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