Josef Bacik
2013-Jan-31 15:30 UTC
[PATCH] Btrfs: remove extent mapping if we fail to add chunk
I got a double free error when unmounting a file system that failed to add a chunk during its operation. This is because we will kfree the mapping that we created but leave the extent_map in the em_tree for chunks. So to fix this just remove the extent_map when we error out so we don''t run into this problem. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> --- fs/btrfs/volumes.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 2ba5b84..4f3f152 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3762,9 +3762,10 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); - free_extent_map(em); - if (ret) + if (ret) { + free_extent_map(em); goto error; + } for (i = 0; i < map->num_stripes; ++i) { struct btrfs_device *device; @@ -3804,6 +3805,14 @@ error_dev_extent: break; } } + write_lock(&em_tree->lock); + remove_extent_mapping(em_tree, em); + write_unlock(&em_tree->lock); + + /* One for our allocation */ + free_extent_map(em); + /* One for the tree reference */ + free_extent_map(em); error: kfree(map); kfree(devices_info); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html