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"
39 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
41 struct btrfs_trans_handle *trans;
42 struct btrfs_super_block *disk_super;
46 disk_super = root->fs_info->super_copy;
47 super_flags = btrfs_super_flags(disk_super);
49 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
53 warning("seeding flag is already set on %s",
57 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
59 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
60 warning("seeding flag is not set on %s", device);
63 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
64 warning("seeding flag cleared on %s", device);
67 trans = btrfs_start_transaction(root, 1);
68 btrfs_set_super_flags(disk_super, super_flags);
69 ret = btrfs_commit_transaction(trans, root);
74 static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
76 struct btrfs_trans_handle *trans;
77 struct btrfs_super_block *disk_super;
81 disk_super = root->fs_info->super_copy;
82 super_flags = btrfs_super_incompat_flags(disk_super);
84 trans = btrfs_start_transaction(root, 1);
85 btrfs_set_super_incompat_flags(disk_super, super_flags);
86 ret = btrfs_commit_transaction(trans, root);
91 static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
93 struct btrfs_fs_info *fs_info = root->fs_info;
95 int same_chunk_tree_uuid = 1;
98 same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
99 btrfs_header_fsid(), BTRFS_FSID_SIZE);
100 same_chunk_tree_uuid =
101 !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
102 btrfs_header_chunk_tree_uuid(eb),
104 if (same_fsid && same_chunk_tree_uuid)
107 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
109 if (!same_chunk_tree_uuid)
110 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
111 btrfs_header_chunk_tree_uuid(eb),
113 ret = write_tree_block(NULL, root, eb);
118 static int change_extents_uuid(struct btrfs_fs_info *fs_info)
120 struct btrfs_root *root = fs_info->extent_root;
121 struct btrfs_path path;
122 struct btrfs_key key = {0, 0, 0};
125 btrfs_init_path(&path);
127 * Here we don't use transaction as it will takes a lot of reserve
128 * space, and that will make a near-full btrfs unable to change uuid
130 ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
135 struct btrfs_extent_item *ei;
136 struct extent_buffer *eb;
140 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
141 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
142 key.type != BTRFS_METADATA_ITEM_KEY)
144 ei = btrfs_item_ptr(path.nodes[0], path.slots[0],
145 struct btrfs_extent_item);
146 flags = btrfs_extent_flags(path.nodes[0], ei);
147 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
150 bytenr = key.objectid;
151 eb = read_tree_block(root, bytenr, root->nodesize, 0);
153 error("failed to read tree block: %llu", bytenr);
157 ret = change_header_uuid(root, eb);
158 free_extent_buffer(eb);
160 error("failed to change uuid of tree block: %llu",
165 ret = btrfs_next_item(root, &path);
175 btrfs_release_path(&path);
179 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
182 struct btrfs_fs_info *fs_info = root->fs_info;
183 struct btrfs_dev_item *di;
186 di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
187 if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
188 (unsigned long)btrfs_device_fsid(di),
192 write_extent_buffer(eb, fs_info->new_fsid,
193 (unsigned long)btrfs_device_fsid(di),
195 ret = write_tree_block(NULL, root, eb);
200 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
202 struct btrfs_root *root = fs_info->chunk_root;
203 struct btrfs_path *path;
204 struct btrfs_key key = {0, 0, 0};
207 path = btrfs_alloc_path();
210 /* No transaction again */
211 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
216 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
217 if (key.type != BTRFS_DEV_ITEM_KEY ||
218 key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
220 ret = change_device_uuid(root, path->nodes[0], path->slots[0]);
224 ret = btrfs_next_item(root, path);
233 btrfs_free_path(path);
237 static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
239 struct btrfs_root *tree_root = fs_info->tree_root;
240 u64 flags = btrfs_super_flags(fs_info->super_copy);
243 flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
244 btrfs_set_super_flags(fs_info->super_copy, flags);
246 memcpy(fs_info->super_copy->fsid, fs_info->new_fsid, BTRFS_FSID_SIZE);
247 ret = write_all_supers(tree_root);
251 /* also restore new chunk_tree_id into tree_root for restore */
252 write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
253 btrfs_header_chunk_tree_uuid(tree_root->node),
255 return write_tree_block(NULL, tree_root, tree_root->node);
258 static int change_fsid_done(struct btrfs_fs_info *fs_info)
260 u64 flags = btrfs_super_flags(fs_info->super_copy);
262 flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
263 btrfs_set_super_flags(fs_info->super_copy, flags);
265 return write_all_supers(fs_info->tree_root);
269 * Return 0 for no unfinished fsid change.
270 * Return >0 for unfinished fsid change, and restore unfinished fsid/
271 * chunk_tree_id into fsid_ret/chunk_id_ret.
273 static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
274 uuid_t fsid_ret, uuid_t chunk_id_ret)
276 struct btrfs_root *tree_root = fs_info->tree_root;
277 u64 flags = btrfs_super_flags(fs_info->super_copy);
279 if (flags & BTRFS_SUPER_FLAG_CHANGING_FSID) {
280 memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
281 read_extent_buffer(tree_root->node, chunk_id_ret,
282 btrfs_header_chunk_tree_uuid(tree_root->node),
290 * Change fsid of a given fs.
292 * If new_fsid_str is not given, use a random generated UUID.
293 * Caller should check new_fsid_str is valid
295 static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
300 char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
303 if (check_unfinished_fsid_change(fs_info, new_fsid, new_chunk_id)) {
307 uuid_parse(new_fsid_str, tmp);
308 if (memcmp(tmp, new_fsid, BTRFS_FSID_SIZE)) {
310 "new fsid %s is not the same with unfinished fsid change",
317 uuid_parse(new_fsid_str, new_fsid);
319 uuid_generate(new_fsid);
321 uuid_generate(new_chunk_id);
323 fs_info->new_fsid = new_fsid;
324 fs_info->new_chunk_tree_uuid = new_chunk_id;
326 memcpy(old_fsid, (const char*)fs_info->fsid, BTRFS_UUID_SIZE);
327 uuid_unparse(old_fsid, uuid_buf);
328 printf("Current fsid: %s\n", uuid_buf);
330 uuid_unparse(new_fsid, uuid_buf);
331 printf("New fsid: %s\n", uuid_buf);
332 /* Now we can begin fsid change */
333 printf("Set superblock flag CHANGING_FSID\n");
334 ret = change_fsid_prepare(fs_info);
338 /* Change extents first */
339 printf("Change fsid in extents\n");
340 ret = change_extents_uuid(fs_info);
342 error("failed to change UUID of metadata: %d", ret);
347 printf("Change fsid on devices\n");
348 ret = change_devices_uuid(fs_info);
350 error("failed to change UUID of devices: %d", ret);
354 /* Last, change fsid in super */
355 memcpy(fs_info->fs_devices->fsid, fs_info->new_fsid,
357 memcpy(fs_info->super_copy->fsid, fs_info->new_fsid,
359 ret = write_all_supers(fs_info->tree_root);
363 /* Now fsid change is done */
364 printf("Clear superblock flag CHANGING_FSID\n");
365 ret = change_fsid_done(fs_info);
366 fs_info->new_fsid = NULL;
367 fs_info->new_chunk_tree_uuid = NULL;
368 printf("Fsid change finished\n");
373 static void print_usage(void)
375 printf("usage: btrfstune [options] device\n");
376 printf("\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
377 printf("\t-r \t\tenable extended inode refs\n");
378 printf("\t-x \t\tenable skinny metadata extent refs\n");
379 printf("\t-n \t\tenable no-holes feature (more efficient sparse file representation)\n");
380 printf("\t-f \t\tforce to do dangerous operation, make sure that you are aware of the dangers\n");
381 printf("\t-u \t\tchange fsid, use a random one\n");
382 printf("\t-U UUID\t\tchange fsid to UUID\n");
385 int main(int argc, char *argv[])
387 struct btrfs_root *root;
388 unsigned ctree_flags = OPEN_CTREE_WRITES;
391 int seeding_flag = 0;
392 u64 seeding_value = 0;
394 char *new_fsid_str = NULL;
399 static const struct option long_options[] = {
400 { "help", no_argument, NULL, GETOPT_VAL_HELP},
403 int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL);
410 seeding_value = arg_strtou64(optarg);
413 super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
416 super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
419 super_flags |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
425 ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
426 new_fsid_str = optarg;
429 ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
432 case GETOPT_VAL_HELP:
435 return c != GETOPT_VAL_HELP;
440 device = argv[optind];
441 if (check_argc_exact(argc - optind, 1)) {
446 if (random_fsid && new_fsid_str) {
447 error("random fsid can't be used with specified fsid");
450 if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) {
451 error("at least one option should be specified");
459 ret = uuid_parse(new_fsid_str, tmp);
461 error("could not parse UUID: %s", new_fsid_str);
464 if (!test_uuid_unique(new_fsid_str)) {
465 error("fsid %s is not unique", new_fsid_str);
470 ret = check_mounted(device);
472 error("could not check mount status of %s: %s", device,
476 error("%s is mounted", device);
480 root = open_ctree(device, 0, ctree_flags);
483 error("open ctree failed");
488 if (!seeding_value && !force) {
490 "this is dangerous, clearing the seeding flag may cause the derived device not to be mountable!");
491 ret = ask_user("We are going to clear the seeding flag, are you sure?");
493 fprintf(stderr, "Clear seeding flag canceled\n");
499 ret = update_seeding_flag(root, seeding_value);
506 ret = set_super_incompat_flags(root, super_flags);
512 if (random_fsid || new_fsid_str) {
515 "it's highly recommended to run 'btrfs check' before this operation");
517 "also canceling running UUID change progress may cause corruption");
518 ret = ask_user("We are going to change UUID, are your sure?");
520 fprintf(stderr, "UUID change canceled\n");
525 ret = change_uuid(root->fs_info, new_fsid_str);
531 if (success == total) {
534 root->fs_info->readonly = 1;
536 error("btrfstune failed");
540 btrfs_close_all_devices();