btrfs: replace get_seconds with new 64bit time API
[sfrench/cifs-2.6.git] / fs / btrfs / disk-io.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5
6 #include <linux/fs.h>
7 #include <linux/blkdev.h>
8 #include <linux/scatterlist.h>
9 #include <linux/swap.h>
10 #include <linux/radix-tree.h>
11 #include <linux/writeback.h>
12 #include <linux/buffer_head.h>
13 #include <linux/workqueue.h>
14 #include <linux/kthread.h>
15 #include <linux/slab.h>
16 #include <linux/migrate.h>
17 #include <linux/ratelimit.h>
18 #include <linux/uuid.h>
19 #include <linux/semaphore.h>
20 #include <linux/error-injection.h>
21 #include <linux/crc32c.h>
22 #include <asm/unaligned.h>
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "transaction.h"
26 #include "btrfs_inode.h"
27 #include "volumes.h"
28 #include "print-tree.h"
29 #include "locking.h"
30 #include "tree-log.h"
31 #include "free-space-cache.h"
32 #include "free-space-tree.h"
33 #include "inode-map.h"
34 #include "check-integrity.h"
35 #include "rcu-string.h"
36 #include "dev-replace.h"
37 #include "raid56.h"
38 #include "sysfs.h"
39 #include "qgroup.h"
40 #include "compression.h"
41 #include "tree-checker.h"
42 #include "ref-verify.h"
43
44 #ifdef CONFIG_X86
45 #include <asm/cpufeature.h>
46 #endif
47
48 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
49                                  BTRFS_HEADER_FLAG_RELOC |\
50                                  BTRFS_SUPER_FLAG_ERROR |\
51                                  BTRFS_SUPER_FLAG_SEEDING |\
52                                  BTRFS_SUPER_FLAG_METADUMP |\
53                                  BTRFS_SUPER_FLAG_METADUMP_V2)
54
55 static const struct extent_io_ops btree_extent_io_ops;
56 static void end_workqueue_fn(struct btrfs_work *work);
57 static void free_fs_root(struct btrfs_root *root);
58 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
59 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
60                                       struct btrfs_fs_info *fs_info);
61 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
62 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
63                                         struct extent_io_tree *dirty_pages,
64                                         int mark);
65 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
66                                        struct extent_io_tree *pinned_extents);
67 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
68 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
69
70 /*
71  * btrfs_end_io_wq structs are used to do processing in task context when an IO
72  * is complete.  This is used during reads to verify checksums, and it is used
73  * by writes to insert metadata for new file extents after IO is complete.
74  */
75 struct btrfs_end_io_wq {
76         struct bio *bio;
77         bio_end_io_t *end_io;
78         void *private;
79         struct btrfs_fs_info *info;
80         blk_status_t status;
81         enum btrfs_wq_endio_type metadata;
82         struct btrfs_work work;
83 };
84
85 static struct kmem_cache *btrfs_end_io_wq_cache;
86
87 int __init btrfs_end_io_wq_init(void)
88 {
89         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
90                                         sizeof(struct btrfs_end_io_wq),
91                                         0,
92                                         SLAB_MEM_SPREAD,
93                                         NULL);
94         if (!btrfs_end_io_wq_cache)
95                 return -ENOMEM;
96         return 0;
97 }
98
99 void __cold btrfs_end_io_wq_exit(void)
100 {
101         kmem_cache_destroy(btrfs_end_io_wq_cache);
102 }
103
104 /*
105  * async submit bios are used to offload expensive checksumming
106  * onto the worker threads.  They checksum file and metadata bios
107  * just before they are sent down the IO stack.
108  */
109 struct async_submit_bio {
110         void *private_data;
111         struct btrfs_fs_info *fs_info;
112         struct bio *bio;
113         extent_submit_bio_start_t *submit_bio_start;
114         extent_submit_bio_done_t *submit_bio_done;
115         int mirror_num;
116         unsigned long bio_flags;
117         /*
118          * bio_offset is optional, can be used if the pages in the bio
119          * can't tell us where in the file the bio should go
120          */
121         u64 bio_offset;
122         struct btrfs_work work;
123         blk_status_t status;
124 };
125
126 /*
127  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
128  * eb, the lockdep key is determined by the btrfs_root it belongs to and
129  * the level the eb occupies in the tree.
130  *
131  * Different roots are used for different purposes and may nest inside each
132  * other and they require separate keysets.  As lockdep keys should be
133  * static, assign keysets according to the purpose of the root as indicated
134  * by btrfs_root->objectid.  This ensures that all special purpose roots
135  * have separate keysets.
136  *
137  * Lock-nesting across peer nodes is always done with the immediate parent
138  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
139  * subclass to avoid triggering lockdep warning in such cases.
140  *
141  * The key is set by the readpage_end_io_hook after the buffer has passed
142  * csum validation but before the pages are unlocked.  It is also set by
143  * btrfs_init_new_buffer on freshly allocated blocks.
144  *
145  * We also add a check to make sure the highest level of the tree is the
146  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
147  * needs update as well.
148  */
149 #ifdef CONFIG_DEBUG_LOCK_ALLOC
150 # if BTRFS_MAX_LEVEL != 8
151 #  error
152 # endif
153
154 static struct btrfs_lockdep_keyset {
155         u64                     id;             /* root objectid */
156         const char              *name_stem;     /* lock name stem */
157         char                    names[BTRFS_MAX_LEVEL + 1][20];
158         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
159 } btrfs_lockdep_keysets[] = {
160         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
161         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
162         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
163         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
164         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
165         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
166         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
167         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
168         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
169         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
170         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
171         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
172         { .id = 0,                              .name_stem = "tree"     },
173 };
174
175 void __init btrfs_init_lockdep(void)
176 {
177         int i, j;
178
179         /* initialize lockdep class names */
180         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
181                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
182
183                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
184                         snprintf(ks->names[j], sizeof(ks->names[j]),
185                                  "btrfs-%s-%02d", ks->name_stem, j);
186         }
187 }
188
189 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
190                                     int level)
191 {
192         struct btrfs_lockdep_keyset *ks;
193
194         BUG_ON(level >= ARRAY_SIZE(ks->keys));
195
196         /* find the matching keyset, id 0 is the default entry */
197         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
198                 if (ks->id == objectid)
199                         break;
200
201         lockdep_set_class_and_name(&eb->lock,
202                                    &ks->keys[level], ks->names[level]);
203 }
204
205 #endif
206
207 /*
208  * extents on the btree inode are pretty simple, there's one extent
209  * that covers the entire device
210  */
211 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
212                 struct page *page, size_t pg_offset, u64 start, u64 len,
213                 int create)
214 {
215         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
216         struct extent_map_tree *em_tree = &inode->extent_tree;
217         struct extent_map *em;
218         int ret;
219
220         read_lock(&em_tree->lock);
221         em = lookup_extent_mapping(em_tree, start, len);
222         if (em) {
223                 em->bdev = fs_info->fs_devices->latest_bdev;
224                 read_unlock(&em_tree->lock);
225                 goto out;
226         }
227         read_unlock(&em_tree->lock);
228
229         em = alloc_extent_map();
230         if (!em) {
231                 em = ERR_PTR(-ENOMEM);
232                 goto out;
233         }
234         em->start = 0;
235         em->len = (u64)-1;
236         em->block_len = (u64)-1;
237         em->block_start = 0;
238         em->bdev = fs_info->fs_devices->latest_bdev;
239
240         write_lock(&em_tree->lock);
241         ret = add_extent_mapping(em_tree, em, 0);
242         if (ret == -EEXIST) {
243                 free_extent_map(em);
244                 em = lookup_extent_mapping(em_tree, start, len);
245                 if (!em)
246                         em = ERR_PTR(-EIO);
247         } else if (ret) {
248                 free_extent_map(em);
249                 em = ERR_PTR(ret);
250         }
251         write_unlock(&em_tree->lock);
252
253 out:
254         return em;
255 }
256
257 u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
258 {
259         return crc32c(seed, data, len);
260 }
261
262 void btrfs_csum_final(u32 crc, u8 *result)
263 {
264         put_unaligned_le32(~crc, result);
265 }
266
267 /*
268  * compute the csum for a btree block, and either verify it or write it
269  * into the csum field of the block.
270  */
271 static int csum_tree_block(struct btrfs_fs_info *fs_info,
272                            struct extent_buffer *buf,
273                            int verify)
274 {
275         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
276         char result[BTRFS_CSUM_SIZE];
277         unsigned long len;
278         unsigned long cur_len;
279         unsigned long offset = BTRFS_CSUM_SIZE;
280         char *kaddr;
281         unsigned long map_start;
282         unsigned long map_len;
283         int err;
284         u32 crc = ~(u32)0;
285
286         len = buf->len - offset;
287         while (len > 0) {
288                 err = map_private_extent_buffer(buf, offset, 32,
289                                         &kaddr, &map_start, &map_len);
290                 if (err)
291                         return err;
292                 cur_len = min(len, map_len - (offset - map_start));
293                 crc = btrfs_csum_data(kaddr + offset - map_start,
294                                       crc, cur_len);
295                 len -= cur_len;
296                 offset += cur_len;
297         }
298         memset(result, 0, BTRFS_CSUM_SIZE);
299
300         btrfs_csum_final(crc, result);
301
302         if (verify) {
303                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
304                         u32 val;
305                         u32 found = 0;
306                         memcpy(&found, result, csum_size);
307
308                         read_extent_buffer(buf, &val, 0, csum_size);
309                         btrfs_warn_rl(fs_info,
310                                 "%s checksum verify failed on %llu wanted %X found %X level %d",
311                                 fs_info->sb->s_id, buf->start,
312                                 val, found, btrfs_header_level(buf));
313                         return -EUCLEAN;
314                 }
315         } else {
316                 write_extent_buffer(buf, result, 0, csum_size);
317         }
318
319         return 0;
320 }
321
322 /*
323  * we can't consider a given block up to date unless the transid of the
324  * block matches the transid in the parent node's pointer.  This is how we
325  * detect blocks that either didn't get written at all or got written
326  * in the wrong place.
327  */
328 static int verify_parent_transid(struct extent_io_tree *io_tree,
329                                  struct extent_buffer *eb, u64 parent_transid,
330                                  int atomic)
331 {
332         struct extent_state *cached_state = NULL;
333         int ret;
334         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
335
336         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
337                 return 0;
338
339         if (atomic)
340                 return -EAGAIN;
341
342         if (need_lock) {
343                 btrfs_tree_read_lock(eb);
344                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
345         }
346
347         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
348                          &cached_state);
349         if (extent_buffer_uptodate(eb) &&
350             btrfs_header_generation(eb) == parent_transid) {
351                 ret = 0;
352                 goto out;
353         }
354         btrfs_err_rl(eb->fs_info,
355                 "parent transid verify failed on %llu wanted %llu found %llu",
356                         eb->start,
357                         parent_transid, btrfs_header_generation(eb));
358         ret = 1;
359
360         /*
361          * Things reading via commit roots that don't have normal protection,
362          * like send, can have a really old block in cache that may point at a
363          * block that has been freed and re-allocated.  So don't clear uptodate
364          * if we find an eb that is under IO (dirty/writeback) because we could
365          * end up reading in the stale data and then writing it back out and
366          * making everybody very sad.
367          */
368         if (!extent_buffer_under_io(eb))
369                 clear_extent_buffer_uptodate(eb);
370 out:
371         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
372                              &cached_state);
373         if (need_lock)
374                 btrfs_tree_read_unlock_blocking(eb);
375         return ret;
376 }
377
378 /*
379  * Return 0 if the superblock checksum type matches the checksum value of that
380  * algorithm. Pass the raw disk superblock data.
381  */
382 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
383                                   char *raw_disk_sb)
384 {
385         struct btrfs_super_block *disk_sb =
386                 (struct btrfs_super_block *)raw_disk_sb;
387         u16 csum_type = btrfs_super_csum_type(disk_sb);
388         int ret = 0;
389
390         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
391                 u32 crc = ~(u32)0;
392                 char result[sizeof(crc)];
393
394                 /*
395                  * The super_block structure does not span the whole
396                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
397                  * is filled with zeros and is included in the checksum.
398                  */
399                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
400                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
401                 btrfs_csum_final(crc, result);
402
403                 if (memcmp(raw_disk_sb, result, sizeof(result)))
404                         ret = 1;
405         }
406
407         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
408                 btrfs_err(fs_info, "unsupported checksum algorithm %u",
409                                 csum_type);
410                 ret = 1;
411         }
412
413         return ret;
414 }
415
416 static int verify_level_key(struct btrfs_fs_info *fs_info,
417                             struct extent_buffer *eb, int level,
418                             struct btrfs_key *first_key, u64 parent_transid)
419 {
420         int found_level;
421         struct btrfs_key found_key;
422         int ret;
423
424         found_level = btrfs_header_level(eb);
425         if (found_level != level) {
426 #ifdef CONFIG_BTRFS_DEBUG
427                 WARN_ON(1);
428                 btrfs_err(fs_info,
429 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
430                           eb->start, level, found_level);
431 #endif
432                 return -EIO;
433         }
434
435         if (!first_key)
436                 return 0;
437
438         /*
439          * For live tree block (new tree blocks in current transaction),
440          * we need proper lock context to avoid race, which is impossible here.
441          * So we only checks tree blocks which is read from disk, whose
442          * generation <= fs_info->last_trans_committed.
443          */
444         if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
445                 return 0;
446         if (found_level)
447                 btrfs_node_key_to_cpu(eb, &found_key, 0);
448         else
449                 btrfs_item_key_to_cpu(eb, &found_key, 0);
450         ret = btrfs_comp_cpu_keys(first_key, &found_key);
451
452 #ifdef CONFIG_BTRFS_DEBUG
453         if (ret) {
454                 WARN_ON(1);
455                 btrfs_err(fs_info,
456 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
457                           eb->start, parent_transid, first_key->objectid,
458                           first_key->type, first_key->offset,
459                           found_key.objectid, found_key.type,
460                           found_key.offset);
461         }
462 #endif
463         return ret;
464 }
465
466 /*
467  * helper to read a given tree block, doing retries as required when
468  * the checksums don't match and we have alternate mirrors to try.
469  *
470  * @parent_transid:     expected transid, skip check if 0
471  * @level:              expected level, mandatory check
472  * @first_key:          expected key of first slot, skip check if NULL
473  */
474 static int btree_read_extent_buffer_pages(struct btrfs_fs_info *fs_info,
475                                           struct extent_buffer *eb,
476                                           u64 parent_transid, int level,
477                                           struct btrfs_key *first_key)
478 {
479         struct extent_io_tree *io_tree;
480         int failed = 0;
481         int ret;
482         int num_copies = 0;
483         int mirror_num = 0;
484         int failed_mirror = 0;
485
486         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
487         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
488         while (1) {
489                 ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
490                                                mirror_num);
491                 if (!ret) {
492                         if (verify_parent_transid(io_tree, eb,
493                                                    parent_transid, 0))
494                                 ret = -EIO;
495                         else if (verify_level_key(fs_info, eb, level,
496                                                   first_key, parent_transid))
497                                 ret = -EUCLEAN;
498                         else
499                                 break;
500                 }
501
502                 /*
503                  * This buffer's crc is fine, but its contents are corrupted, so
504                  * there is no reason to read the other copies, they won't be
505                  * any less wrong.
506                  */
507                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags) ||
508                     ret == -EUCLEAN)
509                         break;
510
511                 num_copies = btrfs_num_copies(fs_info,
512                                               eb->start, eb->len);
513                 if (num_copies == 1)
514                         break;
515
516                 if (!failed_mirror) {
517                         failed = 1;
518                         failed_mirror = eb->read_mirror;
519                 }
520
521                 mirror_num++;
522                 if (mirror_num == failed_mirror)
523                         mirror_num++;
524
525                 if (mirror_num > num_copies)
526                         break;
527         }
528
529         if (failed && !ret && failed_mirror)
530                 repair_eb_io_failure(fs_info, eb, failed_mirror);
531
532         return ret;
533 }
534
535 /*
536  * checksum a dirty tree block before IO.  This has extra checks to make sure
537  * we only fill in the checksum field in the first page of a multi-page block
538  */
539
540 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
541 {
542         u64 start = page_offset(page);
543         u64 found_start;
544         struct extent_buffer *eb;
545
546         eb = (struct extent_buffer *)page->private;
547         if (page != eb->pages[0])
548                 return 0;
549
550         found_start = btrfs_header_bytenr(eb);
551         /*
552          * Please do not consolidate these warnings into a single if.
553          * It is useful to know what went wrong.
554          */
555         if (WARN_ON(found_start != start))
556                 return -EUCLEAN;
557         if (WARN_ON(!PageUptodate(page)))
558                 return -EUCLEAN;
559
560         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
561                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
562
563         return csum_tree_block(fs_info, eb, 0);
564 }
565
566 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
567                                  struct extent_buffer *eb)
568 {
569         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
570         u8 fsid[BTRFS_FSID_SIZE];
571         int ret = 1;
572
573         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
574         while (fs_devices) {
575                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
576                         ret = 0;
577                         break;
578                 }
579                 fs_devices = fs_devices->seed;
580         }
581         return ret;
582 }
583
584 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
585                                       u64 phy_offset, struct page *page,
586                                       u64 start, u64 end, int mirror)
587 {
588         u64 found_start;
589         int found_level;
590         struct extent_buffer *eb;
591         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
592         struct btrfs_fs_info *fs_info = root->fs_info;
593         int ret = 0;
594         int reads_done;
595
596         if (!page->private)
597                 goto out;
598
599         eb = (struct extent_buffer *)page->private;
600
601         /* the pending IO might have been the only thing that kept this buffer
602          * in memory.  Make sure we have a ref for all this other checks
603          */
604         extent_buffer_get(eb);
605
606         reads_done = atomic_dec_and_test(&eb->io_pages);
607         if (!reads_done)
608                 goto err;
609
610         eb->read_mirror = mirror;
611         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
612                 ret = -EIO;
613                 goto err;
614         }
615
616         found_start = btrfs_header_bytenr(eb);
617         if (found_start != eb->start) {
618                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
619                              found_start, eb->start);
620                 ret = -EIO;
621                 goto err;
622         }
623         if (check_tree_block_fsid(fs_info, eb)) {
624                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
625                              eb->start);
626                 ret = -EIO;
627                 goto err;
628         }
629         found_level = btrfs_header_level(eb);
630         if (found_level >= BTRFS_MAX_LEVEL) {
631                 btrfs_err(fs_info, "bad tree block level %d",
632                           (int)btrfs_header_level(eb));
633                 ret = -EIO;
634                 goto err;
635         }
636
637         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
638                                        eb, found_level);
639
640         ret = csum_tree_block(fs_info, eb, 1);
641         if (ret)
642                 goto err;
643
644         /*
645          * If this is a leaf block and it is corrupt, set the corrupt bit so
646          * that we don't try and read the other copies of this block, just
647          * return -EIO.
648          */
649         if (found_level == 0 && btrfs_check_leaf_full(fs_info, eb)) {
650                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
651                 ret = -EIO;
652         }
653
654         if (found_level > 0 && btrfs_check_node(fs_info, eb))
655                 ret = -EIO;
656
657         if (!ret)
658                 set_extent_buffer_uptodate(eb);
659 err:
660         if (reads_done &&
661             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
662                 btree_readahead_hook(eb, ret);
663
664         if (ret) {
665                 /*
666                  * our io error hook is going to dec the io pages
667                  * again, we have to make sure it has something
668                  * to decrement
669                  */
670                 atomic_inc(&eb->io_pages);
671                 clear_extent_buffer_uptodate(eb);
672         }
673         free_extent_buffer(eb);
674 out:
675         return ret;
676 }
677
678 static int btree_io_failed_hook(struct page *page, int failed_mirror)
679 {
680         struct extent_buffer *eb;
681
682         eb = (struct extent_buffer *)page->private;
683         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
684         eb->read_mirror = failed_mirror;
685         atomic_dec(&eb->io_pages);
686         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
687                 btree_readahead_hook(eb, -EIO);
688         return -EIO;    /* we fixed nothing */
689 }
690
691 static void end_workqueue_bio(struct bio *bio)
692 {
693         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
694         struct btrfs_fs_info *fs_info;
695         struct btrfs_workqueue *wq;
696         btrfs_work_func_t func;
697
698         fs_info = end_io_wq->info;
699         end_io_wq->status = bio->bi_status;
700
701         if (bio_op(bio) == REQ_OP_WRITE) {
702                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
703                         wq = fs_info->endio_meta_write_workers;
704                         func = btrfs_endio_meta_write_helper;
705                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
706                         wq = fs_info->endio_freespace_worker;
707                         func = btrfs_freespace_write_helper;
708                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
709                         wq = fs_info->endio_raid56_workers;
710                         func = btrfs_endio_raid56_helper;
711                 } else {
712                         wq = fs_info->endio_write_workers;
713                         func = btrfs_endio_write_helper;
714                 }
715         } else {
716                 if (unlikely(end_io_wq->metadata ==
717                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
718                         wq = fs_info->endio_repair_workers;
719                         func = btrfs_endio_repair_helper;
720                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
721                         wq = fs_info->endio_raid56_workers;
722                         func = btrfs_endio_raid56_helper;
723                 } else if (end_io_wq->metadata) {
724                         wq = fs_info->endio_meta_workers;
725                         func = btrfs_endio_meta_helper;
726                 } else {
727                         wq = fs_info->endio_workers;
728                         func = btrfs_endio_helper;
729                 }
730         }
731
732         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
733         btrfs_queue_work(wq, &end_io_wq->work);
734 }
735
736 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
737                         enum btrfs_wq_endio_type metadata)
738 {
739         struct btrfs_end_io_wq *end_io_wq;
740
741         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
742         if (!end_io_wq)
743                 return BLK_STS_RESOURCE;
744
745         end_io_wq->private = bio->bi_private;
746         end_io_wq->end_io = bio->bi_end_io;
747         end_io_wq->info = info;
748         end_io_wq->status = 0;
749         end_io_wq->bio = bio;
750         end_io_wq->metadata = metadata;
751
752         bio->bi_private = end_io_wq;
753         bio->bi_end_io = end_workqueue_bio;
754         return 0;
755 }
756
757 static void run_one_async_start(struct btrfs_work *work)
758 {
759         struct async_submit_bio *async;
760         blk_status_t ret;
761
762         async = container_of(work, struct  async_submit_bio, work);
763         ret = async->submit_bio_start(async->private_data, async->bio,
764                                       async->bio_offset);
765         if (ret)
766                 async->status = ret;
767 }
768
769 static void run_one_async_done(struct btrfs_work *work)
770 {
771         struct async_submit_bio *async;
772
773         async = container_of(work, struct  async_submit_bio, work);
774
775         /* If an error occurred we just want to clean up the bio and move on */
776         if (async->status) {
777                 async->bio->bi_status = async->status;
778                 bio_endio(async->bio);
779                 return;
780         }
781
782         async->submit_bio_done(async->private_data, async->bio, async->mirror_num);
783 }
784
785 static void run_one_async_free(struct btrfs_work *work)
786 {
787         struct async_submit_bio *async;
788
789         async = container_of(work, struct  async_submit_bio, work);
790         kfree(async);
791 }
792
793 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
794                                  int mirror_num, unsigned long bio_flags,
795                                  u64 bio_offset, void *private_data,
796                                  extent_submit_bio_start_t *submit_bio_start,
797                                  extent_submit_bio_done_t *submit_bio_done)
798 {
799         struct async_submit_bio *async;
800
801         async = kmalloc(sizeof(*async), GFP_NOFS);
802         if (!async)
803                 return BLK_STS_RESOURCE;
804
805         async->private_data = private_data;
806         async->fs_info = fs_info;
807         async->bio = bio;
808         async->mirror_num = mirror_num;
809         async->submit_bio_start = submit_bio_start;
810         async->submit_bio_done = submit_bio_done;
811
812         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
813                         run_one_async_done, run_one_async_free);
814
815         async->bio_flags = bio_flags;
816         async->bio_offset = bio_offset;
817
818         async->status = 0;
819
820         if (op_is_sync(bio->bi_opf))
821                 btrfs_set_work_high_priority(&async->work);
822
823         btrfs_queue_work(fs_info->workers, &async->work);
824         return 0;
825 }
826
827 static blk_status_t btree_csum_one_bio(struct bio *bio)
828 {
829         struct bio_vec *bvec;
830         struct btrfs_root *root;
831         int i, ret = 0;
832
833         ASSERT(!bio_flagged(bio, BIO_CLONED));
834         bio_for_each_segment_all(bvec, bio, i) {
835                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
836                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
837                 if (ret)
838                         break;
839         }
840
841         return errno_to_blk_status(ret);
842 }
843
844 static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio,
845                                              u64 bio_offset)
846 {
847         /*
848          * when we're called for a write, we're already in the async
849          * submission context.  Just jump into btrfs_map_bio
850          */
851         return btree_csum_one_bio(bio);
852 }
853
854 static blk_status_t btree_submit_bio_done(void *private_data, struct bio *bio,
855                                             int mirror_num)
856 {
857         struct inode *inode = private_data;
858         blk_status_t ret;
859
860         /*
861          * when we're called for a write, we're already in the async
862          * submission context.  Just jump into btrfs_map_bio
863          */
864         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), bio, mirror_num, 1);
865         if (ret) {
866                 bio->bi_status = ret;
867                 bio_endio(bio);
868         }
869         return ret;
870 }
871
872 static int check_async_write(struct btrfs_inode *bi)
873 {
874         if (atomic_read(&bi->sync_writers))
875                 return 0;
876 #ifdef CONFIG_X86
877         if (static_cpu_has(X86_FEATURE_XMM4_2))
878                 return 0;
879 #endif
880         return 1;
881 }
882
883 static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
884                                           int mirror_num, unsigned long bio_flags,
885                                           u64 bio_offset)
886 {
887         struct inode *inode = private_data;
888         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
889         int async = check_async_write(BTRFS_I(inode));
890         blk_status_t ret;
891
892         if (bio_op(bio) != REQ_OP_WRITE) {
893                 /*
894                  * called for a read, do the setup so that checksum validation
895                  * can happen in the async kernel threads
896                  */
897                 ret = btrfs_bio_wq_end_io(fs_info, bio,
898                                           BTRFS_WQ_ENDIO_METADATA);
899                 if (ret)
900                         goto out_w_error;
901                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
902         } else if (!async) {
903                 ret = btree_csum_one_bio(bio);
904                 if (ret)
905                         goto out_w_error;
906                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
907         } else {
908                 /*
909                  * kthread helpers are used to submit writes so that
910                  * checksumming can happen in parallel across all CPUs
911                  */
912                 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
913                                           bio_offset, private_data,
914                                           btree_submit_bio_start,
915                                           btree_submit_bio_done);
916         }
917
918         if (ret)
919                 goto out_w_error;
920         return 0;
921
922 out_w_error:
923         bio->bi_status = ret;
924         bio_endio(bio);
925         return ret;
926 }
927
928 #ifdef CONFIG_MIGRATION
929 static int btree_migratepage(struct address_space *mapping,
930                         struct page *newpage, struct page *page,
931                         enum migrate_mode mode)
932 {
933         /*
934          * we can't safely write a btree page from here,
935          * we haven't done the locking hook
936          */
937         if (PageDirty(page))
938                 return -EAGAIN;
939         /*
940          * Buffers may be managed in a filesystem specific way.
941          * We must have no buffers or drop them.
942          */
943         if (page_has_private(page) &&
944             !try_to_release_page(page, GFP_KERNEL))
945                 return -EAGAIN;
946         return migrate_page(mapping, newpage, page, mode);
947 }
948 #endif
949
950
951 static int btree_writepages(struct address_space *mapping,
952                             struct writeback_control *wbc)
953 {
954         struct btrfs_fs_info *fs_info;
955         int ret;
956
957         if (wbc->sync_mode == WB_SYNC_NONE) {
958
959                 if (wbc->for_kupdate)
960                         return 0;
961
962                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
963                 /* this is a bit racy, but that's ok */
964                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
965                                              BTRFS_DIRTY_METADATA_THRESH);
966                 if (ret < 0)
967                         return 0;
968         }
969         return btree_write_cache_pages(mapping, wbc);
970 }
971
972 static int btree_readpage(struct file *file, struct page *page)
973 {
974         struct extent_io_tree *tree;
975         tree = &BTRFS_I(page->mapping->host)->io_tree;
976         return extent_read_full_page(tree, page, btree_get_extent, 0);
977 }
978
979 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
980 {
981         if (PageWriteback(page) || PageDirty(page))
982                 return 0;
983
984         return try_release_extent_buffer(page);
985 }
986
987 static void btree_invalidatepage(struct page *page, unsigned int offset,
988                                  unsigned int length)
989 {
990         struct extent_io_tree *tree;
991         tree = &BTRFS_I(page->mapping->host)->io_tree;
992         extent_invalidatepage(tree, page, offset);
993         btree_releasepage(page, GFP_NOFS);
994         if (PagePrivate(page)) {
995                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
996                            "page private not zero on page %llu",
997                            (unsigned long long)page_offset(page));
998                 ClearPagePrivate(page);
999                 set_page_private(page, 0);
1000                 put_page(page);
1001         }
1002 }
1003
1004 static int btree_set_page_dirty(struct page *page)
1005 {
1006 #ifdef DEBUG
1007         struct extent_buffer *eb;
1008
1009         BUG_ON(!PagePrivate(page));
1010         eb = (struct extent_buffer *)page->private;
1011         BUG_ON(!eb);
1012         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1013         BUG_ON(!atomic_read(&eb->refs));
1014         btrfs_assert_tree_locked(eb);
1015 #endif
1016         return __set_page_dirty_nobuffers(page);
1017 }
1018
1019 static const struct address_space_operations btree_aops = {
1020         .readpage       = btree_readpage,
1021         .writepages     = btree_writepages,
1022         .releasepage    = btree_releasepage,
1023         .invalidatepage = btree_invalidatepage,
1024 #ifdef CONFIG_MIGRATION
1025         .migratepage    = btree_migratepage,
1026 #endif
1027         .set_page_dirty = btree_set_page_dirty,
1028 };
1029
1030 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr)
1031 {
1032         struct extent_buffer *buf = NULL;
1033         struct inode *btree_inode = fs_info->btree_inode;
1034
1035         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1036         if (IS_ERR(buf))
1037                 return;
1038         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1039                                  buf, WAIT_NONE, 0);
1040         free_extent_buffer(buf);
1041 }
1042
1043 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
1044                          int mirror_num, struct extent_buffer **eb)
1045 {
1046         struct extent_buffer *buf = NULL;
1047         struct inode *btree_inode = fs_info->btree_inode;
1048         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1049         int ret;
1050
1051         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1052         if (IS_ERR(buf))
1053                 return 0;
1054
1055         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1056
1057         ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
1058                                        mirror_num);
1059         if (ret) {
1060                 free_extent_buffer(buf);
1061                 return ret;
1062         }
1063
1064         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1065                 free_extent_buffer(buf);
1066                 return -EIO;
1067         } else if (extent_buffer_uptodate(buf)) {
1068                 *eb = buf;
1069         } else {
1070                 free_extent_buffer(buf);
1071         }
1072         return 0;
1073 }
1074
1075 struct extent_buffer *btrfs_find_create_tree_block(
1076                                                 struct btrfs_fs_info *fs_info,
1077                                                 u64 bytenr)
1078 {
1079         if (btrfs_is_testing(fs_info))
1080                 return alloc_test_extent_buffer(fs_info, bytenr);
1081         return alloc_extent_buffer(fs_info, bytenr);
1082 }
1083
1084
1085 int btrfs_write_tree_block(struct extent_buffer *buf)
1086 {
1087         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1088                                         buf->start + buf->len - 1);
1089 }
1090
1091 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1092 {
1093         filemap_fdatawait_range(buf->pages[0]->mapping,
1094                                 buf->start, buf->start + buf->len - 1);
1095 }
1096
1097 /*
1098  * Read tree block at logical address @bytenr and do variant basic but critical
1099  * verification.
1100  *
1101  * @parent_transid:     expected transid of this tree block, skip check if 0
1102  * @level:              expected level, mandatory check
1103  * @first_key:          expected key in slot 0, skip check if NULL
1104  */
1105 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1106                                       u64 parent_transid, int level,
1107                                       struct btrfs_key *first_key)
1108 {
1109         struct extent_buffer *buf = NULL;
1110         int ret;
1111
1112         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1113         if (IS_ERR(buf))
1114                 return buf;
1115
1116         ret = btree_read_extent_buffer_pages(fs_info, buf, parent_transid,
1117                                              level, first_key);
1118         if (ret) {
1119                 free_extent_buffer(buf);
1120                 return ERR_PTR(ret);
1121         }
1122         return buf;
1123
1124 }
1125
1126 void clean_tree_block(struct btrfs_fs_info *fs_info,
1127                       struct extent_buffer *buf)
1128 {
1129         if (btrfs_header_generation(buf) ==
1130             fs_info->running_transaction->transid) {
1131                 btrfs_assert_tree_locked(buf);
1132
1133                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1134                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1135                                                  -buf->len,
1136                                                  fs_info->dirty_metadata_batch);
1137                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1138                         btrfs_set_lock_blocking(buf);
1139                         clear_extent_buffer_dirty(buf);
1140                 }
1141         }
1142 }
1143
1144 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1145 {
1146         struct btrfs_subvolume_writers *writers;
1147         int ret;
1148
1149         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1150         if (!writers)
1151                 return ERR_PTR(-ENOMEM);
1152
1153         ret = percpu_counter_init(&writers->counter, 0, GFP_NOFS);
1154         if (ret < 0) {
1155                 kfree(writers);
1156                 return ERR_PTR(ret);
1157         }
1158
1159         init_waitqueue_head(&writers->wait);
1160         return writers;
1161 }
1162
1163 static void
1164 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1165 {
1166         percpu_counter_destroy(&writers->counter);
1167         kfree(writers);
1168 }
1169
1170 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1171                          u64 objectid)
1172 {
1173         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1174         root->node = NULL;
1175         root->commit_root = NULL;
1176         root->state = 0;
1177         root->orphan_cleanup_state = 0;
1178
1179         root->objectid = objectid;
1180         root->last_trans = 0;
1181         root->highest_objectid = 0;
1182         root->nr_delalloc_inodes = 0;
1183         root->nr_ordered_extents = 0;
1184         root->name = NULL;
1185         root->inode_tree = RB_ROOT;
1186         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1187         root->block_rsv = NULL;
1188
1189         INIT_LIST_HEAD(&root->dirty_list);
1190         INIT_LIST_HEAD(&root->root_list);
1191         INIT_LIST_HEAD(&root->delalloc_inodes);
1192         INIT_LIST_HEAD(&root->delalloc_root);
1193         INIT_LIST_HEAD(&root->ordered_extents);
1194         INIT_LIST_HEAD(&root->ordered_root);
1195         INIT_LIST_HEAD(&root->logged_list[0]);
1196         INIT_LIST_HEAD(&root->logged_list[1]);
1197         spin_lock_init(&root->inode_lock);
1198         spin_lock_init(&root->delalloc_lock);
1199         spin_lock_init(&root->ordered_extent_lock);
1200         spin_lock_init(&root->accounting_lock);
1201         spin_lock_init(&root->log_extents_lock[0]);
1202         spin_lock_init(&root->log_extents_lock[1]);
1203         spin_lock_init(&root->qgroup_meta_rsv_lock);
1204         mutex_init(&root->objectid_mutex);
1205         mutex_init(&root->log_mutex);
1206         mutex_init(&root->ordered_extent_mutex);
1207         mutex_init(&root->delalloc_mutex);
1208         init_waitqueue_head(&root->log_writer_wait);
1209         init_waitqueue_head(&root->log_commit_wait[0]);
1210         init_waitqueue_head(&root->log_commit_wait[1]);
1211         INIT_LIST_HEAD(&root->log_ctxs[0]);
1212         INIT_LIST_HEAD(&root->log_ctxs[1]);
1213         atomic_set(&root->log_commit[0], 0);
1214         atomic_set(&root->log_commit[1], 0);
1215         atomic_set(&root->log_writers, 0);
1216         atomic_set(&root->log_batch, 0);
1217         refcount_set(&root->refs, 1);
1218         atomic_set(&root->will_be_snapshotted, 0);
1219         root->log_transid = 0;
1220         root->log_transid_committed = -1;
1221         root->last_log_commit = 0;
1222         if (!dummy)
1223                 extent_io_tree_init(&root->dirty_log_pages, NULL);
1224
1225         memset(&root->root_key, 0, sizeof(root->root_key));
1226         memset(&root->root_item, 0, sizeof(root->root_item));
1227         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1228         if (!dummy)
1229                 root->defrag_trans_start = fs_info->generation;
1230         else
1231                 root->defrag_trans_start = 0;
1232         root->root_key.objectid = objectid;
1233         root->anon_dev = 0;
1234
1235         spin_lock_init(&root->root_item_lock);
1236 }
1237
1238 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1239                 gfp_t flags)
1240 {
1241         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1242         if (root)
1243                 root->fs_info = fs_info;
1244         return root;
1245 }
1246
1247 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1248 /* Should only be used by the testing infrastructure */
1249 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1250 {
1251         struct btrfs_root *root;
1252
1253         if (!fs_info)
1254                 return ERR_PTR(-EINVAL);
1255
1256         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1257         if (!root)
1258                 return ERR_PTR(-ENOMEM);
1259
1260         /* We don't use the stripesize in selftest, set it as sectorsize */
1261         __setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1262         root->alloc_bytenr = 0;
1263
1264         return root;
1265 }
1266 #endif
1267
1268 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1269                                      struct btrfs_fs_info *fs_info,
1270                                      u64 objectid)
1271 {
1272         struct extent_buffer *leaf;
1273         struct btrfs_root *tree_root = fs_info->tree_root;
1274         struct btrfs_root *root;
1275         struct btrfs_key key;
1276         int ret = 0;
1277         uuid_le uuid = NULL_UUID_LE;
1278
1279         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1280         if (!root)
1281                 return ERR_PTR(-ENOMEM);
1282
1283         __setup_root(root, fs_info, objectid);
1284         root->root_key.objectid = objectid;
1285         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1286         root->root_key.offset = 0;
1287
1288         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1289         if (IS_ERR(leaf)) {
1290                 ret = PTR_ERR(leaf);
1291                 leaf = NULL;
1292                 goto fail;
1293         }
1294
1295         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1296         btrfs_set_header_bytenr(leaf, leaf->start);
1297         btrfs_set_header_generation(leaf, trans->transid);
1298         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1299         btrfs_set_header_owner(leaf, objectid);
1300         root->node = leaf;
1301
1302         write_extent_buffer_fsid(leaf, fs_info->fsid);
1303         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
1304         btrfs_mark_buffer_dirty(leaf);
1305
1306         root->commit_root = btrfs_root_node(root);
1307         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1308
1309         root->root_item.flags = 0;
1310         root->root_item.byte_limit = 0;
1311         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1312         btrfs_set_root_generation(&root->root_item, trans->transid);
1313         btrfs_set_root_level(&root->root_item, 0);
1314         btrfs_set_root_refs(&root->root_item, 1);
1315         btrfs_set_root_used(&root->root_item, leaf->len);
1316         btrfs_set_root_last_snapshot(&root->root_item, 0);
1317         btrfs_set_root_dirid(&root->root_item, 0);
1318         if (is_fstree(objectid))
1319                 uuid_le_gen(&uuid);
1320         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1321         root->root_item.drop_level = 0;
1322
1323         key.objectid = objectid;
1324         key.type = BTRFS_ROOT_ITEM_KEY;
1325         key.offset = 0;
1326         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1327         if (ret)
1328                 goto fail;
1329
1330         btrfs_tree_unlock(leaf);
1331
1332         return root;
1333
1334 fail:
1335         if (leaf) {
1336                 btrfs_tree_unlock(leaf);
1337                 free_extent_buffer(root->commit_root);
1338                 free_extent_buffer(leaf);
1339         }
1340         kfree(root);
1341
1342         return ERR_PTR(ret);
1343 }
1344
1345 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1346                                          struct btrfs_fs_info *fs_info)
1347 {
1348         struct btrfs_root *root;
1349         struct extent_buffer *leaf;
1350
1351         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1352         if (!root)
1353                 return ERR_PTR(-ENOMEM);
1354
1355         __setup_root(root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1356
1357         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1358         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1359         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1360
1361         /*
1362          * DON'T set REF_COWS for log trees
1363          *
1364          * log trees do not get reference counted because they go away
1365          * before a real commit is actually done.  They do store pointers
1366          * to file data extents, and those reference counts still get
1367          * updated (along with back refs to the log tree).
1368          */
1369
1370         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1371                         NULL, 0, 0, 0);
1372         if (IS_ERR(leaf)) {
1373                 kfree(root);
1374                 return ERR_CAST(leaf);
1375         }
1376
1377         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1378         btrfs_set_header_bytenr(leaf, leaf->start);
1379         btrfs_set_header_generation(leaf, trans->transid);
1380         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1381         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1382         root->node = leaf;
1383
1384         write_extent_buffer_fsid(root->node, fs_info->fsid);
1385         btrfs_mark_buffer_dirty(root->node);
1386         btrfs_tree_unlock(root->node);
1387         return root;
1388 }
1389
1390 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1391                              struct btrfs_fs_info *fs_info)
1392 {
1393         struct btrfs_root *log_root;
1394
1395         log_root = alloc_log_tree(trans, fs_info);
1396         if (IS_ERR(log_root))
1397                 return PTR_ERR(log_root);
1398         WARN_ON(fs_info->log_root_tree);
1399         fs_info->log_root_tree = log_root;
1400         return 0;
1401 }
1402
1403 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1404                        struct btrfs_root *root)
1405 {
1406         struct btrfs_fs_info *fs_info = root->fs_info;
1407         struct btrfs_root *log_root;
1408         struct btrfs_inode_item *inode_item;
1409
1410         log_root = alloc_log_tree(trans, fs_info);
1411         if (IS_ERR(log_root))
1412                 return PTR_ERR(log_root);
1413
1414         log_root->last_trans = trans->transid;
1415         log_root->root_key.offset = root->root_key.objectid;
1416
1417         inode_item = &log_root->root_item.inode;
1418         btrfs_set_stack_inode_generation(inode_item, 1);
1419         btrfs_set_stack_inode_size(inode_item, 3);
1420         btrfs_set_stack_inode_nlink(inode_item, 1);
1421         btrfs_set_stack_inode_nbytes(inode_item,
1422                                      fs_info->nodesize);
1423         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1424
1425         btrfs_set_root_node(&log_root->root_item, log_root->node);
1426
1427         WARN_ON(root->log_root);
1428         root->log_root = log_root;
1429         root->log_transid = 0;
1430         root->log_transid_committed = -1;
1431         root->last_log_commit = 0;
1432         return 0;
1433 }
1434
1435 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1436                                                struct btrfs_key *key)
1437 {
1438         struct btrfs_root *root;
1439         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1440         struct btrfs_path *path;
1441         u64 generation;
1442         int ret;
1443         int level;
1444
1445         path = btrfs_alloc_path();
1446         if (!path)
1447                 return ERR_PTR(-ENOMEM);
1448
1449         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1450         if (!root) {
1451                 ret = -ENOMEM;
1452                 goto alloc_fail;
1453         }
1454
1455         __setup_root(root, fs_info, key->objectid);
1456
1457         ret = btrfs_find_root(tree_root, key, path,
1458                               &root->root_item, &root->root_key);
1459         if (ret) {
1460                 if (ret > 0)
1461                         ret = -ENOENT;
1462                 goto find_fail;
1463         }
1464
1465         generation = btrfs_root_generation(&root->root_item);
1466         level = btrfs_root_level(&root->root_item);
1467         root->node = read_tree_block(fs_info,
1468                                      btrfs_root_bytenr(&root->root_item),
1469                                      generation, level, NULL);
1470         if (IS_ERR(root->node)) {
1471                 ret = PTR_ERR(root->node);
1472                 goto find_fail;
1473         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1474                 ret = -EIO;
1475                 free_extent_buffer(root->node);
1476                 goto find_fail;
1477         }
1478         root->commit_root = btrfs_root_node(root);
1479 out:
1480         btrfs_free_path(path);
1481         return root;
1482
1483 find_fail:
1484         kfree(root);
1485 alloc_fail:
1486         root = ERR_PTR(ret);
1487         goto out;
1488 }
1489
1490 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1491                                       struct btrfs_key *location)
1492 {
1493         struct btrfs_root *root;
1494
1495         root = btrfs_read_tree_root(tree_root, location);
1496         if (IS_ERR(root))
1497                 return root;
1498
1499         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1500                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1501                 btrfs_check_and_init_root_item(&root->root_item);
1502         }
1503
1504         return root;
1505 }
1506
1507 int btrfs_init_fs_root(struct btrfs_root *root)
1508 {
1509         int ret;
1510         struct btrfs_subvolume_writers *writers;
1511
1512         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1513         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1514                                         GFP_NOFS);
1515         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1516                 ret = -ENOMEM;
1517                 goto fail;
1518         }
1519
1520         writers = btrfs_alloc_subvolume_writers();
1521         if (IS_ERR(writers)) {
1522                 ret = PTR_ERR(writers);
1523                 goto fail;
1524         }
1525         root->subv_writers = writers;
1526
1527         btrfs_init_free_ino_ctl(root);
1528         spin_lock_init(&root->ino_cache_lock);
1529         init_waitqueue_head(&root->ino_cache_wait);
1530
1531         ret = get_anon_bdev(&root->anon_dev);
1532         if (ret)
1533                 goto fail;
1534
1535         mutex_lock(&root->objectid_mutex);
1536         ret = btrfs_find_highest_objectid(root,
1537                                         &root->highest_objectid);
1538         if (ret) {
1539                 mutex_unlock(&root->objectid_mutex);
1540                 goto fail;
1541         }
1542
1543         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1544
1545         mutex_unlock(&root->objectid_mutex);
1546
1547         return 0;
1548 fail:
1549         /* the caller is responsible to call free_fs_root */
1550         return ret;
1551 }
1552
1553 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1554                                         u64 root_id)
1555 {
1556         struct btrfs_root *root;
1557
1558         spin_lock(&fs_info->fs_roots_radix_lock);
1559         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1560                                  (unsigned long)root_id);
1561         spin_unlock(&fs_info->fs_roots_radix_lock);
1562         return root;
1563 }
1564
1565 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1566                          struct btrfs_root *root)
1567 {
1568         int ret;
1569
1570         ret = radix_tree_preload(GFP_NOFS);
1571         if (ret)
1572                 return ret;
1573
1574         spin_lock(&fs_info->fs_roots_radix_lock);
1575         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1576                                 (unsigned long)root->root_key.objectid,
1577                                 root);
1578         if (ret == 0)
1579                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1580         spin_unlock(&fs_info->fs_roots_radix_lock);
1581         radix_tree_preload_end();
1582
1583         return ret;
1584 }
1585
1586 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1587                                      struct btrfs_key *location,
1588                                      bool check_ref)
1589 {
1590         struct btrfs_root *root;
1591         struct btrfs_path *path;
1592         struct btrfs_key key;
1593         int ret;
1594
1595         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1596                 return fs_info->tree_root;
1597         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1598                 return fs_info->extent_root;
1599         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1600                 return fs_info->chunk_root;
1601         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1602                 return fs_info->dev_root;
1603         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1604                 return fs_info->csum_root;
1605         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1606                 return fs_info->quota_root ? fs_info->quota_root :
1607                                              ERR_PTR(-ENOENT);
1608         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1609                 return fs_info->uuid_root ? fs_info->uuid_root :
1610                                             ERR_PTR(-ENOENT);
1611         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1612                 return fs_info->free_space_root ? fs_info->free_space_root :
1613                                                   ERR_PTR(-ENOENT);
1614 again:
1615         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1616         if (root) {
1617                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1618                         return ERR_PTR(-ENOENT);
1619                 return root;
1620         }
1621
1622         root = btrfs_read_fs_root(fs_info->tree_root, location);
1623         if (IS_ERR(root))
1624                 return root;
1625
1626         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1627                 ret = -ENOENT;
1628                 goto fail;
1629         }
1630
1631         ret = btrfs_init_fs_root(root);
1632         if (ret)
1633                 goto fail;
1634
1635         path = btrfs_alloc_path();
1636         if (!path) {
1637                 ret = -ENOMEM;
1638                 goto fail;
1639         }
1640         key.objectid = BTRFS_ORPHAN_OBJECTID;
1641         key.type = BTRFS_ORPHAN_ITEM_KEY;
1642         key.offset = location->objectid;
1643
1644         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1645         btrfs_free_path(path);
1646         if (ret < 0)
1647                 goto fail;
1648         if (ret == 0)
1649                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1650
1651         ret = btrfs_insert_fs_root(fs_info, root);
1652         if (ret) {
1653                 if (ret == -EEXIST) {
1654                         free_fs_root(root);
1655                         goto again;
1656                 }
1657                 goto fail;
1658         }
1659         return root;
1660 fail:
1661         free_fs_root(root);
1662         return ERR_PTR(ret);
1663 }
1664
1665 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1666 {
1667         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1668         int ret = 0;
1669         struct btrfs_device *device;
1670         struct backing_dev_info *bdi;
1671
1672         rcu_read_lock();
1673         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1674                 if (!device->bdev)
1675                         continue;
1676                 bdi = device->bdev->bd_bdi;
1677                 if (bdi_congested(bdi, bdi_bits)) {
1678                         ret = 1;
1679                         break;
1680                 }
1681         }
1682         rcu_read_unlock();
1683         return ret;
1684 }
1685
1686 /*
1687  * called by the kthread helper functions to finally call the bio end_io
1688  * functions.  This is where read checksum verification actually happens
1689  */
1690 static void end_workqueue_fn(struct btrfs_work *work)
1691 {
1692         struct bio *bio;
1693         struct btrfs_end_io_wq *end_io_wq;
1694
1695         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1696         bio = end_io_wq->bio;
1697
1698         bio->bi_status = end_io_wq->status;
1699         bio->bi_private = end_io_wq->private;
1700         bio->bi_end_io = end_io_wq->end_io;
1701         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1702         bio_endio(bio);
1703 }
1704
1705 static int cleaner_kthread(void *arg)
1706 {
1707         struct btrfs_root *root = arg;
1708         struct btrfs_fs_info *fs_info = root->fs_info;
1709         int again;
1710         struct btrfs_trans_handle *trans;
1711
1712         do {
1713                 again = 0;
1714
1715                 /* Make the cleaner go to sleep early. */
1716                 if (btrfs_need_cleaner_sleep(fs_info))
1717                         goto sleep;
1718
1719                 /*
1720                  * Do not do anything if we might cause open_ctree() to block
1721                  * before we have finished mounting the filesystem.
1722                  */
1723                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1724                         goto sleep;
1725
1726                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1727                         goto sleep;
1728
1729                 /*
1730                  * Avoid the problem that we change the status of the fs
1731                  * during the above check and trylock.
1732                  */
1733                 if (btrfs_need_cleaner_sleep(fs_info)) {
1734                         mutex_unlock(&fs_info->cleaner_mutex);
1735                         goto sleep;
1736                 }
1737
1738                 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
1739                 btrfs_run_delayed_iputs(fs_info);
1740                 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
1741
1742                 again = btrfs_clean_one_deleted_snapshot(root);
1743                 mutex_unlock(&fs_info->cleaner_mutex);
1744
1745                 /*
1746                  * The defragger has dealt with the R/O remount and umount,
1747                  * needn't do anything special here.
1748                  */
1749                 btrfs_run_defrag_inodes(fs_info);
1750
1751                 /*
1752                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1753                  * with relocation (btrfs_relocate_chunk) and relocation
1754                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1755                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1756                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1757                  * unused block groups.
1758                  */
1759                 btrfs_delete_unused_bgs(fs_info);
1760 sleep:
1761                 if (!again) {
1762                         set_current_state(TASK_INTERRUPTIBLE);
1763                         if (!kthread_should_stop())
1764                                 schedule();
1765                         __set_current_state(TASK_RUNNING);
1766                 }
1767         } while (!kthread_should_stop());
1768
1769         /*
1770          * Transaction kthread is stopped before us and wakes us up.
1771          * However we might have started a new transaction and COWed some
1772          * tree blocks when deleting unused block groups for example. So
1773          * make sure we commit the transaction we started to have a clean
1774          * shutdown when evicting the btree inode - if it has dirty pages
1775          * when we do the final iput() on it, eviction will trigger a
1776          * writeback for it which will fail with null pointer dereferences
1777          * since work queues and other resources were already released and
1778          * destroyed by the time the iput/eviction/writeback is made.
1779          */
1780         trans = btrfs_attach_transaction(root);
1781         if (IS_ERR(trans)) {
1782                 if (PTR_ERR(trans) != -ENOENT)
1783                         btrfs_err(fs_info,
1784                                   "cleaner transaction attach returned %ld",
1785                                   PTR_ERR(trans));
1786         } else {
1787                 int ret;
1788
1789                 ret = btrfs_commit_transaction(trans);
1790                 if (ret)
1791                         btrfs_err(fs_info,
1792                                   "cleaner open transaction commit returned %d",
1793                                   ret);
1794         }
1795
1796         return 0;
1797 }
1798
1799 static int transaction_kthread(void *arg)
1800 {
1801         struct btrfs_root *root = arg;
1802         struct btrfs_fs_info *fs_info = root->fs_info;
1803         struct btrfs_trans_handle *trans;
1804         struct btrfs_transaction *cur;
1805         u64 transid;
1806         time64_t now;
1807         unsigned long delay;
1808         bool cannot_commit;
1809
1810         do {
1811                 cannot_commit = false;
1812                 delay = HZ * fs_info->commit_interval;
1813                 mutex_lock(&fs_info->transaction_kthread_mutex);
1814
1815                 spin_lock(&fs_info->trans_lock);
1816                 cur = fs_info->running_transaction;
1817                 if (!cur) {
1818                         spin_unlock(&fs_info->trans_lock);
1819                         goto sleep;
1820                 }
1821
1822                 now = ktime_get_real_seconds();
1823                 if (cur->state < TRANS_STATE_BLOCKED &&
1824                     !test_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags) &&
1825                     (now < cur->start_time ||
1826                      now - cur->start_time < fs_info->commit_interval)) {
1827                         spin_unlock(&fs_info->trans_lock);
1828                         delay = HZ * 5;
1829                         goto sleep;
1830                 }
1831                 transid = cur->transid;
1832                 spin_unlock(&fs_info->trans_lock);
1833
1834                 /* If the file system is aborted, this will always fail. */
1835                 trans = btrfs_attach_transaction(root);
1836                 if (IS_ERR(trans)) {
1837                         if (PTR_ERR(trans) != -ENOENT)
1838                                 cannot_commit = true;
1839                         goto sleep;
1840                 }
1841                 if (transid == trans->transid) {
1842                         btrfs_commit_transaction(trans);
1843                 } else {
1844                         btrfs_end_transaction(trans);
1845                 }
1846 sleep:
1847                 wake_up_process(fs_info->cleaner_kthread);
1848                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1849
1850                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1851                                       &fs_info->fs_state)))
1852                         btrfs_cleanup_transaction(fs_info);
1853                 if (!kthread_should_stop() &&
1854                                 (!btrfs_transaction_blocked(fs_info) ||
1855                                  cannot_commit))
1856                         schedule_timeout_interruptible(delay);
1857         } while (!kthread_should_stop());
1858         return 0;
1859 }
1860
1861 /*
1862  * this will find the highest generation in the array of
1863  * root backups.  The index of the highest array is returned,
1864  * or -1 if we can't find anything.
1865  *
1866  * We check to make sure the array is valid by comparing the
1867  * generation of the latest  root in the array with the generation
1868  * in the super block.  If they don't match we pitch it.
1869  */
1870 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1871 {
1872         u64 cur;
1873         int newest_index = -1;
1874         struct btrfs_root_backup *root_backup;
1875         int i;
1876
1877         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1878                 root_backup = info->super_copy->super_roots + i;
1879                 cur = btrfs_backup_tree_root_gen(root_backup);
1880                 if (cur == newest_gen)
1881                         newest_index = i;
1882         }
1883
1884         /* check to see if we actually wrapped around */
1885         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1886                 root_backup = info->super_copy->super_roots;
1887                 cur = btrfs_backup_tree_root_gen(root_backup);
1888                 if (cur == newest_gen)
1889                         newest_index = 0;
1890         }
1891         return newest_index;
1892 }
1893
1894
1895 /*
1896  * find the oldest backup so we know where to store new entries
1897  * in the backup array.  This will set the backup_root_index
1898  * field in the fs_info struct
1899  */
1900 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1901                                      u64 newest_gen)
1902 {
1903         int newest_index = -1;
1904
1905         newest_index = find_newest_super_backup(info, newest_gen);
1906         /* if there was garbage in there, just move along */
1907         if (newest_index == -1) {
1908                 info->backup_root_index = 0;
1909         } else {
1910                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1911         }
1912 }
1913
1914 /*
1915  * copy all the root pointers into the super backup array.
1916  * this will bump the backup pointer by one when it is
1917  * done
1918  */
1919 static void backup_super_roots(struct btrfs_fs_info *info)
1920 {
1921         int next_backup;
1922         struct btrfs_root_backup *root_backup;
1923         int last_backup;
1924
1925         next_backup = info->backup_root_index;
1926         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1927                 BTRFS_NUM_BACKUP_ROOTS;
1928
1929         /*
1930          * just overwrite the last backup if we're at the same generation
1931          * this happens only at umount
1932          */
1933         root_backup = info->super_for_commit->super_roots + last_backup;
1934         if (btrfs_backup_tree_root_gen(root_backup) ==
1935             btrfs_header_generation(info->tree_root->node))
1936                 next_backup = last_backup;
1937
1938         root_backup = info->super_for_commit->super_roots + next_backup;
1939
1940         /*
1941          * make sure all of our padding and empty slots get zero filled
1942          * regardless of which ones we use today
1943          */
1944         memset(root_backup, 0, sizeof(*root_backup));
1945
1946         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1947
1948         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1949         btrfs_set_backup_tree_root_gen(root_backup,
1950                                btrfs_header_generation(info->tree_root->node));
1951
1952         btrfs_set_backup_tree_root_level(root_backup,
1953                                btrfs_header_level(info->tree_root->node));
1954
1955         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1956         btrfs_set_backup_chunk_root_gen(root_backup,
1957                                btrfs_header_generation(info->chunk_root->node));
1958         btrfs_set_backup_chunk_root_level(root_backup,
1959                                btrfs_header_level(info->chunk_root->node));
1960
1961         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1962         btrfs_set_backup_extent_root_gen(root_backup,
1963                                btrfs_header_generation(info->extent_root->node));
1964         btrfs_set_backup_extent_root_level(root_backup,
1965                                btrfs_header_level(info->extent_root->node));
1966
1967         /*
1968          * we might commit during log recovery, which happens before we set
1969          * the fs_root.  Make sure it is valid before we fill it in.
1970          */
1971         if (info->fs_root && info->fs_root->node) {
1972                 btrfs_set_backup_fs_root(root_backup,
1973                                          info->fs_root->node->start);
1974                 btrfs_set_backup_fs_root_gen(root_backup,
1975                                btrfs_header_generation(info->fs_root->node));
1976                 btrfs_set_backup_fs_root_level(root_backup,
1977                                btrfs_header_level(info->fs_root->node));
1978         }
1979
1980         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1981         btrfs_set_backup_dev_root_gen(root_backup,
1982                                btrfs_header_generation(info->dev_root->node));
1983         btrfs_set_backup_dev_root_level(root_backup,
1984                                        btrfs_header_level(info->dev_root->node));
1985
1986         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1987         btrfs_set_backup_csum_root_gen(root_backup,
1988                                btrfs_header_generation(info->csum_root->node));
1989         btrfs_set_backup_csum_root_level(root_backup,
1990                                btrfs_header_level(info->csum_root->node));
1991
1992         btrfs_set_backup_total_bytes(root_backup,
1993                              btrfs_super_total_bytes(info->super_copy));
1994         btrfs_set_backup_bytes_used(root_backup,
1995                              btrfs_super_bytes_used(info->super_copy));
1996         btrfs_set_backup_num_devices(root_backup,
1997                              btrfs_super_num_devices(info->super_copy));
1998
1999         /*
2000          * if we don't copy this out to the super_copy, it won't get remembered
2001          * for the next commit
2002          */
2003         memcpy(&info->super_copy->super_roots,
2004                &info->super_for_commit->super_roots,
2005                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2006 }
2007
2008 /*
2009  * this copies info out of the root backup array and back into
2010  * the in-memory super block.  It is meant to help iterate through
2011  * the array, so you send it the number of backups you've already
2012  * tried and the last backup index you used.
2013  *
2014  * this returns -1 when it has tried all the backups
2015  */
2016 static noinline int next_root_backup(struct btrfs_fs_info *info,
2017                                      struct btrfs_super_block *super,
2018                                      int *num_backups_tried, int *backup_index)
2019 {
2020         struct btrfs_root_backup *root_backup;
2021         int newest = *backup_index;
2022
2023         if (*num_backups_tried == 0) {
2024                 u64 gen = btrfs_super_generation(super);
2025
2026                 newest = find_newest_super_backup(info, gen);
2027                 if (newest == -1)
2028                         return -1;
2029
2030                 *backup_index = newest;
2031                 *num_backups_tried = 1;
2032         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2033                 /* we've tried all the backups, all done */
2034                 return -1;
2035         } else {
2036                 /* jump to the next oldest backup */
2037                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2038                         BTRFS_NUM_BACKUP_ROOTS;
2039                 *backup_index = newest;
2040                 *num_backups_tried += 1;
2041         }
2042         root_backup = super->super_roots + newest;
2043
2044         btrfs_set_super_generation(super,
2045                                    btrfs_backup_tree_root_gen(root_backup));
2046         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2047         btrfs_set_super_root_level(super,
2048                                    btrfs_backup_tree_root_level(root_backup));
2049         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2050
2051         /*
2052          * fixme: the total bytes and num_devices need to match or we should
2053          * need a fsck
2054          */
2055         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2056         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2057         return 0;
2058 }
2059
2060 /* helper to cleanup workers */
2061 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2062 {
2063         btrfs_destroy_workqueue(fs_info->fixup_workers);
2064         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2065         btrfs_destroy_workqueue(fs_info->workers);
2066         btrfs_destroy_workqueue(fs_info->endio_workers);
2067         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2068         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2069         btrfs_destroy_workqueue(fs_info->rmw_workers);
2070         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2071         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2072         btrfs_destroy_workqueue(fs_info->submit_workers);
2073         btrfs_destroy_workqueue(fs_info->delayed_workers);
2074         btrfs_destroy_workqueue(fs_info->caching_workers);
2075         btrfs_destroy_workqueue(fs_info->readahead_workers);
2076         btrfs_destroy_workqueue(fs_info->flush_workers);
2077         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2078         btrfs_destroy_workqueue(fs_info->extent_workers);
2079         /*
2080          * Now that all other work queues are destroyed, we can safely destroy
2081          * the queues used for metadata I/O, since tasks from those other work
2082          * queues can do metadata I/O operations.
2083          */
2084         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2085         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2086 }
2087
2088 static void free_root_extent_buffers(struct btrfs_root *root)
2089 {
2090         if (root) {
2091                 free_extent_buffer(root->node);
2092                 free_extent_buffer(root->commit_root);
2093                 root->node = NULL;
2094                 root->commit_root = NULL;
2095         }
2096 }
2097
2098 /* helper to cleanup tree roots */
2099 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2100 {
2101         free_root_extent_buffers(info->tree_root);
2102
2103         free_root_extent_buffers(info->dev_root);
2104         free_root_extent_buffers(info->extent_root);
2105         free_root_extent_buffers(info->csum_root);
2106         free_root_extent_buffers(info->quota_root);
2107         free_root_extent_buffers(info->uuid_root);
2108         if (chunk_root)
2109                 free_root_extent_buffers(info->chunk_root);
2110         free_root_extent_buffers(info->free_space_root);
2111 }
2112
2113 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2114 {
2115         int ret;
2116         struct btrfs_root *gang[8];
2117         int i;
2118
2119         while (!list_empty(&fs_info->dead_roots)) {
2120                 gang[0] = list_entry(fs_info->dead_roots.next,
2121                                      struct btrfs_root, root_list);
2122                 list_del(&gang[0]->root_list);
2123
2124                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2125                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2126                 } else {
2127                         free_extent_buffer(gang[0]->node);
2128                         free_extent_buffer(gang[0]->commit_root);
2129                         btrfs_put_fs_root(gang[0]);
2130                 }
2131         }
2132
2133         while (1) {
2134                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2135                                              (void **)gang, 0,
2136                                              ARRAY_SIZE(gang));
2137                 if (!ret)
2138                         break;
2139                 for (i = 0; i < ret; i++)
2140                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2141         }
2142
2143         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2144                 btrfs_free_log_root_tree(NULL, fs_info);
2145                 btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
2146         }
2147 }
2148
2149 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2150 {
2151         mutex_init(&fs_info->scrub_lock);
2152         atomic_set(&fs_info->scrubs_running, 0);
2153         atomic_set(&fs_info->scrub_pause_req, 0);
2154         atomic_set(&fs_info->scrubs_paused, 0);
2155         atomic_set(&fs_info->scrub_cancel_req, 0);
2156         init_waitqueue_head(&fs_info->scrub_pause_wait);
2157         fs_info->scrub_workers_refcnt = 0;
2158 }
2159
2160 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2161 {
2162         spin_lock_init(&fs_info->balance_lock);
2163         mutex_init(&fs_info->balance_mutex);
2164         atomic_set(&fs_info->balance_pause_req, 0);
2165         atomic_set(&fs_info->balance_cancel_req, 0);
2166         fs_info->balance_ctl = NULL;
2167         init_waitqueue_head(&fs_info->balance_wait_q);
2168 }
2169
2170 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2171 {
2172         struct inode *inode = fs_info->btree_inode;
2173
2174         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2175         set_nlink(inode, 1);
2176         /*
2177          * we set the i_size on the btree inode to the max possible int.
2178          * the real end of the address space is determined by all of
2179          * the devices in the system
2180          */
2181         inode->i_size = OFFSET_MAX;
2182         inode->i_mapping->a_ops = &btree_aops;
2183
2184         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2185         extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode);
2186         BTRFS_I(inode)->io_tree.track_uptodate = 0;
2187         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2188
2189         BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
2190
2191         BTRFS_I(inode)->root = fs_info->tree_root;
2192         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2193         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2194         btrfs_insert_inode_hash(inode);
2195 }
2196
2197 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2198 {
2199         fs_info->dev_replace.lock_owner = 0;
2200         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2201         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2202         rwlock_init(&fs_info->dev_replace.lock);
2203         atomic_set(&fs_info->dev_replace.read_locks, 0);
2204         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2205         init_waitqueue_head(&fs_info->replace_wait);
2206         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2207 }
2208
2209 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2210 {
2211         spin_lock_init(&fs_info->qgroup_lock);
2212         mutex_init(&fs_info->qgroup_ioctl_lock);
2213         fs_info->qgroup_tree = RB_ROOT;
2214         fs_info->qgroup_op_tree = RB_ROOT;
2215         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2216         fs_info->qgroup_seq = 1;
2217         fs_info->qgroup_ulist = NULL;
2218         fs_info->qgroup_rescan_running = false;
2219         mutex_init(&fs_info->qgroup_rescan_lock);
2220 }
2221
2222 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2223                 struct btrfs_fs_devices *fs_devices)
2224 {
2225         u32 max_active = fs_info->thread_pool_size;
2226         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2227
2228         fs_info->workers =
2229                 btrfs_alloc_workqueue(fs_info, "worker",
2230                                       flags | WQ_HIGHPRI, max_active, 16);
2231
2232         fs_info->delalloc_workers =
2233                 btrfs_alloc_workqueue(fs_info, "delalloc",
2234                                       flags, max_active, 2);
2235
2236         fs_info->flush_workers =
2237                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2238                                       flags, max_active, 0);
2239
2240         fs_info->caching_workers =
2241                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2242
2243         /*
2244          * a higher idle thresh on the submit workers makes it much more
2245          * likely that bios will be send down in a sane order to the
2246          * devices
2247          */
2248         fs_info->submit_workers =
2249                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2250                                       min_t(u64, fs_devices->num_devices,
2251                                             max_active), 64);
2252
2253         fs_info->fixup_workers =
2254                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2255
2256         /*
2257          * endios are largely parallel and should have a very
2258          * low idle thresh
2259          */
2260         fs_info->endio_workers =
2261                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2262         fs_info->endio_meta_workers =
2263                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2264                                       max_active, 4);
2265         fs_info->endio_meta_write_workers =
2266                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2267                                       max_active, 2);
2268         fs_info->endio_raid56_workers =
2269                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2270                                       max_active, 4);
2271         fs_info->endio_repair_workers =
2272                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2273         fs_info->rmw_workers =
2274                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2275         fs_info->endio_write_workers =
2276                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2277                                       max_active, 2);
2278         fs_info->endio_freespace_worker =
2279                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2280                                       max_active, 0);
2281         fs_info->delayed_workers =
2282                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2283                                       max_active, 0);
2284         fs_info->readahead_workers =
2285                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2286                                       max_active, 2);
2287         fs_info->qgroup_rescan_workers =
2288                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2289         fs_info->extent_workers =
2290                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2291                                       min_t(u64, fs_devices->num_devices,
2292                                             max_active), 8);
2293
2294         if (!(fs_info->workers && fs_info->delalloc_workers &&
2295               fs_info->submit_workers && fs_info->flush_workers &&
2296               fs_info->endio_workers && fs_info->endio_meta_workers &&
2297               fs_info->endio_meta_write_workers &&
2298               fs_info->endio_repair_workers &&
2299               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2300               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2301               fs_info->caching_workers && fs_info->readahead_workers &&
2302               fs_info->fixup_workers && fs_info->delayed_workers &&
2303               fs_info->extent_workers &&
2304               fs_info->qgroup_rescan_workers)) {
2305                 return -ENOMEM;
2306         }
2307
2308         return 0;
2309 }
2310
2311 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2312                             struct btrfs_fs_devices *fs_devices)
2313 {
2314         int ret;
2315         struct btrfs_root *log_tree_root;
2316         struct btrfs_super_block *disk_super = fs_info->super_copy;
2317         u64 bytenr = btrfs_super_log_root(disk_super);
2318         int level = btrfs_super_log_root_level(disk_super);
2319
2320         if (fs_devices->rw_devices == 0) {
2321                 btrfs_warn(fs_info, "log replay required on RO media");
2322                 return -EIO;
2323         }
2324
2325         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2326         if (!log_tree_root)
2327                 return -ENOMEM;
2328
2329         __setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2330
2331         log_tree_root->node = read_tree_block(fs_info, bytenr,
2332                                               fs_info->generation + 1,
2333                                               level, NULL);
2334         if (IS_ERR(log_tree_root->node)) {
2335                 btrfs_warn(fs_info, "failed to read log tree");
2336                 ret = PTR_ERR(log_tree_root->node);
2337                 kfree(log_tree_root);
2338                 return ret;
2339         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2340                 btrfs_err(fs_info, "failed to read log tree");
2341                 free_extent_buffer(log_tree_root->node);
2342                 kfree(log_tree_root);
2343                 return -EIO;
2344         }
2345         /* returns with log_tree_root freed on success */
2346         ret = btrfs_recover_log_trees(log_tree_root);
2347         if (ret) {
2348                 btrfs_handle_fs_error(fs_info, ret,
2349                                       "Failed to recover log tree");
2350                 free_extent_buffer(log_tree_root->node);
2351                 kfree(log_tree_root);
2352                 return ret;
2353         }
2354
2355         if (sb_rdonly(fs_info->sb)) {
2356                 ret = btrfs_commit_super(fs_info);
2357                 if (ret)
2358                         return ret;
2359         }
2360
2361         return 0;
2362 }
2363
2364 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2365 {
2366         struct btrfs_root *tree_root = fs_info->tree_root;
2367         struct btrfs_root *root;
2368         struct btrfs_key location;
2369         int ret;
2370
2371         BUG_ON(!fs_info->tree_root);
2372
2373         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2374         location.type = BTRFS_ROOT_ITEM_KEY;
2375         location.offset = 0;
2376
2377         root = btrfs_read_tree_root(tree_root, &location);
2378         if (IS_ERR(root)) {
2379                 ret = PTR_ERR(root);
2380                 goto out;
2381         }
2382         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2383         fs_info->extent_root = root;
2384
2385         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2386         root = btrfs_read_tree_root(tree_root, &location);
2387         if (IS_ERR(root)) {
2388                 ret = PTR_ERR(root);
2389                 goto out;
2390         }
2391         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2392         fs_info->dev_root = root;
2393         btrfs_init_devices_late(fs_info);
2394
2395         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2396         root = btrfs_read_tree_root(tree_root, &location);
2397         if (IS_ERR(root)) {
2398                 ret = PTR_ERR(root);
2399                 goto out;
2400         }
2401         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2402         fs_info->csum_root = root;
2403
2404         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2405         root = btrfs_read_tree_root(tree_root, &location);
2406         if (!IS_ERR(root)) {
2407                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2408                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2409                 fs_info->quota_root = root;
2410         }
2411
2412         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2413         root = btrfs_read_tree_root(tree_root, &location);
2414         if (IS_ERR(root)) {
2415                 ret = PTR_ERR(root);
2416                 if (ret != -ENOENT)
2417                         goto out;
2418         } else {
2419                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2420                 fs_info->uuid_root = root;
2421         }
2422
2423         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2424                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2425                 root = btrfs_read_tree_root(tree_root, &location);
2426                 if (IS_ERR(root)) {
2427                         ret = PTR_ERR(root);
2428                         goto out;
2429                 }
2430                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2431                 fs_info->free_space_root = root;
2432         }
2433
2434         return 0;
2435 out:
2436         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2437                    location.objectid, ret);
2438         return ret;
2439 }
2440
2441 /*
2442  * Real super block validation
2443  * NOTE: super csum type and incompat features will not be checked here.
2444  *
2445  * @sb:         super block to check
2446  * @mirror_num: the super block number to check its bytenr:
2447  *              0       the primary (1st) sb
2448  *              1, 2    2nd and 3rd backup copy
2449  *             -1       skip bytenr check
2450  */
2451 static int validate_super(struct btrfs_fs_info *fs_info,
2452                             struct btrfs_super_block *sb, int mirror_num)
2453 {
2454         u64 nodesize = btrfs_super_nodesize(sb);
2455         u64 sectorsize = btrfs_super_sectorsize(sb);
2456         int ret = 0;
2457
2458         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2459                 btrfs_err(fs_info, "no valid FS found");
2460                 ret = -EINVAL;
2461         }
2462         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2463                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2464                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2465                 ret = -EINVAL;
2466         }
2467         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2468                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2469                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2470                 ret = -EINVAL;
2471         }
2472         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2473                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2474                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2475                 ret = -EINVAL;
2476         }
2477         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2478                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2479                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2480                 ret = -EINVAL;
2481         }
2482
2483         /*
2484          * Check sectorsize and nodesize first, other check will need it.
2485          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2486          */
2487         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2488             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2489                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2490                 ret = -EINVAL;
2491         }
2492         /* Only PAGE SIZE is supported yet */
2493         if (sectorsize != PAGE_SIZE) {
2494                 btrfs_err(fs_info,
2495                         "sectorsize %llu not supported yet, only support %lu",
2496                         sectorsize, PAGE_SIZE);
2497                 ret = -EINVAL;
2498         }
2499         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2500             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2501                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2502                 ret = -EINVAL;
2503         }
2504         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2505                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2506                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2507                 ret = -EINVAL;
2508         }
2509
2510         /* Root alignment check */
2511         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2512                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2513                            btrfs_super_root(sb));
2514                 ret = -EINVAL;
2515         }
2516         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2517                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2518                            btrfs_super_chunk_root(sb));
2519                 ret = -EINVAL;
2520         }
2521         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2522                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2523                            btrfs_super_log_root(sb));
2524                 ret = -EINVAL;
2525         }
2526
2527         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) {
2528                 btrfs_err(fs_info,
2529                            "dev_item UUID does not match fsid: %pU != %pU",
2530                            fs_info->fsid, sb->dev_item.fsid);
2531                 ret = -EINVAL;
2532         }
2533
2534         /*
2535          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2536          * done later
2537          */
2538         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2539                 btrfs_err(fs_info, "bytes_used is too small %llu",
2540                           btrfs_super_bytes_used(sb));
2541                 ret = -EINVAL;
2542         }
2543         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2544                 btrfs_err(fs_info, "invalid stripesize %u",
2545                           btrfs_super_stripesize(sb));
2546                 ret = -EINVAL;
2547         }
2548         if (btrfs_super_num_devices(sb) > (1UL << 31))
2549                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2550                            btrfs_super_num_devices(sb));
2551         if (btrfs_super_num_devices(sb) == 0) {
2552                 btrfs_err(fs_info, "number of devices is 0");
2553                 ret = -EINVAL;
2554         }
2555
2556         if (mirror_num >= 0 &&
2557             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2558                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2559                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2560                 ret = -EINVAL;
2561         }
2562
2563         /*
2564          * Obvious sys_chunk_array corruptions, it must hold at least one key
2565          * and one chunk
2566          */
2567         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2568                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2569                           btrfs_super_sys_array_size(sb),
2570                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2571                 ret = -EINVAL;
2572         }
2573         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2574                         + sizeof(struct btrfs_chunk)) {
2575                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2576                           btrfs_super_sys_array_size(sb),
2577                           sizeof(struct btrfs_disk_key)
2578                           + sizeof(struct btrfs_chunk));
2579                 ret = -EINVAL;
2580         }
2581
2582         /*
2583          * The generation is a global counter, we'll trust it more than the others
2584          * but it's still possible that it's the one that's wrong.
2585          */
2586         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2587                 btrfs_warn(fs_info,
2588                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2589                         btrfs_super_generation(sb),
2590                         btrfs_super_chunk_root_generation(sb));
2591         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2592             && btrfs_super_cache_generation(sb) != (u64)-1)
2593                 btrfs_warn(fs_info,
2594                         "suspicious: generation < cache_generation: %llu < %llu",
2595                         btrfs_super_generation(sb),
2596                         btrfs_super_cache_generation(sb));
2597
2598         return ret;
2599 }
2600
2601 /*
2602  * Validation of super block at mount time.
2603  * Some checks already done early at mount time, like csum type and incompat
2604  * flags will be skipped.
2605  */
2606 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2607 {
2608         return validate_super(fs_info, fs_info->super_copy, 0);
2609 }
2610
2611 /*
2612  * Validation of super block at write time.
2613  * Some checks like bytenr check will be skipped as their values will be
2614  * overwritten soon.
2615  * Extra checks like csum type and incompat flags will be done here.
2616  */
2617 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2618                                       struct btrfs_super_block *sb)
2619 {
2620         int ret;
2621
2622         ret = validate_super(fs_info, sb, -1);
2623         if (ret < 0)
2624                 goto out;
2625         if (btrfs_super_csum_type(sb) != BTRFS_CSUM_TYPE_CRC32) {
2626                 ret = -EUCLEAN;
2627                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2628                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2629                 goto out;
2630         }
2631         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2632                 ret = -EUCLEAN;
2633                 btrfs_err(fs_info,
2634                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2635                           btrfs_super_incompat_flags(sb),
2636                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2637                 goto out;
2638         }
2639 out:
2640         if (ret < 0)
2641                 btrfs_err(fs_info,
2642                 "super block corruption detected before writing it to disk");
2643         return ret;
2644 }
2645
2646 int open_ctree(struct super_block *sb,
2647                struct btrfs_fs_devices *fs_devices,
2648                char *options)
2649 {
2650         u32 sectorsize;
2651         u32 nodesize;
2652         u32 stripesize;
2653         u64 generation;
2654         u64 features;
2655         struct btrfs_key location;
2656         struct buffer_head *bh;
2657         struct btrfs_super_block *disk_super;
2658         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2659         struct btrfs_root *tree_root;
2660         struct btrfs_root *chunk_root;
2661         int ret;
2662         int err = -EINVAL;
2663         int num_backups_tried = 0;
2664         int backup_index = 0;
2665         int clear_free_space_tree = 0;
2666         int level;
2667
2668         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2669         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2670         if (!tree_root || !chunk_root) {
2671                 err = -ENOMEM;
2672                 goto fail;
2673         }
2674
2675         ret = init_srcu_struct(&fs_info->subvol_srcu);
2676         if (ret) {
2677                 err = ret;
2678                 goto fail;
2679         }
2680
2681         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2682         if (ret) {
2683                 err = ret;
2684                 goto fail_srcu;
2685         }
2686         fs_info->dirty_metadata_batch = PAGE_SIZE *
2687                                         (1 + ilog2(nr_cpu_ids));
2688
2689         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2690         if (ret) {
2691                 err = ret;
2692                 goto fail_dirty_metadata_bytes;
2693         }
2694
2695         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2696         if (ret) {
2697                 err = ret;
2698                 goto fail_delalloc_bytes;
2699         }
2700
2701         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2702         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2703         INIT_LIST_HEAD(&fs_info->trans_list);
2704         INIT_LIST_HEAD(&fs_info->dead_roots);
2705         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2706         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2707         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2708         INIT_LIST_HEAD(&fs_info->pending_raid_kobjs);
2709         spin_lock_init(&fs_info->pending_raid_kobjs_lock);
2710         spin_lock_init(&fs_info->delalloc_root_lock);
2711         spin_lock_init(&fs_info->trans_lock);
2712         spin_lock_init(&fs_info->fs_roots_radix_lock);
2713         spin_lock_init(&fs_info->delayed_iput_lock);
2714         spin_lock_init(&fs_info->defrag_inodes_lock);
2715         spin_lock_init(&fs_info->tree_mod_seq_lock);
2716         spin_lock_init(&fs_info->super_lock);
2717         spin_lock_init(&fs_info->qgroup_op_lock);
2718         spin_lock_init(&fs_info->buffer_lock);
2719         spin_lock_init(&fs_info->unused_bgs_lock);
2720         rwlock_init(&fs_info->tree_mod_log_lock);
2721         mutex_init(&fs_info->unused_bg_unpin_mutex);
2722         mutex_init(&fs_info->delete_unused_bgs_mutex);
2723         mutex_init(&fs_info->reloc_mutex);
2724         mutex_init(&fs_info->delalloc_root_mutex);
2725         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2726         seqlock_init(&fs_info->profiles_lock);
2727
2728         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2729         INIT_LIST_HEAD(&fs_info->space_info);
2730         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2731         INIT_LIST_HEAD(&fs_info->unused_bgs);
2732         btrfs_mapping_init(&fs_info->mapping_tree);
2733         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2734                              BTRFS_BLOCK_RSV_GLOBAL);
2735         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2736         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2737         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2738         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2739                              BTRFS_BLOCK_RSV_DELOPS);
2740         atomic_set(&fs_info->async_delalloc_pages, 0);
2741         atomic_set(&fs_info->defrag_running, 0);
2742         atomic_set(&fs_info->qgroup_op_seq, 0);
2743         atomic_set(&fs_info->reada_works_cnt, 0);
2744         atomic64_set(&fs_info->tree_mod_seq, 0);
2745         fs_info->sb = sb;
2746         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2747         fs_info->metadata_ratio = 0;
2748         fs_info->defrag_inodes = RB_ROOT;
2749         atomic64_set(&fs_info->free_chunk_space, 0);
2750         fs_info->tree_mod_log = RB_ROOT;
2751         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2752         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2753         /* readahead state */
2754         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2755         spin_lock_init(&fs_info->reada_lock);
2756         btrfs_init_ref_verify(fs_info);
2757
2758         fs_info->thread_pool_size = min_t(unsigned long,
2759                                           num_online_cpus() + 2, 8);
2760
2761         INIT_LIST_HEAD(&fs_info->ordered_roots);
2762         spin_lock_init(&fs_info->ordered_root_lock);
2763
2764         fs_info->btree_inode = new_inode(sb);
2765         if (!fs_info->btree_inode) {
2766                 err = -ENOMEM;
2767                 goto fail_bio_counter;
2768         }
2769         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2770
2771         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2772                                         GFP_KERNEL);
2773         if (!fs_info->delayed_root) {
2774                 err = -ENOMEM;
2775                 goto fail_iput;
2776         }
2777         btrfs_init_delayed_root(fs_info->delayed_root);
2778
2779         btrfs_init_scrub(fs_info);
2780 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2781         fs_info->check_integrity_print_mask = 0;
2782 #endif
2783         btrfs_init_balance(fs_info);
2784         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2785
2786         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2787         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
2788
2789         btrfs_init_btree_inode(fs_info);
2790
2791         spin_lock_init(&fs_info->block_group_cache_lock);
2792         fs_info->block_group_cache_tree = RB_ROOT;
2793         fs_info->first_logical_byte = (u64)-1;
2794
2795         extent_io_tree_init(&fs_info->freed_extents[0], NULL);
2796         extent_io_tree_init(&fs_info->freed_extents[1], NULL);
2797         fs_info->pinned_extents = &fs_info->freed_extents[0];
2798         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2799
2800         mutex_init(&fs_info->ordered_operations_mutex);
2801         mutex_init(&fs_info->tree_log_mutex);
2802         mutex_init(&fs_info->chunk_mutex);
2803         mutex_init(&fs_info->transaction_kthread_mutex);
2804         mutex_init(&fs_info->cleaner_mutex);
2805         mutex_init(&fs_info->ro_block_group_mutex);
2806         init_rwsem(&fs_info->commit_root_sem);
2807         init_rwsem(&fs_info->cleanup_work_sem);
2808         init_rwsem(&fs_info->subvol_sem);
2809         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2810
2811         btrfs_init_dev_replace_locks(fs_info);
2812         btrfs_init_qgroup(fs_info);
2813
2814         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2815         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2816
2817         init_waitqueue_head(&fs_info->transaction_throttle);
2818         init_waitqueue_head(&fs_info->transaction_wait);
2819         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2820         init_waitqueue_head(&fs_info->async_submit_wait);
2821
2822         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2823
2824         /* Usable values until the real ones are cached from the superblock */
2825         fs_info->nodesize = 4096;
2826         fs_info->sectorsize = 4096;
2827         fs_info->stripesize = 4096;
2828
2829         ret = btrfs_alloc_stripe_hash_table(fs_info);
2830         if (ret) {
2831                 err = ret;
2832                 goto fail_alloc;
2833         }
2834
2835         __setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
2836
2837         invalidate_bdev(fs_devices->latest_bdev);
2838
2839         /*
2840          * Read super block and check the signature bytes only
2841          */
2842         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2843         if (IS_ERR(bh)) {
2844                 err = PTR_ERR(bh);
2845                 goto fail_alloc;
2846         }
2847
2848         /*
2849          * We want to check superblock checksum, the type is stored inside.
2850          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2851          */
2852         if (btrfs_check_super_csum(fs_info, bh->b_data)) {
2853                 btrfs_err(fs_info, "superblock checksum mismatch");
2854                 err = -EINVAL;
2855                 brelse(bh);
2856                 goto fail_alloc;
2857         }
2858
2859         /*
2860          * super_copy is zeroed at allocation time and we never touch the
2861          * following bytes up to INFO_SIZE, the checksum is calculated from
2862          * the whole block of INFO_SIZE
2863          */
2864         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2865         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2866                sizeof(*fs_info->super_for_commit));
2867         brelse(bh);
2868
2869         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2870
2871         ret = btrfs_validate_mount_super(fs_info);
2872         if (ret) {
2873                 btrfs_err(fs_info, "superblock contains fatal errors");
2874                 err = -EINVAL;
2875                 goto fail_alloc;
2876         }
2877
2878         disk_super = fs_info->super_copy;
2879         if (!btrfs_super_root(disk_super))
2880                 goto fail_alloc;
2881
2882         /* check FS state, whether FS is broken. */
2883         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2884                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2885
2886         /*
2887          * run through our array of backup supers and setup
2888          * our ring pointer to the oldest one
2889          */
2890         generation = btrfs_super_generation(disk_super);
2891         find_oldest_super_backup(fs_info, generation);
2892
2893         /*
2894          * In the long term, we'll store the compression type in the super
2895          * block, and it'll be used for per file compression control.
2896          */
2897         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2898
2899         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
2900         if (ret) {
2901                 err = ret;
2902                 goto fail_alloc;
2903         }
2904
2905         features = btrfs_super_incompat_flags(disk_super) &
2906                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2907         if (features) {
2908                 btrfs_err(fs_info,
2909                     "cannot mount because of unsupported optional features (%llx)",
2910                     features);
2911                 err = -EINVAL;
2912                 goto fail_alloc;
2913         }
2914
2915         features = btrfs_super_incompat_flags(disk_super);
2916         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2917         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
2918                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2919         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
2920                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
2921
2922         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2923                 btrfs_info(fs_info, "has skinny extents");
2924
2925         /*
2926          * flag our filesystem as having big metadata blocks if
2927          * they are bigger than the page size
2928          */
2929         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2930                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2931                         btrfs_info(fs_info,
2932                                 "flagging fs with big metadata feature");
2933                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2934         }
2935
2936         nodesize = btrfs_super_nodesize(disk_super);
2937         sectorsize = btrfs_super_sectorsize(disk_super);
2938         stripesize = sectorsize;
2939         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2940         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2941
2942         /* Cache block sizes */
2943         fs_info->nodesize = nodesize;
2944         fs_info->sectorsize = sectorsize;
2945         fs_info->stripesize = stripesize;
2946
2947         /*
2948          * mixed block groups end up with duplicate but slightly offset
2949          * extent buffers for the same range.  It leads to corruptions
2950          */
2951         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2952             (sectorsize != nodesize)) {
2953                 btrfs_err(fs_info,
2954 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2955                         nodesize, sectorsize);
2956                 goto fail_alloc;
2957         }
2958
2959         /*
2960          * Needn't use the lock because there is no other task which will
2961          * update the flag.
2962          */
2963         btrfs_set_super_incompat_flags(disk_super, features);
2964
2965         features = btrfs_super_compat_ro_flags(disk_super) &
2966                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2967         if (!sb_rdonly(sb) && features) {
2968                 btrfs_err(fs_info,
2969         "cannot mount read-write because of unsupported optional features (%llx)",
2970                        features);
2971                 err = -EINVAL;
2972                 goto fail_alloc;
2973         }
2974
2975         ret = btrfs_init_workqueues(fs_info, fs_devices);
2976         if (ret) {
2977                 err = ret;
2978                 goto fail_sb_buffer;
2979         }
2980
2981         sb->s_bdi->congested_fn = btrfs_congested_fn;
2982         sb->s_bdi->congested_data = fs_info;
2983         sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
2984         sb->s_bdi->ra_pages = VM_MAX_READAHEAD * SZ_1K / PAGE_SIZE;
2985         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
2986         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
2987
2988         sb->s_blocksize = sectorsize;
2989         sb->s_blocksize_bits = blksize_bits(sectorsize);
2990         memcpy(&sb->s_uuid, fs_info->fsid, BTRFS_FSID_SIZE);
2991
2992         mutex_lock(&fs_info->chunk_mutex);
2993         ret = btrfs_read_sys_array(fs_info);
2994         mutex_unlock(&fs_info->chunk_mutex);
2995         if (ret) {
2996                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2997                 goto fail_sb_buffer;
2998         }
2999
3000         generation = btrfs_super_chunk_root_generation(disk_super);
3001         level = btrfs_super_chunk_root_level(disk_super);
3002
3003         __setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
3004
3005         chunk_root->node = read_tree_block(fs_info,
3006                                            btrfs_super_chunk_root(disk_super),
3007                                            generation, level, NULL);
3008         if (IS_ERR(chunk_root->node) ||
3009             !extent_buffer_uptodate(chunk_root->node)) {
3010                 btrfs_err(fs_info, "failed to read chunk root");
3011                 if (!IS_ERR(chunk_root->node))
3012                         free_extent_buffer(chunk_root->node);
3013                 chunk_root->node = NULL;
3014                 goto fail_tree_roots;
3015         }
3016         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
3017         chunk_root->commit_root = btrfs_root_node(chunk_root);
3018
3019         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3020            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
3021
3022         ret = btrfs_read_chunk_tree(fs_info);
3023         if (ret) {
3024                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3025                 goto fail_tree_roots;
3026         }
3027
3028         /*
3029          * Keep the devid that is marked to be the target device for the
3030          * device replace procedure
3031          */
3032         btrfs_free_extra_devids(fs_devices, 0);
3033
3034         if (!fs_devices->latest_bdev) {
3035                 btrfs_err(fs_info, "failed to read devices");
3036                 goto fail_tree_roots;
3037         }
3038
3039 retry_root_backup:
3040         generation = btrfs_super_generation(disk_super);
3041         level = btrfs_super_root_level(disk_super);
3042
3043         tree_root->node = read_tree_block(fs_info,
3044                                           btrfs_super_root(disk_super),
3045                                           generation, level, NULL);
3046         if (IS_ERR(tree_root->node) ||
3047             !extent_buffer_uptodate(tree_root->node)) {
3048                 btrfs_warn(fs_info, "failed to read tree root");
3049                 if (!IS_ERR(tree_root->node))
3050                         free_extent_buffer(tree_root->node);
3051                 tree_root->node = NULL;
3052                 goto recovery_tree_root;
3053         }
3054
3055         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
3056         tree_root->commit_root = btrfs_root_node(tree_root);
3057         btrfs_set_root_refs(&tree_root->root_item, 1);
3058
3059         mutex_lock(&tree_root->objectid_mutex);
3060         ret = btrfs_find_highest_objectid(tree_root,
3061                                         &tree_root->highest_objectid);
3062         if (ret) {
3063                 mutex_unlock(&tree_root->objectid_mutex);
3064                 goto recovery_tree_root;
3065         }
3066
3067         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
3068
3069         mutex_unlock(&tree_root->objectid_mutex);
3070
3071         ret = btrfs_read_roots(fs_info);
3072         if (ret)
3073                 goto recovery_tree_root;
3074
3075         fs_info->generation = generation;
3076         fs_info->last_trans_committed = generation;
3077
3078         ret = btrfs_recover_balance(fs_info);
3079         if (ret) {
3080                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3081                 goto fail_block_groups;
3082         }
3083
3084         ret = btrfs_init_dev_stats(fs_info);
3085         if (ret) {
3086                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3087                 goto fail_block_groups;
3088         }
3089
3090         ret = btrfs_init_dev_replace(fs_info);
3091         if (ret) {
3092                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3093                 goto fail_block_groups;
3094         }
3095
3096         btrfs_free_extra_devids(fs_devices, 1);
3097
3098         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
3099         if (ret) {
3100                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3101                                 ret);
3102                 goto fail_block_groups;
3103         }
3104
3105         ret = btrfs_sysfs_add_device(fs_devices);
3106         if (ret) {
3107                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
3108                                 ret);
3109                 goto fail_fsdev_sysfs;
3110         }
3111
3112         ret = btrfs_sysfs_add_mounted(fs_info);
3113         if (ret) {
3114                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3115                 goto fail_fsdev_sysfs;
3116         }
3117
3118         ret = btrfs_init_space_info(fs_info);
3119         if (ret) {
3120                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3121                 goto fail_sysfs;
3122         }
3123
3124         ret = btrfs_read_block_groups(fs_info);
3125         if (ret) {
3126                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3127                 goto fail_sysfs;
3128         }
3129
3130         if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
3131                 btrfs_warn(fs_info,
3132                 "writeable mount is not allowed due to too many missing devices");
3133                 goto fail_sysfs;
3134         }
3135
3136         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3137                                                "btrfs-cleaner");
3138         if (IS_ERR(fs_info->cleaner_kthread))
3139                 goto fail_sysfs;
3140
3141         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3142                                                    tree_root,
3143                                                    "btrfs-transaction");
3144         if (IS_ERR(fs_info->transaction_kthread))
3145                 goto fail_cleaner;
3146
3147         if (!btrfs_test_opt(fs_info, NOSSD) &&
3148             !fs_info->fs_devices->rotating) {
3149                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3150         }
3151
3152         /*
3153          * Mount does not set all options immediately, we can do it now and do
3154          * not have to wait for transaction commit
3155          */
3156         btrfs_apply_pending_changes(fs_info);
3157
3158 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3159         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3160                 ret = btrfsic_mount(fs_info, fs_devices,
3161                                     btrfs_test_opt(fs_info,
3162                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3163                                     1 : 0,
3164                                     fs_info->check_integrity_print_mask);
3165                 if (ret)
3166                         btrfs_warn(fs_info,
3167                                 "failed to initialize integrity check module: %d",
3168                                 ret);
3169         }
3170 #endif
3171         ret = btrfs_read_qgroup_config(fs_info);
3172         if (ret)
3173                 goto fail_trans_kthread;
3174
3175         if (btrfs_build_ref_tree(fs_info))
3176                 btrfs_err(fs_info, "couldn't build ref tree");
3177
3178         /* do not make disk changes in broken FS or nologreplay is given */
3179         if (btrfs_super_log_root(disk_super) != 0 &&
3180             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3181                 ret = btrfs_replay_log(fs_info, fs_devices);
3182                 if (ret) {
3183                         err = ret;
3184                         goto fail_qgroup;
3185                 }
3186         }
3187
3188         ret = btrfs_find_orphan_roots(fs_info);
3189         if (ret)
3190                 goto fail_qgroup;
3191
3192         if (!sb_rdonly(sb)) {
3193                 ret = btrfs_cleanup_fs_roots(fs_info);
3194                 if (ret)
3195                         goto fail_qgroup;
3196
3197                 mutex_lock(&fs_info->cleaner_mutex);
3198                 ret = btrfs_recover_relocation(tree_root);
3199                 mutex_unlock(&fs_info->cleaner_mutex);
3200                 if (ret < 0) {
3201                         btrfs_warn(fs_info, "failed to recover relocation: %d",
3202                                         ret);
3203                         err = -EINVAL;
3204                         goto fail_qgroup;
3205                 }
3206         }
3207
3208         location.objectid = BTRFS_FS_TREE_OBJECTID;
3209         location.type = BTRFS_ROOT_ITEM_KEY;
3210         location.offset = 0;
3211
3212         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3213         if (IS_ERR(fs_info->fs_root)) {
3214                 err = PTR_ERR(fs_info->fs_root);
3215                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3216                 goto fail_qgroup;
3217         }
3218
3219         if (sb_rdonly(sb))
3220                 return 0;
3221
3222         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3223             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3224                 clear_free_space_tree = 1;
3225         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3226                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3227                 btrfs_warn(fs_info, "free space tree is invalid");
3228                 clear_free_space_tree = 1;
3229         }
3230
3231         if (clear_free_space_tree) {
3232                 btrfs_info(fs_info, "clearing free space tree");
3233                 ret = btrfs_clear_free_space_tree(fs_info);
3234                 if (ret) {
3235                         btrfs_warn(fs_info,
3236                                    "failed to clear free space tree: %d", ret);
3237                         close_ctree(fs_info);
3238                         return ret;
3239                 }
3240         }
3241
3242         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3243             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3244                 btrfs_info(fs_info, "creating free space tree");
3245                 ret = btrfs_create_free_space_tree(fs_info);
3246                 if (ret) {
3247                         btrfs_warn(fs_info,
3248                                 "failed to create free space tree: %d", ret);
3249                         close_ctree(fs_info);
3250                         return ret;
3251                 }
3252         }
3253
3254         down_read(&fs_info->cleanup_work_sem);
3255         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3256             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3257                 up_read(&fs_info->cleanup_work_sem);
3258                 close_ctree(fs_info)