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USB: mxc: gadget: remove 60mhz clock requirement for freescale mx51 usb core
[linux-2.6.git] / fs / btrfs / disk-io.c
blobfeca04197d028e9d25a73dd177299319e1af351d
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
1152 return root;
1153 }
1154
1155 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1156 u64 root_objectid)
1157 {
1158 struct btrfs_root *root;
1159
1160 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1161 return fs_info->tree_root;
1162 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1163 return fs_info->extent_root;
1164
1165 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1166 (unsigned long)root_objectid);
1167 return root;
1168 }
1169
1170 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1171 struct btrfs_key *location)
1172 {
1173 struct btrfs_root *root;
1174 int ret;
1175
1176 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1177 return fs_info->tree_root;
1178 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1179 return fs_info->extent_root;
1180 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1181 return fs_info->chunk_root;
1182 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1183 return fs_info->dev_root;
1184 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1185 return fs_info->csum_root;
1186 again:
1187 spin_lock(&fs_info->fs_roots_radix_lock);
1188 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1189 (unsigned long)location->objectid);
1190 spin_unlock(&fs_info->fs_roots_radix_lock);
1191 if (root)
1192 return root;
1193
1194 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1195 if (ret == 0)
1196 ret = -ENOENT;
1197 if (ret < 0)
1198 return ERR_PTR(ret);
1199
1200 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1201 if (IS_ERR(root))
1202 return root;
1203
1204 WARN_ON(btrfs_root_refs(&root->root_item) == 0);
1205 set_anon_super(&root->anon_super, NULL);
1206
1207 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1208 if (ret)
1209 goto fail;
1210
1211 spin_lock(&fs_info->fs_roots_radix_lock);
1212 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1213 (unsigned long)root->root_key.objectid,
1214 root);
1215 if (ret == 0) {
1216 root->in_radix = 1;
1217 root->clean_orphans = 1;
1218 }
1219 spin_unlock(&fs_info->fs_roots_radix_lock);
1220 radix_tree_preload_end();
1221 if (ret) {
1222 if (ret == -EEXIST) {
1223 free_fs_root(root);
1224 goto again;
1225 }
1226 goto fail;
1227 }
1228
1229 ret = btrfs_find_dead_roots(fs_info->tree_root,
1230 root->root_key.objectid);
1231 WARN_ON(ret);
1232 return root;
1233 fail:
1234 free_fs_root(root);
1235 return ERR_PTR(ret);
1236 }
1237
1238 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1239 struct btrfs_key *location,
1240 const char *name, int namelen)
1241 {
1242 return btrfs_read_fs_root_no_name(fs_info, location);
1243 #if 0
1244 struct btrfs_root *root;
1245 int ret;
1246
1247 root = btrfs_read_fs_root_no_name(fs_info, location);
1248 if (!root)
1249 return NULL;
1250
1251 if (root->in_sysfs)
1252 return root;
1253
1254 ret = btrfs_set_root_name(root, name, namelen);
1255 if (ret) {
1256 free_extent_buffer(root->node);
1257 kfree(root);
1258 return ERR_PTR(ret);
1259 }
1260
1261 ret = btrfs_sysfs_add_root(root);
1262 if (ret) {
1263 free_extent_buffer(root->node);
1264 kfree(root->name);
1265 kfree(root);
1266 return ERR_PTR(ret);
1267 }
1268 root->in_sysfs = 1;
1269 return root;
1270 #endif
1271 }
1272
1273 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1274 {
1275 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1276 int ret = 0;
1277 struct btrfs_device *device;
1278 struct backing_dev_info *bdi;
1279
1280 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1281 if (!device->bdev)
1282 continue;
1283 bdi = blk_get_backing_dev_info(device->bdev);
1284 if (bdi && bdi_congested(bdi, bdi_bits)) {
1285 ret = 1;
1286 break;
1287 }
1288 }
1289 return ret;
1290 }
1291
1292 /*
1293 * this unplugs every device on the box, and it is only used when page
1294 * is null
1295 */
1296 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1297 {
1298 struct btrfs_device *device;
1299 struct btrfs_fs_info *info;
1300
1301 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1302 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1303 if (!device->bdev)
1304 continue;
1305
1306 bdi = blk_get_backing_dev_info(device->bdev);
1307 if (bdi->unplug_io_fn)
1308 bdi->unplug_io_fn(bdi, page);
1309 }
1310 }
1311
1312 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1313 {
1314 struct inode *inode;
1315 struct extent_map_tree *em_tree;
1316 struct extent_map *em;
1317 struct address_space *mapping;
1318 u64 offset;
1319
1320 /* the generic O_DIRECT read code does this */
1321 if (1 || !page) {
1322 __unplug_io_fn(bdi, page);
1323 return;
1324 }
1325
1326 /*
1327 * page->mapping may change at any time. Get a consistent copy
1328 * and use that for everything below
1329 */
1330 smp_mb();
1331 mapping = page->mapping;
1332 if (!mapping)
1333 return;
1334
1335 inode = mapping->host;
1336
1337 /*
1338 * don't do the expensive searching for a small number of
1339 * devices
1340 */
1341 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1342 __unplug_io_fn(bdi, page);
1343 return;
1344 }
1345
1346 offset = page_offset(page);
1347
1348 em_tree = &BTRFS_I(inode)->extent_tree;
1349 read_lock(&em_tree->lock);
1350 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1351 read_unlock(&em_tree->lock);
1352 if (!em) {
1353 __unplug_io_fn(bdi, page);
1354 return;
1355 }
1356
1357 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1358 free_extent_map(em);
1359 __unplug_io_fn(bdi, page);
1360 return;
1361 }
1362 offset = offset - em->start;
1363 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1364 em->block_start + offset, page);
1365 free_extent_map(em);
1366 }
1367
1368 /*
1369 * If this fails, caller must call bdi_destroy() to get rid of the
1370 * bdi again.
1371 */
1372 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1373 {
1374 int err;
1375
1376 bdi->capabilities = BDI_CAP_MAP_COPY;
1377 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1378 if (err)
1379 return err;
1380
1381 bdi->ra_pages = default_backing_dev_info.ra_pages;
1382 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1383 bdi->unplug_io_data = info;
1384 bdi->congested_fn = btrfs_congested_fn;
1385 bdi->congested_data = info;
1386 return 0;
1387 }
1388
1389 static int bio_ready_for_csum(struct bio *bio)
1390 {
1391 u64 length = 0;
1392 u64 buf_len = 0;
1393 u64 start = 0;
1394 struct page *page;
1395 struct extent_io_tree *io_tree = NULL;
1396 struct btrfs_fs_info *info = NULL;
1397 struct bio_vec *bvec;
1398 int i;
1399 int ret;
1400
1401 bio_for_each_segment(bvec, bio, i) {
1402 page = bvec->bv_page;
1403 if (page->private == EXTENT_PAGE_PRIVATE) {
1404 length += bvec->bv_len;
1405 continue;
1406 }
1407 if (!page->private) {
1408 length += bvec->bv_len;
1409 continue;
1410 }
1411 length = bvec->bv_len;
1412 buf_len = page->private >> 2;
1413 start = page_offset(page) + bvec->bv_offset;
1414 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1415 info = BTRFS_I(page->mapping->host)->root->fs_info;
1416 }
1417 /* are we fully contained in this bio? */
1418 if (buf_len <= length)
1419 return 1;
1420
1421 ret = extent_range_uptodate(io_tree, start + length,
1422 start + buf_len - 1);
1423 return ret;
1424 }
1425
1426 /*
1427 * called by the kthread helper functions to finally call the bio end_io
1428 * functions. This is where read checksum verification actually happens
1429 */
1430 static void end_workqueue_fn(struct btrfs_work *work)
1431 {
1432 struct bio *bio;
1433 struct end_io_wq *end_io_wq;
1434 struct btrfs_fs_info *fs_info;
1435 int error;
1436
1437 end_io_wq = container_of(work, struct end_io_wq, work);
1438 bio = end_io_wq->bio;
1439 fs_info = end_io_wq->info;
1440
1441 /* metadata bio reads are special because the whole tree block must
1442 * be checksummed at once. This makes sure the entire block is in
1443 * ram and up to date before trying to verify things. For
1444 * blocksize <= pagesize, it is basically a noop
1445 */
1446 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1447 !bio_ready_for_csum(bio)) {
1448 btrfs_queue_worker(&fs_info->endio_meta_workers,
1449 &end_io_wq->work);
1450 return;
1451 }
1452 error = end_io_wq->error;
1453 bio->bi_private = end_io_wq->private;
1454 bio->bi_end_io = end_io_wq->end_io;
1455 kfree(end_io_wq);
1456 bio_endio(bio, error);
1457 }
1458
1459 static int cleaner_kthread(void *arg)
1460 {
1461 struct btrfs_root *root = arg;
1462
1463 do {
1464 smp_mb();
1465 if (root->fs_info->closing)
1466 break;
1467
1468 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1469
1470 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1471 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1472 btrfs_run_delayed_iputs(root);
1473 btrfs_clean_old_snapshots(root);
1474 mutex_unlock(&root->fs_info->cleaner_mutex);
1475 }
1476
1477 if (freezing(current)) {
1478 refrigerator();
1479 } else {
1480 smp_mb();
1481 if (root->fs_info->closing)
1482 break;
1483 set_current_state(TASK_INTERRUPTIBLE);
1484 schedule();
1485 __set_current_state(TASK_RUNNING);
1486 }
1487 } while (!kthread_should_stop());
1488 return 0;
1489 }
1490
1491 static int transaction_kthread(void *arg)
1492 {
1493 struct btrfs_root *root = arg;
1494 struct btrfs_trans_handle *trans;
1495 struct btrfs_transaction *cur;
1496 unsigned long now;
1497 unsigned long delay;
1498 int ret;
1499
1500 do {
1501 smp_mb();
1502 if (root->fs_info->closing)
1503 break;
1504
1505 delay = HZ * 30;
1506 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1507 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1508
1509 mutex_lock(&root->fs_info->trans_mutex);
1510 cur = root->fs_info->running_transaction;
1511 if (!cur) {
1512 mutex_unlock(&root->fs_info->trans_mutex);
1513 goto sleep;
1514 }
1515
1516 now = get_seconds();
1517 if (now < cur->start_time || now - cur->start_time < 30) {
1518 mutex_unlock(&root->fs_info->trans_mutex);
1519 delay = HZ * 5;
1520 goto sleep;
1521 }
1522 mutex_unlock(&root->fs_info->trans_mutex);
1523 trans = btrfs_start_transaction(root, 1);
1524 ret = btrfs_commit_transaction(trans, root);
1525
1526 sleep:
1527 wake_up_process(root->fs_info->cleaner_kthread);
1528 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1529
1530 if (freezing(current)) {
1531 refrigerator();
1532 } else {
1533 if (root->fs_info->closing)
1534 break;
1535 set_current_state(TASK_INTERRUPTIBLE);
1536 schedule_timeout(delay);
1537 __set_current_state(TASK_RUNNING);
1538 }
1539 } while (!kthread_should_stop());
1540 return 0;
1541 }
1542
1543 struct btrfs_root *open_ctree(struct super_block *sb,
1544 struct btrfs_fs_devices *fs_devices,
1545 char *options)
1546 {
1547 u32 sectorsize;
1548 u32 nodesize;
1549 u32 leafsize;
1550 u32 blocksize;
1551 u32 stripesize;
1552 u64 generation;
1553 u64 features;
1554 struct btrfs_key location;
1555 struct buffer_head *bh;
1556 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1557 GFP_NOFS);
1558 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1559 GFP_NOFS);
1560 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1561 GFP_NOFS);
1562 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1563 GFP_NOFS);
1564 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1565 GFP_NOFS);
1566 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1567 GFP_NOFS);
1568 struct btrfs_root *log_tree_root;
1569
1570 int ret;
1571 int err = -EINVAL;
1572
1573 struct btrfs_super_block *disk_super;
1574
1575 if (!extent_root || !tree_root || !fs_info ||
1576 !chunk_root || !dev_root || !csum_root) {
1577 err = -ENOMEM;
1578 goto fail;
1579 }
1580
1581 ret = init_srcu_struct(&fs_info->subvol_srcu);
1582 if (ret) {
1583 err = ret;
1584 goto fail;
1585 }
1586
1587 ret = setup_bdi(fs_info, &fs_info->bdi);
1588 if (ret) {
1589 err = ret;
1590 goto fail_srcu;
1591 }
1592
1593 fs_info->btree_inode = new_inode(sb);
1594 if (!fs_info->btree_inode) {
1595 err = -ENOMEM;
1596 goto fail_bdi;
1597 }
1598
1599 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1600 INIT_LIST_HEAD(&fs_info->trans_list);
1601 INIT_LIST_HEAD(&fs_info->dead_roots);
1602 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1603 INIT_LIST_HEAD(&fs_info->hashers);
1604 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1605 INIT_LIST_HEAD(&fs_info->ordered_operations);
1606 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1607 spin_lock_init(&fs_info->delalloc_lock);
1608 spin_lock_init(&fs_info->new_trans_lock);
1609 spin_lock_init(&fs_info->ref_cache_lock);
1610 spin_lock_init(&fs_info->fs_roots_radix_lock);
1611 spin_lock_init(&fs_info->delayed_iput_lock);
1612
1613 init_completion(&fs_info->kobj_unregister);
1614 fs_info->tree_root = tree_root;
1615 fs_info->extent_root = extent_root;
1616 fs_info->csum_root = csum_root;
1617 fs_info->chunk_root = chunk_root;
1618 fs_info->dev_root = dev_root;
1619 fs_info->fs_devices = fs_devices;
1620 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1621 INIT_LIST_HEAD(&fs_info->space_info);
1622 btrfs_mapping_init(&fs_info->mapping_tree);
1623 atomic_set(&fs_info->nr_async_submits, 0);
1624 atomic_set(&fs_info->async_delalloc_pages, 0);
1625 atomic_set(&fs_info->async_submit_draining, 0);
1626 atomic_set(&fs_info->nr_async_bios, 0);
1627 fs_info->sb = sb;
1628 fs_info->max_inline = 8192 * 1024;
1629 fs_info->metadata_ratio = 0;
1630
1631 fs_info->thread_pool_size = min_t(unsigned long,
1632 num_online_cpus() + 2, 8);
1633
1634 INIT_LIST_HEAD(&fs_info->ordered_extents);
1635 spin_lock_init(&fs_info->ordered_extent_lock);
1636
1637 sb->s_blocksize = 4096;
1638 sb->s_blocksize_bits = blksize_bits(4096);
1639 sb->s_bdi = &fs_info->bdi;
1640
1641 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1642 fs_info->btree_inode->i_nlink = 1;
1643 /*
1644 * we set the i_size on the btree inode to the max possible int.
1645 * the real end of the address space is determined by all of
1646 * the devices in the system
1647 */
1648 fs_info->btree_inode->i_size = OFFSET_MAX;
1649 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1650 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1651
1652 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1653 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1654 fs_info->btree_inode->i_mapping,
1655 GFP_NOFS);
1656 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1657 GFP_NOFS);
1658
1659 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1660
1661 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1662 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1663 sizeof(struct btrfs_key));
1664 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1665 insert_inode_hash(fs_info->btree_inode);
1666
1667 spin_lock_init(&fs_info->block_group_cache_lock);
1668 fs_info->block_group_cache_tree = RB_ROOT;
1669
1670 extent_io_tree_init(&fs_info->freed_extents[0],
1671 fs_info->btree_inode->i_mapping, GFP_NOFS);
1672 extent_io_tree_init(&fs_info->freed_extents[1],
1673 fs_info->btree_inode->i_mapping, GFP_NOFS);
1674 fs_info->pinned_extents = &fs_info->freed_extents[0];
1675 fs_info->do_barriers = 1;
1676
1677
1678 mutex_init(&fs_info->trans_mutex);
1679 mutex_init(&fs_info->ordered_operations_mutex);
1680 mutex_init(&fs_info->tree_log_mutex);
1681 mutex_init(&fs_info->chunk_mutex);
1682 mutex_init(&fs_info->transaction_kthread_mutex);
1683 mutex_init(&fs_info->cleaner_mutex);
1684 mutex_init(&fs_info->volume_mutex);
1685 init_rwsem(&fs_info->extent_commit_sem);
1686 init_rwsem(&fs_info->cleanup_work_sem);
1687 init_rwsem(&fs_info->subvol_sem);
1688
1689 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1690 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1691
1692 init_waitqueue_head(&fs_info->transaction_throttle);
1693 init_waitqueue_head(&fs_info->transaction_wait);
1694 init_waitqueue_head(&fs_info->async_submit_wait);
1695
1696 __setup_root(4096, 4096, 4096, 4096, tree_root,
1697 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1698
1699
1700 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1701 if (!bh)
1702 goto fail_iput;
1703
1704 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1705 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1706 sizeof(fs_info->super_for_commit));
1707 brelse(bh);
1708
1709 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1710
1711 disk_super = &fs_info->super_copy;
1712 if (!btrfs_super_root(disk_super))
1713 goto fail_iput;
1714
1715 ret = btrfs_parse_options(tree_root, options);
1716 if (ret) {
1717 err = ret;
1718 goto fail_iput;
1719 }
1720
1721 features = btrfs_super_incompat_flags(disk_super) &
1722 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1723 if (features) {
1724 printk(KERN_ERR "BTRFS: couldn't mount because of "
1725 "unsupported optional features (%Lx).\n",
1726 (unsigned long long)features);
1727 err = -EINVAL;
1728 goto fail_iput;
1729 }
1730
1731 features = btrfs_super_incompat_flags(disk_super);
1732 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1733 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1734 btrfs_set_super_incompat_flags(disk_super, features);
1735 }
1736
1737 features = btrfs_super_compat_ro_flags(disk_super) &
1738 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1739 if (!(sb->s_flags & MS_RDONLY) && features) {
1740 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1741 "unsupported option features (%Lx).\n",
1742 (unsigned long long)features);
1743 err = -EINVAL;
1744 goto fail_iput;
1745 }
1746
1747 btrfs_init_workers(&fs_info->generic_worker,
1748 "genwork", 1, NULL);
1749
1750 btrfs_init_workers(&fs_info->workers, "worker",
1751 fs_info->thread_pool_size,
1752 &fs_info->generic_worker);
1753
1754 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1755 fs_info->thread_pool_size,
1756 &fs_info->generic_worker);
1757
1758 btrfs_init_workers(&fs_info->submit_workers, "submit",
1759 min_t(u64, fs_devices->num_devices,
1760 fs_info->thread_pool_size),
1761 &fs_info->generic_worker);
1762 btrfs_init_workers(&fs_info->enospc_workers, "enospc",
1763 fs_info->thread_pool_size,
1764 &fs_info->generic_worker);
1765
1766 /* a higher idle thresh on the submit workers makes it much more
1767 * likely that bios will be send down in a sane order to the
1768 * devices
1769 */
1770 fs_info->submit_workers.idle_thresh = 64;
1771
1772 fs_info->workers.idle_thresh = 16;
1773 fs_info->workers.ordered = 1;
1774
1775 fs_info->delalloc_workers.idle_thresh = 2;
1776 fs_info->delalloc_workers.ordered = 1;
1777
1778 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1779 &fs_info->generic_worker);
1780 btrfs_init_workers(&fs_info->endio_workers, "endio",
1781 fs_info->thread_pool_size,
1782 &fs_info->generic_worker);
1783 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1784 fs_info->thread_pool_size,
1785 &fs_info->generic_worker);
1786 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1787 "endio-meta-write", fs_info->thread_pool_size,
1788 &fs_info->generic_worker);
1789 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1790 fs_info->thread_pool_size,
1791 &fs_info->generic_worker);
1792
1793 /*
1794 * endios are largely parallel and should have a very
1795 * low idle thresh
1796 */
1797 fs_info->endio_workers.idle_thresh = 4;
1798 fs_info->endio_meta_workers.idle_thresh = 4;
1799
1800 fs_info->endio_write_workers.idle_thresh = 2;
1801 fs_info->endio_meta_write_workers.idle_thresh = 2;
1802
1803 btrfs_start_workers(&fs_info->workers, 1);
1804 btrfs_start_workers(&fs_info->generic_worker, 1);
1805 btrfs_start_workers(&fs_info->submit_workers, 1);
1806 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1807 btrfs_start_workers(&fs_info->fixup_workers, 1);
1808 btrfs_start_workers(&fs_info->endio_workers, 1);
1809 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1810 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1811 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1812 btrfs_start_workers(&fs_info->enospc_workers, 1);
1813
1814 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1815 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1816 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1817
1818 nodesize = btrfs_super_nodesize(disk_super);
1819 leafsize = btrfs_super_leafsize(disk_super);
1820 sectorsize = btrfs_super_sectorsize(disk_super);
1821 stripesize = btrfs_super_stripesize(disk_super);
1822 tree_root->nodesize = nodesize;
1823 tree_root->leafsize = leafsize;
1824 tree_root->sectorsize = sectorsize;
1825 tree_root->stripesize = stripesize;
1826
1827 sb->s_blocksize = sectorsize;
1828 sb->s_blocksize_bits = blksize_bits(sectorsize);
1829
1830 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1831 sizeof(disk_super->magic))) {
1832 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1833 goto fail_sb_buffer;
1834 }
1835
1836 mutex_lock(&fs_info->chunk_mutex);
1837 ret = btrfs_read_sys_array(tree_root);
1838 mutex_unlock(&fs_info->chunk_mutex);
1839 if (ret) {
1840 printk(KERN_WARNING "btrfs: failed to read the system "
1841 "array on %s\n", sb->s_id);
1842 goto fail_sb_buffer;
1843 }
1844
1845 blocksize = btrfs_level_size(tree_root,
1846 btrfs_super_chunk_root_level(disk_super));
1847 generation = btrfs_super_chunk_root_generation(disk_super);
1848
1849 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1850 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1851
1852 chunk_root->node = read_tree_block(chunk_root,
1853 btrfs_super_chunk_root(disk_super),
1854 blocksize, generation);
1855 BUG_ON(!chunk_root->node);
1856 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1857 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1858 sb->s_id);
1859 goto fail_chunk_root;
1860 }
1861 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1862 chunk_root->commit_root = btrfs_root_node(chunk_root);
1863
1864 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1865 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1866 BTRFS_UUID_SIZE);
1867
1868 mutex_lock(&fs_info->chunk_mutex);
1869 ret = btrfs_read_chunk_tree(chunk_root);
1870 mutex_unlock(&fs_info->chunk_mutex);
1871 if (ret) {
1872 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1873 sb->s_id);
1874 goto fail_chunk_root;
1875 }
1876
1877 btrfs_close_extra_devices(fs_devices);
1878
1879 blocksize = btrfs_level_size(tree_root,
1880 btrfs_super_root_level(disk_super));
1881 generation = btrfs_super_generation(disk_super);
1882
1883 tree_root->node = read_tree_block(tree_root,
1884 btrfs_super_root(disk_super),
1885 blocksize, generation);
1886 if (!tree_root->node)
1887 goto fail_chunk_root;
1888 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1889 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1890 sb->s_id);
1891 goto fail_tree_root;
1892 }
1893 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1894 tree_root->commit_root = btrfs_root_node(tree_root);
1895
1896 ret = find_and_setup_root(tree_root, fs_info,
1897 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1898 if (ret)
1899 goto fail_tree_root;
1900 extent_root->track_dirty = 1;
1901
1902 ret = find_and_setup_root(tree_root, fs_info,
1903 BTRFS_DEV_TREE_OBJECTID, dev_root);
1904 if (ret)
1905 goto fail_extent_root;
1906 dev_root->track_dirty = 1;
1907
1908 ret = find_and_setup_root(tree_root, fs_info,
1909 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1910 if (ret)
1911 goto fail_dev_root;
1912
1913 csum_root->track_dirty = 1;
1914
1915 ret = btrfs_read_block_groups(extent_root);
1916 if (ret) {
1917 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1918 goto fail_block_groups;
1919 }
1920
1921 fs_info->generation = generation;
1922 fs_info->last_trans_committed = generation;
1923 fs_info->data_alloc_profile = (u64)-1;
1924 fs_info->metadata_alloc_profile = (u64)-1;
1925 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1926 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1927 "btrfs-cleaner");
1928 if (IS_ERR(fs_info->cleaner_kthread))
1929 goto fail_block_groups;
1930
1931 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1932 tree_root,
1933 "btrfs-transaction");
1934 if (IS_ERR(fs_info->transaction_kthread))
1935 goto fail_cleaner;
1936
1937 if (!btrfs_test_opt(tree_root, SSD) &&
1938 !btrfs_test_opt(tree_root, NOSSD) &&
1939 !fs_info->fs_devices->rotating) {
1940 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1941 "mode\n");
1942 btrfs_set_opt(fs_info->mount_opt, SSD);
1943 }
1944
1945 if (btrfs_super_log_root(disk_super) != 0) {
1946 u64 bytenr = btrfs_super_log_root(disk_super);
1947
1948 if (fs_devices->rw_devices == 0) {
1949 printk(KERN_WARNING "Btrfs log replay required "
1950 "on RO media\n");
1951 err = -EIO;
1952 goto fail_trans_kthread;
1953 }
1954 blocksize =
1955 btrfs_level_size(tree_root,
1956 btrfs_super_log_root_level(disk_super));
1957
1958 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1959 GFP_NOFS);
1960
1961 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1962 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1963
1964 log_tree_root->node = read_tree_block(tree_root, bytenr,
1965 blocksize,
1966 generation + 1);
1967 ret = btrfs_recover_log_trees(log_tree_root);
1968 BUG_ON(ret);
1969
1970 if (sb->s_flags & MS_RDONLY) {
1971 ret = btrfs_commit_super(tree_root);
1972 BUG_ON(ret);
1973 }
1974 }
1975
1976 ret = btrfs_find_orphan_roots(tree_root);
1977 BUG_ON(ret);
1978
1979 if (!(sb->s_flags & MS_RDONLY)) {
1980 ret = btrfs_recover_relocation(tree_root);
1981 if (ret < 0) {
1982 printk(KERN_WARNING
1983 "btrfs: failed to recover relocation\n");
1984 err = -EINVAL;
1985 goto fail_trans_kthread;
1986 }
1987 }
1988
1989 location.objectid = BTRFS_FS_TREE_OBJECTID;
1990 location.type = BTRFS_ROOT_ITEM_KEY;
1991 location.offset = (u64)-1;
1992
1993 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1994 if (!fs_info->fs_root)
1995 goto fail_trans_kthread;
1996
1997 if (!(sb->s_flags & MS_RDONLY)) {
1998 down_read(&fs_info->cleanup_work_sem);
1999 btrfs_orphan_cleanup(fs_info->fs_root);
2000 up_read(&fs_info->cleanup_work_sem);
2001 }
2002
2003 return tree_root;
2004
2005 fail_trans_kthread:
2006 kthread_stop(fs_info->transaction_kthread);
2007 fail_cleaner:
2008 kthread_stop(fs_info->cleaner_kthread);
2009
2010 /*
2011 * make sure we're done with the btree inode before we stop our
2012 * kthreads
2013 */
2014 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2015 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2016
2017 fail_block_groups:
2018 btrfs_free_block_groups(fs_info);
2019 free_extent_buffer(csum_root->node);
2020 free_extent_buffer(csum_root->commit_root);
2021 fail_dev_root:
2022 free_extent_buffer(dev_root->node);
2023 free_extent_buffer(dev_root->commit_root);
2024 fail_extent_root:
2025 free_extent_buffer(extent_root->node);
2026 free_extent_buffer(extent_root->commit_root);
2027 fail_tree_root:
2028 free_extent_buffer(tree_root->node);
2029 free_extent_buffer(tree_root->commit_root);
2030 fail_chunk_root:
2031 free_extent_buffer(chunk_root->node);
2032 free_extent_buffer(chunk_root->commit_root);
2033 fail_sb_buffer:
2034 btrfs_stop_workers(&fs_info->generic_worker);
2035 btrfs_stop_workers(&fs_info->fixup_workers);
2036 btrfs_stop_workers(&fs_info->delalloc_workers);
2037 btrfs_stop_workers(&fs_info->workers);
2038 btrfs_stop_workers(&fs_info->endio_workers);
2039 btrfs_stop_workers(&fs_info->endio_meta_workers);
2040 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2041 btrfs_stop_workers(&fs_info->endio_write_workers);
2042 btrfs_stop_workers(&fs_info->submit_workers);
2043 btrfs_stop_workers(&fs_info->enospc_workers);
2044 fail_iput:
2045 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2046 iput(fs_info->btree_inode);
2047
2048 btrfs_close_devices(fs_info->fs_devices);
2049 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2050 fail_bdi:
2051 bdi_destroy(&fs_info->bdi);
2052 fail_srcu:
2053 cleanup_srcu_struct(&fs_info->subvol_srcu);
2054 fail:
2055 kfree(extent_root);
2056 kfree(tree_root);
2057 kfree(fs_info);
2058 kfree(chunk_root);
2059 kfree(dev_root);
2060 kfree(csum_root);
2061 return ERR_PTR(err);
2062 }
2063
2064 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2065 {
2066 char b[BDEVNAME_SIZE];
2067
2068 if (uptodate) {
2069 set_buffer_uptodate(bh);
2070 } else {
2071 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
2072 printk(KERN_WARNING "lost page write due to "
2073 "I/O error on %s\n",
2074 bdevname(bh->b_bdev, b));
2075 }
2076 /* note, we dont' set_buffer_write_io_error because we have
2077 * our own ways of dealing with the IO errors
2078 */
2079 clear_buffer_uptodate(bh);
2080 }
2081 unlock_buffer(bh);
2082 put_bh(bh);
2083 }
2084
2085 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2086 {
2087 struct buffer_head *bh;
2088 struct buffer_head *latest = NULL;
2089 struct btrfs_super_block *super;
2090 int i;
2091 u64 transid = 0;
2092 u64 bytenr;
2093
2094 /* we would like to check all the supers, but that would make
2095 * a btrfs mount succeed after a mkfs from a different FS.
2096 * So, we need to add a special mount option to scan for
2097 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2098 */
2099 for (i = 0; i < 1; i++) {
2100 bytenr = btrfs_sb_offset(i);
2101 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2102 break;
2103 bh = __bread(bdev, bytenr / 4096, 4096);
2104 if (!bh)
2105 continue;
2106
2107 super = (struct btrfs_super_block *)bh->b_data;
2108 if (btrfs_super_bytenr(super) != bytenr ||
2109 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2110 sizeof(super->magic))) {
2111 brelse(bh);
2112 continue;
2113 }
2114
2115 if (!latest || btrfs_super_generation(super) > transid) {
2116 brelse(latest);
2117 latest = bh;
2118 transid = btrfs_super_generation(super);
2119 } else {
2120 brelse(bh);
2121 }
2122 }
2123 return latest;
2124 }
2125
2126 /*
2127 * this should be called twice, once with wait == 0 and
2128 * once with wait == 1. When wait == 0 is done, all the buffer heads
2129 * we write are pinned.
2130 *
2131 * They are released when wait == 1 is done.
2132 * max_mirrors must be the same for both runs, and it indicates how
2133 * many supers on this one device should be written.
2134 *
2135 * max_mirrors == 0 means to write them all.
2136 */
2137 static int write_dev_supers(struct btrfs_device *device,
2138 struct btrfs_super_block *sb,
2139 int do_barriers, int wait, int max_mirrors)
2140 {
2141 struct buffer_head *bh;
2142 int i;
2143 int ret;
2144 int errors = 0;
2145 u32 crc;
2146 u64 bytenr;
2147 int last_barrier = 0;
2148
2149 if (max_mirrors == 0)
2150 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2151
2152 /* make sure only the last submit_bh does a barrier */
2153 if (do_barriers) {
2154 for (i = 0; i < max_mirrors; i++) {
2155 bytenr = btrfs_sb_offset(i);
2156 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2157 device->total_bytes)
2158 break;
2159 last_barrier = i;
2160 }
2161 }
2162
2163 for (i = 0; i < max_mirrors; i++) {
2164 bytenr = btrfs_sb_offset(i);
2165 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2166 break;
2167
2168 if (wait) {
2169 bh = __find_get_block(device->bdev, bytenr / 4096,
2170 BTRFS_SUPER_INFO_SIZE);
2171 BUG_ON(!bh);
2172 wait_on_buffer(bh);
2173 if (!buffer_uptodate(bh))
2174 errors++;
2175
2176 /* drop our reference */
2177 brelse(bh);
2178
2179 /* drop the reference from the wait == 0 run */
2180 brelse(bh);
2181 continue;
2182 } else {
2183 btrfs_set_super_bytenr(sb, bytenr);
2184
2185 crc = ~(u32)0;
2186 crc = btrfs_csum_data(NULL, (char *)sb +
2187 BTRFS_CSUM_SIZE, crc,
2188 BTRFS_SUPER_INFO_SIZE -
2189 BTRFS_CSUM_SIZE);
2190 btrfs_csum_final(crc, sb->csum);
2191
2192 /*
2193 * one reference for us, and we leave it for the
2194 * caller
2195 */
2196 bh = __getblk(device->bdev, bytenr / 4096,
2197 BTRFS_SUPER_INFO_SIZE);
2198 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2199
2200 /* one reference for submit_bh */
2201 get_bh(bh);
2202
2203 set_buffer_uptodate(bh);
2204 lock_buffer(bh);
2205 bh->b_end_io = btrfs_end_buffer_write_sync;
2206 }
2207
2208 if (i == last_barrier && do_barriers && device->barriers) {
2209 ret = submit_bh(WRITE_BARRIER, bh);
2210 if (ret == -EOPNOTSUPP) {
2211 printk("btrfs: disabling barriers on dev %s\n",
2212 device->name);
2213 set_buffer_uptodate(bh);
2214 device->barriers = 0;
2215 /* one reference for submit_bh */
2216 get_bh(bh);
2217 lock_buffer(bh);
2218 ret = submit_bh(WRITE_SYNC, bh);
2219 }
2220 } else {
2221 ret = submit_bh(WRITE_SYNC, bh);
2222 }
2223
2224 if (ret)
2225 errors++;
2226 }
2227 return errors < i ? 0 : -1;
2228 }
2229
2230 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2231 {
2232 struct list_head *head;
2233 struct btrfs_device *dev;
2234 struct btrfs_super_block *sb;
2235 struct btrfs_dev_item *dev_item;
2236 int ret;
2237 int do_barriers;
2238 int max_errors;
2239 int total_errors = 0;
2240 u64 flags;
2241
2242 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2243 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2244
2245 sb = &root->fs_info->super_for_commit;
2246 dev_item = &sb->dev_item;
2247
2248 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2249 head = &root->fs_info->fs_devices->devices;
2250 list_for_each_entry(dev, head, dev_list) {
2251 if (!dev->bdev) {
2252 total_errors++;
2253 continue;
2254 }
2255 if (!dev->in_fs_metadata || !dev->writeable)
2256 continue;
2257
2258 btrfs_set_stack_device_generation(dev_item, 0);
2259 btrfs_set_stack_device_type(dev_item, dev->type);
2260 btrfs_set_stack_device_id(dev_item, dev->devid);
2261 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2262 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2263 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2264 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2265 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2266 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2267 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2268
2269 flags = btrfs_super_flags(sb);
2270 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2271
2272 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2273 if (ret)
2274 total_errors++;
2275 }
2276 if (total_errors > max_errors) {
2277 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2278 total_errors);
2279 BUG();
2280 }
2281
2282 total_errors = 0;
2283 list_for_each_entry(dev, head, dev_list) {
2284 if (!dev->bdev)
2285 continue;
2286 if (!dev->in_fs_metadata || !dev->writeable)
2287 continue;
2288
2289 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2290 if (ret)
2291 total_errors++;
2292 }
2293 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2294 if (total_errors > max_errors) {
2295 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2296 total_errors);
2297 BUG();
2298 }
2299 return 0;
2300 }
2301
2302 int write_ctree_super(struct btrfs_trans_handle *trans,
2303 struct btrfs_root *root, int max_mirrors)
2304 {
2305 int ret;
2306
2307 ret = write_all_supers(root, max_mirrors);
2308 return ret;
2309 }
2310
2311 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2312 {
2313 spin_lock(&fs_info->fs_roots_radix_lock);
2314 radix_tree_delete(&fs_info->fs_roots_radix,
2315 (unsigned long)root->root_key.objectid);
2316 spin_unlock(&fs_info->fs_roots_radix_lock);
2317
2318 if (btrfs_root_refs(&root->root_item) == 0)
2319 synchronize_srcu(&fs_info->subvol_srcu);
2320
2321 free_fs_root(root);
2322 return 0;
2323 }
2324
2325 static void free_fs_root(struct btrfs_root *root)
2326 {
2327 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2328 if (root->anon_super.s_dev) {
2329 down_write(&root->anon_super.s_umount);
2330 kill_anon_super(&root->anon_super);
2331 }
2332 free_extent_buffer(root->node);
2333 free_extent_buffer(root->commit_root);
2334 kfree(root->name);
2335 kfree(root);
2336 }
2337
2338 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2339 {
2340 int ret;
2341 struct btrfs_root *gang[8];
2342 int i;
2343
2344 while (!list_empty(&fs_info->dead_roots)) {
2345 gang[0] = list_entry(fs_info->dead_roots.next,
2346 struct btrfs_root, root_list);
2347 list_del(&gang[0]->root_list);
2348
2349 if (gang[0]->in_radix) {
2350 btrfs_free_fs_root(fs_info, gang[0]);
2351 } else {
2352 free_extent_buffer(gang[0]->node);
2353 free_extent_buffer(gang[0]->commit_root);
2354 kfree(gang[0]);
2355 }
2356 }
2357
2358 while (1) {
2359 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2360 (void **)gang, 0,
2361 ARRAY_SIZE(gang));
2362 if (!ret)
2363 break;
2364 for (i = 0; i < ret; i++)
2365 btrfs_free_fs_root(fs_info, gang[i]);
2366 }
2367 return 0;
2368 }
2369
2370 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2371 {
2372 u64 root_objectid = 0;
2373 struct btrfs_root *gang[8];
2374 int i;
2375 int ret;
2376
2377 while (1) {
2378 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2379 (void **)gang, root_objectid,
2380 ARRAY_SIZE(gang));
2381 if (!ret)
2382 break;
2383
2384 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2385 for (i = 0; i < ret; i++) {
2386 root_objectid = gang[i]->root_key.objectid;
2387 btrfs_orphan_cleanup(gang[i]);
2388 }
2389 root_objectid++;
2390 }
2391 return 0;
2392 }
2393
2394 int btrfs_commit_super(struct btrfs_root *root)
2395 {
2396 struct btrfs_trans_handle *trans;
2397 int ret;
2398
2399 mutex_lock(&root->fs_info->cleaner_mutex);
2400 btrfs_run_delayed_iputs(root);
2401 btrfs_clean_old_snapshots(root);
2402 mutex_unlock(&root->fs_info->cleaner_mutex);
2403
2404 /* wait until ongoing cleanup work done */
2405 down_write(&root->fs_info->cleanup_work_sem);
2406 up_write(&root->fs_info->cleanup_work_sem);
2407
2408 trans = btrfs_start_transaction(root, 1);
2409 ret = btrfs_commit_transaction(trans, root);
2410 BUG_ON(ret);
2411 /* run commit again to drop the original snapshot */
2412 trans = btrfs_start_transaction(root, 1);
2413 btrfs_commit_transaction(trans, root);
2414 ret = btrfs_write_and_wait_transaction(NULL, root);
2415 BUG_ON(ret);
2416
2417 ret = write_ctree_super(NULL, root, 0);
2418 return ret;
2419 }
2420
2421 int close_ctree(struct btrfs_root *root)
2422 {
2423 struct btrfs_fs_info *fs_info = root->fs_info;
2424 int ret;
2425
2426 fs_info->closing = 1;
2427 smp_mb();
2428
2429 kthread_stop(root->fs_info->transaction_kthread);
2430 kthread_stop(root->fs_info->cleaner_kthread);
2431
2432 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2433 ret = btrfs_commit_super(root);
2434 if (ret)
2435 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2436 }
2437
2438 fs_info->closing = 2;
2439 smp_mb();
2440
2441 if (fs_info->delalloc_bytes) {
2442 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2443 (unsigned long long)fs_info->delalloc_bytes);
2444 }
2445 if (fs_info->total_ref_cache_size) {
2446 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2447 (unsigned long long)fs_info->total_ref_cache_size);
2448 }
2449
2450 free_extent_buffer(fs_info->extent_root->node);
2451 free_extent_buffer(fs_info->extent_root->commit_root);
2452 free_extent_buffer(fs_info->tree_root->node);
2453 free_extent_buffer(fs_info->tree_root->commit_root);
2454 free_extent_buffer(root->fs_info->chunk_root->node);
2455 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2456 free_extent_buffer(root->fs_info->dev_root->node);
2457 free_extent_buffer(root->fs_info->dev_root->commit_root);
2458 free_extent_buffer(root->fs_info->csum_root->node);
2459 free_extent_buffer(root->fs_info->csum_root->commit_root);
2460
2461 btrfs_free_block_groups(root->fs_info);
2462
2463 del_fs_roots(fs_info);
2464
2465 iput(fs_info->btree_inode);
2466
2467 btrfs_stop_workers(&fs_info->generic_worker);
2468 btrfs_stop_workers(&fs_info->fixup_workers);
2469 btrfs_stop_workers(&fs_info->delalloc_workers);
2470 btrfs_stop_workers(&fs_info->workers);
2471 btrfs_stop_workers(&fs_info->endio_workers);
2472 btrfs_stop_workers(&fs_info->endio_meta_workers);
2473 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2474 btrfs_stop_workers(&fs_info->endio_write_workers);
2475 btrfs_stop_workers(&fs_info->submit_workers);
2476 btrfs_stop_workers(&fs_info->enospc_workers);
2477
2478 btrfs_close_devices(fs_info->fs_devices);
2479 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2480
2481 bdi_destroy(&fs_info->bdi);
2482 cleanup_srcu_struct(&fs_info->subvol_srcu);
2483
2484 kfree(fs_info->extent_root);
2485 kfree(fs_info->tree_root);
2486 kfree(fs_info->chunk_root);
2487 kfree(fs_info->dev_root);
2488 kfree(fs_info->csum_root);
2489 return 0;
2490 }
2491
2492 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2493 {
2494 int ret;
2495 struct inode *btree_inode = buf->first_page->mapping->host;
2496
2497 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2498 NULL);
2499 if (!ret)
2500 return ret;
2501
2502 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2503 parent_transid);
2504 return !ret;
2505 }
2506
2507 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2508 {
2509 struct inode *btree_inode = buf->first_page->mapping->host;
2510 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2511 buf);
2512 }
2513
2514 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2515 {
2516 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2517 u64 transid = btrfs_header_generation(buf);
2518 struct inode *btree_inode = root->fs_info->btree_inode;
2519 int was_dirty;
2520
2521 btrfs_assert_tree_locked(buf);
2522 if (transid != root->fs_info->generation) {
2523 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2524 "found %llu running %llu\n",
2525 (unsigned long long)buf->start,
2526 (unsigned long long)transid,
2527 (unsigned long long)root->fs_info->generation);
2528 WARN_ON(1);
2529 }
2530 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2531 buf);
2532 if (!was_dirty) {
2533 spin_lock(&root->fs_info->delalloc_lock);
2534 root->fs_info->dirty_metadata_bytes += buf->len;
2535 spin_unlock(&root->fs_info->delalloc_lock);
2536 }
2537 }
2538
2539 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2540 {
2541 /*
2542 * looks as though older kernels can get into trouble with
2543 * this code, they end up stuck in balance_dirty_pages forever
2544 */
2545 u64 num_dirty;
2546 unsigned long thresh = 32 * 1024 * 1024;
2547
2548 if (current->flags & PF_MEMALLOC)
2549 return;
2550
2551 num_dirty = root->fs_info->dirty_metadata_bytes;
2552
2553 if (num_dirty > thresh) {
2554 balance_dirty_pages_ratelimited_nr(
2555 root->fs_info->btree_inode->i_mapping, 1);
2556 }
2557 return;
2558 }
2559
2560 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2561 {
2562 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2563 int ret;
2564 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2565 if (ret == 0)
2566 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2567 return ret;
2568 }
2569
2570 int btree_lock_page_hook(struct page *page)
2571 {
2572 struct inode *inode = page->mapping->host;
2573 struct btrfs_root *root = BTRFS_I(inode)->root;
2574 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2575 struct extent_buffer *eb;
2576 unsigned long len;
2577 u64 bytenr = page_offset(page);
2578
2579 if (page->private == EXTENT_PAGE_PRIVATE)
2580 goto out;
2581
2582 len = page->private >> 2;
2583 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2584 if (!eb)
2585 goto out;
2586
2587 btrfs_tree_lock(eb);
2588 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2589
2590 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2591 spin_lock(&root->fs_info->delalloc_lock);
2592 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2593 root->fs_info->dirty_metadata_bytes -= eb->len;
2594 else
2595 WARN_ON(1);
2596 spin_unlock(&root->fs_info->delalloc_lock);
2597 }
2598
2599 btrfs_tree_unlock(eb);
2600 free_extent_buffer(eb);
2601 out:
2602 lock_page(page);
2603 return 0;
2604 }
2605
2606 static struct extent_io_ops btree_extent_io_ops = {
2607 .write_cache_pages_lock_hook = btree_lock_page_hook,
2608 .readpage_end_io_hook = btree_readpage_end_io_hook,
2609 .submit_bio_hook = btree_submit_bio_hook,
2610 /* note we're sharing with inode.c for the merge bio hook */
2611 .merge_bio_hook = btrfs_merge_bio_hook,
2612 };
Linus' kernel tree