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");
102 static void store_segsum_info(struct nilfs_segsum_info
*ssi
,
103 struct nilfs_segment_summary
*sum
,
104 unsigned int blocksize
)
106 ssi
->flags
= le16_to_cpu(sum
->ss_flags
);
107 ssi
->seg_seq
= le64_to_cpu(sum
->ss_seq
);
108 ssi
->ctime
= le64_to_cpu(sum
->ss_create
);
109 ssi
->next
= le64_to_cpu(sum
->ss_next
);
110 ssi
->nblocks
= le32_to_cpu(sum
->ss_nblocks
);
111 ssi
->nfinfo
= le32_to_cpu(sum
->ss_nfinfo
);
112 ssi
->sumbytes
= le32_to_cpu(sum
->ss_sumbytes
);
114 ssi
->nsumblk
= DIV_ROUND_UP(ssi
->sumbytes
, blocksize
);
115 ssi
->nfileblk
= ssi
->nblocks
- ssi
->nsumblk
- !!NILFS_SEG_HAS_SR(ssi
);
119 * calc_crc_cont - check CRC of blocks continuously
120 * @sbi: nilfs_sb_info
121 * @bhs: buffer head of start block
122 * @sum: place to store result
123 * @offset: offset bytes in the first block
124 * @check_bytes: number of bytes to be checked
125 * @start: DBN of start block
126 * @nblock: number of blocks to be checked
128 static int calc_crc_cont(struct nilfs_sb_info
*sbi
, struct buffer_head
*bhs
,
129 u32
*sum
, unsigned long offset
, u64 check_bytes
,
130 sector_t start
, unsigned long nblock
)
132 unsigned long blocksize
= sbi
->s_super
->s_blocksize
;
136 BUG_ON(offset
>= blocksize
);
137 check_bytes
-= offset
;
138 size
= min_t(u64
, check_bytes
, blocksize
- offset
);
139 crc
= crc32_le(sbi
->s_nilfs
->ns_crc_seed
,
140 (unsigned char *)bhs
->b_data
+ offset
, size
);
143 struct buffer_head
*bh
144 = sb_bread(sbi
->s_super
, ++start
);
148 size
= min_t(u64
, check_bytes
, blocksize
);
149 crc
= crc32_le(crc
, bh
->b_data
, size
);
151 } while (--nblock
> 0);
158 * nilfs_read_super_root_block - read super root block
160 * @sr_block: disk block number of the super root block
161 * @pbh: address of a buffer_head pointer to return super root buffer
162 * @check: CRC check flag
164 int nilfs_read_super_root_block(struct super_block
*sb
, sector_t sr_block
,
165 struct buffer_head
**pbh
, int check
)
167 struct buffer_head
*bh_sr
;
168 struct nilfs_super_root
*sr
;
173 bh_sr
= sb_bread(sb
, sr_block
);
174 if (unlikely(!bh_sr
)) {
175 ret
= NILFS_SEG_FAIL_IO
;
179 sr
= (struct nilfs_super_root
*)bh_sr
->b_data
;
181 unsigned bytes
= le16_to_cpu(sr
->sr_bytes
);
183 if (bytes
== 0 || bytes
> sb
->s_blocksize
) {
184 ret
= NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
;
187 if (calc_crc_cont(NILFS_SB(sb
), bh_sr
, &crc
,
188 sizeof(sr
->sr_sum
), bytes
, sr_block
, 1)) {
189 ret
= NILFS_SEG_FAIL_IO
;
192 if (crc
!= le32_to_cpu(sr
->sr_sum
)) {
193 ret
= NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT
;
204 return nilfs_warn_segment_error(ret
);
208 * load_segment_summary - read segment summary of the specified partial segment
209 * @sbi: nilfs_sb_info
210 * @pseg_start: start disk block number of partial segment
211 * @seg_seq: sequence number requested
212 * @ssi: pointer to nilfs_segsum_info struct to store information
213 * @full_check: full check flag
214 * (0: only checks segment summary CRC, 1: data CRC)
217 load_segment_summary(struct nilfs_sb_info
*sbi
, sector_t pseg_start
,
218 u64 seg_seq
, struct nilfs_segsum_info
*ssi
,
221 struct buffer_head
*bh_sum
;
222 struct nilfs_segment_summary
*sum
;
223 unsigned long offset
, nblock
;
226 int ret
= NILFS_SEG_FAIL_IO
;
228 bh_sum
= sb_bread(sbi
->s_super
, pseg_start
);
232 sum
= (struct nilfs_segment_summary
*)bh_sum
->b_data
;
234 /* Check consistency of segment summary */
235 if (le32_to_cpu(sum
->ss_magic
) != NILFS_SEGSUM_MAGIC
) {
236 ret
= NILFS_SEG_FAIL_MAGIC
;
239 store_segsum_info(ssi
, sum
, sbi
->s_super
->s_blocksize
);
240 if (seg_seq
!= ssi
->seg_seq
) {
241 ret
= NILFS_SEG_FAIL_SEQ
;
245 offset
= sizeof(sum
->ss_datasum
);
247 ((u64
)ssi
->nblocks
<< sbi
->s_super
->s_blocksize_bits
);
248 nblock
= ssi
->nblocks
;
249 crc_sum
= le32_to_cpu(sum
->ss_datasum
);
250 ret
= NILFS_SEG_FAIL_CHECKSUM_FULL
;
251 } else { /* only checks segment summary */
252 offset
= sizeof(sum
->ss_datasum
) + sizeof(sum
->ss_sumsum
);
253 check_bytes
= ssi
->sumbytes
;
254 nblock
= ssi
->nsumblk
;
255 crc_sum
= le32_to_cpu(sum
->ss_sumsum
);
256 ret
= NILFS_SEG_FAIL_CHECKSUM_SEGSUM
;
259 if (unlikely(nblock
== 0 ||
260 nblock
> sbi
->s_nilfs
->ns_blocks_per_segment
)) {
261 /* This limits the number of blocks read in the CRC check */
262 ret
= NILFS_SEG_FAIL_CONSISTENCY
;
265 if (calc_crc_cont(sbi
, bh_sum
, &crc
, offset
, check_bytes
,
266 pseg_start
, nblock
)) {
267 ret
= NILFS_SEG_FAIL_IO
;
278 static void *segsum_get(struct super_block
*sb
, struct buffer_head
**pbh
,
279 unsigned int *offset
, unsigned int bytes
)
284 BUG_ON((*pbh
)->b_size
< *offset
);
285 if (bytes
> (*pbh
)->b_size
- *offset
) {
286 blocknr
= (*pbh
)->b_blocknr
;
288 *pbh
= sb_bread(sb
, blocknr
+ 1);
293 ptr
= (*pbh
)->b_data
+ *offset
;
298 static void segsum_skip(struct super_block
*sb
, struct buffer_head
**pbh
,
299 unsigned int *offset
, unsigned int bytes
,
302 unsigned int rest_item_in_current_block
303 = ((*pbh
)->b_size
- *offset
) / bytes
;
305 if (count
<= rest_item_in_current_block
) {
306 *offset
+= bytes
* count
;
308 sector_t blocknr
= (*pbh
)->b_blocknr
;
309 unsigned int nitem_per_block
= (*pbh
)->b_size
/ bytes
;
312 count
-= rest_item_in_current_block
;
313 bcnt
= DIV_ROUND_UP(count
, nitem_per_block
);
314 *offset
= bytes
* (count
- (bcnt
- 1) * nitem_per_block
);
317 *pbh
= sb_bread(sb
, blocknr
+ bcnt
);
322 collect_blocks_from_segsum(struct nilfs_sb_info
*sbi
, sector_t sum_blocknr
,
323 struct nilfs_segsum_info
*ssi
,
324 struct list_head
*head
)
326 struct buffer_head
*bh
;
328 unsigned long nfinfo
= ssi
->nfinfo
;
329 sector_t blocknr
= sum_blocknr
+ ssi
->nsumblk
;
336 bh
= sb_bread(sbi
->s_super
, sum_blocknr
);
340 offset
= le16_to_cpu(
341 ((struct nilfs_segment_summary
*)bh
->b_data
)->ss_bytes
);
343 unsigned long nblocks
, ndatablk
, nnodeblk
;
344 struct nilfs_finfo
*finfo
;
346 finfo
= segsum_get(sbi
->s_super
, &bh
, &offset
, sizeof(*finfo
));
347 if (unlikely(!finfo
))
350 ino
= le64_to_cpu(finfo
->fi_ino
);
351 nblocks
= le32_to_cpu(finfo
->fi_nblocks
);
352 ndatablk
= le32_to_cpu(finfo
->fi_ndatablk
);
353 nnodeblk
= nblocks
- ndatablk
;
355 while (ndatablk
-- > 0) {
356 struct nilfs_recovery_block
*rb
;
357 struct nilfs_binfo_v
*binfo
;
359 binfo
= segsum_get(sbi
->s_super
, &bh
, &offset
,
361 if (unlikely(!binfo
))
364 rb
= kmalloc(sizeof(*rb
), GFP_NOFS
);
370 rb
->blocknr
= blocknr
++;
371 rb
->vblocknr
= le64_to_cpu(binfo
->bi_vblocknr
);
372 rb
->blkoff
= le64_to_cpu(binfo
->bi_blkoff
);
373 /* INIT_LIST_HEAD(&rb->list); */
374 list_add_tail(&rb
->list
, head
);
378 blocknr
+= nnodeblk
; /* always 0 for the data sync segments */
379 segsum_skip(sbi
->s_super
, &bh
, &offset
, sizeof(__le64
),
386 brelse(bh
); /* brelse(NULL) is just ignored */
390 static void dispose_recovery_list(struct list_head
*head
)
392 while (!list_empty(head
)) {
393 struct nilfs_recovery_block
*rb
394 = list_entry(head
->next
,
395 struct nilfs_recovery_block
, list
);
401 void nilfs_dispose_segment_list(struct list_head
*head
)
403 while (!list_empty(head
)) {
404 struct nilfs_segment_entry
*ent
405 = list_entry(head
->next
,
406 struct nilfs_segment_entry
, list
);
407 list_del(&ent
->list
);
408 nilfs_free_segment_entry(ent
);
412 static int nilfs_prepare_segment_for_recovery(struct the_nilfs
*nilfs
,
413 struct nilfs_recovery_info
*ri
)
415 struct list_head
*head
= &ri
->ri_used_segments
;
416 struct nilfs_segment_entry
*ent
, *n
;
417 struct inode
*sufile
= nilfs
->ns_sufile
;
422 segnum
[0] = nilfs
->ns_segnum
;
423 segnum
[1] = nilfs
->ns_nextnum
;
424 segnum
[2] = ri
->ri_segnum
;
425 segnum
[3] = ri
->ri_nextnum
;
428 * Releasing the next segment of the latest super root.
429 * The next segment is invalidated by this recovery.
431 err
= nilfs_sufile_free(sufile
, segnum
[1]);
436 for (i
= 1; i
< 4; i
++) {
437 ent
= nilfs_alloc_segment_entry(segnum
[i
]);
440 list_add_tail(&ent
->list
, head
);
444 * Collecting segments written after the latest super root.
445 * These are marked volatile active, and won't be reallocated in
446 * the next construction.
448 list_for_each_entry_safe(ent
, n
, head
, list
) {
449 if (ent
->segnum
== segnum
[0]) {
450 list_del(&ent
->list
);
451 nilfs_free_segment_entry(ent
);
454 err
= nilfs_open_segment_entry(ent
, sufile
);
457 if (nilfs_segment_usage_clean(ent
->raw_su
)) {
458 nilfs_segment_usage_set_volatile_active(ent
->raw_su
);
461 /* Removing duplicated entries */
462 list_del(&ent
->list
);
463 nilfs_close_segment_entry(ent
, sufile
);
464 nilfs_free_segment_entry(ent
);
467 list_splice_init(head
, nilfs
->ns_used_segments
.prev
);
470 * The segment having the latest super root is active, and
471 * should be deactivated on the next construction for recovery.
474 ent
= nilfs_alloc_segment_entry(segnum
[0]);
477 list_add_tail(&ent
->list
, &ri
->ri_used_segments
);
479 /* Allocate new segments for recovery */
480 err
= nilfs_sufile_alloc(sufile
, &segnum
[0]);
484 nilfs
->ns_pseg_offset
= 0;
485 nilfs
->ns_seg_seq
= ri
->ri_seq
+ 2;
486 nilfs
->ns_nextnum
= nilfs
->ns_segnum
= segnum
[0];
490 /* No need to recover sufile because it will be destroyed on error */
494 static int nilfs_recovery_copy_block(struct nilfs_sb_info
*sbi
,
495 struct nilfs_recovery_block
*rb
,
498 struct buffer_head
*bh_org
;
501 bh_org
= sb_bread(sbi
->s_super
, rb
->blocknr
);
502 if (unlikely(!bh_org
))
505 kaddr
= kmap_atomic(page
, KM_USER0
);
506 memcpy(kaddr
+ bh_offset(bh_org
), bh_org
->b_data
, bh_org
->b_size
);
507 kunmap_atomic(kaddr
, KM_USER0
);
512 static int recover_dsync_blocks(struct nilfs_sb_info
*sbi
,
513 struct list_head
*head
,
514 unsigned long *nr_salvaged_blocks
)
517 struct nilfs_recovery_block
*rb
, *n
;
518 unsigned blocksize
= sbi
->s_super
->s_blocksize
;
521 int err
= 0, err2
= 0;
523 list_for_each_entry_safe(rb
, n
, head
, list
) {
524 inode
= nilfs_iget(sbi
->s_super
, rb
->ino
);
526 err
= PTR_ERR(inode
);
531 pos
= rb
->blkoff
<< inode
->i_blkbits
;
533 err
= block_write_begin(NULL
, inode
->i_mapping
, pos
, blocksize
,
534 0, &page
, NULL
, nilfs_get_block
);
538 err
= nilfs_recovery_copy_block(sbi
, rb
, page
);
542 err
= nilfs_set_file_dirty(sbi
, inode
, 1);
546 block_write_end(NULL
, inode
->i_mapping
, pos
, blocksize
,
547 blocksize
, page
, NULL
);
550 page_cache_release(page
);
552 (*nr_salvaged_blocks
)++;
557 page_cache_release(page
);
561 "NILFS warning: error recovering data block "
562 "(err=%d, ino=%lu, block-offset=%llu)\n",
563 err
, rb
->ino
, (unsigned long long)rb
->blkoff
);
567 iput(inode
); /* iput(NULL) is just ignored */
568 list_del_init(&rb
->list
);
575 * nilfs_do_roll_forward - salvage logical segments newer than the latest
577 * @sbi: nilfs_sb_info
579 * @ri: pointer to a nilfs_recovery_info
581 static int nilfs_do_roll_forward(struct the_nilfs
*nilfs
,
582 struct nilfs_sb_info
*sbi
,
583 struct nilfs_recovery_info
*ri
)
585 struct nilfs_segsum_info ssi
;
587 sector_t seg_start
, seg_end
; /* Starting/ending DBN of full segment */
588 unsigned long nsalvaged_blocks
= 0;
590 __u64 segnum
, nextnum
= 0;
593 LIST_HEAD(dsync_blocks
); /* list of data blocks to be recovered */
596 RF_DSYNC_ST
, /* scanning data-sync segments */
598 int state
= RF_INIT_ST
;
600 nilfs_attach_writer(nilfs
, sbi
);
601 pseg_start
= ri
->ri_lsegs_start
;
602 seg_seq
= ri
->ri_lsegs_start_seq
;
603 segnum
= nilfs_get_segnum_of_block(nilfs
, pseg_start
);
604 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
606 while (segnum
!= ri
->ri_segnum
|| pseg_start
<= ri
->ri_pseg_start
) {
608 ret
= load_segment_summary(sbi
, pseg_start
, seg_seq
, &ssi
, 1);
610 if (ret
== NILFS_SEG_FAIL_IO
) {
616 if (unlikely(NILFS_SEG_HAS_SR(&ssi
)))
619 /* Found a valid partial segment; do recovery actions */
620 nextnum
= nilfs_get_segnum_of_block(nilfs
, ssi
.next
);
622 nilfs
->ns_ctime
= ssi
.ctime
;
623 if (!(ssi
.flags
& NILFS_SS_GC
))
624 nilfs
->ns_nongc_ctime
= ssi
.ctime
;
628 if (!NILFS_SEG_LOGBGN(&ssi
) || !NILFS_SEG_DSYNC(&ssi
))
633 if (!NILFS_SEG_DSYNC(&ssi
))
636 err
= collect_blocks_from_segsum(
637 sbi
, pseg_start
, &ssi
, &dsync_blocks
);
640 if (NILFS_SEG_LOGEND(&ssi
)) {
641 err
= recover_dsync_blocks(
642 sbi
, &dsync_blocks
, &nsalvaged_blocks
);
647 break; /* Fall through to try_next_pseg */
651 if (pseg_start
== ri
->ri_lsegs_end
)
653 pseg_start
+= ssi
.nblocks
;
654 if (pseg_start
< seg_end
)
659 if (pseg_start
== ri
->ri_lsegs_end
)
663 /* Looking to the next full segment */
668 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
669 pseg_start
= seg_start
;
672 if (nsalvaged_blocks
) {
673 printk(KERN_INFO
"NILFS (device %s): salvaged %lu blocks\n",
674 sbi
->s_super
->s_id
, nsalvaged_blocks
);
675 ri
->ri_need_recovery
= NILFS_RECOVERY_ROLLFORWARD_DONE
;
678 dispose_recovery_list(&dsync_blocks
);
679 nilfs_detach_writer(sbi
->s_nilfs
, sbi
);
686 "NILFS (device %s): Error roll-forwarding "
687 "(err=%d, pseg block=%llu). ",
688 sbi
->s_super
->s_id
, err
, (unsigned long long)pseg_start
);
692 static void nilfs_finish_roll_forward(struct the_nilfs
*nilfs
,
693 struct nilfs_sb_info
*sbi
,
694 struct nilfs_recovery_info
*ri
)
696 struct buffer_head
*bh
;
699 if (nilfs_get_segnum_of_block(nilfs
, ri
->ri_lsegs_start
) !=
700 nilfs_get_segnum_of_block(nilfs
, ri
->ri_super_root
))
703 bh
= sb_getblk(sbi
->s_super
, ri
->ri_lsegs_start
);
705 memset(bh
->b_data
, 0, bh
->b_size
);
706 set_buffer_dirty(bh
);
707 err
= sync_dirty_buffer(bh
);
710 "NILFS warning: buffer sync write failed during "
711 "post-cleaning of recovery.\n");
716 * nilfs_recover_logical_segments - salvage logical segments written after
717 * the latest super root
719 * @sbi: nilfs_sb_info
720 * @ri: pointer to a nilfs_recovery_info struct to store search results.
722 * Return Value: On success, 0 is returned. On error, one of the following
723 * negative error code is returned.
725 * %-EINVAL - Inconsistent filesystem state.
729 * %-ENOSPC - No space left on device (only in a panic state).
731 * %-ERESTARTSYS - Interrupted.
733 * %-ENOMEM - Insufficient memory available.
735 int nilfs_recover_logical_segments(struct the_nilfs
*nilfs
,
736 struct nilfs_sb_info
*sbi
,
737 struct nilfs_recovery_info
*ri
)
741 if (ri
->ri_lsegs_start
== 0 || ri
->ri_lsegs_end
== 0)
744 err
= nilfs_attach_checkpoint(sbi
, ri
->ri_cno
);
747 "NILFS: error loading the latest checkpoint.\n");
751 err
= nilfs_do_roll_forward(nilfs
, sbi
, ri
);
755 if (ri
->ri_need_recovery
== NILFS_RECOVERY_ROLLFORWARD_DONE
) {
756 err
= nilfs_prepare_segment_for_recovery(nilfs
, ri
);
758 printk(KERN_ERR
"NILFS: Error preparing segments for "
763 err
= nilfs_attach_segment_constructor(sbi
, ri
);
767 set_nilfs_discontinued(nilfs
);
768 err
= nilfs_construct_segment(sbi
->s_super
);
769 nilfs_detach_segment_constructor(sbi
);
772 printk(KERN_ERR
"NILFS: Oops! recovery failed. "
777 nilfs_finish_roll_forward(nilfs
, sbi
, ri
);
780 nilfs_detach_checkpoint(sbi
);
784 nilfs_detach_checkpoint(sbi
);
785 nilfs_mdt_clear(nilfs
->ns_cpfile
);
786 nilfs_mdt_clear(nilfs
->ns_sufile
);
787 nilfs_mdt_clear(nilfs
->ns_dat
);
792 * nilfs_search_super_root - search the latest valid super root
794 * @sbi: nilfs_sb_info
795 * @ri: pointer to a nilfs_recovery_info struct to store search results.
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.
801 * Return Value: On success, 0 is returned. On error, one of the following
802 * negative error code is returned.
804 * %-EINVAL - No valid segment found
808 int nilfs_search_super_root(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
,
809 struct nilfs_recovery_info
*ri
)
811 struct nilfs_segsum_info ssi
;
812 sector_t pseg_start
, pseg_end
, sr_pseg_start
= 0;
813 sector_t seg_start
, seg_end
; /* range of full segment (block number) */
815 __u64 segnum
, nextnum
= 0;
817 struct nilfs_segment_entry
*ent
;
819 int empty_seg
= 0, scan_newer
= 0;
822 pseg_start
= nilfs
->ns_last_pseg
;
823 seg_seq
= nilfs
->ns_last_seq
;
824 cno
= nilfs
->ns_last_cno
;
825 segnum
= nilfs_get_segnum_of_block(nilfs
, pseg_start
);
827 /* Calculate range of segment */
828 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
831 /* Load segment summary */
832 ret
= load_segment_summary(sbi
, pseg_start
, seg_seq
, &ssi
, 1);
834 if (ret
== NILFS_SEG_FAIL_IO
)
838 pseg_end
= pseg_start
+ ssi
.nblocks
- 1;
839 if (unlikely(pseg_end
> seg_end
)) {
840 ret
= NILFS_SEG_FAIL_CONSISTENCY
;
844 /* A valid partial segment */
845 ri
->ri_pseg_start
= pseg_start
;
846 ri
->ri_seq
= seg_seq
;
847 ri
->ri_segnum
= segnum
;
848 nextnum
= nilfs_get_segnum_of_block(nilfs
, ssi
.next
);
849 ri
->ri_nextnum
= nextnum
;
852 if (!NILFS_SEG_HAS_SR(&ssi
)) {
854 /* This will never happen because a superblock
855 (last_segment) always points to a pseg
856 having a super root. */
857 ret
= NILFS_SEG_FAIL_CONSISTENCY
;
860 if (!ri
->ri_lsegs_start
&& NILFS_SEG_LOGBGN(&ssi
)) {
861 ri
->ri_lsegs_start
= pseg_start
;
862 ri
->ri_lsegs_start_seq
= seg_seq
;
864 if (NILFS_SEG_LOGEND(&ssi
))
865 ri
->ri_lsegs_end
= pseg_start
;
869 /* A valid super root was found. */
871 ri
->ri_super_root
= pseg_end
;
872 ri
->ri_lsegs_start
= ri
->ri_lsegs_end
= 0;
874 nilfs_dispose_segment_list(&segments
);
875 nilfs
->ns_pseg_offset
= (sr_pseg_start
= pseg_start
)
876 + ssi
.nblocks
- seg_start
;
877 nilfs
->ns_seg_seq
= seg_seq
;
878 nilfs
->ns_segnum
= segnum
;
879 nilfs
->ns_cno
= cno
; /* nilfs->ns_cno = ri->ri_cno + 1 */
880 nilfs
->ns_ctime
= ssi
.ctime
;
881 nilfs
->ns_nextnum
= nextnum
;
884 ri
->ri_need_recovery
= NILFS_RECOVERY_SR_UPDATED
;
885 else if (nilfs
->ns_mount_state
& NILFS_VALID_FS
)
886 goto super_root_found
;
890 /* reset region for roll-forward */
891 pseg_start
+= ssi
.nblocks
;
892 if (pseg_start
< seg_end
)
897 /* Standing on a course, or met an inconsistent state */
898 pseg_start
+= ssi
.nblocks
;
899 if (pseg_start
< seg_end
)
907 * This can happen if a checkpoint was written without
908 * barriers, or as a result of an I/O failure.
913 /* Looking to the next full segment */
915 goto super_root_found
; /* found a valid super root */
917 ent
= nilfs_alloc_segment_entry(segnum
);
918 if (unlikely(!ent
)) {
922 list_add_tail(&ent
->list
, &segments
);
926 nilfs_get_segment_range(nilfs
, segnum
, &seg_start
, &seg_end
);
927 pseg_start
= seg_start
;
931 /* Updating pointers relating to the latest checkpoint */
932 list_splice(&segments
, ri
->ri_used_segments
.prev
);
933 nilfs
->ns_last_pseg
= sr_pseg_start
;
934 nilfs
->ns_last_seq
= nilfs
->ns_seg_seq
;
935 nilfs
->ns_last_cno
= ri
->ri_cno
;
939 nilfs_dispose_segment_list(&segments
);
940 return (ret
< 0) ? ret
: nilfs_warn_segment_error(ret
);