Add support for defragging files via btrfsctl -d. Avoid OOM on extent tree

defrag.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 89e282c35ce2..b41f48ade419 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -217,6 +217,9 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        root->fs_info->generation);
                 WARN_ON(1);
         }
+        if (buffer_defrag_done(parent))
+                return 0;
+
         parent_node = btrfs_buffer_node(parent);
         parent_nritems = btrfs_header_nritems(&parent_node->header);
         parent_level = btrfs_header_level(&parent_node->header);
@@ -274,6 +277,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                 *last_ret = search_start;
                 if (parent_level == 1)
                         clear_buffer_defrag(tmp_bh);
+                set_buffer_defrag_done(tmp_bh);
                 brelse(tmp_bh);
         }
         return err;