ASoC: Use card field to indicate whether a component is bound
[linux-2.6-block.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/freezer.h>
29 #include <linux/slab.h>
30 #include <linux/migrate.h>
31 #include <linux/ratelimit.h>
32 #include <linux/uuid.h>
33 #include <linux/semaphore.h>
34 #include <asm/unaligned.h>
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "hash.h"
38 #include "transaction.h"
39 #include "btrfs_inode.h"
40 #include "volumes.h"
41 #include "print-tree.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "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
53 #ifdef CONFIG_X86
54 #include <asm/cpufeature.h>
55 #endif
56
57 static const struct extent_io_ops btree_extent_io_ops;
58 static void end_workqueue_fn(struct btrfs_work *work);
59 static void free_fs_root(struct btrfs_root *root);
60 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
61                                     int read_only);
62 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
63 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
64                                       struct btrfs_root *root);
65 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
66 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
67                                         struct extent_io_tree *dirty_pages,
68                                         int mark);
69 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
70                                        struct extent_io_tree *pinned_extents);
71 static int btrfs_cleanup_transaction(struct btrfs_root *root);
72 static void btrfs_error_commit_super(struct btrfs_root *root);
73
74 /*
75  * btrfs_end_io_wq structs are used to do processing in task context when an IO
76  * is complete.  This is used during reads to verify checksums, and it is used
77  * by writes to insert metadata for new file extents after IO is complete.
78  */
79 struct btrfs_end_io_wq {
80         struct bio *bio;
81         bio_end_io_t *end_io;
82         void *private;
83         struct btrfs_fs_info *info;
84         int error;
85         enum btrfs_wq_endio_type metadata;
86         struct list_head list;
87         struct btrfs_work work;
88 };
89
90 static struct kmem_cache *btrfs_end_io_wq_cache;
91
92 int __init btrfs_end_io_wq_init(void)
93 {
94         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
95                                         sizeof(struct btrfs_end_io_wq),
96                                         0,
97                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
98                                         NULL);
99         if (!btrfs_end_io_wq_cache)
100                 return -ENOMEM;
101         return 0;
102 }
103
104 void btrfs_end_io_wq_exit(void)
105 {
106         if (btrfs_end_io_wq_cache)
107                 kmem_cache_destroy(btrfs_end_io_wq_cache);
108 }
109
110 /*
111  * async submit bios are used to offload expensive checksumming
112  * onto the worker threads.  They checksum file and metadata bios
113  * just before they are sent down the IO stack.
114  */
115 struct async_submit_bio {
116         struct inode *inode;
117         struct bio *bio;
118         struct list_head list;
119         extent_submit_bio_hook_t *submit_bio_start;
120         extent_submit_bio_hook_t *submit_bio_done;
121         int rw;
122         int mirror_num;
123         unsigned long bio_flags;
124         /*
125          * bio_offset is optional, can be used if the pages in the bio
126          * can't tell us where in the file the bio should go
127          */
128         u64 bio_offset;
129         struct btrfs_work work;
130         int error;
131 };
132
133 /*
134  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
135  * eb, the lockdep key is determined by the btrfs_root it belongs to and
136  * the level the eb occupies in the tree.
137  *
138  * Different roots are used for different purposes and may nest inside each
139  * other and they require separate keysets.  As lockdep keys should be
140  * static, assign keysets according to the purpose of the root as indicated
141  * by btrfs_root->objectid.  This ensures that all special purpose roots
142  * have separate keysets.
143  *
144  * Lock-nesting across peer nodes is always done with the immediate parent
145  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
146  * subclass to avoid triggering lockdep warning in such cases.
147  *
148  * The key is set by the readpage_end_io_hook after the buffer has passed
149  * csum validation but before the pages are unlocked.  It is also set by
150  * btrfs_init_new_buffer on freshly allocated blocks.
151  *
152  * We also add a check to make sure the highest level of the tree is the
153  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
154  * needs update as well.
155  */
156 #ifdef CONFIG_DEBUG_LOCK_ALLOC
157 # if BTRFS_MAX_LEVEL != 8
158 #  error
159 # endif
160
161 static struct btrfs_lockdep_keyset {
162         u64                     id;             /* root objectid */
163         const char              *name_stem;     /* lock name stem */
164         char                    names[BTRFS_MAX_LEVEL + 1][20];
165         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
166 } btrfs_lockdep_keysets[] = {
167         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
168         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
169         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
170         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
171         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
172         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
173         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
174         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
175         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
176         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
177         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
178         { .id = 0,                              .name_stem = "tree"     },
179 };
180
181 void __init btrfs_init_lockdep(void)
182 {
183         int i, j;
184
185         /* initialize lockdep class names */
186         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
187                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
188
189                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
190                         snprintf(ks->names[j], sizeof(ks->names[j]),
191                                  "btrfs-%s-%02d", ks->name_stem, j);
192         }
193 }
194
195 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
196                                     int level)
197 {
198         struct btrfs_lockdep_keyset *ks;
199
200         BUG_ON(level >= ARRAY_SIZE(ks->keys));
201
202         /* find the matching keyset, id 0 is the default entry */
203         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
204                 if (ks->id == objectid)
205                         break;
206
207         lockdep_set_class_and_name(&eb->lock,
208                                    &ks->keys[level], ks->names[level]);
209 }
210
211 #endif
212
213 /*
214  * extents on the btree inode are pretty simple, there's one extent
215  * that covers the entire device
216  */
217 static struct extent_map *btree_get_extent(struct inode *inode,
218                 struct page *page, size_t pg_offset, u64 start, u64 len,
219                 int create)
220 {
221         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
222         struct extent_map *em;
223         int ret;
224
225         read_lock(&em_tree->lock);
226         em = lookup_extent_mapping(em_tree, start, len);
227         if (em) {
228                 em->bdev =
229                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
230                 read_unlock(&em_tree->lock);
231                 goto out;
232         }
233         read_unlock(&em_tree->lock);
234
235         em = alloc_extent_map();
236         if (!em) {
237                 em = ERR_PTR(-ENOMEM);
238                 goto out;
239         }
240         em->start = 0;
241         em->len = (u64)-1;
242         em->block_len = (u64)-1;
243         em->block_start = 0;
244         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
245
246         write_lock(&em_tree->lock);
247         ret = add_extent_mapping(em_tree, em, 0);
248         if (ret == -EEXIST) {
249                 free_extent_map(em);
250                 em = lookup_extent_mapping(em_tree, start, len);
251                 if (!em)
252                         em = ERR_PTR(-EIO);
253         } else if (ret) {
254                 free_extent_map(em);
255                 em = ERR_PTR(ret);
256         }
257         write_unlock(&em_tree->lock);
258
259 out:
260         return em;
261 }
262
263 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
264 {
265         return btrfs_crc32c(seed, data, len);
266 }
267
268 void btrfs_csum_final(u32 crc, char *result)
269 {
270         put_unaligned_le32(~crc, result);
271 }
272
273 /*
274  * compute the csum for a btree block, and either verify it or write it
275  * into the csum field of the block.
276  */
277 static int csum_tree_block(struct btrfs_fs_info *fs_info,
278                            struct extent_buffer *buf,
279                            int verify)
280 {
281         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
282         char *result = NULL;
283         unsigned long len;
284         unsigned long cur_len;
285         unsigned long offset = BTRFS_CSUM_SIZE;
286         char *kaddr;
287         unsigned long map_start;
288         unsigned long map_len;
289         int err;
290         u32 crc = ~(u32)0;
291         unsigned long inline_result;
292
293         len = buf->len - offset;
294         while (len > 0) {
295                 err = map_private_extent_buffer(buf, offset, 32,
296                                         &kaddr, &map_start, &map_len);
297                 if (err)
298                         return 1;
299                 cur_len = min(len, map_len - (offset - map_start));
300                 crc = btrfs_csum_data(kaddr + offset - map_start,
301                                       crc, cur_len);
302                 len -= cur_len;
303                 offset += cur_len;
304         }
305         if (csum_size > sizeof(inline_result)) {
306                 result = kzalloc(csum_size, GFP_NOFS);
307                 if (!result)
308                         return 1;
309         } else {
310                 result = (char *)&inline_result;
311         }
312
313         btrfs_csum_final(crc, result);
314
315         if (verify) {
316                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
317                         u32 val;
318                         u32 found = 0;
319                         memcpy(&found, result, csum_size);
320
321                         read_extent_buffer(buf, &val, 0, csum_size);
322                         printk_ratelimited(KERN_WARNING
323                                 "BTRFS: %s checksum verify failed on %llu wanted %X found %X "
324                                 "level %d\n",
325                                 fs_info->sb->s_id, buf->start,
326                                 val, found, btrfs_header_level(buf));
327                         if (result != (char *)&inline_result)
328                                 kfree(result);
329                         return 1;
330                 }
331         } else {
332                 write_extent_buffer(buf, result, 0, csum_size);
333         }
334         if (result != (char *)&inline_result)
335                 kfree(result);
336         return 0;
337 }
338
339 /*
340  * we can't consider a given block up to date unless the transid of the
341  * block matches the transid in the parent node's pointer.  This is how we
342  * detect blocks that either didn't get written at all or got written
343  * in the wrong place.
344  */
345 static int verify_parent_transid(struct extent_io_tree *io_tree,
346                                  struct extent_buffer *eb, u64 parent_transid,
347                                  int atomic)
348 {
349         struct extent_state *cached_state = NULL;
350         int ret;
351         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
352
353         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
354                 return 0;
355
356         if (atomic)
357                 return -EAGAIN;
358
359         if (need_lock) {
360                 btrfs_tree_read_lock(eb);
361                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
362         }
363
364         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
365                          0, &cached_state);
366         if (extent_buffer_uptodate(eb) &&
367             btrfs_header_generation(eb) == parent_transid) {
368                 ret = 0;
369                 goto out;
370         }
371         printk_ratelimited(KERN_ERR
372             "BTRFS (device %s): parent transid verify failed on %llu wanted %llu found %llu\n",
373                         eb->fs_info->sb->s_id, eb->start,
374                         parent_transid, btrfs_header_generation(eb));
375         ret = 1;
376
377         /*
378          * Things reading via commit roots that don't have normal protection,
379          * like send, can have a really old block in cache that may point at a
380          * block that has been free'd and re-allocated.  So don't clear uptodate
381          * if we find an eb that is under IO (dirty/writeback) because we could
382          * end up reading in the stale data and then writing it back out and
383          * making everybody very sad.
384          */
385         if (!extent_buffer_under_io(eb))
386                 clear_extent_buffer_uptodate(eb);
387 out:
388         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
389                              &cached_state, GFP_NOFS);
390         if (need_lock)
391                 btrfs_tree_read_unlock_blocking(eb);
392         return ret;
393 }
394
395 /*
396  * Return 0 if the superblock checksum type matches the checksum value of that
397  * algorithm. Pass the raw disk superblock data.
398  */
399 static int btrfs_check_super_csum(char *raw_disk_sb)
400 {
401         struct btrfs_super_block *disk_sb =
402                 (struct btrfs_super_block *)raw_disk_sb;
403         u16 csum_type = btrfs_super_csum_type(disk_sb);
404         int ret = 0;
405
406         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
407                 u32 crc = ~(u32)0;
408                 const int csum_size = sizeof(crc);
409                 char result[csum_size];
410
411                 /*
412                  * The super_block structure does not span the whole
413                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
414                  * is filled with zeros and is included in the checkum.
415                  */
416                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
417                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
418                 btrfs_csum_final(crc, result);
419
420                 if (memcmp(raw_disk_sb, result, csum_size))
421                         ret = 1;
422         }
423
424         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
425                 printk(KERN_ERR "BTRFS: unsupported checksum algorithm %u\n",
426                                 csum_type);
427                 ret = 1;
428         }
429
430         return ret;
431 }
432
433 /*
434  * helper to read a given tree block, doing retries as required when
435  * the checksums don't match and we have alternate mirrors to try.
436  */
437 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
438                                           struct extent_buffer *eb,
439                                           u64 start, u64 parent_transid)
440 {
441         struct extent_io_tree *io_tree;
442         int failed = 0;
443         int ret;
444         int num_copies = 0;
445         int mirror_num = 0;
446         int failed_mirror = 0;
447
448         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
449         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
450         while (1) {
451                 ret = read_extent_buffer_pages(io_tree, eb, start,
452                                                WAIT_COMPLETE,
453                                                btree_get_extent, mirror_num);
454                 if (!ret) {
455                         if (!verify_parent_transid(io_tree, eb,
456                                                    parent_transid, 0))
457                                 break;
458                         else
459                                 ret = -EIO;
460                 }
461
462                 /*
463                  * This buffer's crc is fine, but its contents are corrupted, so
464                  * there is no reason to read the other copies, they won't be
465                  * any less wrong.
466                  */
467                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
468                         break;
469
470                 num_copies = btrfs_num_copies(root->fs_info,
471                                               eb->start, eb->len);
472                 if (num_copies == 1)
473                         break;
474
475                 if (!failed_mirror) {
476                         failed = 1;
477                         failed_mirror = eb->read_mirror;
478                 }
479
480                 mirror_num++;
481                 if (mirror_num == failed_mirror)
482                         mirror_num++;
483
484                 if (mirror_num > num_copies)
485                         break;
486         }
487
488         if (failed && !ret && failed_mirror)
489                 repair_eb_io_failure(root, eb, failed_mirror);
490
491         return ret;
492 }
493
494 /*
495  * checksum a dirty tree block before IO.  This has extra checks to make sure
496  * we only fill in the checksum field in the first page of a multi-page block
497  */
498
499 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
500 {
501         u64 start = page_offset(page);
502         u64 found_start;
503         struct extent_buffer *eb;
504
505         eb = (struct extent_buffer *)page->private;
506         if (page != eb->pages[0])
507                 return 0;
508         found_start = btrfs_header_bytenr(eb);
509         if (WARN_ON(found_start != start || !PageUptodate(page)))
510                 return 0;
511         csum_tree_block(fs_info, eb, 0);
512         return 0;
513 }
514
515 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
516                                  struct extent_buffer *eb)
517 {
518         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
519         u8 fsid[BTRFS_UUID_SIZE];
520         int ret = 1;
521
522         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
523         while (fs_devices) {
524                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
525                         ret = 0;
526                         break;
527                 }
528                 fs_devices = fs_devices->seed;
529         }
530         return ret;
531 }
532
533 #define CORRUPT(reason, eb, root, slot)                         \
534         btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu,"       \
535                    "root=%llu, slot=%d", reason,                        \
536                btrfs_header_bytenr(eb), root->objectid, slot)
537
538 static noinline int check_leaf(struct btrfs_root *root,
539                                struct extent_buffer *leaf)
540 {
541         struct btrfs_key key;
542         struct btrfs_key leaf_key;
543         u32 nritems = btrfs_header_nritems(leaf);
544         int slot;
545
546         if (nritems == 0)
547                 return 0;
548
549         /* Check the 0 item */
550         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
551             BTRFS_LEAF_DATA_SIZE(root)) {
552                 CORRUPT("invalid item offset size pair", leaf, root, 0);
553                 return -EIO;
554         }
555
556         /*
557          * Check to make sure each items keys are in the correct order and their
558          * offsets make sense.  We only have to loop through nritems-1 because
559          * we check the current slot against the next slot, which verifies the
560          * next slot's offset+size makes sense and that the current's slot
561          * offset is correct.
562          */
563         for (slot = 0; slot < nritems - 1; slot++) {
564                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
565                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
566
567                 /* Make sure the keys are in the right order */
568                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
569                         CORRUPT("bad key order", leaf, root, slot);
570                         return -EIO;
571                 }
572
573                 /*
574                  * Make sure the offset and ends are right, remember that the
575                  * item data starts at the end of the leaf and grows towards the
576                  * front.
577                  */
578                 if (btrfs_item_offset_nr(leaf, slot) !=
579                         btrfs_item_end_nr(leaf, slot + 1)) {
580                         CORRUPT("slot offset bad", leaf, root, slot);
581                         return -EIO;
582                 }
583
584                 /*
585                  * Check to make sure that we don't point outside of the leaf,
586                  * just incase all the items are consistent to eachother, but
587                  * all point outside of the leaf.
588                  */
589                 if (btrfs_item_end_nr(leaf, slot) >
590                     BTRFS_LEAF_DATA_SIZE(root)) {
591                         CORRUPT("slot end outside of leaf", leaf, root, slot);
592                         return -EIO;
593                 }
594         }
595
596         return 0;
597 }
598
599 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
600                                       u64 phy_offset, struct page *page,
601                                       u64 start, u64 end, int mirror)
602 {
603         u64 found_start;
604         int found_level;
605         struct extent_buffer *eb;
606         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
607         int ret = 0;
608         int reads_done;
609
610         if (!page->private)
611                 goto out;
612
613         eb = (struct extent_buffer *)page->private;
614
615         /* the pending IO might have been the only thing that kept this buffer
616          * in memory.  Make sure we have a ref for all this other checks
617          */
618         extent_buffer_get(eb);
619
620         reads_done = atomic_dec_and_test(&eb->io_pages);
621         if (!reads_done)
622                 goto err;
623
624         eb->read_mirror = mirror;
625         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
626                 ret = -EIO;
627                 goto err;
628         }
629
630         found_start = btrfs_header_bytenr(eb);
631         if (found_start != eb->start) {
632                 printk_ratelimited(KERN_ERR "BTRFS (device %s): bad tree block start "
633                                "%llu %llu\n",
634                                eb->fs_info->sb->s_id, found_start, eb->start);
635                 ret = -EIO;
636                 goto err;
637         }
638         if (check_tree_block_fsid(root->fs_info, eb)) {
639                 printk_ratelimited(KERN_ERR "BTRFS (device %s): bad fsid on block %llu\n",
640                                eb->fs_info->sb->s_id, eb->start);
641                 ret = -EIO;
642                 goto err;
643         }
644         found_level = btrfs_header_level(eb);
645         if (found_level >= BTRFS_MAX_LEVEL) {
646                 btrfs_err(root->fs_info, "bad tree block level %d",
647                            (int)btrfs_header_level(eb));
648                 ret = -EIO;
649                 goto err;
650         }
651
652         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
653                                        eb, found_level);
654
655         ret = csum_tree_block(root->fs_info, eb, 1);
656         if (ret) {
657                 ret = -EIO;
658                 goto err;
659         }
660
661         /*
662          * If this is a leaf block and it is corrupt, set the corrupt bit so
663          * that we don't try and read the other copies of this block, just
664          * return -EIO.
665          */
666         if (found_level == 0 && check_leaf(root, eb)) {
667                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
668                 ret = -EIO;
669         }
670
671         if (!ret)
672                 set_extent_buffer_uptodate(eb);
673 err:
674         if (reads_done &&
675             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
676                 btree_readahead_hook(root, eb, eb->start, ret);
677
678         if (ret) {
679                 /*
680                  * our io error hook is going to dec the io pages
681                  * again, we have to make sure it has something
682                  * to decrement
683                  */
684                 atomic_inc(&eb->io_pages);
685                 clear_extent_buffer_uptodate(eb);
686         }
687         free_extent_buffer(eb);
688 out:
689         return ret;
690 }
691
692 static int btree_io_failed_hook(struct page *page, int failed_mirror)
693 {
694         struct extent_buffer *eb;
695         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
696
697         eb = (struct extent_buffer *)page->private;
698         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
699         eb->read_mirror = failed_mirror;
700         atomic_dec(&eb->io_pages);
701         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
702                 btree_readahead_hook(root, eb, eb->start, -EIO);
703         return -EIO;    /* we fixed nothing */
704 }
705
706 static void end_workqueue_bio(struct bio *bio, int err)
707 {
708         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
709         struct btrfs_fs_info *fs_info;
710         struct btrfs_workqueue *wq;
711         btrfs_work_func_t func;
712
713         fs_info = end_io_wq->info;
714         end_io_wq->error = err;
715
716         if (bio->bi_rw & REQ_WRITE) {
717                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
718                         wq = fs_info->endio_meta_write_workers;
719                         func = btrfs_endio_meta_write_helper;
720                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
721                         wq = fs_info->endio_freespace_worker;
722                         func = btrfs_freespace_write_helper;
723                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
724                         wq = fs_info->endio_raid56_workers;
725                         func = btrfs_endio_raid56_helper;
726                 } else {
727                         wq = fs_info->endio_write_workers;
728                         func = btrfs_endio_write_helper;
729                 }
730         } else {
731                 if (unlikely(end_io_wq->metadata ==
732                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
733                         wq = fs_info->endio_repair_workers;
734                         func = btrfs_endio_repair_helper;
735                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
736                         wq = fs_info->endio_raid56_workers;
737                         func = btrfs_endio_raid56_helper;
738                 } else if (end_io_wq->metadata) {
739                         wq = fs_info->endio_meta_workers;
740                         func = btrfs_endio_meta_helper;
741                 } else {
742                         wq = fs_info->endio_workers;
743                         func = btrfs_endio_helper;
744                 }
745         }
746
747         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
748         btrfs_queue_work(wq, &end_io_wq->work);
749 }
750
751 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
752                         enum btrfs_wq_endio_type metadata)
753 {
754         struct btrfs_end_io_wq *end_io_wq;
755
756         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
757         if (!end_io_wq)
758                 return -ENOMEM;
759
760         end_io_wq->private = bio->bi_private;
761         end_io_wq->end_io = bio->bi_end_io;
762         end_io_wq->info = info;
763         end_io_wq->error = 0;
764         end_io_wq->bio = bio;
765         end_io_wq->metadata = metadata;
766
767         bio->bi_private = end_io_wq;
768         bio->bi_end_io = end_workqueue_bio;
769         return 0;
770 }
771
772 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
773 {
774         unsigned long limit = min_t(unsigned long,
775                                     info->thread_pool_size,
776                                     info->fs_devices->open_devices);
777         return 256 * limit;
778 }
779
780 static void run_one_async_start(struct btrfs_work *work)
781 {
782         struct async_submit_bio *async;
783         int ret;
784
785         async = container_of(work, struct  async_submit_bio, work);
786         ret = async->submit_bio_start(async->inode, async->rw, async->bio,
787                                       async->mirror_num, async->bio_flags,
788                                       async->bio_offset);
789         if (ret)
790                 async->error = ret;
791 }
792
793 static void run_one_async_done(struct btrfs_work *work)
794 {
795         struct btrfs_fs_info *fs_info;
796         struct async_submit_bio *async;
797         int limit;
798
799         async = container_of(work, struct  async_submit_bio, work);
800         fs_info = BTRFS_I(async->inode)->root->fs_info;
801
802         limit = btrfs_async_submit_limit(fs_info);
803         limit = limit * 2 / 3;
804
805         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
806             waitqueue_active(&fs_info->async_submit_wait))
807                 wake_up(&fs_info->async_submit_wait);
808
809         /* If an error occured we just want to clean up the bio and move on */
810         if (async->error) {
811                 bio_endio(async->bio, async->error);
812                 return;
813         }
814
815         async->submit_bio_done(async->inode, async->rw, async->bio,
816                                async->mirror_num, async->bio_flags,
817                                async->bio_offset);
818 }
819
820 static void run_one_async_free(struct btrfs_work *work)
821 {
822         struct async_submit_bio *async;
823
824         async = container_of(work, struct  async_submit_bio, work);
825         kfree(async);
826 }
827
828 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
829                         int rw, struct bio *bio, int mirror_num,
830                         unsigned long bio_flags,
831                         u64 bio_offset,
832                         extent_submit_bio_hook_t *submit_bio_start,
833                         extent_submit_bio_hook_t *submit_bio_done)
834 {
835         struct async_submit_bio *async;
836
837         async = kmalloc(sizeof(*async), GFP_NOFS);
838         if (!async)
839                 return -ENOMEM;
840
841         async->inode = inode;
842         async->rw = rw;
843         async->bio = bio;
844         async->mirror_num = mirror_num;
845         async->submit_bio_start = submit_bio_start;
846         async->submit_bio_done = submit_bio_done;
847
848         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
849                         run_one_async_done, run_one_async_free);
850
851         async->bio_flags = bio_flags;
852         async->bio_offset = bio_offset;
853
854         async->error = 0;
855
856         atomic_inc(&fs_info->nr_async_submits);
857
858         if (rw & REQ_SYNC)
859                 btrfs_set_work_high_priority(&async->work);
860
861         btrfs_queue_work(fs_info->workers, &async->work);
862
863         while (atomic_read(&fs_info->async_submit_draining) &&
864               atomic_read(&fs_info->nr_async_submits)) {
865                 wait_event(fs_info->async_submit_wait,
866                            (atomic_read(&fs_info->nr_async_submits) == 0));
867         }
868
869         return 0;
870 }
871
872 static int btree_csum_one_bio(struct bio *bio)
873 {
874         struct bio_vec *bvec;
875         struct btrfs_root *root;
876         int i, ret = 0;
877
878         bio_for_each_segment_all(bvec, bio, i) {
879                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
880                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
881                 if (ret)
882                         break;
883         }
884
885         return ret;
886 }
887
888 static int __btree_submit_bio_start(struct inode *inode, int rw,
889                                     struct bio *bio, int mirror_num,
890                                     unsigned long bio_flags,
891                                     u64 bio_offset)
892 {
893         /*
894          * when we're called for a write, we're already in the async
895          * submission context.  Just jump into btrfs_map_bio
896          */
897         return btree_csum_one_bio(bio);
898 }
899
900 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
901                                  int mirror_num, unsigned long bio_flags,
902                                  u64 bio_offset)
903 {
904         int ret;
905
906         /*
907          * when we're called for a write, we're already in the async
908          * submission context.  Just jump into btrfs_map_bio
909          */
910         ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
911         if (ret)
912                 bio_endio(bio, ret);
913         return ret;
914 }
915
916 static int check_async_write(struct inode *inode, unsigned long bio_flags)
917 {
918         if (bio_flags & EXTENT_BIO_TREE_LOG)
919                 return 0;
920 #ifdef CONFIG_X86
921         if (cpu_has_xmm4_2)
922                 return 0;
923 #endif
924         return 1;
925 }
926
927 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
928                                  int mirror_num, unsigned long bio_flags,
929                                  u64 bio_offset)
930 {
931         int async = check_async_write(inode, bio_flags);
932         int ret;
933
934         if (!(rw & REQ_WRITE)) {
935                 /*
936                  * called for a read, do the setup so that checksum validation
937                  * can happen in the async kernel threads
938                  */
939                 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
940                                           bio, BTRFS_WQ_ENDIO_METADATA);
941                 if (ret)
942                         goto out_w_error;
943                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
944                                     mirror_num, 0);
945         } else if (!async) {
946                 ret = btree_csum_one_bio(bio);
947                 if (ret)
948                         goto out_w_error;
949                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
950                                     mirror_num, 0);
951         } else {
952                 /*
953                  * kthread helpers are used to submit writes so that
954                  * checksumming can happen in parallel across all CPUs
955                  */
956                 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
957                                           inode, rw, bio, mirror_num, 0,
958                                           bio_offset,
959                                           __btree_submit_bio_start,
960                                           __btree_submit_bio_done);
961         }
962
963         if (ret) {
964 out_w_error:
965                 bio_endio(bio, ret);
966         }
967         return ret;
968 }
969
970 #ifdef CONFIG_MIGRATION
971 static int btree_migratepage(struct address_space *mapping,
972                         struct page *newpage, struct page *page,
973                         enum migrate_mode mode)
974 {
975         /*
976          * we can't safely write a btree page from here,
977          * we haven't done the locking hook
978          */
979         if (PageDirty(page))
980                 return -EAGAIN;
981         /*
982          * Buffers may be managed in a filesystem specific way.
983          * We must have no buffers or drop them.
984          */
985         if (page_has_private(page) &&
986             !try_to_release_page(page, GFP_KERNEL))
987                 return -EAGAIN;
988         return migrate_page(mapping, newpage, page, mode);
989 }
990 #endif
991
992
993 static int btree_writepages(struct address_space *mapping,
994                             struct writeback_control *wbc)
995 {
996         struct btrfs_fs_info *fs_info;
997         int ret;
998
999         if (wbc->sync_mode == WB_SYNC_NONE) {
1000
1001                 if (wbc->for_kupdate)
1002                         return 0;
1003
1004                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1005                 /* this is a bit racy, but that's ok */
1006                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1007                                              BTRFS_DIRTY_METADATA_THRESH);
1008                 if (ret < 0)
1009                         return 0;
1010         }
1011         return btree_write_cache_pages(mapping, wbc);
1012 }
1013
1014 static int btree_readpage(struct file *file, struct page *page)
1015 {
1016         struct extent_io_tree *tree;
1017         tree = &BTRFS_I(page->mapping->host)->io_tree;
1018         return extent_read_full_page(tree, page, btree_get_extent, 0);
1019 }
1020
1021 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1022 {
1023         if (PageWriteback(page) || PageDirty(page))
1024                 return 0;
1025
1026         return try_release_extent_buffer(page);
1027 }
1028
1029 static void btree_invalidatepage(struct page *page, unsigned int offset,
1030                                  unsigned int length)
1031 {
1032         struct extent_io_tree *tree;
1033         tree = &BTRFS_I(page->mapping->host)->io_tree;
1034         extent_invalidatepage(tree, page, offset);
1035         btree_releasepage(page, GFP_NOFS);
1036         if (PagePrivate(page)) {
1037                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1038                            "page private not zero on page %llu",
1039                            (unsigned long long)page_offset(page));
1040                 ClearPagePrivate(page);
1041                 set_page_private(page, 0);
1042                 page_cache_release(page);
1043         }
1044 }
1045
1046 static int btree_set_page_dirty(struct page *page)
1047 {
1048 #ifdef DEBUG
1049         struct extent_buffer *eb;
1050
1051         BUG_ON(!PagePrivate(page));
1052         eb = (struct extent_buffer *)page->private;
1053         BUG_ON(!eb);
1054         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1055         BUG_ON(!atomic_read(&eb->refs));
1056         btrfs_assert_tree_locked(eb);
1057 #endif
1058         return __set_page_dirty_nobuffers(page);
1059 }
1060
1061 static const struct address_space_operations btree_aops = {
1062         .readpage       = btree_readpage,
1063         .writepages     = btree_writepages,
1064         .releasepage    = btree_releasepage,
1065         .invalidatepage = btree_invalidatepage,
1066 #ifdef CONFIG_MIGRATION
1067         .migratepage    = btree_migratepage,
1068 #endif
1069         .set_page_dirty = btree_set_page_dirty,
1070 };
1071
1072 void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
1073 {
1074         struct extent_buffer *buf = NULL;
1075         struct inode *btree_inode = root->fs_info->btree_inode;
1076
1077         buf = btrfs_find_create_tree_block(root, bytenr);
1078         if (!buf)
1079                 return;
1080         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1081                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1082         free_extent_buffer(buf);
1083 }
1084
1085 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
1086                          int mirror_num, struct extent_buffer **eb)
1087 {
1088         struct extent_buffer *buf = NULL;
1089         struct inode *btree_inode = root->fs_info->btree_inode;
1090         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1091         int ret;
1092
1093         buf = btrfs_find_create_tree_block(root, bytenr);
1094         if (!buf)
1095                 return 0;
1096
1097         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1098
1099         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1100                                        btree_get_extent, mirror_num);
1101         if (ret) {
1102                 free_extent_buffer(buf);
1103                 return ret;
1104         }
1105
1106         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1107                 free_extent_buffer(buf);
1108                 return -EIO;
1109         } else if (extent_buffer_uptodate(buf)) {
1110                 *eb = buf;
1111         } else {
1112                 free_extent_buffer(buf);
1113         }
1114         return 0;
1115 }
1116
1117 struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
1118                                             u64 bytenr)
1119 {
1120         return find_extent_buffer(fs_info, bytenr);
1121 }
1122
1123 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1124                                                  u64 bytenr)
1125 {
1126         if (btrfs_test_is_dummy_root(root))
1127                 return alloc_test_extent_buffer(root->fs_info, bytenr);
1128         return alloc_extent_buffer(root->fs_info, bytenr);
1129 }
1130
1131
1132 int btrfs_write_tree_block(struct extent_buffer *buf)
1133 {
1134         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1135                                         buf->start + buf->len - 1);
1136 }
1137
1138 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1139 {
1140         return filemap_fdatawait_range(buf->pages[0]->mapping,
1141                                        buf->start, buf->start + buf->len - 1);
1142 }
1143
1144 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1145                                       u64 parent_transid)
1146 {
1147         struct extent_buffer *buf = NULL;
1148         int ret;
1149
1150         buf = btrfs_find_create_tree_block(root, bytenr);
1151         if (!buf)
1152                 return ERR_PTR(-ENOMEM);
1153
1154         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1155         if (ret) {
1156                 free_extent_buffer(buf);
1157                 return ERR_PTR(ret);
1158         }
1159         return buf;
1160
1161 }
1162
1163 void clean_tree_block(struct btrfs_trans_handle *trans,
1164                       struct btrfs_fs_info *fs_info,
1165                       struct extent_buffer *buf)
1166 {
1167         if (btrfs_header_generation(buf) ==
1168             fs_info->running_transaction->transid) {
1169                 btrfs_assert_tree_locked(buf);
1170
1171                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1172                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1173                                              -buf->len,
1174                                              fs_info->dirty_metadata_batch);
1175                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1176                         btrfs_set_lock_blocking(buf);
1177                         clear_extent_buffer_dirty(buf);
1178                 }
1179         }
1180 }
1181
1182 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1183 {
1184         struct btrfs_subvolume_writers *writers;
1185         int ret;
1186
1187         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1188         if (!writers)
1189                 return ERR_PTR(-ENOMEM);
1190
1191         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1192         if (ret < 0) {
1193                 kfree(writers);
1194                 return ERR_PTR(ret);
1195         }
1196
1197         init_waitqueue_head(&writers->wait);
1198         return writers;
1199 }
1200
1201 static void
1202 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1203 {
1204         percpu_counter_destroy(&writers->counter);
1205         kfree(writers);
1206 }
1207
1208 static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
1209                          struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1210                          u64 objectid)
1211 {
1212         root->node = NULL;
1213         root->commit_root = NULL;
1214         root->sectorsize = sectorsize;
1215         root->nodesize = nodesize;
1216         root->stripesize = stripesize;
1217         root->state = 0;
1218         root->orphan_cleanup_state = 0;
1219
1220         root->objectid = objectid;
1221         root->last_trans = 0;
1222         root->highest_objectid = 0;
1223         root->nr_delalloc_inodes = 0;
1224         root->nr_ordered_extents = 0;
1225         root->name = NULL;
1226         root->inode_tree = RB_ROOT;
1227         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1228         root->block_rsv = NULL;
1229         root->orphan_block_rsv = NULL;
1230
1231         INIT_LIST_HEAD(&root->dirty_list);
1232         INIT_LIST_HEAD(&root->root_list);
1233         INIT_LIST_HEAD(&root->delalloc_inodes);
1234         INIT_LIST_HEAD(&root->delalloc_root);
1235         INIT_LIST_HEAD(&root->ordered_extents);
1236         INIT_LIST_HEAD(&root->ordered_root);
1237         INIT_LIST_HEAD(&root->logged_list[0]);
1238         INIT_LIST_HEAD(&root->logged_list[1]);
1239         spin_lock_init(&root->orphan_lock);
1240         spin_lock_init(&root->inode_lock);
1241         spin_lock_init(&root->delalloc_lock);
1242         spin_lock_init(&root->ordered_extent_lock);
1243         spin_lock_init(&root->accounting_lock);
1244         spin_lock_init(&root->log_extents_lock[0]);
1245         spin_lock_init(&root->log_extents_lock[1]);
1246         mutex_init(&root->objectid_mutex);
1247         mutex_init(&root->log_mutex);
1248         mutex_init(&root->ordered_extent_mutex);
1249         mutex_init(&root->delalloc_mutex);
1250         init_waitqueue_head(&root->log_writer_wait);
1251         init_waitqueue_head(&root->log_commit_wait[0]);
1252         init_waitqueue_head(&root->log_commit_wait[1]);
1253         INIT_LIST_HEAD(&root->log_ctxs[0]);
1254         INIT_LIST_HEAD(&root->log_ctxs[1]);
1255         atomic_set(&root->log_commit[0], 0);
1256         atomic_set(&root->log_commit[1], 0);
1257         atomic_set(&root->log_writers, 0);
1258         atomic_set(&root->log_batch, 0);
1259         atomic_set(&root->orphan_inodes, 0);
1260         atomic_set(&root->refs, 1);
1261         atomic_set(&root->will_be_snapshoted, 0);
1262         root->log_transid = 0;
1263         root->log_transid_committed = -1;
1264         root->last_log_commit = 0;
1265         if (fs_info)
1266                 extent_io_tree_init(&root->dirty_log_pages,
1267                                      fs_info->btree_inode->i_mapping);
1268
1269         memset(&root->root_key, 0, sizeof(root->root_key));
1270         memset(&root->root_item, 0, sizeof(root->root_item));
1271         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1272         if (fs_info)
1273                 root->defrag_trans_start = fs_info->generation;
1274         else
1275                 root->defrag_trans_start = 0;
1276         root->root_key.objectid = objectid;
1277         root->anon_dev = 0;
1278
1279         spin_lock_init(&root->root_item_lock);
1280 }
1281
1282 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
1283 {
1284         struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
1285         if (root)
1286                 root->fs_info = fs_info;
1287         return root;
1288 }
1289
1290 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1291 /* Should only be used by the testing infrastructure */
1292 struct btrfs_root *btrfs_alloc_dummy_root(void)
1293 {
1294         struct btrfs_root *root;
1295
1296         root = btrfs_alloc_root(NULL);
1297         if (!root)
1298                 return ERR_PTR(-ENOMEM);
1299         __setup_root(4096, 4096, 4096, root, NULL, 1);
1300         set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
1301         root->alloc_bytenr = 0;
1302
1303         return root;
1304 }
1305 #endif
1306
1307 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1308                                      struct btrfs_fs_info *fs_info,
1309                                      u64 objectid)
1310 {
1311         struct extent_buffer *leaf;
1312         struct btrfs_root *tree_root = fs_info->tree_root;
1313         struct btrfs_root *root;
1314         struct btrfs_key key;
1315         int ret = 0;
1316         uuid_le uuid;
1317
1318         root = btrfs_alloc_root(fs_info);
1319         if (!root)
1320                 return ERR_PTR(-ENOMEM);
1321
1322         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1323                 tree_root->stripesize, root, fs_info, objectid);
1324         root->root_key.objectid = objectid;
1325         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1326         root->root_key.offset = 0;
1327
1328         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1329         if (IS_ERR(leaf)) {
1330                 ret = PTR_ERR(leaf);
1331                 leaf = NULL;
1332                 goto fail;
1333         }
1334
1335         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1336         btrfs_set_header_bytenr(leaf, leaf->start);
1337         btrfs_set_header_generation(leaf, trans->transid);
1338         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1339         btrfs_set_header_owner(leaf, objectid);
1340         root->node = leaf;
1341
1342         write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(),
1343                             BTRFS_FSID_SIZE);
1344         write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1345                             btrfs_header_chunk_tree_uuid(leaf),
1346                             BTRFS_UUID_SIZE);
1347         btrfs_mark_buffer_dirty(leaf);
1348
1349         root->commit_root = btrfs_root_node(root);
1350         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1351
1352         root->root_item.flags = 0;
1353         root->root_item.byte_limit = 0;
1354         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1355         btrfs_set_root_generation(&root->root_item, trans->transid);
1356         btrfs_set_root_level(&root->root_item, 0);
1357         btrfs_set_root_refs(&root->root_item, 1);
1358         btrfs_set_root_used(&root->root_item, leaf->len);
1359         btrfs_set_root_last_snapshot(&root->root_item, 0);
1360         btrfs_set_root_dirid(&root->root_item, 0);
1361         uuid_le_gen(&uuid);
1362         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1363         root->root_item.drop_level = 0;
1364
1365         key.objectid = objectid;
1366         key.type = BTRFS_ROOT_ITEM_KEY;
1367         key.offset = 0;
1368         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1369         if (ret)
1370                 goto fail;
1371
1372         btrfs_tree_unlock(leaf);
1373
1374         return root;
1375
1376 fail:
1377         if (leaf) {
1378                 btrfs_tree_unlock(leaf);
1379                 free_extent_buffer(root->commit_root);
1380                 free_extent_buffer(leaf);
1381         }
1382         kfree(root);
1383
1384         return ERR_PTR(ret);
1385 }
1386
1387 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1388                                          struct btrfs_fs_info *fs_info)
1389 {
1390         struct btrfs_root *root;
1391         struct btrfs_root *tree_root = fs_info->tree_root;
1392         struct extent_buffer *leaf;
1393
1394         root = btrfs_alloc_root(fs_info);
1395         if (!root)
1396                 return ERR_PTR(-ENOMEM);
1397
1398         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1399                      tree_root->stripesize, root, fs_info,
1400                      BTRFS_TREE_LOG_OBJECTID);
1401
1402         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1403         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1404         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1405
1406         /*
1407          * DON'T set REF_COWS for log trees
1408          *
1409          * log trees do not get reference counted because they go away
1410          * before a real commit is actually done.  They do store pointers
1411          * to file data extents, and those reference counts still get
1412          * updated (along with back refs to the log tree).
1413          */
1414
1415         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1416                         NULL, 0, 0, 0);
1417         if (IS_ERR(leaf)) {
1418                 kfree(root);
1419                 return ERR_CAST(leaf);
1420         }
1421
1422         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1423         btrfs_set_header_bytenr(leaf, leaf->start);
1424         btrfs_set_header_generation(leaf, trans->transid);
1425         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1426         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1427         root->node = leaf;
1428
1429         write_extent_buffer(root->node, root->fs_info->fsid,
1430                             btrfs_header_fsid(), BTRFS_FSID_SIZE);
1431         btrfs_mark_buffer_dirty(root->node);
1432         btrfs_tree_unlock(root->node);
1433         return root;
1434 }
1435
1436 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1437                              struct btrfs_fs_info *fs_info)
1438 {
1439         struct btrfs_root *log_root;
1440
1441         log_root = alloc_log_tree(trans, fs_info);
1442         if (IS_ERR(log_root))
1443                 return PTR_ERR(log_root);
1444         WARN_ON(fs_info->log_root_tree);
1445         fs_info->log_root_tree = log_root;
1446         return 0;
1447 }
1448
1449 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1450                        struct btrfs_root *root)
1451 {
1452         struct btrfs_root *log_root;
1453         struct btrfs_inode_item *inode_item;
1454
1455         log_root = alloc_log_tree(trans, root->fs_info);
1456         if (IS_ERR(log_root))
1457                 return PTR_ERR(log_root);
1458
1459         log_root->last_trans = trans->transid;
1460         log_root->root_key.offset = root->root_key.objectid;
1461
1462         inode_item = &log_root->root_item.inode;
1463         btrfs_set_stack_inode_generation(inode_item, 1);
1464         btrfs_set_stack_inode_size(inode_item, 3);
1465         btrfs_set_stack_inode_nlink(inode_item, 1);
1466         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
1467         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1468
1469         btrfs_set_root_node(&log_root->root_item, log_root->node);
1470
1471         WARN_ON(root->log_root);
1472         root->log_root = log_root;
1473         root->log_transid = 0;
1474         root->log_transid_committed = -1;
1475         root->last_log_commit = 0;
1476         return 0;
1477 }
1478
1479 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1480                                                struct btrfs_key *key)
1481 {
1482         struct btrfs_root *root;
1483         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1484         struct btrfs_path *path;
1485         u64 generation;
1486         int ret;
1487
1488         path = btrfs_alloc_path();
1489         if (!path)
1490                 return ERR_PTR(-ENOMEM);
1491
1492         root = btrfs_alloc_root(fs_info);
1493         if (!root) {
1494                 ret = -ENOMEM;
1495                 goto alloc_fail;
1496         }
1497
1498         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1499                 tree_root->stripesize, root, fs_info, key->objectid);
1500
1501         ret = btrfs_find_root(tree_root, key, path,
1502                               &root->root_item, &root->root_key);
1503         if (ret) {
1504                 if (ret > 0)
1505                         ret = -ENOENT;
1506                 goto find_fail;
1507         }
1508
1509         generation = btrfs_root_generation(&root->root_item);
1510         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1511                                      generation);
1512         if (IS_ERR(root->node)) {
1513                 ret = PTR_ERR(root->node);
1514                 goto find_fail;
1515         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1516                 ret = -EIO;
1517                 free_extent_buffer(root->node);
1518                 goto find_fail;
1519         }
1520         root->commit_root = btrfs_root_node(root);
1521 out:
1522         btrfs_free_path(path);
1523         return root;
1524
1525 find_fail:
1526         kfree(root);
1527 alloc_fail:
1528         root = ERR_PTR(ret);
1529         goto out;
1530 }
1531
1532 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1533                                       struct btrfs_key *location)
1534 {
1535         struct btrfs_root *root;
1536
1537         root = btrfs_read_tree_root(tree_root, location);
1538         if (IS_ERR(root))
1539                 return root;
1540
1541         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1542                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1543                 btrfs_check_and_init_root_item(&root->root_item);
1544         }
1545
1546         return root;
1547 }
1548
1549 int btrfs_init_fs_root(struct btrfs_root *root)
1550 {
1551         int ret;
1552         struct btrfs_subvolume_writers *writers;
1553
1554         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1555         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1556                                         GFP_NOFS);
1557         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1558                 ret = -ENOMEM;
1559                 goto fail;
1560         }
1561
1562         writers = btrfs_alloc_subvolume_writers();
1563         if (IS_ERR(writers)) {
1564                 ret = PTR_ERR(writers);
1565                 goto fail;
1566         }
1567         root->subv_writers = writers;
1568
1569         btrfs_init_free_ino_ctl(root);
1570         spin_lock_init(&root->ino_cache_lock);
1571         init_waitqueue_head(&root->ino_cache_wait);
1572
1573         ret = get_anon_bdev(&root->anon_dev);
1574         if (ret)
1575                 goto free_writers;
1576         return 0;
1577
1578 free_writers:
1579         btrfs_free_subvolume_writers(root->subv_writers);
1580 fail:
1581         kfree(root->free_ino_ctl);
1582         kfree(root->free_ino_pinned);
1583         return ret;
1584 }
1585
1586 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1587                                                u64 root_id)
1588 {
1589         struct btrfs_root *root;
1590
1591         spin_lock(&fs_info->fs_roots_radix_lock);
1592         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1593                                  (unsigned long)root_id);
1594         spin_unlock(&fs_info->fs_roots_radix_lock);
1595         return root;
1596 }
1597
1598 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1599                          struct btrfs_root *root)
1600 {
1601         int ret;
1602
1603         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1604         if (ret)
1605                 return ret;
1606
1607         spin_lock(&fs_info->fs_roots_radix_lock);
1608         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1609                                 (unsigned long)root->root_key.objectid,
1610                                 root);
1611         if (ret == 0)
1612                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1613         spin_unlock(&fs_info->fs_roots_radix_lock);
1614         radix_tree_preload_end();
1615
1616         return ret;
1617 }
1618
1619 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1620                                      struct btrfs_key *location,
1621                                      bool check_ref)
1622 {
1623         struct btrfs_root *root;
1624         struct btrfs_path *path;
1625         struct btrfs_key key;
1626         int ret;
1627
1628         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1629                 return fs_info->tree_root;
1630         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1631                 return fs_info->extent_root;
1632         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1633                 return fs_info->chunk_root;
1634         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1635                 return fs_info->dev_root;
1636         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1637                 return fs_info->csum_root;
1638         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1639                 return fs_info->quota_root ? fs_info->quota_root :
1640                                              ERR_PTR(-ENOENT);
1641         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1642                 return fs_info->uuid_root ? fs_info->uuid_root :
1643                                             ERR_PTR(-ENOENT);
1644 again:
1645         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1646         if (root) {
1647                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1648                         return ERR_PTR(-ENOENT);
1649                 return root;
1650         }
1651
1652         root = btrfs_read_fs_root(fs_info->tree_root, location);
1653         if (IS_ERR(root))
1654                 return root;
1655
1656         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1657                 ret = -ENOENT;
1658                 goto fail;
1659         }
1660
1661         ret = btrfs_init_fs_root(root);
1662         if (ret)
1663                 goto fail;
1664
1665         path = btrfs_alloc_path();
1666         if (!path) {
1667                 ret = -ENOMEM;
1668                 goto fail;
1669         }
1670         key.objectid = BTRFS_ORPHAN_OBJECTID;
1671         key.type = BTRFS_ORPHAN_ITEM_KEY;
1672         key.offset = location->objectid;
1673
1674         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1675         btrfs_free_path(path);
1676         if (ret < 0)
1677                 goto fail;
1678         if (ret == 0)
1679                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1680
1681         ret = btrfs_insert_fs_root(fs_info, root);
1682         if (ret) {
1683                 if (ret == -EEXIST) {
1684                         free_fs_root(root);
1685                         goto again;
1686                 }
1687                 goto fail;
1688         }
1689         return root;
1690 fail:
1691         free_fs_root(root);
1692         return ERR_PTR(ret);
1693 }
1694
1695 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1696 {
1697         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1698         int ret = 0;
1699         struct btrfs_device *device;
1700         struct backing_dev_info *bdi;
1701
1702         rcu_read_lock();
1703         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1704                 if (!device->bdev)
1705                         continue;
1706                 bdi = blk_get_backing_dev_info(device->bdev);
1707                 if (bdi_congested(bdi, bdi_bits)) {
1708                         ret = 1;
1709                         break;
1710                 }
1711         }
1712         rcu_read_unlock();
1713         return ret;
1714 }
1715
1716 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1717 {
1718         int err;
1719
1720         err = bdi_setup_and_register(bdi, "btrfs");
1721         if (err)
1722                 return err;
1723
1724         bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
1725         bdi->congested_fn       = btrfs_congested_fn;
1726         bdi->congested_data     = info;
1727         return 0;
1728 }
1729
1730 /*
1731  * called by the kthread helper functions to finally call the bio end_io
1732  * functions.  This is where read checksum verification actually happens
1733  */
1734 static void end_workqueue_fn(struct btrfs_work *work)
1735 {
1736         struct bio *bio;
1737         struct btrfs_end_io_wq *end_io_wq;
1738         int error;
1739
1740         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1741         bio = end_io_wq->bio;
1742
1743         error = end_io_wq->error;
1744         bio->bi_private = end_io_wq->private;
1745         bio->bi_end_io = end_io_wq->end_io;
1746         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1747         bio_endio(bio, error);
1748 }
1749
1750 static int cleaner_kthread(void *arg)
1751 {
1752         struct btrfs_root *root = arg;
1753         int again;
1754
1755         do {
1756                 again = 0;
1757
1758                 /* Make the cleaner go to sleep early. */
1759                 if (btrfs_need_cleaner_sleep(root))
1760                         goto sleep;
1761
1762                 if (!mutex_trylock(&root->fs_info->cleaner_mutex))
1763                         goto sleep;
1764
1765                 /*
1766                  * Avoid the problem that we change the status of the fs
1767                  * during the above check and trylock.
1768                  */
1769                 if (btrfs_need_cleaner_sleep(root)) {
1770                         mutex_unlock(&root->fs_info->cleaner_mutex);
1771                         goto sleep;
1772                 }
1773
1774                 btrfs_run_delayed_iputs(root);
1775                 btrfs_delete_unused_bgs(root->fs_info);
1776                 again = btrfs_clean_one_deleted_snapshot(root);
1777                 mutex_unlock(&root->fs_info->cleaner_mutex);
1778
1779                 /*
1780                  * The defragger has dealt with the R/O remount and umount,
1781                  * needn't do anything special here.
1782                  */
1783                 btrfs_run_defrag_inodes(root->fs_info);
1784 sleep:
1785                 if (!try_to_freeze() && !again) {
1786                         set_current_state(TASK_INTERRUPTIBLE);
1787                         if (!kthread_should_stop())
1788                                 schedule();
1789                         __set_current_state(TASK_RUNNING);
1790                 }
1791         } while (!kthread_should_stop());
1792         return 0;
1793 }
1794
1795 static int transaction_kthread(void *arg)
1796 {
1797         struct btrfs_root *root = arg;
1798         struct btrfs_trans_handle *trans;
1799         struct btrfs_transaction *cur;
1800         u64 transid;
1801         unsigned long now;
1802         unsigned long delay;
1803         bool cannot_commit;
1804
1805         do {
1806                 cannot_commit = false;
1807                 delay = HZ * root->fs_info->commit_interval;
1808                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1809
1810                 spin_lock(&root->fs_info->trans_lock);
1811                 cur = root->fs_info->running_transaction;
1812                 if (!cur) {
1813                         spin_unlock(&root->fs_info->trans_lock);
1814                         goto sleep;
1815                 }
1816
1817                 now = get_seconds();
1818                 if (cur->state < TRANS_STATE_BLOCKED &&
1819                     (now < cur->start_time ||
1820                      now - cur->start_time < root->fs_info->commit_interval)) {
1821                         spin_unlock(&root->fs_info->trans_lock);
1822                         delay = HZ * 5;
1823                         goto sleep;
1824                 }
1825                 transid = cur->transid;
1826                 spin_unlock(&root->fs_info->trans_lock);
1827
1828                 /* If the file system is aborted, this will always fail. */
1829                 trans = btrfs_attach_transaction(root);
1830                 if (IS_ERR(trans)) {
1831                         if (PTR_ERR(trans) != -ENOENT)
1832                                 cannot_commit = true;
1833                         goto sleep;
1834                 }
1835                 if (transid == trans->transid) {
1836                         btrfs_commit_transaction(trans, root);
1837                 } else {
1838                         btrfs_end_transaction(trans, root);
1839                 }
1840 sleep:
1841                 wake_up_process(root->fs_info->cleaner_kthread);
1842                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1843
1844                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1845                                       &root->fs_info->fs_state)))
1846                         btrfs_cleanup_transaction(root);
1847                 if (!try_to_freeze()) {
1848                         set_current_state(TASK_INTERRUPTIBLE);
1849                         if (!kthread_should_stop() &&
1850                             (!btrfs_transaction_blocked(root->fs_info) ||
1851                              cannot_commit))
1852                                 schedule_timeout(delay);
1853                         __set_current_state(TASK_RUNNING);
1854                 }
1855         } while (!kthread_should_stop());
1856         return 0;
1857 }
1858
1859 /*
1860  * this will find the highest generation in the array of
1861  * root backups.  The index of the highest array is returned,
1862  * or -1 if we can't find anything.
1863  *
1864  * We check to make sure the array is valid by comparing the
1865  * generation of the latest  root in the array with the generation
1866  * in the super block.  If they don't match we pitch it.
1867  */
1868 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1869 {
1870         u64 cur;
1871         int newest_index = -1;
1872         struct btrfs_root_backup *root_backup;
1873         int i;
1874
1875         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1876                 root_backup = info->super_copy->super_roots + i;
1877                 cur = btrfs_backup_tree_root_gen(root_backup);
1878                 if (cur == newest_gen)
1879                         newest_index = i;
1880         }
1881
1882         /* check to see if we actually wrapped around */
1883         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1884                 root_backup = info->super_copy->super_roots;
1885                 cur = btrfs_backup_tree_root_gen(root_backup);
1886                 if (cur == newest_gen)
1887                         newest_index = 0;
1888         }
1889         return newest_index;
1890 }
1891
1892
1893 /*
1894  * find the oldest backup so we know where to store new entries
1895  * in the backup array.  This will set the backup_root_index
1896  * field in the fs_info struct
1897  */
1898 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1899                                      u64 newest_gen)
1900 {
1901         int newest_index = -1;
1902
1903         newest_index = find_newest_super_backup(info, newest_gen);
1904         /* if there was garbage in there, just move along */
1905         if (newest_index == -1) {
1906                 info->backup_root_index = 0;
1907         } else {
1908                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1909         }
1910 }
1911
1912 /*
1913  * copy all the root pointers into the super backup array.
1914  * this will bump the backup pointer by one when it is
1915  * done
1916  */
1917 static void backup_super_roots(struct btrfs_fs_info *info)
1918 {
1919         int next_backup;
1920         struct btrfs_root_backup *root_backup;
1921         int last_backup;
1922
1923         next_backup = info->backup_root_index;
1924         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1925                 BTRFS_NUM_BACKUP_ROOTS;
1926
1927         /*
1928          * just overwrite the last backup if we're at the same generation
1929          * this happens only at umount
1930          */
1931         root_backup = info->super_for_commit->super_roots + last_backup;
1932         if (btrfs_backup_tree_root_gen(root_backup) ==
1933             btrfs_header_generation(info->tree_root->node))
1934                 next_backup = last_backup;
1935
1936         root_backup = info->super_for_commit->super_roots + next_backup;
1937
1938         /*
1939          * make sure all of our padding and empty slots get zero filled
1940          * regardless of which ones we use today
1941          */
1942         memset(root_backup, 0, sizeof(*root_backup));
1943
1944         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1945
1946         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1947         btrfs_set_backup_tree_root_gen(root_backup,
1948                                btrfs_header_generation(info->tree_root->node));
1949
1950         btrfs_set_backup_tree_root_level(root_backup,
1951                                btrfs_header_level(info->tree_root->node));
1952
1953         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1954         btrfs_set_backup_chunk_root_gen(root_backup,
1955                                btrfs_header_generation(info->chunk_root->node));
1956         btrfs_set_backup_chunk_root_level(root_backup,
1957                                btrfs_header_level(info->chunk_root->node));
1958
1959         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1960         btrfs_set_backup_extent_root_gen(root_backup,
1961                                btrfs_header_generation(info->extent_root->node));
1962         btrfs_set_backup_extent_root_level(root_backup,
1963                                btrfs_header_level(info->extent_root->node));
1964
1965         /*
1966          * we might commit during log recovery, which happens before we set
1967          * the fs_root.  Make sure it is valid before we fill it in.
1968          */
1969         if (info->fs_root && info->fs_root->node) {
1970                 btrfs_set_backup_fs_root(root_backup,
1971                                          info->fs_root->node->start);
1972                 btrfs_set_backup_fs_root_gen(root_backup,
1973                                btrfs_header_generation(info->fs_root->node));
1974                 btrfs_set_backup_fs_root_level(root_backup,
1975                                btrfs_header_level(info->fs_root->node));
1976         }
1977
1978         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1979         btrfs_set_backup_dev_root_gen(root_backup,
1980                                btrfs_header_generation(info->dev_root->node));
1981         btrfs_set_backup_dev_root_level(root_backup,
1982                                        btrfs_header_level(info->dev_root->node));
1983
1984         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1985         btrfs_set_backup_csum_root_gen(root_backup,
1986                                btrfs_header_generation(info->csum_root->node));
1987         btrfs_set_backup_csum_root_level(root_backup,
1988                                btrfs_header_level(info->csum_root->node));
1989
1990         btrfs_set_backup_total_bytes(root_backup,
1991                              btrfs_super_total_bytes(info->super_copy));
1992         btrfs_set_backup_bytes_used(root_backup,
1993                              btrfs_super_bytes_used(info->super_copy));
1994         btrfs_set_backup_num_devices(root_backup,
1995                              btrfs_super_num_devices(info->super_copy));
1996
1997         /*
1998          * if we don't copy this out to the super_copy, it won't get remembered
1999          * for the next commit
2000          */
2001         memcpy(&info->super_copy->super_roots,
2002                &info->super_for_commit->super_roots,
2003                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2004 }
2005
2006 /*
2007  * this copies info out of the root backup array and back into
2008  * the in-memory super block.  It is meant to help iterate through
2009  * the array, so you send it the number of backups you've already
2010  * tried and the last backup index you used.
2011  *
2012  * this returns -1 when it has tried all the backups
2013  */
2014 static noinline int next_root_backup(struct btrfs_fs_info *info,
2015                                      struct btrfs_super_block *super,
2016                                      int *num_backups_tried, int *backup_index)
2017 {
2018         struct btrfs_root_backup *root_backup;
2019         int newest = *backup_index;
2020
2021         if (*num_backups_tried == 0) {
2022                 u64 gen = btrfs_super_generation(super);
2023
2024                 newest = find_newest_super_backup(info, gen);
2025                 if (newest == -1)
2026                         return -1;
2027
2028                 *backup_index = newest;
2029                 *num_backups_tried = 1;
2030         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2031                 /* we've tried all the backups, all done */
2032                 return -1;
2033         } else {
2034                 /* jump to the next oldest backup */
2035                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2036                         BTRFS_NUM_BACKUP_ROOTS;
2037                 *backup_index = newest;
2038                 *num_backups_tried += 1;
2039         }
2040         root_backup = super->super_roots + newest;
2041
2042         btrfs_set_super_generation(super,
2043                                    btrfs_backup_tree_root_gen(root_backup));
2044         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2045         btrfs_set_super_root_level(super,
2046                                    btrfs_backup_tree_root_level(root_backup));
2047         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2048
2049         /*
2050          * fixme: the total bytes and num_devices need to match or we should
2051          * need a fsck
2052          */
2053         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2054         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2055         return 0;
2056 }
2057
2058 /* helper to cleanup workers */
2059 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2060 {
2061         btrfs_destroy_workqueue(fs_info->fixup_workers);
2062         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2063         btrfs_destroy_workqueue(fs_info->workers);
2064         btrfs_destroy_workqueue(fs_info->endio_workers);
2065         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2066         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2067         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2068         btrfs_destroy_workqueue(fs_info->rmw_workers);
2069         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2070         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2071         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2072         btrfs_destroy_workqueue(fs_info->submit_workers);
2073         btrfs_destroy_workqueue(fs_info->delayed_workers);
2074         btrfs_destroy_workqueue(fs_info->caching_workers);
2075         btrfs_destroy_workqueue(fs_info->readahead_workers);
2076         btrfs_destroy_workqueue(fs_info->flush_workers);
2077         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2078         btrfs_destroy_workqueue(fs_info->extent_workers);
2079 }
2080
2081 static void free_root_extent_buffers(struct btrfs_root *root)
2082 {
2083         if (root) {
2084                 free_extent_buffer(root->node);
2085                 free_extent_buffer(root->commit_root);
2086                 root->node = NULL;
2087                 root->commit_root = NULL;
2088         }
2089 }
2090
2091 /* helper to cleanup tree roots */
2092 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2093 {
2094         free_root_extent_buffers(info->tree_root);
2095
2096         free_root_extent_buffers(info->dev_root);
2097         free_root_extent_buffers(info->extent_root);
2098         free_root_extent_buffers(info->csum_root);
2099         free_root_extent_buffers(info->quota_root);
2100         free_root_extent_buffers(info->uuid_root);
2101         if (chunk_root)
2102                 free_root_extent_buffers(info->chunk_root);
2103 }
2104
2105 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2106 {
2107         int ret;
2108         struct btrfs_root *gang[8];
2109         int i;
2110
2111         while (!list_empty(&fs_info->dead_roots)) {
2112                 gang[0] = list_entry(fs_info->dead_roots.next,
2113                                      struct btrfs_root, root_list);
2114                 list_del(&gang[0]->root_list);
2115
2116                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2117                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2118                 } else {
2119                         free_extent_buffer(gang[0]->node);
2120                         free_extent_buffer(gang[0]->commit_root);
2121                         btrfs_put_fs_root(gang[0]);
2122                 }
2123         }
2124
2125         while (1) {
2126                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2127                                              (void **)gang, 0,
2128                                              ARRAY_SIZE(gang));
2129                 if (!ret)
2130                         break;
2131                 for (i = 0; i < ret; i++)
2132                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2133         }
2134
2135         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2136                 btrfs_free_log_root_tree(NULL, fs_info);
2137                 btrfs_destroy_pinned_extent(fs_info->tree_root,
2138                                             fs_info->pinned_extents);
2139         }
2140 }
2141
2142 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2143 {
2144         mutex_init(&fs_info->scrub_lock);
2145         atomic_set(&fs_info->scrubs_running, 0);
2146         atomic_set(&fs_info->scrub_pause_req, 0);
2147         atomic_set(&fs_info->scrubs_paused, 0);
2148         atomic_set(&fs_info->scrub_cancel_req, 0);
2149         init_waitqueue_head(&fs_info->scrub_pause_wait);
2150         fs_info->scrub_workers_refcnt = 0;
2151 }
2152
2153 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2154 {
2155         spin_lock_init(&fs_info->balance_lock);
2156         mutex_init(&fs_info->balance_mutex);
2157         atomic_set(&fs_info->balance_running, 0);
2158         atomic_set(&fs_info->balance_pause_req, 0);
2159         atomic_set(&fs_info->balance_cancel_req, 0);
2160         fs_info->balance_ctl = NULL;
2161         init_waitqueue_head(&fs_info->balance_wait_q);
2162 }
2163
2164 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info,
2165                                    struct btrfs_root *tree_root)
2166 {
2167         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2168         set_nlink(fs_info->btree_inode, 1);
2169         /*
2170          * we set the i_size on the btree inode to the max possible int.
2171          * the real end of the address space is determined by all of
2172          * the devices in the system
2173          */
2174         fs_info->btree_inode->i_size = OFFSET_MAX;
2175         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2176
2177         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2178         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2179                              fs_info->btree_inode->i_mapping);
2180         BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2181         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2182
2183         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2184
2185         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2186         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2187                sizeof(struct btrfs_key));
2188         set_bit(BTRFS_INODE_DUMMY,
2189                 &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2190         btrfs_insert_inode_hash(fs_info->btree_inode);
2191 }
2192
2193 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2194 {
2195         fs_info->dev_replace.lock_owner = 0;
2196         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2197         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2198         mutex_init(&fs_info->dev_replace.lock_management_lock);
2199         mutex_init(&fs_info->dev_replace.lock);
2200         init_waitqueue_head(&fs_info->replace_wait);
2201 }
2202
2203 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2204 {
2205         spin_lock_init(&fs_info->qgroup_lock);
2206         mutex_init(&fs_info->qgroup_ioctl_lock);
2207         fs_info->qgroup_tree = RB_ROOT;
2208         fs_info->qgroup_op_tree = RB_ROOT;
2209         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2210         fs_info->qgroup_seq = 1;
2211         fs_info->quota_enabled = 0;
2212         fs_info->pending_quota_state = 0;
2213         fs_info->qgroup_ulist = NULL;
2214         mutex_init(&fs_info->qgroup_rescan_lock);
2215 }
2216
2217 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2218                 struct btrfs_fs_devices *fs_devices)
2219 {
2220         int max_active = fs_info->thread_pool_size;
2221         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2222
2223         fs_info->workers =
2224                 btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
2225                                       max_active, 16);
2226
2227         fs_info->delalloc_workers =
2228                 btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
2229
2230         fs_info->flush_workers =
2231                 btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
2232
2233         fs_info->caching_workers =
2234                 btrfs_alloc_workqueue("cache", flags, max_active, 0);
2235
2236         /*
2237          * a higher idle thresh on the submit workers makes it much more
2238          * likely that bios will be send down in a sane order to the
2239          * devices
2240          */
2241         fs_info->submit_workers =
2242                 btrfs_alloc_workqueue("submit", flags,
2243                                       min_t(u64, fs_devices->num_devices,
2244                                             max_active), 64);
2245
2246         fs_info->fixup_workers =
2247                 btrfs_alloc_workqueue("fixup", flags, 1, 0);
2248
2249         /*
2250          * endios are largely parallel and should have a very
2251          * low idle thresh
2252          */
2253         fs_info->endio_workers =
2254                 btrfs_alloc_workqueue("endio", flags, max_active, 4);
2255         fs_info->endio_meta_workers =
2256                 btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
2257         fs_info->endio_meta_write_workers =
2258                 btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
2259         fs_info->endio_raid56_workers =
2260                 btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
2261         fs_info->endio_repair_workers =
2262                 btrfs_alloc_workqueue("endio-repair", flags, 1, 0);
2263         fs_info->rmw_workers =
2264                 btrfs_alloc_workqueue("rmw", flags, max_active, 2);
2265         fs_info->endio_write_workers =
2266                 btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
2267         fs_info->endio_freespace_worker =
2268                 btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
2269         fs_info->delayed_workers =
2270                 btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
2271         fs_info->readahead_workers =
2272                 btrfs_alloc_workqueue("readahead", flags, max_active, 2);
2273         fs_info->qgroup_rescan_workers =
2274                 btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
2275         fs_info->extent_workers =
2276                 btrfs_alloc_workqueue("extent-refs", flags,
2277                                       min_t(u64, fs_devices->num_devices,
2278                                             max_active), 8);
2279
2280         if (!(fs_info->workers && fs_info->delalloc_workers &&
2281               fs_info->submit_workers && fs_info->flush_workers &&
2282               fs_info->endio_workers && fs_info->endio_meta_workers &&
2283               fs_info->endio_meta_write_workers &&
2284               fs_info->endio_repair_workers &&
2285               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2286               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2287               fs_info->caching_workers && fs_info->readahead_workers &&
2288               fs_info->fixup_workers && fs_info->delayed_workers &&
2289               fs_info->extent_workers &&
2290               fs_info->qgroup_rescan_workers)) {
2291                 return -ENOMEM;
2292         }
2293
2294         return 0;
2295 }
2296
2297 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2298                             struct btrfs_fs_devices *fs_devices)
2299 {
2300         int ret;
2301         struct btrfs_root *tree_root = fs_info->tree_root;
2302         struct btrfs_root *log_tree_root;
2303         struct btrfs_super_block *disk_super = fs_info->super_copy;
2304         u64 bytenr = btrfs_super_log_root(disk_super);
2305
2306         if (fs_devices->rw_devices == 0) {
2307                 printk(KERN_WARNING "BTRFS: log replay required "
2308                        "on RO media\n");
2309                 return -EIO;
2310         }
2311
2312         log_tree_root = btrfs_alloc_root(fs_info);
2313         if (!log_tree_root)
2314                 return -ENOMEM;
2315
2316         __setup_root(tree_root->nodesize, tree_root->sectorsize,
2317                         tree_root->stripesize, log_tree_root, fs_info,
2318                         BTRFS_TREE_LOG_OBJECTID);
2319
2320         log_tree_root->node = read_tree_block(tree_root, bytenr,
2321                         fs_info->generation + 1);
2322         if (IS_ERR(log_tree_root->node)) {
2323                 printk(KERN_ERR "BTRFS: failed to read log tree\n");
2324                 ret = PTR_ERR(log_tree_root->node);
2325                 kfree(log_tree_root);
2326                 return ret;
2327         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2328                 printk(KERN_ERR "BTRFS: failed to read log tree\n");
2329                 free_extent_buffer(log_tree_root->node);
2330                 kfree(log_tree_root);
2331                 return -EIO;
2332         }
2333         /* returns with log_tree_root freed on success */
2334         ret = btrfs_recover_log_trees(log_tree_root);
2335         if (ret) {
2336                 btrfs_error(tree_root->fs_info, ret,
2337                             "Failed to recover log tree");
2338                 free_extent_buffer(log_tree_root->node);
2339                 kfree(log_tree_root);
2340                 return ret;
2341         }
2342
2343         if (fs_info->sb->s_flags & MS_RDONLY) {
2344                 ret = btrfs_commit_super(tree_root);
2345                 if (ret)
2346                         return ret;
2347         }
2348
2349         return 0;
2350 }
2351
2352 static int btrfs_read_roots(struct btrfs_fs_info *fs_info,
2353                             struct btrfs_root *tree_root)
2354 {
2355         struct btrfs_root *root;
2356         struct btrfs_key location;
2357         int ret;
2358
2359         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2360         location.type = BTRFS_ROOT_ITEM_KEY;
2361         location.offset = 0;
2362
2363         root = btrfs_read_tree_root(tree_root, &location);
2364         if (IS_ERR(root))
2365                 return PTR_ERR(root);
2366         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2367         fs_info->extent_root = root;
2368
2369         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2370         root = btrfs_read_tree_root(tree_root, &location);
2371         if (IS_ERR(root))
2372                 return PTR_ERR(root);
2373         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2374         fs_info->dev_root = root;
2375         btrfs_init_devices_late(fs_info);
2376
2377         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2378         root = btrfs_read_tree_root(tree_root, &location);
2379         if (IS_ERR(root))
2380                 return PTR_ERR(root);
2381         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2382         fs_info->csum_root = root;
2383
2384         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2385         root = btrfs_read_tree_root(tree_root, &location);
2386         if (!IS_ERR(root)) {
2387                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2388                 fs_info->quota_enabled = 1;
2389                 fs_info->pending_quota_state = 1;
2390                 fs_info->quota_root = root;
2391         }
2392
2393         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2394         root = btrfs_read_tree_root(tree_root, &location);
2395         if (IS_ERR(root)) {
2396                 ret = PTR_ERR(root);
2397                 if (ret != -ENOENT)
2398                         return ret;
2399         } else {
2400                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2401                 fs_info->uuid_root = root;
2402         }
2403
2404         return 0;
2405 }
2406
2407 int open_ctree(struct super_block *sb,
2408                struct btrfs_fs_devices *fs_devices,
2409                char *options)
2410 {
2411         u32 sectorsize;
2412         u32 nodesize;
2413         u32 stripesize;
2414         u64 generation;
2415         u64 features;
2416         struct btrfs_key location;
2417         struct buffer_head *bh;
2418         struct btrfs_super_block *disk_super;
2419         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2420         struct btrfs_root *tree_root;
2421         struct btrfs_root *chunk_root;
2422         int ret;
2423         int err = -EINVAL;
2424         int num_backups_tried = 0;
2425         int backup_index = 0;
2426         int max_active;
2427
2428         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
2429         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
2430         if (!tree_root || !chunk_root) {
2431                 err = -ENOMEM;
2432                 goto fail;
2433         }
2434
2435         ret = init_srcu_struct(&fs_info->subvol_srcu);
2436         if (ret) {
2437                 err = ret;
2438                 goto fail;
2439         }
2440
2441         ret = setup_bdi(fs_info, &fs_info->bdi);
2442         if (ret) {
2443                 err = ret;
2444                 goto fail_srcu;
2445         }
2446
2447         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2448         if (ret) {
2449                 err = ret;
2450                 goto fail_bdi;
2451         }
2452         fs_info->dirty_metadata_batch = PAGE_CACHE_SIZE *
2453                                         (1 + ilog2(nr_cpu_ids));
2454
2455         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2456         if (ret) {
2457                 err = ret;
2458                 goto fail_dirty_metadata_bytes;
2459         }
2460
2461         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2462         if (ret) {
2463                 err = ret;
2464                 goto fail_delalloc_bytes;
2465         }
2466
2467         fs_info->btree_inode = new_inode(sb);
2468         if (!fs_info->btree_inode) {
2469                 err = -ENOMEM;
2470                 goto fail_bio_counter;
2471         }
2472
2473         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2474
2475         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2476         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2477         INIT_LIST_HEAD(&fs_info->trans_list);
2478         INIT_LIST_HEAD(&fs_info->dead_roots);
2479         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2480         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2481         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2482         spin_lock_init(&fs_info->delalloc_root_lock);
2483         spin_lock_init(&fs_info->trans_lock);
2484         spin_lock_init(&fs_info->fs_roots_radix_lock);
2485         spin_lock_init(&fs_info->delayed_iput_lock);
2486         spin_lock_init(&fs_info->defrag_inodes_lock);
2487         spin_lock_init(&fs_info->free_chunk_lock);
2488         spin_lock_init(&fs_info->tree_mod_seq_lock);
2489         spin_lock_init(&fs_info->super_lock);
2490         spin_lock_init(&fs_info->qgroup_op_lock);
2491         spin_lock_init(&fs_info->buffer_lock);
2492         spin_lock_init(&fs_info->unused_bgs_lock);
2493         rwlock_init(&fs_info->tree_mod_log_lock);
2494         mutex_init(&fs_info->unused_bg_unpin_mutex);
2495         mutex_init(&fs_info->reloc_mutex);
2496         mutex_init(&fs_info->delalloc_root_mutex);
2497         seqlock_init(&fs_info->profiles_lock);
2498         init_rwsem(&fs_info->delayed_iput_sem);
2499
2500         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2501         INIT_LIST_HEAD(&fs_info->space_info);
2502         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2503         INIT_LIST_HEAD(&fs_info->unused_bgs);
2504         btrfs_mapping_init(&fs_info->mapping_tree);
2505         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2506                              BTRFS_BLOCK_RSV_GLOBAL);
2507         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2508                              BTRFS_BLOCK_RSV_DELALLOC);
2509         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2510         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2511         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2512         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2513                              BTRFS_BLOCK_RSV_DELOPS);
2514         atomic_set(&fs_info->nr_async_submits, 0);
2515         atomic_set(&fs_info->async_delalloc_pages, 0);
2516         atomic_set(&fs_info->async_submit_draining, 0);
2517         atomic_set(&fs_info->nr_async_bios, 0);
2518         atomic_set(&fs_info->defrag_running, 0);
2519         atomic_set(&fs_info->qgroup_op_seq, 0);
2520         atomic64_set(&fs_info->tree_mod_seq, 0);
2521         fs_info->sb = sb;
2522         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2523         fs_info->metadata_ratio = 0;
2524         fs_info->defrag_inodes = RB_ROOT;
2525         fs_info->free_chunk_space = 0;
2526         fs_info->tree_mod_log = RB_ROOT;
2527         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2528         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2529         /* readahead state */
2530         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
2531         spin_lock_init(&fs_info->reada_lock);
2532
2533         fs_info->thread_pool_size = min_t(unsigned long,
2534                                           num_online_cpus() + 2, 8);
2535
2536         INIT_LIST_HEAD(&fs_info->ordered_roots);
2537         spin_lock_init(&fs_info->ordered_root_lock);
2538         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2539                                         GFP_NOFS);
2540         if (!fs_info->delayed_root) {
2541                 err = -ENOMEM;
2542                 goto fail_iput;
2543         }
2544         btrfs_init_delayed_root(fs_info->delayed_root);
2545
2546         btrfs_init_scrub(fs_info);
2547 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2548         fs_info->check_integrity_print_mask = 0;
2549 #endif
2550         btrfs_init_balance(fs_info);
2551         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2552
2553         sb->s_blocksize = 4096;
2554         sb->s_blocksize_bits = blksize_bits(4096);
2555         sb->s_bdi = &fs_info->bdi;
2556
2557         btrfs_init_btree_inode(fs_info, tree_root);
2558
2559         spin_lock_init(&fs_info->block_group_cache_lock);
2560         fs_info->block_group_cache_tree = RB_ROOT;
2561         fs_info->first_logical_byte = (u64)-1;
2562
2563         extent_io_tree_init(&fs_info->freed_extents[0],
2564                              fs_info->btree_inode->i_mapping);
2565         extent_io_tree_init(&fs_info->freed_extents[1],
2566                              fs_info->btree_inode->i_mapping);
2567         fs_info->pinned_extents = &fs_info->freed_extents[0];
2568         fs_info->do_barriers = 1;
2569
2570
2571         mutex_init(&fs_info->ordered_operations_mutex);
2572         mutex_init(&fs_info->ordered_extent_flush_mutex);
2573         mutex_init(&fs_info->tree_log_mutex);
2574         mutex_init(&fs_info->chunk_mutex);
2575         mutex_init(&fs_info->transaction_kthread_mutex);
2576         mutex_init(&fs_info->cleaner_mutex);
2577         mutex_init(&fs_info->volume_mutex);
2578         mutex_init(&fs_info->ro_block_group_mutex);
2579         init_rwsem(&fs_info->commit_root_sem);
2580         init_rwsem(&fs_info->cleanup_work_sem);
2581         init_rwsem(&fs_info->subvol_sem);
2582         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2583
2584         btrfs_init_dev_replace_locks(fs_info);
2585         btrfs_init_qgroup(fs_info);
2586
2587         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2588         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2589
2590         init_waitqueue_head(&fs_info->transaction_throttle);
2591         init_waitqueue_head(&fs_info->transaction_wait);
2592         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2593         init_waitqueue_head(&fs_info->async_submit_wait);
2594
2595         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2596
2597         ret = btrfs_alloc_stripe_hash_table(fs_info);
2598         if (ret) {
2599                 err = ret;
2600                 goto fail_alloc;
2601         }
2602
2603         __setup_root(4096, 4096, 4096, tree_root,
2604                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2605
2606         invalidate_bdev(fs_devices->latest_bdev);
2607
2608         /*
2609          * Read super block and check the signature bytes only
2610          */
2611         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2612         if (!bh) {
2613                 err = -EINVAL;
2614                 goto fail_alloc;
2615         }
2616
2617         /*
2618          * We want to check superblock checksum, the type is stored inside.
2619          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2620          */
2621         if (btrfs_check_super_csum(bh->b_data)) {
2622                 printk(KERN_ERR "BTRFS: superblock checksum mismatch\n");
2623                 err = -EINVAL;
2624                 goto fail_alloc;
2625         }
2626
2627         /*
2628          * super_copy is zeroed at allocation time and we never touch the
2629          * following bytes up to INFO_SIZE, the checksum is calculated from
2630          * the whole block of INFO_SIZE
2631          */
2632         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2633         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2634                sizeof(*fs_info->super_for_commit));
2635         brelse(bh);
2636
2637         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2638
2639         ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2640         if (ret) {
2641                 printk(KERN_ERR "BTRFS: superblock contains fatal errors\n");
2642                 err = -EINVAL;
2643                 goto fail_alloc;
2644         }
2645
2646         disk_super = fs_info->super_copy;
2647         if (!btrfs_super_root(disk_super))
2648                 goto fail_alloc;
2649
2650         /* check FS state, whether FS is broken. */
2651         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2652                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2653
2654         /*
2655          * run through our array of backup supers and setup
2656          * our ring pointer to the oldest one
2657          */
2658         generation = btrfs_super_generation(disk_super);
2659         find_oldest_super_backup(fs_info, generation);
2660
2661         /*
2662          * In the long term, we'll store the compression type in the super
2663          * block, and it'll be used for per file compression control.
2664          */
2665         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2666
2667         ret = btrfs_parse_options(tree_root, options);
2668         if (ret) {
2669                 err = ret;
2670                 goto fail_alloc;
2671         }
2672
2673         features = btrfs_super_incompat_flags(disk_super) &
2674                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2675         if (features) {
2676                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2677                        "unsupported optional features (%Lx).\n",
2678                        features);
2679                 err = -EINVAL;
2680                 goto fail_alloc;
2681         }
2682
2683         /*
2684          * Leafsize and nodesize were always equal, this is only a sanity check.
2685          */
2686         if (le32_to_cpu(disk_super->__unused_leafsize) !=
2687             btrfs_super_nodesize(disk_super)) {
2688                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2689                        "blocksizes don't match.  node %d leaf %d\n",
2690                        btrfs_super_nodesize(disk_super),
2691                        le32_to_cpu(disk_super->__unused_leafsize));
2692                 err = -EINVAL;
2693                 goto fail_alloc;
2694         }
2695         if (btrfs_super_nodesize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
2696                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2697                        "blocksize (%d) was too large\n",
2698                        btrfs_super_nodesize(disk_super));
2699                 err = -EINVAL;
2700                 goto fail_alloc;
2701         }
2702
2703         features = btrfs_super_incompat_flags(disk_super);
2704         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2705         if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2706                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2707
2708         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2709                 printk(KERN_INFO "BTRFS: has skinny extents\n");
2710
2711         /*
2712          * flag our filesystem as having big metadata blocks if
2713          * they are bigger than the page size
2714          */
2715         if (btrfs_super_nodesize(disk_super) > PAGE_CACHE_SIZE) {
2716                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2717                         printk(KERN_INFO "BTRFS: flagging fs with big metadata feature\n");
2718                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2719         }
2720
2721         nodesize = btrfs_super_nodesize(disk_super);
2722         sectorsize = btrfs_super_sectorsize(disk_super);
2723         stripesize = btrfs_super_stripesize(disk_super);
2724         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2725         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2726
2727         /*
2728          * mixed block groups end up with duplicate but slightly offset
2729          * extent buffers for the same range.  It leads to corruptions
2730          */
2731         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2732             (sectorsize != nodesize)) {
2733                 printk(KERN_ERR "BTRFS: unequal leaf/node/sector sizes "
2734                                 "are not allowed for mixed block groups on %s\n",
2735                                 sb->s_id);
2736                 goto fail_alloc;
2737         }
2738
2739         /*
2740          * Needn't use the lock because there is no other task which will
2741          * update the flag.
2742          */
2743         btrfs_set_super_incompat_flags(disk_super, features);
2744
2745         features = btrfs_super_compat_ro_flags(disk_super) &
2746                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2747         if (!(sb->s_flags & MS_RDONLY) && features) {
2748                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2749                        "unsupported option features (%Lx).\n",
2750                        features);
2751                 err = -EINVAL;
2752                 goto fail_alloc;
2753         }
2754
2755         max_active = fs_info->thread_pool_size;
2756
2757         ret = btrfs_init_workqueues(fs_info, fs_devices);
2758         if (ret) {
2759                 err = ret;
2760                 goto fail_sb_buffer;
2761         }
2762
2763         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2764         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2765                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2766
2767         tree_root->nodesize = nodesize;
2768         tree_root->sectorsize = sectorsize;
2769         tree_root->stripesize = stripesize;
2770
2771         sb->s_blocksize = sectorsize;
2772         sb->s_blocksize_bits = blksize_bits(sectorsize);
2773
2774         if (btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
2775                 printk(KERN_ERR "BTRFS: valid FS not found on %s\n", sb->s_id);
2776                 goto fail_sb_buffer;
2777         }
2778
2779         if (sectorsize != PAGE_SIZE) {
2780                 printk(KERN_ERR "BTRFS: incompatible sector size (%lu) "
2781                        "found on %s\n", (unsigned long)sectorsize, sb->s_id);
2782                 goto fail_sb_buffer;
2783         }
2784
2785         mutex_lock(&fs_info->chunk_mutex);
2786         ret = btrfs_read_sys_array(tree_root);
2787         mutex_unlock(&fs_info->chunk_mutex);
2788         if (ret) {
2789                 printk(KERN_ERR "BTRFS: failed to read the system "
2790                        "array on %s\n", sb->s_id);
2791                 goto fail_sb_buffer;
2792         }
2793
2794         generation = btrfs_super_chunk_root_generation(disk_super);
2795
2796         __setup_root(nodesize, sectorsize, stripesize, chunk_root,
2797                      fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2798
2799         chunk_root->node = read_tree_block(chunk_root,
2800                                            btrfs_super_chunk_root(disk_super),
2801                                            generation);
2802         if (IS_ERR(chunk_root->node) ||
2803             !extent_buffer_uptodate(chunk_root->node)) {
2804                 printk(KERN_ERR "BTRFS: failed to read chunk root on %s\n",
2805                        sb->s_id);
2806                 goto fail_tree_roots;
2807         }
2808         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2809         chunk_root->commit_root = btrfs_root_node(chunk_root);
2810
2811         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2812            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2813
2814         ret = btrfs_read_chunk_tree(chunk_root);
2815         if (ret) {
2816                 printk(KERN_ERR "BTRFS: failed to read chunk tree on %s\n",
2817                        sb->s_id);
2818                 goto fail_tree_roots;
2819         }
2820
2821         /*
2822          * keep the device that is marked to be the target device for the
2823          * dev_replace procedure
2824          */
2825         btrfs_close_extra_devices(fs_devices, 0);
2826
2827         if (!fs_devices->latest_bdev) {
2828                 printk(KERN_ERR "BTRFS: failed to read devices on %s\n",
2829                        sb->s_id);
2830                 goto fail_tree_roots;
2831         }
2832
2833 retry_root_backup:
2834         generation = btrfs_super_generation(disk_super);
2835
2836         tree_root->node = read_tree_block(tree_root,
2837                                           btrfs_super_root(disk_super),
2838                                           generation);
2839         if (IS_ERR(tree_root->node) ||
2840             !extent_buffer_uptodate(tree_root->node)) {
2841                 printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
2842                        sb->s_id);
2843
2844                 goto recovery_tree_root;
2845         }
2846
2847         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2848         tree_root->commit_root = btrfs_root_node(tree_root);
2849         btrfs_set_root_refs(&tree_root->root_item, 1);
2850
2851         ret = btrfs_read_roots(fs_info, tree_root);
2852         if (ret)
2853                 goto recovery_tree_root;
2854
2855         fs_info->generation = generation;
2856         fs_info->last_trans_committed = generation;
2857
2858         ret = btrfs_recover_balance(fs_info);
2859         if (ret) {
2860                 printk(KERN_ERR "BTRFS: failed to recover balance\n");
2861                 goto fail_block_groups;
2862         }
2863
2864         ret = btrfs_init_dev_stats(fs_info);
2865         if (ret) {
2866                 printk(KERN_ERR "BTRFS: failed to init dev_stats: %d\n",
2867                        ret);
2868                 goto fail_block_groups;
2869         }
2870
2871         ret = btrfs_init_dev_replace(fs_info);
2872         if (ret) {
2873                 pr_err("BTRFS: failed to init dev_replace: %d\n", ret);
2874                 goto fail_block_groups;
2875         }
2876
2877         btrfs_close_extra_devices(fs_devices, 1);
2878
2879         ret = btrfs_sysfs_add_fsid(fs_devices, NULL);
2880         if (ret) {
2881                 pr_err("BTRFS: failed to init sysfs fsid interface: %d\n", ret);
2882                 goto fail_block_groups;
2883         }
2884
2885         ret = btrfs_sysfs_add_device(fs_devices);
2886         if (ret) {
2887                 pr_err("BTRFS: failed to init sysfs device interface: %d\n", ret);
2888                 goto fail_fsdev_sysfs;
2889         }
2890
2891         ret = btrfs_sysfs_add_one(fs_info);
2892         if (ret) {
2893                 pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
2894                 goto fail_fsdev_sysfs;
2895         }
2896
2897         ret = btrfs_init_space_info(fs_info);
2898         if (ret) {
2899                 printk(KERN_ERR "BTRFS: Failed to initial space info: %d\n", ret);
2900                 goto fail_sysfs;
2901         }
2902
2903         ret = btrfs_read_block_groups(fs_info->extent_root);
2904         if (ret) {
2905                 printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
2906                 goto fail_sysfs;
2907         }
2908         fs_info->num_tolerated_disk_barrier_failures =
2909                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2910         if (fs_info->fs_devices->missing_devices >
2911              fs_info->num_tolerated_disk_barrier_failures &&
2912             !(sb->s_flags & MS_RDONLY)) {
2913                 printk(KERN_WARNING "BTRFS: "
2914                         "too many missing devices, writeable mount is not allowed\n");
2915                 goto fail_sysfs;
2916         }
2917
2918         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2919                                                "btrfs-cleaner");
2920         if (IS_ERR(fs_info->cleaner_kthread))
2921                 goto fail_sysfs;
2922
2923         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2924                                                    tree_root,
2925                                                    "btrfs-transaction");
2926         if (IS_ERR(fs_info->transaction_kthread))
2927                 goto fail_cleaner;
2928
2929         if (!btrfs_test_opt(tree_root, SSD) &&
2930             !btrfs_test_opt(tree_root, NOSSD) &&
2931             !fs_info->fs_devices->rotating) {
2932                 printk(KERN_INFO "BTRFS: detected SSD devices, enabling SSD "
2933                        "mode\n");
2934                 btrfs_set_opt(fs_info->mount_opt, SSD);
2935         }
2936
2937         /*
2938          * Mount does not set all options immediatelly, we can do it now and do
2939          * not have to wait for transaction commit
2940          */
2941         btrfs_apply_pending_changes(fs_info);
2942
2943 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2944         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2945                 ret = btrfsic_mount(tree_root, fs_devices,
2946                                     btrfs_test_opt(tree_root,
2947                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2948                                     1 : 0,
2949                                     fs_info->check_integrity_print_mask);
2950                 if (ret)
2951                         printk(KERN_WARNING "BTRFS: failed to initialize"
2952                                " integrity check module %s\n", sb->s_id);
2953         }
2954 #endif
2955         ret = btrfs_read_qgroup_config(fs_info);
2956         if (ret)
2957                 goto fail_trans_kthread;
2958
2959         /* do not make disk changes in broken FS */
2960         if (btrfs_super_log_root(disk_super) != 0) {
2961                 ret = btrfs_replay_log(fs_info, fs_devices);
2962                 if (ret) {
2963                         err = ret;
2964                         goto fail_qgroup;
2965                 }
2966         }
2967
2968         ret = btrfs_find_orphan_roots(tree_root);
2969         if (ret)
2970                 goto fail_qgroup;
2971
2972         if (!(sb->s_flags & MS_RDONLY)) {
2973                 ret = btrfs_cleanup_fs_roots(fs_info);
2974                 if (ret)
2975                         goto fail_qgroup;
2976
2977                 mutex_lock(&fs_info->cleaner_mutex);
2978                 ret = btrfs_recover_relocation(tree_root);
2979                 mutex_unlock(&fs_info->cleaner_mutex);
2980                 if (ret < 0) {
2981                         printk(KERN_WARNING
2982                                "BTRFS: failed to recover relocation\n");
2983                         err = -EINVAL;
2984                         goto fail_qgroup;
2985                 }
2986         }
2987
2988         location.objectid = BTRFS_FS_TREE_OBJECTID;
2989         location.type = BTRFS_ROOT_ITEM_KEY;
2990         location.offset = 0;
2991
2992         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2993         if (IS_ERR(fs_info->fs_root)) {
2994                 err = PTR_ERR(fs_info->fs_root);
2995                 goto fail_qgroup;
2996         }
2997
2998         if (sb->s_flags & MS_RDONLY)
2999                 return 0;
3000
3001         down_read(&fs_info->cleanup_work_sem);
3002         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3003             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3004                 up_read(&fs_info->cleanup_work_sem);
3005                 close_ctree(tree_root);
3006                 return ret;
3007         }
3008         up_read(&fs_info->cleanup_work_sem);
3009
3010         ret = btrfs_resume_balance_async(fs_info);
3011         if (ret) {
3012                 printk(KERN_WARNING "BTRFS: failed to resume balance\n");
3013                 close_ctree(tree_root);
3014                 return ret;
3015         }
3016
3017         ret = btrfs_resume_dev_replace_async(fs_info);
3018         if (ret) {
3019                 pr_warn("BTRFS: failed to resume dev_replace\n");
3020                 close_ctree(tree_root);
3021                 return ret;
3022         }
3023
3024         btrfs_qgroup_rescan_resume(fs_info);
3025
3026         if (!fs_info->uuid_root) {
3027                 pr_info("BTRFS: creating UUID tree\n");
3028                 ret = btrfs_create_uuid_tree(fs_info);
3029                 if (ret) {
3030                         pr_warn("BTRFS: failed to create the UUID tree %d\n",
3031                                 ret);
3032                         close_ctree(tree_root);
3033                         return ret;
3034                 }
3035         } else if (btrfs_test_opt(tree_root, RESCAN_UUID_TREE) ||
3036                    fs_info->generation !=
3037                                 btrfs_super_uuid_tree_generation(disk_super)) {
3038                 pr_info("BTRFS: checking UUID tree\n");
3039                 ret = btrfs_check_uuid_tree(fs_info);
3040                 if (ret) {
3041                         pr_warn("BTRFS: failed to check the UUID tree %d\n",
3042                                 ret);
3043                         close_ctree(tree_root);
3044                         return ret;
3045                 }
3046         } else {
3047                 fs_info->update_uuid_tree_gen = 1;
3048         }
3049
3050         fs_info->open = 1;
3051
3052         return 0;
3053
3054 fail_qgroup:
3055         btrfs_free_qgroup_config(fs_info);
3056 fail_trans_kthread:
3057         kthread_stop(fs_info->transaction_kthread);
3058         btrfs_cleanup_transaction(fs_info->tree_root);
3059         btrfs_free_fs_roots(fs_info);
3060 fail_cleaner:
3061         kthread_stop(fs_info->cleaner_kthread);
3062
3063         /*
3064          * make sure we're done with the btree inode before we stop our
3065          * kthreads
3066          */
3067         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3068
3069 fail_sysfs:
3070         btrfs_sysfs_remove_one(fs_info);
3071
3072 fail_fsdev_sysfs:
3073         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3074
3075 fail_block_groups:
3076         btrfs_put_block_group_cache(fs_info);
3077         btrfs_free_block_groups(fs_info);
3078
3079 fail_tree_roots:
3080         free_root_pointers(fs_info, 1);
3081         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3082
3083 fail_sb_buffer:
3084         btrfs_stop_all_workers(fs_info);
3085 fail_alloc:
3086 fail_iput:
3087         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3088
3089         iput(fs_info->btree_inode);
3090 fail_bio_counter:
3091         percpu_counter_destroy(&fs_info->bio_counter);
3092 fail_delalloc_bytes:
3093         percpu_counter_destroy(&fs_info->delalloc_bytes);
3094 fail_dirty_metadata_bytes:
3095         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3096 fail_bdi:
3097         bdi_destroy(&fs_info->bdi);
3098 fail_srcu:
3099         cleanup_srcu_struct(&fs_info->subvol_srcu);
3100 fail:
3101         btrfs_free_stripe_hash_table(fs_info);
3102         btrfs_close_devices(fs_info->fs_devices);
3103         return err;
3104
3105 recovery_tree_root:
3106         if (!btrfs_test_opt(tree_root, RECOVERY))
3107                 goto fail_tree_roots;
3108
3109         free_root_pointers(fs_info, 0);
3110
3111         /* don't use the log in recovery mode, it won't be valid */
3112         btrfs_set_super_log_root(disk_super, 0);
3113
3114         /* we can't trust the free space cache either */
3115         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3116
3117         ret = next_root_backup(fs_info, fs_info->super_copy,
3118                                &num_backups_tried, &backup_index);
3119         if (ret == -1)
3120                 goto fail_block_groups;
3121         goto retry_root_backup;
3122 }
3123
3124 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3125 {
3126         if (uptodate) {
3127                 set_buffer_uptodate(bh);
3128         } else {
3129                 struct btrfs_device *device = (struct btrfs_device *)
3130                         bh->b_private;
3131
3132                 printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
3133                                           "I/O error on %s\n",
3134                                           rcu_str_deref(device->name));
3135                 /* note, we dont' set_buffer_write_io_error because we have
3136                  * our own ways of dealing with the IO errors
3137                  */
3138                 clear_buffer_uptodate(bh);
3139                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3140         }
3141         unlock_buffer(bh);
3142         put_bh(bh);
3143 }
3144
3145 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3146 {
3147         struct buffer_head *bh;
3148         struct buffer_head *latest = NULL;
3149         struct btrfs_super_block *super;
3150         int i;
3151         u64 transid = 0;
3152         u64 bytenr;
3153
3154         /* we would like to check all the supers, but that would make
3155          * a btrfs mount succeed after a mkfs from a different FS.
3156          * So, we need to add a special mount option to scan for
3157          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3158          */
3159         for (i = 0; i < 1; i++) {
3160                 bytenr = btrfs_sb_offset(i);
3161                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3162                                         i_size_read(bdev->bd_inode))
3163                         break;
3164                 bh = __bread(bdev, bytenr / 4096,
3165                                         BTRFS_SUPER_INFO_SIZE);
3166                 if (!bh)
3167                         continue;
3168
3169                 super = (struct btrfs_super_block *)bh->b_data;
3170                 if (btrfs_super_bytenr(super) != bytenr ||
3171                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3172                         brelse(bh);
3173                         continue;
3174                 }
3175
3176                 if (!latest || btrfs_super_generation(super) > transid) {
3177                         brelse(latest);
3178                         latest = bh;
3179                         transid = btrfs_super_generation(super);
3180                 } else {
3181                         brelse(bh);
3182                 }
3183         }
3184         return latest;
3185 }
3186
3187 /*
3188  * this should be called twice, once with wait == 0 and
3189  * once with wait == 1.  When wait == 0 is done, all the buffer heads
3190  * we write are pinned.
3191  *
3192  * They are released when wait == 1 is done.
3193  * max_mirrors must be the same for both runs, and it indicates how
3194  * many supers on this one device should be written.
3195  *
3196  * max_mirrors == 0 means to write them all.
3197  */
3198 static int write_dev_supers(struct btrfs_device *device,
3199                             struct btrfs_super_block *sb,
3200                             int do_barriers, int wait, int max_mirrors)
3201 {
3202         struct buffer_head *bh;
3203         int i;
3204         int ret;
3205         int errors = 0;
3206         u32 crc;
3207         u64 bytenr;
3208
3209         if (max_mirrors == 0)
3210                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3211
3212         for (i = 0; i < max_mirrors; i++) {
3213                 bytenr = btrfs_sb_offset(i);
3214                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3215                     device->commit_total_bytes)
3216                         break;
3217
3218                 if (wait) {
3219                         bh = __find_get_block(device->bdev, bytenr / 4096,
3220                                               BTRFS_SUPER_INFO_SIZE);
3221                         if (!bh) {
3222                                 errors++;
3223                                 continue;
3224                         }
3225                         wait_on_buffer(bh);
3226                         if (!buffer_uptodate(bh))
3227                                 errors++;
3228
3229                         /* drop our reference */
3230                         brelse(bh);
3231
3232                         /* drop the reference from the wait == 0 run */
3233                         brelse(bh);
3234                         continue;
3235                 } else {
3236                         btrfs_set_super_bytenr(sb, bytenr);
3237
3238                         crc = ~(u32)0;
3239                         crc = btrfs_csum_data((char *)sb +
3240                                               BTRFS_CSUM_SIZE, crc,
3241                                               BTRFS_SUPER_INFO_SIZE -
3242                                               BTRFS_CSUM_SIZE);
3243                         btrfs_csum_final(crc, sb->csum);
3244
3245                         /*
3246                          * one reference for us, and we leave it for the
3247                          * caller
3248                          */
3249                         bh = __getblk(device->bdev, bytenr / 4096,
3250                                       BTRFS_SUPER_INFO_SIZE);
3251                         if (!bh) {
3252                                 printk(KERN_ERR "BTRFS: couldn't get super "
3253                                        "buffer head for bytenr %Lu\n", bytenr);
3254                                 errors++;
3255                                 continue;
3256                         }
3257
3258                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3259
3260                         /* one reference for submit_bh */
3261                         get_bh(bh);
3262
3263                         set_buffer_uptodate(bh);
3264                         lock_buffer(bh);
3265                         bh->b_end_io = btrfs_end_buffer_write_sync;
3266                         bh->b_private = device;
3267                 }
3268
3269                 /*
3270                  * we fua the first super.  The others we allow
3271                  * to go down lazy.
3272                  */
3273                 if (i == 0)
3274                         ret = btrfsic_submit_bh(WRITE_FUA, bh);
3275                 else
3276                         ret = btrfsic_submit_bh(WRITE_SYNC, bh);
3277                 if (ret)
3278                         errors++;
3279         }
3280         return errors < i ? 0 : -1;
3281 }
3282
3283 /*
3284  * endio for the write_dev_flush, this will wake anyone waiting
3285  * for the barrier when it is done
3286  */
3287 static void btrfs_end_empty_barrier(struct bio *bio, int err)
3288 {
3289         if (err)
3290                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
3291         if (bio->bi_private)
3292                 complete(bio->bi_private);
3293         bio_put(bio);
3294 }
3295
3296 /*
3297  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
3298  * sent down.  With wait == 1, it waits for the previous flush.
3299  *
3300  * any device where the flush fails with eopnotsupp are flagged as not-barrier
3301  * capable
3302  */
3303 static int write_dev_flush(struct btrfs_device *device, int wait)
3304 {
3305         struct bio *bio;
3306         int ret = 0;
3307
3308         if (device->nobarriers)
3309                 return 0;
3310
3311         if (wait) {
3312                 bio = device->flush_bio;
3313                 if (!bio)
3314                         return 0;
3315
3316                 wait_for_completion(&device->flush_wait);
3317
3318                 if (!bio_flagged(bio, BIO_UPTODATE)) {
3319                         ret = -EIO;
3320                         btrfs_dev_stat_inc_and_print(device,
3321                                 BTRFS_DEV_STAT_FLUSH_ERRS);
3322                 }
3323
3324                 /* drop the reference from the wait == 0 run */
3325                 bio_put(bio);
3326                 device->flush_bio = NULL;
3327
3328                 return ret;
3329         }
3330
3331         /*
3332          * one reference for us, and we leave it for the
3333          * caller
3334          */
3335         device->flush_bio = NULL;
3336         bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
3337         if (!bio)
3338                 return -ENOMEM;
3339
3340         bio->bi_end_io = btrfs_end_empty_barrier;
3341         bio->bi_bdev = device->bdev;
3342         init_completion(&device->flush_wait);
3343         bio->bi_private = &device->flush_wait;
3344         device->flush_bio = bio;
3345
3346         bio_get(bio);
3347         btrfsic_submit_bio(WRITE_FLUSH, bio);
3348
3349         return 0;
3350 }
3351
3352 /*
3353  * send an empty flush down to each device in parallel,
3354  * then wait for them
3355  */
3356 static int barrier_all_devices(struct btrfs_fs_info *info)
3357 {
3358         struct list_head *head;
3359         struct btrfs_device *dev;
3360         int errors_send = 0;
3361         int errors_wait = 0;
3362         int ret;
3363
3364         /* send down all the barriers */
3365         head = &info->fs_devices->devices;
3366         list_for_each_entry_rcu(dev, head, dev_list) {
3367                 if (dev->missing)
3368                         continue;
3369                 if (!dev->bdev) {
3370                         errors_send++;
3371                         continue;
3372                 }
3373                 if (!dev->in_fs_metadata || !dev->writeable)
3374                         continue;
3375
3376                 ret = write_dev_flush(dev, 0);
3377                 if (ret)
3378                         errors_send++;
3379         }
3380
3381         /* wait for all the barriers */
3382         list_for_each_entry_rcu(dev, head, dev_list) {
3383                 if (dev->missing)
3384                         continue;
3385                 if (!dev->bdev) {
3386                         errors_wait++;
3387                         continue;
3388                 }
3389                 if (!dev->in_fs_metadata || !dev->writeable)
3390                         continue;
3391
3392                 ret = write_dev_flush(dev, 1);
3393                 if (ret)
3394                         errors_wait++;
3395         }
3396         if (errors_send > info->num_tolerated_disk_barrier_failures ||
3397             errors_wait > info->num_tolerated_disk_barrier_failures)
3398                 return -EIO;
3399         return 0;
3400 }
3401
3402 int btrfs_calc_num_tolerated_disk_barrier_failures(
3403         struct btrfs_fs_info *fs_info)
3404 {
3405         struct btrfs_ioctl_space_info space;
3406         struct btrfs_space_info *sinfo;
3407         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3408                        BTRFS_BLOCK_GROUP_SYSTEM,
3409                        BTRFS_BLOCK_GROUP_METADATA,
3410                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3411         int num_types = 4;
3412         int i;
3413         int c;
3414         int num_tolerated_disk_barrier_failures =
3415                 (int)fs_info->fs_devices->num_devices;
3416
3417         for (i = 0; i < num_types; i++) {
3418                 struct btrfs_space_info *tmp;
3419
3420                 sinfo = NULL;
3421                 rcu_read_lock();
3422                 list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
3423                         if (tmp->flags == types[i]) {
3424                                 sinfo = tmp;
3425                                 break;
3426                         }
3427                 }
3428                 rcu_read_unlock();
3429
3430                 if (!sinfo)
3431                         continue;
3432
3433                 down_read(&sinfo->groups_sem);
3434                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3435                         if (!list_empty(&sinfo->block_groups[c])) {
3436                                 u64 flags;
3437
3438                                 btrfs_get_block_group_info(
3439                                         &sinfo->block_groups[c], &space);
3440                                 if (space.total_bytes == 0 ||
3441                                     space.used_bytes == 0)
3442                                         continue;
3443                                 flags = space.flags;
3444                                 /*
3445                                  * return
3446                                  * 0: if dup, single or RAID0 is configured for
3447                                  *    any of metadata, system or data, else
3448                                  * 1: if RAID5 is configured, or if RAID1 or
3449                                  *    RAID10 is configured and only two mirrors
3450                                  *    are used, else
3451                                  * 2: if RAID6 is configured, else
3452                                  * num_mirrors - 1: if RAID1 or RAID10 is
3453                                  *                  configured and more than
3454                                  *                  2 mirrors are used.
3455                                  */
3456                                 if (num_tolerated_disk_barrier_failures > 0 &&
3457                                     ((flags & (BTRFS_BLOCK_GROUP_DUP |
3458                                                BTRFS_BLOCK_GROUP_RAID0)) ||
3459                                      ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
3460                                       == 0)))
3461                                         num_tolerated_disk_barrier_failures = 0;
3462                                 else if (num_tolerated_disk_barrier_failures > 1) {
3463                                         if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3464                                             BTRFS_BLOCK_GROUP_RAID5 |
3465                                             BTRFS_BLOCK_GROUP_RAID10)) {
3466                                                 num_tolerated_disk_barrier_failures = 1;
3467                                         } else if (flags &
3468                                                    BTRFS_BLOCK_GROUP_RAID6) {
3469                                                 num_tolerated_disk_barrier_failures = 2;
3470                                         }
3471                                 }
3472                         }
3473                 }
3474                 up_read(&sinfo->groups_sem);
3475         }
3476
3477         return num_tolerated_disk_barrier_failures;
3478 }
3479
3480 static int write_all_supers(struct btrfs_root *root, int max_mirrors)
3481 {
3482         struct list_head *head;
3483         struct btrfs_device *dev;
3484         struct btrfs_super_block *sb;
3485         struct btrfs_dev_item *dev_item;
3486         int ret;
3487         int do_barriers;
3488         int max_errors;
3489         int total_errors = 0;
3490         u64 flags;
3491
3492         do_barriers = !btrfs_test_opt(root, NOBARRIER);
3493         backup_super_roots(root->fs_info);
3494
3495         sb = root->fs_info->super_for_commit;
3496         dev_item = &sb->dev_item;
3497
3498         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3499         head = &root->fs_info->fs_devices->devices;
3500         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
3501
3502         if (do_barriers) {
3503                 ret = barrier_all_devices(root->fs_info);
3504                 if (ret) {
3505                         mutex_unlock(
3506                                 &root->fs_info->fs_devices->device_list_mutex);
3507                         btrfs_error(root->fs_info, ret,
3508                                     "errors while submitting device barriers.");
3509                         return ret;
3510                 }
3511         }
3512
3513         list_for_each_entry_rcu(dev, head, dev_list) {
3514                 if (!dev->bdev) {
3515                         total_errors++;
3516                         continue;
3517                 }
3518                 if (!dev->in_fs_metadata || !dev->writeable)
3519                         continue;
3520
3521                 btrfs_set_stack_device_generation(dev_item, 0);
3522                 btrfs_set_stack_device_type(dev_item, dev->type);
3523                 btrfs_set_stack_device_id(dev_item, dev->devid);
3524                 btrfs_set_stack_device_total_bytes(dev_item,
3525                                                    dev->commit_total_bytes);
3526                 btrfs_set_stack_device_bytes_used(dev_item,
3527                                                   dev->commit_bytes_used);
3528                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3529                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3530                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3531                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3532                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
3533
3534                 flags = btrfs_super_flags(sb);
3535                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3536
3537                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
3538                 if (ret)
3539                         total_errors++;
3540         }
3541         if (total_errors > max_errors) {
3542                 btrfs_err(root->fs_info, "%d errors while writing supers",
3543                        total_errors);
3544                 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3545
3546                 /* FUA is masked off if unsupported and can't be the reason */
3547                 btrfs_error(root->fs_info, -EIO,
3548                             "%d errors while writing supers", total_errors);
3549                 return -EIO;
3550         }
3551
3552         total_errors = 0;
3553         list_for_each_entry_rcu(dev, head, dev_list) {
3554                 if (!dev->bdev)
3555                         continue;
3556                 if (!dev->in_fs_metadata || !dev->writeable)
3557                         continue;
3558
3559                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
3560                 if (ret)
3561                         total_errors++;
3562         }
3563         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3564         if (total_errors > max_errors) {
3565                 btrfs_error(root->fs_info, -EIO,
3566                             "%d errors while writing supers", total_errors);
3567                 return -EIO;
3568         }
3569         return 0;
3570 }
3571
3572 int write_ctree_super(struct btrfs_trans_handle *trans,
3573                       struct btrfs_root *root, int max_mirrors)
3574 {
3575         return write_all_supers(root, max_mirrors);
3576 }
3577
3578 /* Drop a fs root from the radix tree and free it. */
3579 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
3580                                   struct btrfs_root *root)
3581 {
3582         spin_lock(&fs_info->fs_roots_radix_lock);
3583         radix_tree_delete(&fs_info->fs_roots_radix,
3584                           (unsigned long)root->root_key.objectid);
3585         spin_unlock(&fs_info->fs_roots_radix_lock);
3586
3587         if (btrfs_root_refs(&root->root_item) == 0)
3588                 synchronize_srcu(&fs_info->subvol_srcu);
3589
3590         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3591                 btrfs_free_log(NULL, root);
3592
3593         if (root->free_ino_pinned)
3594                 __btrfs_remove_free_space_cache(root->free_ino_pinned);
3595         if (root->free_ino_ctl)
3596                 __btrfs_remove_free_space_cache(root->free_ino_ctl);
3597         free_fs_root(root);
3598 }
3599
3600 static void free_fs_root(struct btrfs_root *root)
3601 {
3602         iput(root->ino_cache_inode);
3603         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3604         btrfs_free_block_rsv(root, root->orphan_block_rsv);
3605         root->orphan_block_rsv = NULL;
3606         if (root->anon_dev)
3607                 free_anon_bdev(root->anon_dev);
3608         if (root->subv_writers)
3609                 btrfs_free_subvolume_writers(root->subv_writers);
3610         free_extent_buffer(root->node);
3611         free_extent_buffer(root->commit_root);
3612         kfree(root->free_ino_ctl);
3613         kfree(root->free_ino_pinned);
3614         kfree(root->name);
3615         btrfs_put_fs_root(root);
3616 }
3617
3618 void btrfs_free_fs_root(struct btrfs_root *root)
3619 {
3620         free_fs_root(root);
3621 }
3622
3623 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3624 {
3625         u64 root_objectid = 0;
3626         struct btrfs_root *gang[8];
3627         int i = 0;
3628         int err = 0;
3629         unsigned int ret = 0;
3630         int index;
3631
3632         while (1) {
3633                 index = srcu_read_lock(&fs_info->subvol_srcu);
3634                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3635                                              (void **)gang, root_objectid,
3636                                              ARRAY_SIZE(gang));
3637                 if (!ret) {
3638                         srcu_read_unlock(&fs_info->subvol_srcu, index);
3639                         break;
3640                 }
3641                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3642
3643                 for (i = 0; i < ret; i++) {
3644                         /* Avoid to grab roots in dead_roots */
3645                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
3646                                 gang[i] = NULL;
3647                                 continue;
3648                         }
3649                         /* grab all the search result for later use */
3650                         gang[i] = btrfs_grab_fs_root(gang[i]);
3651                 }
3652                 srcu_read_unlock(&fs_info->subvol_srcu, index);
3653
3654                 for (i = 0; i < ret; i++) {
3655                         if (!gang[i])
3656                                 continue;
3657                         root_objectid = gang[i]->root_key.objectid;
3658                         err = btrfs_orphan_cleanup(gang[i]);
3659                         if (err)
3660                                 break;
3661                         btrfs_put_fs_root(gang[i]);
3662                 }
3663                 root_objectid++;
3664         }
3665
3666         /* release the uncleaned roots due to error */
3667         for (; i < ret; i++) {
3668                 if (gang[i])
3669                         btrfs_put_fs_root(gang[i]);
3670         }
3671         return err;
3672 }
3673
3674 int btrfs_commit_super(struct btrfs_root *root)
3675 {
3676         struct btrfs_trans_handle *trans;
3677
3678         mutex_lock(&root->fs_info->cleaner_mutex);
3679         btrfs_run_delayed_iputs(root);
3680         mutex_unlock(&root->fs_info->cleaner_mutex);
3681         wake_up_process(root->fs_info->cleaner_kthread);
3682
3683         /* wait until ongoing cleanup work done */
3684         down_write(&root->fs_info->cleanup_work_sem);
3685         up_write(&root->fs_info->cleanup_work_sem);
3686
3687         trans = btrfs_join_transaction(root);
3688         if (IS_ERR(trans))
3689                 return PTR_ERR(trans);
3690         return btrfs_commit_transaction(trans, root);
3691 }
3692
3693 void close_ctree(struct btrfs_root *root)
3694 {
3695         struct btrfs_fs_info *fs_info = root->fs_info;
3696         int ret;
3697
3698         fs_info->closing = 1;
3699         smp_mb();
3700
3701         /* wait for the uuid_scan task to finish */
3702         down(&fs_info->uuid_tree_rescan_sem);
3703         /* avoid complains from lockdep et al., set sem back to initial state */
3704         up(&fs_info->uuid_tree_rescan_sem);
3705
3706         /* pause restriper - we want to resume on mount */
3707         btrfs_pause_balance(fs_info);
3708
3709         btrfs_dev_replace_suspend_for_unmount(fs_info);
3710
3711         btrfs_scrub_cancel(fs_info);
3712
3713         /* wait for any defraggers to finish */
3714         wait_event(fs_info->transaction_wait,
3715                    (atomic_read(&fs_info->defrag_running) == 0));
3716
3717         /* clear out the rbtree of defraggable inodes */
3718         btrfs_cleanup_defrag_inodes(fs_info);
3719
3720         cancel_work_sync(&fs_info->async_reclaim_work);
3721
3722         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3723                 ret = btrfs_commit_super(root);
3724                 if (ret)
3725                         btrfs_err(fs_info, "commit super ret %d", ret);
3726         }
3727
3728         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3729                 btrfs_error_commit_super(root);
3730
3731         kthread_stop(fs_info->transaction_kthread);
3732         kthread_stop(fs_info->cleaner_kthread);
3733
3734         fs_info->closing = 2;
3735         smp_mb();
3736
3737         btrfs_free_qgroup_config(fs_info);
3738
3739         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
3740                 btrfs_info(fs_info, "at unmount delalloc count %lld",
3741                        percpu_counter_sum(&fs_info->delalloc_bytes));
3742         }
3743
3744         btrfs_sysfs_remove_one(fs_info);
3745         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3746
3747         btrfs_free_fs_roots(fs_info);
3748
3749         btrfs_put_block_group_cache(fs_info);
3750
3751         btrfs_free_block_groups(fs_info);
3752
3753         /*
3754          * we must make sure there is not any read request to
3755          * submit after we stopping all workers.
3756          */
3757         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3758         btrfs_stop_all_workers(fs_info);
3759
3760         fs_info->open = 0;
3761         free_root_pointers(fs_info, 1);
3762
3763         iput(fs_info->btree_inode);
3764
3765 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3766         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3767                 btrfsic_unmount(root, fs_info->fs_devices);
3768 #endif
3769
3770         btrfs_close_devices(fs_info->fs_devices);
3771         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3772
3773         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3774         percpu_counter_destroy(&fs_info->delalloc_bytes);
3775         percpu_counter_destroy(&fs_info->bio_counter);
3776         bdi_destroy(&fs_info->bdi);
3777         cleanup_srcu_struct(&fs_info->subvol_srcu);
3778
3779         btrfs_free_stripe_hash_table(fs_info);
3780
3781         __btrfs_free_block_rsv(root->orphan_block_rsv);
3782         root->orphan_block_rsv = NULL;
3783
3784         lock_chunks(root);
3785         while (!list_empty(&fs_info->pinned_chunks)) {
3786                 struct extent_map *em;
3787
3788                 em = list_first_entry(&fs_info->pinned_chunks,
3789                                       struct extent_map, list);
3790                 list_del_init(&em->list);
3791                 free_extent_map(em);
3792         }
3793         unlock_chunks(root);
3794 }
3795
3796 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3797                           int atomic)
3798 {
3799         int ret;
3800         struct inode *btree_inode = buf->pages[0]->mapping->host;
3801
3802         ret = extent_buffer_uptodate(buf);
3803         if (!ret)
3804                 return ret;
3805
3806         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3807                                     parent_transid, atomic);
3808         if (ret == -EAGAIN)
3809                 return ret;
3810         return !ret;
3811 }
3812
3813 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3814 {
3815         return set_extent_buffer_uptodate(buf);
3816 }
3817
3818 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3819 {
3820         struct btrfs_root *root;
3821         u64 transid = btrfs_header_generation(buf);
3822         int was_dirty;
3823
3824 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3825         /*
3826          * This is a fast path so only do this check if we have sanity tests
3827          * enabled.  Normal people shouldn't be marking dummy buffers as dirty
3828          * outside of the sanity tests.
3829          */
3830         if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &buf->bflags)))
3831                 return;
3832 #endif
3833         root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3834         btrfs_assert_tree_locked(buf);
3835         if (transid != root->fs_info->generation)
3836                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, "
3837                        "found %llu running %llu\n",
3838                         buf->start, transid, root->fs_info->generation);
3839         was_dirty = set_extent_buffer_dirty(buf);
3840         if (!was_dirty)
3841                 __percpu_counter_add(&root->fs_info->dirty_metadata_bytes,
3842                                      buf->len,
3843                                      root->fs_info->dirty_metadata_batch);
3844 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3845         if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) {
3846                 btrfs_print_leaf(root, buf);
3847                 ASSERT(0);
3848         }
3849 #endif
3850 }
3851
3852 static void __btrfs_btree_balance_dirty(struct btrfs_root *root,
3853                                         int flush_delayed)
3854 {
3855         /*
3856          * looks as though older kernels can get into trouble with
3857          * this code, they end up stuck in balance_dirty_pages forever
3858          */
3859         int ret;
3860
3861         if (current->flags & PF_MEMALLOC)
3862                 return;
3863
3864         if (flush_delayed)
3865                 btrfs_balance_delayed_items(root);
3866
3867         ret = percpu_counter_compare(&root->fs_info->dirty_metadata_bytes,
3868                                      BTRFS_DIRTY_METADATA_THRESH);
3869         if (ret > 0) {
3870                 balance_dirty_pages_ratelimited(
3871                                    root->fs_info->btree_inode->i_mapping);
3872         }
3873         return;
3874 }
3875
3876 void btrfs_btree_balance_dirty(struct btrfs_root *root)
3877 {
3878         __btrfs_btree_balance_dirty(root, 1);
3879 }
3880
3881 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root)
3882 {
3883         __btrfs_btree_balance_dirty(root, 0);
3884 }
3885
3886 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3887 {
3888         struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3889         return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3890 }
3891
3892 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3893                               int read_only)
3894 {
3895         struct btrfs_super_block *sb = fs_info->super_copy;
3896         int ret = 0;
3897
3898         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
3899                 printk(KERN_ERR "BTRFS: tree_root level too big: %d >= %d\n",
3900                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
3901                 ret = -EINVAL;
3902         }
3903         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
3904                 printk(KERN_ERR "BTRFS: chunk_root level too big: %d >= %d\n",
3905                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
3906                 ret = -EINVAL;
3907         }
3908         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
3909                 printk(KERN_ERR "BTRFS: log_root level too big: %d >= %d\n",
3910                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
3911                 ret = -EINVAL;
3912         }
3913
3914         /*
3915          * The common minimum, we don't know if we can trust the nodesize/sectorsize
3916          * items yet, they'll be verified later. Issue just a warning.
3917          */
3918         if (!IS_ALIGNED(btrfs_super_root(sb), 4096))
3919                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
3920                                 btrfs_super_root(sb));
3921         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096))
3922                 printk(KERN_WARNING "BTRFS: chunk_root block unaligned: %llu\n",
3923                                 btrfs_super_chunk_root(sb));
3924         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096))
3925                 printk(KERN_WARNING "BTRFS: log_root block unaligned: %llu\n",
3926                                 btrfs_super_log_root(sb));
3927
3928         /*
3929          * Check the lower bound, the alignment and other constraints are
3930          * checked later.
3931          */
3932         if (btrfs_super_nodesize(sb) < 4096) {
3933                 printk(KERN_ERR "BTRFS: nodesize too small: %u < 4096\n",
3934                                 btrfs_super_nodesize(sb));
3935                 ret = -EINVAL;
3936         }
3937         if (btrfs_super_sectorsize(sb) < 4096) {
3938                 printk(KERN_ERR "BTRFS: sectorsize too small: %u < 4096\n",
3939                                 btrfs_super_sectorsize(sb));
3940                 ret = -EINVAL;
3941         }
3942
3943         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
3944                 printk(KERN_ERR "BTRFS: dev_item UUID does not match fsid: %pU != %pU\n",
3945                                 fs_info->fsid, sb->dev_item.fsid);
3946                 ret = -EINVAL;
3947         }
3948
3949         /*
3950          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
3951          * done later
3952          */
3953         if (btrfs_super_num_devices(sb) > (1UL << 31))
3954                 printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
3955                                 btrfs_super_num_devices(sb));
3956         if (btrfs_super_num_devices(sb) == 0) {
3957                 printk(KERN_ERR "BTRFS: number of devices is 0\n");
3958                 ret = -EINVAL;
3959         }
3960
3961         if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
3962                 printk(KERN_ERR "BTRFS: super offset mismatch %llu != %u\n",
3963                                 btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
3964                 ret = -EINVAL;
3965         }
3966
3967         /*
3968          * Obvious sys_chunk_array corruptions, it must hold at least one key
3969          * and one chunk
3970          */
3971         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
3972                 printk(KERN_ERR "BTRFS: system chunk array too big %u > %u\n",
3973                                 btrfs_super_sys_array_size(sb),
3974                                 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
3975                 ret = -EINVAL;
3976         }
3977         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
3978                         + sizeof(struct btrfs_chunk)) {
3979                 printk(KERN_ERR "BTRFS: system chunk array too small %u < %zu\n",
3980                                 btrfs_super_sys_array_size(sb),
3981                                 sizeof(struct btrfs_disk_key)
3982                                 + sizeof(struct btrfs_chunk));
3983                 ret = -EINVAL;
3984         }
3985
3986         /*
3987          * The generation is a global counter, we'll trust it more than the others
3988          * but it's still possible that it's the one that's wrong.
3989          */
3990         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
3991                 printk(KERN_WARNING
3992                         "BTRFS: suspicious: generation < chunk_root_generation: %llu < %llu\n",
3993                         btrfs_super_generation(sb), btrfs_super_chunk_root_generation(sb));
3994         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
3995             && btrfs_super_cache_generation(sb) != (u64)-1)
3996                 printk(KERN_WARNING
3997                         "BTRFS: suspicious: generation < cache_generation: %llu < %llu\n",
3998                         btrfs_super_generation(sb), btrfs_super_cache_generation(sb));
3999
4000         return ret;
4001 }
4002
4003 static void btrfs_error_commit_super(struct btrfs_root *root)
4004 {
4005         mutex_lock(&root->fs_info->cleaner_mutex);
4006         btrfs_run_delayed_iputs(root);
4007         mutex_unlock(&root->fs_info->cleaner_mutex);
4008
4009         down_write(&root->fs_info->cleanup_work_sem);
4010         up_write(&root->fs_info->cleanup_work_sem);
4011
4012         /* cleanup FS via transaction */
4013         btrfs_cleanup_transaction(root);
4014 }
4015
4016 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4017 {
4018         struct btrfs_ordered_extent *ordered;
4019
4020         spin_lock(&root->ordered_extent_lock);
4021         /*
4022          * This will just short circuit the ordered completion stuff which will
4023          * make sure the ordered extent gets properly cleaned up.
4024          */
4025         list_for_each_entry(ordered, &root->ordered_extents,
4026                             root_extent_list)
4027                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4028         spin_unlock(&root->ordered_extent_lock);
4029 }
4030
4031 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4032 {
4033         struct btrfs_root *root;
4034         struct list_head splice;
4035
4036         INIT_LIST_HEAD(&splice);
4037
4038         spin_lock(&fs_info->ordered_root_lock);
4039         list_splice_init(&fs_info->ordered_roots, &splice);
4040         while (!list_empty(&splice)) {
4041                 root = list_first_entry(&splice, struct btrfs_root,
4042                                         ordered_root);
4043                 list_move_tail(&root->ordered_root,
4044                                &fs_info->ordered_roots);
4045
4046                 spin_unlock(&fs_info->ordered_root_lock);
4047                 btrfs_destroy_ordered_extents(root);
4048
4049                 cond_resched();
4050                 spin_lock(&fs_info->ordered_root_lock);
4051         }
4052         spin_unlock(&fs_info->ordered_root_lock);
4053 }
4054
4055 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4056                                       struct btrfs_root *root)
4057 {
4058         struct rb_node *node;
4059         struct btrfs_delayed_ref_root *delayed_refs;
4060         struct btrfs_delayed_ref_node *ref;
4061         int ret = 0;
4062
4063         delayed_refs = &trans->delayed_refs;
4064
4065         spin_lock(&delayed_refs->lock);
4066         if (atomic_read(&delayed_refs->num_entries) == 0) {
4067                 spin_unlock(&delayed_refs->lock);
4068                 btrfs_info(root->fs_info, "delayed_refs has NO entry");
4069                 return ret;
4070         }
4071
4072         while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
4073                 struct btrfs_delayed_ref_head *head;
4074                 struct btrfs_delayed_ref_node *tmp;
4075                 bool pin_bytes = false;
4076
4077                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4078                                 href_node);
4079                 if (!mutex_trylock(&head->mutex)) {
4080                         atomic_inc(&head->node.refs);
4081                         spin_unlock(&delayed_refs->lock);
4082
4083                         mutex_lock(&head->mutex);
4084                         mutex_unlock(&head->mutex);
4085                         btrfs_put_delayed_ref(&head->node);
4086                         spin_lock(&delayed_refs->lock);
4087                         continue;
4088                 }
4089                 spin_lock(&head->lock);
4090                 list_for_each_entry_safe_reverse(ref, tmp, &head->ref_list,
4091                                                  list) {
4092                         ref->in_tree = 0;
4093                         list_del(&ref->list);
4094                         atomic_dec(&delayed_refs->num_entries);
4095                         btrfs_put_delayed_ref(ref);
4096                 }
4097                 if (head->must_insert_reserved)
4098                         pin_bytes = true;
4099                 btrfs_free_delayed_extent_op(head->extent_op);
4100                 delayed_refs->num_heads--;
4101                 if (head->processing == 0)
4102                         delayed_refs->num_heads_ready--;
4103                 atomic_dec(&delayed_refs->num_entries);
4104                 head->node.in_tree = 0;
4105                 rb_erase(&head->href_node, &delayed_refs->href_root);
4106                 spin_unlock(&head->lock);
4107                 spin_unlock(&delayed_refs->lock);
4108                 mutex_unlock(&head->mutex);
4109
4110                 if (pin_bytes)
4111                         btrfs_pin_extent(root, head->node.bytenr,
4112                                          head->node.num_bytes, 1);
4113                 btrfs_put_delayed_ref(&head->node);
4114                 cond_resched();
4115                 spin_lock(&delayed_refs->lock);
4116         }
4117
4118         spin_unlock(&delayed_refs->lock);
4119
4120         return ret;
4121 }
4122
4123 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4124 {
4125         struct btrfs_inode *btrfs_inode;
4126         struct list_head splice;
4127
4128         INIT_LIST_HEAD(&splice);
4129
4130         spin_lock(&root->delalloc_lock);
4131         list_splice_init(&root->delalloc_inodes, &splice);
4132
4133         while (!list_empty(&splice)) {
4134                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4135                                                delalloc_inodes);
4136
4137                 list_del_init(&btrfs_inode->delalloc_inodes);
4138                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
4139                           &btrfs_inode->runtime_flags);
4140                 spin_unlock(&root->delalloc_lock);
4141
4142                 btrfs_invalidate_inodes(btrfs_inode->root);
4143
4144                 spin_lock(&root->delalloc_lock);
4145         }
4146
4147         spin_unlock(&root->delalloc_lock);
4148 }
4149
4150 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4151 {
4152         struct btrfs_root *root;
4153         struct list_head splice;
4154
4155         INIT_LIST_HEAD(&splice);
4156
4157         spin_lock(&fs_info->delalloc_root_lock);
4158         list_splice_init(&fs_info->delalloc_roots, &splice);
4159         while (!list_empty(&splice)) {
4160                 root = list_first_entry(&splice, struct btrfs_root,
4161                                          delalloc_root);
4162                 list_del_init(&root->delalloc_root);
4163                 root = btrfs_grab_fs_root(root);
4164                 BUG_ON(!root);
4165                 spin_unlock(&fs_info->delalloc_root_lock);
4166
4167                 btrfs_destroy_delalloc_inodes(root);
4168                 btrfs_put_fs_root(root);
4169
4170                 spin_lock(&fs_info->delalloc_root_lock);
4171         }
4172         spin_unlock(&fs_info->delalloc_root_lock);
4173 }
4174
4175 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
4176                                         struct extent_io_tree *dirty_pages,
4177                                         int mark)
4178 {
4179         int ret;
4180         struct extent_buffer *eb;
4181         u64 start = 0;
4182         u64 end;
4183
4184         while (1) {
4185                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4186                                             mark, NULL);
4187                 if (ret)
4188                         break;
4189
4190                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
4191                 while (start <= end) {
4192                         eb = btrfs_find_tree_block(root->fs_info, start);
4193                         start += root->nodesize;
4194                         if (!eb)
4195                                 continue;
4196                         wait_on_extent_buffer_writeback(eb);
4197
4198                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4199                                                &eb->bflags))
4200                                 clear_extent_buffer_dirty(eb);
4201                         free_extent_buffer_stale(eb);
4202                 }
4203         }
4204
4205         return ret;
4206 }
4207
4208 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
4209                                        struct extent_io_tree *pinned_extents)
4210 {
4211         struct extent_io_tree *unpin;
4212         u64 start;
4213         u64 end;
4214         int ret;
4215         bool loop = true;
4216
4217         unpin = pinned_extents;
4218 again:
4219         while (1) {
4220                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4221                                             EXTENT_DIRTY, NULL);
4222                 if (ret)
4223                         break;
4224
4225                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4226                 btrfs_error_unpin_extent_range(root, start, end);
4227                 cond_resched();
4228         }
4229
4230         if (loop) {
4231                 if (unpin == &root->fs_info->freed_extents[0])
4232                         unpin = &root->fs_info->freed_extents[1];
4233                 else
4234                         unpin = &root->fs_info->freed_extents[0];
4235                 loop = false;
4236                 goto again;
4237         }
4238
4239         return 0;
4240 }
4241
4242 static void btrfs_free_pending_ordered(struct btrfs_transaction *cur_trans,
4243                                        struct btrfs_fs_info *fs_info)
4244 {
4245         struct btrfs_ordered_extent *ordered;
4246
4247         spin_lock(&fs_info->trans_lock);
4248         while (!list_empty(&cur_trans->pending_ordered)) {
4249                 ordered = list_first_entry(&cur_trans->pending_ordered,
4250                                            struct btrfs_ordered_extent,
4251                                            trans_list);
4252                 list_del_init(&ordered->trans_list);
4253                 spin_unlock(&fs_info->trans_lock);
4254
4255                 btrfs_put_ordered_extent(ordered);
4256                 spin_lock(&fs_info->trans_lock);
4257         }
4258         spin_unlock(&fs_info->trans_lock);
4259 }
4260
4261 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4262                                    struct btrfs_root *root)
4263 {
4264         btrfs_destroy_delayed_refs(cur_trans, root);
4265
4266         cur_trans->state = TRANS_STATE_COMMIT_START;
4267         wake_up(&root->fs_info->transaction_blocked_wait);
4268
4269         cur_trans->state = TRANS_STATE_UNBLOCKED;
4270         wake_up(&root->fs_info->transaction_wait);
4271
4272         btrfs_free_pending_ordered(cur_trans, root->fs_info);
4273         btrfs_destroy_delayed_inodes(root);
4274         btrfs_assert_delayed_root_empty(root);
4275
4276         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
4277                                      EXTENT_DIRTY);
4278         btrfs_destroy_pinned_extent(root,
4279                                     root->fs_info->pinned_extents);
4280
4281         cur_trans->state =TRANS_STATE_COMPLETED;
4282         wake_up(&cur_trans->commit_wait);
4283
4284         /*
4285         memset(cur_trans, 0, sizeof(*cur_trans));
4286         kmem_cache_free(btrfs_transaction_cachep, cur_trans);
4287         */
4288 }
4289
4290 static int btrfs_cleanup_transaction(struct btrfs_root *root)
4291 {
4292         struct btrfs_transaction *t;
4293
4294         mutex_lock(&root->fs_info->transaction_kthread_mutex);
4295
4296         spin_lock(&root->fs_info->trans_lock);
4297         while (!list_empty(&root->fs_info->trans_list)) {
4298                 t = list_first_entry(&root->fs_info->trans_list,
4299                                      struct btrfs_transaction, list);
4300                 if (t->state >= TRANS_STATE_COMMIT_START) {
4301                         atomic_inc(&t->use_count);
4302                         spin_unlock(&root->fs_info->trans_lock);
4303                         btrfs_wait_for_commit(root, t->transid);
4304                         btrfs_put_transaction(t);
4305                         spin_lock(&root->fs_info->trans_lock);
4306                         continue;
4307                 }
4308                 if (t == root->fs_info->running_transaction) {
4309                         t->state = TRANS_STATE_COMMIT_DOING;
4310                         spin_unlock(&root->fs_info->trans_lock);
4311                         /*
4312                          * We wait for 0 num_writers since we don't hold a trans
4313                          * handle open currently for this transaction.
4314                          */
4315                         wait_event(t->writer_wait,
4316                                    atomic_read(&t->num_writers) == 0);
4317                 } else {
4318                         spin_unlock(&root->fs_info->trans_lock);
4319                 }
4320                 btrfs_cleanup_one_transaction(t, root);
4321
4322                 spin_lock(&root->fs_info->trans_lock);
4323                 if (t == root->fs_info->running_transaction)
4324                         root->fs_info->running_transaction = NULL;
4325                 list_del_init(&t->list);
4326                 spin_unlock(&root->fs_info->trans_lock);
4327
4328                 btrfs_put_transaction(t);
4329                 trace_btrfs_transaction_commit(root);
4330                 spin_lock(&root->fs_info->trans_lock);
4331         }
4332         spin_unlock(&root->fs_info->trans_lock);
4333         btrfs_destroy_all_ordered_extents(root->fs_info);
4334         btrfs_destroy_delayed_inodes(root);
4335         btrfs_assert_delayed_root_empty(root);
4336         btrfs_destroy_pinned_extent(root, root->fs_info->pinned_extents);
4337         btrfs_destroy_all_delalloc_inodes(root->fs_info);
4338         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
4339
4340         return 0;
4341 }
4342
4343 static const struct extent_io_ops btree_extent_io_ops = {
4344         .readpage_end_io_hook = btree_readpage_end_io_hook,
4345         .readpage_io_failed_hook = btree_io_failed_hook,
4346         .submit_bio_hook = btree_submit_bio_hook,
4347         /* note we're sharing with inode.c for the merge bio hook */
4348         .merge_bio_hook = btrfs_merge_bio_hook,
4349 };