Btrfs: Bring back mount -o ssd optimizations

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 26185d46712c..4890151cd68d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1103,4 +1103,6 @@ int btrfs_read_buffer(struct extent_buffer *buf)
 static struct extent_io_ops btree_extent_io_ops = {
         .writepage_io_hook = btree_writepage_io_hook,
         .submit_bio_hook = btree_submit_bio_hook,
+        /* note we're sharing with inode.c for the merge bio hook */
+        .merge_bio_hook = btrfs_merge_bio_hook,
 };