From 5be76758f35ec6578e5b9b150aa513ac26bd9c54 Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.cz>
Date: Thu, 9 Jun 2011 10:02:51 +0000
Subject: [PATCH] btrfs: fix unlocked access of delalloc_inodes

list_splice_init will make delalloc_inodes empty, but without a spinlock
around, this may produce corrupted list head, accessed in many placess,
The race window is very tight and nobody seems to have hit it so far.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
 fs/btrfs/disk-io.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a203d363184de..33b744a5ac031 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2911,9 +2911,8 @@ static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
 
 	INIT_LIST_HEAD(&splice);
 
-	list_splice_init(&root->fs_info->delalloc_inodes, &splice);
-
 	spin_lock(&root->fs_info->delalloc_lock);
+	list_splice_init(&root->fs_info->delalloc_inodes, &splice);
 
 	while (!list_empty(&splice)) {
 		btrfs_inode = list_entry(splice.next, struct btrfs_inode,
-- 
2.39.5