diff options
| author |   Shaohua Li <shli@kernel.org> | 2012-12-14 11:15:36 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2012-12-14 20:46:04 +0100 |
| commit | 8dd2cb7e880d2f77fba53b523c99133ad5054cfd (patch) | |
| tree | ea51e89f8c8bf9ca8e888d68ecf6732a52e8e99d /include | |
| parent | deadline: Allow 0ms deadline latency, increase the read speed (diff) | |
| download | linux-dev-8dd2cb7e880d2f77fba53b523c99133ad5054cfd.tar.xz linux-dev-8dd2cb7e880d2f77fba53b523c99133ad5054cfd.zip | |
block: discard granularity might not be power of 2
In MD raid case, discard granularity might not be power of 2, for example, a
4-disk raid5 has 3*chunk_size discard granularity. Correct the calculation for
such cases.
Reported-by: Neil Brown <neilb@suse.de>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c9d233e727f2..acb4f7bbbd32 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1188,13 +1188,14 @@ static inline int queue_discard_alignment(struct request_queue *q) static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector) { - unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1); + sector_t alignment = sector << 9; + alignment = sector_div(alignment, lim->discard_granularity); if (!lim->max_discard_sectors) return 0; - return (lim->discard_granularity + lim->discard_alignment - alignment) - & (lim->discard_granularity - 1); + alignment = lim->discard_granularity + lim->discard_alignment - alignment; + return sector_div(alignment, lim->discard_granularity); } static inline int bdev_discard_alignment(struct block_device *bdev) |