Btrfs: fix unprotected alloc list insertion during the finishing procedure of replace

the alloc list of the filesystem is protected by ->chunk_mutex, we need
get that mutex when we insert the new device into the list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 564c92638b20a8d4929a920eb843c4f4fe71745b..b20d59e5e5dd4ffa1db428e81320c46099f72ea9 100644 (file)
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -484,6 +484,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
        WARN_ON(ret);
 
        /* keep away write_all_supers() during the finishing procedure */
+       mutex_lock(&root->fs_info->chunk_mutex);
        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
        btrfs_dev_replace_lock(dev_replace);
        dev_replace->replace_state =
@@ -503,6 +504,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
                              rcu_str_deref(tgt_device->name), scrub_ret);
                btrfs_dev_replace_unlock(dev_replace);
                mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+               mutex_unlock(&root->fs_info->chunk_mutex);
                if (tgt_device)
                        btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
                mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
@@ -543,6 +545,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
         */
        btrfs_dev_replace_unlock(dev_replace);
        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+       mutex_unlock(&root->fs_info->chunk_mutex);
 
        /* write back the superblocks */
        trans = btrfs_start_transaction(root, 0);