yaffs large file support: Fix max file size issue that prevented the scanning working.
[yaffs2.git] / yaffs_guts.c
1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2011 Aleph One Ltd.
5  *   for Toby Churchill Ltd and Brightstar Engineering
6  *
7  * Created by Charles Manning <charles@aleph1.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 #include "yportenv.h"
15 #include "yaffs_trace.h"
16
17 #include "yaffs_guts.h"
18 #include "yaffs_getblockinfo.h"
19 #include "yaffs_tagscompat.h"
20 #include "yaffs_nand.h"
21 #include "yaffs_yaffs1.h"
22 #include "yaffs_yaffs2.h"
23 #include "yaffs_bitmap.h"
24 #include "yaffs_verify.h"
25 #include "yaffs_nand.h"
26 #include "yaffs_packedtags2.h"
27 #include "yaffs_nameval.h"
28 #include "yaffs_allocator.h"
29 #include "yaffs_attribs.h"
30 #include "yaffs_summary.h"
31
32 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
33 #define YAFFS_GC_GOOD_ENOUGH 2
34 #define YAFFS_GC_PASSIVE_THRESHOLD 4
35
36 #include "yaffs_ecc.h"
37
38 /* Forward declarations */
39
40 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
41                              const u8 *buffer, int n_bytes, int use_reserve);
42
43
44
45 /* Function to calculate chunk and offset */
46
47 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
48                                 int *chunk_out, u32 *offset_out)
49 {
50         int chunk;
51         u32 offset;
52
53         chunk = (u32) (addr >> dev->chunk_shift);
54
55         if (dev->chunk_div == 1) {
56                 /* easy power of 2 case */
57                 offset = (u32) (addr & dev->chunk_mask);
58         } else {
59                 /* Non power-of-2 case */
60
61                 loff_t chunk_base;
62
63                 chunk /= dev->chunk_div;
64
65                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
66                 offset = (u32) (addr - chunk_base);
67         }
68
69         *chunk_out = chunk;
70         *offset_out = offset;
71 }
72
73 /* Function to return the number of shifts for a power of 2 greater than or
74  * equal to the given number
75  * Note we don't try to cater for all possible numbers and this does not have to
76  * be hellishly efficient.
77  */
78
79 static inline u32 calc_shifts_ceiling(u32 x)
80 {
81         int extra_bits;
82         int shifts;
83
84         shifts = extra_bits = 0;
85
86         while (x > 1) {
87                 if (x & 1)
88                         extra_bits++;
89                 x >>= 1;
90                 shifts++;
91         }
92
93         if (extra_bits)
94                 shifts++;
95
96         return shifts;
97 }
98
99 /* Function to return the number of shifts to get a 1 in bit 0
100  */
101
102 static inline u32 calc_shifts(u32 x)
103 {
104         u32 shifts;
105
106         shifts = 0;
107
108         if (!x)
109                 return 0;
110
111         while (!(x & 1)) {
112                 x >>= 1;
113                 shifts++;
114         }
115
116         return shifts;
117 }
118
119 /*
120  * Temporary buffer manipulations.
121  */
122
123 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
124 {
125         int i;
126         u8 *buf = (u8 *) 1;
127
128         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
129
130         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
131                 dev->temp_buffer[i].in_use = 0;
132                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
133                 dev->temp_buffer[i].buffer = buf;
134         }
135
136         return buf ? YAFFS_OK : YAFFS_FAIL;
137 }
138
139 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
140 {
141         int i;
142
143         dev->temp_in_use++;
144         if (dev->temp_in_use > dev->max_temp)
145                 dev->max_temp = dev->temp_in_use;
146
147         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
148                 if (dev->temp_buffer[i].in_use == 0) {
149                         dev->temp_buffer[i].in_use = 1;
150                         return dev->temp_buffer[i].buffer;
151                 }
152         }
153
154         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
155         /*
156          * If we got here then we have to allocate an unmanaged one
157          * This is not good.
158          */
159
160         dev->unmanaged_buffer_allocs++;
161         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
162
163 }
164
165 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
166 {
167         int i;
168
169         dev->temp_in_use--;
170
171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
172                 if (dev->temp_buffer[i].buffer == buffer) {
173                         dev->temp_buffer[i].in_use = 0;
174                         return;
175                 }
176         }
177
178         if (buffer) {
179                 /* assume it is an unmanaged one. */
180                 yaffs_trace(YAFFS_TRACE_BUFFERS, "Releasing unmanaged temp buffer");
181                 kfree(buffer);
182                 dev->unmanaged_buffer_deallocs++;
183         }
184
185 }
186
187 /*
188  * Determine if we have a managed buffer.
189  */
190 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
191 {
192         int i;
193
194         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
195                 if (dev->temp_buffer[i].buffer == buffer)
196                         return 1;
197         }
198
199         for (i = 0; i < dev->param.n_caches; i++) {
200                 if (dev->cache[i].data == buffer)
201                         return 1;
202         }
203
204         if (buffer == dev->checkpt_buffer)
205                 return 1;
206
207         yaffs_trace(YAFFS_TRACE_ALWAYS,
208           "yaffs: unmaged buffer detected.");
209         return 0;
210 }
211
212 /*
213  * Functions for robustisizing TODO
214  *
215  */
216
217 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
218                                      const u8 *data,
219                                      const struct yaffs_ext_tags *tags)
220 {
221         dev = dev;
222         nand_chunk = nand_chunk;
223         data = data;
224         tags = tags;
225 }
226
227 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
228                                       const struct yaffs_ext_tags *tags)
229 {
230         dev = dev;
231         nand_chunk = nand_chunk;
232         tags = tags;
233 }
234
235 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
236                               struct yaffs_block_info *bi)
237 {
238         if (!bi->gc_prioritise) {
239                 bi->gc_prioritise = 1;
240                 dev->has_pending_prioritised_gc = 1;
241                 bi->chunk_error_strikes++;
242
243                 if (bi->chunk_error_strikes > 3) {
244                         bi->needs_retiring = 1; /* Too many stikes, so retire */
245                         yaffs_trace(YAFFS_TRACE_ALWAYS,
246                                 "yaffs: Block struck out");
247
248                 }
249         }
250 }
251
252 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
253                                         int erased_ok)
254 {
255         int flash_block = nand_chunk / dev->param.chunks_per_block;
256         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
257
258         yaffs_handle_chunk_error(dev, bi);
259
260         if (erased_ok) {
261                 /* Was an actual write failure,
262                  * so mark the block for retirement.*/
263                 bi->needs_retiring = 1;
264                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
265                   "**>> Block %d needs retiring", flash_block);
266         }
267
268         /* Delete the chunk */
269         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
270         yaffs_skip_rest_of_block(dev);
271 }
272
273 /*
274  * Verification code
275  */
276
277 /*
278  *  Simple hash function. Needs to have a reasonable spread
279  */
280
281 static inline int yaffs_hash_fn(int n)
282 {
283         n = abs(n);
284         return n % YAFFS_NOBJECT_BUCKETS;
285 }
286
287 /*
288  * Access functions to useful fake objects.
289  * Note that root might have a presence in NAND if permissions are set.
290  */
291
292 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
293 {
294         return dev->root_dir;
295 }
296
297 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
298 {
299         return dev->lost_n_found;
300 }
301
302 /*
303  *  Erased NAND checking functions
304  */
305
306 int yaffs_check_ff(u8 *buffer, int n_bytes)
307 {
308         /* Horrible, slow implementation */
309         while (n_bytes--) {
310                 if (*buffer != 0xff)
311                         return 0;
312                 buffer++;
313         }
314         return 1;
315 }
316
317 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
318 {
319         int retval = YAFFS_OK;
320         u8 *data = yaffs_get_temp_buffer(dev);
321         struct yaffs_ext_tags tags;
322         int result;
323
324         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
325
326         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
327                 retval = YAFFS_FAIL;
328
329         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
330                 tags.chunk_used) {
331                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
332                         "Chunk %d not erased", nand_chunk);
333                 retval = YAFFS_FAIL;
334         }
335
336         yaffs_release_temp_buffer(dev, data);
337
338         return retval;
339
340 }
341
342 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
343                                       int nand_chunk,
344                                       const u8 *data,
345                                       struct yaffs_ext_tags *tags)
346 {
347         int retval = YAFFS_OK;
348         struct yaffs_ext_tags temp_tags;
349         u8 *buffer = yaffs_get_temp_buffer(dev);
350         int result;
351
352         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
353         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
354             temp_tags.obj_id != tags->obj_id ||
355             temp_tags.chunk_id != tags->chunk_id ||
356             temp_tags.n_bytes != tags->n_bytes)
357                 retval = YAFFS_FAIL;
358
359         yaffs_release_temp_buffer(dev, buffer);
360
361         return retval;
362 }
363
364
365 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
366 {
367         int reserved_chunks;
368         int reserved_blocks = dev->param.n_reserved_blocks;
369         int checkpt_blocks;
370
371         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
372
373         reserved_chunks =
374             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
375
376         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
377 }
378
379 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
380 {
381         int i;
382         struct yaffs_block_info *bi;
383
384         if (dev->n_erased_blocks < 1) {
385                 /* Hoosterman we've got a problem.
386                  * Can't get space to gc
387                  */
388                 yaffs_trace(YAFFS_TRACE_ERROR,
389                   "yaffs tragedy: no more erased blocks");
390
391                 return -1;
392         }
393
394         /* Find an empty block. */
395
396         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
397                 dev->alloc_block_finder++;
398                 if (dev->alloc_block_finder < dev->internal_start_block
399                     || dev->alloc_block_finder > dev->internal_end_block) {
400                         dev->alloc_block_finder = dev->internal_start_block;
401                 }
402
403                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
404
405                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
406                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
407                         dev->seq_number++;
408                         bi->seq_number = dev->seq_number;
409                         dev->n_erased_blocks--;
410                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
411                           "Allocated block %d, seq  %d, %d left" ,
412                            dev->alloc_block_finder, dev->seq_number,
413                            dev->n_erased_blocks);
414                         return dev->alloc_block_finder;
415                 }
416         }
417
418         yaffs_trace(YAFFS_TRACE_ALWAYS,
419                 "yaffs tragedy: no more erased blocks, but there should have been %d",
420                 dev->n_erased_blocks);
421
422         return -1;
423 }
424
425 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
426                              struct yaffs_block_info **block_ptr)
427 {
428         int ret_val;
429         struct yaffs_block_info *bi;
430
431         if (dev->alloc_block < 0) {
432                 /* Get next block to allocate off */
433                 dev->alloc_block = yaffs_find_alloc_block(dev);
434                 dev->alloc_page = 0;
435         }
436
437         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
438                 /* No space unless we're allowed to use the reserve. */
439                 return -1;
440         }
441
442         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
443             && dev->alloc_page == 0)
444                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
445
446         /* Next page please.... */
447         if (dev->alloc_block >= 0) {
448                 bi = yaffs_get_block_info(dev, dev->alloc_block);
449
450                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
451                     dev->alloc_page;
452                 bi->pages_in_use++;
453                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
454
455                 dev->alloc_page++;
456
457                 dev->n_free_chunks--;
458
459                 /* If the block is full set the state to full */
460                 if (dev->alloc_page >= dev->param.chunks_per_block) {
461                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
462                         dev->alloc_block = -1;
463                 }
464
465                 if (block_ptr)
466                         *block_ptr = bi;
467
468                 return ret_val;
469         }
470
471         yaffs_trace(YAFFS_TRACE_ERROR,
472                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
473
474         return -1;
475 }
476
477 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
478 {
479         int n;
480
481         n = dev->n_erased_blocks * dev->param.chunks_per_block;
482
483         if (dev->alloc_block > 0)
484                 n += (dev->param.chunks_per_block - dev->alloc_page);
485
486         return n;
487
488 }
489
490 /*
491  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
492  * if we don't want to write to it.
493  */
494 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
495 {
496         struct yaffs_block_info *bi;
497
498         if (dev->alloc_block > 0) {
499                 bi = yaffs_get_block_info(dev, dev->alloc_block);
500                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
501                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
502                         dev->alloc_block = -1;
503                 }
504         }
505 }
506
507 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
508                                  const u8 *data,
509                                  struct yaffs_ext_tags *tags, int use_reserver)
510 {
511         int attempts = 0;
512         int write_ok = 0;
513         int chunk;
514
515         yaffs2_checkpt_invalidate(dev);
516
517         do {
518                 struct yaffs_block_info *bi = 0;
519                 int erased_ok = 0;
520
521                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
522                 if (chunk < 0) {
523                         /* no space */
524                         break;
525                 }
526
527                 /* First check this chunk is erased, if it needs
528                  * checking.  The checking policy (unless forced
529                  * always on) is as follows:
530                  *
531                  * Check the first page we try to write in a block.
532                  * If the check passes then we don't need to check any
533                  * more.        If the check fails, we check again...
534                  * If the block has been erased, we don't need to check.
535                  *
536                  * However, if the block has been prioritised for gc,
537                  * then we think there might be something odd about
538                  * this block and stop using it.
539                  *
540                  * Rationale: We should only ever see chunks that have
541                  * not been erased if there was a partially written
542                  * chunk due to power loss.  This checking policy should
543                  * catch that case with very few checks and thus save a
544                  * lot of checks that are most likely not needed.
545                  *
546                  * Mods to the above
547                  * If an erase check fails or the write fails we skip the
548                  * rest of the block.
549                  */
550
551                 /* let's give it a try */
552                 attempts++;
553
554                 if (dev->param.always_check_erased)
555                         bi->skip_erased_check = 0;
556
557                 if (!bi->skip_erased_check) {
558                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
559                         if (erased_ok != YAFFS_OK) {
560                                 yaffs_trace(YAFFS_TRACE_ERROR,
561                                   "**>> yaffs chunk %d was not erased",
562                                   chunk);
563
564                                 /* If not erased, delete this one,
565                                  * skip rest of block and
566                                  * try another chunk */
567                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
568                                 yaffs_skip_rest_of_block(dev);
569                                 continue;
570                         }
571                 }
572
573                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
574
575                 if (!bi->skip_erased_check)
576                         write_ok =
577                             yaffs_verify_chunk_written(dev, chunk, data, tags);
578
579                 if (write_ok != YAFFS_OK) {
580                         /* Clean up aborted write, skip to next block and
581                          * try another chunk */
582                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
583                         continue;
584                 }
585
586                 bi->skip_erased_check = 1;
587
588                 /* Copy the data into the robustification buffer */
589                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
590
591         } while (write_ok != YAFFS_OK &&
592                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
593
594         if (!write_ok)
595                 chunk = -1;
596
597         if (attempts > 1) {
598                 yaffs_trace(YAFFS_TRACE_ERROR,
599                         "**>> yaffs write required %d attempts",
600                         attempts);
601                 dev->n_retried_writes += (attempts - 1);
602         }
603
604         return chunk;
605 }
606
607 /*
608  * Block retiring for handling a broken block.
609  */
610
611 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
612 {
613         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
614
615         yaffs2_checkpt_invalidate(dev);
616
617         yaffs2_clear_oldest_dirty_seq(dev, bi);
618
619         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
620                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
621                         yaffs_trace(YAFFS_TRACE_ALWAYS,
622                                 "yaffs: Failed to mark bad and erase block %d",
623                                 flash_block);
624                 } else {
625                         struct yaffs_ext_tags tags;
626                         int chunk_id =
627                             flash_block * dev->param.chunks_per_block;
628
629                         u8 *buffer = yaffs_get_temp_buffer(dev);
630
631                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
632                         memset(&tags, 0, sizeof(tags));
633                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
634                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
635                                                            dev->chunk_offset,
636                                                            buffer,
637                                                            &tags) != YAFFS_OK)
638                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
639                                         "yaffs: Failed to write bad block marker to block %d",
640                                         flash_block);
641
642                         yaffs_release_temp_buffer(dev, buffer);
643                 }
644         }
645
646         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
647         bi->gc_prioritise = 0;
648         bi->needs_retiring = 0;
649
650         dev->n_retired_blocks++;
651 }
652
653 /*---------------- Name handling functions ------------*/
654
655 static u16 yaffs_calc_name_sum(const YCHAR *name)
656 {
657         u16 sum = 0;
658         u16 i = 1;
659
660         if (!name)
661                 return 0;
662
663         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
664
665                 /* 0x1f mask is case insensitive */
666                 sum += ((*name) & 0x1f) * i;
667                 i++;
668                 name++;
669         }
670         return sum;
671 }
672
673 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
674 {
675         memset(obj->short_name, 0, sizeof(obj->short_name));
676         if (name &&
677                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
678                 YAFFS_SHORT_NAME_LENGTH)
679                 strcpy(obj->short_name, name);
680         else
681                 obj->short_name[0] = _Y('\0');
682         obj->sum = yaffs_calc_name_sum(name);
683 }
684
685 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
686                                 const struct yaffs_obj_hdr *oh)
687 {
688 #ifdef CONFIG_YAFFS_AUTO_UNICODE
689         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
690         memset(tmp_name, 0, sizeof(tmp_name));
691         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
692                                 YAFFS_MAX_NAME_LENGTH + 1);
693         yaffs_set_obj_name(obj, tmp_name);
694 #else
695         yaffs_set_obj_name(obj, oh->name);
696 #endif
697 }
698
699 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
700 {
701         return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
702 }
703
704 /*-------------------- TNODES -------------------
705
706  * List of spare tnodes
707  * The list is hooked together using the first pointer
708  * in the tnode.
709  */
710
711 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
712 {
713         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
714
715         if (tn) {
716                 memset(tn, 0, dev->tnode_size);
717                 dev->n_tnodes++;
718         }
719
720         dev->checkpoint_blocks_required = 0;    /* force recalculation */
721
722         return tn;
723 }
724
725 /* FreeTnode frees up a tnode and puts it back on the free list */
726 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
727 {
728         yaffs_free_raw_tnode(dev, tn);
729         dev->n_tnodes--;
730         dev->checkpoint_blocks_required = 0;    /* force recalculation */
731 }
732
733 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
734 {
735         yaffs_deinit_raw_tnodes_and_objs(dev);
736         dev->n_obj = 0;
737         dev->n_tnodes = 0;
738 }
739
740 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
741                         unsigned pos, unsigned val)
742 {
743         u32 *map = (u32 *) tn;
744         u32 bit_in_map;
745         u32 bit_in_word;
746         u32 word_in_map;
747         u32 mask;
748
749         pos &= YAFFS_TNODES_LEVEL0_MASK;
750         val >>= dev->chunk_grp_bits;
751
752         bit_in_map = pos * dev->tnode_width;
753         word_in_map = bit_in_map / 32;
754         bit_in_word = bit_in_map & (32 - 1);
755
756         mask = dev->tnode_mask << bit_in_word;
757
758         map[word_in_map] &= ~mask;
759         map[word_in_map] |= (mask & (val << bit_in_word));
760
761         if (dev->tnode_width > (32 - bit_in_word)) {
762                 bit_in_word = (32 - bit_in_word);
763                 word_in_map++;
764                 mask =
765                     dev->tnode_mask >> bit_in_word;
766                 map[word_in_map] &= ~mask;
767                 map[word_in_map] |= (mask & (val >> bit_in_word));
768         }
769 }
770
771 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
772                          unsigned pos)
773 {
774         u32 *map = (u32 *) tn;
775         u32 bit_in_map;
776         u32 bit_in_word;
777         u32 word_in_map;
778         u32 val;
779
780         pos &= YAFFS_TNODES_LEVEL0_MASK;
781
782         bit_in_map = pos * dev->tnode_width;
783         word_in_map = bit_in_map / 32;
784         bit_in_word = bit_in_map & (32 - 1);
785
786         val = map[word_in_map] >> bit_in_word;
787
788         if (dev->tnode_width > (32 - bit_in_word)) {
789                 bit_in_word = (32 - bit_in_word);
790                 word_in_map++;
791                 val |= (map[word_in_map] << bit_in_word);
792         }
793
794         val &= dev->tnode_mask;
795         val <<= dev->chunk_grp_bits;
796
797         return val;
798 }
799
800 /* ------------------- End of individual tnode manipulation -----------------*/
801
802 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
803  * The look up tree is represented by the top tnode and the number of top_level
804  * in the tree. 0 means only the level 0 tnode is in the tree.
805  */
806
807 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
808 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
809                                        struct yaffs_file_var *file_struct,
810                                        u32 chunk_id)
811 {
812         struct yaffs_tnode *tn = file_struct->top;
813         u32 i;
814         int required_depth;
815         int level = file_struct->top_level;
816
817         dev = dev;
818
819         /* Check sane level and chunk Id */
820         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
821                 return NULL;
822
823         if (chunk_id > YAFFS_MAX_CHUNK_ID)
824                 return NULL;
825
826         /* First check we're tall enough (ie enough top_level) */
827
828         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
829         required_depth = 0;
830         while (i) {
831                 i >>= YAFFS_TNODES_INTERNAL_BITS;
832                 required_depth++;
833         }
834
835         if (required_depth > file_struct->top_level)
836                 return NULL;    /* Not tall enough, so we can't find it */
837
838         /* Traverse down to level 0 */
839         while (level > 0 && tn) {
840                 tn = tn->internal[(chunk_id >>
841                                    (YAFFS_TNODES_LEVEL0_BITS +
842                                     (level - 1) *
843                                     YAFFS_TNODES_INTERNAL_BITS)) &
844                                   YAFFS_TNODES_INTERNAL_MASK];
845                 level--;
846         }
847
848         return tn;
849 }
850
851 /* add_find_tnode_0 finds the level 0 tnode if it exists,
852  * otherwise first expands the tree.
853  * This happens in two steps:
854  *  1. If the tree isn't tall enough, then make it taller.
855  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
856  *
857  * Used when modifying the tree.
858  *
859  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
860  *  specified tn will be plugged into the ttree.
861  */
862
863 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
864                                            struct yaffs_file_var *file_struct,
865                                            u32 chunk_id,
866                                            struct yaffs_tnode *passed_tn)
867 {
868         int required_depth;
869         int i;
870         int l;
871         struct yaffs_tnode *tn;
872         u32 x;
873
874         /* Check sane level and page Id */
875         if (file_struct->top_level < 0 ||
876             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
877                 return NULL;
878
879         if (chunk_id > YAFFS_MAX_CHUNK_ID)
880                 return NULL;
881
882         /* First check we're tall enough (ie enough top_level) */
883
884         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
885         required_depth = 0;
886         while (x) {
887                 x >>= YAFFS_TNODES_INTERNAL_BITS;
888                 required_depth++;
889         }
890
891         if (required_depth > file_struct->top_level) {
892                 /* Not tall enough, gotta make the tree taller */
893                 for (i = file_struct->top_level; i < required_depth; i++) {
894
895                         tn = yaffs_get_tnode(dev);
896
897                         if (tn) {
898                                 tn->internal[0] = file_struct->top;
899                                 file_struct->top = tn;
900                                 file_struct->top_level++;
901                         } else {
902                                 yaffs_trace(YAFFS_TRACE_ERROR,
903                                         "yaffs: no more tnodes");
904                                 return NULL;
905                         }
906                 }
907         }
908
909         /* Traverse down to level 0, adding anything we need */
910
911         l = file_struct->top_level;
912         tn = file_struct->top;
913
914         if (l > 0) {
915                 while (l > 0 && tn) {
916                         x = (chunk_id >>
917                              (YAFFS_TNODES_LEVEL0_BITS +
918                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
919                             YAFFS_TNODES_INTERNAL_MASK;
920
921                         if ((l > 1) && !tn->internal[x]) {
922                                 /* Add missing non-level-zero tnode */
923                                 tn->internal[x] = yaffs_get_tnode(dev);
924                                 if (!tn->internal[x])
925                                         return NULL;
926                         } else if (l == 1) {
927                                 /* Looking from level 1 at level 0 */
928                                 if (passed_tn) {
929                                         /* If we already have one, release it */
930                                         if (tn->internal[x])
931                                                 yaffs_free_tnode(dev,
932                                                         tn->internal[x]);
933                                         tn->internal[x] = passed_tn;
934
935                                 } else if (!tn->internal[x]) {
936                                         /* Don't have one, none passed in */
937                                         tn->internal[x] = yaffs_get_tnode(dev);
938                                         if (!tn->internal[x])
939                                                 return NULL;
940                                 }
941                         }
942
943                         tn = tn->internal[x];
944                         l--;
945                 }
946         } else {
947                 /* top is level 0 */
948                 if (passed_tn) {
949                         memcpy(tn, passed_tn,
950                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
951                         yaffs_free_tnode(dev, passed_tn);
952                 }
953         }
954
955         return tn;
956 }
957
958 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
959                             int chunk_obj)
960 {
961         return (tags->chunk_id == chunk_obj &&
962                 tags->obj_id == obj_id &&
963                 !tags->is_deleted) ? 1 : 0;
964
965 }
966
967 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
968                                         struct yaffs_ext_tags *tags, int obj_id,
969                                         int inode_chunk)
970 {
971         int j;
972
973         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
974                 if (yaffs_check_chunk_bit
975                     (dev, the_chunk / dev->param.chunks_per_block,
976                      the_chunk % dev->param.chunks_per_block)) {
977
978                         if (dev->chunk_grp_size == 1)
979                                 return the_chunk;
980                         else {
981                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
982                                                          tags);
983                                 if (yaffs_tags_match(tags,
984                                                         obj_id, inode_chunk)) {
985                                         /* found it; */
986                                         return the_chunk;
987                                 }
988                         }
989                 }
990                 the_chunk++;
991         }
992         return -1;
993 }
994
995 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
996                                     struct yaffs_ext_tags *tags)
997 {
998         /*Get the Tnode, then get the level 0 offset chunk offset */
999         struct yaffs_tnode *tn;
1000         int the_chunk = -1;
1001         struct yaffs_ext_tags local_tags;
1002         int ret_val = -1;
1003         struct yaffs_dev *dev = in->my_dev;
1004
1005         if (!tags) {
1006                 /* Passed a NULL, so use our own tags space */
1007                 tags = &local_tags;
1008         }
1009
1010         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1011
1012         if (!tn)
1013                 return ret_val;
1014
1015         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1016
1017         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1018                                               inode_chunk);
1019         return ret_val;
1020 }
1021
1022 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1023                                      struct yaffs_ext_tags *tags)
1024 {
1025         /* Get the Tnode, then get the level 0 offset chunk offset */
1026         struct yaffs_tnode *tn;
1027         int the_chunk = -1;
1028         struct yaffs_ext_tags local_tags;
1029         struct yaffs_dev *dev = in->my_dev;
1030         int ret_val = -1;
1031
1032         if (!tags) {
1033                 /* Passed a NULL, so use our own tags space */
1034                 tags = &local_tags;
1035         }
1036
1037         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1038
1039         if (!tn)
1040                 return ret_val;
1041
1042         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1043
1044         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1045                                               inode_chunk);
1046
1047         /* Delete the entry in the filestructure (if found) */
1048         if (ret_val != -1)
1049                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1050
1051         return ret_val;
1052 }
1053
1054 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1055                             int nand_chunk, int in_scan)
1056 {
1057         /* NB in_scan is zero unless scanning.
1058          * For forward scanning, in_scan is > 0;
1059          * for backward scanning in_scan is < 0
1060          *
1061          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1062          */
1063
1064         struct yaffs_tnode *tn;
1065         struct yaffs_dev *dev = in->my_dev;
1066         int existing_cunk;
1067         struct yaffs_ext_tags existing_tags;
1068         struct yaffs_ext_tags new_tags;
1069         unsigned existing_serial, new_serial;
1070
1071         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1072                 /* Just ignore an attempt at putting a chunk into a non-file
1073                  * during scanning.
1074                  * If it is not during Scanning then something went wrong!
1075                  */
1076                 if (!in_scan) {
1077                         yaffs_trace(YAFFS_TRACE_ERROR,
1078                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1079                                 );
1080                         BUG();
1081                 }
1082
1083                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1084                 return YAFFS_OK;
1085         }
1086
1087         tn = yaffs_add_find_tnode_0(dev,
1088                                     &in->variant.file_variant,
1089                                     inode_chunk, NULL);
1090         if (!tn)
1091                 return YAFFS_FAIL;
1092
1093         if (!nand_chunk)
1094                 /* Dummy insert, bail now */
1095                 return YAFFS_OK;
1096
1097         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1098
1099         if (in_scan != 0) {
1100                 /* If we're scanning then we need to test for duplicates
1101                  * NB This does not need to be efficient since it should only
1102                  * happen when the power fails during a write, then only one
1103                  * chunk should ever be affected.
1104                  *
1105                  * Correction for YAFFS2: This could happen quite a lot and we
1106                  * need to think about efficiency! TODO
1107                  * Update: For backward scanning we don't need to re-read tags
1108                  * so this is quite cheap.
1109                  */
1110
1111                 if (existing_cunk > 0) {
1112                         /* NB Right now existing chunk will not be real
1113                          * chunk_id if the chunk group size > 1
1114                          * thus we have to do a FindChunkInFile to get the
1115                          * real chunk id.
1116                          *
1117                          * We have a duplicate now we need to decide which
1118                          * one to use:
1119                          *
1120                          * Backwards scanning YAFFS2: The old one is what
1121                          * we use, dump the new one.
1122                          * YAFFS1: Get both sets of tags and compare serial
1123                          * numbers.
1124                          */
1125
1126                         if (in_scan > 0) {
1127                                 /* Only do this for forward scanning */
1128                                 yaffs_rd_chunk_tags_nand(dev,
1129                                                          nand_chunk,
1130                                                          NULL, &new_tags);
1131
1132                                 /* Do a proper find */
1133                                 existing_cunk =
1134                                     yaffs_find_chunk_in_file(in, inode_chunk,
1135                                                              &existing_tags);
1136                         }
1137
1138                         if (existing_cunk <= 0) {
1139                                 /*Hoosterman - how did this happen? */
1140
1141                                 yaffs_trace(YAFFS_TRACE_ERROR,
1142                                         "yaffs tragedy: existing chunk < 0 in scan"
1143                                         );
1144
1145                         }
1146
1147                         /* NB The deleted flags should be false, otherwise
1148                          * the chunks will not be loaded during a scan
1149                          */
1150
1151                         if (in_scan > 0) {
1152                                 new_serial = new_tags.serial_number;
1153                                 existing_serial = existing_tags.serial_number;
1154                         }
1155
1156                         if ((in_scan > 0) &&
1157                             (existing_cunk <= 0 ||
1158                              ((existing_serial + 1) & 3) == new_serial)) {
1159                                 /* Forward scanning.
1160                                  * Use new
1161                                  * Delete the old one and drop through to
1162                                  * update the tnode
1163                                  */
1164                                 yaffs_chunk_del(dev, existing_cunk, 1,
1165                                                 __LINE__);
1166                         } else {
1167                                 /* Backward scanning or we want to use the
1168                                  * existing one
1169                                  * Delete the new one and return early so that
1170                                  * the tnode isn't changed
1171                                  */
1172                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1173                                 return YAFFS_OK;
1174                         }
1175                 }
1176
1177         }
1178
1179         if (existing_cunk == 0)
1180                 in->n_data_chunks++;
1181
1182         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1183
1184         return YAFFS_OK;
1185 }
1186
1187 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1188 {
1189         struct yaffs_block_info *the_block;
1190         unsigned block_no;
1191
1192         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1193
1194         block_no = chunk / dev->param.chunks_per_block;
1195         the_block = yaffs_get_block_info(dev, block_no);
1196         if (the_block) {
1197                 the_block->soft_del_pages++;
1198                 dev->n_free_chunks++;
1199                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1200         }
1201 }
1202
1203 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1204  * the chunks in the file.
1205  * All soft deleting does is increment the block's softdelete count and pulls
1206  * the chunk out of the tnode.
1207  * Thus, essentially this is the same as DeleteWorker except that the chunks
1208  * are soft deleted.
1209  */
1210
1211 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1212                                  u32 level, int chunk_offset)
1213 {
1214         int i;
1215         int the_chunk;
1216         int all_done = 1;
1217         struct yaffs_dev *dev = in->my_dev;
1218
1219         if (!tn)
1220                 return 1;
1221
1222         if (level > 0) {
1223                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1224                         all_done && i >= 0;
1225                         i--) {
1226                         if (tn->internal[i]) {
1227                                 all_done =
1228                                     yaffs_soft_del_worker(in,
1229                                         tn->internal[i],
1230                                         level - 1,
1231                                         (chunk_offset <<
1232                                         YAFFS_TNODES_INTERNAL_BITS)
1233                                         + i);
1234                                 if (all_done) {
1235                                         yaffs_free_tnode(dev,
1236                                                 tn->internal[i]);
1237                                         tn->internal[i] = NULL;
1238                                 } else {
1239                                         /* Can this happen? */
1240                                 }
1241                         }
1242                 }
1243                 return (all_done) ? 1 : 0;
1244         }
1245
1246         /* level 0 */
1247          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1248                 the_chunk = yaffs_get_group_base(dev, tn, i);
1249                 if (the_chunk) {
1250                         yaffs_soft_del_chunk(dev, the_chunk);
1251                         yaffs_load_tnode_0(dev, tn, i, 0);
1252                 }
1253         }
1254         return 1;
1255 }
1256
1257 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1258 {
1259         struct yaffs_dev *dev = obj->my_dev;
1260         struct yaffs_obj *parent;
1261
1262         yaffs_verify_obj_in_dir(obj);
1263         parent = obj->parent;
1264
1265         yaffs_verify_dir(parent);
1266
1267         if (dev && dev->param.remove_obj_fn)
1268                 dev->param.remove_obj_fn(obj);
1269
1270         list_del_init(&obj->siblings);
1271         obj->parent = NULL;
1272
1273         yaffs_verify_dir(parent);
1274 }
1275
1276 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1277 {
1278         if (!directory) {
1279                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1280                         "tragedy: Trying to add an object to a null pointer directory"
1281                         );
1282                 BUG();
1283                 return;
1284         }
1285         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1286                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1287                         "tragedy: Trying to add an object to a non-directory"
1288                         );
1289                 BUG();
1290         }
1291
1292         if (obj->siblings.prev == NULL) {
1293                 /* Not initialised */
1294                 BUG();
1295         }
1296
1297         yaffs_verify_dir(directory);
1298
1299         yaffs_remove_obj_from_dir(obj);
1300
1301         /* Now add it */
1302         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1303         obj->parent = directory;
1304
1305         if (directory == obj->my_dev->unlinked_dir
1306             || directory == obj->my_dev->del_dir) {
1307                 obj->unlinked = 1;
1308                 obj->my_dev->n_unlinked_files++;
1309                 obj->rename_allowed = 0;
1310         }
1311
1312         yaffs_verify_dir(directory);
1313         yaffs_verify_obj_in_dir(obj);
1314 }
1315
1316 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1317                                  struct yaffs_obj *new_dir,
1318                                  const YCHAR *new_name, int force, int shadows)
1319 {
1320         int unlink_op;
1321         int del_op;
1322         struct yaffs_obj *existing_target;
1323
1324         if (new_dir == NULL)
1325                 new_dir = obj->parent;  /* use the old directory */
1326
1327         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1328                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1329                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1330                         );
1331                 BUG();
1332         }
1333
1334         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1335         del_op = (new_dir == obj->my_dev->del_dir);
1336
1337         existing_target = yaffs_find_by_name(new_dir, new_name);
1338
1339         /* If the object is a file going into the unlinked directory,
1340          *   then it is OK to just stuff it in since duplicate names are OK.
1341          *   else only proceed if the new name does not exist and we're putting
1342          *   it into a directory.
1343          */
1344         if (!(unlink_op || del_op || force ||
1345               shadows > 0 || !existing_target) ||
1346               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1347                 return YAFFS_FAIL;
1348
1349         yaffs_set_obj_name(obj, new_name);
1350         obj->dirty = 1;
1351         yaffs_add_obj_to_dir(new_dir, obj);
1352
1353         if (unlink_op)
1354                 obj->unlinked = 1;
1355
1356         /* If it is a deletion then we mark it as a shrink for gc  */
1357         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1358                 return YAFFS_OK;
1359
1360         return YAFFS_FAIL;
1361 }
1362
1363 /*------------------------ Short Operations Cache ------------------------------
1364  *   In many situations where there is no high level buffering  a lot of
1365  *   reads might be short sequential reads, and a lot of writes may be short
1366  *   sequential writes. eg. scanning/writing a jpeg file.
1367  *   In these cases, a short read/write cache can provide a huge perfomance
1368  *   benefit with dumb-as-a-rock code.
1369  *   In Linux, the page cache provides read buffering and the short op cache
1370  *   provides write buffering.
1371  *
1372  *   There are a small number (~10) of cache chunks per device so that we don't
1373  *   need a very intelligent search.
1374  */
1375
1376 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1377 {
1378         struct yaffs_dev *dev = obj->my_dev;
1379         int i;
1380         struct yaffs_cache *cache;
1381         int n_caches = obj->my_dev->param.n_caches;
1382
1383         for (i = 0; i < n_caches; i++) {
1384                 cache = &dev->cache[i];
1385                 if (cache->object == obj && cache->dirty)
1386                         return 1;
1387         }
1388
1389         return 0;
1390 }
1391
1392 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1393 {
1394         struct yaffs_dev *dev = obj->my_dev;
1395         int lowest = -99;       /* Stop compiler whining. */
1396         int i;
1397         struct yaffs_cache *cache;
1398         int chunk_written = 0;
1399         int n_caches = obj->my_dev->param.n_caches;
1400
1401         if (n_caches < 1)
1402                 return;
1403         do {
1404                 cache = NULL;
1405
1406                 /* Find the lowest dirty chunk for this object */
1407                 for (i = 0; i < n_caches; i++) {
1408                         if (dev->cache[i].object == obj &&
1409                             dev->cache[i].dirty) {
1410                                 if (!cache ||
1411                                     dev->cache[i].chunk_id < lowest) {
1412                                         cache = &dev->cache[i];
1413                                         lowest = cache->chunk_id;
1414                                 }
1415                         }
1416                 }
1417
1418                 if (cache && !cache->locked) {
1419                         /* Write it out and free it up */
1420                         chunk_written =
1421                             yaffs_wr_data_obj(cache->object,
1422                                               cache->chunk_id,
1423                                               cache->data,
1424                                               cache->n_bytes, 1);
1425                         cache->dirty = 0;
1426                         cache->object = NULL;
1427                 }
1428         } while (cache && chunk_written > 0);
1429
1430         if (cache)
1431                 /* Hoosterman, disk full while writing cache out. */
1432                 yaffs_trace(YAFFS_TRACE_ERROR,
1433                         "yaffs tragedy: no space during cache write");
1434 }
1435
1436 /*yaffs_flush_whole_cache(dev)
1437  *
1438  *
1439  */
1440
1441 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1442 {
1443         struct yaffs_obj *obj;
1444         int n_caches = dev->param.n_caches;
1445         int i;
1446
1447         /* Find a dirty object in the cache and flush it...
1448          * until there are no further dirty objects.
1449          */
1450         do {
1451                 obj = NULL;
1452                 for (i = 0; i < n_caches && !obj; i++) {
1453                         if (dev->cache[i].object && dev->cache[i].dirty)
1454                                 obj = dev->cache[i].object;
1455                 }
1456                 if (obj)
1457                         yaffs_flush_file_cache(obj);
1458         } while (obj);
1459
1460 }
1461
1462 /* Grab us a cache chunk for use.
1463  * First look for an empty one.
1464  * Then look for the least recently used non-dirty one.
1465  * Then look for the least recently used dirty one...., flush and look again.
1466  */
1467 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1468 {
1469         int i;
1470
1471         if (dev->param.n_caches > 0) {
1472                 for (i = 0; i < dev->param.n_caches; i++) {
1473                         if (!dev->cache[i].object)
1474                                 return &dev->cache[i];
1475                 }
1476         }
1477         return NULL;
1478 }
1479
1480 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1481 {
1482         struct yaffs_cache *cache;
1483         struct yaffs_obj *the_obj;
1484         int usage;
1485         int i;
1486         int pushout;
1487
1488         if (dev->param.n_caches < 1)
1489                 return NULL;
1490
1491         /* Try find a non-dirty one... */
1492
1493         cache = yaffs_grab_chunk_worker(dev);
1494
1495         if (!cache) {
1496                 /* They were all dirty, find the LRU object and flush
1497                  * its cache, then  find again.
1498                  * NB what's here is not very accurate,
1499                  * we actually flush the object with the LRU chunk.
1500                  */
1501
1502                 /* With locking we can't assume we can use entry zero,
1503                  * Set the_obj to a valid pointer for Coverity. */
1504                 the_obj = dev->cache[0].object;
1505                 usage = -1;
1506                 cache = NULL;
1507                 pushout = -1;
1508
1509                 for (i = 0; i < dev->param.n_caches; i++) {
1510                         if (dev->cache[i].object &&
1511                             !dev->cache[i].locked &&
1512                             (dev->cache[i].last_use < usage ||
1513                             !cache)) {
1514                                 usage = dev->cache[i].last_use;
1515                                 the_obj = dev->cache[i].object;
1516                                 cache = &dev->cache[i];
1517                                 pushout = i;
1518                         }
1519                 }
1520
1521                 if (!cache || cache->dirty) {
1522                         /* Flush and try again */
1523                         yaffs_flush_file_cache(the_obj);
1524                         cache = yaffs_grab_chunk_worker(dev);
1525                 }
1526         }
1527         return cache;
1528 }
1529
1530 /* Find a cached chunk */
1531 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1532                                                   int chunk_id)
1533 {
1534         struct yaffs_dev *dev = obj->my_dev;
1535         int i;
1536
1537         if (dev->param.n_caches < 1)
1538                 return NULL;
1539
1540         for (i = 0; i < dev->param.n_caches; i++) {
1541                 if (dev->cache[i].object == obj &&
1542                     dev->cache[i].chunk_id == chunk_id) {
1543                         dev->cache_hits++;
1544
1545                         return &dev->cache[i];
1546                 }
1547         }
1548         return NULL;
1549 }
1550
1551 /* Mark the chunk for the least recently used algorithym */
1552 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1553                             int is_write)
1554 {
1555         int i;
1556
1557         if (dev->param.n_caches < 1)
1558                 return;
1559
1560         if (dev->cache_last_use < 0 ||
1561                 dev->cache_last_use > 100000000) {
1562                 /* Reset the cache usages */
1563                 for (i = 1; i < dev->param.n_caches; i++)
1564                         dev->cache[i].last_use = 0;
1565
1566                 dev->cache_last_use = 0;
1567         }
1568         dev->cache_last_use++;
1569         cache->last_use = dev->cache_last_use;
1570
1571         if (is_write)
1572                 cache->dirty = 1;
1573 }
1574
1575 /* Invalidate a single cache page.
1576  * Do this when a whole page gets written,
1577  * ie the short cache for this page is no longer valid.
1578  */
1579 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1580 {
1581         struct yaffs_cache *cache;
1582
1583         if (object->my_dev->param.n_caches > 0) {
1584                 cache = yaffs_find_chunk_cache(object, chunk_id);
1585
1586                 if (cache)
1587                         cache->object = NULL;
1588         }
1589 }
1590
1591 /* Invalidate all the cache pages associated with this object
1592  * Do this whenever ther file is deleted or resized.
1593  */
1594 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1595 {
1596         int i;
1597         struct yaffs_dev *dev = in->my_dev;
1598
1599         if (dev->param.n_caches > 0) {
1600                 /* Invalidate it. */
1601                 for (i = 0; i < dev->param.n_caches; i++) {
1602                         if (dev->cache[i].object == in)
1603                                 dev->cache[i].object = NULL;
1604                 }
1605         }
1606 }
1607
1608 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1609 {
1610         int bucket;
1611         struct yaffs_dev *dev = obj->my_dev;
1612
1613         /* If it is still linked into the bucket list, free from the list */
1614         if (!list_empty(&obj->hash_link)) {
1615                 list_del_init(&obj->hash_link);
1616                 bucket = yaffs_hash_fn(obj->obj_id);
1617                 dev->obj_bucket[bucket].count--;
1618         }
1619 }
1620
1621 /*  FreeObject frees up a Object and puts it back on the free list */
1622 static void yaffs_free_obj(struct yaffs_obj *obj)
1623 {
1624         struct yaffs_dev *dev;
1625
1626         if (!obj) {
1627                 BUG();
1628                 return;
1629         }
1630         dev = obj->my_dev;
1631         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1632                 obj, obj->my_inode);
1633         if (obj->parent)
1634                 BUG();
1635         if (!list_empty(&obj->siblings))
1636                 BUG();
1637
1638         if (obj->my_inode) {
1639                 /* We're still hooked up to a cached inode.
1640                  * Don't delete now, but mark for later deletion
1641                  */
1642                 obj->defered_free = 1;
1643                 return;
1644         }
1645
1646         yaffs_unhash_obj(obj);
1647
1648         yaffs_free_raw_obj(dev, obj);
1649         dev->n_obj--;
1650         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1651 }
1652
1653 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1654 {
1655         if (obj->defered_free)
1656                 yaffs_free_obj(obj);
1657 }
1658
1659 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1660 {
1661         /* Iinvalidate the file's data in the cache, without flushing. */
1662         yaffs_invalidate_whole_cache(in);
1663
1664         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1665                 /* Move to unlinked directory so we have a deletion record */
1666                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1667                                       0);
1668         }
1669
1670         yaffs_remove_obj_from_dir(in);
1671         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1672         in->hdr_chunk = 0;
1673
1674         yaffs_free_obj(in);
1675         return YAFFS_OK;
1676
1677 }
1678
1679 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1680 {
1681         if (!obj->deleted ||
1682             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1683             obj->soft_del)
1684                 return;
1685
1686         if (obj->n_data_chunks <= 0) {
1687                 /* Empty file with no duplicate object headers,
1688                  * just delete it immediately */
1689                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1690                 obj->variant.file_variant.top = NULL;
1691                 yaffs_trace(YAFFS_TRACE_TRACING,
1692                         "yaffs: Deleting empty file %d",
1693                         obj->obj_id);
1694                 yaffs_generic_obj_del(obj);
1695         } else {
1696                 yaffs_soft_del_worker(obj,
1697                                       obj->variant.file_variant.top,
1698                                       obj->variant.
1699                                       file_variant.top_level, 0);
1700                 obj->soft_del = 1;
1701         }
1702 }
1703
1704 /* Pruning removes any part of the file structure tree that is beyond the
1705  * bounds of the file (ie that does not point to chunks).
1706  *
1707  * A file should only get pruned when its size is reduced.
1708  *
1709  * Before pruning, the chunks must be pulled from the tree and the
1710  * level 0 tnode entries must be zeroed out.
1711  * Could also use this for file deletion, but that's probably better handled
1712  * by a special case.
1713  *
1714  * This function is recursive. For levels > 0 the function is called again on
1715  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1716  * If there is no data in a subtree then it is pruned.
1717  */
1718
1719 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1720                                               struct yaffs_tnode *tn, u32 level,
1721                                               int del0)
1722 {
1723         int i;
1724         int has_data;
1725
1726         if (!tn)
1727                 return tn;
1728
1729         has_data = 0;
1730
1731         if (level > 0) {
1732                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1733                         if (tn->internal[i]) {
1734                                 tn->internal[i] =
1735                                     yaffs_prune_worker(dev,
1736                                                 tn->internal[i],
1737                                                 level - 1,
1738                                                 (i == 0) ? del0 : 1);
1739                         }
1740
1741                         if (tn->internal[i])
1742                                 has_data++;
1743                 }
1744         } else {
1745                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1746                 u32 *map = (u32 *) tn;
1747
1748                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1749                         if (map[i])
1750                                 has_data++;
1751                 }
1752         }
1753
1754         if (has_data == 0 && del0) {
1755                 /* Free and return NULL */
1756                 yaffs_free_tnode(dev, tn);
1757                 tn = NULL;
1758         }
1759         return tn;
1760 }
1761
1762 static int yaffs_prune_tree(struct yaffs_dev *dev,
1763                             struct yaffs_file_var *file_struct)
1764 {
1765         int i;
1766         int has_data;
1767         int done = 0;
1768         struct yaffs_tnode *tn;
1769
1770         if (file_struct->top_level < 1)
1771                 return YAFFS_OK;
1772
1773         file_struct->top =
1774            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1775
1776         /* Now we have a tree with all the non-zero branches NULL but
1777          * the height is the same as it was.
1778          * Let's see if we can trim internal tnodes to shorten the tree.
1779          * We can do this if only the 0th element in the tnode is in use
1780          * (ie all the non-zero are NULL)
1781          */
1782
1783         while (file_struct->top_level && !done) {
1784                 tn = file_struct->top;
1785
1786                 has_data = 0;
1787                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1788                         if (tn->internal[i])
1789                                 has_data++;
1790                 }
1791
1792                 if (!has_data) {
1793                         file_struct->top = tn->internal[0];
1794                         file_struct->top_level--;
1795                         yaffs_free_tnode(dev, tn);
1796                 } else {
1797                         done = 1;
1798                 }
1799         }
1800
1801         return YAFFS_OK;
1802 }
1803
1804 /*-------------------- End of File Structure functions.-------------------*/
1805
1806 /* alloc_empty_obj gets us a clean Object.*/
1807 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1808 {
1809         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1810
1811         if (!obj)
1812                 return obj;
1813
1814         dev->n_obj++;
1815
1816         /* Now sweeten it up... */
1817
1818         memset(obj, 0, sizeof(struct yaffs_obj));
1819         obj->being_created = 1;
1820
1821         obj->my_dev = dev;
1822         obj->hdr_chunk = 0;
1823         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1824         INIT_LIST_HEAD(&(obj->hard_links));
1825         INIT_LIST_HEAD(&(obj->hash_link));
1826         INIT_LIST_HEAD(&obj->siblings);
1827
1828         /* Now make the directory sane */
1829         if (dev->root_dir) {
1830                 obj->parent = dev->root_dir;
1831                 list_add(&(obj->siblings),
1832                          &dev->root_dir->variant.dir_variant.children);
1833         }
1834
1835         /* Add it to the lost and found directory.
1836          * NB Can't put root or lost-n-found in lost-n-found so
1837          * check if lost-n-found exists first
1838          */
1839         if (dev->lost_n_found)
1840                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1841
1842         obj->being_created = 0;
1843
1844         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1845
1846         return obj;
1847 }
1848
1849 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1850 {
1851         int i;
1852         int l = 999;
1853         int lowest = 999999;
1854
1855         /* Search for the shortest list or one that
1856          * isn't too long.
1857          */
1858
1859         for (i = 0; i < 10 && lowest > 4; i++) {
1860                 dev->bucket_finder++;
1861                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1862                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1863                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1864                         l = dev->bucket_finder;
1865                 }
1866         }
1867
1868         return l;
1869 }
1870
1871 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1872 {
1873         int bucket = yaffs_find_nice_bucket(dev);
1874         int found = 0;
1875         struct list_head *i;
1876         u32 n = (u32) bucket;
1877
1878         /* Now find an object value that has not already been taken
1879          * by scanning the list.
1880          */
1881
1882         while (!found) {
1883                 found = 1;
1884                 n += YAFFS_NOBJECT_BUCKETS;
1885                 if (1 || dev->obj_bucket[bucket].count > 0) {
1886                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1887                                 /* If there is already one in the list */
1888                                 if (i && list_entry(i, struct yaffs_obj,
1889                                                     hash_link)->obj_id == n) {
1890                                         found = 0;
1891                                 }
1892                         }
1893                 }
1894         }
1895         return n;
1896 }
1897
1898 static void yaffs_hash_obj(struct yaffs_obj *in)
1899 {
1900         int bucket = yaffs_hash_fn(in->obj_id);
1901         struct yaffs_dev *dev = in->my_dev;
1902
1903         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1904         dev->obj_bucket[bucket].count++;
1905 }
1906
1907 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1908 {
1909         int bucket = yaffs_hash_fn(number);
1910         struct list_head *i;
1911         struct yaffs_obj *in;
1912
1913         list_for_each(i, &dev->obj_bucket[bucket].list) {
1914                 /* Look if it is in the list */
1915                 in = list_entry(i, struct yaffs_obj, hash_link);
1916                 if (in->obj_id == number) {
1917                         /* Don't show if it is defered free */
1918                         if (in->defered_free)
1919                                 return NULL;
1920                         return in;
1921                 }
1922         }
1923
1924         return NULL;
1925 }
1926
1927 struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1928                                 enum yaffs_obj_type type)
1929 {
1930         struct yaffs_obj *the_obj = NULL;
1931         struct yaffs_tnode *tn = NULL;
1932
1933         if (number < 0)
1934                 number = yaffs_new_obj_id(dev);
1935
1936         if (type == YAFFS_OBJECT_TYPE_FILE) {
1937                 tn = yaffs_get_tnode(dev);
1938                 if (!tn)
1939                         return NULL;
1940         }
1941
1942         the_obj = yaffs_alloc_empty_obj(dev);
1943         if (!the_obj) {
1944                 if (tn)
1945                         yaffs_free_tnode(dev, tn);
1946                 return NULL;
1947         }
1948
1949         the_obj->fake = 0;
1950         the_obj->rename_allowed = 1;
1951         the_obj->unlink_allowed = 1;
1952         the_obj->obj_id = number;
1953         yaffs_hash_obj(the_obj);
1954         the_obj->variant_type = type;
1955         yaffs_load_current_time(the_obj, 1, 1);
1956
1957         switch (type) {
1958         case YAFFS_OBJECT_TYPE_FILE:
1959                 the_obj->variant.file_variant.file_size = 0;
1960                 the_obj->variant.file_variant.scanned_size = 0;
1961                 the_obj->variant.file_variant.shrink_size =
1962                                                 yaffs_max_file_size(dev);
1963                 the_obj->variant.file_variant.top_level = 0;
1964                 the_obj->variant.file_variant.top = tn;
1965                 break;
1966         case YAFFS_OBJECT_TYPE_DIRECTORY:
1967                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1968                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1969                 break;
1970         case YAFFS_OBJECT_TYPE_SYMLINK:
1971         case YAFFS_OBJECT_TYPE_HARDLINK:
1972         case YAFFS_OBJECT_TYPE_SPECIAL:
1973                 /* No action required */
1974                 break;
1975         case YAFFS_OBJECT_TYPE_UNKNOWN:
1976                 /* todo this should not happen */
1977                 break;
1978         }
1979         return the_obj;
1980 }
1981
1982 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1983                                                int number, u32 mode)
1984 {
1985
1986         struct yaffs_obj *obj =
1987             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1988
1989         if (!obj)
1990                 return NULL;
1991
1992         obj->fake = 1;  /* it is fake so it might not use NAND */
1993         obj->rename_allowed = 0;
1994         obj->unlink_allowed = 0;
1995         obj->deleted = 0;
1996         obj->unlinked = 0;
1997         obj->yst_mode = mode;
1998         obj->my_dev = dev;
1999         obj->hdr_chunk = 0;     /* Not a valid chunk. */
2000         return obj;
2001
2002 }
2003
2004
2005 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
2006 {
2007         int i;
2008
2009         dev->n_obj = 0;
2010         dev->n_tnodes = 0;
2011         yaffs_init_raw_tnodes_and_objs(dev);
2012
2013         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2014                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2015                 dev->obj_bucket[i].count = 0;
2016         }
2017 }
2018
2019 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2020                                                  int number,
2021                                                  enum yaffs_obj_type type)
2022 {
2023         struct yaffs_obj *the_obj = NULL;
2024
2025         if (number > 0)
2026                 the_obj = yaffs_find_by_number(dev, number);
2027
2028         if (!the_obj)
2029                 the_obj = yaffs_new_obj(dev, number, type);
2030
2031         return the_obj;
2032
2033 }
2034
2035 YCHAR *yaffs_clone_str(const YCHAR *str)
2036 {
2037         YCHAR *new_str = NULL;
2038         int len;
2039
2040         if (!str)
2041                 str = _Y("");
2042
2043         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2044         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2045         if (new_str) {
2046                 strncpy(new_str, str, len);
2047                 new_str[len] = 0;
2048         }
2049         return new_str;
2050
2051 }
2052 /*
2053  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2054  * link (ie. name) is created or deleted in the directory.
2055  *
2056  * ie.
2057  *   create dir/a : update dir's mtime/ctime
2058  *   rm dir/a:   update dir's mtime/ctime
2059  *   modify dir/a: don't update dir's mtimme/ctime
2060  *
2061  * This can be handled immediately or defered. Defering helps reduce the number
2062  * of updates when many files in a directory are changed within a brief period.
2063  *
2064  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2065  * called periodically.
2066  */
2067
2068 static void yaffs_update_parent(struct yaffs_obj *obj)
2069 {
2070         struct yaffs_dev *dev;
2071
2072         if (!obj)
2073                 return;
2074         dev = obj->my_dev;
2075         obj->dirty = 1;
2076         yaffs_load_current_time(obj, 0, 1);
2077         if (dev->param.defered_dir_update) {
2078                 struct list_head *link = &obj->variant.dir_variant.dirty;
2079
2080                 if (list_empty(link)) {
2081                         list_add(link, &dev->dirty_dirs);
2082                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2083                           "Added object %d to dirty directories",
2084                            obj->obj_id);
2085                 }
2086
2087         } else {
2088                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2089         }
2090 }
2091
2092 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2093 {
2094         struct list_head *link;
2095         struct yaffs_obj *obj;
2096         struct yaffs_dir_var *d_s;
2097         union yaffs_obj_var *o_v;
2098
2099         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2100
2101         while (!list_empty(&dev->dirty_dirs)) {
2102                 link = dev->dirty_dirs.next;
2103                 list_del_init(link);
2104
2105                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2106                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2107                 obj = list_entry(o_v, struct yaffs_obj, variant);
2108
2109                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2110                         obj->obj_id);
2111
2112                 if (obj->dirty)
2113                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2114         }
2115 }
2116
2117 /*
2118  * Mknod (create) a new object.
2119  * equiv_obj only has meaning for a hard link;
2120  * alias_str only has meaning for a symlink.
2121  * rdev only has meaning for devices (a subset of special objects)
2122  */
2123
2124 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2125                                           struct yaffs_obj *parent,
2126                                           const YCHAR *name,
2127                                           u32 mode,
2128                                           u32 uid,
2129                                           u32 gid,
2130                                           struct yaffs_obj *equiv_obj,
2131                                           const YCHAR *alias_str, u32 rdev)
2132 {
2133         struct yaffs_obj *in;
2134         YCHAR *str = NULL;
2135         struct yaffs_dev *dev = parent->my_dev;
2136
2137         /* Check if the entry exists.
2138          * If it does then fail the call since we don't want a dup. */
2139         if (yaffs_find_by_name(parent, name))
2140                 return NULL;
2141
2142         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2143                 str = yaffs_clone_str(alias_str);
2144                 if (!str)
2145                         return NULL;
2146         }
2147
2148         in = yaffs_new_obj(dev, -1, type);
2149
2150         if (!in) {
2151                 kfree(str);
2152                 return NULL;
2153         }
2154
2155         in->hdr_chunk = 0;
2156         in->valid = 1;
2157         in->variant_type = type;
2158
2159         in->yst_mode = mode;
2160
2161         yaffs_attribs_init(in, gid, uid, rdev);
2162
2163         in->n_data_chunks = 0;
2164
2165         yaffs_set_obj_name(in, name);
2166         in->dirty = 1;
2167
2168         yaffs_add_obj_to_dir(parent, in);
2169
2170         in->my_dev = parent->my_dev;
2171
2172         switch (type) {
2173         case YAFFS_OBJECT_TYPE_SYMLINK:
2174                 in->variant.symlink_variant.alias = str;
2175                 break;
2176         case YAFFS_OBJECT_TYPE_HARDLINK:
2177                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2178                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2179                 list_add(&in->hard_links, &equiv_obj->hard_links);
2180                 break;
2181         case YAFFS_OBJECT_TYPE_FILE:
2182         case YAFFS_OBJECT_TYPE_DIRECTORY:
2183         case YAFFS_OBJECT_TYPE_SPECIAL:
2184         case YAFFS_OBJECT_TYPE_UNKNOWN:
2185                 /* do nothing */
2186                 break;
2187         }
2188
2189         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2190                 /* Could not create the object header, fail */
2191                 yaffs_del_obj(in);
2192                 in = NULL;
2193         }
2194
2195         if (in)
2196                 yaffs_update_parent(parent);
2197
2198         return in;
2199 }
2200
2201 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2202                                     const YCHAR *name, u32 mode, u32 uid,
2203                                     u32 gid)
2204 {
2205         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2206                                 uid, gid, NULL, NULL, 0);
2207 }
2208
2209 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2210                                    u32 mode, u32 uid, u32 gid)
2211 {
2212         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2213                                 mode, uid, gid, NULL, NULL, 0);
2214 }
2215
2216 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2217                                        const YCHAR *name, u32 mode, u32 uid,
2218                                        u32 gid, u32 rdev)
2219 {
2220         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2221                                 uid, gid, NULL, NULL, rdev);
2222 }
2223
2224 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2225                                        const YCHAR *name, u32 mode, u32 uid,
2226                                        u32 gid, const YCHAR *alias)
2227 {
2228         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2229                                 uid, gid, NULL, alias, 0);
2230 }
2231
2232 /* yaffs_link_obj returns the object id of the equivalent object.*/
2233 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2234                                  struct yaffs_obj *equiv_obj)
2235 {
2236         /* Get the real object in case we were fed a hard link obj */
2237         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2238
2239         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2240                         parent, name, 0, 0, 0,
2241                         equiv_obj, NULL, 0))
2242                 return equiv_obj;
2243
2244         return NULL;
2245
2246 }
2247
2248
2249
2250 /*---------------------- Block Management and Page Allocation -------------*/
2251
2252 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2253 {
2254         if (dev->block_info_alt && dev->block_info)
2255                 vfree(dev->block_info);
2256         else
2257                 kfree(dev->block_info);
2258
2259         dev->block_info_alt = 0;
2260
2261         dev->block_info = NULL;
2262
2263         if (dev->chunk_bits_alt && dev->chunk_bits)
2264                 vfree(dev->chunk_bits);
2265         else
2266                 kfree(dev->chunk_bits);
2267         dev->chunk_bits_alt = 0;
2268         dev->chunk_bits = NULL;
2269 }
2270
2271 static int yaffs_init_blocks(struct yaffs_dev *dev)
2272 {
2273         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2274
2275         dev->block_info = NULL;
2276         dev->chunk_bits = NULL;
2277         dev->alloc_block = -1;  /* force it to get a new one */
2278
2279         /* If the first allocation strategy fails, thry the alternate one */
2280         dev->block_info =
2281                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2282         if (!dev->block_info) {
2283                 dev->block_info =
2284                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2285                 dev->block_info_alt = 1;
2286         } else {
2287                 dev->block_info_alt = 0;
2288         }
2289
2290         if (!dev->block_info)
2291                 goto alloc_error;
2292
2293         /* Set up dynamic blockinfo stuff. Round up bytes. */
2294         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2295         dev->chunk_bits =
2296                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2297         if (!dev->chunk_bits) {
2298                 dev->chunk_bits =
2299                     vmalloc(dev->chunk_bit_stride * n_blocks);
2300                 dev->chunk_bits_alt = 1;
2301         } else {
2302                 dev->chunk_bits_alt = 0;
2303         }
2304         if (!dev->chunk_bits)
2305                 goto alloc_error;
2306
2307
2308         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2309         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2310         return YAFFS_OK;
2311
2312 alloc_error:
2313         yaffs_deinit_blocks(dev);
2314         return YAFFS_FAIL;
2315 }
2316
2317
2318 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2319 {
2320         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2321         int erased_ok = 0;
2322         int i;
2323
2324         /* If the block is still healthy erase it and mark as clean.
2325          * If the block has had a data failure, then retire it.
2326          */
2327
2328         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2329                 "yaffs_block_became_dirty block %d state %d %s",
2330                 block_no, bi->block_state,
2331                 (bi->needs_retiring) ? "needs retiring" : "");
2332
2333         yaffs2_clear_oldest_dirty_seq(dev, bi);
2334
2335         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2336
2337         /* If this is the block being garbage collected then stop gc'ing */
2338         if (block_no == dev->gc_block)
2339                 dev->gc_block = 0;
2340
2341         /* If this block is currently the best candidate for gc
2342          * then drop as a candidate */
2343         if (block_no == dev->gc_dirtiest) {
2344                 dev->gc_dirtiest = 0;
2345                 dev->gc_pages_in_use = 0;
2346         }
2347
2348         if (!bi->needs_retiring) {
2349                 yaffs2_checkpt_invalidate(dev);
2350                 erased_ok = yaffs_erase_block(dev, block_no);
2351                 if (!erased_ok) {
2352                         dev->n_erase_failures++;
2353                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2354                           "**>> Erasure failed %d", block_no);
2355                 }
2356         }
2357
2358         /* Verify erasure if needed */
2359         if (erased_ok &&
2360             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2361              !yaffs_skip_verification(dev))) {
2362                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2363                         if (!yaffs_check_chunk_erased(dev,
2364                                 block_no * dev->param.chunks_per_block + i)) {
2365                                 yaffs_trace(YAFFS_TRACE_ERROR,
2366                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2367                                         block_no, i);
2368                         }
2369                 }
2370         }
2371
2372         if (!erased_ok) {
2373                 /* We lost a block of free space */
2374                 dev->n_free_chunks -= dev->param.chunks_per_block;
2375                 yaffs_retire_block(dev, block_no);
2376                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2377                         "**>> Block %d retired", block_no);
2378                 return;
2379         }
2380
2381         /* Clean it up... */
2382         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2383         bi->seq_number = 0;
2384         dev->n_erased_blocks++;
2385         bi->pages_in_use = 0;
2386         bi->soft_del_pages = 0;
2387         bi->has_shrink_hdr = 0;
2388         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2389         bi->gc_prioritise = 0;
2390         bi->has_summary=0;
2391
2392         yaffs_clear_chunk_bits(dev, block_no);
2393
2394         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2395 }
2396
2397 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2398                                         struct yaffs_block_info *bi,
2399                                         int old_chunk, u8 *buffer)
2400 {
2401         int new_chunk;
2402         int mark_flash = 1;
2403         struct yaffs_ext_tags tags;
2404         struct yaffs_obj *object;
2405         int matching_chunk;
2406         int ret_val = YAFFS_OK;
2407
2408         memset(&tags, 0, sizeof(tags));
2409         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2410                                  buffer, &tags);
2411         object = yaffs_find_by_number(dev, tags.obj_id);
2412
2413         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2414                 "Collecting chunk in block %d, %d %d %d ",
2415                 dev->gc_chunk, tags.obj_id,
2416                 tags.chunk_id, tags.n_bytes);
2417
2418         if (object && !yaffs_skip_verification(dev)) {
2419                 if (tags.chunk_id == 0)
2420                         matching_chunk =
2421                             object->hdr_chunk;
2422                 else if (object->soft_del)
2423                         /* Defeat the test */
2424                         matching_chunk = old_chunk;
2425                 else
2426                         matching_chunk =
2427                             yaffs_find_chunk_in_file
2428                             (object, tags.chunk_id,
2429                              NULL);
2430
2431                 if (old_chunk != matching_chunk)
2432                         yaffs_trace(YAFFS_TRACE_ERROR,
2433                                 "gc: page in gc mismatch: %d %d %d %d",
2434                                 old_chunk,
2435                                 matching_chunk,
2436                                 tags.obj_id,
2437                                 tags.chunk_id);
2438         }
2439
2440         if (!object) {
2441                 yaffs_trace(YAFFS_TRACE_ERROR,
2442                         "page %d in gc has no object: %d %d %d ",
2443                         old_chunk,
2444                         tags.obj_id, tags.chunk_id,
2445                         tags.n_bytes);
2446         }
2447
2448         if (object &&
2449             object->deleted &&
2450             object->soft_del && tags.chunk_id != 0) {
2451                 /* Data chunk in a soft deleted file,
2452                  * throw it away.
2453                  * It's a soft deleted data chunk,
2454                  * No need to copy this, just forget
2455                  * about it and fix up the object.
2456                  */
2457
2458                 /* Free chunks already includes
2459                  * softdeleted chunks, how ever this
2460                  * chunk is going to soon be really
2461                  * deleted which will increment free
2462                  * chunks. We have to decrement free
2463                  * chunks so this works out properly.
2464                  */
2465                 dev->n_free_chunks--;
2466                 bi->soft_del_pages--;
2467
2468                 object->n_data_chunks--;
2469                 if (object->n_data_chunks <= 0) {
2470                         /* remeber to clean up obj */
2471                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2472                         dev->n_clean_ups++;
2473                 }
2474                 mark_flash = 0;
2475         } else if (object) {
2476                 /* It's either a data chunk in a live
2477                  * file or an ObjectHeader, so we're
2478                  * interested in it.
2479                  * NB Need to keep the ObjectHeaders of
2480                  * deleted files until the whole file
2481                  * has been deleted off
2482                  */
2483                 tags.serial_number++;
2484                 dev->n_gc_copies++;
2485
2486                 if (tags.chunk_id == 0) {
2487                         /* It is an object Id,
2488                          * We need to nuke the
2489                          * shrinkheader flags since its
2490                          * work is done.
2491                          * Also need to clean up
2492                          * shadowing.
2493                          */
2494                         struct yaffs_obj_hdr *oh;
2495                         oh = (struct yaffs_obj_hdr *) buffer;
2496
2497                         oh->is_shrink = 0;
2498                         tags.extra_is_shrink = 0;
2499                         oh->shadows_obj = 0;
2500                         oh->inband_shadowed_obj_id = 0;
2501                         tags.extra_shadows = 0;
2502
2503                         /* Update file size */
2504                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2505                                 yaffs_oh_size_load( oh,
2506                                     object->variant.file_variant.file_size);
2507                                 tags.extra_file_size =
2508                                     object->variant.file_variant.file_size;
2509                         }
2510
2511                         yaffs_verify_oh(object, oh, &tags, 1);
2512                         new_chunk =
2513                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2514                 } else {
2515                         new_chunk =
2516                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2517                 }
2518
2519                 if (new_chunk < 0) {
2520                         ret_val = YAFFS_FAIL;
2521                 } else {
2522
2523                         /* Now fix up the Tnodes etc. */
2524
2525                         if (tags.chunk_id == 0) {
2526                                 /* It's a header */
2527                                 object->hdr_chunk = new_chunk;
2528                                 object->serial = tags.serial_number;
2529                         } else {
2530                                 /* It's a data chunk */
2531                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2532                                                         new_chunk, 0);
2533                         }
2534                 }
2535         }
2536         if (ret_val == YAFFS_OK)
2537                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2538         return ret_val;
2539 }
2540
2541 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2542 {
2543         int old_chunk;
2544         int ret_val = YAFFS_OK;
2545         int i;
2546         int is_checkpt_block;
2547         int max_copies;
2548         int chunks_before = yaffs_get_erased_chunks(dev);
2549         int chunks_after;
2550         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2551
2552         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2553
2554         yaffs_trace(YAFFS_TRACE_TRACING,
2555                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2556                 block, bi->pages_in_use, bi->has_shrink_hdr,
2557                 whole_block);
2558
2559         /*yaffs_verify_free_chunks(dev); */
2560
2561         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2562                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2563
2564         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2565
2566         dev->gc_disable = 1;
2567
2568         yaffs_summary_gc(dev, block);
2569
2570         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2571                 yaffs_trace(YAFFS_TRACE_TRACING,
2572                         "Collecting block %d that has no chunks in use",
2573                         block);
2574                 yaffs_block_became_dirty(dev, block);
2575         } else {
2576
2577                 u8 *buffer = yaffs_get_temp_buffer(dev);
2578
2579                 yaffs_verify_blk(dev, bi, block);
2580
2581                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2582                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2583
2584                 for (/* init already done */ ;
2585                      ret_val == YAFFS_OK &&
2586                      dev->gc_chunk < dev->param.chunks_per_block &&
2587                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2588                      max_copies > 0;
2589                      dev->gc_chunk++, old_chunk++) {
2590                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2591                                 /* Page is in use and might need to be copied */
2592                                 max_copies--;
2593                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2594                                                         old_chunk, buffer);
2595                         }
2596                 }
2597                 yaffs_release_temp_buffer(dev, buffer);
2598         }
2599
2600         yaffs_verify_collected_blk(dev, bi, block);
2601
2602         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2603                 /*
2604                  * The gc did not complete. Set block state back to FULL
2605                  * because checkpointing does not restore gc.
2606                  */
2607                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2608         } else {
2609                 /* The gc completed. */
2610                 /* Do any required cleanups */
2611                 for (i = 0; i < dev->n_clean_ups; i++) {
2612                         /* Time to delete the file too */
2613                         struct yaffs_obj *object =
2614                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2615                         if (object) {
2616                                 yaffs_free_tnode(dev,
2617                                           object->variant.file_variant.top);
2618                                 object->variant.file_variant.top = NULL;
2619                                 yaffs_trace(YAFFS_TRACE_GC,
2620                                         "yaffs: About to finally delete object %d",
2621                                         object->obj_id);
2622                                 yaffs_generic_obj_del(object);
2623                                 object->my_dev->n_deleted_files--;
2624                         }
2625
2626                 }
2627                 chunks_after = yaffs_get_erased_chunks(dev);
2628                 if (chunks_before >= chunks_after)
2629                         yaffs_trace(YAFFS_TRACE_GC,
2630                                 "gc did not increase free chunks before %d after %d",
2631                                 chunks_before, chunks_after);
2632                 dev->gc_block = 0;
2633                 dev->gc_chunk = 0;
2634                 dev->n_clean_ups = 0;
2635         }
2636
2637         dev->gc_disable = 0;
2638
2639         return ret_val;
2640 }
2641
2642 /*
2643  * find_gc_block() selects the dirtiest block (or close enough)
2644  * for garbage collection.
2645  */
2646
2647 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2648                                     int aggressive, int background)
2649 {
2650         int i;
2651         int iterations;
2652         unsigned selected = 0;
2653         int prioritised = 0;
2654         int prioritised_exist = 0;
2655         struct yaffs_block_info *bi;
2656         int threshold;
2657
2658         /* First let's see if we need to grab a prioritised block */
2659         if (dev->has_pending_prioritised_gc && !aggressive) {
2660                 dev->gc_dirtiest = 0;
2661                 bi = dev->block_info;
2662                 for (i = dev->internal_start_block;
2663                      i <= dev->internal_end_block && !selected; i++) {
2664
2665                         if (bi->gc_prioritise) {
2666                                 prioritised_exist = 1;
2667                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2668                                     yaffs_block_ok_for_gc(dev, bi)) {
2669                                         selected = i;
2670                                         prioritised = 1;
2671                                 }
2672                         }
2673                         bi++;
2674                 }
2675
2676                 /*
2677                  * If there is a prioritised block and none was selected then
2678                  * this happened because there is at least one old dirty block
2679                  * gumming up the works. Let's gc the oldest dirty block.
2680                  */
2681
2682                 if (prioritised_exist &&
2683                     !selected && dev->oldest_dirty_block > 0)
2684                         selected = dev->oldest_dirty_block;
2685
2686                 if (!prioritised_exist) /* None found, so we can clear this */
2687                         dev->has_pending_prioritised_gc = 0;
2688         }
2689
2690         /* If we're doing aggressive GC then we are happy to take a less-dirty
2691          * block, and search harder.
2692          * else (leasurely gc), then we only bother to do this if the
2693          * block has only a few pages in use.
2694          */
2695
2696         if (!selected) {
2697                 int pages_used;
2698                 int n_blocks =
2699                     dev->internal_end_block - dev->internal_start_block + 1;
2700                 if (aggressive) {
2701                         threshold = dev->param.chunks_per_block;
2702                         iterations = n_blocks;
2703                 } else {
2704                         int max_threshold;
2705
2706                         if (background)
2707                                 max_threshold = dev->param.chunks_per_block / 2;
2708                         else
2709                                 max_threshold = dev->param.chunks_per_block / 8;
2710
2711                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2712                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2713
2714                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2715                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2716                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2717                         if (threshold > max_threshold)
2718                                 threshold = max_threshold;
2719
2720                         iterations = n_blocks / 16 + 1;
2721                         if (iterations > 100)
2722                                 iterations = 100;
2723                 }
2724
2725                 for (i = 0;
2726                      i < iterations &&
2727                      (dev->gc_dirtiest < 1 ||
2728                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2729                      i++) {
2730                         dev->gc_block_finder++;
2731                         if (dev->gc_block_finder < dev->internal_start_block ||
2732                             dev->gc_block_finder > dev->internal_end_block)
2733                                 dev->gc_block_finder =
2734                                     dev->internal_start_block;
2735
2736                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2737
2738                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2739
2740                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2741                             pages_used < dev->param.chunks_per_block &&
2742                             (dev->gc_dirtiest < 1 ||
2743                              pages_used < dev->gc_pages_in_use) &&
2744                             yaffs_block_ok_for_gc(dev, bi)) {
2745                                 dev->gc_dirtiest = dev->gc_block_finder;
2746                                 dev->gc_pages_in_use = pages_used;
2747                         }
2748                 }
2749
2750                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2751                         selected = dev->gc_dirtiest;
2752         }
2753
2754         /*
2755          * If nothing has been selected for a while, try the oldest dirty
2756          * because that's gumming up the works.
2757          */
2758
2759         if (!selected && dev->param.is_yaffs2 &&
2760             dev->gc_not_done >= (background ? 10 : 20)) {
2761                 yaffs2_find_oldest_dirty_seq(dev);
2762                 if (dev->oldest_dirty_block > 0) {
2763                         selected = dev->oldest_dirty_block;
2764                         dev->gc_dirtiest = selected;
2765                         dev->oldest_dirty_gc_count++;
2766                         bi = yaffs_get_block_info(dev, selected);
2767                         dev->gc_pages_in_use =
2768                             bi->pages_in_use - bi->soft_del_pages;
2769                 } else {
2770                         dev->gc_not_done = 0;
2771                 }
2772         }
2773
2774         if (selected) {
2775                 yaffs_trace(YAFFS_TRACE_GC,
2776                         "GC Selected block %d with %d free, prioritised:%d",
2777                         selected,
2778                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2779                         prioritised);
2780
2781                 dev->n_gc_blocks++;
2782                 if (background)
2783                         dev->bg_gcs++;
2784
2785                 dev->gc_dirtiest = 0;
2786                 dev->gc_pages_in_use = 0;
2787                 dev->gc_not_done = 0;
2788                 if (dev->refresh_skip > 0)
2789                         dev->refresh_skip--;
2790         } else {
2791                 dev->gc_not_done++;
2792                 yaffs_trace(YAFFS_TRACE_GC,
2793                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2794                         dev->gc_block_finder, dev->gc_not_done, threshold,
2795                         dev->gc_dirtiest, dev->gc_pages_in_use,
2796                         dev->oldest_dirty_block, background ? " bg" : "");
2797         }
2798
2799         return selected;
2800 }
2801
2802 /* New garbage collector
2803  * If we're very low on erased blocks then we do aggressive garbage collection
2804  * otherwise we do "leasurely" garbage collection.
2805  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2806  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2807  *
2808  * The idea is to help clear out space in a more spread-out manner.
2809  * Dunno if it really does anything useful.
2810  */
2811 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2812 {
2813         int aggressive = 0;
2814         int gc_ok = YAFFS_OK;
2815         int max_tries = 0;
2816         int min_erased;
2817         int erased_chunks;
2818         int checkpt_block_adjust;
2819
2820         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2821                 return YAFFS_OK;
2822
2823         if (dev->gc_disable)
2824                 /* Bail out so we don't get recursive gc */
2825                 return YAFFS_OK;
2826
2827         /* This loop should pass the first time.
2828          * Only loops here if the collection does not increase space.
2829          */
2830
2831         do {
2832                 max_tries++;
2833
2834                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2835
2836                 min_erased =
2837                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2838                 erased_chunks =
2839                     dev->n_erased_blocks * dev->param.chunks_per_block;
2840
2841                 /* If we need a block soon then do aggressive gc. */
2842                 if (dev->n_erased_blocks < min_erased)
2843                         aggressive = 1;
2844                 else {
2845                         if (!background
2846                             && erased_chunks > (dev->n_free_chunks / 4))
2847                                 break;
2848
2849                         if (dev->gc_skip > 20)
2850                                 dev->gc_skip = 20;
2851                         if (erased_chunks < dev->n_free_chunks / 2 ||
2852                             dev->gc_skip < 1 || background)
2853                                 aggressive = 0;
2854                         else {
2855                                 dev->gc_skip--;
2856                                 break;
2857                         }
2858                 }
2859
2860                 dev->gc_skip = 5;
2861
2862                 /* If we don't already have a block being gc'd then see if we
2863                  * should start another */
2864
2865                 if (dev->gc_block < 1 && !aggressive) {
2866                         dev->gc_block = yaffs2_find_refresh_block(dev);
2867                         dev->gc_chunk = 0;
2868                         dev->n_clean_ups = 0;
2869                 }
2870                 if (dev->gc_block < 1) {
2871                         dev->gc_block =
2872                             yaffs_find_gc_block(dev, aggressive, background);
2873                         dev->gc_chunk = 0;
2874                         dev->n_clean_ups = 0;
2875                 }
2876
2877                 if (dev->gc_block > 0) {
2878                         dev->all_gcs++;
2879                         if (!aggressive)
2880                                 dev->passive_gc_count++;
2881
2882                         yaffs_trace(YAFFS_TRACE_GC,
2883                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2884                                 dev->n_erased_blocks, aggressive);
2885
2886                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2887                 }
2888
2889                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2890                     dev->gc_block > 0) {
2891                         yaffs_trace(YAFFS_TRACE_GC,
2892                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2893                                 dev->n_erased_blocks, max_tries,
2894                                 dev->gc_block);
2895                 }
2896         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2897                  (dev->gc_block > 0) && (max_tries < 2));
2898
2899         return aggressive ? gc_ok : YAFFS_OK;
2900 }
2901
2902 /*
2903  * yaffs_bg_gc()
2904  * Garbage collects. Intended to be called from a background thread.
2905  * Returns non-zero if at least half the free chunks are erased.
2906  */
2907 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2908 {
2909         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2910
2911         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2912
2913         yaffs_check_gc(dev, 1);
2914         return erased_chunks > dev->n_free_chunks / 2;
2915 }
2916
2917 /*-------------------- Data file manipulation -----------------*/
2918
2919 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2920 {
2921         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2922
2923         if (nand_chunk >= 0)
2924                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2925                                                 buffer, NULL);
2926         else {
2927                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2928                         "Chunk %d not found zero instead",
2929                         nand_chunk);
2930                 /* get sane (zero) data if you read a hole */
2931                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2932                 return 0;
2933         }
2934
2935 }
2936
2937 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2938                      int lyn)
2939 {
2940         int block;
2941         int page;
2942         struct yaffs_ext_tags tags;
2943         struct yaffs_block_info *bi;
2944
2945         if (chunk_id <= 0)
2946                 return;
2947
2948         dev->n_deletions++;
2949         block = chunk_id / dev->param.chunks_per_block;
2950         page = chunk_id % dev->param.chunks_per_block;
2951
2952         if (!yaffs_check_chunk_bit(dev, block, page))
2953                 yaffs_trace(YAFFS_TRACE_VERIFY,
2954                         "Deleting invalid chunk %d", chunk_id);
2955
2956         bi = yaffs_get_block_info(dev, block);
2957
2958         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2959
2960         yaffs_trace(YAFFS_TRACE_DELETION,
2961                 "line %d delete of chunk %d",
2962                 lyn, chunk_id);
2963
2964         if (!dev->param.is_yaffs2 && mark_flash &&
2965             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2966
2967                 memset(&tags, 0, sizeof(tags));
2968                 tags.is_deleted = 1;
2969                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2970                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2971         } else {
2972                 dev->n_unmarked_deletions++;
2973         }
2974
2975         /* Pull out of the management area.
2976          * If the whole block became dirty, this will kick off an erasure.
2977          */
2978         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2979             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2980             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2981             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2982                 dev->n_free_chunks++;
2983                 yaffs_clear_chunk_bit(dev, block, page);
2984                 bi->pages_in_use--;
2985
2986                 if (bi->pages_in_use == 0 &&
2987                     !bi->has_shrink_hdr &&
2988                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2989                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2990                         yaffs_block_became_dirty(dev, block);
2991                 }
2992         }
2993 }
2994
2995 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2996                              const u8 *buffer, int n_bytes, int use_reserve)
2997 {
2998         /* Find old chunk Need to do this to get serial number
2999          * Write new one and patch into tree.
3000          * Invalidate old tags.
3001          */
3002
3003         int prev_chunk_id;
3004         struct yaffs_ext_tags prev_tags;
3005         int new_chunk_id;
3006         struct yaffs_ext_tags new_tags;
3007         struct yaffs_dev *dev = in->my_dev;
3008
3009         yaffs_check_gc(dev, 0);
3010
3011         /* Get the previous chunk at this location in the file if it exists.
3012          * If it does not exist then put a zero into the tree. This creates
3013          * the tnode now, rather than later when it is harder to clean up.
3014          */
3015         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3016         if (prev_chunk_id < 1 &&
3017             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3018                 return 0;
3019
3020         /* Set up new tags */
3021         memset(&new_tags, 0, sizeof(new_tags));
3022
3023         new_tags.chunk_id = inode_chunk;
3024         new_tags.obj_id = in->obj_id;
3025         new_tags.serial_number =
3026             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3027         new_tags.n_bytes = n_bytes;
3028
3029         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3030                 yaffs_trace(YAFFS_TRACE_ERROR,
3031                   "Writing %d bytes to chunk!!!!!!!!!",
3032                    n_bytes);
3033                 BUG();
3034         }
3035
3036         new_chunk_id =
3037             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3038
3039         if (new_chunk_id > 0) {
3040                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3041
3042                 if (prev_chunk_id > 0)
3043                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3044
3045                 yaffs_verify_file_sane(in);
3046         }
3047         return new_chunk_id;
3048
3049 }
3050
3051
3052
3053 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3054                                 const YCHAR *name, const void *value, int size,
3055                                 int flags)
3056 {
3057         struct yaffs_xattr_mod xmod;
3058         int result;
3059
3060         xmod.set = set;
3061         xmod.name = name;
3062         xmod.data = value;
3063         xmod.size = size;
3064         xmod.flags = flags;
3065         xmod.result = -ENOSPC;
3066
3067         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3068
3069         if (result > 0)
3070                 return xmod.result;
3071         else
3072                 return -ENOSPC;
3073 }
3074
3075 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3076                                    struct yaffs_xattr_mod *xmod)
3077 {
3078         int retval = 0;
3079         int x_offs = sizeof(struct yaffs_obj_hdr);
3080         struct yaffs_dev *dev = obj->my_dev;
3081         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3082         char *x_buffer = buffer + x_offs;
3083
3084         if (xmod->set)
3085                 retval =
3086                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3087                              xmod->size, xmod->flags);
3088         else
3089                 retval = nval_del(x_buffer, x_size, xmod->name);
3090
3091         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3092         obj->xattr_known = 1;
3093         xmod->result = retval;
3094
3095         return retval;
3096 }
3097
3098 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3099                                   void *value, int size)
3100 {
3101         char *buffer = NULL;
3102         int result;
3103         struct yaffs_ext_tags tags;
3104         struct yaffs_dev *dev = obj->my_dev;
3105         int x_offs = sizeof(struct yaffs_obj_hdr);
3106         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3107         char *x_buffer;
3108         int retval = 0;
3109
3110         if (obj->hdr_chunk < 1)
3111                 return -ENODATA;
3112
3113         /* If we know that the object has no xattribs then don't do all the
3114          * reading and parsing.
3115          */
3116         if (obj->xattr_known && !obj->has_xattr) {
3117                 if (name)
3118                         return -ENODATA;
3119                 else
3120                         return 0;
3121         }
3122
3123         buffer = (char *)yaffs_get_temp_buffer(dev);
3124         if (!buffer)
3125                 return -ENOMEM;
3126
3127         result =
3128             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3129
3130         if (result != YAFFS_OK)
3131                 retval = -ENOENT;
3132         else {
3133                 x_buffer = buffer + x_offs;
3134
3135                 if (!obj->xattr_known) {
3136                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3137                         obj->xattr_known = 1;
3138                 }
3139
3140                 if (name)
3141                         retval = nval_get(x_buffer, x_size, name, value, size);
3142                 else
3143                         retval = nval_list(x_buffer, x_size, value, size);
3144         }
3145         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3146         return retval;
3147 }
3148
3149 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3150                       const void *value, int size, int flags)
3151 {
3152         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3153 }
3154
3155 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3156 {
3157         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3158 }
3159
3160 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3161                       int size)
3162 {
3163         return yaffs_do_xattrib_fetch(obj, name, value, size);
3164 }
3165
3166 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3167 {
3168         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3169 }
3170
3171 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3172 {
3173         u8 *buf;
3174         struct yaffs_obj_hdr *oh;
3175         struct yaffs_dev *dev;
3176         struct yaffs_ext_tags tags;
3177         int result;
3178         int alloc_failed = 0;
3179
3180         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3181                 return;
3182
3183         dev = in->my_dev;
3184         in->lazy_loaded = 0;
3185         buf = yaffs_get_temp_buffer(dev);
3186
3187         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3188         oh = (struct yaffs_obj_hdr *)buf;
3189
3190         in->yst_mode = oh->yst_mode;
3191         yaffs_load_attribs(in, oh);
3192         yaffs_set_obj_name_from_oh(in, oh);
3193
3194         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3195                 in->variant.symlink_variant.alias =
3196                     yaffs_clone_str(oh->alias);
3197                 if (!in->variant.symlink_variant.alias)
3198                         alloc_failed = 1;       /* Not returned */
3199         }
3200         yaffs_release_temp_buffer(dev, buf);
3201 }
3202
3203 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3204                                     const YCHAR *oh_name, int buff_size)
3205 {
3206 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3207         if (dev->param.auto_unicode) {
3208                 if (*oh_name) {
3209                         /* It is an ASCII name, do an ASCII to
3210                          * unicode conversion */
3211                         const char *ascii_oh_name = (const char *)oh_name;
3212                         int n = buff_size - 1;
3213                         while (n > 0 && *ascii_oh_name) {
3214                                 *name = *ascii_oh_name;
3215                                 name++;
3216                                 ascii_oh_name++;
3217                                 n--;
3218                         }
3219                 } else {
3220                         strncpy(name, oh_name + 1, buff_size - 1);
3221                 }
3222         } else {
3223 #else
3224         dev = dev;
3225         {
3226 #endif
3227                 strncpy(name, oh_name, buff_size - 1);
3228         }
3229 }
3230
3231 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3232                                     const YCHAR *name)
3233 {
3234 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3235
3236         int is_ascii;
3237         YCHAR *w;
3238
3239         if (dev->param.auto_unicode) {
3240
3241                 is_ascii = 1;
3242                 w = name;
3243
3244                 /* Figure out if the name will fit in ascii character set */
3245                 while (is_ascii && *w) {
3246                         if ((*w) & 0xff00)
3247                                 is_ascii = 0;
3248                         w++;
3249                 }
3250
3251                 if (is_ascii) {
3252                         /* It is an ASCII name, so convert unicode to ascii */
3253                         char *ascii_oh_name = (char *)oh_name;
3254                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3255                         while (n > 0 && *name) {
3256                                 *ascii_oh_name = *name;
3257                                 name++;
3258                                 ascii_oh_name++;
3259                                 n--;
3260                         }
3261                 } else {
3262                         /* Unicode name, so save starting at the second YCHAR */
3263                         *oh_name = 0;
3264                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3265                 }
3266         } else {
3267 #else
3268         dev = dev;
3269         {
3270 #endif
3271                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3272         }
3273 }
3274
3275 /* UpdateObjectHeader updates the header on NAND for an object.
3276  * If name is not NULL, then that new name is used.
3277  */
3278 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3279                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3280 {
3281
3282         struct yaffs_block_info *bi;
3283         struct yaffs_dev *dev = in->my_dev;
3284         int prev_chunk_id;
3285         int ret_val = 0;
3286         int result = 0;
3287         int new_chunk_id;
3288         struct yaffs_ext_tags new_tags;
3289         struct yaffs_ext_tags old_tags;
3290         const YCHAR *alias = NULL;
3291         u8 *buffer = NULL;
3292         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3293         struct yaffs_obj_hdr *oh = NULL;
3294         loff_t file_size = 0;
3295
3296         strcpy(old_name, _Y("silly old name"));
3297
3298         if (in->fake && in != dev->root_dir && !force && !xmod)
3299                 return ret_val;
3300
3301         yaffs_check_gc(dev, 0);
3302         yaffs_check_obj_details_loaded(in);
3303
3304         buffer = yaffs_get_temp_buffer(in->my_dev);
3305         oh = (struct yaffs_obj_hdr *)buffer;
3306
3307         prev_chunk_id = in->hdr_chunk;
3308
3309         if (prev_chunk_id > 0) {
3310                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3311                                                   buffer, &old_tags);
3312
3313                 yaffs_verify_oh(in, oh, &old_tags, 0);
3314                 memcpy(old_name, oh->name, sizeof(oh->name));
3315                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3316         } else {
3317                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3318         }
3319
3320         oh->type = in->variant_type;
3321         oh->yst_mode = in->yst_mode;
3322         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3323
3324         yaffs_load_attribs_oh(oh, in);
3325
3326         if (in->parent)
3327                 oh->parent_obj_id = in->parent->obj_id;
3328         else
3329                 oh->parent_obj_id = 0;
3330
3331         if (name && *name) {
3332                 memset(oh->name, 0, sizeof(oh->name));
3333                 yaffs_load_oh_from_name(dev, oh->name, name);
3334         } else if (prev_chunk_id > 0) {
3335                 memcpy(oh->name, old_name, sizeof(oh->name));
3336         } else {
3337                 memset(oh->name, 0, sizeof(oh->name));
3338         }
3339
3340         oh->is_shrink = is_shrink;
3341
3342         switch (in->variant_type) {
3343         case YAFFS_OBJECT_TYPE_UNKNOWN:
3344                 /* Should not happen */
3345                 break;
3346         case YAFFS_OBJECT_TYPE_FILE:
3347                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3348                      oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3349                      file_size = in->variant.file_variant.file_size;
3350                 yaffs_oh_size_load(oh, file_size);
3351                 break;
3352         case YAFFS_OBJECT_TYPE_HARDLINK:
3353                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3354                 break;
3355         case YAFFS_OBJECT_TYPE_SPECIAL:
3356                 /* Do nothing */
3357                 break;
3358         case YAFFS_OBJECT_TYPE_DIRECTORY:
3359                 /* Do nothing */
3360                 break;
3361         case YAFFS_OBJECT_TYPE_SYMLINK:
3362                 alias = in->variant.symlink_variant.alias;
3363                 if (!alias)
3364                         alias = _Y("no alias");
3365                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3366                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3367                 break;
3368         }
3369
3370         /* process any xattrib modifications */
3371         if (xmod)
3372                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3373
3374         /* Tags */
3375         memset(&new_tags, 0, sizeof(new_tags));
3376         in->serial++;
3377         new_tags.chunk_id = 0;
3378         new_tags.obj_id = in->obj_id;
3379         new_tags.serial_number = in->serial;
3380
3381         /* Add extra info for file header */
3382         new_tags.extra_available = 1;
3383         new_tags.extra_parent_id = oh->parent_obj_id;
3384         new_tags.extra_file_size = file_size;
3385         new_tags.extra_is_shrink = oh->is_shrink;
3386         new_tags.extra_equiv_id = oh->equiv_id;
3387         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3388         new_tags.extra_obj_type = in->variant_type;
3389         yaffs_verify_oh(in, oh, &new_tags, 1);
3390
3391         /* Create new chunk in NAND */
3392         new_chunk_id =
3393             yaffs_write_new_chunk(dev, buffer, &new_tags,
3394                                   (prev_chunk_id > 0) ? 1 : 0);
3395
3396         if (buffer)
3397                 yaffs_release_temp_buffer(dev, buffer);
3398
3399         if (new_chunk_id < 0)
3400                 return new_chunk_id;
3401
3402         in->hdr_chunk = new_chunk_id;
3403
3404         if (prev_chunk_id > 0)
3405                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3406
3407         if (!yaffs_obj_cache_dirty(in))
3408                 in->dirty = 0;
3409
3410         /* If this was a shrink, then mark the block
3411          * that the chunk lives on */
3412         if (is_shrink) {
3413                 bi = yaffs_get_block_info(in->my_dev,
3414                                           new_chunk_id /
3415                                           in->my_dev->param.chunks_per_block);
3416                 bi->has_shrink_hdr = 1;
3417         }
3418
3419
3420         return new_chunk_id;
3421 }