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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 * Written by Ryusuke Konishi.
17 */
18
19#include <linux/buffer_head.h>
20#include <linux/blkdev.h>
21#include <linux/swap.h>
22#include <linux/slab.h>
23#include <linux/crc32.h>
24#include "nilfs.h"
25#include "segment.h"
26#include "sufile.h"
27#include "page.h"
28#include "segbuf.h"
29
30/*
31 * Segment check result
32 */
33enum {
34 NILFS_SEG_VALID,
35 NILFS_SEG_NO_SUPER_ROOT,
36 NILFS_SEG_FAIL_IO,
37 NILFS_SEG_FAIL_MAGIC,
38 NILFS_SEG_FAIL_SEQ,
39 NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT,
40 NILFS_SEG_FAIL_CHECKSUM_FULL,
41 NILFS_SEG_FAIL_CONSISTENCY,
42};
43
44/* work structure for recovery */
45struct nilfs_recovery_block {
46 ino_t ino; /*
47 * Inode number of the file that this block
48 * belongs to
49 */
50 sector_t blocknr; /* block number */
51 __u64 vblocknr; /* virtual block number */
52 unsigned long blkoff; /* File offset of the data block (per block) */
53 struct list_head list;
54};
55
56
57static int nilfs_warn_segment_error(struct super_block *sb, int err)
58{
59 const char *msg = NULL;
60
61 switch (err) {
62 case NILFS_SEG_FAIL_IO:
63 nilfs_msg(sb, KERN_ERR, "I/O error reading segment");
64 return -EIO;
65 case NILFS_SEG_FAIL_MAGIC:
66 msg = "Magic number mismatch";
67 break;
68 case NILFS_SEG_FAIL_SEQ:
69 msg = "Sequence number mismatch";
70 break;
71 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT:
72 msg = "Checksum error in super root";
73 break;
74 case NILFS_SEG_FAIL_CHECKSUM_FULL:
75 msg = "Checksum error in segment payload";
76 break;
77 case NILFS_SEG_FAIL_CONSISTENCY:
78 msg = "Inconsistency found";
79 break;
80 case NILFS_SEG_NO_SUPER_ROOT:
81 msg = "No super root in the last segment";
82 break;
83 default:
84 nilfs_msg(sb, KERN_ERR, "unrecognized segment error %d", err);
85 return -EINVAL;
86 }
87 nilfs_msg(sb, KERN_WARNING, "invalid segment: %s", msg);
88 return -EINVAL;
89}
90
91/**
92 * nilfs_compute_checksum - compute checksum of blocks continuously
93 * @nilfs: nilfs object
94 * @bhs: buffer head of start block
95 * @sum: place to store result
96 * @offset: offset bytes in the first block
97 * @check_bytes: number of bytes to be checked
98 * @start: DBN of start block
99 * @nblock: number of blocks to be checked
100 */
101static int nilfs_compute_checksum(struct the_nilfs *nilfs,
102 struct buffer_head *bhs, u32 *sum,
103 unsigned long offset, u64 check_bytes,
104 sector_t start, unsigned long nblock)
105{
106 unsigned int blocksize = nilfs->ns_blocksize;
107 unsigned long size;
108 u32 crc;
109
110 BUG_ON(offset >= blocksize);
111 check_bytes -= offset;
112 size = min_t(u64, check_bytes, blocksize - offset);
113 crc = crc32_le(nilfs->ns_crc_seed,
114 (unsigned char *)bhs->b_data + offset, size);
115 if (--nblock > 0) {
116 do {
117 struct buffer_head *bh;
118
119 bh = __bread(nilfs->ns_bdev, ++start, blocksize);
120 if (!bh)
121 return -EIO;
122 check_bytes -= size;
123 size = min_t(u64, check_bytes, blocksize);
124 crc = crc32_le(crc, bh->b_data, size);
125 brelse(bh);
126 } while (--nblock > 0);
127 }
128 *sum = crc;
129 return 0;
130}
131
132/**
133 * nilfs_read_super_root_block - read super root block
134 * @nilfs: nilfs object
135 * @sr_block: disk block number of the super root block
136 * @pbh: address of a buffer_head pointer to return super root buffer
137 * @check: CRC check flag
138 */
139int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
140 struct buffer_head **pbh, int check)
141{
142 struct buffer_head *bh_sr;
143 struct nilfs_super_root *sr;
144 u32 crc;
145 int ret;
146
147 *pbh = NULL;
148 bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize);
149 if (unlikely(!bh_sr)) {
150 ret = NILFS_SEG_FAIL_IO;
151 goto failed;
152 }
153
154 sr = (struct nilfs_super_root *)bh_sr->b_data;
155 if (check) {
156 unsigned int bytes = le16_to_cpu(sr->sr_bytes);
157
158 if (bytes == 0 || bytes > nilfs->ns_blocksize) {
159 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
160 goto failed_bh;
161 }
162 if (nilfs_compute_checksum(
163 nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes,
164 sr_block, 1)) {
165 ret = NILFS_SEG_FAIL_IO;
166 goto failed_bh;
167 }
168 if (crc != le32_to_cpu(sr->sr_sum)) {
169 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
170 goto failed_bh;
171 }
172 }
173 *pbh = bh_sr;
174 return 0;
175
176 failed_bh:
177 brelse(bh_sr);
178
179 failed:
180 return nilfs_warn_segment_error(nilfs->ns_sb, ret);
181}
182
183/**
184 * nilfs_read_log_header - read summary header of the specified log
185 * @nilfs: nilfs object
186 * @start_blocknr: start block number of the log
187 * @sum: pointer to return segment summary structure
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(nilfs->ns_bdev, start_blocknr, 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 */
208static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
209 struct buffer_head *bh_sum,
210 struct nilfs_segment_summary *sum)
211{
212 unsigned long nblock;
213 u32 crc;
214 int ret;
215
216 ret = NILFS_SEG_FAIL_MAGIC;
217 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC)
218 goto out;
219
220 ret = NILFS_SEG_FAIL_SEQ;
221 if (le64_to_cpu(sum->ss_seq) != seg_seq)
222 goto out;
223
224 nblock = le32_to_cpu(sum->ss_nblocks);
225 ret = NILFS_SEG_FAIL_CONSISTENCY;
226 if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment))
227 /* This limits the number of blocks read in the CRC check */
228 goto out;
229
230 ret = NILFS_SEG_FAIL_IO;
231 if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum),
232 ((u64)nblock << nilfs->ns_blocksize_bits),
233 bh_sum->b_blocknr, nblock))
234 goto out;
235
236 ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
237 if (crc != le32_to_cpu(sum->ss_datasum))
238 goto out;
239 ret = 0;
240out:
241 return ret;
242}
243
244/**
245 * nilfs_read_summary_info - read an item on summary blocks of a log
246 * @nilfs: nilfs object
247 * @pbh: the current buffer head on summary blocks [in, out]
248 * @offset: the current byte offset on summary blocks [in, out]
249 * @bytes: byte size of the item to be read
250 */
251static void *nilfs_read_summary_info(struct the_nilfs *nilfs,
252 struct buffer_head **pbh,
253 unsigned int *offset, unsigned int bytes)
254{
255 void *ptr;
256 sector_t blocknr;
257
258 BUG_ON((*pbh)->b_size < *offset);
259 if (bytes > (*pbh)->b_size - *offset) {
260 blocknr = (*pbh)->b_blocknr;
261 brelse(*pbh);
262 *pbh = __bread(nilfs->ns_bdev, blocknr + 1,
263 nilfs->ns_blocksize);
264 if (unlikely(!*pbh))
265 return NULL;
266 *offset = 0;
267 }
268 ptr = (*pbh)->b_data + *offset;
269 *offset += bytes;
270 return ptr;
271}
272
273/**
274 * nilfs_skip_summary_info - skip items on summary blocks of a log
275 * @nilfs: nilfs object
276 * @pbh: the current buffer head on summary blocks [in, out]
277 * @offset: the current byte offset on summary blocks [in, out]
278 * @bytes: byte size of the item to be skipped
279 * @count: number of items to be skipped
280 */
281static void nilfs_skip_summary_info(struct the_nilfs *nilfs,
282 struct buffer_head **pbh,
283 unsigned int *offset, unsigned int bytes,
284 unsigned long count)
285{
286 unsigned int rest_item_in_current_block
287 = ((*pbh)->b_size - *offset) / bytes;
288
289 if (count <= rest_item_in_current_block) {
290 *offset += bytes * count;
291 } else {
292 sector_t blocknr = (*pbh)->b_blocknr;
293 unsigned int nitem_per_block = (*pbh)->b_size / bytes;
294 unsigned int bcnt;
295
296 count -= rest_item_in_current_block;
297 bcnt = DIV_ROUND_UP(count, nitem_per_block);
298 *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
299
300 brelse(*pbh);
301 *pbh = __bread(nilfs->ns_bdev, blocknr + bcnt,
302 nilfs->ns_blocksize);
303 }
304}
305
306/**
307 * nilfs_scan_dsync_log - get block information of a log written for data sync
308 * @nilfs: nilfs object
309 * @start_blocknr: start block number of the log
310 * @sum: log summary information
311 * @head: list head to add nilfs_recovery_block struct
312 */
313static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr,
314 struct nilfs_segment_summary *sum,
315 struct list_head *head)
316{
317 struct buffer_head *bh;
318 unsigned int offset;
319 u32 nfinfo, sumbytes;
320 sector_t blocknr;
321 ino_t ino;
322 int err = -EIO;
323
324 nfinfo = le32_to_cpu(sum->ss_nfinfo);
325 if (!nfinfo)
326 return 0;
327
328 sumbytes = le32_to_cpu(sum->ss_sumbytes);
329 blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize);
330 bh = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize);
331 if (unlikely(!bh))
332 goto out;
333
334 offset = le16_to_cpu(sum->ss_bytes);
335 for (;;) {
336 unsigned long nblocks, ndatablk, nnodeblk;
337 struct nilfs_finfo *finfo;
338
339 finfo = nilfs_read_summary_info(nilfs, &bh, &offset,
340 sizeof(*finfo));
341 if (unlikely(!finfo))
342 goto out;
343
344 ino = le64_to_cpu(finfo->fi_ino);
345 nblocks = le32_to_cpu(finfo->fi_nblocks);
346 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
347 nnodeblk = nblocks - ndatablk;
348
349 while (ndatablk-- > 0) {
350 struct nilfs_recovery_block *rb;
351 struct nilfs_binfo_v *binfo;
352
353 binfo = nilfs_read_summary_info(nilfs, &bh, &offset,
354 sizeof(*binfo));
355 if (unlikely(!binfo))
356 goto out;
357
358 rb = kmalloc(sizeof(*rb), GFP_NOFS);
359 if (unlikely(!rb)) {
360 err = -ENOMEM;
361 goto out;
362 }
363 rb->ino = ino;
364 rb->blocknr = blocknr++;
365 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr);
366 rb->blkoff = le64_to_cpu(binfo->bi_blkoff);
367 /* INIT_LIST_HEAD(&rb->list); */
368 list_add_tail(&rb->list, head);
369 }
370 if (--nfinfo == 0)
371 break;
372 blocknr += nnodeblk; /* always 0 for data sync logs */
373 nilfs_skip_summary_info(nilfs, &bh, &offset, sizeof(__le64),
374 nnodeblk);
375 if (unlikely(!bh))
376 goto out;
377 }
378 err = 0;
379 out:
380 brelse(bh); /* brelse(NULL) is just ignored */
381 return err;
382}
383
384static void dispose_recovery_list(struct list_head *head)
385{
386 while (!list_empty(head)) {
387 struct nilfs_recovery_block *rb;
388
389 rb = list_first_entry(head, struct nilfs_recovery_block, list);
390 list_del(&rb->list);
391 kfree(rb);
392 }
393}
394
395struct nilfs_segment_entry {
396 struct list_head list;
397 __u64 segnum;
398};
399
400static int nilfs_segment_list_add(struct list_head *head, __u64 segnum)
401{
402 struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS);
403
404 if (unlikely(!ent))
405 return -ENOMEM;
406
407 ent->segnum = segnum;
408 INIT_LIST_HEAD(&ent->list);
409 list_add_tail(&ent->list, head);
410 return 0;
411}
412
413void nilfs_dispose_segment_list(struct list_head *head)
414{
415 while (!list_empty(head)) {
416 struct nilfs_segment_entry *ent;
417
418 ent = list_first_entry(head, struct nilfs_segment_entry, list);
419 list_del(&ent->list);
420 kfree(ent);
421 }
422}
423
424static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
425 struct super_block *sb,
426 struct nilfs_recovery_info *ri)
427{
428 struct list_head *head = &ri->ri_used_segments;
429 struct nilfs_segment_entry *ent, *n;
430 struct inode *sufile = nilfs->ns_sufile;
431 __u64 segnum[4];
432 int err;
433 int i;
434
435 segnum[0] = nilfs->ns_segnum;
436 segnum[1] = nilfs->ns_nextnum;
437 segnum[2] = ri->ri_segnum;
438 segnum[3] = ri->ri_nextnum;
439
440 /*
441 * Releasing the next segment of the latest super root.
442 * The next segment is invalidated by this recovery.
443 */
444 err = nilfs_sufile_free(sufile, segnum[1]);
445 if (unlikely(err))
446 goto failed;
447
448 for (i = 1; i < 4; i++) {
449 err = nilfs_segment_list_add(head, segnum[i]);
450 if (unlikely(err))
451 goto failed;
452 }
453
454 /*
455 * Collecting segments written after the latest super root.
456 * These are marked dirty to avoid being reallocated in the next write.
457 */
458 list_for_each_entry_safe(ent, n, head, list) {
459 if (ent->segnum != segnum[0]) {
460 err = nilfs_sufile_scrap(sufile, ent->segnum);
461 if (unlikely(err))
462 goto failed;
463 }
464 list_del(&ent->list);
465 kfree(ent);
466 }
467
468 /* Allocate new segments for recovery */
469 err = nilfs_sufile_alloc(sufile, &segnum[0]);
470 if (unlikely(err))
471 goto failed;
472
473 nilfs->ns_pseg_offset = 0;
474 nilfs->ns_seg_seq = ri->ri_seq + 2;
475 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
476
477 failed:
478 /* No need to recover sufile because it will be destroyed on error */
479 return err;
480}
481
482static int nilfs_recovery_copy_block(struct the_nilfs *nilfs,
483 struct nilfs_recovery_block *rb,
484 struct page *page)
485{
486 struct buffer_head *bh_org;
487 void *kaddr;
488
489 bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize);
490 if (unlikely(!bh_org))
491 return -EIO;
492
493 kaddr = kmap_atomic(page);
494 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
495 kunmap_atomic(kaddr);
496 brelse(bh_org);
497 return 0;
498}
499
500static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs,
501 struct super_block *sb,
502 struct nilfs_root *root,
503 struct list_head *head,
504 unsigned long *nr_salvaged_blocks)
505{
506 struct inode *inode;
507 struct nilfs_recovery_block *rb, *n;
508 unsigned int blocksize = nilfs->ns_blocksize;
509 struct page *page;
510 loff_t pos;
511 int err = 0, err2 = 0;
512
513 list_for_each_entry_safe(rb, n, head, list) {
514 inode = nilfs_iget(sb, root, rb->ino);
515 if (IS_ERR(inode)) {
516 err = PTR_ERR(inode);
517 inode = NULL;
518 goto failed_inode;
519 }
520
521 pos = rb->blkoff << inode->i_blkbits;
522 err = block_write_begin(inode->i_mapping, pos, blocksize,
523 0, &page, nilfs_get_block);
524 if (unlikely(err)) {
525 loff_t isize = inode->i_size;
526
527 if (pos + blocksize > isize)
528 nilfs_write_failed(inode->i_mapping,
529 pos + blocksize);
530 goto failed_inode;
531 }
532
533 err = nilfs_recovery_copy_block(nilfs, rb, page);
534 if (unlikely(err))
535 goto failed_page;
536
537 err = nilfs_set_file_dirty(inode, 1);
538 if (unlikely(err))
539 goto failed_page;
540
541 block_write_end(NULL, inode->i_mapping, pos, blocksize,
542 blocksize, page, NULL);
543
544 unlock_page(page);
545 put_page(page);
546
547 (*nr_salvaged_blocks)++;
548 goto next;
549
550 failed_page:
551 unlock_page(page);
552 put_page(page);
553
554 failed_inode:
555 nilfs_msg(sb, KERN_WARNING,
556 "error %d recovering data block (ino=%lu, block-offset=%llu)",
557 err, (unsigned long)rb->ino,
558 (unsigned long long)rb->blkoff);
559 if (!err2)
560 err2 = err;
561 next:
562 iput(inode); /* iput(NULL) is just ignored */
563 list_del_init(&rb->list);
564 kfree(rb);
565 }
566 return err2;
567}
568
569/**
570 * nilfs_do_roll_forward - salvage logical segments newer than the latest
571 * checkpoint
572 * @nilfs: nilfs object
573 * @sb: super block instance
574 * @ri: pointer to a nilfs_recovery_info
575 */
576static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
577 struct super_block *sb,
578 struct nilfs_root *root,
579 struct nilfs_recovery_info *ri)
580{
581 struct buffer_head *bh_sum = NULL;
582 struct nilfs_segment_summary *sum = NULL;
583 sector_t pseg_start;
584 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
585 unsigned long nsalvaged_blocks = 0;
586 unsigned int flags;
587 u64 seg_seq;
588 __u64 segnum, nextnum = 0;
589 int empty_seg = 0;
590 int err = 0, ret;
591 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
592 enum {
593 RF_INIT_ST,
594 RF_DSYNC_ST, /* scanning data-sync segments */
595 };
596 int state = RF_INIT_ST;
597
598 pseg_start = ri->ri_lsegs_start;
599 seg_seq = ri->ri_lsegs_start_seq;
600 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
601 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
602
603 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
604 brelse(bh_sum);
605 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
606 if (!bh_sum) {
607 err = -EIO;
608 goto failed;
609 }
610
611 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
612 if (ret) {
613 if (ret == NILFS_SEG_FAIL_IO) {
614 err = -EIO;
615 goto failed;
616 }
617 goto strayed;
618 }
619
620 flags = le16_to_cpu(sum->ss_flags);
621 if (flags & NILFS_SS_SR)
622 goto confused;
623
624 /* Found a valid partial segment; do recovery actions */
625 nextnum = nilfs_get_segnum_of_block(nilfs,
626 le64_to_cpu(sum->ss_next));
627 empty_seg = 0;
628 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
629 if (!(flags & NILFS_SS_GC))
630 nilfs->ns_nongc_ctime = nilfs->ns_ctime;
631
632 switch (state) {
633 case RF_INIT_ST:
634 if (!(flags & NILFS_SS_LOGBGN) ||
635 !(flags & NILFS_SS_SYNDT))
636 goto try_next_pseg;
637 state = RF_DSYNC_ST;
638 /* Fall through */
639 case RF_DSYNC_ST:
640 if (!(flags & NILFS_SS_SYNDT))
641 goto confused;
642
643 err = nilfs_scan_dsync_log(nilfs, pseg_start, sum,
644 &dsync_blocks);
645 if (unlikely(err))
646 goto failed;
647 if (flags & NILFS_SS_LOGEND) {
648 err = nilfs_recover_dsync_blocks(
649 nilfs, sb, root, &dsync_blocks,
650 &nsalvaged_blocks);
651 if (unlikely(err))
652 goto failed;
653 state = RF_INIT_ST;
654 }
655 break; /* Fall through to try_next_pseg */
656 }
657
658 try_next_pseg:
659 if (pseg_start == ri->ri_lsegs_end)
660 break;
661 pseg_start += le32_to_cpu(sum->ss_nblocks);
662 if (pseg_start < seg_end)
663 continue;
664 goto feed_segment;
665
666 strayed:
667 if (pseg_start == ri->ri_lsegs_end)
668 break;
669
670 feed_segment:
671 /* Looking to the next full segment */
672 if (empty_seg++)
673 break;
674 seg_seq++;
675 segnum = nextnum;
676 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
677 pseg_start = seg_start;
678 }
679
680 if (nsalvaged_blocks) {
681 nilfs_msg(sb, KERN_INFO, "salvaged %lu blocks",
682 nsalvaged_blocks);
683 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
684 }
685 out:
686 brelse(bh_sum);
687 dispose_recovery_list(&dsync_blocks);
688 return err;
689
690 confused:
691 err = -EINVAL;
692 failed:
693 nilfs_msg(sb, KERN_ERR,
694 "error %d roll-forwarding partial segment at blocknr = %llu",
695 err, (unsigned long long)pseg_start);
696 goto out;
697}
698
699static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
700 struct nilfs_recovery_info *ri)
701{
702 struct buffer_head *bh;
703 int err;
704
705 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) !=
706 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root))
707 return;
708
709 bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize);
710 BUG_ON(!bh);
711 memset(bh->b_data, 0, bh->b_size);
712 set_buffer_dirty(bh);
713 err = sync_dirty_buffer(bh);
714 if (unlikely(err))
715 nilfs_msg(nilfs->ns_sb, KERN_WARNING,
716 "buffer sync write failed during post-cleaning of recovery.");
717 brelse(bh);
718}
719
720/**
721 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint
722 * @nilfs: nilfs object
723 * @sb: super block instance
724 * @ri: pointer to a nilfs_recovery_info struct to store search results.
725 *
726 * Return Value: On success, 0 is returned. On error, one of the following
727 * negative error code is returned.
728 *
729 * %-EINVAL - Inconsistent filesystem state.
730 *
731 * %-EIO - I/O error
732 *
733 * %-ENOSPC - No space left on device (only in a panic state).
734 *
735 * %-ERESTARTSYS - Interrupted.
736 *
737 * %-ENOMEM - Insufficient memory available.
738 */
739int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs,
740 struct super_block *sb,
741 struct nilfs_recovery_info *ri)
742{
743 struct nilfs_root *root;
744 int err;
745
746 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
747 return 0;
748
749 err = nilfs_attach_checkpoint(sb, ri->ri_cno, true, &root);
750 if (unlikely(err)) {
751 nilfs_msg(sb, KERN_ERR,
752 "error %d loading the latest checkpoint", err);
753 return err;
754 }
755
756 err = nilfs_do_roll_forward(nilfs, sb, root, ri);
757 if (unlikely(err))
758 goto failed;
759
760 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
761 err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri);
762 if (unlikely(err)) {
763 nilfs_msg(sb, KERN_ERR,
764 "error %d preparing segment for recovery",
765 err);
766 goto failed;
767 }
768
769 err = nilfs_attach_log_writer(sb, root);
770 if (unlikely(err))
771 goto failed;
772
773 set_nilfs_discontinued(nilfs);
774 err = nilfs_construct_segment(sb);
775 nilfs_detach_log_writer(sb);
776
777 if (unlikely(err)) {
778 nilfs_msg(sb, KERN_ERR,
779 "error %d writing segment for recovery",
780 err);
781 goto failed;
782 }
783
784 nilfs_finish_roll_forward(nilfs, ri);
785 }
786
787 failed:
788 nilfs_put_root(root);
789 return err;
790}
791
792/**
793 * nilfs_search_super_root - search the latest valid super root
794 * @nilfs: the_nilfs
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 *
808 * %-ENOMEM - Insufficient memory available.
809 */
810int nilfs_search_super_root(struct the_nilfs *nilfs,
811 struct nilfs_recovery_info *ri)
812{
813 struct buffer_head *bh_sum = NULL;
814 struct nilfs_segment_summary *sum = NULL;
815 sector_t pseg_start, pseg_end, sr_pseg_start = 0;
816 sector_t seg_start, seg_end; /* range of full segment (block number) */
817 sector_t b, end;
818 unsigned long nblocks;
819 unsigned int flags;
820 u64 seg_seq;
821 __u64 segnum, nextnum = 0;
822 __u64 cno;
823 LIST_HEAD(segments);
824 int empty_seg = 0, scan_newer = 0;
825 int ret;
826
827 pseg_start = nilfs->ns_last_pseg;
828 seg_seq = nilfs->ns_last_seq;
829 cno = nilfs->ns_last_cno;
830 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
831
832 /* Calculate range of segment */
833 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
834
835 /* Read ahead segment */
836 b = seg_start;
837 while (b <= seg_end)
838 __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize);
839
840 for (;;) {
841 brelse(bh_sum);
842 ret = NILFS_SEG_FAIL_IO;
843 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
844 if (!bh_sum)
845 goto failed;
846
847 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
848 if (ret) {
849 if (ret == NILFS_SEG_FAIL_IO)
850 goto failed;
851 goto strayed;
852 }
853
854 nblocks = le32_to_cpu(sum->ss_nblocks);
855 pseg_end = pseg_start + nblocks - 1;
856 if (unlikely(pseg_end > seg_end)) {
857 ret = NILFS_SEG_FAIL_CONSISTENCY;
858 goto strayed;
859 }
860
861 /* A valid partial segment */
862 ri->ri_pseg_start = pseg_start;
863 ri->ri_seq = seg_seq;
864 ri->ri_segnum = segnum;
865 nextnum = nilfs_get_segnum_of_block(nilfs,
866 le64_to_cpu(sum->ss_next));
867 ri->ri_nextnum = nextnum;
868 empty_seg = 0;
869
870 flags = le16_to_cpu(sum->ss_flags);
871 if (!(flags & NILFS_SS_SR) && !scan_newer) {
872 /*
873 * This will never happen because a superblock
874 * (last_segment) always points to a pseg with
875 * a super root.
876 */
877 ret = NILFS_SEG_FAIL_CONSISTENCY;
878 goto failed;
879 }
880
881 if (pseg_start == seg_start) {
882 nilfs_get_segment_range(nilfs, nextnum, &b, &end);
883 while (b <= end)
884 __breadahead(nilfs->ns_bdev, b++,
885 nilfs->ns_blocksize);
886 }
887 if (!(flags & NILFS_SS_SR)) {
888 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) {
889 ri->ri_lsegs_start = pseg_start;
890 ri->ri_lsegs_start_seq = seg_seq;
891 }
892 if (flags & NILFS_SS_LOGEND)
893 ri->ri_lsegs_end = pseg_start;
894 goto try_next_pseg;
895 }
896
897 /* A valid super root was found. */
898 ri->ri_cno = cno++;
899 ri->ri_super_root = pseg_end;
900 ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
901
902 nilfs_dispose_segment_list(&segments);
903 sr_pseg_start = pseg_start;
904 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start;
905 nilfs->ns_seg_seq = seg_seq;
906 nilfs->ns_segnum = segnum;
907 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
908 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
909 nilfs->ns_nextnum = nextnum;
910
911 if (scan_newer)
912 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
913 else {
914 if (nilfs->ns_mount_state & NILFS_VALID_FS)
915 goto super_root_found;
916 scan_newer = 1;
917 }
918
919 try_next_pseg:
920 /* Standing on a course, or met an inconsistent state */
921 pseg_start += nblocks;
922 if (pseg_start < seg_end)
923 continue;
924 goto feed_segment;
925
926 strayed:
927 /* Off the trail */
928 if (!scan_newer)
929 /*
930 * This can happen if a checkpoint was written without
931 * barriers, or as a result of an I/O failure.
932 */
933 goto failed;
934
935 feed_segment:
936 /* Looking to the next full segment */
937 if (empty_seg++)
938 goto super_root_found; /* found a valid super root */
939
940 ret = nilfs_segment_list_add(&segments, segnum);
941 if (unlikely(ret))
942 goto failed;
943
944 seg_seq++;
945 segnum = nextnum;
946 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
947 pseg_start = seg_start;
948 }
949
950 super_root_found:
951 /* Updating pointers relating to the latest checkpoint */
952 brelse(bh_sum);
953 list_splice_tail(&segments, &ri->ri_used_segments);
954 nilfs->ns_last_pseg = sr_pseg_start;
955 nilfs->ns_last_seq = nilfs->ns_seg_seq;
956 nilfs->ns_last_cno = ri->ri_cno;
957 return 0;
958
959 failed:
960 brelse(bh_sum);
961 nilfs_dispose_segment_list(&segments);
962 return ret < 0 ? ret : nilfs_warn_segment_error(nilfs->ns_sb, ret);
963}
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/slab.h>
27#include <linux/crc32.h>
28#include "nilfs.h"
29#include "segment.h"
30#include "sufile.h"
31#include "page.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_SUPER_ROOT,
44 NILFS_SEG_FAIL_CHECKSUM_FULL,
45 NILFS_SEG_FAIL_CONSISTENCY,
46};
47
48/* work structure for recovery */
49struct nilfs_recovery_block {
50 ino_t ino; /* Inode number of the file that this block
51 belongs to */
52 sector_t blocknr; /* block number */
53 __u64 vblocknr; /* virtual block number */
54 unsigned long blkoff; /* File offset of the data block (per block) */
55 struct list_head list;
56};
57
58
59static int nilfs_warn_segment_error(int err)
60{
61 switch (err) {
62 case NILFS_SEG_FAIL_IO:
63 printk(KERN_WARNING
64 "NILFS warning: I/O error on loading last segment\n");
65 return -EIO;
66 case NILFS_SEG_FAIL_MAGIC:
67 printk(KERN_WARNING
68 "NILFS warning: Segment magic number invalid\n");
69 break;
70 case NILFS_SEG_FAIL_SEQ:
71 printk(KERN_WARNING
72 "NILFS warning: Sequence number mismatch\n");
73 break;
74 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT:
75 printk(KERN_WARNING
76 "NILFS warning: Checksum error in super root\n");
77 break;
78 case NILFS_SEG_FAIL_CHECKSUM_FULL:
79 printk(KERN_WARNING
80 "NILFS warning: Checksum error in segment payload\n");
81 break;
82 case NILFS_SEG_FAIL_CONSISTENCY:
83 printk(KERN_WARNING
84 "NILFS warning: Inconsistent segment\n");
85 break;
86 case NILFS_SEG_NO_SUPER_ROOT:
87 printk(KERN_WARNING
88 "NILFS warning: No super root in the last segment\n");
89 break;
90 }
91 return -EINVAL;
92}
93
94/**
95 * nilfs_compute_checksum - compute checksum of blocks continuously
96 * @nilfs: nilfs object
97 * @bhs: buffer head of start block
98 * @sum: place to store result
99 * @offset: offset bytes in the first block
100 * @check_bytes: number of bytes to be checked
101 * @start: DBN of start block
102 * @nblock: number of blocks to be checked
103 */
104static int nilfs_compute_checksum(struct the_nilfs *nilfs,
105 struct buffer_head *bhs, u32 *sum,
106 unsigned long offset, u64 check_bytes,
107 sector_t start, unsigned long nblock)
108{
109 unsigned int blocksize = nilfs->ns_blocksize;
110 unsigned long size;
111 u32 crc;
112
113 BUG_ON(offset >= blocksize);
114 check_bytes -= offset;
115 size = min_t(u64, check_bytes, blocksize - offset);
116 crc = crc32_le(nilfs->ns_crc_seed,
117 (unsigned char *)bhs->b_data + offset, size);
118 if (--nblock > 0) {
119 do {
120 struct buffer_head *bh;
121
122 bh = __bread(nilfs->ns_bdev, ++start, blocksize);
123 if (!bh)
124 return -EIO;
125 check_bytes -= size;
126 size = min_t(u64, check_bytes, blocksize);
127 crc = crc32_le(crc, bh->b_data, size);
128 brelse(bh);
129 } while (--nblock > 0);
130 }
131 *sum = crc;
132 return 0;
133}
134
135/**
136 * nilfs_read_super_root_block - read super root block
137 * @nilfs: nilfs object
138 * @sr_block: disk block number of the super root block
139 * @pbh: address of a buffer_head pointer to return super root buffer
140 * @check: CRC check flag
141 */
142int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
143 struct buffer_head **pbh, int check)
144{
145 struct buffer_head *bh_sr;
146 struct nilfs_super_root *sr;
147 u32 crc;
148 int ret;
149
150 *pbh = NULL;
151 bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize);
152 if (unlikely(!bh_sr)) {
153 ret = NILFS_SEG_FAIL_IO;
154 goto failed;
155 }
156
157 sr = (struct nilfs_super_root *)bh_sr->b_data;
158 if (check) {
159 unsigned bytes = le16_to_cpu(sr->sr_bytes);
160
161 if (bytes == 0 || bytes > nilfs->ns_blocksize) {
162 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
163 goto failed_bh;
164 }
165 if (nilfs_compute_checksum(
166 nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes,
167 sr_block, 1)) {
168 ret = NILFS_SEG_FAIL_IO;
169 goto failed_bh;
170 }
171 if (crc != le32_to_cpu(sr->sr_sum)) {
172 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
173 goto failed_bh;
174 }
175 }
176 *pbh = bh_sr;
177 return 0;
178
179 failed_bh:
180 brelse(bh_sr);
181
182 failed:
183 return nilfs_warn_segment_error(ret);
184}
185
186/**
187 * nilfs_read_log_header - read summary header of the specified log
188 * @nilfs: nilfs object
189 * @start_blocknr: start block number of the log
190 * @sum: pointer to return segment summary structure
191 */
192static struct buffer_head *
193nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr,
194 struct nilfs_segment_summary **sum)
195{
196 struct buffer_head *bh_sum;
197
198 bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize);
199 if (bh_sum)
200 *sum = (struct nilfs_segment_summary *)bh_sum->b_data;
201 return bh_sum;
202}
203
204/**
205 * nilfs_validate_log - verify consistency of log
206 * @nilfs: nilfs object
207 * @seg_seq: sequence number of segment
208 * @bh_sum: buffer head of summary block
209 * @sum: segment summary struct
210 */
211static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
212 struct buffer_head *bh_sum,
213 struct nilfs_segment_summary *sum)
214{
215 unsigned long nblock;
216 u32 crc;
217 int ret;
218
219 ret = NILFS_SEG_FAIL_MAGIC;
220 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC)
221 goto out;
222
223 ret = NILFS_SEG_FAIL_SEQ;
224 if (le64_to_cpu(sum->ss_seq) != seg_seq)
225 goto out;
226
227 nblock = le32_to_cpu(sum->ss_nblocks);
228 ret = NILFS_SEG_FAIL_CONSISTENCY;
229 if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment))
230 /* This limits the number of blocks read in the CRC check */
231 goto out;
232
233 ret = NILFS_SEG_FAIL_IO;
234 if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum),
235 ((u64)nblock << nilfs->ns_blocksize_bits),
236 bh_sum->b_blocknr, nblock))
237 goto out;
238
239 ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
240 if (crc != le32_to_cpu(sum->ss_datasum))
241 goto out;
242 ret = 0;
243out:
244 return ret;
245}
246
247/**
248 * nilfs_read_summary_info - read an item on summary blocks of a log
249 * @nilfs: nilfs object
250 * @pbh: the current buffer head on summary blocks [in, out]
251 * @offset: the current byte offset on summary blocks [in, out]
252 * @bytes: byte size of the item to be read
253 */
254static void *nilfs_read_summary_info(struct the_nilfs *nilfs,
255 struct buffer_head **pbh,
256 unsigned int *offset, unsigned int bytes)
257{
258 void *ptr;
259 sector_t blocknr;
260
261 BUG_ON((*pbh)->b_size < *offset);
262 if (bytes > (*pbh)->b_size - *offset) {
263 blocknr = (*pbh)->b_blocknr;
264 brelse(*pbh);
265 *pbh = __bread(nilfs->ns_bdev, blocknr + 1,
266 nilfs->ns_blocksize);
267 if (unlikely(!*pbh))
268 return NULL;
269 *offset = 0;
270 }
271 ptr = (*pbh)->b_data + *offset;
272 *offset += bytes;
273 return ptr;
274}
275
276/**
277 * nilfs_skip_summary_info - skip items on summary blocks of a log
278 * @nilfs: nilfs object
279 * @pbh: the current buffer head on summary blocks [in, out]
280 * @offset: the current byte offset on summary blocks [in, out]
281 * @bytes: byte size of the item to be skipped
282 * @count: number of items to be skipped
283 */
284static void nilfs_skip_summary_info(struct the_nilfs *nilfs,
285 struct buffer_head **pbh,
286 unsigned int *offset, unsigned int bytes,
287 unsigned long count)
288{
289 unsigned int rest_item_in_current_block
290 = ((*pbh)->b_size - *offset) / bytes;
291
292 if (count <= rest_item_in_current_block) {
293 *offset += bytes * count;
294 } else {
295 sector_t blocknr = (*pbh)->b_blocknr;
296 unsigned int nitem_per_block = (*pbh)->b_size / bytes;
297 unsigned int bcnt;
298
299 count -= rest_item_in_current_block;
300 bcnt = DIV_ROUND_UP(count, nitem_per_block);
301 *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
302
303 brelse(*pbh);
304 *pbh = __bread(nilfs->ns_bdev, blocknr + bcnt,
305 nilfs->ns_blocksize);
306 }
307}
308
309/**
310 * nilfs_scan_dsync_log - get block information of a log written for data sync
311 * @nilfs: nilfs object
312 * @start_blocknr: start block number of the log
313 * @sum: log summary information
314 * @head: list head to add nilfs_recovery_block struct
315 */
316static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr,
317 struct nilfs_segment_summary *sum,
318 struct list_head *head)
319{
320 struct buffer_head *bh;
321 unsigned int offset;
322 u32 nfinfo, sumbytes;
323 sector_t blocknr;
324 ino_t ino;
325 int err = -EIO;
326
327 nfinfo = le32_to_cpu(sum->ss_nfinfo);
328 if (!nfinfo)
329 return 0;
330
331 sumbytes = le32_to_cpu(sum->ss_sumbytes);
332 blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize);
333 bh = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize);
334 if (unlikely(!bh))
335 goto out;
336
337 offset = le16_to_cpu(sum->ss_bytes);
338 for (;;) {
339 unsigned long nblocks, ndatablk, nnodeblk;
340 struct nilfs_finfo *finfo;
341
342 finfo = nilfs_read_summary_info(nilfs, &bh, &offset,
343 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 = nilfs_read_summary_info(nilfs, &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 data sync logs */
376 nilfs_skip_summary_info(nilfs, &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
392 rb = list_first_entry(head, struct nilfs_recovery_block, list);
393 list_del(&rb->list);
394 kfree(rb);
395 }
396}
397
398struct nilfs_segment_entry {
399 struct list_head list;
400 __u64 segnum;
401};
402
403static int nilfs_segment_list_add(struct list_head *head, __u64 segnum)
404{
405 struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS);
406
407 if (unlikely(!ent))
408 return -ENOMEM;
409
410 ent->segnum = segnum;
411 INIT_LIST_HEAD(&ent->list);
412 list_add_tail(&ent->list, head);
413 return 0;
414}
415
416void nilfs_dispose_segment_list(struct list_head *head)
417{
418 while (!list_empty(head)) {
419 struct nilfs_segment_entry *ent;
420
421 ent = list_first_entry(head, struct nilfs_segment_entry, list);
422 list_del(&ent->list);
423 kfree(ent);
424 }
425}
426
427static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
428 struct super_block *sb,
429 struct nilfs_recovery_info *ri)
430{
431 struct list_head *head = &ri->ri_used_segments;
432 struct nilfs_segment_entry *ent, *n;
433 struct inode *sufile = nilfs->ns_sufile;
434 __u64 segnum[4];
435 int err;
436 int i;
437
438 segnum[0] = nilfs->ns_segnum;
439 segnum[1] = nilfs->ns_nextnum;
440 segnum[2] = ri->ri_segnum;
441 segnum[3] = ri->ri_nextnum;
442
443 /*
444 * Releasing the next segment of the latest super root.
445 * The next segment is invalidated by this recovery.
446 */
447 err = nilfs_sufile_free(sufile, segnum[1]);
448 if (unlikely(err))
449 goto failed;
450
451 for (i = 1; i < 4; i++) {
452 err = nilfs_segment_list_add(head, segnum[i]);
453 if (unlikely(err))
454 goto failed;
455 }
456
457 /*
458 * Collecting segments written after the latest super root.
459 * These are marked dirty to avoid being reallocated in the next write.
460 */
461 list_for_each_entry_safe(ent, n, head, list) {
462 if (ent->segnum != segnum[0]) {
463 err = nilfs_sufile_scrap(sufile, ent->segnum);
464 if (unlikely(err))
465 goto failed;
466 }
467 list_del(&ent->list);
468 kfree(ent);
469 }
470
471 /* Allocate new segments for recovery */
472 err = nilfs_sufile_alloc(sufile, &segnum[0]);
473 if (unlikely(err))
474 goto failed;
475
476 nilfs->ns_pseg_offset = 0;
477 nilfs->ns_seg_seq = ri->ri_seq + 2;
478 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
479
480 failed:
481 /* No need to recover sufile because it will be destroyed on error */
482 return err;
483}
484
485static int nilfs_recovery_copy_block(struct the_nilfs *nilfs,
486 struct nilfs_recovery_block *rb,
487 struct page *page)
488{
489 struct buffer_head *bh_org;
490 void *kaddr;
491
492 bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize);
493 if (unlikely(!bh_org))
494 return -EIO;
495
496 kaddr = kmap_atomic(page);
497 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
498 kunmap_atomic(kaddr);
499 brelse(bh_org);
500 return 0;
501}
502
503static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs,
504 struct super_block *sb,
505 struct nilfs_root *root,
506 struct list_head *head,
507 unsigned long *nr_salvaged_blocks)
508{
509 struct inode *inode;
510 struct nilfs_recovery_block *rb, *n;
511 unsigned blocksize = nilfs->ns_blocksize;
512 struct page *page;
513 loff_t pos;
514 int err = 0, err2 = 0;
515
516 list_for_each_entry_safe(rb, n, head, list) {
517 inode = nilfs_iget(sb, root, rb->ino);
518 if (IS_ERR(inode)) {
519 err = PTR_ERR(inode);
520 inode = NULL;
521 goto failed_inode;
522 }
523
524 pos = rb->blkoff << inode->i_blkbits;
525 err = block_write_begin(inode->i_mapping, pos, blocksize,
526 0, &page, nilfs_get_block);
527 if (unlikely(err)) {
528 loff_t isize = inode->i_size;
529 if (pos + blocksize > isize)
530 nilfs_write_failed(inode->i_mapping,
531 pos + blocksize);
532 goto failed_inode;
533 }
534
535 err = nilfs_recovery_copy_block(nilfs, rb, page);
536 if (unlikely(err))
537 goto failed_page;
538
539 err = nilfs_set_file_dirty(inode, 1);
540 if (unlikely(err))
541 goto failed_page;
542
543 block_write_end(NULL, inode->i_mapping, pos, blocksize,
544 blocksize, page, NULL);
545
546 unlock_page(page);
547 put_page(page);
548
549 (*nr_salvaged_blocks)++;
550 goto next;
551
552 failed_page:
553 unlock_page(page);
554 put_page(page);
555
556 failed_inode:
557 printk(KERN_WARNING
558 "NILFS warning: error recovering data block "
559 "(err=%d, ino=%lu, block-offset=%llu)\n",
560 err, (unsigned long)rb->ino,
561 (unsigned long long)rb->blkoff);
562 if (!err2)
563 err2 = err;
564 next:
565 iput(inode); /* iput(NULL) is just ignored */
566 list_del_init(&rb->list);
567 kfree(rb);
568 }
569 return err2;
570}
571
572/**
573 * nilfs_do_roll_forward - salvage logical segments newer than the latest
574 * checkpoint
575 * @nilfs: nilfs object
576 * @sb: super block instance
577 * @ri: pointer to a nilfs_recovery_info
578 */
579static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
580 struct super_block *sb,
581 struct nilfs_root *root,
582 struct nilfs_recovery_info *ri)
583{
584 struct buffer_head *bh_sum = NULL;
585 struct nilfs_segment_summary *sum = NULL;
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 unsigned int flags;
590 u64 seg_seq;
591 __u64 segnum, nextnum = 0;
592 int empty_seg = 0;
593 int err = 0, ret;
594 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
595 enum {
596 RF_INIT_ST,
597 RF_DSYNC_ST, /* scanning data-sync segments */
598 };
599 int state = RF_INIT_ST;
600
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 brelse(bh_sum);
608 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
609 if (!bh_sum) {
610 err = -EIO;
611 goto failed;
612 }
613
614 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
615 if (ret) {
616 if (ret == NILFS_SEG_FAIL_IO) {
617 err = -EIO;
618 goto failed;
619 }
620 goto strayed;
621 }
622
623 flags = le16_to_cpu(sum->ss_flags);
624 if (flags & NILFS_SS_SR)
625 goto confused;
626
627 /* Found a valid partial segment; do recovery actions */
628 nextnum = nilfs_get_segnum_of_block(nilfs,
629 le64_to_cpu(sum->ss_next));
630 empty_seg = 0;
631 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
632 if (!(flags & NILFS_SS_GC))
633 nilfs->ns_nongc_ctime = nilfs->ns_ctime;
634
635 switch (state) {
636 case RF_INIT_ST:
637 if (!(flags & NILFS_SS_LOGBGN) ||
638 !(flags & NILFS_SS_SYNDT))
639 goto try_next_pseg;
640 state = RF_DSYNC_ST;
641 /* Fall through */
642 case RF_DSYNC_ST:
643 if (!(flags & NILFS_SS_SYNDT))
644 goto confused;
645
646 err = nilfs_scan_dsync_log(nilfs, pseg_start, sum,
647 &dsync_blocks);
648 if (unlikely(err))
649 goto failed;
650 if (flags & NILFS_SS_LOGEND) {
651 err = nilfs_recover_dsync_blocks(
652 nilfs, sb, root, &dsync_blocks,
653 &nsalvaged_blocks);
654 if (unlikely(err))
655 goto failed;
656 state = RF_INIT_ST;
657 }
658 break; /* Fall through to try_next_pseg */
659 }
660
661 try_next_pseg:
662 if (pseg_start == ri->ri_lsegs_end)
663 break;
664 pseg_start += le32_to_cpu(sum->ss_nblocks);
665 if (pseg_start < seg_end)
666 continue;
667 goto feed_segment;
668
669 strayed:
670 if (pseg_start == ri->ri_lsegs_end)
671 break;
672
673 feed_segment:
674 /* Looking to the next full segment */
675 if (empty_seg++)
676 break;
677 seg_seq++;
678 segnum = nextnum;
679 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
680 pseg_start = seg_start;
681 }
682
683 if (nsalvaged_blocks) {
684 printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n",
685 sb->s_id, nsalvaged_blocks);
686 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
687 }
688 out:
689 brelse(bh_sum);
690 dispose_recovery_list(&dsync_blocks);
691 return err;
692
693 confused:
694 err = -EINVAL;
695 failed:
696 printk(KERN_ERR
697 "NILFS (device %s): Error roll-forwarding "
698 "(err=%d, pseg block=%llu). ",
699 sb->s_id, err, (unsigned long long)pseg_start);
700 goto out;
701}
702
703static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
704 struct nilfs_recovery_info *ri)
705{
706 struct buffer_head *bh;
707 int err;
708
709 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) !=
710 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root))
711 return;
712
713 bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize);
714 BUG_ON(!bh);
715 memset(bh->b_data, 0, bh->b_size);
716 set_buffer_dirty(bh);
717 err = sync_dirty_buffer(bh);
718 if (unlikely(err))
719 printk(KERN_WARNING
720 "NILFS warning: buffer sync write failed during "
721 "post-cleaning of recovery.\n");
722 brelse(bh);
723}
724
725/**
726 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint
727 * @nilfs: nilfs object
728 * @sb: super block instance
729 * @ri: pointer to a nilfs_recovery_info struct to store search results.
730 *
731 * Return Value: On success, 0 is returned. On error, one of the following
732 * negative error code is returned.
733 *
734 * %-EINVAL - Inconsistent filesystem state.
735 *
736 * %-EIO - I/O error
737 *
738 * %-ENOSPC - No space left on device (only in a panic state).
739 *
740 * %-ERESTARTSYS - Interrupted.
741 *
742 * %-ENOMEM - Insufficient memory available.
743 */
744int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs,
745 struct super_block *sb,
746 struct nilfs_recovery_info *ri)
747{
748 struct nilfs_root *root;
749 int err;
750
751 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
752 return 0;
753
754 err = nilfs_attach_checkpoint(sb, ri->ri_cno, true, &root);
755 if (unlikely(err)) {
756 printk(KERN_ERR
757 "NILFS: error loading the latest checkpoint.\n");
758 return err;
759 }
760
761 err = nilfs_do_roll_forward(nilfs, sb, root, ri);
762 if (unlikely(err))
763 goto failed;
764
765 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
766 err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri);
767 if (unlikely(err)) {
768 printk(KERN_ERR "NILFS: Error preparing segments for "
769 "recovery.\n");
770 goto failed;
771 }
772
773 err = nilfs_attach_log_writer(sb, root);
774 if (unlikely(err))
775 goto failed;
776
777 set_nilfs_discontinued(nilfs);
778 err = nilfs_construct_segment(sb);
779 nilfs_detach_log_writer(sb);
780
781 if (unlikely(err)) {
782 printk(KERN_ERR "NILFS: Oops! recovery failed. "
783 "(err=%d)\n", err);
784 goto failed;
785 }
786
787 nilfs_finish_roll_forward(nilfs, ri);
788 }
789
790 failed:
791 nilfs_put_root(root);
792 return err;
793}
794
795/**
796 * nilfs_search_super_root - search the latest valid super root
797 * @nilfs: the_nilfs
798 * @ri: pointer to a nilfs_recovery_info struct to store search results.
799 *
800 * nilfs_search_super_root() looks for the latest super-root from a partial
801 * segment pointed by the superblock. It sets up struct the_nilfs through
802 * this search. It fills nilfs_recovery_info (ri) required for recovery.
803 *
804 * Return Value: On success, 0 is returned. On error, one of the following
805 * negative error code is returned.
806 *
807 * %-EINVAL - No valid segment found
808 *
809 * %-EIO - I/O error
810 *
811 * %-ENOMEM - Insufficient memory available.
812 */
813int nilfs_search_super_root(struct the_nilfs *nilfs,
814 struct nilfs_recovery_info *ri)
815{
816 struct buffer_head *bh_sum = NULL;
817 struct nilfs_segment_summary *sum = NULL;
818 sector_t pseg_start, pseg_end, sr_pseg_start = 0;
819 sector_t seg_start, seg_end; /* range of full segment (block number) */
820 sector_t b, end;
821 unsigned long nblocks;
822 unsigned int flags;
823 u64 seg_seq;
824 __u64 segnum, nextnum = 0;
825 __u64 cno;
826 LIST_HEAD(segments);
827 int empty_seg = 0, scan_newer = 0;
828 int ret;
829
830 pseg_start = nilfs->ns_last_pseg;
831 seg_seq = nilfs->ns_last_seq;
832 cno = nilfs->ns_last_cno;
833 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
834
835 /* Calculate range of segment */
836 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
837
838 /* Read ahead segment */
839 b = seg_start;
840 while (b <= seg_end)
841 __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize);
842
843 for (;;) {
844 brelse(bh_sum);
845 ret = NILFS_SEG_FAIL_IO;
846 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum);
847 if (!bh_sum)
848 goto failed;
849
850 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum);
851 if (ret) {
852 if (ret == NILFS_SEG_FAIL_IO)
853 goto failed;
854 goto strayed;
855 }
856
857 nblocks = le32_to_cpu(sum->ss_nblocks);
858 pseg_end = pseg_start + nblocks - 1;
859 if (unlikely(pseg_end > seg_end)) {
860 ret = NILFS_SEG_FAIL_CONSISTENCY;
861 goto strayed;
862 }
863
864 /* A valid partial segment */
865 ri->ri_pseg_start = pseg_start;
866 ri->ri_seq = seg_seq;
867 ri->ri_segnum = segnum;
868 nextnum = nilfs_get_segnum_of_block(nilfs,
869 le64_to_cpu(sum->ss_next));
870 ri->ri_nextnum = nextnum;
871 empty_seg = 0;
872
873 flags = le16_to_cpu(sum->ss_flags);
874 if (!(flags & NILFS_SS_SR) && !scan_newer) {
875 /* This will never happen because a superblock
876 (last_segment) always points to a pseg
877 having a super root. */
878 ret = NILFS_SEG_FAIL_CONSISTENCY;
879 goto failed;
880 }
881
882 if (pseg_start == seg_start) {
883 nilfs_get_segment_range(nilfs, nextnum, &b, &end);
884 while (b <= end)
885 __breadahead(nilfs->ns_bdev, b++,
886 nilfs->ns_blocksize);
887 }
888 if (!(flags & NILFS_SS_SR)) {
889 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) {
890 ri->ri_lsegs_start = pseg_start;
891 ri->ri_lsegs_start_seq = seg_seq;
892 }
893 if (flags & NILFS_SS_LOGEND)
894 ri->ri_lsegs_end = pseg_start;
895 goto try_next_pseg;
896 }
897
898 /* A valid super root was found. */
899 ri->ri_cno = cno++;
900 ri->ri_super_root = pseg_end;
901 ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
902
903 nilfs_dispose_segment_list(&segments);
904 sr_pseg_start = pseg_start;
905 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start;
906 nilfs->ns_seg_seq = seg_seq;
907 nilfs->ns_segnum = segnum;
908 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
909 nilfs->ns_ctime = le64_to_cpu(sum->ss_create);
910 nilfs->ns_nextnum = nextnum;
911
912 if (scan_newer)
913 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
914 else {
915 if (nilfs->ns_mount_state & NILFS_VALID_FS)
916 goto super_root_found;
917 scan_newer = 1;
918 }
919
920 try_next_pseg:
921 /* Standing on a course, or met an inconsistent state */
922 pseg_start += nblocks;
923 if (pseg_start < seg_end)
924 continue;
925 goto feed_segment;
926
927 strayed:
928 /* Off the trail */
929 if (!scan_newer)
930 /*
931 * This can happen if a checkpoint was written without
932 * barriers, or as a result of an I/O failure.
933 */
934 goto failed;
935
936 feed_segment:
937 /* Looking to the next full segment */
938 if (empty_seg++)
939 goto super_root_found; /* found a valid super root */
940
941 ret = nilfs_segment_list_add(&segments, segnum);
942 if (unlikely(ret))
943 goto failed;
944
945 seg_seq++;
946 segnum = nextnum;
947 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
948 pseg_start = seg_start;
949 }
950
951 super_root_found:
952 /* Updating pointers relating to the latest checkpoint */
953 brelse(bh_sum);
954 list_splice_tail(&segments, &ri->ri_used_segments);
955 nilfs->ns_last_pseg = sr_pseg_start;
956 nilfs->ns_last_seq = nilfs->ns_seg_seq;
957 nilfs->ns_last_cno = ri->ri_cno;
958 return 0;
959
960 failed:
961 brelse(bh_sum);
962 nilfs_dispose_segment_list(&segments);
963 return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
964}