fs/btrfs/volumes.c:

fs/btrfs/volumes.c

@@ -2183,9 +2183,17 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 	synchronize_rcu();
 	btrfs_free_device(device);
 
+	/*
+	 * This can happen if cur_devices is the private seed devices list.  We
+	 * cannot call close_fs_devices() here because it expects the uuid_mutex
+	 * to be held, but in fact we don't need that for the private
+	 * seed_devices, we can simply decrement cur_devices->opened and then
+	 * remove it from our list and free the fs_devices.
+	 */
 	if (cur_devices->open_devices == 0) {
+		ASSERT(cur_devices->opened == 1);
 		list_del_init(&cur_devices->seed_list);
-		close_fs_devices(cur_devices);
+		cur_devices->opened--;
 		free_fs_devices(cur_devices);
 	}