2 * recovery.c - NILFS recovery logic
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
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
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
23 #include <linux/buffer_head.h>
24 #include <linux/blkdev.h>
25 #include <linux/swap.h>
26 #include <linux/crc32.h>
35 * Segment check result
39 NILFS_SEG_NO_SUPER_ROOT
,
43 NILFS_SEG_FAIL_CHECKSUM_SEGSUM
,
44 NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
,
45 NILFS_SEG_FAIL_CHECKSUM_FULL
,
46 NILFS_SEG_FAIL_CONSISTENCY
,
49 /* work structure for recovery */
50 struct nilfs_recovery_block
{
51 ino_t ino
; /* Inode number of the file that this block
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
;
60 static int nilfs_warn_segment_error(int err
)
63 case NILFS_SEG_FAIL_IO
:
65 "NILFS warning: I/O error on loading last segment\n");
67 case NILFS_SEG_FAIL_MAGIC
:
69 "NILFS warning: Segment magic number invalid\n");
71 case NILFS_SEG_FAIL_SEQ
:
73 "NILFS warning: Sequence number mismatch\n");
75 case NILFS_SEG_FAIL_CHECKSUM_SEGSUM
:
77 "NILFS warning: Checksum error in segment summary\n");
79 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
:
81 "NILFS warning: Checksum error in super root\n");
83 case NILFS_SEG_FAIL_CHECKSUM_FULL
:
85 "NILFS warning: Checksum error in segment payload\n");
87 case NILFS_SEG_FAIL_CONSISTENCY
:
89 "NILFS warning: Inconsistent segment\n");
91 case NILFS_SEG_NO_SUPER_ROOT
:
93 "NILFS warning: No super root in the last segment\n");
99 static void store_segsum_info(struct nilfs_segsum_info
*ssi
,
100 struct nilfs_segment_summary
*sum
,
101 unsigned int blocksize
)
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
);
111 ssi
->nsumblk
= DIV_ROUND_UP(ssi
->sumbytes
, blocksize
);
112 ssi
->nfileblk
= ssi
->nblocks
- ssi
->nsumblk
- !!NILFS_SEG_HAS_SR(ssi
);
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
125 static 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
)
129 unsigned long blocksize
= sbi
->s_super
->s_blocksize
;
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
);
140 struct buffer_head
*bh
141 = sb_bread(sbi
->s_super
, ++start
);
145 size
= min_t(u64
, check_bytes
, blocksize
);
146 crc
= crc32_le(crc
, bh
->b_data
, size
);
148 } while (--nblock
> 0);
155 * nilfs_read_super_root_block - read super root 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
161 int nilfs_read_super_root_block(struct super_block
*sb
, sector_t sr_block
,
162 struct buffer_head
**pbh
, int check
)
164 struct buffer_head
*bh_sr
;
165 struct nilfs_super_root
*sr
;
170 bh_sr
= sb_bread(sb
, sr_block
);
171 if (unlikely(!bh_sr
)) {
172 ret
= NILFS_SEG_FAIL_IO
;
176 sr
= (struct nilfs_super_root
*)bh_sr
->b_data
;
178 unsigned bytes
= le16_to_cpu(sr
->sr_bytes
);
180 if (bytes
== 0 || bytes
> sb
->s_blocksize
) {
181 ret
= NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
;
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
;
189 if (crc
!= le32_to_cpu(sr
->sr_sum
)) {
190 ret
= NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
;
201 return nilfs_warn_segment_error(ret
);
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)
214 load_segment_summary(struct nilfs_sb_info
*sbi
, sector_t pseg_start
,
215 u64 seg_seq
, struct nilfs_segsum_info
*ssi
,
218 struct buffer_head
*bh_sum
;
219 struct nilfs_segment_summary
*sum
;
220 unsigned long offset
, nblock
;
223 int ret
= NILFS_SEG_FAIL_IO
;
225 bh_sum
= sb_bread(sbi
->s_super
, pseg_start
);
229 sum
= (struct nilfs_segment_summary
*)bh_sum
->b_data
;
231 /* Check consistency of segment summary */
232 if (le32_to_cpu(sum
->ss_magic
) != NILFS_SEGSUM_MAGIC
) {
233 ret
= NILFS_SEG_FAIL_MAGIC
;
236 store_segsum_info(ssi
, sum
, sbi
->s_super
->s_blocksize
);
237 if (seg_seq
!= ssi
->seg_seq
) {
238 ret
= NILFS_SEG_FAIL_SEQ
;
242 offset
= sizeof(sum
->ss_datasum
);
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
;
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
;
262 if (calc_crc_cont(sbi
, bh_sum
, &crc
, offset
, check_bytes
,
263 pseg_start
, nblock
)) {
264 ret
= NILFS_SEG_FAIL_IO
;
275 static void *segsum_get(struct super_block
*sb
, struct buffer_head
**pbh
,
276 unsigned int *offset
, unsigned int bytes
)
281 BUG_ON((*pbh
)->b_size
< *offset
);
282 if (bytes
> (*pbh
)->b_size
- *offset
) {
283 blocknr
= (*pbh
)->b_blocknr
;
285 *pbh
= sb_bread(sb
, blocknr
+ 1);
290 ptr
= (*pbh
)->b_data
+ *offset
;
295 static void segsum_skip(struct super_block
*sb
, struct buffer_head
**pbh
,
296 unsigned int *offset
, unsigned int bytes
,
299 unsigned int rest_item_in_current_block
300 = ((*pbh
)->b_size
- *offset
) / bytes
;
302 if (count
<= rest_item_in_current_block
) {
303 *offset
+= bytes
* count
;
305 sector_t blocknr
= (*pbh
)->b_blocknr
;
306 unsigned int nitem_per_block
= (*pbh
)->b_size
/ bytes
;
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
);
314 *pbh
= sb_bread(sb
, blocknr
+ bcnt
);
319 collect_blocks_from_segsum(struct nilfs_sb_info
*sbi
, sector_t sum_blocknr
,
320 struct nilfs_segsum_info
*ssi
,
321 struct list_head
*head
)
323 struct buffer_head
*bh
;
325 unsigned long nfinfo
= ssi
->nfinfo
;
326 sector_t blocknr
= sum_blocknr
+ ssi
->nsumblk
;
333 bh
= sb_bread(sbi
->s_super
, sum_blocknr
);
337 offset
= le16_to_cpu(
338 ((struct nilfs_segment_summary
*)bh
->b_data
)->ss_bytes
);
340 unsigned long nblocks
, ndatablk
, nnodeblk
;
341 struct nilfs_finfo
*finfo
;
343 finfo
= segsum_get(sbi
->s_super
, &bh
, &offset
, sizeof(*finfo
));
344 if (unlikely(!finfo
))
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
;
352 while (ndatablk
-- > 0) {
353 struct nilfs_recovery_block
*rb
;
354 struct nilfs_binfo_v
*binfo
;
356 binfo
= segsum_get(sbi
->s_super
, &bh
, &offset
,
358 if (unlikely(!binfo
))
361 rb
= kmalloc(sizeof(*rb
), GFP_NOFS
);
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
);
375 blocknr
+= nnodeblk
; /* always 0 for the data sync segments */
376 segsum_skip(sbi
->s_super
, &bh
, &offset
, sizeof(__le64
),
383 brelse(bh
); /* brelse(NULL) is just ignored */
387 static void dispose_recovery_list(struct list_head
*head
)
389 while (!list_empty(head
)) {
390 struct nilfs_recovery_block
*rb
391 = list_entry(head
->next
,
392 struct nilfs_recovery_block
, list
);
398 void nilfs_dispose_segment_list(struct list_head
*head
)
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
);
409 static int nilfs_prepare_segment_for_recovery(struct the_nilfs
*nilfs
,
410 struct nilfs_recovery_info
*ri
)
412 struct list_head
*head
= &ri
->ri_used_segments
;
413 struct nilfs_segment_entry
*ent
, *n
;
414 struct inode
*sufile
= nilfs
->ns_sufile
;
420 segnum
[0] = nilfs
->ns_segnum
;
421 segnum
[1] = nilfs
->ns_nextnum
;
422 segnum
[2] = ri
->ri_segnum
;
423 segnum
[3] = ri
->ri_nextnum
;
426 * Releasing the next segment of the latest super root.
427 * The next segment is invalidated by this recovery.
429 err
= nilfs_sufile_free(sufile
, segnum
[1]);
434 for (i
= 1; i
< 4; i
++) {
435 ent
= nilfs_alloc_segment_entry(segnum
[i
]);
438 list_add_tail(&ent
->list
, head
);
442 * Collecting segments written after the latest super root.
443 * These are marked dirty to avoid being reallocated in the next write.
445 mtime
= get_seconds();
446 list_for_each_entry_safe(ent
, n
, head
, list
) {
447 if (ent
->segnum
== segnum
[0]) {
448 list_del(&ent
->list
);
449 nilfs_free_segment_entry(ent
);
452 err
= nilfs_open_segment_entry(ent
, sufile
);
455 if (!nilfs_segment_usage_dirty(ent
->raw_su
)) {
456 /* make the segment garbage */
457 ent
->raw_su
->su_nblocks
= cpu_to_le32(0);
458 ent
->raw_su
->su_lastmod
= cpu_to_le32(mtime
);
459 nilfs_segment_usage_set_dirty(ent
->raw_su
);
461 list_del(&ent
->list
);
462 nilfs_close_segment_entry(ent
, sufile
);
463 nilfs_free_segment_entry(ent
);
466 /* Allocate new segments for recovery */
467 err
= nilfs_sufile_alloc(sufile
, &segnum
[0]);
471 nilfs
->ns_pseg_offset
= 0;
472 nilfs
->ns_seg_seq
= ri
->ri_seq
+ 2;
473 nilfs
->ns_nextnum
= nilfs
->ns_segnum
= segnum
[0];
477 /* No need to recover sufile because it will be destroyed on error */
481 static int nilfs_recovery_copy_block(struct nilfs_sb_info
*sbi
,
482 struct nilfs_recovery_block
*rb
,
485 struct buffer_head
*bh_org
;
488 bh_org
= sb_bread(sbi
->s_super
, rb
->blocknr
);
489 if (unlikely(!bh_org
))
492 kaddr
= kmap_atomic(page
, KM_USER0
);
493 memcpy(kaddr
+ bh_offset(bh_org
), bh_org
->b_data
, bh_org
->b_size
);
494 kunmap_atomic(kaddr
, KM_USER0
);
499 static int recover_dsync_blocks(struct nilfs_sb_info
*sbi
,
500 struct list_head
*head
,
501 unsigned long *nr_salvaged_blocks
)
504 struct nilfs_recovery_block
*rb
, *n
;
505 unsigned blocksize
= sbi
->s_super
->s_blocksize
;
508 int err
= 0, err2
= 0;
510 list_for_each_entry_safe(rb
, n
, head
, list
) {
511 inode
= nilfs_iget(sbi
->s_super
, rb
->ino
);
513 err
= PTR_ERR(inode
);
518 pos
= rb
->blkoff
<< inode
->i_blkbits
;
520 err
= block_write_begin(NULL
, inode
->i_mapping
, pos
, blocksize
,
521 0, &page
, NULL
, nilfs_get_block
);
525 err
= nilfs_recovery_copy_block(sbi
, rb
, page
);
529 err
= nilfs_set_file_dirty(sbi
, inode
, 1);
533 block_write_end(NULL
, inode
->i_mapping
, pos
, blocksize
,
534 blocksize
, page
, NULL
);
537 page_cache_release(page
);
539 (*nr_salvaged_blocks
)++;
544 page_cache_release(page
);
548 "NILFS warning: error recovering data block "
549 "(err=%d, ino=%lu, block-offset=%llu)\n",
550 err
, rb
->ino
, (unsigned long long)rb
->blkoff
);
554 iput(inode
); /* iput(NULL) is just ignored */
555 list_del_init(&rb
->list
);
562 * nilfs_do_roll_forward - salvage logical segments newer than the latest
564 * @sbi: nilfs_sb_info
566 * @ri: pointer to a nilfs_recovery_info
568 static int nilfs_do_roll_forward(struct the_nilfs
*nilfs
,
569 struct nilfs_sb_info
*sbi
,
570 struct nilfs_recovery_info
*ri
)
572 struct nilfs_segsum_info ssi
;
574 sector_t seg_start
, seg_end
; /* Starting/ending DBN of full segment */
575 unsigned long nsalvaged_blocks
= 0;
577 __u64 segnum
, nextnum
= 0;
580 LIST_HEAD(dsync_blocks
); /* list of data blocks to be recovered */
583 RF_DSYNC_ST
, /* scanning data-sync segments */
585 int state
= RF_INIT_ST
;
587 nilfs_attach_writer(nilfs
, sbi
);
588 pseg_start
= ri
->ri_lsegs_start
;
589 seg_seq
= ri
->ri_lsegs_start_seq
;
590 segnum
= nilfs_get_segnum_of_block(nilfs
, pseg_start
);
591 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
593 while (segnum
!= ri
->ri_segnum
|| pseg_start
<= ri
->ri_pseg_start
) {
595 ret
= load_segment_summary(sbi
, pseg_start
, seg_seq
, &ssi
, 1);
597 if (ret
== NILFS_SEG_FAIL_IO
) {
603 if (unlikely(NILFS_SEG_HAS_SR(&ssi
)))
606 /* Found a valid partial segment; do recovery actions */
607 nextnum
= nilfs_get_segnum_of_block(nilfs
, ssi
.next
);
609 nilfs
->ns_ctime
= ssi
.ctime
;
610 if (!(ssi
.flags
& NILFS_SS_GC
))
611 nilfs
->ns_nongc_ctime
= ssi
.ctime
;
615 if (!NILFS_SEG_LOGBGN(&ssi
) || !NILFS_SEG_DSYNC(&ssi
))
620 if (!NILFS_SEG_DSYNC(&ssi
))
623 err
= collect_blocks_from_segsum(
624 sbi
, pseg_start
, &ssi
, &dsync_blocks
);
627 if (NILFS_SEG_LOGEND(&ssi
)) {
628 err
= recover_dsync_blocks(
629 sbi
, &dsync_blocks
, &nsalvaged_blocks
);
634 break; /* Fall through to try_next_pseg */
638 if (pseg_start
== ri
->ri_lsegs_end
)
640 pseg_start
+= ssi
.nblocks
;
641 if (pseg_start
< seg_end
)
646 if (pseg_start
== ri
->ri_lsegs_end
)
650 /* Looking to the next full segment */
655 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
656 pseg_start
= seg_start
;
659 if (nsalvaged_blocks
) {
660 printk(KERN_INFO
"NILFS (device %s): salvaged %lu blocks\n",
661 sbi
->s_super
->s_id
, nsalvaged_blocks
);
662 ri
->ri_need_recovery
= NILFS_RECOVERY_ROLLFORWARD_DONE
;
665 dispose_recovery_list(&dsync_blocks
);
666 nilfs_detach_writer(sbi
->s_nilfs
, sbi
);
673 "NILFS (device %s): Error roll-forwarding "
674 "(err=%d, pseg block=%llu). ",
675 sbi
->s_super
->s_id
, err
, (unsigned long long)pseg_start
);
679 static void nilfs_finish_roll_forward(struct the_nilfs
*nilfs
,
680 struct nilfs_sb_info
*sbi
,
681 struct nilfs_recovery_info
*ri
)
683 struct buffer_head
*bh
;
686 if (nilfs_get_segnum_of_block(nilfs
, ri
->ri_lsegs_start
) !=
687 nilfs_get_segnum_of_block(nilfs
, ri
->ri_super_root
))
690 bh
= sb_getblk(sbi
->s_super
, ri
->ri_lsegs_start
);
692 memset(bh
->b_data
, 0, bh
->b_size
);
693 set_buffer_dirty(bh
);
694 err
= sync_dirty_buffer(bh
);
697 "NILFS warning: buffer sync write failed during "
698 "post-cleaning of recovery.\n");
703 * nilfs_recover_logical_segments - salvage logical segments written after
704 * the latest super root
706 * @sbi: nilfs_sb_info
707 * @ri: pointer to a nilfs_recovery_info struct to store search results.
709 * Return Value: On success, 0 is returned. On error, one of the following
710 * negative error code is returned.
712 * %-EINVAL - Inconsistent filesystem state.
716 * %-ENOSPC - No space left on device (only in a panic state).
718 * %-ERESTARTSYS - Interrupted.
720 * %-ENOMEM - Insufficient memory available.
722 int nilfs_recover_logical_segments(struct the_nilfs
*nilfs
,
723 struct nilfs_sb_info
*sbi
,
724 struct nilfs_recovery_info
*ri
)
728 if (ri
->ri_lsegs_start
== 0 || ri
->ri_lsegs_end
== 0)
731 err
= nilfs_attach_checkpoint(sbi
, ri
->ri_cno
);
734 "NILFS: error loading the latest checkpoint.\n");
738 err
= nilfs_do_roll_forward(nilfs
, sbi
, ri
);
742 if (ri
->ri_need_recovery
== NILFS_RECOVERY_ROLLFORWARD_DONE
) {
743 err
= nilfs_prepare_segment_for_recovery(nilfs
, ri
);
745 printk(KERN_ERR
"NILFS: Error preparing segments for "
750 err
= nilfs_attach_segment_constructor(sbi
);
754 set_nilfs_discontinued(nilfs
);
755 err
= nilfs_construct_segment(sbi
->s_super
);
756 nilfs_detach_segment_constructor(sbi
);
759 printk(KERN_ERR
"NILFS: Oops! recovery failed. "
764 nilfs_finish_roll_forward(nilfs
, sbi
, ri
);
767 nilfs_detach_checkpoint(sbi
);
771 nilfs_detach_checkpoint(sbi
);
772 nilfs_mdt_clear(nilfs
->ns_cpfile
);
773 nilfs_mdt_clear(nilfs
->ns_sufile
);
774 nilfs_mdt_clear(nilfs
->ns_dat
);
779 * nilfs_search_super_root - search the latest valid super root
781 * @sbi: nilfs_sb_info
782 * @ri: pointer to a nilfs_recovery_info struct to store search results.
784 * nilfs_search_super_root() looks for the latest super-root from a partial
785 * segment pointed by the superblock. It sets up struct the_nilfs through
786 * this search. It fills nilfs_recovery_info (ri) required for recovery.
788 * Return Value: On success, 0 is returned. On error, one of the following
789 * negative error code is returned.
791 * %-EINVAL - No valid segment found
795 int nilfs_search_super_root(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
,
796 struct nilfs_recovery_info
*ri
)
798 struct nilfs_segsum_info ssi
;
799 sector_t pseg_start
, pseg_end
, sr_pseg_start
= 0;
800 sector_t seg_start
, seg_end
; /* range of full segment (block number) */
802 __u64 segnum
, nextnum
= 0;
804 struct nilfs_segment_entry
*ent
;
806 int empty_seg
= 0, scan_newer
= 0;
809 pseg_start
= nilfs
->ns_last_pseg
;
810 seg_seq
= nilfs
->ns_last_seq
;
811 cno
= nilfs
->ns_last_cno
;
812 segnum
= nilfs_get_segnum_of_block(nilfs
, pseg_start
);
814 /* Calculate range of segment */
815 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
818 /* Load segment summary */
819 ret
= load_segment_summary(sbi
, pseg_start
, seg_seq
, &ssi
, 1);
821 if (ret
== NILFS_SEG_FAIL_IO
)
825 pseg_end
= pseg_start
+ ssi
.nblocks
- 1;
826 if (unlikely(pseg_end
> seg_end
)) {
827 ret
= NILFS_SEG_FAIL_CONSISTENCY
;
831 /* A valid partial segment */
832 ri
->ri_pseg_start
= pseg_start
;
833 ri
->ri_seq
= seg_seq
;
834 ri
->ri_segnum
= segnum
;
835 nextnum
= nilfs_get_segnum_of_block(nilfs
, ssi
.next
);
836 ri
->ri_nextnum
= nextnum
;
839 if (!NILFS_SEG_HAS_SR(&ssi
)) {
841 /* This will never happen because a superblock
842 (last_segment) always points to a pseg
843 having a super root. */
844 ret
= NILFS_SEG_FAIL_CONSISTENCY
;
847 if (!ri
->ri_lsegs_start
&& NILFS_SEG_LOGBGN(&ssi
)) {
848 ri
->ri_lsegs_start
= pseg_start
;
849 ri
->ri_lsegs_start_seq
= seg_seq
;
851 if (NILFS_SEG_LOGEND(&ssi
))
852 ri
->ri_lsegs_end
= pseg_start
;
856 /* A valid super root was found. */
858 ri
->ri_super_root
= pseg_end
;
859 ri
->ri_lsegs_start
= ri
->ri_lsegs_end
= 0;
861 nilfs_dispose_segment_list(&segments
);
862 nilfs
->ns_pseg_offset
= (sr_pseg_start
= pseg_start
)
863 + ssi
.nblocks
- seg_start
;
864 nilfs
->ns_seg_seq
= seg_seq
;
865 nilfs
->ns_segnum
= segnum
;
866 nilfs
->ns_cno
= cno
; /* nilfs->ns_cno = ri->ri_cno + 1 */
867 nilfs
->ns_ctime
= ssi
.ctime
;
868 nilfs
->ns_nextnum
= nextnum
;
871 ri
->ri_need_recovery
= NILFS_RECOVERY_SR_UPDATED
;
873 if (nilfs
->ns_mount_state
& NILFS_VALID_FS
)
874 goto super_root_found
;
878 /* reset region for roll-forward */
879 pseg_start
+= ssi
.nblocks
;
880 if (pseg_start
< seg_end
)
885 /* Standing on a course, or met an inconsistent state */
886 pseg_start
+= ssi
.nblocks
;
887 if (pseg_start
< seg_end
)
895 * This can happen if a checkpoint was written without
896 * barriers, or as a result of an I/O failure.
901 /* Looking to the next full segment */
903 goto super_root_found
; /* found a valid super root */
905 ent
= nilfs_alloc_segment_entry(segnum
);
906 if (unlikely(!ent
)) {
910 list_add_tail(&ent
->list
, &segments
);
914 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
915 pseg_start
= seg_start
;
919 /* Updating pointers relating to the latest checkpoint */
920 list_splice(&segments
, ri
->ri_used_segments
.prev
);
921 nilfs
->ns_last_pseg
= sr_pseg_start
;
922 nilfs
->ns_last_seq
= nilfs
->ns_seg_seq
;
923 nilfs
->ns_last_cno
= ri
->ri_cno
;
927 nilfs_dispose_segment_list(&segments
);
928 return (ret
< 0) ? ret
: nilfs_warn_segment_error(ret
);