Btrfs: enable discard support

The discard support code in btrfs currently is guarded by ifdefs for
BIO_RW_DISCARD, which is never defines as it's the name of an enum
memeber.  Just remove the useless ifdefs to actually enable the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index bf7782fc5939..d4a35283d99e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1568,18 +1568,15 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-#ifdef BIO_RW_DISCARD
 static void btrfs_issue_discard(struct block_device *bdev,
                                 u64 start, u64 len)
 {
         blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
 }
-#endif
 
 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
                                 u64 num_bytes)
 {
-#ifdef BIO_RW_DISCARD
         int ret;
         u64 map_length = num_bytes;
         struct btrfs_multi_bio *multi = NULL;
@@ -1606,9 +1603,6 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
         }
 
         return ret;
-#else
-        return 0;
-#endif
 }
 
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,