diff options
author | Alex Elder <aelder@sgi.com> | 2010-04-15 14:17:34 -0400 |
---|---|---|
committer | Alex Elder <aelder@sgi.com> | 2010-05-19 10:58:14 -0400 |
commit | 3f943d853d6ce6d808e7362e4444c7ed5f692357 (patch) | |
tree | 78ade96089353117fbcacd2a2e7297af9e652115 /fs/xfs | |
parent | e3bb2e30d532b00a9bdda997e174a9f9916cb1c0 (diff) |
xfs: minor odds and ends in xfs_log_recover.c
Odds and ends in "xfs_log_recover.c". This patch just contains some
minor things that didn't seem to warrant their own individual
patches:
- In xlog_bread_noalign(), drop an assertion that a pointer is
non-null (the crash will tell us it was a bad pointer).
- Add a more descriptive header comment for xlog_find_verify_cycle().
- Make a few additions to the comments in xlog_find_head(). Also
rearrange some expressions in a few spots to produce the same
result, but in a way that seems more clear what's being computed.
(Updated in response to Dave's review comments. Note I did not
split this patch like I said I would.)
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs')
-rw-r--r-- | fs/xfs/xfs_log_recover.c | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 7b3375db6728..3bfff4220a74 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c | |||
@@ -167,7 +167,6 @@ xlog_bread_noalign( | |||
167 | 167 | ||
168 | ASSERT(nbblks > 0); | 168 | ASSERT(nbblks > 0); |
169 | ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); | 169 | ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp)); |
170 | ASSERT(bp); | ||
171 | 170 | ||
172 | XFS_BUF_SET_ADDR(bp, log->l_logBBstart + blk_no); | 171 | XFS_BUF_SET_ADDR(bp, log->l_logBBstart + blk_no); |
173 | XFS_BUF_READ(bp); | 172 | XFS_BUF_READ(bp); |
@@ -380,14 +379,12 @@ xlog_find_cycle_start( | |||
380 | } | 379 | } |
381 | 380 | ||
382 | /* | 381 | /* |
383 | * Check that the range of blocks does not contain the cycle number | 382 | * Check that a range of blocks does not contain stop_on_cycle_no. |
384 | * given. The scan needs to occur from front to back and the ptr into the | 383 | * Fill in *new_blk with the block offset where such a block is |
385 | * region must be updated since a later routine will need to perform another | 384 | * found, or with -1 (an invalid block number) if there is no such |
386 | * test. If the region is completely good, we end up returning the same | 385 | * block in the range. The scan needs to occur from front to back |
387 | * last block number. | 386 | * and the pointer into the region must be updated since a later |
388 | * | 387 | * routine will need to perform another test. |
389 | * Set blkno to -1 if we encounter no errors. This is an invalid block number | ||
390 | * since we don't ever expect logs to get this large. | ||
391 | */ | 388 | */ |
392 | STATIC int | 389 | STATIC int |
393 | xlog_find_verify_cycle( | 390 | xlog_find_verify_cycle( |
@@ -661,7 +658,7 @@ xlog_find_head( | |||
661 | * In this case we want to find the first block with cycle | 658 | * In this case we want to find the first block with cycle |
662 | * number matching last_half_cycle. We expect the log to be | 659 | * number matching last_half_cycle. We expect the log to be |
663 | * some variation on | 660 | * some variation on |
664 | * x + 1 ... | x ... | 661 | * x + 1 ... | x ... | x |
665 | * The first block with cycle number x (last_half_cycle) will | 662 | * The first block with cycle number x (last_half_cycle) will |
666 | * be where the new head belongs. First we do a binary search | 663 | * be where the new head belongs. First we do a binary search |
667 | * for the first occurrence of last_half_cycle. The binary | 664 | * for the first occurrence of last_half_cycle. The binary |
@@ -671,11 +668,13 @@ xlog_find_head( | |||
671 | * the log, then we look for occurrences of last_half_cycle - 1 | 668 | * the log, then we look for occurrences of last_half_cycle - 1 |
672 | * at the end of the log. The cases we're looking for look | 669 | * at the end of the log. The cases we're looking for look |
673 | * like | 670 | * like |
674 | * x + 1 ... | x | x + 1 | x ... | 671 | * v binary search stopped here |
675 | * ^ binary search stopped here | 672 | * x + 1 ... | x | x + 1 | x ... | x |
673 | * ^ but we want to locate this spot | ||
676 | * or | 674 | * or |
677 | * x + 1 ... | x ... | x - 1 | x | ||
678 | * <---------> less than scan distance | 675 | * <---------> less than scan distance |
676 | * x + 1 ... | x ... | x - 1 | x | ||
677 | * ^ we want to locate this spot | ||
679 | */ | 678 | */ |
680 | stop_on_cycle = last_half_cycle; | 679 | stop_on_cycle = last_half_cycle; |
681 | if ((error = xlog_find_cycle_start(log, bp, first_blk, | 680 | if ((error = xlog_find_cycle_start(log, bp, first_blk, |
@@ -731,9 +730,9 @@ xlog_find_head( | |||
731 | * certainly not the head of the log. By searching for | 730 | * certainly not the head of the log. By searching for |
732 | * last_half_cycle-1 we accomplish that. | 731 | * last_half_cycle-1 we accomplish that. |
733 | */ | 732 | */ |
734 | start_blk = log_bbnum - num_scan_bblks + head_blk; | ||
735 | ASSERT(head_blk <= INT_MAX && | 733 | ASSERT(head_blk <= INT_MAX && |
736 | (xfs_daddr_t) num_scan_bblks - head_blk >= 0); | 734 | (xfs_daddr_t) num_scan_bblks >= head_blk); |
735 | start_blk = log_bbnum - (num_scan_bblks - head_blk); | ||
737 | if ((error = xlog_find_verify_cycle(log, start_blk, | 736 | if ((error = xlog_find_verify_cycle(log, start_blk, |
738 | num_scan_bblks - (int)head_blk, | 737 | num_scan_bblks - (int)head_blk, |
739 | (stop_on_cycle - 1), &new_blk))) | 738 | (stop_on_cycle - 1), &new_blk))) |
@@ -780,7 +779,7 @@ validate_head: | |||
780 | if ((error = xlog_find_verify_log_record(log, start_blk, | 779 | if ((error = xlog_find_verify_log_record(log, start_blk, |
781 | &head_blk, 0)) == -1) { | 780 | &head_blk, 0)) == -1) { |
782 | /* We hit the beginning of the log during our search */ | 781 | /* We hit the beginning of the log during our search */ |
783 | start_blk = log_bbnum - num_scan_bblks + head_blk; | 782 | start_blk = log_bbnum - (num_scan_bblks - head_blk); |
784 | new_blk = log_bbnum; | 783 | new_blk = log_bbnum; |
785 | ASSERT(start_blk <= INT_MAX && | 784 | ASSERT(start_blk <= INT_MAX && |
786 | (xfs_daddr_t) log_bbnum-start_blk >= 0); | 785 | (xfs_daddr_t) log_bbnum-start_blk >= 0); |