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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / disk-io.c
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 <linux/crc32c.h>
30 #include <linux/slab.h>
31 #include <linux/migrate.h>
32 #include "compat.h"
33 #include "ctree.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "btrfs_inode.h"
37 #include "volumes.h"
38 #include "print-tree.h"
39 #include "async-thread.h"
40 #include "locking.h"
41 #include "tree-log.h"
42 #include "free-space-cache.h"
43
44 static struct extent_io_ops btree_extent_io_ops;
45 static void end_workqueue_fn(struct btrfs_work *work);
46 static void free_fs_root(struct btrfs_root *root);
47 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
48 int read_only);
49 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
50 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
51 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
52 struct btrfs_root *root);
53 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
54 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
55 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
56 struct extent_io_tree *dirty_pages,
57 int mark);
58 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
59 struct extent_io_tree *pinned_extents);
60 static int btrfs_cleanup_transaction(struct btrfs_root *root);
61
62 /*
63 * end_io_wq structs are used to do processing in task context when an IO is
64 * complete. This is used during reads to verify checksums, and it is used
65 * by writes to insert metadata for new file extents after IO is complete.
66 */
67 struct end_io_wq {
68 struct bio *bio;
69 bio_end_io_t *end_io;
70 void *private;
71 struct btrfs_fs_info *info;
72 int error;
73 int metadata;
74 struct list_head list;
75 struct btrfs_work work;
76 };
77
78 /*
79 * async submit bios are used to offload expensive checksumming
80 * onto the worker threads. They checksum file and metadata bios
81 * just before they are sent down the IO stack.
82 */
83 struct async_submit_bio {
84 struct inode *inode;
85 struct bio *bio;
86 struct list_head list;
87 extent_submit_bio_hook_t *submit_bio_start;
88 extent_submit_bio_hook_t *submit_bio_done;
89 int rw;
90 int mirror_num;
91 unsigned long bio_flags;
92 /*
93 * bio_offset is optional, can be used if the pages in the bio
94 * can't tell us where in the file the bio should go
95 */
96 u64 bio_offset;
97 struct btrfs_work work;
98 };
99
100 /* These are used to set the lockdep class on the extent buffer locks.
101 * The class is set by the readpage_end_io_hook after the buffer has
102 * passed csum validation but before the pages are unlocked.
103 *
104 * The lockdep class is also set by btrfs_init_new_buffer on freshly
105 * allocated blocks.
106 *
107 * The class is based on the level in the tree block, which allows lockdep
108 * to know that lower nodes nest inside the locks of higher nodes.
109 *
110 * We also add a check to make sure the highest level of the tree is
111 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
112 * code needs update as well.
113 */
114 #ifdef CONFIG_DEBUG_LOCK_ALLOC
115 # if BTRFS_MAX_LEVEL != 8
116 # error
117 # endif
118 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
119 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
120 /* leaf */
121 "btrfs-extent-00",
122 "btrfs-extent-01",
123 "btrfs-extent-02",
124 "btrfs-extent-03",
125 "btrfs-extent-04",
126 "btrfs-extent-05",
127 "btrfs-extent-06",
128 "btrfs-extent-07",
129 /* highest possible level */
130 "btrfs-extent-08",
131 };
132 #endif
133
134 /*
135 * extents on the btree inode are pretty simple, there's one extent
136 * that covers the entire device
137 */
138 static struct extent_map *btree_get_extent(struct inode *inode,
139 struct page *page, size_t page_offset, u64 start, u64 len,
140 int create)
141 {
142 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
143 struct extent_map *em;
144 int ret;
145
146 read_lock(&em_tree->lock);
147 em = lookup_extent_mapping(em_tree, start, len);
148 if (em) {
149 em->bdev =
150 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
151 read_unlock(&em_tree->lock);
152 goto out;
153 }
154 read_unlock(&em_tree->lock);
155
156 em = alloc_extent_map(GFP_NOFS);
157 if (!em) {
158 em = ERR_PTR(-ENOMEM);
159 goto out;
160 }
161 em->start = 0;
162 em->len = (u64)-1;
163 em->block_len = (u64)-1;
164 em->block_start = 0;
165 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
166
167 write_lock(&em_tree->lock);
168 ret = add_extent_mapping(em_tree, em);
169 if (ret == -EEXIST) {
170 u64 failed_start = em->start;
171 u64 failed_len = em->len;
172
173 free_extent_map(em);
174 em = lookup_extent_mapping(em_tree, start, len);
175 if (em) {
176 ret = 0;
177 } else {
178 em = lookup_extent_mapping(em_tree, failed_start,
179 failed_len);
180 ret = -EIO;
181 }
182 } else if (ret) {
183 free_extent_map(em);
184 em = NULL;
185 }
186 write_unlock(&em_tree->lock);
187
188 if (ret)
189 em = ERR_PTR(ret);
190 out:
191 return em;
192 }
193
194 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
195 {
196 return crc32c(seed, data, len);
197 }
198
199 void btrfs_csum_final(u32 crc, char *result)
200 {
201 *(__le32 *)result = ~cpu_to_le32(crc);
202 }
203
204 /*
205 * compute the csum for a btree block, and either verify it or write it
206 * into the csum field of the block.
207 */
208 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
209 int verify)
210 {
211 u16 csum_size =
212 btrfs_super_csum_size(&root->fs_info->super_copy);
213 char *result = NULL;
214 unsigned long len;
215 unsigned long cur_len;
216 unsigned long offset = BTRFS_CSUM_SIZE;
217 char *map_token = NULL;
218 char *kaddr;
219 unsigned long map_start;
220 unsigned long map_len;
221 int err;
222 u32 crc = ~(u32)0;
223 unsigned long inline_result;
224
225 len = buf->len - offset;
226 while (len > 0) {
227 err = map_private_extent_buffer(buf, offset, 32,
228 &map_token, &kaddr,
229 &map_start, &map_len, KM_USER0);
230 if (err)
231 return 1;
232 cur_len = min(len, map_len - (offset - map_start));
233 crc = btrfs_csum_data(root, kaddr + offset - map_start,
234 crc, cur_len);
235 len -= cur_len;
236 offset += cur_len;
237 unmap_extent_buffer(buf, map_token, KM_USER0);
238 }
239 if (csum_size > sizeof(inline_result)) {
240 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
241 if (!result)
242 return 1;
243 } else {
244 result = (char *)&inline_result;
245 }
246
247 btrfs_csum_final(crc, result);
248
249 if (verify) {
250 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
251 u32 val;
252 u32 found = 0;
253 memcpy(&found, result, csum_size);
254
255 read_extent_buffer(buf, &val, 0, csum_size);
256 if (printk_ratelimit()) {
257 printk(KERN_INFO "btrfs: %s checksum verify "
258 "failed on %llu wanted %X found %X "
259 "level %d\n",
260 root->fs_info->sb->s_id,
261 (unsigned long long)buf->start, val, found,
262 btrfs_header_level(buf));
263 }
264 if (result != (char *)&inline_result)
265 kfree(result);
266 return 1;
267 }
268 } else {
269 write_extent_buffer(buf, result, 0, csum_size);
270 }
271 if (result != (char *)&inline_result)
272 kfree(result);
273 return 0;
274 }
275
276 /*
277 * we can't consider a given block up to date unless the transid of the
278 * block matches the transid in the parent node's pointer. This is how we
279 * detect blocks that either didn't get written at all or got written
280 * in the wrong place.
281 */
282 static int verify_parent_transid(struct extent_io_tree *io_tree,
283 struct extent_buffer *eb, u64 parent_transid)
284 {
285 struct extent_state *cached_state = NULL;
286 int ret;
287
288 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
289 return 0;
290
291 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
292 0, &cached_state, GFP_NOFS);
293 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
294 btrfs_header_generation(eb) == parent_transid) {
295 ret = 0;
296 goto out;
297 }
298 if (printk_ratelimit()) {
299 printk("parent transid verify failed on %llu wanted %llu "
300 "found %llu\n",
301 (unsigned long long)eb->start,
302 (unsigned long long)parent_transid,
303 (unsigned long long)btrfs_header_generation(eb));
304 }
305 ret = 1;
306 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
307 out:
308 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
309 &cached_state, GFP_NOFS);
310 return ret;
311 }
312
313 /*
314 * helper to read a given tree block, doing retries as required when
315 * the checksums don't match and we have alternate mirrors to try.
316 */
317 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
318 struct extent_buffer *eb,
319 u64 start, u64 parent_transid)
320 {
321 struct extent_io_tree *io_tree;
322 int ret;
323 int num_copies = 0;
324 int mirror_num = 0;
325
326 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
327 while (1) {
328 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
329 btree_get_extent, mirror_num);
330 if (!ret &&
331 !verify_parent_transid(io_tree, eb, parent_transid))
332 return ret;
333
334 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
335 eb->start, eb->len);
336 if (num_copies == 1)
337 return ret;
338
339 mirror_num++;
340 if (mirror_num > num_copies)
341 return ret;
342 }
343 return -EIO;
344 }
345
346 /*
347 * checksum a dirty tree block before IO. This has extra checks to make sure
348 * we only fill in the checksum field in the first page of a multi-page block
349 */
350
351 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
352 {
353 struct extent_io_tree *tree;
354 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
355 u64 found_start;
356 unsigned long len;
357 struct extent_buffer *eb;
358 int ret;
359
360 tree = &BTRFS_I(page->mapping->host)->io_tree;
361
362 if (page->private == EXTENT_PAGE_PRIVATE) {
363 WARN_ON(1);
364 goto out;
365 }
366 if (!page->private) {
367 WARN_ON(1);
368 goto out;
369 }
370 len = page->private >> 2;
371 WARN_ON(len == 0);
372
373 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
374 if (eb == NULL) {
375 WARN_ON(1);
376 goto out;
377 }
378 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
379 btrfs_header_generation(eb));
380 BUG_ON(ret);
381 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
382
383 found_start = btrfs_header_bytenr(eb);
384 if (found_start != start) {
385 WARN_ON(1);
386 goto err;
387 }
388 if (eb->first_page != page) {
389 WARN_ON(1);
390 goto err;
391 }
392 if (!PageUptodate(page)) {
393 WARN_ON(1);
394 goto err;
395 }
396 csum_tree_block(root, eb, 0);
397 err:
398 free_extent_buffer(eb);
399 out:
400 return 0;
401 }
402
403 static int check_tree_block_fsid(struct btrfs_root *root,
404 struct extent_buffer *eb)
405 {
406 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
407 u8 fsid[BTRFS_UUID_SIZE];
408 int ret = 1;
409
410 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
411 BTRFS_FSID_SIZE);
412 while (fs_devices) {
413 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
414 ret = 0;
415 break;
416 }
417 fs_devices = fs_devices->seed;
418 }
419 return ret;
420 }
421
422 #ifdef CONFIG_DEBUG_LOCK_ALLOC
423 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
424 {
425 lockdep_set_class_and_name(&eb->lock,
426 &btrfs_eb_class[level],
427 btrfs_eb_name[level]);
428 }
429 #endif
430
431 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
432 struct extent_state *state)
433 {
434 struct extent_io_tree *tree;
435 u64 found_start;
436 int found_level;
437 unsigned long len;
438 struct extent_buffer *eb;
439 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
440 int ret = 0;
441
442 tree = &BTRFS_I(page->mapping->host)->io_tree;
443 if (page->private == EXTENT_PAGE_PRIVATE)
444 goto out;
445 if (!page->private)
446 goto out;
447
448 len = page->private >> 2;
449 WARN_ON(len == 0);
450
451 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
452 if (eb == NULL) {
453 ret = -EIO;
454 goto out;
455 }
456
457 found_start = btrfs_header_bytenr(eb);
458 if (found_start != start) {
459 if (printk_ratelimit()) {
460 printk(KERN_INFO "btrfs bad tree block start "
461 "%llu %llu\n",
462 (unsigned long long)found_start,
463 (unsigned long long)eb->start);
464 }
465 ret = -EIO;
466 goto err;
467 }
468 if (eb->first_page != page) {
469 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
470 eb->first_page->index, page->index);
471 WARN_ON(1);
472 ret = -EIO;
473 goto err;
474 }
475 if (check_tree_block_fsid(root, eb)) {
476 if (printk_ratelimit()) {
477 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
478 (unsigned long long)eb->start);
479 }
480 ret = -EIO;
481 goto err;
482 }
483 found_level = btrfs_header_level(eb);
484
485 btrfs_set_buffer_lockdep_class(eb, found_level);
486
487 ret = csum_tree_block(root, eb, 1);
488 if (ret)
489 ret = -EIO;
490
491 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
492 end = eb->start + end - 1;
493 err:
494 free_extent_buffer(eb);
495 out:
496 return ret;
497 }
498
499 static void end_workqueue_bio(struct bio *bio, int err)
500 {
501 struct end_io_wq *end_io_wq = bio->bi_private;
502 struct btrfs_fs_info *fs_info;
503
504 fs_info = end_io_wq->info;
505 end_io_wq->error = err;
506 end_io_wq->work.func = end_workqueue_fn;
507 end_io_wq->work.flags = 0;
508
509 if (bio->bi_rw & REQ_WRITE) {
510 if (end_io_wq->metadata == 1)
511 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
512 &end_io_wq->work);
513 else if (end_io_wq->metadata == 2)
514 btrfs_queue_worker(&fs_info->endio_freespace_worker,
515 &end_io_wq->work);
516 else
517 btrfs_queue_worker(&fs_info->endio_write_workers,
518 &end_io_wq->work);
519 } else {
520 if (end_io_wq->metadata)
521 btrfs_queue_worker(&fs_info->endio_meta_workers,
522 &end_io_wq->work);
523 else
524 btrfs_queue_worker(&fs_info->endio_workers,
525 &end_io_wq->work);
526 }
527 }
528
529 /*
530 * For the metadata arg you want
531 *
532 * 0 - if data
533 * 1 - if normal metadta
534 * 2 - if writing to the free space cache area
535 */
536 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
537 int metadata)
538 {
539 struct end_io_wq *end_io_wq;
540 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
541 if (!end_io_wq)
542 return -ENOMEM;
543
544 end_io_wq->private = bio->bi_private;
545 end_io_wq->end_io = bio->bi_end_io;
546 end_io_wq->info = info;
547 end_io_wq->error = 0;
548 end_io_wq->bio = bio;
549 end_io_wq->metadata = metadata;
550
551 bio->bi_private = end_io_wq;
552 bio->bi_end_io = end_workqueue_bio;
553 return 0;
554 }
555
556 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
557 {
558 unsigned long limit = min_t(unsigned long,
559 info->workers.max_workers,
560 info->fs_devices->open_devices);
561 return 256 * limit;
562 }
563
564 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
565 {
566 return atomic_read(&info->nr_async_bios) >
567 btrfs_async_submit_limit(info);
568 }
569
570 static void run_one_async_start(struct btrfs_work *work)
571 {
572 struct async_submit_bio *async;
573
574 async = container_of(work, struct async_submit_bio, work);
575 async->submit_bio_start(async->inode, async->rw, async->bio,
576 async->mirror_num, async->bio_flags,
577 async->bio_offset);
578 }
579
580 static void run_one_async_done(struct btrfs_work *work)
581 {
582 struct btrfs_fs_info *fs_info;
583 struct async_submit_bio *async;
584 int limit;
585
586 async = container_of(work, struct async_submit_bio, work);
587 fs_info = BTRFS_I(async->inode)->root->fs_info;
588
589 limit = btrfs_async_submit_limit(fs_info);
590 limit = limit * 2 / 3;
591
592 atomic_dec(&fs_info->nr_async_submits);
593
594 if (atomic_read(&fs_info->nr_async_submits) < limit &&
595 waitqueue_active(&fs_info->async_submit_wait))
596 wake_up(&fs_info->async_submit_wait);
597
598 async->submit_bio_done(async->inode, async->rw, async->bio,
599 async->mirror_num, async->bio_flags,
600 async->bio_offset);
601 }
602
603 static void run_one_async_free(struct btrfs_work *work)
604 {
605 struct async_submit_bio *async;
606
607 async = container_of(work, struct async_submit_bio, work);
608 kfree(async);
609 }
610
611 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
612 int rw, struct bio *bio, int mirror_num,
613 unsigned long bio_flags,
614 u64 bio_offset,
615 extent_submit_bio_hook_t *submit_bio_start,
616 extent_submit_bio_hook_t *submit_bio_done)
617 {
618 struct async_submit_bio *async;
619
620 async = kmalloc(sizeof(*async), GFP_NOFS);
621 if (!async)
622 return -ENOMEM;
623
624 async->inode = inode;
625 async->rw = rw;
626 async->bio = bio;
627 async->mirror_num = mirror_num;
628 async->submit_bio_start = submit_bio_start;
629 async->submit_bio_done = submit_bio_done;
630
631 async->work.func = run_one_async_start;
632 async->work.ordered_func = run_one_async_done;
633 async->work.ordered_free = run_one_async_free;
634
635 async->work.flags = 0;
636 async->bio_flags = bio_flags;
637 async->bio_offset = bio_offset;
638
639 atomic_inc(&fs_info->nr_async_submits);
640
641 if (rw & REQ_SYNC)
642 btrfs_set_work_high_prio(&async->work);
643
644 btrfs_queue_worker(&fs_info->workers, &async->work);
645
646 while (atomic_read(&fs_info->async_submit_draining) &&
647 atomic_read(&fs_info->nr_async_submits)) {
648 wait_event(fs_info->async_submit_wait,
649 (atomic_read(&fs_info->nr_async_submits) == 0));
650 }
651
652 return 0;
653 }
654
655 static int btree_csum_one_bio(struct bio *bio)
656 {
657 struct bio_vec *bvec = bio->bi_io_vec;
658 int bio_index = 0;
659 struct btrfs_root *root;
660
661 WARN_ON(bio->bi_vcnt <= 0);
662 while (bio_index < bio->bi_vcnt) {
663 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
664 csum_dirty_buffer(root, bvec->bv_page);
665 bio_index++;
666 bvec++;
667 }
668 return 0;
669 }
670
671 static int __btree_submit_bio_start(struct inode *inode, int rw,
672 struct bio *bio, int mirror_num,
673 unsigned long bio_flags,
674 u64 bio_offset)
675 {
676 /*
677 * when we're called for a write, we're already in the async
678 * submission context. Just jump into btrfs_map_bio
679 */
680 btree_csum_one_bio(bio);
681 return 0;
682 }
683
684 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
685 int mirror_num, unsigned long bio_flags,
686 u64 bio_offset)
687 {
688 /*
689 * when we're called for a write, we're already in the async
690 * submission context. Just jump into btrfs_map_bio
691 */
692 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
693 }
694
695 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
696 int mirror_num, unsigned long bio_flags,
697 u64 bio_offset)
698 {
699 int ret;
700
701 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
702 bio, 1);
703 BUG_ON(ret);
704
705 if (!(rw & REQ_WRITE)) {
706 /*
707 * called for a read, do the setup so that checksum validation
708 * can happen in the async kernel threads
709 */
710 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
711 mirror_num, 0);
712 }
713
714 /*
715 * kthread helpers are used to submit writes so that checksumming
716 * can happen in parallel across all CPUs
717 */
718 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
719 inode, rw, bio, mirror_num, 0,
720 bio_offset,
721 __btree_submit_bio_start,
722 __btree_submit_bio_done);
723 }
724
725 #ifdef CONFIG_MIGRATION
726 static int btree_migratepage(struct address_space *mapping,
727 struct page *newpage, struct page *page)
728 {
729 /*
730 * we can't safely write a btree page from here,
731 * we haven't done the locking hook
732 */
733 if (PageDirty(page))
734 return -EAGAIN;
735 /*
736 * Buffers may be managed in a filesystem specific way.
737 * We must have no buffers or drop them.
738 */
739 if (page_has_private(page) &&
740 !try_to_release_page(page, GFP_KERNEL))
741 return -EAGAIN;
742 return migrate_page(mapping, newpage, page);
743 }
744 #endif
745
746 static int btree_writepage(struct page *page, struct writeback_control *wbc)
747 {
748 struct extent_io_tree *tree;
749 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
750 struct extent_buffer *eb;
751 int was_dirty;
752
753 tree = &BTRFS_I(page->mapping->host)->io_tree;
754 if (!(current->flags & PF_MEMALLOC)) {
755 return extent_write_full_page(tree, page,
756 btree_get_extent, wbc);
757 }
758
759 redirty_page_for_writepage(wbc, page);
760 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
761 WARN_ON(!eb);
762
763 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
764 if (!was_dirty) {
765 spin_lock(&root->fs_info->delalloc_lock);
766 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
767 spin_unlock(&root->fs_info->delalloc_lock);
768 }
769 free_extent_buffer(eb);
770
771 unlock_page(page);
772 return 0;
773 }
774
775 static int btree_writepages(struct address_space *mapping,
776 struct writeback_control *wbc)
777 {
778 struct extent_io_tree *tree;
779 tree = &BTRFS_I(mapping->host)->io_tree;
780 if (wbc->sync_mode == WB_SYNC_NONE) {
781 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
782 u64 num_dirty;
783 unsigned long thresh = 32 * 1024 * 1024;
784
785 if (wbc->for_kupdate)
786 return 0;
787
788 /* this is a bit racy, but that's ok */
789 num_dirty = root->fs_info->dirty_metadata_bytes;
790 if (num_dirty < thresh)
791 return 0;
792 }
793 return extent_writepages(tree, mapping, btree_get_extent, wbc);
794 }
795
796 static int btree_readpage(struct file *file, struct page *page)
797 {
798 struct extent_io_tree *tree;
799 tree = &BTRFS_I(page->mapping->host)->io_tree;
800 return extent_read_full_page(tree, page, btree_get_extent);
801 }
802
803 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
804 {
805 struct extent_io_tree *tree;
806 struct extent_map_tree *map;
807 int ret;
808
809 if (PageWriteback(page) || PageDirty(page))
810 return 0;
811
812 tree = &BTRFS_I(page->mapping->host)->io_tree;
813 map = &BTRFS_I(page->mapping->host)->extent_tree;
814
815 ret = try_release_extent_state(map, tree, page, gfp_flags);
816 if (!ret)
817 return 0;
818
819 ret = try_release_extent_buffer(tree, page);
820 if (ret == 1) {
821 ClearPagePrivate(page);
822 set_page_private(page, 0);
823 page_cache_release(page);
824 }
825
826 return ret;
827 }
828
829 static void btree_invalidatepage(struct page *page, unsigned long offset)
830 {
831 struct extent_io_tree *tree;
832 tree = &BTRFS_I(page->mapping->host)->io_tree;
833 extent_invalidatepage(tree, page, offset);
834 btree_releasepage(page, GFP_NOFS);
835 if (PagePrivate(page)) {
836 printk(KERN_WARNING "btrfs warning page private not zero "
837 "on page %llu\n", (unsigned long long)page_offset(page));
838 ClearPagePrivate(page);
839 set_page_private(page, 0);
840 page_cache_release(page);
841 }
842 }
843
844 static const struct address_space_operations btree_aops = {
845 .readpage = btree_readpage,
846 .writepage = btree_writepage,
847 .writepages = btree_writepages,
848 .releasepage = btree_releasepage,
849 .invalidatepage = btree_invalidatepage,
850 .sync_page = block_sync_page,
851 #ifdef CONFIG_MIGRATION
852 .migratepage = btree_migratepage,
853 #endif
854 };
855
856 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
857 u64 parent_transid)
858 {
859 struct extent_buffer *buf = NULL;
860 struct inode *btree_inode = root->fs_info->btree_inode;
861 int ret = 0;
862
863 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
864 if (!buf)
865 return 0;
866 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
867 buf, 0, 0, btree_get_extent, 0);
868 free_extent_buffer(buf);
869 return ret;
870 }
871
872 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
873 u64 bytenr, u32 blocksize)
874 {
875 struct inode *btree_inode = root->fs_info->btree_inode;
876 struct extent_buffer *eb;
877 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
878 bytenr, blocksize, GFP_NOFS);
879 return eb;
880 }
881
882 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
883 u64 bytenr, u32 blocksize)
884 {
885 struct inode *btree_inode = root->fs_info->btree_inode;
886 struct extent_buffer *eb;
887
888 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
889 bytenr, blocksize, NULL, GFP_NOFS);
890 return eb;
891 }
892
893
894 int btrfs_write_tree_block(struct extent_buffer *buf)
895 {
896 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
897 buf->start + buf->len - 1);
898 }
899
900 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
901 {
902 return filemap_fdatawait_range(buf->first_page->mapping,
903 buf->start, buf->start + buf->len - 1);
904 }
905
906 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
907 u32 blocksize, u64 parent_transid)
908 {
909 struct extent_buffer *buf = NULL;
910 int ret;
911
912 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
913 if (!buf)
914 return NULL;
915
916 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
917
918 if (ret == 0)
919 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
920 return buf;
921
922 }
923
924 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
925 struct extent_buffer *buf)
926 {
927 struct inode *btree_inode = root->fs_info->btree_inode;
928 if (btrfs_header_generation(buf) ==
929 root->fs_info->running_transaction->transid) {
930 btrfs_assert_tree_locked(buf);
931
932 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
933 spin_lock(&root->fs_info->delalloc_lock);
934 if (root->fs_info->dirty_metadata_bytes >= buf->len)
935 root->fs_info->dirty_metadata_bytes -= buf->len;
936 else
937 WARN_ON(1);
938 spin_unlock(&root->fs_info->delalloc_lock);
939 }
940
941 /* ugh, clear_extent_buffer_dirty needs to lock the page */
942 btrfs_set_lock_blocking(buf);
943 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
944 buf);
945 }
946 return 0;
947 }
948
949 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
950 u32 stripesize, struct btrfs_root *root,
951 struct btrfs_fs_info *fs_info,
952 u64 objectid)
953 {
954 root->node = NULL;
955 root->commit_root = NULL;
956 root->sectorsize = sectorsize;
957 root->nodesize = nodesize;
958 root->leafsize = leafsize;
959 root->stripesize = stripesize;
960 root->ref_cows = 0;
961 root->track_dirty = 0;
962 root->in_radix = 0;
963 root->orphan_item_inserted = 0;
964 root->orphan_cleanup_state = 0;
965
966 root->fs_info = fs_info;
967 root->objectid = objectid;
968 root->last_trans = 0;
969 root->highest_objectid = 0;
970 root->name = NULL;
971 root->in_sysfs = 0;
972 root->inode_tree = RB_ROOT;
973 root->block_rsv = NULL;
974 root->orphan_block_rsv = NULL;
975
976 INIT_LIST_HEAD(&root->dirty_list);
977 INIT_LIST_HEAD(&root->orphan_list);
978 INIT_LIST_HEAD(&root->root_list);
979 spin_lock_init(&root->node_lock);
980 spin_lock_init(&root->orphan_lock);
981 spin_lock_init(&root->inode_lock);
982 spin_lock_init(&root->accounting_lock);
983 mutex_init(&root->objectid_mutex);
984 mutex_init(&root->log_mutex);
985 init_waitqueue_head(&root->log_writer_wait);
986 init_waitqueue_head(&root->log_commit_wait[0]);
987 init_waitqueue_head(&root->log_commit_wait[1]);
988 atomic_set(&root->log_commit[0], 0);
989 atomic_set(&root->log_commit[1], 0);
990 atomic_set(&root->log_writers, 0);
991 root->log_batch = 0;
992 root->log_transid = 0;
993 root->last_log_commit = 0;
994 extent_io_tree_init(&root->dirty_log_pages,
995 fs_info->btree_inode->i_mapping, GFP_NOFS);
996
997 memset(&root->root_key, 0, sizeof(root->root_key));
998 memset(&root->root_item, 0, sizeof(root->root_item));
999 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1000 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1001 root->defrag_trans_start = fs_info->generation;
1002 init_completion(&root->kobj_unregister);
1003 root->defrag_running = 0;
1004 root->root_key.objectid = objectid;
1005 root->anon_super.s_root = NULL;
1006 root->anon_super.s_dev = 0;
1007 INIT_LIST_HEAD(&root->anon_super.s_list);
1008 INIT_LIST_HEAD(&root->anon_super.s_instances);
1009 init_rwsem(&root->anon_super.s_umount);
1010
1011 return 0;
1012 }
1013
1014 static int find_and_setup_root(struct btrfs_root *tree_root,
1015 struct btrfs_fs_info *fs_info,
1016 u64 objectid,
1017 struct btrfs_root *root)
1018 {
1019 int ret;
1020 u32 blocksize;
1021 u64 generation;
1022
1023 __setup_root(tree_root->nodesize, tree_root->leafsize,
1024 tree_root->sectorsize, tree_root->stripesize,
1025 root, fs_info, objectid);
1026 ret = btrfs_find_last_root(tree_root, objectid,
1027 &root->root_item, &root->root_key);
1028 if (ret > 0)
1029 return -ENOENT;
1030 BUG_ON(ret);
1031
1032 generation = btrfs_root_generation(&root->root_item);
1033 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1034 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1035 blocksize, generation);
1036 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1037 free_extent_buffer(root->node);
1038 return -EIO;
1039 }
1040 root->commit_root = btrfs_root_node(root);
1041 return 0;
1042 }
1043
1044 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1045 struct btrfs_fs_info *fs_info)
1046 {
1047 struct btrfs_root *root;
1048 struct btrfs_root *tree_root = fs_info->tree_root;
1049 struct extent_buffer *leaf;
1050
1051 root = kzalloc(sizeof(*root), GFP_NOFS);
1052 if (!root)
1053 return ERR_PTR(-ENOMEM);
1054
1055 __setup_root(tree_root->nodesize, tree_root->leafsize,
1056 tree_root->sectorsize, tree_root->stripesize,
1057 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1058
1059 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1060 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1061 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1062 /*
1063 * log trees do not get reference counted because they go away
1064 * before a real commit is actually done. They do store pointers
1065 * to file data extents, and those reference counts still get
1066 * updated (along with back refs to the log tree).
1067 */
1068 root->ref_cows = 0;
1069
1070 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1071 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1072 if (IS_ERR(leaf)) {
1073 kfree(root);
1074 return ERR_CAST(leaf);
1075 }
1076
1077 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1078 btrfs_set_header_bytenr(leaf, leaf->start);
1079 btrfs_set_header_generation(leaf, trans->transid);
1080 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1081 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1082 root->node = leaf;
1083
1084 write_extent_buffer(root->node, root->fs_info->fsid,
1085 (unsigned long)btrfs_header_fsid(root->node),
1086 BTRFS_FSID_SIZE);
1087 btrfs_mark_buffer_dirty(root->node);
1088 btrfs_tree_unlock(root->node);
1089 return root;
1090 }
1091
1092 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1093 struct btrfs_fs_info *fs_info)
1094 {
1095 struct btrfs_root *log_root;
1096
1097 log_root = alloc_log_tree(trans, fs_info);
1098 if (IS_ERR(log_root))
1099 return PTR_ERR(log_root);
1100 WARN_ON(fs_info->log_root_tree);
1101 fs_info->log_root_tree = log_root;
1102 return 0;
1103 }
1104
1105 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1106 struct btrfs_root *root)
1107 {
1108 struct btrfs_root *log_root;
1109 struct btrfs_inode_item *inode_item;
1110
1111 log_root = alloc_log_tree(trans, root->fs_info);
1112 if (IS_ERR(log_root))
1113 return PTR_ERR(log_root);
1114
1115 log_root->last_trans = trans->transid;
1116 log_root->root_key.offset = root->root_key.objectid;
1117
1118 inode_item = &log_root->root_item.inode;
1119 inode_item->generation = cpu_to_le64(1);
1120 inode_item->size = cpu_to_le64(3);
1121 inode_item->nlink = cpu_to_le32(1);
1122 inode_item->nbytes = cpu_to_le64(root->leafsize);
1123 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1124
1125 btrfs_set_root_node(&log_root->root_item, log_root->node);
1126
1127 WARN_ON(root->log_root);
1128 root->log_root = log_root;
1129 root->log_transid = 0;
1130 root->last_log_commit = 0;
1131 return 0;
1132 }
1133
1134 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1135 struct btrfs_key *location)
1136 {
1137 struct btrfs_root *root;
1138 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1139 struct btrfs_path *path;
1140 struct extent_buffer *l;
1141 u64 generation;
1142 u32 blocksize;
1143 int ret = 0;
1144
1145 root = kzalloc(sizeof(*root), GFP_NOFS);
1146 if (!root)
1147 return ERR_PTR(-ENOMEM);
1148 if (location->offset == (u64)-1) {
1149 ret = find_and_setup_root(tree_root, fs_info,
1150 location->objectid, root);
1151 if (ret) {
1152 kfree(root);
1153 return ERR_PTR(ret);
1154 }
1155 goto out;
1156 }
1157
1158 __setup_root(tree_root->nodesize, tree_root->leafsize,
1159 tree_root->sectorsize, tree_root->stripesize,
1160 root, fs_info, location->objectid);
1161
1162 path = btrfs_alloc_path();
1163 BUG_ON(!path);
1164 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1165 if (ret == 0) {
1166 l = path->nodes[0];
1167 read_extent_buffer(l, &root->root_item,
1168 btrfs_item_ptr_offset(l, path->slots[0]),
1169 sizeof(root->root_item));
1170 memcpy(&root->root_key, location, sizeof(*location));
1171 }
1172 btrfs_free_path(path);
1173 if (ret) {
1174 kfree(root);
1175 if (ret > 0)
1176 ret = -ENOENT;
1177 return ERR_PTR(ret);
1178 }
1179
1180 generation = btrfs_root_generation(&root->root_item);
1181 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1182 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1183 blocksize, generation);
1184 root->commit_root = btrfs_root_node(root);
1185 BUG_ON(!root->node);
1186 out:
1187 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1188 root->ref_cows = 1;
1189
1190 return root;
1191 }
1192
1193 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1194 u64 root_objectid)
1195 {
1196 struct btrfs_root *root;
1197
1198 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1199 return fs_info->tree_root;
1200 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1201 return fs_info->extent_root;
1202
1203 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1204 (unsigned long)root_objectid);
1205 return root;
1206 }
1207
1208 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1209 struct btrfs_key *location)
1210 {
1211 struct btrfs_root *root;
1212 int ret;
1213
1214 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1215 return fs_info->tree_root;
1216 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1217 return fs_info->extent_root;
1218 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1219 return fs_info->chunk_root;
1220 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1221 return fs_info->dev_root;
1222 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1223 return fs_info->csum_root;
1224 again:
1225 spin_lock(&fs_info->fs_roots_radix_lock);
1226 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1227 (unsigned long)location->objectid);
1228 spin_unlock(&fs_info->fs_roots_radix_lock);
1229 if (root)
1230 return root;
1231
1232 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1233 if (IS_ERR(root))
1234 return root;
1235
1236 set_anon_super(&root->anon_super, NULL);
1237
1238 if (btrfs_root_refs(&root->root_item) == 0) {
1239 ret = -ENOENT;
1240 goto fail;
1241 }
1242
1243 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1244 if (ret < 0)
1245 goto fail;
1246 if (ret == 0)
1247 root->orphan_item_inserted = 1;
1248
1249 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1250 if (ret)
1251 goto fail;
1252
1253 spin_lock(&fs_info->fs_roots_radix_lock);
1254 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1255 (unsigned long)root->root_key.objectid,
1256 root);
1257 if (ret == 0)
1258 root->in_radix = 1;
1259
1260 spin_unlock(&fs_info->fs_roots_radix_lock);
1261 radix_tree_preload_end();
1262 if (ret) {
1263 if (ret == -EEXIST) {
1264 free_fs_root(root);
1265 goto again;
1266 }
1267 goto fail;
1268 }
1269
1270 ret = btrfs_find_dead_roots(fs_info->tree_root,
1271 root->root_key.objectid);
1272 WARN_ON(ret);
1273 return root;
1274 fail:
1275 free_fs_root(root);
1276 return ERR_PTR(ret);
1277 }
1278
1279 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1280 struct btrfs_key *location,
1281 const char *name, int namelen)
1282 {
1283 return btrfs_read_fs_root_no_name(fs_info, location);
1284 #if 0
1285 struct btrfs_root *root;
1286 int ret;
1287
1288 root = btrfs_read_fs_root_no_name(fs_info, location);
1289 if (!root)
1290 return NULL;
1291
1292 if (root->in_sysfs)
1293 return root;
1294
1295 ret = btrfs_set_root_name(root, name, namelen);
1296 if (ret) {
1297 free_extent_buffer(root->node);
1298 kfree(root);
1299 return ERR_PTR(ret);
1300 }
1301
1302 ret = btrfs_sysfs_add_root(root);
1303 if (ret) {
1304 free_extent_buffer(root->node);
1305 kfree(root->name);
1306 kfree(root);
1307 return ERR_PTR(ret);
1308 }
1309 root->in_sysfs = 1;
1310 return root;
1311 #endif
1312 }
1313
1314 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1315 {
1316 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1317 int ret = 0;
1318 struct btrfs_device *device;
1319 struct backing_dev_info *bdi;
1320
1321 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1322 if (!device->bdev)
1323 continue;
1324 bdi = blk_get_backing_dev_info(device->bdev);
1325 if (bdi && bdi_congested(bdi, bdi_bits)) {
1326 ret = 1;
1327 break;
1328 }
1329 }
1330 return ret;
1331 }
1332
1333 /*
1334 * this unplugs every device on the box, and it is only used when page
1335 * is null
1336 */
1337 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1338 {
1339 struct btrfs_device *device;
1340 struct btrfs_fs_info *info;
1341
1342 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1343 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1344 if (!device->bdev)
1345 continue;
1346
1347 bdi = blk_get_backing_dev_info(device->bdev);
1348 if (bdi->unplug_io_fn)
1349 bdi->unplug_io_fn(bdi, page);
1350 }
1351 }
1352
1353 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1354 {
1355 struct inode *inode;
1356 struct extent_map_tree *em_tree;
1357 struct extent_map *em;
1358 struct address_space *mapping;
1359 u64 offset;
1360
1361 /* the generic O_DIRECT read code does this */
1362 if (1 || !page) {
1363 __unplug_io_fn(bdi, page);
1364 return;
1365 }
1366
1367 /*
1368 * page->mapping may change at any time. Get a consistent copy
1369 * and use that for everything below
1370 */
1371 smp_mb();
1372 mapping = page->mapping;
1373 if (!mapping)
1374 return;
1375
1376 inode = mapping->host;
1377
1378 /*
1379 * don't do the expensive searching for a small number of
1380 * devices
1381 */
1382 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1383 __unplug_io_fn(bdi, page);
1384 return;
1385 }
1386
1387 offset = page_offset(page);
1388
1389 em_tree = &BTRFS_I(inode)->extent_tree;
1390 read_lock(&em_tree->lock);
1391 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1392 read_unlock(&em_tree->lock);
1393 if (!em) {
1394 __unplug_io_fn(bdi, page);
1395 return;
1396 }
1397
1398 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1399 free_extent_map(em);
1400 __unplug_io_fn(bdi, page);
1401 return;
1402 }
1403 offset = offset - em->start;
1404 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1405 em->block_start + offset, page);
1406 free_extent_map(em);
1407 }
1408
1409 /*
1410 * If this fails, caller must call bdi_destroy() to get rid of the
1411 * bdi again.
1412 */
1413 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1414 {
1415 int err;
1416
1417 bdi->capabilities = BDI_CAP_MAP_COPY;
1418 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1419 if (err)
1420 return err;
1421
1422 bdi->ra_pages = default_backing_dev_info.ra_pages;
1423 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1424 bdi->unplug_io_data = info;
1425 bdi->congested_fn = btrfs_congested_fn;
1426 bdi->congested_data = info;
1427 return 0;
1428 }
1429
1430 static int bio_ready_for_csum(struct bio *bio)
1431 {
1432 u64 length = 0;
1433 u64 buf_len = 0;
1434 u64 start = 0;
1435 struct page *page;
1436 struct extent_io_tree *io_tree = NULL;
1437 struct bio_vec *bvec;
1438 int i;
1439 int ret;
1440
1441 bio_for_each_segment(bvec, bio, i) {
1442 page = bvec->bv_page;
1443 if (page->private == EXTENT_PAGE_PRIVATE) {
1444 length += bvec->bv_len;
1445 continue;
1446 }
1447 if (!page->private) {
1448 length += bvec->bv_len;
1449 continue;
1450 }
1451 length = bvec->bv_len;
1452 buf_len = page->private >> 2;
1453 start = page_offset(page) + bvec->bv_offset;
1454 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1455 }
1456 /* are we fully contained in this bio? */
1457 if (buf_len <= length)
1458 return 1;
1459
1460 ret = extent_range_uptodate(io_tree, start + length,
1461 start + buf_len - 1);
1462 return ret;
1463 }
1464
1465 /*
1466 * called by the kthread helper functions to finally call the bio end_io
1467 * functions. This is where read checksum verification actually happens
1468 */
1469 static void end_workqueue_fn(struct btrfs_work *work)
1470 {
1471 struct bio *bio;
1472 struct end_io_wq *end_io_wq;
1473 struct btrfs_fs_info *fs_info;
1474 int error;
1475
1476 end_io_wq = container_of(work, struct end_io_wq, work);
1477 bio = end_io_wq->bio;
1478 fs_info = end_io_wq->info;
1479
1480 /* metadata bio reads are special because the whole tree block must
1481 * be checksummed at once. This makes sure the entire block is in
1482 * ram and up to date before trying to verify things. For
1483 * blocksize <= pagesize, it is basically a noop
1484 */
1485 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1486 !bio_ready_for_csum(bio)) {
1487 btrfs_queue_worker(&fs_info->endio_meta_workers,
1488 &end_io_wq->work);
1489 return;
1490 }
1491 error = end_io_wq->error;
1492 bio->bi_private = end_io_wq->private;
1493 bio->bi_end_io = end_io_wq->end_io;
1494 kfree(end_io_wq);
1495 bio_endio(bio, error);
1496 }
1497
1498 static int cleaner_kthread(void *arg)
1499 {
1500 struct btrfs_root *root = arg;
1501
1502 do {
1503 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1504
1505 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1506 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1507 btrfs_run_delayed_iputs(root);
1508 btrfs_clean_old_snapshots(root);
1509 mutex_unlock(&root->fs_info->cleaner_mutex);
1510 }
1511
1512 if (freezing(current)) {
1513 refrigerator();
1514 } else {
1515 set_current_state(TASK_INTERRUPTIBLE);
1516 if (!kthread_should_stop())
1517 schedule();
1518 __set_current_state(TASK_RUNNING);
1519 }
1520 } while (!kthread_should_stop());
1521 return 0;
1522 }
1523
1524 static int transaction_kthread(void *arg)
1525 {
1526 struct btrfs_root *root = arg;
1527 struct btrfs_trans_handle *trans;
1528 struct btrfs_transaction *cur;
1529 u64 transid;
1530 unsigned long now;
1531 unsigned long delay;
1532 int ret;
1533
1534 do {
1535 delay = HZ * 30;
1536 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1537 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1538
1539 spin_lock(&root->fs_info->new_trans_lock);
1540 cur = root->fs_info->running_transaction;
1541 if (!cur) {
1542 spin_unlock(&root->fs_info->new_trans_lock);
1543 goto sleep;
1544 }
1545
1546 now = get_seconds();
1547 if (!cur->blocked &&
1548 (now < cur->start_time || now - cur->start_time < 30)) {
1549 spin_unlock(&root->fs_info->new_trans_lock);
1550 delay = HZ * 5;
1551 goto sleep;
1552 }
1553 transid = cur->transid;
1554 spin_unlock(&root->fs_info->new_trans_lock);
1555
1556 trans = btrfs_join_transaction(root, 1);
1557 BUG_ON(IS_ERR(trans));
1558 if (transid == trans->transid) {
1559 ret = btrfs_commit_transaction(trans, root);
1560 BUG_ON(ret);
1561 } else {
1562 btrfs_end_transaction(trans, root);
1563 }
1564 sleep:
1565 wake_up_process(root->fs_info->cleaner_kthread);
1566 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1567
1568 if (freezing(current)) {
1569 refrigerator();
1570 } else {
1571 set_current_state(TASK_INTERRUPTIBLE);
1572 if (!kthread_should_stop() &&
1573 !btrfs_transaction_blocked(root->fs_info))
1574 schedule_timeout(delay);
1575 __set_current_state(TASK_RUNNING);
1576 }
1577 } while (!kthread_should_stop());
1578 return 0;
1579 }
1580
1581 struct btrfs_root *open_ctree(struct super_block *sb,
1582 struct btrfs_fs_devices *fs_devices,
1583 char *options)
1584 {
1585 u32 sectorsize;
1586 u32 nodesize;
1587 u32 leafsize;
1588 u32 blocksize;
1589 u32 stripesize;
1590 u64 generation;
1591 u64 features;
1592 struct btrfs_key location;
1593 struct buffer_head *bh;
1594 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1595 GFP_NOFS);
1596 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1597 GFP_NOFS);
1598 struct btrfs_root *tree_root = btrfs_sb(sb);
1599 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1600 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1601 GFP_NOFS);
1602 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1603 GFP_NOFS);
1604 struct btrfs_root *log_tree_root;
1605
1606 int ret;
1607 int err = -EINVAL;
1608
1609 struct btrfs_super_block *disk_super;
1610
1611 if (!extent_root || !tree_root || !fs_info ||
1612 !chunk_root || !dev_root || !csum_root) {
1613 err = -ENOMEM;
1614 goto fail;
1615 }
1616
1617 ret = init_srcu_struct(&fs_info->subvol_srcu);
1618 if (ret) {
1619 err = ret;
1620 goto fail;
1621 }
1622
1623 ret = setup_bdi(fs_info, &fs_info->bdi);
1624 if (ret) {
1625 err = ret;
1626 goto fail_srcu;
1627 }
1628
1629 fs_info->btree_inode = new_inode(sb);
1630 if (!fs_info->btree_inode) {
1631 err = -ENOMEM;
1632 goto fail_bdi;
1633 }
1634
1635 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1636 INIT_LIST_HEAD(&fs_info->trans_list);
1637 INIT_LIST_HEAD(&fs_info->dead_roots);
1638 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1639 INIT_LIST_HEAD(&fs_info->hashers);
1640 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1641 INIT_LIST_HEAD(&fs_info->ordered_operations);
1642 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1643 spin_lock_init(&fs_info->delalloc_lock);
1644 spin_lock_init(&fs_info->new_trans_lock);
1645 spin_lock_init(&fs_info->ref_cache_lock);
1646 spin_lock_init(&fs_info->fs_roots_radix_lock);
1647 spin_lock_init(&fs_info->delayed_iput_lock);
1648
1649 init_completion(&fs_info->kobj_unregister);
1650 fs_info->tree_root = tree_root;
1651 fs_info->extent_root = extent_root;
1652 fs_info->csum_root = csum_root;
1653 fs_info->chunk_root = chunk_root;
1654 fs_info->dev_root = dev_root;
1655 fs_info->fs_devices = fs_devices;
1656 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1657 INIT_LIST_HEAD(&fs_info->space_info);
1658 btrfs_mapping_init(&fs_info->mapping_tree);
1659 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1660 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1661 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1662 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1663 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1664 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1665 mutex_init(&fs_info->durable_block_rsv_mutex);
1666 atomic_set(&fs_info->nr_async_submits, 0);
1667 atomic_set(&fs_info->async_delalloc_pages, 0);
1668 atomic_set(&fs_info->async_submit_draining, 0);
1669 atomic_set(&fs_info->nr_async_bios, 0);
1670 fs_info->sb = sb;
1671 fs_info->max_inline = 8192 * 1024;
1672 fs_info->metadata_ratio = 0;
1673
1674 fs_info->thread_pool_size = min_t(unsigned long,
1675 num_online_cpus() + 2, 8);
1676
1677 INIT_LIST_HEAD(&fs_info->ordered_extents);
1678 spin_lock_init(&fs_info->ordered_extent_lock);
1679
1680 sb->s_blocksize = 4096;
1681 sb->s_blocksize_bits = blksize_bits(4096);
1682 sb->s_bdi = &fs_info->bdi;
1683
1684 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1685 fs_info->btree_inode->i_nlink = 1;
1686 /*
1687 * we set the i_size on the btree inode to the max possible int.
1688 * the real end of the address space is determined by all of
1689 * the devices in the system
1690 */
1691 fs_info->btree_inode->i_size = OFFSET_MAX;
1692 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1693 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1694
1695 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1696 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1697 fs_info->btree_inode->i_mapping,
1698 GFP_NOFS);
1699 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1700 GFP_NOFS);
1701
1702 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1703
1704 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1705 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1706 sizeof(struct btrfs_key));
1707 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1708 insert_inode_hash(fs_info->btree_inode);
1709
1710 spin_lock_init(&fs_info->block_group_cache_lock);
1711 fs_info->block_group_cache_tree = RB_ROOT;
1712
1713 extent_io_tree_init(&fs_info->freed_extents[0],
1714 fs_info->btree_inode->i_mapping, GFP_NOFS);
1715 extent_io_tree_init(&fs_info->freed_extents[1],
1716 fs_info->btree_inode->i_mapping, GFP_NOFS);
1717 fs_info->pinned_extents = &fs_info->freed_extents[0];
1718 fs_info->do_barriers = 1;
1719
1720
1721 mutex_init(&fs_info->trans_mutex);
1722 mutex_init(&fs_info->ordered_operations_mutex);
1723 mutex_init(&fs_info->tree_log_mutex);
1724 mutex_init(&fs_info->chunk_mutex);
1725 mutex_init(&fs_info->transaction_kthread_mutex);
1726 mutex_init(&fs_info->cleaner_mutex);
1727 mutex_init(&fs_info->volume_mutex);
1728 init_rwsem(&fs_info->extent_commit_sem);
1729 init_rwsem(&fs_info->cleanup_work_sem);
1730 init_rwsem(&fs_info->subvol_sem);
1731
1732 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1733 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1734
1735 init_waitqueue_head(&fs_info->transaction_throttle);
1736 init_waitqueue_head(&fs_info->transaction_wait);
1737 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1738 init_waitqueue_head(&fs_info->async_submit_wait);
1739
1740 __setup_root(4096, 4096, 4096, 4096, tree_root,
1741 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1742
1743 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1744 if (!bh) {
1745 err = -EINVAL;
1746 goto fail_iput;
1747 }
1748
1749 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1750 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1751 sizeof(fs_info->super_for_commit));
1752 brelse(bh);
1753
1754 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1755
1756 disk_super = &fs_info->super_copy;
1757 if (!btrfs_super_root(disk_super))
1758 goto fail_iput;
1759
1760 /* check FS state, whether FS is broken. */
1761 fs_info->fs_state |= btrfs_super_flags(disk_super);
1762
1763 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1764
1765 ret = btrfs_parse_options(tree_root, options);
1766 if (ret) {
1767 err = ret;
1768 goto fail_iput;
1769 }
1770
1771 features = btrfs_super_incompat_flags(disk_super) &
1772 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1773 if (features) {
1774 printk(KERN_ERR "BTRFS: couldn't mount because of "
1775 "unsupported optional features (%Lx).\n",
1776 (unsigned long long)features);
1777 err = -EINVAL;
1778 goto fail_iput;
1779 }
1780
1781 features = btrfs_super_incompat_flags(disk_super);
1782 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1783 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1784 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1785 btrfs_set_super_incompat_flags(disk_super, features);
1786
1787 features = btrfs_super_compat_ro_flags(disk_super) &
1788 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1789 if (!(sb->s_flags & MS_RDONLY) && features) {
1790 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1791 "unsupported option features (%Lx).\n",
1792 (unsigned long long)features);
1793 err = -EINVAL;
1794 goto fail_iput;
1795 }
1796
1797 btrfs_init_workers(&fs_info->generic_worker,
1798 "genwork", 1, NULL);
1799
1800 btrfs_init_workers(&fs_info->workers, "worker",
1801 fs_info->thread_pool_size,
1802 &fs_info->generic_worker);
1803
1804 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1805 fs_info->thread_pool_size,
1806 &fs_info->generic_worker);
1807
1808 btrfs_init_workers(&fs_info->submit_workers, "submit",
1809 min_t(u64, fs_devices->num_devices,
1810 fs_info->thread_pool_size),
1811 &fs_info->generic_worker);
1812
1813 /* a higher idle thresh on the submit workers makes it much more
1814 * likely that bios will be send down in a sane order to the
1815 * devices
1816 */
1817 fs_info->submit_workers.idle_thresh = 64;
1818
1819 fs_info->workers.idle_thresh = 16;
1820 fs_info->workers.ordered = 1;
1821
1822 fs_info->delalloc_workers.idle_thresh = 2;
1823 fs_info->delalloc_workers.ordered = 1;
1824
1825 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1826 &fs_info->generic_worker);
1827 btrfs_init_workers(&fs_info->endio_workers, "endio",
1828 fs_info->thread_pool_size,
1829 &fs_info->generic_worker);
1830 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1831 fs_info->thread_pool_size,
1832 &fs_info->generic_worker);
1833 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1834 "endio-meta-write", fs_info->thread_pool_size,
1835 &fs_info->generic_worker);
1836 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1837 fs_info->thread_pool_size,
1838 &fs_info->generic_worker);
1839 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1840 1, &fs_info->generic_worker);
1841
1842 /*
1843 * endios are largely parallel and should have a very
1844 * low idle thresh
1845 */
1846 fs_info->endio_workers.idle_thresh = 4;
1847 fs_info->endio_meta_workers.idle_thresh = 4;
1848
1849 fs_info->endio_write_workers.idle_thresh = 2;
1850 fs_info->endio_meta_write_workers.idle_thresh = 2;
1851
1852 btrfs_start_workers(&fs_info->workers, 1);
1853 btrfs_start_workers(&fs_info->generic_worker, 1);
1854 btrfs_start_workers(&fs_info->submit_workers, 1);
1855 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1856 btrfs_start_workers(&fs_info->fixup_workers, 1);
1857 btrfs_start_workers(&fs_info->endio_workers, 1);
1858 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1859 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1860 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1861 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1862
1863 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1864 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1865 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1866
1867 nodesize = btrfs_super_nodesize(disk_super);
1868 leafsize = btrfs_super_leafsize(disk_super);
1869 sectorsize = btrfs_super_sectorsize(disk_super);
1870 stripesize = btrfs_super_stripesize(disk_super);
1871 tree_root->nodesize = nodesize;
1872 tree_root->leafsize = leafsize;
1873 tree_root->sectorsize = sectorsize;
1874 tree_root->stripesize = stripesize;
1875
1876 sb->s_blocksize = sectorsize;
1877 sb->s_blocksize_bits = blksize_bits(sectorsize);
1878
1879 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1880 sizeof(disk_super->magic))) {
1881 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1882 goto fail_sb_buffer;
1883 }
1884
1885 mutex_lock(&fs_info->chunk_mutex);
1886 ret = btrfs_read_sys_array(tree_root);
1887 mutex_unlock(&fs_info->chunk_mutex);
1888 if (ret) {
1889 printk(KERN_WARNING "btrfs: failed to read the system "
1890 "array on %s\n", sb->s_id);
1891 goto fail_sb_buffer;
1892 }
1893
1894 blocksize = btrfs_level_size(tree_root,
1895 btrfs_super_chunk_root_level(disk_super));
1896 generation = btrfs_super_chunk_root_generation(disk_super);
1897
1898 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1899 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1900
1901 chunk_root->node = read_tree_block(chunk_root,
1902 btrfs_super_chunk_root(disk_super),
1903 blocksize, generation);
1904 BUG_ON(!chunk_root->node);
1905 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1906 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1907 sb->s_id);
1908 goto fail_chunk_root;
1909 }
1910 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1911 chunk_root->commit_root = btrfs_root_node(chunk_root);
1912
1913 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1914 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1915 BTRFS_UUID_SIZE);
1916
1917 mutex_lock(&fs_info->chunk_mutex);
1918 ret = btrfs_read_chunk_tree(chunk_root);
1919 mutex_unlock(&fs_info->chunk_mutex);
1920 if (ret) {
1921 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1922 sb->s_id);
1923 goto fail_chunk_root;
1924 }
1925
1926 btrfs_close_extra_devices(fs_devices);
1927
1928 blocksize = btrfs_level_size(tree_root,
1929 btrfs_super_root_level(disk_super));
1930 generation = btrfs_super_generation(disk_super);
1931
1932 tree_root->node = read_tree_block(tree_root,
1933 btrfs_super_root(disk_super),
1934 blocksize, generation);
1935 if (!tree_root->node)
1936 goto fail_chunk_root;
1937 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1938 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1939 sb->s_id);
1940 goto fail_tree_root;
1941 }
1942 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1943 tree_root->commit_root = btrfs_root_node(tree_root);
1944
1945 ret = find_and_setup_root(tree_root, fs_info,
1946 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1947 if (ret)
1948 goto fail_tree_root;
1949 extent_root->track_dirty = 1;
1950
1951 ret = find_and_setup_root(tree_root, fs_info,
1952 BTRFS_DEV_TREE_OBJECTID, dev_root);
1953 if (ret)
1954 goto fail_extent_root;
1955 dev_root->track_dirty = 1;
1956
1957 ret = find_and_setup_root(tree_root, fs_info,
1958 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1959 if (ret)
1960 goto fail_dev_root;
1961
1962 csum_root->track_dirty = 1;
1963
1964 fs_info->generation = generation;
1965 fs_info->last_trans_committed = generation;
1966 fs_info->data_alloc_profile = (u64)-1;
1967 fs_info->metadata_alloc_profile = (u64)-1;
1968 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1969
1970 ret = btrfs_read_block_groups(extent_root);
1971 if (ret) {
1972 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1973 goto fail_block_groups;
1974 }
1975
1976 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1977 "btrfs-cleaner");
1978 if (IS_ERR(fs_info->cleaner_kthread))
1979 goto fail_block_groups;
1980
1981 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1982 tree_root,
1983 "btrfs-transaction");
1984 if (IS_ERR(fs_info->transaction_kthread))
1985 goto fail_cleaner;
1986
1987 if (!btrfs_test_opt(tree_root, SSD) &&
1988 !btrfs_test_opt(tree_root, NOSSD) &&
1989 !fs_info->fs_devices->rotating) {
1990 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1991 "mode\n");
1992 btrfs_set_opt(fs_info->mount_opt, SSD);
1993 }
1994
1995 /* do not make disk changes in broken FS */
1996 if (btrfs_super_log_root(disk_super) != 0 &&
1997 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
1998 u64 bytenr = btrfs_super_log_root(disk_super);
1999
2000 if (fs_devices->rw_devices == 0) {
2001 printk(KERN_WARNING "Btrfs log replay required "
2002 "on RO media\n");
2003 err = -EIO;
2004 goto fail_trans_kthread;
2005 }
2006 blocksize =
2007 btrfs_level_size(tree_root,
2008 btrfs_super_log_root_level(disk_super));
2009
2010 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2011 if (!log_tree_root) {
2012 err = -ENOMEM;
2013 goto fail_trans_kthread;
2014 }
2015
2016 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2017 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2018
2019 log_tree_root->node = read_tree_block(tree_root, bytenr,
2020 blocksize,
2021 generation + 1);
2022 ret = btrfs_recover_log_trees(log_tree_root);
2023 BUG_ON(ret);
2024
2025 if (sb->s_flags & MS_RDONLY) {
2026 ret = btrfs_commit_super(tree_root);
2027 BUG_ON(ret);
2028 }
2029 }
2030
2031 ret = btrfs_find_orphan_roots(tree_root);
2032 BUG_ON(ret);
2033
2034 if (!(sb->s_flags & MS_RDONLY)) {
2035 ret = btrfs_cleanup_fs_roots(fs_info);
2036 BUG_ON(ret);
2037
2038 ret = btrfs_recover_relocation(tree_root);
2039 if (ret < 0) {
2040 printk(KERN_WARNING
2041 "btrfs: failed to recover relocation\n");
2042 err = -EINVAL;
2043 goto fail_trans_kthread;
2044 }
2045 }
2046
2047 location.objectid = BTRFS_FS_TREE_OBJECTID;
2048 location.type = BTRFS_ROOT_ITEM_KEY;
2049 location.offset = (u64)-1;
2050
2051 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2052 if (!fs_info->fs_root)
2053 goto fail_trans_kthread;
2054 if (IS_ERR(fs_info->fs_root)) {
2055 err = PTR_ERR(fs_info->fs_root);
2056 goto fail_trans_kthread;
2057 }
2058
2059 if (!(sb->s_flags & MS_RDONLY)) {
2060 down_read(&fs_info->cleanup_work_sem);
2061 btrfs_orphan_cleanup(fs_info->fs_root);
2062 btrfs_orphan_cleanup(fs_info->tree_root);
2063 up_read(&fs_info->cleanup_work_sem);
2064 }
2065
2066 return tree_root;
2067
2068 fail_trans_kthread:
2069 kthread_stop(fs_info->transaction_kthread);
2070 fail_cleaner:
2071 kthread_stop(fs_info->cleaner_kthread);
2072
2073 /*
2074 * make sure we're done with the btree inode before we stop our
2075 * kthreads
2076 */
2077 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2078 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2079
2080 fail_block_groups:
2081 btrfs_free_block_groups(fs_info);
2082 free_extent_buffer(csum_root->node);
2083 free_extent_buffer(csum_root->commit_root);
2084 fail_dev_root:
2085 free_extent_buffer(dev_root->node);
2086 free_extent_buffer(dev_root->commit_root);
2087 fail_extent_root:
2088 free_extent_buffer(extent_root->node);
2089 free_extent_buffer(extent_root->commit_root);
2090 fail_tree_root:
2091 free_extent_buffer(tree_root->node);
2092 free_extent_buffer(tree_root->commit_root);
2093 fail_chunk_root:
2094 free_extent_buffer(chunk_root->node);
2095 free_extent_buffer(chunk_root->commit_root);
2096 fail_sb_buffer:
2097 btrfs_stop_workers(&fs_info->generic_worker);
2098 btrfs_stop_workers(&fs_info->fixup_workers);
2099 btrfs_stop_workers(&fs_info->delalloc_workers);
2100 btrfs_stop_workers(&fs_info->workers);
2101 btrfs_stop_workers(&fs_info->endio_workers);
2102 btrfs_stop_workers(&fs_info->endio_meta_workers);
2103 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2104 btrfs_stop_workers(&fs_info->endio_write_workers);
2105 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2106 btrfs_stop_workers(&fs_info->submit_workers);
2107 fail_iput:
2108 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2109 iput(fs_info->btree_inode);
2110
2111 btrfs_close_devices(fs_info->fs_devices);
2112 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2113 fail_bdi:
2114 bdi_destroy(&fs_info->bdi);
2115 fail_srcu:
2116 cleanup_srcu_struct(&fs_info->subvol_srcu);
2117 fail:
2118 kfree(extent_root);
2119 kfree(tree_root);
2120 kfree(fs_info);
2121 kfree(chunk_root);
2122 kfree(dev_root);
2123 kfree(csum_root);
2124 return ERR_PTR(err);
2125 }
2126
2127 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2128 {
2129 char b[BDEVNAME_SIZE];
2130
2131 if (uptodate) {
2132 set_buffer_uptodate(bh);
2133 } else {
2134 if (printk_ratelimit()) {
2135 printk(KERN_WARNING "lost page write due to "
2136 "I/O error on %s\n",
2137 bdevname(bh->b_bdev, b));
2138 }
2139 /* note, we dont' set_buffer_write_io_error because we have
2140 * our own ways of dealing with the IO errors
2141 */
2142 clear_buffer_uptodate(bh);
2143 }
2144 unlock_buffer(bh);
2145 put_bh(bh);
2146 }
2147
2148 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2149 {
2150 struct buffer_head *bh;
2151 struct buffer_head *latest = NULL;
2152 struct btrfs_super_block *super;
2153 int i;
2154 u64 transid = 0;
2155 u64 bytenr;
2156
2157 /* we would like to check all the supers, but that would make
2158 * a btrfs mount succeed after a mkfs from a different FS.
2159 * So, we need to add a special mount option to scan for
2160 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2161 */
2162 for (i = 0; i < 1; i++) {
2163 bytenr = btrfs_sb_offset(i);
2164 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2165 break;
2166 bh = __bread(bdev, bytenr / 4096, 4096);
2167 if (!bh)
2168 continue;
2169
2170 super = (struct btrfs_super_block *)bh->b_data;
2171 if (btrfs_super_bytenr(super) != bytenr ||
2172 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2173 sizeof(super->magic))) {
2174 brelse(bh);
2175 continue;
2176 }
2177
2178 if (!latest || btrfs_super_generation(super) > transid) {
2179 brelse(latest);
2180 latest = bh;
2181 transid = btrfs_super_generation(super);
2182 } else {
2183 brelse(bh);
2184 }
2185 }
2186 return latest;
2187 }
2188
2189 /*
2190 * this should be called twice, once with wait == 0 and
2191 * once with wait == 1. When wait == 0 is done, all the buffer heads
2192 * we write are pinned.
2193 *
2194 * They are released when wait == 1 is done.
2195 * max_mirrors must be the same for both runs, and it indicates how
2196 * many supers on this one device should be written.
2197 *
2198 * max_mirrors == 0 means to write them all.
2199 */
2200 static int write_dev_supers(struct btrfs_device *device,
2201 struct btrfs_super_block *sb,
2202 int do_barriers, int wait, int max_mirrors)
2203 {
2204 struct buffer_head *bh;
2205 int i;
2206 int ret;
2207 int errors = 0;
2208 u32 crc;
2209 u64 bytenr;
2210 int last_barrier = 0;
2211
2212 if (max_mirrors == 0)
2213 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2214
2215 /* make sure only the last submit_bh does a barrier */
2216 if (do_barriers) {
2217 for (i = 0; i < max_mirrors; i++) {
2218 bytenr = btrfs_sb_offset(i);
2219 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2220 device->total_bytes)
2221 break;
2222 last_barrier = i;
2223 }
2224 }
2225
2226 for (i = 0; i < max_mirrors; i++) {
2227 bytenr = btrfs_sb_offset(i);
2228 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2229 break;
2230
2231 if (wait) {
2232 bh = __find_get_block(device->bdev, bytenr / 4096,
2233 BTRFS_SUPER_INFO_SIZE);
2234 BUG_ON(!bh);
2235 wait_on_buffer(bh);
2236 if (!buffer_uptodate(bh))
2237 errors++;
2238
2239 /* drop our reference */
2240 brelse(bh);
2241
2242 /* drop the reference from the wait == 0 run */
2243 brelse(bh);
2244 continue;
2245 } else {
2246 btrfs_set_super_bytenr(sb, bytenr);
2247
2248 crc = ~(u32)0;
2249 crc = btrfs_csum_data(NULL, (char *)sb +
2250 BTRFS_CSUM_SIZE, crc,
2251 BTRFS_SUPER_INFO_SIZE -
2252 BTRFS_CSUM_SIZE);
2253 btrfs_csum_final(crc, sb->csum);
2254
2255 /*
2256 * one reference for us, and we leave it for the
2257 * caller
2258 */
2259 bh = __getblk(device->bdev, bytenr / 4096,
2260 BTRFS_SUPER_INFO_SIZE);
2261 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2262
2263 /* one reference for submit_bh */
2264 get_bh(bh);
2265
2266 set_buffer_uptodate(bh);
2267 lock_buffer(bh);
2268 bh->b_end_io = btrfs_end_buffer_write_sync;
2269 }
2270
2271 if (i == last_barrier && do_barriers)
2272 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2273 else
2274 ret = submit_bh(WRITE_SYNC, bh);
2275
2276 if (ret)
2277 errors++;
2278 }
2279 return errors < i ? 0 : -1;
2280 }
2281
2282 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2283 {
2284 struct list_head *head;
2285 struct btrfs_device *dev;
2286 struct btrfs_super_block *sb;
2287 struct btrfs_dev_item *dev_item;
2288 int ret;
2289 int do_barriers;
2290 int max_errors;
2291 int total_errors = 0;
2292 u64 flags;
2293
2294 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2295 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2296
2297 sb = &root->fs_info->super_for_commit;
2298 dev_item = &sb->dev_item;
2299
2300 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2301 head = &root->fs_info->fs_devices->devices;
2302 list_for_each_entry(dev, head, dev_list) {
2303 if (!dev->bdev) {
2304 total_errors++;
2305 continue;
2306 }
2307 if (!dev->in_fs_metadata || !dev->writeable)
2308 continue;
2309
2310 btrfs_set_stack_device_generation(dev_item, 0);
2311 btrfs_set_stack_device_type(dev_item, dev->type);
2312 btrfs_set_stack_device_id(dev_item, dev->devid);
2313 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2314 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2315 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2316 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2317 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2318 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2319 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2320
2321 flags = btrfs_super_flags(sb);
2322 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2323
2324 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2325 if (ret)
2326 total_errors++;
2327 }
2328 if (total_errors > max_errors) {
2329 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2330 total_errors);
2331 BUG();
2332 }
2333
2334 total_errors = 0;
2335 list_for_each_entry(dev, head, dev_list) {
2336 if (!dev->bdev)
2337 continue;
2338 if (!dev->in_fs_metadata || !dev->writeable)
2339 continue;
2340
2341 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2342 if (ret)
2343 total_errors++;
2344 }
2345 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2346 if (total_errors > max_errors) {
2347 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2348 total_errors);
2349 BUG();
2350 }
2351 return 0;
2352 }
2353
2354 int write_ctree_super(struct btrfs_trans_handle *trans,
2355 struct btrfs_root *root, int max_mirrors)
2356 {
2357 int ret;
2358
2359 ret = write_all_supers(root, max_mirrors);
2360 return ret;
2361 }
2362
2363 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2364 {
2365 spin_lock(&fs_info->fs_roots_radix_lock);
2366 radix_tree_delete(&fs_info->fs_roots_radix,
2367 (unsigned long)root->root_key.objectid);
2368 spin_unlock(&fs_info->fs_roots_radix_lock);
2369
2370 if (btrfs_root_refs(&root->root_item) == 0)
2371 synchronize_srcu(&fs_info->subvol_srcu);
2372
2373 free_fs_root(root);
2374 return 0;
2375 }
2376
2377 static void free_fs_root(struct btrfs_root *root)
2378 {
2379 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2380 if (root->anon_super.s_dev) {
2381 down_write(&root->anon_super.s_umount);
2382 kill_anon_super(&root->anon_super);
2383 }
2384 free_extent_buffer(root->node);
2385 free_extent_buffer(root->commit_root);
2386 kfree(root->name);
2387 kfree(root);
2388 }
2389
2390 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2391 {
2392 int ret;
2393 struct btrfs_root *gang[8];
2394 int i;
2395
2396 while (!list_empty(&fs_info->dead_roots)) {
2397 gang[0] = list_entry(fs_info->dead_roots.next,
2398 struct btrfs_root, root_list);
2399 list_del(&gang[0]->root_list);
2400
2401 if (gang[0]->in_radix) {
2402 btrfs_free_fs_root(fs_info, gang[0]);
2403 } else {
2404 free_extent_buffer(gang[0]->node);
2405 free_extent_buffer(gang[0]->commit_root);
2406 kfree(gang[0]);
2407 }
2408 }
2409
2410 while (1) {
2411 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2412 (void **)gang, 0,
2413 ARRAY_SIZE(gang));
2414 if (!ret)
2415 break;
2416 for (i = 0; i < ret; i++)
2417 btrfs_free_fs_root(fs_info, gang[i]);
2418 }
2419 return 0;
2420 }
2421
2422 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2423 {
2424 u64 root_objectid = 0;
2425 struct btrfs_root *gang[8];
2426 int i;
2427 int ret;
2428
2429 while (1) {
2430 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2431 (void **)gang, root_objectid,
2432 ARRAY_SIZE(gang));
2433 if (!ret)
2434 break;
2435
2436 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2437 for (i = 0; i < ret; i++) {
2438 root_objectid = gang[i]->root_key.objectid;
2439 btrfs_orphan_cleanup(gang[i]);
2440 }
2441 root_objectid++;
2442 }
2443 return 0;
2444 }
2445
2446 int btrfs_commit_super(struct btrfs_root *root)
2447 {
2448 struct btrfs_trans_handle *trans;
2449 int ret;
2450
2451 mutex_lock(&root->fs_info->cleaner_mutex);
2452 btrfs_run_delayed_iputs(root);
2453 btrfs_clean_old_snapshots(root);
2454 mutex_unlock(&root->fs_info->cleaner_mutex);
2455
2456 /* wait until ongoing cleanup work done */
2457 down_write(&root->fs_info->cleanup_work_sem);
2458 up_write(&root->fs_info->cleanup_work_sem);
2459
2460 trans = btrfs_join_transaction(root, 1);
2461 if (IS_ERR(trans))
2462 return PTR_ERR(trans);
2463 ret = btrfs_commit_transaction(trans, root);
2464 BUG_ON(ret);
2465 /* run commit again to drop the original snapshot */
2466 trans = btrfs_join_transaction(root, 1);
2467 if (IS_ERR(trans))
2468 return PTR_ERR(trans);
2469 btrfs_commit_transaction(trans, root);
2470 ret = btrfs_write_and_wait_transaction(NULL, root);
2471 BUG_ON(ret);
2472
2473 ret = write_ctree_super(NULL, root, 0);
2474 return ret;
2475 }
2476
2477 int close_ctree(struct btrfs_root *root)
2478 {
2479 struct btrfs_fs_info *fs_info = root->fs_info;
2480 int ret;
2481
2482 fs_info->closing = 1;
2483 smp_mb();
2484
2485 btrfs_put_block_group_cache(fs_info);
2486
2487 /*
2488 * Here come 2 situations when btrfs is broken to flip readonly:
2489 *
2490 * 1. when btrfs flips readonly somewhere else before
2491 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2492 * and btrfs will skip to write sb directly to keep
2493 * ERROR state on disk.
2494 *
2495 * 2. when btrfs flips readonly just in btrfs_commit_super,
2496 * and in such case, btrfs cannnot write sb via btrfs_commit_super,
2497 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2498 * btrfs will cleanup all FS resources first and write sb then.
2499 */
2500 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2501 ret = btrfs_commit_super(root);
2502 if (ret)
2503 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2504 }
2505
2506 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2507 ret = btrfs_error_commit_super(root);
2508 if (ret)
2509 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2510 }
2511
2512 kthread_stop(root->fs_info->transaction_kthread);
2513 kthread_stop(root->fs_info->cleaner_kthread);
2514
2515 fs_info->closing = 2;
2516 smp_mb();
2517
2518 if (fs_info->delalloc_bytes) {
2519 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2520 (unsigned long long)fs_info->delalloc_bytes);
2521 }
2522 if (fs_info->total_ref_cache_size) {
2523 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2524 (unsigned long long)fs_info->total_ref_cache_size);
2525 }
2526
2527 free_extent_buffer(fs_info->extent_root->node);
2528 free_extent_buffer(fs_info->extent_root->commit_root);
2529 free_extent_buffer(fs_info->tree_root->node);
2530 free_extent_buffer(fs_info->tree_root->commit_root);
2531 free_extent_buffer(root->fs_info->chunk_root->node);
2532 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2533 free_extent_buffer(root->fs_info->dev_root->node);
2534 free_extent_buffer(root->fs_info->dev_root->commit_root);
2535 free_extent_buffer(root->fs_info->csum_root->node);
2536 free_extent_buffer(root->fs_info->csum_root->commit_root);
2537
2538 btrfs_free_block_groups(root->fs_info);
2539
2540 del_fs_roots(fs_info);
2541
2542 iput(fs_info->btree_inode);
2543
2544 btrfs_stop_workers(&fs_info->generic_worker);
2545 btrfs_stop_workers(&fs_info->fixup_workers);
2546 btrfs_stop_workers(&fs_info->delalloc_workers);
2547 btrfs_stop_workers(&fs_info->workers);
2548 btrfs_stop_workers(&fs_info->endio_workers);
2549 btrfs_stop_workers(&fs_info->endio_meta_workers);
2550 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2551 btrfs_stop_workers(&fs_info->endio_write_workers);
2552 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2553 btrfs_stop_workers(&fs_info->submit_workers);
2554
2555 btrfs_close_devices(fs_info->fs_devices);
2556 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2557
2558 bdi_destroy(&fs_info->bdi);
2559 cleanup_srcu_struct(&fs_info->subvol_srcu);
2560
2561 kfree(fs_info->extent_root);
2562 kfree(fs_info->tree_root);
2563 kfree(fs_info->chunk_root);
2564 kfree(fs_info->dev_root);
2565 kfree(fs_info->csum_root);
2566 kfree(fs_info);
2567
2568 return 0;
2569 }
2570
2571 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2572 {
2573 int ret;
2574 struct inode *btree_inode = buf->first_page->mapping->host;
2575
2576 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2577 NULL);
2578 if (!ret)
2579 return ret;
2580
2581 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2582 parent_transid);
2583 return !ret;
2584 }
2585
2586 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2587 {
2588 struct inode *btree_inode = buf->first_page->mapping->host;
2589 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2590 buf);
2591 }
2592
2593 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2594 {
2595 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2596 u64 transid = btrfs_header_generation(buf);
2597 struct inode *btree_inode = root->fs_info->btree_inode;
2598 int was_dirty;
2599
2600 btrfs_assert_tree_locked(buf);
2601 if (transid != root->fs_info->generation) {
2602 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2603 "found %llu running %llu\n",
2604 (unsigned long long)buf->start,
2605 (unsigned long long)transid,
2606 (unsigned long long)root->fs_info->generation);
2607 WARN_ON(1);
2608 }
2609 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2610 buf);
2611 if (!was_dirty) {
2612 spin_lock(&root->fs_info->delalloc_lock);
2613 root->fs_info->dirty_metadata_bytes += buf->len;
2614 spin_unlock(&root->fs_info->delalloc_lock);
2615 }
2616 }
2617
2618 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2619 {
2620 /*
2621 * looks as though older kernels can get into trouble with
2622 * this code, they end up stuck in balance_dirty_pages forever
2623 */
2624 u64 num_dirty;
2625 unsigned long thresh = 32 * 1024 * 1024;
2626
2627 if (current->flags & PF_MEMALLOC)
2628 return;
2629
2630 num_dirty = root->fs_info->dirty_metadata_bytes;
2631
2632 if (num_dirty > thresh) {
2633 balance_dirty_pages_ratelimited_nr(
2634 root->fs_info->btree_inode->i_mapping, 1);
2635 }
2636 return;
2637 }
2638
2639 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2640 {
2641 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2642 int ret;
2643 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2644 if (ret == 0)
2645 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2646 return ret;
2647 }
2648
2649 int btree_lock_page_hook(struct page *page)
2650 {
2651 struct inode *inode = page->mapping->host;
2652 struct btrfs_root *root = BTRFS_I(inode)->root;
2653 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2654 struct extent_buffer *eb;
2655 unsigned long len;
2656 u64 bytenr = page_offset(page);
2657
2658 if (page->private == EXTENT_PAGE_PRIVATE)
2659 goto out;
2660
2661 len = page->private >> 2;
2662 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2663 if (!eb)
2664 goto out;
2665
2666 btrfs_tree_lock(eb);
2667 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2668
2669 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2670 spin_lock(&root->fs_info->delalloc_lock);
2671 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2672 root->fs_info->dirty_metadata_bytes -= eb->len;
2673 else
2674 WARN_ON(1);
2675 spin_unlock(&root->fs_info->delalloc_lock);
2676 }
2677
2678 btrfs_tree_unlock(eb);
2679 free_extent_buffer(eb);
2680 out:
2681 lock_page(page);
2682 return 0;
2683 }
2684
2685 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2686 int read_only)
2687 {
2688 if (read_only)
2689 return;
2690
2691 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2692 printk(KERN_WARNING "warning: mount fs with errors, "
2693 "running btrfsck is recommended\n");
2694 }
2695
2696 int btrfs_error_commit_super(struct btrfs_root *root)
2697 {
2698 int ret;
2699
2700 mutex_lock(&root->fs_info->cleaner_mutex);
2701 btrfs_run_delayed_iputs(root);
2702 mutex_unlock(&root->fs_info->cleaner_mutex);
2703
2704 down_write(&root->fs_info->cleanup_work_sem);
2705 up_write(&root->fs_info->cleanup_work_sem);
2706
2707 /* cleanup FS via transaction */
2708 btrfs_cleanup_transaction(root);
2709
2710 ret = write_ctree_super(NULL, root, 0);
2711
2712 return ret;
2713 }
2714
2715 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2716 {
2717 struct btrfs_inode *btrfs_inode;
2718 struct list_head splice;
2719
2720 INIT_LIST_HEAD(&splice);
2721
2722 mutex_lock(&root->fs_info->ordered_operations_mutex);
2723 spin_lock(&root->fs_info->ordered_extent_lock);
2724
2725 list_splice_init(&root->fs_info->ordered_operations, &splice);
2726 while (!list_empty(&splice)) {
2727 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2728 ordered_operations);
2729
2730 list_del_init(&btrfs_inode->ordered_operations);
2731
2732 btrfs_invalidate_inodes(btrfs_inode->root);
2733 }
2734
2735 spin_unlock(&root->fs_info->ordered_extent_lock);
2736 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2737
2738 return 0;
2739 }
2740
2741 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2742 {
2743 struct list_head splice;
2744 struct btrfs_ordered_extent *ordered;
2745 struct inode *inode;
2746
2747 INIT_LIST_HEAD(&splice);
2748
2749 spin_lock(&root->fs_info->ordered_extent_lock);
2750
2751 list_splice_init(&root->fs_info->ordered_extents, &splice);
2752 while (!list_empty(&splice)) {
2753 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2754 root_extent_list);
2755
2756 list_del_init(&ordered->root_extent_list);
2757 atomic_inc(&ordered->refs);
2758
2759 /* the inode may be getting freed (in sys_unlink path). */
2760 inode = igrab(ordered->inode);
2761
2762 spin_unlock(&root->fs_info->ordered_extent_lock);
2763 if (inode)
2764 iput(inode);
2765
2766 atomic_set(&ordered->refs, 1);
2767 btrfs_put_ordered_extent(ordered);
2768
2769 spin_lock(&root->fs_info->ordered_extent_lock);
2770 }
2771
2772 spin_unlock(&root->fs_info->ordered_extent_lock);
2773
2774 return 0;
2775 }
2776
2777 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2778 struct btrfs_root *root)
2779 {
2780 struct rb_node *node;
2781 struct btrfs_delayed_ref_root *delayed_refs;
2782 struct btrfs_delayed_ref_node *ref;
2783 int ret = 0;
2784
2785 delayed_refs = &trans->delayed_refs;
2786
2787 spin_lock(&delayed_refs->lock);
2788 if (delayed_refs->num_entries == 0) {
2789 printk(KERN_INFO "delayed_refs has NO entry\n");
2790 return ret;
2791 }
2792
2793 node = rb_first(&delayed_refs->root);
2794 while (node) {
2795 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2796 node = rb_next(node);
2797
2798 ref->in_tree = 0;
2799 rb_erase(&ref->rb_node, &delayed_refs->root);
2800 delayed_refs->num_entries--;
2801
2802 atomic_set(&ref->refs, 1);
2803 if (btrfs_delayed_ref_is_head(ref)) {
2804 struct btrfs_delayed_ref_head *head;
2805
2806 head = btrfs_delayed_node_to_head(ref);
2807 mutex_lock(&head->mutex);
2808 kfree(head->extent_op);
2809 delayed_refs->num_heads--;
2810 if (list_empty(&head->cluster))
2811 delayed_refs->num_heads_ready--;
2812 list_del_init(&head->cluster);
2813 mutex_unlock(&head->mutex);
2814 }
2815
2816 spin_unlock(&delayed_refs->lock);
2817 btrfs_put_delayed_ref(ref);
2818
2819 cond_resched();
2820 spin_lock(&delayed_refs->lock);
2821 }
2822
2823 spin_unlock(&delayed_refs->lock);
2824
2825 return ret;
2826 }
2827
2828 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2829 {
2830 struct btrfs_pending_snapshot *snapshot;
2831 struct list_head splice;
2832
2833 INIT_LIST_HEAD(&splice);
2834
2835 list_splice_init(&t->pending_snapshots, &splice);
2836
2837 while (!list_empty(&splice)) {
2838 snapshot = list_entry(splice.next,
2839 struct btrfs_pending_snapshot,
2840 list);
2841
2842 list_del_init(&snapshot->list);
2843
2844 kfree(snapshot);
2845 }
2846
2847 return 0;
2848 }
2849
2850 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2851 {
2852 struct btrfs_inode *btrfs_inode;
2853 struct list_head splice;
2854
2855 INIT_LIST_HEAD(&splice);
2856
2857 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2858
2859 spin_lock(&root->fs_info->delalloc_lock);
2860
2861 while (!list_empty(&splice)) {
2862 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2863 delalloc_inodes);
2864
2865 list_del_init(&btrfs_inode->delalloc_inodes);
2866
2867 btrfs_invalidate_inodes(btrfs_inode->root);
2868 }
2869
2870 spin_unlock(&root->fs_info->delalloc_lock);
2871
2872 return 0;
2873 }
2874
2875 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2876 struct extent_io_tree *dirty_pages,
2877 int mark)
2878 {
2879 int ret;
2880 struct page *page;
2881 struct inode *btree_inode = root->fs_info->btree_inode;
2882 struct extent_buffer *eb;
2883 u64 start = 0;
2884 u64 end;
2885 u64 offset;
2886 unsigned long index;
2887
2888 while (1) {
2889 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2890 mark);
2891 if (ret)
2892 break;
2893
2894 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2895 while (start <= end) {
2896 index = start >> PAGE_CACHE_SHIFT;
2897 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2898 page = find_get_page(btree_inode->i_mapping, index);
2899 if (!page)
2900 continue;
2901 offset = page_offset(page);
2902
2903 spin_lock(&dirty_pages->buffer_lock);
2904 eb = radix_tree_lookup(
2905 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2906 offset >> PAGE_CACHE_SHIFT);
2907 spin_unlock(&dirty_pages->buffer_lock);
2908 if (eb) {
2909 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2910 &eb->bflags);
2911 atomic_set(&eb->refs, 1);
2912 }
2913 if (PageWriteback(page))
2914 end_page_writeback(page);
2915
2916 lock_page(page);
2917 if (PageDirty(page)) {
2918 clear_page_dirty_for_io(page);
2919 spin_lock_irq(&page->mapping->tree_lock);
2920 radix_tree_tag_clear(&page->mapping->page_tree,
2921 page_index(page),
2922 PAGECACHE_TAG_DIRTY);
2923 spin_unlock_irq(&page->mapping->tree_lock);
2924 }
2925
2926 page->mapping->a_ops->invalidatepage(page, 0);
2927 unlock_page(page);
2928 }
2929 }
2930
2931 return ret;
2932 }
2933
2934 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
2935 struct extent_io_tree *pinned_extents)
2936 {
2937 struct extent_io_tree *unpin;
2938 u64 start;
2939 u64 end;
2940 int ret;
2941
2942 unpin = pinned_extents;
2943 while (1) {
2944 ret = find_first_extent_bit(unpin, 0, &start, &end,
2945 EXTENT_DIRTY);
2946 if (ret)
2947 break;
2948
2949 /* opt_discard */
2950 ret = btrfs_error_discard_extent(root, start, end + 1 - start);
2951
2952 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2953 btrfs_error_unpin_extent_range(root, start, end);
2954 cond_resched();
2955 }
2956
2957 return 0;
2958 }
2959
2960 static int btrfs_cleanup_transaction(struct btrfs_root *root)
2961 {
2962 struct btrfs_transaction *t;
2963 LIST_HEAD(list);
2964
2965 WARN_ON(1);
2966
2967 mutex_lock(&root->fs_info->trans_mutex);
2968 mutex_lock(&root->fs_info->transaction_kthread_mutex);
2969
2970 list_splice_init(&root->fs_info->trans_list, &list);
2971 while (!list_empty(&list)) {
2972 t = list_entry(list.next, struct btrfs_transaction, list);
2973 if (!t)
2974 break;
2975
2976 btrfs_destroy_ordered_operations(root);
2977
2978 btrfs_destroy_ordered_extents(root);
2979
2980 btrfs_destroy_delayed_refs(t, root);
2981
2982 btrfs_block_rsv_release(root,
2983 &root->fs_info->trans_block_rsv,
2984 t->dirty_pages.dirty_bytes);
2985
2986 /* FIXME: cleanup wait for commit */
2987 t->in_commit = 1;
2988 t->blocked = 1;
2989 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
2990 wake_up(&root->fs_info->transaction_blocked_wait);
2991
2992 t->blocked = 0;
2993 if (waitqueue_active(&root->fs_info->transaction_wait))
2994 wake_up(&root->fs_info->transaction_wait);
2995 mutex_unlock(&root->fs_info->trans_mutex);
2996
2997 mutex_lock(&root->fs_info->trans_mutex);
2998 t->commit_done = 1;
2999 if (waitqueue_active(&t->commit_wait))
3000 wake_up(&t->commit_wait);
3001 mutex_unlock(&root->fs_info->trans_mutex);
3002
3003 mutex_lock(&root->fs_info->trans_mutex);
3004
3005 btrfs_destroy_pending_snapshots(t);
3006
3007 btrfs_destroy_delalloc_inodes(root);
3008
3009 spin_lock(&root->fs_info->new_trans_lock);
3010 root->fs_info->running_transaction = NULL;
3011 spin_unlock(&root->fs_info->new_trans_lock);
3012
3013 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3014 EXTENT_DIRTY);
3015
3016 btrfs_destroy_pinned_extent(root,
3017 root->fs_info->pinned_extents);
3018
3019 t->use_count = 0;
3020 list_del_init(&t->list);
3021 memset(t, 0, sizeof(*t));
3022 kmem_cache_free(btrfs_transaction_cachep, t);
3023 }
3024
3025 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3026 mutex_unlock(&root->fs_info->trans_mutex);
3027
3028 return 0;
3029 }
3030
3031 static struct extent_io_ops btree_extent_io_ops = {
3032 .write_cache_pages_lock_hook = btree_lock_page_hook,
3033 .readpage_end_io_hook = btree_readpage_end_io_hook,
3034 .submit_bio_hook = btree_submit_bio_hook,
3035 /* note we're sharing with inode.c for the merge bio hook */
3036 .merge_bio_hook = btrfs_merge_bio_hook,
3037 };
kernel source for telekom puls (alcatel/mediatek)