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Btrfs: hash_lock is no longer needed
[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 "ref-cache.h"
40#include "tree-log.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/*
79 * extents on the btree inode are pretty simple, there's one extent
80 * that covers the entire device
81 */
82static struct extent_map *btree_get_extent(struct inode *inode,
83 struct page *page, size_t page_offset, u64 start, u64 len,
84 int create)
85{
86 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
87 struct extent_map *em;
88 int ret;
89
90 spin_lock(&em_tree->lock);
91 em = lookup_extent_mapping(em_tree, start, len);
92 if (em) {
93 em->bdev =
94 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
95 spin_unlock(&em_tree->lock);
96 goto out;
97 }
98 spin_unlock(&em_tree->lock);
99
100 em = alloc_extent_map(GFP_NOFS);
101 if (!em) {
102 em = ERR_PTR(-ENOMEM);
103 goto out;
104 }
105 em->start = 0;
106 em->len = (u64)-1;
107 em->block_len = (u64)-1;
108 em->block_start = 0;
109 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
110
111 spin_lock(&em_tree->lock);
112 ret = add_extent_mapping(em_tree, em);
113 if (ret == -EEXIST) {
114 u64 failed_start = em->start;
115 u64 failed_len = em->len;
116
117 free_extent_map(em);
118 em = lookup_extent_mapping(em_tree, start, len);
119 if (em) {
120 ret = 0;
121 } else {
122 em = lookup_extent_mapping(em_tree, failed_start,
123 failed_len);
124 ret = -EIO;
125 }
126 } else if (ret) {
127 free_extent_map(em);
128 em = NULL;
129 }
130 spin_unlock(&em_tree->lock);
131
132 if (ret)
133 em = ERR_PTR(ret);
134out:
135 return em;
136}
137
138u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
139{
140 return btrfs_crc32c(seed, data, len);
141}
142
143void btrfs_csum_final(u32 crc, char *result)
144{
145 *(__le32 *)result = ~cpu_to_le32(crc);
146}
147
148/*
149 * compute the csum for a btree block, and either verify it or write it
150 * into the csum field of the block.
151 */
152static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
153 int verify)
154{
155 u16 csum_size =
156 btrfs_super_csum_size(&root->fs_info->super_copy);
157 char *result = NULL;
158 unsigned long len;
159 unsigned long cur_len;
160 unsigned long offset = BTRFS_CSUM_SIZE;
161 char *map_token = NULL;
162 char *kaddr;
163 unsigned long map_start;
164 unsigned long map_len;
165 int err;
166 u32 crc = ~(u32)0;
167 unsigned long inline_result;
168
169 len = buf->len - offset;
170 while (len > 0) {
171 err = map_private_extent_buffer(buf, offset, 32,
172 &map_token, &kaddr,
173 &map_start, &map_len, KM_USER0);
174 if (err)
175 return 1;
176 cur_len = min(len, map_len - (offset - map_start));
177 crc = btrfs_csum_data(root, kaddr + offset - map_start,
178 crc, cur_len);
179 len -= cur_len;
180 offset += cur_len;
181 unmap_extent_buffer(buf, map_token, KM_USER0);
182 }
183 if (csum_size > sizeof(inline_result)) {
184 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
185 if (!result)
186 return 1;
187 } else {
188 result = (char *)&inline_result;
189 }
190
191 btrfs_csum_final(crc, result);
192
193 if (verify) {
194 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
195 u32 val;
196 u32 found = 0;
197 memcpy(&found, result, csum_size);
198
199 read_extent_buffer(buf, &val, 0, csum_size);
200 printk(KERN_INFO "btrfs: %s checksum verify failed "
201 "on %llu wanted %X found %X level %d\n",
202 root->fs_info->sb->s_id,
203 buf->start, val, found, btrfs_header_level(buf));
204 if (result != (char *)&inline_result)
205 kfree(result);
206 return 1;
207 }
208 } else {
209 write_extent_buffer(buf, result, 0, csum_size);
210 }
211 if (result != (char *)&inline_result)
212 kfree(result);
213 return 0;
214}
215
216/*
217 * we can't consider a given block up to date unless the transid of the
218 * block matches the transid in the parent node's pointer. This is how we
219 * detect blocks that either didn't get written at all or got written
220 * in the wrong place.
221 */
222static int verify_parent_transid(struct extent_io_tree *io_tree,
223 struct extent_buffer *eb, u64 parent_transid)
224{
225 int ret;
226
227 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
228 return 0;
229
230 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
231 if (extent_buffer_uptodate(io_tree, eb) &&
232 btrfs_header_generation(eb) == parent_transid) {
233 ret = 0;
234 goto out;
235 }
236 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
237 (unsigned long long)eb->start,
238 (unsigned long long)parent_transid,
239 (unsigned long long)btrfs_header_generation(eb));
240 ret = 1;
241 clear_extent_buffer_uptodate(io_tree, eb);
242out:
243 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
244 GFP_NOFS);
245 return ret;
246}
247
248/*
249 * helper to read a given tree block, doing retries as required when
250 * the checksums don't match and we have alternate mirrors to try.
251 */
252static int btree_read_extent_buffer_pages(struct btrfs_root *root,
253 struct extent_buffer *eb,
254 u64 start, u64 parent_transid)
255{
256 struct extent_io_tree *io_tree;
257 int ret;
258 int num_copies = 0;
259 int mirror_num = 0;
260
261 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
262 while (1) {
263 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
264 btree_get_extent, mirror_num);
265 if (!ret &&
266 !verify_parent_transid(io_tree, eb, parent_transid))
267 return ret;
268
269 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
270 eb->start, eb->len);
271 if (num_copies == 1)
272 return ret;
273
274 mirror_num++;
275 if (mirror_num > num_copies)
276 return ret;
277 }
278 return -EIO;
279}
280
281/*
282 * checksum a dirty tree block before IO. This has extra checks to make sure
283 * we only fill in the checksum field in the first page of a multi-page block
284 */
285
286static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
287{
288 struct extent_io_tree *tree;
289 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
290 u64 found_start;
291 int found_level;
292 unsigned long len;
293 struct extent_buffer *eb;
294 int ret;
295
296 tree = &BTRFS_I(page->mapping->host)->io_tree;
297
298 if (page->private == EXTENT_PAGE_PRIVATE)
299 goto out;
300 if (!page->private)
301 goto out;
302 len = page->private >> 2;
303 WARN_ON(len == 0);
304
305 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
306 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
307 btrfs_header_generation(eb));
308 BUG_ON(ret);
309 found_start = btrfs_header_bytenr(eb);
310 if (found_start != start) {
311 WARN_ON(1);
312 goto err;
313 }
314 if (eb->first_page != page) {
315 WARN_ON(1);
316 goto err;
317 }
318 if (!PageUptodate(page)) {
319 WARN_ON(1);
320 goto err;
321 }
322 found_level = btrfs_header_level(eb);
323
324 csum_tree_block(root, eb, 0);
325err:
326 free_extent_buffer(eb);
327out:
328 return 0;
329}
330
331static int check_tree_block_fsid(struct btrfs_root *root,
332 struct extent_buffer *eb)
333{
334 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
335 u8 fsid[BTRFS_UUID_SIZE];
336 int ret = 1;
337
338 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
339 BTRFS_FSID_SIZE);
340 while (fs_devices) {
341 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
342 ret = 0;
343 break;
344 }
345 fs_devices = fs_devices->seed;
346 }
347 return ret;
348}
349
350static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
351 struct extent_state *state)
352{
353 struct extent_io_tree *tree;
354 u64 found_start;
355 int found_level;
356 unsigned long len;
357 struct extent_buffer *eb;
358 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
359 int ret = 0;
360
361 tree = &BTRFS_I(page->mapping->host)->io_tree;
362 if (page->private == EXTENT_PAGE_PRIVATE)
363 goto out;
364 if (!page->private)
365 goto out;
366
367 len = page->private >> 2;
368 WARN_ON(len == 0);
369
370 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
371
372 found_start = btrfs_header_bytenr(eb);
373 if (found_start != start) {
374 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n",
375 (unsigned long long)found_start,
376 (unsigned long long)eb->start);
377 ret = -EIO;
378 goto err;
379 }
380 if (eb->first_page != page) {
381 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
382 eb->first_page->index, page->index);
383 WARN_ON(1);
384 ret = -EIO;
385 goto err;
386 }
387 if (check_tree_block_fsid(root, eb)) {
388 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
389 (unsigned long long)eb->start);
390 ret = -EIO;
391 goto err;
392 }
393 found_level = btrfs_header_level(eb);
394
395 ret = csum_tree_block(root, eb, 1);
396 if (ret)
397 ret = -EIO;
398
399 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
400 end = eb->start + end - 1;
401err:
402 free_extent_buffer(eb);
403out:
404 return ret;
405}
406
407static void end_workqueue_bio(struct bio *bio, int err)
408{
409 struct end_io_wq *end_io_wq = bio->bi_private;
410 struct btrfs_fs_info *fs_info;
411
412 fs_info = end_io_wq->info;
413 end_io_wq->error = err;
414 end_io_wq->work.func = end_workqueue_fn;
415 end_io_wq->work.flags = 0;
416
417 if (bio->bi_rw & (1 << BIO_RW)) {
418 if (end_io_wq->metadata)
419 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
420 &end_io_wq->work);
421 else
422 btrfs_queue_worker(&fs_info->endio_write_workers,
423 &end_io_wq->work);
424 } else {
425 if (end_io_wq->metadata)
426 btrfs_queue_worker(&fs_info->endio_meta_workers,
427 &end_io_wq->work);
428 else
429 btrfs_queue_worker(&fs_info->endio_workers,
430 &end_io_wq->work);
431 }
432}
433
434int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
435 int metadata)
436{
437 struct end_io_wq *end_io_wq;
438 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
439 if (!end_io_wq)
440 return -ENOMEM;
441
442 end_io_wq->private = bio->bi_private;
443 end_io_wq->end_io = bio->bi_end_io;
444 end_io_wq->info = info;
445 end_io_wq->error = 0;
446 end_io_wq->bio = bio;
447 end_io_wq->metadata = metadata;
448
449 bio->bi_private = end_io_wq;
450 bio->bi_end_io = end_workqueue_bio;
451 return 0;
452}
453
454unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
455{
456 unsigned long limit = min_t(unsigned long,
457 info->workers.max_workers,
458 info->fs_devices->open_devices);
459 return 256 * limit;
460}
461
462int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
463{
464 return atomic_read(&info->nr_async_bios) >
465 btrfs_async_submit_limit(info);
466}
467
468static void run_one_async_start(struct btrfs_work *work)
469{
470 struct btrfs_fs_info *fs_info;
471 struct async_submit_bio *async;
472
473 async = container_of(work, struct async_submit_bio, work);
474 fs_info = BTRFS_I(async->inode)->root->fs_info;
475 async->submit_bio_start(async->inode, async->rw, async->bio,
476 async->mirror_num, async->bio_flags);
477}
478
479static void run_one_async_done(struct btrfs_work *work)
480{
481 struct btrfs_fs_info *fs_info;
482 struct async_submit_bio *async;
483 int limit;
484
485 async = container_of(work, struct async_submit_bio, work);
486 fs_info = BTRFS_I(async->inode)->root->fs_info;
487
488 limit = btrfs_async_submit_limit(fs_info);
489 limit = limit * 2 / 3;
490
491 atomic_dec(&fs_info->nr_async_submits);
492
493 if (atomic_read(&fs_info->nr_async_submits) < limit &&
494 waitqueue_active(&fs_info->async_submit_wait))
495 wake_up(&fs_info->async_submit_wait);
496
497 async->submit_bio_done(async->inode, async->rw, async->bio,
498 async->mirror_num, async->bio_flags);
499}
500
501static void run_one_async_free(struct btrfs_work *work)
502{
503 struct async_submit_bio *async;
504
505 async = container_of(work, struct async_submit_bio, work);
506 kfree(async);
507}
508
509int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
510 int rw, struct bio *bio, int mirror_num,
511 unsigned long bio_flags,
512 extent_submit_bio_hook_t *submit_bio_start,
513 extent_submit_bio_hook_t *submit_bio_done)
514{
515 struct async_submit_bio *async;
516
517 async = kmalloc(sizeof(*async), GFP_NOFS);
518 if (!async)
519 return -ENOMEM;
520
521 async->inode = inode;
522 async->rw = rw;
523 async->bio = bio;
524 async->mirror_num = mirror_num;
525 async->submit_bio_start = submit_bio_start;
526 async->submit_bio_done = submit_bio_done;
527
528 async->work.func = run_one_async_start;
529 async->work.ordered_func = run_one_async_done;
530 async->work.ordered_free = run_one_async_free;
531
532 async->work.flags = 0;
533 async->bio_flags = bio_flags;
534
535 atomic_inc(&fs_info->nr_async_submits);
536 btrfs_queue_worker(&fs_info->workers, &async->work);
537#if 0
538 int limit = btrfs_async_submit_limit(fs_info);
539 if (atomic_read(&fs_info->nr_async_submits) > limit) {
540 wait_event_timeout(fs_info->async_submit_wait,
541 (atomic_read(&fs_info->nr_async_submits) < limit),
542 HZ/10);
543
544 wait_event_timeout(fs_info->async_submit_wait,
545 (atomic_read(&fs_info->nr_async_bios) < limit),
546 HZ/10);
547 }
548#endif
549 while (atomic_read(&fs_info->async_submit_draining) &&
550 atomic_read(&fs_info->nr_async_submits)) {
551 wait_event(fs_info->async_submit_wait,
552 (atomic_read(&fs_info->nr_async_submits) == 0));
553 }
554
555 return 0;
556}
557
558static int btree_csum_one_bio(struct bio *bio)
559{
560 struct bio_vec *bvec = bio->bi_io_vec;
561 int bio_index = 0;
562 struct btrfs_root *root;
563
564 WARN_ON(bio->bi_vcnt <= 0);
565 while (bio_index < bio->bi_vcnt) {
566 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
567 csum_dirty_buffer(root, bvec->bv_page);
568 bio_index++;
569 bvec++;
570 }
571 return 0;
572}
573
574static int __btree_submit_bio_start(struct inode *inode, int rw,
575 struct bio *bio, int mirror_num,
576 unsigned long bio_flags)
577{
578 /*
579 * when we're called for a write, we're already in the async
580 * submission context. Just jump into btrfs_map_bio
581 */
582 btree_csum_one_bio(bio);
583 return 0;
584}
585
586static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
587 int mirror_num, unsigned long bio_flags)
588{
589 /*
590 * when we're called for a write, we're already in the async
591 * submission context. Just jump into btrfs_map_bio
592 */
593 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
594}
595
596static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
597 int mirror_num, unsigned long bio_flags)
598{
599 int ret;
600
601 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
602 bio, 1);
603 BUG_ON(ret);
604
605 if (!(rw & (1 << BIO_RW))) {
606 /*
607 * called for a read, do the setup so that checksum validation
608 * can happen in the async kernel threads
609 */
610 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
611 mirror_num, 0);
612 }
613 /*
614 * kthread helpers are used to submit writes so that checksumming
615 * can happen in parallel across all CPUs
616 */
617 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
618 inode, rw, bio, mirror_num, 0,
619 __btree_submit_bio_start,
620 __btree_submit_bio_done);
621}
622
623static int btree_writepage(struct page *page, struct writeback_control *wbc)
624{
625 struct extent_io_tree *tree;
626 tree = &BTRFS_I(page->mapping->host)->io_tree;
627
628 if (current->flags & PF_MEMALLOC) {
629 redirty_page_for_writepage(wbc, page);
630 unlock_page(page);
631 return 0;
632 }
633 return extent_write_full_page(tree, page, btree_get_extent, wbc);
634}
635
636static int btree_writepages(struct address_space *mapping,
637 struct writeback_control *wbc)
638{
639 struct extent_io_tree *tree;
640 tree = &BTRFS_I(mapping->host)->io_tree;
641 if (wbc->sync_mode == WB_SYNC_NONE) {
642 u64 num_dirty;
643 u64 start = 0;
644 unsigned long thresh = 32 * 1024 * 1024;
645
646 if (wbc->for_kupdate)
647 return 0;
648
649 num_dirty = count_range_bits(tree, &start, (u64)-1,
650 thresh, EXTENT_DIRTY);
651 if (num_dirty < thresh)
652 return 0;
653 }
654 return extent_writepages(tree, mapping, btree_get_extent, wbc);
655}
656
657static int btree_readpage(struct file *file, struct page *page)
658{
659 struct extent_io_tree *tree;
660 tree = &BTRFS_I(page->mapping->host)->io_tree;
661 return extent_read_full_page(tree, page, btree_get_extent);
662}
663
664static int btree_releasepage(struct page *page, gfp_t gfp_flags)
665{
666 struct extent_io_tree *tree;
667 struct extent_map_tree *map;
668 int ret;
669
670 if (PageWriteback(page) || PageDirty(page))
671 return 0;
672
673 tree = &BTRFS_I(page->mapping->host)->io_tree;
674 map = &BTRFS_I(page->mapping->host)->extent_tree;
675
676 ret = try_release_extent_state(map, tree, page, gfp_flags);
677 if (!ret)
678 return 0;
679
680 ret = try_release_extent_buffer(tree, page);
681 if (ret == 1) {
682 ClearPagePrivate(page);
683 set_page_private(page, 0);
684 page_cache_release(page);
685 }
686
687 return ret;
688}
689
690static void btree_invalidatepage(struct page *page, unsigned long offset)
691{
692 struct extent_io_tree *tree;
693 tree = &BTRFS_I(page->mapping->host)->io_tree;
694 extent_invalidatepage(tree, page, offset);
695 btree_releasepage(page, GFP_NOFS);
696 if (PagePrivate(page)) {
697 printk(KERN_WARNING "btrfs warning page private not zero "
698 "on page %llu\n", (unsigned long long)page_offset(page));
699 ClearPagePrivate(page);
700 set_page_private(page, 0);
701 page_cache_release(page);
702 }
703}
704
705#if 0
706static int btree_writepage(struct page *page, struct writeback_control *wbc)
707{
708 struct buffer_head *bh;
709 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
710 struct buffer_head *head;
711 if (!page_has_buffers(page)) {
712 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
713 (1 << BH_Dirty)|(1 << BH_Uptodate));
714 }
715 head = page_buffers(page);
716 bh = head;
717 do {
718 if (buffer_dirty(bh))
719 csum_tree_block(root, bh, 0);
720 bh = bh->b_this_page;
721 } while (bh != head);
722 return block_write_full_page(page, btree_get_block, wbc);
723}
724#endif
725
726static struct address_space_operations btree_aops = {
727 .readpage = btree_readpage,
728 .writepage = btree_writepage,
729 .writepages = btree_writepages,
730 .releasepage = btree_releasepage,
731 .invalidatepage = btree_invalidatepage,
732 .sync_page = block_sync_page,
733};
734
735int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
736 u64 parent_transid)
737{
738 struct extent_buffer *buf = NULL;
739 struct inode *btree_inode = root->fs_info->btree_inode;
740 int ret = 0;
741
742 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
743 if (!buf)
744 return 0;
745 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
746 buf, 0, 0, btree_get_extent, 0);
747 free_extent_buffer(buf);
748 return ret;
749}
750
751struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
752 u64 bytenr, u32 blocksize)
753{
754 struct inode *btree_inode = root->fs_info->btree_inode;
755 struct extent_buffer *eb;
756 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
757 bytenr, blocksize, GFP_NOFS);
758 return eb;
759}
760
761struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
762 u64 bytenr, u32 blocksize)
763{
764 struct inode *btree_inode = root->fs_info->btree_inode;
765 struct extent_buffer *eb;
766
767 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
768 bytenr, blocksize, NULL, GFP_NOFS);
769 return eb;
770}
771
772
773int btrfs_write_tree_block(struct extent_buffer *buf)
774{
775 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
776 buf->start + buf->len - 1, WB_SYNC_ALL);
777}
778
779int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
780{
781 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
782 buf->start, buf->start + buf->len - 1);
783}
784
785struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
786 u32 blocksize, u64 parent_transid)
787{
788 struct extent_buffer *buf = NULL;
789 struct inode *btree_inode = root->fs_info->btree_inode;
790 struct extent_io_tree *io_tree;
791 int ret;
792
793 io_tree = &BTRFS_I(btree_inode)->io_tree;
794
795 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
796 if (!buf)
797 return NULL;
798
799 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
800
801 if (ret == 0)
802 buf->flags |= EXTENT_UPTODATE;
803 else
804 WARN_ON(1);
805 return buf;
806
807}
808
809int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
810 struct extent_buffer *buf)
811{
812 struct inode *btree_inode = root->fs_info->btree_inode;
813 if (btrfs_header_generation(buf) ==
814 root->fs_info->running_transaction->transid) {
815 WARN_ON(!btrfs_tree_locked(buf));
816 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
817 buf);
818 }
819 return 0;
820}
821
822static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
823 u32 stripesize, struct btrfs_root *root,
824 struct btrfs_fs_info *fs_info,
825 u64 objectid)
826{
827 root->node = NULL;
828 root->commit_root = NULL;
829 root->ref_tree = NULL;
830 root->sectorsize = sectorsize;
831 root->nodesize = nodesize;
832 root->leafsize = leafsize;
833 root->stripesize = stripesize;
834 root->ref_cows = 0;
835 root->track_dirty = 0;
836
837 root->fs_info = fs_info;
838 root->objectid = objectid;
839 root->last_trans = 0;
840 root->highest_inode = 0;
841 root->last_inode_alloc = 0;
842 root->name = NULL;
843 root->in_sysfs = 0;
844
845 INIT_LIST_HEAD(&root->dirty_list);
846 INIT_LIST_HEAD(&root->orphan_list);
847 INIT_LIST_HEAD(&root->dead_list);
848 spin_lock_init(&root->node_lock);
849 spin_lock_init(&root->list_lock);
850 mutex_init(&root->objectid_mutex);
851 mutex_init(&root->log_mutex);
852 init_waitqueue_head(&root->log_writer_wait);
853 init_waitqueue_head(&root->log_commit_wait[0]);
854 init_waitqueue_head(&root->log_commit_wait[1]);
855 atomic_set(&root->log_commit[0], 0);
856 atomic_set(&root->log_commit[1], 0);
857 atomic_set(&root->log_writers, 0);
858 root->log_batch = 0;
859 root->log_transid = 0;
860 extent_io_tree_init(&root->dirty_log_pages,
861 fs_info->btree_inode->i_mapping, GFP_NOFS);
862
863 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
864 root->ref_tree = &root->ref_tree_struct;
865
866 memset(&root->root_key, 0, sizeof(root->root_key));
867 memset(&root->root_item, 0, sizeof(root->root_item));
868 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
869 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
870 root->defrag_trans_start = fs_info->generation;
871 init_completion(&root->kobj_unregister);
872 root->defrag_running = 0;
873 root->defrag_level = 0;
874 root->root_key.objectid = objectid;
875 root->anon_super.s_root = NULL;
876 root->anon_super.s_dev = 0;
877 INIT_LIST_HEAD(&root->anon_super.s_list);
878 INIT_LIST_HEAD(&root->anon_super.s_instances);
879 init_rwsem(&root->anon_super.s_umount);
880
881 return 0;
882}
883
884static int find_and_setup_root(struct btrfs_root *tree_root,
885 struct btrfs_fs_info *fs_info,
886 u64 objectid,
887 struct btrfs_root *root)
888{
889 int ret;
890 u32 blocksize;
891 u64 generation;
892
893 __setup_root(tree_root->nodesize, tree_root->leafsize,
894 tree_root->sectorsize, tree_root->stripesize,
895 root, fs_info, objectid);
896 ret = btrfs_find_last_root(tree_root, objectid,
897 &root->root_item, &root->root_key);
898 BUG_ON(ret);
899
900 generation = btrfs_root_generation(&root->root_item);
901 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
902 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
903 blocksize, generation);
904 BUG_ON(!root->node);
905 return 0;
906}
907
908int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
909 struct btrfs_fs_info *fs_info)
910{
911 struct extent_buffer *eb;
912 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
913 u64 start = 0;
914 u64 end = 0;
915 int ret;
916
917 if (!log_root_tree)
918 return 0;
919
920 while (1) {
921 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
922 0, &start, &end, EXTENT_DIRTY);
923 if (ret)
924 break;
925
926 clear_extent_dirty(&log_root_tree->dirty_log_pages,
927 start, end, GFP_NOFS);
928 }
929 eb = fs_info->log_root_tree->node;
930
931 WARN_ON(btrfs_header_level(eb) != 0);
932 WARN_ON(btrfs_header_nritems(eb) != 0);
933
934 ret = btrfs_free_reserved_extent(fs_info->tree_root,
935 eb->start, eb->len);
936 BUG_ON(ret);
937
938 free_extent_buffer(eb);
939 kfree(fs_info->log_root_tree);
940 fs_info->log_root_tree = NULL;
941 return 0;
942}
943
944static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
945 struct btrfs_fs_info *fs_info)
946{
947 struct btrfs_root *root;
948 struct btrfs_root *tree_root = fs_info->tree_root;
949 struct extent_buffer *leaf;
950
951 root = kzalloc(sizeof(*root), GFP_NOFS);
952 if (!root)
953 return ERR_PTR(-ENOMEM);
954
955 __setup_root(tree_root->nodesize, tree_root->leafsize,
956 tree_root->sectorsize, tree_root->stripesize,
957 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
958
959 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
960 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
961 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
962 /*
963 * log trees do not get reference counted because they go away
964 * before a real commit is actually done. They do store pointers
965 * to file data extents, and those reference counts still get
966 * updated (along with back refs to the log tree).
967 */
968 root->ref_cows = 0;
969
970 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
971 0, BTRFS_TREE_LOG_OBJECTID,
972 trans->transid, 0, 0, 0);
973 if (IS_ERR(leaf)) {
974 kfree(root);
975 return ERR_CAST(leaf);
976 }
977
978 root->node = leaf;
979 btrfs_set_header_nritems(root->node, 0);
980 btrfs_set_header_level(root->node, 0);
981 btrfs_set_header_bytenr(root->node, root->node->start);
982 btrfs_set_header_generation(root->node, trans->transid);
983 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
984
985 write_extent_buffer(root->node, root->fs_info->fsid,
986 (unsigned long)btrfs_header_fsid(root->node),
987 BTRFS_FSID_SIZE);
988 btrfs_mark_buffer_dirty(root->node);
989 btrfs_tree_unlock(root->node);
990 return root;
991}
992
993int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
994 struct btrfs_fs_info *fs_info)
995{
996 struct btrfs_root *log_root;
997
998 log_root = alloc_log_tree(trans, fs_info);
999 if (IS_ERR(log_root))
1000 return PTR_ERR(log_root);
1001 WARN_ON(fs_info->log_root_tree);
1002 fs_info->log_root_tree = log_root;
1003 return 0;
1004}
1005
1006int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1007 struct btrfs_root *root)
1008{
1009 struct btrfs_root *log_root;
1010 struct btrfs_inode_item *inode_item;
1011
1012 log_root = alloc_log_tree(trans, root->fs_info);
1013 if (IS_ERR(log_root))
1014 return PTR_ERR(log_root);
1015
1016 log_root->last_trans = trans->transid;
1017 log_root->root_key.offset = root->root_key.objectid;
1018
1019 inode_item = &log_root->root_item.inode;
1020 inode_item->generation = cpu_to_le64(1);
1021 inode_item->size = cpu_to_le64(3);
1022 inode_item->nlink = cpu_to_le32(1);
1023 inode_item->nbytes = cpu_to_le64(root->leafsize);
1024 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1025
1026 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1027 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1028
1029 WARN_ON(root->log_root);
1030 root->log_root = log_root;
1031 root->log_transid = 0;
1032 return 0;
1033}
1034
1035struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1036 struct btrfs_key *location)
1037{
1038 struct btrfs_root *root;
1039 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1040 struct btrfs_path *path;
1041 struct extent_buffer *l;
1042 u64 highest_inode;
1043 u64 generation;
1044 u32 blocksize;
1045 int ret = 0;
1046
1047 root = kzalloc(sizeof(*root), GFP_NOFS);
1048 if (!root)
1049 return ERR_PTR(-ENOMEM);
1050 if (location->offset == (u64)-1) {
1051 ret = find_and_setup_root(tree_root, fs_info,
1052 location->objectid, root);
1053 if (ret) {
1054 kfree(root);
1055 return ERR_PTR(ret);
1056 }
1057 goto insert;
1058 }
1059
1060 __setup_root(tree_root->nodesize, tree_root->leafsize,
1061 tree_root->sectorsize, tree_root->stripesize,
1062 root, fs_info, location->objectid);
1063
1064 path = btrfs_alloc_path();
1065 BUG_ON(!path);
1066 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1067 if (ret != 0) {
1068 if (ret > 0)
1069 ret = -ENOENT;
1070 goto out;
1071 }
1072 l = path->nodes[0];
1073 read_extent_buffer(l, &root->root_item,
1074 btrfs_item_ptr_offset(l, path->slots[0]),
1075 sizeof(root->root_item));
1076 memcpy(&root->root_key, location, sizeof(*location));
1077 ret = 0;
1078out:
1079 btrfs_release_path(root, path);
1080 btrfs_free_path(path);
1081 if (ret) {
1082 kfree(root);
1083 return ERR_PTR(ret);
1084 }
1085 generation = btrfs_root_generation(&root->root_item);
1086 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1087 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1088 blocksize, generation);
1089 BUG_ON(!root->node);
1090insert:
1091 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1092 root->ref_cows = 1;
1093 ret = btrfs_find_highest_inode(root, &highest_inode);
1094 if (ret == 0) {
1095 root->highest_inode = highest_inode;
1096 root->last_inode_alloc = highest_inode;
1097 }
1098 }
1099 return root;
1100}
1101
1102struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1103 u64 root_objectid)
1104{
1105 struct btrfs_root *root;
1106
1107 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1108 return fs_info->tree_root;
1109 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1110 return fs_info->extent_root;
1111
1112 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1113 (unsigned long)root_objectid);
1114 return root;
1115}
1116
1117struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1118 struct btrfs_key *location)
1119{
1120 struct btrfs_root *root;
1121 int ret;
1122
1123 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1124 return fs_info->tree_root;
1125 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1126 return fs_info->extent_root;
1127 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1128 return fs_info->chunk_root;
1129 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1130 return fs_info->dev_root;
1131 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1132 return fs_info->csum_root;
1133
1134 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1135 (unsigned long)location->objectid);
1136 if (root)
1137 return root;
1138
1139 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1140 if (IS_ERR(root))
1141 return root;
1142
1143 set_anon_super(&root->anon_super, NULL);
1144
1145 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1146 (unsigned long)root->root_key.objectid,
1147 root);
1148 if (ret) {
1149 free_extent_buffer(root->node);
1150 kfree(root);
1151 return ERR_PTR(ret);
1152 }
1153 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1154 ret = btrfs_find_dead_roots(fs_info->tree_root,
1155 root->root_key.objectid, root);
1156 BUG_ON(ret);
1157 btrfs_orphan_cleanup(root);
1158 }
1159 return root;
1160}
1161
1162struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1163 struct btrfs_key *location,
1164 const char *name, int namelen)
1165{
1166 struct btrfs_root *root;
1167 int ret;
1168
1169 root = btrfs_read_fs_root_no_name(fs_info, location);
1170 if (!root)
1171 return NULL;
1172
1173 if (root->in_sysfs)
1174 return root;
1175
1176 ret = btrfs_set_root_name(root, name, namelen);
1177 if (ret) {
1178 free_extent_buffer(root->node);
1179 kfree(root);
1180 return ERR_PTR(ret);
1181 }
1182#if 0
1183 ret = btrfs_sysfs_add_root(root);
1184 if (ret) {
1185 free_extent_buffer(root->node);
1186 kfree(root->name);
1187 kfree(root);
1188 return ERR_PTR(ret);
1189 }
1190#endif
1191 root->in_sysfs = 1;
1192 return root;
1193}
1194
1195static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1196{
1197 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1198 int ret = 0;
1199 struct btrfs_device *device;
1200 struct backing_dev_info *bdi;
1201#if 0
1202 if ((bdi_bits & (1 << BDI_write_congested)) &&
1203 btrfs_congested_async(info, 0))
1204 return 1;
1205#endif
1206 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1207 if (!device->bdev)
1208 continue;
1209 bdi = blk_get_backing_dev_info(device->bdev);
1210 if (bdi && bdi_congested(bdi, bdi_bits)) {
1211 ret = 1;
1212 break;
1213 }
1214 }
1215 return ret;
1216}
1217
1218/*
1219 * this unplugs every device on the box, and it is only used when page
1220 * is null
1221 */
1222static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1223{
1224 struct btrfs_device *device;
1225 struct btrfs_fs_info *info;
1226
1227 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1228 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1229 if (!device->bdev)
1230 continue;
1231
1232 bdi = blk_get_backing_dev_info(device->bdev);
1233 if (bdi->unplug_io_fn)
1234 bdi->unplug_io_fn(bdi, page);
1235 }
1236}
1237
1238static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1239{
1240 struct inode *inode;
1241 struct extent_map_tree *em_tree;
1242 struct extent_map *em;
1243 struct address_space *mapping;
1244 u64 offset;
1245
1246 /* the generic O_DIRECT read code does this */
1247 if (1 || !page) {
1248 __unplug_io_fn(bdi, page);
1249 return;
1250 }
1251
1252 /*
1253 * page->mapping may change at any time. Get a consistent copy
1254 * and use that for everything below
1255 */
1256 smp_mb();
1257 mapping = page->mapping;
1258 if (!mapping)
1259 return;
1260
1261 inode = mapping->host;
1262
1263 /*
1264 * don't do the expensive searching for a small number of
1265 * devices
1266 */
1267 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1268 __unplug_io_fn(bdi, page);
1269 return;
1270 }
1271
1272 offset = page_offset(page);
1273
1274 em_tree = &BTRFS_I(inode)->extent_tree;
1275 spin_lock(&em_tree->lock);
1276 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1277 spin_unlock(&em_tree->lock);
1278 if (!em) {
1279 __unplug_io_fn(bdi, page);
1280 return;
1281 }
1282
1283 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1284 free_extent_map(em);
1285 __unplug_io_fn(bdi, page);
1286 return;
1287 }
1288 offset = offset - em->start;
1289 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1290 em->block_start + offset, page);
1291 free_extent_map(em);
1292}
1293
1294static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1295{
1296 bdi_init(bdi);
1297 bdi->ra_pages = default_backing_dev_info.ra_pages;
1298 bdi->state = 0;
1299 bdi->capabilities = default_backing_dev_info.capabilities;
1300 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1301 bdi->unplug_io_data = info;
1302 bdi->congested_fn = btrfs_congested_fn;
1303 bdi->congested_data = info;
1304 return 0;
1305}
1306
1307static int bio_ready_for_csum(struct bio *bio)
1308{
1309 u64 length = 0;
1310 u64 buf_len = 0;
1311 u64 start = 0;
1312 struct page *page;
1313 struct extent_io_tree *io_tree = NULL;
1314 struct btrfs_fs_info *info = NULL;
1315 struct bio_vec *bvec;
1316 int i;
1317 int ret;
1318
1319 bio_for_each_segment(bvec, bio, i) {
1320 page = bvec->bv_page;
1321 if (page->private == EXTENT_PAGE_PRIVATE) {
1322 length += bvec->bv_len;
1323 continue;
1324 }
1325 if (!page->private) {
1326 length += bvec->bv_len;
1327 continue;
1328 }
1329 length = bvec->bv_len;
1330 buf_len = page->private >> 2;
1331 start = page_offset(page) + bvec->bv_offset;
1332 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1333 info = BTRFS_I(page->mapping->host)->root->fs_info;
1334 }
1335 /* are we fully contained in this bio? */
1336 if (buf_len <= length)
1337 return 1;
1338
1339 ret = extent_range_uptodate(io_tree, start + length,
1340 start + buf_len - 1);
1341 if (ret == 1)
1342 return ret;
1343 return ret;
1344}
1345
1346/*
1347 * called by the kthread helper functions to finally call the bio end_io
1348 * functions. This is where read checksum verification actually happens
1349 */
1350static void end_workqueue_fn(struct btrfs_work *work)
1351{
1352 struct bio *bio;
1353 struct end_io_wq *end_io_wq;
1354 struct btrfs_fs_info *fs_info;
1355 int error;
1356
1357 end_io_wq = container_of(work, struct end_io_wq, work);
1358 bio = end_io_wq->bio;
1359 fs_info = end_io_wq->info;
1360
1361 /* metadata bio reads are special because the whole tree block must
1362 * be checksummed at once. This makes sure the entire block is in
1363 * ram and up to date before trying to verify things. For
1364 * blocksize <= pagesize, it is basically a noop
1365 */
1366 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1367 !bio_ready_for_csum(bio)) {
1368 btrfs_queue_worker(&fs_info->endio_meta_workers,
1369 &end_io_wq->work);
1370 return;
1371 }
1372 error = end_io_wq->error;
1373 bio->bi_private = end_io_wq->private;
1374 bio->bi_end_io = end_io_wq->end_io;
1375 kfree(end_io_wq);
1376 bio_endio(bio, error);
1377}
1378
1379static int cleaner_kthread(void *arg)
1380{
1381 struct btrfs_root *root = arg;
1382
1383 do {
1384 smp_mb();
1385 if (root->fs_info->closing)
1386 break;
1387
1388 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1389 mutex_lock(&root->fs_info->cleaner_mutex);
1390 btrfs_clean_old_snapshots(root);
1391 mutex_unlock(&root->fs_info->cleaner_mutex);
1392
1393 if (freezing(current)) {
1394 refrigerator();
1395 } else {
1396 smp_mb();
1397 if (root->fs_info->closing)
1398 break;
1399 set_current_state(TASK_INTERRUPTIBLE);
1400 schedule();
1401 __set_current_state(TASK_RUNNING);
1402 }
1403 } while (!kthread_should_stop());
1404 return 0;
1405}
1406
1407static int transaction_kthread(void *arg)
1408{
1409 struct btrfs_root *root = arg;
1410 struct btrfs_trans_handle *trans;
1411 struct btrfs_transaction *cur;
1412 unsigned long now;
1413 unsigned long delay;
1414 int ret;
1415
1416 do {
1417 smp_mb();
1418 if (root->fs_info->closing)
1419 break;
1420
1421 delay = HZ * 30;
1422 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1423 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1424
1425 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1426 printk(KERN_INFO "btrfs: total reference cache "
1427 "size %llu\n",
1428 root->fs_info->total_ref_cache_size);
1429 }
1430
1431 mutex_lock(&root->fs_info->trans_mutex);
1432 cur = root->fs_info->running_transaction;
1433 if (!cur) {
1434 mutex_unlock(&root->fs_info->trans_mutex);
1435 goto sleep;
1436 }
1437
1438 now = get_seconds();
1439 if (now < cur->start_time || now - cur->start_time < 30) {
1440 mutex_unlock(&root->fs_info->trans_mutex);
1441 delay = HZ * 5;
1442 goto sleep;
1443 }
1444 mutex_unlock(&root->fs_info->trans_mutex);
1445 trans = btrfs_start_transaction(root, 1);
1446 ret = btrfs_commit_transaction(trans, root);
1447sleep:
1448 wake_up_process(root->fs_info->cleaner_kthread);
1449 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1450
1451 if (freezing(current)) {
1452 refrigerator();
1453 } else {
1454 if (root->fs_info->closing)
1455 break;
1456 set_current_state(TASK_INTERRUPTIBLE);
1457 schedule_timeout(delay);
1458 __set_current_state(TASK_RUNNING);
1459 }
1460 } while (!kthread_should_stop());
1461 return 0;
1462}
1463
1464struct btrfs_root *open_ctree(struct super_block *sb,
1465 struct btrfs_fs_devices *fs_devices,
1466 char *options)
1467{
1468 u32 sectorsize;
1469 u32 nodesize;
1470 u32 leafsize;
1471 u32 blocksize;
1472 u32 stripesize;
1473 u64 generation;
1474 u64 features;
1475 struct btrfs_key location;
1476 struct buffer_head *bh;
1477 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1478 GFP_NOFS);
1479 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1480 GFP_NOFS);
1481 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1482 GFP_NOFS);
1483 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1484 GFP_NOFS);
1485 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1486 GFP_NOFS);
1487 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1488 GFP_NOFS);
1489 struct btrfs_root *log_tree_root;
1490
1491 int ret;
1492 int err = -EINVAL;
1493
1494 struct btrfs_super_block *disk_super;
1495
1496 if (!extent_root || !tree_root || !fs_info ||
1497 !chunk_root || !dev_root || !csum_root) {
1498 err = -ENOMEM;
1499 goto fail;
1500 }
1501 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1502 INIT_LIST_HEAD(&fs_info->trans_list);
1503 INIT_LIST_HEAD(&fs_info->dead_roots);
1504 INIT_LIST_HEAD(&fs_info->hashers);
1505 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1506 spin_lock_init(&fs_info->delalloc_lock);
1507 spin_lock_init(&fs_info->new_trans_lock);
1508 spin_lock_init(&fs_info->ref_cache_lock);
1509
1510 init_completion(&fs_info->kobj_unregister);
1511 fs_info->tree_root = tree_root;
1512 fs_info->extent_root = extent_root;
1513 fs_info->csum_root = csum_root;
1514 fs_info->chunk_root = chunk_root;
1515 fs_info->dev_root = dev_root;
1516 fs_info->fs_devices = fs_devices;
1517 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1518 INIT_LIST_HEAD(&fs_info->space_info);
1519 btrfs_mapping_init(&fs_info->mapping_tree);
1520 atomic_set(&fs_info->nr_async_submits, 0);
1521 atomic_set(&fs_info->async_delalloc_pages, 0);
1522 atomic_set(&fs_info->async_submit_draining, 0);
1523 atomic_set(&fs_info->nr_async_bios, 0);
1524 atomic_set(&fs_info->throttles, 0);
1525 atomic_set(&fs_info->throttle_gen, 0);
1526 fs_info->sb = sb;
1527 fs_info->max_extent = (u64)-1;
1528 fs_info->max_inline = 8192 * 1024;
1529 setup_bdi(fs_info, &fs_info->bdi);
1530 fs_info->btree_inode = new_inode(sb);
1531 fs_info->btree_inode->i_ino = 1;
1532 fs_info->btree_inode->i_nlink = 1;
1533
1534 fs_info->thread_pool_size = min_t(unsigned long,
1535 num_online_cpus() + 2, 8);
1536
1537 INIT_LIST_HEAD(&fs_info->ordered_extents);
1538 spin_lock_init(&fs_info->ordered_extent_lock);
1539
1540 sb->s_blocksize = 4096;
1541 sb->s_blocksize_bits = blksize_bits(4096);
1542
1543 /*
1544 * we set the i_size on the btree inode to the max possible int.
1545 * the real end of the address space is determined by all of
1546 * the devices in the system
1547 */
1548 fs_info->btree_inode->i_size = OFFSET_MAX;
1549 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1550 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1551
1552 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1553 fs_info->btree_inode->i_mapping,
1554 GFP_NOFS);
1555 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1556 GFP_NOFS);
1557
1558 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1559
1560 spin_lock_init(&fs_info->block_group_cache_lock);
1561 fs_info->block_group_cache_tree.rb_node = NULL;
1562
1563 extent_io_tree_init(&fs_info->pinned_extents,
1564 fs_info->btree_inode->i_mapping, GFP_NOFS);
1565 extent_io_tree_init(&fs_info->pending_del,
1566 fs_info->btree_inode->i_mapping, GFP_NOFS);
1567 extent_io_tree_init(&fs_info->extent_ins,
1568 fs_info->btree_inode->i_mapping, GFP_NOFS);
1569 fs_info->do_barriers = 1;
1570
1571 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1572 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1573 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1574
1575 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1576 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1577 sizeof(struct btrfs_key));
1578 insert_inode_hash(fs_info->btree_inode);
1579
1580 mutex_init(&fs_info->trans_mutex);
1581 mutex_init(&fs_info->tree_log_mutex);
1582 mutex_init(&fs_info->drop_mutex);
1583 mutex_init(&fs_info->extent_ins_mutex);
1584 mutex_init(&fs_info->pinned_mutex);
1585 mutex_init(&fs_info->chunk_mutex);
1586 mutex_init(&fs_info->transaction_kthread_mutex);
1587 mutex_init(&fs_info->cleaner_mutex);
1588 mutex_init(&fs_info->volume_mutex);
1589 mutex_init(&fs_info->tree_reloc_mutex);
1590 init_waitqueue_head(&fs_info->transaction_throttle);
1591 init_waitqueue_head(&fs_info->transaction_wait);
1592 init_waitqueue_head(&fs_info->async_submit_wait);
1593
1594 __setup_root(4096, 4096, 4096, 4096, tree_root,
1595 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1596
1597
1598 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1599 if (!bh)
1600 goto fail_iput;
1601
1602 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1603 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1604 sizeof(fs_info->super_for_commit));
1605 brelse(bh);
1606
1607 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1608
1609 disk_super = &fs_info->super_copy;
1610 if (!btrfs_super_root(disk_super))
1611 goto fail_iput;
1612
1613 ret = btrfs_parse_options(tree_root, options);
1614 if (ret) {
1615 err = ret;
1616 goto fail_iput;
1617 }
1618
1619 features = btrfs_super_incompat_flags(disk_super) &
1620 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1621 if (features) {
1622 printk(KERN_ERR "BTRFS: couldn't mount because of "
1623 "unsupported optional features (%Lx).\n",
1624 features);
1625 err = -EINVAL;
1626 goto fail_iput;
1627 }
1628
1629 features = btrfs_super_compat_ro_flags(disk_super) &
1630 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1631 if (!(sb->s_flags & MS_RDONLY) && features) {
1632 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1633 "unsupported option features (%Lx).\n",
1634 features);
1635 err = -EINVAL;
1636 goto fail_iput;
1637 }
1638
1639 /*
1640 * we need to start all the end_io workers up front because the
1641 * queue work function gets called at interrupt time, and so it
1642 * cannot dynamically grow.
1643 */
1644 btrfs_init_workers(&fs_info->workers, "worker",
1645 fs_info->thread_pool_size);
1646
1647 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1648 fs_info->thread_pool_size);
1649
1650 btrfs_init_workers(&fs_info->submit_workers, "submit",
1651 min_t(u64, fs_devices->num_devices,
1652 fs_info->thread_pool_size));
1653
1654 /* a higher idle thresh on the submit workers makes it much more
1655 * likely that bios will be send down in a sane order to the
1656 * devices
1657 */
1658 fs_info->submit_workers.idle_thresh = 64;
1659
1660 fs_info->workers.idle_thresh = 16;
1661 fs_info->workers.ordered = 1;
1662
1663 fs_info->delalloc_workers.idle_thresh = 2;
1664 fs_info->delalloc_workers.ordered = 1;
1665
1666 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1667 btrfs_init_workers(&fs_info->endio_workers, "endio",
1668 fs_info->thread_pool_size);
1669 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1670 fs_info->thread_pool_size);
1671 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1672 "endio-meta-write", fs_info->thread_pool_size);
1673 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1674 fs_info->thread_pool_size);
1675
1676 /*
1677 * endios are largely parallel and should have a very
1678 * low idle thresh
1679 */
1680 fs_info->endio_workers.idle_thresh = 4;
1681 fs_info->endio_meta_workers.idle_thresh = 4;
1682
1683 fs_info->endio_write_workers.idle_thresh = 64;
1684 fs_info->endio_meta_write_workers.idle_thresh = 64;
1685
1686 btrfs_start_workers(&fs_info->workers, 1);
1687 btrfs_start_workers(&fs_info->submit_workers, 1);
1688 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1689 btrfs_start_workers(&fs_info->fixup_workers, 1);
1690 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1691 btrfs_start_workers(&fs_info->endio_meta_workers,
1692 fs_info->thread_pool_size);
1693 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1694 fs_info->thread_pool_size);
1695 btrfs_start_workers(&fs_info->endio_write_workers,
1696 fs_info->thread_pool_size);
1697
1698 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1699 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1700 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1701
1702 nodesize = btrfs_super_nodesize(disk_super);
1703 leafsize = btrfs_super_leafsize(disk_super);
1704 sectorsize = btrfs_super_sectorsize(disk_super);
1705 stripesize = btrfs_super_stripesize(disk_super);
1706 tree_root->nodesize = nodesize;
1707 tree_root->leafsize = leafsize;
1708 tree_root->sectorsize = sectorsize;
1709 tree_root->stripesize = stripesize;
1710
1711 sb->s_blocksize = sectorsize;
1712 sb->s_blocksize_bits = blksize_bits(sectorsize);
1713
1714 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1715 sizeof(disk_super->magic))) {
1716 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1717 goto fail_sb_buffer;
1718 }
1719
1720 mutex_lock(&fs_info->chunk_mutex);
1721 ret = btrfs_read_sys_array(tree_root);
1722 mutex_unlock(&fs_info->chunk_mutex);
1723 if (ret) {
1724 printk(KERN_WARNING "btrfs: failed to read the system "
1725 "array on %s\n", sb->s_id);
1726 goto fail_sys_array;
1727 }
1728
1729 blocksize = btrfs_level_size(tree_root,
1730 btrfs_super_chunk_root_level(disk_super));
1731 generation = btrfs_super_chunk_root_generation(disk_super);
1732
1733 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1734 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1735
1736 chunk_root->node = read_tree_block(chunk_root,
1737 btrfs_super_chunk_root(disk_super),
1738 blocksize, generation);
1739 BUG_ON(!chunk_root->node);
1740
1741 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1742 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1743 BTRFS_UUID_SIZE);
1744
1745 mutex_lock(&fs_info->chunk_mutex);
1746 ret = btrfs_read_chunk_tree(chunk_root);
1747 mutex_unlock(&fs_info->chunk_mutex);
1748 if (ret) {
1749 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1750 sb->s_id);
1751 goto fail_chunk_root;
1752 }
1753
1754 btrfs_close_extra_devices(fs_devices);
1755
1756 blocksize = btrfs_level_size(tree_root,
1757 btrfs_super_root_level(disk_super));
1758 generation = btrfs_super_generation(disk_super);
1759
1760 tree_root->node = read_tree_block(tree_root,
1761 btrfs_super_root(disk_super),
1762 blocksize, generation);
1763 if (!tree_root->node)
1764 goto fail_chunk_root;
1765
1766
1767 ret = find_and_setup_root(tree_root, fs_info,
1768 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1769 if (ret)
1770 goto fail_tree_root;
1771 extent_root->track_dirty = 1;
1772
1773 ret = find_and_setup_root(tree_root, fs_info,
1774 BTRFS_DEV_TREE_OBJECTID, dev_root);
1775 dev_root->track_dirty = 1;
1776
1777 if (ret)
1778 goto fail_extent_root;
1779
1780 ret = find_and_setup_root(tree_root, fs_info,
1781 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1782 if (ret)
1783 goto fail_extent_root;
1784
1785 csum_root->track_dirty = 1;
1786
1787 btrfs_read_block_groups(extent_root);
1788
1789 fs_info->generation = generation;
1790 fs_info->last_trans_committed = generation;
1791 fs_info->data_alloc_profile = (u64)-1;
1792 fs_info->metadata_alloc_profile = (u64)-1;
1793 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1794 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1795 "btrfs-cleaner");
1796 if (IS_ERR(fs_info->cleaner_kthread))
1797 goto fail_csum_root;
1798
1799 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1800 tree_root,
1801 "btrfs-transaction");
1802 if (IS_ERR(fs_info->transaction_kthread))
1803 goto fail_cleaner;
1804
1805 if (btrfs_super_log_root(disk_super) != 0) {
1806 u64 bytenr = btrfs_super_log_root(disk_super);
1807
1808 if (fs_devices->rw_devices == 0) {
1809 printk(KERN_WARNING "Btrfs log replay required "
1810 "on RO media\n");
1811 err = -EIO;
1812 goto fail_trans_kthread;
1813 }
1814 blocksize =
1815 btrfs_level_size(tree_root,
1816 btrfs_super_log_root_level(disk_super));
1817
1818 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1819 GFP_NOFS);
1820
1821 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1822 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1823
1824 log_tree_root->node = read_tree_block(tree_root, bytenr,
1825 blocksize,
1826 generation + 1);
1827 ret = btrfs_recover_log_trees(log_tree_root);
1828 BUG_ON(ret);
1829
1830 if (sb->s_flags & MS_RDONLY) {
1831 ret = btrfs_commit_super(tree_root);
1832 BUG_ON(ret);
1833 }
1834 }
1835
1836 if (!(sb->s_flags & MS_RDONLY)) {
1837 ret = btrfs_cleanup_reloc_trees(tree_root);
1838 BUG_ON(ret);
1839 }
1840
1841 location.objectid = BTRFS_FS_TREE_OBJECTID;
1842 location.type = BTRFS_ROOT_ITEM_KEY;
1843 location.offset = (u64)-1;
1844
1845 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1846 if (!fs_info->fs_root)
1847 goto fail_trans_kthread;
1848 return tree_root;
1849
1850fail_trans_kthread:
1851 kthread_stop(fs_info->transaction_kthread);
1852fail_cleaner:
1853 kthread_stop(fs_info->cleaner_kthread);
1854
1855 /*
1856 * make sure we're done with the btree inode before we stop our
1857 * kthreads
1858 */
1859 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1860 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1861
1862fail_csum_root:
1863 free_extent_buffer(csum_root->node);
1864fail_extent_root:
1865 free_extent_buffer(extent_root->node);
1866fail_tree_root:
1867 free_extent_buffer(tree_root->node);
1868fail_chunk_root:
1869 free_extent_buffer(chunk_root->node);
1870fail_sys_array:
1871 free_extent_buffer(dev_root->node);
1872fail_sb_buffer:
1873 btrfs_stop_workers(&fs_info->fixup_workers);
1874 btrfs_stop_workers(&fs_info->delalloc_workers);
1875 btrfs_stop_workers(&fs_info->workers);
1876 btrfs_stop_workers(&fs_info->endio_workers);
1877 btrfs_stop_workers(&fs_info->endio_meta_workers);
1878 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1879 btrfs_stop_workers(&fs_info->endio_write_workers);
1880 btrfs_stop_workers(&fs_info->submit_workers);
1881fail_iput:
1882 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1883 iput(fs_info->btree_inode);
1884
1885 btrfs_close_devices(fs_info->fs_devices);
1886 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1887 bdi_destroy(&fs_info->bdi);
1888
1889fail:
1890 kfree(extent_root);
1891 kfree(tree_root);
1892 kfree(fs_info);
1893 kfree(chunk_root);
1894 kfree(dev_root);
1895 kfree(csum_root);
1896 return ERR_PTR(err);
1897}
1898
1899static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1900{
1901 char b[BDEVNAME_SIZE];
1902
1903 if (uptodate) {
1904 set_buffer_uptodate(bh);
1905 } else {
1906 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1907 printk(KERN_WARNING "lost page write due to "
1908 "I/O error on %s\n",
1909 bdevname(bh->b_bdev, b));
1910 }
1911 /* note, we dont' set_buffer_write_io_error because we have
1912 * our own ways of dealing with the IO errors
1913 */
1914 clear_buffer_uptodate(bh);
1915 }
1916 unlock_buffer(bh);
1917 put_bh(bh);
1918}
1919
1920struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1921{
1922 struct buffer_head *bh;
1923 struct buffer_head *latest = NULL;
1924 struct btrfs_super_block *super;
1925 int i;
1926 u64 transid = 0;
1927 u64 bytenr;
1928
1929 /* we would like to check all the supers, but that would make
1930 * a btrfs mount succeed after a mkfs from a different FS.
1931 * So, we need to add a special mount option to scan for
1932 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1933 */
1934 for (i = 0; i < 1; i++) {
1935 bytenr = btrfs_sb_offset(i);
1936 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1937 break;
1938 bh = __bread(bdev, bytenr / 4096, 4096);
1939 if (!bh)
1940 continue;
1941
1942 super = (struct btrfs_super_block *)bh->b_data;
1943 if (btrfs_super_bytenr(super) != bytenr ||
1944 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1945 sizeof(super->magic))) {
1946 brelse(bh);
1947 continue;
1948 }
1949
1950 if (!latest || btrfs_super_generation(super) > transid) {
1951 brelse(latest);
1952 latest = bh;
1953 transid = btrfs_super_generation(super);
1954 } else {
1955 brelse(bh);
1956 }
1957 }
1958 return latest;
1959}
1960
1961static int write_dev_supers(struct btrfs_device *device,
1962 struct btrfs_super_block *sb,
1963 int do_barriers, int wait, int max_mirrors)
1964{
1965 struct buffer_head *bh;
1966 int i;
1967 int ret;
1968 int errors = 0;
1969 u32 crc;
1970 u64 bytenr;
1971 int last_barrier = 0;
1972
1973 if (max_mirrors == 0)
1974 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
1975
1976 /* make sure only the last submit_bh does a barrier */
1977 if (do_barriers) {
1978 for (i = 0; i < max_mirrors; i++) {
1979 bytenr = btrfs_sb_offset(i);
1980 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
1981 device->total_bytes)
1982 break;
1983 last_barrier = i;
1984 }
1985 }
1986
1987 for (i = 0; i < max_mirrors; i++) {
1988 bytenr = btrfs_sb_offset(i);
1989 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1990 break;
1991
1992 if (wait) {
1993 bh = __find_get_block(device->bdev, bytenr / 4096,
1994 BTRFS_SUPER_INFO_SIZE);
1995 BUG_ON(!bh);
1996 brelse(bh);
1997 wait_on_buffer(bh);
1998 if (buffer_uptodate(bh)) {
1999 brelse(bh);
2000 continue;
2001 }
2002 } else {
2003 btrfs_set_super_bytenr(sb, bytenr);
2004
2005 crc = ~(u32)0;
2006 crc = btrfs_csum_data(NULL, (char *)sb +
2007 BTRFS_CSUM_SIZE, crc,
2008 BTRFS_SUPER_INFO_SIZE -
2009 BTRFS_CSUM_SIZE);
2010 btrfs_csum_final(crc, sb->csum);
2011
2012 bh = __getblk(device->bdev, bytenr / 4096,
2013 BTRFS_SUPER_INFO_SIZE);
2014 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2015
2016 set_buffer_uptodate(bh);
2017 get_bh(bh);
2018 lock_buffer(bh);
2019 bh->b_end_io = btrfs_end_buffer_write_sync;
2020 }
2021
2022 if (i == last_barrier && do_barriers && device->barriers) {
2023 ret = submit_bh(WRITE_BARRIER, bh);
2024 if (ret == -EOPNOTSUPP) {
2025 printk("btrfs: disabling barriers on dev %s\n",
2026 device->name);
2027 set_buffer_uptodate(bh);
2028 device->barriers = 0;
2029 get_bh(bh);
2030 lock_buffer(bh);
2031 ret = submit_bh(WRITE, bh);
2032 }
2033 } else {
2034 ret = submit_bh(WRITE, bh);
2035 }
2036
2037 if (!ret && wait) {
2038 wait_on_buffer(bh);
2039 if (!buffer_uptodate(bh))
2040 errors++;
2041 } else if (ret) {
2042 errors++;
2043 }
2044 if (wait)
2045 brelse(bh);
2046 }
2047 return errors < i ? 0 : -1;
2048}
2049
2050int write_all_supers(struct btrfs_root *root, int max_mirrors)
2051{
2052 struct list_head *head = &root->fs_info->fs_devices->devices;
2053 struct btrfs_device *dev;
2054 struct btrfs_super_block *sb;
2055 struct btrfs_dev_item *dev_item;
2056 int ret;
2057 int do_barriers;
2058 int max_errors;
2059 int total_errors = 0;
2060 u64 flags;
2061
2062 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2063 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2064
2065 sb = &root->fs_info->super_for_commit;
2066 dev_item = &sb->dev_item;
2067 list_for_each_entry(dev, head, dev_list) {
2068 if (!dev->bdev) {
2069 total_errors++;
2070 continue;
2071 }
2072 if (!dev->in_fs_metadata || !dev->writeable)
2073 continue;
2074
2075 btrfs_set_stack_device_generation(dev_item, 0);
2076 btrfs_set_stack_device_type(dev_item, dev->type);
2077 btrfs_set_stack_device_id(dev_item, dev->devid);
2078 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2079 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2080 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2081 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2082 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2083 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2084 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2085
2086 flags = btrfs_super_flags(sb);
2087 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2088
2089 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2090 if (ret)
2091 total_errors++;
2092 }
2093 if (total_errors > max_errors) {
2094 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2095 total_errors);
2096 BUG();
2097 }
2098
2099 total_errors = 0;
2100 list_for_each_entry(dev, head, dev_list) {
2101 if (!dev->bdev)
2102 continue;
2103 if (!dev->in_fs_metadata || !dev->writeable)
2104 continue;
2105
2106 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2107 if (ret)
2108 total_errors++;
2109 }
2110 if (total_errors > max_errors) {
2111 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2112 total_errors);
2113 BUG();
2114 }
2115 return 0;
2116}
2117
2118int write_ctree_super(struct btrfs_trans_handle *trans,
2119 struct btrfs_root *root, int max_mirrors)
2120{
2121 int ret;
2122
2123 ret = write_all_supers(root, max_mirrors);
2124 return ret;
2125}
2126
2127int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2128{
2129 radix_tree_delete(&fs_info->fs_roots_radix,
2130 (unsigned long)root->root_key.objectid);
2131 if (root->anon_super.s_dev) {
2132 down_write(&root->anon_super.s_umount);
2133 kill_anon_super(&root->anon_super);
2134 }
2135 if (root->node)
2136 free_extent_buffer(root->node);
2137 if (root->commit_root)
2138 free_extent_buffer(root->commit_root);
2139 kfree(root->name);
2140 kfree(root);
2141 return 0;
2142}
2143
2144static int del_fs_roots(struct btrfs_fs_info *fs_info)
2145{
2146 int ret;
2147 struct btrfs_root *gang[8];
2148 int i;
2149
2150 while (1) {
2151 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2152 (void **)gang, 0,
2153 ARRAY_SIZE(gang));
2154 if (!ret)
2155 break;
2156 for (i = 0; i < ret; i++)
2157 btrfs_free_fs_root(fs_info, gang[i]);
2158 }
2159 return 0;
2160}
2161
2162int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2163{
2164 u64 root_objectid = 0;
2165 struct btrfs_root *gang[8];
2166 int i;
2167 int ret;
2168
2169 while (1) {
2170 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2171 (void **)gang, root_objectid,
2172 ARRAY_SIZE(gang));
2173 if (!ret)
2174 break;
2175 for (i = 0; i < ret; i++) {
2176 root_objectid = gang[i]->root_key.objectid;
2177 ret = btrfs_find_dead_roots(fs_info->tree_root,
2178 root_objectid, gang[i]);
2179 BUG_ON(ret);
2180 btrfs_orphan_cleanup(gang[i]);
2181 }
2182 root_objectid++;
2183 }
2184 return 0;
2185}
2186
2187int btrfs_commit_super(struct btrfs_root *root)
2188{
2189 struct btrfs_trans_handle *trans;
2190 int ret;
2191
2192 mutex_lock(&root->fs_info->cleaner_mutex);
2193 btrfs_clean_old_snapshots(root);
2194 mutex_unlock(&root->fs_info->cleaner_mutex);
2195 trans = btrfs_start_transaction(root, 1);
2196 ret = btrfs_commit_transaction(trans, root);
2197 BUG_ON(ret);
2198 /* run commit again to drop the original snapshot */
2199 trans = btrfs_start_transaction(root, 1);
2200 btrfs_commit_transaction(trans, root);
2201 ret = btrfs_write_and_wait_transaction(NULL, root);
2202 BUG_ON(ret);
2203
2204 ret = write_ctree_super(NULL, root, 0);
2205 return ret;
2206}
2207
2208int close_ctree(struct btrfs_root *root)
2209{
2210 struct btrfs_fs_info *fs_info = root->fs_info;
2211 int ret;
2212
2213 fs_info->closing = 1;
2214 smp_mb();
2215
2216 kthread_stop(root->fs_info->transaction_kthread);
2217 kthread_stop(root->fs_info->cleaner_kthread);
2218
2219 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2220 ret = btrfs_commit_super(root);
2221 if (ret)
2222 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2223 }
2224
2225 if (fs_info->delalloc_bytes) {
2226 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2227 fs_info->delalloc_bytes);
2228 }
2229 if (fs_info->total_ref_cache_size) {
2230 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2231 (unsigned long long)fs_info->total_ref_cache_size);
2232 }
2233
2234 if (fs_info->extent_root->node)
2235 free_extent_buffer(fs_info->extent_root->node);
2236
2237 if (fs_info->tree_root->node)
2238 free_extent_buffer(fs_info->tree_root->node);
2239
2240 if (root->fs_info->chunk_root->node)
2241 free_extent_buffer(root->fs_info->chunk_root->node);
2242
2243 if (root->fs_info->dev_root->node)
2244 free_extent_buffer(root->fs_info->dev_root->node);
2245
2246 if (root->fs_info->csum_root->node)
2247 free_extent_buffer(root->fs_info->csum_root->node);
2248
2249 btrfs_free_block_groups(root->fs_info);
2250
2251 del_fs_roots(fs_info);
2252
2253 iput(fs_info->btree_inode);
2254
2255 btrfs_stop_workers(&fs_info->fixup_workers);
2256 btrfs_stop_workers(&fs_info->delalloc_workers);
2257 btrfs_stop_workers(&fs_info->workers);
2258 btrfs_stop_workers(&fs_info->endio_workers);
2259 btrfs_stop_workers(&fs_info->endio_meta_workers);
2260 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2261 btrfs_stop_workers(&fs_info->endio_write_workers);
2262 btrfs_stop_workers(&fs_info->submit_workers);
2263
2264#if 0
2265 while (!list_empty(&fs_info->hashers)) {
2266 struct btrfs_hasher *hasher;
2267 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
2268 hashers);
2269 list_del(&hasher->hashers);
2270 crypto_free_hash(&fs_info->hash_tfm);
2271 kfree(hasher);
2272 }
2273#endif
2274 btrfs_close_devices(fs_info->fs_devices);
2275 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2276
2277 bdi_destroy(&fs_info->bdi);
2278
2279 kfree(fs_info->extent_root);
2280 kfree(fs_info->tree_root);
2281 kfree(fs_info->chunk_root);
2282 kfree(fs_info->dev_root);
2283 kfree(fs_info->csum_root);
2284 return 0;
2285}
2286
2287int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2288{
2289 int ret;
2290 struct inode *btree_inode = buf->first_page->mapping->host;
2291
2292 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2293 if (!ret)
2294 return ret;
2295
2296 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2297 parent_transid);
2298 return !ret;
2299}
2300
2301int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2302{
2303 struct inode *btree_inode = buf->first_page->mapping->host;
2304 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2305 buf);
2306}
2307
2308void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2309{
2310 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2311 u64 transid = btrfs_header_generation(buf);
2312 struct inode *btree_inode = root->fs_info->btree_inode;
2313
2314 WARN_ON(!btrfs_tree_locked(buf));
2315 if (transid != root->fs_info->generation) {
2316 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2317 "found %llu running %llu\n",
2318 (unsigned long long)buf->start,
2319 (unsigned long long)transid,
2320 (unsigned long long)root->fs_info->generation);
2321 WARN_ON(1);
2322 }
2323 set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
2324}
2325
2326void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2327{
2328 /*
2329 * looks as though older kernels can get into trouble with
2330 * this code, they end up stuck in balance_dirty_pages forever
2331 */
2332 struct extent_io_tree *tree;
2333 u64 num_dirty;
2334 u64 start = 0;
2335 unsigned long thresh = 32 * 1024 * 1024;
2336 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2337
2338 if (current_is_pdflush() || current->flags & PF_MEMALLOC)
2339 return;
2340
2341 num_dirty = count_range_bits(tree, &start, (u64)-1,
2342 thresh, EXTENT_DIRTY);
2343 if (num_dirty > thresh) {
2344 balance_dirty_pages_ratelimited_nr(
2345 root->fs_info->btree_inode->i_mapping, 1);
2346 }
2347 return;
2348}
2349
2350int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2351{
2352 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2353 int ret;
2354 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2355 if (ret == 0)
2356 buf->flags |= EXTENT_UPTODATE;
2357 return ret;
2358}
2359
2360int btree_lock_page_hook(struct page *page)
2361{
2362 struct inode *inode = page->mapping->host;
2363 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2364 struct extent_buffer *eb;
2365 unsigned long len;
2366 u64 bytenr = page_offset(page);
2367
2368 if (page->private == EXTENT_PAGE_PRIVATE)
2369 goto out;
2370
2371 len = page->private >> 2;
2372 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2373 if (!eb)
2374 goto out;
2375
2376 btrfs_tree_lock(eb);
2377 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2378 btrfs_tree_unlock(eb);
2379 free_extent_buffer(eb);
2380out:
2381 lock_page(page);
2382 return 0;
2383}
2384
2385static struct extent_io_ops btree_extent_io_ops = {
2386 .write_cache_pages_lock_hook = btree_lock_page_hook,
2387 .readpage_end_io_hook = btree_readpage_end_io_hook,
2388 .submit_bio_hook = btree_submit_bio_hook,
2389 /* note we're sharing with inode.c for the merge bio hook */
2390 .merge_bio_hook = btrfs_merge_bio_hook,
2391};
Linux 6.x block layer and io_uring tree(s)