2 * Copyright (C) 2008 Oracle. All rights reserved.
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.
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.
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.
21 #include <sys/types.h>
26 #include <uuid/uuid.h>
29 #include "kerncompat.h"
32 #include "transaction.h"
40 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
42 struct btrfs_trans_handle *trans;
43 struct btrfs_super_block *disk_super;
47 disk_super = root->fs_info->super_copy;
48 super_flags = btrfs_super_flags(disk_super);
50 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
54 warning("seeding flag is already set on %s",
58 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
60 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
61 warning("seeding flag is not set on %s", device);
64 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
65 warning("seeding flag cleared on %s", device);
68 trans = btrfs_start_transaction(root, 1);
69 btrfs_set_super_flags(disk_super, super_flags);
70 ret = btrfs_commit_transaction(trans, root);
75 static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
77 struct btrfs_trans_handle *trans;
78 struct btrfs_super_block *disk_super;
82 disk_super = root->fs_info->super_copy;
83 super_flags = btrfs_super_incompat_flags(disk_super);
85 trans = btrfs_start_transaction(root, 1);
86 btrfs_set_super_incompat_flags(disk_super, super_flags);
87 ret = btrfs_commit_transaction(trans, root);
92 static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
94 struct btrfs_fs_info *fs_info = root->fs_info;
96 int same_chunk_tree_uuid = 1;
99 same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
100 btrfs_header_fsid(), BTRFS_FSID_SIZE);
101 same_chunk_tree_uuid =
102 !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
103 btrfs_header_chunk_tree_uuid(eb),
105 if (same_fsid && same_chunk_tree_uuid)
108 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
110 if (!same_chunk_tree_uuid)
111 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
112 btrfs_header_chunk_tree_uuid(eb),
114 ret = write_tree_block(NULL, root, eb);
119 static int change_extents_uuid(struct btrfs_fs_info *fs_info)
121 struct btrfs_root *root = fs_info->extent_root;
122 struct btrfs_path path;
123 struct btrfs_key key = {0, 0, 0};
126 btrfs_init_path(&path);
128 * Here we don't use transaction as it will takes a lot of reserve
129 * space, and that will make a near-full btrfs unable to change uuid
131 ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
136 struct btrfs_extent_item *ei;
137 struct extent_buffer *eb;
141 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
142 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
143 key.type != BTRFS_METADATA_ITEM_KEY)
145 ei = btrfs_item_ptr(path.nodes[0], path.slots[0],
146 struct btrfs_extent_item);
147 flags = btrfs_extent_flags(path.nodes[0], ei);
148 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
151 bytenr = key.objectid;
152 eb = read_tree_block(root, bytenr, root->nodesize, 0);
154 error("failed to read tree block: %llu", bytenr);
158 ret = change_header_uuid(root, eb);
159 free_extent_buffer(eb);
161 error("failed to change uuid of tree block: %llu",
166 ret = btrfs_next_item(root, &path);
176 btrfs_release_path(&path);
180 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
183 struct btrfs_fs_info *fs_info = root->fs_info;
184 struct btrfs_dev_item *di;
187 di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
188 if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
189 (unsigned long)btrfs_device_fsid(di),
193 write_extent_buffer(eb, fs_info->new_fsid,
194 (unsigned long)btrfs_device_fsid(di),
196 ret = write_tree_block(NULL, root, eb);
201 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
203 struct btrfs_root *root = fs_info->chunk_root;
204 struct btrfs_path path;
205 struct btrfs_key key = {0, 0, 0};
208 btrfs_init_path(&path);
209 /* No transaction again */
210 ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
215 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
216 if (key.type != BTRFS_DEV_ITEM_KEY ||
217 key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
219 ret = change_device_uuid(root, path.nodes[0], path.slots[0]);
223 ret = btrfs_next_item(root, &path);
232 btrfs_release_path(&path);
236 static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
238 struct btrfs_root *tree_root = fs_info->tree_root;
239 u64 flags = btrfs_super_flags(fs_info->super_copy);
242 flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
243 btrfs_set_super_flags(fs_info->super_copy, flags);
245 memcpy(fs_info->super_copy->fsid, fs_info->new_fsid, BTRFS_FSID_SIZE);
246 ret = write_all_supers(tree_root);
250 /* also restore new chunk_tree_id into tree_root for restore */
251 write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
252 btrfs_header_chunk_tree_uuid(tree_root->node),
254 return write_tree_block(NULL, tree_root, tree_root->node);
257 static int change_fsid_done(struct btrfs_fs_info *fs_info)
259 u64 flags = btrfs_super_flags(fs_info->super_copy);
261 flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
262 btrfs_set_super_flags(fs_info->super_copy, flags);
264 return write_all_supers(fs_info->tree_root);
268 * Return 0 for no unfinished fsid change.
269 * Return >0 for unfinished fsid change, and restore unfinished fsid/
270 * chunk_tree_id into fsid_ret/chunk_id_ret.
272 static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
273 uuid_t fsid_ret, uuid_t chunk_id_ret)
275 struct btrfs_root *tree_root = fs_info->tree_root;
276 u64 flags = btrfs_super_flags(fs_info->super_copy);
278 if (flags & BTRFS_SUPER_FLAG_CHANGING_FSID) {
279 memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
280 read_extent_buffer(tree_root->node, chunk_id_ret,
281 btrfs_header_chunk_tree_uuid(tree_root->node),
289 * Change fsid of a given fs.
291 * If new_fsid_str is not given, use a random generated UUID.
292 * Caller should check new_fsid_str is valid
294 static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
299 char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
302 if (check_unfinished_fsid_change(fs_info, new_fsid, new_chunk_id)) {
306 uuid_parse(new_fsid_str, tmp);
307 if (memcmp(tmp, new_fsid, BTRFS_FSID_SIZE)) {
309 "new fsid %s is not the same with unfinished fsid change",
316 uuid_parse(new_fsid_str, new_fsid);
318 uuid_generate(new_fsid);
320 uuid_generate(new_chunk_id);
322 fs_info->new_fsid = new_fsid;
323 fs_info->new_chunk_tree_uuid = new_chunk_id;
325 memcpy(old_fsid, (const char*)fs_info->fsid, BTRFS_UUID_SIZE);
326 uuid_unparse(old_fsid, uuid_buf);
327 printf("Current fsid: %s\n", uuid_buf);
329 uuid_unparse(new_fsid, uuid_buf);
330 printf("New fsid: %s\n", uuid_buf);
331 /* Now we can begin fsid change */
332 printf("Set superblock flag CHANGING_FSID\n");
333 ret = change_fsid_prepare(fs_info);
337 /* Change extents first */
338 printf("Change fsid in extents\n");
339 ret = change_extents_uuid(fs_info);
341 error("failed to change UUID of metadata: %d", ret);
346 printf("Change fsid on devices\n");
347 ret = change_devices_uuid(fs_info);
349 error("failed to change UUID of devices: %d", ret);
353 /* Last, change fsid in super */
354 memcpy(fs_info->fs_devices->fsid, fs_info->new_fsid,
356 memcpy(fs_info->super_copy->fsid, fs_info->new_fsid,
358 ret = write_all_supers(fs_info->tree_root);
362 /* Now fsid change is done */
363 printf("Clear superblock flag CHANGING_FSID\n");
364 ret = change_fsid_done(fs_info);
365 fs_info->new_fsid = NULL;
366 fs_info->new_chunk_tree_uuid = NULL;
367 printf("Fsid change finished\n");
372 static void print_usage(void)
374 printf("usage: btrfstune [options] device\n");
375 printf("\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
376 printf("\t-r \t\tenable extended inode refs\n");
377 printf("\t-x \t\tenable skinny metadata extent refs\n");
378 printf("\t-n \t\tenable no-holes feature (more efficient sparse file representation)\n");
379 printf("\t-f \t\tforce to do dangerous operation, make sure that you are aware of the dangers\n");
380 printf("\t-u \t\tchange fsid, use a random one\n");
381 printf("\t-U UUID\t\tchange fsid to UUID\n");
384 int main(int argc, char *argv[])
386 struct btrfs_root *root;
387 unsigned ctree_flags = OPEN_CTREE_WRITES;
390 int seeding_flag = 0;
391 u64 seeding_value = 0;
393 char *new_fsid_str = NULL;
398 static const struct option long_options[] = {
399 { "help", no_argument, NULL, GETOPT_VAL_HELP},
402 int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL);
409 seeding_value = arg_strtou64(optarg);
412 super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
415 super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
418 super_flags |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
424 ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
425 new_fsid_str = optarg;
428 ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
431 case GETOPT_VAL_HELP:
434 return c != GETOPT_VAL_HELP;
439 device = argv[optind];
440 if (check_argc_exact(argc - optind, 1)) {
445 if (random_fsid && new_fsid_str) {
446 error("random fsid can't be used with specified fsid");
449 if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) {
450 error("at least one option should be specified");
458 ret = uuid_parse(new_fsid_str, tmp);
460 error("could not parse UUID: %s", new_fsid_str);
463 if (!test_uuid_unique(new_fsid_str)) {
464 error("fsid %s is not unique", new_fsid_str);
469 ret = check_mounted(device);
471 error("could not check mount status of %s: %s", device,
475 error("%s is mounted", device);
479 root = open_ctree(device, 0, ctree_flags);
482 error("open ctree failed");
487 if (!seeding_value && !force) {
489 "this is dangerous, clearing the seeding flag may cause the derived device not to be mountable!");
490 ret = ask_user("We are going to clear the seeding flag, are you sure?");
492 fprintf(stderr, "Clear seeding flag canceled\n");
498 ret = update_seeding_flag(root, seeding_value);
505 ret = set_super_incompat_flags(root, super_flags);
511 if (random_fsid || new_fsid_str) {
514 "it's highly recommended to run 'btrfs check' before this operation");
516 "also canceling running UUID change progress may cause corruption");
517 ret = ask_user("We are going to change UUID, are your sure?");
519 fprintf(stderr, "UUID change canceled\n");
524 ret = change_uuid(root->fs_info, new_fsid_str);
530 if (success == total) {
533 root->fs_info->readonly = 1;
535 error("btrfstune failed");
539 btrfs_close_all_devices();