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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[linux-2.6/cjktty.git] / fs / btrfs / disk-io.c
blob92d73929d3814b50024196eb5e8688d2ee330222
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
42 static struct extent_io_ops btree_extent_io_ops;
43 static void end_workqueue_fn(struct btrfs_work *work);
44
45 /*
46 * end_io_wq structs are used to do processing in task context when an IO is
47 * complete. This is used during reads to verify checksums, and it is used
48 * by writes to insert metadata for new file extents after IO is complete.
49 */
50 struct end_io_wq {
51 struct bio *bio;
52 bio_end_io_t *end_io;
53 void *private;
54 struct btrfs_fs_info *info;
55 int error;
56 int metadata;
57 struct list_head list;
58 struct btrfs_work work;
59 };
60
61 /*
62 * async submit bios are used to offload expensive checksumming
63 * onto the worker threads. They checksum file and metadata bios
64 * just before they are sent down the IO stack.
65 */
66 struct async_submit_bio {
67 struct inode *inode;
68 struct bio *bio;
69 struct list_head list;
70 extent_submit_bio_hook_t *submit_bio_start;
71 extent_submit_bio_hook_t *submit_bio_done;
72 int rw;
73 int mirror_num;
74 unsigned long bio_flags;
75 struct btrfs_work work;
76 };
77
78 /* These are used to set the lockdep class on the extent buffer locks.
79 * The class is set by the readpage_end_io_hook after the buffer has
80 * passed csum validation but before the pages are unlocked.
81 *
82 * The lockdep class is also set by btrfs_init_new_buffer on freshly
83 * allocated blocks.
84 *
85 * The class is based on the level in the tree block, which allows lockdep
86 * to know that lower nodes nest inside the locks of higher nodes.
87 *
88 * We also add a check to make sure the highest level of the tree is
89 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
90 * code needs update as well.
91 */
92 #ifdef CONFIG_DEBUG_LOCK_ALLOC
93 # if BTRFS_MAX_LEVEL != 8
94 # error
95 # endif
96 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
97 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
98 /* leaf */
99 "btrfs-extent-00",
100 "btrfs-extent-01",
101 "btrfs-extent-02",
102 "btrfs-extent-03",
103 "btrfs-extent-04",
104 "btrfs-extent-05",
105 "btrfs-extent-06",
106 "btrfs-extent-07",
107 /* highest possible level */
108 "btrfs-extent-08",
109 };
110 #endif
111
112 /*
113 * extents on the btree inode are pretty simple, there's one extent
114 * that covers the entire device
115 */
116 static struct extent_map *btree_get_extent(struct inode *inode,
117 struct page *page, size_t page_offset, u64 start, u64 len,
118 int create)
119 {
120 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
121 struct extent_map *em;
122 int ret;
123
124 spin_lock(&em_tree->lock);
125 em = lookup_extent_mapping(em_tree, start, len);
126 if (em) {
127 em->bdev =
128 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
129 spin_unlock(&em_tree->lock);
130 goto out;
131 }
132 spin_unlock(&em_tree->lock);
133
134 em = alloc_extent_map(GFP_NOFS);
135 if (!em) {
136 em = ERR_PTR(-ENOMEM);
137 goto out;
138 }
139 em->start = 0;
140 em->len = (u64)-1;
141 em->block_len = (u64)-1;
142 em->block_start = 0;
143 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
144
145 spin_lock(&em_tree->lock);
146 ret = add_extent_mapping(em_tree, em);
147 if (ret == -EEXIST) {
148 u64 failed_start = em->start;
149 u64 failed_len = em->len;
150
151 free_extent_map(em);
152 em = lookup_extent_mapping(em_tree, start, len);
153 if (em) {
154 ret = 0;
155 } else {
156 em = lookup_extent_mapping(em_tree, failed_start,
157 failed_len);
158 ret = -EIO;
159 }
160 } else if (ret) {
161 free_extent_map(em);
162 em = NULL;
163 }
164 spin_unlock(&em_tree->lock);
165
166 if (ret)
167 em = ERR_PTR(ret);
168 out:
169 return em;
170 }
171
172 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
173 {
174 return btrfs_crc32c(seed, data, len);
175 }
176
177 void btrfs_csum_final(u32 crc, char *result)
178 {
179 *(__le32 *)result = ~cpu_to_le32(crc);
180 }
181
182 /*
183 * compute the csum for a btree block, and either verify it or write it
184 * into the csum field of the block.
185 */
186 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
187 int verify)
188 {
189 u16 csum_size =
190 btrfs_super_csum_size(&root->fs_info->super_copy);
191 char *result = NULL;
192 unsigned long len;
193 unsigned long cur_len;
194 unsigned long offset = BTRFS_CSUM_SIZE;
195 char *map_token = NULL;
196 char *kaddr;
197 unsigned long map_start;
198 unsigned long map_len;
199 int err;
200 u32 crc = ~(u32)0;
201 unsigned long inline_result;
202
203 len = buf->len - offset;
204 while (len > 0) {
205 err = map_private_extent_buffer(buf, offset, 32,
206 &map_token, &kaddr,
207 &map_start, &map_len, KM_USER0);
208 if (err)
209 return 1;
210 cur_len = min(len, map_len - (offset - map_start));
211 crc = btrfs_csum_data(root, kaddr + offset - map_start,
212 crc, cur_len);
213 len -= cur_len;
214 offset += cur_len;
215 unmap_extent_buffer(buf, map_token, KM_USER0);
216 }
217 if (csum_size > sizeof(inline_result)) {
218 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
219 if (!result)
220 return 1;
221 } else {
222 result = (char *)&inline_result;
223 }
224
225 btrfs_csum_final(crc, result);
226
227 if (verify) {
228 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
229 u32 val;
230 u32 found = 0;
231 memcpy(&found, result, csum_size);
232
233 read_extent_buffer(buf, &val, 0, csum_size);
234 printk(KERN_INFO "btrfs: %s checksum verify failed "
235 "on %llu wanted %X found %X level %d\n",
236 root->fs_info->sb->s_id,
237 buf->start, val, found, btrfs_header_level(buf));
238 if (result != (char *)&inline_result)
239 kfree(result);
240 return 1;
241 }
242 } else {
243 write_extent_buffer(buf, result, 0, csum_size);
244 }
245 if (result != (char *)&inline_result)
246 kfree(result);
247 return 0;
248 }
249
250 /*
251 * we can't consider a given block up to date unless the transid of the
252 * block matches the transid in the parent node's pointer. This is how we
253 * detect blocks that either didn't get written at all or got written
254 * in the wrong place.
255 */
256 static int verify_parent_transid(struct extent_io_tree *io_tree,
257 struct extent_buffer *eb, u64 parent_transid)
258 {
259 int ret;
260
261 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
262 return 0;
263
264 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
265 if (extent_buffer_uptodate(io_tree, eb) &&
266 btrfs_header_generation(eb) == parent_transid) {
267 ret = 0;
268 goto out;
269 }
270 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
271 (unsigned long long)eb->start,
272 (unsigned long long)parent_transid,
273 (unsigned long long)btrfs_header_generation(eb));
274 ret = 1;
275 clear_extent_buffer_uptodate(io_tree, eb);
276 out:
277 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
278 GFP_NOFS);
279 return ret;
280 }
281
282 /*
283 * helper to read a given tree block, doing retries as required when
284 * the checksums don't match and we have alternate mirrors to try.
285 */
286 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
287 struct extent_buffer *eb,
288 u64 start, u64 parent_transid)
289 {
290 struct extent_io_tree *io_tree;
291 int ret;
292 int num_copies = 0;
293 int mirror_num = 0;
294
295 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
296 while (1) {
297 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
298 btree_get_extent, mirror_num);
299 if (!ret &&
300 !verify_parent_transid(io_tree, eb, parent_transid))
301 return ret;
302
303 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
304 eb->start, eb->len);
305 if (num_copies == 1)
306 return ret;
307
308 mirror_num++;
309 if (mirror_num > num_copies)
310 return ret;
311 }
312 return -EIO;
313 }
314
315 /*
316 * checksum a dirty tree block before IO. This has extra checks to make sure
317 * we only fill in the checksum field in the first page of a multi-page block
318 */
319
320 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
321 {
322 struct extent_io_tree *tree;
323 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
324 u64 found_start;
325 int found_level;
326 unsigned long len;
327 struct extent_buffer *eb;
328 int ret;
329
330 tree = &BTRFS_I(page->mapping->host)->io_tree;
331
332 if (page->private == EXTENT_PAGE_PRIVATE)
333 goto out;
334 if (!page->private)
335 goto out;
336 len = page->private >> 2;
337 WARN_ON(len == 0);
338
339 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
340 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
341 btrfs_header_generation(eb));
342 BUG_ON(ret);
343 found_start = btrfs_header_bytenr(eb);
344 if (found_start != start) {
345 WARN_ON(1);
346 goto err;
347 }
348 if (eb->first_page != page) {
349 WARN_ON(1);
350 goto err;
351 }
352 if (!PageUptodate(page)) {
353 WARN_ON(1);
354 goto err;
355 }
356 found_level = btrfs_header_level(eb);
357
358 csum_tree_block(root, eb, 0);
359 err:
360 free_extent_buffer(eb);
361 out:
362 return 0;
363 }
364
365 static int check_tree_block_fsid(struct btrfs_root *root,
366 struct extent_buffer *eb)
367 {
368 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
369 u8 fsid[BTRFS_UUID_SIZE];
370 int ret = 1;
371
372 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
373 BTRFS_FSID_SIZE);
374 while (fs_devices) {
375 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
376 ret = 0;
377 break;
378 }
379 fs_devices = fs_devices->seed;
380 }
381 return ret;
382 }
383
384 #ifdef CONFIG_DEBUG_LOCK_ALLOC
385 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
386 {
387 lockdep_set_class_and_name(&eb->lock,
388 &btrfs_eb_class[level],
389 btrfs_eb_name[level]);
390 }
391 #endif
392
393 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
394 struct extent_state *state)
395 {
396 struct extent_io_tree *tree;
397 u64 found_start;
398 int found_level;
399 unsigned long len;
400 struct extent_buffer *eb;
401 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
402 int ret = 0;
403
404 tree = &BTRFS_I(page->mapping->host)->io_tree;
405 if (page->private == EXTENT_PAGE_PRIVATE)
406 goto out;
407 if (!page->private)
408 goto out;
409
410 len = page->private >> 2;
411 WARN_ON(len == 0);
412
413 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
414
415 found_start = btrfs_header_bytenr(eb);
416 if (found_start != start) {
417 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n",
418 (unsigned long long)found_start,
419 (unsigned long long)eb->start);
420 ret = -EIO;
421 goto err;
422 }
423 if (eb->first_page != page) {
424 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
425 eb->first_page->index, page->index);
426 WARN_ON(1);
427 ret = -EIO;
428 goto err;
429 }
430 if (check_tree_block_fsid(root, eb)) {
431 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
432 (unsigned long long)eb->start);
433 ret = -EIO;
434 goto err;
435 }
436 found_level = btrfs_header_level(eb);
437
438 btrfs_set_buffer_lockdep_class(eb, found_level);
439
440 ret = csum_tree_block(root, eb, 1);
441 if (ret)
442 ret = -EIO;
443
444 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
445 end = eb->start + end - 1;
446 err:
447 free_extent_buffer(eb);
448 out:
449 return ret;
450 }
451
452 static void end_workqueue_bio(struct bio *bio, int err)
453 {
454 struct end_io_wq *end_io_wq = bio->bi_private;
455 struct btrfs_fs_info *fs_info;
456
457 fs_info = end_io_wq->info;
458 end_io_wq->error = err;
459 end_io_wq->work.func = end_workqueue_fn;
460 end_io_wq->work.flags = 0;
461
462 if (bio->bi_rw & (1 << BIO_RW)) {
463 if (end_io_wq->metadata)
464 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
465 &end_io_wq->work);
466 else
467 btrfs_queue_worker(&fs_info->endio_write_workers,
468 &end_io_wq->work);
469 } else {
470 if (end_io_wq->metadata)
471 btrfs_queue_worker(&fs_info->endio_meta_workers,
472 &end_io_wq->work);
473 else
474 btrfs_queue_worker(&fs_info->endio_workers,
475 &end_io_wq->work);
476 }
477 }
478
479 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
480 int metadata)
481 {
482 struct end_io_wq *end_io_wq;
483 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
484 if (!end_io_wq)
485 return -ENOMEM;
486
487 end_io_wq->private = bio->bi_private;
488 end_io_wq->end_io = bio->bi_end_io;
489 end_io_wq->info = info;
490 end_io_wq->error = 0;
491 end_io_wq->bio = bio;
492 end_io_wq->metadata = metadata;
493
494 bio->bi_private = end_io_wq;
495 bio->bi_end_io = end_workqueue_bio;
496 return 0;
497 }
498
499 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
500 {
501 unsigned long limit = min_t(unsigned long,
502 info->workers.max_workers,
503 info->fs_devices->open_devices);
504 return 256 * limit;
505 }
506
507 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
508 {
509 return atomic_read(&info->nr_async_bios) >
510 btrfs_async_submit_limit(info);
511 }
512
513 static void run_one_async_start(struct btrfs_work *work)
514 {
515 struct btrfs_fs_info *fs_info;
516 struct async_submit_bio *async;
517
518 async = container_of(work, struct async_submit_bio, work);
519 fs_info = BTRFS_I(async->inode)->root->fs_info;
520 async->submit_bio_start(async->inode, async->rw, async->bio,
521 async->mirror_num, async->bio_flags);
522 }
523
524 static void run_one_async_done(struct btrfs_work *work)
525 {
526 struct btrfs_fs_info *fs_info;
527 struct async_submit_bio *async;
528 int limit;
529
530 async = container_of(work, struct async_submit_bio, work);
531 fs_info = BTRFS_I(async->inode)->root->fs_info;
532
533 limit = btrfs_async_submit_limit(fs_info);
534 limit = limit * 2 / 3;
535
536 atomic_dec(&fs_info->nr_async_submits);
537
538 if (atomic_read(&fs_info->nr_async_submits) < limit &&
539 waitqueue_active(&fs_info->async_submit_wait))
540 wake_up(&fs_info->async_submit_wait);
541
542 async->submit_bio_done(async->inode, async->rw, async->bio,
543 async->mirror_num, async->bio_flags);
544 }
545
546 static void run_one_async_free(struct btrfs_work *work)
547 {
548 struct async_submit_bio *async;
549
550 async = container_of(work, struct async_submit_bio, work);
551 kfree(async);
552 }
553
554 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
555 int rw, struct bio *bio, int mirror_num,
556 unsigned long bio_flags,
557 extent_submit_bio_hook_t *submit_bio_start,
558 extent_submit_bio_hook_t *submit_bio_done)
559 {
560 struct async_submit_bio *async;
561
562 async = kmalloc(sizeof(*async), GFP_NOFS);
563 if (!async)
564 return -ENOMEM;
565
566 async->inode = inode;
567 async->rw = rw;
568 async->bio = bio;
569 async->mirror_num = mirror_num;
570 async->submit_bio_start = submit_bio_start;
571 async->submit_bio_done = submit_bio_done;
572
573 async->work.func = run_one_async_start;
574 async->work.ordered_func = run_one_async_done;
575 async->work.ordered_free = run_one_async_free;
576
577 async->work.flags = 0;
578 async->bio_flags = bio_flags;
579
580 atomic_inc(&fs_info->nr_async_submits);
581 btrfs_queue_worker(&fs_info->workers, &async->work);
582 #if 0
583 int limit = btrfs_async_submit_limit(fs_info);
584 if (atomic_read(&fs_info->nr_async_submits) > limit) {
585 wait_event_timeout(fs_info->async_submit_wait,
586 (atomic_read(&fs_info->nr_async_submits) < limit),
587 HZ/10);
588
589 wait_event_timeout(fs_info->async_submit_wait,
590 (atomic_read(&fs_info->nr_async_bios) < limit),
591 HZ/10);
592 }
593 #endif
594 while (atomic_read(&fs_info->async_submit_draining) &&
595 atomic_read(&fs_info->nr_async_submits)) {
596 wait_event(fs_info->async_submit_wait,
597 (atomic_read(&fs_info->nr_async_submits) == 0));
598 }
599
600 return 0;
601 }
602
603 static int btree_csum_one_bio(struct bio *bio)
604 {
605 struct bio_vec *bvec = bio->bi_io_vec;
606 int bio_index = 0;
607 struct btrfs_root *root;
608
609 WARN_ON(bio->bi_vcnt <= 0);
610 while (bio_index < bio->bi_vcnt) {
611 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
612 csum_dirty_buffer(root, bvec->bv_page);
613 bio_index++;
614 bvec++;
615 }
616 return 0;
617 }
618
619 static int __btree_submit_bio_start(struct inode *inode, int rw,
620 struct bio *bio, int mirror_num,
621 unsigned long bio_flags)
622 {
623 /*
624 * when we're called for a write, we're already in the async
625 * submission context. Just jump into btrfs_map_bio
626 */
627 btree_csum_one_bio(bio);
628 return 0;
629 }
630
631 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
632 int mirror_num, unsigned long bio_flags)
633 {
634 /*
635 * when we're called for a write, we're already in the async
636 * submission context. Just jump into btrfs_map_bio
637 */
638 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
639 }
640
641 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
642 int mirror_num, unsigned long bio_flags)
643 {
644 int ret;
645
646 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
647 bio, 1);
648 BUG_ON(ret);
649
650 if (!(rw & (1 << BIO_RW))) {
651 /*
652 * called for a read, do the setup so that checksum validation
653 * can happen in the async kernel threads
654 */
655 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
656 mirror_num, 0);
657 }
658 /*
659 * kthread helpers are used to submit writes so that checksumming
660 * can happen in parallel across all CPUs
661 */
662 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
663 inode, rw, bio, mirror_num, 0,
664 __btree_submit_bio_start,
665 __btree_submit_bio_done);
666 }
667
668 static int btree_writepage(struct page *page, struct writeback_control *wbc)
669 {
670 struct extent_io_tree *tree;
671 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
672 struct extent_buffer *eb;
673 int was_dirty;
674
675 tree = &BTRFS_I(page->mapping->host)->io_tree;
676 if (!(current->flags & PF_MEMALLOC)) {
677 return extent_write_full_page(tree, page,
678 btree_get_extent, wbc);
679 }
680
681 redirty_page_for_writepage(wbc, page);
682 eb = btrfs_find_tree_block(root, page_offset(page),
683 PAGE_CACHE_SIZE);
684 WARN_ON(!eb);
685
686 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
687 if (!was_dirty) {
688 spin_lock(&root->fs_info->delalloc_lock);
689 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
690 spin_unlock(&root->fs_info->delalloc_lock);
691 }
692 free_extent_buffer(eb);
693
694 unlock_page(page);
695 return 0;
696 }
697
698 static int btree_writepages(struct address_space *mapping,
699 struct writeback_control *wbc)
700 {
701 struct extent_io_tree *tree;
702 tree = &BTRFS_I(mapping->host)->io_tree;
703 if (wbc->sync_mode == WB_SYNC_NONE) {
704 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
705 u64 num_dirty;
706 unsigned long thresh = 32 * 1024 * 1024;
707
708 if (wbc->for_kupdate)
709 return 0;
710
711 /* this is a bit racy, but that's ok */
712 num_dirty = root->fs_info->dirty_metadata_bytes;
713 if (num_dirty < thresh)
714 return 0;
715 }
716 return extent_writepages(tree, mapping, btree_get_extent, wbc);
717 }
718
719 static int btree_readpage(struct file *file, struct page *page)
720 {
721 struct extent_io_tree *tree;
722 tree = &BTRFS_I(page->mapping->host)->io_tree;
723 return extent_read_full_page(tree, page, btree_get_extent);
724 }
725
726 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
727 {
728 struct extent_io_tree *tree;
729 struct extent_map_tree *map;
730 int ret;
731
732 if (PageWriteback(page) || PageDirty(page))
733 return 0;
734
735 tree = &BTRFS_I(page->mapping->host)->io_tree;
736 map = &BTRFS_I(page->mapping->host)->extent_tree;
737
738 ret = try_release_extent_state(map, tree, page, gfp_flags);
739 if (!ret)
740 return 0;
741
742 ret = try_release_extent_buffer(tree, page);
743 if (ret == 1) {
744 ClearPagePrivate(page);
745 set_page_private(page, 0);
746 page_cache_release(page);
747 }
748
749 return ret;
750 }
751
752 static void btree_invalidatepage(struct page *page, unsigned long offset)
753 {
754 struct extent_io_tree *tree;
755 tree = &BTRFS_I(page->mapping->host)->io_tree;
756 extent_invalidatepage(tree, page, offset);
757 btree_releasepage(page, GFP_NOFS);
758 if (PagePrivate(page)) {
759 printk(KERN_WARNING "btrfs warning page private not zero "
760 "on page %llu\n", (unsigned long long)page_offset(page));
761 ClearPagePrivate(page);
762 set_page_private(page, 0);
763 page_cache_release(page);
764 }
765 }
766
767 #if 0
768 static int btree_writepage(struct page *page, struct writeback_control *wbc)
769 {
770 struct buffer_head *bh;
771 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
772 struct buffer_head *head;
773 if (!page_has_buffers(page)) {
774 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
775 (1 << BH_Dirty)|(1 << BH_Uptodate));
776 }
777 head = page_buffers(page);
778 bh = head;
779 do {
780 if (buffer_dirty(bh))
781 csum_tree_block(root, bh, 0);
782 bh = bh->b_this_page;
783 } while (bh != head);
784 return block_write_full_page(page, btree_get_block, wbc);
785 }
786 #endif
787
788 static struct address_space_operations btree_aops = {
789 .readpage = btree_readpage,
790 .writepage = btree_writepage,
791 .writepages = btree_writepages,
792 .releasepage = btree_releasepage,
793 .invalidatepage = btree_invalidatepage,
794 .sync_page = block_sync_page,
795 };
796
797 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
798 u64 parent_transid)
799 {
800 struct extent_buffer *buf = NULL;
801 struct inode *btree_inode = root->fs_info->btree_inode;
802 int ret = 0;
803
804 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
805 if (!buf)
806 return 0;
807 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
808 buf, 0, 0, btree_get_extent, 0);
809 free_extent_buffer(buf);
810 return ret;
811 }
812
813 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
814 u64 bytenr, u32 blocksize)
815 {
816 struct inode *btree_inode = root->fs_info->btree_inode;
817 struct extent_buffer *eb;
818 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
819 bytenr, blocksize, GFP_NOFS);
820 return eb;
821 }
822
823 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
824 u64 bytenr, u32 blocksize)
825 {
826 struct inode *btree_inode = root->fs_info->btree_inode;
827 struct extent_buffer *eb;
828
829 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
830 bytenr, blocksize, NULL, GFP_NOFS);
831 return eb;
832 }
833
834
835 int btrfs_write_tree_block(struct extent_buffer *buf)
836 {
837 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
838 buf->start + buf->len - 1, WB_SYNC_ALL);
839 }
840
841 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
842 {
843 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
844 buf->start, buf->start + buf->len - 1);
845 }
846
847 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
848 u32 blocksize, u64 parent_transid)
849 {
850 struct extent_buffer *buf = NULL;
851 struct inode *btree_inode = root->fs_info->btree_inode;
852 struct extent_io_tree *io_tree;
853 int ret;
854
855 io_tree = &BTRFS_I(btree_inode)->io_tree;
856
857 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
858 if (!buf)
859 return NULL;
860
861 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
862
863 if (ret == 0)
864 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
865 else
866 WARN_ON(1);
867 return buf;
868
869 }
870
871 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
872 struct extent_buffer *buf)
873 {
874 struct inode *btree_inode = root->fs_info->btree_inode;
875 if (btrfs_header_generation(buf) ==
876 root->fs_info->running_transaction->transid) {
877 btrfs_assert_tree_locked(buf);
878
879 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
880 spin_lock(&root->fs_info->delalloc_lock);
881 if (root->fs_info->dirty_metadata_bytes >= buf->len)
882 root->fs_info->dirty_metadata_bytes -= buf->len;
883 else
884 WARN_ON(1);
885 spin_unlock(&root->fs_info->delalloc_lock);
886 }
887
888 /* ugh, clear_extent_buffer_dirty needs to lock the page */
889 btrfs_set_lock_blocking(buf);
890 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
891 buf);
892 }
893 return 0;
894 }
895
896 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
897 u32 stripesize, struct btrfs_root *root,
898 struct btrfs_fs_info *fs_info,
899 u64 objectid)
900 {
901 root->node = NULL;
902 root->commit_root = NULL;
903 root->ref_tree = NULL;
904 root->sectorsize = sectorsize;
905 root->nodesize = nodesize;
906 root->leafsize = leafsize;
907 root->stripesize = stripesize;
908 root->ref_cows = 0;
909 root->track_dirty = 0;
910
911 root->fs_info = fs_info;
912 root->objectid = objectid;
913 root->last_trans = 0;
914 root->highest_inode = 0;
915 root->last_inode_alloc = 0;
916 root->name = NULL;
917 root->in_sysfs = 0;
918
919 INIT_LIST_HEAD(&root->dirty_list);
920 INIT_LIST_HEAD(&root->orphan_list);
921 INIT_LIST_HEAD(&root->dead_list);
922 spin_lock_init(&root->node_lock);
923 spin_lock_init(&root->list_lock);
924 mutex_init(&root->objectid_mutex);
925 mutex_init(&root->log_mutex);
926 init_waitqueue_head(&root->log_writer_wait);
927 init_waitqueue_head(&root->log_commit_wait[0]);
928 init_waitqueue_head(&root->log_commit_wait[1]);
929 atomic_set(&root->log_commit[0], 0);
930 atomic_set(&root->log_commit[1], 0);
931 atomic_set(&root->log_writers, 0);
932 root->log_batch = 0;
933 root->log_transid = 0;
934 extent_io_tree_init(&root->dirty_log_pages,
935 fs_info->btree_inode->i_mapping, GFP_NOFS);
936
937 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
938 root->ref_tree = &root->ref_tree_struct;
939
940 memset(&root->root_key, 0, sizeof(root->root_key));
941 memset(&root->root_item, 0, sizeof(root->root_item));
942 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
943 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
944 root->defrag_trans_start = fs_info->generation;
945 init_completion(&root->kobj_unregister);
946 root->defrag_running = 0;
947 root->defrag_level = 0;
948 root->root_key.objectid = objectid;
949 root->anon_super.s_root = NULL;
950 root->anon_super.s_dev = 0;
951 INIT_LIST_HEAD(&root->anon_super.s_list);
952 INIT_LIST_HEAD(&root->anon_super.s_instances);
953 init_rwsem(&root->anon_super.s_umount);
954
955 return 0;
956 }
957
958 static int find_and_setup_root(struct btrfs_root *tree_root,
959 struct btrfs_fs_info *fs_info,
960 u64 objectid,
961 struct btrfs_root *root)
962 {
963 int ret;
964 u32 blocksize;
965 u64 generation;
966
967 __setup_root(tree_root->nodesize, tree_root->leafsize,
968 tree_root->sectorsize, tree_root->stripesize,
969 root, fs_info, objectid);
970 ret = btrfs_find_last_root(tree_root, objectid,
971 &root->root_item, &root->root_key);
972 BUG_ON(ret);
973
974 generation = btrfs_root_generation(&root->root_item);
975 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
976 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
977 blocksize, generation);
978 BUG_ON(!root->node);
979 return 0;
980 }
981
982 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
983 struct btrfs_fs_info *fs_info)
984 {
985 struct extent_buffer *eb;
986 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
987 u64 start = 0;
988 u64 end = 0;
989 int ret;
990
991 if (!log_root_tree)
992 return 0;
993
994 while (1) {
995 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
996 0, &start, &end, EXTENT_DIRTY);
997 if (ret)
998 break;
999
1000 clear_extent_dirty(&log_root_tree->dirty_log_pages,
1001 start, end, GFP_NOFS);
1002 }
1003 eb = fs_info->log_root_tree->node;
1004
1005 WARN_ON(btrfs_header_level(eb) != 0);
1006 WARN_ON(btrfs_header_nritems(eb) != 0);
1007
1008 ret = btrfs_free_reserved_extent(fs_info->tree_root,
1009 eb->start, eb->len);
1010 BUG_ON(ret);
1011
1012 free_extent_buffer(eb);
1013 kfree(fs_info->log_root_tree);
1014 fs_info->log_root_tree = NULL;
1015 return 0;
1016 }
1017
1018 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1019 struct btrfs_fs_info *fs_info)
1020 {
1021 struct btrfs_root *root;
1022 struct btrfs_root *tree_root = fs_info->tree_root;
1023 struct extent_buffer *leaf;
1024
1025 root = kzalloc(sizeof(*root), GFP_NOFS);
1026 if (!root)
1027 return ERR_PTR(-ENOMEM);
1028
1029 __setup_root(tree_root->nodesize, tree_root->leafsize,
1030 tree_root->sectorsize, tree_root->stripesize,
1031 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1032
1033 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1034 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1035 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1036 /*
1037 * log trees do not get reference counted because they go away
1038 * before a real commit is actually done. They do store pointers
1039 * to file data extents, and those reference counts still get
1040 * updated (along with back refs to the log tree).
1041 */
1042 root->ref_cows = 0;
1043
1044 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1045 0, BTRFS_TREE_LOG_OBJECTID,
1046 trans->transid, 0, 0, 0);
1047 if (IS_ERR(leaf)) {
1048 kfree(root);
1049 return ERR_CAST(leaf);
1050 }
1051
1052 root->node = leaf;
1053 btrfs_set_header_nritems(root->node, 0);
1054 btrfs_set_header_level(root->node, 0);
1055 btrfs_set_header_bytenr(root->node, root->node->start);
1056 btrfs_set_header_generation(root->node, trans->transid);
1057 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
1058
1059 write_extent_buffer(root->node, root->fs_info->fsid,
1060 (unsigned long)btrfs_header_fsid(root->node),
1061 BTRFS_FSID_SIZE);
1062 btrfs_mark_buffer_dirty(root->node);
1063 btrfs_tree_unlock(root->node);
1064 return root;
1065 }
1066
1067 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1068 struct btrfs_fs_info *fs_info)
1069 {
1070 struct btrfs_root *log_root;
1071
1072 log_root = alloc_log_tree(trans, fs_info);
1073 if (IS_ERR(log_root))
1074 return PTR_ERR(log_root);
1075 WARN_ON(fs_info->log_root_tree);
1076 fs_info->log_root_tree = log_root;
1077 return 0;
1078 }
1079
1080 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1081 struct btrfs_root *root)
1082 {
1083 struct btrfs_root *log_root;
1084 struct btrfs_inode_item *inode_item;
1085
1086 log_root = alloc_log_tree(trans, root->fs_info);
1087 if (IS_ERR(log_root))
1088 return PTR_ERR(log_root);
1089
1090 log_root->last_trans = trans->transid;
1091 log_root->root_key.offset = root->root_key.objectid;
1092
1093 inode_item = &log_root->root_item.inode;
1094 inode_item->generation = cpu_to_le64(1);
1095 inode_item->size = cpu_to_le64(3);
1096 inode_item->nlink = cpu_to_le32(1);
1097 inode_item->nbytes = cpu_to_le64(root->leafsize);
1098 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1099
1100 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1101 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1102
1103 WARN_ON(root->log_root);
1104 root->log_root = log_root;
1105 root->log_transid = 0;
1106 return 0;
1107 }
1108
1109 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1110 struct btrfs_key *location)
1111 {
1112 struct btrfs_root *root;
1113 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1114 struct btrfs_path *path;
1115 struct extent_buffer *l;
1116 u64 highest_inode;
1117 u64 generation;
1118 u32 blocksize;
1119 int ret = 0;
1120
1121 root = kzalloc(sizeof(*root), GFP_NOFS);
1122 if (!root)
1123 return ERR_PTR(-ENOMEM);
1124 if (location->offset == (u64)-1) {
1125 ret = find_and_setup_root(tree_root, fs_info,
1126 location->objectid, root);
1127 if (ret) {
1128 kfree(root);
1129 return ERR_PTR(ret);
1130 }
1131 goto insert;
1132 }
1133
1134 __setup_root(tree_root->nodesize, tree_root->leafsize,
1135 tree_root->sectorsize, tree_root->stripesize,
1136 root, fs_info, location->objectid);
1137
1138 path = btrfs_alloc_path();
1139 BUG_ON(!path);
1140 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1141 if (ret != 0) {
1142 if (ret > 0)
1143 ret = -ENOENT;
1144 goto out;
1145 }
1146 l = path->nodes[0];
1147 read_extent_buffer(l, &root->root_item,
1148 btrfs_item_ptr_offset(l, path->slots[0]),
1149 sizeof(root->root_item));
1150 memcpy(&root->root_key, location, sizeof(*location));
1151 ret = 0;
1152 out:
1153 btrfs_release_path(root, path);
1154 btrfs_free_path(path);
1155 if (ret) {
1156 kfree(root);
1157 return ERR_PTR(ret);
1158 }
1159 generation = btrfs_root_generation(&root->root_item);
1160 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1161 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1162 blocksize, generation);
1163 BUG_ON(!root->node);
1164 insert:
1165 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1166 root->ref_cows = 1;
1167 ret = btrfs_find_highest_inode(root, &highest_inode);
1168 if (ret == 0) {
1169 root->highest_inode = highest_inode;
1170 root->last_inode_alloc = highest_inode;
1171 }
1172 }
1173 return root;
1174 }
1175
1176 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1177 u64 root_objectid)
1178 {
1179 struct btrfs_root *root;
1180
1181 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1182 return fs_info->tree_root;
1183 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1184 return fs_info->extent_root;
1185
1186 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1187 (unsigned long)root_objectid);
1188 return root;
1189 }
1190
1191 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1192 struct btrfs_key *location)
1193 {
1194 struct btrfs_root *root;
1195 int ret;
1196
1197 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1198 return fs_info->tree_root;
1199 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1200 return fs_info->extent_root;
1201 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1202 return fs_info->chunk_root;
1203 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1204 return fs_info->dev_root;
1205 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1206 return fs_info->csum_root;
1207
1208 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1209 (unsigned long)location->objectid);
1210 if (root)
1211 return root;
1212
1213 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1214 if (IS_ERR(root))
1215 return root;
1216
1217 set_anon_super(&root->anon_super, NULL);
1218
1219 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1220 (unsigned long)root->root_key.objectid,
1221 root);
1222 if (ret) {
1223 free_extent_buffer(root->node);
1224 kfree(root);
1225 return ERR_PTR(ret);
1226 }
1227 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1228 ret = btrfs_find_dead_roots(fs_info->tree_root,
1229 root->root_key.objectid, root);
1230 BUG_ON(ret);
1231 btrfs_orphan_cleanup(root);
1232 }
1233 return root;
1234 }
1235
1236 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1237 struct btrfs_key *location,
1238 const char *name, int namelen)
1239 {
1240 struct btrfs_root *root;
1241 int ret;
1242
1243 root = btrfs_read_fs_root_no_name(fs_info, location);
1244 if (!root)
1245 return NULL;
1246
1247 if (root->in_sysfs)
1248 return root;
1249
1250 ret = btrfs_set_root_name(root, name, namelen);
1251 if (ret) {
1252 free_extent_buffer(root->node);
1253 kfree(root);
1254 return ERR_PTR(ret);
1255 }
1256 #if 0
1257 ret = btrfs_sysfs_add_root(root);
1258 if (ret) {
1259 free_extent_buffer(root->node);
1260 kfree(root->name);
1261 kfree(root);
1262 return ERR_PTR(ret);
1263 }
1264 #endif
1265 root->in_sysfs = 1;
1266 return root;
1267 }
1268
1269 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1270 {
1271 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1272 int ret = 0;
1273 struct btrfs_device *device;
1274 struct backing_dev_info *bdi;
1275 #if 0
1276 if ((bdi_bits & (1 << BDI_write_congested)) &&
1277 btrfs_congested_async(info, 0))
1278 return 1;
1279 #endif
1280 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1281 if (!device->bdev)
1282 continue;
1283 bdi = blk_get_backing_dev_info(device->bdev);
1284 if (bdi && bdi_congested(bdi, bdi_bits)) {
1285 ret = 1;
1286 break;
1287 }
1288 }
1289 return ret;
1290 }
1291
1292 /*
1293 * this unplugs every device on the box, and it is only used when page
1294 * is null
1295 */
1296 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1297 {
1298 struct btrfs_device *device;
1299 struct btrfs_fs_info *info;
1300
1301 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1302 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1303 if (!device->bdev)
1304 continue;
1305
1306 bdi = blk_get_backing_dev_info(device->bdev);
1307 if (bdi->unplug_io_fn)
1308 bdi->unplug_io_fn(bdi, page);
1309 }
1310 }
1311
1312 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1313 {
1314 struct inode *inode;
1315 struct extent_map_tree *em_tree;
1316 struct extent_map *em;
1317 struct address_space *mapping;
1318 u64 offset;
1319
1320 /* the generic O_DIRECT read code does this */
1321 if (1 || !page) {
1322 __unplug_io_fn(bdi, page);
1323 return;
1324 }
1325
1326 /*
1327 * page->mapping may change at any time. Get a consistent copy
1328 * and use that for everything below
1329 */
1330 smp_mb();
1331 mapping = page->mapping;
1332 if (!mapping)
1333 return;
1334
1335 inode = mapping->host;
1336
1337 /*
1338 * don't do the expensive searching for a small number of
1339 * devices
1340 */
1341 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1342 __unplug_io_fn(bdi, page);
1343 return;
1344 }
1345
1346 offset = page_offset(page);
1347
1348 em_tree = &BTRFS_I(inode)->extent_tree;
1349 spin_lock(&em_tree->lock);
1350 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1351 spin_unlock(&em_tree->lock);
1352 if (!em) {
1353 __unplug_io_fn(bdi, page);
1354 return;
1355 }
1356
1357 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1358 free_extent_map(em);
1359 __unplug_io_fn(bdi, page);
1360 return;
1361 }
1362 offset = offset - em->start;
1363 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1364 em->block_start + offset, page);
1365 free_extent_map(em);
1366 }
1367
1368 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1369 {
1370 bdi_init(bdi);
1371 bdi->ra_pages = default_backing_dev_info.ra_pages;
1372 bdi->state = 0;
1373 bdi->capabilities = default_backing_dev_info.capabilities;
1374 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1375 bdi->unplug_io_data = info;
1376 bdi->congested_fn = btrfs_congested_fn;
1377 bdi->congested_data = info;
1378 return 0;
1379 }
1380
1381 static int bio_ready_for_csum(struct bio *bio)
1382 {
1383 u64 length = 0;
1384 u64 buf_len = 0;
1385 u64 start = 0;
1386 struct page *page;
1387 struct extent_io_tree *io_tree = NULL;
1388 struct btrfs_fs_info *info = NULL;
1389 struct bio_vec *bvec;
1390 int i;
1391 int ret;
1392
1393 bio_for_each_segment(bvec, bio, i) {
1394 page = bvec->bv_page;
1395 if (page->private == EXTENT_PAGE_PRIVATE) {
1396 length += bvec->bv_len;
1397 continue;
1398 }
1399 if (!page->private) {
1400 length += bvec->bv_len;
1401 continue;
1402 }
1403 length = bvec->bv_len;
1404 buf_len = page->private >> 2;
1405 start = page_offset(page) + bvec->bv_offset;
1406 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1407 info = BTRFS_I(page->mapping->host)->root->fs_info;
1408 }
1409 /* are we fully contained in this bio? */
1410 if (buf_len <= length)
1411 return 1;
1412
1413 ret = extent_range_uptodate(io_tree, start + length,
1414 start + buf_len - 1);
1415 if (ret == 1)
1416 return ret;
1417 return ret;
1418 }
1419
1420 /*
1421 * called by the kthread helper functions to finally call the bio end_io
1422 * functions. This is where read checksum verification actually happens
1423 */
1424 static void end_workqueue_fn(struct btrfs_work *work)
1425 {
1426 struct bio *bio;
1427 struct end_io_wq *end_io_wq;
1428 struct btrfs_fs_info *fs_info;
1429 int error;
1430
1431 end_io_wq = container_of(work, struct end_io_wq, work);
1432 bio = end_io_wq->bio;
1433 fs_info = end_io_wq->info;
1434
1435 /* metadata bio reads are special because the whole tree block must
1436 * be checksummed at once. This makes sure the entire block is in
1437 * ram and up to date before trying to verify things. For
1438 * blocksize <= pagesize, it is basically a noop
1439 */
1440 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1441 !bio_ready_for_csum(bio)) {
1442 btrfs_queue_worker(&fs_info->endio_meta_workers,
1443 &end_io_wq->work);
1444 return;
1445 }
1446 error = end_io_wq->error;
1447 bio->bi_private = end_io_wq->private;
1448 bio->bi_end_io = end_io_wq->end_io;
1449 kfree(end_io_wq);
1450 bio_endio(bio, error);
1451 }
1452
1453 static int cleaner_kthread(void *arg)
1454 {
1455 struct btrfs_root *root = arg;
1456
1457 do {
1458 smp_mb();
1459 if (root->fs_info->closing)
1460 break;
1461
1462 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1463 mutex_lock(&root->fs_info->cleaner_mutex);
1464 btrfs_clean_old_snapshots(root);
1465 mutex_unlock(&root->fs_info->cleaner_mutex);
1466
1467 if (freezing(current)) {
1468 refrigerator();
1469 } else {
1470 smp_mb();
1471 if (root->fs_info->closing)
1472 break;
1473 set_current_state(TASK_INTERRUPTIBLE);
1474 schedule();
1475 __set_current_state(TASK_RUNNING);
1476 }
1477 } while (!kthread_should_stop());
1478 return 0;
1479 }
1480
1481 static int transaction_kthread(void *arg)
1482 {
1483 struct btrfs_root *root = arg;
1484 struct btrfs_trans_handle *trans;
1485 struct btrfs_transaction *cur;
1486 unsigned long now;
1487 unsigned long delay;
1488 int ret;
1489
1490 do {
1491 smp_mb();
1492 if (root->fs_info->closing)
1493 break;
1494
1495 delay = HZ * 30;
1496 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1497 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1498
1499 mutex_lock(&root->fs_info->trans_mutex);
1500 cur = root->fs_info->running_transaction;
1501 if (!cur) {
1502 mutex_unlock(&root->fs_info->trans_mutex);
1503 goto sleep;
1504 }
1505
1506 now = get_seconds();
1507 if (now < cur->start_time || now - cur->start_time < 30) {
1508 mutex_unlock(&root->fs_info->trans_mutex);
1509 delay = HZ * 5;
1510 goto sleep;
1511 }
1512 mutex_unlock(&root->fs_info->trans_mutex);
1513 trans = btrfs_start_transaction(root, 1);
1514 ret = btrfs_commit_transaction(trans, root);
1515
1516 sleep:
1517 wake_up_process(root->fs_info->cleaner_kthread);
1518 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1519
1520 if (freezing(current)) {
1521 refrigerator();
1522 } else {
1523 if (root->fs_info->closing)
1524 break;
1525 set_current_state(TASK_INTERRUPTIBLE);
1526 schedule_timeout(delay);
1527 __set_current_state(TASK_RUNNING);
1528 }
1529 } while (!kthread_should_stop());
1530 return 0;
1531 }
1532
1533 struct btrfs_root *open_ctree(struct super_block *sb,
1534 struct btrfs_fs_devices *fs_devices,
1535 char *options)
1536 {
1537 u32 sectorsize;
1538 u32 nodesize;
1539 u32 leafsize;
1540 u32 blocksize;
1541 u32 stripesize;
1542 u64 generation;
1543 u64 features;
1544 struct btrfs_key location;
1545 struct buffer_head *bh;
1546 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1547 GFP_NOFS);
1548 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1549 GFP_NOFS);
1550 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1551 GFP_NOFS);
1552 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1553 GFP_NOFS);
1554 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1555 GFP_NOFS);
1556 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1557 GFP_NOFS);
1558 struct btrfs_root *log_tree_root;
1559
1560 int ret;
1561 int err = -EINVAL;
1562
1563 struct btrfs_super_block *disk_super;
1564
1565 if (!extent_root || !tree_root || !fs_info ||
1566 !chunk_root || !dev_root || !csum_root) {
1567 err = -ENOMEM;
1568 goto fail;
1569 }
1570 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1571 INIT_LIST_HEAD(&fs_info->trans_list);
1572 INIT_LIST_HEAD(&fs_info->dead_roots);
1573 INIT_LIST_HEAD(&fs_info->hashers);
1574 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1575 INIT_LIST_HEAD(&fs_info->ordered_operations);
1576 spin_lock_init(&fs_info->delalloc_lock);
1577 spin_lock_init(&fs_info->new_trans_lock);
1578 spin_lock_init(&fs_info->ref_cache_lock);
1579
1580 init_completion(&fs_info->kobj_unregister);
1581 fs_info->tree_root = tree_root;
1582 fs_info->extent_root = extent_root;
1583 fs_info->csum_root = csum_root;
1584 fs_info->chunk_root = chunk_root;
1585 fs_info->dev_root = dev_root;
1586 fs_info->fs_devices = fs_devices;
1587 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1588 INIT_LIST_HEAD(&fs_info->space_info);
1589 btrfs_mapping_init(&fs_info->mapping_tree);
1590 atomic_set(&fs_info->nr_async_submits, 0);
1591 atomic_set(&fs_info->async_delalloc_pages, 0);
1592 atomic_set(&fs_info->async_submit_draining, 0);
1593 atomic_set(&fs_info->nr_async_bios, 0);
1594 atomic_set(&fs_info->throttles, 0);
1595 atomic_set(&fs_info->throttle_gen, 0);
1596 fs_info->sb = sb;
1597 fs_info->max_extent = (u64)-1;
1598 fs_info->max_inline = 8192 * 1024;
1599 setup_bdi(fs_info, &fs_info->bdi);
1600 fs_info->btree_inode = new_inode(sb);
1601 fs_info->btree_inode->i_ino = 1;
1602 fs_info->btree_inode->i_nlink = 1;
1603
1604 fs_info->thread_pool_size = min_t(unsigned long,
1605 num_online_cpus() + 2, 8);
1606
1607 INIT_LIST_HEAD(&fs_info->ordered_extents);
1608 spin_lock_init(&fs_info->ordered_extent_lock);
1609
1610 sb->s_blocksize = 4096;
1611 sb->s_blocksize_bits = blksize_bits(4096);
1612
1613 /*
1614 * we set the i_size on the btree inode to the max possible int.
1615 * the real end of the address space is determined by all of
1616 * the devices in the system
1617 */
1618 fs_info->btree_inode->i_size = OFFSET_MAX;
1619 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1620 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1621
1622 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1623 fs_info->btree_inode->i_mapping,
1624 GFP_NOFS);
1625 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1626 GFP_NOFS);
1627
1628 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1629
1630 spin_lock_init(&fs_info->block_group_cache_lock);
1631 fs_info->block_group_cache_tree.rb_node = NULL;
1632
1633 extent_io_tree_init(&fs_info->pinned_extents,
1634 fs_info->btree_inode->i_mapping, GFP_NOFS);
1635 fs_info->do_barriers = 1;
1636
1637 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1638 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1639 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1640
1641 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1642 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1643 sizeof(struct btrfs_key));
1644 insert_inode_hash(fs_info->btree_inode);
1645
1646 mutex_init(&fs_info->trans_mutex);
1647 mutex_init(&fs_info->ordered_operations_mutex);
1648 mutex_init(&fs_info->tree_log_mutex);
1649 mutex_init(&fs_info->drop_mutex);
1650 mutex_init(&fs_info->pinned_mutex);
1651 mutex_init(&fs_info->chunk_mutex);
1652 mutex_init(&fs_info->transaction_kthread_mutex);
1653 mutex_init(&fs_info->cleaner_mutex);
1654 mutex_init(&fs_info->volume_mutex);
1655 mutex_init(&fs_info->tree_reloc_mutex);
1656 init_waitqueue_head(&fs_info->transaction_throttle);
1657 init_waitqueue_head(&fs_info->transaction_wait);
1658 init_waitqueue_head(&fs_info->async_submit_wait);
1659
1660 __setup_root(4096, 4096, 4096, 4096, tree_root,
1661 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1662
1663
1664 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1665 if (!bh)
1666 goto fail_iput;
1667
1668 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1669 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1670 sizeof(fs_info->super_for_commit));
1671 brelse(bh);
1672
1673 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1674
1675 disk_super = &fs_info->super_copy;
1676 if (!btrfs_super_root(disk_super))
1677 goto fail_iput;
1678
1679 ret = btrfs_parse_options(tree_root, options);
1680 if (ret) {
1681 err = ret;
1682 goto fail_iput;
1683 }
1684
1685 features = btrfs_super_incompat_flags(disk_super) &
1686 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1687 if (features) {
1688 printk(KERN_ERR "BTRFS: couldn't mount because of "
1689 "unsupported optional features (%Lx).\n",
1690 features);
1691 err = -EINVAL;
1692 goto fail_iput;
1693 }
1694
1695 features = btrfs_super_compat_ro_flags(disk_super) &
1696 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1697 if (!(sb->s_flags & MS_RDONLY) && features) {
1698 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1699 "unsupported option features (%Lx).\n",
1700 features);
1701 err = -EINVAL;
1702 goto fail_iput;
1703 }
1704
1705 /*
1706 * we need to start all the end_io workers up front because the
1707 * queue work function gets called at interrupt time, and so it
1708 * cannot dynamically grow.
1709 */
1710 btrfs_init_workers(&fs_info->workers, "worker",
1711 fs_info->thread_pool_size);
1712
1713 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1714 fs_info->thread_pool_size);
1715
1716 btrfs_init_workers(&fs_info->submit_workers, "submit",
1717 min_t(u64, fs_devices->num_devices,
1718 fs_info->thread_pool_size));
1719
1720 /* a higher idle thresh on the submit workers makes it much more
1721 * likely that bios will be send down in a sane order to the
1722 * devices
1723 */
1724 fs_info->submit_workers.idle_thresh = 64;
1725
1726 fs_info->workers.idle_thresh = 16;
1727 fs_info->workers.ordered = 1;
1728
1729 fs_info->delalloc_workers.idle_thresh = 2;
1730 fs_info->delalloc_workers.ordered = 1;
1731
1732 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1733 btrfs_init_workers(&fs_info->endio_workers, "endio",
1734 fs_info->thread_pool_size);
1735 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1736 fs_info->thread_pool_size);
1737 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1738 "endio-meta-write", fs_info->thread_pool_size);
1739 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1740 fs_info->thread_pool_size);
1741
1742 /*
1743 * endios are largely parallel and should have a very
1744 * low idle thresh
1745 */
1746 fs_info->endio_workers.idle_thresh = 4;
1747 fs_info->endio_meta_workers.idle_thresh = 4;
1748
1749 fs_info->endio_write_workers.idle_thresh = 64;
1750 fs_info->endio_meta_write_workers.idle_thresh = 64;
1751
1752 btrfs_start_workers(&fs_info->workers, 1);
1753 btrfs_start_workers(&fs_info->submit_workers, 1);
1754 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1755 btrfs_start_workers(&fs_info->fixup_workers, 1);
1756 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1757 btrfs_start_workers(&fs_info->endio_meta_workers,
1758 fs_info->thread_pool_size);
1759 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1760 fs_info->thread_pool_size);
1761 btrfs_start_workers(&fs_info->endio_write_workers,
1762 fs_info->thread_pool_size);
1763
1764 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1765 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1766 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1767
1768 nodesize = btrfs_super_nodesize(disk_super);
1769 leafsize = btrfs_super_leafsize(disk_super);
1770 sectorsize = btrfs_super_sectorsize(disk_super);
1771 stripesize = btrfs_super_stripesize(disk_super);
1772 tree_root->nodesize = nodesize;
1773 tree_root->leafsize = leafsize;
1774 tree_root->sectorsize = sectorsize;
1775 tree_root->stripesize = stripesize;
1776
1777 sb->s_blocksize = sectorsize;
1778 sb->s_blocksize_bits = blksize_bits(sectorsize);
1779
1780 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1781 sizeof(disk_super->magic))) {
1782 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1783 goto fail_sb_buffer;
1784 }
1785
1786 mutex_lock(&fs_info->chunk_mutex);
1787 ret = btrfs_read_sys_array(tree_root);
1788 mutex_unlock(&fs_info->chunk_mutex);
1789 if (ret) {
1790 printk(KERN_WARNING "btrfs: failed to read the system "
1791 "array on %s\n", sb->s_id);
1792 goto fail_sys_array;
1793 }
1794
1795 blocksize = btrfs_level_size(tree_root,
1796 btrfs_super_chunk_root_level(disk_super));
1797 generation = btrfs_super_chunk_root_generation(disk_super);
1798
1799 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1800 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1801
1802 chunk_root->node = read_tree_block(chunk_root,
1803 btrfs_super_chunk_root(disk_super),
1804 blocksize, generation);
1805 BUG_ON(!chunk_root->node);
1806
1807 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1808 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1809 BTRFS_UUID_SIZE);
1810
1811 mutex_lock(&fs_info->chunk_mutex);
1812 ret = btrfs_read_chunk_tree(chunk_root);
1813 mutex_unlock(&fs_info->chunk_mutex);
1814 if (ret) {
1815 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1816 sb->s_id);
1817 goto fail_chunk_root;
1818 }
1819
1820 btrfs_close_extra_devices(fs_devices);
1821
1822 blocksize = btrfs_level_size(tree_root,
1823 btrfs_super_root_level(disk_super));
1824 generation = btrfs_super_generation(disk_super);
1825
1826 tree_root->node = read_tree_block(tree_root,
1827 btrfs_super_root(disk_super),
1828 blocksize, generation);
1829 if (!tree_root->node)
1830 goto fail_chunk_root;
1831
1832
1833 ret = find_and_setup_root(tree_root, fs_info,
1834 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1835 if (ret)
1836 goto fail_tree_root;
1837 extent_root->track_dirty = 1;
1838
1839 ret = find_and_setup_root(tree_root, fs_info,
1840 BTRFS_DEV_TREE_OBJECTID, dev_root);
1841 dev_root->track_dirty = 1;
1842 if (ret)
1843 goto fail_extent_root;
1844
1845 ret = find_and_setup_root(tree_root, fs_info,
1846 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1847 if (ret)
1848 goto fail_extent_root;
1849
1850 csum_root->track_dirty = 1;
1851
1852 btrfs_read_block_groups(extent_root);
1853
1854 fs_info->generation = generation;
1855 fs_info->last_trans_committed = generation;
1856 fs_info->data_alloc_profile = (u64)-1;
1857 fs_info->metadata_alloc_profile = (u64)-1;
1858 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1859 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1860 "btrfs-cleaner");
1861 if (IS_ERR(fs_info->cleaner_kthread))
1862 goto fail_csum_root;
1863
1864 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1865 tree_root,
1866 "btrfs-transaction");
1867 if (IS_ERR(fs_info->transaction_kthread))
1868 goto fail_cleaner;
1869
1870 if (btrfs_super_log_root(disk_super) != 0) {
1871 u64 bytenr = btrfs_super_log_root(disk_super);
1872
1873 if (fs_devices->rw_devices == 0) {
1874 printk(KERN_WARNING "Btrfs log replay required "
1875 "on RO media\n");
1876 err = -EIO;
1877 goto fail_trans_kthread;
1878 }
1879 blocksize =
1880 btrfs_level_size(tree_root,
1881 btrfs_super_log_root_level(disk_super));
1882
1883 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1884 GFP_NOFS);
1885
1886 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1887 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1888
1889 log_tree_root->node = read_tree_block(tree_root, bytenr,
1890 blocksize,
1891 generation + 1);
1892 ret = btrfs_recover_log_trees(log_tree_root);
1893 BUG_ON(ret);
1894
1895 if (sb->s_flags & MS_RDONLY) {
1896 ret = btrfs_commit_super(tree_root);
1897 BUG_ON(ret);
1898 }
1899 }
1900
1901 if (!(sb->s_flags & MS_RDONLY)) {
1902 ret = btrfs_cleanup_reloc_trees(tree_root);
1903 BUG_ON(ret);
1904 }
1905
1906 location.objectid = BTRFS_FS_TREE_OBJECTID;
1907 location.type = BTRFS_ROOT_ITEM_KEY;
1908 location.offset = (u64)-1;
1909
1910 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1911 if (!fs_info->fs_root)
1912 goto fail_trans_kthread;
1913 return tree_root;
1914
1915 fail_trans_kthread:
1916 kthread_stop(fs_info->transaction_kthread);
1917 fail_cleaner:
1918 kthread_stop(fs_info->cleaner_kthread);
1919
1920 /*
1921 * make sure we're done with the btree inode before we stop our
1922 * kthreads
1923 */
1924 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1925 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1926
1927 fail_csum_root:
1928 free_extent_buffer(csum_root->node);
1929 fail_extent_root:
1930 free_extent_buffer(extent_root->node);
1931 fail_tree_root:
1932 free_extent_buffer(tree_root->node);
1933 fail_chunk_root:
1934 free_extent_buffer(chunk_root->node);
1935 fail_sys_array:
1936 free_extent_buffer(dev_root->node);
1937 fail_sb_buffer:
1938 btrfs_stop_workers(&fs_info->fixup_workers);
1939 btrfs_stop_workers(&fs_info->delalloc_workers);
1940 btrfs_stop_workers(&fs_info->workers);
1941 btrfs_stop_workers(&fs_info->endio_workers);
1942 btrfs_stop_workers(&fs_info->endio_meta_workers);
1943 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1944 btrfs_stop_workers(&fs_info->endio_write_workers);
1945 btrfs_stop_workers(&fs_info->submit_workers);
1946 fail_iput:
1947 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1948 iput(fs_info->btree_inode);
1949
1950 btrfs_close_devices(fs_info->fs_devices);
1951 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1952 bdi_destroy(&fs_info->bdi);
1953
1954 fail:
1955 kfree(extent_root);
1956 kfree(tree_root);
1957 kfree(fs_info);
1958 kfree(chunk_root);
1959 kfree(dev_root);
1960 kfree(csum_root);
1961 return ERR_PTR(err);
1962 }
1963
1964 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1965 {
1966 char b[BDEVNAME_SIZE];
1967
1968 if (uptodate) {
1969 set_buffer_uptodate(bh);
1970 } else {
1971 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1972 printk(KERN_WARNING "lost page write due to "
1973 "I/O error on %s\n",
1974 bdevname(bh->b_bdev, b));
1975 }
1976 /* note, we dont' set_buffer_write_io_error because we have
1977 * our own ways of dealing with the IO errors
1978 */
1979 clear_buffer_uptodate(bh);
1980 }
1981 unlock_buffer(bh);
1982 put_bh(bh);
1983 }
1984
1985 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1986 {
1987 struct buffer_head *bh;
1988 struct buffer_head *latest = NULL;
1989 struct btrfs_super_block *super;
1990 int i;
1991 u64 transid = 0;
1992 u64 bytenr;
1993
1994 /* we would like to check all the supers, but that would make
1995 * a btrfs mount succeed after a mkfs from a different FS.
1996 * So, we need to add a special mount option to scan for
1997 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1998 */
1999 for (i = 0; i < 1; i++) {
2000 bytenr = btrfs_sb_offset(i);
2001 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2002 break;
2003 bh = __bread(bdev, bytenr / 4096, 4096);
2004 if (!bh)
2005 continue;
2006
2007 super = (struct btrfs_super_block *)bh->b_data;
2008 if (btrfs_super_bytenr(super) != bytenr ||
2009 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2010 sizeof(super->magic))) {
2011 brelse(bh);
2012 continue;
2013 }
2014
2015 if (!latest || btrfs_super_generation(super) > transid) {
2016 brelse(latest);
2017 latest = bh;
2018 transid = btrfs_super_generation(super);
2019 } else {
2020 brelse(bh);
2021 }
2022 }
2023 return latest;
2024 }
2025
2026 static int write_dev_supers(struct btrfs_device *device,
2027 struct btrfs_super_block *sb,
2028 int do_barriers, int wait, int max_mirrors)
2029 {
2030 struct buffer_head *bh;
2031 int i;
2032 int ret;
2033 int errors = 0;
2034 u32 crc;
2035 u64 bytenr;
2036 int last_barrier = 0;
2037
2038 if (max_mirrors == 0)
2039 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2040
2041 /* make sure only the last submit_bh does a barrier */
2042 if (do_barriers) {
2043 for (i = 0; i < max_mirrors; i++) {
2044 bytenr = btrfs_sb_offset(i);
2045 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2046 device->total_bytes)
2047 break;
2048 last_barrier = i;
2049 }
2050 }
2051
2052 for (i = 0; i < max_mirrors; i++) {
2053 bytenr = btrfs_sb_offset(i);
2054 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2055 break;
2056
2057 if (wait) {
2058 bh = __find_get_block(device->bdev, bytenr / 4096,
2059 BTRFS_SUPER_INFO_SIZE);
2060 BUG_ON(!bh);
2061 brelse(bh);
2062 wait_on_buffer(bh);
2063 if (buffer_uptodate(bh)) {
2064 brelse(bh);
2065 continue;
2066 }
2067 } else {
2068 btrfs_set_super_bytenr(sb, bytenr);
2069
2070 crc = ~(u32)0;
2071 crc = btrfs_csum_data(NULL, (char *)sb +
2072 BTRFS_CSUM_SIZE, crc,
2073 BTRFS_SUPER_INFO_SIZE -
2074 BTRFS_CSUM_SIZE);
2075 btrfs_csum_final(crc, sb->csum);
2076
2077 bh = __getblk(device->bdev, bytenr / 4096,
2078 BTRFS_SUPER_INFO_SIZE);
2079 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2080
2081 set_buffer_uptodate(bh);
2082 get_bh(bh);
2083 lock_buffer(bh);
2084 bh->b_end_io = btrfs_end_buffer_write_sync;
2085 }
2086
2087 if (i == last_barrier && do_barriers && device->barriers) {
2088 ret = submit_bh(WRITE_BARRIER, bh);
2089 if (ret == -EOPNOTSUPP) {
2090 printk("btrfs: disabling barriers on dev %s\n",
2091 device->name);
2092 set_buffer_uptodate(bh);
2093 device->barriers = 0;
2094 get_bh(bh);
2095 lock_buffer(bh);
2096 ret = submit_bh(WRITE, bh);
2097 }
2098 } else {
2099 ret = submit_bh(WRITE, bh);
2100 }
2101
2102 if (!ret && wait) {
2103 wait_on_buffer(bh);
2104 if (!buffer_uptodate(bh))
2105 errors++;
2106 } else if (ret) {
2107 errors++;
2108 }
2109 if (wait)
2110 brelse(bh);
2111 }
2112 return errors < i ? 0 : -1;
2113 }
2114
2115 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2116 {
2117 struct list_head *head = &root->fs_info->fs_devices->devices;
2118 struct btrfs_device *dev;
2119 struct btrfs_super_block *sb;
2120 struct btrfs_dev_item *dev_item;
2121 int ret;
2122 int do_barriers;
2123 int max_errors;
2124 int total_errors = 0;
2125 u64 flags;
2126
2127 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2128 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2129
2130 sb = &root->fs_info->super_for_commit;
2131 dev_item = &sb->dev_item;
2132 list_for_each_entry(dev, head, dev_list) {
2133 if (!dev->bdev) {
2134 total_errors++;
2135 continue;
2136 }
2137 if (!dev->in_fs_metadata || !dev->writeable)
2138 continue;
2139
2140 btrfs_set_stack_device_generation(dev_item, 0);
2141 btrfs_set_stack_device_type(dev_item, dev->type);
2142 btrfs_set_stack_device_id(dev_item, dev->devid);
2143 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2144 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2145 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2146 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2147 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2148 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2149 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2150
2151 flags = btrfs_super_flags(sb);
2152 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2153
2154 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2155 if (ret)
2156 total_errors++;
2157 }
2158 if (total_errors > max_errors) {
2159 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2160 total_errors);
2161 BUG();
2162 }
2163
2164 total_errors = 0;
2165 list_for_each_entry(dev, head, dev_list) {
2166 if (!dev->bdev)
2167 continue;
2168 if (!dev->in_fs_metadata || !dev->writeable)
2169 continue;
2170
2171 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2172 if (ret)
2173 total_errors++;
2174 }
2175 if (total_errors > max_errors) {
2176 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2177 total_errors);
2178 BUG();
2179 }
2180 return 0;
2181 }
2182
2183 int write_ctree_super(struct btrfs_trans_handle *trans,
2184 struct btrfs_root *root, int max_mirrors)
2185 {
2186 int ret;
2187
2188 ret = write_all_supers(root, max_mirrors);
2189 return ret;
2190 }
2191
2192 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2193 {
2194 radix_tree_delete(&fs_info->fs_roots_radix,
2195 (unsigned long)root->root_key.objectid);
2196 if (root->anon_super.s_dev) {
2197 down_write(&root->anon_super.s_umount);
2198 kill_anon_super(&root->anon_super);
2199 }
2200 if (root->node)
2201 free_extent_buffer(root->node);
2202 if (root->commit_root)
2203 free_extent_buffer(root->commit_root);
2204 kfree(root->name);
2205 kfree(root);
2206 return 0;
2207 }
2208
2209 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2210 {
2211 int ret;
2212 struct btrfs_root *gang[8];
2213 int i;
2214
2215 while (1) {
2216 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2217 (void **)gang, 0,
2218 ARRAY_SIZE(gang));
2219 if (!ret)
2220 break;
2221 for (i = 0; i < ret; i++)
2222 btrfs_free_fs_root(fs_info, gang[i]);
2223 }
2224 return 0;
2225 }
2226
2227 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2228 {
2229 u64 root_objectid = 0;
2230 struct btrfs_root *gang[8];
2231 int i;
2232 int ret;
2233
2234 while (1) {
2235 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2236 (void **)gang, root_objectid,
2237 ARRAY_SIZE(gang));
2238 if (!ret)
2239 break;
2240 for (i = 0; i < ret; i++) {
2241 root_objectid = gang[i]->root_key.objectid;
2242 ret = btrfs_find_dead_roots(fs_info->tree_root,
2243 root_objectid, gang[i]);
2244 BUG_ON(ret);
2245 btrfs_orphan_cleanup(gang[i]);
2246 }
2247 root_objectid++;
2248 }
2249 return 0;
2250 }
2251
2252 int btrfs_commit_super(struct btrfs_root *root)
2253 {
2254 struct btrfs_trans_handle *trans;
2255 int ret;
2256
2257 mutex_lock(&root->fs_info->cleaner_mutex);
2258 btrfs_clean_old_snapshots(root);
2259 mutex_unlock(&root->fs_info->cleaner_mutex);
2260 trans = btrfs_start_transaction(root, 1);
2261 ret = btrfs_commit_transaction(trans, root);
2262 BUG_ON(ret);
2263 /* run commit again to drop the original snapshot */
2264 trans = btrfs_start_transaction(root, 1);
2265 btrfs_commit_transaction(trans, root);
2266 ret = btrfs_write_and_wait_transaction(NULL, root);
2267 BUG_ON(ret);
2268
2269 ret = write_ctree_super(NULL, root, 0);
2270 return ret;
2271 }
2272
2273 int close_ctree(struct btrfs_root *root)
2274 {
2275 struct btrfs_fs_info *fs_info = root->fs_info;
2276 int ret;
2277
2278 fs_info->closing = 1;
2279 smp_mb();
2280
2281 kthread_stop(root->fs_info->transaction_kthread);
2282 kthread_stop(root->fs_info->cleaner_kthread);
2283
2284 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2285 ret = btrfs_commit_super(root);
2286 if (ret)
2287 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2288 }
2289
2290 if (fs_info->delalloc_bytes) {
2291 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2292 fs_info->delalloc_bytes);
2293 }
2294 if (fs_info->total_ref_cache_size) {
2295 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2296 (unsigned long long)fs_info->total_ref_cache_size);
2297 }
2298
2299 if (fs_info->extent_root->node)
2300 free_extent_buffer(fs_info->extent_root->node);
2301
2302 if (fs_info->tree_root->node)
2303 free_extent_buffer(fs_info->tree_root->node);
2304
2305 if (root->fs_info->chunk_root->node)
2306 free_extent_buffer(root->fs_info->chunk_root->node);
2307
2308 if (root->fs_info->dev_root->node)
2309 free_extent_buffer(root->fs_info->dev_root->node);
2310
2311 if (root->fs_info->csum_root->node)
2312 free_extent_buffer(root->fs_info->csum_root->node);
2313
2314 btrfs_free_block_groups(root->fs_info);
2315
2316 del_fs_roots(fs_info);
2317
2318 iput(fs_info->btree_inode);
2319
2320 btrfs_stop_workers(&fs_info->fixup_workers);
2321 btrfs_stop_workers(&fs_info->delalloc_workers);
2322 btrfs_stop_workers(&fs_info->workers);
2323 btrfs_stop_workers(&fs_info->endio_workers);
2324 btrfs_stop_workers(&fs_info->endio_meta_workers);
2325 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2326 btrfs_stop_workers(&fs_info->endio_write_workers);
2327 btrfs_stop_workers(&fs_info->submit_workers);
2328
2329 #if 0
2330 while (!list_empty(&fs_info->hashers)) {
2331 struct btrfs_hasher *hasher;
2332 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
2333 hashers);
2334 list_del(&hasher->hashers);
2335 crypto_free_hash(&fs_info->hash_tfm);
2336 kfree(hasher);
2337 }
2338 #endif
2339 btrfs_close_devices(fs_info->fs_devices);
2340 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2341
2342 bdi_destroy(&fs_info->bdi);
2343
2344 kfree(fs_info->extent_root);
2345 kfree(fs_info->tree_root);
2346 kfree(fs_info->chunk_root);
2347 kfree(fs_info->dev_root);
2348 kfree(fs_info->csum_root);
2349 return 0;
2350 }
2351
2352 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2353 {
2354 int ret;
2355 struct inode *btree_inode = buf->first_page->mapping->host;
2356
2357 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2358 if (!ret)
2359 return ret;
2360
2361 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2362 parent_transid);
2363 return !ret;
2364 }
2365
2366 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2367 {
2368 struct inode *btree_inode = buf->first_page->mapping->host;
2369 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2370 buf);
2371 }
2372
2373 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2374 {
2375 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2376 u64 transid = btrfs_header_generation(buf);
2377 struct inode *btree_inode = root->fs_info->btree_inode;
2378 int was_dirty;
2379
2380 btrfs_assert_tree_locked(buf);
2381 if (transid != root->fs_info->generation) {
2382 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2383 "found %llu running %llu\n",
2384 (unsigned long long)buf->start,
2385 (unsigned long long)transid,
2386 (unsigned long long)root->fs_info->generation);
2387 WARN_ON(1);
2388 }
2389 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2390 buf);
2391 if (!was_dirty) {
2392 spin_lock(&root->fs_info->delalloc_lock);
2393 root->fs_info->dirty_metadata_bytes += buf->len;
2394 spin_unlock(&root->fs_info->delalloc_lock);
2395 }
2396 }
2397
2398 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2399 {
2400 /*
2401 * looks as though older kernels can get into trouble with
2402 * this code, they end up stuck in balance_dirty_pages forever
2403 */
2404 struct extent_io_tree *tree;
2405 u64 num_dirty;
2406 u64 start = 0;
2407 unsigned long thresh = 32 * 1024 * 1024;
2408 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2409
2410 if (current->flags & PF_MEMALLOC)
2411 return;
2412
2413 num_dirty = count_range_bits(tree, &start, (u64)-1,
2414 thresh, EXTENT_DIRTY);
2415 if (num_dirty > thresh) {
2416 balance_dirty_pages_ratelimited_nr(
2417 root->fs_info->btree_inode->i_mapping, 1);
2418 }
2419 return;
2420 }
2421
2422 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2423 {
2424 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2425 int ret;
2426 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2427 if (ret == 0)
2428 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2429 return ret;
2430 }
2431
2432 int btree_lock_page_hook(struct page *page)
2433 {
2434 struct inode *inode = page->mapping->host;
2435 struct btrfs_root *root = BTRFS_I(inode)->root;
2436 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2437 struct extent_buffer *eb;
2438 unsigned long len;
2439 u64 bytenr = page_offset(page);
2440
2441 if (page->private == EXTENT_PAGE_PRIVATE)
2442 goto out;
2443
2444 len = page->private >> 2;
2445 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2446 if (!eb)
2447 goto out;
2448
2449 btrfs_tree_lock(eb);
2450 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2451
2452 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2453 spin_lock(&root->fs_info->delalloc_lock);
2454 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2455 root->fs_info->dirty_metadata_bytes -= eb->len;
2456 else
2457 WARN_ON(1);
2458 spin_unlock(&root->fs_info->delalloc_lock);
2459 }
2460
2461 btrfs_tree_unlock(eb);
2462 free_extent_buffer(eb);
2463 out:
2464 lock_page(page);
2465 return 0;
2466 }
2467
2468 static struct extent_io_ops btree_extent_io_ops = {
2469 .write_cache_pages_lock_hook = btree_lock_page_hook,
2470 .readpage_end_io_hook = btree_readpage_end_io_hook,
2471 .submit_bio_hook = btree_submit_bio_hook,
2472 /* note we're sharing with inode.c for the merge bio hook */
2473 .merge_bio_hook = btrfs_merge_bio_hook,
2474 };
CJK support for tty framebuffer vt