From: Liu Bo <bo.li.liu@oracle.com>
Date: Tue, 4 Apr 2017 12:23:25 -0700
Subject: [PATCH] Btrfs: use bio_clone_fast to clone our bio
Git-commit: 015c1bd9f162a00934dd71859f36b12d03c8e771
Patch-Mainline: v4.13-rc1
References: FATE#323952, FATE#322506

For raid1 and raid10, we clone the original bio to the bios which are then
sent to different disks.

Right now we use bio_clone_bioset to create a clone bio with iterating
bi_io_vec to initialize it.  This changes it to use bio_clone_fast()
which creates a clone bio but only copies the bi_io_vec pointer
instead of iterating bi_io_vec.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Hannes Reinecke <hare@suse.de>
---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0180571..33cc67e 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2716,7 +2716,7 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
 	struct btrfs_io_bio *btrfs_bio;
 	struct bio *new;
 
-	new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset);
+	new = bio_clone_fast(bio, gfp_mask, btrfs_bioset);
 	if (new) {
 		btrfs_bio = btrfs_io_bio(new);
 		btrfs_bio->csum = NULL;
-- 
1.8.5.6