From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Lyakas , Josef Bacik Subject: [ 17/39] Btrfs: fix lock leak when resuming snapshot deletion Date: Fri, 2 Aug 2013 18:18:27 +0800 Message-Id: <20130802101459.260385063@linuxfoundation.org> In-Reply-To: <20130802101456.800497005@linuxfoundation.org> References: <20130802101456.800497005@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik commit fec386ac1428f9c0e672df952cbca5cebd4e4e2f upstream. We aren't setting path->locks[level] when we resume a snapshot deletion which means we won't unlock the buffer when we free the path. This causes deadlocks if we happen to re-allocate the block before we've evicted the extent buffer from cache. Thanks, Reported-by: Alex Lyakas Signed-off-by: Josef Bacik Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6903,6 +6903,7 @@ int btrfs_drop_snapshot(struct btrfs_roo while (1) { btrfs_tree_lock(path->nodes[level]); btrfs_set_lock_blocking(path->nodes[level]); + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; ret = btrfs_lookup_extent_info(trans, root, path->nodes[level]->start, @@ -6919,6 +6920,7 @@ int btrfs_drop_snapshot(struct btrfs_roo break; btrfs_tree_unlock(path->nodes[level]); + path->locks[level] = 0; WARN_ON(wc->refs[level] != 1); level--; }