lkml.org 
[lkml]   [2013]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[ 17/39] Btrfs: fix lock leak when resuming snapshot deletion
Date
3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Josef Bacik <jbacik@fusionio.com>

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 <alex.btrfs@zadarastorage.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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--;
}



\
 
 \ /
  Last update: 2013-08-02 14:01    [W:0.173 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site