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Btrfs: reduce mount -o ssd CPU usage
[linux-2.6-block.git] / fs / btrfs / disk-io.c
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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 "compat.h"
30#include "crc32c.h"
31#include "ctree.h"
32#include "disk-io.h"
33#include "transaction.h"
34#include "btrfs_inode.h"
35#include "volumes.h"
36#include "print-tree.h"
37#include "async-thread.h"
38#include "locking.h"
39#include "tree-log.h"
40#include "free-space-cache.h"
41
42static struct extent_io_ops btree_extent_io_ops;
43static void end_workqueue_fn(struct btrfs_work *work);
44
45/*
46 * end_io_wq structs are used to do processing in task context when an IO is
47 * complete. This is used during reads to verify checksums, and it is used
48 * by writes to insert metadata for new file extents after IO is complete.
49 */
50struct end_io_wq {
51 struct bio *bio;
52 bio_end_io_t *end_io;
53 void *private;
54 struct btrfs_fs_info *info;
55 int error;
56 int metadata;
57 struct list_head list;
58 struct btrfs_work work;
59};
60
61/*
62 * async submit bios are used to offload expensive checksumming
63 * onto the worker threads. They checksum file and metadata bios
64 * just before they are sent down the IO stack.
65 */
66struct async_submit_bio {
67 struct inode *inode;
68 struct bio *bio;
69 struct list_head list;
70 extent_submit_bio_hook_t *submit_bio_start;
71 extent_submit_bio_hook_t *submit_bio_done;
72 int rw;
73 int mirror_num;
74 unsigned long bio_flags;
75 struct btrfs_work work;
76};
77
78/* These are used to set the lockdep class on the extent buffer locks.
79 * The class is set by the readpage_end_io_hook after the buffer has
80 * passed csum validation but before the pages are unlocked.
81 *
82 * The lockdep class is also set by btrfs_init_new_buffer on freshly
83 * allocated blocks.
84 *
85 * The class is based on the level in the tree block, which allows lockdep
86 * to know that lower nodes nest inside the locks of higher nodes.
87 *
88 * We also add a check to make sure the highest level of the tree is
89 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
90 * code needs update as well.
91 */
92#ifdef CONFIG_DEBUG_LOCK_ALLOC
93# if BTRFS_MAX_LEVEL != 8
94# error
95# endif
96static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
97static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
98 /* leaf */
99 "btrfs-extent-00",
100 "btrfs-extent-01",
101 "btrfs-extent-02",
102 "btrfs-extent-03",
103 "btrfs-extent-04",
104 "btrfs-extent-05",
105 "btrfs-extent-06",
106 "btrfs-extent-07",
107 /* highest possible level */
108 "btrfs-extent-08",
109};
110#endif
111
112/*
113 * extents on the btree inode are pretty simple, there's one extent
114 * that covers the entire device
115 */
116static struct extent_map *btree_get_extent(struct inode *inode,
117 struct page *page, size_t page_offset, u64 start, u64 len,
118 int create)
119{
120 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
121 struct extent_map *em;
122 int ret;
123
124 spin_lock(&em_tree->lock);
125 em = lookup_extent_mapping(em_tree, start, len);
126 if (em) {
127 em->bdev =
128 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
129 spin_unlock(&em_tree->lock);
130 goto out;
131 }
132 spin_unlock(&em_tree->lock);
133
134 em = alloc_extent_map(GFP_NOFS);
135 if (!em) {
136 em = ERR_PTR(-ENOMEM);
137 goto out;
138 }
139 em->start = 0;
140 em->len = (u64)-1;
141 em->block_len = (u64)-1;
142 em->block_start = 0;
143 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
144
145 spin_lock(&em_tree->lock);
146 ret = add_extent_mapping(em_tree, em);
147 if (ret == -EEXIST) {
148 u64 failed_start = em->start;
149 u64 failed_len = em->len;
150
151 free_extent_map(em);
152 em = lookup_extent_mapping(em_tree, start, len);
153 if (em) {
154 ret = 0;
155 } else {
156 em = lookup_extent_mapping(em_tree, failed_start,
157 failed_len);
158 ret = -EIO;
159 }
160 } else if (ret) {
161 free_extent_map(em);
162 em = NULL;
163 }
164 spin_unlock(&em_tree->lock);
165
166 if (ret)
167 em = ERR_PTR(ret);
168out:
169 return em;
170}
171
172u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
173{
174 return btrfs_crc32c(seed, data, len);
175}
176
177void btrfs_csum_final(u32 crc, char *result)
178{
179 *(__le32 *)result = ~cpu_to_le32(crc);
180}
181
182/*
183 * compute the csum for a btree block, and either verify it or write it
184 * into the csum field of the block.
185 */
186static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
187 int verify)
188{
189 u16 csum_size =
190 btrfs_super_csum_size(&root->fs_info->super_copy);
191 char *result = NULL;
192 unsigned long len;
193 unsigned long cur_len;
194 unsigned long offset = BTRFS_CSUM_SIZE;
195 char *map_token = NULL;
196 char *kaddr;
197 unsigned long map_start;
198 unsigned long map_len;
199 int err;
200 u32 crc = ~(u32)0;
201 unsigned long inline_result;
202
203 len = buf->len - offset;
204 while (len > 0) {
205 err = map_private_extent_buffer(buf, offset, 32,
206 &map_token, &kaddr,
207 &map_start, &map_len, KM_USER0);
208 if (err)
209 return 1;
210 cur_len = min(len, map_len - (offset - map_start));
211 crc = btrfs_csum_data(root, kaddr + offset - map_start,
212 crc, cur_len);
213 len -= cur_len;
214 offset += cur_len;
215 unmap_extent_buffer(buf, map_token, KM_USER0);
216 }
217 if (csum_size > sizeof(inline_result)) {
218 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
219 if (!result)
220 return 1;
221 } else {
222 result = (char *)&inline_result;
223 }
224
225 btrfs_csum_final(crc, result);
226
227 if (verify) {
228 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
229 u32 val;
230 u32 found = 0;
231 memcpy(&found, result, csum_size);
232
233 read_extent_buffer(buf, &val, 0, csum_size);
234 if (printk_ratelimit()) {
235 printk(KERN_INFO "btrfs: %s checksum verify "
236 "failed on %llu wanted %X found %X "
237 "level %d\n",
238 root->fs_info->sb->s_id,
239 (unsigned long long)buf->start, val, found,
240 btrfs_header_level(buf));
241 }
242 if (result != (char *)&inline_result)
243 kfree(result);
244 return 1;
245 }
246 } else {
247 write_extent_buffer(buf, result, 0, csum_size);
248 }
249 if (result != (char *)&inline_result)
250 kfree(result);
251 return 0;
252}
253
254/*
255 * we can't consider a given block up to date unless the transid of the
256 * block matches the transid in the parent node's pointer. This is how we
257 * detect blocks that either didn't get written at all or got written
258 * in the wrong place.
259 */
260static int verify_parent_transid(struct extent_io_tree *io_tree,
261 struct extent_buffer *eb, u64 parent_transid)
262{
263 int ret;
264
265 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
266 return 0;
267
268 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
269 if (extent_buffer_uptodate(io_tree, eb) &&
270 btrfs_header_generation(eb) == parent_transid) {
271 ret = 0;
272 goto out;
273 }
274 if (printk_ratelimit()) {
275 printk("parent transid verify failed on %llu wanted %llu "
276 "found %llu\n",
277 (unsigned long long)eb->start,
278 (unsigned long long)parent_transid,
279 (unsigned long long)btrfs_header_generation(eb));
280 }
281 ret = 1;
282 clear_extent_buffer_uptodate(io_tree, eb);
283out:
284 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
285 GFP_NOFS);
286 return ret;
287}
288
289/*
290 * helper to read a given tree block, doing retries as required when
291 * the checksums don't match and we have alternate mirrors to try.
292 */
293static int btree_read_extent_buffer_pages(struct btrfs_root *root,
294 struct extent_buffer *eb,
295 u64 start, u64 parent_transid)
296{
297 struct extent_io_tree *io_tree;
298 int ret;
299 int num_copies = 0;
300 int mirror_num = 0;
301
302 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
303 while (1) {
304 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
305 btree_get_extent, mirror_num);
306 if (!ret &&
307 !verify_parent_transid(io_tree, eb, parent_transid))
308 return ret;
309
310 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
311 eb->start, eb->len);
312 if (num_copies == 1)
313 return ret;
314
315 mirror_num++;
316 if (mirror_num > num_copies)
317 return ret;
318 }
319 return -EIO;
320}
321
322/*
323 * checksum a dirty tree block before IO. This has extra checks to make sure
324 * we only fill in the checksum field in the first page of a multi-page block
325 */
326
327static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
328{
329 struct extent_io_tree *tree;
330 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
331 u64 found_start;
332 int found_level;
333 unsigned long len;
334 struct extent_buffer *eb;
335 int ret;
336
337 tree = &BTRFS_I(page->mapping->host)->io_tree;
338
339 if (page->private == EXTENT_PAGE_PRIVATE)
340 goto out;
341 if (!page->private)
342 goto out;
343 len = page->private >> 2;
344 WARN_ON(len == 0);
345
346 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
347 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
348 btrfs_header_generation(eb));
349 BUG_ON(ret);
350 found_start = btrfs_header_bytenr(eb);
351 if (found_start != start) {
352 WARN_ON(1);
353 goto err;
354 }
355 if (eb->first_page != page) {
356 WARN_ON(1);
357 goto err;
358 }
359 if (!PageUptodate(page)) {
360 WARN_ON(1);
361 goto err;
362 }
363 found_level = btrfs_header_level(eb);
364
365 csum_tree_block(root, eb, 0);
366err:
367 free_extent_buffer(eb);
368out:
369 return 0;
370}
371
372static int check_tree_block_fsid(struct btrfs_root *root,
373 struct extent_buffer *eb)
374{
375 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
376 u8 fsid[BTRFS_UUID_SIZE];
377 int ret = 1;
378
379 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
380 BTRFS_FSID_SIZE);
381 while (fs_devices) {
382 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
383 ret = 0;
384 break;
385 }
386 fs_devices = fs_devices->seed;
387 }
388 return ret;
389}
390
391#ifdef CONFIG_DEBUG_LOCK_ALLOC
392void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
393{
394 lockdep_set_class_and_name(&eb->lock,
395 &btrfs_eb_class[level],
396 btrfs_eb_name[level]);
397}
398#endif
399
400static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
401 struct extent_state *state)
402{
403 struct extent_io_tree *tree;
404 u64 found_start;
405 int found_level;
406 unsigned long len;
407 struct extent_buffer *eb;
408 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
409 int ret = 0;
410
411 tree = &BTRFS_I(page->mapping->host)->io_tree;
412 if (page->private == EXTENT_PAGE_PRIVATE)
413 goto out;
414 if (!page->private)
415 goto out;
416
417 len = page->private >> 2;
418 WARN_ON(len == 0);
419
420 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
421
422 found_start = btrfs_header_bytenr(eb);
423 if (found_start != start) {
424 if (printk_ratelimit()) {
425 printk(KERN_INFO "btrfs bad tree block start "
426 "%llu %llu\n",
427 (unsigned long long)found_start,
428 (unsigned long long)eb->start);
429 }
430 ret = -EIO;
431 goto err;
432 }
433 if (eb->first_page != page) {
434 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
435 eb->first_page->index, page->index);
436 WARN_ON(1);
437 ret = -EIO;
438 goto err;
439 }
440 if (check_tree_block_fsid(root, eb)) {
441 if (printk_ratelimit()) {
442 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
443 (unsigned long long)eb->start);
444 }
445 ret = -EIO;
446 goto err;
447 }
448 found_level = btrfs_header_level(eb);
449
450 btrfs_set_buffer_lockdep_class(eb, found_level);
451
452 ret = csum_tree_block(root, eb, 1);
453 if (ret)
454 ret = -EIO;
455
456 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
457 end = eb->start + end - 1;
458err:
459 free_extent_buffer(eb);
460out:
461 return ret;
462}
463
464static void end_workqueue_bio(struct bio *bio, int err)
465{
466 struct end_io_wq *end_io_wq = bio->bi_private;
467 struct btrfs_fs_info *fs_info;
468
469 fs_info = end_io_wq->info;
470 end_io_wq->error = err;
471 end_io_wq->work.func = end_workqueue_fn;
472 end_io_wq->work.flags = 0;
473
474 if (bio->bi_rw & (1 << BIO_RW)) {
475 if (end_io_wq->metadata)
476 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
477 &end_io_wq->work);
478 else
479 btrfs_queue_worker(&fs_info->endio_write_workers,
480 &end_io_wq->work);
481 } else {
482 if (end_io_wq->metadata)
483 btrfs_queue_worker(&fs_info->endio_meta_workers,
484 &end_io_wq->work);
485 else
486 btrfs_queue_worker(&fs_info->endio_workers,
487 &end_io_wq->work);
488 }
489}
490
491int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
492 int metadata)
493{
494 struct end_io_wq *end_io_wq;
495 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
496 if (!end_io_wq)
497 return -ENOMEM;
498
499 end_io_wq->private = bio->bi_private;
500 end_io_wq->end_io = bio->bi_end_io;
501 end_io_wq->info = info;
502 end_io_wq->error = 0;
503 end_io_wq->bio = bio;
504 end_io_wq->metadata = metadata;
505
506 bio->bi_private = end_io_wq;
507 bio->bi_end_io = end_workqueue_bio;
508 return 0;
509}
510
511unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
512{
513 unsigned long limit = min_t(unsigned long,
514 info->workers.max_workers,
515 info->fs_devices->open_devices);
516 return 256 * limit;
517}
518
519int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
520{
521 return atomic_read(&info->nr_async_bios) >
522 btrfs_async_submit_limit(info);
523}
524
525static void run_one_async_start(struct btrfs_work *work)
526{
527 struct btrfs_fs_info *fs_info;
528 struct async_submit_bio *async;
529
530 async = container_of(work, struct async_submit_bio, work);
531 fs_info = BTRFS_I(async->inode)->root->fs_info;
532 async->submit_bio_start(async->inode, async->rw, async->bio,
533 async->mirror_num, async->bio_flags);
534}
535
536static void run_one_async_done(struct btrfs_work *work)
537{
538 struct btrfs_fs_info *fs_info;
539 struct async_submit_bio *async;
540 int limit;
541
542 async = container_of(work, struct async_submit_bio, work);
543 fs_info = BTRFS_I(async->inode)->root->fs_info;
544
545 limit = btrfs_async_submit_limit(fs_info);
546 limit = limit * 2 / 3;
547
548 atomic_dec(&fs_info->nr_async_submits);
549
550 if (atomic_read(&fs_info->nr_async_submits) < limit &&
551 waitqueue_active(&fs_info->async_submit_wait))
552 wake_up(&fs_info->async_submit_wait);
553
554 async->submit_bio_done(async->inode, async->rw, async->bio,
555 async->mirror_num, async->bio_flags);
556}
557
558static void run_one_async_free(struct btrfs_work *work)
559{
560 struct async_submit_bio *async;
561
562 async = container_of(work, struct async_submit_bio, work);
563 kfree(async);
564}
565
566int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
567 int rw, struct bio *bio, int mirror_num,
568 unsigned long bio_flags,
569 extent_submit_bio_hook_t *submit_bio_start,
570 extent_submit_bio_hook_t *submit_bio_done)
571{
572 struct async_submit_bio *async;
573
574 async = kmalloc(sizeof(*async), GFP_NOFS);
575 if (!async)
576 return -ENOMEM;
577
578 async->inode = inode;
579 async->rw = rw;
580 async->bio = bio;
581 async->mirror_num = mirror_num;
582 async->submit_bio_start = submit_bio_start;
583 async->submit_bio_done = submit_bio_done;
584
585 async->work.func = run_one_async_start;
586 async->work.ordered_func = run_one_async_done;
587 async->work.ordered_free = run_one_async_free;
588
589 async->work.flags = 0;
590 async->bio_flags = bio_flags;
591
592 atomic_inc(&fs_info->nr_async_submits);
593
594 if (rw & (1 << BIO_RW_SYNCIO))
595 btrfs_set_work_high_prio(&async->work);
596
597 btrfs_queue_worker(&fs_info->workers, &async->work);
598
599 while (atomic_read(&fs_info->async_submit_draining) &&
600 atomic_read(&fs_info->nr_async_submits)) {
601 wait_event(fs_info->async_submit_wait,
602 (atomic_read(&fs_info->nr_async_submits) == 0));
603 }
604
605 return 0;
606}
607
608static int btree_csum_one_bio(struct bio *bio)
609{
610 struct bio_vec *bvec = bio->bi_io_vec;
611 int bio_index = 0;
612 struct btrfs_root *root;
613
614 WARN_ON(bio->bi_vcnt <= 0);
615 while (bio_index < bio->bi_vcnt) {
616 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
617 csum_dirty_buffer(root, bvec->bv_page);
618 bio_index++;
619 bvec++;
620 }
621 return 0;
622}
623
624static int __btree_submit_bio_start(struct inode *inode, int rw,
625 struct bio *bio, int mirror_num,
626 unsigned long bio_flags)
627{
628 /*
629 * when we're called for a write, we're already in the async
630 * submission context. Just jump into btrfs_map_bio
631 */
632 btree_csum_one_bio(bio);
633 return 0;
634}
635
636static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
637 int mirror_num, unsigned long bio_flags)
638{
639 /*
640 * when we're called for a write, we're already in the async
641 * submission context. Just jump into btrfs_map_bio
642 */
643 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
644}
645
646static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
647 int mirror_num, unsigned long bio_flags)
648{
649 int ret;
650
651 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
652 bio, 1);
653 BUG_ON(ret);
654
655 if (!(rw & (1 << BIO_RW))) {
656 /*
657 * called for a read, do the setup so that checksum validation
658 * can happen in the async kernel threads
659 */
660 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
661 mirror_num, 0);
662 }
663
664 /*
665 * kthread helpers are used to submit writes so that checksumming
666 * can happen in parallel across all CPUs
667 */
668 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
669 inode, rw, bio, mirror_num, 0,
670 __btree_submit_bio_start,
671 __btree_submit_bio_done);
672}
673
674static int btree_writepage(struct page *page, struct writeback_control *wbc)
675{
676 struct extent_io_tree *tree;
677 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
678 struct extent_buffer *eb;
679 int was_dirty;
680
681 tree = &BTRFS_I(page->mapping->host)->io_tree;
682 if (!(current->flags & PF_MEMALLOC)) {
683 return extent_write_full_page(tree, page,
684 btree_get_extent, wbc);
685 }
686
687 redirty_page_for_writepage(wbc, page);
688 eb = btrfs_find_tree_block(root, page_offset(page),
689 PAGE_CACHE_SIZE);
690 WARN_ON(!eb);
691
692 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
693 if (!was_dirty) {
694 spin_lock(&root->fs_info->delalloc_lock);
695 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
696 spin_unlock(&root->fs_info->delalloc_lock);
697 }
698 free_extent_buffer(eb);
699
700 unlock_page(page);
701 return 0;
702}
703
704static int btree_writepages(struct address_space *mapping,
705 struct writeback_control *wbc)
706{
707 struct extent_io_tree *tree;
708 tree = &BTRFS_I(mapping->host)->io_tree;
709 if (wbc->sync_mode == WB_SYNC_NONE) {
710 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
711 u64 num_dirty;
712 unsigned long thresh = 32 * 1024 * 1024;
713
714 if (wbc->for_kupdate)
715 return 0;
716
717 /* this is a bit racy, but that's ok */
718 num_dirty = root->fs_info->dirty_metadata_bytes;
719 if (num_dirty < thresh)
720 return 0;
721 }
722 return extent_writepages(tree, mapping, btree_get_extent, wbc);
723}
724
725static int btree_readpage(struct file *file, struct page *page)
726{
727 struct extent_io_tree *tree;
728 tree = &BTRFS_I(page->mapping->host)->io_tree;
729 return extent_read_full_page(tree, page, btree_get_extent);
730}
731
732static int btree_releasepage(struct page *page, gfp_t gfp_flags)
733{
734 struct extent_io_tree *tree;
735 struct extent_map_tree *map;
736 int ret;
737
738 if (PageWriteback(page) || PageDirty(page))
739 return 0;
740
741 tree = &BTRFS_I(page->mapping->host)->io_tree;
742 map = &BTRFS_I(page->mapping->host)->extent_tree;
743
744 ret = try_release_extent_state(map, tree, page, gfp_flags);
745 if (!ret)
746 return 0;
747
748 ret = try_release_extent_buffer(tree, page);
749 if (ret == 1) {
750 ClearPagePrivate(page);
751 set_page_private(page, 0);
752 page_cache_release(page);
753 }
754
755 return ret;
756}
757
758static void btree_invalidatepage(struct page *page, unsigned long offset)
759{
760 struct extent_io_tree *tree;
761 tree = &BTRFS_I(page->mapping->host)->io_tree;
762 extent_invalidatepage(tree, page, offset);
763 btree_releasepage(page, GFP_NOFS);
764 if (PagePrivate(page)) {
765 printk(KERN_WARNING "btrfs warning page private not zero "
766 "on page %llu\n", (unsigned long long)page_offset(page));
767 ClearPagePrivate(page);
768 set_page_private(page, 0);
769 page_cache_release(page);
770 }
771}
772
773static struct address_space_operations btree_aops = {
774 .readpage = btree_readpage,
775 .writepage = btree_writepage,
776 .writepages = btree_writepages,
777 .releasepage = btree_releasepage,
778 .invalidatepage = btree_invalidatepage,
779 .sync_page = block_sync_page,
780};
781
782int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
783 u64 parent_transid)
784{
785 struct extent_buffer *buf = NULL;
786 struct inode *btree_inode = root->fs_info->btree_inode;
787 int ret = 0;
788
789 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
790 if (!buf)
791 return 0;
792 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
793 buf, 0, 0, btree_get_extent, 0);
794 free_extent_buffer(buf);
795 return ret;
796}
797
798struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
799 u64 bytenr, u32 blocksize)
800{
801 struct inode *btree_inode = root->fs_info->btree_inode;
802 struct extent_buffer *eb;
803 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
804 bytenr, blocksize, GFP_NOFS);
805 return eb;
806}
807
808struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
809 u64 bytenr, u32 blocksize)
810{
811 struct inode *btree_inode = root->fs_info->btree_inode;
812 struct extent_buffer *eb;
813
814 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
815 bytenr, blocksize, NULL, GFP_NOFS);
816 return eb;
817}
818
819
820int btrfs_write_tree_block(struct extent_buffer *buf)
821{
822 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
823 buf->start + buf->len - 1, WB_SYNC_ALL);
824}
825
826int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
827{
828 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
829 buf->start, buf->start + buf->len - 1);
830}
831
832struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
833 u32 blocksize, u64 parent_transid)
834{
835 struct extent_buffer *buf = NULL;
836 struct inode *btree_inode = root->fs_info->btree_inode;
837 struct extent_io_tree *io_tree;
838 int ret;
839
840 io_tree = &BTRFS_I(btree_inode)->io_tree;
841
842 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
843 if (!buf)
844 return NULL;
845
846 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
847
848 if (ret == 0)
849 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
850 return buf;
851
852}
853
854int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
855 struct extent_buffer *buf)
856{
857 struct inode *btree_inode = root->fs_info->btree_inode;
858 if (btrfs_header_generation(buf) ==
859 root->fs_info->running_transaction->transid) {
860 btrfs_assert_tree_locked(buf);
861
862 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
863 spin_lock(&root->fs_info->delalloc_lock);
864 if (root->fs_info->dirty_metadata_bytes >= buf->len)
865 root->fs_info->dirty_metadata_bytes -= buf->len;
866 else
867 WARN_ON(1);
868 spin_unlock(&root->fs_info->delalloc_lock);
869 }
870
871 /* ugh, clear_extent_buffer_dirty needs to lock the page */
872 btrfs_set_lock_blocking(buf);
873 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
874 buf);
875 }
876 return 0;
877}
878
879static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
880 u32 stripesize, struct btrfs_root *root,
881 struct btrfs_fs_info *fs_info,
882 u64 objectid)
883{
884 root->node = NULL;
885 root->commit_root = NULL;
886 root->sectorsize = sectorsize;
887 root->nodesize = nodesize;
888 root->leafsize = leafsize;
889 root->stripesize = stripesize;
890 root->ref_cows = 0;
891 root->track_dirty = 0;
892
893 root->fs_info = fs_info;
894 root->objectid = objectid;
895 root->last_trans = 0;
896 root->highest_inode = 0;
897 root->last_inode_alloc = 0;
898 root->name = NULL;
899 root->in_sysfs = 0;
900 root->inode_tree.rb_node = NULL;
901
902 INIT_LIST_HEAD(&root->dirty_list);
903 INIT_LIST_HEAD(&root->orphan_list);
904 INIT_LIST_HEAD(&root->root_list);
905 spin_lock_init(&root->node_lock);
906 spin_lock_init(&root->list_lock);
907 spin_lock_init(&root->inode_lock);
908 mutex_init(&root->objectid_mutex);
909 mutex_init(&root->log_mutex);
910 init_waitqueue_head(&root->log_writer_wait);
911 init_waitqueue_head(&root->log_commit_wait[0]);
912 init_waitqueue_head(&root->log_commit_wait[1]);
913 atomic_set(&root->log_commit[0], 0);
914 atomic_set(&root->log_commit[1], 0);
915 atomic_set(&root->log_writers, 0);
916 root->log_batch = 0;
917 root->log_transid = 0;
918 extent_io_tree_init(&root->dirty_log_pages,
919 fs_info->btree_inode->i_mapping, GFP_NOFS);
920
921 memset(&root->root_key, 0, sizeof(root->root_key));
922 memset(&root->root_item, 0, sizeof(root->root_item));
923 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
924 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
925 root->defrag_trans_start = fs_info->generation;
926 init_completion(&root->kobj_unregister);
927 root->defrag_running = 0;
928 root->defrag_level = 0;
929 root->root_key.objectid = objectid;
930 root->anon_super.s_root = NULL;
931 root->anon_super.s_dev = 0;
932 INIT_LIST_HEAD(&root->anon_super.s_list);
933 INIT_LIST_HEAD(&root->anon_super.s_instances);
934 init_rwsem(&root->anon_super.s_umount);
935
936 return 0;
937}
938
939static int find_and_setup_root(struct btrfs_root *tree_root,
940 struct btrfs_fs_info *fs_info,
941 u64 objectid,
942 struct btrfs_root *root)
943{
944 int ret;
945 u32 blocksize;
946 u64 generation;
947
948 __setup_root(tree_root->nodesize, tree_root->leafsize,
949 tree_root->sectorsize, tree_root->stripesize,
950 root, fs_info, objectid);
951 ret = btrfs_find_last_root(tree_root, objectid,
952 &root->root_item, &root->root_key);
953 BUG_ON(ret);
954
955 generation = btrfs_root_generation(&root->root_item);
956 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
957 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
958 blocksize, generation);
959 root->commit_root = btrfs_root_node(root);
960 BUG_ON(!root->node);
961 return 0;
962}
963
964int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
965 struct btrfs_fs_info *fs_info)
966{
967 struct extent_buffer *eb;
968 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
969 u64 start = 0;
970 u64 end = 0;
971 int ret;
972
973 if (!log_root_tree)
974 return 0;
975
976 while (1) {
977 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
978 0, &start, &end, EXTENT_DIRTY);
979 if (ret)
980 break;
981
982 clear_extent_dirty(&log_root_tree->dirty_log_pages,
983 start, end, GFP_NOFS);
984 }
985 eb = fs_info->log_root_tree->node;
986
987 WARN_ON(btrfs_header_level(eb) != 0);
988 WARN_ON(btrfs_header_nritems(eb) != 0);
989
990 ret = btrfs_free_reserved_extent(fs_info->tree_root,
991 eb->start, eb->len);
992 BUG_ON(ret);
993
994 free_extent_buffer(eb);
995 kfree(fs_info->log_root_tree);
996 fs_info->log_root_tree = NULL;
997 return 0;
998}
999
1000static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1001 struct btrfs_fs_info *fs_info)
1002{
1003 struct btrfs_root *root;
1004 struct btrfs_root *tree_root = fs_info->tree_root;
1005 struct extent_buffer *leaf;
1006
1007 root = kzalloc(sizeof(*root), GFP_NOFS);
1008 if (!root)
1009 return ERR_PTR(-ENOMEM);
1010
1011 __setup_root(tree_root->nodesize, tree_root->leafsize,
1012 tree_root->sectorsize, tree_root->stripesize,
1013 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1014
1015 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1016 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1017 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1018 /*
1019 * log trees do not get reference counted because they go away
1020 * before a real commit is actually done. They do store pointers
1021 * to file data extents, and those reference counts still get
1022 * updated (along with back refs to the log tree).
1023 */
1024 root->ref_cows = 0;
1025
1026 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1027 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1028 if (IS_ERR(leaf)) {
1029 kfree(root);
1030 return ERR_CAST(leaf);
1031 }
1032
1033 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1034 btrfs_set_header_bytenr(leaf, leaf->start);
1035 btrfs_set_header_generation(leaf, trans->transid);
1036 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1037 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1038 root->node = leaf;
1039
1040 write_extent_buffer(root->node, root->fs_info->fsid,
1041 (unsigned long)btrfs_header_fsid(root->node),
1042 BTRFS_FSID_SIZE);
1043 btrfs_mark_buffer_dirty(root->node);
1044 btrfs_tree_unlock(root->node);
1045 return root;
1046}
1047
1048int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1049 struct btrfs_fs_info *fs_info)
1050{
1051 struct btrfs_root *log_root;
1052
1053 log_root = alloc_log_tree(trans, fs_info);
1054 if (IS_ERR(log_root))
1055 return PTR_ERR(log_root);
1056 WARN_ON(fs_info->log_root_tree);
1057 fs_info->log_root_tree = log_root;
1058 return 0;
1059}
1060
1061int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1062 struct btrfs_root *root)
1063{
1064 struct btrfs_root *log_root;
1065 struct btrfs_inode_item *inode_item;
1066
1067 log_root = alloc_log_tree(trans, root->fs_info);
1068 if (IS_ERR(log_root))
1069 return PTR_ERR(log_root);
1070
1071 log_root->last_trans = trans->transid;
1072 log_root->root_key.offset = root->root_key.objectid;
1073
1074 inode_item = &log_root->root_item.inode;
1075 inode_item->generation = cpu_to_le64(1);
1076 inode_item->size = cpu_to_le64(3);
1077 inode_item->nlink = cpu_to_le32(1);
1078 inode_item->nbytes = cpu_to_le64(root->leafsize);
1079 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1080
1081 btrfs_set_root_node(&log_root->root_item, log_root->node);
1082
1083 WARN_ON(root->log_root);
1084 root->log_root = log_root;
1085 root->log_transid = 0;
1086 return 0;
1087}
1088
1089struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1090 struct btrfs_key *location)
1091{
1092 struct btrfs_root *root;
1093 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1094 struct btrfs_path *path;
1095 struct extent_buffer *l;
1096 u64 highest_inode;
1097 u64 generation;
1098 u32 blocksize;
1099 int ret = 0;
1100
1101 root = kzalloc(sizeof(*root), GFP_NOFS);
1102 if (!root)
1103 return ERR_PTR(-ENOMEM);
1104 if (location->offset == (u64)-1) {
1105 ret = find_and_setup_root(tree_root, fs_info,
1106 location->objectid, root);
1107 if (ret) {
1108 kfree(root);
1109 return ERR_PTR(ret);
1110 }
1111 goto insert;
1112 }
1113
1114 __setup_root(tree_root->nodesize, tree_root->leafsize,
1115 tree_root->sectorsize, tree_root->stripesize,
1116 root, fs_info, location->objectid);
1117
1118 path = btrfs_alloc_path();
1119 BUG_ON(!path);
1120 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1121 if (ret != 0) {
1122 if (ret > 0)
1123 ret = -ENOENT;
1124 goto out;
1125 }
1126 l = path->nodes[0];
1127 read_extent_buffer(l, &root->root_item,
1128 btrfs_item_ptr_offset(l, path->slots[0]),
1129 sizeof(root->root_item));
1130 memcpy(&root->root_key, location, sizeof(*location));
1131 ret = 0;
1132out:
1133 btrfs_release_path(root, path);
1134 btrfs_free_path(path);
1135 if (ret) {
1136 kfree(root);
1137 return ERR_PTR(ret);
1138 }
1139 generation = btrfs_root_generation(&root->root_item);
1140 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1141 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1142 blocksize, generation);
1143 root->commit_root = btrfs_root_node(root);
1144 BUG_ON(!root->node);
1145insert:
1146 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1147 root->ref_cows = 1;
1148 ret = btrfs_find_highest_inode(root, &highest_inode);
1149 if (ret == 0) {
1150 root->highest_inode = highest_inode;
1151 root->last_inode_alloc = highest_inode;
1152 }
1153 }
1154 return root;
1155}
1156
1157struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1158 u64 root_objectid)
1159{
1160 struct btrfs_root *root;
1161
1162 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1163 return fs_info->tree_root;
1164 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1165 return fs_info->extent_root;
1166
1167 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1168 (unsigned long)root_objectid);
1169 return root;
1170}
1171
1172struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1173 struct btrfs_key *location)
1174{
1175 struct btrfs_root *root;
1176 int ret;
1177
1178 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1179 return fs_info->tree_root;
1180 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1181 return fs_info->extent_root;
1182 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1183 return fs_info->chunk_root;
1184 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1185 return fs_info->dev_root;
1186 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1187 return fs_info->csum_root;
1188
1189 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1190 (unsigned long)location->objectid);
1191 if (root)
1192 return root;
1193
1194 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1195 if (IS_ERR(root))
1196 return root;
1197
1198 set_anon_super(&root->anon_super, NULL);
1199
1200 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1201 (unsigned long)root->root_key.objectid,
1202 root);
1203 if (ret) {
1204 free_extent_buffer(root->node);
1205 kfree(root);
1206 return ERR_PTR(ret);
1207 }
1208 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1209 ret = btrfs_find_dead_roots(fs_info->tree_root,
1210 root->root_key.objectid);
1211 BUG_ON(ret);
1212 btrfs_orphan_cleanup(root);
1213 }
1214 return root;
1215}
1216
1217struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1218 struct btrfs_key *location,
1219 const char *name, int namelen)
1220{
1221 struct btrfs_root *root;
1222 int ret;
1223
1224 root = btrfs_read_fs_root_no_name(fs_info, location);
1225 if (!root)
1226 return NULL;
1227
1228 if (root->in_sysfs)
1229 return root;
1230
1231 ret = btrfs_set_root_name(root, name, namelen);
1232 if (ret) {
1233 free_extent_buffer(root->node);
1234 kfree(root);
1235 return ERR_PTR(ret);
1236 }
1237#if 0
1238 ret = btrfs_sysfs_add_root(root);
1239 if (ret) {
1240 free_extent_buffer(root->node);
1241 kfree(root->name);
1242 kfree(root);
1243 return ERR_PTR(ret);
1244 }
1245#endif
1246 root->in_sysfs = 1;
1247 return root;
1248}
1249
1250static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1251{
1252 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1253 int ret = 0;
1254 struct btrfs_device *device;
1255 struct backing_dev_info *bdi;
1256
1257 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1258 if (!device->bdev)
1259 continue;
1260 bdi = blk_get_backing_dev_info(device->bdev);
1261 if (bdi && bdi_congested(bdi, bdi_bits)) {
1262 ret = 1;
1263 break;
1264 }
1265 }
1266 return ret;
1267}
1268
1269/*
1270 * this unplugs every device on the box, and it is only used when page
1271 * is null
1272 */
1273static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1274{
1275 struct btrfs_device *device;
1276 struct btrfs_fs_info *info;
1277
1278 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1279 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1280 if (!device->bdev)
1281 continue;
1282
1283 bdi = blk_get_backing_dev_info(device->bdev);
1284 if (bdi->unplug_io_fn)
1285 bdi->unplug_io_fn(bdi, page);
1286 }
1287}
1288
1289static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1290{
1291 struct inode *inode;
1292 struct extent_map_tree *em_tree;
1293 struct extent_map *em;
1294 struct address_space *mapping;
1295 u64 offset;
1296
1297 /* the generic O_DIRECT read code does this */
1298 if (1 || !page) {
1299 __unplug_io_fn(bdi, page);
1300 return;
1301 }
1302
1303 /*
1304 * page->mapping may change at any time. Get a consistent copy
1305 * and use that for everything below
1306 */
1307 smp_mb();
1308 mapping = page->mapping;
1309 if (!mapping)
1310 return;
1311
1312 inode = mapping->host;
1313
1314 /*
1315 * don't do the expensive searching for a small number of
1316 * devices
1317 */
1318 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1319 __unplug_io_fn(bdi, page);
1320 return;
1321 }
1322
1323 offset = page_offset(page);
1324
1325 em_tree = &BTRFS_I(inode)->extent_tree;
1326 spin_lock(&em_tree->lock);
1327 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1328 spin_unlock(&em_tree->lock);
1329 if (!em) {
1330 __unplug_io_fn(bdi, page);
1331 return;
1332 }
1333
1334 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1335 free_extent_map(em);
1336 __unplug_io_fn(bdi, page);
1337 return;
1338 }
1339 offset = offset - em->start;
1340 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1341 em->block_start + offset, page);
1342 free_extent_map(em);
1343}
1344
1345static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1346{
1347 bdi_init(bdi);
1348 bdi->ra_pages = default_backing_dev_info.ra_pages;
1349 bdi->state = 0;
1350 bdi->capabilities = default_backing_dev_info.capabilities;
1351 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1352 bdi->unplug_io_data = info;
1353 bdi->congested_fn = btrfs_congested_fn;
1354 bdi->congested_data = info;
1355 return 0;
1356}
1357
1358static int bio_ready_for_csum(struct bio *bio)
1359{
1360 u64 length = 0;
1361 u64 buf_len = 0;
1362 u64 start = 0;
1363 struct page *page;
1364 struct extent_io_tree *io_tree = NULL;
1365 struct btrfs_fs_info *info = NULL;
1366 struct bio_vec *bvec;
1367 int i;
1368 int ret;
1369
1370 bio_for_each_segment(bvec, bio, i) {
1371 page = bvec->bv_page;
1372 if (page->private == EXTENT_PAGE_PRIVATE) {
1373 length += bvec->bv_len;
1374 continue;
1375 }
1376 if (!page->private) {
1377 length += bvec->bv_len;
1378 continue;
1379 }
1380 length = bvec->bv_len;
1381 buf_len = page->private >> 2;
1382 start = page_offset(page) + bvec->bv_offset;
1383 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1384 info = BTRFS_I(page->mapping->host)->root->fs_info;
1385 }
1386 /* are we fully contained in this bio? */
1387 if (buf_len <= length)
1388 return 1;
1389
1390 ret = extent_range_uptodate(io_tree, start + length,
1391 start + buf_len - 1);
1392 return ret;
1393}
1394
1395/*
1396 * called by the kthread helper functions to finally call the bio end_io
1397 * functions. This is where read checksum verification actually happens
1398 */
1399static void end_workqueue_fn(struct btrfs_work *work)
1400{
1401 struct bio *bio;
1402 struct end_io_wq *end_io_wq;
1403 struct btrfs_fs_info *fs_info;
1404 int error;
1405
1406 end_io_wq = container_of(work, struct end_io_wq, work);
1407 bio = end_io_wq->bio;
1408 fs_info = end_io_wq->info;
1409
1410 /* metadata bio reads are special because the whole tree block must
1411 * be checksummed at once. This makes sure the entire block is in
1412 * ram and up to date before trying to verify things. For
1413 * blocksize <= pagesize, it is basically a noop
1414 */
1415 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1416 !bio_ready_for_csum(bio)) {
1417 btrfs_queue_worker(&fs_info->endio_meta_workers,
1418 &end_io_wq->work);
1419 return;
1420 }
1421 error = end_io_wq->error;
1422 bio->bi_private = end_io_wq->private;
1423 bio->bi_end_io = end_io_wq->end_io;
1424 kfree(end_io_wq);
1425 bio_endio(bio, error);
1426}
1427
1428static int cleaner_kthread(void *arg)
1429{
1430 struct btrfs_root *root = arg;
1431
1432 do {
1433 smp_mb();
1434 if (root->fs_info->closing)
1435 break;
1436
1437 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1438 mutex_lock(&root->fs_info->cleaner_mutex);
1439 btrfs_clean_old_snapshots(root);
1440 mutex_unlock(&root->fs_info->cleaner_mutex);
1441
1442 if (freezing(current)) {
1443 refrigerator();
1444 } else {
1445 smp_mb();
1446 if (root->fs_info->closing)
1447 break;
1448 set_current_state(TASK_INTERRUPTIBLE);
1449 schedule();
1450 __set_current_state(TASK_RUNNING);
1451 }
1452 } while (!kthread_should_stop());
1453 return 0;
1454}
1455
1456static int transaction_kthread(void *arg)
1457{
1458 struct btrfs_root *root = arg;
1459 struct btrfs_trans_handle *trans;
1460 struct btrfs_transaction *cur;
1461 unsigned long now;
1462 unsigned long delay;
1463 int ret;
1464
1465 do {
1466 smp_mb();
1467 if (root->fs_info->closing)
1468 break;
1469
1470 delay = HZ * 30;
1471 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1472 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1473
1474 mutex_lock(&root->fs_info->trans_mutex);
1475 cur = root->fs_info->running_transaction;
1476 if (!cur) {
1477 mutex_unlock(&root->fs_info->trans_mutex);
1478 goto sleep;
1479 }
1480
1481 now = get_seconds();
1482 if (now < cur->start_time || now - cur->start_time < 30) {
1483 mutex_unlock(&root->fs_info->trans_mutex);
1484 delay = HZ * 5;
1485 goto sleep;
1486 }
1487 mutex_unlock(&root->fs_info->trans_mutex);
1488 trans = btrfs_start_transaction(root, 1);
1489 ret = btrfs_commit_transaction(trans, root);
1490
1491sleep:
1492 wake_up_process(root->fs_info->cleaner_kthread);
1493 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1494
1495 if (freezing(current)) {
1496 refrigerator();
1497 } else {
1498 if (root->fs_info->closing)
1499 break;
1500 set_current_state(TASK_INTERRUPTIBLE);
1501 schedule_timeout(delay);
1502 __set_current_state(TASK_RUNNING);
1503 }
1504 } while (!kthread_should_stop());
1505 return 0;
1506}
1507
1508struct btrfs_root *open_ctree(struct super_block *sb,
1509 struct btrfs_fs_devices *fs_devices,
1510 char *options)
1511{
1512 u32 sectorsize;
1513 u32 nodesize;
1514 u32 leafsize;
1515 u32 blocksize;
1516 u32 stripesize;
1517 u64 generation;
1518 u64 features;
1519 struct btrfs_key location;
1520 struct buffer_head *bh;
1521 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1522 GFP_NOFS);
1523 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1524 GFP_NOFS);
1525 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1526 GFP_NOFS);
1527 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1528 GFP_NOFS);
1529 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1530 GFP_NOFS);
1531 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1532 GFP_NOFS);
1533 struct btrfs_root *log_tree_root;
1534
1535 int ret;
1536 int err = -EINVAL;
1537
1538 struct btrfs_super_block *disk_super;
1539
1540 if (!extent_root || !tree_root || !fs_info ||
1541 !chunk_root || !dev_root || !csum_root) {
1542 err = -ENOMEM;
1543 goto fail;
1544 }
1545 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1546 INIT_LIST_HEAD(&fs_info->trans_list);
1547 INIT_LIST_HEAD(&fs_info->dead_roots);
1548 INIT_LIST_HEAD(&fs_info->hashers);
1549 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1550 INIT_LIST_HEAD(&fs_info->ordered_operations);
1551 spin_lock_init(&fs_info->delalloc_lock);
1552 spin_lock_init(&fs_info->new_trans_lock);
1553 spin_lock_init(&fs_info->ref_cache_lock);
1554
1555 init_completion(&fs_info->kobj_unregister);
1556 fs_info->tree_root = tree_root;
1557 fs_info->extent_root = extent_root;
1558 fs_info->csum_root = csum_root;
1559 fs_info->chunk_root = chunk_root;
1560 fs_info->dev_root = dev_root;
1561 fs_info->fs_devices = fs_devices;
1562 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1563 INIT_LIST_HEAD(&fs_info->space_info);
1564 btrfs_mapping_init(&fs_info->mapping_tree);
1565 atomic_set(&fs_info->nr_async_submits, 0);
1566 atomic_set(&fs_info->async_delalloc_pages, 0);
1567 atomic_set(&fs_info->async_submit_draining, 0);
1568 atomic_set(&fs_info->nr_async_bios, 0);
1569 fs_info->sb = sb;
1570 fs_info->max_extent = (u64)-1;
1571 fs_info->max_inline = 8192 * 1024;
1572 setup_bdi(fs_info, &fs_info->bdi);
1573 fs_info->btree_inode = new_inode(sb);
1574 fs_info->btree_inode->i_ino = 1;
1575 fs_info->btree_inode->i_nlink = 1;
1576 fs_info->metadata_ratio = 8;
1577
1578 fs_info->thread_pool_size = min_t(unsigned long,
1579 num_online_cpus() + 2, 8);
1580
1581 INIT_LIST_HEAD(&fs_info->ordered_extents);
1582 spin_lock_init(&fs_info->ordered_extent_lock);
1583
1584 sb->s_blocksize = 4096;
1585 sb->s_blocksize_bits = blksize_bits(4096);
1586
1587 /*
1588 * we set the i_size on the btree inode to the max possible int.
1589 * the real end of the address space is determined by all of
1590 * the devices in the system
1591 */
1592 fs_info->btree_inode->i_size = OFFSET_MAX;
1593 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1594 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1595
1596 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1597 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1598 fs_info->btree_inode->i_mapping,
1599 GFP_NOFS);
1600 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1601 GFP_NOFS);
1602
1603 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1604
1605 spin_lock_init(&fs_info->block_group_cache_lock);
1606 fs_info->block_group_cache_tree.rb_node = NULL;
1607
1608 extent_io_tree_init(&fs_info->pinned_extents,
1609 fs_info->btree_inode->i_mapping, GFP_NOFS);
1610 fs_info->do_barriers = 1;
1611
1612 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1613 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1614 sizeof(struct btrfs_key));
1615 insert_inode_hash(fs_info->btree_inode);
1616
1617 mutex_init(&fs_info->trans_mutex);
1618 mutex_init(&fs_info->ordered_operations_mutex);
1619 mutex_init(&fs_info->tree_log_mutex);
1620 mutex_init(&fs_info->drop_mutex);
1621 mutex_init(&fs_info->chunk_mutex);
1622 mutex_init(&fs_info->transaction_kthread_mutex);
1623 mutex_init(&fs_info->cleaner_mutex);
1624 mutex_init(&fs_info->volume_mutex);
1625 mutex_init(&fs_info->tree_reloc_mutex);
1626
1627 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1628 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1629
1630 init_waitqueue_head(&fs_info->transaction_throttle);
1631 init_waitqueue_head(&fs_info->transaction_wait);
1632 init_waitqueue_head(&fs_info->async_submit_wait);
1633
1634 __setup_root(4096, 4096, 4096, 4096, tree_root,
1635 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1636
1637
1638 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1639 if (!bh)
1640 goto fail_iput;
1641
1642 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1643 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1644 sizeof(fs_info->super_for_commit));
1645 brelse(bh);
1646
1647 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1648
1649 disk_super = &fs_info->super_copy;
1650 if (!btrfs_super_root(disk_super))
1651 goto fail_iput;
1652
1653 ret = btrfs_parse_options(tree_root, options);
1654 if (ret) {
1655 err = ret;
1656 goto fail_iput;
1657 }
1658
1659 features = btrfs_super_incompat_flags(disk_super) &
1660 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1661 if (features) {
1662 printk(KERN_ERR "BTRFS: couldn't mount because of "
1663 "unsupported optional features (%Lx).\n",
1664 (unsigned long long)features);
1665 err = -EINVAL;
1666 goto fail_iput;
1667 }
1668
1669 features = btrfs_super_incompat_flags(disk_super);
1670 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
1671 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1672 btrfs_set_super_incompat_flags(disk_super, features);
1673 }
1674
1675 features = btrfs_super_compat_ro_flags(disk_super) &
1676 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1677 if (!(sb->s_flags & MS_RDONLY) && features) {
1678 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1679 "unsupported option features (%Lx).\n",
1680 (unsigned long long)features);
1681 err = -EINVAL;
1682 goto fail_iput;
1683 }
1684
1685 /*
1686 * we need to start all the end_io workers up front because the
1687 * queue work function gets called at interrupt time, and so it
1688 * cannot dynamically grow.
1689 */
1690 btrfs_init_workers(&fs_info->workers, "worker",
1691 fs_info->thread_pool_size);
1692
1693 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1694 fs_info->thread_pool_size);
1695
1696 btrfs_init_workers(&fs_info->submit_workers, "submit",
1697 min_t(u64, fs_devices->num_devices,
1698 fs_info->thread_pool_size));
1699
1700 /* a higher idle thresh on the submit workers makes it much more
1701 * likely that bios will be send down in a sane order to the
1702 * devices
1703 */
1704 fs_info->submit_workers.idle_thresh = 64;
1705
1706 fs_info->workers.idle_thresh = 16;
1707 fs_info->workers.ordered = 1;
1708
1709 fs_info->delalloc_workers.idle_thresh = 2;
1710 fs_info->delalloc_workers.ordered = 1;
1711
1712 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1713 btrfs_init_workers(&fs_info->endio_workers, "endio",
1714 fs_info->thread_pool_size);
1715 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1716 fs_info->thread_pool_size);
1717 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1718 "endio-meta-write", fs_info->thread_pool_size);
1719 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1720 fs_info->thread_pool_size);
1721
1722 /*
1723 * endios are largely parallel and should have a very
1724 * low idle thresh
1725 */
1726 fs_info->endio_workers.idle_thresh = 4;
1727 fs_info->endio_meta_workers.idle_thresh = 4;
1728
1729 fs_info->endio_write_workers.idle_thresh = 64;
1730 fs_info->endio_meta_write_workers.idle_thresh = 64;
1731
1732 btrfs_start_workers(&fs_info->workers, 1);
1733 btrfs_start_workers(&fs_info->submit_workers, 1);
1734 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1735 btrfs_start_workers(&fs_info->fixup_workers, 1);
1736 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1737 btrfs_start_workers(&fs_info->endio_meta_workers,
1738 fs_info->thread_pool_size);
1739 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1740 fs_info->thread_pool_size);
1741 btrfs_start_workers(&fs_info->endio_write_workers,
1742 fs_info->thread_pool_size);
1743
1744 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1745 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1746 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1747
1748 nodesize = btrfs_super_nodesize(disk_super);
1749 leafsize = btrfs_super_leafsize(disk_super);
1750 sectorsize = btrfs_super_sectorsize(disk_super);
1751 stripesize = btrfs_super_stripesize(disk_super);
1752 tree_root->nodesize = nodesize;
1753 tree_root->leafsize = leafsize;
1754 tree_root->sectorsize = sectorsize;
1755 tree_root->stripesize = stripesize;
1756
1757 sb->s_blocksize = sectorsize;
1758 sb->s_blocksize_bits = blksize_bits(sectorsize);
1759
1760 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1761 sizeof(disk_super->magic))) {
1762 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1763 goto fail_sb_buffer;
1764 }
1765
1766 mutex_lock(&fs_info->chunk_mutex);
1767 ret = btrfs_read_sys_array(tree_root);
1768 mutex_unlock(&fs_info->chunk_mutex);
1769 if (ret) {
1770 printk(KERN_WARNING "btrfs: failed to read the system "
1771 "array on %s\n", sb->s_id);
1772 goto fail_sb_buffer;
1773 }
1774
1775 blocksize = btrfs_level_size(tree_root,
1776 btrfs_super_chunk_root_level(disk_super));
1777 generation = btrfs_super_chunk_root_generation(disk_super);
1778
1779 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1780 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1781
1782 chunk_root->node = read_tree_block(chunk_root,
1783 btrfs_super_chunk_root(disk_super),
1784 blocksize, generation);
1785 BUG_ON(!chunk_root->node);
1786 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1787 chunk_root->commit_root = btrfs_root_node(chunk_root);
1788
1789 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1790 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1791 BTRFS_UUID_SIZE);
1792
1793 mutex_lock(&fs_info->chunk_mutex);
1794 ret = btrfs_read_chunk_tree(chunk_root);
1795 mutex_unlock(&fs_info->chunk_mutex);
1796 if (ret) {
1797 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1798 sb->s_id);
1799 goto fail_chunk_root;
1800 }
1801
1802 btrfs_close_extra_devices(fs_devices);
1803
1804 blocksize = btrfs_level_size(tree_root,
1805 btrfs_super_root_level(disk_super));
1806 generation = btrfs_super_generation(disk_super);
1807
1808 tree_root->node = read_tree_block(tree_root,
1809 btrfs_super_root(disk_super),
1810 blocksize, generation);
1811 if (!tree_root->node)
1812 goto fail_chunk_root;
1813 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1814 tree_root->commit_root = btrfs_root_node(tree_root);
1815
1816 ret = find_and_setup_root(tree_root, fs_info,
1817 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1818 if (ret)
1819 goto fail_tree_root;
1820 extent_root->track_dirty = 1;
1821
1822 ret = find_and_setup_root(tree_root, fs_info,
1823 BTRFS_DEV_TREE_OBJECTID, dev_root);
1824 if (ret)
1825 goto fail_extent_root;
1826 dev_root->track_dirty = 1;
1827
1828 ret = find_and_setup_root(tree_root, fs_info,
1829 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1830 if (ret)
1831 goto fail_dev_root;
1832
1833 csum_root->track_dirty = 1;
1834
1835 btrfs_read_block_groups(extent_root);
1836
1837 fs_info->generation = generation;
1838 fs_info->last_trans_committed = generation;
1839 fs_info->data_alloc_profile = (u64)-1;
1840 fs_info->metadata_alloc_profile = (u64)-1;
1841 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1842 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1843 "btrfs-cleaner");
1844 if (IS_ERR(fs_info->cleaner_kthread))
1845 goto fail_csum_root;
1846
1847 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1848 tree_root,
1849 "btrfs-transaction");
1850 if (IS_ERR(fs_info->transaction_kthread))
1851 goto fail_cleaner;
1852
1853 if (btrfs_super_log_root(disk_super) != 0) {
1854 u64 bytenr = btrfs_super_log_root(disk_super);
1855
1856 if (fs_devices->rw_devices == 0) {
1857 printk(KERN_WARNING "Btrfs log replay required "
1858 "on RO media\n");
1859 err = -EIO;
1860 goto fail_trans_kthread;
1861 }
1862 blocksize =
1863 btrfs_level_size(tree_root,
1864 btrfs_super_log_root_level(disk_super));
1865
1866 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1867 GFP_NOFS);
1868
1869 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1870 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1871
1872 log_tree_root->node = read_tree_block(tree_root, bytenr,
1873 blocksize,
1874 generation + 1);
1875 ret = btrfs_recover_log_trees(log_tree_root);
1876 BUG_ON(ret);
1877
1878 if (sb->s_flags & MS_RDONLY) {
1879 ret = btrfs_commit_super(tree_root);
1880 BUG_ON(ret);
1881 }
1882 }
1883
1884 if (!(sb->s_flags & MS_RDONLY)) {
1885 ret = btrfs_recover_relocation(tree_root);
1886 BUG_ON(ret);
1887 }
1888
1889 location.objectid = BTRFS_FS_TREE_OBJECTID;
1890 location.type = BTRFS_ROOT_ITEM_KEY;
1891 location.offset = (u64)-1;
1892
1893 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1894 if (!fs_info->fs_root)
1895 goto fail_trans_kthread;
1896 return tree_root;
1897
1898fail_trans_kthread:
1899 kthread_stop(fs_info->transaction_kthread);
1900fail_cleaner:
1901 kthread_stop(fs_info->cleaner_kthread);
1902
1903 /*
1904 * make sure we're done with the btree inode before we stop our
1905 * kthreads
1906 */
1907 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1908 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1909
1910fail_csum_root:
1911 free_extent_buffer(csum_root->node);
1912 free_extent_buffer(csum_root->commit_root);
1913fail_dev_root:
1914 free_extent_buffer(dev_root->node);
1915 free_extent_buffer(dev_root->commit_root);
1916fail_extent_root:
1917 free_extent_buffer(extent_root->node);
1918 free_extent_buffer(extent_root->commit_root);
1919fail_tree_root:
1920 free_extent_buffer(tree_root->node);
1921 free_extent_buffer(tree_root->commit_root);
1922fail_chunk_root:
1923 free_extent_buffer(chunk_root->node);
1924 free_extent_buffer(chunk_root->commit_root);
1925fail_sb_buffer:
1926 btrfs_stop_workers(&fs_info->fixup_workers);
1927 btrfs_stop_workers(&fs_info->delalloc_workers);
1928 btrfs_stop_workers(&fs_info->workers);
1929 btrfs_stop_workers(&fs_info->endio_workers);
1930 btrfs_stop_workers(&fs_info->endio_meta_workers);
1931 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1932 btrfs_stop_workers(&fs_info->endio_write_workers);
1933 btrfs_stop_workers(&fs_info->submit_workers);
1934fail_iput:
1935 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1936 iput(fs_info->btree_inode);
1937
1938 btrfs_close_devices(fs_info->fs_devices);
1939 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1940 bdi_destroy(&fs_info->bdi);
1941
1942fail:
1943 kfree(extent_root);
1944 kfree(tree_root);
1945 kfree(fs_info);
1946 kfree(chunk_root);
1947 kfree(dev_root);
1948 kfree(csum_root);
1949 return ERR_PTR(err);
1950}
1951
1952static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1953{
1954 char b[BDEVNAME_SIZE];
1955
1956 if (uptodate) {
1957 set_buffer_uptodate(bh);
1958 } else {
1959 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1960 printk(KERN_WARNING "lost page write due to "
1961 "I/O error on %s\n",
1962 bdevname(bh->b_bdev, b));
1963 }
1964 /* note, we dont' set_buffer_write_io_error because we have
1965 * our own ways of dealing with the IO errors
1966 */
1967 clear_buffer_uptodate(bh);
1968 }
1969 unlock_buffer(bh);
1970 put_bh(bh);
1971}
1972
1973struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1974{
1975 struct buffer_head *bh;
1976 struct buffer_head *latest = NULL;
1977 struct btrfs_super_block *super;
1978 int i;
1979 u64 transid = 0;
1980 u64 bytenr;
1981
1982 /* we would like to check all the supers, but that would make
1983 * a btrfs mount succeed after a mkfs from a different FS.
1984 * So, we need to add a special mount option to scan for
1985 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1986 */
1987 for (i = 0; i < 1; i++) {
1988 bytenr = btrfs_sb_offset(i);
1989 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1990 break;
1991 bh = __bread(bdev, bytenr / 4096, 4096);
1992 if (!bh)
1993 continue;
1994
1995 super = (struct btrfs_super_block *)bh->b_data;
1996 if (btrfs_super_bytenr(super) != bytenr ||
1997 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1998 sizeof(super->magic))) {
1999 brelse(bh);
2000 continue;
2001 }
2002
2003 if (!latest || btrfs_super_generation(super) > transid) {
2004 brelse(latest);
2005 latest = bh;
2006 transid = btrfs_super_generation(super);
2007 } else {
2008 brelse(bh);
2009 }
2010 }
2011 return latest;
2012}
2013
2014static int write_dev_supers(struct btrfs_device *device,
2015 struct btrfs_super_block *sb,
2016 int do_barriers, int wait, int max_mirrors)
2017{
2018 struct buffer_head *bh;
2019 int i;
2020 int ret;
2021 int errors = 0;
2022 u32 crc;
2023 u64 bytenr;
2024 int last_barrier = 0;
2025
2026 if (max_mirrors == 0)
2027 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2028
2029 /* make sure only the last submit_bh does a barrier */
2030 if (do_barriers) {
2031 for (i = 0; i < max_mirrors; i++) {
2032 bytenr = btrfs_sb_offset(i);
2033 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2034 device->total_bytes)
2035 break;
2036 last_barrier = i;
2037 }
2038 }
2039
2040 for (i = 0; i < max_mirrors; i++) {
2041 bytenr = btrfs_sb_offset(i);
2042 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2043 break;
2044
2045 if (wait) {
2046 bh = __find_get_block(device->bdev, bytenr / 4096,
2047 BTRFS_SUPER_INFO_SIZE);
2048 BUG_ON(!bh);
2049 brelse(bh);
2050 wait_on_buffer(bh);
2051 if (buffer_uptodate(bh)) {
2052 brelse(bh);
2053 continue;
2054 }
2055 } else {
2056 btrfs_set_super_bytenr(sb, bytenr);
2057
2058 crc = ~(u32)0;
2059 crc = btrfs_csum_data(NULL, (char *)sb +
2060 BTRFS_CSUM_SIZE, crc,
2061 BTRFS_SUPER_INFO_SIZE -
2062 BTRFS_CSUM_SIZE);
2063 btrfs_csum_final(crc, sb->csum);
2064
2065 bh = __getblk(device->bdev, bytenr / 4096,
2066 BTRFS_SUPER_INFO_SIZE);
2067 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2068
2069 set_buffer_uptodate(bh);
2070 get_bh(bh);
2071 lock_buffer(bh);
2072 bh->b_end_io = btrfs_end_buffer_write_sync;
2073 }
2074
2075 if (i == last_barrier && do_barriers && device->barriers) {
2076 ret = submit_bh(WRITE_BARRIER, bh);
2077 if (ret == -EOPNOTSUPP) {
2078 printk("btrfs: disabling barriers on dev %s\n",
2079 device->name);
2080 set_buffer_uptodate(bh);
2081 device->barriers = 0;
2082 get_bh(bh);
2083 lock_buffer(bh);
2084 ret = submit_bh(WRITE_SYNC, bh);
2085 }
2086 } else {
2087 ret = submit_bh(WRITE_SYNC, bh);
2088 }
2089
2090 if (!ret && wait) {
2091 wait_on_buffer(bh);
2092 if (!buffer_uptodate(bh))
2093 errors++;
2094 } else if (ret) {
2095 errors++;
2096 }
2097 if (wait)
2098 brelse(bh);
2099 }
2100 return errors < i ? 0 : -1;
2101}
2102
2103int write_all_supers(struct btrfs_root *root, int max_mirrors)
2104{
2105 struct list_head *head = &root->fs_info->fs_devices->devices;
2106 struct btrfs_device *dev;
2107 struct btrfs_super_block *sb;
2108 struct btrfs_dev_item *dev_item;
2109 int ret;
2110 int do_barriers;
2111 int max_errors;
2112 int total_errors = 0;
2113 u64 flags;
2114
2115 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2116 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2117
2118 sb = &root->fs_info->super_for_commit;
2119 dev_item = &sb->dev_item;
2120 list_for_each_entry(dev, head, dev_list) {
2121 if (!dev->bdev) {
2122 total_errors++;
2123 continue;
2124 }
2125 if (!dev->in_fs_metadata || !dev->writeable)
2126 continue;
2127
2128 btrfs_set_stack_device_generation(dev_item, 0);
2129 btrfs_set_stack_device_type(dev_item, dev->type);
2130 btrfs_set_stack_device_id(dev_item, dev->devid);
2131 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2132 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2133 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2134 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2135 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2136 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2137 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2138
2139 flags = btrfs_super_flags(sb);
2140 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2141
2142 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2143 if (ret)
2144 total_errors++;
2145 }
2146 if (total_errors > max_errors) {
2147 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2148 total_errors);
2149 BUG();
2150 }
2151
2152 total_errors = 0;
2153 list_for_each_entry(dev, head, dev_list) {
2154 if (!dev->bdev)
2155 continue;
2156 if (!dev->in_fs_metadata || !dev->writeable)
2157 continue;
2158
2159 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2160 if (ret)
2161 total_errors++;
2162 }
2163 if (total_errors > max_errors) {
2164 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2165 total_errors);
2166 BUG();
2167 }
2168 return 0;
2169}
2170
2171int write_ctree_super(struct btrfs_trans_handle *trans,
2172 struct btrfs_root *root, int max_mirrors)
2173{
2174 int ret;
2175
2176 ret = write_all_supers(root, max_mirrors);
2177 return ret;
2178}
2179
2180int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2181{
2182 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2183 radix_tree_delete(&fs_info->fs_roots_radix,
2184 (unsigned long)root->root_key.objectid);
2185 if (root->anon_super.s_dev) {
2186 down_write(&root->anon_super.s_umount);
2187 kill_anon_super(&root->anon_super);
2188 }
2189 if (root->node)
2190 free_extent_buffer(root->node);
2191 if (root->commit_root)
2192 free_extent_buffer(root->commit_root);
2193 kfree(root->name);
2194 kfree(root);
2195 return 0;
2196}
2197
2198static int del_fs_roots(struct btrfs_fs_info *fs_info)
2199{
2200 int ret;
2201 struct btrfs_root *gang[8];
2202 int i;
2203
2204 while (1) {
2205 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2206 (void **)gang, 0,
2207 ARRAY_SIZE(gang));
2208 if (!ret)
2209 break;
2210 for (i = 0; i < ret; i++)
2211 btrfs_free_fs_root(fs_info, gang[i]);
2212 }
2213 return 0;
2214}
2215
2216int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2217{
2218 u64 root_objectid = 0;
2219 struct btrfs_root *gang[8];
2220 int i;
2221 int ret;
2222
2223 while (1) {
2224 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2225 (void **)gang, root_objectid,
2226 ARRAY_SIZE(gang));
2227 if (!ret)
2228 break;
2229
2230 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2231 for (i = 0; i < ret; i++) {
2232 root_objectid = gang[i]->root_key.objectid;
2233 ret = btrfs_find_dead_roots(fs_info->tree_root,
2234 root_objectid);
2235 BUG_ON(ret);
2236 btrfs_orphan_cleanup(gang[i]);
2237 }
2238 root_objectid++;
2239 }
2240 return 0;
2241}
2242
2243int btrfs_commit_super(struct btrfs_root *root)
2244{
2245 struct btrfs_trans_handle *trans;
2246 int ret;
2247
2248 mutex_lock(&root->fs_info->cleaner_mutex);
2249 btrfs_clean_old_snapshots(root);
2250 mutex_unlock(&root->fs_info->cleaner_mutex);
2251 trans = btrfs_start_transaction(root, 1);
2252 ret = btrfs_commit_transaction(trans, root);
2253 BUG_ON(ret);
2254 /* run commit again to drop the original snapshot */
2255 trans = btrfs_start_transaction(root, 1);
2256 btrfs_commit_transaction(trans, root);
2257 ret = btrfs_write_and_wait_transaction(NULL, root);
2258 BUG_ON(ret);
2259
2260 ret = write_ctree_super(NULL, root, 0);
2261 return ret;
2262}
2263
2264int close_ctree(struct btrfs_root *root)
2265{
2266 struct btrfs_fs_info *fs_info = root->fs_info;
2267 int ret;
2268
2269 fs_info->closing = 1;
2270 smp_mb();
2271
2272 kthread_stop(root->fs_info->transaction_kthread);
2273 kthread_stop(root->fs_info->cleaner_kthread);
2274
2275 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2276 ret = btrfs_commit_super(root);
2277 if (ret)
2278 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2279 }
2280
2281 if (fs_info->delalloc_bytes) {
2282 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2283 (unsigned long long)fs_info->delalloc_bytes);
2284 }
2285 if (fs_info->total_ref_cache_size) {
2286 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2287 (unsigned long long)fs_info->total_ref_cache_size);
2288 }
2289
2290 free_extent_buffer(fs_info->extent_root->node);
2291 free_extent_buffer(fs_info->extent_root->commit_root);
2292 free_extent_buffer(fs_info->tree_root->node);
2293 free_extent_buffer(fs_info->tree_root->commit_root);
2294 free_extent_buffer(root->fs_info->chunk_root->node);
2295 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2296 free_extent_buffer(root->fs_info->dev_root->node);
2297 free_extent_buffer(root->fs_info->dev_root->commit_root);
2298 free_extent_buffer(root->fs_info->csum_root->node);
2299 free_extent_buffer(root->fs_info->csum_root->commit_root);
2300
2301 btrfs_free_block_groups(root->fs_info);
2302
2303 del_fs_roots(fs_info);
2304
2305 iput(fs_info->btree_inode);
2306
2307 btrfs_stop_workers(&fs_info->fixup_workers);
2308 btrfs_stop_workers(&fs_info->delalloc_workers);
2309 btrfs_stop_workers(&fs_info->workers);
2310 btrfs_stop_workers(&fs_info->endio_workers);
2311 btrfs_stop_workers(&fs_info->endio_meta_workers);
2312 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2313 btrfs_stop_workers(&fs_info->endio_write_workers);
2314 btrfs_stop_workers(&fs_info->submit_workers);
2315
2316 btrfs_close_devices(fs_info->fs_devices);
2317 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2318
2319 bdi_destroy(&fs_info->bdi);
2320
2321 kfree(fs_info->extent_root);
2322 kfree(fs_info->tree_root);
2323 kfree(fs_info->chunk_root);
2324 kfree(fs_info->dev_root);
2325 kfree(fs_info->csum_root);
2326 return 0;
2327}
2328
2329int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2330{
2331 int ret;
2332 struct inode *btree_inode = buf->first_page->mapping->host;
2333
2334 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2335 if (!ret)
2336 return ret;
2337
2338 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2339 parent_transid);
2340 return !ret;
2341}
2342
2343int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2344{
2345 struct inode *btree_inode = buf->first_page->mapping->host;
2346 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2347 buf);
2348}
2349
2350void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2351{
2352 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2353 u64 transid = btrfs_header_generation(buf);
2354 struct inode *btree_inode = root->fs_info->btree_inode;
2355 int was_dirty;
2356
2357 btrfs_assert_tree_locked(buf);
2358 if (transid != root->fs_info->generation) {
2359 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2360 "found %llu running %llu\n",
2361 (unsigned long long)buf->start,
2362 (unsigned long long)transid,
2363 (unsigned long long)root->fs_info->generation);
2364 WARN_ON(1);
2365 }
2366 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2367 buf);
2368 if (!was_dirty) {
2369 spin_lock(&root->fs_info->delalloc_lock);
2370 root->fs_info->dirty_metadata_bytes += buf->len;
2371 spin_unlock(&root->fs_info->delalloc_lock);
2372 }
2373}
2374
2375void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2376{
2377 /*
2378 * looks as though older kernels can get into trouble with
2379 * this code, they end up stuck in balance_dirty_pages forever
2380 */
2381 struct extent_io_tree *tree;
2382 u64 num_dirty;
2383 u64 start = 0;
2384 unsigned long thresh = 32 * 1024 * 1024;
2385 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2386
2387 if (current->flags & PF_MEMALLOC)
2388 return;
2389
2390 num_dirty = count_range_bits(tree, &start, (u64)-1,
2391 thresh, EXTENT_DIRTY);
2392 if (num_dirty > thresh) {
2393 balance_dirty_pages_ratelimited_nr(
2394 root->fs_info->btree_inode->i_mapping, 1);
2395 }
2396 return;
2397}
2398
2399int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2400{
2401 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2402 int ret;
2403 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2404 if (ret == 0)
2405 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2406 return ret;
2407}
2408
2409int btree_lock_page_hook(struct page *page)
2410{
2411 struct inode *inode = page->mapping->host;
2412 struct btrfs_root *root = BTRFS_I(inode)->root;
2413 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2414 struct extent_buffer *eb;
2415 unsigned long len;
2416 u64 bytenr = page_offset(page);
2417
2418 if (page->private == EXTENT_PAGE_PRIVATE)
2419 goto out;
2420
2421 len = page->private >> 2;
2422 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2423 if (!eb)
2424 goto out;
2425
2426 btrfs_tree_lock(eb);
2427 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2428
2429 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2430 spin_lock(&root->fs_info->delalloc_lock);
2431 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2432 root->fs_info->dirty_metadata_bytes -= eb->len;
2433 else
2434 WARN_ON(1);
2435 spin_unlock(&root->fs_info->delalloc_lock);
2436 }
2437
2438 btrfs_tree_unlock(eb);
2439 free_extent_buffer(eb);
2440out:
2441 lock_page(page);
2442 return 0;
2443}
2444
2445static struct extent_io_ops btree_extent_io_ops = {
2446 .write_cache_pages_lock_hook = btree_lock_page_hook,
2447 .readpage_end_io_hook = btree_readpage_end_io_hook,
2448 .submit_bio_hook = btree_submit_bio_hook,
2449 /* note we're sharing with inode.c for the merge bio hook */
2450 .merge_bio_hook = btrfs_merge_bio_hook,
2451};
Linux 6.x block layer and io_uring tree(s)