From fec386ac1428f9c0e672df952cbca5cebd4e4e2f Mon Sep 17 00:00:00 2001
From: Josef Bacik <jbacik@fusionio.com>
Date: Mon, 15 Jul 2013 12:41:42 -0400
Subject: [PATCH] Btrfs: fix lock leak when resuming snapshot deletion
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,
Cc: stable@vger.kernel.org
Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
fs/btrfs/extent-tree.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a429704dd95f..e814b1312511 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7523,6 +7523,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
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,
@@ -7538,6 +7539,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
break;
btrfs_tree_unlock(path->nodes[level]);
+ path->locks[level] = 0;
WARN_ON(wc->refs[level] != 1);
level--;
}
--
2.20.1