btrfs-progs: drop unused argument from btrfs_del_ptr
[platform/upstream/btrfs-progs.git] / disk-io.c
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 nodesize = btrfs_super_nodesize(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                                                     nodesize))
68                 return BTRFS_BAD_NRITEMS;
69
70         /* Only leaf can be empty */
71         if (btrfs_header_nritems(buf) == 0 &&
72             btrfs_header_level(buf) != 0)
73                 return BTRFS_BAD_NRITEMS;
74
75         fs_devices = fs_info->fs_devices;
76         while (fs_devices) {
77                 if (fs_info->ignore_fsid_mismatch ||
78                     !memcmp_extent_buffer(buf, fs_devices->fsid,
79                                           btrfs_header_fsid(),
80                                           BTRFS_FSID_SIZE)) {
81                         ret = 0;
82                         break;
83                 }
84                 fs_devices = fs_devices->seed;
85         }
86         return ret;
87 }
88
89 static void print_tree_block_error(struct btrfs_fs_info *fs_info,
90                                 struct extent_buffer *eb,
91                                 int err)
92 {
93         char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
94         char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
95         u8 buf[BTRFS_UUID_SIZE];
96
97         switch (err) {
98         case BTRFS_BAD_FSID:
99                 read_extent_buffer(eb, buf, btrfs_header_fsid(),
100                                    BTRFS_UUID_SIZE);
101                 uuid_unparse(buf, found_uuid);
102                 uuid_unparse(fs_info->fsid, fs_uuid);
103                 fprintf(stderr, "fsid mismatch, want=%s, have=%s\n",
104                         fs_uuid, found_uuid);
105                 break;
106         case BTRFS_BAD_BYTENR:
107                 fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n",
108                         eb->start, btrfs_header_bytenr(eb));
109                 break;
110         case BTRFS_BAD_LEVEL:
111                 fprintf(stderr, "bad level, %u > %u\n",
112                         btrfs_header_level(eb), BTRFS_MAX_LEVEL);
113                 break;
114         case BTRFS_BAD_NRITEMS:
115                 fprintf(stderr, "invalid nr_items: %u\n",
116                         btrfs_header_nritems(eb));
117                 break;
118         }
119 }
120
121 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
122 {
123         return crc32c(seed, data, len);
124 }
125
126 void btrfs_csum_final(u32 crc, u8 *result)
127 {
128         put_unaligned_le32(~crc, result);
129 }
130
131 static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
132                                   int verify, int silent)
133 {
134         u8 result[BTRFS_CSUM_SIZE];
135         u32 len;
136         u32 crc = ~(u32)0;
137
138         len = buf->len - BTRFS_CSUM_SIZE;
139         crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
140         btrfs_csum_final(crc, result);
141
142         if (verify) {
143                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
144                         if (!silent)
145                                 printk("checksum verify failed on %llu found %08X wanted %08X\n",
146                                        (unsigned long long)buf->start,
147                                        *((u32 *)result),
148                                        *((u32*)(char *)buf->data));
149                         return 1;
150                 }
151         } else {
152                 write_extent_buffer(buf, result, 0, csum_size);
153         }
154         return 0;
155 }
156
157 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
158 {
159         return __csum_tree_block_size(buf, csum_size, verify, 0);
160 }
161
162 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
163 {
164         return __csum_tree_block_size(buf, csum_size, 1, 1);
165 }
166
167 static int csum_tree_block_fs_info(struct btrfs_fs_info *fs_info,
168                                    struct extent_buffer *buf, int verify)
169 {
170         u16 csum_size =
171                 btrfs_super_csum_size(fs_info->super_copy);
172         if (verify && fs_info->suppress_check_block_errors)
173                 return verify_tree_block_csum_silent(buf, csum_size);
174         return csum_tree_block_size(buf, csum_size, verify);
175 }
176
177 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
178                            int verify)
179 {
180         return csum_tree_block_fs_info(root->fs_info, buf, verify);
181 }
182
183 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
184                                             u64 bytenr, u32 blocksize)
185 {
186         return find_extent_buffer(&root->fs_info->extent_cache,
187                                   bytenr, blocksize);
188 }
189
190 struct extent_buffer* btrfs_find_create_tree_block(
191                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize)
192 {
193         return alloc_extent_buffer(&fs_info->extent_cache, bytenr, blocksize);
194 }
195
196 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
197                           u64 parent_transid)
198 {
199         struct extent_buffer *eb;
200         u64 length;
201         struct btrfs_multi_bio *multi = NULL;
202         struct btrfs_device *device;
203
204         eb = btrfs_find_tree_block(root, bytenr, blocksize);
205         if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
206             !btrfs_map_block(&root->fs_info->mapping_tree, READ,
207                              bytenr, &length, &multi, 0, NULL)) {
208                 device = multi->stripes[0].dev;
209                 device->total_ios++;
210                 blocksize = min(blocksize, (u32)SZ_64K);
211                 readahead(device->fd, multi->stripes[0].physical, blocksize);
212         }
213
214         free_extent_buffer(eb);
215         kfree(multi);
216 }
217
218 static int verify_parent_transid(struct extent_io_tree *io_tree,
219                                  struct extent_buffer *eb, u64 parent_transid,
220                                  int ignore)
221 {
222         int ret;
223
224         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
225                 return 0;
226
227         if (extent_buffer_uptodate(eb) &&
228             btrfs_header_generation(eb) == parent_transid) {
229                 ret = 0;
230                 goto out;
231         }
232         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
233                (unsigned long long)eb->start,
234                (unsigned long long)parent_transid,
235                (unsigned long long)btrfs_header_generation(eb));
236         if (ignore) {
237                 eb->flags |= EXTENT_BAD_TRANSID;
238                 printk("Ignoring transid failure\n");
239                 return 0;
240         }
241
242         ret = 1;
243 out:
244         clear_extent_buffer_uptodate(eb);
245         return ret;
246
247 }
248
249
250 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
251 {
252         unsigned long offset = 0;
253         struct btrfs_multi_bio *multi = NULL;
254         struct btrfs_device *device;
255         int ret = 0;
256         u64 read_len;
257         unsigned long bytes_left = eb->len;
258
259         while (bytes_left) {
260                 read_len = bytes_left;
261                 device = NULL;
262
263                 if (!info->on_restoring &&
264                     eb->start != BTRFS_SUPER_INFO_OFFSET) {
265                         ret = btrfs_map_block(&info->mapping_tree, READ,
266                                               eb->start + offset, &read_len, &multi,
267                                               mirror, NULL);
268                         if (ret) {
269                                 printk("Couldn't map the block %Lu\n", eb->start + offset);
270                                 kfree(multi);
271                                 return -EIO;
272                         }
273                         device = multi->stripes[0].dev;
274
275                         if (device->fd <= 0) {
276                                 kfree(multi);
277                                 return -EIO;
278                         }
279
280                         eb->fd = device->fd;
281                         device->total_ios++;
282                         eb->dev_bytenr = multi->stripes[0].physical;
283                         kfree(multi);
284                         multi = NULL;
285                 } else {
286                         /* special case for restore metadump */
287                         list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
288                                 if (device->devid == 1)
289                                         break;
290                         }
291
292                         eb->fd = device->fd;
293                         eb->dev_bytenr = eb->start;
294                         device->total_ios++;
295                 }
296
297                 if (read_len > bytes_left)
298                         read_len = bytes_left;
299
300                 ret = read_extent_from_disk(eb, offset, read_len);
301                 if (ret)
302                         return -EIO;
303                 offset += read_len;
304                 bytes_left -= read_len;
305         }
306         return 0;
307 }
308
309 struct extent_buffer* read_tree_block_fs_info(
310                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
311                 u64 parent_transid)
312 {
313         int ret;
314         struct extent_buffer *eb;
315         u64 best_transid = 0;
316         u32 sectorsize = btrfs_super_sectorsize(fs_info->super_copy);
317         u32 nodesize = btrfs_super_nodesize(fs_info->super_copy);
318         int mirror_num = 0;
319         int good_mirror = 0;
320         int num_copies;
321         int ignore = 0;
322
323         /*
324          * Don't even try to create tree block for unaligned tree block
325          * bytenr.
326          * Such unaligned tree block will free overlapping extent buffer,
327          * causing use-after-free bugs for fuzzed images.
328          */
329         if (bytenr < sectorsize || !IS_ALIGNED(bytenr, sectorsize)) {
330                 error("tree block bytenr %llu is not aligned to sectorsize %u",
331                       bytenr, sectorsize);
332                 return ERR_PTR(-EIO);
333         }
334         if (blocksize < nodesize || !IS_ALIGNED(blocksize, nodesize)) {
335                 error("tree block size %u is not aligned to nodesize %u",
336                       blocksize, nodesize);
337                 return ERR_PTR(-EIO);
338         }
339
340         eb = btrfs_find_create_tree_block(fs_info, bytenr, blocksize);
341         if (!eb)
342                 return ERR_PTR(-ENOMEM);
343
344         if (btrfs_buffer_uptodate(eb, parent_transid))
345                 return eb;
346
347         while (1) {
348                 ret = read_whole_eb(fs_info, eb, mirror_num);
349                 if (ret == 0 && csum_tree_block_fs_info(fs_info, eb, 1) == 0 &&
350                     check_tree_block(fs_info, eb) == 0 &&
351                     verify_parent_transid(eb->tree, eb, parent_transid, ignore)
352                     == 0) {
353                         if (eb->flags & EXTENT_BAD_TRANSID &&
354                             list_empty(&eb->recow)) {
355                                 list_add_tail(&eb->recow,
356                                               &fs_info->recow_ebs);
357                                 eb->refs++;
358                         }
359                         btrfs_set_buffer_uptodate(eb);
360                         return eb;
361                 }
362                 if (ignore) {
363                         if (check_tree_block(fs_info, eb)) {
364                                 if (!fs_info->suppress_check_block_errors)
365                                         print_tree_block_error(fs_info, eb,
366                                                 check_tree_block(fs_info, eb));
367                         } else {
368                                 if (!fs_info->suppress_check_block_errors)
369                                         fprintf(stderr, "Csum didn't match\n");
370                         }
371                         ret = -EIO;
372                         break;
373                 }
374                 num_copies = btrfs_num_copies(&fs_info->mapping_tree,
375                                               eb->start, eb->len);
376                 if (num_copies == 1) {
377                         ignore = 1;
378                         continue;
379                 }
380                 if (btrfs_header_generation(eb) > best_transid && mirror_num) {
381                         best_transid = btrfs_header_generation(eb);
382                         good_mirror = mirror_num;
383                 }
384                 mirror_num++;
385                 if (mirror_num > num_copies) {
386                         mirror_num = good_mirror;
387                         ignore = 1;
388                         continue;
389                 }
390         }
391         free_extent_buffer(eb);
392         return ERR_PTR(ret);
393 }
394
395 int read_extent_data(struct btrfs_root *root, char *data,
396                            u64 logical, u64 *len, int mirror)
397 {
398         u64 offset = 0;
399         struct btrfs_multi_bio *multi = NULL;
400         struct btrfs_fs_info *info = root->fs_info;
401         struct btrfs_device *device;
402         int ret = 0;
403         u64 max_len = *len;
404
405         ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
406                               &multi, mirror, NULL);
407         if (ret) {
408                 fprintf(stderr, "Couldn't map the block %llu\n",
409                                 logical + offset);
410                 goto err;
411         }
412         device = multi->stripes[0].dev;
413
414         if (device->fd <= 0)
415                 goto err;
416         if (*len > max_len)
417                 *len = max_len;
418
419         ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
420         if (ret != *len)
421                 ret = -EIO;
422         else
423                 ret = 0;
424 err:
425         kfree(multi);
426         return ret;
427 }
428
429 int write_and_map_eb(struct btrfs_trans_handle *trans,
430                      struct btrfs_root *root,
431                      struct extent_buffer *eb)
432 {
433         int ret;
434         int dev_nr;
435         u64 length;
436         u64 *raid_map = NULL;
437         struct btrfs_multi_bio *multi = NULL;
438
439         dev_nr = 0;
440         length = eb->len;
441         ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
442                               eb->start, &length, &multi, 0, &raid_map);
443
444         if (raid_map) {
445                 ret = write_raid56_with_parity(root->fs_info, eb, multi,
446                                                length, raid_map);
447                 BUG_ON(ret);
448         } else while (dev_nr < multi->num_stripes) {
449                 BUG_ON(ret);
450                 eb->fd = multi->stripes[dev_nr].dev->fd;
451                 eb->dev_bytenr = multi->stripes[dev_nr].physical;
452                 multi->stripes[dev_nr].dev->total_ios++;
453                 dev_nr++;
454                 ret = write_extent_to_disk(eb);
455                 BUG_ON(ret);
456         }
457         kfree(raid_map);
458         kfree(multi);
459         return 0;
460 }
461
462 int write_tree_block(struct btrfs_trans_handle *trans,
463                      struct btrfs_root *root,
464                      struct extent_buffer *eb)
465 {
466         if (check_tree_block(root->fs_info, eb)) {
467                 print_tree_block_error(root->fs_info, eb,
468                                 check_tree_block(root->fs_info, eb));
469                 BUG();
470         }
471
472         if (trans && !btrfs_buffer_uptodate(eb, trans->transid))
473                 BUG();
474
475         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
476         csum_tree_block(root, eb, 0);
477
478         return write_and_map_eb(trans, root, eb);
479 }
480
481 void btrfs_setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
482                         u32 stripesize, struct btrfs_root *root,
483                         struct btrfs_fs_info *fs_info, u64 objectid)
484 {
485         root->node = NULL;
486         root->commit_root = NULL;
487         root->sectorsize = sectorsize;
488         root->nodesize = nodesize;
489         root->leafsize = leafsize;
490         root->stripesize = stripesize;
491         root->ref_cows = 0;
492         root->track_dirty = 0;
493
494         root->fs_info = fs_info;
495         root->objectid = objectid;
496         root->last_trans = 0;
497         root->last_inode_alloc = 0;
498
499         INIT_LIST_HEAD(&root->dirty_list);
500         INIT_LIST_HEAD(&root->orphan_data_extents);
501         memset(&root->root_key, 0, sizeof(root->root_key));
502         memset(&root->root_item, 0, sizeof(root->root_item));
503         root->root_key.objectid = objectid;
504 }
505
506 static int update_cowonly_root(struct btrfs_trans_handle *trans,
507                                struct btrfs_root *root)
508 {
509         int ret;
510         u64 old_root_bytenr;
511         struct btrfs_root *tree_root = root->fs_info->tree_root;
512
513         btrfs_write_dirty_block_groups(trans, root);
514         while(1) {
515                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
516                 if (old_root_bytenr == root->node->start)
517                         break;
518                 btrfs_set_root_bytenr(&root->root_item,
519                                        root->node->start);
520                 btrfs_set_root_generation(&root->root_item,
521                                           trans->transid);
522                 root->root_item.level = btrfs_header_level(root->node);
523                 ret = btrfs_update_root(trans, tree_root,
524                                         &root->root_key,
525                                         &root->root_item);
526                 BUG_ON(ret);
527                 btrfs_write_dirty_block_groups(trans, root);
528         }
529         return 0;
530 }
531
532 static int commit_tree_roots(struct btrfs_trans_handle *trans,
533                              struct btrfs_fs_info *fs_info)
534 {
535         struct btrfs_root *root;
536         struct list_head *next;
537         struct extent_buffer *eb;
538         int ret;
539
540         if (fs_info->readonly)
541                 return 0;
542
543         eb = fs_info->tree_root->node;
544         extent_buffer_get(eb);
545         ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
546         free_extent_buffer(eb);
547         if (ret)
548                 return ret;
549
550         while(!list_empty(&fs_info->dirty_cowonly_roots)) {
551                 next = fs_info->dirty_cowonly_roots.next;
552                 list_del_init(next);
553                 root = list_entry(next, struct btrfs_root, dirty_list);
554                 update_cowonly_root(trans, root);
555                 free_extent_buffer(root->commit_root);
556                 root->commit_root = NULL;
557         }
558
559         return 0;
560 }
561
562 static int __commit_transaction(struct btrfs_trans_handle *trans,
563                                 struct btrfs_root *root)
564 {
565         u64 start;
566         u64 end;
567         struct extent_buffer *eb;
568         struct extent_io_tree *tree = &root->fs_info->extent_cache;
569         int ret;
570
571         while(1) {
572                 ret = find_first_extent_bit(tree, 0, &start, &end,
573                                             EXTENT_DIRTY);
574                 if (ret)
575                         break;
576                 while(start <= end) {
577                         eb = find_first_extent_buffer(tree, start);
578                         BUG_ON(!eb || eb->start != start);
579                         ret = write_tree_block(trans, root, eb);
580                         BUG_ON(ret);
581                         start += eb->len;
582                         clear_extent_buffer_dirty(eb);
583                         free_extent_buffer(eb);
584                 }
585         }
586         return 0;
587 }
588
589 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
590                              struct btrfs_root *root)
591 {
592         u64 transid = trans->transid;
593         int ret = 0;
594         struct btrfs_fs_info *fs_info = root->fs_info;
595
596         if (root->commit_root == root->node)
597                 goto commit_tree;
598         if (root == root->fs_info->tree_root)
599                 goto commit_tree;
600         if (root == root->fs_info->chunk_root)
601                 goto commit_tree;
602
603         free_extent_buffer(root->commit_root);
604         root->commit_root = NULL;
605
606         btrfs_set_root_bytenr(&root->root_item, root->node->start);
607         btrfs_set_root_generation(&root->root_item, trans->transid);
608         root->root_item.level = btrfs_header_level(root->node);
609         ret = btrfs_update_root(trans, root->fs_info->tree_root,
610                                 &root->root_key, &root->root_item);
611         BUG_ON(ret);
612 commit_tree:
613         ret = commit_tree_roots(trans, fs_info);
614         BUG_ON(ret);
615         ret = __commit_transaction(trans, root);
616         BUG_ON(ret);
617         write_ctree_super(trans, root);
618         btrfs_finish_extent_commit(trans, fs_info->extent_root,
619                                    &fs_info->pinned_extents);
620         btrfs_free_transaction(root, trans);
621         free_extent_buffer(root->commit_root);
622         root->commit_root = NULL;
623         fs_info->running_transaction = NULL;
624         fs_info->last_trans_committed = transid;
625         return 0;
626 }
627
628 static int find_and_setup_root(struct btrfs_root *tree_root,
629                                struct btrfs_fs_info *fs_info,
630                                u64 objectid, struct btrfs_root *root)
631 {
632         int ret;
633         u32 blocksize;
634         u64 generation;
635
636         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
637                      tree_root->sectorsize, tree_root->stripesize,
638                      root, fs_info, objectid);
639         ret = btrfs_find_last_root(tree_root, objectid,
640                                    &root->root_item, &root->root_key);
641         if (ret)
642                 return ret;
643
644         blocksize = root->nodesize;
645         generation = btrfs_root_generation(&root->root_item);
646         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
647                                      blocksize, generation);
648         if (!extent_buffer_uptodate(root->node))
649                 return -EIO;
650
651         return 0;
652 }
653
654 static int find_and_setup_log_root(struct btrfs_root *tree_root,
655                                struct btrfs_fs_info *fs_info,
656                                struct btrfs_super_block *disk_super)
657 {
658         u32 blocksize;
659         u64 blocknr = btrfs_super_log_root(disk_super);
660         struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
661
662         if (!log_root)
663                 return -ENOMEM;
664
665         if (blocknr == 0) {
666                 free(log_root);
667                 return 0;
668         }
669
670         blocksize = tree_root->nodesize;
671
672         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
673                      tree_root->sectorsize, tree_root->stripesize,
674                      log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
675
676         log_root->node = read_tree_block(tree_root, blocknr,
677                                      blocksize,
678                                      btrfs_super_generation(disk_super) + 1);
679
680         fs_info->log_root_tree = log_root;
681
682         if (!extent_buffer_uptodate(log_root->node)) {
683                 free_extent_buffer(log_root->node);
684                 free(log_root);
685                 fs_info->log_root_tree = NULL;
686                 return -EIO;
687         }
688
689         return 0;
690 }
691
692 int btrfs_free_fs_root(struct btrfs_root *root)
693 {
694         if (root->node)
695                 free_extent_buffer(root->node);
696         if (root->commit_root)
697                 free_extent_buffer(root->commit_root);
698         kfree(root);
699         return 0;
700 }
701
702 static void __free_fs_root(struct rb_node *node)
703 {
704         struct btrfs_root *root;
705
706         root = container_of(node, struct btrfs_root, rb_node);
707         btrfs_free_fs_root(root);
708 }
709
710 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
711
712 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
713                                                struct btrfs_key *location)
714 {
715         struct btrfs_root *root;
716         struct btrfs_root *tree_root = fs_info->tree_root;
717         struct btrfs_path *path;
718         struct extent_buffer *l;
719         u64 generation;
720         u32 blocksize;
721         int ret = 0;
722
723         root = calloc(1, sizeof(*root));
724         if (!root)
725                 return ERR_PTR(-ENOMEM);
726         if (location->offset == (u64)-1) {
727                 ret = find_and_setup_root(tree_root, fs_info,
728                                           location->objectid, root);
729                 if (ret) {
730                         free(root);
731                         return ERR_PTR(ret);
732                 }
733                 goto insert;
734         }
735
736         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
737                      tree_root->sectorsize, tree_root->stripesize,
738                      root, fs_info, location->objectid);
739
740         path = btrfs_alloc_path();
741         if (!path) {
742                 free(root);
743                 return ERR_PTR(-ENOMEM);
744         }
745
746         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
747         if (ret != 0) {
748                 if (ret > 0)
749                         ret = -ENOENT;
750                 goto out;
751         }
752         l = path->nodes[0];
753         read_extent_buffer(l, &root->root_item,
754                btrfs_item_ptr_offset(l, path->slots[0]),
755                sizeof(root->root_item));
756         memcpy(&root->root_key, location, sizeof(*location));
757         ret = 0;
758 out:
759         btrfs_free_path(path);
760         if (ret) {
761                 free(root);
762                 return ERR_PTR(ret);
763         }
764         generation = btrfs_root_generation(&root->root_item);
765         blocksize = root->nodesize;
766         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
767                                      blocksize, generation);
768         if (!extent_buffer_uptodate(root->node)) {
769                 free(root);
770                 return ERR_PTR(-EIO);
771         }
772 insert:
773         root->ref_cows = 1;
774         return root;
775 }
776
777 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
778                                             void *data)
779 {
780         u64 objectid = *((u64 *)data);
781         struct btrfs_root *root;
782
783         root = rb_entry(node, struct btrfs_root, rb_node);
784         if (objectid > root->objectid)
785                 return 1;
786         else if (objectid < root->objectid)
787                 return -1;
788         else
789                 return 0;
790 }
791
792 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
793                                         struct rb_node *node2)
794 {
795         struct btrfs_root *root;
796
797         root = rb_entry(node2, struct btrfs_root, rb_node);
798         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
799 }
800
801 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
802                                       struct btrfs_key *location)
803 {
804         struct btrfs_root *root;
805         struct rb_node *node;
806         int ret;
807         u64 objectid = location->objectid;
808
809         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
810                 return fs_info->tree_root;
811         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
812                 return fs_info->extent_root;
813         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
814                 return fs_info->chunk_root;
815         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
816                 return fs_info->dev_root;
817         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
818                 return fs_info->csum_root;
819         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
820                 return fs_info->quota_root;
821
822         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
823                location->offset != (u64)-1);
824
825         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
826                          btrfs_fs_roots_compare_objectids, NULL);
827         if (node)
828                 return container_of(node, struct btrfs_root, rb_node);
829
830         root = btrfs_read_fs_root_no_cache(fs_info, location);
831         if (IS_ERR(root))
832                 return root;
833
834         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
835                         btrfs_fs_roots_compare_roots);
836         BUG_ON(ret);
837         return root;
838 }
839
840 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
841 {
842         free(fs_info->tree_root);
843         free(fs_info->extent_root);
844         free(fs_info->chunk_root);
845         free(fs_info->dev_root);
846         free(fs_info->csum_root);
847         free(fs_info->quota_root);
848         free(fs_info->free_space_root);
849         free(fs_info->super_copy);
850         free(fs_info->log_root_tree);
851         free(fs_info);
852 }
853
854 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
855 {
856         struct btrfs_fs_info *fs_info;
857
858         fs_info = calloc(1, sizeof(struct btrfs_fs_info));
859         if (!fs_info)
860                 return NULL;
861
862         fs_info->tree_root = calloc(1, sizeof(struct btrfs_root));
863         fs_info->extent_root = calloc(1, sizeof(struct btrfs_root));
864         fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root));
865         fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
866         fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
867         fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
868         fs_info->free_space_root = calloc(1, sizeof(struct btrfs_root));
869         fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
870
871         if (!fs_info->tree_root || !fs_info->extent_root ||
872             !fs_info->chunk_root || !fs_info->dev_root ||
873             !fs_info->csum_root || !fs_info->quota_root ||
874             !fs_info->free_space_root || !fs_info->super_copy)
875                 goto free_all;
876
877         extent_io_tree_init(&fs_info->extent_cache);
878         extent_io_tree_init(&fs_info->free_space_cache);
879         extent_io_tree_init(&fs_info->block_group_cache);
880         extent_io_tree_init(&fs_info->pinned_extents);
881         extent_io_tree_init(&fs_info->pending_del);
882         extent_io_tree_init(&fs_info->extent_ins);
883         fs_info->excluded_extents = NULL;
884
885         fs_info->fs_root_tree = RB_ROOT;
886         cache_tree_init(&fs_info->mapping_tree.cache_tree);
887
888         mutex_init(&fs_info->fs_mutex);
889         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
890         INIT_LIST_HEAD(&fs_info->space_info);
891         INIT_LIST_HEAD(&fs_info->recow_ebs);
892
893         if (!writable)
894                 fs_info->readonly = 1;
895
896         fs_info->super_bytenr = sb_bytenr;
897         fs_info->data_alloc_profile = (u64)-1;
898         fs_info->metadata_alloc_profile = (u64)-1;
899         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
900         return fs_info;
901 free_all:
902         btrfs_free_fs_info(fs_info);
903         return NULL;
904 }
905
906 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb,
907                                  unsigned int flags)
908 {
909         u64 features;
910
911         features = btrfs_super_incompat_flags(sb) &
912                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
913         if (features) {
914                 printk("couldn't open because of unsupported "
915                        "option features (%Lx).\n",
916                        (unsigned long long)features);
917                 return -ENOTSUP;
918         }
919
920         features = btrfs_super_incompat_flags(sb);
921         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
922                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
923                 btrfs_set_super_incompat_flags(sb, features);
924         }
925
926         features = btrfs_super_compat_ro_flags(sb);
927         if (flags & OPEN_CTREE_WRITES) {
928                 if (flags & OPEN_CTREE_INVALIDATE_FST) {
929                         /* Clear the FREE_SPACE_TREE_VALID bit on disk... */
930                         features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID;
931                         btrfs_set_super_compat_ro_flags(sb, features);
932                         /* ... and ignore the free space tree bit. */
933                         features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE;
934                 }
935                 if (features & ~BTRFS_FEATURE_COMPAT_RO_SUPP) {
936                         printk("couldn't open RDWR because of unsupported "
937                                "option features (%Lx).\n",
938                                (unsigned long long)features);
939                         return -ENOTSUP;
940                 }
941
942         }
943         return 0;
944 }
945
946 static int find_best_backup_root(struct btrfs_super_block *super)
947 {
948         struct btrfs_root_backup *backup;
949         u64 orig_gen = btrfs_super_generation(super);
950         u64 gen = 0;
951         int best_index = 0;
952         int i;
953
954         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
955                 backup = super->super_roots + i;
956                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
957                     btrfs_backup_tree_root_gen(backup) > gen) {
958                         best_index = i;
959                         gen = btrfs_backup_tree_root_gen(backup);
960                 }
961         }
962         return best_index;
963 }
964
965 static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
966                                       unsigned flags,
967                                       struct btrfs_root *info_root,
968                                       u64 objectid, char *str)
969 {
970         struct btrfs_super_block *sb = fs_info->super_copy;
971         struct btrfs_root *root = fs_info->tree_root;
972         u32 nodesize = btrfs_super_nodesize(sb);
973         int ret;
974
975         ret = find_and_setup_root(root, fs_info, objectid, info_root);
976         if (ret) {
977                 printk("Couldn't setup %s tree\n", str);
978                 if (!(flags & OPEN_CTREE_PARTIAL))
979                         return -EIO;
980                 /*
981                  * Need a blank node here just so we don't screw up in the
982                  * million of places that assume a root has a valid ->node
983                  */
984                 info_root->node =
985                         btrfs_find_create_tree_block(fs_info, 0, nodesize);
986                 if (!info_root->node)
987                         return -ENOMEM;
988                 clear_extent_buffer_uptodate(info_root->node);
989         }
990
991         return 0;
992 }
993
994 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
995                           unsigned flags)
996 {
997         struct btrfs_super_block *sb = fs_info->super_copy;
998         struct btrfs_root *root;
999         struct btrfs_key key;
1000         u32 sectorsize;
1001         u32 nodesize;
1002         u32 leafsize;
1003         u32 stripesize;
1004         u64 generation;
1005         u32 blocksize;
1006         int ret;
1007
1008         nodesize = btrfs_super_nodesize(sb);
1009         leafsize = btrfs_super_leafsize(sb);
1010         sectorsize = btrfs_super_sectorsize(sb);
1011         stripesize = btrfs_super_stripesize(sb);
1012
1013         root = fs_info->tree_root;
1014         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1015                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1016         blocksize = root->nodesize;
1017         generation = btrfs_super_generation(sb);
1018
1019         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
1020                 root_tree_bytenr = btrfs_super_root(sb);
1021         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
1022                 struct btrfs_root_backup *backup;
1023                 int index = find_best_backup_root(sb);
1024                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
1025                         fprintf(stderr, "Invalid backup root number\n");
1026                         return -EIO;
1027                 }
1028                 backup = fs_info->super_copy->super_roots + index;
1029                 root_tree_bytenr = btrfs_backup_tree_root(backup);
1030                 generation = btrfs_backup_tree_root_gen(backup);
1031         }
1032
1033         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
1034                                      generation);
1035         if (!extent_buffer_uptodate(root->node)) {
1036                 fprintf(stderr, "Couldn't read tree root\n");
1037                 return -EIO;
1038         }
1039
1040         ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
1041                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
1042         if (ret)
1043                 return ret;
1044         fs_info->extent_root->track_dirty = 1;
1045
1046         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
1047                                   fs_info->dev_root);
1048         if (ret) {
1049                 printk("Couldn't setup device tree\n");
1050                 return -EIO;
1051         }
1052         fs_info->dev_root->track_dirty = 1;
1053
1054         ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
1055                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
1056         if (ret)
1057                 return ret;
1058         fs_info->csum_root->track_dirty = 1;
1059
1060         ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
1061                                   fs_info->quota_root);
1062         if (ret == 0)
1063                 fs_info->quota_enabled = 1;
1064
1065         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1066                 ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID,
1067                                           fs_info->free_space_root);
1068                 if (ret) {
1069                         printk("Couldn't read free space tree\n");
1070                         return -EIO;
1071                 }
1072                 fs_info->free_space_root->track_dirty = 1;
1073         }
1074
1075         ret = find_and_setup_log_root(root, fs_info, sb);
1076         if (ret) {
1077                 printk("Couldn't setup log root tree\n");
1078                 if (!(flags & OPEN_CTREE_PARTIAL))
1079                         return -EIO;
1080         }
1081
1082         fs_info->generation = generation;
1083         fs_info->last_trans_committed = generation;
1084         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
1085             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
1086                 btrfs_read_block_groups(fs_info->tree_root);
1087
1088         key.objectid = BTRFS_FS_TREE_OBJECTID;
1089         key.type = BTRFS_ROOT_ITEM_KEY;
1090         key.offset = (u64)-1;
1091         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
1092
1093         if (IS_ERR(fs_info->fs_root))
1094                 return -EIO;
1095         return 0;
1096 }
1097
1098 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
1099 {
1100         if (fs_info->free_space_root)
1101                 free_extent_buffer(fs_info->free_space_root->node);
1102         if (fs_info->quota_root)
1103                 free_extent_buffer(fs_info->quota_root->node);
1104         if (fs_info->csum_root)
1105                 free_extent_buffer(fs_info->csum_root->node);
1106         if (fs_info->dev_root)
1107                 free_extent_buffer(fs_info->dev_root->node);
1108         if (fs_info->extent_root)
1109                 free_extent_buffer(fs_info->extent_root->node);
1110         if (fs_info->tree_root)
1111                 free_extent_buffer(fs_info->tree_root->node);
1112         if (fs_info->log_root_tree)
1113                 free_extent_buffer(fs_info->log_root_tree->node);
1114         if (fs_info->chunk_root)
1115                 free_extent_buffer(fs_info->chunk_root->node);
1116 }
1117
1118 static void free_map_lookup(struct cache_extent *ce)
1119 {
1120         struct map_lookup *map;
1121
1122         map = container_of(ce, struct map_lookup, ce);
1123         kfree(map);
1124 }
1125
1126 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
1127
1128 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
1129 {
1130         while (!list_empty(&fs_info->recow_ebs)) {
1131                 struct extent_buffer *eb;
1132                 eb = list_first_entry(&fs_info->recow_ebs,
1133                                       struct extent_buffer, recow);
1134                 list_del_init(&eb->recow);
1135                 free_extent_buffer(eb);
1136         }
1137         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
1138         extent_io_tree_cleanup(&fs_info->extent_cache);
1139         extent_io_tree_cleanup(&fs_info->free_space_cache);
1140         extent_io_tree_cleanup(&fs_info->block_group_cache);
1141         extent_io_tree_cleanup(&fs_info->pinned_extents);
1142         extent_io_tree_cleanup(&fs_info->pending_del);
1143         extent_io_tree_cleanup(&fs_info->extent_ins);
1144 }
1145
1146 int btrfs_scan_fs_devices(int fd, const char *path,
1147                           struct btrfs_fs_devices **fs_devices,
1148                           u64 sb_bytenr, unsigned sbflags,
1149                           int skip_devices)
1150 {
1151         u64 total_devs;
1152         u64 dev_size;
1153         off_t seek_ret;
1154         int ret;
1155         if (!sb_bytenr)
1156                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1157
1158         seek_ret = lseek(fd, 0, SEEK_END);
1159         if (seek_ret < 0)
1160                 return -errno;
1161
1162         dev_size = seek_ret;
1163         lseek(fd, 0, SEEK_SET);
1164         if (sb_bytenr > dev_size) {
1165                 error("superblock bytenr %llu is larger than device size %llu",
1166                                 (unsigned long long)sb_bytenr,
1167                                 (unsigned long long)dev_size);
1168                 return -EINVAL;
1169         }
1170
1171         ret = btrfs_scan_one_device(fd, path, fs_devices,
1172                                     &total_devs, sb_bytenr, sbflags);
1173         if (ret) {
1174                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1175                 return ret;
1176         }
1177
1178         if (!skip_devices && total_devs != 1) {
1179                 ret = btrfs_scan_devices();
1180                 if (ret)
1181                         return ret;
1182         }
1183         return 0;
1184 }
1185
1186 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
1187                                           u64 chunk_root_bytenr)
1188 {
1189         struct btrfs_super_block *sb = fs_info->super_copy;
1190         u32 sectorsize;
1191         u32 nodesize;
1192         u32 leafsize;
1193         u32 blocksize;
1194         u32 stripesize;
1195         u64 generation;
1196         int ret;
1197
1198         nodesize = btrfs_super_nodesize(sb);
1199         leafsize = btrfs_super_leafsize(sb);
1200         sectorsize = btrfs_super_sectorsize(sb);
1201         stripesize = btrfs_super_stripesize(sb);
1202
1203         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1204                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1205
1206         ret = btrfs_read_sys_array(fs_info->chunk_root);
1207         if (ret)
1208                 return ret;
1209
1210         blocksize = fs_info->chunk_root->nodesize;
1211         generation = btrfs_super_chunk_root_generation(sb);
1212
1213         if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
1214                                             btrfs_super_sectorsize(sb))) {
1215                 warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
1216                         chunk_root_bytenr, btrfs_super_sectorsize(sb));
1217                 chunk_root_bytenr = 0;
1218         }
1219
1220         if (!chunk_root_bytenr)
1221                 chunk_root_bytenr = btrfs_super_chunk_root(sb);
1222         else
1223                 generation = 0;
1224
1225         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1226                                                     chunk_root_bytenr,
1227                                                     blocksize, generation);
1228         if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
1229                 if (fs_info->ignore_chunk_tree_error) {
1230                         warning("cannot read chunk root, continue anyway");
1231                         fs_info->chunk_root = NULL;
1232                         return 0;
1233                 } else {
1234                         error("cannot read chunk root");
1235                         return -EIO;
1236                 }
1237         }
1238
1239         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1240                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1241                 if (ret) {
1242                         fprintf(stderr, "Couldn't read chunk tree\n");
1243                         return ret;
1244                 }
1245         }
1246         return 0;
1247 }
1248
1249 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1250                                              u64 sb_bytenr,
1251                                              u64 root_tree_bytenr,
1252                                              u64 chunk_root_bytenr,
1253                                              unsigned flags)
1254 {
1255         struct btrfs_fs_info *fs_info;
1256         struct btrfs_super_block *disk_super;
1257         struct btrfs_fs_devices *fs_devices = NULL;
1258         struct extent_buffer *eb;
1259         int ret;
1260         int oflags;
1261         unsigned sbflags = SBREAD_DEFAULT;
1262
1263         if (sb_bytenr == 0)
1264                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1265
1266         /* try to drop all the caches */
1267         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1268                 fprintf(stderr, "Warning, could not drop caches\n");
1269
1270         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1271         if (!fs_info) {
1272                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1273                 return NULL;
1274         }
1275         if (flags & OPEN_CTREE_RESTORE)
1276                 fs_info->on_restoring = 1;
1277         if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS)
1278                 fs_info->suppress_check_block_errors = 1;
1279         if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
1280                 fs_info->ignore_fsid_mismatch = 1;
1281         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR)
1282                 fs_info->ignore_chunk_tree_error = 1;
1283
1284         if ((flags & OPEN_CTREE_RECOVER_SUPER)
1285              && (flags & OPEN_CTREE_FS_PARTIAL)) {
1286                 fprintf(stderr,
1287                     "cannot open a partially created filesystem for recovery");
1288                 goto out;
1289         }
1290
1291         if (flags & OPEN_CTREE_FS_PARTIAL)
1292                 sbflags = SBREAD_PARTIAL;
1293
1294         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr, sbflags,
1295                         (flags & OPEN_CTREE_NO_DEVICES));
1296         if (ret)
1297                 goto out;
1298
1299         fs_info->fs_devices = fs_devices;
1300         if (flags & OPEN_CTREE_WRITES)
1301                 oflags = O_RDWR;
1302         else
1303                 oflags = O_RDONLY;
1304
1305         if (flags & OPEN_CTREE_EXCLUSIVE)
1306                 oflags |= O_EXCL;
1307
1308         ret = btrfs_open_devices(fs_devices, oflags);
1309         if (ret)
1310                 goto out;
1311
1312         disk_super = fs_info->super_copy;
1313         if (flags & OPEN_CTREE_RECOVER_SUPER)
1314                 ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super,
1315                                 sb_bytenr, SBREAD_RECOVER);
1316         else
1317                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr,
1318                                 sbflags);
1319         if (ret) {
1320                 printk("No valid btrfs found\n");
1321                 goto out_devices;
1322         }
1323
1324         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID &&
1325             !fs_info->ignore_fsid_mismatch) {
1326                 fprintf(stderr, "ERROR: Filesystem UUID change in progress\n");
1327                 goto out_devices;
1328         }
1329
1330         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1331
1332         ret = btrfs_check_fs_compatibility(fs_info->super_copy, flags);
1333         if (ret)
1334                 goto out_devices;
1335
1336         ret = btrfs_setup_chunk_tree_and_device_map(fs_info, chunk_root_bytenr);
1337         if (ret)
1338                 goto out_chunk;
1339
1340         /* Chunk tree root is unable to read, return directly */
1341         if (!fs_info->chunk_root)
1342                 return fs_info;
1343
1344         eb = fs_info->chunk_root->node;
1345         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1346                            btrfs_header_chunk_tree_uuid(eb),
1347                            BTRFS_UUID_SIZE);
1348
1349         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1350         if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) &&
1351             !fs_info->ignore_chunk_tree_error)
1352                 goto out_chunk;
1353
1354         return fs_info;
1355
1356 out_chunk:
1357         btrfs_release_all_roots(fs_info);
1358         btrfs_cleanup_all_caches(fs_info);
1359 out_devices:
1360         btrfs_close_devices(fs_devices);
1361 out:
1362         btrfs_free_fs_info(fs_info);
1363         return NULL;
1364 }
1365
1366 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1367                                          u64 sb_bytenr, u64 root_tree_bytenr,
1368                                          u64 chunk_root_bytenr,
1369                                          unsigned flags)
1370 {
1371         int fp;
1372         int ret;
1373         struct btrfs_fs_info *info;
1374         int oflags = O_RDWR;
1375         struct stat st;
1376
1377         ret = stat(filename, &st);
1378         if (ret < 0) {
1379                 error("cannot stat '%s': %s", filename, strerror(errno));
1380                 return NULL;
1381         }
1382         if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) {
1383                 error("not a regular file or block device: %s", filename);
1384                 return NULL;
1385         }
1386
1387         if (!(flags & OPEN_CTREE_WRITES))
1388                 oflags = O_RDONLY;
1389
1390         fp = open(filename, oflags);
1391         if (fp < 0) {
1392                 error("cannot open '%s': %s", filename, strerror(errno));
1393                 return NULL;
1394         }
1395         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1396                                chunk_root_bytenr, flags);
1397         close(fp);
1398         return info;
1399 }
1400
1401 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1402                               unsigned flags)
1403 {
1404         struct btrfs_fs_info *info;
1405
1406         /* This flags may not return fs_info with any valid root */
1407         BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
1408         info = open_ctree_fs_info(filename, sb_bytenr, 0, 0, flags);
1409         if (!info)
1410                 return NULL;
1411         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1412                 return info->chunk_root;
1413         return info->fs_root;
1414 }
1415
1416 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1417                                  unsigned flags)
1418 {
1419         struct btrfs_fs_info *info;
1420
1421         /* This flags may not return fs_info with any valid root */
1422         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) {
1423                 error("invalid open_ctree flags: 0x%llx",
1424                                 (unsigned long long)flags);
1425                 return NULL;
1426         }
1427         info = __open_ctree_fd(fp, path, sb_bytenr, 0, 0, flags);
1428         if (!info)
1429                 return NULL;
1430         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1431                 return info->chunk_root;
1432         return info->fs_root;
1433 }
1434
1435 /*
1436  * Check if the super is valid:
1437  * - nodesize/sectorsize - minimum, maximum, alignment
1438  * - tree block starts   - alignment
1439  * - number of devices   - something sane
1440  * - sys array size      - maximum
1441  */
1442 static int check_super(struct btrfs_super_block *sb, unsigned sbflags)
1443 {
1444         u8 result[BTRFS_CSUM_SIZE];
1445         u32 crc;
1446         u16 csum_type;
1447         int csum_size;
1448
1449         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
1450                 if (btrfs_super_magic(sb) == BTRFS_MAGIC_PARTIAL) {
1451                         if (!(sbflags & SBREAD_PARTIAL)) {
1452                                 error("superblock magic doesn't match");
1453                                 return -EIO;
1454                         }
1455                 }
1456         }
1457
1458         csum_type = btrfs_super_csum_type(sb);
1459         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
1460                 error("unsupported checksum algorithm %u", csum_type);
1461                 return -EIO;
1462         }
1463         csum_size = btrfs_csum_sizes[csum_type];
1464
1465         crc = ~(u32)0;
1466         crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1467                               BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1468         btrfs_csum_final(crc, result);
1469
1470         if (memcmp(result, sb->csum, csum_size)) {
1471                 error("superblock checksum mismatch");
1472                 return -EIO;
1473         }
1474         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
1475                 error("tree_root level too big: %d >= %d",
1476                         btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
1477                 goto error_out;
1478         }
1479         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
1480                 error("chunk_root level too big: %d >= %d",
1481                         btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
1482                 goto error_out;
1483         }
1484         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
1485                 error("log_root level too big: %d >= %d",
1486                         btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
1487                 goto error_out;
1488         }
1489
1490         if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
1491                 error("tree_root block unaligned: %llu", btrfs_super_root(sb));
1492                 goto error_out;
1493         }
1494         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
1495                 error("chunk_root block unaligned: %llu",
1496                         btrfs_super_chunk_root(sb));
1497                 goto error_out;
1498         }
1499         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
1500                 error("log_root block unaligned: %llu",
1501                         btrfs_super_log_root(sb));
1502                 goto error_out;
1503         }
1504         if (btrfs_super_nodesize(sb) < 4096) {
1505                 error("nodesize too small: %u < 4096",
1506                         btrfs_super_nodesize(sb));
1507                 goto error_out;
1508         }
1509         if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
1510                 error("nodesize unaligned: %u", btrfs_super_nodesize(sb));
1511                 goto error_out;
1512         }
1513         if (btrfs_super_sectorsize(sb) < 4096) {
1514                 error("sectorsize too small: %u < 4096",
1515                         btrfs_super_sectorsize(sb));
1516                 goto error_out;
1517         }
1518         if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
1519                 error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb));
1520                 goto error_out;
1521         }
1522         if (btrfs_super_total_bytes(sb) == 0) {
1523                 error("invalid total_bytes 0");
1524                 goto error_out;
1525         }
1526         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
1527                 error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
1528                 goto error_out;
1529         }
1530         if ((btrfs_super_stripesize(sb) != 4096)
1531                 && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
1532                 error("invalid stripesize %u", btrfs_super_stripesize(sb));
1533                 goto error_out;
1534         }
1535
1536         if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
1537                 char fsid[BTRFS_UUID_UNPARSED_SIZE];
1538                 char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
1539
1540                 uuid_unparse(sb->fsid, fsid);
1541                 uuid_unparse(sb->dev_item.fsid, dev_fsid);
1542                 error("dev_item UUID does not match fsid: %s != %s",
1543                         dev_fsid, fsid);
1544                 goto error_out;
1545         }
1546
1547         /*
1548          * Hint to catch really bogus numbers, bitflips or so
1549          */
1550         if (btrfs_super_num_devices(sb) > (1UL << 31)) {
1551                 warning("suspicious number of devices: %llu",
1552                         btrfs_super_num_devices(sb));
1553         }
1554
1555         if (btrfs_super_num_devices(sb) == 0) {
1556                 error("number of devices is 0");
1557                 goto error_out;
1558         }
1559
1560         /*
1561          * Obvious sys_chunk_array corruptions, it must hold at least one key
1562          * and one chunk
1563          */
1564         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
1565                 error("system chunk array too big %u > %u",
1566                       btrfs_super_sys_array_size(sb),
1567                       BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
1568                 goto error_out;
1569         }
1570         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
1571                         + sizeof(struct btrfs_chunk)) {
1572                 error("system chunk array too small %u < %zu",
1573                       btrfs_super_sys_array_size(sb),
1574                       sizeof(struct btrfs_disk_key) +
1575                       sizeof(struct btrfs_chunk));
1576                 goto error_out;
1577         }
1578
1579         return 0;
1580
1581 error_out:
1582         error("superblock checksum matches but it has invalid members");
1583         return -EIO;
1584 }
1585
1586 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1587                          unsigned sbflags)
1588 {
1589         u8 fsid[BTRFS_FSID_SIZE];
1590         int fsid_is_initialized = 0;
1591         char tmp[BTRFS_SUPER_INFO_SIZE];
1592         struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
1593         int i;
1594         int ret;
1595         int max_super = sbflags & SBREAD_RECOVER ? BTRFS_SUPER_MIRROR_MAX : 1;
1596         u64 transid = 0;
1597         u64 bytenr;
1598
1599         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1600                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
1601                 /* real error */
1602                 if (ret < 0)
1603                         return -errno;
1604
1605                 /* Not large enough sb, return -ENOENT instead of normal -EIO */
1606                 if (ret < BTRFS_SUPER_INFO_SIZE)
1607                         return -ENOENT;
1608
1609                 if (btrfs_super_bytenr(buf) != sb_bytenr)
1610                         return -EIO;
1611
1612                 ret = check_super(buf, sbflags);
1613                 if (ret < 0)
1614                         return ret;
1615                 memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1616                 return 0;
1617         }
1618
1619         /*
1620         * we would like to check all the supers, but that would make
1621         * a btrfs mount succeed after a mkfs from a different FS.
1622         * So, we need to add a special mount option to scan for
1623         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1624         */
1625
1626         for (i = 0; i < max_super; i++) {
1627                 bytenr = btrfs_sb_offset(i);
1628                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr);
1629                 if (ret < BTRFS_SUPER_INFO_SIZE)
1630                         break;
1631
1632                 if (btrfs_super_bytenr(buf) != bytenr )
1633                         continue;
1634                 /* if magic is NULL, the device was removed */
1635                 if (btrfs_super_magic(buf) == 0 && i == 0)
1636                         break;
1637                 if (check_super(buf, sbflags))
1638                         continue;
1639
1640                 if (!fsid_is_initialized) {
1641                         memcpy(fsid, buf->fsid, sizeof(fsid));
1642                         fsid_is_initialized = 1;
1643                 } else if (memcmp(fsid, buf->fsid, sizeof(fsid))) {
1644                         /*
1645                          * the superblocks (the original one and
1646                          * its backups) contain data of different
1647                          * filesystems -> the super cannot be trusted
1648                          */
1649                         continue;
1650                 }
1651
1652                 if (btrfs_super_generation(buf) > transid) {
1653                         memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1654                         transid = btrfs_super_generation(buf);
1655                 }
1656         }
1657
1658         return transid > 0 ? 0 : -1;
1659 }
1660
1661 static int write_dev_supers(struct btrfs_root *root,
1662                             struct btrfs_super_block *sb,
1663                             struct btrfs_device *device)
1664 {
1665         u64 bytenr;
1666         u32 crc;
1667         int i, ret;
1668
1669         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1670                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1671                 crc = ~(u32)0;
1672                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1673                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1674                 btrfs_csum_final(crc, &sb->csum[0]);
1675
1676                 /*
1677                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1678                  * zero filled, we can use it directly
1679                  */
1680                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1681                                 BTRFS_SUPER_INFO_SIZE,
1682                                 root->fs_info->super_bytenr);
1683                 if (ret != BTRFS_SUPER_INFO_SIZE)
1684                         goto write_err;
1685                 return 0;
1686         }
1687
1688         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1689                 bytenr = btrfs_sb_offset(i);
1690                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1691                         break;
1692
1693                 btrfs_set_super_bytenr(sb, bytenr);
1694
1695                 crc = ~(u32)0;
1696                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1697                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1698                 btrfs_csum_final(crc, &sb->csum[0]);
1699
1700                 /*
1701                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1702                  * zero filled, we can use it directly
1703                  */
1704                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1705                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1706                 if (ret != BTRFS_SUPER_INFO_SIZE)
1707                         goto write_err;
1708         }
1709
1710         return 0;
1711
1712 write_err:
1713         if (ret > 0)
1714                 fprintf(stderr, "WARNING: failed to write all sb data\n");
1715         else
1716                 fprintf(stderr, "WARNING: failed to write sb: %s\n",
1717                         strerror(errno));
1718         return ret;
1719 }
1720
1721 int write_all_supers(struct btrfs_root *root)
1722 {
1723         struct list_head *cur;
1724         struct list_head *head = &root->fs_info->fs_devices->devices;
1725         struct btrfs_device *dev;
1726         struct btrfs_super_block *sb;
1727         struct btrfs_dev_item *dev_item;
1728         int ret;
1729         u64 flags;
1730
1731         sb = root->fs_info->super_copy;
1732         dev_item = &sb->dev_item;
1733         list_for_each(cur, head) {
1734                 dev = list_entry(cur, struct btrfs_device, dev_list);
1735                 if (!dev->writeable)
1736                         continue;
1737
1738                 btrfs_set_stack_device_generation(dev_item, 0);
1739                 btrfs_set_stack_device_type(dev_item, dev->type);
1740                 btrfs_set_stack_device_id(dev_item, dev->devid);
1741                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1742                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1743                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1744                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1745                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1746                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1747                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1748
1749                 flags = btrfs_super_flags(sb);
1750                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1751
1752                 ret = write_dev_supers(root, sb, dev);
1753                 BUG_ON(ret);
1754         }
1755         return 0;
1756 }
1757
1758 int write_ctree_super(struct btrfs_trans_handle *trans,
1759                       struct btrfs_root *root)
1760 {
1761         int ret;
1762         struct btrfs_root *tree_root = root->fs_info->tree_root;
1763         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1764
1765         if (root->fs_info->readonly)
1766                 return 0;
1767
1768         btrfs_set_super_generation(root->fs_info->super_copy,
1769                                    trans->transid);
1770         btrfs_set_super_root(root->fs_info->super_copy,
1771                              tree_root->node->start);
1772         btrfs_set_super_root_level(root->fs_info->super_copy,
1773                                    btrfs_header_level(tree_root->node));
1774         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1775                                    chunk_root->node->start);
1776         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1777                                          btrfs_header_level(chunk_root->node));
1778         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1779                                 btrfs_header_generation(chunk_root->node));
1780
1781         ret = write_all_supers(root);
1782         if (ret)
1783                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1784         return ret;
1785 }
1786
1787 int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
1788 {
1789         int ret;
1790         struct btrfs_trans_handle *trans;
1791         struct btrfs_root *root = fs_info->tree_root;
1792
1793         if (fs_info->last_trans_committed !=
1794             fs_info->generation) {
1795                 BUG_ON(!root);
1796                 trans = btrfs_start_transaction(root, 1);
1797                 btrfs_commit_transaction(trans, root);
1798                 trans = btrfs_start_transaction(root, 1);
1799                 ret = commit_tree_roots(trans, fs_info);
1800                 BUG_ON(ret);
1801                 ret = __commit_transaction(trans, root);
1802                 BUG_ON(ret);
1803                 write_ctree_super(trans, root);
1804                 btrfs_free_transaction(root, trans);
1805         }
1806
1807         if (fs_info->finalize_on_close) {
1808                 btrfs_set_super_magic(fs_info->super_copy, BTRFS_MAGIC);
1809                 root->fs_info->finalize_on_close = 0;
1810                 ret = write_all_supers(root);
1811                 if (ret)
1812                         fprintf(stderr,
1813                                 "failed to write new super block err %d\n", ret);
1814         }
1815         btrfs_free_block_groups(fs_info);
1816
1817         free_fs_roots_tree(&fs_info->fs_root_tree);
1818
1819         btrfs_release_all_roots(fs_info);
1820         btrfs_close_devices(fs_info->fs_devices);
1821         btrfs_cleanup_all_caches(fs_info);
1822         btrfs_free_fs_info(fs_info);
1823         return 0;
1824 }
1825
1826 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1827                      struct extent_buffer *eb)
1828 {
1829         return clear_extent_buffer_dirty(eb);
1830 }
1831
1832 int wait_on_tree_block_writeback(struct btrfs_root *root,
1833                                  struct extent_buffer *eb)
1834 {
1835         return 0;
1836 }
1837
1838 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1839 {
1840         set_extent_buffer_dirty(eb);
1841 }
1842
1843 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1844 {
1845         int ret;
1846
1847         ret = extent_buffer_uptodate(buf);
1848         if (!ret)
1849                 return ret;
1850
1851         ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1852         return !ret;
1853 }
1854
1855 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1856 {
1857         return set_extent_buffer_uptodate(eb);
1858 }