Btrfs: don't bother kicking async if there's nothing to reclaim

We do this check when we start the async reclaimer thread, might as well check
before we kick it off to save us some cycles.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a012fd49f214fbaf5f4d8fbece60e17a1a39e801..a0ca2b5914d06c79b1697547ef42df9c07592e04 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4944,6 +4944,9 @@ static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
        if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
                return 0;
 
+       if (!btrfs_calc_reclaim_metadata_size(fs_info->fs_root, space_info))
+               return 0;
+
        return (used >= thresh && !btrfs_fs_closing(fs_info) &&
                !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
 }