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Merge branch 'for-linus' of git://gitorious.org/linux-omap-dss2/linux
[mirror_ubuntu-bionic-kernel.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/crc32c.h>
30 #include <linux/slab.h>
31 #include "compat.h"
32 #include "ctree.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "btrfs_inode.h"
36 #include "volumes.h"
37 #include "print-tree.h"
38 #include "async-thread.h"
39 #include "locking.h"
40 #include "tree-log.h"
41 #include "free-space-cache.h"
42
43 static struct extent_io_ops btree_extent_io_ops;
44 static void end_workqueue_fn(struct btrfs_work *work);
45 static void free_fs_root(struct btrfs_root *root);
46
47 /*
48 * end_io_wq structs are used to do processing in task context when an IO is
49 * complete. This is used during reads to verify checksums, and it is used
50 * by writes to insert metadata for new file extents after IO is complete.
51 */
52 struct end_io_wq {
53 struct bio *bio;
54 bio_end_io_t *end_io;
55 void *private;
56 struct btrfs_fs_info *info;
57 int error;
58 int metadata;
59 struct list_head list;
60 struct btrfs_work work;
61 };
62
63 /*
64 * async submit bios are used to offload expensive checksumming
65 * onto the worker threads. They checksum file and metadata bios
66 * just before they are sent down the IO stack.
67 */
68 struct async_submit_bio {
69 struct inode *inode;
70 struct bio *bio;
71 struct list_head list;
72 extent_submit_bio_hook_t *submit_bio_start;
73 extent_submit_bio_hook_t *submit_bio_done;
74 int rw;
75 int mirror_num;
76 unsigned long bio_flags;
77 /*
78 * bio_offset is optional, can be used if the pages in the bio
79 * can't tell us where in the file the bio should go
80 */
81 u64 bio_offset;
82 struct btrfs_work work;
83 };
84
85 /* These are used to set the lockdep class on the extent buffer locks.
86 * The class is set by the readpage_end_io_hook after the buffer has
87 * passed csum validation but before the pages are unlocked.
88 *
89 * The lockdep class is also set by btrfs_init_new_buffer on freshly
90 * allocated blocks.
91 *
92 * The class is based on the level in the tree block, which allows lockdep
93 * to know that lower nodes nest inside the locks of higher nodes.
94 *
95 * We also add a check to make sure the highest level of the tree is
96 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
97 * code needs update as well.
98 */
99 #ifdef CONFIG_DEBUG_LOCK_ALLOC
100 # if BTRFS_MAX_LEVEL != 8
101 # error
102 # endif
103 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
104 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
105 /* leaf */
106 "btrfs-extent-00",
107 "btrfs-extent-01",
108 "btrfs-extent-02",
109 "btrfs-extent-03",
110 "btrfs-extent-04",
111 "btrfs-extent-05",
112 "btrfs-extent-06",
113 "btrfs-extent-07",
114 /* highest possible level */
115 "btrfs-extent-08",
116 };
117 #endif
118
119 /*
120 * extents on the btree inode are pretty simple, there's one extent
121 * that covers the entire device
122 */
123 static struct extent_map *btree_get_extent(struct inode *inode,
124 struct page *page, size_t page_offset, u64 start, u64 len,
125 int create)
126 {
127 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
128 struct extent_map *em;
129 int ret;
130
131 read_lock(&em_tree->lock);
132 em = lookup_extent_mapping(em_tree, start, len);
133 if (em) {
134 em->bdev =
135 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
136 read_unlock(&em_tree->lock);
137 goto out;
138 }
139 read_unlock(&em_tree->lock);
140
141 em = alloc_extent_map(GFP_NOFS);
142 if (!em) {
143 em = ERR_PTR(-ENOMEM);
144 goto out;
145 }
146 em->start = 0;
147 em->len = (u64)-1;
148 em->block_len = (u64)-1;
149 em->block_start = 0;
150 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
151
152 write_lock(&em_tree->lock);
153 ret = add_extent_mapping(em_tree, em);
154 if (ret == -EEXIST) {
155 u64 failed_start = em->start;
156 u64 failed_len = em->len;
157
158 free_extent_map(em);
159 em = lookup_extent_mapping(em_tree, start, len);
160 if (em) {
161 ret = 0;
162 } else {
163 em = lookup_extent_mapping(em_tree, failed_start,
164 failed_len);
165 ret = -EIO;
166 }
167 } else if (ret) {
168 free_extent_map(em);
169 em = NULL;
170 }
171 write_unlock(&em_tree->lock);
172
173 if (ret)
174 em = ERR_PTR(ret);
175 out:
176 return em;
177 }
178
179 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
180 {
181 return crc32c(seed, data, len);
182 }
183
184 void btrfs_csum_final(u32 crc, char *result)
185 {
186 *(__le32 *)result = ~cpu_to_le32(crc);
187 }
188
189 /*
190 * compute the csum for a btree block, and either verify it or write it
191 * into the csum field of the block.
192 */
193 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
194 int verify)
195 {
196 u16 csum_size =
197 btrfs_super_csum_size(&root->fs_info->super_copy);
198 char *result = NULL;
199 unsigned long len;
200 unsigned long cur_len;
201 unsigned long offset = BTRFS_CSUM_SIZE;
202 char *map_token = NULL;
203 char *kaddr;
204 unsigned long map_start;
205 unsigned long map_len;
206 int err;
207 u32 crc = ~(u32)0;
208 unsigned long inline_result;
209
210 len = buf->len - offset;
211 while (len > 0) {
212 err = map_private_extent_buffer(buf, offset, 32,
213 &map_token, &kaddr,
214 &map_start, &map_len, KM_USER0);
215 if (err)
216 return 1;
217 cur_len = min(len, map_len - (offset - map_start));
218 crc = btrfs_csum_data(root, kaddr + offset - map_start,
219 crc, cur_len);
220 len -= cur_len;
221 offset += cur_len;
222 unmap_extent_buffer(buf, map_token, KM_USER0);
223 }
224 if (csum_size > sizeof(inline_result)) {
225 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
226 if (!result)
227 return 1;
228 } else {
229 result = (char *)&inline_result;
230 }
231
232 btrfs_csum_final(crc, result);
233
234 if (verify) {
235 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
236 u32 val;
237 u32 found = 0;
238 memcpy(&found, result, csum_size);
239
240 read_extent_buffer(buf, &val, 0, csum_size);
241 if (printk_ratelimit()) {
242 printk(KERN_INFO "btrfs: %s checksum verify "
243 "failed on %llu wanted %X found %X "
244 "level %d\n",
245 root->fs_info->sb->s_id,
246 (unsigned long long)buf->start, val, found,
247 btrfs_header_level(buf));
248 }
249 if (result != (char *)&inline_result)
250 kfree(result);
251 return 1;
252 }
253 } else {
254 write_extent_buffer(buf, result, 0, csum_size);
255 }
256 if (result != (char *)&inline_result)
257 kfree(result);
258 return 0;
259 }
260
261 /*
262 * we can't consider a given block up to date unless the transid of the
263 * block matches the transid in the parent node's pointer. This is how we
264 * detect blocks that either didn't get written at all or got written
265 * in the wrong place.
266 */
267 static int verify_parent_transid(struct extent_io_tree *io_tree,
268 struct extent_buffer *eb, u64 parent_transid)
269 {
270 struct extent_state *cached_state = NULL;
271 int ret;
272
273 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
274 return 0;
275
276 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
277 0, &cached_state, GFP_NOFS);
278 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
279 btrfs_header_generation(eb) == parent_transid) {
280 ret = 0;
281 goto out;
282 }
283 if (printk_ratelimit()) {
284 printk("parent transid verify failed on %llu wanted %llu "
285 "found %llu\n",
286 (unsigned long long)eb->start,
287 (unsigned long long)parent_transid,
288 (unsigned long long)btrfs_header_generation(eb));
289 }
290 ret = 1;
291 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
292 out:
293 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
294 &cached_state, GFP_NOFS);
295 return ret;
296 }
297
298 /*
299 * helper to read a given tree block, doing retries as required when
300 * the checksums don't match and we have alternate mirrors to try.
301 */
302 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
303 struct extent_buffer *eb,
304 u64 start, u64 parent_transid)
305 {
306 struct extent_io_tree *io_tree;
307 int ret;
308 int num_copies = 0;
309 int mirror_num = 0;
310
311 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
312 while (1) {
313 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
314 btree_get_extent, mirror_num);
315 if (!ret &&
316 !verify_parent_transid(io_tree, eb, parent_transid))
317 return ret;
318
319 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
320 eb->start, eb->len);
321 if (num_copies == 1)
322 return ret;
323
324 mirror_num++;
325 if (mirror_num > num_copies)
326 return ret;
327 }
328 return -EIO;
329 }
330
331 /*
332 * checksum a dirty tree block before IO. This has extra checks to make sure
333 * we only fill in the checksum field in the first page of a multi-page block
334 */
335
336 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
337 {
338 struct extent_io_tree *tree;
339 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
340 u64 found_start;
341 int found_level;
342 unsigned long len;
343 struct extent_buffer *eb;
344 int ret;
345
346 tree = &BTRFS_I(page->mapping->host)->io_tree;
347
348 if (page->private == EXTENT_PAGE_PRIVATE)
349 goto out;
350 if (!page->private)
351 goto out;
352 len = page->private >> 2;
353 WARN_ON(len == 0);
354
355 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
356 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
357 btrfs_header_generation(eb));
358 BUG_ON(ret);
359 found_start = btrfs_header_bytenr(eb);
360 if (found_start != start) {
361 WARN_ON(1);
362 goto err;
363 }
364 if (eb->first_page != page) {
365 WARN_ON(1);
366 goto err;
367 }
368 if (!PageUptodate(page)) {
369 WARN_ON(1);
370 goto err;
371 }
372 found_level = btrfs_header_level(eb);
373
374 csum_tree_block(root, eb, 0);
375 err:
376 free_extent_buffer(eb);
377 out:
378 return 0;
379 }
380
381 static int check_tree_block_fsid(struct btrfs_root *root,
382 struct extent_buffer *eb)
383 {
384 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
385 u8 fsid[BTRFS_UUID_SIZE];
386 int ret = 1;
387
388 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
389 BTRFS_FSID_SIZE);
390 while (fs_devices) {
391 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
392 ret = 0;
393 break;
394 }
395 fs_devices = fs_devices->seed;
396 }
397 return ret;
398 }
399
400 #ifdef CONFIG_DEBUG_LOCK_ALLOC
401 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
402 {
403 lockdep_set_class_and_name(&eb->lock,
404 &btrfs_eb_class[level],
405 btrfs_eb_name[level]);
406 }
407 #endif
408
409 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
410 struct extent_state *state)
411 {
412 struct extent_io_tree *tree;
413 u64 found_start;
414 int found_level;
415 unsigned long len;
416 struct extent_buffer *eb;
417 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
418 int ret = 0;
419
420 tree = &BTRFS_I(page->mapping->host)->io_tree;
421 if (page->private == EXTENT_PAGE_PRIVATE)
422 goto out;
423 if (!page->private)
424 goto out;
425
426 len = page->private >> 2;
427 WARN_ON(len == 0);
428
429 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
430
431 found_start = btrfs_header_bytenr(eb);
432 if (found_start != start) {
433 if (printk_ratelimit()) {
434 printk(KERN_INFO "btrfs bad tree block start "
435 "%llu %llu\n",
436 (unsigned long long)found_start,
437 (unsigned long long)eb->start);
438 }
439 ret = -EIO;
440 goto err;
441 }
442 if (eb->first_page != page) {
443 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
444 eb->first_page->index, page->index);
445 WARN_ON(1);
446 ret = -EIO;
447 goto err;
448 }
449 if (check_tree_block_fsid(root, eb)) {
450 if (printk_ratelimit()) {
451 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
452 (unsigned long long)eb->start);
453 }
454 ret = -EIO;
455 goto err;
456 }
457 found_level = btrfs_header_level(eb);
458
459 btrfs_set_buffer_lockdep_class(eb, found_level);
460
461 ret = csum_tree_block(root, eb, 1);
462 if (ret)
463 ret = -EIO;
464
465 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
466 end = eb->start + end - 1;
467 err:
468 free_extent_buffer(eb);
469 out:
470 return ret;
471 }
472
473 static void end_workqueue_bio(struct bio *bio, int err)
474 {
475 struct end_io_wq *end_io_wq = bio->bi_private;
476 struct btrfs_fs_info *fs_info;
477
478 fs_info = end_io_wq->info;
479 end_io_wq->error = err;
480 end_io_wq->work.func = end_workqueue_fn;
481 end_io_wq->work.flags = 0;
482
483 if (bio->bi_rw & REQ_WRITE) {
484 if (end_io_wq->metadata)
485 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
486 &end_io_wq->work);
487 else
488 btrfs_queue_worker(&fs_info->endio_write_workers,
489 &end_io_wq->work);
490 } else {
491 if (end_io_wq->metadata)
492 btrfs_queue_worker(&fs_info->endio_meta_workers,
493 &end_io_wq->work);
494 else
495 btrfs_queue_worker(&fs_info->endio_workers,
496 &end_io_wq->work);
497 }
498 }
499
500 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
501 int metadata)
502 {
503 struct end_io_wq *end_io_wq;
504 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
505 if (!end_io_wq)
506 return -ENOMEM;
507
508 end_io_wq->private = bio->bi_private;
509 end_io_wq->end_io = bio->bi_end_io;
510 end_io_wq->info = info;
511 end_io_wq->error = 0;
512 end_io_wq->bio = bio;
513 end_io_wq->metadata = metadata;
514
515 bio->bi_private = end_io_wq;
516 bio->bi_end_io = end_workqueue_bio;
517 return 0;
518 }
519
520 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
521 {
522 unsigned long limit = min_t(unsigned long,
523 info->workers.max_workers,
524 info->fs_devices->open_devices);
525 return 256 * limit;
526 }
527
528 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
529 {
530 return atomic_read(&info->nr_async_bios) >
531 btrfs_async_submit_limit(info);
532 }
533
534 static void run_one_async_start(struct btrfs_work *work)
535 {
536 struct btrfs_fs_info *fs_info;
537 struct async_submit_bio *async;
538
539 async = container_of(work, struct async_submit_bio, work);
540 fs_info = BTRFS_I(async->inode)->root->fs_info;
541 async->submit_bio_start(async->inode, async->rw, async->bio,
542 async->mirror_num, async->bio_flags,
543 async->bio_offset);
544 }
545
546 static void run_one_async_done(struct btrfs_work *work)
547 {
548 struct btrfs_fs_info *fs_info;
549 struct async_submit_bio *async;
550 int limit;
551
552 async = container_of(work, struct async_submit_bio, work);
553 fs_info = BTRFS_I(async->inode)->root->fs_info;
554
555 limit = btrfs_async_submit_limit(fs_info);
556 limit = limit * 2 / 3;
557
558 atomic_dec(&fs_info->nr_async_submits);
559
560 if (atomic_read(&fs_info->nr_async_submits) < limit &&
561 waitqueue_active(&fs_info->async_submit_wait))
562 wake_up(&fs_info->async_submit_wait);
563
564 async->submit_bio_done(async->inode, async->rw, async->bio,
565 async->mirror_num, async->bio_flags,
566 async->bio_offset);
567 }
568
569 static void run_one_async_free(struct btrfs_work *work)
570 {
571 struct async_submit_bio *async;
572
573 async = container_of(work, struct async_submit_bio, work);
574 kfree(async);
575 }
576
577 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
578 int rw, struct bio *bio, int mirror_num,
579 unsigned long bio_flags,
580 u64 bio_offset,
581 extent_submit_bio_hook_t *submit_bio_start,
582 extent_submit_bio_hook_t *submit_bio_done)
583 {
584 struct async_submit_bio *async;
585
586 async = kmalloc(sizeof(*async), GFP_NOFS);
587 if (!async)
588 return -ENOMEM;
589
590 async->inode = inode;
591 async->rw = rw;
592 async->bio = bio;
593 async->mirror_num = mirror_num;
594 async->submit_bio_start = submit_bio_start;
595 async->submit_bio_done = submit_bio_done;
596
597 async->work.func = run_one_async_start;
598 async->work.ordered_func = run_one_async_done;
599 async->work.ordered_free = run_one_async_free;
600
601 async->work.flags = 0;
602 async->bio_flags = bio_flags;
603 async->bio_offset = bio_offset;
604
605 atomic_inc(&fs_info->nr_async_submits);
606
607 if (rw & REQ_SYNC)
608 btrfs_set_work_high_prio(&async->work);
609
610 btrfs_queue_worker(&fs_info->workers, &async->work);
611
612 while (atomic_read(&fs_info->async_submit_draining) &&
613 atomic_read(&fs_info->nr_async_submits)) {
614 wait_event(fs_info->async_submit_wait,
615 (atomic_read(&fs_info->nr_async_submits) == 0));
616 }
617
618 return 0;
619 }
620
621 static int btree_csum_one_bio(struct bio *bio)
622 {
623 struct bio_vec *bvec = bio->bi_io_vec;
624 int bio_index = 0;
625 struct btrfs_root *root;
626
627 WARN_ON(bio->bi_vcnt <= 0);
628 while (bio_index < bio->bi_vcnt) {
629 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
630 csum_dirty_buffer(root, bvec->bv_page);
631 bio_index++;
632 bvec++;
633 }
634 return 0;
635 }
636
637 static int __btree_submit_bio_start(struct inode *inode, int rw,
638 struct bio *bio, int mirror_num,
639 unsigned long bio_flags,
640 u64 bio_offset)
641 {
642 /*
643 * when we're called for a write, we're already in the async
644 * submission context. Just jump into btrfs_map_bio
645 */
646 btree_csum_one_bio(bio);
647 return 0;
648 }
649
650 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
651 int mirror_num, unsigned long bio_flags,
652 u64 bio_offset)
653 {
654 /*
655 * when we're called for a write, we're already in the async
656 * submission context. Just jump into btrfs_map_bio
657 */
658 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
659 }
660
661 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
662 int mirror_num, unsigned long bio_flags,
663 u64 bio_offset)
664 {
665 int ret;
666
667 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
668 bio, 1);
669 BUG_ON(ret);
670
671 if (!(rw & REQ_WRITE)) {
672 /*
673 * called for a read, do the setup so that checksum validation
674 * can happen in the async kernel threads
675 */
676 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
677 mirror_num, 0);
678 }
679
680 /*
681 * kthread helpers are used to submit writes so that checksumming
682 * can happen in parallel across all CPUs
683 */
684 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
685 inode, rw, bio, mirror_num, 0,
686 bio_offset,
687 __btree_submit_bio_start,
688 __btree_submit_bio_done);
689 }
690
691 static int btree_writepage(struct page *page, struct writeback_control *wbc)
692 {
693 struct extent_io_tree *tree;
694 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
695 struct extent_buffer *eb;
696 int was_dirty;
697
698 tree = &BTRFS_I(page->mapping->host)->io_tree;
699 if (!(current->flags & PF_MEMALLOC)) {
700 return extent_write_full_page(tree, page,
701 btree_get_extent, wbc);
702 }
703
704 redirty_page_for_writepage(wbc, page);
705 eb = btrfs_find_tree_block(root, page_offset(page),
706 PAGE_CACHE_SIZE);
707 WARN_ON(!eb);
708
709 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
710 if (!was_dirty) {
711 spin_lock(&root->fs_info->delalloc_lock);
712 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
713 spin_unlock(&root->fs_info->delalloc_lock);
714 }
715 free_extent_buffer(eb);
716
717 unlock_page(page);
718 return 0;
719 }
720
721 static int btree_writepages(struct address_space *mapping,
722 struct writeback_control *wbc)
723 {
724 struct extent_io_tree *tree;
725 tree = &BTRFS_I(mapping->host)->io_tree;
726 if (wbc->sync_mode == WB_SYNC_NONE) {
727 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
728 u64 num_dirty;
729 unsigned long thresh = 32 * 1024 * 1024;
730
731 if (wbc->for_kupdate)
732 return 0;
733
734 /* this is a bit racy, but that's ok */
735 num_dirty = root->fs_info->dirty_metadata_bytes;
736 if (num_dirty < thresh)
737 return 0;
738 }
739 return extent_writepages(tree, mapping, btree_get_extent, wbc);
740 }
741
742 static int btree_readpage(struct file *file, struct page *page)
743 {
744 struct extent_io_tree *tree;
745 tree = &BTRFS_I(page->mapping->host)->io_tree;
746 return extent_read_full_page(tree, page, btree_get_extent);
747 }
748
749 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
750 {
751 struct extent_io_tree *tree;
752 struct extent_map_tree *map;
753 int ret;
754
755 if (PageWriteback(page) || PageDirty(page))
756 return 0;
757
758 tree = &BTRFS_I(page->mapping->host)->io_tree;
759 map = &BTRFS_I(page->mapping->host)->extent_tree;
760
761 ret = try_release_extent_state(map, tree, page, gfp_flags);
762 if (!ret)
763 return 0;
764
765 ret = try_release_extent_buffer(tree, page);
766 if (ret == 1) {
767 ClearPagePrivate(page);
768 set_page_private(page, 0);
769 page_cache_release(page);
770 }
771
772 return ret;
773 }
774
775 static void btree_invalidatepage(struct page *page, unsigned long offset)
776 {
777 struct extent_io_tree *tree;
778 tree = &BTRFS_I(page->mapping->host)->io_tree;
779 extent_invalidatepage(tree, page, offset);
780 btree_releasepage(page, GFP_NOFS);
781 if (PagePrivate(page)) {
782 printk(KERN_WARNING "btrfs warning page private not zero "
783 "on page %llu\n", (unsigned long long)page_offset(page));
784 ClearPagePrivate(page);
785 set_page_private(page, 0);
786 page_cache_release(page);
787 }
788 }
789
790 static const struct address_space_operations btree_aops = {
791 .readpage = btree_readpage,
792 .writepage = btree_writepage,
793 .writepages = btree_writepages,
794 .releasepage = btree_releasepage,
795 .invalidatepage = btree_invalidatepage,
796 .sync_page = block_sync_page,
797 };
798
799 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
800 u64 parent_transid)
801 {
802 struct extent_buffer *buf = NULL;
803 struct inode *btree_inode = root->fs_info->btree_inode;
804 int ret = 0;
805
806 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
807 if (!buf)
808 return 0;
809 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
810 buf, 0, 0, btree_get_extent, 0);
811 free_extent_buffer(buf);
812 return ret;
813 }
814
815 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
816 u64 bytenr, u32 blocksize)
817 {
818 struct inode *btree_inode = root->fs_info->btree_inode;
819 struct extent_buffer *eb;
820 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
821 bytenr, blocksize, GFP_NOFS);
822 return eb;
823 }
824
825 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
826 u64 bytenr, u32 blocksize)
827 {
828 struct inode *btree_inode = root->fs_info->btree_inode;
829 struct extent_buffer *eb;
830
831 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
832 bytenr, blocksize, NULL, GFP_NOFS);
833 return eb;
834 }
835
836
837 int btrfs_write_tree_block(struct extent_buffer *buf)
838 {
839 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
840 buf->start + buf->len - 1);
841 }
842
843 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
844 {
845 return filemap_fdatawait_range(buf->first_page->mapping,
846 buf->start, buf->start + buf->len - 1);
847 }
848
849 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
850 u32 blocksize, u64 parent_transid)
851 {
852 struct extent_buffer *buf = NULL;
853 struct inode *btree_inode = root->fs_info->btree_inode;
854 struct extent_io_tree *io_tree;
855 int ret;
856
857 io_tree = &BTRFS_I(btree_inode)->io_tree;
858
859 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
860 if (!buf)
861 return NULL;
862
863 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
864
865 if (ret == 0)
866 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
867 return buf;
868
869 }
870
871 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
872 struct extent_buffer *buf)
873 {
874 struct inode *btree_inode = root->fs_info->btree_inode;
875 if (btrfs_header_generation(buf) ==
876 root->fs_info->running_transaction->transid) {
877 btrfs_assert_tree_locked(buf);
878
879 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
880 spin_lock(&root->fs_info->delalloc_lock);
881 if (root->fs_info->dirty_metadata_bytes >= buf->len)
882 root->fs_info->dirty_metadata_bytes -= buf->len;
883 else
884 WARN_ON(1);
885 spin_unlock(&root->fs_info->delalloc_lock);
886 }
887
888 /* ugh, clear_extent_buffer_dirty needs to lock the page */
889 btrfs_set_lock_blocking(buf);
890 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
891 buf);
892 }
893 return 0;
894 }
895
896 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
897 u32 stripesize, struct btrfs_root *root,
898 struct btrfs_fs_info *fs_info,
899 u64 objectid)
900 {
901 root->node = NULL;
902 root->commit_root = NULL;
903 root->sectorsize = sectorsize;
904 root->nodesize = nodesize;
905 root->leafsize = leafsize;
906 root->stripesize = stripesize;
907 root->ref_cows = 0;
908 root->track_dirty = 0;
909 root->in_radix = 0;
910 root->orphan_item_inserted = 0;
911 root->orphan_cleanup_state = 0;
912
913 root->fs_info = fs_info;
914 root->objectid = objectid;
915 root->last_trans = 0;
916 root->highest_objectid = 0;
917 root->name = NULL;
918 root->in_sysfs = 0;
919 root->inode_tree = RB_ROOT;
920 root->block_rsv = NULL;
921 root->orphan_block_rsv = NULL;
922
923 INIT_LIST_HEAD(&root->dirty_list);
924 INIT_LIST_HEAD(&root->orphan_list);
925 INIT_LIST_HEAD(&root->root_list);
926 spin_lock_init(&root->node_lock);
927 spin_lock_init(&root->orphan_lock);
928 spin_lock_init(&root->inode_lock);
929 spin_lock_init(&root->accounting_lock);
930 mutex_init(&root->objectid_mutex);
931 mutex_init(&root->log_mutex);
932 init_waitqueue_head(&root->log_writer_wait);
933 init_waitqueue_head(&root->log_commit_wait[0]);
934 init_waitqueue_head(&root->log_commit_wait[1]);
935 atomic_set(&root->log_commit[0], 0);
936 atomic_set(&root->log_commit[1], 0);
937 atomic_set(&root->log_writers, 0);
938 root->log_batch = 0;
939 root->log_transid = 0;
940 root->last_log_commit = 0;
941 extent_io_tree_init(&root->dirty_log_pages,
942 fs_info->btree_inode->i_mapping, GFP_NOFS);
943
944 memset(&root->root_key, 0, sizeof(root->root_key));
945 memset(&root->root_item, 0, sizeof(root->root_item));
946 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
947 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
948 root->defrag_trans_start = fs_info->generation;
949 init_completion(&root->kobj_unregister);
950 root->defrag_running = 0;
951 root->root_key.objectid = objectid;
952 root->anon_super.s_root = NULL;
953 root->anon_super.s_dev = 0;
954 INIT_LIST_HEAD(&root->anon_super.s_list);
955 INIT_LIST_HEAD(&root->anon_super.s_instances);
956 init_rwsem(&root->anon_super.s_umount);
957
958 return 0;
959 }
960
961 static int find_and_setup_root(struct btrfs_root *tree_root,
962 struct btrfs_fs_info *fs_info,
963 u64 objectid,
964 struct btrfs_root *root)
965 {
966 int ret;
967 u32 blocksize;
968 u64 generation;
969
970 __setup_root(tree_root->nodesize, tree_root->leafsize,
971 tree_root->sectorsize, tree_root->stripesize,
972 root, fs_info, objectid);
973 ret = btrfs_find_last_root(tree_root, objectid,
974 &root->root_item, &root->root_key);
975 if (ret > 0)
976 return -ENOENT;
977 BUG_ON(ret);
978
979 generation = btrfs_root_generation(&root->root_item);
980 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
981 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
982 blocksize, generation);
983 BUG_ON(!root->node);
984 root->commit_root = btrfs_root_node(root);
985 return 0;
986 }
987
988 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
989 struct btrfs_fs_info *fs_info)
990 {
991 struct btrfs_root *root;
992 struct btrfs_root *tree_root = fs_info->tree_root;
993 struct extent_buffer *leaf;
994
995 root = kzalloc(sizeof(*root), GFP_NOFS);
996 if (!root)
997 return ERR_PTR(-ENOMEM);
998
999 __setup_root(tree_root->nodesize, tree_root->leafsize,
1000 tree_root->sectorsize, tree_root->stripesize,
1001 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1002
1003 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1004 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1005 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1006 /*
1007 * log trees do not get reference counted because they go away
1008 * before a real commit is actually done. They do store pointers
1009 * to file data extents, and those reference counts still get
1010 * updated (along with back refs to the log tree).
1011 */
1012 root->ref_cows = 0;
1013
1014 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1015 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1016 if (IS_ERR(leaf)) {
1017 kfree(root);
1018 return ERR_CAST(leaf);
1019 }
1020
1021 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1022 btrfs_set_header_bytenr(leaf, leaf->start);
1023 btrfs_set_header_generation(leaf, trans->transid);
1024 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1025 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1026 root->node = leaf;
1027
1028 write_extent_buffer(root->node, root->fs_info->fsid,
1029 (unsigned long)btrfs_header_fsid(root->node),
1030 BTRFS_FSID_SIZE);
1031 btrfs_mark_buffer_dirty(root->node);
1032 btrfs_tree_unlock(root->node);
1033 return root;
1034 }
1035
1036 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1037 struct btrfs_fs_info *fs_info)
1038 {
1039 struct btrfs_root *log_root;
1040
1041 log_root = alloc_log_tree(trans, fs_info);
1042 if (IS_ERR(log_root))
1043 return PTR_ERR(log_root);
1044 WARN_ON(fs_info->log_root_tree);
1045 fs_info->log_root_tree = log_root;
1046 return 0;
1047 }
1048
1049 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1050 struct btrfs_root *root)
1051 {
1052 struct btrfs_root *log_root;
1053 struct btrfs_inode_item *inode_item;
1054
1055 log_root = alloc_log_tree(trans, root->fs_info);
1056 if (IS_ERR(log_root))
1057 return PTR_ERR(log_root);
1058
1059 log_root->last_trans = trans->transid;
1060 log_root->root_key.offset = root->root_key.objectid;
1061
1062 inode_item = &log_root->root_item.inode;
1063 inode_item->generation = cpu_to_le64(1);
1064 inode_item->size = cpu_to_le64(3);
1065 inode_item->nlink = cpu_to_le32(1);
1066 inode_item->nbytes = cpu_to_le64(root->leafsize);
1067 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1068
1069 btrfs_set_root_node(&log_root->root_item, log_root->node);
1070
1071 WARN_ON(root->log_root);
1072 root->log_root = log_root;
1073 root->log_transid = 0;
1074 root->last_log_commit = 0;
1075 return 0;
1076 }
1077
1078 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1079 struct btrfs_key *location)
1080 {
1081 struct btrfs_root *root;
1082 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1083 struct btrfs_path *path;
1084 struct extent_buffer *l;
1085 u64 generation;
1086 u32 blocksize;
1087 int ret = 0;
1088
1089 root = kzalloc(sizeof(*root), GFP_NOFS);
1090 if (!root)
1091 return ERR_PTR(-ENOMEM);
1092 if (location->offset == (u64)-1) {
1093 ret = find_and_setup_root(tree_root, fs_info,
1094 location->objectid, root);
1095 if (ret) {
1096 kfree(root);
1097 return ERR_PTR(ret);
1098 }
1099 goto out;
1100 }
1101
1102 __setup_root(tree_root->nodesize, tree_root->leafsize,
1103 tree_root->sectorsize, tree_root->stripesize,
1104 root, fs_info, location->objectid);
1105
1106 path = btrfs_alloc_path();
1107 BUG_ON(!path);
1108 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1109 if (ret == 0) {
1110 l = path->nodes[0];
1111 read_extent_buffer(l, &root->root_item,
1112 btrfs_item_ptr_offset(l, path->slots[0]),
1113 sizeof(root->root_item));
1114 memcpy(&root->root_key, location, sizeof(*location));
1115 }
1116 btrfs_free_path(path);
1117 if (ret) {
1118 if (ret > 0)
1119 ret = -ENOENT;
1120 return ERR_PTR(ret);
1121 }
1122
1123 generation = btrfs_root_generation(&root->root_item);
1124 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1125 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1126 blocksize, generation);
1127 root->commit_root = btrfs_root_node(root);
1128 BUG_ON(!root->node);
1129 out:
1130 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1131 root->ref_cows = 1;
1132
1133 return root;
1134 }
1135
1136 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1137 u64 root_objectid)
1138 {
1139 struct btrfs_root *root;
1140
1141 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1142 return fs_info->tree_root;
1143 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1144 return fs_info->extent_root;
1145
1146 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1147 (unsigned long)root_objectid);
1148 return root;
1149 }
1150
1151 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1152 struct btrfs_key *location)
1153 {
1154 struct btrfs_root *root;
1155 int ret;
1156
1157 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1158 return fs_info->tree_root;
1159 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1160 return fs_info->extent_root;
1161 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1162 return fs_info->chunk_root;
1163 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1164 return fs_info->dev_root;
1165 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1166 return fs_info->csum_root;
1167 again:
1168 spin_lock(&fs_info->fs_roots_radix_lock);
1169 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1170 (unsigned long)location->objectid);
1171 spin_unlock(&fs_info->fs_roots_radix_lock);
1172 if (root)
1173 return root;
1174
1175 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1176 if (IS_ERR(root))
1177 return root;
1178
1179 set_anon_super(&root->anon_super, NULL);
1180
1181 if (btrfs_root_refs(&root->root_item) == 0) {
1182 ret = -ENOENT;
1183 goto fail;
1184 }
1185
1186 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1187 if (ret < 0)
1188 goto fail;
1189 if (ret == 0)
1190 root->orphan_item_inserted = 1;
1191
1192 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1193 if (ret)
1194 goto fail;
1195
1196 spin_lock(&fs_info->fs_roots_radix_lock);
1197 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1198 (unsigned long)root->root_key.objectid,
1199 root);
1200 if (ret == 0)
1201 root->in_radix = 1;
1202
1203 spin_unlock(&fs_info->fs_roots_radix_lock);
1204 radix_tree_preload_end();
1205 if (ret) {
1206 if (ret == -EEXIST) {
1207 free_fs_root(root);
1208 goto again;
1209 }
1210 goto fail;
1211 }
1212
1213 ret = btrfs_find_dead_roots(fs_info->tree_root,
1214 root->root_key.objectid);
1215 WARN_ON(ret);
1216 return root;
1217 fail:
1218 free_fs_root(root);
1219 return ERR_PTR(ret);
1220 }
1221
1222 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1223 struct btrfs_key *location,
1224 const char *name, int namelen)
1225 {
1226 return btrfs_read_fs_root_no_name(fs_info, location);
1227 #if 0
1228 struct btrfs_root *root;
1229 int ret;
1230
1231 root = btrfs_read_fs_root_no_name(fs_info, location);
1232 if (!root)
1233 return NULL;
1234
1235 if (root->in_sysfs)
1236 return root;
1237
1238 ret = btrfs_set_root_name(root, name, namelen);
1239 if (ret) {
1240 free_extent_buffer(root->node);
1241 kfree(root);
1242 return ERR_PTR(ret);
1243 }
1244
1245 ret = btrfs_sysfs_add_root(root);
1246 if (ret) {
1247 free_extent_buffer(root->node);
1248 kfree(root->name);
1249 kfree(root);
1250 return ERR_PTR(ret);
1251 }
1252 root->in_sysfs = 1;
1253 return root;
1254 #endif
1255 }
1256
1257 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1258 {
1259 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1260 int ret = 0;
1261 struct btrfs_device *device;
1262 struct backing_dev_info *bdi;
1263
1264 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1265 if (!device->bdev)
1266 continue;
1267 bdi = blk_get_backing_dev_info(device->bdev);
1268 if (bdi && bdi_congested(bdi, bdi_bits)) {
1269 ret = 1;
1270 break;
1271 }
1272 }
1273 return ret;
1274 }
1275
1276 /*
1277 * this unplugs every device on the box, and it is only used when page
1278 * is null
1279 */
1280 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1281 {
1282 struct btrfs_device *device;
1283 struct btrfs_fs_info *info;
1284
1285 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1286 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1287 if (!device->bdev)
1288 continue;
1289
1290 bdi = blk_get_backing_dev_info(device->bdev);
1291 if (bdi->unplug_io_fn)
1292 bdi->unplug_io_fn(bdi, page);
1293 }
1294 }
1295
1296 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1297 {
1298 struct inode *inode;
1299 struct extent_map_tree *em_tree;
1300 struct extent_map *em;
1301 struct address_space *mapping;
1302 u64 offset;
1303
1304 /* the generic O_DIRECT read code does this */
1305 if (1 || !page) {
1306 __unplug_io_fn(bdi, page);
1307 return;
1308 }
1309
1310 /*
1311 * page->mapping may change at any time. Get a consistent copy
1312 * and use that for everything below
1313 */
1314 smp_mb();
1315 mapping = page->mapping;
1316 if (!mapping)
1317 return;
1318
1319 inode = mapping->host;
1320
1321 /*
1322 * don't do the expensive searching for a small number of
1323 * devices
1324 */
1325 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1326 __unplug_io_fn(bdi, page);
1327 return;
1328 }
1329
1330 offset = page_offset(page);
1331
1332 em_tree = &BTRFS_I(inode)->extent_tree;
1333 read_lock(&em_tree->lock);
1334 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1335 read_unlock(&em_tree->lock);
1336 if (!em) {
1337 __unplug_io_fn(bdi, page);
1338 return;
1339 }
1340
1341 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1342 free_extent_map(em);
1343 __unplug_io_fn(bdi, page);
1344 return;
1345 }
1346 offset = offset - em->start;
1347 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1348 em->block_start + offset, page);
1349 free_extent_map(em);
1350 }
1351
1352 /*
1353 * If this fails, caller must call bdi_destroy() to get rid of the
1354 * bdi again.
1355 */
1356 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1357 {
1358 int err;
1359
1360 bdi->capabilities = BDI_CAP_MAP_COPY;
1361 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1362 if (err)
1363 return err;
1364
1365 bdi->ra_pages = default_backing_dev_info.ra_pages;
1366 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1367 bdi->unplug_io_data = info;
1368 bdi->congested_fn = btrfs_congested_fn;
1369 bdi->congested_data = info;
1370 return 0;
1371 }
1372
1373 static int bio_ready_for_csum(struct bio *bio)
1374 {
1375 u64 length = 0;
1376 u64 buf_len = 0;
1377 u64 start = 0;
1378 struct page *page;
1379 struct extent_io_tree *io_tree = NULL;
1380 struct btrfs_fs_info *info = NULL;
1381 struct bio_vec *bvec;
1382 int i;
1383 int ret;
1384
1385 bio_for_each_segment(bvec, bio, i) {
1386 page = bvec->bv_page;
1387 if (page->private == EXTENT_PAGE_PRIVATE) {
1388 length += bvec->bv_len;
1389 continue;
1390 }
1391 if (!page->private) {
1392 length += bvec->bv_len;
1393 continue;
1394 }
1395 length = bvec->bv_len;
1396 buf_len = page->private >> 2;
1397 start = page_offset(page) + bvec->bv_offset;
1398 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1399 info = BTRFS_I(page->mapping->host)->root->fs_info;
1400 }
1401 /* are we fully contained in this bio? */
1402 if (buf_len <= length)
1403 return 1;
1404
1405 ret = extent_range_uptodate(io_tree, start + length,
1406 start + buf_len - 1);
1407 return ret;
1408 }
1409
1410 /*
1411 * called by the kthread helper functions to finally call the bio end_io
1412 * functions. This is where read checksum verification actually happens
1413 */
1414 static void end_workqueue_fn(struct btrfs_work *work)
1415 {
1416 struct bio *bio;
1417 struct end_io_wq *end_io_wq;
1418 struct btrfs_fs_info *fs_info;
1419 int error;
1420
1421 end_io_wq = container_of(work, struct end_io_wq, work);
1422 bio = end_io_wq->bio;
1423 fs_info = end_io_wq->info;
1424
1425 /* metadata bio reads are special because the whole tree block must
1426 * be checksummed at once. This makes sure the entire block is in
1427 * ram and up to date before trying to verify things. For
1428 * blocksize <= pagesize, it is basically a noop
1429 */
1430 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1431 !bio_ready_for_csum(bio)) {
1432 btrfs_queue_worker(&fs_info->endio_meta_workers,
1433 &end_io_wq->work);
1434 return;
1435 }
1436 error = end_io_wq->error;
1437 bio->bi_private = end_io_wq->private;
1438 bio->bi_end_io = end_io_wq->end_io;
1439 kfree(end_io_wq);
1440 bio_endio(bio, error);
1441 }
1442
1443 static int cleaner_kthread(void *arg)
1444 {
1445 struct btrfs_root *root = arg;
1446
1447 do {
1448 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1449
1450 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1451 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1452 btrfs_run_delayed_iputs(root);
1453 btrfs_clean_old_snapshots(root);
1454 mutex_unlock(&root->fs_info->cleaner_mutex);
1455 }
1456
1457 if (freezing(current)) {
1458 refrigerator();
1459 } else {
1460 set_current_state(TASK_INTERRUPTIBLE);
1461 if (!kthread_should_stop())
1462 schedule();
1463 __set_current_state(TASK_RUNNING);
1464 }
1465 } while (!kthread_should_stop());
1466 return 0;
1467 }
1468
1469 static int transaction_kthread(void *arg)
1470 {
1471 struct btrfs_root *root = arg;
1472 struct btrfs_trans_handle *trans;
1473 struct btrfs_transaction *cur;
1474 u64 transid;
1475 unsigned long now;
1476 unsigned long delay;
1477 int ret;
1478
1479 do {
1480 delay = HZ * 30;
1481 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1482 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1483
1484 spin_lock(&root->fs_info->new_trans_lock);
1485 cur = root->fs_info->running_transaction;
1486 if (!cur) {
1487 spin_unlock(&root->fs_info->new_trans_lock);
1488 goto sleep;
1489 }
1490
1491 now = get_seconds();
1492 if (!cur->blocked &&
1493 (now < cur->start_time || now - cur->start_time < 30)) {
1494 spin_unlock(&root->fs_info->new_trans_lock);
1495 delay = HZ * 5;
1496 goto sleep;
1497 }
1498 transid = cur->transid;
1499 spin_unlock(&root->fs_info->new_trans_lock);
1500
1501 trans = btrfs_join_transaction(root, 1);
1502 if (transid == trans->transid) {
1503 ret = btrfs_commit_transaction(trans, root);
1504 BUG_ON(ret);
1505 } else {
1506 btrfs_end_transaction(trans, root);
1507 }
1508 sleep:
1509 wake_up_process(root->fs_info->cleaner_kthread);
1510 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1511
1512 if (freezing(current)) {
1513 refrigerator();
1514 } else {
1515 set_current_state(TASK_INTERRUPTIBLE);
1516 if (!kthread_should_stop() &&
1517 !btrfs_transaction_blocked(root->fs_info))
1518 schedule_timeout(delay);
1519 __set_current_state(TASK_RUNNING);
1520 }
1521 } while (!kthread_should_stop());
1522 return 0;
1523 }
1524
1525 struct btrfs_root *open_ctree(struct super_block *sb,
1526 struct btrfs_fs_devices *fs_devices,
1527 char *options)
1528 {
1529 u32 sectorsize;
1530 u32 nodesize;
1531 u32 leafsize;
1532 u32 blocksize;
1533 u32 stripesize;
1534 u64 generation;
1535 u64 features;
1536 struct btrfs_key location;
1537 struct buffer_head *bh;
1538 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1539 GFP_NOFS);
1540 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1541 GFP_NOFS);
1542 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1543 GFP_NOFS);
1544 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1545 GFP_NOFS);
1546 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1547 GFP_NOFS);
1548 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1549 GFP_NOFS);
1550 struct btrfs_root *log_tree_root;
1551
1552 int ret;
1553 int err = -EINVAL;
1554
1555 struct btrfs_super_block *disk_super;
1556
1557 if (!extent_root || !tree_root || !fs_info ||
1558 !chunk_root || !dev_root || !csum_root) {
1559 err = -ENOMEM;
1560 goto fail;
1561 }
1562
1563 ret = init_srcu_struct(&fs_info->subvol_srcu);
1564 if (ret) {
1565 err = ret;
1566 goto fail;
1567 }
1568
1569 ret = setup_bdi(fs_info, &fs_info->bdi);
1570 if (ret) {
1571 err = ret;
1572 goto fail_srcu;
1573 }
1574
1575 fs_info->btree_inode = new_inode(sb);
1576 if (!fs_info->btree_inode) {
1577 err = -ENOMEM;
1578 goto fail_bdi;
1579 }
1580
1581 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1582 INIT_LIST_HEAD(&fs_info->trans_list);
1583 INIT_LIST_HEAD(&fs_info->dead_roots);
1584 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1585 INIT_LIST_HEAD(&fs_info->hashers);
1586 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1587 INIT_LIST_HEAD(&fs_info->ordered_operations);
1588 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1589 spin_lock_init(&fs_info->delalloc_lock);
1590 spin_lock_init(&fs_info->new_trans_lock);
1591 spin_lock_init(&fs_info->ref_cache_lock);
1592 spin_lock_init(&fs_info->fs_roots_radix_lock);
1593 spin_lock_init(&fs_info->delayed_iput_lock);
1594
1595 init_completion(&fs_info->kobj_unregister);
1596 fs_info->tree_root = tree_root;
1597 fs_info->extent_root = extent_root;
1598 fs_info->csum_root = csum_root;
1599 fs_info->chunk_root = chunk_root;
1600 fs_info->dev_root = dev_root;
1601 fs_info->fs_devices = fs_devices;
1602 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1603 INIT_LIST_HEAD(&fs_info->space_info);
1604 btrfs_mapping_init(&fs_info->mapping_tree);
1605 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1606 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1607 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1608 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1609 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1610 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1611 mutex_init(&fs_info->durable_block_rsv_mutex);
1612 atomic_set(&fs_info->nr_async_submits, 0);
1613 atomic_set(&fs_info->async_delalloc_pages, 0);
1614 atomic_set(&fs_info->async_submit_draining, 0);
1615 atomic_set(&fs_info->nr_async_bios, 0);
1616 fs_info->sb = sb;
1617 fs_info->max_inline = 8192 * 1024;
1618 fs_info->metadata_ratio = 0;
1619
1620 fs_info->thread_pool_size = min_t(unsigned long,
1621 num_online_cpus() + 2, 8);
1622
1623 INIT_LIST_HEAD(&fs_info->ordered_extents);
1624 spin_lock_init(&fs_info->ordered_extent_lock);
1625
1626 sb->s_blocksize = 4096;
1627 sb->s_blocksize_bits = blksize_bits(4096);
1628 sb->s_bdi = &fs_info->bdi;
1629
1630 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1631 fs_info->btree_inode->i_nlink = 1;
1632 /*
1633 * we set the i_size on the btree inode to the max possible int.
1634 * the real end of the address space is determined by all of
1635 * the devices in the system
1636 */
1637 fs_info->btree_inode->i_size = OFFSET_MAX;
1638 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1639 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1640
1641 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1642 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1643 fs_info->btree_inode->i_mapping,
1644 GFP_NOFS);
1645 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1646 GFP_NOFS);
1647
1648 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1649
1650 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1651 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1652 sizeof(struct btrfs_key));
1653 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1654 insert_inode_hash(fs_info->btree_inode);
1655
1656 spin_lock_init(&fs_info->block_group_cache_lock);
1657 fs_info->block_group_cache_tree = RB_ROOT;
1658
1659 extent_io_tree_init(&fs_info->freed_extents[0],
1660 fs_info->btree_inode->i_mapping, GFP_NOFS);
1661 extent_io_tree_init(&fs_info->freed_extents[1],
1662 fs_info->btree_inode->i_mapping, GFP_NOFS);
1663 fs_info->pinned_extents = &fs_info->freed_extents[0];
1664 fs_info->do_barriers = 1;
1665
1666
1667 mutex_init(&fs_info->trans_mutex);
1668 mutex_init(&fs_info->ordered_operations_mutex);
1669 mutex_init(&fs_info->tree_log_mutex);
1670 mutex_init(&fs_info->chunk_mutex);
1671 mutex_init(&fs_info->transaction_kthread_mutex);
1672 mutex_init(&fs_info->cleaner_mutex);
1673 mutex_init(&fs_info->volume_mutex);
1674 init_rwsem(&fs_info->extent_commit_sem);
1675 init_rwsem(&fs_info->cleanup_work_sem);
1676 init_rwsem(&fs_info->subvol_sem);
1677
1678 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1679 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1680
1681 init_waitqueue_head(&fs_info->transaction_throttle);
1682 init_waitqueue_head(&fs_info->transaction_wait);
1683 init_waitqueue_head(&fs_info->async_submit_wait);
1684
1685 __setup_root(4096, 4096, 4096, 4096, tree_root,
1686 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1687
1688
1689 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1690 if (!bh)
1691 goto fail_iput;
1692
1693 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1694 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1695 sizeof(fs_info->super_for_commit));
1696 brelse(bh);
1697
1698 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1699
1700 disk_super = &fs_info->super_copy;
1701 if (!btrfs_super_root(disk_super))
1702 goto fail_iput;
1703
1704 ret = btrfs_parse_options(tree_root, options);
1705 if (ret) {
1706 err = ret;
1707 goto fail_iput;
1708 }
1709
1710 features = btrfs_super_incompat_flags(disk_super) &
1711 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1712 if (features) {
1713 printk(KERN_ERR "BTRFS: couldn't mount because of "
1714 "unsupported optional features (%Lx).\n",
1715 (unsigned long long)features);
1716 err = -EINVAL;
1717 goto fail_iput;
1718 }
1719
1720 features = btrfs_super_incompat_flags(disk_super);
1721 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1722 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1723 btrfs_set_super_incompat_flags(disk_super, features);
1724 }
1725
1726 features = btrfs_super_compat_ro_flags(disk_super) &
1727 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1728 if (!(sb->s_flags & MS_RDONLY) && features) {
1729 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1730 "unsupported option features (%Lx).\n",
1731 (unsigned long long)features);
1732 err = -EINVAL;
1733 goto fail_iput;
1734 }
1735
1736 btrfs_init_workers(&fs_info->generic_worker,
1737 "genwork", 1, NULL);
1738
1739 btrfs_init_workers(&fs_info->workers, "worker",
1740 fs_info->thread_pool_size,
1741 &fs_info->generic_worker);
1742
1743 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1744 fs_info->thread_pool_size,
1745 &fs_info->generic_worker);
1746
1747 btrfs_init_workers(&fs_info->submit_workers, "submit",
1748 min_t(u64, fs_devices->num_devices,
1749 fs_info->thread_pool_size),
1750 &fs_info->generic_worker);
1751
1752 /* a higher idle thresh on the submit workers makes it much more
1753 * likely that bios will be send down in a sane order to the
1754 * devices
1755 */
1756 fs_info->submit_workers.idle_thresh = 64;
1757
1758 fs_info->workers.idle_thresh = 16;
1759 fs_info->workers.ordered = 1;
1760
1761 fs_info->delalloc_workers.idle_thresh = 2;
1762 fs_info->delalloc_workers.ordered = 1;
1763
1764 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1765 &fs_info->generic_worker);
1766 btrfs_init_workers(&fs_info->endio_workers, "endio",
1767 fs_info->thread_pool_size,
1768 &fs_info->generic_worker);
1769 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1770 fs_info->thread_pool_size,
1771 &fs_info->generic_worker);
1772 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1773 "endio-meta-write", fs_info->thread_pool_size,
1774 &fs_info->generic_worker);
1775 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1776 fs_info->thread_pool_size,
1777 &fs_info->generic_worker);
1778
1779 /*
1780 * endios are largely parallel and should have a very
1781 * low idle thresh
1782 */
1783 fs_info->endio_workers.idle_thresh = 4;
1784 fs_info->endio_meta_workers.idle_thresh = 4;
1785
1786 fs_info->endio_write_workers.idle_thresh = 2;
1787 fs_info->endio_meta_write_workers.idle_thresh = 2;
1788
1789 btrfs_start_workers(&fs_info->workers, 1);
1790 btrfs_start_workers(&fs_info->generic_worker, 1);
1791 btrfs_start_workers(&fs_info->submit_workers, 1);
1792 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1793 btrfs_start_workers(&fs_info->fixup_workers, 1);
1794 btrfs_start_workers(&fs_info->endio_workers, 1);
1795 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1796 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1797 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1798
1799 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1800 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1801 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1802
1803 nodesize = btrfs_super_nodesize(disk_super);
1804 leafsize = btrfs_super_leafsize(disk_super);
1805 sectorsize = btrfs_super_sectorsize(disk_super);
1806 stripesize = btrfs_super_stripesize(disk_super);
1807 tree_root->nodesize = nodesize;
1808 tree_root->leafsize = leafsize;
1809 tree_root->sectorsize = sectorsize;
1810 tree_root->stripesize = stripesize;
1811
1812 sb->s_blocksize = sectorsize;
1813 sb->s_blocksize_bits = blksize_bits(sectorsize);
1814
1815 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1816 sizeof(disk_super->magic))) {
1817 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1818 goto fail_sb_buffer;
1819 }
1820
1821 mutex_lock(&fs_info->chunk_mutex);
1822 ret = btrfs_read_sys_array(tree_root);
1823 mutex_unlock(&fs_info->chunk_mutex);
1824 if (ret) {
1825 printk(KERN_WARNING "btrfs: failed to read the system "
1826 "array on %s\n", sb->s_id);
1827 goto fail_sb_buffer;
1828 }
1829
1830 blocksize = btrfs_level_size(tree_root,
1831 btrfs_super_chunk_root_level(disk_super));
1832 generation = btrfs_super_chunk_root_generation(disk_super);
1833
1834 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1835 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1836
1837 chunk_root->node = read_tree_block(chunk_root,
1838 btrfs_super_chunk_root(disk_super),
1839 blocksize, generation);
1840 BUG_ON(!chunk_root->node);
1841 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1842 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1843 sb->s_id);
1844 goto fail_chunk_root;
1845 }
1846 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1847 chunk_root->commit_root = btrfs_root_node(chunk_root);
1848
1849 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1850 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1851 BTRFS_UUID_SIZE);
1852
1853 mutex_lock(&fs_info->chunk_mutex);
1854 ret = btrfs_read_chunk_tree(chunk_root);
1855 mutex_unlock(&fs_info->chunk_mutex);
1856 if (ret) {
1857 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1858 sb->s_id);
1859 goto fail_chunk_root;
1860 }
1861
1862 btrfs_close_extra_devices(fs_devices);
1863
1864 blocksize = btrfs_level_size(tree_root,
1865 btrfs_super_root_level(disk_super));
1866 generation = btrfs_super_generation(disk_super);
1867
1868 tree_root->node = read_tree_block(tree_root,
1869 btrfs_super_root(disk_super),
1870 blocksize, generation);
1871 if (!tree_root->node)
1872 goto fail_chunk_root;
1873 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1874 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1875 sb->s_id);
1876 goto fail_tree_root;
1877 }
1878 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1879 tree_root->commit_root = btrfs_root_node(tree_root);
1880
1881 ret = find_and_setup_root(tree_root, fs_info,
1882 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1883 if (ret)
1884 goto fail_tree_root;
1885 extent_root->track_dirty = 1;
1886
1887 ret = find_and_setup_root(tree_root, fs_info,
1888 BTRFS_DEV_TREE_OBJECTID, dev_root);
1889 if (ret)
1890 goto fail_extent_root;
1891 dev_root->track_dirty = 1;
1892
1893 ret = find_and_setup_root(tree_root, fs_info,
1894 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1895 if (ret)
1896 goto fail_dev_root;
1897
1898 csum_root->track_dirty = 1;
1899
1900 fs_info->generation = generation;
1901 fs_info->last_trans_committed = generation;
1902 fs_info->data_alloc_profile = (u64)-1;
1903 fs_info->metadata_alloc_profile = (u64)-1;
1904 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1905
1906 ret = btrfs_read_block_groups(extent_root);
1907 if (ret) {
1908 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1909 goto fail_block_groups;
1910 }
1911
1912 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1913 "btrfs-cleaner");
1914 if (IS_ERR(fs_info->cleaner_kthread))
1915 goto fail_block_groups;
1916
1917 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1918 tree_root,
1919 "btrfs-transaction");
1920 if (IS_ERR(fs_info->transaction_kthread))
1921 goto fail_cleaner;
1922
1923 if (!btrfs_test_opt(tree_root, SSD) &&
1924 !btrfs_test_opt(tree_root, NOSSD) &&
1925 !fs_info->fs_devices->rotating) {
1926 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1927 "mode\n");
1928 btrfs_set_opt(fs_info->mount_opt, SSD);
1929 }
1930
1931 if (btrfs_super_log_root(disk_super) != 0) {
1932 u64 bytenr = btrfs_super_log_root(disk_super);
1933
1934 if (fs_devices->rw_devices == 0) {
1935 printk(KERN_WARNING "Btrfs log replay required "
1936 "on RO media\n");
1937 err = -EIO;
1938 goto fail_trans_kthread;
1939 }
1940 blocksize =
1941 btrfs_level_size(tree_root,
1942 btrfs_super_log_root_level(disk_super));
1943
1944 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1945 if (!log_tree_root) {
1946 err = -ENOMEM;
1947 goto fail_trans_kthread;
1948 }
1949
1950 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1951 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1952
1953 log_tree_root->node = read_tree_block(tree_root, bytenr,
1954 blocksize,
1955 generation + 1);
1956 ret = btrfs_recover_log_trees(log_tree_root);
1957 BUG_ON(ret);
1958
1959 if (sb->s_flags & MS_RDONLY) {
1960 ret = btrfs_commit_super(tree_root);
1961 BUG_ON(ret);
1962 }
1963 }
1964
1965 ret = btrfs_find_orphan_roots(tree_root);
1966 BUG_ON(ret);
1967
1968 if (!(sb->s_flags & MS_RDONLY)) {
1969 ret = btrfs_cleanup_fs_roots(fs_info);
1970 BUG_ON(ret);
1971
1972 ret = btrfs_recover_relocation(tree_root);
1973 if (ret < 0) {
1974 printk(KERN_WARNING
1975 "btrfs: failed to recover relocation\n");
1976 err = -EINVAL;
1977 goto fail_trans_kthread;
1978 }
1979 }
1980
1981 location.objectid = BTRFS_FS_TREE_OBJECTID;
1982 location.type = BTRFS_ROOT_ITEM_KEY;
1983 location.offset = (u64)-1;
1984
1985 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1986 if (!fs_info->fs_root)
1987 goto fail_trans_kthread;
1988 if (IS_ERR(fs_info->fs_root)) {
1989 err = PTR_ERR(fs_info->fs_root);
1990 goto fail_trans_kthread;
1991 }
1992
1993 if (!(sb->s_flags & MS_RDONLY)) {
1994 down_read(&fs_info->cleanup_work_sem);
1995 btrfs_orphan_cleanup(fs_info->fs_root);
1996 up_read(&fs_info->cleanup_work_sem);
1997 }
1998
1999 return tree_root;
2000
2001 fail_trans_kthread:
2002 kthread_stop(fs_info->transaction_kthread);
2003 fail_cleaner:
2004 kthread_stop(fs_info->cleaner_kthread);
2005
2006 /*
2007 * make sure we're done with the btree inode before we stop our
2008 * kthreads
2009 */
2010 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2011 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2012
2013 fail_block_groups:
2014 btrfs_free_block_groups(fs_info);
2015 free_extent_buffer(csum_root->node);
2016 free_extent_buffer(csum_root->commit_root);
2017 fail_dev_root:
2018 free_extent_buffer(dev_root->node);
2019 free_extent_buffer(dev_root->commit_root);
2020 fail_extent_root:
2021 free_extent_buffer(extent_root->node);
2022 free_extent_buffer(extent_root->commit_root);
2023 fail_tree_root:
2024 free_extent_buffer(tree_root->node);
2025 free_extent_buffer(tree_root->commit_root);
2026 fail_chunk_root:
2027 free_extent_buffer(chunk_root->node);
2028 free_extent_buffer(chunk_root->commit_root);
2029 fail_sb_buffer:
2030 btrfs_stop_workers(&fs_info->generic_worker);
2031 btrfs_stop_workers(&fs_info->fixup_workers);
2032 btrfs_stop_workers(&fs_info->delalloc_workers);
2033 btrfs_stop_workers(&fs_info->workers);
2034 btrfs_stop_workers(&fs_info->endio_workers);
2035 btrfs_stop_workers(&fs_info->endio_meta_workers);
2036 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2037 btrfs_stop_workers(&fs_info->endio_write_workers);
2038 btrfs_stop_workers(&fs_info->submit_workers);
2039 fail_iput:
2040 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2041 iput(fs_info->btree_inode);
2042
2043 btrfs_close_devices(fs_info->fs_devices);
2044 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2045 fail_bdi:
2046 bdi_destroy(&fs_info->bdi);
2047 fail_srcu:
2048 cleanup_srcu_struct(&fs_info->subvol_srcu);
2049 fail:
2050 kfree(extent_root);
2051 kfree(tree_root);
2052 kfree(fs_info);
2053 kfree(chunk_root);
2054 kfree(dev_root);
2055 kfree(csum_root);
2056 return ERR_PTR(err);
2057 }
2058
2059 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2060 {
2061 char b[BDEVNAME_SIZE];
2062
2063 if (uptodate) {
2064 set_buffer_uptodate(bh);
2065 } else {
2066 if (printk_ratelimit()) {
2067 printk(KERN_WARNING "lost page write due to "
2068 "I/O error on %s\n",
2069 bdevname(bh->b_bdev, b));
2070 }
2071 /* note, we dont' set_buffer_write_io_error because we have
2072 * our own ways of dealing with the IO errors
2073 */
2074 clear_buffer_uptodate(bh);
2075 }
2076 unlock_buffer(bh);
2077 put_bh(bh);
2078 }
2079
2080 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2081 {
2082 struct buffer_head *bh;
2083 struct buffer_head *latest = NULL;
2084 struct btrfs_super_block *super;
2085 int i;
2086 u64 transid = 0;
2087 u64 bytenr;
2088
2089 /* we would like to check all the supers, but that would make
2090 * a btrfs mount succeed after a mkfs from a different FS.
2091 * So, we need to add a special mount option to scan for
2092 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2093 */
2094 for (i = 0; i < 1; i++) {
2095 bytenr = btrfs_sb_offset(i);
2096 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2097 break;
2098 bh = __bread(bdev, bytenr / 4096, 4096);
2099 if (!bh)
2100 continue;
2101
2102 super = (struct btrfs_super_block *)bh->b_data;
2103 if (btrfs_super_bytenr(super) != bytenr ||
2104 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2105 sizeof(super->magic))) {
2106 brelse(bh);
2107 continue;
2108 }
2109
2110 if (!latest || btrfs_super_generation(super) > transid) {
2111 brelse(latest);
2112 latest = bh;
2113 transid = btrfs_super_generation(super);
2114 } else {
2115 brelse(bh);
2116 }
2117 }
2118 return latest;
2119 }
2120
2121 /*
2122 * this should be called twice, once with wait == 0 and
2123 * once with wait == 1. When wait == 0 is done, all the buffer heads
2124 * we write are pinned.
2125 *
2126 * They are released when wait == 1 is done.
2127 * max_mirrors must be the same for both runs, and it indicates how
2128 * many supers on this one device should be written.
2129 *
2130 * max_mirrors == 0 means to write them all.
2131 */
2132 static int write_dev_supers(struct btrfs_device *device,
2133 struct btrfs_super_block *sb,
2134 int do_barriers, int wait, int max_mirrors)
2135 {
2136 struct buffer_head *bh;
2137 int i;
2138 int ret;
2139 int errors = 0;
2140 u32 crc;
2141 u64 bytenr;
2142 int last_barrier = 0;
2143
2144 if (max_mirrors == 0)
2145 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2146
2147 /* make sure only the last submit_bh does a barrier */
2148 if (do_barriers) {
2149 for (i = 0; i < max_mirrors; i++) {
2150 bytenr = btrfs_sb_offset(i);
2151 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2152 device->total_bytes)
2153 break;
2154 last_barrier = i;
2155 }
2156 }
2157
2158 for (i = 0; i < max_mirrors; i++) {
2159 bytenr = btrfs_sb_offset(i);
2160 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2161 break;
2162
2163 if (wait) {
2164 bh = __find_get_block(device->bdev, bytenr / 4096,
2165 BTRFS_SUPER_INFO_SIZE);
2166 BUG_ON(!bh);
2167 wait_on_buffer(bh);
2168 if (!buffer_uptodate(bh))
2169 errors++;
2170
2171 /* drop our reference */
2172 brelse(bh);
2173
2174 /* drop the reference from the wait == 0 run */
2175 brelse(bh);
2176 continue;
2177 } else {
2178 btrfs_set_super_bytenr(sb, bytenr);
2179
2180 crc = ~(u32)0;
2181 crc = btrfs_csum_data(NULL, (char *)sb +
2182 BTRFS_CSUM_SIZE, crc,
2183 BTRFS_SUPER_INFO_SIZE -
2184 BTRFS_CSUM_SIZE);
2185 btrfs_csum_final(crc, sb->csum);
2186
2187 /*
2188 * one reference for us, and we leave it for the
2189 * caller
2190 */
2191 bh = __getblk(device->bdev, bytenr / 4096,
2192 BTRFS_SUPER_INFO_SIZE);
2193 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2194
2195 /* one reference for submit_bh */
2196 get_bh(bh);
2197
2198 set_buffer_uptodate(bh);
2199 lock_buffer(bh);
2200 bh->b_end_io = btrfs_end_buffer_write_sync;
2201 }
2202
2203 if (i == last_barrier && do_barriers)
2204 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2205 else
2206 ret = submit_bh(WRITE_SYNC, bh);
2207
2208 if (ret)
2209 errors++;
2210 }
2211 return errors < i ? 0 : -1;
2212 }
2213
2214 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2215 {
2216 struct list_head *head;
2217 struct btrfs_device *dev;
2218 struct btrfs_super_block *sb;
2219 struct btrfs_dev_item *dev_item;
2220 int ret;
2221 int do_barriers;
2222 int max_errors;
2223 int total_errors = 0;
2224 u64 flags;
2225
2226 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2227 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2228
2229 sb = &root->fs_info->super_for_commit;
2230 dev_item = &sb->dev_item;
2231
2232 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2233 head = &root->fs_info->fs_devices->devices;
2234 list_for_each_entry(dev, head, dev_list) {
2235 if (!dev->bdev) {
2236 total_errors++;
2237 continue;
2238 }
2239 if (!dev->in_fs_metadata || !dev->writeable)
2240 continue;
2241
2242 btrfs_set_stack_device_generation(dev_item, 0);
2243 btrfs_set_stack_device_type(dev_item, dev->type);
2244 btrfs_set_stack_device_id(dev_item, dev->devid);
2245 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2246 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2247 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2248 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2249 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2250 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2251 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2252
2253 flags = btrfs_super_flags(sb);
2254 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2255
2256 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2257 if (ret)
2258 total_errors++;
2259 }
2260 if (total_errors > max_errors) {
2261 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2262 total_errors);
2263 BUG();
2264 }
2265
2266 total_errors = 0;
2267 list_for_each_entry(dev, head, dev_list) {
2268 if (!dev->bdev)
2269 continue;
2270 if (!dev->in_fs_metadata || !dev->writeable)
2271 continue;
2272
2273 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2274 if (ret)
2275 total_errors++;
2276 }
2277 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2278 if (total_errors > max_errors) {
2279 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2280 total_errors);
2281 BUG();
2282 }
2283 return 0;
2284 }
2285
2286 int write_ctree_super(struct btrfs_trans_handle *trans,
2287 struct btrfs_root *root, int max_mirrors)
2288 {
2289 int ret;
2290
2291 ret = write_all_supers(root, max_mirrors);
2292 return ret;
2293 }
2294
2295 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2296 {
2297 spin_lock(&fs_info->fs_roots_radix_lock);
2298 radix_tree_delete(&fs_info->fs_roots_radix,
2299 (unsigned long)root->root_key.objectid);
2300 spin_unlock(&fs_info->fs_roots_radix_lock);
2301
2302 if (btrfs_root_refs(&root->root_item) == 0)
2303 synchronize_srcu(&fs_info->subvol_srcu);
2304
2305 free_fs_root(root);
2306 return 0;
2307 }
2308
2309 static void free_fs_root(struct btrfs_root *root)
2310 {
2311 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2312 if (root->anon_super.s_dev) {
2313 down_write(&root->anon_super.s_umount);
2314 kill_anon_super(&root->anon_super);
2315 }
2316 free_extent_buffer(root->node);
2317 free_extent_buffer(root->commit_root);
2318 kfree(root->name);
2319 kfree(root);
2320 }
2321
2322 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2323 {
2324 int ret;
2325 struct btrfs_root *gang[8];
2326 int i;
2327
2328 while (!list_empty(&fs_info->dead_roots)) {
2329 gang[0] = list_entry(fs_info->dead_roots.next,
2330 struct btrfs_root, root_list);
2331 list_del(&gang[0]->root_list);
2332
2333 if (gang[0]->in_radix) {
2334 btrfs_free_fs_root(fs_info, gang[0]);
2335 } else {
2336 free_extent_buffer(gang[0]->node);
2337 free_extent_buffer(gang[0]->commit_root);
2338 kfree(gang[0]);
2339 }
2340 }
2341
2342 while (1) {
2343 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2344 (void **)gang, 0,
2345 ARRAY_SIZE(gang));
2346 if (!ret)
2347 break;
2348 for (i = 0; i < ret; i++)
2349 btrfs_free_fs_root(fs_info, gang[i]);
2350 }
2351 return 0;
2352 }
2353
2354 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2355 {
2356 u64 root_objectid = 0;
2357 struct btrfs_root *gang[8];
2358 int i;
2359 int ret;
2360
2361 while (1) {
2362 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2363 (void **)gang, root_objectid,
2364 ARRAY_SIZE(gang));
2365 if (!ret)
2366 break;
2367
2368 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2369 for (i = 0; i < ret; i++) {
2370 root_objectid = gang[i]->root_key.objectid;
2371 btrfs_orphan_cleanup(gang[i]);
2372 }
2373 root_objectid++;
2374 }
2375 return 0;
2376 }
2377
2378 int btrfs_commit_super(struct btrfs_root *root)
2379 {
2380 struct btrfs_trans_handle *trans;
2381 int ret;
2382
2383 mutex_lock(&root->fs_info->cleaner_mutex);
2384 btrfs_run_delayed_iputs(root);
2385 btrfs_clean_old_snapshots(root);
2386 mutex_unlock(&root->fs_info->cleaner_mutex);
2387
2388 /* wait until ongoing cleanup work done */
2389 down_write(&root->fs_info->cleanup_work_sem);
2390 up_write(&root->fs_info->cleanup_work_sem);
2391
2392 trans = btrfs_join_transaction(root, 1);
2393 ret = btrfs_commit_transaction(trans, root);
2394 BUG_ON(ret);
2395 /* run commit again to drop the original snapshot */
2396 trans = btrfs_join_transaction(root, 1);
2397 btrfs_commit_transaction(trans, root);
2398 ret = btrfs_write_and_wait_transaction(NULL, root);
2399 BUG_ON(ret);
2400
2401 ret = write_ctree_super(NULL, root, 0);
2402 return ret;
2403 }
2404
2405 int close_ctree(struct btrfs_root *root)
2406 {
2407 struct btrfs_fs_info *fs_info = root->fs_info;
2408 int ret;
2409
2410 fs_info->closing = 1;
2411 smp_mb();
2412
2413 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2414 ret = btrfs_commit_super(root);
2415 if (ret)
2416 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2417 }
2418
2419 kthread_stop(root->fs_info->transaction_kthread);
2420 kthread_stop(root->fs_info->cleaner_kthread);
2421
2422 fs_info->closing = 2;
2423 smp_mb();
2424
2425 if (fs_info->delalloc_bytes) {
2426 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2427 (unsigned long long)fs_info->delalloc_bytes);
2428 }
2429 if (fs_info->total_ref_cache_size) {
2430 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2431 (unsigned long long)fs_info->total_ref_cache_size);
2432 }
2433
2434 free_extent_buffer(fs_info->extent_root->node);
2435 free_extent_buffer(fs_info->extent_root->commit_root);
2436 free_extent_buffer(fs_info->tree_root->node);
2437 free_extent_buffer(fs_info->tree_root->commit_root);
2438 free_extent_buffer(root->fs_info->chunk_root->node);
2439 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2440 free_extent_buffer(root->fs_info->dev_root->node);
2441 free_extent_buffer(root->fs_info->dev_root->commit_root);
2442 free_extent_buffer(root->fs_info->csum_root->node);
2443 free_extent_buffer(root->fs_info->csum_root->commit_root);
2444
2445 btrfs_free_block_groups(root->fs_info);
2446
2447 del_fs_roots(fs_info);
2448
2449 iput(fs_info->btree_inode);
2450
2451 btrfs_stop_workers(&fs_info->generic_worker);
2452 btrfs_stop_workers(&fs_info->fixup_workers);
2453 btrfs_stop_workers(&fs_info->delalloc_workers);
2454 btrfs_stop_workers(&fs_info->workers);
2455 btrfs_stop_workers(&fs_info->endio_workers);
2456 btrfs_stop_workers(&fs_info->endio_meta_workers);
2457 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2458 btrfs_stop_workers(&fs_info->endio_write_workers);
2459 btrfs_stop_workers(&fs_info->submit_workers);
2460
2461 btrfs_close_devices(fs_info->fs_devices);
2462 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2463
2464 bdi_destroy(&fs_info->bdi);
2465 cleanup_srcu_struct(&fs_info->subvol_srcu);
2466
2467 kfree(fs_info->extent_root);
2468 kfree(fs_info->tree_root);
2469 kfree(fs_info->chunk_root);
2470 kfree(fs_info->dev_root);
2471 kfree(fs_info->csum_root);
2472 return 0;
2473 }
2474
2475 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2476 {
2477 int ret;
2478 struct inode *btree_inode = buf->first_page->mapping->host;
2479
2480 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2481 NULL);
2482 if (!ret)
2483 return ret;
2484
2485 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2486 parent_transid);
2487 return !ret;
2488 }
2489
2490 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2491 {
2492 struct inode *btree_inode = buf->first_page->mapping->host;
2493 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2494 buf);
2495 }
2496
2497 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2498 {
2499 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2500 u64 transid = btrfs_header_generation(buf);
2501 struct inode *btree_inode = root->fs_info->btree_inode;
2502 int was_dirty;
2503
2504 btrfs_assert_tree_locked(buf);
2505 if (transid != root->fs_info->generation) {
2506 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2507 "found %llu running %llu\n",
2508 (unsigned long long)buf->start,
2509 (unsigned long long)transid,
2510 (unsigned long long)root->fs_info->generation);
2511 WARN_ON(1);
2512 }
2513 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2514 buf);
2515 if (!was_dirty) {
2516 spin_lock(&root->fs_info->delalloc_lock);
2517 root->fs_info->dirty_metadata_bytes += buf->len;
2518 spin_unlock(&root->fs_info->delalloc_lock);
2519 }
2520 }
2521
2522 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2523 {
2524 /*
2525 * looks as though older kernels can get into trouble with
2526 * this code, they end up stuck in balance_dirty_pages forever
2527 */
2528 u64 num_dirty;
2529 unsigned long thresh = 32 * 1024 * 1024;
2530
2531 if (current->flags & PF_MEMALLOC)
2532 return;
2533
2534 num_dirty = root->fs_info->dirty_metadata_bytes;
2535
2536 if (num_dirty > thresh) {
2537 balance_dirty_pages_ratelimited_nr(
2538 root->fs_info->btree_inode->i_mapping, 1);
2539 }
2540 return;
2541 }
2542
2543 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2544 {
2545 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2546 int ret;
2547 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2548 if (ret == 0)
2549 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2550 return ret;
2551 }
2552
2553 int btree_lock_page_hook(struct page *page)
2554 {
2555 struct inode *inode = page->mapping->host;
2556 struct btrfs_root *root = BTRFS_I(inode)->root;
2557 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2558 struct extent_buffer *eb;
2559 unsigned long len;
2560 u64 bytenr = page_offset(page);
2561
2562 if (page->private == EXTENT_PAGE_PRIVATE)
2563 goto out;
2564
2565 len = page->private >> 2;
2566 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2567 if (!eb)
2568 goto out;
2569
2570 btrfs_tree_lock(eb);
2571 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2572
2573 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2574 spin_lock(&root->fs_info->delalloc_lock);
2575 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2576 root->fs_info->dirty_metadata_bytes -= eb->len;
2577 else
2578 WARN_ON(1);
2579 spin_unlock(&root->fs_info->delalloc_lock);
2580 }
2581
2582 btrfs_tree_unlock(eb);
2583 free_extent_buffer(eb);
2584 out:
2585 lock_page(page);
2586 return 0;
2587 }
2588
2589 static struct extent_io_ops btree_extent_io_ops = {
2590 .write_cache_pages_lock_hook = btree_lock_page_hook,
2591 .readpage_end_io_hook = btree_readpage_end_io_hook,
2592 .submit_bio_hook = btree_submit_bio_hook,
2593 /* note we're sharing with inode.c for the merge bio hook */
2594 .merge_bio_hook = btrfs_merge_bio_hook,
2595 };
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