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        if (!root) /* errors are printed by open_ctree() */
  59          return;
  60
  61        trans = btrfs_start_transaction(root, 1);
  62        strncpy(root->fs_info->super_copy.label, nLabel, BTRFS_LABEL_SIZE);
  63        root->fs_info->super_copy.label[BTRFS_LABEL_SIZE-1] = 0;
  64        btrfs_commit_transaction(trans, root);
  65
  66        /* Now we close it since we are done. */
  67        close_ctree(root);
  68 }
  69
  70 static void get_label_unmounted(char *dev)
  71 {
  72        struct btrfs_root *root;
  73
  74        /* Open the super_block at the default location
  75         * and as read-only.
  76         */
  77        root = open_ctree(dev, 0, 0);
  78
  79        fprintf(stdout, "%s\n", root->fs_info->super_copy.label);
  80
  81        /* Now we close it since we are done. */
  82        close_ctree(root);
  83 }
  84
  85 int get_label(char *btrfs_dev)
  86 {
  87
  88         int ret;
  89         ret = check_mounted(btrfs_dev);
  90         if (ret < 0)
  91         {
  92                fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev);
  93                return -1;
  94         }
  95
  96         if(ret != 0)
  97         {
  98                fprintf(stderr, "FATAL: the filesystem has to be unmounted\n");
  99                return -2;
 100         }
 101         get_label_unmounted(btrfs_dev);
 102         return 0;
 103 }
 104
 105
 106 int set_label(char *btrfs_dev, char *nLabel)
 107 {
 108
 109         int ret;
 110         ret = check_mounted(btrfs_dev);
 111         if (ret < 0)
 112         {
 113                fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev);
 114                return -1;
 115         }
 116
 117         if(ret != 0)
 118         {
 119                fprintf(stderr, "FATAL: the filesystem has to be unmounted\n");
 120                return -2;
 121         }
 122         change_label_unmounted(btrfs_dev, nLabel);
 123         return 0;
 124 }