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-rw-r--r--fs/btrfs/disk-io.c2056
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diff --git a/fs/btrfs/disk-io.c b/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/version.h>
20#include <linux/fs.h>
21#include <linux/blkdev.h>
22#include <linux/scatterlist.h>
23#include <linux/swap.h>
24#include <linux/radix-tree.h>
25#include <linux/writeback.h>
26#include <linux/buffer_head.h> // for block_sync_page
27#include <linux/workqueue.h>
28#include <linux/kthread.h>
29#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
30# include <linux/freezer.h>
31#else
32# include <linux/sched.h>
33#endif
34#include "crc32c.h"
35#include "ctree.h"
36#include "disk-io.h"
37#include "transaction.h"
38#include "btrfs_inode.h"
39#include "volumes.h"
40#include "print-tree.h"
41#include "async-thread.h"
42#include "locking.h"
43#include "ref-cache.h"
44#include "tree-log.h"
45
46#if 0
47static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
48{
49 if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
50 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
51 (unsigned long long)extent_buffer_blocknr(buf),
52 (unsigned long long)btrfs_header_blocknr(buf));
53 return 1;
54 }
55 return 0;
56}
57#endif
58
59static struct extent_io_ops btree_extent_io_ops;
60static void end_workqueue_fn(struct btrfs_work *work);
61
62struct end_io_wq {
63 struct bio *bio;
64 bio_end_io_t *end_io;
65 void *private;
66 struct btrfs_fs_info *info;
67 int error;
68 int metadata;
69 struct list_head list;
70 struct btrfs_work work;
71};
72
73struct async_submit_bio {
74 struct inode *inode;
75 struct bio *bio;
76 struct list_head list;
77 extent_submit_bio_hook_t *submit_bio_hook;
78 int rw;
79 int mirror_num;
80 struct btrfs_work work;
81};
82
83struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
84 size_t page_offset, u64 start, u64 len,
85 int create)
86{
87 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
88 struct extent_map *em;
89 int ret;
90
91 spin_lock(&em_tree->lock);
92 em = lookup_extent_mapping(em_tree, start, len);
93 if (em) {
94 em->bdev =
95 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
96 spin_unlock(&em_tree->lock);
97 goto out;
98 }
99 spin_unlock(&em_tree->lock);
100
101 em = alloc_extent_map(GFP_NOFS);
102 if (!em) {
103 em = ERR_PTR(-ENOMEM);
104 goto out;
105 }
106 em->start = 0;
107 em->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 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
118 em->start, em->len, em->block_start);
119 free_extent_map(em);
120 em = lookup_extent_mapping(em_tree, start, len);
121 if (em) {
122 printk("after failing, found %Lu %Lu %Lu\n",
123 em->start, em->len, em->block_start);
124 ret = 0;
125 } else {
126 em = lookup_extent_mapping(em_tree, failed_start,
127 failed_len);
128 if (em) {
129 printk("double failure lookup gives us "
130 "%Lu %Lu -> %Lu\n", em->start,
131 em->len, em->block_start);
132 free_extent_map(em);
133 }
134 ret = -EIO;
135 }
136 } else if (ret) {
137 free_extent_map(em);
138 em = NULL;
139 }
140 spin_unlock(&em_tree->lock);
141
142 if (ret)
143 em = ERR_PTR(ret);
144out:
145 return em;
146}
147
148u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
149{
150 return btrfs_crc32c(seed, data, len);
151}
152
153void btrfs_csum_final(u32 crc, char *result)
154{
155 *(__le32 *)result = ~cpu_to_le32(crc);
156}
157
158static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
159 int verify)
160{
161 char result[BTRFS_CRC32_SIZE];
162 unsigned long len;
163 unsigned long cur_len;
164 unsigned long offset = BTRFS_CSUM_SIZE;
165 char *map_token = NULL;
166 char *kaddr;
167 unsigned long map_start;
168 unsigned long map_len;
169 int err;
170 u32 crc = ~(u32)0;
171
172 len = buf->len - offset;
173 while(len > 0) {
174 err = map_private_extent_buffer(buf, offset, 32,
175 &map_token, &kaddr,
176 &map_start, &map_len, KM_USER0);
177 if (err) {
178 printk("failed to map extent buffer! %lu\n",
179 offset);
180 return 1;
181 }
182 cur_len = min(len, map_len - (offset - map_start));
183 crc = btrfs_csum_data(root, kaddr + offset - map_start,
184 crc, cur_len);
185 len -= cur_len;
186 offset += cur_len;
187 unmap_extent_buffer(buf, map_token, KM_USER0);
188 }
189 btrfs_csum_final(crc, result);
190
191 if (verify) {
192 /* FIXME, this is not good */
193 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
194 u32 val;
195 u32 found = 0;
196 memcpy(&found, result, BTRFS_CRC32_SIZE);
197
198 read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
199 printk("btrfs: %s checksum verify failed on %llu "
200 "wanted %X found %X level %d\n",
201 root->fs_info->sb->s_id,
202 buf->start, val, found, btrfs_header_level(buf));
203 return 1;
204 }
205 } else {
206 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
207 }
208 return 0;
209}
210
211static int verify_parent_transid(struct extent_io_tree *io_tree,
212 struct extent_buffer *eb, u64 parent_transid)
213{
214 int ret;
215
216 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
217 return 0;
218
219 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
220 if (extent_buffer_uptodate(io_tree, eb) &&
221 btrfs_header_generation(eb) == parent_transid) {
222 ret = 0;
223 goto out;
224 }
225 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
226 (unsigned long long)eb->start,
227 (unsigned long long)parent_transid,
228 (unsigned long long)btrfs_header_generation(eb));
229 ret = 1;
230 clear_extent_buffer_uptodate(io_tree, eb);
231out:
232 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
233 GFP_NOFS);
234 return ret;
235
236}
237
238static int btree_read_extent_buffer_pages(struct btrfs_root *root,
239 struct extent_buffer *eb,
240 u64 start, u64 parent_transid)
241{
242 struct extent_io_tree *io_tree;
243 int ret;
244 int num_copies = 0;
245 int mirror_num = 0;
246
247 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
248 while (1) {
249 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
250 btree_get_extent, mirror_num);
251 if (!ret &&
252 !verify_parent_transid(io_tree, eb, parent_transid))
253 return ret;
254printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror_num);
255 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
256 eb->start, eb->len);
257 if (num_copies == 1)
258 return ret;
259
260 mirror_num++;
261 if (mirror_num > num_copies)
262 return ret;
263 }
264 return -EIO;
265}
266
267int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
268{
269 struct extent_io_tree *tree;
270 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
271 u64 found_start;
272 int found_level;
273 unsigned long len;
274 struct extent_buffer *eb;
275 int ret;
276
277 tree = &BTRFS_I(page->mapping->host)->io_tree;
278
279 if (page->private == EXTENT_PAGE_PRIVATE)
280 goto out;
281 if (!page->private)
282 goto out;
283 len = page->private >> 2;
284 if (len == 0) {
285 WARN_ON(1);
286 }
287 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
288 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
289 btrfs_header_generation(eb));
290 BUG_ON(ret);
291 found_start = btrfs_header_bytenr(eb);
292 if (found_start != start) {
293 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
294 start, found_start, len);
295 WARN_ON(1);
296 goto err;
297 }
298 if (eb->first_page != page) {
299 printk("bad first page %lu %lu\n", eb->first_page->index,
300 page->index);
301 WARN_ON(1);
302 goto err;
303 }
304 if (!PageUptodate(page)) {
305 printk("csum not up to date page %lu\n", page->index);
306 WARN_ON(1);
307 goto err;
308 }
309 found_level = btrfs_header_level(eb);
310
311 csum_tree_block(root, eb, 0);
312err:
313 free_extent_buffer(eb);
314out:
315 return 0;
316}
317
318int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
319 struct extent_state *state)
320{
321 struct extent_io_tree *tree;
322 u64 found_start;
323 int found_level;
324 unsigned long len;
325 struct extent_buffer *eb;
326 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
327 int ret = 0;
328
329 tree = &BTRFS_I(page->mapping->host)->io_tree;
330 if (page->private == EXTENT_PAGE_PRIVATE)
331 goto out;
332 if (!page->private)
333 goto out;
334 len = page->private >> 2;
335 if (len == 0) {
336 WARN_ON(1);
337 }
338 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
339
340 found_start = btrfs_header_bytenr(eb);
341 if (found_start != start) {
342 printk("bad tree block start %llu %llu\n",
343 (unsigned long long)found_start,
344 (unsigned long long)eb->start);
345 ret = -EIO;
346 goto err;
347 }
348 if (eb->first_page != page) {
349 printk("bad first page %lu %lu\n", eb->first_page->index,
350 page->index);
351 WARN_ON(1);
352 ret = -EIO;
353 goto err;
354 }
355 if (memcmp_extent_buffer(eb, root->fs_info->fsid,
356 (unsigned long)btrfs_header_fsid(eb),
357 BTRFS_FSID_SIZE)) {
358 printk("bad fsid on block %Lu\n", eb->start);
359 ret = -EIO;
360 goto err;
361 }
362 found_level = btrfs_header_level(eb);
363
364 ret = csum_tree_block(root, eb, 1);
365 if (ret)
366 ret = -EIO;
367
368 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
369 end = eb->start + end - 1;
370err:
371 free_extent_buffer(eb);
372out:
373 return ret;
374}
375
376#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
377static void end_workqueue_bio(struct bio *bio, int err)
378#else
379static int end_workqueue_bio(struct bio *bio,
380 unsigned int bytes_done, int err)
381#endif
382{
383 struct end_io_wq *end_io_wq = bio->bi_private;
384 struct btrfs_fs_info *fs_info;
385
386#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
387 if (bio->bi_size)
388 return 1;
389#endif
390
391 fs_info = end_io_wq->info;
392 end_io_wq->error = err;
393 end_io_wq->work.func = end_workqueue_fn;
394 end_io_wq->work.flags = 0;
395 if (bio->bi_rw & (1 << BIO_RW))
396 btrfs_queue_worker(&fs_info->endio_write_workers,
397 &end_io_wq->work);
398 else
399 btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
400
401#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
402 return 0;
403#endif
404}
405
406int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
407 int metadata)
408{
409 struct end_io_wq *end_io_wq;
410 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
411 if (!end_io_wq)
412 return -ENOMEM;
413
414 end_io_wq->private = bio->bi_private;
415 end_io_wq->end_io = bio->bi_end_io;
416 end_io_wq->info = info;
417 end_io_wq->error = 0;
418 end_io_wq->bio = bio;
419 end_io_wq->metadata = metadata;
420
421 bio->bi_private = end_io_wq;
422 bio->bi_end_io = end_workqueue_bio;
423 return 0;
424}
425
426unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
427{
428 unsigned long limit = min_t(unsigned long,
429 info->workers.max_workers,
430 info->fs_devices->open_devices);
431 return 256 * limit;
432}
433
434int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
435{
436 return atomic_read(&info->nr_async_bios) >
437 btrfs_async_submit_limit(info);
438}
439
440static void run_one_async_submit(struct btrfs_work *work)
441{
442 struct btrfs_fs_info *fs_info;
443 struct async_submit_bio *async;
444 int limit;
445
446 async = container_of(work, struct async_submit_bio, work);
447 fs_info = BTRFS_I(async->inode)->root->fs_info;
448
449 limit = btrfs_async_submit_limit(fs_info);
450 limit = limit * 2 / 3;
451
452 atomic_dec(&fs_info->nr_async_submits);
453
454 if (atomic_read(&fs_info->nr_async_submits) < limit &&
455 waitqueue_active(&fs_info->async_submit_wait))
456 wake_up(&fs_info->async_submit_wait);
457
458 async->submit_bio_hook(async->inode, async->rw, async->bio,
459 async->mirror_num);
460 kfree(async);
461}
462
463int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
464 int rw, struct bio *bio, int mirror_num,
465 extent_submit_bio_hook_t *submit_bio_hook)
466{
467 struct async_submit_bio *async;
468 int limit = btrfs_async_submit_limit(fs_info);
469
470 async = kmalloc(sizeof(*async), GFP_NOFS);
471 if (!async)
472 return -ENOMEM;
473
474 async->inode = inode;
475 async->rw = rw;
476 async->bio = bio;
477 async->mirror_num = mirror_num;
478 async->submit_bio_hook = submit_bio_hook;
479 async->work.func = run_one_async_submit;
480 async->work.flags = 0;
481 atomic_inc(&fs_info->nr_async_submits);
482 btrfs_queue_worker(&fs_info->workers, &async->work);
483
484 if (atomic_read(&fs_info->nr_async_submits) > limit) {
485 wait_event_timeout(fs_info->async_submit_wait,
486 (atomic_read(&fs_info->nr_async_submits) < limit),
487 HZ/10);
488
489 wait_event_timeout(fs_info->async_submit_wait,
490 (atomic_read(&fs_info->nr_async_bios) < limit),
491 HZ/10);
492 }
493 return 0;
494}
495
496static int btree_csum_one_bio(struct bio *bio)
497{
498 struct bio_vec *bvec = bio->bi_io_vec;
499 int bio_index = 0;
500 struct btrfs_root *root;
501
502 WARN_ON(bio->bi_vcnt <= 0);
503 while(bio_index < bio->bi_vcnt) {
504 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
505 csum_dirty_buffer(root, bvec->bv_page);
506 bio_index++;
507 bvec++;
508 }
509 return 0;
510}
511
512static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
513 int mirror_num)
514{
515 struct btrfs_root *root = BTRFS_I(inode)->root;
516 u64 offset;
517 int ret;
518
519 offset = bio->bi_sector << 9;
520
521 /*
522 * when we're called for a write, we're already in the async
523 * submission context. Just jump into btrfs_map_bio
524 */
525 if (rw & (1 << BIO_RW)) {
526 btree_csum_one_bio(bio);
527 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
528 mirror_num, 1);
529 }
530
531 /*
532 * called for a read, do the setup so that checksum validation
533 * can happen in the async kernel threads
534 */
535 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
536 BUG_ON(ret);
537
538 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
539}
540
541static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
542 int mirror_num)
543{
544 /*
545 * kthread helpers are used to submit writes so that checksumming
546 * can happen in parallel across all CPUs
547 */
548 if (!(rw & (1 << BIO_RW))) {
549 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
550 }
551 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
552 inode, rw, bio, mirror_num,
553 __btree_submit_bio_hook);
554}
555
556static int btree_writepage(struct page *page, struct writeback_control *wbc)
557{
558 struct extent_io_tree *tree;
559 tree = &BTRFS_I(page->mapping->host)->io_tree;
560
561 if (current->flags & PF_MEMALLOC) {
562 redirty_page_for_writepage(wbc, page);
563 unlock_page(page);
564 return 0;
565 }
566 return extent_write_full_page(tree, page, btree_get_extent, wbc);
567}
568
569static int btree_writepages(struct address_space *mapping,
570 struct writeback_control *wbc)
571{
572 struct extent_io_tree *tree;
573 tree = &BTRFS_I(mapping->host)->io_tree;
574 if (wbc->sync_mode == WB_SYNC_NONE) {
575 u64 num_dirty;
576 u64 start = 0;
577 unsigned long thresh = 8 * 1024 * 1024;
578
579 if (wbc->for_kupdate)
580 return 0;
581
582 num_dirty = count_range_bits(tree, &start, (u64)-1,
583 thresh, EXTENT_DIRTY);
584 if (num_dirty < thresh) {
585 return 0;
586 }
587 }
588 return extent_writepages(tree, mapping, btree_get_extent, wbc);
589}
590
591int btree_readpage(struct file *file, struct page *page)
592{
593 struct extent_io_tree *tree;
594 tree = &BTRFS_I(page->mapping->host)->io_tree;
595 return extent_read_full_page(tree, page, btree_get_extent);
596}
597
598static int btree_releasepage(struct page *page, gfp_t gfp_flags)
599{
600 struct extent_io_tree *tree;
601 struct extent_map_tree *map;
602 int ret;
603
604 if (PageWriteback(page) || PageDirty(page))
605 return 0;
606
607 tree = &BTRFS_I(page->mapping->host)->io_tree;
608 map = &BTRFS_I(page->mapping->host)->extent_tree;
609
610 ret = try_release_extent_state(map, tree, page, gfp_flags);
611 if (!ret) {
612 return 0;
613 }
614
615 ret = try_release_extent_buffer(tree, page);
616 if (ret == 1) {
617 ClearPagePrivate(page);
618 set_page_private(page, 0);
619 page_cache_release(page);
620 }
621
622 return ret;
623}
624
625static void btree_invalidatepage(struct page *page, unsigned long offset)
626{
627 struct extent_io_tree *tree;
628 tree = &BTRFS_I(page->mapping->host)->io_tree;
629 extent_invalidatepage(tree, page, offset);
630 btree_releasepage(page, GFP_NOFS);
631 if (PagePrivate(page)) {
632 printk("warning page private not zero on page %Lu\n",
633 page_offset(page));
634 ClearPagePrivate(page);
635 set_page_private(page, 0);
636 page_cache_release(page);
637 }
638}
639
640#if 0
641static int btree_writepage(struct page *page, struct writeback_control *wbc)
642{
643 struct buffer_head *bh;
644 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
645 struct buffer_head *head;
646 if (!page_has_buffers(page)) {
647 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
648 (1 << BH_Dirty)|(1 << BH_Uptodate));
649 }
650 head = page_buffers(page);
651 bh = head;
652 do {
653 if (buffer_dirty(bh))
654 csum_tree_block(root, bh, 0);
655 bh = bh->b_this_page;
656 } while (bh != head);
657 return block_write_full_page(page, btree_get_block, wbc);
658}
659#endif
660
661static struct address_space_operations btree_aops = {
662 .readpage = btree_readpage,
663 .writepage = btree_writepage,
664 .writepages = btree_writepages,
665 .releasepage = btree_releasepage,
666 .invalidatepage = btree_invalidatepage,
667 .sync_page = block_sync_page,
668};
669
670int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
671 u64 parent_transid)
672{
673 struct extent_buffer *buf = NULL;
674 struct inode *btree_inode = root->fs_info->btree_inode;
675 int ret = 0;
676
677 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
678 if (!buf)
679 return 0;
680 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
681 buf, 0, 0, btree_get_extent, 0);
682 free_extent_buffer(buf);
683 return ret;
684}
685
686struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
687 u64 bytenr, u32 blocksize)
688{
689 struct inode *btree_inode = root->fs_info->btree_inode;
690 struct extent_buffer *eb;
691 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
692 bytenr, blocksize, GFP_NOFS);
693 return eb;
694}
695
696struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
697 u64 bytenr, u32 blocksize)
698{
699 struct inode *btree_inode = root->fs_info->btree_inode;
700 struct extent_buffer *eb;
701
702 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
703 bytenr, blocksize, NULL, GFP_NOFS);
704 return eb;
705}
706
707
708int btrfs_write_tree_block(struct extent_buffer *buf)
709{
710 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
711 buf->start + buf->len - 1, WB_SYNC_NONE);
712}
713
714int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
715{
716 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
717 buf->start, buf->start + buf->len -1);
718}
719
720struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
721 u32 blocksize, u64 parent_transid)
722{
723 struct extent_buffer *buf = NULL;
724 struct inode *btree_inode = root->fs_info->btree_inode;
725 struct extent_io_tree *io_tree;
726 int ret;
727
728 io_tree = &BTRFS_I(btree_inode)->io_tree;
729
730 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
731 if (!buf)
732 return NULL;
733
734 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
735
736 if (ret == 0) {
737 buf->flags |= EXTENT_UPTODATE;
738 } else {
739 WARN_ON(1);
740 }
741 return buf;
742
743}
744
745int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
746 struct extent_buffer *buf)
747{
748 struct inode *btree_inode = root->fs_info->btree_inode;
749 if (btrfs_header_generation(buf) ==
750 root->fs_info->running_transaction->transid) {
751 WARN_ON(!btrfs_tree_locked(buf));
752 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
753 buf);
754 }
755 return 0;
756}
757
758static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
759 u32 stripesize, struct btrfs_root *root,
760 struct btrfs_fs_info *fs_info,
761 u64 objectid)
762{
763 root->node = NULL;
764 root->inode = NULL;
765 root->commit_root = NULL;
766 root->ref_tree = NULL;
767 root->sectorsize = sectorsize;
768 root->nodesize = nodesize;
769 root->leafsize = leafsize;
770 root->stripesize = stripesize;
771 root->ref_cows = 0;
772 root->track_dirty = 0;
773
774 root->fs_info = fs_info;
775 root->objectid = objectid;
776 root->last_trans = 0;
777 root->highest_inode = 0;
778 root->last_inode_alloc = 0;
779 root->name = NULL;
780 root->in_sysfs = 0;
781
782 INIT_LIST_HEAD(&root->dirty_list);
783 INIT_LIST_HEAD(&root->orphan_list);
784 INIT_LIST_HEAD(&root->dead_list);
785 spin_lock_init(&root->node_lock);
786 spin_lock_init(&root->list_lock);
787 mutex_init(&root->objectid_mutex);
788 mutex_init(&root->log_mutex);
789 extent_io_tree_init(&root->dirty_log_pages,
790 fs_info->btree_inode->i_mapping, GFP_NOFS);
791
792 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
793 root->ref_tree = &root->ref_tree_struct;
794
795 memset(&root->root_key, 0, sizeof(root->root_key));
796 memset(&root->root_item, 0, sizeof(root->root_item));
797 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
798 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
799 root->defrag_trans_start = fs_info->generation;
800 init_completion(&root->kobj_unregister);
801 root->defrag_running = 0;
802 root->defrag_level = 0;
803 root->root_key.objectid = objectid;
804 return 0;
805}
806
807static int find_and_setup_root(struct btrfs_root *tree_root,
808 struct btrfs_fs_info *fs_info,
809 u64 objectid,
810 struct btrfs_root *root)
811{
812 int ret;
813 u32 blocksize;
814
815 __setup_root(tree_root->nodesize, tree_root->leafsize,
816 tree_root->sectorsize, tree_root->stripesize,
817 root, fs_info, objectid);
818 ret = btrfs_find_last_root(tree_root, objectid,
819 &root->root_item, &root->root_key);
820 BUG_ON(ret);
821
822 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
823 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
824 blocksize, 0);
825 BUG_ON(!root->node);
826 return 0;
827}
828
829int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
830 struct btrfs_fs_info *fs_info)
831{
832 struct extent_buffer *eb;
833 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
834 u64 start = 0;
835 u64 end = 0;
836 int ret;
837
838 if (!log_root_tree)
839 return 0;
840
841 while(1) {
842 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
843 0, &start, &end, EXTENT_DIRTY);
844 if (ret)
845 break;
846
847 clear_extent_dirty(&log_root_tree->dirty_log_pages,
848 start, end, GFP_NOFS);
849 }
850 eb = fs_info->log_root_tree->node;
851
852 WARN_ON(btrfs_header_level(eb) != 0);
853 WARN_ON(btrfs_header_nritems(eb) != 0);
854
855 ret = btrfs_free_reserved_extent(fs_info->tree_root,
856 eb->start, eb->len);
857 BUG_ON(ret);
858
859 free_extent_buffer(eb);
860 kfree(fs_info->log_root_tree);
861 fs_info->log_root_tree = NULL;
862 return 0;
863}
864
865int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
866 struct btrfs_fs_info *fs_info)
867{
868 struct btrfs_root *root;
869 struct btrfs_root *tree_root = fs_info->tree_root;
870
871 root = kzalloc(sizeof(*root), GFP_NOFS);
872 if (!root)
873 return -ENOMEM;
874
875 __setup_root(tree_root->nodesize, tree_root->leafsize,
876 tree_root->sectorsize, tree_root->stripesize,
877 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
878
879 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
880 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
881 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
882 root->ref_cows = 0;
883
884 root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
885 0, BTRFS_TREE_LOG_OBJECTID,
886 trans->transid, 0, 0, 0);
887
888 btrfs_set_header_nritems(root->node, 0);
889 btrfs_set_header_level(root->node, 0);
890 btrfs_set_header_bytenr(root->node, root->node->start);
891 btrfs_set_header_generation(root->node, trans->transid);
892 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
893
894 write_extent_buffer(root->node, root->fs_info->fsid,
895 (unsigned long)btrfs_header_fsid(root->node),
896 BTRFS_FSID_SIZE);
897 btrfs_mark_buffer_dirty(root->node);
898 btrfs_tree_unlock(root->node);
899 fs_info->log_root_tree = root;
900 return 0;
901}
902
903struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
904 struct btrfs_key *location)
905{
906 struct btrfs_root *root;
907 struct btrfs_fs_info *fs_info = tree_root->fs_info;
908 struct btrfs_path *path;
909 struct extent_buffer *l;
910 u64 highest_inode;
911 u32 blocksize;
912 int ret = 0;
913
914 root = kzalloc(sizeof(*root), GFP_NOFS);
915 if (!root)
916 return ERR_PTR(-ENOMEM);
917 if (location->offset == (u64)-1) {
918 ret = find_and_setup_root(tree_root, fs_info,
919 location->objectid, root);
920 if (ret) {
921 kfree(root);
922 return ERR_PTR(ret);
923 }
924 goto insert;
925 }
926
927 __setup_root(tree_root->nodesize, tree_root->leafsize,
928 tree_root->sectorsize, tree_root->stripesize,
929 root, fs_info, location->objectid);
930
931 path = btrfs_alloc_path();
932 BUG_ON(!path);
933 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
934 if (ret != 0) {
935 if (ret > 0)
936 ret = -ENOENT;
937 goto out;
938 }
939 l = path->nodes[0];
940 read_extent_buffer(l, &root->root_item,
941 btrfs_item_ptr_offset(l, path->slots[0]),
942 sizeof(root->root_item));
943 memcpy(&root->root_key, location, sizeof(*location));
944 ret = 0;
945out:
946 btrfs_release_path(root, path);
947 btrfs_free_path(path);
948 if (ret) {
949 kfree(root);
950 return ERR_PTR(ret);
951 }
952 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
953 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
954 blocksize, 0);
955 BUG_ON(!root->node);
956insert:
957 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
958 root->ref_cows = 1;
959 ret = btrfs_find_highest_inode(root, &highest_inode);
960 if (ret == 0) {
961 root->highest_inode = highest_inode;
962 root->last_inode_alloc = highest_inode;
963 }
964 }
965 return root;
966}
967
968struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
969 u64 root_objectid)
970{
971 struct btrfs_root *root;
972
973 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
974 return fs_info->tree_root;
975 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
976 return fs_info->extent_root;
977
978 root = radix_tree_lookup(&fs_info->fs_roots_radix,
979 (unsigned long)root_objectid);
980 return root;
981}
982
983struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
984 struct btrfs_key *location)
985{
986 struct btrfs_root *root;
987 int ret;
988
989 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
990 return fs_info->tree_root;
991 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
992 return fs_info->extent_root;
993 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
994 return fs_info->chunk_root;
995 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
996 return fs_info->dev_root;
997
998 root = radix_tree_lookup(&fs_info->fs_roots_radix,
999 (unsigned long)location->objectid);
1000 if (root)
1001 return root;
1002
1003 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1004 if (IS_ERR(root))
1005 return root;
1006 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1007 (unsigned long)root->root_key.objectid,
1008 root);
1009 if (ret) {
1010 free_extent_buffer(root->node);
1011 kfree(root);
1012 return ERR_PTR(ret);
1013 }
1014 ret = btrfs_find_dead_roots(fs_info->tree_root,
1015 root->root_key.objectid, root);
1016 BUG_ON(ret);
1017
1018 return root;
1019}
1020
1021struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1022 struct btrfs_key *location,
1023 const char *name, int namelen)
1024{
1025 struct btrfs_root *root;
1026 int ret;
1027
1028 root = btrfs_read_fs_root_no_name(fs_info, location);
1029 if (!root)
1030 return NULL;
1031
1032 if (root->in_sysfs)
1033 return root;
1034
1035 ret = btrfs_set_root_name(root, name, namelen);
1036 if (ret) {
1037 free_extent_buffer(root->node);
1038 kfree(root);
1039 return ERR_PTR(ret);
1040 }
1041
1042 ret = btrfs_sysfs_add_root(root);
1043 if (ret) {
1044 free_extent_buffer(root->node);
1045 kfree(root->name);
1046 kfree(root);
1047 return ERR_PTR(ret);
1048 }
1049 root->in_sysfs = 1;
1050 return root;
1051}
1052#if 0
1053static int add_hasher(struct btrfs_fs_info *info, char *type) {
1054 struct btrfs_hasher *hasher;
1055
1056 hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
1057 if (!hasher)
1058 return -ENOMEM;
1059 hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
1060 if (!hasher->hash_tfm) {
1061 kfree(hasher);
1062 return -EINVAL;
1063 }
1064 spin_lock(&info->hash_lock);
1065 list_add(&hasher->list, &info->hashers);
1066 spin_unlock(&info->hash_lock);
1067 return 0;
1068}
1069#endif
1070
1071static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1072{
1073 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1074 int ret = 0;
1075 struct list_head *cur;
1076 struct btrfs_device *device;
1077 struct backing_dev_info *bdi;
1078
1079 if ((bdi_bits & (1 << BDI_write_congested)) &&
1080 btrfs_congested_async(info, 0))
1081 return 1;
1082
1083 list_for_each(cur, &info->fs_devices->devices) {
1084 device = list_entry(cur, struct btrfs_device, dev_list);
1085 if (!device->bdev)
1086 continue;
1087 bdi = blk_get_backing_dev_info(device->bdev);
1088 if (bdi && bdi_congested(bdi, bdi_bits)) {
1089 ret = 1;
1090 break;
1091 }
1092 }
1093 return ret;
1094}
1095
1096/*
1097 * this unplugs every device on the box, and it is only used when page
1098 * is null
1099 */
1100static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1101{
1102 struct list_head *cur;
1103 struct btrfs_device *device;
1104 struct btrfs_fs_info *info;
1105
1106 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1107 list_for_each(cur, &info->fs_devices->devices) {
1108 device = list_entry(cur, struct btrfs_device, dev_list);
1109 bdi = blk_get_backing_dev_info(device->bdev);
1110 if (bdi->unplug_io_fn) {
1111 bdi->unplug_io_fn(bdi, page);
1112 }
1113 }
1114}
1115
1116void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1117{
1118 struct inode *inode;
1119 struct extent_map_tree *em_tree;
1120 struct extent_map *em;
1121 struct address_space *mapping;
1122 u64 offset;
1123
1124 /* the generic O_DIRECT read code does this */
1125 if (!page) {
1126 __unplug_io_fn(bdi, page);
1127 return;
1128 }
1129
1130 /*
1131 * page->mapping may change at any time. Get a consistent copy
1132 * and use that for everything below
1133 */
1134 smp_mb();
1135 mapping = page->mapping;
1136 if (!mapping)
1137 return;
1138
1139 inode = mapping->host;
1140 offset = page_offset(page);
1141
1142 em_tree = &BTRFS_I(inode)->extent_tree;
1143 spin_lock(&em_tree->lock);
1144 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1145 spin_unlock(&em_tree->lock);
1146 if (!em) {
1147 __unplug_io_fn(bdi, page);
1148 return;
1149 }
1150
1151 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1152 free_extent_map(em);
1153 __unplug_io_fn(bdi, page);
1154 return;
1155 }
1156 offset = offset - em->start;
1157 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1158 em->block_start + offset, page);
1159 free_extent_map(em);
1160}
1161
1162static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1163{
1164#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1165 bdi_init(bdi);
1166#endif
1167 bdi->ra_pages = default_backing_dev_info.ra_pages;
1168 bdi->state = 0;
1169 bdi->capabilities = default_backing_dev_info.capabilities;
1170 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1171 bdi->unplug_io_data = info;
1172 bdi->congested_fn = btrfs_congested_fn;
1173 bdi->congested_data = info;
1174 return 0;
1175}
1176
1177static int bio_ready_for_csum(struct bio *bio)
1178{
1179 u64 length = 0;
1180 u64 buf_len = 0;
1181 u64 start = 0;
1182 struct page *page;
1183 struct extent_io_tree *io_tree = NULL;
1184 struct btrfs_fs_info *info = NULL;
1185 struct bio_vec *bvec;
1186 int i;
1187 int ret;
1188
1189 bio_for_each_segment(bvec, bio, i) {
1190 page = bvec->bv_page;
1191 if (page->private == EXTENT_PAGE_PRIVATE) {
1192 length += bvec->bv_len;
1193 continue;
1194 }
1195 if (!page->private) {
1196 length += bvec->bv_len;
1197 continue;
1198 }
1199 length = bvec->bv_len;
1200 buf_len = page->private >> 2;
1201 start = page_offset(page) + bvec->bv_offset;
1202 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1203 info = BTRFS_I(page->mapping->host)->root->fs_info;
1204 }
1205 /* are we fully contained in this bio? */
1206 if (buf_len <= length)
1207 return 1;
1208
1209 ret = extent_range_uptodate(io_tree, start + length,
1210 start + buf_len - 1);
1211 if (ret == 1)
1212 return ret;
1213 return ret;
1214}
1215
1216/*
1217 * called by the kthread helper functions to finally call the bio end_io
1218 * functions. This is where read checksum verification actually happens
1219 */
1220static void end_workqueue_fn(struct btrfs_work *work)
1221{
1222 struct bio *bio;
1223 struct end_io_wq *end_io_wq;
1224 struct btrfs_fs_info *fs_info;
1225 int error;
1226
1227 end_io_wq = container_of(work, struct end_io_wq, work);
1228 bio = end_io_wq->bio;
1229 fs_info = end_io_wq->info;
1230
1231 /* metadata bios are special because the whole tree block must
1232 * be checksummed at once. This makes sure the entire block is in
1233 * ram and up to date before trying to verify things. For
1234 * blocksize <= pagesize, it is basically a noop
1235 */
1236 if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1237 btrfs_queue_worker(&fs_info->endio_workers,
1238 &end_io_wq->work);
1239 return;
1240 }
1241 error = end_io_wq->error;
1242 bio->bi_private = end_io_wq->private;
1243 bio->bi_end_io = end_io_wq->end_io;
1244 kfree(end_io_wq);
1245#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1246 bio_endio(bio, bio->bi_size, error);
1247#else
1248 bio_endio(bio, error);
1249#endif
1250}
1251
1252static int cleaner_kthread(void *arg)
1253{
1254 struct btrfs_root *root = arg;
1255
1256 do {
1257 smp_mb();
1258 if (root->fs_info->closing)
1259 break;
1260
1261 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1262 mutex_lock(&root->fs_info->cleaner_mutex);
1263 btrfs_clean_old_snapshots(root);
1264 mutex_unlock(&root->fs_info->cleaner_mutex);
1265
1266 if (freezing(current)) {
1267 refrigerator();
1268 } else {
1269 smp_mb();
1270 if (root->fs_info->closing)
1271 break;
1272 set_current_state(TASK_INTERRUPTIBLE);
1273 schedule();
1274 __set_current_state(TASK_RUNNING);
1275 }
1276 } while (!kthread_should_stop());
1277 return 0;
1278}
1279
1280static int transaction_kthread(void *arg)
1281{
1282 struct btrfs_root *root = arg;
1283 struct btrfs_trans_handle *trans;
1284 struct btrfs_transaction *cur;
1285 unsigned long now;
1286 unsigned long delay;
1287 int ret;
1288
1289 do {
1290 smp_mb();
1291 if (root->fs_info->closing)
1292 break;
1293
1294 delay = HZ * 30;
1295 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1296 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1297
1298 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1299 printk("btrfs: total reference cache size %Lu\n",
1300 root->fs_info->total_ref_cache_size);
1301 }
1302
1303 mutex_lock(&root->fs_info->trans_mutex);
1304 cur = root->fs_info->running_transaction;
1305 if (!cur) {
1306 mutex_unlock(&root->fs_info->trans_mutex);
1307 goto sleep;
1308 }
1309
1310 now = get_seconds();
1311 if (now < cur->start_time || now - cur->start_time < 30) {
1312 mutex_unlock(&root->fs_info->trans_mutex);
1313 delay = HZ * 5;
1314 goto sleep;
1315 }
1316 mutex_unlock(&root->fs_info->trans_mutex);
1317 trans = btrfs_start_transaction(root, 1);
1318 ret = btrfs_commit_transaction(trans, root);
1319sleep:
1320 wake_up_process(root->fs_info->cleaner_kthread);
1321 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1322
1323 if (freezing(current)) {
1324 refrigerator();
1325 } else {
1326 if (root->fs_info->closing)
1327 break;
1328 set_current_state(TASK_INTERRUPTIBLE);
1329 schedule_timeout(delay);
1330 __set_current_state(TASK_RUNNING);
1331 }
1332 } while (!kthread_should_stop());
1333 return 0;
1334}
1335
1336struct btrfs_root *open_ctree(struct super_block *sb,
1337 struct btrfs_fs_devices *fs_devices,
1338 char *options)
1339{
1340 u32 sectorsize;
1341 u32 nodesize;
1342 u32 leafsize;
1343 u32 blocksize;
1344 u32 stripesize;
1345 struct buffer_head *bh;
1346 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1347 GFP_NOFS);
1348 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1349 GFP_NOFS);
1350 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1351 GFP_NOFS);
1352 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1353 GFP_NOFS);
1354 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1355 GFP_NOFS);
1356 struct btrfs_root *log_tree_root;
1357
1358 int ret;
1359 int err = -EINVAL;
1360
1361 struct btrfs_super_block *disk_super;
1362
1363 if (!extent_root || !tree_root || !fs_info) {
1364 err = -ENOMEM;
1365 goto fail;
1366 }
1367 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1368 INIT_LIST_HEAD(&fs_info->trans_list);
1369 INIT_LIST_HEAD(&fs_info->dead_roots);
1370 INIT_LIST_HEAD(&fs_info->hashers);
1371 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1372 spin_lock_init(&fs_info->hash_lock);
1373 spin_lock_init(&fs_info->delalloc_lock);
1374 spin_lock_init(&fs_info->new_trans_lock);
1375 spin_lock_init(&fs_info->ref_cache_lock);
1376
1377 init_completion(&fs_info->kobj_unregister);
1378 fs_info->tree_root = tree_root;
1379 fs_info->extent_root = extent_root;
1380 fs_info->chunk_root = chunk_root;
1381 fs_info->dev_root = dev_root;
1382 fs_info->fs_devices = fs_devices;
1383 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1384 INIT_LIST_HEAD(&fs_info->space_info);
1385 btrfs_mapping_init(&fs_info->mapping_tree);
1386 atomic_set(&fs_info->nr_async_submits, 0);
1387 atomic_set(&fs_info->nr_async_bios, 0);
1388 atomic_set(&fs_info->throttles, 0);
1389 atomic_set(&fs_info->throttle_gen, 0);
1390 fs_info->sb = sb;
1391 fs_info->max_extent = (u64)-1;
1392 fs_info->max_inline = 8192 * 1024;
1393 setup_bdi(fs_info, &fs_info->bdi);
1394 fs_info->btree_inode = new_inode(sb);
1395 fs_info->btree_inode->i_ino = 1;
1396 fs_info->btree_inode->i_nlink = 1;
1397 fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1398
1399 INIT_LIST_HEAD(&fs_info->ordered_extents);
1400 spin_lock_init(&fs_info->ordered_extent_lock);
1401
1402 sb->s_blocksize = 4096;
1403 sb->s_blocksize_bits = blksize_bits(4096);
1404
1405 /*
1406 * we set the i_size on the btree inode to the max possible int.
1407 * the real end of the address space is determined by all of
1408 * the devices in the system
1409 */
1410 fs_info->btree_inode->i_size = OFFSET_MAX;
1411 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1412 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1413
1414 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1415 fs_info->btree_inode->i_mapping,
1416 GFP_NOFS);
1417 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1418 GFP_NOFS);
1419
1420 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1421
1422 spin_lock_init(&fs_info->block_group_cache_lock);
1423 fs_info->block_group_cache_tree.rb_node = NULL;
1424
1425 extent_io_tree_init(&fs_info->pinned_extents,
1426 fs_info->btree_inode->i_mapping, GFP_NOFS);
1427 extent_io_tree_init(&fs_info->pending_del,
1428 fs_info->btree_inode->i_mapping, GFP_NOFS);
1429 extent_io_tree_init(&fs_info->extent_ins,
1430 fs_info->btree_inode->i_mapping, GFP_NOFS);
1431 fs_info->do_barriers = 1;
1432
1433 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1434 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1435 sizeof(struct btrfs_key));
1436 insert_inode_hash(fs_info->btree_inode);
1437
1438 mutex_init(&fs_info->trans_mutex);
1439 mutex_init(&fs_info->tree_log_mutex);
1440 mutex_init(&fs_info->drop_mutex);
1441 mutex_init(&fs_info->alloc_mutex);
1442 mutex_init(&fs_info->chunk_mutex);
1443 mutex_init(&fs_info->transaction_kthread_mutex);
1444 mutex_init(&fs_info->cleaner_mutex);
1445 mutex_init(&fs_info->volume_mutex);
1446 init_waitqueue_head(&fs_info->transaction_throttle);
1447 init_waitqueue_head(&fs_info->transaction_wait);
1448 init_waitqueue_head(&fs_info->async_submit_wait);
1449 init_waitqueue_head(&fs_info->tree_log_wait);
1450 atomic_set(&fs_info->tree_log_commit, 0);
1451 atomic_set(&fs_info->tree_log_writers, 0);
1452 fs_info->tree_log_transid = 0;
1453
1454#if 0
1455 ret = add_hasher(fs_info, "crc32c");
1456 if (ret) {
1457 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1458 err = -ENOMEM;
1459 goto fail_iput;
1460 }
1461#endif
1462 __setup_root(4096, 4096, 4096, 4096, tree_root,
1463 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1464
1465
1466 bh = __bread(fs_devices->latest_bdev,
1467 BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1468 if (!bh)
1469 goto fail_iput;
1470
1471 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1472 brelse(bh);
1473
1474 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1475
1476 disk_super = &fs_info->super_copy;
1477 if (!btrfs_super_root(disk_super))
1478 goto fail_sb_buffer;
1479
1480 err = btrfs_parse_options(tree_root, options);
1481 if (err)
1482 goto fail_sb_buffer;
1483
1484 /*
1485 * we need to start all the end_io workers up front because the
1486 * queue work function gets called at interrupt time, and so it
1487 * cannot dynamically grow.
1488 */
1489 btrfs_init_workers(&fs_info->workers, "worker",
1490 fs_info->thread_pool_size);
1491 btrfs_init_workers(&fs_info->submit_workers, "submit",
1492 min_t(u64, fs_devices->num_devices,
1493 fs_info->thread_pool_size));
1494
1495 /* a higher idle thresh on the submit workers makes it much more
1496 * likely that bios will be send down in a sane order to the
1497 * devices
1498 */
1499 fs_info->submit_workers.idle_thresh = 64;
1500
1501 /* fs_info->workers is responsible for checksumming file data
1502 * blocks and metadata. Using a larger idle thresh allows each
1503 * worker thread to operate on things in roughly the order they
1504 * were sent by the writeback daemons, improving overall locality
1505 * of the IO going down the pipe.
1506 */
1507 fs_info->workers.idle_thresh = 128;
1508
1509 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1510 btrfs_init_workers(&fs_info->endio_workers, "endio",
1511 fs_info->thread_pool_size);
1512 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1513 fs_info->thread_pool_size);
1514
1515 /*
1516 * endios are largely parallel and should have a very
1517 * low idle thresh
1518 */
1519 fs_info->endio_workers.idle_thresh = 4;
1520 fs_info->endio_write_workers.idle_thresh = 64;
1521
1522 btrfs_start_workers(&fs_info->workers, 1);
1523 btrfs_start_workers(&fs_info->submit_workers, 1);
1524 btrfs_start_workers(&fs_info->fixup_workers, 1);
1525 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1526 btrfs_start_workers(&fs_info->endio_write_workers,
1527 fs_info->thread_pool_size);
1528
1529 err = -EINVAL;
1530 if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1531 printk("Btrfs: wanted %llu devices, but found %llu\n",
1532 (unsigned long long)btrfs_super_num_devices(disk_super),
1533 (unsigned long long)fs_devices->open_devices);
1534 if (btrfs_test_opt(tree_root, DEGRADED))
1535 printk("continuing in degraded mode\n");
1536 else {
1537 goto fail_sb_buffer;
1538 }
1539 }
1540
1541 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1542
1543 nodesize = btrfs_super_nodesize(disk_super);
1544 leafsize = btrfs_super_leafsize(disk_super);
1545 sectorsize = btrfs_super_sectorsize(disk_super);
1546 stripesize = btrfs_super_stripesize(disk_super);
1547 tree_root->nodesize = nodesize;
1548 tree_root->leafsize = leafsize;
1549 tree_root->sectorsize = sectorsize;
1550 tree_root->stripesize = stripesize;
1551
1552 sb->s_blocksize = sectorsize;
1553 sb->s_blocksize_bits = blksize_bits(sectorsize);
1554
1555 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1556 sizeof(disk_super->magic))) {
1557 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1558 goto fail_sb_buffer;
1559 }
1560
1561 mutex_lock(&fs_info->chunk_mutex);
1562 ret = btrfs_read_sys_array(tree_root);
1563 mutex_unlock(&fs_info->chunk_mutex);
1564 if (ret) {
1565 printk("btrfs: failed to read the system array on %s\n",
1566 sb->s_id);
1567 goto fail_sys_array;
1568 }
1569
1570 blocksize = btrfs_level_size(tree_root,
1571 btrfs_super_chunk_root_level(disk_super));
1572
1573 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1574 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1575
1576 chunk_root->node = read_tree_block(chunk_root,
1577 btrfs_super_chunk_root(disk_super),
1578 blocksize, 0);
1579 BUG_ON(!chunk_root->node);
1580
1581 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1582 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1583 BTRFS_UUID_SIZE);
1584
1585 mutex_lock(&fs_info->chunk_mutex);
1586 ret = btrfs_read_chunk_tree(chunk_root);
1587 mutex_unlock(&fs_info->chunk_mutex);
1588 BUG_ON(ret);
1589
1590 btrfs_close_extra_devices(fs_devices);
1591
1592 blocksize = btrfs_level_size(tree_root,
1593 btrfs_super_root_level(disk_super));
1594
1595
1596 tree_root->node = read_tree_block(tree_root,
1597 btrfs_super_root(disk_super),
1598 blocksize, 0);
1599 if (!tree_root->node)
1600 goto fail_sb_buffer;
1601
1602
1603 ret = find_and_setup_root(tree_root, fs_info,
1604 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1605 if (ret)
1606 goto fail_tree_root;
1607 extent_root->track_dirty = 1;
1608
1609 ret = find_and_setup_root(tree_root, fs_info,
1610 BTRFS_DEV_TREE_OBJECTID, dev_root);
1611 dev_root->track_dirty = 1;
1612
1613 if (ret)
1614 goto fail_extent_root;
1615
1616 btrfs_read_block_groups(extent_root);
1617
1618 fs_info->generation = btrfs_super_generation(disk_super) + 1;
1619 fs_info->data_alloc_profile = (u64)-1;
1620 fs_info->metadata_alloc_profile = (u64)-1;
1621 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1622 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1623 "btrfs-cleaner");
1624 if (!fs_info->cleaner_kthread)
1625 goto fail_extent_root;
1626
1627 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1628 tree_root,
1629 "btrfs-transaction");
1630 if (!fs_info->transaction_kthread)
1631 goto fail_cleaner;
1632
1633 if (btrfs_super_log_root(disk_super) != 0) {
1634 u32 blocksize;
1635 u64 bytenr = btrfs_super_log_root(disk_super);
1636
1637 blocksize =
1638 btrfs_level_size(tree_root,
1639 btrfs_super_log_root_level(disk_super));
1640
1641 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1642 GFP_NOFS);
1643
1644 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1645 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1646
1647 log_tree_root->node = read_tree_block(tree_root, bytenr,
1648 blocksize, 0);
1649 ret = btrfs_recover_log_trees(log_tree_root);
1650 BUG_ON(ret);
1651 }
1652 fs_info->last_trans_committed = btrfs_super_generation(disk_super);
1653 return tree_root;
1654
1655fail_cleaner:
1656 kthread_stop(fs_info->cleaner_kthread);
1657fail_extent_root:
1658 free_extent_buffer(extent_root->node);
1659fail_tree_root:
1660 free_extent_buffer(tree_root->node);
1661fail_sys_array:
1662fail_sb_buffer:
1663 btrfs_stop_workers(&fs_info->fixup_workers);
1664 btrfs_stop_workers(&fs_info->workers);
1665 btrfs_stop_workers(&fs_info->endio_workers);
1666 btrfs_stop_workers(&fs_info->endio_write_workers);
1667 btrfs_stop_workers(&fs_info->submit_workers);
1668fail_iput:
1669 iput(fs_info->btree_inode);
1670fail:
1671 btrfs_close_devices(fs_info->fs_devices);
1672 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1673
1674 kfree(extent_root);
1675 kfree(tree_root);
1676#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1677 bdi_destroy(&fs_info->bdi);
1678#endif
1679 kfree(fs_info);
1680 return ERR_PTR(err);
1681}
1682
1683static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1684{
1685 char b[BDEVNAME_SIZE];
1686
1687 if (uptodate) {
1688 set_buffer_uptodate(bh);
1689 } else {
1690 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1691 printk(KERN_WARNING "lost page write due to "
1692 "I/O error on %s\n",
1693 bdevname(bh->b_bdev, b));
1694 }
1695 /* note, we dont' set_buffer_write_io_error because we have
1696 * our own ways of dealing with the IO errors
1697 */
1698 clear_buffer_uptodate(bh);
1699 }
1700 unlock_buffer(bh);
1701 put_bh(bh);
1702}
1703
1704int write_all_supers(struct btrfs_root *root)
1705{
1706 struct list_head *cur;
1707 struct list_head *head = &root->fs_info->fs_devices->devices;
1708 struct btrfs_device *dev;
1709 struct btrfs_super_block *sb;
1710 struct btrfs_dev_item *dev_item;
1711 struct buffer_head *bh;
1712 int ret;
1713 int do_barriers;
1714 int max_errors;
1715 int total_errors = 0;
1716 u32 crc;
1717 u64 flags;
1718
1719 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1720 do_barriers = !btrfs_test_opt(root, NOBARRIER);
1721
1722 sb = &root->fs_info->super_for_commit;
1723 dev_item = &sb->dev_item;
1724 list_for_each(cur, head) {
1725 dev = list_entry(cur, struct btrfs_device, dev_list);
1726 if (!dev->bdev) {
1727 total_errors++;
1728 continue;
1729 }
1730 if (!dev->in_fs_metadata)
1731 continue;
1732
1733 btrfs_set_stack_device_type(dev_item, dev->type);
1734 btrfs_set_stack_device_id(dev_item, dev->devid);
1735 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1736 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1737 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1738 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1739 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1740 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1741 flags = btrfs_super_flags(sb);
1742 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1743
1744
1745 crc = ~(u32)0;
1746 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1747 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1748 btrfs_csum_final(crc, sb->csum);
1749
1750 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1751 BTRFS_SUPER_INFO_SIZE);
1752
1753 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1754 dev->pending_io = bh;
1755
1756 get_bh(bh);
1757 set_buffer_uptodate(bh);
1758 lock_buffer(bh);
1759 bh->b_end_io = btrfs_end_buffer_write_sync;
1760
1761 if (do_barriers && dev->barriers) {
1762 ret = submit_bh(WRITE_BARRIER, bh);
1763 if (ret == -EOPNOTSUPP) {
1764 printk("btrfs: disabling barriers on dev %s\n",
1765 dev->name);
1766 set_buffer_uptodate(bh);
1767 dev->barriers = 0;
1768 get_bh(bh);
1769 lock_buffer(bh);
1770 ret = submit_bh(WRITE, bh);
1771 }
1772 } else {
1773 ret = submit_bh(WRITE, bh);
1774 }
1775 if (ret)
1776 total_errors++;
1777 }
1778 if (total_errors > max_errors) {
1779 printk("btrfs: %d errors while writing supers\n", total_errors);
1780 BUG();
1781 }
1782 total_errors = 0;
1783
1784 list_for_each(cur, head) {
1785 dev = list_entry(cur, struct btrfs_device, dev_list);
1786 if (!dev->bdev)
1787 continue;
1788 if (!dev->in_fs_metadata)
1789 continue;
1790
1791 BUG_ON(!dev->pending_io);
1792 bh = dev->pending_io;
1793 wait_on_buffer(bh);
1794 if (!buffer_uptodate(dev->pending_io)) {
1795 if (do_barriers && dev->barriers) {
1796 printk("btrfs: disabling barriers on dev %s\n",
1797 dev->name);
1798 set_buffer_uptodate(bh);
1799 get_bh(bh);
1800 lock_buffer(bh);
1801 dev->barriers = 0;
1802 ret = submit_bh(WRITE, bh);
1803 BUG_ON(ret);
1804 wait_on_buffer(bh);
1805 if (!buffer_uptodate(bh))
1806 total_errors++;
1807 } else {
1808 total_errors++;
1809 }
1810
1811 }
1812 dev->pending_io = NULL;
1813 brelse(bh);
1814 }
1815 if (total_errors > max_errors) {
1816 printk("btrfs: %d errors while writing supers\n", total_errors);
1817 BUG();
1818 }
1819 return 0;
1820}
1821
1822int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1823 *root)
1824{
1825 int ret;
1826
1827 ret = write_all_supers(root);
1828 return ret;
1829}
1830
1831int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1832{
1833 radix_tree_delete(&fs_info->fs_roots_radix,
1834 (unsigned long)root->root_key.objectid);
1835 if (root->in_sysfs)
1836 btrfs_sysfs_del_root(root);
1837 if (root->inode)
1838 iput(root->inode);
1839 if (root->node)
1840 free_extent_buffer(root->node);
1841 if (root->commit_root)
1842 free_extent_buffer(root->commit_root);
1843 if (root->name)
1844 kfree(root->name);
1845 kfree(root);
1846 return 0;
1847}
1848
1849static int del_fs_roots(struct btrfs_fs_info *fs_info)
1850{
1851 int ret;
1852 struct btrfs_root *gang[8];
1853 int i;
1854
1855 while(1) {
1856 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1857 (void **)gang, 0,
1858 ARRAY_SIZE(gang));
1859 if (!ret)
1860 break;
1861 for (i = 0; i < ret; i++)
1862 btrfs_free_fs_root(fs_info, gang[i]);
1863 }
1864 return 0;
1865}
1866
1867int close_ctree(struct btrfs_root *root)
1868{
1869 int ret;
1870 struct btrfs_trans_handle *trans;
1871 struct btrfs_fs_info *fs_info = root->fs_info;
1872
1873 fs_info->closing = 1;
1874 smp_mb();
1875
1876 kthread_stop(root->fs_info->transaction_kthread);
1877 kthread_stop(root->fs_info->cleaner_kthread);
1878
1879 btrfs_clean_old_snapshots(root);
1880 trans = btrfs_start_transaction(root, 1);
1881 ret = btrfs_commit_transaction(trans, root);
1882 /* run commit again to drop the original snapshot */
1883 trans = btrfs_start_transaction(root, 1);
1884 btrfs_commit_transaction(trans, root);
1885 ret = btrfs_write_and_wait_transaction(NULL, root);
1886 BUG_ON(ret);
1887
1888 write_ctree_super(NULL, root);
1889
1890 if (fs_info->delalloc_bytes) {
1891 printk("btrfs: at unmount delalloc count %Lu\n",
1892 fs_info->delalloc_bytes);
1893 }
1894 if (fs_info->total_ref_cache_size) {
1895 printk("btrfs: at umount reference cache size %Lu\n",
1896 fs_info->total_ref_cache_size);
1897 }
1898
1899 if (fs_info->extent_root->node)
1900 free_extent_buffer(fs_info->extent_root->node);
1901
1902 if (fs_info->tree_root->node)
1903 free_extent_buffer(fs_info->tree_root->node);
1904
1905 if (root->fs_info->chunk_root->node);
1906 free_extent_buffer(root->fs_info->chunk_root->node);
1907
1908 if (root->fs_info->dev_root->node);
1909 free_extent_buffer(root->fs_info->dev_root->node);
1910
1911 btrfs_free_block_groups(root->fs_info);
1912 fs_info->closing = 2;
1913 del_fs_roots(fs_info);
1914
1915 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1916
1917 truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1918
1919 btrfs_stop_workers(&fs_info->fixup_workers);
1920 btrfs_stop_workers(&fs_info->workers);
1921 btrfs_stop_workers(&fs_info->endio_workers);
1922 btrfs_stop_workers(&fs_info->endio_write_workers);
1923 btrfs_stop_workers(&fs_info->submit_workers);
1924
1925 iput(fs_info->btree_inode);
1926#if 0
1927 while(!list_empty(&fs_info->hashers)) {
1928 struct btrfs_hasher *hasher;
1929 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1930 hashers);
1931 list_del(&hasher->hashers);
1932 crypto_free_hash(&fs_info->hash_tfm);
1933 kfree(hasher);
1934 }
1935#endif
1936 btrfs_close_devices(fs_info->fs_devices);
1937 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1938
1939#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1940 bdi_destroy(&fs_info->bdi);
1941#endif
1942
1943 kfree(fs_info->extent_root);
1944 kfree(fs_info->tree_root);
1945 kfree(fs_info->chunk_root);
1946 kfree(fs_info->dev_root);
1947 return 0;
1948}
1949
1950int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1951{
1952 int ret;
1953 struct inode *btree_inode = buf->first_page->mapping->host;
1954
1955 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1956 if (!ret)
1957 return ret;
1958
1959 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1960 parent_transid);
1961 return !ret;
1962}
1963
1964int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1965{
1966 struct inode *btree_inode = buf->first_page->mapping->host;
1967 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1968 buf);
1969}
1970
1971void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1972{
1973 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1974 u64 transid = btrfs_header_generation(buf);
1975 struct inode *btree_inode = root->fs_info->btree_inode;
1976
1977 WARN_ON(!btrfs_tree_locked(buf));
1978 if (transid != root->fs_info->generation) {
1979 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1980 (unsigned long long)buf->start,
1981 transid, root->fs_info->generation);
1982 WARN_ON(1);
1983 }
1984 set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1985}
1986
1987void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1988{
1989 /*
1990 * looks as though older kernels can get into trouble with
1991 * this code, they end up stuck in balance_dirty_pages forever
1992 */
1993 struct extent_io_tree *tree;
1994 u64 num_dirty;
1995 u64 start = 0;
1996 unsigned long thresh = 96 * 1024 * 1024;
1997 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1998
1999 if (current_is_pdflush() || current->flags & PF_MEMALLOC)
2000 return;
2001
2002 num_dirty = count_range_bits(tree, &start, (u64)-1,
2003 thresh, EXTENT_DIRTY);
2004 if (num_dirty > thresh) {
2005 balance_dirty_pages_ratelimited_nr(
2006 root->fs_info->btree_inode->i_mapping, 1);
2007 }
2008 return;
2009}
2010
2011int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2012{
2013 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2014 int ret;
2015 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2016 if (ret == 0) {
2017 buf->flags |= EXTENT_UPTODATE;
2018 }
2019 return ret;
2020}
2021
2022int btree_lock_page_hook(struct page *page)
2023{
2024 struct inode *inode = page->mapping->host;
2025 struct btrfs_root *root = BTRFS_I(inode)->root;
2026 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2027 struct extent_buffer *eb;
2028 unsigned long len;
2029 u64 bytenr = page_offset(page);
2030
2031 if (page->private == EXTENT_PAGE_PRIVATE)
2032 goto out;
2033
2034 len = page->private >> 2;
2035 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2036 if (!eb)
2037 goto out;
2038
2039 btrfs_tree_lock(eb);
2040 spin_lock(&root->fs_info->hash_lock);
2041 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2042 spin_unlock(&root->fs_info->hash_lock);
2043 btrfs_tree_unlock(eb);
2044 free_extent_buffer(eb);
2045out:
2046 lock_page(page);
2047 return 0;
2048}
2049
2050static struct extent_io_ops btree_extent_io_ops = {
2051 .write_cache_pages_lock_hook = btree_lock_page_hook,
2052 .readpage_end_io_hook = btree_readpage_end_io_hook,
2053 .submit_bio_hook = btree_submit_bio_hook,
2054 /* note we're sharing with inode.c for the merge bio hook */
2055 .merge_bio_hook = btrfs_merge_bio_hook,
2056};
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-04 02:24:54 -0400