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[deliverable/linux.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 /*
48 * end_io_wq structs are used to do processing in task context when an IO is
49 * complete. This is used during reads to verify checksums, and it is used
50 * by writes to insert metadata for new file extents after IO is complete.
51 */
52 struct end_io_wq {
53 struct bio *bio;
54 bio_end_io_t *end_io;
55 void *private;
56 struct btrfs_fs_info *info;
57 int error;
58 int metadata;
59 struct list_head list;
60 struct btrfs_work work;
61 };
62
63 /*
64 * async submit bios are used to offload expensive checksumming
65 * onto the worker threads. They checksum file and metadata bios
66 * just before they are sent down the IO stack.
67 */
68 struct async_submit_bio {
69 struct inode *inode;
70 struct bio *bio;
71 struct list_head list;
72 extent_submit_bio_hook_t *submit_bio_start;
73 extent_submit_bio_hook_t *submit_bio_done;
74 int rw;
75 int mirror_num;
76 unsigned long bio_flags;
77 /*
78 * bio_offset is optional, can be used if the pages in the bio
79 * can't tell us where in the file the bio should go
80 */
81 u64 bio_offset;
82 struct btrfs_work work;
83 };
84
85 /* These are used to set the lockdep class on the extent buffer locks.
86 * The class is set by the readpage_end_io_hook after the buffer has
87 * passed csum validation but before the pages are unlocked.
88 *
89 * The lockdep class is also set by btrfs_init_new_buffer on freshly
90 * allocated blocks.
91 *
92 * The class is based on the level in the tree block, which allows lockdep
93 * to know that lower nodes nest inside the locks of higher nodes.
94 *
95 * We also add a check to make sure the highest level of the tree is
96 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
97 * code needs update as well.
98 */
99 #ifdef CONFIG_DEBUG_LOCK_ALLOC
100 # if BTRFS_MAX_LEVEL != 8
101 # error
102 # endif
103 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
104 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
105 /* leaf */
106 "btrfs-extent-00",
107 "btrfs-extent-01",
108 "btrfs-extent-02",
109 "btrfs-extent-03",
110 "btrfs-extent-04",
111 "btrfs-extent-05",
112 "btrfs-extent-06",
113 "btrfs-extent-07",
114 /* highest possible level */
115 "btrfs-extent-08",
116 };
117 #endif
118
119 /*
120 * extents on the btree inode are pretty simple, there's one extent
121 * that covers the entire device
122 */
123 static struct extent_map *btree_get_extent(struct inode *inode,
124 struct page *page, size_t page_offset, u64 start, u64 len,
125 int create)
126 {
127 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
128 struct extent_map *em;
129 int ret;
130
131 read_lock(&em_tree->lock);
132 em = lookup_extent_mapping(em_tree, start, len);
133 if (em) {
134 em->bdev =
135 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
136 read_unlock(&em_tree->lock);
137 goto out;
138 }
139 read_unlock(&em_tree->lock);
140
141 em = alloc_extent_map(GFP_NOFS);
142 if (!em) {
143 em = ERR_PTR(-ENOMEM);
144 goto out;
145 }
146 em->start = 0;
147 em->len = (u64)-1;
148 em->block_len = (u64)-1;
149 em->block_start = 0;
150 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
151
152 write_lock(&em_tree->lock);
153 ret = add_extent_mapping(em_tree, em);
154 if (ret == -EEXIST) {
155 u64 failed_start = em->start;
156 u64 failed_len = em->len;
157
158 free_extent_map(em);
159 em = lookup_extent_mapping(em_tree, start, len);
160 if (em) {
161 ret = 0;
162 } else {
163 em = lookup_extent_mapping(em_tree, failed_start,
164 failed_len);
165 ret = -EIO;
166 }
167 } else if (ret) {
168 free_extent_map(em);
169 em = NULL;
170 }
171 write_unlock(&em_tree->lock);
172
173 if (ret)
174 em = ERR_PTR(ret);
175 out:
176 return em;
177 }
178
179 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
180 {
181 return crc32c(seed, data, len);
182 }
183
184 void btrfs_csum_final(u32 crc, char *result)
185 {
186 *(__le32 *)result = ~cpu_to_le32(crc);
187 }
188
189 /*
190 * compute the csum for a btree block, and either verify it or write it
191 * into the csum field of the block.
192 */
193 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
194 int verify)
195 {
196 u16 csum_size =
197 btrfs_super_csum_size(&root->fs_info->super_copy);
198 char *result = NULL;
199 unsigned long len;
200 unsigned long cur_len;
201 unsigned long offset = BTRFS_CSUM_SIZE;
202 char *map_token = NULL;
203 char *kaddr;
204 unsigned long map_start;
205 unsigned long map_len;
206 int err;
207 u32 crc = ~(u32)0;
208 unsigned long inline_result;
209
210 len = buf->len - offset;
211 while (len > 0) {
212 err = map_private_extent_buffer(buf, offset, 32,
213 &map_token, &kaddr,
214 &map_start, &map_len, KM_USER0);
215 if (err)
216 return 1;
217 cur_len = min(len, map_len - (offset - map_start));
218 crc = btrfs_csum_data(root, kaddr + offset - map_start,
219 crc, cur_len);
220 len -= cur_len;
221 offset += cur_len;
222 unmap_extent_buffer(buf, map_token, KM_USER0);
223 }
224 if (csum_size > sizeof(inline_result)) {
225 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
226 if (!result)
227 return 1;
228 } else {
229 result = (char *)&inline_result;
230 }
231
232 btrfs_csum_final(crc, result);
233
234 if (verify) {
235 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
236 u32 val;
237 u32 found = 0;
238 memcpy(&found, result, csum_size);
239
240 read_extent_buffer(buf, &val, 0, csum_size);
241 if (printk_ratelimit()) {
242 printk(KERN_INFO "btrfs: %s checksum verify "
243 "failed on %llu wanted %X found %X "
244 "level %d\n",
245 root->fs_info->sb->s_id,
246 (unsigned long long)buf->start, val, found,
247 btrfs_header_level(buf));
248 }
249 if (result != (char *)&inline_result)
250 kfree(result);
251 return 1;
252 }
253 } else {
254 write_extent_buffer(buf, result, 0, csum_size);
255 }
256 if (result != (char *)&inline_result)
257 kfree(result);
258 return 0;
259 }
260
261 /*
262 * we can't consider a given block up to date unless the transid of the
263 * block matches the transid in the parent node's pointer. This is how we
264 * detect blocks that either didn't get written at all or got written
265 * in the wrong place.
266 */
267 static int verify_parent_transid(struct extent_io_tree *io_tree,
268 struct extent_buffer *eb, u64 parent_transid)
269 {
270 struct extent_state *cached_state = NULL;
271 int ret;
272
273 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
274 return 0;
275
276 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
277 0, &cached_state, GFP_NOFS);
278 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
279 btrfs_header_generation(eb) == parent_transid) {
280 ret = 0;
281 goto out;
282 }
283 if (printk_ratelimit()) {
284 printk("parent transid verify failed on %llu wanted %llu "
285 "found %llu\n",
286 (unsigned long long)eb->start,
287 (unsigned long long)parent_transid,
288 (unsigned long long)btrfs_header_generation(eb));
289 }
290 ret = 1;
291 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
292 out:
293 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
294 &cached_state, GFP_NOFS);
295 return ret;
296 }
297
298 /*
299 * helper to read a given tree block, doing retries as required when
300 * the checksums don't match and we have alternate mirrors to try.
301 */
302 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
303 struct extent_buffer *eb,
304 u64 start, u64 parent_transid)
305 {
306 struct extent_io_tree *io_tree;
307 int ret;
308 int num_copies = 0;
309 int mirror_num = 0;
310
311 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
312 while (1) {
313 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
314 btree_get_extent, mirror_num);
315 if (!ret &&
316 !verify_parent_transid(io_tree, eb, parent_transid))
317 return ret;
318
319 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
320 eb->start, eb->len);
321 if (num_copies == 1)
322 return ret;
323
324 mirror_num++;
325 if (mirror_num > num_copies)
326 return ret;
327 }
328 return -EIO;
329 }
330
331 /*
332 * checksum a dirty tree block before IO. This has extra checks to make sure
333 * we only fill in the checksum field in the first page of a multi-page block
334 */
335
336 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
337 {
338 struct extent_io_tree *tree;
339 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
340 u64 found_start;
341 int found_level;
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 found_start = btrfs_header_bytenr(eb);
360 if (found_start != start) {
361 WARN_ON(1);
362 goto err;
363 }
364 if (eb->first_page != page) {
365 WARN_ON(1);
366 goto err;
367 }
368 if (!PageUptodate(page)) {
369 WARN_ON(1);
370 goto err;
371 }
372 found_level = btrfs_header_level(eb);
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 btrfs_fs_info *fs_info;
547 struct async_submit_bio *async;
548
549 async = container_of(work, struct async_submit_bio, work);
550 fs_info = BTRFS_I(async->inode)->root->fs_info;
551 async->submit_bio_start(async->inode, async->rw, async->bio,
552 async->mirror_num, async->bio_flags,
553 async->bio_offset);
554 }
555
556 static void run_one_async_done(struct btrfs_work *work)
557 {
558 struct btrfs_fs_info *fs_info;
559 struct async_submit_bio *async;
560 int limit;
561
562 async = container_of(work, struct async_submit_bio, work);
563 fs_info = BTRFS_I(async->inode)->root->fs_info;
564
565 limit = btrfs_async_submit_limit(fs_info);
566 limit = limit * 2 / 3;
567
568 atomic_dec(&fs_info->nr_async_submits);
569
570 if (atomic_read(&fs_info->nr_async_submits) < limit &&
571 waitqueue_active(&fs_info->async_submit_wait))
572 wake_up(&fs_info->async_submit_wait);
573
574 async->submit_bio_done(async->inode, async->rw, async->bio,
575 async->mirror_num, async->bio_flags,
576 async->bio_offset);
577 }
578
579 static void run_one_async_free(struct btrfs_work *work)
580 {
581 struct async_submit_bio *async;
582
583 async = container_of(work, struct async_submit_bio, work);
584 kfree(async);
585 }
586
587 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
588 int rw, struct bio *bio, int mirror_num,
589 unsigned long bio_flags,
590 u64 bio_offset,
591 extent_submit_bio_hook_t *submit_bio_start,
592 extent_submit_bio_hook_t *submit_bio_done)
593 {
594 struct async_submit_bio *async;
595
596 async = kmalloc(sizeof(*async), GFP_NOFS);
597 if (!async)
598 return -ENOMEM;
599
600 async->inode = inode;
601 async->rw = rw;
602 async->bio = bio;
603 async->mirror_num = mirror_num;
604 async->submit_bio_start = submit_bio_start;
605 async->submit_bio_done = submit_bio_done;
606
607 async->work.func = run_one_async_start;
608 async->work.ordered_func = run_one_async_done;
609 async->work.ordered_free = run_one_async_free;
610
611 async->work.flags = 0;
612 async->bio_flags = bio_flags;
613 async->bio_offset = bio_offset;
614
615 atomic_inc(&fs_info->nr_async_submits);
616
617 if (rw & REQ_SYNC)
618 btrfs_set_work_high_prio(&async->work);
619
620 btrfs_queue_worker(&fs_info->workers, &async->work);
621
622 while (atomic_read(&fs_info->async_submit_draining) &&
623 atomic_read(&fs_info->nr_async_submits)) {
624 wait_event(fs_info->async_submit_wait,
625 (atomic_read(&fs_info->nr_async_submits) == 0));
626 }
627
628 return 0;
629 }
630
631 static int btree_csum_one_bio(struct bio *bio)
632 {
633 struct bio_vec *bvec = bio->bi_io_vec;
634 int bio_index = 0;
635 struct btrfs_root *root;
636
637 WARN_ON(bio->bi_vcnt <= 0);
638 while (bio_index < bio->bi_vcnt) {
639 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
640 csum_dirty_buffer(root, bvec->bv_page);
641 bio_index++;
642 bvec++;
643 }
644 return 0;
645 }
646
647 static int __btree_submit_bio_start(struct inode *inode, int rw,
648 struct bio *bio, int mirror_num,
649 unsigned long bio_flags,
650 u64 bio_offset)
651 {
652 /*
653 * when we're called for a write, we're already in the async
654 * submission context. Just jump into btrfs_map_bio
655 */
656 btree_csum_one_bio(bio);
657 return 0;
658 }
659
660 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
661 int mirror_num, unsigned long bio_flags,
662 u64 bio_offset)
663 {
664 /*
665 * when we're called for a write, we're already in the async
666 * submission context. Just jump into btrfs_map_bio
667 */
668 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
669 }
670
671 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
672 int mirror_num, unsigned long bio_flags,
673 u64 bio_offset)
674 {
675 int ret;
676
677 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
678 bio, 1);
679 BUG_ON(ret);
680
681 if (!(rw & REQ_WRITE)) {
682 /*
683 * called for a read, do the setup so that checksum validation
684 * can happen in the async kernel threads
685 */
686 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
687 mirror_num, 0);
688 }
689
690 /*
691 * kthread helpers are used to submit writes so that checksumming
692 * can happen in parallel across all CPUs
693 */
694 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
695 inode, rw, bio, mirror_num, 0,
696 bio_offset,
697 __btree_submit_bio_start,
698 __btree_submit_bio_done);
699 }
700
701 static int btree_writepage(struct page *page, struct writeback_control *wbc)
702 {
703 struct extent_io_tree *tree;
704 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
705 struct extent_buffer *eb;
706 int was_dirty;
707
708 tree = &BTRFS_I(page->mapping->host)->io_tree;
709 if (!(current->flags & PF_MEMALLOC)) {
710 return extent_write_full_page(tree, page,
711 btree_get_extent, wbc);
712 }
713
714 redirty_page_for_writepage(wbc, page);
715 eb = btrfs_find_tree_block(root, page_offset(page),
716 PAGE_CACHE_SIZE);
717 WARN_ON(!eb);
718
719 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
720 if (!was_dirty) {
721 spin_lock(&root->fs_info->delalloc_lock);
722 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
723 spin_unlock(&root->fs_info->delalloc_lock);
724 }
725 free_extent_buffer(eb);
726
727 unlock_page(page);
728 return 0;
729 }
730
731 static int btree_writepages(struct address_space *mapping,
732 struct writeback_control *wbc)
733 {
734 struct extent_io_tree *tree;
735 tree = &BTRFS_I(mapping->host)->io_tree;
736 if (wbc->sync_mode == WB_SYNC_NONE) {
737 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
738 u64 num_dirty;
739 unsigned long thresh = 32 * 1024 * 1024;
740
741 if (wbc->for_kupdate)
742 return 0;
743
744 /* this is a bit racy, but that's ok */
745 num_dirty = root->fs_info->dirty_metadata_bytes;
746 if (num_dirty < thresh)
747 return 0;
748 }
749 return extent_writepages(tree, mapping, btree_get_extent, wbc);
750 }
751
752 static int btree_readpage(struct file *file, struct page *page)
753 {
754 struct extent_io_tree *tree;
755 tree = &BTRFS_I(page->mapping->host)->io_tree;
756 return extent_read_full_page(tree, page, btree_get_extent);
757 }
758
759 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
760 {
761 struct extent_io_tree *tree;
762 struct extent_map_tree *map;
763 int ret;
764
765 if (PageWriteback(page) || PageDirty(page))
766 return 0;
767
768 tree = &BTRFS_I(page->mapping->host)->io_tree;
769 map = &BTRFS_I(page->mapping->host)->extent_tree;
770
771 ret = try_release_extent_state(map, tree, page, gfp_flags);
772 if (!ret)
773 return 0;
774
775 ret = try_release_extent_buffer(tree, page);
776 if (ret == 1) {
777 ClearPagePrivate(page);
778 set_page_private(page, 0);
779 page_cache_release(page);
780 }
781
782 return ret;
783 }
784
785 static void btree_invalidatepage(struct page *page, unsigned long offset)
786 {
787 struct extent_io_tree *tree;
788 tree = &BTRFS_I(page->mapping->host)->io_tree;
789 extent_invalidatepage(tree, page, offset);
790 btree_releasepage(page, GFP_NOFS);
791 if (PagePrivate(page)) {
792 printk(KERN_WARNING "btrfs warning page private not zero "
793 "on page %llu\n", (unsigned long long)page_offset(page));
794 ClearPagePrivate(page);
795 set_page_private(page, 0);
796 page_cache_release(page);
797 }
798 }
799
800 static const struct address_space_operations btree_aops = {
801 .readpage = btree_readpage,
802 .writepage = btree_writepage,
803 .writepages = btree_writepages,
804 .releasepage = btree_releasepage,
805 .invalidatepage = btree_invalidatepage,
806 .sync_page = block_sync_page,
807 };
808
809 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
810 u64 parent_transid)
811 {
812 struct extent_buffer *buf = NULL;
813 struct inode *btree_inode = root->fs_info->btree_inode;
814 int ret = 0;
815
816 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
817 if (!buf)
818 return 0;
819 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
820 buf, 0, 0, btree_get_extent, 0);
821 free_extent_buffer(buf);
822 return ret;
823 }
824
825 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
826 u64 bytenr, u32 blocksize)
827 {
828 struct inode *btree_inode = root->fs_info->btree_inode;
829 struct extent_buffer *eb;
830 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
831 bytenr, blocksize, GFP_NOFS);
832 return eb;
833 }
834
835 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
836 u64 bytenr, u32 blocksize)
837 {
838 struct inode *btree_inode = root->fs_info->btree_inode;
839 struct extent_buffer *eb;
840
841 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
842 bytenr, blocksize, NULL, GFP_NOFS);
843 return eb;
844 }
845
846
847 int btrfs_write_tree_block(struct extent_buffer *buf)
848 {
849 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
850 buf->start + buf->len - 1);
851 }
852
853 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
854 {
855 return filemap_fdatawait_range(buf->first_page->mapping,
856 buf->start, buf->start + buf->len - 1);
857 }
858
859 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
860 u32 blocksize, u64 parent_transid)
861 {
862 struct extent_buffer *buf = NULL;
863 struct inode *btree_inode = root->fs_info->btree_inode;
864 struct extent_io_tree *io_tree;
865 int ret;
866
867 io_tree = &BTRFS_I(btree_inode)->io_tree;
868
869 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
870 if (!buf)
871 return NULL;
872
873 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
874
875 if (ret == 0)
876 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
877 return buf;
878
879 }
880
881 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
882 struct extent_buffer *buf)
883 {
884 struct inode *btree_inode = root->fs_info->btree_inode;
885 if (btrfs_header_generation(buf) ==
886 root->fs_info->running_transaction->transid) {
887 btrfs_assert_tree_locked(buf);
888
889 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
890 spin_lock(&root->fs_info->delalloc_lock);
891 if (root->fs_info->dirty_metadata_bytes >= buf->len)
892 root->fs_info->dirty_metadata_bytes -= buf->len;
893 else
894 WARN_ON(1);
895 spin_unlock(&root->fs_info->delalloc_lock);
896 }
897
898 /* ugh, clear_extent_buffer_dirty needs to lock the page */
899 btrfs_set_lock_blocking(buf);
900 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
901 buf);
902 }
903 return 0;
904 }
905
906 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
907 u32 stripesize, struct btrfs_root *root,
908 struct btrfs_fs_info *fs_info,
909 u64 objectid)
910 {
911 root->node = NULL;
912 root->commit_root = NULL;
913 root->sectorsize = sectorsize;
914 root->nodesize = nodesize;
915 root->leafsize = leafsize;
916 root->stripesize = stripesize;
917 root->ref_cows = 0;
918 root->track_dirty = 0;
919 root->in_radix = 0;
920 root->orphan_item_inserted = 0;
921 root->orphan_cleanup_state = 0;
922
923 root->fs_info = fs_info;
924 root->objectid = objectid;
925 root->last_trans = 0;
926 root->highest_objectid = 0;
927 root->name = NULL;
928 root->in_sysfs = 0;
929 root->inode_tree = RB_ROOT;
930 root->block_rsv = NULL;
931 root->orphan_block_rsv = NULL;
932
933 INIT_LIST_HEAD(&root->dirty_list);
934 INIT_LIST_HEAD(&root->orphan_list);
935 INIT_LIST_HEAD(&root->root_list);
936 spin_lock_init(&root->node_lock);
937 spin_lock_init(&root->orphan_lock);
938 spin_lock_init(&root->inode_lock);
939 spin_lock_init(&root->accounting_lock);
940 mutex_init(&root->objectid_mutex);
941 mutex_init(&root->log_mutex);
942 init_waitqueue_head(&root->log_writer_wait);
943 init_waitqueue_head(&root->log_commit_wait[0]);
944 init_waitqueue_head(&root->log_commit_wait[1]);
945 atomic_set(&root->log_commit[0], 0);
946 atomic_set(&root->log_commit[1], 0);
947 atomic_set(&root->log_writers, 0);
948 root->log_batch = 0;
949 root->log_transid = 0;
950 root->last_log_commit = 0;
951 extent_io_tree_init(&root->dirty_log_pages,
952 fs_info->btree_inode->i_mapping, GFP_NOFS);
953
954 memset(&root->root_key, 0, sizeof(root->root_key));
955 memset(&root->root_item, 0, sizeof(root->root_item));
956 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
957 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
958 root->defrag_trans_start = fs_info->generation;
959 init_completion(&root->kobj_unregister);
960 root->defrag_running = 0;
961 root->root_key.objectid = objectid;
962 root->anon_super.s_root = NULL;
963 root->anon_super.s_dev = 0;
964 INIT_LIST_HEAD(&root->anon_super.s_list);
965 INIT_LIST_HEAD(&root->anon_super.s_instances);
966 init_rwsem(&root->anon_super.s_umount);
967
968 return 0;
969 }
970
971 static int find_and_setup_root(struct btrfs_root *tree_root,
972 struct btrfs_fs_info *fs_info,
973 u64 objectid,
974 struct btrfs_root *root)
975 {
976 int ret;
977 u32 blocksize;
978 u64 generation;
979
980 __setup_root(tree_root->nodesize, tree_root->leafsize,
981 tree_root->sectorsize, tree_root->stripesize,
982 root, fs_info, objectid);
983 ret = btrfs_find_last_root(tree_root, objectid,
984 &root->root_item, &root->root_key);
985 if (ret > 0)
986 return -ENOENT;
987 BUG_ON(ret);
988
989 generation = btrfs_root_generation(&root->root_item);
990 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
991 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
992 blocksize, generation);
993 BUG_ON(!root->node);
994 root->commit_root = btrfs_root_node(root);
995 return 0;
996 }
997
998 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
999 struct btrfs_fs_info *fs_info)
1000 {
1001 struct btrfs_root *root;
1002 struct btrfs_root *tree_root = fs_info->tree_root;
1003 struct extent_buffer *leaf;
1004
1005 root = kzalloc(sizeof(*root), GFP_NOFS);
1006 if (!root)
1007 return ERR_PTR(-ENOMEM);
1008
1009 __setup_root(tree_root->nodesize, tree_root->leafsize,
1010 tree_root->sectorsize, tree_root->stripesize,
1011 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1012
1013 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1014 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1015 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1016 /*
1017 * log trees do not get reference counted because they go away
1018 * before a real commit is actually done. They do store pointers
1019 * to file data extents, and those reference counts still get
1020 * updated (along with back refs to the log tree).
1021 */
1022 root->ref_cows = 0;
1023
1024 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1025 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1026 if (IS_ERR(leaf)) {
1027 kfree(root);
1028 return ERR_CAST(leaf);
1029 }
1030
1031 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1032 btrfs_set_header_bytenr(leaf, leaf->start);
1033 btrfs_set_header_generation(leaf, trans->transid);
1034 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1035 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1036 root->node = leaf;
1037
1038 write_extent_buffer(root->node, root->fs_info->fsid,
1039 (unsigned long)btrfs_header_fsid(root->node),
1040 BTRFS_FSID_SIZE);
1041 btrfs_mark_buffer_dirty(root->node);
1042 btrfs_tree_unlock(root->node);
1043 return root;
1044 }
1045
1046 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1047 struct btrfs_fs_info *fs_info)
1048 {
1049 struct btrfs_root *log_root;
1050
1051 log_root = alloc_log_tree(trans, fs_info);
1052 if (IS_ERR(log_root))
1053 return PTR_ERR(log_root);
1054 WARN_ON(fs_info->log_root_tree);
1055 fs_info->log_root_tree = log_root;
1056 return 0;
1057 }
1058
1059 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1060 struct btrfs_root *root)
1061 {
1062 struct btrfs_root *log_root;
1063 struct btrfs_inode_item *inode_item;
1064
1065 log_root = alloc_log_tree(trans, root->fs_info);
1066 if (IS_ERR(log_root))
1067 return PTR_ERR(log_root);
1068
1069 log_root->last_trans = trans->transid;
1070 log_root->root_key.offset = root->root_key.objectid;
1071
1072 inode_item = &log_root->root_item.inode;
1073 inode_item->generation = cpu_to_le64(1);
1074 inode_item->size = cpu_to_le64(3);
1075 inode_item->nlink = cpu_to_le32(1);
1076 inode_item->nbytes = cpu_to_le64(root->leafsize);
1077 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1078
1079 btrfs_set_root_node(&log_root->root_item, log_root->node);
1080
1081 WARN_ON(root->log_root);
1082 root->log_root = log_root;
1083 root->log_transid = 0;
1084 root->last_log_commit = 0;
1085 return 0;
1086 }
1087
1088 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1089 struct btrfs_key *location)
1090 {
1091 struct btrfs_root *root;
1092 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1093 struct btrfs_path *path;
1094 struct extent_buffer *l;
1095 u64 generation;
1096 u32 blocksize;
1097 int ret = 0;
1098
1099 root = kzalloc(sizeof(*root), GFP_NOFS);
1100 if (!root)
1101 return ERR_PTR(-ENOMEM);
1102 if (location->offset == (u64)-1) {
1103 ret = find_and_setup_root(tree_root, fs_info,
1104 location->objectid, root);
1105 if (ret) {
1106 kfree(root);
1107 return ERR_PTR(ret);
1108 }
1109 goto out;
1110 }
1111
1112 __setup_root(tree_root->nodesize, tree_root->leafsize,
1113 tree_root->sectorsize, tree_root->stripesize,
1114 root, fs_info, location->objectid);
1115
1116 path = btrfs_alloc_path();
1117 BUG_ON(!path);
1118 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1119 if (ret == 0) {
1120 l = path->nodes[0];
1121 read_extent_buffer(l, &root->root_item,
1122 btrfs_item_ptr_offset(l, path->slots[0]),
1123 sizeof(root->root_item));
1124 memcpy(&root->root_key, location, sizeof(*location));
1125 }
1126 btrfs_free_path(path);
1127 if (ret) {
1128 if (ret > 0)
1129 ret = -ENOENT;
1130 return ERR_PTR(ret);
1131 }
1132
1133 generation = btrfs_root_generation(&root->root_item);
1134 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1135 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1136 blocksize, generation);
1137 root->commit_root = btrfs_root_node(root);
1138 BUG_ON(!root->node);
1139 out:
1140 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1141 root->ref_cows = 1;
1142
1143 return root;
1144 }
1145
1146 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1147 u64 root_objectid)
1148 {
1149 struct btrfs_root *root;
1150
1151 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1152 return fs_info->tree_root;
1153 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1154 return fs_info->extent_root;
1155
1156 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1157 (unsigned long)root_objectid);
1158 return root;
1159 }
1160
1161 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1162 struct btrfs_key *location)
1163 {
1164 struct btrfs_root *root;
1165 int ret;
1166
1167 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1168 return fs_info->tree_root;
1169 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1170 return fs_info->extent_root;
1171 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1172 return fs_info->chunk_root;
1173 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1174 return fs_info->dev_root;
1175 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1176 return fs_info->csum_root;
1177 again:
1178 spin_lock(&fs_info->fs_roots_radix_lock);
1179 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1180 (unsigned long)location->objectid);
1181 spin_unlock(&fs_info->fs_roots_radix_lock);
1182 if (root)
1183 return root;
1184
1185 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1186 if (IS_ERR(root))
1187 return root;
1188
1189 set_anon_super(&root->anon_super, NULL);
1190
1191 if (btrfs_root_refs(&root->root_item) == 0) {
1192 ret = -ENOENT;
1193 goto fail;
1194 }
1195
1196 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1197 if (ret < 0)
1198 goto fail;
1199 if (ret == 0)
1200 root->orphan_item_inserted = 1;
1201
1202 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1203 if (ret)
1204 goto fail;
1205
1206 spin_lock(&fs_info->fs_roots_radix_lock);
1207 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1208 (unsigned long)root->root_key.objectid,
1209 root);
1210 if (ret == 0)
1211 root->in_radix = 1;
1212
1213 spin_unlock(&fs_info->fs_roots_radix_lock);
1214 radix_tree_preload_end();
1215 if (ret) {
1216 if (ret == -EEXIST) {
1217 free_fs_root(root);
1218 goto again;
1219 }
1220 goto fail;
1221 }
1222
1223 ret = btrfs_find_dead_roots(fs_info->tree_root,
1224 root->root_key.objectid);
1225 WARN_ON(ret);
1226 return root;
1227 fail:
1228 free_fs_root(root);
1229 return ERR_PTR(ret);
1230 }
1231
1232 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1233 struct btrfs_key *location,
1234 const char *name, int namelen)
1235 {
1236 return btrfs_read_fs_root_no_name(fs_info, location);
1237 #if 0
1238 struct btrfs_root *root;
1239 int ret;
1240
1241 root = btrfs_read_fs_root_no_name(fs_info, location);
1242 if (!root)
1243 return NULL;
1244
1245 if (root->in_sysfs)
1246 return root;
1247
1248 ret = btrfs_set_root_name(root, name, namelen);
1249 if (ret) {
1250 free_extent_buffer(root->node);
1251 kfree(root);
1252 return ERR_PTR(ret);
1253 }
1254
1255 ret = btrfs_sysfs_add_root(root);
1256 if (ret) {
1257 free_extent_buffer(root->node);
1258 kfree(root->name);
1259 kfree(root);
1260 return ERR_PTR(ret);
1261 }
1262 root->in_sysfs = 1;
1263 return root;
1264 #endif
1265 }
1266
1267 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1268 {
1269 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1270 int ret = 0;
1271 struct btrfs_device *device;
1272 struct backing_dev_info *bdi;
1273
1274 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1275 if (!device->bdev)
1276 continue;
1277 bdi = blk_get_backing_dev_info(device->bdev);
1278 if (bdi && bdi_congested(bdi, bdi_bits)) {
1279 ret = 1;
1280 break;
1281 }
1282 }
1283 return ret;
1284 }
1285
1286 /*
1287 * this unplugs every device on the box, and it is only used when page
1288 * is null
1289 */
1290 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1291 {
1292 struct btrfs_device *device;
1293 struct btrfs_fs_info *info;
1294
1295 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1296 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1297 if (!device->bdev)
1298 continue;
1299
1300 bdi = blk_get_backing_dev_info(device->bdev);
1301 if (bdi->unplug_io_fn)
1302 bdi->unplug_io_fn(bdi, page);
1303 }
1304 }
1305
1306 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1307 {
1308 struct inode *inode;
1309 struct extent_map_tree *em_tree;
1310 struct extent_map *em;
1311 struct address_space *mapping;
1312 u64 offset;
1313
1314 /* the generic O_DIRECT read code does this */
1315 if (1 || !page) {
1316 __unplug_io_fn(bdi, page);
1317 return;
1318 }
1319
1320 /*
1321 * page->mapping may change at any time. Get a consistent copy
1322 * and use that for everything below
1323 */
1324 smp_mb();
1325 mapping = page->mapping;
1326 if (!mapping)
1327 return;
1328
1329 inode = mapping->host;
1330
1331 /*
1332 * don't do the expensive searching for a small number of
1333 * devices
1334 */
1335 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1336 __unplug_io_fn(bdi, page);
1337 return;
1338 }
1339
1340 offset = page_offset(page);
1341
1342 em_tree = &BTRFS_I(inode)->extent_tree;
1343 read_lock(&em_tree->lock);
1344 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1345 read_unlock(&em_tree->lock);
1346 if (!em) {
1347 __unplug_io_fn(bdi, page);
1348 return;
1349 }
1350
1351 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1352 free_extent_map(em);
1353 __unplug_io_fn(bdi, page);
1354 return;
1355 }
1356 offset = offset - em->start;
1357 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1358 em->block_start + offset, page);
1359 free_extent_map(em);
1360 }
1361
1362 /*
1363 * If this fails, caller must call bdi_destroy() to get rid of the
1364 * bdi again.
1365 */
1366 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1367 {
1368 int err;
1369
1370 bdi->capabilities = BDI_CAP_MAP_COPY;
1371 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1372 if (err)
1373 return err;
1374
1375 bdi->ra_pages = default_backing_dev_info.ra_pages;
1376 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1377 bdi->unplug_io_data = info;
1378 bdi->congested_fn = btrfs_congested_fn;
1379 bdi->congested_data = info;
1380 return 0;
1381 }
1382
1383 static int bio_ready_for_csum(struct bio *bio)
1384 {
1385 u64 length = 0;
1386 u64 buf_len = 0;
1387 u64 start = 0;
1388 struct page *page;
1389 struct extent_io_tree *io_tree = NULL;
1390 struct btrfs_fs_info *info = NULL;
1391 struct bio_vec *bvec;
1392 int i;
1393 int ret;
1394
1395 bio_for_each_segment(bvec, bio, i) {
1396 page = bvec->bv_page;
1397 if (page->private == EXTENT_PAGE_PRIVATE) {
1398 length += bvec->bv_len;
1399 continue;
1400 }
1401 if (!page->private) {
1402 length += bvec->bv_len;
1403 continue;
1404 }
1405 length = bvec->bv_len;
1406 buf_len = page->private >> 2;
1407 start = page_offset(page) + bvec->bv_offset;
1408 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1409 info = BTRFS_I(page->mapping->host)->root->fs_info;
1410 }
1411 /* are we fully contained in this bio? */
1412 if (buf_len <= length)
1413 return 1;
1414
1415 ret = extent_range_uptodate(io_tree, start + length,
1416 start + buf_len - 1);
1417 return ret;
1418 }
1419
1420 /*
1421 * called by the kthread helper functions to finally call the bio end_io
1422 * functions. This is where read checksum verification actually happens
1423 */
1424 static void end_workqueue_fn(struct btrfs_work *work)
1425 {
1426 struct bio *bio;
1427 struct end_io_wq *end_io_wq;
1428 struct btrfs_fs_info *fs_info;
1429 int error;
1430
1431 end_io_wq = container_of(work, struct end_io_wq, work);
1432 bio = end_io_wq->bio;
1433 fs_info = end_io_wq->info;
1434
1435 /* metadata bio reads are special because the whole tree block must
1436 * be checksummed at once. This makes sure the entire block is in
1437 * ram and up to date before trying to verify things. For
1438 * blocksize <= pagesize, it is basically a noop
1439 */
1440 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1441 !bio_ready_for_csum(bio)) {
1442 btrfs_queue_worker(&fs_info->endio_meta_workers,
1443 &end_io_wq->work);
1444 return;
1445 }
1446 error = end_io_wq->error;
1447 bio->bi_private = end_io_wq->private;
1448 bio->bi_end_io = end_io_wq->end_io;
1449 kfree(end_io_wq);
1450 bio_endio(bio, error);
1451 }
1452
1453 static int cleaner_kthread(void *arg)
1454 {
1455 struct btrfs_root *root = arg;
1456
1457 do {
1458 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1459
1460 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1461 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1462 btrfs_run_delayed_iputs(root);
1463 btrfs_clean_old_snapshots(root);
1464 mutex_unlock(&root->fs_info->cleaner_mutex);
1465 }
1466
1467 if (freezing(current)) {
1468 refrigerator();
1469 } else {
1470 set_current_state(TASK_INTERRUPTIBLE);
1471 if (!kthread_should_stop())
1472 schedule();
1473 __set_current_state(TASK_RUNNING);
1474 }
1475 } while (!kthread_should_stop());
1476 return 0;
1477 }
1478
1479 static int transaction_kthread(void *arg)
1480 {
1481 struct btrfs_root *root = arg;
1482 struct btrfs_trans_handle *trans;
1483 struct btrfs_transaction *cur;
1484 u64 transid;
1485 unsigned long now;
1486 unsigned long delay;
1487 int ret;
1488
1489 do {
1490 delay = HZ * 30;
1491 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1492 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1493
1494 spin_lock(&root->fs_info->new_trans_lock);
1495 cur = root->fs_info->running_transaction;
1496 if (!cur) {
1497 spin_unlock(&root->fs_info->new_trans_lock);
1498 goto sleep;
1499 }
1500
1501 now = get_seconds();
1502 if (!cur->blocked &&
1503 (now < cur->start_time || now - cur->start_time < 30)) {
1504 spin_unlock(&root->fs_info->new_trans_lock);
1505 delay = HZ * 5;
1506 goto sleep;
1507 }
1508 transid = cur->transid;
1509 spin_unlock(&root->fs_info->new_trans_lock);
1510
1511 trans = btrfs_join_transaction(root, 1);
1512 if (transid == trans->transid) {
1513 ret = btrfs_commit_transaction(trans, root);
1514 BUG_ON(ret);
1515 } else {
1516 btrfs_end_transaction(trans, root);
1517 }
1518 sleep:
1519 wake_up_process(root->fs_info->cleaner_kthread);
1520 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1521
1522 if (freezing(current)) {
1523 refrigerator();
1524 } else {
1525 set_current_state(TASK_INTERRUPTIBLE);
1526 if (!kthread_should_stop() &&
1527 !btrfs_transaction_blocked(root->fs_info))
1528 schedule_timeout(delay);
1529 __set_current_state(TASK_RUNNING);
1530 }
1531 } while (!kthread_should_stop());
1532 return 0;
1533 }
1534
1535 struct btrfs_root *open_ctree(struct super_block *sb,
1536 struct btrfs_fs_devices *fs_devices,
1537 char *options)
1538 {
1539 u32 sectorsize;
1540 u32 nodesize;
1541 u32 leafsize;
1542 u32 blocksize;
1543 u32 stripesize;
1544 u64 generation;
1545 u64 features;
1546 struct btrfs_key location;
1547 struct buffer_head *bh;
1548 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1549 GFP_NOFS);
1550 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1551 GFP_NOFS);
1552 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1553 GFP_NOFS);
1554 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1555 GFP_NOFS);
1556 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1557 GFP_NOFS);
1558 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1559 GFP_NOFS);
1560 struct btrfs_root *log_tree_root;
1561
1562 int ret;
1563 int err = -EINVAL;
1564
1565 struct btrfs_super_block *disk_super;
1566
1567 if (!extent_root || !tree_root || !fs_info ||
1568 !chunk_root || !dev_root || !csum_root) {
1569 err = -ENOMEM;
1570 goto fail;
1571 }
1572
1573 ret = init_srcu_struct(&fs_info->subvol_srcu);
1574 if (ret) {
1575 err = ret;
1576 goto fail;
1577 }
1578
1579 ret = setup_bdi(fs_info, &fs_info->bdi);
1580 if (ret) {
1581 err = ret;
1582 goto fail_srcu;
1583 }
1584
1585 fs_info->btree_inode = new_inode(sb);
1586 if (!fs_info->btree_inode) {
1587 err = -ENOMEM;
1588 goto fail_bdi;
1589 }
1590
1591 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1592 INIT_LIST_HEAD(&fs_info->trans_list);
1593 INIT_LIST_HEAD(&fs_info->dead_roots);
1594 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1595 INIT_LIST_HEAD(&fs_info->hashers);
1596 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1597 INIT_LIST_HEAD(&fs_info->ordered_operations);
1598 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1599 spin_lock_init(&fs_info->delalloc_lock);
1600 spin_lock_init(&fs_info->new_trans_lock);
1601 spin_lock_init(&fs_info->ref_cache_lock);
1602 spin_lock_init(&fs_info->fs_roots_radix_lock);
1603 spin_lock_init(&fs_info->delayed_iput_lock);
1604
1605 init_completion(&fs_info->kobj_unregister);
1606 fs_info->tree_root = tree_root;
1607 fs_info->extent_root = extent_root;
1608 fs_info->csum_root = csum_root;
1609 fs_info->chunk_root = chunk_root;
1610 fs_info->dev_root = dev_root;
1611 fs_info->fs_devices = fs_devices;
1612 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1613 INIT_LIST_HEAD(&fs_info->space_info);
1614 btrfs_mapping_init(&fs_info->mapping_tree);
1615 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1616 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1617 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1618 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1619 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1620 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1621 mutex_init(&fs_info->durable_block_rsv_mutex);
1622 atomic_set(&fs_info->nr_async_submits, 0);
1623 atomic_set(&fs_info->async_delalloc_pages, 0);
1624 atomic_set(&fs_info->async_submit_draining, 0);
1625 atomic_set(&fs_info->nr_async_bios, 0);
1626 fs_info->sb = sb;
1627 fs_info->max_inline = 8192 * 1024;
1628 fs_info->metadata_ratio = 0;
1629
1630 fs_info->thread_pool_size = min_t(unsigned long,
1631 num_online_cpus() + 2, 8);
1632
1633 INIT_LIST_HEAD(&fs_info->ordered_extents);
1634 spin_lock_init(&fs_info->ordered_extent_lock);
1635
1636 sb->s_blocksize = 4096;
1637 sb->s_blocksize_bits = blksize_bits(4096);
1638 sb->s_bdi = &fs_info->bdi;
1639
1640 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1641 fs_info->btree_inode->i_nlink = 1;
1642 /*
1643 * we set the i_size on the btree inode to the max possible int.
1644 * the real end of the address space is determined by all of
1645 * the devices in the system
1646 */
1647 fs_info->btree_inode->i_size = OFFSET_MAX;
1648 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1649 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1650
1651 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1652 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1653 fs_info->btree_inode->i_mapping,
1654 GFP_NOFS);
1655 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1656 GFP_NOFS);
1657
1658 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1659
1660 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1661 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1662 sizeof(struct btrfs_key));
1663 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1664 insert_inode_hash(fs_info->btree_inode);
1665
1666 spin_lock_init(&fs_info->block_group_cache_lock);
1667 fs_info->block_group_cache_tree = RB_ROOT;
1668
1669 extent_io_tree_init(&fs_info->freed_extents[0],
1670 fs_info->btree_inode->i_mapping, GFP_NOFS);
1671 extent_io_tree_init(&fs_info->freed_extents[1],
1672 fs_info->btree_inode->i_mapping, GFP_NOFS);
1673 fs_info->pinned_extents = &fs_info->freed_extents[0];
1674 fs_info->do_barriers = 1;
1675
1676
1677 mutex_init(&fs_info->trans_mutex);
1678 mutex_init(&fs_info->ordered_operations_mutex);
1679 mutex_init(&fs_info->tree_log_mutex);
1680 mutex_init(&fs_info->chunk_mutex);
1681 mutex_init(&fs_info->transaction_kthread_mutex);
1682 mutex_init(&fs_info->cleaner_mutex);
1683 mutex_init(&fs_info->volume_mutex);
1684 init_rwsem(&fs_info->extent_commit_sem);
1685 init_rwsem(&fs_info->cleanup_work_sem);
1686 init_rwsem(&fs_info->subvol_sem);
1687
1688 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1689 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1690
1691 init_waitqueue_head(&fs_info->transaction_throttle);
1692 init_waitqueue_head(&fs_info->transaction_wait);
1693 init_waitqueue_head(&fs_info->async_submit_wait);
1694
1695 __setup_root(4096, 4096, 4096, 4096, tree_root,
1696 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1697
1698 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1699 if (!bh)
1700 goto fail_iput;
1701
1702 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1703 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1704 sizeof(fs_info->super_for_commit));
1705 brelse(bh);
1706
1707 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1708
1709 disk_super = &fs_info->super_copy;
1710 if (!btrfs_super_root(disk_super))
1711 goto fail_iput;
1712
1713 ret = btrfs_parse_options(tree_root, options);
1714 if (ret) {
1715 err = ret;
1716 goto fail_iput;
1717 }
1718
1719 features = btrfs_super_incompat_flags(disk_super) &
1720 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1721 if (features) {
1722 printk(KERN_ERR "BTRFS: couldn't mount because of "
1723 "unsupported optional features (%Lx).\n",
1724 (unsigned long long)features);
1725 err = -EINVAL;
1726 goto fail_iput;
1727 }
1728
1729 features = btrfs_super_incompat_flags(disk_super);
1730 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1731 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1732 btrfs_set_super_incompat_flags(disk_super, features);
1733 }
1734
1735 features = btrfs_super_compat_ro_flags(disk_super) &
1736 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1737 if (!(sb->s_flags & MS_RDONLY) && features) {
1738 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1739 "unsupported option features (%Lx).\n",
1740 (unsigned long long)features);
1741 err = -EINVAL;
1742 goto fail_iput;
1743 }
1744
1745 btrfs_init_workers(&fs_info->generic_worker,
1746 "genwork", 1, NULL);
1747
1748 btrfs_init_workers(&fs_info->workers, "worker",
1749 fs_info->thread_pool_size,
1750 &fs_info->generic_worker);
1751
1752 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1753 fs_info->thread_pool_size,
1754 &fs_info->generic_worker);
1755
1756 btrfs_init_workers(&fs_info->submit_workers, "submit",
1757 min_t(u64, fs_devices->num_devices,
1758 fs_info->thread_pool_size),
1759 &fs_info->generic_worker);
1760
1761 /* a higher idle thresh on the submit workers makes it much more
1762 * likely that bios will be send down in a sane order to the
1763 * devices
1764 */
1765 fs_info->submit_workers.idle_thresh = 64;
1766
1767 fs_info->workers.idle_thresh = 16;
1768 fs_info->workers.ordered = 1;
1769
1770 fs_info->delalloc_workers.idle_thresh = 2;
1771 fs_info->delalloc_workers.ordered = 1;
1772
1773 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1774 &fs_info->generic_worker);
1775 btrfs_init_workers(&fs_info->endio_workers, "endio",
1776 fs_info->thread_pool_size,
1777 &fs_info->generic_worker);
1778 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1779 fs_info->thread_pool_size,
1780 &fs_info->generic_worker);
1781 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1782 "endio-meta-write", fs_info->thread_pool_size,
1783 &fs_info->generic_worker);
1784 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1785 fs_info->thread_pool_size,
1786 &fs_info->generic_worker);
1787 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1788 1, &fs_info->generic_worker);
1789
1790 /*
1791 * endios are largely parallel and should have a very
1792 * low idle thresh
1793 */
1794 fs_info->endio_workers.idle_thresh = 4;
1795 fs_info->endio_meta_workers.idle_thresh = 4;
1796
1797 fs_info->endio_write_workers.idle_thresh = 2;
1798 fs_info->endio_meta_write_workers.idle_thresh = 2;
1799
1800 btrfs_start_workers(&fs_info->workers, 1);
1801 btrfs_start_workers(&fs_info->generic_worker, 1);
1802 btrfs_start_workers(&fs_info->submit_workers, 1);
1803 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1804 btrfs_start_workers(&fs_info->fixup_workers, 1);
1805 btrfs_start_workers(&fs_info->endio_workers, 1);
1806 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1807 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1808 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1809 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1810
1811 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1812 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1813 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1814
1815 nodesize = btrfs_super_nodesize(disk_super);
1816 leafsize = btrfs_super_leafsize(disk_super);
1817 sectorsize = btrfs_super_sectorsize(disk_super);
1818 stripesize = btrfs_super_stripesize(disk_super);
1819 tree_root->nodesize = nodesize;
1820 tree_root->leafsize = leafsize;
1821 tree_root->sectorsize = sectorsize;
1822 tree_root->stripesize = stripesize;
1823
1824 sb->s_blocksize = sectorsize;
1825 sb->s_blocksize_bits = blksize_bits(sectorsize);
1826
1827 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1828 sizeof(disk_super->magic))) {
1829 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1830 goto fail_sb_buffer;
1831 }
1832
1833 mutex_lock(&fs_info->chunk_mutex);
1834 ret = btrfs_read_sys_array(tree_root);
1835 mutex_unlock(&fs_info->chunk_mutex);
1836 if (ret) {
1837 printk(KERN_WARNING "btrfs: failed to read the system "
1838 "array on %s\n", sb->s_id);
1839 goto fail_sb_buffer;
1840 }
1841
1842 blocksize = btrfs_level_size(tree_root,
1843 btrfs_super_chunk_root_level(disk_super));
1844 generation = btrfs_super_chunk_root_generation(disk_super);
1845
1846 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1847 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1848
1849 chunk_root->node = read_tree_block(chunk_root,
1850 btrfs_super_chunk_root(disk_super),
1851 blocksize, generation);
1852 BUG_ON(!chunk_root->node);
1853 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1854 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1855 sb->s_id);
1856 goto fail_chunk_root;
1857 }
1858 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1859 chunk_root->commit_root = btrfs_root_node(chunk_root);
1860
1861 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1862 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1863 BTRFS_UUID_SIZE);
1864
1865 mutex_lock(&fs_info->chunk_mutex);
1866 ret = btrfs_read_chunk_tree(chunk_root);
1867 mutex_unlock(&fs_info->chunk_mutex);
1868 if (ret) {
1869 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1870 sb->s_id);
1871 goto fail_chunk_root;
1872 }
1873
1874 btrfs_close_extra_devices(fs_devices);
1875
1876 blocksize = btrfs_level_size(tree_root,
1877 btrfs_super_root_level(disk_super));
1878 generation = btrfs_super_generation(disk_super);
1879
1880 tree_root->node = read_tree_block(tree_root,
1881 btrfs_super_root(disk_super),
1882 blocksize, generation);
1883 if (!tree_root->node)
1884 goto fail_chunk_root;
1885 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1886 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1887 sb->s_id);
1888 goto fail_tree_root;
1889 }
1890 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1891 tree_root->commit_root = btrfs_root_node(tree_root);
1892
1893 ret = find_and_setup_root(tree_root, fs_info,
1894 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1895 if (ret)
1896 goto fail_tree_root;
1897 extent_root->track_dirty = 1;
1898
1899 ret = find_and_setup_root(tree_root, fs_info,
1900 BTRFS_DEV_TREE_OBJECTID, dev_root);
1901 if (ret)
1902 goto fail_extent_root;
1903 dev_root->track_dirty = 1;
1904
1905 ret = find_and_setup_root(tree_root, fs_info,
1906 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1907 if (ret)
1908 goto fail_dev_root;
1909
1910 csum_root->track_dirty = 1;
1911
1912 fs_info->generation = generation;
1913 fs_info->last_trans_committed = generation;
1914 fs_info->data_alloc_profile = (u64)-1;
1915 fs_info->metadata_alloc_profile = (u64)-1;
1916 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1917
1918 ret = btrfs_read_block_groups(extent_root);
1919 if (ret) {
1920 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1921 goto fail_block_groups;
1922 }
1923
1924 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1925 "btrfs-cleaner");
1926 if (IS_ERR(fs_info->cleaner_kthread))
1927 goto fail_block_groups;
1928
1929 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1930 tree_root,
1931 "btrfs-transaction");
1932 if (IS_ERR(fs_info->transaction_kthread))
1933 goto fail_cleaner;
1934
1935 if (!btrfs_test_opt(tree_root, SSD) &&
1936 !btrfs_test_opt(tree_root, NOSSD) &&
1937 !fs_info->fs_devices->rotating) {
1938 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1939 "mode\n");
1940 btrfs_set_opt(fs_info->mount_opt, SSD);
1941 }
1942
1943 if (btrfs_super_log_root(disk_super) != 0) {
1944 u64 bytenr = btrfs_super_log_root(disk_super);
1945
1946 if (fs_devices->rw_devices == 0) {
1947 printk(KERN_WARNING "Btrfs log replay required "
1948 "on RO media\n");
1949 err = -EIO;
1950 goto fail_trans_kthread;
1951 }
1952 blocksize =
1953 btrfs_level_size(tree_root,
1954 btrfs_super_log_root_level(disk_super));
1955
1956 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1957 if (!log_tree_root) {
1958 err = -ENOMEM;
1959 goto fail_trans_kthread;
1960 }
1961
1962 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1963 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1964
1965 log_tree_root->node = read_tree_block(tree_root, bytenr,
1966 blocksize,
1967 generation + 1);
1968 ret = btrfs_recover_log_trees(log_tree_root);
1969 BUG_ON(ret);
1970
1971 if (sb->s_flags & MS_RDONLY) {
1972 ret = btrfs_commit_super(tree_root);
1973 BUG_ON(ret);
1974 }
1975 }
1976
1977 ret = btrfs_find_orphan_roots(tree_root);
1978 BUG_ON(ret);
1979
1980 if (!(sb->s_flags & MS_RDONLY)) {
1981 ret = btrfs_cleanup_fs_roots(fs_info);
1982 BUG_ON(ret);
1983
1984 ret = btrfs_recover_relocation(tree_root);
1985 if (ret < 0) {
1986 printk(KERN_WARNING
1987 "btrfs: failed to recover relocation\n");
1988 err = -EINVAL;
1989 goto fail_trans_kthread;
1990 }
1991 }
1992
1993 location.objectid = BTRFS_FS_TREE_OBJECTID;
1994 location.type = BTRFS_ROOT_ITEM_KEY;
1995 location.offset = (u64)-1;
1996
1997 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1998 if (!fs_info->fs_root)
1999 goto fail_trans_kthread;
2000 if (IS_ERR(fs_info->fs_root)) {
2001 err = PTR_ERR(fs_info->fs_root);
2002 goto fail_trans_kthread;
2003 }
2004
2005 if (!(sb->s_flags & MS_RDONLY)) {
2006 down_read(&fs_info->cleanup_work_sem);
2007 btrfs_orphan_cleanup(fs_info->fs_root);
2008 btrfs_orphan_cleanup(fs_info->tree_root);
2009 up_read(&fs_info->cleanup_work_sem);
2010 }
2011
2012 return tree_root;
2013
2014 fail_trans_kthread:
2015 kthread_stop(fs_info->transaction_kthread);
2016 fail_cleaner:
2017 kthread_stop(fs_info->cleaner_kthread);
2018
2019 /*
2020 * make sure we're done with the btree inode before we stop our
2021 * kthreads
2022 */
2023 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2024 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2025
2026 fail_block_groups:
2027 btrfs_free_block_groups(fs_info);
2028 free_extent_buffer(csum_root->node);
2029 free_extent_buffer(csum_root->commit_root);
2030 fail_dev_root:
2031 free_extent_buffer(dev_root->node);
2032 free_extent_buffer(dev_root->commit_root);
2033 fail_extent_root:
2034 free_extent_buffer(extent_root->node);
2035 free_extent_buffer(extent_root->commit_root);
2036 fail_tree_root:
2037 free_extent_buffer(tree_root->node);
2038 free_extent_buffer(tree_root->commit_root);
2039 fail_chunk_root:
2040 free_extent_buffer(chunk_root->node);
2041 free_extent_buffer(chunk_root->commit_root);
2042 fail_sb_buffer:
2043 btrfs_stop_workers(&fs_info->generic_worker);
2044 btrfs_stop_workers(&fs_info->fixup_workers);
2045 btrfs_stop_workers(&fs_info->delalloc_workers);
2046 btrfs_stop_workers(&fs_info->workers);
2047 btrfs_stop_workers(&fs_info->endio_workers);
2048 btrfs_stop_workers(&fs_info->endio_meta_workers);
2049 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2050 btrfs_stop_workers(&fs_info->endio_write_workers);
2051 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2052 btrfs_stop_workers(&fs_info->submit_workers);
2053 fail_iput:
2054 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2055 iput(fs_info->btree_inode);
2056
2057 btrfs_close_devices(fs_info->fs_devices);
2058 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2059 fail_bdi:
2060 bdi_destroy(&fs_info->bdi);
2061 fail_srcu:
2062 cleanup_srcu_struct(&fs_info->subvol_srcu);
2063 fail:
2064 kfree(extent_root);
2065 kfree(tree_root);
2066 kfree(fs_info);
2067 kfree(chunk_root);
2068 kfree(dev_root);
2069 kfree(csum_root);
2070 return ERR_PTR(err);
2071 }
2072
2073 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2074 {
2075 char b[BDEVNAME_SIZE];
2076
2077 if (uptodate) {
2078 set_buffer_uptodate(bh);
2079 } else {
2080 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
2081 printk(KERN_WARNING "lost page write due to "
2082 "I/O error on %s\n",
2083 bdevname(bh->b_bdev, b));
2084 }
2085 /* note, we dont' set_buffer_write_io_error because we have
2086 * our own ways of dealing with the IO errors
2087 */
2088 clear_buffer_uptodate(bh);
2089 }
2090 unlock_buffer(bh);
2091 put_bh(bh);
2092 }
2093
2094 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2095 {
2096 struct buffer_head *bh;
2097 struct buffer_head *latest = NULL;
2098 struct btrfs_super_block *super;
2099 int i;
2100 u64 transid = 0;
2101 u64 bytenr;
2102
2103 /* we would like to check all the supers, but that would make
2104 * a btrfs mount succeed after a mkfs from a different FS.
2105 * So, we need to add a special mount option to scan for
2106 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2107 */
2108 for (i = 0; i < 1; i++) {
2109 bytenr = btrfs_sb_offset(i);
2110 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2111 break;
2112 bh = __bread(bdev, bytenr / 4096, 4096);
2113 if (!bh)
2114 continue;
2115
2116 super = (struct btrfs_super_block *)bh->b_data;
2117 if (btrfs_super_bytenr(super) != bytenr ||
2118 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2119 sizeof(super->magic))) {
2120 brelse(bh);
2121 continue;
2122 }
2123
2124 if (!latest || btrfs_super_generation(super) > transid) {
2125 brelse(latest);
2126 latest = bh;
2127 transid = btrfs_super_generation(super);
2128 } else {
2129 brelse(bh);
2130 }
2131 }
2132 return latest;
2133 }
2134
2135 /*
2136 * this should be called twice, once with wait == 0 and
2137 * once with wait == 1. When wait == 0 is done, all the buffer heads
2138 * we write are pinned.
2139 *
2140 * They are released when wait == 1 is done.
2141 * max_mirrors must be the same for both runs, and it indicates how
2142 * many supers on this one device should be written.
2143 *
2144 * max_mirrors == 0 means to write them all.
2145 */
2146 static int write_dev_supers(struct btrfs_device *device,
2147 struct btrfs_super_block *sb,
2148 int do_barriers, int wait, int max_mirrors)
2149 {
2150 struct buffer_head *bh;
2151 int i;
2152 int ret;
2153 int errors = 0;
2154 u32 crc;
2155 u64 bytenr;
2156 int last_barrier = 0;
2157
2158 if (max_mirrors == 0)
2159 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2160
2161 /* make sure only the last submit_bh does a barrier */
2162 if (do_barriers) {
2163 for (i = 0; i < max_mirrors; i++) {
2164 bytenr = btrfs_sb_offset(i);
2165 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2166 device->total_bytes)
2167 break;
2168 last_barrier = i;
2169 }
2170 }
2171
2172 for (i = 0; i < max_mirrors; i++) {
2173 bytenr = btrfs_sb_offset(i);
2174 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2175 break;
2176
2177 if (wait) {
2178 bh = __find_get_block(device->bdev, bytenr / 4096,
2179 BTRFS_SUPER_INFO_SIZE);
2180 BUG_ON(!bh);
2181 wait_on_buffer(bh);
2182 if (!buffer_uptodate(bh))
2183 errors++;
2184
2185 /* drop our reference */
2186 brelse(bh);
2187
2188 /* drop the reference from the wait == 0 run */
2189 brelse(bh);
2190 continue;
2191 } else {
2192 btrfs_set_super_bytenr(sb, bytenr);
2193
2194 crc = ~(u32)0;
2195 crc = btrfs_csum_data(NULL, (char *)sb +
2196 BTRFS_CSUM_SIZE, crc,
2197 BTRFS_SUPER_INFO_SIZE -
2198 BTRFS_CSUM_SIZE);
2199 btrfs_csum_final(crc, sb->csum);
2200
2201 /*
2202 * one reference for us, and we leave it for the
2203 * caller
2204 */
2205 bh = __getblk(device->bdev, bytenr / 4096,
2206 BTRFS_SUPER_INFO_SIZE);
2207 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2208
2209 /* one reference for submit_bh */
2210 get_bh(bh);
2211
2212 set_buffer_uptodate(bh);
2213 lock_buffer(bh);
2214 bh->b_end_io = btrfs_end_buffer_write_sync;
2215 }
2216
2217 if (i == last_barrier && do_barriers && device->barriers) {
2218 ret = submit_bh(WRITE_BARRIER, bh);
2219 if (ret == -EOPNOTSUPP) {
2220 printk("btrfs: disabling barriers on dev %s\n",
2221 device->name);
2222 set_buffer_uptodate(bh);
2223 device->barriers = 0;
2224 /* one reference for submit_bh */
2225 get_bh(bh);
2226 lock_buffer(bh);
2227 ret = submit_bh(WRITE_SYNC, bh);
2228 }
2229 } else {
2230 ret = submit_bh(WRITE_SYNC, bh);
2231 }
2232
2233 if (ret)
2234 errors++;
2235 }
2236 return errors < i ? 0 : -1;
2237 }
2238
2239 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2240 {
2241 struct list_head *head;
2242 struct btrfs_device *dev;
2243 struct btrfs_super_block *sb;
2244 struct btrfs_dev_item *dev_item;
2245 int ret;
2246 int do_barriers;
2247 int max_errors;
2248 int total_errors = 0;
2249 u64 flags;
2250
2251 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2252 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2253
2254 sb = &root->fs_info->super_for_commit;
2255 dev_item = &sb->dev_item;
2256
2257 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2258 head = &root->fs_info->fs_devices->devices;
2259 list_for_each_entry(dev, head, dev_list) {
2260 if (!dev->bdev) {
2261 total_errors++;
2262 continue;
2263 }
2264 if (!dev->in_fs_metadata || !dev->writeable)
2265 continue;
2266
2267 btrfs_set_stack_device_generation(dev_item, 0);
2268 btrfs_set_stack_device_type(dev_item, dev->type);
2269 btrfs_set_stack_device_id(dev_item, dev->devid);
2270 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2271 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2272 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2273 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2274 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2275 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2276 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2277
2278 flags = btrfs_super_flags(sb);
2279 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2280
2281 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2282 if (ret)
2283 total_errors++;
2284 }
2285 if (total_errors > max_errors) {
2286 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2287 total_errors);
2288 BUG();
2289 }
2290
2291 total_errors = 0;
2292 list_for_each_entry(dev, head, dev_list) {
2293 if (!dev->bdev)
2294 continue;
2295 if (!dev->in_fs_metadata || !dev->writeable)
2296 continue;
2297
2298 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2299 if (ret)
2300 total_errors++;
2301 }
2302 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2303 if (total_errors > max_errors) {
2304 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2305 total_errors);
2306 BUG();
2307 }
2308 return 0;
2309 }
2310
2311 int write_ctree_super(struct btrfs_trans_handle *trans,
2312 struct btrfs_root *root, int max_mirrors)
2313 {
2314 int ret;
2315
2316 ret = write_all_supers(root, max_mirrors);
2317 return ret;
2318 }
2319
2320 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2321 {
2322 spin_lock(&fs_info->fs_roots_radix_lock);
2323 radix_tree_delete(&fs_info->fs_roots_radix,
2324 (unsigned long)root->root_key.objectid);
2325 spin_unlock(&fs_info->fs_roots_radix_lock);
2326
2327 if (btrfs_root_refs(&root->root_item) == 0)
2328 synchronize_srcu(&fs_info->subvol_srcu);
2329
2330 free_fs_root(root);
2331 return 0;
2332 }
2333
2334 static void free_fs_root(struct btrfs_root *root)
2335 {
2336 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2337 if (root->anon_super.s_dev) {
2338 down_write(&root->anon_super.s_umount);
2339 kill_anon_super(&root->anon_super);
2340 }
2341 free_extent_buffer(root->node);
2342 free_extent_buffer(root->commit_root);
2343 kfree(root->name);
2344 kfree(root);
2345 }
2346
2347 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2348 {
2349 int ret;
2350 struct btrfs_root *gang[8];
2351 int i;
2352
2353 while (!list_empty(&fs_info->dead_roots)) {
2354 gang[0] = list_entry(fs_info->dead_roots.next,
2355 struct btrfs_root, root_list);
2356 list_del(&gang[0]->root_list);
2357
2358 if (gang[0]->in_radix) {
2359 btrfs_free_fs_root(fs_info, gang[0]);
2360 } else {
2361 free_extent_buffer(gang[0]->node);
2362 free_extent_buffer(gang[0]->commit_root);
2363 kfree(gang[0]);
2364 }
2365 }
2366
2367 while (1) {
2368 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2369 (void **)gang, 0,
2370 ARRAY_SIZE(gang));
2371 if (!ret)
2372 break;
2373 for (i = 0; i < ret; i++)
2374 btrfs_free_fs_root(fs_info, gang[i]);
2375 }
2376 return 0;
2377 }
2378
2379 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2380 {
2381 u64 root_objectid = 0;
2382 struct btrfs_root *gang[8];
2383 int i;
2384 int ret;
2385
2386 while (1) {
2387 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2388 (void **)gang, root_objectid,
2389 ARRAY_SIZE(gang));
2390 if (!ret)
2391 break;
2392
2393 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2394 for (i = 0; i < ret; i++) {
2395 root_objectid = gang[i]->root_key.objectid;
2396 btrfs_orphan_cleanup(gang[i]);
2397 }
2398 root_objectid++;
2399 }
2400 return 0;
2401 }
2402
2403 int btrfs_commit_super(struct btrfs_root *root)
2404 {
2405 struct btrfs_trans_handle *trans;
2406 int ret;
2407
2408 mutex_lock(&root->fs_info->cleaner_mutex);
2409 btrfs_run_delayed_iputs(root);
2410 btrfs_clean_old_snapshots(root);
2411 mutex_unlock(&root->fs_info->cleaner_mutex);
2412
2413 /* wait until ongoing cleanup work done */
2414 down_write(&root->fs_info->cleanup_work_sem);
2415 up_write(&root->fs_info->cleanup_work_sem);
2416
2417 trans = btrfs_join_transaction(root, 1);
2418 ret = btrfs_commit_transaction(trans, root);
2419 BUG_ON(ret);
2420 /* run commit again to drop the original snapshot */
2421 trans = btrfs_join_transaction(root, 1);
2422 btrfs_commit_transaction(trans, root);
2423 ret = btrfs_write_and_wait_transaction(NULL, root);
2424 BUG_ON(ret);
2425
2426 ret = write_ctree_super(NULL, root, 0);
2427 return ret;
2428 }
2429
2430 int close_ctree(struct btrfs_root *root)
2431 {
2432 struct btrfs_fs_info *fs_info = root->fs_info;
2433 int ret;
2434
2435 fs_info->closing = 1;
2436 smp_mb();
2437
2438 btrfs_put_block_group_cache(fs_info);
2439 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2440 ret = btrfs_commit_super(root);
2441 if (ret)
2442 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2443 }
2444
2445 kthread_stop(root->fs_info->transaction_kthread);
2446 kthread_stop(root->fs_info->cleaner_kthread);
2447
2448 fs_info->closing = 2;
2449 smp_mb();
2450
2451 if (fs_info->delalloc_bytes) {
2452 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2453 (unsigned long long)fs_info->delalloc_bytes);
2454 }
2455 if (fs_info->total_ref_cache_size) {
2456 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2457 (unsigned long long)fs_info->total_ref_cache_size);
2458 }
2459
2460 free_extent_buffer(fs_info->extent_root->node);
2461 free_extent_buffer(fs_info->extent_root->commit_root);
2462 free_extent_buffer(fs_info->tree_root->node);
2463 free_extent_buffer(fs_info->tree_root->commit_root);
2464 free_extent_buffer(root->fs_info->chunk_root->node);
2465 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2466 free_extent_buffer(root->fs_info->dev_root->node);
2467 free_extent_buffer(root->fs_info->dev_root->commit_root);
2468 free_extent_buffer(root->fs_info->csum_root->node);
2469 free_extent_buffer(root->fs_info->csum_root->commit_root);
2470
2471 btrfs_free_block_groups(root->fs_info);
2472
2473 del_fs_roots(fs_info);
2474
2475 iput(fs_info->btree_inode);
2476
2477 btrfs_stop_workers(&fs_info->generic_worker);
2478 btrfs_stop_workers(&fs_info->fixup_workers);
2479 btrfs_stop_workers(&fs_info->delalloc_workers);
2480 btrfs_stop_workers(&fs_info->workers);
2481 btrfs_stop_workers(&fs_info->endio_workers);
2482 btrfs_stop_workers(&fs_info->endio_meta_workers);
2483 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2484 btrfs_stop_workers(&fs_info->endio_write_workers);
2485 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2486 btrfs_stop_workers(&fs_info->submit_workers);
2487
2488 btrfs_close_devices(fs_info->fs_devices);
2489 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2490
2491 bdi_destroy(&fs_info->bdi);
2492 cleanup_srcu_struct(&fs_info->subvol_srcu);
2493
2494 kfree(fs_info->extent_root);
2495 kfree(fs_info->tree_root);
2496 kfree(fs_info->chunk_root);
2497 kfree(fs_info->dev_root);
2498 kfree(fs_info->csum_root);
2499 return 0;
2500 }
2501
2502 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2503 {
2504 int ret;
2505 struct inode *btree_inode = buf->first_page->mapping->host;
2506
2507 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2508 NULL);
2509 if (!ret)
2510 return ret;
2511
2512 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2513 parent_transid);
2514 return !ret;
2515 }
2516
2517 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2518 {
2519 struct inode *btree_inode = buf->first_page->mapping->host;
2520 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2521 buf);
2522 }
2523
2524 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2525 {
2526 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2527 u64 transid = btrfs_header_generation(buf);
2528 struct inode *btree_inode = root->fs_info->btree_inode;
2529 int was_dirty;
2530
2531 btrfs_assert_tree_locked(buf);
2532 if (transid != root->fs_info->generation) {
2533 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2534 "found %llu running %llu\n",
2535 (unsigned long long)buf->start,
2536 (unsigned long long)transid,
2537 (unsigned long long)root->fs_info->generation);
2538 WARN_ON(1);
2539 }
2540 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2541 buf);
2542 if (!was_dirty) {
2543 spin_lock(&root->fs_info->delalloc_lock);
2544 root->fs_info->dirty_metadata_bytes += buf->len;
2545 spin_unlock(&root->fs_info->delalloc_lock);
2546 }
2547 }
2548
2549 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2550 {
2551 /*
2552 * looks as though older kernels can get into trouble with
2553 * this code, they end up stuck in balance_dirty_pages forever
2554 */
2555 u64 num_dirty;
2556 unsigned long thresh = 32 * 1024 * 1024;
2557
2558 if (current->flags & PF_MEMALLOC)
2559 return;
2560
2561 num_dirty = root->fs_info->dirty_metadata_bytes;
2562
2563 if (num_dirty > thresh) {
2564 balance_dirty_pages_ratelimited_nr(
2565 root->fs_info->btree_inode->i_mapping, 1);
2566 }
2567 return;
2568 }
2569
2570 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2571 {
2572 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2573 int ret;
2574 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2575 if (ret == 0)
2576 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2577 return ret;
2578 }
2579
2580 int btree_lock_page_hook(struct page *page)
2581 {
2582 struct inode *inode = page->mapping->host;
2583 struct btrfs_root *root = BTRFS_I(inode)->root;
2584 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2585 struct extent_buffer *eb;
2586 unsigned long len;
2587 u64 bytenr = page_offset(page);
2588
2589 if (page->private == EXTENT_PAGE_PRIVATE)
2590 goto out;
2591
2592 len = page->private >> 2;
2593 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2594 if (!eb)
2595 goto out;
2596
2597 btrfs_tree_lock(eb);
2598 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2599
2600 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2601 spin_lock(&root->fs_info->delalloc_lock);
2602 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2603 root->fs_info->dirty_metadata_bytes -= eb->len;
2604 else
2605 WARN_ON(1);
2606 spin_unlock(&root->fs_info->delalloc_lock);
2607 }
2608
2609 btrfs_tree_unlock(eb);
2610 free_extent_buffer(eb);
2611 out:
2612 lock_page(page);
2613 return 0;
2614 }
2615
2616 static struct extent_io_ops btree_extent_io_ops = {
2617 .write_cache_pages_lock_hook = btree_lock_page_hook,
2618 .readpage_end_io_hook = btree_readpage_end_io_hook,
2619 .submit_bio_hook = btree_submit_bio_hook,
2620 /* note we're sharing with inode.c for the merge bio hook */
2621 .merge_bio_hook = btrfs_merge_bio_hook,
2622 };
Linux kernel - Deliverables
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