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MIPS: Fix sign-extension bug in 32-bit kernel on 32-bit hardware.
[linux-2.6/mini2440.git] / fs / btrfs / disk-io.c
blob0ff16d3331da4c12cf33afa41dbde1a735c6dce3
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include "compat.h"
30 #include "crc32c.h"
31 #include "ctree.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "volumes.h"
36 #include "print-tree.h"
37 #include "async-thread.h"
38 #include "locking.h"
39 #include "ref-cache.h"
40 #include "tree-log.h"
41 #include "free-space-cache.h"
42
43 static struct extent_io_ops btree_extent_io_ops;
44 static void end_workqueue_fn(struct btrfs_work *work);
45
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 /* These are used to set the lockdep class on the extent buffer locks.
80 * The class is set by the readpage_end_io_hook after the buffer has
81 * passed csum validation but before the pages are unlocked.
82 *
83 * The lockdep class is also set by btrfs_init_new_buffer on freshly
84 * allocated blocks.
85 *
86 * The class is based on the level in the tree block, which allows lockdep
87 * to know that lower nodes nest inside the locks of higher nodes.
88 *
89 * We also add a check to make sure the highest level of the tree is
90 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
91 * code needs update as well.
92 */
93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
94 # if BTRFS_MAX_LEVEL != 8
95 # error
96 # endif
97 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
98 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
99 /* leaf */
100 "btrfs-extent-00",
101 "btrfs-extent-01",
102 "btrfs-extent-02",
103 "btrfs-extent-03",
104 "btrfs-extent-04",
105 "btrfs-extent-05",
106 "btrfs-extent-06",
107 "btrfs-extent-07",
108 /* highest possible level */
109 "btrfs-extent-08",
110 };
111 #endif
112
113 /*
114 * extents on the btree inode are pretty simple, there's one extent
115 * that covers the entire device
116 */
117 static struct extent_map *btree_get_extent(struct inode *inode,
118 struct page *page, size_t page_offset, u64 start, u64 len,
119 int create)
120 {
121 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
122 struct extent_map *em;
123 int ret;
124
125 spin_lock(&em_tree->lock);
126 em = lookup_extent_mapping(em_tree, start, len);
127 if (em) {
128 em->bdev =
129 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
130 spin_unlock(&em_tree->lock);
131 goto out;
132 }
133 spin_unlock(&em_tree->lock);
134
135 em = alloc_extent_map(GFP_NOFS);
136 if (!em) {
137 em = ERR_PTR(-ENOMEM);
138 goto out;
139 }
140 em->start = 0;
141 em->len = (u64)-1;
142 em->block_len = (u64)-1;
143 em->block_start = 0;
144 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
145
146 spin_lock(&em_tree->lock);
147 ret = add_extent_mapping(em_tree, em);
148 if (ret == -EEXIST) {
149 u64 failed_start = em->start;
150 u64 failed_len = em->len;
151
152 free_extent_map(em);
153 em = lookup_extent_mapping(em_tree, start, len);
154 if (em) {
155 ret = 0;
156 } else {
157 em = lookup_extent_mapping(em_tree, failed_start,
158 failed_len);
159 ret = -EIO;
160 }
161 } else if (ret) {
162 free_extent_map(em);
163 em = NULL;
164 }
165 spin_unlock(&em_tree->lock);
166
167 if (ret)
168 em = ERR_PTR(ret);
169 out:
170 return em;
171 }
172
173 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
174 {
175 return btrfs_crc32c(seed, data, len);
176 }
177
178 void btrfs_csum_final(u32 crc, char *result)
179 {
180 *(__le32 *)result = ~cpu_to_le32(crc);
181 }
182
183 /*
184 * compute the csum for a btree block, and either verify it or write it
185 * into the csum field of the block.
186 */
187 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
188 int verify)
189 {
190 u16 csum_size =
191 btrfs_super_csum_size(&root->fs_info->super_copy);
192 char *result = NULL;
193 unsigned long len;
194 unsigned long cur_len;
195 unsigned long offset = BTRFS_CSUM_SIZE;
196 char *map_token = NULL;
197 char *kaddr;
198 unsigned long map_start;
199 unsigned long map_len;
200 int err;
201 u32 crc = ~(u32)0;
202 unsigned long inline_result;
203
204 len = buf->len - offset;
205 while (len > 0) {
206 err = map_private_extent_buffer(buf, offset, 32,
207 &map_token, &kaddr,
208 &map_start, &map_len, KM_USER0);
209 if (err)
210 return 1;
211 cur_len = min(len, map_len - (offset - map_start));
212 crc = btrfs_csum_data(root, kaddr + offset - map_start,
213 crc, cur_len);
214 len -= cur_len;
215 offset += cur_len;
216 unmap_extent_buffer(buf, map_token, KM_USER0);
217 }
218 if (csum_size > sizeof(inline_result)) {
219 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
220 if (!result)
221 return 1;
222 } else {
223 result = (char *)&inline_result;
224 }
225
226 btrfs_csum_final(crc, result);
227
228 if (verify) {
229 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
230 u32 val;
231 u32 found = 0;
232 memcpy(&found, result, csum_size);
233
234 read_extent_buffer(buf, &val, 0, csum_size);
235 if (printk_ratelimit()) {
236 printk(KERN_INFO "btrfs: %s checksum verify "
237 "failed on %llu wanted %X found %X "
238 "level %d\n",
239 root->fs_info->sb->s_id,
240 (unsigned long long)buf->start, val, found,
241 btrfs_header_level(buf));
242 }
243 if (result != (char *)&inline_result)
244 kfree(result);
245 return 1;
246 }
247 } else {
248 write_extent_buffer(buf, result, 0, csum_size);
249 }
250 if (result != (char *)&inline_result)
251 kfree(result);
252 return 0;
253 }
254
255 /*
256 * we can't consider a given block up to date unless the transid of the
257 * block matches the transid in the parent node's pointer. This is how we
258 * detect blocks that either didn't get written at all or got written
259 * in the wrong place.
260 */
261 static int verify_parent_transid(struct extent_io_tree *io_tree,
262 struct extent_buffer *eb, u64 parent_transid)
263 {
264 int ret;
265
266 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
267 return 0;
268
269 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
270 if (extent_buffer_uptodate(io_tree, eb) &&
271 btrfs_header_generation(eb) == parent_transid) {
272 ret = 0;
273 goto out;
274 }
275 if (printk_ratelimit()) {
276 printk("parent transid verify failed on %llu wanted %llu "
277 "found %llu\n",
278 (unsigned long long)eb->start,
279 (unsigned long long)parent_transid,
280 (unsigned long long)btrfs_header_generation(eb));
281 }
282 ret = 1;
283 clear_extent_buffer_uptodate(io_tree, eb);
284 out:
285 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
286 GFP_NOFS);
287 return ret;
288 }
289
290 /*
291 * helper to read a given tree block, doing retries as required when
292 * the checksums don't match and we have alternate mirrors to try.
293 */
294 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
295 struct extent_buffer *eb,
296 u64 start, u64 parent_transid)
297 {
298 struct extent_io_tree *io_tree;
299 int ret;
300 int num_copies = 0;
301 int mirror_num = 0;
302
303 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
304 while (1) {
305 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
306 btree_get_extent, mirror_num);
307 if (!ret &&
308 !verify_parent_transid(io_tree, eb, parent_transid))
309 return ret;
310
311 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
312 eb->start, eb->len);
313 if (num_copies == 1)
314 return ret;
315
316 mirror_num++;
317 if (mirror_num > num_copies)
318 return ret;
319 }
320 return -EIO;
321 }
322
323 /*
324 * checksum a dirty tree block before IO. This has extra checks to make sure
325 * we only fill in the checksum field in the first page of a multi-page block
326 */
327
328 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
329 {
330 struct extent_io_tree *tree;
331 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
332 u64 found_start;
333 int found_level;
334 unsigned long len;
335 struct extent_buffer *eb;
336 int ret;
337
338 tree = &BTRFS_I(page->mapping->host)->io_tree;
339
340 if (page->private == EXTENT_PAGE_PRIVATE)
341 goto out;
342 if (!page->private)
343 goto out;
344 len = page->private >> 2;
345 WARN_ON(len == 0);
346
347 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
348 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
349 btrfs_header_generation(eb));
350 BUG_ON(ret);
351 found_start = btrfs_header_bytenr(eb);
352 if (found_start != start) {
353 WARN_ON(1);
354 goto err;
355 }
356 if (eb->first_page != page) {
357 WARN_ON(1);
358 goto err;
359 }
360 if (!PageUptodate(page)) {
361 WARN_ON(1);
362 goto err;
363 }
364 found_level = btrfs_header_level(eb);
365
366 csum_tree_block(root, eb, 0);
367 err:
368 free_extent_buffer(eb);
369 out:
370 return 0;
371 }
372
373 static int check_tree_block_fsid(struct btrfs_root *root,
374 struct extent_buffer *eb)
375 {
376 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
377 u8 fsid[BTRFS_UUID_SIZE];
378 int ret = 1;
379
380 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
381 BTRFS_FSID_SIZE);
382 while (fs_devices) {
383 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
384 ret = 0;
385 break;
386 }
387 fs_devices = fs_devices->seed;
388 }
389 return ret;
390 }
391
392 #ifdef CONFIG_DEBUG_LOCK_ALLOC
393 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
394 {
395 lockdep_set_class_and_name(&eb->lock,
396 &btrfs_eb_class[level],
397 btrfs_eb_name[level]);
398 }
399 #endif
400
401 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
402 struct extent_state *state)
403 {
404 struct extent_io_tree *tree;
405 u64 found_start;
406 int found_level;
407 unsigned long len;
408 struct extent_buffer *eb;
409 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
410 int ret = 0;
411
412 tree = &BTRFS_I(page->mapping->host)->io_tree;
413 if (page->private == EXTENT_PAGE_PRIVATE)
414 goto out;
415 if (!page->private)
416 goto out;
417
418 len = page->private >> 2;
419 WARN_ON(len == 0);
420
421 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
422
423 found_start = btrfs_header_bytenr(eb);
424 if (found_start != start) {
425 if (printk_ratelimit()) {
426 printk(KERN_INFO "btrfs bad tree block start "
427 "%llu %llu\n",
428 (unsigned long long)found_start,
429 (unsigned long long)eb->start);
430 }
431 ret = -EIO;
432 goto err;
433 }
434 if (eb->first_page != page) {
435 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
436 eb->first_page->index, page->index);
437 WARN_ON(1);
438 ret = -EIO;
439 goto err;
440 }
441 if (check_tree_block_fsid(root, eb)) {
442 if (printk_ratelimit()) {
443 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
444 (unsigned long long)eb->start);
445 }
446 ret = -EIO;
447 goto err;
448 }
449 found_level = btrfs_header_level(eb);
450
451 btrfs_set_buffer_lockdep_class(eb, found_level);
452
453 ret = csum_tree_block(root, eb, 1);
454 if (ret)
455 ret = -EIO;
456
457 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
458 end = eb->start + end - 1;
459 err:
460 free_extent_buffer(eb);
461 out:
462 return ret;
463 }
464
465 static void end_workqueue_bio(struct bio *bio, int err)
466 {
467 struct end_io_wq *end_io_wq = bio->bi_private;
468 struct btrfs_fs_info *fs_info;
469
470 fs_info = end_io_wq->info;
471 end_io_wq->error = err;
472 end_io_wq->work.func = end_workqueue_fn;
473 end_io_wq->work.flags = 0;
474
475 if (bio->bi_rw & (1 << BIO_RW)) {
476 if (end_io_wq->metadata)
477 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
478 &end_io_wq->work);
479 else
480 btrfs_queue_worker(&fs_info->endio_write_workers,
481 &end_io_wq->work);
482 } else {
483 if (end_io_wq->metadata)
484 btrfs_queue_worker(&fs_info->endio_meta_workers,
485 &end_io_wq->work);
486 else
487 btrfs_queue_worker(&fs_info->endio_workers,
488 &end_io_wq->work);
489 }
490 }
491
492 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
493 int metadata)
494 {
495 struct end_io_wq *end_io_wq;
496 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
497 if (!end_io_wq)
498 return -ENOMEM;
499
500 end_io_wq->private = bio->bi_private;
501 end_io_wq->end_io = bio->bi_end_io;
502 end_io_wq->info = info;
503 end_io_wq->error = 0;
504 end_io_wq->bio = bio;
505 end_io_wq->metadata = metadata;
506
507 bio->bi_private = end_io_wq;
508 bio->bi_end_io = end_workqueue_bio;
509 return 0;
510 }
511
512 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
513 {
514 unsigned long limit = min_t(unsigned long,
515 info->workers.max_workers,
516 info->fs_devices->open_devices);
517 return 256 * limit;
518 }
519
520 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
521 {
522 return atomic_read(&info->nr_async_bios) >
523 btrfs_async_submit_limit(info);
524 }
525
526 static void run_one_async_start(struct btrfs_work *work)
527 {
528 struct btrfs_fs_info *fs_info;
529 struct async_submit_bio *async;
530
531 async = container_of(work, struct async_submit_bio, work);
532 fs_info = BTRFS_I(async->inode)->root->fs_info;
533 async->submit_bio_start(async->inode, async->rw, async->bio,
534 async->mirror_num, async->bio_flags);
535 }
536
537 static void run_one_async_done(struct btrfs_work *work)
538 {
539 struct btrfs_fs_info *fs_info;
540 struct async_submit_bio *async;
541 int limit;
542
543 async = container_of(work, struct async_submit_bio, work);
544 fs_info = BTRFS_I(async->inode)->root->fs_info;
545
546 limit = btrfs_async_submit_limit(fs_info);
547 limit = limit * 2 / 3;
548
549 atomic_dec(&fs_info->nr_async_submits);
550
551 if (atomic_read(&fs_info->nr_async_submits) < limit &&
552 waitqueue_active(&fs_info->async_submit_wait))
553 wake_up(&fs_info->async_submit_wait);
554
555 async->submit_bio_done(async->inode, async->rw, async->bio,
556 async->mirror_num, async->bio_flags);
557 }
558
559 static void run_one_async_free(struct btrfs_work *work)
560 {
561 struct async_submit_bio *async;
562
563 async = container_of(work, struct async_submit_bio, work);
564 kfree(async);
565 }
566
567 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
568 int rw, struct bio *bio, int mirror_num,
569 unsigned long bio_flags,
570 extent_submit_bio_hook_t *submit_bio_start,
571 extent_submit_bio_hook_t *submit_bio_done)
572 {
573 struct async_submit_bio *async;
574
575 async = kmalloc(sizeof(*async), GFP_NOFS);
576 if (!async)
577 return -ENOMEM;
578
579 async->inode = inode;
580 async->rw = rw;
581 async->bio = bio;
582 async->mirror_num = mirror_num;
583 async->submit_bio_start = submit_bio_start;
584 async->submit_bio_done = submit_bio_done;
585
586 async->work.func = run_one_async_start;
587 async->work.ordered_func = run_one_async_done;
588 async->work.ordered_free = run_one_async_free;
589
590 async->work.flags = 0;
591 async->bio_flags = bio_flags;
592
593 atomic_inc(&fs_info->nr_async_submits);
594
595 if (rw & (1 << BIO_RW_SYNCIO))
596 btrfs_set_work_high_prio(&async->work);
597
598 btrfs_queue_worker(&fs_info->workers, &async->work);
599
600 while (atomic_read(&fs_info->async_submit_draining) &&
601 atomic_read(&fs_info->nr_async_submits)) {
602 wait_event(fs_info->async_submit_wait,
603 (atomic_read(&fs_info->nr_async_submits) == 0));
604 }
605
606 return 0;
607 }
608
609 static int btree_csum_one_bio(struct bio *bio)
610 {
611 struct bio_vec *bvec = bio->bi_io_vec;
612 int bio_index = 0;
613 struct btrfs_root *root;
614
615 WARN_ON(bio->bi_vcnt <= 0);
616 while (bio_index < bio->bi_vcnt) {
617 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
618 csum_dirty_buffer(root, bvec->bv_page);
619 bio_index++;
620 bvec++;
621 }
622 return 0;
623 }
624
625 static int __btree_submit_bio_start(struct inode *inode, int rw,
626 struct bio *bio, int mirror_num,
627 unsigned long bio_flags)
628 {
629 /*
630 * when we're called for a write, we're already in the async
631 * submission context. Just jump into btrfs_map_bio
632 */
633 btree_csum_one_bio(bio);
634 return 0;
635 }
636
637 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
638 int mirror_num, unsigned long bio_flags)
639 {
640 /*
641 * when we're called for a write, we're already in the async
642 * submission context. Just jump into btrfs_map_bio
643 */
644 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
645 }
646
647 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
648 int mirror_num, unsigned long bio_flags)
649 {
650 int ret;
651
652 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
653 bio, 1);
654 BUG_ON(ret);
655
656 if (!(rw & (1 << BIO_RW))) {
657 /*
658 * called for a read, do the setup so that checksum validation
659 * can happen in the async kernel threads
660 */
661 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
662 mirror_num, 0);
663 }
664
665 /*
666 * kthread helpers are used to submit writes so that checksumming
667 * can happen in parallel across all CPUs
668 */
669 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
670 inode, rw, bio, mirror_num, 0,
671 __btree_submit_bio_start,
672 __btree_submit_bio_done);
673 }
674
675 static int btree_writepage(struct page *page, struct writeback_control *wbc)
676 {
677 struct extent_io_tree *tree;
678 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
679 struct extent_buffer *eb;
680 int was_dirty;
681
682 tree = &BTRFS_I(page->mapping->host)->io_tree;
683 if (!(current->flags & PF_MEMALLOC)) {
684 return extent_write_full_page(tree, page,
685 btree_get_extent, wbc);
686 }
687
688 redirty_page_for_writepage(wbc, page);
689 eb = btrfs_find_tree_block(root, page_offset(page),
690 PAGE_CACHE_SIZE);
691 WARN_ON(!eb);
692
693 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
694 if (!was_dirty) {
695 spin_lock(&root->fs_info->delalloc_lock);
696 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
697 spin_unlock(&root->fs_info->delalloc_lock);
698 }
699 free_extent_buffer(eb);
700
701 unlock_page(page);
702 return 0;
703 }
704
705 static int btree_writepages(struct address_space *mapping,
706 struct writeback_control *wbc)
707 {
708 struct extent_io_tree *tree;
709 tree = &BTRFS_I(mapping->host)->io_tree;
710 if (wbc->sync_mode == WB_SYNC_NONE) {
711 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
712 u64 num_dirty;
713 unsigned long thresh = 32 * 1024 * 1024;
714
715 if (wbc->for_kupdate)
716 return 0;
717
718 /* this is a bit racy, but that's ok */
719 num_dirty = root->fs_info->dirty_metadata_bytes;
720 if (num_dirty < thresh)
721 return 0;
722 }
723 return extent_writepages(tree, mapping, btree_get_extent, wbc);
724 }
725
726 static int btree_readpage(struct file *file, struct page *page)
727 {
728 struct extent_io_tree *tree;
729 tree = &BTRFS_I(page->mapping->host)->io_tree;
730 return extent_read_full_page(tree, page, btree_get_extent);
731 }
732
733 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
734 {
735 struct extent_io_tree *tree;
736 struct extent_map_tree *map;
737 int ret;
738
739 if (PageWriteback(page) || PageDirty(page))
740 return 0;
741
742 tree = &BTRFS_I(page->mapping->host)->io_tree;
743 map = &BTRFS_I(page->mapping->host)->extent_tree;
744
745 ret = try_release_extent_state(map, tree, page, gfp_flags);
746 if (!ret)
747 return 0;
748
749 ret = try_release_extent_buffer(tree, page);
750 if (ret == 1) {
751 ClearPagePrivate(page);
752 set_page_private(page, 0);
753 page_cache_release(page);
754 }
755
756 return ret;
757 }
758
759 static void btree_invalidatepage(struct page *page, unsigned long offset)
760 {
761 struct extent_io_tree *tree;
762 tree = &BTRFS_I(page->mapping->host)->io_tree;
763 extent_invalidatepage(tree, page, offset);
764 btree_releasepage(page, GFP_NOFS);
765 if (PagePrivate(page)) {
766 printk(KERN_WARNING "btrfs warning page private not zero "
767 "on page %llu\n", (unsigned long long)page_offset(page));
768 ClearPagePrivate(page);
769 set_page_private(page, 0);
770 page_cache_release(page);
771 }
772 }
773
774 static struct address_space_operations btree_aops = {
775 .readpage = btree_readpage,
776 .writepage = btree_writepage,
777 .writepages = btree_writepages,
778 .releasepage = btree_releasepage,
779 .invalidatepage = btree_invalidatepage,
780 .sync_page = block_sync_page,
781 };
782
783 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
784 u64 parent_transid)
785 {
786 struct extent_buffer *buf = NULL;
787 struct inode *btree_inode = root->fs_info->btree_inode;
788 int ret = 0;
789
790 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
791 if (!buf)
792 return 0;
793 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
794 buf, 0, 0, btree_get_extent, 0);
795 free_extent_buffer(buf);
796 return ret;
797 }
798
799 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
800 u64 bytenr, u32 blocksize)
801 {
802 struct inode *btree_inode = root->fs_info->btree_inode;
803 struct extent_buffer *eb;
804 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
805 bytenr, blocksize, GFP_NOFS);
806 return eb;
807 }
808
809 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
810 u64 bytenr, u32 blocksize)
811 {
812 struct inode *btree_inode = root->fs_info->btree_inode;
813 struct extent_buffer *eb;
814
815 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
816 bytenr, blocksize, NULL, GFP_NOFS);
817 return eb;
818 }
819
820
821 int btrfs_write_tree_block(struct extent_buffer *buf)
822 {
823 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
824 buf->start + buf->len - 1, WB_SYNC_ALL);
825 }
826
827 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
828 {
829 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
830 buf->start, buf->start + buf->len - 1);
831 }
832
833 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
834 u32 blocksize, u64 parent_transid)
835 {
836 struct extent_buffer *buf = NULL;
837 struct inode *btree_inode = root->fs_info->btree_inode;
838 struct extent_io_tree *io_tree;
839 int ret;
840
841 io_tree = &BTRFS_I(btree_inode)->io_tree;
842
843 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
844 if (!buf)
845 return NULL;
846
847 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
848
849 if (ret == 0)
850 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
851 else
852 WARN_ON(1);
853 return buf;
854
855 }
856
857 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
858 struct extent_buffer *buf)
859 {
860 struct inode *btree_inode = root->fs_info->btree_inode;
861 if (btrfs_header_generation(buf) ==
862 root->fs_info->running_transaction->transid) {
863 btrfs_assert_tree_locked(buf);
864
865 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
866 spin_lock(&root->fs_info->delalloc_lock);
867 if (root->fs_info->dirty_metadata_bytes >= buf->len)
868 root->fs_info->dirty_metadata_bytes -= buf->len;
869 else
870 WARN_ON(1);
871 spin_unlock(&root->fs_info->delalloc_lock);
872 }
873
874 /* ugh, clear_extent_buffer_dirty needs to lock the page */
875 btrfs_set_lock_blocking(buf);
876 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
877 buf);
878 }
879 return 0;
880 }
881
882 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
883 u32 stripesize, struct btrfs_root *root,
884 struct btrfs_fs_info *fs_info,
885 u64 objectid)
886 {
887 root->node = NULL;
888 root->commit_root = NULL;
889 root->ref_tree = NULL;
890 root->sectorsize = sectorsize;
891 root->nodesize = nodesize;
892 root->leafsize = leafsize;
893 root->stripesize = stripesize;
894 root->ref_cows = 0;
895 root->track_dirty = 0;
896
897 root->fs_info = fs_info;
898 root->objectid = objectid;
899 root->last_trans = 0;
900 root->highest_inode = 0;
901 root->last_inode_alloc = 0;
902 root->name = NULL;
903 root->in_sysfs = 0;
904
905 INIT_LIST_HEAD(&root->dirty_list);
906 INIT_LIST_HEAD(&root->orphan_list);
907 INIT_LIST_HEAD(&root->dead_list);
908 spin_lock_init(&root->node_lock);
909 spin_lock_init(&root->list_lock);
910 mutex_init(&root->objectid_mutex);
911 mutex_init(&root->log_mutex);
912 init_waitqueue_head(&root->log_writer_wait);
913 init_waitqueue_head(&root->log_commit_wait[0]);
914 init_waitqueue_head(&root->log_commit_wait[1]);
915 atomic_set(&root->log_commit[0], 0);
916 atomic_set(&root->log_commit[1], 0);
917 atomic_set(&root->log_writers, 0);
918 root->log_batch = 0;
919 root->log_transid = 0;
920 extent_io_tree_init(&root->dirty_log_pages,
921 fs_info->btree_inode->i_mapping, GFP_NOFS);
922
923 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
924 root->ref_tree = &root->ref_tree_struct;
925
926 memset(&root->root_key, 0, sizeof(root->root_key));
927 memset(&root->root_item, 0, sizeof(root->root_item));
928 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
929 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
930 root->defrag_trans_start = fs_info->generation;
931 init_completion(&root->kobj_unregister);
932 root->defrag_running = 0;
933 root->defrag_level = 0;
934 root->root_key.objectid = objectid;
935 root->anon_super.s_root = NULL;
936 root->anon_super.s_dev = 0;
937 INIT_LIST_HEAD(&root->anon_super.s_list);
938 INIT_LIST_HEAD(&root->anon_super.s_instances);
939 init_rwsem(&root->anon_super.s_umount);
940
941 return 0;
942 }
943
944 static int find_and_setup_root(struct btrfs_root *tree_root,
945 struct btrfs_fs_info *fs_info,
946 u64 objectid,
947 struct btrfs_root *root)
948 {
949 int ret;
950 u32 blocksize;
951 u64 generation;
952
953 __setup_root(tree_root->nodesize, tree_root->leafsize,
954 tree_root->sectorsize, tree_root->stripesize,
955 root, fs_info, objectid);
956 ret = btrfs_find_last_root(tree_root, objectid,
957 &root->root_item, &root->root_key);
958 BUG_ON(ret);
959
960 generation = btrfs_root_generation(&root->root_item);
961 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
962 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
963 blocksize, generation);
964 BUG_ON(!root->node);
965 return 0;
966 }
967
968 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
969 struct btrfs_fs_info *fs_info)
970 {
971 struct extent_buffer *eb;
972 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
973 u64 start = 0;
974 u64 end = 0;
975 int ret;
976
977 if (!log_root_tree)
978 return 0;
979
980 while (1) {
981 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
982 0, &start, &end, EXTENT_DIRTY);
983 if (ret)
984 break;
985
986 clear_extent_dirty(&log_root_tree->dirty_log_pages,
987 start, end, GFP_NOFS);
988 }
989 eb = fs_info->log_root_tree->node;
990
991 WARN_ON(btrfs_header_level(eb) != 0);
992 WARN_ON(btrfs_header_nritems(eb) != 0);
993
994 ret = btrfs_free_reserved_extent(fs_info->tree_root,
995 eb->start, eb->len);
996 BUG_ON(ret);
997
998 free_extent_buffer(eb);
999 kfree(fs_info->log_root_tree);
1000 fs_info->log_root_tree = NULL;
1001 return 0;
1002 }
1003
1004 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1005 struct btrfs_fs_info *fs_info)
1006 {
1007 struct btrfs_root *root;
1008 struct btrfs_root *tree_root = fs_info->tree_root;
1009 struct extent_buffer *leaf;
1010
1011 root = kzalloc(sizeof(*root), GFP_NOFS);
1012 if (!root)
1013 return ERR_PTR(-ENOMEM);
1014
1015 __setup_root(tree_root->nodesize, tree_root->leafsize,
1016 tree_root->sectorsize, tree_root->stripesize,
1017 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1018
1019 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1020 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1021 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1022 /*
1023 * log trees do not get reference counted because they go away
1024 * before a real commit is actually done. They do store pointers
1025 * to file data extents, and those reference counts still get
1026 * updated (along with back refs to the log tree).
1027 */
1028 root->ref_cows = 0;
1029
1030 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1031 0, BTRFS_TREE_LOG_OBJECTID,
1032 trans->transid, 0, 0, 0);
1033 if (IS_ERR(leaf)) {
1034 kfree(root);
1035 return ERR_CAST(leaf);
1036 }
1037
1038 root->node = leaf;
1039 btrfs_set_header_nritems(root->node, 0);
1040 btrfs_set_header_level(root->node, 0);
1041 btrfs_set_header_bytenr(root->node, root->node->start);
1042 btrfs_set_header_generation(root->node, trans->transid);
1043 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
1044
1045 write_extent_buffer(root->node, root->fs_info->fsid,
1046 (unsigned long)btrfs_header_fsid(root->node),
1047 BTRFS_FSID_SIZE);
1048 btrfs_mark_buffer_dirty(root->node);
1049 btrfs_tree_unlock(root->node);
1050 return root;
1051 }
1052
1053 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1054 struct btrfs_fs_info *fs_info)
1055 {
1056 struct btrfs_root *log_root;
1057
1058 log_root = alloc_log_tree(trans, fs_info);
1059 if (IS_ERR(log_root))
1060 return PTR_ERR(log_root);
1061 WARN_ON(fs_info->log_root_tree);
1062 fs_info->log_root_tree = log_root;
1063 return 0;
1064 }
1065
1066 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1067 struct btrfs_root *root)
1068 {
1069 struct btrfs_root *log_root;
1070 struct btrfs_inode_item *inode_item;
1071
1072 log_root = alloc_log_tree(trans, root->fs_info);
1073 if (IS_ERR(log_root))
1074 return PTR_ERR(log_root);
1075
1076 log_root->last_trans = trans->transid;
1077 log_root->root_key.offset = root->root_key.objectid;
1078
1079 inode_item = &log_root->root_item.inode;
1080 inode_item->generation = cpu_to_le64(1);
1081 inode_item->size = cpu_to_le64(3);
1082 inode_item->nlink = cpu_to_le32(1);
1083 inode_item->nbytes = cpu_to_le64(root->leafsize);
1084 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1085
1086 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1087 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1088
1089 WARN_ON(root->log_root);
1090 root->log_root = log_root;
1091 root->log_transid = 0;
1092 return 0;
1093 }
1094
1095 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1096 struct btrfs_key *location)
1097 {
1098 struct btrfs_root *root;
1099 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1100 struct btrfs_path *path;
1101 struct extent_buffer *l;
1102 u64 highest_inode;
1103 u64 generation;
1104 u32 blocksize;
1105 int ret = 0;
1106
1107 root = kzalloc(sizeof(*root), GFP_NOFS);
1108 if (!root)
1109 return ERR_PTR(-ENOMEM);
1110 if (location->offset == (u64)-1) {
1111 ret = find_and_setup_root(tree_root, fs_info,
1112 location->objectid, root);
1113 if (ret) {
1114 kfree(root);
1115 return ERR_PTR(ret);
1116 }
1117 goto insert;
1118 }
1119
1120 __setup_root(tree_root->nodesize, tree_root->leafsize,
1121 tree_root->sectorsize, tree_root->stripesize,
1122 root, fs_info, location->objectid);
1123
1124 path = btrfs_alloc_path();
1125 BUG_ON(!path);
1126 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1127 if (ret != 0) {
1128 if (ret > 0)
1129 ret = -ENOENT;
1130 goto out;
1131 }
1132 l = path->nodes[0];
1133 read_extent_buffer(l, &root->root_item,
1134 btrfs_item_ptr_offset(l, path->slots[0]),
1135 sizeof(root->root_item));
1136 memcpy(&root->root_key, location, sizeof(*location));
1137 ret = 0;
1138 out:
1139 btrfs_release_path(root, path);
1140 btrfs_free_path(path);
1141 if (ret) {
1142 kfree(root);
1143 return ERR_PTR(ret);
1144 }
1145 generation = btrfs_root_generation(&root->root_item);
1146 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1147 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1148 blocksize, generation);
1149 BUG_ON(!root->node);
1150 insert:
1151 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1152 root->ref_cows = 1;
1153 ret = btrfs_find_highest_inode(root, &highest_inode);
1154 if (ret == 0) {
1155 root->highest_inode = highest_inode;
1156 root->last_inode_alloc = highest_inode;
1157 }
1158 }
1159 return root;
1160 }
1161
1162 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1163 u64 root_objectid)
1164 {
1165 struct btrfs_root *root;
1166
1167 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1168 return fs_info->tree_root;
1169 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1170 return fs_info->extent_root;
1171
1172 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1173 (unsigned long)root_objectid);
1174 return root;
1175 }
1176
1177 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1178 struct btrfs_key *location)
1179 {
1180 struct btrfs_root *root;
1181 int ret;
1182
1183 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1184 return fs_info->tree_root;
1185 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1186 return fs_info->extent_root;
1187 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1188 return fs_info->chunk_root;
1189 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1190 return fs_info->dev_root;
1191 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1192 return fs_info->csum_root;
1193
1194 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1195 (unsigned long)location->objectid);
1196 if (root)
1197 return root;
1198
1199 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1200 if (IS_ERR(root))
1201 return root;
1202
1203 set_anon_super(&root->anon_super, NULL);
1204
1205 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1206 (unsigned long)root->root_key.objectid,
1207 root);
1208 if (ret) {
1209 free_extent_buffer(root->node);
1210 kfree(root);
1211 return ERR_PTR(ret);
1212 }
1213 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1214 ret = btrfs_find_dead_roots(fs_info->tree_root,
1215 root->root_key.objectid, root);
1216 BUG_ON(ret);
1217 btrfs_orphan_cleanup(root);
1218 }
1219 return root;
1220 }
1221
1222 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1223 struct btrfs_key *location,
1224 const char *name, int namelen)
1225 {
1226 struct btrfs_root *root;
1227 int ret;
1228
1229 root = btrfs_read_fs_root_no_name(fs_info, location);
1230 if (!root)
1231 return NULL;
1232
1233 if (root->in_sysfs)
1234 return root;
1235
1236 ret = btrfs_set_root_name(root, name, namelen);
1237 if (ret) {
1238 free_extent_buffer(root->node);
1239 kfree(root);
1240 return ERR_PTR(ret);
1241 }
1242 #if 0
1243 ret = btrfs_sysfs_add_root(root);
1244 if (ret) {
1245 free_extent_buffer(root->node);
1246 kfree(root->name);
1247 kfree(root);
1248 return ERR_PTR(ret);
1249 }
1250 #endif
1251 root->in_sysfs = 1;
1252 return root;
1253 }
1254
1255 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1256 {
1257 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1258 int ret = 0;
1259 struct btrfs_device *device;
1260 struct backing_dev_info *bdi;
1261
1262 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1263 if (!device->bdev)
1264 continue;
1265 bdi = blk_get_backing_dev_info(device->bdev);
1266 if (bdi && bdi_congested(bdi, bdi_bits)) {
1267 ret = 1;
1268 break;
1269 }
1270 }
1271 return ret;
1272 }
1273
1274 /*
1275 * this unplugs every device on the box, and it is only used when page
1276 * is null
1277 */
1278 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1279 {
1280 struct btrfs_device *device;
1281 struct btrfs_fs_info *info;
1282
1283 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1284 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1285 if (!device->bdev)
1286 continue;
1287
1288 bdi = blk_get_backing_dev_info(device->bdev);
1289 if (bdi->unplug_io_fn)
1290 bdi->unplug_io_fn(bdi, page);
1291 }
1292 }
1293
1294 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1295 {
1296 struct inode *inode;
1297 struct extent_map_tree *em_tree;
1298 struct extent_map *em;
1299 struct address_space *mapping;
1300 u64 offset;
1301
1302 /* the generic O_DIRECT read code does this */
1303 if (1 || !page) {
1304 __unplug_io_fn(bdi, page);
1305 return;
1306 }
1307
1308 /*
1309 * page->mapping may change at any time. Get a consistent copy
1310 * and use that for everything below
1311 */
1312 smp_mb();
1313 mapping = page->mapping;
1314 if (!mapping)
1315 return;
1316
1317 inode = mapping->host;
1318
1319 /*
1320 * don't do the expensive searching for a small number of
1321 * devices
1322 */
1323 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1324 __unplug_io_fn(bdi, page);
1325 return;
1326 }
1327
1328 offset = page_offset(page);
1329
1330 em_tree = &BTRFS_I(inode)->extent_tree;
1331 spin_lock(&em_tree->lock);
1332 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1333 spin_unlock(&em_tree->lock);
1334 if (!em) {
1335 __unplug_io_fn(bdi, page);
1336 return;
1337 }
1338
1339 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1340 free_extent_map(em);
1341 __unplug_io_fn(bdi, page);
1342 return;
1343 }
1344 offset = offset - em->start;
1345 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1346 em->block_start + offset, page);
1347 free_extent_map(em);
1348 }
1349
1350 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1351 {
1352 bdi_init(bdi);
1353 bdi->ra_pages = default_backing_dev_info.ra_pages;
1354 bdi->state = 0;
1355 bdi->capabilities = default_backing_dev_info.capabilities;
1356 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1357 bdi->unplug_io_data = info;
1358 bdi->congested_fn = btrfs_congested_fn;
1359 bdi->congested_data = info;
1360 return 0;
1361 }
1362
1363 static int bio_ready_for_csum(struct bio *bio)
1364 {
1365 u64 length = 0;
1366 u64 buf_len = 0;
1367 u64 start = 0;
1368 struct page *page;
1369 struct extent_io_tree *io_tree = NULL;
1370 struct btrfs_fs_info *info = NULL;
1371 struct bio_vec *bvec;
1372 int i;
1373 int ret;
1374
1375 bio_for_each_segment(bvec, bio, i) {
1376 page = bvec->bv_page;
1377 if (page->private == EXTENT_PAGE_PRIVATE) {
1378 length += bvec->bv_len;
1379 continue;
1380 }
1381 if (!page->private) {
1382 length += bvec->bv_len;
1383 continue;
1384 }
1385 length = bvec->bv_len;
1386 buf_len = page->private >> 2;
1387 start = page_offset(page) + bvec->bv_offset;
1388 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1389 info = BTRFS_I(page->mapping->host)->root->fs_info;
1390 }
1391 /* are we fully contained in this bio? */
1392 if (buf_len <= length)
1393 return 1;
1394
1395 ret = extent_range_uptodate(io_tree, start + length,
1396 start + buf_len - 1);
1397 return ret;
1398 }
1399
1400 /*
1401 * called by the kthread helper functions to finally call the bio end_io
1402 * functions. This is where read checksum verification actually happens
1403 */
1404 static void end_workqueue_fn(struct btrfs_work *work)
1405 {
1406 struct bio *bio;
1407 struct end_io_wq *end_io_wq;
1408 struct btrfs_fs_info *fs_info;
1409 int error;
1410
1411 end_io_wq = container_of(work, struct end_io_wq, work);
1412 bio = end_io_wq->bio;
1413 fs_info = end_io_wq->info;
1414
1415 /* metadata bio reads are special because the whole tree block must
1416 * be checksummed at once. This makes sure the entire block is in
1417 * ram and up to date before trying to verify things. For
1418 * blocksize <= pagesize, it is basically a noop
1419 */
1420 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1421 !bio_ready_for_csum(bio)) {
1422 btrfs_queue_worker(&fs_info->endio_meta_workers,
1423 &end_io_wq->work);
1424 return;
1425 }
1426 error = end_io_wq->error;
1427 bio->bi_private = end_io_wq->private;
1428 bio->bi_end_io = end_io_wq->end_io;
1429 kfree(end_io_wq);
1430 bio_endio(bio, error);
1431 }
1432
1433 static int cleaner_kthread(void *arg)
1434 {
1435 struct btrfs_root *root = arg;
1436
1437 do {
1438 smp_mb();
1439 if (root->fs_info->closing)
1440 break;
1441
1442 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1443 mutex_lock(&root->fs_info->cleaner_mutex);
1444 btrfs_clean_old_snapshots(root);
1445 mutex_unlock(&root->fs_info->cleaner_mutex);
1446
1447 if (freezing(current)) {
1448 refrigerator();
1449 } else {
1450 smp_mb();
1451 if (root->fs_info->closing)
1452 break;
1453 set_current_state(TASK_INTERRUPTIBLE);
1454 schedule();
1455 __set_current_state(TASK_RUNNING);
1456 }
1457 } while (!kthread_should_stop());
1458 return 0;
1459 }
1460
1461 static int transaction_kthread(void *arg)
1462 {
1463 struct btrfs_root *root = arg;
1464 struct btrfs_trans_handle *trans;
1465 struct btrfs_transaction *cur;
1466 unsigned long now;
1467 unsigned long delay;
1468 int ret;
1469
1470 do {
1471 smp_mb();
1472 if (root->fs_info->closing)
1473 break;
1474
1475 delay = HZ * 30;
1476 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1477 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1478
1479 mutex_lock(&root->fs_info->trans_mutex);
1480 cur = root->fs_info->running_transaction;
1481 if (!cur) {
1482 mutex_unlock(&root->fs_info->trans_mutex);
1483 goto sleep;
1484 }
1485
1486 now = get_seconds();
1487 if (now < cur->start_time || now - cur->start_time < 30) {
1488 mutex_unlock(&root->fs_info->trans_mutex);
1489 delay = HZ * 5;
1490 goto sleep;
1491 }
1492 mutex_unlock(&root->fs_info->trans_mutex);
1493 trans = btrfs_start_transaction(root, 1);
1494 ret = btrfs_commit_transaction(trans, root);
1495
1496 sleep:
1497 wake_up_process(root->fs_info->cleaner_kthread);
1498 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1499
1500 if (freezing(current)) {
1501 refrigerator();
1502 } else {
1503 if (root->fs_info->closing)
1504 break;
1505 set_current_state(TASK_INTERRUPTIBLE);
1506 schedule_timeout(delay);
1507 __set_current_state(TASK_RUNNING);
1508 }
1509 } while (!kthread_should_stop());
1510 return 0;
1511 }
1512
1513 struct btrfs_root *open_ctree(struct super_block *sb,
1514 struct btrfs_fs_devices *fs_devices,
1515 char *options)
1516 {
1517 u32 sectorsize;
1518 u32 nodesize;
1519 u32 leafsize;
1520 u32 blocksize;
1521 u32 stripesize;
1522 u64 generation;
1523 u64 features;
1524 struct btrfs_key location;
1525 struct buffer_head *bh;
1526 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1527 GFP_NOFS);
1528 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1529 GFP_NOFS);
1530 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1531 GFP_NOFS);
1532 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1533 GFP_NOFS);
1534 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1535 GFP_NOFS);
1536 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1537 GFP_NOFS);
1538 struct btrfs_root *log_tree_root;
1539
1540 int ret;
1541 int err = -EINVAL;
1542
1543 struct btrfs_super_block *disk_super;
1544
1545 if (!extent_root || !tree_root || !fs_info ||
1546 !chunk_root || !dev_root || !csum_root) {
1547 err = -ENOMEM;
1548 goto fail;
1549 }
1550 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1551 INIT_LIST_HEAD(&fs_info->trans_list);
1552 INIT_LIST_HEAD(&fs_info->dead_roots);
1553 INIT_LIST_HEAD(&fs_info->hashers);
1554 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1555 INIT_LIST_HEAD(&fs_info->ordered_operations);
1556 spin_lock_init(&fs_info->delalloc_lock);
1557 spin_lock_init(&fs_info->new_trans_lock);
1558 spin_lock_init(&fs_info->ref_cache_lock);
1559
1560 init_completion(&fs_info->kobj_unregister);
1561 fs_info->tree_root = tree_root;
1562 fs_info->extent_root = extent_root;
1563 fs_info->csum_root = csum_root;
1564 fs_info->chunk_root = chunk_root;
1565 fs_info->dev_root = dev_root;
1566 fs_info->fs_devices = fs_devices;
1567 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1568 INIT_LIST_HEAD(&fs_info->space_info);
1569 btrfs_mapping_init(&fs_info->mapping_tree);
1570 atomic_set(&fs_info->nr_async_submits, 0);
1571 atomic_set(&fs_info->async_delalloc_pages, 0);
1572 atomic_set(&fs_info->async_submit_draining, 0);
1573 atomic_set(&fs_info->nr_async_bios, 0);
1574 atomic_set(&fs_info->throttles, 0);
1575 atomic_set(&fs_info->throttle_gen, 0);
1576 fs_info->sb = sb;
1577 fs_info->max_extent = (u64)-1;
1578 fs_info->max_inline = 8192 * 1024;
1579 setup_bdi(fs_info, &fs_info->bdi);
1580 fs_info->btree_inode = new_inode(sb);
1581 fs_info->btree_inode->i_ino = 1;
1582 fs_info->btree_inode->i_nlink = 1;
1583 fs_info->metadata_ratio = 8;
1584
1585 fs_info->thread_pool_size = min_t(unsigned long,
1586 num_online_cpus() + 2, 8);
1587
1588 INIT_LIST_HEAD(&fs_info->ordered_extents);
1589 spin_lock_init(&fs_info->ordered_extent_lock);
1590
1591 sb->s_blocksize = 4096;
1592 sb->s_blocksize_bits = blksize_bits(4096);
1593
1594 /*
1595 * we set the i_size on the btree inode to the max possible int.
1596 * the real end of the address space is determined by all of
1597 * the devices in the system
1598 */
1599 fs_info->btree_inode->i_size = OFFSET_MAX;
1600 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1601 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1602
1603 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1604 fs_info->btree_inode->i_mapping,
1605 GFP_NOFS);
1606 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1607 GFP_NOFS);
1608
1609 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1610
1611 spin_lock_init(&fs_info->block_group_cache_lock);
1612 fs_info->block_group_cache_tree.rb_node = NULL;
1613
1614 extent_io_tree_init(&fs_info->pinned_extents,
1615 fs_info->btree_inode->i_mapping, GFP_NOFS);
1616 fs_info->do_barriers = 1;
1617
1618 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1619 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1620 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1621
1622 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1623 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1624 sizeof(struct btrfs_key));
1625 insert_inode_hash(fs_info->btree_inode);
1626
1627 mutex_init(&fs_info->trans_mutex);
1628 mutex_init(&fs_info->ordered_operations_mutex);
1629 mutex_init(&fs_info->tree_log_mutex);
1630 mutex_init(&fs_info->drop_mutex);
1631 mutex_init(&fs_info->chunk_mutex);
1632 mutex_init(&fs_info->transaction_kthread_mutex);
1633 mutex_init(&fs_info->cleaner_mutex);
1634 mutex_init(&fs_info->volume_mutex);
1635 mutex_init(&fs_info->tree_reloc_mutex);
1636
1637 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1638 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1639
1640 init_waitqueue_head(&fs_info->transaction_throttle);
1641 init_waitqueue_head(&fs_info->transaction_wait);
1642 init_waitqueue_head(&fs_info->async_submit_wait);
1643
1644 __setup_root(4096, 4096, 4096, 4096, tree_root,
1645 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1646
1647
1648 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1649 if (!bh)
1650 goto fail_iput;
1651
1652 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1653 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1654 sizeof(fs_info->super_for_commit));
1655 brelse(bh);
1656
1657 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1658
1659 disk_super = &fs_info->super_copy;
1660 if (!btrfs_super_root(disk_super))
1661 goto fail_iput;
1662
1663 ret = btrfs_parse_options(tree_root, options);
1664 if (ret) {
1665 err = ret;
1666 goto fail_iput;
1667 }
1668
1669 features = btrfs_super_incompat_flags(disk_super) &
1670 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1671 if (features) {
1672 printk(KERN_ERR "BTRFS: couldn't mount because of "
1673 "unsupported optional features (%Lx).\n",
1674 (unsigned long long)features);
1675 err = -EINVAL;
1676 goto fail_iput;
1677 }
1678
1679 features = btrfs_super_compat_ro_flags(disk_super) &
1680 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1681 if (!(sb->s_flags & MS_RDONLY) && features) {
1682 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1683 "unsupported option features (%Lx).\n",
1684 (unsigned long long)features);
1685 err = -EINVAL;
1686 goto fail_iput;
1687 }
1688
1689 /*
1690 * we need to start all the end_io workers up front because the
1691 * queue work function gets called at interrupt time, and so it
1692 * cannot dynamically grow.
1693 */
1694 btrfs_init_workers(&fs_info->workers, "worker",
1695 fs_info->thread_pool_size);
1696
1697 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1698 fs_info->thread_pool_size);
1699
1700 btrfs_init_workers(&fs_info->submit_workers, "submit",
1701 min_t(u64, fs_devices->num_devices,
1702 fs_info->thread_pool_size));
1703
1704 /* a higher idle thresh on the submit workers makes it much more
1705 * likely that bios will be send down in a sane order to the
1706 * devices
1707 */
1708 fs_info->submit_workers.idle_thresh = 64;
1709
1710 fs_info->workers.idle_thresh = 16;
1711 fs_info->workers.ordered = 1;
1712
1713 fs_info->delalloc_workers.idle_thresh = 2;
1714 fs_info->delalloc_workers.ordered = 1;
1715
1716 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1717 btrfs_init_workers(&fs_info->endio_workers, "endio",
1718 fs_info->thread_pool_size);
1719 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1720 fs_info->thread_pool_size);
1721 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1722 "endio-meta-write", fs_info->thread_pool_size);
1723 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1724 fs_info->thread_pool_size);
1725
1726 /*
1727 * endios are largely parallel and should have a very
1728 * low idle thresh
1729 */
1730 fs_info->endio_workers.idle_thresh = 4;
1731 fs_info->endio_meta_workers.idle_thresh = 4;
1732
1733 fs_info->endio_write_workers.idle_thresh = 64;
1734 fs_info->endio_meta_write_workers.idle_thresh = 64;
1735
1736 btrfs_start_workers(&fs_info->workers, 1);
1737 btrfs_start_workers(&fs_info->submit_workers, 1);
1738 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1739 btrfs_start_workers(&fs_info->fixup_workers, 1);
1740 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1741 btrfs_start_workers(&fs_info->endio_meta_workers,
1742 fs_info->thread_pool_size);
1743 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1744 fs_info->thread_pool_size);
1745 btrfs_start_workers(&fs_info->endio_write_workers,
1746 fs_info->thread_pool_size);
1747
1748 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1749 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1750 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1751
1752 nodesize = btrfs_super_nodesize(disk_super);
1753 leafsize = btrfs_super_leafsize(disk_super);
1754 sectorsize = btrfs_super_sectorsize(disk_super);
1755 stripesize = btrfs_super_stripesize(disk_super);
1756 tree_root->nodesize = nodesize;
1757 tree_root->leafsize = leafsize;
1758 tree_root->sectorsize = sectorsize;
1759 tree_root->stripesize = stripesize;
1760
1761 sb->s_blocksize = sectorsize;
1762 sb->s_blocksize_bits = blksize_bits(sectorsize);
1763
1764 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1765 sizeof(disk_super->magic))) {
1766 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1767 goto fail_sb_buffer;
1768 }
1769
1770 mutex_lock(&fs_info->chunk_mutex);
1771 ret = btrfs_read_sys_array(tree_root);
1772 mutex_unlock(&fs_info->chunk_mutex);
1773 if (ret) {
1774 printk(KERN_WARNING "btrfs: failed to read the system "
1775 "array on %s\n", sb->s_id);
1776 goto fail_sys_array;
1777 }
1778
1779 blocksize = btrfs_level_size(tree_root,
1780 btrfs_super_chunk_root_level(disk_super));
1781 generation = btrfs_super_chunk_root_generation(disk_super);
1782
1783 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1784 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1785
1786 chunk_root->node = read_tree_block(chunk_root,
1787 btrfs_super_chunk_root(disk_super),
1788 blocksize, generation);
1789 BUG_ON(!chunk_root->node);
1790
1791 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1792 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1793 BTRFS_UUID_SIZE);
1794
1795 mutex_lock(&fs_info->chunk_mutex);
1796 ret = btrfs_read_chunk_tree(chunk_root);
1797 mutex_unlock(&fs_info->chunk_mutex);
1798 if (ret) {
1799 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1800 sb->s_id);
1801 goto fail_chunk_root;
1802 }
1803
1804 btrfs_close_extra_devices(fs_devices);
1805
1806 blocksize = btrfs_level_size(tree_root,
1807 btrfs_super_root_level(disk_super));
1808 generation = btrfs_super_generation(disk_super);
1809
1810 tree_root->node = read_tree_block(tree_root,
1811 btrfs_super_root(disk_super),
1812 blocksize, generation);
1813 if (!tree_root->node)
1814 goto fail_chunk_root;
1815
1816
1817 ret = find_and_setup_root(tree_root, fs_info,
1818 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1819 if (ret)
1820 goto fail_tree_root;
1821 extent_root->track_dirty = 1;
1822
1823 ret = find_and_setup_root(tree_root, fs_info,
1824 BTRFS_DEV_TREE_OBJECTID, dev_root);
1825 dev_root->track_dirty = 1;
1826 if (ret)
1827 goto fail_extent_root;
1828
1829 ret = find_and_setup_root(tree_root, fs_info,
1830 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1831 if (ret)
1832 goto fail_extent_root;
1833
1834 csum_root->track_dirty = 1;
1835
1836 btrfs_read_block_groups(extent_root);
1837
1838 fs_info->generation = generation;
1839 fs_info->last_trans_committed = generation;
1840 fs_info->data_alloc_profile = (u64)-1;
1841 fs_info->metadata_alloc_profile = (u64)-1;
1842 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1843 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1844 "btrfs-cleaner");
1845 if (IS_ERR(fs_info->cleaner_kthread))
1846 goto fail_csum_root;
1847
1848 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1849 tree_root,
1850 "btrfs-transaction");
1851 if (IS_ERR(fs_info->transaction_kthread))
1852 goto fail_cleaner;
1853
1854 if (btrfs_super_log_root(disk_super) != 0) {
1855 u64 bytenr = btrfs_super_log_root(disk_super);
1856
1857 if (fs_devices->rw_devices == 0) {
1858 printk(KERN_WARNING "Btrfs log replay required "
1859 "on RO media\n");
1860 err = -EIO;
1861 goto fail_trans_kthread;
1862 }
1863 blocksize =
1864 btrfs_level_size(tree_root,
1865 btrfs_super_log_root_level(disk_super));
1866
1867 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1868 GFP_NOFS);
1869
1870 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1871 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1872
1873 log_tree_root->node = read_tree_block(tree_root, bytenr,
1874 blocksize,
1875 generation + 1);
1876 ret = btrfs_recover_log_trees(log_tree_root);
1877 BUG_ON(ret);
1878
1879 if (sb->s_flags & MS_RDONLY) {
1880 ret = btrfs_commit_super(tree_root);
1881 BUG_ON(ret);
1882 }
1883 }
1884
1885 if (!(sb->s_flags & MS_RDONLY)) {
1886 ret = btrfs_cleanup_reloc_trees(tree_root);
1887 BUG_ON(ret);
1888 }
1889
1890 location.objectid = BTRFS_FS_TREE_OBJECTID;
1891 location.type = BTRFS_ROOT_ITEM_KEY;
1892 location.offset = (u64)-1;
1893
1894 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1895 if (!fs_info->fs_root)
1896 goto fail_trans_kthread;
1897 return tree_root;
1898
1899 fail_trans_kthread:
1900 kthread_stop(fs_info->transaction_kthread);
1901 fail_cleaner:
1902 kthread_stop(fs_info->cleaner_kthread);
1903
1904 /*
1905 * make sure we're done with the btree inode before we stop our
1906 * kthreads
1907 */
1908 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1909 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1910
1911 fail_csum_root:
1912 free_extent_buffer(csum_root->node);
1913 fail_extent_root:
1914 free_extent_buffer(extent_root->node);
1915 fail_tree_root:
1916 free_extent_buffer(tree_root->node);
1917 fail_chunk_root:
1918 free_extent_buffer(chunk_root->node);
1919 fail_sys_array:
1920 free_extent_buffer(dev_root->node);
1921 fail_sb_buffer:
1922 btrfs_stop_workers(&fs_info->fixup_workers);
1923 btrfs_stop_workers(&fs_info->delalloc_workers);
1924 btrfs_stop_workers(&fs_info->workers);
1925 btrfs_stop_workers(&fs_info->endio_workers);
1926 btrfs_stop_workers(&fs_info->endio_meta_workers);
1927 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1928 btrfs_stop_workers(&fs_info->endio_write_workers);
1929 btrfs_stop_workers(&fs_info->submit_workers);
1930 fail_iput:
1931 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1932 iput(fs_info->btree_inode);
1933
1934 btrfs_close_devices(fs_info->fs_devices);
1935 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1936 bdi_destroy(&fs_info->bdi);
1937
1938 fail:
1939 kfree(extent_root);
1940 kfree(tree_root);
1941 kfree(fs_info);
1942 kfree(chunk_root);
1943 kfree(dev_root);
1944 kfree(csum_root);
1945 return ERR_PTR(err);
1946 }
1947
1948 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1949 {
1950 char b[BDEVNAME_SIZE];
1951
1952 if (uptodate) {
1953 set_buffer_uptodate(bh);
1954 } else {
1955 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1956 printk(KERN_WARNING "lost page write due to "
1957 "I/O error on %s\n",
1958 bdevname(bh->b_bdev, b));
1959 }
1960 /* note, we dont' set_buffer_write_io_error because we have
1961 * our own ways of dealing with the IO errors
1962 */
1963 clear_buffer_uptodate(bh);
1964 }
1965 unlock_buffer(bh);
1966 put_bh(bh);
1967 }
1968
1969 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1970 {
1971 struct buffer_head *bh;
1972 struct buffer_head *latest = NULL;
1973 struct btrfs_super_block *super;
1974 int i;
1975 u64 transid = 0;
1976 u64 bytenr;
1977
1978 /* we would like to check all the supers, but that would make
1979 * a btrfs mount succeed after a mkfs from a different FS.
1980 * So, we need to add a special mount option to scan for
1981 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1982 */
1983 for (i = 0; i < 1; i++) {
1984 bytenr = btrfs_sb_offset(i);
1985 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1986 break;
1987 bh = __bread(bdev, bytenr / 4096, 4096);
1988 if (!bh)
1989 continue;
1990
1991 super = (struct btrfs_super_block *)bh->b_data;
1992 if (btrfs_super_bytenr(super) != bytenr ||
1993 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1994 sizeof(super->magic))) {
1995 brelse(bh);
1996 continue;
1997 }
1998
1999 if (!latest || btrfs_super_generation(super) > transid) {
2000 brelse(latest);
2001 latest = bh;
2002 transid = btrfs_super_generation(super);
2003 } else {
2004 brelse(bh);
2005 }
2006 }
2007 return latest;
2008 }
2009
2010 static int write_dev_supers(struct btrfs_device *device,
2011 struct btrfs_super_block *sb,
2012 int do_barriers, int wait, int max_mirrors)
2013 {
2014 struct buffer_head *bh;
2015 int i;
2016 int ret;
2017 int errors = 0;
2018 u32 crc;
2019 u64 bytenr;
2020 int last_barrier = 0;
2021
2022 if (max_mirrors == 0)
2023 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2024
2025 /* make sure only the last submit_bh does a barrier */
2026 if (do_barriers) {
2027 for (i = 0; i < max_mirrors; i++) {
2028 bytenr = btrfs_sb_offset(i);
2029 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2030 device->total_bytes)
2031 break;
2032 last_barrier = i;
2033 }
2034 }
2035
2036 for (i = 0; i < max_mirrors; i++) {
2037 bytenr = btrfs_sb_offset(i);
2038 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2039 break;
2040
2041 if (wait) {
2042 bh = __find_get_block(device->bdev, bytenr / 4096,
2043 BTRFS_SUPER_INFO_SIZE);
2044 BUG_ON(!bh);
2045 brelse(bh);
2046 wait_on_buffer(bh);
2047 if (buffer_uptodate(bh)) {
2048 brelse(bh);
2049 continue;
2050 }
2051 } else {
2052 btrfs_set_super_bytenr(sb, bytenr);
2053
2054 crc = ~(u32)0;
2055 crc = btrfs_csum_data(NULL, (char *)sb +
2056 BTRFS_CSUM_SIZE, crc,
2057 BTRFS_SUPER_INFO_SIZE -
2058 BTRFS_CSUM_SIZE);
2059 btrfs_csum_final(crc, sb->csum);
2060
2061 bh = __getblk(device->bdev, bytenr / 4096,
2062 BTRFS_SUPER_INFO_SIZE);
2063 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2064
2065 set_buffer_uptodate(bh);
2066 get_bh(bh);
2067 lock_buffer(bh);
2068 bh->b_end_io = btrfs_end_buffer_write_sync;
2069 }
2070
2071 if (i == last_barrier && do_barriers && device->barriers) {
2072 ret = submit_bh(WRITE_BARRIER, bh);
2073 if (ret == -EOPNOTSUPP) {
2074 printk("btrfs: disabling barriers on dev %s\n",
2075 device->name);
2076 set_buffer_uptodate(bh);
2077 device->barriers = 0;
2078 get_bh(bh);
2079 lock_buffer(bh);
2080 ret = submit_bh(WRITE_SYNC, bh);
2081 }
2082 } else {
2083 ret = submit_bh(WRITE_SYNC, bh);
2084 }
2085
2086 if (!ret && wait) {
2087 wait_on_buffer(bh);
2088 if (!buffer_uptodate(bh))
2089 errors++;
2090 } else if (ret) {
2091 errors++;
2092 }
2093 if (wait)
2094 brelse(bh);
2095 }
2096 return errors < i ? 0 : -1;
2097 }
2098
2099 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2100 {
2101 struct list_head *head = &root->fs_info->fs_devices->devices;
2102 struct btrfs_device *dev;
2103 struct btrfs_super_block *sb;
2104 struct btrfs_dev_item *dev_item;
2105 int ret;
2106 int do_barriers;
2107 int max_errors;
2108 int total_errors = 0;
2109 u64 flags;
2110
2111 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2112 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2113
2114 sb = &root->fs_info->super_for_commit;
2115 dev_item = &sb->dev_item;
2116 list_for_each_entry(dev, head, dev_list) {
2117 if (!dev->bdev) {
2118 total_errors++;
2119 continue;
2120 }
2121 if (!dev->in_fs_metadata || !dev->writeable)
2122 continue;
2123
2124 btrfs_set_stack_device_generation(dev_item, 0);
2125 btrfs_set_stack_device_type(dev_item, dev->type);
2126 btrfs_set_stack_device_id(dev_item, dev->devid);
2127 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2128 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2129 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2130 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2131 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2132 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2133 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2134
2135 flags = btrfs_super_flags(sb);
2136 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2137
2138 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2139 if (ret)
2140 total_errors++;
2141 }
2142 if (total_errors > max_errors) {
2143 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2144 total_errors);
2145 BUG();
2146 }
2147
2148 total_errors = 0;
2149 list_for_each_entry(dev, head, dev_list) {
2150 if (!dev->bdev)
2151 continue;
2152 if (!dev->in_fs_metadata || !dev->writeable)
2153 continue;
2154
2155 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2156 if (ret)
2157 total_errors++;
2158 }
2159 if (total_errors > max_errors) {
2160 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2161 total_errors);
2162 BUG();
2163 }
2164 return 0;
2165 }
2166
2167 int write_ctree_super(struct btrfs_trans_handle *trans,
2168 struct btrfs_root *root, int max_mirrors)
2169 {
2170 int ret;
2171
2172 ret = write_all_supers(root, max_mirrors);
2173 return ret;
2174 }
2175
2176 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2177 {
2178 radix_tree_delete(&fs_info->fs_roots_radix,
2179 (unsigned long)root->root_key.objectid);
2180 if (root->anon_super.s_dev) {
2181 down_write(&root->anon_super.s_umount);
2182 kill_anon_super(&root->anon_super);
2183 }
2184 if (root->node)
2185 free_extent_buffer(root->node);
2186 if (root->commit_root)
2187 free_extent_buffer(root->commit_root);
2188 kfree(root->name);
2189 kfree(root);
2190 return 0;
2191 }
2192
2193 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2194 {
2195 int ret;
2196 struct btrfs_root *gang[8];
2197 int i;
2198
2199 while (1) {
2200 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2201 (void **)gang, 0,
2202 ARRAY_SIZE(gang));
2203 if (!ret)
2204 break;
2205 for (i = 0; i < ret; i++)
2206 btrfs_free_fs_root(fs_info, gang[i]);
2207 }
2208 return 0;
2209 }
2210
2211 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2212 {
2213 u64 root_objectid = 0;
2214 struct btrfs_root *gang[8];
2215 int i;
2216 int ret;
2217
2218 while (1) {
2219 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2220 (void **)gang, root_objectid,
2221 ARRAY_SIZE(gang));
2222 if (!ret)
2223 break;
2224 for (i = 0; i < ret; i++) {
2225 root_objectid = gang[i]->root_key.objectid;
2226 ret = btrfs_find_dead_roots(fs_info->tree_root,
2227 root_objectid, gang[i]);
2228 BUG_ON(ret);
2229 btrfs_orphan_cleanup(gang[i]);
2230 }
2231 root_objectid++;
2232 }
2233 return 0;
2234 }
2235
2236 int btrfs_commit_super(struct btrfs_root *root)
2237 {
2238 struct btrfs_trans_handle *trans;
2239 int ret;
2240
2241 mutex_lock(&root->fs_info->cleaner_mutex);
2242 btrfs_clean_old_snapshots(root);
2243 mutex_unlock(&root->fs_info->cleaner_mutex);
2244 trans = btrfs_start_transaction(root, 1);
2245 ret = btrfs_commit_transaction(trans, root);
2246 BUG_ON(ret);
2247 /* run commit again to drop the original snapshot */
2248 trans = btrfs_start_transaction(root, 1);
2249 btrfs_commit_transaction(trans, root);
2250 ret = btrfs_write_and_wait_transaction(NULL, root);
2251 BUG_ON(ret);
2252
2253 ret = write_ctree_super(NULL, root, 0);
2254 return ret;
2255 }
2256
2257 int close_ctree(struct btrfs_root *root)
2258 {
2259 struct btrfs_fs_info *fs_info = root->fs_info;
2260 int ret;
2261
2262 fs_info->closing = 1;
2263 smp_mb();
2264
2265 kthread_stop(root->fs_info->transaction_kthread);
2266 kthread_stop(root->fs_info->cleaner_kthread);
2267
2268 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2269 ret = btrfs_commit_super(root);
2270 if (ret)
2271 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2272 }
2273
2274 if (fs_info->delalloc_bytes) {
2275 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2276 (unsigned long long)fs_info->delalloc_bytes);
2277 }
2278 if (fs_info->total_ref_cache_size) {
2279 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2280 (unsigned long long)fs_info->total_ref_cache_size);
2281 }
2282
2283 if (fs_info->extent_root->node)
2284 free_extent_buffer(fs_info->extent_root->node);
2285
2286 if (fs_info->tree_root->node)
2287 free_extent_buffer(fs_info->tree_root->node);
2288
2289 if (root->fs_info->chunk_root->node)
2290 free_extent_buffer(root->fs_info->chunk_root->node);
2291
2292 if (root->fs_info->dev_root->node)
2293 free_extent_buffer(root->fs_info->dev_root->node);
2294
2295 if (root->fs_info->csum_root->node)
2296 free_extent_buffer(root->fs_info->csum_root->node);
2297
2298 btrfs_free_block_groups(root->fs_info);
2299
2300 del_fs_roots(fs_info);
2301
2302 iput(fs_info->btree_inode);
2303
2304 btrfs_stop_workers(&fs_info->fixup_workers);
2305 btrfs_stop_workers(&fs_info->delalloc_workers);
2306 btrfs_stop_workers(&fs_info->workers);
2307 btrfs_stop_workers(&fs_info->endio_workers);
2308 btrfs_stop_workers(&fs_info->endio_meta_workers);
2309 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2310 btrfs_stop_workers(&fs_info->endio_write_workers);
2311 btrfs_stop_workers(&fs_info->submit_workers);
2312
2313 btrfs_close_devices(fs_info->fs_devices);
2314 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2315
2316 bdi_destroy(&fs_info->bdi);
2317
2318 kfree(fs_info->extent_root);
2319 kfree(fs_info->tree_root);
2320 kfree(fs_info->chunk_root);
2321 kfree(fs_info->dev_root);
2322 kfree(fs_info->csum_root);
2323 return 0;
2324 }
2325
2326 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2327 {
2328 int ret;
2329 struct inode *btree_inode = buf->first_page->mapping->host;
2330
2331 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2332 if (!ret)
2333 return ret;
2334
2335 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2336 parent_transid);
2337 return !ret;
2338 }
2339
2340 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2341 {
2342 struct inode *btree_inode = buf->first_page->mapping->host;
2343 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2344 buf);
2345 }
2346
2347 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2348 {
2349 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2350 u64 transid = btrfs_header_generation(buf);
2351 struct inode *btree_inode = root->fs_info->btree_inode;
2352 int was_dirty;
2353
2354 btrfs_assert_tree_locked(buf);
2355 if (transid != root->fs_info->generation) {
2356 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2357 "found %llu running %llu\n",
2358 (unsigned long long)buf->start,
2359 (unsigned long long)transid,
2360 (unsigned long long)root->fs_info->generation);
2361 WARN_ON(1);
2362 }
2363 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2364 buf);
2365 if (!was_dirty) {
2366 spin_lock(&root->fs_info->delalloc_lock);
2367 root->fs_info->dirty_metadata_bytes += buf->len;
2368 spin_unlock(&root->fs_info->delalloc_lock);
2369 }
2370 }
2371
2372 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2373 {
2374 /*
2375 * looks as though older kernels can get into trouble with
2376 * this code, they end up stuck in balance_dirty_pages forever
2377 */
2378 struct extent_io_tree *tree;
2379 u64 num_dirty;
2380 u64 start = 0;
2381 unsigned long thresh = 32 * 1024 * 1024;
2382 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2383
2384 if (current->flags & PF_MEMALLOC)
2385 return;
2386
2387 num_dirty = count_range_bits(tree, &start, (u64)-1,
2388 thresh, EXTENT_DIRTY);
2389 if (num_dirty > thresh) {
2390 balance_dirty_pages_ratelimited_nr(
2391 root->fs_info->btree_inode->i_mapping, 1);
2392 }
2393 return;
2394 }
2395
2396 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2397 {
2398 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2399 int ret;
2400 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2401 if (ret == 0)
2402 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2403 return ret;
2404 }
2405
2406 int btree_lock_page_hook(struct page *page)
2407 {
2408 struct inode *inode = page->mapping->host;
2409 struct btrfs_root *root = BTRFS_I(inode)->root;
2410 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2411 struct extent_buffer *eb;
2412 unsigned long len;
2413 u64 bytenr = page_offset(page);
2414
2415 if (page->private == EXTENT_PAGE_PRIVATE)
2416 goto out;
2417
2418 len = page->private >> 2;
2419 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2420 if (!eb)
2421 goto out;
2422
2423 btrfs_tree_lock(eb);
2424 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2425
2426 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2427 spin_lock(&root->fs_info->delalloc_lock);
2428 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2429 root->fs_info->dirty_metadata_bytes -= eb->len;
2430 else
2431 WARN_ON(1);
2432 spin_unlock(&root->fs_info->delalloc_lock);
2433 }
2434
2435 btrfs_tree_unlock(eb);
2436 free_extent_buffer(eb);
2437 out:
2438 lock_page(page);
2439 return 0;
2440 }
2441
2442 static struct extent_io_ops btree_extent_io_ops = {
2443 .write_cache_pages_lock_hook = btree_lock_page_hook,
2444 .readpage_end_io_hook = btree_readpage_end_io_hook,
2445 .submit_bio_hook = btree_submit_bio_hook,
2446 /* note we're sharing with inode.c for the merge bio hook */
2447 .merge_bio_hook = btrfs_merge_bio_hook,
2448 };
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