]>
Commit | Line | Data |
---|---|---|
1 | // SPDX-License-Identifier: GPL-2.0+ | |
2 | /* | |
3 | * recovery.c - NILFS recovery logic | |
4 | * | |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. | |
6 | * | |
7 | * Written by Ryusuke Konishi. | |
8 | */ | |
9 | ||
10 | #include <linux/buffer_head.h> | |
11 | #include <linux/blkdev.h> | |
12 | #include <linux/swap.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/crc32.h> | |
15 | #include "nilfs.h" | |
16 | #include "segment.h" | |
17 | #include "sufile.h" | |
18 | #include "page.h" | |
19 | #include "segbuf.h" | |
20 | ||
21 | /* | |
22 | * Segment check result | |
23 | */ | |
24 | enum { | |
25 | NILFS_SEG_VALID, | |
26 | NILFS_SEG_NO_SUPER_ROOT, | |
27 | NILFS_SEG_FAIL_IO, | |
28 | NILFS_SEG_FAIL_MAGIC, | |
29 | NILFS_SEG_FAIL_SEQ, | |
30 | NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT, | |
31 | NILFS_SEG_FAIL_CHECKSUM_FULL, | |
32 | NILFS_SEG_FAIL_CONSISTENCY, | |
33 | }; | |
34 | ||
35 | /* work structure for recovery */ | |
36 | struct nilfs_recovery_block { | |
37 | ino_t ino; /* | |
38 | * Inode number of the file that this block | |
39 | * belongs to | |
40 | */ | |
41 | sector_t blocknr; /* block number */ | |
42 | __u64 vblocknr; /* virtual block number */ | |
43 | unsigned long blkoff; /* File offset of the data block (per block) */ | |
44 | struct list_head list; | |
45 | }; | |
46 | ||
47 | ||
48 | static int nilfs_warn_segment_error(struct super_block *sb, int err) | |
49 | { | |
50 | const char *msg = NULL; | |
51 | ||
52 | switch (err) { | |
53 | case NILFS_SEG_FAIL_IO: | |
54 | nilfs_err(sb, "I/O error reading segment"); | |
55 | return -EIO; | |
56 | case NILFS_SEG_FAIL_MAGIC: | |
57 | msg = "Magic number mismatch"; | |
58 | break; | |
59 | case NILFS_SEG_FAIL_SEQ: | |
60 | msg = "Sequence number mismatch"; | |
61 | break; | |
62 | case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT: | |
63 | msg = "Checksum error in super root"; | |
64 | break; | |
65 | case NILFS_SEG_FAIL_CHECKSUM_FULL: | |
66 | msg = "Checksum error in segment payload"; | |
67 | break; | |
68 | case NILFS_SEG_FAIL_CONSISTENCY: | |
69 | msg = "Inconsistency found"; | |
70 | break; | |
71 | case NILFS_SEG_NO_SUPER_ROOT: | |
72 | msg = "No super root in the last segment"; | |
73 | break; | |
74 | default: | |
75 | nilfs_err(sb, "unrecognized segment error %d", err); | |
76 | return -EINVAL; | |
77 | } | |
78 | nilfs_warn(sb, "invalid segment: %s", msg); | |
79 | return -EINVAL; | |
80 | } | |
81 | ||
82 | /** | |
83 | * nilfs_compute_checksum - compute checksum of blocks continuously | |
84 | * @nilfs: nilfs object | |
85 | * @bhs: buffer head of start block | |
86 | * @sum: place to store result | |
87 | * @offset: offset bytes in the first block | |
88 | * @check_bytes: number of bytes to be checked | |
89 | * @start: DBN of start block | |
90 | * @nblock: number of blocks to be checked | |
91 | */ | |
92 | static int nilfs_compute_checksum(struct the_nilfs *nilfs, | |
93 | struct buffer_head *bhs, u32 *sum, | |
94 | unsigned long offset, u64 check_bytes, | |
95 | sector_t start, unsigned long nblock) | |
96 | { | |
97 | unsigned int blocksize = nilfs->ns_blocksize; | |
98 | unsigned long size; | |
99 | u32 crc; | |
100 | ||
101 | BUG_ON(offset >= blocksize); | |
102 | check_bytes -= offset; | |
103 | size = min_t(u64, check_bytes, blocksize - offset); | |
104 | crc = crc32_le(nilfs->ns_crc_seed, | |
105 | (unsigned char *)bhs->b_data + offset, size); | |
106 | if (--nblock > 0) { | |
107 | do { | |
108 | struct buffer_head *bh; | |
109 | ||
110 | bh = __bread(nilfs->ns_bdev, ++start, blocksize); | |
111 | if (!bh) | |
112 | return -EIO; | |
113 | check_bytes -= size; | |
114 | size = min_t(u64, check_bytes, blocksize); | |
115 | crc = crc32_le(crc, bh->b_data, size); | |
116 | brelse(bh); | |
117 | } while (--nblock > 0); | |
118 | } | |
119 | *sum = crc; | |
120 | return 0; | |
121 | } | |
122 | ||
123 | /** | |
124 | * nilfs_read_super_root_block - read super root block | |
125 | * @nilfs: nilfs object | |
126 | * @sr_block: disk block number of the super root block | |
127 | * @pbh: address of a buffer_head pointer to return super root buffer | |
128 | * @check: CRC check flag | |
129 | */ | |
130 | int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block, | |
131 | struct buffer_head **pbh, int check) | |
132 | { | |
133 | struct buffer_head *bh_sr; | |
134 | struct nilfs_super_root *sr; | |
135 | u32 crc; | |
136 | int ret; | |
137 | ||
138 | *pbh = NULL; | |
139 | bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize); | |
140 | if (unlikely(!bh_sr)) { | |
141 | ret = NILFS_SEG_FAIL_IO; | |
142 | goto failed; | |
143 | } | |
144 | ||
145 | sr = (struct nilfs_super_root *)bh_sr->b_data; | |
146 | if (check) { | |
147 | unsigned int bytes = le16_to_cpu(sr->sr_bytes); | |
148 | ||
149 | if (bytes == 0 || bytes > nilfs->ns_blocksize) { | |
150 | ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; | |
151 | goto failed_bh; | |
152 | } | |
153 | if (nilfs_compute_checksum( | |
154 | nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes, | |
155 | sr_block, 1)) { | |
156 | ret = NILFS_SEG_FAIL_IO; | |
157 | goto failed_bh; | |
158 | } | |
159 | if (crc != le32_to_cpu(sr->sr_sum)) { | |
160 | ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; | |
161 | goto failed_bh; | |
162 | } | |
163 | } | |
164 | *pbh = bh_sr; | |
165 | return 0; | |
166 | ||
167 | failed_bh: | |
168 | brelse(bh_sr); | |
169 | ||
170 | failed: | |
171 | return nilfs_warn_segment_error(nilfs->ns_sb, ret); | |
172 | } | |
173 | ||
174 | /** | |
175 | * nilfs_read_log_header - read summary header of the specified log | |
176 | * @nilfs: nilfs object | |
177 | * @start_blocknr: start block number of the log | |
178 | * @sum: pointer to return segment summary structure | |
179 | */ | |
180 | static struct buffer_head * | |
181 | nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr, | |
182 | struct nilfs_segment_summary **sum) | |
183 | { | |
184 | struct buffer_head *bh_sum; | |
185 | ||
186 | bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); | |
187 | if (bh_sum) | |
188 | *sum = (struct nilfs_segment_summary *)bh_sum->b_data; | |
189 | return bh_sum; | |
190 | } | |
191 | ||
192 | /** | |
193 | * nilfs_validate_log - verify consistency of log | |
194 | * @nilfs: nilfs object | |
195 | * @seg_seq: sequence number of segment | |
196 | * @bh_sum: buffer head of summary block | |
197 | * @sum: segment summary struct | |
198 | */ | |
199 | static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq, | |
200 | struct buffer_head *bh_sum, | |
201 | struct nilfs_segment_summary *sum) | |
202 | { | |
203 | unsigned long nblock; | |
204 | u32 crc; | |
205 | int ret; | |
206 | ||
207 | ret = NILFS_SEG_FAIL_MAGIC; | |
208 | if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) | |
209 | goto out; | |
210 | ||
211 | ret = NILFS_SEG_FAIL_SEQ; | |
212 | if (le64_to_cpu(sum->ss_seq) != seg_seq) | |
213 | goto out; | |
214 | ||
215 | nblock = le32_to_cpu(sum->ss_nblocks); | |
216 | ret = NILFS_SEG_FAIL_CONSISTENCY; | |
217 | if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment)) | |
218 | /* This limits the number of blocks read in the CRC check */ | |
219 | goto out; | |
220 | ||
221 | ret = NILFS_SEG_FAIL_IO; | |
222 | if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum), | |
223 | ((u64)nblock << nilfs->ns_blocksize_bits), | |
224 | bh_sum->b_blocknr, nblock)) | |
225 | goto out; | |
226 | ||
227 | ret = NILFS_SEG_FAIL_CHECKSUM_FULL; | |
228 | if (crc != le32_to_cpu(sum->ss_datasum)) | |
229 | goto out; | |
230 | ret = 0; | |
231 | out: | |
232 | return ret; | |
233 | } | |
234 | ||
235 | /** | |
236 | * nilfs_read_summary_info - read an item on summary blocks of a log | |
237 | * @nilfs: nilfs object | |
238 | * @pbh: the current buffer head on summary blocks [in, out] | |
239 | * @offset: the current byte offset on summary blocks [in, out] | |
240 | * @bytes: byte size of the item to be read | |
241 | */ | |
242 | static void *nilfs_read_summary_info(struct the_nilfs *nilfs, | |
243 | struct buffer_head **pbh, | |
244 | unsigned int *offset, unsigned int bytes) | |
245 | { | |
246 | void *ptr; | |
247 | sector_t blocknr; | |
248 | ||
249 | BUG_ON((*pbh)->b_size < *offset); | |
250 | if (bytes > (*pbh)->b_size - *offset) { | |
251 | blocknr = (*pbh)->b_blocknr; | |
252 | brelse(*pbh); | |
253 | *pbh = __bread(nilfs->ns_bdev, blocknr + 1, | |
254 | nilfs->ns_blocksize); | |
255 | if (unlikely(!*pbh)) | |
256 | return NULL; | |
257 | *offset = 0; | |
258 | } | |
259 | ptr = (*pbh)->b_data + *offset; | |
260 | *offset += bytes; | |
261 | return ptr; | |
262 | } | |
263 | ||
264 | /** | |
265 | * nilfs_skip_summary_info - skip items on summary blocks of a log | |
266 | * @nilfs: nilfs object | |
267 | * @pbh: the current buffer head on summary blocks [in, out] | |
268 | * @offset: the current byte offset on summary blocks [in, out] | |
269 | * @bytes: byte size of the item to be skipped | |
270 | * @count: number of items to be skipped | |
271 | */ | |
272 | static void nilfs_skip_summary_info(struct the_nilfs *nilfs, | |
273 | struct buffer_head **pbh, | |
274 | unsigned int *offset, unsigned int bytes, | |
275 | unsigned long count) | |
276 | { | |
277 | unsigned int rest_item_in_current_block | |
278 | = ((*pbh)->b_size - *offset) / bytes; | |
279 | ||
280 | if (count <= rest_item_in_current_block) { | |
281 | *offset += bytes * count; | |
282 | } else { | |
283 | sector_t blocknr = (*pbh)->b_blocknr; | |
284 | unsigned int nitem_per_block = (*pbh)->b_size / bytes; | |
285 | unsigned int bcnt; | |
286 | ||
287 | count -= rest_item_in_current_block; | |
288 | bcnt = DIV_ROUND_UP(count, nitem_per_block); | |
289 | *offset = bytes * (count - (bcnt - 1) * nitem_per_block); | |
290 | ||
291 | brelse(*pbh); | |
292 | *pbh = __bread(nilfs->ns_bdev, blocknr + bcnt, | |
293 | nilfs->ns_blocksize); | |
294 | } | |
295 | } | |
296 | ||
297 | /** | |
298 | * nilfs_scan_dsync_log - get block information of a log written for data sync | |
299 | * @nilfs: nilfs object | |
300 | * @start_blocknr: start block number of the log | |
301 | * @sum: log summary information | |
302 | * @head: list head to add nilfs_recovery_block struct | |
303 | */ | |
304 | static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr, | |
305 | struct nilfs_segment_summary *sum, | |
306 | struct list_head *head) | |
307 | { | |
308 | struct buffer_head *bh; | |
309 | unsigned int offset; | |
310 | u32 nfinfo, sumbytes; | |
311 | sector_t blocknr; | |
312 | ino_t ino; | |
313 | int err = -EIO; | |
314 | ||
315 | nfinfo = le32_to_cpu(sum->ss_nfinfo); | |
316 | if (!nfinfo) | |
317 | return 0; | |
318 | ||
319 | sumbytes = le32_to_cpu(sum->ss_sumbytes); | |
320 | blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize); | |
321 | bh = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); | |
322 | if (unlikely(!bh)) | |
323 | goto out; | |
324 | ||
325 | offset = le16_to_cpu(sum->ss_bytes); | |
326 | for (;;) { | |
327 | unsigned long nblocks, ndatablk, nnodeblk; | |
328 | struct nilfs_finfo *finfo; | |
329 | ||
330 | finfo = nilfs_read_summary_info(nilfs, &bh, &offset, | |
331 | sizeof(*finfo)); | |
332 | if (unlikely(!finfo)) | |
333 | goto out; | |
334 | ||
335 | ino = le64_to_cpu(finfo->fi_ino); | |
336 | nblocks = le32_to_cpu(finfo->fi_nblocks); | |
337 | ndatablk = le32_to_cpu(finfo->fi_ndatablk); | |
338 | nnodeblk = nblocks - ndatablk; | |
339 | ||
340 | while (ndatablk-- > 0) { | |
341 | struct nilfs_recovery_block *rb; | |
342 | struct nilfs_binfo_v *binfo; | |
343 | ||
344 | binfo = nilfs_read_summary_info(nilfs, &bh, &offset, | |
345 | sizeof(*binfo)); | |
346 | if (unlikely(!binfo)) | |
347 | goto out; | |
348 | ||
349 | rb = kmalloc(sizeof(*rb), GFP_NOFS); | |
350 | if (unlikely(!rb)) { | |
351 | err = -ENOMEM; | |
352 | goto out; | |
353 | } | |
354 | rb->ino = ino; | |
355 | rb->blocknr = blocknr++; | |
356 | rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr); | |
357 | rb->blkoff = le64_to_cpu(binfo->bi_blkoff); | |
358 | /* INIT_LIST_HEAD(&rb->list); */ | |
359 | list_add_tail(&rb->list, head); | |
360 | } | |
361 | if (--nfinfo == 0) | |
362 | break; | |
363 | blocknr += nnodeblk; /* always 0 for data sync logs */ | |
364 | nilfs_skip_summary_info(nilfs, &bh, &offset, sizeof(__le64), | |
365 | nnodeblk); | |
366 | if (unlikely(!bh)) | |
367 | goto out; | |
368 | } | |
369 | err = 0; | |
370 | out: | |
371 | brelse(bh); /* brelse(NULL) is just ignored */ | |
372 | return err; | |
373 | } | |
374 | ||
375 | static void dispose_recovery_list(struct list_head *head) | |
376 | { | |
377 | while (!list_empty(head)) { | |
378 | struct nilfs_recovery_block *rb; | |
379 | ||
380 | rb = list_first_entry(head, struct nilfs_recovery_block, list); | |
381 | list_del(&rb->list); | |
382 | kfree(rb); | |
383 | } | |
384 | } | |
385 | ||
386 | struct nilfs_segment_entry { | |
387 | struct list_head list; | |
388 | __u64 segnum; | |
389 | }; | |
390 | ||
391 | static int nilfs_segment_list_add(struct list_head *head, __u64 segnum) | |
392 | { | |
393 | struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS); | |
394 | ||
395 | if (unlikely(!ent)) | |
396 | return -ENOMEM; | |
397 | ||
398 | ent->segnum = segnum; | |
399 | INIT_LIST_HEAD(&ent->list); | |
400 | list_add_tail(&ent->list, head); | |
401 | return 0; | |
402 | } | |
403 | ||
404 | void nilfs_dispose_segment_list(struct list_head *head) | |
405 | { | |
406 | while (!list_empty(head)) { | |
407 | struct nilfs_segment_entry *ent; | |
408 | ||
409 | ent = list_first_entry(head, struct nilfs_segment_entry, list); | |
410 | list_del(&ent->list); | |
411 | kfree(ent); | |
412 | } | |
413 | } | |
414 | ||
415 | static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs, | |
416 | struct super_block *sb, | |
417 | struct nilfs_recovery_info *ri) | |
418 | { | |
419 | struct list_head *head = &ri->ri_used_segments; | |
420 | struct nilfs_segment_entry *ent, *n; | |
421 | struct inode *sufile = nilfs->ns_sufile; | |
422 | __u64 segnum[4]; | |
423 | int err; | |
424 | int i; | |
425 | ||
426 | segnum[0] = nilfs->ns_segnum; | |
427 | segnum[1] = nilfs->ns_nextnum; | |
428 | segnum[2] = ri->ri_segnum; | |
429 | segnum[3] = ri->ri_nextnum; | |
430 | ||
431 | /* | |
432 | * Releasing the next segment of the latest super root. | |
433 | * The next segment is invalidated by this recovery. | |
434 | */ | |
435 | err = nilfs_sufile_free(sufile, segnum[1]); | |
436 | if (unlikely(err)) | |
437 | goto failed; | |
438 | ||
439 | for (i = 1; i < 4; i++) { | |
440 | err = nilfs_segment_list_add(head, segnum[i]); | |
441 | if (unlikely(err)) | |
442 | goto failed; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Collecting segments written after the latest super root. | |
447 | * These are marked dirty to avoid being reallocated in the next write. | |
448 | */ | |
449 | list_for_each_entry_safe(ent, n, head, list) { | |
450 | if (ent->segnum != segnum[0]) { | |
451 | err = nilfs_sufile_scrap(sufile, ent->segnum); | |
452 | if (unlikely(err)) | |
453 | goto failed; | |
454 | } | |
455 | list_del(&ent->list); | |
456 | kfree(ent); | |
457 | } | |
458 | ||
459 | /* Allocate new segments for recovery */ | |
460 | err = nilfs_sufile_alloc(sufile, &segnum[0]); | |
461 | if (unlikely(err)) | |
462 | goto failed; | |
463 | ||
464 | nilfs->ns_pseg_offset = 0; | |
465 | nilfs->ns_seg_seq = ri->ri_seq + 2; | |
466 | nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0]; | |
467 | ||
468 | failed: | |
469 | /* No need to recover sufile because it will be destroyed on error */ | |
470 | return err; | |
471 | } | |
472 | ||
473 | static int nilfs_recovery_copy_block(struct the_nilfs *nilfs, | |
474 | struct nilfs_recovery_block *rb, | |
475 | struct page *page) | |
476 | { | |
477 | struct buffer_head *bh_org; | |
478 | void *kaddr; | |
479 | ||
480 | bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize); | |
481 | if (unlikely(!bh_org)) | |
482 | return -EIO; | |
483 | ||
484 | kaddr = kmap_atomic(page); | |
485 | memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size); | |
486 | kunmap_atomic(kaddr); | |
487 | brelse(bh_org); | |
488 | return 0; | |
489 | } | |
490 | ||
491 | static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs, | |
492 | struct super_block *sb, | |
493 | struct nilfs_root *root, | |
494 | struct list_head *head, | |
495 | unsigned long *nr_salvaged_blocks) | |
496 | { | |
497 | struct inode *inode; | |
498 | struct nilfs_recovery_block *rb, *n; | |
499 | unsigned int blocksize = nilfs->ns_blocksize; | |
500 | struct page *page; | |
501 | loff_t pos; | |
502 | int err = 0, err2 = 0; | |
503 | ||
504 | list_for_each_entry_safe(rb, n, head, list) { | |
505 | inode = nilfs_iget(sb, root, rb->ino); | |
506 | if (IS_ERR(inode)) { | |
507 | err = PTR_ERR(inode); | |
508 | inode = NULL; | |
509 | goto failed_inode; | |
510 | } | |
511 | ||
512 | pos = rb->blkoff << inode->i_blkbits; | |
513 | err = block_write_begin(inode->i_mapping, pos, blocksize, | |
514 | 0, &page, nilfs_get_block); | |
515 | if (unlikely(err)) { | |
516 | loff_t isize = inode->i_size; | |
517 | ||
518 | if (pos + blocksize > isize) | |
519 | nilfs_write_failed(inode->i_mapping, | |
520 | pos + blocksize); | |
521 | goto failed_inode; | |
522 | } | |
523 | ||
524 | err = nilfs_recovery_copy_block(nilfs, rb, page); | |
525 | if (unlikely(err)) | |
526 | goto failed_page; | |
527 | ||
528 | err = nilfs_set_file_dirty(inode, 1); | |
529 | if (unlikely(err)) | |
530 | goto failed_page; | |
531 | ||
532 | block_write_end(NULL, inode->i_mapping, pos, blocksize, | |
533 | blocksize, page, NULL); | |
534 | ||
535 | unlock_page(page); | |
536 | put_page(page); | |
537 | ||
538 | (*nr_salvaged_blocks)++; | |
539 | goto next; | |
540 | ||
541 | failed_page: | |
542 | unlock_page(page); | |
543 | put_page(page); | |
544 | ||
545 | failed_inode: | |
546 | nilfs_warn(sb, | |
547 | "error %d recovering data block (ino=%lu, block-offset=%llu)", | |
548 | err, (unsigned long)rb->ino, | |
549 | (unsigned long long)rb->blkoff); | |
550 | if (!err2) | |
551 | err2 = err; | |
552 | next: | |
553 | iput(inode); /* iput(NULL) is just ignored */ | |
554 | list_del_init(&rb->list); | |
555 | kfree(rb); | |
556 | } | |
557 | return err2; | |
558 | } | |
559 | ||
560 | /** | |
561 | * nilfs_do_roll_forward - salvage logical segments newer than the latest | |
562 | * checkpoint | |
563 | * @nilfs: nilfs object | |
564 | * @sb: super block instance | |
565 | * @ri: pointer to a nilfs_recovery_info | |
566 | */ | |
567 | static int nilfs_do_roll_forward(struct the_nilfs *nilfs, | |
568 | struct super_block *sb, | |
569 | struct nilfs_root *root, | |
570 | struct nilfs_recovery_info *ri) | |
571 | { | |
572 | struct buffer_head *bh_sum = NULL; | |
573 | struct nilfs_segment_summary *sum = NULL; | |
574 | sector_t pseg_start; | |
575 | sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */ | |
576 | unsigned long nsalvaged_blocks = 0; | |
577 | unsigned int flags; | |
578 | u64 seg_seq; | |
579 | __u64 segnum, nextnum = 0; | |
580 | int empty_seg = 0; | |
581 | int err = 0, ret; | |
582 | LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */ | |
583 | enum { | |
584 | RF_INIT_ST, | |
585 | RF_DSYNC_ST, /* scanning data-sync segments */ | |
586 | }; | |
587 | int state = RF_INIT_ST; | |
588 | ||
589 | pseg_start = ri->ri_lsegs_start; | |
590 | seg_seq = ri->ri_lsegs_start_seq; | |
591 | segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); | |
592 | nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); | |
593 | ||
594 | while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) { | |
595 | brelse(bh_sum); | |
596 | bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); | |
597 | if (!bh_sum) { | |
598 | err = -EIO; | |
599 | goto failed; | |
600 | } | |
601 | ||
602 | ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); | |
603 | if (ret) { | |
604 | if (ret == NILFS_SEG_FAIL_IO) { | |
605 | err = -EIO; | |
606 | goto failed; | |
607 | } | |
608 | goto strayed; | |
609 | } | |
610 | ||
611 | flags = le16_to_cpu(sum->ss_flags); | |
612 | if (flags & NILFS_SS_SR) | |
613 | goto confused; | |
614 | ||
615 | /* Found a valid partial segment; do recovery actions */ | |
616 | nextnum = nilfs_get_segnum_of_block(nilfs, | |
617 | le64_to_cpu(sum->ss_next)); | |
618 | empty_seg = 0; | |
619 | nilfs->ns_ctime = le64_to_cpu(sum->ss_create); | |
620 | if (!(flags & NILFS_SS_GC)) | |
621 | nilfs->ns_nongc_ctime = nilfs->ns_ctime; | |
622 | ||
623 | switch (state) { | |
624 | case RF_INIT_ST: | |
625 | if (!(flags & NILFS_SS_LOGBGN) || | |
626 | !(flags & NILFS_SS_SYNDT)) | |
627 | goto try_next_pseg; | |
628 | state = RF_DSYNC_ST; | |
629 | /* Fall through */ | |
630 | case RF_DSYNC_ST: | |
631 | if (!(flags & NILFS_SS_SYNDT)) | |
632 | goto confused; | |
633 | ||
634 | err = nilfs_scan_dsync_log(nilfs, pseg_start, sum, | |
635 | &dsync_blocks); | |
636 | if (unlikely(err)) | |
637 | goto failed; | |
638 | if (flags & NILFS_SS_LOGEND) { | |
639 | err = nilfs_recover_dsync_blocks( | |
640 | nilfs, sb, root, &dsync_blocks, | |
641 | &nsalvaged_blocks); | |
642 | if (unlikely(err)) | |
643 | goto failed; | |
644 | state = RF_INIT_ST; | |
645 | } | |
646 | break; /* Fall through to try_next_pseg */ | |
647 | } | |
648 | ||
649 | try_next_pseg: | |
650 | if (pseg_start == ri->ri_lsegs_end) | |
651 | break; | |
652 | pseg_start += le32_to_cpu(sum->ss_nblocks); | |
653 | if (pseg_start < seg_end) | |
654 | continue; | |
655 | goto feed_segment; | |
656 | ||
657 | strayed: | |
658 | if (pseg_start == ri->ri_lsegs_end) | |
659 | break; | |
660 | ||
661 | feed_segment: | |
662 | /* Looking to the next full segment */ | |
663 | if (empty_seg++) | |
664 | break; | |
665 | seg_seq++; | |
666 | segnum = nextnum; | |
667 | nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); | |
668 | pseg_start = seg_start; | |
669 | } | |
670 | ||
671 | if (nsalvaged_blocks) { | |
672 | nilfs_info(sb, "salvaged %lu blocks", nsalvaged_blocks); | |
673 | ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE; | |
674 | } | |
675 | out: | |
676 | brelse(bh_sum); | |
677 | dispose_recovery_list(&dsync_blocks); | |
678 | return err; | |
679 | ||
680 | confused: | |
681 | err = -EINVAL; | |
682 | failed: | |
683 | nilfs_err(sb, | |
684 | "error %d roll-forwarding partial segment at blocknr = %llu", | |
685 | err, (unsigned long long)pseg_start); | |
686 | goto out; | |
687 | } | |
688 | ||
689 | static void nilfs_finish_roll_forward(struct the_nilfs *nilfs, | |
690 | struct nilfs_recovery_info *ri) | |
691 | { | |
692 | struct buffer_head *bh; | |
693 | int err; | |
694 | ||
695 | if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) != | |
696 | nilfs_get_segnum_of_block(nilfs, ri->ri_super_root)) | |
697 | return; | |
698 | ||
699 | bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize); | |
700 | BUG_ON(!bh); | |
701 | memset(bh->b_data, 0, bh->b_size); | |
702 | set_buffer_dirty(bh); | |
703 | err = sync_dirty_buffer(bh); | |
704 | if (unlikely(err)) | |
705 | nilfs_warn(nilfs->ns_sb, | |
706 | "buffer sync write failed during post-cleaning of recovery."); | |
707 | brelse(bh); | |
708 | } | |
709 | ||
710 | /** | |
711 | * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint | |
712 | * @nilfs: nilfs object | |
713 | * @sb: super block instance | |
714 | * @ri: pointer to a nilfs_recovery_info struct to store search results. | |
715 | * | |
716 | * Return Value: On success, 0 is returned. On error, one of the following | |
717 | * negative error code is returned. | |
718 | * | |
719 | * %-EINVAL - Inconsistent filesystem state. | |
720 | * | |
721 | * %-EIO - I/O error | |
722 | * | |
723 | * %-ENOSPC - No space left on device (only in a panic state). | |
724 | * | |
725 | * %-ERESTARTSYS - Interrupted. | |
726 | * | |
727 | * %-ENOMEM - Insufficient memory available. | |
728 | */ | |
729 | int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, | |
730 | struct super_block *sb, | |
731 | struct nilfs_recovery_info *ri) | |
732 | { | |
733 | struct nilfs_root *root; | |
734 | int err; | |
735 | ||
736 | if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0) | |
737 | return 0; | |
738 | ||
739 | err = nilfs_attach_checkpoint(sb, ri->ri_cno, true, &root); | |
740 | if (unlikely(err)) { | |
741 | nilfs_err(sb, "error %d loading the latest checkpoint", err); | |
742 | return err; | |
743 | } | |
744 | ||
745 | err = nilfs_do_roll_forward(nilfs, sb, root, ri); | |
746 | if (unlikely(err)) | |
747 | goto failed; | |
748 | ||
749 | if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) { | |
750 | err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri); | |
751 | if (unlikely(err)) { | |
752 | nilfs_err(sb, "error %d preparing segment for recovery", | |
753 | err); | |
754 | goto failed; | |
755 | } | |
756 | ||
757 | err = nilfs_attach_log_writer(sb, root); | |
758 | if (unlikely(err)) | |
759 | goto failed; | |
760 | ||
761 | set_nilfs_discontinued(nilfs); | |
762 | err = nilfs_construct_segment(sb); | |
763 | nilfs_detach_log_writer(sb); | |
764 | ||
765 | if (unlikely(err)) { | |
766 | nilfs_err(sb, "error %d writing segment for recovery", | |
767 | err); | |
768 | goto failed; | |
769 | } | |
770 | ||
771 | nilfs_finish_roll_forward(nilfs, ri); | |
772 | } | |
773 | ||
774 | failed: | |
775 | nilfs_put_root(root); | |
776 | return err; | |
777 | } | |
778 | ||
779 | /** | |
780 | * nilfs_search_super_root - search the latest valid super root | |
781 | * @nilfs: the_nilfs | |
782 | * @ri: pointer to a nilfs_recovery_info struct to store search results. | |
783 | * | |
784 | * nilfs_search_super_root() looks for the latest super-root from a partial | |
785 | * segment pointed by the superblock. It sets up struct the_nilfs through | |
786 | * this search. It fills nilfs_recovery_info (ri) required for recovery. | |
787 | * | |
788 | * Return Value: On success, 0 is returned. On error, one of the following | |
789 | * negative error code is returned. | |
790 | * | |
791 | * %-EINVAL - No valid segment found | |
792 | * | |
793 | * %-EIO - I/O error | |
794 | * | |
795 | * %-ENOMEM - Insufficient memory available. | |
796 | */ | |
797 | int nilfs_search_super_root(struct the_nilfs *nilfs, | |
798 | struct nilfs_recovery_info *ri) | |
799 | { | |
800 | struct buffer_head *bh_sum = NULL; | |
801 | struct nilfs_segment_summary *sum = NULL; | |
802 | sector_t pseg_start, pseg_end, sr_pseg_start = 0; | |
803 | sector_t seg_start, seg_end; /* range of full segment (block number) */ | |
804 | sector_t b, end; | |
805 | unsigned long nblocks; | |
806 | unsigned int flags; | |
807 | u64 seg_seq; | |
808 | __u64 segnum, nextnum = 0; | |
809 | __u64 cno; | |
810 | LIST_HEAD(segments); | |
811 | int empty_seg = 0, scan_newer = 0; | |
812 | int ret; | |
813 | ||
814 | pseg_start = nilfs->ns_last_pseg; | |
815 | seg_seq = nilfs->ns_last_seq; | |
816 | cno = nilfs->ns_last_cno; | |
817 | segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); | |
818 | ||
819 | /* Calculate range of segment */ | |
820 | nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); | |
821 | ||
822 | /* Read ahead segment */ | |
823 | b = seg_start; | |
824 | while (b <= seg_end) | |
825 | __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize); | |
826 | ||
827 | for (;;) { | |
828 | brelse(bh_sum); | |
829 | ret = NILFS_SEG_FAIL_IO; | |
830 | bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); | |
831 | if (!bh_sum) | |
832 | goto failed; | |
833 | ||
834 | ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); | |
835 | if (ret) { | |
836 | if (ret == NILFS_SEG_FAIL_IO) | |
837 | goto failed; | |
838 | goto strayed; | |
839 | } | |
840 | ||
841 | nblocks = le32_to_cpu(sum->ss_nblocks); | |
842 | pseg_end = pseg_start + nblocks - 1; | |
843 | if (unlikely(pseg_end > seg_end)) { | |
844 | ret = NILFS_SEG_FAIL_CONSISTENCY; | |
845 | goto strayed; | |
846 | } | |
847 | ||
848 | /* A valid partial segment */ | |
849 | ri->ri_pseg_start = pseg_start; | |
850 | ri->ri_seq = seg_seq; | |
851 | ri->ri_segnum = segnum; | |
852 | nextnum = nilfs_get_segnum_of_block(nilfs, | |
853 | le64_to_cpu(sum->ss_next)); | |
854 | ri->ri_nextnum = nextnum; | |
855 | empty_seg = 0; | |
856 | ||
857 | flags = le16_to_cpu(sum->ss_flags); | |
858 | if (!(flags & NILFS_SS_SR) && !scan_newer) { | |
859 | /* | |
860 | * This will never happen because a superblock | |
861 | * (last_segment) always points to a pseg with | |
862 | * a super root. | |
863 | */ | |
864 | ret = NILFS_SEG_FAIL_CONSISTENCY; | |
865 | goto failed; | |
866 | } | |
867 | ||
868 | if (pseg_start == seg_start) { | |
869 | nilfs_get_segment_range(nilfs, nextnum, &b, &end); | |
870 | while (b <= end) | |
871 | __breadahead(nilfs->ns_bdev, b++, | |
872 | nilfs->ns_blocksize); | |
873 | } | |
874 | if (!(flags & NILFS_SS_SR)) { | |
875 | if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) { | |
876 | ri->ri_lsegs_start = pseg_start; | |
877 | ri->ri_lsegs_start_seq = seg_seq; | |
878 | } | |
879 | if (flags & NILFS_SS_LOGEND) | |
880 | ri->ri_lsegs_end = pseg_start; | |
881 | goto try_next_pseg; | |
882 | } | |
883 | ||
884 | /* A valid super root was found. */ | |
885 | ri->ri_cno = cno++; | |
886 | ri->ri_super_root = pseg_end; | |
887 | ri->ri_lsegs_start = ri->ri_lsegs_end = 0; | |
888 | ||
889 | nilfs_dispose_segment_list(&segments); | |
890 | sr_pseg_start = pseg_start; | |
891 | nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start; | |
892 | nilfs->ns_seg_seq = seg_seq; | |
893 | nilfs->ns_segnum = segnum; | |
894 | nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */ | |
895 | nilfs->ns_ctime = le64_to_cpu(sum->ss_create); | |
896 | nilfs->ns_nextnum = nextnum; | |
897 | ||
898 | if (scan_newer) | |
899 | ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED; | |
900 | else { | |
901 | if (nilfs->ns_mount_state & NILFS_VALID_FS) | |
902 | goto super_root_found; | |
903 | scan_newer = 1; | |
904 | } | |
905 | ||
906 | try_next_pseg: | |
907 | /* Standing on a course, or met an inconsistent state */ | |
908 | pseg_start += nblocks; | |
909 | if (pseg_start < seg_end) | |
910 | continue; | |
911 | goto feed_segment; | |
912 | ||
913 | strayed: | |
914 | /* Off the trail */ | |
915 | if (!scan_newer) | |
916 | /* | |
917 | * This can happen if a checkpoint was written without | |
918 | * barriers, or as a result of an I/O failure. | |
919 | */ | |
920 | goto failed; | |
921 | ||
922 | feed_segment: | |
923 | /* Looking to the next full segment */ | |
924 | if (empty_seg++) | |
925 | goto super_root_found; /* found a valid super root */ | |
926 | ||
927 | ret = nilfs_segment_list_add(&segments, segnum); | |
928 | if (unlikely(ret)) | |
929 | goto failed; | |
930 | ||
931 | seg_seq++; | |
932 | segnum = nextnum; | |
933 | nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); | |
934 | pseg_start = seg_start; | |
935 | } | |
936 | ||
937 | super_root_found: | |
938 | /* Updating pointers relating to the latest checkpoint */ | |
939 | brelse(bh_sum); | |
940 | list_splice_tail(&segments, &ri->ri_used_segments); | |
941 | nilfs->ns_last_pseg = sr_pseg_start; | |
942 | nilfs->ns_last_seq = nilfs->ns_seg_seq; | |
943 | nilfs->ns_last_cno = ri->ri_cno; | |
944 | return 0; | |
945 | ||
946 | failed: | |
947 | brelse(bh_sum); | |
948 | nilfs_dispose_segment_list(&segments); | |
949 | return ret < 0 ? ret : nilfs_warn_segment_error(nilfs->ns_sb, ret); | |
950 | } |