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Btrfs: implement memory reclaim for leaf reference cache
[deliverable/linux.git] / fs / btrfs / disk-io.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/version.h>
20 #include <linux/fs.h>
21 #include <linux/blkdev.h>
22 #include <linux/scatterlist.h>
23 #include <linux/swap.h>
24 #include <linux/radix-tree.h>
25 #include <linux/writeback.h>
26 #include <linux/buffer_head.h> // for block_sync_page
27 #include <linux/workqueue.h>
28 #include <linux/kthread.h>
29 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
30 # include <linux/freezer.h>
31 #else
32 # include <linux/sched.h>
33 #endif
34 #include "crc32c.h"
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "async-thread.h"
42 #include "locking.h"
43 #include "ref-cache.h"
44
45 #if 0
46 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
47 {
48 if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
49 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
50 (unsigned long long)extent_buffer_blocknr(buf),
51 (unsigned long long)btrfs_header_blocknr(buf));
52 return 1;
53 }
54 return 0;
55 }
56 #endif
57
58 static struct extent_io_ops btree_extent_io_ops;
59 static void end_workqueue_fn(struct btrfs_work *work);
60
61 struct end_io_wq {
62 struct bio *bio;
63 bio_end_io_t *end_io;
64 void *private;
65 struct btrfs_fs_info *info;
66 int error;
67 int metadata;
68 struct list_head list;
69 struct btrfs_work work;
70 };
71
72 struct async_submit_bio {
73 struct inode *inode;
74 struct bio *bio;
75 struct list_head list;
76 extent_submit_bio_hook_t *submit_bio_hook;
77 int rw;
78 int mirror_num;
79 struct btrfs_work work;
80 };
81
82 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
83 size_t page_offset, u64 start, u64 len,
84 int create)
85 {
86 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
87 struct extent_map *em;
88 int ret;
89
90 spin_lock(&em_tree->lock);
91 em = lookup_extent_mapping(em_tree, start, len);
92 if (em) {
93 em->bdev =
94 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
95 spin_unlock(&em_tree->lock);
96 goto out;
97 }
98 spin_unlock(&em_tree->lock);
99
100 em = alloc_extent_map(GFP_NOFS);
101 if (!em) {
102 em = ERR_PTR(-ENOMEM);
103 goto out;
104 }
105 em->start = 0;
106 em->len = (u64)-1;
107 em->block_start = 0;
108 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
109
110 spin_lock(&em_tree->lock);
111 ret = add_extent_mapping(em_tree, em);
112 if (ret == -EEXIST) {
113 u64 failed_start = em->start;
114 u64 failed_len = em->len;
115
116 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
117 em->start, em->len, em->block_start);
118 free_extent_map(em);
119 em = lookup_extent_mapping(em_tree, start, len);
120 if (em) {
121 printk("after failing, found %Lu %Lu %Lu\n",
122 em->start, em->len, em->block_start);
123 ret = 0;
124 } else {
125 em = lookup_extent_mapping(em_tree, failed_start,
126 failed_len);
127 if (em) {
128 printk("double failure lookup gives us "
129 "%Lu %Lu -> %Lu\n", em->start,
130 em->len, em->block_start);
131 free_extent_map(em);
132 }
133 ret = -EIO;
134 }
135 } else if (ret) {
136 free_extent_map(em);
137 em = NULL;
138 }
139 spin_unlock(&em_tree->lock);
140
141 if (ret)
142 em = ERR_PTR(ret);
143 out:
144 return em;
145 }
146
147 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
148 {
149 return btrfs_crc32c(seed, data, len);
150 }
151
152 void btrfs_csum_final(u32 crc, char *result)
153 {
154 *(__le32 *)result = ~cpu_to_le32(crc);
155 }
156
157 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
158 int verify)
159 {
160 char result[BTRFS_CRC32_SIZE];
161 unsigned long len;
162 unsigned long cur_len;
163 unsigned long offset = BTRFS_CSUM_SIZE;
164 char *map_token = NULL;
165 char *kaddr;
166 unsigned long map_start;
167 unsigned long map_len;
168 int err;
169 u32 crc = ~(u32)0;
170
171 len = buf->len - offset;
172 while(len > 0) {
173 err = map_private_extent_buffer(buf, offset, 32,
174 &map_token, &kaddr,
175 &map_start, &map_len, KM_USER0);
176 if (err) {
177 printk("failed to map extent buffer! %lu\n",
178 offset);
179 return 1;
180 }
181 cur_len = min(len, map_len - (offset - map_start));
182 crc = btrfs_csum_data(root, kaddr + offset - map_start,
183 crc, cur_len);
184 len -= cur_len;
185 offset += cur_len;
186 unmap_extent_buffer(buf, map_token, KM_USER0);
187 }
188 btrfs_csum_final(crc, result);
189
190 if (verify) {
191 int from_this_trans = 0;
192
193 if (root->fs_info->running_transaction &&
194 btrfs_header_generation(buf) ==
195 root->fs_info->running_transaction->transid)
196 from_this_trans = 1;
197
198 /* FIXME, this is not good */
199 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
200 u32 val;
201 u32 found = 0;
202 memcpy(&found, result, BTRFS_CRC32_SIZE);
203
204 read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
205 printk("btrfs: %s checksum verify failed on %llu "
206 "wanted %X found %X from_this_trans %d "
207 "level %d\n",
208 root->fs_info->sb->s_id,
209 buf->start, val, found, from_this_trans,
210 btrfs_header_level(buf));
211 return 1;
212 }
213 } else {
214 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
215 }
216 return 0;
217 }
218
219 static int verify_parent_transid(struct extent_io_tree *io_tree,
220 struct extent_buffer *eb, u64 parent_transid)
221 {
222 int ret;
223
224 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
225 return 0;
226
227 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
228 if (extent_buffer_uptodate(io_tree, eb) &&
229 btrfs_header_generation(eb) == parent_transid) {
230 ret = 0;
231 goto out;
232 }
233 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
234 (unsigned long long)eb->start,
235 (unsigned long long)parent_transid,
236 (unsigned long long)btrfs_header_generation(eb));
237 ret = 1;
238 clear_extent_buffer_uptodate(io_tree, eb);
239 out:
240 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
241 GFP_NOFS);
242 return ret;
243
244 }
245
246 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
247 struct extent_buffer *eb,
248 u64 start, u64 parent_transid)
249 {
250 struct extent_io_tree *io_tree;
251 int ret;
252 int num_copies = 0;
253 int mirror_num = 0;
254
255 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
256 while (1) {
257 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
258 btree_get_extent, mirror_num);
259 if (!ret &&
260 !verify_parent_transid(io_tree, eb, parent_transid))
261 return ret;
262
263 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
264 eb->start, eb->len);
265 if (num_copies == 1)
266 return ret;
267
268 mirror_num++;
269 if (mirror_num > num_copies)
270 return ret;
271 }
272 return -EIO;
273 }
274
275 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
276 {
277 struct extent_io_tree *tree;
278 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
279 u64 found_start;
280 int found_level;
281 unsigned long len;
282 struct extent_buffer *eb;
283 int ret;
284
285 tree = &BTRFS_I(page->mapping->host)->io_tree;
286
287 if (page->private == EXTENT_PAGE_PRIVATE)
288 goto out;
289 if (!page->private)
290 goto out;
291 len = page->private >> 2;
292 if (len == 0) {
293 WARN_ON(1);
294 }
295 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
296 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
297 btrfs_header_generation(eb));
298 BUG_ON(ret);
299 found_start = btrfs_header_bytenr(eb);
300 if (found_start != start) {
301 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
302 start, found_start, len);
303 WARN_ON(1);
304 goto err;
305 }
306 if (eb->first_page != page) {
307 printk("bad first page %lu %lu\n", eb->first_page->index,
308 page->index);
309 WARN_ON(1);
310 goto err;
311 }
312 if (!PageUptodate(page)) {
313 printk("csum not up to date page %lu\n", page->index);
314 WARN_ON(1);
315 goto err;
316 }
317 found_level = btrfs_header_level(eb);
318 spin_lock(&root->fs_info->hash_lock);
319 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
320 spin_unlock(&root->fs_info->hash_lock);
321 csum_tree_block(root, eb, 0);
322 err:
323 free_extent_buffer(eb);
324 out:
325 return 0;
326 }
327
328 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
329 {
330 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
331
332 csum_dirty_buffer(root, page);
333 return 0;
334 }
335
336 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
337 struct extent_state *state)
338 {
339 struct extent_io_tree *tree;
340 u64 found_start;
341 int found_level;
342 unsigned long len;
343 struct extent_buffer *eb;
344 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
345 int ret = 0;
346
347 tree = &BTRFS_I(page->mapping->host)->io_tree;
348 if (page->private == EXTENT_PAGE_PRIVATE)
349 goto out;
350 if (!page->private)
351 goto out;
352 len = page->private >> 2;
353 if (len == 0) {
354 WARN_ON(1);
355 }
356 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
357
358 found_start = btrfs_header_bytenr(eb);
359 if (found_start != start) {
360 ret = -EIO;
361 goto err;
362 }
363 if (eb->first_page != page) {
364 printk("bad first page %lu %lu\n", eb->first_page->index,
365 page->index);
366 WARN_ON(1);
367 ret = -EIO;
368 goto err;
369 }
370 if (memcmp_extent_buffer(eb, root->fs_info->fsid,
371 (unsigned long)btrfs_header_fsid(eb),
372 BTRFS_FSID_SIZE)) {
373 printk("bad fsid on block %Lu\n", eb->start);
374 ret = -EIO;
375 goto err;
376 }
377 found_level = btrfs_header_level(eb);
378
379 ret = csum_tree_block(root, eb, 1);
380 if (ret)
381 ret = -EIO;
382
383 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
384 end = eb->start + end - 1;
385 err:
386 free_extent_buffer(eb);
387 out:
388 return ret;
389 }
390
391 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
392 static void end_workqueue_bio(struct bio *bio, int err)
393 #else
394 static int end_workqueue_bio(struct bio *bio,
395 unsigned int bytes_done, int err)
396 #endif
397 {
398 struct end_io_wq *end_io_wq = bio->bi_private;
399 struct btrfs_fs_info *fs_info;
400
401 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
402 if (bio->bi_size)
403 return 1;
404 #endif
405
406 fs_info = end_io_wq->info;
407 end_io_wq->error = err;
408 end_io_wq->work.func = end_workqueue_fn;
409 end_io_wq->work.flags = 0;
410 if (bio->bi_rw & (1 << BIO_RW))
411 btrfs_queue_worker(&fs_info->endio_write_workers,
412 &end_io_wq->work);
413 else
414 btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
415
416 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
417 return 0;
418 #endif
419 }
420
421 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
422 int metadata)
423 {
424 struct end_io_wq *end_io_wq;
425 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
426 if (!end_io_wq)
427 return -ENOMEM;
428
429 end_io_wq->private = bio->bi_private;
430 end_io_wq->end_io = bio->bi_end_io;
431 end_io_wq->info = info;
432 end_io_wq->error = 0;
433 end_io_wq->bio = bio;
434 end_io_wq->metadata = metadata;
435
436 bio->bi_private = end_io_wq;
437 bio->bi_end_io = end_workqueue_bio;
438 return 0;
439 }
440
441 static void run_one_async_submit(struct btrfs_work *work)
442 {
443 struct btrfs_fs_info *fs_info;
444 struct async_submit_bio *async;
445
446 async = container_of(work, struct async_submit_bio, work);
447 fs_info = BTRFS_I(async->inode)->root->fs_info;
448 atomic_dec(&fs_info->nr_async_submits);
449 async->submit_bio_hook(async->inode, async->rw, async->bio,
450 async->mirror_num);
451 kfree(async);
452 }
453
454 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
455 int rw, struct bio *bio, int mirror_num,
456 extent_submit_bio_hook_t *submit_bio_hook)
457 {
458 struct async_submit_bio *async;
459
460 async = kmalloc(sizeof(*async), GFP_NOFS);
461 if (!async)
462 return -ENOMEM;
463
464 async->inode = inode;
465 async->rw = rw;
466 async->bio = bio;
467 async->mirror_num = mirror_num;
468 async->submit_bio_hook = submit_bio_hook;
469 async->work.func = run_one_async_submit;
470 async->work.flags = 0;
471 atomic_inc(&fs_info->nr_async_submits);
472 btrfs_queue_worker(&fs_info->workers, &async->work);
473 return 0;
474 }
475
476 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
477 int mirror_num)
478 {
479 struct btrfs_root *root = BTRFS_I(inode)->root;
480 u64 offset;
481 int ret;
482
483 offset = bio->bi_sector << 9;
484
485 /*
486 * when we're called for a write, we're already in the async
487 * submission context. Just jump ingo btrfs_map_bio
488 */
489 if (rw & (1 << BIO_RW)) {
490 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
491 mirror_num, 0);
492 }
493
494 /*
495 * called for a read, do the setup so that checksum validation
496 * can happen in the async kernel threads
497 */
498 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
499 BUG_ON(ret);
500
501 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
502 }
503
504 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
505 int mirror_num)
506 {
507 /*
508 * kthread helpers are used to submit writes so that checksumming
509 * can happen in parallel across all CPUs
510 */
511 if (!(rw & (1 << BIO_RW))) {
512 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
513 }
514 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
515 inode, rw, bio, mirror_num,
516 __btree_submit_bio_hook);
517 }
518
519 static int btree_writepage(struct page *page, struct writeback_control *wbc)
520 {
521 struct extent_io_tree *tree;
522 tree = &BTRFS_I(page->mapping->host)->io_tree;
523 return extent_write_full_page(tree, page, btree_get_extent, wbc);
524 }
525
526 static int btree_writepages(struct address_space *mapping,
527 struct writeback_control *wbc)
528 {
529 struct extent_io_tree *tree;
530 tree = &BTRFS_I(mapping->host)->io_tree;
531 if (wbc->sync_mode == WB_SYNC_NONE) {
532 u64 num_dirty;
533 u64 start = 0;
534 unsigned long thresh = 96 * 1024 * 1024;
535
536 if (wbc->for_kupdate)
537 return 0;
538
539 if (current_is_pdflush()) {
540 thresh = 96 * 1024 * 1024;
541 } else {
542 thresh = 8 * 1024 * 1024;
543 }
544 num_dirty = count_range_bits(tree, &start, (u64)-1,
545 thresh, EXTENT_DIRTY);
546 if (num_dirty < thresh) {
547 return 0;
548 }
549 }
550 return extent_writepages(tree, mapping, btree_get_extent, wbc);
551 }
552
553 int btree_readpage(struct file *file, struct page *page)
554 {
555 struct extent_io_tree *tree;
556 tree = &BTRFS_I(page->mapping->host)->io_tree;
557 return extent_read_full_page(tree, page, btree_get_extent);
558 }
559
560 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
561 {
562 struct extent_io_tree *tree;
563 struct extent_map_tree *map;
564 int ret;
565
566 tree = &BTRFS_I(page->mapping->host)->io_tree;
567 map = &BTRFS_I(page->mapping->host)->extent_tree;
568
569 ret = try_release_extent_state(map, tree, page, gfp_flags);
570 if (!ret) {
571 return 0;
572 }
573
574 ret = try_release_extent_buffer(tree, page);
575 if (ret == 1) {
576 ClearPagePrivate(page);
577 set_page_private(page, 0);
578 page_cache_release(page);
579 }
580
581 return ret;
582 }
583
584 static void btree_invalidatepage(struct page *page, unsigned long offset)
585 {
586 struct extent_io_tree *tree;
587 tree = &BTRFS_I(page->mapping->host)->io_tree;
588 extent_invalidatepage(tree, page, offset);
589 btree_releasepage(page, GFP_NOFS);
590 if (PagePrivate(page)) {
591 printk("warning page private not zero on page %Lu\n",
592 page_offset(page));
593 ClearPagePrivate(page);
594 set_page_private(page, 0);
595 page_cache_release(page);
596 }
597 }
598
599 #if 0
600 static int btree_writepage(struct page *page, struct writeback_control *wbc)
601 {
602 struct buffer_head *bh;
603 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
604 struct buffer_head *head;
605 if (!page_has_buffers(page)) {
606 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
607 (1 << BH_Dirty)|(1 << BH_Uptodate));
608 }
609 head = page_buffers(page);
610 bh = head;
611 do {
612 if (buffer_dirty(bh))
613 csum_tree_block(root, bh, 0);
614 bh = bh->b_this_page;
615 } while (bh != head);
616 return block_write_full_page(page, btree_get_block, wbc);
617 }
618 #endif
619
620 static struct address_space_operations btree_aops = {
621 .readpage = btree_readpage,
622 .writepage = btree_writepage,
623 .writepages = btree_writepages,
624 .releasepage = btree_releasepage,
625 .invalidatepage = btree_invalidatepage,
626 .sync_page = block_sync_page,
627 };
628
629 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
630 u64 parent_transid)
631 {
632 struct extent_buffer *buf = NULL;
633 struct inode *btree_inode = root->fs_info->btree_inode;
634 int ret = 0;
635
636 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
637 if (!buf)
638 return 0;
639 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
640 buf, 0, 0, btree_get_extent, 0);
641 free_extent_buffer(buf);
642 return ret;
643 }
644
645 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
646 u64 bytenr, u32 blocksize)
647 {
648 struct inode *btree_inode = root->fs_info->btree_inode;
649 struct extent_buffer *eb;
650 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
651 bytenr, blocksize, GFP_NOFS);
652 return eb;
653 }
654
655 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
656 u64 bytenr, u32 blocksize)
657 {
658 struct inode *btree_inode = root->fs_info->btree_inode;
659 struct extent_buffer *eb;
660
661 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
662 bytenr, blocksize, NULL, GFP_NOFS);
663 return eb;
664 }
665
666
667 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
668 u32 blocksize, u64 parent_transid)
669 {
670 struct extent_buffer *buf = NULL;
671 struct inode *btree_inode = root->fs_info->btree_inode;
672 struct extent_io_tree *io_tree;
673 int ret;
674
675 io_tree = &BTRFS_I(btree_inode)->io_tree;
676
677 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
678 if (!buf)
679 return NULL;
680
681 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
682
683 if (ret == 0) {
684 buf->flags |= EXTENT_UPTODATE;
685 }
686 return buf;
687
688 }
689
690 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
691 struct extent_buffer *buf)
692 {
693 struct inode *btree_inode = root->fs_info->btree_inode;
694 if (btrfs_header_generation(buf) ==
695 root->fs_info->running_transaction->transid) {
696 WARN_ON(!btrfs_tree_locked(buf));
697 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
698 buf);
699 }
700 return 0;
701 }
702
703 int wait_on_tree_block_writeback(struct btrfs_root *root,
704 struct extent_buffer *buf)
705 {
706 struct inode *btree_inode = root->fs_info->btree_inode;
707 wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
708 buf);
709 return 0;
710 }
711
712 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
713 u32 stripesize, struct btrfs_root *root,
714 struct btrfs_fs_info *fs_info,
715 u64 objectid)
716 {
717 root->node = NULL;
718 root->inode = NULL;
719 root->commit_root = NULL;
720 root->ref_tree = NULL;
721 root->sectorsize = sectorsize;
722 root->nodesize = nodesize;
723 root->leafsize = leafsize;
724 root->stripesize = stripesize;
725 root->ref_cows = 0;
726 root->track_dirty = 0;
727
728 root->fs_info = fs_info;
729 root->objectid = objectid;
730 root->last_trans = 0;
731 root->highest_inode = 0;
732 root->last_inode_alloc = 0;
733 root->name = NULL;
734 root->in_sysfs = 0;
735
736 INIT_LIST_HEAD(&root->dirty_list);
737 INIT_LIST_HEAD(&root->orphan_list);
738 INIT_LIST_HEAD(&root->dead_list);
739 spin_lock_init(&root->node_lock);
740 spin_lock_init(&root->list_lock);
741 mutex_init(&root->objectid_mutex);
742
743 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
744 root->ref_tree = &root->ref_tree_struct;
745
746 memset(&root->root_key, 0, sizeof(root->root_key));
747 memset(&root->root_item, 0, sizeof(root->root_item));
748 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
749 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
750 root->defrag_trans_start = fs_info->generation;
751 init_completion(&root->kobj_unregister);
752 root->defrag_running = 0;
753 root->defrag_level = 0;
754 root->root_key.objectid = objectid;
755 return 0;
756 }
757
758 static int find_and_setup_root(struct btrfs_root *tree_root,
759 struct btrfs_fs_info *fs_info,
760 u64 objectid,
761 struct btrfs_root *root)
762 {
763 int ret;
764 u32 blocksize;
765
766 __setup_root(tree_root->nodesize, tree_root->leafsize,
767 tree_root->sectorsize, tree_root->stripesize,
768 root, fs_info, objectid);
769 ret = btrfs_find_last_root(tree_root, objectid,
770 &root->root_item, &root->root_key);
771 BUG_ON(ret);
772
773 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
774 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
775 blocksize, 0);
776 BUG_ON(!root->node);
777 return 0;
778 }
779
780 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
781 struct btrfs_key *location)
782 {
783 struct btrfs_root *root;
784 struct btrfs_root *tree_root = fs_info->tree_root;
785 struct btrfs_path *path;
786 struct extent_buffer *l;
787 u64 highest_inode;
788 u32 blocksize;
789 int ret = 0;
790
791 root = kzalloc(sizeof(*root), GFP_NOFS);
792 if (!root)
793 return ERR_PTR(-ENOMEM);
794 if (location->offset == (u64)-1) {
795 ret = find_and_setup_root(tree_root, fs_info,
796 location->objectid, root);
797 if (ret) {
798 kfree(root);
799 return ERR_PTR(ret);
800 }
801 goto insert;
802 }
803
804 __setup_root(tree_root->nodesize, tree_root->leafsize,
805 tree_root->sectorsize, tree_root->stripesize,
806 root, fs_info, location->objectid);
807
808 path = btrfs_alloc_path();
809 BUG_ON(!path);
810 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
811 if (ret != 0) {
812 if (ret > 0)
813 ret = -ENOENT;
814 goto out;
815 }
816 l = path->nodes[0];
817 read_extent_buffer(l, &root->root_item,
818 btrfs_item_ptr_offset(l, path->slots[0]),
819 sizeof(root->root_item));
820 memcpy(&root->root_key, location, sizeof(*location));
821 ret = 0;
822 out:
823 btrfs_release_path(root, path);
824 btrfs_free_path(path);
825 if (ret) {
826 kfree(root);
827 return ERR_PTR(ret);
828 }
829 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
830 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
831 blocksize, 0);
832 BUG_ON(!root->node);
833 insert:
834 root->ref_cows = 1;
835 ret = btrfs_find_highest_inode(root, &highest_inode);
836 if (ret == 0) {
837 root->highest_inode = highest_inode;
838 root->last_inode_alloc = highest_inode;
839 }
840 return root;
841 }
842
843 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
844 u64 root_objectid)
845 {
846 struct btrfs_root *root;
847
848 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
849 return fs_info->tree_root;
850 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
851 return fs_info->extent_root;
852
853 root = radix_tree_lookup(&fs_info->fs_roots_radix,
854 (unsigned long)root_objectid);
855 return root;
856 }
857
858 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
859 struct btrfs_key *location)
860 {
861 struct btrfs_root *root;
862 int ret;
863
864 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
865 return fs_info->tree_root;
866 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
867 return fs_info->extent_root;
868 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
869 return fs_info->chunk_root;
870 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
871 return fs_info->dev_root;
872
873 root = radix_tree_lookup(&fs_info->fs_roots_radix,
874 (unsigned long)location->objectid);
875 if (root)
876 return root;
877
878 root = btrfs_read_fs_root_no_radix(fs_info, location);
879 if (IS_ERR(root))
880 return root;
881 ret = radix_tree_insert(&fs_info->fs_roots_radix,
882 (unsigned long)root->root_key.objectid,
883 root);
884 if (ret) {
885 free_extent_buffer(root->node);
886 kfree(root);
887 return ERR_PTR(ret);
888 }
889 ret = btrfs_find_dead_roots(fs_info->tree_root,
890 root->root_key.objectid, root);
891 BUG_ON(ret);
892
893 return root;
894 }
895
896 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
897 struct btrfs_key *location,
898 const char *name, int namelen)
899 {
900 struct btrfs_root *root;
901 int ret;
902
903 root = btrfs_read_fs_root_no_name(fs_info, location);
904 if (!root)
905 return NULL;
906
907 if (root->in_sysfs)
908 return root;
909
910 ret = btrfs_set_root_name(root, name, namelen);
911 if (ret) {
912 free_extent_buffer(root->node);
913 kfree(root);
914 return ERR_PTR(ret);
915 }
916
917 ret = btrfs_sysfs_add_root(root);
918 if (ret) {
919 free_extent_buffer(root->node);
920 kfree(root->name);
921 kfree(root);
922 return ERR_PTR(ret);
923 }
924 root->in_sysfs = 1;
925 return root;
926 }
927 #if 0
928 static int add_hasher(struct btrfs_fs_info *info, char *type) {
929 struct btrfs_hasher *hasher;
930
931 hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
932 if (!hasher)
933 return -ENOMEM;
934 hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
935 if (!hasher->hash_tfm) {
936 kfree(hasher);
937 return -EINVAL;
938 }
939 spin_lock(&info->hash_lock);
940 list_add(&hasher->list, &info->hashers);
941 spin_unlock(&info->hash_lock);
942 return 0;
943 }
944 #endif
945
946 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
947 {
948 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
949 int ret = 0;
950 int limit = 256 * info->fs_devices->open_devices;
951 struct list_head *cur;
952 struct btrfs_device *device;
953 struct backing_dev_info *bdi;
954
955 if ((bdi_bits & (1 << BDI_write_congested)) &&
956 atomic_read(&info->nr_async_submits) > limit) {
957 return 1;
958 }
959
960 list_for_each(cur, &info->fs_devices->devices) {
961 device = list_entry(cur, struct btrfs_device, dev_list);
962 if (!device->bdev)
963 continue;
964 bdi = blk_get_backing_dev_info(device->bdev);
965 if (bdi && bdi_congested(bdi, bdi_bits)) {
966 ret = 1;
967 break;
968 }
969 }
970 return ret;
971 }
972
973 /*
974 * this unplugs every device on the box, and it is only used when page
975 * is null
976 */
977 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
978 {
979 struct list_head *cur;
980 struct btrfs_device *device;
981 struct btrfs_fs_info *info;
982
983 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
984 list_for_each(cur, &info->fs_devices->devices) {
985 device = list_entry(cur, struct btrfs_device, dev_list);
986 bdi = blk_get_backing_dev_info(device->bdev);
987 if (bdi->unplug_io_fn) {
988 bdi->unplug_io_fn(bdi, page);
989 }
990 }
991 }
992
993 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
994 {
995 struct inode *inode;
996 struct extent_map_tree *em_tree;
997 struct extent_map *em;
998 struct address_space *mapping;
999 u64 offset;
1000
1001 /* the generic O_DIRECT read code does this */
1002 if (!page) {
1003 __unplug_io_fn(bdi, page);
1004 return;
1005 }
1006
1007 /*
1008 * page->mapping may change at any time. Get a consistent copy
1009 * and use that for everything below
1010 */
1011 smp_mb();
1012 mapping = page->mapping;
1013 if (!mapping)
1014 return;
1015
1016 inode = mapping->host;
1017 offset = page_offset(page);
1018
1019 em_tree = &BTRFS_I(inode)->extent_tree;
1020 spin_lock(&em_tree->lock);
1021 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1022 spin_unlock(&em_tree->lock);
1023 if (!em) {
1024 __unplug_io_fn(bdi, page);
1025 return;
1026 }
1027
1028 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1029 free_extent_map(em);
1030 __unplug_io_fn(bdi, page);
1031 return;
1032 }
1033 offset = offset - em->start;
1034 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1035 em->block_start + offset, page);
1036 free_extent_map(em);
1037 }
1038
1039 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1040 {
1041 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1042 bdi_init(bdi);
1043 #endif
1044 bdi->ra_pages = default_backing_dev_info.ra_pages;
1045 bdi->state = 0;
1046 bdi->capabilities = default_backing_dev_info.capabilities;
1047 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1048 bdi->unplug_io_data = info;
1049 bdi->congested_fn = btrfs_congested_fn;
1050 bdi->congested_data = info;
1051 return 0;
1052 }
1053
1054 static int bio_ready_for_csum(struct bio *bio)
1055 {
1056 u64 length = 0;
1057 u64 buf_len = 0;
1058 u64 start = 0;
1059 struct page *page;
1060 struct extent_io_tree *io_tree = NULL;
1061 struct btrfs_fs_info *info = NULL;
1062 struct bio_vec *bvec;
1063 int i;
1064 int ret;
1065
1066 bio_for_each_segment(bvec, bio, i) {
1067 page = bvec->bv_page;
1068 if (page->private == EXTENT_PAGE_PRIVATE) {
1069 length += bvec->bv_len;
1070 continue;
1071 }
1072 if (!page->private) {
1073 length += bvec->bv_len;
1074 continue;
1075 }
1076 length = bvec->bv_len;
1077 buf_len = page->private >> 2;
1078 start = page_offset(page) + bvec->bv_offset;
1079 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1080 info = BTRFS_I(page->mapping->host)->root->fs_info;
1081 }
1082 /* are we fully contained in this bio? */
1083 if (buf_len <= length)
1084 return 1;
1085
1086 ret = extent_range_uptodate(io_tree, start + length,
1087 start + buf_len - 1);
1088 if (ret == 1)
1089 return ret;
1090 return ret;
1091 }
1092
1093 /*
1094 * called by the kthread helper functions to finally call the bio end_io
1095 * functions. This is where read checksum verification actually happens
1096 */
1097 static void end_workqueue_fn(struct btrfs_work *work)
1098 {
1099 struct bio *bio;
1100 struct end_io_wq *end_io_wq;
1101 struct btrfs_fs_info *fs_info;
1102 int error;
1103
1104 end_io_wq = container_of(work, struct end_io_wq, work);
1105 bio = end_io_wq->bio;
1106 fs_info = end_io_wq->info;
1107
1108 /* metadata bios are special because the whole tree block must
1109 * be checksummed at once. This makes sure the entire block is in
1110 * ram and up to date before trying to verify things. For
1111 * blocksize <= pagesize, it is basically a noop
1112 */
1113 if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1114 btrfs_queue_worker(&fs_info->endio_workers,
1115 &end_io_wq->work);
1116 return;
1117 }
1118 error = end_io_wq->error;
1119 bio->bi_private = end_io_wq->private;
1120 bio->bi_end_io = end_io_wq->end_io;
1121 kfree(end_io_wq);
1122 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1123 bio_endio(bio, bio->bi_size, error);
1124 #else
1125 bio_endio(bio, error);
1126 #endif
1127 }
1128
1129 static int cleaner_kthread(void *arg)
1130 {
1131 struct btrfs_root *root = arg;
1132
1133 do {
1134 smp_mb();
1135 if (root->fs_info->closing)
1136 break;
1137
1138 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1139 mutex_lock(&root->fs_info->cleaner_mutex);
1140 btrfs_clean_old_snapshots(root);
1141 mutex_unlock(&root->fs_info->cleaner_mutex);
1142
1143 if (freezing(current)) {
1144 refrigerator();
1145 } else {
1146 smp_mb();
1147 if (root->fs_info->closing)
1148 break;
1149 set_current_state(TASK_INTERRUPTIBLE);
1150 schedule();
1151 __set_current_state(TASK_RUNNING);
1152 }
1153 } while (!kthread_should_stop());
1154 return 0;
1155 }
1156
1157 static int transaction_kthread(void *arg)
1158 {
1159 struct btrfs_root *root = arg;
1160 struct btrfs_trans_handle *trans;
1161 struct btrfs_transaction *cur;
1162 unsigned long now;
1163 unsigned long delay;
1164 int ret;
1165
1166 do {
1167 smp_mb();
1168 if (root->fs_info->closing)
1169 break;
1170
1171 delay = HZ * 30;
1172 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1173 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1174
1175 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1176 printk("btrfs: total reference cache size %Lu\n",
1177 root->fs_info->total_ref_cache_size);
1178 }
1179
1180 mutex_lock(&root->fs_info->trans_mutex);
1181 cur = root->fs_info->running_transaction;
1182 if (!cur) {
1183 mutex_unlock(&root->fs_info->trans_mutex);
1184 goto sleep;
1185 }
1186
1187 now = get_seconds();
1188 if (now < cur->start_time || now - cur->start_time < 30) {
1189 mutex_unlock(&root->fs_info->trans_mutex);
1190 delay = HZ * 5;
1191 goto sleep;
1192 }
1193 mutex_unlock(&root->fs_info->trans_mutex);
1194 trans = btrfs_start_transaction(root, 1);
1195 ret = btrfs_commit_transaction(trans, root);
1196 sleep:
1197 wake_up_process(root->fs_info->cleaner_kthread);
1198 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1199
1200 if (freezing(current)) {
1201 refrigerator();
1202 } else {
1203 if (root->fs_info->closing)
1204 break;
1205 set_current_state(TASK_INTERRUPTIBLE);
1206 schedule_timeout(delay);
1207 __set_current_state(TASK_RUNNING);
1208 }
1209 } while (!kthread_should_stop());
1210 return 0;
1211 }
1212
1213 struct btrfs_root *open_ctree(struct super_block *sb,
1214 struct btrfs_fs_devices *fs_devices,
1215 char *options)
1216 {
1217 u32 sectorsize;
1218 u32 nodesize;
1219 u32 leafsize;
1220 u32 blocksize;
1221 u32 stripesize;
1222 struct buffer_head *bh;
1223 struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
1224 GFP_NOFS);
1225 struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
1226 GFP_NOFS);
1227 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1228 GFP_NOFS);
1229 struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
1230 GFP_NOFS);
1231 struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
1232 GFP_NOFS);
1233 int ret;
1234 int err = -EINVAL;
1235
1236 struct btrfs_super_block *disk_super;
1237
1238 if (!extent_root || !tree_root || !fs_info) {
1239 err = -ENOMEM;
1240 goto fail;
1241 }
1242 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1243 INIT_LIST_HEAD(&fs_info->trans_list);
1244 INIT_LIST_HEAD(&fs_info->dead_roots);
1245 INIT_LIST_HEAD(&fs_info->hashers);
1246 spin_lock_init(&fs_info->hash_lock);
1247 spin_lock_init(&fs_info->delalloc_lock);
1248 spin_lock_init(&fs_info->new_trans_lock);
1249 spin_lock_init(&fs_info->ref_cache_lock);
1250
1251 init_completion(&fs_info->kobj_unregister);
1252 fs_info->tree_root = tree_root;
1253 fs_info->extent_root = extent_root;
1254 fs_info->chunk_root = chunk_root;
1255 fs_info->dev_root = dev_root;
1256 fs_info->fs_devices = fs_devices;
1257 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1258 INIT_LIST_HEAD(&fs_info->space_info);
1259 btrfs_mapping_init(&fs_info->mapping_tree);
1260 atomic_set(&fs_info->nr_async_submits, 0);
1261 atomic_set(&fs_info->throttles, 0);
1262 atomic_set(&fs_info->throttle_gen, 0);
1263 fs_info->sb = sb;
1264 fs_info->max_extent = (u64)-1;
1265 fs_info->max_inline = 8192 * 1024;
1266 setup_bdi(fs_info, &fs_info->bdi);
1267 fs_info->btree_inode = new_inode(sb);
1268 fs_info->btree_inode->i_ino = 1;
1269 fs_info->btree_inode->i_nlink = 1;
1270 fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1271
1272 INIT_LIST_HEAD(&fs_info->ordered_extents);
1273 spin_lock_init(&fs_info->ordered_extent_lock);
1274
1275 sb->s_blocksize = 4096;
1276 sb->s_blocksize_bits = blksize_bits(4096);
1277
1278 /*
1279 * we set the i_size on the btree inode to the max possible int.
1280 * the real end of the address space is determined by all of
1281 * the devices in the system
1282 */
1283 fs_info->btree_inode->i_size = OFFSET_MAX;
1284 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1285 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1286
1287 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1288 fs_info->btree_inode->i_mapping,
1289 GFP_NOFS);
1290 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1291 GFP_NOFS);
1292
1293 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1294
1295 extent_io_tree_init(&fs_info->free_space_cache,
1296 fs_info->btree_inode->i_mapping, GFP_NOFS);
1297 extent_io_tree_init(&fs_info->block_group_cache,
1298 fs_info->btree_inode->i_mapping, GFP_NOFS);
1299 extent_io_tree_init(&fs_info->pinned_extents,
1300 fs_info->btree_inode->i_mapping, GFP_NOFS);
1301 extent_io_tree_init(&fs_info->pending_del,
1302 fs_info->btree_inode->i_mapping, GFP_NOFS);
1303 extent_io_tree_init(&fs_info->extent_ins,
1304 fs_info->btree_inode->i_mapping, GFP_NOFS);
1305 fs_info->do_barriers = 1;
1306
1307 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1308 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1309 sizeof(struct btrfs_key));
1310 insert_inode_hash(fs_info->btree_inode);
1311 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1312
1313 mutex_init(&fs_info->trans_mutex);
1314 mutex_init(&fs_info->drop_mutex);
1315 mutex_init(&fs_info->alloc_mutex);
1316 mutex_init(&fs_info->chunk_mutex);
1317 mutex_init(&fs_info->transaction_kthread_mutex);
1318 mutex_init(&fs_info->cleaner_mutex);
1319 mutex_init(&fs_info->volume_mutex);
1320 init_waitqueue_head(&fs_info->transaction_throttle);
1321 init_waitqueue_head(&fs_info->transaction_wait);
1322
1323 #if 0
1324 ret = add_hasher(fs_info, "crc32c");
1325 if (ret) {
1326 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1327 err = -ENOMEM;
1328 goto fail_iput;
1329 }
1330 #endif
1331 __setup_root(4096, 4096, 4096, 4096, tree_root,
1332 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1333
1334
1335 bh = __bread(fs_devices->latest_bdev,
1336 BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1337 if (!bh)
1338 goto fail_iput;
1339
1340 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1341 brelse(bh);
1342
1343 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1344
1345 disk_super = &fs_info->super_copy;
1346 if (!btrfs_super_root(disk_super))
1347 goto fail_sb_buffer;
1348
1349 err = btrfs_parse_options(tree_root, options);
1350 if (err)
1351 goto fail_sb_buffer;
1352
1353 /*
1354 * we need to start all the end_io workers up front because the
1355 * queue work function gets called at interrupt time, and so it
1356 * cannot dynamically grow.
1357 */
1358 btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size);
1359 btrfs_init_workers(&fs_info->submit_workers, fs_info->thread_pool_size);
1360 btrfs_init_workers(&fs_info->fixup_workers, 1);
1361 btrfs_init_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1362 btrfs_init_workers(&fs_info->endio_write_workers,
1363 fs_info->thread_pool_size);
1364 btrfs_start_workers(&fs_info->workers, 1);
1365 btrfs_start_workers(&fs_info->submit_workers, 1);
1366 btrfs_start_workers(&fs_info->fixup_workers, 1);
1367 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1368 btrfs_start_workers(&fs_info->endio_write_workers,
1369 fs_info->thread_pool_size);
1370
1371 err = -EINVAL;
1372 if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1373 printk("Btrfs: wanted %llu devices, but found %llu\n",
1374 (unsigned long long)btrfs_super_num_devices(disk_super),
1375 (unsigned long long)fs_devices->open_devices);
1376 if (btrfs_test_opt(tree_root, DEGRADED))
1377 printk("continuing in degraded mode\n");
1378 else {
1379 goto fail_sb_buffer;
1380 }
1381 }
1382
1383 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1384
1385 nodesize = btrfs_super_nodesize(disk_super);
1386 leafsize = btrfs_super_leafsize(disk_super);
1387 sectorsize = btrfs_super_sectorsize(disk_super);
1388 stripesize = btrfs_super_stripesize(disk_super);
1389 tree_root->nodesize = nodesize;
1390 tree_root->leafsize = leafsize;
1391 tree_root->sectorsize = sectorsize;
1392 tree_root->stripesize = stripesize;
1393
1394 sb->s_blocksize = sectorsize;
1395 sb->s_blocksize_bits = blksize_bits(sectorsize);
1396
1397 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1398 sizeof(disk_super->magic))) {
1399 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1400 goto fail_sb_buffer;
1401 }
1402
1403 mutex_lock(&fs_info->chunk_mutex);
1404 ret = btrfs_read_sys_array(tree_root);
1405 mutex_unlock(&fs_info->chunk_mutex);
1406 if (ret) {
1407 printk("btrfs: failed to read the system array on %s\n",
1408 sb->s_id);
1409 goto fail_sys_array;
1410 }
1411
1412 blocksize = btrfs_level_size(tree_root,
1413 btrfs_super_chunk_root_level(disk_super));
1414
1415 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1416 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1417
1418 chunk_root->node = read_tree_block(chunk_root,
1419 btrfs_super_chunk_root(disk_super),
1420 blocksize, 0);
1421 BUG_ON(!chunk_root->node);
1422
1423 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1424 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1425 BTRFS_UUID_SIZE);
1426
1427 mutex_lock(&fs_info->chunk_mutex);
1428 ret = btrfs_read_chunk_tree(chunk_root);
1429 mutex_unlock(&fs_info->chunk_mutex);
1430 BUG_ON(ret);
1431
1432 btrfs_close_extra_devices(fs_devices);
1433
1434 blocksize = btrfs_level_size(tree_root,
1435 btrfs_super_root_level(disk_super));
1436
1437
1438 tree_root->node = read_tree_block(tree_root,
1439 btrfs_super_root(disk_super),
1440 blocksize, 0);
1441 if (!tree_root->node)
1442 goto fail_sb_buffer;
1443
1444
1445 ret = find_and_setup_root(tree_root, fs_info,
1446 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1447 if (ret)
1448 goto fail_tree_root;
1449 extent_root->track_dirty = 1;
1450
1451 ret = find_and_setup_root(tree_root, fs_info,
1452 BTRFS_DEV_TREE_OBJECTID, dev_root);
1453 dev_root->track_dirty = 1;
1454
1455 if (ret)
1456 goto fail_extent_root;
1457
1458 btrfs_read_block_groups(extent_root);
1459
1460 fs_info->generation = btrfs_super_generation(disk_super) + 1;
1461 fs_info->data_alloc_profile = (u64)-1;
1462 fs_info->metadata_alloc_profile = (u64)-1;
1463 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1464 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1465 "btrfs-cleaner");
1466 if (!fs_info->cleaner_kthread)
1467 goto fail_extent_root;
1468
1469 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1470 tree_root,
1471 "btrfs-transaction");
1472 if (!fs_info->transaction_kthread)
1473 goto fail_cleaner;
1474
1475
1476 return tree_root;
1477
1478 fail_cleaner:
1479 kthread_stop(fs_info->cleaner_kthread);
1480 fail_extent_root:
1481 free_extent_buffer(extent_root->node);
1482 fail_tree_root:
1483 free_extent_buffer(tree_root->node);
1484 fail_sys_array:
1485 fail_sb_buffer:
1486 btrfs_stop_workers(&fs_info->fixup_workers);
1487 btrfs_stop_workers(&fs_info->workers);
1488 btrfs_stop_workers(&fs_info->endio_workers);
1489 btrfs_stop_workers(&fs_info->endio_write_workers);
1490 btrfs_stop_workers(&fs_info->submit_workers);
1491 fail_iput:
1492 iput(fs_info->btree_inode);
1493 fail:
1494 btrfs_close_devices(fs_info->fs_devices);
1495 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1496
1497 kfree(extent_root);
1498 kfree(tree_root);
1499 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1500 bdi_destroy(&fs_info->bdi);
1501 #endif
1502 kfree(fs_info);
1503 return ERR_PTR(err);
1504 }
1505
1506 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1507 {
1508 char b[BDEVNAME_SIZE];
1509
1510 if (uptodate) {
1511 set_buffer_uptodate(bh);
1512 } else {
1513 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1514 printk(KERN_WARNING "lost page write due to "
1515 "I/O error on %s\n",
1516 bdevname(bh->b_bdev, b));
1517 }
1518 /* note, we dont' set_buffer_write_io_error because we have
1519 * our own ways of dealing with the IO errors
1520 */
1521 clear_buffer_uptodate(bh);
1522 }
1523 unlock_buffer(bh);
1524 put_bh(bh);
1525 }
1526
1527 int write_all_supers(struct btrfs_root *root)
1528 {
1529 struct list_head *cur;
1530 struct list_head *head = &root->fs_info->fs_devices->devices;
1531 struct btrfs_device *dev;
1532 struct btrfs_super_block *sb;
1533 struct btrfs_dev_item *dev_item;
1534 struct buffer_head *bh;
1535 int ret;
1536 int do_barriers;
1537 int max_errors;
1538 int total_errors = 0;
1539 u32 crc;
1540 u64 flags;
1541
1542 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1543 do_barriers = !btrfs_test_opt(root, NOBARRIER);
1544
1545 sb = &root->fs_info->super_for_commit;
1546 dev_item = &sb->dev_item;
1547 list_for_each(cur, head) {
1548 dev = list_entry(cur, struct btrfs_device, dev_list);
1549 if (!dev->bdev) {
1550 total_errors++;
1551 continue;
1552 }
1553 if (!dev->in_fs_metadata)
1554 continue;
1555
1556 btrfs_set_stack_device_type(dev_item, dev->type);
1557 btrfs_set_stack_device_id(dev_item, dev->devid);
1558 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1559 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1560 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1561 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1562 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1563 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1564 flags = btrfs_super_flags(sb);
1565 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1566
1567
1568 crc = ~(u32)0;
1569 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1570 BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1571 btrfs_csum_final(crc, sb->csum);
1572
1573 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1574 BTRFS_SUPER_INFO_SIZE);
1575
1576 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1577 dev->pending_io = bh;
1578
1579 get_bh(bh);
1580 set_buffer_uptodate(bh);
1581 lock_buffer(bh);
1582 bh->b_end_io = btrfs_end_buffer_write_sync;
1583
1584 if (do_barriers && dev->barriers) {
1585 ret = submit_bh(WRITE_BARRIER, bh);
1586 if (ret == -EOPNOTSUPP) {
1587 printk("btrfs: disabling barriers on dev %s\n",
1588 dev->name);
1589 set_buffer_uptodate(bh);
1590 dev->barriers = 0;
1591 get_bh(bh);
1592 lock_buffer(bh);
1593 ret = submit_bh(WRITE, bh);
1594 }
1595 } else {
1596 ret = submit_bh(WRITE, bh);
1597 }
1598 if (ret)
1599 total_errors++;
1600 }
1601 if (total_errors > max_errors) {
1602 printk("btrfs: %d errors while writing supers\n", total_errors);
1603 BUG();
1604 }
1605 total_errors = 0;
1606
1607 list_for_each(cur, head) {
1608 dev = list_entry(cur, struct btrfs_device, dev_list);
1609 if (!dev->bdev)
1610 continue;
1611 if (!dev->in_fs_metadata)
1612 continue;
1613
1614 BUG_ON(!dev->pending_io);
1615 bh = dev->pending_io;
1616 wait_on_buffer(bh);
1617 if (!buffer_uptodate(dev->pending_io)) {
1618 if (do_barriers && dev->barriers) {
1619 printk("btrfs: disabling barriers on dev %s\n",
1620 dev->name);
1621 set_buffer_uptodate(bh);
1622 get_bh(bh);
1623 lock_buffer(bh);
1624 dev->barriers = 0;
1625 ret = submit_bh(WRITE, bh);
1626 BUG_ON(ret);
1627 wait_on_buffer(bh);
1628 if (!buffer_uptodate(bh))
1629 total_errors++;
1630 } else {
1631 total_errors++;
1632 }
1633
1634 }
1635 dev->pending_io = NULL;
1636 brelse(bh);
1637 }
1638 if (total_errors > max_errors) {
1639 printk("btrfs: %d errors while writing supers\n", total_errors);
1640 BUG();
1641 }
1642 return 0;
1643 }
1644
1645 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1646 *root)
1647 {
1648 int ret;
1649
1650 ret = write_all_supers(root);
1651 return ret;
1652 }
1653
1654 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1655 {
1656 radix_tree_delete(&fs_info->fs_roots_radix,
1657 (unsigned long)root->root_key.objectid);
1658 if (root->in_sysfs)
1659 btrfs_sysfs_del_root(root);
1660 if (root->inode)
1661 iput(root->inode);
1662 if (root->node)
1663 free_extent_buffer(root->node);
1664 if (root->commit_root)
1665 free_extent_buffer(root->commit_root);
1666 if (root->name)
1667 kfree(root->name);
1668 kfree(root);
1669 return 0;
1670 }
1671
1672 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1673 {
1674 int ret;
1675 struct btrfs_root *gang[8];
1676 int i;
1677
1678 while(1) {
1679 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1680 (void **)gang, 0,
1681 ARRAY_SIZE(gang));
1682 if (!ret)
1683 break;
1684 for (i = 0; i < ret; i++)
1685 btrfs_free_fs_root(fs_info, gang[i]);
1686 }
1687 return 0;
1688 }
1689
1690 int close_ctree(struct btrfs_root *root)
1691 {
1692 int ret;
1693 struct btrfs_trans_handle *trans;
1694 struct btrfs_fs_info *fs_info = root->fs_info;
1695
1696 fs_info->closing = 1;
1697 smp_mb();
1698
1699 kthread_stop(root->fs_info->transaction_kthread);
1700 kthread_stop(root->fs_info->cleaner_kthread);
1701
1702 btrfs_clean_old_snapshots(root);
1703 trans = btrfs_start_transaction(root, 1);
1704 ret = btrfs_commit_transaction(trans, root);
1705 /* run commit again to drop the original snapshot */
1706 trans = btrfs_start_transaction(root, 1);
1707 btrfs_commit_transaction(trans, root);
1708 ret = btrfs_write_and_wait_transaction(NULL, root);
1709 BUG_ON(ret);
1710
1711 write_ctree_super(NULL, root);
1712
1713 if (fs_info->delalloc_bytes) {
1714 printk("btrfs: at unmount delalloc count %Lu\n",
1715 fs_info->delalloc_bytes);
1716 }
1717 if (fs_info->total_ref_cache_size) {
1718 printk("btrfs: at umount reference cache size %Lu\n",
1719 fs_info->total_ref_cache_size);
1720 }
1721
1722 if (fs_info->extent_root->node)
1723 free_extent_buffer(fs_info->extent_root->node);
1724
1725 if (fs_info->tree_root->node)
1726 free_extent_buffer(fs_info->tree_root->node);
1727
1728 if (root->fs_info->chunk_root->node);
1729 free_extent_buffer(root->fs_info->chunk_root->node);
1730
1731 if (root->fs_info->dev_root->node);
1732 free_extent_buffer(root->fs_info->dev_root->node);
1733
1734 btrfs_free_block_groups(root->fs_info);
1735 del_fs_roots(fs_info);
1736
1737 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1738
1739 truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1740
1741 btrfs_stop_workers(&fs_info->fixup_workers);
1742 btrfs_stop_workers(&fs_info->workers);
1743 btrfs_stop_workers(&fs_info->endio_workers);
1744 btrfs_stop_workers(&fs_info->endio_write_workers);
1745 btrfs_stop_workers(&fs_info->submit_workers);
1746
1747 iput(fs_info->btree_inode);
1748 #if 0
1749 while(!list_empty(&fs_info->hashers)) {
1750 struct btrfs_hasher *hasher;
1751 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1752 hashers);
1753 list_del(&hasher->hashers);
1754 crypto_free_hash(&fs_info->hash_tfm);
1755 kfree(hasher);
1756 }
1757 #endif
1758 btrfs_close_devices(fs_info->fs_devices);
1759 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1760
1761 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1762 bdi_destroy(&fs_info->bdi);
1763 #endif
1764
1765 kfree(fs_info->extent_root);
1766 kfree(fs_info->tree_root);
1767 kfree(fs_info->chunk_root);
1768 kfree(fs_info->dev_root);
1769 return 0;
1770 }
1771
1772 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1773 {
1774 int ret;
1775 struct inode *btree_inode = buf->first_page->mapping->host;
1776
1777 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1778 if (!ret)
1779 return ret;
1780
1781 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1782 parent_transid);
1783 return !ret;
1784 }
1785
1786 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1787 {
1788 struct inode *btree_inode = buf->first_page->mapping->host;
1789 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1790 buf);
1791 }
1792
1793 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1794 {
1795 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1796 u64 transid = btrfs_header_generation(buf);
1797 struct inode *btree_inode = root->fs_info->btree_inode;
1798
1799 WARN_ON(!btrfs_tree_locked(buf));
1800 if (transid != root->fs_info->generation) {
1801 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1802 (unsigned long long)buf->start,
1803 transid, root->fs_info->generation);
1804 WARN_ON(1);
1805 }
1806 set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1807 }
1808
1809 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1810 {
1811 /*
1812 * looks as though older kernels can get into trouble with
1813 * this code, they end up stuck in balance_dirty_pages forever
1814 */
1815 struct extent_io_tree *tree;
1816 u64 num_dirty;
1817 u64 start = 0;
1818 unsigned long thresh = 16 * 1024 * 1024;
1819 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1820
1821 if (current_is_pdflush())
1822 return;
1823
1824 num_dirty = count_range_bits(tree, &start, (u64)-1,
1825 thresh, EXTENT_DIRTY);
1826 if (num_dirty > thresh) {
1827 balance_dirty_pages_ratelimited_nr(
1828 root->fs_info->btree_inode->i_mapping, 1);
1829 }
1830 return;
1831 }
1832
1833 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
1834 {
1835 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1836 int ret;
1837 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1838 if (ret == 0) {
1839 buf->flags |= EXTENT_UPTODATE;
1840 }
1841 return ret;
1842 }
1843
1844 static struct extent_io_ops btree_extent_io_ops = {
1845 .writepage_io_hook = btree_writepage_io_hook,
1846 .readpage_end_io_hook = btree_readpage_end_io_hook,
1847 .submit_bio_hook = btree_submit_bio_hook,
1848 /* note we're sharing with inode.c for the merge bio hook */
1849 .merge_bio_hook = btrfs_merge_bio_hook,
1850 };
Linux kernel - Deliverables
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