Btrfs: fix extent state leak from tree log

commit 55237a5f2431a72435e3ed39e4306e973c0446b7 upstream.

It's possible that btrfs_sync_log() bails out after one of the two
btrfs_write_marked_extents() which convert extent state's state bit into
EXTENT_NEED_WAIT from EXTENT_DIRTY/EXTENT_NEW, however only EXTENT_DIRTY
and EXTENT_NEW are searched by free_log_tree() so that those extent states
with EXTENT_NEED_WAIT lead to memory leak.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 6479b85..998a9cb 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2216,12 +2216,13 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
 
        while (1) {
                ret = find_first_extent_bit(&log->dirty_log_pages,
-                               0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
+                               0, &start, &end,
+                               EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
                if (ret)
                        break;
 
                clear_extent_bits(&log->dirty_log_pages, start, end,
-                                 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
+                                 EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT, GFP_NOFS);
        }
 
        free_extent_buffer(log->node);