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nilfs2: recovery functions
[linux-2.6-block.git] / fs / nilfs2 / recovery.c
CommitLineData
0f3e1c7f
RK		 1/*
2 * recovery.c - NILFS recovery logic
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 */
22
23#include <linux/buffer_head.h>
24#include <linux/blkdev.h>
25#include <linux/swap.h>
26#include <linux/crc32.h>
27#include "nilfs.h"
28#include "segment.h"
29#include "sufile.h"
30#include "page.h"
31#include "seglist.h"
32#include "segbuf.h"
33
34/*
35 * Segment check result
36 */
37enum {
38 NILFS_SEG_VALID,
39 NILFS_SEG_NO_SUPER_ROOT,
40 NILFS_SEG_FAIL_IO,
41 NILFS_SEG_FAIL_MAGIC,
42 NILFS_SEG_FAIL_SEQ,
43 NILFS_SEG_FAIL_CHECKSUM_SEGSUM,
44 NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT,
45 NILFS_SEG_FAIL_CHECKSUM_FULL,
46 NILFS_SEG_FAIL_CONSISTENCY,
47};
48
49/* work structure for recovery */
50struct nilfs_recovery_block {
51 ino_t ino; /* Inode number of the file that this block
52 belongs to */
53 sector_t blocknr; /* block number */
54 __u64 vblocknr; /* virtual block number */
55 unsigned long blkoff; /* File offset of the data block (per block) */
56 struct list_head list;
57};
58
59
60static int nilfs_warn_segment_error(int err)
61{
62 switch (err) {
63 case NILFS_SEG_FAIL_IO:
64 printk(KERN_WARNING
65 "NILFS warning: I/O error on loading last segment\n");
66 return -EIO;
67 case NILFS_SEG_FAIL_MAGIC:
68 printk(KERN_WARNING
69 "NILFS warning: Segment magic number invalid\n");
70 break;
71 case NILFS_SEG_FAIL_SEQ:
72 printk(KERN_WARNING
73 "NILFS warning: Sequence number mismatch\n");
74 break;
75 case NILFS_SEG_FAIL_CHECKSUM_SEGSUM:
76 printk(KERN_WARNING
77 "NILFS warning: Checksum error in segment summary\n");
78 break;
79 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT:
80 printk(KERN_WARNING
81 "NILFS warning: Checksum error in super root\n");
82 break;
83 case NILFS_SEG_FAIL_CHECKSUM_FULL:
84 printk(KERN_WARNING
85 "NILFS warning: Checksum error in segment payload\n");
86 break;
87 case NILFS_SEG_FAIL_CONSISTENCY:
88 printk(KERN_WARNING
89 "NILFS warning: Inconsistent segment\n");
90 break;
91 case NILFS_SEG_NO_SUPER_ROOT:
92 printk(KERN_WARNING
93 "NILFS warning: No super root in the last segment\n");
94 break;
95 case NILFS_SEG_VALID:
96 default:
97 BUG();
98 }
99 return -EINVAL;
100}
101
102static void store_segsum_info(struct nilfs_segsum_info *ssi,
103 struct nilfs_segment_summary *sum,
104 unsigned int blocksize)
105{
106 ssi->flags = le16_to_cpu(sum->ss_flags);
107 ssi->seg_seq = le64_to_cpu(sum->ss_seq);
108 ssi->ctime = le64_to_cpu(sum->ss_create);
109 ssi->next = le64_to_cpu(sum->ss_next);
110 ssi->nblocks = le32_to_cpu(sum->ss_nblocks);
111 ssi->nfinfo = le32_to_cpu(sum->ss_nfinfo);
112 ssi->sumbytes = le32_to_cpu(sum->ss_sumbytes);
113
114 ssi->nsumblk = DIV_ROUND_UP(ssi->sumbytes, blocksize);
115 ssi->nfileblk = ssi->nblocks - ssi->nsumblk - !!NILFS_SEG_HAS_SR(ssi);
116}
117
118/**
119 * calc_crc_cont - check CRC of blocks continuously
120 * @sbi: nilfs_sb_info
121 * @bhs: buffer head of start block
122 * @sum: place to store result
123 * @offset: offset bytes in the first block
124 * @check_bytes: number of bytes to be checked
125 * @start: DBN of start block
126 * @nblock: number of blocks to be checked
127 */
128static int calc_crc_cont(struct nilfs_sb_info *sbi, struct buffer_head *bhs,
129 u32 *sum, unsigned long offset, u64 check_bytes,
130 sector_t start, unsigned long nblock)
131{
132 unsigned long blocksize = sbi->s_super->s_blocksize;
133 unsigned long size;
134 u32 crc;
135
136 BUG_ON(offset >= blocksize);
137 check_bytes -= offset;
138 size = min_t(u64, check_bytes, blocksize - offset);
139 crc = crc32_le(sbi->s_nilfs->ns_crc_seed,
140 (unsigned char *)bhs->b_data + offset, size);
141 if (--nblock > 0) {
142 do {
143 struct buffer_head *bh
144 = sb_bread(sbi->s_super, ++start);
145 if (!bh)
146 return -EIO;
147 check_bytes -= size;
148 size = min_t(u64, check_bytes, blocksize);
149 crc = crc32_le(crc, bh->b_data, size);
150 brelse(bh);
151 } while (--nblock > 0);
152 }
153 *sum = crc;
154 return 0;
155}
156
157/**
158 * nilfs_read_super_root_block - read super root block
159 * @sb: super_block
160 * @sr_block: disk block number of the super root block
161 * @pbh: address of a buffer_head pointer to return super root buffer
162 * @check: CRC check flag
163 */
164int nilfs_read_super_root_block(struct super_block *sb, sector_t sr_block,
165 struct buffer_head **pbh, int check)
166{
167 struct buffer_head *bh_sr;
168 struct nilfs_super_root *sr;
169 u32 crc;
170 int ret;
171
172 *pbh = NULL;
173 bh_sr = sb_bread(sb, sr_block);
174 if (unlikely(!bh_sr)) {
175 ret = NILFS_SEG_FAIL_IO;
176 goto failed;
177 }
178
179 sr = (struct nilfs_super_root *)bh_sr->b_data;
180 if (check) {
181 unsigned bytes = le16_to_cpu(sr->sr_bytes);
182
183 if (bytes == 0 || bytes > sb->s_blocksize) {
184 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
185 goto failed_bh;
186 }
187 if (calc_crc_cont(NILFS_SB(sb), bh_sr, &crc,
188 sizeof(sr->sr_sum), bytes, sr_block, 1)) {
189 ret = NILFS_SEG_FAIL_IO;
190 goto failed_bh;
191 }
192 if (crc != le32_to_cpu(sr->sr_sum)) {
193 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
194 goto failed_bh;
195 }
196 }
197 *pbh = bh_sr;
198 return 0;
199
200 failed_bh:
201 brelse(bh_sr);
202
203 failed:
204 return nilfs_warn_segment_error(ret);
205}
206
207/**
208 * load_segment_summary - read segment summary of the specified partial segment
209 * @sbi: nilfs_sb_info
210 * @pseg_start: start disk block number of partial segment
211 * @seg_seq: sequence number requested
212 * @ssi: pointer to nilfs_segsum_info struct to store information
213 * @full_check: full check flag
214 * (0: only checks segment summary CRC, 1: data CRC)
215 */
216static int
217load_segment_summary(struct nilfs_sb_info *sbi, sector_t pseg_start,
218 u64 seg_seq, struct nilfs_segsum_info *ssi,
219 int full_check)
220{
221 struct buffer_head *bh_sum;
222 struct nilfs_segment_summary *sum;
223 unsigned long offset, nblock;
224 u64 check_bytes;
225 u32 crc, crc_sum;
226 int ret = NILFS_SEG_FAIL_IO;
227
228 bh_sum = sb_bread(sbi->s_super, pseg_start);
229 if (!bh_sum)
230 goto out;
231
232 sum = (struct nilfs_segment_summary *)bh_sum->b_data;
233
234 /* Check consistency of segment summary */
235 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) {
236 ret = NILFS_SEG_FAIL_MAGIC;
237 goto failed;
238 }
239 store_segsum_info(ssi, sum, sbi->s_super->s_blocksize);
240 if (seg_seq != ssi->seg_seq) {
241 ret = NILFS_SEG_FAIL_SEQ;
242 goto failed;
243 }
244 if (full_check) {
245 offset = sizeof(sum->ss_datasum);
246 check_bytes =
247 ((u64)ssi->nblocks << sbi->s_super->s_blocksize_bits);
248 nblock = ssi->nblocks;
249 crc_sum = le32_to_cpu(sum->ss_datasum);
250 ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
251 } else { /* only checks segment summary */
252 offset = sizeof(sum->ss_datasum) + sizeof(sum->ss_sumsum);
253 check_bytes = ssi->sumbytes;
254 nblock = ssi->nsumblk;
255 crc_sum = le32_to_cpu(sum->ss_sumsum);
256 ret = NILFS_SEG_FAIL_CHECKSUM_SEGSUM;
257 }
258
259 if (unlikely(nblock == 0 ||
260 nblock > sbi->s_nilfs->ns_blocks_per_segment)) {
261 /* This limits the number of blocks read in the CRC check */
262 ret = NILFS_SEG_FAIL_CONSISTENCY;
263 goto failed;
264 }
265 if (calc_crc_cont(sbi, bh_sum, &crc, offset, check_bytes,
266 pseg_start, nblock)) {
267 ret = NILFS_SEG_FAIL_IO;
268 goto failed;
269 }
270 if (crc == crc_sum)
271 ret = 0;
272 failed:
273 brelse(bh_sum);
274 out:
275 return ret;
276}
277
278static void *segsum_get(struct super_block *sb, struct buffer_head **pbh,
279 unsigned int *offset, unsigned int bytes)
280{
281 void *ptr;
282 sector_t blocknr;
283
284 BUG_ON((*pbh)->b_size < *offset);
285 if (bytes > (*pbh)->b_size - *offset) {
286 blocknr = (*pbh)->b_blocknr;
287 brelse(*pbh);
288 *pbh = sb_bread(sb, blocknr + 1);
289 if (unlikely(!*pbh))
290 return NULL;
291 *offset = 0;
292 }
293 ptr = (*pbh)->b_data + *offset;
294 *offset += bytes;
295 return ptr;
296}
297
298static void segsum_skip(struct super_block *sb, struct buffer_head **pbh,
299 unsigned int *offset, unsigned int bytes,
300 unsigned long count)
301{
302 unsigned int rest_item_in_current_block
303 = ((*pbh)->b_size - *offset) / bytes;
304
305 if (count <= rest_item_in_current_block) {
306 *offset += bytes * count;
307 } else {
308 sector_t blocknr = (*pbh)->b_blocknr;
309 unsigned int nitem_per_block = (*pbh)->b_size / bytes;
310 unsigned int bcnt;
311
312 count -= rest_item_in_current_block;
313 bcnt = DIV_ROUND_UP(count, nitem_per_block);
314 *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
315
316 brelse(*pbh);
317 *pbh = sb_bread(sb, blocknr + bcnt);
318 }
319}
320
321static int
322collect_blocks_from_segsum(struct nilfs_sb_info *sbi, sector_t sum_blocknr,
323 struct nilfs_segsum_info *ssi,
324 struct list_head *head)
325{
326 struct buffer_head *bh;
327 unsigned int offset;
328 unsigned long nfinfo = ssi->nfinfo;
329 sector_t blocknr = sum_blocknr + ssi->nsumblk;
330 ino_t ino;
331 int err = -EIO;
332
333 if (!nfinfo)
334 return 0;
335
336 bh = sb_bread(sbi->s_super, sum_blocknr);
337 if (unlikely(!bh))
338 goto out;
339
340 offset = le16_to_cpu(
341 ((struct nilfs_segment_summary *)bh->b_data)->ss_bytes);
342 for (;;) {
343 unsigned long nblocks, ndatablk, nnodeblk;
344 struct nilfs_finfo *finfo;
345
346 finfo = segsum_get(sbi->s_super, &bh, &offset, sizeof(*finfo));
347 if (unlikely(!finfo))
348 goto out;
349
350 ino = le64_to_cpu(finfo->fi_ino);
351 nblocks = le32_to_cpu(finfo->fi_nblocks);
352 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
353 nnodeblk = nblocks - ndatablk;
354
355 while (ndatablk-- > 0) {
356 struct nilfs_recovery_block *rb;
357 struct nilfs_binfo_v *binfo;
358
359 binfo = segsum_get(sbi->s_super, &bh, &offset,
360 sizeof(*binfo));
361 if (unlikely(!binfo))
362 goto out;
363
364 rb = kmalloc(sizeof(*rb), GFP_NOFS);
365 if (unlikely(!rb)) {
366 err = -ENOMEM;
367 goto out;
368 }
369 rb->ino = ino;
370 rb->blocknr = blocknr++;
371 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr);
372 rb->blkoff = le64_to_cpu(binfo->bi_blkoff);
373 /* INIT_LIST_HEAD(&rb->list); */
374 list_add_tail(&rb->list, head);
375 }
376 if (--nfinfo == 0)
377 break;
378 blocknr += nnodeblk; /* always 0 for the data sync segments */
379 segsum_skip(sbi->s_super, &bh, &offset, sizeof(__le64),
380 nnodeblk);
381 if (unlikely(!bh))
382 goto out;
383 }
384 err = 0;
385 out:
386 brelse(bh); /* brelse(NULL) is just ignored */
387 return err;
388}
389
390static void dispose_recovery_list(struct list_head *head)
391{
392 while (!list_empty(head)) {
393 struct nilfs_recovery_block *rb
394 = list_entry(head->next,
395 struct nilfs_recovery_block, list);
396 list_del(&rb->list);
397 kfree(rb);
398 }
399}
400
401void nilfs_dispose_segment_list(struct list_head *head)
402{
403 while (!list_empty(head)) {
404 struct nilfs_segment_entry *ent
405 = list_entry(head->next,
406 struct nilfs_segment_entry, list);
407 list_del(&ent->list);
408 nilfs_free_segment_entry(ent);
409 }
410}
411
412static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
413 struct nilfs_recovery_info *ri)
414{
415 struct list_head *head = &ri->ri_used_segments;
416 struct nilfs_segment_entry *ent, *n;
417 struct inode *sufile = nilfs->ns_sufile;
418 __u64 segnum[4];
419 int err;
420 int i;
421
422 segnum[0] = nilfs->ns_segnum;
423 segnum[1] = nilfs->ns_nextnum;
424 segnum[2] = ri->ri_segnum;
425 segnum[3] = ri->ri_nextnum;
426
427 /*
428 * Releasing the next segment of the latest super root.
429 * The next segment is invalidated by this recovery.
430 */
431 err = nilfs_sufile_free(sufile, segnum[1]);
432 if (unlikely(err))
433 goto failed;
434
435 err = -ENOMEM;
436 for (i = 1; i < 4; i++) {
437 ent = nilfs_alloc_segment_entry(segnum[i]);
438 if (unlikely(!ent))
439 goto failed;
440 list_add_tail(&ent->list, head);
441 }
442
443 /*
444 * Collecting segments written after the latest super root.
445 * These are marked volatile active, and won't be reallocated in
446 * the next construction.
447 */
448 list_for_each_entry_safe(ent, n, head, list) {
449 if (ent->segnum == segnum[0]) {
450 list_del(&ent->list);
451 nilfs_free_segment_entry(ent);
452 continue;
453 }
454 err = nilfs_open_segment_entry(ent, sufile);
455 if (unlikely(err))
456 goto failed;
457 if (nilfs_segment_usage_clean(ent->raw_su)) {
458 nilfs_segment_usage_set_volatile_active(ent->raw_su);
459 /* Keep it open */
460 } else {
461 /* Removing duplicated entries */
462 list_del(&ent->list);
463 nilfs_close_segment_entry(ent, sufile);
464 nilfs_free_segment_entry(ent);
465 }
466 }
467 list_splice_init(head, nilfs->ns_used_segments.prev);
468
469 /*
470 * The segment having the latest super root is active, and
471 * should be deactivated on the next construction for recovery.
472 */
473 err = -ENOMEM;
474 ent = nilfs_alloc_segment_entry(segnum[0]);
475 if (unlikely(!ent))
476 goto failed;
477 list_add_tail(&ent->list, &ri->ri_used_segments);
478
479 /* Allocate new segments for recovery */
480 err = nilfs_sufile_alloc(sufile, &segnum[0]);
481 if (unlikely(err))
482 goto failed;
483
484 nilfs->ns_pseg_offset = 0;
485 nilfs->ns_seg_seq = ri->ri_seq + 2;
486 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
487 return 0;
488
489 failed:
490 /* No need to recover sufile because it will be destroyed on error */
491 return err;
492}
493
494static int nilfs_recovery_copy_block(struct nilfs_sb_info *sbi,
495 struct nilfs_recovery_block *rb,
496 struct page *page)
497{
498 struct buffer_head *bh_org;
499 void *kaddr;
500
501 bh_org = sb_bread(sbi->s_super, rb->blocknr);
502 if (unlikely(!bh_org))
503 return -EIO;
504
505 kaddr = kmap_atomic(page, KM_USER0);
506 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
507 kunmap_atomic(kaddr, KM_USER0);
508 brelse(bh_org);
509 return 0;
510}
511
512static int recover_dsync_blocks(struct nilfs_sb_info *sbi,
513 struct list_head *head,
514 unsigned long *nr_salvaged_blocks)
515{
516 struct inode *inode;
517 struct nilfs_recovery_block *rb, *n;
518 unsigned blocksize = sbi->s_super->s_blocksize;
519 struct page *page;
520 loff_t pos;
521 int err = 0, err2 = 0;
522
523 list_for_each_entry_safe(rb, n, head, list) {
524 inode = nilfs_iget(sbi->s_super, rb->ino);
525 if (IS_ERR(inode)) {
526 err = PTR_ERR(inode);
527 inode = NULL;
528 goto failed_inode;
529 }
530
531 pos = rb->blkoff << inode->i_blkbits;
532 page = NULL;
533 err = block_write_begin(NULL, inode->i_mapping, pos, blocksize,
534 0, &page, NULL, nilfs_get_block);
535 if (unlikely(err))
536 goto failed_inode;
537
538 err = nilfs_recovery_copy_block(sbi, rb, page);
539 if (unlikely(err))
540 goto failed_page;
541
542 err = nilfs_set_file_dirty(sbi, inode, 1);
543 if (unlikely(err))
544 goto failed_page;
545
546 block_write_end(NULL, inode->i_mapping, pos, blocksize,
547 blocksize, page, NULL);
548
549 unlock_page(page);
550 page_cache_release(page);
551
552 (*nr_salvaged_blocks)++;
553 goto next;
554
555 failed_page:
556 unlock_page(page);
557 page_cache_release(page);
558
559 failed_inode:
560 printk(KERN_WARNING
561 "NILFS warning: error recovering data block "
562 "(err=%d, ino=%lu, block-offset=%llu)\n",
563 err, rb->ino, (unsigned long long)rb->blkoff);
564 if (!err2)
565 err2 = err;
566 next:
567 iput(inode); /* iput(NULL) is just ignored */
568 list_del_init(&rb->list);
569 kfree(rb);
570 }
571 return err2;
572}
573
574/**
575 * nilfs_do_roll_forward - salvage logical segments newer than the latest
576 * checkpoint
577 * @sbi: nilfs_sb_info
578 * @nilfs: the_nilfs
579 * @ri: pointer to a nilfs_recovery_info
580 */
581static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
582 struct nilfs_sb_info *sbi,
583 struct nilfs_recovery_info *ri)
584{
585 struct nilfs_segsum_info ssi;
586 sector_t pseg_start;
587 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
588 unsigned long nsalvaged_blocks = 0;
589 u64 seg_seq;
590 __u64 segnum, nextnum = 0;
591 int empty_seg = 0;
592 int err = 0, ret;
593 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
594 enum {
595 RF_INIT_ST,
596 RF_DSYNC_ST, /* scanning data-sync segments */
597 };
598 int state = RF_INIT_ST;
599
600 nilfs_attach_writer(nilfs, sbi);
601 pseg_start = ri->ri_lsegs_start;
602 seg_seq = ri->ri_lsegs_start_seq;
603 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
604 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
605
606 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
607
608 ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
609 if (ret) {
610 if (ret == NILFS_SEG_FAIL_IO) {
611 err = -EIO;
612 goto failed;
613 }
614 goto strayed;
615 }
616 if (unlikely(NILFS_SEG_HAS_SR(&ssi)))
617 goto confused;
618
619 /* Found a valid partial segment; do recovery actions */
620 nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
621 empty_seg = 0;
622 nilfs->ns_ctime = ssi.ctime;
623 if (!(ssi.flags & NILFS_SS_GC))
624 nilfs->ns_nongc_ctime = ssi.ctime;
625
626 switch (state) {
627 case RF_INIT_ST:
628 if (!NILFS_SEG_LOGBGN(&ssi) || !NILFS_SEG_DSYNC(&ssi))
629 goto try_next_pseg;
630 state = RF_DSYNC_ST;
631 /* Fall through */
632 case RF_DSYNC_ST:
633 if (!NILFS_SEG_DSYNC(&ssi))
634 goto confused;
635
636 err = collect_blocks_from_segsum(
637 sbi, pseg_start, &ssi, &dsync_blocks);
638 if (unlikely(err))
639 goto failed;
640 if (NILFS_SEG_LOGEND(&ssi)) {
641 err = recover_dsync_blocks(
642 sbi, &dsync_blocks, &nsalvaged_blocks);
643 if (unlikely(err))
644 goto failed;
645 state = RF_INIT_ST;
646 }
647 break; /* Fall through to try_next_pseg */
648 }
649
650 try_next_pseg:
651 if (pseg_start == ri->ri_lsegs_end)
652 break;
653 pseg_start += ssi.nblocks;
654 if (pseg_start < seg_end)
655 continue;
656 goto feed_segment;
657
658 strayed:
659 if (pseg_start == ri->ri_lsegs_end)
660 break;
661
662 feed_segment:
663 /* Looking to the next full segment */
664 if (empty_seg++)
665 break;
666 seg_seq++;
667 segnum = nextnum;
668 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
669 pseg_start = seg_start;
670 }
671
672 if (nsalvaged_blocks) {
673 printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n",
674 sbi->s_super->s_id, nsalvaged_blocks);
675 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
676 }
677 out:
678 dispose_recovery_list(&dsync_blocks);
679 nilfs_detach_writer(sbi->s_nilfs, sbi);
680 return err;
681
682 confused:
683 err = -EINVAL;
684 failed:
685 printk(KERN_ERR
686 "NILFS (device %s): Error roll-forwarding "
687 "(err=%d, pseg block=%llu). ",
688 sbi->s_super->s_id, err, (unsigned long long)pseg_start);
689 goto out;
690}
691
692static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
693 struct nilfs_sb_info *sbi,
694 struct nilfs_recovery_info *ri)
695{
696 struct buffer_head *bh;
697 int err;
698
699 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) !=
700 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root))
701 return;
702
703 bh = sb_getblk(sbi->s_super, ri->ri_lsegs_start);
704 BUG_ON(!bh);
705 memset(bh->b_data, 0, bh->b_size);
706 set_buffer_dirty(bh);
707 err = sync_dirty_buffer(bh);
708 if (unlikely(err))
709 printk(KERN_WARNING
710 "NILFS warning: buffer sync write failed during "
711 "post-cleaning of recovery.\n");
712 brelse(bh);
713}
714
715/**
716 * nilfs_recover_logical_segments - salvage logical segments written after
717 * the latest super root
718 * @nilfs: the_nilfs
719 * @sbi: nilfs_sb_info
720 * @ri: pointer to a nilfs_recovery_info struct to store search results.
721 *
722 * Return Value: On success, 0 is returned. On error, one of the following
723 * negative error code is returned.
724 *
725 * %-EINVAL - Inconsistent filesystem state.
726 *
727 * %-EIO - I/O error
728 *
729 * %-ENOSPC - No space left on device (only in a panic state).
730 *
731 * %-ERESTARTSYS - Interrupted.
732 *
733 * %-ENOMEM - Insufficient memory available.
734 */
735int nilfs_recover_logical_segments(struct the_nilfs *nilfs,
736 struct nilfs_sb_info *sbi,
737 struct nilfs_recovery_info *ri)
738{
739 int err;
740
741 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
742 return 0;
743
744 err = nilfs_attach_checkpoint(sbi, ri->ri_cno);
745 if (unlikely(err)) {
746 printk(KERN_ERR
747 "NILFS: error loading the latest checkpoint.\n");
748 return err;
749 }
750
751 err = nilfs_do_roll_forward(nilfs, sbi, ri);
752 if (unlikely(err))
753 goto failed;
754
755 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
756 err = nilfs_prepare_segment_for_recovery(nilfs, ri);
757 if (unlikely(err)) {
758 printk(KERN_ERR "NILFS: Error preparing segments for "
759 "recovery.\n");
760 goto failed;
761 }
762
763 err = nilfs_attach_segment_constructor(sbi, ri);
764 if (unlikely(err))
765 goto failed;
766
767 set_nilfs_discontinued(nilfs);
768 err = nilfs_construct_segment(sbi->s_super);
769 nilfs_detach_segment_constructor(sbi);
770
771 if (unlikely(err)) {
772 printk(KERN_ERR "NILFS: Oops! recovery failed. "
773 "(err=%d)\n", err);
774 goto failed;
775 }
776
777 nilfs_finish_roll_forward(nilfs, sbi, ri);
778 }
779
780 nilfs_detach_checkpoint(sbi);
781 return 0;
782
783 failed:
784 nilfs_detach_checkpoint(sbi);
785 nilfs_mdt_clear(nilfs->ns_cpfile);
786 nilfs_mdt_clear(nilfs->ns_sufile);
787 nilfs_mdt_clear(nilfs->ns_dat);
788 return err;
789}
790
791/**
792 * nilfs_search_super_root - search the latest valid super root
793 * @nilfs: the_nilfs
794 * @sbi: nilfs_sb_info
795 * @ri: pointer to a nilfs_recovery_info struct to store search results.
796 *
797 * nilfs_search_super_root() looks for the latest super-root from a partial
798 * segment pointed by the superblock. It sets up struct the_nilfs through
799 * this search. It fills nilfs_recovery_info (ri) required for recovery.
800 *
801 * Return Value: On success, 0 is returned. On error, one of the following
802 * negative error code is returned.
803 *
804 * %-EINVAL - No valid segment found
805 *
806 * %-EIO - I/O error
807 */
808int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi,
809 struct nilfs_recovery_info *ri)
810{
811 struct nilfs_segsum_info ssi;
812 sector_t pseg_start, pseg_end, sr_pseg_start = 0;
813 sector_t seg_start, seg_end; /* range of full segment (block number) */
814 u64 seg_seq;
815 __u64 segnum, nextnum = 0;
816 __u64 cno;
817 struct nilfs_segment_entry *ent;
818 LIST_HEAD(segments);
819 int empty_seg = 0, scan_newer = 0;
820 int ret;
821
822 pseg_start = nilfs->ns_last_pseg;
823 seg_seq = nilfs->ns_last_seq;
824 cno = nilfs->ns_last_cno;
825 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
826
827 /* Calculate range of segment */
828 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
829
830 for (;;) {
831 /* Load segment summary */
832 ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
833 if (ret) {
834 if (ret == NILFS_SEG_FAIL_IO)
835 goto failed;
836 goto strayed;
837 }
838 pseg_end = pseg_start + ssi.nblocks - 1;
839 if (unlikely(pseg_end > seg_end)) {
840 ret = NILFS_SEG_FAIL_CONSISTENCY;
841 goto strayed;
842 }
843
844 /* A valid partial segment */
845 ri->ri_pseg_start = pseg_start;
846 ri->ri_seq = seg_seq;
847 ri->ri_segnum = segnum;
848 nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
849 ri->ri_nextnum = nextnum;
850 empty_seg = 0;
851
852 if (!NILFS_SEG_HAS_SR(&ssi)) {
853 if (!scan_newer) {
854 /* This will never happen because a superblock
855 (last_segment) always points to a pseg
856 having a super root. */
857 ret = NILFS_SEG_FAIL_CONSISTENCY;
858 goto failed;
859 }
860 if (!ri->ri_lsegs_start && NILFS_SEG_LOGBGN(&ssi)) {
861 ri->ri_lsegs_start = pseg_start;
862 ri->ri_lsegs_start_seq = seg_seq;
863 }
864 if (NILFS_SEG_LOGEND(&ssi))
865 ri->ri_lsegs_end = pseg_start;
866 goto try_next_pseg;
867 }
868
869 /* A valid super root was found. */
870 ri->ri_cno = cno++;
871 ri->ri_super_root = pseg_end;
872 ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
873
874 nilfs_dispose_segment_list(&segments);
875 nilfs->ns_pseg_offset = (sr_pseg_start = pseg_start)
876 + ssi.nblocks - seg_start;
877 nilfs->ns_seg_seq = seg_seq;
878 nilfs->ns_segnum = segnum;
879 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
880 nilfs->ns_ctime = ssi.ctime;
881 nilfs->ns_nextnum = nextnum;
882
883 if (scan_newer)
884 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
885 else if (nilfs->ns_mount_state & NILFS_VALID_FS)
886 goto super_root_found;
887
888 scan_newer = 1;
889
890 /* reset region for roll-forward */
891 pseg_start += ssi.nblocks;
892 if (pseg_start < seg_end)
893 continue;
894 goto feed_segment;
895
896 try_next_pseg:
897 /* Standing on a course, or met an inconsistent state */
898 pseg_start += ssi.nblocks;
899 if (pseg_start < seg_end)
900 continue;
901 goto feed_segment;
902
903 strayed:
904 /* Off the trail */
905 if (!scan_newer)
906 /*
907 * This can happen if a checkpoint was written without
908 * barriers, or as a result of an I/O failure.
909 */
910 goto failed;
911
912 feed_segment:
913 /* Looking to the next full segment */
914 if (empty_seg++)
915 goto super_root_found; /* found a valid super root */
916
917 ent = nilfs_alloc_segment_entry(segnum);
918 if (unlikely(!ent)) {
919 ret = -ENOMEM;
920 goto failed;
921 }
922 list_add_tail(&ent->list, &segments);
923
924 seg_seq++;
925 segnum = nextnum;
926 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
927 pseg_start = seg_start;
928 }
929
930 super_root_found:
931 /* Updating pointers relating to the latest checkpoint */
932 list_splice(&segments, ri->ri_used_segments.prev);
933 nilfs->ns_last_pseg = sr_pseg_start;
934 nilfs->ns_last_seq = nilfs->ns_seg_seq;
935 nilfs->ns_last_cno = ri->ri_cno;
936 return 0;
937
938 failed:
939 nilfs_dispose_segment_list(&segments);
940 return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
941}
Linux 6.x block layer and io_uring tree(s)