btrfs: clear defrag status of a root if starting transaction fails

BugLink: https://bugs.launchpad.net/bugs/1938199
commit 6819703f5a365c95488b07066a8744841bf14231 upstream.

The defrag loop processes leaves in batches and starting transaction for
each. The whole defragmentation on a given root is protected by a bit
but in case the transaction fails, the bit is not cleared

In case the transaction fails the bit would prevent starting
defragmentation again, so make sure it's cleared.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index aca6c467d7761c5fa46a78964b0e838d3ab054fd..d8e4e0bf3fc2dc16c6cde9333322d0c3ebaa16b6 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1274,8 +1274,10 @@ int btrfs_defrag_root(struct btrfs_root *root)
 
        while (1) {
                trans = btrfs_start_transaction(root, 0);
-               if (IS_ERR(trans))
-                       return PTR_ERR(trans);
+               if (IS_ERR(trans)) {
+                       ret = PTR_ERR(trans);
+                       break;
+               }
 
                ret = btrfs_defrag_leaves(trans, root);