[PATCH] Btrfs: fix extent state leak from tree log

[PATCH] Btrfs: fix extent state leak from tree log

[Liu Bo]

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.

cc: <stable@vger.kernel.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/tree-log.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 22046ed..a7e6235 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3049,13 +3049,14 @@ 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,
 				NULL);
 		if (ret)
 			break;
 
 		clear_extent_bits(&log->dirty_log_pages, start, end,
-				  EXTENT_DIRTY | EXTENT_NEW);
+				  EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
 	}
 
 	/*
-- 
2.9.4

Re: [PATCH] Btrfs: fix extent state leak from tree log

[Josef Bacik]

On Thu, Jan 25, 2018 at 11:02:52AM -0700, Liu Bo wrote:
> 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.
> 
> cc: <stable@vger.kernel.org>
> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>

Reviewed-by: Josef Bacik <jbacik@fb.com>

Thanks,

Josef