87dad552e39ae13ea2533c4a5718a5af635bcbee
[sfrench/cifs-2.6.git] / fs / btrfs / disk-io.c
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/slab.h>
29 #include <linux/migrate.h>
30 #include <linux/ratelimit.h>
31 #include <linux/uuid.h>
32 #include <linux/semaphore.h>
33 #include <asm/unaligned.h>
34 #include "ctree.h"
35 #include "disk-io.h"
36 #include "hash.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "locking.h"
42 #include "tree-log.h"
43 #include "free-space-cache.h"
44 #include "free-space-tree.h"
45 #include "inode-map.h"
46 #include "check-integrity.h"
47 #include "rcu-string.h"
48 #include "dev-replace.h"
49 #include "raid56.h"
50 #include "sysfs.h"
51 #include "qgroup.h"
52 #include "compression.h"
53
54 #ifdef CONFIG_X86
55 #include <asm/cpufeature.h>
56 #endif
57
58 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
59                                  BTRFS_HEADER_FLAG_RELOC |\
60                                  BTRFS_SUPER_FLAG_ERROR |\
61                                  BTRFS_SUPER_FLAG_SEEDING |\
62                                  BTRFS_SUPER_FLAG_METADUMP)
63
64 static const struct extent_io_ops btree_extent_io_ops;
65 static void end_workqueue_fn(struct btrfs_work *work);
66 static void free_fs_root(struct btrfs_root *root);
67 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
68                                     int read_only);
69 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
70 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
71                                       struct btrfs_root *root);
72 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
73 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
74                                         struct extent_io_tree *dirty_pages,
75                                         int mark);
76 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
77                                        struct extent_io_tree *pinned_extents);
78 static int btrfs_cleanup_transaction(struct btrfs_root *root);
79 static void btrfs_error_commit_super(struct btrfs_root *root);
80
81 /*
82  * btrfs_end_io_wq structs are used to do processing in task context when an IO
83  * is complete.  This is used during reads to verify checksums, and it is used
84  * by writes to insert metadata for new file extents after IO is complete.
85  */
86 struct btrfs_end_io_wq {
87         struct bio *bio;
88         bio_end_io_t *end_io;
89         void *private;
90         struct btrfs_fs_info *info;
91         int error;
92         enum btrfs_wq_endio_type metadata;
93         struct list_head list;
94         struct btrfs_work work;
95 };
96
97 static struct kmem_cache *btrfs_end_io_wq_cache;
98
99 int __init btrfs_end_io_wq_init(void)
100 {
101         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
102                                         sizeof(struct btrfs_end_io_wq),
103                                         0,
104                                         SLAB_MEM_SPREAD,
105                                         NULL);
106         if (!btrfs_end_io_wq_cache)
107                 return -ENOMEM;
108         return 0;
109 }
110
111 void btrfs_end_io_wq_exit(void)
112 {
113         kmem_cache_destroy(btrfs_end_io_wq_cache);
114 }
115
116 /*
117  * async submit bios are used to offload expensive checksumming
118  * onto the worker threads.  They checksum file and metadata bios
119  * just before they are sent down the IO stack.
120  */
121 struct async_submit_bio {
122         struct inode *inode;
123         struct bio *bio;
124         struct list_head list;
125         extent_submit_bio_hook_t *submit_bio_start;
126         extent_submit_bio_hook_t *submit_bio_done;
127         int mirror_num;
128         unsigned long bio_flags;
129         /*
130          * bio_offset is optional, can be used if the pages in the bio
131          * can't tell us where in the file the bio should go
132          */
133         u64 bio_offset;
134         struct btrfs_work work;
135         int error;
136 };
137
138 /*
139  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
140  * eb, the lockdep key is determined by the btrfs_root it belongs to and
141  * the level the eb occupies in the tree.
142  *
143  * Different roots are used for different purposes and may nest inside each
144  * other and they require separate keysets.  As lockdep keys should be
145  * static, assign keysets according to the purpose of the root as indicated
146  * by btrfs_root->objectid.  This ensures that all special purpose roots
147  * have separate keysets.
148  *
149  * Lock-nesting across peer nodes is always done with the immediate parent
150  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
151  * subclass to avoid triggering lockdep warning in such cases.
152  *
153  * The key is set by the readpage_end_io_hook after the buffer has passed
154  * csum validation but before the pages are unlocked.  It is also set by
155  * btrfs_init_new_buffer on freshly allocated blocks.
156  *
157  * We also add a check to make sure the highest level of the tree is the
158  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
159  * needs update as well.
160  */
161 #ifdef CONFIG_DEBUG_LOCK_ALLOC
162 # if BTRFS_MAX_LEVEL != 8
163 #  error
164 # endif
165
166 static struct btrfs_lockdep_keyset {
167         u64                     id;             /* root objectid */
168         const char              *name_stem;     /* lock name stem */
169         char                    names[BTRFS_MAX_LEVEL + 1][20];
170         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
171 } btrfs_lockdep_keysets[] = {
172         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
173         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
174         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
175         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
176         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
177         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
178         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
179         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
180         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
181         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
182         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
183         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, .name_stem = "free-space" },
184         { .id = 0,                              .name_stem = "tree"     },
185 };
186
187 void __init btrfs_init_lockdep(void)
188 {
189         int i, j;
190
191         /* initialize lockdep class names */
192         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
193                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
194
195                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
196                         snprintf(ks->names[j], sizeof(ks->names[j]),
197                                  "btrfs-%s-%02d", ks->name_stem, j);
198         }
199 }
200
201 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
202                                     int level)
203 {
204         struct btrfs_lockdep_keyset *ks;
205
206         BUG_ON(level >= ARRAY_SIZE(ks->keys));
207
208         /* find the matching keyset, id 0 is the default entry */
209         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
210                 if (ks->id == objectid)
211                         break;
212
213         lockdep_set_class_and_name(&eb->lock,
214                                    &ks->keys[level], ks->names[level]);
215 }
216
217 #endif
218
219 /*
220  * extents on the btree inode are pretty simple, there's one extent
221  * that covers the entire device
222  */
223 static struct extent_map *btree_get_extent(struct inode *inode,
224                 struct page *page, size_t pg_offset, u64 start, u64 len,
225                 int create)
226 {
227         struct extent_map_tree *em_tree = &BTRFS_I(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 =
235                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
236                 read_unlock(&em_tree->lock);
237                 goto out;
238         }
239         read_unlock(&em_tree->lock);
240
241         em = alloc_extent_map();
242         if (!em) {
243                 em = ERR_PTR(-ENOMEM);
244                 goto out;
245         }
246         em->start = 0;
247         em->len = (u64)-1;
248         em->block_len = (u64)-1;
249         em->block_start = 0;
250         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
251
252         write_lock(&em_tree->lock);
253         ret = add_extent_mapping(em_tree, em, 0);
254         if (ret == -EEXIST) {
255                 free_extent_map(em);
256                 em = lookup_extent_mapping(em_tree, start, len);
257                 if (!em)
258                         em = ERR_PTR(-EIO);
259         } else if (ret) {
260                 free_extent_map(em);
261                 em = ERR_PTR(ret);
262         }
263         write_unlock(&em_tree->lock);
264
265 out:
266         return em;
267 }
268
269 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
270 {
271         return btrfs_crc32c(seed, data, len);
272 }
273
274 void btrfs_csum_final(u32 crc, char *result)
275 {
276         put_unaligned_le32(~crc, result);
277 }
278
279 /*
280  * compute the csum for a btree block, and either verify it or write it
281  * into the csum field of the block.
282  */
283 static int csum_tree_block(struct btrfs_fs_info *fs_info,
284                            struct extent_buffer *buf,
285                            int verify)
286 {
287         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
288         char *result = NULL;
289         unsigned long len;
290         unsigned long cur_len;
291         unsigned long offset = BTRFS_CSUM_SIZE;
292         char *kaddr;
293         unsigned long map_start;
294         unsigned long map_len;
295         int err;
296         u32 crc = ~(u32)0;
297         unsigned long inline_result;
298
299         len = buf->len - offset;
300         while (len > 0) {
301                 err = map_private_extent_buffer(buf, offset, 32,
302                                         &kaddr, &map_start, &map_len);
303                 if (err)
304                         return err;
305                 cur_len = min(len, map_len - (offset - map_start));
306                 crc = btrfs_csum_data(kaddr + offset - map_start,
307                                       crc, cur_len);
308                 len -= cur_len;
309                 offset += cur_len;
310         }
311         if (csum_size > sizeof(inline_result)) {
312                 result = kzalloc(csum_size, GFP_NOFS);
313                 if (!result)
314                         return -ENOMEM;
315         } else {
316                 result = (char *)&inline_result;
317         }
318
319         btrfs_csum_final(crc, result);
320
321         if (verify) {
322                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
323                         u32 val;
324                         u32 found = 0;
325                         memcpy(&found, result, csum_size);
326
327                         read_extent_buffer(buf, &val, 0, csum_size);
328                         btrfs_warn_rl(fs_info,
329                                 "%s checksum verify failed on %llu wanted %X found %X "
330                                 "level %d",
331                                 fs_info->sb->s_id, buf->start,
332                                 val, found, btrfs_header_level(buf));
333                         if (result != (char *)&inline_result)
334                                 kfree(result);
335                         return -EUCLEAN;
336                 }
337         } else {
338                 write_extent_buffer(buf, result, 0, csum_size);
339         }
340         if (result != (char *)&inline_result)
341                 kfree(result);
342         return 0;
343 }
344
345 /*
346  * we can't consider a given block up to date unless the transid of the
347  * block matches the transid in the parent node's pointer.  This is how we
348  * detect blocks that either didn't get written at all or got written
349  * in the wrong place.
350  */
351 static int verify_parent_transid(struct extent_io_tree *io_tree,
352                                  struct extent_buffer *eb, u64 parent_transid,
353                                  int atomic)
354 {
355         struct extent_state *cached_state = NULL;
356         int ret;
357         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
358
359         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
360                 return 0;
361
362         if (atomic)
363                 return -EAGAIN;
364
365         if (need_lock) {
366                 btrfs_tree_read_lock(eb);
367                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
368         }
369
370         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
371                          &cached_state);
372         if (extent_buffer_uptodate(eb) &&
373             btrfs_header_generation(eb) == parent_transid) {
374                 ret = 0;
375                 goto out;
376         }
377         btrfs_err_rl(eb->fs_info,
378                 "parent transid verify failed on %llu wanted %llu found %llu",
379                         eb->start,
380                         parent_transid, btrfs_header_generation(eb));
381         ret = 1;
382
383         /*
384          * Things reading via commit roots that don't have normal protection,
385          * like send, can have a really old block in cache that may point at a
386          * block that has been freed and re-allocated.  So don't clear uptodate
387          * if we find an eb that is under IO (dirty/writeback) because we could
388          * end up reading in the stale data and then writing it back out and
389          * making everybody very sad.
390          */
391         if (!extent_buffer_under_io(eb))
392                 clear_extent_buffer_uptodate(eb);
393 out:
394         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
395                              &cached_state, GFP_NOFS);
396         if (need_lock)
397                 btrfs_tree_read_unlock_blocking(eb);
398         return ret;
399 }
400
401 /*
402  * Return 0 if the superblock checksum type matches the checksum value of that
403  * algorithm. Pass the raw disk superblock data.
404  */
405 static int btrfs_check_super_csum(char *raw_disk_sb)
406 {
407         struct btrfs_super_block *disk_sb =
408                 (struct btrfs_super_block *)raw_disk_sb;
409         u16 csum_type = btrfs_super_csum_type(disk_sb);
410         int ret = 0;
411
412         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
413                 u32 crc = ~(u32)0;
414                 const int csum_size = sizeof(crc);
415                 char result[csum_size];
416
417                 /*
418                  * The super_block structure does not span the whole
419                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
420                  * is filled with zeros and is included in the checksum.
421                  */
422                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
423                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
424                 btrfs_csum_final(crc, result);
425
426                 if (memcmp(raw_disk_sb, result, csum_size))
427                         ret = 1;
428         }
429
430         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
431                 printk(KERN_ERR "BTRFS: unsupported checksum algorithm %u\n",
432                                 csum_type);
433                 ret = 1;
434         }
435
436         return ret;
437 }
438
439 /*
440  * helper to read a given tree block, doing retries as required when
441  * the checksums don't match and we have alternate mirrors to try.
442  */
443 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
444                                           struct extent_buffer *eb,
445                                           u64 start, u64 parent_transid)
446 {
447         struct extent_io_tree *io_tree;
448         int failed = 0;
449         int ret;
450         int num_copies = 0;
451         int mirror_num = 0;
452         int failed_mirror = 0;
453
454         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
455         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
456         while (1) {
457                 ret = read_extent_buffer_pages(io_tree, eb, start,
458                                                WAIT_COMPLETE,
459                                                btree_get_extent, mirror_num);
460                 if (!ret) {
461                         if (!verify_parent_transid(io_tree, eb,
462                                                    parent_transid, 0))
463                                 break;
464                         else
465                                 ret = -EIO;
466                 }
467
468                 /*
469                  * This buffer's crc is fine, but its contents are corrupted, so
470                  * there is no reason to read the other copies, they won't be
471                  * any less wrong.
472                  */
473                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
474                         break;
475
476                 num_copies = btrfs_num_copies(root->fs_info,
477                                               eb->start, eb->len);
478                 if (num_copies == 1)
479                         break;
480
481                 if (!failed_mirror) {
482                         failed = 1;
483                         failed_mirror = eb->read_mirror;
484                 }
485
486                 mirror_num++;
487                 if (mirror_num == failed_mirror)
488                         mirror_num++;
489
490                 if (mirror_num > num_copies)
491                         break;
492         }
493
494         if (failed && !ret && failed_mirror)
495                 repair_eb_io_failure(root, eb, failed_mirror);
496
497         return ret;
498 }
499
500 /*
501  * checksum a dirty tree block before IO.  This has extra checks to make sure
502  * we only fill in the checksum field in the first page of a multi-page block
503  */
504
505 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
506 {
507         u64 start = page_offset(page);
508         u64 found_start;
509         struct extent_buffer *eb;
510
511         eb = (struct extent_buffer *)page->private;
512         if (page != eb->pages[0])
513                 return 0;
514
515         found_start = btrfs_header_bytenr(eb);
516         /*
517          * Please do not consolidate these warnings into a single if.
518          * It is useful to know what went wrong.
519          */
520         if (WARN_ON(found_start != start))
521                 return -EUCLEAN;
522         if (WARN_ON(!PageUptodate(page)))
523                 return -EUCLEAN;
524
525         ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
526                         btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
527
528         return csum_tree_block(fs_info, eb, 0);
529 }
530
531 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
532                                  struct extent_buffer *eb)
533 {
534         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
535         u8 fsid[BTRFS_UUID_SIZE];
536         int ret = 1;
537
538         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
539         while (fs_devices) {
540                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
541                         ret = 0;
542                         break;
543                 }
544                 fs_devices = fs_devices->seed;
545         }
546         return ret;
547 }
548
549 #define CORRUPT(reason, eb, root, slot)                         \
550         btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu,"       \
551                    "root=%llu, slot=%d", reason,                        \
552                btrfs_header_bytenr(eb), root->objectid, slot)
553
554 static noinline int check_leaf(struct btrfs_root *root,
555                                struct extent_buffer *leaf)
556 {
557         struct btrfs_key key;
558         struct btrfs_key leaf_key;
559         u32 nritems = btrfs_header_nritems(leaf);
560         int slot;
561
562         if (nritems == 0)
563                 return 0;
564
565         /* Check the 0 item */
566         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
567             BTRFS_LEAF_DATA_SIZE(root)) {
568                 CORRUPT("invalid item offset size pair", leaf, root, 0);
569                 return -EIO;
570         }
571
572         /*
573          * Check to make sure each items keys are in the correct order and their
574          * offsets make sense.  We only have to loop through nritems-1 because
575          * we check the current slot against the next slot, which verifies the
576          * next slot's offset+size makes sense and that the current's slot
577          * offset is correct.
578          */
579         for (slot = 0; slot < nritems - 1; slot++) {
580                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
581                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
582
583                 /* Make sure the keys are in the right order */
584                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
585                         CORRUPT("bad key order", leaf, root, slot);
586                         return -EIO;
587                 }
588
589                 /*
590                  * Make sure the offset and ends are right, remember that the
591                  * item data starts at the end of the leaf and grows towards the
592                  * front.
593                  */
594                 if (btrfs_item_offset_nr(leaf, slot) !=
595                         btrfs_item_end_nr(leaf, slot + 1)) {
596                         CORRUPT("slot offset bad", leaf, root, slot);
597                         return -EIO;
598                 }
599
600                 /*
601                  * Check to make sure that we don't point outside of the leaf,
602                  * just in case all the items are consistent to each other, but
603                  * all point outside of the leaf.
604                  */
605                 if (btrfs_item_end_nr(leaf, slot) >
606                     BTRFS_LEAF_DATA_SIZE(root)) {
607                         CORRUPT("slot end outside of leaf", leaf, root, slot);
608                         return -EIO;
609                 }
610         }
611
612         return 0;
613 }
614
615 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
616                                       u64 phy_offset, struct page *page,
617                                       u64 start, u64 end, int mirror)
618 {
619         u64 found_start;
620         int found_level;
621         struct extent_buffer *eb;
622         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
623         struct btrfs_fs_info *fs_info = root->fs_info;
624         int ret = 0;
625         int reads_done;
626
627         if (!page->private)
628                 goto out;
629
630         eb = (struct extent_buffer *)page->private;
631
632         /* the pending IO might have been the only thing that kept this buffer
633          * in memory.  Make sure we have a ref for all this other checks
634          */
635         extent_buffer_get(eb);
636
637         reads_done = atomic_dec_and_test(&eb->io_pages);
638         if (!reads_done)
639                 goto err;
640
641         eb->read_mirror = mirror;
642         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
643                 ret = -EIO;
644                 goto err;
645         }
646
647         found_start = btrfs_header_bytenr(eb);
648         if (found_start != eb->start) {
649                 btrfs_err_rl(fs_info, "bad tree block start %llu %llu",
650                              found_start, eb->start);
651                 ret = -EIO;
652                 goto err;
653         }
654         if (check_tree_block_fsid(fs_info, eb)) {
655                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
656                              eb->start);
657                 ret = -EIO;
658                 goto err;
659         }
660         found_level = btrfs_header_level(eb);
661         if (found_level >= BTRFS_MAX_LEVEL) {
662                 btrfs_err(fs_info, "bad tree block level %d",
663                           (int)btrfs_header_level(eb));
664                 ret = -EIO;
665                 goto err;
666         }
667
668         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
669                                        eb, found_level);
670
671         ret = csum_tree_block(fs_info, eb, 1);
672         if (ret)
673                 goto err;
674
675         /*
676          * If this is a leaf block and it is corrupt, set the corrupt bit so
677          * that we don't try and read the other copies of this block, just
678          * return -EIO.
679          */
680         if (found_level == 0 && check_leaf(root, eb)) {
681                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
682                 ret = -EIO;
683         }
684
685         if (!ret)
686                 set_extent_buffer_uptodate(eb);
687 err:
688         if (reads_done &&
689             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
690                 btree_readahead_hook(fs_info, eb, eb->start, ret);
691
692         if (ret) {
693                 /*
694                  * our io error hook is going to dec the io pages
695                  * again, we have to make sure it has something
696                  * to decrement
697                  */
698                 atomic_inc(&eb->io_pages);
699                 clear_extent_buffer_uptodate(eb);
700         }
701         free_extent_buffer(eb);
702 out:
703         return ret;
704 }
705
706 static int btree_io_failed_hook(struct page *page, int failed_mirror)
707 {
708         struct extent_buffer *eb;
709
710         eb = (struct extent_buffer *)page->private;
711         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
712         eb->read_mirror = failed_mirror;
713         atomic_dec(&eb->io_pages);
714         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
715                 btree_readahead_hook(eb->fs_info, eb, eb->start, -EIO);
716         return -EIO;    /* we fixed nothing */
717 }
718
719 static void end_workqueue_bio(struct bio *bio)
720 {
721         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
722         struct btrfs_fs_info *fs_info;
723         struct btrfs_workqueue *wq;
724         btrfs_work_func_t func;
725
726         fs_info = end_io_wq->info;
727         end_io_wq->error = bio->bi_error;
728
729         if (bio_op(bio) == REQ_OP_WRITE) {
730                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
731                         wq = fs_info->endio_meta_write_workers;
732                         func = btrfs_endio_meta_write_helper;
733                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
734                         wq = fs_info->endio_freespace_worker;
735                         func = btrfs_freespace_write_helper;
736                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
737                         wq = fs_info->endio_raid56_workers;
738                         func = btrfs_endio_raid56_helper;
739                 } else {
740                         wq = fs_info->endio_write_workers;
741                         func = btrfs_endio_write_helper;
742                 }
743         } else {
744                 if (unlikely(end_io_wq->metadata ==
745                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
746                         wq = fs_info->endio_repair_workers;
747                         func = btrfs_endio_repair_helper;
748                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
749                         wq = fs_info->endio_raid56_workers;
750                         func = btrfs_endio_raid56_helper;
751                 } else if (end_io_wq->metadata) {
752                         wq = fs_info->endio_meta_workers;
753                         func = btrfs_endio_meta_helper;
754                 } else {
755                         wq = fs_info->endio_workers;
756                         func = btrfs_endio_helper;
757                 }
758         }
759
760         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
761         btrfs_queue_work(wq, &end_io_wq->work);
762 }
763
764 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
765                         enum btrfs_wq_endio_type metadata)
766 {
767         struct btrfs_end_io_wq *end_io_wq;
768
769         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
770         if (!end_io_wq)
771                 return -ENOMEM;
772
773         end_io_wq->private = bio->bi_private;
774         end_io_wq->end_io = bio->bi_end_io;
775         end_io_wq->info = info;
776         end_io_wq->error = 0;
777         end_io_wq->bio = bio;
778         end_io_wq->metadata = metadata;
779
780         bio->bi_private = end_io_wq;
781         bio->bi_end_io = end_workqueue_bio;
782         return 0;
783 }
784
785 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
786 {
787         unsigned long limit = min_t(unsigned long,
788                                     info->thread_pool_size,
789                                     info->fs_devices->open_devices);
790         return 256 * limit;
791 }
792
793 static void run_one_async_start(struct btrfs_work *work)
794 {
795         struct async_submit_bio *async;
796         int ret;
797
798         async = container_of(work, struct  async_submit_bio, work);
799         ret = async->submit_bio_start(async->inode, async->bio,
800                                       async->mirror_num, async->bio_flags,
801                                       async->bio_offset);
802         if (ret)
803                 async->error = ret;
804 }
805
806 static void run_one_async_done(struct btrfs_work *work)
807 {
808         struct btrfs_fs_info *fs_info;
809         struct async_submit_bio *async;
810         int limit;
811
812         async = container_of(work, struct  async_submit_bio, work);
813         fs_info = BTRFS_I(async->inode)->root->fs_info;
814
815         limit = btrfs_async_submit_limit(fs_info);
816         limit = limit * 2 / 3;
817
818         /*
819          * atomic_dec_return implies a barrier for waitqueue_active
820          */
821         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
822             waitqueue_active(&fs_info->async_submit_wait))
823                 wake_up(&fs_info->async_submit_wait);
824
825         /* If an error occurred we just want to clean up the bio and move on */
826         if (async->error) {
827                 async->bio->bi_error = async->error;
828                 bio_endio(async->bio);
829                 return;
830         }
831
832         async->submit_bio_done(async->inode, async->bio, async->mirror_num,
833                                async->bio_flags, async->bio_offset);
834 }
835
836 static void run_one_async_free(struct btrfs_work *work)
837 {
838         struct async_submit_bio *async;
839
840         async = container_of(work, struct  async_submit_bio, work);
841         kfree(async);
842 }
843
844 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
845                         struct bio *bio, int mirror_num,
846                         unsigned long bio_flags,
847                         u64 bio_offset,
848                         extent_submit_bio_hook_t *submit_bio_start,
849                         extent_submit_bio_hook_t *submit_bio_done)
850 {
851         struct async_submit_bio *async;
852
853         async = kmalloc(sizeof(*async), GFP_NOFS);
854         if (!async)
855                 return -ENOMEM;
856
857         async->inode = inode;
858         async->bio = bio;
859         async->mirror_num = mirror_num;
860         async->submit_bio_start = submit_bio_start;
861         async->submit_bio_done = submit_bio_done;
862
863         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
864                         run_one_async_done, run_one_async_free);
865
866         async->bio_flags = bio_flags;
867         async->bio_offset = bio_offset;
868
869         async->error = 0;
870
871         atomic_inc(&fs_info->nr_async_submits);
872
873         if (bio->bi_rw & REQ_SYNC)
874                 btrfs_set_work_high_priority(&async->work);
875
876         btrfs_queue_work(fs_info->workers, &async->work);
877
878         while (atomic_read(&fs_info->async_submit_draining) &&
879               atomic_read(&fs_info->nr_async_submits)) {
880                 wait_event(fs_info->async_submit_wait,
881                            (atomic_read(&fs_info->nr_async_submits) == 0));
882         }
883
884         return 0;
885 }
886
887 static int btree_csum_one_bio(struct bio *bio)
888 {
889         struct bio_vec *bvec;
890         struct btrfs_root *root;
891         int i, ret = 0;
892
893         bio_for_each_segment_all(bvec, bio, i) {
894                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
895                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
896                 if (ret)
897                         break;
898         }
899
900         return ret;
901 }
902
903 static int __btree_submit_bio_start(struct inode *inode, struct bio *bio,
904                                     int mirror_num, unsigned long bio_flags,
905                                     u64 bio_offset)
906 {
907         /*
908          * when we're called for a write, we're already in the async
909          * submission context.  Just jump into btrfs_map_bio
910          */
911         return btree_csum_one_bio(bio);
912 }
913
914 static int __btree_submit_bio_done(struct inode *inode, struct bio *bio,
915                                  int mirror_num, unsigned long bio_flags,
916                                  u64 bio_offset)
917 {
918         int ret;
919
920         /*
921          * when we're called for a write, we're already in the async
922          * submission context.  Just jump into btrfs_map_bio
923          */
924         ret = btrfs_map_bio(BTRFS_I(inode)->root, bio, mirror_num, 1);
925         if (ret) {
926                 bio->bi_error = ret;
927                 bio_endio(bio);
928         }
929         return ret;
930 }
931
932 static int check_async_write(struct inode *inode, unsigned long bio_flags)
933 {
934         if (bio_flags & EXTENT_BIO_TREE_LOG)
935                 return 0;
936 #ifdef CONFIG_X86
937         if (static_cpu_has(X86_FEATURE_XMM4_2))
938                 return 0;
939 #endif
940         return 1;
941 }
942
943 static int btree_submit_bio_hook(struct inode *inode, struct bio *bio,
944                                  int mirror_num, unsigned long bio_flags,
945                                  u64 bio_offset)
946 {
947         int async = check_async_write(inode, bio_flags);
948         int ret;
949
950         if (bio_op(bio) != REQ_OP_WRITE) {
951                 /*
952                  * called for a read, do the setup so that checksum validation
953                  * can happen in the async kernel threads
954                  */
955                 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
956                                           bio, BTRFS_WQ_ENDIO_METADATA);
957                 if (ret)
958                         goto out_w_error;
959                 ret = btrfs_map_bio(BTRFS_I(inode)->root, bio, mirror_num, 0);
960         } else if (!async) {
961                 ret = btree_csum_one_bio(bio);
962                 if (ret)
963                         goto out_w_error;
964                 ret = btrfs_map_bio(BTRFS_I(inode)->root, bio, mirror_num, 0);
965         } else {
966                 /*
967                  * kthread helpers are used to submit writes so that
968                  * checksumming can happen in parallel across all CPUs
969                  */
970                 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
971                                           inode, bio, mirror_num, 0,
972                                           bio_offset,
973                                           __btree_submit_bio_start,
974                                           __btree_submit_bio_done);
975         }
976
977         if (ret)
978                 goto out_w_error;
979         return 0;
980
981 out_w_error:
982         bio->bi_error = ret;
983         bio_endio(bio);
984         return ret;
985 }
986
987 #ifdef CONFIG_MIGRATION
988 static int btree_migratepage(struct address_space *mapping,
989                         struct page *newpage, struct page *page,
990                         enum migrate_mode mode)
991 {
992         /*
993          * we can't safely write a btree page from here,
994          * we haven't done the locking hook
995          */
996         if (PageDirty(page))
997                 return -EAGAIN;
998         /*
999          * Buffers may be managed in a filesystem specific way.
1000          * We must have no buffers or drop them.
1001          */
1002         if (page_has_private(page) &&
1003             !try_to_release_page(page, GFP_KERNEL))
1004                 return -EAGAIN;
1005         return migrate_page(mapping, newpage, page, mode);
1006 }
1007 #endif
1008
1009
1010 static int btree_writepages(struct address_space *mapping,
1011                             struct writeback_control *wbc)
1012 {
1013         struct btrfs_fs_info *fs_info;
1014         int ret;
1015
1016         if (wbc->sync_mode == WB_SYNC_NONE) {
1017
1018                 if (wbc->for_kupdate)
1019                         return 0;
1020
1021                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1022                 /* this is a bit racy, but that's ok */
1023                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1024                                              BTRFS_DIRTY_METADATA_THRESH);
1025                 if (ret < 0)
1026                         return 0;
1027         }
1028         return btree_write_cache_pages(mapping, wbc);
1029 }
1030
1031 static int btree_readpage(struct file *file, struct page *page)
1032 {
1033         struct extent_io_tree *tree;
1034         tree = &BTRFS_I(page->mapping->host)->io_tree;
1035         return extent_read_full_page(tree, page, btree_get_extent, 0);
1036 }
1037
1038 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1039 {
1040         if (PageWriteback(page) || PageDirty(page))
1041                 return 0;
1042
1043         return try_release_extent_buffer(page);
1044 }
1045
1046 static void btree_invalidatepage(struct page *page, unsigned int offset,
1047                                  unsigned int length)
1048 {
1049         struct extent_io_tree *tree;
1050         tree = &BTRFS_I(page->mapping->host)->io_tree;
1051         extent_invalidatepage(tree, page, offset);
1052         btree_releasepage(page, GFP_NOFS);
1053         if (PagePrivate(page)) {
1054                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1055                            "page private not zero on page %llu",
1056                            (unsigned long long)page_offset(page));
1057                 ClearPagePrivate(page);
1058                 set_page_private(page, 0);
1059                 put_page(page);
1060         }
1061 }
1062
1063 static int btree_set_page_dirty(struct page *page)
1064 {
1065 #ifdef DEBUG
1066         struct extent_buffer *eb;
1067
1068         BUG_ON(!PagePrivate(page));
1069         eb = (struct extent_buffer *)page->private;
1070         BUG_ON(!eb);
1071         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1072         BUG_ON(!atomic_read(&eb->refs));
1073         btrfs_assert_tree_locked(eb);
1074 #endif
1075         return __set_page_dirty_nobuffers(page);
1076 }
1077
1078 static const struct address_space_operations btree_aops = {
1079         .readpage       = btree_readpage,
1080         .writepages     = btree_writepages,
1081         .releasepage    = btree_releasepage,
1082         .invalidatepage = btree_invalidatepage,
1083 #ifdef CONFIG_MIGRATION
1084         .migratepage    = btree_migratepage,
1085 #endif
1086         .set_page_dirty = btree_set_page_dirty,
1087 };
1088
1089 void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
1090 {
1091         struct extent_buffer *buf = NULL;
1092         struct inode *btree_inode = root->fs_info->btree_inode;
1093
1094         buf = btrfs_find_create_tree_block(root, bytenr);
1095         if (IS_ERR(buf))
1096                 return;
1097         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1098                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1099         free_extent_buffer(buf);
1100 }
1101
1102 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
1103                          int mirror_num, struct extent_buffer **eb)
1104 {
1105         struct extent_buffer *buf = NULL;
1106         struct inode *btree_inode = root->fs_info->btree_inode;
1107         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1108         int ret;
1109
1110         buf = btrfs_find_create_tree_block(root, bytenr);
1111         if (IS_ERR(buf))
1112                 return 0;
1113
1114         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1115
1116         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1117                                        btree_get_extent, mirror_num);
1118         if (ret) {
1119                 free_extent_buffer(buf);
1120                 return ret;
1121         }
1122
1123         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1124                 free_extent_buffer(buf);
1125                 return -EIO;
1126         } else if (extent_buffer_uptodate(buf)) {
1127                 *eb = buf;
1128         } else {
1129                 free_extent_buffer(buf);
1130         }
1131         return 0;
1132 }
1133
1134 struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
1135                                             u64 bytenr)
1136 {
1137         return find_extent_buffer(fs_info, bytenr);
1138 }
1139
1140 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1141                                                  u64 bytenr)
1142 {
1143         if (btrfs_is_testing(root->fs_info))
1144                 return alloc_test_extent_buffer(root->fs_info, bytenr,
1145                                 root->nodesize);
1146         return alloc_extent_buffer(root->fs_info, bytenr);
1147 }
1148
1149
1150 int btrfs_write_tree_block(struct extent_buffer *buf)
1151 {
1152         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1153                                         buf->start + buf->len - 1);
1154 }
1155
1156 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1157 {
1158         return filemap_fdatawait_range(buf->pages[0]->mapping,
1159                                        buf->start, buf->start + buf->len - 1);
1160 }
1161
1162 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1163                                       u64 parent_transid)
1164 {
1165         struct extent_buffer *buf = NULL;
1166         int ret;
1167
1168         buf = btrfs_find_create_tree_block(root, bytenr);
1169         if (IS_ERR(buf))
1170                 return buf;
1171
1172         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1173         if (ret) {
1174                 free_extent_buffer(buf);
1175                 return ERR_PTR(ret);
1176         }
1177         return buf;
1178
1179 }
1180
1181 void clean_tree_block(struct btrfs_trans_handle *trans,
1182                       struct btrfs_fs_info *fs_info,
1183                       struct extent_buffer *buf)
1184 {
1185         if (btrfs_header_generation(buf) ==
1186             fs_info->running_transaction->transid) {
1187                 btrfs_assert_tree_locked(buf);
1188
1189                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1190                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1191                                              -buf->len,
1192                                              fs_info->dirty_metadata_batch);
1193                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1194                         btrfs_set_lock_blocking(buf);
1195                         clear_extent_buffer_dirty(buf);
1196                 }
1197         }
1198 }
1199
1200 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1201 {
1202         struct btrfs_subvolume_writers *writers;
1203         int ret;
1204
1205         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1206         if (!writers)
1207                 return ERR_PTR(-ENOMEM);
1208
1209         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1210         if (ret < 0) {
1211                 kfree(writers);
1212                 return ERR_PTR(ret);
1213         }
1214
1215         init_waitqueue_head(&writers->wait);
1216         return writers;
1217 }
1218
1219 static void
1220 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1221 {
1222         percpu_counter_destroy(&writers->counter);
1223         kfree(writers);
1224 }
1225
1226 static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
1227                          struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1228                          u64 objectid)
1229 {
1230         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1231         root->node = NULL;
1232         root->commit_root = NULL;
1233         root->sectorsize = sectorsize;
1234         root->nodesize = nodesize;
1235         root->stripesize = stripesize;
1236         root->state = 0;
1237         root->orphan_cleanup_state = 0;
1238
1239         root->objectid = objectid;
1240         root->last_trans = 0;
1241         root->highest_objectid = 0;
1242         root->nr_delalloc_inodes = 0;
1243         root->nr_ordered_extents = 0;
1244         root->name = NULL;
1245         root->inode_tree = RB_ROOT;
1246         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1247         root->block_rsv = NULL;
1248         root->orphan_block_rsv = NULL;
1249
1250         INIT_LIST_HEAD(&root->dirty_list);
1251         INIT_LIST_HEAD(&root->root_list);
1252         INIT_LIST_HEAD(&root->delalloc_inodes);
1253         INIT_LIST_HEAD(&root->delalloc_root);
1254         INIT_LIST_HEAD(&root->ordered_extents);
1255         INIT_LIST_HEAD(&root->ordered_root);
1256         INIT_LIST_HEAD(&root->logged_list[0]);
1257         INIT_LIST_HEAD(&root->logged_list[1]);
1258         spin_lock_init(&root->orphan_lock);
1259         spin_lock_init(&root->inode_lock);
1260         spin_lock_init(&root->delalloc_lock);
1261         spin_lock_init(&root->ordered_extent_lock);
1262         spin_lock_init(&root->accounting_lock);
1263         spin_lock_init(&root->log_extents_lock[0]);
1264         spin_lock_init(&root->log_extents_lock[1]);
1265         mutex_init(&root->objectid_mutex);
1266         mutex_init(&root->log_mutex);
1267         mutex_init(&root->ordered_extent_mutex);
1268         mutex_init(&root->delalloc_mutex);
1269         init_waitqueue_head(&root->log_writer_wait);
1270         init_waitqueue_head(&root->log_commit_wait[0]);
1271         init_waitqueue_head(&root->log_commit_wait[1]);
1272         INIT_LIST_HEAD(&root->log_ctxs[0]);
1273         INIT_LIST_HEAD(&root->log_ctxs[1]);
1274         atomic_set(&root->log_commit[0], 0);
1275         atomic_set(&root->log_commit[1], 0);
1276         atomic_set(&root->log_writers, 0);
1277         atomic_set(&root->log_batch, 0);
1278         atomic_set(&root->orphan_inodes, 0);
1279         atomic_set(&root->refs, 1);
1280         atomic_set(&root->will_be_snapshoted, 0);
1281         atomic_set(&root->qgroup_meta_rsv, 0);
1282         root->log_transid = 0;
1283         root->log_transid_committed = -1;
1284         root->last_log_commit = 0;
1285         if (!dummy)
1286                 extent_io_tree_init(&root->dirty_log_pages,
1287                                      fs_info->btree_inode->i_mapping);
1288
1289         memset(&root->root_key, 0, sizeof(root->root_key));
1290         memset(&root->root_item, 0, sizeof(root->root_item));
1291         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1292         if (!dummy)
1293                 root->defrag_trans_start = fs_info->generation;
1294         else
1295                 root->defrag_trans_start = 0;
1296         root->root_key.objectid = objectid;
1297         root->anon_dev = 0;
1298
1299         spin_lock_init(&root->root_item_lock);
1300 }
1301
1302 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1303                 gfp_t flags)
1304 {
1305         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1306         if (root)
1307                 root->fs_info = fs_info;
1308         return root;
1309 }
1310
1311 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1312 /* Should only be used by the testing infrastructure */
1313 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info,
1314                                           u32 sectorsize, u32 nodesize)
1315 {
1316         struct btrfs_root *root;
1317
1318         if (!fs_info)
1319                 return ERR_PTR(-EINVAL);
1320
1321         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1322         if (!root)
1323                 return ERR_PTR(-ENOMEM);
1324         /* We don't use the stripesize in selftest, set it as sectorsize */
1325         __setup_root(nodesize, sectorsize, sectorsize, root, fs_info,
1326                         BTRFS_ROOT_TREE_OBJECTID);
1327         root->alloc_bytenr = 0;
1328
1329         return root;
1330 }
1331 #endif
1332
1333 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1334                                      struct btrfs_fs_info *fs_info,
1335                                      u64 objectid)
1336 {
1337         struct extent_buffer *leaf;
1338         struct btrfs_root *tree_root = fs_info->tree_root;
1339         struct btrfs_root *root;
1340         struct btrfs_key key;
1341         int ret = 0;
1342         uuid_le uuid;
1343
1344         root = btrfs_alloc_root(fs_info, GFP_KERNEL);
1345         if (!root)
1346                 return ERR_PTR(-ENOMEM);
1347
1348         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1349                 tree_root->stripesize, root, fs_info, objectid);
1350         root->root_key.objectid = objectid;
1351         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1352         root->root_key.offset = 0;
1353
1354         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1355         if (IS_ERR(leaf)) {
1356                 ret = PTR_ERR(leaf);
1357                 leaf = NULL;
1358                 goto fail;
1359         }
1360
1361         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1362         btrfs_set_header_bytenr(leaf, leaf->start);
1363         btrfs_set_header_generation(leaf, trans->transid);
1364         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1365         btrfs_set_header_owner(leaf, objectid);
1366         root->node = leaf;
1367
1368         write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(),
1369                             BTRFS_FSID_SIZE);
1370         write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1371                             btrfs_header_chunk_tree_uuid(leaf),
1372                             BTRFS_UUID_SIZE);
1373         btrfs_mark_buffer_dirty(leaf);
1374
1375         root->commit_root = btrfs_root_node(root);
1376         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1377
1378         root->root_item.flags = 0;
1379         root->root_item.byte_limit = 0;
1380         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1381         btrfs_set_root_generation(&root->root_item, trans->transid);
1382         btrfs_set_root_level(&root->root_item, 0);
1383         btrfs_set_root_refs(&root->root_item, 1);
1384         btrfs_set_root_used(&root->root_item, leaf->len);
1385         btrfs_set_root_last_snapshot(&root->root_item, 0);
1386         btrfs_set_root_dirid(&root->root_item, 0);
1387         uuid_le_gen(&uuid);
1388         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1389         root->root_item.drop_level = 0;
1390
1391         key.objectid = objectid;
1392         key.type = BTRFS_ROOT_ITEM_KEY;
1393         key.offset = 0;
1394         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1395         if (ret)
1396                 goto fail;
1397
1398         btrfs_tree_unlock(leaf);
1399
1400         return root;
1401
1402 fail:
1403         if (leaf) {
1404                 btrfs_tree_unlock(leaf);
1405                 free_extent_buffer(root->commit_root);
1406                 free_extent_buffer(leaf);
1407         }
1408         kfree(root);
1409
1410         return ERR_PTR(ret);
1411 }
1412
1413 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1414                                          struct btrfs_fs_info *fs_info)
1415 {
1416         struct btrfs_root *root;
1417         struct btrfs_root *tree_root = fs_info->tree_root;
1418         struct extent_buffer *leaf;
1419
1420         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1421         if (!root)
1422                 return ERR_PTR(-ENOMEM);
1423
1424         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1425                      tree_root->stripesize, root, fs_info,
1426                      BTRFS_TREE_LOG_OBJECTID);
1427
1428         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1429         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1430         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1431
1432         /*
1433          * DON'T set REF_COWS for log trees
1434          *
1435          * log trees do not get reference counted because they go away
1436          * before a real commit is actually done.  They do store pointers
1437          * to file data extents, and those reference counts still get
1438          * updated (along with back refs to the log tree).
1439          */
1440
1441         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1442                         NULL, 0, 0, 0);
1443         if (IS_ERR(leaf)) {
1444                 kfree(root);
1445                 return ERR_CAST(leaf);
1446         }
1447
1448         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1449         btrfs_set_header_bytenr(leaf, leaf->start);
1450         btrfs_set_header_generation(leaf, trans->transid);
1451         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1452         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1453         root->node = leaf;
1454
1455         write_extent_buffer(root->node, root->fs_info->fsid,
1456                             btrfs_header_fsid(), BTRFS_FSID_SIZE);
1457         btrfs_mark_buffer_dirty(root->node);
1458         btrfs_tree_unlock(root->node);
1459         return root;
1460 }
1461
1462 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1463                              struct btrfs_fs_info *fs_info)
1464 {
1465         struct btrfs_root *log_root;
1466
1467         log_root = alloc_log_tree(trans, fs_info);
1468         if (IS_ERR(log_root))
1469                 return PTR_ERR(log_root);
1470         WARN_ON(fs_info->log_root_tree);
1471         fs_info->log_root_tree = log_root;
1472         return 0;
1473 }
1474
1475 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1476                        struct btrfs_root *root)
1477 {
1478         struct btrfs_root *log_root;
1479         struct btrfs_inode_item *inode_item;
1480
1481         log_root = alloc_log_tree(trans, root->fs_info);
1482         if (IS_ERR(log_root))
1483                 return PTR_ERR(log_root);
1484
1485         log_root->last_trans = trans->transid;
1486         log_root->root_key.offset = root->root_key.objectid;
1487
1488         inode_item = &log_root->root_item.inode;
1489         btrfs_set_stack_inode_generation(inode_item, 1);
1490         btrfs_set_stack_inode_size(inode_item, 3);
1491         btrfs_set_stack_inode_nlink(inode_item, 1);
1492         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
1493         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1494
1495         btrfs_set_root_node(&log_root->root_item, log_root->node);
1496
1497         WARN_ON(root->log_root);
1498         root->log_root = log_root;
1499         root->log_transid = 0;
1500         root->log_transid_committed = -1;
1501         root->last_log_commit = 0;
1502         return 0;
1503 }
1504
1505 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1506                                                struct btrfs_key *key)
1507 {
1508         struct btrfs_root *root;
1509         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1510         struct btrfs_path *path;
1511         u64 generation;
1512         int ret;
1513
1514         path = btrfs_alloc_path();
1515         if (!path)
1516                 return ERR_PTR(-ENOMEM);
1517
1518         root = btrfs_alloc_root(fs_info, GFP_NOFS);
1519         if (!root) {
1520                 ret = -ENOMEM;
1521                 goto alloc_fail;
1522         }
1523
1524         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1525                 tree_root->stripesize, root, fs_info, key->objectid);
1526
1527         ret = btrfs_find_root(tree_root, key, path,
1528                               &root->root_item, &root->root_key);
1529         if (ret) {
1530                 if (ret > 0)
1531                         ret = -ENOENT;
1532                 goto find_fail;
1533         }
1534
1535         generation = btrfs_root_generation(&root->root_item);
1536         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1537                                      generation);
1538         if (IS_ERR(root->node)) {
1539                 ret = PTR_ERR(root->node);
1540                 goto find_fail;
1541         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1542                 ret = -EIO;
1543                 free_extent_buffer(root->node);
1544                 goto find_fail;
1545         }
1546         root->commit_root = btrfs_root_node(root);
1547 out:
1548         btrfs_free_path(path);
1549         return root;
1550
1551 find_fail:
1552         kfree(root);
1553 alloc_fail:
1554         root = ERR_PTR(ret);
1555         goto out;
1556 }
1557
1558 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1559                                       struct btrfs_key *location)
1560 {
1561         struct btrfs_root *root;
1562
1563         root = btrfs_read_tree_root(tree_root, location);
1564         if (IS_ERR(root))
1565                 return root;
1566
1567         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1568                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1569                 btrfs_check_and_init_root_item(&root->root_item);
1570         }
1571
1572         return root;
1573 }
1574
1575 int btrfs_init_fs_root(struct btrfs_root *root)
1576 {
1577         int ret;
1578         struct btrfs_subvolume_writers *writers;
1579
1580         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1581         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1582                                         GFP_NOFS);
1583         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1584                 ret = -ENOMEM;
1585                 goto fail;
1586         }
1587
1588         writers = btrfs_alloc_subvolume_writers();
1589         if (IS_ERR(writers)) {
1590                 ret = PTR_ERR(writers);
1591                 goto fail;
1592         }
1593         root->subv_writers = writers;
1594
1595         btrfs_init_free_ino_ctl(root);
1596         spin_lock_init(&root->ino_cache_lock);
1597         init_waitqueue_head(&root->ino_cache_wait);
1598
1599         ret = get_anon_bdev(&root->anon_dev);
1600         if (ret)
1601                 goto fail;
1602
1603         mutex_lock(&root->objectid_mutex);
1604         ret = btrfs_find_highest_objectid(root,
1605                                         &root->highest_objectid);
1606         if (ret) {
1607                 mutex_unlock(&root->objectid_mutex);
1608                 goto fail;
1609         }
1610
1611         ASSERT(root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
1612
1613         mutex_unlock(&root->objectid_mutex);
1614
1615         return 0;
1616 fail:
1617         /* the caller is responsible to call free_fs_root */
1618         return ret;
1619 }
1620
1621 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1622                                                u64 root_id)
1623 {
1624         struct btrfs_root *root;
1625
1626         spin_lock(&fs_info->fs_roots_radix_lock);
1627         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1628                                  (unsigned long)root_id);
1629         spin_unlock(&fs_info->fs_roots_radix_lock);
1630         return root;
1631 }
1632
1633 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1634                          struct btrfs_root *root)
1635 {
1636         int ret;
1637
1638         ret = radix_tree_preload(GFP_NOFS);
1639         if (ret)
1640                 return ret;
1641
1642         spin_lock(&fs_info->fs_roots_radix_lock);
1643         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1644                                 (unsigned long)root->root_key.objectid,
1645                                 root);
1646         if (ret == 0)
1647                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1648         spin_unlock(&fs_info->fs_roots_radix_lock);
1649         radix_tree_preload_end();
1650
1651         return ret;
1652 }
1653
1654 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1655                                      struct btrfs_key *location,
1656                                      bool check_ref)
1657 {
1658         struct btrfs_root *root;
1659         struct btrfs_path *path;
1660         struct btrfs_key key;
1661         int ret;
1662
1663         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1664                 return fs_info->tree_root;
1665         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1666                 return fs_info->extent_root;
1667         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1668                 return fs_info->chunk_root;
1669         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1670                 return fs_info->dev_root;
1671         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1672                 return fs_info->csum_root;
1673         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1674                 return fs_info->quota_root ? fs_info->quota_root :
1675                                              ERR_PTR(-ENOENT);
1676         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1677                 return fs_info->uuid_root ? fs_info->uuid_root :
1678                                             ERR_PTR(-ENOENT);
1679         if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1680                 return fs_info->free_space_root ? fs_info->free_space_root :
1681                                                   ERR_PTR(-ENOENT);
1682 again:
1683         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1684         if (root) {
1685                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1686                         return ERR_PTR(-ENOENT);
1687                 return root;
1688         }
1689
1690         root = btrfs_read_fs_root(fs_info->tree_root, location);
1691         if (IS_ERR(root))
1692                 return root;
1693
1694         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1695                 ret = -ENOENT;
1696                 goto fail;
1697         }
1698
1699         ret = btrfs_init_fs_root(root);
1700         if (ret)
1701                 goto fail;
1702
1703         path = btrfs_alloc_path();
1704         if (!path) {
1705                 ret = -ENOMEM;
1706                 goto fail;
1707         }
1708         key.objectid = BTRFS_ORPHAN_OBJECTID;
1709         key.type = BTRFS_ORPHAN_ITEM_KEY;
1710         key.offset = location->objectid;
1711
1712         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1713         btrfs_free_path(path);
1714         if (ret < 0)
1715                 goto fail;
1716         if (ret == 0)
1717                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1718
1719         ret = btrfs_insert_fs_root(fs_info, root);
1720         if (ret) {
1721                 if (ret == -EEXIST) {
1722                         free_fs_root(root);
1723                         goto again;
1724                 }
1725                 goto fail;
1726         }
1727         return root;
1728 fail:
1729         free_fs_root(root);
1730         return ERR_PTR(ret);
1731 }
1732
1733 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1734 {
1735         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1736         int ret = 0;
1737         struct btrfs_device *device;
1738         struct backing_dev_info *bdi;
1739
1740         rcu_read_lock();
1741         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1742                 if (!device->bdev)
1743                         continue;
1744                 bdi = blk_get_backing_dev_info(device->bdev);
1745                 if (bdi_congested(bdi, bdi_bits)) {
1746                         ret = 1;
1747                         break;
1748                 }
1749         }
1750         rcu_read_unlock();
1751         return ret;
1752 }
1753
1754 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1755 {
1756         int err;
1757
1758         err = bdi_setup_and_register(bdi, "btrfs");
1759         if (err)
1760                 return err;
1761
1762         bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
1763         bdi->congested_fn       = btrfs_congested_fn;
1764         bdi->congested_data     = info;
1765         bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
1766         return 0;
1767 }
1768
1769 /*
1770  * called by the kthread helper functions to finally call the bio end_io
1771  * functions.  This is where read checksum verification actually happens
1772  */
1773 static void end_workqueue_fn(struct btrfs_work *work)
1774 {
1775         struct bio *bio;
1776         struct btrfs_end_io_wq *end_io_wq;
1777
1778         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1779         bio = end_io_wq->bio;
1780
1781         bio->bi_error = end_io_wq->error;
1782         bio->bi_private = end_io_wq->private;
1783         bio->bi_end_io = end_io_wq->end_io;
1784         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1785         bio_endio(bio);
1786 }
1787
1788 static int cleaner_kthread(void *arg)
1789 {
1790         struct btrfs_root *root = arg;
1791         int again;
1792         struct btrfs_trans_handle *trans;
1793
1794         do {
1795                 again = 0;
1796
1797                 /* Make the cleaner go to sleep early. */
1798                 if (btrfs_need_cleaner_sleep(root))
1799                         goto sleep;
1800
1801                 /*
1802                  * Do not do anything if we might cause open_ctree() to block
1803                  * before we have finished mounting the filesystem.
1804                  */
1805                 if (!root->fs_info->open)
1806                         goto sleep;
1807
1808                 if (!mutex_trylock(&root->fs_info->cleaner_mutex))
1809                         goto sleep;
1810
1811                 /*
1812                  * Avoid the problem that we change the status of the fs
1813                  * during the above check and trylock.
1814                  */
1815                 if (btrfs_need_cleaner_sleep(root)) {
1816                         mutex_unlock(&root->fs_info->cleaner_mutex);
1817                         goto sleep;
1818                 }
1819
1820                 mutex_lock(&root->fs_info->cleaner_delayed_iput_mutex);
1821                 btrfs_run_delayed_iputs(root);
1822                 mutex_unlock(&root->fs_info->cleaner_delayed_iput_mutex);
1823
1824                 again = btrfs_clean_one_deleted_snapshot(root);
1825                 mutex_unlock(&root->fs_info->cleaner_mutex);
1826
1827                 /*
1828                  * The defragger has dealt with the R/O remount and umount,
1829                  * needn't do anything special here.
1830                  */
1831                 btrfs_run_defrag_inodes(root->fs_info);
1832
1833                 /*
1834                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1835                  * with relocation (btrfs_relocate_chunk) and relocation
1836                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1837                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1838                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1839                  * unused block groups.
1840                  */
1841                 btrfs_delete_unused_bgs(root->fs_info);
1842 sleep:
1843                 if (!again) {
1844                         set_current_state(TASK_INTERRUPTIBLE);
1845                         if (!kthread_should_stop())
1846                                 schedule();
1847                         __set_current_state(TASK_RUNNING);
1848                 }
1849         } while (!kthread_should_stop());
1850
1851         /*
1852          * Transaction kthread is stopped before us and wakes us up.
1853          * However we might have started a new transaction and COWed some
1854          * tree blocks when deleting unused block groups for example. So
1855          * make sure we commit the transaction we started to have a clean
1856          * shutdown when evicting the btree inode - if it has dirty pages
1857          * when we do the final iput() on it, eviction will trigger a
1858          * writeback for it which will fail with null pointer dereferences
1859          * since work queues and other resources were already released and
1860          * destroyed by the time the iput/eviction/writeback is made.
1861          */
1862         trans = btrfs_attach_transaction(root);
1863         if (IS_ERR(trans)) {
1864                 if (PTR_ERR(trans) != -ENOENT)
1865                         btrfs_err(root->fs_info,
1866                                   "cleaner transaction attach returned %ld",
1867                                   PTR_ERR(trans));
1868         } else {
1869                 int ret;
1870
1871                 ret = btrfs_commit_transaction(trans, root);
1872                 if (ret)
1873                         btrfs_err(root->fs_info,
1874                                   "cleaner open transaction commit returned %d",
1875                                   ret);
1876         }
1877
1878         return 0;
1879 }
1880
1881 static int transaction_kthread(void *arg)
1882 {
1883         struct btrfs_root *root = arg;
1884         struct btrfs_trans_handle *trans;
1885         struct btrfs_transaction *cur;
1886         u64 transid;
1887         unsigned long now;
1888         unsigned long delay;
1889         bool cannot_commit;
1890
1891         do {
1892                 cannot_commit = false;
1893                 delay = HZ * root->fs_info->commit_interval;
1894                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1895
1896                 spin_lock(&root->fs_info->trans_lock);
1897                 cur = root->fs_info->running_transaction;
1898                 if (!cur) {
1899                         spin_unlock(&root->fs_info->trans_lock);
1900                         goto sleep;
1901                 }
1902
1903                 now = get_seconds();
1904                 if (cur->state < TRANS_STATE_BLOCKED &&
1905                     (now < cur->start_time ||
1906                      now - cur->start_time < root->fs_info->commit_interval)) {
1907                         spin_unlock(&root->fs_info->trans_lock);
1908                         delay = HZ * 5;
1909                         goto sleep;
1910                 }
1911                 transid = cur->transid;
1912                 spin_unlock(&root->fs_info->trans_lock);
1913
1914                 /* If the file system is aborted, this will always fail. */
1915                 trans = btrfs_attach_transaction(root);
1916                 if (IS_ERR(trans)) {
1917                         if (PTR_ERR(trans) != -ENOENT)
1918                                 cannot_commit = true;
1919                         goto sleep;
1920                 }
1921                 if (transid == trans->transid) {
1922                         btrfs_commit_transaction(trans, root);
1923                 } else {
1924                         btrfs_end_transaction(trans, root);
1925                 }
1926 sleep:
1927                 wake_up_process(root->fs_info->cleaner_kthread);
1928                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1929
1930                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1931                                       &root->fs_info->fs_state)))
1932                         btrfs_cleanup_transaction(root);
1933                 set_current_state(TASK_INTERRUPTIBLE);
1934                 if (!kthread_should_stop() &&
1935                                 (!btrfs_transaction_blocked(root->fs_info) ||
1936                                  cannot_commit))
1937                         schedule_timeout(delay);
1938                 __set_current_state(TASK_RUNNING);
1939         } while (!kthread_should_stop());
1940         return 0;
1941 }
1942
1943 /*
1944  * this will find the highest generation in the array of
1945  * root backups.  The index of the highest array is returned,
1946  * or -1 if we can't find anything.
1947  *
1948  * We check to make sure the array is valid by comparing the
1949  * generation of the latest  root in the array with the generation
1950  * in the super block.  If they don't match we pitch it.
1951  */
1952 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1953 {
1954         u64 cur;
1955         int newest_index = -1;
1956         struct btrfs_root_backup *root_backup;
1957         int i;
1958
1959         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1960                 root_backup = info->super_copy->super_roots + i;
1961                 cur = btrfs_backup_tree_root_gen(root_backup);
1962                 if (cur == newest_gen)
1963                         newest_index = i;
1964         }
1965
1966         /* check to see if we actually wrapped around */
1967         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1968                 root_backup = info->super_copy->super_roots;
1969                 cur = btrfs_backup_tree_root_gen(root_backup);
1970                 if (cur == newest_gen)
1971                         newest_index = 0;
1972         }
1973         return newest_index;
1974 }
1975
1976
1977 /*
1978  * find the oldest backup so we know where to store new entries
1979  * in the backup array.  This will set the backup_root_index
1980  * field in the fs_info struct
1981  */
1982 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1983                                      u64 newest_gen)
1984 {
1985         int newest_index = -1;
1986
1987         newest_index = find_newest_super_backup(info, newest_gen);
1988         /* if there was garbage in there, just move along */
1989         if (newest_index == -1) {
1990                 info->backup_root_index = 0;
1991         } else {
1992                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1993         }
1994 }
1995
1996 /*
1997  * copy all the root pointers into the super backup array.
1998  * this will bump the backup pointer by one when it is
1999  * done
2000  */
2001 static void backup_super_roots(struct btrfs_fs_info *info)
2002 {
2003         int next_backup;
2004         struct btrfs_root_backup *root_backup;
2005         int last_backup;
2006
2007         next_backup = info->backup_root_index;
2008         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
2009                 BTRFS_NUM_BACKUP_ROOTS;
2010
2011         /*
2012          * just overwrite the last backup if we're at the same generation
2013          * this happens only at umount
2014          */
2015         root_backup = info->super_for_commit->super_roots + last_backup;
2016         if (btrfs_backup_tree_root_gen(root_backup) ==
2017             btrfs_header_generation(info->tree_root->node))
2018                 next_backup = last_backup;
2019
2020         root_backup = info->super_for_commit->super_roots + next_backup;
2021
2022         /*
2023          * make sure all of our padding and empty slots get zero filled
2024          * regardless of which ones we use today
2025          */
2026         memset(root_backup, 0, sizeof(*root_backup));
2027
2028         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2029
2030         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2031         btrfs_set_backup_tree_root_gen(root_backup,
2032                                btrfs_header_generation(info->tree_root->node));
2033
2034         btrfs_set_backup_tree_root_level(root_backup,
2035                                btrfs_header_level(info->tree_root->node));
2036
2037         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2038         btrfs_set_backup_chunk_root_gen(root_backup,
2039                                btrfs_header_generation(info->chunk_root->node));
2040         btrfs_set_backup_chunk_root_level(root_backup,
2041                                btrfs_header_level(info->chunk_root->node));
2042
2043         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2044         btrfs_set_backup_extent_root_gen(root_backup,
2045                                btrfs_header_generation(info->extent_root->node));
2046         btrfs_set_backup_extent_root_level(root_backup,
2047                                btrfs_header_level(info->extent_root->node));
2048
2049         /*
2050          * we might commit during log recovery, which happens before we set
2051          * the fs_root.  Make sure it is valid before we fill it in.
2052          */
2053         if (info->fs_root && info->fs_root->node) {
2054                 btrfs_set_backup_fs_root(root_backup,
2055                                          info->fs_root->node->start);
2056                 btrfs_set_backup_fs_root_gen(root_backup,
2057                                btrfs_header_generation(info->fs_root->node));
2058                 btrfs_set_backup_fs_root_level(root_backup,
2059                                btrfs_header_level(info->fs_root->node));
2060         }
2061
2062         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2063         btrfs_set_backup_dev_root_gen(root_backup,
2064                                btrfs_header_generation(info->dev_root->node));
2065         btrfs_set_backup_dev_root_level(root_backup,
2066                                        btrfs_header_level(info->dev_root->node));
2067
2068         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2069         btrfs_set_backup_csum_root_gen(root_backup,
2070                                btrfs_header_generation(info->csum_root->node));
2071         btrfs_set_backup_csum_root_level(root_backup,
2072                                btrfs_header_level(info->csum_root->node));
2073
2074         btrfs_set_backup_total_bytes(root_backup,
2075                              btrfs_super_total_bytes(info->super_copy));
2076         btrfs_set_backup_bytes_used(root_backup,
2077                              btrfs_super_bytes_used(info->super_copy));
2078         btrfs_set_backup_num_devices(root_backup,
2079                              btrfs_super_num_devices(info->super_copy));
2080
2081         /*
2082          * if we don't copy this out to the super_copy, it won't get remembered
2083          * for the next commit
2084          */
2085         memcpy(&info->super_copy->super_roots,
2086                &info->super_for_commit->super_roots,
2087                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2088 }
2089
2090 /*
2091  * this copies info out of the root backup array and back into
2092  * the in-memory super block.  It is meant to help iterate through
2093  * the array, so you send it the number of backups you've already
2094  * tried and the last backup index you used.
2095  *
2096  * this returns -1 when it has tried all the backups
2097  */
2098 static noinline int next_root_backup(struct btrfs_fs_info *info,
2099                                      struct btrfs_super_block *super,
2100                                      int *num_backups_tried, int *backup_index)
2101 {
2102         struct btrfs_root_backup *root_backup;
2103         int newest = *backup_index;
2104
2105         if (*num_backups_tried == 0) {
2106                 u64 gen = btrfs_super_generation(super);
2107
2108                 newest = find_newest_super_backup(info, gen);
2109                 if (newest == -1)
2110                         return -1;
2111
2112                 *backup_index = newest;
2113                 *num_backups_tried = 1;
2114         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2115                 /* we've tried all the backups, all done */
2116                 return -1;
2117         } else {
2118                 /* jump to the next oldest backup */
2119                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2120                         BTRFS_NUM_BACKUP_ROOTS;
2121                 *backup_index = newest;
2122                 *num_backups_tried += 1;
2123         }
2124         root_backup = super->super_roots + newest;
2125
2126         btrfs_set_super_generation(super,
2127                                    btrfs_backup_tree_root_gen(root_backup));
2128         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2129         btrfs_set_super_root_level(super,
2130                                    btrfs_backup_tree_root_level(root_backup));
2131         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2132
2133         /*
2134          * fixme: the total bytes and num_devices need to match or we should
2135          * need a fsck
2136          */
2137         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2138         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2139         return 0;
2140 }
2141
2142 /* helper to cleanup workers */
2143 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2144 {
2145         btrfs_destroy_workqueue(fs_info->fixup_workers);
2146         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2147         btrfs_destroy_workqueue(fs_info->workers);
2148         btrfs_destroy_workqueue(fs_info->endio_workers);
2149         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2150         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2151         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2152         btrfs_destroy_workqueue(fs_info->rmw_workers);
2153         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2154         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2155         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2156         btrfs_destroy_workqueue(fs_info->submit_workers);
2157         btrfs_destroy_workqueue(fs_info->delayed_workers);
2158         btrfs_destroy_workqueue(fs_info->caching_workers);
2159         btrfs_destroy_workqueue(fs_info->readahead_workers);
2160         btrfs_destroy_workqueue(fs_info->flush_workers);
2161         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2162         btrfs_destroy_workqueue(fs_info->extent_workers);
2163 }
2164
2165 static void free_root_extent_buffers(struct btrfs_root *root)
2166 {
2167         if (root) {
2168                 free_extent_buffer(root->node);
2169                 free_extent_buffer(root->commit_root);
2170                 root->node = NULL;
2171                 root->commit_root = NULL;
2172         }
2173 }
2174
2175 /* helper to cleanup tree roots */
2176 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2177 {
2178         free_root_extent_buffers(info->tree_root);
2179
2180         free_root_extent_buffers(info->dev_root);
2181         free_root_extent_buffers(info->extent_root);
2182         free_root_extent_buffers(info->csum_root);
2183         free_root_extent_buffers(info->quota_root);
2184         free_root_extent_buffers(info->uuid_root);
2185         if (chunk_root)
2186                 free_root_extent_buffers(info->chunk_root);
2187         free_root_extent_buffers(info->free_space_root);
2188 }
2189
2190 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2191 {
2192         int ret;
2193         struct btrfs_root *gang[8];
2194         int i;
2195
2196         while (!list_empty(&fs_info->dead_roots)) {
2197                 gang[0] = list_entry(fs_info->dead_roots.next,
2198                                      struct btrfs_root, root_list);
2199                 list_del(&gang[0]->root_list);
2200
2201                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2202                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2203                 } else {
2204                         free_extent_buffer(gang[0]->node);
2205                         free_extent_buffer(gang[0]->commit_root);
2206                         btrfs_put_fs_root(gang[0]);
2207                 }
2208         }
2209
2210         while (1) {
2211                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2212                                              (void **)gang, 0,
2213                                              ARRAY_SIZE(gang));
2214                 if (!ret)
2215                         break;
2216                 for (i = 0; i < ret; i++)
2217                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2218         }
2219
2220         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2221                 btrfs_free_log_root_tree(NULL, fs_info);
2222                 btrfs_destroy_pinned_extent(fs_info->tree_root,
2223                                             fs_info->pinned_extents);
2224         }
2225 }
2226
2227 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2228 {
2229         mutex_init(&fs_info->scrub_lock);
2230         atomic_set(&fs_info->scrubs_running, 0);
2231         atomic_set(&fs_info->scrub_pause_req, 0);
2232         atomic_set(&fs_info->scrubs_paused, 0);
2233         atomic_set(&fs_info->scrub_cancel_req, 0);
2234         init_waitqueue_head(&fs_info->scrub_pause_wait);
2235         fs_info->scrub_workers_refcnt = 0;
2236 }
2237
2238 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2239 {
2240         spin_lock_init(&fs_info->balance_lock);
2241         mutex_init(&fs_info->balance_mutex);
2242         atomic_set(&fs_info->balance_running, 0);
2243         atomic_set(&fs_info->balance_pause_req, 0);
2244         atomic_set(&fs_info->balance_cancel_req, 0);
2245         fs_info->balance_ctl = NULL;
2246         init_waitqueue_head(&fs_info->balance_wait_q);
2247 }
2248
2249 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info,
2250                                    struct btrfs_root *tree_root)
2251 {
2252         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2253         set_nlink(fs_info->btree_inode, 1);
2254         /*
2255          * we set the i_size on the btree inode to the max possible int.
2256          * the real end of the address space is determined by all of
2257          * the devices in the system
2258          */
2259         fs_info->btree_inode->i_size = OFFSET_MAX;
2260         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2261
2262         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2263         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2264                              fs_info->btree_inode->i_mapping);
2265         BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2266         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2267
2268         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2269
2270         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2271         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2272                sizeof(struct btrfs_key));
2273         set_bit(BTRFS_INODE_DUMMY,
2274                 &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2275         btrfs_insert_inode_hash(fs_info->btree_inode);
2276 }
2277
2278 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2279 {
2280         fs_info->dev_replace.lock_owner = 0;
2281         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2282         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2283         rwlock_init(&fs_info->dev_replace.lock);
2284         atomic_set(&fs_info->dev_replace.read_locks, 0);
2285         atomic_set(&fs_info->dev_replace.blocking_readers, 0);
2286         init_waitqueue_head(&fs_info->replace_wait);
2287         init_waitqueue_head(&fs_info->dev_replace.read_lock_wq);
2288 }
2289
2290 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2291 {
2292         spin_lock_init(&fs_info->qgroup_lock);
2293         mutex_init(&fs_info->qgroup_ioctl_lock);
2294         fs_info->qgroup_tree = RB_ROOT;
2295         fs_info->qgroup_op_tree = RB_ROOT;
2296         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2297         fs_info->qgroup_seq = 1;
2298         fs_info->quota_enabled = 0;
2299         fs_info->pending_quota_state = 0;
2300         fs_info->qgroup_ulist = NULL;
2301         mutex_init(&fs_info->qgroup_rescan_lock);
2302 }
2303
2304 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2305                 struct btrfs_fs_devices *fs_devices)
2306 {
2307         int max_active = fs_info->thread_pool_size;
2308         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2309
2310         fs_info->workers =
2311                 btrfs_alloc_workqueue(fs_info, "worker",
2312                                       flags | WQ_HIGHPRI, max_active, 16);
2313
2314         fs_info->delalloc_workers =
2315                 btrfs_alloc_workqueue(fs_info, "delalloc",
2316                                       flags, max_active, 2);
2317
2318         fs_info->flush_workers =
2319                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2320                                       flags, max_active, 0);
2321
2322         fs_info->caching_workers =
2323                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2324
2325         /*
2326          * a higher idle thresh on the submit workers makes it much more
2327          * likely that bios will be send down in a sane order to the
2328          * devices
2329          */
2330         fs_info->submit_workers =
2331                 btrfs_alloc_workqueue(fs_info, "submit", flags,
2332                                       min_t(u64, fs_devices->num_devices,
2333                                             max_active), 64);
2334
2335         fs_info->fixup_workers =
2336                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2337
2338         /*
2339          * endios are largely parallel and should have a very
2340          * low idle thresh
2341          */
2342         fs_info->endio_workers =
2343                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2344         fs_info->endio_meta_workers =
2345                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2346                                       max_active, 4);
2347         fs_info->endio_meta_write_workers =
2348                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2349                                       max_active, 2);
2350         fs_info->endio_raid56_workers =
2351                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2352                                       max_active, 4);
2353         fs_info->endio_repair_workers =
2354                 btrfs_alloc_workqueue(fs_info, "endio-repair", flags, 1, 0);
2355         fs_info->rmw_workers =
2356                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2357         fs_info->endio_write_workers =
2358                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2359                                       max_active, 2);
2360         fs_info->endio_freespace_worker =
2361                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2362                                       max_active, 0);
2363         fs_info->delayed_workers =
2364                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2365                                       max_active, 0);
2366         fs_info->readahead_workers =
2367                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2368                                       max_active, 2);
2369         fs_info->qgroup_rescan_workers =
2370                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2371         fs_info->extent_workers =
2372                 btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
2373                                       min_t(u64, fs_devices->num_devices,
2374                                             max_active), 8);
2375
2376         if (!(fs_info->workers && fs_info->delalloc_workers &&
2377               fs_info->submit_workers && fs_info->flush_workers &&
2378               fs_info->endio_workers && fs_info->endio_meta_workers &&
2379               fs_info->endio_meta_write_workers &&
2380               fs_info->endio_repair_workers &&
2381               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2382               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2383               fs_info->caching_workers && fs_info->readahead_workers &&
2384               fs_info->fixup_workers && fs_info->delayed_workers &&
2385               fs_info->extent_workers &&
2386               fs_info->qgroup_rescan_workers)) {
2387                 return -ENOMEM;
2388         }
2389
2390         return 0;
2391 }
2392
2393 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2394                             struct btrfs_fs_devices *fs_devices)
2395 {
2396         int ret;
2397         struct btrfs_root *tree_root = fs_info->tree_root;
2398         struct btrfs_root *log_tree_root;
2399         struct btrfs_super_block *disk_super = fs_info->super_copy;
2400         u64 bytenr = btrfs_super_log_root(disk_super);
2401
2402         if (fs_devices->rw_devices == 0) {
2403                 btrfs_warn(fs_info, "log replay required on RO media");
2404                 return -EIO;
2405         }
2406
2407         log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2408         if (!log_tree_root)
2409                 return -ENOMEM;
2410
2411         __setup_root(tree_root->nodesize, tree_root->sectorsize,
2412                         tree_root->stripesize, log_tree_root, fs_info,
2413                         BTRFS_TREE_LOG_OBJECTID);
2414
2415         log_tree_root->node = read_tree_block(tree_root, bytenr,
2416                         fs_info->generation + 1);
2417         if (IS_ERR(log_tree_root->node)) {
2418                 btrfs_warn(fs_info, "failed to read log tree");
2419                 ret = PTR_ERR(log_tree_root->node);
2420                 kfree(log_tree_root);
2421                 return ret;
2422         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2423                 btrfs_err(fs_info, "failed to read log tree");
2424                 free_extent_buffer(log_tree_root->node);
2425                 kfree(log_tree_root);
2426                 return -EIO;
2427         }
2428         /* returns with log_tree_root freed on success */
2429         ret = btrfs_recover_log_trees(log_tree_root);
2430         if (ret) {
2431                 btrfs_handle_fs_error(tree_root->fs_info, ret,
2432                             "Failed to recover log tree");
2433                 free_extent_buffer(log_tree_root->node);
2434                 kfree(log_tree_root);
2435                 return ret;
2436         }
2437
2438         if (fs_info->sb->s_flags & MS_RDONLY) {
2439                 ret = btrfs_commit_super(tree_root);
2440                 if (ret)
2441                         return ret;
2442         }
2443
2444         return 0;
2445 }
2446
2447 static int btrfs_read_roots(struct btrfs_fs_info *fs_info,
2448                             struct btrfs_root *tree_root)
2449 {
2450         struct btrfs_root *root;
2451         struct btrfs_key location;
2452         int ret;
2453
2454         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2455         location.type = BTRFS_ROOT_ITEM_KEY;
2456         location.offset = 0;
2457
2458         root = btrfs_read_tree_root(tree_root, &location);
2459         if (IS_ERR(root))
2460                 return PTR_ERR(root);
2461         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2462         fs_info->extent_root = root;
2463
2464         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2465         root = btrfs_read_tree_root(tree_root, &location);
2466         if (IS_ERR(root))
2467                 return PTR_ERR(root);
2468         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2469         fs_info->dev_root = root;
2470         btrfs_init_devices_late(fs_info);
2471
2472         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2473         root = btrfs_read_tree_root(tree_root, &location);
2474         if (IS_ERR(root))
2475                 return PTR_ERR(root);
2476         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2477         fs_info->csum_root = root;
2478
2479         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2480         root = btrfs_read_tree_root(tree_root, &location);
2481         if (!IS_ERR(root)) {
2482                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2483                 fs_info->quota_enabled = 1;
2484                 fs_info->pending_quota_state = 1;
2485                 fs_info->quota_root = root;
2486         }
2487
2488         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2489         root = btrfs_read_tree_root(tree_root, &location);
2490         if (IS_ERR(root)) {
2491                 ret = PTR_ERR(root);
2492                 if (ret != -ENOENT)
2493                         return ret;
2494         } else {
2495                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2496                 fs_info->uuid_root = root;
2497         }
2498
2499         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2500                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2501                 root = btrfs_read_tree_root(tree_root, &location);
2502                 if (IS_ERR(root))
2503                         return PTR_ERR(root);
2504                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2505                 fs_info->free_space_root = root;
2506         }
2507
2508         return 0;
2509 }
2510
2511 int open_ctree(struct super_block *sb,
2512                struct btrfs_fs_devices *fs_devices,
2513                char *options)
2514 {
2515         u32 sectorsize;
2516         u32 nodesize;
2517         u32 stripesize;
2518         u64 generation;
2519         u64 features;
2520         struct btrfs_key location;
2521         struct buffer_head *bh;
2522         struct btrfs_super_block *disk_super;
2523         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2524         struct btrfs_root *tree_root;
2525         struct btrfs_root *chunk_root;
2526         int ret;
2527         int err = -EINVAL;
2528         int num_backups_tried = 0;
2529         int backup_index = 0;
2530         int max_active;
2531
2532         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2533         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
2534         if (!tree_root || !chunk_root) {
2535                 err = -ENOMEM;
2536                 goto fail;
2537         }
2538
2539         ret = init_srcu_struct(&fs_info->subvol_srcu);
2540         if (ret) {
2541                 err = ret;
2542                 goto fail;
2543         }
2544
2545         ret = setup_bdi(fs_info, &fs_info->bdi);
2546         if (ret) {
2547                 err = ret;
2548                 goto fail_srcu;
2549         }
2550
2551         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2552         if (ret) {
2553                 err = ret;
2554                 goto fail_bdi;
2555         }
2556         fs_info->dirty_metadata_batch = PAGE_SIZE *
2557                                         (1 + ilog2(nr_cpu_ids));
2558
2559         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2560         if (ret) {
2561                 err = ret;
2562                 goto fail_dirty_metadata_bytes;
2563         }
2564
2565         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2566         if (ret) {
2567                 err = ret;
2568                 goto fail_delalloc_bytes;
2569         }
2570
2571         fs_info->btree_inode = new_inode(sb);
2572         if (!fs_info->btree_inode) {
2573                 err = -ENOMEM;
2574                 goto fail_bio_counter;
2575         }
2576
2577         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2578
2579         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2580         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2581         INIT_LIST_HEAD(&fs_info->trans_list);
2582         INIT_LIST_HEAD(&fs_info->dead_roots);
2583         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2584         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2585         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2586         spin_lock_init(&fs_info->delalloc_root_lock);
2587         spin_lock_init(&fs_info->trans_lock);
2588         spin_lock_init(&fs_info->fs_roots_radix_lock);
2589         spin_lock_init(&fs_info->delayed_iput_lock);
2590         spin_lock_init(&fs_info->defrag_inodes_lock);
2591         spin_lock_init(&fs_info->free_chunk_lock);
2592         spin_lock_init(&fs_info->tree_mod_seq_lock);
2593         spin_lock_init(&fs_info->super_lock);
2594         spin_lock_init(&fs_info->qgroup_op_lock);
2595         spin_lock_init(&fs_info->buffer_lock);
2596         spin_lock_init(&fs_info->unused_bgs_lock);
2597         rwlock_init(&fs_info->tree_mod_log_lock);
2598         mutex_init(&fs_info->unused_bg_unpin_mutex);
2599         mutex_init(&fs_info->delete_unused_bgs_mutex);
2600         mutex_init(&fs_info->reloc_mutex);
2601         mutex_init(&fs_info->delalloc_root_mutex);
2602         mutex_init(&fs_info->cleaner_delayed_iput_mutex);
2603         seqlock_init(&fs_info->profiles_lock);
2604
2605         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2606         INIT_LIST_HEAD(&fs_info->space_info);
2607         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2608         INIT_LIST_HEAD(&fs_info->unused_bgs);
2609         btrfs_mapping_init(&fs_info->mapping_tree);
2610         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2611                              BTRFS_BLOCK_RSV_GLOBAL);
2612         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2613                              BTRFS_BLOCK_RSV_DELALLOC);
2614         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2615         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2616         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2617         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2618                              BTRFS_BLOCK_RSV_DELOPS);
2619         atomic_set(&fs_info->nr_async_submits, 0);
2620         atomic_set(&fs_info->async_delalloc_pages, 0);
2621         atomic_set(&fs_info->async_submit_draining, 0);
2622         atomic_set(&fs_info->nr_async_bios, 0);
2623         atomic_set(&fs_info->defrag_running, 0);
2624         atomic_set(&fs_info->qgroup_op_seq, 0);
2625         atomic_set(&fs_info->reada_works_cnt, 0);
2626         atomic64_set(&fs_info->tree_mod_seq, 0);
2627         fs_info->sb = sb;
2628         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2629         fs_info->metadata_ratio = 0;
2630         fs_info->defrag_inodes = RB_ROOT;
2631         fs_info->free_chunk_space = 0;
2632         fs_info->tree_mod_log = RB_ROOT;
2633         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2634         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2635         /* readahead state */
2636         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2637         spin_lock_init(&fs_info->reada_lock);
2638
2639         fs_info->thread_pool_size = min_t(unsigned long,
2640                                           num_online_cpus() + 2, 8);
2641
2642         INIT_LIST_HEAD(&fs_info->ordered_roots);
2643         spin_lock_init(&fs_info->ordered_root_lock);
2644         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2645                                         GFP_KERNEL);
2646         if (!fs_info->delayed_root) {
2647                 err = -ENOMEM;
2648                 goto fail_iput;
2649         }
2650         btrfs_init_delayed_root(fs_info->delayed_root);
2651
2652         btrfs_init_scrub(fs_info);
2653 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2654         fs_info->check_integrity_print_mask = 0;
2655 #endif
2656         btrfs_init_balance(fs_info);
2657         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2658
2659         sb->s_blocksize = 4096;
2660         sb->s_blocksize_bits = blksize_bits(4096);
2661         sb->s_bdi = &fs_info->bdi;
2662
2663         btrfs_init_btree_inode(fs_info, tree_root);
2664
2665         spin_lock_init(&fs_info->block_group_cache_lock);
2666         fs_info->block_group_cache_tree = RB_ROOT;
2667         fs_info->first_logical_byte = (u64)-1;
2668
2669         extent_io_tree_init(&fs_info->freed_extents[0],
2670                              fs_info->btree_inode->i_mapping);
2671         extent_io_tree_init(&fs_info->freed_extents[1],
2672                              fs_info->btree_inode->i_mapping);
2673         fs_info->pinned_extents = &fs_info->freed_extents[0];
2674         fs_info->do_barriers = 1;
2675
2676
2677         mutex_init(&fs_info->ordered_operations_mutex);
2678         mutex_init(&fs_info->tree_log_mutex);
2679         mutex_init(&fs_info->chunk_mutex);
2680         mutex_init(&fs_info->transaction_kthread_mutex);
2681         mutex_init(&fs_info->cleaner_mutex);
2682         mutex_init(&fs_info->volume_mutex);
2683         mutex_init(&fs_info->ro_block_group_mutex);
2684         init_rwsem(&fs_info->commit_root_sem);
2685         init_rwsem(&fs_info->cleanup_work_sem);
2686         init_rwsem(&fs_info->subvol_sem);
2687         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2688
2689         btrfs_init_dev_replace_locks(fs_info);
2690         btrfs_init_qgroup(fs_info);
2691
2692         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2693         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2694
2695         init_waitqueue_head(&fs_info->transaction_throttle);
2696         init_waitqueue_head(&fs_info->transaction_wait);
2697         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2698         init_waitqueue_head(&fs_info->async_submit_wait);
2699
2700         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2701
2702         ret = btrfs_alloc_stripe_hash_table(fs_info);
2703         if (ret) {
2704                 err = ret;
2705                 goto fail_alloc;
2706         }
2707
2708         __setup_root(4096, 4096, 4096, tree_root,
2709                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2710
2711         invalidate_bdev(fs_devices->latest_bdev);
2712
2713         /*
2714          * Read super block and check the signature bytes only
2715          */
2716         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2717         if (IS_ERR(bh)) {
2718                 err = PTR_ERR(bh);
2719                 goto fail_alloc;
2720         }
2721
2722         /*
2723          * We want to check superblock checksum, the type is stored inside.
2724          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2725          */
2726         if (btrfs_check_super_csum(bh->b_data)) {
2727                 btrfs_err(fs_info, "superblock checksum mismatch");
2728                 err = -EINVAL;
2729                 brelse(bh);
2730                 goto fail_alloc;
2731         }
2732
2733         /*
2734          * super_copy is zeroed at allocation time and we never touch the
2735          * following bytes up to INFO_SIZE, the checksum is calculated from
2736          * the whole block of INFO_SIZE
2737          */
2738         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2739         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2740                sizeof(*fs_info->super_for_commit));
2741         brelse(bh);
2742
2743         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2744
2745         ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2746         if (ret) {
2747                 btrfs_err(fs_info, "superblock contains fatal errors");
2748                 err = -EINVAL;
2749                 goto fail_alloc;
2750         }
2751
2752         disk_super = fs_info->super_copy;
2753         if (!btrfs_super_root(disk_super))
2754                 goto fail_alloc;
2755
2756         /* check FS state, whether FS is broken. */
2757         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2758                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2759
2760         /*
2761          * run through our array of backup supers and setup
2762          * our ring pointer to the oldest one
2763          */
2764         generation = btrfs_super_generation(disk_super);
2765         find_oldest_super_backup(fs_info, generation);
2766
2767         /*
2768          * In the long term, we'll store the compression type in the super
2769          * block, and it'll be used for per file compression control.
2770          */
2771         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2772
2773         ret = btrfs_parse_options(tree_root, options, sb->s_flags);
2774         if (ret) {
2775                 err = ret;
2776                 goto fail_alloc;
2777         }
2778
2779         features = btrfs_super_incompat_flags(disk_super) &
2780                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2781         if (features) {
2782                 btrfs_err(fs_info,
2783                     "cannot mount because of unsupported optional features (%llx)",
2784                     features);
2785                 err = -EINVAL;
2786                 goto fail_alloc;
2787         }
2788
2789         features = btrfs_super_incompat_flags(disk_super);
2790         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2791         if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2792                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2793
2794         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2795                 btrfs_info(fs_info, "has skinny extents");
2796
2797         /*
2798          * flag our filesystem as having big metadata blocks if
2799          * they are bigger than the page size
2800          */
2801         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
2802                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2803                         btrfs_info(fs_info,
2804                                 "flagging fs with big metadata feature");
2805                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2806         }
2807
2808         nodesize = btrfs_super_nodesize(disk_super);
2809         sectorsize = btrfs_super_sectorsize(disk_super);
2810         stripesize = sectorsize;
2811         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2812         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2813
2814         /*
2815          * mixed block groups end up with duplicate but slightly offset
2816          * extent buffers for the same range.  It leads to corruptions
2817          */
2818         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2819             (sectorsize != nodesize)) {
2820                 btrfs_err(fs_info,
2821 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
2822                         nodesize, sectorsize);
2823                 goto fail_alloc;
2824         }
2825
2826         /*
2827          * Needn't use the lock because there is no other task which will
2828          * update the flag.
2829          */
2830         btrfs_set_super_incompat_flags(disk_super, features);
2831
2832         features = btrfs_super_compat_ro_flags(disk_super) &
2833                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2834         if (!(sb->s_flags & MS_RDONLY) && features) {
2835                 btrfs_err(fs_info,
2836         "cannot mount read-write because of unsupported optional features (%llx)",
2837                        features);
2838                 err = -EINVAL;
2839                 goto fail_alloc;
2840         }
2841
2842         max_active = fs_info->thread_pool_size;
2843
2844         ret = btrfs_init_workqueues(fs_info, fs_devices);
2845         if (ret) {
2846                 err = ret;
2847                 goto fail_sb_buffer;
2848         }
2849
2850         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2851         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2852                                     SZ_4M / PAGE_SIZE);
2853
2854         tree_root->nodesize = nodesize;
2855         tree_root->sectorsize = sectorsize;
2856         tree_root->stripesize = stripesize;
2857
2858         sb->s_blocksize = sectorsize;
2859         sb->s_blocksize_bits = blksize_bits(sectorsize);
2860
2861         mutex_lock(&fs_info->chunk_mutex);
2862         ret = btrfs_read_sys_array(tree_root);
2863         mutex_unlock(&fs_info->chunk_mutex);
2864         if (ret) {
2865                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
2866                 goto fail_sb_buffer;
2867         }
2868
2869         generation = btrfs_super_chunk_root_generation(disk_super);
2870
2871         __setup_root(nodesize, sectorsize, stripesize, chunk_root,
2872                      fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2873
2874         chunk_root->node = read_tree_block(chunk_root,
2875                                            btrfs_super_chunk_root(disk_super),
2876                                            generation);
2877         if (IS_ERR(chunk_root->node) ||
2878             !extent_buffer_uptodate(chunk_root->node)) {
2879                 btrfs_err(fs_info, "failed to read chunk root");
2880                 if (!IS_ERR(chunk_root->node))
2881                         free_extent_buffer(chunk_root->node);
2882                 chunk_root->node = NULL;
2883                 goto fail_tree_roots;
2884         }
2885         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2886         chunk_root->commit_root = btrfs_root_node(chunk_root);
2887
2888         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2889            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2890
2891         ret = btrfs_read_chunk_tree(chunk_root);
2892         if (ret) {
2893                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
2894                 goto fail_tree_roots;
2895         }
2896
2897         /*
2898          * keep the device that is marked to be the target device for the
2899          * dev_replace procedure
2900          */
2901         btrfs_close_extra_devices(fs_devices, 0);
2902
2903         if (!fs_devices->latest_bdev) {
2904                 btrfs_err(fs_info, "failed to read devices");
2905                 goto fail_tree_roots;
2906         }
2907
2908 retry_root_backup:
2909         generation = btrfs_super_generation(disk_super);
2910
2911         tree_root->node = read_tree_block(tree_root,
2912                                           btrfs_super_root(disk_super),
2913                                           generation);
2914         if (IS_ERR(tree_root->node) ||
2915             !extent_buffer_uptodate(tree_root->node)) {
2916                 btrfs_warn(fs_info, "failed to read tree root");
2917                 if (!IS_ERR(tree_root->node))
2918                         free_extent_buffer(tree_root->node);
2919                 tree_root->node = NULL;
2920                 goto recovery_tree_root;
2921         }
2922
2923         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2924         tree_root->commit_root = btrfs_root_node(tree_root);
2925         btrfs_set_root_refs(&tree_root->root_item, 1);
2926
2927         mutex_lock(&tree_root->objectid_mutex);
2928         ret = btrfs_find_highest_objectid(tree_root,
2929                                         &tree_root->highest_objectid);
2930         if (ret) {
2931                 mutex_unlock(&tree_root->objectid_mutex);
2932                 goto recovery_tree_root;
2933         }
2934
2935         ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID);
2936
2937         mutex_unlock(&tree_root->objectid_mutex);
2938
2939         ret = btrfs_read_roots(fs_info, tree_root);
2940         if (ret)
2941                 goto recovery_tree_root;
2942
2943         fs_info->generation = generation;
2944         fs_info->last_trans_committed = generation;
2945
2946         ret = btrfs_recover_balance(fs_info);
2947         if (ret) {
2948                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
2949                 goto fail_block_groups;
2950         }
2951
2952         ret = btrfs_init_dev_stats(fs_info);
2953         if (ret) {
2954                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
2955                 goto fail_block_groups;
2956         }
2957
2958         ret = btrfs_init_dev_replace(fs_info);
2959         if (ret) {
2960                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
2961                 goto fail_block_groups;
2962         }
2963
2964         btrfs_close_extra_devices(fs_devices, 1);
2965
2966         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
2967         if (ret) {
2968                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
2969                                 ret);
2970                 goto fail_block_groups;
2971         }
2972
2973         ret = btrfs_sysfs_add_device(fs_devices);
2974         if (ret) {
2975                 btrfs_err(fs_info, "failed to init sysfs device interface: %d",
2976                                 ret);
2977                 goto fail_fsdev_sysfs;
2978         }
2979
2980         ret = btrfs_sysfs_add_mounted(fs_info);
2981         if (ret) {
2982                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
2983                 goto fail_fsdev_sysfs;
2984         }
2985
2986         ret = btrfs_init_space_info(fs_info);
2987         if (ret) {
2988                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
2989                 goto fail_sysfs;
2990         }
2991
2992         ret = btrfs_read_block_groups(fs_info->extent_root);
2993         if (ret) {
2994                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
2995                 goto fail_sysfs;
2996         }
2997         fs_info->num_tolerated_disk_barrier_failures =
2998                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2999         if (fs_info->fs_devices->missing_devices >
3000              fs_info->num_tolerated_disk_barrier_failures &&
3001             !(sb->s_flags & MS_RDONLY)) {
3002                 btrfs_warn(fs_info,
3003 "missing devices (%llu) exceeds the limit (%d), writeable mount is not allowed",
3004                         fs_info->fs_devices->missing_devices,
3005                         fs_info->num_tolerated_disk_barrier_failures);
3006                 goto fail_sysfs;
3007         }
3008
3009         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3010                                                "btrfs-cleaner");
3011         if (IS_ERR(fs_info->cleaner_kthread))
3012                 goto fail_sysfs;
3013
3014         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3015                                                    tree_root,
3016                                                    "btrfs-transaction");
3017         if (IS_ERR(fs_info->transaction_kthread))
3018                 goto fail_cleaner;
3019
3020         if (!btrfs_test_opt(tree_root->fs_info, SSD) &&
3021             !btrfs_test_opt(tree_root->fs_info, NOSSD) &&
3022             !fs_info->fs_devices->rotating) {
3023                 btrfs_info(fs_info, "detected SSD devices, enabling SSD mode");
3024                 btrfs_set_opt(fs_info->mount_opt, SSD);
3025         }
3026
3027         /*
3028          * Mount does not set all options immediately, we can do it now and do
3029          * not have to wait for transaction commit
3030          */
3031         btrfs_apply_pending_changes(fs_info);
3032
3033 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3034         if (btrfs_test_opt(tree_root->fs_info, CHECK_INTEGRITY)) {
3035                 ret = btrfsic_mount(tree_root, fs_devices,
3036                                     btrfs_test_opt(tree_root->fs_info,
3037                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3038                                     1 : 0,
3039                                     fs_info->check_integrity_print_mask);
3040                 if (ret)
3041                         btrfs_warn(fs_info,
3042                                 "failed to initialize integrity check module: %d",
3043                                 ret);
3044         }
3045 #endif
3046         ret = btrfs_read_qgroup_config(fs_info);
3047         if (ret)
3048                 goto fail_trans_kthread;
3049
3050         /* do not make disk changes in broken FS or nologreplay is given */
3051         if (btrfs_super_log_root(disk_super) != 0 &&
3052             !btrfs_test_opt(tree_root->fs_info, NOLOGREPLAY)) {
3053                 ret = btrfs_replay_log(fs_info, fs_devices);
3054                 if (ret) {
3055                         err = ret;
3056                         goto fail_qgroup;
3057                 }
3058         }
3059
3060         ret = btrfs_find_orphan_roots(tree_root);
3061         if (ret)
3062                 goto fail_qgroup;
3063
3064         if (!(sb->s_flags & MS_RDONLY)) {
3065                 ret = btrfs_cleanup_fs_roots(fs_info);
3066                 if (ret)
3067                         goto fail_qgroup;
3068
3069                 mutex_lock(&fs_info->cleaner_mutex);
3070                 ret = btrfs_recover_relocation(tree_root);
3071                 mutex_unlock(&fs_info->cleaner_mutex);
3072                 if (ret < 0) {
3073                         btrfs_warn(fs_info, "failed to recover relocation: %d",
3074                                         ret);
3075                         err = -EINVAL;
3076                         goto fail_qgroup;
3077                 }
3078         }
3079
3080         location.objectid = BTRFS_FS_TREE_OBJECTID;
3081         location.type = BTRFS_ROOT_ITEM_KEY;
3082         location.offset = 0;
3083
3084         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
3085         if (IS_ERR(fs_info->fs_root)) {
3086                 err = PTR_ERR(fs_info->fs_root);
3087                 goto fail_qgroup;
3088         }
3089
3090         if (sb->s_flags & MS_RDONLY)
3091                 return 0;
3092
3093         if (btrfs_test_opt(tree_root->fs_info, FREE_SPACE_TREE) &&
3094             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3095                 btrfs_info(fs_info, "creating free space tree");
3096                 ret = btrfs_create_free_space_tree(fs_info);
3097                 if (ret) {
3098                         btrfs_warn(fs_info,
3099                                 "failed to create free space tree: %d", ret);
3100                         close_ctree(tree_root);
3101                         return ret;
3102                 }
3103         }
3104
3105         down_read(&fs_info->cleanup_work_sem);
3106         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3107             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3108                 up_read(&fs_info->cleanup_work_sem);
3109                 close_ctree(tree_root);
3110                 return ret;
3111         }
3112         up_read(&fs_info->cleanup_work_sem);
3113
3114         ret = btrfs_resume_balance_async(fs_info);
3115         if (ret) {
3116                 btrfs_warn(fs_info, "failed to resume balance: %d", ret);
3117                 close_ctree(tree_root);
3118                 return ret;
3119         }
3120
3121         ret = btrfs_resume_dev_replace_async(fs_info);
3122         if (ret) {
3123                 btrfs_warn(fs_info, "failed to resume device replace: %d", ret);
3124                 close_ctree(tree_root);
3125                 return ret;
3126         }
3127
3128         btrfs_qgroup_rescan_resume(fs_info);
3129
3130         if (btrfs_test_opt(tree_root->fs_info, CLEAR_CACHE) &&
3131             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3132                 btrfs_info(fs_info, "clearing free space tree");
3133                 ret = btrfs_clear_free_space_tree(fs_info);
3134                 if (ret) {
3135                         btrfs_warn(fs_info,
3136                                 "failed to clear free space tree: %d", ret);
3137                         close_ctree(tree_root);
3138                         return ret;
3139                 }
3140         }
3141
3142         if (!fs_info->uuid_root) {
3143                 btrfs_info(fs_info, "creating UUID tree");
3144                 ret = btrfs_create_uuid_tree(fs_info);
3145                 if (ret) {
3146                         btrfs_warn(fs_info,
3147                                 "failed to create the UUID tree: %d", ret);
3148                         close_ctree(tree_root);
3149                         return ret;
3150                 }
3151         } else if (btrfs_test_opt(tree_root->fs_info, RESCAN_UUID_TREE) ||
3152                    fs_info->generation !=
3153                                 btrfs_super_uuid_tree_generation(disk_super)) {
3154                 btrfs_info(fs_info, "checking UUID tree");
3155                 ret = btrfs_check_uuid_tree(fs_info);
3156                 if (ret) {
3157                         btrfs_warn(fs_info,
3158                                 "failed to check the UUID tree: %d", ret);
3159                         close_ctree(tree_root);
3160                         return ret;
3161                 }
3162         } else {
3163                 fs_info->update_uuid_tree_gen = 1;
3164         }
3165
3166         fs_info->open = 1;
3167
3168         /*
3169          * backuproot only affect mount behavior, and if open_ctree succeeded,
3170          * no need to keep the flag
3171          */
3172         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3173
3174         return 0;
3175
3176 fail_qgroup:
3177         btrfs_free_qgroup_config(fs_info);
3178 fail_trans_kthread:
3179         kthread_stop(fs_info->transaction_kthread);
3180         btrfs_cleanup_transaction(fs_info->tree_root);
3181         btrfs_free_fs_roots(fs_info);
3182 fail_cleaner:
3183         kthread_stop(fs_info->cleaner_kthread);
3184
3185         /*
3186          * make sure we're done with the btree inode before we stop our
3187          * kthreads
3188          */
3189         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3190
3191 fail_sysfs:
3192         btrfs_sysfs_remove_mounted(fs_info);
3193
3194 fail_fsdev_sysfs:
3195         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3196
3197 fail_block_groups:
3198         btrfs_put_block_group_cache(fs_info);
3199         btrfs_free_block_groups(fs_info);
3200
3201 fail_tree_roots:
3202         free_root_pointers(fs_info, 1);
3203         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3204
3205 fail_sb_buffer:
3206         btrfs_stop_all_workers(fs_info);
3207 fail_alloc:
3208 fail_iput:
3209         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3210
3211         iput(fs_info->btree_inode);
3212 fail_bio_counter:
3213         percpu_counter_destroy(&fs_info->bio_counter);
3214 fail_delalloc_bytes:
3215         percpu_counter_destroy(&fs_info->delalloc_bytes);
3216 fail_dirty_metadata_bytes:
3217         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3218 fail_bdi:
3219         bdi_destroy(&fs_info->bdi);
3220 fail_srcu:
3221         cleanup_srcu_struct(&fs_info->subvol_srcu);
3222 fail:
3223         btrfs_free_stripe_hash_table(fs_info);
3224         btrfs_close_devices(fs_info->fs_devices);
3225         return err;
3226
3227 recovery_tree_root:
3228         if (!btrfs_test_opt(tree_root->fs_info, USEBACKUPROOT))
3229                 goto fail_tree_roots;
3230
3231         free_root_pointers(fs_info, 0);
3232
3233         /* don't use the log in recovery mode, it won't be valid */
3234         btrfs_set_super_log_root(disk_super, 0);
3235
3236         /* we can't trust the free space cache either */
3237         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3238
3239         ret = next_root_backup(fs_info, fs_info->super_copy,
3240                                &num_backups_tried, &backup_index);
3241         if (ret == -1)
3242                 goto fail_block_groups;
3243         goto retry_root_backup;
3244 }
3245
3246 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3247 {
3248         if (uptodate) {
3249                 set_buffer_uptodate(bh);
3250         } else {
3251                 struct btrfs_device *device = (struct btrfs_device *)
3252                         bh->b_private;
3253
3254                 btrfs_warn_rl_in_rcu(device->dev_root->fs_info,
3255                                 "lost page write due to IO error on %s",
3256                                           rcu_str_deref(device->name));
3257                 /* note, we don't set_buffer_write_io_error because we have
3258                  * our own ways of dealing with the IO errors
3259                  */
3260                 clear_buffer_uptodate(bh);
3261                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3262         }
3263         unlock_buffer(bh);
3264         put_bh(bh);
3265 }
3266
3267 int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
3268   &n