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Merge branch 'for-linus/samsung-fixes' of git://git.fluff.org/bjdooks/linux
[GitHub/mt8127/android_kernel_alcatel_ttab.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 "compat.h"
31 #include "ctree.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "volumes.h"
36 #include "print-tree.h"
37 #include "async-thread.h"
38 #include "locking.h"
39 #include "tree-log.h"
40 #include "free-space-cache.h"
41
42 static struct extent_io_ops btree_extent_io_ops;
43 static void end_workqueue_fn(struct btrfs_work *work);
44 static void free_fs_root(struct btrfs_root *root);
45
46 static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
47
48 /*
49 * end_io_wq structs are used to do processing in task context when an IO is
50 * complete. This is used during reads to verify checksums, and it is used
51 * by writes to insert metadata for new file extents after IO is complete.
52 */
53 struct end_io_wq {
54 struct bio *bio;
55 bio_end_io_t *end_io;
56 void *private;
57 struct btrfs_fs_info *info;
58 int error;
59 int metadata;
60 struct list_head list;
61 struct btrfs_work work;
62 };
63
64 /*
65 * async submit bios are used to offload expensive checksumming
66 * onto the worker threads. They checksum file and metadata bios
67 * just before they are sent down the IO stack.
68 */
69 struct async_submit_bio {
70 struct inode *inode;
71 struct bio *bio;
72 struct list_head list;
73 extent_submit_bio_hook_t *submit_bio_start;
74 extent_submit_bio_hook_t *submit_bio_done;
75 int rw;
76 int mirror_num;
77 unsigned long bio_flags;
78 struct btrfs_work work;
79 };
80
81 /* These are used to set the lockdep class on the extent buffer locks.
82 * The class is set by the readpage_end_io_hook after the buffer has
83 * passed csum validation but before the pages are unlocked.
84 *
85 * The lockdep class is also set by btrfs_init_new_buffer on freshly
86 * allocated blocks.
87 *
88 * The class is based on the level in the tree block, which allows lockdep
89 * to know that lower nodes nest inside the locks of higher nodes.
90 *
91 * We also add a check to make sure the highest level of the tree is
92 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
93 * code needs update as well.
94 */
95 #ifdef CONFIG_DEBUG_LOCK_ALLOC
96 # if BTRFS_MAX_LEVEL != 8
97 # error
98 # endif
99 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
100 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
101 /* leaf */
102 "btrfs-extent-00",
103 "btrfs-extent-01",
104 "btrfs-extent-02",
105 "btrfs-extent-03",
106 "btrfs-extent-04",
107 "btrfs-extent-05",
108 "btrfs-extent-06",
109 "btrfs-extent-07",
110 /* highest possible level */
111 "btrfs-extent-08",
112 };
113 #endif
114
115 /*
116 * extents on the btree inode are pretty simple, there's one extent
117 * that covers the entire device
118 */
119 static struct extent_map *btree_get_extent(struct inode *inode,
120 struct page *page, size_t page_offset, u64 start, u64 len,
121 int create)
122 {
123 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
124 struct extent_map *em;
125 int ret;
126
127 read_lock(&em_tree->lock);
128 em = lookup_extent_mapping(em_tree, start, len);
129 if (em) {
130 em->bdev =
131 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
132 read_unlock(&em_tree->lock);
133 goto out;
134 }
135 read_unlock(&em_tree->lock);
136
137 em = alloc_extent_map(GFP_NOFS);
138 if (!em) {
139 em = ERR_PTR(-ENOMEM);
140 goto out;
141 }
142 em->start = 0;
143 em->len = (u64)-1;
144 em->block_len = (u64)-1;
145 em->block_start = 0;
146 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
147
148 write_lock(&em_tree->lock);
149 ret = add_extent_mapping(em_tree, em);
150 if (ret == -EEXIST) {
151 u64 failed_start = em->start;
152 u64 failed_len = em->len;
153
154 free_extent_map(em);
155 em = lookup_extent_mapping(em_tree, start, len);
156 if (em) {
157 ret = 0;
158 } else {
159 em = lookup_extent_mapping(em_tree, failed_start,
160 failed_len);
161 ret = -EIO;
162 }
163 } else if (ret) {
164 free_extent_map(em);
165 em = NULL;
166 }
167 write_unlock(&em_tree->lock);
168
169 if (ret)
170 em = ERR_PTR(ret);
171 out:
172 return em;
173 }
174
175 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
176 {
177 return crc32c(seed, data, len);
178 }
179
180 void btrfs_csum_final(u32 crc, char *result)
181 {
182 *(__le32 *)result = ~cpu_to_le32(crc);
183 }
184
185 /*
186 * compute the csum for a btree block, and either verify it or write it
187 * into the csum field of the block.
188 */
189 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
190 int verify)
191 {
192 u16 csum_size =
193 btrfs_super_csum_size(&root->fs_info->super_copy);
194 char *result = NULL;
195 unsigned long len;
196 unsigned long cur_len;
197 unsigned long offset = BTRFS_CSUM_SIZE;
198 char *map_token = NULL;
199 char *kaddr;
200 unsigned long map_start;
201 unsigned long map_len;
202 int err;
203 u32 crc = ~(u32)0;
204 unsigned long inline_result;
205
206 len = buf->len - offset;
207 while (len > 0) {
208 err = map_private_extent_buffer(buf, offset, 32,
209 &map_token, &kaddr,
210 &map_start, &map_len, KM_USER0);
211 if (err)
212 return 1;
213 cur_len = min(len, map_len - (offset - map_start));
214 crc = btrfs_csum_data(root, kaddr + offset - map_start,
215 crc, cur_len);
216 len -= cur_len;
217 offset += cur_len;
218 unmap_extent_buffer(buf, map_token, KM_USER0);
219 }
220 if (csum_size > sizeof(inline_result)) {
221 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
222 if (!result)
223 return 1;
224 } else {
225 result = (char *)&inline_result;
226 }
227
228 btrfs_csum_final(crc, result);
229
230 if (verify) {
231 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
232 u32 val;
233 u32 found = 0;
234 memcpy(&found, result, csum_size);
235
236 read_extent_buffer(buf, &val, 0, csum_size);
237 if (printk_ratelimit()) {
238 printk(KERN_INFO "btrfs: %s checksum verify "
239 "failed on %llu wanted %X found %X "
240 "level %d\n",
241 root->fs_info->sb->s_id,
242 (unsigned long long)buf->start, val, found,
243 btrfs_header_level(buf));
244 }
245 if (result != (char *)&inline_result)
246 kfree(result);
247 return 1;
248 }
249 } else {
250 write_extent_buffer(buf, result, 0, csum_size);
251 }
252 if (result != (char *)&inline_result)
253 kfree(result);
254 return 0;
255 }
256
257 /*
258 * we can't consider a given block up to date unless the transid of the
259 * block matches the transid in the parent node's pointer. This is how we
260 * detect blocks that either didn't get written at all or got written
261 * in the wrong place.
262 */
263 static int verify_parent_transid(struct extent_io_tree *io_tree,
264 struct extent_buffer *eb, u64 parent_transid)
265 {
266 struct extent_state *cached_state = NULL;
267 int ret;
268
269 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
270 return 0;
271
272 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
273 0, &cached_state, GFP_NOFS);
274 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
275 btrfs_header_generation(eb) == parent_transid) {
276 ret = 0;
277 goto out;
278 }
279 if (printk_ratelimit()) {
280 printk("parent transid verify failed on %llu wanted %llu "
281 "found %llu\n",
282 (unsigned long long)eb->start,
283 (unsigned long long)parent_transid,
284 (unsigned long long)btrfs_header_generation(eb));
285 }
286 ret = 1;
287 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
288 out:
289 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
290 &cached_state, GFP_NOFS);
291 return ret;
292 }
293
294 /*
295 * helper to read a given tree block, doing retries as required when
296 * the checksums don't match and we have alternate mirrors to try.
297 */
298 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
299 struct extent_buffer *eb,
300 u64 start, u64 parent_transid)
301 {
302 struct extent_io_tree *io_tree;
303 int ret;
304 int num_copies = 0;
305 int mirror_num = 0;
306
307 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
308 while (1) {
309 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
310 btree_get_extent, mirror_num);
311 if (!ret &&
312 !verify_parent_transid(io_tree, eb, parent_transid))
313 return ret;
314
315 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
316 eb->start, eb->len);
317 if (num_copies == 1)
318 return ret;
319
320 mirror_num++;
321 if (mirror_num > num_copies)
322 return ret;
323 }
324 return -EIO;
325 }
326
327 /*
328 * checksum a dirty tree block before IO. This has extra checks to make sure
329 * we only fill in the checksum field in the first page of a multi-page block
330 */
331
332 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
333 {
334 struct extent_io_tree *tree;
335 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
336 u64 found_start;
337 int found_level;
338 unsigned long len;
339 struct extent_buffer *eb;
340 int ret;
341
342 tree = &BTRFS_I(page->mapping->host)->io_tree;
343
344 if (page->private == EXTENT_PAGE_PRIVATE)
345 goto out;
346 if (!page->private)
347 goto out;
348 len = page->private >> 2;
349 WARN_ON(len == 0);
350
351 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
352 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
353 btrfs_header_generation(eb));
354 BUG_ON(ret);
355 found_start = btrfs_header_bytenr(eb);
356 if (found_start != start) {
357 WARN_ON(1);
358 goto err;
359 }
360 if (eb->first_page != page) {
361 WARN_ON(1);
362 goto err;
363 }
364 if (!PageUptodate(page)) {
365 WARN_ON(1);
366 goto err;
367 }
368 found_level = btrfs_header_level(eb);
369
370 csum_tree_block(root, eb, 0);
371 err:
372 free_extent_buffer(eb);
373 out:
374 return 0;
375 }
376
377 static int check_tree_block_fsid(struct btrfs_root *root,
378 struct extent_buffer *eb)
379 {
380 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
381 u8 fsid[BTRFS_UUID_SIZE];
382 int ret = 1;
383
384 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
385 BTRFS_FSID_SIZE);
386 while (fs_devices) {
387 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
388 ret = 0;
389 break;
390 }
391 fs_devices = fs_devices->seed;
392 }
393 return ret;
394 }
395
396 #ifdef CONFIG_DEBUG_LOCK_ALLOC
397 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
398 {
399 lockdep_set_class_and_name(&eb->lock,
400 &btrfs_eb_class[level],
401 btrfs_eb_name[level]);
402 }
403 #endif
404
405 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
406 struct extent_state *state)
407 {
408 struct extent_io_tree *tree;
409 u64 found_start;
410 int found_level;
411 unsigned long len;
412 struct extent_buffer *eb;
413 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
414 int ret = 0;
415
416 tree = &BTRFS_I(page->mapping->host)->io_tree;
417 if (page->private == EXTENT_PAGE_PRIVATE)
418 goto out;
419 if (!page->private)
420 goto out;
421
422 len = page->private >> 2;
423 WARN_ON(len == 0);
424
425 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
426
427 found_start = btrfs_header_bytenr(eb);
428 if (found_start != start) {
429 if (printk_ratelimit()) {
430 printk(KERN_INFO "btrfs bad tree block start "
431 "%llu %llu\n",
432 (unsigned long long)found_start,
433 (unsigned long long)eb->start);
434 }
435 ret = -EIO;
436 goto err;
437 }
438 if (eb->first_page != page) {
439 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
440 eb->first_page->index, page->index);
441 WARN_ON(1);
442 ret = -EIO;
443 goto err;
444 }
445 if (check_tree_block_fsid(root, eb)) {
446 if (printk_ratelimit()) {
447 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
448 (unsigned long long)eb->start);
449 }
450 ret = -EIO;
451 goto err;
452 }
453 found_level = btrfs_header_level(eb);
454
455 btrfs_set_buffer_lockdep_class(eb, found_level);
456
457 ret = csum_tree_block(root, eb, 1);
458 if (ret)
459 ret = -EIO;
460
461 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
462 end = eb->start + end - 1;
463 err:
464 free_extent_buffer(eb);
465 out:
466 return ret;
467 }
468
469 static void end_workqueue_bio(struct bio *bio, int err)
470 {
471 struct end_io_wq *end_io_wq = bio->bi_private;
472 struct btrfs_fs_info *fs_info;
473
474 fs_info = end_io_wq->info;
475 end_io_wq->error = err;
476 end_io_wq->work.func = end_workqueue_fn;
477 end_io_wq->work.flags = 0;
478
479 if (bio->bi_rw & (1 << BIO_RW)) {
480 if (end_io_wq->metadata)
481 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
482 &end_io_wq->work);
483 else
484 btrfs_queue_worker(&fs_info->endio_write_workers,
485 &end_io_wq->work);
486 } else {
487 if (end_io_wq->metadata)
488 btrfs_queue_worker(&fs_info->endio_meta_workers,
489 &end_io_wq->work);
490 else
491 btrfs_queue_worker(&fs_info->endio_workers,
492 &end_io_wq->work);
493 }
494 }
495
496 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
497 int metadata)
498 {
499 struct end_io_wq *end_io_wq;
500 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
501 if (!end_io_wq)
502 return -ENOMEM;
503
504 end_io_wq->private = bio->bi_private;
505 end_io_wq->end_io = bio->bi_end_io;
506 end_io_wq->info = info;
507 end_io_wq->error = 0;
508 end_io_wq->bio = bio;
509 end_io_wq->metadata = metadata;
510
511 bio->bi_private = end_io_wq;
512 bio->bi_end_io = end_workqueue_bio;
513 return 0;
514 }
515
516 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
517 {
518 unsigned long limit = min_t(unsigned long,
519 info->workers.max_workers,
520 info->fs_devices->open_devices);
521 return 256 * limit;
522 }
523
524 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
525 {
526 return atomic_read(&info->nr_async_bios) >
527 btrfs_async_submit_limit(info);
528 }
529
530 static void run_one_async_start(struct btrfs_work *work)
531 {
532 struct btrfs_fs_info *fs_info;
533 struct async_submit_bio *async;
534
535 async = container_of(work, struct async_submit_bio, work);
536 fs_info = BTRFS_I(async->inode)->root->fs_info;
537 async->submit_bio_start(async->inode, async->rw, async->bio,
538 async->mirror_num, async->bio_flags);
539 }
540
541 static void run_one_async_done(struct btrfs_work *work)
542 {
543 struct btrfs_fs_info *fs_info;
544 struct async_submit_bio *async;
545 int limit;
546
547 async = container_of(work, struct async_submit_bio, work);
548 fs_info = BTRFS_I(async->inode)->root->fs_info;
549
550 limit = btrfs_async_submit_limit(fs_info);
551 limit = limit * 2 / 3;
552
553 atomic_dec(&fs_info->nr_async_submits);
554
555 if (atomic_read(&fs_info->nr_async_submits) < limit &&
556 waitqueue_active(&fs_info->async_submit_wait))
557 wake_up(&fs_info->async_submit_wait);
558
559 async->submit_bio_done(async->inode, async->rw, async->bio,
560 async->mirror_num, async->bio_flags);
561 }
562
563 static void run_one_async_free(struct btrfs_work *work)
564 {
565 struct async_submit_bio *async;
566
567 async = container_of(work, struct async_submit_bio, work);
568 kfree(async);
569 }
570
571 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
572 int rw, struct bio *bio, int mirror_num,
573 unsigned long bio_flags,
574 extent_submit_bio_hook_t *submit_bio_start,
575 extent_submit_bio_hook_t *submit_bio_done)
576 {
577 struct async_submit_bio *async;
578
579 async = kmalloc(sizeof(*async), GFP_NOFS);
580 if (!async)
581 return -ENOMEM;
582
583 async->inode = inode;
584 async->rw = rw;
585 async->bio = bio;
586 async->mirror_num = mirror_num;
587 async->submit_bio_start = submit_bio_start;
588 async->submit_bio_done = submit_bio_done;
589
590 async->work.func = run_one_async_start;
591 async->work.ordered_func = run_one_async_done;
592 async->work.ordered_free = run_one_async_free;
593
594 async->work.flags = 0;
595 async->bio_flags = bio_flags;
596
597 atomic_inc(&fs_info->nr_async_submits);
598
599 if (rw & (1 << BIO_RW_SYNCIO))
600 btrfs_set_work_high_prio(&async->work);
601
602 btrfs_queue_worker(&fs_info->workers, &async->work);
603
604 while (atomic_read(&fs_info->async_submit_draining) &&
605 atomic_read(&fs_info->nr_async_submits)) {
606 wait_event(fs_info->async_submit_wait,
607 (atomic_read(&fs_info->nr_async_submits) == 0));
608 }
609
610 return 0;
611 }
612
613 static int btree_csum_one_bio(struct bio *bio)
614 {
615 struct bio_vec *bvec = bio->bi_io_vec;
616 int bio_index = 0;
617 struct btrfs_root *root;
618
619 WARN_ON(bio->bi_vcnt <= 0);
620 while (bio_index < bio->bi_vcnt) {
621 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
622 csum_dirty_buffer(root, bvec->bv_page);
623 bio_index++;
624 bvec++;
625 }
626 return 0;
627 }
628
629 static int __btree_submit_bio_start(struct inode *inode, int rw,
630 struct bio *bio, int mirror_num,
631 unsigned long bio_flags)
632 {
633 /*
634 * when we're called for a write, we're already in the async
635 * submission context. Just jump into btrfs_map_bio
636 */
637 btree_csum_one_bio(bio);
638 return 0;
639 }
640
641 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
642 int mirror_num, unsigned long bio_flags)
643 {
644 /*
645 * when we're called for a write, we're already in the async
646 * submission context. Just jump into btrfs_map_bio
647 */
648 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
649 }
650
651 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
652 int mirror_num, unsigned long bio_flags)
653 {
654 int ret;
655
656 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
657 bio, 1);
658 BUG_ON(ret);
659
660 if (!(rw & (1 << BIO_RW))) {
661 /*
662 * called for a read, do the setup so that checksum validation
663 * can happen in the async kernel threads
664 */
665 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
666 mirror_num, 0);
667 }
668
669 /*
670 * kthread helpers are used to submit writes so that checksumming
671 * can happen in parallel across all CPUs
672 */
673 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
674 inode, rw, bio, mirror_num, 0,
675 __btree_submit_bio_start,
676 __btree_submit_bio_done);
677 }
678
679 static int btree_writepage(struct page *page, struct writeback_control *wbc)
680 {
681 struct extent_io_tree *tree;
682 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
683 struct extent_buffer *eb;
684 int was_dirty;
685
686 tree = &BTRFS_I(page->mapping->host)->io_tree;
687 if (!(current->flags & PF_MEMALLOC)) {
688 return extent_write_full_page(tree, page,
689 btree_get_extent, wbc);
690 }
691
692 redirty_page_for_writepage(wbc, page);
693 eb = btrfs_find_tree_block(root, page_offset(page),
694 PAGE_CACHE_SIZE);
695 WARN_ON(!eb);
696
697 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
698 if (!was_dirty) {
699 spin_lock(&root->fs_info->delalloc_lock);
700 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
701 spin_unlock(&root->fs_info->delalloc_lock);
702 }
703 free_extent_buffer(eb);
704
705 unlock_page(page);
706 return 0;
707 }
708
709 static int btree_writepages(struct address_space *mapping,
710 struct writeback_control *wbc)
711 {
712 struct extent_io_tree *tree;
713 tree = &BTRFS_I(mapping->host)->io_tree;
714 if (wbc->sync_mode == WB_SYNC_NONE) {
715 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
716 u64 num_dirty;
717 unsigned long thresh = 32 * 1024 * 1024;
718
719 if (wbc->for_kupdate)
720 return 0;
721
722 /* this is a bit racy, but that's ok */
723 num_dirty = root->fs_info->dirty_metadata_bytes;
724 if (num_dirty < thresh)
725 return 0;
726 }
727 return extent_writepages(tree, mapping, btree_get_extent, wbc);
728 }
729
730 static int btree_readpage(struct file *file, struct page *page)
731 {
732 struct extent_io_tree *tree;
733 tree = &BTRFS_I(page->mapping->host)->io_tree;
734 return extent_read_full_page(tree, page, btree_get_extent);
735 }
736
737 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
738 {
739 struct extent_io_tree *tree;
740 struct extent_map_tree *map;
741 int ret;
742
743 if (PageWriteback(page) || PageDirty(page))
744 return 0;
745
746 tree = &BTRFS_I(page->mapping->host)->io_tree;
747 map = &BTRFS_I(page->mapping->host)->extent_tree;
748
749 ret = try_release_extent_state(map, tree, page, gfp_flags);
750 if (!ret)
751 return 0;
752
753 ret = try_release_extent_buffer(tree, page);
754 if (ret == 1) {
755 ClearPagePrivate(page);
756 set_page_private(page, 0);
757 page_cache_release(page);
758 }
759
760 return ret;
761 }
762
763 static void btree_invalidatepage(struct page *page, unsigned long offset)
764 {
765 struct extent_io_tree *tree;
766 tree = &BTRFS_I(page->mapping->host)->io_tree;
767 extent_invalidatepage(tree, page, offset);
768 btree_releasepage(page, GFP_NOFS);
769 if (PagePrivate(page)) {
770 printk(KERN_WARNING "btrfs warning page private not zero "
771 "on page %llu\n", (unsigned long long)page_offset(page));
772 ClearPagePrivate(page);
773 set_page_private(page, 0);
774 page_cache_release(page);
775 }
776 }
777
778 static const struct address_space_operations btree_aops = {
779 .readpage = btree_readpage,
780 .writepage = btree_writepage,
781 .writepages = btree_writepages,
782 .releasepage = btree_releasepage,
783 .invalidatepage = btree_invalidatepage,
784 .sync_page = block_sync_page,
785 };
786
787 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
788 u64 parent_transid)
789 {
790 struct extent_buffer *buf = NULL;
791 struct inode *btree_inode = root->fs_info->btree_inode;
792 int ret = 0;
793
794 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
795 if (!buf)
796 return 0;
797 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
798 buf, 0, 0, btree_get_extent, 0);
799 free_extent_buffer(buf);
800 return ret;
801 }
802
803 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
804 u64 bytenr, u32 blocksize)
805 {
806 struct inode *btree_inode = root->fs_info->btree_inode;
807 struct extent_buffer *eb;
808 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
809 bytenr, blocksize, GFP_NOFS);
810 return eb;
811 }
812
813 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
814 u64 bytenr, u32 blocksize)
815 {
816 struct inode *btree_inode = root->fs_info->btree_inode;
817 struct extent_buffer *eb;
818
819 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
820 bytenr, blocksize, NULL, GFP_NOFS);
821 return eb;
822 }
823
824
825 int btrfs_write_tree_block(struct extent_buffer *buf)
826 {
827 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
828 buf->start + buf->len - 1);
829 }
830
831 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
832 {
833 return filemap_fdatawait_range(buf->first_page->mapping,
834 buf->start, buf->start + buf->len - 1);
835 }
836
837 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
838 u32 blocksize, u64 parent_transid)
839 {
840 struct extent_buffer *buf = NULL;
841 struct inode *btree_inode = root->fs_info->btree_inode;
842 struct extent_io_tree *io_tree;
843 int ret;
844
845 io_tree = &BTRFS_I(btree_inode)->io_tree;
846
847 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
848 if (!buf)
849 return NULL;
850
851 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
852
853 if (ret == 0)
854 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
855 return buf;
856
857 }
858
859 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
860 struct extent_buffer *buf)
861 {
862 struct inode *btree_inode = root->fs_info->btree_inode;
863 if (btrfs_header_generation(buf) ==
864 root->fs_info->running_transaction->transid) {
865 btrfs_assert_tree_locked(buf);
866
867 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
868 spin_lock(&root->fs_info->delalloc_lock);
869 if (root->fs_info->dirty_metadata_bytes >= buf->len)
870 root->fs_info->dirty_metadata_bytes -= buf->len;
871 else
872 WARN_ON(1);
873 spin_unlock(&root->fs_info->delalloc_lock);
874 }
875
876 /* ugh, clear_extent_buffer_dirty needs to lock the page */
877 btrfs_set_lock_blocking(buf);
878 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
879 buf);
880 }
881 return 0;
882 }
883
884 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
885 u32 stripesize, struct btrfs_root *root,
886 struct btrfs_fs_info *fs_info,
887 u64 objectid)
888 {
889 root->node = NULL;
890 root->commit_root = NULL;
891 root->sectorsize = sectorsize;
892 root->nodesize = nodesize;
893 root->leafsize = leafsize;
894 root->stripesize = stripesize;
895 root->ref_cows = 0;
896 root->track_dirty = 0;
897 root->in_radix = 0;
898 root->clean_orphans = 0;
899
900 root->fs_info = fs_info;
901 root->objectid = objectid;
902 root->last_trans = 0;
903 root->highest_objectid = 0;
904 root->name = NULL;
905 root->in_sysfs = 0;
906 root->inode_tree = RB_ROOT;
907
908 INIT_LIST_HEAD(&root->dirty_list);
909 INIT_LIST_HEAD(&root->orphan_list);
910 INIT_LIST_HEAD(&root->root_list);
911 spin_lock_init(&root->node_lock);
912 spin_lock_init(&root->list_lock);
913 spin_lock_init(&root->inode_lock);
914 mutex_init(&root->objectid_mutex);
915 mutex_init(&root->log_mutex);
916 init_waitqueue_head(&root->log_writer_wait);
917 init_waitqueue_head(&root->log_commit_wait[0]);
918 init_waitqueue_head(&root->log_commit_wait[1]);
919 atomic_set(&root->log_commit[0], 0);
920 atomic_set(&root->log_commit[1], 0);
921 atomic_set(&root->log_writers, 0);
922 root->log_batch = 0;
923 root->log_transid = 0;
924 root->last_log_commit = 0;
925 extent_io_tree_init(&root->dirty_log_pages,
926 fs_info->btree_inode->i_mapping, GFP_NOFS);
927
928 memset(&root->root_key, 0, sizeof(root->root_key));
929 memset(&root->root_item, 0, sizeof(root->root_item));
930 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
931 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
932 root->defrag_trans_start = fs_info->generation;
933 init_completion(&root->kobj_unregister);
934 root->defrag_running = 0;
935 root->root_key.objectid = objectid;
936 root->anon_super.s_root = NULL;
937 root->anon_super.s_dev = 0;
938 INIT_LIST_HEAD(&root->anon_super.s_list);
939 INIT_LIST_HEAD(&root->anon_super.s_instances);
940 init_rwsem(&root->anon_super.s_umount);
941
942 return 0;
943 }
944
945 static int find_and_setup_root(struct btrfs_root *tree_root,
946 struct btrfs_fs_info *fs_info,
947 u64 objectid,
948 struct btrfs_root *root)
949 {
950 int ret;
951 u32 blocksize;
952 u64 generation;
953
954 __setup_root(tree_root->nodesize, tree_root->leafsize,
955 tree_root->sectorsize, tree_root->stripesize,
956 root, fs_info, objectid);
957 ret = btrfs_find_last_root(tree_root, objectid,
958 &root->root_item, &root->root_key);
959 if (ret > 0)
960 return -ENOENT;
961 BUG_ON(ret);
962
963 generation = btrfs_root_generation(&root->root_item);
964 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
965 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
966 blocksize, generation);
967 BUG_ON(!root->node);
968 root->commit_root = btrfs_root_node(root);
969 return 0;
970 }
971
972 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
973 struct btrfs_fs_info *fs_info)
974 {
975 struct extent_buffer *eb;
976 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
977 u64 start = 0;
978 u64 end = 0;
979 int ret;
980
981 if (!log_root_tree)
982 return 0;
983
984 while (1) {
985 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
986 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
987 if (ret)
988 break;
989
990 clear_extent_bits(&log_root_tree->dirty_log_pages, start, end,
991 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
992 }
993 eb = fs_info->log_root_tree->node;
994
995 WARN_ON(btrfs_header_level(eb) != 0);
996 WARN_ON(btrfs_header_nritems(eb) != 0);
997
998 ret = btrfs_free_reserved_extent(fs_info->tree_root,
999 eb->start, eb->len);
1000 BUG_ON(ret);
1001
1002 free_extent_buffer(eb);
1003 kfree(fs_info->log_root_tree);
1004 fs_info->log_root_tree = NULL;
1005 return 0;
1006 }
1007
1008 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1009 struct btrfs_fs_info *fs_info)
1010 {
1011 struct btrfs_root *root;
1012 struct btrfs_root *tree_root = fs_info->tree_root;
1013 struct extent_buffer *leaf;
1014
1015 root = kzalloc(sizeof(*root), GFP_NOFS);
1016 if (!root)
1017 return ERR_PTR(-ENOMEM);
1018
1019 __setup_root(tree_root->nodesize, tree_root->leafsize,
1020 tree_root->sectorsize, tree_root->stripesize,
1021 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1022
1023 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1024 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1025 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1026 /*
1027 * log trees do not get reference counted because they go away
1028 * before a real commit is actually done. They do store pointers
1029 * to file data extents, and those reference counts still get
1030 * updated (along with back refs to the log tree).
1031 */
1032 root->ref_cows = 0;
1033
1034 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1035 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1036 if (IS_ERR(leaf)) {
1037 kfree(root);
1038 return ERR_CAST(leaf);
1039 }
1040
1041 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1042 btrfs_set_header_bytenr(leaf, leaf->start);
1043 btrfs_set_header_generation(leaf, trans->transid);
1044 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1045 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1046 root->node = leaf;
1047
1048 write_extent_buffer(root->node, root->fs_info->fsid,
1049 (unsigned long)btrfs_header_fsid(root->node),
1050 BTRFS_FSID_SIZE);
1051 btrfs_mark_buffer_dirty(root->node);
1052 btrfs_tree_unlock(root->node);
1053 return root;
1054 }
1055
1056 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1057 struct btrfs_fs_info *fs_info)
1058 {
1059 struct btrfs_root *log_root;
1060
1061 log_root = alloc_log_tree(trans, fs_info);
1062 if (IS_ERR(log_root))
1063 return PTR_ERR(log_root);
1064 WARN_ON(fs_info->log_root_tree);
1065 fs_info->log_root_tree = log_root;
1066 return 0;
1067 }
1068
1069 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1070 struct btrfs_root *root)
1071 {
1072 struct btrfs_root *log_root;
1073 struct btrfs_inode_item *inode_item;
1074
1075 log_root = alloc_log_tree(trans, root->fs_info);
1076 if (IS_ERR(log_root))
1077 return PTR_ERR(log_root);
1078
1079 log_root->last_trans = trans->transid;
1080 log_root->root_key.offset = root->root_key.objectid;
1081
1082 inode_item = &log_root->root_item.inode;
1083 inode_item->generation = cpu_to_le64(1);
1084 inode_item->size = cpu_to_le64(3);
1085 inode_item->nlink = cpu_to_le32(1);
1086 inode_item->nbytes = cpu_to_le64(root->leafsize);
1087 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1088
1089 btrfs_set_root_node(&log_root->root_item, log_root->node);
1090
1091 WARN_ON(root->log_root);
1092 root->log_root = log_root;
1093 root->log_transid = 0;
1094 root->last_log_commit = 0;
1095 return 0;
1096 }
1097
1098 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1099 struct btrfs_key *location)
1100 {
1101 struct btrfs_root *root;
1102 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1103 struct btrfs_path *path;
1104 struct extent_buffer *l;
1105 u64 generation;
1106 u32 blocksize;
1107 int ret = 0;
1108
1109 root = kzalloc(sizeof(*root), GFP_NOFS);
1110 if (!root)
1111 return ERR_PTR(-ENOMEM);
1112 if (location->offset == (u64)-1) {
1113 ret = find_and_setup_root(tree_root, fs_info,
1114 location->objectid, root);
1115 if (ret) {
1116 kfree(root);
1117 return ERR_PTR(ret);
1118 }
1119 goto out;
1120 }
1121
1122 __setup_root(tree_root->nodesize, tree_root->leafsize,
1123 tree_root->sectorsize, tree_root->stripesize,
1124 root, fs_info, location->objectid);
1125
1126 path = btrfs_alloc_path();
1127 BUG_ON(!path);
1128 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1129 if (ret == 0) {
1130 l = path->nodes[0];
1131 read_extent_buffer(l, &root->root_item,
1132 btrfs_item_ptr_offset(l, path->slots[0]),
1133 sizeof(root->root_item));
1134 memcpy(&root->root_key, location, sizeof(*location));
1135 }
1136 btrfs_free_path(path);
1137 if (ret) {
1138 if (ret > 0)
1139 ret = -ENOENT;
1140 return ERR_PTR(ret);
1141 }
1142
1143 generation = btrfs_root_generation(&root->root_item);
1144 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1145 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1146 blocksize, generation);
1147 root->commit_root = btrfs_root_node(root);
1148 BUG_ON(!root->node);
1149 out:
1150 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1151 root->ref_cows = 1;
1152
1153 return root;
1154 }
1155
1156 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1157 u64 root_objectid)
1158 {
1159 struct btrfs_root *root;
1160
1161 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1162 return fs_info->tree_root;
1163 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1164 return fs_info->extent_root;
1165
1166 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1167 (unsigned long)root_objectid);
1168 return root;
1169 }
1170
1171 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1172 struct btrfs_key *location)
1173 {
1174 struct btrfs_root *root;
1175 int ret;
1176
1177 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1178 return fs_info->tree_root;
1179 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1180 return fs_info->extent_root;
1181 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1182 return fs_info->chunk_root;
1183 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1184 return fs_info->dev_root;
1185 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1186 return fs_info->csum_root;
1187 again:
1188 spin_lock(&fs_info->fs_roots_radix_lock);
1189 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1190 (unsigned long)location->objectid);
1191 spin_unlock(&fs_info->fs_roots_radix_lock);
1192 if (root)
1193 return root;
1194
1195 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1196 if (ret == 0)
1197 ret = -ENOENT;
1198 if (ret < 0)
1199 return ERR_PTR(ret);
1200
1201 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1202 if (IS_ERR(root))
1203 return root;
1204
1205 WARN_ON(btrfs_root_refs(&root->root_item) == 0);
1206 set_anon_super(&root->anon_super, NULL);
1207
1208 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1209 if (ret)
1210 goto fail;
1211
1212 spin_lock(&fs_info->fs_roots_radix_lock);
1213 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1214 (unsigned long)root->root_key.objectid,
1215 root);
1216 if (ret == 0) {
1217 root->in_radix = 1;
1218 root->clean_orphans = 1;
1219 }
1220 spin_unlock(&fs_info->fs_roots_radix_lock);
1221 radix_tree_preload_end();
1222 if (ret) {
1223 if (ret == -EEXIST) {
1224 free_fs_root(root);
1225 goto again;
1226 }
1227 goto fail;
1228 }
1229
1230 ret = btrfs_find_dead_roots(fs_info->tree_root,
1231 root->root_key.objectid);
1232 WARN_ON(ret);
1233 return root;
1234 fail:
1235 free_fs_root(root);
1236 return ERR_PTR(ret);
1237 }
1238
1239 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1240 struct btrfs_key *location,
1241 const char *name, int namelen)
1242 {
1243 return btrfs_read_fs_root_no_name(fs_info, location);
1244 #if 0
1245 struct btrfs_root *root;
1246 int ret;
1247
1248 root = btrfs_read_fs_root_no_name(fs_info, location);
1249 if (!root)
1250 return NULL;
1251
1252 if (root->in_sysfs)
1253 return root;
1254
1255 ret = btrfs_set_root_name(root, name, namelen);
1256 if (ret) {
1257 free_extent_buffer(root->node);
1258 kfree(root);
1259 return ERR_PTR(ret);
1260 }
1261
1262 ret = btrfs_sysfs_add_root(root);
1263 if (ret) {
1264 free_extent_buffer(root->node);
1265 kfree(root->name);
1266 kfree(root);
1267 return ERR_PTR(ret);
1268 }
1269 root->in_sysfs = 1;
1270 return root;
1271 #endif
1272 }
1273
1274 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1275 {
1276 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1277 int ret = 0;
1278 struct btrfs_device *device;
1279 struct backing_dev_info *bdi;
1280
1281 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1282 if (!device->bdev)
1283 continue;
1284 bdi = blk_get_backing_dev_info(device->bdev);
1285 if (bdi && bdi_congested(bdi, bdi_bits)) {
1286 ret = 1;
1287 break;
1288 }
1289 }
1290 return ret;
1291 }
1292
1293 /*
1294 * this unplugs every device on the box, and it is only used when page
1295 * is null
1296 */
1297 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1298 {
1299 struct btrfs_device *device;
1300 struct btrfs_fs_info *info;
1301
1302 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1303 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1304 if (!device->bdev)
1305 continue;
1306
1307 bdi = blk_get_backing_dev_info(device->bdev);
1308 if (bdi->unplug_io_fn)
1309 bdi->unplug_io_fn(bdi, page);
1310 }
1311 }
1312
1313 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1314 {
1315 struct inode *inode;
1316 struct extent_map_tree *em_tree;
1317 struct extent_map *em;
1318 struct address_space *mapping;
1319 u64 offset;
1320
1321 /* the generic O_DIRECT read code does this */
1322 if (1 || !page) {
1323 __unplug_io_fn(bdi, page);
1324 return;
1325 }
1326
1327 /*
1328 * page->mapping may change at any time. Get a consistent copy
1329 * and use that for everything below
1330 */
1331 smp_mb();
1332 mapping = page->mapping;
1333 if (!mapping)
1334 return;
1335
1336 inode = mapping->host;
1337
1338 /*
1339 * don't do the expensive searching for a small number of
1340 * devices
1341 */
1342 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1343 __unplug_io_fn(bdi, page);
1344 return;
1345 }
1346
1347 offset = page_offset(page);
1348
1349 em_tree = &BTRFS_I(inode)->extent_tree;
1350 read_lock(&em_tree->lock);
1351 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1352 read_unlock(&em_tree->lock);
1353 if (!em) {
1354 __unplug_io_fn(bdi, page);
1355 return;
1356 }
1357
1358 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1359 free_extent_map(em);
1360 __unplug_io_fn(bdi, page);
1361 return;
1362 }
1363 offset = offset - em->start;
1364 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1365 em->block_start + offset, page);
1366 free_extent_map(em);
1367 }
1368
1369 /*
1370 * If this fails, caller must call bdi_destroy() to get rid of the
1371 * bdi again.
1372 */
1373 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1374 {
1375 int err;
1376
1377 bdi->name = "btrfs";
1378 bdi->capabilities = BDI_CAP_MAP_COPY;
1379 err = bdi_init(bdi);
1380 if (err)
1381 return err;
1382
1383 err = bdi_register(bdi, NULL, "btrfs-%d",
1384 atomic_inc_return(&btrfs_bdi_num));
1385 if (err) {
1386 bdi_destroy(bdi);
1387 return err;
1388 }
1389
1390 bdi->ra_pages = default_backing_dev_info.ra_pages;
1391 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1392 bdi->unplug_io_data = info;
1393 bdi->congested_fn = btrfs_congested_fn;
1394 bdi->congested_data = info;
1395 return 0;
1396 }
1397
1398 static int bio_ready_for_csum(struct bio *bio)
1399 {
1400 u64 length = 0;
1401 u64 buf_len = 0;
1402 u64 start = 0;
1403 struct page *page;
1404 struct extent_io_tree *io_tree = NULL;
1405 struct btrfs_fs_info *info = NULL;
1406 struct bio_vec *bvec;
1407 int i;
1408 int ret;
1409
1410 bio_for_each_segment(bvec, bio, i) {
1411 page = bvec->bv_page;
1412 if (page->private == EXTENT_PAGE_PRIVATE) {
1413 length += bvec->bv_len;
1414 continue;
1415 }
1416 if (!page->private) {
1417 length += bvec->bv_len;
1418 continue;
1419 }
1420 length = bvec->bv_len;
1421 buf_len = page->private >> 2;
1422 start = page_offset(page) + bvec->bv_offset;
1423 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1424 info = BTRFS_I(page->mapping->host)->root->fs_info;
1425 }
1426 /* are we fully contained in this bio? */
1427 if (buf_len <= length)
1428 return 1;
1429
1430 ret = extent_range_uptodate(io_tree, start + length,
1431 start + buf_len - 1);
1432 return ret;
1433 }
1434
1435 /*
1436 * called by the kthread helper functions to finally call the bio end_io
1437 * functions. This is where read checksum verification actually happens
1438 */
1439 static void end_workqueue_fn(struct btrfs_work *work)
1440 {
1441 struct bio *bio;
1442 struct end_io_wq *end_io_wq;
1443 struct btrfs_fs_info *fs_info;
1444 int error;
1445
1446 end_io_wq = container_of(work, struct end_io_wq, work);
1447 bio = end_io_wq->bio;
1448 fs_info = end_io_wq->info;
1449
1450 /* metadata bio reads are special because the whole tree block must
1451 * be checksummed at once. This makes sure the entire block is in
1452 * ram and up to date before trying to verify things. For
1453 * blocksize <= pagesize, it is basically a noop
1454 */
1455 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1456 !bio_ready_for_csum(bio)) {
1457 btrfs_queue_worker(&fs_info->endio_meta_workers,
1458 &end_io_wq->work);
1459 return;
1460 }
1461 error = end_io_wq->error;
1462 bio->bi_private = end_io_wq->private;
1463 bio->bi_end_io = end_io_wq->end_io;
1464 kfree(end_io_wq);
1465 bio_endio(bio, error);
1466 }
1467
1468 static int cleaner_kthread(void *arg)
1469 {
1470 struct btrfs_root *root = arg;
1471
1472 do {
1473 smp_mb();
1474 if (root->fs_info->closing)
1475 break;
1476
1477 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1478
1479 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1480 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1481 btrfs_run_delayed_iputs(root);
1482 btrfs_clean_old_snapshots(root);
1483 mutex_unlock(&root->fs_info->cleaner_mutex);
1484 }
1485
1486 if (freezing(current)) {
1487 refrigerator();
1488 } else {
1489 smp_mb();
1490 if (root->fs_info->closing)
1491 break;
1492 set_current_state(TASK_INTERRUPTIBLE);
1493 schedule();
1494 __set_current_state(TASK_RUNNING);
1495 }
1496 } while (!kthread_should_stop());
1497 return 0;
1498 }
1499
1500 static int transaction_kthread(void *arg)
1501 {
1502 struct btrfs_root *root = arg;
1503 struct btrfs_trans_handle *trans;
1504 struct btrfs_transaction *cur;
1505 unsigned long now;
1506 unsigned long delay;
1507 int ret;
1508
1509 do {
1510 smp_mb();
1511 if (root->fs_info->closing)
1512 break;
1513
1514 delay = HZ * 30;
1515 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1516 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1517
1518 mutex_lock(&root->fs_info->trans_mutex);
1519 cur = root->fs_info->running_transaction;
1520 if (!cur) {
1521 mutex_unlock(&root->fs_info->trans_mutex);
1522 goto sleep;
1523 }
1524
1525 now = get_seconds();
1526 if (now < cur->start_time || now - cur->start_time < 30) {
1527 mutex_unlock(&root->fs_info->trans_mutex);
1528 delay = HZ * 5;
1529 goto sleep;
1530 }
1531 mutex_unlock(&root->fs_info->trans_mutex);
1532 trans = btrfs_start_transaction(root, 1);
1533 ret = btrfs_commit_transaction(trans, root);
1534
1535 sleep:
1536 wake_up_process(root->fs_info->cleaner_kthread);
1537 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1538
1539 if (freezing(current)) {
1540 refrigerator();
1541 } else {
1542 if (root->fs_info->closing)
1543 break;
1544 set_current_state(TASK_INTERRUPTIBLE);
1545 schedule_timeout(delay);
1546 __set_current_state(TASK_RUNNING);
1547 }
1548 } while (!kthread_should_stop());
1549 return 0;
1550 }
1551
1552 struct btrfs_root *open_ctree(struct super_block *sb,
1553 struct btrfs_fs_devices *fs_devices,
1554 char *options)
1555 {
1556 u32 sectorsize;
1557 u32 nodesize;
1558 u32 leafsize;
1559 u32 blocksize;
1560 u32 stripesize;
1561 u64 generation;
1562 u64 features;
1563 struct btrfs_key location;
1564 struct buffer_head *bh;
1565 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1566 GFP_NOFS);
1567 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1568 GFP_NOFS);
1569 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1570 GFP_NOFS);
1571 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1572 GFP_NOFS);
1573 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1574 GFP_NOFS);
1575 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1576 GFP_NOFS);
1577 struct btrfs_root *log_tree_root;
1578
1579 int ret;
1580 int err = -EINVAL;
1581
1582 struct btrfs_super_block *disk_super;
1583
1584 if (!extent_root || !tree_root || !fs_info ||
1585 !chunk_root || !dev_root || !csum_root) {
1586 err = -ENOMEM;
1587 goto fail;
1588 }
1589
1590 ret = init_srcu_struct(&fs_info->subvol_srcu);
1591 if (ret) {
1592 err = ret;
1593 goto fail;
1594 }
1595
1596 ret = setup_bdi(fs_info, &fs_info->bdi);
1597 if (ret) {
1598 err = ret;
1599 goto fail_srcu;
1600 }
1601
1602 fs_info->btree_inode = new_inode(sb);
1603 if (!fs_info->btree_inode) {
1604 err = -ENOMEM;
1605 goto fail_bdi;
1606 }
1607
1608 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1609 INIT_LIST_HEAD(&fs_info->trans_list);
1610 INIT_LIST_HEAD(&fs_info->dead_roots);
1611 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1612 INIT_LIST_HEAD(&fs_info->hashers);
1613 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1614 INIT_LIST_HEAD(&fs_info->ordered_operations);
1615 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1616 spin_lock_init(&fs_info->delalloc_lock);
1617 spin_lock_init(&fs_info->new_trans_lock);
1618 spin_lock_init(&fs_info->ref_cache_lock);
1619 spin_lock_init(&fs_info->fs_roots_radix_lock);
1620 spin_lock_init(&fs_info->delayed_iput_lock);
1621
1622 init_completion(&fs_info->kobj_unregister);
1623 fs_info->tree_root = tree_root;
1624 fs_info->extent_root = extent_root;
1625 fs_info->csum_root = csum_root;
1626 fs_info->chunk_root = chunk_root;
1627 fs_info->dev_root = dev_root;
1628 fs_info->fs_devices = fs_devices;
1629 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1630 INIT_LIST_HEAD(&fs_info->space_info);
1631 btrfs_mapping_init(&fs_info->mapping_tree);
1632 atomic_set(&fs_info->nr_async_submits, 0);
1633 atomic_set(&fs_info->async_delalloc_pages, 0);
1634 atomic_set(&fs_info->async_submit_draining, 0);
1635 atomic_set(&fs_info->nr_async_bios, 0);
1636 fs_info->sb = sb;
1637 fs_info->max_extent = (u64)-1;
1638 fs_info->max_inline = 8192 * 1024;
1639 fs_info->metadata_ratio = 0;
1640
1641 fs_info->thread_pool_size = min_t(unsigned long,
1642 num_online_cpus() + 2, 8);
1643
1644 INIT_LIST_HEAD(&fs_info->ordered_extents);
1645 spin_lock_init(&fs_info->ordered_extent_lock);
1646
1647 sb->s_blocksize = 4096;
1648 sb->s_blocksize_bits = blksize_bits(4096);
1649 sb->s_bdi = &fs_info->bdi;
1650
1651 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1652 fs_info->btree_inode->i_nlink = 1;
1653 /*
1654 * we set the i_size on the btree inode to the max possible int.
1655 * the real end of the address space is determined by all of
1656 * the devices in the system
1657 */
1658 fs_info->btree_inode->i_size = OFFSET_MAX;
1659 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1660 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1661
1662 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1663 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1664 fs_info->btree_inode->i_mapping,
1665 GFP_NOFS);
1666 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1667 GFP_NOFS);
1668
1669 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1670
1671 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1672 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1673 sizeof(struct btrfs_key));
1674 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1675 insert_inode_hash(fs_info->btree_inode);
1676
1677 spin_lock_init(&fs_info->block_group_cache_lock);
1678 fs_info->block_group_cache_tree = RB_ROOT;
1679
1680 extent_io_tree_init(&fs_info->freed_extents[0],
1681 fs_info->btree_inode->i_mapping, GFP_NOFS);
1682 extent_io_tree_init(&fs_info->freed_extents[1],
1683 fs_info->btree_inode->i_mapping, GFP_NOFS);
1684 fs_info->pinned_extents = &fs_info->freed_extents[0];
1685 fs_info->do_barriers = 1;
1686
1687
1688 mutex_init(&fs_info->trans_mutex);
1689 mutex_init(&fs_info->ordered_operations_mutex);
1690 mutex_init(&fs_info->tree_log_mutex);
1691 mutex_init(&fs_info->chunk_mutex);
1692 mutex_init(&fs_info->transaction_kthread_mutex);
1693 mutex_init(&fs_info->cleaner_mutex);
1694 mutex_init(&fs_info->volume_mutex);
1695 init_rwsem(&fs_info->extent_commit_sem);
1696 init_rwsem(&fs_info->cleanup_work_sem);
1697 init_rwsem(&fs_info->subvol_sem);
1698
1699 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1700 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1701
1702 init_waitqueue_head(&fs_info->transaction_throttle);
1703 init_waitqueue_head(&fs_info->transaction_wait);
1704 init_waitqueue_head(&fs_info->async_submit_wait);
1705
1706 __setup_root(4096, 4096, 4096, 4096, tree_root,
1707 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1708
1709
1710 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1711 if (!bh)
1712 goto fail_iput;
1713
1714 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1715 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1716 sizeof(fs_info->super_for_commit));
1717 brelse(bh);
1718
1719 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1720
1721 disk_super = &fs_info->super_copy;
1722 if (!btrfs_super_root(disk_super))
1723 goto fail_iput;
1724
1725 ret = btrfs_parse_options(tree_root, options);
1726 if (ret) {
1727 err = ret;
1728 goto fail_iput;
1729 }
1730
1731 features = btrfs_super_incompat_flags(disk_super) &
1732 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1733 if (features) {
1734 printk(KERN_ERR "BTRFS: couldn't mount because of "
1735 "unsupported optional features (%Lx).\n",
1736 (unsigned long long)features);
1737 err = -EINVAL;
1738 goto fail_iput;
1739 }
1740
1741 features = btrfs_super_incompat_flags(disk_super);
1742 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1743 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1744 btrfs_set_super_incompat_flags(disk_super, features);
1745 }
1746
1747 features = btrfs_super_compat_ro_flags(disk_super) &
1748 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1749 if (!(sb->s_flags & MS_RDONLY) && features) {
1750 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1751 "unsupported option features (%Lx).\n",
1752 (unsigned long long)features);
1753 err = -EINVAL;
1754 goto fail_iput;
1755 }
1756
1757 btrfs_init_workers(&fs_info->generic_worker,
1758 "genwork", 1, NULL);
1759
1760 btrfs_init_workers(&fs_info->workers, "worker",
1761 fs_info->thread_pool_size,
1762 &fs_info->generic_worker);
1763
1764 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1765 fs_info->thread_pool_size,
1766 &fs_info->generic_worker);
1767
1768 btrfs_init_workers(&fs_info->submit_workers, "submit",
1769 min_t(u64, fs_devices->num_devices,
1770 fs_info->thread_pool_size),
1771 &fs_info->generic_worker);
1772 btrfs_init_workers(&fs_info->enospc_workers, "enospc",
1773 fs_info->thread_pool_size,
1774 &fs_info->generic_worker);
1775
1776 /* a higher idle thresh on the submit workers makes it much more
1777 * likely that bios will be send down in a sane order to the
1778 * devices
1779 */
1780 fs_info->submit_workers.idle_thresh = 64;
1781
1782 fs_info->workers.idle_thresh = 16;
1783 fs_info->workers.ordered = 1;
1784
1785 fs_info->delalloc_workers.idle_thresh = 2;
1786 fs_info->delalloc_workers.ordered = 1;
1787
1788 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1789 &fs_info->generic_worker);
1790 btrfs_init_workers(&fs_info->endio_workers, "endio",
1791 fs_info->thread_pool_size,
1792 &fs_info->generic_worker);
1793 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1794 fs_info->thread_pool_size,
1795 &fs_info->generic_worker);
1796 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1797 "endio-meta-write", fs_info->thread_pool_size,
1798 &fs_info->generic_worker);
1799 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1800 fs_info->thread_pool_size,
1801 &fs_info->generic_worker);
1802
1803 /*
1804 * endios are largely parallel and should have a very
1805 * low idle thresh
1806 */
1807 fs_info->endio_workers.idle_thresh = 4;
1808 fs_info->endio_meta_workers.idle_thresh = 4;
1809
1810 fs_info->endio_write_workers.idle_thresh = 2;
1811 fs_info->endio_meta_write_workers.idle_thresh = 2;
1812
1813 btrfs_start_workers(&fs_info->workers, 1);
1814 btrfs_start_workers(&fs_info->generic_worker, 1);
1815 btrfs_start_workers(&fs_info->submit_workers, 1);
1816 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1817 btrfs_start_workers(&fs_info->fixup_workers, 1);
1818 btrfs_start_workers(&fs_info->endio_workers, 1);
1819 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1820 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1821 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1822 btrfs_start_workers(&fs_info->enospc_workers, 1);
1823
1824 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1825 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1826 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1827
1828 nodesize = btrfs_super_nodesize(disk_super);
1829 leafsize = btrfs_super_leafsize(disk_super);
1830 sectorsize = btrfs_super_sectorsize(disk_super);
1831 stripesize = btrfs_super_stripesize(disk_super);
1832 tree_root->nodesize = nodesize;
1833 tree_root->leafsize = leafsize;
1834 tree_root->sectorsize = sectorsize;
1835 tree_root->stripesize = stripesize;
1836
1837 sb->s_blocksize = sectorsize;
1838 sb->s_blocksize_bits = blksize_bits(sectorsize);
1839
1840 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1841 sizeof(disk_super->magic))) {
1842 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1843 goto fail_sb_buffer;
1844 }
1845
1846 mutex_lock(&fs_info->chunk_mutex);
1847 ret = btrfs_read_sys_array(tree_root);
1848 mutex_unlock(&fs_info->chunk_mutex);
1849 if (ret) {
1850 printk(KERN_WARNING "btrfs: failed to read the system "
1851 "array on %s\n", sb->s_id);
1852 goto fail_sb_buffer;
1853 }
1854
1855 blocksize = btrfs_level_size(tree_root,
1856 btrfs_super_chunk_root_level(disk_super));
1857 generation = btrfs_super_chunk_root_generation(disk_super);
1858
1859 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1860 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1861
1862 chunk_root->node = read_tree_block(chunk_root,
1863 btrfs_super_chunk_root(disk_super),
1864 blocksize, generation);
1865 BUG_ON(!chunk_root->node);
1866 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1867 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1868 sb->s_id);
1869 goto fail_chunk_root;
1870 }
1871 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1872 chunk_root->commit_root = btrfs_root_node(chunk_root);
1873
1874 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1875 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1876 BTRFS_UUID_SIZE);
1877
1878 mutex_lock(&fs_info->chunk_mutex);
1879 ret = btrfs_read_chunk_tree(chunk_root);
1880 mutex_unlock(&fs_info->chunk_mutex);
1881 if (ret) {
1882 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1883 sb->s_id);
1884 goto fail_chunk_root;
1885 }
1886
1887 btrfs_close_extra_devices(fs_devices);
1888
1889 blocksize = btrfs_level_size(tree_root,
1890 btrfs_super_root_level(disk_super));
1891 generation = btrfs_super_generation(disk_super);
1892
1893 tree_root->node = read_tree_block(tree_root,
1894 btrfs_super_root(disk_super),
1895 blocksize, generation);
1896 if (!tree_root->node)
1897 goto fail_chunk_root;
1898 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1899 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1900 sb->s_id);
1901 goto fail_tree_root;
1902 }
1903 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1904 tree_root->commit_root = btrfs_root_node(tree_root);
1905
1906 ret = find_and_setup_root(tree_root, fs_info,
1907 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1908 if (ret)
1909 goto fail_tree_root;
1910 extent_root->track_dirty = 1;
1911
1912 ret = find_and_setup_root(tree_root, fs_info,
1913 BTRFS_DEV_TREE_OBJECTID, dev_root);
1914 if (ret)
1915 goto fail_extent_root;
1916 dev_root->track_dirty = 1;
1917
1918 ret = find_and_setup_root(tree_root, fs_info,
1919 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1920 if (ret)
1921 goto fail_dev_root;
1922
1923 csum_root->track_dirty = 1;
1924
1925 btrfs_read_block_groups(extent_root);
1926
1927 fs_info->generation = generation;
1928 fs_info->last_trans_committed = generation;
1929 fs_info->data_alloc_profile = (u64)-1;
1930 fs_info->metadata_alloc_profile = (u64)-1;
1931 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1932 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1933 "btrfs-cleaner");
1934 if (IS_ERR(fs_info->cleaner_kthread))
1935 goto fail_csum_root;
1936
1937 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1938 tree_root,
1939 "btrfs-transaction");
1940 if (IS_ERR(fs_info->transaction_kthread))
1941 goto fail_cleaner;
1942
1943 if (!btrfs_test_opt(tree_root, SSD) &&
1944 !btrfs_test_opt(tree_root, NOSSD) &&
1945 !fs_info->fs_devices->rotating) {
1946 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1947 "mode\n");
1948 btrfs_set_opt(fs_info->mount_opt, SSD);
1949 }
1950
1951 if (btrfs_super_log_root(disk_super) != 0) {
1952 u64 bytenr = btrfs_super_log_root(disk_super);
1953
1954 if (fs_devices->rw_devices == 0) {
1955 printk(KERN_WARNING "Btrfs log replay required "
1956 "on RO media\n");
1957 err = -EIO;
1958 goto fail_trans_kthread;
1959 }
1960 blocksize =
1961 btrfs_level_size(tree_root,
1962 btrfs_super_log_root_level(disk_super));
1963
1964 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1965 GFP_NOFS);
1966
1967 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1968 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1969
1970 log_tree_root->node = read_tree_block(tree_root, bytenr,
1971 blocksize,
1972 generation + 1);
1973 ret = btrfs_recover_log_trees(log_tree_root);
1974 BUG_ON(ret);
1975
1976 if (sb->s_flags & MS_RDONLY) {
1977 ret = btrfs_commit_super(tree_root);
1978 BUG_ON(ret);
1979 }
1980 }
1981
1982 ret = btrfs_find_orphan_roots(tree_root);
1983 BUG_ON(ret);
1984
1985 if (!(sb->s_flags & MS_RDONLY)) {
1986 ret = btrfs_recover_relocation(tree_root);
1987 if (ret < 0) {
1988 printk(KERN_WARNING
1989 "btrfs: failed to recover relocation\n");
1990 err = -EINVAL;
1991 goto fail_trans_kthread;
1992 }
1993 }
1994
1995 location.objectid = BTRFS_FS_TREE_OBJECTID;
1996 location.type = BTRFS_ROOT_ITEM_KEY;
1997 location.offset = (u64)-1;
1998
1999 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2000 if (!fs_info->fs_root)
2001 goto fail_trans_kthread;
2002
2003 if (!(sb->s_flags & MS_RDONLY)) {
2004 down_read(&fs_info->cleanup_work_sem);
2005 btrfs_orphan_cleanup(fs_info->fs_root);
2006 up_read(&fs_info->cleanup_work_sem);
2007 }
2008
2009 return tree_root;
2010
2011 fail_trans_kthread:
2012 kthread_stop(fs_info->transaction_kthread);
2013 fail_cleaner:
2014 kthread_stop(fs_info->cleaner_kthread);
2015
2016 /*
2017 * make sure we're done with the btree inode before we stop our
2018 * kthreads
2019 */
2020 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2021 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2022
2023 fail_csum_root:
2024 free_extent_buffer(csum_root->node);
2025 free_extent_buffer(csum_root->commit_root);
2026 fail_dev_root:
2027 free_extent_buffer(dev_root->node);
2028 free_extent_buffer(dev_root->commit_root);
2029 fail_extent_root:
2030 free_extent_buffer(extent_root->node);
2031 free_extent_buffer(extent_root->commit_root);
2032 fail_tree_root:
2033 free_extent_buffer(tree_root->node);
2034 free_extent_buffer(tree_root->commit_root);
2035 fail_chunk_root:
2036 free_extent_buffer(chunk_root->node);
2037 free_extent_buffer(chunk_root->commit_root);
2038 fail_sb_buffer:
2039 btrfs_stop_workers(&fs_info->generic_worker);
2040 btrfs_stop_workers(&fs_info->fixup_workers);
2041 btrfs_stop_workers(&fs_info->delalloc_workers);
2042 btrfs_stop_workers(&fs_info->workers);
2043 btrfs_stop_workers(&fs_info->endio_workers);
2044 btrfs_stop_workers(&fs_info->endio_meta_workers);
2045 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2046 btrfs_stop_workers(&fs_info->endio_write_workers);
2047 btrfs_stop_workers(&fs_info->submit_workers);
2048 btrfs_stop_workers(&fs_info->enospc_workers);
2049 fail_iput:
2050 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2051 iput(fs_info->btree_inode);
2052
2053 btrfs_close_devices(fs_info->fs_devices);
2054 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2055 fail_bdi:
2056 bdi_destroy(&fs_info->bdi);
2057 fail_srcu:
2058 cleanup_srcu_struct(&fs_info->subvol_srcu);
2059 fail:
2060 kfree(extent_root);
2061 kfree(tree_root);
2062 kfree(fs_info);
2063 kfree(chunk_root);
2064 kfree(dev_root);
2065 kfree(csum_root);
2066 return ERR_PTR(err);
2067 }
2068
2069 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2070 {
2071 char b[BDEVNAME_SIZE];
2072
2073 if (uptodate) {
2074 set_buffer_uptodate(bh);
2075 } else {
2076 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
2077 printk(KERN_WARNING "lost page write due to "
2078 "I/O error on %s\n",
2079 bdevname(bh->b_bdev, b));
2080 }
2081 /* note, we dont' set_buffer_write_io_error because we have
2082 * our own ways of dealing with the IO errors
2083 */
2084 clear_buffer_uptodate(bh);
2085 }
2086 unlock_buffer(bh);
2087 put_bh(bh);
2088 }
2089
2090 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2091 {
2092 struct buffer_head *bh;
2093 struct buffer_head *latest = NULL;
2094 struct btrfs_super_block *super;
2095 int i;
2096 u64 transid = 0;
2097 u64 bytenr;
2098
2099 /* we would like to check all the supers, but that would make
2100 * a btrfs mount succeed after a mkfs from a different FS.
2101 * So, we need to add a special mount option to scan for
2102 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2103 */
2104 for (i = 0; i < 1; i++) {
2105 bytenr = btrfs_sb_offset(i);
2106 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2107 break;
2108 bh = __bread(bdev, bytenr / 4096, 4096);
2109 if (!bh)
2110 continue;
2111
2112 super = (struct btrfs_super_block *)bh->b_data;
2113 if (btrfs_super_bytenr(super) != bytenr ||
2114 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2115 sizeof(super->magic))) {
2116 brelse(bh);
2117 continue;
2118 }
2119
2120 if (!latest || btrfs_super_generation(super) > transid) {
2121 brelse(latest);
2122 latest = bh;
2123 transid = btrfs_super_generation(super);
2124 } else {
2125 brelse(bh);
2126 }
2127 }
2128 return latest;
2129 }
2130
2131 /*
2132 * this should be called twice, once with wait == 0 and
2133 * once with wait == 1. When wait == 0 is done, all the buffer heads
2134 * we write are pinned.
2135 *
2136 * They are released when wait == 1 is done.
2137 * max_mirrors must be the same for both runs, and it indicates how
2138 * many supers on this one device should be written.
2139 *
2140 * max_mirrors == 0 means to write them all.
2141 */
2142 static int write_dev_supers(struct btrfs_device *device,
2143 struct btrfs_super_block *sb,
2144 int do_barriers, int wait, int max_mirrors)
2145 {
2146 struct buffer_head *bh;
2147 int i;
2148 int ret;
2149 int errors = 0;
2150 u32 crc;
2151 u64 bytenr;
2152 int last_barrier = 0;
2153
2154 if (max_mirrors == 0)
2155 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2156
2157 /* make sure only the last submit_bh does a barrier */
2158 if (do_barriers) {
2159 for (i = 0; i < max_mirrors; i++) {
2160 bytenr = btrfs_sb_offset(i);
2161 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2162 device->total_bytes)
2163 break;
2164 last_barrier = i;
2165 }
2166 }
2167
2168 for (i = 0; i < max_mirrors; i++) {
2169 bytenr = btrfs_sb_offset(i);
2170 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2171 break;
2172
2173 if (wait) {
2174 bh = __find_get_block(device->bdev, bytenr / 4096,
2175 BTRFS_SUPER_INFO_SIZE);
2176 BUG_ON(!bh);
2177 wait_on_buffer(bh);
2178 if (!buffer_uptodate(bh))
2179 errors++;
2180
2181 /* drop our reference */
2182 brelse(bh);
2183
2184 /* drop the reference from the wait == 0 run */
2185 brelse(bh);
2186 continue;
2187 } else {
2188 btrfs_set_super_bytenr(sb, bytenr);
2189
2190 crc = ~(u32)0;
2191 crc = btrfs_csum_data(NULL, (char *)sb +
2192 BTRFS_CSUM_SIZE, crc,
2193 BTRFS_SUPER_INFO_SIZE -
2194 BTRFS_CSUM_SIZE);
2195 btrfs_csum_final(crc, sb->csum);
2196
2197 /*
2198 * one reference for us, and we leave it for the
2199 * caller
2200 */
2201 bh = __getblk(device->bdev, bytenr / 4096,
2202 BTRFS_SUPER_INFO_SIZE);
2203 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2204
2205 /* one reference for submit_bh */
2206 get_bh(bh);
2207
2208 set_buffer_uptodate(bh);
2209 lock_buffer(bh);
2210 bh->b_end_io = btrfs_end_buffer_write_sync;
2211 }
2212
2213 if (i == last_barrier && do_barriers && device->barriers) {
2214 ret = submit_bh(WRITE_BARRIER, bh);
2215 if (ret == -EOPNOTSUPP) {
2216 printk("btrfs: disabling barriers on dev %s\n",
2217 device->name);
2218 set_buffer_uptodate(bh);
2219 device->barriers = 0;
2220 /* one reference for submit_bh */
2221 get_bh(bh);
2222 lock_buffer(bh);
2223 ret = submit_bh(WRITE_SYNC, bh);
2224 }
2225 } else {
2226 ret = submit_bh(WRITE_SYNC, bh);
2227 }
2228
2229 if (ret)
2230 errors++;
2231 }
2232 return errors < i ? 0 : -1;
2233 }
2234
2235 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2236 {
2237 struct list_head *head;
2238 struct btrfs_device *dev;
2239 struct btrfs_super_block *sb;
2240 struct btrfs_dev_item *dev_item;
2241 int ret;
2242 int do_barriers;
2243 int max_errors;
2244 int total_errors = 0;
2245 u64 flags;
2246
2247 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2248 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2249
2250 sb = &root->fs_info->super_for_commit;
2251 dev_item = &sb->dev_item;
2252
2253 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2254 head = &root->fs_info->fs_devices->devices;
2255 list_for_each_entry(dev, head, dev_list) {
2256 if (!dev->bdev) {
2257 total_errors++;
2258 continue;
2259 }
2260 if (!dev->in_fs_metadata || !dev->writeable)
2261 continue;
2262
2263 btrfs_set_stack_device_generation(dev_item, 0);
2264 btrfs_set_stack_device_type(dev_item, dev->type);
2265 btrfs_set_stack_device_id(dev_item, dev->devid);
2266 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2267 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2268 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2269 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2270 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2271 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2272 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2273
2274 flags = btrfs_super_flags(sb);
2275 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2276
2277 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2278 if (ret)
2279 total_errors++;
2280 }
2281 if (total_errors > max_errors) {
2282 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2283 total_errors);
2284 BUG();
2285 }
2286
2287 total_errors = 0;
2288 list_for_each_entry(dev, head, dev_list) {
2289 if (!dev->bdev)
2290 continue;
2291 if (!dev->in_fs_metadata || !dev->writeable)
2292 continue;
2293
2294 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2295 if (ret)
2296 total_errors++;
2297 }
2298 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2299 if (total_errors > max_errors) {
2300 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2301 total_errors);
2302 BUG();
2303 }
2304 return 0;
2305 }
2306
2307 int write_ctree_super(struct btrfs_trans_handle *trans,
2308 struct btrfs_root *root, int max_mirrors)
2309 {
2310 int ret;
2311
2312 ret = write_all_supers(root, max_mirrors);
2313 return ret;
2314 }
2315
2316 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2317 {
2318 spin_lock(&fs_info->fs_roots_radix_lock);
2319 radix_tree_delete(&fs_info->fs_roots_radix,
2320 (unsigned long)root->root_key.objectid);
2321 spin_unlock(&fs_info->fs_roots_radix_lock);
2322
2323 if (btrfs_root_refs(&root->root_item) == 0)
2324 synchronize_srcu(&fs_info->subvol_srcu);
2325
2326 free_fs_root(root);
2327 return 0;
2328 }
2329
2330 static void free_fs_root(struct btrfs_root *root)
2331 {
2332 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2333 if (root->anon_super.s_dev) {
2334 down_write(&root->anon_super.s_umount);
2335 kill_anon_super(&root->anon_super);
2336 }
2337 free_extent_buffer(root->node);
2338 free_extent_buffer(root->commit_root);
2339 kfree(root->name);
2340 kfree(root);
2341 }
2342
2343 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2344 {
2345 int ret;
2346 struct btrfs_root *gang[8];
2347 int i;
2348
2349 while (!list_empty(&fs_info->dead_roots)) {
2350 gang[0] = list_entry(fs_info->dead_roots.next,
2351 struct btrfs_root, root_list);
2352 list_del(&gang[0]->root_list);
2353
2354 if (gang[0]->in_radix) {
2355 btrfs_free_fs_root(fs_info, gang[0]);
2356 } else {
2357 free_extent_buffer(gang[0]->node);
2358 free_extent_buffer(gang[0]->commit_root);
2359 kfree(gang[0]);
2360 }
2361 }
2362
2363 while (1) {
2364 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2365 (void **)gang, 0,
2366 ARRAY_SIZE(gang));
2367 if (!ret)
2368 break;
2369 for (i = 0; i < ret; i++)
2370 btrfs_free_fs_root(fs_info, gang[i]);
2371 }
2372 return 0;
2373 }
2374
2375 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2376 {
2377 u64 root_objectid = 0;
2378 struct btrfs_root *gang[8];
2379 int i;
2380 int ret;
2381
2382 while (1) {
2383 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2384 (void **)gang, root_objectid,
2385 ARRAY_SIZE(gang));
2386 if (!ret)
2387 break;
2388
2389 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2390 for (i = 0; i < ret; i++) {
2391 root_objectid = gang[i]->root_key.objectid;
2392 btrfs_orphan_cleanup(gang[i]);
2393 }
2394 root_objectid++;
2395 }
2396 return 0;
2397 }
2398
2399 int btrfs_commit_super(struct btrfs_root *root)
2400 {
2401 struct btrfs_trans_handle *trans;
2402 int ret;
2403
2404 mutex_lock(&root->fs_info->cleaner_mutex);
2405 btrfs_run_delayed_iputs(root);
2406 btrfs_clean_old_snapshots(root);
2407 mutex_unlock(&root->fs_info->cleaner_mutex);
2408
2409 /* wait until ongoing cleanup work done */
2410 down_write(&root->fs_info->cleanup_work_sem);
2411 up_write(&root->fs_info->cleanup_work_sem);
2412
2413 trans = btrfs_start_transaction(root, 1);
2414 ret = btrfs_commit_transaction(trans, root);
2415 BUG_ON(ret);
2416 /* run commit again to drop the original snapshot */
2417 trans = btrfs_start_transaction(root, 1);
2418 btrfs_commit_transaction(trans, root);
2419 ret = btrfs_write_and_wait_transaction(NULL, root);
2420 BUG_ON(ret);
2421
2422 ret = write_ctree_super(NULL, root, 0);
2423 return ret;
2424 }
2425
2426 int close_ctree(struct btrfs_root *root)
2427 {
2428 struct btrfs_fs_info *fs_info = root->fs_info;
2429 int ret;
2430
2431 fs_info->closing = 1;
2432 smp_mb();
2433
2434 kthread_stop(root->fs_info->transaction_kthread);
2435 kthread_stop(root->fs_info->cleaner_kthread);
2436
2437 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2438 ret = btrfs_commit_super(root);
2439 if (ret)
2440 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2441 }
2442
2443 fs_info->closing = 2;
2444 smp_mb();
2445
2446 if (fs_info->delalloc_bytes) {
2447 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2448 (unsigned long long)fs_info->delalloc_bytes);
2449 }
2450 if (fs_info->total_ref_cache_size) {
2451 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2452 (unsigned long long)fs_info->total_ref_cache_size);
2453 }
2454
2455 free_extent_buffer(fs_info->extent_root->node);
2456 free_extent_buffer(fs_info->extent_root->commit_root);
2457 free_extent_buffer(fs_info->tree_root->node);
2458 free_extent_buffer(fs_info->tree_root->commit_root);
2459 free_extent_buffer(root->fs_info->chunk_root->node);
2460 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2461 free_extent_buffer(root->fs_info->dev_root->node);
2462 free_extent_buffer(root->fs_info->dev_root->commit_root);
2463 free_extent_buffer(root->fs_info->csum_root->node);
2464 free_extent_buffer(root->fs_info->csum_root->commit_root);
2465
2466 btrfs_free_block_groups(root->fs_info);
2467
2468 del_fs_roots(fs_info);
2469
2470 iput(fs_info->btree_inode);
2471
2472 btrfs_stop_workers(&fs_info->generic_worker);
2473 btrfs_stop_workers(&fs_info->fixup_workers);
2474 btrfs_stop_workers(&fs_info->delalloc_workers);
2475 btrfs_stop_workers(&fs_info->workers);
2476 btrfs_stop_workers(&fs_info->endio_workers);
2477 btrfs_stop_workers(&fs_info->endio_meta_workers);
2478 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2479 btrfs_stop_workers(&fs_info->endio_write_workers);
2480 btrfs_stop_workers(&fs_info->submit_workers);
2481 btrfs_stop_workers(&fs_info->enospc_workers);
2482
2483 btrfs_close_devices(fs_info->fs_devices);
2484 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2485
2486 bdi_destroy(&fs_info->bdi);
2487 cleanup_srcu_struct(&fs_info->subvol_srcu);
2488
2489 kfree(fs_info->extent_root);
2490 kfree(fs_info->tree_root);
2491 kfree(fs_info->chunk_root);
2492 kfree(fs_info->dev_root);
2493 kfree(fs_info->csum_root);
2494 return 0;
2495 }
2496
2497 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2498 {
2499 int ret;
2500 struct inode *btree_inode = buf->first_page->mapping->host;
2501
2502 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2503 NULL);
2504 if (!ret)
2505 return ret;
2506
2507 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2508 parent_transid);
2509 return !ret;
2510 }
2511
2512 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2513 {
2514 struct inode *btree_inode = buf->first_page->mapping->host;
2515 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2516 buf);
2517 }
2518
2519 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2520 {
2521 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2522 u64 transid = btrfs_header_generation(buf);
2523 struct inode *btree_inode = root->fs_info->btree_inode;
2524 int was_dirty;
2525
2526 btrfs_assert_tree_locked(buf);
2527 if (transid != root->fs_info->generation) {
2528 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2529 "found %llu running %llu\n",
2530 (unsigned long long)buf->start,
2531 (unsigned long long)transid,
2532 (unsigned long long)root->fs_info->generation);
2533 WARN_ON(1);
2534 }
2535 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2536 buf);
2537 if (!was_dirty) {
2538 spin_lock(&root->fs_info->delalloc_lock);
2539 root->fs_info->dirty_metadata_bytes += buf->len;
2540 spin_unlock(&root->fs_info->delalloc_lock);
2541 }
2542 }
2543
2544 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2545 {
2546 /*
2547 * looks as though older kernels can get into trouble with
2548 * this code, they end up stuck in balance_dirty_pages forever
2549 */
2550 u64 num_dirty;
2551 unsigned long thresh = 32 * 1024 * 1024;
2552
2553 if (current->flags & PF_MEMALLOC)
2554 return;
2555
2556 num_dirty = root->fs_info->dirty_metadata_bytes;
2557
2558 if (num_dirty > thresh) {
2559 balance_dirty_pages_ratelimited_nr(
2560 root->fs_info->btree_inode->i_mapping, 1);
2561 }
2562 return;
2563 }
2564
2565 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2566 {
2567 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2568 int ret;
2569 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2570 if (ret == 0)
2571 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2572 return ret;
2573 }
2574
2575 int btree_lock_page_hook(struct page *page)
2576 {
2577 struct inode *inode = page->mapping->host;
2578 struct btrfs_root *root = BTRFS_I(inode)->root;
2579 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2580 struct extent_buffer *eb;
2581 unsigned long len;
2582 u64 bytenr = page_offset(page);
2583
2584 if (page->private == EXTENT_PAGE_PRIVATE)
2585 goto out;
2586
2587 len = page->private >> 2;
2588 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2589 if (!eb)
2590 goto out;
2591
2592 btrfs_tree_lock(eb);
2593 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2594
2595 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2596 spin_lock(&root->fs_info->delalloc_lock);
2597 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2598 root->fs_info->dirty_metadata_bytes -= eb->len;
2599 else
2600 WARN_ON(1);
2601 spin_unlock(&root->fs_info->delalloc_lock);
2602 }
2603
2604 btrfs_tree_unlock(eb);
2605 free_extent_buffer(eb);
2606 out:
2607 lock_page(page);
2608 return 0;
2609 }
2610
2611 static struct extent_io_ops btree_extent_io_ops = {
2612 .write_cache_pages_lock_hook = btree_lock_page_hook,
2613 .readpage_end_io_hook = btree_readpage_end_io_hook,
2614 .submit_bio_hook = btree_submit_bio_hook,
2615 /* note we're sharing with inode.c for the merge bio hook */
2616 .merge_bio_hook = btrfs_merge_bio_hook,
2617 };
kernel source for telekom puls (alcatel/mediatek)