This is a note to let you know that I've just added the patch titled
Btrfs: fix lock leak when resuming snapshot deletion
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-fix-lock-leak-when-resuming-snapshot-deletion.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fec386ac1428f9c0e672df952cbca5cebd4e4e2f Mon Sep 17 00:00:00 2001
From: Josef Bacik <jbacik@xxxxxxxxxxxx>
Date: Mon, 15 Jul 2013 12:41:42 -0400
Subject: Btrfs: fix lock leak when resuming snapshot deletion
From: Josef Bacik <jbacik@xxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxx>
Signed-off-by: Josef Bacik <jbacik@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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--;
}
Patches currently in stable-queue which might be from jbacik@xxxxxxxxxxxx are
queue-3.4/btrfs-fix-lock-leak-when-resuming-snapshot-deletion.patch
queue-3.4/btrfs-re-add-root-to-dead-root-list-if-we-stop-dropping-it.patch
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