Merge branch 'for-4.14/block-postmerge' of git://git.kernel.dk/linux-block
[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 <asm/unaligned.h>
34 #include "ctree.h"
35 #include "disk-io.h"
36 #include "hash.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "locking.h"
42 #include "tree-log.h"
43 #include "free-space-cache.h"
44 #include "free-space-tree.h"
45 #include "inode-map.h"
46 #include "check-integrity.h"
47 #include "rcu-string.h"
48 #include "dev-replace.h"
49 #include "raid56.h"
50 #include "sysfs.h"
51 #include "qgroup.h"
52 #include "compression.h"
53
54 #ifdef CONFIG_X86
55 #include <asm/cpufeature.h>
56 #endif
57
58 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
59                                  BTRFS_HEADER_FLAG_RELOC |\
60                                  BTRFS_SUPER_FLAG_ERROR |\
61                                  BTRFS_SUPER_FLAG_SEEDING |\
62                                  BTRFS_SUPER_FLAG_METADUMP)
63
64 static const struct extent_io_ops btree_extent_io_ops;
65 static void end_workqueue_fn(struct btrfs_work *work);
66 static void free_fs_root(struct btrfs_root *root);
67 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info);
68 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
69 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
70                                       struct btrfs_fs_info *fs_info);
71 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
72 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
73                                         struct extent_io_tree *dirty_pages,
74                                         int mark);
75 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
76                                        struct extent_io_tree *pinned_extents);
77 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
78 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
79
80 /*
81  * btrfs_end_io_wq structs are used to do processing in task context when an IO
82  * is complete.  This is used during reads to verify checksums, and it is used
83  * by writes to insert metadata for new file extents after IO is complete.
84  */
85 struct btrfs_end_io_wq {
86         struct bio *bio;
87         bio_end_io_t *end_io;
88         void *private;
89         struct btrfs_fs_info *info;
90         blk_status_t status;
91         enum btrfs_wq_endio_type metadata;
92         struct btrfs_work work;
93 };
94
95 static struct kmem_cache *btrfs_end_io_wq_cache;
96
97 int __init btrfs_end_io_wq_init(void)
98 {
99         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
100                                         sizeof(struct btrfs_end_io_wq),
101                                         0,
102                                         SLAB_MEM_SPREAD,
103                                         NULL);
104         if (!btrfs_end_io_wq_cache)
105                 return -ENOMEM;
106         return 0;
107 }
108
109 void btrfs_end_io_wq_exit(void)
110 {
111         kmem_cache_destroy(btrfs_end_io_wq_cache);
112 }
113
114 /*
115  * async submit bios are used to offload expensive checksumming
116  * onto the worker threads.  They checksum file and metadata bios
117  * just before they are sent down the IO stack.
118  */
119 struct async_submit_bio {
120         void *private_data;
121         struct btrfs_fs_info *fs_info;
122         struct bio *bio;
123         extent_submit_bio_hook_t *submit_bio_start;
124         extent_submit_bio_hook_t *submit_bio_done;
125         int mirror_num;
126         unsigned long bio_flags;
127         /*
128          * bio_offset is optional, can be used if the pages in the bio
129          * can't tell us where in the file the bio should go
130          */
131         u64 bio_offset;
132         struct btrfs_work work;
133         blk_status_t status;
134 };
135
136 /*
137  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
138  * eb, the lockdep key is determined by the btrfs_root it belongs to and
139  * the level the eb occupies in the tree.
140  *
141  * Different roots are used for different purposes and may nest inside each
142  * other and they require separate keysets.  As lockdep keys should be
143  * static, assign keysets according to the purpose of the root as indicated
144  * by btrfs_root->objectid.  This ensures that all special purpose roots
145  * have separate keysets.
146  *
147  * Lock-nesting across peer nodes is always done with the immediate parent
148  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
149  * subclass to avoid triggering lockdep warning in such cases.
150  *
151  * The key is set by the readpage_end_io_hook after the buffer has passed
152  * csum validation but before the pages are unlocked.  It is also set by
153  * btrfs_init_new_buffer on freshly allocated blocks.
154  *
155  * We also add a check to make sure the highest level of the tree is the
156  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
157  * needs update as well.
158  */
159 #ifdef CONFIG_DEBUG_LOCK_ALLOC
160 # if BTRFS_MAX_LEVEL != 8
161 #  error
162 # endif
163
164 static struct btrfs_lockdep_keyset {
165         u64                     id;             /* root objectid */
166         const char              *name_stem;     /* lock name stem */
167         char                    names[BTRFS_MAX_LEVEL + 1][20];
168         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
169 } btrfs_lockdep_keysets[] = {
170         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
171         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
172         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
173         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
174         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
175         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
176         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
177         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
178         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
179         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
180         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
181         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
182         { .id = 0,                              .name_stem = "tree"     },
183 };
184
185 void __init btrfs_init_lockdep(void)
186 {
187         int i, j;
188
189         /* initialize lockdep class names */
190         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
191                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
192
193                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
194                         snprintf(ks->names[j], sizeof(ks->names[j]),
195                                  "btrfs-%s-%02d", ks->name_stem, j);
196         }
197 }
198
199 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
200                                     int level)
201 {
202         struct btrfs_lockdep_keyset *ks;
203
204         BUG_ON(level >= ARRAY_SIZE(ks->keys));
205
206         /* find the matching keyset, id 0 is the default entry */
207         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
208                 if (ks->id == objectid)
209                         break;
210
211         lockdep_set_class_and_name(&eb->lock,
212                                    &ks->keys[level], ks->names[level]);
213 }
214
215 #endif
216
217 /*
218  * extents on the btree inode are pretty simple, there's one extent
219  * that covers the entire device
220  */
221 static struct extent_map *btree_get_extent(struct btrfs_inode *inode,
222                 struct page *page, size_t pg_offset, u64 start, u64 len,
223                 int create)
224 {
225         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
226         struct extent_map_tree *em_tree = &inode->extent_tree;
227         struct extent_map *em;
228         int ret;
229
230         read_lock(&em_tree->lock);
231         em = lookup_extent_mapping(em_tree, start, len);
232         if (em) {
233                 em->bdev = fs_info->fs_devices->latest_bdev;
234                 read_unlock(&em_tree->lock);
235                 goto out;
236         }
237         read_unlock(&em_tree->lock);
238
239         em = alloc_extent_map();
240         if (!em) {
241                 em = ERR_PTR(-ENOMEM);
242                 goto out;
243         }
244         em->start = 0;
245         em->len = (u64)-1;
246         em->block_len = (u64)-1;
247         em->block_start = 0;
248         em->bdev = fs_info->fs_devices->latest_bdev;
249
250         write_lock(&em_tree->lock);
251         ret = add_extent_mapping(em_tree, em, 0);
252         if (ret == -EEXIST) {
253                 free_extent_map(em);
254                 em = lookup_extent_mapping(em_tree, start, len);
255                 if (!em)
256                         em = ERR_PTR(-EIO);
257         } else if (ret) {
258                 free_extent_map(em);
259                 em = ERR_PTR(ret);
260         }
261         write_unlock(&em_tree->lock);
262
263 out:
264         return em;
265 }
266
267 u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
268 {
269         return btrfs_crc32c(seed, data, len);
270 }
271
272 void btrfs_csum_final(u32 crc, u8 *result)
273 {
274         put_unaligned_le32(~crc, result);
275 }
276
277 /*
278  * compute the csum for a btree block, and either verify it or write it
279  * into the csum field of the block.
280  */
281 static int csum_tree_block(struct btrfs_fs_info *fs_info,
282                            struct extent_buffer *buf,
283                            int verify)
284 {
285         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
286         char *result = NULL;
287         unsigned long len;
288         unsigned long cur_len;
289         unsigned long offset = BTRFS_CSUM_SIZE;
290         char *kaddr;
291         unsigned long map_start;
292         unsigned long map_len;
293         int err;
294         u32 crc = ~(u32)0;
295         unsigned long inline_result;
296
297         len = buf->len - offset;
298         while (len > 0) {
299                 err = map_private_extent_buffer(buf, offset, 32,
300                                         &kaddr, &map_start, &map_len);
301                 if (err)
302                         return err;
303                 cur_len = min(len, map_len - (offset - map_start));
304                 crc = btrfs_csum_data(kaddr + offset - map_start,
305                                       crc, cur_len);
306                 len -= cur_len;
307                 offset += cur_len;
308         }
309         if (csum_size > sizeof(inline_result)) {
310                 result = kzalloc(csum_size, GFP_NOFS);
311                 if (!result)
312                         return -ENOMEM;
313         } else {
314                 result = (char *)&inline_result;
315         }
316
317         btrfs_csum_final(crc, result);
318
319         if (verify) {
320                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
321                         u32 val;
322                         u32 found = 0;
323                         memcpy(&found, result, csum_size);
324
325                         read_extent_buffer(buf, &val, 0, csum_size);
326                         btrfs_warn_rl(fs_info,
327                                 "%s checksum verify failed on %llu wanted %X found %X level %d",
328                                 fs_info->sb->s_id, buf->start,
329                                 val, found, btrfs_header_level(buf));
330                         if (result != (char *)&inline_result)
331                                 kfree(result);
332                         return -EUCLEAN;
333                 }
334         } else {
335                 write_extent_buffer(buf, result, 0, csum_size);
336         }
337         if (result != (char *)&inline_result)
338                 kfree(result);
339         return 0;
340 }
341
342 /*
343  * we can't consider a given block up to date unless the transid of the
344  * block matches the transid in the parent node's pointer.  This is how we
345  * detect blocks that either didn't get written at all or got written
346  * in the wrong place.
347  */
348 static int verify_parent_transid(struct extent_io_tree *io_tree,
349                                  struct extent_buffer *eb, u64 parent_transid,
350                                  int atomic)
351 {
352         struct extent_state *cached_state = NULL;
353         int ret;
354         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
355
356         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
357                 return 0;
358
359         if (atomic)
360                 return -EAGAIN;
361
362         if (need_lock) {
363                 btrfs_tree_read_lock(eb);
364                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
365         }
366
367         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
368                          &cached_state);
369         if (extent_buffer_uptodate(eb) &&
370             btrfs_header_generation(eb) == parent_transid) {
371                 ret = 0;
372                 goto out;
373         }
374         btrfs_err_rl(eb->fs_info,
375                 "parent transid verify failed on %llu wanted %llu found %llu",
376                         eb->start,
377                         parent_transid, btrfs_header_generation(eb));
378         ret = 1;
379
380         /*
381          * Things reading via commit roots that don't have normal protection,
382          * like send, can have a really old block in cache that may point at a
383          * block that has been freed and re-allocated.  So don't clear uptodate
384          * if we find an eb that is under IO (dirty/writeback) because we could
385          * end up reading in the stale data and then writing it back out and
386          * making everybody very sad.
387          */
388         if (!extent_buffer_under_io(eb))
389                 clear_extent_buffer_uptodate(eb);
390 out:
391         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
392                              &cached_state, GFP_NOFS);
393         if (need_lock)
394                 btrfs_tree_read_unlock_blocking(eb);
395         return ret;
396 }
397
398 /*
399  * Return 0 if the superblock checksum type matches the checksum value of that
400  * algorithm. Pass the raw disk superblock data.
401  */
402 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
403                                   char *raw_disk_sb)
404 {
405         struct btrfs_super_block *disk_sb =
406                 (struct btrfs_super_block *)raw_disk_sb;
407         u16 csum_type = btrfs_super_csum_type(disk_sb);
408         int ret = 0;
409
410         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
411                 u32 crc = ~(u32)0;
412                 const int csum_size = sizeof(crc);
413                 char result[csum_size];
414
415                 /*
416                  * The super_block structure does not span the whole
417                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
418                  * is filled with zeros and is included in the checksum.
419                  */
420                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
421                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
422                 btrfs_csum_final(crc, result);
423
424                 if (memcmp(raw_disk_sb, result, csum_size))
425                         ret = 1;
426         }
427
428         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
429                 btrfs_err(fs_info, "unsupported checksum algorithm %u",
430                                 csum_type);
431                 ret = 1;
432         }
433
434         return ret;
435 }
436
437 /*
438  * helper to read a given tree block, doing retries as required when
439  * the checksums don't match and we have alternate mirrors to try.
440  */
441 static int btree_read_extent_buffer_pages(struct btrfs_fs_info *fs_info,
442                                           struct extent_buffer *eb,
443                                           u64 parent_transid)
444 {
445         struct extent_io_tree *io_tree;
446         int failed = 0;
447         int ret;
448         int num_copies = 0;
449         int mirror_num = 0;
450         int failed_mirror = 0;
451
452         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
453         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
454         while (1) {
455                 ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
456                                                btree_get_extent, mirror_num);
457                 if (!ret) {
458                         if (!verify_parent_transid(io_tree, eb,
459                                                    parent_transid, 0))
460                                 break;
461                         else
462                                 ret = -EIO;
463                 }
464
465                 /*
466                  * This buffer's crc is fine, but its contents are corrupted, so
467                  * there is no reason to read the other copies, they won't be
468                  * any less wrong.
469                  */
470                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
471                         break;
472
473                 num_copies = btrfs_num_copies(fs_info,
474                                               eb->start, eb->len);
475                 if (num_copies == 1)
476                         break;
477
478                 if (!failed_mirror) {
479                         failed = 1;
480                         failed_mirror = eb->read_mirror;
481                 }
482
483                 mirror_num++;
484                 if (mirror_num == failed_mirror)
485                         mirror_num++;
486
487                 if (mirror_num > num_copies)
488                         break;
489         }
490
491         if (failed && !ret && failed_mirror)
492                 repair_eb_io_failure(fs_info, eb, failed_mirror);
493
494         return ret;
495 }
496
497 /*
498  * checksum a dirty tree block before IO.  This has extra checks to make sure
499  * we only fill in the checksum field in the first page of a multi-page block
500  */
501
502 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
503 {
504         u64 start = page_offset(page);
505         u64 found_start;
506         struct extent_buffer *eb;
507
508         eb = (struct extent_buffer *)page->private;
509         if (page != eb->pages[0])
510                 return 0;
511
512         found_start = btrfs_header_bytenr(eb);
513         /*
514          * Please do not consolidate these warnings into a single if.
515          * It is useful to know what went wrong.
516          */
517         if (WARN_ON(found_start != start))
518                 return -EUCLEAN;
519         if (WARN_ON(!PageUptodate(page)))
520                 return -EUCLEAN;
521
522         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
523                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
524
525         return csum_tree_block(fs_info, eb, 0);
526 }
527
528 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
529                                  struct extent_buffer *eb)
530 {
531         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
532         u8 fsid[BTRFS_UUID_SIZE];
533         int ret = 1;
534
535         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
536         while (fs_devices) {
537                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
538                         ret = 0;
539                         break;
540                 }
541                 fs_devices = fs_devices->seed;
542         }
543         return ret;
544 }
545
546 #define CORRUPT(reason, eb, root, slot)                                 \
547         btrfs_crit(root->fs_info,                                       \
548                    "corrupt %s, %s: block=%llu, root=%llu, slot=%d",    \
549                    btrfs_header_level(eb) == 0 ? "leaf" : "node",       \
550                    reason, btrfs_header_bytenr(eb), root->objectid, slot)
551
552 static noinline int check_leaf(struct btrfs_root *root,
553                                struct extent_buffer *leaf)
554 {
555         struct btrfs_fs_info *fs_info = root->fs_info;
556         struct btrfs_key key;
557         struct btrfs_key leaf_key;
558         u32 nritems = btrfs_header_nritems(leaf);
559         int slot;
560
561         /*
562          * Extent buffers from a relocation tree have a owner field that
563          * corresponds to the subvolume tree they are based on. So just from an
564          * extent buffer alone we can not find out what is the id of the
565          * corresponding subvolume tree, so we can not figure out if the extent
566          * buffer corresponds to the root of the relocation tree or not. So skip
567          * this check for relocation trees.
568          */
569         if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
570                 struct btrfs_root *check_root;
571
572                 key.objectid = btrfs_header_owner(leaf);
573                 key.type = BTRFS_ROOT_ITEM_KEY;
574                 key.offset = (u64)-1;
575
576                 check_root = btrfs_get_fs_root(fs_info, &key, false);
577                 /*
578                  * The only reason we also check NULL here is that during
579                  * open_ctree() some roots has not yet been set up.
580                  */
581                 if (!IS_ERR_OR_NULL(check_root)) {
582                         struct extent_buffer *eb;
583
584                         eb = btrfs_root_node(check_root);
585                         /* if leaf is the root, then it's fine */
586                         if (leaf != eb) {
587                                 CORRUPT("non-root leaf's nritems is 0",
588                                         leaf, check_root, 0);
589                                 free_extent_buffer(eb);
590                                 return -EIO;
591                         }
592                         free_extent_buffer(eb);
593                 }
594                 return 0;
595         }
596
597         if (nritems == 0)
598                 return 0;
599
600         /* Check the 0 item */
601         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
602             BTRFS_LEAF_DATA_SIZE(fs_info)) {
603                 CORRUPT("invalid item offset size pair", leaf, root, 0);
604                 return -EIO;
605         }
606
607         /*
608          * Check to make sure each items keys are in the correct order and their
609          * offsets make sense.  We only have to loop through nritems-1 because
610          * we check the current slot against the next slot, which verifies the
611          * next slot's offset+size makes sense and that the current's slot
612          * offset is correct.
613          */
614         for (slot = 0; slot < nritems - 1; slot++) {
615                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
616                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
617
618                 /* Make sure the keys are in the right order */
619                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
620                         CORRUPT("bad key order", leaf, root, slot);
621                         return -EIO;
622                 }
623
624                 /*
625                  * Make sure the offset and ends are right, remember that the
626                  * item data starts at the end of the leaf and grows towards the
627                  * front.
628                  */
629                 if (btrfs_item_offset_nr(leaf, slot) !=
630                         btrfs_item_end_nr(leaf, slot + 1)) {
631                         CORRUPT("slot offset bad", leaf, root, slot);
632                         return -EIO;
633                 }
634
635                 /*
636                  * Check to make sure that we don't point outside of the leaf,
637                  * just in case all the items are consistent to each other, but
638                  * all point outside of the leaf.
639                  */
640                 if (btrfs_item_end_nr(leaf, slot) >
641                     BTRFS_LEAF_DATA_SIZE(fs_info)) {
642                         CORRUPT("slot end outside of leaf", leaf, root, slot);
643                         return -EIO;
644                 }
645         }
646
647         return 0;
648 }
649
650 static int check_node(struct btrfs_root *root, struct extent_buffer *node)
651 {
652         unsigned long nr = btrfs_header_nritems(node);
653         struct btrfs_key key, next_key;
654         int slot;
655         u64 bytenr;
656         int ret = 0;
657
658         if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root->fs_info)) {
659                 btrfs_crit(root->fs_info,
660                            "corrupt node: block %llu root %llu nritems %lu",
661                            node->start, root->objectid, nr);
662                 return -EIO;
663         }
664
665         for (slot = 0; slot < nr - 1; slot++) {
666                 bytenr = btrfs_node_blockptr(node, slot);
667                 btrfs_node_key_to_cpu(node, &key, slot);
668                 btrfs_node_key_to_cpu(node, &next_key, slot + 1);
669
670                 if (!bytenr) {
671                         CORRUPT("invalid item slot", node, root, slot);
672                         ret = -EIO;
673                         goto out;
674                 }
675
676                 if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
677                         CORRUPT("bad key order", node, root, slot);
678                         ret = -EIO;
679                         goto out;
680                 }
681         }
682 out:
683         return ret;
684 }
685
686 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
687                                       u64 phy_offset, struct page *page,
688                                       u64 start, u64 end, int mirror)
689 {
690         u64 found_start;
691         int found_level;
692         struct extent_buffer *eb;
693         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
694         struct btrfs_fs_info *fs_info = root->fs_info;
695         int ret = 0;
696         int reads_done;
697
698         if (!page->private)
699                 goto out;
700
701         eb = (struct extent_buffer *)page->private;
702
703         /* the pending IO might have been the only thing that kept this buffer
704          * in memory.  Make sure we have a ref for all this other checks
705          */
706         extent_buffer_get(eb);
707
708         reads_done = atomic_dec_and_test(&eb->io_pages);
709         if (!reads_done)
710                 goto err;
711
712         eb->read_mirror = mirror;
713         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
714                 ret = -EIO;
715                 goto err;
716         }
717
718         found_start = btrfs_header_bytenr(eb);
719         if (found_start != eb->start) {
720                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
721                              found_start, eb->start);
722                 ret = -EIO;
723                 goto err;
724         }
725         if (check_tree_block_fsid(fs_info, eb)) {
726                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
727                              eb->start);
728                 ret = -EIO;
729                 goto err;
730         }
731         found_level = btrfs_header_level(eb);
732         if (found_level >= BTRFS_MAX_LEVEL) {
733                 btrfs_err(fs_info, "bad tree block level %d",
734                           (int)btrfs_header_level(eb));
735                 ret = -EIO;
736                 goto err;
737         }
738
739         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
740                                        eb, found_level);
741
742         ret = csum_tree_block(fs_info, eb, 1);
743         if (ret)
744                 goto err;
745
746         /*
747          * If this is a leaf block and it is corrupt, set the corrupt bit so
748          * that we don't try and read the other copies of this block, just
749          * return -EIO.
750          */
751         if (found_level == 0 && check_leaf(root, eb)) {
752                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
753                 ret = -EIO;
754         }
755
756         if (found_level > 0 && check_node(root, eb))
757                 ret = -EIO;
758
759         if (!ret)
760                 set_extent_buffer_uptodate(eb);
761 err:
762         if (reads_done &&
763             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
764                 btree_readahead_hook(eb, ret);
765
766         if (ret) {
767                 /*
768                  * our io error hook is going to dec the io pages
769                  * again, we have to make sure it has something
770                  * to decrement
771                  */
772                 atomic_inc(&eb->io_pages);
773                 clear_extent_buffer_uptodate(eb);
774         }
775         free_extent_buffer(eb);
776 out:
777         return ret;
778 }
779
780 static int btree_io_failed_hook(struct page *page, int failed_mirror)
781 {
782         struct extent_buffer *eb;
783
784         eb = (struct extent_buffer *)page->private;
785         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
786         eb->read_mirror = failed_mirror;
787         atomic_dec(&eb->io_pages);
788         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
789                 btree_readahead_hook(eb, -EIO);
790         return -EIO;    /* we fixed nothing */
791 }
792
793 static void end_workqueue_bio(struct bio *bio)
794 {
795         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
796         struct btrfs_fs_info *fs_info;
797         struct btrfs_workqueue *wq;
798         btrfs_work_func_t func;
799
800         fs_info = end_io_wq->info;
801         end_io_wq->status = bio->bi_status;
802
803         if (bio_op(bio) == REQ_OP_WRITE) {
804                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
805                         wq = fs_info->endio_meta_write_workers;
806                         func = btrfs_endio_meta_write_helper;
807                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
808                         wq = fs_info->endio_freespace_worker;
809                         func = btrfs_freespace_write_helper;
810                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
811                         wq = fs_info->endio_raid56_workers;
812                         func = btrfs_endio_raid56_helper;
813                 } else {
814                         wq = fs_info->endio_write_workers;
815                         func = btrfs_endio_write_helper;
816                 }
817         } else {
818                 if (unlikely(end_io_wq->metadata ==
819                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
820                         wq = fs_info->endio_repair_workers;
821                         func = btrfs_endio_repair_helper;
822                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
823                         wq = fs_info->endio_raid56_workers;
824                         func = btrfs_endio_raid56_helper;
825                 } else if (end_io_wq->metadata) {
826                         wq = fs_info->endio_meta_workers;
827                         func = btrfs_endio_meta_helper;
828                 } else {
829                         wq = fs_info->endio_workers;
830                         func = btrfs_endio_helper;
831                 }
832         }
833
834         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
835         btrfs_queue_work(wq, &end_io_wq->work);
836 }
837
838 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
839                         enum btrfs_wq_endio_type metadata)
840 {
841         struct btrfs_end_io_wq *end_io_wq;
842
843         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
844         if (!end_io_wq)
845                 return BLK_STS_RESOURCE;
846
847         end_io_wq->private = bio->bi_private;
848         end_io_wq->end_io = bio->bi_end_io;
849         end_io_wq->info = info;
850         end_io_wq->status = 0;
851         end_io_wq->bio = bio;
852         end_io_wq->metadata = metadata;
853
854         bio->bi_private = end_io_wq;
855         bio->bi_end_io = end_workqueue_bio;
856         return 0;
857 }
858
859 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
860 {
861         unsigned long limit = min_t(unsigned long,
862                                     info->thread_pool_size,
863                                     info->fs_devices->open_devices);
864         return 256 * limit;
865 }
866
867 static void run_one_async_start(struct btrfs_work *work)
868 {
869         struct async_submit_bio *async;
870         blk_status_t ret;
871
872         async = container_of(work, struct  async_submit_bio, work);
873         ret = async->submit_bio_start(async->private_data, async->bio,
874                                       async->mirror_num, async->bio_flags,
875                                       async->bio_offset);
876         if (ret)
877                 async->status = ret;
878 }
879
880 static void run_one_async_done(struct btrfs_work *work)
881 {
882         struct btrfs_fs_info *fs_info;
883         struct async_submit_bio *async;
884         int limit;
885
886         async = container_of(work, struct  async_submit_bio, work);
887         fs_info = async->fs_info;
888
889         limit = btrfs_async_submit_limit(fs_info);
890         limit = limit * 2 / 3;
891
892         /*
893          * atomic_dec_return implies a barrier for waitqueue_active
894          */
895         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
896             waitqueue_active(&fs_info->async_submit_wait))
897                 wake_up(&fs_info->async_submit_wait);
898
899         /* If an error occurred we just want to clean up the bio and move on */
900         if (async->status) {
901                 async->bio->bi_status = async->status;
902                 bio_endio(async->bio);
903                 return;
904         }
905
906         async->submit_bio_done(async->private_data, async->bio, async->mirror_num,
907                                async->bio_flags, async->bio_offset);
908 }
909
910 static void run_one_async_free(struct btrfs_work *work)
911 {
912         struct async_submit_bio *async;
913
914         async = container_of(work, struct  async_submit_bio, work);
915         kfree(async);
916 }
917
918 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
919                                  int mirror_num, unsigned long bio_flags,
920                                  u64 bio_offset, void *private_data,
921                                  extent_submit_bio_hook_t *submit_bio_start,
922                                  extent_submit_bio_hook_t *submit_bio_done)
923 {
924         struct async_submit_bio *async;
925
926         async = kmalloc(sizeof(*async), GFP_NOFS);
927         if (!async)
928                 return BLK_STS_RESOURCE;
929
930         async->private_data = private_data;
931         async->fs_info = fs_info;
932         async->bio = bio;
933         async->mirror_num = mirror_num;
934         async->submit_bio_start = submit_bio_start;
935         async->submit_bio_done = submit_bio_done;
936
937         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
938                         run_one_async_done, run_one_async_free);
939
940         async->bio_flags = bio_flags;
941         async->bio_offset = bio_offset;
942
943         async->status = 0;
944
945         atomic_inc(&fs_info->nr_async_submits);
946
947         if (op_is_sync(bio->bi_opf))
948                 btrfs_set_work_high_priority(&async->work);
949
950         btrfs_queue_work(fs_info->workers, &async->work);
951
952         while (atomic_read(&fs_info->async_submit_draining) &&
953               atomic_read(&fs_info->nr_async_submits)) {
954                 wait_event(fs_info->async_submit_wait,
955                            (atomic_read(&fs_info->nr_async_submits) == 0));
956         }
957
958         return 0;
959 }
960
961 static blk_status_t btree_csum_one_bio(struct bio *bio)
962 {
963         struct bio_vec *bvec;
964         struct btrfs_root *root;
965         int i, ret = 0;
966
967         ASSERT(!bio_flagged(bio, BIO_CLONED));
968         bio_for_each_segment_all(bvec, bio, i) {
969                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
970                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
971                 if (ret)
972                         break;
973         }
974
975         return errno_to_blk_status(ret);
976 }
977
978 static blk_status_t __btree_submit_bio_start(void *private_data, struct bio *bio,
979                                              int mirror_num, unsigned long bio_flags,
980                                              u64 bio_offset)
981 {
982         /*
983          * when we're called for a write, we're already in the async
984          * submission context.  Just jump into btrfs_map_bio
985          */
986         return btree_csum_one_bio(bio);
987 }
988
989 static blk_status_t __btree_submit_bio_done(void *private_data, struct bio *bio,
990                                             int mirror_num, unsigned long bio_flags,
991                                             u64 bio_offset)
992 {
993         struct inode *inode = private_data;
994         blk_status_t ret;
995
996         /*
997          * when we're called for a write, we're already in the async
998          * submission context.  Just jump into btrfs_map_bio
999          */
1000         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), bio, mirror_num, 1);
1001         if (ret) {
1002                 bio->bi_status = ret;
1003                 bio_endio(bio);
1004         }
1005         return ret;
1006 }
1007
1008 static int check_async_write(unsigned long bio_flags)
1009 {
1010         if (bio_flags & EXTENT_BIO_TREE_LOG)
1011                 return 0;
1012 #ifdef CONFIG_X86
1013         if (static_cpu_has(X86_FEATURE_XMM4_2))
1014                 return 0;
1015 #endif
1016         return 1;
1017 }
1018
1019 static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
1020                                           int mirror_num, unsigned long bio_flags,
1021                                           u64 bio_offset)
1022 {
1023         struct inode *inode = private_data;
1024         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1025         int async = check_async_write(bio_flags);
1026         blk_status_t ret;
1027
1028         if (bio_op(bio) != REQ_OP_WRITE) {
1029                 /*
1030                  * called for a read, do the setup so that checksum validation
1031                  * can happen in the async kernel threads
1032                  */
1033                 ret = btrfs_bio_wq_end_io(fs_info, bio,
1034                                           BTRFS_WQ_ENDIO_METADATA);
1035                 if (ret)
1036                         goto out_w_error;
1037                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1038         } else if (!async) {
1039                 ret = btree_csum_one_bio(bio);
1040                 if (ret)
1041                         goto out_w_error;
1042                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1043         } else {
1044                 /*
1045                  * kthread helpers are used to submit writes so that
1046                  * checksumming can happen in parallel across all CPUs
1047                  */
1048                 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
1049                                           bio_offset, private_data,
1050                                           __btree_submit_bio_start,
1051                                           __btree_submit_bio_done);
1052         }
1053
1054         if (ret)
1055                 goto out_w_error;
1056         return 0;
1057
1058 out_w_error:
1059         bio->bi_status = ret;
1060         bio_endio(bio);
1061         return ret;
1062 }
1063
1064 #ifdef CONFIG_MIGRATION
1065 static int btree_migratepage(struct address_space *mapping,
1066                         struct page *newpage, struct page *page,
1067                         enum migrate_mode mode)
1068 {
1069         /*
1070          * we can't safely write a btree page from here,
1071          * we haven't done the locking hook
1072          */
1073         if (PageDirty(page))
1074                 return -EAGAIN;
1075         /*
1076          * Buffers may be managed in a filesystem specific way.
1077          * We must have no buffers or drop them.
1078          */
1079         if (page_has_private(page) &&
1080             !try_to_release_page(page, GFP_KERNEL))
1081                 return -EAGAIN;
1082         return migrate_page(mapping, newpage, page, mode);
1083 }
1084 #endif
1085
1086
1087 static int btree_writepages(struct address_space *mapping,
1088                             struct writeback_control *wbc)
1089 {
1090         struct btrfs_fs_info *fs_info;
1091         int ret;
1092
1093         if (wbc->sync_mode == WB_SYNC_NONE) {
1094
1095                 if (wbc->for_kupdate)
1096                         return 0;
1097
1098                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1099                 /* this is a bit racy, but that's ok */
1100                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1101                                              BTRFS_DIRTY_METADATA_THRESH);
1102                 if (ret < 0)
1103                         return 0;
1104         }
1105         return btree_write_cache_pages(mapping, wbc);
1106 }
1107
1108 static int btree_readpage(struct file *file, struct page *page)
1109 {
1110         struct extent_io_tree *tree;
1111         tree = &BTRFS_I(page->mapping->host)->io_tree;
1112         return extent_read_full_page(tree, page, btree_get_extent, 0);
1113 }
1114
1115 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1116 {
1117         if (PageWriteback(page) || PageDirty(page))
1118                 return 0;
1119
1120         return try_release_extent_buffer(page);
1121 }
1122
1123 static void btree_invalidatepage(struct page *page, unsigned int offset,
1124                                  unsigned int length)
1125 {
1126         struct extent_io_tree *tree;
1127         tree = &BTRFS_I(page->mapping->host)->io_tree;
1128         extent_invalidatepage(tree, page, offset);
1129         btree_releasepage(page, GFP_NOFS);
1130         if (PagePrivate(page)) {
1131                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1132                            "page private not zero on page %llu",
1133                            (unsigned long long)page_offset(page));
1134                 ClearPagePrivate(page);
1135                 set_page_private(page, 0);
1136                 put_page(page);
1137         }
1138 }
1139
1140 static int btree_set_page_dirty(struct page *page)
1141 {
1142 #ifdef DEBUG
1143         struct extent_buffer *eb;
1144
1145         BUG_ON(!PagePrivate(page));
1146         eb = (struct extent_buffer *)page->private;
1147         BUG_ON(!eb);
1148         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1149         BUG_ON(!atomic_read(&eb->refs));
1150         btrfs_assert_tree_locked(eb);
1151 #endif
1152         return __set_page_dirty_nobuffers(page);
1153 }
1154
1155 static const struct address_space_operations btree_aops = {
1156         .readpage       = btree_readpage,
1157         .writepages     = btree_writepages,
1158         .releasepage    = btree_releasepage,
1159         .invalidatepage = btree_invalidatepage,
1160 #ifdef CONFIG_MIGRATION
1161         .migratepage    = btree_migratepage,
1162 #endif
1163         .set_page_dirty = btree_set_page_dirty,
1164 };
1165
1166 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr)
1167 {
1168         struct extent_buffer *buf = NULL;
1169         struct inode *btree_inode = fs_info->btree_inode;
1170
1171         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1172         if (IS_ERR(buf))
1173                 return;
1174         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1175                                  buf, WAIT_NONE, btree_get_extent, 0);
1176         free_extent_buffer(buf);
1177 }
1178
1179 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
1180                          int mirror_num, struct extent_buffer **eb)
1181 {
1182         struct extent_buffer *buf = NULL;
1183         struct inode *btree_inode = fs_info->btree_inode;
1184         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1185         int ret;
1186
1187         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1188         if (IS_ERR(buf))
1189                 return 0;
1190
1191         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1192
1193         ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
1194                                        btree_get_extent, mirror_num);
1195         if (ret) {
1196                 free_extent_buffer(buf);
1197                 return ret;
1198         }
1199
1200         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1201                 free_extent_buffer(buf);
1202                 return -EIO;
1203         } else if (extent_buffer_uptodate(buf)) {
1204                 *eb = buf;
1205         } else {
1206                 free_extent_buffer(buf);
1207         }
1208         return 0;
1209 }
1210
1211 struct extent_buffer *btrfs_find_create_tree_block(
1212                                                 struct btrfs_fs_info *fs_info,
1213                                                 u64 bytenr)
1214 {
1215         if (btrfs_is_testing(fs_info))
1216                 return alloc_test_extent_buffer(fs_info, bytenr);
1217         return alloc_extent_buffer(fs_info, bytenr);
1218 }
1219
1220
1221 int btrfs_write_tree_block(struct extent_buffer *buf)
1222 {
1223         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1224                                         buf->start + buf->len - 1);
1225 }
1226
1227 void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1228 {
1229         filemap_fdatawait_range(buf->pages[0]->mapping,
1230                                 buf->start, buf->start + buf->len - 1);
1231 }
1232
1233 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1234                                       u64 parent_transid)
1235 {
1236         struct extent_buffer *buf = NULL;
1237         int ret;
1238
1239         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1240         if (IS_ERR(buf))
1241                 return buf;
1242
1243         ret = btree_read_extent_buffer_pages(fs_info, buf, parent_transid);
1244         if (ret) {
1245                 free_extent_buffer(buf);
1246                 return ERR_PTR(ret);
1247         }
1248         return buf;
1249
1250 }
1251
1252 void clean_tree_block(struct btrfs_fs_info *fs_info,
1253                       struct extent_buffer *buf)
1254 {
1255         if (btrfs_header_generation(buf) ==
1256             fs_info->running_transaction->transid) {
1257                 btrfs_assert_tree_locked(buf);
1258
1259                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1260                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1261                                                  -buf->len,
1262                                                  fs_info->dirty_metadata_batch);
1263                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1264                         btrfs_set_lock_blocking(buf);
1265                         clear_extent_buffer_dirty(buf);
1266                 }
1267         }
1268 }
1269
1270 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1271 {
1272         struct btrfs_subvolume_writers *writers;
1273         int ret;
1274
1275         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1276         if (!writers)
1277                 return ERR_PTR(-ENOMEM);
1278
1279         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1280         if (ret < 0) {
1281                 kfree(writers);
1282                 return ERR_PTR(ret);
1283         }
1284
1285         init_waitqueue_head(&writers->wait);
1286         return writers;
1287 }
1288
1289 static void
1290 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1291 {
1292         percpu_counter_destroy(&writers->counter);
1293         kfree(writers);
1294 }
1295
1296 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1297                          u64 objectid)
1298 {
1299         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1300         root->node = NULL;
1301         root->commit_root = NULL;
1302         root->state = 0;
1303         root->orphan_cleanup_state = 0;
1304
1305         root->objectid = objectid;
1306         root->last_trans = 0;
1307         root->highest_objectid = 0;
1308         root->nr_delalloc_inodes = 0;
1309         root->nr_ordered_extents = 0;
1310         root->name = NULL;
1311         root->inode_tree = RB_ROOT;
1312         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1313         root->block_rsv = NULL;
1314         root->orphan_block_rsv = NULL;
1315
1316         INIT_LIST_HEAD(&root->dirty_list);
1317         INIT_LIST_HEAD(&root->root_list);
1318         INIT_LIST_HEAD(&root->delalloc_inodes);
1319         INIT_LIST_HEAD(&root->delalloc_root);
1320         INIT_LIST_HEAD(&root->ordered_extents);
1321         INIT_LIST_HEAD(&root->ordered_root);
1322         INIT_LIST_HEAD(&root->logged_list[0]);
1323         INIT_LIST_HEAD(&root->logged_list[1]);
1324         spin_lock_init(&root->orphan_lock);
1325         spin_lock_init(&root->inode_lock);
1326         spin_lock_init(&root->delalloc_lock);
1327         spin_lock_init(&root->ordered_extent_lock);
1328         spin_lock_init(&root->accounting_lock);
1329         spin_lock_init(&root->log_extents_lock[0]);
1330         spin_lock_init(&root->log_extents_lock[1]);
1331         mutex_init(&root->objectid_mutex);
1332         mutex_init(&root->log_mutex);
1333         mutex_init(&root->ordered_extent_mutex);
1334         mutex_init(&root->delalloc_mutex);
1335         init_waitqueue_head(&root->log_writer_wait);
1336         init_waitqueue_head(&root->log_commit_wait[0]);
1337         init_waitqueue_head(&root->log_commit_wait[1]);
1338         INIT_LIST_HEAD(&root->log_ctxs[0]);
1339         INIT_LIST_HEAD(&root->log_ctxs[1]);
1340         atomic_set(&root->log_commit[0], 0);
1341         atomic_set(&root->log_commit[1], 0);
1342         atomic_set(&root->log_writers, 0);
1343         atomic_set(&root->log_batch, 0);
1344         atomic_set(&root->orphan_inodes, 0);
1345         refcount_set(&root->refs, 1);
1346         atomic_set(&root->will_be_snapshoted, 0);
1347         atomic64_set(&root->qgroup_meta_rsv, 0);
1348         root->log_transid = 0;
1349         root->log_transid_committed = -1;
1350         root->last_log_commit = 0;
1351         if (!dummy)
1352                 extent_io_tree_init(&root->dirty_log_pages, NULL);
1353
1354         memset(&root->root_key, 0, sizeof(root->root_key));
1355         memset(&root->root_item, 0, sizeof(root->root_item));
1356         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1357         if (!dummy)
1358                 root->defrag_trans_start = fs_info->generation;
1359         else
1360                 root->defrag_trans_start = 0;
1361         root->root_key.objectid = objectid;
1362         root->anon_dev = 0;
1363
1364         spin_lock_init(&root->root_item_lock);
1365 }
1366
1367 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1368                 gfp_t flags)
1369 {
1370         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1371         if (root)
1372                 root->fs_info = fs_info;
1373         return root;
1374 }
1375
1376 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1377 /* Should only be used by the testing infrastructure */
1378 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1379 {
1380         struct btrfs_root *root;
1381
1382         if (!fs_info)
1383                 return ERR_PTR(-EINVAL);
1384
1385         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1386         if (!root)
1387                 return ERR_PTR(-ENOMEM);
1388
1389         /* We don't use the stripesize in selftest, set it as sectorsize */
1390         __setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1391         root->alloc_bytenr = 0;
1392
1393         return root;
1394 }
1395 #endif
1396
1397 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1398                                      struct btrfs_fs_info *fs_info,
1399                                      u64 objectid)
1400 {
1401         struct extent_buffer *leaf;
1402         struct btrfs_root *tree_root = fs_info->tree_root;
1403         struct btrfs_root *root;
1404         struct btrfs_key key;
1405         int ret = 0;
1406         uuid_le uuid;
1407
1408         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1409         if (!root)
1410                 return ERR_PTR(-ENOMEM);
1411
1412         __setup_root(root, fs_info, objectid);
1413         root->root_key.objectid = objectid;
1414         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1415         root->root_key.offset = 0;
1416
1417         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1418         if (IS_ERR(leaf)) {
1419                 ret = PTR_ERR(leaf);
1420                 leaf = NULL;
1421                 goto fail;
1422         }
1423
1424         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1425         btrfs_set_header_bytenr(leaf, leaf->start);
1426         btrfs_set_header_generation(leaf, trans->transid);
1427         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1428         btrfs_set_header_owner(leaf, objectid);
1429         root->node = leaf;
1430
1431         write_extent_buffer_fsid(leaf, fs_info->fsid);
1432         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
1433         btrfs_mark_buffer_dirty(leaf);
1434
1435         root->commit_root = btrfs_root_node(root);
1436         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1437
1438         root->root_item.flags = 0;
1439         root->root_item.byte_limit = 0;
1440         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1441         btrfs_set_root_generation(&root->root_item, trans->transid);
1442         btrfs_set_root_level(&root->root_item, 0);
1443         btrfs_set_root_refs(&root->root_item, 1);
1444         btrfs_set_root_used(&root->root_item, leaf->len);
1445         btrfs_set_root_last_snapshot(&root->root_item, 0);
1446         btrfs_set_root_dirid(&root->root_item, 0);
1447         uuid_le_gen(&uuid);
1448         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1449         root->root_item.drop_level = 0;
1450
1451         key.objectid = objectid;
1452         key.type = BTRFS_ROOT_ITEM_KEY;
1453         key.offset = 0;
1454         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1455         if (ret)
1456                 goto fail;
1457
1458         btrfs_tree_unlock(leaf);
1459
1460         return root;
1461
1462 fail:
1463         if (leaf) {
1464                 btrfs_tree_unlock(leaf);
1465                 free_extent_buffer(root->commit_root);
1466                 free_extent_buffer(leaf);
1467         }
1468         kfree(root);
1469
1470         return ERR_PTR(ret);
1471 }
1472
1473 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1474                                          struct btrfs_fs_info *fs_info)
1475 {
1476         struct btrfs_root *root;
1477         struct extent_buffer *leaf;
1478
1479         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1480         if (!root)
1481                 return ERR_PTR(-ENOMEM);
1482
1483         __setup_root(root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1484
1485         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1486         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1487         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1488
1489         /*
1490          * DON'T set REF_COWS for log trees
1491          *
1492          * log trees do not get reference counted because they go away
1493          * before a real commit is actually done.  They do store pointers
1494          * to file data extents, and those reference counts still get
1495          * updated (along with back refs to the log tree).
1496          */
1497
1498         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1499                         NULL, 0, 0, 0);
1500         if (IS_ERR(leaf)) {
1501                 kfree(root);
1502                 return ERR_CAST(leaf);
1503         }
1504
1505         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1506         btrfs_set_header_bytenr(leaf, leaf->start);
1507         btrfs_set_header_generation(leaf, trans->transid);
1508         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1509         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1510         root->node = leaf;
1511
1512         write_extent_buffer_fsid(root->node, fs_info->fsid);
1513         btrfs_mark_buffer_dirty(root->node);
1514         btrfs_tree_unlock(root->node);
1515         return root;
1516 }
1517
1518 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1519                              struct btrfs_fs_info *fs_info)
1520 {
1521         struct btrfs_root *log_root;
1522
1523         log_root = alloc_log_tree(trans, fs_info);
1524         if (IS_ERR(log_root))
1525                 return PTR_ERR(log_root);
1526         WARN_ON(fs_info->log_root_tree);
1527         fs_info->log_root_tree = log_root;
1528         return 0;
1529 }
1530
1531 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1532                        struct btrfs_root *root)
1533 {
1534         struct btrfs_fs_info *fs_info = root->fs_info;
1535         struct btrfs_root *log_root;
1536         struct btrfs_inode_item *inode_item;
1537
1538         log_root = alloc_log_tree(trans, fs_info);
1539         if (IS_ERR(log_root))
1540                 return PTR_ERR(log_root);
1541
1542         log_root->last_trans = trans->transid;
1543         log_root->root_key.offset = root->root_key.objectid;
1544
1545         inode_item = &log_root->root_item.inode;
1546         btrfs_set_stack_inode_generation(inode_item, 1);
1547         btrfs_set_stack_inode_size(inode_item, 3);
1548         btrfs_set_stack_inode_nlink(inode_item, 1);
1549         btrfs_set_stack_inode_nbytes(inode_item,
1550                                      fs_info->nodesize);
1551         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1552
1553         btrfs_set_root_node(&log_root->root_item, log_root->node);
1554
1555         WARN_ON(root->log_root);
1556         root->log_root = log_root;
1557         root->log_transid = 0;
1558         root->log_transid_committed = -1;
1559         root->last_log_commit = 0;
1560         return 0;
1561 }
1562
1563 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1564                                                struct btrfs_key *key)
1565 {
1566         struct btrfs_root *root;
1567         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1568         struct btrfs_path *path;
1569         u64 generation;
1570         int ret;
1571
1572         path = btrfs_alloc_path();
1573         if (!path)
1574                 return ERR_PTR(-ENOMEM);
1575
1576         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1577         if (!root) {
1578                 ret = -ENOMEM;
1579                 goto alloc_fail;
1580         }
1581
1582         __setup_root(root, fs_info, key->objectid);
1583
1584         ret = btrfs_find_root(tree_root, key, path,
1585                               &root->root_item, &root->root_key);
1586         if (ret) {
1587                 if (ret > 0)
1588                         ret = -ENOENT;
1589                 goto find_fail;
1590         }
1591
1592         generation = btrfs_root_generation(&root->root_item);
1593         root->node = read_tree_block(fs_info,
1594                                      btrfs_root_bytenr(&root->root_item),
1595                                      generation);
1596         if (IS_ERR(root->node)) {
1597                 ret = PTR_ERR(root->node);
1598                 goto find_fail;
1599         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1600                 ret = -EIO;
1601                 free_extent_buffer(root->node);
1602                 goto find_fail;
1603         }
1604         root->commit_root = btrfs_root_node(root);
1605 out:
1606         btrfs_free_path(path);
1607         return root;
1608
1609 find_fail:
1610         kfree(root);
1611 alloc_fail:
1612         root = ERR_PTR(ret);
1613         goto out;
1614 }
1615
1616 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1617                                       struct btrfs_key *location)
1618 {
1619         struct btrfs_root *root;
1620
1621         root = btrfs_read_tree_root(tree_root, location);
1622         if (IS_ERR(root))
1623                 return root;
1624
1625         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1626                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1627                 btrfs_check_and_init_root_item(&root->root_item);
1628         }
1629
1630         return root;
1631 }
1632
1633 int btrfs_init_fs_root(struct btrfs_root *root)
1634 {
1635         int ret;
1636         struct btrfs_subvolume_writers *writers;
1637
1638         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1639         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1640                                         GFP_NOFS);
1641         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1642                 ret = -ENOMEM;
1643                 goto fail;
1644         }
1645
1646         writers = btrfs_alloc_subvolume_writers();
1647         if (IS_ERR(writers)) {
1648                 ret = PTR_ERR(writers);
1649                 goto fail;
1650         }
1651         root->subv_writers = writers;
1652
1653         btrfs_init_free_ino_ctl(root);
1654         spin_lock_init(&root->ino_cache_lock);
1655         init_waitqueue_head(&root->ino_cache_wait);
1656
1657         ret = get_anon_bdev(&root->anon_dev);
1658         if (ret)
1659                 goto fail;
1660
1661         mutex_lock(&root->objectid_mutex);
1662         ret = btrfs_find_highest_objectid(root,
1663                                         &root->highest_objectid);
1664         if (ret) {
1665                 mutex_unlock(&root->objectid_mutex);
1666                 goto fail;
1667         }
1668
1669         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1670
1671         mutex_unlock(&root->objectid_mutex);
1672
1673         return 0;
1674 fail:
1675         /* the caller is responsible to call free_fs_root */
1676         return ret;
1677 }
1678
1679 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1680                                         u64 root_id)
1681 {
1682         struct btrfs_root *root;
1683
1684         spin_lock(&fs_info->fs_roots_radix_lock);
1685         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1686                                  (unsigned long)root_id);
1687         spin_unlock(&fs_info->fs_roots_radix_lock);
1688         return root;
1689 }
1690
1691 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1692                          struct btrfs_root *root)
1693 {
1694         int ret;
1695
1696         ret = radix_tree_preload(GFP_NOFS);
1697         if (ret)
1698                 return ret;
1699
1700         spin_lock(&fs_info->fs_roots_radix_lock);
1701         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1702                                 (unsigned long)root->root_key.objectid,
1703                                 root);
1704         if (ret == 0)
1705                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1706         spin_unlock(&fs_info->fs_roots_radix_lock);
1707         radix_tree_preload_end();
1708
1709         return ret;
1710 }
1711
1712 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1713                                      struct btrfs_key *location,
1714                                      bool check_ref)
1715 {
1716         struct btrfs_root *root;
1717         struct btrfs_path *path;
1718         struct btrfs_key key;
1719         int ret;
1720
1721         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1722                 return fs_info->tree_root;
1723         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1724                 return fs_info->extent_root;
1725         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1726                 return fs_info->chunk_root;
1727         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1728                 return fs_info->dev_root;
1729         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1730                 return fs_info->csum_root;
1731         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1732                 return fs_info->quota_root ? fs_info->quota_root :
1733                                              ERR_PTR(-ENOENT);
1734         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1735                 return fs_info->uuid_root ? fs_info->uuid_root :
1736                                             ERR_PTR(-ENOENT);
1737         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1738                 return fs_info->free_space_root ? fs_info->free_space_root :
1739                                                   ERR_PTR(-ENOENT);
1740 again:
1741         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1742         if (root) {
1743                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1744                         return ERR_PTR(-ENOENT);
1745                 return root;
1746         }
1747
1748         root = btrfs_read_fs_root(fs_info->tree_root, location);
1749         if (IS_ERR(root))
1750                 return root;
1751
1752         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1753                 ret = -ENOENT;
1754                 goto fail;
1755         }
1756
1757         ret = btrfs_init_fs_root(root);
1758         if (ret)
1759                 goto fail;
1760
1761         path = btrfs_alloc_path();
1762         if (!path) {
1763                 ret = -ENOMEM;
1764                 goto fail;
1765         }
1766         key.objectid = BTRFS_ORPHAN_OBJECTID;
1767         key.type = BTRFS_ORPHAN_ITEM_KEY;
1768         key.offset = location->objectid;
1769
1770         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1771         btrfs_free_path(path);
1772         if (ret < 0)
1773                 goto fail;
1774         if (ret == 0)
1775                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1776
1777         ret = btrfs_insert_fs_root(fs_info, root);
1778         if (ret) {
1779                 if (ret == -EEXIST) {
1780                         free_fs_root(root);
1781                         goto again;
1782                 }
1783                 goto fail;
1784         }
1785         return root;
1786 fail:
1787         free_fs_root(root);
1788         return ERR_PTR(ret);
1789 }
1790
1791 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1792 {
1793         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1794         int ret = 0;
1795         struct btrfs_device *device;
1796         struct backing_dev_info *bdi;
1797
1798         rcu_read_lock();
1799         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1800                 if (!device->bdev)
1801                         continue;
1802                 bdi = device->bdev->bd_bdi;
1803                 if (bdi_congested(bdi, bdi_bits)) {
1804                         ret = 1;
1805                         break;
1806                 }
1807         }
1808         rcu_read_unlock();
1809         return ret;
1810 }
1811
1812 /*
1813  * called by the kthread helper functions to finally call the bio end_io
1814  * functions.  This is where read checksum verification actually happens
1815  */
1816 static void end_workqueue_fn(struct btrfs_work *work)
1817 {
1818         struct bio *bio;
1819         struct btrfs_end_io_wq *end_io_wq;
1820
1821         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1822         bio = end_io_wq->bio;
1823
1824         bio->bi_status = end_io_wq->status;
1825         bio->bi_private = end_io_wq->private;
1826         bio->bi_end_io = end_io_wq->end_io;
1827         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1828         bio_endio(bio);
1829 }
1830
1831 static int cleaner_kthread(void *arg)
1832 {
1833         struct btrfs_root *root = arg;
1834         struct btrfs_fs_info *fs_info = root->fs_info;
1835         int again;
1836         struct btrfs_trans_handle *trans;
1837
1838         do {
1839                 again = 0;
1840
1841                 /* Make the cleaner go to sleep early. */
1842                 if (btrfs_need_cleaner_sleep(fs_info))
1843                         goto sleep;
1844
1845                 /*
1846                  * Do not do anything if we might cause open_ctree() to block
1847                  * before we have finished mounting the filesystem.
1848                  */
1849                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1850                         goto sleep;
1851
1852                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1853                         goto sleep;
1854
1855                 /*
1856                  * Avoid the problem that we change the status of the fs
1857                  * during the above check and trylock.
1858                  */
1859                 if (btrfs_need_cleaner_sleep(fs_info)) {
1860                         mutex_unlock(&fs_info->cleaner_mutex);
1861                         goto sleep;
1862                 }
1863
1864                 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
1865                 btrfs_run_delayed_iputs(fs_info);
1866                 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
1867
1868                 again = btrfs_clean_one_deleted_snapshot(root);
1869                 mutex_unlock(&fs_info->cleaner_mutex);
1870
1871                 /*
1872                  * The defragger has dealt with the R/O remount and umount,
1873                  * needn't do anything special here.
1874                  */
1875                 btrfs_run_defrag_inodes(fs_info);
1876
1877                 /*
1878                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1879                  * with relocation (btrfs_relocate_chunk) and relocation
1880                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1881                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1882                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1883                  * unused block groups.
1884                  */
1885                 btrfs_delete_unused_bgs(fs_info);
1886 sleep:
1887                 if (!again) {
1888                         set_current_state(TASK_INTERRUPTIBLE);
1889                         if (!kthread_should_stop())
1890                                 schedule();
1891                         __set_current_state(TASK_RUNNING);
1892                 }
1893         } while (!kthread_should_stop());
1894
1895         /*
1896          * Transaction kthread is stopped before us and wakes us up.
1897          * However we might have started a new transaction and COWed some
1898          * tree blocks when deleting unused block groups for example. So
1899          * make sure we commit the transaction we started to have a clean
1900          * shutdown when evicting the btree inode - if it has dirty pages
1901          * when we do the final iput() on it, eviction will trigger a
1902          * writeback for it which will fail with null pointer dereferences
1903          * since work queues and other resources were already released and
1904          * destroyed by the time the iput/eviction/writeback is made.
1905          */
1906         trans = btrfs_attach_transaction(root);
1907         if (IS_ERR(trans)) {
1908                 if (PTR_ERR(trans) != -ENOENT)
1909                         btrfs_err(fs_info,
1910                                   "cleaner transaction attach returned %ld",
1911                                   PTR_ERR(trans));
1912         } else {
1913                 int ret;
1914
1915                 ret = btrfs_commit_transaction(trans);
1916                 if (ret)
1917                         btrfs_err(fs_info,
1918                                   "cleaner open transaction commit returned %d",
1919                                   ret);
1920         }
1921
1922         return 0;
1923 }
1924
1925 static int transaction_kthread(void *arg)
1926 {
1927         struct btrfs_root *root = arg;
1928         struct btrfs_fs_info *fs_info = root->fs_info;
1929         struct btrfs_trans_handle *trans;
1930         struct btrfs_transaction *cur;
1931         u64 transid;
1932         unsigned long now;
1933         unsigned long delay;
1934         bool cannot_commit;
1935
1936         do {
1937                 cannot_commit = false;
1938                 delay = HZ * fs_info->commit_interval;
1939                 mutex_lock(&fs_info->transaction_kthread_mutex);
1940
1941                 spin_lock(&fs_info->trans_lock);
1942                 cur = fs_info->running_transaction;
1943                 if (!cur) {
1944                         spin_unlock(&fs_info->trans_lock);
1945                         goto sleep;
1946                 }
1947
1948                 now = get_seconds();
1949                 if (cur->state < TRANS_STATE_BLOCKED &&
1950                     (now < cur->start_time ||
1951                      now - cur->start_time < fs_info->commit_interval)) {
1952                         spin_unlock(&fs_info->trans_lock);
1953                         delay = HZ * 5;
1954                         goto sleep;
1955                 }
1956                 transid = cur->transid;
1957                 spin_unlock(&fs_info->trans_lock);
1958
1959                 /* If the file system is aborted, this will always fail. */
1960                 trans = btrfs_attach_transaction(root);
1961                 if (IS_ERR(trans)) {
1962                         if (PTR_ERR(trans) != -ENOENT)
1963                                 cannot_commit = true;
1964                         goto sleep;
1965                 }
1966                 if (transid == trans->transid) {
1967                         btrfs_commit_transaction(trans);
1968                 } else {
1969                         btrfs_end_transaction(trans);
1970                 }
1971 sleep:
1972                 wake_up_process(fs_info->cleaner_kthread);
1973                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1974
1975                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1976                                       &fs_info->fs_state)))
1977                         btrfs_cleanup_transaction(fs_info);
1978                 set_current_state(TASK_INTERRUPTIBLE);
1979                 if (!kthread_should_stop() &&
1980                                 (!btrfs_transaction_blocked(fs_info) ||
1981                                  cannot_commit))
1982                         schedule_timeout(delay);
1983                 __set_current_state(TASK_RUNNING);
1984         } while (!kthread_should_stop());
1985         return 0;
1986 }
1987
1988 /*
1989  * this will find the highest generation in the array of
1990  * root backups.  The index of the highest array is returned,
1991  * or -1 if we can't find anything.
1992  *
1993  * We check to make sure the array is valid by comparing the
1994  * generation of the latest  root in the array with the generation
1995  * in the super block.  If they don't match we pitch it.
1996  */
1997 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1998 {
1999         u64 cur;
2000         int newest_index = -1;
2001         struct btrfs_root_backup *root_backup;
2002         int i;
2003
2004         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2005                 root_backup = info->super_copy->super_roots + i;
2006                 cur = btrfs_backup_tree_root_gen(root_backup);
2007                 if (cur == newest_gen)
2008                         newest_index = i;
2009         }
2010
2011         /* check to see if we actually wrapped around */
2012         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
2013                 root_backup = info->super_copy->super_roots;
2014                 cur = btrfs_backup_tree_root_gen(root_backup);
2015                 if (cur == newest_gen)
2016                         newest_index = 0;
2017         }
2018         return newest_index;
2019 }
2020
2021
2022 /*
2023  * find the oldest backup so we know where to store new entries
2024  * in the backup array.  This will set the backup_root_index
2025  * field in the fs_info struct
2026  */
2027 static void find_oldest_super_backup(struct btrfs_fs_info *info,
2028                                      u64 newest_gen)
2029 {
2030         int newest_index = -1;
2031
2032         newest_index = find_newest_super_backup(info, newest_gen);
2033         /* if there was garbage in there, just move along */
2034         if (newest_index == -1) {
2035                 info->backup_root_index = 0;
2036         } else {
2037                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
2038         }
2039 }
2040
2041 /*
2042  * copy all the root pointers into the super backup array.
2043  * this will bump the backup pointer by one when it is
2044  * done
2045  */
2046 static void backup_super_roots(struct btrfs_fs_info *info)
2047 {
2048         int next_backup;
2049         struct btrfs_root_backup *root_backup;
2050         int last_backup;
2051
2052         next_backup = info->backup_root_index;
2053         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
2054                 BTRFS_NUM_BACKUP_ROOTS;
2055
2056         /*
2057          * just overwrite the last backup if we're at the same generation
2058          * this happens only at umount
2059          */
2060         root_backup = info->super_for_commit->super_roots + last_backup;
2061         if (btrfs_backup_tree_root_gen(root_backup) ==
2062             btrfs_header_generation(info->tree_root->node))
2063                 next_backup = last_backup;
2064
2065         root_backup = info->super_for_commit->super_roots + next_backup;
2066
2067         /*
2068          * make sure all of our padding and empty slots get zero filled
2069          * regardless of which ones we use today
2070          */
2071         memset(root_backup, 0, sizeof(*root_backup));
2072
2073         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2074
2075         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2076         btrfs_set_backup_tree_root_gen(root_backup,
2077                                btrfs_header_generation(info->tree_root->node));
2078
2079         btrfs_set_backup_tree_root_level(root_backup,
2080                                btrfs_header_level(info->tree_root->node));
2081
2082         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2083         btrfs_set_backup_chunk_root_gen(root_backup,
2084                                btrfs_header_generation(info->chunk_root->node));
2085         btrfs_set_backup_chunk_root_level(root_backup,
2086                                btrfs_header_level(info->chunk_root->node));
2087
2088         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2089         btrfs_set_backup_extent_root_gen(root_backup,
2090                                btrfs_header_generation(info->extent_root->node));
2091         btrfs_set_backup_extent_root_level(root_backup,
2092                                btrfs_header_level(info->extent_root->node));
2093
2094         /*
2095          * we might commit during log recovery, which happens before we set
2096          * the fs_root.  Make sure it is valid before we fill it in.
2097          */
2098         if (info->fs_root && info->fs_root->node) {
2099                 btrfs_set_backup_fs_root(root_backup,
2100                                          info->fs_root->node->start);
2101                 btrfs_set_backup_fs_root_gen(root_backup,
2102                                btrfs_header_generation(info->fs_root->node));
2103                 btrfs_set_backup_fs_root_level(root_backup,
2104                                btrfs_header_level(info->fs_root->node));
2105         }
2106
2107         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2108         btrfs_set_backup_dev_root_gen(root_backup,
2109                                btrfs_header_generation(info->dev_root->node));
2110         btrfs_set_backup_dev_root_level(root_backup,
2111                                        btrfs_header_level(info->dev_root->node));
2112
2113         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2114         btrfs_set_backup_csum_root_gen(root_backup,
2115                                btrfs_header_generation(info->csum_root->node));
2116         btrfs_set_backup_csum_root_level(root_backup,
2117                                btrfs_header_level(info->csum_root->node));
2118
2119         btrfs_set_backup_total_bytes(root_backup,
2120                              btrfs_super_total_bytes(info->super_copy));
2121         btrfs_set_backup_bytes_used(root_backup,
2122                              btrfs_super_bytes_used(info->super_copy));
2123         btrfs_set_backup_num_devices(root_backup,
2124                              btrfs_super_num_devices(info->super_copy));
2125
2126         /*
2127          * if we don't copy this out to the super_copy, it won't get remembered
2128          * for the next commit
2129          */
2130         memcpy(&info->super_copy->super_roots,
2131                &info->super_for_commit->super_roots,
2132                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2133 }
2134
2135 /*
2136  * this copies info out of the root backup array and back into
2137  * the in-memory super block.  It is meant to help iterate through
2138  * the array, so you send it the number of backups you've already
2139  * tried and the last backup index you used.
2140  *
2141  * this returns -1 when it has tried all the backups
2142  */
2143 static noinline int next_root_backup(struct btrfs_fs_info *info,
2144                                      struct btrfs_super_block *super,
2145                                      int *num_backups_tried, int *backup_index)
2146 {
2147         struct btrfs_root_backup *root_backup;
2148         int newest = *backup_index;
2149
2150         if (*num_backups_tried == 0) {
2151                 u64 gen = btrfs_super_generation(super);
2152
2153                 newest = find_newest_super_backup(info, gen);
2154                 if (newest == -1)
2155                         return -1;
2156
2157                 *backup_index = newest;
2158                 *num_backups_tried = 1;
2159         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2160                 /* we've tried all the backups, all done */
2161                 return -1;
2162         } else {
2163                 /* jump to the next oldest backup */
2164                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2165                         BTRFS_NUM_BACKUP_ROOTS;
2166                 *backup_index = newest;
2167                 *num_backups_tried += 1;
2168         }
2169         root_backup = super->super_roots + newest;
2170
2171         btrfs_set_super_generation(super,
2172                                    btrfs_backup_tree_root_gen(root_backup));
2173         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2174         btrfs_set_super_root_level(super,
2175                                    btrfs_backup_tree_root_level(root_backup));
2176         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2177
2178         /*
2179          * fixme: the total bytes and num_devices need to match or we should
2180          * need a fsck
2181          */
2182         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2183         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2184         return 0;
2185 }
2186
2187 /* helper to cleanup workers */
2188 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2189 {
2190         btrfs_destroy_workqueue(fs_info->fixup_workers);
2191         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2192         btrfs_destroy_workqueue(fs_info->workers);
2193         btrfs_destroy_workqueue(fs_info->endio_workers);
2194         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2195         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2196         btrfs_destroy_workqueue(fs_info->rmw_workers);
2197         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2198         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2199         btrfs_destroy_workqueue(fs_info->submit_workers);
2200         btrfs_destroy_workqueue(fs_info->delayed_workers);
2201         btrfs_destroy_workqueue(fs_info->caching_workers);
2202         btrfs_destroy_workqueue(fs_info->readahead_workers);
2203         btrfs_destroy_workqueue(fs_info->flush_workers);
2204         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2205         btrfs_destroy_workqueue(fs_info->extent_workers);
2206         /*
2207          * Now that all other work queues are destroyed, we can safely destroy
2208          * the queues used for metadata I/O, since tasks from those other work
2209          * queues can do metadata I/O operations.
2210          */
2211         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2212         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2213 }
2214
2215 static void free_root_extent_buffers(struct btrfs_root *root)
2216 {
2217         if (root) {
2218                 free_extent_buffer(root->node);
2219                 free_extent_buffer(root->commit_root);
2220                 root->node = NULL;
2221                 root->commit_root = NULL;
2222         }
2223 }
2224
2225 /* helper to cleanup tree roots */
2226 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2227 {
2228         free_root_extent_buffers(info->tree_root);
2229
2230         free_root_extent_buffers(info->dev_root);
2231         free_root_extent_buffers(info->extent_root);
2232         free_root_extent_buffers(info->csum_root);
2233         free_root_extent_buffers(info->quota_root);
2234         free_root_extent_buffers(info->uuid_root);
2235         if (chunk_root)
2236                 free_root_extent_buffers(info->chunk_root);
2237         free_root_extent_buffers(info->free_space_root);
2238 }
2239
2240 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2241 {
2242         int ret;
2243         struct btrfs_root *gang[8];
2244         int i;
2245
2246         while (!list_empty(&fs_info->dead_roots)) {
2247                 gang[0] = list_entry(fs_info->dead_roots.next,
2248                                      struct btrfs_root, root_list);
2249                 list_del(&gang[0]->root_list);
2250
2251                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2252                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2253                 } else {
2254                         free_extent_buffer(gang[0]->node);
2255                         free_extent_buffer(gang[0]->commit_root);
2256                         btrfs_put_fs_root(gang[0]);
2257                 }
2258         }
2259
2260         while (1) {
2261                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2262                                              (void **)gang, 0,
2263                                              ARRAY_SIZE(gang));
2264                 if (!ret)
2265                         break;
2266                 for (i = 0; i < ret; i++)
2267                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2268         }
2269
2270         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2271                 btrfs_free_log_root_tree(NULL, fs_info);
2272                 btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
2273         }
2274 }
2275
2276 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2277 {
2278         mutex_init(&fs_info->scrub_lock);
2279         atomic_set(&fs_info->scrubs_running, 0);
2280         atomic_set(&fs_info->scrub_pause_req, 0);
2281         atomic_set(&fs_info->scrubs_paused, 0);
2282         atomic_set(&fs_info->scrub_cancel_req, 0);
2283         init_waitqueue_head(&fs_info->scrub_pause_wait);
2284         fs_info->scrub_workers_refcnt = 0;
2285 }
2286
2287 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2288 {
2289         spin_lock_init(&fs_info->balance_lock);
2290         mutex_init(&fs_info->balance_mutex);
2291         atomic_set(&fs_info->balance_running, 0);
2292         atomic_set(&fs_info->balance_pause_req, 0);
2293         atomic_set(&fs_info->balance_cancel_req, 0);
2294         fs_info->balance_ctl = NULL;
2295         init_waitqueue_head(&fs_info->balance_wait_q);
2296 }
2297
2298 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2299 {
2300         struct inode *inode = fs_info->btree_inode;
2301
2302         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2303         set_nlink(inode, 1);
2304         /*
2305          * we set the i_size on the btree inode to the max possible int.
2306          * the real end of the address space is determined by all of
2307          * the devices in the system
2308          */
2309         inode->i_size = OFFSET_MAX;
2310         inode->i_mapping->a_ops = &btree_aops;
2311
2312         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2313         extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode);
2314         BTRFS_I(inode)->io_tree.track_uptodate = 0;
2315         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2316
2317         BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
2318
2319         BTRFS_I(inode)->root = fs_info->tree_root;
2320         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2321         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2322         btrfs_insert_inode_hash(inode);
2323 }
2324
2325 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2326 {
2327         fs_info->dev_replace.lock_owner = 0;
2328         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2329         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2330         rwlock_init(&fs_info->dev_replace.lock);
2331         atomic_set(&fs_info->dev_replace.read_locks, 0);
2332         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2333         init_waitqueue_head(&fs_info->replace_wait);
2334         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2335 }
2336
2337 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2338 {
2339         spin_lock_init(&fs_info->qgroup_lock);
2340         mutex_init(&fs_info->qgroup_ioctl_lock);
2341         fs_info->qgroup_tree = RB_ROOT;
2342         fs_info->qgroup_op_tree = RB_ROOT;
2343         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2344         fs_info->qgroup_seq = 1;
2345         fs_info->qgroup_ulist = NULL;
2346         fs_info->qgroup_rescan_running = false;
2347         mutex_init(&fs_info->qgroup_rescan_lock);
2348 }
2349
2350 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2351                 struct btrfs_fs_devices *fs_devices)
2352 {
2353         int max_active = fs_info->thread_pool_size;
2354         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2355
2356         fs_info->workers =
2357                 btrfs_alloc_workqueue(fs_info, "worker",
2358                                       flags | WQ_HIGHPRI, max_active, 16);
2359
2360         fs_info->delalloc_workers =
2361                 btrfs_alloc_workqueue(fs_info, "delalloc",
2362                                       flags, max_active, 2);
2363
2364         fs_info->flush_workers =
2365                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2366                                       flags, max_active, 0);
2367
2368         fs_info->caching_workers =
2369                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2370
2371         /*
2372          * a higher idle thresh on the submit workers makes it much more
2373          * likely that bios will be send down in a sane order to the
2374          * devices
2375          */
2376         fs_info->submit_workers =
2377                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2378                                       min_t(u64, fs_devices->num_devices,
2379                                             max_active), 64);
2380
2381         fs_info->fixup_workers =
2382                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2383
2384         /*
2385          * endios are largely parallel and should have a very
2386          * low idle thresh
2387          */
2388         fs_info->endio_workers =
2389                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2390         fs_info->endio_meta_workers =
2391                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2392                                       max_active, 4);
2393         fs_info->endio_meta_write_workers =
2394                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2395                                       max_active, 2);
2396         fs_info->endio_raid56_workers =
2397                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2398                                       max_active, 4);
2399         fs_info->endio_repair_workers =
2400                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2401         fs_info->rmw_workers =
2402                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2403         fs_info->endio_write_workers =
2404                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2405                                       max_active, 2);
2406         fs_info->endio_freespace_worker =
2407                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2408                                       max_active, 0);
2409         fs_info->delayed_workers =
2410                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2411                                       max_active, 0);
2412         fs_info->readahead_workers =
2413                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2414                                       max_active, 2);
2415         fs_info->qgroup_rescan_workers =
2416                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2417         fs_info->extent_workers =
2418                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2419                                       min_t(u64, fs_devices->num_devices,
2420                                             max_active), 8);
2421
2422         if (!(fs_info->workers && fs_info->delalloc_workers &&
2423               fs_info->submit_workers && fs_info->flush_workers &&
2424               fs_info->endio_workers && fs_info->endio_meta_workers &&
2425               fs_info->endio_meta_write_workers &&
2426               fs_info->endio_repair_workers &&
2427               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2428               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2429               fs_info->caching_workers && fs_info->readahead_workers &&
2430               fs_info->fixup_workers && fs_info->delayed_workers &&
2431               fs_info->extent_workers &&
2432               fs_info->qgroup_rescan_workers)) {
2433                 return -ENOMEM;
2434         }
2435
2436         return 0;
2437 }
2438
2439 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2440                             struct btrfs_fs_devices *fs_devices)
2441 {
2442         int ret;
2443         struct btrfs_root *log_tree_root;
2444         struct btrfs_super_block *disk_super = fs_info->super_copy;
2445         u64 bytenr = btrfs_super_log_root(disk_super);
2446
2447         if (fs_devices->rw_devices == 0) {
2448                 btrfs_warn(fs_info, "log replay required on RO media");
2449                 return -EIO;
2450         }
2451
2452         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2453         if (!log_tree_root)
2454                 return -ENOMEM;
2455
2456         __setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2457
2458         log_tree_root->node = read_tree_block(fs_info, bytenr,
2459                                               fs_info->generation + 1);
2460         if (IS_ERR(log_tree_root->node)) {
2461                 btrfs_warn(fs_info, "failed to read log tree");
2462                 ret = PTR_ERR(log_tree_root->node);
2463                 kfree(log_tree_root);
2464                 return ret;
2465         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2466                 btrfs_err(fs_info, "failed to read log tree");
2467                 free_extent_buffer(log_tree_root->node);
2468                 kfree(log_tree_root);
2469                 return -EIO;
2470         }
2471         /* returns with log_tree_root freed on success */
2472         ret = btrfs_recover_log_trees(log_tree_root);
2473         if (ret) {
2474                 btrfs_handle_fs_error(fs_info, ret,
2475                                       "Failed to recover log tree");
2476                 free_extent_buffer(log_tree_root->node);
2477                 kfree(log_tree_root);
2478                 return ret;
2479         }
2480
2481         if (fs_info->sb->s_flags & MS_RDONLY) {
2482                 ret = btrfs_commit_super(fs_info);
2483                 if (ret)
2484                         return ret;
2485         }
2486
2487         return 0;
2488 }
2489
2490 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2491 {
2492         struct btrfs_root *tree_root = fs_info->tree_root;
2493         struct btrfs_root *root;
2494         struct btrfs_key location;
2495         int ret;
2496
2497         BUG_ON(!fs_info->tree_root);
2498
2499         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2500         location.type = BTRFS_ROOT_ITEM_KEY;
2501         location.offset = 0;
2502
2503         root = btrfs_read_tree_root(tree_root, &location);
2504         if (IS_ERR(root))
2505                 return PTR_ERR(root);
2506         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2507         fs_info->extent_root = root;
2508
2509         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2510         root = btrfs_read_tree_root(tree_root, &location);
2511         if (IS_ERR(root))
2512                 return PTR_ERR(root);
2513         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2514         fs_info->dev_root = root;
2515         btrfs_init_devices_late(fs_info);
2516
2517         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2518         root = btrfs_read_tree_root(tree_root, &location);
2519         if (IS_ERR(root))
2520                 return PTR_ERR(root);
2521         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2522         fs_info->csum_root = root;
2523
2524         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2525         root = btrfs_read_tree_root(tree_root, &location);
2526         if (!IS_ERR(root)) {
2527                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2528                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2529                 fs_info->quota_root = root;
2530         }
2531
2532         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2533         root = btrfs_read_tree_root(tree_root, &location);
2534         if (IS_ERR(root)) {
2535                 ret = PTR_ERR(root);
2536                 if (ret != -ENOENT)
2537                         return ret;
2538         } else {
2539                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2540                 fs_info->uuid_root = root;
2541         }
2542
2543         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2544                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2545                 root = btrfs_read_tree_root(tree_root, &location);
2546                 if (IS_ERR(root))
2547                         return PTR_ERR(root);
2548                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2549                 fs_info->free_space_root = root;
2550         }
2551
2552         return 0;
2553 }
2554
2555 int open_ctree(struct super_block *sb,
2556                struct btrfs_fs_devices *fs_devices,
2557                char *options)
2558 {
2559         u32 sectorsize;
2560         u32 nodesize;
2561         u32 stripesize;
2562         u64 generation;
2563         u64 features;
2564         struct btrfs_key location;
2565         struct buffer_head *bh;
2566         struct btrfs_super_block *disk_super;
2567         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2568         struct btrfs_root *tree_root;
2569         struct btrfs_root *chunk_root;
2570         int ret;
2571         int err = -EINVAL;
2572         int num_backups_tried = 0;
2573         int backup_index = 0;
2574         int max_active;
2575         int clear_free_space_tree = 0;
2576
2577         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2578         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2579         if (!tree_root || !chunk_root) {
2580                 err = -ENOMEM;
2581                 goto fail;
2582         }
2583
2584         ret = init_srcu_struct(&fs_info->subvol_srcu);
2585         if (ret) {
2586                 err = ret;
2587                 goto fail;
2588         }
2589
2590         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2591         if (ret) {
2592                 err = ret;
2593                 goto fail_srcu;
2594         }
2595         fs_info->dirty_metadata_batch = PAGE_SIZE *
2596                                         (1 + ilog2(nr_cpu_ids));
2597
2598         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2599         if (ret) {
2600                 err = ret;
2601                 goto fail_dirty_metadata_bytes;
2602         }
2603
2604         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2605         if (ret) {
2606                 err = ret;
2607                 goto fail_delalloc_bytes;
2608         }
2609
2610         fs_info->btree_inode = new_inode(sb);
2611         if (!fs_info->btree_inode) {
2612                 err = -ENOMEM;
2613                 goto fail_bio_counter;
2614         }
2615
2616         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2617
2618         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2619         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2620         INIT_LIST_HEAD(&fs_info->trans_list);
2621         INIT_LIST_HEAD(&fs_info->dead_roots);
2622         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2623         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2624         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2625         spin_lock_init(&fs_info->delalloc_root_lock);
2626         spin_lock_init(&fs_info->trans_lock);
2627         spin_lock_init(&fs_info->fs_roots_radix_lock);
2628         spin_lock_init(&fs_info->delayed_iput_lock);
2629         spin_lock_init(&fs_info->defrag_inodes_lock);
2630         spin_lock_init(&fs_info->tree_mod_seq_lock);
2631         spin_lock_init(&fs_info->super_lock);
2632         spin_lock_init(&fs_info->qgroup_op_lock);
2633         spin_lock_init(&fs_info->buffer_lock);
2634         spin_lock_init(&fs_info->unused_bgs_lock);
2635         rwlock_init(&fs_info->tree_mod_log_lock);
2636         mutex_init(&fs_info->unused_bg_unpin_mutex);
2637         mutex_init(&fs_info->delete_unused_bgs_mutex);
2638         mutex_init(&fs_info->reloc_mutex);
2639         mutex_init(&fs_info->delalloc_root_mutex);
2640         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2641         seqlock_init(&fs_info->profiles_lock);
2642
2643         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2644         INIT_LIST_HEAD(&fs_info->space_info);
2645         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2646         INIT_LIST_HEAD(&fs_info->unused_bgs);
2647         btrfs_mapping_init(&fs_info->mapping_tree);
2648         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2649                              BTRFS_BLOCK_RSV_GLOBAL);
2650         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2651                              BTRFS_BLOCK_RSV_DELALLOC);
2652         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2653         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2654         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2655         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2656                              BTRFS_BLOCK_RSV_DELOPS);
2657         atomic_set(&fs_info->nr_async_submits, 0);
2658         atomic_set(&fs_info->async_delalloc_pages, 0);
2659         atomic_set(&fs_info->async_submit_draining, 0);
2660         atomic_set(&fs_info->nr_async_bios, 0);
2661         atomic_set(&fs_info->defrag_running, 0);
2662         atomic_set(&fs_info->qgroup_op_seq, 0);
2663         atomic_set(&fs_info->reada_works_cnt, 0);
2664         atomic64_set(&fs_info->tree_mod_seq, 0);
2665         fs_info->sb = sb;
2666         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2667         fs_info->metadata_ratio = 0;
2668         fs_info->defrag_inodes = RB_ROOT;
2669         atomic64_set(&fs_info->free_chunk_space, 0);
2670         fs_info->tree_mod_log = RB_ROOT;
2671         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2672         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2673         /* readahead state */
2674         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2675         spin_lock_init(&fs_info->reada_lock);
2676
2677         fs_info->thread_pool_size = min_t(unsigned long,
2678                                           num_online_cpus() + 2, 8);
2679
2680         INIT_LIST_HEAD(&fs_info->ordered_roots);
2681         spin_lock_init(&fs_info->ordered_root_lock);
2682         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2683                                         GFP_KERNEL);
2684         if (!fs_info->delayed_root) {
2685                 err = -ENOMEM;
2686                 goto fail_iput;
2687         }
2688         btrfs_init_delayed_root(fs_info->delayed_root);
2689
2690         btrfs_init_scrub(fs_info);
2691 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2692         fs_info->check_integrity_print_mask = 0;
2693 #endif
2694         btrfs_init_balance(fs_info);
2695         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2696
2697         sb->s_blocksize = 4096;
2698         sb->s_blocksize_bits = blksize_bits(4096);
2699
2700         btrfs_init_btree_inode(fs_info);
2701
2702         spin_lock_init(&fs_info->block_group_cache_lock);
2703         fs_info->block_group_cache_tree = RB_ROOT;
2704         fs_info->first_logical_byte = (u64)-1;
2705
2706         extent_io_tree_init(&fs_info->freed_extents[0], NULL);
2707         extent_io_tree_init(&fs_info->freed_extents[1], NULL);
2708         fs_info->pinned_extents = &fs_info->freed_extents[0];
2709         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2710
2711         mutex_init(&fs_info->ordered_operations_mutex);
2712         mutex_init(&fs_info->tree_log_mutex);
2713         mutex_init(&fs_info->chunk_mutex);
2714         mutex_init(&fs_info->transaction_kthread_mutex);
2715         mutex_init(&fs_info->cleaner_mutex);
2716         mutex_init(&fs_info->volume_mutex);
2717         mutex_init(&fs_info->ro_block_group_mutex);
2718         init_rwsem(&fs_info->commit_root_sem);
2719         init_rwsem(&fs_info->cleanup_work_sem);
2720         init_rwsem(&fs_info->subvol_sem);
2721         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2722
2723         btrfs_init_dev_replace_locks(fs_info);
2724         btrfs_init_qgroup(fs_info);
2725
2726         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2727         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2728
2729         init_waitqueue_head(&fs_info->transaction_throttle);
2730         init_waitqueue_head(&fs_info->transaction_wait);
2731         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2732         init_waitqueue_head(&fs_info->async_submit_wait);
2733
2734         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2735
2736         /* Usable values until the real ones are cached from the superblock */
2737         fs_info->nodesize = 4096;
2738         fs_info->sectorsize = 4096;
2739         fs_info->stripesize = 4096;
2740
2741         ret = btrfs_alloc_stripe_hash_table(fs_info);
2742         if (ret) {
2743                 err = ret;
2744                 goto fail_alloc;
2745         }
2746
2747         __setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
2748
2749         invalidate_bdev(fs_devices->latest_bdev);
2750
2751         /*
2752          * Read super block and check the signature bytes only
2753          */
2754         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2755         if (IS_ERR(bh)) {
2756                 err = PTR_ERR(bh);
2757                 goto fail_alloc;
2758         }
2759
2760         /*
2761          * We want to check superblock checksum, the type is stored inside.
2762          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2763          */
2764         if (btrfs_check_super_csum(fs_info, bh->b_data)) {
2765                 btrfs_err(fs_info, "superblock checksum mismatch");
2766                 err = -EINVAL;
2767                 brelse(bh);
2768                 goto fail_alloc;
2769         }
2770
2771         /*
2772          * super_copy is zeroed at allocation time and we never touch the
2773          * following bytes up to INFO_SIZE, the checksum is calculated from
2774          * the whole block of INFO_SIZE
2775          */
2776         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2777         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2778                sizeof(*fs_info->super_for_commit));
2779         brelse(bh);
2780
2781         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2782
2783         ret = btrfs_check_super_valid(fs_info);
2784         if (ret) {
2785                 btrfs_err(fs_info, "superblock contains fatal errors");
2786                 err = -EINVAL;
2787                 goto fail_alloc;
2788         }
2789
2790         disk_super = fs_info->super_copy;
2791         if (!btrfs_super_root(disk_super))
2792                 goto fail_alloc;
2793
2794         /* check FS state, whether FS is broken. */
2795         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2796                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2797
2798         /*
2799          * run through our array of backup supers and setup
2800          * our ring pointer to the oldest one
2801          */
2802         generation = btrfs_super_generation(disk_super);
2803         find_oldest_super_backup(fs_info, generation);
2804
2805         /*
2806          * In the long term, we'll store the compression type in the super
2807          * block, and it'll be used for per file compression control.
2808          */
2809         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2810
2811         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
2812         if (ret) {
2813                 err = ret;
2814                 goto fail_alloc;
2815         }
2816
2817         features = btrfs_super_incompat_flags(disk_super) &
2818                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2819         if (features) {
2820                 btrfs_err(fs_info,
2821                     "cannot mount because of unsupported optional features (%llx)",
2822                     features);
2823                 err = -EINVAL;
2824                 goto fail_alloc;
2825         }
2826
2827         features = btrfs_super_incompat_flags(disk_super);
2828         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2829         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
2830                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2831
2832         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2833                 btrfs_info(fs_info, "has skinny extents");
2834
2835         /*
2836          * flag our filesystem as having big metadata blocks if
2837          * they are bigger than the page size
2838          */
2839         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2840                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2841                         btrfs_info(fs_info,
2842                                 "flagging fs with big metadata feature");
2843                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2844         }
2845
2846         nodesize = btrfs_super_nodesize(disk_super);
2847         sectorsize = btrfs_super_sectorsize(disk_super);
2848         stripesize = sectorsize;
2849         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2850         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2851
2852         /* Cache block sizes */
2853         fs_info->nodesize = nodesize;
2854         fs_info->sectorsize = sectorsize;
2855         fs_info->stripesize = stripesize;
2856
2857         /*
2858          * mixed block groups end up with duplicate but slightly offset
2859          * extent buffers for the same range.  It leads to corruptions
2860          */
2861         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2862             (sectorsize != nodesize)) {
2863                 btrfs_err(fs_info,
2864 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2865                         nodesize, sectorsize);
2866                 goto fail_alloc;
2867         }
2868
2869         /*
2870          * Needn't use the lock because there is no other task which will
2871          * update the flag.
2872          */
2873         btrfs_set_super_incompat_flags(disk_super, features);
2874
2875         features = btrfs_super_compat_ro_flags(disk_super) &
2876                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2877         if (!(sb->s_flags & MS_RDONLY) && features) {
2878                 btrfs_err(fs_info,
2879         "cannot mount read-write because of unsupported optional features (%llx)",
2880                        features);
2881                 err = -EINVAL;
2882                 goto fail_alloc;
2883         }
2884
2885         max_active = fs_info->thread_pool_size;
2886
2887         ret = btrfs_init_workqueues(fs_info, fs_devices);
2888         if (ret) {
2889                 err = ret;
2890                 goto fail_sb_buffer;
2891         }
2892
2893         sb->s_bdi->congested_fn = btrfs_congested_fn;
2894         sb->s_bdi->congested_data = fs_info;
2895         sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
2896         sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
2897         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
2898         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
2899
2900         sb->s_blocksize = sectorsize;
2901         sb->s_blocksize_bits = blksize_bits(sectorsize);
2902
2903         mutex_lock(&fs_info->chunk_mutex);
2904         ret = btrfs_read_sys_array(fs_info);
2905         mutex_unlock(&fs_info->chunk_mutex);
2906         if (ret) {
2907                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2908                 goto fail_sb_buffer;
2909         }
2910
2911         generation = btrfs_super_chunk_root_generation(disk_super);
2912
2913         __setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2914
2915         chunk_root->node = read_tree_block(fs_info,
2916                                            btrfs_super_chunk_root(disk_super),
2917                                            generation);
2918         if (IS_ERR(chunk_root->node) ||
2919             !extent_buffer_uptodate(chunk_root->node)) {
2920                 btrfs_err(fs_info, "failed to read chunk root");
2921                 if (!IS_ERR(chunk_root->node))
2922                         free_extent_buffer(chunk_root->node);
2923                 chunk_root->node = NULL;
2924                 goto fail_tree_roots;
2925         }
2926         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2927         chunk_root->commit_root = btrfs_root_node(chunk_root);
2928
2929         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2930            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2931
2932         ret = btrfs_read_chunk_tree(fs_info);
2933         if (ret) {
2934                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
2935                 goto fail_tree_roots;
2936         }
2937
2938         /*
2939          * keep the device that is marked to be the target device for the
2940          * dev_replace procedure
2941          */
2942         btrfs_close_extra_devices(fs_devices, 0);
2943
2944         if (!fs_devices->latest_bdev) {
2945                 btrfs_err(fs_info, "failed to read devices");
2946                 goto fail_tree_roots;
2947         }
2948
2949 retry_root_backup:
2950         generation = btrfs_super_generation(disk_super);
2951
2952         tree_root->node = read_tree_block(fs_info,
2953                                           btrfs_super_root(disk_super),
2954                                           generation);
2955         if (IS_ERR(tree_root->node) ||
2956             !extent_buffer_uptodate(tree_root->node)) {
2957                 btrfs_warn(fs_info, "failed to read tree root");
2958                 if (!IS_ERR(tree_root->node))
2959                         free_extent_buffer(tree_root->node);
2960                 tree_root->node = NULL;
2961                 goto recovery_tree_root;
2962         }
2963
2964         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2965         tree_root->commit_root = btrfs_root_node(tree_root);
2966         btrfs_set_root_refs(&tree_root->root_item, 1);
2967
2968         mutex_lock(&tree_root->objectid_mutex);
2969         ret = btrfs_find_highest_objectid(tree_root,
2970                                         &tree_root->highest_objectid);
2971         if (ret) {
2972                 mutex_unlock(&tree_root->objectid_mutex);
2973                 goto recovery_tree_root;
2974         }
2975
2976         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
2977
2978         mutex_unlock(&tree_root->objectid_mutex);
2979
2980         ret = btrfs_read_roots(fs_info);
2981         if (ret)
2982                 goto recovery_tree_root;
2983
2984         fs_info->generation = generation;
2985         fs_info->last_trans_committed = generation;
2986
2987         ret = btrfs_recover_balance(fs_info);
2988         if (ret) {
2989                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
2990                 goto fail_block_groups;
2991         }
2992
2993         ret = btrfs_init_dev_stats(fs_info);
2994         if (ret) {
2995                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
2996                 goto fail_block_groups;
2997         }
2998
2999         ret = btrfs_init_dev_replace(fs_info);
3000         if (ret) {
3001                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3002                 goto fail_block_groups;
3003         }
3004
3005         btrfs_close_extra_devices(fs_devices, 1);
3006
3007         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
3008         if (ret) {
3009                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3010                                 ret);
3011                 goto fail_block_groups;
3012         }
3013
3014         ret = btrfs_sysfs_add_device(fs_devices);
3015         if (ret) {
3016                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
3017                                 ret);
3018                 goto fail_fsdev_sysfs;
3019         }
3020
3021         ret = btrfs_sysfs_add_mounted(fs_info);
3022         if (ret) {
3023                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3024                 goto fail_fsdev_sysfs;
3025         }
3026
3027         ret = btrfs_init_space_info(fs_info);
3028         if (ret) {
3029                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3030                 goto fail_sysfs;
3031         }
3032
3033         ret = btrfs_read_block_groups(fs_info);
3034         if (ret) {
3035                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3036                 goto fail_sysfs;
3037         }
3038         fs_info->num_tolerated_disk_barrier_failures =
3039                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3040         if (fs_info->fs_devices->missing_devices >
3041              fs_info->num_tolerated_disk_barrier_failures &&
3042             !(sb->s_flags & MS_RDONLY)) {
3043                 btrfs_warn(fs_info,
3044 "missing devices (%llu) exceeds the limit (%d), writeable mount is not allowed",
3045                         fs_info->fs_devices->missing_devices,
3046                         fs_info->num_tolerated_disk_barrier_failures);
3047                 goto fail_sysfs;
3048         }
3049
3050         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3051                                                "btrfs-cleaner");
3052         if (IS_ERR(fs_info->cleaner_kthread))
3053                 goto fail_sysfs;
3054
3055         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3056                                                    tree_root,
3057                                                    "btrfs-transaction");
3058         if (IS_ERR(fs_info->transaction_kthread))
3059                 goto fail_cleaner;
3060
3061         if (!btrfs_test_opt(fs_info, SSD) &&
3062             !btrfs_test_opt(fs_info, NOSSD) &&
3063             !fs_info->fs_devices->rotating) {
3064                 btrfs_info(fs_info, "detected SSD devices, enabling SSD mode");
3065                 btrfs_set_opt(fs_info->mount_opt, SSD);
3066         }
3067
3068         /*
3069          * Mount does not set all options immediately, we can do it now and do
3070          * not have to wait for transaction commit
3071          */
3072         btrfs_apply_pending_changes(fs_info);
3073
3074 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3075         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3076                 ret = btrfsic_mount(fs_info, fs_devices,
3077                                     btrfs_test_opt(fs_info,
3078                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3079                                     1 : 0,
3080                                     fs_info->check_integrity_print_mask);
3081                 if (ret)
3082                         btrfs_warn(fs_info,
3083                                 "failed to initialize integrity check module: %d",
3084                                 ret);
3085         }
3086 #endif
3087         ret = btrfs_read_qgroup_config(fs_info);
3088         if (ret)
3089                 goto fail_trans_kthread;
3090
3091         /* do not make disk changes in broken FS or nologreplay is given */
3092         if (btrfs_super_log_root(disk_super) != 0 &&
3093             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3094                 ret = btrfs_replay_log(fs_info, fs_devices);
3095                 if (ret) {
3096                         err = ret;
3097                         goto fail_qgroup;
3098                 }
3099         }
3100
3101         ret = btrfs_find_orphan_roots(fs_info);
3102         if (ret)
3103                 goto fail_qgroup;
3104
3105         if (!(sb->s_flags & MS_RDONLY)) {
3106                 ret = btrfs_cleanup_fs_roots(fs_info);
3107                 if (ret)
3108                         goto fail_qgroup;
3109
3110                 mutex_lock(&fs_info->cleaner_mutex);
3111                 ret = btrfs_recover_relocation(tree_root);
3112                 mutex_unlock(&fs_info->cleaner_mutex);
3113                 if (ret < 0) {
3114                         btrfs_warn(fs_info, "failed to recover relocation: %d",
3115                                         ret);
3116                         err = -EINVAL;
3117                         goto fail_qgroup;
3118                 }
3119         }
3120
3121         location.objectid = BTRFS_FS_TREE_OBJECTID;
3122         location.type = BTRFS_ROOT_ITEM_KEY;
3123         location.offset = 0;
3124
3125         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3126         if (IS_ERR(fs_info->fs_root)) {
3127                 err = PTR_ERR(fs_info->fs_root);
3128                 goto fail_qgroup;
3129         }
3130
3131         if (sb->s_flags & MS_RDONLY)
3132                 return 0;
3133
3134         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3135             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3136                 clear_free_space_tree = 1;
3137         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3138                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3139                 btrfs_warn(fs_info, "free space tree is invalid");
3140                 clear_free_space_tree = 1;
3141         }
3142
3143         if (clear_free_space_tree) {
3144                 btrfs_info(fs_info, "clearing free space tree");
3145                 ret = btrfs_clear_free_space_tree(fs_info);
3146                 if (ret) {
3147                         btrfs_warn(fs_info,
3148                                    "failed to clear free space tree: %d", ret);
3149                         close_ctree(fs_info);
3150                         return ret;
3151                 }
3152         }
3153
3154         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3155             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3156                 btrfs_info(fs_info, "creating free space tree");
3157                 ret = btrfs_create_free_space_tree(fs_info);
3158                 if (ret) {
3159                         btrfs_warn(fs_info,
3160                                 "failed to create free space tree: %d", ret);
3161                         close_ctree(fs_info);
3162                         return ret;
3163                 }
3164         }
3165
3166         down_read(&fs_info->cleanup_work_sem);
3167         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3168             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3169                 up_read(&fs_info->cleanup_work_sem);
3170                 close_ctree(fs_info);
3171                 return ret;
3172         }
3173         up_read(&fs_info->cleanup_work_sem);
3174
3175         ret = btrfs_resume_balance_async(fs_info);
3176         if (ret) {
3177                 btrfs_warn(fs_info, "failed to resume balance: %d", ret);
3178                 close_ctree(fs_info);
3179                 return ret;
3180         }
3181
3182         ret = btrfs_resume_dev_replace_async(fs_info);
3183         if (ret) {
3184                 btrfs_warn(fs_info, "failed to resume device replace: %d", ret);
3185                 close_ctree(fs_info);
3186                 return ret;
3187         }
3188
3189         btrfs_qgroup_rescan_resume(fs_info);
3190
3191         if (!fs_info->uuid_root) {
3192                 btrfs_info(fs_info, "creating UUID tree");
3193                 ret = btrfs_create_uuid_tree(fs_info);
3194                 if (ret) {
3195                         btrfs_warn(fs_info,
3196                                 "failed to create the UUID tree: %d", ret);
3197                         close_ctree(fs_info);
3198                         return ret;
3199                 }
3200         } else if (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3201                    fs_info->generation !=
3202                                 btrfs_super_uuid_tree_generation(disk_super)) {
3203                 btrfs_info(fs_info, "checking UUID tree");
3204                 ret = btrfs_check_uuid_tree(fs_info);
3205                 if (ret) {
3206                         btrfs_warn(fs_info,
3207                                 "failed to check the UUID tree: %d", ret);
3208                         close_ctree(fs_info);
3209                         return ret;
3210                 }
3211         } else {
3212                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3213         }
3214         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3215
3216         /*
3217          * backuproot only affect mount behavior, and if open_ctree succeeded,
3218          * no need to keep the flag
3219          */
3220         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3221
3222         return 0;
3223
3224 fail_qgroup:
3225         btrfs_free_qgroup_config(fs_info);
3226 fail_trans_kthread:
3227         kthread_stop(fs_info->transaction_kthread);
3228         btrfs_cleanup_transaction(fs_info);
3229         btrfs_free_fs_roots(fs_info);
3230 fail_cleaner:
3231         kthread_stop(fs_info->cleaner_kthread);
3232
3233         /*
3234          * make sure we're done with the btree inode before we stop our
3235          * kthreads
3236          */
3237         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3238
3239 fail_sysfs:
3240         btrfs_sysfs_remove_mounted(fs_info);
3241
3242 fail_fsdev_sysfs:
3243         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3244
3245 fail_block_groups:
3246         btrfs_put_block_group_cache(fs_info);
3247
3248 fail_tree_roots:
3249         free_root_pointers(fs_info, 1);
3250         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3251
3252 fail_sb_buffer:
3253         btrfs_stop_all_workers(fs_info);
3254         btrfs_free_block_groups(fs_info);
3255 fail_alloc:
3256 fail_iput:
3257         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3258
3259         iput(fs_info->btree_inode);
3260 fail_bio_counter:
3261         percpu_counter_destroy(&fs_info->bio_counter);