dm: use bio_clone_fast in alloc_io/alloc_tio

Replace open coded bio_clone_fast implementations with the actual helper.
Note that the bio allocated as part of the dm_io structure in alloc_io
will only actually be used later in alloc_tio, making this earlier
cloning of the information safe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 0f87961..862564a 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -520,7 +520,7 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
        struct dm_target_io *tio;
        struct bio *clone;
 
-       clone = bio_alloc_bioset(NULL, 0, 0, GFP_NOIO, &md->io_bs);
+       clone = bio_clone_fast(bio, GFP_NOIO, &md->io_bs);
 
        tio = clone_to_tio(clone);
        tio->inside_dm_io = true;
@@ -553,8 +553,8 @@ static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti,
                /* the dm_target_io embedded in ci->io is available */
                tio = &ci->io->tio;
        } else {
-               struct bio *clone = bio_alloc_bioset(NULL, 0, 0, gfp_mask,
-                                                    &ci->io->md->bs);
+               struct bio *clone = bio_clone_fast(ci->bio, gfp_mask,
+                                                  &ci->io->md->bs);
                if (!clone)
                        return NULL;
 
@@ -562,12 +562,6 @@ static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti,
                tio->inside_dm_io = false;
        }
 
-       if (__bio_clone_fast(&tio->clone, ci->bio, gfp_mask) < 0) {
-               if (ci->io->tio.io)
-                       bio_put(&tio->clone);
-               return NULL;
-       }
-
        tio->magic = DM_TIO_MAGIC;
        tio->io = ci->io;
        tio->ti = ti;