[PATCH] Btrfs: correctly flush data on defrag when compression is enabled

[Filipe David Borba Manana <fdmanana@xxxxxxxxx>]

When the defrag flag BTRFS_DEFRAG_RANGE_START_IO is set and compression
enabled, we weren't flushing completely, as writing compressed extents
is a 2 steps process, one to compress the data and another one to write
the compressed data to disk.

Signed-off-by: Filipe David Borba Manana <fdmanana@xxxxxxxxx>
---
 fs/btrfs/ioctl.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d4c1795..f914b5d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1382,8 +1382,12 @@ int btrfs_defrag_file(struct inode *inode, struct file 
*file,
                }
        }
 
-       if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
+       if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
                filemap_flush(inode->i_mapping);
+               if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+                            &BTRFS_I(inode)->runtime_flags))
+                       filemap_flush(inode->i_mapping);
+       }
 
        if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
                /* the filemap_flush will queue IO into the worker threads, but
-- 
1.7.9.5