btrfs-progs: Introduce rescue.h to resolve missing-prototypes for chunk and super rescue

We don't have any header declaring btrfs_recover_chunk_tree() nor
btrfs_recover_superblocks(), thus W=1 gives missing-prototypes warning
on them.

Fix it by introducing a new header, rescue.h for these two functions, so
make W=1 could be much happier.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

chunk-recover.c

@@ -40,6 +40,7 @@
 #include "utils.h"
 #include "btrfsck.h"
 #include "commands.h"
+#include "rescue.h"
 
 struct recover_control {
 	int verbose;

cmds-rescue.c

@@ -26,15 +26,13 @@
 #include "commands.h"
 #include "utils.h"
 #include "help.h"
+#include "rescue.h"
 
 static const char * const rescue_cmd_group_usage[] = {
 	"btrfs rescue <command> [options] <path>",
 	NULL
 };
 
-int btrfs_recover_chunk_tree(const char *path, int verbose, int yes);
-int btrfs_recover_superblocks(const char *path, int verbose, int yes);
-
 static const char * const cmd_rescue_chunk_recover_usage[] = {
 	"btrfs rescue chunk-recover [options] <device>",
 	"Recover the chunk tree by scanning the devices one by one.",

rescue.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 SUSE.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef __BTRFS_RESCUE_H__
+#define __BTRFS_RESCUE_H__
+
+int btrfs_recover_superblocks(const char *path, int verbose, int yes);
+int btrfs_recover_chunk_tree(const char *path, int verbose, int yes);
+
+#endif

super-recover.c

@@ -34,6 +34,7 @@
 #include "crc32c.h"
 #include "volumes.h"
 #include "commands.h"
+#include "rescue.h"
 
 struct btrfs_recover_superblock {
 	struct btrfs_fs_devices *fs_devices;