b203982d66bcf14cee2880d6b8fc3877dd52a850
[sfrench/cifs-2.6.git] / fs / btrfs / disk-io.c
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/slab.h>
29 #include <linux/migrate.h>
30 #include <linux/ratelimit.h>
31 #include <linux/uuid.h>
32 #include <linux/semaphore.h>
33 #include <linux/error-injection.h>
34 #include <linux/crc32c.h>
35 #include <asm/unaligned.h>
36 #include "ctree.h"
37 #include "disk-io.h"
38 #include "transaction.h"
39 #include "btrfs_inode.h"
40 #include "volumes.h"
41 #include "print-tree.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "free-space-tree.h"
46 #include "inode-map.h"
47 #include "check-integrity.h"
48 #include "rcu-string.h"
49 #include "dev-replace.h"
50 #include "raid56.h"
51 #include "sysfs.h"
52 #include "qgroup.h"
53 #include "compression.h"
54 #include "tree-checker.h"
55 #include "ref-verify.h"
56
57 #ifdef CONFIG_X86
58 #include <asm/cpufeature.h>
59 #endif
60
61 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
62                                  BTRFS_HEADER_FLAG_RELOC |\
63                                  BTRFS_SUPER_FLAG_ERROR |\
64                                  BTRFS_SUPER_FLAG_SEEDING |\
65                                  BTRFS_SUPER_FLAG_METADUMP |\
66                                  BTRFS_SUPER_FLAG_METADUMP_V2)
67
68 static const struct extent_io_ops btree_extent_io_ops;
69 static void end_workqueue_fn(struct btrfs_work *work);
70 static void free_fs_root(struct btrfs_root *root);
71 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info);
72 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
73 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
74                                       struct btrfs_fs_info *fs_info);
75 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
76 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
77                                         struct extent_io_tree *dirty_pages,
78                                         int mark);
79 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
80                                        struct extent_io_tree *pinned_extents);
81 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
82 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
83
84 /*
85  * btrfs_end_io_wq structs are used to do processing in task context when an IO
86  * is complete.  This is used during reads to verify checksums, and it is used
87  * by writes to insert metadata for new file extents after IO is complete.
88  */
89 struct btrfs_end_io_wq {
90         struct bio *bio;
91         bio_end_io_t *end_io;
92         void *private;
93         struct btrfs_fs_info *info;
94         blk_status_t status;
95         enum btrfs_wq_endio_type metadata;
96         struct btrfs_work work;
97 };
98
99 static struct kmem_cache *btrfs_end_io_wq_cache;
100
101 int __init btrfs_end_io_wq_init(void)
102 {
103         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
104                                         sizeof(struct btrfs_end_io_wq),
105                                         0,
106                                         SLAB_MEM_SPREAD,
107                                         NULL);
108         if (!btrfs_end_io_wq_cache)
109                 return -ENOMEM;
110         return 0;
111 }
112
113 void __cold btrfs_end_io_wq_exit(void)
114 {
115         kmem_cache_destroy(btrfs_end_io_wq_cache);
116 }
117
118 /*
119  * async submit bios are used to offload expensive checksumming
120  * onto the worker threads.  They checksum file and metadata bios
121  * just before they are sent down the IO stack.
122  */
123 struct async_submit_bio {
124         void *private_data;
125         struct btrfs_fs_info *fs_info;
126         struct bio *bio;
127         extent_submit_bio_start_t *submit_bio_start;
128         extent_submit_bio_done_t *submit_bio_done;
129         int mirror_num;
130         unsigned long bio_flags;
131         /*
132          * bio_offset is optional, can be used if the pages in the bio
133          * can't tell us where in the file the bio should go
134          */
135         u64 bio_offset;
136         struct btrfs_work work;
137         blk_status_t status;
138 };
139
140 /*
141  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
142  * eb, the lockdep key is determined by the btrfs_root it belongs to and
143  * the level the eb occupies in the tree.
144  *
145  * Different roots are used for different purposes and may nest inside each
146  * other and they require separate keysets.  As lockdep keys should be
147  * static, assign keysets according to the purpose of the root as indicated
148  * by btrfs_root->objectid.  This ensures that all special purpose roots
149  * have separate keysets.
150  *
151  * Lock-nesting across peer nodes is always done with the immediate parent
152  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
153  * subclass to avoid triggering lockdep warning in such cases.
154  *
155  * The key is set by the readpage_end_io_hook after the buffer has passed
156  * csum validation but before the pages are unlocked.  It is also set by
157  * btrfs_init_new_buffer on freshly allocated blocks.
158  *
159  * We also add a check to make sure the highest level of the tree is the
160  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
161  * needs update as well.
162  */
163 #ifdef CONFIG_DEBUG_LOCK_ALLOC
164 # if BTRFS_MAX_LEVEL != 8
165 #  error
166 # endif
167
168 static struct btrfs_lockdep_keyset {
169         u64                     id;             /* root objectid */
170         const char              *name_stem;     /* lock name stem */
171         char                    names[BTRFS_MAX_LEVEL + 1][20];
172         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
173 } btrfs_lockdep_keysets[] = {
174         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
175         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
176         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
177         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
178         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
179         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
180         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
181         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
182         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
183         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
184         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
185         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
186         { .id = 0,                              .name_stem = "tree"     },
187 };
188
189 void __init btrfs_init_lockdep(void)
190 {
191         int i, j;
192
193         /* initialize lockdep class names */
194         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
195                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
196
197                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
198                         snprintf(ks->names[j], sizeof(ks->names[j]),
199                                  "btrfs-%s-%02d", ks->name_stem, j);
200         }
201 }
202
203 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
204                                     int level)
205 {
206         struct btrfs_lockdep_keyset *ks;
207
208         BUG_ON(level >= ARRAY_SIZE(ks->keys));
209
210         /* find the matching keyset, id 0 is the default entry */
211         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
212                 if (ks->id == objectid)
213                         break;
214
215         lockdep_set_class_and_name(&eb->lock,
216                                    &ks->keys[level], ks->names[level]);
217 }
218
219 #endif
220
221 /*
222  * extents on the btree inode are pretty simple, there's one extent
223  * that covers the entire device
224  */
225 struct extent_map *btree_get_extent(struct btrfs_inode *inode,
226                 struct page *page, size_t pg_offset, u64 start, u64 len,
227                 int create)
228 {
229         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
230         struct extent_map_tree *em_tree = &inode->extent_tree;
231         struct extent_map *em;
232         int ret;
233
234         read_lock(&em_tree->lock);
235         em = lookup_extent_mapping(em_tree, start, len);
236         if (em) {
237                 em->bdev = fs_info->fs_devices->latest_bdev;
238                 read_unlock(&em_tree->lock);
239                 goto out;
240         }
241         read_unlock(&em_tree->lock);
242
243         em = alloc_extent_map();
244         if (!em) {
245                 em = ERR_PTR(-ENOMEM);
246                 goto out;
247         }
248         em->start = 0;
249         em->len = (u64)-1;
250         em->block_len = (u64)-1;
251         em->block_start = 0;
252         em->bdev = fs_info->fs_devices->latest_bdev;
253
254         write_lock(&em_tree->lock);
255         ret = add_extent_mapping(em_tree, em, 0);
256         if (ret == -EEXIST) {
257                 free_extent_map(em);
258                 em = lookup_extent_mapping(em_tree, start, len);
259                 if (!em)
260                         em = ERR_PTR(-EIO);
261         } else if (ret) {
262                 free_extent_map(em);
263                 em = ERR_PTR(ret);
264         }
265         write_unlock(&em_tree->lock);
266
267 out:
268         return em;
269 }
270
271 u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
272 {
273         return crc32c(seed, data, len);
274 }
275
276 void btrfs_csum_final(u32 crc, u8 *result)
277 {
278         put_unaligned_le32(~crc, result);
279 }
280
281 /*
282  * compute the csum for a btree block, and either verify it or write it
283  * into the csum field of the block.
284  */
285 static int csum_tree_block(struct btrfs_fs_info *fs_info,
286                            struct extent_buffer *buf,
287                            int verify)
288 {
289         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
290         char result[BTRFS_CSUM_SIZE];
291         unsigned long len;
292         unsigned long cur_len;
293         unsigned long offset = BTRFS_CSUM_SIZE;
294         char *kaddr;
295         unsigned long map_start;
296         unsigned long map_len;
297         int err;
298         u32 crc = ~(u32)0;
299
300         len = buf->len - offset;
301         while (len > 0) {
302                 err = map_private_extent_buffer(buf, offset, 32,
303                                         &kaddr, &map_start, &map_len);
304                 if (err)
305                         return err;
306                 cur_len = min(len, map_len - (offset - map_start));
307                 crc = btrfs_csum_data(kaddr + offset - map_start,
308                                       crc, cur_len);
309                 len -= cur_len;
310                 offset += cur_len;
311         }
312         memset(result, 0, BTRFS_CSUM_SIZE);
313
314         btrfs_csum_final(crc, result);
315
316         if (verify) {
317                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
318                         u32 val;
319                         u32 found = 0;
320                         memcpy(&found, result, csum_size);
321
322                         read_extent_buffer(buf, &val, 0, csum_size);
323                         btrfs_warn_rl(fs_info,
324                                 "%s checksum verify failed on %llu wanted %X found %X level %d",
325                                 fs_info->sb->s_id, buf->start,
326                                 val, found, btrfs_header_level(buf));
327                         return -EUCLEAN;
328                 }
329         } else {
330                 write_extent_buffer(buf, result, 0, csum_size);
331         }
332
333         return 0;
334 }
335
336 /*
337  * we can't consider a given block up to date unless the transid of the
338  * block matches the transid in the parent node's pointer.  This is how we
339  * detect blocks that either didn't get written at all or got written
340  * in the wrong place.
341  */
342 static int verify_parent_transid(struct extent_io_tree *io_tree,
343                                  struct extent_buffer *eb, u64 parent_transid,
344                                  int atomic)
345 {
346         struct extent_state *cached_state = NULL;
347         int ret;
348         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
349
350         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
351                 return 0;
352
353         if (atomic)
354                 return -EAGAIN;
355
356         if (need_lock) {
357                 btrfs_tree_read_lock(eb);
358                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
359         }
360
361         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
362                          &cached_state);
363         if (extent_buffer_uptodate(eb) &&
364             btrfs_header_generation(eb) == parent_transid) {
365                 ret = 0;
366                 goto out;
367         }
368         btrfs_err_rl(eb->fs_info,
369                 "parent transid verify failed on %llu wanted %llu found %llu",
370                         eb->start,
371                         parent_transid, btrfs_header_generation(eb));
372         ret = 1;
373
374         /*
375          * Things reading via commit roots that don't have normal protection,
376          * like send, can have a really old block in cache that may point at a
377          * block that has been freed and re-allocated.  So don't clear uptodate
378          * if we find an eb that is under IO (dirty/writeback) because we could
379          * end up reading in the stale data and then writing it back out and
380          * making everybody very sad.
381          */
382         if (!extent_buffer_under_io(eb))
383                 clear_extent_buffer_uptodate(eb);
384 out:
385         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
386                              &cached_state);
387         if (need_lock)
388                 btrfs_tree_read_unlock_blocking(eb);
389         return ret;
390 }
391
392 /*
393  * Return 0 if the superblock checksum type matches the checksum value of that
394  * algorithm. Pass the raw disk superblock data.
395  */
396 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
397                                   char *raw_disk_sb)
398 {
399         struct btrfs_super_block *disk_sb =
400                 (struct btrfs_super_block *)raw_disk_sb;
401         u16 csum_type = btrfs_super_csum_type(disk_sb);
402         int ret = 0;
403
404         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
405                 u32 crc = ~(u32)0;
406                 char result[sizeof(crc)];
407
408                 /*
409                  * The super_block structure does not span the whole
410                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
411                  * is filled with zeros and is included in the checksum.
412                  */
413                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
414                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
415                 btrfs_csum_final(crc, result);
416
417                 if (memcmp(raw_disk_sb, result, sizeof(result)))
418                         ret = 1;
419         }
420
421         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
422                 btrfs_err(fs_info, "unsupported checksum algorithm %u",
423                                 csum_type);
424                 ret = 1;
425         }
426
427         return ret;
428 }
429
430 /*
431  * helper to read a given tree block, doing retries as required when
432  * the checksums don't match and we have alternate mirrors to try.
433  */
434 static int btree_read_extent_buffer_pages(struct btrfs_fs_info *fs_info,
435                                           struct extent_buffer *eb,
436                                           u64 parent_transid)
437 {
438         struct extent_io_tree *io_tree;
439         int failed = 0;
440         int ret;
441         int num_copies = 0;
442         int mirror_num = 0;
443         int failed_mirror = 0;
444
445         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
446         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
447         while (1) {
448                 ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
449                                                mirror_num);
450                 if (!ret) {
451                         if (!verify_parent_transid(io_tree, eb,
452                                                    parent_transid, 0))
453                                 break;
454                         else
455                                 ret = -EIO;
456                 }
457
458                 /*
459                  * This buffer's crc is fine, but its contents are corrupted, so
460                  * there is no reason to read the other copies, they won't be
461                  * any less wrong.
462                  */
463                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
464                         break;
465
466                 num_copies = btrfs_num_copies(fs_info,
467                                               eb->start, eb->len);
468                 if (num_copies == 1)
469                         break;
470
471                 if (!failed_mirror) {
472                         failed = 1;
473                         failed_mirror = eb->read_mirror;
474                 }
475
476                 mirror_num++;
477                 if (mirror_num == failed_mirror)
478                         mirror_num++;
479
480                 if (mirror_num > num_copies)
481                         break;
482         }
483
484         if (failed && !ret && failed_mirror)
485                 repair_eb_io_failure(fs_info, eb, failed_mirror);
486
487         return ret;
488 }
489
490 /*
491  * checksum a dirty tree block before IO.  This has extra checks to make sure
492  * we only fill in the checksum field in the first page of a multi-page block
493  */
494
495 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
496 {
497         u64 start = page_offset(page);
498         u64 found_start;
499         struct extent_buffer *eb;
500
501         eb = (struct extent_buffer *)page->private;
502         if (page != eb->pages[0])
503                 return 0;
504
505         found_start = btrfs_header_bytenr(eb);
506         /*
507          * Please do not consolidate these warnings into a single if.
508          * It is useful to know what went wrong.
509          */
510         if (WARN_ON(found_start != start))
511                 return -EUCLEAN;
512         if (WARN_ON(!PageUptodate(page)))
513                 return -EUCLEAN;
514
515         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
516                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
517
518         return csum_tree_block(fs_info, eb, 0);
519 }
520
521 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
522                                  struct extent_buffer *eb)
523 {
524         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
525         u8 fsid[BTRFS_FSID_SIZE];
526         int ret = 1;
527
528         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
529         while (fs_devices) {
530                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
531                         ret = 0;
532                         break;
533                 }
534                 fs_devices = fs_devices->seed;
535         }
536         return ret;
537 }
538
539 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
540                                       u64 phy_offset, struct page *page,
541                                       u64 start, u64 end, int mirror)
542 {
543         u64 found_start;
544         int found_level;
545         struct extent_buffer *eb;
546         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
547         struct btrfs_fs_info *fs_info = root->fs_info;
548         int ret = 0;
549         int reads_done;
550
551         if (!page->private)
552                 goto out;
553
554         eb = (struct extent_buffer *)page->private;
555
556         /* the pending IO might have been the only thing that kept this buffer
557          * in memory.  Make sure we have a ref for all this other checks
558          */
559         extent_buffer_get(eb);
560
561         reads_done = atomic_dec_and_test(&eb->io_pages);
562         if (!reads_done)
563                 goto err;
564
565         eb->read_mirror = mirror;
566         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
567                 ret = -EIO;
568                 goto err;
569         }
570
571         found_start = btrfs_header_bytenr(eb);
572         if (found_start != eb->start) {
573                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
574                              found_start, eb->start);
575                 ret = -EIO;
576                 goto err;
577         }
578         if (check_tree_block_fsid(fs_info, eb)) {
579                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
580                              eb->start);
581                 ret = -EIO;
582                 goto err;
583         }
584         found_level = btrfs_header_level(eb);
585         if (found_level >= BTRFS_MAX_LEVEL) {
586                 btrfs_err(fs_info, "bad tree block level %d",
587                           (int)btrfs_header_level(eb));
588                 ret = -EIO;
589                 goto err;
590         }
591
592         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
593                                        eb, found_level);
594
595         ret = csum_tree_block(fs_info, eb, 1);
596         if (ret)
597                 goto err;
598
599         /*
600          * If this is a leaf block and it is corrupt, set the corrupt bit so
601          * that we don't try and read the other copies of this block, just
602          * return -EIO.
603          */
604         if (found_level == 0 && btrfs_check_leaf_full(fs_info, eb)) {
605                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
606                 ret = -EIO;
607         }
608
609         if (found_level > 0 && btrfs_check_node(fs_info, eb))
610                 ret = -EIO;
611
612         if (!ret)
613                 set_extent_buffer_uptodate(eb);
614 err:
615         if (reads_done &&
616             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
617                 btree_readahead_hook(eb, ret);
618
619         if (ret) {
620                 /*
621                  * our io error hook is going to dec the io pages
622                  * again, we have to make sure it has something
623                  * to decrement
624                  */
625                 atomic_inc(&eb->io_pages);
626                 clear_extent_buffer_uptodate(eb);
627         }
628         free_extent_buffer(eb);
629 out:
630         return ret;
631 }
632
633 static int btree_io_failed_hook(struct page *page, int failed_mirror)
634 {
635         struct extent_buffer *eb;
636
637         eb = (struct extent_buffer *)page->private;
638         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
639         eb->read_mirror = failed_mirror;
640         atomic_dec(&eb->io_pages);
641         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
642                 btree_readahead_hook(eb, -EIO);
643         return -EIO;    /* we fixed nothing */
644 }
645
646 static void end_workqueue_bio(struct bio *bio)
647 {
648         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
649         struct btrfs_fs_info *fs_info;
650         struct btrfs_workqueue *wq;
651         btrfs_work_func_t func;
652
653         fs_info = end_io_wq->info;
654         end_io_wq->status = bio->bi_status;
655
656         if (bio_op(bio) == REQ_OP_WRITE) {
657                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
658                         wq = fs_info->endio_meta_write_workers;
659                         func = btrfs_endio_meta_write_helper;
660                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
661                         wq = fs_info->endio_freespace_worker;
662                         func = btrfs_freespace_write_helper;
663                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
664                         wq = fs_info->endio_raid56_workers;
665                         func = btrfs_endio_raid56_helper;
666                 } else {
667                         wq = fs_info->endio_write_workers;
668                         func = btrfs_endio_write_helper;
669                 }
670         } else {
671                 if (unlikely(end_io_wq->metadata ==
672                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
673                         wq = fs_info->endio_repair_workers;
674                         func = btrfs_endio_repair_helper;
675                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
676                         wq = fs_info->endio_raid56_workers;
677                         func = btrfs_endio_raid56_helper;
678                 } else if (end_io_wq->metadata) {
679                         wq = fs_info->endio_meta_workers;
680                         func = btrfs_endio_meta_helper;
681                 } else {
682                         wq = fs_info->endio_workers;
683                         func = btrfs_endio_helper;
684                 }
685         }
686
687         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
688         btrfs_queue_work(wq, &end_io_wq->work);
689 }
690
691 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
692                         enum btrfs_wq_endio_type metadata)
693 {
694         struct btrfs_end_io_wq *end_io_wq;
695
696         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
697         if (!end_io_wq)
698                 return BLK_STS_RESOURCE;
699
700         end_io_wq->private = bio->bi_private;
701         end_io_wq->end_io = bio->bi_end_io;
702         end_io_wq->info = info;
703         end_io_wq->status = 0;
704         end_io_wq->bio = bio;
705         end_io_wq->metadata = metadata;
706
707         bio->bi_private = end_io_wq;
708         bio->bi_end_io = end_workqueue_bio;
709         return 0;
710 }
711
712 static void run_one_async_start(struct btrfs_work *work)
713 {
714         struct async_submit_bio *async;
715         blk_status_t ret;
716
717         async = container_of(work, struct  async_submit_bio, work);
718         ret = async->submit_bio_start(async->private_data, async->bio,
719                                       async->bio_offset);
720         if (ret)
721                 async->status = ret;
722 }
723
724 static void run_one_async_done(struct btrfs_work *work)
725 {
726         struct async_submit_bio *async;
727
728         async = container_of(work, struct  async_submit_bio, work);
729
730         /* If an error occurred we just want to clean up the bio and move on */
731         if (async->status) {
732                 async->bio->bi_status = async->status;
733                 bio_endio(async->bio);
734                 return;
735         }
736
737         async->submit_bio_done(async->private_data, async->bio, async->mirror_num);
738 }
739
740 static void run_one_async_free(struct btrfs_work *work)
741 {
742         struct async_submit_bio *async;
743
744         async = container_of(work, struct  async_submit_bio, work);
745         kfree(async);
746 }
747
748 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
749                                  int mirror_num, unsigned long bio_flags,
750                                  u64 bio_offset, void *private_data,
751                                  extent_submit_bio_start_t *submit_bio_start,
752                                  extent_submit_bio_done_t *submit_bio_done)
753 {
754         struct async_submit_bio *async;
755
756         async = kmalloc(sizeof(*async), GFP_NOFS);
757         if (!async)
758                 return BLK_STS_RESOURCE;
759
760         async->private_data = private_data;
761         async->fs_info = fs_info;
762         async->bio = bio;
763         async->mirror_num = mirror_num;
764         async->submit_bio_start = submit_bio_start;
765         async->submit_bio_done = submit_bio_done;
766
767         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
768                         run_one_async_done, run_one_async_free);
769
770         async->bio_flags = bio_flags;
771         async->bio_offset = bio_offset;
772
773         async->status = 0;
774
775         if (op_is_sync(bio->bi_opf))
776                 btrfs_set_work_high_priority(&async->work);
777
778         btrfs_queue_work(fs_info->workers, &async->work);
779         return 0;
780 }
781
782 static blk_status_t btree_csum_one_bio(struct bio *bio)
783 {
784         struct bio_vec *bvec;
785         struct btrfs_root *root;
786         int i, ret = 0;
787
788         ASSERT(!bio_flagged(bio, BIO_CLONED));
789         bio_for_each_segment_all(bvec, bio, i) {
790                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
791                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
792                 if (ret)
793                         break;
794         }
795
796         return errno_to_blk_status(ret);
797 }
798
799 static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio,
800                                              u64 bio_offset)
801 {
802         /*
803          * when we're called for a write, we're already in the async
804          * submission context.  Just jump into btrfs_map_bio
805          */
806         return btree_csum_one_bio(bio);
807 }
808
809 static blk_status_t btree_submit_bio_done(void *private_data, struct bio *bio,
810                                             int mirror_num)
811 {
812         struct inode *inode = private_data;
813         blk_status_t ret;
814
815         /*
816          * when we're called for a write, we're already in the async
817          * submission context.  Just jump into btrfs_map_bio
818          */
819         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), bio, mirror_num, 1);
820         if (ret) {
821                 bio->bi_status = ret;
822                 bio_endio(bio);
823         }
824         return ret;
825 }
826
827 static int check_async_write(struct btrfs_inode *bi)
828 {
829         if (atomic_read(&bi->sync_writers))
830                 return 0;
831 #ifdef CONFIG_X86
832         if (static_cpu_has(X86_FEATURE_XMM4_2))
833                 return 0;
834 #endif
835         return 1;
836 }
837
838 static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
839                                           int mirror_num, unsigned long bio_flags,
840                                           u64 bio_offset)
841 {
842         struct inode *inode = private_data;
843         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
844         int async = check_async_write(BTRFS_I(inode));
845         blk_status_t ret;
846
847         if (bio_op(bio) != REQ_OP_WRITE) {
848                 /*
849                  * called for a read, do the setup so that checksum validation
850                  * can happen in the async kernel threads
851                  */
852                 ret = btrfs_bio_wq_end_io(fs_info, bio,
853                                           BTRFS_WQ_ENDIO_METADATA);
854                 if (ret)
855                         goto out_w_error;
856                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
857         } else if (!async) {
858                 ret = btree_csum_one_bio(bio);
859                 if (ret)
860                         goto out_w_error;
861                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
862         } else {
863                 /*
864                  * kthread helpers are used to submit writes so that
865                  * checksumming can happen in parallel across all CPUs
866                  */
867                 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
868                                           bio_offset, private_data,
869                                           btree_submit_bio_start,
870                                           btree_submit_bio_done);
871         }
872
873         if (ret)
874                 goto out_w_error;
875         return 0;
876
877 out_w_error:
878         bio->bi_status = ret;
879         bio_endio(bio);
880         return ret;
881 }
882
883 #ifdef CONFIG_MIGRATION
884 static int btree_migratepage(struct address_space *mapping,
885                         struct page *newpage, struct page *page,
886                         enum migrate_mode mode)
887 {
888         /*
889          * we can't safely write a btree page from here,
890          * we haven't done the locking hook
891          */
892         if (PageDirty(page))
893                 return -EAGAIN;
894         /*
895          * Buffers may be managed in a filesystem specific way.
896          * We must have no buffers or drop them.
897          */
898         if (page_has_private(page) &&
899             !try_to_release_page(page, GFP_KERNEL))
900                 return -EAGAIN;
901         return migrate_page(mapping, newpage, page, mode);
902 }
903 #endif
904
905
906 static int btree_writepages(struct address_space *mapping,
907                             struct writeback_control *wbc)
908 {
909         struct btrfs_fs_info *fs_info;
910         int ret;
911
912         if (wbc->sync_mode == WB_SYNC_NONE) {
913
914                 if (wbc->for_kupdate)
915                         return 0;
916
917                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
918                 /* this is a bit racy, but that's ok */
919                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
920                                              BTRFS_DIRTY_METADATA_THRESH);
921                 if (ret < 0)
922                         return 0;
923         }
924         return btree_write_cache_pages(mapping, wbc);
925 }
926
927 static int btree_readpage(struct file *file, struct page *page)
928 {
929         struct extent_io_tree *tree;
930         tree = &BTRFS_I(page->mapping->host)->io_tree;
931         return extent_read_full_page(tree, page, btree_get_extent, 0);
932 }
933
934 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
935 {
936         if (PageWriteback(page) || PageDirty(page))
937                 return 0;
938
939         return try_release_extent_buffer(page);
940 }
941
942 static void btree_invalidatepage(struct page *page, unsigned int offset,
943                                  unsigned int length)
944 {
945         struct extent_io_tree *tree;
946         tree = &BTRFS_I(page->mapping->host)->io_tree;
947         extent_invalidatepage(tree, page, offset);
948         btree_releasepage(page, GFP_NOFS);
949         if (PagePrivate(page)) {
950                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
951                            "page private not zero on page %llu",
952                            (unsigned long long)page_offset(page));
953                 ClearPagePrivate(page);
954                 set_page_private(page, 0);
955                 put_page(page);
956         }
957 }
958
959 static int btree_set_page_dirty(struct page *page)
960 {
961 #ifdef DEBUG
962         struct extent_buffer *eb;
963
964         BUG_ON(!PagePrivate(page));
965         eb = (struct extent_buffer *)page->private;
966         BUG_ON(!eb);
967         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
968         BUG_ON(!atomic_read(&eb->refs));
969         btrfs_assert_tree_locked(eb);
970 #endif
971         return __set_page_dirty_nobuffers(page);
972 }
973
974 static const struct address_space_operations btree_aops = {
975         .readpage       = btree_readpage,
976         .writepages     = btree_writepages,
977         .releasepage    = btree_releasepage,
978         .invalidatepage = btree_invalidatepage,
979 #ifdef CONFIG_MIGRATION
980         .migratepage    = btree_migratepage,
981 #endif
982         .set_page_dirty = btree_set_page_dirty,
983 };
984
985 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr)
986 {
987         struct extent_buffer *buf = NULL;
988         struct inode *btree_inode = fs_info->btree_inode;
989
990         buf = btrfs_find_create_tree_block(fs_info, bytenr);
991         if (IS_ERR(buf))
992                 return;
993         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
994                                  buf, WAIT_NONE, 0);
995         free_extent_buffer(buf);
996 }
997
998 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
999                          int mirror_num, struct extent_buffer **eb)
1000 {
1001         struct extent_buffer *buf = NULL;
1002         struct inode *btree_inode = fs_info->btree_inode;
1003         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1004         int ret;
1005
1006         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1007         if (IS_ERR(buf))
1008                 return 0;
1009
1010         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1011
1012         ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
1013                                        mirror_num);
1014         if (ret) {
1015                 free_extent_buffer(buf);
1016                 return ret;
1017         }
1018
1019         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1020                 free_extent_buffer(buf);
1021                 return -EIO;
1022         } else if (extent_buffer_uptodate(buf)) {
1023                 *eb = buf;
1024         } else {
1025                 free_extent_buffer(buf);
1026         }
1027         return 0;
1028 }
1029
1030 struct extent_buffer *btrfs_find_create_tree_block(
1031                                                 struct btrfs_fs_info *fs_info,
1032                                                 u64 bytenr)
1033 {
1034         if (btrfs_is_testing(fs_info))
1035                 return alloc_test_extent_buffer(fs_info, bytenr);
1036         return alloc_extent_buffer(fs_info, bytenr);
1037 }
1038
1039
1040 int btrfs_write_tree_block(struct extent_buffer *buf)
1041 {
1042         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1043                                         buf->start + buf->len - 1);
1044 }
1045
1046 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1047 {
1048         filemap_fdatawait_range(buf->pages[0]->mapping,
1049                                 buf->start, buf->start + buf->len - 1);
1050 }
1051
1052 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1053                                       u64 parent_transid)
1054 {
1055         struct extent_buffer *buf = NULL;
1056         int ret;
1057
1058         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1059         if (IS_ERR(buf))
1060                 return buf;
1061
1062         ret = btree_read_extent_buffer_pages(fs_info, buf, parent_transid);
1063         if (ret) {
1064                 free_extent_buffer(buf);
1065                 return ERR_PTR(ret);
1066         }
1067         return buf;
1068
1069 }
1070
1071 void clean_tree_block(struct btrfs_fs_info *fs_info,
1072                       struct extent_buffer *buf)
1073 {
1074         if (btrfs_header_generation(buf) ==
1075             fs_info->running_transaction->transid) {
1076                 btrfs_assert_tree_locked(buf);
1077
1078                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1079                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1080                                                  -buf->len,
1081                                                  fs_info->dirty_metadata_batch);
1082                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1083                         btrfs_set_lock_blocking(buf);
1084                         clear_extent_buffer_dirty(buf);
1085                 }
1086         }
1087 }
1088
1089 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1090 {
1091         struct btrfs_subvolume_writers *writers;
1092         int ret;
1093
1094         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1095         if (!writers)
1096                 return ERR_PTR(-ENOMEM);
1097
1098         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1099         if (ret < 0) {
1100                 kfree(writers);
1101                 return ERR_PTR(ret);
1102         }
1103
1104         init_waitqueue_head(&writers->wait);
1105         return writers;
1106 }
1107
1108 static void
1109 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1110 {
1111         percpu_counter_destroy(&writers->counter);
1112         kfree(writers);
1113 }
1114
1115 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1116                          u64 objectid)
1117 {
1118         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1119         root->node = NULL;
1120         root->commit_root = NULL;
1121         root->state = 0;
1122         root->orphan_cleanup_state = 0;
1123
1124         root->objectid = objectid;
1125         root->last_trans = 0;
1126         root->highest_objectid = 0;
1127         root->nr_delalloc_inodes = 0;
1128         root->nr_ordered_extents = 0;
1129         root->name = NULL;
1130         root->inode_tree = RB_ROOT;
1131         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1132         root->block_rsv = NULL;
1133         root->orphan_block_rsv = NULL;
1134
1135         INIT_LIST_HEAD(&root->dirty_list);
1136         INIT_LIST_HEAD(&root->root_list);
1137         INIT_LIST_HEAD(&root->delalloc_inodes);
1138         INIT_LIST_HEAD(&root->delalloc_root);
1139         INIT_LIST_HEAD(&root->ordered_extents);
1140         INIT_LIST_HEAD(&root->ordered_root);
1141         INIT_LIST_HEAD(&root->logged_list[0]);
1142         INIT_LIST_HEAD(&root->logged_list[1]);
1143         spin_lock_init(&root->orphan_lock);
1144         spin_lock_init(&root->inode_lock);
1145         spin_lock_init(&root->delalloc_lock);
1146         spin_lock_init(&root->ordered_extent_lock);
1147         spin_lock_init(&root->accounting_lock);
1148         spin_lock_init(&root->log_extents_lock[0]);
1149         spin_lock_init(&root->log_extents_lock[1]);
1150         mutex_init(&root->objectid_mutex);
1151         mutex_init(&root->log_mutex);
1152         mutex_init(&root->ordered_extent_mutex);
1153         mutex_init(&root->delalloc_mutex);
1154         init_waitqueue_head(&root->log_writer_wait);
1155         init_waitqueue_head(&root->log_commit_wait[0]);
1156         init_waitqueue_head(&root->log_commit_wait[1]);
1157         INIT_LIST_HEAD(&root->log_ctxs[0]);
1158         INIT_LIST_HEAD(&root->log_ctxs[1]);
1159         atomic_set(&root->log_commit[0], 0);
1160         atomic_set(&root->log_commit[1], 0);
1161         atomic_set(&root->log_writers, 0);
1162         atomic_set(&root->log_batch, 0);
1163         atomic_set(&root->orphan_inodes, 0);
1164         refcount_set(&root->refs, 1);
1165         atomic_set(&root->will_be_snapshotted, 0);
1166         atomic64_set(&root->qgroup_meta_rsv, 0);
1167         root->log_transid = 0;
1168         root->log_transid_committed = -1;
1169         root->last_log_commit = 0;
1170         if (!dummy)
1171                 extent_io_tree_init(&root->dirty_log_pages, NULL);
1172
1173         memset(&root->root_key, 0, sizeof(root->root_key));
1174         memset(&root->root_item, 0, sizeof(root->root_item));
1175         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1176         if (!dummy)
1177                 root->defrag_trans_start = fs_info->generation;
1178         else
1179                 root->defrag_trans_start = 0;
1180         root->root_key.objectid = objectid;
1181         root->anon_dev = 0;
1182
1183         spin_lock_init(&root->root_item_lock);
1184 }
1185
1186 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1187                 gfp_t flags)
1188 {
1189         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1190         if (root)
1191                 root->fs_info = fs_info;
1192         return root;
1193 }
1194
1195 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1196 /* Should only be used by the testing infrastructure */
1197 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1198 {
1199         struct btrfs_root *root;
1200
1201         if (!fs_info)
1202                 return ERR_PTR(-EINVAL);
1203
1204         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1205         if (!root)
1206                 return ERR_PTR(-ENOMEM);
1207
1208         /* We don't use the stripesize in selftest, set it as sectorsize */
1209         __setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1210         root->alloc_bytenr = 0;
1211
1212         return root;
1213 }
1214 #endif
1215
1216 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1217                                      struct btrfs_fs_info *fs_info,
1218                                      u64 objectid)
1219 {
1220         struct extent_buffer *leaf;
1221         struct btrfs_root *tree_root = fs_info->tree_root;
1222         struct btrfs_root *root;
1223         struct btrfs_key key;
1224         int ret = 0;
1225         uuid_le uuid = NULL_UUID_LE;
1226
1227         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1228         if (!root)
1229                 return ERR_PTR(-ENOMEM);
1230
1231         __setup_root(root, fs_info, objectid);
1232         root->root_key.objectid = objectid;
1233         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1234         root->root_key.offset = 0;
1235
1236         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1237         if (IS_ERR(leaf)) {
1238                 ret = PTR_ERR(leaf);
1239                 leaf = NULL;
1240                 goto fail;
1241         }
1242
1243         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1244         btrfs_set_header_bytenr(leaf, leaf->start);
1245         btrfs_set_header_generation(leaf, trans->transid);
1246         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1247         btrfs_set_header_owner(leaf, objectid);
1248         root->node = leaf;
1249
1250         write_extent_buffer_fsid(leaf, fs_info->fsid);
1251         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
1252         btrfs_mark_buffer_dirty(leaf);
1253
1254         root->commit_root = btrfs_root_node(root);
1255         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1256
1257         root->root_item.flags = 0;
1258         root->root_item.byte_limit = 0;
1259         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1260         btrfs_set_root_generation(&root->root_item, trans->transid);
1261         btrfs_set_root_level(&root->root_item, 0);
1262         btrfs_set_root_refs(&root->root_item, 1);
1263         btrfs_set_root_used(&root->root_item, leaf->len);
1264         btrfs_set_root_last_snapshot(&root->root_item, 0);
1265         btrfs_set_root_dirid(&root->root_item, 0);
1266         if (is_fstree(objectid))
1267                 uuid_le_gen(&uuid);
1268         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1269         root->root_item.drop_level = 0;
1270
1271         key.objectid = objectid;
1272         key.type = BTRFS_ROOT_ITEM_KEY;
1273         key.offset = 0;
1274         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1275         if (ret)
1276                 goto fail;
1277
1278         btrfs_tree_unlock(leaf);
1279
1280         return root;
1281
1282 fail:
1283         if (leaf) {
1284                 btrfs_tree_unlock(leaf);
1285                 free_extent_buffer(root->commit_root);
1286                 free_extent_buffer(leaf);
1287         }
1288         kfree(root);
1289
1290         return ERR_PTR(ret);
1291 }
1292
1293 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1294                                          struct btrfs_fs_info *fs_info)
1295 {
1296         struct btrfs_root *root;
1297         struct extent_buffer *leaf;
1298
1299         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1300         if (!root)
1301                 return ERR_PTR(-ENOMEM);
1302
1303         __setup_root(root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1304
1305         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1306         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1307         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1308
1309         /*
1310          * DON'T set REF_COWS for log trees
1311          *
1312          * log trees do not get reference counted because they go away
1313          * before a real commit is actually done.  They do store pointers
1314          * to file data extents, and those reference counts still get
1315          * updated (along with back refs to the log tree).
1316          */
1317
1318         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1319                         NULL, 0, 0, 0);
1320         if (IS_ERR(leaf)) {
1321                 kfree(root);
1322                 return ERR_CAST(leaf);
1323         }
1324
1325         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1326         btrfs_set_header_bytenr(leaf, leaf->start);
1327         btrfs_set_header_generation(leaf, trans->transid);
1328         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1329         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1330         root->node = leaf;
1331
1332         write_extent_buffer_fsid(root->node, fs_info->fsid);
1333         btrfs_mark_buffer_dirty(root->node);
1334         btrfs_tree_unlock(root->node);
1335         return root;
1336 }
1337
1338 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1339                              struct btrfs_fs_info *fs_info)
1340 {
1341         struct btrfs_root *log_root;
1342
1343         log_root = alloc_log_tree(trans, fs_info);
1344         if (IS_ERR(log_root))
1345                 return PTR_ERR(log_root);
1346         WARN_ON(fs_info->log_root_tree);
1347         fs_info->log_root_tree = log_root;
1348         return 0;
1349 }
1350
1351 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1352                        struct btrfs_root *root)
1353 {
1354         struct btrfs_fs_info *fs_info = root->fs_info;
1355         struct btrfs_root *log_root;
1356         struct btrfs_inode_item *inode_item;
1357
1358         log_root = alloc_log_tree(trans, fs_info);
1359         if (IS_ERR(log_root))
1360                 return PTR_ERR(log_root);
1361
1362         log_root->last_trans = trans->transid;
1363         log_root->root_key.offset = root->root_key.objectid;
1364
1365         inode_item = &log_root->root_item.inode;
1366         btrfs_set_stack_inode_generation(inode_item, 1);
1367         btrfs_set_stack_inode_size(inode_item, 3);
1368         btrfs_set_stack_inode_nlink(inode_item, 1);
1369         btrfs_set_stack_inode_nbytes(inode_item,
1370                                      fs_info->nodesize);
1371         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1372
1373         btrfs_set_root_node(&log_root->root_item, log_root->node);
1374
1375         WARN_ON(root->log_root);
1376         root->log_root = log_root;
1377         root->log_transid = 0;
1378         root->log_transid_committed = -1;
1379         root->last_log_commit = 0;
1380         return 0;
1381 }
1382
1383 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1384                                                struct btrfs_key *key)
1385 {
1386         struct btrfs_root *root;
1387         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1388         struct btrfs_path *path;
1389         u64 generation;
1390         int ret;
1391
1392         path = btrfs_alloc_path();
1393         if (!path)
1394                 return ERR_PTR(-ENOMEM);
1395
1396         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1397         if (!root) {
1398                 ret = -ENOMEM;
1399                 goto alloc_fail;
1400         }
1401
1402         __setup_root(root, fs_info, key->objectid);
1403
1404         ret = btrfs_find_root(tree_root, key, path,
1405                               &root->root_item, &root->root_key);
1406         if (ret) {
1407                 if (ret > 0)
1408                         ret = -ENOENT;
1409                 goto find_fail;
1410         }
1411
1412         generation = btrfs_root_generation(&root->root_item);
1413         root->node = read_tree_block(fs_info,
1414                                      btrfs_root_bytenr(&root->root_item),
1415                                      generation);
1416         if (IS_ERR(root->node)) {
1417                 ret = PTR_ERR(root->node);
1418                 goto find_fail;
1419         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1420                 ret = -EIO;
1421                 free_extent_buffer(root->node);
1422                 goto find_fail;
1423         }
1424         root->commit_root = btrfs_root_node(root);
1425 out:
1426         btrfs_free_path(path);
1427         return root;
1428
1429 find_fail:
1430         kfree(root);
1431 alloc_fail:
1432         root = ERR_PTR(ret);
1433         goto out;
1434 }
1435
1436 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1437                                       struct btrfs_key *location)
1438 {
1439         struct btrfs_root *root;
1440
1441         root = btrfs_read_tree_root(tree_root, location);
1442         if (IS_ERR(root))
1443                 return root;
1444
1445         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1446                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1447                 btrfs_check_and_init_root_item(&root->root_item);
1448         }
1449
1450         return root;
1451 }
1452
1453 int btrfs_init_fs_root(struct btrfs_root *root)
1454 {
1455         int ret;
1456         struct btrfs_subvolume_writers *writers;
1457
1458         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1459         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1460                                         GFP_NOFS);
1461         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1462                 ret = -ENOMEM;
1463                 goto fail;
1464         }
1465
1466         writers = btrfs_alloc_subvolume_writers();
1467         if (IS_ERR(writers)) {
1468                 ret = PTR_ERR(writers);
1469                 goto fail;
1470         }
1471         root->subv_writers = writers;
1472
1473         btrfs_init_free_ino_ctl(root);
1474         spin_lock_init(&root->ino_cache_lock);
1475         init_waitqueue_head(&root->ino_cache_wait);
1476
1477         ret = get_anon_bdev(&root->anon_dev);
1478         if (ret)
1479                 goto fail;
1480
1481         mutex_lock(&root->objectid_mutex);
1482         ret = btrfs_find_highest_objectid(root,
1483                                         &root->highest_objectid);
1484         if (ret) {
1485                 mutex_unlock(&root->objectid_mutex);
1486                 goto fail;
1487         }
1488
1489         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1490
1491         mutex_unlock(&root->objectid_mutex);
1492
1493         return 0;
1494 fail:
1495         /* the caller is responsible to call free_fs_root */
1496         return ret;
1497 }
1498
1499 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1500                                         u64 root_id)
1501 {
1502         struct btrfs_root *root;
1503
1504         spin_lock(&fs_info->fs_roots_radix_lock);
1505         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1506                                  (unsigned long)root_id);
1507         spin_unlock(&fs_info->fs_roots_radix_lock);
1508         return root;
1509 }
1510
1511 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1512                          struct btrfs_root *root)
1513 {
1514         int ret;
1515
1516         ret = radix_tree_preload(GFP_NOFS);
1517         if (ret)
1518                 return ret;
1519
1520         spin_lock(&fs_info->fs_roots_radix_lock);
1521         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1522                                 (unsigned long)root->root_key.objectid,
1523                                 root);
1524         if (ret == 0)
1525                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1526         spin_unlock(&fs_info->fs_roots_radix_lock);
1527         radix_tree_preload_end();
1528
1529         return ret;
1530 }
1531
1532 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1533                                      struct btrfs_key *location,
1534                                      bool check_ref)
1535 {
1536         struct btrfs_root *root;
1537         struct btrfs_path *path;
1538         struct btrfs_key key;
1539         int ret;
1540
1541         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1542                 return fs_info->tree_root;
1543         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1544                 return fs_info->extent_root;
1545         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1546                 return fs_info->chunk_root;
1547         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1548                 return fs_info->dev_root;
1549         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1550                 return fs_info->csum_root;
1551         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1552                 return fs_info->quota_root ? fs_info->quota_root :
1553                                              ERR_PTR(-ENOENT);
1554         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1555                 return fs_info->uuid_root ? fs_info->uuid_root :
1556                                             ERR_PTR(-ENOENT);
1557         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1558                 return fs_info->free_space_root ? fs_info->free_space_root :
1559                                                   ERR_PTR(-ENOENT);
1560 again:
1561         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1562         if (root) {
1563                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1564                         return ERR_PTR(-ENOENT);
1565                 return root;
1566         }
1567
1568         root = btrfs_read_fs_root(fs_info->tree_root, location);
1569         if (IS_ERR(root))
1570                 return root;
1571
1572         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1573                 ret = -ENOENT;
1574                 goto fail;
1575         }
1576
1577         ret = btrfs_init_fs_root(root);
1578         if (ret)
1579                 goto fail;
1580
1581         path = btrfs_alloc_path();
1582         if (!path) {
1583                 ret = -ENOMEM;
1584                 goto fail;
1585         }
1586         key.objectid = BTRFS_ORPHAN_OBJECTID;
1587         key.type = BTRFS_ORPHAN_ITEM_KEY;
1588         key.offset = location->objectid;
1589
1590         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1591         btrfs_free_path(path);
1592         if (ret < 0)
1593                 goto fail;
1594         if (ret == 0)
1595                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1596
1597         ret = btrfs_insert_fs_root(fs_info, root);
1598         if (ret) {
1599                 if (ret == -EEXIST) {
1600                         free_fs_root(root);
1601                         goto again;
1602                 }
1603                 goto fail;
1604         }
1605         return root;
1606 fail:
1607         free_fs_root(root);
1608         return ERR_PTR(ret);
1609 }
1610
1611 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1612 {
1613         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1614         int ret = 0;
1615         struct btrfs_device *device;
1616         struct backing_dev_info *bdi;
1617
1618         rcu_read_lock();
1619         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1620                 if (!device->bdev)
1621                         continue;
1622                 bdi = device->bdev->bd_bdi;
1623                 if (bdi_congested(bdi, bdi_bits)) {
1624                         ret = 1;
1625                         break;
1626                 }
1627         }
1628         rcu_read_unlock();
1629         return ret;
1630 }
1631
1632 /*
1633  * called by the kthread helper functions to finally call the bio end_io
1634  * functions.  This is where read checksum verification actually happens
1635  */
1636 static void end_workqueue_fn(struct btrfs_work *work)
1637 {
1638         struct bio *bio;
1639         struct btrfs_end_io_wq *end_io_wq;
1640
1641         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1642         bio = end_io_wq->bio;
1643
1644         bio->bi_status = end_io_wq->status;
1645         bio->bi_private = end_io_wq->private;
1646         bio->bi_end_io = end_io_wq->end_io;
1647         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1648         bio_endio(bio);
1649 }
1650
1651 static int cleaner_kthread(void *arg)
1652 {
1653         struct btrfs_root *root = arg;
1654         struct btrfs_fs_info *fs_info = root->fs_info;
1655         int again;
1656         struct btrfs_trans_handle *trans;
1657
1658         do {
1659                 again = 0;
1660
1661                 /* Make the cleaner go to sleep early. */
1662                 if (btrfs_need_cleaner_sleep(fs_info))
1663                         goto sleep;
1664
1665                 /*
1666                  * Do not do anything if we might cause open_ctree() to block
1667                  * before we have finished mounting the filesystem.
1668                  */
1669                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1670                         goto sleep;
1671
1672                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1673                         goto sleep;
1674
1675                 /*
1676                  * Avoid the problem that we change the status of the fs
1677                  * during the above check and trylock.
1678                  */
1679                 if (btrfs_need_cleaner_sleep(fs_info)) {
1680                         mutex_unlock(&fs_info->cleaner_mutex);
1681                         goto sleep;
1682                 }
1683
1684                 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
1685                 btrfs_run_delayed_iputs(fs_info);
1686                 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
1687
1688                 again = btrfs_clean_one_deleted_snapshot(root);
1689                 mutex_unlock(&fs_info->cleaner_mutex);
1690
1691                 /*
1692                  * The defragger has dealt with the R/O remount and umount,
1693                  * needn't do anything special here.
1694                  */
1695                 btrfs_run_defrag_inodes(fs_info);
1696
1697                 /*
1698                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1699                  * with relocation (btrfs_relocate_chunk) and relocation
1700                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1701                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1702                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1703                  * unused block groups.
1704                  */
1705                 btrfs_delete_unused_bgs(fs_info);
1706 sleep:
1707                 if (!again) {
1708                         set_current_state(TASK_INTERRUPTIBLE);
1709                         if (!kthread_should_stop())
1710                                 schedule();
1711                         __set_current_state(TASK_RUNNING);
1712                 }
1713         } while (!kthread_should_stop());
1714
1715         /*
1716          * Transaction kthread is stopped before us and wakes us up.
1717          * However we might have started a new transaction and COWed some
1718          * tree blocks when deleting unused block groups for example. So
1719          * make sure we commit the transaction we started to have a clean
1720          * shutdown when evicting the btree inode - if it has dirty pages
1721          * when we do the final iput() on it, eviction will trigger a
1722          * writeback for it which will fail with null pointer dereferences
1723          * since work queues and other resources were already released and
1724          * destroyed by the time the iput/eviction/writeback is made.
1725          */
1726         trans = btrfs_attach_transaction(root);
1727         if (IS_ERR(trans)) {
1728                 if (PTR_ERR(trans) != -ENOENT)
1729                         btrfs_err(fs_info,
1730                                   "cleaner transaction attach returned %ld",
1731                                   PTR_ERR(trans));
1732         } else {
1733                 int ret;
1734
1735                 ret = btrfs_commit_transaction(trans);
1736                 if (ret)
1737                         btrfs_err(fs_info,
1738                                   "cleaner open transaction commit returned %d",
1739                                   ret);
1740         }
1741
1742         return 0;
1743 }
1744
1745 static int transaction_kthread(void *arg)
1746 {
1747         struct btrfs_root *root = arg;
1748         struct btrfs_fs_info *fs_info = root->fs_info;
1749         struct btrfs_trans_handle *trans;
1750         struct btrfs_transaction *cur;
1751         u64 transid;
1752         unsigned long now;
1753         unsigned long delay;
1754         bool cannot_commit;
1755
1756         do {
1757                 cannot_commit = false;
1758                 delay = HZ * fs_info->commit_interval;
1759                 mutex_lock(&fs_info->transaction_kthread_mutex);
1760
1761                 spin_lock(&fs_info->trans_lock);
1762                 cur = fs_info->running_transaction;
1763                 if (!cur) {
1764                         spin_unlock(&fs_info->trans_lock);
1765                         goto sleep;
1766                 }
1767
1768                 now = get_seconds();
1769                 if (cur->state < TRANS_STATE_BLOCKED &&
1770                     (now < cur->start_time ||
1771                      now - cur->start_time < fs_info->commit_interval)) {
1772                         spin_unlock(&fs_info->trans_lock);
1773                         delay = HZ * 5;
1774                         goto sleep;
1775                 }
1776                 transid = cur->transid;
1777                 spin_unlock(&fs_info->trans_lock);
1778
1779                 /* If the file system is aborted, this will always fail. */
1780                 trans = btrfs_attach_transaction(root);
1781                 if (IS_ERR(trans)) {
1782                         if (PTR_ERR(trans) != -ENOENT)
1783                                 cannot_commit = true;
1784                         goto sleep;
1785                 }
1786                 if (transid == trans->transid) {
1787                         btrfs_commit_transaction(trans);
1788                 } else {
1789                         btrfs_end_transaction(trans);
1790                 }
1791 sleep:
1792                 wake_up_process(fs_info->cleaner_kthread);
1793                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1794
1795                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1796                                       &fs_info->fs_state)))
1797                         btrfs_cleanup_transaction(fs_info);
1798                 if (!kthread_should_stop() &&
1799                                 (!btrfs_transaction_blocked(fs_info) ||
1800                                  cannot_commit))
1801                         schedule_timeout_interruptible(delay);
1802         } while (!kthread_should_stop());
1803         return 0;
1804 }
1805
1806 /*
1807  * this will find the highest generation in the array of
1808  * root backups.  The index of the highest array is returned,
1809  * or -1 if we can't find anything.
1810  *
1811  * We check to make sure the array is valid by comparing the
1812  * generation of the latest  root in the array with the generation
1813  * in the super block.  If they don't match we pitch it.
1814  */
1815 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1816 {
1817         u64 cur;
1818         int newest_index = -1;
1819         struct btrfs_root_backup *root_backup;
1820         int i;
1821
1822         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1823                 root_backup = info->super_copy->super_roots + i;
1824                 cur = btrfs_backup_tree_root_gen(root_backup);
1825                 if (cur == newest_gen)
1826                         newest_index = i;
1827         }
1828
1829         /* check to see if we actually wrapped around */
1830         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1831                 root_backup = info->super_copy->super_roots;
1832                 cur = btrfs_backup_tree_root_gen(root_backup);
1833                 if (cur == newest_gen)
1834                         newest_index = 0;
1835         }
1836         return newest_index;
1837 }
1838
1839
1840 /*
1841  * find the oldest backup so we know where to store new entries
1842  * in the backup array.  This will set the backup_root_index
1843  * field in the fs_info struct
1844  */
1845 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1846                                      u64 newest_gen)
1847 {
1848         int newest_index = -1;
1849
1850         newest_index = find_newest_super_backup(info, newest_gen);
1851         /* if there was garbage in there, just move along */
1852         if (newest_index == -1) {
1853                 info->backup_root_index = 0;
1854         } else {
1855                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1856         }
1857 }
1858
1859 /*
1860  * copy all the root pointers into the super backup array.
1861  * this will bump the backup pointer by one when it is
1862  * done
1863  */
1864 static void backup_super_roots(struct btrfs_fs_info *info)
1865 {
1866         int next_backup;
1867         struct btrfs_root_backup *root_backup;
1868         int last_backup;
1869
1870         next_backup = info->backup_root_index;
1871         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1872                 BTRFS_NUM_BACKUP_ROOTS;
1873
1874         /*
1875          * just overwrite the last backup if we're at the same generation
1876          * this happens only at umount
1877          */
1878         root_backup = info->super_for_commit->super_roots + last_backup;
1879         if (btrfs_backup_tree_root_gen(root_backup) ==
1880             btrfs_header_generation(info->tree_root->node))
1881                 next_backup = last_backup;
1882
1883         root_backup = info->super_for_commit->super_roots + next_backup;
1884
1885         /*
1886          * make sure all of our padding and empty slots get zero filled
1887          * regardless of which ones we use today
1888          */
1889         memset(root_backup, 0, sizeof(*root_backup));
1890
1891         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1892
1893         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1894         btrfs_set_backup_tree_root_gen(root_backup,
1895                                btrfs_header_generation(info->tree_root->node));
1896
1897         btrfs_set_backup_tree_root_level(root_backup,
1898                                btrfs_header_level(info->tree_root->node));
1899
1900         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1901         btrfs_set_backup_chunk_root_gen(root_backup,
1902                                btrfs_header_generation(info->chunk_root->node));
1903         btrfs_set_backup_chunk_root_level(root_backup,
1904                                btrfs_header_level(info->chunk_root->node));
1905
1906         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1907         btrfs_set_backup_extent_root_gen(root_backup,
1908                                btrfs_header_generation(info->extent_root->node));
1909         btrfs_set_backup_extent_root_level(root_backup,
1910                                btrfs_header_level(info->extent_root->node));
1911
1912         /*
1913          * we might commit during log recovery, which happens before we set
1914          * the fs_root.  Make sure it is valid before we fill it in.
1915          */
1916         if (info->fs_root && info->fs_root->node) {
1917                 btrfs_set_backup_fs_root(root_backup,
1918                                          info->fs_root->node->start);
1919                 btrfs_set_backup_fs_root_gen(root_backup,
1920                                btrfs_header_generation(info->fs_root->node));
1921                 btrfs_set_backup_fs_root_level(root_backup,
1922                                btrfs_header_level(info->fs_root->node));
1923         }
1924
1925         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1926         btrfs_set_backup_dev_root_gen(root_backup,
1927                                btrfs_header_generation(info->dev_root->node));
1928         btrfs_set_backup_dev_root_level(root_backup,
1929                                        btrfs_header_level(info->dev_root->node));
1930
1931         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1932         btrfs_set_backup_csum_root_gen(root_backup,
1933                                btrfs_header_generation(info->csum_root->node));
1934         btrfs_set_backup_csum_root_level(root_backup,
1935                                btrfs_header_level(info->csum_root->node));
1936
1937         btrfs_set_backup_total_bytes(root_backup,
1938                              btrfs_super_total_bytes(info->super_copy));
1939         btrfs_set_backup_bytes_used(root_backup,
1940                              btrfs_super_bytes_used(info->super_copy));
1941         btrfs_set_backup_num_devices(root_backup,
1942                              btrfs_super_num_devices(info->super_copy));
1943
1944         /*
1945          * if we don't copy this out to the super_copy, it won't get remembered
1946          * for the next commit
1947          */
1948         memcpy(&info->super_copy->super_roots,
1949                &info->super_for_commit->super_roots,
1950                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1951 }
1952
1953 /*
1954  * this copies info out of the root backup array and back into
1955  * the in-memory super block.  It is meant to help iterate through
1956  * the array, so you send it the number of backups you've already
1957  * tried and the last backup index you used.
1958  *
1959  * this returns -1 when it has tried all the backups
1960  */
1961 static noinline int next_root_backup(struct btrfs_fs_info *info,
1962                                      struct btrfs_super_block *super,
1963                                      int *num_backups_tried, int *backup_index)
1964 {
1965         struct btrfs_root_backup *root_backup;
1966         int newest = *backup_index;
1967
1968         if (*num_backups_tried == 0) {
1969                 u64 gen = btrfs_super_generation(super);
1970
1971                 newest = find_newest_super_backup(info, gen);
1972                 if (newest == -1)
1973                         return -1;
1974
1975                 *backup_index = newest;
1976                 *num_backups_tried = 1;
1977         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1978                 /* we've tried all the backups, all done */
1979                 return -1;
1980         } else {
1981                 /* jump to the next oldest backup */
1982                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1983                         BTRFS_NUM_BACKUP_ROOTS;
1984                 *backup_index = newest;
1985                 *num_backups_tried += 1;
1986         }
1987         root_backup = super->super_roots + newest;
1988
1989         btrfs_set_super_generation(super,
1990                                    btrfs_backup_tree_root_gen(root_backup));
1991         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1992         btrfs_set_super_root_level(super,
1993                                    btrfs_backup_tree_root_level(root_backup));
1994         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1995
1996         /*
1997          * fixme: the total bytes and num_devices need to match or we should
1998          * need a fsck
1999          */
2000         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2001         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2002         return 0;
2003 }
2004
2005 /* helper to cleanup workers */
2006 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2007 {
2008         btrfs_destroy_workqueue(fs_info->fixup_workers);
2009         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2010         btrfs_destroy_workqueue(fs_info->workers);
2011         btrfs_destroy_workqueue(fs_info->endio_workers);
2012         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2013         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2014         btrfs_destroy_workqueue(fs_info->rmw_workers);
2015         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2016         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2017         btrfs_destroy_workqueue(fs_info->submit_workers);
2018         btrfs_destroy_workqueue(fs_info->delayed_workers);
2019         btrfs_destroy_workqueue(fs_info->caching_workers);
2020         btrfs_destroy_workqueue(fs_info->readahead_workers);
2021         btrfs_destroy_workqueue(fs_info->flush_workers);
2022         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2023         btrfs_destroy_workqueue(fs_info->extent_workers);
2024         /*
2025          * Now that all other work queues are destroyed, we can safely destroy
2026          * the queues used for metadata I/O, since tasks from those other work
2027          * queues can do metadata I/O operations.
2028          */
2029         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2030         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2031 }
2032
2033 static void free_root_extent_buffers(struct btrfs_root *root)
2034 {
2035         if (root) {
2036                 free_extent_buffer(root->node);
2037                 free_extent_buffer(root->commit_root);
2038                 root->node = NULL;
2039                 root->commit_root = NULL;
2040         }
2041 }
2042
2043 /* helper to cleanup tree roots */
2044 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2045 {
2046         free_root_extent_buffers(info->tree_root);
2047
2048         free_root_extent_buffers(info->dev_root);
2049         free_root_extent_buffers(info->extent_root);
2050         free_root_extent_buffers(info->csum_root);
2051         free_root_extent_buffers(info->quota_root);
2052         free_root_extent_buffers(info->uuid_root);
2053         if (chunk_root)
2054                 free_root_extent_buffers(info->chunk_root);
2055         free_root_extent_buffers(info->free_space_root);
2056 }
2057
2058 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2059 {
2060         int ret;
2061         struct btrfs_root *gang[8];
2062         int i;
2063
2064         while (!list_empty(&fs_info->dead_roots)) {
2065                 gang[0] = list_entry(fs_info->dead_roots.next,
2066                                      struct btrfs_root, root_list);
2067                 list_del(&gang[0]->root_list);
2068
2069                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2070                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2071                 } else {
2072                         free_extent_buffer(gang[0]->node);
2073                         free_extent_buffer(gang[0]->commit_root);
2074                         btrfs_put_fs_root(gang[0]);
2075                 }
2076         }
2077
2078         while (1) {
2079                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2080                                              (void **)gang, 0,
2081                                              ARRAY_SIZE(gang));
2082                 if (!ret)
2083                         break;
2084                 for (i = 0; i < ret; i++)
2085                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2086         }
2087
2088         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2089                 btrfs_free_log_root_tree(NULL, fs_info);
2090                 btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
2091         }
2092 }
2093
2094 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2095 {
2096         mutex_init(&fs_info->scrub_lock);
2097         atomic_set(&fs_info->scrubs_running, 0);
2098         atomic_set(&fs_info->scrub_pause_req, 0);
2099         atomic_set(&fs_info->scrubs_paused, 0);
2100         atomic_set(&fs_info->scrub_cancel_req, 0);
2101         init_waitqueue_head(&fs_info->scrub_pause_wait);
2102         fs_info->scrub_workers_refcnt = 0;
2103 }
2104
2105 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2106 {
2107         spin_lock_init(&fs_info->balance_lock);
2108         mutex_init(&fs_info->balance_mutex);
2109         atomic_set(&fs_info->balance_running, 0);
2110         atomic_set(&fs_info->balance_pause_req, 0);
2111         atomic_set(&fs_info->balance_cancel_req, 0);
2112         fs_info->balance_ctl = NULL;
2113         init_waitqueue_head(&fs_info->balance_wait_q);
2114 }
2115
2116 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2117 {
2118         struct inode *inode = fs_info->btree_inode;
2119
2120         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2121         set_nlink(inode, 1);
2122         /*
2123          * we set the i_size on the btree inode to the max possible int.
2124          * the real end of the address space is determined by all of
2125          * the devices in the system
2126          */
2127         inode->i_size = OFFSET_MAX;
2128         inode->i_mapping->a_ops = &btree_aops;
2129
2130         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2131         extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode);
2132         BTRFS_I(inode)->io_tree.track_uptodate = 0;
2133         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2134
2135         BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
2136
2137         BTRFS_I(inode)->root = fs_info->tree_root;
2138         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2139         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2140         btrfs_insert_inode_hash(inode);
2141 }
2142
2143 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2144 {
2145         fs_info->dev_replace.lock_owner = 0;
2146         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2147         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2148         rwlock_init(&fs_info->dev_replace.lock);
2149         atomic_set(&fs_info->dev_replace.read_locks, 0);
2150         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2151         init_waitqueue_head(&fs_info->replace_wait);
2152         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2153 }
2154
2155 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2156 {
2157         spin_lock_init(&fs_info->qgroup_lock);
2158         mutex_init(&fs_info->qgroup_ioctl_lock);
2159         fs_info->qgroup_tree = RB_ROOT;
2160         fs_info->qgroup_op_tree = RB_ROOT;
2161         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2162         fs_info->qgroup_seq = 1;
2163         fs_info->qgroup_ulist = NULL;
2164         fs_info->qgroup_rescan_running = false;
2165         mutex_init(&fs_info->qgroup_rescan_lock);
2166 }
2167
2168 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2169                 struct btrfs_fs_devices *fs_devices)
2170 {
2171         u32 max_active = fs_info->thread_pool_size;
2172         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2173
2174         fs_info->workers =
2175                 btrfs_alloc_workqueue(fs_info, "worker",
2176                                       flags | WQ_HIGHPRI, max_active, 16);
2177
2178         fs_info->delalloc_workers =
2179                 btrfs_alloc_workqueue(fs_info, "delalloc",
2180                                       flags, max_active, 2);
2181
2182         fs_info->flush_workers =
2183                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2184                                       flags, max_active, 0);
2185
2186         fs_info->caching_workers =
2187                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2188
2189         /*
2190          * a higher idle thresh on the submit workers makes it much more
2191          * likely that bios will be send down in a sane order to the
2192          * devices
2193          */
2194         fs_info->submit_workers =
2195                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2196                                       min_t(u64, fs_devices->num_devices,
2197                                             max_active), 64);
2198
2199         fs_info->fixup_workers =
2200                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2201
2202         /*
2203          * endios are largely parallel and should have a very
2204          * low idle thresh
2205          */
2206         fs_info->endio_workers =
2207                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2208         fs_info->endio_meta_workers =
2209                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2210                                       max_active, 4);
2211         fs_info->endio_meta_write_workers =
2212                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2213                                       max_active, 2);
2214         fs_info->endio_raid56_workers =
2215                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2216                                       max_active, 4);
2217         fs_info->endio_repair_workers =
2218                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2219         fs_info->rmw_workers =
2220                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2221         fs_info->endio_write_workers =
2222                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2223                                       max_active, 2);
2224         fs_info->endio_freespace_worker =
2225                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2226                                       max_active, 0);
2227         fs_info->delayed_workers =
2228                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2229                                       max_active, 0);
2230         fs_info->readahead_workers =
2231                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2232                                       max_active, 2);
2233         fs_info->qgroup_rescan_workers =
2234                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2235         fs_info->extent_workers =
2236                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2237                                       min_t(u64, fs_devices->num_devices,
2238                                             max_active), 8);
2239
2240         if (!(fs_info->workers && fs_info->delalloc_workers &&
2241               fs_info->submit_workers && fs_info->flush_workers &&
2242               fs_info->endio_workers && fs_info->endio_meta_workers &&
2243               fs_info->endio_meta_write_workers &&
2244               fs_info->endio_repair_workers &&
2245               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2246               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2247               fs_info->caching_workers && fs_info->readahead_workers &&
2248               fs_info->fixup_workers && fs_info->delayed_workers &&
2249               fs_info->extent_workers &&
2250               fs_info->qgroup_rescan_workers)) {
2251                 return -ENOMEM;
2252         }
2253
2254         return 0;
2255 }
2256
2257 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2258                             struct btrfs_fs_devices *fs_devices)
2259 {
2260         int ret;
2261         struct btrfs_root *log_tree_root;
2262         struct btrfs_super_block *disk_super = fs_info->super_copy;
2263         u64 bytenr = btrfs_super_log_root(disk_super);
2264
2265         if (fs_devices->rw_devices == 0) {
2266                 btrfs_warn(fs_info, "log replay required on RO media");
2267                 return -EIO;
2268         }
2269
2270         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2271         if (!log_tree_root)
2272                 return -ENOMEM;
2273
2274         __setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2275
2276         log_tree_root->node = read_tree_block(fs_info, bytenr,
2277                                               fs_info->generation + 1);
2278         if (IS_ERR(log_tree_root->node)) {
2279                 btrfs_warn(fs_info, "failed to read log tree");
2280                 ret = PTR_ERR(log_tree_root->node);
2281                 kfree(log_tree_root);
2282                 return ret;
2283         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2284                 btrfs_err(fs_info, "failed to read log tree");
2285                 free_extent_buffer(log_tree_root->node);
2286                 kfree(log_tree_root);
2287                 return -EIO;
2288         }
2289         /* returns with log_tree_root freed on success */
2290         ret = btrfs_recover_log_trees(log_tree_root);
2291         if (ret) {
2292                 btrfs_handle_fs_error(fs_info, ret,
2293                                       "Failed to recover log tree");
2294                 free_extent_buffer(log_tree_root->node);
2295                 kfree(log_tree_root);
2296                 return ret;
2297         }
2298
2299         if (sb_rdonly(fs_info->sb)) {
2300                 ret = btrfs_commit_super(fs_info);
2301                 if (ret)
2302                         return ret;
2303         }
2304
2305         return 0;
2306 }
2307
2308 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2309 {
2310         struct btrfs_root *tree_root = fs_info->tree_root;
2311         struct btrfs_root *root;
2312         struct btrfs_key location;
2313         int ret;
2314
2315         BUG_ON(!fs_info->tree_root);
2316
2317         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2318         location.type = BTRFS_ROOT_ITEM_KEY;
2319         location.offset = 0;
2320
2321         root = btrfs_read_tree_root(tree_root, &location);
2322         if (IS_ERR(root))
2323                 return PTR_ERR(root);
2324         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2325         fs_info->extent_root = root;
2326
2327         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2328         root = btrfs_read_tree_root(tree_root, &location);
2329         if (IS_ERR(root))
2330                 return PTR_ERR(root);
2331         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2332         fs_info->dev_root = root;
2333         btrfs_init_devices_late(fs_info);
2334
2335         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2336         root = btrfs_read_tree_root(tree_root, &location);
2337         if (IS_ERR(root))
2338                 return PTR_ERR(root);
2339         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2340         fs_info->csum_root = root;
2341
2342         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2343         root = btrfs_read_tree_root(tree_root, &location);
2344         if (!IS_ERR(root)) {
2345                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2346                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2347                 fs_info->quota_root = root;
2348         }
2349
2350         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2351         root = btrfs_read_tree_root(tree_root, &location);
2352         if (IS_ERR(root)) {
2353                 ret = PTR_ERR(root);
2354                 if (ret != -ENOENT)
2355                         return ret;
2356         } else {
2357                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2358                 fs_info->uuid_root = root;
2359         }
2360
2361         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2362                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2363                 root = btrfs_read_tree_root(tree_root, &location);
2364                 if (IS_ERR(root))
2365                         return PTR_ERR(root);
2366                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2367                 fs_info->free_space_root = root;
2368         }
2369
2370         return 0;
2371 }
2372
2373 int open_ctree(struct super_block *sb,
2374                struct btrfs_fs_devices *fs_devices,
2375                char *options)
2376 {
2377         u32 sectorsize;
2378         u32 nodesize;
2379         u32 stripesize;
2380         u64 generation;
2381         u64 features;
2382         struct btrfs_key location;
2383         struct buffer_head *bh;
2384         struct btrfs_super_block *disk_super;
2385         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2386         struct btrfs_root *tree_root;
2387         struct btrfs_root *chunk_root;
2388         int ret;
2389         int err = -EINVAL;
2390         int num_backups_tried = 0;
2391         int backup_index = 0;
2392         u32 max_active;
2393         int clear_free_space_tree = 0;
2394
2395         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2396         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2397         if (!tree_root || !chunk_root) {
2398                 err = -ENOMEM;
2399                 goto fail;
2400         }
2401
2402         ret = init_srcu_struct(&fs_info->subvol_srcu);
2403         if (ret) {
2404                 err = ret;
2405                 goto fail;
2406         }
2407
2408         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2409         if (ret) {
2410                 err = ret;
2411                 goto fail_srcu;
2412         }
2413         fs_info->dirty_metadata_batch = PAGE_SIZE *
2414                                         (1 + ilog2(nr_cpu_ids));
2415
2416         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2417         if (ret) {
2418                 err = ret;
2419                 goto fail_dirty_metadata_bytes;
2420         }
2421
2422         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2423         if (ret) {
2424                 err = ret;
2425                 goto fail_delalloc_bytes;
2426         }
2427
2428         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2429         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2430         INIT_LIST_HEAD(&fs_info->trans_list);
2431         INIT_LIST_HEAD(&fs_info->dead_roots);
2432         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2433         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2434         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2435         spin_lock_init(&fs_info->delalloc_root_lock);
2436         spin_lock_init(&fs_info->trans_lock);
2437         spin_lock_init(&fs_info->fs_roots_radix_lock);
2438         spin_lock_init(&fs_info->delayed_iput_lock);
2439         spin_lock_init(&fs_info->defrag_inodes_lock);
2440         spin_lock_init(&fs_info->tree_mod_seq_lock);
2441         spin_lock_init(&fs_info->super_lock);
2442         spin_lock_init(&fs_info->qgroup_op_lock);
2443         spin_lock_init(&fs_info->buffer_lock);
2444         spin_lock_init(&fs_info->unused_bgs_lock);
2445         rwlock_init(&fs_info->tree_mod_log_lock);
2446         mutex_init(&fs_info->unused_bg_unpin_mutex);
2447         mutex_init(&fs_info->delete_unused_bgs_mutex);
2448         mutex_init(&fs_info->reloc_mutex);
2449         mutex_init(&fs_info->delalloc_root_mutex);
2450         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2451         seqlock_init(&fs_info->profiles_lock);
2452
2453         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2454         INIT_LIST_HEAD(&fs_info->space_info);
2455         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2456         INIT_LIST_HEAD(&fs_info->unused_bgs);
2457         btrfs_mapping_init(&fs_info->mapping_tree);
2458         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2459                              BTRFS_BLOCK_RSV_GLOBAL);
2460         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2461         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2462         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2463         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2464                              BTRFS_BLOCK_RSV_DELOPS);
2465         atomic_set(&fs_info->async_delalloc_pages, 0);
2466         atomic_set(&fs_info->defrag_running, 0);
2467         atomic_set(&fs_info->qgroup_op_seq, 0);
2468         atomic_set(&fs_info->reada_works_cnt, 0);
2469         atomic64_set(&fs_info->tree_mod_seq, 0);
2470         fs_info->sb = sb;
2471         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2472         fs_info->metadata_ratio = 0;
2473         fs_info->defrag_inodes = RB_ROOT;
2474         atomic64_set(&fs_info->free_chunk_space, 0);
2475         fs_info->tree_mod_log = RB_ROOT;
2476         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2477         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2478         /* readahead state */
2479         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2480         spin_lock_init(&fs_info->reada_lock);
2481         btrfs_init_ref_verify(fs_info);
2482
2483         fs_info->thread_pool_size = min_t(unsigned long,
2484                                           num_online_cpus() + 2, 8);
2485
2486         INIT_LIST_HEAD(&fs_info->ordered_roots);
2487         spin_lock_init(&fs_info->ordered_root_lock);
2488
2489         fs_info->btree_inode = new_inode(sb);
2490         if (!fs_info->btree_inode) {
2491                 err = -ENOMEM;
2492                 goto fail_bio_counter;
2493         }
2494         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2495
2496         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2497                                         GFP_KERNEL);
2498         if (!fs_info->delayed_root) {
2499                 err = -ENOMEM;
2500                 goto fail_iput;
2501         }
2502         btrfs_init_delayed_root(fs_info->delayed_root);
2503
2504         btrfs_init_scrub(fs_info);
2505 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2506         fs_info->check_integrity_print_mask = 0;
2507 #endif
2508         btrfs_init_balance(fs_info);
2509         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2510
2511         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2512         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
2513
2514         btrfs_init_btree_inode(fs_info);
2515
2516         spin_lock_init(&fs_info->block_group_cache_lock);
2517         fs_info->block_group_cache_tree = RB_ROOT;
2518         fs_info->first_logical_byte = (u64)-1;
2519
2520         extent_io_tree_init(&fs_info->freed_extents[0], NULL);
2521         extent_io_tree_init(&fs_info->freed_extents[1], NULL);
2522         fs_info->pinned_extents = &fs_info->freed_extents[0];
2523         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2524
2525         mutex_init(&fs_info->ordered_operations_mutex);
2526         mutex_init(&fs_info->tree_log_mutex);
2527         mutex_init(&fs_info->chunk_mutex);
2528         mutex_init(&fs_info->transaction_kthread_mutex);
2529         mutex_init(&fs_info->cleaner_mutex);
2530         mutex_init(&fs_info->volume_mutex);
2531         mutex_init(&fs_info->ro_block_group_mutex);
2532         init_rwsem(&fs_info->commit_root_sem);
2533         init_rwsem(&fs_info->cleanup_work_sem);
2534         init_rwsem(&fs_info->subvol_sem);
2535         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2536
2537         btrfs_init_dev_replace_locks(fs_info);
2538         btrfs_init_qgroup(fs_info);
2539
2540         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2541         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2542
2543         init_waitqueue_head(&fs_info->transaction_throttle);
2544         init_waitqueue_head(&fs_info->transaction_wait);
2545         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2546         init_waitqueue_head(&fs_info->async_submit_wait);
2547
2548         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2549
2550         /* Usable values until the real ones are cached from the superblock */
2551         fs_info->nodesize = 4096;
2552         fs_info->sectorsize = 4096;
2553         fs_info->stripesize = 4096;
2554
2555         ret = btrfs_alloc_stripe_hash_table(fs_info);
2556         if (ret) {
2557                 err = ret;
2558                 goto fail_alloc;
2559         }
2560
2561         __setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
2562
2563         invalidate_bdev(fs_devices->latest_bdev);
2564
2565         /*
2566          * Read super block and check the signature bytes only
2567          */
2568         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2569         if (IS_ERR(bh)) {
2570                 err = PTR_ERR(bh);
2571                 goto fail_alloc;
2572         }
2573
2574         /*
2575          * We want to check superblock checksum, the type is stored inside.
2576          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2577          */
2578         if (btrfs_check_super_csum(fs_info, bh->b_data)) {
2579                 btrfs_err(fs_info, "superblock checksum mismatch");
2580                 err = -EINVAL;
2581                 brelse(bh);
2582                 goto fail_alloc;
2583         }
2584
2585         /*
2586          * super_copy is zeroed at allocation time and we never touch the
2587          * following bytes up to INFO_SIZE, the checksum is calculated from
2588          * the whole block of INFO_SIZE
2589          */
2590         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2591         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2592                sizeof(*fs_info->super_for_commit));
2593         brelse(bh);
2594
2595         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2596
2597         ret = btrfs_check_super_valid(fs_info);
2598         if (ret) {
2599                 btrfs_err(fs_info, "superblock contains fatal errors");
2600                 err = -EINVAL;
2601                 goto fail_alloc;
2602         }
2603
2604         disk_super = fs_info->super_copy;
2605         if (!btrfs_super_root(disk_super))
2606                 goto fail_alloc;
2607
2608         /* check FS state, whether FS is broken. */
2609         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2610                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2611
2612         /*
2613          * run through our array of backup supers and setup
2614          * our ring pointer to the oldest one
2615          */
2616         generation = btrfs_super_generation(disk_super);
2617         find_oldest_super_backup(fs_info, generation);
2618
2619         /*
2620          * In the long term, we'll store the compression type in the super
2621          * block, and it'll be used for per file compression control.
2622          */
2623         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2624
2625         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
2626         if (ret) {
2627                 err = ret;
2628                 goto fail_alloc;
2629         }
2630
2631         features = btrfs_super_incompat_flags(disk_super) &
2632                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2633         if (features) {
2634                 btrfs_err(fs_info,
2635                     "cannot mount because of unsupported optional features (%llx)",
2636                     features);
2637                 err = -EINVAL;
2638                 goto fail_alloc;
2639         }
2640
2641         features = btrfs_super_incompat_flags(disk_super);
2642         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2643         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
2644                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2645         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
2646                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
2647
2648         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2649                 btrfs_info(fs_info, "has skinny extents");
2650
2651         /*
2652          * flag our filesystem as having big metadata blocks if
2653          * they are bigger than the page size
2654          */
2655         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2656                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2657                         btrfs_info(fs_info,
2658                                 "flagging fs with big metadata feature");
2659                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2660         }
2661
2662         nodesize = btrfs_super_nodesize(disk_super);
2663         sectorsize = btrfs_super_sectorsize(disk_super);
2664         stripesize = sectorsize;
2665         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2666         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2667
2668         /* Cache block sizes */
2669         fs_info->nodesize = nodesize;
2670         fs_info->sectorsize = sectorsize;
2671         fs_info->stripesize = stripesize;
2672
2673         /*
2674          * mixed block groups end up with duplicate but slightly offset
2675          * extent buffers for the same range.  It leads to corruptions
2676          */
2677         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2678             (sectorsize != nodesize)) {
2679                 btrfs_err(fs_info,
2680 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2681                         nodesize, sectorsize);
2682                 goto fail_alloc;
2683         }
2684
2685         /*
2686          * Needn't use the lock because there is no other task which will
2687          * update the flag.
2688          */
2689         btrfs_set_super_incompat_flags(disk_super, features);
2690
2691         features = btrfs_super_compat_ro_flags(disk_super) &
2692                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2693         if (!sb_rdonly(sb) && features) {
2694                 btrfs_err(fs_info,
2695         "cannot mount read-write because of unsupported optional features (%llx)",
2696                        features);
2697                 err = -EINVAL;
2698                 goto fail_alloc;
2699         }
2700
2701         max_active = fs_info->thread_pool_size;
2702
2703         ret = btrfs_init_workqueues(fs_info, fs_devices);
2704         if (ret) {
2705                 err = ret;
2706                 goto fail_sb_buffer;
2707         }
2708
2709         sb->s_bdi->congested_fn = btrfs_congested_fn;
2710         sb->s_bdi->congested_data = fs_info;
2711         sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
2712         sb->s_bdi->ra_pages = VM_MAX_READAHEAD * SZ_1K / PAGE_SIZE;
2713         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
2714         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
2715
2716         sb->s_blocksize = sectorsize;
2717         sb->s_blocksize_bits = blksize_bits(sectorsize);
2718         memcpy(&sb->s_uuid, fs_info->fsid, BTRFS_FSID_SIZE);
2719
2720         mutex_lock(&fs_info->chunk_mutex);
2721         ret = btrfs_read_sys_array(fs_info);
2722         mutex_unlock(&fs_info->chunk_mutex);
2723         if (ret) {
2724                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2725                 goto fail_sb_buffer;
2726         }
2727
2728         generation = btrfs_super_chunk_root_generation(disk_super);
2729
2730         __setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2731
2732         chunk_root->node = read_tree_block(fs_info,
2733                                            btrfs_super_chunk_root(disk_super),
2734                                            generation);
2735         if (IS_ERR(chunk_root->node) ||
2736             !extent_buffer_uptodate(chunk_root->node)) {
2737                 btrfs_err(fs_info, "failed to read chunk root");
2738                 if (!IS_ERR(chunk_root->node))
2739                         free_extent_buffer(chunk_root->node);
2740                 chunk_root->node = NULL;
2741                 goto fail_tree_roots;
2742         }
2743         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2744         chunk_root->commit_root = btrfs_root_node(chunk_root);
2745
2746         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2747            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2748
2749         ret = btrfs_read_chunk_tree(fs_info);
2750         if (ret) {
2751                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
2752                 goto fail_tree_roots;
2753         }
2754
2755         /*
2756          * Keep the devid that is marked to be the target device for the
2757          * device replace procedure
2758          */
2759         btrfs_free_extra_devids(fs_devices, 0);
2760
2761         if (!fs_devices->latest_bdev) {
2762                 btrfs_err(fs_info, "failed to read devices");
2763                 goto fail_tree_roots;
2764         }
2765
2766 retry_root_backup:
2767         generation = btrfs_super_generation(disk_super);
2768
2769         tree_root->node = read_tree_block(fs_info,
2770                                           btrfs_super_root(disk_super),
2771                                           generation);
2772         if (IS_ERR(tree_root->node) ||
2773             !extent_buffer_uptodate(tree_root->node)) {
2774                 btrfs_warn(fs_info, "failed to read tree root");
2775                 if (!IS_ERR(tree_root->node))
2776                         free_extent_buffer(tree_root->node);
2777                 tree_root->node = NULL;
2778                 goto recovery_tree_root;
2779         }
2780
2781         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2782         tree_root->commit_root = btrfs_root_node(tree_root);
2783         btrfs_set_root_refs(&tree_root->root_item, 1);
2784
2785         mutex_lock(&tree_root->objectid_mutex);
2786         ret = btrfs_find_highest_objectid(tree_root,
2787                                         &tree_root->highest_objectid);
2788         if (ret) {
2789                 mutex_unlock(&tree_root->objectid_mutex);
2790                 goto recovery_tree_root;
2791         }
2792
2793         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
2794
2795         mutex_unlock(&tree_root->objectid_mutex);
2796
2797         ret = btrfs_read_roots(fs_info);
2798         if (ret)
2799                 goto recovery_tree_root;
2800
2801         fs_info->generation = generation;
2802         fs_info->last_trans_committed = generation;
2803
2804         ret = btrfs_recover_balance(fs_info);
2805         if (ret) {
2806                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
2807                 goto fail_block_groups;
2808         }
2809
2810         ret = btrfs_init_dev_stats(fs_info);
2811         if (ret) {
2812                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
2813                 goto fail_block_groups;
2814         }
2815
2816         ret = btrfs_init_dev_replace(fs_info);
2817         if (ret) {
2818                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
2819                 goto fail_block_groups;
2820         }
2821
2822         btrfs_free_extra_devids(fs_devices, 1);
2823
2824         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
2825         if (ret) {
2826                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
2827                                 ret);
2828                 goto fail_block_groups;
2829         }
2830
2831         ret = btrfs_sysfs_add_device(fs_devices);
2832         if (ret) {
2833                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
2834                                 ret);
2835                 goto fail_fsdev_sysfs;
2836         }
2837
2838         ret = btrfs_sysfs_add_mounted(fs_info);
2839         if (ret) {
2840                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
2841                 goto fail_fsdev_sysfs;
2842         }
2843
2844         ret = btrfs_init_space_info(fs_info);
2845         if (ret) {
2846                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
2847                 goto fail_sysfs;
2848         }
2849
2850         ret = btrfs_read_block_groups(fs_info);
2851         if (ret) {
2852                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
2853                 goto fail_sysfs;
2854         }
2855
2856         if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
2857                 btrfs_warn(fs_info,
2858                 "writeable mount is not allowed due to too many missing devices");
2859                 goto fail_sysfs;
2860         }
2861
2862         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2863                                                "btrfs-cleaner");
2864         if (IS_ERR(fs_info->cleaner_kthread))
2865                 goto fail_sysfs;
2866
2867         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2868                                                    tree_root,
2869                                                    "btrfs-transaction");
2870         if (IS_ERR(fs_info->transaction_kthread))
2871                 goto fail_cleaner;
2872
2873         if (!btrfs_test_opt(fs_info, NOSSD) &&
2874             !fs_info->fs_devices->rotating) {
2875                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
2876         }
2877
2878         /*
2879          * Mount does not set all options immediately, we can do it now and do
2880          * not have to wait for transaction commit
2881          */
2882         btrfs_apply_pending_changes(fs_info);
2883
2884 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2885         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
2886                 ret = btrfsic_mount(fs_info, fs_devices,
2887                                     btrfs_test_opt(fs_info,
2888                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2889                                     1 : 0,
2890                                     fs_info->check_integrity_print_mask);
2891                 if (ret)
2892                         btrfs_warn(fs_info,
2893                                 "failed to initialize integrity check module: %d",
2894                                 ret);
2895         }
2896 #endif
2897         ret = btrfs_read_qgroup_config(fs_info);
2898         if (ret)
2899                 goto fail_trans_kthread;
2900
2901         if (btrfs_build_ref_tree(fs_info))
2902                 btrfs_err(fs_info, "couldn't build ref tree");
2903
2904         /* do not make disk changes in broken FS or nologreplay is given */
2905         if (btrfs_super_log_root(disk_super) != 0 &&
2906             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
2907                 ret = btrfs_replay_log(fs_info, fs_devices);
2908                 if (ret) {
2909                         err = ret;
2910                         goto fail_qgroup;
2911                 }
2912         }
2913
2914         ret = btrfs_find_orphan_roots(fs_info);
2915         if (ret)
2916                 goto fail_qgroup;
2917
2918         if (!sb_rdonly(sb)) {
2919                 ret = btrfs_cleanup_fs_roots(fs_info);
2920                 if (ret)
2921                         goto fail_qgroup;
2922
2923                 mutex_lock(&fs_info->cleaner_mutex);
2924                 ret = btrfs_recover_relocation(tree_root);
2925                 mutex_unlock(&fs_info->cleaner_mutex);
2926                 if (ret < 0) {
2927                         btrfs_warn(fs_info, "failed to recover relocation: %d",
2928                                         ret);
2929                         err = -EINVAL;
2930                         goto fail_qgroup;
2931                 }
2932         }
2933
2934         location.objectid = BTRFS_FS_TREE_OBJECTID;
2935         location.type = BTRFS_ROOT_ITEM_KEY;
2936         location.offset = 0;
2937
2938         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2939         if (IS_ERR(fs_info->fs_root)) {
2940                 err = PTR_ERR(fs_info->fs_root);
2941                 goto fail_qgroup;
2942         }
2943
2944         if (sb_rdonly(sb))
2945                 return 0;
2946
2947         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
2948             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2949                 clear_free_space_tree = 1;
2950         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
2951                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
2952                 btrfs_warn(fs_info, "free space tree is invalid");
2953                 clear_free_space_tree = 1;
2954         }
2955
2956         if (clear_free_space_tree) {
2957                 btrfs_info(fs_info, "clearing free space tree");
2958                 ret = btrfs_clear_free_space_tree(fs_info);
2959                 if (ret) {
2960                         btrfs_warn(fs_info,
2961                                    "failed to clear free space tree: %d", ret);
2962                         close_ctree(fs_info);
2963                         return ret;
2964                 }
2965         }
2966
2967         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
2968             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2969                 btrfs_info(fs_info, "creating free space tree");
2970                 ret = btrfs_create_free_space_tree(fs_info);
2971                 if (ret) {
2972                         btrfs_warn(fs_info,
2973                                 "failed to create free space tree: %d", ret);
2974                         close_ctree(fs_info);
2975                         return ret;
2976                 }
2977         }
2978
2979         down_read(&fs_info->cleanup_work_sem);
2980         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
2981             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
2982                 up_read(&fs_info->cleanup_work_sem);
2983                 close_ctree(fs_info);
2984                 return ret;
2985         }
2986         up_read(&fs_info->cleanup_work_sem);
2987
2988         ret = btrfs_resume_balance_async(fs_info);
2989         if (ret) {
2990                 btrfs_warn(fs_info, "failed to resume balance: %d", ret);
2991                 close_ctree(fs_info);
2992                 return ret;
2993         }
2994
2995         ret = btrfs_resume_dev_replace_async(fs_info);
2996         if (ret) {
2997                 btrfs_warn(fs_info, "failed to resume device replace: %d", ret);
2998                 close_ctree(fs_info);
2999                 return ret;
3000         }
3001
3002         btrfs_qgroup_rescan_resume(fs_info);
3003
3004         if (!fs_info->uuid_root) {
3005                 btrfs_info(fs_info, "creating UUID tree");
3006                 ret = btrfs_create_uuid_tree(fs_info);
3007                 if (ret) {
3008                         btrfs_warn(fs_info,
3009                                 "failed to create the UUID tree: %d", ret);
3010                         close_ctree(fs_info);
3011                         return ret;
3012                 }
3013         } else if (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3014                    fs_info->generation !=
3015                                 btrfs_super_uuid_tree_generation(disk_super)) {
3016                 btrfs_info(fs_info, "checking UUID tree");
3017                 ret = btrfs_check_uuid_tree(fs_info);
3018                 if (ret) {
3019                         btrfs_warn(fs_info,
3020                                 "failed to check the UUID tree: %d", ret);
3021                         close_ctree(fs_info);
3022                         return ret;
3023                 }
3024         } else {
3025                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3026         }
3027         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3028
3029         /*
3030          * backuproot only affect mount behavior, and if open_ctree succeeded,
3031          * no need to keep the flag
3032          */
3033         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3034
3035         return 0;
3036
3037 fail_qgroup:
3038         btrfs_free_qgroup_config(fs_info);
3039 fail_trans_kthread:
3040         kthread_stop(fs_info->transaction_kthread);
3041         btrfs_cleanup_transaction(fs_info);
3042         btrfs_free_fs_roots(fs_info);
3043 fail_cleaner:
3044         kthread_stop(fs_info->cleaner_kthread);
3045
3046         /*
3047          * make sure we're done with the btree inode before we stop our
3048          * kthreads
3049          */
3050         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3051
3052 fail_sysfs:
3053         btrfs_sysfs_remove_mounted(fs_info);
3054
3055 fail_fsdev_sysfs:
3056         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3057
3058 fail_block_groups:
3059         btrfs_put_block_group_cache(fs_info);
3060
3061 fail_tree_roots:
3062         free_root_pointers(fs_info, 1);
3063         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3064
3065 fail_sb_buffer:
3066         btrfs_stop_all_workers(fs_info);
3067         btrfs_free_block_groups(fs_info);
3068 fail_alloc:
3069 fail_iput:
3070         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3071
3072         iput(fs_info->btree_inode);
3073 fail_bio_counter:
3074         percpu_counter_destroy(&fs_info->bio_counter);
3075 fail_delalloc_bytes:
3076         percpu_counter_destroy(&fs_info->delalloc_bytes);
3077 fail_dirty_metadata_bytes:
3078         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3079 fail_srcu:
3080         cleanup_srcu_struct(&fs_info->subvol_srcu);
3081 fail:
3082         btrfs_free_stripe_hash_table(fs_info);
3083         btrfs_close_devices(fs_info->fs_devices);
3084         return err;
3085
3086 recovery_tree_root:
3087         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
3088                 goto fail_tree_roots;
3089
3090         free_root_pointers(fs_info, 0);
3091
3092         /* don't use the log in recovery mode, it won't be valid */
3093         btrfs_set_super_log_root(disk_super, 0);
3094
3095         /* we can't trust the free space cache either */
3096         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3097
3098         ret = next_root_backup(fs_info, fs_info->super_copy,
3099                                &num_backups_tried, &backup_index);
3100         if (ret == -1)
3101                 goto fail_block_groups;
3102         goto retry_root_backup;
3103 }
3104 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3105
3106 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3107 {
3108         if (uptodate) {
3109                 set_buffer_uptodate(bh);
3110         } else {
3111                 struct btrfs_device *device = (struct btrfs_device *)
3112                         bh->b_private;
3113
3114                 btrfs_warn_rl_in_rcu(device->fs_info,
3115                                 "lost page write due to IO error on %s",
3116                                           rcu_str_deref(device->name));
3117                 /* note, we don't set_buffer_write_io_error because we have
3118                  * our own ways of dealing with the IO errors
3119                  */
3120                 clear_buffer_uptodate(bh);
3121                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3122         }
3123         unlock_buffer(bh);
3124         put_bh(bh);
3125 }
3126
3127 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
3128                         struct buffer_head **bh_ret)
3129 {
3130         struct buffer_head *bh;
3131         struct btrfs_super_block *super;
3132         u64 bytenr;
3133
3134         bytenr = btrfs_sb_offset(copy_num);
3135         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3136                 return -EINVAL;
3137
3138         bh = __bread(bdev, bytenr / BTRFS_BDEV_BLOCKSIZE, BTRFS_SUPER_INFO_SIZE);
3139         /*
3140          * If we fail to read from the underlying devices, as of now
3141          * the best option we have is to mark it EIO.
3142          */
3143         if (!bh)
3144                 return -EIO;
3145
3146         super = (struct btrfs_super_block *)bh->b_data;
3147         if (btrfs_super_bytenr(super) != bytenr ||
3148                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3149                 brelse(bh);
3150                 return -EINVAL;
3151         }
3152
3153         *bh_ret = bh;
3154         return 0;
3155 }
3156
3157
3158 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3159 {
3160         struct buffer_head *bh;
3161         struct buffer_head *latest = NULL;
3162         struct btrfs_super_block *super;
3163         int i;
3164         u64 transid = 0;
3165         int ret = -EINVAL;
3166
3167         /* we would like to check all the supers, but that would make
3168          * a btrfs mount succeed after a mkfs from a different FS.
3169          * So, we need to add a special mount option to scan for
3170          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3171          */
3172         for (i = 0; i < 1; i++) {
3173                 ret = btrfs_read_dev_one_super(bdev, i, &bh);
3174                 if (ret)
3175                         continue;
3176
3177                 super = (struct btrfs_super_block *)bh->b_data;
3178
3179                 if (!latest || btrfs_super_generation(super) > transid) {
3180                         brelse(latest);
3181                         latest = bh;
3182                         transid = btrfs_super_generation(super);
3183                 } else {
3184                         brelse(bh);
3185                 }
3186         }
3187
3188         if (!latest)
3189                 return ERR_PTR(ret);
3190
3191         return latest;
3192 }
3193
3194 /*
3195  * Write superblock @sb to the @device. Do not wait for completion, all the
3196  * buffer heads we write are pinned.
3197  *
3198  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3199  * the expected device size at commit time. Note that max_mirrors must be
3200  * same for write and wait phases.
3201  *
3202  * Return number of errors when buffer head is not found or submission fails.
3203  */
3204 static int write_dev_supers(struct btrfs_device *device,
3205                             struct btrfs_super_block *sb, int max_mirrors)
3206 {
3207         struct buffer_head *bh;
3208         int i;
3209         int ret;
3210         int errors = 0;
3211         u32 crc;
3212         u64 bytenr;
3213         int op_flags;
3214
3215         if (max_mirrors == 0)
3216                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3217
3218         for (i = 0; i < max_mirrors; i++) {
3219                 bytenr = btrfs_sb_offset(i);
3220                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3221                     device->commit_total_bytes)
3222                         break;
3223
3224                 btrfs_set_super_bytenr(sb, bytenr);
3225
3226                 crc = ~(u32)0;
3227                 crc = btrfs_csum_data((const char *)sb + BTRFS_CSUM_SIZE, crc,
3228                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
3229                 btrfs_csum_final(crc, sb->csum);
3230
3231                 /* One reference for us, and we leave it for the caller */
3232                 bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
3233                               BTRFS_SUPER_INFO_SIZE);
3234                 if (!bh) {
3235                         btrfs_err(device->fs_info,
3236                             "couldn't get super buffer head for bytenr %llu",
3237                             bytenr);
3238                         errors++;
3239                         continue;
3240                 }
3241
3242                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3243
3244                 /* one reference for submit_bh */
3245                 get_bh(bh);
3246
3247                 set_buffer_uptodate(bh);
3248                 lock_buffer(bh);
3249                 bh->b_end_io = btrfs_end_buffer_write_sync;
3250                 bh->b_private = device;
3251
3252                 /*
3253                  * we fua the first super.  The others we allow
3254                  * to go down lazy.
3255                  */
3256                 op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
3257                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3258                         op_flags |= REQ_FUA;
3259                 ret = btrfsic_submit_bh(REQ_OP_WRITE, op_flags, bh);
3260                 if (ret)
3261                         errors++;
3262         }
3263         return errors < i ? 0 : -1;
3264 }
3265
3266 /*
3267  * Wait for write completion of superblocks done by write_dev_supers,
3268  * @max_mirrors same for write and wait phases.
3269  *
3270  * Return number of errors when buffer head is not found or not marked up to
3271  * date.
3272  */
3273 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3274 {
3275         struct buffer_head *bh;
3276         int i;
3277         int errors = 0;
3278         bool primary_failed = false;
3279         u64 bytenr;
3280
3281         if (max_mirrors == 0)
3282                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3283
3284         for (i = 0; i < max_mirrors; i++) {
3285                 bytenr = btrfs_sb_offset(i);
3286                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3287                     device->commit_total_bytes)
3288                         break;
3289
3290                 bh = __find_get_block(device->bdev,
3291                                       bytenr / BTRFS_BDEV_BLOCKSIZE,
3292                                       BTRFS_SUPER_INFO_SIZE);
3293                 if (!bh) {
3294                         errors++;
3295                         if (i == 0)
3296                                 primary_failed = true;
3297                         continue;
3298                 }
3299                 wait_on_buffer(bh);
3300                 if (!buffer_uptodate(bh)) {
3301                         errors++;
3302                         if (i == 0)
3303                                 primary_failed = true;
3304                 }
3305
3306                 /* drop our reference */
3307                 brelse(bh);
3308
3309                 /* drop the reference from the writing run */
3310                 brelse(bh);
3311         }
3312
3313         /* log error, force error return */
3314         if (primary_failed) {
3315                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3316                           device->devid);
3317                 return -1;
3318         }
3319
3320         return errors < i ? 0 : -1;
3321 }
3322
3323 /*
3324  * endio for the write_dev_flush, this will wake anyone waiting
3325  * for the barrier when it is done
3326  */
3327 static void btrfs_end_empty_barrier(struct bio *bio)
3328 {
3329         complete(bio->bi_private);
3330 }
3331
3332 /*
3333  * Submit a flush request to the device if it supports it. Error handling is
3334  * done in the waiting counterpart.
3335  */
3336 static void write_dev_flush(struct btrfs_device *device)
3337 {
3338         struct request_queue *q = bdev_get_queue(device->bdev);
3339         struct bio *bio = device->flush_bio;
3340
3341         if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
3342                 return;
3343
3344         bio_reset(bio);
3345         bio->bi_end_io = btrfs_end_empty_barrier;
3346         bio_set_dev(bio, device->bdev);
3347         bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
3348         init_completion(&device->flush_wait);
3349         bio->bi_private = &device->flush_wait;
3350
3351         btrfsic_submit_bio(bio);
3352         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3353 }
3354
3355 /*
3356  * If the flush bio has been submitted by write_dev_flush, wait for it.
3357  */
3358 static blk_status_t wait_dev_flush(struct btrfs_device *device)
3359 {
3360         struct bio *bio = device->flush_bio;
3361
3362         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
3363                 return BLK_STS_OK;
3364
3365         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3366         wait_for_completion_io(&device->flush_wait);
3367
3368         return bio->bi_status;
3369 }
3370
3371 static int check_barrier_error(struct btrfs_fs_info *fs_info)
3372 {
3373         if (!btrfs_check_rw_degradable(fs_info, NULL))
3374                 return -EIO;
3375         return 0;
3376 }
3377
3378 /*
3379  * send an empty flush down to each device in parallel,
3380  * then wait for them
3381  */
3382 static int barrier_all_devices(struct btrfs_fs_info *info)
3383 {
3384         struct list_head *head;
3385         struct btrfs_device *dev;
3386         int errors_wait = 0;
3387         blk_status_t ret;
3388
3389         lockdep_assert_held(&info->fs_devices->device_list_mutex);
3390         /* send down all the barriers */
3391         head = &info->fs_devices->devices;
3392         list_for_each_entry(dev, head, dev_list) {
3393                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3394                         continue;
3395                 if (!dev->bdev)
3396                         continue;
3397                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3398                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3399                         continue;
3400
3401                 write_dev_flush(dev);
3402                 dev->last_flush_error = BLK_STS_OK;
3403         }
3404
3405         /* wait for all the barriers */
3406         list_for_each_entry(dev, head, dev_list) {
3407                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3408                         continue;
3409                 if (!dev->bdev) {
3410                         errors_wait++;
3411                         continue;
3412                 }
3413                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3414                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3415                         continue;
3416
3417                 ret = wait_dev_flush(dev);
3418                 if (ret) {
3419                         dev->last_flush_error = ret;
3420                         btrfs_dev_stat_inc_and_print(dev,
3421                                         BTRFS_DEV_STAT_FLUSH_ERRS);
3422                         errors_wait++;
3423                 }
3424         }
3425
3426         if (errors_wait) {
3427                 /*
3428                  * At some point we need the status of all disks
3429                  * to arrive at the volume status. So error checking
3430                  * is being pushed to a separate loop.
3431                  */
3432                 return check_barrier_error(info);
3433         }
3434         return 0;
3435 }
3436
3437 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
3438 {
3439         int raid_type;
3440         int min_tolerated = INT_MAX;
3441
3442         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
3443             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
3444                 min_tolerated = min(min_tolerated,
3445                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
3446                                     tolerated_failures);
3447
3448         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3449                 if (raid_type == BTRFS_RAID_SINGLE)
3450                         continue;
3451                 if (!(flags & btrfs_raid_group[raid_type]))
3452                         continue;
3453                 min_tolerated = min(min_tolerated,
3454                                     btrfs_raid_array[raid_type].
3455                                     tolerated_failures);
3456         }
3457
3458         if (min_tolerated == INT_MAX) {
3459                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
3460                 min_tolerated = 0;
3461         }
3462
3463         return min_tolerated;
3464 }
3465
3466 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
3467 {
3468         struct list_head *head;
3469         struct btrfs_device *dev;
3470         struct btrfs_super_block *sb;
3471         struct btrfs_dev_item *dev_item;
3472         int ret;
3473         int do_barriers;
3474         int max_errors;
3475         int total_errors = 0;
3476         u64 flags;
3477
3478         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
3479
3480         /*
3481          * max_mirrors == 0 indicates we're from commit_transaction,
3482          * not from fsync where the tree roots in fs_info have not
3483          * been consistent on disk.
3484          */
3485         if (max_mirrors == 0)
3486                 backup_super_roots(fs_info);
3487
3488         sb = fs_info->super_for_commit;
3489         dev_item = &sb->dev_item;
3490
3491         mutex_lock(&fs_info->fs_devices->device_list_mutex);
3492         head = &fs_info->fs_devices->devices;
3493         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
3494
3495         if (do_barriers) {
3496                 ret = barrier_all_devices(fs_info);
3497                 if (ret) {
3498                         mutex_unlock(
3499                                 &fs_info->fs_devices->device_list_mutex);
3500                         btrfs_handle_fs_error(fs_info, ret,
3501                                               "errors while submitting device barriers.");
3502                         return ret;
3503                 }
3504         }
3505
3506         list_for_each_entry(dev, head, dev_list) {
3507                 if (!dev->bdev) {
3508                         total_errors++;
3509                         continue;
3510                 }
3511                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3512                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3513                         continue;
3514
3515                 btrfs_set_stack_device_generation(dev_item, 0);
3516                 btrfs_set_stack_device_type(dev_item, dev->type);
3517                 btrfs_set_stack_device_id(dev_item, dev->devid);
3518                 btrfs_set_stack_device_total_bytes(dev_item,
3519                                                    dev->commit_total_bytes);
3520                 btrfs_set_stack_device_bytes_used(dev_item,
3521                                                   dev->commit_bytes_used);
3522                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3523                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3524                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3525                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3526                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_FSID_SIZE);
3527
3528                 flags = btrfs_super_flags(sb);
3529                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3530
3531                 ret = write_dev_supers(dev, sb, max_mirrors);
3532                 if (ret)
3533                         total_errors++;
3534         }
3535         if (total_errors > max_errors) {
3536                 btrfs_err(fs_info, "%d errors while writing supers",
3537                           total_errors);
3538                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3539
3540                 /* FUA is masked off if unsupported and can't be the reason */
3541                 btrfs_handle_fs_error(fs_info, -EIO,
3542                                       "%d errors while writing supers",
3543                                       total_errors);
3544                 return -EIO;
3545         }
3546
3547         total_errors = 0;
3548         list_for_each_entry(dev, head, dev_list) {
3549                 if (!dev->bdev)
3550                         continue;
3551                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3552                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3553                         continue;
3554
3555                 ret = wait_dev_supers(dev, max_mirrors);
3556                 if (ret)
3557                         total_errors++;
3558         }
3559         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3560         if (total_errors > max_errors) {
3561                 btrfs_handle_fs_error(fs_info, -EIO,
3562                                       "%d errors while writing supers",
3563                                       total_errors);
3564                 return -EIO;
3565         }
3566         return 0;
3567 }
3568
3569 /* Drop a fs root from the radix tree and free it. */
3570 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
3571                                   struct btrfs_root *root)
3572 {
3573         spin_lock(&fs_info->fs_roots_radix_lock);
3574         radix_tree_delete(&fs_info->fs_roots_radix,
3575                           (unsigned long)root->root_key.objectid);
3576         spin_unlock(&fs_info->fs_roots_radix_lock);
3577
3578         if (btrfs_root_refs(&root->root_item) == 0)
3579                 synchronize_srcu(&fs_info->subvol_srcu);
3580
3581         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
3582                 btrfs_free_log(NULL, root);
3583                 if (root->reloc_root) {
3584                         free_extent_buffer(root->reloc_root->node);
3585                         free_extent_buffer(root->reloc_root->commit_root);
3586                         btrfs_put_fs_root(root->reloc_root);
3587                         root->reloc_root = NULL;
3588                 }
3589         }
3590
3591         if (root->free_ino_pinned)
3592                 __btrfs_remove_free_space_cache(root->free_ino_pinned);
3593         if (root->free_ino_ctl)
3594                 __btrfs_remove_free_space_cache(root->free_ino_ctl);
3595         free_fs_root(root);
3596 }
3597
3598 static void free_fs_root(struct btrfs_root *root)
3599 {
3600         iput(root->ino_cache_inode);
3601         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3602         btrfs_free_block_rsv(root->fs_info, root->orphan_block_rsv);
3603         root->orphan_block_rsv = NULL;
3604         if (root->anon_dev)
3605                 free_anon_bdev(root->anon_dev);
3606         if (root->subv_writers)
3607                 btrfs_free_subvolume_writers(root->subv_writers);
3608         free_extent_buffer(root->node);
3609         free_extent_buffer(root->commit_root);
3610         kfree(root->free_ino_ctl);
3611         kfree(root->free_ino_pinned);
3612         kfree(root->name);
3613         btrfs_put_fs_root(root);
3614 }
3615
3616 void btrfs_free_fs_root(struct btrfs_root *root)
3617 {
3618         free_fs_root(root);
3619 }
3620
3621 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3622 {
3623         u64 root_objectid = 0;
3624         struct btrfs_root *gang[8];
3625         int i = 0;
3626         int err = 0;
3627         unsigned int ret = 0;
3628         int index;
3629
3630         while (1) {
3631                 index = srcu_read_lock(&fs_info->subvol_srcu);
3632                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3633                                              (void **)gang, root_objectid,
3634                                              ARRAY_SIZE(gang));
3635                 if (!ret) {
3636                         srcu_read_unlock(&fs_info->subvol_srcu, index);
3637                         break;
3638                 }
3639                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3640
3641                 for (i = 0; i < ret; i++) {
3642                         /* Avoid to grab roots in dead_roots */
3643                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
3644                                 gang[i] = NULL;
3645                                 continue;
3646                         }
3647                         /* grab all the search result for later use */
3648                         gang[i] = btrfs_grab_fs_root(gang[i]);
3649                 }
3650                 srcu_read_unlock(&fs_info->subvol_srcu, index);
3651
3652                 for (i = 0; i < ret; i++) {
3653                         if (!gang[i])
3654                                 continue;
3655                         root_objectid = gang[i]->root_key.objectid;
3656                         err = btrfs_orphan_cleanup(gang[i]);
3657                         if (err)
3658                                 break;
3659                         btrfs_put_fs_root(gang[i]);
3660                 }
3661                 root_objectid++;
3662         }
3663
3664         /* release the uncleaned roots due to error */
3665         for (; i < ret; i++) {
3666                 if (gang[i])
3667                         btrfs_put_fs_root(gang[i]);
3668         }
3669         return err;
3670 }
3671
3672 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
3673 {
3674         struct btrfs_root *root = fs_info->tree_root;
3675         struct btrfs_trans_handle *trans;
3676
3677         mutex_lock(&fs_info->cleaner_mutex);
3678         btrfs_run_delayed_iputs(fs_info);
3679         mutex_unlock(&fs_info->cleaner_mutex);
3680         wake_up_process(fs_info->cleaner_kthread);
3681
3682         /* wait until ongoing cleanup work done */
3683         down_write(&fs_info->cleanup_work_sem);
3684         up_write(&fs_info->cleanup_work_sem);
3685
3686         trans = btrfs_join_transaction(root);
3687         if (IS_ERR(trans))
3688                 return PTR_ERR(trans);
3689         return btrfs_commit_transaction(trans);
3690 }
3691
3692 void close_ctree(struct btrfs_fs_info *fs_info)
3693 {
3694         struct btrfs_root *root = fs_info->tree_root;
3695         int ret;
3696
3697         set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
3698
3699         /* wait for the qgroup rescan worker to stop */
3700         btrfs_qgroup_wait_for_completion(fs_info, false);
3701
3702         /* wait for the uuid_scan task to finish */
3703         down(&fs_info->uuid_tree_rescan_sem);
3704         /* avoid complains from lockdep et al., set sem back to initial state */
3705         up(&fs_info->uuid_tree_rescan_sem);
3706
3707         /* pause restriper - we want to resume on mount */
3708         btrfs_pause_balance(fs_info);
3709
3710         btrfs_dev_replace_suspend_for_unmount(fs_info);
3711
3712         btrfs_scrub_cancel(fs_info);
3713
3714         /* wait for any defraggers to finish */
3715         wait_event(fs_info->transaction_wait,
3716                    (atomic_read(&fs_info->defrag_running) == 0));
3717
3718         /* clear out the rbtree of defraggable inodes */
3719         btrfs_cleanup_defrag_inodes(fs_info);
3720
3721         cancel_work_sync(&fs_info->async_reclaim_work);
3722
3723         if (!sb_rdonly(fs_info->sb)) {
3724                 /*
3725                  * If the cleaner thread is stopped and there are
3726                  * block groups queued for removal, the deletion will be
3727                  * skipped when we quit the cleaner thread.
3728                  */
3729                 btrfs_delete_unused_bgs(fs_info);
3730
3731                 ret = btrfs_commit_super(fs_info);
3732                 if (ret)
3733                         btrfs_err(fs_info, "commit super ret %d", ret);
3734         }
3735
3736         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3737                 btrfs_error_commit_super(fs_info);
3738
3739         kthread_stop(fs_info->transaction_kthread);
3740         kthread_stop(fs_info->cleaner_kthread);
3741
3742         set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
3743
3744         btrfs_free_qgroup_config(fs_info);
3745
3746         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
3747                 btrfs_info(fs_info, "at unmount delalloc count %lld",
3748                        percpu_counter_sum(&fs_info->delalloc_bytes));
3749         }
3750
3751         btrfs_sysfs_remove_mounted(fs_info);
3752         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3753
3754         btrfs_free_fs_roots(fs_info);
3755
3756         btrfs_put_block_group_cache(fs_info);
3757
3758         /*
3759          * we must make sure there is not any read request to
3760          * submit after we stopping all workers.
3761          */
3762         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3763         btrfs_stop_all_workers(fs_info);
3764
3765         btrfs_free_block_groups(fs_info);
3766
3767         clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
3768         free_root_pointers(fs_info, 1);
3769
3770         iput(fs_info->btree_inode);
3771
3772 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3773         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
3774                 btrfsic_unmount(fs_info->fs_devices);
3775 #endif
3776
3777         btrfs_close_devices(fs_info->fs_devices);
3778         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3779
3780         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3781         percpu_counter_destroy(&fs_info->delalloc_bytes);
3782         percpu_counter_destroy(&fs_info->bio_counter);
3783         cleanup_srcu_struct(&fs_info->subvol_srcu);
3784
3785         btrfs_free_stripe_hash_table(fs_info);
3786         btrfs_free_ref_cache(fs_info);
3787
3788         __btrfs_free_block_rsv(root->orphan_block_rsv);
3789         root->orphan_block_rsv = NULL;
3790
3791         while (!list_empty(&fs_info->pinned_chunks)) {
3792                 struct extent_map *em;
3793
3794                 em = list_first_entry(&fs_info->pinned_chunks,
3795                                       struct extent_map, list);
3796                 list_del_init(&em->list);
3797                 free_extent_map(em);
3798         }
3799 }
3800
3801 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3802                           int atomic)
3803 {
3804         int ret;
3805         struct inode *btree_inode = buf->pages[0]->mapping->host;
3806
3807         ret = extent_buffer_uptodate(buf);