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 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <dirent.h>
  26 #include "kerncompat.h"
  27 #include "ctree.h"
  28 #include "disk-io.h"
  29 #include "transaction.h"
  30 #include "utils.h"
  31
  32 static char *device;
  33 static int force = 0;
  34
  35 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
  36 {
  37         struct btrfs_trans_handle *trans;
  38         struct btrfs_super_block *disk_super;
  39         u64 super_flags;
  40
  41         disk_super = root->fs_info->super_copy;
  42         super_flags = btrfs_super_flags(disk_super);
  43         if (set_flag) {
  44                 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
  45                         if (force)
  46                                 return 0;
  47                         else
  48                                 fprintf(stderr, "seeding flag is already set on %s\n", 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 int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
 102 {
 103         struct btrfs_fs_info *fs_info = root->fs_info;
 104         int same_fsid = 1;
 105         int same_chunk_tree_uuid = 1;
 106         int ret;
 107
 108         /* Check for whether we need to change fs/chunk id */
 109         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 110                 return 0;
 111         if (fs_info->new_fsid)
 112                 same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
 113                                           btrfs_header_fsid(), BTRFS_FSID_SIZE);
 114         if (fs_info->new_chunk_tree_uuid)
 115                 same_chunk_tree_uuid =
 116                         !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 117                                               btrfs_header_chunk_tree_uuid(eb),
 118                                               BTRFS_UUID_SIZE);
 119         if (same_fsid && same_chunk_tree_uuid)
 120                 return 0;
 121         if (!same_fsid)
 122                 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
 123                                     BTRFS_FSID_SIZE);
 124         if (!same_chunk_tree_uuid)
 125                 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 126                                     btrfs_header_chunk_tree_uuid(eb),
 127                                     BTRFS_UUID_SIZE);
 128         ret = write_tree_block(NULL, root, eb);
 129
 130         return ret;
 131 }
 132
 133 static void print_usage(void)
 134 {
 135         fprintf(stderr, "usage: btrfstune [options] device\n");
 136         fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
 137         fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
 138         fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
 139         fprintf(stderr, "\t-f \t\tforce to set or clear flags, make sure that you are aware of the dangers\n");
 140 }
 141
 142 int main(int argc, char *argv[])
 143 {
 144         struct btrfs_root *root;
 145         int success = 0;
 146         int total = 0;
 147         int extrefs_flag = 0;
 148         int seeding_flag = 0;
 149         u64 seeding_value = 0;
 150         int skinny_flag = 0;
 151         int ret;
 152
 153         optind = 1;
 154         while(1) {
 155                 int c = getopt(argc, argv, "S:rxf");
 156                 if (c < 0)
 157                         break;
 158                 switch(c) {
 159                 case 'S':
 160                         seeding_flag = 1;
 161                         seeding_value = arg_strtou64(optarg);
 162                         break;
 163                 case 'r':
 164                         extrefs_flag = 1;
 165                         break;
 166                 case 'x':
 167                         skinny_flag = 1;
 168                         break;
 169                 case 'f':
 170                         force = 1;
 171                         break;
 172                 default:
 173                         print_usage();
 174                         return 1;
 175                 }
 176         }
 177
 178         set_argv0(argv);
 179         argc = argc - optind;
 180         device = argv[optind];
 181         if (check_argc_exact(argc, 1)) {
 182                 print_usage();
 183                 return 1;
 184         }
 185
 186         if (!(seeding_flag + extrefs_flag + skinny_flag)) {
 187                 fprintf(stderr,
 188                         "ERROR: At least one option should be assigned.\n");
 189                 print_usage();
 190                 return 1;
 191         }
 192
 193         ret = check_mounted(device);
 194         if (ret < 0) {
 195                 fprintf(stderr, "Could not check mount status: %s\n",
 196                         strerror(-ret));
 197                 return 1;
 198         } else if (ret) {
 199                 fprintf(stderr, "%s is mounted\n", device);
 200                 return 1;
 201         }
 202
 203         root = open_ctree(device, 0, OPEN_CTREE_WRITES);
 204
 205         if (!root) {
 206                 fprintf(stderr, "Open ctree failed\n");
 207                 return 1;
 208         }
 209
 210         if (seeding_flag) {
 211                 if (!seeding_value && !force) {
 212                         fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
 213                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 214                         if (!ret) {
 215                                 fprintf(stderr, "Clear seeding flag canceled\n");
 216                                 return 1;
 217                         }
 218                 }
 219
 220                 ret = update_seeding_flag(root, seeding_value);
 221                 if (!ret)
 222                         success++;
 223                 total++;
 224         }
 225
 226         if (extrefs_flag) {
 227                 enable_extrefs_flag(root);
 228                 success++;
 229                 total++;
 230         }
 231
 232         if (skinny_flag) {
 233                 enable_skinny_metadata(root);
 234                 success++;
 235                 total++;
 236         }
 237
 238         if (success == total) {
 239                 ret = 0;
 240         } else {
 241                 root->fs_info->readonly = 1;
 242                 ret = 1;
 243                 fprintf(stderr, "btrfstune failed\n");
 244         }
 245         close_ctree(root);
 246
 247         return ret;
 248 }