diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 29fc8a09dd2e..fc9a3d8f6238 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -857,6 +857,35 @@ static noinline struct btrfs_device *device_list_add(const char *path, return ERR_PTR(-EEXIST); } + /* + * We are going to replace the device path for a given devid, + * make sure it's the same device if the device is mounted + */ + if (device->bdev) { + struct block_device *path_bdev; + + path_bdev = lookup_bdev(path); + if (IS_ERR(path_bdev)) { + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_CAST(path_bdev); + } + + if (device->bdev != path_bdev) { + bdput(path_bdev); + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_warn_in_rcu(device->fs_info, + "duplicate device fsid:devid for %pU:%llu old:%s new:%s", + disk_super->fsid, devid, + rcu_str_deref(device->name), path); + return ERR_PTR(-EEXIST); + } + bdput(path_bdev); + btrfs_info_in_rcu(device->fs_info, + "device fsid %pU devid %llu moved old:%s new:%s", + disk_super->fsid, devid, + rcu_str_deref(device->name), path); + } + name = rcu_string_strdup(path, GFP_NOFS); if (!name) { mutex_unlock(&fs_devices->device_list_mutex);