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