btrfs: Allow to specify compress method when defrag

Update defrag ioctl, so one can choose lzo or zlib when turning
on compression in defrag operation.

Changelog:

v1 -> v2
- Add incompability flag.
- Fix to check invalid compress type.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index c344d12c646b..24d0f4628240 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -133,8 +133,15 @@ struct btrfs_ioctl_defrag_range_args {
          */
         __u32 extent_thresh;
 
+        /*
+         * which compression method to use if turning on compression
+         * for this defrag operation.  If unspecified, zlib will
+         * be used
+         */
+        __u32 compress_type;
+
         /* spare for later */
-        __u32 unused[5];
+        __u32 unused[4];
 };
 
 struct btrfs_ioctl_space_info {