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btrfs: make functions static when possible
[deliverable/linux.git] / fs / btrfs / disk-io.c
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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 <asm/unaligned.h>
33#include "compat.h"
34#include "ctree.h"
35#include "disk-io.h"
36#include "transaction.h"
37#include "btrfs_inode.h"
38#include "volumes.h"
39#include "print-tree.h"
40#include "async-thread.h"
41#include "locking.h"
42#include "tree-log.h"
43#include "free-space-cache.h"
44
45static struct extent_io_ops btree_extent_io_ops;
46static void end_workqueue_fn(struct btrfs_work *work);
47static void free_fs_root(struct btrfs_root *root);
48static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
49 int read_only);
50static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
51static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
52static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
53 struct btrfs_root *root);
54static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
55static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
56static int btrfs_destroy_marked_extents(struct btrfs_root *root,
57 struct extent_io_tree *dirty_pages,
58 int mark);
59static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
60 struct extent_io_tree *pinned_extents);
61static int btrfs_cleanup_transaction(struct btrfs_root *root);
62
63/*
64 * end_io_wq structs are used to do processing in task context when an IO is
65 * complete. This is used during reads to verify checksums, and it is used
66 * by writes to insert metadata for new file extents after IO is complete.
67 */
68struct end_io_wq {
69 struct bio *bio;
70 bio_end_io_t *end_io;
71 void *private;
72 struct btrfs_fs_info *info;
73 int error;
74 int metadata;
75 struct list_head list;
76 struct btrfs_work work;
77};
78
79/*
80 * async submit bios are used to offload expensive checksumming
81 * onto the worker threads. They checksum file and metadata bios
82 * just before they are sent down the IO stack.
83 */
84struct async_submit_bio {
85 struct inode *inode;
86 struct bio *bio;
87 struct list_head list;
88 extent_submit_bio_hook_t *submit_bio_start;
89 extent_submit_bio_hook_t *submit_bio_done;
90 int rw;
91 int mirror_num;
92 unsigned long bio_flags;
93 /*
94 * bio_offset is optional, can be used if the pages in the bio
95 * can't tell us where in the file the bio should go
96 */
97 u64 bio_offset;
98 struct btrfs_work work;
99};
100
101/* These are used to set the lockdep class on the extent buffer locks.
102 * The class is set by the readpage_end_io_hook after the buffer has
103 * passed csum validation but before the pages are unlocked.
104 *
105 * The lockdep class is also set by btrfs_init_new_buffer on freshly
106 * allocated blocks.
107 *
108 * The class is based on the level in the tree block, which allows lockdep
109 * to know that lower nodes nest inside the locks of higher nodes.
110 *
111 * We also add a check to make sure the highest level of the tree is
112 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
113 * code needs update as well.
114 */
115#ifdef CONFIG_DEBUG_LOCK_ALLOC
116# if BTRFS_MAX_LEVEL != 8
117# error
118# endif
119static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
120static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
121 /* leaf */
122 "btrfs-extent-00",
123 "btrfs-extent-01",
124 "btrfs-extent-02",
125 "btrfs-extent-03",
126 "btrfs-extent-04",
127 "btrfs-extent-05",
128 "btrfs-extent-06",
129 "btrfs-extent-07",
130 /* highest possible level */
131 "btrfs-extent-08",
132};
133#endif
134
135/*
136 * extents on the btree inode are pretty simple, there's one extent
137 * that covers the entire device
138 */
139static struct extent_map *btree_get_extent(struct inode *inode,
140 struct page *page, size_t pg_offset, u64 start, u64 len,
141 int create)
142{
143 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
144 struct extent_map *em;
145 int ret;
146
147 read_lock(&em_tree->lock);
148 em = lookup_extent_mapping(em_tree, start, len);
149 if (em) {
150 em->bdev =
151 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
152 read_unlock(&em_tree->lock);
153 goto out;
154 }
155 read_unlock(&em_tree->lock);
156
157 em = alloc_extent_map(GFP_NOFS);
158 if (!em) {
159 em = ERR_PTR(-ENOMEM);
160 goto out;
161 }
162 em->start = 0;
163 em->len = (u64)-1;
164 em->block_len = (u64)-1;
165 em->block_start = 0;
166 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
167
168 write_lock(&em_tree->lock);
169 ret = add_extent_mapping(em_tree, em);
170 if (ret == -EEXIST) {
171 u64 failed_start = em->start;
172 u64 failed_len = em->len;
173
174 free_extent_map(em);
175 em = lookup_extent_mapping(em_tree, start, len);
176 if (em) {
177 ret = 0;
178 } else {
179 em = lookup_extent_mapping(em_tree, failed_start,
180 failed_len);
181 ret = -EIO;
182 }
183 } else if (ret) {
184 free_extent_map(em);
185 em = NULL;
186 }
187 write_unlock(&em_tree->lock);
188
189 if (ret)
190 em = ERR_PTR(ret);
191out:
192 return em;
193}
194
195u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
196{
197 return crc32c(seed, data, len);
198}
199
200void btrfs_csum_final(u32 crc, char *result)
201{
202 put_unaligned_le32(~crc, result);
203}
204
205/*
206 * compute the csum for a btree block, and either verify it or write it
207 * into the csum field of the block.
208 */
209static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
210 int verify)
211{
212 u16 csum_size =
213 btrfs_super_csum_size(&root->fs_info->super_copy);
214 char *result = NULL;
215 unsigned long len;
216 unsigned long cur_len;
217 unsigned long offset = BTRFS_CSUM_SIZE;
218 char *map_token = NULL;
219 char *kaddr;
220 unsigned long map_start;
221 unsigned long map_len;
222 int err;
223 u32 crc = ~(u32)0;
224 unsigned long inline_result;
225
226 len = buf->len - offset;
227 while (len > 0) {
228 err = map_private_extent_buffer(buf, offset, 32,
229 &map_token, &kaddr,
230 &map_start, &map_len, KM_USER0);
231 if (err)
232 return 1;
233 cur_len = min(len, map_len - (offset - map_start));
234 crc = btrfs_csum_data(root, kaddr + offset - map_start,
235 crc, cur_len);
236 len -= cur_len;
237 offset += cur_len;
238 unmap_extent_buffer(buf, map_token, KM_USER0);
239 }
240 if (csum_size > sizeof(inline_result)) {
241 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
242 if (!result)
243 return 1;
244 } else {
245 result = (char *)&inline_result;
246 }
247
248 btrfs_csum_final(crc, result);
249
250 if (verify) {
251 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
252 u32 val;
253 u32 found = 0;
254 memcpy(&found, result, csum_size);
255
256 read_extent_buffer(buf, &val, 0, csum_size);
257 if (printk_ratelimit()) {
258 printk(KERN_INFO "btrfs: %s checksum verify "
259 "failed on %llu wanted %X found %X "
260 "level %d\n",
261 root->fs_info->sb->s_id,
262 (unsigned long long)buf->start, val, found,
263 btrfs_header_level(buf));
264 }
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 */
283static 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 if (printk_ratelimit()) {
300 printk("parent transid verify failed on %llu wanted %llu "
301 "found %llu\n",
302 (unsigned long long)eb->start,
303 (unsigned long long)parent_transid,
304 (unsigned long long)btrfs_header_generation(eb));
305 }
306 ret = 1;
307 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
308out:
309 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
310 &cached_state, GFP_NOFS);
311 return ret;
312}
313
314/*
315 * helper to read a given tree block, doing retries as required when
316 * the checksums don't match and we have alternate mirrors to try.
317 */
318static int btree_read_extent_buffer_pages(struct btrfs_root *root,
319 struct extent_buffer *eb,
320 u64 start, u64 parent_transid)
321{
322 struct extent_io_tree *io_tree;
323 int ret;
324 int num_copies = 0;
325 int mirror_num = 0;
326
327 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
328 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
329 while (1) {
330 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
331 btree_get_extent, mirror_num);
332 if (!ret &&
333 !verify_parent_transid(io_tree, eb, parent_transid))
334 return ret;
335
336 /*
337 * This buffer's crc is fine, but its contents are corrupted, so
338 * there is no reason to read the other copies, they won't be
339 * any less wrong.
340 */
341 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
342 return ret;
343
344 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
345 eb->start, eb->len);
346 if (num_copies == 1)
347 return ret;
348
349 mirror_num++;
350 if (mirror_num > num_copies)
351 return ret;
352 }
353 return -EIO;
354}
355
356/*
357 * checksum a dirty tree block before IO. This has extra checks to make sure
358 * we only fill in the checksum field in the first page of a multi-page block
359 */
360
361static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
362{
363 struct extent_io_tree *tree;
364 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
365 u64 found_start;
366 unsigned long len;
367 struct extent_buffer *eb;
368 int ret;
369
370 tree = &BTRFS_I(page->mapping->host)->io_tree;
371
372 if (page->private == EXTENT_PAGE_PRIVATE) {
373 WARN_ON(1);
374 goto out;
375 }
376 if (!page->private) {
377 WARN_ON(1);
378 goto out;
379 }
380 len = page->private >> 2;
381 WARN_ON(len == 0);
382
383 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
384 if (eb == NULL) {
385 WARN_ON(1);
386 goto out;
387 }
388 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
389 btrfs_header_generation(eb));
390 BUG_ON(ret);
391 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
392
393 found_start = btrfs_header_bytenr(eb);
394 if (found_start != start) {
395 WARN_ON(1);
396 goto err;
397 }
398 if (eb->first_page != page) {
399 WARN_ON(1);
400 goto err;
401 }
402 if (!PageUptodate(page)) {
403 WARN_ON(1);
404 goto err;
405 }
406 csum_tree_block(root, eb, 0);
407err:
408 free_extent_buffer(eb);
409out:
410 return 0;
411}
412
413static int check_tree_block_fsid(struct btrfs_root *root,
414 struct extent_buffer *eb)
415{
416 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
417 u8 fsid[BTRFS_UUID_SIZE];
418 int ret = 1;
419
420 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
421 BTRFS_FSID_SIZE);
422 while (fs_devices) {
423 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
424 ret = 0;
425 break;
426 }
427 fs_devices = fs_devices->seed;
428 }
429 return ret;
430}
431
432#define CORRUPT(reason, eb, root, slot) \
433 printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
434 "root=%llu, slot=%d\n", reason, \
435 (unsigned long long)btrfs_header_bytenr(eb), \
436 (unsigned long long)root->objectid, slot)
437
438static noinline int check_leaf(struct btrfs_root *root,
439 struct extent_buffer *leaf)
440{
441 struct btrfs_key key;
442 struct btrfs_key leaf_key;
443 u32 nritems = btrfs_header_nritems(leaf);
444 int slot;
445
446 if (nritems == 0)
447 return 0;
448
449 /* Check the 0 item */
450 if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
451 BTRFS_LEAF_DATA_SIZE(root)) {
452 CORRUPT("invalid item offset size pair", leaf, root, 0);
453 return -EIO;
454 }
455
456 /*
457 * Check to make sure each items keys are in the correct order and their
458 * offsets make sense. We only have to loop through nritems-1 because
459 * we check the current slot against the next slot, which verifies the
460 * next slot's offset+size makes sense and that the current's slot
461 * offset is correct.
462 */
463 for (slot = 0; slot < nritems - 1; slot++) {
464 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
465 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
466
467 /* Make sure the keys are in the right order */
468 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
469 CORRUPT("bad key order", leaf, root, slot);
470 return -EIO;
471 }
472
473 /*
474 * Make sure the offset and ends are right, remember that the
475 * item data starts at the end of the leaf and grows towards the
476 * front.
477 */
478 if (btrfs_item_offset_nr(leaf, slot) !=
479 btrfs_item_end_nr(leaf, slot + 1)) {
480 CORRUPT("slot offset bad", leaf, root, slot);
481 return -EIO;
482 }
483
484 /*
485 * Check to make sure that we don't point outside of the leaf,
486 * just incase all the items are consistent to eachother, but
487 * all point outside of the leaf.
488 */
489 if (btrfs_item_end_nr(leaf, slot) >
490 BTRFS_LEAF_DATA_SIZE(root)) {
491 CORRUPT("slot end outside of leaf", leaf, root, slot);
492 return -EIO;
493 }
494 }
495
496 return 0;
497}
498
499#ifdef CONFIG_DEBUG_LOCK_ALLOC
500void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
501{
502 lockdep_set_class_and_name(&eb->lock,
503 &btrfs_eb_class[level],
504 btrfs_eb_name[level]);
505}
506#endif
507
508static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
509 struct extent_state *state)
510{
511 struct extent_io_tree *tree;
512 u64 found_start;
513 int found_level;
514 unsigned long len;
515 struct extent_buffer *eb;
516 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
517 int ret = 0;
518
519 tree = &BTRFS_I(page->mapping->host)->io_tree;
520 if (page->private == EXTENT_PAGE_PRIVATE)
521 goto out;
522 if (!page->private)
523 goto out;
524
525 len = page->private >> 2;
526 WARN_ON(len == 0);
527
528 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
529 if (eb == NULL) {
530 ret = -EIO;
531 goto out;
532 }
533
534 found_start = btrfs_header_bytenr(eb);
535 if (found_start != start) {
536 if (printk_ratelimit()) {
537 printk(KERN_INFO "btrfs bad tree block start "
538 "%llu %llu\n",
539 (unsigned long long)found_start,
540 (unsigned long long)eb->start);
541 }
542 ret = -EIO;
543 goto err;
544 }
545 if (eb->first_page != page) {
546 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
547 eb->first_page->index, page->index);
548 WARN_ON(1);
549 ret = -EIO;
550 goto err;
551 }
552 if (check_tree_block_fsid(root, eb)) {
553 if (printk_ratelimit()) {
554 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
555 (unsigned long long)eb->start);
556 }
557 ret = -EIO;
558 goto err;
559 }
560 found_level = btrfs_header_level(eb);
561
562 btrfs_set_buffer_lockdep_class(eb, found_level);
563
564 ret = csum_tree_block(root, eb, 1);
565 if (ret) {
566 ret = -EIO;
567 goto err;
568 }
569
570 /*
571 * If this is a leaf block and it is corrupt, set the corrupt bit so
572 * that we don't try and read the other copies of this block, just
573 * return -EIO.
574 */
575 if (found_level == 0 && check_leaf(root, eb)) {
576 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
577 ret = -EIO;
578 }
579
580 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
581 end = eb->start + end - 1;
582err:
583 free_extent_buffer(eb);
584out:
585 return ret;
586}
587
588static void end_workqueue_bio(struct bio *bio, int err)
589{
590 struct end_io_wq *end_io_wq = bio->bi_private;
591 struct btrfs_fs_info *fs_info;
592
593 fs_info = end_io_wq->info;
594 end_io_wq->error = err;
595 end_io_wq->work.func = end_workqueue_fn;
596 end_io_wq->work.flags = 0;
597
598 if (bio->bi_rw & REQ_WRITE) {
599 if (end_io_wq->metadata == 1)
600 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
601 &end_io_wq->work);
602 else if (end_io_wq->metadata == 2)
603 btrfs_queue_worker(&fs_info->endio_freespace_worker,
604 &end_io_wq->work);
605 else
606 btrfs_queue_worker(&fs_info->endio_write_workers,
607 &end_io_wq->work);
608 } else {
609 if (end_io_wq->metadata)
610 btrfs_queue_worker(&fs_info->endio_meta_workers,
611 &end_io_wq->work);
612 else
613 btrfs_queue_worker(&fs_info->endio_workers,
614 &end_io_wq->work);
615 }
616}
617
618/*
619 * For the metadata arg you want
620 *
621 * 0 - if data
622 * 1 - if normal metadta
623 * 2 - if writing to the free space cache area
624 */
625int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
626 int metadata)
627{
628 struct end_io_wq *end_io_wq;
629 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
630 if (!end_io_wq)
631 return -ENOMEM;
632
633 end_io_wq->private = bio->bi_private;
634 end_io_wq->end_io = bio->bi_end_io;
635 end_io_wq->info = info;
636 end_io_wq->error = 0;
637 end_io_wq->bio = bio;
638 end_io_wq->metadata = metadata;
639
640 bio->bi_private = end_io_wq;
641 bio->bi_end_io = end_workqueue_bio;
642 return 0;
643}
644
645unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
646{
647 unsigned long limit = min_t(unsigned long,
648 info->workers.max_workers,
649 info->fs_devices->open_devices);
650 return 256 * limit;
651}
652
653int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
654{
655 return atomic_read(&info->nr_async_bios) >
656 btrfs_async_submit_limit(info);
657}
658
659static void run_one_async_start(struct btrfs_work *work)
660{
661 struct async_submit_bio *async;
662
663 async = container_of(work, struct async_submit_bio, work);
664 async->submit_bio_start(async->inode, async->rw, async->bio,
665 async->mirror_num, async->bio_flags,
666 async->bio_offset);
667}
668
669static void run_one_async_done(struct btrfs_work *work)
670{
671 struct btrfs_fs_info *fs_info;
672 struct async_submit_bio *async;
673 int limit;
674
675 async = container_of(work, struct async_submit_bio, work);
676 fs_info = BTRFS_I(async->inode)->root->fs_info;
677
678 limit = btrfs_async_submit_limit(fs_info);
679 limit = limit * 2 / 3;
680
681 atomic_dec(&fs_info->nr_async_submits);
682
683 if (atomic_read(&fs_info->nr_async_submits) < limit &&
684 waitqueue_active(&fs_info->async_submit_wait))
685 wake_up(&fs_info->async_submit_wait);
686
687 async->submit_bio_done(async->inode, async->rw, async->bio,
688 async->mirror_num, async->bio_flags,
689 async->bio_offset);
690}
691
692static void run_one_async_free(struct btrfs_work *work)
693{
694 struct async_submit_bio *async;
695
696 async = container_of(work, struct async_submit_bio, work);
697 kfree(async);
698}
699
700int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
701 int rw, struct bio *bio, int mirror_num,
702 unsigned long bio_flags,
703 u64 bio_offset,
704 extent_submit_bio_hook_t *submit_bio_start,
705 extent_submit_bio_hook_t *submit_bio_done)
706{
707 struct async_submit_bio *async;
708
709 async = kmalloc(sizeof(*async), GFP_NOFS);
710 if (!async)
711 return -ENOMEM;
712
713 async->inode = inode;
714 async->rw = rw;
715 async->bio = bio;
716 async->mirror_num = mirror_num;
717 async->submit_bio_start = submit_bio_start;
718 async->submit_bio_done = submit_bio_done;
719
720 async->work.func = run_one_async_start;
721 async->work.ordered_func = run_one_async_done;
722 async->work.ordered_free = run_one_async_free;
723
724 async->work.flags = 0;
725 async->bio_flags = bio_flags;
726 async->bio_offset = bio_offset;
727
728 atomic_inc(&fs_info->nr_async_submits);
729
730 if (rw & REQ_SYNC)
731 btrfs_set_work_high_prio(&async->work);
732
733 btrfs_queue_worker(&fs_info->workers, &async->work);
734
735 while (atomic_read(&fs_info->async_submit_draining) &&
736 atomic_read(&fs_info->nr_async_submits)) {
737 wait_event(fs_info->async_submit_wait,
738 (atomic_read(&fs_info->nr_async_submits) == 0));
739 }
740
741 return 0;
742}
743
744static int btree_csum_one_bio(struct bio *bio)
745{
746 struct bio_vec *bvec = bio->bi_io_vec;
747 int bio_index = 0;
748 struct btrfs_root *root;
749
750 WARN_ON(bio->bi_vcnt <= 0);
751 while (bio_index < bio->bi_vcnt) {
752 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
753 csum_dirty_buffer(root, bvec->bv_page);
754 bio_index++;
755 bvec++;
756 }
757 return 0;
758}
759
760static int __btree_submit_bio_start(struct inode *inode, int rw,
761 struct bio *bio, int mirror_num,
762 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 btree_csum_one_bio(bio);
770 return 0;
771}
772
773static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
774 int mirror_num, unsigned long bio_flags,
775 u64 bio_offset)
776{
777 /*
778 * when we're called for a write, we're already in the async
779 * submission context. Just jump into btrfs_map_bio
780 */
781 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
782}
783
784static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
785 int mirror_num, unsigned long bio_flags,
786 u64 bio_offset)
787{
788 int ret;
789
790 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
791 bio, 1);
792 BUG_ON(ret);
793
794 if (!(rw & REQ_WRITE)) {
795 /*
796 * called for a read, do the setup so that checksum validation
797 * can happen in the async kernel threads
798 */
799 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
800 mirror_num, 0);
801 }
802
803 /*
804 * kthread helpers are used to submit writes so that checksumming
805 * can happen in parallel across all CPUs
806 */
807 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
808 inode, rw, bio, mirror_num, 0,
809 bio_offset,
810 __btree_submit_bio_start,
811 __btree_submit_bio_done);
812}
813
814#ifdef CONFIG_MIGRATION
815static int btree_migratepage(struct address_space *mapping,
816 struct page *newpage, struct page *page)
817{
818 /*
819 * we can't safely write a btree page from here,
820 * we haven't done the locking hook
821 */
822 if (PageDirty(page))
823 return -EAGAIN;
824 /*
825 * Buffers may be managed in a filesystem specific way.
826 * We must have no buffers or drop them.
827 */
828 if (page_has_private(page) &&
829 !try_to_release_page(page, GFP_KERNEL))
830 return -EAGAIN;
831 return migrate_page(mapping, newpage, page);
832}
833#endif
834
835static int btree_writepage(struct page *page, struct writeback_control *wbc)
836{
837 struct extent_io_tree *tree;
838 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
839 struct extent_buffer *eb;
840 int was_dirty;
841
842 tree = &BTRFS_I(page->mapping->host)->io_tree;
843 if (!(current->flags & PF_MEMALLOC)) {
844 return extent_write_full_page(tree, page,
845 btree_get_extent, wbc);
846 }
847
848 redirty_page_for_writepage(wbc, page);
849 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
850 WARN_ON(!eb);
851
852 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
853 if (!was_dirty) {
854 spin_lock(&root->fs_info->delalloc_lock);
855 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
856 spin_unlock(&root->fs_info->delalloc_lock);
857 }
858 free_extent_buffer(eb);
859
860 unlock_page(page);
861 return 0;
862}
863
864static int btree_writepages(struct address_space *mapping,
865 struct writeback_control *wbc)
866{
867 struct extent_io_tree *tree;
868 tree = &BTRFS_I(mapping->host)->io_tree;
869 if (wbc->sync_mode == WB_SYNC_NONE) {
870 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
871 u64 num_dirty;
872 unsigned long thresh = 32 * 1024 * 1024;
873
874 if (wbc->for_kupdate)
875 return 0;
876
877 /* this is a bit racy, but that's ok */
878 num_dirty = root->fs_info->dirty_metadata_bytes;
879 if (num_dirty < thresh)
880 return 0;
881 }
882 return extent_writepages(tree, mapping, btree_get_extent, wbc);
883}
884
885static int btree_readpage(struct file *file, struct page *page)
886{
887 struct extent_io_tree *tree;
888 tree = &BTRFS_I(page->mapping->host)->io_tree;
889 return extent_read_full_page(tree, page, btree_get_extent);
890}
891
892static int btree_releasepage(struct page *page, gfp_t gfp_flags)
893{
894 struct extent_io_tree *tree;
895 struct extent_map_tree *map;
896 int ret;
897
898 if (PageWriteback(page) || PageDirty(page))
899 return 0;
900
901 tree = &BTRFS_I(page->mapping->host)->io_tree;
902 map = &BTRFS_I(page->mapping->host)->extent_tree;
903
904 ret = try_release_extent_state(map, tree, page, gfp_flags);
905 if (!ret)
906 return 0;
907
908 ret = try_release_extent_buffer(tree, page);
909 if (ret == 1) {
910 ClearPagePrivate(page);
911 set_page_private(page, 0);
912 page_cache_release(page);
913 }
914
915 return ret;
916}
917
918static void btree_invalidatepage(struct page *page, unsigned long offset)
919{
920 struct extent_io_tree *tree;
921 tree = &BTRFS_I(page->mapping->host)->io_tree;
922 extent_invalidatepage(tree, page, offset);
923 btree_releasepage(page, GFP_NOFS);
924 if (PagePrivate(page)) {
925 printk(KERN_WARNING "btrfs warning page private not zero "
926 "on page %llu\n", (unsigned long long)page_offset(page));
927 ClearPagePrivate(page);
928 set_page_private(page, 0);
929 page_cache_release(page);
930 }
931}
932
933static const struct address_space_operations btree_aops = {
934 .readpage = btree_readpage,
935 .writepage = btree_writepage,
936 .writepages = btree_writepages,
937 .releasepage = btree_releasepage,
938 .invalidatepage = btree_invalidatepage,
939#ifdef CONFIG_MIGRATION
940 .migratepage = btree_migratepage,
941#endif
942};
943
944int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
945 u64 parent_transid)
946{
947 struct extent_buffer *buf = NULL;
948 struct inode *btree_inode = root->fs_info->btree_inode;
949 int ret = 0;
950
951 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
952 if (!buf)
953 return 0;
954 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
955 buf, 0, 0, btree_get_extent, 0);
956 free_extent_buffer(buf);
957 return ret;
958}
959
960struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
961 u64 bytenr, u32 blocksize)
962{
963 struct inode *btree_inode = root->fs_info->btree_inode;
964 struct extent_buffer *eb;
965 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
966 bytenr, blocksize, GFP_NOFS);
967 return eb;
968}
969
970struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
971 u64 bytenr, u32 blocksize)
972{
973 struct inode *btree_inode = root->fs_info->btree_inode;
974 struct extent_buffer *eb;
975
976 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
977 bytenr, blocksize, NULL, GFP_NOFS);
978 return eb;
979}
980
981
982int btrfs_write_tree_block(struct extent_buffer *buf)
983{
984 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
985 buf->start + buf->len - 1);
986}
987
988int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
989{
990 return filemap_fdatawait_range(buf->first_page->mapping,
991 buf->start, buf->start + buf->len - 1);
992}
993
994struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
995 u32 blocksize, u64 parent_transid)
996{
997 struct extent_buffer *buf = NULL;
998 int ret;
999
1000 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1001 if (!buf)
1002 return NULL;
1003
1004 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1005
1006 if (ret == 0)
1007 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1008 return buf;
1009
1010}
1011
1012int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1013 struct extent_buffer *buf)
1014{
1015 struct inode *btree_inode = root->fs_info->btree_inode;
1016 if (btrfs_header_generation(buf) ==
1017 root->fs_info->running_transaction->transid) {
1018 btrfs_assert_tree_locked(buf);
1019
1020 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1021 spin_lock(&root->fs_info->delalloc_lock);
1022 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1023 root->fs_info->dirty_metadata_bytes -= buf->len;
1024 else
1025 WARN_ON(1);
1026 spin_unlock(&root->fs_info->delalloc_lock);
1027 }
1028
1029 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1030 btrfs_set_lock_blocking(buf);
1031 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1032 buf);
1033 }
1034 return 0;
1035}
1036
1037static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1038 u32 stripesize, struct btrfs_root *root,
1039 struct btrfs_fs_info *fs_info,
1040 u64 objectid)
1041{
1042 root->node = NULL;
1043 root->commit_root = NULL;
1044 root->sectorsize = sectorsize;
1045 root->nodesize = nodesize;
1046 root->leafsize = leafsize;
1047 root->stripesize = stripesize;
1048 root->ref_cows = 0;
1049 root->track_dirty = 0;
1050 root->in_radix = 0;
1051 root->orphan_item_inserted = 0;
1052 root->orphan_cleanup_state = 0;
1053
1054 root->fs_info = fs_info;
1055 root->objectid = objectid;
1056 root->last_trans = 0;
1057 root->highest_objectid = 0;
1058 root->name = NULL;
1059 root->in_sysfs = 0;
1060 root->inode_tree = RB_ROOT;
1061 root->block_rsv = NULL;
1062 root->orphan_block_rsv = NULL;
1063
1064 INIT_LIST_HEAD(&root->dirty_list);
1065 INIT_LIST_HEAD(&root->orphan_list);
1066 INIT_LIST_HEAD(&root->root_list);
1067 spin_lock_init(&root->node_lock);
1068 spin_lock_init(&root->orphan_lock);
1069 spin_lock_init(&root->inode_lock);
1070 spin_lock_init(&root->accounting_lock);
1071 mutex_init(&root->objectid_mutex);
1072 mutex_init(&root->log_mutex);
1073 init_waitqueue_head(&root->log_writer_wait);
1074 init_waitqueue_head(&root->log_commit_wait[0]);
1075 init_waitqueue_head(&root->log_commit_wait[1]);
1076 atomic_set(&root->log_commit[0], 0);
1077 atomic_set(&root->log_commit[1], 0);
1078 atomic_set(&root->log_writers, 0);
1079 root->log_batch = 0;
1080 root->log_transid = 0;
1081 root->last_log_commit = 0;
1082 extent_io_tree_init(&root->dirty_log_pages,
1083 fs_info->btree_inode->i_mapping, GFP_NOFS);
1084
1085 memset(&root->root_key, 0, sizeof(root->root_key));
1086 memset(&root->root_item, 0, sizeof(root->root_item));
1087 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1088 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1089 root->defrag_trans_start = fs_info->generation;
1090 init_completion(&root->kobj_unregister);
1091 root->defrag_running = 0;
1092 root->root_key.objectid = objectid;
1093 root->anon_super.s_root = NULL;
1094 root->anon_super.s_dev = 0;
1095 INIT_LIST_HEAD(&root->anon_super.s_list);
1096 INIT_LIST_HEAD(&root->anon_super.s_instances);
1097 init_rwsem(&root->anon_super.s_umount);
1098
1099 return 0;
1100}
1101
1102static int find_and_setup_root(struct btrfs_root *tree_root,
1103 struct btrfs_fs_info *fs_info,
1104 u64 objectid,
1105 struct btrfs_root *root)
1106{
1107 int ret;
1108 u32 blocksize;
1109 u64 generation;
1110
1111 __setup_root(tree_root->nodesize, tree_root->leafsize,
1112 tree_root->sectorsize, tree_root->stripesize,
1113 root, fs_info, objectid);
1114 ret = btrfs_find_last_root(tree_root, objectid,
1115 &root->root_item, &root->root_key);
1116 if (ret > 0)
1117 return -ENOENT;
1118 BUG_ON(ret);
1119
1120 generation = btrfs_root_generation(&root->root_item);
1121 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1122 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1123 blocksize, generation);
1124 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1125 free_extent_buffer(root->node);
1126 return -EIO;
1127 }
1128 root->commit_root = btrfs_root_node(root);
1129 return 0;
1130}
1131
1132static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1133 struct btrfs_fs_info *fs_info)
1134{
1135 struct btrfs_root *root;
1136 struct btrfs_root *tree_root = fs_info->tree_root;
1137 struct extent_buffer *leaf;
1138
1139 root = kzalloc(sizeof(*root), GFP_NOFS);
1140 if (!root)
1141 return ERR_PTR(-ENOMEM);
1142
1143 __setup_root(tree_root->nodesize, tree_root->leafsize,
1144 tree_root->sectorsize, tree_root->stripesize,
1145 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1146
1147 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1148 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1149 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1150 /*
1151 * log trees do not get reference counted because they go away
1152 * before a real commit is actually done. They do store pointers
1153 * to file data extents, and those reference counts still get
1154 * updated (along with back refs to the log tree).
1155 */
1156 root->ref_cows = 0;
1157
1158 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1159 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1160 if (IS_ERR(leaf)) {
1161 kfree(root);
1162 return ERR_CAST(leaf);
1163 }
1164
1165 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1166 btrfs_set_header_bytenr(leaf, leaf->start);
1167 btrfs_set_header_generation(leaf, trans->transid);
1168 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1169 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1170 root->node = leaf;
1171
1172 write_extent_buffer(root->node, root->fs_info->fsid,
1173 (unsigned long)btrfs_header_fsid(root->node),
1174 BTRFS_FSID_SIZE);
1175 btrfs_mark_buffer_dirty(root->node);
1176 btrfs_tree_unlock(root->node);
1177 return root;
1178}
1179
1180int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1181 struct btrfs_fs_info *fs_info)
1182{
1183 struct btrfs_root *log_root;
1184
1185 log_root = alloc_log_tree(trans, fs_info);
1186 if (IS_ERR(log_root))
1187 return PTR_ERR(log_root);
1188 WARN_ON(fs_info->log_root_tree);
1189 fs_info->log_root_tree = log_root;
1190 return 0;
1191}
1192
1193int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1194 struct btrfs_root *root)
1195{
1196 struct btrfs_root *log_root;
1197 struct btrfs_inode_item *inode_item;
1198
1199 log_root = alloc_log_tree(trans, root->fs_info);
1200 if (IS_ERR(log_root))
1201 return PTR_ERR(log_root);
1202
1203 log_root->last_trans = trans->transid;
1204 log_root->root_key.offset = root->root_key.objectid;
1205
1206 inode_item = &log_root->root_item.inode;
1207 inode_item->generation = cpu_to_le64(1);
1208 inode_item->size = cpu_to_le64(3);
1209 inode_item->nlink = cpu_to_le32(1);
1210 inode_item->nbytes = cpu_to_le64(root->leafsize);
1211 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1212
1213 btrfs_set_root_node(&log_root->root_item, log_root->node);
1214
1215 WARN_ON(root->log_root);
1216 root->log_root = log_root;
1217 root->log_transid = 0;
1218 root->last_log_commit = 0;
1219 return 0;
1220}
1221
1222struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1223 struct btrfs_key *location)
1224{
1225 struct btrfs_root *root;
1226 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1227 struct btrfs_path *path;
1228 struct extent_buffer *l;
1229 u64 generation;
1230 u32 blocksize;
1231 int ret = 0;
1232
1233 root = kzalloc(sizeof(*root), GFP_NOFS);
1234 if (!root)
1235 return ERR_PTR(-ENOMEM);
1236 if (location->offset == (u64)-1) {
1237 ret = find_and_setup_root(tree_root, fs_info,
1238 location->objectid, root);
1239 if (ret) {
1240 kfree(root);
1241 return ERR_PTR(ret);
1242 }
1243 goto out;
1244 }
1245
1246 __setup_root(tree_root->nodesize, tree_root->leafsize,
1247 tree_root->sectorsize, tree_root->stripesize,
1248 root, fs_info, location->objectid);
1249
1250 path = btrfs_alloc_path();
1251 if (!path) {
1252 kfree(root);
1253 return ERR_PTR(-ENOMEM);
1254 }
1255 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1256 if (ret == 0) {
1257 l = path->nodes[0];
1258 read_extent_buffer(l, &root->root_item,
1259 btrfs_item_ptr_offset(l, path->slots[0]),
1260 sizeof(root->root_item));
1261 memcpy(&root->root_key, location, sizeof(*location));
1262 }
1263 btrfs_free_path(path);
1264 if (ret) {
1265 kfree(root);
1266 if (ret > 0)
1267 ret = -ENOENT;
1268 return ERR_PTR(ret);
1269 }
1270
1271 generation = btrfs_root_generation(&root->root_item);
1272 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1273 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1274 blocksize, generation);
1275 root->commit_root = btrfs_root_node(root);
1276 BUG_ON(!root->node);
1277out:
1278 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1279 root->ref_cows = 1;
1280 btrfs_check_and_init_root_item(&root->root_item);
1281 }
1282
1283 return root;
1284}
1285
1286struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1287 u64 root_objectid)
1288{
1289 struct btrfs_root *root;
1290
1291 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1292 return fs_info->tree_root;
1293 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1294 return fs_info->extent_root;
1295
1296 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1297 (unsigned long)root_objectid);
1298 return root;
1299}
1300
1301struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1302 struct btrfs_key *location)
1303{
1304 struct btrfs_root *root;
1305 int ret;
1306
1307 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1308 return fs_info->tree_root;
1309 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1310 return fs_info->extent_root;
1311 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1312 return fs_info->chunk_root;
1313 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1314 return fs_info->dev_root;
1315 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1316 return fs_info->csum_root;
1317again:
1318 spin_lock(&fs_info->fs_roots_radix_lock);
1319 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1320 (unsigned long)location->objectid);
1321 spin_unlock(&fs_info->fs_roots_radix_lock);
1322 if (root)
1323 return root;
1324
1325 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1326 if (IS_ERR(root))
1327 return root;
1328
1329 set_anon_super(&root->anon_super, NULL);
1330
1331 if (btrfs_root_refs(&root->root_item) == 0) {
1332 ret = -ENOENT;
1333 goto fail;
1334 }
1335
1336 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1337 if (ret < 0)
1338 goto fail;
1339 if (ret == 0)
1340 root->orphan_item_inserted = 1;
1341
1342 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1343 if (ret)
1344 goto fail;
1345
1346 spin_lock(&fs_info->fs_roots_radix_lock);
1347 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1348 (unsigned long)root->root_key.objectid,
1349 root);
1350 if (ret == 0)
1351 root->in_radix = 1;
1352
1353 spin_unlock(&fs_info->fs_roots_radix_lock);
1354 radix_tree_preload_end();
1355 if (ret) {
1356 if (ret == -EEXIST) {
1357 free_fs_root(root);
1358 goto again;
1359 }
1360 goto fail;
1361 }
1362
1363 ret = btrfs_find_dead_roots(fs_info->tree_root,
1364 root->root_key.objectid);
1365 WARN_ON(ret);
1366 return root;
1367fail:
1368 free_fs_root(root);
1369 return ERR_PTR(ret);
1370}
1371
1372struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1373 struct btrfs_key *location,
1374 const char *name, int namelen)
1375{
1376 return btrfs_read_fs_root_no_name(fs_info, location);
1377#if 0
1378 struct btrfs_root *root;
1379 int ret;
1380
1381 root = btrfs_read_fs_root_no_name(fs_info, location);
1382 if (!root)
1383 return NULL;
1384
1385 if (root->in_sysfs)
1386 return root;
1387
1388 ret = btrfs_set_root_name(root, name, namelen);
1389 if (ret) {
1390 free_extent_buffer(root->node);
1391 kfree(root);
1392 return ERR_PTR(ret);
1393 }
1394
1395 ret = btrfs_sysfs_add_root(root);
1396 if (ret) {
1397 free_extent_buffer(root->node);
1398 kfree(root->name);
1399 kfree(root);
1400 return ERR_PTR(ret);
1401 }
1402 root->in_sysfs = 1;
1403 return root;
1404#endif
1405}
1406
1407static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1408{
1409 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1410 int ret = 0;
1411 struct btrfs_device *device;
1412 struct backing_dev_info *bdi;
1413
1414 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1415 if (!device->bdev)
1416 continue;
1417 bdi = blk_get_backing_dev_info(device->bdev);
1418 if (bdi && bdi_congested(bdi, bdi_bits)) {
1419 ret = 1;
1420 break;
1421 }
1422 }
1423 return ret;
1424}
1425
1426/*
1427 * If this fails, caller must call bdi_destroy() to get rid of the
1428 * bdi again.
1429 */
1430static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1431{
1432 int err;
1433
1434 bdi->capabilities = BDI_CAP_MAP_COPY;
1435 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1436 if (err)
1437 return err;
1438
1439 bdi->ra_pages = default_backing_dev_info.ra_pages;
1440 bdi->congested_fn = btrfs_congested_fn;
1441 bdi->congested_data = info;
1442 return 0;
1443}
1444
1445static int bio_ready_for_csum(struct bio *bio)
1446{
1447 u64 length = 0;
1448 u64 buf_len = 0;
1449 u64 start = 0;
1450 struct page *page;
1451 struct extent_io_tree *io_tree = NULL;
1452 struct bio_vec *bvec;
1453 int i;
1454 int ret;
1455
1456 bio_for_each_segment(bvec, bio, i) {
1457 page = bvec->bv_page;
1458 if (page->private == EXTENT_PAGE_PRIVATE) {
1459 length += bvec->bv_len;
1460 continue;
1461 }
1462 if (!page->private) {
1463 length += bvec->bv_len;
1464 continue;
1465 }
1466 length = bvec->bv_len;
1467 buf_len = page->private >> 2;
1468 start = page_offset(page) + bvec->bv_offset;
1469 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1470 }
1471 /* are we fully contained in this bio? */
1472 if (buf_len <= length)
1473 return 1;
1474
1475 ret = extent_range_uptodate(io_tree, start + length,
1476 start + buf_len - 1);
1477 return ret;
1478}
1479
1480/*
1481 * called by the kthread helper functions to finally call the bio end_io
1482 * functions. This is where read checksum verification actually happens
1483 */
1484static void end_workqueue_fn(struct btrfs_work *work)
1485{
1486 struct bio *bio;
1487 struct end_io_wq *end_io_wq;
1488 struct btrfs_fs_info *fs_info;
1489 int error;
1490
1491 end_io_wq = container_of(work, struct end_io_wq, work);
1492 bio = end_io_wq->bio;
1493 fs_info = end_io_wq->info;
1494
1495 /* metadata bio reads are special because the whole tree block must
1496 * be checksummed at once. This makes sure the entire block is in
1497 * ram and up to date before trying to verify things. For
1498 * blocksize <= pagesize, it is basically a noop
1499 */
1500 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1501 !bio_ready_for_csum(bio)) {
1502 btrfs_queue_worker(&fs_info->endio_meta_workers,
1503 &end_io_wq->work);
1504 return;
1505 }
1506 error = end_io_wq->error;
1507 bio->bi_private = end_io_wq->private;
1508 bio->bi_end_io = end_io_wq->end_io;
1509 kfree(end_io_wq);
1510 bio_endio(bio, error);
1511}
1512
1513static int cleaner_kthread(void *arg)
1514{
1515 struct btrfs_root *root = arg;
1516
1517 do {
1518 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1519
1520 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1521 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1522 btrfs_run_delayed_iputs(root);
1523 btrfs_clean_old_snapshots(root);
1524 mutex_unlock(&root->fs_info->cleaner_mutex);
1525 }
1526
1527 if (freezing(current)) {
1528 refrigerator();
1529 } else {
1530 set_current_state(TASK_INTERRUPTIBLE);
1531 if (!kthread_should_stop())
1532 schedule();
1533 __set_current_state(TASK_RUNNING);
1534 }
1535 } while (!kthread_should_stop());
1536 return 0;
1537}
1538
1539static int transaction_kthread(void *arg)
1540{
1541 struct btrfs_root *root = arg;
1542 struct btrfs_trans_handle *trans;
1543 struct btrfs_transaction *cur;
1544 u64 transid;
1545 unsigned long now;
1546 unsigned long delay;
1547 int ret;
1548
1549 do {
1550 delay = HZ * 30;
1551 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1552 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1553
1554 spin_lock(&root->fs_info->new_trans_lock);
1555 cur = root->fs_info->running_transaction;
1556 if (!cur) {
1557 spin_unlock(&root->fs_info->new_trans_lock);
1558 goto sleep;
1559 }
1560
1561 now = get_seconds();
1562 if (!cur->blocked &&
1563 (now < cur->start_time || now - cur->start_time < 30)) {
1564 spin_unlock(&root->fs_info->new_trans_lock);
1565 delay = HZ * 5;
1566 goto sleep;
1567 }
1568 transid = cur->transid;
1569 spin_unlock(&root->fs_info->new_trans_lock);
1570
1571 trans = btrfs_join_transaction(root, 1);
1572 BUG_ON(IS_ERR(trans));
1573 if (transid == trans->transid) {
1574 ret = btrfs_commit_transaction(trans, root);
1575 BUG_ON(ret);
1576 } else {
1577 btrfs_end_transaction(trans, root);
1578 }
1579sleep:
1580 wake_up_process(root->fs_info->cleaner_kthread);
1581 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1582
1583 if (freezing(current)) {
1584 refrigerator();
1585 } else {
1586 set_current_state(TASK_INTERRUPTIBLE);
1587 if (!kthread_should_stop() &&
1588 !btrfs_transaction_blocked(root->fs_info))
1589 schedule_timeout(delay);
1590 __set_current_state(TASK_RUNNING);
1591 }
1592 } while (!kthread_should_stop());
1593 return 0;
1594}
1595
1596struct btrfs_root *open_ctree(struct super_block *sb,
1597 struct btrfs_fs_devices *fs_devices,
1598 char *options)
1599{
1600 u32 sectorsize;
1601 u32 nodesize;
1602 u32 leafsize;
1603 u32 blocksize;
1604 u32 stripesize;
1605 u64 generation;
1606 u64 features;
1607 struct btrfs_key location;
1608 struct buffer_head *bh;
1609 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1610 GFP_NOFS);
1611 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1612 GFP_NOFS);
1613 struct btrfs_root *tree_root = btrfs_sb(sb);
1614 struct btrfs_fs_info *fs_info = NULL;
1615 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1616 GFP_NOFS);
1617 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1618 GFP_NOFS);
1619 struct btrfs_root *log_tree_root;
1620
1621 int ret;
1622 int err = -EINVAL;
1623
1624 struct btrfs_super_block *disk_super;
1625
1626 if (!extent_root || !tree_root || !tree_root->fs_info ||
1627 !chunk_root || !dev_root || !csum_root) {
1628 err = -ENOMEM;
1629 goto fail;
1630 }
1631 fs_info = tree_root->fs_info;
1632
1633 ret = init_srcu_struct(&fs_info->subvol_srcu);
1634 if (ret) {
1635 err = ret;
1636 goto fail;
1637 }
1638
1639 ret = setup_bdi(fs_info, &fs_info->bdi);
1640 if (ret) {
1641 err = ret;
1642 goto fail_srcu;
1643 }
1644
1645 fs_info->btree_inode = new_inode(sb);
1646 if (!fs_info->btree_inode) {
1647 err = -ENOMEM;
1648 goto fail_bdi;
1649 }
1650
1651 fs_info->btree_inode->i_mapping->flags &= ~__GFP_FS;
1652
1653 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1654 INIT_LIST_HEAD(&fs_info->trans_list);
1655 INIT_LIST_HEAD(&fs_info->dead_roots);
1656 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1657 INIT_LIST_HEAD(&fs_info->hashers);
1658 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1659 INIT_LIST_HEAD(&fs_info->ordered_operations);
1660 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1661 spin_lock_init(&fs_info->delalloc_lock);
1662 spin_lock_init(&fs_info->new_trans_lock);
1663 spin_lock_init(&fs_info->ref_cache_lock);
1664 spin_lock_init(&fs_info->fs_roots_radix_lock);
1665 spin_lock_init(&fs_info->delayed_iput_lock);
1666
1667 init_completion(&fs_info->kobj_unregister);
1668 fs_info->tree_root = tree_root;
1669 fs_info->extent_root = extent_root;
1670 fs_info->csum_root = csum_root;
1671 fs_info->chunk_root = chunk_root;
1672 fs_info->dev_root = dev_root;
1673 fs_info->fs_devices = fs_devices;
1674 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1675 INIT_LIST_HEAD(&fs_info->space_info);
1676 btrfs_mapping_init(&fs_info->mapping_tree);
1677 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1678 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1679 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1680 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1681 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1682 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1683 mutex_init(&fs_info->durable_block_rsv_mutex);
1684 atomic_set(&fs_info->nr_async_submits, 0);
1685 atomic_set(&fs_info->async_delalloc_pages, 0);
1686 atomic_set(&fs_info->async_submit_draining, 0);
1687 atomic_set(&fs_info->nr_async_bios, 0);
1688 fs_info->sb = sb;
1689 fs_info->max_inline = 8192 * 1024;
1690 fs_info->metadata_ratio = 0;
1691
1692 fs_info->thread_pool_size = min_t(unsigned long,
1693 num_online_cpus() + 2, 8);
1694
1695 INIT_LIST_HEAD(&fs_info->ordered_extents);
1696 spin_lock_init(&fs_info->ordered_extent_lock);
1697
1698 sb->s_blocksize = 4096;
1699 sb->s_blocksize_bits = blksize_bits(4096);
1700 sb->s_bdi = &fs_info->bdi;
1701
1702 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1703 fs_info->btree_inode->i_nlink = 1;
1704 /*
1705 * we set the i_size on the btree inode to the max possible int.
1706 * the real end of the address space is determined by all of
1707 * the devices in the system
1708 */
1709 fs_info->btree_inode->i_size = OFFSET_MAX;
1710 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1711 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1712
1713 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1714 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1715 fs_info->btree_inode->i_mapping,
1716 GFP_NOFS);
1717 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1718 GFP_NOFS);
1719
1720 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1721
1722 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1723 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1724 sizeof(struct btrfs_key));
1725 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1726 insert_inode_hash(fs_info->btree_inode);
1727
1728 spin_lock_init(&fs_info->block_group_cache_lock);
1729 fs_info->block_group_cache_tree = RB_ROOT;
1730
1731 extent_io_tree_init(&fs_info->freed_extents[0],
1732 fs_info->btree_inode->i_mapping, GFP_NOFS);
1733 extent_io_tree_init(&fs_info->freed_extents[1],
1734 fs_info->btree_inode->i_mapping, GFP_NOFS);
1735 fs_info->pinned_extents = &fs_info->freed_extents[0];
1736 fs_info->do_barriers = 1;
1737
1738
1739 mutex_init(&fs_info->trans_mutex);
1740 mutex_init(&fs_info->ordered_operations_mutex);
1741 mutex_init(&fs_info->tree_log_mutex);
1742 mutex_init(&fs_info->chunk_mutex);
1743 mutex_init(&fs_info->transaction_kthread_mutex);
1744 mutex_init(&fs_info->cleaner_mutex);
1745 mutex_init(&fs_info->volume_mutex);
1746 init_rwsem(&fs_info->extent_commit_sem);
1747 init_rwsem(&fs_info->cleanup_work_sem);
1748 init_rwsem(&fs_info->subvol_sem);
1749
1750 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1751 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1752
1753 init_waitqueue_head(&fs_info->transaction_throttle);
1754 init_waitqueue_head(&fs_info->transaction_wait);
1755 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1756 init_waitqueue_head(&fs_info->async_submit_wait);
1757
1758 __setup_root(4096, 4096, 4096, 4096, tree_root,
1759 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1760
1761 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1762 if (!bh) {
1763 err = -EINVAL;
1764 goto fail_iput;
1765 }
1766
1767 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1768 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1769 sizeof(fs_info->super_for_commit));
1770 brelse(bh);
1771
1772 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1773
1774 disk_super = &fs_info->super_copy;
1775 if (!btrfs_super_root(disk_super))
1776 goto fail_iput;
1777
1778 /* check FS state, whether FS is broken. */
1779 fs_info->fs_state |= btrfs_super_flags(disk_super);
1780
1781 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1782
1783 /*
1784 * In the long term, we'll store the compression type in the super
1785 * block, and it'll be used for per file compression control.
1786 */
1787 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1788
1789 ret = btrfs_parse_options(tree_root, options);
1790 if (ret) {
1791 err = ret;
1792 goto fail_iput;
1793 }
1794
1795 features = btrfs_super_incompat_flags(disk_super) &
1796 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1797 if (features) {
1798 printk(KERN_ERR "BTRFS: couldn't mount because of "
1799 "unsupported optional features (%Lx).\n",
1800 (unsigned long long)features);
1801 err = -EINVAL;
1802 goto fail_iput;
1803 }
1804
1805 features = btrfs_super_incompat_flags(disk_super);
1806 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1807 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1808 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1809 btrfs_set_super_incompat_flags(disk_super, features);
1810
1811 features = btrfs_super_compat_ro_flags(disk_super) &
1812 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1813 if (!(sb->s_flags & MS_RDONLY) && features) {
1814 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1815 "unsupported option features (%Lx).\n",
1816 (unsigned long long)features);
1817 err = -EINVAL;
1818 goto fail_iput;
1819 }
1820
1821 btrfs_init_workers(&fs_info->generic_worker,
1822 "genwork", 1, NULL);
1823
1824 btrfs_init_workers(&fs_info->workers, "worker",
1825 fs_info->thread_pool_size,
1826 &fs_info->generic_worker);
1827
1828 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1829 fs_info->thread_pool_size,
1830 &fs_info->generic_worker);
1831
1832 btrfs_init_workers(&fs_info->submit_workers, "submit",
1833 min_t(u64, fs_devices->num_devices,
1834 fs_info->thread_pool_size),
1835 &fs_info->generic_worker);
1836
1837 /* a higher idle thresh on the submit workers makes it much more
1838 * likely that bios will be send down in a sane order to the
1839 * devices
1840 */
1841 fs_info->submit_workers.idle_thresh = 64;
1842
1843 fs_info->workers.idle_thresh = 16;
1844 fs_info->workers.ordered = 1;
1845
1846 fs_info->delalloc_workers.idle_thresh = 2;
1847 fs_info->delalloc_workers.ordered = 1;
1848
1849 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1850 &fs_info->generic_worker);
1851 btrfs_init_workers(&fs_info->endio_workers, "endio",
1852 fs_info->thread_pool_size,
1853 &fs_info->generic_worker);
1854 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1855 fs_info->thread_pool_size,
1856 &fs_info->generic_worker);
1857 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1858 "endio-meta-write", fs_info->thread_pool_size,
1859 &fs_info->generic_worker);
1860 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1861 fs_info->thread_pool_size,
1862 &fs_info->generic_worker);
1863 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1864 1, &fs_info->generic_worker);
1865
1866 /*
1867 * endios are largely parallel and should have a very
1868 * low idle thresh
1869 */
1870 fs_info->endio_workers.idle_thresh = 4;
1871 fs_info->endio_meta_workers.idle_thresh = 4;
1872
1873 fs_info->endio_write_workers.idle_thresh = 2;
1874 fs_info->endio_meta_write_workers.idle_thresh = 2;
1875
1876 btrfs_start_workers(&fs_info->workers, 1);
1877 btrfs_start_workers(&fs_info->generic_worker, 1);
1878 btrfs_start_workers(&fs_info->submit_workers, 1);
1879 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1880 btrfs_start_workers(&fs_info->fixup_workers, 1);
1881 btrfs_start_workers(&fs_info->endio_workers, 1);
1882 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1883 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1884 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1885 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1886
1887 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1888 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1889 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1890
1891 nodesize = btrfs_super_nodesize(disk_super);
1892 leafsize = btrfs_super_leafsize(disk_super);
1893 sectorsize = btrfs_super_sectorsize(disk_super);
1894 stripesize = btrfs_super_stripesize(disk_super);
1895 tree_root->nodesize = nodesize;
1896 tree_root->leafsize = leafsize;
1897 tree_root->sectorsize = sectorsize;
1898 tree_root->stripesize = stripesize;
1899
1900 sb->s_blocksize = sectorsize;
1901 sb->s_blocksize_bits = blksize_bits(sectorsize);
1902
1903 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1904 sizeof(disk_super->magic))) {
1905 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1906 goto fail_sb_buffer;
1907 }
1908
1909 mutex_lock(&fs_info->chunk_mutex);
1910 ret = btrfs_read_sys_array(tree_root);
1911 mutex_unlock(&fs_info->chunk_mutex);
1912 if (ret) {
1913 printk(KERN_WARNING "btrfs: failed to read the system "
1914 "array on %s\n", sb->s_id);
1915 goto fail_sb_buffer;
1916 }
1917
1918 blocksize = btrfs_level_size(tree_root,
1919 btrfs_super_chunk_root_level(disk_super));
1920 generation = btrfs_super_chunk_root_generation(disk_super);
1921
1922 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1923 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1924
1925 chunk_root->node = read_tree_block(chunk_root,
1926 btrfs_super_chunk_root(disk_super),
1927 blocksize, generation);
1928 BUG_ON(!chunk_root->node);
1929 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1930 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1931 sb->s_id);
1932 goto fail_chunk_root;
1933 }
1934 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1935 chunk_root->commit_root = btrfs_root_node(chunk_root);
1936
1937 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1938 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1939 BTRFS_UUID_SIZE);
1940
1941 mutex_lock(&fs_info->chunk_mutex);
1942 ret = btrfs_read_chunk_tree(chunk_root);
1943 mutex_unlock(&fs_info->chunk_mutex);
1944 if (ret) {
1945 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1946 sb->s_id);
1947 goto fail_chunk_root;
1948 }
1949
1950 btrfs_close_extra_devices(fs_devices);
1951
1952 blocksize = btrfs_level_size(tree_root,
1953 btrfs_super_root_level(disk_super));
1954 generation = btrfs_super_generation(disk_super);
1955
1956 tree_root->node = read_tree_block(tree_root,
1957 btrfs_super_root(disk_super),
1958 blocksize, generation);
1959 if (!tree_root->node)
1960 goto fail_chunk_root;
1961 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1962 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1963 sb->s_id);
1964 goto fail_tree_root;
1965 }
1966 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1967 tree_root->commit_root = btrfs_root_node(tree_root);
1968
1969 ret = find_and_setup_root(tree_root, fs_info,
1970 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1971 if (ret)
1972 goto fail_tree_root;
1973 extent_root->track_dirty = 1;
1974
1975 ret = find_and_setup_root(tree_root, fs_info,
1976 BTRFS_DEV_TREE_OBJECTID, dev_root);
1977 if (ret)
1978 goto fail_extent_root;
1979 dev_root->track_dirty = 1;
1980
1981 ret = find_and_setup_root(tree_root, fs_info,
1982 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1983 if (ret)
1984 goto fail_dev_root;
1985
1986 csum_root->track_dirty = 1;
1987
1988 fs_info->generation = generation;
1989 fs_info->last_trans_committed = generation;
1990 fs_info->data_alloc_profile = (u64)-1;
1991 fs_info->metadata_alloc_profile = (u64)-1;
1992 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1993
1994 ret = btrfs_init_space_info(fs_info);
1995 if (ret) {
1996 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
1997 goto fail_block_groups;
1998 }
1999
2000 ret = btrfs_read_block_groups(extent_root);
2001 if (ret) {
2002 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2003 goto fail_block_groups;
2004 }
2005
2006 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2007 "btrfs-cleaner");
2008 if (IS_ERR(fs_info->cleaner_kthread))
2009 goto fail_block_groups;
2010
2011 fs_info->transaction_kthread = kthread_run(transaction_kthread,
2012 tree_root,
2013 "btrfs-transaction");
2014 if (IS_ERR(fs_info->transaction_kthread))
2015 goto fail_cleaner;
2016
2017 if (!btrfs_test_opt(tree_root, SSD) &&
2018 !btrfs_test_opt(tree_root, NOSSD) &&
2019 !fs_info->fs_devices->rotating) {
2020 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2021 "mode\n");
2022 btrfs_set_opt(fs_info->mount_opt, SSD);
2023 }
2024
2025 /* do not make disk changes in broken FS */
2026 if (btrfs_super_log_root(disk_super) != 0 &&
2027 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2028 u64 bytenr = btrfs_super_log_root(disk_super);
2029
2030 if (fs_devices->rw_devices == 0) {
2031 printk(KERN_WARNING "Btrfs log replay required "
2032 "on RO media\n");
2033 err = -EIO;
2034 goto fail_trans_kthread;
2035 }
2036 blocksize =
2037 btrfs_level_size(tree_root,
2038 btrfs_super_log_root_level(disk_super));
2039
2040 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2041 if (!log_tree_root) {
2042 err = -ENOMEM;
2043 goto fail_trans_kthread;
2044 }
2045
2046 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2047 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2048
2049 log_tree_root->node = read_tree_block(tree_root, bytenr,
2050 blocksize,
2051 generation + 1);
2052 ret = btrfs_recover_log_trees(log_tree_root);
2053 BUG_ON(ret);
2054
2055 if (sb->s_flags & MS_RDONLY) {
2056 ret = btrfs_commit_super(tree_root);
2057 BUG_ON(ret);
2058 }
2059 }
2060
2061 ret = btrfs_find_orphan_roots(tree_root);
2062 BUG_ON(ret);
2063
2064 if (!(sb->s_flags & MS_RDONLY)) {
2065 ret = btrfs_cleanup_fs_roots(fs_info);
2066 BUG_ON(ret);
2067
2068 ret = btrfs_recover_relocation(tree_root);
2069 if (ret < 0) {
2070 printk(KERN_WARNING
2071 "btrfs: failed to recover relocation\n");
2072 err = -EINVAL;
2073 goto fail_trans_kthread;
2074 }
2075 }
2076
2077 location.objectid = BTRFS_FS_TREE_OBJECTID;
2078 location.type = BTRFS_ROOT_ITEM_KEY;
2079 location.offset = (u64)-1;
2080
2081 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2082 if (!fs_info->fs_root)
2083 goto fail_trans_kthread;
2084 if (IS_ERR(fs_info->fs_root)) {
2085 err = PTR_ERR(fs_info->fs_root);
2086 goto fail_trans_kthread;
2087 }
2088
2089 if (!(sb->s_flags & MS_RDONLY)) {
2090 down_read(&fs_info->cleanup_work_sem);
2091 err = btrfs_orphan_cleanup(fs_info->fs_root);
2092 if (!err)
2093 err = btrfs_orphan_cleanup(fs_info->tree_root);
2094 up_read(&fs_info->cleanup_work_sem);
2095 if (err) {
2096 close_ctree(tree_root);
2097 return ERR_PTR(err);
2098 }
2099 }
2100
2101 return tree_root;
2102
2103fail_trans_kthread:
2104 kthread_stop(fs_info->transaction_kthread);
2105fail_cleaner:
2106 kthread_stop(fs_info->cleaner_kthread);
2107
2108 /*
2109 * make sure we're done with the btree inode before we stop our
2110 * kthreads
2111 */
2112 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2113 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2114
2115fail_block_groups:
2116 btrfs_free_block_groups(fs_info);
2117 free_extent_buffer(csum_root->node);
2118 free_extent_buffer(csum_root->commit_root);
2119fail_dev_root:
2120 free_extent_buffer(dev_root->node);
2121 free_extent_buffer(dev_root->commit_root);
2122fail_extent_root:
2123 free_extent_buffer(extent_root->node);
2124 free_extent_buffer(extent_root->commit_root);
2125fail_tree_root:
2126 free_extent_buffer(tree_root->node);
2127 free_extent_buffer(tree_root->commit_root);
2128fail_chunk_root:
2129 free_extent_buffer(chunk_root->node);
2130 free_extent_buffer(chunk_root->commit_root);
2131fail_sb_buffer:
2132 btrfs_stop_workers(&fs_info->generic_worker);
2133 btrfs_stop_workers(&fs_info->fixup_workers);
2134 btrfs_stop_workers(&fs_info->delalloc_workers);
2135 btrfs_stop_workers(&fs_info->workers);
2136 btrfs_stop_workers(&fs_info->endio_workers);
2137 btrfs_stop_workers(&fs_info->endio_meta_workers);
2138 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2139 btrfs_stop_workers(&fs_info->endio_write_workers);
2140 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2141 btrfs_stop_workers(&fs_info->submit_workers);
2142fail_iput:
2143 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2144 iput(fs_info->btree_inode);
2145
2146 btrfs_close_devices(fs_info->fs_devices);
2147 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2148fail_bdi:
2149 bdi_destroy(&fs_info->bdi);
2150fail_srcu:
2151 cleanup_srcu_struct(&fs_info->subvol_srcu);
2152fail:
2153 kfree(extent_root);
2154 kfree(tree_root);
2155 kfree(fs_info);
2156 kfree(chunk_root);
2157 kfree(dev_root);
2158 kfree(csum_root);
2159 return ERR_PTR(err);
2160}
2161
2162static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2163{
2164 char b[BDEVNAME_SIZE];
2165
2166 if (uptodate) {
2167 set_buffer_uptodate(bh);
2168 } else {
2169 if (printk_ratelimit()) {
2170 printk(KERN_WARNING "lost page write due to "
2171 "I/O error on %s\n",
2172 bdevname(bh->b_bdev, b));
2173 }
2174 /* note, we dont' set_buffer_write_io_error because we have
2175 * our own ways of dealing with the IO errors
2176 */
2177 clear_buffer_uptodate(bh);
2178 }
2179 unlock_buffer(bh);
2180 put_bh(bh);
2181}
2182
2183struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2184{
2185 struct buffer_head *bh;
2186 struct buffer_head *latest = NULL;
2187 struct btrfs_super_block *super;
2188 int i;
2189 u64 transid = 0;
2190 u64 bytenr;
2191
2192 /* we would like to check all the supers, but that would make
2193 * a btrfs mount succeed after a mkfs from a different FS.
2194 * So, we need to add a special mount option to scan for
2195 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2196 */
2197 for (i = 0; i < 1; i++) {
2198 bytenr = btrfs_sb_offset(i);
2199 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2200 break;
2201 bh = __bread(bdev, bytenr / 4096, 4096);
2202 if (!bh)
2203 continue;
2204
2205 super = (struct btrfs_super_block *)bh->b_data;
2206 if (btrfs_super_bytenr(super) != bytenr ||
2207 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2208 sizeof(super->magic))) {
2209 brelse(bh);
2210 continue;
2211 }
2212
2213 if (!latest || btrfs_super_generation(super) > transid) {
2214 brelse(latest);
2215 latest = bh;
2216 transid = btrfs_super_generation(super);
2217 } else {
2218 brelse(bh);
2219 }
2220 }
2221 return latest;
2222}
2223
2224/*
2225 * this should be called twice, once with wait == 0 and
2226 * once with wait == 1. When wait == 0 is done, all the buffer heads
2227 * we write are pinned.
2228 *
2229 * They are released when wait == 1 is done.
2230 * max_mirrors must be the same for both runs, and it indicates how
2231 * many supers on this one device should be written.
2232 *
2233 * max_mirrors == 0 means to write them all.
2234 */
2235static int write_dev_supers(struct btrfs_device *device,
2236 struct btrfs_super_block *sb,
2237 int do_barriers, int wait, int max_mirrors)
2238{
2239 struct buffer_head *bh;
2240 int i;
2241 int ret;
2242 int errors = 0;
2243 u32 crc;
2244 u64 bytenr;
2245 int last_barrier = 0;
2246
2247 if (max_mirrors == 0)
2248 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2249
2250 /* make sure only the last submit_bh does a barrier */
2251 if (do_barriers) {
2252 for (i = 0; i < max_mirrors; i++) {
2253 bytenr = btrfs_sb_offset(i);
2254 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2255 device->total_bytes)
2256 break;
2257 last_barrier = i;
2258 }
2259 }
2260
2261 for (i = 0; i < max_mirrors; i++) {
2262 bytenr = btrfs_sb_offset(i);
2263 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2264 break;
2265
2266 if (wait) {
2267 bh = __find_get_block(device->bdev, bytenr / 4096,
2268 BTRFS_SUPER_INFO_SIZE);
2269 BUG_ON(!bh);
2270 wait_on_buffer(bh);
2271 if (!buffer_uptodate(bh))
2272 errors++;
2273
2274 /* drop our reference */
2275 brelse(bh);
2276
2277 /* drop the reference from the wait == 0 run */
2278 brelse(bh);
2279 continue;
2280 } else {
2281 btrfs_set_super_bytenr(sb, bytenr);
2282
2283 crc = ~(u32)0;
2284 crc = btrfs_csum_data(NULL, (char *)sb +
2285 BTRFS_CSUM_SIZE, crc,
2286 BTRFS_SUPER_INFO_SIZE -
2287 BTRFS_CSUM_SIZE);
2288 btrfs_csum_final(crc, sb->csum);
2289
2290 /*
2291 * one reference for us, and we leave it for the
2292 * caller
2293 */
2294 bh = __getblk(device->bdev, bytenr / 4096,
2295 BTRFS_SUPER_INFO_SIZE);
2296 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2297
2298 /* one reference for submit_bh */
2299 get_bh(bh);
2300
2301 set_buffer_uptodate(bh);
2302 lock_buffer(bh);
2303 bh->b_end_io = btrfs_end_buffer_write_sync;
2304 }
2305
2306 if (i == last_barrier && do_barriers)
2307 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2308 else
2309 ret = submit_bh(WRITE_SYNC, bh);
2310
2311 if (ret)
2312 errors++;
2313 }
2314 return errors < i ? 0 : -1;
2315}
2316
2317int write_all_supers(struct btrfs_root *root, int max_mirrors)
2318{
2319 struct list_head *head;
2320 struct btrfs_device *dev;
2321 struct btrfs_super_block *sb;
2322 struct btrfs_dev_item *dev_item;
2323 int ret;
2324 int do_barriers;
2325 int max_errors;
2326 int total_errors = 0;
2327 u64 flags;
2328
2329 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2330 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2331
2332 sb = &root->fs_info->super_for_commit;
2333 dev_item = &sb->dev_item;
2334
2335 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2336 head = &root->fs_info->fs_devices->devices;
2337 list_for_each_entry(dev, head, dev_list) {
2338 if (!dev->bdev) {
2339 total_errors++;
2340 continue;
2341 }
2342 if (!dev->in_fs_metadata || !dev->writeable)
2343 continue;
2344
2345 btrfs_set_stack_device_generation(dev_item, 0);
2346 btrfs_set_stack_device_type(dev_item, dev->type);
2347 btrfs_set_stack_device_id(dev_item, dev->devid);
2348 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2349 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2350 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2351 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2352 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2353 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2354 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2355
2356 flags = btrfs_super_flags(sb);
2357 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2358
2359 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2360 if (ret)
2361 total_errors++;
2362 }
2363 if (total_errors > max_errors) {
2364 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2365 total_errors);
2366 BUG();
2367 }
2368
2369 total_errors = 0;
2370 list_for_each_entry(dev, head, dev_list) {
2371 if (!dev->bdev)
2372 continue;
2373 if (!dev->in_fs_metadata || !dev->writeable)
2374 continue;
2375
2376 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2377 if (ret)
2378 total_errors++;
2379 }
2380 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2381 if (total_errors > max_errors) {
2382 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2383 total_errors);
2384 BUG();
2385 }
2386 return 0;
2387}
2388
2389int write_ctree_super(struct btrfs_trans_handle *trans,
2390 struct btrfs_root *root, int max_mirrors)
2391{
2392 int ret;
2393
2394 ret = write_all_supers(root, max_mirrors);
2395 return ret;
2396}
2397
2398int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2399{
2400 spin_lock(&fs_info->fs_roots_radix_lock);
2401 radix_tree_delete(&fs_info->fs_roots_radix,
2402 (unsigned long)root->root_key.objectid);
2403 spin_unlock(&fs_info->fs_roots_radix_lock);
2404
2405 if (btrfs_root_refs(&root->root_item) == 0)
2406 synchronize_srcu(&fs_info->subvol_srcu);
2407
2408 free_fs_root(root);
2409 return 0;
2410}
2411
2412static void free_fs_root(struct btrfs_root *root)
2413{
2414 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2415 if (root->anon_super.s_dev) {
2416 down_write(&root->anon_super.s_umount);
2417 kill_anon_super(&root->anon_super);
2418 }
2419 free_extent_buffer(root->node);
2420 free_extent_buffer(root->commit_root);
2421 kfree(root->name);
2422 kfree(root);
2423}
2424
2425static int del_fs_roots(struct btrfs_fs_info *fs_info)
2426{
2427 int ret;
2428 struct btrfs_root *gang[8];
2429 int i;
2430
2431 while (!list_empty(&fs_info->dead_roots)) {
2432 gang[0] = list_entry(fs_info->dead_roots.next,
2433 struct btrfs_root, root_list);
2434 list_del(&gang[0]->root_list);
2435
2436 if (gang[0]->in_radix) {
2437 btrfs_free_fs_root(fs_info, gang[0]);
2438 } else {
2439 free_extent_buffer(gang[0]->node);
2440 free_extent_buffer(gang[0]->commit_root);
2441 kfree(gang[0]);
2442 }
2443 }
2444
2445 while (1) {
2446 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2447 (void **)gang, 0,
2448 ARRAY_SIZE(gang));
2449 if (!ret)
2450 break;
2451 for (i = 0; i < ret; i++)
2452 btrfs_free_fs_root(fs_info, gang[i]);
2453 }
2454 return 0;
2455}
2456
2457int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2458{
2459 u64 root_objectid = 0;
2460 struct btrfs_root *gang[8];
2461 int i;
2462 int ret;
2463
2464 while (1) {
2465 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2466 (void **)gang, root_objectid,
2467 ARRAY_SIZE(gang));
2468 if (!ret)
2469 break;
2470
2471 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2472 for (i = 0; i < ret; i++) {
2473 int err;
2474
2475 root_objectid = gang[i]->root_key.objectid;
2476 err = btrfs_orphan_cleanup(gang[i]);
2477 if (err)
2478 return err;
2479 }
2480 root_objectid++;
2481 }
2482 return 0;
2483}
2484
2485int btrfs_commit_super(struct btrfs_root *root)
2486{
2487 struct btrfs_trans_handle *trans;
2488 int ret;
2489
2490 mutex_lock(&root->fs_info->cleaner_mutex);
2491 btrfs_run_delayed_iputs(root);
2492 btrfs_clean_old_snapshots(root);
2493 mutex_unlock(&root->fs_info->cleaner_mutex);
2494
2495 /* wait until ongoing cleanup work done */
2496 down_write(&root->fs_info->cleanup_work_sem);
2497 up_write(&root->fs_info->cleanup_work_sem);
2498
2499 trans = btrfs_join_transaction(root, 1);
2500 if (IS_ERR(trans))
2501 return PTR_ERR(trans);
2502 ret = btrfs_commit_transaction(trans, root);
2503 BUG_ON(ret);
2504 /* run commit again to drop the original snapshot */
2505 trans = btrfs_join_transaction(root, 1);
2506 if (IS_ERR(trans))
2507 return PTR_ERR(trans);
2508 btrfs_commit_transaction(trans, root);
2509 ret = btrfs_write_and_wait_transaction(NULL, root);
2510 BUG_ON(ret);
2511
2512 ret = write_ctree_super(NULL, root, 0);
2513 return ret;
2514}
2515
2516int close_ctree(struct btrfs_root *root)
2517{
2518 struct btrfs_fs_info *fs_info = root->fs_info;
2519 int ret;
2520
2521 fs_info->closing = 1;
2522 smp_mb();
2523
2524 btrfs_put_block_group_cache(fs_info);
2525
2526 /*
2527 * Here come 2 situations when btrfs is broken to flip readonly:
2528 *
2529 * 1. when btrfs flips readonly somewhere else before
2530 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2531 * and btrfs will skip to write sb directly to keep
2532 * ERROR state on disk.
2533 *
2534 * 2. when btrfs flips readonly just in btrfs_commit_super,
2535 * and in such case, btrfs cannot write sb via btrfs_commit_super,
2536 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2537 * btrfs will cleanup all FS resources first and write sb then.
2538 */
2539 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2540 ret = btrfs_commit_super(root);
2541 if (ret)
2542 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2543 }
2544
2545 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2546 ret = btrfs_error_commit_super(root);
2547 if (ret)
2548 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2549 }
2550
2551 kthread_stop(root->fs_info->transaction_kthread);
2552 kthread_stop(root->fs_info->cleaner_kthread);
2553
2554 fs_info->closing = 2;
2555 smp_mb();
2556
2557 if (fs_info->delalloc_bytes) {
2558 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2559 (unsigned long long)fs_info->delalloc_bytes);
2560 }
2561 if (fs_info->total_ref_cache_size) {
2562 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2563 (unsigned long long)fs_info->total_ref_cache_size);
2564 }
2565
2566 free_extent_buffer(fs_info->extent_root->node);
2567 free_extent_buffer(fs_info->extent_root->commit_root);
2568 free_extent_buffer(fs_info->tree_root->node);
2569 free_extent_buffer(fs_info->tree_root->commit_root);
2570 free_extent_buffer(root->fs_info->chunk_root->node);
2571 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2572 free_extent_buffer(root->fs_info->dev_root->node);
2573 free_extent_buffer(root->fs_info->dev_root->commit_root);
2574 free_extent_buffer(root->fs_info->csum_root->node);
2575 free_extent_buffer(root->fs_info->csum_root->commit_root);
2576
2577 btrfs_free_block_groups(root->fs_info);
2578
2579 del_fs_roots(fs_info);
2580
2581 iput(fs_info->btree_inode);
2582
2583 btrfs_stop_workers(&fs_info->generic_worker);
2584 btrfs_stop_workers(&fs_info->fixup_workers);
2585 btrfs_stop_workers(&fs_info->delalloc_workers);
2586 btrfs_stop_workers(&fs_info->workers);
2587 btrfs_stop_workers(&fs_info->endio_workers);
2588 btrfs_stop_workers(&fs_info->endio_meta_workers);
2589 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2590 btrfs_stop_workers(&fs_info->endio_write_workers);
2591 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2592 btrfs_stop_workers(&fs_info->submit_workers);
2593
2594 btrfs_close_devices(fs_info->fs_devices);
2595 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2596
2597 bdi_destroy(&fs_info->bdi);
2598 cleanup_srcu_struct(&fs_info->subvol_srcu);
2599
2600 kfree(fs_info->extent_root);
2601 kfree(fs_info->tree_root);
2602 kfree(fs_info->chunk_root);
2603 kfree(fs_info->dev_root);
2604 kfree(fs_info->csum_root);
2605 kfree(fs_info);
2606
2607 return 0;
2608}
2609
2610int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2611{
2612 int ret;
2613 struct inode *btree_inode = buf->first_page->mapping->host;
2614
2615 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2616 NULL);
2617 if (!ret)
2618 return ret;
2619
2620 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2621 parent_transid);
2622 return !ret;
2623}
2624
2625int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2626{
2627 struct inode *btree_inode = buf->first_page->mapping->host;
2628 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2629 buf);
2630}
2631
2632void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2633{
2634 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2635 u64 transid = btrfs_header_generation(buf);
2636 struct inode *btree_inode = root->fs_info->btree_inode;
2637 int was_dirty;
2638
2639 btrfs_assert_tree_locked(buf);
2640 if (transid != root->fs_info->generation) {
2641 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2642 "found %llu running %llu\n",
2643 (unsigned long long)buf->start,
2644 (unsigned long long)transid,
2645 (unsigned long long)root->fs_info->generation);
2646 WARN_ON(1);
2647 }
2648 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2649 buf);
2650 if (!was_dirty) {
2651 spin_lock(&root->fs_info->delalloc_lock);
2652 root->fs_info->dirty_metadata_bytes += buf->len;
2653 spin_unlock(&root->fs_info->delalloc_lock);
2654 }
2655}
2656
2657void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2658{
2659 /*
2660 * looks as though older kernels can get into trouble with
2661 * this code, they end up stuck in balance_dirty_pages forever
2662 */
2663 u64 num_dirty;
2664 unsigned long thresh = 32 * 1024 * 1024;
2665
2666 if (current->flags & PF_MEMALLOC)
2667 return;
2668
2669 num_dirty = root->fs_info->dirty_metadata_bytes;
2670
2671 if (num_dirty > thresh) {
2672 balance_dirty_pages_ratelimited_nr(
2673 root->fs_info->btree_inode->i_mapping, 1);
2674 }
2675 return;
2676}
2677
2678int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2679{
2680 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2681 int ret;
2682 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2683 if (ret == 0)
2684 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2685 return ret;
2686}
2687
2688int btree_lock_page_hook(struct page *page)
2689{
2690 struct inode *inode = page->mapping->host;
2691 struct btrfs_root *root = BTRFS_I(inode)->root;
2692 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2693 struct extent_buffer *eb;
2694 unsigned long len;
2695 u64 bytenr = page_offset(page);
2696
2697 if (page->private == EXTENT_PAGE_PRIVATE)
2698 goto out;
2699
2700 len = page->private >> 2;
2701 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2702 if (!eb)
2703 goto out;
2704
2705 btrfs_tree_lock(eb);
2706 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2707
2708 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2709 spin_lock(&root->fs_info->delalloc_lock);
2710 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2711 root->fs_info->dirty_metadata_bytes -= eb->len;
2712 else
2713 WARN_ON(1);
2714 spin_unlock(&root->fs_info->delalloc_lock);
2715 }
2716
2717 btrfs_tree_unlock(eb);
2718 free_extent_buffer(eb);
2719out:
2720 lock_page(page);
2721 return 0;
2722}
2723
2724static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2725 int read_only)
2726{
2727 if (read_only)
2728 return;
2729
2730 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2731 printk(KERN_WARNING "warning: mount fs with errors, "
2732 "running btrfsck is recommended\n");
2733}
2734
2735int btrfs_error_commit_super(struct btrfs_root *root)
2736{
2737 int ret;
2738
2739 mutex_lock(&root->fs_info->cleaner_mutex);
2740 btrfs_run_delayed_iputs(root);
2741 mutex_unlock(&root->fs_info->cleaner_mutex);
2742
2743 down_write(&root->fs_info->cleanup_work_sem);
2744 up_write(&root->fs_info->cleanup_work_sem);
2745
2746 /* cleanup FS via transaction */
2747 btrfs_cleanup_transaction(root);
2748
2749 ret = write_ctree_super(NULL, root, 0);
2750
2751 return ret;
2752}
2753
2754static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2755{
2756 struct btrfs_inode *btrfs_inode;
2757 struct list_head splice;
2758
2759 INIT_LIST_HEAD(&splice);
2760
2761 mutex_lock(&root->fs_info->ordered_operations_mutex);
2762 spin_lock(&root->fs_info->ordered_extent_lock);
2763
2764 list_splice_init(&root->fs_info->ordered_operations, &splice);
2765 while (!list_empty(&splice)) {
2766 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2767 ordered_operations);
2768
2769 list_del_init(&btrfs_inode->ordered_operations);
2770
2771 btrfs_invalidate_inodes(btrfs_inode->root);
2772 }
2773
2774 spin_unlock(&root->fs_info->ordered_extent_lock);
2775 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2776
2777 return 0;
2778}
2779
2780static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2781{
2782 struct list_head splice;
2783 struct btrfs_ordered_extent *ordered;
2784 struct inode *inode;
2785
2786 INIT_LIST_HEAD(&splice);
2787
2788 spin_lock(&root->fs_info->ordered_extent_lock);
2789
2790 list_splice_init(&root->fs_info->ordered_extents, &splice);
2791 while (!list_empty(&splice)) {
2792 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2793 root_extent_list);
2794
2795 list_del_init(&ordered->root_extent_list);
2796 atomic_inc(&ordered->refs);
2797
2798 /* the inode may be getting freed (in sys_unlink path). */
2799 inode = igrab(ordered->inode);
2800
2801 spin_unlock(&root->fs_info->ordered_extent_lock);
2802 if (inode)
2803 iput(inode);
2804
2805 atomic_set(&ordered->refs, 1);
2806 btrfs_put_ordered_extent(ordered);
2807
2808 spin_lock(&root->fs_info->ordered_extent_lock);
2809 }
2810
2811 spin_unlock(&root->fs_info->ordered_extent_lock);
2812
2813 return 0;
2814}
2815
2816static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2817 struct btrfs_root *root)
2818{
2819 struct rb_node *node;
2820 struct btrfs_delayed_ref_root *delayed_refs;
2821 struct btrfs_delayed_ref_node *ref;
2822 int ret = 0;
2823
2824 delayed_refs = &trans->delayed_refs;
2825
2826 spin_lock(&delayed_refs->lock);
2827 if (delayed_refs->num_entries == 0) {
2828 spin_unlock(&delayed_refs->lock);
2829 printk(KERN_INFO "delayed_refs has NO entry\n");
2830 return ret;
2831 }
2832
2833 node = rb_first(&delayed_refs->root);
2834 while (node) {
2835 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2836 node = rb_next(node);
2837
2838 ref->in_tree = 0;
2839 rb_erase(&ref->rb_node, &delayed_refs->root);
2840 delayed_refs->num_entries--;
2841
2842 atomic_set(&ref->refs, 1);
2843 if (btrfs_delayed_ref_is_head(ref)) {
2844 struct btrfs_delayed_ref_head *head;
2845
2846 head = btrfs_delayed_node_to_head(ref);
2847 mutex_lock(&head->mutex);
2848 kfree(head->extent_op);
2849 delayed_refs->num_heads--;
2850 if (list_empty(&head->cluster))
2851 delayed_refs->num_heads_ready--;
2852 list_del_init(&head->cluster);
2853 mutex_unlock(&head->mutex);
2854 }
2855
2856 spin_unlock(&delayed_refs->lock);
2857 btrfs_put_delayed_ref(ref);
2858
2859 cond_resched();
2860 spin_lock(&delayed_refs->lock);
2861 }
2862
2863 spin_unlock(&delayed_refs->lock);
2864
2865 return ret;
2866}
2867
2868static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2869{
2870 struct btrfs_pending_snapshot *snapshot;
2871 struct list_head splice;
2872
2873 INIT_LIST_HEAD(&splice);
2874
2875 list_splice_init(&t->pending_snapshots, &splice);
2876
2877 while (!list_empty(&splice)) {
2878 snapshot = list_entry(splice.next,
2879 struct btrfs_pending_snapshot,
2880 list);
2881
2882 list_del_init(&snapshot->list);
2883
2884 kfree(snapshot);
2885 }
2886
2887 return 0;
2888}
2889
2890static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2891{
2892 struct btrfs_inode *btrfs_inode;
2893 struct list_head splice;
2894
2895 INIT_LIST_HEAD(&splice);
2896
2897 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2898
2899 spin_lock(&root->fs_info->delalloc_lock);
2900
2901 while (!list_empty(&splice)) {
2902 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2903 delalloc_inodes);
2904
2905 list_del_init(&btrfs_inode->delalloc_inodes);
2906
2907 btrfs_invalidate_inodes(btrfs_inode->root);
2908 }
2909
2910 spin_unlock(&root->fs_info->delalloc_lock);
2911
2912 return 0;
2913}
2914
2915static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2916 struct extent_io_tree *dirty_pages,
2917 int mark)
2918{
2919 int ret;
2920 struct page *page;
2921 struct inode *btree_inode = root->fs_info->btree_inode;
2922 struct extent_buffer *eb;
2923 u64 start = 0;
2924 u64 end;
2925 u64 offset;
2926 unsigned long index;
2927
2928 while (1) {
2929 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2930 mark);
2931 if (ret)
2932 break;
2933
2934 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2935 while (start <= end) {
2936 index = start >> PAGE_CACHE_SHIFT;
2937 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2938 page = find_get_page(btree_inode->i_mapping, index);
2939 if (!page)
2940 continue;
2941 offset = page_offset(page);
2942
2943 spin_lock(&dirty_pages->buffer_lock);
2944 eb = radix_tree_lookup(
2945 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2946 offset >> PAGE_CACHE_SHIFT);
2947 spin_unlock(&dirty_pages->buffer_lock);
2948 if (eb) {
2949 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2950 &eb->bflags);
2951 atomic_set(&eb->refs, 1);
2952 }
2953 if (PageWriteback(page))
2954 end_page_writeback(page);
2955
2956 lock_page(page);
2957 if (PageDirty(page)) {
2958 clear_page_dirty_for_io(page);
2959 spin_lock_irq(&page->mapping->tree_lock);
2960 radix_tree_tag_clear(&page->mapping->page_tree,
2961 page_index(page),
2962 PAGECACHE_TAG_DIRTY);
2963 spin_unlock_irq(&page->mapping->tree_lock);
2964 }
2965
2966 page->mapping->a_ops->invalidatepage(page, 0);
2967 unlock_page(page);
2968 }
2969 }
2970
2971 return ret;
2972}
2973
2974static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
2975 struct extent_io_tree *pinned_extents)
2976{
2977 struct extent_io_tree *unpin;
2978 u64 start;
2979 u64 end;
2980 int ret;
2981
2982 unpin = pinned_extents;
2983 while (1) {
2984 ret = find_first_extent_bit(unpin, 0, &start, &end,
2985 EXTENT_DIRTY);
2986 if (ret)
2987 break;
2988
2989 /* opt_discard */
2990 if (btrfs_test_opt(root, DISCARD))
2991 ret = btrfs_error_discard_extent(root, start,
2992 end + 1 - start,
2993 NULL);
2994
2995 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2996 btrfs_error_unpin_extent_range(root, start, end);
2997 cond_resched();
2998 }
2999
3000 return 0;
3001}
3002
3003static int btrfs_cleanup_transaction(struct btrfs_root *root)
3004{
3005 struct btrfs_transaction *t;
3006 LIST_HEAD(list);
3007
3008 WARN_ON(1);
3009
3010 mutex_lock(&root->fs_info->trans_mutex);
3011 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3012
3013 list_splice_init(&root->fs_info->trans_list, &list);
3014 while (!list_empty(&list)) {
3015 t = list_entry(list.next, struct btrfs_transaction, list);
3016 if (!t)
3017 break;
3018
3019 btrfs_destroy_ordered_operations(root);
3020
3021 btrfs_destroy_ordered_extents(root);
3022
3023 btrfs_destroy_delayed_refs(t, root);
3024
3025 btrfs_block_rsv_release(root,
3026 &root->fs_info->trans_block_rsv,
3027 t->dirty_pages.dirty_bytes);
3028
3029 /* FIXME: cleanup wait for commit */
3030 t->in_commit = 1;
3031 t->blocked = 1;
3032 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3033 wake_up(&root->fs_info->transaction_blocked_wait);
3034
3035 t->blocked = 0;
3036 if (waitqueue_active(&root->fs_info->transaction_wait))
3037 wake_up(&root->fs_info->transaction_wait);
3038 mutex_unlock(&root->fs_info->trans_mutex);
3039
3040 mutex_lock(&root->fs_info->trans_mutex);
3041 t->commit_done = 1;
3042 if (waitqueue_active(&t->commit_wait))
3043 wake_up(&t->commit_wait);
3044 mutex_unlock(&root->fs_info->trans_mutex);
3045
3046 mutex_lock(&root->fs_info->trans_mutex);
3047
3048 btrfs_destroy_pending_snapshots(t);
3049
3050 btrfs_destroy_delalloc_inodes(root);
3051
3052 spin_lock(&root->fs_info->new_trans_lock);
3053 root->fs_info->running_transaction = NULL;
3054 spin_unlock(&root->fs_info->new_trans_lock);
3055
3056 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3057 EXTENT_DIRTY);
3058
3059 btrfs_destroy_pinned_extent(root,
3060 root->fs_info->pinned_extents);
3061
3062 atomic_set(&t->use_count, 0);
3063 list_del_init(&t->list);
3064 memset(t, 0, sizeof(*t));
3065 kmem_cache_free(btrfs_transaction_cachep, t);
3066 }
3067
3068 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3069 mutex_unlock(&root->fs_info->trans_mutex);
3070
3071 return 0;
3072}
3073
3074static struct extent_io_ops btree_extent_io_ops = {
3075 .write_cache_pages_lock_hook = btree_lock_page_hook,
3076 .readpage_end_io_hook = btree_readpage_end_io_hook,
3077 .submit_bio_hook = btree_submit_bio_hook,
3078 /* note we're sharing with inode.c for the merge bio hook */
3079 .merge_bio_hook = btrfs_merge_bio_hook,
3080};
Linux kernel - Deliverables
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