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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / disk-io.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/crc32c.h>
30 #include <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 static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
48
49 /*
50 * end_io_wq structs are used to do processing in task context when an IO is
51 * complete. This is used during reads to verify checksums, and it is used
52 * by writes to insert metadata for new file extents after IO is complete.
53 */
54 struct end_io_wq {
55 struct bio *bio;
56 bio_end_io_t *end_io;
57 void *private;
58 struct btrfs_fs_info *info;
59 int error;
60 int metadata;
61 struct list_head list;
62 struct btrfs_work work;
63 };
64
65 /*
66 * async submit bios are used to offload expensive checksumming
67 * onto the worker threads. They checksum file and metadata bios
68 * just before they are sent down the IO stack.
69 */
70 struct async_submit_bio {
71 struct inode *inode;
72 struct bio *bio;
73 struct list_head list;
74 extent_submit_bio_hook_t *submit_bio_start;
75 extent_submit_bio_hook_t *submit_bio_done;
76 int rw;
77 int mirror_num;
78 unsigned long bio_flags;
79 struct btrfs_work work;
80 };
81
82 /* These are used to set the lockdep class on the extent buffer locks.
83 * The class is set by the readpage_end_io_hook after the buffer has
84 * passed csum validation but before the pages are unlocked.
85 *
86 * The lockdep class is also set by btrfs_init_new_buffer on freshly
87 * allocated blocks.
88 *
89 * The class is based on the level in the tree block, which allows lockdep
90 * to know that lower nodes nest inside the locks of higher nodes.
91 *
92 * We also add a check to make sure the highest level of the tree is
93 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
94 * code needs update as well.
95 */
96 #ifdef CONFIG_DEBUG_LOCK_ALLOC
97 # if BTRFS_MAX_LEVEL != 8
98 # error
99 # endif
100 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
101 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
102 /* leaf */
103 "btrfs-extent-00",
104 "btrfs-extent-01",
105 "btrfs-extent-02",
106 "btrfs-extent-03",
107 "btrfs-extent-04",
108 "btrfs-extent-05",
109 "btrfs-extent-06",
110 "btrfs-extent-07",
111 /* highest possible level */
112 "btrfs-extent-08",
113 };
114 #endif
115
116 /*
117 * extents on the btree inode are pretty simple, there's one extent
118 * that covers the entire device
119 */
120 static struct extent_map *btree_get_extent(struct inode *inode,
121 struct page *page, size_t page_offset, u64 start, u64 len,
122 int create)
123 {
124 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
125 struct extent_map *em;
126 int ret;
127
128 read_lock(&em_tree->lock);
129 em = lookup_extent_mapping(em_tree, start, len);
130 if (em) {
131 em->bdev =
132 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
133 read_unlock(&em_tree->lock);
134 goto out;
135 }
136 read_unlock(&em_tree->lock);
137
138 em = alloc_extent_map(GFP_NOFS);
139 if (!em) {
140 em = ERR_PTR(-ENOMEM);
141 goto out;
142 }
143 em->start = 0;
144 em->len = (u64)-1;
145 em->block_len = (u64)-1;
146 em->block_start = 0;
147 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
148
149 write_lock(&em_tree->lock);
150 ret = add_extent_mapping(em_tree, em);
151 if (ret == -EEXIST) {
152 u64 failed_start = em->start;
153 u64 failed_len = em->len;
154
155 free_extent_map(em);
156 em = lookup_extent_mapping(em_tree, start, len);
157 if (em) {
158 ret = 0;
159 } else {
160 em = lookup_extent_mapping(em_tree, failed_start,
161 failed_len);
162 ret = -EIO;
163 }
164 } else if (ret) {
165 free_extent_map(em);
166 em = NULL;
167 }
168 write_unlock(&em_tree->lock);
169
170 if (ret)
171 em = ERR_PTR(ret);
172 out:
173 return em;
174 }
175
176 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
177 {
178 return crc32c(seed, data, len);
179 }
180
181 void btrfs_csum_final(u32 crc, char *result)
182 {
183 *(__le32 *)result = ~cpu_to_le32(crc);
184 }
185
186 /*
187 * compute the csum for a btree block, and either verify it or write it
188 * into the csum field of the block.
189 */
190 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
191 int verify)
192 {
193 u16 csum_size =
194 btrfs_super_csum_size(&root->fs_info->super_copy);
195 char *result = NULL;
196 unsigned long len;
197 unsigned long cur_len;
198 unsigned long offset = BTRFS_CSUM_SIZE;
199 char *map_token = NULL;
200 char *kaddr;
201 unsigned long map_start;
202 unsigned long map_len;
203 int err;
204 u32 crc = ~(u32)0;
205 unsigned long inline_result;
206
207 len = buf->len - offset;
208 while (len > 0) {
209 err = map_private_extent_buffer(buf, offset, 32,
210 &map_token, &kaddr,
211 &map_start, &map_len, KM_USER0);
212 if (err)
213 return 1;
214 cur_len = min(len, map_len - (offset - map_start));
215 crc = btrfs_csum_data(root, kaddr + offset - map_start,
216 crc, cur_len);
217 len -= cur_len;
218 offset += cur_len;
219 unmap_extent_buffer(buf, map_token, KM_USER0);
220 }
221 if (csum_size > sizeof(inline_result)) {
222 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
223 if (!result)
224 return 1;
225 } else {
226 result = (char *)&inline_result;
227 }
228
229 btrfs_csum_final(crc, result);
230
231 if (verify) {
232 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
233 u32 val;
234 u32 found = 0;
235 memcpy(&found, result, csum_size);
236
237 read_extent_buffer(buf, &val, 0, csum_size);
238 if (printk_ratelimit()) {
239 printk(KERN_INFO "btrfs: %s checksum verify "
240 "failed on %llu wanted %X found %X "
241 "level %d\n",
242 root->fs_info->sb->s_id,
243 (unsigned long long)buf->start, val, found,
244 btrfs_header_level(buf));
245 }
246 if (result != (char *)&inline_result)
247 kfree(result);
248 return 1;
249 }
250 } else {
251 write_extent_buffer(buf, result, 0, csum_size);
252 }
253 if (result != (char *)&inline_result)
254 kfree(result);
255 return 0;
256 }
257
258 /*
259 * we can't consider a given block up to date unless the transid of the
260 * block matches the transid in the parent node's pointer. This is how we
261 * detect blocks that either didn't get written at all or got written
262 * in the wrong place.
263 */
264 static int verify_parent_transid(struct extent_io_tree *io_tree,
265 struct extent_buffer *eb, u64 parent_transid)
266 {
267 struct extent_state *cached_state = NULL;
268 int ret;
269
270 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
271 return 0;
272
273 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
274 0, &cached_state, GFP_NOFS);
275 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
276 btrfs_header_generation(eb) == parent_transid) {
277 ret = 0;
278 goto out;
279 }
280 if (printk_ratelimit()) {
281 printk("parent transid verify failed on %llu wanted %llu "
282 "found %llu\n",
283 (unsigned long long)eb->start,
284 (unsigned long long)parent_transid,
285 (unsigned long long)btrfs_header_generation(eb));
286 }
287 ret = 1;
288 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
289 out:
290 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
291 &cached_state, GFP_NOFS);
292 return ret;
293 }
294
295 /*
296 * helper to read a given tree block, doing retries as required when
297 * the checksums don't match and we have alternate mirrors to try.
298 */
299 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
300 struct extent_buffer *eb,
301 u64 start, u64 parent_transid)
302 {
303 struct extent_io_tree *io_tree;
304 int ret;
305 int num_copies = 0;
306 int mirror_num = 0;
307
308 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
309 while (1) {
310 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
311 btree_get_extent, mirror_num);
312 if (!ret &&
313 !verify_parent_transid(io_tree, eb, parent_transid))
314 return ret;
315
316 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
317 eb->start, eb->len);
318 if (num_copies == 1)
319 return ret;
320
321 mirror_num++;
322 if (mirror_num > num_copies)
323 return ret;
324 }
325 return -EIO;
326 }
327
328 /*
329 * checksum a dirty tree block before IO. This has extra checks to make sure
330 * we only fill in the checksum field in the first page of a multi-page block
331 */
332
333 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
334 {
335 struct extent_io_tree *tree;
336 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
337 u64 found_start;
338 int found_level;
339 unsigned long len;
340 struct extent_buffer *eb;
341 int ret;
342
343 tree = &BTRFS_I(page->mapping->host)->io_tree;
344
345 if (page->private == EXTENT_PAGE_PRIVATE)
346 goto out;
347 if (!page->private)
348 goto out;
349 len = page->private >> 2;
350 WARN_ON(len == 0);
351
352 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
353 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
354 btrfs_header_generation(eb));
355 BUG_ON(ret);
356 found_start = btrfs_header_bytenr(eb);
357 if (found_start != start) {
358 WARN_ON(1);
359 goto err;
360 }
361 if (eb->first_page != page) {
362 WARN_ON(1);
363 goto err;
364 }
365 if (!PageUptodate(page)) {
366 WARN_ON(1);
367 goto err;
368 }
369 found_level = btrfs_header_level(eb);
370
371 csum_tree_block(root, eb, 0);
372 err:
373 free_extent_buffer(eb);
374 out:
375 return 0;
376 }
377
378 static int check_tree_block_fsid(struct btrfs_root *root,
379 struct extent_buffer *eb)
380 {
381 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
382 u8 fsid[BTRFS_UUID_SIZE];
383 int ret = 1;
384
385 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
386 BTRFS_FSID_SIZE);
387 while (fs_devices) {
388 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
389 ret = 0;
390 break;
391 }
392 fs_devices = fs_devices->seed;
393 }
394 return ret;
395 }
396
397 #ifdef CONFIG_DEBUG_LOCK_ALLOC
398 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
399 {
400 lockdep_set_class_and_name(&eb->lock,
401 &btrfs_eb_class[level],
402 btrfs_eb_name[level]);
403 }
404 #endif
405
406 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
407 struct extent_state *state)
408 {
409 struct extent_io_tree *tree;
410 u64 found_start;
411 int found_level;
412 unsigned long len;
413 struct extent_buffer *eb;
414 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
415 int ret = 0;
416
417 tree = &BTRFS_I(page->mapping->host)->io_tree;
418 if (page->private == EXTENT_PAGE_PRIVATE)
419 goto out;
420 if (!page->private)
421 goto out;
422
423 len = page->private >> 2;
424 WARN_ON(len == 0);
425
426 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
427
428 found_start = btrfs_header_bytenr(eb);
429 if (found_start != start) {
430 if (printk_ratelimit()) {
431 printk(KERN_INFO "btrfs bad tree block start "
432 "%llu %llu\n",
433 (unsigned long long)found_start,
434 (unsigned long long)eb->start);
435 }
436 ret = -EIO;
437 goto err;
438 }
439 if (eb->first_page != page) {
440 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
441 eb->first_page->index, page->index);
442 WARN_ON(1);
443 ret = -EIO;
444 goto err;
445 }
446 if (check_tree_block_fsid(root, eb)) {
447 if (printk_ratelimit()) {
448 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
449 (unsigned long long)eb->start);
450 }
451 ret = -EIO;
452 goto err;
453 }
454 found_level = btrfs_header_level(eb);
455
456 btrfs_set_buffer_lockdep_class(eb, found_level);
457
458 ret = csum_tree_block(root, eb, 1);
459 if (ret)
460 ret = -EIO;
461
462 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
463 end = eb->start + end - 1;
464 err:
465 free_extent_buffer(eb);
466 out:
467 return ret;
468 }
469
470 static void end_workqueue_bio(struct bio *bio, int err)
471 {
472 struct end_io_wq *end_io_wq = bio->bi_private;
473 struct btrfs_fs_info *fs_info;
474
475 fs_info = end_io_wq->info;
476 end_io_wq->error = err;
477 end_io_wq->work.func = end_workqueue_fn;
478 end_io_wq->work.flags = 0;
479
480 if (bio->bi_rw & (1 << BIO_RW)) {
481 if (end_io_wq->metadata)
482 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
483 &end_io_wq->work);
484 else
485 btrfs_queue_worker(&fs_info->endio_write_workers,
486 &end_io_wq->work);
487 } else {
488 if (end_io_wq->metadata)
489 btrfs_queue_worker(&fs_info->endio_meta_workers,
490 &end_io_wq->work);
491 else
492 btrfs_queue_worker(&fs_info->endio_workers,
493 &end_io_wq->work);
494 }
495 }
496
497 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
498 int metadata)
499 {
500 struct end_io_wq *end_io_wq;
501 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
502 if (!end_io_wq)
503 return -ENOMEM;
504
505 end_io_wq->private = bio->bi_private;
506 end_io_wq->end_io = bio->bi_end_io;
507 end_io_wq->info = info;
508 end_io_wq->error = 0;
509 end_io_wq->bio = bio;
510 end_io_wq->metadata = metadata;
511
512 bio->bi_private = end_io_wq;
513 bio->bi_end_io = end_workqueue_bio;
514 return 0;
515 }
516
517 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
518 {
519 unsigned long limit = min_t(unsigned long,
520 info->workers.max_workers,
521 info->fs_devices->open_devices);
522 return 256 * limit;
523 }
524
525 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
526 {
527 return atomic_read(&info->nr_async_bios) >
528 btrfs_async_submit_limit(info);
529 }
530
531 static void run_one_async_start(struct btrfs_work *work)
532 {
533 struct btrfs_fs_info *fs_info;
534 struct async_submit_bio *async;
535
536 async = container_of(work, struct async_submit_bio, work);
537 fs_info = BTRFS_I(async->inode)->root->fs_info;
538 async->submit_bio_start(async->inode, async->rw, async->bio,
539 async->mirror_num, async->bio_flags);
540 }
541
542 static void run_one_async_done(struct btrfs_work *work)
543 {
544 struct btrfs_fs_info *fs_info;
545 struct async_submit_bio *async;
546 int limit;
547
548 async = container_of(work, struct async_submit_bio, work);
549 fs_info = BTRFS_I(async->inode)->root->fs_info;
550
551 limit = btrfs_async_submit_limit(fs_info);
552 limit = limit * 2 / 3;
553
554 atomic_dec(&fs_info->nr_async_submits);
555
556 if (atomic_read(&fs_info->nr_async_submits) < limit &&
557 waitqueue_active(&fs_info->async_submit_wait))
558 wake_up(&fs_info->async_submit_wait);
559
560 async->submit_bio_done(async->inode, async->rw, async->bio,
561 async->mirror_num, async->bio_flags);
562 }
563
564 static void run_one_async_free(struct btrfs_work *work)
565 {
566 struct async_submit_bio *async;
567
568 async = container_of(work, struct async_submit_bio, work);
569 kfree(async);
570 }
571
572 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
573 int rw, struct bio *bio, int mirror_num,
574 unsigned long bio_flags,
575 extent_submit_bio_hook_t *submit_bio_start,
576 extent_submit_bio_hook_t *submit_bio_done)
577 {
578 struct async_submit_bio *async;
579
580 async = kmalloc(sizeof(*async), GFP_NOFS);
581 if (!async)
582 return -ENOMEM;
583
584 async->inode = inode;
585 async->rw = rw;
586 async->bio = bio;
587 async->mirror_num = mirror_num;
588 async->submit_bio_start = submit_bio_start;
589 async->submit_bio_done = submit_bio_done;
590
591 async->work.func = run_one_async_start;
592 async->work.ordered_func = run_one_async_done;
593 async->work.ordered_free = run_one_async_free;
594
595 async->work.flags = 0;
596 async->bio_flags = bio_flags;
597
598 atomic_inc(&fs_info->nr_async_submits);
599
600 if (rw & (1 << BIO_RW_SYNCIO))
601 btrfs_set_work_high_prio(&async->work);
602
603 btrfs_queue_worker(&fs_info->workers, &async->work);
604
605 while (atomic_read(&fs_info->async_submit_draining) &&
606 atomic_read(&fs_info->nr_async_submits)) {
607 wait_event(fs_info->async_submit_wait,
608 (atomic_read(&fs_info->nr_async_submits) == 0));
609 }
610
611 return 0;
612 }
613
614 static int btree_csum_one_bio(struct bio *bio)
615 {
616 struct bio_vec *bvec = bio->bi_io_vec;
617 int bio_index = 0;
618 struct btrfs_root *root;
619
620 WARN_ON(bio->bi_vcnt <= 0);
621 while (bio_index < bio->bi_vcnt) {
622 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
623 csum_dirty_buffer(root, bvec->bv_page);
624 bio_index++;
625 bvec++;
626 }
627 return 0;
628 }
629
630 static int __btree_submit_bio_start(struct inode *inode, int rw,
631 struct bio *bio, int mirror_num,
632 unsigned long bio_flags)
633 {
634 /*
635 * when we're called for a write, we're already in the async
636 * submission context. Just jump into btrfs_map_bio
637 */
638 btree_csum_one_bio(bio);
639 return 0;
640 }
641
642 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
643 int mirror_num, unsigned long bio_flags)
644 {
645 /*
646 * when we're called for a write, we're already in the async
647 * submission context. Just jump into btrfs_map_bio
648 */
649 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
650 }
651
652 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
653 int mirror_num, unsigned long bio_flags)
654 {
655 int ret;
656
657 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
658 bio, 1);
659 BUG_ON(ret);
660
661 if (!(rw & (1 << BIO_RW))) {
662 /*
663 * called for a read, do the setup so that checksum validation
664 * can happen in the async kernel threads
665 */
666 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
667 mirror_num, 0);
668 }
669
670 /*
671 * kthread helpers are used to submit writes so that checksumming
672 * can happen in parallel across all CPUs
673 */
674 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
675 inode, rw, bio, mirror_num, 0,
676 __btree_submit_bio_start,
677 __btree_submit_bio_done);
678 }
679
680 static int btree_writepage(struct page *page, struct writeback_control *wbc)
681 {
682 struct extent_io_tree *tree;
683 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
684 struct extent_buffer *eb;
685 int was_dirty;
686
687 tree = &BTRFS_I(page->mapping->host)->io_tree;
688 if (!(current->flags & PF_MEMALLOC)) {
689 return extent_write_full_page(tree, page,
690 btree_get_extent, wbc);
691 }
692
693 redirty_page_for_writepage(wbc, page);
694 eb = btrfs_find_tree_block(root, page_offset(page),
695 PAGE_CACHE_SIZE);
696 WARN_ON(!eb);
697
698 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
699 if (!was_dirty) {
700 spin_lock(&root->fs_info->delalloc_lock);
701 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
702 spin_unlock(&root->fs_info->delalloc_lock);
703 }
704 free_extent_buffer(eb);
705
706 unlock_page(page);
707 return 0;
708 }
709
710 static int btree_writepages(struct address_space *mapping,
711 struct writeback_control *wbc)
712 {
713 struct extent_io_tree *tree;
714 tree = &BTRFS_I(mapping->host)->io_tree;
715 if (wbc->sync_mode == WB_SYNC_NONE) {
716 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
717 u64 num_dirty;
718 unsigned long thresh = 32 * 1024 * 1024;
719
720 if (wbc->for_kupdate)
721 return 0;
722
723 /* this is a bit racy, but that's ok */
724 num_dirty = root->fs_info->dirty_metadata_bytes;
725 if (num_dirty < thresh)
726 return 0;
727 }
728 return extent_writepages(tree, mapping, btree_get_extent, wbc);
729 }
730
731 static int btree_readpage(struct file *file, struct page *page)
732 {
733 struct extent_io_tree *tree;
734 tree = &BTRFS_I(page->mapping->host)->io_tree;
735 return extent_read_full_page(tree, page, btree_get_extent);
736 }
737
738 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
739 {
740 struct extent_io_tree *tree;
741 struct extent_map_tree *map;
742 int ret;
743
744 if (PageWriteback(page) || PageDirty(page))
745 return 0;
746
747 tree = &BTRFS_I(page->mapping->host)->io_tree;
748 map = &BTRFS_I(page->mapping->host)->extent_tree;
749
750 ret = try_release_extent_state(map, tree, page, gfp_flags);
751 if (!ret)
752 return 0;
753
754 ret = try_release_extent_buffer(tree, page);
755 if (ret == 1) {
756 ClearPagePrivate(page);
757 set_page_private(page, 0);
758 page_cache_release(page);
759 }
760
761 return ret;
762 }
763
764 static void btree_invalidatepage(struct page *page, unsigned long offset)
765 {
766 struct extent_io_tree *tree;
767 tree = &BTRFS_I(page->mapping->host)->io_tree;
768 extent_invalidatepage(tree, page, offset);
769 btree_releasepage(page, GFP_NOFS);
770 if (PagePrivate(page)) {
771 printk(KERN_WARNING "btrfs warning page private not zero "
772 "on page %llu\n", (unsigned long long)page_offset(page));
773 ClearPagePrivate(page);
774 set_page_private(page, 0);
775 page_cache_release(page);
776 }
777 }
778
779 static const struct address_space_operations btree_aops = {
780 .readpage = btree_readpage,
781 .writepage = btree_writepage,
782 .writepages = btree_writepages,
783 .releasepage = btree_releasepage,
784 .invalidatepage = btree_invalidatepage,
785 .sync_page = block_sync_page,
786 };
787
788 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
789 u64 parent_transid)
790 {
791 struct extent_buffer *buf = NULL;
792 struct inode *btree_inode = root->fs_info->btree_inode;
793 int ret = 0;
794
795 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
796 if (!buf)
797 return 0;
798 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
799 buf, 0, 0, btree_get_extent, 0);
800 free_extent_buffer(buf);
801 return ret;
802 }
803
804 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
805 u64 bytenr, u32 blocksize)
806 {
807 struct inode *btree_inode = root->fs_info->btree_inode;
808 struct extent_buffer *eb;
809 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
810 bytenr, blocksize, GFP_NOFS);
811 return eb;
812 }
813
814 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
815 u64 bytenr, u32 blocksize)
816 {
817 struct inode *btree_inode = root->fs_info->btree_inode;
818 struct extent_buffer *eb;
819
820 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
821 bytenr, blocksize, NULL, GFP_NOFS);
822 return eb;
823 }
824
825
826 int btrfs_write_tree_block(struct extent_buffer *buf)
827 {
828 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
829 buf->start + buf->len - 1);
830 }
831
832 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
833 {
834 return filemap_fdatawait_range(buf->first_page->mapping,
835 buf->start, buf->start + buf->len - 1);
836 }
837
838 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
839 u32 blocksize, u64 parent_transid)
840 {
841 struct extent_buffer *buf = NULL;
842 struct inode *btree_inode = root->fs_info->btree_inode;
843 struct extent_io_tree *io_tree;
844 int ret;
845
846 io_tree = &BTRFS_I(btree_inode)->io_tree;
847
848 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
849 if (!buf)
850 return NULL;
851
852 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
853
854 if (ret == 0)
855 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
856 return buf;
857
858 }
859
860 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
861 struct extent_buffer *buf)
862 {
863 struct inode *btree_inode = root->fs_info->btree_inode;
864 if (btrfs_header_generation(buf) ==
865 root->fs_info->running_transaction->transid) {
866 btrfs_assert_tree_locked(buf);
867
868 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
869 spin_lock(&root->fs_info->delalloc_lock);
870 if (root->fs_info->dirty_metadata_bytes >= buf->len)
871 root->fs_info->dirty_metadata_bytes -= buf->len;
872 else
873 WARN_ON(1);
874 spin_unlock(&root->fs_info->delalloc_lock);
875 }
876
877 /* ugh, clear_extent_buffer_dirty needs to lock the page */
878 btrfs_set_lock_blocking(buf);
879 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
880 buf);
881 }
882 return 0;
883 }
884
885 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
886 u32 stripesize, struct btrfs_root *root,
887 struct btrfs_fs_info *fs_info,
888 u64 objectid)
889 {
890 root->node = NULL;
891 root->commit_root = NULL;
892 root->sectorsize = sectorsize;
893 root->nodesize = nodesize;
894 root->leafsize = leafsize;
895 root->stripesize = stripesize;
896 root->ref_cows = 0;
897 root->track_dirty = 0;
898 root->in_radix = 0;
899 root->clean_orphans = 0;
900
901 root->fs_info = fs_info;
902 root->objectid = objectid;
903 root->last_trans = 0;
904 root->highest_objectid = 0;
905 root->name = NULL;
906 root->in_sysfs = 0;
907 root->inode_tree = RB_ROOT;
908
909 INIT_LIST_HEAD(&root->dirty_list);
910 INIT_LIST_HEAD(&root->orphan_list);
911 INIT_LIST_HEAD(&root->root_list);
912 spin_lock_init(&root->node_lock);
913 spin_lock_init(&root->list_lock);
914 spin_lock_init(&root->inode_lock);
915 mutex_init(&root->objectid_mutex);
916 mutex_init(&root->log_mutex);
917 init_waitqueue_head(&root->log_writer_wait);
918 init_waitqueue_head(&root->log_commit_wait[0]);
919 init_waitqueue_head(&root->log_commit_wait[1]);
920 atomic_set(&root->log_commit[0], 0);
921 atomic_set(&root->log_commit[1], 0);
922 atomic_set(&root->log_writers, 0);
923 root->log_batch = 0;
924 root->log_transid = 0;
925 root->last_log_commit = 0;
926 extent_io_tree_init(&root->dirty_log_pages,
927 fs_info->btree_inode->i_mapping, GFP_NOFS);
928
929 memset(&root->root_key, 0, sizeof(root->root_key));
930 memset(&root->root_item, 0, sizeof(root->root_item));
931 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
932 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
933 root->defrag_trans_start = fs_info->generation;
934 init_completion(&root->kobj_unregister);
935 root->defrag_running = 0;
936 root->root_key.objectid = objectid;
937 root->anon_super.s_root = NULL;
938 root->anon_super.s_dev = 0;
939 INIT_LIST_HEAD(&root->anon_super.s_list);
940 INIT_LIST_HEAD(&root->anon_super.s_instances);
941 init_rwsem(&root->anon_super.s_umount);
942
943 return 0;
944 }
945
946 static int find_and_setup_root(struct btrfs_root *tree_root,
947 struct btrfs_fs_info *fs_info,
948 u64 objectid,
949 struct btrfs_root *root)
950 {
951 int ret;
952 u32 blocksize;
953 u64 generation;
954
955 __setup_root(tree_root->nodesize, tree_root->leafsize,
956 tree_root->sectorsize, tree_root->stripesize,
957 root, fs_info, objectid);
958 ret = btrfs_find_last_root(tree_root, objectid,
959 &root->root_item, &root->root_key);
960 if (ret > 0)
961 return -ENOENT;
962 BUG_ON(ret);
963
964 generation = btrfs_root_generation(&root->root_item);
965 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
966 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
967 blocksize, generation);
968 BUG_ON(!root->node);
969 root->commit_root = btrfs_root_node(root);
970 return 0;
971 }
972
973 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
974 struct btrfs_fs_info *fs_info)
975 {
976 struct extent_buffer *eb;
977 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
978 u64 start = 0;
979 u64 end = 0;
980 int ret;
981
982 if (!log_root_tree)
983 return 0;
984
985 while (1) {
986 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
987 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
988 if (ret)
989 break;
990
991 clear_extent_bits(&log_root_tree->dirty_log_pages, start, end,
992 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
993 }
994 eb = fs_info->log_root_tree->node;
995
996 WARN_ON(btrfs_header_level(eb) != 0);
997 WARN_ON(btrfs_header_nritems(eb) != 0);
998
999 ret = btrfs_free_reserved_extent(fs_info->tree_root,
1000 eb->start, eb->len);
1001 BUG_ON(ret);
1002
1003 free_extent_buffer(eb);
1004 kfree(fs_info->log_root_tree);
1005 fs_info->log_root_tree = NULL;
1006 return 0;
1007 }
1008
1009 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1010 struct btrfs_fs_info *fs_info)
1011 {
1012 struct btrfs_root *root;
1013 struct btrfs_root *tree_root = fs_info->tree_root;
1014 struct extent_buffer *leaf;
1015
1016 root = kzalloc(sizeof(*root), GFP_NOFS);
1017 if (!root)
1018 return ERR_PTR(-ENOMEM);
1019
1020 __setup_root(tree_root->nodesize, tree_root->leafsize,
1021 tree_root->sectorsize, tree_root->stripesize,
1022 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1023
1024 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1025 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1026 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1027 /*
1028 * log trees do not get reference counted because they go away
1029 * before a real commit is actually done. They do store pointers
1030 * to file data extents, and those reference counts still get
1031 * updated (along with back refs to the log tree).
1032 */
1033 root->ref_cows = 0;
1034
1035 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1036 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1037 if (IS_ERR(leaf)) {
1038 kfree(root);
1039 return ERR_CAST(leaf);
1040 }
1041
1042 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1043 btrfs_set_header_bytenr(leaf, leaf->start);
1044 btrfs_set_header_generation(leaf, trans->transid);
1045 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1046 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1047 root->node = leaf;
1048
1049 write_extent_buffer(root->node, root->fs_info->fsid,
1050 (unsigned long)btrfs_header_fsid(root->node),
1051 BTRFS_FSID_SIZE);
1052 btrfs_mark_buffer_dirty(root->node);
1053 btrfs_tree_unlock(root->node);
1054 return root;
1055 }
1056
1057 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1058 struct btrfs_fs_info *fs_info)
1059 {
1060 struct btrfs_root *log_root;
1061
1062 log_root = alloc_log_tree(trans, fs_info);
1063 if (IS_ERR(log_root))
1064 return PTR_ERR(log_root);
1065 WARN_ON(fs_info->log_root_tree);
1066 fs_info->log_root_tree = log_root;
1067 return 0;
1068 }
1069
1070 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1071 struct btrfs_root *root)
1072 {
1073 struct btrfs_root *log_root;
1074 struct btrfs_inode_item *inode_item;
1075
1076 log_root = alloc_log_tree(trans, root->fs_info);
1077 if (IS_ERR(log_root))
1078 return PTR_ERR(log_root);
1079
1080 log_root->last_trans = trans->transid;
1081 log_root->root_key.offset = root->root_key.objectid;
1082
1083 inode_item = &log_root->root_item.inode;
1084 inode_item->generation = cpu_to_le64(1);
1085 inode_item->size = cpu_to_le64(3);
1086 inode_item->nlink = cpu_to_le32(1);
1087 inode_item->nbytes = cpu_to_le64(root->leafsize);
1088 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1089
1090 btrfs_set_root_node(&log_root->root_item, log_root->node);
1091
1092 WARN_ON(root->log_root);
1093 root->log_root = log_root;
1094 root->log_transid = 0;
1095 root->last_log_commit = 0;
1096 return 0;
1097 }
1098
1099 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1100 struct btrfs_key *location)
1101 {
1102 struct btrfs_root *root;
1103 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1104 struct btrfs_path *path;
1105 struct extent_buffer *l;
1106 u64 generation;
1107 u32 blocksize;
1108 int ret = 0;
1109
1110 root = kzalloc(sizeof(*root), GFP_NOFS);
1111 if (!root)
1112 return ERR_PTR(-ENOMEM);
1113 if (location->offset == (u64)-1) {
1114 ret = find_and_setup_root(tree_root, fs_info,
1115 location->objectid, root);
1116 if (ret) {
1117 kfree(root);
1118 return ERR_PTR(ret);
1119 }
1120 goto out;
1121 }
1122
1123 __setup_root(tree_root->nodesize, tree_root->leafsize,
1124 tree_root->sectorsize, tree_root->stripesize,
1125 root, fs_info, location->objectid);
1126
1127 path = btrfs_alloc_path();
1128 BUG_ON(!path);
1129 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1130 if (ret == 0) {
1131 l = path->nodes[0];
1132 read_extent_buffer(l, &root->root_item,
1133 btrfs_item_ptr_offset(l, path->slots[0]),
1134 sizeof(root->root_item));
1135 memcpy(&root->root_key, location, sizeof(*location));
1136 }
1137 btrfs_free_path(path);
1138 if (ret) {
1139 if (ret > 0)
1140 ret = -ENOENT;
1141 return ERR_PTR(ret);
1142 }
1143
1144 generation = btrfs_root_generation(&root->root_item);
1145 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1146 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1147 blocksize, generation);
1148 root->commit_root = btrfs_root_node(root);
1149 BUG_ON(!root->node);
1150 out:
1151 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1152 root->ref_cows = 1;
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->name = "btrfs";
1379 bdi->capabilities = BDI_CAP_MAP_COPY;
1380 err = bdi_init(bdi);
1381 if (err)
1382 return err;
1383
1384 err = bdi_register(bdi, NULL, "btrfs-%d",
1385 atomic_inc_return(&btrfs_bdi_num));
1386 if (err) {
1387 bdi_destroy(bdi);
1388 return err;
1389 }
1390
1391 bdi->ra_pages = default_backing_dev_info.ra_pages;
1392 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1393 bdi->unplug_io_data = info;
1394 bdi->congested_fn = btrfs_congested_fn;
1395 bdi->congested_data = info;
1396 return 0;
1397 }
1398
1399 static int bio_ready_for_csum(struct bio *bio)
1400 {
1401 u64 length = 0;
1402 u64 buf_len = 0;
1403 u64 start = 0;
1404 struct page *page;
1405 struct extent_io_tree *io_tree = NULL;
1406 struct btrfs_fs_info *info = NULL;
1407 struct bio_vec *bvec;
1408 int i;
1409 int ret;
1410
1411 bio_for_each_segment(bvec, bio, i) {
1412 page = bvec->bv_page;
1413 if (page->private == EXTENT_PAGE_PRIVATE) {
1414 length += bvec->bv_len;
1415 continue;
1416 }
1417 if (!page->private) {
1418 length += bvec->bv_len;
1419 continue;
1420 }
1421 length = bvec->bv_len;
1422 buf_len = page->private >> 2;
1423 start = page_offset(page) + bvec->bv_offset;
1424 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1425 info = BTRFS_I(page->mapping->host)->root->fs_info;
1426 }
1427 /* are we fully contained in this bio? */
1428 if (buf_len <= length)
1429 return 1;
1430
1431 ret = extent_range_uptodate(io_tree, start + length,
1432 start + buf_len - 1);
1433 return ret;
1434 }
1435
1436 /*
1437 * called by the kthread helper functions to finally call the bio end_io
1438 * functions. This is where read checksum verification actually happens
1439 */
1440 static void end_workqueue_fn(struct btrfs_work *work)
1441 {
1442 struct bio *bio;
1443 struct end_io_wq *end_io_wq;
1444 struct btrfs_fs_info *fs_info;
1445 int error;
1446
1447 end_io_wq = container_of(work, struct end_io_wq, work);
1448 bio = end_io_wq->bio;
1449 fs_info = end_io_wq->info;
1450
1451 /* metadata bio reads are special because the whole tree block must
1452 * be checksummed at once. This makes sure the entire block is in
1453 * ram and up to date before trying to verify things. For
1454 * blocksize <= pagesize, it is basically a noop
1455 */
1456 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1457 !bio_ready_for_csum(bio)) {
1458 btrfs_queue_worker(&fs_info->endio_meta_workers,
1459 &end_io_wq->work);
1460 return;
1461 }
1462 error = end_io_wq->error;
1463 bio->bi_private = end_io_wq->private;
1464 bio->bi_end_io = end_io_wq->end_io;
1465 kfree(end_io_wq);
1466 bio_endio(bio, error);
1467 }
1468
1469 static int cleaner_kthread(void *arg)
1470 {
1471 struct btrfs_root *root = arg;
1472
1473 do {
1474 smp_mb();
1475 if (root->fs_info->closing)
1476 break;
1477
1478 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1479
1480 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1481 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1482 btrfs_run_delayed_iputs(root);
1483 btrfs_clean_old_snapshots(root);
1484 mutex_unlock(&root->fs_info->cleaner_mutex);
1485 }
1486
1487 if (freezing(current)) {
1488 refrigerator();
1489 } else {
1490 smp_mb();
1491 if (root->fs_info->closing)
1492 break;
1493 set_current_state(TASK_INTERRUPTIBLE);
1494 schedule();
1495 __set_current_state(TASK_RUNNING);
1496 }
1497 } while (!kthread_should_stop());
1498 return 0;
1499 }
1500
1501 static int transaction_kthread(void *arg)
1502 {
1503 struct btrfs_root *root = arg;
1504 struct btrfs_trans_handle *trans;
1505 struct btrfs_transaction *cur;
1506 unsigned long now;
1507 unsigned long delay;
1508 int ret;
1509
1510 do {
1511 smp_mb();
1512 if (root->fs_info->closing)
1513 break;
1514
1515 delay = HZ * 30;
1516 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1517 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1518
1519 mutex_lock(&root->fs_info->trans_mutex);
1520 cur = root->fs_info->running_transaction;
1521 if (!cur) {
1522 mutex_unlock(&root->fs_info->trans_mutex);
1523 goto sleep;
1524 }
1525
1526 now = get_seconds();
1527 if (now < cur->start_time || now - cur->start_time < 30) {
1528 mutex_unlock(&root->fs_info->trans_mutex);
1529 delay = HZ * 5;
1530 goto sleep;
1531 }
1532 mutex_unlock(&root->fs_info->trans_mutex);
1533 trans = btrfs_start_transaction(root, 1);
1534 ret = btrfs_commit_transaction(trans, root);
1535
1536 sleep:
1537 wake_up_process(root->fs_info->cleaner_kthread);
1538 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1539
1540 if (freezing(current)) {
1541 refrigerator();
1542 } else {
1543 if (root->fs_info->closing)
1544 break;
1545 set_current_state(TASK_INTERRUPTIBLE);
1546 schedule_timeout(delay);
1547 __set_current_state(TASK_RUNNING);
1548 }
1549 } while (!kthread_should_stop());
1550 return 0;
1551 }
1552
1553 struct btrfs_root *open_ctree(struct super_block *sb,
1554 struct btrfs_fs_devices *fs_devices,
1555 char *options)
1556 {
1557 u32 sectorsize;
1558 u32 nodesize;
1559 u32 leafsize;
1560 u32 blocksize;
1561 u32 stripesize;
1562 u64 generation;
1563 u64 features;
1564 struct btrfs_key location;
1565 struct buffer_head *bh;
1566 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1567 GFP_NOFS);
1568 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1569 GFP_NOFS);
1570 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1571 GFP_NOFS);
1572 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1573 GFP_NOFS);
1574 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1575 GFP_NOFS);
1576 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1577 GFP_NOFS);
1578 struct btrfs_root *log_tree_root;
1579
1580 int ret;
1581 int err = -EINVAL;
1582
1583 struct btrfs_super_block *disk_super;
1584
1585 if (!extent_root || !tree_root || !fs_info ||
1586 !chunk_root || !dev_root || !csum_root) {
1587 err = -ENOMEM;
1588 goto fail;
1589 }
1590
1591 ret = init_srcu_struct(&fs_info->subvol_srcu);
1592 if (ret) {
1593 err = ret;
1594 goto fail;
1595 }
1596
1597 ret = setup_bdi(fs_info, &fs_info->bdi);
1598 if (ret) {
1599 err = ret;
1600 goto fail_srcu;
1601 }
1602
1603 fs_info->btree_inode = new_inode(sb);
1604 if (!fs_info->btree_inode) {
1605 err = -ENOMEM;
1606 goto fail_bdi;
1607 }
1608
1609 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1610 INIT_LIST_HEAD(&fs_info->trans_list);
1611 INIT_LIST_HEAD(&fs_info->dead_roots);
1612 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1613 INIT_LIST_HEAD(&fs_info->hashers);
1614 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1615 INIT_LIST_HEAD(&fs_info->ordered_operations);
1616 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1617 spin_lock_init(&fs_info->delalloc_lock);
1618 spin_lock_init(&fs_info->new_trans_lock);
1619 spin_lock_init(&fs_info->ref_cache_lock);
1620 spin_lock_init(&fs_info->fs_roots_radix_lock);
1621 spin_lock_init(&fs_info->delayed_iput_lock);
1622
1623 init_completion(&fs_info->kobj_unregister);
1624 fs_info->tree_root = tree_root;
1625 fs_info->extent_root = extent_root;
1626 fs_info->csum_root = csum_root;
1627 fs_info->chunk_root = chunk_root;
1628 fs_info->dev_root = dev_root;
1629 fs_info->fs_devices = fs_devices;
1630 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1631 INIT_LIST_HEAD(&fs_info->space_info);
1632 btrfs_mapping_init(&fs_info->mapping_tree);
1633 atomic_set(&fs_info->nr_async_submits, 0);
1634 atomic_set(&fs_info->async_delalloc_pages, 0);
1635 atomic_set(&fs_info->async_submit_draining, 0);
1636 atomic_set(&fs_info->nr_async_bios, 0);
1637 fs_info->sb = sb;
1638 fs_info->max_extent = (u64)-1;
1639 fs_info->max_inline = 8192 * 1024;
1640 fs_info->metadata_ratio = 0;
1641
1642 fs_info->thread_pool_size = min_t(unsigned long,
1643 num_online_cpus() + 2, 8);
1644
1645 INIT_LIST_HEAD(&fs_info->ordered_extents);
1646 spin_lock_init(&fs_info->ordered_extent_lock);
1647
1648 sb->s_blocksize = 4096;
1649 sb->s_blocksize_bits = blksize_bits(4096);
1650 sb->s_bdi = &fs_info->bdi;
1651
1652 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1653 fs_info->btree_inode->i_nlink = 1;
1654 /*
1655 * we set the i_size on the btree inode to the max possible int.
1656 * the real end of the address space is determined by all of
1657 * the devices in the system
1658 */
1659 fs_info->btree_inode->i_size = OFFSET_MAX;
1660 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1661 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1662
1663 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1664 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1665 fs_info->btree_inode->i_mapping,
1666 GFP_NOFS);
1667 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1668 GFP_NOFS);
1669
1670 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1671
1672 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1673 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1674 sizeof(struct btrfs_key));
1675 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1676 insert_inode_hash(fs_info->btree_inode);
1677
1678 spin_lock_init(&fs_info->block_group_cache_lock);
1679 fs_info->block_group_cache_tree = RB_ROOT;
1680
1681 extent_io_tree_init(&fs_info->freed_extents[0],
1682 fs_info->btree_inode->i_mapping, GFP_NOFS);
1683 extent_io_tree_init(&fs_info->freed_extents[1],
1684 fs_info->btree_inode->i_mapping, GFP_NOFS);
1685 fs_info->pinned_extents = &fs_info->freed_extents[0];
1686 fs_info->do_barriers = 1;
1687
1688
1689 mutex_init(&fs_info->trans_mutex);
1690 mutex_init(&fs_info->ordered_operations_mutex);
1691 mutex_init(&fs_info->tree_log_mutex);
1692 mutex_init(&fs_info->chunk_mutex);
1693 mutex_init(&fs_info->transaction_kthread_mutex);
1694 mutex_init(&fs_info->cleaner_mutex);
1695 mutex_init(&fs_info->volume_mutex);
1696 init_rwsem(&fs_info->extent_commit_sem);
1697 init_rwsem(&fs_info->cleanup_work_sem);
1698 init_rwsem(&fs_info->subvol_sem);
1699
1700 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1701 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1702
1703 init_waitqueue_head(&fs_info->transaction_throttle);
1704 init_waitqueue_head(&fs_info->transaction_wait);
1705 init_waitqueue_head(&fs_info->async_submit_wait);
1706
1707 __setup_root(4096, 4096, 4096, 4096, tree_root,
1708 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1709
1710
1711 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1712 if (!bh)
1713 goto fail_iput;
1714
1715 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1716 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1717 sizeof(fs_info->super_for_commit));
1718 brelse(bh);
1719
1720 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1721
1722 disk_super = &fs_info->super_copy;
1723 if (!btrfs_super_root(disk_super))
1724 goto fail_iput;
1725
1726 ret = btrfs_parse_options(tree_root, options);
1727 if (ret) {
1728 err = ret;
1729 goto fail_iput;
1730 }
1731
1732 features = btrfs_super_incompat_flags(disk_super) &
1733 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1734 if (features) {
1735 printk(KERN_ERR "BTRFS: couldn't mount because of "
1736 "unsupported optional features (%Lx).\n",
1737 (unsigned long long)features);
1738 err = -EINVAL;
1739 goto fail_iput;
1740 }
1741
1742 features = btrfs_super_incompat_flags(disk_super);
1743 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1744 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1745 btrfs_set_super_incompat_flags(disk_super, features);
1746 }
1747
1748 features = btrfs_super_compat_ro_flags(disk_super) &
1749 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1750 if (!(sb->s_flags & MS_RDONLY) && features) {
1751 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1752 "unsupported option features (%Lx).\n",
1753 (unsigned long long)features);
1754 err = -EINVAL;
1755 goto fail_iput;
1756 }
1757
1758 btrfs_init_workers(&fs_info->generic_worker,
1759 "genwork", 1, NULL);
1760
1761 btrfs_init_workers(&fs_info->workers, "worker",
1762 fs_info->thread_pool_size,
1763 &fs_info->generic_worker);
1764
1765 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1766 fs_info->thread_pool_size,
1767 &fs_info->generic_worker);
1768
1769 btrfs_init_workers(&fs_info->submit_workers, "submit",
1770 min_t(u64, fs_devices->num_devices,
1771 fs_info->thread_pool_size),
1772 &fs_info->generic_worker);
1773 btrfs_init_workers(&fs_info->enospc_workers, "enospc",
1774 fs_info->thread_pool_size,
1775 &fs_info->generic_worker);
1776
1777 /* a higher idle thresh on the submit workers makes it much more
1778 * likely that bios will be send down in a sane order to the
1779 * devices
1780 */
1781 fs_info->submit_workers.idle_thresh = 64;
1782
1783 fs_info->workers.idle_thresh = 16;
1784 fs_info->workers.ordered = 1;
1785
1786 fs_info->delalloc_workers.idle_thresh = 2;
1787 fs_info->delalloc_workers.ordered = 1;
1788
1789 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1790 &fs_info->generic_worker);
1791 btrfs_init_workers(&fs_info->endio_workers, "endio",
1792 fs_info->thread_pool_size,
1793 &fs_info->generic_worker);
1794 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1795 fs_info->thread_pool_size,
1796 &fs_info->generic_worker);
1797 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1798 "endio-meta-write", fs_info->thread_pool_size,
1799 &fs_info->generic_worker);
1800 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1801 fs_info->thread_pool_size,
1802 &fs_info->generic_worker);
1803
1804 /*
1805 * endios are largely parallel and should have a very
1806 * low idle thresh
1807 */
1808 fs_info->endio_workers.idle_thresh = 4;
1809 fs_info->endio_meta_workers.idle_thresh = 4;
1810
1811 fs_info->endio_write_workers.idle_thresh = 2;
1812 fs_info->endio_meta_write_workers.idle_thresh = 2;
1813
1814 btrfs_start_workers(&fs_info->workers, 1);
1815 btrfs_start_workers(&fs_info->generic_worker, 1);
1816 btrfs_start_workers(&fs_info->submit_workers, 1);
1817 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1818 btrfs_start_workers(&fs_info->fixup_workers, 1);
1819 btrfs_start_workers(&fs_info->endio_workers, 1);
1820 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1821 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1822 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1823 btrfs_start_workers(&fs_info->enospc_workers, 1);
1824
1825 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1826 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1827 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1828
1829 nodesize = btrfs_super_nodesize(disk_super);
1830 leafsize = btrfs_super_leafsize(disk_super);
1831 sectorsize = btrfs_super_sectorsize(disk_super);
1832 stripesize = btrfs_super_stripesize(disk_super);
1833 tree_root->nodesize = nodesize;
1834 tree_root->leafsize = leafsize;
1835 tree_root->sectorsize = sectorsize;
1836 tree_root->stripesize = stripesize;
1837
1838 sb->s_blocksize = sectorsize;
1839 sb->s_blocksize_bits = blksize_bits(sectorsize);
1840
1841 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1842 sizeof(disk_super->magic))) {
1843 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1844 goto fail_sb_buffer;
1845 }
1846
1847 mutex_lock(&fs_info->chunk_mutex);
1848 ret = btrfs_read_sys_array(tree_root);
1849 mutex_unlock(&fs_info->chunk_mutex);
1850 if (ret) {
1851 printk(KERN_WARNING "btrfs: failed to read the system "
1852 "array on %s\n", sb->s_id);
1853 goto fail_sb_buffer;
1854 }
1855
1856 blocksize = btrfs_level_size(tree_root,
1857 btrfs_super_chunk_root_level(disk_super));
1858 generation = btrfs_super_chunk_root_generation(disk_super);
1859
1860 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1861 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1862
1863 chunk_root->node = read_tree_block(chunk_root,
1864 btrfs_super_chunk_root(disk_super),
1865 blocksize, generation);
1866 BUG_ON(!chunk_root->node);
1867 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1868 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1869 sb->s_id);
1870 goto fail_chunk_root;
1871 }
1872 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1873 chunk_root->commit_root = btrfs_root_node(chunk_root);
1874
1875 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1876 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1877 BTRFS_UUID_SIZE);
1878
1879 mutex_lock(&fs_info->chunk_mutex);
1880 ret = btrfs_read_chunk_tree(chunk_root);
1881 mutex_unlock(&fs_info->chunk_mutex);
1882 if (ret) {
1883 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1884 sb->s_id);
1885 goto fail_chunk_root;
1886 }
1887
1888 btrfs_close_extra_devices(fs_devices);
1889
1890 blocksize = btrfs_level_size(tree_root,
1891 btrfs_super_root_level(disk_super));
1892 generation = btrfs_super_generation(disk_super);
1893
1894 tree_root->node = read_tree_block(tree_root,
1895 btrfs_super_root(disk_super),
1896 blocksize, generation);
1897 if (!tree_root->node)
1898 goto fail_chunk_root;
1899 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1900 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1901 sb->s_id);
1902 goto fail_tree_root;
1903 }
1904 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1905 tree_root->commit_root = btrfs_root_node(tree_root);
1906
1907 ret = find_and_setup_root(tree_root, fs_info,
1908 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1909 if (ret)
1910 goto fail_tree_root;
1911 extent_root->track_dirty = 1;
1912
1913 ret = find_and_setup_root(tree_root, fs_info,
1914 BTRFS_DEV_TREE_OBJECTID, dev_root);
1915 if (ret)
1916 goto fail_extent_root;
1917 dev_root->track_dirty = 1;
1918
1919 ret = find_and_setup_root(tree_root, fs_info,
1920 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1921 if (ret)
1922 goto fail_dev_root;
1923
1924 csum_root->track_dirty = 1;
1925
1926 btrfs_read_block_groups(extent_root);
1927
1928 fs_info->generation = generation;
1929 fs_info->last_trans_committed = generation;
1930 fs_info->data_alloc_profile = (u64)-1;
1931 fs_info->metadata_alloc_profile = (u64)-1;
1932 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1933 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1934 "btrfs-cleaner");
1935 if (IS_ERR(fs_info->cleaner_kthread))
1936 goto fail_csum_root;
1937
1938 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1939 tree_root,
1940 "btrfs-transaction");
1941 if (IS_ERR(fs_info->transaction_kthread))
1942 goto fail_cleaner;
1943
1944 if (!btrfs_test_opt(tree_root, SSD) &&
1945 !btrfs_test_opt(tree_root, NOSSD) &&
1946 !fs_info->fs_devices->rotating) {
1947 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1948 "mode\n");
1949 btrfs_set_opt(fs_info->mount_opt, SSD);
1950 }
1951
1952 if (btrfs_super_log_root(disk_super) != 0) {
1953 u64 bytenr = btrfs_super_log_root(disk_super);
1954
1955 if (fs_devices->rw_devices == 0) {
1956 printk(KERN_WARNING "Btrfs log replay required "
1957 "on RO media\n");
1958 err = -EIO;
1959 goto fail_trans_kthread;
1960 }
1961 blocksize =
1962 btrfs_level_size(tree_root,
1963 btrfs_super_log_root_level(disk_super));
1964
1965 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1966 GFP_NOFS);
1967
1968 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1969 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1970
1971 log_tree_root->node = read_tree_block(tree_root, bytenr,
1972 blocksize,
1973 generation + 1);
1974 ret = btrfs_recover_log_trees(log_tree_root);
1975 BUG_ON(ret);
1976
1977 if (sb->s_flags & MS_RDONLY) {
1978 ret = btrfs_commit_super(tree_root);
1979 BUG_ON(ret);
1980 }
1981 }
1982
1983 ret = btrfs_find_orphan_roots(tree_root);
1984 BUG_ON(ret);
1985
1986 if (!(sb->s_flags & MS_RDONLY)) {
1987 ret = btrfs_recover_relocation(tree_root);
1988 if (ret < 0) {
1989 printk(KERN_WARNING
1990 "btrfs: failed to recover relocation\n");
1991 err = -EINVAL;
1992 goto fail_trans_kthread;
1993 }
1994 }
1995
1996 location.objectid = BTRFS_FS_TREE_OBJECTID;
1997 location.type = BTRFS_ROOT_ITEM_KEY;
1998 location.offset = (u64)-1;
1999
2000 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2001 if (!fs_info->fs_root)
2002 goto fail_trans_kthread;
2003
2004 if (!(sb->s_flags & MS_RDONLY)) {
2005 down_read(&fs_info->cleanup_work_sem);
2006 btrfs_orphan_cleanup(fs_info->fs_root);
2007 up_read(&fs_info->cleanup_work_sem);
2008 }
2009
2010 return tree_root;
2011
2012 fail_trans_kthread:
2013 kthread_stop(fs_info->transaction_kthread);
2014 fail_cleaner:
2015 kthread_stop(fs_info->cleaner_kthread);
2016
2017 /*
2018 * make sure we're done with the btree inode before we stop our
2019 * kthreads
2020 */
2021 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2022 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2023
2024 fail_csum_root:
2025 free_extent_buffer(csum_root->node);
2026 free_extent_buffer(csum_root->commit_root);
2027 fail_dev_root:
2028 free_extent_buffer(dev_root->node);
2029 free_extent_buffer(dev_root->commit_root);
2030 fail_extent_root:
2031 free_extent_buffer(extent_root->node);
2032 free_extent_buffer(extent_root->commit_root);
2033 fail_tree_root:
2034 free_extent_buffer(tree_root->node);
2035 free_extent_buffer(tree_root->commit_root);
2036 fail_chunk_root:
2037 free_extent_buffer(chunk_root->node);
2038 free_extent_buffer(chunk_root->commit_root);
2039 fail_sb_buffer:
2040 btrfs_stop_workers(&fs_info->generic_worker);
2041 btrfs_stop_workers(&fs_info->fixup_workers);
2042 btrfs_stop_workers(&fs_info->delalloc_workers);
2043 btrfs_stop_workers(&fs_info->workers);
2044 btrfs_stop_workers(&fs_info->endio_workers);
2045 btrfs_stop_workers(&fs_info->endio_meta_workers);
2046 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2047 btrfs_stop_workers(&fs_info->endio_write_workers);
2048 btrfs_stop_workers(&fs_info->submit_workers);
2049 btrfs_stop_workers(&fs_info->enospc_workers);
2050 fail_iput:
2051 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2052 iput(fs_info->btree_inode);
2053
2054 btrfs_close_devices(fs_info->fs_devices);
2055 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2056 fail_bdi:
2057 bdi_destroy(&fs_info->bdi);
2058 fail_srcu:
2059 cleanup_srcu_struct(&fs_info->subvol_srcu);
2060 fail:
2061 kfree(extent_root);
2062 kfree(tree_root);
2063 kfree(fs_info);
2064 kfree(chunk_root);
2065 kfree(dev_root);
2066 kfree(csum_root);
2067 return ERR_PTR(err);
2068 }
2069
2070 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2071 {
2072 char b[BDEVNAME_SIZE];
2073
2074 if (uptodate) {
2075 set_buffer_uptodate(bh);
2076 } else {
2077 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
2078 printk(KERN_WARNING "lost page write due to "
2079 "I/O error on %s\n",
2080 bdevname(bh->b_bdev, b));
2081 }
2082 /* note, we dont' set_buffer_write_io_error because we have
2083 * our own ways of dealing with the IO errors
2084 */
2085 clear_buffer_uptodate(bh);
2086 }
2087 unlock_buffer(bh);
2088 put_bh(bh);
2089 }
2090
2091 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2092 {
2093 struct buffer_head *bh;
2094 struct buffer_head *latest = NULL;
2095 struct btrfs_super_block *super;
2096 int i;
2097 u64 transid = 0;
2098 u64 bytenr;
2099
2100 /* we would like to check all the supers, but that would make
2101 * a btrfs mount succeed after a mkfs from a different FS.
2102 * So, we need to add a special mount option to scan for
2103 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2104 */
2105 for (i = 0; i < 1; i++) {
2106 bytenr = btrfs_sb_offset(i);
2107 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2108 break;
2109 bh = __bread(bdev, bytenr / 4096, 4096);
2110 if (!bh)
2111 continue;
2112
2113 super = (struct btrfs_super_block *)bh->b_data;
2114 if (btrfs_super_bytenr(super) != bytenr ||
2115 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2116 sizeof(super->magic))) {
2117 brelse(bh);
2118 continue;
2119 }
2120
2121 if (!latest || btrfs_super_generation(super) > transid) {
2122 brelse(latest);
2123 latest = bh;
2124 transid = btrfs_super_generation(super);
2125 } else {
2126 brelse(bh);
2127 }
2128 }
2129 return latest;
2130 }
2131
2132 /*
2133 * this should be called twice, once with wait == 0 and
2134 * once with wait == 1. When wait == 0 is done, all the buffer heads
2135 * we write are pinned.
2136 *
2137 * They are released when wait == 1 is done.
2138 * max_mirrors must be the same for both runs, and it indicates how
2139 * many supers on this one device should be written.
2140 *
2141 * max_mirrors == 0 means to write them all.
2142 */
2143 static int write_dev_supers(struct btrfs_device *device,
2144 struct btrfs_super_block *sb,
2145 int do_barriers, int wait, int max_mirrors)
2146 {
2147 struct buffer_head *bh;
2148 int i;
2149 int ret;
2150 int errors = 0;
2151 u32 crc;
2152 u64 bytenr;
2153 int last_barrier = 0;
2154
2155 if (max_mirrors == 0)
2156 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2157
2158 /* make sure only the last submit_bh does a barrier */
2159 if (do_barriers) {
2160 for (i = 0; i < max_mirrors; i++) {
2161 bytenr = btrfs_sb_offset(i);
2162 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2163 device->total_bytes)
2164 break;
2165 last_barrier = i;
2166 }
2167 }
2168
2169 for (i = 0; i < max_mirrors; i++) {
2170 bytenr = btrfs_sb_offset(i);
2171 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2172 break;
2173
2174 if (wait) {
2175 bh = __find_get_block(device->bdev, bytenr / 4096,
2176 BTRFS_SUPER_INFO_SIZE);
2177 BUG_ON(!bh);
2178 wait_on_buffer(bh);
2179 if (!buffer_uptodate(bh))
2180 errors++;
2181
2182 /* drop our reference */
2183 brelse(bh);
2184
2185 /* drop the reference from the wait == 0 run */
2186 brelse(bh);
2187 continue;
2188 } else {
2189 btrfs_set_super_bytenr(sb, bytenr);
2190
2191 crc = ~(u32)0;
2192 crc = btrfs_csum_data(NULL, (char *)sb +
2193 BTRFS_CSUM_SIZE, crc,
2194 BTRFS_SUPER_INFO_SIZE -
2195 BTRFS_CSUM_SIZE);
2196 btrfs_csum_final(crc, sb->csum);
2197
2198 /*
2199 * one reference for us, and we leave it for the
2200 * caller
2201 */
2202 bh = __getblk(device->bdev, bytenr / 4096,
2203 BTRFS_SUPER_INFO_SIZE);
2204 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2205
2206 /* one reference for submit_bh */
2207 get_bh(bh);
2208
2209 set_buffer_uptodate(bh);
2210 lock_buffer(bh);
2211 bh->b_end_io = btrfs_end_buffer_write_sync;
2212 }
2213
2214 if (i == last_barrier && do_barriers && device->barriers) {
2215 ret = submit_bh(WRITE_BARRIER, bh);
2216 if (ret == -EOPNOTSUPP) {
2217 printk("btrfs: disabling barriers on dev %s\n",
2218 device->name);
2219 set_buffer_uptodate(bh);
2220 device->barriers = 0;
2221 /* one reference for submit_bh */
2222 get_bh(bh);
2223 lock_buffer(bh);
2224 ret = submit_bh(WRITE_SYNC, bh);
2225 }
2226 } else {
2227 ret = submit_bh(WRITE_SYNC, bh);
2228 }
2229
2230 if (ret)
2231 errors++;
2232 }
2233 return errors < i ? 0 : -1;
2234 }
2235
2236 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2237 {
2238 struct list_head *head;
2239 struct btrfs_device *dev;
2240 struct btrfs_super_block *sb;
2241 struct btrfs_dev_item *dev_item;
2242 int ret;
2243 int do_barriers;
2244 int max_errors;
2245 int total_errors = 0;
2246 u64 flags;
2247
2248 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2249 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2250
2251 sb = &root->fs_info->super_for_commit;
2252 dev_item = &sb->dev_item;
2253
2254 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2255 head = &root->fs_info->fs_devices->devices;
2256 list_for_each_entry(dev, head, dev_list) {
2257 if (!dev->bdev) {
2258 total_errors++;
2259 continue;
2260 }
2261 if (!dev->in_fs_metadata || !dev->writeable)
2262 continue;
2263
2264 btrfs_set_stack_device_generation(dev_item, 0);
2265 btrfs_set_stack_device_type(dev_item, dev->type);
2266 btrfs_set_stack_device_id(dev_item, dev->devid);
2267 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2268 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2269 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2270 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2271 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2272 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2273 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2274
2275 flags = btrfs_super_flags(sb);
2276 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2277
2278 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2279 if (ret)
2280 total_errors++;
2281 }
2282 if (total_errors > max_errors) {
2283 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2284 total_errors);
2285 BUG();
2286 }
2287
2288 total_errors = 0;
2289 list_for_each_entry(dev, head, dev_list) {
2290 if (!dev->bdev)
2291 continue;
2292 if (!dev->in_fs_metadata || !dev->writeable)
2293 continue;
2294
2295 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2296 if (ret)
2297 total_errors++;
2298 }
2299 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2300 if (total_errors > max_errors) {
2301 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2302 total_errors);
2303 BUG();
2304 }
2305 return 0;
2306 }
2307
2308 int write_ctree_super(struct btrfs_trans_handle *trans,
2309 struct btrfs_root *root, int max_mirrors)
2310 {
2311 int ret;
2312
2313 ret = write_all_supers(root, max_mirrors);
2314 return ret;
2315 }
2316
2317 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2318 {
2319 spin_lock(&fs_info->fs_roots_radix_lock);
2320 radix_tree_delete(&fs_info->fs_roots_radix,
2321 (unsigned long)root->root_key.objectid);
2322 spin_unlock(&fs_info->fs_roots_radix_lock);
2323
2324 if (btrfs_root_refs(&root->root_item) == 0)
2325 synchronize_srcu(&fs_info->subvol_srcu);
2326
2327 free_fs_root(root);
2328 return 0;
2329 }
2330
2331 static void free_fs_root(struct btrfs_root *root)
2332 {
2333 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2334 if (root->anon_super.s_dev) {
2335 down_write(&root->anon_super.s_umount);
2336 kill_anon_super(&root->anon_super);
2337 }
2338 free_extent_buffer(root->node);
2339 free_extent_buffer(root->commit_root);
2340 kfree(root->name);
2341 kfree(root);
2342 }
2343
2344 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2345 {
2346 int ret;
2347 struct btrfs_root *gang[8];
2348 int i;
2349
2350 while (!list_empty(&fs_info->dead_roots)) {
2351 gang[0] = list_entry(fs_info->dead_roots.next,
2352 struct btrfs_root, root_list);
2353 list_del(&gang[0]->root_list);
2354
2355 if (gang[0]->in_radix) {
2356 btrfs_free_fs_root(fs_info, gang[0]);
2357 } else {
2358 free_extent_buffer(gang[0]->node);
2359 free_extent_buffer(gang[0]->commit_root);
2360 kfree(gang[0]);
2361 }
2362 }
2363
2364 while (1) {
2365 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2366 (void **)gang, 0,
2367 ARRAY_SIZE(gang));
2368 if (!ret)
2369 break;
2370 for (i = 0; i < ret; i++)
2371 btrfs_free_fs_root(fs_info, gang[i]);
2372 }
2373 return 0;
2374 }
2375
2376 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2377 {
2378 u64 root_objectid = 0;
2379 struct btrfs_root *gang[8];
2380 int i;
2381 int ret;
2382
2383 while (1) {
2384 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2385 (void **)gang, root_objectid,
2386 ARRAY_SIZE(gang));
2387 if (!ret)
2388 break;
2389
2390 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2391 for (i = 0; i < ret; i++) {
2392 root_objectid = gang[i]->root_key.objectid;
2393 btrfs_orphan_cleanup(gang[i]);
2394 }
2395 root_objectid++;
2396 }
2397 return 0;
2398 }
2399
2400 int btrfs_commit_super(struct btrfs_root *root)
2401 {
2402 struct btrfs_trans_handle *trans;
2403 int ret;
2404
2405 mutex_lock(&root->fs_info->cleaner_mutex);
2406 btrfs_run_delayed_iputs(root);
2407 btrfs_clean_old_snapshots(root);
2408 mutex_unlock(&root->fs_info->cleaner_mutex);
2409
2410 /* wait until ongoing cleanup work done */
2411 down_write(&root->fs_info->cleanup_work_sem);
2412 up_write(&root->fs_info->cleanup_work_sem);
2413
2414 trans = btrfs_start_transaction(root, 1);
2415 ret = btrfs_commit_transaction(trans, root);
2416 BUG_ON(ret);
2417 /* run commit again to drop the original snapshot */
2418 trans = btrfs_start_transaction(root, 1);
2419 btrfs_commit_transaction(trans, root);
2420 ret = btrfs_write_and_wait_transaction(NULL, root);
2421 BUG_ON(ret);
2422
2423 ret = write_ctree_super(NULL, root, 0);
2424 return ret;
2425 }
2426
2427 int close_ctree(struct btrfs_root *root)
2428 {
2429 struct btrfs_fs_info *fs_info = root->fs_info;
2430 int ret;
2431
2432 fs_info->closing = 1;
2433 smp_mb();
2434
2435 kthread_stop(root->fs_info->transaction_kthread);
2436 kthread_stop(root->fs_info->cleaner_kthread);
2437
2438 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2439 ret = btrfs_commit_super(root);
2440 if (ret)
2441 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2442 }
2443
2444 fs_info->closing = 2;
2445 smp_mb();
2446
2447 if (fs_info->delalloc_bytes) {
2448 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2449 (unsigned long long)fs_info->delalloc_bytes);
2450 }
2451 if (fs_info->total_ref_cache_size) {
2452 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2453 (unsigned long long)fs_info->total_ref_cache_size);
2454 }
2455
2456 free_extent_buffer(fs_info->extent_root->node);
2457 free_extent_buffer(fs_info->extent_root->commit_root);
2458 free_extent_buffer(fs_info->tree_root->node);
2459 free_extent_buffer(fs_info->tree_root->commit_root);
2460 free_extent_buffer(root->fs_info->chunk_root->node);
2461 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2462 free_extent_buffer(root->fs_info->dev_root->node);
2463 free_extent_buffer(root->fs_info->dev_root->commit_root);
2464 free_extent_buffer(root->fs_info->csum_root->node);
2465 free_extent_buffer(root->fs_info->csum_root->commit_root);
2466
2467 btrfs_free_block_groups(root->fs_info);
2468
2469 del_fs_roots(fs_info);
2470
2471 iput(fs_info->btree_inode);
2472
2473 btrfs_stop_workers(&fs_info->generic_worker);
2474 btrfs_stop_workers(&fs_info->fixup_workers);
2475 btrfs_stop_workers(&fs_info->delalloc_workers);
2476 btrfs_stop_workers(&fs_info->workers);
2477 btrfs_stop_workers(&fs_info->endio_workers);
2478 btrfs_stop_workers(&fs_info->endio_meta_workers);
2479 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2480 btrfs_stop_workers(&fs_info->endio_write_workers);
2481 btrfs_stop_workers(&fs_info->submit_workers);
2482 btrfs_stop_workers(&fs_info->enospc_workers);
2483
2484 btrfs_close_devices(fs_info->fs_devices);
2485 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2486
2487 bdi_destroy(&fs_info->bdi);
2488 cleanup_srcu_struct(&fs_info->subvol_srcu);
2489
2490 kfree(fs_info->extent_root);
2491 kfree(fs_info->tree_root);
2492 kfree(fs_info->chunk_root);
2493 kfree(fs_info->dev_root);
2494 kfree(fs_info->csum_root);
2495 return 0;
2496 }
2497
2498 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2499 {
2500 int ret;
2501 struct inode *btree_inode = buf->first_page->mapping->host;
2502
2503 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2504 NULL);
2505 if (!ret)
2506 return ret;
2507
2508 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2509 parent_transid);
2510 return !ret;
2511 }
2512
2513 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2514 {
2515 struct inode *btree_inode = buf->first_page->mapping->host;
2516 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2517 buf);
2518 }
2519
2520 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2521 {
2522 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2523 u64 transid = btrfs_header_generation(buf);
2524 struct inode *btree_inode = root->fs_info->btree_inode;
2525 int was_dirty;
2526
2527 btrfs_assert_tree_locked(buf);
2528 if (transid != root->fs_info->generation) {
2529 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2530 "found %llu running %llu\n",
2531 (unsigned long long)buf->start,
2532 (unsigned long long)transid,
2533 (unsigned long long)root->fs_info->generation);
2534 WARN_ON(1);
2535 }
2536 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2537 buf);
2538 if (!was_dirty) {
2539 spin_lock(&root->fs_info->delalloc_lock);
2540 root->fs_info->dirty_metadata_bytes += buf->len;
2541 spin_unlock(&root->fs_info->delalloc_lock);
2542 }
2543 }
2544
2545 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2546 {
2547 /*
2548 * looks as though older kernels can get into trouble with
2549 * this code, they end up stuck in balance_dirty_pages forever
2550 */
2551 u64 num_dirty;
2552 unsigned long thresh = 32 * 1024 * 1024;
2553
2554 if (current->flags & PF_MEMALLOC)
2555 return;
2556
2557 num_dirty = root->fs_info->dirty_metadata_bytes;
2558
2559 if (num_dirty > thresh) {
2560 balance_dirty_pages_ratelimited_nr(
2561 root->fs_info->btree_inode->i_mapping, 1);
2562 }
2563 return;
2564 }
2565
2566 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2567 {
2568 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2569 int ret;
2570 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2571 if (ret == 0)
2572 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2573 return ret;
2574 }
2575
2576 int btree_lock_page_hook(struct page *page)
2577 {
2578 struct inode *inode = page->mapping->host;
2579 struct btrfs_root *root = BTRFS_I(inode)->root;
2580 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2581 struct extent_buffer *eb;
2582 unsigned long len;
2583 u64 bytenr = page_offset(page);
2584
2585 if (page->private == EXTENT_PAGE_PRIVATE)
2586 goto out;
2587
2588 len = page->private >> 2;
2589 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2590 if (!eb)
2591 goto out;
2592
2593 btrfs_tree_lock(eb);
2594 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2595
2596 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2597 spin_lock(&root->fs_info->delalloc_lock);
2598 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2599 root->fs_info->dirty_metadata_bytes -= eb->len;
2600 else
2601 WARN_ON(1);
2602 spin_unlock(&root->fs_info->delalloc_lock);
2603 }
2604
2605 btrfs_tree_unlock(eb);
2606 free_extent_buffer(eb);
2607 out:
2608 lock_page(page);
2609 return 0;
2610 }
2611
2612 static struct extent_io_ops btree_extent_io_ops = {
2613 .write_cache_pages_lock_hook = btree_lock_page_hook,
2614 .readpage_end_io_hook = btree_readpage_end_io_hook,
2615 .submit_bio_hook = btree_submit_bio_hook,
2616 /* note we're sharing with inode.c for the merge bio hook */
2617 .merge_bio_hook = btrfs_merge_bio_hook,
2618 };
kernel source for telekom puls (alcatel/mediatek)