dm crypt: leverage immutable biovecs when decrypting on read
Commit 003b5c571 ("block: Convert drivers to immutable biovecs")
stopped short of changing dm-crypt to leverage the fact that the biovec
array of a bio will no longer be modified.
Switch to using bio_clone_fast() when cloning bios for decryption after
read.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ea09d54..aa1238f 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1124,15 +1124,15 @@
static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
{
struct crypt_config *cc = io->cc;
- struct bio *base_bio = io->base_bio;
struct bio *clone;
/*
- * The block layer might modify the bvec array, so always
- * copy the required bvecs because we need the original
- * one in order to decrypt the whole bio data *afterwards*.
+ * We need the original biovec array in order to decrypt
+ * the whole bio data *afterwards* -- thanks to immutable
+ * biovecs we don't need to worry about the block layer
+ * modifying the biovec array; so leverage bio_clone_fast().
*/
- clone = bio_clone_bioset(base_bio, gfp, cc->bs);
+ clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
if (!clone)
return 1;