Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[muen/linux.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         int error;
91         enum btrfs_wq_endio_type metadata;
92         struct list_head list;
93         struct btrfs_work work;
94 };
95
96 static struct kmem_cache *btrfs_end_io_wq_cache;
97
98 int __init btrfs_end_io_wq_init(void)
99 {
100         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
101                                         sizeof(struct btrfs_end_io_wq),
102                                         0,
103                                         SLAB_MEM_SPREAD,
104                                         NULL);
105         if (!btrfs_end_io_wq_cache)
106                 return -ENOMEM;
107         return 0;
108 }
109
110 void btrfs_end_io_wq_exit(void)
111 {
112         kmem_cache_destroy(btrfs_end_io_wq_cache);
113 }
114
115 /*
116  * async submit bios are used to offload expensive checksumming
117  * onto the worker threads.  They checksum file and metadata bios
118  * just before they are sent down the IO stack.
119  */
120 struct async_submit_bio {
121         struct inode *inode;
122         struct bio *bio;
123         struct list_head list;
124         extent_submit_bio_hook_t *submit_bio_start;
125         extent_submit_bio_hook_t *submit_bio_done;
126         int mirror_num;
127         unsigned long bio_flags;
128         /*
129          * bio_offset is optional, can be used if the pages in the bio
130          * can't tell us where in the file the bio should go
131          */
132         u64 bio_offset;
133         struct btrfs_work work;
134         int error;
135 };
136
137 /*
138  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
139  * eb, the lockdep key is determined by the btrfs_root it belongs to and
140  * the level the eb occupies in the tree.
141  *
142  * Different roots are used for different purposes and may nest inside each
143  * other and they require separate keysets.  As lockdep keys should be
144  * static, assign keysets according to the purpose of the root as indicated
145  * by btrfs_root->objectid.  This ensures that all special purpose roots
146  * have separate keysets.
147  *
148  * Lock-nesting across peer nodes is always done with the immediate parent
149  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
150  * subclass to avoid triggering lockdep warning in such cases.
151  *
152  * The key is set by the readpage_end_io_hook after the buffer has passed
153  * csum validation but before the pages are unlocked.  It is also set by
154  * btrfs_init_new_buffer on freshly allocated blocks.
155  *
156  * We also add a check to make sure the highest level of the tree is the
157  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
158  * needs update as well.
159  */
160 #ifdef CONFIG_DEBUG_LOCK_ALLOC
161 # if BTRFS_MAX_LEVEL != 8
162 #  error
163 # endif
164
165 static struct btrfs_lockdep_keyset {
166         u64                     id;             /* root objectid */
167         const char              *name_stem;     /* lock name stem */
168         char                    names[BTRFS_MAX_LEVEL + 1][20];
169         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
170 } btrfs_lockdep_keysets[] = {
171         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
172         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
173         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
174         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
175         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
176         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
177         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
178         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
179         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
180         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
181         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
182         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
183         { .id = 0,                              .name_stem = "tree"     },
184 };
185
186 void __init btrfs_init_lockdep(void)
187 {
188         int i, j;
189
190         /* initialize lockdep class names */
191         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
192                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
193
194                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
195                         snprintf(ks->names[j], sizeof(ks->names[j]),
196                                  "btrfs-%s-%02d", ks->name_stem, j);
197         }
198 }
199
200 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
201                                     int level)
202 {
203         struct btrfs_lockdep_keyset *ks;
204
205         BUG_ON(level >= ARRAY_SIZE(ks->keys));
206
207         /* find the matching keyset, id 0 is the default entry */
208         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
209                 if (ks->id == objectid)
210                         break;
211
212         lockdep_set_class_and_name(&eb->lock,
213                                    &ks->keys[level], ks->names[level]);
214 }
215
216 #endif
217
218 /*
219  * extents on the btree inode are pretty simple, there's one extent
220  * that covers the entire device
221  */
222 static struct extent_map *btree_get_extent(struct btrfs_inode *inode,
223                 struct page *page, size_t pg_offset, u64 start, u64 len,
224                 int create)
225 {
226         struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
227         struct extent_map_tree *em_tree = &inode->extent_tree;
228         struct extent_map *em;
229         int ret;
230
231         read_lock(&em_tree->lock);
232         em = lookup_extent_mapping(em_tree, start, len);
233         if (em) {
234                 em->bdev = fs_info->fs_devices->latest_bdev;
235                 read_unlock(&em_tree->lock);
236                 goto out;
237         }
238         read_unlock(&em_tree->lock);
239
240         em = alloc_extent_map();
241         if (!em) {
242                 em = ERR_PTR(-ENOMEM);
243                 goto out;
244         }
245         em->start = 0;
246         em->len = (u64)-1;
247         em->block_len = (u64)-1;
248         em->block_start = 0;
249         em->bdev = fs_info->fs_devices->latest_bdev;
250
251         write_lock(&em_tree->lock);
252         ret = add_extent_mapping(em_tree, em, 0);
253         if (ret == -EEXIST) {
254                 free_extent_map(em);
255                 em = lookup_extent_mapping(em_tree, start, len);
256                 if (!em)
257                         em = ERR_PTR(-EIO);
258         } else if (ret) {
259                 free_extent_map(em);
260                 em = ERR_PTR(ret);
261         }
262         write_unlock(&em_tree->lock);
263
264 out:
265         return em;
266 }
267
268 u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
269 {
270         return btrfs_crc32c(seed, data, len);
271 }
272
273 void btrfs_csum_final(u32 crc, u8 *result)
274 {
275         put_unaligned_le32(~crc, result);
276 }
277
278 /*
279  * compute the csum for a btree block, and either verify it or write it
280  * into the csum field of the block.
281  */
282 static int csum_tree_block(struct btrfs_fs_info *fs_info,
283                            struct extent_buffer *buf,
284                            int verify)
285 {
286         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
287         char *result = NULL;
288         unsigned long len;
289         unsigned long cur_len;
290         unsigned long offset = BTRFS_CSUM_SIZE;
291         char *kaddr;
292         unsigned long map_start;
293         unsigned long map_len;
294         int err;
295         u32 crc = ~(u32)0;
296         unsigned long inline_result;
297
298         len = buf->len - offset;
299         while (len > 0) {
300                 err = map_private_extent_buffer(buf, offset, 32,
301                                         &kaddr, &map_start, &map_len);
302                 if (err)
303                         return err;
304                 cur_len = min(len, map_len - (offset - map_start));
305                 crc = btrfs_csum_data(kaddr + offset - map_start,
306                                       crc, cur_len);
307                 len -= cur_len;
308                 offset += cur_len;
309         }
310         if (csum_size > sizeof(inline_result)) {
311                 result = kzalloc(csum_size, GFP_NOFS);
312                 if (!result)
313                         return -ENOMEM;
314         } else {
315                 result = (char *)&inline_result;
316         }
317
318         btrfs_csum_final(crc, result);
319
320         if (verify) {
321                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
322                         u32 val;
323                         u32 found = 0;
324                         memcpy(&found, result, csum_size);
325
326                         read_extent_buffer(buf, &val, 0, csum_size);
327                         btrfs_warn_rl(fs_info,
328                                 "%s checksum verify failed on %llu wanted %X found %X level %d",
329                                 fs_info->sb->s_id, buf->start,
330                                 val, found, btrfs_header_level(buf));
331                         if (result != (char *)&inline_result)
332                                 kfree(result);
333                         return -EUCLEAN;
334                 }
335         } else {
336                 write_extent_buffer(buf, result, 0, csum_size);
337         }
338         if (result != (char *)&inline_result)
339                 kfree(result);
340         return 0;
341 }
342
343 /*
344  * we can't consider a given block up to date unless the transid of the
345  * block matches the transid in the parent node's pointer.  This is how we
346  * detect blocks that either didn't get written at all or got written
347  * in the wrong place.
348  */
349 static int verify_parent_transid(struct extent_io_tree *io_tree,
350                                  struct extent_buffer *eb, u64 parent_transid,
351                                  int atomic)
352 {
353         struct extent_state *cached_state = NULL;
354         int ret;
355         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
356
357         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
358                 return 0;
359
360         if (atomic)
361                 return -EAGAIN;
362
363         if (need_lock) {
364                 btrfs_tree_read_lock(eb);
365                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
366         }
367
368         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
369                          &cached_state);
370         if (extent_buffer_uptodate(eb) &&
371             btrfs_header_generation(eb) == parent_transid) {
372                 ret = 0;
373                 goto out;
374         }
375         btrfs_err_rl(eb->fs_info,
376                 "parent transid verify failed on %llu wanted %llu found %llu",
377                         eb->start,
378                         parent_transid, btrfs_header_generation(eb));
379         ret = 1;
380
381         /*
382          * Things reading via commit roots that don't have normal protection,
383          * like send, can have a really old block in cache that may point at a
384          * block that has been freed and re-allocated.  So don't clear uptodate
385          * if we find an eb that is under IO (dirty/writeback) because we could
386          * end up reading in the stale data and then writing it back out and
387          * making everybody very sad.
388          */
389         if (!extent_buffer_under_io(eb))
390                 clear_extent_buffer_uptodate(eb);
391 out:
392         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
393                              &cached_state, GFP_NOFS);
394         if (need_lock)
395                 btrfs_tree_read_unlock_blocking(eb);
396         return ret;
397 }
398
399 /*
400  * Return 0 if the superblock checksum type matches the checksum value of that
401  * algorithm. Pass the raw disk superblock data.
402  */
403 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
404                                   char *raw_disk_sb)
405 {
406         struct btrfs_super_block *disk_sb =
407                 (struct btrfs_super_block *)raw_disk_sb;
408         u16 csum_type = btrfs_super_csum_type(disk_sb);
409         int ret = 0;
410
411         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
412                 u32 crc = ~(u32)0;
413                 const int csum_size = sizeof(crc);
414                 char result[csum_size];
415
416                 /*
417                  * The super_block structure does not span the whole
418                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
419                  * is filled with zeros and is included in the checksum.
420                  */
421                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
422                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
423                 btrfs_csum_final(crc, result);
424
425                 if (memcmp(raw_disk_sb, result, csum_size))
426                         ret = 1;
427         }
428
429         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
430                 btrfs_err(fs_info, "unsupported checksum algorithm %u",
431                                 csum_type);
432                 ret = 1;
433         }
434
435         return ret;
436 }
437
438 /*
439  * helper to read a given tree block, doing retries as required when
440  * the checksums don't match and we have alternate mirrors to try.
441  */
442 static int btree_read_extent_buffer_pages(struct btrfs_fs_info *fs_info,
443                                           struct extent_buffer *eb,
444                                           u64 parent_transid)
445 {
446         struct extent_io_tree *io_tree;
447         int failed = 0;
448         int ret;
449         int num_copies = 0;
450         int mirror_num = 0;
451         int failed_mirror = 0;
452
453         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
454         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
455         while (1) {
456                 ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
457                                                btree_get_extent, mirror_num);
458                 if (!ret) {
459                         if (!verify_parent_transid(io_tree, eb,
460                                                    parent_transid, 0))
461                                 break;
462                         else
463                                 ret = -EIO;
464                 }
465
466                 /*
467                  * This buffer's crc is fine, but its contents are corrupted, so
468                  * there is no reason to read the other copies, they won't be
469                  * any less wrong.
470                  */
471                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
472                         break;
473
474                 num_copies = btrfs_num_copies(fs_info,
475                                               eb->start, eb->len);
476                 if (num_copies == 1)
477                         break;
478
479                 if (!failed_mirror) {
480                         failed = 1;
481                         failed_mirror = eb->read_mirror;
482                 }
483
484                 mirror_num++;
485                 if (mirror_num == failed_mirror)
486                         mirror_num++;
487
488                 if (mirror_num > num_copies)
489                         break;
490         }
491
492         if (failed && !ret && failed_mirror)
493                 repair_eb_io_failure(fs_info, eb, failed_mirror);
494
495         return ret;
496 }
497
498 /*
499  * checksum a dirty tree block before IO.  This has extra checks to make sure
500  * we only fill in the checksum field in the first page of a multi-page block
501  */
502
503 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
504 {
505         u64 start = page_offset(page);
506         u64 found_start;
507         struct extent_buffer *eb;
508
509         eb = (struct extent_buffer *)page->private;
510         if (page != eb->pages[0])
511                 return 0;
512
513         found_start = btrfs_header_bytenr(eb);
514         /*
515          * Please do not consolidate these warnings into a single if.
516          * It is useful to know what went wrong.
517          */
518         if (WARN_ON(found_start != start))
519                 return -EUCLEAN;
520         if (WARN_ON(!PageUptodate(page)))
521                 return -EUCLEAN;
522
523         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
524                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
525
526         return csum_tree_block(fs_info, eb, 0);
527 }
528
529 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
530                                  struct extent_buffer *eb)
531 {
532         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
533         u8 fsid[BTRFS_UUID_SIZE];
534         int ret = 1;
535
536         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
537         while (fs_devices) {
538                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
539                         ret = 0;
540                         break;
541                 }
542                 fs_devices = fs_devices->seed;
543         }
544         return ret;
545 }
546
547 #define CORRUPT(reason, eb, root, slot)                                 \
548         btrfs_crit(root->fs_info,                                       \
549                    "corrupt %s, %s: block=%llu, root=%llu, slot=%d",    \
550                    btrfs_header_level(eb) == 0 ? "leaf" : "node",       \
551                    reason, btrfs_header_bytenr(eb), root->objectid, slot)
552
553 static noinline int check_leaf(struct btrfs_root *root,
554                                struct extent_buffer *leaf)
555 {
556         struct btrfs_fs_info *fs_info = root->fs_info;
557         struct btrfs_key key;
558         struct btrfs_key leaf_key;
559         u32 nritems = btrfs_header_nritems(leaf);
560         int slot;
561
562         /*
563          * Extent buffers from a relocation tree have a owner field that
564          * corresponds to the subvolume tree they are based on. So just from an
565          * extent buffer alone we can not find out what is the id of the
566          * corresponding subvolume tree, so we can not figure out if the extent
567          * buffer corresponds to the root of the relocation tree or not. So skip
568          * this check for relocation trees.
569          */
570         if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
571                 struct btrfs_root *check_root;
572
573                 key.objectid = btrfs_header_owner(leaf);
574                 key.type = BTRFS_ROOT_ITEM_KEY;
575                 key.offset = (u64)-1;
576
577                 check_root = btrfs_get_fs_root(fs_info, &key, false);
578                 /*
579                  * The only reason we also check NULL here is that during
580                  * open_ctree() some roots has not yet been set up.
581                  */
582                 if (!IS_ERR_OR_NULL(check_root)) {
583                         struct extent_buffer *eb;
584
585                         eb = btrfs_root_node(check_root);
586                         /* if leaf is the root, then it's fine */
587                         if (leaf != eb) {
588                                 CORRUPT("non-root leaf's nritems is 0",
589                                         leaf, check_root, 0);
590                                 free_extent_buffer(eb);
591                                 return -EIO;
592                         }
593                         free_extent_buffer(eb);
594                 }
595                 return 0;
596         }
597
598         if (nritems == 0)
599                 return 0;
600
601         /* Check the 0 item */
602         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
603             BTRFS_LEAF_DATA_SIZE(fs_info)) {
604                 CORRUPT("invalid item offset size pair", leaf, root, 0);
605                 return -EIO;
606         }
607
608         /*
609          * Check to make sure each items keys are in the correct order and their
610          * offsets make sense.  We only have to loop through nritems-1 because
611          * we check the current slot against the next slot, which verifies the
612          * next slot's offset+size makes sense and that the current's slot
613          * offset is correct.
614          */
615         for (slot = 0; slot < nritems - 1; slot++) {
616                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
617                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
618
619                 /* Make sure the keys are in the right order */
620                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
621                         CORRUPT("bad key order", leaf, root, slot);
622                         return -EIO;
623                 }
624
625                 /*
626                  * Make sure the offset and ends are right, remember that the
627                  * item data starts at the end of the leaf and grows towards the
628                  * front.
629                  */
630                 if (btrfs_item_offset_nr(leaf, slot) !=
631                         btrfs_item_end_nr(leaf, slot + 1)) {
632                         CORRUPT("slot offset bad", leaf, root, slot);
633                         return -EIO;
634                 }
635
636                 /*
637                  * Check to make sure that we don't point outside of the leaf,
638                  * just in case all the items are consistent to each other, but
639                  * all point outside of the leaf.
640                  */
641                 if (btrfs_item_end_nr(leaf, slot) >
642                     BTRFS_LEAF_DATA_SIZE(fs_info)) {
643                         CORRUPT("slot end outside of leaf", leaf, root, slot);
644                         return -EIO;
645                 }
646         }
647
648         return 0;
649 }
650
651 static int check_node(struct btrfs_root *root, struct extent_buffer *node)
652 {
653         unsigned long nr = btrfs_header_nritems(node);
654         struct btrfs_key key, next_key;
655         int slot;
656         u64 bytenr;
657         int ret = 0;
658
659         if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root->fs_info)) {
660                 btrfs_crit(root->fs_info,
661                            "corrupt node: block %llu root %llu nritems %lu",
662                            node->start, root->objectid, nr);
663                 return -EIO;
664         }
665
666         for (slot = 0; slot < nr - 1; slot++) {
667                 bytenr = btrfs_node_blockptr(node, slot);
668                 btrfs_node_key_to_cpu(node, &key, slot);
669                 btrfs_node_key_to_cpu(node, &next_key, slot + 1);
670
671                 if (!bytenr) {
672                         CORRUPT("invalid item slot", node, root, slot);
673                         ret = -EIO;
674                         goto out;
675                 }
676
677                 if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
678                         CORRUPT("bad key order", node, root, slot);
679                         ret = -EIO;
680                         goto out;
681                 }
682         }
683 out:
684         return ret;
685 }
686
687 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
688                                       u64 phy_offset, struct page *page,
689                                       u64 start, u64 end, int mirror)
690 {
691         u64 found_start;
692         int found_level;
693         struct extent_buffer *eb;
694         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
695         struct btrfs_fs_info *fs_info = root->fs_info;
696         int ret = 0;
697         int reads_done;
698
699         if (!page->private)
700                 goto out;
701
702         eb = (struct extent_buffer *)page->private;
703
704         /* the pending IO might have been the only thing that kept this buffer
705          * in memory.  Make sure we have a ref for all this other checks
706          */
707         extent_buffer_get(eb);
708
709         reads_done = atomic_dec_and_test(&eb->io_pages);
710         if (!reads_done)
711                 goto err;
712
713         eb->read_mirror = mirror;
714         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
715                 ret = -EIO;
716                 goto err;
717         }
718
719         found_start = btrfs_header_bytenr(eb);
720         if (found_start != eb->start) {
721                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
722                              found_start, eb->start);
723                 ret = -EIO;
724                 goto err;
725         }
726         if (check_tree_block_fsid(fs_info, eb)) {
727                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
728                              eb->start);
729                 ret = -EIO;
730                 goto err;
731         }
732         found_level = btrfs_header_level(eb);
733         if (found_level >= BTRFS_MAX_LEVEL) {
734                 btrfs_err(fs_info, "bad tree block level %d",
735                           (int)btrfs_header_level(eb));
736                 ret = -EIO;
737                 goto err;
738         }
739
740         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
741                                        eb, found_level);
742
743         ret = csum_tree_block(fs_info, eb, 1);
744         if (ret)
745                 goto err;
746
747         /*
748          * If this is a leaf block and it is corrupt, set the corrupt bit so
749          * that we don't try and read the other copies of this block, just
750          * return -EIO.
751          */
752         if (found_level == 0 && check_leaf(root, eb)) {
753                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
754                 ret = -EIO;
755         }
756
757         if (found_level > 0 && check_node(root, eb))
758                 ret = -EIO;
759
760         if (!ret)
761                 set_extent_buffer_uptodate(eb);
762 err:
763         if (reads_done &&
764             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
765                 btree_readahead_hook(fs_info, eb, ret);
766
767         if (ret) {
768                 /*
769                  * our io error hook is going to dec the io pages
770                  * again, we have to make sure it has something
771                  * to decrement
772                  */
773                 atomic_inc(&eb->io_pages);
774                 clear_extent_buffer_uptodate(eb);
775         }
776         free_extent_buffer(eb);
777 out:
778         return ret;
779 }
780
781 static int btree_io_failed_hook(struct page *page, int failed_mirror)
782 {
783         struct extent_buffer *eb;
784
785         eb = (struct extent_buffer *)page->private;
786         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
787         eb->read_mirror = failed_mirror;
788         atomic_dec(&eb->io_pages);
789         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
790                 btree_readahead_hook(eb->fs_info, eb, -EIO);
791         return -EIO;    /* we fixed nothing */
792 }
793
794 static void end_workqueue_bio(struct bio *bio)
795 {
796         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
797         struct btrfs_fs_info *fs_info;
798         struct btrfs_workqueue *wq;
799         btrfs_work_func_t func;
800
801         fs_info = end_io_wq->info;
802         end_io_wq->error = bio->bi_error;
803
804         if (bio_op(bio) == REQ_OP_WRITE) {
805                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
806                         wq = fs_info->endio_meta_write_workers;
807                         func = btrfs_endio_meta_write_helper;
808                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
809                         wq = fs_info->endio_freespace_worker;
810                         func = btrfs_freespace_write_helper;
811                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
812                         wq = fs_info->endio_raid56_workers;
813                         func = btrfs_endio_raid56_helper;
814                 } else {
815                         wq = fs_info->endio_write_workers;
816                         func = btrfs_endio_write_helper;
817                 }
818         } else {
819                 if (unlikely(end_io_wq->metadata ==
820                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
821                         wq = fs_info->endio_repair_workers;
822                         func = btrfs_endio_repair_helper;
823                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
824                         wq = fs_info->endio_raid56_workers;
825                         func = btrfs_endio_raid56_helper;
826                 } else if (end_io_wq->metadata) {
827                         wq = fs_info->endio_meta_workers;
828                         func = btrfs_endio_meta_helper;
829                 } else {
830                         wq = fs_info->endio_workers;
831                         func = btrfs_endio_helper;
832                 }
833         }
834
835         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
836         btrfs_queue_work(wq, &end_io_wq->work);
837 }
838
839 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
840                         enum btrfs_wq_endio_type metadata)
841 {
842         struct btrfs_end_io_wq *end_io_wq;
843
844         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
845         if (!end_io_wq)
846                 return -ENOMEM;
847
848         end_io_wq->private = bio->bi_private;
849         end_io_wq->end_io = bio->bi_end_io;
850         end_io_wq->info = info;
851         end_io_wq->error = 0;
852         end_io_wq->bio = bio;
853         end_io_wq->metadata = metadata;
854
855         bio->bi_private = end_io_wq;
856         bio->bi_end_io = end_workqueue_bio;
857         return 0;
858 }
859
860 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
861 {
862         unsigned long limit = min_t(unsigned long,
863                                     info->thread_pool_size,
864                                     info->fs_devices->open_devices);
865         return 256 * limit;
866 }
867
868 static void run_one_async_start(struct btrfs_work *work)
869 {
870         struct async_submit_bio *async;
871         int ret;
872
873         async = container_of(work, struct  async_submit_bio, work);
874         ret = async->submit_bio_start(async->inode, async->bio,
875                                       async->mirror_num, async->bio_flags,
876                                       async->bio_offset);
877         if (ret)
878                 async->error = ret;
879 }
880
881 static void run_one_async_done(struct btrfs_work *work)
882 {
883         struct btrfs_fs_info *fs_info;
884         struct async_submit_bio *async;
885         int limit;
886
887         async = container_of(work, struct  async_submit_bio, work);
888         fs_info = BTRFS_I(async->inode)->root->fs_info;
889
890         limit = btrfs_async_submit_limit(fs_info);
891         limit = limit * 2 / 3;
892
893         /*
894          * atomic_dec_return implies a barrier for waitqueue_active
895          */
896         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
897             waitqueue_active(&fs_info->async_submit_wait))
898                 wake_up(&fs_info->async_submit_wait);
899
900         /* If an error occurred we just want to clean up the bio and move on */
901         if (async->error) {
902                 async->bio->bi_error = async->error;
903                 bio_endio(async->bio);
904                 return;
905         }
906
907         async->submit_bio_done(async->inode, async->bio, async->mirror_num,
908                                async->bio_flags, async->bio_offset);
909 }
910
911 static void run_one_async_free(struct btrfs_work *work)
912 {
913         struct async_submit_bio *async;
914
915         async = container_of(work, struct  async_submit_bio, work);
916         kfree(async);
917 }
918
919 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
920                         struct bio *bio, int mirror_num,
921                         unsigned long bio_flags,
922                         u64 bio_offset,
923                         extent_submit_bio_hook_t *submit_bio_start,
924                         extent_submit_bio_hook_t *submit_bio_done)
925 {
926         struct async_submit_bio *async;
927
928         async = kmalloc(sizeof(*async), GFP_NOFS);
929         if (!async)
930                 return -ENOMEM;
931
932         async->inode = inode;
933         async->bio = bio;
934         async->mirror_num = mirror_num;
935         async->submit_bio_start = submit_bio_start;
936         async->submit_bio_done = submit_bio_done;
937
938         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
939                         run_one_async_done, run_one_async_free);
940
941         async->bio_flags = bio_flags;
942         async->bio_offset = bio_offset;
943
944         async->error = 0;
945
946         atomic_inc(&fs_info->nr_async_submits);
947
948         if (op_is_sync(bio->bi_opf))
949                 btrfs_set_work_high_priority(&async->work);
950
951         btrfs_queue_work(fs_info->workers, &async->work);
952
953         while (atomic_read(&fs_info->async_submit_draining) &&
954               atomic_read(&fs_info->nr_async_submits)) {
955                 wait_event(fs_info->async_submit_wait,
956                            (atomic_read(&fs_info->nr_async_submits) == 0));
957         }
958
959         return 0;
960 }
961
962 static int btree_csum_one_bio(struct bio *bio)
963 {
964         struct bio_vec *bvec;
965         struct btrfs_root *root;
966         int i, ret = 0;
967
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 ret;
976 }
977
978 static int __btree_submit_bio_start(struct inode *inode, 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 int __btree_submit_bio_done(struct inode *inode, struct bio *bio,
990                                  int mirror_num, unsigned long bio_flags,
991                                  u64 bio_offset)
992 {
993         int ret;
994
995         /*
996          * when we're called for a write, we're already in the async
997          * submission context.  Just jump into btrfs_map_bio
998          */
999         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), bio, mirror_num, 1);
1000         if (ret) {
1001                 bio->bi_error = ret;
1002                 bio_endio(bio);
1003         }
1004         return ret;
1005 }
1006
1007 static int check_async_write(unsigned long bio_flags)
1008 {
1009         if (bio_flags & EXTENT_BIO_TREE_LOG)
1010                 return 0;
1011 #ifdef CONFIG_X86
1012         if (static_cpu_has(X86_FEATURE_XMM4_2))
1013                 return 0;
1014 #endif
1015         return 1;
1016 }
1017
1018 static int btree_submit_bio_hook(struct inode *inode, struct bio *bio,
1019                                  int mirror_num, unsigned long bio_flags,
1020                                  u64 bio_offset)
1021 {
1022         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1023         int async = check_async_write(bio_flags);
1024         int ret;
1025
1026         if (bio_op(bio) != REQ_OP_WRITE) {
1027                 /*
1028                  * called for a read, do the setup so that checksum validation
1029                  * can happen in the async kernel threads
1030                  */
1031                 ret = btrfs_bio_wq_end_io(fs_info, bio,
1032                                           BTRFS_WQ_ENDIO_METADATA);
1033                 if (ret)
1034                         goto out_w_error;
1035                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1036         } else if (!async) {
1037                 ret = btree_csum_one_bio(bio);
1038                 if (ret)
1039                         goto out_w_error;
1040                 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1041         } else {
1042                 /*
1043                  * kthread helpers are used to submit writes so that
1044                  * checksumming can happen in parallel across all CPUs
1045                  */
1046                 ret = btrfs_wq_submit_bio(fs_info, inode, bio, mirror_num, 0,
1047                                           bio_offset,
1048                                           __btree_submit_bio_start,
1049                                           __btree_submit_bio_done);
1050         }
1051
1052         if (ret)
1053                 goto out_w_error;
1054         return 0;
1055
1056 out_w_error:
1057         bio->bi_error = ret;
1058         bio_endio(bio);
1059         return ret;
1060 }
1061
1062 #ifdef CONFIG_MIGRATION
1063 static int btree_migratepage(struct address_space *mapping,
1064                         struct page *newpage, struct page *page,
1065                         enum migrate_mode mode)
1066 {
1067         /*
1068          * we can't safely write a btree page from here,
1069          * we haven't done the locking hook
1070          */
1071         if (PageDirty(page))
1072                 return -EAGAIN;
1073         /*
1074          * Buffers may be managed in a filesystem specific way.
1075          * We must have no buffers or drop them.
1076          */
1077         if (page_has_private(page) &&
1078             !try_to_release_page(page, GFP_KERNEL))
1079                 return -EAGAIN;
1080         return migrate_page(mapping, newpage, page, mode);
1081 }
1082 #endif
1083
1084
1085 static int btree_writepages(struct address_space *mapping,
1086                             struct writeback_control *wbc)
1087 {
1088         struct btrfs_fs_info *fs_info;
1089         int ret;
1090
1091         if (wbc->sync_mode == WB_SYNC_NONE) {
1092
1093                 if (wbc->for_kupdate)
1094                         return 0;
1095
1096                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1097                 /* this is a bit racy, but that's ok */
1098                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1099                                              BTRFS_DIRTY_METADATA_THRESH);
1100                 if (ret < 0)
1101                         return 0;
1102         }
1103         return btree_write_cache_pages(mapping, wbc);
1104 }
1105
1106 static int btree_readpage(struct file *file, struct page *page)
1107 {
1108         struct extent_io_tree *tree;
1109         tree = &BTRFS_I(page->mapping->host)->io_tree;
1110         return extent_read_full_page(tree, page, btree_get_extent, 0);
1111 }
1112
1113 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1114 {
1115         if (PageWriteback(page) || PageDirty(page))
1116                 return 0;
1117
1118         return try_release_extent_buffer(page);
1119 }
1120
1121 static void btree_invalidatepage(struct page *page, unsigned int offset,
1122                                  unsigned int length)
1123 {
1124         struct extent_io_tree *tree;
1125         tree = &BTRFS_I(page->mapping->host)->io_tree;
1126         extent_invalidatepage(tree, page, offset);
1127         btree_releasepage(page, GFP_NOFS);
1128         if (PagePrivate(page)) {
1129                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1130                            "page private not zero on page %llu",
1131                            (unsigned long long)page_offset(page));
1132                 ClearPagePrivate(page);
1133                 set_page_private(page, 0);
1134                 put_page(page);
1135         }
1136 }
1137
1138 static int btree_set_page_dirty(struct page *page)
1139 {
1140 #ifdef DEBUG
1141         struct extent_buffer *eb;
1142
1143         BUG_ON(!PagePrivate(page));
1144         eb = (struct extent_buffer *)page->private;
1145         BUG_ON(!eb);
1146         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1147         BUG_ON(!atomic_read(&eb->refs));
1148         btrfs_assert_tree_locked(eb);
1149 #endif
1150         return __set_page_dirty_nobuffers(page);
1151 }
1152
1153 static const struct address_space_operations btree_aops = {
1154         .readpage       = btree_readpage,
1155         .writepages     = btree_writepages,
1156         .releasepage    = btree_releasepage,
1157         .invalidatepage = btree_invalidatepage,
1158 #ifdef CONFIG_MIGRATION
1159         .migratepage    = btree_migratepage,
1160 #endif
1161         .set_page_dirty = btree_set_page_dirty,
1162 };
1163
1164 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr)
1165 {
1166         struct extent_buffer *buf = NULL;
1167         struct inode *btree_inode = fs_info->btree_inode;
1168
1169         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1170         if (IS_ERR(buf))
1171                 return;
1172         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1173                                  buf, WAIT_NONE, btree_get_extent, 0);
1174         free_extent_buffer(buf);
1175 }
1176
1177 int reada_tree_block_flagged(struct btrfs_fs_info *fs_info, u64 bytenr,
1178                          int mirror_num, struct extent_buffer **eb)
1179 {
1180         struct extent_buffer *buf = NULL;
1181         struct inode *btree_inode = fs_info->btree_inode;
1182         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1183         int ret;
1184
1185         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1186         if (IS_ERR(buf))
1187                 return 0;
1188
1189         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1190
1191         ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
1192                                        btree_get_extent, mirror_num);
1193         if (ret) {
1194                 free_extent_buffer(buf);
1195                 return ret;
1196         }
1197
1198         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1199                 free_extent_buffer(buf);
1200                 return -EIO;
1201         } else if (extent_buffer_uptodate(buf)) {
1202                 *eb = buf;
1203         } else {
1204                 free_extent_buffer(buf);
1205         }
1206         return 0;
1207 }
1208
1209 struct extent_buffer *btrfs_find_create_tree_block(
1210                                                 struct btrfs_fs_info *fs_info,
1211                                                 u64 bytenr)
1212 {
1213         if (btrfs_is_testing(fs_info))
1214                 return alloc_test_extent_buffer(fs_info, bytenr);
1215         return alloc_extent_buffer(fs_info, bytenr);
1216 }
1217
1218
1219 int btrfs_write_tree_block(struct extent_buffer *buf)
1220 {
1221         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1222                                         buf->start + buf->len - 1);
1223 }
1224
1225 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1226 {
1227         return filemap_fdatawait_range(buf->pages[0]->mapping,
1228                                        buf->start, buf->start + buf->len - 1);
1229 }
1230
1231 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1232                                       u64 parent_transid)
1233 {
1234         struct extent_buffer *buf = NULL;
1235         int ret;
1236
1237         buf = btrfs_find_create_tree_block(fs_info, bytenr);
1238         if (IS_ERR(buf))
1239                 return buf;
1240
1241         ret = btree_read_extent_buffer_pages(fs_info, buf, parent_transid);
1242         if (ret) {
1243                 free_extent_buffer(buf);
1244                 return ERR_PTR(ret);
1245         }
1246         return buf;
1247
1248 }
1249
1250 void clean_tree_block(struct btrfs_fs_info *fs_info,
1251                       struct extent_buffer *buf)
1252 {
1253         if (btrfs_header_generation(buf) ==
1254             fs_info->running_transaction->transid) {
1255                 btrfs_assert_tree_locked(buf);
1256
1257                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1258                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1259                                              -buf->len,
1260                                              fs_info->dirty_metadata_batch);
1261                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1262                         btrfs_set_lock_blocking(buf);
1263                         clear_extent_buffer_dirty(buf);
1264                 }
1265         }
1266 }
1267
1268 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1269 {
1270         struct btrfs_subvolume_writers *writers;
1271         int ret;
1272
1273         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1274         if (!writers)
1275                 return ERR_PTR(-ENOMEM);
1276
1277         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1278         if (ret < 0) {
1279                 kfree(writers);
1280                 return ERR_PTR(ret);
1281         }
1282
1283         init_waitqueue_head(&writers->wait);
1284         return writers;
1285 }
1286
1287 static void
1288 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1289 {
1290         percpu_counter_destroy(&writers->counter);
1291         kfree(writers);
1292 }
1293
1294 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1295                          u64 objectid)
1296 {
1297         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1298         root->node = NULL;
1299         root->commit_root = NULL;
1300         root->state = 0;
1301         root->orphan_cleanup_state = 0;
1302
1303         root->objectid = objectid;
1304         root->last_trans = 0;
1305         root->highest_objectid = 0;
1306         root->nr_delalloc_inodes = 0;
1307         root->nr_ordered_extents = 0;
1308         root->name = NULL;
1309         root->inode_tree = RB_ROOT;
1310         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1311         root->block_rsv = NULL;
1312         root->orphan_block_rsv = NULL;
1313
1314         INIT_LIST_HEAD(&root->dirty_list);
1315         INIT_LIST_HEAD(&root->root_list);
1316         INIT_LIST_HEAD(&root->delalloc_inodes);
1317         INIT_LIST_HEAD(&root->delalloc_root);
1318         INIT_LIST_HEAD(&root->ordered_extents);
1319         INIT_LIST_HEAD(&root->ordered_root);
1320         INIT_LIST_HEAD(&root->logged_list[0]);
1321         INIT_LIST_HEAD(&root->logged_list[1]);
1322         spin_lock_init(&root->orphan_lock);
1323         spin_lock_init(&root->inode_lock);
1324         spin_lock_init(&root->delalloc_lock);
1325         spin_lock_init(&root->ordered_extent_lock);
1326         spin_lock_init(&root->accounting_lock);
1327         spin_lock_init(&root->log_extents_lock[0]);
1328         spin_lock_init(&root->log_extents_lock[1]);
1329         mutex_init(&root->objectid_mutex);
1330         mutex_init(&root->log_mutex);
1331         mutex_init(&root->ordered_extent_mutex);
1332         mutex_init(&root->delalloc_mutex);
1333         init_waitqueue_head(&root->log_writer_wait);
1334         init_waitqueue_head(&root->log_commit_wait[0]);
1335         init_waitqueue_head(&root->log_commit_wait[1]);
1336         INIT_LIST_HEAD(&root->log_ctxs[0]);
1337         INIT_LIST_HEAD(&root->log_ctxs[1]);
1338         atomic_set(&root->log_commit[0], 0);
1339         atomic_set(&root->log_commit[1], 0);
1340         atomic_set(&root->log_writers, 0);
1341         atomic_set(&root->log_batch, 0);
1342         atomic_set(&root->orphan_inodes, 0);
1343         atomic_set(&root->refs, 1);
1344         atomic_set(&root->will_be_snapshoted, 0);
1345         atomic64_set(&root->qgroup_meta_rsv, 0);
1346         root->log_transid = 0;
1347         root->log_transid_committed = -1;
1348         root->last_log_commit = 0;
1349         if (!dummy)
1350                 extent_io_tree_init(&root->dirty_log_pages,
1351                                      fs_info->btree_inode->i_mapping);
1352
1353         memset(&root->root_key, 0, sizeof(root->root_key));
1354         memset(&root->root_item, 0, sizeof(root->root_item));
1355         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1356         if (!dummy)
1357                 root->defrag_trans_start = fs_info->generation;
1358         else
1359                 root->defrag_trans_start = 0;
1360         root->root_key.objectid = objectid;
1361         root->anon_dev = 0;
1362
1363         spin_lock_init(&root->root_item_lock);
1364 }
1365
1366 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1367                 gfp_t flags)
1368 {
1369         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1370         if (root)
1371                 root->fs_info = fs_info;
1372         return root;
1373 }
1374
1375 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1376 /* Should only be used by the testing infrastructure */
1377 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1378 {
1379         struct btrfs_root *root;
1380
1381         if (!fs_info)
1382                 return ERR_PTR(-EINVAL);
1383
1384         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1385         if (!root)
1386                 return ERR_PTR(-ENOMEM);
1387
1388         /* We don't use the stripesize in selftest, set it as sectorsize */
1389         __setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1390         root->alloc_bytenr = 0;
1391
1392         return root;
1393 }
1394 #endif
1395
1396 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1397                                      struct btrfs_fs_info *fs_info,
1398                                      u64 objectid)
1399 {
1400         struct extent_buffer *leaf;
1401         struct btrfs_root *tree_root = fs_info->tree_root;
1402         struct btrfs_root *root;
1403         struct btrfs_key key;
1404         int ret = 0;
1405         uuid_le uuid;
1406
1407         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1408         if (!root)
1409                 return ERR_PTR(-ENOMEM);
1410
1411         __setup_root(root, fs_info, objectid);
1412         root->root_key.objectid = objectid;
1413         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1414         root->root_key.offset = 0;
1415
1416         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1417         if (IS_ERR(leaf)) {
1418                 ret = PTR_ERR(leaf);
1419                 leaf = NULL;
1420                 goto fail;
1421         }
1422
1423         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1424         btrfs_set_header_bytenr(leaf, leaf->start);
1425         btrfs_set_header_generation(leaf, trans->transid);
1426         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1427         btrfs_set_header_owner(leaf, objectid);
1428         root->node = leaf;
1429
1430         write_extent_buffer_fsid(leaf, fs_info->fsid);
1431         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
1432         btrfs_mark_buffer_dirty(leaf);
1433
1434         root->commit_root = btrfs_root_node(root);
1435         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1436
1437         root->root_item.flags = 0;
1438         root->root_item.byte_limit = 0;
1439         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1440         btrfs_set_root_generation(&root->root_item, trans->transid);
1441         btrfs_set_root_level(&root->root_item, 0);
1442         btrfs_set_root_refs(&root->root_item, 1);
1443         btrfs_set_root_used(&root->root_item, leaf->len);
1444         btrfs_set_root_last_snapshot(&root->root_item, 0);
1445         btrfs_set_root_dirid(&root->root_item, 0);
1446         uuid_le_gen(&uuid);
1447         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1448         root->root_item.drop_level = 0;
1449
1450         key.objectid = objectid;
1451         key.type = BTRFS_ROOT_ITEM_KEY;
1452         key.offset = 0;
1453         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1454         if (ret)
1455                 goto fail;
1456
1457         btrfs_tree_unlock(leaf);
1458
1459         return root;
1460
1461 fail:
1462         if (leaf) {
1463                 btrfs_tree_unlock(leaf);
1464                 free_extent_buffer(root->commit_root);
1465                 free_extent_buffer(leaf);
1466         }
1467         kfree(root);
1468
1469         return ERR_PTR(ret);
1470 }
1471
1472 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1473                                          struct btrfs_fs_info *fs_info)
1474 {
1475         struct btrfs_root *root;
1476         struct extent_buffer *leaf;
1477
1478         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1479         if (!root)
1480                 return ERR_PTR(-ENOMEM);
1481
1482         __setup_root(root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1483
1484         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1485         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1486         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1487
1488         /*
1489          * DON'T set REF_COWS for log trees
1490          *
1491          * log trees do not get reference counted because they go away
1492          * before a real commit is actually done.  They do store pointers
1493          * to file data extents, and those reference counts still get
1494          * updated (along with back refs to the log tree).
1495          */
1496
1497         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1498                         NULL, 0, 0, 0);
1499         if (IS_ERR(leaf)) {
1500                 kfree(root);
1501                 return ERR_CAST(leaf);
1502         }
1503
1504         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
1505         btrfs_set_header_bytenr(leaf, leaf->start);
1506         btrfs_set_header_generation(leaf, trans->transid);
1507         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1508         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1509         root->node = leaf;
1510
1511         write_extent_buffer_fsid(root->node, fs_info->fsid);
1512         btrfs_mark_buffer_dirty(root->node);
1513         btrfs_tree_unlock(root->node);
1514         return root;
1515 }
1516
1517 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1518                              struct btrfs_fs_info *fs_info)
1519 {
1520         struct btrfs_root *log_root;
1521
1522         log_root = alloc_log_tree(trans, fs_info);
1523         if (IS_ERR(log_root))
1524                 return PTR_ERR(log_root);
1525         WARN_ON(fs_info->log_root_tree);
1526         fs_info->log_root_tree = log_root;
1527         return 0;
1528 }
1529
1530 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1531                        struct btrfs_root *root)
1532 {
1533         struct btrfs_fs_info *fs_info = root->fs_info;
1534         struct btrfs_root *log_root;
1535         struct btrfs_inode_item *inode_item;
1536
1537         log_root = alloc_log_tree(trans, fs_info);
1538         if (IS_ERR(log_root))
1539                 return PTR_ERR(log_root);
1540
1541         log_root->last_trans = trans->transid;
1542         log_root->root_key.offset = root->root_key.objectid;
1543
1544         inode_item = &log_root->root_item.inode;
1545         btrfs_set_stack_inode_generation(inode_item, 1);
1546         btrfs_set_stack_inode_size(inode_item, 3);
1547         btrfs_set_stack_inode_nlink(inode_item, 1);
1548         btrfs_set_stack_inode_nbytes(inode_item,
1549                                      fs_info->nodesize);
1550         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1551
1552         btrfs_set_root_node(&log_root->root_item, log_root->node);
1553
1554         WARN_ON(root->log_root);
1555         root->log_root = log_root;
1556         root->log_transid = 0;
1557         root->log_transid_committed = -1;
1558         root->last_log_commit = 0;
1559         return 0;
1560 }
1561
1562 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1563                                                struct btrfs_key *key)
1564 {
1565         struct btrfs_root *root;
1566         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1567         struct btrfs_path *path;
1568         u64 generation;
1569         int ret;
1570
1571         path = btrfs_alloc_path();
1572         if (!path)
1573                 return ERR_PTR(-ENOMEM);
1574
1575         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1576         if (!root) {
1577                 ret = -ENOMEM;
1578                 goto alloc_fail;
1579         }
1580
1581         __setup_root(root, fs_info, key->objectid);
1582
1583         ret = btrfs_find_root(tree_root, key, path,
1584                               &root->root_item, &root->root_key);
1585         if (ret) {
1586                 if (ret > 0)
1587                         ret = -ENOENT;
1588                 goto find_fail;
1589         }
1590
1591         generation = btrfs_root_generation(&root->root_item);
1592         root->node = read_tree_block(fs_info,
1593                                      btrfs_root_bytenr(&root->root_item),
1594                                      generation);
1595         if (IS_ERR(root->node)) {
1596                 ret = PTR_ERR(root->node);
1597                 goto find_fail;
1598         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1599                 ret = -EIO;
1600                 free_extent_buffer(root->node);
1601                 goto find_fail;
1602         }
1603         root->commit_root = btrfs_root_node(root);
1604 out:
1605         btrfs_free_path(path);
1606         return root;
1607
1608 find_fail:
1609         kfree(root);
1610 alloc_fail:
1611         root = ERR_PTR(ret);
1612         goto out;
1613 }
1614
1615 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1616                                       struct btrfs_key *location)
1617 {
1618         struct btrfs_root *root;
1619
1620         root = btrfs_read_tree_root(tree_root, location);
1621         if (IS_ERR(root))
1622                 return root;
1623
1624         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1625                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1626                 btrfs_check_and_init_root_item(&root->root_item);
1627         }
1628
1629         return root;
1630 }
1631
1632 int btrfs_init_fs_root(struct btrfs_root *root)
1633 {
1634         int ret;
1635         struct btrfs_subvolume_writers *writers;
1636
1637         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1638         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1639                                         GFP_NOFS);
1640         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1641                 ret = -ENOMEM;
1642                 goto fail;
1643         }
1644
1645         writers = btrfs_alloc_subvolume_writers();
1646         if (IS_ERR(writers)) {
1647                 ret = PTR_ERR(writers);
1648                 goto fail;
1649         }
1650         root->subv_writers = writers;
1651
1652         btrfs_init_free_ino_ctl(root);
1653         spin_lock_init(&root->ino_cache_lock);
1654         init_waitqueue_head(&root->ino_cache_wait);
1655
1656         ret = get_anon_bdev(&root->anon_dev);
1657         if (ret)
1658                 goto fail;
1659
1660         mutex_lock(&root->objectid_mutex);
1661         ret = btrfs_find_highest_objectid(root,
1662                                         &root->highest_objectid);
1663         if (ret) {
1664                 mutex_unlock(&root->objectid_mutex);
1665                 goto fail;
1666         }
1667
1668         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1669
1670         mutex_unlock(&root->objectid_mutex);
1671
1672         return 0;
1673 fail:
1674         /* the caller is responsible to call free_fs_root */
1675         return ret;
1676 }
1677
1678 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1679                                         u64 root_id)
1680 {
1681         struct btrfs_root *root;
1682
1683         spin_lock(&fs_info->fs_roots_radix_lock);
1684         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1685                                  (unsigned long)root_id);
1686         spin_unlock(&fs_info->fs_roots_radix_lock);
1687         return root;
1688 }
1689
1690 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1691                          struct btrfs_root *root)
1692 {
1693         int ret;
1694
1695         ret = radix_tree_preload(GFP_NOFS);
1696         if (ret)
1697                 return ret;
1698
1699         spin_lock(&fs_info->fs_roots_radix_lock);
1700         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1701                                 (unsigned long)root->root_key.objectid,
1702                                 root);
1703         if (ret == 0)
1704                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1705         spin_unlock(&fs_info->fs_roots_radix_lock);
1706         radix_tree_preload_end();
1707
1708         return ret;
1709 }
1710
1711 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1712                                      struct btrfs_key *location,
1713                                      bool check_ref)
1714 {
1715         struct btrfs_root *root;
1716         struct btrfs_path *path;
1717         struct btrfs_key key;
1718         int ret;
1719
1720         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1721                 return fs_info->tree_root;
1722         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1723                 return fs_info->extent_root;
1724         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1725                 return fs_info->chunk_root;
1726         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1727                 return fs_info->dev_root;
1728         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1729                 return fs_info->csum_root;
1730         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1731                 return fs_info->quota_root ? fs_info->quota_root :
1732                                              ERR_PTR(-ENOENT);
1733         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1734                 return fs_info->uuid_root ? fs_info->uuid_root :
1735                                             ERR_PTR(-ENOENT);
1736         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1737                 return fs_info->free_space_root ? fs_info->free_space_root :
1738                                                   ERR_PTR(-ENOENT);
1739 again:
1740         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1741         if (root) {
1742                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1743                         return ERR_PTR(-ENOENT);
1744                 return root;
1745         }
1746
1747         root = btrfs_read_fs_root(fs_info->tree_root, location);
1748         if (IS_ERR(root))
1749                 return root;
1750
1751         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1752                 ret = -ENOENT;
1753                 goto fail;
1754         }
1755
1756         ret = btrfs_init_fs_root(root);
1757         if (ret)
1758                 goto fail;
1759
1760         path = btrfs_alloc_path();
1761         if (!path) {
1762                 ret = -ENOMEM;
1763                 goto fail;
1764         }
1765         key.objectid = BTRFS_ORPHAN_OBJECTID;
1766         key.type = BTRFS_ORPHAN_ITEM_KEY;
1767         key.offset = location->objectid;
1768
1769         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1770         btrfs_free_path(path);
1771         if (ret < 0)
1772                 goto fail;
1773         if (ret == 0)
1774                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1775
1776         ret = btrfs_insert_fs_root(fs_info, root);
1777         if (ret) {
1778                 if (ret == -EEXIST) {
1779                         free_fs_root(root);
1780                         goto again;
1781                 }
1782                 goto fail;
1783         }
1784         return root;
1785 fail:
1786         free_fs_root(root);
1787         return ERR_PTR(ret);
1788 }
1789
1790 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1791 {
1792         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1793         int ret = 0;
1794         struct btrfs_device *device;
1795         struct backing_dev_info *bdi;
1796
1797         rcu_read_lock();
1798         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1799                 if (!device->bdev)
1800                         continue;
1801                 bdi = device->bdev->bd_bdi;
1802                 if (bdi_congested(bdi, bdi_bits)) {
1803                         ret = 1;
1804                         break;
1805                 }
1806         }
1807         rcu_read_unlock();
1808         return ret;
1809 }
1810
1811 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1812 {
1813         int err;
1814
1815         err = bdi_setup_and_register(bdi, "btrfs");
1816         if (err)
1817                 return err;
1818
1819         bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
1820         bdi->congested_fn       = btrfs_congested_fn;
1821         bdi->congested_data     = info;
1822         bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
1823         return 0;
1824 }
1825
1826 /*
1827  * called by the kthread helper functions to finally call the bio end_io
1828  * functions.  This is where read checksum verification actually happens
1829  */
1830 static void end_workqueue_fn(struct btrfs_work *work)
1831 {
1832         struct bio *bio;
1833         struct btrfs_end_io_wq *end_io_wq;
1834
1835         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1836         bio = end_io_wq->bio;
1837
1838         bio->bi_error = end_io_wq->error;
1839         bio->bi_private = end_io_wq->private;
1840         bio->bi_end_io = end_io_wq->end_io;
1841         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1842         bio_endio(bio);
1843 }
1844
1845 static int cleaner_kthread(void *arg)
1846 {
1847         struct btrfs_root *root = arg;
1848         struct btrfs_fs_info *fs_info = root->fs_info;
1849         int again;
1850         struct btrfs_trans_handle *trans;
1851
1852         do {
1853                 again = 0;
1854
1855                 /* Make the cleaner go to sleep early. */
1856                 if (btrfs_need_cleaner_sleep(fs_info))
1857                         goto sleep;
1858
1859                 /*
1860                  * Do not do anything if we might cause open_ctree() to block
1861                  * before we have finished mounting the filesystem.
1862                  */
1863                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1864                         goto sleep;
1865
1866                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1867                         goto sleep;
1868
1869                 /*
1870                  * Avoid the problem that we change the status of the fs
1871                  * during the above check and trylock.
1872                  */
1873                 if (btrfs_need_cleaner_sleep(fs_info)) {
1874                         mutex_unlock(&fs_info->cleaner_mutex);
1875                         goto sleep;
1876                 }
1877
1878                 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
1879                 btrfs_run_delayed_iputs(fs_info);
1880                 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
1881
1882                 again = btrfs_clean_one_deleted_snapshot(root);
1883                 mutex_unlock(&fs_info->cleaner_mutex);
1884
1885                 /*
1886                  * The defragger has dealt with the R/O remount and umount,
1887                  * needn't do anything special here.
1888                  */
1889                 btrfs_run_defrag_inodes(fs_info);
1890
1891                 /*
1892                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1893                  * with relocation (btrfs_relocate_chunk) and relocation
1894                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1895                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1896                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1897                  * unused block groups.
1898                  */
1899                 btrfs_delete_unused_bgs(fs_info);
1900 sleep:
1901                 if (!again) {
1902                         set_current_state(TASK_INTERRUPTIBLE);
1903                         if (!kthread_should_stop())
1904                                 schedule();
1905                         __set_current_state(TASK_RUNNING);
1906                 }
1907         } while (!kthread_should_stop());
1908
1909         /*
1910          * Transaction kthread is stopped before us and wakes us up.
1911          * However we might have started a new transaction and COWed some
1912          * tree blocks when deleting unused block groups for example. So
1913          * make sure we commit the transaction we started to have a clean
1914          * shutdown when evicting the btree inode - if it has dirty pages
1915          * when we do the final iput() on it, eviction will trigger a
1916          * writeback for it which will fail with null pointer dereferences
1917          * since work queues and other resources were already released and
1918          * destroyed by the time the iput/eviction/writeback is made.
1919          */
1920         trans = btrfs_attach_transaction(root);
1921         if (IS_ERR(trans)) {
1922                 if (PTR_ERR(trans) != -ENOENT)
1923                         btrfs_err(fs_info,
1924                                   "cleaner transaction attach returned %ld",
1925                                   PTR_ERR(trans));
1926         } else {
1927                 int ret;
1928
1929                 ret = btrfs_commit_transaction(trans);
1930                 if (ret)
1931                         btrfs_err(fs_info,
1932                                   "cleaner open transaction commit returned %d",
1933                                   ret);
1934         }
1935
1936         return 0;
1937 }
1938
1939 static int transaction_kthread(void *arg)
1940 {
1941         struct btrfs_root *root = arg;
1942         struct btrfs_fs_info *fs_info = root->fs_info;
1943         struct btrfs_trans_handle *trans;
1944         struct btrfs_transaction *cur;
1945         u64 transid;
1946         unsigned long now;
1947         unsigned long delay;
1948         bool cannot_commit;
1949
1950         do {
1951                 cannot_commit = false;
1952                 delay = HZ * fs_info->commit_interval;
1953                 mutex_lock(&fs_info->transaction_kthread_mutex);
1954
1955                 spin_lock(&fs_info->trans_lock);
1956                 cur = fs_info->running_transaction;
1957                 if (!cur) {
1958                         spin_unlock(&fs_info->trans_lock);
1959                         goto sleep;
1960                 }
1961
1962                 now = get_seconds();
1963                 if (cur->state < TRANS_STATE_BLOCKED &&
1964                     (now < cur->start_time ||
1965                      now - cur->start_time < fs_info->commit_interval)) {
1966                         spin_unlock(&fs_info->trans_lock);
1967                         delay = HZ * 5;
1968                         goto sleep;
1969                 }
1970                 transid = cur->transid;
1971                 spin_unlock(&fs_info->trans_lock);
1972
1973                 /* If the file system is aborted, this will always fail. */
1974                 trans = btrfs_attach_transaction(root);
1975                 if (IS_ERR(trans)) {
1976                         if (PTR_ERR(trans) != -ENOENT)
1977                                 cannot_commit = true;
1978                         goto sleep;
1979                 }
1980                 if (transid == trans->transid) {
1981                         btrfs_commit_transaction(trans);
1982                 } else {
1983                         btrfs_end_transaction(trans);
1984                 }
1985 sleep:
1986                 wake_up_process(fs_info->cleaner_kthread);
1987                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1988
1989                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1990                                       &fs_info->fs_state)))
1991                         btrfs_cleanup_transaction(fs_info);
1992                 set_current_state(TASK_INTERRUPTIBLE);
1993                 if (!kthread_should_stop() &&
1994                                 (!btrfs_transaction_blocked(fs_info) ||
1995                                  cannot_commit))
1996                         schedule_timeout(delay);
1997                 __set_current_state(TASK_RUNNING);
1998         } while (!kthread_should_stop());
1999         return 0;
2000 }
2001
2002 /*
2003  * this will find the highest generation in the array of
2004  * root backups.  The index of the highest array is returned,
2005  * or -1 if we can't find anything.
2006  *
2007  * We check to make sure the array is valid by comparing the
2008  * generation of the latest  root in the array with the generation
2009  * in the super block.  If they don't match we pitch it.
2010  */
2011 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
2012 {
2013         u64 cur;
2014         int newest_index = -1;
2015         struct btrfs_root_backup *root_backup;
2016         int i;
2017
2018         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2019                 root_backup = info->super_copy->super_roots + i;
2020                 cur = btrfs_backup_tree_root_gen(root_backup);
2021                 if (cur == newest_gen)
2022                         newest_index = i;
2023         }
2024
2025         /* check to see if we actually wrapped around */
2026         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
2027                 root_backup = info->super_copy->super_roots;
2028                 cur = btrfs_backup_tree_root_gen(root_backup);
2029                 if (cur == newest_gen)
2030                         newest_index = 0;
2031         }
2032         return newest_index;
2033 }
2034
2035
2036 /*
2037  * find the oldest backup so we know where to store new entries
2038  * in the backup array.  This will set the backup_root_index
2039  * field in the fs_info struct
2040  */
2041 static void find_oldest_super_backup(struct btrfs_fs_info *info,
2042                                      u64 newest_gen)
2043 {
2044         int newest_index = -1;
2045
2046         newest_index = find_newest_super_backup(info, newest_gen);
2047         /* if there was garbage in there, just move along */
2048         if (newest_index == -1) {
2049                 info->backup_root_index = 0;
2050         } else {
2051                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
2052         }
2053 }
2054
2055 /*
2056  * copy all the root pointers into the super backup array.
2057  * this will bump the backup pointer by one when it is
2058  * done
2059  */
2060 static void backup_super_roots(struct btrfs_fs_info *info)
2061 {
2062         int next_backup;
2063         struct btrfs_root_backup *root_backup;
2064         int last_backup;
2065
2066         next_backup = info->backup_root_index;
2067         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
2068                 BTRFS_NUM_BACKUP_ROOTS;
2069
2070         /*
2071          * just overwrite the last backup if we're at the same generation
2072          * this happens only at umount
2073          */
2074         root_backup = info->super_for_commit->super_roots + last_backup;
2075         if (btrfs_backup_tree_root_gen(root_backup) ==
2076             btrfs_header_generation(info->tree_root->node))
2077                 next_backup = last_backup;
2078
2079         root_backup = info->super_for_commit->super_roots + next_backup;
2080
2081         /*
2082          * make sure all of our padding and empty slots get zero filled
2083          * regardless of which ones we use today
2084          */
2085         memset(root_backup, 0, sizeof(*root_backup));
2086
2087         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2088
2089         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2090         btrfs_set_backup_tree_root_gen(root_backup,
2091                                btrfs_header_generation(info->tree_root->node));
2092
2093         btrfs_set_backup_tree_root_level(root_backup,
2094                                btrfs_header_level(info->tree_root->node));
2095
2096         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2097         btrfs_set_backup_chunk_root_gen(root_backup,
2098                                btrfs_header_generation(info->chunk_root->node));
2099         btrfs_set_backup_chunk_root_level(root_backup,
2100                                btrfs_header_level(info->chunk_root->node));
2101
2102         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2103         btrfs_set_backup_extent_root_gen(root_backup,
2104                                btrfs_header_generation(info->extent_root->node));
2105         btrfs_set_backup_extent_root_level(root_backup,
2106                                btrfs_header_level(info->extent_root->node));
2107
2108         /*
2109          * we might commit during log recovery, which happens before we set
2110          * the fs_root.  Make sure it is valid before we fill it in.
2111          */
2112         if (info->fs_root && info->fs_root->node) {
2113                 btrfs_set_backup_fs_root(root_backup,
2114                                          info->fs_root->node->start);
2115                 btrfs_set_backup_fs_root_gen(root_backup,
2116                                btrfs_header_generation(info->fs_root->node));
2117                 btrfs_set_backup_fs_root_level(root_backup,
2118                                btrfs_header_level(info->fs_root->node));
2119         }
2120
2121         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2122         btrfs_set_backup_dev_root_gen(root_backup,
2123                                btrfs_header_generation(info->dev_root->node));
2124         btrfs_set_backup_dev_root_level(root_backup,
2125                                        btrfs_header_level(info->dev_root->node));
2126
2127         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2128         btrfs_set_backup_csum_root_gen(root_backup,
2129                                btrfs_header_generation(info->csum_root->node));
2130         btrfs_set_backup_csum_root_level(root_backup,
2131                                btrfs_header_level(info->csum_root->node));
2132
2133         btrfs_set_backup_total_bytes(root_backup,
2134                              btrfs_super_total_bytes(info->super_copy));
2135         btrfs_set_backup_bytes_used(root_backup,
2136                              btrfs_super_bytes_used(info->super_copy));
2137         btrfs_set_backup_num_devices(root_backup,
2138                              btrfs_super_num_devices(info->super_copy));
2139
2140         /*
2141          * if we don't copy this out to the super_copy, it won't get remembered
2142          * for the next commit
2143          */
2144         memcpy(&info->super_copy->super_roots,
2145                &info->super_for_commit->super_roots,
2146                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2147 }
2148
2149 /*
2150  * this copies info out of the root backup array and back into
2151  * the in-memory super block.  It is meant to help iterate through
2152  * the array, so you send it the number of backups you've already
2153  * tried and the last backup index you used.
2154  *
2155  * this returns -1 when it has tried all the backups
2156  */
2157 static noinline int next_root_backup(struct btrfs_fs_info *info,
2158                                      struct btrfs_super_block *super,
2159                                      int *num_backups_tried, int *backup_index)
2160 {
2161         struct btrfs_root_backup *root_backup;
2162         int newest = *backup_index;
2163
2164         if (*num_backups_tried == 0) {
2165                 u64 gen = btrfs_super_generation(super);
2166
2167                 newest = find_newest_super_backup(info, gen);
2168                 if (newest == -1)
2169                         return -1;
2170
2171                 *backup_index = newest;
2172                 *num_backups_tried = 1;
2173         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2174                 /* we've tried all the backups, all done */
2175                 return -1;
2176         } else {
2177                 /* jump to the next oldest backup */
2178                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2179                         BTRFS_NUM_BACKUP_ROOTS;
2180                 *backup_index = newest;
2181                 *num_backups_tried += 1;
2182         }
2183         root_backup = super->super_roots + newest;
2184
2185         btrfs_set_super_generation(super,
2186                                    btrfs_backup_tree_root_gen(root_backup));
2187         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2188         btrfs_set_super_root_level(super,
2189                                    btrfs_backup_tree_root_level(root_backup));
2190         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2191
2192         /*
2193          * fixme: the total bytes and num_devices need to match or we should
2194          * need a fsck
2195          */
2196         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2197         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2198         return 0;
2199 }
2200
2201 /* helper to cleanup workers */
2202 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2203 {
2204         btrfs_destroy_workqueue(fs_info->fixup_workers);
2205         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2206         btrfs_destroy_workqueue(fs_info->workers);
2207         btrfs_destroy_workqueue(fs_info->endio_workers);
2208         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2209         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2210         btrfs_destroy_workqueue(fs_info->rmw_workers);
2211         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2212         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2213         btrfs_destroy_workqueue(fs_info->submit_workers);
2214         btrfs_destroy_workqueue(fs_info->delayed_workers);
2215         btrfs_destroy_workqueue(fs_info->caching_workers);
2216         btrfs_destroy_workqueue(fs_info->readahead_workers);
2217         btrfs_destroy_workqueue(fs_info->flush_workers);
2218         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2219         btrfs_destroy_workqueue(fs_info->extent_workers);
2220         /*
2221          * Now that all other work queues are destroyed, we can safely destroy
2222          * the queues used for metadata I/O, since tasks from those other work
2223          * queues can do metadata I/O operations.
2224          */
2225         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2226         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2227 }
2228
2229 static void free_root_extent_buffers(struct btrfs_root *root)
2230 {
2231         if (root) {
2232                 free_extent_buffer(root->node);
2233                 free_extent_buffer(root->commit_root);
2234                 root->node = NULL;
2235                 root->commit_root = NULL;
2236         }
2237 }
2238
2239 /* helper to cleanup tree roots */
2240 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2241 {
2242         free_root_extent_buffers(info->tree_root);
2243
2244         free_root_extent_buffers(info->dev_root);
2245         free_root_extent_buffers(info->extent_root);
2246         free_root_extent_buffers(info->csum_root);
2247         free_root_extent_buffers(info->quota_root);
2248         free_root_extent_buffers(info->uuid_root);
2249         if (chunk_root)
2250                 free_root_extent_buffers(info->chunk_root);
2251         free_root_extent_buffers(info->free_space_root);
2252 }
2253
2254 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2255 {
2256         int ret;
2257         struct btrfs_root *gang[8];
2258         int i;
2259
2260         while (!list_empty(&fs_info->dead_roots)) {
2261                 gang[0] = list_entry(fs_info->dead_roots.next,
2262                                      struct btrfs_root, root_list);
2263                 list_del(&gang[0]->root_list);
2264
2265                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2266                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2267                 } else {
2268                         free_extent_buffer(gang[0]->node);
2269                         free_extent_buffer(gang[0]->commit_root);
2270                         btrfs_put_fs_root(gang[0]);
2271                 }
2272         }
2273
2274         while (1) {
2275                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2276                                              (void **)gang, 0,
2277                                              ARRAY_SIZE(gang));
2278                 if (!ret)
2279                         break;
2280                 for (i = 0; i < ret; i++)
2281                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2282         }
2283
2284         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2285                 btrfs_free_log_root_tree(NULL, fs_info);
2286                 btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
2287         }
2288 }
2289
2290 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2291 {
2292         mutex_init(&fs_info->scrub_lock);
2293         atomic_set(&fs_info->scrubs_running, 0);
2294         atomic_set(&fs_info->scrub_pause_req, 0);
2295         atomic_set(&fs_info->scrubs_paused, 0);
2296         atomic_set(&fs_info->scrub_cancel_req, 0);
2297         init_waitqueue_head(&fs_info->scrub_pause_wait);
2298         fs_info->scrub_workers_refcnt = 0;
2299 }
2300
2301 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2302 {
2303         spin_lock_init(&fs_info->balance_lock);
2304         mutex_init(&fs_info->balance_mutex);
2305         atomic_set(&fs_info->balance_running, 0);
2306         atomic_set(&fs_info->balance_pause_req, 0);
2307         atomic_set(&fs_info->balance_cancel_req, 0);
2308         fs_info->balance_ctl = NULL;
2309         init_waitqueue_head(&fs_info->balance_wait_q);
2310 }
2311
2312 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2313 {
2314         struct inode *inode = fs_info->btree_inode;
2315
2316         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2317         set_nlink(inode, 1);
2318         /*
2319          * we set the i_size on the btree inode to the max possible int.
2320          * the real end of the address space is determined by all of
2321          * the devices in the system
2322          */
2323         inode->i_size = OFFSET_MAX;
2324         inode->i_mapping->a_ops = &btree_aops;
2325
2326         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2327         extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode->i_mapping);
2328         BTRFS_I(inode)->io_tree.track_uptodate = 0;
2329         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2330
2331         BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
2332
2333         BTRFS_I(inode)->root = fs_info->tree_root;
2334         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2335         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2336         btrfs_insert_inode_hash(inode);
2337 }
2338
2339 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2340 {
2341         fs_info->dev_replace.lock_owner = 0;
2342         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2343         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2344         rwlock_init(&fs_info->dev_replace.lock);
2345         atomic_set(&fs_info->dev_replace.read_locks, 0);
2346         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2347         init_waitqueue_head(&fs_info->replace_wait);
2348         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2349 }
2350
2351 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2352 {
2353         spin_lock_init(&fs_info->qgroup_lock);
2354         mutex_init(&fs_info->qgroup_ioctl_lock);
2355         fs_info->qgroup_tree = RB_ROOT;
2356         fs_info->qgroup_op_tree = RB_ROOT;
2357         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2358         fs_info->qgroup_seq = 1;
2359         fs_info->qgroup_ulist = NULL;
2360         fs_info->qgroup_rescan_running = false;
2361         mutex_init(&fs_info->qgroup_rescan_lock);
2362 }
2363
2364 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2365                 struct btrfs_fs_devices *fs_devices)
2366 {
2367         int max_active = fs_info->thread_pool_size;
2368         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2369
2370         fs_info->workers =
2371                 btrfs_alloc_workqueue(fs_info, "worker",
2372                                       flags | WQ_HIGHPRI, max_active, 16);
2373
2374         fs_info->delalloc_workers =
2375                 btrfs_alloc_workqueue(fs_info, "delalloc",
2376                                       flags, max_active, 2);
2377
2378         fs_info->flush_workers =
2379                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2380                                       flags, max_active, 0);
2381
2382         fs_info->caching_workers =
2383                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2384
2385         /*
2386          * a higher idle thresh on the submit workers makes it much more
2387          * likely that bios will be send down in a sane order to the
2388          * devices
2389          */
2390         fs_info->submit_workers =
2391                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2392                                       min_t(u64, fs_devices->num_devices,
2393                                             max_active), 64);
2394
2395         fs_info->fixup_workers =
2396                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2397
2398         /*
2399          * endios are largely parallel and should have a very
2400          * low idle thresh
2401          */
2402         fs_info->endio_workers =
2403                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2404         fs_info->endio_meta_workers =
2405                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2406                                       max_active, 4);
2407         fs_info->endio_meta_write_workers =
2408                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2409                                       max_active, 2);
2410         fs_info->endio_raid56_workers =
2411                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2412                                       max_active, 4);
2413         fs_info->endio_repair_workers =
2414                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2415         fs_info->rmw_workers =
2416                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2417         fs_info->endio_write_workers =
2418                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2419                                       max_active, 2);
2420         fs_info->endio_freespace_worker =
2421                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2422                                       max_active, 0);
2423         fs_info->delayed_workers =
2424                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2425                                       max_active, 0);
2426         fs_info->readahead_workers =
2427                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2428                                       max_active, 2);
2429         fs_info->qgroup_rescan_workers =
2430                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2431         fs_info->extent_workers =
2432                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2433                                       min_t(u64, fs_devices->num_devices,
2434                                             max_active), 8);
2435
2436         if (!(fs_info->workers && fs_info->delalloc_workers &&
2437               fs_info->submit_workers && fs_info->flush_workers &&
2438               fs_info->endio_workers && fs_info->endio_meta_workers &&
2439               fs_info->endio_meta_write_workers &&
2440               fs_info->endio_repair_workers &&
2441               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2442               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2443               fs_info->caching_workers && fs_info->readahead_workers &&
2444               fs_info->fixup_workers && fs_info->delayed_workers &&
2445               fs_info->extent_workers &&
2446               fs_info->qgroup_rescan_workers)) {
2447                 return -ENOMEM;
2448         }
2449
2450         return 0;
2451 }
2452
2453 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2454                             struct btrfs_fs_devices *fs_devices)
2455 {
2456         int ret;
2457         struct btrfs_root *log_tree_root;
2458         struct btrfs_super_block *disk_super = fs_info->super_copy;
2459         u64 bytenr = btrfs_super_log_root(disk_super);
2460
2461         if (fs_devices->rw_devices == 0) {
2462                 btrfs_warn(fs_info, "log replay required on RO media");
2463                 return -EIO;
2464         }
2465
2466         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2467         if (!log_tree_root)
2468                 return -ENOMEM;
2469
2470         __setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2471
2472         log_tree_root->node = read_tree_block(fs_info, bytenr,
2473                                               fs_info->generation + 1);
2474         if (IS_ERR(log_tree_root->node)) {
2475                 btrfs_warn(fs_info, "failed to read log tree");
2476                 ret = PTR_ERR(log_tree_root->node);
2477                 kfree(log_tree_root);
2478                 return ret;
2479         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2480                 btrfs_err(fs_info, "failed to read log tree");
2481                 free_extent_buffer(log_tree_root->node);
2482                 kfree(log_tree_root);
2483                 return -EIO;
2484         }
2485         /* returns with log_tree_root freed on success */
2486         ret = btrfs_recover_log_trees(log_tree_root);
2487         if (ret) {
2488                 btrfs_handle_fs_error(fs_info, ret,
2489                                       "Failed to recover log tree");
2490                 free_extent_buffer(log_tree_root->node);
2491                 kfree(log_tree_root);
2492                 return ret;
2493         }
2494
2495         if (fs_info->sb->s_flags & MS_RDONLY) {
2496                 ret = btrfs_commit_super(fs_info);
2497                 if (ret)
2498                         return ret;
2499         }
2500
2501         return 0;
2502 }
2503
2504 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2505 {
2506         struct btrfs_root *tree_root = fs_info->tree_root;
2507         struct btrfs_root *root;
2508         struct btrfs_key location;
2509         int ret;
2510
2511         BUG_ON(!fs_info->tree_root);
2512
2513         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2514         location.type = BTRFS_ROOT_ITEM_KEY;
2515         location.offset = 0;
2516
2517         root = btrfs_read_tree_root(tree_root, &location);
2518         if (IS_ERR(root))
2519                 return PTR_ERR(root);
2520         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2521         fs_info->extent_root = root;
2522
2523         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2524         root = btrfs_read_tree_root(tree_root, &location);
2525         if (IS_ERR(root))
2526                 return PTR_ERR(root);
2527         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2528         fs_info->dev_root = root;
2529         btrfs_init_devices_late(fs_info);
2530
2531         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2532         root = btrfs_read_tree_root(tree_root, &location);
2533         if (IS_ERR(root))
2534                 return PTR_ERR(root);
2535         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2536         fs_info->csum_root = root;
2537
2538         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2539         root = btrfs_read_tree_root(tree_root, &location);
2540         if (!IS_ERR(root)) {
2541                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2542                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2543                 fs_info->quota_root = root;
2544         }
2545
2546         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2547         root = btrfs_read_tree_root(tree_root, &location);
2548         if (IS_ERR(root)) {
2549                 ret = PTR_ERR(root);
2550                 if (ret != -ENOENT)
2551                         return ret;
2552         } else {
2553                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2554                 fs_info->uuid_root = root;
2555         }
2556
2557         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2558                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2559                 root = btrfs_read_tree_root(tree_root, &location);
2560                 if (IS_ERR(root))
2561                         return PTR_ERR(root);
2562                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2563                 fs_info->free_space_root = root;
2564         }
2565
2566         return 0;
2567 }
2568
2569 int open_ctree(struct super_block *sb,
2570                struct btrfs_fs_devices *fs_devices,
2571                char *options)
2572 {
2573         u32 sectorsize;
2574         u32 nodesize;
2575         u32 stripesize;
2576         u64 generation;
2577         u64 features;
2578         struct btrfs_key location;
2579         struct buffer_head *bh;
2580         struct btrfs_super_block *disk_super;
2581         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2582         struct btrfs_root *tree_root;
2583         struct btrfs_root *chunk_root;
2584         int ret;
2585         int err = -EINVAL;
2586         int num_backups_tried = 0;
2587         int backup_index = 0;
2588         int max_active;
2589         int clear_free_space_tree = 0;
2590
2591         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2592         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2593         if (!tree_root || !chunk_root) {
2594                 err = -ENOMEM;
2595                 goto fail;
2596         }
2597
2598         ret = init_srcu_struct(&fs_info->subvol_srcu);
2599         if (ret) {
2600                 err = ret;
2601                 goto fail;
2602         }
2603
2604         ret = setup_bdi(fs_info, &fs_info->bdi);
2605         if (ret) {
2606                 err = ret;
2607                 goto fail_srcu;
2608         }
2609
2610         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2611         if (ret) {
2612                 err = ret;
2613                 goto fail_bdi;
2614         }
2615         fs_info->dirty_metadata_batch = PAGE_SIZE *
2616                                         (1 + ilog2(nr_cpu_ids));
2617
2618         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2619         if (ret) {
2620                 err = ret;
2621                 goto fail_dirty_metadata_bytes;
2622         }
2623
2624         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2625         if (ret) {
2626                 err = ret;
2627                 goto fail_delalloc_bytes;
2628         }
2629
2630         fs_info->btree_inode = new_inode(sb);
2631         if (!fs_info->btree_inode) {
2632                 err = -ENOMEM;
2633                 goto fail_bio_counter;
2634         }
2635
2636         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2637
2638         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2639         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2640         INIT_LIST_HEAD(&fs_info->trans_list);
2641         INIT_LIST_HEAD(&fs_info->dead_roots);
2642         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2643         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2644         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2645         spin_lock_init(&fs_info->delalloc_root_lock);
2646         spin_lock_init(&fs_info->trans_lock);
2647         spin_lock_init(&fs_info->fs_roots_radix_lock);
2648         spin_lock_init(&fs_info->delayed_iput_lock);
2649         spin_lock_init(&fs_info->defrag_inodes_lock);
2650         spin_lock_init(&fs_info->free_chunk_lock);
2651         spin_lock_init(&fs_info->tree_mod_seq_lock);
2652         spin_lock_init(&fs_info->super_lock);
2653         spin_lock_init(&fs_info->qgroup_op_lock);
2654         spin_lock_init(&fs_info->buffer_lock);
2655         spin_lock_init(&fs_info->unused_bgs_lock);
2656         rwlock_init(&fs_info->tree_mod_log_lock);
2657         mutex_init(&fs_info->unused_bg_unpin_mutex);
2658         mutex_init(&fs_info->delete_unused_bgs_mutex);
2659         mutex_init(&fs_info->reloc_mutex);
2660         mutex_init(&fs_info->delalloc_root_mutex);
2661         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2662         seqlock_init(&fs_info->profiles_lock);
2663
2664         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2665         INIT_LIST_HEAD(&fs_info->space_info);
2666         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2667         INIT_LIST_HEAD(&fs_info->unused_bgs);
2668         btrfs_mapping_init(&fs_info->mapping_tree);
2669         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2670                              BTRFS_BLOCK_RSV_GLOBAL);
2671         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2672                              BTRFS_BLOCK_RSV_DELALLOC);
2673         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2674         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2675         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2676         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2677                              BTRFS_BLOCK_RSV_DELOPS);
2678         atomic_set(&fs_info->nr_async_submits, 0);
2679         atomic_set(&fs_info->async_delalloc_pages, 0);
2680         atomic_set(&fs_info->async_submit_draining, 0);
2681         atomic_set(&fs_info->nr_async_bios, 0);
2682         atomic_set(&fs_info->defrag_running, 0);
2683         atomic_set(&fs_info->qgroup_op_seq, 0);
2684         atomic_set(&fs_info->reada_works_cnt, 0);
2685         atomic64_set(&fs_info->tree_mod_seq, 0);
2686         fs_info->fs_frozen = 0;
2687         fs_info->sb = sb;
2688         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2689         fs_info->metadata_ratio = 0;
2690         fs_info->defrag_inodes = RB_ROOT;
2691         fs_info->free_chunk_space = 0;
2692         fs_info->tree_mod_log = RB_ROOT;
2693         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2694         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2695         /* readahead state */
2696         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2697         spin_lock_init(&fs_info->reada_lock);
2698
2699         fs_info->thread_pool_size = min_t(unsigned long,
2700                                           num_online_cpus() + 2, 8);
2701
2702         INIT_LIST_HEAD(&fs_info->ordered_roots);
2703         spin_lock_init(&fs_info->ordered_root_lock);
2704         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2705                                         GFP_KERNEL);
2706         if (!fs_info->delayed_root) {
2707                 err = -ENOMEM;
2708                 goto fail_iput;
2709         }
2710         btrfs_init_delayed_root(fs_info->delayed_root);
2711
2712         btrfs_init_scrub(fs_info);
2713 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2714         fs_info->check_integrity_print_mask = 0;
2715 #endif
2716         btrfs_init_balance(fs_info);
2717         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2718
2719         sb->s_blocksize = 4096;
2720         sb->s_blocksize_bits = blksize_bits(4096);
2721         sb->s_bdi = &fs_info->bdi;
2722
2723         btrfs_init_btree_inode(fs_info);
2724
2725         spin_lock_init(&fs_info->block_group_cache_lock);
2726         fs_info->block_group_cache_tree = RB_ROOT;
2727         fs_info->first_logical_byte = (u64)-1;
2728
2729         extent_io_tree_init(&fs_info->freed_extents[0],
2730                              fs_info->btree_inode->i_mapping);
2731         extent_io_tree_init(&fs_info->freed_extents[1],
2732                              fs_info->btree_inode->i_mapping);
2733         fs_info->pinned_extents = &fs_info->freed_extents[0];
2734         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2735
2736         mutex_init(&fs_info->ordered_operations_mutex);
2737         mutex_init(&fs_info->tree_log_mutex);
2738         mutex_init(&fs_info->chunk_mutex);
2739         mutex_init(&fs_info->transaction_kthread_mutex);
2740         mutex_init(&fs_info->cleaner_mutex);
2741         mutex_init(&fs_info->volume_mutex);
2742         mutex_init(&fs_info->ro_block_group_mutex);
2743         init_rwsem(&fs_info->commit_root_sem);
2744         init_rwsem(&fs_info->cleanup_work_sem);
2745         init_rwsem(&fs_info->subvol_sem);
2746         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2747
2748         btrfs_init_dev_replace_locks(fs_info);
2749         btrfs_init_qgroup(fs_info);
2750
2751         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2752         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2753
2754         init_waitqueue_head(&fs_info->transaction_throttle);
2755         init_waitqueue_head(&fs_info->transaction_wait);
2756         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2757         init_waitqueue_head(&fs_info->async_submit_wait);
2758
2759         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2760
2761         /* Usable values until the real ones are cached from the superblock */
2762         fs_info->nodesize = 4096;
2763         fs_info->sectorsize = 4096;
2764         fs_info->stripesize = 4096;
2765
2766         ret = btrfs_alloc_stripe_hash_table(fs_info);
2767         if (ret) {
2768                 err = ret;
2769                 goto fail_alloc;
2770         }
2771
2772         __setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
2773
2774         invalidate_bdev(fs_devices->latest_bdev);
2775
2776         /*
2777          * Read super block and check the signature bytes only
2778          */
2779         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2780         if (IS_ERR(bh)) {
2781                 err = PTR_ERR(bh);
2782                 goto fail_alloc;
2783         }
2784
2785         /*
2786          * We want to check superblock checksum, the type is stored inside.
2787          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2788          */
2789         if (btrfs_check_super_csum(fs_info, bh->b_data)) {
2790                 btrfs_err(fs_info, "superblock checksum mismatch");
2791                 err = -EINVAL;
2792                 brelse(bh);
2793                 goto fail_alloc;
2794         }
2795
2796         /*
2797          * super_copy is zeroed at allocation time and we never touch the
2798          * following bytes up to INFO_SIZE, the checksum is calculated from
2799          * the whole block of INFO_SIZE
2800          */
2801         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2802         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2803                sizeof(*fs_info->super_for_commit));
2804         brelse(bh);
2805
2806         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2807
2808         ret = btrfs_check_super_valid(fs_info);
2809         if (ret) {
2810                 btrfs_err(fs_info, "superblock contains fatal errors");
2811                 err = -EINVAL;
2812                 goto fail_alloc;
2813         }
2814
2815         disk_super = fs_info->super_copy;
2816         if (!btrfs_super_root(disk_super))
2817                 goto fail_alloc;
2818
2819         /* check FS state, whether FS is broken. */
2820         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2821                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2822
2823         /*
2824          * run through our array of backup supers and setup
2825          * our ring pointer to the oldest one
2826          */
2827         generation = btrfs_super_generation(disk_super);
2828         find_oldest_super_backup(fs_info, generation);
2829
2830         /*
2831          * In the long term, we'll store the compression type in the super
2832          * block, and it'll be used for per file compression control.
2833          */
2834         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2835
2836         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
2837         if (ret) {
2838                 err = ret;
2839                 goto fail_alloc;
2840         }
2841
2842         features = btrfs_super_incompat_flags(disk_super) &
2843                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2844         if (features) {
2845                 btrfs_err(fs_info,
2846                     "cannot mount because of unsupported optional features (%llx)",
2847                     features);
2848                 err = -EINVAL;
2849                 goto fail_alloc;
2850         }
2851
2852         features = btrfs_super_incompat_flags(disk_super);
2853         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2854         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
2855                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2856
2857         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2858                 btrfs_info(fs_info, "has skinny extents");
2859
2860         /*
2861          * flag our filesystem as having big metadata blocks if
2862          * they are bigger than the page size
2863          */
2864         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2865                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2866                         btrfs_info(fs_info,
2867                                 "flagging fs with big metadata feature");
2868                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2869         }
2870
2871         nodesize = btrfs_super_nodesize(disk_super);
2872         sectorsize = btrfs_super_sectorsize(disk_super);
2873         stripesize = sectorsize;
2874         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2875         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2876
2877         /* Cache block sizes */
2878         fs_info->nodesize = nodesize;
2879         fs_info->sectorsize = sectorsize;
2880         fs_info->stripesize = stripesize;
2881
2882         /*
2883          * mixed block groups end up with duplicate but slightly offset
2884          * extent buffers for the same range.  It leads to corruptions
2885          */
2886         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2887             (sectorsize != nodesize)) {
2888                 btrfs_err(fs_info,
2889 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2890                         nodesize, sectorsize);
2891                 goto fail_alloc;
2892         }
2893
2894         /*
2895          * Needn't use the lock because there is no other task which will
2896          * update the flag.
2897          */
2898         btrfs_set_super_incompat_flags(disk_super, features);
2899
2900         features = btrfs_super_compat_ro_flags(disk_super) &
2901                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2902         if (!(sb->s_flags & MS_RDONLY) && features) {
2903                 btrfs_err(fs_info,
2904         "cannot mount read-write because of unsupported optional features (%llx)",
2905                        features);
2906                 err = -EINVAL;
2907                 goto fail_alloc;
2908         }
2909
2910         max_active = fs_info->thread_pool_size;
2911
2912         ret = btrfs_init_workqueues(fs_info, fs_devices);
2913         if (ret) {
2914                 err = ret;
2915                 goto fail_sb_buffer;
2916         }
2917
2918         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2919         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2920                                     SZ_4M / PAGE_SIZE);
2921
2922         sb->s_blocksize = sectorsize;
2923         sb->s_blocksize_bits = blksize_bits(sectorsize);
2924
2925         mutex_lock(&fs_info->chunk_mutex);
2926         ret = btrfs_read_sys_array(fs_info);
2927         mutex_unlock(&fs_info->chunk_mutex);
2928         if (ret) {
2929                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2930                 goto fail_sb_buffer;
2931         }
2932
2933         generation = btrfs_super_chunk_root_generation(disk_super);
2934
2935         __setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2936
2937         chunk_root->node = read_tree_block(fs_info,
2938                                            btrfs_super_chunk_root(disk_super),
2939                                            generation);
2940         if (IS_ERR(chunk_root->node) ||
2941             !extent_buffer_uptodate(chunk_root->node)) {
2942                 btrfs_err(fs_info, "failed to read chunk root");
2943                 if (!IS_ERR(chunk_root->node))
2944                         free_extent_buffer(chunk_root->node);
2945                 chunk_root->node = NULL;
2946                 goto fail_tree_roots;
2947         }
2948         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2949         chunk_root->commit_root = btrfs_root_node(chunk_root);
2950
2951         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2952            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2953
2954         ret = btrfs_read_chunk_tree(fs_info);
2955         if (ret) {
2956                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
2957                 goto fail_tree_roots;
2958         }
2959
2960         /*
2961          * keep the device that is marked to be the target device for the
2962          * dev_replace procedure
2963          */
2964         btrfs_close_extra_devices(fs_devices, 0);
2965
2966         if (!fs_devices->latest_bdev) {
2967                 btrfs_err(fs_info, "failed to read devices");
2968                 goto fail_tree_roots;
2969         }
2970
2971 retry_root_backup:
2972         generation = btrfs_super_generation(disk_super);
2973
2974         tree_root->node = read_tree_block(fs_info,
2975                                           btrfs_super_root(disk_super),
2976                                           generation);
2977         if (IS_ERR(tree_root->node) ||
2978             !extent_buffer_uptodate(tree_root->node)) {
2979                 btrfs_warn(fs_info, "failed to read tree root");
2980                 if (!IS_ERR(tree_root->node))
2981                         free_extent_buffer(tree_root->node);
2982                 tree_root->node = NULL;
2983                 goto recovery_tree_root;
2984         }
2985
2986         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2987         tree_root->commit_root = btrfs_root_node(tree_root);
2988         btrfs_set_root_refs(&tree_root->root_item, 1);
2989
2990         mutex_lock(&tree_root->objectid_mutex);
2991         ret = btrfs_find_highest_objectid(tree_root,
2992                                         &tree_root->highest_objectid);
2993         if (ret) {
2994                 mutex_unlock(&tree_root->objectid_mutex);
2995                 goto recovery_tree_root;
2996         }
2997
2998         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
2999
3000         mutex_unlock(&tree_root->objectid_mutex);
3001
3002         ret = btrfs_read_roots(fs_info);
3003         if (ret)
3004                 goto recovery_tree_root;
3005
3006         fs_info->generation = generation;
3007         fs_info->last_trans_committed = generation;
3008
3009         ret = btrfs_recover_balance(fs_info);
3010         if (ret) {
3011                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3012                 goto fail_block_groups;
3013         }
3014
3015         ret = btrfs_init_dev_stats(fs_info);
3016         if (ret) {
3017                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3018                 goto fail_block_groups;
3019         }
3020
3021         ret = btrfs_init_dev_replace(fs_info);
3022         if (ret) {
3023                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3024                 goto fail_block_groups;
3025         }
3026
3027         btrfs_close_extra_devices(fs_devices, 1);
3028
3029         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
3030         if (ret) {
3031                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3032                                 ret);
3033                 goto fail_block_groups;
3034         }
3035
3036         ret = btrfs_sysfs_add_device(fs_devices);
3037         if (ret) {
3038                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
3039                                 ret);
3040                 goto fail_fsdev_sysfs;
3041         }
3042
3043         ret = btrfs_sysfs_add_mounted(fs_info);
3044         if (ret) {
3045                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3046                 goto fail_fsdev_sysfs;
3047         }
3048
3049         ret = btrfs_init_space_info(fs_info);
3050         if (ret) {
3051                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3052                 goto fail_sysfs;
3053         }
3054
3055         ret = btrfs_read_block_groups(fs_info);
3056         if (ret) {
3057                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3058                 goto fail_sysfs;
3059         }
3060         fs_info->num_tolerated_disk_barrier_failures =
3061                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3062         if (fs_info->fs_devices->missing_devices >
3063              fs_info->num_tolerated_disk_barrier_failures &&
3064             !(sb->s_flags & MS_RDONLY)) {
3065                 btrfs_warn(fs_info,
3066 "missing devices (%llu) exceeds the limit (%d), writeable mount is not allowed",
3067                         fs_info->fs_devices->missing_devices,
3068                         fs_info->num_tolerated_disk_barrier_failures);
3069                 goto fail_sysfs;
3070         }
3071
3072         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3073                                                "btrfs-cleaner");
3074         if (IS_ERR(fs_info->cleaner_kthread))
3075                 goto fail_sysfs;
3076
3077         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3078                                                    tree_root,
3079                                                    "btrfs-transaction");
3080         if (IS_ERR(fs_info->transaction_kthread))
3081                 goto fail_cleaner;
3082
3083         if (!btrfs_test_opt(fs_info, SSD) &&
3084             !btrfs_test_opt(fs_info, NOSSD) &&
3085             !fs_info->fs_devices->rotating) {
3086                 btrfs_info(fs_info, "detected SSD devices, enabling SSD mode");
3087                 btrfs_set_opt(fs_info->mount_opt, SSD);
3088         }
3089
3090         /*
3091          * Mount does not set all options immediately, we can do it now and do
3092          * not have to wait for transaction commit
3093          */
3094         btrfs_apply_pending_changes(fs_info);
3095
3096 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3097         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3098                 ret = btrfsic_mount(fs_info, fs_devices,
3099                                     btrfs_test_opt(fs_info,
3100                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3101                                     1 : 0,
3102                                     fs_info->check_integrity_print_mask);
3103                 if (ret)
3104                         btrfs_warn(fs_info,
3105                                 "failed to initialize integrity check module: %d",
3106                                 ret);
3107         }
3108 #endif
3109         ret = btrfs_read_qgroup_config(fs_info);
3110         if (ret)
3111                 goto fail_trans_kthread;
3112
3113         /* do not make disk changes in broken FS or nologreplay is given */
3114         if (btrfs_super_log_root(disk_super) != 0 &&
3115             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3116                 ret = btrfs_replay_log(fs_info, fs_devices);
3117                 if (ret) {
3118                         err = ret;
3119                         goto fail_qgroup;
3120                 }
3121         }
3122
3123         ret = btrfs_find_orphan_roots(fs_info);
3124         if (ret)
3125                 goto fail_qgroup;
3126
3127         if (!(sb->s_flags & MS_RDONLY)) {
3128                 ret = btrfs_cleanup_fs_roots(fs_info);
3129                 if (ret)
3130                         goto fail_qgroup;
3131
3132                 mutex_lock(&fs_info->cleaner_mutex);
3133                 ret = btrfs_recover_relocation(tree_root);
3134                 mutex_unlock(&fs_info->cleaner_mutex);
3135                 if (ret < 0) {
3136                         btrfs_warn(fs_info, "failed to recover relocation: %d",
3137                                         ret);
3138                         err = -EINVAL;
3139                         goto fail_qgroup;
3140                 }
3141         }
3142
3143         location.objectid = BTRFS_FS_TREE_OBJECTID;
3144         location.type = BTRFS_ROOT_ITEM_KEY;
3145         location.offset = 0;
3146
3147         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3148         if (IS_ERR(fs_info->fs_root)) {
3149                 err = PTR_ERR(fs_info->fs_root);
3150                 goto fail_qgroup;
3151         }
3152
3153         if (sb->s_flags & MS_RDONLY)
3154                 return 0;
3155
3156         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3157             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3158                 clear_free_space_tree = 1;
3159         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3160                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3161                 btrfs_warn(fs_info, "free space tree is invalid");
3162                 clear_free_space_tree = 1;
3163         }
3164
3165         if (clear_free_space_tree) {
3166                 btrfs_info(fs_info, "clearing free space tree");
3167                 ret = btrfs_clear_free_space_tree(fs_info);
3168                 if (ret) {
3169                         btrfs_warn(fs_info,
3170                                    "failed to clear free space tree: %d", ret);
3171                         close_ctree(fs_info);
3172                         return ret;
3173                 }
3174         }
3175
3176         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3177             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3178                 btrfs_info(fs_info, "creating free space tree");
3179                 ret = btrfs_create_free_space_tree(fs_info);
3180                 if (ret) {
3181                         btrfs_warn(fs_info,
3182                                 "failed to create free space tree: %d", ret);
3183                         close_ctree(fs_info);
3184                         return ret;
3185                 }
3186         }
3187
3188         down_read(&fs_info->cleanup_work_sem);
3189         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3190             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3191                 up_read(&fs_info->cleanup_work_sem);
3192                 close_ctree(fs_info);
3193                 return ret;
3194         }
3195         up_read(&fs_info->cleanup_work_sem);
3196
3197         ret = btrfs_resume_balance_async(fs_info);
3198         if (ret) {
3199                 btrfs_warn(fs_info, "failed to resume balance: %d", ret);
3200                 close_ctree(fs_info);
3201                 return ret;
3202         }
3203
3204         ret = btrfs_resume_dev_replace_async(fs_info);
3205         if (ret) {
3206                 btrfs_warn(fs_info, "failed to resume device replace: %d", ret);
3207                 close_ctree(fs_info);
3208                 return ret;
3209         }
3210
3211         btrfs_qgroup_rescan_resume(fs_info);
3212
3213         if (!fs_info->uuid_root) {
3214                 btrfs_info(fs_info, "creating UUID tree");
3215                 ret = btrfs_create_uuid_tree(fs_info);
3216                 if (ret) {
3217                         btrfs_warn(fs_info,
3218                                 "failed to create the UUID tree: %d", ret);
3219                         close_ctree(fs_info);
3220                         return ret;
3221                 }
3222         } else if (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3223                    fs_info->generation !=
3224                                 btrfs_super_uuid_tree_generation(disk_super)) {
3225                 btrfs_info(fs_info, "checking UUID tree");
3226                 ret = btrfs_check_uuid_tree(fs_info);
3227                 if (ret) {
3228                         btrfs_warn(fs_info,
3229                                 "failed to check the UUID tree: %d", ret);
3230                         close_ctree(fs_info);
3231                         return ret;
3232                 }
3233         } else {
3234                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3235         }
3236         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3237
3238         /*
3239          * backuproot only affect mount behavior, and if open_ctree succeeded,
3240          * no need to keep the flag
3241          */
3242         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3243
3244         return 0;
3245
3246 fail_qgroup:
3247         btrfs_free_qgroup_config(fs_info);
3248 fail_trans_kthread:
3249         kthread_stop(fs_info->transaction_kthread);
3250         btrfs_cleanup_transaction(fs_info);
3251         btrfs_free_fs_roots(fs_info);
3252 fail_cleaner:
3253         kthread_stop(fs_info->cleaner_kthread);
3254
3255         /*
3256          * make sure we're done with the btree inode before we stop our
3257          * kthreads
3258          */
3259         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3260
3261 fail_sysfs:
3262         btrfs_sysfs_remove_mounted(fs_info);
3263
3264 fail_fsdev_sysfs:
3265         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3266
3267 fail_block_groups:
3268         btrfs_put_block_group_cache(fs_info);
3269
3270 fail_tree_roots:
3271         free_root_pointers(fs_info, 1);
3272         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3273
3274 fail_sb_buffer:
3275         btrfs_stop_all_workers(fs_info);
3276         btrfs_free_block_groups(fs_info);
3277 fail_alloc:
3278 fail_iput:
3279         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3280
3281         iput(fs_info->btree_inode);
3282 fail_bio_counter:
3283         percpu_counter_destroy(&fs_info->bio_counter);
3284 fail_delalloc_bytes:
3285         percpu_counter_destroy(&fs_info->delalloc_bytes);
3286 fail_dirty_metadata_bytes:
3287         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3288 fail_bdi:
3289         bdi_destroy(&fs_info->bdi);
3290 fail_srcu:
3291         cleanup_srcu_struct(&fs_info->subvol_srcu);
3292 fail:
3293         btrfs_free_stripe_hash_table(fs_info);
3294         btrfs_close_devices(fs_info->fs_devices);
3295         return err;
3296
3297 recovery_tree_root:
3298         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
3299                 goto fail_tree_roots;
3300
3301         free_root_pointers(fs_info, 0);
3302
3303         /* don't use the log in recovery mode, it won't be valid */
3304         btrfs_set_super_log_root(disk_super, 0);
3305
3306         /* we can't trust the free space cache either */
3307         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3308
3309         ret = next_root_backup(fs_info, fs_info->super_copy,
3310                                &num_backups_tried, &backup_index);
3311         if (ret == -1)
3312                 goto fail_block_groups;
3313         goto retry_root_backup;
3314 }
3315
3316 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3317 {
3318         if (uptodate) {
3319                 set_buffer_uptodate(bh);
3320         } else {
3321                 struct btrfs_device *device = (struct btrfs_device *)
3322                         bh->b_private;
3323
3324                 btrfs_warn_rl_in_rcu(device->fs_info,
3325                                 "lost page write due to IO error on %s",
3326                                           rcu_str_deref(device->name));
3327                 /* note, we don't set_buffer_write_io_error because we have
3328                  * our own ways of dealing with the IO errors
3329                  */
3330                 clear_buffer_uptodate(bh);
3331                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3332         }
3333         unlock_buffer(bh);
3334         put_bh(bh);
3335 }
3336
3337 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
3338                         struct buffer_head **bh_ret)
3339 {
3340         struct buffer_head *bh;
3341         struct btrfs_super_block *super;
3342         u64 bytenr;
3343
3344         bytenr = btrfs_sb_offset(copy_num);
3345         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3346                 return -EINVAL;
3347
3348         bh = __bread(bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE);
3349         /*
3350          * If we fail to read from the underlying devices, as of now
3351          * the best option we have is to mark it EIO.
3352          */
3353         if (!bh)
3354                 return -EIO;
3355
3356         super = (struct btrfs_super_block *)bh->b_data;
3357         if (btrfs_super_bytenr(super) != bytenr ||
3358                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3359                 brelse(bh);
3360                 return -EINVAL;
3361         }
3362
3363         *bh_ret = bh;
3364         return 0;
3365 }
3366
3367
3368 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3369 {
3370         struct buffer_head *bh;
3371         struct buffer_head *latest = NULL;
3372         struct btrfs_super_block *super;
3373         int i;
3374         u64 transid = 0;
3375         int ret = -EINVAL;
3376
3377         /* we would like to check all the supers, but that would make
3378          * a btrfs mount succeed after a mkfs from a different FS.
3379          * So, we need to add a special mount option to scan for
3380          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3381          */
3382         for (i = 0; i < 1; i++) {
3383                 ret = btrfs_read_dev_one_super(bdev, i, &bh);
3384                 if (ret)
3385                         continue;
3386
3387                 super = (struct btrfs_super_block *)bh->b_data;
3388
3389                 if (!latest || btrfs_super_generation(super) > transid) {
3390                         brelse(latest);
3391                         latest = bh;
3392                         transid = btrfs_super_generation(super);
3393                 } else {
3394                         brelse(bh);
3395                 }
3396         }
3397
3398         if (!latest)
3399                 return ERR_PTR(ret);
3400
3401         return latest;
3402 }
3403
3404 /*
3405  * this should be called twice, once with wait == 0 and
3406  * once with wait == 1.  When wait == 0 is done, all the buffer heads
3407  * we write are pinned.
3408  *
3409  * They are released when wait == 1 is done.
3410  * max_mirrors must be the same for both runs, and it indicates how
3411  * many supers on this one device should be written.
3412  *
3413  * max_mirrors == 0 means to write them all.
3414  */
3415 static int write_dev_supers(struct btrfs_device *device,
3416                             struct btrfs_super_block *sb,
3417                             int wait, int max_mirrors)
3418 {
3419         struct buffer_head *bh;
3420         int i;
3421         int ret;
3422         int errors = 0;
3423         u32 crc;
3424         u64 bytenr;
3425
3426         if (max_mirrors == 0)
3427                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3428
3429         for (i = 0; i < max_mirrors; i++) {
3430                 bytenr = btrfs_sb_offset(i);
3431                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3432                     device->commit_total_bytes)
3433                         break;
3434
3435                 if (wait) {
3436                         bh = __find_get_block(device->bdev, bytenr / 4096,
3437                                               BTRFS_SUPER_INFO_SIZE);
3438                         if (!bh) {
3439                                 errors++;
3440                          &nb