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>
This commit is contained in:
parent
e3bb2e30d5
commit
3f943d853d
|
@ -167,7 +167,6 @@ xlog_bread_noalign(
|
|||
|
||||
ASSERT(nbblks > 0);
|
||||
ASSERT(BBTOB(nbblks) <= XFS_BUF_SIZE(bp));
|
||||
ASSERT(bp);
|
||||
|
||||
XFS_BUF_SET_ADDR(bp, log->l_logBBstart + blk_no);
|
||||
XFS_BUF_READ(bp);
|
||||
|
@ -380,14 +379,12 @@ xlog_find_cycle_start(
|
|||
}
|
||||
|
||||
/*
|
||||
* Check that the range of blocks does not contain the cycle number
|
||||
* given. The scan needs to occur from front to back and the ptr into the
|
||||
* region must be updated since a later routine will need to perform another
|
||||
* test. If the region is completely good, we end up returning the same
|
||||
* last block number.
|
||||
*
|
||||
* Set blkno to -1 if we encounter no errors. This is an invalid block number
|
||||
* since we don't ever expect logs to get this large.
|
||||
* Check that a range of blocks does not contain stop_on_cycle_no.
|
||||
* Fill in *new_blk with the block offset where such a block is
|
||||
* found, or with -1 (an invalid block number) if there is no such
|
||||
* block in the range. The scan needs to occur from front to back
|
||||
* and the pointer into the region must be updated since a later
|
||||
* routine will need to perform another test.
|
||||
*/
|
||||
STATIC int
|
||||
xlog_find_verify_cycle(
|
||||
|
@ -661,7 +658,7 @@ xlog_find_head(
|
|||
* In this case we want to find the first block with cycle
|
||||
* number matching last_half_cycle. We expect the log to be
|
||||
* some variation on
|
||||
* x + 1 ... | x ...
|
||||
* x + 1 ... | x ... | x
|
||||
* The first block with cycle number x (last_half_cycle) will
|
||||
* be where the new head belongs. First we do a binary search
|
||||
* for the first occurrence of last_half_cycle. The binary
|
||||
|
@ -671,11 +668,13 @@ xlog_find_head(
|
|||
* the log, then we look for occurrences of last_half_cycle - 1
|
||||
* at the end of the log. The cases we're looking for look
|
||||
* like
|
||||
* x + 1 ... | x | x + 1 | x ...
|
||||
* ^ binary search stopped here
|
||||
* v binary search stopped here
|
||||
* x + 1 ... | x | x + 1 | x ... | x
|
||||
* ^ but we want to locate this spot
|
||||
* or
|
||||
* x + 1 ... | x ... | x - 1 | x
|
||||
* <---------> less than scan distance
|
||||
* x + 1 ... | x ... | x - 1 | x
|
||||
* ^ we want to locate this spot
|
||||
*/
|
||||
stop_on_cycle = last_half_cycle;
|
||||
if ((error = xlog_find_cycle_start(log, bp, first_blk,
|
||||
|
@ -731,9 +730,9 @@ xlog_find_head(
|
|||
* certainly not the head of the log. By searching for
|
||||
* last_half_cycle-1 we accomplish that.
|
||||
*/
|
||||
start_blk = log_bbnum - num_scan_bblks + head_blk;
|
||||
ASSERT(head_blk <= INT_MAX &&
|
||||
(xfs_daddr_t) num_scan_bblks - head_blk >= 0);
|
||||
(xfs_daddr_t) num_scan_bblks >= head_blk);
|
||||
start_blk = log_bbnum - (num_scan_bblks - head_blk);
|
||||
if ((error = xlog_find_verify_cycle(log, start_blk,
|
||||
num_scan_bblks - (int)head_blk,
|
||||
(stop_on_cycle - 1), &new_blk)))
|
||||
|
@ -780,7 +779,7 @@ validate_head:
|
|||
if ((error = xlog_find_verify_log_record(log, start_blk,
|
||||
&head_blk, 0)) == -1) {
|
||||
/* We hit the beginning of the log during our search */
|
||||
start_blk = log_bbnum - num_scan_bblks + head_blk;
|
||||
start_blk = log_bbnum - (num_scan_bblks - head_blk);
|
||||
new_blk = log_bbnum;
|
||||
ASSERT(start_blk <= INT_MAX &&
|
||||
(xfs_daddr_t) log_bbnum-start_blk >= 0);
|
||||
|
|
Loading…
Reference in New Issue