diff options
| author | Junichi Nomura <j-nomura@ce.jp.nec.com> | 2014-10-03 11:55:16 +0000 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-10-05 20:03:34 -0400 |
| commit | 997782735c0f1e2e069337129fe0d5738d83d19b (patch) | |
| tree | 981b35bf9ae43c10ddb668eb254827b3ad775e04 /drivers/md | |
| parent | d8f429e1669b9709f5b669aac9d734dbe0640891 (diff) | |
dm: remove nr_iovecs parameter from alloc_tio()
alloc_tio() uses bio_alloc_bioset() to allocate a clone-bio for a bio.
alloc_tio() takes the number of bvecs to allocate for the clone-bio.
However, with v3.14's immutable biovec changes DM now uses
__bio_clone_fast() and no longer needs to allocate bvecs.
In practice, the 'nr_iovecs' passed to alloc_tio() is always effectively
0. __clone_and_map_simple_bio() looked like it was passing non-zero
nr_iovecs, but its value was always within the range of inline bvecs and
no allocation actually happened. If allocation happened, the BUG_ON() in
__bio_clone_fast() would've triggered.
Remove the nr_iovecs parameter from alloc_tio() to prevent possible
future bio_alloc_bioset() mis-use of a new bioset interface that will no
longer allow bvecs to be allocated.
Also fix extra whitespace before the __bio_clone_fast() call in
__clone_and_map_simple_bio().
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 32b958dbc499..0b9de07d585b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1249,13 +1249,13 @@ static void clone_bio(struct dm_target_io *tio, struct bio *bio, } static struct dm_target_io *alloc_tio(struct clone_info *ci, - struct dm_target *ti, int nr_iovecs, + struct dm_target *ti, unsigned target_bio_nr) { struct dm_target_io *tio; struct bio *clone; - clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, ci->md->bs); + clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs); tio = container_of(clone, struct dm_target_io, clone); tio->io = ci->io; @@ -1269,17 +1269,12 @@ static void __clone_and_map_simple_bio(struct clone_info *ci, struct dm_target *ti, unsigned target_bio_nr, unsigned *len) { - struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs, target_bio_nr); + struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr); struct bio *clone = &tio->clone; tio->len_ptr = len; - /* - * Discard requests require the bio's inline iovecs be initialized. - * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush - * and discard, so no need for concern about wasted bvec allocations. - */ - __bio_clone_fast(clone, ci->bio); + __bio_clone_fast(clone, ci->bio); if (len) bio_setup_sector(clone, ci->sector, *len); @@ -1322,7 +1317,7 @@ static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti num_target_bios = ti->num_write_bios(ti, bio); for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) { - tio = alloc_tio(ci, ti, 0, target_bio_nr); + tio = alloc_tio(ci, ti, target_bio_nr); tio->len_ptr = len; clone_bio(tio, bio, sector, *len); __map_bio(tio); |