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Add linux-next specific files for 20110716
[linux-2.6/next.git] / fs / btrfs / disk-io.c
blob1ac8db5dc0a31b9a742099956b121cd75ba0a1a6
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 <linux/ratelimit.h>
33 #include <asm/unaligned.h>
34 #include "compat.h"
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "async-thread.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "inode-map.h"
46
47 static struct extent_io_ops btree_extent_io_ops;
48 static void end_workqueue_fn(struct btrfs_work *work);
49 static void free_fs_root(struct btrfs_root *root);
50 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
51 int read_only);
52 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
53 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
54 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
55 struct btrfs_root *root);
56 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
57 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
58 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
59 struct extent_io_tree *dirty_pages,
60 int mark);
61 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
62 struct extent_io_tree *pinned_extents);
63 static int btrfs_cleanup_transaction(struct btrfs_root *root);
64
65 /*
66 * end_io_wq structs are used to do processing in task context when an IO is
67 * complete. This is used during reads to verify checksums, and it is used
68 * by writes to insert metadata for new file extents after IO is complete.
69 */
70 struct end_io_wq {
71 struct bio *bio;
72 bio_end_io_t *end_io;
73 void *private;
74 struct btrfs_fs_info *info;
75 int error;
76 int metadata;
77 struct list_head list;
78 struct btrfs_work work;
79 };
80
81 /*
82 * async submit bios are used to offload expensive checksumming
83 * onto the worker threads. They checksum file and metadata bios
84 * just before they are sent down the IO stack.
85 */
86 struct async_submit_bio {
87 struct inode *inode;
88 struct bio *bio;
89 struct list_head list;
90 extent_submit_bio_hook_t *submit_bio_start;
91 extent_submit_bio_hook_t *submit_bio_done;
92 int rw;
93 int mirror_num;
94 unsigned long bio_flags;
95 /*
96 * bio_offset is optional, can be used if the pages in the bio
97 * can't tell us where in the file the bio should go
98 */
99 u64 bio_offset;
100 struct btrfs_work work;
101 };
102
103 /* These are used to set the lockdep class on the extent buffer locks.
104 * The class is set by the readpage_end_io_hook after the buffer has
105 * passed csum validation but before the pages are unlocked.
106 *
107 * The lockdep class is also set by btrfs_init_new_buffer on freshly
108 * allocated blocks.
109 *
110 * The class is based on the level in the tree block, which allows lockdep
111 * to know that lower nodes nest inside the locks of higher nodes.
112 *
113 * We also add a check to make sure the highest level of the tree is
114 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
115 * code needs update as well.
116 */
117 #ifdef CONFIG_DEBUG_LOCK_ALLOC
118 # if BTRFS_MAX_LEVEL != 8
119 # error
120 # endif
121 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
122 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
123 /* leaf */
124 "btrfs-extent-00",
125 "btrfs-extent-01",
126 "btrfs-extent-02",
127 "btrfs-extent-03",
128 "btrfs-extent-04",
129 "btrfs-extent-05",
130 "btrfs-extent-06",
131 "btrfs-extent-07",
132 /* highest possible level */
133 "btrfs-extent-08",
134 };
135 #endif
136
137 /*
138 * extents on the btree inode are pretty simple, there's one extent
139 * that covers the entire device
140 */
141 static struct extent_map *btree_get_extent(struct inode *inode,
142 struct page *page, size_t pg_offset, u64 start, u64 len,
143 int create)
144 {
145 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
146 struct extent_map *em;
147 int ret;
148
149 read_lock(&em_tree->lock);
150 em = lookup_extent_mapping(em_tree, start, len);
151 if (em) {
152 em->bdev =
153 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
154 read_unlock(&em_tree->lock);
155 goto out;
156 }
157 read_unlock(&em_tree->lock);
158
159 em = alloc_extent_map();
160 if (!em) {
161 em = ERR_PTR(-ENOMEM);
162 goto out;
163 }
164 em->start = 0;
165 em->len = (u64)-1;
166 em->block_len = (u64)-1;
167 em->block_start = 0;
168 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
169
170 write_lock(&em_tree->lock);
171 ret = add_extent_mapping(em_tree, em);
172 if (ret == -EEXIST) {
173 u64 failed_start = em->start;
174 u64 failed_len = em->len;
175
176 free_extent_map(em);
177 em = lookup_extent_mapping(em_tree, start, len);
178 if (em) {
179 ret = 0;
180 } else {
181 em = lookup_extent_mapping(em_tree, failed_start,
182 failed_len);
183 ret = -EIO;
184 }
185 } else if (ret) {
186 free_extent_map(em);
187 em = NULL;
188 }
189 write_unlock(&em_tree->lock);
190
191 if (ret)
192 em = ERR_PTR(ret);
193 out:
194 return em;
195 }
196
197 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
198 {
199 return crc32c(seed, data, len);
200 }
201
202 void btrfs_csum_final(u32 crc, char *result)
203 {
204 put_unaligned_le32(~crc, result);
205 }
206
207 /*
208 * compute the csum for a btree block, and either verify it or write it
209 * into the csum field of the block.
210 */
211 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
212 int verify)
213 {
214 u16 csum_size =
215 btrfs_super_csum_size(&root->fs_info->super_copy);
216 char *result = NULL;
217 unsigned long len;
218 unsigned long cur_len;
219 unsigned long offset = BTRFS_CSUM_SIZE;
220 char *map_token = NULL;
221 char *kaddr;
222 unsigned long map_start;
223 unsigned long map_len;
224 int err;
225 u32 crc = ~(u32)0;
226 unsigned long inline_result;
227
228 len = buf->len - offset;
229 while (len > 0) {
230 err = map_private_extent_buffer(buf, offset, 32,
231 &map_token, &kaddr,
232 &map_start, &map_len, KM_USER0);
233 if (err)
234 return 1;
235 cur_len = min(len, map_len - (offset - map_start));
236 crc = btrfs_csum_data(root, kaddr + offset - map_start,
237 crc, cur_len);
238 len -= cur_len;
239 offset += cur_len;
240 unmap_extent_buffer(buf, map_token, KM_USER0);
241 }
242 if (csum_size > sizeof(inline_result)) {
243 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
244 if (!result)
245 return 1;
246 } else {
247 result = (char *)&inline_result;
248 }
249
250 btrfs_csum_final(crc, result);
251
252 if (verify) {
253 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
254 u32 val;
255 u32 found = 0;
256 memcpy(&found, result, csum_size);
257
258 read_extent_buffer(buf, &val, 0, csum_size);
259 printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
260 "failed on %llu wanted %X found %X "
261 "level %d\n",
262 root->fs_info->sb->s_id,
263 (unsigned long long)buf->start, val, found,
264 btrfs_header_level(buf));
265 if (result != (char *)&inline_result)
266 kfree(result);
267 return 1;
268 }
269 } else {
270 write_extent_buffer(buf, result, 0, csum_size);
271 }
272 if (result != (char *)&inline_result)
273 kfree(result);
274 return 0;
275 }
276
277 /*
278 * we can't consider a given block up to date unless the transid of the
279 * block matches the transid in the parent node's pointer. This is how we
280 * detect blocks that either didn't get written at all or got written
281 * in the wrong place.
282 */
283 static int verify_parent_transid(struct extent_io_tree *io_tree,
284 struct extent_buffer *eb, u64 parent_transid)
285 {
286 struct extent_state *cached_state = NULL;
287 int ret;
288
289 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
290 return 0;
291
292 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
293 0, &cached_state, GFP_NOFS);
294 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
295 btrfs_header_generation(eb) == parent_transid) {
296 ret = 0;
297 goto out;
298 }
299 printk_ratelimited("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 ret = 1;
305 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
306 out:
307 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
308 &cached_state, GFP_NOFS);
309 return ret;
310 }
311
312 /*
313 * helper to read a given tree block, doing retries as required when
314 * the checksums don't match and we have alternate mirrors to try.
315 */
316 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
317 struct extent_buffer *eb,
318 u64 start, u64 parent_transid)
319 {
320 struct extent_io_tree *io_tree;
321 int ret;
322 int num_copies = 0;
323 int mirror_num = 0;
324
325 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
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 /*
335 * This buffer's crc is fine, but its contents are corrupted, so
336 * there is no reason to read the other copies, they won't be
337 * any less wrong.
338 */
339 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
340 return ret;
341
342 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
343 eb->start, eb->len);
344 if (num_copies == 1)
345 return ret;
346
347 mirror_num++;
348 if (mirror_num > num_copies)
349 return ret;
350 }
351 return -EIO;
352 }
353
354 /*
355 * checksum a dirty tree block before IO. This has extra checks to make sure
356 * we only fill in the checksum field in the first page of a multi-page block
357 */
358
359 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
360 {
361 struct extent_io_tree *tree;
362 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
363 u64 found_start;
364 unsigned long len;
365 struct extent_buffer *eb;
366 int ret;
367
368 tree = &BTRFS_I(page->mapping->host)->io_tree;
369
370 if (page->private == EXTENT_PAGE_PRIVATE) {
371 WARN_ON(1);
372 goto out;
373 }
374 if (!page->private) {
375 WARN_ON(1);
376 goto out;
377 }
378 len = page->private >> 2;
379 WARN_ON(len == 0);
380
381 eb = alloc_extent_buffer(tree, start, len, page);
382 if (eb == NULL) {
383 WARN_ON(1);
384 goto out;
385 }
386 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
387 btrfs_header_generation(eb));
388 BUG_ON(ret);
389 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
390
391 found_start = btrfs_header_bytenr(eb);
392 if (found_start != start) {
393 WARN_ON(1);
394 goto err;
395 }
396 if (eb->first_page != page) {
397 WARN_ON(1);
398 goto err;
399 }
400 if (!PageUptodate(page)) {
401 WARN_ON(1);
402 goto err;
403 }
404 csum_tree_block(root, eb, 0);
405 err:
406 free_extent_buffer(eb);
407 out:
408 return 0;
409 }
410
411 static int check_tree_block_fsid(struct btrfs_root *root,
412 struct extent_buffer *eb)
413 {
414 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
415 u8 fsid[BTRFS_UUID_SIZE];
416 int ret = 1;
417
418 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
419 BTRFS_FSID_SIZE);
420 while (fs_devices) {
421 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
422 ret = 0;
423 break;
424 }
425 fs_devices = fs_devices->seed;
426 }
427 return ret;
428 }
429
430 #define CORRUPT(reason, eb, root, slot) \
431 printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
432 "root=%llu, slot=%d\n", reason, \
433 (unsigned long long)btrfs_header_bytenr(eb), \
434 (unsigned long long)root->objectid, slot)
435
436 static noinline int check_leaf(struct btrfs_root *root,
437 struct extent_buffer *leaf)
438 {
439 struct btrfs_key key;
440 struct btrfs_key leaf_key;
441 u32 nritems = btrfs_header_nritems(leaf);
442 int slot;
443
444 if (nritems == 0)
445 return 0;
446
447 /* Check the 0 item */
448 if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
449 BTRFS_LEAF_DATA_SIZE(root)) {
450 CORRUPT("invalid item offset size pair", leaf, root, 0);
451 return -EIO;
452 }
453
454 /*
455 * Check to make sure each items keys are in the correct order and their
456 * offsets make sense. We only have to loop through nritems-1 because
457 * we check the current slot against the next slot, which verifies the
458 * next slot's offset+size makes sense and that the current's slot
459 * offset is correct.
460 */
461 for (slot = 0; slot < nritems - 1; slot++) {
462 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
463 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
464
465 /* Make sure the keys are in the right order */
466 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
467 CORRUPT("bad key order", leaf, root, slot);
468 return -EIO;
469 }
470
471 /*
472 * Make sure the offset and ends are right, remember that the
473 * item data starts at the end of the leaf and grows towards the
474 * front.
475 */
476 if (btrfs_item_offset_nr(leaf, slot) !=
477 btrfs_item_end_nr(leaf, slot + 1)) {
478 CORRUPT("slot offset bad", leaf, root, slot);
479 return -EIO;
480 }
481
482 /*
483 * Check to make sure that we don't point outside of the leaf,
484 * just incase all the items are consistent to eachother, but
485 * all point outside of the leaf.
486 */
487 if (btrfs_item_end_nr(leaf, slot) >
488 BTRFS_LEAF_DATA_SIZE(root)) {
489 CORRUPT("slot end outside of leaf", leaf, root, slot);
490 return -EIO;
491 }
492 }
493
494 return 0;
495 }
496
497 #ifdef CONFIG_DEBUG_LOCK_ALLOC
498 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
499 {
500 lockdep_set_class_and_name(&eb->lock,
501 &btrfs_eb_class[level],
502 btrfs_eb_name[level]);
503 }
504 #endif
505
506 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
507 struct extent_state *state)
508 {
509 struct extent_io_tree *tree;
510 u64 found_start;
511 int found_level;
512 unsigned long len;
513 struct extent_buffer *eb;
514 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
515 int ret = 0;
516
517 tree = &BTRFS_I(page->mapping->host)->io_tree;
518 if (page->private == EXTENT_PAGE_PRIVATE)
519 goto out;
520 if (!page->private)
521 goto out;
522
523 len = page->private >> 2;
524 WARN_ON(len == 0);
525
526 eb = alloc_extent_buffer(tree, start, len, page);
527 if (eb == NULL) {
528 ret = -EIO;
529 goto out;
530 }
531
532 found_start = btrfs_header_bytenr(eb);
533 if (found_start != start) {
534 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
535 "%llu %llu\n",
536 (unsigned long long)found_start,
537 (unsigned long long)eb->start);
538 ret = -EIO;
539 goto err;
540 }
541 if (eb->first_page != page) {
542 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
543 eb->first_page->index, page->index);
544 WARN_ON(1);
545 ret = -EIO;
546 goto err;
547 }
548 if (check_tree_block_fsid(root, eb)) {
549 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
550 (unsigned long long)eb->start);
551 ret = -EIO;
552 goto err;
553 }
554 found_level = btrfs_header_level(eb);
555
556 btrfs_set_buffer_lockdep_class(eb, found_level);
557
558 ret = csum_tree_block(root, eb, 1);
559 if (ret) {
560 ret = -EIO;
561 goto err;
562 }
563
564 /*
565 * If this is a leaf block and it is corrupt, set the corrupt bit so
566 * that we don't try and read the other copies of this block, just
567 * return -EIO.
568 */
569 if (found_level == 0 && check_leaf(root, eb)) {
570 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
571 ret = -EIO;
572 }
573
574 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
575 end = eb->start + end - 1;
576 err:
577 free_extent_buffer(eb);
578 out:
579 return ret;
580 }
581
582 static void end_workqueue_bio(struct bio *bio, int err)
583 {
584 struct end_io_wq *end_io_wq = bio->bi_private;
585 struct btrfs_fs_info *fs_info;
586
587 fs_info = end_io_wq->info;
588 end_io_wq->error = err;
589 end_io_wq->work.func = end_workqueue_fn;
590 end_io_wq->work.flags = 0;
591
592 if (bio->bi_rw & REQ_WRITE) {
593 if (end_io_wq->metadata == 1)
594 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
595 &end_io_wq->work);
596 else if (end_io_wq->metadata == 2)
597 btrfs_queue_worker(&fs_info->endio_freespace_worker,
598 &end_io_wq->work);
599 else
600 btrfs_queue_worker(&fs_info->endio_write_workers,
601 &end_io_wq->work);
602 } else {
603 if (end_io_wq->metadata)
604 btrfs_queue_worker(&fs_info->endio_meta_workers,
605 &end_io_wq->work);
606 else
607 btrfs_queue_worker(&fs_info->endio_workers,
608 &end_io_wq->work);
609 }
610 }
611
612 /*
613 * For the metadata arg you want
614 *
615 * 0 - if data
616 * 1 - if normal metadta
617 * 2 - if writing to the free space cache area
618 */
619 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
620 int metadata)
621 {
622 struct end_io_wq *end_io_wq;
623 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
624 if (!end_io_wq)
625 return -ENOMEM;
626
627 end_io_wq->private = bio->bi_private;
628 end_io_wq->end_io = bio->bi_end_io;
629 end_io_wq->info = info;
630 end_io_wq->error = 0;
631 end_io_wq->bio = bio;
632 end_io_wq->metadata = metadata;
633
634 bio->bi_private = end_io_wq;
635 bio->bi_end_io = end_workqueue_bio;
636 return 0;
637 }
638
639 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
640 {
641 unsigned long limit = min_t(unsigned long,
642 info->workers.max_workers,
643 info->fs_devices->open_devices);
644 return 256 * limit;
645 }
646
647 static void run_one_async_start(struct btrfs_work *work)
648 {
649 struct async_submit_bio *async;
650
651 async = container_of(work, struct async_submit_bio, work);
652 async->submit_bio_start(async->inode, async->rw, async->bio,
653 async->mirror_num, async->bio_flags,
654 async->bio_offset);
655 }
656
657 static void run_one_async_done(struct btrfs_work *work)
658 {
659 struct btrfs_fs_info *fs_info;
660 struct async_submit_bio *async;
661 int limit;
662
663 async = container_of(work, struct async_submit_bio, work);
664 fs_info = BTRFS_I(async->inode)->root->fs_info;
665
666 limit = btrfs_async_submit_limit(fs_info);
667 limit = limit * 2 / 3;
668
669 atomic_dec(&fs_info->nr_async_submits);
670
671 if (atomic_read(&fs_info->nr_async_submits) < limit &&
672 waitqueue_active(&fs_info->async_submit_wait))
673 wake_up(&fs_info->async_submit_wait);
674
675 async->submit_bio_done(async->inode, async->rw, async->bio,
676 async->mirror_num, async->bio_flags,
677 async->bio_offset);
678 }
679
680 static void run_one_async_free(struct btrfs_work *work)
681 {
682 struct async_submit_bio *async;
683
684 async = container_of(work, struct async_submit_bio, work);
685 kfree(async);
686 }
687
688 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
689 int rw, struct bio *bio, int mirror_num,
690 unsigned long bio_flags,
691 u64 bio_offset,
692 extent_submit_bio_hook_t *submit_bio_start,
693 extent_submit_bio_hook_t *submit_bio_done)
694 {
695 struct async_submit_bio *async;
696
697 async = kmalloc(sizeof(*async), GFP_NOFS);
698 if (!async)
699 return -ENOMEM;
700
701 async->inode = inode;
702 async->rw = rw;
703 async->bio = bio;
704 async->mirror_num = mirror_num;
705 async->submit_bio_start = submit_bio_start;
706 async->submit_bio_done = submit_bio_done;
707
708 async->work.func = run_one_async_start;
709 async->work.ordered_func = run_one_async_done;
710 async->work.ordered_free = run_one_async_free;
711
712 async->work.flags = 0;
713 async->bio_flags = bio_flags;
714 async->bio_offset = bio_offset;
715
716 atomic_inc(&fs_info->nr_async_submits);
717
718 if (rw & REQ_SYNC)
719 btrfs_set_work_high_prio(&async->work);
720
721 btrfs_queue_worker(&fs_info->workers, &async->work);
722
723 while (atomic_read(&fs_info->async_submit_draining) &&
724 atomic_read(&fs_info->nr_async_submits)) {
725 wait_event(fs_info->async_submit_wait,
726 (atomic_read(&fs_info->nr_async_submits) == 0));
727 }
728
729 return 0;
730 }
731
732 static int btree_csum_one_bio(struct bio *bio)
733 {
734 struct bio_vec *bvec = bio->bi_io_vec;
735 int bio_index = 0;
736 struct btrfs_root *root;
737
738 WARN_ON(bio->bi_vcnt <= 0);
739 while (bio_index < bio->bi_vcnt) {
740 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
741 csum_dirty_buffer(root, bvec->bv_page);
742 bio_index++;
743 bvec++;
744 }
745 return 0;
746 }
747
748 static int __btree_submit_bio_start(struct inode *inode, int rw,
749 struct bio *bio, int mirror_num,
750 unsigned long bio_flags,
751 u64 bio_offset)
752 {
753 /*
754 * when we're called for a write, we're already in the async
755 * submission context. Just jump into btrfs_map_bio
756 */
757 btree_csum_one_bio(bio);
758 return 0;
759 }
760
761 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
762 int mirror_num, unsigned long bio_flags,
763 u64 bio_offset)
764 {
765 /*
766 * when we're called for a write, we're already in the async
767 * submission context. Just jump into btrfs_map_bio
768 */
769 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
770 }
771
772 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
773 int mirror_num, unsigned long bio_flags,
774 u64 bio_offset)
775 {
776 int ret;
777
778 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
779 bio, 1);
780 BUG_ON(ret);
781
782 if (!(rw & REQ_WRITE)) {
783 /*
784 * called for a read, do the setup so that checksum validation
785 * can happen in the async kernel threads
786 */
787 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
788 mirror_num, 0);
789 }
790
791 /*
792 * kthread helpers are used to submit writes so that checksumming
793 * can happen in parallel across all CPUs
794 */
795 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
796 inode, rw, bio, mirror_num, 0,
797 bio_offset,
798 __btree_submit_bio_start,
799 __btree_submit_bio_done);
800 }
801
802 #ifdef CONFIG_MIGRATION
803 static int btree_migratepage(struct address_space *mapping,
804 struct page *newpage, struct page *page)
805 {
806 /*
807 * we can't safely write a btree page from here,
808 * we haven't done the locking hook
809 */
810 if (PageDirty(page))
811 return -EAGAIN;
812 /*
813 * Buffers may be managed in a filesystem specific way.
814 * We must have no buffers or drop them.
815 */
816 if (page_has_private(page) &&
817 !try_to_release_page(page, GFP_KERNEL))
818 return -EAGAIN;
819 return migrate_page(mapping, newpage, page);
820 }
821 #endif
822
823 static int btree_writepage(struct page *page, struct writeback_control *wbc)
824 {
825 struct extent_io_tree *tree;
826 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
827 struct extent_buffer *eb;
828 int was_dirty;
829
830 tree = &BTRFS_I(page->mapping->host)->io_tree;
831 if (!(current->flags & PF_MEMALLOC)) {
832 return extent_write_full_page(tree, page,
833 btree_get_extent, wbc);
834 }
835
836 redirty_page_for_writepage(wbc, page);
837 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
838 WARN_ON(!eb);
839
840 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
841 if (!was_dirty) {
842 spin_lock(&root->fs_info->delalloc_lock);
843 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
844 spin_unlock(&root->fs_info->delalloc_lock);
845 }
846 free_extent_buffer(eb);
847
848 unlock_page(page);
849 return 0;
850 }
851
852 static int btree_writepages(struct address_space *mapping,
853 struct writeback_control *wbc)
854 {
855 struct extent_io_tree *tree;
856 tree = &BTRFS_I(mapping->host)->io_tree;
857 if (wbc->sync_mode == WB_SYNC_NONE) {
858 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
859 u64 num_dirty;
860 unsigned long thresh = 32 * 1024 * 1024;
861
862 if (wbc->for_kupdate)
863 return 0;
864
865 /* this is a bit racy, but that's ok */
866 num_dirty = root->fs_info->dirty_metadata_bytes;
867 if (num_dirty < thresh)
868 return 0;
869 }
870 return extent_writepages(tree, mapping, btree_get_extent, wbc);
871 }
872
873 static int btree_readpage(struct file *file, struct page *page)
874 {
875 struct extent_io_tree *tree;
876 tree = &BTRFS_I(page->mapping->host)->io_tree;
877 return extent_read_full_page(tree, page, btree_get_extent);
878 }
879
880 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
881 {
882 struct extent_io_tree *tree;
883 struct extent_map_tree *map;
884 int ret;
885
886 if (PageWriteback(page) || PageDirty(page))
887 return 0;
888
889 tree = &BTRFS_I(page->mapping->host)->io_tree;
890 map = &BTRFS_I(page->mapping->host)->extent_tree;
891
892 ret = try_release_extent_state(map, tree, page, gfp_flags);
893 if (!ret)
894 return 0;
895
896 ret = try_release_extent_buffer(tree, page);
897 if (ret == 1) {
898 ClearPagePrivate(page);
899 set_page_private(page, 0);
900 page_cache_release(page);
901 }
902
903 return ret;
904 }
905
906 static void btree_invalidatepage(struct page *page, unsigned long offset)
907 {
908 struct extent_io_tree *tree;
909 tree = &BTRFS_I(page->mapping->host)->io_tree;
910 extent_invalidatepage(tree, page, offset);
911 btree_releasepage(page, GFP_NOFS);
912 if (PagePrivate(page)) {
913 printk(KERN_WARNING "btrfs warning page private not zero "
914 "on page %llu\n", (unsigned long long)page_offset(page));
915 ClearPagePrivate(page);
916 set_page_private(page, 0);
917 page_cache_release(page);
918 }
919 }
920
921 static const struct address_space_operations btree_aops = {
922 .readpage = btree_readpage,
923 .writepage = btree_writepage,
924 .writepages = btree_writepages,
925 .releasepage = btree_releasepage,
926 .invalidatepage = btree_invalidatepage,
927 #ifdef CONFIG_MIGRATION
928 .migratepage = btree_migratepage,
929 #endif
930 };
931
932 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
933 u64 parent_transid)
934 {
935 struct extent_buffer *buf = NULL;
936 struct inode *btree_inode = root->fs_info->btree_inode;
937 int ret = 0;
938
939 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
940 if (!buf)
941 return 0;
942 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
943 buf, 0, 0, btree_get_extent, 0);
944 free_extent_buffer(buf);
945 return ret;
946 }
947
948 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
949 u64 bytenr, u32 blocksize)
950 {
951 struct inode *btree_inode = root->fs_info->btree_inode;
952 struct extent_buffer *eb;
953 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
954 bytenr, blocksize);
955 return eb;
956 }
957
958 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
959 u64 bytenr, u32 blocksize)
960 {
961 struct inode *btree_inode = root->fs_info->btree_inode;
962 struct extent_buffer *eb;
963
964 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
965 bytenr, blocksize, NULL);
966 return eb;
967 }
968
969
970 int btrfs_write_tree_block(struct extent_buffer *buf)
971 {
972 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
973 buf->start + buf->len - 1);
974 }
975
976 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
977 {
978 return filemap_fdatawait_range(buf->first_page->mapping,
979 buf->start, buf->start + buf->len - 1);
980 }
981
982 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
983 u32 blocksize, u64 parent_transid)
984 {
985 struct extent_buffer *buf = NULL;
986 int ret;
987
988 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
989 if (!buf)
990 return NULL;
991
992 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
993
994 if (ret == 0)
995 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
996 return buf;
997
998 }
999
1000 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1001 struct extent_buffer *buf)
1002 {
1003 struct inode *btree_inode = root->fs_info->btree_inode;
1004 if (btrfs_header_generation(buf) ==
1005 root->fs_info->running_transaction->transid) {
1006 btrfs_assert_tree_locked(buf);
1007
1008 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1009 spin_lock(&root->fs_info->delalloc_lock);
1010 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1011 root->fs_info->dirty_metadata_bytes -= buf->len;
1012 else
1013 WARN_ON(1);
1014 spin_unlock(&root->fs_info->delalloc_lock);
1015 }
1016
1017 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1018 btrfs_set_lock_blocking(buf);
1019 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1020 buf);
1021 }
1022 return 0;
1023 }
1024
1025 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1026 u32 stripesize, struct btrfs_root *root,
1027 struct btrfs_fs_info *fs_info,
1028 u64 objectid)
1029 {
1030 root->node = NULL;
1031 root->commit_root = NULL;
1032 root->sectorsize = sectorsize;
1033 root->nodesize = nodesize;
1034 root->leafsize = leafsize;
1035 root->stripesize = stripesize;
1036 root->ref_cows = 0;
1037 root->track_dirty = 0;
1038 root->in_radix = 0;
1039 root->orphan_item_inserted = 0;
1040 root->orphan_cleanup_state = 0;
1041
1042 root->fs_info = fs_info;
1043 root->objectid = objectid;
1044 root->last_trans = 0;
1045 root->highest_objectid = 0;
1046 root->name = NULL;
1047 root->inode_tree = RB_ROOT;
1048 INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1049 root->block_rsv = NULL;
1050 root->orphan_block_rsv = NULL;
1051
1052 INIT_LIST_HEAD(&root->dirty_list);
1053 INIT_LIST_HEAD(&root->orphan_list);
1054 INIT_LIST_HEAD(&root->root_list);
1055 spin_lock_init(&root->orphan_lock);
1056 spin_lock_init(&root->inode_lock);
1057 spin_lock_init(&root->accounting_lock);
1058 mutex_init(&root->objectid_mutex);
1059 mutex_init(&root->log_mutex);
1060 init_waitqueue_head(&root->log_writer_wait);
1061 init_waitqueue_head(&root->log_commit_wait[0]);
1062 init_waitqueue_head(&root->log_commit_wait[1]);
1063 atomic_set(&root->log_commit[0], 0);
1064 atomic_set(&root->log_commit[1], 0);
1065 atomic_set(&root->log_writers, 0);
1066 root->log_batch = 0;
1067 root->log_transid = 0;
1068 root->last_log_commit = 0;
1069 extent_io_tree_init(&root->dirty_log_pages,
1070 fs_info->btree_inode->i_mapping);
1071
1072 memset(&root->root_key, 0, sizeof(root->root_key));
1073 memset(&root->root_item, 0, sizeof(root->root_item));
1074 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1075 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1076 root->defrag_trans_start = fs_info->generation;
1077 init_completion(&root->kobj_unregister);
1078 root->defrag_running = 0;
1079 root->root_key.objectid = objectid;
1080 root->anon_super.s_root = NULL;
1081 root->anon_super.s_dev = 0;
1082 INIT_LIST_HEAD(&root->anon_super.s_list);
1083 INIT_LIST_HEAD(&root->anon_super.s_instances);
1084 init_rwsem(&root->anon_super.s_umount);
1085
1086 return 0;
1087 }
1088
1089 static int find_and_setup_root(struct btrfs_root *tree_root,
1090 struct btrfs_fs_info *fs_info,
1091 u64 objectid,
1092 struct btrfs_root *root)
1093 {
1094 int ret;
1095 u32 blocksize;
1096 u64 generation;
1097
1098 __setup_root(tree_root->nodesize, tree_root->leafsize,
1099 tree_root->sectorsize, tree_root->stripesize,
1100 root, fs_info, objectid);
1101 ret = btrfs_find_last_root(tree_root, objectid,
1102 &root->root_item, &root->root_key);
1103 if (ret > 0)
1104 return -ENOENT;
1105 BUG_ON(ret);
1106
1107 generation = btrfs_root_generation(&root->root_item);
1108 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1109 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1110 blocksize, generation);
1111 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1112 free_extent_buffer(root->node);
1113 return -EIO;
1114 }
1115 root->commit_root = btrfs_root_node(root);
1116 return 0;
1117 }
1118
1119 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1120 struct btrfs_fs_info *fs_info)
1121 {
1122 struct btrfs_root *root;
1123 struct btrfs_root *tree_root = fs_info->tree_root;
1124 struct extent_buffer *leaf;
1125
1126 root = kzalloc(sizeof(*root), GFP_NOFS);
1127 if (!root)
1128 return ERR_PTR(-ENOMEM);
1129
1130 __setup_root(tree_root->nodesize, tree_root->leafsize,
1131 tree_root->sectorsize, tree_root->stripesize,
1132 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1133
1134 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1135 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1136 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1137 /*
1138 * log trees do not get reference counted because they go away
1139 * before a real commit is actually done. They do store pointers
1140 * to file data extents, and those reference counts still get
1141 * updated (along with back refs to the log tree).
1142 */
1143 root->ref_cows = 0;
1144
1145 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1146 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1147 if (IS_ERR(leaf)) {
1148 kfree(root);
1149 return ERR_CAST(leaf);
1150 }
1151
1152 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1153 btrfs_set_header_bytenr(leaf, leaf->start);
1154 btrfs_set_header_generation(leaf, trans->transid);
1155 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1156 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1157 root->node = leaf;
1158
1159 write_extent_buffer(root->node, root->fs_info->fsid,
1160 (unsigned long)btrfs_header_fsid(root->node),
1161 BTRFS_FSID_SIZE);
1162 btrfs_mark_buffer_dirty(root->node);
1163 btrfs_tree_unlock(root->node);
1164 return root;
1165 }
1166
1167 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1168 struct btrfs_fs_info *fs_info)
1169 {
1170 struct btrfs_root *log_root;
1171
1172 log_root = alloc_log_tree(trans, fs_info);
1173 if (IS_ERR(log_root))
1174 return PTR_ERR(log_root);
1175 WARN_ON(fs_info->log_root_tree);
1176 fs_info->log_root_tree = log_root;
1177 return 0;
1178 }
1179
1180 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1181 struct btrfs_root *root)
1182 {
1183 struct btrfs_root *log_root;
1184 struct btrfs_inode_item *inode_item;
1185
1186 log_root = alloc_log_tree(trans, root->fs_info);
1187 if (IS_ERR(log_root))
1188 return PTR_ERR(log_root);
1189
1190 log_root->last_trans = trans->transid;
1191 log_root->root_key.offset = root->root_key.objectid;
1192
1193 inode_item = &log_root->root_item.inode;
1194 inode_item->generation = cpu_to_le64(1);
1195 inode_item->size = cpu_to_le64(3);
1196 inode_item->nlink = cpu_to_le32(1);
1197 inode_item->nbytes = cpu_to_le64(root->leafsize);
1198 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1199
1200 btrfs_set_root_node(&log_root->root_item, log_root->node);
1201
1202 WARN_ON(root->log_root);
1203 root->log_root = log_root;
1204 root->log_transid = 0;
1205 root->last_log_commit = 0;
1206 return 0;
1207 }
1208
1209 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1210 struct btrfs_key *location)
1211 {
1212 struct btrfs_root *root;
1213 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1214 struct btrfs_path *path;
1215 struct extent_buffer *l;
1216 u64 generation;
1217 u32 blocksize;
1218 int ret = 0;
1219
1220 root = kzalloc(sizeof(*root), GFP_NOFS);
1221 if (!root)
1222 return ERR_PTR(-ENOMEM);
1223 if (location->offset == (u64)-1) {
1224 ret = find_and_setup_root(tree_root, fs_info,
1225 location->objectid, root);
1226 if (ret) {
1227 kfree(root);
1228 return ERR_PTR(ret);
1229 }
1230 goto out;
1231 }
1232
1233 __setup_root(tree_root->nodesize, tree_root->leafsize,
1234 tree_root->sectorsize, tree_root->stripesize,
1235 root, fs_info, location->objectid);
1236
1237 path = btrfs_alloc_path();
1238 if (!path) {
1239 kfree(root);
1240 return ERR_PTR(-ENOMEM);
1241 }
1242 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1243 if (ret == 0) {
1244 l = path->nodes[0];
1245 read_extent_buffer(l, &root->root_item,
1246 btrfs_item_ptr_offset(l, path->slots[0]),
1247 sizeof(root->root_item));
1248 memcpy(&root->root_key, location, sizeof(*location));
1249 }
1250 btrfs_free_path(path);
1251 if (ret) {
1252 kfree(root);
1253 if (ret > 0)
1254 ret = -ENOENT;
1255 return ERR_PTR(ret);
1256 }
1257
1258 generation = btrfs_root_generation(&root->root_item);
1259 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1260 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1261 blocksize, generation);
1262 root->commit_root = btrfs_root_node(root);
1263 BUG_ON(!root->node);
1264 out:
1265 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1266 root->ref_cows = 1;
1267 btrfs_check_and_init_root_item(&root->root_item);
1268 }
1269
1270 return root;
1271 }
1272
1273 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1274 struct btrfs_key *location)
1275 {
1276 struct btrfs_root *root;
1277 int ret;
1278
1279 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1280 return fs_info->tree_root;
1281 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1282 return fs_info->extent_root;
1283 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1284 return fs_info->chunk_root;
1285 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1286 return fs_info->dev_root;
1287 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1288 return fs_info->csum_root;
1289 again:
1290 spin_lock(&fs_info->fs_roots_radix_lock);
1291 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1292 (unsigned long)location->objectid);
1293 spin_unlock(&fs_info->fs_roots_radix_lock);
1294 if (root)
1295 return root;
1296
1297 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1298 if (IS_ERR(root))
1299 return root;
1300
1301 root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1302 root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1303 GFP_NOFS);
1304 if (!root->free_ino_pinned || !root->free_ino_ctl) {
1305 ret = -ENOMEM;
1306 goto fail;
1307 }
1308
1309 btrfs_init_free_ino_ctl(root);
1310 mutex_init(&root->fs_commit_mutex);
1311 spin_lock_init(&root->cache_lock);
1312 init_waitqueue_head(&root->cache_wait);
1313
1314 ret = set_anon_super(&root->anon_super, NULL);
1315 if (ret)
1316 goto fail;
1317
1318 if (btrfs_root_refs(&root->root_item) == 0) {
1319 ret = -ENOENT;
1320 goto fail;
1321 }
1322
1323 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1324 if (ret < 0)
1325 goto fail;
1326 if (ret == 0)
1327 root->orphan_item_inserted = 1;
1328
1329 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1330 if (ret)
1331 goto fail;
1332
1333 spin_lock(&fs_info->fs_roots_radix_lock);
1334 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1335 (unsigned long)root->root_key.objectid,
1336 root);
1337 if (ret == 0)
1338 root->in_radix = 1;
1339
1340 spin_unlock(&fs_info->fs_roots_radix_lock);
1341 radix_tree_preload_end();
1342 if (ret) {
1343 if (ret == -EEXIST) {
1344 free_fs_root(root);
1345 goto again;
1346 }
1347 goto fail;
1348 }
1349
1350 ret = btrfs_find_dead_roots(fs_info->tree_root,
1351 root->root_key.objectid);
1352 WARN_ON(ret);
1353 return root;
1354 fail:
1355 free_fs_root(root);
1356 return ERR_PTR(ret);
1357 }
1358
1359 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1360 {
1361 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1362 int ret = 0;
1363 struct btrfs_device *device;
1364 struct backing_dev_info *bdi;
1365
1366 rcu_read_lock();
1367 list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1368 if (!device->bdev)
1369 continue;
1370 bdi = blk_get_backing_dev_info(device->bdev);
1371 if (bdi && bdi_congested(bdi, bdi_bits)) {
1372 ret = 1;
1373 break;
1374 }
1375 }
1376 rcu_read_unlock();
1377 return ret;
1378 }
1379
1380 /*
1381 * If this fails, caller must call bdi_destroy() to get rid of the
1382 * bdi again.
1383 */
1384 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1385 {
1386 int err;
1387
1388 bdi->capabilities = BDI_CAP_MAP_COPY;
1389 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1390 if (err)
1391 return err;
1392
1393 bdi->ra_pages = default_backing_dev_info.ra_pages;
1394 bdi->congested_fn = btrfs_congested_fn;
1395 bdi->congested_data = info;
1396 return 0;
1397 }
1398
1399 static int bio_ready_for_csum(struct bio *bio)
1400 {
1401 u64 length = 0;
1402 u64 buf_len = 0;
1403 u64 start = 0;
1404 struct page *page;
1405 struct extent_io_tree *io_tree = NULL;
1406 struct bio_vec *bvec;
1407 int i;
1408 int ret;
1409
1410 bio_for_each_segment(bvec, bio, i) {
1411 page = bvec->bv_page;
1412 if (page->private == EXTENT_PAGE_PRIVATE) {
1413 length += bvec->bv_len;
1414 continue;
1415 }
1416 if (!page->private) {
1417 length += bvec->bv_len;
1418 continue;
1419 }
1420 length = bvec->bv_len;
1421 buf_len = page->private >> 2;
1422 start = page_offset(page) + bvec->bv_offset;
1423 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1424 }
1425 /* are we fully contained in this bio? */
1426 if (buf_len <= length)
1427 return 1;
1428
1429 ret = extent_range_uptodate(io_tree, start + length,
1430 start + buf_len - 1);
1431 return ret;
1432 }
1433
1434 /*
1435 * called by the kthread helper functions to finally call the bio end_io
1436 * functions. This is where read checksum verification actually happens
1437 */
1438 static void end_workqueue_fn(struct btrfs_work *work)
1439 {
1440 struct bio *bio;
1441 struct end_io_wq *end_io_wq;
1442 struct btrfs_fs_info *fs_info;
1443 int error;
1444
1445 end_io_wq = container_of(work, struct end_io_wq, work);
1446 bio = end_io_wq->bio;
1447 fs_info = end_io_wq->info;
1448
1449 /* metadata bio reads are special because the whole tree block must
1450 * be checksummed at once. This makes sure the entire block is in
1451 * ram and up to date before trying to verify things. For
1452 * blocksize <= pagesize, it is basically a noop
1453 */
1454 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1455 !bio_ready_for_csum(bio)) {
1456 btrfs_queue_worker(&fs_info->endio_meta_workers,
1457 &end_io_wq->work);
1458 return;
1459 }
1460 error = end_io_wq->error;
1461 bio->bi_private = end_io_wq->private;
1462 bio->bi_end_io = end_io_wq->end_io;
1463 kfree(end_io_wq);
1464 bio_endio(bio, error);
1465 }
1466
1467 static int cleaner_kthread(void *arg)
1468 {
1469 struct btrfs_root *root = arg;
1470
1471 do {
1472 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1473
1474 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1475 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1476 btrfs_run_delayed_iputs(root);
1477 btrfs_clean_old_snapshots(root);
1478 mutex_unlock(&root->fs_info->cleaner_mutex);
1479 btrfs_run_defrag_inodes(root->fs_info);
1480 }
1481
1482 if (freezing(current)) {
1483 refrigerator();
1484 } else {
1485 set_current_state(TASK_INTERRUPTIBLE);
1486 if (!kthread_should_stop())
1487 schedule();
1488 __set_current_state(TASK_RUNNING);
1489 }
1490 } while (!kthread_should_stop());
1491 return 0;
1492 }
1493
1494 static int transaction_kthread(void *arg)
1495 {
1496 struct btrfs_root *root = arg;
1497 struct btrfs_trans_handle *trans;
1498 struct btrfs_transaction *cur;
1499 u64 transid;
1500 unsigned long now;
1501 unsigned long delay;
1502 int ret;
1503
1504 do {
1505 delay = HZ * 30;
1506 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1507 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1508
1509 spin_lock(&root->fs_info->trans_lock);
1510 cur = root->fs_info->running_transaction;
1511 if (!cur) {
1512 spin_unlock(&root->fs_info->trans_lock);
1513 goto sleep;
1514 }
1515
1516 now = get_seconds();
1517 if (!cur->blocked &&
1518 (now < cur->start_time || now - cur->start_time < 30)) {
1519 spin_unlock(&root->fs_info->trans_lock);
1520 delay = HZ * 5;
1521 goto sleep;
1522 }
1523 transid = cur->transid;
1524 spin_unlock(&root->fs_info->trans_lock);
1525
1526 trans = btrfs_join_transaction(root);
1527 BUG_ON(IS_ERR(trans));
1528 if (transid == trans->transid) {
1529 ret = btrfs_commit_transaction(trans, root);
1530 BUG_ON(ret);
1531 } else {
1532 btrfs_end_transaction(trans, root);
1533 }
1534 sleep:
1535 wake_up_process(root->fs_info->cleaner_kthread);
1536 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1537
1538 if (freezing(current)) {
1539 refrigerator();
1540 } else {
1541 set_current_state(TASK_INTERRUPTIBLE);
1542 if (!kthread_should_stop() &&
1543 !btrfs_transaction_blocked(root->fs_info))
1544 schedule_timeout(delay);
1545 __set_current_state(TASK_RUNNING);
1546 }
1547 } while (!kthread_should_stop());
1548 return 0;
1549 }
1550
1551 struct btrfs_root *open_ctree(struct super_block *sb,
1552 struct btrfs_fs_devices *fs_devices,
1553 char *options)
1554 {
1555 u32 sectorsize;
1556 u32 nodesize;
1557 u32 leafsize;
1558 u32 blocksize;
1559 u32 stripesize;
1560 u64 generation;
1561 u64 features;
1562 struct btrfs_key location;
1563 struct buffer_head *bh;
1564 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1565 GFP_NOFS);
1566 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1567 GFP_NOFS);
1568 struct btrfs_root *tree_root = btrfs_sb(sb);
1569 struct btrfs_fs_info *fs_info = NULL;
1570 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1571 GFP_NOFS);
1572 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1573 GFP_NOFS);
1574 struct btrfs_root *log_tree_root;
1575
1576 int ret;
1577 int err = -EINVAL;
1578
1579 struct btrfs_super_block *disk_super;
1580
1581 if (!extent_root || !tree_root || !tree_root->fs_info ||
1582 !chunk_root || !dev_root || !csum_root) {
1583 err = -ENOMEM;
1584 goto fail;
1585 }
1586 fs_info = tree_root->fs_info;
1587
1588 ret = init_srcu_struct(&fs_info->subvol_srcu);
1589 if (ret) {
1590 err = ret;
1591 goto fail;
1592 }
1593
1594 ret = setup_bdi(fs_info, &fs_info->bdi);
1595 if (ret) {
1596 err = ret;
1597 goto fail_srcu;
1598 }
1599
1600 fs_info->btree_inode = new_inode(sb);
1601 if (!fs_info->btree_inode) {
1602 err = -ENOMEM;
1603 goto fail_bdi;
1604 }
1605
1606 fs_info->btree_inode->i_mapping->flags &= ~__GFP_FS;
1607
1608 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1609 INIT_LIST_HEAD(&fs_info->trans_list);
1610 INIT_LIST_HEAD(&fs_info->dead_roots);
1611 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1612 INIT_LIST_HEAD(&fs_info->hashers);
1613 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1614 INIT_LIST_HEAD(&fs_info->ordered_operations);
1615 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1616 spin_lock_init(&fs_info->delalloc_lock);
1617 spin_lock_init(&fs_info->trans_lock);
1618 spin_lock_init(&fs_info->ref_cache_lock);
1619 spin_lock_init(&fs_info->fs_roots_radix_lock);
1620 spin_lock_init(&fs_info->delayed_iput_lock);
1621 spin_lock_init(&fs_info->defrag_inodes_lock);
1622 mutex_init(&fs_info->reloc_mutex);
1623
1624 init_completion(&fs_info->kobj_unregister);
1625 fs_info->tree_root = tree_root;
1626 fs_info->extent_root = extent_root;
1627 fs_info->csum_root = csum_root;
1628 fs_info->chunk_root = chunk_root;
1629 fs_info->dev_root = dev_root;
1630 fs_info->fs_devices = fs_devices;
1631 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1632 INIT_LIST_HEAD(&fs_info->space_info);
1633 btrfs_mapping_init(&fs_info->mapping_tree);
1634 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1635 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1636 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1637 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1638 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1639 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1640 mutex_init(&fs_info->durable_block_rsv_mutex);
1641 atomic_set(&fs_info->nr_async_submits, 0);
1642 atomic_set(&fs_info->async_delalloc_pages, 0);
1643 atomic_set(&fs_info->async_submit_draining, 0);
1644 atomic_set(&fs_info->nr_async_bios, 0);
1645 atomic_set(&fs_info->defrag_running, 0);
1646 fs_info->sb = sb;
1647 fs_info->max_inline = 8192 * 1024;
1648 fs_info->metadata_ratio = 0;
1649 fs_info->defrag_inodes = RB_ROOT;
1650 fs_info->trans_no_join = 0;
1651
1652 fs_info->thread_pool_size = min_t(unsigned long,
1653 num_online_cpus() + 2, 8);
1654
1655 INIT_LIST_HEAD(&fs_info->ordered_extents);
1656 spin_lock_init(&fs_info->ordered_extent_lock);
1657 fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1658 GFP_NOFS);
1659 if (!fs_info->delayed_root) {
1660 err = -ENOMEM;
1661 goto fail_iput;
1662 }
1663 btrfs_init_delayed_root(fs_info->delayed_root);
1664
1665 mutex_init(&fs_info->scrub_lock);
1666 atomic_set(&fs_info->scrubs_running, 0);
1667 atomic_set(&fs_info->scrub_pause_req, 0);
1668 atomic_set(&fs_info->scrubs_paused, 0);
1669 atomic_set(&fs_info->scrub_cancel_req, 0);
1670 init_waitqueue_head(&fs_info->scrub_pause_wait);
1671 init_rwsem(&fs_info->scrub_super_lock);
1672 fs_info->scrub_workers_refcnt = 0;
1673
1674 sb->s_blocksize = 4096;
1675 sb->s_blocksize_bits = blksize_bits(4096);
1676 sb->s_bdi = &fs_info->bdi;
1677
1678 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1679 fs_info->btree_inode->i_nlink = 1;
1680 /*
1681 * we set the i_size on the btree inode to the max possible int.
1682 * the real end of the address space is determined by all of
1683 * the devices in the system
1684 */
1685 fs_info->btree_inode->i_size = OFFSET_MAX;
1686 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1687 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1688
1689 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1690 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1691 fs_info->btree_inode->i_mapping);
1692 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
1693
1694 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1695
1696 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1697 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1698 sizeof(struct btrfs_key));
1699 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1700 insert_inode_hash(fs_info->btree_inode);
1701
1702 spin_lock_init(&fs_info->block_group_cache_lock);
1703 fs_info->block_group_cache_tree = RB_ROOT;
1704
1705 extent_io_tree_init(&fs_info->freed_extents[0],
1706 fs_info->btree_inode->i_mapping);
1707 extent_io_tree_init(&fs_info->freed_extents[1],
1708 fs_info->btree_inode->i_mapping);
1709 fs_info->pinned_extents = &fs_info->freed_extents[0];
1710 fs_info->do_barriers = 1;
1711
1712
1713 mutex_init(&fs_info->ordered_operations_mutex);
1714 mutex_init(&fs_info->tree_log_mutex);
1715 mutex_init(&fs_info->chunk_mutex);
1716 mutex_init(&fs_info->transaction_kthread_mutex);
1717 mutex_init(&fs_info->cleaner_mutex);
1718 mutex_init(&fs_info->volume_mutex);
1719 init_rwsem(&fs_info->extent_commit_sem);
1720 init_rwsem(&fs_info->cleanup_work_sem);
1721 init_rwsem(&fs_info->subvol_sem);
1722
1723 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1724 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1725
1726 init_waitqueue_head(&fs_info->transaction_throttle);
1727 init_waitqueue_head(&fs_info->transaction_wait);
1728 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1729 init_waitqueue_head(&fs_info->async_submit_wait);
1730
1731 __setup_root(4096, 4096, 4096, 4096, tree_root,
1732 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1733
1734 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1735 if (!bh) {
1736 err = -EINVAL;
1737 goto fail_alloc;
1738 }
1739
1740 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1741 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1742 sizeof(fs_info->super_for_commit));
1743 brelse(bh);
1744
1745 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1746
1747 disk_super = &fs_info->super_copy;
1748 if (!btrfs_super_root(disk_super))
1749 goto fail_alloc;
1750
1751 /* check FS state, whether FS is broken. */
1752 fs_info->fs_state |= btrfs_super_flags(disk_super);
1753
1754 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1755
1756 /*
1757 * In the long term, we'll store the compression type in the super
1758 * block, and it'll be used for per file compression control.
1759 */
1760 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1761
1762 ret = btrfs_parse_options(tree_root, options);
1763 if (ret) {
1764 err = ret;
1765 goto fail_alloc;
1766 }
1767
1768 features = btrfs_super_incompat_flags(disk_super) &
1769 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1770 if (features) {
1771 printk(KERN_ERR "BTRFS: couldn't mount because of "
1772 "unsupported optional features (%Lx).\n",
1773 (unsigned long long)features);
1774 err = -EINVAL;
1775 goto fail_alloc;
1776 }
1777
1778 features = btrfs_super_incompat_flags(disk_super);
1779 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1780 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1781 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1782 btrfs_set_super_incompat_flags(disk_super, features);
1783
1784 features = btrfs_super_compat_ro_flags(disk_super) &
1785 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1786 if (!(sb->s_flags & MS_RDONLY) && features) {
1787 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1788 "unsupported option features (%Lx).\n",
1789 (unsigned long long)features);
1790 err = -EINVAL;
1791 goto fail_alloc;
1792 }
1793
1794 btrfs_init_workers(&fs_info->generic_worker,
1795 "genwork", 1, NULL);
1796
1797 btrfs_init_workers(&fs_info->workers, "worker",
1798 fs_info->thread_pool_size,
1799 &fs_info->generic_worker);
1800
1801 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1802 fs_info->thread_pool_size,
1803 &fs_info->generic_worker);
1804
1805 btrfs_init_workers(&fs_info->submit_workers, "submit",
1806 min_t(u64, fs_devices->num_devices,
1807 fs_info->thread_pool_size),
1808 &fs_info->generic_worker);
1809
1810 /* a higher idle thresh on the submit workers makes it much more
1811 * likely that bios will be send down in a sane order to the
1812 * devices
1813 */
1814 fs_info->submit_workers.idle_thresh = 64;
1815
1816 fs_info->workers.idle_thresh = 16;
1817 fs_info->workers.ordered = 1;
1818
1819 fs_info->delalloc_workers.idle_thresh = 2;
1820 fs_info->delalloc_workers.ordered = 1;
1821
1822 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1823 &fs_info->generic_worker);
1824 btrfs_init_workers(&fs_info->endio_workers, "endio",
1825 fs_info->thread_pool_size,
1826 &fs_info->generic_worker);
1827 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1828 fs_info->thread_pool_size,
1829 &fs_info->generic_worker);
1830 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1831 "endio-meta-write", fs_info->thread_pool_size,
1832 &fs_info->generic_worker);
1833 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1834 fs_info->thread_pool_size,
1835 &fs_info->generic_worker);
1836 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1837 1, &fs_info->generic_worker);
1838 btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
1839 fs_info->thread_pool_size,
1840 &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 btrfs_start_workers(&fs_info->delayed_workers, 1);
1863
1864 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1865 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1866 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1867
1868 nodesize = btrfs_super_nodesize(disk_super);
1869 leafsize = btrfs_super_leafsize(disk_super);
1870 sectorsize = btrfs_super_sectorsize(disk_super);
1871 stripesize = btrfs_super_stripesize(disk_super);
1872 tree_root->nodesize = nodesize;
1873 tree_root->leafsize = leafsize;
1874 tree_root->sectorsize = sectorsize;
1875 tree_root->stripesize = stripesize;
1876
1877 sb->s_blocksize = sectorsize;
1878 sb->s_blocksize_bits = blksize_bits(sectorsize);
1879
1880 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1881 sizeof(disk_super->magic))) {
1882 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1883 goto fail_sb_buffer;
1884 }
1885
1886 mutex_lock(&fs_info->chunk_mutex);
1887 ret = btrfs_read_sys_array(tree_root);
1888 mutex_unlock(&fs_info->chunk_mutex);
1889 if (ret) {
1890 printk(KERN_WARNING "btrfs: failed to read the system "
1891 "array on %s\n", sb->s_id);
1892 goto fail_sb_buffer;
1893 }
1894
1895 blocksize = btrfs_level_size(tree_root,
1896 btrfs_super_chunk_root_level(disk_super));
1897 generation = btrfs_super_chunk_root_generation(disk_super);
1898
1899 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1900 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1901
1902 chunk_root->node = read_tree_block(chunk_root,
1903 btrfs_super_chunk_root(disk_super),
1904 blocksize, generation);
1905 BUG_ON(!chunk_root->node);
1906 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1907 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1908 sb->s_id);
1909 goto fail_chunk_root;
1910 }
1911 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1912 chunk_root->commit_root = btrfs_root_node(chunk_root);
1913
1914 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1915 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1916 BTRFS_UUID_SIZE);
1917
1918 mutex_lock(&fs_info->chunk_mutex);
1919 ret = btrfs_read_chunk_tree(chunk_root);
1920 mutex_unlock(&fs_info->chunk_mutex);
1921 if (ret) {
1922 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1923 sb->s_id);
1924 goto fail_chunk_root;
1925 }
1926
1927 btrfs_close_extra_devices(fs_devices);
1928
1929 blocksize = btrfs_level_size(tree_root,
1930 btrfs_super_root_level(disk_super));
1931 generation = btrfs_super_generation(disk_super);
1932
1933 tree_root->node = read_tree_block(tree_root,
1934 btrfs_super_root(disk_super),
1935 blocksize, generation);
1936 if (!tree_root->node)
1937 goto fail_chunk_root;
1938 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1939 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1940 sb->s_id);
1941 goto fail_tree_root;
1942 }
1943 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1944 tree_root->commit_root = btrfs_root_node(tree_root);
1945
1946 ret = find_and_setup_root(tree_root, fs_info,
1947 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1948 if (ret)
1949 goto fail_tree_root;
1950 extent_root->track_dirty = 1;
1951
1952 ret = find_and_setup_root(tree_root, fs_info,
1953 BTRFS_DEV_TREE_OBJECTID, dev_root);
1954 if (ret)
1955 goto fail_extent_root;
1956 dev_root->track_dirty = 1;
1957
1958 ret = find_and_setup_root(tree_root, fs_info,
1959 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1960 if (ret)
1961 goto fail_dev_root;
1962
1963 csum_root->track_dirty = 1;
1964
1965 fs_info->generation = generation;
1966 fs_info->last_trans_committed = generation;
1967 fs_info->data_alloc_profile = (u64)-1;
1968 fs_info->metadata_alloc_profile = (u64)-1;
1969 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1970
1971 ret = btrfs_init_space_info(fs_info);
1972 if (ret) {
1973 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
1974 goto fail_block_groups;
1975 }
1976
1977 ret = btrfs_read_block_groups(extent_root);
1978 if (ret) {
1979 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1980 goto fail_block_groups;
1981 }
1982
1983 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1984 "btrfs-cleaner");
1985 if (IS_ERR(fs_info->cleaner_kthread))
1986 goto fail_block_groups;
1987
1988 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1989 tree_root,
1990 "btrfs-transaction");
1991 if (IS_ERR(fs_info->transaction_kthread))
1992 goto fail_cleaner;
1993
1994 if (!btrfs_test_opt(tree_root, SSD) &&
1995 !btrfs_test_opt(tree_root, NOSSD) &&
1996 !fs_info->fs_devices->rotating) {
1997 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1998 "mode\n");
1999 btrfs_set_opt(fs_info->mount_opt, SSD);
2000 }
2001
2002 /* do not make disk changes in broken FS */
2003 if (btrfs_super_log_root(disk_super) != 0 &&
2004 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2005 u64 bytenr = btrfs_super_log_root(disk_super);
2006
2007 if (fs_devices->rw_devices == 0) {
2008 printk(KERN_WARNING "Btrfs log replay required "
2009 "on RO media\n");
2010 err = -EIO;
2011 goto fail_trans_kthread;
2012 }
2013 blocksize =
2014 btrfs_level_size(tree_root,
2015 btrfs_super_log_root_level(disk_super));
2016
2017 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2018 if (!log_tree_root) {
2019 err = -ENOMEM;
2020 goto fail_trans_kthread;
2021 }
2022
2023 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2024 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2025
2026 log_tree_root->node = read_tree_block(tree_root, bytenr,
2027 blocksize,
2028 generation + 1);
2029 ret = btrfs_recover_log_trees(log_tree_root);
2030 BUG_ON(ret);
2031
2032 if (sb->s_flags & MS_RDONLY) {
2033 ret = btrfs_commit_super(tree_root);
2034 BUG_ON(ret);
2035 }
2036 }
2037
2038 ret = btrfs_find_orphan_roots(tree_root);
2039 BUG_ON(ret);
2040
2041 if (!(sb->s_flags & MS_RDONLY)) {
2042 ret = btrfs_cleanup_fs_roots(fs_info);
2043 BUG_ON(ret);
2044
2045 ret = btrfs_recover_relocation(tree_root);
2046 if (ret < 0) {
2047 printk(KERN_WARNING
2048 "btrfs: failed to recover relocation\n");
2049 err = -EINVAL;
2050 goto fail_trans_kthread;
2051 }
2052 }
2053
2054 location.objectid = BTRFS_FS_TREE_OBJECTID;
2055 location.type = BTRFS_ROOT_ITEM_KEY;
2056 location.offset = (u64)-1;
2057
2058 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2059 if (!fs_info->fs_root)
2060 goto fail_trans_kthread;
2061 if (IS_ERR(fs_info->fs_root)) {
2062 err = PTR_ERR(fs_info->fs_root);
2063 goto fail_trans_kthread;
2064 }
2065
2066 if (!(sb->s_flags & MS_RDONLY)) {
2067 down_read(&fs_info->cleanup_work_sem);
2068 err = btrfs_orphan_cleanup(fs_info->fs_root);
2069 if (!err)
2070 err = btrfs_orphan_cleanup(fs_info->tree_root);
2071 up_read(&fs_info->cleanup_work_sem);
2072 if (err) {
2073 close_ctree(tree_root);
2074 return ERR_PTR(err);
2075 }
2076 }
2077
2078 return tree_root;
2079
2080 fail_trans_kthread:
2081 kthread_stop(fs_info->transaction_kthread);
2082 fail_cleaner:
2083 kthread_stop(fs_info->cleaner_kthread);
2084
2085 /*
2086 * make sure we're done with the btree inode before we stop our
2087 * kthreads
2088 */
2089 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2090 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2091
2092 fail_block_groups:
2093 btrfs_free_block_groups(fs_info);
2094 free_extent_buffer(csum_root->node);
2095 free_extent_buffer(csum_root->commit_root);
2096 fail_dev_root:
2097 free_extent_buffer(dev_root->node);
2098 free_extent_buffer(dev_root->commit_root);
2099 fail_extent_root:
2100 free_extent_buffer(extent_root->node);
2101 free_extent_buffer(extent_root->commit_root);
2102 fail_tree_root:
2103 free_extent_buffer(tree_root->node);
2104 free_extent_buffer(tree_root->commit_root);
2105 fail_chunk_root:
2106 free_extent_buffer(chunk_root->node);
2107 free_extent_buffer(chunk_root->commit_root);
2108 fail_sb_buffer:
2109 btrfs_stop_workers(&fs_info->generic_worker);
2110 btrfs_stop_workers(&fs_info->fixup_workers);
2111 btrfs_stop_workers(&fs_info->delalloc_workers);
2112 btrfs_stop_workers(&fs_info->workers);
2113 btrfs_stop_workers(&fs_info->endio_workers);
2114 btrfs_stop_workers(&fs_info->endio_meta_workers);
2115 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2116 btrfs_stop_workers(&fs_info->endio_write_workers);
2117 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2118 btrfs_stop_workers(&fs_info->submit_workers);
2119 btrfs_stop_workers(&fs_info->delayed_workers);
2120 fail_alloc:
2121 kfree(fs_info->delayed_root);
2122 fail_iput:
2123 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2124 iput(fs_info->btree_inode);
2125
2126 btrfs_close_devices(fs_info->fs_devices);
2127 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2128 fail_bdi:
2129 bdi_destroy(&fs_info->bdi);
2130 fail_srcu:
2131 cleanup_srcu_struct(&fs_info->subvol_srcu);
2132 fail:
2133 kfree(extent_root);
2134 kfree(tree_root);
2135 kfree(fs_info);
2136 kfree(chunk_root);
2137 kfree(dev_root);
2138 kfree(csum_root);
2139 return ERR_PTR(err);
2140 }
2141
2142 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2143 {
2144 char b[BDEVNAME_SIZE];
2145
2146 if (uptodate) {
2147 set_buffer_uptodate(bh);
2148 } else {
2149 printk_ratelimited(KERN_WARNING "lost page write due to "
2150 "I/O error on %s\n",
2151 bdevname(bh->b_bdev, b));
2152 /* note, we dont' set_buffer_write_io_error because we have
2153 * our own ways of dealing with the IO errors
2154 */
2155 clear_buffer_uptodate(bh);
2156 }
2157 unlock_buffer(bh);
2158 put_bh(bh);
2159 }
2160
2161 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2162 {
2163 struct buffer_head *bh;
2164 struct buffer_head *latest = NULL;
2165 struct btrfs_super_block *super;
2166 int i;
2167 u64 transid = 0;
2168 u64 bytenr;
2169
2170 /* we would like to check all the supers, but that would make
2171 * a btrfs mount succeed after a mkfs from a different FS.
2172 * So, we need to add a special mount option to scan for
2173 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2174 */
2175 for (i = 0; i < 1; i++) {
2176 bytenr = btrfs_sb_offset(i);
2177 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2178 break;
2179 bh = __bread(bdev, bytenr / 4096, 4096);
2180 if (!bh)
2181 continue;
2182
2183 super = (struct btrfs_super_block *)bh->b_data;
2184 if (btrfs_super_bytenr(super) != bytenr ||
2185 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2186 sizeof(super->magic))) {
2187 brelse(bh);
2188 continue;
2189 }
2190
2191 if (!latest || btrfs_super_generation(super) > transid) {
2192 brelse(latest);
2193 latest = bh;
2194 transid = btrfs_super_generation(super);
2195 } else {
2196 brelse(bh);
2197 }
2198 }
2199 return latest;
2200 }
2201
2202 /*
2203 * this should be called twice, once with wait == 0 and
2204 * once with wait == 1. When wait == 0 is done, all the buffer heads
2205 * we write are pinned.
2206 *
2207 * They are released when wait == 1 is done.
2208 * max_mirrors must be the same for both runs, and it indicates how
2209 * many supers on this one device should be written.
2210 *
2211 * max_mirrors == 0 means to write them all.
2212 */
2213 static int write_dev_supers(struct btrfs_device *device,
2214 struct btrfs_super_block *sb,
2215 int do_barriers, int wait, int max_mirrors)
2216 {
2217 struct buffer_head *bh;
2218 int i;
2219 int ret;
2220 int errors = 0;
2221 u32 crc;
2222 u64 bytenr;
2223 int last_barrier = 0;
2224
2225 if (max_mirrors == 0)
2226 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2227
2228 /* make sure only the last submit_bh does a barrier */
2229 if (do_barriers) {
2230 for (i = 0; i < max_mirrors; i++) {
2231 bytenr = btrfs_sb_offset(i);
2232 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2233 device->total_bytes)
2234 break;
2235 last_barrier = i;
2236 }
2237 }
2238
2239 for (i = 0; i < max_mirrors; i++) {
2240 bytenr = btrfs_sb_offset(i);
2241 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2242 break;
2243
2244 if (wait) {
2245 bh = __find_get_block(device->bdev, bytenr / 4096,
2246 BTRFS_SUPER_INFO_SIZE);
2247 BUG_ON(!bh);
2248 wait_on_buffer(bh);
2249 if (!buffer_uptodate(bh))
2250 errors++;
2251
2252 /* drop our reference */
2253 brelse(bh);
2254
2255 /* drop the reference from the wait == 0 run */
2256 brelse(bh);
2257 continue;
2258 } else {
2259 btrfs_set_super_bytenr(sb, bytenr);
2260
2261 crc = ~(u32)0;
2262 crc = btrfs_csum_data(NULL, (char *)sb +
2263 BTRFS_CSUM_SIZE, crc,
2264 BTRFS_SUPER_INFO_SIZE -
2265 BTRFS_CSUM_SIZE);
2266 btrfs_csum_final(crc, sb->csum);
2267
2268 /*
2269 * one reference for us, and we leave it for the
2270 * caller
2271 */
2272 bh = __getblk(device->bdev, bytenr / 4096,
2273 BTRFS_SUPER_INFO_SIZE);
2274 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2275
2276 /* one reference for submit_bh */
2277 get_bh(bh);
2278
2279 set_buffer_uptodate(bh);
2280 lock_buffer(bh);
2281 bh->b_end_io = btrfs_end_buffer_write_sync;
2282 }
2283
2284 if (i == last_barrier && do_barriers)
2285 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2286 else
2287 ret = submit_bh(WRITE_SYNC, bh);
2288
2289 if (ret)
2290 errors++;
2291 }
2292 return errors < i ? 0 : -1;
2293 }
2294
2295 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2296 {
2297 struct list_head *head;
2298 struct btrfs_device *dev;
2299 struct btrfs_super_block *sb;
2300 struct btrfs_dev_item *dev_item;
2301 int ret;
2302 int do_barriers;
2303 int max_errors;
2304 int total_errors = 0;
2305 u64 flags;
2306
2307 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2308 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2309
2310 sb = &root->fs_info->super_for_commit;
2311 dev_item = &sb->dev_item;
2312
2313 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2314 head = &root->fs_info->fs_devices->devices;
2315 list_for_each_entry_rcu(dev, head, dev_list) {
2316 if (!dev->bdev) {
2317 total_errors++;
2318 continue;
2319 }
2320 if (!dev->in_fs_metadata || !dev->writeable)
2321 continue;
2322
2323 btrfs_set_stack_device_generation(dev_item, 0);
2324 btrfs_set_stack_device_type(dev_item, dev->type);
2325 btrfs_set_stack_device_id(dev_item, dev->devid);
2326 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2327 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2328 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2329 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2330 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2331 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2332 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2333
2334 flags = btrfs_super_flags(sb);
2335 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2336
2337 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2338 if (ret)
2339 total_errors++;
2340 }
2341 if (total_errors > max_errors) {
2342 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2343 total_errors);
2344 BUG();
2345 }
2346
2347 total_errors = 0;
2348 list_for_each_entry_rcu(dev, head, dev_list) {
2349 if (!dev->bdev)
2350 continue;
2351 if (!dev->in_fs_metadata || !dev->writeable)
2352 continue;
2353
2354 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2355 if (ret)
2356 total_errors++;
2357 }
2358 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2359 if (total_errors > max_errors) {
2360 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2361 total_errors);
2362 BUG();
2363 }
2364 return 0;
2365 }
2366
2367 int write_ctree_super(struct btrfs_trans_handle *trans,
2368 struct btrfs_root *root, int max_mirrors)
2369 {
2370 int ret;
2371
2372 ret = write_all_supers(root, max_mirrors);
2373 return ret;
2374 }
2375
2376 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2377 {
2378 spin_lock(&fs_info->fs_roots_radix_lock);
2379 radix_tree_delete(&fs_info->fs_roots_radix,
2380 (unsigned long)root->root_key.objectid);
2381 spin_unlock(&fs_info->fs_roots_radix_lock);
2382
2383 if (btrfs_root_refs(&root->root_item) == 0)
2384 synchronize_srcu(&fs_info->subvol_srcu);
2385
2386 __btrfs_remove_free_space_cache(root->free_ino_pinned);
2387 __btrfs_remove_free_space_cache(root->free_ino_ctl);
2388 free_fs_root(root);
2389 return 0;
2390 }
2391
2392 static void free_fs_root(struct btrfs_root *root)
2393 {
2394 iput(root->cache_inode);
2395 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2396 if (root->anon_super.s_dev) {
2397 down_write(&root->anon_super.s_umount);
2398 kill_anon_super(&root->anon_super);
2399 }
2400 free_extent_buffer(root->node);
2401 free_extent_buffer(root->commit_root);
2402 kfree(root->free_ino_ctl);
2403 kfree(root->free_ino_pinned);
2404 kfree(root->name);
2405 kfree(root);
2406 }
2407
2408 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2409 {
2410 int ret;
2411 struct btrfs_root *gang[8];
2412 int i;
2413
2414 while (!list_empty(&fs_info->dead_roots)) {
2415 gang[0] = list_entry(fs_info->dead_roots.next,
2416 struct btrfs_root, root_list);
2417 list_del(&gang[0]->root_list);
2418
2419 if (gang[0]->in_radix) {
2420 btrfs_free_fs_root(fs_info, gang[0]);
2421 } else {
2422 free_extent_buffer(gang[0]->node);
2423 free_extent_buffer(gang[0]->commit_root);
2424 kfree(gang[0]);
2425 }
2426 }
2427
2428 while (1) {
2429 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2430 (void **)gang, 0,
2431 ARRAY_SIZE(gang));
2432 if (!ret)
2433 break;
2434 for (i = 0; i < ret; i++)
2435 btrfs_free_fs_root(fs_info, gang[i]);
2436 }
2437 return 0;
2438 }
2439
2440 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2441 {
2442 u64 root_objectid = 0;
2443 struct btrfs_root *gang[8];
2444 int i;
2445 int ret;
2446
2447 while (1) {
2448 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2449 (void **)gang, root_objectid,
2450 ARRAY_SIZE(gang));
2451 if (!ret)
2452 break;
2453
2454 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2455 for (i = 0; i < ret; i++) {
2456 int err;
2457
2458 root_objectid = gang[i]->root_key.objectid;
2459 err = btrfs_orphan_cleanup(gang[i]);
2460 if (err)
2461 return err;
2462 }
2463 root_objectid++;
2464 }
2465 return 0;
2466 }
2467
2468 int btrfs_commit_super(struct btrfs_root *root)
2469 {
2470 struct btrfs_trans_handle *trans;
2471 int ret;
2472
2473 mutex_lock(&root->fs_info->cleaner_mutex);
2474 btrfs_run_delayed_iputs(root);
2475 btrfs_clean_old_snapshots(root);
2476 mutex_unlock(&root->fs_info->cleaner_mutex);
2477
2478 /* wait until ongoing cleanup work done */
2479 down_write(&root->fs_info->cleanup_work_sem);
2480 up_write(&root->fs_info->cleanup_work_sem);
2481
2482 trans = btrfs_join_transaction(root);
2483 if (IS_ERR(trans))
2484 return PTR_ERR(trans);
2485 ret = btrfs_commit_transaction(trans, root);
2486 BUG_ON(ret);
2487 /* run commit again to drop the original snapshot */
2488 trans = btrfs_join_transaction(root);
2489 if (IS_ERR(trans))
2490 return PTR_ERR(trans);
2491 btrfs_commit_transaction(trans, root);
2492 ret = btrfs_write_and_wait_transaction(NULL, root);
2493 BUG_ON(ret);
2494
2495 ret = write_ctree_super(NULL, root, 0);
2496 return ret;
2497 }
2498
2499 int close_ctree(struct btrfs_root *root)
2500 {
2501 struct btrfs_fs_info *fs_info = root->fs_info;
2502 int ret;
2503
2504 fs_info->closing = 1;
2505 smp_mb();
2506
2507 btrfs_scrub_cancel(root);
2508
2509 /* wait for any defraggers to finish */
2510 wait_event(fs_info->transaction_wait,
2511 (atomic_read(&fs_info->defrag_running) == 0));
2512
2513 /* clear out the rbtree of defraggable inodes */
2514 btrfs_run_defrag_inodes(root->fs_info);
2515
2516 btrfs_put_block_group_cache(fs_info);
2517
2518 /*
2519 * Here come 2 situations when btrfs is broken to flip readonly:
2520 *
2521 * 1. when btrfs flips readonly somewhere else before
2522 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2523 * and btrfs will skip to write sb directly to keep
2524 * ERROR state on disk.
2525 *
2526 * 2. when btrfs flips readonly just in btrfs_commit_super,
2527 * and in such case, btrfs cannot write sb via btrfs_commit_super,
2528 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2529 * btrfs will cleanup all FS resources first and write sb then.
2530 */
2531 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2532 ret = btrfs_commit_super(root);
2533 if (ret)
2534 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2535 }
2536
2537 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2538 ret = btrfs_error_commit_super(root);
2539 if (ret)
2540 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2541 }
2542
2543 kthread_stop(root->fs_info->transaction_kthread);
2544 kthread_stop(root->fs_info->cleaner_kthread);
2545
2546 fs_info->closing = 2;
2547 smp_mb();
2548
2549 if (fs_info->delalloc_bytes) {
2550 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2551 (unsigned long long)fs_info->delalloc_bytes);
2552 }
2553 if (fs_info->total_ref_cache_size) {
2554 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2555 (unsigned long long)fs_info->total_ref_cache_size);
2556 }
2557
2558 free_extent_buffer(fs_info->extent_root->node);
2559 free_extent_buffer(fs_info->extent_root->commit_root);
2560 free_extent_buffer(fs_info->tree_root->node);
2561 free_extent_buffer(fs_info->tree_root->commit_root);
2562 free_extent_buffer(root->fs_info->chunk_root->node);
2563 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2564 free_extent_buffer(root->fs_info->dev_root->node);
2565 free_extent_buffer(root->fs_info->dev_root->commit_root);
2566 free_extent_buffer(root->fs_info->csum_root->node);
2567 free_extent_buffer(root->fs_info->csum_root->commit_root);
2568
2569 btrfs_free_block_groups(root->fs_info);
2570
2571 del_fs_roots(fs_info);
2572
2573 iput(fs_info->btree_inode);
2574 kfree(fs_info->delayed_root);
2575
2576 btrfs_stop_workers(&fs_info->generic_worker);
2577 btrfs_stop_workers(&fs_info->fixup_workers);
2578 btrfs_stop_workers(&fs_info->delalloc_workers);
2579 btrfs_stop_workers(&fs_info->workers);
2580 btrfs_stop_workers(&fs_info->endio_workers);
2581 btrfs_stop_workers(&fs_info->endio_meta_workers);
2582 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2583 btrfs_stop_workers(&fs_info->endio_write_workers);
2584 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2585 btrfs_stop_workers(&fs_info->submit_workers);
2586 btrfs_stop_workers(&fs_info->delayed_workers);
2587
2588 btrfs_close_devices(fs_info->fs_devices);
2589 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2590
2591 bdi_destroy(&fs_info->bdi);
2592 cleanup_srcu_struct(&fs_info->subvol_srcu);
2593
2594 kfree(fs_info->extent_root);
2595 kfree(fs_info->tree_root);
2596 kfree(fs_info->chunk_root);
2597 kfree(fs_info->dev_root);
2598 kfree(fs_info->csum_root);
2599 kfree(fs_info);
2600
2601 return 0;
2602 }
2603
2604 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2605 {
2606 int ret;
2607 struct inode *btree_inode = buf->first_page->mapping->host;
2608
2609 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2610 NULL);
2611 if (!ret)
2612 return ret;
2613
2614 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2615 parent_transid);
2616 return !ret;
2617 }
2618
2619 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2620 {
2621 struct inode *btree_inode = buf->first_page->mapping->host;
2622 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2623 buf);
2624 }
2625
2626 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2627 {
2628 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2629 u64 transid = btrfs_header_generation(buf);
2630 struct inode *btree_inode = root->fs_info->btree_inode;
2631 int was_dirty;
2632
2633 btrfs_assert_tree_locked(buf);
2634 if (transid != root->fs_info->generation) {
2635 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2636 "found %llu running %llu\n",
2637 (unsigned long long)buf->start,
2638 (unsigned long long)transid,
2639 (unsigned long long)root->fs_info->generation);
2640 WARN_ON(1);
2641 }
2642 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2643 buf);
2644 if (!was_dirty) {
2645 spin_lock(&root->fs_info->delalloc_lock);
2646 root->fs_info->dirty_metadata_bytes += buf->len;
2647 spin_unlock(&root->fs_info->delalloc_lock);
2648 }
2649 }
2650
2651 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2652 {
2653 /*
2654 * looks as though older kernels can get into trouble with
2655 * this code, they end up stuck in balance_dirty_pages forever
2656 */
2657 u64 num_dirty;
2658 unsigned long thresh = 32 * 1024 * 1024;
2659
2660 if (current->flags & PF_MEMALLOC)
2661 return;
2662
2663 btrfs_balance_delayed_items(root);
2664
2665 num_dirty = root->fs_info->dirty_metadata_bytes;
2666
2667 if (num_dirty > thresh) {
2668 balance_dirty_pages_ratelimited_nr(
2669 root->fs_info->btree_inode->i_mapping, 1);
2670 }
2671 return;
2672 }
2673
2674 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2675 {
2676 /*
2677 * looks as though older kernels can get into trouble with
2678 * this code, they end up stuck in balance_dirty_pages forever
2679 */
2680 u64 num_dirty;
2681 unsigned long thresh = 32 * 1024 * 1024;
2682
2683 if (current->flags & PF_MEMALLOC)
2684 return;
2685
2686 num_dirty = root->fs_info->dirty_metadata_bytes;
2687
2688 if (num_dirty > thresh) {
2689 balance_dirty_pages_ratelimited_nr(
2690 root->fs_info->btree_inode->i_mapping, 1);
2691 }
2692 return;
2693 }
2694
2695 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2696 {
2697 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2698 int ret;
2699 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2700 if (ret == 0)
2701 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2702 return ret;
2703 }
2704
2705 int btree_lock_page_hook(struct page *page)
2706 {
2707 struct inode *inode = page->mapping->host;
2708 struct btrfs_root *root = BTRFS_I(inode)->root;
2709 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2710 struct extent_buffer *eb;
2711 unsigned long len;
2712 u64 bytenr = page_offset(page);
2713
2714 if (page->private == EXTENT_PAGE_PRIVATE)
2715 goto out;
2716
2717 len = page->private >> 2;
2718 eb = find_extent_buffer(io_tree, bytenr, len);
2719 if (!eb)
2720 goto out;
2721
2722 btrfs_tree_lock(eb);
2723 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2724
2725 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2726 spin_lock(&root->fs_info->delalloc_lock);
2727 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2728 root->fs_info->dirty_metadata_bytes -= eb->len;
2729 else
2730 WARN_ON(1);
2731 spin_unlock(&root->fs_info->delalloc_lock);
2732 }
2733
2734 btrfs_tree_unlock(eb);
2735 free_extent_buffer(eb);
2736 out:
2737 lock_page(page);
2738 return 0;
2739 }
2740
2741 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2742 int read_only)
2743 {
2744 if (read_only)
2745 return;
2746
2747 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2748 printk(KERN_WARNING "warning: mount fs with errors, "
2749 "running btrfsck is recommended\n");
2750 }
2751
2752 int btrfs_error_commit_super(struct btrfs_root *root)
2753 {
2754 int ret;
2755
2756 mutex_lock(&root->fs_info->cleaner_mutex);
2757 btrfs_run_delayed_iputs(root);
2758 mutex_unlock(&root->fs_info->cleaner_mutex);
2759
2760 down_write(&root->fs_info->cleanup_work_sem);
2761 up_write(&root->fs_info->cleanup_work_sem);
2762
2763 /* cleanup FS via transaction */
2764 btrfs_cleanup_transaction(root);
2765
2766 ret = write_ctree_super(NULL, root, 0);
2767
2768 return ret;
2769 }
2770
2771 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2772 {
2773 struct btrfs_inode *btrfs_inode;
2774 struct list_head splice;
2775
2776 INIT_LIST_HEAD(&splice);
2777
2778 mutex_lock(&root->fs_info->ordered_operations_mutex);
2779 spin_lock(&root->fs_info->ordered_extent_lock);
2780
2781 list_splice_init(&root->fs_info->ordered_operations, &splice);
2782 while (!list_empty(&splice)) {
2783 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2784 ordered_operations);
2785
2786 list_del_init(&btrfs_inode->ordered_operations);
2787
2788 btrfs_invalidate_inodes(btrfs_inode->root);
2789 }
2790
2791 spin_unlock(&root->fs_info->ordered_extent_lock);
2792 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2793
2794 return 0;
2795 }
2796
2797 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2798 {
2799 struct list_head splice;
2800 struct btrfs_ordered_extent *ordered;
2801 struct inode *inode;
2802
2803 INIT_LIST_HEAD(&splice);
2804
2805 spin_lock(&root->fs_info->ordered_extent_lock);
2806
2807 list_splice_init(&root->fs_info->ordered_extents, &splice);
2808 while (!list_empty(&splice)) {
2809 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2810 root_extent_list);
2811
2812 list_del_init(&ordered->root_extent_list);
2813 atomic_inc(&ordered->refs);
2814
2815 /* the inode may be getting freed (in sys_unlink path). */
2816 inode = igrab(ordered->inode);
2817
2818 spin_unlock(&root->fs_info->ordered_extent_lock);
2819 if (inode)
2820 iput(inode);
2821
2822 atomic_set(&ordered->refs, 1);
2823 btrfs_put_ordered_extent(ordered);
2824
2825 spin_lock(&root->fs_info->ordered_extent_lock);
2826 }
2827
2828 spin_unlock(&root->fs_info->ordered_extent_lock);
2829
2830 return 0;
2831 }
2832
2833 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2834 struct btrfs_root *root)
2835 {
2836 struct rb_node *node;
2837 struct btrfs_delayed_ref_root *delayed_refs;
2838 struct btrfs_delayed_ref_node *ref;
2839 int ret = 0;
2840
2841 delayed_refs = &trans->delayed_refs;
2842
2843 spin_lock(&delayed_refs->lock);
2844 if (delayed_refs->num_entries == 0) {
2845 spin_unlock(&delayed_refs->lock);
2846 printk(KERN_INFO "delayed_refs has NO entry\n");
2847 return ret;
2848 }
2849
2850 node = rb_first(&delayed_refs->root);
2851 while (node) {
2852 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2853 node = rb_next(node);
2854
2855 ref->in_tree = 0;
2856 rb_erase(&ref->rb_node, &delayed_refs->root);
2857 delayed_refs->num_entries--;
2858
2859 atomic_set(&ref->refs, 1);
2860 if (btrfs_delayed_ref_is_head(ref)) {
2861 struct btrfs_delayed_ref_head *head;
2862
2863 head = btrfs_delayed_node_to_head(ref);
2864 mutex_lock(&head->mutex);
2865 kfree(head->extent_op);
2866 delayed_refs->num_heads--;
2867 if (list_empty(&head->cluster))
2868 delayed_refs->num_heads_ready--;
2869 list_del_init(&head->cluster);
2870 mutex_unlock(&head->mutex);
2871 }
2872
2873 spin_unlock(&delayed_refs->lock);
2874 btrfs_put_delayed_ref(ref);
2875
2876 cond_resched();
2877 spin_lock(&delayed_refs->lock);
2878 }
2879
2880 spin_unlock(&delayed_refs->lock);
2881
2882 return ret;
2883 }
2884
2885 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2886 {
2887 struct btrfs_pending_snapshot *snapshot;
2888 struct list_head splice;
2889
2890 INIT_LIST_HEAD(&splice);
2891
2892 list_splice_init(&t->pending_snapshots, &splice);
2893
2894 while (!list_empty(&splice)) {
2895 snapshot = list_entry(splice.next,
2896 struct btrfs_pending_snapshot,
2897 list);
2898
2899 list_del_init(&snapshot->list);
2900
2901 kfree(snapshot);
2902 }
2903
2904 return 0;
2905 }
2906
2907 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2908 {
2909 struct btrfs_inode *btrfs_inode;
2910 struct list_head splice;
2911
2912 INIT_LIST_HEAD(&splice);
2913
2914 spin_lock(&root->fs_info->delalloc_lock);
2915 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2916
2917 while (!list_empty(&splice)) {
2918 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2919 delalloc_inodes);
2920
2921 list_del_init(&btrfs_inode->delalloc_inodes);
2922
2923 btrfs_invalidate_inodes(btrfs_inode->root);
2924 }
2925
2926 spin_unlock(&root->fs_info->delalloc_lock);
2927
2928 return 0;
2929 }
2930
2931 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2932 struct extent_io_tree *dirty_pages,
2933 int mark)
2934 {
2935 int ret;
2936 struct page *page;
2937 struct inode *btree_inode = root->fs_info->btree_inode;
2938 struct extent_buffer *eb;
2939 u64 start = 0;
2940 u64 end;
2941 u64 offset;
2942 unsigned long index;
2943
2944 while (1) {
2945 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2946 mark);
2947 if (ret)
2948 break;
2949
2950 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2951 while (start <= end) {
2952 index = start >> PAGE_CACHE_SHIFT;
2953 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2954 page = find_get_page(btree_inode->i_mapping, index);
2955 if (!page)
2956 continue;
2957 offset = page_offset(page);
2958
2959 spin_lock(&dirty_pages->buffer_lock);
2960 eb = radix_tree_lookup(
2961 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2962 offset >> PAGE_CACHE_SHIFT);
2963 spin_unlock(&dirty_pages->buffer_lock);
2964 if (eb) {
2965 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2966 &eb->bflags);
2967 atomic_set(&eb->refs, 1);
2968 }
2969 if (PageWriteback(page))
2970 end_page_writeback(page);
2971
2972 lock_page(page);
2973 if (PageDirty(page)) {
2974 clear_page_dirty_for_io(page);
2975 spin_lock_irq(&page->mapping->tree_lock);
2976 radix_tree_tag_clear(&page->mapping->page_tree,
2977 page_index(page),
2978 PAGECACHE_TAG_DIRTY);
2979 spin_unlock_irq(&page->mapping->tree_lock);
2980 }
2981
2982 page->mapping->a_ops->invalidatepage(page, 0);
2983 unlock_page(page);
2984 }
2985 }
2986
2987 return ret;
2988 }
2989
2990 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
2991 struct extent_io_tree *pinned_extents)
2992 {
2993 struct extent_io_tree *unpin;
2994 u64 start;
2995 u64 end;
2996 int ret;
2997
2998 unpin = pinned_extents;
2999 while (1) {
3000 ret = find_first_extent_bit(unpin, 0, &start, &end,
3001 EXTENT_DIRTY);
3002 if (ret)
3003 break;
3004
3005 /* opt_discard */
3006 if (btrfs_test_opt(root, DISCARD))
3007 ret = btrfs_error_discard_extent(root, start,
3008 end + 1 - start,
3009 NULL);
3010
3011 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3012 btrfs_error_unpin_extent_range(root, start, end);
3013 cond_resched();
3014 }
3015
3016 return 0;
3017 }
3018
3019 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3020 {
3021 struct btrfs_transaction *t;
3022 LIST_HEAD(list);
3023
3024 WARN_ON(1);
3025
3026 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3027
3028 spin_lock(&root->fs_info->trans_lock);
3029 list_splice_init(&root->fs_info->trans_list, &list);
3030 root->fs_info->trans_no_join = 1;
3031 spin_unlock(&root->fs_info->trans_lock);
3032
3033 while (!list_empty(&list)) {
3034 t = list_entry(list.next, struct btrfs_transaction, list);
3035 if (!t)
3036 break;
3037
3038 btrfs_destroy_ordered_operations(root);
3039
3040 btrfs_destroy_ordered_extents(root);
3041
3042 btrfs_destroy_delayed_refs(t, root);
3043
3044 btrfs_block_rsv_release(root,
3045 &root->fs_info->trans_block_rsv,
3046 t->dirty_pages.dirty_bytes);
3047
3048 /* FIXME: cleanup wait for commit */
3049 t->in_commit = 1;
3050 t->blocked = 1;
3051 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3052 wake_up(&root->fs_info->transaction_blocked_wait);
3053
3054 t->blocked = 0;
3055 if (waitqueue_active(&root->fs_info->transaction_wait))
3056 wake_up(&root->fs_info->transaction_wait);
3057
3058 t->commit_done = 1;
3059 if (waitqueue_active(&t->commit_wait))
3060 wake_up(&t->commit_wait);
3061
3062 btrfs_destroy_pending_snapshots(t);
3063
3064 btrfs_destroy_delalloc_inodes(root);
3065
3066 spin_lock(&root->fs_info->trans_lock);
3067 root->fs_info->running_transaction = NULL;
3068 spin_unlock(&root->fs_info->trans_lock);
3069
3070 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3071 EXTENT_DIRTY);
3072
3073 btrfs_destroy_pinned_extent(root,
3074 root->fs_info->pinned_extents);
3075
3076 atomic_set(&t->use_count, 0);
3077 list_del_init(&t->list);
3078 memset(t, 0, sizeof(*t));
3079 kmem_cache_free(btrfs_transaction_cachep, t);
3080 }
3081
3082 spin_lock(&root->fs_info->trans_lock);
3083 root->fs_info->trans_no_join = 0;
3084 spin_unlock(&root->fs_info->trans_lock);
3085 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3086
3087 return 0;
3088 }
3089
3090 static struct extent_io_ops btree_extent_io_ops = {
3091 .write_cache_pages_lock_hook = btree_lock_page_hook,
3092 .readpage_end_io_hook = btree_readpage_end_io_hook,
3093 .submit_bio_hook = btree_submit_bio_hook,
3094 /* note we're sharing with inode.c for the merge bio hook */
3095 .merge_bio_hook = btrfs_merge_bio_hook,
3096 };
linux-next