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code style scripts/checkpatch.pl (linux-3.9-rc1) formatting
[linux-2.6.34.14-moxart.git] / fs / btrfs / disk-io.c
blobfa46c2d53c264e77822d1d61b807c5dc7eee1460
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 struct btrfs_work work;
78 };
79
80 /* These are used to set the lockdep class on the extent buffer locks.
81 * The class is set by the readpage_end_io_hook after the buffer has
82 * passed csum validation but before the pages are unlocked.
83 *
84 * The lockdep class is also set by btrfs_init_new_buffer on freshly
85 * allocated blocks.
86 *
87 * The class is based on the level in the tree block, which allows lockdep
88 * to know that lower nodes nest inside the locks of higher nodes.
89 *
90 * We also add a check to make sure the highest level of the tree is
91 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
92 * code needs update as well.
93 */
94 #ifdef CONFIG_DEBUG_LOCK_ALLOC
95 # if BTRFS_MAX_LEVEL != 8
96 # error
97 # endif
98 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
99 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
100 /* leaf */
101 "btrfs-extent-00",
102 "btrfs-extent-01",
103 "btrfs-extent-02",
104 "btrfs-extent-03",
105 "btrfs-extent-04",
106 "btrfs-extent-05",
107 "btrfs-extent-06",
108 "btrfs-extent-07",
109 /* highest possible level */
110 "btrfs-extent-08",
111 };
112 #endif
113
114 /*
115 * extents on the btree inode are pretty simple, there's one extent
116 * that covers the entire device
117 */
118 static struct extent_map *btree_get_extent(struct inode *inode,
119 struct page *page, size_t page_offset, u64 start, u64 len,
120 int create)
121 {
122 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
123 struct extent_map *em;
124 int ret;
125
126 read_lock(&em_tree->lock);
127 em = lookup_extent_mapping(em_tree, start, len);
128 if (em) {
129 em->bdev =
130 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
131 read_unlock(&em_tree->lock);
132 goto out;
133 }
134 read_unlock(&em_tree->lock);
135
136 em = alloc_extent_map(GFP_NOFS);
137 if (!em) {
138 em = ERR_PTR(-ENOMEM);
139 goto out;
140 }
141 em->start = 0;
142 em->len = (u64)-1;
143 em->block_len = (u64)-1;
144 em->block_start = 0;
145 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
146
147 write_lock(&em_tree->lock);
148 ret = add_extent_mapping(em_tree, em);
149 if (ret == -EEXIST) {
150 u64 failed_start = em->start;
151 u64 failed_len = em->len;
152
153 free_extent_map(em);
154 em = lookup_extent_mapping(em_tree, start, len);
155 if (em) {
156 ret = 0;
157 } else {
158 em = lookup_extent_mapping(em_tree, failed_start,
159 failed_len);
160 ret = -EIO;
161 }
162 } else if (ret) {
163 free_extent_map(em);
164 em = NULL;
165 }
166 write_unlock(&em_tree->lock);
167
168 if (ret)
169 em = ERR_PTR(ret);
170 out:
171 return em;
172 }
173
174 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
175 {
176 return crc32c(seed, data, len);
177 }
178
179 void btrfs_csum_final(u32 crc, char *result)
180 {
181 *(__le32 *)result = ~cpu_to_le32(crc);
182 }
183
184 /*
185 * compute the csum for a btree block, and either verify it or write it
186 * into the csum field of the block.
187 */
188 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
189 int verify)
190 {
191 u16 csum_size =
192 btrfs_super_csum_size(&root->fs_info->super_copy);
193 char *result = NULL;
194 unsigned long len;
195 unsigned long cur_len;
196 unsigned long offset = BTRFS_CSUM_SIZE;
197 char *map_token = NULL;
198 char *kaddr;
199 unsigned long map_start;
200 unsigned long map_len;
201 int err;
202 u32 crc = ~(u32)0;
203 unsigned long inline_result;
204
205 len = buf->len - offset;
206 while (len > 0) {
207 err = map_private_extent_buffer(buf, offset, 32,
208 &map_token, &kaddr,
209 &map_start, &map_len, KM_USER0);
210 if (err)
211 return 1;
212 cur_len = min(len, map_len - (offset - map_start));
213 crc = btrfs_csum_data(root, kaddr + offset - map_start,
214 crc, cur_len);
215 len -= cur_len;
216 offset += cur_len;
217 unmap_extent_buffer(buf, map_token, KM_USER0);
218 }
219 if (csum_size > sizeof(inline_result)) {
220 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
221 if (!result)
222 return 1;
223 } else {
224 result = (char *)&inline_result;
225 }
226
227 btrfs_csum_final(crc, result);
228
229 if (verify) {
230 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
231 u32 val;
232 u32 found = 0;
233 memcpy(&found, result, csum_size);
234
235 read_extent_buffer(buf, &val, 0, csum_size);
236 if (printk_ratelimit()) {
237 printk(KERN_INFO "btrfs: %s checksum verify "
238 "failed on %llu wanted %X found %X "
239 "level %d\n",
240 root->fs_info->sb->s_id,
241 (unsigned long long)buf->start, val, found,
242 btrfs_header_level(buf));
243 }
244 if (result != (char *)&inline_result)
245 kfree(result);
246 return 1;
247 }
248 } else {
249 write_extent_buffer(buf, result, 0, csum_size);
250 }
251 if (result != (char *)&inline_result)
252 kfree(result);
253 return 0;
254 }
255
256 /*
257 * we can't consider a given block up to date unless the transid of the
258 * block matches the transid in the parent node's pointer. This is how we
259 * detect blocks that either didn't get written at all or got written
260 * in the wrong place.
261 */
262 static int verify_parent_transid(struct extent_io_tree *io_tree,
263 struct extent_buffer *eb, u64 parent_transid)
264 {
265 struct extent_state *cached_state = NULL;
266 int ret;
267
268 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
269 return 0;
270
271 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
272 0, &cached_state, GFP_NOFS);
273 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
274 btrfs_header_generation(eb) == parent_transid) {
275 ret = 0;
276 goto out;
277 }
278 if (printk_ratelimit()) {
279 printk("parent transid verify failed on %llu wanted %llu "
280 "found %llu\n",
281 (unsigned long long)eb->start,
282 (unsigned long long)parent_transid,
283 (unsigned long long)btrfs_header_generation(eb));
284 }
285 ret = 1;
286 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
287 out:
288 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
289 &cached_state, GFP_NOFS);
290 return ret;
291 }
292
293 /*
294 * helper to read a given tree block, doing retries as required when
295 * the checksums don't match and we have alternate mirrors to try.
296 */
297 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
298 struct extent_buffer *eb,
299 u64 start, u64 parent_transid)
300 {
301 struct extent_io_tree *io_tree;
302 int ret;
303 int num_copies = 0;
304 int mirror_num = 0;
305
306 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
307 while (1) {
308 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
309 btree_get_extent, mirror_num);
310 if (!ret &&
311 !verify_parent_transid(io_tree, eb, parent_transid))
312 return ret;
313
314 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
315 eb->start, eb->len);
316 if (num_copies == 1)
317 return ret;
318
319 mirror_num++;
320 if (mirror_num > num_copies)
321 return ret;
322 }
323 return -EIO;
324 }
325
326 /*
327 * checksum a dirty tree block before IO. This has extra checks to make sure
328 * we only fill in the checksum field in the first page of a multi-page block
329 */
330
331 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
332 {
333 struct extent_io_tree *tree;
334 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
335 u64 found_start;
336 int found_level;
337 unsigned long len;
338 struct extent_buffer *eb;
339 int ret;
340
341 tree = &BTRFS_I(page->mapping->host)->io_tree;
342
343 if (page->private == EXTENT_PAGE_PRIVATE)
344 goto out;
345 if (!page->private)
346 goto out;
347 len = page->private >> 2;
348 WARN_ON(len == 0);
349
350 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
351 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
352 btrfs_header_generation(eb));
353 BUG_ON(ret);
354 found_start = btrfs_header_bytenr(eb);
355 if (found_start != start) {
356 WARN_ON(1);
357 goto err;
358 }
359 if (eb->first_page != page) {
360 WARN_ON(1);
361 goto err;
362 }
363 if (!PageUptodate(page)) {
364 WARN_ON(1);
365 goto err;
366 }
367 found_level = btrfs_header_level(eb);
368
369 csum_tree_block(root, eb, 0);
370 err:
371 free_extent_buffer(eb);
372 out:
373 return 0;
374 }
375
376 static int check_tree_block_fsid(struct btrfs_root *root,
377 struct extent_buffer *eb)
378 {
379 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
380 u8 fsid[BTRFS_UUID_SIZE];
381 int ret = 1;
382
383 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
384 BTRFS_FSID_SIZE);
385 while (fs_devices) {
386 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
387 ret = 0;
388 break;
389 }
390 fs_devices = fs_devices->seed;
391 }
392 return ret;
393 }
394
395 #ifdef CONFIG_DEBUG_LOCK_ALLOC
396 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
397 {
398 lockdep_set_class_and_name(&eb->lock,
399 &btrfs_eb_class[level],
400 btrfs_eb_name[level]);
401 }
402 #endif
403
404 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
405 struct extent_state *state)
406 {
407 struct extent_io_tree *tree;
408 u64 found_start;
409 int found_level;
410 unsigned long len;
411 struct extent_buffer *eb;
412 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
413 int ret = 0;
414
415 tree = &BTRFS_I(page->mapping->host)->io_tree;
416 if (page->private == EXTENT_PAGE_PRIVATE)
417 goto out;
418 if (!page->private)
419 goto out;
420
421 len = page->private >> 2;
422 WARN_ON(len == 0);
423
424 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
425
426 found_start = btrfs_header_bytenr(eb);
427 if (found_start != start) {
428 if (printk_ratelimit()) {
429 printk(KERN_INFO "btrfs bad tree block start "
430 "%llu %llu\n",
431 (unsigned long long)found_start,
432 (unsigned long long)eb->start);
433 }
434 ret = -EIO;
435 goto err;
436 }
437 if (eb->first_page != page) {
438 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
439 eb->first_page->index, page->index);
440 WARN_ON(1);
441 ret = -EIO;
442 goto err;
443 }
444 if (check_tree_block_fsid(root, eb)) {
445 if (printk_ratelimit()) {
446 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
447 (unsigned long long)eb->start);
448 }
449 ret = -EIO;
450 goto err;
451 }
452 found_level = btrfs_header_level(eb);
453
454 btrfs_set_buffer_lockdep_class(eb, found_level);
455
456 ret = csum_tree_block(root, eb, 1);
457 if (ret)
458 ret = -EIO;
459
460 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
461 end = eb->start + end - 1;
462 err:
463 free_extent_buffer(eb);
464 out:
465 return ret;
466 }
467
468 static void end_workqueue_bio(struct bio *bio, int err)
469 {
470 struct end_io_wq *end_io_wq = bio->bi_private;
471 struct btrfs_fs_info *fs_info;
472
473 fs_info = end_io_wq->info;
474 end_io_wq->error = err;
475 end_io_wq->work.func = end_workqueue_fn;
476 end_io_wq->work.flags = 0;
477
478 if (bio->bi_rw & (1 << BIO_RW)) {
479 if (end_io_wq->metadata)
480 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
481 &end_io_wq->work);
482 else
483 btrfs_queue_worker(&fs_info->endio_write_workers,
484 &end_io_wq->work);
485 } else {
486 if (end_io_wq->metadata)
487 btrfs_queue_worker(&fs_info->endio_meta_workers,
488 &end_io_wq->work);
489 else
490 btrfs_queue_worker(&fs_info->endio_workers,
491 &end_io_wq->work);
492 }
493 }
494
495 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
496 int metadata)
497 {
498 struct end_io_wq *end_io_wq;
499 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
500 if (!end_io_wq)
501 return -ENOMEM;
502
503 end_io_wq->private = bio->bi_private;
504 end_io_wq->end_io = bio->bi_end_io;
505 end_io_wq->info = info;
506 end_io_wq->error = 0;
507 end_io_wq->bio = bio;
508 end_io_wq->metadata = metadata;
509
510 bio->bi_private = end_io_wq;
511 bio->bi_end_io = end_workqueue_bio;
512 return 0;
513 }
514
515 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
516 {
517 unsigned long limit = min_t(unsigned long,
518 info->workers.max_workers,
519 info->fs_devices->open_devices);
520 return 256 * limit;
521 }
522
523 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
524 {
525 return atomic_read(&info->nr_async_bios) >
526 btrfs_async_submit_limit(info);
527 }
528
529 static void run_one_async_start(struct btrfs_work *work)
530 {
531 struct btrfs_fs_info *fs_info;
532 struct async_submit_bio *async;
533
534 async = container_of(work, struct async_submit_bio, work);
535 fs_info = BTRFS_I(async->inode)->root->fs_info;
536 async->submit_bio_start(async->inode, async->rw, async->bio,
537 async->mirror_num, async->bio_flags);
538 }
539
540 static void run_one_async_done(struct btrfs_work *work)
541 {
542 struct btrfs_fs_info *fs_info;
543 struct async_submit_bio *async;
544 int limit;
545
546 async = container_of(work, struct async_submit_bio, work);
547 fs_info = BTRFS_I(async->inode)->root->fs_info;
548
549 limit = btrfs_async_submit_limit(fs_info);
550 limit = limit * 2 / 3;
551
552 atomic_dec(&fs_info->nr_async_submits);
553
554 if (atomic_read(&fs_info->nr_async_submits) < limit &&
555 waitqueue_active(&fs_info->async_submit_wait))
556 wake_up(&fs_info->async_submit_wait);
557
558 async->submit_bio_done(async->inode, async->rw, async->bio,
559 async->mirror_num, async->bio_flags);
560 }
561
562 static void run_one_async_free(struct btrfs_work *work)
563 {
564 struct async_submit_bio *async;
565
566 async = container_of(work, struct async_submit_bio, work);
567 kfree(async);
568 }
569
570 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
571 int rw, struct bio *bio, int mirror_num,
572 unsigned long bio_flags,
573 extent_submit_bio_hook_t *submit_bio_start,
574 extent_submit_bio_hook_t *submit_bio_done)
575 {
576 struct async_submit_bio *async;
577
578 async = kmalloc(sizeof(*async), GFP_NOFS);
579 if (!async)
580 return -ENOMEM;
581
582 async->inode = inode;
583 async->rw = rw;
584 async->bio = bio;
585 async->mirror_num = mirror_num;
586 async->submit_bio_start = submit_bio_start;
587 async->submit_bio_done = submit_bio_done;
588
589 async->work.func = run_one_async_start;
590 async->work.ordered_func = run_one_async_done;
591 async->work.ordered_free = run_one_async_free;
592
593 async->work.flags = 0;
594 async->bio_flags = bio_flags;
595
596 atomic_inc(&fs_info->nr_async_submits);
597
598 if (rw & (1 << BIO_RW_SYNCIO))
599 btrfs_set_work_high_prio(&async->work);
600
601 btrfs_queue_worker(&fs_info->workers, &async->work);
602
603 while (atomic_read(&fs_info->async_submit_draining) &&
604 atomic_read(&fs_info->nr_async_submits)) {
605 wait_event(fs_info->async_submit_wait,
606 (atomic_read(&fs_info->nr_async_submits) == 0));
607 }
608
609 return 0;
610 }
611
612 static int btree_csum_one_bio(struct bio *bio)
613 {
614 struct bio_vec *bvec = bio->bi_io_vec;
615 int bio_index = 0;
616 struct btrfs_root *root;
617
618 WARN_ON(bio->bi_vcnt <= 0);
619 while (bio_index < bio->bi_vcnt) {
620 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
621 csum_dirty_buffer(root, bvec->bv_page);
622 bio_index++;
623 bvec++;
624 }
625 return 0;
626 }
627
628 static int __btree_submit_bio_start(struct inode *inode, int rw,
629 struct bio *bio, int mirror_num,
630 unsigned long bio_flags)
631 {
632 /*
633 * when we're called for a write, we're already in the async
634 * submission context. Just jump into btrfs_map_bio
635 */
636 btree_csum_one_bio(bio);
637 return 0;
638 }
639
640 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
641 int mirror_num, unsigned long bio_flags)
642 {
643 /*
644 * when we're called for a write, we're already in the async
645 * submission context. Just jump into btrfs_map_bio
646 */
647 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
648 }
649
650 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
651 int mirror_num, unsigned long bio_flags)
652 {
653 int ret;
654
655 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
656 bio, 1);
657 BUG_ON(ret);
658
659 if (!(rw & (1 << BIO_RW))) {
660 /*
661 * called for a read, do the setup so that checksum validation
662 * can happen in the async kernel threads
663 */
664 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
665 mirror_num, 0);
666 }
667
668 /*
669 * kthread helpers are used to submit writes so that checksumming
670 * can happen in parallel across all CPUs
671 */
672 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
673 inode, rw, bio, mirror_num, 0,
674 __btree_submit_bio_start,
675 __btree_submit_bio_done);
676 }
677
678 static int btree_writepage(struct page *page, struct writeback_control *wbc)
679 {
680 struct extent_io_tree *tree;
681 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
682 struct extent_buffer *eb;
683 int was_dirty;
684
685 tree = &BTRFS_I(page->mapping->host)->io_tree;
686 if (!(current->flags & PF_MEMALLOC)) {
687 return extent_write_full_page(tree, page,
688 btree_get_extent, wbc);
689 }
690
691 redirty_page_for_writepage(wbc, page);
692 eb = btrfs_find_tree_block(root, page_offset(page),
693 PAGE_CACHE_SIZE);
694 WARN_ON(!eb);
695
696 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
697 if (!was_dirty) {
698 spin_lock(&root->fs_info->delalloc_lock);
699 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
700 spin_unlock(&root->fs_info->delalloc_lock);
701 }
702 free_extent_buffer(eb);
703
704 unlock_page(page);
705 return 0;
706 }
707
708 static int btree_writepages(struct address_space *mapping,
709 struct writeback_control *wbc)
710 {
711 struct extent_io_tree *tree;
712 tree = &BTRFS_I(mapping->host)->io_tree;
713 if (wbc->sync_mode == WB_SYNC_NONE) {
714 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
715 u64 num_dirty;
716 unsigned long thresh = 32 * 1024 * 1024;
717
718 if (wbc->for_kupdate)
719 return 0;
720
721 /* this is a bit racy, but that's ok */
722 num_dirty = root->fs_info->dirty_metadata_bytes;
723 if (num_dirty < thresh)
724 return 0;
725 }
726 return extent_writepages(tree, mapping, btree_get_extent, wbc);
727 }
728
729 static int btree_readpage(struct file *file, struct page *page)
730 {
731 struct extent_io_tree *tree;
732 tree = &BTRFS_I(page->mapping->host)->io_tree;
733 return extent_read_full_page(tree, page, btree_get_extent);
734 }
735
736 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
737 {
738 struct extent_io_tree *tree;
739 struct extent_map_tree *map;
740 int ret;
741
742 if (PageWriteback(page) || PageDirty(page))
743 return 0;
744
745 tree = &BTRFS_I(page->mapping->host)->io_tree;
746 map = &BTRFS_I(page->mapping->host)->extent_tree;
747
748 ret = try_release_extent_state(map, tree, page, gfp_flags);
749 if (!ret)
750 return 0;
751
752 ret = try_release_extent_buffer(tree, page);
753 if (ret == 1) {
754 ClearPagePrivate(page);
755 set_page_private(page, 0);
756 page_cache_release(page);
757 }
758
759 return ret;
760 }
761
762 static void btree_invalidatepage(struct page *page, unsigned long offset)
763 {
764 struct extent_io_tree *tree;
765 tree = &BTRFS_I(page->mapping->host)->io_tree;
766 extent_invalidatepage(tree, page, offset);
767 btree_releasepage(page, GFP_NOFS);
768 if (PagePrivate(page)) {
769 printk(KERN_WARNING "btrfs warning page private not zero "
770 "on page %llu\n", (unsigned long long)page_offset(page));
771 ClearPagePrivate(page);
772 set_page_private(page, 0);
773 page_cache_release(page);
774 }
775 }
776
777 static const struct address_space_operations btree_aops = {
778 .readpage = btree_readpage,
779 .writepage = btree_writepage,
780 .writepages = btree_writepages,
781 .releasepage = btree_releasepage,
782 .invalidatepage = btree_invalidatepage,
783 .sync_page = block_sync_page,
784 };
785
786 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
787 u64 parent_transid)
788 {
789 struct extent_buffer *buf = NULL;
790 struct inode *btree_inode = root->fs_info->btree_inode;
791 int ret = 0;
792
793 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
794 if (!buf)
795 return 0;
796 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
797 buf, 0, 0, btree_get_extent, 0);
798 free_extent_buffer(buf);
799 return ret;
800 }
801
802 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
803 u64 bytenr, u32 blocksize)
804 {
805 struct inode *btree_inode = root->fs_info->btree_inode;
806 struct extent_buffer *eb;
807 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
808 bytenr, blocksize, GFP_NOFS);
809 return eb;
810 }
811
812 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
813 u64 bytenr, u32 blocksize)
814 {
815 struct inode *btree_inode = root->fs_info->btree_inode;
816 struct extent_buffer *eb;
817
818 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
819 bytenr, blocksize, NULL, GFP_NOFS);
820 return eb;
821 }
822
823
824 int btrfs_write_tree_block(struct extent_buffer *buf)
825 {
826 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
827 buf->start + buf->len - 1);
828 }
829
830 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
831 {
832 return filemap_fdatawait_range(buf->first_page->mapping,
833 buf->start, buf->start + buf->len - 1);
834 }
835
836 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
837 u32 blocksize, u64 parent_transid)
838 {
839 struct extent_buffer *buf = NULL;
840 struct inode *btree_inode = root->fs_info->btree_inode;
841 struct extent_io_tree *io_tree;
842 int ret;
843
844 io_tree = &BTRFS_I(btree_inode)->io_tree;
845
846 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
847 if (!buf)
848 return NULL;
849
850 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
851
852 if (ret == 0)
853 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
854 return buf;
855
856 }
857
858 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
859 struct extent_buffer *buf)
860 {
861 struct inode *btree_inode = root->fs_info->btree_inode;
862 if (btrfs_header_generation(buf) ==
863 root->fs_info->running_transaction->transid) {
864 btrfs_assert_tree_locked(buf);
865
866 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
867 spin_lock(&root->fs_info->delalloc_lock);
868 if (root->fs_info->dirty_metadata_bytes >= buf->len)
869 root->fs_info->dirty_metadata_bytes -= buf->len;
870 else
871 WARN_ON(1);
872 spin_unlock(&root->fs_info->delalloc_lock);
873 }
874
875 /* ugh, clear_extent_buffer_dirty needs to lock the page */
876 btrfs_set_lock_blocking(buf);
877 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
878 buf);
879 }
880 return 0;
881 }
882
883 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
884 u32 stripesize, struct btrfs_root *root,
885 struct btrfs_fs_info *fs_info,
886 u64 objectid)
887 {
888 root->node = NULL;
889 root->commit_root = NULL;
890 root->sectorsize = sectorsize;
891 root->nodesize = nodesize;
892 root->leafsize = leafsize;
893 root->stripesize = stripesize;
894 root->ref_cows = 0;
895 root->track_dirty = 0;
896 root->in_radix = 0;
897 root->clean_orphans = 0;
898
899 root->fs_info = fs_info;
900 root->objectid = objectid;
901 root->last_trans = 0;
902 root->highest_objectid = 0;
903 root->name = NULL;
904 root->in_sysfs = 0;
905 root->inode_tree = RB_ROOT;
906
907 INIT_LIST_HEAD(&root->dirty_list);
908 INIT_LIST_HEAD(&root->orphan_list);
909 INIT_LIST_HEAD(&root->root_list);
910 spin_lock_init(&root->node_lock);
911 spin_lock_init(&root->list_lock);
912 spin_lock_init(&root->inode_lock);
913 mutex_init(&root->objectid_mutex);
914 mutex_init(&root->log_mutex);
915 init_waitqueue_head(&root->log_writer_wait);
916 init_waitqueue_head(&root->log_commit_wait[0]);
917 init_waitqueue_head(&root->log_commit_wait[1]);
918 atomic_set(&root->log_commit[0], 0);
919 atomic_set(&root->log_commit[1], 0);
920 atomic_set(&root->log_writers, 0);
921 root->log_batch = 0;
922 root->log_transid = 0;
923 root->last_log_commit = 0;
924 extent_io_tree_init(&root->dirty_log_pages,
925 fs_info->btree_inode->i_mapping, GFP_NOFS);
926
927 memset(&root->root_key, 0, sizeof(root->root_key));
928 memset(&root->root_item, 0, sizeof(root->root_item));
929 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
930 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
931 root->defrag_trans_start = fs_info->generation;
932 init_completion(&root->kobj_unregister);
933 root->defrag_running = 0;
934 root->root_key.objectid = objectid;
935 root->anon_super.s_root = NULL;
936 root->anon_super.s_dev = 0;
937 INIT_LIST_HEAD(&root->anon_super.s_list);
938 INIT_LIST_HEAD(&root->anon_super.s_instances);
939 init_rwsem(&root->anon_super.s_umount);
940
941 return 0;
942 }
943
944 static int find_and_setup_root(struct btrfs_root *tree_root,
945 struct btrfs_fs_info *fs_info,
946 u64 objectid,
947 struct btrfs_root *root)
948 {
949 int ret;
950 u32 blocksize;
951 u64 generation;
952
953 __setup_root(tree_root->nodesize, tree_root->leafsize,
954 tree_root->sectorsize, tree_root->stripesize,
955 root, fs_info, objectid);
956 ret = btrfs_find_last_root(tree_root, objectid,
957 &root->root_item, &root->root_key);
958 if (ret > 0)
959 return -ENOENT;
960 BUG_ON(ret);
961
962 generation = btrfs_root_generation(&root->root_item);
963 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
964 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
965 blocksize, generation);
966 BUG_ON(!root->node);
967 root->commit_root = btrfs_root_node(root);
968 return 0;
969 }
970
971 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
972 struct btrfs_fs_info *fs_info)
973 {
974 struct extent_buffer *eb;
975 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
976 u64 start = 0;
977 u64 end = 0;
978 int ret;
979
980 if (!log_root_tree)
981 return 0;
982
983 while (1) {
984 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
985 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
986 if (ret)
987 break;
988
989 clear_extent_bits(&log_root_tree->dirty_log_pages, start, end,
990 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
991 }
992 eb = fs_info->log_root_tree->node;
993
994 WARN_ON(btrfs_header_level(eb) != 0);
995 WARN_ON(btrfs_header_nritems(eb) != 0);
996
997 ret = btrfs_free_reserved_extent(fs_info->tree_root,
998 eb->start, eb->len);
999 BUG_ON(ret);
1000
1001 free_extent_buffer(eb);
1002 kfree(fs_info->log_root_tree);
1003 fs_info->log_root_tree = NULL;
1004 return 0;
1005 }
1006
1007 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1008 struct btrfs_fs_info *fs_info)
1009 {
1010 struct btrfs_root *root;
1011 struct btrfs_root *tree_root = fs_info->tree_root;
1012 struct extent_buffer *leaf;
1013
1014 root = kzalloc(sizeof(*root), GFP_NOFS);
1015 if (!root)
1016 return ERR_PTR(-ENOMEM);
1017
1018 __setup_root(tree_root->nodesize, tree_root->leafsize,
1019 tree_root->sectorsize, tree_root->stripesize,
1020 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1021
1022 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1023 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1024 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1025 /*
1026 * log trees do not get reference counted because they go away
1027 * before a real commit is actually done. They do store pointers
1028 * to file data extents, and those reference counts still get
1029 * updated (along with back refs to the log tree).
1030 */
1031 root->ref_cows = 0;
1032
1033 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1034 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1035 if (IS_ERR(leaf)) {
1036 kfree(root);
1037 return ERR_CAST(leaf);
1038 }
1039
1040 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1041 btrfs_set_header_bytenr(leaf, leaf->start);
1042 btrfs_set_header_generation(leaf, trans->transid);
1043 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1044 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1045 root->node = leaf;
1046
1047 write_extent_buffer(root->node, root->fs_info->fsid,
1048 (unsigned long)btrfs_header_fsid(root->node),
1049 BTRFS_FSID_SIZE);
1050 btrfs_mark_buffer_dirty(root->node);
1051 btrfs_tree_unlock(root->node);
1052 return root;
1053 }
1054
1055 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1056 struct btrfs_fs_info *fs_info)
1057 {
1058 struct btrfs_root *log_root;
1059
1060 log_root = alloc_log_tree(trans, fs_info);
1061 if (IS_ERR(log_root))
1062 return PTR_ERR(log_root);
1063 WARN_ON(fs_info->log_root_tree);
1064 fs_info->log_root_tree = log_root;
1065 return 0;
1066 }
1067
1068 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1069 struct btrfs_root *root)
1070 {
1071 struct btrfs_root *log_root;
1072 struct btrfs_inode_item *inode_item;
1073
1074 log_root = alloc_log_tree(trans, root->fs_info);
1075 if (IS_ERR(log_root))
1076 return PTR_ERR(log_root);
1077
1078 log_root->last_trans = trans->transid;
1079 log_root->root_key.offset = root->root_key.objectid;
1080
1081 inode_item = &log_root->root_item.inode;
1082 inode_item->generation = cpu_to_le64(1);
1083 inode_item->size = cpu_to_le64(3);
1084 inode_item->nlink = cpu_to_le32(1);
1085 inode_item->nbytes = cpu_to_le64(root->leafsize);
1086 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1087
1088 btrfs_set_root_node(&log_root->root_item, log_root->node);
1089
1090 WARN_ON(root->log_root);
1091 root->log_root = log_root;
1092 root->log_transid = 0;
1093 root->last_log_commit = 0;
1094 return 0;
1095 }
1096
1097 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1098 struct btrfs_key *location)
1099 {
1100 struct btrfs_root *root;
1101 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1102 struct btrfs_path *path;
1103 struct extent_buffer *l;
1104 u64 generation;
1105 u32 blocksize;
1106 int ret = 0;
1107
1108 root = kzalloc(sizeof(*root), GFP_NOFS);
1109 if (!root)
1110 return ERR_PTR(-ENOMEM);
1111 if (location->offset == (u64)-1) {
1112 ret = find_and_setup_root(tree_root, fs_info,
1113 location->objectid, root);
1114 if (ret) {
1115 kfree(root);
1116 return ERR_PTR(ret);
1117 }
1118 goto out;
1119 }
1120
1121 __setup_root(tree_root->nodesize, tree_root->leafsize,
1122 tree_root->sectorsize, tree_root->stripesize,
1123 root, fs_info, location->objectid);
1124
1125 path = btrfs_alloc_path();
1126 BUG_ON(!path);
1127 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1128 if (ret == 0) {
1129 l = path->nodes[0];
1130 read_extent_buffer(l, &root->root_item,
1131 btrfs_item_ptr_offset(l, path->slots[0]),
1132 sizeof(root->root_item));
1133 memcpy(&root->root_key, location, sizeof(*location));
1134 }
1135 btrfs_free_path(path);
1136 if (ret) {
1137 if (ret > 0)
1138 ret = -ENOENT;
1139 return ERR_PTR(ret);
1140 }
1141
1142 generation = btrfs_root_generation(&root->root_item);
1143 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1144 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1145 blocksize, generation);
1146 root->commit_root = btrfs_root_node(root);
1147 BUG_ON(!root->node);
1148 out:
1149 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1150 root->ref_cows = 1;
1151 btrfs_check_and_init_root_item(&root->root_item);
1152 }
1153
1154 return root;
1155 }
1156
1157 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1158 u64 root_objectid)
1159 {
1160 struct btrfs_root *root;
1161
1162 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1163 return fs_info->tree_root;
1164 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1165 return fs_info->extent_root;
1166
1167 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1168 (unsigned long)root_objectid);
1169 return root;
1170 }
1171
1172 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1173 struct btrfs_key *location)
1174 {
1175 struct btrfs_root *root;
1176 int ret;
1177
1178 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1179 return fs_info->tree_root;
1180 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1181 return fs_info->extent_root;
1182 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1183 return fs_info->chunk_root;
1184 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1185 return fs_info->dev_root;
1186 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1187 return fs_info->csum_root;
1188 again:
1189 spin_lock(&fs_info->fs_roots_radix_lock);
1190 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1191 (unsigned long)location->objectid);
1192 spin_unlock(&fs_info->fs_roots_radix_lock);
1193 if (root)
1194 return root;
1195
1196 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1197 if (ret == 0)
1198 ret = -ENOENT;
1199 if (ret < 0)
1200 return ERR_PTR(ret);
1201
1202 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1203 if (IS_ERR(root))
1204 return root;
1205
1206 WARN_ON(btrfs_root_refs(&root->root_item) == 0);
1207 set_anon_super(&root->anon_super, NULL);
1208
1209 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1210 if (ret)
1211 goto fail;
1212
1213 spin_lock(&fs_info->fs_roots_radix_lock);
1214 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1215 (unsigned long)root->root_key.objectid,
1216 root);
1217 if (ret == 0) {
1218 root->in_radix = 1;
1219 root->clean_orphans = 1;
1220 }
1221 spin_unlock(&fs_info->fs_roots_radix_lock);
1222 radix_tree_preload_end();
1223 if (ret) {
1224 if (ret == -EEXIST) {
1225 free_fs_root(root);
1226 goto again;
1227 }
1228 goto fail;
1229 }
1230
1231 ret = btrfs_find_dead_roots(fs_info->tree_root,
1232 root->root_key.objectid);
1233 WARN_ON(ret);
1234 return root;
1235 fail:
1236 free_fs_root(root);
1237 return ERR_PTR(ret);
1238 }
1239
1240 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1241 struct btrfs_key *location,
1242 const char *name, int namelen)
1243 {
1244 return btrfs_read_fs_root_no_name(fs_info, location);
1245 #if 0
1246 struct btrfs_root *root;
1247 int ret;
1248
1249 root = btrfs_read_fs_root_no_name(fs_info, location);
1250 if (!root)
1251 return NULL;
1252
1253 if (root->in_sysfs)
1254 return root;
1255
1256 ret = btrfs_set_root_name(root, name, namelen);
1257 if (ret) {
1258 free_extent_buffer(root->node);
1259 kfree(root);
1260 return ERR_PTR(ret);
1261 }
1262
1263 ret = btrfs_sysfs_add_root(root);
1264 if (ret) {
1265 free_extent_buffer(root->node);
1266 kfree(root->name);
1267 kfree(root);
1268 return ERR_PTR(ret);
1269 }
1270 root->in_sysfs = 1;
1271 return root;
1272 #endif
1273 }
1274
1275 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1276 {
1277 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1278 int ret = 0;
1279 struct btrfs_device *device;
1280 struct backing_dev_info *bdi;
1281
1282 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1283 if (!device->bdev)
1284 continue;
1285 bdi = blk_get_backing_dev_info(device->bdev);
1286 if (bdi && bdi_congested(bdi, bdi_bits)) {
1287 ret = 1;
1288 break;
1289 }
1290 }
1291 return ret;
1292 }
1293
1294 /*
1295 * this unplugs every device on the box, and it is only used when page
1296 * is null
1297 */
1298 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1299 {
1300 struct btrfs_device *device;
1301 struct btrfs_fs_info *info;
1302
1303 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1304 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1305 if (!device->bdev)
1306 continue;
1307
1308 bdi = blk_get_backing_dev_info(device->bdev);
1309 if (bdi->unplug_io_fn)
1310 bdi->unplug_io_fn(bdi, page);
1311 }
1312 }
1313
1314 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1315 {
1316 struct inode *inode;
1317 struct extent_map_tree *em_tree;
1318 struct extent_map *em;
1319 struct address_space *mapping;
1320 u64 offset;
1321
1322 /* the generic O_DIRECT read code does this */
1323 if (1 || !page) {
1324 __unplug_io_fn(bdi, page);
1325 return;
1326 }
1327
1328 /*
1329 * page->mapping may change at any time. Get a consistent copy
1330 * and use that for everything below
1331 */
1332 smp_mb();
1333 mapping = page->mapping;
1334 if (!mapping)
1335 return;
1336
1337 inode = mapping->host;
1338
1339 /*
1340 * don't do the expensive searching for a small number of
1341 * devices
1342 */
1343 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1344 __unplug_io_fn(bdi, page);
1345 return;
1346 }
1347
1348 offset = page_offset(page);
1349
1350 em_tree = &BTRFS_I(inode)->extent_tree;
1351 read_lock(&em_tree->lock);
1352 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1353 read_unlock(&em_tree->lock);
1354 if (!em) {
1355 __unplug_io_fn(bdi, page);
1356 return;
1357 }
1358
1359 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1360 free_extent_map(em);
1361 __unplug_io_fn(bdi, page);
1362 return;
1363 }
1364 offset = offset - em->start;
1365 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1366 em->block_start + offset, page);
1367 free_extent_map(em);
1368 }
1369
1370 /*
1371 * If this fails, caller must call bdi_destroy() to get rid of the
1372 * bdi again.
1373 */
1374 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1375 {
1376 int err;
1377
1378 bdi->capabilities = BDI_CAP_MAP_COPY;
1379 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1380 if (err)
1381 return err;
1382
1383 bdi->ra_pages = default_backing_dev_info.ra_pages;
1384 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1385 bdi->unplug_io_data = info;
1386 bdi->congested_fn = btrfs_congested_fn;
1387 bdi->congested_data = info;
1388 return 0;
1389 }
1390
1391 static int bio_ready_for_csum(struct bio *bio)
1392 {
1393 u64 length = 0;
1394 u64 buf_len = 0;
1395 u64 start = 0;
1396 struct page *page;
1397 struct extent_io_tree *io_tree = NULL;
1398 struct btrfs_fs_info *info = NULL;
1399 struct bio_vec *bvec;
1400 int i;
1401 int ret;
1402
1403 bio_for_each_segment(bvec, bio, i) {
1404 page = bvec->bv_page;
1405 if (page->private == EXTENT_PAGE_PRIVATE) {
1406 length += bvec->bv_len;
1407 continue;
1408 }
1409 if (!page->private) {
1410 length += bvec->bv_len;
1411 continue;
1412 }
1413 length = bvec->bv_len;
1414 buf_len = page->private >> 2;
1415 start = page_offset(page) + bvec->bv_offset;
1416 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1417 info = BTRFS_I(page->mapping->host)->root->fs_info;
1418 }
1419 /* are we fully contained in this bio? */
1420 if (buf_len <= length)
1421 return 1;
1422
1423 ret = extent_range_uptodate(io_tree, start + length,
1424 start + buf_len - 1);
1425 return ret;
1426 }
1427
1428 /*
1429 * called by the kthread helper functions to finally call the bio end_io
1430 * functions. This is where read checksum verification actually happens
1431 */
1432 static void end_workqueue_fn(struct btrfs_work *work)
1433 {
1434 struct bio *bio;
1435 struct end_io_wq *end_io_wq;
1436 struct btrfs_fs_info *fs_info;
1437 int error;
1438
1439 end_io_wq = container_of(work, struct end_io_wq, work);
1440 bio = end_io_wq->bio;
1441 fs_info = end_io_wq->info;
1442
1443 /* metadata bio reads are special because the whole tree block must
1444 * be checksummed at once. This makes sure the entire block is in
1445 * ram and up to date before trying to verify things. For
1446 * blocksize <= pagesize, it is basically a noop
1447 */
1448 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1449 !bio_ready_for_csum(bio)) {
1450 btrfs_queue_worker(&fs_info->endio_meta_workers,
1451 &end_io_wq->work);
1452 return;
1453 }
1454 error = end_io_wq->error;
1455 bio->bi_private = end_io_wq->private;
1456 bio->bi_end_io = end_io_wq->end_io;
1457 kfree(end_io_wq);
1458 bio_endio(bio, error);
1459 }
1460
1461 static int cleaner_kthread(void *arg)
1462 {
1463 struct btrfs_root *root = arg;
1464
1465 do {
1466 smp_mb();
1467 if (root->fs_info->closing)
1468 break;
1469
1470 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1471
1472 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1473 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1474 btrfs_run_delayed_iputs(root);
1475 btrfs_clean_old_snapshots(root);
1476 mutex_unlock(&root->fs_info->cleaner_mutex);
1477 }
1478
1479 if (freezing(current)) {
1480 refrigerator();
1481 } else {
1482 smp_mb();
1483 if (root->fs_info->closing)
1484 break;
1485 set_current_state(TASK_INTERRUPTIBLE);
1486 schedule();
1487 __set_current_state(TASK_RUNNING);
1488 }
1489 } while (!kthread_should_stop());
1490 return 0;
1491 }
1492
1493 static int transaction_kthread(void *arg)
1494 {
1495 struct btrfs_root *root = arg;
1496 struct btrfs_trans_handle *trans;
1497 struct btrfs_transaction *cur;
1498 unsigned long now;
1499 unsigned long delay;
1500 int ret;
1501
1502 do {
1503 smp_mb();
1504 if (root->fs_info->closing)
1505 break;
1506
1507 delay = HZ * 30;
1508 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1509 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1510
1511 mutex_lock(&root->fs_info->trans_mutex);
1512 cur = root->fs_info->running_transaction;
1513 if (!cur) {
1514 mutex_unlock(&root->fs_info->trans_mutex);
1515 goto sleep;
1516 }
1517
1518 now = get_seconds();
1519 if (now < cur->start_time || now - cur->start_time < 30) {
1520 mutex_unlock(&root->fs_info->trans_mutex);
1521 delay = HZ * 5;
1522 goto sleep;
1523 }
1524 mutex_unlock(&root->fs_info->trans_mutex);
1525 trans = btrfs_start_transaction(root, 1);
1526 ret = btrfs_commit_transaction(trans, root);
1527
1528 sleep:
1529 wake_up_process(root->fs_info->cleaner_kthread);
1530 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1531
1532 if (freezing(current)) {
1533 refrigerator();
1534 } else {
1535 if (root->fs_info->closing)
1536 break;
1537 set_current_state(TASK_INTERRUPTIBLE);
1538 schedule_timeout(delay);
1539 __set_current_state(TASK_RUNNING);
1540 }
1541 } while (!kthread_should_stop());
1542 return 0;
1543 }
1544
1545 struct btrfs_root *open_ctree(struct super_block *sb,
1546 struct btrfs_fs_devices *fs_devices,
1547 char *options)
1548 {
1549 u32 sectorsize;
1550 u32 nodesize;
1551 u32 leafsize;
1552 u32 blocksize;
1553 u32 stripesize;
1554 u64 generation;
1555 u64 features;
1556 struct btrfs_key location;
1557 struct buffer_head *bh;
1558 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1559 GFP_NOFS);
1560 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1561 GFP_NOFS);
1562 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1563 GFP_NOFS);
1564 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1565 GFP_NOFS);
1566 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1567 GFP_NOFS);
1568 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1569 GFP_NOFS);
1570 struct btrfs_root *log_tree_root;
1571
1572 int ret;
1573 int err = -EINVAL;
1574
1575 struct btrfs_super_block *disk_super;
1576
1577 if (!extent_root || !tree_root || !fs_info ||
1578 !chunk_root || !dev_root || !csum_root) {
1579 err = -ENOMEM;
1580 goto fail;
1581 }
1582
1583 ret = init_srcu_struct(&fs_info->subvol_srcu);
1584 if (ret) {
1585 err = ret;
1586 goto fail;
1587 }
1588
1589 ret = setup_bdi(fs_info, &fs_info->bdi);
1590 if (ret) {
1591 err = ret;
1592 goto fail_srcu;
1593 }
1594
1595 fs_info->btree_inode = new_inode(sb);
1596 if (!fs_info->btree_inode) {
1597 err = -ENOMEM;
1598 goto fail_bdi;
1599 }
1600
1601 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1602 INIT_LIST_HEAD(&fs_info->trans_list);
1603 INIT_LIST_HEAD(&fs_info->dead_roots);
1604 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1605 INIT_LIST_HEAD(&fs_info->hashers);
1606 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1607 INIT_LIST_HEAD(&fs_info->ordered_operations);
1608 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1609 spin_lock_init(&fs_info->delalloc_lock);
1610 spin_lock_init(&fs_info->new_trans_lock);
1611 spin_lock_init(&fs_info->ref_cache_lock);
1612 spin_lock_init(&fs_info->fs_roots_radix_lock);
1613 spin_lock_init(&fs_info->delayed_iput_lock);
1614
1615 init_completion(&fs_info->kobj_unregister);
1616 fs_info->tree_root = tree_root;
1617 fs_info->extent_root = extent_root;
1618 fs_info->csum_root = csum_root;
1619 fs_info->chunk_root = chunk_root;
1620 fs_info->dev_root = dev_root;
1621 fs_info->fs_devices = fs_devices;
1622 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1623 INIT_LIST_HEAD(&fs_info->space_info);
1624 btrfs_mapping_init(&fs_info->mapping_tree);
1625 atomic_set(&fs_info->nr_async_submits, 0);
1626 atomic_set(&fs_info->async_delalloc_pages, 0);
1627 atomic_set(&fs_info->async_submit_draining, 0);
1628 atomic_set(&fs_info->nr_async_bios, 0);
1629 fs_info->sb = sb;
1630 fs_info->max_inline = 8192 * 1024;
1631 fs_info->metadata_ratio = 0;
1632
1633 fs_info->thread_pool_size = min_t(unsigned long,
1634 num_online_cpus() + 2, 8);
1635
1636 INIT_LIST_HEAD(&fs_info->ordered_extents);
1637 spin_lock_init(&fs_info->ordered_extent_lock);
1638
1639 sb->s_blocksize = 4096;
1640 sb->s_blocksize_bits = blksize_bits(4096);
1641 sb->s_bdi = &fs_info->bdi;
1642
1643 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1644 fs_info->btree_inode->i_nlink = 1;
1645 /*
1646 * we set the i_size on the btree inode to the max possible int.
1647 * the real end of the address space is determined by all of
1648 * the devices in the system
1649 */
1650 fs_info->btree_inode->i_size = OFFSET_MAX;
1651 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1652 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1653
1654 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1655 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1656 fs_info->btree_inode->i_mapping,
1657 GFP_NOFS);
1658 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1659 GFP_NOFS);
1660
1661 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1662
1663 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1664 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1665 sizeof(struct btrfs_key));
1666 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1667 insert_inode_hash(fs_info->btree_inode);
1668
1669 spin_lock_init(&fs_info->block_group_cache_lock);
1670 fs_info->block_group_cache_tree = RB_ROOT;
1671
1672 extent_io_tree_init(&fs_info->freed_extents[0],
1673 fs_info->btree_inode->i_mapping, GFP_NOFS);
1674 extent_io_tree_init(&fs_info->freed_extents[1],
1675 fs_info->btree_inode->i_mapping, GFP_NOFS);
1676 fs_info->pinned_extents = &fs_info->freed_extents[0];
1677 fs_info->do_barriers = 1;
1678
1679
1680 mutex_init(&fs_info->trans_mutex);
1681 mutex_init(&fs_info->ordered_operations_mutex);
1682 mutex_init(&fs_info->tree_log_mutex);
1683 mutex_init(&fs_info->chunk_mutex);
1684 mutex_init(&fs_info->transaction_kthread_mutex);
1685 mutex_init(&fs_info->cleaner_mutex);
1686 mutex_init(&fs_info->volume_mutex);
1687 init_rwsem(&fs_info->extent_commit_sem);
1688 init_rwsem(&fs_info->cleanup_work_sem);
1689 init_rwsem(&fs_info->subvol_sem);
1690
1691 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1692 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1693
1694 init_waitqueue_head(&fs_info->transaction_throttle);
1695 init_waitqueue_head(&fs_info->transaction_wait);
1696 init_waitqueue_head(&fs_info->async_submit_wait);
1697
1698 __setup_root(4096, 4096, 4096, 4096, tree_root,
1699 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1700
1701
1702 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1703 if (!bh)
1704 goto fail_iput;
1705
1706 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1707 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1708 sizeof(fs_info->super_for_commit));
1709 brelse(bh);
1710
1711 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1712
1713 disk_super = &fs_info->super_copy;
1714 if (!btrfs_super_root(disk_super))
1715 goto fail_iput;
1716
1717 ret = btrfs_parse_options(tree_root, options);
1718 if (ret) {
1719 err = ret;
1720 goto fail_iput;
1721 }
1722
1723 features = btrfs_super_incompat_flags(disk_super) &
1724 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1725 if (features) {
1726 printk(KERN_ERR "BTRFS: couldn't mount because of "
1727 "unsupported optional features (%Lx).\n",
1728 (unsigned long long)features);
1729 err = -EINVAL;
1730 goto fail_iput;
1731 }
1732
1733 features = btrfs_super_incompat_flags(disk_super);
1734 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1735 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1736 btrfs_set_super_incompat_flags(disk_super, features);
1737 }
1738
1739 features = btrfs_super_compat_ro_flags(disk_super) &
1740 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1741 if (!(sb->s_flags & MS_RDONLY) && features) {
1742 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1743 "unsupported option features (%Lx).\n",
1744 (unsigned long long)features);
1745 err = -EINVAL;
1746 goto fail_iput;
1747 }
1748
1749 btrfs_init_workers(&fs_info->generic_worker,
1750 "genwork", 1, NULL);
1751
1752 btrfs_init_workers(&fs_info->workers, "worker",
1753 fs_info->thread_pool_size,
1754 &fs_info->generic_worker);
1755
1756 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1757 fs_info->thread_pool_size,
1758 &fs_info->generic_worker);
1759
1760 btrfs_init_workers(&fs_info->submit_workers, "submit",
1761 min_t(u64, fs_devices->num_devices,
1762 fs_info->thread_pool_size),
1763 &fs_info->generic_worker);
1764 btrfs_init_workers(&fs_info->enospc_workers, "enospc",
1765 fs_info->thread_pool_size,
1766 &fs_info->generic_worker);
1767
1768 /* a higher idle thresh on the submit workers makes it much more
1769 * likely that bios will be send down in a sane order to the
1770 * devices
1771 */
1772 fs_info->submit_workers.idle_thresh = 64;
1773
1774 fs_info->workers.idle_thresh = 16;
1775 fs_info->workers.ordered = 1;
1776
1777 fs_info->delalloc_workers.idle_thresh = 2;
1778 fs_info->delalloc_workers.ordered = 1;
1779
1780 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1781 &fs_info->generic_worker);
1782 btrfs_init_workers(&fs_info->endio_workers, "endio",
1783 fs_info->thread_pool_size,
1784 &fs_info->generic_worker);
1785 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1786 fs_info->thread_pool_size,
1787 &fs_info->generic_worker);
1788 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1789 "endio-meta-write", fs_info->thread_pool_size,
1790 &fs_info->generic_worker);
1791 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1792 fs_info->thread_pool_size,
1793 &fs_info->generic_worker);
1794
1795 /*
1796 * endios are largely parallel and should have a very
1797 * low idle thresh
1798 */
1799 fs_info->endio_workers.idle_thresh = 4;
1800 fs_info->endio_meta_workers.idle_thresh = 4;
1801
1802 fs_info->endio_write_workers.idle_thresh = 2;
1803 fs_info->endio_meta_write_workers.idle_thresh = 2;
1804
1805 btrfs_start_workers(&fs_info->workers, 1);
1806 btrfs_start_workers(&fs_info->generic_worker, 1);
1807 btrfs_start_workers(&fs_info->submit_workers, 1);
1808 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1809 btrfs_start_workers(&fs_info->fixup_workers, 1);
1810 btrfs_start_workers(&fs_info->endio_workers, 1);
1811 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1812 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1813 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1814 btrfs_start_workers(&fs_info->enospc_workers, 1);
1815
1816 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1817 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1818 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1819
1820 nodesize = btrfs_super_nodesize(disk_super);
1821 leafsize = btrfs_super_leafsize(disk_super);
1822 sectorsize = btrfs_super_sectorsize(disk_super);
1823 stripesize = btrfs_super_stripesize(disk_super);
1824 tree_root->nodesize = nodesize;
1825 tree_root->leafsize = leafsize;
1826 tree_root->sectorsize = sectorsize;
1827 tree_root->stripesize = stripesize;
1828
1829 sb->s_blocksize = sectorsize;
1830 sb->s_blocksize_bits = blksize_bits(sectorsize);
1831
1832 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1833 sizeof(disk_super->magic))) {
1834 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1835 goto fail_sb_buffer;
1836 }
1837
1838 mutex_lock(&fs_info->chunk_mutex);
1839 ret = btrfs_read_sys_array(tree_root);
1840 mutex_unlock(&fs_info->chunk_mutex);
1841 if (ret) {
1842 printk(KERN_WARNING "btrfs: failed to read the system "
1843 "array on %s\n", sb->s_id);
1844 goto fail_sb_buffer;
1845 }
1846
1847 blocksize = btrfs_level_size(tree_root,
1848 btrfs_super_chunk_root_level(disk_super));
1849 generation = btrfs_super_chunk_root_generation(disk_super);
1850
1851 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1852 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1853
1854 chunk_root->node = read_tree_block(chunk_root,
1855 btrfs_super_chunk_root(disk_super),
1856 blocksize, generation);
1857 BUG_ON(!chunk_root->node);
1858 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1859 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1860 sb->s_id);
1861 goto fail_chunk_root;
1862 }
1863 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1864 chunk_root->commit_root = btrfs_root_node(chunk_root);
1865
1866 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1867 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1868 BTRFS_UUID_SIZE);
1869
1870 mutex_lock(&fs_info->chunk_mutex);
1871 ret = btrfs_read_chunk_tree(chunk_root);
1872 mutex_unlock(&fs_info->chunk_mutex);
1873 if (ret) {
1874 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1875 sb->s_id);
1876 goto fail_chunk_root;
1877 }
1878
1879 btrfs_close_extra_devices(fs_devices);
1880
1881 blocksize = btrfs_level_size(tree_root,
1882 btrfs_super_root_level(disk_super));
1883 generation = btrfs_super_generation(disk_super);
1884
1885 tree_root->node = read_tree_block(tree_root,
1886 btrfs_super_root(disk_super),
1887 blocksize, generation);
1888 if (!tree_root->node)
1889 goto fail_chunk_root;
1890 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1891 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1892 sb->s_id);
1893 goto fail_tree_root;
1894 }
1895 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1896 tree_root->commit_root = btrfs_root_node(tree_root);
1897
1898 ret = find_and_setup_root(tree_root, fs_info,
1899 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1900 if (ret)
1901 goto fail_tree_root;
1902 extent_root->track_dirty = 1;
1903
1904 ret = find_and_setup_root(tree_root, fs_info,
1905 BTRFS_DEV_TREE_OBJECTID, dev_root);
1906 if (ret)
1907 goto fail_extent_root;
1908 dev_root->track_dirty = 1;
1909
1910 ret = find_and_setup_root(tree_root, fs_info,
1911 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1912 if (ret)
1913 goto fail_dev_root;
1914
1915 csum_root->track_dirty = 1;
1916
1917 ret = btrfs_read_block_groups(extent_root);
1918 if (ret) {
1919 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1920 goto fail_block_groups;
1921 }
1922
1923 fs_info->generation = generation;
1924 fs_info->last_trans_committed = generation;
1925 fs_info->data_alloc_profile = (u64)-1;
1926 fs_info->metadata_alloc_profile = (u64)-1;
1927 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1928 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1929 "btrfs-cleaner");
1930 if (IS_ERR(fs_info->cleaner_kthread))
1931 goto fail_block_groups;
1932
1933 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1934 tree_root,
1935 "btrfs-transaction");
1936 if (IS_ERR(fs_info->transaction_kthread))
1937 goto fail_cleaner;
1938
1939 if (!btrfs_test_opt(tree_root, SSD) &&
1940 !btrfs_test_opt(tree_root, NOSSD) &&
1941 !fs_info->fs_devices->rotating) {
1942 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1943 "mode\n");
1944 btrfs_set_opt(fs_info->mount_opt, SSD);
1945 }
1946
1947 if (btrfs_super_log_root(disk_super) != 0) {
1948 u64 bytenr = btrfs_super_log_root(disk_super);
1949
1950 if (fs_devices->rw_devices == 0) {
1951 printk(KERN_WARNING "Btrfs log replay required "
1952 "on RO media\n");
1953 err = -EIO;
1954 goto fail_trans_kthread;
1955 }
1956 blocksize =
1957 btrfs_level_size(tree_root,
1958 btrfs_super_log_root_level(disk_super));
1959
1960 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1961 GFP_NOFS);
1962
1963 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1964 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1965
1966 log_tree_root->node = read_tree_block(tree_root, bytenr,
1967 blocksize,
1968 generation + 1);
1969 ret = btrfs_recover_log_trees(log_tree_root);
1970 BUG_ON(ret);
1971
1972 if (sb->s_flags & MS_RDONLY) {
1973 ret = btrfs_commit_super(tree_root);
1974 BUG_ON(ret);
1975 }
1976 }
1977
1978 ret = btrfs_find_orphan_roots(tree_root);
1979 BUG_ON(ret);
1980
1981 if (!(sb->s_flags & MS_RDONLY)) {
1982 ret = btrfs_recover_relocation(tree_root);
1983 if (ret < 0) {
1984 printk(KERN_WARNING
1985 "btrfs: failed to recover relocation\n");
1986 err = -EINVAL;
1987 goto fail_trans_kthread;
1988 }
1989 }
1990
1991 location.objectid = BTRFS_FS_TREE_OBJECTID;
1992 location.type = BTRFS_ROOT_ITEM_KEY;
1993 location.offset = (u64)-1;
1994
1995 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1996 if (!fs_info->fs_root)
1997 goto fail_trans_kthread;
1998
1999 if (!(sb->s_flags & MS_RDONLY)) {
2000 down_read(&fs_info->cleanup_work_sem);
2001 btrfs_orphan_cleanup(fs_info->fs_root);
2002 up_read(&fs_info->cleanup_work_sem);
2003 }
2004
2005 return tree_root;
2006
2007 fail_trans_kthread:
2008 kthread_stop(fs_info->transaction_kthread);
2009 fail_cleaner:
2010 kthread_stop(fs_info->cleaner_kthread);
2011
2012 /*
2013 * make sure we're done with the btree inode before we stop our
2014 * kthreads
2015 */
2016 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2017 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2018
2019 fail_block_groups:
2020 btrfs_free_block_groups(fs_info);
2021 free_extent_buffer(csum_root->node);
2022 free_extent_buffer(csum_root->commit_root);
2023 fail_dev_root:
2024 free_extent_buffer(dev_root->node);
2025 free_extent_buffer(dev_root->commit_root);
2026 fail_extent_root:
2027 free_extent_buffer(extent_root->node);
2028 free_extent_buffer(extent_root->commit_root);
2029 fail_tree_root:
2030 free_extent_buffer(tree_root->node);
2031 free_extent_buffer(tree_root->commit_root);
2032 fail_chunk_root:
2033 free_extent_buffer(chunk_root->node);
2034 free_extent_buffer(chunk_root->commit_root);
2035 fail_sb_buffer:
2036 btrfs_stop_workers(&fs_info->generic_worker);
2037 btrfs_stop_workers(&fs_info->fixup_workers);
2038 btrfs_stop_workers(&fs_info->delalloc_workers);
2039 btrfs_stop_workers(&fs_info->workers);
2040 btrfs_stop_workers(&fs_info->endio_workers);
2041 btrfs_stop_workers(&fs_info->endio_meta_workers);
2042 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2043 btrfs_stop_workers(&fs_info->endio_write_workers);
2044 btrfs_stop_workers(&fs_info->submit_workers);
2045 btrfs_stop_workers(&fs_info->enospc_workers);
2046 fail_iput:
2047 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2048 iput(fs_info->btree_inode);
2049
2050 btrfs_close_devices(fs_info->fs_devices);
2051 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2052 fail_bdi:
2053 bdi_destroy(&fs_info->bdi);
2054 fail_srcu:
2055 cleanup_srcu_struct(&fs_info->subvol_srcu);
2056 fail:
2057 kfree(extent_root);
2058 kfree(tree_root);
2059 kfree(fs_info);
2060 kfree(chunk_root);
2061 kfree(dev_root);
2062 kfree(csum_root);
2063 return ERR_PTR(err);
2064 }
2065
2066 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2067 {
2068 char b[BDEVNAME_SIZE];
2069
2070 if (uptodate) {
2071 set_buffer_uptodate(bh);
2072 } else {
2073 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
2074 printk(KERN_WARNING "lost page write due to "
2075 "I/O error on %s\n",
2076 bdevname(bh->b_bdev, b));
2077 }
2078 /* note, we dont' set_buffer_write_io_error because we have
2079 * our own ways of dealing with the IO errors
2080 */
2081 clear_buffer_uptodate(bh);
2082 }
2083 unlock_buffer(bh);
2084 put_bh(bh);
2085 }
2086
2087 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2088 {
2089 struct buffer_head *bh;
2090 struct buffer_head *latest = NULL;
2091 struct btrfs_super_block *super;
2092 int i;
2093 u64 transid = 0;
2094 u64 bytenr;
2095
2096 /* we would like to check all the supers, but that would make
2097 * a btrfs mount succeed after a mkfs from a different FS.
2098 * So, we need to add a special mount option to scan for
2099 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2100 */
2101 for (i = 0; i < 1; i++) {
2102 bytenr = btrfs_sb_offset(i);
2103 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2104 break;
2105 bh = __bread(bdev, bytenr / 4096, 4096);
2106 if (!bh)
2107 continue;
2108
2109 super = (struct btrfs_super_block *)bh->b_data;
2110 if (btrfs_super_bytenr(super) != bytenr ||
2111 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2112 sizeof(super->magic))) {
2113 brelse(bh);
2114 continue;
2115 }
2116
2117 if (!latest || btrfs_super_generation(super) > transid) {
2118 brelse(latest);
2119 latest = bh;
2120 transid = btrfs_super_generation(super);
2121 } else {
2122 brelse(bh);
2123 }
2124 }
2125 return latest;
2126 }
2127
2128 /*
2129 * this should be called twice, once with wait == 0 and
2130 * once with wait == 1. When wait == 0 is done, all the buffer heads
2131 * we write are pinned.
2132 *
2133 * They are released when wait == 1 is done.
2134 * max_mirrors must be the same for both runs, and it indicates how
2135 * many supers on this one device should be written.
2136 *
2137 * max_mirrors == 0 means to write them all.
2138 */
2139 static int write_dev_supers(struct btrfs_device *device,
2140 struct btrfs_super_block *sb,
2141 int do_barriers, int wait, int max_mirrors)
2142 {
2143 struct buffer_head *bh;
2144 int i;
2145 int ret;
2146 int errors = 0;
2147 u32 crc;
2148 u64 bytenr;
2149 int last_barrier = 0;
2150
2151 if (max_mirrors == 0)
2152 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2153
2154 /* make sure only the last submit_bh does a barrier */
2155 if (do_barriers) {
2156 for (i = 0; i < max_mirrors; i++) {
2157 bytenr = btrfs_sb_offset(i);
2158 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2159 device->total_bytes)
2160 break;
2161 last_barrier = i;
2162 }
2163 }
2164
2165 for (i = 0; i < max_mirrors; i++) {
2166 bytenr = btrfs_sb_offset(i);
2167 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2168 break;
2169
2170 if (wait) {
2171 bh = __find_get_block(device->bdev, bytenr / 4096,
2172 BTRFS_SUPER_INFO_SIZE);
2173 BUG_ON(!bh);
2174 wait_on_buffer(bh);
2175 if (!buffer_uptodate(bh))
2176 errors++;
2177
2178 /* drop our reference */
2179 brelse(bh);
2180
2181 /* drop the reference from the wait == 0 run */
2182 brelse(bh);
2183 continue;
2184 } else {
2185 btrfs_set_super_bytenr(sb, bytenr);
2186
2187 crc = ~(u32)0;
2188 crc = btrfs_csum_data(NULL, (char *)sb +
2189 BTRFS_CSUM_SIZE, crc,
2190 BTRFS_SUPER_INFO_SIZE -
2191 BTRFS_CSUM_SIZE);
2192 btrfs_csum_final(crc, sb->csum);
2193
2194 /*
2195 * one reference for us, and we leave it for the
2196 * caller
2197 */
2198 bh = __getblk(device->bdev, bytenr / 4096,
2199 BTRFS_SUPER_INFO_SIZE);
2200 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2201
2202 /* one reference for submit_bh */
2203 get_bh(bh);
2204
2205 set_buffer_uptodate(bh);
2206 lock_buffer(bh);
2207 bh->b_end_io = btrfs_end_buffer_write_sync;
2208 }
2209
2210 if (i == last_barrier && do_barriers && device->barriers) {
2211 ret = submit_bh(WRITE_BARRIER, bh);
2212 if (ret == -EOPNOTSUPP) {
2213 printk("btrfs: disabling barriers on dev %s\n",
2214 device->name);
2215 set_buffer_uptodate(bh);
2216 device->barriers = 0;
2217 /* one reference for submit_bh */
2218 get_bh(bh);
2219 lock_buffer(bh);
2220 ret = submit_bh(WRITE_SYNC, bh);
2221 }
2222 } else {
2223 ret = submit_bh(WRITE_SYNC, bh);
2224 }
2225
2226 if (ret)
2227 errors++;
2228 }
2229 return errors < i ? 0 : -1;
2230 }
2231
2232 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2233 {
2234 struct list_head *head;
2235 struct btrfs_device *dev;
2236 struct btrfs_super_block *sb;
2237 struct btrfs_dev_item *dev_item;
2238 int ret;
2239 int do_barriers;
2240 int max_errors;
2241 int total_errors = 0;
2242 u64 flags;
2243
2244 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2245 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2246
2247 sb = &root->fs_info->super_for_commit;
2248 dev_item = &sb->dev_item;
2249
2250 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2251 head = &root->fs_info->fs_devices->devices;
2252 list_for_each_entry(dev, head, dev_list) {
2253 if (!dev->bdev) {
2254 total_errors++;
2255 continue;
2256 }
2257 if (!dev->in_fs_metadata || !dev->writeable)
2258 continue;
2259
2260 btrfs_set_stack_device_generation(dev_item, 0);
2261 btrfs_set_stack_device_type(dev_item, dev->type);
2262 btrfs_set_stack_device_id(dev_item, dev->devid);
2263 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2264 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2265 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2266 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2267 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2268 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2269 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2270
2271 flags = btrfs_super_flags(sb);
2272 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2273
2274 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2275 if (ret)
2276 total_errors++;
2277 }
2278 if (total_errors > max_errors) {
2279 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2280 total_errors);
2281 BUG();
2282 }
2283
2284 total_errors = 0;
2285 list_for_each_entry(dev, head, dev_list) {
2286 if (!dev->bdev)
2287 continue;
2288 if (!dev->in_fs_metadata || !dev->writeable)
2289 continue;
2290
2291 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2292 if (ret)
2293 total_errors++;
2294 }
2295 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2296 if (total_errors > max_errors) {
2297 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2298 total_errors);
2299 BUG();
2300 }
2301 return 0;
2302 }
2303
2304 int write_ctree_super(struct btrfs_trans_handle *trans,
2305 struct btrfs_root *root, int max_mirrors)
2306 {
2307 int ret;
2308
2309 ret = write_all_supers(root, max_mirrors);
2310 return ret;
2311 }
2312
2313 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2314 {
2315 spin_lock(&fs_info->fs_roots_radix_lock);
2316 radix_tree_delete(&fs_info->fs_roots_radix,
2317 (unsigned long)root->root_key.objectid);
2318 spin_unlock(&fs_info->fs_roots_radix_lock);
2319
2320 if (btrfs_root_refs(&root->root_item) == 0)
2321 synchronize_srcu(&fs_info->subvol_srcu);
2322
2323 free_fs_root(root);
2324 return 0;
2325 }
2326
2327 static void free_fs_root(struct btrfs_root *root)
2328 {
2329 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2330 if (root->anon_super.s_dev) {
2331 down_write(&root->anon_super.s_umount);
2332 kill_anon_super(&root->anon_super);
2333 }
2334 free_extent_buffer(root->node);
2335 free_extent_buffer(root->commit_root);
2336 kfree(root->name);
2337 kfree(root);
2338 }
2339
2340 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2341 {
2342 int ret;
2343 struct btrfs_root *gang[8];
2344 int i;
2345
2346 while (!list_empty(&fs_info->dead_roots)) {
2347 gang[0] = list_entry(fs_info->dead_roots.next,
2348 struct btrfs_root, root_list);
2349 list_del(&gang[0]->root_list);
2350
2351 if (gang[0]->in_radix) {
2352 btrfs_free_fs_root(fs_info, gang[0]);
2353 } else {
2354 free_extent_buffer(gang[0]->node);
2355 free_extent_buffer(gang[0]->commit_root);
2356 kfree(gang[0]);
2357 }
2358 }
2359
2360 while (1) {
2361 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2362 (void **)gang, 0,
2363 ARRAY_SIZE(gang));
2364 if (!ret)
2365 break;
2366 for (i = 0; i < ret; i++)
2367 btrfs_free_fs_root(fs_info, gang[i]);
2368 }
2369 return 0;
2370 }
2371
2372 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2373 {
2374 u64 root_objectid = 0;
2375 struct btrfs_root *gang[8];
2376 int i;
2377 int ret;
2378
2379 while (1) {
2380 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2381 (void **)gang, root_objectid,
2382 ARRAY_SIZE(gang));
2383 if (!ret)
2384 break;
2385
2386 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2387 for (i = 0; i < ret; i++) {
2388 root_objectid = gang[i]->root_key.objectid;
2389 btrfs_orphan_cleanup(gang[i]);
2390 }
2391 root_objectid++;
2392 }
2393 return 0;
2394 }
2395
2396 int btrfs_commit_super(struct btrfs_root *root)
2397 {
2398 struct btrfs_trans_handle *trans;
2399 int ret;
2400
2401 mutex_lock(&root->fs_info->cleaner_mutex);
2402 btrfs_run_delayed_iputs(root);
2403 btrfs_clean_old_snapshots(root);
2404 mutex_unlock(&root->fs_info->cleaner_mutex);
2405
2406 /* wait until ongoing cleanup work done */
2407 down_write(&root->fs_info->cleanup_work_sem);
2408 up_write(&root->fs_info->cleanup_work_sem);
2409
2410 trans = btrfs_start_transaction(root, 1);
2411 ret = btrfs_commit_transaction(trans, root);
2412 BUG_ON(ret);
2413 /* run commit again to drop the original snapshot */
2414 trans = btrfs_start_transaction(root, 1);
2415 btrfs_commit_transaction(trans, root);
2416 ret = btrfs_write_and_wait_transaction(NULL, root);
2417 BUG_ON(ret);
2418
2419 ret = write_ctree_super(NULL, root, 0);
2420 return ret;
2421 }
2422
2423 int close_ctree(struct btrfs_root *root)
2424 {
2425 struct btrfs_fs_info *fs_info = root->fs_info;
2426 int ret;
2427
2428 fs_info->closing = 1;
2429 smp_mb();
2430
2431 kthread_stop(root->fs_info->transaction_kthread);
2432 kthread_stop(root->fs_info->cleaner_kthread);
2433
2434 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2435 ret = btrfs_commit_super(root);
2436 if (ret)
2437 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2438 }
2439
2440 fs_info->closing = 2;
2441 smp_mb();
2442
2443 if (fs_info->delalloc_bytes) {
2444 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2445 (unsigned long long)fs_info->delalloc_bytes);
2446 }
2447 if (fs_info->total_ref_cache_size) {
2448 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2449 (unsigned long long)fs_info->total_ref_cache_size);
2450 }
2451
2452 free_extent_buffer(fs_info->extent_root->node);
2453 free_extent_buffer(fs_info->extent_root->commit_root);
2454 free_extent_buffer(fs_info->tree_root->node);
2455 free_extent_buffer(fs_info->tree_root->commit_root);
2456 free_extent_buffer(root->fs_info->chunk_root->node);
2457 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2458 free_extent_buffer(root->fs_info->dev_root->node);
2459 free_extent_buffer(root->fs_info->dev_root->commit_root);
2460 free_extent_buffer(root->fs_info->csum_root->node);
2461 free_extent_buffer(root->fs_info->csum_root->commit_root);
2462
2463 btrfs_free_block_groups(root->fs_info);
2464
2465 del_fs_roots(fs_info);
2466
2467 iput(fs_info->btree_inode);
2468
2469 btrfs_stop_workers(&fs_info->generic_worker);
2470 btrfs_stop_workers(&fs_info->fixup_workers);
2471 btrfs_stop_workers(&fs_info->delalloc_workers);
2472 btrfs_stop_workers(&fs_info->workers);
2473 btrfs_stop_workers(&fs_info->endio_workers);
2474 btrfs_stop_workers(&fs_info->endio_meta_workers);
2475 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2476 btrfs_stop_workers(&fs_info->endio_write_workers);
2477 btrfs_stop_workers(&fs_info->submit_workers);
2478 btrfs_stop_workers(&fs_info->enospc_workers);
2479
2480 btrfs_close_devices(fs_info->fs_devices);
2481 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2482
2483 bdi_destroy(&fs_info->bdi);
2484 cleanup_srcu_struct(&fs_info->subvol_srcu);
2485
2486 kfree(fs_info->extent_root);
2487 kfree(fs_info->tree_root);
2488 kfree(fs_info->chunk_root);
2489 kfree(fs_info->dev_root);
2490 kfree(fs_info->csum_root);
2491 return 0;
2492 }
2493
2494 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2495 {
2496 int ret;
2497 struct inode *btree_inode = buf->first_page->mapping->host;
2498
2499 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2500 NULL);
2501 if (!ret)
2502 return ret;
2503
2504 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2505 parent_transid);
2506 return !ret;
2507 }
2508
2509 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2510 {
2511 struct inode *btree_inode = buf->first_page->mapping->host;
2512 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2513 buf);
2514 }
2515
2516 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2517 {
2518 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2519 u64 transid = btrfs_header_generation(buf);
2520 struct inode *btree_inode = root->fs_info->btree_inode;
2521 int was_dirty;
2522
2523 btrfs_assert_tree_locked(buf);
2524 if (transid != root->fs_info->generation) {
2525 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2526 "found %llu running %llu\n",
2527 (unsigned long long)buf->start,
2528 (unsigned long long)transid,
2529 (unsigned long long)root->fs_info->generation);
2530 WARN_ON(1);
2531 }
2532 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2533 buf);
2534 if (!was_dirty) {
2535 spin_lock(&root->fs_info->delalloc_lock);
2536 root->fs_info->dirty_metadata_bytes += buf->len;
2537 spin_unlock(&root->fs_info->delalloc_lock);
2538 }
2539 }
2540
2541 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2542 {
2543 /*
2544 * looks as though older kernels can get into trouble with
2545 * this code, they end up stuck in balance_dirty_pages forever
2546 */
2547 u64 num_dirty;
2548 unsigned long thresh = 32 * 1024 * 1024;
2549
2550 if (current->flags & PF_MEMALLOC)
2551 return;
2552
2553 num_dirty = root->fs_info->dirty_metadata_bytes;
2554
2555 if (num_dirty > thresh) {
2556 balance_dirty_pages_ratelimited_nr(
2557 root->fs_info->btree_inode->i_mapping, 1);
2558 }
2559 return;
2560 }
2561
2562 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2563 {
2564 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2565 int ret;
2566 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2567 if (ret == 0)
2568 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2569 return ret;
2570 }
2571
2572 int btree_lock_page_hook(struct page *page)
2573 {
2574 struct inode *inode = page->mapping->host;
2575 struct btrfs_root *root = BTRFS_I(inode)->root;
2576 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2577 struct extent_buffer *eb;
2578 unsigned long len;
2579 u64 bytenr = page_offset(page);
2580
2581 if (page->private == EXTENT_PAGE_PRIVATE)
2582 goto out;
2583
2584 len = page->private >> 2;
2585 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2586 if (!eb)
2587 goto out;
2588
2589 btrfs_tree_lock(eb);
2590 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2591
2592 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2593 spin_lock(&root->fs_info->delalloc_lock);
2594 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2595 root->fs_info->dirty_metadata_bytes -= eb->len;
2596 else
2597 WARN_ON(1);
2598 spin_unlock(&root->fs_info->delalloc_lock);
2599 }
2600
2601 btrfs_tree_unlock(eb);
2602 free_extent_buffer(eb);
2603 out:
2604 lock_page(page);
2605 return 0;
2606 }
2607
2608 static struct extent_io_ops btree_extent_io_ops = {
2609 .write_cache_pages_lock_hook = btree_lock_page_hook,
2610 .readpage_end_io_hook = btree_readpage_end_io_hook,
2611 .submit_bio_hook = btree_submit_bio_hook,
2612 /* note we're sharing with inode.c for the merge bio hook */
2613 .merge_bio_hook = btrfs_merge_bio_hook,
2614 };
Linux ARM platform port for MOXA ART SoC