5db3da643403b6b9a9ad2aa4452ef1089cc73495
[yaffs2.git] / yaffs_guts.c
1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2010 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 #include "yportenv.h"
14 #include "yaffs_trace.h"
15
16 #include "yaffsinterface.h"
17 #include "yaffs_guts.h"
18 #include "yaffs_tagsvalidity.h"
19 #include "yaffs_getblockinfo.h"
20
21 #include "yaffs_tagscompat.h"
22
23 #include "yaffs_nand.h"
24
25 #include "yaffs_yaffs1.h"
26 #include "yaffs_yaffs2.h"
27 #include "yaffs_bitmap.h"
28 #include "yaffs_verify.h"
29
30 #include "yaffs_nand.h"
31 #include "yaffs_packedtags2.h"
32
33 #include "yaffs_nameval.h"
34 #include "yaffs_allocator.h"
35
36 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
37 #define YAFFS_GC_GOOD_ENOUGH 2
38 #define YAFFS_GC_PASSIVE_THRESHOLD 4
39
40 #include "yaffs_ecc.h"
41
42
43
44 /* Robustification (if it ever comes about...) */
45 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND);
46 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
47                 int erasedOk);
48 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
49                                 const __u8 *data,
50                                 const yaffs_ExtendedTags *tags);
51 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
52                                 const yaffs_ExtendedTags *tags);
53
54 /* Other local prototypes */
55 static void yaffs_UpdateParent(yaffs_Object *obj);
56 static int yaffs_UnlinkObject(yaffs_Object *obj);
57 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);
58
59 static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev,
60                                         const __u8 *buffer,
61                                         yaffs_ExtendedTags *tags,
62                                         int useReserve);
63
64
65 static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
66                                         yaffs_ObjectType type);
67
68
69 static int yaffs_ApplyXMod(yaffs_Object *obj, char *buffer, yaffs_XAttrMod *xmod);
70
71 static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
72 static int yaffs_CheckStructures(void);
73 static int yaffs_DoGenericObjectDeletion(yaffs_Object *in);
74
75 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
76                                 int chunkInNAND);
77
78 static int yaffs_UnlinkWorker(yaffs_Object *obj);
79
80 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
81                         int chunkInObject);
82
83 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
84                                 yaffs_BlockInfo **blockUsedPtr);
85
86 static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
87
88 static void yaffs_InvalidateWholeChunkCache(yaffs_Object *in);
89 static void yaffs_InvalidateChunkCache(yaffs_Object *object, int chunkId);
90
91 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
92                                 yaffs_ExtendedTags *tags);
93
94 static int yaffs_VerifyChunkWritten(yaffs_Device *dev,
95                                         int chunkInNAND,
96                                         const __u8 *data,
97                                         yaffs_ExtendedTags *tags);
98
99
100 static void yaffs_LoadNameFromObjectHeader(yaffs_Device *dev,YCHAR *name, const YCHAR *ohName, int bufferSize);
101 static void yaffs_LoadObjectHeaderFromName(yaffs_Device *dev,YCHAR *ohName, const YCHAR *name);
102
103
104 /* Function to calculate chunk and offset */
105
106 static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, int *chunkOut,
107                 __u32 *offsetOut)
108 {
109         int chunk;
110         __u32 offset;
111
112         chunk  = (__u32)(addr >> dev->chunkShift);
113
114         if (dev->chunkDiv == 1) {
115                 /* easy power of 2 case */
116                 offset = (__u32)(addr & dev->chunkMask);
117         } else {
118                 /* Non power-of-2 case */
119
120                 loff_t chunkBase;
121
122                 chunk /= dev->chunkDiv;
123
124                 chunkBase = ((loff_t)chunk) * dev->nDataBytesPerChunk;
125                 offset = (__u32)(addr - chunkBase);
126         }
127
128         *chunkOut = chunk;
129         *offsetOut = offset;
130 }
131
132 /* Function to return the number of shifts for a power of 2 greater than or
133  * equal to the given number
134  * Note we don't try to cater for all possible numbers and this does not have to
135  * be hellishly efficient.
136  */
137
138 static __u32 ShiftsGE(__u32 x)
139 {
140         int extraBits;
141         int nShifts;
142
143         nShifts = extraBits = 0;
144
145         while (x > 1) {
146                 if (x & 1)
147                         extraBits++;
148                 x >>= 1;
149                 nShifts++;
150         }
151
152         if (extraBits)
153                 nShifts++;
154
155         return nShifts;
156 }
157
158 /* Function to return the number of shifts to get a 1 in bit 0
159  */
160
161 static __u32 Shifts(__u32 x)
162 {
163         __u32 nShifts;
164
165         nShifts =  0;
166
167         if (!x)
168                 return 0;
169
170         while (!(x&1)) {
171                 x >>= 1;
172                 nShifts++;
173         }
174
175         return nShifts;
176 }
177
178
179
180 /*
181  * Temporary buffer manipulations.
182  */
183
184 static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)
185 {
186         int i;
187         __u8 *buf = (__u8 *)1;
188
189         memset(dev->tempBuffer, 0, sizeof(dev->tempBuffer));
190
191         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
192                 dev->tempBuffer[i].line = 0;    /* not in use */
193                 dev->tempBuffer[i].buffer = buf =
194                     YMALLOC_DMA(dev->param.totalBytesPerChunk);
195         }
196
197         return buf ? YAFFS_OK : YAFFS_FAIL;
198 }
199
200 __u8 *yaffs_GetTempBuffer(yaffs_Device *dev, int lineNo)
201 {
202         int i, j;
203
204         dev->tempInUse++;
205         if (dev->tempInUse > dev->maxTemp)
206                 dev->maxTemp = dev->tempInUse;
207
208         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
209                 if (dev->tempBuffer[i].line == 0) {
210                         dev->tempBuffer[i].line = lineNo;
211                         if ((i + 1) > dev->maxTemp) {
212                                 dev->maxTemp = i + 1;
213                                 for (j = 0; j <= i; j++)
214                                         dev->tempBuffer[j].maxLine =
215                                             dev->tempBuffer[j].line;
216                         }
217
218                         return dev->tempBuffer[i].buffer;
219                 }
220         }
221
222         T(YAFFS_TRACE_BUFFERS,
223           (TSTR("Out of temp buffers at line %d, other held by lines:"),
224            lineNo));
225         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
226                 T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
227
228         T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
229
230         /*
231          * If we got here then we have to allocate an unmanaged one
232          * This is not good.
233          */
234
235         dev->unmanagedTempAllocations++;
236         return YMALLOC(dev->nDataBytesPerChunk);
237
238 }
239
240 void yaffs_ReleaseTempBuffer(yaffs_Device *dev, __u8 *buffer,
241                                     int lineNo)
242 {
243         int i;
244
245         dev->tempInUse--;
246
247         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
248                 if (dev->tempBuffer[i].buffer == buffer) {
249                         dev->tempBuffer[i].line = 0;
250                         return;
251                 }
252         }
253
254         if (buffer) {
255                 /* assume it is an unmanaged one. */
256                 T(YAFFS_TRACE_BUFFERS,
257                   (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
258                    lineNo));
259                 YFREE(buffer);
260                 dev->unmanagedTempDeallocations++;
261         }
262
263 }
264
265 /*
266  * Determine if we have a managed buffer.
267  */
268 int yaffs_IsManagedTempBuffer(yaffs_Device *dev, const __u8 *buffer)
269 {
270         int i;
271
272         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
273                 if (dev->tempBuffer[i].buffer == buffer)
274                         return 1;
275         }
276
277         for (i = 0; i < dev->param.nShortOpCaches; i++) {
278                 if (dev->srCache[i].data == buffer)
279                         return 1;
280         }
281
282         if (buffer == dev->checkpointBuffer)
283                 return 1;
284
285         T(YAFFS_TRACE_ALWAYS,
286                 (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
287         return 0;
288 }
289
290 /*
291  * Verification code
292  */
293
294
295
296
297 /*
298  *  Simple hash function. Needs to have a reasonable spread
299  */
300
301 static Y_INLINE int yaffs_HashFunction(int n)
302 {
303         n = abs(n);
304         return n % YAFFS_NOBJECT_BUCKETS;
305 }
306
307 /*
308  * Access functions to useful fake objects.
309  * Note that root might have a presence in NAND if permissions are set.
310  */
311
312 yaffs_Object *yaffs_Root(yaffs_Device *dev)
313 {
314         return dev->rootDir;
315 }
316
317 yaffs_Object *yaffs_LostNFound(yaffs_Device *dev)
318 {
319         return dev->lostNFoundDir;
320 }
321
322
323 /*
324  *  Erased NAND checking functions
325  */
326
327 int yaffs_CheckFF(__u8 *buffer, int nBytes)
328 {
329         /* Horrible, slow implementation */
330         while (nBytes--) {
331                 if (*buffer != 0xFF)
332                         return 0;
333                 buffer++;
334         }
335         return 1;
336 }
337
338 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
339                                 int chunkInNAND)
340 {
341         int retval = YAFFS_OK;
342         __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
343         yaffs_ExtendedTags tags;
344         int result;
345
346         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
347
348         if (tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
349                 retval = YAFFS_FAIL;
350
351         if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
352                 T(YAFFS_TRACE_NANDACCESS,
353                   (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
354                 retval = YAFFS_FAIL;
355         }
356
357         yaffs_ReleaseTempBuffer(dev, data, __LINE__);
358
359         return retval;
360
361 }
362
363
364 static int yaffs_VerifyChunkWritten(yaffs_Device *dev,
365                                         int chunkInNAND,
366                                         const __u8 *data,
367                                         yaffs_ExtendedTags *tags)
368 {
369         int retval = YAFFS_OK;
370         yaffs_ExtendedTags tempTags;
371         __u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
372         int result;
373         
374         result = yaffs_ReadChunkWithTagsFromNAND(dev,chunkInNAND,buffer,&tempTags);
375         if(memcmp(buffer,data,dev->nDataBytesPerChunk) ||
376                 tempTags.objectId != tags->objectId ||
377                 tempTags.chunkId  != tags->chunkId ||
378                 tempTags.byteCount != tags->byteCount)
379                 retval = YAFFS_FAIL;
380
381         yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
382
383         return retval;
384 }
385
386 static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
387                                         const __u8 *data,
388                                         yaffs_ExtendedTags *tags,
389                                         int useReserve)
390 {
391         int attempts = 0;
392         int writeOk = 0;
393         int chunk;
394
395         yaffs2_InvalidateCheckpoint(dev);
396
397         do {
398                 yaffs_BlockInfo *bi = 0;
399                 int erasedOk = 0;
400
401                 chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
402                 if (chunk < 0) {
403                         /* no space */
404                         break;
405                 }
406
407                 /* First check this chunk is erased, if it needs
408                  * checking.  The checking policy (unless forced
409                  * always on) is as follows:
410                  *
411                  * Check the first page we try to write in a block.
412                  * If the check passes then we don't need to check any
413                  * more.        If the check fails, we check again...
414                  * If the block has been erased, we don't need to check.
415                  *
416                  * However, if the block has been prioritised for gc,
417                  * then we think there might be something odd about
418                  * this block and stop using it.
419                  *
420                  * Rationale: We should only ever see chunks that have
421                  * not been erased if there was a partially written
422                  * chunk due to power loss.  This checking policy should
423                  * catch that case with very few checks and thus save a
424                  * lot of checks that are most likely not needed.
425                  *
426                  * Mods to the above
427                  * If an erase check fails or the write fails we skip the 
428                  * rest of the block.
429                  */
430
431                 /* let's give it a try */
432                 attempts++;
433
434 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
435                 bi->skipErasedCheck = 0;
436 #endif
437                 if (!bi->skipErasedCheck) {
438                         erasedOk = yaffs_CheckChunkErased(dev, chunk);
439                         if (erasedOk != YAFFS_OK) {
440                                 T(YAFFS_TRACE_ERROR,
441                                 (TSTR("**>> yaffs chunk %d was not erased"
442                                 TENDSTR), chunk));
443
444                                 /* If not erased, delete this one,
445                                  * skip rest of block and
446                                  * try another chunk */
447                                  yaffs_DeleteChunk(dev,chunk,1,__LINE__);
448                                  yaffs_SkipRestOfBlock(dev);
449                                 continue;
450                         }
451                 }
452
453                 writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
454                                 data, tags);
455
456                 if(!bi->skipErasedCheck)
457                         writeOk = yaffs_VerifyChunkWritten(dev, chunk, data, tags);
458
459                 if (writeOk != YAFFS_OK) {
460                         /* Clean up aborted write, skip to next block and
461                          * try another chunk */
462                         yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
463                         continue;
464                 }
465
466                 bi->skipErasedCheck = 1;
467
468                 /* Copy the data into the robustification buffer */
469                 yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
470
471         } while (writeOk != YAFFS_OK &&
472                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
473
474         if (!writeOk)
475                 chunk = -1;
476
477         if (attempts > 1) {
478                 T(YAFFS_TRACE_ERROR,
479                         (TSTR("**>> yaffs write required %d attempts" TENDSTR),
480                         attempts));
481
482                 dev->nRetriedWrites += (attempts - 1);
483         }
484
485         return chunk;
486 }
487
488
489  
490 /*
491  * Block retiring for handling a broken block.
492  */
493
494 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND)
495 {
496         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
497
498         yaffs2_InvalidateCheckpoint(dev);
499         
500         yaffs2_ClearOldestDirtySequence(dev,bi);
501
502         if (yaffs_MarkBlockBad(dev, blockInNAND) != YAFFS_OK) {
503                 if (yaffs_EraseBlockInNAND(dev, blockInNAND) != YAFFS_OK) {
504                         T(YAFFS_TRACE_ALWAYS, (TSTR(
505                                 "yaffs: Failed to mark bad and erase block %d"
506                                 TENDSTR), blockInNAND));
507                 } else {
508                         yaffs_ExtendedTags tags;
509                         int chunkId = blockInNAND * dev->param.nChunksPerBlock;
510
511                         __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
512
513                         memset(buffer, 0xff, dev->nDataBytesPerChunk);
514                         yaffs_InitialiseTags(&tags);
515                         tags.sequenceNumber = YAFFS_SEQUENCE_BAD_BLOCK;
516                         if (dev->param.writeChunkWithTagsToNAND(dev, chunkId -
517                                 dev->chunkOffset, buffer, &tags) != YAFFS_OK)
518                                 T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Failed to "
519                                         TCONT("write bad block marker to block %d")
520                                         TENDSTR), blockInNAND));
521
522                         yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
523                 }
524         }
525
526         bi->blockState = YAFFS_BLOCK_STATE_DEAD;
527         bi->gcPrioritise = 0;
528         bi->needsRetiring = 0;
529
530         dev->nRetiredBlocks++;
531 }
532
533 /*
534  * Functions for robustisizing TODO
535  *
536  */
537
538 static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
539                                 const __u8 *data,
540                                 const yaffs_ExtendedTags *tags)
541 {
542         dev=dev;
543         chunkInNAND=chunkInNAND;
544         data=data;
545         tags=tags;
546 }
547
548 static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
549                                 const yaffs_ExtendedTags *tags)
550 {
551         dev=dev;
552         chunkInNAND=chunkInNAND;
553         tags=tags;
554 }
555
556 void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
557 {
558         if (!bi->gcPrioritise) {
559                 bi->gcPrioritise = 1;
560                 dev->hasPendingPrioritisedGCs = 1;
561                 bi->chunkErrorStrikes++;
562
563                 if (bi->chunkErrorStrikes > 3) {
564                         bi->needsRetiring = 1; /* Too many stikes, so retire this */
565                         T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));
566
567                 }
568         }
569 }
570
571 static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND,
572                 int erasedOk)
573 {
574         int blockInNAND = chunkInNAND / dev->param.nChunksPerBlock;
575         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
576
577         yaffs_HandleChunkError(dev, bi);
578
579         if (erasedOk) {
580                 /* Was an actual write failure, so mark the block for retirement  */
581                 bi->needsRetiring = 1;
582                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
583                   (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));
584         }
585
586         /* Delete the chunk */
587         yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
588         yaffs_SkipRestOfBlock(dev);
589 }
590
591
592 /*---------------- Name handling functions ------------*/
593
594 static __u16 yaffs_CalcNameSum(const YCHAR *name)
595 {
596         __u16 sum = 0;
597         __u16 i = 1;
598
599         const YUCHAR *bname = (const YUCHAR *) name;
600         if (bname) {
601                 while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
602
603 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
604                         sum += yaffs_toupper(*bname) * i;
605 #else
606                         sum += (*bname) * i;
607 #endif
608                         i++;
609                         bname++;
610                 }
611         }
612         return sum;
613 }
614
615 void yaffs_SetObjectName(yaffs_Object *obj, const YCHAR *name)
616 {
617 #ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
618         memset(obj->shortName, 0, sizeof(YCHAR) * (YAFFS_SHORT_NAME_LENGTH+1));
619         if (name && yaffs_strnlen(name,YAFFS_SHORT_NAME_LENGTH+1) <= YAFFS_SHORT_NAME_LENGTH)
620                 yaffs_strcpy(obj->shortName, name);
621         else
622                 obj->shortName[0] = _Y('\0');
623 #endif
624         obj->sum = yaffs_CalcNameSum(name);
625 }
626
627 void yaffs_SetObjectNameFromOH(yaffs_Object *obj, const yaffs_ObjectHeader *oh)
628 {
629 #ifdef CONFIG_YAFFS_AUTO_UNICODE
630         YCHAR tmpName[YAFFS_MAX_NAME_LENGTH+1];
631         memset(tmpName,0,sizeof(tmpName));
632         yaffs_LoadNameFromObjectHeader(obj->myDev,tmpName,oh->name,YAFFS_MAX_NAME_LENGTH+1);
633         yaffs_SetObjectName(obj,tmpName);
634 #else
635         yaffs_SetObjectName(obj,oh->name);
636 #endif
637 }
638
639 /*-------------------- TNODES -------------------
640
641  * List of spare tnodes
642  * The list is hooked together using the first pointer
643  * in the tnode.
644  */
645
646
647 yaffs_Tnode *yaffs_GetTnode(yaffs_Device *dev)
648 {
649         yaffs_Tnode *tn = yaffs_AllocateRawTnode(dev);
650         if (tn){
651                 memset(tn, 0, dev->tnodeSize);
652                 dev->nTnodes++;
653         }
654
655         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
656
657         return tn;
658 }
659
660 /* FreeTnode frees up a tnode and puts it back on the free list */
661 static void yaffs_FreeTnode(yaffs_Device *dev, yaffs_Tnode *tn)
662 {
663         yaffs_FreeRawTnode(dev,tn);
664         dev->nTnodes--;
665         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
666 }
667
668 static void yaffs_DeinitialiseTnodesAndObjects(yaffs_Device *dev)
669 {
670         yaffs_DeinitialiseRawTnodesAndObjects(dev);
671         dev->nObjects = 0;
672         dev->nTnodes = 0;
673 }
674
675
676 void yaffs_LoadLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos,
677                 unsigned val)
678 {
679         __u32 *map = (__u32 *)tn;
680         __u32 bitInMap;
681         __u32 bitInWord;
682         __u32 wordInMap;
683         __u32 mask;
684
685         pos &= YAFFS_TNODES_LEVEL0_MASK;
686         val >>= dev->chunkGroupBits;
687
688         bitInMap = pos * dev->tnodeWidth;
689         wordInMap = bitInMap / 32;
690         bitInWord = bitInMap & (32 - 1);
691
692         mask = dev->tnodeMask << bitInWord;
693
694         map[wordInMap] &= ~mask;
695         map[wordInMap] |= (mask & (val << bitInWord));
696
697         if (dev->tnodeWidth > (32 - bitInWord)) {
698                 bitInWord = (32 - bitInWord);
699                 wordInMap++;;
700                 mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
701                 map[wordInMap] &= ~mask;
702                 map[wordInMap] |= (mask & (val >> bitInWord));
703         }
704 }
705
706 __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn,
707                 unsigned pos)
708 {
709         __u32 *map = (__u32 *)tn;
710         __u32 bitInMap;
711         __u32 bitInWord;
712         __u32 wordInMap;
713         __u32 val;
714
715         pos &= YAFFS_TNODES_LEVEL0_MASK;
716
717         bitInMap = pos * dev->tnodeWidth;
718         wordInMap = bitInMap / 32;
719         bitInWord = bitInMap & (32 - 1);
720
721         val = map[wordInMap] >> bitInWord;
722
723         if      (dev->tnodeWidth > (32 - bitInWord)) {
724                 bitInWord = (32 - bitInWord);
725                 wordInMap++;;
726                 val |= (map[wordInMap] << bitInWord);
727         }
728
729         val &= dev->tnodeMask;
730         val <<= dev->chunkGroupBits;
731
732         return val;
733 }
734
735 /* ------------------- End of individual tnode manipulation -----------------*/
736
737 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
738  * The look up tree is represented by the top tnode and the number of topLevel
739  * in the tree. 0 means only the level 0 tnode is in the tree.
740  */
741
742 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
743 yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,
744                                         yaffs_FileStructure *fStruct,
745                                         __u32 chunkId)
746 {
747         yaffs_Tnode *tn = fStruct->top;
748         __u32 i;
749         int requiredTallness;
750         int level = fStruct->topLevel;
751
752         dev=dev;
753
754         /* Check sane level and chunk Id */
755         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
756                 return NULL;
757
758         if (chunkId > YAFFS_MAX_CHUNK_ID)
759                 return NULL;
760
761         /* First check we're tall enough (ie enough topLevel) */
762
763         i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
764         requiredTallness = 0;
765         while (i) {
766                 i >>= YAFFS_TNODES_INTERNAL_BITS;
767                 requiredTallness++;
768         }
769
770         if (requiredTallness > fStruct->topLevel)
771                 return NULL; /* Not tall enough, so we can't find it */
772
773         /* Traverse down to level 0 */
774         while (level > 0 && tn) {
775                 tn = tn->internal[(chunkId >>
776                         (YAFFS_TNODES_LEVEL0_BITS +
777                                 (level - 1) *
778                                 YAFFS_TNODES_INTERNAL_BITS)) &
779                         YAFFS_TNODES_INTERNAL_MASK];
780                 level--;
781         }
782
783         return tn;
784 }
785
786 /* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
787  * This happens in two steps:
788  *  1. If the tree isn't tall enough, then make it taller.
789  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
790  *
791  * Used when modifying the tree.
792  *
793  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
794  *  be plugged into the ttree.
795  */
796
797 yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device *dev,
798                                         yaffs_FileStructure *fStruct,
799                                         __u32 chunkId,
800                                         yaffs_Tnode *passedTn)
801 {
802         int requiredTallness;
803         int i;
804         int l;
805         yaffs_Tnode *tn;
806
807         __u32 x;
808
809
810         /* Check sane level and page Id */
811         if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL)
812                 return NULL;
813
814         if (chunkId > YAFFS_MAX_CHUNK_ID)
815                 return NULL;
816
817         /* First check we're tall enough (ie enough topLevel) */
818
819         x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
820         requiredTallness = 0;
821         while (x) {
822                 x >>= YAFFS_TNODES_INTERNAL_BITS;
823                 requiredTallness++;
824         }
825
826
827         if (requiredTallness > fStruct->topLevel) {
828                 /* Not tall enough, gotta make the tree taller */
829                 for (i = fStruct->topLevel; i < requiredTallness; i++) {
830
831                         tn = yaffs_GetTnode(dev);
832
833                         if (tn) {
834                                 tn->internal[0] = fStruct->top;
835                                 fStruct->top = tn;
836                                 fStruct->topLevel++;
837                         } else {
838                                 T(YAFFS_TRACE_ERROR,
839                                         (TSTR("yaffs: no more tnodes" TENDSTR)));
840                                 return NULL;
841                         }
842                 }
843         }
844
845         /* Traverse down to level 0, adding anything we need */
846
847         l = fStruct->topLevel;
848         tn = fStruct->top;
849
850         if (l > 0) {
851                 while (l > 0 && tn) {
852                         x = (chunkId >>
853                              (YAFFS_TNODES_LEVEL0_BITS +
854                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
855                             YAFFS_TNODES_INTERNAL_MASK;
856
857
858                         if ((l > 1) && !tn->internal[x]) {
859                                 /* Add missing non-level-zero tnode */
860                                 tn->internal[x] = yaffs_GetTnode(dev);
861                                 if(!tn->internal[x])
862                                         return NULL;
863                         } else if (l == 1) {
864                                 /* Looking from level 1 at level 0 */
865                                 if (passedTn) {
866                                         /* If we already have one, then release it.*/
867                                         if (tn->internal[x])
868                                                 yaffs_FreeTnode(dev, tn->internal[x]);
869                                         tn->internal[x] = passedTn;
870
871                                 } else if (!tn->internal[x]) {
872                                         /* Don't have one, none passed in */
873                                         tn->internal[x] = yaffs_GetTnode(dev);
874                                         if(!tn->internal[x])
875                                                 return NULL;
876                                 }
877                         }
878
879                         tn = tn->internal[x];
880                         l--;
881                 }
882         } else {
883                 /* top is level 0 */
884                 if (passedTn) {
885                         memcpy(tn, passedTn, (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
886                         yaffs_FreeTnode(dev, passedTn);
887                 }
888         }
889
890         return tn;
891 }
892
893 static int yaffs_FindChunkInGroup(yaffs_Device *dev, int theChunk,
894                                 yaffs_ExtendedTags *tags, int objectId,
895                                 int chunkInInode)
896 {
897         int j;
898
899         for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
900                 if (yaffs_CheckChunkBit(dev, theChunk / dev->param.nChunksPerBlock,
901                                 theChunk % dev->param.nChunksPerBlock)) {
902                         
903                         if(dev->chunkGroupSize == 1)
904                                 return theChunk;
905                         else {
906                                 yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
907                                                                 tags);
908                                 if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
909                                         /* found it; */
910                                         return theChunk;
911                                 }
912                         }
913                 }
914                 theChunk++;
915         }
916         return -1;
917 }
918
919 #if 0
920 /* Experimental code not being used yet. Might speed up file deletion */
921 /* DeleteWorker scans backwards through the tnode tree and deletes all the
922  * chunks and tnodes in the file.
923  * Returns 1 if the tree was deleted.
924  * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
925  */
926
927 static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
928                               int chunkOffset, int *limit)
929 {
930         int i;
931         int chunkInInode;
932         int theChunk;
933         yaffs_ExtendedTags tags;
934         int foundChunk;
935         yaffs_Device *dev = in->myDev;
936
937         int allDone = 1;
938
939         if (tn) {
940                 if (level > 0) {
941                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
942                              i--) {
943                                 if (tn->internal[i]) {
944                                         if (limit && (*limit) < 0) {
945                                                 allDone = 0;
946                                         } else {
947                                                 allDone =
948                                                         yaffs_DeleteWorker(in,
949                                                                 tn->
950                                                                 internal
951                                                                 [i],
952                                                                 level -
953                                                                 1,
954                                                                 (chunkOffset
955                                                                         <<
956                                                                         YAFFS_TNODES_INTERNAL_BITS)
957                                                                 + i,
958                                                                 limit);
959                                         }
960                                         if (allDone) {
961                                                 yaffs_FreeTnode(dev,
962                                                                 tn->
963                                                                 internal[i]);
964                                                 tn->internal[i] = NULL;
965                                         }
966                                 }
967                         }
968                         return (allDone) ? 1 : 0;
969                 } else if (level == 0) {
970                         int hitLimit = 0;
971
972                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
973                                         i--) {
974                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
975                                 if (theChunk) {
976
977                                         chunkInInode = (chunkOffset <<
978                                                 YAFFS_TNODES_LEVEL0_BITS) + i;
979
980                                         foundChunk =
981                                                 yaffs_FindChunkInGroup(dev,
982                                                                 theChunk,
983                                                                 &tags,
984                                                                 in->objectId,
985                                                                 chunkInInode);
986
987                                         if (foundChunk > 0) {
988                                                 yaffs_DeleteChunk(dev,
989                                                                   foundChunk, 1,
990                                                                   __LINE__);
991                                                 in->nDataChunks--;
992                                                 if (limit) {
993                                                         *limit = *limit - 1;
994                                                         if (*limit <= 0)
995                                                                 hitLimit = 1;
996                                                 }
997
998                                         }
999
1000                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1001                                 }
1002
1003                         }
1004                         return (i < 0) ? 1 : 0;
1005
1006                 }
1007
1008         }
1009
1010         return 1;
1011
1012 }
1013
1014 #endif
1015
1016 static void yaffs_SoftDeleteChunk(yaffs_Device *dev, int chunk)
1017 {
1018         yaffs_BlockInfo *theBlock;
1019         unsigned blockNo;
1020
1021         T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
1022
1023         blockNo =  chunk / dev->param.nChunksPerBlock;
1024         theBlock = yaffs_GetBlockInfo(dev, blockNo);
1025         if (theBlock) {
1026                 theBlock->softDeletions++;
1027                 dev->nFreeChunks++;
1028                 yaffs2_UpdateOldestDirtySequence(dev, blockNo, theBlock);
1029         }
1030 }
1031
1032 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1033  * All soft deleting does is increment the block's softdelete count and pulls the chunk out
1034  * of the tnode.
1035  * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1036  */
1037
1038 static int yaffs_SoftDeleteWorker(yaffs_Object *in, yaffs_Tnode *tn,
1039                                   __u32 level, int chunkOffset)
1040 {
1041         int i;
1042         int theChunk;
1043         int allDone = 1;
1044         yaffs_Device *dev = in->myDev;
1045
1046         if (tn) {
1047                 if (level > 0) {
1048
1049                         for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
1050                              i--) {
1051                                 if (tn->internal[i]) {
1052                                         allDone =
1053                                             yaffs_SoftDeleteWorker(in,
1054                                                                    tn->
1055                                                                    internal[i],
1056                                                                    level - 1,
1057                                                                    (chunkOffset
1058                                                                     <<
1059                                                                     YAFFS_TNODES_INTERNAL_BITS)
1060                                                                    + i);
1061                                         if (allDone) {
1062                                                 yaffs_FreeTnode(dev,
1063                                                                 tn->
1064                                                                 internal[i]);
1065                                                 tn->internal[i] = NULL;
1066                                         } else {
1067                                                 /* Hoosterman... how could this happen? */
1068                                         }
1069                                 }
1070                         }
1071                         return (allDone) ? 1 : 0;
1072                 } else if (level == 0) {
1073
1074                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1075                                 theChunk = yaffs_GetChunkGroupBase(dev, tn, i);
1076                                 if (theChunk) {
1077                                         /* Note this does not find the real chunk, only the chunk group.
1078                                          * We make an assumption that a chunk group is not larger than
1079                                          * a block.
1080                                          */
1081                                         yaffs_SoftDeleteChunk(dev, theChunk);
1082                                         yaffs_LoadLevel0Tnode(dev, tn, i, 0);
1083                                 }
1084
1085                         }
1086                         return 1;
1087
1088                 }
1089
1090         }
1091
1092         return 1;
1093
1094 }
1095
1096 static void yaffs_SoftDeleteFile(yaffs_Object *obj)
1097 {
1098         if (obj->deleted &&
1099             obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
1100                 if (obj->nDataChunks <= 0) {
1101                         /* Empty file with no duplicate object headers, just delete it immediately */
1102                         yaffs_FreeTnode(obj->myDev,
1103                                         obj->variant.fileVariant.top);
1104                         obj->variant.fileVariant.top = NULL;
1105                         T(YAFFS_TRACE_TRACING,
1106                           (TSTR("yaffs: Deleting empty file %d" TENDSTR),
1107                            obj->objectId));
1108                         yaffs_DoGenericObjectDeletion(obj);
1109                 } else {
1110                         yaffs_SoftDeleteWorker(obj,
1111                                                obj->variant.fileVariant.top,
1112                                                obj->variant.fileVariant.
1113                                                topLevel, 0);
1114                         obj->softDeleted = 1;
1115                 }
1116         }
1117 }
1118
1119 /* Pruning removes any part of the file structure tree that is beyond the
1120  * bounds of the file (ie that does not point to chunks).
1121  *
1122  * A file should only get pruned when its size is reduced.
1123  *
1124  * Before pruning, the chunks must be pulled from the tree and the
1125  * level 0 tnode entries must be zeroed out.
1126  * Could also use this for file deletion, but that's probably better handled
1127  * by a special case.
1128  *
1129  * This function is recursive. For levels > 0 the function is called again on
1130  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1131  * If there is no data in a subtree then it is pruned.
1132  */
1133
1134 static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device *dev, yaffs_Tnode *tn,
1135                                 __u32 level, int del0)
1136 {
1137         int i;
1138         int hasData;
1139
1140         if (tn) {
1141                 hasData = 0;
1142
1143                 if(level > 0){
1144                         for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1145                                 if (tn->internal[i]) {
1146                                         tn->internal[i] =
1147                                                 yaffs_PruneWorker(dev, tn->internal[i],
1148                                                         level - 1,
1149                                                         (i == 0) ? del0 : 1);
1150                                 }
1151
1152                                 if (tn->internal[i])
1153                                         hasData++;
1154                         }
1155                 } else {
1156                         int tnodeSize_u32 = dev->tnodeSize/sizeof(__u32);
1157                         __u32 *map = (__u32 *)tn;
1158
1159                         for(i = 0; !hasData && i < tnodeSize_u32; i++){
1160                                 if(map[i])
1161                                         hasData++;
1162                         }
1163                 }
1164
1165                 if (hasData == 0 && del0) {
1166                         /* Free and return NULL */
1167
1168                         yaffs_FreeTnode(dev, tn);
1169                         tn = NULL;
1170                 }
1171
1172         }
1173
1174         return tn;
1175
1176 }
1177
1178 static int yaffs_PruneFileStructure(yaffs_Device *dev,
1179                                 yaffs_FileStructure *fStruct)
1180 {
1181         int i;
1182         int hasData;
1183         int done = 0;
1184         yaffs_Tnode *tn;
1185
1186         if (fStruct->topLevel > 0) {
1187                 fStruct->top =
1188                     yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);
1189
1190                 /* Now we have a tree with all the non-zero branches NULL but the height
1191                  * is the same as it was.
1192                  * Let's see if we can trim internal tnodes to shorten the tree.
1193                  * We can do this if only the 0th element in the tnode is in use
1194                  * (ie all the non-zero are NULL)
1195                  */
1196
1197                 while (fStruct->topLevel && !done) {
1198                         tn = fStruct->top;
1199
1200                         hasData = 0;
1201                         for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1202                                 if (tn->internal[i])
1203                                         hasData++;
1204                         }
1205
1206                         if (!hasData) {
1207                                 fStruct->top = tn->internal[0];
1208                                 fStruct->topLevel--;
1209                                 yaffs_FreeTnode(dev, tn);
1210                         } else {
1211                                 done = 1;
1212                         }
1213                 }
1214         }
1215
1216         return YAFFS_OK;
1217 }
1218
1219 /*-------------------- End of File Structure functions.-------------------*/
1220
1221
1222 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
1223 static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
1224 {
1225         yaffs_Object *obj = yaffs_AllocateRawObject(dev);
1226
1227         if (obj) {
1228                 dev->nObjects++;
1229
1230                 /* Now sweeten it up... */
1231
1232                 memset(obj, 0, sizeof(yaffs_Object));
1233                 obj->beingCreated = 1;
1234
1235                 obj->myDev = dev;
1236                 obj->hdrChunk = 0;
1237                 obj->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
1238                 YINIT_LIST_HEAD(&(obj->hardLinks));
1239                 YINIT_LIST_HEAD(&(obj->hashLink));
1240                 YINIT_LIST_HEAD(&obj->siblings);
1241
1242
1243                 /* Now make the directory sane */
1244                 if (dev->rootDir) {
1245                         obj->parent = dev->rootDir;
1246                         ylist_add(&(obj->siblings), &dev->rootDir->variant.directoryVariant.children);
1247                 }
1248
1249                 /* Add it to the lost and found directory.
1250                  * NB Can't put root or lostNFound in lostNFound so
1251                  * check if lostNFound exists first
1252                  */
1253                 if (dev->lostNFoundDir)
1254                         yaffs_AddObjectToDirectory(dev->lostNFoundDir, obj);
1255
1256                 obj->beingCreated = 0;
1257         }
1258
1259         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1260
1261         return obj;
1262 }
1263
1264 static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev, int number,
1265                                                __u32 mode)
1266 {
1267
1268         yaffs_Object *obj =
1269             yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1270         if (obj) {
1271                 obj->fake = 1;          /* it is fake so it might have no NAND presence... */
1272                 obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
1273                 obj->unlinkAllowed = 0; /* ... or unlink it */
1274                 obj->deleted = 0;
1275                 obj->unlinked = 0;
1276                 obj->yst_mode = mode;
1277                 obj->myDev = dev;
1278                 obj->hdrChunk = 0;      /* Not a valid chunk. */
1279         }
1280
1281         return obj;
1282
1283 }
1284
1285 static void yaffs_UnhashObject(yaffs_Object *obj)
1286 {
1287         int bucket;
1288         yaffs_Device *dev = obj->myDev;
1289
1290         /* If it is still linked into the bucket list, free from the list */
1291         if (!ylist_empty(&obj->hashLink)) {
1292                 ylist_del_init(&obj->hashLink);
1293                 bucket = yaffs_HashFunction(obj->objectId);
1294                 dev->objectBucket[bucket].count--;
1295         }
1296 }
1297
1298 /*  FreeObject frees up a Object and puts it back on the free list */
1299 static void yaffs_FreeObject(yaffs_Object *obj)
1300 {
1301         yaffs_Device *dev = obj->myDev;
1302
1303         T(YAFFS_TRACE_OS, (TSTR("FreeObject %p inode %p"TENDSTR), obj, obj->myInode));
1304
1305         if (!obj)
1306                 YBUG();
1307         if (obj->parent)
1308                 YBUG();
1309         if (!ylist_empty(&obj->siblings))
1310                 YBUG();
1311
1312
1313         if (obj->myInode) {
1314                 /* We're still hooked up to a cached inode.
1315                  * Don't delete now, but mark for later deletion
1316                  */
1317                 obj->deferedFree = 1;
1318                 return;
1319         }
1320
1321         yaffs_UnhashObject(obj);
1322
1323         yaffs_FreeRawObject(dev,obj);
1324         dev->nObjects--;
1325         dev->nCheckpointBlocksRequired = 0; /* force recalculation*/
1326 }
1327
1328
1329 void yaffs_HandleDeferedFree(yaffs_Object *obj)
1330 {
1331         if (obj->deferedFree)
1332                 yaffs_FreeObject(obj);
1333 }
1334
1335 static void yaffs_InitialiseTnodesAndObjects(yaffs_Device *dev)
1336 {
1337         int i;
1338
1339         dev->nObjects = 0;
1340         dev->nTnodes = 0;
1341
1342         yaffs_InitialiseRawTnodesAndObjects(dev);
1343
1344         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
1345                 YINIT_LIST_HEAD(&dev->objectBucket[i].list);
1346                 dev->objectBucket[i].count = 0;
1347         }
1348 }
1349
1350 static int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
1351 {
1352         int i;
1353         int l = 999;
1354         int lowest = 999999;
1355
1356
1357         /* Search for the shortest list or one that
1358          * isn't too long.
1359          */
1360
1361         for (i = 0; i < 10 && lowest > 4; i++) {
1362                 dev->bucketFinder++;
1363                 dev->bucketFinder %= YAFFS_NOBJECT_BUCKETS;
1364                 if (dev->objectBucket[dev->bucketFinder].count < lowest) {
1365                         lowest = dev->objectBucket[dev->bucketFinder].count;
1366                         l = dev->bucketFinder;
1367                 }
1368
1369         }
1370
1371         return l;
1372 }
1373
1374 static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
1375 {
1376         int bucket = yaffs_FindNiceObjectBucket(dev);
1377
1378         /* Now find an object value that has not already been taken
1379          * by scanning the list.
1380          */
1381
1382         int found = 0;
1383         struct ylist_head *i;
1384
1385         __u32 n = (__u32) bucket;
1386
1387         /* yaffs_CheckObjectHashSanity();  */
1388
1389         while (!found) {
1390                 found = 1;
1391                 n += YAFFS_NOBJECT_BUCKETS;
1392                 if (1 || dev->objectBucket[bucket].count > 0) {
1393                         ylist_for_each(i, &dev->objectBucket[bucket].list) {
1394                                 /* If there is already one in the list */
1395                                 if (i && ylist_entry(i, yaffs_Object,
1396                                                 hashLink)->objectId == n) {
1397                                         found = 0;
1398                                 }
1399                         }
1400                 }
1401         }
1402
1403         return n;
1404 }
1405
1406 static void yaffs_HashObject(yaffs_Object *in)
1407 {
1408         int bucket = yaffs_HashFunction(in->objectId);
1409         yaffs_Device *dev = in->myDev;
1410
1411         ylist_add(&in->hashLink, &dev->objectBucket[bucket].list);
1412         dev->objectBucket[bucket].count++;
1413 }
1414
1415 yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev, __u32 number)
1416 {
1417         int bucket = yaffs_HashFunction(number);
1418         struct ylist_head *i;
1419         yaffs_Object *in;
1420
1421         ylist_for_each(i, &dev->objectBucket[bucket].list) {
1422                 /* Look if it is in the list */
1423                 if (i) {
1424                         in = ylist_entry(i, yaffs_Object, hashLink);
1425                         if (in->objectId == number) {
1426
1427                                 /* Don't tell the VFS about this one if it is defered free */
1428                                 if (in->deferedFree)
1429                                         return NULL;
1430
1431                                 return in;
1432                         }
1433                 }
1434         }
1435
1436         return NULL;
1437 }
1438
1439 yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
1440                                     yaffs_ObjectType type)
1441 {
1442         yaffs_Object *theObject=NULL;
1443         yaffs_Tnode *tn = NULL;
1444
1445         if (number < 0)
1446                 number = yaffs_CreateNewObjectNumber(dev);
1447
1448         if (type == YAFFS_OBJECT_TYPE_FILE) {
1449                 tn = yaffs_GetTnode(dev);
1450                 if (!tn)
1451                         return NULL;
1452         }
1453
1454         theObject = yaffs_AllocateEmptyObject(dev);
1455         if (!theObject){
1456                 if(tn)
1457                         yaffs_FreeTnode(dev,tn);
1458                 return NULL;
1459         }
1460
1461
1462         if (theObject) {
1463                 theObject->fake = 0;
1464                 theObject->renameAllowed = 1;
1465                 theObject->unlinkAllowed = 1;
1466                 theObject->objectId = number;
1467                 yaffs_HashObject(theObject);
1468                 theObject->variantType = type;
1469 #ifdef CONFIG_YAFFS_WINCE
1470                 yfsd_WinFileTimeNow(theObject->win_atime);
1471                 theObject->win_ctime[0] = theObject->win_mtime[0] =
1472                     theObject->win_atime[0];
1473                 theObject->win_ctime[1] = theObject->win_mtime[1] =
1474                     theObject->win_atime[1];
1475
1476 #else
1477
1478                 theObject->yst_atime = theObject->yst_mtime =
1479                     theObject->yst_ctime = Y_CURRENT_TIME;
1480 #endif
1481                 switch (type) {
1482                 case YAFFS_OBJECT_TYPE_FILE:
1483                         theObject->variant.fileVariant.fileSize = 0;
1484                         theObject->variant.fileVariant.scannedFileSize = 0;
1485                         theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
1486                         theObject->variant.fileVariant.topLevel = 0;
1487                         theObject->variant.fileVariant.top = tn;
1488                         break;
1489                 case YAFFS_OBJECT_TYPE_DIRECTORY:
1490                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
1491                                         children);
1492                         YINIT_LIST_HEAD(&theObject->variant.directoryVariant.
1493                                         dirty);
1494                         break;
1495                 case YAFFS_OBJECT_TYPE_SYMLINK:
1496                 case YAFFS_OBJECT_TYPE_HARDLINK:
1497                 case YAFFS_OBJECT_TYPE_SPECIAL:
1498                         /* No action required */
1499                         break;
1500                 case YAFFS_OBJECT_TYPE_UNKNOWN:
1501                         /* todo this should not happen */
1502                         break;
1503                 }
1504         }
1505
1506         return theObject;
1507 }
1508
1509 yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev,
1510                                                 int number,
1511                                                 yaffs_ObjectType type)
1512 {
1513         yaffs_Object *theObject = NULL;
1514
1515         if (number > 0)
1516                 theObject = yaffs_FindObjectByNumber(dev, number);
1517
1518         if (!theObject)
1519                 theObject = yaffs_CreateNewObject(dev, number, type);
1520
1521         return theObject;
1522
1523 }
1524
1525
1526 YCHAR *yaffs_CloneString(const YCHAR *str)
1527 {
1528         YCHAR *newStr = NULL;
1529         int len;
1530
1531         if (!str)
1532                 str = _Y("");
1533
1534         len = yaffs_strnlen(str,YAFFS_MAX_ALIAS_LENGTH);
1535         newStr = YMALLOC((len + 1) * sizeof(YCHAR));
1536         if (newStr){
1537                 yaffs_strncpy(newStr, str,len);
1538                 newStr[len] = 0;
1539         }
1540         return newStr;
1541
1542 }
1543
1544 /*
1545  * Mknod (create) a new object.
1546  * equivalentObject only has meaning for a hard link;
1547  * aliasString only has meaning for a symlink.
1548  * rdev only has meaning for devices (a subset of special objects)
1549  */
1550
1551 static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
1552                                        yaffs_Object *parent,
1553                                        const YCHAR *name,
1554                                        __u32 mode,
1555                                        __u32 uid,
1556                                        __u32 gid,
1557                                        yaffs_Object *equivalentObject,
1558                                        const YCHAR *aliasString, __u32 rdev)
1559 {
1560         yaffs_Object *in;
1561         YCHAR *str = NULL;
1562
1563         yaffs_Device *dev = parent->myDev;
1564
1565         /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
1566         if (yaffs_FindObjectByName(parent, name))
1567                 return NULL;
1568
1569         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
1570                 str = yaffs_CloneString(aliasString);
1571                 if (!str)
1572                         return NULL;
1573         }
1574
1575         in = yaffs_CreateNewObject(dev, -1, type);
1576
1577         if (!in){
1578                 if(str)
1579                         YFREE(str);
1580                 return NULL;
1581         }
1582
1583
1584
1585
1586
1587         if (in) {
1588                 in->hdrChunk = 0;
1589                 in->valid = 1;
1590                 in->variantType = type;
1591
1592                 in->yst_mode = mode;
1593
1594 #ifdef CONFIG_YAFFS_WINCE
1595                 yfsd_WinFileTimeNow(in->win_atime);
1596                 in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
1597                 in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
1598
1599 #else
1600                 in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
1601
1602                 in->yst_rdev = rdev;
1603                 in->yst_uid = uid;
1604                 in->yst_gid = gid;
1605 #endif
1606                 in->nDataChunks = 0;
1607
1608                 yaffs_SetObjectName(in, name);
1609                 in->dirty = 1;
1610
1611                 yaffs_AddObjectToDirectory(parent, in);
1612
1613                 in->myDev = parent->myDev;
1614
1615                 switch (type) {
1616                 case YAFFS_OBJECT_TYPE_SYMLINK:
1617                         in->variant.symLinkVariant.alias = str;
1618                         break;
1619                 case YAFFS_OBJECT_TYPE_HARDLINK:
1620                         in->variant.hardLinkVariant.equivalentObject =
1621                                 equivalentObject;
1622                         in->variant.hardLinkVariant.equivalentObjectId =
1623                                 equivalentObject->objectId;
1624                         ylist_add(&in->hardLinks, &equivalentObject->hardLinks);
1625                         break;
1626                 case YAFFS_OBJECT_TYPE_FILE:
1627                 case YAFFS_OBJECT_TYPE_DIRECTORY:
1628                 case YAFFS_OBJECT_TYPE_SPECIAL:
1629                 case YAFFS_OBJECT_TYPE_UNKNOWN:
1630                         /* do nothing */
1631                         break;
1632                 }
1633
1634                 if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0, NULL) < 0) {
1635                         /* Could not create the object header, fail the creation */
1636                         yaffs_DeleteObject(in);
1637                         in = NULL;
1638                 }
1639
1640                 yaffs_UpdateParent(parent);
1641         }
1642
1643         return in;
1644 }
1645
1646 yaffs_Object *yaffs_MknodFile(yaffs_Object *parent, const YCHAR *name,
1647                         __u32 mode, __u32 uid, __u32 gid)
1648 {
1649         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
1650                                 uid, gid, NULL, NULL, 0);
1651 }
1652
1653 yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent, const YCHAR *name,
1654                                 __u32 mode, __u32 uid, __u32 gid)
1655 {
1656         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
1657                                  mode, uid, gid, NULL, NULL, 0);
1658 }
1659
1660 yaffs_Object *yaffs_MknodSpecial(yaffs_Object *parent, const YCHAR *name,
1661                                 __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
1662 {
1663         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
1664                                  uid, gid, NULL, NULL, rdev);
1665 }
1666
1667 yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const YCHAR *name,
1668                                 __u32 mode, __u32 uid, __u32 gid,
1669                                 const YCHAR *alias)
1670 {
1671         return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
1672                                 uid, gid, NULL, alias, 0);
1673 }
1674
1675 /* yaffs_Link returns the object id of the equivalent object.*/
1676 yaffs_Object *yaffs_Link(yaffs_Object *parent, const YCHAR *name,
1677                         yaffs_Object *equivalentObject)
1678 {
1679         /* Get the real object in case we were fed a hard link as an equivalent object */
1680         equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
1681
1682         if (yaffs_MknodObject
1683             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
1684              equivalentObject, NULL, 0)) {
1685                 return equivalentObject;
1686         } else {
1687                 return NULL;
1688         }
1689
1690 }
1691
1692 static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir,
1693                                 const YCHAR *newName, int force, int shadows)
1694 {
1695         int unlinkOp;
1696         int deleteOp;
1697
1698         yaffs_Object *existingTarget;
1699
1700         if (newDir == NULL)
1701                 newDir = obj->parent;   /* use the old directory */
1702
1703         if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
1704                 T(YAFFS_TRACE_ALWAYS,
1705                   (TSTR
1706                    ("tragedy: yaffs_ChangeObjectName: newDir is not a directory"
1707                     TENDSTR)));
1708                 YBUG();
1709         }
1710
1711         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
1712         if (obj->myDev->param.isYaffs2)
1713                 unlinkOp = (newDir == obj->myDev->unlinkedDir);
1714         else
1715                 unlinkOp = (newDir == obj->myDev->unlinkedDir
1716                             && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
1717
1718         deleteOp = (newDir == obj->myDev->deletedDir);
1719
1720         existingTarget = yaffs_FindObjectByName(newDir, newName);
1721
1722         /* If the object is a file going into the unlinked directory,
1723          *   then it is OK to just stuff it in since duplicate names are allowed.
1724          *   else only proceed if the new name does not exist and if we're putting
1725          *   it into a directory.
1726          */
1727         if ((unlinkOp ||
1728              deleteOp ||
1729              force ||
1730              (shadows > 0) ||
1731              !existingTarget) &&
1732             newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
1733                 yaffs_SetObjectName(obj, newName);
1734                 obj->dirty = 1;
1735
1736                 yaffs_AddObjectToDirectory(newDir, obj);
1737
1738                 if (unlinkOp)
1739                         obj->unlinked = 1;
1740
1741                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
1742                 if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows, NULL) >= 0)
1743                         return YAFFS_OK;
1744         }
1745
1746         return YAFFS_FAIL;
1747 }
1748
1749 int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName,
1750                 yaffs_Object *newDir, const YCHAR *newName)
1751 {
1752         yaffs_Object *obj = NULL;
1753         yaffs_Object *existingTarget = NULL;
1754         int force = 0;
1755         int result;
1756         yaffs_Device *dev;
1757
1758
1759         if (!oldDir || oldDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
1760                 YBUG();
1761         if (!newDir || newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
1762                 YBUG();
1763
1764         dev = oldDir->myDev;
1765
1766 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
1767         /* Special case for case insemsitive systems (eg. WinCE).
1768          * While look-up is case insensitive, the name isn't.
1769          * Therefore we might want to change x.txt to X.txt
1770         */
1771         if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0)
1772                 force = 1;
1773 #endif
1774
1775         if(yaffs_strnlen(newName,YAFFS_MAX_NAME_LENGTH+1) > YAFFS_MAX_NAME_LENGTH)
1776                 /* ENAMETOOLONG */
1777                 return YAFFS_FAIL;
1778
1779         obj = yaffs_FindObjectByName(oldDir, oldName);
1780
1781         if (obj && obj->renameAllowed) {
1782
1783                 /* Now do the handling for an existing target, if there is one */
1784
1785                 existingTarget = yaffs_FindObjectByName(newDir, newName);
1786                 if (existingTarget &&
1787                         existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
1788                         !ylist_empty(&existingTarget->variant.directoryVariant.children)) {
1789                         /* There is a target that is a non-empty directory, so we fail */
1790                         return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
1791                 } else if (existingTarget && existingTarget != obj) {
1792                         /* Nuke the target first, using shadowing,
1793                          * but only if it isn't the same object.
1794                          *
1795                          * Note we must disable gc otherwise it can mess up the shadowing.
1796                          *
1797                          */
1798                         dev->gcDisable=1;
1799                         yaffs_ChangeObjectName(obj, newDir, newName, force,
1800                                                 existingTarget->objectId);
1801                         existingTarget->isShadowed = 1;
1802                         yaffs_UnlinkObject(existingTarget);
1803                         dev->gcDisable=0;
1804                 }
1805
1806                 result = yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
1807
1808                 yaffs_UpdateParent(oldDir);
1809                 if(newDir != oldDir)
1810                         yaffs_UpdateParent(newDir);
1811                 
1812                 return result;
1813         }
1814         return YAFFS_FAIL;
1815 }
1816
1817 /*------------------------- Block Management and Page Allocation ----------------*/
1818
1819 static int yaffs_InitialiseBlocks(yaffs_Device *dev)
1820 {
1821         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
1822
1823         dev->blockInfo = NULL;
1824         dev->chunkBits = NULL;
1825
1826         dev->allocationBlock = -1;      /* force it to get a new one */
1827
1828         /* If the first allocation strategy fails, thry the alternate one */
1829         dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
1830         if (!dev->blockInfo) {
1831                 dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
1832                 dev->blockInfoAlt = 1;
1833         } else
1834                 dev->blockInfoAlt = 0;
1835
1836         if (dev->blockInfo) {
1837                 /* Set up dynamic blockinfo stuff. */
1838                 dev->chunkBitmapStride = (dev->param.nChunksPerBlock + 7) / 8; /* round up bytes */
1839                 dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
1840                 if (!dev->chunkBits) {
1841                         dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
1842                         dev->chunkBitsAlt = 1;
1843                 } else
1844                         dev->chunkBitsAlt = 0;
1845         }
1846
1847         if (dev->blockInfo && dev->chunkBits) {
1848                 memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
1849                 memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
1850                 return YAFFS_OK;
1851         }
1852
1853         return YAFFS_FAIL;
1854 }
1855
1856 static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
1857 {
1858         if (dev->blockInfoAlt && dev->blockInfo)
1859                 YFREE_ALT(dev->blockInfo);
1860         else if (dev->blockInfo)
1861                 YFREE(dev->blockInfo);
1862
1863         dev->blockInfoAlt = 0;
1864
1865         dev->blockInfo = NULL;
1866
1867         if (dev->chunkBitsAlt && dev->chunkBits)
1868                 YFREE_ALT(dev->chunkBits);
1869         else if (dev->chunkBits)
1870                 YFREE(dev->chunkBits);
1871         dev->chunkBitsAlt = 0;
1872         dev->chunkBits = NULL;
1873 }
1874
1875 void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
1876 {
1877         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
1878
1879         int erasedOk = 0;
1880
1881         /* If the block is still healthy erase it and mark as clean.
1882          * If the block has had a data failure, then retire it.
1883          */
1884
1885         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
1886                 (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
1887                 blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
1888
1889         yaffs2_ClearOldestDirtySequence(dev,bi);
1890
1891         bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
1892
1893         /* If this is the block being garbage collected then stop gc'ing this block */
1894         if(blockNo == dev->gcBlock)
1895                 dev->gcBlock = 0;
1896
1897         /* If this block is currently the best candidate for gc then drop as a candidate */
1898         if(blockNo == dev->gcDirtiest){
1899                 dev->gcDirtiest = 0;
1900                 dev->gcPagesInUse = 0;
1901         }
1902
1903         if (!bi->needsRetiring) {
1904                 yaffs2_InvalidateCheckpoint(dev);
1905                 erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
1906                 if (!erasedOk) {
1907                         dev->nErasureFailures++;
1908                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
1909                           (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
1910                 }
1911         }
1912
1913         if (erasedOk &&
1914             ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
1915                 int i;
1916                 for (i = 0; i < dev->param.nChunksPerBlock; i++) {
1917                         if (!yaffs_CheckChunkErased
1918                             (dev, blockNo * dev->param.nChunksPerBlock + i)) {
1919                                 T(YAFFS_TRACE_ERROR,
1920                                   (TSTR
1921                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
1922                                     TENDSTR), blockNo, i));
1923                         }
1924                 }
1925         }
1926
1927         if (erasedOk) {
1928                 /* Clean it up... */
1929                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
1930                 bi->sequenceNumber = 0;
1931                 dev->nErasedBlocks++;
1932                 bi->pagesInUse = 0;
1933                 bi->softDeletions = 0;
1934                 bi->hasShrinkHeader = 0;
1935                 bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
1936                 bi->gcPrioritise = 0;
1937                 yaffs_ClearChunkBits(dev, blockNo);
1938
1939                 T(YAFFS_TRACE_ERASE,
1940                   (TSTR("Erased block %d" TENDSTR), blockNo));
1941         } else {
1942                 dev->nFreeChunks -= dev->param.nChunksPerBlock; /* We lost a block of free space */
1943
1944                 yaffs_RetireBlock(dev, blockNo);
1945                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
1946                   (TSTR("**>> Block %d retired" TENDSTR), blockNo));
1947         }
1948 }
1949
1950 static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
1951 {
1952         int i;
1953
1954         yaffs_BlockInfo *bi;
1955
1956         if (dev->nErasedBlocks < 1) {
1957                 /* Hoosterman we've got a problem.
1958                  * Can't get space to gc
1959                  */
1960                 T(YAFFS_TRACE_ERROR,
1961                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
1962
1963                 return -1;
1964         }
1965
1966         /* Find an empty block. */
1967
1968         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
1969                 dev->allocationBlockFinder++;
1970                 if (dev->allocationBlockFinder < dev->internalStartBlock
1971                     || dev->allocationBlockFinder > dev->internalEndBlock) {
1972                         dev->allocationBlockFinder = dev->internalStartBlock;
1973                 }
1974
1975                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
1976
1977                 if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
1978                         bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
1979                         dev->sequenceNumber++;
1980                         bi->sequenceNumber = dev->sequenceNumber;
1981                         dev->nErasedBlocks--;
1982                         T(YAFFS_TRACE_ALLOCATE,
1983                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
1984                            dev->allocationBlockFinder, dev->sequenceNumber,
1985                            dev->nErasedBlocks));
1986                         return dev->allocationBlockFinder;
1987                 }
1988         }
1989
1990         T(YAFFS_TRACE_ALWAYS,
1991           (TSTR
1992            ("yaffs tragedy: no more erased blocks, but there should have been %d"
1993             TENDSTR), dev->nErasedBlocks));
1994
1995         return -1;
1996 }
1997
1998
1999 /*
2000  * Check if there's space to allocate...
2001  * Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
2002  */
2003 int yaffs_CheckSpaceForAllocation(yaffs_Device *dev, int nChunks)
2004 {
2005         int reservedChunks;
2006         int reservedBlocks = dev->param.nReservedBlocks;
2007         int checkpointBlocks;
2008
2009         checkpointBlocks = yaffs2_CalcCheckpointBlocksRequired(dev);
2010
2011         reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->param.nChunksPerBlock);
2012
2013         return (dev->nFreeChunks > (reservedChunks + nChunks));
2014 }
2015
2016 static int yaffs_AllocateChunk(yaffs_Device *dev, int useReserve,
2017                 yaffs_BlockInfo **blockUsedPtr)
2018 {
2019         int retVal;
2020         yaffs_BlockInfo *bi;
2021
2022         if (dev->allocationBlock < 0) {
2023                 /* Get next block to allocate off */
2024                 dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
2025                 dev->allocationPage = 0;
2026         }
2027
2028         if (!useReserve && !yaffs_CheckSpaceForAllocation(dev, 1)) {
2029                 /* Not enough space to allocate unless we're allowed to use the reserve. */
2030                 return -1;
2031         }
2032
2033         if (dev->nErasedBlocks < dev->param.nReservedBlocks
2034                         && dev->allocationPage == 0) {
2035                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
2036         }
2037
2038         /* Next page please.... */
2039         if (dev->allocationBlock >= 0) {
2040                 bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
2041
2042                 retVal = (dev->allocationBlock * dev->param.nChunksPerBlock) +
2043                         dev->allocationPage;
2044                 bi->pagesInUse++;
2045                 yaffs_SetChunkBit(dev, dev->allocationBlock,
2046                                 dev->allocationPage);
2047
2048                 dev->allocationPage++;
2049
2050                 dev->nFreeChunks--;
2051
2052                 /* If the block is full set the state to full */
2053                 if (dev->allocationPage >= dev->param.nChunksPerBlock) {
2054                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2055                         dev->allocationBlock = -1;
2056                 }
2057
2058                 if (blockUsedPtr)
2059                         *blockUsedPtr = bi;
2060
2061                 return retVal;
2062         }
2063
2064         T(YAFFS_TRACE_ERROR,
2065                         (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
2066
2067         return -1;
2068 }
2069
2070 static int yaffs_GetErasedChunks(yaffs_Device *dev)
2071 {
2072         int n;
2073
2074         n = dev->nErasedBlocks * dev->param.nChunksPerBlock;
2075
2076         if (dev->allocationBlock > 0)
2077                 n += (dev->param.nChunksPerBlock - dev->allocationPage);
2078
2079         return n;
2080
2081 }
2082
2083 /*
2084  * yaffs_SkipRestOfBlock() skips over the rest of the allocation block
2085  * if we don't want to write to it.
2086  */
2087 void yaffs_SkipRestOfBlock(yaffs_Device *dev)
2088 {
2089         if(dev->allocationBlock > 0){
2090                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
2091                 if(bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING){
2092                         bi->blockState = YAFFS_BLOCK_STATE_FULL;
2093                         dev->allocationBlock = -1;
2094                 }
2095         }
2096 }
2097
2098
2099 static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
2100                 int wholeBlock)
2101 {
2102         int oldChunk;
2103         int newChunk;
2104         int markNAND;
2105         int retVal = YAFFS_OK;
2106         int i;
2107         int isCheckpointBlock;
2108         int matchingChunk;
2109         int maxCopies;
2110
2111         int chunksBefore = yaffs_GetErasedChunks(dev);
2112         int chunksAfter;
2113
2114         yaffs_ExtendedTags tags;
2115
2116         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
2117
2118         yaffs_Object *object;
2119
2120         isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
2121
2122
2123         T(YAFFS_TRACE_TRACING,
2124                         (TSTR("Collecting block %d, in use %d, shrink %d, wholeBlock %d" TENDSTR),
2125                          block,
2126                          bi->pagesInUse,
2127                          bi->hasShrinkHeader,
2128                          wholeBlock));
2129
2130         /*yaffs_VerifyFreeChunks(dev); */
2131
2132         if(bi->blockState == YAFFS_BLOCK_STATE_FULL)
2133                 bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
2134         
2135         bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
2136
2137         dev->gcDisable = 1;
2138
2139         if (isCheckpointBlock ||
2140                         !yaffs_StillSomeChunkBits(dev, block)) {
2141                 T(YAFFS_TRACE_TRACING,
2142                                 (TSTR
2143                                  ("Collecting block %d that has no chunks in use" TENDSTR),
2144                                  block));
2145                 yaffs_BlockBecameDirty(dev, block);
2146         } else {
2147
2148                 __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
2149
2150                 yaffs_VerifyBlock(dev, bi, block);
2151
2152                 maxCopies = (wholeBlock) ? dev->param.nChunksPerBlock : 5;
2153                 oldChunk = block * dev->param.nChunksPerBlock + dev->gcChunk;
2154
2155                 for (/* init already done */;
2156                      retVal == YAFFS_OK &&
2157                      dev->gcChunk < dev->param.nChunksPerBlock &&
2158                      (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) &&
2159                      maxCopies > 0;
2160                      dev->gcChunk++, oldChunk++) {
2161                         if (yaffs_CheckChunkBit(dev, block, dev->gcChunk)) {
2162
2163                                 /* This page is in use and might need to be copied off */
2164
2165                                 maxCopies--;
2166
2167                                 markNAND = 1;
2168
2169                                 yaffs_InitialiseTags(&tags);
2170
2171                                 yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
2172                                                                 buffer, &tags);
2173
2174                                 object =
2175                                     yaffs_FindObjectByNumber(dev,
2176                                                              tags.objectId);
2177
2178                                 T(YAFFS_TRACE_GC_DETAIL,
2179                                   (TSTR
2180                                    ("Collecting chunk in block %d, %d %d %d " TENDSTR),
2181                                    dev->gcChunk, tags.objectId, tags.chunkId,
2182                                    tags.byteCount));
2183
2184                                 if (object && !yaffs_SkipVerification(dev)) {
2185                                         if (tags.chunkId == 0)
2186                                                 matchingChunk = object->hdrChunk;
2187                                         else if (object->softDeleted)
2188                                                 matchingChunk = oldChunk; /* Defeat the test */
2189                                         else
2190                                                 matchingChunk = yaffs_FindChunkInFile(object, tags.chunkId, NULL);
2191
2192                                         if (oldChunk != matchingChunk)
2193                                                 T(YAFFS_TRACE_ERROR,
2194                                                   (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
2195                                                   oldChunk, matchingChunk, tags.objectId, tags.chunkId));
2196
2197                                 }
2198
2199                                 if (!object) {
2200                                         T(YAFFS_TRACE_ERROR,
2201                                           (TSTR
2202                                            ("page %d in gc has no object: %d %d %d "
2203                                             TENDSTR), oldChunk,
2204                                             tags.objectId, tags.chunkId, tags.byteCount));
2205                                 }
2206
2207                                 if (object &&
2208                                     object->deleted &&
2209                                     object->softDeleted &&
2210                                     tags.chunkId != 0) {
2211                                         /* Data chunk in a soft deleted file, throw it away
2212                                          * It's a soft deleted data chunk,
2213                                          * No need to copy this, just forget about it and
2214                                          * fix up the object.
2215                                          */
2216                                          
2217                                         /* Free chunks already includes softdeleted chunks.
2218                                          * How ever this chunk is going to soon be really deleted
2219                                          * which will increment free chunks.
2220                                          * We have to decrement free chunks so this works out properly.
2221                                          */
2222                                         dev->nFreeChunks--;
2223                                         bi->softDeletions--;
2224
2225                                         object->nDataChunks--;
2226
2227                                         if (object->nDataChunks <= 0) {
2228                                                 /* remeber to clean up the object */
2229                                                 dev->gcCleanupList[dev->nCleanups] =
2230                                                     tags.objectId;
2231                                                 dev->nCleanups++;
2232                                         }
2233                                         markNAND = 0;
2234                                 } else if (0) {
2235                                         /* Todo object && object->deleted && object->nDataChunks == 0 */
2236                                         /* Deleted object header with no data chunks.
2237                                          * Can be discarded and the file deleted.
2238                                          */
2239                                         object->hdrChunk = 0;
2240                                         yaffs_FreeTnode(object->myDev,
2241                                                         object->variant.
2242                                                         fileVariant.top);
2243                                         object->variant.fileVariant.top = NULL;
2244                                         yaffs_DoGenericObjectDeletion(object);
2245
2246                                 } else if (object) {
2247                                         /* It's either a data chunk in a live file or
2248                                          * an ObjectHeader, so we're interested in it.
2249                                          * NB Need to keep the ObjectHeaders of deleted files
2250                                          * until the whole file has been deleted off
2251                                          */
2252                                         tags.serialNumber++;
2253
2254                                         dev->nGCCopies++;
2255
2256                                         if (tags.chunkId == 0) {
2257                                                 /* It is an object Id,
2258                                                  * We need to nuke the shrinkheader flags first
2259                                                  * Also need to clean up shadowing.
2260                                                  * We no longer want the shrinkHeader flag since its work is done
2261                                                  * and if it is left in place it will mess up scanning.
2262                                                  */
2263
2264                                                 yaffs_ObjectHeader *oh;
2265                                                 oh = (yaffs_ObjectHeader *)buffer;
2266
2267                                                 oh->isShrink = 0;
2268                                                 tags.extraIsShrinkHeader = 0;
2269
2270                                                 oh->shadowsObject = 0;
2271                                                 oh->inbandShadowsObject = 0;
2272                                                 tags.extraShadows = 0;
2273
2274                                                 /* Update file size */
2275                                                 if(object->variantType == YAFFS_OBJECT_TYPE_FILE){
2276                                                         oh->fileSize = object->variant.fileVariant.fileSize;
2277                                                         tags.extraFileLength = oh->fileSize;
2278                                                 }
2279
2280                                                 yaffs_VerifyObjectHeader(object, oh, &tags, 1);
2281                                                 newChunk =
2282                                                     yaffs_WriteNewChunkWithTagsToNAND(dev,(__u8 *) oh, &tags, 1);
2283                                         } else
2284                                                 newChunk =
2285                                                     yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
2286
2287                                         if (newChunk < 0) {
2288                                                 retVal = YAFFS_FAIL;
2289                                         } else {
2290
2291                                                 /* Ok, now fix up the Tnodes etc. */
2292
2293                                                 if (tags.chunkId == 0) {
2294                                                         /* It's a header */
2295                                                         object->hdrChunk =  newChunk;
2296                                                         object->serial =   tags.serialNumber;
2297                                                 } else {
2298                                                         /* It's a data chunk */
2299                                                         int ok;
2300                                                         ok = yaffs_PutChunkIntoFile
2301                                                             (object,
2302                                                              tags.chunkId,
2303                                                              newChunk, 0);
2304                                                 }
2305                                         }
2306                                 }
2307
2308                                 if (retVal == YAFFS_OK)
2309                                         yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
2310
2311                         }
2312                 }
2313
2314                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
2315
2316
2317
2318         }
2319
2320         yaffs_VerifyCollectedBlock(dev, bi, block);
2321
2322
2323
2324         if (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
2325                 /*
2326                  * The gc did not complete. Set block state back to FULL
2327                  * because checkpointing does not restore gc.
2328                  */
2329                 bi->blockState = YAFFS_BLOCK_STATE_FULL;
2330         } else {
2331                 /* The gc completed. */
2332                 /* Do any required cleanups */
2333                 for (i = 0; i < dev->nCleanups; i++) {
2334                         /* Time to delete the file too */
2335                         object =
2336                             yaffs_FindObjectByNumber(dev,
2337                                                      dev->gcCleanupList[i]);
2338                         if (object) {
2339                                 yaffs_FreeTnode(dev,
2340                                                 object->variant.fileVariant.
2341                                                 top);
2342                                 object->variant.fileVariant.top = NULL;
2343                                 T(YAFFS_TRACE_GC,
2344                                   (TSTR
2345                                    ("yaffs: About to finally delete object %d"
2346                                     TENDSTR), object->objectId));
2347                                 yaffs_DoGenericObjectDeletion(object);
2348                                 object->myDev->nDeletedFiles--;
2349                         }
2350
2351                 }
2352
2353
2354                 chunksAfter = yaffs_GetErasedChunks(dev);
2355                 if (chunksBefore >= chunksAfter) {
2356                         T(YAFFS_TRACE_GC,
2357                           (TSTR
2358                            ("gc did not increase free chunks before %d after %d"
2359                             TENDSTR), chunksBefore, chunksAfter));
2360                 }
2361                 dev->gcBlock = 0;
2362                 dev->gcChunk = 0;
2363                 dev->nCleanups = 0;
2364         }
2365
2366         dev->gcDisable = 0;
2367
2368         return retVal;
2369 }
2370
2371 /*
2372  * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
2373  * for garbage collection.
2374  */
2375
2376 static unsigned yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
2377                                         int aggressive,
2378                                         int background)
2379 {
2380         int i;
2381         int iterations;
2382         unsigned selected = 0;
2383         int prioritised = 0;
2384         int prioritisedExists = 0;
2385         yaffs_BlockInfo *bi;
2386         int threshold;
2387
2388         /* First let's see if we need to grab a prioritised block */
2389         if (dev->hasPendingPrioritisedGCs && !aggressive) {
2390                 dev->gcDirtiest = 0;
2391                 bi = dev->blockInfo;
2392                 for (i = dev->internalStartBlock;
2393                         i <= dev->internalEndBlock && !selected;
2394                         i++) {
2395
2396                         if (bi->gcPrioritise) {
2397                                 prioritisedExists = 1;
2398                                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2399                                    yaffs2_BlockNotDisqualifiedFromGC(dev, bi)) {
2400                                         selected = i;
2401                                         prioritised = 1;
2402                                 }
2403                         }
2404                         bi++;
2405                 }
2406
2407                 /*
2408                  * If there is a prioritised block and none was selected then
2409                  * this happened because there is at least one old dirty block gumming
2410                  * up the works. Let's gc the oldest dirty block.
2411                  */
2412
2413                 if(prioritisedExists &&
2414                         !selected &&
2415                         dev->oldestDirtyBlock > 0)
2416                         selected = dev->oldestDirtyBlock;
2417
2418                 if (!prioritisedExists) /* None found, so we can clear this */
2419                         dev->hasPendingPrioritisedGCs = 0;
2420         }
2421
2422         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2423          * search harder.
2424          * else (we're doing a leasurely gc), then we only bother to do this if the
2425          * block has only a few pages in use.
2426          */
2427
2428         if (!selected){
2429                 int pagesUsed;
2430                 int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
2431                 if (aggressive){
2432                         threshold = dev->param.nChunksPerBlock;
2433                         iterations = nBlocks;
2434                 } else {
2435                         int maxThreshold;
2436
2437                         if(background)
2438                                 maxThreshold = dev->param.nChunksPerBlock/2;
2439                         else
2440                                 maxThreshold = dev->param.nChunksPerBlock/8;
2441
2442                         if(maxThreshold <  YAFFS_GC_PASSIVE_THRESHOLD)
2443                                 maxThreshold = YAFFS_GC_PASSIVE_THRESHOLD;
2444
2445                         threshold = background ?
2446                                 (dev->gcNotDone + 2) * 2 : 0;
2447                         if(threshold <YAFFS_GC_PASSIVE_THRESHOLD)
2448                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2449                         if(threshold > maxThreshold)
2450                                 threshold = maxThreshold;
2451
2452                         iterations = nBlocks / 16 + 1;
2453                         if (iterations > 100)
2454                                 iterations = 100;
2455                 }
2456
2457                 for (i = 0;
2458                         i < iterations &&
2459                         (dev->gcDirtiest < 1 ||
2460                                 dev->gcPagesInUse > YAFFS_GC_GOOD_ENOUGH);
2461                         i++) {
2462                         dev->gcBlockFinder++;
2463                         if (dev->gcBlockFinder < dev->internalStartBlock ||
2464                                 dev->gcBlockFinder > dev->internalEndBlock)
2465                                 dev->gcBlockFinder = dev->internalStartBlock;
2466
2467                         bi = yaffs_GetBlockInfo(dev, dev->gcBlockFinder);
2468
2469                         pagesUsed = bi->pagesInUse - bi->softDeletions;
2470
2471                         if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
2472                                 pagesUsed < dev->param.nChunksPerBlock &&
2473                                 (dev->gcDirtiest < 1 || pagesUsed < dev->gcPagesInUse) &&
2474                                 yaffs2_BlockNotDisqualifiedFromGC(dev, bi)) {
2475                                 dev->gcDirtiest = dev->gcBlockFinder;
2476                                 dev->gcPagesInUse = pagesUsed;
2477                         }
2478                 }
2479
2480                 if(dev->gcDirtiest > 0 && dev->gcPagesInUse <= threshold)
2481                         selected = dev->gcDirtiest;
2482         }
2483
2484         /*
2485          * If nothing has been selected for a while, try selecting the oldest dirty
2486          * because that's gumming up the works.
2487          */
2488
2489         if(!selected && dev->param.isYaffs2 &&
2490                 dev->gcNotDone >= ( background ? 10 : 20)){
2491                 yaffs2_FindOldestDirtySequence(dev);
2492                 if(dev->oldestDirtyBlock > 0) {
2493                         selected = dev->oldestDirtyBlock;
2494                         dev->gcDirtiest = selected;
2495                         dev->oldestDirtyGCs++;
2496                         bi = yaffs_GetBlockInfo(dev, selected);
2497                         dev->gcPagesInUse =  bi->pagesInUse - bi->softDeletions;
2498                 } else
2499                         dev->gcNotDone = 0;
2500         }
2501
2502         if(selected){
2503                 T(YAFFS_TRACE_GC,
2504                   (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR),
2505                   selected,
2506                   dev->param.nChunksPerBlock - dev->gcPagesInUse,
2507                   prioritised));
2508
2509                 dev->nGCBlocks++;
2510                 if(background)
2511                         dev->backgroundGCs++;
2512
2513                 dev->gcDirtiest = 0;
2514                 dev->gcPagesInUse = 0;
2515                 dev->gcNotDone = 0;
2516                 if(dev->refreshSkip > 0)
2517                         dev->refreshSkip--;
2518         } else{
2519                 dev->gcNotDone++;
2520                 T(YAFFS_TRACE_GC,
2521                   (TSTR("GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s" TENDSTR),
2522                   dev->gcBlockFinder, dev->gcNotDone,
2523                   threshold,
2524                   dev->gcDirtiest, dev->gcPagesInUse,
2525                   dev->oldestDirtyBlock,
2526                   background ? " bg" : ""));
2527         }
2528
2529         return selected;
2530 }
2531
2532 /* New garbage collector
2533  * If we're very low on erased blocks then we do aggressive garbage collection
2534  * otherwise we do "leasurely" garbage collection.
2535  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2536  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
2537  *
2538  * The idea is to help clear out space in a more spread-out manner.
2539  * Dunno if it really does anything useful.
2540  */
2541 static int yaffs_CheckGarbageCollection(yaffs_Device *dev, int background)
2542 {
2543         int aggressive = 0;
2544         int gcOk = YAFFS_OK;
2545         int maxTries = 0;
2546         int minErased;
2547         int erasedChunks;
2548         int checkpointBlockAdjust;
2549
2550         if(dev->param.gcControl &&
2551                 (dev->param.gcControl(dev) & 1) == 0)
2552                 return YAFFS_OK;
2553
2554         if (dev->gcDisable) {
2555                 /* Bail out so we don't get recursive gc */
2556                 return YAFFS_OK;
2557         }
2558
2559         /* This loop should pass the first time.
2560          * We'll only see looping here if the collection does not increase space.
2561          */
2562
2563         do {
2564                 maxTries++;
2565
2566                 checkpointBlockAdjust = yaffs2_CalcCheckpointBlocksRequired(dev);
2567
2568                 minErased  = dev->param.nReservedBlocks + checkpointBlockAdjust + 1;
2569                 erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
2570
2571                 /* If we need a block soon then do aggressive gc.*/
2572                 if (dev->nErasedBlocks < minErased)
2573                         aggressive = 1;
2574                 else {
2575                         if(!background && erasedChunks > (dev->nFreeChunks / 4))
2576                                 break;
2577
2578                         if(dev->gcSkip > 20)
2579                                 dev->gcSkip = 20;
2580                         if(erasedChunks < dev->nFreeChunks/2 ||
2581                                 dev->gcSkip < 1 ||
2582                                 background)
2583                                 aggressive = 0;
2584                         else {
2585                                 dev->gcSkip--;
2586                                 break;
2587                         }
2588                 }
2589
2590                 dev->gcSkip = 5;
2591
2592                 /* If we don't already have a block being gc'd then see if we should start another */
2593
2594                 if (dev->gcBlock < 1 && !aggressive) {
2595                         dev->gcBlock = yaffs2_FindRefreshBlock(dev);
2596                         dev->gcChunk = 0;
2597                         dev->nCleanups=0;
2598                 }
2599                 if (dev->gcBlock < 1) {
2600                         dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive, background);
2601                         dev->gcChunk = 0;
2602                         dev->nCleanups=0;
2603                 }
2604
2605                 if (dev->gcBlock > 0) {
2606                         dev->allGCs++;
2607                         if (!aggressive)
2608                                 dev->passiveGCs++;
2609
2610                         T(YAFFS_TRACE_GC,
2611                           (TSTR
2612                            ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
2613                            dev->nErasedBlocks, aggressive));
2614
2615                         gcOk = yaffs_GarbageCollectBlock(dev, dev->gcBlock, aggressive);
2616                 }
2617
2618                 if (dev->nErasedBlocks < (dev->param.nReservedBlocks) && dev->gcBlock > 0) {
2619                         T(YAFFS_TRACE_GC,
2620                           (TSTR
2621                            ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
2622                             TENDSTR), dev->nErasedBlocks, maxTries, dev->gcBlock));
2623                 }
2624         } while ((dev->nErasedBlocks < dev->param.nReservedBlocks) &&
2625                  (dev->gcBlock > 0) &&
2626                  (maxTries < 2));
2627
2628         return aggressive ? gcOk : YAFFS_OK;
2629 }
2630
2631 /*
2632  * yaffs_BackgroundGarbageCollect()
2633  * Garbage collects. Intended to be called from a background thread.
2634  * Returns non-zero if at least half the free chunks are erased.
2635  */
2636 int yaffs_BackgroundGarbageCollect(yaffs_Device *dev, unsigned urgency)
2637 {
2638         int erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
2639
2640         T(YAFFS_TRACE_BACKGROUND, (TSTR("Background gc %u" TENDSTR),urgency));
2641
2642         yaffs_CheckGarbageCollection(dev, 1);
2643         return erasedChunks > dev->nFreeChunks/2;
2644 }
2645
2646 /*-------------------------  TAGS --------------------------------*/
2647
2648 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
2649                            int chunkInObject)
2650 {
2651         return (tags->chunkId == chunkInObject &&
2652                 tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
2653
2654 }
2655
2656
2657 /*-------------------- Data file manipulation -----------------*/
2658
2659 static int yaffs_FindChunkInFile(yaffs_Object *in, int chunkInInode,
2660                                  yaffs_ExtendedTags *tags)
2661 {
2662         /*Get the Tnode, then get the level 0 offset chunk offset */
2663         yaffs_Tnode *tn;
2664         int theChunk = -1;
2665         yaffs_ExtendedTags localTags;
2666         int retVal = -1;
2667
2668         yaffs_Device *dev = in->myDev;
2669
2670         if (!tags) {
2671                 /* Passed a NULL, so use our own tags space */
2672                 tags = &localTags;
2673         }
2674
2675         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
2676
2677         if (tn) {
2678                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
2679
2680                 retVal =
2681                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
2682                                            chunkInInode);
2683         }
2684         return retVal;
2685 }
2686
2687 static int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in, int chunkInInode,
2688                                           yaffs_ExtendedTags *tags)
2689 {
2690         /* Get the Tnode, then get the level 0 offset chunk offset */
2691         yaffs_Tnode *tn;
2692         int theChunk = -1;
2693         yaffs_ExtendedTags localTags;
2694
2695         yaffs_Device *dev = in->myDev;
2696         int retVal = -1;
2697
2698         if (!tags) {
2699                 /* Passed a NULL, so use our own tags space */
2700                 tags = &localTags;
2701         }
2702
2703         tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
2704
2705         if (tn) {
2706
2707                 theChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
2708
2709                 retVal =
2710                     yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
2711                                            chunkInInode);
2712
2713                 /* Delete the entry in the filestructure (if found) */
2714                 if (retVal != -1)
2715                         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, 0);
2716         }
2717
2718         return retVal;
2719 }
2720
2721
2722 int yaffs_PutChunkIntoFile(yaffs_Object *in, int chunkInInode,
2723                                 int chunkInNAND, int inScan)
2724 {
2725         /* NB inScan is zero unless scanning.
2726          * For forward scanning, inScan is > 0;
2727          * for backward scanning inScan is < 0
2728          *
2729          * chunkInNAND = 0 is a dummy insert to make sure the tnodes are there.
2730          */
2731
2732         yaffs_Tnode *tn;
2733         yaffs_Device *dev = in->myDev;
2734         int existingChunk;
2735         yaffs_ExtendedTags existingTags;
2736         yaffs_ExtendedTags newTags;
2737         unsigned existingSerial, newSerial;
2738
2739         if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
2740                 /* Just ignore an attempt at putting a chunk into a non-file during scanning
2741                  * If it is not during Scanning then something went wrong!
2742                  */
2743                 if (!inScan) {
2744                         T(YAFFS_TRACE_ERROR,
2745                           (TSTR
2746                            ("yaffs tragedy:attempt to put data chunk into a non-file"
2747                             TENDSTR)));
2748                         YBUG();
2749                 }
2750
2751                 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
2752                 return YAFFS_OK;
2753         }
2754
2755         tn = yaffs_AddOrFindLevel0Tnode(dev,
2756                                         &in->variant.fileVariant,
2757                                         chunkInInode,
2758                                         NULL);
2759         if (!tn)
2760                 return YAFFS_FAIL;
2761         
2762         if(!chunkInNAND)
2763                 /* Dummy insert, bail now */
2764                 return YAFFS_OK;
2765
2766         existingChunk = yaffs_GetChunkGroupBase(dev, tn, chunkInInode);
2767
2768         if (inScan != 0) {
2769                 /* If we're scanning then we need to test for duplicates
2770                  * NB This does not need to be efficient since it should only ever
2771                  * happen when the power fails during a write, then only one
2772                  * chunk should ever be affected.
2773                  *
2774                  * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
2775                  * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
2776                  */
2777
2778                 if (existingChunk > 0) {
2779                         /* NB Right now existing chunk will not be real chunkId if the chunk group size > 1
2780                          *    thus we have to do a FindChunkInFile to get the real chunk id.
2781                          *
2782                          * We have a duplicate now we need to decide which one to use:
2783                          *
2784                          * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
2785                          * Forward scanning YAFFS2: The new one is what we use, dump the old one.
2786                          * YAFFS1: Get both sets of tags and compare serial numbers.
2787                          */
2788
2789                         if (inScan > 0) {
2790                                 /* Only do this for forward scanning */
2791                                 yaffs_ReadChunkWithTagsFromNAND(dev,
2792                                                                 chunkInNAND,
2793                                                                 NULL, &newTags);
2794
2795                                 /* Do a proper find */
2796                                 existingChunk =
2797                                     yaffs_FindChunkInFile(in, chunkInInode,
2798                                                           &existingTags);
2799                         }
2800
2801                         if (existingChunk <= 0) {
2802                                 /*Hoosterman - how did this happen? */
2803
2804                                 T(YAFFS_TRACE_ERROR,
2805                                   (TSTR
2806                                    ("yaffs tragedy: existing chunk < 0 in scan"
2807                                     TENDSTR)));
2808
2809                         }
2810
2811                         /* NB The deleted flags should be false, otherwise the chunks will
2812                          * not be loaded during a scan
2813                          */
2814
2815                         if (inScan > 0) {
2816                                 newSerial = newTags.serialNumber;
2817                                 existingSerial = existingTags.serialNumber;
2818                         }
2819
2820                         if ((inScan > 0) &&
2821                             (existingChunk <= 0 ||
2822                              ((existingSerial + 1) & 3) == newSerial)) {
2823                                 /* Forward scanning.
2824                                  * Use new
2825                                  * Delete the old one and drop through to update the tnode
2826                                  */
2827                                 yaffs_DeleteChunk(dev, existingChunk, 1,
2828                                                   __LINE__);
2829                         } else {
2830                                 /* Backward scanning or we want to use the existing one
2831                                  * Use existing.
2832                                  * Delete the new one and return early so that the tnode isn't changed
2833                                  */
2834                                 yaffs_DeleteChunk(dev, chunkInNAND, 1,
2835                                                   __LINE__);
2836                                 return YAFFS_OK;
2837                         }
2838                 }
2839
2840         }
2841
2842         if (existingChunk == 0)
2843                 in->nDataChunks++;
2844
2845         yaffs_LoadLevel0Tnode(dev, tn, chunkInInode, chunkInNAND);
2846
2847         return YAFFS_OK;
2848 }
2849
2850 static int yaffs_ReadChunkDataFromObject(yaffs_Object *in, int chunkInInode,
2851                                         __u8 *buffer)
2852 {
2853         int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);
2854
2855         if (chunkInNAND >= 0)
2856                 return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
2857                                                 buffer, NULL);
2858         else {
2859                 T(YAFFS_TRACE_NANDACCESS,
2860                   (TSTR("Chunk %d not found zero instead" TENDSTR),
2861                    chunkInNAND));
2862                 /* get sane (zero) data if you read a hole */
2863                 memset(buffer, 0, in->myDev->nDataBytesPerChunk);
2864                 return 0;
2865         }
2866
2867 }
2868
2869 void yaffs_DeleteChunk(yaffs_Device *dev, int chunkId, int markNAND, int lyn)
2870 {
2871         int block;
2872         int page;
2873         yaffs_ExtendedTags tags;
2874         yaffs_BlockInfo *bi;
2875
2876         if (chunkId <= 0)
2877                 return;
2878
2879         dev->nDeletions++;
2880         block = chunkId / dev->param.nChunksPerBlock;
2881         page = chunkId % dev->param.nChunksPerBlock;
2882
2883
2884         if (!yaffs_CheckChunkBit(dev, block, page))
2885                 T(YAFFS_TRACE_VERIFY,
2886                         (TSTR("Deleting invalid chunk %d"TENDSTR),
2887                          chunkId));
2888
2889         bi = yaffs_GetBlockInfo(dev, block);
2890         
2891         yaffs2_UpdateOldestDirtySequence(dev, block, bi);
2892
2893         T(YAFFS_TRACE_DELETION,
2894           (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
2895
2896         if (!dev->param.isYaffs2 && markNAND &&
2897             bi->blockState != YAFFS_BLOCK_STATE_COLLECTING) {
2898
2899                 yaffs_InitialiseTags(&tags);
2900
2901                 tags.chunkDeleted = 1;
2902
2903                 yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
2904                 yaffs_HandleUpdateChunk(dev, chunkId, &tags);
2905         } else {
2906                 dev->nUnmarkedDeletions++;
2907         }
2908
2909         /* Pull out of the management area.
2910          * If the whole block became dirty, this will kick off an erasure.
2911          */
2912         if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
2913             bi->blockState == YAFFS_BLOCK_STATE_FULL ||
2914             bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
2915             bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
2916                 dev->nFreeChunks++;
2917
2918                 yaffs_ClearChunkBit(dev, block, page);
2919
2920                 bi->pagesInUse--;
2921
2922                 if (bi->pagesInUse == 0 &&
2923                     !bi->hasShrinkHeader &&
2924                     bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
2925                     bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
2926                         yaffs_BlockBecameDirty(dev, block);
2927                 }
2928
2929         }
2930
2931 }
2932
2933 static int yaffs_WriteChunkDataToObject(yaffs_Object *in, int chunkInInode,
2934                                         const __u8 *buffer, int nBytes,
2935                                         int useReserve)
2936 {
2937         /* Find old chunk Need to do this to get serial number
2938          * Write new one and patch into tree.
2939          * Invalidate old tags.
2940          */
2941
2942         int prevChunkId;
2943         yaffs_ExtendedTags prevTags;
2944
2945         int newChunkId;
2946         yaffs_ExtendedTags newTags;
2947
2948         yaffs_Device *dev = in->myDev;
2949
2950         yaffs_CheckGarbageCollection(dev,0);
2951
2952         /* Get the previous chunk at this location in the file if it exists.
2953          * If it does not exist then put a zero into the tree. This creates
2954          * the tnode now, rather than later when it is harder to clean up.
2955          */
2956         prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);
2957         if(prevChunkId < 1 &&
2958                 !yaffs_PutChunkIntoFile(in, chunkInInode, 0, 0))
2959                 return 0;
2960
2961         /* Set up new tags */
2962         yaffs_InitialiseTags(&newTags);
2963
2964         newTags.chunkId = chunkInInode;
2965         newTags.objectId = in->objectId;
2966         newTags.serialNumber =
2967             (prevChunkId > 0) ? prevTags.serialNumber + 1 : 1;
2968         newTags.byteCount = nBytes;
2969
2970         if (nBytes < 1 || nBytes > dev->param.totalBytesPerChunk) {
2971                 T(YAFFS_TRACE_ERROR,
2972                 (TSTR("Writing %d bytes to chunk!!!!!!!!!" TENDSTR), nBytes));
2973                 YBUG();
2974         }
2975         
2976                 
2977         newChunkId =
2978             yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
2979                                               useReserve);
2980
2981         if (newChunkId > 0) {
2982                 yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);
2983
2984                 if (prevChunkId > 0)
2985                         yaffs_DeleteChunk(dev, prevChunkId, 1, __LINE__);
2986
2987                 yaffs_VerifyFileSanity(in);
2988         }
2989         return newChunkId;
2990
2991 }
2992
2993 /* UpdateObjectHeader updates the header on NAND for an object.
2994  * If name is not NULL, then that new name is used.
2995  */
2996 int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
2997                              int isShrink, int shadows, yaffs_XAttrMod *xmod)
2998 {
2999
3000         yaffs_BlockInfo *bi;
3001
3002         yaffs_Device *dev = in->myDev;
3003
3004         int prevChunkId;
3005         int retVal = 0;
3006         int result = 0;
3007
3008         int newChunkId;
3009         yaffs_ExtendedTags newTags;
3010         yaffs_ExtendedTags oldTags;
3011         const YCHAR *alias = NULL;
3012
3013         __u8 *buffer = NULL;
3014         YCHAR oldName[YAFFS_MAX_NAME_LENGTH + 1];
3015
3016         yaffs_ObjectHeader *oh = NULL;
3017
3018         yaffs_strcpy(oldName, _Y("silly old name"));
3019
3020
3021         if (!in->fake ||
3022                 in == dev->rootDir || /* The rootDir should also be saved */
3023                 force  || xmod) {
3024
3025                 yaffs_CheckGarbageCollection(dev,0);
3026                 yaffs_CheckObjectDetailsLoaded(in);
3027
3028                 buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
3029                 oh = (yaffs_ObjectHeader *) buffer;
3030
3031                 prevChunkId = in->hdrChunk;
3032
3033                 if (prevChunkId > 0) {
3034                         result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
3035                                                         buffer, &oldTags);
3036
3037                         yaffs_VerifyObjectHeader(in, oh, &oldTags, 0);
3038
3039                         memcpy(oldName, oh->name, sizeof(oh->name));
3040                         memset(buffer, 0xFF, sizeof(yaffs_ObjectHeader));
3041                 } else
3042                         memset(buffer, 0xFF, dev->nDataBytesPerChunk);
3043
3044                 oh->type = in->variantType;
3045                 oh->yst_mode = in->yst_mode;
3046                 oh->shadowsObject = oh->inbandShadowsObject = shadows;
3047
3048 #ifdef CONFIG_YAFFS_WINCE
3049                 oh->win_atime[0] = in->win_atime[0];
3050                 oh->win_ctime[0] = in->win_ctime[0];
3051                 oh->win_mtime[0] = in->win_mtime[0];
3052                 oh->win_atime[1] = in->win_atime[1];
3053                 oh->win_ctime[1] = in->win_ctime[1];
3054                 oh->win_mtime[1] = in->win_mtime[1];
3055 #else
3056                 oh->yst_uid = in->yst_uid;
3057                 oh->yst_gid = in->yst_gid;
3058                 oh->yst_atime = in->yst_atime;
3059                 oh->yst_mtime = in->yst_mtime;
3060                 oh->yst_ctime = in->yst_ctime;
3061                 oh->yst_rdev = in->yst_rdev;
3062 #endif
3063                 if (in->parent)
3064                         oh->parentObjectId = in->parent->objectId;
3065                 else
3066                         oh->parentObjectId = 0;
3067
3068                 if (name && *name) {
3069                         memset(oh->name, 0, sizeof(oh->name));
3070                         yaffs_LoadObjectHeaderFromName(dev,oh->name,name);
3071                 } else if (prevChunkId > 0)
3072                         memcpy(oh->name, oldName, sizeof(oh->name));
3073                 else
3074                         memset(oh->name, 0, sizeof(oh->name));
3075
3076                 oh->isShrink = isShrink;
3077
3078                 switch (in->variantType) {
3079                 case YAFFS_OBJECT_TYPE_UNKNOWN:
3080                         /* Should not happen */
3081                         break;
3082                 case YAFFS_OBJECT_TYPE_FILE:
3083                         oh->fileSize =
3084                             (oh->parentObjectId == YAFFS_OBJECTID_DELETED
3085                              || oh->parentObjectId ==
3086                              YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.
3087                             fileVariant.fileSize;
3088                         break;
3089                 case YAFFS_OBJECT_TYPE_HARDLINK:
3090                         oh->equivalentObjectId =
3091                             in->variant.hardLinkVariant.equivalentObjectId;
3092                         break;
3093                 case YAFFS_OBJECT_TYPE_SPECIAL:
3094                         /* Do nothing */
3095                         break;
3096                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3097                         /* Do nothing */
3098                         break;
3099                 case YAFFS_OBJECT_TYPE_SYMLINK:
3100                         alias = in->variant.symLinkVariant.alias;
3101                         if(!alias)
3102                                 alias = _Y("no alias");
3103                         yaffs_strncpy(oh->alias,
3104                                         alias,
3105                                       YAFFS_MAX_ALIAS_LENGTH);
3106                         oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3107                         break;
3108                 }
3109
3110                 /* process any xattrib modifications */
3111                 if(xmod)
3112                         yaffs_ApplyXMod(in, (char *)buffer, xmod);
3113
3114
3115                 /* Tags */
3116                 yaffs_InitialiseTags(&newTags);
3117                 in->serial++;
3118                 newTags.chunkId = 0;
3119                 newTags.objectId = in->objectId;
3120                 newTags.serialNumber = in->serial;
3121
3122                 /* Add extra info for file header */
3123
3124                 newTags.extraHeaderInfoAvailable = 1;
3125                 newTags.extraParentObjectId = oh->parentObjectId;
3126                 newTags.extraFileLength = oh->fileSize;
3127                 newTags.extraIsShrinkHeader = oh->isShrink;
3128                 newTags.extraEquivalentObjectId = oh->equivalentObjectId;
3129                 newTags.extraShadows = (oh->shadowsObject > 0) ? 1 : 0;
3130                 newTags.extraObjectType = in->variantType;
3131
3132                 yaffs_VerifyObjectHeader(in, oh, &newTags, 1);
3133
3134                 /* Create new chunk in NAND */
3135                 newChunkId =
3136                     yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
3137                                                       (prevChunkId > 0) ? 1 : 0);
3138
3139                 if (newChunkId >= 0) {
3140
3141                         in->hdrChunk = newChunkId;
3142
3143                         if (prevChunkId > 0) {
3144                                 yaffs_DeleteChunk(dev, prevChunkId, 1,
3145                                                   __LINE__);
3146                         }
3147
3148                         if (!yaffs_ObjectHasCachedWriteData(in))
3149                                 in->dirty = 0;
3150
3151                         /* If this was a shrink, then mark the block that the chunk lives on */
3152                         if (isShrink) {
3153                                 bi = yaffs_GetBlockInfo(in->myDev,
3154                                         newChunkId / in->myDev->param.nChunksPerBlock);
3155                                 bi->hasShrinkHeader = 1;
3156                         }
3157
3158                 }
3159
3160                 retVal = newChunkId;
3161
3162         }
3163
3164         if (buffer)
3165                 yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
3166
3167         return retVal;
3168 }
3169
3170 /*------------------------ Short Operations Cache ----------------------------------------
3171  *   In many situations where there is no high level buffering (eg WinCE) a lot of
3172  *   reads might be short sequential reads, and a lot of writes may be short
3173  *   sequential writes. eg. scanning/writing a jpeg file.
3174  *   In these cases, a short read/write cache can provide a huge perfomance benefit
3175  *   with dumb-as-a-rock code.
3176  *   In Linux, the page cache provides read buffering aand the short op cache provides write
3177  *   buffering.
3178  *
3179  *   There are a limited number (~10) of cache chunks per device so that we don't
3180  *   need a very intelligent search.
3181  */
3182
3183 static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj)
3184 {
3185         yaffs_Device *dev = obj->myDev;
3186         int i;
3187         yaffs_ChunkCache *cache;
3188         int nCaches = obj->myDev->param.nShortOpCaches;
3189
3190         for (i = 0; i < nCaches; i++) {
3191                 cache = &dev->srCache[i];
3192                 if (cache->object == obj &&
3193                     cache->dirty)
3194                         return 1;
3195         }
3196
3197         return 0;
3198 }
3199
3200
3201 static void yaffs_FlushFilesChunkCache(yaffs_Object *obj)
3202 {
3203         yaffs_Device *dev = obj->myDev;
3204         int lowest = -99;       /* Stop compiler whining. */
3205         int i;
3206         yaffs_ChunkCache *cache;
3207         int chunkWritten = 0;
3208         int nCaches = obj->myDev->param.nShortOpCaches;
3209
3210         if (nCaches > 0) {
3211                 do {
3212                         cache = NULL;
3213
3214                         /* Find the dirty cache for this object with the lowest chunk id. */
3215                         for (i = 0; i < nCaches; i++) {
3216                                 if (dev->srCache[i].object == obj &&
3217                                     dev->srCache[i].dirty) {
3218                                         if (!cache
3219                                             || dev->srCache[i].chunkId <
3220                                             lowest) {
3221                                                 cache = &dev->srCache[i];
3222                                                 lowest = cache->chunkId;
3223                                         }
3224                                 }
3225                         }
3226
3227                         if (cache && !cache->locked) {
3228                                 /* Write it out and free it up */
3229
3230                                 chunkWritten =
3231                                     yaffs_WriteChunkDataToObject(cache->object,
3232                                                                  cache->chunkId,
3233                                                                  cache->data,
3234                                                                  cache->nBytes,
3235                                                                  1);
3236                                 cache->dirty = 0;
3237                                 cache->object = NULL;
3238                         }
3239
3240                 } while (cache && chunkWritten > 0);
3241
3242                 if (cache) {
3243                         /* Hoosterman, disk full while writing cache out. */
3244                         T(YAFFS_TRACE_ERROR,
3245                           (TSTR("yaffs tragedy: no space during cache write" TENDSTR)));
3246
3247                 }
3248         }
3249
3250 }
3251
3252 /*yaffs_FlushEntireDeviceCache(dev)
3253  *
3254  *
3255  */
3256
3257 void yaffs_FlushEntireDeviceCache(yaffs_Device *dev)
3258 {
3259         yaffs_Object *obj;
3260         int nCaches = dev->param.nShortOpCaches;
3261         int i;
3262
3263         /* Find a dirty object in the cache and flush it...
3264          * until there are no further dirty objects.
3265          */
3266         do {
3267                 obj = NULL;
3268                 for (i = 0; i < nCaches && !obj; i++) {
3269                         if (dev->srCache[i].object &&
3270                             dev->srCache[i].dirty)
3271                                 obj = dev->srCache[i].object;
3272
3273                 }
3274                 if (obj)
3275                         yaffs_FlushFilesChunkCache(obj);
3276
3277         } while (obj);
3278
3279 }
3280
3281
3282 /* Grab us a cache chunk for use.
3283  * First look for an empty one.
3284  * Then look for the least recently used non-dirty one.
3285  * Then look for the least recently used dirty one...., flush and look again.
3286  */
3287 static yaffs_ChunkCache *yaffs_GrabChunkCacheWorker(yaffs_Device *dev)
3288 {
3289         int i;
3290
3291         if (dev->param.nShortOpCaches > 0) {
3292                 for (i = 0; i < dev->param.nShortOpCaches; i++) {
3293                         if (!dev->srCache[i].object)
3294                                 return &dev->srCache[i];
3295                 }
3296         }
3297
3298         return NULL;
3299 }
3300
3301 static yaffs_ChunkCache *yaffs_GrabChunkCache(yaffs_Device *dev)
3302 {
3303         yaffs_ChunkCache *cache;
3304         yaffs_Object *theObj;
3305         int usage;
3306         int i;
3307         int pushout;
3308
3309         if (dev->param.nShortOpCaches > 0) {
3310                 /* Try find a non-dirty one... */
3311
3312                 cache = yaffs_GrabChunkCacheWorker(dev);
3313
3314                 if (!cache) {
3315                         /* They were all dirty, find the last recently used object and flush
3316                          * its cache, then  find again.
3317                          * NB what's here is not very accurate, we actually flush the object
3318                          * the last recently used page.
3319                          */
3320
3321                         /* With locking we can't assume we can use entry zero */
3322
3323                         theObj = NULL;
3324                         usage = -1;
3325                         cache = NULL;
3326                         pushout = -1;
3327
3328                         for (i = 0; i < dev->param.nShortOpCaches; i++) {
3329                                 if (dev->srCache[i].object &&
3330                                     !dev->srCache[i].locked &&
3331                                     (dev->srCache[i].lastUse < usage || !cache)) {
3332                                         usage = dev->srCache[i].lastUse;
3333                                         theObj = dev->srCache[i].object;
3334                                         cache = &dev->srCache[i];
3335                                         pushout = i;
3336                                 }
3337                         }
3338
3339                         if (!cache || cache->dirty) {
3340                                 /* Flush and try again */
3341                                 yaffs_FlushFilesChunkCache(theObj);
3342                                 cache = yaffs_GrabChunkCacheWorker(dev);
3343                         }
3344
3345                 }
3346                 return cache;
3347         } else
3348                 return NULL;
3349
3350 }
3351
3352 /* Find a cached chunk */
3353 static yaffs_ChunkCache *yaffs_FindChunkCache(const yaffs_Object *obj,
3354                                               int chunkId)
3355 {
3356         yaffs_Device *dev = obj->myDev;
3357         int i;
3358         if (dev->param.nShortOpCaches > 0) {
3359                 for (i = 0; i < dev->param.nShortOpCaches; i++) {
3360                         if (dev->srCache[i].object == obj &&
3361                             dev->srCache[i].chunkId == chunkId) {
3362                                 dev->cacheHits++;
3363
3364                                 return &dev->srCache[i];
3365                         }
3366                 }
3367         }
3368         return NULL;
3369 }
3370
3371 /* Mark the chunk for the least recently used algorithym */
3372 static void yaffs_UseChunkCache(yaffs_Device *dev, yaffs_ChunkCache *cache,
3373                                 int isAWrite)
3374 {
3375
3376         if (dev->param.nShortOpCaches > 0) {
3377                 if (dev->srLastUse < 0 || dev->srLastUse > 100000000) {
3378                         /* Reset the cache usages */
3379                         int i;
3380                         for (i = 1; i < dev->param.nShortOpCaches; i++)
3381                                 dev->srCache[i].lastUse = 0;
3382
3383                         dev->srLastUse = 0;
3384                 }
3385
3386                 dev->srLastUse++;
3387
3388                 cache->lastUse = dev->srLastUse;
3389
3390                 if (isAWrite)
3391                         cache->dirty = 1;
3392         }
3393 }
3394
3395 /* Invalidate a single cache page.
3396  * Do this when a whole page gets written,
3397  * ie the short cache for this page is no longer valid.
3398  */
3399 static void yaffs_InvalidateChunkCache(yaffs_Object *object, int chunkId)
3400 {
3401         if (object->myDev->param.nShortOpCaches > 0) {
3402                 yaffs_ChunkCache *cache = yaffs_FindChunkCache(object, chunkId);
3403
3404                 if (cache)
3405                         cache->object = NULL;
3406         }
3407 }
3408
3409 /* Invalidate all the cache pages associated with this object
3410  * Do this whenever ther file is deleted or resized.
3411  */
3412 static void yaffs_InvalidateWholeChunkCache(yaffs_Object *in)
3413 {
3414         int i;
3415         yaffs_Device *dev = in->myDev;
3416
3417         if (dev->param.nShortOpCaches > 0) {
3418                 /* Invalidate it. */
3419                 for (i = 0; i < dev->param.nShortOpCaches; i++) {
3420                         if (dev->srCache[i].object == in)
3421                                 dev->srCache[i].object = NULL;
3422                 }
3423         }
3424 }
3425
3426
3427 /*--------------------- File read/write ------------------------
3428  * Read and write have very similar structures.
3429  * In general the read/write has three parts to it
3430  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3431  * Some complete chunks
3432  * An incomplete chunk to end off with
3433  *
3434  * Curve-balls: the first chunk might also be the last chunk.
3435  */
3436
3437 int yaffs_ReadDataFromFile(yaffs_Object *in, __u8 *buffer, loff_t offset,
3438                         int nBytes)
3439 {
3440
3441         int chunk;
3442         __u32 start;
3443         int nToCopy;
3444         int n = nBytes;
3445         int nDone = 0;
3446         yaffs_ChunkCache *cache;
3447
3448         yaffs_Device *dev;
3449
3450         dev = in->myDev;
3451
3452         while (n > 0) {
3453                 /* chunk = offset / dev->nDataBytesPerChunk + 1; */
3454                 /* start = offset % dev->nDataBytesPerChunk; */
3455                 yaffs_AddrToChunk(dev, offset, &chunk, &start);
3456                 chunk++;
3457
3458                 /* OK now check for the curveball where the start and end are in
3459                  * the same chunk.
3460                  */
3461                 if ((start + n) < dev->nDataBytesPerChunk)
3462                         nToCopy = n;
3463                 else
3464                         nToCopy = dev->nDataBytesPerChunk - start;
3465
3466                 cache = yaffs_FindChunkCache(in, chunk);
3467
3468                 /* If the chunk is already in the cache or it is less than a whole chunk
3469                  * or we're using inband tags then use the cache (if there is caching)
3470                  * else bypass the cache.
3471                  */
3472                 if (cache || nToCopy != dev->nDataBytesPerChunk || dev->param.inbandTags) {
3473                         if (dev->param.nShortOpCaches > 0) {
3474
3475                                 /* If we can't find the data in the cache, then load it up. */
3476
3477                                 if (!cache) {
3478                                         cache = yaffs_GrabChunkCache(in->myDev);
3479                                         cache->object = in;
3480                                         cache->chunkId = chunk;
3481                                         cache->dirty = 0;
3482                                         cache->locked = 0;
3483                                         yaffs_ReadChunkDataFromObject(in, chunk,
3484                                                                       cache->
3485                                                                       data);
3486                                         cache->nBytes = 0;
3487                                 }
3488
3489                                 yaffs_UseChunkCache(dev, cache, 0);
3490
3491                                 cache->locked = 1;
3492
3493
3494                                 memcpy(buffer, &cache->data[start], nToCopy);
3495
3496                                 cache->locked = 0;
3497                         } else {
3498                                 /* Read into the local buffer then copy..*/
3499
3500                                 __u8 *localBuffer =
3501                                     yaffs_GetTempBuffer(dev, __LINE__);
3502                                 yaffs_ReadChunkDataFromObject(in, chunk,
3503                                                               localBuffer);
3504
3505                                 memcpy(buffer, &localBuffer[start], nToCopy);
3506
3507
3508                                 yaffs_ReleaseTempBuffer(dev, localBuffer,
3509                                                         __LINE__);
3510                         }
3511
3512                 } else {
3513
3514                         /* A full chunk. Read directly into the supplied buffer. */
3515                         yaffs_ReadChunkDataFromObject(in, chunk, buffer);
3516
3517                 }
3518
3519                 n -= nToCopy;
3520                 offset += nToCopy;
3521                 buffer += nToCopy;
3522                 nDone += nToCopy;
3523
3524         }
3525
3526         return nDone;
3527 }
3528
3529 int yaffs_DoWriteDataToFile(yaffs_Object *in, const __u8 *buffer, loff_t offset,
3530                         int nBytes, int writeThrough)
3531 {
3532
3533         int chunk;
3534         __u32 start;
3535         int nToCopy;
3536         int n = nBytes;
3537         int nDone = 0;
3538         int nToWriteBack;
3539         int startOfWrite = offset;
3540         int chunkWritten = 0;
3541         __u32 nBytesRead;
3542         __u32 chunkStart;
3543
3544         yaffs_Device *dev;
3545
3546         dev = in->myDev;
3547
3548         while (n > 0 && chunkWritten >= 0) {
3549                 yaffs_AddrToChunk(dev, offset, &chunk, &start);
3550
3551                 if (chunk * dev->nDataBytesPerChunk + start != offset ||
3552                                 start >= dev->nDataBytesPerChunk) {
3553                         T(YAFFS_TRACE_ERROR, (
3554                            TSTR("AddrToChunk of offset %d gives chunk %d start %d"
3555                            TENDSTR),
3556                            (int)offset, chunk, start));
3557                 }
3558                 chunk++; /* File pos to chunk in file offset */
3559
3560                 /* OK now check for the curveball where the start and end are in
3561                  * the same chunk.
3562                  */
3563
3564                 if ((start + n) < dev->nDataBytesPerChunk) {
3565                         nToCopy = n;
3566
3567                         /* Now folks, to calculate how many bytes to write back....
3568                          * If we're overwriting and not writing to then end of file then
3569                          * we need to write back as much as was there before.
3570                          */
3571
3572                         chunkStart = ((chunk - 1) * dev->nDataBytesPerChunk);
3573
3574                         if (chunkStart > in->variant.fileVariant.fileSize)
3575                                 nBytesRead = 0; /* Past end of file */
3576                         else
3577                                 nBytesRead = in->variant.fileVariant.fileSize - chunkStart;
3578
3579                         if (nBytesRead > dev->nDataBytesPerChunk)
3580                                 nBytesRead = dev->nDataBytesPerChunk;
3581
3582                         nToWriteBack =
3583                             (nBytesRead >
3584                              (start + n)) ? nBytesRead : (start + n);
3585
3586                         if (nToWriteBack < 0 || nToWriteBack > dev->nDataBytesPerChunk)
3587                                 YBUG();
3588
3589                 } else {
3590                         nToCopy = dev->nDataBytesPerChunk - start;
3591                         nToWriteBack = dev->nDataBytesPerChunk;
3592                 }
3593
3594                 if (nToCopy != dev->nDataBytesPerChunk || dev->param.inbandTags) {
3595                         /* An incomplete start or end chunk (or maybe both start and end chunk),
3596                          * or we're using inband tags, so we want to use the cache buffers.
3597                          */
3598                         if (dev->param.nShortOpCaches > 0) {
3599                                 yaffs_ChunkCache *cache;
3600                                 /* If we can't find the data in the cache, then load the cache */
3601                                 cache = yaffs_FindChunkCache(in, chunk);
3602
3603                                 if (!cache
3604                                     && yaffs_CheckSpaceForAllocation(dev, 1)) {
3605                                         cache = yaffs_GrabChunkCache(dev);
3606                                         cache->object = in;
3607                                         cache->chunkId = chunk;
3608                                         cache->dirty = 0;
3609                                         cache->locked = 0;
3610                                         yaffs_ReadChunkDataFromObject(in, chunk,
3611                                                                       cache->data);
3612                                 } else if (cache &&
3613                                         !cache->dirty &&
3614                                         !yaffs_CheckSpaceForAllocation(dev, 1)) {
3615                                         /* Drop the cache if it was a read cache item and
3616                                          * no space check has been made for it.
3617                                          */
3618                                          cache = NULL;
3619                                 }
3620
3621                                 if (cache) {
3622                                         yaffs_UseChunkCache(dev, cache, 1);
3623                                         cache->locked = 1;
3624
3625
3626                                         memcpy(&cache->data[start], buffer,
3627                                                nToCopy);
3628
3629
3630                                         cache->locked = 0;
3631                                         cache->nBytes = nToWriteBack;
3632
3633                                         if (writeThrough) {
3634                                                 chunkWritten =
3635                                                     yaffs_WriteChunkDataToObject
3636                                                     (cache->object,
3637                                                      cache->chunkId,
3638                                                      cache->data, cache->nBytes,
3639                                                      1);
3640                                                 cache->dirty = 0;
3641                                         }
3642
3643                                 } else {
3644                                         chunkWritten = -1;      /* fail the write */
3645                                 }
3646                         } else {
3647                                 /* An incomplete start or end chunk (or maybe both start and end chunk)
3648                                  * Read into the local buffer then copy, then copy over and write back.
3649                                  */
3650
3651                                 __u8 *localBuffer =
3652                                     yaffs_GetTempBuffer(dev, __LINE__);
3653
3654                                 yaffs_ReadChunkDataFromObject(in, chunk,
3655                                                               localBuffer);
3656
3657
3658
3659                                 memcpy(&localBuffer[start], buffer, nToCopy);
3660
3661                                 chunkWritten =
3662                                     yaffs_WriteChunkDataToObject(in, chunk,
3663                                                                  localBuffer,
3664                                                                  nToWriteBack,
3665                                                                  0);
3666
3667                                 yaffs_ReleaseTempBuffer(dev, localBuffer,
3668                                                         __LINE__);
3669
3670                         }
3671
3672                 } else {
3673                         /* A full chunk. Write directly from the supplied buffer. */
3674
3675
3676
3677                         chunkWritten =
3678                             yaffs_WriteChunkDataToObject(in, chunk, buffer,
3679                                                          dev->nDataBytesPerChunk,
3680                                                          0);
3681
3682                         /* Since we've overwritten the cached data, we better invalidate it. */
3683                         yaffs_InvalidateChunkCache(in, chunk);
3684                 }
3685
3686                 if (chunkWritten >= 0) {
3687                         n -= nToCopy;
3688                         offset += nToCopy;
3689                         buffer += nToCopy;
3690                         nDone += nToCopy;
3691                 }
3692
3693         }
3694
3695         /* Update file object */
3696
3697         if ((startOfWrite + nDone) > in->variant.fileVariant.fileSize)
3698                 in->variant.fileVariant.fileSize = (startOfWrite + nDone);
3699
3700         in->dirty = 1;
3701
3702         return nDone;
3703 }
3704
3705 int yaffs_WriteDataToFile(yaffs_Object *in, const __u8 *buffer, loff_t offset,
3706                         int nBytes, int writeThrough)
3707 {
3708         yaffs2_HandleHole(in,offset);
3709         return yaffs_DoWriteDataToFile(in,buffer,offset,nBytes,writeThrough);
3710 }
3711
3712
3713
3714 /* ---------------------- File resizing stuff ------------------ */
3715
3716 static void yaffs_PruneResizedChunks(yaffs_Object *in, int newSize)
3717 {
3718
3719         yaffs_Device *dev = in->myDev;
3720         int oldFileSize = in->variant.fileVariant.fileSize;
3721
3722         int lastDel = 1 + (oldFileSize - 1) / dev->nDataBytesPerChunk;
3723
3724         int startDel = 1 + (newSize + dev->nDataBytesPerChunk - 1) /
3725             dev->nDataBytesPerChunk;
3726         int i;
3727         int chunkId;
3728
3729         /* Delete backwards so that we don't end up with holes if
3730          * power is lost part-way through the operation.
3731          */
3732         for (i = lastDel; i >= startDel; i--) {
3733                 /* NB this could be optimised somewhat,
3734                  * eg. could retrieve the tags and write them without
3735                  * using yaffs_DeleteChunk
3736                  */
3737
3738                 chunkId = yaffs_FindAndDeleteChunkInFile(in, i, NULL);
3739                 if (chunkId > 0) {
3740                         if (chunkId <
3741                             (dev->internalStartBlock * dev->param.nChunksPerBlock)
3742                             || chunkId >=
3743                             ((dev->internalEndBlock +
3744                               1) * dev->param.nChunksPerBlock)) {
3745                                 T(YAFFS_TRACE_ALWAYS,
3746                                   (TSTR("Found daft chunkId %d for %d" TENDSTR),
3747                                    chunkId, i));
3748                         } else {
3749                                 in->nDataChunks--;
3750                                 yaffs_DeleteChunk(dev, chunkId, 1, __LINE__);
3751                         }
3752                 }
3753         }
3754
3755 }
3756
3757
3758 void yaffs_ResizeDown( yaffs_Object *obj, loff_t newSize)
3759 {
3760         int newFullChunks;
3761         __u32 newSizeOfPartialChunk;
3762         yaffs_Device *dev = obj->myDev;
3763
3764         yaffs_AddrToChunk(dev, newSize, &newFullChunks, &newSizeOfPartialChunk);
3765
3766         yaffs_PruneResizedChunks(obj, newSize);
3767
3768         if (newSizeOfPartialChunk != 0) {
3769                 int lastChunk = 1 + newFullChunks;
3770                 __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
3771
3772                 /* Got to read and rewrite the last chunk with its new size and zero pad */
3773                 yaffs_ReadChunkDataFromObject(obj, lastChunk, localBuffer);
3774                 memset(localBuffer + newSizeOfPartialChunk, 0,
3775                         dev->nDataBytesPerChunk - newSizeOfPartialChunk);
3776
3777                 yaffs_WriteChunkDataToObject(obj