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btrfs: fix possible deadlock by clearing __GFP_FS flag
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / disk-io.c
blob5cf3aa7b125c2686304b4bc2ec0449af33566166
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
45 static struct extent_io_ops btree_extent_io_ops;
46 static void end_workqueue_fn(struct btrfs_work *work);
47 static void free_fs_root(struct btrfs_root *root);
48 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
49 int read_only);
50 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
51 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
52 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
53 struct btrfs_root *root);
54 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
55 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
56 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
57 struct extent_io_tree *dirty_pages,
58 int mark);
59 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
60 struct extent_io_tree *pinned_extents);
61 static 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 */
68 struct 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 */
84 struct 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
119 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
120 static 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 */
139 static struct extent_map *btree_get_extent(struct inode *inode,
140 struct page *page, size_t page_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);
191 out:
192 return em;
193 }
194
195 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
196 {
197 return crc32c(seed, data, len);
198 }
199
200 void 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 */
209 static 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 */
283 static int verify_parent_transid(struct extent_io_tree *io_tree,
284 struct extent_buffer *eb, u64 parent_transid)
285 {
286 struct extent_state *cached_state = NULL;
287 int ret;
288
289 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
290 return 0;
291
292 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
293 0, &cached_state, GFP_NOFS);
294 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
295 btrfs_header_generation(eb) == parent_transid) {
296 ret = 0;
297 goto out;
298 }
299 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);
308 out:
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 */
318 static 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
361 static 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);
407 err:
408 free_extent_buffer(eb);
409 out:
410 return 0;
411 }
412
413 static 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
438 static 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
500 void 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
508 static 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;
582 err:
583 free_extent_buffer(eb);
584 out:
585 return ret;
586 }
587
588 static 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 */
625 int 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
645 unsigned 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
653 int 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
659 static 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
669 static 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
692 static 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
700 int 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
744 static 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
760 static 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
773 static 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
784 static 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
815 static 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
835 static 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
864 static 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
885 static 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
892 static 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
918 static 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
933 static 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 .sync_page = block_sync_page,
940 #ifdef CONFIG_MIGRATION
941 .migratepage = btree_migratepage,
942 #endif
943 };
944
945 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
946 u64 parent_transid)
947 {
948 struct extent_buffer *buf = NULL;
949 struct inode *btree_inode = root->fs_info->btree_inode;
950 int ret = 0;
951
952 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
953 if (!buf)
954 return 0;
955 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
956 buf, 0, 0, btree_get_extent, 0);
957 free_extent_buffer(buf);
958 return ret;
959 }
960
961 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
962 u64 bytenr, u32 blocksize)
963 {
964 struct inode *btree_inode = root->fs_info->btree_inode;
965 struct extent_buffer *eb;
966 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
967 bytenr, blocksize, GFP_NOFS);
968 return eb;
969 }
970
971 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
972 u64 bytenr, u32 blocksize)
973 {
974 struct inode *btree_inode = root->fs_info->btree_inode;
975 struct extent_buffer *eb;
976
977 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
978 bytenr, blocksize, NULL, GFP_NOFS);
979 return eb;
980 }
981
982
983 int btrfs_write_tree_block(struct extent_buffer *buf)
984 {
985 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
986 buf->start + buf->len - 1);
987 }
988
989 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
990 {
991 return filemap_fdatawait_range(buf->first_page->mapping,
992 buf->start, buf->start + buf->len - 1);
993 }
994
995 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
996 u32 blocksize, u64 parent_transid)
997 {
998 struct extent_buffer *buf = NULL;
999 int ret;
1000
1001 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1002 if (!buf)
1003 return NULL;
1004
1005 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1006
1007 if (ret == 0)
1008 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1009 return buf;
1010
1011 }
1012
1013 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1014 struct extent_buffer *buf)
1015 {
1016 struct inode *btree_inode = root->fs_info->btree_inode;
1017 if (btrfs_header_generation(buf) ==
1018 root->fs_info->running_transaction->transid) {
1019 btrfs_assert_tree_locked(buf);
1020
1021 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1022 spin_lock(&root->fs_info->delalloc_lock);
1023 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1024 root->fs_info->dirty_metadata_bytes -= buf->len;
1025 else
1026 WARN_ON(1);
1027 spin_unlock(&root->fs_info->delalloc_lock);
1028 }
1029
1030 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1031 btrfs_set_lock_blocking(buf);
1032 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1033 buf);
1034 }
1035 return 0;
1036 }
1037
1038 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1039 u32 stripesize, struct btrfs_root *root,
1040 struct btrfs_fs_info *fs_info,
1041 u64 objectid)
1042 {
1043 root->node = NULL;
1044 root->commit_root = NULL;
1045 root->sectorsize = sectorsize;
1046 root->nodesize = nodesize;
1047 root->leafsize = leafsize;
1048 root->stripesize = stripesize;
1049 root->ref_cows = 0;
1050 root->track_dirty = 0;
1051 root->in_radix = 0;
1052 root->orphan_item_inserted = 0;
1053 root->orphan_cleanup_state = 0;
1054
1055 root->fs_info = fs_info;
1056 root->objectid = objectid;
1057 root->last_trans = 0;
1058 root->highest_objectid = 0;
1059 root->name = NULL;
1060 root->in_sysfs = 0;
1061 root->inode_tree = RB_ROOT;
1062 root->block_rsv = NULL;
1063 root->orphan_block_rsv = NULL;
1064
1065 INIT_LIST_HEAD(&root->dirty_list);
1066 INIT_LIST_HEAD(&root->orphan_list);
1067 INIT_LIST_HEAD(&root->root_list);
1068 spin_lock_init(&root->node_lock);
1069 spin_lock_init(&root->orphan_lock);
1070 spin_lock_init(&root->inode_lock);
1071 spin_lock_init(&root->accounting_lock);
1072 mutex_init(&root->objectid_mutex);
1073 mutex_init(&root->log_mutex);
1074 init_waitqueue_head(&root->log_writer_wait);
1075 init_waitqueue_head(&root->log_commit_wait[0]);
1076 init_waitqueue_head(&root->log_commit_wait[1]);
1077 atomic_set(&root->log_commit[0], 0);
1078 atomic_set(&root->log_commit[1], 0);
1079 atomic_set(&root->log_writers, 0);
1080 root->log_batch = 0;
1081 root->log_transid = 0;
1082 root->last_log_commit = 0;
1083 extent_io_tree_init(&root->dirty_log_pages,
1084 fs_info->btree_inode->i_mapping, GFP_NOFS);
1085
1086 memset(&root->root_key, 0, sizeof(root->root_key));
1087 memset(&root->root_item, 0, sizeof(root->root_item));
1088 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1089 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1090 root->defrag_trans_start = fs_info->generation;
1091 init_completion(&root->kobj_unregister);
1092 root->defrag_running = 0;
1093 root->root_key.objectid = objectid;
1094 root->anon_super.s_root = NULL;
1095 root->anon_super.s_dev = 0;
1096 INIT_LIST_HEAD(&root->anon_super.s_list);
1097 INIT_LIST_HEAD(&root->anon_super.s_instances);
1098 init_rwsem(&root->anon_super.s_umount);
1099
1100 return 0;
1101 }
1102
1103 static int find_and_setup_root(struct btrfs_root *tree_root,
1104 struct btrfs_fs_info *fs_info,
1105 u64 objectid,
1106 struct btrfs_root *root)
1107 {
1108 int ret;
1109 u32 blocksize;
1110 u64 generation;
1111
1112 __setup_root(tree_root->nodesize, tree_root->leafsize,
1113 tree_root->sectorsize, tree_root->stripesize,
1114 root, fs_info, objectid);
1115 ret = btrfs_find_last_root(tree_root, objectid,
1116 &root->root_item, &root->root_key);
1117 if (ret > 0)
1118 return -ENOENT;
1119 BUG_ON(ret);
1120
1121 generation = btrfs_root_generation(&root->root_item);
1122 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1123 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1124 blocksize, generation);
1125 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1126 free_extent_buffer(root->node);
1127 return -EIO;
1128 }
1129 root->commit_root = btrfs_root_node(root);
1130 return 0;
1131 }
1132
1133 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1134 struct btrfs_fs_info *fs_info)
1135 {
1136 struct btrfs_root *root;
1137 struct btrfs_root *tree_root = fs_info->tree_root;
1138 struct extent_buffer *leaf;
1139
1140 root = kzalloc(sizeof(*root), GFP_NOFS);
1141 if (!root)
1142 return ERR_PTR(-ENOMEM);
1143
1144 __setup_root(tree_root->nodesize, tree_root->leafsize,
1145 tree_root->sectorsize, tree_root->stripesize,
1146 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1147
1148 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1149 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1150 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1151 /*
1152 * log trees do not get reference counted because they go away
1153 * before a real commit is actually done. They do store pointers
1154 * to file data extents, and those reference counts still get
1155 * updated (along with back refs to the log tree).
1156 */
1157 root->ref_cows = 0;
1158
1159 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1160 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1161 if (IS_ERR(leaf)) {
1162 kfree(root);
1163 return ERR_CAST(leaf);
1164 }
1165
1166 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1167 btrfs_set_header_bytenr(leaf, leaf->start);
1168 btrfs_set_header_generation(leaf, trans->transid);
1169 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1170 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1171 root->node = leaf;
1172
1173 write_extent_buffer(root->node, root->fs_info->fsid,
1174 (unsigned long)btrfs_header_fsid(root->node),
1175 BTRFS_FSID_SIZE);
1176 btrfs_mark_buffer_dirty(root->node);
1177 btrfs_tree_unlock(root->node);
1178 return root;
1179 }
1180
1181 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1182 struct btrfs_fs_info *fs_info)
1183 {
1184 struct btrfs_root *log_root;
1185
1186 log_root = alloc_log_tree(trans, fs_info);
1187 if (IS_ERR(log_root))
1188 return PTR_ERR(log_root);
1189 WARN_ON(fs_info->log_root_tree);
1190 fs_info->log_root_tree = log_root;
1191 return 0;
1192 }
1193
1194 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1195 struct btrfs_root *root)
1196 {
1197 struct btrfs_root *log_root;
1198 struct btrfs_inode_item *inode_item;
1199
1200 log_root = alloc_log_tree(trans, root->fs_info);
1201 if (IS_ERR(log_root))
1202 return PTR_ERR(log_root);
1203
1204 log_root->last_trans = trans->transid;
1205 log_root->root_key.offset = root->root_key.objectid;
1206
1207 inode_item = &log_root->root_item.inode;
1208 inode_item->generation = cpu_to_le64(1);
1209 inode_item->size = cpu_to_le64(3);
1210 inode_item->nlink = cpu_to_le32(1);
1211 inode_item->nbytes = cpu_to_le64(root->leafsize);
1212 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1213
1214 btrfs_set_root_node(&log_root->root_item, log_root->node);
1215
1216 WARN_ON(root->log_root);
1217 root->log_root = log_root;
1218 root->log_transid = 0;
1219 root->last_log_commit = 0;
1220 return 0;
1221 }
1222
1223 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1224 struct btrfs_key *location)
1225 {
1226 struct btrfs_root *root;
1227 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1228 struct btrfs_path *path;
1229 struct extent_buffer *l;
1230 u64 generation;
1231 u32 blocksize;
1232 int ret = 0;
1233
1234 root = kzalloc(sizeof(*root), GFP_NOFS);
1235 if (!root)
1236 return ERR_PTR(-ENOMEM);
1237 if (location->offset == (u64)-1) {
1238 ret = find_and_setup_root(tree_root, fs_info,
1239 location->objectid, root);
1240 if (ret) {
1241 kfree(root);
1242 return ERR_PTR(ret);
1243 }
1244 goto out;
1245 }
1246
1247 __setup_root(tree_root->nodesize, tree_root->leafsize,
1248 tree_root->sectorsize, tree_root->stripesize,
1249 root, fs_info, location->objectid);
1250
1251 path = btrfs_alloc_path();
1252 if (!path) {
1253 kfree(root);
1254 return ERR_PTR(-ENOMEM);
1255 }
1256 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1257 if (ret == 0) {
1258 l = path->nodes[0];
1259 read_extent_buffer(l, &root->root_item,
1260 btrfs_item_ptr_offset(l, path->slots[0]),
1261 sizeof(root->root_item));
1262 memcpy(&root->root_key, location, sizeof(*location));
1263 }
1264 btrfs_free_path(path);
1265 if (ret) {
1266 kfree(root);
1267 if (ret > 0)
1268 ret = -ENOENT;
1269 return ERR_PTR(ret);
1270 }
1271
1272 generation = btrfs_root_generation(&root->root_item);
1273 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1274 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1275 blocksize, generation);
1276 root->commit_root = btrfs_root_node(root);
1277 BUG_ON(!root->node);
1278 out:
1279 if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
1280 root->ref_cows = 1;
1281
1282 return root;
1283 }
1284
1285 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1286 u64 root_objectid)
1287 {
1288 struct btrfs_root *root;
1289
1290 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1291 return fs_info->tree_root;
1292 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1293 return fs_info->extent_root;
1294
1295 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1296 (unsigned long)root_objectid);
1297 return root;
1298 }
1299
1300 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1301 struct btrfs_key *location)
1302 {
1303 struct btrfs_root *root;
1304 int ret;
1305
1306 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1307 return fs_info->tree_root;
1308 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1309 return fs_info->extent_root;
1310 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1311 return fs_info->chunk_root;
1312 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1313 return fs_info->dev_root;
1314 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1315 return fs_info->csum_root;
1316 again:
1317 spin_lock(&fs_info->fs_roots_radix_lock);
1318 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1319 (unsigned long)location->objectid);
1320 spin_unlock(&fs_info->fs_roots_radix_lock);
1321 if (root)
1322 return root;
1323
1324 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1325 if (IS_ERR(root))
1326 return root;
1327
1328 set_anon_super(&root->anon_super, NULL);
1329
1330 if (btrfs_root_refs(&root->root_item) == 0) {
1331 ret = -ENOENT;
1332 goto fail;
1333 }
1334
1335 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1336 if (ret < 0)
1337 goto fail;
1338 if (ret == 0)
1339 root->orphan_item_inserted = 1;
1340
1341 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1342 if (ret)
1343 goto fail;
1344
1345 spin_lock(&fs_info->fs_roots_radix_lock);
1346 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1347 (unsigned long)root->root_key.objectid,
1348 root);
1349 if (ret == 0)
1350 root->in_radix = 1;
1351
1352 spin_unlock(&fs_info->fs_roots_radix_lock);
1353 radix_tree_preload_end();
1354 if (ret) {
1355 if (ret == -EEXIST) {
1356 free_fs_root(root);
1357 goto again;
1358 }
1359 goto fail;
1360 }
1361
1362 ret = btrfs_find_dead_roots(fs_info->tree_root,
1363 root->root_key.objectid);
1364 WARN_ON(ret);
1365 return root;
1366 fail:
1367 free_fs_root(root);
1368 return ERR_PTR(ret);
1369 }
1370
1371 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1372 struct btrfs_key *location,
1373 const char *name, int namelen)
1374 {
1375 return btrfs_read_fs_root_no_name(fs_info, location);
1376 #if 0
1377 struct btrfs_root *root;
1378 int ret;
1379
1380 root = btrfs_read_fs_root_no_name(fs_info, location);
1381 if (!root)
1382 return NULL;
1383
1384 if (root->in_sysfs)
1385 return root;
1386
1387 ret = btrfs_set_root_name(root, name, namelen);
1388 if (ret) {
1389 free_extent_buffer(root->node);
1390 kfree(root);
1391 return ERR_PTR(ret);
1392 }
1393
1394 ret = btrfs_sysfs_add_root(root);
1395 if (ret) {
1396 free_extent_buffer(root->node);
1397 kfree(root->name);
1398 kfree(root);
1399 return ERR_PTR(ret);
1400 }
1401 root->in_sysfs = 1;
1402 return root;
1403 #endif
1404 }
1405
1406 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1407 {
1408 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1409 int ret = 0;
1410 struct btrfs_device *device;
1411 struct backing_dev_info *bdi;
1412
1413 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1414 if (!device->bdev)
1415 continue;
1416 bdi = blk_get_backing_dev_info(device->bdev);
1417 if (bdi && bdi_congested(bdi, bdi_bits)) {
1418 ret = 1;
1419 break;
1420 }
1421 }
1422 return ret;
1423 }
1424
1425 /*
1426 * this unplugs every device on the box, and it is only used when page
1427 * is null
1428 */
1429 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1430 {
1431 struct btrfs_device *device;
1432 struct btrfs_fs_info *info;
1433
1434 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1435 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1436 if (!device->bdev)
1437 continue;
1438
1439 bdi = blk_get_backing_dev_info(device->bdev);
1440 if (bdi->unplug_io_fn)
1441 bdi->unplug_io_fn(bdi, page);
1442 }
1443 }
1444
1445 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1446 {
1447 struct inode *inode;
1448 struct extent_map_tree *em_tree;
1449 struct extent_map *em;
1450 struct address_space *mapping;
1451 u64 offset;
1452
1453 /* the generic O_DIRECT read code does this */
1454 if (1 || !page) {
1455 __unplug_io_fn(bdi, page);
1456 return;
1457 }
1458
1459 /*
1460 * page->mapping may change at any time. Get a consistent copy
1461 * and use that for everything below
1462 */
1463 smp_mb();
1464 mapping = page->mapping;
1465 if (!mapping)
1466 return;
1467
1468 inode = mapping->host;
1469
1470 /*
1471 * don't do the expensive searching for a small number of
1472 * devices
1473 */
1474 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1475 __unplug_io_fn(bdi, page);
1476 return;
1477 }
1478
1479 offset = page_offset(page);
1480
1481 em_tree = &BTRFS_I(inode)->extent_tree;
1482 read_lock(&em_tree->lock);
1483 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1484 read_unlock(&em_tree->lock);
1485 if (!em) {
1486 __unplug_io_fn(bdi, page);
1487 return;
1488 }
1489
1490 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1491 free_extent_map(em);
1492 __unplug_io_fn(bdi, page);
1493 return;
1494 }
1495 offset = offset - em->start;
1496 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1497 em->block_start + offset, page);
1498 free_extent_map(em);
1499 }
1500
1501 /*
1502 * If this fails, caller must call bdi_destroy() to get rid of the
1503 * bdi again.
1504 */
1505 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1506 {
1507 int err;
1508
1509 bdi->capabilities = BDI_CAP_MAP_COPY;
1510 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1511 if (err)
1512 return err;
1513
1514 bdi->ra_pages = default_backing_dev_info.ra_pages;
1515 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1516 bdi->unplug_io_data = info;
1517 bdi->congested_fn = btrfs_congested_fn;
1518 bdi->congested_data = info;
1519 return 0;
1520 }
1521
1522 static int bio_ready_for_csum(struct bio *bio)
1523 {
1524 u64 length = 0;
1525 u64 buf_len = 0;
1526 u64 start = 0;
1527 struct page *page;
1528 struct extent_io_tree *io_tree = NULL;
1529 struct bio_vec *bvec;
1530 int i;
1531 int ret;
1532
1533 bio_for_each_segment(bvec, bio, i) {
1534 page = bvec->bv_page;
1535 if (page->private == EXTENT_PAGE_PRIVATE) {
1536 length += bvec->bv_len;
1537 continue;
1538 }
1539 if (!page->private) {
1540 length += bvec->bv_len;
1541 continue;
1542 }
1543 length = bvec->bv_len;
1544 buf_len = page->private >> 2;
1545 start = page_offset(page) + bvec->bv_offset;
1546 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1547 }
1548 /* are we fully contained in this bio? */
1549 if (buf_len <= length)
1550 return 1;
1551
1552 ret = extent_range_uptodate(io_tree, start + length,
1553 start + buf_len - 1);
1554 return ret;
1555 }
1556
1557 /*
1558 * called by the kthread helper functions to finally call the bio end_io
1559 * functions. This is where read checksum verification actually happens
1560 */
1561 static void end_workqueue_fn(struct btrfs_work *work)
1562 {
1563 struct bio *bio;
1564 struct end_io_wq *end_io_wq;
1565 struct btrfs_fs_info *fs_info;
1566 int error;
1567
1568 end_io_wq = container_of(work, struct end_io_wq, work);
1569 bio = end_io_wq->bio;
1570 fs_info = end_io_wq->info;
1571
1572 /* metadata bio reads are special because the whole tree block must
1573 * be checksummed at once. This makes sure the entire block is in
1574 * ram and up to date before trying to verify things. For
1575 * blocksize <= pagesize, it is basically a noop
1576 */
1577 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1578 !bio_ready_for_csum(bio)) {
1579 btrfs_queue_worker(&fs_info->endio_meta_workers,
1580 &end_io_wq->work);
1581 return;
1582 }
1583 error = end_io_wq->error;
1584 bio->bi_private = end_io_wq->private;
1585 bio->bi_end_io = end_io_wq->end_io;
1586 kfree(end_io_wq);
1587 bio_endio(bio, error);
1588 }
1589
1590 static int cleaner_kthread(void *arg)
1591 {
1592 struct btrfs_root *root = arg;
1593
1594 do {
1595 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1596
1597 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1598 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1599 btrfs_run_delayed_iputs(root);
1600 btrfs_clean_old_snapshots(root);
1601 mutex_unlock(&root->fs_info->cleaner_mutex);
1602 }
1603
1604 if (freezing(current)) {
1605 refrigerator();
1606 } else {
1607 set_current_state(TASK_INTERRUPTIBLE);
1608 if (!kthread_should_stop())
1609 schedule();
1610 __set_current_state(TASK_RUNNING);
1611 }
1612 } while (!kthread_should_stop());
1613 return 0;
1614 }
1615
1616 static int transaction_kthread(void *arg)
1617 {
1618 struct btrfs_root *root = arg;
1619 struct btrfs_trans_handle *trans;
1620 struct btrfs_transaction *cur;
1621 u64 transid;
1622 unsigned long now;
1623 unsigned long delay;
1624 int ret;
1625
1626 do {
1627 delay = HZ * 30;
1628 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1629 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1630
1631 spin_lock(&root->fs_info->new_trans_lock);
1632 cur = root->fs_info->running_transaction;
1633 if (!cur) {
1634 spin_unlock(&root->fs_info->new_trans_lock);
1635 goto sleep;
1636 }
1637
1638 now = get_seconds();
1639 if (!cur->blocked &&
1640 (now < cur->start_time || now - cur->start_time < 30)) {
1641 spin_unlock(&root->fs_info->new_trans_lock);
1642 delay = HZ * 5;
1643 goto sleep;
1644 }
1645 transid = cur->transid;
1646 spin_unlock(&root->fs_info->new_trans_lock);
1647
1648 trans = btrfs_join_transaction(root, 1);
1649 BUG_ON(IS_ERR(trans));
1650 if (transid == trans->transid) {
1651 ret = btrfs_commit_transaction(trans, root);
1652 BUG_ON(ret);
1653 } else {
1654 btrfs_end_transaction(trans, root);
1655 }
1656 sleep:
1657 wake_up_process(root->fs_info->cleaner_kthread);
1658 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1659
1660 if (freezing(current)) {
1661 refrigerator();
1662 } else {
1663 set_current_state(TASK_INTERRUPTIBLE);
1664 if (!kthread_should_stop() &&
1665 !btrfs_transaction_blocked(root->fs_info))
1666 schedule_timeout(delay);
1667 __set_current_state(TASK_RUNNING);
1668 }
1669 } while (!kthread_should_stop());
1670 return 0;
1671 }
1672
1673 struct btrfs_root *open_ctree(struct super_block *sb,
1674 struct btrfs_fs_devices *fs_devices,
1675 char *options)
1676 {
1677 u32 sectorsize;
1678 u32 nodesize;
1679 u32 leafsize;
1680 u32 blocksize;
1681 u32 stripesize;
1682 u64 generation;
1683 u64 features;
1684 struct btrfs_key location;
1685 struct buffer_head *bh;
1686 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1687 GFP_NOFS);
1688 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1689 GFP_NOFS);
1690 struct btrfs_root *tree_root = btrfs_sb(sb);
1691 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1692 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1693 GFP_NOFS);
1694 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1695 GFP_NOFS);
1696 struct btrfs_root *log_tree_root;
1697
1698 int ret;
1699 int err = -EINVAL;
1700
1701 struct btrfs_super_block *disk_super;
1702
1703 if (!extent_root || !tree_root || !fs_info ||
1704 !chunk_root || !dev_root || !csum_root) {
1705 err = -ENOMEM;
1706 goto fail;
1707 }
1708
1709 ret = init_srcu_struct(&fs_info->subvol_srcu);
1710 if (ret) {
1711 err = ret;
1712 goto fail;
1713 }
1714
1715 ret = setup_bdi(fs_info, &fs_info->bdi);
1716 if (ret) {
1717 err = ret;
1718 goto fail_srcu;
1719 }
1720
1721 fs_info->btree_inode = new_inode(sb);
1722 if (!fs_info->btree_inode) {
1723 err = -ENOMEM;
1724 goto fail_bdi;
1725 }
1726
1727 fs_info->btree_inode->i_mapping->flags &= ~__GFP_FS;
1728
1729 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1730 INIT_LIST_HEAD(&fs_info->trans_list);
1731 INIT_LIST_HEAD(&fs_info->dead_roots);
1732 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1733 INIT_LIST_HEAD(&fs_info->hashers);
1734 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1735 INIT_LIST_HEAD(&fs_info->ordered_operations);
1736 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1737 spin_lock_init(&fs_info->delalloc_lock);
1738 spin_lock_init(&fs_info->new_trans_lock);
1739 spin_lock_init(&fs_info->ref_cache_lock);
1740 spin_lock_init(&fs_info->fs_roots_radix_lock);
1741 spin_lock_init(&fs_info->delayed_iput_lock);
1742
1743 init_completion(&fs_info->kobj_unregister);
1744 fs_info->tree_root = tree_root;
1745 fs_info->extent_root = extent_root;
1746 fs_info->csum_root = csum_root;
1747 fs_info->chunk_root = chunk_root;
1748 fs_info->dev_root = dev_root;
1749 fs_info->fs_devices = fs_devices;
1750 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1751 INIT_LIST_HEAD(&fs_info->space_info);
1752 btrfs_mapping_init(&fs_info->mapping_tree);
1753 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1754 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1755 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1756 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1757 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1758 INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1759 mutex_init(&fs_info->durable_block_rsv_mutex);
1760 atomic_set(&fs_info->nr_async_submits, 0);
1761 atomic_set(&fs_info->async_delalloc_pages, 0);
1762 atomic_set(&fs_info->async_submit_draining, 0);
1763 atomic_set(&fs_info->nr_async_bios, 0);
1764 fs_info->sb = sb;
1765 fs_info->max_inline = 8192 * 1024;
1766 fs_info->metadata_ratio = 0;
1767
1768 fs_info->thread_pool_size = min_t(unsigned long,
1769 num_online_cpus() + 2, 8);
1770
1771 INIT_LIST_HEAD(&fs_info->ordered_extents);
1772 spin_lock_init(&fs_info->ordered_extent_lock);
1773
1774 sb->s_blocksize = 4096;
1775 sb->s_blocksize_bits = blksize_bits(4096);
1776 sb->s_bdi = &fs_info->bdi;
1777
1778 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1779 fs_info->btree_inode->i_nlink = 1;
1780 /*
1781 * we set the i_size on the btree inode to the max possible int.
1782 * the real end of the address space is determined by all of
1783 * the devices in the system
1784 */
1785 fs_info->btree_inode->i_size = OFFSET_MAX;
1786 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1787 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1788
1789 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1790 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1791 fs_info->btree_inode->i_mapping,
1792 GFP_NOFS);
1793 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1794 GFP_NOFS);
1795
1796 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1797
1798 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1799 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1800 sizeof(struct btrfs_key));
1801 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1802 insert_inode_hash(fs_info->btree_inode);
1803
1804 spin_lock_init(&fs_info->block_group_cache_lock);
1805 fs_info->block_group_cache_tree = RB_ROOT;
1806
1807 extent_io_tree_init(&fs_info->freed_extents[0],
1808 fs_info->btree_inode->i_mapping, GFP_NOFS);
1809 extent_io_tree_init(&fs_info->freed_extents[1],
1810 fs_info->btree_inode->i_mapping, GFP_NOFS);
1811 fs_info->pinned_extents = &fs_info->freed_extents[0];
1812 fs_info->do_barriers = 1;
1813
1814
1815 mutex_init(&fs_info->trans_mutex);
1816 mutex_init(&fs_info->ordered_operations_mutex);
1817 mutex_init(&fs_info->tree_log_mutex);
1818 mutex_init(&fs_info->chunk_mutex);
1819 mutex_init(&fs_info->transaction_kthread_mutex);
1820 mutex_init(&fs_info->cleaner_mutex);
1821 mutex_init(&fs_info->volume_mutex);
1822 init_rwsem(&fs_info->extent_commit_sem);
1823 init_rwsem(&fs_info->cleanup_work_sem);
1824 init_rwsem(&fs_info->subvol_sem);
1825
1826 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1827 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1828
1829 init_waitqueue_head(&fs_info->transaction_throttle);
1830 init_waitqueue_head(&fs_info->transaction_wait);
1831 init_waitqueue_head(&fs_info->transaction_blocked_wait);
1832 init_waitqueue_head(&fs_info->async_submit_wait);
1833
1834 __setup_root(4096, 4096, 4096, 4096, tree_root,
1835 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1836
1837 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1838 if (!bh) {
1839 err = -EINVAL;
1840 goto fail_iput;
1841 }
1842
1843 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1844 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1845 sizeof(fs_info->super_for_commit));
1846 brelse(bh);
1847
1848 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1849
1850 disk_super = &fs_info->super_copy;
1851 if (!btrfs_super_root(disk_super))
1852 goto fail_iput;
1853
1854 /* check FS state, whether FS is broken. */
1855 fs_info->fs_state |= btrfs_super_flags(disk_super);
1856
1857 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1858
1859 /*
1860 * In the long term, we'll store the compression type in the super
1861 * block, and it'll be used for per file compression control.
1862 */
1863 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1864
1865 ret = btrfs_parse_options(tree_root, options);
1866 if (ret) {
1867 err = ret;
1868 goto fail_iput;
1869 }
1870
1871 features = btrfs_super_incompat_flags(disk_super) &
1872 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1873 if (features) {
1874 printk(KERN_ERR "BTRFS: couldn't mount because of "
1875 "unsupported optional features (%Lx).\n",
1876 (unsigned long long)features);
1877 err = -EINVAL;
1878 goto fail_iput;
1879 }
1880
1881 features = btrfs_super_incompat_flags(disk_super);
1882 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1883 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1884 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1885 btrfs_set_super_incompat_flags(disk_super, features);
1886
1887 features = btrfs_super_compat_ro_flags(disk_super) &
1888 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1889 if (!(sb->s_flags & MS_RDONLY) && features) {
1890 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1891 "unsupported option features (%Lx).\n",
1892 (unsigned long long)features);
1893 err = -EINVAL;
1894 goto fail_iput;
1895 }
1896
1897 btrfs_init_workers(&fs_info->generic_worker,
1898 "genwork", 1, NULL);
1899
1900 btrfs_init_workers(&fs_info->workers, "worker",
1901 fs_info->thread_pool_size,
1902 &fs_info->generic_worker);
1903
1904 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1905 fs_info->thread_pool_size,
1906 &fs_info->generic_worker);
1907
1908 btrfs_init_workers(&fs_info->submit_workers, "submit",
1909 min_t(u64, fs_devices->num_devices,
1910 fs_info->thread_pool_size),
1911 &fs_info->generic_worker);
1912
1913 /* a higher idle thresh on the submit workers makes it much more
1914 * likely that bios will be send down in a sane order to the
1915 * devices
1916 */
1917 fs_info->submit_workers.idle_thresh = 64;
1918
1919 fs_info->workers.idle_thresh = 16;
1920 fs_info->workers.ordered = 1;
1921
1922 fs_info->delalloc_workers.idle_thresh = 2;
1923 fs_info->delalloc_workers.ordered = 1;
1924
1925 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1926 &fs_info->generic_worker);
1927 btrfs_init_workers(&fs_info->endio_workers, "endio",
1928 fs_info->thread_pool_size,
1929 &fs_info->generic_worker);
1930 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1931 fs_info->thread_pool_size,
1932 &fs_info->generic_worker);
1933 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1934 "endio-meta-write", fs_info->thread_pool_size,
1935 &fs_info->generic_worker);
1936 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1937 fs_info->thread_pool_size,
1938 &fs_info->generic_worker);
1939 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1940 1, &fs_info->generic_worker);
1941
1942 /*
1943 * endios are largely parallel and should have a very
1944 * low idle thresh
1945 */
1946 fs_info->endio_workers.idle_thresh = 4;
1947 fs_info->endio_meta_workers.idle_thresh = 4;
1948
1949 fs_info->endio_write_workers.idle_thresh = 2;
1950 fs_info->endio_meta_write_workers.idle_thresh = 2;
1951
1952 btrfs_start_workers(&fs_info->workers, 1);
1953 btrfs_start_workers(&fs_info->generic_worker, 1);
1954 btrfs_start_workers(&fs_info->submit_workers, 1);
1955 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1956 btrfs_start_workers(&fs_info->fixup_workers, 1);
1957 btrfs_start_workers(&fs_info->endio_workers, 1);
1958 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1959 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1960 btrfs_start_workers(&fs_info->endio_write_workers, 1);
1961 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1962
1963 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1964 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1965 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1966
1967 nodesize = btrfs_super_nodesize(disk_super);
1968 leafsize = btrfs_super_leafsize(disk_super);
1969 sectorsize = btrfs_super_sectorsize(disk_super);
1970 stripesize = btrfs_super_stripesize(disk_super);
1971 tree_root->nodesize = nodesize;
1972 tree_root->leafsize = leafsize;
1973 tree_root->sectorsize = sectorsize;
1974 tree_root->stripesize = stripesize;
1975
1976 sb->s_blocksize = sectorsize;
1977 sb->s_blocksize_bits = blksize_bits(sectorsize);
1978
1979 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1980 sizeof(disk_super->magic))) {
1981 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1982 goto fail_sb_buffer;
1983 }
1984
1985 mutex_lock(&fs_info->chunk_mutex);
1986 ret = btrfs_read_sys_array(tree_root);
1987 mutex_unlock(&fs_info->chunk_mutex);
1988 if (ret) {
1989 printk(KERN_WARNING "btrfs: failed to read the system "
1990 "array on %s\n", sb->s_id);
1991 goto fail_sb_buffer;
1992 }
1993
1994 blocksize = btrfs_level_size(tree_root,
1995 btrfs_super_chunk_root_level(disk_super));
1996 generation = btrfs_super_chunk_root_generation(disk_super);
1997
1998 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1999 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2000
2001 chunk_root->node = read_tree_block(chunk_root,
2002 btrfs_super_chunk_root(disk_super),
2003 blocksize, generation);
2004 BUG_ON(!chunk_root->node);
2005 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2006 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2007 sb->s_id);
2008 goto fail_chunk_root;
2009 }
2010 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2011 chunk_root->commit_root = btrfs_root_node(chunk_root);
2012
2013 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2014 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2015 BTRFS_UUID_SIZE);
2016
2017 mutex_lock(&fs_info->chunk_mutex);
2018 ret = btrfs_read_chunk_tree(chunk_root);
2019 mutex_unlock(&fs_info->chunk_mutex);
2020 if (ret) {
2021 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2022 sb->s_id);
2023 goto fail_chunk_root;
2024 }
2025
2026 btrfs_close_extra_devices(fs_devices);
2027
2028 blocksize = btrfs_level_size(tree_root,
2029 btrfs_super_root_level(disk_super));
2030 generation = btrfs_super_generation(disk_super);
2031
2032 tree_root->node = read_tree_block(tree_root,
2033 btrfs_super_root(disk_super),
2034 blocksize, generation);
2035 if (!tree_root->node)
2036 goto fail_chunk_root;
2037 if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2038 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2039 sb->s_id);
2040 goto fail_tree_root;
2041 }
2042 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2043 tree_root->commit_root = btrfs_root_node(tree_root);
2044
2045 ret = find_and_setup_root(tree_root, fs_info,
2046 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2047 if (ret)
2048 goto fail_tree_root;
2049 extent_root->track_dirty = 1;
2050
2051 ret = find_and_setup_root(tree_root, fs_info,
2052 BTRFS_DEV_TREE_OBJECTID, dev_root);
2053 if (ret)
2054 goto fail_extent_root;
2055 dev_root->track_dirty = 1;
2056
2057 ret = find_and_setup_root(tree_root, fs_info,
2058 BTRFS_CSUM_TREE_OBJECTID, csum_root);
2059 if (ret)
2060 goto fail_dev_root;
2061
2062 csum_root->track_dirty = 1;
2063
2064 fs_info->generation = generation;
2065 fs_info->last_trans_committed = generation;
2066 fs_info->data_alloc_profile = (u64)-1;
2067 fs_info->metadata_alloc_profile = (u64)-1;
2068 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
2069
2070 ret = btrfs_init_space_info(fs_info);
2071 if (ret) {
2072 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2073 goto fail_block_groups;
2074 }
2075
2076 ret = btrfs_read_block_groups(extent_root);
2077 if (ret) {
2078 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2079 goto fail_block_groups;
2080 }
2081
2082 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2083 "btrfs-cleaner");
2084 if (IS_ERR(fs_info->cleaner_kthread))
2085 goto fail_block_groups;
2086
2087 fs_info->transaction_kthread = kthread_run(transaction_kthread,
2088 tree_root,
2089 "btrfs-transaction");
2090 if (IS_ERR(fs_info->transaction_kthread))
2091 goto fail_cleaner;
2092
2093 if (!btrfs_test_opt(tree_root, SSD) &&
2094 !btrfs_test_opt(tree_root, NOSSD) &&
2095 !fs_info->fs_devices->rotating) {
2096 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2097 "mode\n");
2098 btrfs_set_opt(fs_info->mount_opt, SSD);
2099 }
2100
2101 /* do not make disk changes in broken FS */
2102 if (btrfs_super_log_root(disk_super) != 0 &&
2103 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2104 u64 bytenr = btrfs_super_log_root(disk_super);
2105
2106 if (fs_devices->rw_devices == 0) {
2107 printk(KERN_WARNING "Btrfs log replay required "
2108 "on RO media\n");
2109 err = -EIO;
2110 goto fail_trans_kthread;
2111 }
2112 blocksize =
2113 btrfs_level_size(tree_root,
2114 btrfs_super_log_root_level(disk_super));
2115
2116 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2117 if (!log_tree_root) {
2118 err = -ENOMEM;
2119 goto fail_trans_kthread;
2120 }
2121
2122 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2123 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2124
2125 log_tree_root->node = read_tree_block(tree_root, bytenr,
2126 blocksize,
2127 generation + 1);
2128 ret = btrfs_recover_log_trees(log_tree_root);
2129 BUG_ON(ret);
2130
2131 if (sb->s_flags & MS_RDONLY) {
2132 ret = btrfs_commit_super(tree_root);
2133 BUG_ON(ret);
2134 }
2135 }
2136
2137 ret = btrfs_find_orphan_roots(tree_root);
2138 BUG_ON(ret);
2139
2140 if (!(sb->s_flags & MS_RDONLY)) {
2141 ret = btrfs_cleanup_fs_roots(fs_info);
2142 BUG_ON(ret);
2143
2144 ret = btrfs_recover_relocation(tree_root);
2145 if (ret < 0) {
2146 printk(KERN_WARNING
2147 "btrfs: failed to recover relocation\n");
2148 err = -EINVAL;
2149 goto fail_trans_kthread;
2150 }
2151 }
2152
2153 location.objectid = BTRFS_FS_TREE_OBJECTID;
2154 location.type = BTRFS_ROOT_ITEM_KEY;
2155 location.offset = (u64)-1;
2156
2157 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2158 if (!fs_info->fs_root)
2159 goto fail_trans_kthread;
2160 if (IS_ERR(fs_info->fs_root)) {
2161 err = PTR_ERR(fs_info->fs_root);
2162 goto fail_trans_kthread;
2163 }
2164
2165 if (!(sb->s_flags & MS_RDONLY)) {
2166 down_read(&fs_info->cleanup_work_sem);
2167 err = btrfs_orphan_cleanup(fs_info->fs_root);
2168 if (!err)
2169 err = btrfs_orphan_cleanup(fs_info->tree_root);
2170 up_read(&fs_info->cleanup_work_sem);
2171 if (err) {
2172 close_ctree(tree_root);
2173 return ERR_PTR(err);
2174 }
2175 }
2176
2177 return tree_root;
2178
2179 fail_trans_kthread:
2180 kthread_stop(fs_info->transaction_kthread);
2181 fail_cleaner:
2182 kthread_stop(fs_info->cleaner_kthread);
2183
2184 /*
2185 * make sure we're done with the btree inode before we stop our
2186 * kthreads
2187 */
2188 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2189 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2190
2191 fail_block_groups:
2192 btrfs_free_block_groups(fs_info);
2193 free_extent_buffer(csum_root->node);
2194 free_extent_buffer(csum_root->commit_root);
2195 fail_dev_root:
2196 free_extent_buffer(dev_root->node);
2197 free_extent_buffer(dev_root->commit_root);
2198 fail_extent_root:
2199 free_extent_buffer(extent_root->node);
2200 free_extent_buffer(extent_root->commit_root);
2201 fail_tree_root:
2202 free_extent_buffer(tree_root->node);
2203 free_extent_buffer(tree_root->commit_root);
2204 fail_chunk_root:
2205 free_extent_buffer(chunk_root->node);
2206 free_extent_buffer(chunk_root->commit_root);
2207 fail_sb_buffer:
2208 btrfs_stop_workers(&fs_info->generic_worker);
2209 btrfs_stop_workers(&fs_info->fixup_workers);
2210 btrfs_stop_workers(&fs_info->delalloc_workers);
2211 btrfs_stop_workers(&fs_info->workers);
2212 btrfs_stop_workers(&fs_info->endio_workers);
2213 btrfs_stop_workers(&fs_info->endio_meta_workers);
2214 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2215 btrfs_stop_workers(&fs_info->endio_write_workers);
2216 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2217 btrfs_stop_workers(&fs_info->submit_workers);
2218 fail_iput:
2219 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2220 iput(fs_info->btree_inode);
2221
2222 btrfs_close_devices(fs_info->fs_devices);
2223 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2224 fail_bdi:
2225 bdi_destroy(&fs_info->bdi);
2226 fail_srcu:
2227 cleanup_srcu_struct(&fs_info->subvol_srcu);
2228 fail:
2229 kfree(extent_root);
2230 kfree(tree_root);
2231 kfree(fs_info);
2232 kfree(chunk_root);
2233 kfree(dev_root);
2234 kfree(csum_root);
2235 return ERR_PTR(err);
2236 }
2237
2238 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2239 {
2240 char b[BDEVNAME_SIZE];
2241
2242 if (uptodate) {
2243 set_buffer_uptodate(bh);
2244 } else {
2245 if (printk_ratelimit()) {
2246 printk(KERN_WARNING "lost page write due to "
2247 "I/O error on %s\n",
2248 bdevname(bh->b_bdev, b));
2249 }
2250 /* note, we dont' set_buffer_write_io_error because we have
2251 * our own ways of dealing with the IO errors
2252 */
2253 clear_buffer_uptodate(bh);
2254 }
2255 unlock_buffer(bh);
2256 put_bh(bh);
2257 }
2258
2259 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2260 {
2261 struct buffer_head *bh;
2262 struct buffer_head *latest = NULL;
2263 struct btrfs_super_block *super;
2264 int i;
2265 u64 transid = 0;
2266 u64 bytenr;
2267
2268 /* we would like to check all the supers, but that would make
2269 * a btrfs mount succeed after a mkfs from a different FS.
2270 * So, we need to add a special mount option to scan for
2271 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2272 */
2273 for (i = 0; i < 1; i++) {
2274 bytenr = btrfs_sb_offset(i);
2275 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2276 break;
2277 bh = __bread(bdev, bytenr / 4096, 4096);
2278 if (!bh)
2279 continue;
2280
2281 super = (struct btrfs_super_block *)bh->b_data;
2282 if (btrfs_super_bytenr(super) != bytenr ||
2283 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2284 sizeof(super->magic))) {
2285 brelse(bh);
2286 continue;
2287 }
2288
2289 if (!latest || btrfs_super_generation(super) > transid) {
2290 brelse(latest);
2291 latest = bh;
2292 transid = btrfs_super_generation(super);
2293 } else {
2294 brelse(bh);
2295 }
2296 }
2297 return latest;
2298 }
2299
2300 /*
2301 * this should be called twice, once with wait == 0 and
2302 * once with wait == 1. When wait == 0 is done, all the buffer heads
2303 * we write are pinned.
2304 *
2305 * They are released when wait == 1 is done.
2306 * max_mirrors must be the same for both runs, and it indicates how
2307 * many supers on this one device should be written.
2308 *
2309 * max_mirrors == 0 means to write them all.
2310 */
2311 static int write_dev_supers(struct btrfs_device *device,
2312 struct btrfs_super_block *sb,
2313 int do_barriers, int wait, int max_mirrors)
2314 {
2315 struct buffer_head *bh;
2316 int i;
2317 int ret;
2318 int errors = 0;
2319 u32 crc;
2320 u64 bytenr;
2321 int last_barrier = 0;
2322
2323 if (max_mirrors == 0)
2324 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2325
2326 /* make sure only the last submit_bh does a barrier */
2327 if (do_barriers) {
2328 for (i = 0; i < max_mirrors; i++) {
2329 bytenr = btrfs_sb_offset(i);
2330 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2331 device->total_bytes)
2332 break;
2333 last_barrier = i;
2334 }
2335 }
2336
2337 for (i = 0; i < max_mirrors; i++) {
2338 bytenr = btrfs_sb_offset(i);
2339 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2340 break;
2341
2342 if (wait) {
2343 bh = __find_get_block(device->bdev, bytenr / 4096,
2344 BTRFS_SUPER_INFO_SIZE);
2345 BUG_ON(!bh);
2346 wait_on_buffer(bh);
2347 if (!buffer_uptodate(bh))
2348 errors++;
2349
2350 /* drop our reference */
2351 brelse(bh);
2352
2353 /* drop the reference from the wait == 0 run */
2354 brelse(bh);
2355 continue;
2356 } else {
2357 btrfs_set_super_bytenr(sb, bytenr);
2358
2359 crc = ~(u32)0;
2360 crc = btrfs_csum_data(NULL, (char *)sb +
2361 BTRFS_CSUM_SIZE, crc,
2362 BTRFS_SUPER_INFO_SIZE -
2363 BTRFS_CSUM_SIZE);
2364 btrfs_csum_final(crc, sb->csum);
2365
2366 /*
2367 * one reference for us, and we leave it for the
2368 * caller
2369 */
2370 bh = __getblk(device->bdev, bytenr / 4096,
2371 BTRFS_SUPER_INFO_SIZE);
2372 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2373
2374 /* one reference for submit_bh */
2375 get_bh(bh);
2376
2377 set_buffer_uptodate(bh);
2378 lock_buffer(bh);
2379 bh->b_end_io = btrfs_end_buffer_write_sync;
2380 }
2381
2382 if (i == last_barrier && do_barriers)
2383 ret = submit_bh(WRITE_FLUSH_FUA, bh);
2384 else
2385 ret = submit_bh(WRITE_SYNC, bh);
2386
2387 if (ret)
2388 errors++;
2389 }
2390 return errors < i ? 0 : -1;
2391 }
2392
2393 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2394 {
2395 struct list_head *head;
2396 struct btrfs_device *dev;
2397 struct btrfs_super_block *sb;
2398 struct btrfs_dev_item *dev_item;
2399 int ret;
2400 int do_barriers;
2401 int max_errors;
2402 int total_errors = 0;
2403 u64 flags;
2404
2405 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2406 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2407
2408 sb = &root->fs_info->super_for_commit;
2409 dev_item = &sb->dev_item;
2410
2411 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2412 head = &root->fs_info->fs_devices->devices;
2413 list_for_each_entry(dev, head, dev_list) {
2414 if (!dev->bdev) {
2415 total_errors++;
2416 continue;
2417 }
2418 if (!dev->in_fs_metadata || !dev->writeable)
2419 continue;
2420
2421 btrfs_set_stack_device_generation(dev_item, 0);
2422 btrfs_set_stack_device_type(dev_item, dev->type);
2423 btrfs_set_stack_device_id(dev_item, dev->devid);
2424 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2425 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2426 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2427 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2428 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2429 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2430 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2431
2432 flags = btrfs_super_flags(sb);
2433 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2434
2435 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2436 if (ret)
2437 total_errors++;
2438 }
2439 if (total_errors > max_errors) {
2440 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2441 total_errors);
2442 BUG();
2443 }
2444
2445 total_errors = 0;
2446 list_for_each_entry(dev, head, dev_list) {
2447 if (!dev->bdev)
2448 continue;
2449 if (!dev->in_fs_metadata || !dev->writeable)
2450 continue;
2451
2452 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2453 if (ret)
2454 total_errors++;
2455 }
2456 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2457 if (total_errors > max_errors) {
2458 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2459 total_errors);
2460 BUG();
2461 }
2462 return 0;
2463 }
2464
2465 int write_ctree_super(struct btrfs_trans_handle *trans,
2466 struct btrfs_root *root, int max_mirrors)
2467 {
2468 int ret;
2469
2470 ret = write_all_supers(root, max_mirrors);
2471 return ret;
2472 }
2473
2474 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2475 {
2476 spin_lock(&fs_info->fs_roots_radix_lock);
2477 radix_tree_delete(&fs_info->fs_roots_radix,
2478 (unsigned long)root->root_key.objectid);
2479 spin_unlock(&fs_info->fs_roots_radix_lock);
2480
2481 if (btrfs_root_refs(&root->root_item) == 0)
2482 synchronize_srcu(&fs_info->subvol_srcu);
2483
2484 free_fs_root(root);
2485 return 0;
2486 }
2487
2488 static void free_fs_root(struct btrfs_root *root)
2489 {
2490 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2491 if (root->anon_super.s_dev) {
2492 down_write(&root->anon_super.s_umount);
2493 kill_anon_super(&root->anon_super);
2494 }
2495 free_extent_buffer(root->node);
2496 free_extent_buffer(root->commit_root);
2497 kfree(root->name);
2498 kfree(root);
2499 }
2500
2501 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2502 {
2503 int ret;
2504 struct btrfs_root *gang[8];
2505 int i;
2506
2507 while (!list_empty(&fs_info->dead_roots)) {
2508 gang[0] = list_entry(fs_info->dead_roots.next,
2509 struct btrfs_root, root_list);
2510 list_del(&gang[0]->root_list);
2511
2512 if (gang[0]->in_radix) {
2513 btrfs_free_fs_root(fs_info, gang[0]);
2514 } else {
2515 free_extent_buffer(gang[0]->node);
2516 free_extent_buffer(gang[0]->commit_root);
2517 kfree(gang[0]);
2518 }
2519 }
2520
2521 while (1) {
2522 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2523 (void **)gang, 0,
2524 ARRAY_SIZE(gang));
2525 if (!ret)
2526 break;
2527 for (i = 0; i < ret; i++)
2528 btrfs_free_fs_root(fs_info, gang[i]);
2529 }
2530 return 0;
2531 }
2532
2533 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2534 {
2535 u64 root_objectid = 0;
2536 struct btrfs_root *gang[8];
2537 int i;
2538 int ret;
2539
2540 while (1) {
2541 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2542 (void **)gang, root_objectid,
2543 ARRAY_SIZE(gang));
2544 if (!ret)
2545 break;
2546
2547 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2548 for (i = 0; i < ret; i++) {
2549 int err;
2550
2551 root_objectid = gang[i]->root_key.objectid;
2552 err = btrfs_orphan_cleanup(gang[i]);
2553 if (err)
2554 return err;
2555 }
2556 root_objectid++;
2557 }
2558 return 0;
2559 }
2560
2561 int btrfs_commit_super(struct btrfs_root *root)
2562 {
2563 struct btrfs_trans_handle *trans;
2564 int ret;
2565
2566 mutex_lock(&root->fs_info->cleaner_mutex);
2567 btrfs_run_delayed_iputs(root);
2568 btrfs_clean_old_snapshots(root);
2569 mutex_unlock(&root->fs_info->cleaner_mutex);
2570
2571 /* wait until ongoing cleanup work done */
2572 down_write(&root->fs_info->cleanup_work_sem);
2573 up_write(&root->fs_info->cleanup_work_sem);
2574
2575 trans = btrfs_join_transaction(root, 1);
2576 if (IS_ERR(trans))
2577 return PTR_ERR(trans);
2578 ret = btrfs_commit_transaction(trans, root);
2579 BUG_ON(ret);
2580 /* run commit again to drop the original snapshot */
2581 trans = btrfs_join_transaction(root, 1);
2582 if (IS_ERR(trans))
2583 return PTR_ERR(trans);
2584 btrfs_commit_transaction(trans, root);
2585 ret = btrfs_write_and_wait_transaction(NULL, root);
2586 BUG_ON(ret);
2587
2588 ret = write_ctree_super(NULL, root, 0);
2589 return ret;
2590 }
2591
2592 int close_ctree(struct btrfs_root *root)
2593 {
2594 struct btrfs_fs_info *fs_info = root->fs_info;
2595 int ret;
2596
2597 fs_info->closing = 1;
2598 smp_mb();
2599
2600 btrfs_put_block_group_cache(fs_info);
2601
2602 /*
2603 * Here come 2 situations when btrfs is broken to flip readonly:
2604 *
2605 * 1. when btrfs flips readonly somewhere else before
2606 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2607 * and btrfs will skip to write sb directly to keep
2608 * ERROR state on disk.
2609 *
2610 * 2. when btrfs flips readonly just in btrfs_commit_super,
2611 * and in such case, btrfs cannnot write sb via btrfs_commit_super,
2612 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2613 * btrfs will cleanup all FS resources first and write sb then.
2614 */
2615 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2616 ret = btrfs_commit_super(root);
2617 if (ret)
2618 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2619 }
2620
2621 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2622 ret = btrfs_error_commit_super(root);
2623 if (ret)
2624 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2625 }
2626
2627 kthread_stop(root->fs_info->transaction_kthread);
2628 kthread_stop(root->fs_info->cleaner_kthread);
2629
2630 fs_info->closing = 2;
2631 smp_mb();
2632
2633 if (fs_info->delalloc_bytes) {
2634 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2635 (unsigned long long)fs_info->delalloc_bytes);
2636 }
2637 if (fs_info->total_ref_cache_size) {
2638 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2639 (unsigned long long)fs_info->total_ref_cache_size);
2640 }
2641
2642 free_extent_buffer(fs_info->extent_root->node);
2643 free_extent_buffer(fs_info->extent_root->commit_root);
2644 free_extent_buffer(fs_info->tree_root->node);
2645 free_extent_buffer(fs_info->tree_root->commit_root);
2646 free_extent_buffer(root->fs_info->chunk_root->node);
2647 free_extent_buffer(root->fs_info->chunk_root->commit_root);
2648 free_extent_buffer(root->fs_info->dev_root->node);
2649 free_extent_buffer(root->fs_info->dev_root->commit_root);
2650 free_extent_buffer(root->fs_info->csum_root->node);
2651 free_extent_buffer(root->fs_info->csum_root->commit_root);
2652
2653 btrfs_free_block_groups(root->fs_info);
2654
2655 del_fs_roots(fs_info);
2656
2657 iput(fs_info->btree_inode);
2658
2659 btrfs_stop_workers(&fs_info->generic_worker);
2660 btrfs_stop_workers(&fs_info->fixup_workers);
2661 btrfs_stop_workers(&fs_info->delalloc_workers);
2662 btrfs_stop_workers(&fs_info->workers);
2663 btrfs_stop_workers(&fs_info->endio_workers);
2664 btrfs_stop_workers(&fs_info->endio_meta_workers);
2665 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2666 btrfs_stop_workers(&fs_info->endio_write_workers);
2667 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2668 btrfs_stop_workers(&fs_info->submit_workers);
2669
2670 btrfs_close_devices(fs_info->fs_devices);
2671 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2672
2673 bdi_destroy(&fs_info->bdi);
2674 cleanup_srcu_struct(&fs_info->subvol_srcu);
2675
2676 kfree(fs_info->extent_root);
2677 kfree(fs_info->tree_root);
2678 kfree(fs_info->chunk_root);
2679 kfree(fs_info->dev_root);
2680 kfree(fs_info->csum_root);
2681 kfree(fs_info);
2682
2683 return 0;
2684 }
2685
2686 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2687 {
2688 int ret;
2689 struct inode *btree_inode = buf->first_page->mapping->host;
2690
2691 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2692 NULL);
2693 if (!ret)
2694 return ret;
2695
2696 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2697 parent_transid);
2698 return !ret;
2699 }
2700
2701 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2702 {
2703 struct inode *btree_inode = buf->first_page->mapping->host;
2704 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2705 buf);
2706 }
2707
2708 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2709 {
2710 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2711 u64 transid = btrfs_header_generation(buf);
2712 struct inode *btree_inode = root->fs_info->btree_inode;
2713 int was_dirty;
2714
2715 btrfs_assert_tree_locked(buf);
2716 if (transid != root->fs_info->generation) {
2717 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2718 "found %llu running %llu\n",
2719 (unsigned long long)buf->start,
2720 (unsigned long long)transid,
2721 (unsigned long long)root->fs_info->generation);
2722 WARN_ON(1);
2723 }
2724 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2725 buf);
2726 if (!was_dirty) {
2727 spin_lock(&root->fs_info->delalloc_lock);
2728 root->fs_info->dirty_metadata_bytes += buf->len;
2729 spin_unlock(&root->fs_info->delalloc_lock);
2730 }
2731 }
2732
2733 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2734 {
2735 /*
2736 * looks as though older kernels can get into trouble with
2737 * this code, they end up stuck in balance_dirty_pages forever
2738 */
2739 u64 num_dirty;
2740 unsigned long thresh = 32 * 1024 * 1024;
2741
2742 if (current->flags & PF_MEMALLOC)
2743 return;
2744
2745 num_dirty = root->fs_info->dirty_metadata_bytes;
2746
2747 if (num_dirty > thresh) {
2748 balance_dirty_pages_ratelimited_nr(
2749 root->fs_info->btree_inode->i_mapping, 1);
2750 }
2751 return;
2752 }
2753
2754 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2755 {
2756 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2757 int ret;
2758 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2759 if (ret == 0)
2760 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2761 return ret;
2762 }
2763
2764 int btree_lock_page_hook(struct page *page)
2765 {
2766 struct inode *inode = page->mapping->host;
2767 struct btrfs_root *root = BTRFS_I(inode)->root;
2768 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2769 struct extent_buffer *eb;
2770 unsigned long len;
2771 u64 bytenr = page_offset(page);
2772
2773 if (page->private == EXTENT_PAGE_PRIVATE)
2774 goto out;
2775
2776 len = page->private >> 2;
2777 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2778 if (!eb)
2779 goto out;
2780
2781 btrfs_tree_lock(eb);
2782 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2783
2784 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2785 spin_lock(&root->fs_info->delalloc_lock);
2786 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2787 root->fs_info->dirty_metadata_bytes -= eb->len;
2788 else
2789 WARN_ON(1);
2790 spin_unlock(&root->fs_info->delalloc_lock);
2791 }
2792
2793 btrfs_tree_unlock(eb);
2794 free_extent_buffer(eb);
2795 out:
2796 lock_page(page);
2797 return 0;
2798 }
2799
2800 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2801 int read_only)
2802 {
2803 if (read_only)
2804 return;
2805
2806 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2807 printk(KERN_WARNING "warning: mount fs with errors, "
2808 "running btrfsck is recommended\n");
2809 }
2810
2811 int btrfs_error_commit_super(struct btrfs_root *root)
2812 {
2813 int ret;
2814
2815 mutex_lock(&root->fs_info->cleaner_mutex);
2816 btrfs_run_delayed_iputs(root);
2817 mutex_unlock(&root->fs_info->cleaner_mutex);
2818
2819 down_write(&root->fs_info->cleanup_work_sem);
2820 up_write(&root->fs_info->cleanup_work_sem);
2821
2822 /* cleanup FS via transaction */
2823 btrfs_cleanup_transaction(root);
2824
2825 ret = write_ctree_super(NULL, root, 0);
2826
2827 return ret;
2828 }
2829
2830 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2831 {
2832 struct btrfs_inode *btrfs_inode;
2833 struct list_head splice;
2834
2835 INIT_LIST_HEAD(&splice);
2836
2837 mutex_lock(&root->fs_info->ordered_operations_mutex);
2838 spin_lock(&root->fs_info->ordered_extent_lock);
2839
2840 list_splice_init(&root->fs_info->ordered_operations, &splice);
2841 while (!list_empty(&splice)) {
2842 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2843 ordered_operations);
2844
2845 list_del_init(&btrfs_inode->ordered_operations);
2846
2847 btrfs_invalidate_inodes(btrfs_inode->root);
2848 }
2849
2850 spin_unlock(&root->fs_info->ordered_extent_lock);
2851 mutex_unlock(&root->fs_info->ordered_operations_mutex);
2852
2853 return 0;
2854 }
2855
2856 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2857 {
2858 struct list_head splice;
2859 struct btrfs_ordered_extent *ordered;
2860 struct inode *inode;
2861
2862 INIT_LIST_HEAD(&splice);
2863
2864 spin_lock(&root->fs_info->ordered_extent_lock);
2865
2866 list_splice_init(&root->fs_info->ordered_extents, &splice);
2867 while (!list_empty(&splice)) {
2868 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2869 root_extent_list);
2870
2871 list_del_init(&ordered->root_extent_list);
2872 atomic_inc(&ordered->refs);
2873
2874 /* the inode may be getting freed (in sys_unlink path). */
2875 inode = igrab(ordered->inode);
2876
2877 spin_unlock(&root->fs_info->ordered_extent_lock);
2878 if (inode)
2879 iput(inode);
2880
2881 atomic_set(&ordered->refs, 1);
2882 btrfs_put_ordered_extent(ordered);
2883
2884 spin_lock(&root->fs_info->ordered_extent_lock);
2885 }
2886
2887 spin_unlock(&root->fs_info->ordered_extent_lock);
2888
2889 return 0;
2890 }
2891
2892 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2893 struct btrfs_root *root)
2894 {
2895 struct rb_node *node;
2896 struct btrfs_delayed_ref_root *delayed_refs;
2897 struct btrfs_delayed_ref_node *ref;
2898 int ret = 0;
2899
2900 delayed_refs = &trans->delayed_refs;
2901
2902 spin_lock(&delayed_refs->lock);
2903 if (delayed_refs->num_entries == 0) {
2904 printk(KERN_INFO "delayed_refs has NO entry\n");
2905 return ret;
2906 }
2907
2908 node = rb_first(&delayed_refs->root);
2909 while (node) {
2910 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2911 node = rb_next(node);
2912
2913 ref->in_tree = 0;
2914 rb_erase(&ref->rb_node, &delayed_refs->root);
2915 delayed_refs->num_entries--;
2916
2917 atomic_set(&ref->refs, 1);
2918 if (btrfs_delayed_ref_is_head(ref)) {
2919 struct btrfs_delayed_ref_head *head;
2920
2921 head = btrfs_delayed_node_to_head(ref);
2922 mutex_lock(&head->mutex);
2923 kfree(head->extent_op);
2924 delayed_refs->num_heads--;
2925 if (list_empty(&head->cluster))
2926 delayed_refs->num_heads_ready--;
2927 list_del_init(&head->cluster);
2928 mutex_unlock(&head->mutex);
2929 }
2930
2931 spin_unlock(&delayed_refs->lock);
2932 btrfs_put_delayed_ref(ref);
2933
2934 cond_resched();
2935 spin_lock(&delayed_refs->lock);
2936 }
2937
2938 spin_unlock(&delayed_refs->lock);
2939
2940 return ret;
2941 }
2942
2943 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2944 {
2945 struct btrfs_pending_snapshot *snapshot;
2946 struct list_head splice;
2947
2948 INIT_LIST_HEAD(&splice);
2949
2950 list_splice_init(&t->pending_snapshots, &splice);
2951
2952 while (!list_empty(&splice)) {
2953 snapshot = list_entry(splice.next,
2954 struct btrfs_pending_snapshot,
2955 list);
2956
2957 list_del_init(&snapshot->list);
2958
2959 kfree(snapshot);
2960 }
2961
2962 return 0;
2963 }
2964
2965 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2966 {
2967 struct btrfs_inode *btrfs_inode;
2968 struct list_head splice;
2969
2970 INIT_LIST_HEAD(&splice);
2971
2972 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2973
2974 spin_lock(&root->fs_info->delalloc_lock);
2975
2976 while (!list_empty(&splice)) {
2977 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2978 delalloc_inodes);
2979
2980 list_del_init(&btrfs_inode->delalloc_inodes);
2981
2982 btrfs_invalidate_inodes(btrfs_inode->root);
2983 }
2984
2985 spin_unlock(&root->fs_info->delalloc_lock);
2986
2987 return 0;
2988 }
2989
2990 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2991 struct extent_io_tree *dirty_pages,
2992 int mark)
2993 {
2994 int ret;
2995 struct page *page;
2996 struct inode *btree_inode = root->fs_info->btree_inode;
2997 struct extent_buffer *eb;
2998 u64 start = 0;
2999 u64 end;
3000 u64 offset;
3001 unsigned long index;
3002
3003 while (1) {
3004 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3005 mark);
3006 if (ret)
3007 break;
3008
3009 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3010 while (start <= end) {
3011 index = start >> PAGE_CACHE_SHIFT;
3012 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3013 page = find_get_page(btree_inode->i_mapping, index);
3014 if (!page)
3015 continue;
3016 offset = page_offset(page);
3017
3018 spin_lock(&dirty_pages->buffer_lock);
3019 eb = radix_tree_lookup(
3020 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3021 offset >> PAGE_CACHE_SHIFT);
3022 spin_unlock(&dirty_pages->buffer_lock);
3023 if (eb) {
3024 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3025 &eb->bflags);
3026 atomic_set(&eb->refs, 1);
3027 }
3028 if (PageWriteback(page))
3029 end_page_writeback(page);
3030
3031 lock_page(page);
3032 if (PageDirty(page)) {
3033 clear_page_dirty_for_io(page);
3034 spin_lock_irq(&page->mapping->tree_lock);
3035 radix_tree_tag_clear(&page->mapping->page_tree,
3036 page_index(page),
3037 PAGECACHE_TAG_DIRTY);
3038 spin_unlock_irq(&page->mapping->tree_lock);
3039 }
3040
3041 page->mapping->a_ops->invalidatepage(page, 0);
3042 unlock_page(page);
3043 }
3044 }
3045
3046 return ret;
3047 }
3048
3049 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3050 struct extent_io_tree *pinned_extents)
3051 {
3052 struct extent_io_tree *unpin;
3053 u64 start;
3054 u64 end;
3055 int ret;
3056
3057 unpin = pinned_extents;
3058 while (1) {
3059 ret = find_first_extent_bit(unpin, 0, &start, &end,
3060 EXTENT_DIRTY);
3061 if (ret)
3062 break;
3063
3064 /* opt_discard */
3065 if (btrfs_test_opt(root, DISCARD))
3066 ret = btrfs_error_discard_extent(root, start,
3067 end + 1 - start,
3068 NULL);
3069
3070 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3071 btrfs_error_unpin_extent_range(root, start, end);
3072 cond_resched();
3073 }
3074
3075 return 0;
3076 }
3077
3078 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3079 {
3080 struct btrfs_transaction *t;
3081 LIST_HEAD(list);
3082
3083 WARN_ON(1);
3084
3085 mutex_lock(&root->fs_info->trans_mutex);
3086 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3087
3088 list_splice_init(&root->fs_info->trans_list, &list);
3089 while (!list_empty(&list)) {
3090 t = list_entry(list.next, struct btrfs_transaction, list);
3091 if (!t)
3092 break;
3093
3094 btrfs_destroy_ordered_operations(root);
3095
3096 btrfs_destroy_ordered_extents(root);
3097
3098 btrfs_destroy_delayed_refs(t, root);
3099
3100 btrfs_block_rsv_release(root,
3101 &root->fs_info->trans_block_rsv,
3102 t->dirty_pages.dirty_bytes);
3103
3104 /* FIXME: cleanup wait for commit */
3105 t->in_commit = 1;
3106 t->blocked = 1;
3107 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3108 wake_up(&root->fs_info->transaction_blocked_wait);
3109
3110 t->blocked = 0;
3111 if (waitqueue_active(&root->fs_info->transaction_wait))
3112 wake_up(&root->fs_info->transaction_wait);
3113 mutex_unlock(&root->fs_info->trans_mutex);
3114
3115 mutex_lock(&root->fs_info->trans_mutex);
3116 t->commit_done = 1;
3117 if (waitqueue_active(&t->commit_wait))
3118 wake_up(&t->commit_wait);
3119 mutex_unlock(&root->fs_info->trans_mutex);
3120
3121 mutex_lock(&root->fs_info->trans_mutex);
3122
3123 btrfs_destroy_pending_snapshots(t);
3124
3125 btrfs_destroy_delalloc_inodes(root);
3126
3127 spin_lock(&root->fs_info->new_trans_lock);
3128 root->fs_info->running_transaction = NULL;
3129 spin_unlock(&root->fs_info->new_trans_lock);
3130
3131 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3132 EXTENT_DIRTY);
3133
3134 btrfs_destroy_pinned_extent(root,
3135 root->fs_info->pinned_extents);
3136
3137 t->use_count = 0;
3138 list_del_init(&t->list);
3139 memset(t, 0, sizeof(*t));
3140 kmem_cache_free(btrfs_transaction_cachep, t);
3141 }
3142
3143 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3144 mutex_unlock(&root->fs_info->trans_mutex);
3145
3146 return 0;
3147 }
3148
3149 static struct extent_io_ops btree_extent_io_ops = {
3150 .write_cache_pages_lock_hook = btree_lock_page_hook,
3151 .readpage_end_io_hook = btree_readpage_end_io_hook,
3152 .submit_bio_hook = btree_submit_bio_hook,
3153 /* note we're sharing with inode.c for the merge bio hook */
3154 .merge_bio_hook = btrfs_merge_bio_hook,
3155 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree