path: root/fs/btrfs/extent_map.c
diff options
authorJosef Bacik <jbacik@fusionio.com>2013-01-28 09:45:20 -0500
committerJosef Bacik <jbacik@fusionio.com>2013-02-05 16:09:03 -0500
commit222c81dc3874b4fe98371be665d0447a36447653 (patch)
tree534dba9dae10fa3b8cdc4111176b3ec7450e922b /fs/btrfs/extent_map.c
parent1eafa6c73791e4f312324ddad9cbcaf6a1b6052b (diff)
Btrfs: do not merge logged extents if we've removed them from the tree
You can run into this problem where if somebody is fsyncing and writing out the existing extents you will have removed the extent map from the em tree, but it's still valid for the current fsync so we go ahead and write it. The problem is we unconditionally try to merge it back into the em tree, but if we've removed it from the em tree that will cause use after free problems. Fix this to only merge if we are still a part of the tree. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/extent_map.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index ed88f5ee4be..9759911dd34 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -289,7 +289,8 @@ out:
void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
- try_merge_map(tree, em);
+ if (em->in_tree)
+ try_merge_map(tree, em);