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move wm8400-regulator's probe function to .devinit.text
[linux-2.6/sactl.git] / fs / btrfs / disk-io.c
blob81a313874ae577aa51370459a0e98c8e26c53c46
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>
27 #include <linux/workqueue.h>
28 #include <linux/kthread.h>
29 #include <linux/freezer.h>
30 #include "compat.h"
31 #include "crc32c.h"
32 #include "ctree.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "btrfs_inode.h"
36 #include "volumes.h"
37 #include "print-tree.h"
38 #include "async-thread.h"
39 #include "locking.h"
40 #include "ref-cache.h"
41 #include "tree-log.h"
42
43 static struct extent_io_ops btree_extent_io_ops;
44 static void end_workqueue_fn(struct btrfs_work *work);
45
46 /*
47 * end_io_wq structs are used to do processing in task context when an IO is
48 * complete. This is used during reads to verify checksums, and it is used
49 * by writes to insert metadata for new file extents after IO is complete.
50 */
51 struct end_io_wq {
52 struct bio *bio;
53 bio_end_io_t *end_io;
54 void *private;
55 struct btrfs_fs_info *info;
56 int error;
57 int metadata;
58 struct list_head list;
59 struct btrfs_work work;
60 };
61
62 /*
63 * async submit bios are used to offload expensive checksumming
64 * onto the worker threads. They checksum file and metadata bios
65 * just before they are sent down the IO stack.
66 */
67 struct async_submit_bio {
68 struct inode *inode;
69 struct bio *bio;
70 struct list_head list;
71 extent_submit_bio_hook_t *submit_bio_start;
72 extent_submit_bio_hook_t *submit_bio_done;
73 int rw;
74 int mirror_num;
75 unsigned long bio_flags;
76 struct btrfs_work work;
77 };
78
79 /*
80 * extents on the btree inode are pretty simple, there's one extent
81 * that covers the entire device
82 */
83 static struct extent_map *btree_get_extent(struct inode *inode,
84 struct page *page, 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_len = (u64)-1;
109 em->block_start = 0;
110 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
111
112 spin_lock(&em_tree->lock);
113 ret = add_extent_mapping(em_tree, em);
114 if (ret == -EEXIST) {
115 u64 failed_start = em->start;
116 u64 failed_len = em->len;
117
118 free_extent_map(em);
119 em = lookup_extent_mapping(em_tree, start, len);
120 if (em) {
121 ret = 0;
122 } else {
123 em = lookup_extent_mapping(em_tree, failed_start,
124 failed_len);
125 ret = -EIO;
126 }
127 } else if (ret) {
128 free_extent_map(em);
129 em = NULL;
130 }
131 spin_unlock(&em_tree->lock);
132
133 if (ret)
134 em = ERR_PTR(ret);
135 out:
136 return em;
137 }
138
139 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
140 {
141 return btrfs_crc32c(seed, data, len);
142 }
143
144 void btrfs_csum_final(u32 crc, char *result)
145 {
146 *(__le32 *)result = ~cpu_to_le32(crc);
147 }
148
149 /*
150 * compute the csum for a btree block, and either verify it or write it
151 * into the csum field of the block.
152 */
153 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
154 int verify)
155 {
156 u16 csum_size =
157 btrfs_super_csum_size(&root->fs_info->super_copy);
158 char *result = NULL;
159 unsigned long len;
160 unsigned long cur_len;
161 unsigned long offset = BTRFS_CSUM_SIZE;
162 char *map_token = NULL;
163 char *kaddr;
164 unsigned long map_start;
165 unsigned long map_len;
166 int err;
167 u32 crc = ~(u32)0;
168 unsigned long inline_result;
169
170 len = buf->len - offset;
171 while (len > 0) {
172 err = map_private_extent_buffer(buf, offset, 32,
173 &map_token, &kaddr,
174 &map_start, &map_len, KM_USER0);
175 if (err)
176 return 1;
177 cur_len = min(len, map_len - (offset - map_start));
178 crc = btrfs_csum_data(root, kaddr + offset - map_start,
179 crc, cur_len);
180 len -= cur_len;
181 offset += cur_len;
182 unmap_extent_buffer(buf, map_token, KM_USER0);
183 }
184 if (csum_size > sizeof(inline_result)) {
185 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
186 if (!result)
187 return 1;
188 } else {
189 result = (char *)&inline_result;
190 }
191
192 btrfs_csum_final(crc, result);
193
194 if (verify) {
195 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
196 u32 val;
197 u32 found = 0;
198 memcpy(&found, result, csum_size);
199
200 read_extent_buffer(buf, &val, 0, csum_size);
201 printk(KERN_INFO "btrfs: %s checksum verify failed "
202 "on %llu wanted %X found %X level %d\n",
203 root->fs_info->sb->s_id,
204 buf->start, val, found, btrfs_header_level(buf));
205 if (result != (char *)&inline_result)
206 kfree(result);
207 return 1;
208 }
209 } else {
210 write_extent_buffer(buf, result, 0, csum_size);
211 }
212 if (result != (char *)&inline_result)
213 kfree(result);
214 return 0;
215 }
216
217 /*
218 * we can't consider a given block up to date unless the transid of the
219 * block matches the transid in the parent node's pointer. This is how we
220 * detect blocks that either didn't get written at all or got written
221 * in the wrong place.
222 */
223 static int verify_parent_transid(struct extent_io_tree *io_tree,
224 struct extent_buffer *eb, u64 parent_transid)
225 {
226 int ret;
227
228 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
229 return 0;
230
231 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
232 if (extent_buffer_uptodate(io_tree, eb) &&
233 btrfs_header_generation(eb) == parent_transid) {
234 ret = 0;
235 goto out;
236 }
237 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
238 (unsigned long long)eb->start,
239 (unsigned long long)parent_transid,
240 (unsigned long long)btrfs_header_generation(eb));
241 ret = 1;
242 clear_extent_buffer_uptodate(io_tree, eb);
243 out:
244 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
245 GFP_NOFS);
246 return ret;
247 }
248
249 /*
250 * helper to read a given tree block, doing retries as required when
251 * the checksums don't match and we have alternate mirrors to try.
252 */
253 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
254 struct extent_buffer *eb,
255 u64 start, u64 parent_transid)
256 {
257 struct extent_io_tree *io_tree;
258 int ret;
259 int num_copies = 0;
260 int mirror_num = 0;
261
262 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
263 while (1) {
264 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
265 btree_get_extent, mirror_num);
266 if (!ret &&
267 !verify_parent_transid(io_tree, eb, parent_transid))
268 return ret;
269
270 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
271 eb->start, eb->len);
272 if (num_copies == 1)
273 return ret;
274
275 mirror_num++;
276 if (mirror_num > num_copies)
277 return ret;
278 }
279 return -EIO;
280 }
281
282 /*
283 * checksum a dirty tree block before IO. This has extra checks to make sure
284 * we only fill in the checksum field in the first page of a multi-page block
285 */
286
287 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
288 {
289 struct extent_io_tree *tree;
290 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
291 u64 found_start;
292 int found_level;
293 unsigned long len;
294 struct extent_buffer *eb;
295 int ret;
296
297 tree = &BTRFS_I(page->mapping->host)->io_tree;
298
299 if (page->private == EXTENT_PAGE_PRIVATE)
300 goto out;
301 if (!page->private)
302 goto out;
303 len = page->private >> 2;
304 WARN_ON(len == 0);
305
306 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
307 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
308 btrfs_header_generation(eb));
309 BUG_ON(ret);
310 found_start = btrfs_header_bytenr(eb);
311 if (found_start != start) {
312 WARN_ON(1);
313 goto err;
314 }
315 if (eb->first_page != page) {
316 WARN_ON(1);
317 goto err;
318 }
319 if (!PageUptodate(page)) {
320 WARN_ON(1);
321 goto err;
322 }
323 found_level = btrfs_header_level(eb);
324
325 csum_tree_block(root, eb, 0);
326 err:
327 free_extent_buffer(eb);
328 out:
329 return 0;
330 }
331
332 static int check_tree_block_fsid(struct btrfs_root *root,
333 struct extent_buffer *eb)
334 {
335 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
336 u8 fsid[BTRFS_UUID_SIZE];
337 int ret = 1;
338
339 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
340 BTRFS_FSID_SIZE);
341 while (fs_devices) {
342 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
343 ret = 0;
344 break;
345 }
346 fs_devices = fs_devices->seed;
347 }
348 return ret;
349 }
350
351 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
352 struct extent_state *state)
353 {
354 struct extent_io_tree *tree;
355 u64 found_start;
356 int found_level;
357 unsigned long len;
358 struct extent_buffer *eb;
359 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
360 int ret = 0;
361
362 tree = &BTRFS_I(page->mapping->host)->io_tree;
363 if (page->private == EXTENT_PAGE_PRIVATE)
364 goto out;
365 if (!page->private)
366 goto out;
367
368 len = page->private >> 2;
369 WARN_ON(len == 0);
370
371 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
372
373 found_start = btrfs_header_bytenr(eb);
374 if (found_start != start) {
375 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n",
376 (unsigned long long)found_start,
377 (unsigned long long)eb->start);
378 ret = -EIO;
379 goto err;
380 }
381 if (eb->first_page != page) {
382 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
383 eb->first_page->index, page->index);
384 WARN_ON(1);
385 ret = -EIO;
386 goto err;
387 }
388 if (check_tree_block_fsid(root, eb)) {
389 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
390 (unsigned long long)eb->start);
391 ret = -EIO;
392 goto err;
393 }
394 found_level = btrfs_header_level(eb);
395
396 ret = csum_tree_block(root, eb, 1);
397 if (ret)
398 ret = -EIO;
399
400 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
401 end = eb->start + end - 1;
402 err:
403 free_extent_buffer(eb);
404 out:
405 return ret;
406 }
407
408 static void end_workqueue_bio(struct bio *bio, int err)
409 {
410 struct end_io_wq *end_io_wq = bio->bi_private;
411 struct btrfs_fs_info *fs_info;
412
413 fs_info = end_io_wq->info;
414 end_io_wq->error = err;
415 end_io_wq->work.func = end_workqueue_fn;
416 end_io_wq->work.flags = 0;
417
418 if (bio->bi_rw & (1 << BIO_RW)) {
419 if (end_io_wq->metadata)
420 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
421 &end_io_wq->work);
422 else
423 btrfs_queue_worker(&fs_info->endio_write_workers,
424 &end_io_wq->work);
425 } else {
426 if (end_io_wq->metadata)
427 btrfs_queue_worker(&fs_info->endio_meta_workers,
428 &end_io_wq->work);
429 else
430 btrfs_queue_worker(&fs_info->endio_workers,
431 &end_io_wq->work);
432 }
433 }
434
435 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
436 int metadata)
437 {
438 struct end_io_wq *end_io_wq;
439 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
440 if (!end_io_wq)
441 return -ENOMEM;
442
443 end_io_wq->private = bio->bi_private;
444 end_io_wq->end_io = bio->bi_end_io;
445 end_io_wq->info = info;
446 end_io_wq->error = 0;
447 end_io_wq->bio = bio;
448 end_io_wq->metadata = metadata;
449
450 bio->bi_private = end_io_wq;
451 bio->bi_end_io = end_workqueue_bio;
452 return 0;
453 }
454
455 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
456 {
457 unsigned long limit = min_t(unsigned long,
458 info->workers.max_workers,
459 info->fs_devices->open_devices);
460 return 256 * limit;
461 }
462
463 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
464 {
465 return atomic_read(&info->nr_async_bios) >
466 btrfs_async_submit_limit(info);
467 }
468
469 static void run_one_async_start(struct btrfs_work *work)
470 {
471 struct btrfs_fs_info *fs_info;
472 struct async_submit_bio *async;
473
474 async = container_of(work, struct async_submit_bio, work);
475 fs_info = BTRFS_I(async->inode)->root->fs_info;
476 async->submit_bio_start(async->inode, async->rw, async->bio,
477 async->mirror_num, async->bio_flags);
478 }
479
480 static void run_one_async_done(struct btrfs_work *work)
481 {
482 struct btrfs_fs_info *fs_info;
483 struct async_submit_bio *async;
484 int limit;
485
486 async = container_of(work, struct async_submit_bio, work);
487 fs_info = BTRFS_I(async->inode)->root->fs_info;
488
489 limit = btrfs_async_submit_limit(fs_info);
490 limit = limit * 2 / 3;
491
492 atomic_dec(&fs_info->nr_async_submits);
493
494 if (atomic_read(&fs_info->nr_async_submits) < limit &&
495 waitqueue_active(&fs_info->async_submit_wait))
496 wake_up(&fs_info->async_submit_wait);
497
498 async->submit_bio_done(async->inode, async->rw, async->bio,
499 async->mirror_num, async->bio_flags);
500 }
501
502 static void run_one_async_free(struct btrfs_work *work)
503 {
504 struct async_submit_bio *async;
505
506 async = container_of(work, struct async_submit_bio, work);
507 kfree(async);
508 }
509
510 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
511 int rw, struct bio *bio, int mirror_num,
512 unsigned long bio_flags,
513 extent_submit_bio_hook_t *submit_bio_start,
514 extent_submit_bio_hook_t *submit_bio_done)
515 {
516 struct async_submit_bio *async;
517
518 async = kmalloc(sizeof(*async), GFP_NOFS);
519 if (!async)
520 return -ENOMEM;
521
522 async->inode = inode;
523 async->rw = rw;
524 async->bio = bio;
525 async->mirror_num = mirror_num;
526 async->submit_bio_start = submit_bio_start;
527 async->submit_bio_done = submit_bio_done;
528
529 async->work.func = run_one_async_start;
530 async->work.ordered_func = run_one_async_done;
531 async->work.ordered_free = run_one_async_free;
532
533 async->work.flags = 0;
534 async->bio_flags = bio_flags;
535
536 atomic_inc(&fs_info->nr_async_submits);
537 btrfs_queue_worker(&fs_info->workers, &async->work);
538 #if 0
539 int limit = btrfs_async_submit_limit(fs_info);
540 if (atomic_read(&fs_info->nr_async_submits) > limit) {
541 wait_event_timeout(fs_info->async_submit_wait,
542 (atomic_read(&fs_info->nr_async_submits) < limit),
543 HZ/10);
544
545 wait_event_timeout(fs_info->async_submit_wait,
546 (atomic_read(&fs_info->nr_async_bios) < limit),
547 HZ/10);
548 }
549 #endif
550 while (atomic_read(&fs_info->async_submit_draining) &&
551 atomic_read(&fs_info->nr_async_submits)) {
552 wait_event(fs_info->async_submit_wait,
553 (atomic_read(&fs_info->nr_async_submits) == 0));
554 }
555
556 return 0;
557 }
558
559 static int btree_csum_one_bio(struct bio *bio)
560 {
561 struct bio_vec *bvec = bio->bi_io_vec;
562 int bio_index = 0;
563 struct btrfs_root *root;
564
565 WARN_ON(bio->bi_vcnt <= 0);
566 while (bio_index < bio->bi_vcnt) {
567 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
568 csum_dirty_buffer(root, bvec->bv_page);
569 bio_index++;
570 bvec++;
571 }
572 return 0;
573 }
574
575 static int __btree_submit_bio_start(struct inode *inode, int rw,
576 struct bio *bio, int mirror_num,
577 unsigned long bio_flags)
578 {
579 /*
580 * when we're called for a write, we're already in the async
581 * submission context. Just jump into btrfs_map_bio
582 */
583 btree_csum_one_bio(bio);
584 return 0;
585 }
586
587 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
588 int mirror_num, unsigned long bio_flags)
589 {
590 /*
591 * when we're called for a write, we're already in the async
592 * submission context. Just jump into btrfs_map_bio
593 */
594 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
595 }
596
597 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
598 int mirror_num, unsigned long bio_flags)
599 {
600 int ret;
601
602 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
603 bio, 1);
604 BUG_ON(ret);
605
606 if (!(rw & (1 << BIO_RW))) {
607 /*
608 * called for a read, do the setup so that checksum validation
609 * can happen in the async kernel threads
610 */
611 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
612 mirror_num, 0);
613 }
614 /*
615 * kthread helpers are used to submit writes so that checksumming
616 * can happen in parallel across all CPUs
617 */
618 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
619 inode, rw, bio, mirror_num, 0,
620 __btree_submit_bio_start,
621 __btree_submit_bio_done);
622 }
623
624 static int btree_writepage(struct page *page, struct writeback_control *wbc)
625 {
626 struct extent_io_tree *tree;
627 tree = &BTRFS_I(page->mapping->host)->io_tree;
628
629 if (current->flags & PF_MEMALLOC) {
630 redirty_page_for_writepage(wbc, page);
631 unlock_page(page);
632 return 0;
633 }
634 return extent_write_full_page(tree, page, btree_get_extent, wbc);
635 }
636
637 static int btree_writepages(struct address_space *mapping,
638 struct writeback_control *wbc)
639 {
640 struct extent_io_tree *tree;
641 tree = &BTRFS_I(mapping->host)->io_tree;
642 if (wbc->sync_mode == WB_SYNC_NONE) {
643 u64 num_dirty;
644 u64 start = 0;
645 unsigned long thresh = 32 * 1024 * 1024;
646
647 if (wbc->for_kupdate)
648 return 0;
649
650 num_dirty = count_range_bits(tree, &start, (u64)-1,
651 thresh, EXTENT_DIRTY);
652 if (num_dirty < thresh)
653 return 0;
654 }
655 return extent_writepages(tree, mapping, btree_get_extent, wbc);
656 }
657
658 static int btree_readpage(struct file *file, struct page *page)
659 {
660 struct extent_io_tree *tree;
661 tree = &BTRFS_I(page->mapping->host)->io_tree;
662 return extent_read_full_page(tree, page, btree_get_extent);
663 }
664
665 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
666 {
667 struct extent_io_tree *tree;
668 struct extent_map_tree *map;
669 int ret;
670
671 if (PageWriteback(page) || PageDirty(page))
672 return 0;
673
674 tree = &BTRFS_I(page->mapping->host)->io_tree;
675 map = &BTRFS_I(page->mapping->host)->extent_tree;
676
677 ret = try_release_extent_state(map, tree, page, gfp_flags);
678 if (!ret)
679 return 0;
680
681 ret = try_release_extent_buffer(tree, page);
682 if (ret == 1) {
683 ClearPagePrivate(page);
684 set_page_private(page, 0);
685 page_cache_release(page);
686 }
687
688 return ret;
689 }
690
691 static void btree_invalidatepage(struct page *page, unsigned long offset)
692 {
693 struct extent_io_tree *tree;
694 tree = &BTRFS_I(page->mapping->host)->io_tree;
695 extent_invalidatepage(tree, page, offset);
696 btree_releasepage(page, GFP_NOFS);
697 if (PagePrivate(page)) {
698 printk(KERN_WARNING "btrfs warning page private not zero "
699 "on page %llu\n", (unsigned long long)page_offset(page));
700 ClearPagePrivate(page);
701 set_page_private(page, 0);
702 page_cache_release(page);
703 }
704 }
705
706 #if 0
707 static int btree_writepage(struct page *page, struct writeback_control *wbc)
708 {
709 struct buffer_head *bh;
710 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
711 struct buffer_head *head;
712 if (!page_has_buffers(page)) {
713 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
714 (1 << BH_Dirty)|(1 << BH_Uptodate));
715 }
716 head = page_buffers(page);
717 bh = head;
718 do {
719 if (buffer_dirty(bh))
720 csum_tree_block(root, bh, 0);
721 bh = bh->b_this_page;
722 } while (bh != head);
723 return block_write_full_page(page, btree_get_block, wbc);
724 }
725 #endif
726
727 static struct address_space_operations btree_aops = {
728 .readpage = btree_readpage,
729 .writepage = btree_writepage,
730 .writepages = btree_writepages,
731 .releasepage = btree_releasepage,
732 .invalidatepage = btree_invalidatepage,
733 .sync_page = block_sync_page,
734 };
735
736 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
737 u64 parent_transid)
738 {
739 struct extent_buffer *buf = NULL;
740 struct inode *btree_inode = root->fs_info->btree_inode;
741 int ret = 0;
742
743 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
744 if (!buf)
745 return 0;
746 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
747 buf, 0, 0, btree_get_extent, 0);
748 free_extent_buffer(buf);
749 return ret;
750 }
751
752 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
753 u64 bytenr, u32 blocksize)
754 {
755 struct inode *btree_inode = root->fs_info->btree_inode;
756 struct extent_buffer *eb;
757 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
758 bytenr, blocksize, GFP_NOFS);
759 return eb;
760 }
761
762 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
763 u64 bytenr, u32 blocksize)
764 {
765 struct inode *btree_inode = root->fs_info->btree_inode;
766 struct extent_buffer *eb;
767
768 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
769 bytenr, blocksize, NULL, GFP_NOFS);
770 return eb;
771 }
772
773
774 int btrfs_write_tree_block(struct extent_buffer *buf)
775 {
776 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
777 buf->start + buf->len - 1, WB_SYNC_ALL);
778 }
779
780 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
781 {
782 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
783 buf->start, buf->start + buf->len - 1);
784 }
785
786 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
787 u32 blocksize, u64 parent_transid)
788 {
789 struct extent_buffer *buf = NULL;
790 struct inode *btree_inode = root->fs_info->btree_inode;
791 struct extent_io_tree *io_tree;
792 int ret;
793
794 io_tree = &BTRFS_I(btree_inode)->io_tree;
795
796 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
797 if (!buf)
798 return NULL;
799
800 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
801
802 if (ret == 0)
803 buf->flags |= EXTENT_UPTODATE;
804 else
805 WARN_ON(1);
806 return buf;
807
808 }
809
810 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
811 struct extent_buffer *buf)
812 {
813 struct inode *btree_inode = root->fs_info->btree_inode;
814 if (btrfs_header_generation(buf) ==
815 root->fs_info->running_transaction->transid) {
816 WARN_ON(!btrfs_tree_locked(buf));
817 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
818 buf);
819 }
820 return 0;
821 }
822
823 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
824 u32 stripesize, struct btrfs_root *root,
825 struct btrfs_fs_info *fs_info,
826 u64 objectid)
827 {
828 root->node = NULL;
829 root->commit_root = NULL;
830 root->ref_tree = NULL;
831 root->sectorsize = sectorsize;
832 root->nodesize = nodesize;
833 root->leafsize = leafsize;
834 root->stripesize = stripesize;
835 root->ref_cows = 0;
836 root->track_dirty = 0;
837
838 root->fs_info = fs_info;
839 root->objectid = objectid;
840 root->last_trans = 0;
841 root->highest_inode = 0;
842 root->last_inode_alloc = 0;
843 root->name = NULL;
844 root->in_sysfs = 0;
845
846 INIT_LIST_HEAD(&root->dirty_list);
847 INIT_LIST_HEAD(&root->orphan_list);
848 INIT_LIST_HEAD(&root->dead_list);
849 spin_lock_init(&root->node_lock);
850 spin_lock_init(&root->list_lock);
851 mutex_init(&root->objectid_mutex);
852 mutex_init(&root->log_mutex);
853 extent_io_tree_init(&root->dirty_log_pages,
854 fs_info->btree_inode->i_mapping, GFP_NOFS);
855
856 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
857 root->ref_tree = &root->ref_tree_struct;
858
859 memset(&root->root_key, 0, sizeof(root->root_key));
860 memset(&root->root_item, 0, sizeof(root->root_item));
861 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
862 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
863 root->defrag_trans_start = fs_info->generation;
864 init_completion(&root->kobj_unregister);
865 root->defrag_running = 0;
866 root->defrag_level = 0;
867 root->root_key.objectid = objectid;
868 root->anon_super.s_root = NULL;
869 root->anon_super.s_dev = 0;
870 INIT_LIST_HEAD(&root->anon_super.s_list);
871 INIT_LIST_HEAD(&root->anon_super.s_instances);
872 init_rwsem(&root->anon_super.s_umount);
873
874 return 0;
875 }
876
877 static int find_and_setup_root(struct btrfs_root *tree_root,
878 struct btrfs_fs_info *fs_info,
879 u64 objectid,
880 struct btrfs_root *root)
881 {
882 int ret;
883 u32 blocksize;
884 u64 generation;
885
886 __setup_root(tree_root->nodesize, tree_root->leafsize,
887 tree_root->sectorsize, tree_root->stripesize,
888 root, fs_info, objectid);
889 ret = btrfs_find_last_root(tree_root, objectid,
890 &root->root_item, &root->root_key);
891 BUG_ON(ret);
892
893 generation = btrfs_root_generation(&root->root_item);
894 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
895 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
896 blocksize, generation);
897 BUG_ON(!root->node);
898 return 0;
899 }
900
901 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
902 struct btrfs_fs_info *fs_info)
903 {
904 struct extent_buffer *eb;
905 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
906 u64 start = 0;
907 u64 end = 0;
908 int ret;
909
910 if (!log_root_tree)
911 return 0;
912
913 while (1) {
914 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
915 0, &start, &end, EXTENT_DIRTY);
916 if (ret)
917 break;
918
919 clear_extent_dirty(&log_root_tree->dirty_log_pages,
920 start, end, GFP_NOFS);
921 }
922 eb = fs_info->log_root_tree->node;
923
924 WARN_ON(btrfs_header_level(eb) != 0);
925 WARN_ON(btrfs_header_nritems(eb) != 0);
926
927 ret = btrfs_free_reserved_extent(fs_info->tree_root,
928 eb->start, eb->len);
929 BUG_ON(ret);
930
931 free_extent_buffer(eb);
932 kfree(fs_info->log_root_tree);
933 fs_info->log_root_tree = NULL;
934 return 0;
935 }
936
937 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
938 struct btrfs_fs_info *fs_info)
939 {
940 struct btrfs_root *root;
941 struct btrfs_root *tree_root = fs_info->tree_root;
942
943 root = kzalloc(sizeof(*root), GFP_NOFS);
944 if (!root)
945 return -ENOMEM;
946
947 __setup_root(tree_root->nodesize, tree_root->leafsize,
948 tree_root->sectorsize, tree_root->stripesize,
949 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
950
951 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
952 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
953 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
954 root->ref_cows = 0;
955
956 root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
957 0, BTRFS_TREE_LOG_OBJECTID,
958 trans->transid, 0, 0, 0);
959
960 btrfs_set_header_nritems(root->node, 0);
961 btrfs_set_header_level(root->node, 0);
962 btrfs_set_header_bytenr(root->node, root->node->start);
963 btrfs_set_header_generation(root->node, trans->transid);
964 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
965
966 write_extent_buffer(root->node, root->fs_info->fsid,
967 (unsigned long)btrfs_header_fsid(root->node),
968 BTRFS_FSID_SIZE);
969 btrfs_mark_buffer_dirty(root->node);
970 btrfs_tree_unlock(root->node);
971 fs_info->log_root_tree = root;
972 return 0;
973 }
974
975 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
976 struct btrfs_key *location)
977 {
978 struct btrfs_root *root;
979 struct btrfs_fs_info *fs_info = tree_root->fs_info;
980 struct btrfs_path *path;
981 struct extent_buffer *l;
982 u64 highest_inode;
983 u64 generation;
984 u32 blocksize;
985 int ret = 0;
986
987 root = kzalloc(sizeof(*root), GFP_NOFS);
988 if (!root)
989 return ERR_PTR(-ENOMEM);
990 if (location->offset == (u64)-1) {
991 ret = find_and_setup_root(tree_root, fs_info,
992 location->objectid, root);
993 if (ret) {
994 kfree(root);
995 return ERR_PTR(ret);
996 }
997 goto insert;
998 }
999
1000 __setup_root(tree_root->nodesize, tree_root->leafsize,
1001 tree_root->sectorsize, tree_root->stripesize,
1002 root, fs_info, location->objectid);
1003
1004 path = btrfs_alloc_path();
1005 BUG_ON(!path);
1006 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1007 if (ret != 0) {
1008 if (ret > 0)
1009 ret = -ENOENT;
1010 goto out;
1011 }
1012 l = path->nodes[0];
1013 read_extent_buffer(l, &root->root_item,
1014 btrfs_item_ptr_offset(l, path->slots[0]),
1015 sizeof(root->root_item));
1016 memcpy(&root->root_key, location, sizeof(*location));
1017 ret = 0;
1018 out:
1019 btrfs_release_path(root, path);
1020 btrfs_free_path(path);
1021 if (ret) {
1022 kfree(root);
1023 return ERR_PTR(ret);
1024 }
1025 generation = btrfs_root_generation(&root->root_item);
1026 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1027 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1028 blocksize, generation);
1029 BUG_ON(!root->node);
1030 insert:
1031 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1032 root->ref_cows = 1;
1033 ret = btrfs_find_highest_inode(root, &highest_inode);
1034 if (ret == 0) {
1035 root->highest_inode = highest_inode;
1036 root->last_inode_alloc = highest_inode;
1037 }
1038 }
1039 return root;
1040 }
1041
1042 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1043 u64 root_objectid)
1044 {
1045 struct btrfs_root *root;
1046
1047 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1048 return fs_info->tree_root;
1049 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1050 return fs_info->extent_root;
1051
1052 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1053 (unsigned long)root_objectid);
1054 return root;
1055 }
1056
1057 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1058 struct btrfs_key *location)
1059 {
1060 struct btrfs_root *root;
1061 int ret;
1062
1063 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1064 return fs_info->tree_root;
1065 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1066 return fs_info->extent_root;
1067 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1068 return fs_info->chunk_root;
1069 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1070 return fs_info->dev_root;
1071 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1072 return fs_info->csum_root;
1073
1074 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1075 (unsigned long)location->objectid);
1076 if (root)
1077 return root;
1078
1079 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1080 if (IS_ERR(root))
1081 return root;
1082
1083 set_anon_super(&root->anon_super, NULL);
1084
1085 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1086 (unsigned long)root->root_key.objectid,
1087 root);
1088 if (ret) {
1089 free_extent_buffer(root->node);
1090 kfree(root);
1091 return ERR_PTR(ret);
1092 }
1093 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1094 ret = btrfs_find_dead_roots(fs_info->tree_root,
1095 root->root_key.objectid, root);
1096 BUG_ON(ret);
1097 btrfs_orphan_cleanup(root);
1098 }
1099 return root;
1100 }
1101
1102 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1103 struct btrfs_key *location,
1104 const char *name, int namelen)
1105 {
1106 struct btrfs_root *root;
1107 int ret;
1108
1109 root = btrfs_read_fs_root_no_name(fs_info, location);
1110 if (!root)
1111 return NULL;
1112
1113 if (root->in_sysfs)
1114 return root;
1115
1116 ret = btrfs_set_root_name(root, name, namelen);
1117 if (ret) {
1118 free_extent_buffer(root->node);
1119 kfree(root);
1120 return ERR_PTR(ret);
1121 }
1122 #if 0
1123 ret = btrfs_sysfs_add_root(root);
1124 if (ret) {
1125 free_extent_buffer(root->node);
1126 kfree(root->name);
1127 kfree(root);
1128 return ERR_PTR(ret);
1129 }
1130 #endif
1131 root->in_sysfs = 1;
1132 return root;
1133 }
1134
1135 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1136 {
1137 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1138 int ret = 0;
1139 struct list_head *cur;
1140 struct btrfs_device *device;
1141 struct backing_dev_info *bdi;
1142 #if 0
1143 if ((bdi_bits & (1 << BDI_write_congested)) &&
1144 btrfs_congested_async(info, 0))
1145 return 1;
1146 #endif
1147 list_for_each(cur, &info->fs_devices->devices) {
1148 device = list_entry(cur, struct btrfs_device, dev_list);
1149 if (!device->bdev)
1150 continue;
1151 bdi = blk_get_backing_dev_info(device->bdev);
1152 if (bdi && bdi_congested(bdi, bdi_bits)) {
1153 ret = 1;
1154 break;
1155 }
1156 }
1157 return ret;
1158 }
1159
1160 /*
1161 * this unplugs every device on the box, and it is only used when page
1162 * is null
1163 */
1164 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1165 {
1166 struct list_head *cur;
1167 struct btrfs_device *device;
1168 struct btrfs_fs_info *info;
1169
1170 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1171 list_for_each(cur, &info->fs_devices->devices) {
1172 device = list_entry(cur, struct btrfs_device, dev_list);
1173 if (!device->bdev)
1174 continue;
1175
1176 bdi = blk_get_backing_dev_info(device->bdev);
1177 if (bdi->unplug_io_fn)
1178 bdi->unplug_io_fn(bdi, page);
1179 }
1180 }
1181
1182 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1183 {
1184 struct inode *inode;
1185 struct extent_map_tree *em_tree;
1186 struct extent_map *em;
1187 struct address_space *mapping;
1188 u64 offset;
1189
1190 /* the generic O_DIRECT read code does this */
1191 if (1 || !page) {
1192 __unplug_io_fn(bdi, page);
1193 return;
1194 }
1195
1196 /*
1197 * page->mapping may change at any time. Get a consistent copy
1198 * and use that for everything below
1199 */
1200 smp_mb();
1201 mapping = page->mapping;
1202 if (!mapping)
1203 return;
1204
1205 inode = mapping->host;
1206
1207 /*
1208 * don't do the expensive searching for a small number of
1209 * devices
1210 */
1211 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1212 __unplug_io_fn(bdi, page);
1213 return;
1214 }
1215
1216 offset = page_offset(page);
1217
1218 em_tree = &BTRFS_I(inode)->extent_tree;
1219 spin_lock(&em_tree->lock);
1220 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1221 spin_unlock(&em_tree->lock);
1222 if (!em) {
1223 __unplug_io_fn(bdi, page);
1224 return;
1225 }
1226
1227 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1228 free_extent_map(em);
1229 __unplug_io_fn(bdi, page);
1230 return;
1231 }
1232 offset = offset - em->start;
1233 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1234 em->block_start + offset, page);
1235 free_extent_map(em);
1236 }
1237
1238 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1239 {
1240 bdi_init(bdi);
1241 bdi->ra_pages = default_backing_dev_info.ra_pages;
1242 bdi->state = 0;
1243 bdi->capabilities = default_backing_dev_info.capabilities;
1244 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1245 bdi->unplug_io_data = info;
1246 bdi->congested_fn = btrfs_congested_fn;
1247 bdi->congested_data = info;
1248 return 0;
1249 }
1250
1251 static int bio_ready_for_csum(struct bio *bio)
1252 {
1253 u64 length = 0;
1254 u64 buf_len = 0;
1255 u64 start = 0;
1256 struct page *page;
1257 struct extent_io_tree *io_tree = NULL;
1258 struct btrfs_fs_info *info = NULL;
1259 struct bio_vec *bvec;
1260 int i;
1261 int ret;
1262
1263 bio_for_each_segment(bvec, bio, i) {
1264 page = bvec->bv_page;
1265 if (page->private == EXTENT_PAGE_PRIVATE) {
1266 length += bvec->bv_len;
1267 continue;
1268 }
1269 if (!page->private) {
1270 length += bvec->bv_len;
1271 continue;
1272 }
1273 length = bvec->bv_len;
1274 buf_len = page->private >> 2;
1275 start = page_offset(page) + bvec->bv_offset;
1276 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1277 info = BTRFS_I(page->mapping->host)->root->fs_info;
1278 }
1279 /* are we fully contained in this bio? */
1280 if (buf_len <= length)
1281 return 1;
1282
1283 ret = extent_range_uptodate(io_tree, start + length,
1284 start + buf_len - 1);
1285 if (ret == 1)
1286 return ret;
1287 return ret;
1288 }
1289
1290 /*
1291 * called by the kthread helper functions to finally call the bio end_io
1292 * functions. This is where read checksum verification actually happens
1293 */
1294 static void end_workqueue_fn(struct btrfs_work *work)
1295 {
1296 struct bio *bio;
1297 struct end_io_wq *end_io_wq;
1298 struct btrfs_fs_info *fs_info;
1299 int error;
1300
1301 end_io_wq = container_of(work, struct end_io_wq, work);
1302 bio = end_io_wq->bio;
1303 fs_info = end_io_wq->info;
1304
1305 /* metadata bio reads are special because the whole tree block must
1306 * be checksummed at once. This makes sure the entire block is in
1307 * ram and up to date before trying to verify things. For
1308 * blocksize <= pagesize, it is basically a noop
1309 */
1310 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1311 !bio_ready_for_csum(bio)) {
1312 btrfs_queue_worker(&fs_info->endio_meta_workers,
1313 &end_io_wq->work);
1314 return;
1315 }
1316 error = end_io_wq->error;
1317 bio->bi_private = end_io_wq->private;
1318 bio->bi_end_io = end_io_wq->end_io;
1319 kfree(end_io_wq);
1320 bio_endio(bio, error);
1321 }
1322
1323 static int cleaner_kthread(void *arg)
1324 {
1325 struct btrfs_root *root = arg;
1326
1327 do {
1328 smp_mb();
1329 if (root->fs_info->closing)
1330 break;
1331
1332 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1333 mutex_lock(&root->fs_info->cleaner_mutex);
1334 btrfs_clean_old_snapshots(root);
1335 mutex_unlock(&root->fs_info->cleaner_mutex);
1336
1337 if (freezing(current)) {
1338 refrigerator();
1339 } else {
1340 smp_mb();
1341 if (root->fs_info->closing)
1342 break;
1343 set_current_state(TASK_INTERRUPTIBLE);
1344 schedule();
1345 __set_current_state(TASK_RUNNING);
1346 }
1347 } while (!kthread_should_stop());
1348 return 0;
1349 }
1350
1351 static int transaction_kthread(void *arg)
1352 {
1353 struct btrfs_root *root = arg;
1354 struct btrfs_trans_handle *trans;
1355 struct btrfs_transaction *cur;
1356 unsigned long now;
1357 unsigned long delay;
1358 int ret;
1359
1360 do {
1361 smp_mb();
1362 if (root->fs_info->closing)
1363 break;
1364
1365 delay = HZ * 30;
1366 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1367 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1368
1369 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1370 printk(KERN_INFO "btrfs: total reference cache "
1371 "size %llu\n",
1372 root->fs_info->total_ref_cache_size);
1373 }
1374
1375 mutex_lock(&root->fs_info->trans_mutex);
1376 cur = root->fs_info->running_transaction;
1377 if (!cur) {
1378 mutex_unlock(&root->fs_info->trans_mutex);
1379 goto sleep;
1380 }
1381
1382 now = get_seconds();
1383 if (now < cur->start_time || now - cur->start_time < 30) {
1384 mutex_unlock(&root->fs_info->trans_mutex);
1385 delay = HZ * 5;
1386 goto sleep;
1387 }
1388 mutex_unlock(&root->fs_info->trans_mutex);
1389 trans = btrfs_start_transaction(root, 1);
1390 ret = btrfs_commit_transaction(trans, root);
1391 sleep:
1392 wake_up_process(root->fs_info->cleaner_kthread);
1393 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1394
1395 if (freezing(current)) {
1396 refrigerator();
1397 } else {
1398 if (root->fs_info->closing)
1399 break;
1400 set_current_state(TASK_INTERRUPTIBLE);
1401 schedule_timeout(delay);
1402 __set_current_state(TASK_RUNNING);
1403 }
1404 } while (!kthread_should_stop());
1405 return 0;
1406 }
1407
1408 struct btrfs_root *open_ctree(struct super_block *sb,
1409 struct btrfs_fs_devices *fs_devices,
1410 char *options)
1411 {
1412 u32 sectorsize;
1413 u32 nodesize;
1414 u32 leafsize;
1415 u32 blocksize;
1416 u32 stripesize;
1417 u64 generation;
1418 u64 features;
1419 struct btrfs_key location;
1420 struct buffer_head *bh;
1421 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1422 GFP_NOFS);
1423 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1424 GFP_NOFS);
1425 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1426 GFP_NOFS);
1427 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1428 GFP_NOFS);
1429 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1430 GFP_NOFS);
1431 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1432 GFP_NOFS);
1433 struct btrfs_root *log_tree_root;
1434
1435 int ret;
1436 int err = -EINVAL;
1437
1438 struct btrfs_super_block *disk_super;
1439
1440 if (!extent_root || !tree_root || !fs_info ||
1441 !chunk_root || !dev_root || !csum_root) {
1442 err = -ENOMEM;
1443 goto fail;
1444 }
1445 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1446 INIT_LIST_HEAD(&fs_info->trans_list);
1447 INIT_LIST_HEAD(&fs_info->dead_roots);
1448 INIT_LIST_HEAD(&fs_info->hashers);
1449 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1450 spin_lock_init(&fs_info->hash_lock);
1451 spin_lock_init(&fs_info->delalloc_lock);
1452 spin_lock_init(&fs_info->new_trans_lock);
1453 spin_lock_init(&fs_info->ref_cache_lock);
1454
1455 init_completion(&fs_info->kobj_unregister);
1456 fs_info->tree_root = tree_root;
1457 fs_info->extent_root = extent_root;
1458 fs_info->csum_root = csum_root;
1459 fs_info->chunk_root = chunk_root;
1460 fs_info->dev_root = dev_root;
1461 fs_info->fs_devices = fs_devices;
1462 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1463 INIT_LIST_HEAD(&fs_info->space_info);
1464 btrfs_mapping_init(&fs_info->mapping_tree);
1465 atomic_set(&fs_info->nr_async_submits, 0);
1466 atomic_set(&fs_info->async_delalloc_pages, 0);
1467 atomic_set(&fs_info->async_submit_draining, 0);
1468 atomic_set(&fs_info->nr_async_bios, 0);
1469 atomic_set(&fs_info->throttles, 0);
1470 atomic_set(&fs_info->throttle_gen, 0);
1471 fs_info->sb = sb;
1472 fs_info->max_extent = (u64)-1;
1473 fs_info->max_inline = 8192 * 1024;
1474 setup_bdi(fs_info, &fs_info->bdi);
1475 fs_info->btree_inode = new_inode(sb);
1476 fs_info->btree_inode->i_ino = 1;
1477 fs_info->btree_inode->i_nlink = 1;
1478
1479 fs_info->thread_pool_size = min_t(unsigned long,
1480 num_online_cpus() + 2, 8);
1481
1482 INIT_LIST_HEAD(&fs_info->ordered_extents);
1483 spin_lock_init(&fs_info->ordered_extent_lock);
1484
1485 sb->s_blocksize = 4096;
1486 sb->s_blocksize_bits = blksize_bits(4096);
1487
1488 /*
1489 * we set the i_size on the btree inode to the max possible int.
1490 * the real end of the address space is determined by all of
1491 * the devices in the system
1492 */
1493 fs_info->btree_inode->i_size = OFFSET_MAX;
1494 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1495 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1496
1497 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1498 fs_info->btree_inode->i_mapping,
1499 GFP_NOFS);
1500 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1501 GFP_NOFS);
1502
1503 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1504
1505 spin_lock_init(&fs_info->block_group_cache_lock);
1506 fs_info->block_group_cache_tree.rb_node = NULL;
1507
1508 extent_io_tree_init(&fs_info->pinned_extents,
1509 fs_info->btree_inode->i_mapping, GFP_NOFS);
1510 extent_io_tree_init(&fs_info->pending_del,
1511 fs_info->btree_inode->i_mapping, GFP_NOFS);
1512 extent_io_tree_init(&fs_info->extent_ins,
1513 fs_info->btree_inode->i_mapping, GFP_NOFS);
1514 fs_info->do_barriers = 1;
1515
1516 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1517 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1518 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1519
1520 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1521 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1522 sizeof(struct btrfs_key));
1523 insert_inode_hash(fs_info->btree_inode);
1524
1525 mutex_init(&fs_info->trans_mutex);
1526 mutex_init(&fs_info->tree_log_mutex);
1527 mutex_init(&fs_info->drop_mutex);
1528 mutex_init(&fs_info->extent_ins_mutex);
1529 mutex_init(&fs_info->pinned_mutex);
1530 mutex_init(&fs_info->chunk_mutex);
1531 mutex_init(&fs_info->transaction_kthread_mutex);
1532 mutex_init(&fs_info->cleaner_mutex);
1533 mutex_init(&fs_info->volume_mutex);
1534 mutex_init(&fs_info->tree_reloc_mutex);
1535 init_waitqueue_head(&fs_info->transaction_throttle);
1536 init_waitqueue_head(&fs_info->transaction_wait);
1537 init_waitqueue_head(&fs_info->async_submit_wait);
1538 init_waitqueue_head(&fs_info->tree_log_wait);
1539 atomic_set(&fs_info->tree_log_commit, 0);
1540 atomic_set(&fs_info->tree_log_writers, 0);
1541 fs_info->tree_log_transid = 0;
1542
1543 __setup_root(4096, 4096, 4096, 4096, tree_root,
1544 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1545
1546
1547 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1548 if (!bh)
1549 goto fail_iput;
1550
1551 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1552 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1553 sizeof(fs_info->super_for_commit));
1554 brelse(bh);
1555
1556 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1557
1558 disk_super = &fs_info->super_copy;
1559 if (!btrfs_super_root(disk_super))
1560 goto fail_iput;
1561
1562 ret = btrfs_parse_options(tree_root, options);
1563 if (ret) {
1564 err = ret;
1565 goto fail_iput;
1566 }
1567
1568 features = btrfs_super_incompat_flags(disk_super) &
1569 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1570 if (features) {
1571 printk(KERN_ERR "BTRFS: couldn't mount because of "
1572 "unsupported optional features (%Lx).\n",
1573 features);
1574 err = -EINVAL;
1575 goto fail_iput;
1576 }
1577
1578 features = btrfs_super_compat_ro_flags(disk_super) &
1579 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1580 if (!(sb->s_flags & MS_RDONLY) && features) {
1581 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1582 "unsupported option features (%Lx).\n",
1583 features);
1584 err = -EINVAL;
1585 goto fail_iput;
1586 }
1587
1588 /*
1589 * we need to start all the end_io workers up front because the
1590 * queue work function gets called at interrupt time, and so it
1591 * cannot dynamically grow.
1592 */
1593 btrfs_init_workers(&fs_info->workers, "worker",
1594 fs_info->thread_pool_size);
1595
1596 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1597 fs_info->thread_pool_size);
1598
1599 btrfs_init_workers(&fs_info->submit_workers, "submit",
1600 min_t(u64, fs_devices->num_devices,
1601 fs_info->thread_pool_size));
1602
1603 /* a higher idle thresh on the submit workers makes it much more
1604 * likely that bios will be send down in a sane order to the
1605 * devices
1606 */
1607 fs_info->submit_workers.idle_thresh = 64;
1608
1609 fs_info->workers.idle_thresh = 16;
1610 fs_info->workers.ordered = 1;
1611
1612 fs_info->delalloc_workers.idle_thresh = 2;
1613 fs_info->delalloc_workers.ordered = 1;
1614
1615 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1616 btrfs_init_workers(&fs_info->endio_workers, "endio",
1617 fs_info->thread_pool_size);
1618 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1619 fs_info->thread_pool_size);
1620 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1621 "endio-meta-write", fs_info->thread_pool_size);
1622 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1623 fs_info->thread_pool_size);
1624
1625 /*
1626 * endios are largely parallel and should have a very
1627 * low idle thresh
1628 */
1629 fs_info->endio_workers.idle_thresh = 4;
1630 fs_info->endio_write_workers.idle_thresh = 64;
1631 fs_info->endio_meta_write_workers.idle_thresh = 64;
1632
1633 btrfs_start_workers(&fs_info->workers, 1);
1634 btrfs_start_workers(&fs_info->submit_workers, 1);
1635 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1636 btrfs_start_workers(&fs_info->fixup_workers, 1);
1637 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1638 btrfs_start_workers(&fs_info->endio_meta_workers,
1639 fs_info->thread_pool_size);
1640 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1641 fs_info->thread_pool_size);
1642 btrfs_start_workers(&fs_info->endio_write_workers,
1643 fs_info->thread_pool_size);
1644
1645 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1646 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1647 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1648
1649 nodesize = btrfs_super_nodesize(disk_super);
1650 leafsize = btrfs_super_leafsize(disk_super);
1651 sectorsize = btrfs_super_sectorsize(disk_super);
1652 stripesize = btrfs_super_stripesize(disk_super);
1653 tree_root->nodesize = nodesize;
1654 tree_root->leafsize = leafsize;
1655 tree_root->sectorsize = sectorsize;
1656 tree_root->stripesize = stripesize;
1657
1658 sb->s_blocksize = sectorsize;
1659 sb->s_blocksize_bits = blksize_bits(sectorsize);
1660
1661 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1662 sizeof(disk_super->magic))) {
1663 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1664 goto fail_sb_buffer;
1665 }
1666
1667 mutex_lock(&fs_info->chunk_mutex);
1668 ret = btrfs_read_sys_array(tree_root);
1669 mutex_unlock(&fs_info->chunk_mutex);
1670 if (ret) {
1671 printk(KERN_WARNING "btrfs: failed to read the system "
1672 "array on %s\n", sb->s_id);
1673 goto fail_sys_array;
1674 }
1675
1676 blocksize = btrfs_level_size(tree_root,
1677 btrfs_super_chunk_root_level(disk_super));
1678 generation = btrfs_super_chunk_root_generation(disk_super);
1679
1680 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1681 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1682
1683 chunk_root->node = read_tree_block(chunk_root,
1684 btrfs_super_chunk_root(disk_super),
1685 blocksize, generation);
1686 BUG_ON(!chunk_root->node);
1687
1688 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1689 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1690 BTRFS_UUID_SIZE);
1691
1692 mutex_lock(&fs_info->chunk_mutex);
1693 ret = btrfs_read_chunk_tree(chunk_root);
1694 mutex_unlock(&fs_info->chunk_mutex);
1695 if (ret) {
1696 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1697 sb->s_id);
1698 goto fail_chunk_root;
1699 }
1700
1701 btrfs_close_extra_devices(fs_devices);
1702
1703 blocksize = btrfs_level_size(tree_root,
1704 btrfs_super_root_level(disk_super));
1705 generation = btrfs_super_generation(disk_super);
1706
1707 tree_root->node = read_tree_block(tree_root,
1708 btrfs_super_root(disk_super),
1709 blocksize, generation);
1710 if (!tree_root->node)
1711 goto fail_chunk_root;
1712
1713
1714 ret = find_and_setup_root(tree_root, fs_info,
1715 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1716 if (ret)
1717 goto fail_tree_root;
1718 extent_root->track_dirty = 1;
1719
1720 ret = find_and_setup_root(tree_root, fs_info,
1721 BTRFS_DEV_TREE_OBJECTID, dev_root);
1722 dev_root->track_dirty = 1;
1723
1724 if (ret)
1725 goto fail_extent_root;
1726
1727 ret = find_and_setup_root(tree_root, fs_info,
1728 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1729 if (ret)
1730 goto fail_extent_root;
1731
1732 csum_root->track_dirty = 1;
1733
1734 btrfs_read_block_groups(extent_root);
1735
1736 fs_info->generation = generation;
1737 fs_info->last_trans_committed = generation;
1738 fs_info->data_alloc_profile = (u64)-1;
1739 fs_info->metadata_alloc_profile = (u64)-1;
1740 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1741 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1742 "btrfs-cleaner");
1743 if (!fs_info->cleaner_kthread)
1744 goto fail_csum_root;
1745
1746 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1747 tree_root,
1748 "btrfs-transaction");
1749 if (!fs_info->transaction_kthread)
1750 goto fail_cleaner;
1751
1752 if (btrfs_super_log_root(disk_super) != 0) {
1753 u64 bytenr = btrfs_super_log_root(disk_super);
1754
1755 if (fs_devices->rw_devices == 0) {
1756 printk(KERN_WARNING "Btrfs log replay required "
1757 "on RO media\n");
1758 err = -EIO;
1759 goto fail_trans_kthread;
1760 }
1761 blocksize =
1762 btrfs_level_size(tree_root,
1763 btrfs_super_log_root_level(disk_super));
1764
1765 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1766 GFP_NOFS);
1767
1768 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1769 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1770
1771 log_tree_root->node = read_tree_block(tree_root, bytenr,
1772 blocksize,
1773 generation + 1);
1774 ret = btrfs_recover_log_trees(log_tree_root);
1775 BUG_ON(ret);
1776
1777 if (sb->s_flags & MS_RDONLY) {
1778 ret = btrfs_commit_super(tree_root);
1779 BUG_ON(ret);
1780 }
1781 }
1782
1783 if (!(sb->s_flags & MS_RDONLY)) {
1784 ret = btrfs_cleanup_reloc_trees(tree_root);
1785 BUG_ON(ret);
1786 }
1787
1788 location.objectid = BTRFS_FS_TREE_OBJECTID;
1789 location.type = BTRFS_ROOT_ITEM_KEY;
1790 location.offset = (u64)-1;
1791
1792 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1793 if (!fs_info->fs_root)
1794 goto fail_trans_kthread;
1795 return tree_root;
1796
1797 fail_trans_kthread:
1798 kthread_stop(fs_info->transaction_kthread);
1799 fail_cleaner:
1800 kthread_stop(fs_info->cleaner_kthread);
1801
1802 /*
1803 * make sure we're done with the btree inode before we stop our
1804 * kthreads
1805 */
1806 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1807 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1808
1809 fail_csum_root:
1810 free_extent_buffer(csum_root->node);
1811 fail_extent_root:
1812 free_extent_buffer(extent_root->node);
1813 fail_tree_root:
1814 free_extent_buffer(tree_root->node);
1815 fail_chunk_root:
1816 free_extent_buffer(chunk_root->node);
1817 fail_sys_array:
1818 free_extent_buffer(dev_root->node);
1819 fail_sb_buffer:
1820 btrfs_stop_workers(&fs_info->fixup_workers);
1821 btrfs_stop_workers(&fs_info->delalloc_workers);
1822 btrfs_stop_workers(&fs_info->workers);
1823 btrfs_stop_workers(&fs_info->endio_workers);
1824 btrfs_stop_workers(&fs_info->endio_meta_workers);
1825 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1826 btrfs_stop_workers(&fs_info->endio_write_workers);
1827 btrfs_stop_workers(&fs_info->submit_workers);
1828 fail_iput:
1829 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1830 iput(fs_info->btree_inode);
1831 fail:
1832 btrfs_close_devices(fs_info->fs_devices);
1833 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1834
1835 kfree(extent_root);
1836 kfree(tree_root);
1837 bdi_destroy(&fs_info->bdi);
1838 kfree(fs_info);
1839 kfree(chunk_root);
1840 kfree(dev_root);
1841 kfree(csum_root);
1842 return ERR_PTR(err);
1843 }
1844
1845 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1846 {
1847 char b[BDEVNAME_SIZE];
1848
1849 if (uptodate) {
1850 set_buffer_uptodate(bh);
1851 } else {
1852 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1853 printk(KERN_WARNING "lost page write due to "
1854 "I/O error on %s\n",
1855 bdevname(bh->b_bdev, b));
1856 }
1857 /* note, we dont' set_buffer_write_io_error because we have
1858 * our own ways of dealing with the IO errors
1859 */
1860 clear_buffer_uptodate(bh);
1861 }
1862 unlock_buffer(bh);
1863 put_bh(bh);
1864 }
1865
1866 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1867 {
1868 struct buffer_head *bh;
1869 struct buffer_head *latest = NULL;
1870 struct btrfs_super_block *super;
1871 int i;
1872 u64 transid = 0;
1873 u64 bytenr;
1874
1875 /* we would like to check all the supers, but that would make
1876 * a btrfs mount succeed after a mkfs from a different FS.
1877 * So, we need to add a special mount option to scan for
1878 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1879 */
1880 for (i = 0; i < 1; i++) {
1881 bytenr = btrfs_sb_offset(i);
1882 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1883 break;
1884 bh = __bread(bdev, bytenr / 4096, 4096);
1885 if (!bh)
1886 continue;
1887
1888 super = (struct btrfs_super_block *)bh->b_data;
1889 if (btrfs_super_bytenr(super) != bytenr ||
1890 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1891 sizeof(super->magic))) {
1892 brelse(bh);
1893 continue;
1894 }
1895
1896 if (!latest || btrfs_super_generation(super) > transid) {
1897 brelse(latest);
1898 latest = bh;
1899 transid = btrfs_super_generation(super);
1900 } else {
1901 brelse(bh);
1902 }
1903 }
1904 return latest;
1905 }
1906
1907 static int write_dev_supers(struct btrfs_device *device,
1908 struct btrfs_super_block *sb,
1909 int do_barriers, int wait, int max_mirrors)
1910 {
1911 struct buffer_head *bh;
1912 int i;
1913 int ret;
1914 int errors = 0;
1915 u32 crc;
1916 u64 bytenr;
1917 int last_barrier = 0;
1918
1919 if (max_mirrors == 0)
1920 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
1921
1922 /* make sure only the last submit_bh does a barrier */
1923 if (do_barriers) {
1924 for (i = 0; i < max_mirrors; i++) {
1925 bytenr = btrfs_sb_offset(i);
1926 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
1927 device->total_bytes)
1928 break;
1929 last_barrier = i;
1930 }
1931 }
1932
1933 for (i = 0; i < max_mirrors; i++) {
1934 bytenr = btrfs_sb_offset(i);
1935 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1936 break;
1937
1938 if (wait) {
1939 bh = __find_get_block(device->bdev, bytenr / 4096,
1940 BTRFS_SUPER_INFO_SIZE);
1941 BUG_ON(!bh);
1942 brelse(bh);
1943 wait_on_buffer(bh);
1944 if (buffer_uptodate(bh)) {
1945 brelse(bh);
1946 continue;
1947 }
1948 } else {
1949 btrfs_set_super_bytenr(sb, bytenr);
1950
1951 crc = ~(u32)0;
1952 crc = btrfs_csum_data(NULL, (char *)sb +
1953 BTRFS_CSUM_SIZE, crc,
1954 BTRFS_SUPER_INFO_SIZE -
1955 BTRFS_CSUM_SIZE);
1956 btrfs_csum_final(crc, sb->csum);
1957
1958 bh = __getblk(device->bdev, bytenr / 4096,
1959 BTRFS_SUPER_INFO_SIZE);
1960 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1961
1962 set_buffer_uptodate(bh);
1963 get_bh(bh);
1964 lock_buffer(bh);
1965 bh->b_end_io = btrfs_end_buffer_write_sync;
1966 }
1967
1968 if (i == last_barrier && do_barriers && device->barriers) {
1969 ret = submit_bh(WRITE_BARRIER, bh);
1970 if (ret == -EOPNOTSUPP) {
1971 printk("btrfs: disabling barriers on dev %s\n",
1972 device->name);
1973 set_buffer_uptodate(bh);
1974 device->barriers = 0;
1975 get_bh(bh);
1976 lock_buffer(bh);
1977 ret = submit_bh(WRITE, bh);
1978 }
1979 } else {
1980 ret = submit_bh(WRITE, bh);
1981 }
1982
1983 if (!ret && wait) {
1984 wait_on_buffer(bh);
1985 if (!buffer_uptodate(bh))
1986 errors++;
1987 } else if (ret) {
1988 errors++;
1989 }
1990 if (wait)
1991 brelse(bh);
1992 }
1993 return errors < i ? 0 : -1;
1994 }
1995
1996 int write_all_supers(struct btrfs_root *root, int max_mirrors)
1997 {
1998 struct list_head *cur;
1999 struct list_head *head = &root->fs_info->fs_devices->devices;
2000 struct btrfs_device *dev;
2001 struct btrfs_super_block *sb;
2002 struct btrfs_dev_item *dev_item;
2003 int ret;
2004 int do_barriers;
2005 int max_errors;
2006 int total_errors = 0;
2007 u64 flags;
2008
2009 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2010 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2011
2012 sb = &root->fs_info->super_for_commit;
2013 dev_item = &sb->dev_item;
2014 list_for_each(cur, head) {
2015 dev = list_entry(cur, struct btrfs_device, dev_list);
2016 if (!dev->bdev) {
2017 total_errors++;
2018 continue;
2019 }
2020 if (!dev->in_fs_metadata || !dev->writeable)
2021 continue;
2022
2023 btrfs_set_stack_device_generation(dev_item, 0);
2024 btrfs_set_stack_device_type(dev_item, dev->type);
2025 btrfs_set_stack_device_id(dev_item, dev->devid);
2026 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2027 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2028 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2029 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2030 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2031 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2032 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2033
2034 flags = btrfs_super_flags(sb);
2035 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2036
2037 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2038 if (ret)
2039 total_errors++;
2040 }
2041 if (total_errors > max_errors) {
2042 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2043 total_errors);
2044 BUG();
2045 }
2046
2047 total_errors = 0;
2048 list_for_each(cur, head) {
2049 dev = list_entry(cur, struct btrfs_device, dev_list);
2050 if (!dev->bdev)
2051 continue;
2052 if (!dev->in_fs_metadata || !dev->writeable)
2053 continue;
2054
2055 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2056 if (ret)
2057 total_errors++;
2058 }
2059 if (total_errors > max_errors) {
2060 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2061 total_errors);
2062 BUG();
2063 }
2064 return 0;
2065 }
2066
2067 int write_ctree_super(struct btrfs_trans_handle *trans,
2068 struct btrfs_root *root, int max_mirrors)
2069 {
2070 int ret;
2071
2072 ret = write_all_supers(root, max_mirrors);
2073 return ret;
2074 }
2075
2076 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2077 {
2078 radix_tree_delete(&fs_info->fs_roots_radix,
2079 (unsigned long)root->root_key.objectid);
2080 if (root->anon_super.s_dev) {
2081 down_write(&root->anon_super.s_umount);
2082 kill_anon_super(&root->anon_super);
2083 }
2084 if (root->node)
2085 free_extent_buffer(root->node);
2086 if (root->commit_root)
2087 free_extent_buffer(root->commit_root);
2088 kfree(root->name);
2089 kfree(root);
2090 return 0;
2091 }
2092
2093 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2094 {
2095 int ret;
2096 struct btrfs_root *gang[8];
2097 int i;
2098
2099 while (1) {
2100 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2101 (void **)gang, 0,
2102 ARRAY_SIZE(gang));
2103 if (!ret)
2104 break;
2105 for (i = 0; i < ret; i++)
2106 btrfs_free_fs_root(fs_info, gang[i]);
2107 }
2108 return 0;
2109 }
2110
2111 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2112 {
2113 u64 root_objectid = 0;
2114 struct btrfs_root *gang[8];
2115 int i;
2116 int ret;
2117
2118 while (1) {
2119 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2120 (void **)gang, root_objectid,
2121 ARRAY_SIZE(gang));
2122 if (!ret)
2123 break;
2124 for (i = 0; i < ret; i++) {
2125 root_objectid = gang[i]->root_key.objectid;
2126 ret = btrfs_find_dead_roots(fs_info->tree_root,
2127 root_objectid, gang[i]);
2128 BUG_ON(ret);
2129 btrfs_orphan_cleanup(gang[i]);
2130 }
2131 root_objectid++;
2132 }
2133 return 0;
2134 }
2135
2136 int btrfs_commit_super(struct btrfs_root *root)
2137 {
2138 struct btrfs_trans_handle *trans;
2139 int ret;
2140
2141 mutex_lock(&root->fs_info->cleaner_mutex);
2142 btrfs_clean_old_snapshots(root);
2143 mutex_unlock(&root->fs_info->cleaner_mutex);
2144 trans = btrfs_start_transaction(root, 1);
2145 ret = btrfs_commit_transaction(trans, root);
2146 BUG_ON(ret);
2147 /* run commit again to drop the original snapshot */
2148 trans = btrfs_start_transaction(root, 1);
2149 btrfs_commit_transaction(trans, root);
2150 ret = btrfs_write_and_wait_transaction(NULL, root);
2151 BUG_ON(ret);
2152
2153 ret = write_ctree_super(NULL, root, 0);
2154 return ret;
2155 }
2156
2157 int close_ctree(struct btrfs_root *root)
2158 {
2159 struct btrfs_fs_info *fs_info = root->fs_info;
2160 int ret;
2161
2162 fs_info->closing = 1;
2163 smp_mb();
2164
2165 kthread_stop(root->fs_info->transaction_kthread);
2166 kthread_stop(root->fs_info->cleaner_kthread);
2167
2168 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2169 ret = btrfs_commit_super(root);
2170 if (ret)
2171 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2172 }
2173
2174 if (fs_info->delalloc_bytes) {
2175 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2176 fs_info->delalloc_bytes);
2177 }
2178 if (fs_info->total_ref_cache_size) {
2179 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2180 (unsigned long long)fs_info->total_ref_cache_size);
2181 }
2182
2183 if (fs_info->extent_root->node)
2184 free_extent_buffer(fs_info->extent_root->node);
2185
2186 if (fs_info->tree_root->node)
2187 free_extent_buffer(fs_info->tree_root->node);
2188
2189 if (root->fs_info->chunk_root->node)
2190 free_extent_buffer(root->fs_info->chunk_root->node);
2191
2192 if (root->fs_info->dev_root->node)
2193 free_extent_buffer(root->fs_info->dev_root->node);
2194
2195 if (root->fs_info->csum_root->node)
2196 free_extent_buffer(root->fs_info->csum_root->node);
2197
2198 btrfs_free_block_groups(root->fs_info);
2199
2200 del_fs_roots(fs_info);
2201
2202 iput(fs_info->btree_inode);
2203
2204 btrfs_stop_workers(&fs_info->fixup_workers);
2205 btrfs_stop_workers(&fs_info->delalloc_workers);
2206 btrfs_stop_workers(&fs_info->workers);
2207 btrfs_stop_workers(&fs_info->endio_workers);
2208 btrfs_stop_workers(&fs_info->endio_meta_workers);
2209 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2210 btrfs_stop_workers(&fs_info->endio_write_workers);
2211 btrfs_stop_workers(&fs_info->submit_workers);
2212
2213 #if 0
2214 while (!list_empty(&fs_info->hashers)) {
2215 struct btrfs_hasher *hasher;
2216 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
2217 hashers);
2218 list_del(&hasher->hashers);
2219 crypto_free_hash(&fs_info->hash_tfm);
2220 kfree(hasher);
2221 }
2222 #endif
2223 btrfs_close_devices(fs_info->fs_devices);
2224 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2225
2226 bdi_destroy(&fs_info->bdi);
2227
2228 kfree(fs_info->extent_root);
2229 kfree(fs_info->tree_root);
2230 kfree(fs_info->chunk_root);
2231 kfree(fs_info->dev_root);
2232 kfree(fs_info->csum_root);
2233 return 0;
2234 }
2235
2236 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2237 {
2238 int ret;
2239 struct inode *btree_inode = buf->first_page->mapping->host;
2240
2241 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2242 if (!ret)
2243 return ret;
2244
2245 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2246 parent_transid);
2247 return !ret;
2248 }
2249
2250 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2251 {
2252 struct inode *btree_inode = buf->first_page->mapping->host;
2253 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2254 buf);
2255 }
2256
2257 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2258 {
2259 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2260 u64 transid = btrfs_header_generation(buf);
2261 struct inode *btree_inode = root->fs_info->btree_inode;
2262
2263 WARN_ON(!btrfs_tree_locked(buf));
2264 if (transid != root->fs_info->generation) {
2265 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2266 "found %llu running %llu\n",
2267 (unsigned long long)buf->start,
2268 (unsigned long long)transid,
2269 (unsigned long long)root->fs_info->generation);
2270 WARN_ON(1);
2271 }
2272 set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
2273 }
2274
2275 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2276 {
2277 /*
2278 * looks as though older kernels can get into trouble with
2279 * this code, they end up stuck in balance_dirty_pages forever
2280 */
2281 struct extent_io_tree *tree;
2282 u64 num_dirty;
2283 u64 start = 0;
2284 unsigned long thresh = 32 * 1024 * 1024;
2285 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2286
2287 if (current_is_pdflush() || current->flags & PF_MEMALLOC)
2288 return;
2289
2290 num_dirty = count_range_bits(tree, &start, (u64)-1,
2291 thresh, EXTENT_DIRTY);
2292 if (num_dirty > thresh) {
2293 balance_dirty_pages_ratelimited_nr(
2294 root->fs_info->btree_inode->i_mapping, 1);
2295 }
2296 return;
2297 }
2298
2299 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2300 {
2301 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2302 int ret;
2303 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2304 if (ret == 0)
2305 buf->flags |= EXTENT_UPTODATE;
2306 return ret;
2307 }
2308
2309 int btree_lock_page_hook(struct page *page)
2310 {
2311 struct inode *inode = page->mapping->host;
2312 struct btrfs_root *root = BTRFS_I(inode)->root;
2313 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2314 struct extent_buffer *eb;
2315 unsigned long len;
2316 u64 bytenr = page_offset(page);
2317
2318 if (page->private == EXTENT_PAGE_PRIVATE)
2319 goto out;
2320
2321 len = page->private >> 2;
2322 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2323 if (!eb)
2324 goto out;
2325
2326 btrfs_tree_lock(eb);
2327 spin_lock(&root->fs_info->hash_lock);
2328 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2329 spin_unlock(&root->fs_info->hash_lock);
2330 btrfs_tree_unlock(eb);
2331 free_extent_buffer(eb);
2332 out:
2333 lock_page(page);
2334 return 0;
2335 }
2336
2337 static struct extent_io_ops btree_extent_io_ops = {
2338 .write_cache_pages_lock_hook = btree_lock_page_hook,
2339 .readpage_end_io_hook = btree_readpage_end_io_hook,
2340 .submit_bio_hook = btree_submit_bio_hook,
2341 /* note we're sharing with inode.c for the merge bio hook */
2342 .merge_bio_hook = btrfs_merge_bio_hook,
2343 };
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