From 85756620e146b3e48cb3d63baab3ae864cdf936c Mon Sep 17 00:00:00 2001
From: Liu Bo <bo.li.liu@oracle.com>
Date: Wed, 14 Nov 2012 14:35:30 +0000
Subject: [PATCH] --- yaml --- r: 346673 b: refs/heads/master c:
 d25628bdd66aedd6e07729d8dc6c8ee846d66d72 h: refs/heads/master i:   346671:
 ac44d1c308ee6f044a2ceb89551fb62ddedc3fe4 v: v3

---
 [refs]                   | 2 +-
 trunk/fs/btrfs/volumes.c | 9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 5bbe4afe9f40..bc900644b16f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b53d3f5db2b79637acadc06a330db6c2c60863f5
+refs/heads/master: d25628bdd66aedd6e07729d8dc6c8ee846d66d72
diff --git a/trunk/fs/btrfs/volumes.c b/trunk/fs/btrfs/volumes.c
index db79fb7e7e91..92e586bc8004 100644
--- a/trunk/fs/btrfs/volumes.c
+++ b/trunk/fs/btrfs/volumes.c
@@ -1681,16 +1681,17 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	filemap_write_and_wait(bdev->bd_inode->i_mapping);
 
 	devices = &root->fs_info->fs_devices->devices;
-	/*
-	 * we have the volume lock, so we don't need the extra
-	 * device list mutex while reading the list here.
-	 */
+
+	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 	list_for_each_entry(device, devices, dev_list) {
 		if (device->bdev == bdev) {
 			ret = -EEXIST;
+			mutex_unlock(
+				&root->fs_info->fs_devices->device_list_mutex);
 			goto error;
 		}
 	}
+	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 	device = kzalloc(sizeof(*device), GFP_NOFS);
 	if (!device) {