diff options
| author | Alex Elder <aelder@sgi.com> | 2010-04-15 18:17:30 (GMT) |
|---|---|---|
| committer | Alex Elder <aelder@sgi.com> | 2010-05-19 14:58:14 (GMT) |
| commit | e3bb2e30d532b00a9bdda997e174a9f9916cb1c0 (patch) | |
| tree | 33d82124eb213877450072f6fa1df6dbf05be7bf | |
| parent | 9db127edb54048707eb84517eb0573e597a2370a (diff) | |
| download | linux-e3bb2e30d532b00a9bdda997e174a9f9916cb1c0.tar.xz | |
xfs: avoid repeated pointer dereferences
In xlog_find_cycle_start() use a local variable for some repeated
operations rather than constantly accessing the memory location
whose address is passed in.
(This version drops an assertion that a pointer is non-null.)
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | fs/xfs/xfs_log_recover.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index a6cbc14..7b3375d 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -354,26 +354,27 @@ xlog_find_cycle_start( { xfs_caddr_t offset; xfs_daddr_t mid_blk; + xfs_daddr_t end_blk; uint mid_cycle; int error; - mid_blk = BLK_AVG(first_blk, *last_blk); - while (mid_blk != first_blk && mid_blk != *last_blk) { + end_blk = *last_blk; + mid_blk = BLK_AVG(first_blk, end_blk); + while (mid_blk != first_blk && mid_blk != end_blk) { error = xlog_bread(log, mid_blk, 1, bp, &offset); if (error) return error; mid_cycle = xlog_get_cycle(offset); - if (mid_cycle == cycle) { - *last_blk = mid_blk; - /* last_half_cycle == mid_cycle */ - } else { - first_blk = mid_blk; - /* first_half_cycle == mid_cycle */ - } - mid_blk = BLK_AVG(first_blk, *last_blk); + if (mid_cycle == cycle) + end_blk = mid_blk; /* last_half_cycle == mid_cycle */ + else + first_blk = mid_blk; /* first_half_cycle == mid_cycle */ + mid_blk = BLK_AVG(first_blk, end_blk); } - ASSERT((mid_blk == first_blk && mid_blk+1 == *last_blk) || - (mid_blk == *last_blk && mid_blk-1 == first_blk)); + ASSERT((mid_blk == first_blk && mid_blk+1 == end_blk) || + (mid_blk == end_blk && mid_blk-1 == first_blk)); + + *last_blk = end_blk; return 0; } |