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| author | Mikulas Patocka <mpatocka@redhat.com> | 2014-03-28 20:51:55 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-08-01 18:30:34 +0200 |
| commit | 6a2414836154dc22b224c837ad7b862f78d595d1 (patch) | |
| tree | 35affb2fa0fa07f9d0639f7e884e00ba2e237faf /block | |
| parent | dm table: make dm_table_supports_discards static (diff) | |
| download | linux-6a2414836154dc22b224c837ad7b862f78d595d1.tar.xz linux-6a2414836154dc22b224c837ad7b862f78d595d1.zip | |
block: use kmalloc alignment for bio slab
Various subsystems can ask the bio subsystem to create a bio slab cache
with some free space before the bio. This free space can be used for any
purpose. Device mapper uses this per-bio-data feature to place some
target-specific and device-mapper specific data before the bio, so that
the target-specific data doesn't have to be allocated separately.
This per-bio-data mechanism is used in place of kmalloc, so we need the
allocated slab to have the same memory alignment as memory allocated
with kmalloc.
Change bio_find_or_create_slab() so that it uses ARCH_KMALLOC_MINALIGN
alignment when creating the slab cache. This is needed so that dm-crypt
can use per-bio-data for encryption - the crypto subsystem assumes this
data will have the same alignment as kmalloc'ed memory.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bio.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/bio.c b/block/bio.c index 0ec61c9e536c..3e6331d25d90 100644 --- a/block/bio.c +++ b/block/bio.c @@ -112,7 +112,8 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) bslab = &bio_slabs[entry]; snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); - slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); + slab = kmem_cache_create(bslab->name, sz, ARCH_KMALLOC_MINALIGN, + SLAB_HWCACHE_ALIGN, NULL); if (!slab) goto out_unlock; |