projects / openwrt / staging / yousong.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
kernel: update yaffs code
[openwrt/staging/yousong.git] / target / linux / generic / files / fs / yaffs2 / yaffs_yaffs2.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 "yaffs_guts.h"
15 #include "yaffs_trace.h"
16 #include "yaffs_yaffs2.h"
17 #include "yaffs_checkptrw.h"
18 #include "yaffs_bitmap.h"
19 #include "yaffs_nand.h"
20 #include "yaffs_getblockinfo.h"
21 #include "yaffs_verify.h"
22 #include "yaffs_attribs.h"
23 #include "yaffs_summary.h"
24
25 /*
26 * Checkpoints are really no benefit on very small partitions.
27 *
28 * To save space on small partitions don't bother with checkpoints unless
29 * the partition is at least this big.
30 */
31 #define YAFFS_CHECKPOINT_MIN_BLOCKS 60
32 #define YAFFS_SMALL_HOLE_THRESHOLD 4
33
34 /*
35 * Oldest Dirty Sequence Number handling.
36 */
37
38 /* yaffs_calc_oldest_dirty_seq()
39 * yaffs2_find_oldest_dirty_seq()
40 * Calculate the oldest dirty sequence number if we don't know it.
41 */
42 void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
43 {
44 int i;
45 unsigned seq;
46 unsigned block_no = 0;
47 struct yaffs_block_info *b;
48
49 if (!dev->param.is_yaffs2)
50 return;
51
52 /* Find the oldest dirty sequence number. */
53 seq = dev->seq_number + 1;
54 b = dev->block_info;
55 for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
56 if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
57 (b->pages_in_use - b->soft_del_pages) <
58 dev->param.chunks_per_block &&
59 b->seq_number < seq) {
60 seq = b->seq_number;
61 block_no = i;
62 }
63 b++;
64 }
65
66 if (block_no) {
67 dev->oldest_dirty_seq = seq;
68 dev->oldest_dirty_block = block_no;
69 }
70 }
71
72 void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
73 {
74 if (!dev->param.is_yaffs2)
75 return;
76
77 if (!dev->oldest_dirty_seq)
78 yaffs_calc_oldest_dirty_seq(dev);
79 }
80
81 /*
82 * yaffs_clear_oldest_dirty_seq()
83 * Called when a block is erased or marked bad. (ie. when its seq_number
84 * becomes invalid). If the value matches the oldest then we clear
85 * dev->oldest_dirty_seq to force its recomputation.
86 */
87 void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
88 struct yaffs_block_info *bi)
89 {
90
91 if (!dev->param.is_yaffs2)
92 return;
93
94 if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
95 dev->oldest_dirty_seq = 0;
96 dev->oldest_dirty_block = 0;
97 }
98 }
99
100 /*
101 * yaffs2_update_oldest_dirty_seq()
102 * Update the oldest dirty sequence number whenever we dirty a block.
103 * Only do this if the oldest_dirty_seq is actually being tracked.
104 */
105 void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
106 struct yaffs_block_info *bi)
107 {
108 if (!dev->param.is_yaffs2)
109 return;
110
111 if (dev->oldest_dirty_seq) {
112 if (dev->oldest_dirty_seq > bi->seq_number) {
113 dev->oldest_dirty_seq = bi->seq_number;
114 dev->oldest_dirty_block = block_no;
115 }
116 }
117 }
118
119 int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
120 {
121
122 if (!dev->param.is_yaffs2)
123 return 1; /* disqualification only applies to yaffs2. */
124
125 if (!bi->has_shrink_hdr)
126 return 1; /* can gc */
127
128 yaffs2_find_oldest_dirty_seq(dev);
129
130 /* Can't do gc of this block if there are any blocks older than this
131 * one that have discarded pages.
132 */
133 return (bi->seq_number <= dev->oldest_dirty_seq);
134 }
135
136 /*
137 * yaffs2_find_refresh_block()
138 * periodically finds the oldest full block by sequence number for refreshing.
139 * Only for yaffs2.
140 */
141 u32 yaffs2_find_refresh_block(struct yaffs_dev *dev)
142 {
143 u32 b;
144 u32 oldest = 0;
145 u32 oldest_seq = 0;
146 struct yaffs_block_info *bi;
147
148 if (!dev->param.is_yaffs2)
149 return oldest;
150
151 /*
152 * If refresh period < 10 then refreshing is disabled.
153 */
154 if (dev->param.refresh_period < 10)
155 return oldest;
156
157 /*
158 * Fix broken values.
159 */
160 if (dev->refresh_skip > dev->param.refresh_period)
161 dev->refresh_skip = dev->param.refresh_period;
162
163 if (dev->refresh_skip > 0)
164 return oldest;
165
166 /*
167 * Refresh skip is now zero.
168 * We'll do a refresh this time around....
169 * Update the refresh skip and find the oldest block.
170 */
171 dev->refresh_skip = dev->param.refresh_period;
172 dev->refresh_count++;
173 bi = dev->block_info;
174 for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
175
176 if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
177
178 if (oldest < 1 || bi->seq_number < oldest_seq) {
179 oldest = b;
180 oldest_seq = bi->seq_number;
181 }
182 }
183 bi++;
184 }
185
186 if (oldest > 0) {
187 yaffs_trace(YAFFS_TRACE_GC,
188 "GC refresh count %d selected block %d with seq_number %d",
189 dev->refresh_count, oldest, oldest_seq);
190 }
191
192 return oldest;
193 }
194
195 int yaffs2_checkpt_required(struct yaffs_dev *dev)
196 {
197 int nblocks;
198
199 if (!dev->param.is_yaffs2)
200 return 0;
201
202 nblocks = dev->internal_end_block - dev->internal_start_block + 1;
203
204 return !dev->param.skip_checkpt_wr &&
205 !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
206 }
207
208 int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
209 {
210 int retval;
211 int n_bytes = 0;
212 int n_blocks;
213 int dev_blocks;
214
215 if (!dev->param.is_yaffs2)
216 return 0;
217
218 if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
219 /* Not a valid value so recalculate */
220 dev_blocks = dev->param.end_block - dev->param.start_block + 1;
221 n_bytes += sizeof(struct yaffs_checkpt_validity);
222 n_bytes += sizeof(struct yaffs_checkpt_dev);
223 n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
224 n_bytes += dev_blocks * dev->chunk_bit_stride;
225 n_bytes +=
226 (sizeof(struct yaffs_checkpt_obj) + sizeof(u32)) *
227 dev->n_obj;
228 n_bytes += (dev->tnode_size + sizeof(u32)) * dev->n_tnodes;
229 n_bytes += sizeof(struct yaffs_checkpt_validity);
230 n_bytes += sizeof(u32); /* checksum */
231
232 /* Round up and add 2 blocks to allow for some bad blocks,
233 * so add 3 */
234
235 n_blocks =
236 (n_bytes /
237 (dev->data_bytes_per_chunk *
238 dev->param.chunks_per_block)) + 3;
239
240 dev->checkpoint_blocks_required = n_blocks;
241 }
242
243 retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
244 if (retval < 0)
245 retval = 0;
246 return retval;
247 }
248
249 /*--------------------- Checkpointing --------------------*/
250
251 static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
252 {
253 struct yaffs_checkpt_validity cp;
254
255 memset(&cp, 0, sizeof(cp));
256
257 cp.struct_type = sizeof(cp);
258 cp.magic = YAFFS_MAGIC;
259 cp.version = YAFFS_CHECKPOINT_VERSION;
260 cp.head = (head) ? 1 : 0;
261
262 return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
263 }
264
265 static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
266 {
267 struct yaffs_checkpt_validity cp;
268 int ok;
269
270 ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
271
272 if (ok)
273 ok = (cp.struct_type == sizeof(cp)) &&
274 (cp.magic == YAFFS_MAGIC) &&
275 (cp.version == YAFFS_CHECKPOINT_VERSION) &&
276 (cp.head == ((head) ? 1 : 0));
277 return ok ? 1 : 0;
278 }
279
280 static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
281 struct yaffs_dev *dev)
282 {
283 cp->n_erased_blocks = dev->n_erased_blocks;
284 cp->alloc_block = dev->alloc_block;
285 cp->alloc_page = dev->alloc_page;
286 cp->n_free_chunks = dev->n_free_chunks;
287
288 cp->n_deleted_files = dev->n_deleted_files;
289 cp->n_unlinked_files = dev->n_unlinked_files;
290 cp->n_bg_deletions = dev->n_bg_deletions;
291 cp->seq_number = dev->seq_number;
292
293 }
294
295 static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
296 struct yaffs_checkpt_dev *cp)
297 {
298 dev->n_erased_blocks = cp->n_erased_blocks;
299 dev->alloc_block = cp->alloc_block;
300 dev->alloc_page = cp->alloc_page;
301 dev->n_free_chunks = cp->n_free_chunks;
302
303 dev->n_deleted_files = cp->n_deleted_files;
304 dev->n_unlinked_files = cp->n_unlinked_files;
305 dev->n_bg_deletions = cp->n_bg_deletions;
306 dev->seq_number = cp->seq_number;
307 }
308
309 static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
310 {
311 struct yaffs_checkpt_dev cp;
312 u32 n_bytes;
313 u32 n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
314 int ok;
315
316 /* Write device runtime values */
317 yaffs2_dev_to_checkpt_dev(&cp, dev);
318 cp.struct_type = sizeof(cp);
319
320 ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
321 if (!ok)
322 return 0;
323
324 /* Write block info */
325 n_bytes = n_blocks * sizeof(struct yaffs_block_info);
326 ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) == n_bytes);
327 if (!ok)
328 return 0;
329
330 /* Write chunk bits */
331 n_bytes = n_blocks * dev->chunk_bit_stride;
332 ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) == n_bytes);
333
334 return ok ? 1 : 0;
335 }
336
337 static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
338 {
339 struct yaffs_checkpt_dev cp;
340 u32 n_bytes;
341 u32 n_blocks =
342 (dev->internal_end_block - dev->internal_start_block + 1);
343 int ok;
344
345 ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
346 if (!ok)
347 return 0;
348
349 if (cp.struct_type != sizeof(cp))
350 return 0;
351
352 yaffs_checkpt_dev_to_dev(dev, &cp);
353
354 n_bytes = n_blocks * sizeof(struct yaffs_block_info);
355
356 ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);
357
358 if (!ok)
359 return 0;
360
361 n_bytes = n_blocks * dev->chunk_bit_stride;
362
363 ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);
364
365 return ok ? 1 : 0;
366 }
367
368 static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
369 struct yaffs_obj *obj)
370 {
371 cp->obj_id = obj->obj_id;
372 cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
373 cp->hdr_chunk = obj->hdr_chunk;
374 cp->variant_type = obj->variant_type;
375 cp->deleted = obj->deleted;
376 cp->soft_del = obj->soft_del;
377 cp->unlinked = obj->unlinked;
378 cp->fake = obj->fake;
379 cp->rename_allowed = obj->rename_allowed;
380 cp->unlink_allowed = obj->unlink_allowed;
381 cp->serial = obj->serial;
382 cp->n_data_chunks = obj->n_data_chunks;
383
384 if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
385 cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
386 else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
387 cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
388 }
389
390 static int yaffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
391 struct yaffs_checkpt_obj *cp)
392 {
393 struct yaffs_obj *parent;
394
395 if (obj->variant_type != cp->variant_type) {
396 yaffs_trace(YAFFS_TRACE_ERROR,
397 "Checkpoint read object %d type %d chunk %d does not match existing object type %d",
398 cp->obj_id, cp->variant_type, cp->hdr_chunk,
399 obj->variant_type);
400 return 0;
401 }
402
403 obj->obj_id = cp->obj_id;
404
405 if (cp->parent_id)
406 parent = yaffs_find_or_create_by_number(obj->my_dev,
407 cp->parent_id,
408 YAFFS_OBJECT_TYPE_DIRECTORY);
409 else
410 parent = NULL;
411
412 if (parent) {
413 if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
414 yaffs_trace(YAFFS_TRACE_ALWAYS,
415 "Checkpoint read object %d parent %d type %d chunk %d Parent type, %d, not directory",
416 cp->obj_id, cp->parent_id,
417 cp->variant_type, cp->hdr_chunk,
418 parent->variant_type);
419 return 0;
420 }
421 yaffs_add_obj_to_dir(parent, obj);
422 }
423
424 obj->hdr_chunk = cp->hdr_chunk;
425 obj->variant_type = cp->variant_type;
426 obj->deleted = cp->deleted;
427 obj->soft_del = cp->soft_del;
428 obj->unlinked = cp->unlinked;
429 obj->fake = cp->fake;
430 obj->rename_allowed = cp->rename_allowed;
431 obj->unlink_allowed = cp->unlink_allowed;
432 obj->serial = cp->serial;
433 obj->n_data_chunks = cp->n_data_chunks;
434
435 if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
436 obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
437 else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
438 obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
439
440 if (obj->hdr_chunk > 0)
441 obj->lazy_loaded = 1;
442 return 1;
443 }
444
445 static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
446 struct yaffs_tnode *tn, u32 level,
447 int chunk_offset)
448 {
449 int i;
450 struct yaffs_dev *dev = in->my_dev;
451 int ok = 1;
452 u32 base_offset;
453
454 if (!tn)
455 return 1;
456
457 if (level > 0) {
458 for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
459 if (!tn->internal[i])
460 continue;
461 ok = yaffs2_checkpt_tnode_worker(in,
462 tn->internal[i],
463 level - 1,
464 (chunk_offset <<
465 YAFFS_TNODES_INTERNAL_BITS) + i);
466 }
467 return ok;
468 }
469
470 /* Level 0 tnode */
471 base_offset = chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
472 ok = (yaffs2_checkpt_wr(dev, &base_offset, sizeof(base_offset)) ==
473 sizeof(base_offset));
474 if (ok)
475 ok = (yaffs2_checkpt_wr(dev, tn, dev->tnode_size) ==
476 dev->tnode_size);
477
478 return ok;
479 }
480
481 static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
482 {
483 u32 end_marker = ~0;
484 int ok = 1;
485
486 if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
487 return ok;
488
489 ok = yaffs2_checkpt_tnode_worker(obj,
490 obj->variant.file_variant.top,
491 obj->variant.file_variant.
492 top_level, 0);
493 if (ok)
494 ok = (yaffs2_checkpt_wr(obj->my_dev, &end_marker,
495 sizeof(end_marker)) == sizeof(end_marker));
496
497 return ok ? 1 : 0;
498 }
499
500 static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
501 {
502 u32 base_chunk;
503 int ok = 1;
504 struct yaffs_dev *dev = obj->my_dev;
505 struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
506 struct yaffs_tnode *tn;
507 int nread = 0;
508
509 ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
510 sizeof(base_chunk));
511
512 while (ok && (~base_chunk)) {
513 nread++;
514 /* Read level 0 tnode */
515
516 tn = yaffs_get_tnode(dev);
517 if (tn)
518 ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
519 dev->tnode_size);
520 else
521 ok = 0;
522
523 if (tn && ok)
524 ok = yaffs_add_find_tnode_0(dev,
525 file_stuct_ptr,
526 base_chunk, tn) ? 1 : 0;
527
528 if (ok)
529 ok = (yaffs2_checkpt_rd
530 (dev, &base_chunk,
531 sizeof(base_chunk)) == sizeof(base_chunk));
532 }
533
534 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
535 "Checkpoint read tnodes %d records, last %d. ok %d",
536 nread, base_chunk, ok);
537
538 return ok ? 1 : 0;
539 }
540
541 static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
542 {
543 struct yaffs_obj *obj;
544 struct yaffs_checkpt_obj cp;
545 int i;
546 int ok = 1;
547 struct list_head *lh;
548
549 /* Iterate through the objects in each hash entry,
550 * dumping them to the checkpointing stream.
551 */
552
553 for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
554 list_for_each(lh, &dev->obj_bucket[i].list) {
555 obj = list_entry(lh, struct yaffs_obj, hash_link);
556 if (!obj->defered_free) {
557 yaffs2_obj_checkpt_obj(&cp, obj);
558 cp.struct_type = sizeof(cp);
559
560 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
561 "Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
562 cp.obj_id, cp.parent_id,
563 cp.variant_type, cp.hdr_chunk, obj);
564
565 ok = (yaffs2_checkpt_wr(dev, &cp,
566 sizeof(cp)) == sizeof(cp));
567
568 if (ok &&
569 obj->variant_type ==
570 YAFFS_OBJECT_TYPE_FILE)
571 ok = yaffs2_wr_checkpt_tnodes(obj);
572 }
573 }
574 }
575
576 /* Dump end of list */
577 memset(&cp, 0xff, sizeof(struct yaffs_checkpt_obj));
578 cp.struct_type = sizeof(cp);
579
580 if (ok)
581 ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
582
583 return ok ? 1 : 0;
584 }
585
586 static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
587 {
588 struct yaffs_obj *obj;
589 struct yaffs_checkpt_obj cp;
590 int ok = 1;
591 int done = 0;
592 LIST_HEAD(hard_list);
593
594
595 while (ok && !done) {
596 ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
597 if (cp.struct_type != sizeof(cp)) {
598 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
599 "struct size %d instead of %d ok %d",
600 cp.struct_type, (int)sizeof(cp), ok);
601 ok = 0;
602 }
603
604 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
605 "Checkpoint read object %d parent %d type %d chunk %d ",
606 cp.obj_id, cp.parent_id, cp.variant_type,
607 cp.hdr_chunk);
608
609 if (ok && cp.obj_id == ~0) {
610 done = 1;
611 } else if (ok) {
612 obj =
613 yaffs_find_or_create_by_number(dev, cp.obj_id,
614 cp.variant_type);
615 if (obj) {
616 ok = yaffs2_checkpt_obj_to_obj(obj, &cp);
617 if (!ok)
618 break;
619 if (obj->variant_type ==
620 YAFFS_OBJECT_TYPE_FILE) {
621 ok = yaffs2_rd_checkpt_tnodes(obj);
622 } else if (obj->variant_type ==
623 YAFFS_OBJECT_TYPE_HARDLINK) {
624 list_add(&obj->hard_links, &hard_list);
625 }
626 } else {
627 ok = 0;
628 }
629 }
630 }
631
632 if (ok)
633 yaffs_link_fixup(dev, &hard_list);
634
635 return ok ? 1 : 0;
636 }
637
638 static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
639 {
640 u32 checkpt_sum;
641 int ok;
642
643 yaffs2_get_checkpt_sum(dev, &checkpt_sum);
644
645 ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
646 sizeof(checkpt_sum));
647
648 if (!ok)
649 return 0;
650
651 return 1;
652 }
653
654 static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
655 {
656 u32 checkpt_sum0;
657 u32 checkpt_sum1;
658 int ok;
659
660 yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
661
662 ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
663 sizeof(checkpt_sum1));
664
665 if (!ok)
666 return 0;
667
668 if (checkpt_sum0 != checkpt_sum1)
669 return 0;
670
671 return 1;
672 }
673
674 static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
675 {
676 int ok = 1;
677
678 if (!yaffs2_checkpt_required(dev)) {
679 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
680 "skipping checkpoint write");
681 ok = 0;
682 }
683
684 if (ok)
685 ok = yaffs2_checkpt_open(dev, 1);
686
687 if (ok) {
688 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
689 "write checkpoint validity");
690 ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
691 }
692 if (ok) {
693 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
694 "write checkpoint device");
695 ok = yaffs2_wr_checkpt_dev(dev);
696 }
697 if (ok) {
698 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
699 "write checkpoint objects");
700 ok = yaffs2_wr_checkpt_objs(dev);
701 }
702 if (ok) {
703 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
704 "write checkpoint validity");
705 ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
706 }
707
708 if (ok)
709 ok = yaffs2_wr_checkpt_sum(dev);
710
711 if (!yaffs_checkpt_close(dev))
712 ok = 0;
713
714 if (ok)
715 dev->is_checkpointed = 1;
716 else
717 dev->is_checkpointed = 0;
718
719 return dev->is_checkpointed;
720 }
721
722 static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
723 {
724 int ok = 1;
725
726 if (!dev->param.is_yaffs2)
727 ok = 0;
728
729 if (ok && dev->param.skip_checkpt_rd) {
730 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
731 "skipping checkpoint read");
732 ok = 0;
733 }
734
735 if (ok)
736 ok = yaffs2_checkpt_open(dev, 0); /* open for read */
737
738 if (ok) {
739 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
740 "read checkpoint validity");
741 ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
742 }
743 if (ok) {
744 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
745 "read checkpoint device");
746 ok = yaffs2_rd_checkpt_dev(dev);
747 }
748 if (ok) {
749 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
750 "read checkpoint objects");
751 ok = yaffs2_rd_checkpt_objs(dev);
752 }
753 if (ok) {
754 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
755 "read checkpoint validity");
756 ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
757 }
758
759 if (ok) {
760 ok = yaffs2_rd_checkpt_sum(dev);
761 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
762 "read checkpoint checksum %d", ok);
763 }
764
765 if (!yaffs_checkpt_close(dev))
766 ok = 0;
767
768 if (ok)
769 dev->is_checkpointed = 1;
770 else
771 dev->is_checkpointed = 0;
772
773 return ok ? 1 : 0;
774 }
775
776 void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
777 {
778 if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
779 dev->is_checkpointed = 0;
780 yaffs2_checkpt_invalidate_stream(dev);
781 }
782 if (dev->param.sb_dirty_fn)
783 dev->param.sb_dirty_fn(dev);
784 }
785
786 int yaffs_checkpoint_save(struct yaffs_dev *dev)
787 {
788 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
789 "save entry: is_checkpointed %d",
790 dev->is_checkpointed);
791
792 yaffs_verify_objects(dev);
793 yaffs_verify_blocks(dev);
794 yaffs_verify_free_chunks(dev);
795
796 if (!dev->is_checkpointed) {
797 yaffs2_checkpt_invalidate(dev);
798 yaffs2_wr_checkpt_data(dev);
799 }
800
801 yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
802 "save exit: is_checkpointed %d",
803 dev->is_checkpointed);
804
805 return dev->is_checkpointed;
806 }
807
808 int yaffs2_checkpt_restore(struct yaffs_dev *dev)
809 {
810 int retval;
811
812 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
813 "restore entry: is_checkpointed %d",
814 dev->is_checkpointed);
815
816 retval = yaffs2_rd_checkpt_data(dev);
817
818 if (dev->is_checkpointed) {
819 yaffs_verify_objects(dev);
820 yaffs_verify_blocks(dev);
821 yaffs_verify_free_chunks(dev);
822 }
823
824 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
825 "restore exit: is_checkpointed %d",
826 dev->is_checkpointed);
827
828 return retval;
829 }
830
831 int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
832 {
833 /* if new_size > old_file_size.
834 * We're going to be writing a hole.
835 * If the hole is small then write zeros otherwise write a start
836 * of hole marker.
837 */
838 loff_t old_file_size;
839 loff_t increase;
840 int small_hole;
841 int result = YAFFS_OK;
842 struct yaffs_dev *dev = NULL;
843 u8 *local_buffer = NULL;
844 int small_increase_ok = 0;
845
846 if (!obj)
847 return YAFFS_FAIL;
848
849 if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
850 return YAFFS_FAIL;
851
852 dev = obj->my_dev;
853
854 /* Bail out if not yaffs2 mode */
855 if (!dev->param.is_yaffs2)
856 return YAFFS_OK;
857
858 old_file_size = obj->variant.file_variant.file_size;
859
860 if (new_size <= old_file_size)
861 return YAFFS_OK;
862
863 increase = new_size - old_file_size;
864
865 if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
866 yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
867 small_hole = 1;
868 else
869 small_hole = 0;
870
871 if (small_hole)
872 local_buffer = yaffs_get_temp_buffer(dev);
873
874 if (local_buffer) {
875 /* fill hole with zero bytes */
876 loff_t pos = old_file_size;
877 int this_write;
878 int written;
879 memset(local_buffer, 0, dev->data_bytes_per_chunk);
880 small_increase_ok = 1;
881
882 while (increase > 0 && small_increase_ok) {
883 this_write = increase;
884 if (this_write > dev->data_bytes_per_chunk)
885 this_write = dev->data_bytes_per_chunk;
886 written =
887 yaffs_do_file_wr(obj, local_buffer, pos, this_write,
888 0);
889 if (written == this_write) {
890 pos += this_write;
891 increase -= this_write;
892 } else {
893 small_increase_ok = 0;
894 }
895 }
896
897 yaffs_release_temp_buffer(dev, local_buffer);
898
899 /* If out of space then reverse any chunks we've added */
900 if (!small_increase_ok)
901 yaffs_resize_file_down(obj, old_file_size);
902 }
903
904 if (!small_increase_ok &&
905 obj->parent &&
906 obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
907 obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
908 /* Write a hole start header with the old file size */
909 yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
910 }
911
912 return result;
913 }
914
915 struct yaffs_block_index {
916 int seq;
917 int block;
918 };
919
920 static int yaffs2_ybicmp(const void *a, const void *b)
921 {
922 int aseq = ((struct yaffs_block_index *)a)->seq;
923 int bseq = ((struct yaffs_block_index *)b)->seq;
924 int ablock = ((struct yaffs_block_index *)a)->block;
925 int bblock = ((struct yaffs_block_index *)b)->block;
926
927 if (aseq == bseq)
928 return ablock - bblock;
929
930 return aseq - bseq;
931 }
932
933 static inline int yaffs2_scan_chunk(struct yaffs_dev *dev,
934 struct yaffs_block_info *bi,
935 int blk, int chunk_in_block,
936 int *found_chunks,
937 u8 *chunk_data,
938 struct list_head *hard_list,
939 int summary_available)
940 {
941 struct yaffs_obj_hdr *oh;
942 struct yaffs_obj *in;
943 struct yaffs_obj *parent;
944 int equiv_id;
945 loff_t file_size;
946 int is_shrink;
947 int is_unlinked;
948 struct yaffs_ext_tags tags;
949 int result;
950 int alloc_failed = 0;
951 int chunk = blk * dev->param.chunks_per_block + chunk_in_block;
952 struct yaffs_file_var *file_var;
953 struct yaffs_hardlink_var *hl_var;
954 struct yaffs_symlink_var *sl_var;
955
956 if (summary_available) {
957 result = yaffs_summary_fetch(dev, &tags, chunk_in_block);
958 tags.seq_number = bi->seq_number;
959 }
960
961 if (!summary_available || tags.obj_id == 0) {
962 result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags);
963 dev->tags_used++;
964 } else {
965 dev->summary_used++;
966 }
967
968 /* Let's have a good look at this chunk... */
969
970 if (!tags.chunk_used) {
971 /* An unassigned chunk in the block.
972 * If there are used chunks after this one, then
973 * it is a chunk that was skipped due to failing
974 * the erased check. Just skip it so that it can
975 * be deleted.
976 * But, more typically, We get here when this is
977 * an unallocated chunk and his means that
978 * either the block is empty or this is the one
979 * being allocated from
980 */
981
982 if (*found_chunks) {
983 /* This is a chunk that was skipped due
984 * to failing the erased check */
985 } else if (chunk_in_block == 0) {
986 /* We're looking at the first chunk in
987 * the block so the block is unused */
988 bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
989 dev->n_erased_blocks++;
990 } else {
991 if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
992 bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
993 if (dev->seq_number == bi->seq_number) {
994 /* Allocating from this block*/
995 yaffs_trace(YAFFS_TRACE_SCAN,
996 " Allocating from %d %d",
997 blk, chunk_in_block);
998
999 bi->block_state =
1000 YAFFS_BLOCK_STATE_ALLOCATING;
1001 dev->alloc_block = blk;
1002 dev->alloc_page = chunk_in_block;
1003 dev->alloc_block_finder = blk;
1004 } else {
1005 /* This is a partially written block
1006 * that is not the current
1007 * allocation block.
1008 */
1009 yaffs_trace(YAFFS_TRACE_SCAN,
1010 "Partially written block %d detected. gc will fix this.",
1011 blk);
1012 }
1013 }
1014 }
1015
1016 dev->n_free_chunks++;
1017
1018 } else if (tags.ecc_result ==
1019 YAFFS_ECC_RESULT_UNFIXED) {
1020 yaffs_trace(YAFFS_TRACE_SCAN,
1021 " Unfixed ECC in chunk(%d:%d), chunk ignored",
1022 blk, chunk_in_block);
1023 dev->n_free_chunks++;
1024 } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
1025 tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
1026 tags.obj_id == YAFFS_OBJECTID_SUMMARY ||
1027 (tags.chunk_id > 0 &&
1028 tags.n_bytes > dev->data_bytes_per_chunk) ||
1029 tags.seq_number != bi->seq_number) {
1030 yaffs_trace(YAFFS_TRACE_SCAN,
1031 "Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored",
1032 blk, chunk_in_block, tags.obj_id,
1033 tags.chunk_id, tags.n_bytes);
1034 dev->n_free_chunks++;
1035 } else if (tags.chunk_id > 0) {
1036 /* chunk_id > 0 so it is a data chunk... */
1037 loff_t endpos;
1038 loff_t chunk_base = (tags.chunk_id - 1) *
1039 dev->data_bytes_per_chunk;
1040
1041 *found_chunks = 1;
1042
1043 yaffs_set_chunk_bit(dev, blk, chunk_in_block);
1044 bi->pages_in_use++;
1045
1046 in = yaffs_find_or_create_by_number(dev,
1047 tags.obj_id,
1048 YAFFS_OBJECT_TYPE_FILE);
1049 if (!in)
1050 /* Out of memory */
1051 alloc_failed = 1;
1052
1053 if (in &&
1054 in->variant_type == YAFFS_OBJECT_TYPE_FILE &&
1055 chunk_base < in->variant.file_variant.shrink_size) {
1056 /* This has not been invalidated by
1057 * a resize */
1058 if (!yaffs_put_chunk_in_file(in, tags.chunk_id,
1059 chunk, -1))
1060 alloc_failed = 1;
1061
1062 /* File size is calculated by looking at
1063 * the data chunks if we have not
1064 * seen an object header yet.
1065 * Stop this practice once we find an
1066 * object header.
1067 */
1068 endpos = chunk_base + tags.n_bytes;
1069
1070 if (!in->valid &&
1071 in->variant.file_variant.scanned_size < endpos) {
1072 in->variant.file_variant.
1073 scanned_size = endpos;
1074 in->variant.file_variant.
1075 file_size = endpos;
1076 }
1077 } else if (in) {
1078 /* This chunk has been invalidated by a
1079 * resize, or a past file deletion
1080 * so delete the chunk*/
1081 yaffs_chunk_del(dev, chunk, 1, __LINE__);
1082 }
1083 } else {
1084 /* chunk_id == 0, so it is an ObjectHeader.
1085 * Thus, we read in the object header and make
1086 * the object
1087 */
1088 *found_chunks = 1;
1089
1090 yaffs_set_chunk_bit(dev, blk, chunk_in_block);
1091 bi->pages_in_use++;
1092
1093 oh = NULL;
1094 in = NULL;
1095
1096 if (tags.extra_available) {
1097 in = yaffs_find_or_create_by_number(dev,
1098 tags.obj_id,
1099 tags.extra_obj_type);
1100 if (!in)
1101 alloc_failed = 1;
1102 }
1103
1104 if (!in ||
1105 (!in->valid && dev->param.disable_lazy_load) ||
1106 tags.extra_shadows ||
1107 (!in->valid && (tags.obj_id == YAFFS_OBJECTID_ROOT ||
1108 tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND))) {
1109
1110 /* If we don't have valid info then we
1111 * need to read the chunk
1112 * TODO In future we can probably defer
1113 * reading the chunk and living with
1114 * invalid data until needed.
1115 */
1116
1117 result = yaffs_rd_chunk_tags_nand(dev,
1118 chunk,
1119 chunk_data,
1120 NULL);
1121
1122 oh = (struct yaffs_obj_hdr *)chunk_data;
1123
1124 if (dev->param.inband_tags) {
1125 /* Fix up the header if they got
1126 * corrupted by inband tags */
1127 oh->shadows_obj =
1128 oh->inband_shadowed_obj_id;
1129 oh->is_shrink =
1130 oh->inband_is_shrink;
1131 }
1132
1133 if (!in) {
1134 in = yaffs_find_or_create_by_number(dev,
1135 tags.obj_id, oh->type);
1136 if (!in)
1137 alloc_failed = 1;
1138 }
1139 }
1140
1141 if (!in) {
1142 /* TODO Hoosterman we have a problem! */
1143 yaffs_trace(YAFFS_TRACE_ERROR,
1144 "yaffs tragedy: Could not make object for object %d at chunk %d during scan",
1145 tags.obj_id, chunk);
1146 return YAFFS_FAIL;
1147 }
1148
1149 if (in->valid) {
1150 /* We have already filled this one.
1151 * We have a duplicate that will be
1152 * discarded, but we first have to suck
1153 * out resize info if it is a file.
1154 */
1155 if ((in->variant_type == YAFFS_OBJECT_TYPE_FILE) &&
1156 ((oh && oh->type == YAFFS_OBJECT_TYPE_FILE) ||
1157 (tags.extra_available &&
1158 tags.extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
1159 )) {
1160 loff_t this_size = (oh) ?
1161 yaffs_oh_to_size(oh) :
1162 tags.extra_file_size;
1163 u32 parent_obj_id = (oh) ?
1164 oh->parent_obj_id :
1165 tags.extra_parent_id;
1166
1167 is_shrink = (oh) ?
1168 oh->is_shrink :
1169 tags.extra_is_shrink;
1170
1171 /* If it is deleted (unlinked
1172 * at start also means deleted)
1173 * we treat the file size as
1174 * being zeroed at this point.
1175 */
1176 if (parent_obj_id == YAFFS_OBJECTID_DELETED ||
1177 parent_obj_id == YAFFS_OBJECTID_UNLINKED) {
1178 this_size = 0;
1179 is_shrink = 1;
1180 }
1181
1182 if (is_shrink &&
1183 in->variant.file_variant.shrink_size >
1184 this_size)
1185 in->variant.file_variant.shrink_size =
1186 this_size;
1187
1188 if (is_shrink)
1189 bi->has_shrink_hdr = 1;
1190 }
1191 /* Use existing - destroy this one. */
1192 yaffs_chunk_del(dev, chunk, 1, __LINE__);
1193 }
1194
1195 if (!in->valid && in->variant_type !=
1196 (oh ? oh->type : tags.extra_obj_type))
1197 yaffs_trace(YAFFS_TRACE_ERROR,
1198 "yaffs tragedy: Bad object type, %d != %d, for object %d at chunk %d during scan",
1199 oh ? oh->type : tags.extra_obj_type,
1200 in->variant_type, tags.obj_id,
1201 chunk);
1202
1203 if (!in->valid &&
1204 (tags.obj_id == YAFFS_OBJECTID_ROOT ||
1205 tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND)) {
1206 /* We only load some info, don't fiddle
1207 * with directory structure */
1208 in->valid = 1;
1209
1210 if (oh) {
1211 in->yst_mode = oh->yst_mode;
1212 yaffs_load_attribs(in, oh);
1213 in->lazy_loaded = 0;
1214 } else {
1215 in->lazy_loaded = 1;
1216 }
1217 in->hdr_chunk = chunk;
1218
1219 } else if (!in->valid) {
1220 /* we need to load this info */
1221 in->valid = 1;
1222 in->hdr_chunk = chunk;
1223 if (oh) {
1224 in->variant_type = oh->type;
1225 in->yst_mode = oh->yst_mode;
1226 yaffs_load_attribs(in, oh);
1227
1228 if (oh->shadows_obj > 0)
1229 yaffs_handle_shadowed_obj(dev,
1230 oh->shadows_obj, 1);
1231
1232 yaffs_set_obj_name_from_oh(in, oh);
1233 parent = yaffs_find_or_create_by_number(dev,
1234 oh->parent_obj_id,
1235 YAFFS_OBJECT_TYPE_DIRECTORY);
1236 file_size = yaffs_oh_to_size(oh);
1237 is_shrink = oh->is_shrink;
1238 equiv_id = oh->equiv_id;
1239 } else {
1240 in->variant_type = tags.extra_obj_type;
1241 parent = yaffs_find_or_create_by_number(dev,
1242 tags.extra_parent_id,
1243 YAFFS_OBJECT_TYPE_DIRECTORY);
1244 file_size = tags.extra_file_size;
1245 is_shrink = tags.extra_is_shrink;
1246 equiv_id = tags.extra_equiv_id;
1247 in->lazy_loaded = 1;
1248 }
1249 in->dirty = 0;
1250
1251 if (!parent)
1252 alloc_failed = 1;
1253
1254 /* directory stuff...
1255 * hook up to parent
1256 */
1257
1258 if (parent &&
1259 parent->variant_type == YAFFS_OBJECT_TYPE_UNKNOWN) {
1260 /* Set up as a directory */
1261 parent->variant_type =
1262 YAFFS_OBJECT_TYPE_DIRECTORY;
1263 INIT_LIST_HEAD(&parent->
1264 variant.dir_variant.children);
1265 } else if (!parent ||
1266 parent->variant_type !=
1267 YAFFS_OBJECT_TYPE_DIRECTORY) {
1268 /* Hoosterman, another problem....
1269 * Trying to use a non-directory as a directory
1270 */
1271
1272 yaffs_trace(YAFFS_TRACE_ERROR,
1273 "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
1274 );
1275 parent = dev->lost_n_found;
1276 }
1277 yaffs_add_obj_to_dir(parent, in);
1278
1279 is_unlinked = (parent == dev->del_dir) ||
1280 (parent == dev->unlinked_dir);
1281
1282 if (is_shrink)
1283 /* Mark the block */
1284 bi->has_shrink_hdr = 1;
1285
1286 /* Note re hardlinks.
1287 * Since we might scan a hardlink before its equivalent
1288 * object is scanned we put them all in a list.
1289 * After scanning is complete, we should have all the
1290 * objects, so we run through this list and fix up all
1291 * the chains.
1292 */
1293
1294 switch (in->variant_type) {
1295 case YAFFS_OBJECT_TYPE_UNKNOWN:
1296 /* Todo got a problem */
1297 break;
1298 case YAFFS_OBJECT_TYPE_FILE:
1299 file_var = &in->variant.file_variant;
1300 if (file_var->scanned_size < file_size) {
1301 /* This covers the case where the file
1302 * size is greater than the data held.
1303 * This will happen if the file is
1304 * resized to be larger than its
1305 * current data extents.
1306 */
1307 file_var->file_size = file_size;
1308 file_var->scanned_size = file_size;
1309 }
1310
1311 if (file_var->shrink_size > file_size)
1312 file_var->shrink_size = file_size;
1313
1314 break;
1315 case YAFFS_OBJECT_TYPE_HARDLINK:
1316 hl_var = &in->variant.hardlink_variant;
1317 if (!is_unlinked) {
1318 hl_var->equiv_id = equiv_id;
1319 list_add(&in->hard_links, hard_list);
1320 }
1321 break;
1322 case YAFFS_OBJECT_TYPE_DIRECTORY:
1323 /* Do nothing */
1324 break;
1325 case YAFFS_OBJECT_TYPE_SPECIAL:
1326 /* Do nothing */
1327 break;
1328 case YAFFS_OBJECT_TYPE_SYMLINK:
1329 sl_var = &in->variant.symlink_variant;
1330 if (oh) {
1331 sl_var->alias =
1332 yaffs_clone_str(oh->alias);
1333 if (!sl_var->alias)
1334 alloc_failed = 1;
1335 }
1336 break;
1337 }
1338 }
1339 }
1340 return alloc_failed ? YAFFS_FAIL : YAFFS_OK;
1341 }
1342
1343 int yaffs2_scan_backwards(struct yaffs_dev *dev)
1344 {
1345 int blk;
1346 int block_iter;
1347 int start_iter;
1348 int end_iter;
1349 int n_to_scan = 0;
1350 enum yaffs_block_state state;
1351 int c;
1352 int deleted;
1353 LIST_HEAD(hard_list);
1354 struct yaffs_block_info *bi;
1355 u32 seq_number;
1356 int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
1357 u8 *chunk_data;
1358 int found_chunks;
1359 int alloc_failed = 0;
1360 struct yaffs_block_index *block_index = NULL;
1361 int alt_block_index = 0;
1362 int summary_available;
1363
1364 yaffs_trace(YAFFS_TRACE_SCAN,
1365 "yaffs2_scan_backwards starts intstartblk %d intendblk %d...",
1366 dev->internal_start_block, dev->internal_end_block);
1367
1368 dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
1369
1370 block_index =
1371 kmalloc(n_blocks * sizeof(struct yaffs_block_index), GFP_NOFS);
1372
1373 if (!block_index) {
1374 block_index =
1375 vmalloc(n_blocks * sizeof(struct yaffs_block_index));
1376 alt_block_index = 1;
1377 }
1378
1379 if (!block_index) {
1380 yaffs_trace(YAFFS_TRACE_SCAN,
1381 "yaffs2_scan_backwards() could not allocate block index!"
1382 );
1383 return YAFFS_FAIL;
1384 }
1385
1386 dev->blocks_in_checkpt = 0;
1387
1388 chunk_data = yaffs_get_temp_buffer(dev);
1389
1390 /* Scan all the blocks to determine their state */
1391 bi = dev->block_info;
1392 for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
1393 blk++) {
1394 yaffs_clear_chunk_bits(dev, blk);
1395 bi->pages_in_use = 0;
1396 bi->soft_del_pages = 0;
1397
1398 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
1399
1400 bi->block_state = state;
1401 bi->seq_number = seq_number;
1402
1403 if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
1404 bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
1405 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
1406 bi->block_state = YAFFS_BLOCK_STATE_DEAD;
1407
1408 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
1409 "Block scanning block %d state %d seq %d",
1410 blk, bi->block_state, seq_number);
1411
1412 if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
1413 dev->blocks_in_checkpt++;
1414
1415 } else if (bi->block_state == YAFFS_BLOCK_STATE_DEAD) {
1416 yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
1417 "block %d is bad", blk);
1418 } else if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
1419 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
1420 dev->n_erased_blocks++;
1421 dev->n_free_chunks += dev->param.chunks_per_block;
1422 } else if (bi->block_state ==
1423 YAFFS_BLOCK_STATE_NEEDS_SCAN) {
1424 /* Determine the highest sequence number */
1425 if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
1426 seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
1427 block_index[n_to_scan].seq = seq_number;
1428 block_index[n_to_scan].block = blk;
1429 n_to_scan++;
1430 if (seq_number >= dev->seq_number)
1431 dev->seq_number = seq_number;
1432 } else {
1433 /* TODO: Nasty sequence number! */
1434 yaffs_trace(YAFFS_TRACE_SCAN,
1435 "Block scanning block %d has bad sequence number %d",
1436 blk, seq_number);
1437 }
1438 }
1439 bi++;
1440 }
1441
1442 yaffs_trace(YAFFS_TRACE_SCAN, "%d blocks to be sorted...", n_to_scan);
1443
1444 cond_resched();
1445
1446 /* Sort the blocks by sequence number */
1447 sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
1448 yaffs2_ybicmp, NULL);
1449
1450 cond_resched();
1451
1452 yaffs_trace(YAFFS_TRACE_SCAN, "...done");
1453
1454 /* Now scan the blocks looking at the data. */
1455 start_iter = 0;
1456 end_iter = n_to_scan - 1;
1457 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "%d blocks to scan", n_to_scan);
1458
1459 /* For each block.... backwards */
1460 for (block_iter = end_iter;
1461 !alloc_failed && block_iter >= start_iter;
1462 block_iter--) {
1463 /* Cooperative multitasking! This loop can run for so
1464 long that watchdog timers expire. */
1465 cond_resched();
1466
1467 /* get the block to scan in the correct order */
1468 blk = block_index[block_iter].block;
1469 bi = yaffs_get_block_info(dev, blk);
1470 deleted = 0;
1471
1472 summary_available = yaffs_summary_read(dev, dev->sum_tags, blk);
1473
1474 /* For each chunk in each block that needs scanning.... */
1475 found_chunks = 0;
1476 if (summary_available)
1477 c = dev->chunks_per_summary - 1;
1478 else
1479 c = dev->param.chunks_per_block - 1;
1480
1481 for (/* c is already initialised */;
1482 !alloc_failed && c >= 0 &&
1483 (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
1484 bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING);
1485 c--) {
1486 /* Scan backwards...
1487 * Read the tags and decide what to do
1488 */
1489 if (yaffs2_scan_chunk(dev, bi, blk, c,
1490 &found_chunks, chunk_data,
1491 &hard_list, summary_available) ==
1492 YAFFS_FAIL)
1493 alloc_failed = 1;
1494 }
1495
1496 if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
1497 /* If we got this far while scanning, then the block
1498 * is fully allocated. */
1499 bi->block_state = YAFFS_BLOCK_STATE_FULL;
1500 }
1501
1502 /* Now let's see if it was dirty */
1503 if (bi->pages_in_use == 0 &&
1504 !bi->has_shrink_hdr &&
1505 bi->block_state == YAFFS_BLOCK_STATE_FULL) {
1506 yaffs_block_became_dirty(dev, blk);
1507 }
1508 }
1509
1510 yaffs_skip_rest_of_block(dev);
1511
1512 if (alt_block_index)
1513 vfree(block_index);
1514 else
1515 kfree(block_index);
1516
1517 /* Ok, we've done all the scanning.
1518 * Fix up the hard link chains.
1519 * We have scanned all the objects, now it's time to add these
1520 * hardlinks.
1521 */
1522 yaffs_link_fixup(dev, &hard_list);
1523
1524 yaffs_release_temp_buffer(dev, chunk_data);
1525
1526 if (alloc_failed)
1527 return YAFFS_FAIL;
1528
1529 yaffs_trace(YAFFS_TRACE_SCAN, "yaffs2_scan_backwards ends");
1530
1531 return YAFFS_OK;
1532 }
Yousong Zhou staging tree