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 int change_extents_uuid(struct btrfs_fs_info *fs_info)
 134 {
 135         struct btrfs_root *root = fs_info->extent_root;
 136         struct btrfs_path *path;
 137         struct btrfs_key key = {0, 0, 0};
 138         int ret = 0;
 139
 140         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 141                 return 0;
 142
 143         path = btrfs_alloc_path();
 144         if (!path)
 145                 return -ENOMEM;
 146
 147         /*
 148          * Here we don't use transaction as it will takes a lot of reserve
 149          * space, and that will make a near-full btrfs unable to change uuid
 150          */
 151         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 152         if (ret < 0)
 153                 goto out;
 154
 155         while (1) {
 156                 struct btrfs_extent_item *ei;
 157                 struct extent_buffer *eb;
 158                 u64 flags;
 159                 u64 bytenr;
 160
 161                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 162                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
 163                     key.type != BTRFS_METADATA_ITEM_KEY)
 164                         goto next;
 165                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
 166                                     struct btrfs_extent_item);
 167                 flags = btrfs_extent_flags(path->nodes[0], ei);
 168                 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
 169                         goto next;
 170
 171                 bytenr = key.objectid;
 172                 eb = read_tree_block(root, bytenr, root->nodesize, 0);
 173                 if (IS_ERR(eb)) {
 174                         fprintf(stderr, "Failed to read tree block: %llu\n",
 175                                 bytenr);
 176                         ret = PTR_ERR(eb);
 177                         goto out;
 178                 }
 179                 ret = change_header_uuid(root, eb);
 180                 free_extent_buffer(eb);
 181                 if (ret < 0) {
 182                         fprintf(stderr, "Failed to change uuid of tree block: %llu\n",
 183                                 bytenr);
 184                         goto out;
 185                 }
 186 next:
 187                 ret = btrfs_next_item(root, path);
 188                 if (ret < 0)
 189                         goto out;
 190                 if (ret > 0) {
 191                         ret = 0;
 192                         goto out;
 193                 }
 194         }
 195
 196 out:
 197         btrfs_free_path(path);
 198         return ret;
 199 }
 200
 201 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
 202                               int slot)
 203 {
 204         struct btrfs_fs_info *fs_info = root->fs_info;
 205         struct btrfs_dev_item *di;
 206         int ret = 0;
 207
 208         di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
 209         if (fs_info->new_fsid) {
 210                 if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
 211                                           (unsigned long)btrfs_device_fsid(di),
 212                                           BTRFS_FSID_SIZE))
 213                         return ret;
 214                 write_extent_buffer(eb, fs_info->new_fsid,
 215                                     (unsigned long)btrfs_device_fsid(di),
 216                                     BTRFS_FSID_SIZE);
 217                 ret = write_tree_block(NULL, root, eb);
 218         }
 219         return ret;
 220 }
 221
 222 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
 223 {
 224         struct btrfs_root *root = fs_info->chunk_root;
 225         struct btrfs_path *path;
 226         struct btrfs_key key = {0, 0, 0};
 227         int ret = 0;
 228
 229         /*
 230          * Unlike change_extents_uuid, we only need to change fsid in dev_item
 231          */
 232         if (!fs_info->new_fsid)
 233                 return 0;
 234
 235         path = btrfs_alloc_path();
 236         if (!path)
 237                 return -ENOMEM;
 238         /* No transaction again */
 239         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 240         if (ret < 0)
 241                 goto out;
 242
 243         while (1) {
 244                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 245                 if (key.type != BTRFS_DEV_ITEM_KEY ||
 246                     key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
 247                         goto next;
 248                 ret = change_device_uuid(root, path->nodes[0], path->slots[0]);
 249                 if (ret < 0)
 250                         goto out;
 251 next:
 252                 ret = btrfs_next_item(root, path);
 253                 if (ret < 0)
 254                         goto out;
 255                 if (ret > 0) {
 256                         ret = 0;
 257                         goto out;
 258                 }
 259         }
 260 out:
 261         btrfs_free_path(path);
 262         return ret;
 263 }
 264
 265 static void print_usage(void)
 266 {
 267         fprintf(stderr, "usage: btrfstune [options] device\n");
 268         fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
 269         fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
 270         fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
 271         fprintf(stderr, "\t-f \t\tforce to set or clear flags, make sure that you are aware of the dangers\n");
 272 }
 273
 274 int main(int argc, char *argv[])
 275 {
 276         struct btrfs_root *root;
 277         int success = 0;
 278         int total = 0;
 279         int extrefs_flag = 0;
 280         int seeding_flag = 0;
 281         u64 seeding_value = 0;
 282         int skinny_flag = 0;
 283         int ret;
 284
 285         optind = 1;
 286         while(1) {
 287                 int c = getopt(argc, argv, "S:rxf");
 288                 if (c < 0)
 289                         break;
 290                 switch(c) {
 291                 case 'S':
 292                         seeding_flag = 1;
 293                         seeding_value = arg_strtou64(optarg);
 294                         break;
 295                 case 'r':
 296                         extrefs_flag = 1;
 297                         break;
 298                 case 'x':
 299                         skinny_flag = 1;
 300                         break;
 301                 case 'f':
 302                         force = 1;
 303                         break;
 304                 default:
 305                         print_usage();
 306                         return 1;
 307                 }
 308         }
 309
 310         set_argv0(argv);
 311         argc = argc - optind;
 312         device = argv[optind];
 313         if (check_argc_exact(argc, 1)) {
 314                 print_usage();
 315                 return 1;
 316         }
 317
 318         if (!(seeding_flag + extrefs_flag + skinny_flag)) {
 319                 fprintf(stderr,
 320                         "ERROR: At least one option should be assigned.\n");
 321                 print_usage();
 322                 return 1;
 323         }
 324
 325         ret = check_mounted(device);
 326         if (ret < 0) {
 327                 fprintf(stderr, "Could not check mount status: %s\n",
 328                         strerror(-ret));
 329                 return 1;
 330         } else if (ret) {
 331                 fprintf(stderr, "%s is mounted\n", device);
 332                 return 1;
 333         }
 334
 335         root = open_ctree(device, 0, OPEN_CTREE_WRITES);
 336
 337         if (!root) {
 338                 fprintf(stderr, "Open ctree failed\n");
 339                 return 1;
 340         }
 341
 342         if (seeding_flag) {
 343                 if (!seeding_value && !force) {
 344                         fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
 345                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 346                         if (!ret) {
 347                                 fprintf(stderr, "Clear seeding flag canceled\n");
 348                                 return 1;
 349                         }
 350                 }
 351
 352                 ret = update_seeding_flag(root, seeding_value);
 353                 if (!ret)
 354                         success++;
 355                 total++;
 356         }
 357
 358         if (extrefs_flag) {
 359                 enable_extrefs_flag(root);
 360                 success++;
 361                 total++;
 362         }
 363
 364         if (skinny_flag) {
 365                 enable_skinny_metadata(root);
 366                 success++;
 367                 total++;
 368         }
 369
 370         if (success == total) {
 371                 ret = 0;
 372         } else {
 373                 root->fs_info->readonly = 1;
 374                 ret = 1;
 375                 fprintf(stderr, "btrfstune failed\n");
 376         }
 377         close_ctree(root);
 378
 379         return ret;
 380 }