btrfs-progs/btrfs-zero-log.c

/*
 * Copyright (C) 2007 Oracle.  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.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include "kerncompat.h"

#include <stdio.h>
#include <unistd.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "utils.h"

__attribute__((noreturn)) static void print_usage(void)
{
	printf("usage: btrfs-zero-log dev\n");
	exit(1);
}

int main(int argc, char **argv)
{
	struct btrfs_root *root;
	struct btrfs_trans_handle *trans;
	struct btrfs_super_block *sb;
	int ret;

	set_argv0(argv);
	if (check_argc_exact(argc - optind, 1))
		print_usage();

	radix_tree_init();

	printf("WARNING: this utility is deprecated, please use 'btrfs rescue zero-log'\n\n");

	if ((ret = check_mounted(argv[optind])) < 0) {
		fprintf(stderr, "ERROR: could not check mount status: %s\n", strerror(-ret));
		goto out;
	} else if (ret) {
		fprintf(stderr, "ERROR: %s is currently mounted\n", argv[optind]);
		ret = -EBUSY;
		goto out;
	}

	root = open_ctree(argv[optind], 0, OPEN_CTREE_WRITES | OPEN_CTREE_PARTIAL);
	if (!root) {
		fprintf(stderr, "ERROR: cannot open ctree\n");
		return 1;
	}

	sb = root->fs_info->super_copy;
	printf("Clearing log on %s, previous log_root %llu, level %u\n",
			argv[optind],
			(unsigned long long)btrfs_super_log_root(sb),
			(unsigned)btrfs_super_log_root_level(sb));
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_super_log_root(root->fs_info->super_copy, 0);
	btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
	btrfs_commit_transaction(trans, root);
	close_ctree(root);
out:
	return !!ret;
}