From: Filipe Manana fdmanana@suse.com
[ Upstream commit a7e4c6a3031c74078dba7fa36239d0f4fe476c53 ]
If during the quota disable we fail when cleaning the quota tree or when deleting the root from the root tree, we jump to the 'out' label without ever dropping the reference on the quota root, resulting in a leak of the root since fs_info->quota_root is no longer pointing to the root (we have set it to NULL just before those steps).
Fix this by always doing a btrfs_put_root() call under the 'out' label. This is a problem that exists since qgroups were first added in 2012 by commit bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but back then we missed a kfree on the quota root and free_extent_buffer() calls on its root and commit root nodes, since back then roots were not yet reference counted.
Reviewed-by: Boris Burkov boris@bur.io Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/qgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 50669ff9346c6..83d17f22335b1 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1197,7 +1197,7 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
int btrfs_quota_disable(struct btrfs_fs_info *fs_info) { - struct btrfs_root *quota_root; + struct btrfs_root *quota_root = NULL; struct btrfs_trans_handle *trans = NULL; int ret = 0;
@@ -1290,9 +1290,9 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) btrfs_tree_unlock(quota_root->node); btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
- btrfs_put_root(quota_root);
out: + btrfs_put_root(quota_root); mutex_unlock(&fs_info->qgroup_ioctl_lock); if (ret && trans) btrfs_end_transaction(trans);