btrfstune.c

   1 /*
   2  * Copyright (C) 2008 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 #define _XOPEN_SOURCE 500
  20 #define _GNU_SOURCE 1
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <unistd.h>
  27 #include <dirent.h>
  28 #include "kerncompat.h"
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "utils.h"
  33 #include "version.h"
  34
  35 static char *device;
  36
  37 int update_seeding_flag(struct btrfs_root *root, int set_flag)
  38 {
  39         struct btrfs_trans_handle *trans;
  40         struct btrfs_super_block *disk_super;
  41         u64 super_flags;
  42
  43         disk_super = &root->fs_info->super_copy;
  44         super_flags = btrfs_super_flags(disk_super);
  45         if (set_flag) {
  46                 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
  47                         fprintf(stderr, "seeding flag is already set on %s\n",
  48                                 device);
  49                         return 1;
  50                 }
  51                 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
  52         } else {
  53                 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
  54                         fprintf(stderr, "seeding flag is not set on %s\n",
  55                                 device);
  56                         return 1;
  57                 }
  58                 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
  59         }
  60
  61         trans = btrfs_start_transaction(root, 1);
  62         btrfs_set_super_flags(disk_super, super_flags);
  63         btrfs_commit_transaction(trans, root);
  64
  65         return 0;
  66 }
  67
  68 static void print_usage(void)
  69 {
  70         fprintf(stderr, "usage: btrfstune [options] device\n");
  71         fprintf(stderr, "\t-S value\tenable/disable seeding\n");
  72 }
  73
  74 int main(int argc, char *argv[])
  75 {
  76         struct btrfs_root *root;
  77         int success = 0;
  78         int seeding_flag = 0;
  79         int seeding_value = 0;
  80         int ret;
  81
  82         while(1) {
  83                 int c = getopt(argc, argv, "S:");
  84                 if (c < 0)
  85                         break;
  86                 switch(c) {
  87                 case 'S':
  88                         seeding_flag = 1;
  89                         seeding_value = atoi(optarg);
  90                         break;
  91                 default:
  92                         print_usage();
  93                         return 1;
  94                 }
  95         }
  96
  97         argc = argc - optind;
  98         device = argv[optind];
  99         if (argc != 1) {
 100                 print_usage();
 101                 return 1;
 102         }
 103
 104         if (check_mounted(device)) {
 105                 fprintf(stderr, "%s is mounted\n", device);
 106                 return 1;
 107         }
 108
 109         root = open_ctree(device, 0, 1);
 110
 111         if (seeding_flag) {
 112                 ret = update_seeding_flag(root, seeding_value);
 113                 if (!ret)
 114                         success++;
 115         }
 116
 117         if (success > 0) {
 118                 ret = 0;
 119         } else {
 120                 root->fs_info->readonly = 1;
 121                 ret = 1;
 122         }
 123         close_ctree(root);
 124
 125         return ret;
 126 }