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 static 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                 fprintf(stderr, "Warning: Seeding flag cleared.\n");
  60         }
  61
  62         trans = btrfs_start_transaction(root, 1);
  63         btrfs_set_super_flags(disk_super, super_flags);
  64         btrfs_commit_transaction(trans, root);
  65
  66         return 0;
  67 }
  68
  69 static int enable_extrefs_flag(struct btrfs_root *root)
  70 {
  71         struct btrfs_trans_handle *trans;
  72         struct btrfs_super_block *disk_super;
  73         u64 super_flags;
  74
  75         disk_super = root->fs_info->super_copy;
  76         super_flags = btrfs_super_incompat_flags(disk_super);
  77         super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
  78         trans = btrfs_start_transaction(root, 1);
  79         btrfs_set_super_incompat_flags(disk_super, super_flags);
  80         btrfs_commit_transaction(trans, root);
  81
  82         return 0;
  83 }
  84
  85 static int enable_skinny_metadata(struct btrfs_root *root)
  86 {
  87         struct btrfs_trans_handle *trans;
  88         struct btrfs_super_block *disk_super;
  89         u64 super_flags;
  90
  91         disk_super = root->fs_info->super_copy;
  92         super_flags = btrfs_super_incompat_flags(disk_super);
  93         super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
  94         trans = btrfs_start_transaction(root, 1);
  95         btrfs_set_super_incompat_flags(disk_super, super_flags);
  96         btrfs_commit_transaction(trans, root);
  97
  98         return 0;
  99 }
 100
 101 static void print_usage(void)
 102 {
 103         fprintf(stderr, "usage: btrfstune [options] device\n");
 104         fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
 105         fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
 106         fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
 107         fprintf(stderr, "\t-f \t\tforce to clear flags, make sure that you are aware of the dangers\n");
 108 }
 109
 110 int main(int argc, char *argv[])
 111 {
 112         struct btrfs_root *root;
 113         int success = 0;
 114         int extrefs_flag = 0;
 115         int seeding_flag = 0;
 116         u64 seeding_value = 0;
 117         int skinny_flag = 0;
 118         int force = 0;
 119         int ret;
 120
 121         optind = 1;
 122         while(1) {
 123                 int c = getopt(argc, argv, "S:rxf");
 124                 if (c < 0)
 125                         break;
 126                 switch(c) {
 127                 case 'S':
 128                         seeding_flag = 1;
 129                         seeding_value = arg_strtou64(optarg);
 130                         break;
 131                 case 'r':
 132                         extrefs_flag = 1;
 133                         break;
 134                 case 'x':
 135                         skinny_flag = 1;
 136                         break;
 137                 case 'f':
 138                         force = 1;
 139                         break;
 140                 default:
 141                         print_usage();
 142                         return 1;
 143                 }
 144         }
 145
 146         set_argv0(argv);
 147         argc = argc - optind;
 148         device = argv[optind];
 149         if (check_argc_exact(argc, 1)) {
 150                 print_usage();
 151                 return 1;
 152         }
 153
 154         if (!(seeding_flag + extrefs_flag + skinny_flag)) {
 155                 fprintf(stderr,
 156                         "ERROR: At least one option should be assigned.\n");
 157                 print_usage();
 158                 return 1;
 159         }
 160
 161         ret = check_mounted(device);
 162         if (ret < 0) {
 163                 fprintf(stderr, "Could not check mount status: %s\n",
 164                         strerror(-ret));
 165                 return 1;
 166         } else if (ret) {
 167                 fprintf(stderr, "%s is mounted\n", device);
 168                 return 1;
 169         }
 170
 171         root = open_ctree(device, 0, OPEN_CTREE_WRITES);
 172
 173         if (!root) {
 174                 fprintf(stderr, "Open ctree failed\n");
 175                 return 1;
 176         }
 177
 178         if (seeding_flag) {
 179                 if (!seeding_value && !force) {
 180                         fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
 181                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 182                         if (!ret) {
 183                                 fprintf(stderr, "Clear seeding flag canceled\n");
 184                                 return 1;
 185                         }
 186                 }
 187
 188                 ret = update_seeding_flag(root, seeding_value);
 189                 if (!ret)
 190                         success++;
 191         }
 192
 193         if (extrefs_flag) {
 194                 enable_extrefs_flag(root);
 195                 success++;
 196         }
 197
 198         if (skinny_flag) {
 199                 enable_skinny_metadata(root);
 200                 success++;
 201         }
 202
 203         if (success > 0) {
 204                 ret = 0;
 205         } else {
 206                 root->fs_info->readonly = 1;
 207                 ret = 1;
 208                 fprintf(stderr, "btrfstune failed\n");
 209         }
 210         close_ctree(root);
 211
 212         return ret;
 213 }