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Merge branch 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6/cjktty.git] / fs / btrfs / disk-io.c
blobb531c36455d86553de454b79e1cb9ab612c7d029
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 goto out;
364 if (!page->private)
365 goto out;
366 len = page->private >> 2;
367 WARN_ON(len == 0);
368
369 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
370 if (eb == NULL) {
371 WARN_ON(1);
372 goto out;
373 }
374 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
375 btrfs_header_generation(eb));
376 BUG_ON(ret);
377 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
378
379 found_start = btrfs_header_bytenr(eb);
380 if (found_start != start) {
381 WARN_ON(1);
382 goto err;
383 }
384 if (eb->first_page != page) {
385 WARN_ON(1);
386 goto err;
387 }
388 if (!PageUptodate(page)) {
389 WARN_ON(1);
390 goto err;
391 }
392 csum_tree_block(root, eb, 0);
393 err:
394 free_extent_buffer(eb);
395 out:
396 return 0;
397 }
398
399 static int check_tree_block_fsid(struct btrfs_root *root,
400 struct extent_buffer *eb)
401 {
402 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
403 u8 fsid[BTRFS_UUID_SIZE];
404 int ret = 1;
405
406 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
407 BTRFS_FSID_SIZE);
408 while (fs_devices) {
409 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
410 ret = 0;
411 break;
412 }
413 fs_devices = fs_devices->seed;
414 }
415 return ret;
416 }
417
418 #ifdef CONFIG_DEBUG_LOCK_ALLOC
419 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
420 {
421 lockdep_set_class_and_name(&eb->lock,
422 &btrfs_eb_class[level],
423 btrfs_eb_name[level]);
424 }
425 #endif
426
427 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
428 struct extent_state *state)
429 {
430 struct extent_io_tree *tree;
431 u64 found_start;
432 int found_level;
433 unsigned long len;
434 struct extent_buffer *eb;
435 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
436 int ret = 0;
437
438 tree = &BTRFS_I(page->mapping->host)->io_tree;
439 if (page->private == EXTENT_PAGE_PRIVATE)
440 goto out;
441 if (!page->private)
442 goto out;
443
444 len = page->private >> 2;
445 WARN_ON(len == 0);
446
447 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
448 if (eb == NULL) {
449 ret = -EIO;
450 goto out;
451 }
452
453 found_start = btrfs_header_bytenr(eb);
454 if (found_start != start) {
455 if (printk_ratelimit()) {
456 printk(KERN_INFO "btrfs bad tree block start "
457 "%llu %llu\n",
458 (unsigned long long)found_start,
459 (unsigned long long)eb->start);
460 }
461 ret = -EIO;
462 goto err;
463 }
464 if (eb->first_page != page) {
465 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
466 eb->first_page->index, page->index);
467 WARN_ON(1);
468 ret = -EIO;
469 goto err;
470 }
471 if (check_tree_block_fsid(root, eb)) {
472 if (printk_ratelimit()) {
473 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
474 (unsigned long long)eb->start);
475 }
476 ret = -EIO;
477 goto err;
478 }
479 found_level = btrfs_header_level(eb);
480
481 btrfs_set_buffer_lockdep_class(eb, found_level);
482
483 ret = csum_tree_block(root, eb, 1);
484 if (ret)
485 ret = -EIO;
486
487 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
488 end = eb->start + end - 1;
489 err:
490 free_extent_buffer(eb);
491 out:
492 return ret;
493 }
494
495 static void end_workqueue_bio(struct bio *bio, int err)
496 {
497 struct end_io_wq *end_io_wq = bio->bi_private;
498 struct btrfs_fs_info *fs_info;
499
500 fs_info = end_io_wq->info;
501 end_io_wq->error = err;
502 end_io_wq->work.func = end_workqueue_fn;
503 end_io_wq->work.flags = 0;
504
505 if (bio->bi_rw & REQ_WRITE) {
506 if (end_io_wq->metadata == 1)
507 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
508 &end_io_wq->work);
509 else if (end_io_wq->metadata == 2)
510 btrfs_queue_worker(&fs_info->endio_freespace_worker,
511 &end_io_wq->work);
512 else
513 btrfs_queue_worker(&fs_info->endio_write_workers,
514 &end_io_wq->work);
515 } else {
516 if (end_io_wq->metadata)
517 btrfs_queue_worker(&fs_info->endio_meta_workers,
518 &end_io_wq->work);
519 else
520 btrfs_queue_worker(&fs_info->endio_workers,
521 &end_io_wq->work);
522 }
523 }
524
525 /*
526 * For the metadata arg you want
527 *
528 * 0 - if data
529 * 1 - if normal metadta
530 * 2 - if writing to the free space cache area
531 */
532 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
533 int metadata)
534 {
535 struct end_io_wq *end_io_wq;
536 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
537 if (!end_io_wq)
538 return -ENOMEM;
539
540 end_io_wq->private = bio->bi_private;
541 end_io_wq->end_io = bio->bi_end_io;
542 end_io_wq->info = info;
543 end_io_wq->error = 0;
544 end_io_wq->bio = bio;
545 end_io_wq->metadata = metadata;
546
547 bio->bi_private = end_io_wq;
548 bio->bi_end_io = end_workqueue_bio;
549 return 0;
550 }
551
552 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
553 {
554 unsigned long limit = min_t(unsigned long,
555 info->workers.max_workers,
556 info->fs_devices->open_devices);
557 return 256 * limit;
558 }
559
560 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
561 {
562 return atomic_read(&info->nr_async_bios) >
563 btrfs_async_submit_limit(info);
564 }
565
566 static void run_one_async_start(struct btrfs_work *work)
567 {
568 struct async_submit_bio *async;
569
570 async = container_of(work, struct async_submit_bio, work);
571 async->submit_bio_start(async->inode, async->rw, async->bio,
572 async->mirror_num, async->bio_flags,
573 async->bio_offset);
574 }
575
576 static void run_one_async_done(struct btrfs_work *work)
577 {
578 struct btrfs_fs_info *fs_info;
579 struct async_submit_bio *async;
580 int limit;
581
582 async = container_of(work, struct async_submit_bio, work);
583 fs_info = BTRFS_I(async->inode)->root->fs_info;
584
585 limit = btrfs_async_submit_limit(fs_info);
586 limit = limit * 2 / 3;
587
588 atomic_dec(&fs_info->nr_async_submits);
589
590 if (atomic_read(&fs_info->nr_async_submits) < limit &&
591 waitqueue_active(&fs_info->async_submit_wait))
592 wake_up(&fs_info->async_submit_wait);
593
594 async->submit_bio_done(async->inode, async->rw, async->bio,
595 async->mirror_num, async->bio_flags,
596 async->bio_offset);
597 }
598
599 static void run_one_async_free(struct btrfs_work *work)
600 {
601 struct async_submit_bio *async;
602
603 async = container_of(work, struct async_submit_bio, work);
604 kfree(async);
605 }
606
607 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
608 int rw, struct bio *bio, int mirror_num,
609 unsigned long bio_flags,
610 u64 bio_offset,
611 extent_submit_bio_hook_t *submit_bio_start,
612 extent_submit_bio_hook_t *submit_bio_done)
613 {
614 struct async_submit_bio *async;
615
616 async = kmalloc(sizeof(*async), GFP_NOFS);
617 if (!async)
618 return -ENOMEM;
619
620 async->inode = inode;
621 async->rw = rw;
622 async->bio = bio;
623 async->mirror_num = mirror_num;
624 async->submit_bio_start = submit_bio_start;
625 async->submit_bio_done = submit_bio_done;
626
627 async->work.func = run_one_async_start;
628 async->work.ordered_func = run_one_async_done;
629 async->work.ordered_free = run_one_async_free;
630
631 async->work.flags = 0;
632 async->bio_flags = bio_flags;
633 async->bio_offset = bio_offset;
634
635 atomic_inc(&fs_info->nr_async_submits);
636
637 if (rw & REQ_SYNC)
638 btrfs_set_work_high_prio(&async->work);
639
640 btrfs_queue_worker(&fs_info->workers, &async->work);
641
642 while (atomic_read(&fs_info->async_submit_draining) &&
643 atomic_read(&fs_info->nr_async_submits)) {
644 wait_event(fs_info->async_submit_wait,
645 (atomic_read(&fs_info->nr_async_submits) == 0));
646 }
647
648 return 0;
649 }
650
651 static int btree_csum_one_bio(struct bio *bio)
652 {
653 struct bio_vec *bvec = bio->bi_io_vec;
654 int bio_index = 0;
655 struct btrfs_root *root;
656
657 WARN_ON(bio->bi_vcnt <= 0);
658 while (bio_index < bio->bi_vcnt) {
659 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
660 csum_dirty_buffer(root, bvec->bv_page);
661 bio_index++;
662 bvec++;
663 }
664 return 0;
665 }
666
667 static int __btree_submit_bio_start(struct inode *inode, int rw,
668 struct bio *bio, int mirror_num,
669 unsigned long bio_flags,
670 u64 bio_offset)
671 {
672 /*
673 * when we're called for a write, we're already in the async
674 * submission context. Just jump into btrfs_map_bio
675 */
676 btree_csum_one_bio(bio);
677 return 0;
678 }
679
680 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
681 int mirror_num, unsigned long bio_flags,
682 u64 bio_offset)
683 {
684 /*
685 * when we're called for a write, we're already in the async
686 * submission context. Just jump into btrfs_map_bio
687 */
688 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
689 }
690
691 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
692 int mirror_num, unsigned long bio_flags,
693 u64 bio_offset)
694 {
695 int ret;
696
697 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
698 bio, 1);
699 BUG_ON(ret);
700
701 if (!(rw & REQ_WRITE)) {
702 /*
703 * called for a read, do the setup so that checksum validation
704 * can happen in the async kernel threads
705 */
706 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
707 mirror_num, 0);
708 }
709
710 /*
711 * kthread helpers are used to submit writes so that checksumming
712 * can happen in parallel across all CPUs
713 */
714 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
715 inode, rw, bio, mirror_num, 0,
716 bio_offset,
717 __btree_submit_bio_start,
718 __btree_submit_bio_done);
719 }
720
721 #ifdef CONFIG_MIGRATION
722 static int btree_migratepage(struct address_space *mapping,
723 struct page *newpage, struct page *page)
724 {
725 /*
726 * we can't safely write a btree page from here,
727 * we haven't done the locking hook
728 */
729 if (PageDirty(page))
730 return -EAGAIN;
731 /*
732 * Buffers may be managed in a filesystem specific way.
733 * We must have no buffers or drop them.
734 */
735 if (page_has_private(page) &&
736 !try_to_release_page(page, GFP_KERNEL))
737 return -EAGAIN;
738 return migrate_page(mapping, newpage, page);
739 }
740 #endif
741
742 static int btree_writepage(struct page *page, struct writeback_control *wbc)
743 {
744 struct extent_io_tree *tree;
745 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
746 struct extent_buffer *eb;
747 int was_dirty;
748
749 tree = &BTRFS_I(page->mapping->host)->io_tree;
750 if (!(current->flags & PF_MEMALLOC)) {
751 return extent_write_full_page(tree, page,
752 btree_get_extent, wbc);
753 }
754
755 redirty_page_for_writepage(wbc, page);
756 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
757 WARN_ON(!eb);
758
759 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
760 if (!was_dirty) {
761 spin_lock(&root->fs_info->delalloc_lock);
762 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
763 spin_unlock(&root->fs_info->delalloc_lock);
764 }
765 free_extent_buffer(eb);
766
767 unlock_page(page);
768 return 0;
769 }
770
771 static int btree_writepages(struct address_space *mapping,
772 struct writeback_control *wbc)
773 {
774 struct extent_io_tree *tree;
775 tree = &BTRFS_I(mapping->host)->io_tree;
776 if (wbc->sync_mode == WB_SYNC_NONE) {
777 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
778 u64 num_dirty;
779 unsigned long thresh = 32 * 1024 * 1024;
780
781 if (wbc->for_kupdate)
782 return 0;
783
784 /* this is a bit racy, but that's ok */
785 num_dirty = root->fs_info->dirty_metadata_bytes;
786 if (num_dirty < thresh)
787 return 0;
788 }
789 return extent_writepages(tree, mapping, btree_get_extent, wbc);
790 }
791
792 static int btree_readpage(struct file *file, struct page *page)
793 {
794 struct extent_io_tree *tree;
795 tree = &BTRFS_I(page->mapping->host)->io_tree;
796 return extent_read_full_page(tree, page, btree_get_extent);
797 }
798
799 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
800 {
801 struct extent_io_tree *tree;
802 struct extent_map_tree *map;
803 int ret;
804
805 if (PageWriteback(page) || PageDirty(page))
806 return 0;
807
808 tree = &BTRFS_I(page->mapping->host)->io_tree;
809 map = &BTRFS_I(page->mapping->host)->extent_tree;
810
811 ret = try_release_extent_state(map, tree, page, gfp_flags);
812 if (!ret)
813 return 0;
814
815 ret = try_release_extent_buffer(tree, page);
816 if (ret == 1) {
817 ClearPagePrivate(page);
818 set_page_private(page, 0);
819 page_cache_release(page);
820 }
821
822 return ret;
823 }
824
825 static void btree_invalidatepage(struct page *page, unsigned long offset)
826 {
827 struct extent_io_tree *tree;
828 tree = &BTRFS_I(page->mapping->host)->io_tree;
829 extent_invalidatepage(tree, page, offset);
830 btree_releasepage(page, GFP_NOFS);
831 if (PagePrivate(page)) {
832 printk(KERN_WARNING "btrfs warning page private not zero "
833 "on page %llu\n", (unsigned long long)page_offset(page));
834 ClearPagePrivate(page);
835 set_page_private(page, 0);
836 page_cache_release(page);
837 }
838 }
839
840 static const struct address_space_operations btree_aops = {
841 .readpage = btree_readpage,
842 .writepage = btree_writepage,
843 .writepages = btree_writepages,
844 .releasepage = btree_releasepage,
845 .invalidatepage = btree_invalidatepage,
846 .sync_page = block_sync_page,
847 #ifdef CONFIG_MIGRATION
848 .migratepage = btree_migratepage,
849 #endif
850 };
851
852 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
853 u64 parent_transid)
854 {
855 struct extent_buffer *buf = NULL;
856 struct inode *btree_inode = root->fs_info->btree_inode;
857 int ret = 0;
858
859 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
860 if (!buf)
861 return 0;
862 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
863 buf, 0, 0, btree_get_extent, 0);
864 free_extent_buffer(buf);
865 return ret;
866 }
867
868 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
869 u64 bytenr, u32 blocksize)
870 {
871 struct inode *btree_inode = root->fs_info->btree_inode;
872 struct extent_buffer *eb;
873 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
874 bytenr, blocksize, GFP_NOFS);
875 return eb;
876 }
877
878 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
879 u64 bytenr, u32 blocksize)
880 {
881 struct inode *btree_inode = root->fs_info->btree_inode;
882 struct extent_buffer *eb;
883
884 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
885 bytenr, blocksize, NULL, GFP_NOFS);
886 return eb;
887 }
888
889
890 int btrfs_write_tree_block(struct extent_buffer *buf)
891 {
892 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
893 buf->start + buf->len - 1);
894 }
895
896 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
897 {
898 return filemap_fdatawait_range(buf->first_page->mapping,
899 buf->start, buf->start + buf->len - 1);
900 }
901
902 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
903 u32 blocksize, u64 parent_transid)
904 {
905 struct extent_buffer *buf = NULL;
906 int ret;
907
908 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
909 if (!buf)
910 return NULL;
911
912 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
913
914 if (ret == 0)
915 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
916 return buf;
917
918 }
919
920 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
921 struct extent_buffer *buf)
922 {
923 struct inode *btree_inode = root->fs_info->btree_inode;
924 if (btrfs_header_generation(buf) ==
925 root->fs_info->running_transaction->transid) {
926 btrfs_assert_tree_locked(buf);
927
928 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
929 spin_lock(&root->fs_info->delalloc_lock);
930 if (root->fs_info->dirty_metadata_bytes >= buf->len)
931 root->fs_info->dirty_metadata_bytes -= buf->len;
932 else
933 WARN_ON(1);
934 spin_unlock(&root->fs_info->delalloc_lock);
935 }
936
937 /* ugh, clear_extent_buffer_dirty needs to lock the page */
938 btrfs_set_lock_blocking(buf);
939 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
940 buf);
941 }
942 return 0;
943 }
944
945 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
946 u32 stripesize, struct btrfs_root *root,
947 struct btrfs_fs_info *fs_info,
948 u64 objectid)
949 {
950 root->node = NULL;
951 root->commit_root = NULL;
952 root->sectorsize = sectorsize;
953 root->nodesize = nodesize;
954 root->leafsize = leafsize;
955 root->stripesize = stripesize;
956 root->ref_cows = 0;
957 root->track_dirty = 0;
958 root->in_radix = 0;
959 root->orphan_item_inserted = 0;
960 root->orphan_cleanup_state = 0;
961
962 root->fs_info = fs_info;
963 root->objectid = objectid;
964 root->last_trans = 0;
965 root->highest_objectid = 0;
966 root->name = NULL;
967 root->in_sysfs = 0;
968 root->inode_tree = RB_ROOT;
969 root->block_rsv = NULL;
970 root->orphan_block_rsv = NULL;
971
972 INIT_LIST_HEAD(&root->dirty_list);
973 INIT_LIST_HEAD(&root->orphan_list);
974 INIT_LIST_HEAD(&root->root_list);
975 spin_lock_init(&root->node_lock);
976 spin_lock_init(&root->orphan_lock);
977 spin_lock_init(&root->inode_lock);
978 spin_lock_init(&root->accounting_lock);
979 mutex_init(&root->objectid_mutex);
980 mutex_init(&root->log_mutex);
981 init_waitqueue_head(&root->log_writer_wait);
982 init_waitqueue_head(&root->log_commit_wait[0]);
983 init_waitqueue_head(&root->log_commit_wait[1]);
984 atomic_set(&root->log_commit[0], 0);
985 atomic_set(&root->log_commit[1], 0);
986 atomic_set(&root->log_writers, 0);
987 root->log_batch = 0;
988 root->log_transid = 0;
989 root->last_log_commit = 0;
990 extent_io_tree_init(&root->dirty_log_pages,
991 fs_info->btree_inode->i_mapping, GFP_NOFS);
992
993 memset(&root->root_key, 0, sizeof(root->root_key));
994 memset(&root->root_item, 0, sizeof(root->root_item));
995 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
996 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
997 root->defrag_trans_start = fs_info->generation;
998 init_completion(&root->kobj_unregister);
999 root->defrag_running = 0;
1000 root->root_key.objectid = objectid;
1001 root->anon_super.s_root = NULL;
1002 root->anon_super.s_dev = 0;
1003 INIT_LIST_HEAD(&root->anon_super.s_list);
1004 INIT_LIST_HEAD(&root->anon_super.s_instances);
1005 init_rwsem(&root->anon_super.s_umount);
1006
1007 return 0;
1008 }
1009
1010 static int find_and_setup_root(struct btrfs_root *tree_root,
1011 struct btrfs_fs_info *fs_info,
1012 u64 objectid,
1013 struct btrfs_root *root)
1014 {
1015 int ret;
1016 u32 blocksize;
1017 u64 generation;
1018
1019 __setup_root(tree_root->nodesize, tree_root->leafsize,
1020 tree_root->sectorsize, tree_root->stripesize,
1021 root, fs_info, objectid);
1022 ret = btrfs_find_last_root(tree_root, objectid,
1023 &root->root_item, &root->root_key);
1024 if (ret > 0)
1025 return -ENOENT;
1026 BUG_ON(ret);
1027
1028 generation = btrfs_root_generation(&root->root_item);
1029 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1030 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1031 blocksize, generation);
1032 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1033 free_extent_buffer(root->node);
1034 return -EIO;
1035 }
1036 root->commit_root = btrfs_root_node(root);
1037 return 0;
1038 }
1039
1040 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1041 struct btrfs_fs_info *fs_info)
1042 {
1043 struct btrfs_root *root;
1044 struct btrfs_root *tree_root = fs_info->tree_root;
1045 struct extent_buffer *leaf;
1046
1047 root = kzalloc(sizeof(*root), GFP_NOFS);
1048 if (!root)
1049 return ERR_PTR(-ENOMEM);
1050
1051 __setup_root(tree_root->nodesize, tree_root->leafsize,
1052 tree_root->sectorsize, tree_root->stripesize,
1053 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1054
1055 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1056 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1057 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1058 /*
1059 * log trees do not get reference counted because they go away
1060 * before a real commit is actually done. They do store pointers
1061 * to file data extents, and those reference counts still get
1062 * updated (along with back refs to the log tree).
1063 */
1064 root->ref_cows = 0;
1065
1066 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1067 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1068 if (IS_ERR(leaf)) {
1069 kfree(root);
1070 return ERR_CAST(leaf);
1071 }
1072
1073 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1074 btrfs_set_header_bytenr(leaf, leaf->start);
1075 btrfs_set_header_generation(leaf, trans->transid);
1076 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1077 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1078 root->node = leaf;
1079
1080 write_extent_buffer(root->node, root->fs_info->fsid,
1081 (unsigned long)btrfs_header_fsid(root->node),
1082 BTRFS_FSID_SIZE);
1083 btrfs_mark_buffer_dirty(root->node);
1084 btrfs_tree_unlock(root->node);
1085 return root;
1086 }
1087
1088 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1089 struct btrfs_fs_info *fs_info)
1090 {
1091 struct btrfs_root *log_root;
1092
1093 log_root = alloc_log_tree(trans, fs_info);
1094 if (IS_ERR(log_root))
1095 return PTR_ERR(log_root);
1096 WARN_ON(fs_info->log_root_tree);
1097 fs_info->log_root_tree = log_root;
1098 return 0;
1099 }
1100
1101 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1102 struct btrfs_root *root)
1103 {
1104 struct btrfs_root *log_root;
1105 struct btrfs_inode_item *inode_item;
1106
1107 log_root = alloc_log_tree(trans, root->fs_info);
1108 if (IS_ERR(log_root))
1109 return PTR_ERR(log_root);
1110
1111 log_root->last_trans = trans->transid;
1112 log_root->root_key.offset = root->root_key.objectid;
1113
1114 inode_item = &log_root->root_item.inode;
1115 inode_item->generation = cpu_to_le64(1);
1116 inode_item->size = cpu_to_le64(3);
1117 inode_item->nlink = cpu_to_le32(1);
1118 inode_item->nbytes = cpu_to_le64(root->leafsize);
1119 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1120
1121 btrfs_set_root_node(&log_root->root_item, log_root->node);
1122
1123 WARN_ON(root->log_root);
1124 root->log_root = log_root;
1125 root->log_transid = 0;
1126 root->last_log_commit = 0;
1127 return 0;
1128 }
1129
1130 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1131 struct btrfs_key *location)
1132 {
1133 struct btrfs_root *root;
1134 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1135 struct btrfs_path *path;
1136 struct extent_buffer *l;
1137 u64 generation;
1138 u32 blocksize;
1139 int ret = 0;
1140
1141 root = kzalloc(sizeof(*root), GFP_NOFS);
1142 if (!root)
1143 return ERR_PTR(-ENOMEM);
1144 if (location->offset == (u64)-1) {
1145 ret = find_and_setup_root(tree_root, fs_info,
1146 location->objectid, root);
1147 if (ret) {
1148 kfree(root);
1149 return ERR_PTR(ret);
1150 }
1151 goto out;
1152 }
1153
1154 __setup_root(tree_root->nodesize, tree_root->leafsize,
1155 tree_root->sectorsize, tree_root->stripesize,
1156 root, fs_info, location->objectid);
1157
1158 path = btrfs_alloc_path();
1159 BUG_ON(!path);
1160 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1161 if (ret == 0) {
1162 l = path->nodes[0];
1163 read_extent_buffer(l, &root->root_item,
1164 btrfs_item_ptr_offset(l, path->slots[0]),
1165 sizeof(root->root_item));
1166 memcpy(&root->root_key, location, sizeof(*location));
1167 }
1168 btrfs_free_path(path);
1169 if (ret) {
1170 kfree(root);
1171 if (ret > 0)
1172 ret = -ENOENT;
1173 return ERR_PTR(ret);
1174 }
1175
1176 generation = btrfs_root_generation(&root->root_item);
1177 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1178 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1179 blocksize, generation);
1180 root->commit_root = btrfs_root_node(root);
1181 BUG_ON(!root->node);
1182 out:
1183 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1184 root->ref_cows = 1;
1185
1186 return root;
1187 }
1188
1189 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1190 u64 root_objectid)
1191 {
1192 struct btrfs_root *root;
1193
1194 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1195 return fs_info->tree_root;
1196 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1197 return fs_info->extent_root;
1198
1199 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1200 (unsigned long)root_objectid);
1201 return root;
1202 }
1203
1204 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1205 struct btrfs_key *location)
1206 {
1207 struct btrfs_root *root;
1208 int ret;
1209
1210 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1211 return fs_info->tree_root;
1212 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1213 return fs_info->extent_root;
1214 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1215 return fs_info->chunk_root;
1216 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1217 return fs_info->dev_root;
1218 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1219 return fs_info->csum_root;
1220 again:
1221 spin_lock(&fs_info->fs_roots_radix_lock);
1222 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1223 (unsigned long)location->objectid);
1224 spin_unlock(&fs_info->fs_roots_radix_lock);
1225 if (root)
1226 return root;
1227
1228 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1229 if (IS_ERR(root))
1230 return root;
1231
1232 set_anon_super(&root->anon_super, NULL);
1233
1234 if (btrfs_root_refs(&root->root_item) == 0) {
1235 ret = -ENOENT;
1236 goto fail;
1237 }
1238
1239 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1240 if (ret < 0)
1241 goto fail;
1242 if (ret == 0)
1243 root->orphan_item_inserted = 1;
1244
1245 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1246 if (ret)
1247 goto fail;
1248
1249 spin_lock(&fs_info->fs_roots_radix_lock);
1250 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1251 (unsigned long)root->root_key.objectid,
1252 root);
1253 if (ret == 0)
1254 root->in_radix = 1;
1255
1256 spin_unlock(&fs_info->fs_roots_radix_lock);
1257 radix_tree_preload_end();
1258 if (ret) {
1259 if (ret == -EEXIST) {
1260 free_fs_root(root);
1261 goto again;
1262 }
1263 goto fail;
1264 }
1265
1266 ret = btrfs_find_dead_roots(fs_info->tree_root,
1267 root->root_key.objectid);
1268 WARN_ON(ret);
1269 return root;
1270 fail:
1271 free_fs_root(root);
1272 return ERR_PTR(ret);
1273 }
1274
1275 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1276 struct btrfs_key *location,
1277 const char *name, int namelen)
1278 {
1279 return btrfs_read_fs_root_no_name(fs_info, location);
1280 #if 0
1281 struct btrfs_root *root;
1282 int ret;
1283
1284 root = btrfs_read_fs_root_no_name(fs_info, location);
1285 if (!root)
1286 return NULL;
1287
1288 if (root->in_sysfs)
1289 return root;
1290
1291 ret = btrfs_set_root_name(root, name, namelen);
1292 if (ret) {
1293 free_extent_buffer(root->node);
1294 kfree(root);
1295 return ERR_PTR(ret);
1296 }
1297
1298 ret = btrfs_sysfs_add_root(root);
1299 if (ret) {
1300 free_extent_buffer(root->node);
1301 kfree(root->name);
1302 kfree(root);
1303 return ERR_PTR(ret);
1304 }
1305 root->in_sysfs = 1;
1306 return root;
1307 #endif
1308 }
1309
1310 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1311 {
1312 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1313 int ret = 0;
1314 struct btrfs_device *device;
1315 struct backing_dev_info *bdi;
1316
1317 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1318 if (!device->bdev)
1319 continue;
1320 bdi = blk_get_backing_dev_info(device->bdev);
1321 if (bdi && bdi_congested(bdi, bdi_bits)) {
1322 ret = 1;
1323 break;
1324 }
1325 }
1326 return ret;
1327 }
1328
1329 /*
1330 * this unplugs every device on the box, and it is only used when page
1331 * is null
1332 */
1333 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1334 {
1335 struct btrfs_device *device;
1336 struct btrfs_fs_info *info;
1337
1338 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1339 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1340 if (!device->bdev)
1341 continue;
1342
1343 bdi = blk_get_backing_dev_info(device->bdev);
1344 if (bdi->unplug_io_fn)
1345 bdi->unplug_io_fn(bdi, page);
1346 }
1347 }
1348
1349 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1350 {
1351 struct inode *inode;
1352 struct extent_map_tree *em_tree;
1353 struct extent_map *em;
1354 struct address_space *mapping;
1355 u64 offset;
1356
1357 /* the generic O_DIRECT read code does this */
1358 if (1 || !page) {
1359 __unplug_io_fn(bdi, page);
1360 return;
1361 }
1362
1363 /*
1364 * page->mapping may change at any time. Get a consistent copy
1365 * and use that for everything below
1366 */
1367 smp_mb();
1368 mapping = page->mapping;
1369 if (!mapping)
1370 return;
1371
1372 inode = mapping->host;
1373
1374 /*
1375 * don't do the expensive searching for a small number of
1376 * devices
1377 */
1378 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1379 __unplug_io_fn(bdi, page);
1380 return;
1381 }
1382
1383 offset = page_offset(page);
1384
1385 em_tree = &BTRFS_I(inode)->extent_tree;
1386 read_lock(&em_tree->lock);
1387 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1388 read_unlock(&em_tree->lock);
1389 if (!em) {
1390 __unplug_io_fn(bdi, page);
1391 return;
1392 }
1393
1394 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1395 free_extent_map(em);
1396 __unplug_io_fn(bdi, page);
1397 return;
1398 }
1399 offset = offset - em->start;
1400 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1401 em->block_start + offset, page);
1402 free_extent_map(em);
1403 }
1404
1405 /*
1406 * If this fails, caller must call bdi_destroy() to get rid of the
1407 * bdi again.
1408 */
1409 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1410 {
1411 int err;
1412
1413 bdi->capabilities = BDI_CAP_MAP_COPY;
1414 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1415 if (err)
1416 return err;
1417
1418 bdi->ra_pages = default_backing_dev_info.ra_pages;
1419 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1420 bdi->unplug_io_data = info;
1421 bdi->congested_fn = btrfs_congested_fn;
1422 bdi->congested_data = info;
1423 return 0;
1424 }
1425
1426 static int bio_ready_for_csum(struct bio *bio)
1427 {
1428 u64 length = 0;
1429 u64 buf_len = 0;
1430 u64 start = 0;
1431 struct page *page;
1432 struct extent_io_tree *io_tree = NULL;
1433 struct bio_vec *bvec;
1434 int i;
1435 int ret;
1436
1437 bio_for_each_segment(bvec, bio, i) {
1438 page = bvec->bv_page;
1439 if (page->private == EXTENT_PAGE_PRIVATE) {
1440 length += bvec->bv_len;
1441 continue;
1442 }
1443 if (!page->private) {
1444 length += bvec->bv_len;
1445 continue;
1446 }
1447 length = bvec->bv_len;
1448 buf_len = page->private >> 2;
1449 start = page_offset(page) + bvec->bv_offset;
1450 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1451 }
1452 /* are we fully contained in this bio? */
1453 if (buf_len <= length)
1454 return 1;
1455
1456 ret = extent_range_uptodate(io_tree, start + length,
1457 start + buf_len - 1);
1458 return ret;
1459 }
1460
1461 /*
1462 * called by the kthread helper functions to finally call the bio end_io
1463 * functions. This is where read checksum verification actually happens
1464 */
1465 static void end_workqueue_fn(struct btrfs_work *work)
1466 {
1467 struct bio *bio;
1468 struct end_io_wq *end_io_wq;
1469 struct btrfs_fs_info *fs_info;
1470 int error;
1471
1472 end_io_wq = container_of(work, struct end_io_wq, work);
1473 bio = end_io_wq->bio;
1474 fs_info = end_io_wq->info;
1475
1476 /* metadata bio reads are special because the whole tree block must
1477 * be checksummed at once. This makes sure the entire block is in
1478 * ram and up to date before trying to verify things. For
1479 * blocksize <= pagesize, it is basically a noop
1480 */
1481 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1482 !bio_ready_for_csum(bio)) {
1483 btrfs_queue_worker(&fs_info->endio_meta_workers,
1484 &end_io_wq->work);
1485 return;
1486 }
1487 error = end_io_wq->error;
1488 bio->bi_private = end_io_wq->private;
1489 bio->bi_end_io = end_io_wq->end_io;
1490 kfree(end_io_wq);
1491 bio_endio(bio, error);
1492 }
1493
1494 static int cleaner_kthread(void *arg)
1495 {
1496 struct btrfs_root *root = arg;
1497
1498 do {
1499 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1500
1501 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1502 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1503 btrfs_run_delayed_iputs(root);
1504 btrfs_clean_old_snapshots(root);
1505 mutex_unlock(&root->fs_info->cleaner_mutex);
1506 }
1507
1508 if (freezing(current)) {
1509 refrigerator();
1510 } else {
1511 set_current_state(TASK_INTERRUPTIBLE);
1512 if (!kthread_should_stop())
1513 schedule();
1514 __set_current_state(TASK_RUNNING);
1515 }
1516 } while (!kthread_should_stop());
1517 return 0;
1518 }
1519
1520 static int transaction_kthread(void *arg)
1521 {
1522 struct btrfs_root *root = arg;
1523 struct btrfs_trans_handle *trans;
1524 struct btrfs_transaction *cur;
1525 u64 transid;
1526 unsigned long now;
1527 unsigned long delay;
1528 int ret;
1529
1530 do {
1531 delay = HZ * 30;
1532 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1533 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1534
1535 spin_lock(&root->fs_info->new_trans_lock);
1536 cur = root->fs_info->running_transaction;
1537 if (!cur) {
1538 spin_unlock(&root->fs_info->new_trans_lock);
1539 goto sleep;
1540 }
1541
1542 now = get_seconds();
1543 if (!cur->blocked &&
1544 (now < cur->start_time || now - cur->start_time < 30)) {
1545 spin_unlock(&root->fs_info->new_trans_lock);
1546 delay = HZ * 5;
1547 goto sleep;
1548 }
1549 transid = cur->transid;
1550 spin_unlock(&root->fs_info->new_trans_lock);
1551
1552 trans = btrfs_join_transaction(root, 1);
1553 if (transid == trans->transid) {
1554 ret = btrfs_commit_transaction(trans, root);
1555 BUG_ON(ret);
1556 } else {
1557 btrfs_end_transaction(trans, root);
1558 }
1559 sleep:
1560 wake_up_process(root->fs_info->cleaner_kthread);
1561 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1562
1563 if (freezing(current)) {
1564 refrigerator();
1565 } else {
1566 set_current_state(TASK_INTERRUPTIBLE);
1567 if (!kthread_should_stop() &&
1568 !btrfs_transaction_blocked(root->fs_info))
1569 schedule_timeout(delay);
1570 __set_current_state(TASK_RUNNING);
1571 }
1572 } while (!kthread_should_stop());
1573 return 0;
1574 }
1575
1576 struct btrfs_root *open_ctree(struct super_block *sb,
1577 struct btrfs_fs_devices *fs_devices,
1578 char *options)
1579 {
1580 u32 sectorsize;
1581 u32 nodesize;
1582 u32 leafsize;
1583 u32 blocksize;
1584 u32 stripesize;
1585 u64 generation;
1586 u64 features;
1587 struct btrfs_key location;
1588 struct buffer_head *bh;
1589 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1590 GFP_NOFS);
1591 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1592 GFP_NOFS);
1593 struct btrfs_root *tree_root = btrfs_sb(sb);
1594 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1595 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1596 GFP_NOFS);
1597 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1598 GFP_NOFS);
1599 struct btrfs_root *log_tree_root;
1600
1601 int ret;
1602 int err = -EINVAL;
1603
1604 struct btrfs_super_block *disk_super;
1605
1606 if (!extent_root || !tree_root || !fs_info ||
1607 !chunk_root || !dev_root || !csum_root) {
1608 err = -ENOMEM;
1609 goto fail;
1610 }
1611
1612 ret = init_srcu_struct(&fs_info->subvol_srcu);
1613 if (ret) {
1614 err = ret;
1615 goto fail;
1616 }
1617
1618 ret = setup_bdi(fs_info, &fs_info->bdi);
1619 if (ret) {
1620 err = ret;
1621 goto fail_srcu;
1622 }
1623
1624 fs_info->btree_inode = new_inode(sb);
1625 if (!fs_info->btree_inode) {
1626 err = -ENOMEM;
1627 goto fail_bdi;
1628 }
1629
1630 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1631 INIT_LIST_HEAD(&fs_info->trans_list);
1632 INIT_LIST_HEAD(&fs_info->dead_roots);
1633 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1634 INIT_LIST_HEAD(&fs_info->hashers);
1635 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1636 INIT_LIST_HEAD(&fs_info->ordered_operations);
1637 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1638 spin_lock_init(&fs_info->delalloc_lock);
1639 spin_lock_init(&fs_info->new_trans_lock);
1640 spin_lock_init(&fs_info->ref_cache_lock);
1641 spin_lock_init(&fs_info->fs_roots_radix_lock);
1642 spin_lock_init(&fs_info->delayed_iput_lock);
1643
1644 init_completion(&fs_info->kobj_unregister);
1645 fs_info->tree_root = tree_root;
1646 fs_info->extent_root = extent_root;
1647 fs_info->csum_root = csum_root;
1648 fs_info->chunk_root = chunk_root;
1649 fs_info->dev_root = dev_root;
1650 fs_info->fs_devices = fs_devices;
1651 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1652 INIT_LIST_HEAD(&fs_info->space_info);
1653 btrfs_mapping_init(&fs_info->mapping_tree);
1654 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1655 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1656 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1657 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1658 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1659 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1660 mutex_init(&fs_info->durable_block_rsv_mutex);
1661 atomic_set(&fs_info->nr_async_submits, 0);
1662 atomic_set(&fs_info->async_delalloc_pages, 0);
1663 atomic_set(&fs_info->async_submit_draining, 0);
1664 atomic_set(&fs_info->nr_async_bios, 0);
1665 fs_info->sb = sb;
1666 fs_info->max_inline = 8192 * 1024;
1667 fs_info->metadata_ratio = 0;
1668
1669 fs_info->thread_pool_size = min_t(unsigned long,
1670 num_online_cpus() + 2, 8);
1671
1672 INIT_LIST_HEAD(&fs_info->ordered_extents);
1673 spin_lock_init(&fs_info->ordered_extent_lock);
1674
1675 sb->s_blocksize = 4096;
1676 sb->s_blocksize_bits = blksize_bits(4096);
1677 sb->s_bdi = &fs_info->bdi;
1678
1679 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1680 fs_info->btree_inode->i_nlink = 1;
1681 /*
1682 * we set the i_size on the btree inode to the max possible int.
1683 * the real end of the address space is determined by all of
1684 * the devices in the system
1685 */
1686 fs_info->btree_inode->i_size = OFFSET_MAX;
1687 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1688 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1689
1690 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1691 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1692 fs_info->btree_inode->i_mapping,
1693 GFP_NOFS);
1694 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1695 GFP_NOFS);
1696
1697 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1698
1699 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1700 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1701 sizeof(struct btrfs_key));
1702 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1703 insert_inode_hash(fs_info->btree_inode);
1704
1705 spin_lock_init(&fs_info->block_group_cache_lock);
1706 fs_info->block_group_cache_tree = RB_ROOT;
1707
1708 extent_io_tree_init(&fs_info->freed_extents[0],
1709 fs_info->btree_inode->i_mapping, GFP_NOFS);
1710 extent_io_tree_init(&fs_info->freed_extents[1],
1711 fs_info->btree_inode->i_mapping, GFP_NOFS);
1712 fs_info->pinned_extents = &fs_info->freed_extents[0];
1713 fs_info->do_barriers = 1;
1714
1715
1716 mutex_init(&fs_info->trans_mutex);
1717 mutex_init(&fs_info->ordered_operations_mutex);
1718 mutex_init(&fs_info->tree_log_mutex);
1719 mutex_init(&fs_info->chunk_mutex);
1720 mutex_init(&fs_info->transaction_kthread_mutex);
1721 mutex_init(&fs_info->cleaner_mutex);
1722 mutex_init(&fs_info->volume_mutex);
1723 init_rwsem(&fs_info->extent_commit_sem);
1724 init_rwsem(&fs_info->cleanup_work_sem);
1725 init_rwsem(&fs_info->subvol_sem);
1726
1727 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1728 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1729
1730 init_waitqueue_head(&fs_info->transaction_throttle);
1731 init_waitqueue_head(&fs_info->transaction_wait);
1732 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1733 init_waitqueue_head(&fs_info->async_submit_wait);
1734
1735 __setup_root(4096, 4096, 4096, 4096, tree_root,
1736 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1737
1738 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1739 if (!bh) {
1740 err = -EINVAL;
1741 goto fail_iput;
1742 }
1743
1744 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1745 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1746 sizeof(fs_info->super_for_commit));
1747 brelse(bh);
1748
1749 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1750
1751 disk_super = &fs_info->super_copy;
1752 if (!btrfs_super_root(disk_super))
1753 goto fail_iput;
1754
1755 /* check FS state, whether FS is broken. */
1756 fs_info->fs_state |= btrfs_super_flags(disk_super);
1757
1758 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1759
1760 ret = btrfs_parse_options(tree_root, options);
1761 if (ret) {
1762 err = ret;
1763 goto fail_iput;
1764 }
1765
1766 features = btrfs_super_incompat_flags(disk_super) &
1767 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1768 if (features) {
1769 printk(KERN_ERR "BTRFS: couldn't mount because of "
1770 "unsupported optional features (%Lx).\n",
1771 (unsigned long long)features);
1772 err = -EINVAL;
1773 goto fail_iput;
1774 }
1775
1776 features = btrfs_super_incompat_flags(disk_super);
1777 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1778 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1779 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1780 btrfs_set_super_incompat_flags(disk_super, features);
1781
1782 features = btrfs_super_compat_ro_flags(disk_super) &
1783 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1784 if (!(sb->s_flags & MS_RDONLY) && features) {
1785 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1786 "unsupported option features (%Lx).\n",
1787 (unsigned long long)features);
1788 err = -EINVAL;
1789 goto fail_iput;
1790 }
1791
1792 btrfs_init_workers(&fs_info->generic_worker,
1793 "genwork", 1, NULL);
1794
1795 btrfs_init_workers(&fs_info->workers, "worker",
1796 fs_info->thread_pool_size,
1797 &fs_info->generic_worker);
1798
1799 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1800 fs_info->thread_pool_size,
1801 &fs_info->generic_worker);
1802
1803 btrfs_init_workers(&fs_info->submit_workers, "submit",
1804 min_t(u64, fs_devices->num_devices,
1805 fs_info->thread_pool_size),
1806 &fs_info->generic_worker);
1807
1808 /* a higher idle thresh on the submit workers makes it much more
1809 * likely that bios will be send down in a sane order to the
1810 * devices
1811 */
1812 fs_info->submit_workers.idle_thresh = 64;
1813
1814 fs_info->workers.idle_thresh = 16;
1815 fs_info->workers.ordered = 1;
1816
1817 fs_info->delalloc_workers.idle_thresh = 2;
1818 fs_info->delalloc_workers.ordered = 1;
1819
1820 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1821 &fs_info->generic_worker);
1822 btrfs_init_workers(&fs_info->endio_workers, "endio",
1823 fs_info->thread_pool_size,
1824 &fs_info->generic_worker);
1825 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1826 fs_info->thread_pool_size,
1827 &fs_info->generic_worker);
1828 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1829 "endio-meta-write", fs_info->thread_pool_size,
1830 &fs_info->generic_worker);
1831 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1832 fs_info->thread_pool_size,
1833 &fs_info->generic_worker);
1834 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1835 1, &fs_info->generic_worker);
1836
1837 /*
1838 * endios are largely parallel and should have a very
1839 * low idle thresh
1840 */
1841 fs_info->endio_workers.idle_thresh = 4;
1842 fs_info->endio_meta_workers.idle_thresh = 4;
1843
1844 fs_info->endio_write_workers.idle_thresh = 2;
1845 fs_info->endio_meta_write_workers.idle_thresh = 2;
1846
1847 btrfs_start_workers(&fs_info->workers, 1);
1848 btrfs_start_workers(&fs_info->generic_worker, 1);
1849 btrfs_start_workers(&fs_info->submit_workers, 1);
1850 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1851 btrfs_start_workers(&fs_info->fixup_workers, 1);
1852 btrfs_start_workers(&fs_info->endio_workers, 1);
1853 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1854 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1855 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1856 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1857
1858 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1859 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1860 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1861
1862 nodesize = btrfs_super_nodesize(disk_super);
1863 leafsize = btrfs_super_leafsize(disk_super);
1864 sectorsize = btrfs_super_sectorsize(disk_super);
1865 stripesize = btrfs_super_stripesize(disk_super);
1866 tree_root->nodesize = nodesize;
1867 tree_root->leafsize = leafsize;
1868 tree_root->sectorsize = sectorsize;
1869 tree_root->stripesize = stripesize;
1870
1871 sb->s_blocksize = sectorsize;
1872 sb->s_blocksize_bits = blksize_bits(sectorsize);
1873
1874 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1875 sizeof(disk_super->magic))) {
1876 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1877 goto fail_sb_buffer;
1878 }
1879
1880 mutex_lock(&fs_info->chunk_mutex);
1881 ret = btrfs_read_sys_array(tree_root);
1882 mutex_unlock(&fs_info->chunk_mutex);
1883 if (ret) {
1884 printk(KERN_WARNING "btrfs: failed to read the system "
1885 "array on %s\n", sb->s_id);
1886 goto fail_sb_buffer;
1887 }
1888
1889 blocksize = btrfs_level_size(tree_root,
1890 btrfs_super_chunk_root_level(disk_super));
1891 generation = btrfs_super_chunk_root_generation(disk_super);
1892
1893 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1894 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1895
1896 chunk_root->node = read_tree_block(chunk_root,
1897 btrfs_super_chunk_root(disk_super),
1898 blocksize, generation);
1899 BUG_ON(!chunk_root->node);
1900 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1901 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1902 sb->s_id);
1903 goto fail_chunk_root;
1904 }
1905 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1906 chunk_root->commit_root = btrfs_root_node(chunk_root);
1907
1908 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1909 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1910 BTRFS_UUID_SIZE);
1911
1912 mutex_lock(&fs_info->chunk_mutex);
1913 ret = btrfs_read_chunk_tree(chunk_root);
1914 mutex_unlock(&fs_info->chunk_mutex);
1915 if (ret) {
1916 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1917 sb->s_id);
1918 goto fail_chunk_root;
1919 }
1920
1921 btrfs_close_extra_devices(fs_devices);
1922
1923 blocksize = btrfs_level_size(tree_root,
1924 btrfs_super_root_level(disk_super));
1925 generation = btrfs_super_generation(disk_super);
1926
1927 tree_root->node = read_tree_block(tree_root,
1928 btrfs_super_root(disk_super),
1929 blocksize, generation);
1930 if (!tree_root->node)
1931 goto fail_chunk_root;
1932 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1933 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1934 sb->s_id);
1935 goto fail_tree_root;
1936 }
1937 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1938 tree_root->commit_root = btrfs_root_node(tree_root);
1939
1940 ret = find_and_setup_root(tree_root, fs_info,
1941 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1942 if (ret)
1943 goto fail_tree_root;
1944 extent_root->track_dirty = 1;
1945
1946 ret = find_and_setup_root(tree_root, fs_info,
1947 BTRFS_DEV_TREE_OBJECTID, dev_root);
1948 if (ret)
1949 goto fail_extent_root;
1950 dev_root->track_dirty = 1;
1951
1952 ret = find_and_setup_root(tree_root, fs_info,
1953 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1954 if (ret)
1955 goto fail_dev_root;
1956
1957 csum_root->track_dirty = 1;
1958
1959 fs_info->generation = generation;
1960 fs_info->last_trans_committed = generation;
1961 fs_info->data_alloc_profile = (u64)-1;
1962 fs_info->metadata_alloc_profile = (u64)-1;
1963 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1964
1965 ret = btrfs_read_block_groups(extent_root);
1966 if (ret) {
1967 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1968 goto fail_block_groups;
1969 }
1970
1971 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1972 "btrfs-cleaner");
1973 if (IS_ERR(fs_info->cleaner_kthread))
1974 goto fail_block_groups;
1975
1976 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1977 tree_root,
1978 "btrfs-transaction");
1979 if (IS_ERR(fs_info->transaction_kthread))
1980 goto fail_cleaner;
1981
1982 if (!btrfs_test_opt(tree_root, SSD) &&
1983 !btrfs_test_opt(tree_root, NOSSD) &&
1984 !fs_info->fs_devices->rotating) {
1985 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1986 "mode\n");
1987 btrfs_set_opt(fs_info->mount_opt, SSD);
1988 }
1989
1990 /* do not make disk changes in broken FS */
1991 if (btrfs_super_log_root(disk_super) != 0 &&
1992 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
1993 u64 bytenr = btrfs_super_log_root(disk_super);
1994
1995 if (fs_devices->rw_devices == 0) {
1996 printk(KERN_WARNING "Btrfs log replay required "
1997 "on RO media\n");
1998 err = -EIO;
1999 goto fail_trans_kthread;
2000 }
2001 blocksize =
2002 btrfs_level_size(tree_root,
2003 btrfs_super_log_root_level(disk_super));
2004
2005 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2006 if (!log_tree_root) {
2007 err = -ENOMEM;
2008 goto fail_trans_kthread;
2009 }
2010
2011 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2012 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2013
2014 log_tree_root->node = read_tree_block(tree_root, bytenr,
2015 blocksize,
2016 generation + 1);
2017 ret = btrfs_recover_log_trees(log_tree_root);
2018 BUG_ON(ret);
2019
2020 if (sb->s_flags & MS_RDONLY) {
2021 ret = btrfs_commit_super(tree_root);
2022 BUG_ON(ret);
2023 }
2024 }
2025
2026 ret = btrfs_find_orphan_roots(tree_root);
2027 BUG_ON(ret);
2028
2029 if (!(sb->s_flags & MS_RDONLY)) {
2030 ret = btrfs_cleanup_fs_roots(fs_info);
2031 BUG_ON(ret);
2032
2033 ret = btrfs_recover_relocation(tree_root);
2034 if (ret < 0) {
2035 printk(KERN_WARNING
2036 "btrfs: failed to recover relocation\n");
2037 err = -EINVAL;
2038 goto fail_trans_kthread;
2039 }
2040 }
2041
2042 location.objectid = BTRFS_FS_TREE_OBJECTID;
2043 location.type = BTRFS_ROOT_ITEM_KEY;
2044 location.offset = (u64)-1;
2045
2046 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2047 if (!fs_info->fs_root)
2048 goto fail_trans_kthread;
2049 if (IS_ERR(fs_info->fs_root)) {
2050 err = PTR_ERR(fs_info->fs_root);
2051 goto fail_trans_kthread;
2052 }
2053
2054 if (!(sb->s_flags & MS_RDONLY)) {
2055 down_read(&fs_info->cleanup_work_sem);
2056 btrfs_orphan_cleanup(fs_info->fs_root);
2057 btrfs_orphan_cleanup(fs_info->tree_root);
2058 up_read(&fs_info->cleanup_work_sem);
2059 }
2060
2061 return tree_root;
2062
2063 fail_trans_kthread:
2064 kthread_stop(fs_info->transaction_kthread);
2065 fail_cleaner:
2066 kthread_stop(fs_info->cleaner_kthread);
2067
2068 /*
2069 * make sure we're done with the btree inode before we stop our
2070 * kthreads
2071 */
2072 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2073 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2074
2075 fail_block_groups:
2076 btrfs_free_block_groups(fs_info);
2077 free_extent_buffer(csum_root->node);
2078 free_extent_buffer(csum_root->commit_root);
2079 fail_dev_root:
2080 free_extent_buffer(dev_root->node);
2081 free_extent_buffer(dev_root->commit_root);
2082 fail_extent_root:
2083 free_extent_buffer(extent_root->node);
2084 free_extent_buffer(extent_root->commit_root);
2085 fail_tree_root:
2086 free_extent_buffer(tree_root->node);
2087 free_extent_buffer(tree_root->commit_root);
2088 fail_chunk_root:
2089 free_extent_buffer(chunk_root->node);
2090 free_extent_buffer(chunk_root->commit_root);
2091 fail_sb_buffer:
2092 btrfs_stop_workers(&fs_info->generic_worker);
2093 btrfs_stop_workers(&fs_info->fixup_workers);
2094 btrfs_stop_workers(&fs_info->delalloc_workers);
2095 btrfs_stop_workers(&fs_info->workers);
2096 btrfs_stop_workers(&fs_info->endio_workers);
2097 btrfs_stop_workers(&fs_info->endio_meta_workers);
2098 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2099 btrfs_stop_workers(&fs_info->endio_write_workers);
2100 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2101 btrfs_stop_workers(&fs_info->submit_workers);
2102 fail_iput:
2103 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2104 iput(fs_info->btree_inode);
2105
2106 btrfs_close_devices(fs_info->fs_devices);
2107 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2108 fail_bdi:
2109 bdi_destroy(&fs_info->bdi);
2110 fail_srcu:
2111 cleanup_srcu_struct(&fs_info->subvol_srcu);
2112 fail:
2113 kfree(extent_root);
2114 kfree(tree_root);
2115 kfree(fs_info);
2116 kfree(chunk_root);
2117 kfree(dev_root);
2118 kfree(csum_root);
2119 return ERR_PTR(err);
2120 }
2121
2122 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2123 {
2124 char b[BDEVNAME_SIZE];
2125
2126 if (uptodate) {
2127 set_buffer_uptodate(bh);
2128 } else {
2129 if (printk_ratelimit()) {
2130 printk(KERN_WARNING "lost page write due to "
2131 "I/O error on %s\n",
2132 bdevname(bh->b_bdev, b));
2133 }
2134 /* note, we dont' set_buffer_write_io_error because we have
2135 * our own ways of dealing with the IO errors
2136 */
2137 clear_buffer_uptodate(bh);
2138 }
2139 unlock_buffer(bh);
2140 put_bh(bh);
2141 }
2142
2143 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2144 {
2145 struct buffer_head *bh;
2146 struct buffer_head *latest = NULL;
2147 struct btrfs_super_block *super;
2148 int i;
2149 u64 transid = 0;
2150 u64 bytenr;
2151
2152 /* we would like to check all the supers, but that would make
2153 * a btrfs mount succeed after a mkfs from a different FS.
2154 * So, we need to add a special mount option to scan for
2155 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2156 */
2157 for (i = 0; i < 1; i++) {
2158 bytenr = btrfs_sb_offset(i);
2159 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2160 break;
2161 bh = __bread(bdev, bytenr / 4096, 4096);
2162 if (!bh)
2163 continue;
2164
2165 super = (struct btrfs_super_block *)bh->b_data;
2166 if (btrfs_super_bytenr(super) != bytenr ||
2167 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2168 sizeof(super->magic))) {
2169 brelse(bh);
2170 continue;
2171 }
2172
2173 if (!latest || btrfs_super_generation(super) > transid) {
2174 brelse(latest);
2175 latest = bh;
2176 transid = btrfs_super_generation(super);
2177 } else {
2178 brelse(bh);
2179 }
2180 }
2181 return latest;
2182 }
2183
2184 /*
2185 * this should be called twice, once with wait == 0 and
2186 * once with wait == 1. When wait == 0 is done, all the buffer heads
2187 * we write are pinned.
2188 *
2189 * They are released when wait == 1 is done.
2190 * max_mirrors must be the same for both runs, and it indicates how
2191 * many supers on this one device should be written.
2192 *
2193 * max_mirrors == 0 means to write them all.
2194 */
2195 static int write_dev_supers(struct btrfs_device *device,
2196 struct btrfs_super_block *sb,
2197 int do_barriers, int wait, int max_mirrors)
2198 {
2199 struct buffer_head *bh;
2200 int i;
2201 int ret;
2202 int errors = 0;
2203 u32 crc;
2204 u64 bytenr;
2205 int last_barrier = 0;
2206
2207 if (max_mirrors == 0)
2208 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2209
2210 /* make sure only the last submit_bh does a barrier */
2211 if (do_barriers) {
2212 for (i = 0; i < max_mirrors; i++) {
2213 bytenr = btrfs_sb_offset(i);
2214 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2215 device->total_bytes)
2216 break;
2217 last_barrier = i;
2218 }
2219 }
2220
2221 for (i = 0; i < max_mirrors; i++) {
2222 bytenr = btrfs_sb_offset(i);
2223 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2224 break;
2225
2226 if (wait) {
2227 bh = __find_get_block(device->bdev, bytenr / 4096,
2228 BTRFS_SUPER_INFO_SIZE);
2229 BUG_ON(!bh);
2230 wait_on_buffer(bh);
2231 if (!buffer_uptodate(bh))
2232 errors++;
2233
2234 /* drop our reference */
2235 brelse(bh);
2236
2237 /* drop the reference from the wait == 0 run */
2238 brelse(bh);
2239 continue;
2240 } else {
2241 btrfs_set_super_bytenr(sb, bytenr);
2242
2243 crc = ~(u32)0;
2244 crc = btrfs_csum_data(NULL, (char *)sb +
2245 BTRFS_CSUM_SIZE, crc,
2246 BTRFS_SUPER_INFO_SIZE -
2247 BTRFS_CSUM_SIZE);
2248 btrfs_csum_final(crc, sb->csum);
2249
2250 /*
2251 * one reference for us, and we leave it for the
2252 * caller
2253 */
2254 bh = __getblk(device->bdev, bytenr / 4096,
2255 BTRFS_SUPER_INFO_SIZE);
2256 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2257
2258 /* one reference for submit_bh */
2259 get_bh(bh);
2260
2261 set_buffer_uptodate(bh);
2262 lock_buffer(bh);
2263 bh->b_end_io = btrfs_end_buffer_write_sync;
2264 }
2265
2266 if (i == last_barrier && do_barriers)
2267 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2268 else
2269 ret = submit_bh(WRITE_SYNC, bh);
2270
2271 if (ret)
2272 errors++;
2273 }
2274 return errors < i ? 0 : -1;
2275 }
2276
2277 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2278 {
2279 struct list_head *head;
2280 struct btrfs_device *dev;
2281 struct btrfs_super_block *sb;
2282 struct btrfs_dev_item *dev_item;
2283 int ret;
2284 int do_barriers;
2285 int max_errors;
2286 int total_errors = 0;
2287 u64 flags;
2288
2289 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2290 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2291
2292 sb = &root->fs_info->super_for_commit;
2293 dev_item = &sb->dev_item;
2294
2295 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2296 head = &root->fs_info->fs_devices->devices;
2297 list_for_each_entry(dev, head, dev_list) {
2298 if (!dev->bdev) {
2299 total_errors++;
2300 continue;
2301 }
2302 if (!dev->in_fs_metadata || !dev->writeable)
2303 continue;
2304
2305 btrfs_set_stack_device_generation(dev_item, 0);
2306 btrfs_set_stack_device_type(dev_item, dev->type);
2307 btrfs_set_stack_device_id(dev_item, dev->devid);
2308 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2309 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2310 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2311 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2312 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2313 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2314 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2315
2316 flags = btrfs_super_flags(sb);
2317 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2318
2319 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2320 if (ret)
2321 total_errors++;
2322 }
2323 if (total_errors > max_errors) {
2324 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2325 total_errors);
2326 BUG();
2327 }
2328
2329 total_errors = 0;
2330 list_for_each_entry(dev, head, dev_list) {
2331 if (!dev->bdev)
2332 continue;
2333 if (!dev->in_fs_metadata || !dev->writeable)
2334 continue;
2335
2336 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2337 if (ret)
2338 total_errors++;
2339 }
2340 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2341 if (total_errors > max_errors) {
2342 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2343 total_errors);
2344 BUG();
2345 }
2346 return 0;
2347 }
2348
2349 int write_ctree_super(struct btrfs_trans_handle *trans,
2350 struct btrfs_root *root, int max_mirrors)
2351 {
2352 int ret;
2353
2354 ret = write_all_supers(root, max_mirrors);
2355 return ret;
2356 }
2357
2358 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2359 {
2360 spin_lock(&fs_info->fs_roots_radix_lock);
2361 radix_tree_delete(&fs_info->fs_roots_radix,
2362 (unsigned long)root->root_key.objectid);
2363 spin_unlock(&fs_info->fs_roots_radix_lock);
2364
2365 if (btrfs_root_refs(&root->root_item) == 0)
2366 synchronize_srcu(&fs_info->subvol_srcu);
2367
2368 free_fs_root(root);
2369 return 0;
2370 }
2371
2372 static void free_fs_root(struct btrfs_root *root)
2373 {
2374 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2375 if (root->anon_super.s_dev) {
2376 down_write(&root->anon_super.s_umount);
2377 kill_anon_super(&root->anon_super);
2378 }
2379 free_extent_buffer(root->node);
2380 free_extent_buffer(root->commit_root);
2381 kfree(root->name);
2382 kfree(root);
2383 }
2384
2385 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2386 {
2387 int ret;
2388 struct btrfs_root *gang[8];
2389 int i;
2390
2391 while (!list_empty(&fs_info->dead_roots)) {
2392 gang[0] = list_entry(fs_info->dead_roots.next,
2393 struct btrfs_root, root_list);
2394 list_del(&gang[0]->root_list);
2395
2396 if (gang[0]->in_radix) {
2397 btrfs_free_fs_root(fs_info, gang[0]);
2398 } else {
2399 free_extent_buffer(gang[0]->node);
2400 free_extent_buffer(gang[0]->commit_root);
2401 kfree(gang[0]);
2402 }
2403 }
2404
2405 while (1) {
2406 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2407 (void **)gang, 0,
2408 ARRAY_SIZE(gang));
2409 if (!ret)
2410 break;
2411 for (i = 0; i < ret; i++)
2412 btrfs_free_fs_root(fs_info, gang[i]);
2413 }
2414 return 0;
2415 }
2416
2417 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2418 {
2419 u64 root_objectid = 0;
2420 struct btrfs_root *gang[8];
2421 int i;
2422 int ret;
2423
2424 while (1) {
2425 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2426 (void **)gang, root_objectid,
2427 ARRAY_SIZE(gang));
2428 if (!ret)
2429 break;
2430
2431 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2432 for (i = 0; i < ret; i++) {
2433 root_objectid = gang[i]->root_key.objectid;
2434 btrfs_orphan_cleanup(gang[i]);
2435 }
2436 root_objectid++;
2437 }
2438 return 0;
2439 }
2440
2441 int btrfs_commit_super(struct btrfs_root *root)
2442 {
2443 struct btrfs_trans_handle *trans;
2444 int ret;
2445
2446 mutex_lock(&root->fs_info->cleaner_mutex);
2447 btrfs_run_delayed_iputs(root);
2448 btrfs_clean_old_snapshots(root);
2449 mutex_unlock(&root->fs_info->cleaner_mutex);
2450
2451 /* wait until ongoing cleanup work done */
2452 down_write(&root->fs_info->cleanup_work_sem);
2453 up_write(&root->fs_info->cleanup_work_sem);
2454
2455 trans = btrfs_join_transaction(root, 1);
2456 ret = btrfs_commit_transaction(trans, root);
2457 BUG_ON(ret);
2458 /* run commit again to drop the original snapshot */
2459 trans = btrfs_join_transaction(root, 1);
2460 btrfs_commit_transaction(trans, root);
2461 ret = btrfs_write_and_wait_transaction(NULL, root);
2462 BUG_ON(ret);
2463
2464 ret = write_ctree_super(NULL, root, 0);
2465 return ret;
2466 }
2467
2468 int close_ctree(struct btrfs_root *root)
2469 {
2470 struct btrfs_fs_info *fs_info = root->fs_info;
2471 int ret;
2472
2473 fs_info->closing = 1;
2474 smp_mb();
2475
2476 btrfs_put_block_group_cache(fs_info);
2477
2478 /*
2479 * Here come 2 situations when btrfs is broken to flip readonly:
2480 *
2481 * 1. when btrfs flips readonly somewhere else before
2482 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2483 * and btrfs will skip to write sb directly to keep
2484 * ERROR state on disk.
2485 *
2486 * 2. when btrfs flips readonly just in btrfs_commit_super,
2487 * and in such case, btrfs cannnot write sb via btrfs_commit_super,
2488 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2489 * btrfs will cleanup all FS resources first and write sb then.
2490 */
2491 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2492 ret = btrfs_commit_super(root);
2493 if (ret)
2494 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2495 }
2496
2497 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2498 ret = btrfs_error_commit_super(root);
2499 if (ret)
2500 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2501 }
2502
2503 kthread_stop(root->fs_info->transaction_kthread);
2504 kthread_stop(root->fs_info->cleaner_kthread);
2505
2506 fs_info->closing = 2;
2507 smp_mb();
2508
2509 if (fs_info->delalloc_bytes) {
2510 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2511 (unsigned long long)fs_info->delalloc_bytes);
2512 }
2513 if (fs_info->total_ref_cache_size) {
2514 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2515 (unsigned long long)fs_info->total_ref_cache_size);
2516 }
2517
2518 free_extent_buffer(fs_info->extent_root->node);
2519 free_extent_buffer(fs_info->extent_root->commit_root);
2520 free_extent_buffer(fs_info->tree_root->node);
2521 free_extent_buffer(fs_info->tree_root->commit_root);
2522 free_extent_buffer(root->fs_info->chunk_root->node);
2523 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2524 free_extent_buffer(root->fs_info->dev_root->node);
2525 free_extent_buffer(root->fs_info->dev_root->commit_root);
2526 free_extent_buffer(root->fs_info->csum_root->node);
2527 free_extent_buffer(root->fs_info->csum_root->commit_root);
2528
2529 btrfs_free_block_groups(root->fs_info);
2530
2531 del_fs_roots(fs_info);
2532
2533 iput(fs_info->btree_inode);
2534
2535 btrfs_stop_workers(&fs_info->generic_worker);
2536 btrfs_stop_workers(&fs_info->fixup_workers);
2537 btrfs_stop_workers(&fs_info->delalloc_workers);
2538 btrfs_stop_workers(&fs_info->workers);
2539 btrfs_stop_workers(&fs_info->endio_workers);
2540 btrfs_stop_workers(&fs_info->endio_meta_workers);
2541 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2542 btrfs_stop_workers(&fs_info->endio_write_workers);
2543 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2544 btrfs_stop_workers(&fs_info->submit_workers);
2545
2546 btrfs_close_devices(fs_info->fs_devices);
2547 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2548
2549 bdi_destroy(&fs_info->bdi);
2550 cleanup_srcu_struct(&fs_info->subvol_srcu);
2551
2552 kfree(fs_info->extent_root);
2553 kfree(fs_info->tree_root);
2554 kfree(fs_info->chunk_root);
2555 kfree(fs_info->dev_root);
2556 kfree(fs_info->csum_root);
2557 return 0;
2558 }
2559
2560 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2561 {
2562 int ret;
2563 struct inode *btree_inode = buf->first_page->mapping->host;
2564
2565 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2566 NULL);
2567 if (!ret)
2568 return ret;
2569
2570 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2571 parent_transid);
2572 return !ret;
2573 }
2574
2575 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2576 {
2577 struct inode *btree_inode = buf->first_page->mapping->host;
2578 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2579 buf);
2580 }
2581
2582 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2583 {
2584 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2585 u64 transid = btrfs_header_generation(buf);
2586 struct inode *btree_inode = root->fs_info->btree_inode;
2587 int was_dirty;
2588
2589 btrfs_assert_tree_locked(buf);
2590 if (transid != root->fs_info->generation) {
2591 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2592 "found %llu running %llu\n",
2593 (unsigned long long)buf->start,
2594 (unsigned long long)transid,
2595 (unsigned long long)root->fs_info->generation);
2596 WARN_ON(1);
2597 }
2598 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2599 buf);
2600 if (!was_dirty) {
2601 spin_lock(&root->fs_info->delalloc_lock);
2602 root->fs_info->dirty_metadata_bytes += buf->len;
2603 spin_unlock(&root->fs_info->delalloc_lock);
2604 }
2605 }
2606
2607 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2608 {
2609 /*
2610 * looks as though older kernels can get into trouble with
2611 * this code, they end up stuck in balance_dirty_pages forever
2612 */
2613 u64 num_dirty;
2614 unsigned long thresh = 32 * 1024 * 1024;
2615
2616 if (current->flags & PF_MEMALLOC)
2617 return;
2618
2619 num_dirty = root->fs_info->dirty_metadata_bytes;
2620
2621 if (num_dirty > thresh) {
2622 balance_dirty_pages_ratelimited_nr(
2623 root->fs_info->btree_inode->i_mapping, 1);
2624 }
2625 return;
2626 }
2627
2628 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2629 {
2630 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2631 int ret;
2632 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2633 if (ret == 0)
2634 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2635 return ret;
2636 }
2637
2638 int btree_lock_page_hook(struct page *page)
2639 {
2640 struct inode *inode = page->mapping->host;
2641 struct btrfs_root *root = BTRFS_I(inode)->root;
2642 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2643 struct extent_buffer *eb;
2644 unsigned long len;
2645 u64 bytenr = page_offset(page);
2646
2647 if (page->private == EXTENT_PAGE_PRIVATE)
2648 goto out;
2649
2650 len = page->private >> 2;
2651 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2652 if (!eb)
2653 goto out;
2654
2655 btrfs_tree_lock(eb);
2656 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2657
2658 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2659 spin_lock(&root->fs_info->delalloc_lock);
2660 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2661 root->fs_info->dirty_metadata_bytes -= eb->len;
2662 else
2663 WARN_ON(1);
2664 spin_unlock(&root->fs_info->delalloc_lock);
2665 }
2666
2667 btrfs_tree_unlock(eb);
2668 free_extent_buffer(eb);
2669 out:
2670 lock_page(page);
2671 return 0;
2672 }
2673
2674 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2675 int read_only)
2676 {
2677 if (read_only)
2678 return;
2679
2680 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2681 printk(KERN_WARNING "warning: mount fs with errors, "
2682 "running btrfsck is recommended\n");
2683 }
2684
2685 int btrfs_error_commit_super(struct btrfs_root *root)
2686 {
2687 int ret;
2688
2689 mutex_lock(&root->fs_info->cleaner_mutex);
2690 btrfs_run_delayed_iputs(root);
2691 mutex_unlock(&root->fs_info->cleaner_mutex);
2692
2693 down_write(&root->fs_info->cleanup_work_sem);
2694 up_write(&root->fs_info->cleanup_work_sem);
2695
2696 /* cleanup FS via transaction */
2697 btrfs_cleanup_transaction(root);
2698
2699 ret = write_ctree_super(NULL, root, 0);
2700
2701 return ret;
2702 }
2703
2704 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2705 {
2706 struct btrfs_inode *btrfs_inode;
2707 struct list_head splice;
2708
2709 INIT_LIST_HEAD(&splice);
2710
2711 mutex_lock(&root->fs_info->ordered_operations_mutex);
2712 spin_lock(&root->fs_info->ordered_extent_lock);
2713
2714 list_splice_init(&root->fs_info->ordered_operations, &splice);
2715 while (!list_empty(&splice)) {
2716 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2717 ordered_operations);
2718
2719 list_del_init(&btrfs_inode->ordered_operations);
2720
2721 btrfs_invalidate_inodes(btrfs_inode->root);
2722 }
2723
2724 spin_unlock(&root->fs_info->ordered_extent_lock);
2725 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2726
2727 return 0;
2728 }
2729
2730 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2731 {
2732 struct list_head splice;
2733 struct btrfs_ordered_extent *ordered;
2734 struct inode *inode;
2735
2736 INIT_LIST_HEAD(&splice);
2737
2738 spin_lock(&root->fs_info->ordered_extent_lock);
2739
2740 list_splice_init(&root->fs_info->ordered_extents, &splice);
2741 while (!list_empty(&splice)) {
2742 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2743 root_extent_list);
2744
2745 list_del_init(&ordered->root_extent_list);
2746 atomic_inc(&ordered->refs);
2747
2748 /* the inode may be getting freed (in sys_unlink path). */
2749 inode = igrab(ordered->inode);
2750
2751 spin_unlock(&root->fs_info->ordered_extent_lock);
2752 if (inode)
2753 iput(inode);
2754
2755 atomic_set(&ordered->refs, 1);
2756 btrfs_put_ordered_extent(ordered);
2757
2758 spin_lock(&root->fs_info->ordered_extent_lock);
2759 }
2760
2761 spin_unlock(&root->fs_info->ordered_extent_lock);
2762
2763 return 0;
2764 }
2765
2766 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2767 struct btrfs_root *root)
2768 {
2769 struct rb_node *node;
2770 struct btrfs_delayed_ref_root *delayed_refs;
2771 struct btrfs_delayed_ref_node *ref;
2772 int ret = 0;
2773
2774 delayed_refs = &trans->delayed_refs;
2775
2776 spin_lock(&delayed_refs->lock);
2777 if (delayed_refs->num_entries == 0) {
2778 printk(KERN_INFO "delayed_refs has NO entry\n");
2779 return ret;
2780 }
2781
2782 node = rb_first(&delayed_refs->root);
2783 while (node) {
2784 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2785 node = rb_next(node);
2786
2787 ref->in_tree = 0;
2788 rb_erase(&ref->rb_node, &delayed_refs->root);
2789 delayed_refs->num_entries--;
2790
2791 atomic_set(&ref->refs, 1);
2792 if (btrfs_delayed_ref_is_head(ref)) {
2793 struct btrfs_delayed_ref_head *head;
2794
2795 head = btrfs_delayed_node_to_head(ref);
2796 mutex_lock(&head->mutex);
2797 kfree(head->extent_op);
2798 delayed_refs->num_heads--;
2799 if (list_empty(&head->cluster))
2800 delayed_refs->num_heads_ready--;
2801 list_del_init(&head->cluster);
2802 mutex_unlock(&head->mutex);
2803 }
2804
2805 spin_unlock(&delayed_refs->lock);
2806 btrfs_put_delayed_ref(ref);
2807
2808 cond_resched();
2809 spin_lock(&delayed_refs->lock);
2810 }
2811
2812 spin_unlock(&delayed_refs->lock);
2813
2814 return ret;
2815 }
2816
2817 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2818 {
2819 struct btrfs_pending_snapshot *snapshot;
2820 struct list_head splice;
2821
2822 INIT_LIST_HEAD(&splice);
2823
2824 list_splice_init(&t->pending_snapshots, &splice);
2825
2826 while (!list_empty(&splice)) {
2827 snapshot = list_entry(splice.next,
2828 struct btrfs_pending_snapshot,
2829 list);
2830
2831 list_del_init(&snapshot->list);
2832
2833 kfree(snapshot);
2834 }
2835
2836 return 0;
2837 }
2838
2839 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2840 {
2841 struct btrfs_inode *btrfs_inode;
2842 struct list_head splice;
2843
2844 INIT_LIST_HEAD(&splice);
2845
2846 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2847
2848 spin_lock(&root->fs_info->delalloc_lock);
2849
2850 while (!list_empty(&splice)) {
2851 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2852 delalloc_inodes);
2853
2854 list_del_init(&btrfs_inode->delalloc_inodes);
2855
2856 btrfs_invalidate_inodes(btrfs_inode->root);
2857 }
2858
2859 spin_unlock(&root->fs_info->delalloc_lock);
2860
2861 return 0;
2862 }
2863
2864 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2865 struct extent_io_tree *dirty_pages,
2866 int mark)
2867 {
2868 int ret;
2869 struct page *page;
2870 struct inode *btree_inode = root->fs_info->btree_inode;
2871 struct extent_buffer *eb;
2872 u64 start = 0;
2873 u64 end;
2874 u64 offset;
2875 unsigned long index;
2876
2877 while (1) {
2878 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2879 mark);
2880 if (ret)
2881 break;
2882
2883 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2884 while (start <= end) {
2885 index = start >> PAGE_CACHE_SHIFT;
2886 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2887 page = find_get_page(btree_inode->i_mapping, index);
2888 if (!page)
2889 continue;
2890 offset = page_offset(page);
2891
2892 spin_lock(&dirty_pages->buffer_lock);
2893 eb = radix_tree_lookup(
2894 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2895 offset >> PAGE_CACHE_SHIFT);
2896 spin_unlock(&dirty_pages->buffer_lock);
2897 if (eb) {
2898 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2899 &eb->bflags);
2900 atomic_set(&eb->refs, 1);
2901 }
2902 if (PageWriteback(page))
2903 end_page_writeback(page);
2904
2905 lock_page(page);
2906 if (PageDirty(page)) {
2907 clear_page_dirty_for_io(page);
2908 spin_lock_irq(&page->mapping->tree_lock);
2909 radix_tree_tag_clear(&page->mapping->page_tree,
2910 page_index(page),
2911 PAGECACHE_TAG_DIRTY);
2912 spin_unlock_irq(&page->mapping->tree_lock);
2913 }
2914
2915 page->mapping->a_ops->invalidatepage(page, 0);
2916 unlock_page(page);
2917 }
2918 }
2919
2920 return ret;
2921 }
2922
2923 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
2924 struct extent_io_tree *pinned_extents)
2925 {
2926 struct extent_io_tree *unpin;
2927 u64 start;
2928 u64 end;
2929 int ret;
2930
2931 unpin = pinned_extents;
2932 while (1) {
2933 ret = find_first_extent_bit(unpin, 0, &start, &end,
2934 EXTENT_DIRTY);
2935 if (ret)
2936 break;
2937
2938 /* opt_discard */
2939 ret = btrfs_error_discard_extent(root, start, end + 1 - start);
2940
2941 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2942 btrfs_error_unpin_extent_range(root, start, end);
2943 cond_resched();
2944 }
2945
2946 return 0;
2947 }
2948
2949 static int btrfs_cleanup_transaction(struct btrfs_root *root)
2950 {
2951 struct btrfs_transaction *t;
2952 LIST_HEAD(list);
2953
2954 WARN_ON(1);
2955
2956 mutex_lock(&root->fs_info->trans_mutex);
2957 mutex_lock(&root->fs_info->transaction_kthread_mutex);
2958
2959 list_splice_init(&root->fs_info->trans_list, &list);
2960 while (!list_empty(&list)) {
2961 t = list_entry(list.next, struct btrfs_transaction, list);
2962 if (!t)
2963 break;
2964
2965 btrfs_destroy_ordered_operations(root);
2966
2967 btrfs_destroy_ordered_extents(root);
2968
2969 btrfs_destroy_delayed_refs(t, root);
2970
2971 btrfs_block_rsv_release(root,
2972 &root->fs_info->trans_block_rsv,
2973 t->dirty_pages.dirty_bytes);
2974
2975 /* FIXME: cleanup wait for commit */
2976 t->in_commit = 1;
2977 t->blocked = 1;
2978 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
2979 wake_up(&root->fs_info->transaction_blocked_wait);
2980
2981 t->blocked = 0;
2982 if (waitqueue_active(&root->fs_info->transaction_wait))
2983 wake_up(&root->fs_info->transaction_wait);
2984 mutex_unlock(&root->fs_info->trans_mutex);
2985
2986 mutex_lock(&root->fs_info->trans_mutex);
2987 t->commit_done = 1;
2988 if (waitqueue_active(&t->commit_wait))
2989 wake_up(&t->commit_wait);
2990 mutex_unlock(&root->fs_info->trans_mutex);
2991
2992 mutex_lock(&root->fs_info->trans_mutex);
2993
2994 btrfs_destroy_pending_snapshots(t);
2995
2996 btrfs_destroy_delalloc_inodes(root);
2997
2998 spin_lock(&root->fs_info->new_trans_lock);
2999 root->fs_info->running_transaction = NULL;
3000 spin_unlock(&root->fs_info->new_trans_lock);
3001
3002 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3003 EXTENT_DIRTY);
3004
3005 btrfs_destroy_pinned_extent(root,
3006 root->fs_info->pinned_extents);
3007
3008 t->use_count = 0;
3009 list_del_init(&t->list);
3010 memset(t, 0, sizeof(*t));
3011 kmem_cache_free(btrfs_transaction_cachep, t);
3012 }
3013
3014 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3015 mutex_unlock(&root->fs_info->trans_mutex);
3016
3017 return 0;
3018 }
3019
3020 static struct extent_io_ops btree_extent_io_ops = {
3021 .write_cache_pages_lock_hook = btree_lock_page_hook,
3022 .readpage_end_io_hook = btree_readpage_end_io_hook,
3023 .submit_bio_hook = btree_submit_bio_hook,
3024 /* note we're sharing with inode.c for the merge bio hook */
3025 .merge_bio_hook = btrfs_merge_bio_hook,
3026 };
CJK support for tty framebuffer vt