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nilfs2: eliminate removal list of segments
[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;
0f3e1c7f
RK		 95 }
96 return -EINVAL;
97}
98
99static void store_segsum_info(struct nilfs_segsum_info *ssi,
100 struct nilfs_segment_summary *sum,
101 unsigned int blocksize)
102{
103 ssi->flags = le16_to_cpu(sum->ss_flags);
104 ssi->seg_seq = le64_to_cpu(sum->ss_seq);
105 ssi->ctime = le64_to_cpu(sum->ss_create);
106 ssi->next = le64_to_cpu(sum->ss_next);
107 ssi->nblocks = le32_to_cpu(sum->ss_nblocks);
108 ssi->nfinfo = le32_to_cpu(sum->ss_nfinfo);
109 ssi->sumbytes = le32_to_cpu(sum->ss_sumbytes);
110
111 ssi->nsumblk = DIV_ROUND_UP(ssi->sumbytes, blocksize);
112 ssi->nfileblk = ssi->nblocks - ssi->nsumblk - !!NILFS_SEG_HAS_SR(ssi);
113}
114
115/**
116 * calc_crc_cont - check CRC of blocks continuously
117 * @sbi: nilfs_sb_info
118 * @bhs: buffer head of start block
119 * @sum: place to store result
120 * @offset: offset bytes in the first block
121 * @check_bytes: number of bytes to be checked
122 * @start: DBN of start block
123 * @nblock: number of blocks to be checked
124 */
125static int calc_crc_cont(struct nilfs_sb_info *sbi, struct buffer_head *bhs,
126 u32 *sum, unsigned long offset, u64 check_bytes,
127 sector_t start, unsigned long nblock)
128{
129 unsigned long blocksize = sbi->s_super->s_blocksize;
130 unsigned long size;
131 u32 crc;
132
133 BUG_ON(offset >= blocksize);
134 check_bytes -= offset;
135 size = min_t(u64, check_bytes, blocksize - offset);
136 crc = crc32_le(sbi->s_nilfs->ns_crc_seed,
137 (unsigned char *)bhs->b_data + offset, size);
138 if (--nblock > 0) {
139 do {
140 struct buffer_head *bh
141 = sb_bread(sbi->s_super, ++start);
142 if (!bh)
143 return -EIO;
144 check_bytes -= size;
145 size = min_t(u64, check_bytes, blocksize);
146 crc = crc32_le(crc, bh->b_data, size);
147 brelse(bh);
148 } while (--nblock > 0);
149 }
150 *sum = crc;
151 return 0;
152}
153
154/**
155 * nilfs_read_super_root_block - read super root block
156 * @sb: super_block
157 * @sr_block: disk block number of the super root block
158 * @pbh: address of a buffer_head pointer to return super root buffer
159 * @check: CRC check flag
160 */
161int nilfs_read_super_root_block(struct super_block *sb, sector_t sr_block,
162 struct buffer_head **pbh, int check)
163{
164 struct buffer_head *bh_sr;
165 struct nilfs_super_root *sr;
166 u32 crc;
167 int ret;
168
169 *pbh = NULL;
170 bh_sr = sb_bread(sb, sr_block);
171 if (unlikely(!bh_sr)) {
172 ret = NILFS_SEG_FAIL_IO;
173 goto failed;
174 }
175
176 sr = (struct nilfs_super_root *)bh_sr->b_data;
177 if (check) {
178 unsigned bytes = le16_to_cpu(sr->sr_bytes);
179
180 if (bytes == 0 || bytes > sb->s_blocksize) {
181 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
182 goto failed_bh;
183 }
184 if (calc_crc_cont(NILFS_SB(sb), bh_sr, &crc,
185 sizeof(sr->sr_sum), bytes, sr_block, 1)) {
186 ret = NILFS_SEG_FAIL_IO;
187 goto failed_bh;
188 }
189 if (crc != le32_to_cpu(sr->sr_sum)) {
190 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
191 goto failed_bh;
192 }
193 }
194 *pbh = bh_sr;
195 return 0;
196
197 failed_bh:
198 brelse(bh_sr);
199
200 failed:
201 return nilfs_warn_segment_error(ret);
202}
203
204/**
205 * load_segment_summary - read segment summary of the specified partial segment
206 * @sbi: nilfs_sb_info
207 * @pseg_start: start disk block number of partial segment
208 * @seg_seq: sequence number requested
209 * @ssi: pointer to nilfs_segsum_info struct to store information
210 * @full_check: full check flag
211 * (0: only checks segment summary CRC, 1: data CRC)
212 */
213static int
214load_segment_summary(struct nilfs_sb_info *sbi, sector_t pseg_start,
215 u64 seg_seq, struct nilfs_segsum_info *ssi,
216 int full_check)
217{
218 struct buffer_head *bh_sum;
219 struct nilfs_segment_summary *sum;
220 unsigned long offset, nblock;
221 u64 check_bytes;
222 u32 crc, crc_sum;
223 int ret = NILFS_SEG_FAIL_IO;
224
225 bh_sum = sb_bread(sbi->s_super, pseg_start);
226 if (!bh_sum)
227 goto out;
228
229 sum = (struct nilfs_segment_summary *)bh_sum->b_data;
230
231 /* Check consistency of segment summary */
232 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) {
233 ret = NILFS_SEG_FAIL_MAGIC;
234 goto failed;
235 }
236 store_segsum_info(ssi, sum, sbi->s_super->s_blocksize);
237 if (seg_seq != ssi->seg_seq) {
238 ret = NILFS_SEG_FAIL_SEQ;
239 goto failed;
240 }
241 if (full_check) {
242 offset = sizeof(sum->ss_datasum);
243 check_bytes =
244 ((u64)ssi->nblocks << sbi->s_super->s_blocksize_bits);
245 nblock = ssi->nblocks;
246 crc_sum = le32_to_cpu(sum->ss_datasum);
247 ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
248 } else { /* only checks segment summary */
249 offset = sizeof(sum->ss_datasum) + sizeof(sum->ss_sumsum);
250 check_bytes = ssi->sumbytes;
251 nblock = ssi->nsumblk;
252 crc_sum = le32_to_cpu(sum->ss_sumsum);
253 ret = NILFS_SEG_FAIL_CHECKSUM_SEGSUM;
254 }
255
256 if (unlikely(nblock == 0 ||
257 nblock > sbi->s_nilfs->ns_blocks_per_segment)) {
258 /* This limits the number of blocks read in the CRC check */
259 ret = NILFS_SEG_FAIL_CONSISTENCY;
260 goto failed;
261 }
262 if (calc_crc_cont(sbi, bh_sum, &crc, offset, check_bytes,
263 pseg_start, nblock)) {
264 ret = NILFS_SEG_FAIL_IO;
265 goto failed;
266 }
267 if (crc == crc_sum)
268 ret = 0;
269 failed:
270 brelse(bh_sum);
271 out:
272 return ret;
273}
274
275static void *segsum_get(struct super_block *sb, struct buffer_head **pbh,
276 unsigned int *offset, unsigned int bytes)
277{
278 void *ptr;
279 sector_t blocknr;
280
281 BUG_ON((*pbh)->b_size < *offset);
282 if (bytes > (*pbh)->b_size - *offset) {
283 blocknr = (*pbh)->b_blocknr;
284 brelse(*pbh);
285 *pbh = sb_bread(sb, blocknr + 1);
286 if (unlikely(!*pbh))
287 return NULL;
288 *offset = 0;
289 }
290 ptr = (*pbh)->b_data + *offset;
291 *offset += bytes;
292 return ptr;
293}
294
295static void segsum_skip(struct super_block *sb, struct buffer_head **pbh,
296 unsigned int *offset, unsigned int bytes,
297 unsigned long count)
298{
299 unsigned int rest_item_in_current_block
300 = ((*pbh)->b_size - *offset) / bytes;
301
302 if (count <= rest_item_in_current_block) {
303 *offset += bytes * count;
304 } else {
305 sector_t blocknr = (*pbh)->b_blocknr;
306 unsigned int nitem_per_block = (*pbh)->b_size / bytes;
307 unsigned int bcnt;
308
309 count -= rest_item_in_current_block;
310 bcnt = DIV_ROUND_UP(count, nitem_per_block);
311 *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
312
313 brelse(*pbh);
314 *pbh = sb_bread(sb, blocknr + bcnt);
315 }
316}
317
318static int
319collect_blocks_from_segsum(struct nilfs_sb_info *sbi, sector_t sum_blocknr,
320 struct nilfs_segsum_info *ssi,
321 struct list_head *head)
322{
323 struct buffer_head *bh;
324 unsigned int offset;
325 unsigned long nfinfo = ssi->nfinfo;
326 sector_t blocknr = sum_blocknr + ssi->nsumblk;
327 ino_t ino;
328 int err = -EIO;
329
330 if (!nfinfo)
331 return 0;
332
333 bh = sb_bread(sbi->s_super, sum_blocknr);
334 if (unlikely(!bh))
335 goto out;
336
337 offset = le16_to_cpu(
338 ((struct nilfs_segment_summary *)bh->b_data)->ss_bytes);
339 for (;;) {
340 unsigned long nblocks, ndatablk, nnodeblk;
341 struct nilfs_finfo *finfo;
342
343 finfo = segsum_get(sbi->s_super, &bh, &offset, sizeof(*finfo));
344 if (unlikely(!finfo))
345 goto out;
346
347 ino = le64_to_cpu(finfo->fi_ino);
348 nblocks = le32_to_cpu(finfo->fi_nblocks);
349 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
350 nnodeblk = nblocks - ndatablk;
351
352 while (ndatablk-- > 0) {
353 struct nilfs_recovery_block *rb;
354 struct nilfs_binfo_v *binfo;
355
356 binfo = segsum_get(sbi->s_super, &bh, &offset,
357 sizeof(*binfo));
358 if (unlikely(!binfo))
359 goto out;
360
361 rb = kmalloc(sizeof(*rb), GFP_NOFS);
362 if (unlikely(!rb)) {
363 err = -ENOMEM;
364 goto out;
365 }
366 rb->ino = ino;
367 rb->blocknr = blocknr++;
368 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr);
369 rb->blkoff = le64_to_cpu(binfo->bi_blkoff);
370 /* INIT_LIST_HEAD(&rb->list); */
371 list_add_tail(&rb->list, head);
372 }
373 if (--nfinfo == 0)
374 break;
375 blocknr += nnodeblk; /* always 0 for the data sync segments */
376 segsum_skip(sbi->s_super, &bh, &offset, sizeof(__le64),
377 nnodeblk);
378 if (unlikely(!bh))
379 goto out;
380 }
381 err = 0;
382 out:
383 brelse(bh); /* brelse(NULL) is just ignored */
384 return err;
385}
386
387static void dispose_recovery_list(struct list_head *head)
388{
389 while (!list_empty(head)) {
390 struct nilfs_recovery_block *rb
391 = list_entry(head->next,
392 struct nilfs_recovery_block, list);
393 list_del(&rb->list);
394 kfree(rb);
395 }
396}
397
398void nilfs_dispose_segment_list(struct list_head *head)
399{
400 while (!list_empty(head)) {
401 struct nilfs_segment_entry *ent
402 = list_entry(head->next,
403 struct nilfs_segment_entry, list);
404 list_del(&ent->list);
405 nilfs_free_segment_entry(ent);
406 }
407}
408
409static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
85c2a74f 410 struct nilfs_sb_info *sbi,
0f3e1c7f
RK		 411 struct nilfs_recovery_info *ri)
412{
413 struct list_head *head = &ri->ri_used_segments;
414 struct nilfs_segment_entry *ent, *n;
415 struct inode *sufile = nilfs->ns_sufile;
416 __u64 segnum[4];
417 int err;
418 int i;
419
420 segnum[0] = nilfs->ns_segnum;
421 segnum[1] = nilfs->ns_nextnum;
422 segnum[2] = ri->ri_segnum;
423 segnum[3] = ri->ri_nextnum;
424
85c2a74f 425 nilfs_attach_writer(nilfs, sbi);
0f3e1c7f
RK		 426 /*
427 * Releasing the next segment of the latest super root.
428 * The next segment is invalidated by this recovery.
429 */
430 err = nilfs_sufile_free(sufile, segnum[1]);
431 if (unlikely(err))
432 goto failed;
433
434 err = -ENOMEM;
435 for (i = 1; i < 4; i++) {
436 ent = nilfs_alloc_segment_entry(segnum[i]);
437 if (unlikely(!ent))
438 goto failed;
439 list_add_tail(&ent->list, head);
440 }
441
442 /*
443 * Collecting segments written after the latest super root.
2c2e52fc 444 * These are marked dirty to avoid being reallocated in the next write.
0f3e1c7f
RK		 445 */
446 list_for_each_entry_safe(ent, n, head, list) {
c85399c2
RK		 447 if (ent->segnum != segnum[0]) {
448 err = nilfs_sufile_scrap(sufile, ent->segnum);
449 if (unlikely(err))
450 goto failed;
0f3e1c7f 451 }
2c2e52fc 452 list_del(&ent->list);
2c2e52fc 453 nilfs_free_segment_entry(ent);
0f3e1c7f 454 }
0f3e1c7f 455
0f3e1c7f
RK		 456 /* Allocate new segments for recovery */
457 err = nilfs_sufile_alloc(sufile, &segnum[0]);
458 if (unlikely(err))
459 goto failed;
460
461 nilfs->ns_pseg_offset = 0;
462 nilfs->ns_seg_seq = ri->ri_seq + 2;
463 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
0f3e1c7f
RK		 464
465 failed:
466 /* No need to recover sufile because it will be destroyed on error */
85c2a74f 467 nilfs_detach_writer(nilfs, sbi);
0f3e1c7f
RK		 468 return err;
469}
470
471static int nilfs_recovery_copy_block(struct nilfs_sb_info *sbi,
472 struct nilfs_recovery_block *rb,
473 struct page *page)
474{
475 struct buffer_head *bh_org;
476 void *kaddr;
477
478 bh_org = sb_bread(sbi->s_super, rb->blocknr);
479 if (unlikely(!bh_org))
480 return -EIO;
481
482 kaddr = kmap_atomic(page, KM_USER0);
483 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
484 kunmap_atomic(kaddr, KM_USER0);
485 brelse(bh_org);
486 return 0;
487}
488
489static int recover_dsync_blocks(struct nilfs_sb_info *sbi,
490 struct list_head *head,
491 unsigned long *nr_salvaged_blocks)
492{
493 struct inode *inode;
494 struct nilfs_recovery_block *rb, *n;
495 unsigned blocksize = sbi->s_super->s_blocksize;
496 struct page *page;
497 loff_t pos;
498 int err = 0, err2 = 0;
499
500 list_for_each_entry_safe(rb, n, head, list) {
501 inode = nilfs_iget(sbi->s_super, rb->ino);
502 if (IS_ERR(inode)) {
503 err = PTR_ERR(inode);
504 inode = NULL;
505 goto failed_inode;
506 }
507
508 pos = rb->blkoff << inode->i_blkbits;
509 page = NULL;
510 err = block_write_begin(NULL, inode->i_mapping, pos, blocksize,
511 0, &page, NULL, nilfs_get_block);
512 if (unlikely(err))
513 goto failed_inode;
514
515 err = nilfs_recovery_copy_block(sbi, rb, page);
516 if (unlikely(err))
517 goto failed_page;
518
519 err = nilfs_set_file_dirty(sbi, inode, 1);
520 if (unlikely(err))
521 goto failed_page;
522
523 block_write_end(NULL, inode->i_mapping, pos, blocksize,
524 blocksize, page, NULL);
525
526 unlock_page(page);
527 page_cache_release(page);
528
529 (*nr_salvaged_blocks)++;
530 goto next;
531
532 failed_page:
533 unlock_page(page);
534 page_cache_release(page);
535
536 failed_inode:
537 printk(KERN_WARNING
538 "NILFS warning: error recovering data block "
539 "(err=%d, ino=%lu, block-offset=%llu)\n",
540 err, rb->ino, (unsigned long long)rb->blkoff);
541 if (!err2)
542 err2 = err;
543 next:
544 iput(inode); /* iput(NULL) is just ignored */
545 list_del_init(&rb->list);
546 kfree(rb);
547 }
548 return err2;
549}
550
551/**
552 * nilfs_do_roll_forward - salvage logical segments newer than the latest
553 * checkpoint
554 * @sbi: nilfs_sb_info
555 * @nilfs: the_nilfs
556 * @ri: pointer to a nilfs_recovery_info
557 */
558static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
559 struct nilfs_sb_info *sbi,
560 struct nilfs_recovery_info *ri)
561{
562 struct nilfs_segsum_info ssi;
563 sector_t pseg_start;
564 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
565 unsigned long nsalvaged_blocks = 0;
566 u64 seg_seq;
567 __u64 segnum, nextnum = 0;
568 int empty_seg = 0;
569 int err = 0, ret;
570 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
571 enum {
572 RF_INIT_ST,
573 RF_DSYNC_ST, /* scanning data-sync segments */
574 };
575 int state = RF_INIT_ST;
576
577 nilfs_attach_writer(nilfs, sbi);
578 pseg_start = ri->ri_lsegs_start;
579 seg_seq = ri->ri_lsegs_start_seq;
580 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
581 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
582
583 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
584
585 ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
586 if (ret) {
587 if (ret == NILFS_SEG_FAIL_IO) {
588 err = -EIO;
589 goto failed;
590 }
591 goto strayed;
592 }
593 if (unlikely(NILFS_SEG_HAS_SR(&ssi)))
594 goto confused;
595
596 /* Found a valid partial segment; do recovery actions */
597 nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
598 empty_seg = 0;
599 nilfs->ns_ctime = ssi.ctime;
600 if (!(ssi.flags & NILFS_SS_GC))
601 nilfs->ns_nongc_ctime = ssi.ctime;
602
603 switch (state) {
604 case RF_INIT_ST:
605 if (!NILFS_SEG_LOGBGN(&ssi) || !NILFS_SEG_DSYNC(&ssi))
606 goto try_next_pseg;
607 state = RF_DSYNC_ST;
608 /* Fall through */
609 case RF_DSYNC_ST:
610 if (!NILFS_SEG_DSYNC(&ssi))
611 goto confused;
612
613 err = collect_blocks_from_segsum(
614 sbi, pseg_start, &ssi, &dsync_blocks);
615 if (unlikely(err))
616 goto failed;
617 if (NILFS_SEG_LOGEND(&ssi)) {
618 err = recover_dsync_blocks(
619 sbi, &dsync_blocks, &nsalvaged_blocks);
620 if (unlikely(err))
621 goto failed;
622 state = RF_INIT_ST;
623 }
624 break; /* Fall through to try_next_pseg */
625 }
626
627 try_next_pseg:
628 if (pseg_start == ri->ri_lsegs_end)
629 break;
630 pseg_start += ssi.nblocks;
631 if (pseg_start < seg_end)
632 continue;
633 goto feed_segment;
634
635 strayed:
636 if (pseg_start == ri->ri_lsegs_end)
637 break;
638
639 feed_segment:
640 /* Looking to the next full segment */
641 if (empty_seg++)
642 break;
643 seg_seq++;
644 segnum = nextnum;
645 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
646 pseg_start = seg_start;
647 }
648
649 if (nsalvaged_blocks) {
650 printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n",
651 sbi->s_super->s_id, nsalvaged_blocks);
652 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
653 }
654 out:
655 dispose_recovery_list(&dsync_blocks);
656 nilfs_detach_writer(sbi->s_nilfs, sbi);
657 return err;
658
659 confused:
660 err = -EINVAL;
661 failed:
662 printk(KERN_ERR
663 "NILFS (device %s): Error roll-forwarding "
664 "(err=%d, pseg block=%llu). ",
665 sbi->s_super->s_id, err, (unsigned long long)pseg_start);
666 goto out;
667}
668
669static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
670 struct nilfs_sb_info *sbi,
671 struct nilfs_recovery_info *ri)
672{
673 struct buffer_head *bh;
674 int err;
675
676 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) !=
677 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root))
678 return;
679
680 bh = sb_getblk(sbi->s_super, ri->ri_lsegs_start);
681 BUG_ON(!bh);
682 memset(bh->b_data, 0, bh->b_size);
683 set_buffer_dirty(bh);
684 err = sync_dirty_buffer(bh);
685 if (unlikely(err))
686 printk(KERN_WARNING
687 "NILFS warning: buffer sync write failed during "
688 "post-cleaning of recovery.\n");
689 brelse(bh);
690}
691
692/**
693 * nilfs_recover_logical_segments - salvage logical segments written after
694 * the latest super root
695 * @nilfs: the_nilfs
696 * @sbi: nilfs_sb_info
697 * @ri: pointer to a nilfs_recovery_info struct to store search results.
698 *
699 * Return Value: On success, 0 is returned. On error, one of the following
700 * negative error code is returned.
701 *
702 * %-EINVAL - Inconsistent filesystem state.
703 *
704 * %-EIO - I/O error
705 *
706 * %-ENOSPC - No space left on device (only in a panic state).
707 *
708 * %-ERESTARTSYS - Interrupted.
709 *
710 * %-ENOMEM - Insufficient memory available.
711 */
712int nilfs_recover_logical_segments(struct the_nilfs *nilfs,
713 struct nilfs_sb_info *sbi,
714 struct nilfs_recovery_info *ri)
715{
716 int err;
717
718 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
719 return 0;
720
721 err = nilfs_attach_checkpoint(sbi, ri->ri_cno);
722 if (unlikely(err)) {
723 printk(KERN_ERR
724 "NILFS: error loading the latest checkpoint.\n");
725 return err;
726 }
727
728 err = nilfs_do_roll_forward(nilfs, sbi, ri);
729 if (unlikely(err))
730 goto failed;
731
732 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
85c2a74f 733 err = nilfs_prepare_segment_for_recovery(nilfs, sbi, ri);
0f3e1c7f
RK		 734 if (unlikely(err)) {
735 printk(KERN_ERR "NILFS: Error preparing segments for "
736 "recovery.\n");
737 goto failed;
738 }
739
cece5520 740 err = nilfs_attach_segment_constructor(sbi);
0f3e1c7f
RK		 741 if (unlikely(err))
742 goto failed;
743
744 set_nilfs_discontinued(nilfs);
745 err = nilfs_construct_segment(sbi->s_super);
746 nilfs_detach_segment_constructor(sbi);
747
748 if (unlikely(err)) {
749 printk(KERN_ERR "NILFS: Oops! recovery failed. "
750 "(err=%d)\n", err);
751 goto failed;
752 }
753
754 nilfs_finish_roll_forward(nilfs, sbi, ri);
755 }
756
757 nilfs_detach_checkpoint(sbi);
758 return 0;
759
760 failed:
761 nilfs_detach_checkpoint(sbi);
762 nilfs_mdt_clear(nilfs->ns_cpfile);
763 nilfs_mdt_clear(nilfs->ns_sufile);
764 nilfs_mdt_clear(nilfs->ns_dat);
765 return err;
766}
767
768/**
769 * nilfs_search_super_root - search the latest valid super root
770 * @nilfs: the_nilfs
771 * @sbi: nilfs_sb_info
772 * @ri: pointer to a nilfs_recovery_info struct to store search results.
773 *
774 * nilfs_search_super_root() looks for the latest super-root from a partial
775 * segment pointed by the superblock. It sets up struct the_nilfs through
776 * this search. It fills nilfs_recovery_info (ri) required for recovery.
777 *
778 * Return Value: On success, 0 is returned. On error, one of the following
779 * negative error code is returned.
780 *
781 * %-EINVAL - No valid segment found
782 *
783 * %-EIO - I/O error
784 */
785int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi,
786 struct nilfs_recovery_info *ri)
787{
788 struct nilfs_segsum_info ssi;
789 sector_t pseg_start, pseg_end, sr_pseg_start = 0;
790 sector_t seg_start, seg_end; /* range of full segment (block number) */
791 u64 seg_seq;
792 __u64 segnum, nextnum = 0;
793 __u64 cno;
794 struct nilfs_segment_entry *ent;
795 LIST_HEAD(segments);
796 int empty_seg = 0, scan_newer = 0;
797 int ret;
798
799 pseg_start = nilfs->ns_last_pseg;
800 seg_seq = nilfs->ns_last_seq;
801 cno = nilfs->ns_last_cno;
802 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
803
804 /* Calculate range of segment */
805 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
806
807 for (;;) {
808 /* Load segment summary */
809 ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
810 if (ret) {
811 if (ret == NILFS_SEG_FAIL_IO)
812 goto failed;
813 goto strayed;
814 }
815 pseg_end = pseg_start + ssi.nblocks - 1;
816 if (unlikely(pseg_end > seg_end)) {
817 ret = NILFS_SEG_FAIL_CONSISTENCY;
818 goto strayed;
819 }
820
821 /* A valid partial segment */
822 ri->ri_pseg_start = pseg_start;
823 ri->ri_seq = seg_seq;
824 ri->ri_segnum = segnum;
825 nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
826 ri->ri_nextnum = nextnum;
827 empty_seg = 0;
828
829 if (!NILFS_SEG_HAS_SR(&ssi)) {
830 if (!scan_newer) {
831 /* This will never happen because a superblock
832 (last_segment) always points to a pseg
833 having a super root. */
834 ret = NILFS_SEG_FAIL_CONSISTENCY;
835 goto failed;
836 }
837 if (!ri->ri_lsegs_start && NILFS_SEG_LOGBGN(&ssi)) {
838 ri->ri_lsegs_start = pseg_start;
839 ri->ri_lsegs_start_seq = seg_seq;
840 }
841 if (NILFS_SEG_LOGEND(&ssi))
842 ri->ri_lsegs_end = pseg_start;
843 goto try_next_pseg;
844 }
845
846 /* A valid super root was found. */
847 ri->ri_cno = cno++;
848 ri->ri_super_root = pseg_end;
849 ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
850
851 nilfs_dispose_segment_list(&segments);
852 nilfs->ns_pseg_offset = (sr_pseg_start = pseg_start)
853 + ssi.nblocks - seg_start;
854 nilfs->ns_seg_seq = seg_seq;
855 nilfs->ns_segnum = segnum;
856 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
857 nilfs->ns_ctime = ssi.ctime;
858 nilfs->ns_nextnum = nextnum;
859
860 if (scan_newer)
861 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
2c2e52fc 862 else {
2c2e52fc
RK		 863 if (nilfs->ns_mount_state & NILFS_VALID_FS)
864 goto super_root_found;
865 scan_newer = 1;
866 }
0f3e1c7f
RK		 867
868 /* reset region for roll-forward */
869 pseg_start += ssi.nblocks;
870 if (pseg_start < seg_end)
871 continue;
872 goto feed_segment;
873
874 try_next_pseg:
875 /* Standing on a course, or met an inconsistent state */
876 pseg_start += ssi.nblocks;
877 if (pseg_start < seg_end)
878 continue;
879 goto feed_segment;
880
881 strayed:
882 /* Off the trail */
883 if (!scan_newer)
884 /*
885 * This can happen if a checkpoint was written without
886 * barriers, or as a result of an I/O failure.
887 */
888 goto failed;
889
890 feed_segment:
891 /* Looking to the next full segment */
892 if (empty_seg++)
893 goto super_root_found; /* found a valid super root */
894
895 ent = nilfs_alloc_segment_entry(segnum);
896 if (unlikely(!ent)) {
897 ret = -ENOMEM;
898 goto failed;
899 }
900 list_add_tail(&ent->list, &segments);
901
902 seg_seq++;
903 segnum = nextnum;
904 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
905 pseg_start = seg_start;
906 }
907
908 super_root_found:
909 /* Updating pointers relating to the latest checkpoint */
910 list_splice(&segments, ri->ri_used_segments.prev);
911 nilfs->ns_last_pseg = sr_pseg_start;
912 nilfs->ns_last_seq = nilfs->ns_seg_seq;
913 nilfs->ns_last_cno = ri->ri_cno;
914 return 0;
915
916 failed:
917 nilfs_dispose_segment_list(&segments);
918 return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
919}
Linux 6.x block layer and io_uring tree(s)