btrfs-progs: add crude error handling when transaction start fails
[platform/upstream/btrfs-progs.git] / btrfs-zero-log.c
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include "kerncompat.h"
20
21 #include <stdio.h>
22 #include <unistd.h>
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "transaction.h"
26 #include "utils.h"
27 #include "help.h"
28
29 __attribute__((noreturn)) static void print_usage(void)
30 {
31         printf("usage: btrfs-zero-log dev\n");
32         exit(1);
33 }
34
35 int main(int argc, char **argv)
36 {
37         struct btrfs_root *root;
38         struct btrfs_trans_handle *trans;
39         struct btrfs_super_block *sb;
40         int ret;
41
42         set_argv0(argv);
43         if (check_argc_exact(argc - optind, 1))
44                 print_usage();
45
46         radix_tree_init();
47
48         printf("WARNING: this utility is deprecated, please use 'btrfs rescue zero-log'\n\n");
49
50         if ((ret = check_mounted(argv[optind])) < 0) {
51                 fprintf(stderr, "ERROR: could not check mount status: %s\n", strerror(-ret));
52                 goto out;
53         } else if (ret) {
54                 fprintf(stderr, "ERROR: %s is currently mounted\n", argv[optind]);
55                 ret = -EBUSY;
56                 goto out;
57         }
58
59         root = open_ctree(argv[optind], 0, OPEN_CTREE_WRITES | OPEN_CTREE_PARTIAL);
60         if (!root) {
61                 fprintf(stderr, "ERROR: cannot open ctree\n");
62                 return 1;
63         }
64
65         sb = root->fs_info->super_copy;
66         printf("Clearing log on %s, previous log_root %llu, level %u\n",
67                         argv[optind],
68                         (unsigned long long)btrfs_super_log_root(sb),
69                         (unsigned)btrfs_super_log_root_level(sb));
70         trans = btrfs_start_transaction(root, 1);
71         BUG_ON(IS_ERR(trans));
72         btrfs_set_super_log_root(root->fs_info->super_copy, 0);
73         btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
74         btrfs_commit_transaction(trans, root);
75         close_ctree(root);
76 out:
77         return !!ret;
78 }