1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * 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 */
24enum {
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 */
36struct 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
48static 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 * Return: 0 on success, or %-EIO if an I/O error occurs.
93 */
94static int nilfs_compute_checksum(struct the_nilfs *nilfs,
95 struct buffer_head *bhs, u32 *sum,
96 unsigned long offset, u64 check_bytes,
97 sector_t start, unsigned long nblock)
98{
99 unsigned int blocksize = nilfs->ns_blocksize;
100 unsigned long size;
101 u32 crc;
102
103 BUG_ON(offset >= blocksize);
104 check_bytes -= offset;
105 size = min_t(u64, check_bytes, blocksize - offset);
106 crc = crc32_le(crc: nilfs->ns_crc_seed,
107 p: (unsigned char *)bhs->b_data + offset, len: size);
108 if (--nblock > 0) {
109 do {
110 struct buffer_head *bh;
111
112 bh = __bread(bdev: nilfs->ns_bdev, block: ++start, size: blocksize);
113 if (!bh)
114 return -EIO;
115 check_bytes -= size;
116 size = min_t(u64, check_bytes, blocksize);
117 crc = crc32_le(crc, p: bh->b_data, len: size);
118 brelse(bh);
119 } while (--nblock > 0);
120 }
121 *sum = crc;
122 return 0;
123}
124
125/**
126 * nilfs_read_super_root_block - read super root block
127 * @nilfs: nilfs object
128 * @sr_block: disk block number of the super root block
129 * @pbh: address of a buffer_head pointer to return super root buffer
130 * @check: CRC check flag
131 *
132 * Return: 0 on success, or one of the following negative error codes on
133 * failure:
134 * * %-EINVAL - Super root block corrupted.
135 * * %-EIO - I/O error.
136 */
137int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
138 struct buffer_head **pbh, int check)
139{
140 struct buffer_head *bh_sr;
141 struct nilfs_super_root *sr;
142 u32 crc;
143 int ret;
144
145 *pbh = NULL;
146 bh_sr = __bread(bdev: nilfs->ns_bdev, block: sr_block, size: nilfs->ns_blocksize);
147 if (unlikely(!bh_sr)) {
148 ret = NILFS_SEG_FAIL_IO;
149 goto failed;
150 }
151
152 sr = (struct nilfs_super_root *)bh_sr->b_data;
153 if (check) {
154 unsigned int bytes = le16_to_cpu(sr->sr_bytes);
155
156 if (bytes == 0 || bytes > nilfs->ns_blocksize) {
157 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
158 goto failed_bh;
159 }
160 if (nilfs_compute_checksum(
161 nilfs, bhs: bh_sr, sum: &crc, offset: sizeof(sr->sr_sum), check_bytes: bytes,
162 start: sr_block, nblock: 1)) {
163 ret = NILFS_SEG_FAIL_IO;
164 goto failed_bh;
165 }
166 if (crc != le32_to_cpu(sr->sr_sum)) {
167 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
168 goto failed_bh;
169 }
170 }
171 *pbh = bh_sr;
172 return 0;
173
174 failed_bh:
175 brelse(bh: bh_sr);
176
177 failed:
178 return nilfs_warn_segment_error(sb: nilfs->ns_sb, err: ret);
179}
180
181/**
182 * nilfs_read_log_header - read summary header of the specified log
183 * @nilfs: nilfs object
184 * @start_blocknr: start block number of the log
185 * @sum: pointer to return segment summary structure
186 *
187 * Return: Buffer head pointer, or NULL if an I/O error occurs.
188 */
189static struct buffer_head *
190nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr,
191 struct nilfs_segment_summary **sum)
192{
193 struct buffer_head *bh_sum;
194
195 bh_sum = __bread(bdev: nilfs->ns_bdev, block: start_blocknr, size: nilfs->ns_blocksize);
196 if (bh_sum)
197 *sum = (struct nilfs_segment_summary *)bh_sum->b_data;
198 return bh_sum;
199}
200
201/**
202 * nilfs_validate_log - verify consistency of log
203 * @nilfs: nilfs object
204 * @seg_seq: sequence number of segment
205 * @bh_sum: buffer head of summary block
206 * @sum: segment summary struct
207 *
208 * Return: 0 on success, or one of the following internal codes on failure:
209 * * %NILFS_SEG_FAIL_MAGIC - Magic number mismatch.
210 * * %NILFS_SEG_FAIL_SEQ - Sequence number mismatch.
211 * * %NIFLS_SEG_FAIL_CONSISTENCY - Block count out of range.
212 * * %NILFS_SEG_FAIL_IO - I/O error.
213 * * %NILFS_SEG_FAIL_CHECKSUM_FULL - Full log checksum verification failed.
214 */
215static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
216 struct buffer_head *bh_sum,
217 struct nilfs_segment_summary *sum)
218{
219 unsigned long nblock;
220 u32 crc;
221 int ret;
222
223 ret = NILFS_SEG_FAIL_MAGIC;
224 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC)
225 goto out;
226
227 ret = NILFS_SEG_FAIL_SEQ;
228 if (le64_to_cpu(sum->ss_seq) != seg_seq)
229 goto out;
230
231 nblock = le32_to_cpu(sum->ss_nblocks);
232 ret = NILFS_SEG_FAIL_CONSISTENCY;
233 if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment))
234 /* This limits the number of blocks read in the CRC check */
235 goto out;
236
237 ret = NILFS_SEG_FAIL_IO;
238 if (nilfs_compute_checksum(nilfs, bhs: bh_sum, sum: &crc, offset: sizeof(sum->ss_datasum),
239 check_bytes: ((u64)nblock << nilfs->ns_blocksize_bits),
240 start: bh_sum->b_blocknr, nblock))
241 goto out;
242
243 ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
244 if (crc != le32_to_cpu(sum->ss_datasum))
245 goto out;
246 ret = 0;
247out:
248 return ret;
249}
250
251/**
252 * nilfs_read_summary_info - read an item on summary blocks of a log
253 * @nilfs: nilfs object
254 * @pbh: the current buffer head on summary blocks [in, out]
255 * @offset: the current byte offset on summary blocks [in, out]
256 * @bytes: byte size of the item to be read
257 *
258 * Return: Kernel space address of current segment summary entry, or
259 * NULL if an I/O error occurs.
260 */
261static void *nilfs_read_summary_info(struct the_nilfs *nilfs,
262 struct buffer_head **pbh,
263 unsigned int *offset, unsigned int bytes)
264{
265 void *ptr;
266 sector_t blocknr;
267
268 BUG_ON((*pbh)->b_size < *offset);
269 if (bytes > (*pbh)->b_size - *offset) {
270 blocknr = (*pbh)->b_blocknr;
271 brelse(bh: *pbh);
272 *pbh = __bread(bdev: nilfs->ns_bdev, block: blocknr + 1,
273 size: nilfs->ns_blocksize);
274 if (unlikely(!*pbh))
275 return NULL;
276 *offset = 0;
277 }
278 ptr = (*pbh)->b_data + *offset;
279 *offset += bytes;
280 return ptr;
281}
282
283/**
284 * nilfs_skip_summary_info - skip items on summary blocks of a log
285 * @nilfs: nilfs object
286 * @pbh: the current buffer head on summary blocks [in, out]
287 * @offset: the current byte offset on summary blocks [in, out]
288 * @bytes: byte size of the item to be skipped
289 * @count: number of items to be skipped
290 */
291static void nilfs_skip_summary_info(struct the_nilfs *nilfs,
292 struct buffer_head **pbh,
293 unsigned int *offset, unsigned int bytes,
294 unsigned long count)
295{
296 unsigned int rest_item_in_current_block
297 = ((*pbh)->b_size - *offset) / bytes;
298
299 if (count <= rest_item_in_current_block) {
300 *offset += bytes * count;
301 } else {
302 sector_t blocknr = (*pbh)->b_blocknr;
303 unsigned int nitem_per_block = (*pbh)->b_size / bytes;
304 unsigned int bcnt;
305
306 count -= rest_item_in_current_block;
307 bcnt = DIV_ROUND_UP(count, nitem_per_block);
308 *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
309
310 brelse(bh: *pbh);
311 *pbh = __bread(bdev: nilfs->ns_bdev, block: blocknr + bcnt,
312 size: nilfs->ns_blocksize);
313 }
314}
315
316/**
317 * nilfs_scan_dsync_log - get block information of a log written for data sync
318 * @nilfs: nilfs object
319 * @start_blocknr: start block number of the log
320 * @sum: log summary information
321 * @head: list head to add nilfs_recovery_block struct
322 *
323 * Return: 0 on success, or one of the following negative error codes on
324 * failure:
325 * * %-EIO - I/O error.
326 * * %-ENOMEM - Insufficient memory available.
327 */
328static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr,
329 struct nilfs_segment_summary *sum,
330 struct list_head *head)
331{
332 struct buffer_head *bh;
333 unsigned int offset;
334 u32 nfinfo, sumbytes;
335 sector_t blocknr;
336 ino_t ino;
337 int err = -EIO;
338
339 nfinfo = le32_to_cpu(sum->ss_nfinfo);
340 if (!nfinfo)
341 return 0;
342
343 sumbytes = le32_to_cpu(sum->ss_sumbytes);
344 blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize);
345 bh = __bread(bdev: nilfs->ns_bdev, block: start_blocknr, size: nilfs->ns_blocksize);
346 if (unlikely(!bh))
347 goto out;
348
349 offset = le16_to_cpu(sum->ss_bytes);
350 for (;;) {
351 unsigned long nblocks, ndatablk, nnodeblk;
352 struct nilfs_finfo *finfo;
353
354 finfo = nilfs_read_summary_info(nilfs, pbh: &bh, offset: &offset,
355 bytes: sizeof(*finfo));
356 if (unlikely(!finfo))
357 goto out;
358
359 ino = le64_to_cpu(finfo->fi_ino);
360 nblocks = le32_to_cpu(finfo->fi_nblocks);
361 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
362 nnodeblk = nblocks - ndatablk;
363
364 while (ndatablk-- > 0) {
365 struct nilfs_recovery_block *rb;
366 struct nilfs_binfo_v *binfo;
367
368 binfo = nilfs_read_summary_info(nilfs, pbh: &bh, offset: &offset,
369 bytes: sizeof(*binfo));
370 if (unlikely(!binfo))
371 goto out;
372
373 rb = kmalloc(sizeof(*rb), GFP_NOFS);
374 if (unlikely(!rb)) {
375 err = -ENOMEM;
376 goto out;
377 }
378 rb->ino = ino;
379 rb->blocknr = blocknr++;
380 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr);
381 rb->blkoff = le64_to_cpu(binfo->bi_blkoff);
382 /* INIT_LIST_HEAD(&rb->list); */
383 list_add_tail(new: &rb->list, head);
384 }
385 if (--nfinfo == 0)
386 break;
387 blocknr += nnodeblk; /* always 0 for data sync logs */
388 nilfs_skip_summary_info(nilfs, pbh: &bh, offset: &offset, bytes: sizeof(__le64),
389 count: nnodeblk);
390 if (unlikely(!bh))
391 goto out;
392 }
393 err = 0;
394 out:
395 brelse(bh); /* brelse(NULL) is just ignored */
396 return err;
397}
398
399static void dispose_recovery_list(struct list_head *head)
400{
401 while (!list_empty(head)) {
402 struct nilfs_recovery_block *rb;
403
404 rb = list_first_entry(head, struct nilfs_recovery_block, list);
405 list_del(entry: &rb->list);
406 kfree(objp: rb);
407 }
408}
409
410struct nilfs_segment_entry {
411 struct list_head list;
412 __u64 segnum;
413};
414
415static int nilfs_segment_list_add(struct list_head *head, __u64 segnum)
416{
417 struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS);
418
419 if (unlikely(!ent))
420 return -ENOMEM;
421
422 ent->segnum = segnum;
423 INIT_LIST_HEAD(list: &ent->list);
424 list_add_tail(new: &ent->list, head);
425 return 0;
426}
427
428void nilfs_dispose_segment_list(struct list_head *head)
429{
430 while (!list_empty(head)) {
431 struct nilfs_segment_entry *ent;
432
433 ent = list_first_entry(head, struct nilfs_segment_entry, list);
434 list_del(entry: &ent->list);
435 kfree(objp: ent);
436 }
437}
438
439static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
440 struct super_block *sb,
441 struct nilfs_recovery_info *ri)
442{
443 struct list_head *head = &ri->ri_used_segments;
444 struct nilfs_segment_entry *ent, *n;
445 struct inode *sufile = nilfs->ns_sufile;
446 __u64 segnum[4];
447 int err;
448 int i;
449
450 segnum[0] = nilfs->ns_segnum;
451 segnum[1] = nilfs->ns_nextnum;
452 segnum[2] = ri->ri_segnum;
453 segnum[3] = ri->ri_nextnum;
454
455 /*
456 * Releasing the next segment of the latest super root.
457 * The next segment is invalidated by this recovery.
458 */
459 err = nilfs_sufile_free(sufile, segnum: segnum[1]);
460 if (unlikely(err)) {
461 if (err == -ENOENT) {
462 nilfs_err(sb,
463 "checkpoint log inconsistency at block %llu (segment %llu): next segment %llu is unallocated",
464 (unsigned long long)nilfs->ns_last_pseg,
465 (unsigned long long)nilfs->ns_segnum,
466 (unsigned long long)segnum[1]);
467 err = -EINVAL;
468 }
469 goto failed;
470 }
471
472 for (i = 1; i < 4; i++) {
473 err = nilfs_segment_list_add(head, segnum: segnum[i]);
474 if (unlikely(err))
475 goto failed;
476 }
477
478 /*
479 * Collecting segments written after the latest super root.
480 * These are marked dirty to avoid being reallocated in the next write.
481 */
482 list_for_each_entry_safe(ent, n, head, list) {
483 if (ent->segnum != segnum[0]) {
484 err = nilfs_sufile_scrap(sufile, segnum: ent->segnum);
485 if (unlikely(err))
486 goto failed;
487 }
488 list_del(entry: &ent->list);
489 kfree(objp: ent);
490 }
491
492 /* Allocate new segments for recovery */
493 err = nilfs_sufile_alloc(sufile, &segnum[0]);
494 if (unlikely(err))
495 goto failed;
496
497 nilfs->ns_pseg_offset = 0;
498 nilfs->ns_seg_seq = ri->ri_seq + 2;
499 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
500
501 failed:
502 /* No need to recover sufile because it will be destroyed on error */
503 return err;
504}
505
506static int nilfs_recovery_copy_block(struct the_nilfs *nilfs,
507 struct nilfs_recovery_block *rb,
508 loff_t pos, struct folio *folio)
509{
510 struct buffer_head *bh_org;
511 size_t from = offset_in_folio(folio, pos);
512
513 bh_org = __bread(bdev: nilfs->ns_bdev, block: rb->blocknr, size: nilfs->ns_blocksize);
514 if (unlikely(!bh_org))
515 return -EIO;
516
517 memcpy_to_folio(folio, offset: from, from: bh_org->b_data, len: bh_org->b_size);
518 brelse(bh: bh_org);
519 return 0;
520}
521
522static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs,
523 struct super_block *sb,
524 struct nilfs_root *root,
525 struct list_head *head,
526 unsigned long *nr_salvaged_blocks)
527{
528 struct inode *inode;
529 struct nilfs_recovery_block *rb, *n;
530 unsigned int blocksize = nilfs->ns_blocksize;
531 struct folio *folio;
532 loff_t pos;
533 int err = 0, err2 = 0;
534
535 list_for_each_entry_safe(rb, n, head, list) {
536 inode = nilfs_iget(sb, root, ino: rb->ino);
537 if (IS_ERR(ptr: inode)) {
538 err = PTR_ERR(ptr: inode);
539 inode = NULL;
540 goto failed_inode;
541 }
542
543 pos = rb->blkoff << inode->i_blkbits;
544 err = block_write_begin(mapping: inode->i_mapping, pos, len: blocksize,
545 foliop: &folio, get_block: nilfs_get_block);
546 if (unlikely(err)) {
547 loff_t isize = inode->i_size;
548
549 if (pos + blocksize > isize)
550 nilfs_write_failed(mapping: inode->i_mapping,
551 to: pos + blocksize);
552 goto failed_inode;
553 }
554
555 err = nilfs_recovery_copy_block(nilfs, rb, pos, folio);
556 if (unlikely(err))
557 goto failed_folio;
558
559 err = nilfs_set_file_dirty(inode, nr_dirty: 1);
560 if (unlikely(err))
561 goto failed_folio;
562
563 block_write_end(pos, len: blocksize, copied: blocksize, folio);
564
565 folio_unlock(folio);
566 folio_put(folio);
567
568 (*nr_salvaged_blocks)++;
569 goto next;
570
571 failed_folio:
572 folio_unlock(folio);
573 folio_put(folio);
574
575 failed_inode:
576 nilfs_warn(sb,
577 "error %d recovering data block (ino=%lu, block-offset=%llu)",
578 err, (unsigned long)rb->ino,
579 (unsigned long long)rb->blkoff);
580 if (!err2)
581 err2 = err;
582 next:
583 iput(inode); /* iput(NULL) is just ignored */
584 list_del_init(entry: &rb->list);
585 kfree(objp: rb);
586 }
587 return err2;
588}
589
590/**
591 * nilfs_do_roll_forward - salvage logical segments newer than the latest
592 * checkpoint
593 * @nilfs: nilfs object
594 * @sb: super block instance
595 * @root: NILFS root instance
596 * @ri: pointer to a nilfs_recovery_info
597 *
598 * Return: 0 on success, or one of the following negative error codes on
599 * failure:
600 * * %-EINVAL - Log format error.
601 * * %-EIO - I/O error.
602 * * %-ENOMEM - Insufficient memory available.
603 */
604static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
605 struct super_block *sb,
606 struct nilfs_root *root,
607 struct nilfs_recovery_info *ri)
608{
609 struct buffer_head *bh_sum = NULL;
610 struct nilfs_segment_summary *sum = NULL;
611 sector_t pseg_start;
612 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
613 unsigned long nsalvaged_blocks = 0;
614 unsigned int flags;
615 u64 seg_seq;
616 __u64 segnum, nextnum = 0;
617 int empty_seg = 0;
618 int err = 0, ret;
619 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
620 enum {
621 RF_INIT_ST,
622 RF_DSYNC_ST, /* scanning data-sync segments */
623 };
624 int state = RF_INIT_ST;
625
626 pseg_start = ri->ri_lsegs_start;
627 seg_seq = ri->ri_lsegs_start_seq;
628 segnum = nilfs_get_segnum_of_block(nilfs, blocknr: pseg_start);
629 nilfs_get_segment_range(nilfs, segnum, seg_start: &seg_start, seg_end: &seg_end);
630
631 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
632 brelse(bh: bh_sum);
633 bh_sum = nilfs_read_log_header(nilfs, start_blocknr: pseg_start, sum: &sum);
634 if (!bh_sum) {
635 err = -EIO;
636 goto failed;
637 }
638
639 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
640 if (ret) {
641 if (ret == NILFS_SEG_FAIL_IO) {
642 err = -EIO;
643 goto failed;
644 }
645 goto strayed;
646 }
647
648 flags = le16_to_cpu(sum->ss_flags);
649 if (flags & NILFS_SS_SR)
650 goto confused;
651
652 /* Found a valid partial segment; do recovery actions */
653 nextnum = nilfs_get_segnum_of_block(nilfs,
654 le64_to_cpu(sum->ss_next));
655 empty_seg = 0;
656 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
657 if (!(flags & NILFS_SS_GC))
658 nilfs->ns_nongc_ctime = nilfs->ns_ctime;
659
660 switch (state) {
661 case RF_INIT_ST:
662 if (!(flags & NILFS_SS_LOGBGN) ||
663 !(flags & NILFS_SS_SYNDT))
664 goto try_next_pseg;
665 state = RF_DSYNC_ST;
666 fallthrough;
667 case RF_DSYNC_ST:
668 if (!(flags & NILFS_SS_SYNDT))
669 goto confused;
670
671 err = nilfs_scan_dsync_log(nilfs, start_blocknr: pseg_start, sum,
672 head: &dsync_blocks);
673 if (unlikely(err))
674 goto failed;
675 if (flags & NILFS_SS_LOGEND) {
676 err = nilfs_recover_dsync_blocks(
677 nilfs, sb, root, head: &dsync_blocks,
678 nr_salvaged_blocks: &nsalvaged_blocks);
679 if (unlikely(err))
680 goto failed;
681 state = RF_INIT_ST;
682 }
683 break; /* Fall through to try_next_pseg */
684 }
685
686 try_next_pseg:
687 if (pseg_start == ri->ri_lsegs_end)
688 break;
689 pseg_start += le32_to_cpu(sum->ss_nblocks);
690 if (pseg_start < seg_end)
691 continue;
692 goto feed_segment;
693
694 strayed:
695 if (pseg_start == ri->ri_lsegs_end)
696 break;
697
698 feed_segment:
699 /* Looking to the next full segment */
700 if (empty_seg++)
701 break;
702 seg_seq++;
703 segnum = nextnum;
704 nilfs_get_segment_range(nilfs, segnum, seg_start: &seg_start, seg_end: &seg_end);
705 pseg_start = seg_start;
706 }
707
708 if (nsalvaged_blocks) {
709 nilfs_info(sb, "salvaged %lu blocks", nsalvaged_blocks);
710 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
711 }
712 out:
713 brelse(bh: bh_sum);
714 dispose_recovery_list(head: &dsync_blocks);
715 return err;
716
717 confused:
718 err = -EINVAL;
719 failed:
720 nilfs_err(sb,
721 "error %d roll-forwarding partial segment at blocknr = %llu",
722 err, (unsigned long long)pseg_start);
723 goto out;
724}
725
726static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
727 struct nilfs_recovery_info *ri)
728{
729 struct buffer_head *bh;
730 int err;
731
732 if (nilfs_get_segnum_of_block(nilfs, blocknr: ri->ri_lsegs_start) !=
733 nilfs_get_segnum_of_block(nilfs, blocknr: ri->ri_super_root))
734 return;
735
736 bh = __getblk(bdev: nilfs->ns_bdev, block: ri->ri_lsegs_start, size: nilfs->ns_blocksize);
737 if (WARN_ON(!bh))
738 return; /* should never happen */
739
740 lock_buffer(bh);
741 memset(bh->b_data, 0, bh->b_size);
742 set_buffer_uptodate(bh);
743 set_buffer_dirty(bh);
744 unlock_buffer(bh);
745
746 err = sync_dirty_buffer(bh);
747 if (unlikely(err))
748 nilfs_warn(nilfs->ns_sb,
749 "buffer sync write failed during post-cleaning of recovery.");
750 brelse(bh);
751}
752
753/**
754 * nilfs_abort_roll_forward - cleaning up after a failed rollforward recovery
755 * @nilfs: nilfs object
756 */
757static void nilfs_abort_roll_forward(struct the_nilfs *nilfs)
758{
759 struct nilfs_inode_info *ii, *n;
760 LIST_HEAD(head);
761
762 /* Abandon inodes that have read recovery data */
763 spin_lock(lock: &nilfs->ns_inode_lock);
764 list_splice_init(list: &nilfs->ns_dirty_files, head: &head);
765 spin_unlock(lock: &nilfs->ns_inode_lock);
766 if (list_empty(head: &head))
767 return;
768
769 set_nilfs_purging(nilfs);
770 list_for_each_entry_safe(ii, n, &head, i_dirty) {
771 spin_lock(lock: &nilfs->ns_inode_lock);
772 list_del_init(entry: &ii->i_dirty);
773 spin_unlock(lock: &nilfs->ns_inode_lock);
774
775 iput(&ii->vfs_inode);
776 }
777 clear_nilfs_purging(nilfs);
778}
779
780/**
781 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint
782 * @nilfs: nilfs object
783 * @sb: super block instance
784 * @ri: pointer to a nilfs_recovery_info struct to store search results.
785 *
786 * Return: 0 on success, or one of the following negative error codes on
787 * failure:
788 * * %-EINVAL - Inconsistent filesystem state.
789 * * %-EIO - I/O error.
790 * * %-ENOMEM - Insufficient memory available.
791 * * %-ENOSPC - No space left on device (only in a panic state).
792 * * %-ERESTARTSYS - Interrupted.
793 */
794int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs,
795 struct super_block *sb,
796 struct nilfs_recovery_info *ri)
797{
798 struct nilfs_root *root;
799 int err;
800
801 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
802 return 0;
803
804 err = nilfs_attach_checkpoint(sb, cno: ri->ri_cno, curr_mnt: true, root: &root);
805 if (unlikely(err)) {
806 nilfs_err(sb, "error %d loading the latest checkpoint", err);
807 return err;
808 }
809
810 err = nilfs_do_roll_forward(nilfs, sb, root, ri);
811 if (unlikely(err))
812 goto failed;
813
814 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
815 err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri);
816 if (unlikely(err)) {
817 nilfs_err(sb, "error %d preparing segment for recovery",
818 err);
819 goto failed;
820 }
821
822 err = nilfs_attach_log_writer(sb, root);
823 if (unlikely(err))
824 goto failed;
825
826 set_nilfs_discontinued(nilfs);
827 err = nilfs_construct_segment(sb);
828 nilfs_detach_log_writer(sb);
829
830 if (unlikely(err)) {
831 nilfs_err(sb, "error %d writing segment for recovery",
832 err);
833 goto put_root;
834 }
835
836 nilfs_finish_roll_forward(nilfs, ri);
837 }
838
839put_root:
840 nilfs_put_root(root);
841 return err;
842
843failed:
844 nilfs_abort_roll_forward(nilfs);
845 goto put_root;
846}
847
848/**
849 * nilfs_search_super_root - search the latest valid super root
850 * @nilfs: the_nilfs
851 * @ri: pointer to a nilfs_recovery_info struct to store search results.
852 *
853 * nilfs_search_super_root() looks for the latest super-root from a partial
854 * segment pointed by the superblock. It sets up struct the_nilfs through
855 * this search. It fills nilfs_recovery_info (ri) required for recovery.
856 *
857 * Return: 0 on success, or one of the following negative error codes on
858 * failure:
859 * * %-EINVAL - No valid segment found.
860 * * %-EIO - I/O error.
861 * * %-ENOMEM - Insufficient memory available.
862 */
863int nilfs_search_super_root(struct the_nilfs *nilfs,
864 struct nilfs_recovery_info *ri)
865{
866 struct buffer_head *bh_sum = NULL;
867 struct nilfs_segment_summary *sum = NULL;
868 sector_t pseg_start, pseg_end, sr_pseg_start = 0;
869 sector_t seg_start, seg_end; /* range of full segment (block number) */
870 sector_t b, end;
871 unsigned long nblocks;
872 unsigned int flags;
873 u64 seg_seq;
874 __u64 segnum, nextnum = 0;
875 __u64 cno;
876 LIST_HEAD(segments);
877 int empty_seg = 0, scan_newer = 0;
878 int ret;
879
880 pseg_start = nilfs->ns_last_pseg;
881 seg_seq = nilfs->ns_last_seq;
882 cno = nilfs->ns_last_cno;
883 segnum = nilfs_get_segnum_of_block(nilfs, blocknr: pseg_start);
884
885 /* Calculate range of segment */
886 nilfs_get_segment_range(nilfs, segnum, seg_start: &seg_start, seg_end: &seg_end);
887
888 /* Read ahead segment */
889 b = seg_start;
890 while (b <= seg_end)
891 __breadahead(nilfs->ns_bdev, block: b++, size: nilfs->ns_blocksize);
892
893 for (;;) {
894 brelse(bh: bh_sum);
895 ret = NILFS_SEG_FAIL_IO;
896 bh_sum = nilfs_read_log_header(nilfs, start_blocknr: pseg_start, sum: &sum);
897 if (!bh_sum)
898 goto failed;
899
900 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
901 if (ret) {
902 if (ret == NILFS_SEG_FAIL_IO)
903 goto failed;
904 goto strayed;
905 }
906
907 nblocks = le32_to_cpu(sum->ss_nblocks);
908 pseg_end = pseg_start + nblocks - 1;
909 if (unlikely(pseg_end > seg_end)) {
910 ret = NILFS_SEG_FAIL_CONSISTENCY;
911 goto strayed;
912 }
913
914 /* A valid partial segment */
915 ri->ri_pseg_start = pseg_start;
916 ri->ri_seq = seg_seq;
917 ri->ri_segnum = segnum;
918 nextnum = nilfs_get_segnum_of_block(nilfs,
919 le64_to_cpu(sum->ss_next));
920 ri->ri_nextnum = nextnum;
921 empty_seg = 0;
922
923 flags = le16_to_cpu(sum->ss_flags);
924 if (!(flags & NILFS_SS_SR) && !scan_newer) {
925 /*
926 * This will never happen because a superblock
927 * (last_segment) always points to a pseg with
928 * a super root.
929 */
930 ret = NILFS_SEG_FAIL_CONSISTENCY;
931 goto failed;
932 }
933
934 if (pseg_start == seg_start) {
935 nilfs_get_segment_range(nilfs, segnum: nextnum, seg_start: &b, seg_end: &end);
936 while (b <= end)
937 __breadahead(nilfs->ns_bdev, block: b++,
938 size: nilfs->ns_blocksize);
939 }
940 if (!(flags & NILFS_SS_SR)) {
941 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) {
942 ri->ri_lsegs_start = pseg_start;
943 ri->ri_lsegs_start_seq = seg_seq;
944 }
945 if (flags & NILFS_SS_LOGEND)
946 ri->ri_lsegs_end = pseg_start;
947 goto try_next_pseg;
948 }
949
950 /* A valid super root was found. */
951 ri->ri_cno = cno++;
952 ri->ri_super_root = pseg_end;
953 ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
954
955 nilfs_dispose_segment_list(head: &segments);
956 sr_pseg_start = pseg_start;
957 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start;
958 nilfs->ns_seg_seq = seg_seq;
959 nilfs->ns_segnum = segnum;
960 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
961 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
962 nilfs->ns_nextnum = nextnum;
963
964 if (scan_newer)
965 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
966 else {
967 if (nilfs->ns_mount_state & NILFS_VALID_FS)
968 goto super_root_found;
969 scan_newer = 1;
970 }
971
972 try_next_pseg:
973 /* Standing on a course, or met an inconsistent state */
974 pseg_start += nblocks;
975 if (pseg_start < seg_end)
976 continue;
977 goto feed_segment;
978
979 strayed:
980 /* Off the trail */
981 if (!scan_newer)
982 /*
983 * This can happen if a checkpoint was written without
984 * barriers, or as a result of an I/O failure.
985 */
986 goto failed;
987
988 feed_segment:
989 /* Looking to the next full segment */
990 if (empty_seg++)
991 goto super_root_found; /* found a valid super root */
992
993 ret = nilfs_segment_list_add(head: &segments, segnum);
994 if (unlikely(ret))
995 goto failed;
996
997 seg_seq++;
998 segnum = nextnum;
999 nilfs_get_segment_range(nilfs, segnum, seg_start: &seg_start, seg_end: &seg_end);
1000 pseg_start = seg_start;
1001 }
1002
1003 super_root_found:
1004 /* Updating pointers relating to the latest checkpoint */
1005 brelse(bh: bh_sum);
1006 list_splice_tail(list: &segments, head: &ri->ri_used_segments);
1007 nilfs->ns_last_pseg = sr_pseg_start;
1008 nilfs->ns_last_seq = nilfs->ns_seg_seq;
1009 nilfs->ns_last_cno = ri->ri_cno;
1010 return 0;
1011
1012 failed:
1013 brelse(bh: bh_sum);
1014 nilfs_dispose_segment_list(head: &segments);
1015 return ret < 0 ? ret : nilfs_warn_segment_error(sb: nilfs->ns_sb, err: ret);
1016}
1017

source code of linux/fs/nilfs2/recovery.c