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| author | Mike Snitzer <snitzer@redhat.com> | 2014-10-08 18:26:13 -0400 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2014-11-17 14:11:44 +0000 |
| commit | 4296b616583a4cb1d4d1d38e2ddb982738a4b446 (patch) | |
| tree | e23ded30b4c3e3b3625619b432f1759800d03680 /block | |
| parent | 51edc20fc062b2f4c1782059d7f742880fd4f06e (diff) | |
| download | linux-stable-4296b616583a4cb1d4d1d38e2ddb982738a4b446.tar.gz linux-stable-4296b616583a4cb1d4d1d38e2ddb982738a4b446.tar.bz2 linux-stable-4296b616583a4cb1d4d1d38e2ddb982738a4b446.zip | |
block: fix alignment_offset math that assumes io_min is a power-of-2
commit b8839b8c55f3fdd60dc36abcda7e0266aff7985c upstream.
The math in both blk_stack_limits() and queue_limit_alignment_offset()
assume that a block device's io_min (aka minimum_io_size) is always a
power-of-2. Fix the math such that it works for non-power-of-2 io_min.
This issue (of alignment_offset != 0) became apparent when testing
dm-thinp with a thinp blocksize that matches a RAID6 stripesize of
1280K. Commit fdfb4c8c1 ("dm thin: set minimum_io_size to pool's data
block size") unlocked the potential for alignment_offset != 0 due to
the dm-thin-pool's io_min possibly being a non-power-of-2.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-settings.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index f1a1795a5683..aa02247d227e 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -574,7 +574,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, bottom = max(b->physical_block_size, b->io_min) + alignment; /* Verify that top and bottom intervals line up */ - if (max(top, bottom) & (min(top, bottom) - 1)) { + if (max(top, bottom) % min(top, bottom)) { t->misaligned = 1; ret = -1; } @@ -619,7 +619,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, /* Find lowest common alignment_offset */ t->alignment_offset = lcm(t->alignment_offset, alignment) - & (max(t->physical_block_size, t->io_min) - 1); + % max(t->physical_block_size, t->io_min); /* Verify that new alignment_offset is on a logical block boundary */ if (t->alignment_offset & (t->logical_block_size - 1)) { |