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perf_counter tools: Fix top symbol table dump typo
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / disk-io.c
blob4b0ea0b80c234b11bc0861038749f83c58f38e70
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 return buf;
852
853 }
854
855 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
856 struct extent_buffer *buf)
857 {
858 struct inode *btree_inode = root->fs_info->btree_inode;
859 if (btrfs_header_generation(buf) ==
860 root->fs_info->running_transaction->transid) {
861 btrfs_assert_tree_locked(buf);
862
863 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
864 spin_lock(&root->fs_info->delalloc_lock);
865 if (root->fs_info->dirty_metadata_bytes >= buf->len)
866 root->fs_info->dirty_metadata_bytes -= buf->len;
867 else
868 WARN_ON(1);
869 spin_unlock(&root->fs_info->delalloc_lock);
870 }
871
872 /* ugh, clear_extent_buffer_dirty needs to lock the page */
873 btrfs_set_lock_blocking(buf);
874 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
875 buf);
876 }
877 return 0;
878 }
879
880 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
881 u32 stripesize, struct btrfs_root *root,
882 struct btrfs_fs_info *fs_info,
883 u64 objectid)
884 {
885 root->node = NULL;
886 root->commit_root = NULL;
887 root->ref_tree = NULL;
888 root->sectorsize = sectorsize;
889 root->nodesize = nodesize;
890 root->leafsize = leafsize;
891 root->stripesize = stripesize;
892 root->ref_cows = 0;
893 root->track_dirty = 0;
894
895 root->fs_info = fs_info;
896 root->objectid = objectid;
897 root->last_trans = 0;
898 root->highest_inode = 0;
899 root->last_inode_alloc = 0;
900 root->name = NULL;
901 root->in_sysfs = 0;
902
903 INIT_LIST_HEAD(&root->dirty_list);
904 INIT_LIST_HEAD(&root->orphan_list);
905 INIT_LIST_HEAD(&root->dead_list);
906 spin_lock_init(&root->node_lock);
907 spin_lock_init(&root->list_lock);
908 mutex_init(&root->objectid_mutex);
909 mutex_init(&root->log_mutex);
910 init_waitqueue_head(&root->log_writer_wait);
911 init_waitqueue_head(&root->log_commit_wait[0]);
912 init_waitqueue_head(&root->log_commit_wait[1]);
913 atomic_set(&root->log_commit[0], 0);
914 atomic_set(&root->log_commit[1], 0);
915 atomic_set(&root->log_writers, 0);
916 root->log_batch = 0;
917 root->log_transid = 0;
918 extent_io_tree_init(&root->dirty_log_pages,
919 fs_info->btree_inode->i_mapping, GFP_NOFS);
920
921 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
922 root->ref_tree = &root->ref_tree_struct;
923
924 memset(&root->root_key, 0, sizeof(root->root_key));
925 memset(&root->root_item, 0, sizeof(root->root_item));
926 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
927 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
928 root->defrag_trans_start = fs_info->generation;
929 init_completion(&root->kobj_unregister);
930 root->defrag_running = 0;
931 root->defrag_level = 0;
932 root->root_key.objectid = objectid;
933 root->anon_super.s_root = NULL;
934 root->anon_super.s_dev = 0;
935 INIT_LIST_HEAD(&root->anon_super.s_list);
936 INIT_LIST_HEAD(&root->anon_super.s_instances);
937 init_rwsem(&root->anon_super.s_umount);
938
939 return 0;
940 }
941
942 static int find_and_setup_root(struct btrfs_root *tree_root,
943 struct btrfs_fs_info *fs_info,
944 u64 objectid,
945 struct btrfs_root *root)
946 {
947 int ret;
948 u32 blocksize;
949 u64 generation;
950
951 __setup_root(tree_root->nodesize, tree_root->leafsize,
952 tree_root->sectorsize, tree_root->stripesize,
953 root, fs_info, objectid);
954 ret = btrfs_find_last_root(tree_root, objectid,
955 &root->root_item, &root->root_key);
956 BUG_ON(ret);
957
958 generation = btrfs_root_generation(&root->root_item);
959 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
960 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
961 blocksize, generation);
962 BUG_ON(!root->node);
963 return 0;
964 }
965
966 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
967 struct btrfs_fs_info *fs_info)
968 {
969 struct extent_buffer *eb;
970 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
971 u64 start = 0;
972 u64 end = 0;
973 int ret;
974
975 if (!log_root_tree)
976 return 0;
977
978 while (1) {
979 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
980 0, &start, &end, EXTENT_DIRTY);
981 if (ret)
982 break;
983
984 clear_extent_dirty(&log_root_tree->dirty_log_pages,
985 start, end, GFP_NOFS);
986 }
987 eb = fs_info->log_root_tree->node;
988
989 WARN_ON(btrfs_header_level(eb) != 0);
990 WARN_ON(btrfs_header_nritems(eb) != 0);
991
992 ret = btrfs_free_reserved_extent(fs_info->tree_root,
993 eb->start, eb->len);
994 BUG_ON(ret);
995
996 free_extent_buffer(eb);
997 kfree(fs_info->log_root_tree);
998 fs_info->log_root_tree = NULL;
999 return 0;
1000 }
1001
1002 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1003 struct btrfs_fs_info *fs_info)
1004 {
1005 struct btrfs_root *root;
1006 struct btrfs_root *tree_root = fs_info->tree_root;
1007 struct extent_buffer *leaf;
1008
1009 root = kzalloc(sizeof(*root), GFP_NOFS);
1010 if (!root)
1011 return ERR_PTR(-ENOMEM);
1012
1013 __setup_root(tree_root->nodesize, tree_root->leafsize,
1014 tree_root->sectorsize, tree_root->stripesize,
1015 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1016
1017 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1018 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1019 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1020 /*
1021 * log trees do not get reference counted because they go away
1022 * before a real commit is actually done. They do store pointers
1023 * to file data extents, and those reference counts still get
1024 * updated (along with back refs to the log tree).
1025 */
1026 root->ref_cows = 0;
1027
1028 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1029 0, BTRFS_TREE_LOG_OBJECTID,
1030 trans->transid, 0, 0, 0);
1031 if (IS_ERR(leaf)) {
1032 kfree(root);
1033 return ERR_CAST(leaf);
1034 }
1035
1036 root->node = leaf;
1037 btrfs_set_header_nritems(root->node, 0);
1038 btrfs_set_header_level(root->node, 0);
1039 btrfs_set_header_bytenr(root->node, root->node->start);
1040 btrfs_set_header_generation(root->node, trans->transid);
1041 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
1042
1043 write_extent_buffer(root->node, root->fs_info->fsid,
1044 (unsigned long)btrfs_header_fsid(root->node),
1045 BTRFS_FSID_SIZE);
1046 btrfs_mark_buffer_dirty(root->node);
1047 btrfs_tree_unlock(root->node);
1048 return root;
1049 }
1050
1051 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1052 struct btrfs_fs_info *fs_info)
1053 {
1054 struct btrfs_root *log_root;
1055
1056 log_root = alloc_log_tree(trans, fs_info);
1057 if (IS_ERR(log_root))
1058 return PTR_ERR(log_root);
1059 WARN_ON(fs_info->log_root_tree);
1060 fs_info->log_root_tree = log_root;
1061 return 0;
1062 }
1063
1064 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1065 struct btrfs_root *root)
1066 {
1067 struct btrfs_root *log_root;
1068 struct btrfs_inode_item *inode_item;
1069
1070 log_root = alloc_log_tree(trans, root->fs_info);
1071 if (IS_ERR(log_root))
1072 return PTR_ERR(log_root);
1073
1074 log_root->last_trans = trans->transid;
1075 log_root->root_key.offset = root->root_key.objectid;
1076
1077 inode_item = &log_root->root_item.inode;
1078 inode_item->generation = cpu_to_le64(1);
1079 inode_item->size = cpu_to_le64(3);
1080 inode_item->nlink = cpu_to_le32(1);
1081 inode_item->nbytes = cpu_to_le64(root->leafsize);
1082 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1083
1084 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1085 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1086
1087 WARN_ON(root->log_root);
1088 root->log_root = log_root;
1089 root->log_transid = 0;
1090 return 0;
1091 }
1092
1093 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1094 struct btrfs_key *location)
1095 {
1096 struct btrfs_root *root;
1097 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1098 struct btrfs_path *path;
1099 struct extent_buffer *l;
1100 u64 highest_inode;
1101 u64 generation;
1102 u32 blocksize;
1103 int ret = 0;
1104
1105 root = kzalloc(sizeof(*root), GFP_NOFS);
1106 if (!root)
1107 return ERR_PTR(-ENOMEM);
1108 if (location->offset == (u64)-1) {
1109 ret = find_and_setup_root(tree_root, fs_info,
1110 location->objectid, root);
1111 if (ret) {
1112 kfree(root);
1113 return ERR_PTR(ret);
1114 }
1115 goto insert;
1116 }
1117
1118 __setup_root(tree_root->nodesize, tree_root->leafsize,
1119 tree_root->sectorsize, tree_root->stripesize,
1120 root, fs_info, location->objectid);
1121
1122 path = btrfs_alloc_path();
1123 BUG_ON(!path);
1124 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1125 if (ret != 0) {
1126 if (ret > 0)
1127 ret = -ENOENT;
1128 goto out;
1129 }
1130 l = path->nodes[0];
1131 read_extent_buffer(l, &root->root_item,
1132 btrfs_item_ptr_offset(l, path->slots[0]),
1133 sizeof(root->root_item));
1134 memcpy(&root->root_key, location, sizeof(*location));
1135 ret = 0;
1136 out:
1137 btrfs_release_path(root, path);
1138 btrfs_free_path(path);
1139 if (ret) {
1140 kfree(root);
1141 return ERR_PTR(ret);
1142 }
1143 generation = btrfs_root_generation(&root->root_item);
1144 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1145 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1146 blocksize, generation);
1147 BUG_ON(!root->node);
1148 insert:
1149 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1150 root->ref_cows = 1;
1151 ret = btrfs_find_highest_inode(root, &highest_inode);
1152 if (ret == 0) {
1153 root->highest_inode = highest_inode;
1154 root->last_inode_alloc = highest_inode;
1155 }
1156 }
1157 return root;
1158 }
1159
1160 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1161 u64 root_objectid)
1162 {
1163 struct btrfs_root *root;
1164
1165 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1166 return fs_info->tree_root;
1167 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1168 return fs_info->extent_root;
1169
1170 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1171 (unsigned long)root_objectid);
1172 return root;
1173 }
1174
1175 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1176 struct btrfs_key *location)
1177 {
1178 struct btrfs_root *root;
1179 int ret;
1180
1181 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1182 return fs_info->tree_root;
1183 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1184 return fs_info->extent_root;
1185 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1186 return fs_info->chunk_root;
1187 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1188 return fs_info->dev_root;
1189 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1190 return fs_info->csum_root;
1191
1192 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1193 (unsigned long)location->objectid);
1194 if (root)
1195 return root;
1196
1197 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1198 if (IS_ERR(root))
1199 return root;
1200
1201 set_anon_super(&root->anon_super, NULL);
1202
1203 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1204 (unsigned long)root->root_key.objectid,
1205 root);
1206 if (ret) {
1207 free_extent_buffer(root->node);
1208 kfree(root);
1209 return ERR_PTR(ret);
1210 }
1211 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1212 ret = btrfs_find_dead_roots(fs_info->tree_root,
1213 root->root_key.objectid, root);
1214 BUG_ON(ret);
1215 btrfs_orphan_cleanup(root);
1216 }
1217 return root;
1218 }
1219
1220 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1221 struct btrfs_key *location,
1222 const char *name, int namelen)
1223 {
1224 struct btrfs_root *root;
1225 int ret;
1226
1227 root = btrfs_read_fs_root_no_name(fs_info, location);
1228 if (!root)
1229 return NULL;
1230
1231 if (root->in_sysfs)
1232 return root;
1233
1234 ret = btrfs_set_root_name(root, name, namelen);
1235 if (ret) {
1236 free_extent_buffer(root->node);
1237 kfree(root);
1238 return ERR_PTR(ret);
1239 }
1240 #if 0
1241 ret = btrfs_sysfs_add_root(root);
1242 if (ret) {
1243 free_extent_buffer(root->node);
1244 kfree(root->name);
1245 kfree(root);
1246 return ERR_PTR(ret);
1247 }
1248 #endif
1249 root->in_sysfs = 1;
1250 return root;
1251 }
1252
1253 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1254 {
1255 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1256 int ret = 0;
1257 struct btrfs_device *device;
1258 struct backing_dev_info *bdi;
1259
1260 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1261 if (!device->bdev)
1262 continue;
1263 bdi = blk_get_backing_dev_info(device->bdev);
1264 if (bdi && bdi_congested(bdi, bdi_bits)) {
1265 ret = 1;
1266 break;
1267 }
1268 }
1269 return ret;
1270 }
1271
1272 /*
1273 * this unplugs every device on the box, and it is only used when page
1274 * is null
1275 */
1276 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1277 {
1278 struct btrfs_device *device;
1279 struct btrfs_fs_info *info;
1280
1281 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1282 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1283 if (!device->bdev)
1284 continue;
1285
1286 bdi = blk_get_backing_dev_info(device->bdev);
1287 if (bdi->unplug_io_fn)
1288 bdi->unplug_io_fn(bdi, page);
1289 }
1290 }
1291
1292 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1293 {
1294 struct inode *inode;
1295 struct extent_map_tree *em_tree;
1296 struct extent_map *em;
1297 struct address_space *mapping;
1298 u64 offset;
1299
1300 /* the generic O_DIRECT read code does this */
1301 if (1 || !page) {
1302 __unplug_io_fn(bdi, page);
1303 return;
1304 }
1305
1306 /*
1307 * page->mapping may change at any time. Get a consistent copy
1308 * and use that for everything below
1309 */
1310 smp_mb();
1311 mapping = page->mapping;
1312 if (!mapping)
1313 return;
1314
1315 inode = mapping->host;
1316
1317 /*
1318 * don't do the expensive searching for a small number of
1319 * devices
1320 */
1321 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1322 __unplug_io_fn(bdi, page);
1323 return;
1324 }
1325
1326 offset = page_offset(page);
1327
1328 em_tree = &BTRFS_I(inode)->extent_tree;
1329 spin_lock(&em_tree->lock);
1330 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1331 spin_unlock(&em_tree->lock);
1332 if (!em) {
1333 __unplug_io_fn(bdi, page);
1334 return;
1335 }
1336
1337 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1338 free_extent_map(em);
1339 __unplug_io_fn(bdi, page);
1340 return;
1341 }
1342 offset = offset - em->start;
1343 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1344 em->block_start + offset, page);
1345 free_extent_map(em);
1346 }
1347
1348 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1349 {
1350 bdi_init(bdi);
1351 bdi->ra_pages = default_backing_dev_info.ra_pages;
1352 bdi->state = 0;
1353 bdi->capabilities = default_backing_dev_info.capabilities;
1354 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1355 bdi->unplug_io_data = info;
1356 bdi->congested_fn = btrfs_congested_fn;
1357 bdi->congested_data = info;
1358 return 0;
1359 }
1360
1361 static int bio_ready_for_csum(struct bio *bio)
1362 {
1363 u64 length = 0;
1364 u64 buf_len = 0;
1365 u64 start = 0;
1366 struct page *page;
1367 struct extent_io_tree *io_tree = NULL;
1368 struct btrfs_fs_info *info = NULL;
1369 struct bio_vec *bvec;
1370 int i;
1371 int ret;
1372
1373 bio_for_each_segment(bvec, bio, i) {
1374 page = bvec->bv_page;
1375 if (page->private == EXTENT_PAGE_PRIVATE) {
1376 length += bvec->bv_len;
1377 continue;
1378 }
1379 if (!page->private) {
1380 length += bvec->bv_len;
1381 continue;
1382 }
1383 length = bvec->bv_len;
1384 buf_len = page->private >> 2;
1385 start = page_offset(page) + bvec->bv_offset;
1386 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1387 info = BTRFS_I(page->mapping->host)->root->fs_info;
1388 }
1389 /* are we fully contained in this bio? */
1390 if (buf_len <= length)
1391 return 1;
1392
1393 ret = extent_range_uptodate(io_tree, start + length,
1394 start + buf_len - 1);
1395 return ret;
1396 }
1397
1398 /*
1399 * called by the kthread helper functions to finally call the bio end_io
1400 * functions. This is where read checksum verification actually happens
1401 */
1402 static void end_workqueue_fn(struct btrfs_work *work)
1403 {
1404 struct bio *bio;
1405 struct end_io_wq *end_io_wq;
1406 struct btrfs_fs_info *fs_info;
1407 int error;
1408
1409 end_io_wq = container_of(work, struct end_io_wq, work);
1410 bio = end_io_wq->bio;
1411 fs_info = end_io_wq->info;
1412
1413 /* metadata bio reads are special because the whole tree block must
1414 * be checksummed at once. This makes sure the entire block is in
1415 * ram and up to date before trying to verify things. For
1416 * blocksize <= pagesize, it is basically a noop
1417 */
1418 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1419 !bio_ready_for_csum(bio)) {
1420 btrfs_queue_worker(&fs_info->endio_meta_workers,
1421 &end_io_wq->work);
1422 return;
1423 }
1424 error = end_io_wq->error;
1425 bio->bi_private = end_io_wq->private;
1426 bio->bi_end_io = end_io_wq->end_io;
1427 kfree(end_io_wq);
1428 bio_endio(bio, error);
1429 }
1430
1431 static int cleaner_kthread(void *arg)
1432 {
1433 struct btrfs_root *root = arg;
1434
1435 do {
1436 smp_mb();
1437 if (root->fs_info->closing)
1438 break;
1439
1440 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1441 mutex_lock(&root->fs_info->cleaner_mutex);
1442 btrfs_clean_old_snapshots(root);
1443 mutex_unlock(&root->fs_info->cleaner_mutex);
1444
1445 if (freezing(current)) {
1446 refrigerator();
1447 } else {
1448 smp_mb();
1449 if (root->fs_info->closing)
1450 break;
1451 set_current_state(TASK_INTERRUPTIBLE);
1452 schedule();
1453 __set_current_state(TASK_RUNNING);
1454 }
1455 } while (!kthread_should_stop());
1456 return 0;
1457 }
1458
1459 static int transaction_kthread(void *arg)
1460 {
1461 struct btrfs_root *root = arg;
1462 struct btrfs_trans_handle *trans;
1463 struct btrfs_transaction *cur;
1464 unsigned long now;
1465 unsigned long delay;
1466 int ret;
1467
1468 do {
1469 smp_mb();
1470 if (root->fs_info->closing)
1471 break;
1472
1473 delay = HZ * 30;
1474 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1475 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1476
1477 mutex_lock(&root->fs_info->trans_mutex);
1478 cur = root->fs_info->running_transaction;
1479 if (!cur) {
1480 mutex_unlock(&root->fs_info->trans_mutex);
1481 goto sleep;
1482 }
1483
1484 now = get_seconds();
1485 if (now < cur->start_time || now - cur->start_time < 30) {
1486 mutex_unlock(&root->fs_info->trans_mutex);
1487 delay = HZ * 5;
1488 goto sleep;
1489 }
1490 mutex_unlock(&root->fs_info->trans_mutex);
1491 trans = btrfs_start_transaction(root, 1);
1492 ret = btrfs_commit_transaction(trans, root);
1493
1494 sleep:
1495 wake_up_process(root->fs_info->cleaner_kthread);
1496 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1497
1498 if (freezing(current)) {
1499 refrigerator();
1500 } else {
1501 if (root->fs_info->closing)
1502 break;
1503 set_current_state(TASK_INTERRUPTIBLE);
1504 schedule_timeout(delay);
1505 __set_current_state(TASK_RUNNING);
1506 }
1507 } while (!kthread_should_stop());
1508 return 0;
1509 }
1510
1511 struct btrfs_root *open_ctree(struct super_block *sb,
1512 struct btrfs_fs_devices *fs_devices,
1513 char *options)
1514 {
1515 u32 sectorsize;
1516 u32 nodesize;
1517 u32 leafsize;
1518 u32 blocksize;
1519 u32 stripesize;
1520 u64 generation;
1521 u64 features;
1522 struct btrfs_key location;
1523 struct buffer_head *bh;
1524 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1525 GFP_NOFS);
1526 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1527 GFP_NOFS);
1528 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1529 GFP_NOFS);
1530 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1531 GFP_NOFS);
1532 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1533 GFP_NOFS);
1534 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1535 GFP_NOFS);
1536 struct btrfs_root *log_tree_root;
1537
1538 int ret;
1539 int err = -EINVAL;
1540
1541 struct btrfs_super_block *disk_super;
1542
1543 if (!extent_root || !tree_root || !fs_info ||
1544 !chunk_root || !dev_root || !csum_root) {
1545 err = -ENOMEM;
1546 goto fail;
1547 }
1548 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1549 INIT_LIST_HEAD(&fs_info->trans_list);
1550 INIT_LIST_HEAD(&fs_info->dead_roots);
1551 INIT_LIST_HEAD(&fs_info->hashers);
1552 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1553 INIT_LIST_HEAD(&fs_info->ordered_operations);
1554 spin_lock_init(&fs_info->delalloc_lock);
1555 spin_lock_init(&fs_info->new_trans_lock);
1556 spin_lock_init(&fs_info->ref_cache_lock);
1557
1558 init_completion(&fs_info->kobj_unregister);
1559 fs_info->tree_root = tree_root;
1560 fs_info->extent_root = extent_root;
1561 fs_info->csum_root = csum_root;
1562 fs_info->chunk_root = chunk_root;
1563 fs_info->dev_root = dev_root;
1564 fs_info->fs_devices = fs_devices;
1565 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1566 INIT_LIST_HEAD(&fs_info->space_info);
1567 btrfs_mapping_init(&fs_info->mapping_tree);
1568 atomic_set(&fs_info->nr_async_submits, 0);
1569 atomic_set(&fs_info->async_delalloc_pages, 0);
1570 atomic_set(&fs_info->async_submit_draining, 0);
1571 atomic_set(&fs_info->nr_async_bios, 0);
1572 atomic_set(&fs_info->throttles, 0);
1573 atomic_set(&fs_info->throttle_gen, 0);
1574 fs_info->sb = sb;
1575 fs_info->max_extent = (u64)-1;
1576 fs_info->max_inline = 8192 * 1024;
1577 setup_bdi(fs_info, &fs_info->bdi);
1578 fs_info->btree_inode = new_inode(sb);
1579 fs_info->btree_inode->i_ino = 1;
1580 fs_info->btree_inode->i_nlink = 1;
1581 fs_info->metadata_ratio = 8;
1582
1583 fs_info->thread_pool_size = min_t(unsigned long,
1584 num_online_cpus() + 2, 8);
1585
1586 INIT_LIST_HEAD(&fs_info->ordered_extents);
1587 spin_lock_init(&fs_info->ordered_extent_lock);
1588
1589 sb->s_blocksize = 4096;
1590 sb->s_blocksize_bits = blksize_bits(4096);
1591
1592 /*
1593 * we set the i_size on the btree inode to the max possible int.
1594 * the real end of the address space is determined by all of
1595 * the devices in the system
1596 */
1597 fs_info->btree_inode->i_size = OFFSET_MAX;
1598 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1599 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1600
1601 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1602 fs_info->btree_inode->i_mapping,
1603 GFP_NOFS);
1604 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1605 GFP_NOFS);
1606
1607 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1608
1609 spin_lock_init(&fs_info->block_group_cache_lock);
1610 fs_info->block_group_cache_tree.rb_node = NULL;
1611
1612 extent_io_tree_init(&fs_info->pinned_extents,
1613 fs_info->btree_inode->i_mapping, GFP_NOFS);
1614 fs_info->do_barriers = 1;
1615
1616 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1617 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1618 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1619
1620 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1621 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1622 sizeof(struct btrfs_key));
1623 insert_inode_hash(fs_info->btree_inode);
1624
1625 mutex_init(&fs_info->trans_mutex);
1626 mutex_init(&fs_info->ordered_operations_mutex);
1627 mutex_init(&fs_info->tree_log_mutex);
1628 mutex_init(&fs_info->drop_mutex);
1629 mutex_init(&fs_info->chunk_mutex);
1630 mutex_init(&fs_info->transaction_kthread_mutex);
1631 mutex_init(&fs_info->cleaner_mutex);
1632 mutex_init(&fs_info->volume_mutex);
1633 mutex_init(&fs_info->tree_reloc_mutex);
1634
1635 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1636 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1637
1638 init_waitqueue_head(&fs_info->transaction_throttle);
1639 init_waitqueue_head(&fs_info->transaction_wait);
1640 init_waitqueue_head(&fs_info->async_submit_wait);
1641
1642 __setup_root(4096, 4096, 4096, 4096, tree_root,
1643 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1644
1645
1646 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1647 if (!bh)
1648 goto fail_iput;
1649
1650 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1651 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1652 sizeof(fs_info->super_for_commit));
1653 brelse(bh);
1654
1655 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1656
1657 disk_super = &fs_info->super_copy;
1658 if (!btrfs_super_root(disk_super))
1659 goto fail_iput;
1660
1661 ret = btrfs_parse_options(tree_root, options);
1662 if (ret) {
1663 err = ret;
1664 goto fail_iput;
1665 }
1666
1667 features = btrfs_super_incompat_flags(disk_super) &
1668 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1669 if (features) {
1670 printk(KERN_ERR "BTRFS: couldn't mount because of "
1671 "unsupported optional features (%Lx).\n",
1672 (unsigned long long)features);
1673 err = -EINVAL;
1674 goto fail_iput;
1675 }
1676
1677 features = btrfs_super_compat_ro_flags(disk_super) &
1678 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1679 if (!(sb->s_flags & MS_RDONLY) && features) {
1680 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1681 "unsupported option features (%Lx).\n",
1682 (unsigned long long)features);
1683 err = -EINVAL;
1684 goto fail_iput;
1685 }
1686
1687 /*
1688 * we need to start all the end_io workers up front because the
1689 * queue work function gets called at interrupt time, and so it
1690 * cannot dynamically grow.
1691 */
1692 btrfs_init_workers(&fs_info->workers, "worker",
1693 fs_info->thread_pool_size);
1694
1695 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1696 fs_info->thread_pool_size);
1697
1698 btrfs_init_workers(&fs_info->submit_workers, "submit",
1699 min_t(u64, fs_devices->num_devices,
1700 fs_info->thread_pool_size));
1701
1702 /* a higher idle thresh on the submit workers makes it much more
1703 * likely that bios will be send down in a sane order to the
1704 * devices
1705 */
1706 fs_info->submit_workers.idle_thresh = 64;
1707
1708 fs_info->workers.idle_thresh = 16;
1709 fs_info->workers.ordered = 1;
1710
1711 fs_info->delalloc_workers.idle_thresh = 2;
1712 fs_info->delalloc_workers.ordered = 1;
1713
1714 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1715 btrfs_init_workers(&fs_info->endio_workers, "endio",
1716 fs_info->thread_pool_size);
1717 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1718 fs_info->thread_pool_size);
1719 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1720 "endio-meta-write", fs_info->thread_pool_size);
1721 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1722 fs_info->thread_pool_size);
1723
1724 /*
1725 * endios are largely parallel and should have a very
1726 * low idle thresh
1727 */
1728 fs_info->endio_workers.idle_thresh = 4;
1729 fs_info->endio_meta_workers.idle_thresh = 4;
1730
1731 fs_info->endio_write_workers.idle_thresh = 64;
1732 fs_info->endio_meta_write_workers.idle_thresh = 64;
1733
1734 btrfs_start_workers(&fs_info->workers, 1);
1735 btrfs_start_workers(&fs_info->submit_workers, 1);
1736 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1737 btrfs_start_workers(&fs_info->fixup_workers, 1);
1738 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1739 btrfs_start_workers(&fs_info->endio_meta_workers,
1740 fs_info->thread_pool_size);
1741 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1742 fs_info->thread_pool_size);
1743 btrfs_start_workers(&fs_info->endio_write_workers,
1744 fs_info->thread_pool_size);
1745
1746 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1747 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1748 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1749
1750 nodesize = btrfs_super_nodesize(disk_super);
1751 leafsize = btrfs_super_leafsize(disk_super);
1752 sectorsize = btrfs_super_sectorsize(disk_super);
1753 stripesize = btrfs_super_stripesize(disk_super);
1754 tree_root->nodesize = nodesize;
1755 tree_root->leafsize = leafsize;
1756 tree_root->sectorsize = sectorsize;
1757 tree_root->stripesize = stripesize;
1758
1759 sb->s_blocksize = sectorsize;
1760 sb->s_blocksize_bits = blksize_bits(sectorsize);
1761
1762 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1763 sizeof(disk_super->magic))) {
1764 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1765 goto fail_sb_buffer;
1766 }
1767
1768 mutex_lock(&fs_info->chunk_mutex);
1769 ret = btrfs_read_sys_array(tree_root);
1770 mutex_unlock(&fs_info->chunk_mutex);
1771 if (ret) {
1772 printk(KERN_WARNING "btrfs: failed to read the system "
1773 "array on %s\n", sb->s_id);
1774 goto fail_sys_array;
1775 }
1776
1777 blocksize = btrfs_level_size(tree_root,
1778 btrfs_super_chunk_root_level(disk_super));
1779 generation = btrfs_super_chunk_root_generation(disk_super);
1780
1781 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1782 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1783
1784 chunk_root->node = read_tree_block(chunk_root,
1785 btrfs_super_chunk_root(disk_super),
1786 blocksize, generation);
1787 BUG_ON(!chunk_root->node);
1788
1789 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1790 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1791 BTRFS_UUID_SIZE);
1792
1793 mutex_lock(&fs_info->chunk_mutex);
1794 ret = btrfs_read_chunk_tree(chunk_root);
1795 mutex_unlock(&fs_info->chunk_mutex);
1796 if (ret) {
1797 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1798 sb->s_id);
1799 goto fail_chunk_root;
1800 }
1801
1802 btrfs_close_extra_devices(fs_devices);
1803
1804 blocksize = btrfs_level_size(tree_root,
1805 btrfs_super_root_level(disk_super));
1806 generation = btrfs_super_generation(disk_super);
1807
1808 tree_root->node = read_tree_block(tree_root,
1809 btrfs_super_root(disk_super),
1810 blocksize, generation);
1811 if (!tree_root->node)
1812 goto fail_chunk_root;
1813
1814
1815 ret = find_and_setup_root(tree_root, fs_info,
1816 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1817 if (ret)
1818 goto fail_tree_root;
1819 extent_root->track_dirty = 1;
1820
1821 ret = find_and_setup_root(tree_root, fs_info,
1822 BTRFS_DEV_TREE_OBJECTID, dev_root);
1823 dev_root->track_dirty = 1;
1824 if (ret)
1825 goto fail_extent_root;
1826
1827 ret = find_and_setup_root(tree_root, fs_info,
1828 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1829 if (ret)
1830 goto fail_extent_root;
1831
1832 csum_root->track_dirty = 1;
1833
1834 btrfs_read_block_groups(extent_root);
1835
1836 fs_info->generation = generation;
1837 fs_info->last_trans_committed = generation;
1838 fs_info->data_alloc_profile = (u64)-1;
1839 fs_info->metadata_alloc_profile = (u64)-1;
1840 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1841 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1842 "btrfs-cleaner");
1843 if (IS_ERR(fs_info->cleaner_kthread))
1844 goto fail_csum_root;
1845
1846 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1847 tree_root,
1848 "btrfs-transaction");
1849 if (IS_ERR(fs_info->transaction_kthread))
1850 goto fail_cleaner;
1851
1852 if (btrfs_super_log_root(disk_super) != 0) {
1853 u64 bytenr = btrfs_super_log_root(disk_super);
1854
1855 if (fs_devices->rw_devices == 0) {
1856 printk(KERN_WARNING "Btrfs log replay required "
1857 "on RO media\n");
1858 err = -EIO;
1859 goto fail_trans_kthread;
1860 }
1861 blocksize =
1862 btrfs_level_size(tree_root,
1863 btrfs_super_log_root_level(disk_super));
1864
1865 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1866 GFP_NOFS);
1867
1868 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1869 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1870
1871 log_tree_root->node = read_tree_block(tree_root, bytenr,
1872 blocksize,
1873 generation + 1);
1874 ret = btrfs_recover_log_trees(log_tree_root);
1875 BUG_ON(ret);
1876
1877 if (sb->s_flags & MS_RDONLY) {
1878 ret = btrfs_commit_super(tree_root);
1879 BUG_ON(ret);
1880 }
1881 }
1882
1883 if (!(sb->s_flags & MS_RDONLY)) {
1884 ret = btrfs_cleanup_reloc_trees(tree_root);
1885 BUG_ON(ret);
1886 }
1887
1888 location.objectid = BTRFS_FS_TREE_OBJECTID;
1889 location.type = BTRFS_ROOT_ITEM_KEY;
1890 location.offset = (u64)-1;
1891
1892 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1893 if (!fs_info->fs_root)
1894 goto fail_trans_kthread;
1895 return tree_root;
1896
1897 fail_trans_kthread:
1898 kthread_stop(fs_info->transaction_kthread);
1899 fail_cleaner:
1900 kthread_stop(fs_info->cleaner_kthread);
1901
1902 /*
1903 * make sure we're done with the btree inode before we stop our
1904 * kthreads
1905 */
1906 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1907 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1908
1909 fail_csum_root:
1910 free_extent_buffer(csum_root->node);
1911 fail_extent_root:
1912 free_extent_buffer(extent_root->node);
1913 fail_tree_root:
1914 free_extent_buffer(tree_root->node);
1915 fail_chunk_root:
1916 free_extent_buffer(chunk_root->node);
1917 fail_sys_array:
1918 free_extent_buffer(dev_root->node);
1919 fail_sb_buffer:
1920 btrfs_stop_workers(&fs_info->fixup_workers);
1921 btrfs_stop_workers(&fs_info->delalloc_workers);
1922 btrfs_stop_workers(&fs_info->workers);
1923 btrfs_stop_workers(&fs_info->endio_workers);
1924 btrfs_stop_workers(&fs_info->endio_meta_workers);
1925 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1926 btrfs_stop_workers(&fs_info->endio_write_workers);
1927 btrfs_stop_workers(&fs_info->submit_workers);
1928 fail_iput:
1929 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1930 iput(fs_info->btree_inode);
1931
1932 btrfs_close_devices(fs_info->fs_devices);
1933 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1934 bdi_destroy(&fs_info->bdi);
1935
1936 fail:
1937 kfree(extent_root);
1938 kfree(tree_root);
1939 kfree(fs_info);
1940 kfree(chunk_root);
1941 kfree(dev_root);
1942 kfree(csum_root);
1943 return ERR_PTR(err);
1944 }
1945
1946 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1947 {
1948 char b[BDEVNAME_SIZE];
1949
1950 if (uptodate) {
1951 set_buffer_uptodate(bh);
1952 } else {
1953 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1954 printk(KERN_WARNING "lost page write due to "
1955 "I/O error on %s\n",
1956 bdevname(bh->b_bdev, b));
1957 }
1958 /* note, we dont' set_buffer_write_io_error because we have
1959 * our own ways of dealing with the IO errors
1960 */
1961 clear_buffer_uptodate(bh);
1962 }
1963 unlock_buffer(bh);
1964 put_bh(bh);
1965 }
1966
1967 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1968 {
1969 struct buffer_head *bh;
1970 struct buffer_head *latest = NULL;
1971 struct btrfs_super_block *super;
1972 int i;
1973 u64 transid = 0;
1974 u64 bytenr;
1975
1976 /* we would like to check all the supers, but that would make
1977 * a btrfs mount succeed after a mkfs from a different FS.
1978 * So, we need to add a special mount option to scan for
1979 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1980 */
1981 for (i = 0; i < 1; i++) {
1982 bytenr = btrfs_sb_offset(i);
1983 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1984 break;
1985 bh = __bread(bdev, bytenr / 4096, 4096);
1986 if (!bh)
1987 continue;
1988
1989 super = (struct btrfs_super_block *)bh->b_data;
1990 if (btrfs_super_bytenr(super) != bytenr ||
1991 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1992 sizeof(super->magic))) {
1993 brelse(bh);
1994 continue;
1995 }
1996
1997 if (!latest || btrfs_super_generation(super) > transid) {
1998 brelse(latest);
1999 latest = bh;
2000 transid = btrfs_super_generation(super);
2001 } else {
2002 brelse(bh);
2003 }
2004 }
2005 return latest;
2006 }
2007
2008 static int write_dev_supers(struct btrfs_device *device,
2009 struct btrfs_super_block *sb,
2010 int do_barriers, int wait, int max_mirrors)
2011 {
2012 struct buffer_head *bh;
2013 int i;
2014 int ret;
2015 int errors = 0;
2016 u32 crc;
2017 u64 bytenr;
2018 int last_barrier = 0;
2019
2020 if (max_mirrors == 0)
2021 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2022
2023 /* make sure only the last submit_bh does a barrier */
2024 if (do_barriers) {
2025 for (i = 0; i < max_mirrors; i++) {
2026 bytenr = btrfs_sb_offset(i);
2027 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2028 device->total_bytes)
2029 break;
2030 last_barrier = i;
2031 }
2032 }
2033
2034 for (i = 0; i < max_mirrors; i++) {
2035 bytenr = btrfs_sb_offset(i);
2036 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2037 break;
2038
2039 if (wait) {
2040 bh = __find_get_block(device->bdev, bytenr / 4096,
2041 BTRFS_SUPER_INFO_SIZE);
2042 BUG_ON(!bh);
2043 brelse(bh);
2044 wait_on_buffer(bh);
2045 if (buffer_uptodate(bh)) {
2046 brelse(bh);
2047 continue;
2048 }
2049 } else {
2050 btrfs_set_super_bytenr(sb, bytenr);
2051
2052 crc = ~(u32)0;
2053 crc = btrfs_csum_data(NULL, (char *)sb +
2054 BTRFS_CSUM_SIZE, crc,
2055 BTRFS_SUPER_INFO_SIZE -
2056 BTRFS_CSUM_SIZE);
2057 btrfs_csum_final(crc, sb->csum);
2058
2059 bh = __getblk(device->bdev, bytenr / 4096,
2060 BTRFS_SUPER_INFO_SIZE);
2061 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2062
2063 set_buffer_uptodate(bh);
2064 get_bh(bh);
2065 lock_buffer(bh);
2066 bh->b_end_io = btrfs_end_buffer_write_sync;
2067 }
2068
2069 if (i == last_barrier && do_barriers && device->barriers) {
2070 ret = submit_bh(WRITE_BARRIER, bh);
2071 if (ret == -EOPNOTSUPP) {
2072 printk("btrfs: disabling barriers on dev %s\n",
2073 device->name);
2074 set_buffer_uptodate(bh);
2075 device->barriers = 0;
2076 get_bh(bh);
2077 lock_buffer(bh);
2078 ret = submit_bh(WRITE_SYNC, bh);
2079 }
2080 } else {
2081 ret = submit_bh(WRITE_SYNC, bh);
2082 }
2083
2084 if (!ret && wait) {
2085 wait_on_buffer(bh);
2086 if (!buffer_uptodate(bh))
2087 errors++;
2088 } else if (ret) {
2089 errors++;
2090 }
2091 if (wait)
2092 brelse(bh);
2093 }
2094 return errors < i ? 0 : -1;
2095 }
2096
2097 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2098 {
2099 struct list_head *head = &root->fs_info->fs_devices->devices;
2100 struct btrfs_device *dev;
2101 struct btrfs_super_block *sb;
2102 struct btrfs_dev_item *dev_item;
2103 int ret;
2104 int do_barriers;
2105 int max_errors;
2106 int total_errors = 0;
2107 u64 flags;
2108
2109 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2110 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2111
2112 sb = &root->fs_info->super_for_commit;
2113 dev_item = &sb->dev_item;
2114 list_for_each_entry(dev, head, dev_list) {
2115 if (!dev->bdev) {
2116 total_errors++;
2117 continue;
2118 }
2119 if (!dev->in_fs_metadata || !dev->writeable)
2120 continue;
2121
2122 btrfs_set_stack_device_generation(dev_item, 0);
2123 btrfs_set_stack_device_type(dev_item, dev->type);
2124 btrfs_set_stack_device_id(dev_item, dev->devid);
2125 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2126 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2127 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2128 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2129 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2130 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2131 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2132
2133 flags = btrfs_super_flags(sb);
2134 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2135
2136 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2137 if (ret)
2138 total_errors++;
2139 }
2140 if (total_errors > max_errors) {
2141 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2142 total_errors);
2143 BUG();
2144 }
2145
2146 total_errors = 0;
2147 list_for_each_entry(dev, head, dev_list) {
2148 if (!dev->bdev)
2149 continue;
2150 if (!dev->in_fs_metadata || !dev->writeable)
2151 continue;
2152
2153 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2154 if (ret)
2155 total_errors++;
2156 }
2157 if (total_errors > max_errors) {
2158 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2159 total_errors);
2160 BUG();
2161 }
2162 return 0;
2163 }
2164
2165 int write_ctree_super(struct btrfs_trans_handle *trans,
2166 struct btrfs_root *root, int max_mirrors)
2167 {
2168 int ret;
2169
2170 ret = write_all_supers(root, max_mirrors);
2171 return ret;
2172 }
2173
2174 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2175 {
2176 radix_tree_delete(&fs_info->fs_roots_radix,
2177 (unsigned long)root->root_key.objectid);
2178 if (root->anon_super.s_dev) {
2179 down_write(&root->anon_super.s_umount);
2180 kill_anon_super(&root->anon_super);
2181 }
2182 if (root->node)
2183 free_extent_buffer(root->node);
2184 if (root->commit_root)
2185 free_extent_buffer(root->commit_root);
2186 kfree(root->name);
2187 kfree(root);
2188 return 0;
2189 }
2190
2191 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2192 {
2193 int ret;
2194 struct btrfs_root *gang[8];
2195 int i;
2196
2197 while (1) {
2198 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2199 (void **)gang, 0,
2200 ARRAY_SIZE(gang));
2201 if (!ret)
2202 break;
2203 for (i = 0; i < ret; i++)
2204 btrfs_free_fs_root(fs_info, gang[i]);
2205 }
2206 return 0;
2207 }
2208
2209 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2210 {
2211 u64 root_objectid = 0;
2212 struct btrfs_root *gang[8];
2213 int i;
2214 int ret;
2215
2216 while (1) {
2217 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2218 (void **)gang, root_objectid,
2219 ARRAY_SIZE(gang));
2220 if (!ret)
2221 break;
2222 for (i = 0; i < ret; i++) {
2223 root_objectid = gang[i]->root_key.objectid;
2224 ret = btrfs_find_dead_roots(fs_info->tree_root,
2225 root_objectid, gang[i]);
2226 BUG_ON(ret);
2227 btrfs_orphan_cleanup(gang[i]);
2228 }
2229 root_objectid++;
2230 }
2231 return 0;
2232 }
2233
2234 int btrfs_commit_super(struct btrfs_root *root)
2235 {
2236 struct btrfs_trans_handle *trans;
2237 int ret;
2238
2239 mutex_lock(&root->fs_info->cleaner_mutex);
2240 btrfs_clean_old_snapshots(root);
2241 mutex_unlock(&root->fs_info->cleaner_mutex);
2242 trans = btrfs_start_transaction(root, 1);
2243 ret = btrfs_commit_transaction(trans, root);
2244 BUG_ON(ret);
2245 /* run commit again to drop the original snapshot */
2246 trans = btrfs_start_transaction(root, 1);
2247 btrfs_commit_transaction(trans, root);
2248 ret = btrfs_write_and_wait_transaction(NULL, root);
2249 BUG_ON(ret);
2250
2251 ret = write_ctree_super(NULL, root, 0);
2252 return ret;
2253 }
2254
2255 int close_ctree(struct btrfs_root *root)
2256 {
2257 struct btrfs_fs_info *fs_info = root->fs_info;
2258 int ret;
2259
2260 fs_info->closing = 1;
2261 smp_mb();
2262
2263 kthread_stop(root->fs_info->transaction_kthread);
2264 kthread_stop(root->fs_info->cleaner_kthread);
2265
2266 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2267 ret = btrfs_commit_super(root);
2268 if (ret)
2269 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2270 }
2271
2272 if (fs_info->delalloc_bytes) {
2273 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2274 (unsigned long long)fs_info->delalloc_bytes);
2275 }
2276 if (fs_info->total_ref_cache_size) {
2277 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2278 (unsigned long long)fs_info->total_ref_cache_size);
2279 }
2280
2281 if (fs_info->extent_root->node)
2282 free_extent_buffer(fs_info->extent_root->node);
2283
2284 if (fs_info->tree_root->node)
2285 free_extent_buffer(fs_info->tree_root->node);
2286
2287 if (root->fs_info->chunk_root->node)
2288 free_extent_buffer(root->fs_info->chunk_root->node);
2289
2290 if (root->fs_info->dev_root->node)
2291 free_extent_buffer(root->fs_info->dev_root->node);
2292
2293 if (root->fs_info->csum_root->node)
2294 free_extent_buffer(root->fs_info->csum_root->node);
2295
2296 btrfs_free_block_groups(root->fs_info);
2297
2298 del_fs_roots(fs_info);
2299
2300 iput(fs_info->btree_inode);
2301
2302 btrfs_stop_workers(&fs_info->fixup_workers);
2303 btrfs_stop_workers(&fs_info->delalloc_workers);
2304 btrfs_stop_workers(&fs_info->workers);
2305 btrfs_stop_workers(&fs_info->endio_workers);
2306 btrfs_stop_workers(&fs_info->endio_meta_workers);
2307 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2308 btrfs_stop_workers(&fs_info->endio_write_workers);
2309 btrfs_stop_workers(&fs_info->submit_workers);
2310
2311 btrfs_close_devices(fs_info->fs_devices);
2312 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2313
2314 bdi_destroy(&fs_info->bdi);
2315
2316 kfree(fs_info->extent_root);
2317 kfree(fs_info->tree_root);
2318 kfree(fs_info->chunk_root);
2319 kfree(fs_info->dev_root);
2320 kfree(fs_info->csum_root);
2321 return 0;
2322 }
2323
2324 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2325 {
2326 int ret;
2327 struct inode *btree_inode = buf->first_page->mapping->host;
2328
2329 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2330 if (!ret)
2331 return ret;
2332
2333 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2334 parent_transid);
2335 return !ret;
2336 }
2337
2338 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2339 {
2340 struct inode *btree_inode = buf->first_page->mapping->host;
2341 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2342 buf);
2343 }
2344
2345 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2346 {
2347 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2348 u64 transid = btrfs_header_generation(buf);
2349 struct inode *btree_inode = root->fs_info->btree_inode;
2350 int was_dirty;
2351
2352 btrfs_assert_tree_locked(buf);
2353 if (transid != root->fs_info->generation) {
2354 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2355 "found %llu running %llu\n",
2356 (unsigned long long)buf->start,
2357 (unsigned long long)transid,
2358 (unsigned long long)root->fs_info->generation);
2359 WARN_ON(1);
2360 }
2361 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2362 buf);
2363 if (!was_dirty) {
2364 spin_lock(&root->fs_info->delalloc_lock);
2365 root->fs_info->dirty_metadata_bytes += buf->len;
2366 spin_unlock(&root->fs_info->delalloc_lock);
2367 }
2368 }
2369
2370 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2371 {
2372 /*
2373 * looks as though older kernels can get into trouble with
2374 * this code, they end up stuck in balance_dirty_pages forever
2375 */
2376 struct extent_io_tree *tree;
2377 u64 num_dirty;
2378 u64 start = 0;
2379 unsigned long thresh = 32 * 1024 * 1024;
2380 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2381
2382 if (current->flags & PF_MEMALLOC)
2383 return;
2384
2385 num_dirty = count_range_bits(tree, &start, (u64)-1,
2386 thresh, EXTENT_DIRTY);
2387 if (num_dirty > thresh) {
2388 balance_dirty_pages_ratelimited_nr(
2389 root->fs_info->btree_inode->i_mapping, 1);
2390 }
2391 return;
2392 }
2393
2394 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2395 {
2396 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2397 int ret;
2398 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2399 if (ret == 0)
2400 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2401 return ret;
2402 }
2403
2404 int btree_lock_page_hook(struct page *page)
2405 {
2406 struct inode *inode = page->mapping->host;
2407 struct btrfs_root *root = BTRFS_I(inode)->root;
2408 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2409 struct extent_buffer *eb;
2410 unsigned long len;
2411 u64 bytenr = page_offset(page);
2412
2413 if (page->private == EXTENT_PAGE_PRIVATE)
2414 goto out;
2415
2416 len = page->private >> 2;
2417 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2418 if (!eb)
2419 goto out;
2420
2421 btrfs_tree_lock(eb);
2422 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2423
2424 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2425 spin_lock(&root->fs_info->delalloc_lock);
2426 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2427 root->fs_info->dirty_metadata_bytes -= eb->len;
2428 else
2429 WARN_ON(1);
2430 spin_unlock(&root->fs_info->delalloc_lock);
2431 }
2432
2433 btrfs_tree_unlock(eb);
2434 free_extent_buffer(eb);
2435 out:
2436 lock_page(page);
2437 return 0;
2438 }
2439
2440 static struct extent_io_ops btree_extent_io_ops = {
2441 .write_cache_pages_lock_hook = btree_lock_page_hook,
2442 .readpage_end_io_hook = btree_readpage_end_io_hook,
2443 .submit_bio_hook = btree_submit_bio_hook,
2444 /* note we're sharing with inode.c for the merge bio hook */
2445 .merge_bio_hook = btrfs_merge_bio_hook,
2446 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree