev->chunkBitsAlt && dev->chunkBits)
2589                 YFREE_ALT(dev->chunkBits);
2590         else if (dev->chunkBits)
2591                 YFREE(dev->chunkBits);
2592         dev->chunkBitsAlt = 0;
2593         dev->chunkBits = NULL;
2594 }
2595
2596 static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device *dev,
2597                                         yaffs_BlockInfo *bi)
2598 {
2599         int i;
2600         __u32 seq;
2601         yaffs_BlockInfo *b;
2602
2603         if (!dev->isYaffs2)
2604                 return 1;       /* disqualification only applies to yaffs2. */
2605
2606         if (!bi->hasShrinkHeader)
2607                 return 1;       /* can gc */
2608
2609         /* Find the oldest dirty sequence number if we don't know it and save it
2610          * so we don't have to keep recomputing it.
2611          */
2612         if (!dev->oldestDirtySequence) {
2613                 seq = dev->sequenceNumber;
2614
2615                 for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
2616                                 i++) {
2617                         b = yaffs_GetBlockInfo(dev, i);
2618                         if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
2619                             (b->pagesInUse - b->softDeletions) <
2620                             dev->nChunksPerBlock && b->sequenceNumber < seq) {
2621                                 seq = b->sequenceNumber;
2622                         }
2623                 }
2624                 dev->oldestDirtySequence = seq;
2625         }
2626
2627         /* Can't do gc of this block if there are any blocks older than this one that have
2628          * discarded pages.
2629          */
2630         return (bi->sequenceNumber <= dev->oldestDirtySequence);
2631 }
2632
2633 /* FindDiretiestBlock is used to select the dirtiest block (or close enough)
2634  * for garbage collection.
2635  */
2636
2637 static int yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
2638                                         int aggressive)
2639 {
2640         int b = dev->currentDirtyChecker;
2641
2642         int i;
2643         int iterations;
2644         int dirtiest = -1;
2645         int pagesInUse = 0;
2646         int prioritised = 0;
2647         yaffs_BlockInfo *bi;
2648         int pendingPrioritisedExist = 0;
2649
2650         /* First let's see if we need to grab a prioritised block */
2651         if (dev->hasPendingPrioritisedGCs) {
2652                 for (i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++) {
2653
2654                         bi = yaffs_GetBlockInfo(dev, i);
2655                         /* yaffs_VerifyBlock(dev,bi,i); */
2656
2657                         if (bi->gcPrioritise) {
2658                                 pendingPrioritisedExist = 1;
2659                                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2660                                    yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2661                                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2662                                         dirtiest = i;
2663                                         prioritised = 1;
2664                                         aggressive = 1; /* Fool the non-aggressive skip logiv below */
2665                                 }
2666                         }
2667                 }
2668
2669                 if (!pendingPrioritisedExist) /* None found, so we can clear this */
2670                         dev->hasPendingPrioritisedGCs = 0;
2671         }
2672
2673         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2674          * search harder.
2675          * else (we're doing a leasurely gc), then we only bother to do this if the
2676          * block has only a few pages in use.
2677          */
2678
2679         dev->nonAggressiveSkip--;
2680
2681         if (!aggressive && (dev->nonAggressiveSkip > 0))
2682                 return -1;
2683
2684         if (!prioritised)
2685                 pagesInUse =
2686                         (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
2687
2688         if (aggressive)
2689                 iterations =
2690                     dev->internalEndBlock - dev->internalStartBlock + 1;
2691         else {
2692                 iterations =
2693                     dev->internalEndBlock - dev->internalStartBlock + 1;
2694                 iterations = iterations / 16;
2695                 if (iterations > 200)
2696                         iterations = 200;
2697         }
2698
2699         for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
2700                 b++;
2701                 if (b < dev->internalStartBlock || b > dev->internalEndBlock)
2702                         b = dev->internalStartBlock;
2703
2704                 if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
2705                         T(YAFFS_TRACE_ERROR,
2706                           (TSTR("**>> Block %d is not valid" TENDSTR), b));
2707                         YBUG();
2708                 }
2709
2710                 bi = yaffs_GetBlockInfo(dev, b);
2711
2712                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2713                         (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
2714                                 yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
2715                         dirtiest = b;
2716                         pagesInUse = (bi->pagesInUse - bi->softDeletions);
2717                 }
2718         }
2719
2720         dev->currentDirtyChecker = b;
2721
2722         if (dirtiest > 0) {
2723                 T(YAFFS_TRACE_GC,
2724                   (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
2725                    dev->nChunksPerBlock - pagesInUse, prioritised));
2726         }
2727
2728         dev->oldestDirtySequence = 0;
2729
2730         if (dirtiest > 0)
2731                 dev->nonAggressiveSkip = 4;
2732
2733         return dirtiest;
2734 }
2735
2736 static void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
2737 {
2738         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
2739
2740         int erasedOk = 0;
2741
2742         /* If the block is still healthy erase it and mark as clean.
2743          * If the block has had a data failure, then retire it.
2744          */
2745
2746         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2747                 (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
2748                 blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
2749
2750         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
2751
2752         if (!bi->needsRetiring) {
2753                 yaffs_InvalidateCheckpoint(dev);
2754                 erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
2755                 if (!erasedOk) {
2756                         dev->nErasureFailures++;
2757                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2758                           (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
2759                 }
2760         }
2761
2762         if (erasedOk &&
2763             ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
2764                 int i;
2765                 for (i = 0; i < dev->nChunksPerBlock; i++) {
2766                         if (!yaffs_CheckChunkErased
2767                             (dev, blockNo * dev->nChunksPerBlock + i)) {
2768                                 T(YAFFS_TRACE_ERROR,
2769                                   (TSTR
2770                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
2771                                     TENDSTR), blockNo, i));
2772                         }
2773                 }
2774         }
2775
2776         if (erasedOk) {
2777                 /* Clean it up... */
2778                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
2779                 dev->nErasedBlocks++;
2780                 bi->pagesInUse = 0;
2781                 bi->softDeletions = 0;
2782                 bi->hasShrinkHeader = 0;
2783                 bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
2784                 bi->gcPrioritise = 0;
2785                 yaffs_ClearChunkBits(dev, blockNo);
2786
2787                 T(YAFFS_TRACE_ERASE,
2788                   (TSTR("Erased block %d" TENDSTR), blockNo));
2789         } else {
2790                 dev->nFreeChunks -= dev->nChunksPerBlock;       /* We lost a block of free space */
2791
2792                 yaffs_RetireBlock(dev, blockNo);
2793                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2794                   (TSTR("**>> Block %d retired" TENDSTR), blockNo));
2795         }
2796 }
2797
2798 static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
2799 {
2800         int i;
2801
2802         yaffs_BlockInfo *bi;
2803
2804         if (dev->nErasedBlocks < 1) {
2805                 /* Hoosterman we've got a problem.
2806                  * Can't get space to gc
2807                  */
2808                 T(YAFFS_TRACE_ERROR,
2809                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
2810
2811                 return -1;
2812         }
2813
2814         /* Find an empty block. */
2815
2816         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
2817                 dev->allocationBlockFinder++;
2818                 if (dev->allocationBlockFinder < dev->internalStartBlock
2819                     || dev->allocationBlockFinder > dev->internalEndBlock) {
2820                         dev->allocationBlockFinder = dev->internalStartBlock;
2821                 }
2822
2823                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
2824
2825                 if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
2826                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
2827                         dev->sequenceNumber++;
2828                         bi->sequenceNumber = dev->sequenceNumber;
2829                         dev->nErasedBlocks--;
2830                         T(YAFFS_TRACE_ALLOCATE,
2831                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
2832                            dev->allocationBlockFinder, dev->sequenceNumber,
2833                            dev->nErasedBlocks));
2834                         return dev->allocationBlockFinder;
2835                 }
2836         }
2837
2838         T(YAFFS_TRACE_ALWAYS,
2839           (TSTR
2840            ("yaffs tragedy: no more erased blocks, but there should have been %d"
2841             TENDSTR), dev->nErasedBlocks));
2842
2843         return -1;
2844 }
2845
2846
2847
2848 static int yaffs_CalcCheckpointBlocksRequired(yaffs_Device *dev)
2849 {
2850         if (!dev->nCheckpointBlocksRequired &&
2851            dev->isYaffs2) {
2852                 /* Not a valid value so recalculate */
2853                 int nBytes = 0;
2854                 int nBlocks;
2855                 int devBlocks = (dev->endBlock - dev->startBlock + 1);
2856                 int tnodeSize;
2857
2858                 tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
2859
2860                 if (tnodeSize < sizeof(yaffs_Tnode))
2861                         tnodeSize = sizeof(yaffs_Tnode);
2862
2863                 nBytes += sizeof(yaffs_CheckpointValidity);
2864                 nBytes += sizeof(yaffs_CheckpointDevice);
2865                 nBytes += devBlocks * sizeof(yaffs_BlockInfo);
2866                 nBytes += devBlocks * dev->chunkBitmapStride;
2867                 nBytes += (sizeof(yaffs_CheckpointObject) + sizeof(__u32)) * (dev->nObjectsCreated - dev->nFreeObjects);
2868                 nBytes += (tnodeSize + sizeof(__u32)) * (dev->nTnodesCreated - dev->nFreeTnodes);
2869                 nBytes += sizeof(yaffs_CheckpointValidity);
2870                 nBytes += sizeof(__u32); /* checksum*/
2871
2872                 /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
2873
2874                 nBlocks = (nBytes/(dev->nDataBytesPerChunk * dev->nChunksPerBlock)) + 3;
2875
2876                 dev->nCheckpointBlocksRequired = nBlocks;
2877         }
2878
2879         return dev->nCheckpointBlocksRequired;
2880 }
2881
2882 /*
2883  * Check if there's space to allocate...
2884  * Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
2885  */
2886 static int yaffs_CheckSpaceForAllocation(yaffs_Device *dev)
2887 {
2888         int reservedChunks;
2889         int reservedBlocks = dev->nReservedBlocks;
2890         int checkpointBlocks;
2891
2892         if (dev->isYaffs2) {
2893                 checkpointBlocks =  yaffs_CalcCheckpointBlocksRequired(dev) -
2894                                     dev->blocksInCheckpoint;
2895                 if (checkpointBlocks < 0)
2896                         checkpointBlocks = 0;
2897         } else {
2898                 checkpointBlocks = 0;
2899         }
2900
2901         reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);
2902
2903         return (dev->nFreeChunks > reservedChunks);
2904 }
2905
2906 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
2907                 yaffs_BlockInfo **blockUsedPtr)
2908 {
2909         int retVal;
2910         yaffs_BlockInfo *bi;
2911
2912         if (dev->allocationBlock < 0) {
2913                 /* Get next block to allocate off */
2914                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
2915                 dev->allocationPage = 0;
2916         }
2917
2918         if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
2919                 /* Not enough space to allocate unless we're allowed to use the reserve. */
2920                 return -1;
2921         }
2922
2923         if (dev->nErasedBlocks < dev->nReservedBlocks
2924                         && dev->allocationPage == 0) {
2925                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
2926         }
2927
2928         /* Next page please.... */
2929         if (dev->allocationBlock >= 0) {
2930                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
2931
2932                 retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
2933                         dev->allocationPage;
2934                 bi->pagesInUse++;
2935                 yaffs_SetChunkBit(dev, dev->allocationBlock,
2936                                 dev->allocationPage);
2937
2938                 dev->allocationPage++;
2939
2940                 dev->nFreeChunks--;
2941
2942                 /* If the block is full set the state to full */
2943                 if (dev->allocationPage >= dev->nChunksPerBlock) {
2944                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2945                         dev->allocationBlock = -1;
2946                 }
2947
2948                 if (blockUsedPtr)
2949                         *blockUsedPtr = bi;
2950
2951                 return retVal;
2952         }
2953
2954         T(YAFFS_TRACE_ERROR,
2955                         (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
2956
2957         return -1;
2958 }
2959
2960 static int yaffs_GetErasedChunks(yaffs_Device *dev)
2961 {
2962         int n;
2963
2964         n = dev->nErasedBlocks * dev->nChunksPerBlock;
2965
2966         if (dev->allocationBlock > 0)
2967                 n += (dev->nChunksPerBlock - dev->allocationPage);
2968
2969         return n;
2970
2971 }
2972
2973 static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
2974                 int wholeBlock)
2975 {
2976         int oldChunk;
2977         int newChunk;
2978         int markNAND;
2979         int retVal = YAFFS_OK;
2980         int cleanups = 0;
2981         int i;
2982         int isCheckpointBlock;
2983         int matchingChunk;
2984         int maxCopies;
2985
2986         int chunksBefore = yaffs_GetErasedChunks(dev);
2987         int chunksAfter;
2988
2989         yaffs_ExtendedTags tags;
2990
2991         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
2992
2993         yaffs_Object *object;
2994
2995         isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
2996
2997
2998         T(YAFFS_TRACE_TRACING,
2999                         (TSTR("Collecting block %d, in use %d, shrink %d, wholeBlock %d" TENDSTR),
3000                          block,
3001                          bi->pagesInUse,
3002                          bi->hasShrinkHeader,
3003                          wholeBlock));
3004
3005         /*yaffs_VerifyFreeChunks(dev); */
3006
3007         if(bi->blockState == YAFFS_BLOCK_STATE_FULL)
3008                 bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
3009         
3010         bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
3011
3012         /* Take off the number of soft deleted entries because
3013          * they're going to get really deleted during GC.
3014          */
3015         if(dev->gcChunk == 0) /* first time through for this block */
3016                 dev->nFreeChunks -= bi->softDeletions;
3017
3018         dev->isDoingGC = 1;
3019
3020         if (isCheckpointBlock ||
3021                         !yaffs_StillSomeChunkBits(dev, block)) {
3022                 T(YAFFS_TRACE_TRACING,
3023                                 (TSTR
3024                                  ("Collecting block %d that has no chunks in use" TENDSTR),
3025                                  block));
3026                 yaffs_BlockBecameDirty(dev, block);
3027         } else {
3028
3029                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
3030
3031                 yaffs_VerifyBlock(dev, bi, block);
3032
3033                 maxCopies = (wholeBlock) ? dev->nChunksPerBlock : 10;
3034                 oldChunk = block * dev->nChunksPerBlock + dev->gcChunk;
3035
3036                 for (/* init already done */;
3037                      retVal == YAFFS_OK &&
3038                      dev->gcChunk < dev->nChunksPerBlock &&
3039                      (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) &&
3040                      maxCopies > 0;
3041                      dev->gcChunk++, oldChunk++) {
3042                         if (yaffs_CheckChunkBit(dev, block, dev->gcChunk)) {
3043
3044                                 /* This page is in use and might need to be copied off */
3045
3046                                 maxCopies--;
3047
3048                                 markNAND = 1;
3049
3050                                 yaffs_InitialiseTags(&tags);
3051
3052                                 yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
3053                                                                 buffer, &tags);
3054
3055                                 object =
3056                                     yaffs_FindObjectByNumber(dev,
3057                                                              tags.objectId);
3058
3059                                 T(YAFFS_TRACE_GC_DETAIL,
3060                                   (TSTR
3061                                    ("Collecting chunk in block %d, %d %d %d " TENDSTR),
3062                                    dev->gcChunk, tags.objectId, tags.chunkId,
3063                                    tags.byteCount));
3064
3065                                 if (object && !yaffs_SkipVerification(dev)) {
3066                                         if (tags.chunkId == 0)
3067                                                 matchingChunk = object->hdrChunk;
3068                                         else if (object->softDeleted)
3069                                                 matchingChunk = oldChunk; /* Defeat the test */
3070                                         else
3071                                                 matchingChunk = yaffs_FindChunkInFile(object, tags.chunkId, NULL);
3072
3073                                         if (oldChunk != matchingChunk)
3074                                                 T(YAFFS_TRACE_ERROR,
3075                                                   (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
3076                                                   oldChunk, matchingChunk, tags.objectId, tags.chunkId));
3077
3078                                 }
3079
3080                                 if (!object) {
3081                                         T(YAFFS_TRACE_ERROR,
3082                                           (TSTR
3083                                            ("page %d in gc has no object: %d %d %d "
3084                                             TENDSTR), oldChunk,
3085                                             tags.objectId, tags.chunkId, tags.byteCount));
3086                                 }
3087
3088                                 if (object &&
3089                                     object->deleted &&
3090                                     object->softDeleted &&
3091                                     tags.chunkId != 0) {
3092                                         /* Data chunk in a soft deleted file, throw it away
3093                                          * It's a soft deleted data chunk,
3094                                          * No need to copy this, just forget about it and
3095                                          * fix up the object.
3096                                          */
3097
3098                                         object->nDataChunks--;
3099
3100                                         if (object->nDataChunks <= 0) {
3101                                                 /* remeber to clean up the object */
3102                                                 dev->gcCleanupList[cleanups] =
3103                                                     tags.objectId;
3104                                                 cleanups++;
3105                                         }
3106                                         markNAND = 0;
3107                                 } else if (0) {
3108                                         /* Todo object && object->deleted && object->nDataChunks == 0 */
3109                                         /* Deleted object header with no data chunks.
3110                                          * Can be discarded and the file deleted.
3111                                          */
3112                                         object->hdrChunk = 0;
3113                                         yaffs_FreeTnode(object->myDev,
3114                                                         object->variant.
3115                                                         fileVariant.top);
3116                                         object->variant.fileVariant.top = NULL;
3117                                         yaffs_DoGenericObjectDeletion(object);
3118
3119                                 } else if (object) {
3120                                         /* It's either a data chunk in a live file or
3121                                          * an ObjectHeader, so we're interested in it.
3122                                          * NB Need to keep the ObjectHeaders of deleted files
3123                                          * until the whole file has been deleted off
3124                                          */
3125                                         tags.serialNumber++;
3126
3127                                         dev->nGCCopies++;
3128
3129                                         if (tags.chunkId == 0) {
3130                                                 /* It is an object Id,
3131                                                  * We need to nuke the shrinkheader flags first
3132                                                  * We no longer want the shrinkHeader flag since its work is done
3133                                                  * and if it is left in place it will mess up scanning.
3134                                                  */
3135
3136                                                 yaffs_ObjectHeader *oh;
3137                                                 oh = (yaffs_ObjectHeader *)buffer;
3138                                                 oh->isShrink = 0;
3139                                                 tags.extraIsShrinkHeader = 0;
3140
3141                                                 yaffs_VerifyObjectHeader(object, oh, &tags, 1);
3142                                         }
3143
3144                                         newChunk =
3145                                             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
3146
3147                                         if (newChunk < 0) {
3148                                                 retVal = YAFFS_FAIL;
3149                                         } else {
3150
3151                                                 /* Ok, now fix up the Tnodes etc. */
3152
3153                                                 if (tags.chunkId == 0) {
3154                                                         /* It's a header */
3155                                                         object->hdrChunk =  newChunk;
3156                                                         object->serial =   tags.serialNumber;
3157                                                 } else {
3158                                                         /* It's a data chunk */
3159                                                         yaffs_PutChunkIntoFile
3160                                                             (object,
3161                                                              tags.chunkId,
3162                                                              newChunk, 0);
3163                                                 }
3164                                         }
3165                                 }
3166
3167                                 if (retVal == YAFFS_OK)
3168                                         yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
3169
3170                         }
3171                 }
3172
3173                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3174
3175
3176                 /* Do any required cleanups */
3177                 for (i = 0; i < cleanups; i++) {
3178                         /* Time to delete the file too */
3179                         object =
3180                             yaffs_FindObjectByNumber(dev,
3181                                                      dev->gcCleanupList[i]);
3182                         if (object) {
3183                                 yaffs_FreeTnode(dev,
3184                                                 object->variant.fileVariant.
3185                                                 top);
3186                                 object->variant.fileVariant.top = NULL;
3187                                 T(YAFFS_TRACE_GC,
3188                                   (TSTR
3189                                    ("yaffs: About to finally delete object %d"
3190                                     TENDSTR), object->objectId));
3191                                 yaffs_DoGenericObjectDeletion(object);
3192                                 object->myDev->nDeletedFiles--;
3193                         }
3194
3195                 }
3196
3197         }
3198
3199         yaffs_VerifyCollectedBlock(dev, bi, block);
3200
3201         chunksAfter = yaffs_GetErasedChunks(dev);
3202         if (chunksBefore >= chunksAfter) {
3203                 T(YAFFS_TRACE_GC,
3204                   (TSTR
3205                    ("gc did not increase free chunks before %d after %d"
3206                     TENDSTR), chunksBefore, chunksAfter));
3207         }
3208
3209         /* If the gc completed then clear the current gcBlock so that we find another. */
3210         if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING) {
3211                 dev->gcBlock = -1;
3212                 dev->gcChunk = 0;
3213         }
3214
3215         dev->isDoingGC = 0;
3216
3217         return retVal;
3218 }
3219
3220 /* New garbage collector
3221  * If we're very low on erased blocks then we do aggressive garbage collection
3222  * otherwise we do "leasurely" garbage collection.
3223  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
3224  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
3225  *
3226  * The idea is to help clear out space in a more spread-out manner.
3227  * Dunno if it really does anything useful.
3228  */
3229 static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
3230 {
3231         int block;
3232         int aggressive;
3233         int gcOk = YAFFS_OK;
3234         int maxTries = 0;
3235
3236         int checkpointBlockAdjust;
3237
3238         if (dev->isDoingGC) {
3239                 /* Bail out so we don't get recursive gc */
3240                 return YAFFS_OK;
3241         }
3242
3243         /* This loop should pass the first time.
3244          * We'll only see looping here if the erase of the collected block fails.
3245          */
3246
3247         do {
3248                 maxTries++;
3249
3250                 checkpointBlockAdjust = yaffs_CalcCheckpointBlocksRequired(dev) - dev->blocksInCheckpoint;
3251                 if (checkpointBlockAdjust < 0)
3252                         checkpointBlockAdjust = 0;
3253
3254                 if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
3255                         /* We need a block soon...*/
3256                         aggressive = 1;
3257                 } else {
3258                         /* We're in no hurry */
3259                         aggressive = 0;
3260                 }
3261
3262                 if (dev->gcBlock <= 0) {
3263                         dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive);
3264                         dev->gcChunk = 0;
3265                 }
3266
3267                 block = dev->gcBlock;
3268
3269                 if (block > 0) {
3270                         dev->garbageCollections++;
3271                         if (!aggressive)
3272                                 dev->passiveGarbageCollections++;
3273
3274                         T(YAFFS_TRACE_GC,
3275                           (TSTR
3276                            ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
3277                            dev->nErasedBlocks, aggressive));
3278
3279                         gcOk = yaffs_GarbageCollectBlock(dev, block, aggressive);
3280                 }
3281
3282                 if (dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) {
3283                         T(YAFFS_TRACE_GC,
3284                           (TSTR
3285                            ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
3286                             TENDSTR), dev->nErasedBlocks, maxTries, block));
3287                 }
3288         } while ((dev->nErasedBlocks < dev->nReservedBlocks) &&
3289                  (block > 0) &&
3290                  (maxTries < 2));
3291
3292         return aggressive ? gcOk : YAFFS_OK;
3293 }
3294
3295 /*-------------------------  TAGS --------------------------------*/
3296
3297 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
3298                            int chunkInObject)
3299 {
3300         return (tags->chunkId == chunkInObject &&
3301                 tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
3302
3303 }
3304
3305
3306 /*-------------------- Data file manipulation -----------------*/
3307
3308 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
3309                                  yaffs_ExtendedTags *tags)
3310 {
3311         /*Get the Tnode, then get the level 0 offset chunk offset */
3312         yaffs_Tnode *tn;
3313         int theChunk = -1;
3314         yaffs_ExtendedTags localTags;
3315         int retVal = -1;
3316
3317         yaffs_Device *dev = in->myDev;
3318
3319         if (!tags) {
3320                 /* Passed a NULL, so use our own tags space */
3321                 tags = &localTags;
3322         }
3323
3324         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3325
3326         if (tn) {
3327                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3328
3329                 retVal =
3330                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3331                                            chunkInInode);
3332         }
3333         return retVal;
3334 }
3335
3336 static int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in, int chunkInInode,
3337                                           yaffs_ExtendedTags *tags)
3338 {
3339         /* Get the Tnode, then get the level 0 offset chunk offset */
3340         yaffs_Tnode *tn;
3341         int theChunk = -1;
3342         yaffs_ExtendedTags localTags;
3343
3344         yaffs_Device *dev = in->myDev;
3345         int retVal = -1;
3346
3347         if (!tags) {
3348                 /* Passed a NULL, so use our own tags space */
3349                 tags = &localTags;
3350         }
3351
3352         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
3353
3354         if (tn) {
3355
3356                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3357
3358                 retVal =
3359                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
3360                                            chunkInInode);
3361
3362                 /* Delete the entry in the filestructure (if found) */
3363                 if (retVal != -1)
3364                         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, 0);
3365         }
3366
3367         return retVal;
3368 }
3369
3370 #ifdef YAFFS_PARANOID
3371
3372 static int yaffs_CheckFileSanity(yaffs_Object *in)
3373 {
3374         int chunk;
3375         int nChunks;
3376         int fSize;
3377         int failed = 0;
3378         int objId;
3379         yaffs_Tnode *tn;
3380         yaffs_Tags localTags;
3381         yaffs_Tags *tags = &localTags;
3382         int theChunk;
3383         int chunkDeleted;
3384
3385         if (in->variantType != YAFFS_OBJECT_TYPE_FILE)
3386                 return YAFFS_FAIL;
3387
3388         objId = in->objectId;
3389         fSize = in->variant.fileVariant.fileSize;
3390         nChunks =
3391             (fSize + in->myDev->nDataBytesPerChunk - 1) / in->myDev->nDataBytesPerChunk;
3392
3393         for (chunk = 1; chunk <= nChunks; chunk++) {
3394                 tn = yaffs_FindLevel0Tnode(in->myDev, &in->variant.fileVariant,
3395                                            chunk);
3396
3397                 if (tn) {
3398
3399                         theChunk = yaffs_GetChunkGroupBase(dev, tn, chunk);
3400
3401                         if (yaffs_CheckChunkBits
3402                             (dev, theChunk / dev->nChunksPerBlock,
3403                              theChunk % dev->nChunksPerBlock)) {
3404
3405                                 yaffs_ReadChunkTagsFromNAND(in->myDev, theChunk,
3406                                                             tags,
3407                                                             &chunkDeleted);
3408                                 if (yaffs_TagsMatch
3409                                     (tags, in->objectId, chunk, chunkDeleted)) {
3410                                         /* found it; */
3411
3412                                 }
3413                         } else {
3414
3415                                 failed = 1;
3416                         }
3417
3418                 } else {
3419                         /* T(("No level 0 found for %d\n", chunk)); */
3420                 }
3421         }
3422
3423         return failed ? YAFFS_FAIL : YAFFS_OK;
3424 }
3425
3426 #endif
3427
3428 static int yaffs_PutChunkIntoFile(yaffs_Object *in, int chunkInInode,
3429                                   int chunkInNAND, int inScan)
3430 {
3431         /* NB inScan is zero unless scanning.
3432          * For forward scanning, inScan is > 0;
3433          * for backward scanning inScan is < 0
3434          *
3435          * chunkInNAND = 0 is a dummy insert to make sure the tnodes are there.
3436          */
3437
3438         yaffs_Tnode *tn;
3439         yaffs_Device *dev = in->myDev;
3440         int existingChunk;
3441         yaffs_ExtendedTags existingTags;
3442         yaffs_ExtendedTags newTags;
3443         unsigned existingSerial, newSerial;
3444
3445         if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
3446                 /* Just ignore an attempt at putting a chunk into a non-file during scanning
3447                  * If it is not during Scanning then something went wrong!
3448                  */
3449                 if (!inScan) {
3450                         T(YAFFS_TRACE_ERROR,
3451                           (TSTR
3452                            ("yaffs tragedy:attempt to put data chunk into a non-file"
3453                             TENDSTR)));
3454                         YBUG();
3455                 }
3456
3457                 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
3458                 return YAFFS_OK;
3459         }
3460
3461         tn = yaffs_AddOrFindLevel0Tnode(dev,
3462                                         &in->variant.fileVariant,
3463                                         chunkInInode,
3464                                         NULL);
3465         if (!tn)
3466                 return YAFFS_FAIL;
3467         
3468         if(!chunkInNAND)
3469                 /* Dummy insert, bail now */
3470                 return YAFFS_OK;
3471                 
3472
3473         existingChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
3474
3475         if (inScan != 0) {
3476                 /* If we're scanning then we need to test for duplicates
3477                  * NB This does not need to be efficient since it should only ever
3478                  * happen when the power fails during a write, then only one
3479                  * chunk should ever be affected.
3480                  *
3481                  * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
3482                  * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
3483                  */
3484
3485                 if (existingChunk > 0) {
3486                         /* NB Right now existing chunk will not be real chunkId if the device >= 32MB
3487                          *    thus we have to do a FindChunkInFile to get the real chunk id.
3488                          *
3489                          * We have a duplicate now we need to decide which one to use:
3490                          *
3491                          * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
3492                          * Forward scanning YAFFS2: The new one is what we use, dump the old one.
3493                          * YAFFS1: Get both sets of tags and compare serial numbers.
3494                          */
3495
3496                         if (inScan > 0) {
3497                                 /* Only do this for forward scanning */
3498                                 yaffs_ReadChunkWithTagsFromNAND(dev,
3499                                                                 chunkInNAND,
3500                                                                 NULL, &newTags);
3501
3502                                 /* Do a proper find */
3503                                 existingChunk =
3504                                     yaffs_FindChunkInFile(in, chunkInInode,
3505                                                           &existingTags);
3506                         }
3507
3508                         if (existingChunk <= 0) {
3509                                 /*Hoosterman - how did this happen? */
3510
3511                                 T(YAFFS_TRACE_ERROR,
3512                                   (TSTR
3513                                    ("yaffs tragedy: existing chunk < 0 in scan"
3514                                     TENDSTR)));
3515
3516                         }
3517
3518                         /* NB The deleted flags should be false, otherwise the chunks will
3519                          * not be loaded during a scan
3520                          */
3521
3522                         if (inScan > 0) {
3523                                 newSerial = newTags.serialNumber;
3524                                 existingSerial = existingTags.serialNumber;
3525                         }
3526
3527                         if ((inScan > 0) &&
3528                             (in->myDev->isYaffs2 ||
3529                              existingChunk <= 0 ||
3530                              ((existingSerial + 1) & 3) == newSerial)) {
3531                                 /* Forward scanning.
3532                                  * Use new
3533                                  * Delete the old one and drop through to update the tnode
3534                                  */
3535                                 yaffs_DeleteChunk(dev, existingChunk, 1,
3536                                                   __LINE__);
3537                         } else {
3538                                 /* Backward scanning or we want to use the existing one
3539                                  * Use existing.
3540                                  * Delete the new one and return early so that the tnode isn't changed
3541                                  */
3542                                 yaffs_DeleteChunk(dev, chunkInNAND, 1,
3543                                                   __LINE__);
3544                                 return YAFFS_OK;
3545                         }
3546                 }
3547
3548         }
3549
3550         if (existingChunk == 0)
3551                 in->nDataChunks++;
3552
3553         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, chunkInNAND);
3554
3555         return YAFFS_OK;
3556 }
3557
3558 static int yaffs_ReadChunkDataFromObject(yaffs_Object *in, int chunkInInode,
3559                                         __u8 *buffer)
3560 {
3561         int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);
3562
3563         if (chunkInNAND >= 0)
3564                 return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
3565                                                 buffer, NULL);
3566         else {
3567                 T(YAFFS_TRACE_NANDACCESS,
3568                   (TSTR("Chunk %d not found zero instead" TENDSTR),
3569                    chunkInNAND));
3570                 /* get sane (zero) data if you read a hole */
3571                 memset(buffer, 0, in->myDev->nDataBytesPerChunk);
3572                 return 0;
3573         }
3574
3575 }
3576
3577 void yaffs_DeleteChunk(yaffs_Device *dev, int chunkId, int markNAND, int lyn)
3578 {
3579         int block;
3580         int page;
3581         yaffs_ExtendedTags tags;
3582         yaffs_BlockInfo *bi;
3583
3584         if (chunkId <= 0)
3585                 return;
3586
3587         dev->nDeletions++;
3588         block = chunkId / dev->nChunksPerBlock;
3589         page = chunkId % dev->nChunksPerBlock;
3590
3591
3592         if (!yaffs_CheckChunkBit(dev, block, page))
3593                 T(YAFFS_TRACE_VERIFY,
3594                         (TSTR("Deleting invalid chunk %d"TENDSTR),
3595                          chunkId));
3596
3597         bi = yaffs_GetBlockInfo(dev, block);
3598
3599         T(YAFFS_TRACE_DELETION,
3600           (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
3601
3602         if (markNAND &&
3603             bi->blockState != YAFFS_BLOCK_STATE_COLLECTING && !dev->isYaffs2) {
3604
3605                 yaffs_InitialiseTags(&tags);
3606
3607                 tags.chunkDeleted = 1;
3608
3609                 yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
3610                 yaffs_HandleUpdateChunk(dev, chunkId, &tags);
3611         } else {
3612                 dev->nUnmarkedDeletions++;
3613         }
3614
3615         /* Pull out of the management area.
3616          * If the whole block became dirty, this will kick off an erasure.
3617          */
3618         if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
3619             bi->blockState == YAFFS_BLOCK_STATE_FULL ||
3620             bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
3621             bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
3622                 dev->nFreeChunks++;
3623
3624                 yaffs_ClearChunkBit(dev, block, page);
3625
3626                 bi->pagesInUse--;
3627
3628                 if (bi->pagesInUse == 0 &&
3629                     !bi->hasShrinkHeader &&
3630                     bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
3631                     bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
3632                         yaffs_BlockBecameDirty(dev, block);
3633                 }
3634
3635         }
3636
3637 }
3638
3639 static int yaffs_WriteChunkDataToObject(yaffs_Object *in, int chunkInInode,
3640                                         const __u8 *buffer, int nBytes,
3641                                         int useReserve)
3642 {
3643         /* Find old chunk Need to do this to get serial number
3644          * Write new one and patch into tree.
3645          * Invalidate old tags.
3646          */
3647
3648         int prevChunkId;
3649         yaffs_ExtendedTags prevTags;
3650
3651         int newChunkId;
3652         yaffs_ExtendedTags newTags;
3653
3654         yaffs_Device *dev = in->myDev;
3655
3656         yaffs_CheckGarbageCollection(dev);
3657
3658         /* Get the previous chunk at this location in the file if it exists */
3659         prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);
3660
3661         /* Set up new tags */
3662         yaffs_InitialiseTags(&newTags);
3663
3664         newTags.chunkId = chunkInInode;
3665         newTags.objectId = in->objectId;
3666         newTags.serialNumber =
3667             (prevChunkId > 0) ? prevTags.serialNumber + 1 : 1;
3668         newTags.byteCount = nBytes;
3669
3670         if (nBytes < 1 || nBytes > dev->totalBytesPerChunk) {
3671                 T(YAFFS_TRACE_ERROR,
3672                 (TSTR("Writing %d bytes to chunk!!!!!!!!!" TENDSTR), nBytes));
3673                 YBUG();
3674         }
3675         
3676         /*
3677          * If there isn't already a chunk there then do a dummy
3678          * insert to make sue we have the desired tnode structure.
3679          */
3680         if(prevChunkId < 1 &&
3681                 yaffs_PutChunkIntoFile(in, chunkInInode, 0, 0) != YAFFS_OK)
3682                 return -1;
3683                 
3684         newChunkId =
3685             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3686                                               useReserve);
3687
3688         if (newChunkId > 0) {
3689                 yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);
3690
3691                 if (prevChunkId > 0)
3692                         yaffs_DeleteChunk(dev, prevChunkId, 1, __LINE__);
3693
3694                 yaffs_CheckFileSanity(in);
3695         }
3696         return newChunkId;
3697
3698 }
3699
3700 /* UpdateObjectHeader updates the header on NAND for an object.
3701  * If name is not NULL, then that new name is used.
3702  */
3703 int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
3704                              int isShrink, int shadows)
3705 {
3706
3707         yaffs_BlockInfo *bi;
3708
3709         yaffs_Device *dev = in->myDev;
3710
3711         int prevChunkId;
3712         int retVal = 0;
3713         int result = 0;
3714
3715         int newChunkId;
3716         yaffs_ExtendedTags newTags;
3717         yaffs_ExtendedTags oldTags;
3718
3719         __u8 *buffer = NULL;
3720         YCHAR oldName[YAFFS_MAX_NAME_LENGTH + 1];
3721
3722         yaffs_ObjectHeader *oh = NULL;
3723
3724         yaffs_strcpy(oldName, _Y("silly old name"));
3725
3726
3727         if (!in->fake ||
3728                 in == dev->rootDir || /* The rootDir should also be saved */
3729                 force) {
3730
3731                 yaffs_CheckGarbageCollection(dev);
3732                 yaffs_CheckObjectDetailsLoaded(in);
3733
3734                 buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
3735                 oh = (yaffs_ObjectHeader *) buffer;
3736
3737                 prevChunkId = in->hdrChunk;
3738
3739                 if (prevChunkId > 0) {
3740                         result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
3741                                                         buffer, &oldTags);
3742
3743                         yaffs_VerifyObjectHeader(in, oh, &oldTags, 0);
3744
3745                         memcpy(oldName, oh->name, sizeof(oh->name));
3746                 }
3747
3748                 memset(buffer, 0xFF, dev->nDataBytesPerChunk);
3749
3750                 oh->type = in->variantType;
3751                 oh->yst_mode = in->yst_mode;
3752                 oh->shadowsObject = oh->inbandShadowsObject = shadows;
3753
3754 #ifdef CONFIG_YAFFS_WINCE
3755                 oh->win_atime[0] = in->win_atime[0];
3756                 oh->win_ctime[0] = in->win_ctime[0];
3757                 oh->win_mtime[0] = in->win_mtime[0];
3758                 oh->win_atime[1] = in->win_atime[1];
3759                 oh->win_ctime[1] = in->win_ctime[1];
3760                 oh->win_mtime[1] = in->win_mtime[1];
3761 #else
3762                 oh->yst_uid = in->yst_uid;
3763                 oh->yst_gid = in->yst_gid;
3764                 oh->yst_atime = in->yst_atime;
3765                 oh->yst_mtime = in->yst_mtime;
3766                 oh->yst_ctime = in->yst_ctime;
3767                 oh->yst_rdev = in->yst_rdev;
3768 #endif
3769                 if (in->parent)
3770                         oh->parentObjectId = in->parent->objectId;
3771                 else
3772                         oh->parentObjectId = 0;
3773
3774                 if (name && *name) {
3775                         memset(oh->name, 0, sizeof(oh->name));
3776                         yaffs_strncpy(oh->name, name, YAFFS_MAX_NAME_LENGTH);
3777                 } else if (prevChunkId > 0)
3778                         memcpy(oh->name, oldName, sizeof(oh->name));
3779                 else
3780                         memset(oh->name, 0, sizeof(oh->name));
3781
3782                 oh->isShrink = isShrink;
3783
3784                 switch (in->variantType) {
3785                 case YAFFS_OBJECT_TYPE_UNKNOWN:
3786                         /* Should not happen */
3787                         break;
3788                 case YAFFS_OBJECT_TYPE_FILE:
3789                         oh->fileSize =
3790                             (oh->parentObjectId == YAFFS_OBJECTID_DELETED
3791                              || oh->parentObjectId ==
3792                              YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.
3793                             fileVariant.fileSize;
3794                         break;
3795                 case YAFFS_OBJECT_TYPE_HARDLINK:
3796                         oh->equivalentObjectId =
3797                             in->variant.hardLinkVariant.equivalentObjectId;
3798                         break;
3799                 case YAFFS_OBJECT_TYPE_SPECIAL:
3800                         /* Do nothing */
3801                         break;
3802                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3803                         /* Do nothing */
3804                         break;
3805                 case YAFFS_OBJECT_TYPE_SYMLINK:
3806                         yaffs_strncpy(oh->alias,
3807                                       in->variant.symLinkVariant.alias,
3808                                       YAFFS_MAX_ALIAS_LENGTH);
3809                         oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3810                         break;
3811                 }
3812
3813                 /* Tags */
3814                 yaffs_InitialiseTags(&newTags);
3815                 in->serial++;
3816                 newTags.chunkId = 0;
3817                 newTags.objectId = in->objectId;
3818                 newTags.serialNumber = in->serial;
3819
3820                 /* Add extra info for file header */
3821
3822                 newTags.extraHeaderInfoAvailable = 1;
3823                 newTags.extraParentObjectId = oh->parentObjectId;
3824                 newTags.extraFileLength = oh->fileSize;
3825                 newTags.extraIsShrinkHeader = oh->isShrink;
3826                 newTags.extraEquivalentObjectId = oh->equivalentObjectId;
3827                 newTags.extraShadows = (oh->shadowsObject > 0) ? 1 : 0;
3828                 newTags.extraObjectType = in->variantType;
3829
3830                 yaffs_VerifyObjectHeader(in, oh, &newTags, 1);
3831
3832                 /* Create new chunk in NAND */
3833                 newChunkId =
3834                     yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3835                                                       (prevChunkId > 0) ? 1 : 0);
3836
3837                 if (newChunkId >= 0) {
3838
3839                         in->hdrChunk = newChunkId;
3840
3841                         if (prevChunkId > 0) {
3842                                 yaffs_DeleteChunk(dev, prevChunkId, 1,
3843                                                   __LINE__);
3844                         }
3845
3846                         if (!yaffs_ObjectHasCachedWriteData(in))
3847                                 in->dirty = 0;
3848
3849                         /* If this was a shrink, then mark the block that the chunk lives on */
3850                         if (isShrink) {
3851                                 bi = yaffs_GetBlockInfo(in->myDev,
3852                                         newChunkId / in->myDev->nChunksPerBlock);
3853                                 bi->hasShrinkHeader = 1;
3854                         }
3855
3856                 }
3857
3858                 retVal = newChunkId;
3859
3860         }
3861
3862         if (buffer)
3863                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3864
3865         return retVal;
3866 }
3867
3868 /*------------------------ Short Operations Cache ----------------------------------------
3869  *   In many situations where there is no high level buffering (eg WinCE) a lot of
3870  *   reads might be short sequential reads, and a lot of writes may be short
3871  *   sequential writes. eg. scanning/writing a jpeg file.
3872  *   In these cases, a short read/write cache can provide a huge perfomance benefit
3873  *   with dumb-as-a-rock code.
3874  *   In Linux, the page cache provides read buffering aand the short op cache provides write
3875  *   buffering.
3876  *
3877  *   There are a limited number (~10) of cache chunks per device so that we don't
3878  *   need a very intelligent search.
3879  */
3880
3881 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj)
3882 {
3883         yaffs_Device *dev = obj->myDev;
3884         int i;
3885         yaffs_ChunkCache *cache;
3886         int nCaches = obj->myDev->nShortOpCaches;
3887
3888         for (i = 0; i < nCaches; i++) {
3889                 cache = &dev->srCache[i];
3890                 if (cache->object == obj &&
3891                     cache->dirty)
3892                         return 1;
3893         }
3894
3895         return 0;
3896 }
3897
3898