btrfslabel.c

   1 /*
   2  * Copyright (C) 2008 Morey Roof.   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 #define _GNU_SOURCE
  20
  21 #ifndef __CHECKER__
  22 #include <sys/ioctl.h>
  23 #include <sys/mount.h>
  24 #include "ioctl.h"
  25 #endif /* __CHECKER__ */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <dirent.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34 #include <linux/fs.h>
  35 #include <linux/limits.h>
  36 #include <ctype.h>
  37 #include "kerncompat.h"
  38 #include "ctree.h"
  39 #include "utils.h"
  40 #include "version.h"
  41 #include "disk-io.h"
  42 #include "transaction.h"
  43
  44 #define MOUNTED                        1
  45 #define UNMOUNTED                      2
  46 #define GET_LABEL                      3
  47 #define SET_LABEL                      4
  48
  49 static void change_label_unmounted(char *dev, char *nLabel)
  50 {
  51        struct btrfs_root *root;
  52        struct btrfs_trans_handle *trans;
  53
  54        /* Open the super_block at the default location
  55         * and as read-write.
  56         */
  57        root = open_ctree(dev, 0, 1);
  58
  59        trans = btrfs_start_transaction(root, 1);
  60        strncpy(root->fs_info->super_copy.label, nLabel, BTRFS_LABEL_SIZE);
  61        btrfs_commit_transaction(trans, root);
  62
  63        /* Now we close it since we are done. */
  64        close_ctree(root);
  65 }
  66
  67 static void get_label_unmounted(char *dev)
  68 {
  69        struct btrfs_root *root;
  70
  71        /* Open the super_block at the default location
  72         * and as read-only.
  73         */
  74        root = open_ctree(dev, 0, 0);
  75
  76        fprintf(stdout, "%s\n", root->fs_info->super_copy.label);
  77
  78        /* Now we close it since we are done. */
  79        close_ctree(root);
  80 }
  81
  82 int get_label(char *btrfs_dev)
  83 {
  84
  85         int ret;
  86         ret = check_mounted(btrfs_dev);
  87         if (ret < 0)
  88         {
  89                fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev);
  90                return -1;
  91         }
  92
  93         if(ret != 0)
  94         {
  95                fprintf(stderr, "FATAL: the filesystem has to be unmounted\n");
  96                return -2;
  97         }
  98         get_label_unmounted(btrfs_dev);
  99         return 0;
 100 }
 101
 102
 103 int set_label(char *btrfs_dev, char *nLabel)
 104 {
 105
 106         int ret;
 107         ret = check_mounted(btrfs_dev);
 108         if (ret < 0)
 109         {
 110                fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev);
 111                return -1;
 112         }
 113
 114         if(ret != 0)
 115         {
 116                fprintf(stderr, "FATAL: the filesystem has to be unmounted\n");
 117                return -2;
 118         }
 119         change_label_unmounted(btrfs_dev, nLabel);
 120         return 0;
 121 }