6a5a3cd128863ec0b502c644b88eeee4bb78caf0
[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->objectid.  This ensures that all special purpose roots
129  * 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->objectid = objectid;
1152         root->last_trans = 0;
1153         root->highest_objectid = 0;
1154         root->nr_delalloc_inodes = 0;
1155         root->nr_ordered_extents = 0;
1156         root->inode_tree = RB_ROOT;
1157         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1158         root->block_rsv = NULL;
1159
1160         INIT_LIST_HEAD(&root->dirty_list);
1161         INIT_LIST_HEAD(&root->root_list);
1162         INIT_LIST_HEAD(&root->delalloc_inodes);
1163         INIT_LIST_HEAD(&root->delalloc_root);
1164         INIT_LIST_HEAD(&root->ordered_extents);
1165         INIT_LIST_HEAD(&root->ordered_root);
1166         INIT_LIST_HEAD(&root->logged_list[0]);
1167         INIT_LIST_HEAD(&root->logged_list[1]);
1168         spin_lock_init(&root->inode_lock);
1169         spin_lock_init(&root->delalloc_lock);
1170         spin_lock_init(&root->ordered_extent_lock);
1171         spin_lock_init(&root->accounting_lock);
1172         spin_lock_init(&root->log_extents_lock[0]);
1173         spin_lock_init(&root->log_extents_lock[1]);
1174         spin_lock_init(&root->qgroup_meta_rsv_lock);
1175         mutex_init(&root->objectid_mutex);
1176         mutex_init(&root->log_mutex);
1177         mutex_init(&root->ordered_extent_mutex);
1178         mutex_init(&root->delalloc_mutex);
1179         init_waitqueue_head(&root->log_writer_wait);
1180         init_waitqueue_head(&root->log_commit_wait[0]);
1181         init_waitqueue_head(&root->log_commit_wait[1]);
1182         INIT_LIST_HEAD(&root->log_ctxs[0]);
1183         INIT_LIST_HEAD(&root->log_ctxs[1]);
1184         atomic_set(&root->log_commit[0], 0);
1185         atomic_set(&root->log_commit[1], 0);
1186         atomic_set(&root->log_writers, 0);
1187         atomic_set(&root->log_batch, 0);
1188         refcount_set(&root->refs, 1);
1189         atomic_set(&root->will_be_snapshotted, 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.read_locks, 0);
2159         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2160         init_waitqueue_head(&fs_info->replace_wait);
2161         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2162 }
2163
2164 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2165 {
2166         spin_lock_init(&fs_info->qgroup_lock);
2167         mutex_init(&fs_info->qgroup_ioctl_lock);
2168         fs_info->qgroup_tree = RB_ROOT;
2169         fs_info->qgroup_op_tree = RB_ROOT;
2170         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2171         fs_info->qgroup_seq = 1;
2172         fs_info->qgroup_ulist = NULL;
2173         fs_info->qgroup_rescan_running = false;
2174         mutex_init(&fs_info->qgroup_rescan_lock);
2175 }
2176
2177 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2178                 struct btrfs_fs_devices *fs_devices)
2179 {
2180         u32 max_active = fs_info->thread_pool_size;
2181         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2182
2183         fs_info->workers =
2184                 btrfs_alloc_workqueue(fs_info, "worker",
2185                                       flags | WQ_HIGHPRI, max_active, 16);
2186
2187         fs_info->delalloc_workers =
2188                 btrfs_alloc_workqueue(fs_info, "delalloc",
2189                                       flags, max_active, 2);
2190
2191         fs_info->flush_workers =
2192                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2193                                       flags, max_active, 0);
2194
2195         fs_info->caching_workers =
2196                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2197
2198         /*
2199          * a higher idle thresh on the submit workers makes it much more
2200          * likely that bios will be send down in a sane order to the
2201          * devices
2202          */
2203         fs_info->submit_workers =
2204                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2205                                       min_t(u64, fs_devices->num_devices,
2206                                             max_active), 64);
2207
2208         fs_info->fixup_workers =
2209                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2210
2211         /*
2212          * endios are largely parallel and should have a very
2213          * low idle thresh
2214          */
2215         fs_info->endio_workers =
2216                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2217         fs_info->endio_meta_workers =
2218                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2219                                       max_active, 4);
2220         fs_info->endio_meta_write_workers =
2221                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2222                                       max_active, 2);
2223         fs_info->endio_raid56_workers =
2224                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2225                                       max_active, 4);
2226         fs_info->endio_repair_workers =
2227                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2228         fs_info->rmw_workers =
2229                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2230         fs_info->endio_write_workers =
2231                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2232                                       max_active, 2);
2233         fs_info->endio_freespace_worker =
2234                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2235                                       max_active, 0);
2236         fs_info->delayed_workers =
2237                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2238                                       max_active, 0);
2239         fs_info->readahead_workers =
2240                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2241                                       max_active, 2);
2242         fs_info->qgroup_rescan_workers =
2243                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2244         fs_info->extent_workers =
2245                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2246                                       min_t(u64, fs_devices->num_devices,
2247                                             max_active), 8);
2248
2249         if (!(fs_info->workers && fs_info->delalloc_workers &&
2250               fs_info->submit_workers && fs_info->flush_workers &&
2251               fs_info->endio_workers && fs_info->endio_meta_workers &&
2252               fs_info->endio_meta_write_workers &&
2253               fs_info->endio_repair_workers &&
2254               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2255               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2256               fs_info->caching_workers && fs_info->readahead_workers &&
2257               fs_info->fixup_workers && fs_info->delayed_workers &&
2258               fs_info->extent_workers &&
2259               fs_info->qgroup_rescan_workers)) {
2260                 return -ENOMEM;
2261         }
2262
2263         return 0;
2264 }
2265
2266 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2267                             struct btrfs_fs_devices *fs_devices)
2268 {
2269         int ret;
2270         struct btrfs_root *log_tree_root;
2271         struct btrfs_super_block *disk_super = fs_info->super_copy;
2272         u64 bytenr = btrfs_super_log_root(disk_super);
2273         int level = btrfs_super_log_root_level(disk_super);
2274
2275         if (fs_devices->rw_devices == 0) {
2276                 btrfs_warn(fs_info, "log replay required on RO media");
2277                 return -EIO;
2278         }
2279
2280         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2281         if (!log_tree_root)
2282                 return -ENOMEM;
2283
2284         __setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2285
2286         log_tree_root->node = read_tree_block(fs_info, bytenr,
2287                                               fs_info->generation + 1,
2288                                               level, NULL);
2289         if (IS_ERR(log_tree_root->node)) {
2290                 btrfs_warn(fs_info, "failed to read log tree");
2291                 ret = PTR_ERR(log_tree_root->node);
2292                 kfree(log_tree_root);
2293                 return ret;
2294         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2295                 btrfs_err(fs_info, "failed to read log tree");
2296                 free_extent_buffer(log_tree_root->node);
2297                 kfree(log_tree_root);
2298                 return -EIO;
2299         }
2300         /* returns with log_tree_root freed on success */
2301         ret = btrfs_recover_log_trees(log_tree_root);
2302         if (ret) {
2303                 btrfs_handle_fs_error(fs_info, ret,
2304                                       "Failed to recover log tree");
2305                 free_extent_buffer(log_tree_root->node);
2306                 kfree(log_tree_root);
2307                 return ret;
2308         }
2309
2310         if (sb_rdonly(fs_info->sb)) {
2311                 ret = btrfs_commit_super(fs_info);
2312                 if (ret)
2313                         return ret;
2314         }
2315
2316         return 0;
2317 }
2318
2319 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2320 {
2321         struct btrfs_root *tree_root = fs_info->tree_root;
2322         struct btrfs_root *root;
2323         struct btrfs_key location;
2324         int ret;
2325
2326         BUG_ON(!fs_info->tree_root);
2327
2328         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2329         location.type = BTRFS_ROOT_ITEM_KEY;
2330         location.offset = 0;
2331
2332         root = btrfs_read_tree_root(tree_root, &location);
2333         if (IS_ERR(root)) {
2334                 ret = PTR_ERR(root);
2335                 goto out;
2336         }
2337         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2338         fs_info->extent_root = root;
2339
2340         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2341         root = btrfs_read_tree_root(tree_root, &location);
2342         if (IS_ERR(root)) {
2343                 ret = PTR_ERR(root);
2344                 goto out;
2345         }
2346         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2347         fs_info->dev_root = root;
2348         btrfs_init_devices_late(fs_info);
2349
2350         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2351         root = btrfs_read_tree_root(tree_root, &location);
2352         if (IS_ERR(root)) {
2353                 ret = PTR_ERR(root);
2354                 goto out;
2355         }
2356         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2357         fs_info->csum_root = root;
2358
2359         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2360         root = btrfs_read_tree_root(tree_root, &location);
2361         if (!IS_ERR(root)) {
2362                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2363                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2364                 fs_info->quota_root = root;
2365         }
2366
2367         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2368         root = btrfs_read_tree_root(tree_root, &location);
2369         if (IS_ERR(root)) {
2370                 ret = PTR_ERR(root);
2371                 if (ret != -ENOENT)
2372                         goto out;
2373         } else {
2374                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2375                 fs_info->uuid_root = root;
2376         }
2377
2378         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2379                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2380                 root = btrfs_read_tree_root(tree_root, &location);
2381                 if (IS_ERR(root)) {
2382                         ret = PTR_ERR(root);
2383                         goto out;
2384                 }
2385                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2386                 fs_info->free_space_root = root;
2387         }
2388
2389         return 0;
2390 out:
2391         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2392                    location.objectid, ret);
2393         return ret;
2394 }
2395
2396 /*
2397  * Real super block validation
2398  * NOTE: super csum type and incompat features will not be checked here.
2399  *
2400  * @sb:         super block to check
2401  * @mirror_num: the super block number to check its bytenr:
2402  *              0       the primary (1st) sb
2403  *              1, 2    2nd and 3rd backup copy
2404  *             -1       skip bytenr check
2405  */
2406 static int validate_super(struct btrfs_fs_info *fs_info,
2407                             struct btrfs_super_block *sb, int mirror_num)
2408 {
2409         u64 nodesize = btrfs_super_nodesize(sb);
2410         u64 sectorsize = btrfs_super_sectorsize(sb);
2411         int ret = 0;
2412
2413         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2414                 btrfs_err(fs_info, "no valid FS found");
2415                 ret = -EINVAL;
2416         }
2417         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2418                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2419                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2420                 ret = -EINVAL;
2421         }
2422         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2423                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2424                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2425                 ret = -EINVAL;
2426         }
2427         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2428                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2429                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2430                 ret = -EINVAL;
2431         }
2432         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2433                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2434                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2435                 ret = -EINVAL;
2436         }
2437
2438         /*
2439          * Check sectorsize and nodesize first, other check will need it.
2440          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2441          */
2442         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2443             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2444                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2445                 ret = -EINVAL;
2446         }
2447         /* Only PAGE SIZE is supported yet */
2448         if (sectorsize != PAGE_SIZE) {
2449                 btrfs_err(fs_info,
2450                         "sectorsize %llu not supported yet, only support %lu",
2451                         sectorsize, PAGE_SIZE);
2452                 ret = -EINVAL;
2453         }
2454         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2455             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2456                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2457                 ret = -EINVAL;
2458         }
2459         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2460                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2461                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2462                 ret = -EINVAL;
2463         }
2464
2465         /* Root alignment check */
2466         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2467                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2468                            btrfs_super_root(sb));
2469                 ret = -EINVAL;
2470         }
2471         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2472                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2473                            btrfs_super_chunk_root(sb));
2474                 ret = -EINVAL;
2475         }
2476         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2477                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2478                            btrfs_super_log_root(sb));
2479                 ret = -EINVAL;
2480         }
2481
2482         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) {
2483                 btrfs_err(fs_info,
2484                            "dev_item UUID does not match fsid: %pU != %pU",
2485                            fs_info->fsid, sb->dev_item.fsid);
2486                 ret = -EINVAL;
2487         }
2488
2489         /*
2490          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2491          * done later
2492          */
2493         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2494                 btrfs_err(fs_info, "bytes_used is too small %llu",
2495                           btrfs_super_bytes_used(sb));
2496                 ret = -EINVAL;
2497         }
2498         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2499                 btrfs_err(fs_info, "invalid stripesize %u",
2500                           btrfs_super_stripesize(sb));
2501                 ret = -EINVAL;
2502         }
2503         if (btrfs_super_num_devices(sb) > (1UL << 31))
2504                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2505                            btrfs_super_num_devices(sb));
2506         if (btrfs_super_num_devices(sb) == 0) {
2507                 btrfs_err(fs_info, "number of devices is 0");
2508                 ret = -EINVAL;
2509         }
2510
2511         if (mirror_num >= 0 &&
2512             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2513                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2514                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2515                 ret = -EINVAL;
2516         }
2517
2518         /*
2519          * Obvious sys_chunk_array corruptions, it must hold at least one key
2520          * and one chunk
2521          */
2522         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2523                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2524                           btrfs_super_sys_array_size(sb),
2525                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2526                 ret = -EINVAL;
2527         }
2528         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2529                         + sizeof(struct btrfs_chunk)) {
2530                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2531                           btrfs_super_sys_array_size(sb),
2532                           sizeof(struct btrfs_disk_key)
2533                           + sizeof(struct btrfs_chunk));
2534                 ret = -EINVAL;
2535         }
2536
2537         /*
2538          * The generation is a global counter, we'll trust it more than the others
2539          * but it's still possible that it's the one that's wrong.
2540          */
2541         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2542                 btrfs_warn(fs_info,
2543                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2544                         btrfs_super_generation(sb),
2545                         btrfs_super_chunk_root_generation(sb));
2546         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2547             && btrfs_super_cache_generation(sb) != (u64)-1)
2548                 btrfs_warn(fs_info,
2549                         "suspicious: generation < cache_generation: %llu < %llu",
2550                         btrfs_super_generation(sb),
2551                         btrfs_super_cache_generation(sb));
2552
2553         return ret;
2554 }
2555
2556 /*
2557  * Validation of super block at mount time.
2558  * Some checks already done early at mount time, like csum type and incompat
2559  * flags will be skipped.
2560  */
2561 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2562 {
2563         return validate_super(fs_info, fs_info->super_copy, 0);
2564 }
2565
2566 /*
2567  * Validation of super block at write time.
2568  * Some checks like bytenr check will be skipped as their values will be
2569  * overwritten soon.
2570  * Extra checks like csum type and incompat flags will be done here.
2571  */
2572 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2573                                       struct btrfs_super_block *sb)
2574 {
2575         int ret;
2576
2577         ret = validate_super(fs_info, sb, -1);
2578         if (ret < 0)
2579                 goto out;
2580         if (btrfs_super_csum_type(sb) != BTRFS_CSUM_TYPE_CRC32) {
2581                 ret = -EUCLEAN;
2582                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2583                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2584                 goto out;
2585         }
2586         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2587                 ret = -EUCLEAN;
2588                 btrfs_err(fs_info,
2589                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2590                           btrfs_super_incompat_flags(sb),
2591                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2592                 goto out;
2593         }
2594 out:
2595         if (ret < 0)
2596                 btrfs_err(fs_info,
2597                 "super block corruption detected before writing it to disk");
2598         return ret;
2599 }
2600
2601 int open_ctree(struct super_block *sb,
2602                struct btrfs_fs_devices *fs_devices,
2603                char *options)
2604 {
2605         u32 sectorsize;
2606         u32 nodesize;
2607         u32 stripesize;
2608         u64 generation;
2609         u64 features;
2610         struct btrfs_key location;
2611         struct buffer_head *bh;
2612         struct btrfs_super_block *disk_super;
2613         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2614         struct btrfs_root *tree_root;
2615         struct btrfs_root *chunk_root;
2616         int ret;
2617         int err = -EINVAL;
2618         int num_backups_tried = 0;
2619         int backup_index = 0;
2620         int clear_free_space_tree = 0;
2621         int level;
2622
2623         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2624         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2625         if (!tree_root || !chunk_root) {
2626                 err = -ENOMEM;
2627                 goto fail;
2628         }
2629
2630         ret = init_srcu_struct(&fs_info->subvol_srcu);
2631         if (ret) {
2632                 err = ret;
2633                 goto fail;
2634         }
2635
2636         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2637         if (ret) {
2638                 err = ret;
2639                 goto fail_srcu;
2640         }
2641         fs_info->dirty_metadata_batch = PAGE_SIZE *
2642                                         (1 + ilog2(nr_cpu_ids));
2643
2644         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2645         if (ret) {
2646                 err = ret;
2647                 goto fail_dirty_metadata_bytes;
2648         }
2649
2650         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2651         if (ret) {
2652                 err = ret;
2653                 goto fail_delalloc_bytes;
2654         }
2655
2656         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2657         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2658         INIT_LIST_HEAD(&fs_info->trans_list);
2659         INIT_LIST_HEAD(&fs_info->dead_roots);
2660         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2661         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2662         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2663         INIT_LIST_HEAD(&fs_info->pending_raid_kobjs);
2664         spin_lock_init(&fs_info->pending_raid_kobjs_lock);
2665         spin_lock_init(&fs_info->delalloc_root_lock);
2666         spin_lock_init(&fs_info->trans_lock);
2667         spin_lock_init(&fs_info->fs_roots_radix_lock);
2668         spin_lock_init(&fs_info->delayed_iput_lock);
2669         spin_lock_init(&fs_info->defrag_inodes_lock);
2670         spin_lock_init(&fs_info->tree_mod_seq_lock);
2671         spin_lock_init(&fs_info->super_lock);
2672         spin_lock_init(&fs_info->qgroup_op_lock);
2673         spin_lock_init(&fs_info->buffer_lock);
2674         spin_lock_init(&fs_info->unused_bgs_lock);
2675         rwlock_init(&fs_info->tree_mod_log_lock);
2676         mutex_init(&fs_info->unused_bg_unpin_mutex);
2677         mutex_init(&fs_info->delete_unused_bgs_mutex);
2678         mutex_init(&fs_info->reloc_mutex);
2679         mutex_init(&fs_info->delalloc_root_mutex);
2680         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2681         seqlock_init(&fs_info->profiles_lock);
2682
2683         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2684         INIT_LIST_HEAD(&fs_info->space_info);
2685         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2686         INIT_LIST_HEAD(&fs_info->unused_bgs);
2687         btrfs_mapping_init(&fs_info->mapping_tree);
2688         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2689                              BTRFS_BLOCK_RSV_GLOBAL);
2690         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2691         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2692         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2693         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2694                              BTRFS_BLOCK_RSV_DELOPS);
2695         atomic_set(&fs_info->async_delalloc_pages, 0);
2696         atomic_set(&fs_info->defrag_running, 0);
2697         atomic_set(&fs_info->qgroup_op_seq, 0);
2698         atomic_set(&fs_info->reada_works_cnt, 0);
2699         atomic64_set(&fs_info->tree_mod_seq, 0);
2700         fs_info->sb = sb;
2701         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2702         fs_info->metadata_ratio = 0;
2703         fs_info->defrag_inodes = RB_ROOT;
2704         atomic64_set(&fs_info->free_chunk_space, 0);
2705         fs_info->tree_mod_log = RB_ROOT;
2706         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2707         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2708         /* readahead state */
2709         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2710         spin_lock_init(&fs_info->reada_lock);
2711         btrfs_init_ref_verify(fs_info);
2712
2713         fs_info->thread_pool_size = min_t(unsigned long,
2714                                           num_online_cpus() + 2, 8);
2715
2716         INIT_LIST_HEAD(&fs_info->ordered_roots);
2717         spin_lock_init(&fs_info->ordered_root_lock);
2718
2719         fs_info->btree_inode = new_inode(sb);
2720         if (!fs_info->btree_inode) {
2721                 err = -ENOMEM;
2722                 goto fail_bio_counter;
2723         }
2724         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2725
2726         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2727                                         GFP_KERNEL);
2728         if (!fs_info->delayed_root) {
2729                 err = -ENOMEM;
2730                 goto fail_iput;
2731         }
2732         btrfs_init_delayed_root(fs_info->delayed_root);
2733
2734         btrfs_init_scrub(fs_info);
2735 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2736         fs_info->check_integrity_print_mask = 0;
2737 #endif
2738         btrfs_init_balance(fs_info);
2739         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2740
2741         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2742         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
2743
2744         btrfs_init_btree_inode(fs_info);
2745
2746         spin_lock_init(&fs_info->block_group_cache_lock);
2747         fs_info->block_group_cache_tree = RB_ROOT;
2748         fs_info->first_logical_byte = (u64)-1;
2749
2750         extent_io_tree_init(&fs_info->freed_extents[0], NULL);
2751         extent_io_tree_init(&fs_info->freed_extents[1], NULL);
2752         fs_info->pinned_extents = &fs_info->freed_extents[0];
2753         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2754
2755         mutex_init(&fs_info->ordered_operations_mutex);
2756         mutex_init(&fs_info->tree_log_mutex);
2757         mutex_init(&fs_info->chunk_mutex);
2758         mutex_init(&fs_info->transaction_kthread_mutex);
2759         mutex_init(&fs_info->cleaner_mutex);
2760         mutex_init(&fs_info->ro_block_group_mutex);
2761         init_rwsem(&fs_info->commit_root_sem);
2762         init_rwsem(&fs_info->cleanup_work_sem);
2763         init_rwsem(&fs_info->subvol_sem);
2764         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2765
2766         btrfs_init_dev_replace_locks(fs_info);
2767         btrfs_init_qgroup(fs_info);
2768
2769         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2770         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2771
2772         init_waitqueue_head(&fs_info->transaction_throttle);
2773         init_waitqueue_head(&fs_info->transaction_wait);
2774         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2775         init_waitqueue_head(&fs_info->async_submit_wait);
2776
2777         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2778
2779         /* Usable values until the real ones are cached from the superblock */
2780         fs_info->nodesize = 4096;
2781         fs_info->sectorsize = 4096;
2782         fs_info->stripesize = 4096;
2783
2784         ret = btrfs_alloc_stripe_hash_table(fs_info);
2785         if (ret) {
2786                 err = ret;
2787                 goto fail_alloc;
2788         }
2789
2790         __setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
2791
2792         invalidate_bdev(fs_devices->latest_bdev);
2793
2794         /*
2795          * Read super block and check the signature bytes only
2796          */
2797         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2798         if (IS_ERR(bh)) {
2799                 err = PTR_ERR(bh);
2800                 goto fail_alloc;
2801         }
2802
2803         /*
2804          * We want to check superblock checksum, the type is stored inside.
2805          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2806          */
2807         if (btrfs_check_super_csum(fs_info, bh->b_data)) {
2808                 btrfs_err(fs_info, "superblock checksum mismatch");
2809                 err = -EINVAL;
2810                 brelse(bh);
2811                 goto fail_alloc;
2812         }
2813
2814         /*
2815          * super_copy is zeroed at allocation time and we never touch the
2816          * following bytes up to INFO_SIZE, the checksum is calculated from
2817          * the whole block of INFO_SIZE
2818          */
2819         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2820         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2821                sizeof(*fs_info->super_for_commit));
2822         brelse(bh);
2823
2824         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2825
2826         ret = btrfs_validate_mount_super(fs_info);
2827         if (ret) {
2828                 btrfs_err(fs_info, "superblock contains fatal errors");
2829                 err = -EINVAL;
2830                 goto fail_alloc;
2831         }
2832
2833         disk_super = fs_info->super_copy;
2834         if (!btrfs_super_root(disk_super))
2835                 goto fail_alloc;
2836
2837         /* check FS state, whether FS is broken. */
2838         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2839                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2840
2841         /*
2842          * run through our array of backup supers and setup
2843          * our ring pointer to the oldest one
2844          */
2845         generation = btrfs_super_generation(disk_super);
2846         find_oldest_super_backup(fs_info, generation);
2847
2848         /*
2849          * In the long term, we'll store the compression type in the super
2850          * block, and it'll be used for per file compression control.
2851          */
2852         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2853
2854         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
2855         if (ret) {
2856                 err = ret;
2857                 goto fail_alloc;
2858         }
2859
2860         features = btrfs_super_incompat_flags(disk_super) &
2861                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2862         if (features) {
2863                 btrfs_err(fs_info,
2864                     "cannot mount because of unsupported optional features (%llx)",
2865                     features);
2866                 err = -EINVAL;
2867                 goto fail_alloc;
2868         }
2869
2870         features = btrfs_super_incompat_flags(disk_super);
2871         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2872         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
2873                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2874         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
2875                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
2876
2877         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2878                 btrfs_info(fs_info, "has skinny extents");
2879
2880         /*
2881          * flag our filesystem as having big metadata blocks if
2882          * they are bigger than the page size
2883          */
2884         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2885                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2886                         btrfs_info(fs_info,
2887                                 "flagging fs with big metadata feature");
2888                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2889         }
2890
2891         nodesize = btrfs_super_nodesize(disk_super);
2892         sectorsize = btrfs_super_sectorsize(disk_super);
2893         stripesize = sectorsize;
2894         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2895         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2896
2897         /* Cache block sizes */
2898         fs_info->nodesize = nodesize;
2899         fs_info->sectorsize = sectorsize;
2900         fs_info->stripesize = stripesize;
2901
2902         /*
2903          * mixed block groups end up with duplicate but slightly offset
2904          * extent buffers for the same range.  It leads to corruptions
2905          */
2906         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2907             (sectorsize != nodesize)) {
2908                 btrfs_err(fs_info,
2909 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2910                         nodesize, sectorsize);
2911                 goto fail_alloc;
2912         }
2913
2914         /*
2915          * Needn't use the lock because there is no other task which will
2916          * update the flag.
2917          */
2918         btrfs_set_super_incompat_flags(disk_super, features);
2919
2920         features = btrfs_super_compat_ro_flags(disk_super) &
2921                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2922         if (!sb_rdonly(sb) && features) {
2923                 btrfs_err(fs_info,
2924         "cannot mount read-write because of unsupported optional features (%llx)",
2925                        features);
2926                 err = -EINVAL;
2927                 goto fail_alloc;
2928         }
2929
2930         ret = btrfs_init_workqueues(fs_info, fs_devices);
2931         if (ret) {
2932                 err = ret;
2933                 goto fail_sb_buffer;
2934         }
2935
2936         sb->s_bdi->congested_fn = btrfs_congested_fn;
2937         sb->s_bdi->congested_data = fs_info;
2938         sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
2939         sb->s_bdi->ra_pages = VM_MAX_READAHEAD * SZ_1K / PAGE_SIZE;
2940         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
2941         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
2942
2943         sb->s_blocksize = sectorsize;
2944         sb->s_blocksize_bits = blksize_bits(sectorsize);
2945         memcpy(&sb->s_uuid, fs_info->fsid, BTRFS_FSID_SIZE);
2946
2947         mutex_lock(&fs_info->chunk_mutex);
2948         ret = btrfs_read_sys_array(fs_info);
2949         mutex_unlock(&fs_info->chunk_mutex);
2950         if (ret) {
2951                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2952                 goto fail_sb_buffer;
2953         }
2954
2955         generation = btrfs_super_chunk_root_generation(disk_super);
2956         level = btrfs_super_chunk_root_level(disk_super);
2957
2958         __setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2959
2960         chunk_root->node = read_tree_block(fs_info,
2961                                            btrfs_super_chunk_root(disk_super),
2962                                            generation, level, NULL);
2963         if (IS_ERR(chunk_root->node) ||
2964             !extent_buffer_uptodate(chunk_root->node)) {
2965                 btrfs_err(fs_info, "failed to read chunk root");
2966                 if (!IS_ERR(chunk_root->node))
2967                         free_extent_buffer(chunk_root->node);
2968                 chunk_root->node = NULL;
2969                 goto fail_tree_roots;
2970         }
2971         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2972         chunk_root->commit_root = btrfs_root_node(chunk_root);
2973
2974         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2975            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2976
2977         ret = btrfs_read_chunk_tree(fs_info);
2978         if (ret) {
2979                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
2980                 goto fail_tree_roots;
2981         }
2982
2983         /*
2984          * Keep the devid that is marked to be the target device for the
2985          * device replace procedure
2986          */
2987         btrfs_free_extra_devids(fs_devices, 0);
2988
2989         if (!fs_devices->latest_bdev) {
2990                 btrfs_err(fs_info, "failed to read devices");
2991                 goto fail_tree_roots;
2992         }
2993
2994 retry_root_backup:
2995         generation = btrfs_super_generation(disk_super);
2996         level = btrfs_super_root_level(disk_super);
2997
2998         tree_root->node = read_tree_block(fs_info,
2999                                           btrfs_super_root(disk_super),
3000                                           generation, level, NULL);
3001         if (IS_ERR(tree_root->node) ||
3002             !extent_buffer_uptodate(tree_root->node)) {
3003                 btrfs_warn(fs_info, "failed to read tree root");
3004                 if (!IS_ERR(tree_root->node))
3005                         free_extent_buffer(tree_root->node);
3006                 tree_root->node = NULL;
3007                 goto recovery_tree_root;
3008         }
3009
3010         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
3011         tree_root->commit_root = btrfs_root_node(tree_root);
3012         btrfs_set_root_refs(&tree_root->root_item, 1);
3013
3014         mutex_lock(&tree_root->objectid_mutex);
3015         ret = btrfs_find_highest_objectid(tree_root,
3016                                         &tree_root->highest_objectid);
3017         if (ret) {
3018                 mutex_unlock(&tree_root->objectid_mutex);
3019                 goto recovery_tree_root;
3020         }
3021
3022         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
3023
3024         mutex_unlock(&tree_root->objectid_mutex);
3025
3026         ret = btrfs_read_roots(fs_info);
3027         if (ret)
3028                 goto recovery_tree_root;
3029
3030         fs_info->generation = generation;
3031         fs_info->last_trans_committed = generation;
3032
3033         ret = btrfs_recover_balance(fs_info);
3034         if (ret) {
3035                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3036                 goto fail_block_groups;
3037         }
3038
3039         ret = btrfs_init_dev_stats(fs_info);
3040         if (ret) {
3041                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3042                 goto fail_block_groups;
3043         }
3044
3045         ret = btrfs_init_dev_replace(fs_info);
3046         if (ret) {
3047                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3048                 goto fail_block_groups;
3049         }
3050
3051         btrfs_free_extra_devids(fs_devices, 1);
3052
3053         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
3054         if (ret) {
3055                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3056                                 ret);
3057                 goto fail_block_groups;
3058         }
3059
3060         ret = btrfs_sysfs_add_device(fs_devices);
3061         if (ret) {
3062                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
3063                                 ret);
3064                 goto fail_fsdev_sysfs;
3065         }
3066
3067         ret = btrfs_sysfs_add_mounted(fs_info);
3068         if (ret) {
3069                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3070                 goto fail_fsdev_sysfs;
3071         }
3072
3073         ret = btrfs_init_space_info(fs_info);
3074         if (ret) {
3075                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3076                 goto fail_sysfs;
3077         }
3078
3079         ret = btrfs_read_block_groups(fs_info);
3080         if (ret) {
3081                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3082                 goto fail_sysfs;
3083         }
3084
3085         if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
3086                 btrfs_warn(fs_info,
3087                 "writeable mount is not allowed due to too many missing devices");
3088                 goto fail_sysfs;
3089         }
3090
3091         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3092                                                "btrfs-cleaner");
3093         if (IS_ERR(fs_info->cleaner_kthread))
3094                 goto fail_sysfs;
3095
3096         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3097                                                    tree_root,
3098                                                    "btrfs-transaction");
3099         if (IS_ERR(fs_info->transaction_kthread))
3100                 goto fail_cleaner;
3101
3102         if (!btrfs_test_opt(fs_info, NOSSD) &&
3103             !fs_info->fs_devices->rotating) {
3104                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3105         }
3106
3107         /*
3108          * Mount does not set all options immediately, we can do it now and do
3109          * not have to wait for transaction commit
3110          */
3111         btrfs_apply_pending_changes(fs_info);
3112
3113 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3114         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3115                 ret = btrfsic_mount(fs_info, fs_devices,
3116                                     btrfs_test_opt(fs_info,
3117                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3118                                     1 : 0,
3119                                     fs_info->check_integrity_print_mask);
3120                 if (ret)
3121                         btrfs_warn(fs_info,
3122                                 "failed to initialize integrity check module: %d",
3123                                 ret);
3124         }
3125 #endif
3126         ret = btrfs_read_qgroup_config(fs_info);
3127         if (ret)
3128                 goto fail_trans_kthread;
3129
3130         if (btrfs_build_ref_tree(fs_info))
3131                 btrfs_err(fs_info, "couldn't build ref tree");
3132
3133         /* do not make disk changes in broken FS or nologreplay is given */
3134         if (btrfs_super_log_root(disk_super) != 0 &&
3135             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3136                 ret = btrfs_replay_log(fs_info, fs_devices);
3137                 if (ret) {
3138                         err = ret;
3139                         goto fail_qgroup;
3140                 }
3141         }
3142
3143         ret = btrfs_find_orphan_roots(fs_info);
3144         if (ret)
3145                 goto fail_qgroup;
3146
3147         if (!sb_rdonly(sb)) {
3148                 ret = btrfs_cleanup_fs_roots(fs_info);
3149                 if (ret)
3150                         goto fail_qgroup;
3151
3152                 mutex_lock(&fs_info->cleaner_mutex);
3153                 ret = btrfs_recover_relocation(tree_root);
3154                 mutex_unlock(&fs_info->cleaner_mutex);
3155                 if (ret < 0) {
3156                         btrfs_warn(fs_info, "failed to recover relocation: %d",
3157                                         ret);
3158                         err = -EINVAL;
3159                         goto fail_qgroup;
3160                 }
3161         }
3162
3163         location.objectid = BTRFS_FS_TREE_OBJECTID;
3164         location.type = BTRFS_ROOT_ITEM_KEY;
3165         location.offset = 0;
3166
3167         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3168         if (IS_ERR(fs_info->fs_root)) {
3169                 err = PTR_ERR(fs_info->fs_root);
3170                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3171                 goto fail_qgroup;
3172         }
3173
3174         if (sb_rdonly(sb))
3175                 return 0;
3176
3177         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3178             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3179                 clear_free_space_tree = 1;
3180         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3181                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3182                 btrfs_warn(fs_info, "free space tree is invalid");
3183                 clear_free_space_tree = 1;
3184         }
3185
3186         if (clear_free_space_tree) {
3187                 btrfs_info(fs_info, "clearing free space tree");
3188                 ret = btrfs_clear_free_space_tree(fs_info);
3189                 if (ret) {
3190                         btrfs_warn(fs_info,
3191                                    "failed to clear free space tree: %d", ret);
3192                         close_ctree(fs_info);
3193                         return ret;
3194                 }
3195         }
3196
3197         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3198             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3199                 btrfs_info(fs_info, "creating free space tree");
3200                 ret = btrfs_create_free_space_tree(fs_info);
3201                 if (ret) {
3202                         btrfs_warn(fs_info,
3203                                 "failed to create free space tree: %d", ret);
3204                         close_ctree(fs_info);
3205                         return ret;
3206                 }
3207         }
3208
3209         down_read(&fs_info->cleanup_work_sem);
3210         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3211             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3212                 up_read(&fs_info->cleanup_work_sem);
3213                 close_ctree(fs_info);
3214                 return ret;
3215         }
3216         up_read(&fs_info->cleanup_work_sem);
3217
3218         ret = btrfs_resume_balance_async(fs_info);
3219         if (ret) {
3220                 btrfs_warn(fs_info, "failed to resume balance: %d", ret);
3221                 close_ctree(fs_info);
3222                 return ret;
3223         }
3224
3225         ret = btrfs_resume_dev_replace_async(fs_info);
3226         if (ret) {
3227                 btrfs_warn(fs_info, "failed to resume device replace: %d", ret);
3228                 close_ctree(fs_info);
3229                 return ret;
3230         }
3231
3232         btrfs_qgroup_rescan_resume(fs_info);
3233
3234         if (!fs_info->uuid_root) {
3235                 btrfs_info(fs_info, "creating UUID tree");
3236                 ret = btrfs_create_uuid_tree(fs_info);
3237                 if (ret) {
3238                         btrfs_warn(fs_info,
3239                                 "failed to create the UUID tree: %d", ret);
3240                         close_ctree(fs_info);
3241                         return ret;
3242                 }
3243         } else if (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3244                    fs_info->generation !=
3245                                 btrfs_super_uuid_tree_generation(disk_super)) {
3246                 btrfs_info(fs_info, "checking UUID tree");
3247                 ret = btrfs_check_uuid_tree(fs_info);
3248                 if (ret) {
3249                         btrfs_warn(fs_info,
3250                                 "failed to check the UUID tree: %d", ret);
3251                         close_ctree(fs_info);
3252                         return ret;
3253                 }
3254         } else {
3255                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3256         }
3257         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3258
3259         /*
3260          * backuproot only affect mount behavior, and if open_ctree succeeded,
3261          * no need to keep the flag
3262          */
3263         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3264
3265         return 0;
3266
3267 fail_qgroup:
3268         btrfs_free_qgroup_config(fs_info);
3269 fail_trans_kthread:
3270         kthread_stop(fs_info->transaction_kthread);
3271         btrfs_cleanup_transaction(fs_info);
3272         btrfs_free_fs_roots(fs_info);
3273 fail_cleaner:
3274         kthread_stop(fs_info->cleaner_kthread);
3275
3276         /*
3277          * make sure we're done with the btree inode before we stop our
3278          * kthreads
3279          */
3280         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3281
3282 fail_sysfs:
3283         btrfs_sysfs_remove_mounted(fs_info);
3284
3285 fail_fsdev_sysfs:
3286         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3287
3288 fail_block_groups:
3289         btrfs_put_block_group_cache(fs_info);
3290
3291 fail_tree_roots:
3292         free_root_pointers(fs_info, 1);
3293         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3294
3295 fail_sb_buffer:
3296         btrfs_stop_all_workers(fs_info);
3297         btrfs_free_block_groups(fs_info);
3298 fail_alloc:
3299 fail_iput:
3300         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3301
3302         iput(fs_info->btree_inode);
3303 fail_bio_counter:
3304         percpu_counter_destroy(&fs_info->bio_counter);
3305 fail_delalloc_bytes:
3306         percpu_counter_destroy(&fs_info->delalloc_bytes);
3307 fail_dirty_metadata_bytes:
3308         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3309 fail_srcu:
3310         cleanup_srcu_struct(&fs_info->subvol_srcu);
3311 fail:
3312         btrfs_free_stripe_hash_table(fs_info);
3313         btrfs_close_devices(fs_info->fs_devices);
3314         return err;
3315
3316 recovery_tree_root:
3317         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
3318                 goto fail_tree_roots;
3319
3320         free_root_pointers(fs_info, 0);
3321
3322         /* don't use the log in recovery mode, it won't be valid */
3323         btrfs_set_super_log_root(disk_super, 0);
3324
3325         /* we can't trust the free space cache either */
3326         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3327
3328         ret = next_root_backup(fs_info, fs_info->super_copy,
3329                                &num_backups_tried, &backup_index);
3330         if (ret == -1)
3331                 goto fail_block_groups;
3332         goto retry_root_backup;
3333 }
3334 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3335
3336 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3337 {
3338         if (uptodate) {
3339                 set_buffer_uptodate(bh);
3340         } else {
3341                 struct btrfs_device *device = (struct btrfs_device *)
3342                         bh->b_private;
3343
3344                 btrfs_warn_rl_in_rcu(device->fs_info,
3345                                 "lost page write due to IO error on %s",
3346                                           rcu_str_deref(device->name));
3347                 /* note, we don't set_buffer_write_io_error because we have
3348                  * our own ways of dealing with the IO errors
3349                  */
3350                 clear_buffer_uptodate(bh);
3351                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3352         }
3353         unlock_buffer(bh);
3354         put_bh(bh);
3355 }
3356
3357 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
3358                         struct buffer_head **bh_ret)
3359 {
3360         struct buffer_head *bh;
3361         struct btrfs_super_block *super;
3362         u64 bytenr;
3363
3364         bytenr = btrfs_sb_offset(copy_num);
3365         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3366                 return -EINVAL;
3367
3368         bh = __bread(bdev, bytenr / BTRFS_BDEV_BLOCKSIZE, BTRFS_SUPER_INFO_SIZE);
3369         /*
3370          * If we fail to read from the underlying devices, as of now
3371          * the best option we have is to mark it EIO.
3372          */
3373         if (!bh)
3374                 return -EIO;
3375
3376         super = (struct btrfs_super_block *)bh->b_data;
3377         if (btrfs_super_bytenr(super) != bytenr ||
3378                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3379                 brelse(bh);
3380                 return -EINVAL;
3381         }
3382
3383         *bh_ret = bh;
3384         return 0;
3385 }
3386
3387
3388 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3389 {
3390         struct buffer_head *bh;
3391         struct buffer_head *latest = NULL;
3392         struct btrfs_super_block *super;
3393         int i;
3394         u64 transid = 0;
3395         int ret = -EINVAL;
3396
3397         /* we would like to check all the supers, but that would make
3398          * a btrfs mount succeed after a mkfs from a different FS.
3399          * So, we need to add a special mount option to scan for
3400          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3401          */
3402         for (i = 0; i < 1; i++) {
3403                 ret = btrfs_read_dev_one_super(bdev, i, &bh);
3404                 if (ret)
3405                         continue;
3406
3407                 super = (struct btrfs_super_block *)bh->b_data;
3408
3409                 if (!latest || btrfs_super_generation(super) > transid) {
3410                         brelse(latest);
3411                         latest = bh;
3412                         transid = btrfs_super_generation(super);
3413                 } else {
3414                         brelse(bh);
3415                 }
3416         }
3417
3418         if (!latest)
3419                 return ERR_PTR(ret);
3420
3421         return latest;
3422 }
3423
3424 /*
3425  * Write superblock @sb to the @device. Do not wait for completion, all the
3426  * buffer heads we write are pinned.
3427  *
3428  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3429  * the expected device size at commit time. Note that max_mirrors must be
3430  * same for write and wait phases.
3431  *
3432  * Return number of errors when buffer head is not found or submission fails.
3433  */
3434 static int write_dev_supers(struct btrfs_device *device,
3435                             struct btrfs_super_block *sb, int max_mirrors)
3436 {
3437         struct buffer_head *bh;
3438         int i;
3439         int ret;
3440         int errors = 0;
3441         u32 crc;
3442         u64 bytenr;
3443         int op_flags;
3444
3445         if (max_mirrors == 0)
3446                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3447
3448         for (i = 0; i < max_mirrors; i++) {
3449                 bytenr = btrfs_sb_offset(i);
3450                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3451                     device->commit_total_bytes)
3452                         break;
3453
3454                 btrfs_set_super_bytenr(sb, bytenr);
3455
3456                 crc = ~(u32)0;
3457                 crc = btrfs_csum_data((const char *)sb + BTRFS_CSUM_SIZE, crc,
3458                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
3459                 btrfs_csum_final(crc, sb->csum);
3460
3461                 /* One reference for us, and we leave it for the caller */
3462                 bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
3463                               BTRFS_SUPER_INFO_SIZE);
3464                 if (!bh) {
3465                         btrfs_err(device->fs_info,
3466                             "couldn't get super buffer head for bytenr %llu",
3467                             bytenr);
3468                         errors++;
3469                         continue;
3470                 }
3471
3472                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3473
3474                 /* one reference for submit_bh */
3475                 get_bh(bh);
3476
3477                 set_buffer_uptodate(bh);
3478                 lock_buffer(bh);
3479                 bh->b_end_io = btrfs_end_buffer_write_sync;
3480                 bh->b_private = device;
3481
3482                 /*
3483                  * we fua the first super.  The others we allow
3484                  * to go down lazy.
3485                  */
3486                 op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
3487                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3488                         op_flags |= REQ_FUA;
3489                 ret = btrfsic_submit_bh(REQ_OP_WRITE, op_flags, bh);
3490                 if (ret)
3491                         errors++;
3492         }
3493         return errors < i ? 0 : -1;
3494 }
3495
3496 /*
3497  * Wait for write completion of superblocks done by write_dev_supers,
3498  * @max_mirrors same for write and wait phases.
3499  *
3500  * Return number of errors when buffer head is not found or not marked up to
3501  * date.
3502  */
3503 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3504 {
3505         struct buffer_head *bh;
3506         int i;
3507         int errors = 0;
3508         bool primary_failed = false;
3509         u64 bytenr;
3510
3511         if (max_mirrors == 0)
3512                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3513
3514         for (i = 0; i < max_mirrors; i++) {
3515                 bytenr = btrfs_sb_offset(i);
3516                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3517                     device->commit_total_bytes)
3518                         break;
3519
3520                 bh = __find_get_block(device->bdev,
3521                                       bytenr / BTRFS_BDEV_BLOCKSIZE,
3522                                       BTRFS_SUPER_INFO_SIZE);
3523                 if (!bh) {
3524                         errors++;
3525                         if (i == 0)
3526                                 primary_failed = true;
3527                         continue;
3528                 }
3529                 wait_on_buffer(bh);
3530                 if (!buffer_uptodate(bh)) {
3531                         errors++;
3532                         if (i == 0)
3533                                 primary_failed = true;
3534                 }
3535
3536                 /* drop our reference */
3537                 brelse(bh);
3538
3539                 /* drop the reference from the writing run */
3540                 brelse(bh);
3541         }
3542
3543         /* log error, force error return */
3544         if (primary_failed) {
3545                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3546                           device->devid);
3547                 return -1;
3548         }
3549
3550         return errors < i ? 0 : -1;
3551 }
3552
3553 /*
3554  * endio for the write_dev_flush, this will wake anyone waiting
3555  * for the barrier when it is done
3556  */
3557 static void btrfs_end_empty_barrier(struct bio *bio)
3558 {
3559         complete(bio->bi_private);
3560 }
3561
3562 /*
3563  * Submit a flush request to the device if it supports it. Error handling is
3564  * done in the waiting counterpart.
3565  */
3566 static void write_dev_flush(struct btrfs_device *device)
3567 {
3568         struct request_queue *q = bdev_get_queue(device->bdev);
3569         struct bio *bio = device->flush_bio;
3570
3571         if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
3572                 return;
3573
3574         bio_reset(bio);
3575         bio->bi_end_io = btrfs_end_empty_barrier;
3576         bio_set_dev(bio, device->bdev);
3577         bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
3578         init_completion(&device->flush_wait);
3579         bio->bi_private = &device->flush_wait;
3580
3581         btrfsic_submit_bio(bio);
3582         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3583 }
3584
3585 /*
3586  * If the flush bio has been submitted by write_dev_flush, wait for it.
3587  */
3588 static blk_status_t wait_dev_flush(struct btrfs_device *device)
3589 {
3590         struct bio *bio = device->flush_bio;
3591
3592         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
3593                 return BLK_STS_OK;
3594
3595         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3596         wait_for_completion_io(&device->flush_wait);
3597
3598         return bio->bi_status;
3599 }
3600
3601 static int check_barrier_error(struct btrfs_fs_info *fs_info)
3602 {
3603         if (!btrfs_check_rw_degradable(fs_info, NULL))
3604                 return -EIO;
3605         return 0;
3606 }
3607
3608 /*
3609  * send an empty flush down to each device in parallel,
3610  * then wait for them
3611  */
3612 static int barrier_all_devices(struct btrfs_fs_info *info)
3613 {
3614         struct list_head *head;
3615         struct btrfs_device *dev;
3616         int errors_wait = 0;
3617         blk_status_t ret;
3618
3619         lockdep_assert_held(&info->fs_devices->device_list_mutex);
3620         /* send down all the barriers */
3621         head = &info->fs_devices->devices;
3622         list_for_each_entry(dev, head, dev_list) {
3623                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3624                         continue;
3625                 if (!dev->bdev)
3626                         continue;
3627                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3628                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3629                         continue;
3630
3631                 write_dev_flush(dev);
3632                 dev->last_flush_error = BLK_STS_OK;
3633         }
3634
3635         /* wait for all the barriers */
3636         list_for_each_entry(dev, head, dev_list) {
3637                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3638                         continue;
3639                 if (!dev->bdev) {
3640                         errors_wait++;
3641                         continue;
3642                 }
3643                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3644                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3645                         continue;
3646
3647                 ret = wait_dev_flush(dev);
3648                 if (ret) {
3649                         dev->last_flush_error = ret;
3650                         btrfs_dev_stat_inc_and_print(dev,
3651                                         BTRFS_DEV_STAT_FLUSH_ERRS);
3652                         errors_wait++;
3653                 }
3654         }
3655
3656         if (errors_wait) {
3657                 /*
3658                  * At some point we need the status of all disks
3659                  * to arrive at the volume status. So error checking
3660                  * is being pushed to a separate loop.
3661                  */
3662                 return check_barrier_error(info);
3663         }
3664         return 0;
3665 }
3666
3667 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
3668 {
3669         int raid_type;
3670         int min_tolerated = INT_MAX;
3671
3672         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
3673             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
3674                 min_tolerated = min(min_tolerated,
3675                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
3676                                     tolerated_failures);
3677
3678         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3679                 if (raid_type == BTRFS_RAID_SINGLE)
3680                         continue;
3681                 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
3682                         continue;
3683                 min_tolerated = min(min_tolerated,
3684                                     btrfs_raid_array[raid_type].
3685                                     tolerated_failures);
3686         }
3687
3688         if (min_tolerated == INT_MAX) {
3689                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
3690                 min_tolerated = 0;
3691         }
3692
3693         return min_tolerated;
3694 }
3695
3696 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
3697 {
3698         struct list_head *head;
3699         struct btrfs_device *dev;
3700         struct btrfs_super_block *sb;
3701         struct btrfs_dev_item *dev_item;
3702         int ret;
3703         int do_barriers;
3704         int max_errors;
3705         int total_errors = 0;
3706         u64 flags;
3707
3708         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
3709
3710         /*
3711          * max_mirrors == 0 indicates we're from commit_transaction,
3712          * not from fsync where the tree roots in fs_info have not
3713          * been consistent on disk.
3714          */
3715         if (max_mirrors == 0)
3716                 backup_super_roots(fs_info);
3717
3718         sb = fs_info->super_for_commit;
3719         dev_item = &sb->dev_item;
3720
3721         mutex_lock(&fs_info->fs_devices->device_list_mutex);
3722         head = &fs_info->fs_devices->devices;
3723         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
3724
3725         if (do_barriers) {
3726                 ret = barrier_all_devices(fs_info);
3727                 if (ret) {
3728                         mutex_unlock(
3729                                 &fs_info->fs_devices->device_list_mutex);
3730                         btrfs_handle_fs_error(fs_info, ret,
3731                                               "errors while submitting device barriers.");
3732                         return ret;
3733                 }
3734         }
3735
3736         list_for_each_entry(dev, head, dev_list) {
3737                 if (!dev->bdev) {
3738                         total_errors++;
3739                         continue;
3740                 }
3741                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3742                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3743                         continue;
3744
3745                 btrfs_set_stack_device_generation(dev_item, 0);
3746                 btrfs_set_stack_device_type(dev_item, dev->type);
3747                 btrfs_set_stack_device_id(dev_item, dev->devid);
3748                 btrfs_set_stack_device_total_bytes(dev_item,
3749                                                    dev->commit_total_bytes);
3750                 btrfs_set_stack_device_bytes_used(dev_item,
3751                                                   dev->commit_bytes_used);
3752                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3753                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3754                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3755                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3756                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_FSID_SIZE);
3757
3758                 flags = btrfs_super_flags(sb);
3759                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3760
3761                 ret = btrfs_validate_write_super(fs_info, sb);
3762                 if (ret < 0) {
3763                         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3764                         btrfs_handle_fs_error(fs_info, -EUCLEAN,
3765                                 "unexpected superblock corruption detected");
3766                         return -EUCLEAN;
3767                 }
3768
3769                 ret = write_dev_supers(dev, sb, max_mirrors);
3770                 if (ret)
3771                         total_errors++;
3772         }
3773         if (total_errors > max_errors) {
3774                 btrfs_err(fs_info, "%d errors while writing supers",
3775                           total_errors);
3776                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3777
3778                 /* FUA is masked off if unsupported and can't be the reason */
3779                 btrfs_handle_fs_error(fs_info, -EIO,
3780                                       "%d errors while writing supers",