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thinkpad-acpi: documentation cleanup
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / disk-io.c
blob3e18175248e030ce37aa8dcd1edd400cb7d79e1e
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include "compat.h"
30 #include "crc32c.h"
31 #include "ctree.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "btrfs_inode.h"
35 #include "volumes.h"
36 #include "print-tree.h"
37 #include "async-thread.h"
38 #include "locking.h"
39 #include "ref-cache.h"
40 #include "tree-log.h"
41
42 static struct extent_io_ops btree_extent_io_ops;
43 static void end_workqueue_fn(struct btrfs_work *work);
44
45 /*
46 * end_io_wq structs are used to do processing in task context when an IO is
47 * complete. This is used during reads to verify checksums, and it is used
48 * by writes to insert metadata for new file extents after IO is complete.
49 */
50 struct end_io_wq {
51 struct bio *bio;
52 bio_end_io_t *end_io;
53 void *private;
54 struct btrfs_fs_info *info;
55 int error;
56 int metadata;
57 struct list_head list;
58 struct btrfs_work work;
59 };
60
61 /*
62 * async submit bios are used to offload expensive checksumming
63 * onto the worker threads. They checksum file and metadata bios
64 * just before they are sent down the IO stack.
65 */
66 struct async_submit_bio {
67 struct inode *inode;
68 struct bio *bio;
69 struct list_head list;
70 extent_submit_bio_hook_t *submit_bio_start;
71 extent_submit_bio_hook_t *submit_bio_done;
72 int rw;
73 int mirror_num;
74 unsigned long bio_flags;
75 struct btrfs_work work;
76 };
77
78 /* These are used to set the lockdep class on the extent buffer locks.
79 * The class is set by the readpage_end_io_hook after the buffer has
80 * passed csum validation but before the pages are unlocked.
81 *
82 * The lockdep class is also set by btrfs_init_new_buffer on freshly
83 * allocated blocks.
84 *
85 * The class is based on the level in the tree block, which allows lockdep
86 * to know that lower nodes nest inside the locks of higher nodes.
87 *
88 * We also add a check to make sure the highest level of the tree is
89 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
90 * code needs update as well.
91 */
92 #ifdef CONFIG_DEBUG_LOCK_ALLOC
93 # if BTRFS_MAX_LEVEL != 8
94 # error
95 # endif
96 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
97 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
98 /* leaf */
99 "btrfs-extent-00",
100 "btrfs-extent-01",
101 "btrfs-extent-02",
102 "btrfs-extent-03",
103 "btrfs-extent-04",
104 "btrfs-extent-05",
105 "btrfs-extent-06",
106 "btrfs-extent-07",
107 /* highest possible level */
108 "btrfs-extent-08",
109 };
110 #endif
111
112 /*
113 * extents on the btree inode are pretty simple, there's one extent
114 * that covers the entire device
115 */
116 static struct extent_map *btree_get_extent(struct inode *inode,
117 struct page *page, size_t page_offset, u64 start, u64 len,
118 int create)
119 {
120 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
121 struct extent_map *em;
122 int ret;
123
124 spin_lock(&em_tree->lock);
125 em = lookup_extent_mapping(em_tree, start, len);
126 if (em) {
127 em->bdev =
128 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
129 spin_unlock(&em_tree->lock);
130 goto out;
131 }
132 spin_unlock(&em_tree->lock);
133
134 em = alloc_extent_map(GFP_NOFS);
135 if (!em) {
136 em = ERR_PTR(-ENOMEM);
137 goto out;
138 }
139 em->start = 0;
140 em->len = (u64)-1;
141 em->block_len = (u64)-1;
142 em->block_start = 0;
143 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
144
145 spin_lock(&em_tree->lock);
146 ret = add_extent_mapping(em_tree, em);
147 if (ret == -EEXIST) {
148 u64 failed_start = em->start;
149 u64 failed_len = em->len;
150
151 free_extent_map(em);
152 em = lookup_extent_mapping(em_tree, start, len);
153 if (em) {
154 ret = 0;
155 } else {
156 em = lookup_extent_mapping(em_tree, failed_start,
157 failed_len);
158 ret = -EIO;
159 }
160 } else if (ret) {
161 free_extent_map(em);
162 em = NULL;
163 }
164 spin_unlock(&em_tree->lock);
165
166 if (ret)
167 em = ERR_PTR(ret);
168 out:
169 return em;
170 }
171
172 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
173 {
174 return btrfs_crc32c(seed, data, len);
175 }
176
177 void btrfs_csum_final(u32 crc, char *result)
178 {
179 *(__le32 *)result = ~cpu_to_le32(crc);
180 }
181
182 /*
183 * compute the csum for a btree block, and either verify it or write it
184 * into the csum field of the block.
185 */
186 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
187 int verify)
188 {
189 u16 csum_size =
190 btrfs_super_csum_size(&root->fs_info->super_copy);
191 char *result = NULL;
192 unsigned long len;
193 unsigned long cur_len;
194 unsigned long offset = BTRFS_CSUM_SIZE;
195 char *map_token = NULL;
196 char *kaddr;
197 unsigned long map_start;
198 unsigned long map_len;
199 int err;
200 u32 crc = ~(u32)0;
201 unsigned long inline_result;
202
203 len = buf->len - offset;
204 while (len > 0) {
205 err = map_private_extent_buffer(buf, offset, 32,
206 &map_token, &kaddr,
207 &map_start, &map_len, KM_USER0);
208 if (err)
209 return 1;
210 cur_len = min(len, map_len - (offset - map_start));
211 crc = btrfs_csum_data(root, kaddr + offset - map_start,
212 crc, cur_len);
213 len -= cur_len;
214 offset += cur_len;
215 unmap_extent_buffer(buf, map_token, KM_USER0);
216 }
217 if (csum_size > sizeof(inline_result)) {
218 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
219 if (!result)
220 return 1;
221 } else {
222 result = (char *)&inline_result;
223 }
224
225 btrfs_csum_final(crc, result);
226
227 if (verify) {
228 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
229 u32 val;
230 u32 found = 0;
231 memcpy(&found, result, csum_size);
232
233 read_extent_buffer(buf, &val, 0, csum_size);
234 printk(KERN_INFO "btrfs: %s checksum verify failed "
235 "on %llu wanted %X found %X level %d\n",
236 root->fs_info->sb->s_id,
237 buf->start, val, found, btrfs_header_level(buf));
238 if (result != (char *)&inline_result)
239 kfree(result);
240 return 1;
241 }
242 } else {
243 write_extent_buffer(buf, result, 0, csum_size);
244 }
245 if (result != (char *)&inline_result)
246 kfree(result);
247 return 0;
248 }
249
250 /*
251 * we can't consider a given block up to date unless the transid of the
252 * block matches the transid in the parent node's pointer. This is how we
253 * detect blocks that either didn't get written at all or got written
254 * in the wrong place.
255 */
256 static int verify_parent_transid(struct extent_io_tree *io_tree,
257 struct extent_buffer *eb, u64 parent_transid)
258 {
259 int ret;
260
261 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
262 return 0;
263
264 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
265 if (extent_buffer_uptodate(io_tree, eb) &&
266 btrfs_header_generation(eb) == parent_transid) {
267 ret = 0;
268 goto out;
269 }
270 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
271 (unsigned long long)eb->start,
272 (unsigned long long)parent_transid,
273 (unsigned long long)btrfs_header_generation(eb));
274 ret = 1;
275 clear_extent_buffer_uptodate(io_tree, eb);
276 out:
277 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
278 GFP_NOFS);
279 return ret;
280 }
281
282 /*
283 * helper to read a given tree block, doing retries as required when
284 * the checksums don't match and we have alternate mirrors to try.
285 */
286 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
287 struct extent_buffer *eb,
288 u64 start, u64 parent_transid)
289 {
290 struct extent_io_tree *io_tree;
291 int ret;
292 int num_copies = 0;
293 int mirror_num = 0;
294
295 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
296 while (1) {
297 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
298 btree_get_extent, mirror_num);
299 if (!ret &&
300 !verify_parent_transid(io_tree, eb, parent_transid))
301 return ret;
302
303 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
304 eb->start, eb->len);
305 if (num_copies == 1)
306 return ret;
307
308 mirror_num++;
309 if (mirror_num > num_copies)
310 return ret;
311 }
312 return -EIO;
313 }
314
315 /*
316 * checksum a dirty tree block before IO. This has extra checks to make sure
317 * we only fill in the checksum field in the first page of a multi-page block
318 */
319
320 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
321 {
322 struct extent_io_tree *tree;
323 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
324 u64 found_start;
325 int found_level;
326 unsigned long len;
327 struct extent_buffer *eb;
328 int ret;
329
330 tree = &BTRFS_I(page->mapping->host)->io_tree;
331
332 if (page->private == EXTENT_PAGE_PRIVATE)
333 goto out;
334 if (!page->private)
335 goto out;
336 len = page->private >> 2;
337 WARN_ON(len == 0);
338
339 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
340 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
341 btrfs_header_generation(eb));
342 BUG_ON(ret);
343 found_start = btrfs_header_bytenr(eb);
344 if (found_start != start) {
345 WARN_ON(1);
346 goto err;
347 }
348 if (eb->first_page != page) {
349 WARN_ON(1);
350 goto err;
351 }
352 if (!PageUptodate(page)) {
353 WARN_ON(1);
354 goto err;
355 }
356 found_level = btrfs_header_level(eb);
357
358 csum_tree_block(root, eb, 0);
359 err:
360 free_extent_buffer(eb);
361 out:
362 return 0;
363 }
364
365 static int check_tree_block_fsid(struct btrfs_root *root,
366 struct extent_buffer *eb)
367 {
368 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
369 u8 fsid[BTRFS_UUID_SIZE];
370 int ret = 1;
371
372 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
373 BTRFS_FSID_SIZE);
374 while (fs_devices) {
375 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
376 ret = 0;
377 break;
378 }
379 fs_devices = fs_devices->seed;
380 }
381 return ret;
382 }
383
384 #ifdef CONFIG_DEBUG_LOCK_ALLOC
385 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
386 {
387 lockdep_set_class_and_name(&eb->lock,
388 &btrfs_eb_class[level],
389 btrfs_eb_name[level]);
390 }
391 #endif
392
393 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
394 struct extent_state *state)
395 {
396 struct extent_io_tree *tree;
397 u64 found_start;
398 int found_level;
399 unsigned long len;
400 struct extent_buffer *eb;
401 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
402 int ret = 0;
403
404 tree = &BTRFS_I(page->mapping->host)->io_tree;
405 if (page->private == EXTENT_PAGE_PRIVATE)
406 goto out;
407 if (!page->private)
408 goto out;
409
410 len = page->private >> 2;
411 WARN_ON(len == 0);
412
413 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
414
415 found_start = btrfs_header_bytenr(eb);
416 if (found_start != start) {
417 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n",
418 (unsigned long long)found_start,
419 (unsigned long long)eb->start);
420 ret = -EIO;
421 goto err;
422 }
423 if (eb->first_page != page) {
424 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
425 eb->first_page->index, page->index);
426 WARN_ON(1);
427 ret = -EIO;
428 goto err;
429 }
430 if (check_tree_block_fsid(root, eb)) {
431 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
432 (unsigned long long)eb->start);
433 ret = -EIO;
434 goto err;
435 }
436 found_level = btrfs_header_level(eb);
437
438 btrfs_set_buffer_lockdep_class(eb, found_level);
439
440 ret = csum_tree_block(root, eb, 1);
441 if (ret)
442 ret = -EIO;
443
444 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
445 end = eb->start + end - 1;
446 err:
447 free_extent_buffer(eb);
448 out:
449 return ret;
450 }
451
452 static void end_workqueue_bio(struct bio *bio, int err)
453 {
454 struct end_io_wq *end_io_wq = bio->bi_private;
455 struct btrfs_fs_info *fs_info;
456
457 fs_info = end_io_wq->info;
458 end_io_wq->error = err;
459 end_io_wq->work.func = end_workqueue_fn;
460 end_io_wq->work.flags = 0;
461
462 if (bio->bi_rw & (1 << BIO_RW)) {
463 if (end_io_wq->metadata)
464 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
465 &end_io_wq->work);
466 else
467 btrfs_queue_worker(&fs_info->endio_write_workers,
468 &end_io_wq->work);
469 } else {
470 if (end_io_wq->metadata)
471 btrfs_queue_worker(&fs_info->endio_meta_workers,
472 &end_io_wq->work);
473 else
474 btrfs_queue_worker(&fs_info->endio_workers,
475 &end_io_wq->work);
476 }
477 }
478
479 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
480 int metadata)
481 {
482 struct end_io_wq *end_io_wq;
483 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
484 if (!end_io_wq)
485 return -ENOMEM;
486
487 end_io_wq->private = bio->bi_private;
488 end_io_wq->end_io = bio->bi_end_io;
489 end_io_wq->info = info;
490 end_io_wq->error = 0;
491 end_io_wq->bio = bio;
492 end_io_wq->metadata = metadata;
493
494 bio->bi_private = end_io_wq;
495 bio->bi_end_io = end_workqueue_bio;
496 return 0;
497 }
498
499 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
500 {
501 unsigned long limit = min_t(unsigned long,
502 info->workers.max_workers,
503 info->fs_devices->open_devices);
504 return 256 * limit;
505 }
506
507 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
508 {
509 return atomic_read(&info->nr_async_bios) >
510 btrfs_async_submit_limit(info);
511 }
512
513 static void run_one_async_start(struct btrfs_work *work)
514 {
515 struct btrfs_fs_info *fs_info;
516 struct async_submit_bio *async;
517
518 async = container_of(work, struct async_submit_bio, work);
519 fs_info = BTRFS_I(async->inode)->root->fs_info;
520 async->submit_bio_start(async->inode, async->rw, async->bio,
521 async->mirror_num, async->bio_flags);
522 }
523
524 static void run_one_async_done(struct btrfs_work *work)
525 {
526 struct btrfs_fs_info *fs_info;
527 struct async_submit_bio *async;
528 int limit;
529
530 async = container_of(work, struct async_submit_bio, work);
531 fs_info = BTRFS_I(async->inode)->root->fs_info;
532
533 limit = btrfs_async_submit_limit(fs_info);
534 limit = limit * 2 / 3;
535
536 atomic_dec(&fs_info->nr_async_submits);
537
538 if (atomic_read(&fs_info->nr_async_submits) < limit &&
539 waitqueue_active(&fs_info->async_submit_wait))
540 wake_up(&fs_info->async_submit_wait);
541
542 async->submit_bio_done(async->inode, async->rw, async->bio,
543 async->mirror_num, async->bio_flags);
544 }
545
546 static void run_one_async_free(struct btrfs_work *work)
547 {
548 struct async_submit_bio *async;
549
550 async = container_of(work, struct async_submit_bio, work);
551 kfree(async);
552 }
553
554 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
555 int rw, struct bio *bio, int mirror_num,
556 unsigned long bio_flags,
557 extent_submit_bio_hook_t *submit_bio_start,
558 extent_submit_bio_hook_t *submit_bio_done)
559 {
560 struct async_submit_bio *async;
561
562 async = kmalloc(sizeof(*async), GFP_NOFS);
563 if (!async)
564 return -ENOMEM;
565
566 async->inode = inode;
567 async->rw = rw;
568 async->bio = bio;
569 async->mirror_num = mirror_num;
570 async->submit_bio_start = submit_bio_start;
571 async->submit_bio_done = submit_bio_done;
572
573 async->work.func = run_one_async_start;
574 async->work.ordered_func = run_one_async_done;
575 async->work.ordered_free = run_one_async_free;
576
577 async->work.flags = 0;
578 async->bio_flags = bio_flags;
579
580 atomic_inc(&fs_info->nr_async_submits);
581 btrfs_queue_worker(&fs_info->workers, &async->work);
582 #if 0
583 int limit = btrfs_async_submit_limit(fs_info);
584 if (atomic_read(&fs_info->nr_async_submits) > limit) {
585 wait_event_timeout(fs_info->async_submit_wait,
586 (atomic_read(&fs_info->nr_async_submits) < limit),
587 HZ/10);
588
589 wait_event_timeout(fs_info->async_submit_wait,
590 (atomic_read(&fs_info->nr_async_bios) < limit),
591 HZ/10);
592 }
593 #endif
594 while (atomic_read(&fs_info->async_submit_draining) &&
595 atomic_read(&fs_info->nr_async_submits)) {
596 wait_event(fs_info->async_submit_wait,
597 (atomic_read(&fs_info->nr_async_submits) == 0));
598 }
599
600 return 0;
601 }
602
603 static int btree_csum_one_bio(struct bio *bio)
604 {
605 struct bio_vec *bvec = bio->bi_io_vec;
606 int bio_index = 0;
607 struct btrfs_root *root;
608
609 WARN_ON(bio->bi_vcnt <= 0);
610 while (bio_index < bio->bi_vcnt) {
611 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
612 csum_dirty_buffer(root, bvec->bv_page);
613 bio_index++;
614 bvec++;
615 }
616 return 0;
617 }
618
619 static int __btree_submit_bio_start(struct inode *inode, int rw,
620 struct bio *bio, int mirror_num,
621 unsigned long bio_flags)
622 {
623 /*
624 * when we're called for a write, we're already in the async
625 * submission context. Just jump into btrfs_map_bio
626 */
627 btree_csum_one_bio(bio);
628 return 0;
629 }
630
631 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
632 int mirror_num, unsigned long bio_flags)
633 {
634 /*
635 * when we're called for a write, we're already in the async
636 * submission context. Just jump into btrfs_map_bio
637 */
638 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
639 }
640
641 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
642 int mirror_num, unsigned long bio_flags)
643 {
644 int ret;
645
646 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
647 bio, 1);
648 BUG_ON(ret);
649
650 if (!(rw & (1 << BIO_RW))) {
651 /*
652 * called for a read, do the setup so that checksum validation
653 * can happen in the async kernel threads
654 */
655 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
656 mirror_num, 0);
657 }
658 /*
659 * kthread helpers are used to submit writes so that checksumming
660 * can happen in parallel across all CPUs
661 */
662 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
663 inode, rw, bio, mirror_num, 0,
664 __btree_submit_bio_start,
665 __btree_submit_bio_done);
666 }
667
668 static int btree_writepage(struct page *page, struct writeback_control *wbc)
669 {
670 struct extent_io_tree *tree;
671 tree = &BTRFS_I(page->mapping->host)->io_tree;
672
673 if (current->flags & PF_MEMALLOC) {
674 redirty_page_for_writepage(wbc, page);
675 unlock_page(page);
676 return 0;
677 }
678 return extent_write_full_page(tree, page, btree_get_extent, wbc);
679 }
680
681 static int btree_writepages(struct address_space *mapping,
682 struct writeback_control *wbc)
683 {
684 struct extent_io_tree *tree;
685 tree = &BTRFS_I(mapping->host)->io_tree;
686 if (wbc->sync_mode == WB_SYNC_NONE) {
687 u64 num_dirty;
688 u64 start = 0;
689 unsigned long thresh = 32 * 1024 * 1024;
690
691 if (wbc->for_kupdate)
692 return 0;
693
694 num_dirty = count_range_bits(tree, &start, (u64)-1,
695 thresh, EXTENT_DIRTY);
696 if (num_dirty < thresh)
697 return 0;
698 }
699 return extent_writepages(tree, mapping, btree_get_extent, wbc);
700 }
701
702 static int btree_readpage(struct file *file, struct page *page)
703 {
704 struct extent_io_tree *tree;
705 tree = &BTRFS_I(page->mapping->host)->io_tree;
706 return extent_read_full_page(tree, page, btree_get_extent);
707 }
708
709 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
710 {
711 struct extent_io_tree *tree;
712 struct extent_map_tree *map;
713 int ret;
714
715 if (PageWriteback(page) || PageDirty(page))
716 return 0;
717
718 tree = &BTRFS_I(page->mapping->host)->io_tree;
719 map = &BTRFS_I(page->mapping->host)->extent_tree;
720
721 ret = try_release_extent_state(map, tree, page, gfp_flags);
722 if (!ret)
723 return 0;
724
725 ret = try_release_extent_buffer(tree, page);
726 if (ret == 1) {
727 ClearPagePrivate(page);
728 set_page_private(page, 0);
729 page_cache_release(page);
730 }
731
732 return ret;
733 }
734
735 static void btree_invalidatepage(struct page *page, unsigned long offset)
736 {
737 struct extent_io_tree *tree;
738 tree = &BTRFS_I(page->mapping->host)->io_tree;
739 extent_invalidatepage(tree, page, offset);
740 btree_releasepage(page, GFP_NOFS);
741 if (PagePrivate(page)) {
742 printk(KERN_WARNING "btrfs warning page private not zero "
743 "on page %llu\n", (unsigned long long)page_offset(page));
744 ClearPagePrivate(page);
745 set_page_private(page, 0);
746 page_cache_release(page);
747 }
748 }
749
750 #if 0
751 static int btree_writepage(struct page *page, struct writeback_control *wbc)
752 {
753 struct buffer_head *bh;
754 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
755 struct buffer_head *head;
756 if (!page_has_buffers(page)) {
757 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
758 (1 << BH_Dirty)|(1 << BH_Uptodate));
759 }
760 head = page_buffers(page);
761 bh = head;
762 do {
763 if (buffer_dirty(bh))
764 csum_tree_block(root, bh, 0);
765 bh = bh->b_this_page;
766 } while (bh != head);
767 return block_write_full_page(page, btree_get_block, wbc);
768 }
769 #endif
770
771 static struct address_space_operations btree_aops = {
772 .readpage = btree_readpage,
773 .writepage = btree_writepage,
774 .writepages = btree_writepages,
775 .releasepage = btree_releasepage,
776 .invalidatepage = btree_invalidatepage,
777 .sync_page = block_sync_page,
778 };
779
780 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
781 u64 parent_transid)
782 {
783 struct extent_buffer *buf = NULL;
784 struct inode *btree_inode = root->fs_info->btree_inode;
785 int ret = 0;
786
787 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
788 if (!buf)
789 return 0;
790 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
791 buf, 0, 0, btree_get_extent, 0);
792 free_extent_buffer(buf);
793 return ret;
794 }
795
796 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
797 u64 bytenr, u32 blocksize)
798 {
799 struct inode *btree_inode = root->fs_info->btree_inode;
800 struct extent_buffer *eb;
801 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
802 bytenr, blocksize, GFP_NOFS);
803 return eb;
804 }
805
806 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
807 u64 bytenr, u32 blocksize)
808 {
809 struct inode *btree_inode = root->fs_info->btree_inode;
810 struct extent_buffer *eb;
811
812 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
813 bytenr, blocksize, NULL, GFP_NOFS);
814 return eb;
815 }
816
817
818 int btrfs_write_tree_block(struct extent_buffer *buf)
819 {
820 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
821 buf->start + buf->len - 1, WB_SYNC_ALL);
822 }
823
824 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
825 {
826 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
827 buf->start, buf->start + buf->len - 1);
828 }
829
830 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
831 u32 blocksize, u64 parent_transid)
832 {
833 struct extent_buffer *buf = NULL;
834 struct inode *btree_inode = root->fs_info->btree_inode;
835 struct extent_io_tree *io_tree;
836 int ret;
837
838 io_tree = &BTRFS_I(btree_inode)->io_tree;
839
840 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
841 if (!buf)
842 return NULL;
843
844 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
845
846 if (ret == 0)
847 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
848 else
849 WARN_ON(1);
850 return buf;
851
852 }
853
854 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
855 struct extent_buffer *buf)
856 {
857 struct inode *btree_inode = root->fs_info->btree_inode;
858 if (btrfs_header_generation(buf) ==
859 root->fs_info->running_transaction->transid) {
860 btrfs_assert_tree_locked(buf);
861
862 /* ugh, clear_extent_buffer_dirty can be expensive */
863 btrfs_set_lock_blocking(buf);
864
865 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
866 buf);
867 }
868 return 0;
869 }
870
871 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
872 u32 stripesize, struct btrfs_root *root,
873 struct btrfs_fs_info *fs_info,
874 u64 objectid)
875 {
876 root->node = NULL;
877 root->commit_root = NULL;
878 root->ref_tree = NULL;
879 root->sectorsize = sectorsize;
880 root->nodesize = nodesize;
881 root->leafsize = leafsize;
882 root->stripesize = stripesize;
883 root->ref_cows = 0;
884 root->track_dirty = 0;
885
886 root->fs_info = fs_info;
887 root->objectid = objectid;
888 root->last_trans = 0;
889 root->highest_inode = 0;
890 root->last_inode_alloc = 0;
891 root->name = NULL;
892 root->in_sysfs = 0;
893
894 INIT_LIST_HEAD(&root->dirty_list);
895 INIT_LIST_HEAD(&root->orphan_list);
896 INIT_LIST_HEAD(&root->dead_list);
897 spin_lock_init(&root->node_lock);
898 spin_lock_init(&root->list_lock);
899 mutex_init(&root->objectid_mutex);
900 mutex_init(&root->log_mutex);
901 init_waitqueue_head(&root->log_writer_wait);
902 init_waitqueue_head(&root->log_commit_wait[0]);
903 init_waitqueue_head(&root->log_commit_wait[1]);
904 atomic_set(&root->log_commit[0], 0);
905 atomic_set(&root->log_commit[1], 0);
906 atomic_set(&root->log_writers, 0);
907 root->log_batch = 0;
908 root->log_transid = 0;
909 extent_io_tree_init(&root->dirty_log_pages,
910 fs_info->btree_inode->i_mapping, GFP_NOFS);
911
912 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
913 root->ref_tree = &root->ref_tree_struct;
914
915 memset(&root->root_key, 0, sizeof(root->root_key));
916 memset(&root->root_item, 0, sizeof(root->root_item));
917 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
918 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
919 root->defrag_trans_start = fs_info->generation;
920 init_completion(&root->kobj_unregister);
921 root->defrag_running = 0;
922 root->defrag_level = 0;
923 root->root_key.objectid = objectid;
924 root->anon_super.s_root = NULL;
925 root->anon_super.s_dev = 0;
926 INIT_LIST_HEAD(&root->anon_super.s_list);
927 INIT_LIST_HEAD(&root->anon_super.s_instances);
928 init_rwsem(&root->anon_super.s_umount);
929
930 return 0;
931 }
932
933 static int find_and_setup_root(struct btrfs_root *tree_root,
934 struct btrfs_fs_info *fs_info,
935 u64 objectid,
936 struct btrfs_root *root)
937 {
938 int ret;
939 u32 blocksize;
940 u64 generation;
941
942 __setup_root(tree_root->nodesize, tree_root->leafsize,
943 tree_root->sectorsize, tree_root->stripesize,
944 root, fs_info, objectid);
945 ret = btrfs_find_last_root(tree_root, objectid,
946 &root->root_item, &root->root_key);
947 BUG_ON(ret);
948
949 generation = btrfs_root_generation(&root->root_item);
950 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
951 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
952 blocksize, generation);
953 BUG_ON(!root->node);
954 return 0;
955 }
956
957 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
958 struct btrfs_fs_info *fs_info)
959 {
960 struct extent_buffer *eb;
961 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
962 u64 start = 0;
963 u64 end = 0;
964 int ret;
965
966 if (!log_root_tree)
967 return 0;
968
969 while (1) {
970 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
971 0, &start, &end, EXTENT_DIRTY);
972 if (ret)
973 break;
974
975 clear_extent_dirty(&log_root_tree->dirty_log_pages,
976 start, end, GFP_NOFS);
977 }
978 eb = fs_info->log_root_tree->node;
979
980 WARN_ON(btrfs_header_level(eb) != 0);
981 WARN_ON(btrfs_header_nritems(eb) != 0);
982
983 ret = btrfs_free_reserved_extent(fs_info->tree_root,
984 eb->start, eb->len);
985 BUG_ON(ret);
986
987 free_extent_buffer(eb);
988 kfree(fs_info->log_root_tree);
989 fs_info->log_root_tree = NULL;
990 return 0;
991 }
992
993 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
994 struct btrfs_fs_info *fs_info)
995 {
996 struct btrfs_root *root;
997 struct btrfs_root *tree_root = fs_info->tree_root;
998 struct extent_buffer *leaf;
999
1000 root = kzalloc(sizeof(*root), GFP_NOFS);
1001 if (!root)
1002 return ERR_PTR(-ENOMEM);
1003
1004 __setup_root(tree_root->nodesize, tree_root->leafsize,
1005 tree_root->sectorsize, tree_root->stripesize,
1006 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1007
1008 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1009 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1010 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1011 /*
1012 * log trees do not get reference counted because they go away
1013 * before a real commit is actually done. They do store pointers
1014 * to file data extents, and those reference counts still get
1015 * updated (along with back refs to the log tree).
1016 */
1017 root->ref_cows = 0;
1018
1019 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1020 0, BTRFS_TREE_LOG_OBJECTID,
1021 trans->transid, 0, 0, 0);
1022 if (IS_ERR(leaf)) {
1023 kfree(root);
1024 return ERR_CAST(leaf);
1025 }
1026
1027 root->node = leaf;
1028 btrfs_set_header_nritems(root->node, 0);
1029 btrfs_set_header_level(root->node, 0);
1030 btrfs_set_header_bytenr(root->node, root->node->start);
1031 btrfs_set_header_generation(root->node, trans->transid);
1032 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
1033
1034 write_extent_buffer(root->node, root->fs_info->fsid,
1035 (unsigned long)btrfs_header_fsid(root->node),
1036 BTRFS_FSID_SIZE);
1037 btrfs_mark_buffer_dirty(root->node);
1038 btrfs_tree_unlock(root->node);
1039 return root;
1040 }
1041
1042 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1043 struct btrfs_fs_info *fs_info)
1044 {
1045 struct btrfs_root *log_root;
1046
1047 log_root = alloc_log_tree(trans, fs_info);
1048 if (IS_ERR(log_root))
1049 return PTR_ERR(log_root);
1050 WARN_ON(fs_info->log_root_tree);
1051 fs_info->log_root_tree = log_root;
1052 return 0;
1053 }
1054
1055 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1056 struct btrfs_root *root)
1057 {
1058 struct btrfs_root *log_root;
1059 struct btrfs_inode_item *inode_item;
1060
1061 log_root = alloc_log_tree(trans, root->fs_info);
1062 if (IS_ERR(log_root))
1063 return PTR_ERR(log_root);
1064
1065 log_root->last_trans = trans->transid;
1066 log_root->root_key.offset = root->root_key.objectid;
1067
1068 inode_item = &log_root->root_item.inode;
1069 inode_item->generation = cpu_to_le64(1);
1070 inode_item->size = cpu_to_le64(3);
1071 inode_item->nlink = cpu_to_le32(1);
1072 inode_item->nbytes = cpu_to_le64(root->leafsize);
1073 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1074
1075 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1076 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1077
1078 WARN_ON(root->log_root);
1079 root->log_root = log_root;
1080 root->log_transid = 0;
1081 return 0;
1082 }
1083
1084 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1085 struct btrfs_key *location)
1086 {
1087 struct btrfs_root *root;
1088 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1089 struct btrfs_path *path;
1090 struct extent_buffer *l;
1091 u64 highest_inode;
1092 u64 generation;
1093 u32 blocksize;
1094 int ret = 0;
1095
1096 root = kzalloc(sizeof(*root), GFP_NOFS);
1097 if (!root)
1098 return ERR_PTR(-ENOMEM);
1099 if (location->offset == (u64)-1) {
1100 ret = find_and_setup_root(tree_root, fs_info,
1101 location->objectid, root);
1102 if (ret) {
1103 kfree(root);
1104 return ERR_PTR(ret);
1105 }
1106 goto insert;
1107 }
1108
1109 __setup_root(tree_root->nodesize, tree_root->leafsize,
1110 tree_root->sectorsize, tree_root->stripesize,
1111 root, fs_info, location->objectid);
1112
1113 path = btrfs_alloc_path();
1114 BUG_ON(!path);
1115 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1116 if (ret != 0) {
1117 if (ret > 0)
1118 ret = -ENOENT;
1119 goto out;
1120 }
1121 l = path->nodes[0];
1122 read_extent_buffer(l, &root->root_item,
1123 btrfs_item_ptr_offset(l, path->slots[0]),
1124 sizeof(root->root_item));
1125 memcpy(&root->root_key, location, sizeof(*location));
1126 ret = 0;
1127 out:
1128 btrfs_release_path(root, path);
1129 btrfs_free_path(path);
1130 if (ret) {
1131 kfree(root);
1132 return ERR_PTR(ret);
1133 }
1134 generation = btrfs_root_generation(&root->root_item);
1135 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1136 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1137 blocksize, generation);
1138 BUG_ON(!root->node);
1139 insert:
1140 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1141 root->ref_cows = 1;
1142 ret = btrfs_find_highest_inode(root, &highest_inode);
1143 if (ret == 0) {
1144 root->highest_inode = highest_inode;
1145 root->last_inode_alloc = highest_inode;
1146 }
1147 }
1148 return root;
1149 }
1150
1151 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1152 u64 root_objectid)
1153 {
1154 struct btrfs_root *root;
1155
1156 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1157 return fs_info->tree_root;
1158 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1159 return fs_info->extent_root;
1160
1161 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1162 (unsigned long)root_objectid);
1163 return root;
1164 }
1165
1166 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1167 struct btrfs_key *location)
1168 {
1169 struct btrfs_root *root;
1170 int ret;
1171
1172 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1173 return fs_info->tree_root;
1174 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1175 return fs_info->extent_root;
1176 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1177 return fs_info->chunk_root;
1178 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1179 return fs_info->dev_root;
1180 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1181 return fs_info->csum_root;
1182
1183 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1184 (unsigned long)location->objectid);
1185 if (root)
1186 return root;
1187
1188 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1189 if (IS_ERR(root))
1190 return root;
1191
1192 set_anon_super(&root->anon_super, NULL);
1193
1194 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1195 (unsigned long)root->root_key.objectid,
1196 root);
1197 if (ret) {
1198 free_extent_buffer(root->node);
1199 kfree(root);
1200 return ERR_PTR(ret);
1201 }
1202 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1203 ret = btrfs_find_dead_roots(fs_info->tree_root,
1204 root->root_key.objectid, root);
1205 BUG_ON(ret);
1206 btrfs_orphan_cleanup(root);
1207 }
1208 return root;
1209 }
1210
1211 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1212 struct btrfs_key *location,
1213 const char *name, int namelen)
1214 {
1215 struct btrfs_root *root;
1216 int ret;
1217
1218 root = btrfs_read_fs_root_no_name(fs_info, location);
1219 if (!root)
1220 return NULL;
1221
1222 if (root->in_sysfs)
1223 return root;
1224
1225 ret = btrfs_set_root_name(root, name, namelen);
1226 if (ret) {
1227 free_extent_buffer(root->node);
1228 kfree(root);
1229 return ERR_PTR(ret);
1230 }
1231 #if 0
1232 ret = btrfs_sysfs_add_root(root);
1233 if (ret) {
1234 free_extent_buffer(root->node);
1235 kfree(root->name);
1236 kfree(root);
1237 return ERR_PTR(ret);
1238 }
1239 #endif
1240 root->in_sysfs = 1;
1241 return root;
1242 }
1243
1244 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1245 {
1246 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1247 int ret = 0;
1248 struct btrfs_device *device;
1249 struct backing_dev_info *bdi;
1250 #if 0
1251 if ((bdi_bits & (1 << BDI_write_congested)) &&
1252 btrfs_congested_async(info, 0))
1253 return 1;
1254 #endif
1255 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1256 if (!device->bdev)
1257 continue;
1258 bdi = blk_get_backing_dev_info(device->bdev);
1259 if (bdi && bdi_congested(bdi, bdi_bits)) {
1260 ret = 1;
1261 break;
1262 }
1263 }
1264 return ret;
1265 }
1266
1267 /*
1268 * this unplugs every device on the box, and it is only used when page
1269 * is null
1270 */
1271 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1272 {
1273 struct btrfs_device *device;
1274 struct btrfs_fs_info *info;
1275
1276 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1277 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1278 if (!device->bdev)
1279 continue;
1280
1281 bdi = blk_get_backing_dev_info(device->bdev);
1282 if (bdi->unplug_io_fn)
1283 bdi->unplug_io_fn(bdi, page);
1284 }
1285 }
1286
1287 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1288 {
1289 struct inode *inode;
1290 struct extent_map_tree *em_tree;
1291 struct extent_map *em;
1292 struct address_space *mapping;
1293 u64 offset;
1294
1295 /* the generic O_DIRECT read code does this */
1296 if (1 || !page) {
1297 __unplug_io_fn(bdi, page);
1298 return;
1299 }
1300
1301 /*
1302 * page->mapping may change at any time. Get a consistent copy
1303 * and use that for everything below
1304 */
1305 smp_mb();
1306 mapping = page->mapping;
1307 if (!mapping)
1308 return;
1309
1310 inode = mapping->host;
1311
1312 /*
1313 * don't do the expensive searching for a small number of
1314 * devices
1315 */
1316 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1317 __unplug_io_fn(bdi, page);
1318 return;
1319 }
1320
1321 offset = page_offset(page);
1322
1323 em_tree = &BTRFS_I(inode)->extent_tree;
1324 spin_lock(&em_tree->lock);
1325 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1326 spin_unlock(&em_tree->lock);
1327 if (!em) {
1328 __unplug_io_fn(bdi, page);
1329 return;
1330 }
1331
1332 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1333 free_extent_map(em);
1334 __unplug_io_fn(bdi, page);
1335 return;
1336 }
1337 offset = offset - em->start;
1338 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1339 em->block_start + offset, page);
1340 free_extent_map(em);
1341 }
1342
1343 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1344 {
1345 bdi_init(bdi);
1346 bdi->ra_pages = default_backing_dev_info.ra_pages;
1347 bdi->state = 0;
1348 bdi->capabilities = default_backing_dev_info.capabilities;
1349 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1350 bdi->unplug_io_data = info;
1351 bdi->congested_fn = btrfs_congested_fn;
1352 bdi->congested_data = info;
1353 return 0;
1354 }
1355
1356 static int bio_ready_for_csum(struct bio *bio)
1357 {
1358 u64 length = 0;
1359 u64 buf_len = 0;
1360 u64 start = 0;
1361 struct page *page;
1362 struct extent_io_tree *io_tree = NULL;
1363 struct btrfs_fs_info *info = NULL;
1364 struct bio_vec *bvec;
1365 int i;
1366 int ret;
1367
1368 bio_for_each_segment(bvec, bio, i) {
1369 page = bvec->bv_page;
1370 if (page->private == EXTENT_PAGE_PRIVATE) {
1371 length += bvec->bv_len;
1372 continue;
1373 }
1374 if (!page->private) {
1375 length += bvec->bv_len;
1376 continue;
1377 }
1378 length = bvec->bv_len;
1379 buf_len = page->private >> 2;
1380 start = page_offset(page) + bvec->bv_offset;
1381 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1382 info = BTRFS_I(page->mapping->host)->root->fs_info;
1383 }
1384 /* are we fully contained in this bio? */
1385 if (buf_len <= length)
1386 return 1;
1387
1388 ret = extent_range_uptodate(io_tree, start + length,
1389 start + buf_len - 1);
1390 if (ret == 1)
1391 return ret;
1392 return ret;
1393 }
1394
1395 /*
1396 * called by the kthread helper functions to finally call the bio end_io
1397 * functions. This is where read checksum verification actually happens
1398 */
1399 static void end_workqueue_fn(struct btrfs_work *work)
1400 {
1401 struct bio *bio;
1402 struct end_io_wq *end_io_wq;
1403 struct btrfs_fs_info *fs_info;
1404 int error;
1405
1406 end_io_wq = container_of(work, struct end_io_wq, work);
1407 bio = end_io_wq->bio;
1408 fs_info = end_io_wq->info;
1409
1410 /* metadata bio reads are special because the whole tree block must
1411 * be checksummed at once. This makes sure the entire block is in
1412 * ram and up to date before trying to verify things. For
1413 * blocksize <= pagesize, it is basically a noop
1414 */
1415 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1416 !bio_ready_for_csum(bio)) {
1417 btrfs_queue_worker(&fs_info->endio_meta_workers,
1418 &end_io_wq->work);
1419 return;
1420 }
1421 error = end_io_wq->error;
1422 bio->bi_private = end_io_wq->private;
1423 bio->bi_end_io = end_io_wq->end_io;
1424 kfree(end_io_wq);
1425 bio_endio(bio, error);
1426 }
1427
1428 static int cleaner_kthread(void *arg)
1429 {
1430 struct btrfs_root *root = arg;
1431
1432 do {
1433 smp_mb();
1434 if (root->fs_info->closing)
1435 break;
1436
1437 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1438 mutex_lock(&root->fs_info->cleaner_mutex);
1439 btrfs_clean_old_snapshots(root);
1440 mutex_unlock(&root->fs_info->cleaner_mutex);
1441
1442 if (freezing(current)) {
1443 refrigerator();
1444 } else {
1445 smp_mb();
1446 if (root->fs_info->closing)
1447 break;
1448 set_current_state(TASK_INTERRUPTIBLE);
1449 schedule();
1450 __set_current_state(TASK_RUNNING);
1451 }
1452 } while (!kthread_should_stop());
1453 return 0;
1454 }
1455
1456 static int transaction_kthread(void *arg)
1457 {
1458 struct btrfs_root *root = arg;
1459 struct btrfs_trans_handle *trans;
1460 struct btrfs_transaction *cur;
1461 unsigned long now;
1462 unsigned long delay;
1463 int ret;
1464
1465 do {
1466 smp_mb();
1467 if (root->fs_info->closing)
1468 break;
1469
1470 delay = HZ * 30;
1471 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1472 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1473
1474 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1475 printk(KERN_INFO "btrfs: total reference cache "
1476 "size %llu\n",
1477 root->fs_info->total_ref_cache_size);
1478 }
1479
1480 mutex_lock(&root->fs_info->trans_mutex);
1481 cur = root->fs_info->running_transaction;
1482 if (!cur) {
1483 mutex_unlock(&root->fs_info->trans_mutex);
1484 goto sleep;
1485 }
1486
1487 now = get_seconds();
1488 if (now < cur->start_time || now - cur->start_time < 30) {
1489 mutex_unlock(&root->fs_info->trans_mutex);
1490 delay = HZ * 5;
1491 goto sleep;
1492 }
1493 mutex_unlock(&root->fs_info->trans_mutex);
1494 trans = btrfs_start_transaction(root, 1);
1495 ret = btrfs_commit_transaction(trans, root);
1496 sleep:
1497 wake_up_process(root->fs_info->cleaner_kthread);
1498 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1499
1500 if (freezing(current)) {
1501 refrigerator();
1502 } else {
1503 if (root->fs_info->closing)
1504 break;
1505 set_current_state(TASK_INTERRUPTIBLE);
1506 schedule_timeout(delay);
1507 __set_current_state(TASK_RUNNING);
1508 }
1509 } while (!kthread_should_stop());
1510 return 0;
1511 }
1512
1513 struct btrfs_root *open_ctree(struct super_block *sb,
1514 struct btrfs_fs_devices *fs_devices,
1515 char *options)
1516 {
1517 u32 sectorsize;
1518 u32 nodesize;
1519 u32 leafsize;
1520 u32 blocksize;
1521 u32 stripesize;
1522 u64 generation;
1523 u64 features;
1524 struct btrfs_key location;
1525 struct buffer_head *bh;
1526 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1527 GFP_NOFS);
1528 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1529 GFP_NOFS);
1530 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1531 GFP_NOFS);
1532 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1533 GFP_NOFS);
1534 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1535 GFP_NOFS);
1536 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1537 GFP_NOFS);
1538 struct btrfs_root *log_tree_root;
1539
1540 int ret;
1541 int err = -EINVAL;
1542
1543 struct btrfs_super_block *disk_super;
1544
1545 if (!extent_root || !tree_root || !fs_info ||
1546 !chunk_root || !dev_root || !csum_root) {
1547 err = -ENOMEM;
1548 goto fail;
1549 }
1550 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1551 INIT_LIST_HEAD(&fs_info->trans_list);
1552 INIT_LIST_HEAD(&fs_info->dead_roots);
1553 INIT_LIST_HEAD(&fs_info->hashers);
1554 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1555 spin_lock_init(&fs_info->delalloc_lock);
1556 spin_lock_init(&fs_info->new_trans_lock);
1557 spin_lock_init(&fs_info->ref_cache_lock);
1558
1559 init_completion(&fs_info->kobj_unregister);
1560 fs_info->tree_root = tree_root;
1561 fs_info->extent_root = extent_root;
1562 fs_info->csum_root = csum_root;
1563 fs_info->chunk_root = chunk_root;
1564 fs_info->dev_root = dev_root;
1565 fs_info->fs_devices = fs_devices;
1566 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1567 INIT_LIST_HEAD(&fs_info->space_info);
1568 btrfs_mapping_init(&fs_info->mapping_tree);
1569 atomic_set(&fs_info->nr_async_submits, 0);
1570 atomic_set(&fs_info->async_delalloc_pages, 0);
1571 atomic_set(&fs_info->async_submit_draining, 0);
1572 atomic_set(&fs_info->nr_async_bios, 0);
1573 atomic_set(&fs_info->throttles, 0);
1574 atomic_set(&fs_info->throttle_gen, 0);
1575 fs_info->sb = sb;
1576 fs_info->max_extent = (u64)-1;
1577 fs_info->max_inline = 8192 * 1024;
1578 setup_bdi(fs_info, &fs_info->bdi);
1579 fs_info->btree_inode = new_inode(sb);
1580 fs_info->btree_inode->i_ino = 1;
1581 fs_info->btree_inode->i_nlink = 1;
1582
1583 fs_info->thread_pool_size = min_t(unsigned long,
1584 num_online_cpus() + 2, 8);
1585
1586 INIT_LIST_HEAD(&fs_info->ordered_extents);
1587 spin_lock_init(&fs_info->ordered_extent_lock);
1588
1589 sb->s_blocksize = 4096;
1590 sb->s_blocksize_bits = blksize_bits(4096);
1591
1592 /*
1593 * we set the i_size on the btree inode to the max possible int.
1594 * the real end of the address space is determined by all of
1595 * the devices in the system
1596 */
1597 fs_info->btree_inode->i_size = OFFSET_MAX;
1598 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1599 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1600
1601 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1602 fs_info->btree_inode->i_mapping,
1603 GFP_NOFS);
1604 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1605 GFP_NOFS);
1606
1607 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1608
1609 spin_lock_init(&fs_info->block_group_cache_lock);
1610 fs_info->block_group_cache_tree.rb_node = NULL;
1611
1612 extent_io_tree_init(&fs_info->pinned_extents,
1613 fs_info->btree_inode->i_mapping, GFP_NOFS);
1614 extent_io_tree_init(&fs_info->pending_del,
1615 fs_info->btree_inode->i_mapping, GFP_NOFS);
1616 extent_io_tree_init(&fs_info->extent_ins,
1617 fs_info->btree_inode->i_mapping, GFP_NOFS);
1618 fs_info->do_barriers = 1;
1619
1620 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1621 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1622 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1623
1624 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1625 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1626 sizeof(struct btrfs_key));
1627 insert_inode_hash(fs_info->btree_inode);
1628
1629 mutex_init(&fs_info->trans_mutex);
1630 mutex_init(&fs_info->tree_log_mutex);
1631 mutex_init(&fs_info->drop_mutex);
1632 mutex_init(&fs_info->extent_ins_mutex);
1633 mutex_init(&fs_info->pinned_mutex);
1634 mutex_init(&fs_info->chunk_mutex);
1635 mutex_init(&fs_info->transaction_kthread_mutex);
1636 mutex_init(&fs_info->cleaner_mutex);
1637 mutex_init(&fs_info->volume_mutex);
1638 mutex_init(&fs_info->tree_reloc_mutex);
1639 init_waitqueue_head(&fs_info->transaction_throttle);
1640 init_waitqueue_head(&fs_info->transaction_wait);
1641 init_waitqueue_head(&fs_info->async_submit_wait);
1642
1643 __setup_root(4096, 4096, 4096, 4096, tree_root,
1644 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1645
1646
1647 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1648 if (!bh)
1649 goto fail_iput;
1650
1651 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1652 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1653 sizeof(fs_info->super_for_commit));
1654 brelse(bh);
1655
1656 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1657
1658 disk_super = &fs_info->super_copy;
1659 if (!btrfs_super_root(disk_super))
1660 goto fail_iput;
1661
1662 ret = btrfs_parse_options(tree_root, options);
1663 if (ret) {
1664 err = ret;
1665 goto fail_iput;
1666 }
1667
1668 features = btrfs_super_incompat_flags(disk_super) &
1669 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1670 if (features) {
1671 printk(KERN_ERR "BTRFS: couldn't mount because of "
1672 "unsupported optional features (%Lx).\n",
1673 features);
1674 err = -EINVAL;
1675 goto fail_iput;
1676 }
1677
1678 features = btrfs_super_compat_ro_flags(disk_super) &
1679 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1680 if (!(sb->s_flags & MS_RDONLY) && features) {
1681 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1682 "unsupported option features (%Lx).\n",
1683 features);
1684 err = -EINVAL;
1685 goto fail_iput;
1686 }
1687
1688 /*
1689 * we need to start all the end_io workers up front because the
1690 * queue work function gets called at interrupt time, and so it
1691 * cannot dynamically grow.
1692 */
1693 btrfs_init_workers(&fs_info->workers, "worker",
1694 fs_info->thread_pool_size);
1695
1696 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1697 fs_info->thread_pool_size);
1698
1699 btrfs_init_workers(&fs_info->submit_workers, "submit",
1700 min_t(u64, fs_devices->num_devices,
1701 fs_info->thread_pool_size));
1702
1703 /* a higher idle thresh on the submit workers makes it much more
1704 * likely that bios will be send down in a sane order to the
1705 * devices
1706 */
1707 fs_info->submit_workers.idle_thresh = 64;
1708
1709 fs_info->workers.idle_thresh = 16;
1710 fs_info->workers.ordered = 1;
1711
1712 fs_info->delalloc_workers.idle_thresh = 2;
1713 fs_info->delalloc_workers.ordered = 1;
1714
1715 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1716 btrfs_init_workers(&fs_info->endio_workers, "endio",
1717 fs_info->thread_pool_size);
1718 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1719 fs_info->thread_pool_size);
1720 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1721 "endio-meta-write", fs_info->thread_pool_size);
1722 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1723 fs_info->thread_pool_size);
1724
1725 /*
1726 * endios are largely parallel and should have a very
1727 * low idle thresh
1728 */
1729 fs_info->endio_workers.idle_thresh = 4;
1730 fs_info->endio_meta_workers.idle_thresh = 4;
1731
1732 fs_info->endio_write_workers.idle_thresh = 64;
1733 fs_info->endio_meta_write_workers.idle_thresh = 64;
1734
1735 btrfs_start_workers(&fs_info->workers, 1);
1736 btrfs_start_workers(&fs_info->submit_workers, 1);
1737 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1738 btrfs_start_workers(&fs_info->fixup_workers, 1);
1739 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1740 btrfs_start_workers(&fs_info->endio_meta_workers,
1741 fs_info->thread_pool_size);
1742 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1743 fs_info->thread_pool_size);
1744 btrfs_start_workers(&fs_info->endio_write_workers,
1745 fs_info->thread_pool_size);
1746
1747 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1748 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1749 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1750
1751 nodesize = btrfs_super_nodesize(disk_super);
1752 leafsize = btrfs_super_leafsize(disk_super);
1753 sectorsize = btrfs_super_sectorsize(disk_super);
1754 stripesize = btrfs_super_stripesize(disk_super);
1755 tree_root->nodesize = nodesize;
1756 tree_root->leafsize = leafsize;
1757 tree_root->sectorsize = sectorsize;
1758 tree_root->stripesize = stripesize;
1759
1760 sb->s_blocksize = sectorsize;
1761 sb->s_blocksize_bits = blksize_bits(sectorsize);
1762
1763 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1764 sizeof(disk_super->magic))) {
1765 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1766 goto fail_sb_buffer;
1767 }
1768
1769 mutex_lock(&fs_info->chunk_mutex);
1770 ret = btrfs_read_sys_array(tree_root);
1771 mutex_unlock(&fs_info->chunk_mutex);
1772 if (ret) {
1773 printk(KERN_WARNING "btrfs: failed to read the system "
1774 "array on %s\n", sb->s_id);
1775 goto fail_sys_array;
1776 }
1777
1778 blocksize = btrfs_level_size(tree_root,
1779 btrfs_super_chunk_root_level(disk_super));
1780 generation = btrfs_super_chunk_root_generation(disk_super);
1781
1782 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1783 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1784
1785 chunk_root->node = read_tree_block(chunk_root,
1786 btrfs_super_chunk_root(disk_super),
1787 blocksize, generation);
1788 BUG_ON(!chunk_root->node);
1789
1790 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1791 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1792 BTRFS_UUID_SIZE);
1793
1794 mutex_lock(&fs_info->chunk_mutex);
1795 ret = btrfs_read_chunk_tree(chunk_root);
1796 mutex_unlock(&fs_info->chunk_mutex);
1797 if (ret) {
1798 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1799 sb->s_id);
1800 goto fail_chunk_root;
1801 }
1802
1803 btrfs_close_extra_devices(fs_devices);
1804
1805 blocksize = btrfs_level_size(tree_root,
1806 btrfs_super_root_level(disk_super));
1807 generation = btrfs_super_generation(disk_super);
1808
1809 tree_root->node = read_tree_block(tree_root,
1810 btrfs_super_root(disk_super),
1811 blocksize, generation);
1812 if (!tree_root->node)
1813 goto fail_chunk_root;
1814
1815
1816 ret = find_and_setup_root(tree_root, fs_info,
1817 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1818 if (ret)
1819 goto fail_tree_root;
1820 extent_root->track_dirty = 1;
1821
1822 ret = find_and_setup_root(tree_root, fs_info,
1823 BTRFS_DEV_TREE_OBJECTID, dev_root);
1824 dev_root->track_dirty = 1;
1825 if (ret)
1826 goto fail_extent_root;
1827
1828 ret = find_and_setup_root(tree_root, fs_info,
1829 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1830 if (ret)
1831 goto fail_extent_root;
1832
1833 csum_root->track_dirty = 1;
1834
1835 btrfs_read_block_groups(extent_root);
1836
1837 fs_info->generation = generation;
1838 fs_info->last_trans_committed = generation;
1839 fs_info->data_alloc_profile = (u64)-1;
1840 fs_info->metadata_alloc_profile = (u64)-1;
1841 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1842 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1843 "btrfs-cleaner");
1844 if (IS_ERR(fs_info->cleaner_kthread))
1845 goto fail_csum_root;
1846
1847 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1848 tree_root,
1849 "btrfs-transaction");
1850 if (IS_ERR(fs_info->transaction_kthread))
1851 goto fail_cleaner;
1852
1853 if (btrfs_super_log_root(disk_super) != 0) {
1854 u64 bytenr = btrfs_super_log_root(disk_super);
1855
1856 if (fs_devices->rw_devices == 0) {
1857 printk(KERN_WARNING "Btrfs log replay required "
1858 "on RO media\n");
1859 err = -EIO;
1860 goto fail_trans_kthread;
1861 }
1862 blocksize =
1863 btrfs_level_size(tree_root,
1864 btrfs_super_log_root_level(disk_super));
1865
1866 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1867 GFP_NOFS);
1868
1869 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1870 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1871
1872 log_tree_root->node = read_tree_block(tree_root, bytenr,
1873 blocksize,
1874 generation + 1);
1875 ret = btrfs_recover_log_trees(log_tree_root);
1876 BUG_ON(ret);
1877
1878 if (sb->s_flags & MS_RDONLY) {
1879 ret = btrfs_commit_super(tree_root);
1880 BUG_ON(ret);
1881 }
1882 }
1883
1884 if (!(sb->s_flags & MS_RDONLY)) {
1885 ret = btrfs_cleanup_reloc_trees(tree_root);
1886 BUG_ON(ret);
1887 }
1888
1889 location.objectid = BTRFS_FS_TREE_OBJECTID;
1890 location.type = BTRFS_ROOT_ITEM_KEY;
1891 location.offset = (u64)-1;
1892
1893 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1894 if (!fs_info->fs_root)
1895 goto fail_trans_kthread;
1896 return tree_root;
1897
1898 fail_trans_kthread:
1899 kthread_stop(fs_info->transaction_kthread);
1900 fail_cleaner:
1901 kthread_stop(fs_info->cleaner_kthread);
1902
1903 /*
1904 * make sure we're done with the btree inode before we stop our
1905 * kthreads
1906 */
1907 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1908 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1909
1910 fail_csum_root:
1911 free_extent_buffer(csum_root->node);
1912 fail_extent_root:
1913 free_extent_buffer(extent_root->node);
1914 fail_tree_root:
1915 free_extent_buffer(tree_root->node);
1916 fail_chunk_root:
1917 free_extent_buffer(chunk_root->node);
1918 fail_sys_array:
1919 free_extent_buffer(dev_root->node);
1920 fail_sb_buffer:
1921 btrfs_stop_workers(&fs_info->fixup_workers);
1922 btrfs_stop_workers(&fs_info->delalloc_workers);
1923 btrfs_stop_workers(&fs_info->workers);
1924 btrfs_stop_workers(&fs_info->endio_workers);
1925 btrfs_stop_workers(&fs_info->endio_meta_workers);
1926 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1927 btrfs_stop_workers(&fs_info->endio_write_workers);
1928 btrfs_stop_workers(&fs_info->submit_workers);
1929 fail_iput:
1930 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1931 iput(fs_info->btree_inode);
1932
1933 btrfs_close_devices(fs_info->fs_devices);
1934 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1935 bdi_destroy(&fs_info->bdi);
1936
1937 fail:
1938 kfree(extent_root);
1939 kfree(tree_root);
1940 kfree(fs_info);
1941 kfree(chunk_root);
1942 kfree(dev_root);
1943 kfree(csum_root);
1944 return ERR_PTR(err);
1945 }
1946
1947 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1948 {
1949 char b[BDEVNAME_SIZE];
1950
1951 if (uptodate) {
1952 set_buffer_uptodate(bh);
1953 } else {
1954 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1955 printk(KERN_WARNING "lost page write due to "
1956 "I/O error on %s\n",
1957 bdevname(bh->b_bdev, b));
1958 }
1959 /* note, we dont' set_buffer_write_io_error because we have
1960 * our own ways of dealing with the IO errors
1961 */
1962 clear_buffer_uptodate(bh);
1963 }
1964 unlock_buffer(bh);
1965 put_bh(bh);
1966 }
1967
1968 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1969 {
1970 struct buffer_head *bh;
1971 struct buffer_head *latest = NULL;
1972 struct btrfs_super_block *super;
1973 int i;
1974 u64 transid = 0;
1975 u64 bytenr;
1976
1977 /* we would like to check all the supers, but that would make
1978 * a btrfs mount succeed after a mkfs from a different FS.
1979 * So, we need to add a special mount option to scan for
1980 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1981 */
1982 for (i = 0; i < 1; i++) {
1983 bytenr = btrfs_sb_offset(i);
1984 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
1985 break;
1986 bh = __bread(bdev, bytenr / 4096, 4096);
1987 if (!bh)
1988 continue;
1989
1990 super = (struct btrfs_super_block *)bh->b_data;
1991 if (btrfs_super_bytenr(super) != bytenr ||
1992 strncmp((char *)(&super->magic), BTRFS_MAGIC,
1993 sizeof(super->magic))) {
1994 brelse(bh);
1995 continue;
1996 }
1997
1998 if (!latest || btrfs_super_generation(super) > transid) {
1999 brelse(latest);
2000 latest = bh;
2001 transid = btrfs_super_generation(super);
2002 } else {
2003 brelse(bh);
2004 }
2005 }
2006 return latest;
2007 }
2008
2009 static int write_dev_supers(struct btrfs_device *device,
2010 struct btrfs_super_block *sb,
2011 int do_barriers, int wait, int max_mirrors)
2012 {
2013 struct buffer_head *bh;
2014 int i;
2015 int ret;
2016 int errors = 0;
2017 u32 crc;
2018 u64 bytenr;
2019 int last_barrier = 0;
2020
2021 if (max_mirrors == 0)
2022 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2023
2024 /* make sure only the last submit_bh does a barrier */
2025 if (do_barriers) {
2026 for (i = 0; i < max_mirrors; i++) {
2027 bytenr = btrfs_sb_offset(i);
2028 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2029 device->total_bytes)
2030 break;
2031 last_barrier = i;
2032 }
2033 }
2034
2035 for (i = 0; i < max_mirrors; i++) {
2036 bytenr = btrfs_sb_offset(i);
2037 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2038 break;
2039
2040 if (wait) {
2041 bh = __find_get_block(device->bdev, bytenr / 4096,
2042 BTRFS_SUPER_INFO_SIZE);
2043 BUG_ON(!bh);
2044 brelse(bh);
2045 wait_on_buffer(bh);
2046 if (buffer_uptodate(bh)) {
2047 brelse(bh);
2048 continue;
2049 }
2050 } else {
2051 btrfs_set_super_bytenr(sb, bytenr);
2052
2053 crc = ~(u32)0;
2054 crc = btrfs_csum_data(NULL, (char *)sb +
2055 BTRFS_CSUM_SIZE, crc,
2056 BTRFS_SUPER_INFO_SIZE -
2057 BTRFS_CSUM_SIZE);
2058 btrfs_csum_final(crc, sb->csum);
2059
2060 bh = __getblk(device->bdev, bytenr / 4096,
2061 BTRFS_SUPER_INFO_SIZE);
2062 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2063
2064 set_buffer_uptodate(bh);
2065 get_bh(bh);
2066 lock_buffer(bh);
2067 bh->b_end_io = btrfs_end_buffer_write_sync;
2068 }
2069
2070 if (i == last_barrier && do_barriers && device->barriers) {
2071 ret = submit_bh(WRITE_BARRIER, bh);
2072 if (ret == -EOPNOTSUPP) {
2073 printk("btrfs: disabling barriers on dev %s\n",
2074 device->name);
2075 set_buffer_uptodate(bh);
2076 device->barriers = 0;
2077 get_bh(bh);
2078 lock_buffer(bh);
2079 ret = submit_bh(WRITE, bh);
2080 }
2081 } else {
2082 ret = submit_bh(WRITE, bh);
2083 }
2084
2085 if (!ret && wait) {
2086 wait_on_buffer(bh);
2087 if (!buffer_uptodate(bh))
2088 errors++;
2089 } else if (ret) {
2090 errors++;
2091 }
2092 if (wait)
2093 brelse(bh);
2094 }
2095 return errors < i ? 0 : -1;
2096 }
2097
2098 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2099 {
2100 struct list_head *head = &root->fs_info->fs_devices->devices;
2101 struct btrfs_device *dev;
2102 struct btrfs_super_block *sb;
2103 struct btrfs_dev_item *dev_item;
2104 int ret;
2105 int do_barriers;
2106 int max_errors;
2107 int total_errors = 0;
2108 u64 flags;
2109
2110 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2111 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2112
2113 sb = &root->fs_info->super_for_commit;
2114 dev_item = &sb->dev_item;
2115 list_for_each_entry(dev, head, dev_list) {
2116 if (!dev->bdev) {
2117 total_errors++;
2118 continue;
2119 }
2120 if (!dev->in_fs_metadata || !dev->writeable)
2121 continue;
2122
2123 btrfs_set_stack_device_generation(dev_item, 0);
2124 btrfs_set_stack_device_type(dev_item, dev->type);
2125 btrfs_set_stack_device_id(dev_item, dev->devid);
2126 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2127 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2128 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2129 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2130 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2131 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2132 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2133
2134 flags = btrfs_super_flags(sb);
2135 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2136
2137 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2138 if (ret)
2139 total_errors++;
2140 }
2141 if (total_errors > max_errors) {
2142 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2143 total_errors);
2144 BUG();
2145 }
2146
2147 total_errors = 0;
2148 list_for_each_entry(dev, head, dev_list) {
2149 if (!dev->bdev)
2150 continue;
2151 if (!dev->in_fs_metadata || !dev->writeable)
2152 continue;
2153
2154 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2155 if (ret)
2156 total_errors++;
2157 }
2158 if (total_errors > max_errors) {
2159 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2160 total_errors);
2161 BUG();
2162 }
2163 return 0;
2164 }
2165
2166 int write_ctree_super(struct btrfs_trans_handle *trans,
2167 struct btrfs_root *root, int max_mirrors)
2168 {
2169 int ret;
2170
2171 ret = write_all_supers(root, max_mirrors);
2172 return ret;
2173 }
2174
2175 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2176 {
2177 radix_tree_delete(&fs_info->fs_roots_radix,
2178 (unsigned long)root->root_key.objectid);
2179 if (root->anon_super.s_dev) {
2180 down_write(&root->anon_super.s_umount);
2181 kill_anon_super(&root->anon_super);
2182 }
2183 if (root->node)
2184 free_extent_buffer(root->node);
2185 if (root->commit_root)
2186 free_extent_buffer(root->commit_root);
2187 kfree(root->name);
2188 kfree(root);
2189 return 0;
2190 }
2191
2192 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2193 {
2194 int ret;
2195 struct btrfs_root *gang[8];
2196 int i;
2197
2198 while (1) {
2199 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2200 (void **)gang, 0,
2201 ARRAY_SIZE(gang));
2202 if (!ret)
2203 break;
2204 for (i = 0; i < ret; i++)
2205 btrfs_free_fs_root(fs_info, gang[i]);
2206 }
2207 return 0;
2208 }
2209
2210 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2211 {
2212 u64 root_objectid = 0;
2213 struct btrfs_root *gang[8];
2214 int i;
2215 int ret;
2216
2217 while (1) {
2218 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2219 (void **)gang, root_objectid,
2220 ARRAY_SIZE(gang));
2221 if (!ret)
2222 break;
2223 for (i = 0; i < ret; i++) {
2224 root_objectid = gang[i]->root_key.objectid;
2225 ret = btrfs_find_dead_roots(fs_info->tree_root,
2226 root_objectid, gang[i]);
2227 BUG_ON(ret);
2228 btrfs_orphan_cleanup(gang[i]);
2229 }
2230 root_objectid++;
2231 }
2232 return 0;
2233 }
2234
2235 int btrfs_commit_super(struct btrfs_root *root)
2236 {
2237 struct btrfs_trans_handle *trans;
2238 int ret;
2239
2240 mutex_lock(&root->fs_info->cleaner_mutex);
2241 btrfs_clean_old_snapshots(root);
2242 mutex_unlock(&root->fs_info->cleaner_mutex);
2243 trans = btrfs_start_transaction(root, 1);
2244 ret = btrfs_commit_transaction(trans, root);
2245 BUG_ON(ret);
2246 /* run commit again to drop the original snapshot */
2247 trans = btrfs_start_transaction(root, 1);
2248 btrfs_commit_transaction(trans, root);
2249 ret = btrfs_write_and_wait_transaction(NULL, root);
2250 BUG_ON(ret);
2251
2252 ret = write_ctree_super(NULL, root, 0);
2253 return ret;
2254 }
2255
2256 int close_ctree(struct btrfs_root *root)
2257 {
2258 struct btrfs_fs_info *fs_info = root->fs_info;
2259 int ret;
2260
2261 fs_info->closing = 1;
2262 smp_mb();
2263
2264 kthread_stop(root->fs_info->transaction_kthread);
2265 kthread_stop(root->fs_info->cleaner_kthread);
2266
2267 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2268 ret = btrfs_commit_super(root);
2269 if (ret)
2270 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2271 }
2272
2273 if (fs_info->delalloc_bytes) {
2274 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2275 fs_info->delalloc_bytes);
2276 }
2277 if (fs_info->total_ref_cache_size) {
2278 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2279 (unsigned long long)fs_info->total_ref_cache_size);
2280 }
2281
2282 if (fs_info->extent_root->node)
2283 free_extent_buffer(fs_info->extent_root->node);
2284
2285 if (fs_info->tree_root->node)
2286 free_extent_buffer(fs_info->tree_root->node);
2287
2288 if (root->fs_info->chunk_root->node)
2289 free_extent_buffer(root->fs_info->chunk_root->node);
2290
2291 if (root->fs_info->dev_root->node)
2292 free_extent_buffer(root->fs_info->dev_root->node);
2293
2294 if (root->fs_info->csum_root->node)
2295 free_extent_buffer(root->fs_info->csum_root->node);
2296
2297 btrfs_free_block_groups(root->fs_info);
2298
2299 del_fs_roots(fs_info);
2300
2301 iput(fs_info->btree_inode);
2302
2303 btrfs_stop_workers(&fs_info->fixup_workers);
2304 btrfs_stop_workers(&fs_info->delalloc_workers);
2305 btrfs_stop_workers(&fs_info->workers);
2306 btrfs_stop_workers(&fs_info->endio_workers);
2307 btrfs_stop_workers(&fs_info->endio_meta_workers);
2308 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2309 btrfs_stop_workers(&fs_info->endio_write_workers);
2310 btrfs_stop_workers(&fs_info->submit_workers);
2311
2312 #if 0
2313 while (!list_empty(&fs_info->hashers)) {
2314 struct btrfs_hasher *hasher;
2315 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
2316 hashers);
2317 list_del(&hasher->hashers);
2318 crypto_free_hash(&fs_info->hash_tfm);
2319 kfree(hasher);
2320 }
2321 #endif
2322 btrfs_close_devices(fs_info->fs_devices);
2323 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2324
2325 bdi_destroy(&fs_info->bdi);
2326
2327 kfree(fs_info->extent_root);
2328 kfree(fs_info->tree_root);
2329 kfree(fs_info->chunk_root);
2330 kfree(fs_info->dev_root);
2331 kfree(fs_info->csum_root);
2332 return 0;
2333 }
2334
2335 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2336 {
2337 int ret;
2338 struct inode *btree_inode = buf->first_page->mapping->host;
2339
2340 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2341 if (!ret)
2342 return ret;
2343
2344 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2345 parent_transid);
2346 return !ret;
2347 }
2348
2349 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2350 {
2351 struct inode *btree_inode = buf->first_page->mapping->host;
2352 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2353 buf);
2354 }
2355
2356 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2357 {
2358 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2359 u64 transid = btrfs_header_generation(buf);
2360 struct inode *btree_inode = root->fs_info->btree_inode;
2361
2362 btrfs_set_lock_blocking(buf);
2363
2364 btrfs_assert_tree_locked(buf);
2365 if (transid != root->fs_info->generation) {
2366 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2367 "found %llu running %llu\n",
2368 (unsigned long long)buf->start,
2369 (unsigned long long)transid,
2370 (unsigned long long)root->fs_info->generation);
2371 WARN_ON(1);
2372 }
2373 set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
2374 }
2375
2376 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2377 {
2378 /*
2379 * looks as though older kernels can get into trouble with
2380 * this code, they end up stuck in balance_dirty_pages forever
2381 */
2382 struct extent_io_tree *tree;
2383 u64 num_dirty;
2384 u64 start = 0;
2385 unsigned long thresh = 32 * 1024 * 1024;
2386 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2387
2388 if (current_is_pdflush() || current->flags & PF_MEMALLOC)
2389 return;
2390
2391 num_dirty = count_range_bits(tree, &start, (u64)-1,
2392 thresh, EXTENT_DIRTY);
2393 if (num_dirty > thresh) {
2394 balance_dirty_pages_ratelimited_nr(
2395 root->fs_info->btree_inode->i_mapping, 1);
2396 }
2397 return;
2398 }
2399
2400 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2401 {
2402 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2403 int ret;
2404 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2405 if (ret == 0)
2406 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2407 return ret;
2408 }
2409
2410 int btree_lock_page_hook(struct page *page)
2411 {
2412 struct inode *inode = page->mapping->host;
2413 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2414 struct extent_buffer *eb;
2415 unsigned long len;
2416 u64 bytenr = page_offset(page);
2417
2418 if (page->private == EXTENT_PAGE_PRIVATE)
2419 goto out;
2420
2421 len = page->private >> 2;
2422 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2423 if (!eb)
2424 goto out;
2425
2426 btrfs_tree_lock(eb);
2427 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2428 btrfs_tree_unlock(eb);
2429 free_extent_buffer(eb);
2430 out:
2431 lock_page(page);
2432 return 0;
2433 }
2434
2435 static struct extent_io_ops btree_extent_io_ops = {
2436 .write_cache_pages_lock_hook = btree_lock_page_hook,
2437 .readpage_end_io_hook = btree_readpage_end_io_hook,
2438 .submit_bio_hook = btree_submit_bio_hook,
2439 /* note we're sharing with inode.c for the merge bio hook */
2440 .merge_bio_hook = btrfs_merge_bio_hook,
2441 };
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree