projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[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 <linux/migrate.h>
32 #include "compat.h"
33 #include "ctree.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "btrfs_inode.h"
37 #include "volumes.h"
38 #include "print-tree.h"
39 #include "async-thread.h"
40 #include "locking.h"
41 #include "tree-log.h"
42 #include "free-space-cache.h"
43
44 static struct extent_io_ops btree_extent_io_ops;
45 static void end_workqueue_fn(struct btrfs_work *work);
46 static void free_fs_root(struct btrfs_root *root);
47
48 /*
49 * end_io_wq structs are used to do processing in task context when an IO is
50 * complete. This is used during reads to verify checksums, and it is used
51 * by writes to insert metadata for new file extents after IO is complete.
52 */
53 struct end_io_wq {
54 struct bio *bio;
55 bio_end_io_t *end_io;
56 void *private;
57 struct btrfs_fs_info *info;
58 int error;
59 int metadata;
60 struct list_head list;
61 struct btrfs_work work;
62 };
63
64 /*
65 * async submit bios are used to offload expensive checksumming
66 * onto the worker threads. They checksum file and metadata bios
67 * just before they are sent down the IO stack.
68 */
69 struct async_submit_bio {
70 struct inode *inode;
71 struct bio *bio;
72 struct list_head list;
73 extent_submit_bio_hook_t *submit_bio_start;
74 extent_submit_bio_hook_t *submit_bio_done;
75 int rw;
76 int mirror_num;
77 unsigned long bio_flags;
78 /*
79 * bio_offset is optional, can be used if the pages in the bio
80 * can't tell us where in the file the bio should go
81 */
82 u64 bio_offset;
83 struct btrfs_work work;
84 };
85
86 /* These are used to set the lockdep class on the extent buffer locks.
87 * The class is set by the readpage_end_io_hook after the buffer has
88 * passed csum validation but before the pages are unlocked.
89 *
90 * The lockdep class is also set by btrfs_init_new_buffer on freshly
91 * allocated blocks.
92 *
93 * The class is based on the level in the tree block, which allows lockdep
94 * to know that lower nodes nest inside the locks of higher nodes.
95 *
96 * We also add a check to make sure the highest level of the tree is
97 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
98 * code needs update as well.
99 */
100 #ifdef CONFIG_DEBUG_LOCK_ALLOC
101 # if BTRFS_MAX_LEVEL != 8
102 # error
103 # endif
104 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
105 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
106 /* leaf */
107 "btrfs-extent-00",
108 "btrfs-extent-01",
109 "btrfs-extent-02",
110 "btrfs-extent-03",
111 "btrfs-extent-04",
112 "btrfs-extent-05",
113 "btrfs-extent-06",
114 "btrfs-extent-07",
115 /* highest possible level */
116 "btrfs-extent-08",
117 };
118 #endif
119
120 /*
121 * extents on the btree inode are pretty simple, there's one extent
122 * that covers the entire device
123 */
124 static struct extent_map *btree_get_extent(struct inode *inode,
125 struct page *page, size_t page_offset, u64 start, u64 len,
126 int create)
127 {
128 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
129 struct extent_map *em;
130 int ret;
131
132 read_lock(&em_tree->lock);
133 em = lookup_extent_mapping(em_tree, start, len);
134 if (em) {
135 em->bdev =
136 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
137 read_unlock(&em_tree->lock);
138 goto out;
139 }
140 read_unlock(&em_tree->lock);
141
142 em = alloc_extent_map(GFP_NOFS);
143 if (!em) {
144 em = ERR_PTR(-ENOMEM);
145 goto out;
146 }
147 em->start = 0;
148 em->len = (u64)-1;
149 em->block_len = (u64)-1;
150 em->block_start = 0;
151 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
152
153 write_lock(&em_tree->lock);
154 ret = add_extent_mapping(em_tree, em);
155 if (ret == -EEXIST) {
156 u64 failed_start = em->start;
157 u64 failed_len = em->len;
158
159 free_extent_map(em);
160 em = lookup_extent_mapping(em_tree, start, len);
161 if (em) {
162 ret = 0;
163 } else {
164 em = lookup_extent_mapping(em_tree, failed_start,
165 failed_len);
166 ret = -EIO;
167 }
168 } else if (ret) {
169 free_extent_map(em);
170 em = NULL;
171 }
172 write_unlock(&em_tree->lock);
173
174 if (ret)
175 em = ERR_PTR(ret);
176 out:
177 return em;
178 }
179
180 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
181 {
182 return crc32c(seed, data, len);
183 }
184
185 void btrfs_csum_final(u32 crc, char *result)
186 {
187 *(__le32 *)result = ~cpu_to_le32(crc);
188 }
189
190 /*
191 * compute the csum for a btree block, and either verify it or write it
192 * into the csum field of the block.
193 */
194 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
195 int verify)
196 {
197 u16 csum_size =
198 btrfs_super_csum_size(&root->fs_info->super_copy);
199 char *result = NULL;
200 unsigned long len;
201 unsigned long cur_len;
202 unsigned long offset = BTRFS_CSUM_SIZE;
203 char *map_token = NULL;
204 char *kaddr;
205 unsigned long map_start;
206 unsigned long map_len;
207 int err;
208 u32 crc = ~(u32)0;
209 unsigned long inline_result;
210
211 len = buf->len - offset;
212 while (len > 0) {
213 err = map_private_extent_buffer(buf, offset, 32,
214 &map_token, &kaddr,
215 &map_start, &map_len, KM_USER0);
216 if (err)
217 return 1;
218 cur_len = min(len, map_len - (offset - map_start));
219 crc = btrfs_csum_data(root, kaddr + offset - map_start,
220 crc, cur_len);
221 len -= cur_len;
222 offset += cur_len;
223 unmap_extent_buffer(buf, map_token, KM_USER0);
224 }
225 if (csum_size > sizeof(inline_result)) {
226 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
227 if (!result)
228 return 1;
229 } else {
230 result = (char *)&inline_result;
231 }
232
233 btrfs_csum_final(crc, result);
234
235 if (verify) {
236 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
237 u32 val;
238 u32 found = 0;
239 memcpy(&found, result, csum_size);
240
241 read_extent_buffer(buf, &val, 0, csum_size);
242 if (printk_ratelimit()) {
243 printk(KERN_INFO "btrfs: %s checksum verify "
244 "failed on %llu wanted %X found %X "
245 "level %d\n",
246 root->fs_info->sb->s_id,
247 (unsigned long long)buf->start, val, found,
248 btrfs_header_level(buf));
249 }
250 if (result != (char *)&inline_result)
251 kfree(result);
252 return 1;
253 }
254 } else {
255 write_extent_buffer(buf, result, 0, csum_size);
256 }
257 if (result != (char *)&inline_result)
258 kfree(result);
259 return 0;
260 }
261
262 /*
263 * we can't consider a given block up to date unless the transid of the
264 * block matches the transid in the parent node's pointer. This is how we
265 * detect blocks that either didn't get written at all or got written
266 * in the wrong place.
267 */
268 static int verify_parent_transid(struct extent_io_tree *io_tree,
269 struct extent_buffer *eb, u64 parent_transid)
270 {
271 struct extent_state *cached_state = NULL;
272 int ret;
273
274 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
275 return 0;
276
277 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
278 0, &cached_state, GFP_NOFS);
279 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
280 btrfs_header_generation(eb) == parent_transid) {
281 ret = 0;
282 goto out;
283 }
284 if (printk_ratelimit()) {
285 printk("parent transid verify failed on %llu wanted %llu "
286 "found %llu\n",
287 (unsigned long long)eb->start,
288 (unsigned long long)parent_transid,
289 (unsigned long long)btrfs_header_generation(eb));
290 }
291 ret = 1;
292 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
293 out:
294 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
295 &cached_state, GFP_NOFS);
296 return ret;
297 }
298
299 /*
300 * helper to read a given tree block, doing retries as required when
301 * the checksums don't match and we have alternate mirrors to try.
302 */
303 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
304 struct extent_buffer *eb,
305 u64 start, u64 parent_transid)
306 {
307 struct extent_io_tree *io_tree;
308 int ret;
309 int num_copies = 0;
310 int mirror_num = 0;
311
312 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
313 while (1) {
314 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
315 btree_get_extent, mirror_num);
316 if (!ret &&
317 !verify_parent_transid(io_tree, eb, parent_transid))
318 return ret;
319
320 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
321 eb->start, eb->len);
322 if (num_copies == 1)
323 return ret;
324
325 mirror_num++;
326 if (mirror_num > num_copies)
327 return ret;
328 }
329 return -EIO;
330 }
331
332 /*
333 * checksum a dirty tree block before IO. This has extra checks to make sure
334 * we only fill in the checksum field in the first page of a multi-page block
335 */
336
337 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
338 {
339 struct extent_io_tree *tree;
340 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
341 u64 found_start;
342 unsigned long len;
343 struct extent_buffer *eb;
344 int ret;
345
346 tree = &BTRFS_I(page->mapping->host)->io_tree;
347
348 if (page->private == EXTENT_PAGE_PRIVATE)
349 goto out;
350 if (!page->private)
351 goto out;
352 len = page->private >> 2;
353 WARN_ON(len == 0);
354
355 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
356 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
357 btrfs_header_generation(eb));
358 BUG_ON(ret);
359 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
360
361 found_start = btrfs_header_bytenr(eb);
362 if (found_start != start) {
363 WARN_ON(1);
364 goto err;
365 }
366 if (eb->first_page != page) {
367 WARN_ON(1);
368 goto err;
369 }
370 if (!PageUptodate(page)) {
371 WARN_ON(1);
372 goto err;
373 }
374 csum_tree_block(root, eb, 0);
375 err:
376 free_extent_buffer(eb);
377 out:
378 return 0;
379 }
380
381 static int check_tree_block_fsid(struct btrfs_root *root,
382 struct extent_buffer *eb)
383 {
384 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
385 u8 fsid[BTRFS_UUID_SIZE];
386 int ret = 1;
387
388 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
389 BTRFS_FSID_SIZE);
390 while (fs_devices) {
391 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
392 ret = 0;
393 break;
394 }
395 fs_devices = fs_devices->seed;
396 }
397 return ret;
398 }
399
400 #ifdef CONFIG_DEBUG_LOCK_ALLOC
401 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
402 {
403 lockdep_set_class_and_name(&eb->lock,
404 &btrfs_eb_class[level],
405 btrfs_eb_name[level]);
406 }
407 #endif
408
409 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
410 struct extent_state *state)
411 {
412 struct extent_io_tree *tree;
413 u64 found_start;
414 int found_level;
415 unsigned long len;
416 struct extent_buffer *eb;
417 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
418 int ret = 0;
419
420 tree = &BTRFS_I(page->mapping->host)->io_tree;
421 if (page->private == EXTENT_PAGE_PRIVATE)
422 goto out;
423 if (!page->private)
424 goto out;
425
426 len = page->private >> 2;
427 WARN_ON(len == 0);
428
429 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
430
431 found_start = btrfs_header_bytenr(eb);
432 if (found_start != start) {
433 if (printk_ratelimit()) {
434 printk(KERN_INFO "btrfs bad tree block start "
435 "%llu %llu\n",
436 (unsigned long long)found_start,
437 (unsigned long long)eb->start);
438 }
439 ret = -EIO;
440 goto err;
441 }
442 if (eb->first_page != page) {
443 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
444 eb->first_page->index, page->index);
445 WARN_ON(1);
446 ret = -EIO;
447 goto err;
448 }
449 if (check_tree_block_fsid(root, eb)) {
450 if (printk_ratelimit()) {
451 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
452 (unsigned long long)eb->start);
453 }
454 ret = -EIO;
455 goto err;
456 }
457 found_level = btrfs_header_level(eb);
458
459 btrfs_set_buffer_lockdep_class(eb, found_level);
460
461 ret = csum_tree_block(root, eb, 1);
462 if (ret)
463 ret = -EIO;
464
465 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
466 end = eb->start + end - 1;
467 err:
468 free_extent_buffer(eb);
469 out:
470 return ret;
471 }
472
473 static void end_workqueue_bio(struct bio *bio, int err)
474 {
475 struct end_io_wq *end_io_wq = bio->bi_private;
476 struct btrfs_fs_info *fs_info;
477
478 fs_info = end_io_wq->info;
479 end_io_wq->error = err;
480 end_io_wq->work.func = end_workqueue_fn;
481 end_io_wq->work.flags = 0;
482
483 if (bio->bi_rw & REQ_WRITE) {
484 if (end_io_wq->metadata == 1)
485 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
486 &end_io_wq->work);
487 else if (end_io_wq->metadata == 2)
488 btrfs_queue_worker(&fs_info->endio_freespace_worker,
489 &end_io_wq->work);
490 else
491 btrfs_queue_worker(&fs_info->endio_write_workers,
492 &end_io_wq->work);
493 } else {
494 if (end_io_wq->metadata)
495 btrfs_queue_worker(&fs_info->endio_meta_workers,
496 &end_io_wq->work);
497 else
498 btrfs_queue_worker(&fs_info->endio_workers,
499 &end_io_wq->work);
500 }
501 }
502
503 /*
504 * For the metadata arg you want
505 *
506 * 0 - if data
507 * 1 - if normal metadta
508 * 2 - if writing to the free space cache area
509 */
510 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
511 int metadata)
512 {
513 struct end_io_wq *end_io_wq;
514 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
515 if (!end_io_wq)
516 return -ENOMEM;
517
518 end_io_wq->private = bio->bi_private;
519 end_io_wq->end_io = bio->bi_end_io;
520 end_io_wq->info = info;
521 end_io_wq->error = 0;
522 end_io_wq->bio = bio;
523 end_io_wq->metadata = metadata;
524
525 bio->bi_private = end_io_wq;
526 bio->bi_end_io = end_workqueue_bio;
527 return 0;
528 }
529
530 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
531 {
532 unsigned long limit = min_t(unsigned long,
533 info->workers.max_workers,
534 info->fs_devices->open_devices);
535 return 256 * limit;
536 }
537
538 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
539 {
540 return atomic_read(&info->nr_async_bios) >
541 btrfs_async_submit_limit(info);
542 }
543
544 static void run_one_async_start(struct btrfs_work *work)
545 {
546 struct async_submit_bio *async;
547
548 async = container_of(work, struct async_submit_bio, work);
549 async->submit_bio_start(async->inode, async->rw, async->bio,
550 async->mirror_num, async->bio_flags,
551 async->bio_offset);
552 }
553
554 static void run_one_async_done(struct btrfs_work *work)
555 {
556 struct btrfs_fs_info *fs_info;
557 struct async_submit_bio *async;
558 int limit;
559
560 async = container_of(work, struct async_submit_bio, work);
561 fs_info = BTRFS_I(async->inode)->root->fs_info;
562
563 limit = btrfs_async_submit_limit(fs_info);
564 limit = limit * 2 / 3;
565
566 atomic_dec(&fs_info->nr_async_submits);
567
568 if (atomic_read(&fs_info->nr_async_submits) < limit &&
569 waitqueue_active(&fs_info->async_submit_wait))
570 wake_up(&fs_info->async_submit_wait);
571
572 async->submit_bio_done(async->inode, async->rw, async->bio,
573 async->mirror_num, async->bio_flags,
574 async->bio_offset);
575 }
576
577 static void run_one_async_free(struct btrfs_work *work)
578 {
579 struct async_submit_bio *async;
580
581 async = container_of(work, struct async_submit_bio, work);
582 kfree(async);
583 }
584
585 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
586 int rw, struct bio *bio, int mirror_num,
587 unsigned long bio_flags,
588 u64 bio_offset,
589 extent_submit_bio_hook_t *submit_bio_start,
590 extent_submit_bio_hook_t *submit_bio_done)
591 {
592 struct async_submit_bio *async;
593
594 async = kmalloc(sizeof(*async), GFP_NOFS);
595 if (!async)
596 return -ENOMEM;
597
598 async->inode = inode;
599 async->rw = rw;
600 async->bio = bio;
601 async->mirror_num = mirror_num;
602 async->submit_bio_start = submit_bio_start;
603 async->submit_bio_done = submit_bio_done;
604
605 async->work.func = run_one_async_start;
606 async->work.ordered_func = run_one_async_done;
607 async->work.ordered_free = run_one_async_free;
608
609 async->work.flags = 0;
610 async->bio_flags = bio_flags;
611 async->bio_offset = bio_offset;
612
613 atomic_inc(&fs_info->nr_async_submits);
614
615 if (rw & REQ_SYNC)
616 btrfs_set_work_high_prio(&async->work);
617
618 btrfs_queue_worker(&fs_info->workers, &async->work);
619
620 while (atomic_read(&fs_info->async_submit_draining) &&
621 atomic_read(&fs_info->nr_async_submits)) {
622 wait_event(fs_info->async_submit_wait,
623 (atomic_read(&fs_info->nr_async_submits) == 0));
624 }
625
626 return 0;
627 }
628
629 static int btree_csum_one_bio(struct bio *bio)
630 {
631 struct bio_vec *bvec = bio->bi_io_vec;
632 int bio_index = 0;
633 struct btrfs_root *root;
634
635 WARN_ON(bio->bi_vcnt <= 0);
636 while (bio_index < bio->bi_vcnt) {
637 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
638 csum_dirty_buffer(root, bvec->bv_page);
639 bio_index++;
640 bvec++;
641 }
642 return 0;
643 }
644
645 static int __btree_submit_bio_start(struct inode *inode, int rw,
646 struct bio *bio, int mirror_num,
647 unsigned long bio_flags,
648 u64 bio_offset)
649 {
650 /*
651 * when we're called for a write, we're already in the async
652 * submission context. Just jump into btrfs_map_bio
653 */
654 btree_csum_one_bio(bio);
655 return 0;
656 }
657
658 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
659 int mirror_num, unsigned long bio_flags,
660 u64 bio_offset)
661 {
662 /*
663 * when we're called for a write, we're already in the async
664 * submission context. Just jump into btrfs_map_bio
665 */
666 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
667 }
668
669 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
670 int mirror_num, unsigned long bio_flags,
671 u64 bio_offset)
672 {
673 int ret;
674
675 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
676 bio, 1);
677 BUG_ON(ret);
678
679 if (!(rw & REQ_WRITE)) {
680 /*
681 * called for a read, do the setup so that checksum validation
682 * can happen in the async kernel threads
683 */
684 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
685 mirror_num, 0);
686 }
687
688 /*
689 * kthread helpers are used to submit writes so that checksumming
690 * can happen in parallel across all CPUs
691 */
692 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
693 inode, rw, bio, mirror_num, 0,
694 bio_offset,
695 __btree_submit_bio_start,
696 __btree_submit_bio_done);
697 }
698
699 #ifdef CONFIG_MIGRATION
700 static int btree_migratepage(struct address_space *mapping,
701 struct page *newpage, struct page *page)
702 {
703 /*
704 * we can't safely write a btree page from here,
705 * we haven't done the locking hook
706 */
707 if (PageDirty(page))
708 return -EAGAIN;
709 /*
710 * Buffers may be managed in a filesystem specific way.
711 * We must have no buffers or drop them.
712 */
713 if (page_has_private(page) &&
714 !try_to_release_page(page, GFP_KERNEL))
715 return -EAGAIN;
716 return migrate_page(mapping, newpage, page);
717 }
718 #endif
719
720 static int btree_writepage(struct page *page, struct writeback_control *wbc)
721 {
722 struct extent_io_tree *tree;
723 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
724 struct extent_buffer *eb;
725 int was_dirty;
726
727 tree = &BTRFS_I(page->mapping->host)->io_tree;
728 if (!(current->flags & PF_MEMALLOC)) {
729 return extent_write_full_page(tree, page,
730 btree_get_extent, wbc);
731 }
732
733 redirty_page_for_writepage(wbc, page);
734 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
735 WARN_ON(!eb);
736
737 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
738 if (!was_dirty) {
739 spin_lock(&root->fs_info->delalloc_lock);
740 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
741 spin_unlock(&root->fs_info->delalloc_lock);
742 }
743 free_extent_buffer(eb);
744
745 unlock_page(page);
746 return 0;
747 }
748
749 static int btree_writepages(struct address_space *mapping,
750 struct writeback_control *wbc)
751 {
752 struct extent_io_tree *tree;
753 tree = &BTRFS_I(mapping->host)->io_tree;
754 if (wbc->sync_mode == WB_SYNC_NONE) {
755 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
756 u64 num_dirty;
757 unsigned long thresh = 32 * 1024 * 1024;
758
759 if (wbc->for_kupdate)
760 return 0;
761
762 /* this is a bit racy, but that's ok */
763 num_dirty = root->fs_info->dirty_metadata_bytes;
764 if (num_dirty < thresh)
765 return 0;
766 }
767 return extent_writepages(tree, mapping, btree_get_extent, wbc);
768 }
769
770 static int btree_readpage(struct file *file, struct page *page)
771 {
772 struct extent_io_tree *tree;
773 tree = &BTRFS_I(page->mapping->host)->io_tree;
774 return extent_read_full_page(tree, page, btree_get_extent);
775 }
776
777 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
778 {
779 struct extent_io_tree *tree;
780 struct extent_map_tree *map;
781 int ret;
782
783 if (PageWriteback(page) || PageDirty(page))
784 return 0;
785
786 tree = &BTRFS_I(page->mapping->host)->io_tree;
787 map = &BTRFS_I(page->mapping->host)->extent_tree;
788
789 ret = try_release_extent_state(map, tree, page, gfp_flags);
790 if (!ret)
791 return 0;
792
793 ret = try_release_extent_buffer(tree, page);
794 if (ret == 1) {
795 ClearPagePrivate(page);
796 set_page_private(page, 0);
797 page_cache_release(page);
798 }
799
800 return ret;
801 }
802
803 static void btree_invalidatepage(struct page *page, unsigned long offset)
804 {
805 struct extent_io_tree *tree;
806 tree = &BTRFS_I(page->mapping->host)->io_tree;
807 extent_invalidatepage(tree, page, offset);
808 btree_releasepage(page, GFP_NOFS);
809 if (PagePrivate(page)) {
810 printk(KERN_WARNING "btrfs warning page private not zero "
811 "on page %llu\n", (unsigned long long)page_offset(page));
812 ClearPagePrivate(page);
813 set_page_private(page, 0);
814 page_cache_release(page);
815 }
816 }
817
818 static const struct address_space_operations btree_aops = {
819 .readpage = btree_readpage,
820 .writepage = btree_writepage,
821 .writepages = btree_writepages,
822 .releasepage = btree_releasepage,
823 .invalidatepage = btree_invalidatepage,
824 .sync_page = block_sync_page,
825 #ifdef CONFIG_MIGRATION
826 .migratepage = btree_migratepage,
827 #endif
828 };
829
830 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
831 u64 parent_transid)
832 {
833 struct extent_buffer *buf = NULL;
834 struct inode *btree_inode = root->fs_info->btree_inode;
835 int ret = 0;
836
837 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
838 if (!buf)
839 return 0;
840 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
841 buf, 0, 0, btree_get_extent, 0);
842 free_extent_buffer(buf);
843 return ret;
844 }
845
846 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
847 u64 bytenr, u32 blocksize)
848 {
849 struct inode *btree_inode = root->fs_info->btree_inode;
850 struct extent_buffer *eb;
851 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
852 bytenr, blocksize, GFP_NOFS);
853 return eb;
854 }
855
856 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
857 u64 bytenr, u32 blocksize)
858 {
859 struct inode *btree_inode = root->fs_info->btree_inode;
860 struct extent_buffer *eb;
861
862 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
863 bytenr, blocksize, NULL, GFP_NOFS);
864 return eb;
865 }
866
867
868 int btrfs_write_tree_block(struct extent_buffer *buf)
869 {
870 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
871 buf->start + buf->len - 1);
872 }
873
874 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
875 {
876 return filemap_fdatawait_range(buf->first_page->mapping,
877 buf->start, buf->start + buf->len - 1);
878 }
879
880 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
881 u32 blocksize, u64 parent_transid)
882 {
883 struct extent_buffer *buf = NULL;
884 int ret;
885
886 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
887 if (!buf)
888 return NULL;
889
890 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
891
892 if (ret == 0)
893 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
894 return buf;
895
896 }
897
898 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
899 struct extent_buffer *buf)
900 {
901 struct inode *btree_inode = root->fs_info->btree_inode;
902 if (btrfs_header_generation(buf) ==
903 root->fs_info->running_transaction->transid) {
904 btrfs_assert_tree_locked(buf);
905
906 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
907 spin_lock(&root->fs_info->delalloc_lock);
908 if (root->fs_info->dirty_metadata_bytes >= buf->len)
909 root->fs_info->dirty_metadata_bytes -= buf->len;
910 else
911 WARN_ON(1);
912 spin_unlock(&root->fs_info->delalloc_lock);
913 }
914
915 /* ugh, clear_extent_buffer_dirty needs to lock the page */
916 btrfs_set_lock_blocking(buf);
917 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
918 buf);
919 }
920 return 0;
921 }
922
923 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
924 u32 stripesize, struct btrfs_root *root,
925 struct btrfs_fs_info *fs_info,
926 u64 objectid)
927 {
928 root->node = NULL;
929 root->commit_root = NULL;
930 root->sectorsize = sectorsize;
931 root->nodesize = nodesize;
932 root->leafsize = leafsize;
933 root->stripesize = stripesize;
934 root->ref_cows = 0;
935 root->track_dirty = 0;
936 root->in_radix = 0;
937 root->orphan_item_inserted = 0;
938 root->orphan_cleanup_state = 0;
939
940 root->fs_info = fs_info;
941 root->objectid = objectid;
942 root->last_trans = 0;
943 root->highest_objectid = 0;
944 root->name = NULL;
945 root->in_sysfs = 0;
946 root->inode_tree = RB_ROOT;
947 root->block_rsv = NULL;
948 root->orphan_block_rsv = NULL;
949
950 INIT_LIST_HEAD(&root->dirty_list);
951 INIT_LIST_HEAD(&root->orphan_list);
952 INIT_LIST_HEAD(&root->root_list);
953 spin_lock_init(&root->node_lock);
954 spin_lock_init(&root->orphan_lock);
955 spin_lock_init(&root->inode_lock);
956 spin_lock_init(&root->accounting_lock);
957 mutex_init(&root->objectid_mutex);
958 mutex_init(&root->log_mutex);
959 init_waitqueue_head(&root->log_writer_wait);
960 init_waitqueue_head(&root->log_commit_wait[0]);
961 init_waitqueue_head(&root->log_commit_wait[1]);
962 atomic_set(&root->log_commit[0], 0);
963 atomic_set(&root->log_commit[1], 0);
964 atomic_set(&root->log_writers, 0);
965 root->log_batch = 0;
966 root->log_transid = 0;
967 root->last_log_commit = 0;
968 extent_io_tree_init(&root->dirty_log_pages,
969 fs_info->btree_inode->i_mapping, GFP_NOFS);
970
971 memset(&root->root_key, 0, sizeof(root->root_key));
972 memset(&root->root_item, 0, sizeof(root->root_item));
973 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
974 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
975 root->defrag_trans_start = fs_info->generation;
976 init_completion(&root->kobj_unregister);
977 root->defrag_running = 0;
978 root->root_key.objectid = objectid;
979 root->anon_super.s_root = NULL;
980 root->anon_super.s_dev = 0;
981 INIT_LIST_HEAD(&root->anon_super.s_list);
982 INIT_LIST_HEAD(&root->anon_super.s_instances);
983 init_rwsem(&root->anon_super.s_umount);
984
985 return 0;
986 }
987
988 static int find_and_setup_root(struct btrfs_root *tree_root,
989 struct btrfs_fs_info *fs_info,
990 u64 objectid,
991 struct btrfs_root *root)
992 {
993 int ret;
994 u32 blocksize;
995 u64 generation;
996
997 __setup_root(tree_root->nodesize, tree_root->leafsize,
998 tree_root->sectorsize, tree_root->stripesize,
999 root, fs_info, objectid);
1000 ret = btrfs_find_last_root(tree_root, objectid,
1001 &root->root_item, &root->root_key);
1002 if (ret > 0)
1003 return -ENOENT;
1004 BUG_ON(ret);
1005
1006 generation = btrfs_root_generation(&root->root_item);
1007 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1008 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1009 blocksize, generation);
1010 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1011 free_extent_buffer(root->node);
1012 return -EIO;
1013 }
1014 root->commit_root = btrfs_root_node(root);
1015 return 0;
1016 }
1017
1018 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1019 struct btrfs_fs_info *fs_info)
1020 {
1021 struct btrfs_root *root;
1022 struct btrfs_root *tree_root = fs_info->tree_root;
1023 struct extent_buffer *leaf;
1024
1025 root = kzalloc(sizeof(*root), GFP_NOFS);
1026 if (!root)
1027 return ERR_PTR(-ENOMEM);
1028
1029 __setup_root(tree_root->nodesize, tree_root->leafsize,
1030 tree_root->sectorsize, tree_root->stripesize,
1031 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1032
1033 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1034 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1035 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1036 /*
1037 * log trees do not get reference counted because they go away
1038 * before a real commit is actually done. They do store pointers
1039 * to file data extents, and those reference counts still get
1040 * updated (along with back refs to the log tree).
1041 */
1042 root->ref_cows = 0;
1043
1044 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1045 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1046 if (IS_ERR(leaf)) {
1047 kfree(root);
1048 return ERR_CAST(leaf);
1049 }
1050
1051 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1052 btrfs_set_header_bytenr(leaf, leaf->start);
1053 btrfs_set_header_generation(leaf, trans->transid);
1054 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1055 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1056 root->node = leaf;
1057
1058 write_extent_buffer(root->node, root->fs_info->fsid,
1059 (unsigned long)btrfs_header_fsid(root->node),
1060 BTRFS_FSID_SIZE);
1061 btrfs_mark_buffer_dirty(root->node);
1062 btrfs_tree_unlock(root->node);
1063 return root;
1064 }
1065
1066 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1067 struct btrfs_fs_info *fs_info)
1068 {
1069 struct btrfs_root *log_root;
1070
1071 log_root = alloc_log_tree(trans, fs_info);
1072 if (IS_ERR(log_root))
1073 return PTR_ERR(log_root);
1074 WARN_ON(fs_info->log_root_tree);
1075 fs_info->log_root_tree = log_root;
1076 return 0;
1077 }
1078
1079 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1080 struct btrfs_root *root)
1081 {
1082 struct btrfs_root *log_root;
1083 struct btrfs_inode_item *inode_item;
1084
1085 log_root = alloc_log_tree(trans, root->fs_info);
1086 if (IS_ERR(log_root))
1087 return PTR_ERR(log_root);
1088
1089 log_root->last_trans = trans->transid;
1090 log_root->root_key.offset = root->root_key.objectid;
1091
1092 inode_item = &log_root->root_item.inode;
1093 inode_item->generation = cpu_to_le64(1);
1094 inode_item->size = cpu_to_le64(3);
1095 inode_item->nlink = cpu_to_le32(1);
1096 inode_item->nbytes = cpu_to_le64(root->leafsize);
1097 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1098
1099 btrfs_set_root_node(&log_root->root_item, log_root->node);
1100
1101 WARN_ON(root->log_root);
1102 root->log_root = log_root;
1103 root->log_transid = 0;
1104 root->last_log_commit = 0;
1105 return 0;
1106 }
1107
1108 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1109 struct btrfs_key *location)
1110 {
1111 struct btrfs_root *root;
1112 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1113 struct btrfs_path *path;
1114 struct extent_buffer *l;
1115 u64 generation;
1116 u32 blocksize;
1117 int ret = 0;
1118
1119 root = kzalloc(sizeof(*root), GFP_NOFS);
1120 if (!root)
1121 return ERR_PTR(-ENOMEM);
1122 if (location->offset == (u64)-1) {
1123 ret = find_and_setup_root(tree_root, fs_info,
1124 location->objectid, root);
1125 if (ret) {
1126 kfree(root);
1127 return ERR_PTR(ret);
1128 }
1129 goto out;
1130 }
1131
1132 __setup_root(tree_root->nodesize, tree_root->leafsize,
1133 tree_root->sectorsize, tree_root->stripesize,
1134 root, fs_info, location->objectid);
1135
1136 path = btrfs_alloc_path();
1137 BUG_ON(!path);
1138 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1139 if (ret == 0) {
1140 l = path->nodes[0];
1141 read_extent_buffer(l, &root->root_item,
1142 btrfs_item_ptr_offset(l, path->slots[0]),
1143 sizeof(root->root_item));
1144 memcpy(&root->root_key, location, sizeof(*location));
1145 }
1146 btrfs_free_path(path);
1147 if (ret) {
1148 if (ret > 0)
1149 ret = -ENOENT;
1150 return ERR_PTR(ret);
1151 }
1152
1153 generation = btrfs_root_generation(&root->root_item);
1154 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1155 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1156 blocksize, generation);
1157 root->commit_root = btrfs_root_node(root);
1158 BUG_ON(!root->node);
1159 out:
1160 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1161 root->ref_cows = 1;
1162
1163 return root;
1164 }
1165
1166 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1167 u64 root_objectid)
1168 {
1169 struct btrfs_root *root;
1170
1171 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1172 return fs_info->tree_root;
1173 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1174 return fs_info->extent_root;
1175
1176 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1177 (unsigned long)root_objectid);
1178 return root;
1179 }
1180
1181 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1182 struct btrfs_key *location)
1183 {
1184 struct btrfs_root *root;
1185 int ret;
1186
1187 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1188 return fs_info->tree_root;
1189 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1190 return fs_info->extent_root;
1191 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1192 return fs_info->chunk_root;
1193 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1194 return fs_info->dev_root;
1195 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1196 return fs_info->csum_root;
1197 again:
1198 spin_lock(&fs_info->fs_roots_radix_lock);
1199 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1200 (unsigned long)location->objectid);
1201 spin_unlock(&fs_info->fs_roots_radix_lock);
1202 if (root)
1203 return root;
1204
1205 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1206 if (IS_ERR(root))
1207 return root;
1208
1209 set_anon_super(&root->anon_super, NULL);
1210
1211 if (btrfs_root_refs(&root->root_item) == 0) {
1212 ret = -ENOENT;
1213 goto fail;
1214 }
1215
1216 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1217 if (ret < 0)
1218 goto fail;
1219 if (ret == 0)
1220 root->orphan_item_inserted = 1;
1221
1222 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1223 if (ret)
1224 goto fail;
1225
1226 spin_lock(&fs_info->fs_roots_radix_lock);
1227 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1228 (unsigned long)root->root_key.objectid,
1229 root);
1230 if (ret == 0)
1231 root->in_radix = 1;
1232
1233 spin_unlock(&fs_info->fs_roots_radix_lock);
1234 radix_tree_preload_end();
1235 if (ret) {
1236 if (ret == -EEXIST) {
1237 free_fs_root(root);
1238 goto again;
1239 }
1240 goto fail;
1241 }
1242
1243 ret = btrfs_find_dead_roots(fs_info->tree_root,
1244 root->root_key.objectid);
1245 WARN_ON(ret);
1246 return root;
1247 fail:
1248 free_fs_root(root);
1249 return ERR_PTR(ret);
1250 }
1251
1252 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1253 struct btrfs_key *location,
1254 const char *name, int namelen)
1255 {
1256 return btrfs_read_fs_root_no_name(fs_info, location);
1257 #if 0
1258 struct btrfs_root *root;
1259 int ret;
1260
1261 root = btrfs_read_fs_root_no_name(fs_info, location);
1262 if (!root)
1263 return NULL;
1264
1265 if (root->in_sysfs)
1266 return root;
1267
1268 ret = btrfs_set_root_name(root, name, namelen);
1269 if (ret) {
1270 free_extent_buffer(root->node);
1271 kfree(root);
1272 return ERR_PTR(ret);
1273 }
1274
1275 ret = btrfs_sysfs_add_root(root);
1276 if (ret) {
1277 free_extent_buffer(root->node);
1278 kfree(root->name);
1279 kfree(root);
1280 return ERR_PTR(ret);
1281 }
1282 root->in_sysfs = 1;
1283 return root;
1284 #endif
1285 }
1286
1287 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1288 {
1289 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1290 int ret = 0;
1291 struct btrfs_device *device;
1292 struct backing_dev_info *bdi;
1293
1294 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1295 if (!device->bdev)
1296 continue;
1297 bdi = blk_get_backing_dev_info(device->bdev);
1298 if (bdi && bdi_congested(bdi, bdi_bits)) {
1299 ret = 1;
1300 break;
1301 }
1302 }
1303 return ret;
1304 }
1305
1306 /*
1307 * this unplugs every device on the box, and it is only used when page
1308 * is null
1309 */
1310 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1311 {
1312 struct btrfs_device *device;
1313 struct btrfs_fs_info *info;
1314
1315 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1316 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1317 if (!device->bdev)
1318 continue;
1319
1320 bdi = blk_get_backing_dev_info(device->bdev);
1321 if (bdi->unplug_io_fn)
1322 bdi->unplug_io_fn(bdi, page);
1323 }
1324 }
1325
1326 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1327 {
1328 struct inode *inode;
1329 struct extent_map_tree *em_tree;
1330 struct extent_map *em;
1331 struct address_space *mapping;
1332 u64 offset;
1333
1334 /* the generic O_DIRECT read code does this */
1335 if (1 || !page) {
1336 __unplug_io_fn(bdi, page);
1337 return;
1338 }
1339
1340 /*
1341 * page->mapping may change at any time. Get a consistent copy
1342 * and use that for everything below
1343 */
1344 smp_mb();
1345 mapping = page->mapping;
1346 if (!mapping)
1347 return;
1348
1349 inode = mapping->host;
1350
1351 /*
1352 * don't do the expensive searching for a small number of
1353 * devices
1354 */
1355 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1356 __unplug_io_fn(bdi, page);
1357 return;
1358 }
1359
1360 offset = page_offset(page);
1361
1362 em_tree = &BTRFS_I(inode)->extent_tree;
1363 read_lock(&em_tree->lock);
1364 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1365 read_unlock(&em_tree->lock);
1366 if (!em) {
1367 __unplug_io_fn(bdi, page);
1368 return;
1369 }
1370
1371 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1372 free_extent_map(em);
1373 __unplug_io_fn(bdi, page);
1374 return;
1375 }
1376 offset = offset - em->start;
1377 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1378 em->block_start + offset, page);
1379 free_extent_map(em);
1380 }
1381
1382 /*
1383 * If this fails, caller must call bdi_destroy() to get rid of the
1384 * bdi again.
1385 */
1386 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1387 {
1388 int err;
1389
1390 bdi->capabilities = BDI_CAP_MAP_COPY;
1391 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1392 if (err)
1393 return err;
1394
1395 bdi->ra_pages = default_backing_dev_info.ra_pages;
1396 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1397 bdi->unplug_io_data = info;
1398 bdi->congested_fn = btrfs_congested_fn;
1399 bdi->congested_data = info;
1400 return 0;
1401 }
1402
1403 static int bio_ready_for_csum(struct bio *bio)
1404 {
1405 u64 length = 0;
1406 u64 buf_len = 0;
1407 u64 start = 0;
1408 struct page *page;
1409 struct extent_io_tree *io_tree = NULL;
1410 struct bio_vec *bvec;
1411 int i;
1412 int ret;
1413
1414 bio_for_each_segment(bvec, bio, i) {
1415 page = bvec->bv_page;
1416 if (page->private == EXTENT_PAGE_PRIVATE) {
1417 length += bvec->bv_len;
1418 continue;
1419 }
1420 if (!page->private) {
1421 length += bvec->bv_len;
1422 continue;
1423 }
1424 length = bvec->bv_len;
1425 buf_len = page->private >> 2;
1426 start = page_offset(page) + bvec->bv_offset;
1427 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1428 }
1429 /* are we fully contained in this bio? */
1430 if (buf_len <= length)
1431 return 1;
1432
1433 ret = extent_range_uptodate(io_tree, start + length,
1434 start + buf_len - 1);
1435 return ret;
1436 }
1437
1438 /*
1439 * called by the kthread helper functions to finally call the bio end_io
1440 * functions. This is where read checksum verification actually happens
1441 */
1442 static void end_workqueue_fn(struct btrfs_work *work)
1443 {
1444 struct bio *bio;
1445 struct end_io_wq *end_io_wq;
1446 struct btrfs_fs_info *fs_info;
1447 int error;
1448
1449 end_io_wq = container_of(work, struct end_io_wq, work);
1450 bio = end_io_wq->bio;
1451 fs_info = end_io_wq->info;
1452
1453 /* metadata bio reads are special because the whole tree block must
1454 * be checksummed at once. This makes sure the entire block is in
1455 * ram and up to date before trying to verify things. For
1456 * blocksize <= pagesize, it is basically a noop
1457 */
1458 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1459 !bio_ready_for_csum(bio)) {
1460 btrfs_queue_worker(&fs_info->endio_meta_workers,
1461 &end_io_wq->work);
1462 return;
1463 }
1464 error = end_io_wq->error;
1465 bio->bi_private = end_io_wq->private;
1466 bio->bi_end_io = end_io_wq->end_io;
1467 kfree(end_io_wq);
1468 bio_endio(bio, error);
1469 }
1470
1471 static int cleaner_kthread(void *arg)
1472 {
1473 struct btrfs_root *root = arg;
1474
1475 do {
1476 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1477
1478 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1479 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1480 btrfs_run_delayed_iputs(root);
1481 btrfs_clean_old_snapshots(root);
1482 mutex_unlock(&root->fs_info->cleaner_mutex);
1483 }
1484
1485 if (freezing(current)) {
1486 refrigerator();
1487 } else {
1488 set_current_state(TASK_INTERRUPTIBLE);
1489 if (!kthread_should_stop())
1490 schedule();
1491 __set_current_state(TASK_RUNNING);
1492 }
1493 } while (!kthread_should_stop());
1494 return 0;
1495 }
1496
1497 static int transaction_kthread(void *arg)
1498 {
1499 struct btrfs_root *root = arg;
1500 struct btrfs_trans_handle *trans;
1501 struct btrfs_transaction *cur;
1502 u64 transid;
1503 unsigned long now;
1504 unsigned long delay;
1505 int ret;
1506
1507 do {
1508 delay = HZ * 30;
1509 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1510 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1511
1512 spin_lock(&root->fs_info->new_trans_lock);
1513 cur = root->fs_info->running_transaction;
1514 if (!cur) {
1515 spin_unlock(&root->fs_info->new_trans_lock);
1516 goto sleep;
1517 }
1518
1519 now = get_seconds();
1520 if (!cur->blocked &&
1521 (now < cur->start_time || now - cur->start_time < 30)) {
1522 spin_unlock(&root->fs_info->new_trans_lock);
1523 delay = HZ * 5;
1524 goto sleep;
1525 }
1526 transid = cur->transid;
1527 spin_unlock(&root->fs_info->new_trans_lock);
1528
1529 trans = btrfs_join_transaction(root, 1);
1530 if (transid == trans->transid) {
1531 ret = btrfs_commit_transaction(trans, root);
1532 BUG_ON(ret);
1533 } else {
1534 btrfs_end_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 set_current_state(TASK_INTERRUPTIBLE);
1544 if (!kthread_should_stop() &&
1545 !btrfs_transaction_blocked(root->fs_info))
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 = btrfs_sb(sb);
1571 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1572 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1573 GFP_NOFS);
1574 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1575 GFP_NOFS);
1576 struct btrfs_root *log_tree_root;
1577
1578 int ret;
1579 int err = -EINVAL;
1580
1581 struct btrfs_super_block *disk_super;
1582
1583 if (!extent_root || !tree_root || !fs_info ||
1584 !chunk_root || !dev_root || !csum_root) {
1585 err = -ENOMEM;
1586 goto fail;
1587 }
1588
1589 ret = init_srcu_struct(&fs_info->subvol_srcu);
1590 if (ret) {
1591 err = ret;
1592 goto fail;
1593 }
1594
1595 ret = setup_bdi(fs_info, &fs_info->bdi);
1596 if (ret) {
1597 err = ret;
1598 goto fail_srcu;
1599 }
1600
1601 fs_info->btree_inode = new_inode(sb);
1602 if (!fs_info->btree_inode) {
1603 err = -ENOMEM;
1604 goto fail_bdi;
1605 }
1606
1607 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1608 INIT_LIST_HEAD(&fs_info->trans_list);
1609 INIT_LIST_HEAD(&fs_info->dead_roots);
1610 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1611 INIT_LIST_HEAD(&fs_info->hashers);
1612 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1613 INIT_LIST_HEAD(&fs_info->ordered_operations);
1614 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1615 spin_lock_init(&fs_info->delalloc_lock);
1616 spin_lock_init(&fs_info->new_trans_lock);
1617 spin_lock_init(&fs_info->ref_cache_lock);
1618 spin_lock_init(&fs_info->fs_roots_radix_lock);
1619 spin_lock_init(&fs_info->delayed_iput_lock);
1620
1621 init_completion(&fs_info->kobj_unregister);
1622 fs_info->tree_root = tree_root;
1623 fs_info->extent_root = extent_root;
1624 fs_info->csum_root = csum_root;
1625 fs_info->chunk_root = chunk_root;
1626 fs_info->dev_root = dev_root;
1627 fs_info->fs_devices = fs_devices;
1628 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1629 INIT_LIST_HEAD(&fs_info->space_info);
1630 btrfs_mapping_init(&fs_info->mapping_tree);
1631 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1632 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1633 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1634 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1635 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1636 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1637 mutex_init(&fs_info->durable_block_rsv_mutex);
1638 atomic_set(&fs_info->nr_async_submits, 0);
1639 atomic_set(&fs_info->async_delalloc_pages, 0);
1640 atomic_set(&fs_info->async_submit_draining, 0);
1641 atomic_set(&fs_info->nr_async_bios, 0);
1642 fs_info->sb = sb;
1643 fs_info->max_inline = 8192 * 1024;
1644 fs_info->metadata_ratio = 0;
1645
1646 fs_info->thread_pool_size = min_t(unsigned long,
1647 num_online_cpus() + 2, 8);
1648
1649 INIT_LIST_HEAD(&fs_info->ordered_extents);
1650 spin_lock_init(&fs_info->ordered_extent_lock);
1651
1652 sb->s_blocksize = 4096;
1653 sb->s_blocksize_bits = blksize_bits(4096);
1654 sb->s_bdi = &fs_info->bdi;
1655
1656 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1657 fs_info->btree_inode->i_nlink = 1;
1658 /*
1659 * we set the i_size on the btree inode to the max possible int.
1660 * the real end of the address space is determined by all of
1661 * the devices in the system
1662 */
1663 fs_info->btree_inode->i_size = OFFSET_MAX;
1664 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1665 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1666
1667 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1668 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1669 fs_info->btree_inode->i_mapping,
1670 GFP_NOFS);
1671 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1672 GFP_NOFS);
1673
1674 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1675
1676 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1677 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1678 sizeof(struct btrfs_key));
1679 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1680 insert_inode_hash(fs_info->btree_inode);
1681
1682 spin_lock_init(&fs_info->block_group_cache_lock);
1683 fs_info->block_group_cache_tree = RB_ROOT;
1684
1685 extent_io_tree_init(&fs_info->freed_extents[0],
1686 fs_info->btree_inode->i_mapping, GFP_NOFS);
1687 extent_io_tree_init(&fs_info->freed_extents[1],
1688 fs_info->btree_inode->i_mapping, GFP_NOFS);
1689 fs_info->pinned_extents = &fs_info->freed_extents[0];
1690 fs_info->do_barriers = 1;
1691
1692
1693 mutex_init(&fs_info->trans_mutex);
1694 mutex_init(&fs_info->ordered_operations_mutex);
1695 mutex_init(&fs_info->tree_log_mutex);
1696 mutex_init(&fs_info->chunk_mutex);
1697 mutex_init(&fs_info->transaction_kthread_mutex);
1698 mutex_init(&fs_info->cleaner_mutex);
1699 mutex_init(&fs_info->volume_mutex);
1700 init_rwsem(&fs_info->extent_commit_sem);
1701 init_rwsem(&fs_info->cleanup_work_sem);
1702 init_rwsem(&fs_info->subvol_sem);
1703
1704 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1705 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1706
1707 init_waitqueue_head(&fs_info->transaction_throttle);
1708 init_waitqueue_head(&fs_info->transaction_wait);
1709 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1710 init_waitqueue_head(&fs_info->async_submit_wait);
1711
1712 __setup_root(4096, 4096, 4096, 4096, tree_root,
1713 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1714
1715 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1716 if (!bh)
1717 goto fail_iput;
1718
1719 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1720 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1721 sizeof(fs_info->super_for_commit));
1722 brelse(bh);
1723
1724 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1725
1726 disk_super = &fs_info->super_copy;
1727 if (!btrfs_super_root(disk_super))
1728 goto fail_iput;
1729
1730 ret = btrfs_parse_options(tree_root, options);
1731 if (ret) {
1732 err = ret;
1733 goto fail_iput;
1734 }
1735
1736 features = btrfs_super_incompat_flags(disk_super) &
1737 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1738 if (features) {
1739 printk(KERN_ERR "BTRFS: couldn't mount because of "
1740 "unsupported optional features (%Lx).\n",
1741 (unsigned long long)features);
1742 err = -EINVAL;
1743 goto fail_iput;
1744 }
1745
1746 features = btrfs_super_incompat_flags(disk_super);
1747 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1748 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1749 btrfs_set_super_incompat_flags(disk_super, features);
1750 }
1751
1752 features = btrfs_super_compat_ro_flags(disk_super) &
1753 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1754 if (!(sb->s_flags & MS_RDONLY) && features) {
1755 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1756 "unsupported option features (%Lx).\n",
1757 (unsigned long long)features);
1758 err = -EINVAL;
1759 goto fail_iput;
1760 }
1761
1762 btrfs_init_workers(&fs_info->generic_worker,
1763 "genwork", 1, NULL);
1764
1765 btrfs_init_workers(&fs_info->workers, "worker",
1766 fs_info->thread_pool_size,
1767 &fs_info->generic_worker);
1768
1769 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1770 fs_info->thread_pool_size,
1771 &fs_info->generic_worker);
1772
1773 btrfs_init_workers(&fs_info->submit_workers, "submit",
1774 min_t(u64, fs_devices->num_devices,
1775 fs_info->thread_pool_size),
1776 &fs_info->generic_worker);
1777
1778 /* a higher idle thresh on the submit workers makes it much more
1779 * likely that bios will be send down in a sane order to the
1780 * devices
1781 */
1782 fs_info->submit_workers.idle_thresh = 64;
1783
1784 fs_info->workers.idle_thresh = 16;
1785 fs_info->workers.ordered = 1;
1786
1787 fs_info->delalloc_workers.idle_thresh = 2;
1788 fs_info->delalloc_workers.ordered = 1;
1789
1790 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1791 &fs_info->generic_worker);
1792 btrfs_init_workers(&fs_info->endio_workers, "endio",
1793 fs_info->thread_pool_size,
1794 &fs_info->generic_worker);
1795 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1796 fs_info->thread_pool_size,
1797 &fs_info->generic_worker);
1798 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1799 "endio-meta-write", fs_info->thread_pool_size,
1800 &fs_info->generic_worker);
1801 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1802 fs_info->thread_pool_size,
1803 &fs_info->generic_worker);
1804 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1805 1, &fs_info->generic_worker);
1806
1807 /*
1808 * endios are largely parallel and should have a very
1809 * low idle thresh
1810 */
1811 fs_info->endio_workers.idle_thresh = 4;
1812 fs_info->endio_meta_workers.idle_thresh = 4;
1813
1814 fs_info->endio_write_workers.idle_thresh = 2;
1815 fs_info->endio_meta_write_workers.idle_thresh = 2;
1816
1817 btrfs_start_workers(&fs_info->workers, 1);
1818 btrfs_start_workers(&fs_info->generic_worker, 1);
1819 btrfs_start_workers(&fs_info->submit_workers, 1);
1820 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1821 btrfs_start_workers(&fs_info->fixup_workers, 1);
1822 btrfs_start_workers(&fs_info->endio_workers, 1);
1823 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1824 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1825 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1826 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1827
1828 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1829 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1830 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1831
1832 nodesize = btrfs_super_nodesize(disk_super);
1833 leafsize = btrfs_super_leafsize(disk_super);
1834 sectorsize = btrfs_super_sectorsize(disk_super);
1835 stripesize = btrfs_super_stripesize(disk_super);
1836 tree_root->nodesize = nodesize;
1837 tree_root->leafsize = leafsize;
1838 tree_root->sectorsize = sectorsize;
1839 tree_root->stripesize = stripesize;
1840
1841 sb->s_blocksize = sectorsize;
1842 sb->s_blocksize_bits = blksize_bits(sectorsize);
1843
1844 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1845 sizeof(disk_super->magic))) {
1846 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1847 goto fail_sb_buffer;
1848 }
1849
1850 mutex_lock(&fs_info->chunk_mutex);
1851 ret = btrfs_read_sys_array(tree_root);
1852 mutex_unlock(&fs_info->chunk_mutex);
1853 if (ret) {
1854 printk(KERN_WARNING "btrfs: failed to read the system "
1855 "array on %s\n", sb->s_id);
1856 goto fail_sb_buffer;
1857 }
1858
1859 blocksize = btrfs_level_size(tree_root,
1860 btrfs_super_chunk_root_level(disk_super));
1861 generation = btrfs_super_chunk_root_generation(disk_super);
1862
1863 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1864 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1865
1866 chunk_root->node = read_tree_block(chunk_root,
1867 btrfs_super_chunk_root(disk_super),
1868 blocksize, generation);
1869 BUG_ON(!chunk_root->node);
1870 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1871 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1872 sb->s_id);
1873 goto fail_chunk_root;
1874 }
1875 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1876 chunk_root->commit_root = btrfs_root_node(chunk_root);
1877
1878 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1879 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1880 BTRFS_UUID_SIZE);
1881
1882 mutex_lock(&fs_info->chunk_mutex);
1883 ret = btrfs_read_chunk_tree(chunk_root);
1884 mutex_unlock(&fs_info->chunk_mutex);
1885 if (ret) {
1886 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1887 sb->s_id);
1888 goto fail_chunk_root;
1889 }
1890
1891 btrfs_close_extra_devices(fs_devices);
1892
1893 blocksize = btrfs_level_size(tree_root,
1894 btrfs_super_root_level(disk_super));
1895 generation = btrfs_super_generation(disk_super);
1896
1897 tree_root->node = read_tree_block(tree_root,
1898 btrfs_super_root(disk_super),
1899 blocksize, generation);
1900 if (!tree_root->node)
1901 goto fail_chunk_root;
1902 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1903 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1904 sb->s_id);
1905 goto fail_tree_root;
1906 }
1907 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1908 tree_root->commit_root = btrfs_root_node(tree_root);
1909
1910 ret = find_and_setup_root(tree_root, fs_info,
1911 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1912 if (ret)
1913 goto fail_tree_root;
1914 extent_root->track_dirty = 1;
1915
1916 ret = find_and_setup_root(tree_root, fs_info,
1917 BTRFS_DEV_TREE_OBJECTID, dev_root);
1918 if (ret)
1919 goto fail_extent_root;
1920 dev_root->track_dirty = 1;
1921
1922 ret = find_and_setup_root(tree_root, fs_info,
1923 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1924 if (ret)
1925 goto fail_dev_root;
1926
1927 csum_root->track_dirty = 1;
1928
1929 fs_info->generation = generation;
1930 fs_info->last_trans_committed = generation;
1931 fs_info->data_alloc_profile = (u64)-1;
1932 fs_info->metadata_alloc_profile = (u64)-1;
1933 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1934
1935 ret = btrfs_read_block_groups(extent_root);
1936 if (ret) {
1937 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1938 goto fail_block_groups;
1939 }
1940
1941 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1942 "btrfs-cleaner");
1943 if (IS_ERR(fs_info->cleaner_kthread))
1944 goto fail_block_groups;
1945
1946 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1947 tree_root,
1948 "btrfs-transaction");
1949 if (IS_ERR(fs_info->transaction_kthread))
1950 goto fail_cleaner;
1951
1952 if (!btrfs_test_opt(tree_root, SSD) &&
1953 !btrfs_test_opt(tree_root, NOSSD) &&
1954 !fs_info->fs_devices->rotating) {
1955 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1956 "mode\n");
1957 btrfs_set_opt(fs_info->mount_opt, SSD);
1958 }
1959
1960 if (btrfs_super_log_root(disk_super) != 0) {
1961 u64 bytenr = btrfs_super_log_root(disk_super);
1962
1963 if (fs_devices->rw_devices == 0) {
1964 printk(KERN_WARNING "Btrfs log replay required "
1965 "on RO media\n");
1966 err = -EIO;
1967 goto fail_trans_kthread;
1968 }
1969 blocksize =
1970 btrfs_level_size(tree_root,
1971 btrfs_super_log_root_level(disk_super));
1972
1973 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1974 if (!log_tree_root) {
1975 err = -ENOMEM;
1976 goto fail_trans_kthread;
1977 }
1978
1979 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1980 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1981
1982 log_tree_root->node = read_tree_block(tree_root, bytenr,
1983 blocksize,
1984 generation + 1);
1985 ret = btrfs_recover_log_trees(log_tree_root);
1986 BUG_ON(ret);
1987
1988 if (sb->s_flags & MS_RDONLY) {
1989 ret = btrfs_commit_super(tree_root);
1990 BUG_ON(ret);
1991 }
1992 }
1993
1994 ret = btrfs_find_orphan_roots(tree_root);
1995 BUG_ON(ret);
1996
1997 if (!(sb->s_flags & MS_RDONLY)) {
1998 ret = btrfs_cleanup_fs_roots(fs_info);
1999 BUG_ON(ret);
2000
2001 ret = btrfs_recover_relocation(tree_root);
2002 if (ret < 0) {
2003 printk(KERN_WARNING
2004 "btrfs: failed to recover relocation\n");
2005 err = -EINVAL;
2006 goto fail_trans_kthread;
2007 }
2008 }
2009
2010 location.objectid = BTRFS_FS_TREE_OBJECTID;
2011 location.type = BTRFS_ROOT_ITEM_KEY;
2012 location.offset = (u64)-1;
2013
2014 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2015 if (!fs_info->fs_root)
2016 goto fail_trans_kthread;
2017 if (IS_ERR(fs_info->fs_root)) {
2018 err = PTR_ERR(fs_info->fs_root);
2019 goto fail_trans_kthread;
2020 }
2021
2022 if (!(sb->s_flags & MS_RDONLY)) {
2023 down_read(&fs_info->cleanup_work_sem);
2024 btrfs_orphan_cleanup(fs_info->fs_root);
2025 btrfs_orphan_cleanup(fs_info->tree_root);
2026 up_read(&fs_info->cleanup_work_sem);
2027 }
2028
2029 return tree_root;
2030
2031 fail_trans_kthread:
2032 kthread_stop(fs_info->transaction_kthread);
2033 fail_cleaner:
2034 kthread_stop(fs_info->cleaner_kthread);
2035
2036 /*
2037 * make sure we're done with the btree inode before we stop our
2038 * kthreads
2039 */
2040 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2041 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2042
2043 fail_block_groups:
2044 btrfs_free_block_groups(fs_info);
2045 free_extent_buffer(csum_root->node);
2046 free_extent_buffer(csum_root->commit_root);
2047 fail_dev_root:
2048 free_extent_buffer(dev_root->node);
2049 free_extent_buffer(dev_root->commit_root);
2050 fail_extent_root:
2051 free_extent_buffer(extent_root->node);
2052 free_extent_buffer(extent_root->commit_root);
2053 fail_tree_root:
2054 free_extent_buffer(tree_root->node);
2055 free_extent_buffer(tree_root->commit_root);
2056 fail_chunk_root:
2057 free_extent_buffer(chunk_root->node);
2058 free_extent_buffer(chunk_root->commit_root);
2059 fail_sb_buffer:
2060 btrfs_stop_workers(&fs_info->generic_worker);
2061 btrfs_stop_workers(&fs_info->fixup_workers);
2062 btrfs_stop_workers(&fs_info->delalloc_workers);
2063 btrfs_stop_workers(&fs_info->workers);
2064 btrfs_stop_workers(&fs_info->endio_workers);
2065 btrfs_stop_workers(&fs_info->endio_meta_workers);
2066 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2067 btrfs_stop_workers(&fs_info->endio_write_workers);
2068 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2069 btrfs_stop_workers(&fs_info->submit_workers);
2070 fail_iput:
2071 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2072 iput(fs_info->btree_inode);
2073
2074 btrfs_close_devices(fs_info->fs_devices);
2075 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2076 fail_bdi:
2077 bdi_destroy(&fs_info->bdi);
2078 fail_srcu:
2079 cleanup_srcu_struct(&fs_info->subvol_srcu);
2080 fail:
2081 kfree(extent_root);
2082 kfree(tree_root);
2083 kfree(fs_info);
2084 kfree(chunk_root);
2085 kfree(dev_root);
2086 kfree(csum_root);
2087 return ERR_PTR(err);
2088 }
2089
2090 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2091 {
2092 char b[BDEVNAME_SIZE];
2093
2094 if (uptodate) {
2095 set_buffer_uptodate(bh);
2096 } else {
2097 if (printk_ratelimit()) {
2098 printk(KERN_WARNING "lost page write due to "
2099 "I/O error on %s\n",
2100 bdevname(bh->b_bdev, b));
2101 }
2102 /* note, we dont' set_buffer_write_io_error because we have
2103 * our own ways of dealing with the IO errors
2104 */
2105 clear_buffer_uptodate(bh);
2106 }
2107 unlock_buffer(bh);
2108 put_bh(bh);
2109 }
2110
2111 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2112 {
2113 struct buffer_head *bh;
2114 struct buffer_head *latest = NULL;
2115 struct btrfs_super_block *super;
2116 int i;
2117 u64 transid = 0;
2118 u64 bytenr;
2119
2120 /* we would like to check all the supers, but that would make
2121 * a btrfs mount succeed after a mkfs from a different FS.
2122 * So, we need to add a special mount option to scan for
2123 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2124 */
2125 for (i = 0; i < 1; i++) {
2126 bytenr = btrfs_sb_offset(i);
2127 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2128 break;
2129 bh = __bread(bdev, bytenr / 4096, 4096);
2130 if (!bh)
2131 continue;
2132
2133 super = (struct btrfs_super_block *)bh->b_data;
2134 if (btrfs_super_bytenr(super) != bytenr ||
2135 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2136 sizeof(super->magic))) {
2137 brelse(bh);
2138 continue;
2139 }
2140
2141 if (!latest || btrfs_super_generation(super) > transid) {
2142 brelse(latest);
2143 latest = bh;
2144 transid = btrfs_super_generation(super);
2145 } else {
2146 brelse(bh);
2147 }
2148 }
2149 return latest;
2150 }
2151
2152 /*
2153 * this should be called twice, once with wait == 0 and
2154 * once with wait == 1. When wait == 0 is done, all the buffer heads
2155 * we write are pinned.
2156 *
2157 * They are released when wait == 1 is done.
2158 * max_mirrors must be the same for both runs, and it indicates how
2159 * many supers on this one device should be written.
2160 *
2161 * max_mirrors == 0 means to write them all.
2162 */
2163 static int write_dev_supers(struct btrfs_device *device,
2164 struct btrfs_super_block *sb,
2165 int do_barriers, int wait, int max_mirrors)
2166 {
2167 struct buffer_head *bh;
2168 int i;
2169 int ret;
2170 int errors = 0;
2171 u32 crc;
2172 u64 bytenr;
2173 int last_barrier = 0;
2174
2175 if (max_mirrors == 0)
2176 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2177
2178 /* make sure only the last submit_bh does a barrier */
2179 if (do_barriers) {
2180 for (i = 0; i < max_mirrors; i++) {
2181 bytenr = btrfs_sb_offset(i);
2182 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2183 device->total_bytes)
2184 break;
2185 last_barrier = i;
2186 }
2187 }
2188
2189 for (i = 0; i < max_mirrors; i++) {
2190 bytenr = btrfs_sb_offset(i);
2191 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2192 break;
2193
2194 if (wait) {
2195 bh = __find_get_block(device->bdev, bytenr / 4096,
2196 BTRFS_SUPER_INFO_SIZE);
2197 BUG_ON(!bh);
2198 wait_on_buffer(bh);
2199 if (!buffer_uptodate(bh))
2200 errors++;
2201
2202 /* drop our reference */
2203 brelse(bh);
2204
2205 /* drop the reference from the wait == 0 run */
2206 brelse(bh);
2207 continue;
2208 } else {
2209 btrfs_set_super_bytenr(sb, bytenr);
2210
2211 crc = ~(u32)0;
2212 crc = btrfs_csum_data(NULL, (char *)sb +
2213 BTRFS_CSUM_SIZE, crc,
2214 BTRFS_SUPER_INFO_SIZE -
2215 BTRFS_CSUM_SIZE);
2216 btrfs_csum_final(crc, sb->csum);
2217
2218 /*
2219 * one reference for us, and we leave it for the
2220 * caller
2221 */
2222 bh = __getblk(device->bdev, bytenr / 4096,
2223 BTRFS_SUPER_INFO_SIZE);
2224 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2225
2226 /* one reference for submit_bh */
2227 get_bh(bh);
2228
2229 set_buffer_uptodate(bh);
2230 lock_buffer(bh);
2231 bh->b_end_io = btrfs_end_buffer_write_sync;
2232 }
2233
2234 if (i == last_barrier && do_barriers)
2235 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2236 else
2237 ret = submit_bh(WRITE_SYNC, bh);
2238
2239 if (ret)
2240 errors++;
2241 }
2242 return errors < i ? 0 : -1;
2243 }
2244
2245 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2246 {
2247 struct list_head *head;
2248 struct btrfs_device *dev;
2249 struct btrfs_super_block *sb;
2250 struct btrfs_dev_item *dev_item;
2251 int ret;
2252 int do_barriers;
2253 int max_errors;
2254 int total_errors = 0;
2255 u64 flags;
2256
2257 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2258 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2259
2260 sb = &root->fs_info->super_for_commit;
2261 dev_item = &sb->dev_item;
2262
2263 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2264 head = &root->fs_info->fs_devices->devices;
2265 list_for_each_entry(dev, head, dev_list) {
2266 if (!dev->bdev) {
2267 total_errors++;
2268 continue;
2269 }
2270 if (!dev->in_fs_metadata || !dev->writeable)
2271 continue;
2272
2273 btrfs_set_stack_device_generation(dev_item, 0);
2274 btrfs_set_stack_device_type(dev_item, dev->type);
2275 btrfs_set_stack_device_id(dev_item, dev->devid);
2276 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2277 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2278 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2279 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2280 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2281 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2282 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2283
2284 flags = btrfs_super_flags(sb);
2285 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2286
2287 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2288 if (ret)
2289 total_errors++;
2290 }
2291 if (total_errors > max_errors) {
2292 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2293 total_errors);
2294 BUG();
2295 }
2296
2297 total_errors = 0;
2298 list_for_each_entry(dev, head, dev_list) {
2299 if (!dev->bdev)
2300 continue;
2301 if (!dev->in_fs_metadata || !dev->writeable)
2302 continue;
2303
2304 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2305 if (ret)
2306 total_errors++;
2307 }
2308 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2309 if (total_errors > max_errors) {
2310 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2311 total_errors);
2312 BUG();
2313 }
2314 return 0;
2315 }
2316
2317 int write_ctree_super(struct btrfs_trans_handle *trans,
2318 struct btrfs_root *root, int max_mirrors)
2319 {
2320 int ret;
2321
2322 ret = write_all_supers(root, max_mirrors);
2323 return ret;
2324 }
2325
2326 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2327 {
2328 spin_lock(&fs_info->fs_roots_radix_lock);
2329 radix_tree_delete(&fs_info->fs_roots_radix,
2330 (unsigned long)root->root_key.objectid);
2331 spin_unlock(&fs_info->fs_roots_radix_lock);
2332
2333 if (btrfs_root_refs(&root->root_item) == 0)
2334 synchronize_srcu(&fs_info->subvol_srcu);
2335
2336 free_fs_root(root);
2337 return 0;
2338 }
2339
2340 static void free_fs_root(struct btrfs_root *root)
2341 {
2342 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2343 if (root->anon_super.s_dev) {
2344 down_write(&root->anon_super.s_umount);
2345 kill_anon_super(&root->anon_super);
2346 }
2347 free_extent_buffer(root->node);
2348 free_extent_buffer(root->commit_root);
2349 kfree(root->name);
2350 kfree(root);
2351 }
2352
2353 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2354 {
2355 int ret;
2356 struct btrfs_root *gang[8];
2357 int i;
2358
2359 while (!list_empty(&fs_info->dead_roots)) {
2360 gang[0] = list_entry(fs_info->dead_roots.next,
2361 struct btrfs_root, root_list);
2362 list_del(&gang[0]->root_list);
2363
2364 if (gang[0]->in_radix) {
2365 btrfs_free_fs_root(fs_info, gang[0]);
2366 } else {
2367 free_extent_buffer(gang[0]->node);
2368 free_extent_buffer(gang[0]->commit_root);
2369 kfree(gang[0]);
2370 }
2371 }
2372
2373 while (1) {
2374 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2375 (void **)gang, 0,
2376 ARRAY_SIZE(gang));
2377 if (!ret)
2378 break;
2379 for (i = 0; i < ret; i++)
2380 btrfs_free_fs_root(fs_info, gang[i]);
2381 }
2382 return 0;
2383 }
2384
2385 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2386 {
2387 u64 root_objectid = 0;
2388 struct btrfs_root *gang[8];
2389 int i;
2390 int ret;
2391
2392 while (1) {
2393 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2394 (void **)gang, root_objectid,
2395 ARRAY_SIZE(gang));
2396 if (!ret)
2397 break;
2398
2399 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2400 for (i = 0; i < ret; i++) {
2401 root_objectid = gang[i]->root_key.objectid;
2402 btrfs_orphan_cleanup(gang[i]);
2403 }
2404 root_objectid++;
2405 }
2406 return 0;
2407 }
2408
2409 int btrfs_commit_super(struct btrfs_root *root)
2410 {
2411 struct btrfs_trans_handle *trans;
2412 int ret;
2413
2414 mutex_lock(&root->fs_info->cleaner_mutex);
2415 btrfs_run_delayed_iputs(root);
2416 btrfs_clean_old_snapshots(root);
2417 mutex_unlock(&root->fs_info->cleaner_mutex);
2418
2419 /* wait until ongoing cleanup work done */
2420 down_write(&root->fs_info->cleanup_work_sem);
2421 up_write(&root->fs_info->cleanup_work_sem);
2422
2423 trans = btrfs_join_transaction(root, 1);
2424 ret = btrfs_commit_transaction(trans, root);
2425 BUG_ON(ret);
2426 /* run commit again to drop the original snapshot */
2427 trans = btrfs_join_transaction(root, 1);
2428 btrfs_commit_transaction(trans, root);
2429 ret = btrfs_write_and_wait_transaction(NULL, root);
2430 BUG_ON(ret);
2431
2432 ret = write_ctree_super(NULL, root, 0);
2433 return ret;
2434 }
2435
2436 int close_ctree(struct btrfs_root *root)
2437 {
2438 struct btrfs_fs_info *fs_info = root->fs_info;
2439 int ret;
2440
2441 fs_info->closing = 1;
2442 smp_mb();
2443
2444 btrfs_put_block_group_cache(fs_info);
2445 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2446 ret = btrfs_commit_super(root);
2447 if (ret)
2448 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2449 }
2450
2451 kthread_stop(root->fs_info->transaction_kthread);
2452 kthread_stop(root->fs_info->cleaner_kthread);
2453
2454 fs_info->closing = 2;
2455 smp_mb();
2456
2457 if (fs_info->delalloc_bytes) {
2458 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2459 (unsigned long long)fs_info->delalloc_bytes);
2460 }
2461 if (fs_info->total_ref_cache_size) {
2462 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2463 (unsigned long long)fs_info->total_ref_cache_size);
2464 }
2465
2466 free_extent_buffer(fs_info->extent_root->node);
2467 free_extent_buffer(fs_info->extent_root->commit_root);
2468 free_extent_buffer(fs_info->tree_root->node);
2469 free_extent_buffer(fs_info->tree_root->commit_root);
2470 free_extent_buffer(root->fs_info->chunk_root->node);
2471 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2472 free_extent_buffer(root->fs_info->dev_root->node);
2473 free_extent_buffer(root->fs_info->dev_root->commit_root);
2474 free_extent_buffer(root->fs_info->csum_root->node);
2475 free_extent_buffer(root->fs_info->csum_root->commit_root);
2476
2477 btrfs_free_block_groups(root->fs_info);
2478
2479 del_fs_roots(fs_info);
2480
2481 iput(fs_info->btree_inode);
2482
2483 btrfs_stop_workers(&fs_info->generic_worker);
2484 btrfs_stop_workers(&fs_info->fixup_workers);
2485 btrfs_stop_workers(&fs_info->delalloc_workers);
2486 btrfs_stop_workers(&fs_info->workers);
2487 btrfs_stop_workers(&fs_info->endio_workers);
2488 btrfs_stop_workers(&fs_info->endio_meta_workers);
2489 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2490 btrfs_stop_workers(&fs_info->endio_write_workers);
2491 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2492 btrfs_stop_workers(&fs_info->submit_workers);
2493
2494 btrfs_close_devices(fs_info->fs_devices);
2495 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2496
2497 bdi_destroy(&fs_info->bdi);
2498 cleanup_srcu_struct(&fs_info->subvol_srcu);
2499
2500 kfree(fs_info->extent_root);
2501 kfree(fs_info->tree_root);
2502 kfree(fs_info->chunk_root);
2503 kfree(fs_info->dev_root);
2504 kfree(fs_info->csum_root);
2505 return 0;
2506 }
2507
2508 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2509 {
2510 int ret;
2511 struct inode *btree_inode = buf->first_page->mapping->host;
2512
2513 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2514 NULL);
2515 if (!ret)
2516 return ret;
2517
2518 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2519 parent_transid);
2520 return !ret;
2521 }
2522
2523 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2524 {
2525 struct inode *btree_inode = buf->first_page->mapping->host;
2526 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2527 buf);
2528 }
2529
2530 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2531 {
2532 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2533 u64 transid = btrfs_header_generation(buf);
2534 struct inode *btree_inode = root->fs_info->btree_inode;
2535 int was_dirty;
2536
2537 btrfs_assert_tree_locked(buf);
2538 if (transid != root->fs_info->generation) {
2539 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2540 "found %llu running %llu\n",
2541 (unsigned long long)buf->start,
2542 (unsigned long long)transid,
2543 (unsigned long long)root->fs_info->generation);
2544 WARN_ON(1);
2545 }
2546 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2547 buf);
2548 if (!was_dirty) {
2549 spin_lock(&root->fs_info->delalloc_lock);
2550 root->fs_info->dirty_metadata_bytes += buf->len;
2551 spin_unlock(&root->fs_info->delalloc_lock);
2552 }
2553 }
2554
2555 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2556 {
2557 /*
2558 * looks as though older kernels can get into trouble with
2559 * this code, they end up stuck in balance_dirty_pages forever
2560 */
2561 u64 num_dirty;
2562 unsigned long thresh = 32 * 1024 * 1024;
2563
2564 if (current->flags & PF_MEMALLOC)
2565 return;
2566
2567 num_dirty = root->fs_info->dirty_metadata_bytes;
2568
2569 if (num_dirty > thresh) {
2570 balance_dirty_pages_ratelimited_nr(
2571 root->fs_info->btree_inode->i_mapping, 1);
2572 }
2573 return;
2574 }
2575
2576 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2577 {
2578 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2579 int ret;
2580 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2581 if (ret == 0)
2582 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2583 return ret;
2584 }
2585
2586 int btree_lock_page_hook(struct page *page)
2587 {
2588 struct inode *inode = page->mapping->host;
2589 struct btrfs_root *root = BTRFS_I(inode)->root;
2590 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2591 struct extent_buffer *eb;
2592 unsigned long len;
2593 u64 bytenr = page_offset(page);
2594
2595 if (page->private == EXTENT_PAGE_PRIVATE)
2596 goto out;
2597
2598 len = page->private >> 2;
2599 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2600 if (!eb)
2601 goto out;
2602
2603 btrfs_tree_lock(eb);
2604 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2605
2606 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2607 spin_lock(&root->fs_info->delalloc_lock);
2608 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2609 root->fs_info->dirty_metadata_bytes -= eb->len;
2610 else
2611 WARN_ON(1);
2612 spin_unlock(&root->fs_info->delalloc_lock);
2613 }
2614
2615 btrfs_tree_unlock(eb);
2616 free_extent_buffer(eb);
2617 out:
2618 lock_page(page);
2619 return 0;
2620 }
2621
2622 static struct extent_io_ops btree_extent_io_ops = {
2623 .write_cache_pages_lock_hook = btree_lock_page_hook,
2624 .readpage_end_io_hook = btree_readpage_end_io_hook,
2625 .submit_bio_hook = btree_submit_bio_hook,
2626 /* note we're sharing with inode.c for the merge bio hook */
2627 .merge_bio_hook = btrfs_merge_bio_hook,
2628 };
kernel source for telekom puls (alcatel/mediatek)