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btrfs-progs: docs: update check options
[btrfs-progs-unstable/devel.git] / disk-io.c
blob88015b72cd337af222d88b9b64be5f6edfe91229
1 /*
2 * Copyright (C) 2007 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 <uuid/uuid.h>
26 #include "kerncompat.h"
27 #include "radix-tree.h"
28 #include "ctree.h"
29 #include "disk-io.h"
30 #include "volumes.h"
31 #include "transaction.h"
32 #include "crc32c.h"
33 #include "utils.h"
34 #include "print-tree.h"
35 #include "rbtree-utils.h"
36
37 /* specified errno for check_tree_block */
38 #define BTRFS_BAD_BYTENR (-1)
39 #define BTRFS_BAD_FSID (-2)
40 #define BTRFS_BAD_LEVEL (-3)
41 #define BTRFS_BAD_NRITEMS (-4)
42
43 /* Calculate max possible nritems for a leaf/node */
44 static u32 max_nritems(u8 level, u32 nodesize)
45 {
46
47 if (level == 0)
48 return ((nodesize - sizeof(struct btrfs_header)) /
49 sizeof(struct btrfs_item));
50 return ((nodesize - sizeof(struct btrfs_header)) /
51 sizeof(struct btrfs_key_ptr));
52 }
53
54 static int check_tree_block(struct btrfs_fs_info *fs_info,
55 struct extent_buffer *buf)
56 {
57
58 struct btrfs_fs_devices *fs_devices;
59 u32 leafsize = btrfs_super_leafsize(fs_info->super_copy);
60 int ret = BTRFS_BAD_FSID;
61
62 if (buf->start != btrfs_header_bytenr(buf))
63 return BTRFS_BAD_BYTENR;
64 if (btrfs_header_level(buf) >= BTRFS_MAX_LEVEL)
65 return BTRFS_BAD_LEVEL;
66 if (btrfs_header_nritems(buf) > max_nritems(btrfs_header_level(buf),
67 leafsize))
68 return BTRFS_BAD_NRITEMS;
69
70 fs_devices = fs_info->fs_devices;
71 while (fs_devices) {
72 if (fs_info->ignore_fsid_mismatch ||
73 !memcmp_extent_buffer(buf, fs_devices->fsid,
74 btrfs_header_fsid(),
75 BTRFS_FSID_SIZE)) {
76 ret = 0;
77 break;
78 }
79 fs_devices = fs_devices->seed;
80 }
81 return ret;
82 }
83
84 static void print_tree_block_error(struct btrfs_fs_info *fs_info,
85 struct extent_buffer *eb,
86 int err)
87 {
88 char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
89 char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
90 u8 buf[BTRFS_UUID_SIZE];
91
92 switch (err) {
93 case BTRFS_BAD_FSID:
94 read_extent_buffer(eb, buf, btrfs_header_fsid(),
95 BTRFS_UUID_SIZE);
96 uuid_unparse(buf, found_uuid);
97 uuid_unparse(fs_info->fsid, fs_uuid);
98 fprintf(stderr, "fsid mismatch, want=%s, have=%s\n",
99 fs_uuid, found_uuid);
100 break;
101 case BTRFS_BAD_BYTENR:
102 fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n",
103 eb->start, btrfs_header_bytenr(eb));
104 break;
105 case BTRFS_BAD_LEVEL:
106 fprintf(stderr, "bad level, %u > %u\n",
107 btrfs_header_level(eb), BTRFS_MAX_LEVEL);
108 break;
109 case BTRFS_BAD_NRITEMS:
110 fprintf(stderr, "invalid nr_items: %u\n",
111 btrfs_header_nritems(eb));
112 break;
113 }
114 }
115
116 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
117 {
118 return crc32c(seed, data, len);
119 }
120
121 void btrfs_csum_final(u32 crc, char *result)
122 {
123 *(__le32 *)result = ~cpu_to_le32(crc);
124 }
125
126 static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
127 int verify, int silent)
128 {
129 char result[BTRFS_CSUM_SIZE];
130 u32 len;
131 u32 crc = ~(u32)0;
132
133 len = buf->len - BTRFS_CSUM_SIZE;
134 crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
135 btrfs_csum_final(crc, result);
136
137 if (verify) {
138 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
139 if (!silent)
140 printk("checksum verify failed on %llu found %08X wanted %08X\n",
141 (unsigned long long)buf->start,
142 *((u32 *)result),
143 *((u32*)(char *)buf->data));
144 return 1;
145 }
146 } else {
147 write_extent_buffer(buf, result, 0, csum_size);
148 }
149 return 0;
150 }
151
152 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
153 {
154 return __csum_tree_block_size(buf, csum_size, verify, 0);
155 }
156
157 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
158 {
159 return __csum_tree_block_size(buf, csum_size, 1, 1);
160 }
161
162 static int csum_tree_block_fs_info(struct btrfs_fs_info *fs_info,
163 struct extent_buffer *buf, int verify)
164 {
165 u16 csum_size =
166 btrfs_super_csum_size(fs_info->super_copy);
167 if (verify && fs_info->suppress_check_block_errors)
168 return verify_tree_block_csum_silent(buf, csum_size);
169 return csum_tree_block_size(buf, csum_size, verify);
170 }
171
172 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
173 int verify)
174 {
175 return csum_tree_block_fs_info(root->fs_info, buf, verify);
176 }
177
178 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
179 u64 bytenr, u32 blocksize)
180 {
181 return find_extent_buffer(&root->fs_info->extent_cache,
182 bytenr, blocksize);
183 }
184
185 struct extent_buffer* btrfs_find_create_tree_block(
186 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize)
187 {
188 return alloc_extent_buffer(&fs_info->extent_cache, bytenr, blocksize);
189 }
190
191 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
192 u64 parent_transid)
193 {
194 struct extent_buffer *eb;
195 u64 length;
196 struct btrfs_multi_bio *multi = NULL;
197 struct btrfs_device *device;
198
199 eb = btrfs_find_tree_block(root, bytenr, blocksize);
200 if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
201 !btrfs_map_block(&root->fs_info->mapping_tree, READ,
202 bytenr, &length, &multi, 0, NULL)) {
203 device = multi->stripes[0].dev;
204 device->total_ios++;
205 blocksize = min(blocksize, (u32)(64 * 1024));
206 readahead(device->fd, multi->stripes[0].physical, blocksize);
207 }
208
209 free_extent_buffer(eb);
210 kfree(multi);
211 }
212
213 static int verify_parent_transid(struct extent_io_tree *io_tree,
214 struct extent_buffer *eb, u64 parent_transid,
215 int ignore)
216 {
217 int ret;
218
219 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
220 return 0;
221
222 if (extent_buffer_uptodate(eb) &&
223 btrfs_header_generation(eb) == parent_transid) {
224 ret = 0;
225 goto out;
226 }
227 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
228 (unsigned long long)eb->start,
229 (unsigned long long)parent_transid,
230 (unsigned long long)btrfs_header_generation(eb));
231 if (ignore) {
232 eb->flags |= EXTENT_BAD_TRANSID;
233 printk("Ignoring transid failure\n");
234 return 0;
235 }
236
237 ret = 1;
238 out:
239 clear_extent_buffer_uptodate(io_tree, eb);
240 return ret;
241
242 }
243
244
245 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
246 {
247 unsigned long offset = 0;
248 struct btrfs_multi_bio *multi = NULL;
249 struct btrfs_device *device;
250 int ret = 0;
251 u64 read_len;
252 unsigned long bytes_left = eb->len;
253
254 while (bytes_left) {
255 read_len = bytes_left;
256 device = NULL;
257
258 if (!info->on_restoring &&
259 eb->start != BTRFS_SUPER_INFO_OFFSET) {
260 ret = btrfs_map_block(&info->mapping_tree, READ,
261 eb->start + offset, &read_len, &multi,
262 mirror, NULL);
263 if (ret) {
264 printk("Couldn't map the block %Lu\n", eb->start + offset);
265 kfree(multi);
266 return -EIO;
267 }
268 device = multi->stripes[0].dev;
269
270 if (device->fd <= 0) {
271 kfree(multi);
272 return -EIO;
273 }
274
275 eb->fd = device->fd;
276 device->total_ios++;
277 eb->dev_bytenr = multi->stripes[0].physical;
278 kfree(multi);
279 multi = NULL;
280 } else {
281 /* special case for restore metadump */
282 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
283 if (device->devid == 1)
284 break;
285 }
286
287 eb->fd = device->fd;
288 eb->dev_bytenr = eb->start;
289 device->total_ios++;
290 }
291
292 if (read_len > bytes_left)
293 read_len = bytes_left;
294
295 ret = read_extent_from_disk(eb, offset, read_len);
296 if (ret)
297 return -EIO;
298 offset += read_len;
299 bytes_left -= read_len;
300 }
301 return 0;
302 }
303
304 struct extent_buffer* read_tree_block_fs_info(
305 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
306 u64 parent_transid)
307 {
308 int ret;
309 struct extent_buffer *eb;
310 u64 best_transid = 0;
311 int mirror_num = 0;
312 int good_mirror = 0;
313 int num_copies;
314 int ignore = 0;
315
316 eb = btrfs_find_create_tree_block(fs_info, bytenr, blocksize);
317 if (!eb)
318 return ERR_PTR(-ENOMEM);
319
320 if (btrfs_buffer_uptodate(eb, parent_transid))
321 return eb;
322
323 while (1) {
324 ret = read_whole_eb(fs_info, eb, mirror_num);
325 if (ret == 0 && csum_tree_block_fs_info(fs_info, eb, 1) == 0 &&
326 check_tree_block(fs_info, eb) == 0 &&
327 verify_parent_transid(eb->tree, eb, parent_transid, ignore)
328 == 0) {
329 if (eb->flags & EXTENT_BAD_TRANSID &&
330 list_empty(&eb->recow)) {
331 list_add_tail(&eb->recow,
332 &fs_info->recow_ebs);
333 eb->refs++;
334 }
335 btrfs_set_buffer_uptodate(eb);
336 return eb;
337 }
338 if (ignore) {
339 if (check_tree_block(fs_info, eb)) {
340 if (!fs_info->suppress_check_block_errors)
341 print_tree_block_error(fs_info, eb,
342 check_tree_block(fs_info, eb));
343 } else {
344 if (!fs_info->suppress_check_block_errors)
345 fprintf(stderr, "Csum didn't match\n");
346 }
347 ret = -EIO;
348 break;
349 }
350 num_copies = btrfs_num_copies(&fs_info->mapping_tree,
351 eb->start, eb->len);
352 if (num_copies == 1) {
353 ignore = 1;
354 continue;
355 }
356 if (btrfs_header_generation(eb) > best_transid && mirror_num) {
357 best_transid = btrfs_header_generation(eb);
358 good_mirror = mirror_num;
359 }
360 mirror_num++;
361 if (mirror_num > num_copies) {
362 mirror_num = good_mirror;
363 ignore = 1;
364 continue;
365 }
366 }
367 free_extent_buffer(eb);
368 return ERR_PTR(ret);
369 }
370
371 int read_extent_data(struct btrfs_root *root, char *data,
372 u64 logical, u64 *len, int mirror)
373 {
374 u64 offset = 0;
375 struct btrfs_multi_bio *multi = NULL;
376 struct btrfs_fs_info *info = root->fs_info;
377 struct btrfs_device *device;
378 int ret = 0;
379 u64 max_len = *len;
380
381 ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
382 &multi, mirror, NULL);
383 if (ret) {
384 fprintf(stderr, "Couldn't map the block %llu\n",
385 logical + offset);
386 goto err;
387 }
388 device = multi->stripes[0].dev;
389
390 if (device->fd <= 0)
391 goto err;
392 if (*len > max_len)
393 *len = max_len;
394
395 ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
396 if (ret != *len)
397 ret = -EIO;
398 else
399 ret = 0;
400 err:
401 kfree(multi);
402 return ret;
403 }
404
405 int write_and_map_eb(struct btrfs_trans_handle *trans,
406 struct btrfs_root *root,
407 struct extent_buffer *eb)
408 {
409 int ret;
410 int dev_nr;
411 u64 length;
412 u64 *raid_map = NULL;
413 struct btrfs_multi_bio *multi = NULL;
414
415 dev_nr = 0;
416 length = eb->len;
417 ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
418 eb->start, &length, &multi, 0, &raid_map);
419
420 if (raid_map) {
421 ret = write_raid56_with_parity(root->fs_info, eb, multi,
422 length, raid_map);
423 BUG_ON(ret);
424 } else while (dev_nr < multi->num_stripes) {
425 BUG_ON(ret);
426 eb->fd = multi->stripes[dev_nr].dev->fd;
427 eb->dev_bytenr = multi->stripes[dev_nr].physical;
428 multi->stripes[dev_nr].dev->total_ios++;
429 dev_nr++;
430 ret = write_extent_to_disk(eb);
431 BUG_ON(ret);
432 }
433 kfree(raid_map);
434 kfree(multi);
435 return 0;
436 }
437
438 int write_tree_block(struct btrfs_trans_handle *trans,
439 struct btrfs_root *root,
440 struct extent_buffer *eb)
441 {
442 if (check_tree_block(root->fs_info, eb)) {
443 print_tree_block_error(root->fs_info, eb,
444 check_tree_block(root->fs_info, eb));
445 BUG();
446 }
447
448 if (trans && !btrfs_buffer_uptodate(eb, trans->transid))
449 BUG();
450
451 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
452 csum_tree_block(root, eb, 0);
453
454 return write_and_map_eb(trans, root, eb);
455 }
456
457 int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
458 u32 stripesize, struct btrfs_root *root,
459 struct btrfs_fs_info *fs_info, u64 objectid)
460 {
461 root->node = NULL;
462 root->commit_root = NULL;
463 root->sectorsize = sectorsize;
464 root->nodesize = nodesize;
465 root->leafsize = leafsize;
466 root->stripesize = stripesize;
467 root->ref_cows = 0;
468 root->track_dirty = 0;
469
470 root->fs_info = fs_info;
471 root->objectid = objectid;
472 root->last_trans = 0;
473 root->highest_inode = 0;
474 root->last_inode_alloc = 0;
475
476 INIT_LIST_HEAD(&root->dirty_list);
477 INIT_LIST_HEAD(&root->orphan_data_extents);
478 memset(&root->root_key, 0, sizeof(root->root_key));
479 memset(&root->root_item, 0, sizeof(root->root_item));
480 root->root_key.objectid = objectid;
481 return 0;
482 }
483
484 static int update_cowonly_root(struct btrfs_trans_handle *trans,
485 struct btrfs_root *root)
486 {
487 int ret;
488 u64 old_root_bytenr;
489 struct btrfs_root *tree_root = root->fs_info->tree_root;
490
491 btrfs_write_dirty_block_groups(trans, root);
492 while(1) {
493 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
494 if (old_root_bytenr == root->node->start)
495 break;
496 btrfs_set_root_bytenr(&root->root_item,
497 root->node->start);
498 btrfs_set_root_generation(&root->root_item,
499 trans->transid);
500 root->root_item.level = btrfs_header_level(root->node);
501 ret = btrfs_update_root(trans, tree_root,
502 &root->root_key,
503 &root->root_item);
504 BUG_ON(ret);
505 btrfs_write_dirty_block_groups(trans, root);
506 }
507 return 0;
508 }
509
510 static int commit_tree_roots(struct btrfs_trans_handle *trans,
511 struct btrfs_fs_info *fs_info)
512 {
513 struct btrfs_root *root;
514 struct list_head *next;
515 struct extent_buffer *eb;
516 int ret;
517
518 if (fs_info->readonly)
519 return 0;
520
521 eb = fs_info->tree_root->node;
522 extent_buffer_get(eb);
523 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
524 free_extent_buffer(eb);
525 if (ret)
526 return ret;
527
528 while(!list_empty(&fs_info->dirty_cowonly_roots)) {
529 next = fs_info->dirty_cowonly_roots.next;
530 list_del_init(next);
531 root = list_entry(next, struct btrfs_root, dirty_list);
532 update_cowonly_root(trans, root);
533 free_extent_buffer(root->commit_root);
534 root->commit_root = NULL;
535 }
536
537 return 0;
538 }
539
540 static int __commit_transaction(struct btrfs_trans_handle *trans,
541 struct btrfs_root *root)
542 {
543 u64 start;
544 u64 end;
545 struct extent_buffer *eb;
546 struct extent_io_tree *tree = &root->fs_info->extent_cache;
547 int ret;
548
549 while(1) {
550 ret = find_first_extent_bit(tree, 0, &start, &end,
551 EXTENT_DIRTY);
552 if (ret)
553 break;
554 while(start <= end) {
555 eb = find_first_extent_buffer(tree, start);
556 BUG_ON(!eb || eb->start != start);
557 ret = write_tree_block(trans, root, eb);
558 BUG_ON(ret);
559 start += eb->len;
560 clear_extent_buffer_dirty(eb);
561 free_extent_buffer(eb);
562 }
563 }
564 return 0;
565 }
566
567 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
568 struct btrfs_root *root)
569 {
570 u64 transid = trans->transid;
571 int ret = 0;
572 struct btrfs_fs_info *fs_info = root->fs_info;
573
574 if (root->commit_root == root->node)
575 goto commit_tree;
576 if (root == root->fs_info->tree_root)
577 goto commit_tree;
578 if (root == root->fs_info->chunk_root)
579 goto commit_tree;
580
581 free_extent_buffer(root->commit_root);
582 root->commit_root = NULL;
583
584 btrfs_set_root_bytenr(&root->root_item, root->node->start);
585 btrfs_set_root_generation(&root->root_item, trans->transid);
586 root->root_item.level = btrfs_header_level(root->node);
587 ret = btrfs_update_root(trans, root->fs_info->tree_root,
588 &root->root_key, &root->root_item);
589 BUG_ON(ret);
590 commit_tree:
591 ret = commit_tree_roots(trans, fs_info);
592 BUG_ON(ret);
593 ret = __commit_transaction(trans, root);
594 BUG_ON(ret);
595 write_ctree_super(trans, root);
596 btrfs_finish_extent_commit(trans, fs_info->extent_root,
597 &fs_info->pinned_extents);
598 btrfs_free_transaction(root, trans);
599 free_extent_buffer(root->commit_root);
600 root->commit_root = NULL;
601 fs_info->running_transaction = NULL;
602 fs_info->last_trans_committed = transid;
603 return 0;
604 }
605
606 static int find_and_setup_root(struct btrfs_root *tree_root,
607 struct btrfs_fs_info *fs_info,
608 u64 objectid, struct btrfs_root *root)
609 {
610 int ret;
611 u32 blocksize;
612 u64 generation;
613
614 __setup_root(tree_root->nodesize, tree_root->leafsize,
615 tree_root->sectorsize, tree_root->stripesize,
616 root, fs_info, objectid);
617 ret = btrfs_find_last_root(tree_root, objectid,
618 &root->root_item, &root->root_key);
619 if (ret)
620 return ret;
621
622 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
623 generation = btrfs_root_generation(&root->root_item);
624 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
625 blocksize, generation);
626 if (!extent_buffer_uptodate(root->node))
627 return -EIO;
628
629 return 0;
630 }
631
632 static int find_and_setup_log_root(struct btrfs_root *tree_root,
633 struct btrfs_fs_info *fs_info,
634 struct btrfs_super_block *disk_super)
635 {
636 u32 blocksize;
637 u64 blocknr = btrfs_super_log_root(disk_super);
638 struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
639
640 if (!log_root)
641 return -ENOMEM;
642
643 if (blocknr == 0) {
644 free(log_root);
645 return 0;
646 }
647
648 blocksize = btrfs_level_size(tree_root,
649 btrfs_super_log_root_level(disk_super));
650
651 __setup_root(tree_root->nodesize, tree_root->leafsize,
652 tree_root->sectorsize, tree_root->stripesize,
653 log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
654
655 log_root->node = read_tree_block(tree_root, blocknr,
656 blocksize,
657 btrfs_super_generation(disk_super) + 1);
658
659 fs_info->log_root_tree = log_root;
660
661 if (!extent_buffer_uptodate(log_root->node)) {
662 free_extent_buffer(log_root->node);
663 free(log_root);
664 fs_info->log_root_tree = NULL;
665 return -EIO;
666 }
667
668 return 0;
669 }
670
671 int btrfs_free_fs_root(struct btrfs_root *root)
672 {
673 if (root->node)
674 free_extent_buffer(root->node);
675 if (root->commit_root)
676 free_extent_buffer(root->commit_root);
677 kfree(root);
678 return 0;
679 }
680
681 static void __free_fs_root(struct rb_node *node)
682 {
683 struct btrfs_root *root;
684
685 root = container_of(node, struct btrfs_root, rb_node);
686 btrfs_free_fs_root(root);
687 }
688
689 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
690
691 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
692 struct btrfs_key *location)
693 {
694 struct btrfs_root *root;
695 struct btrfs_root *tree_root = fs_info->tree_root;
696 struct btrfs_path *path;
697 struct extent_buffer *l;
698 u64 generation;
699 u32 blocksize;
700 int ret = 0;
701
702 root = calloc(1, sizeof(*root));
703 if (!root)
704 return ERR_PTR(-ENOMEM);
705 if (location->offset == (u64)-1) {
706 ret = find_and_setup_root(tree_root, fs_info,
707 location->objectid, root);
708 if (ret) {
709 free(root);
710 return ERR_PTR(ret);
711 }
712 goto insert;
713 }
714
715 __setup_root(tree_root->nodesize, tree_root->leafsize,
716 tree_root->sectorsize, tree_root->stripesize,
717 root, fs_info, location->objectid);
718
719 path = btrfs_alloc_path();
720 BUG_ON(!path);
721 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
722 if (ret != 0) {
723 if (ret > 0)
724 ret = -ENOENT;
725 goto out;
726 }
727 l = path->nodes[0];
728 read_extent_buffer(l, &root->root_item,
729 btrfs_item_ptr_offset(l, path->slots[0]),
730 sizeof(root->root_item));
731 memcpy(&root->root_key, location, sizeof(*location));
732 ret = 0;
733 out:
734 btrfs_free_path(path);
735 if (ret) {
736 free(root);
737 return ERR_PTR(ret);
738 }
739 generation = btrfs_root_generation(&root->root_item);
740 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
741 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
742 blocksize, generation);
743 if (!extent_buffer_uptodate(root->node)) {
744 free(root);
745 return ERR_PTR(-EIO);
746 }
747 insert:
748 root->ref_cows = 1;
749 return root;
750 }
751
752 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
753 void *data)
754 {
755 u64 objectid = *((u64 *)data);
756 struct btrfs_root *root;
757
758 root = rb_entry(node, struct btrfs_root, rb_node);
759 if (objectid > root->objectid)
760 return 1;
761 else if (objectid < root->objectid)
762 return -1;
763 else
764 return 0;
765 }
766
767 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
768 struct rb_node *node2)
769 {
770 struct btrfs_root *root;
771
772 root = rb_entry(node2, struct btrfs_root, rb_node);
773 return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
774 }
775
776 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
777 struct btrfs_key *location)
778 {
779 struct btrfs_root *root;
780 struct rb_node *node;
781 int ret;
782 u64 objectid = location->objectid;
783
784 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
785 return fs_info->tree_root;
786 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
787 return fs_info->extent_root;
788 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
789 return fs_info->chunk_root;
790 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
791 return fs_info->dev_root;
792 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
793 return fs_info->csum_root;
794 if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
795 return fs_info->quota_root;
796
797 BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
798 location->offset != (u64)-1);
799
800 node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
801 btrfs_fs_roots_compare_objectids, NULL);
802 if (node)
803 return container_of(node, struct btrfs_root, rb_node);
804
805 root = btrfs_read_fs_root_no_cache(fs_info, location);
806 if (IS_ERR(root))
807 return root;
808
809 ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
810 btrfs_fs_roots_compare_roots);
811 BUG_ON(ret);
812 return root;
813 }
814
815 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
816 {
817 free(fs_info->tree_root);
818 free(fs_info->extent_root);
819 free(fs_info->chunk_root);
820 free(fs_info->dev_root);
821 free(fs_info->csum_root);
822 free(fs_info->quota_root);
823 free(fs_info->free_space_root);
824 free(fs_info->super_copy);
825 free(fs_info->log_root_tree);
826 free(fs_info);
827 }
828
829 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
830 {
831 struct btrfs_fs_info *fs_info;
832
833 fs_info = calloc(1, sizeof(struct btrfs_fs_info));
834 if (!fs_info)
835 return NULL;
836
837 fs_info->tree_root = calloc(1, sizeof(struct btrfs_root));
838 fs_info->extent_root = calloc(1, sizeof(struct btrfs_root));
839 fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root));
840 fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
841 fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
842 fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
843 fs_info->free_space_root = calloc(1, sizeof(struct btrfs_root));
844 fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
845
846 if (!fs_info->tree_root || !fs_info->extent_root ||
847 !fs_info->chunk_root || !fs_info->dev_root ||
848 !fs_info->csum_root || !fs_info->quota_root ||
849 !fs_info->free_space_root || !fs_info->super_copy)
850 goto free_all;
851
852 extent_io_tree_init(&fs_info->extent_cache);
853 extent_io_tree_init(&fs_info->free_space_cache);
854 extent_io_tree_init(&fs_info->block_group_cache);
855 extent_io_tree_init(&fs_info->pinned_extents);
856 extent_io_tree_init(&fs_info->pending_del);
857 extent_io_tree_init(&fs_info->extent_ins);
858 fs_info->excluded_extents = NULL;
859
860 fs_info->fs_root_tree = RB_ROOT;
861 cache_tree_init(&fs_info->mapping_tree.cache_tree);
862
863 mutex_init(&fs_info->fs_mutex);
864 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
865 INIT_LIST_HEAD(&fs_info->space_info);
866 INIT_LIST_HEAD(&fs_info->recow_ebs);
867
868 if (!writable)
869 fs_info->readonly = 1;
870
871 fs_info->super_bytenr = sb_bytenr;
872 fs_info->data_alloc_profile = (u64)-1;
873 fs_info->metadata_alloc_profile = (u64)-1;
874 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
875 return fs_info;
876 free_all:
877 btrfs_free_fs_info(fs_info);
878 return NULL;
879 }
880
881 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
882 {
883 u64 features;
884
885 features = btrfs_super_incompat_flags(sb) &
886 ~BTRFS_FEATURE_INCOMPAT_SUPP;
887 if (features) {
888 printk("couldn't open because of unsupported "
889 "option features (%Lx).\n",
890 (unsigned long long)features);
891 return -ENOTSUP;
892 }
893
894 features = btrfs_super_incompat_flags(sb);
895 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
896 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
897 btrfs_set_super_incompat_flags(sb, features);
898 }
899
900 features = btrfs_super_compat_ro_flags(sb) &
901 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
902 if (writable && features) {
903 printk("couldn't open RDWR because of unsupported "
904 "option features (%Lx).\n",
905 (unsigned long long)features);
906 return -ENOTSUP;
907 }
908 return 0;
909 }
910
911 static int find_best_backup_root(struct btrfs_super_block *super)
912 {
913 struct btrfs_root_backup *backup;
914 u64 orig_gen = btrfs_super_generation(super);
915 u64 gen = 0;
916 int best_index = 0;
917 int i;
918
919 for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
920 backup = super->super_roots + i;
921 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
922 btrfs_backup_tree_root_gen(backup) > gen) {
923 best_index = i;
924 gen = btrfs_backup_tree_root_gen(backup);
925 }
926 }
927 return best_index;
928 }
929
930 static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
931 enum btrfs_open_ctree_flags flags,
932 struct btrfs_root *info_root,
933 u64 objectid, char *str)
934 {
935 struct btrfs_super_block *sb = fs_info->super_copy;
936 struct btrfs_root *root = fs_info->tree_root;
937 u32 leafsize = btrfs_super_leafsize(sb);
938 int ret;
939
940 ret = find_and_setup_root(root, fs_info, objectid, info_root);
941 if (ret) {
942 printk("Couldn't setup %s tree\n", str);
943 if (!(flags & OPEN_CTREE_PARTIAL))
944 return -EIO;
945 /*
946 * Need a blank node here just so we don't screw up in the
947 * million of places that assume a root has a valid ->node
948 */
949 info_root->node =
950 btrfs_find_create_tree_block(fs_info, 0, leafsize);
951 if (!info_root->node)
952 return -ENOMEM;
953 clear_extent_buffer_uptodate(NULL, info_root->node);
954 }
955
956 return 0;
957 }
958
959 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
960 enum btrfs_open_ctree_flags flags)
961 {
962 struct btrfs_super_block *sb = fs_info->super_copy;
963 struct btrfs_root *root;
964 struct btrfs_key key;
965 u32 sectorsize;
966 u32 nodesize;
967 u32 leafsize;
968 u32 stripesize;
969 u64 generation;
970 u32 blocksize;
971 int ret;
972
973 nodesize = btrfs_super_nodesize(sb);
974 leafsize = btrfs_super_leafsize(sb);
975 sectorsize = btrfs_super_sectorsize(sb);
976 stripesize = btrfs_super_stripesize(sb);
977
978 root = fs_info->tree_root;
979 __setup_root(nodesize, leafsize, sectorsize, stripesize,
980 root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
981 blocksize = btrfs_level_size(root, btrfs_super_root_level(sb));
982 generation = btrfs_super_generation(sb);
983
984 if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
985 root_tree_bytenr = btrfs_super_root(sb);
986 } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
987 struct btrfs_root_backup *backup;
988 int index = find_best_backup_root(sb);
989 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
990 fprintf(stderr, "Invalid backup root number\n");
991 return -EIO;
992 }
993 backup = fs_info->super_copy->super_roots + index;
994 root_tree_bytenr = btrfs_backup_tree_root(backup);
995 generation = btrfs_backup_tree_root_gen(backup);
996 }
997
998 root->node = read_tree_block(root, root_tree_bytenr, blocksize,
999 generation);
1000 if (!extent_buffer_uptodate(root->node)) {
1001 fprintf(stderr, "Couldn't read tree root\n");
1002 return -EIO;
1003 }
1004
1005 ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
1006 BTRFS_EXTENT_TREE_OBJECTID, "extent");
1007 if (ret)
1008 return ret;
1009 fs_info->extent_root->track_dirty = 1;
1010
1011 ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
1012 fs_info->dev_root);
1013 if (ret) {
1014 printk("Couldn't setup device tree\n");
1015 return -EIO;
1016 }
1017 fs_info->dev_root->track_dirty = 1;
1018
1019 ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
1020 BTRFS_CSUM_TREE_OBJECTID, "csum");
1021 if (ret)
1022 return ret;
1023 fs_info->csum_root->track_dirty = 1;
1024
1025 ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
1026 fs_info->quota_root);
1027 if (ret == 0)
1028 fs_info->quota_enabled = 1;
1029
1030 if (btrfs_fs_compat_ro(fs_info, BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE)) {
1031 ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID,
1032 fs_info->free_space_root);
1033 if (ret) {
1034 printk("Couldn't read free space tree\n");
1035 return -EIO;
1036 }
1037 fs_info->free_space_root->track_dirty = 1;
1038 }
1039
1040 ret = find_and_setup_log_root(root, fs_info, sb);
1041 if (ret) {
1042 printk("Couldn't setup log root tree\n");
1043 if (!(flags & OPEN_CTREE_PARTIAL))
1044 return -EIO;
1045 }
1046
1047 fs_info->generation = generation;
1048 fs_info->last_trans_committed = generation;
1049 if (extent_buffer_uptodate(fs_info->extent_root->node) &&
1050 !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
1051 btrfs_read_block_groups(fs_info->tree_root);
1052
1053 key.objectid = BTRFS_FS_TREE_OBJECTID;
1054 key.type = BTRFS_ROOT_ITEM_KEY;
1055 key.offset = (u64)-1;
1056 fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
1057
1058 if (IS_ERR(fs_info->fs_root))
1059 return -EIO;
1060 return 0;
1061 }
1062
1063 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
1064 {
1065 if (fs_info->free_space_root)
1066 free_extent_buffer(fs_info->free_space_root->node);
1067 if (fs_info->quota_root)
1068 free_extent_buffer(fs_info->quota_root->node);
1069 if (fs_info->csum_root)
1070 free_extent_buffer(fs_info->csum_root->node);
1071 if (fs_info->dev_root)
1072 free_extent_buffer(fs_info->dev_root->node);
1073 if (fs_info->extent_root)
1074 free_extent_buffer(fs_info->extent_root->node);
1075 if (fs_info->tree_root)
1076 free_extent_buffer(fs_info->tree_root->node);
1077 if (fs_info->log_root_tree)
1078 free_extent_buffer(fs_info->log_root_tree->node);
1079 if (fs_info->chunk_root)
1080 free_extent_buffer(fs_info->chunk_root->node);
1081 }
1082
1083 static void free_map_lookup(struct cache_extent *ce)
1084 {
1085 struct map_lookup *map;
1086
1087 map = container_of(ce, struct map_lookup, ce);
1088 kfree(map);
1089 }
1090
1091 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
1092
1093 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
1094 {
1095 while (!list_empty(&fs_info->recow_ebs)) {
1096 struct extent_buffer *eb;
1097 eb = list_first_entry(&fs_info->recow_ebs,
1098 struct extent_buffer, recow);
1099 list_del_init(&eb->recow);
1100 free_extent_buffer(eb);
1101 }
1102 free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
1103 extent_io_tree_cleanup(&fs_info->extent_cache);
1104 extent_io_tree_cleanup(&fs_info->free_space_cache);
1105 extent_io_tree_cleanup(&fs_info->block_group_cache);
1106 extent_io_tree_cleanup(&fs_info->pinned_extents);
1107 extent_io_tree_cleanup(&fs_info->pending_del);
1108 extent_io_tree_cleanup(&fs_info->extent_ins);
1109 }
1110
1111 int btrfs_scan_fs_devices(int fd, const char *path,
1112 struct btrfs_fs_devices **fs_devices,
1113 u64 sb_bytenr, int super_recover,
1114 int skip_devices)
1115 {
1116 u64 total_devs;
1117 u64 dev_size;
1118 off_t seek_ret;
1119 int ret;
1120 if (!sb_bytenr)
1121 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1122
1123 seek_ret = lseek(fd, 0, SEEK_END);
1124 if (seek_ret < 0)
1125 return -errno;
1126
1127 dev_size = seek_ret;
1128 lseek(fd, 0, SEEK_SET);
1129 if (sb_bytenr > dev_size) {
1130 fprintf(stderr, "Superblock bytenr is larger than device size\n");
1131 return -EINVAL;
1132 }
1133
1134 ret = btrfs_scan_one_device(fd, path, fs_devices,
1135 &total_devs, sb_bytenr, super_recover);
1136 if (ret) {
1137 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1138 return ret;
1139 }
1140
1141 if (!skip_devices && total_devs != 1) {
1142 ret = btrfs_scan_lblkid();
1143 if (ret)
1144 return ret;
1145 }
1146 return 0;
1147 }
1148
1149 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
1150 u64 chunk_root_bytenr)
1151 {
1152 struct btrfs_super_block *sb = fs_info->super_copy;
1153 u32 sectorsize;
1154 u32 nodesize;
1155 u32 leafsize;
1156 u32 blocksize;
1157 u32 stripesize;
1158 u64 generation;
1159 int ret;
1160
1161 nodesize = btrfs_super_nodesize(sb);
1162 leafsize = btrfs_super_leafsize(sb);
1163 sectorsize = btrfs_super_sectorsize(sb);
1164 stripesize = btrfs_super_stripesize(sb);
1165
1166 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1167 fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1168
1169 ret = btrfs_read_sys_array(fs_info->chunk_root);
1170 if (ret)
1171 return ret;
1172
1173 blocksize = btrfs_level_size(fs_info->chunk_root,
1174 btrfs_super_chunk_root_level(sb));
1175 generation = btrfs_super_chunk_root_generation(sb);
1176
1177 if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
1178 btrfs_super_sectorsize(sb))) {
1179 warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
1180 chunk_root_bytenr, btrfs_super_sectorsize(sb));
1181 chunk_root_bytenr = 0;
1182 }
1183
1184 if (!chunk_root_bytenr)
1185 chunk_root_bytenr = btrfs_super_chunk_root(sb);
1186 else
1187 generation = 0;
1188
1189 fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1190 chunk_root_bytenr,
1191 blocksize, generation);
1192 if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
1193 if (fs_info->ignore_chunk_tree_error) {
1194 warning("cannot read chunk root, continue anyway");
1195 fs_info->chunk_root = NULL;
1196 return 0;
1197 } else {
1198 error("cannot read chunk root");
1199 return -EIO;
1200 }
1201 }
1202
1203 if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1204 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1205 if (ret) {
1206 fprintf(stderr, "Couldn't read chunk tree\n");
1207 return ret;
1208 }
1209 }
1210 return 0;
1211 }
1212
1213 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1214 u64 sb_bytenr,
1215 u64 root_tree_bytenr,
1216 u64 chunk_root_bytenr,
1217 enum btrfs_open_ctree_flags flags)
1218 {
1219 struct btrfs_fs_info *fs_info;
1220 struct btrfs_super_block *disk_super;
1221 struct btrfs_fs_devices *fs_devices = NULL;
1222 struct extent_buffer *eb;
1223 int ret;
1224 int oflags;
1225
1226 if (sb_bytenr == 0)
1227 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1228
1229 /* try to drop all the caches */
1230 if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1231 fprintf(stderr, "Warning, could not drop caches\n");
1232
1233 fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1234 if (!fs_info) {
1235 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1236 return NULL;
1237 }
1238 if (flags & OPEN_CTREE_RESTORE)
1239 fs_info->on_restoring = 1;
1240 if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS)
1241 fs_info->suppress_check_block_errors = 1;
1242 if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
1243 fs_info->ignore_fsid_mismatch = 1;
1244 if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR)
1245 fs_info->ignore_chunk_tree_error = 1;
1246
1247 ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
1248 (flags & OPEN_CTREE_RECOVER_SUPER),
1249 (flags & OPEN_CTREE_NO_DEVICES));
1250 if (ret)
1251 goto out;
1252
1253 fs_info->fs_devices = fs_devices;
1254 if (flags & OPEN_CTREE_WRITES)
1255 oflags = O_RDWR;
1256 else
1257 oflags = O_RDONLY;
1258
1259 if (flags & OPEN_CTREE_EXCLUSIVE)
1260 oflags |= O_EXCL;
1261
1262 ret = btrfs_open_devices(fs_devices, oflags);
1263 if (ret)
1264 goto out;
1265
1266 disk_super = fs_info->super_copy;
1267 if (!(flags & OPEN_CTREE_RECOVER_SUPER))
1268 ret = btrfs_read_dev_super(fs_devices->latest_bdev,
1269 disk_super, sb_bytenr, 1);
1270 else
1271 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr, 0);
1272 if (ret) {
1273 printk("No valid btrfs found\n");
1274 goto out_devices;
1275 }
1276
1277 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID &&
1278 !fs_info->ignore_fsid_mismatch) {
1279 fprintf(stderr, "ERROR: Filesystem UUID change in progress\n");
1280 goto out_devices;
1281 }
1282
1283 memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1284
1285 ret = btrfs_check_fs_compatibility(fs_info->super_copy,
1286 flags & OPEN_CTREE_WRITES);
1287 if (ret)
1288 goto out_devices;
1289
1290 ret = btrfs_setup_chunk_tree_and_device_map(fs_info, chunk_root_bytenr);
1291 if (ret)
1292 goto out_chunk;
1293
1294 /* Chunk tree root is unable to read, return directly */
1295 if (!fs_info->chunk_root)
1296 return fs_info;
1297
1298 eb = fs_info->chunk_root->node;
1299 read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1300 btrfs_header_chunk_tree_uuid(eb),
1301 BTRFS_UUID_SIZE);
1302
1303 ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1304 if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) &&
1305 !fs_info->ignore_chunk_tree_error)
1306 goto out_chunk;
1307
1308 return fs_info;
1309
1310 out_chunk:
1311 btrfs_release_all_roots(fs_info);
1312 btrfs_cleanup_all_caches(fs_info);
1313 out_devices:
1314 btrfs_close_devices(fs_devices);
1315 out:
1316 btrfs_free_fs_info(fs_info);
1317 return NULL;
1318 }
1319
1320 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1321 u64 sb_bytenr, u64 root_tree_bytenr,
1322 u64 chunk_root_bytenr,
1323 enum btrfs_open_ctree_flags flags)
1324 {
1325 int fp;
1326 struct btrfs_fs_info *info;
1327 int oflags = O_CREAT | O_RDWR;
1328
1329 if (!(flags & OPEN_CTREE_WRITES))
1330 oflags = O_RDONLY;
1331
1332 fp = open(filename, oflags, 0600);
1333 if (fp < 0) {
1334 fprintf (stderr, "Could not open %s\n", filename);
1335 return NULL;
1336 }
1337 info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1338 chunk_root_bytenr, flags);
1339 close(fp);
1340 return info;
1341 }
1342
1343 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1344 enum btrfs_open_ctree_flags flags)
1345 {
1346 struct btrfs_fs_info *info;
1347
1348 /* This flags may not return fs_info with any valid root */
1349 BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
1350 info = open_ctree_fs_info(filename, sb_bytenr, 0, 0, flags);
1351 if (!info)
1352 return NULL;
1353 if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1354 return info->chunk_root;
1355 return info->fs_root;
1356 }
1357
1358 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1359 enum btrfs_open_ctree_flags flags)
1360 {
1361 struct btrfs_fs_info *info;
1362
1363 /* This flags may not return fs_info with any valid root */
1364 BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
1365 info = __open_ctree_fd(fp, path, sb_bytenr, 0, 0, flags);
1366 if (!info)
1367 return NULL;
1368 if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1369 return info->chunk_root;
1370 return info->fs_root;
1371 }
1372
1373 /*
1374 * Check if the super is valid:
1375 * - nodesize/sectorsize - minimum, maximum, alignment
1376 * - tree block starts - alignment
1377 * - number of devices - something sane
1378 * - sys array size - maximum
1379 */
1380 static int check_super(struct btrfs_super_block *sb)
1381 {
1382 char result[BTRFS_CSUM_SIZE];
1383 u32 crc;
1384 u16 csum_type;
1385 int csum_size;
1386
1387 if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
1388 fprintf(stderr, "ERROR: superblock magic doesn't match\n");
1389 return -EIO;
1390 }
1391
1392 csum_type = btrfs_super_csum_type(sb);
1393 if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
1394 fprintf(stderr, "ERROR: unsupported checksum algorithm %u\n",
1395 csum_type);
1396 return -EIO;
1397 }
1398 csum_size = btrfs_csum_sizes[csum_type];
1399
1400 crc = ~(u32)0;
1401 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1402 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1403 btrfs_csum_final(crc, result);
1404
1405 if (memcmp(result, sb->csum, csum_size)) {
1406 fprintf(stderr, "ERROR: superblock checksum mismatch\n");
1407 return -EIO;
1408 }
1409 if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
1410 fprintf(stderr, "ERROR: tree_root level too big: %d >= %d\n",
1411 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
1412 return -EIO;
1413 }
1414 if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
1415 fprintf(stderr, "ERROR: chunk_root level too big: %d >= %d\n",
1416 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
1417 return -EIO;
1418 }
1419 if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
1420 fprintf(stderr, "ERROR: log_root level too big: %d >= %d\n",
1421 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
1422 return -EIO;
1423 }
1424
1425 if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
1426 fprintf(stderr, "ERROR: tree_root block unaligned: %llu\n",
1427 btrfs_super_root(sb));
1428 return -EIO;
1429 }
1430 if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
1431 fprintf(stderr, "ERROR: chunk_root block unaligned: %llu\n",
1432 btrfs_super_chunk_root(sb));
1433 return -EIO;
1434 }
1435 if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
1436 fprintf(stderr, "ERROR: log_root block unaligned: %llu\n",
1437 btrfs_super_log_root(sb));
1438 return -EIO;
1439 }
1440 if (btrfs_super_nodesize(sb) < 4096) {
1441 fprintf(stderr, "ERROR: nodesize too small: %u < 4096\n",
1442 btrfs_super_nodesize(sb));
1443 return -EIO;
1444 }
1445 if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
1446 fprintf(stderr, "ERROR: nodesize unaligned: %u\n",
1447 btrfs_super_nodesize(sb));
1448 return -EIO;
1449 }
1450 if (btrfs_super_sectorsize(sb) < 4096) {
1451 fprintf(stderr, "ERROR: sectorsize too small: %u < 4096\n",
1452 btrfs_super_sectorsize(sb));
1453 return -EIO;
1454 }
1455 if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
1456 fprintf(stderr, "ERROR: sectorsize unaligned: %u\n",
1457 btrfs_super_sectorsize(sb));
1458 return -EIO;
1459 }
1460
1461 if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
1462 char fsid[BTRFS_UUID_UNPARSED_SIZE];
1463 char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
1464
1465 uuid_unparse(sb->fsid, fsid);
1466 uuid_unparse(sb->dev_item.fsid, dev_fsid);
1467 printk(KERN_ERR
1468 "ERROR: dev_item UUID does not match fsid: %s != %s\n",
1469 dev_fsid, fsid);
1470 return -EIO;
1471 }
1472
1473 /*
1474 * Hint to catch really bogus numbers, bitflips or so
1475 */
1476 if (btrfs_super_num_devices(sb) > (1UL << 31)) {
1477 fprintf(stderr, "WARNING: suspicious number of devices: %llu\n",
1478 btrfs_super_num_devices(sb));
1479 }
1480
1481 if (btrfs_super_num_devices(sb) == 0) {
1482 fprintf(stderr, "ERROR: number of devices is 0\n");
1483 return -EIO;
1484 }
1485
1486 /*
1487 * Obvious sys_chunk_array corruptions, it must hold at least one key
1488 * and one chunk
1489 */
1490 if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
1491 fprintf(stderr, "BTRFS: system chunk array too big %u > %u\n",
1492 btrfs_super_sys_array_size(sb),
1493 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
1494 return -EIO;
1495 }
1496 if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
1497 + sizeof(struct btrfs_chunk)) {
1498 fprintf(stderr, "BTRFS: system chunk array too small %u < %lu\n",
1499 btrfs_super_sys_array_size(sb),
1500 sizeof(struct btrfs_disk_key) +
1501 sizeof(struct btrfs_chunk));
1502 return -EIO;
1503 }
1504
1505 return 0;
1506 }
1507
1508 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1509 int super_recover)
1510 {
1511 u8 fsid[BTRFS_FSID_SIZE];
1512 int fsid_is_initialized = 0;
1513 char tmp[BTRFS_SUPER_INFO_SIZE];
1514 struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
1515 int i;
1516 int ret;
1517 int max_super = super_recover ? BTRFS_SUPER_MIRROR_MAX : 1;
1518 u64 transid = 0;
1519 u64 bytenr;
1520
1521 if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1522 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
1523 if (ret < BTRFS_SUPER_INFO_SIZE)
1524 return -1;
1525
1526 if (btrfs_super_bytenr(buf) != sb_bytenr)
1527 return -1;
1528
1529 if (check_super(buf))
1530 return -1;
1531 memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1532 return 0;
1533 }
1534
1535 /*
1536 * we would like to check all the supers, but that would make
1537 * a btrfs mount succeed after a mkfs from a different FS.
1538 * So, we need to add a special mount option to scan for
1539 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1540 */
1541
1542 for (i = 0; i < max_super; i++) {
1543 bytenr = btrfs_sb_offset(i);
1544 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr);
1545 if (ret < BTRFS_SUPER_INFO_SIZE)
1546 break;
1547
1548 if (btrfs_super_bytenr(buf) != bytenr )
1549 continue;
1550 /* if magic is NULL, the device was removed */
1551 if (btrfs_super_magic(buf) == 0 && i == 0)
1552 break;
1553 if (check_super(buf))
1554 continue;
1555
1556 if (!fsid_is_initialized) {
1557 memcpy(fsid, buf->fsid, sizeof(fsid));
1558 fsid_is_initialized = 1;
1559 } else if (memcmp(fsid, buf->fsid, sizeof(fsid))) {
1560 /*
1561 * the superblocks (the original one and
1562 * its backups) contain data of different
1563 * filesystems -> the super cannot be trusted
1564 */
1565 continue;
1566 }
1567
1568 if (btrfs_super_generation(buf) > transid) {
1569 memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1570 transid = btrfs_super_generation(buf);
1571 }
1572 }
1573
1574 return transid > 0 ? 0 : -1;
1575 }
1576
1577 static int write_dev_supers(struct btrfs_root *root,
1578 struct btrfs_super_block *sb,
1579 struct btrfs_device *device)
1580 {
1581 u64 bytenr;
1582 u32 crc;
1583 int i, ret;
1584
1585 if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1586 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1587 crc = ~(u32)0;
1588 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1589 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1590 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1591
1592 /*
1593 * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1594 * zero filled, we can use it directly
1595 */
1596 ret = pwrite64(device->fd, root->fs_info->super_copy,
1597 BTRFS_SUPER_INFO_SIZE,
1598 root->fs_info->super_bytenr);
1599 if (ret != BTRFS_SUPER_INFO_SIZE)
1600 goto write_err;
1601 return 0;
1602 }
1603
1604 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1605 bytenr = btrfs_sb_offset(i);
1606 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1607 break;
1608
1609 btrfs_set_super_bytenr(sb, bytenr);
1610
1611 crc = ~(u32)0;
1612 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1613 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1614 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1615
1616 /*
1617 * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1618 * zero filled, we can use it directly
1619 */
1620 ret = pwrite64(device->fd, root->fs_info->super_copy,
1621 BTRFS_SUPER_INFO_SIZE, bytenr);
1622 if (ret != BTRFS_SUPER_INFO_SIZE)
1623 goto write_err;
1624 }
1625
1626 return 0;
1627
1628 write_err:
1629 if (ret > 0)
1630 fprintf(stderr, "WARNING: failed to write all sb data\n");
1631 else
1632 fprintf(stderr, "WARNING: failed to write sb: %s\n",
1633 strerror(errno));
1634 return ret;
1635 }
1636
1637 int write_all_supers(struct btrfs_root *root)
1638 {
1639 struct list_head *cur;
1640 struct list_head *head = &root->fs_info->fs_devices->devices;
1641 struct btrfs_device *dev;
1642 struct btrfs_super_block *sb;
1643 struct btrfs_dev_item *dev_item;
1644 int ret;
1645 u64 flags;
1646
1647 sb = root->fs_info->super_copy;
1648 dev_item = &sb->dev_item;
1649 list_for_each(cur, head) {
1650 dev = list_entry(cur, struct btrfs_device, dev_list);
1651 if (!dev->writeable)
1652 continue;
1653
1654 btrfs_set_stack_device_generation(dev_item, 0);
1655 btrfs_set_stack_device_type(dev_item, dev->type);
1656 btrfs_set_stack_device_id(dev_item, dev->devid);
1657 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1658 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1659 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1660 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1661 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1662 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1663 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1664
1665 flags = btrfs_super_flags(sb);
1666 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1667
1668 ret = write_dev_supers(root, sb, dev);
1669 BUG_ON(ret);
1670 }
1671 return 0;
1672 }
1673
1674 int write_ctree_super(struct btrfs_trans_handle *trans,
1675 struct btrfs_root *root)
1676 {
1677 int ret;
1678 struct btrfs_root *tree_root = root->fs_info->tree_root;
1679 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1680
1681 if (root->fs_info->readonly)
1682 return 0;
1683
1684 btrfs_set_super_generation(root->fs_info->super_copy,
1685 trans->transid);
1686 btrfs_set_super_root(root->fs_info->super_copy,
1687 tree_root->node->start);
1688 btrfs_set_super_root_level(root->fs_info->super_copy,
1689 btrfs_header_level(tree_root->node));
1690 btrfs_set_super_chunk_root(root->fs_info->super_copy,
1691 chunk_root->node->start);
1692 btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1693 btrfs_header_level(chunk_root->node));
1694 btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1695 btrfs_header_generation(chunk_root->node));
1696
1697 ret = write_all_supers(root);
1698 if (ret)
1699 fprintf(stderr, "failed to write new super block err %d\n", ret);
1700 return ret;
1701 }
1702
1703 int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
1704 {
1705 int ret;
1706 struct btrfs_trans_handle *trans;
1707 struct btrfs_root *root = fs_info->tree_root;
1708
1709 if (fs_info->last_trans_committed !=
1710 fs_info->generation) {
1711 BUG_ON(!root);
1712 trans = btrfs_start_transaction(root, 1);
1713 btrfs_commit_transaction(trans, root);
1714 trans = btrfs_start_transaction(root, 1);
1715 ret = commit_tree_roots(trans, fs_info);
1716 BUG_ON(ret);
1717 ret = __commit_transaction(trans, root);
1718 BUG_ON(ret);
1719 write_ctree_super(trans, root);
1720 btrfs_free_transaction(root, trans);
1721 }
1722 btrfs_free_block_groups(fs_info);
1723
1724 free_fs_roots_tree(&fs_info->fs_root_tree);
1725
1726 btrfs_release_all_roots(fs_info);
1727 btrfs_close_devices(fs_info->fs_devices);
1728 btrfs_cleanup_all_caches(fs_info);
1729 btrfs_free_fs_info(fs_info);
1730 return 0;
1731 }
1732
1733 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1734 struct extent_buffer *eb)
1735 {
1736 return clear_extent_buffer_dirty(eb);
1737 }
1738
1739 int wait_on_tree_block_writeback(struct btrfs_root *root,
1740 struct extent_buffer *eb)
1741 {
1742 return 0;
1743 }
1744
1745 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1746 {
1747 set_extent_buffer_dirty(eb);
1748 }
1749
1750 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1751 {
1752 int ret;
1753
1754 ret = extent_buffer_uptodate(buf);
1755 if (!ret)
1756 return ret;
1757
1758 ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1759 return !ret;
1760 }
1761
1762 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1763 {
1764 return set_extent_buffer_uptodate(eb);
1765 }
(deprecated) Btrfs progs developments and patch integration