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 /block | |
| parent | 75274551c81796b636c5acb0c2597dec7ec2e6c4 (diff) | |
| download | lwn-8dd2cb7e880d2f77fba53b523c99133ad5054cfd.tar.gz lwn-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 'block')
| -rw-r--r-- | block/blk-lib.c | 23 | ||||
| -rw-r--r-- | block/blk-settings.c | 6 |
2 files changed, 16 insertions, 13 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index 9373b58dfab1..5677fd33d7d2 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -43,8 +43,8 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, DECLARE_COMPLETION_ONSTACK(wait); struct request_queue *q = bdev_get_queue(bdev); int type = REQ_WRITE | REQ_DISCARD; - unsigned int max_discard_sectors; - unsigned int granularity, alignment, mask; + sector_t max_discard_sectors; + sector_t granularity, alignment; struct bio_batch bb; struct bio *bio; int ret = 0; @@ -57,15 +57,16 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, /* Zero-sector (unknown) and one-sector granularities are the same. */ granularity = max(q->limits.discard_granularity >> 9, 1U); - mask = granularity - 1; - alignment = (bdev_discard_alignment(bdev) >> 9) & mask; + alignment = bdev_discard_alignment(bdev) >> 9; + alignment = sector_div(alignment, granularity); /* * Ensure that max_discard_sectors is of the proper * granularity, so that requests stay aligned after a split. */ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); - max_discard_sectors = round_down(max_discard_sectors, granularity); + sector_div(max_discard_sectors, granularity); + max_discard_sectors *= granularity; if (unlikely(!max_discard_sectors)) { /* Avoid infinite loop below. Being cautious never hurts. */ return -EOPNOTSUPP; @@ -83,7 +84,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, while (nr_sects) { unsigned int req_sects; - sector_t end_sect; + sector_t end_sect, tmp; bio = bio_alloc(gfp_mask, 1); if (!bio) { @@ -98,10 +99,12 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, * misaligned, stop the discard at the previous aligned sector. */ end_sect = sector + req_sects; - if (req_sects < nr_sects && (end_sect & mask) != alignment) { - end_sect = - round_down(end_sect - alignment, granularity) - + alignment; + tmp = end_sect; + if (req_sects < nr_sects && + sector_div(tmp, granularity) != alignment) { + end_sect = end_sect - alignment; + sector_div(end_sect, granularity); + end_sect = end_sect * granularity + alignment; req_sects = end_sect - sector; } diff --git a/block/blk-settings.c b/block/blk-settings.c index 779bb7646bcd..c50ecf0ea3b1 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -611,7 +611,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, bottom = b->discard_granularity + alignment; /* Verify that top and bottom intervals line up */ - if (max(top, bottom) & (min(top, bottom) - 1)) + if ((max(top, bottom) % min(top, bottom)) != 0) t->discard_misaligned = 1; } @@ -619,8 +619,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, b->max_discard_sectors); t->discard_granularity = max(t->discard_granularity, b->discard_granularity); - t->discard_alignment = lcm(t->discard_alignment, alignment) & - (t->discard_granularity - 1); + t->discard_alignment = lcm(t->discard_alignment, alignment) % + t->discard_granularity; } return ret; |