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| author | Mikulas Patocka <mpatocka@redhat.com> | 2018-04-19 08:33:00 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2018-04-30 11:51:39 -0400 |
| commit | f7879b4cea4b7867e7382efdbd805fbe35835337 (patch) | |
| tree | bb6b18ca48bde0f32f82b38ed28e8126f24ae755 | |
| parent | fc8cec113904a47396bf0a1afc62920d66319d36 (diff) | |
| download | linux-f7879b4cea4b7867e7382efdbd805fbe35835337.tar.bz2 | |
dm bufio: fix buffer alignment
Commit 6b5e718cc138 ("dm bufio: relax alignment constraint on slab
cache") relaxed alignment on dm-bufio cache, however it may break
dm-crypt or dm-integrity.
dm-crypt and dm-integrity require that the size of bio vector entries
(bv_len) is aligned on its sector size. bv_offset doesn't have to be
aligned, but bv_len must be. XFS sends unaligned bios, but they do not
cross page boundary, so the requirement for aligned bv_len is met.
Commit 6b5e718cc138 made dm-bufio send unaligned bios that cross page
boundary, this could break dm-crypt and dm-integrity.
Reinstates the alignment. Note that misaligned entries only happen when
we use slab/slub debugging. Without debugging, the entries are always
aligned.
Fixes: 6b5e718cc138 ("dm bufio: relax alignment constraint on slab cache")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-bufio.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 12aa9ca21d8c..dc385b70e4c3 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1681,8 +1681,9 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign if (block_size <= KMALLOC_MAX_SIZE && (block_size < PAGE_SIZE || !is_power_of_2(block_size))) { - snprintf(slab_name, sizeof slab_name, "dm_bufio_cache-%u", c->block_size); - c->slab_cache = kmem_cache_create(slab_name, c->block_size, ARCH_KMALLOC_MINALIGN, + unsigned align = min(1U << __ffs(block_size), (unsigned)PAGE_SIZE); + snprintf(slab_name, sizeof slab_name, "dm_bufio_cache-%u", block_size); + c->slab_cache = kmem_cache_create(slab_name, block_size, align, SLAB_RECLAIM_ACCOUNT, NULL); if (!c->slab_cache) { r = -ENOMEM; |