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drm/i915: fix up error path leak in i915_cmdbuffer
[linux-2.6/mini2440.git] / fs / btrfs / disk-io.c
blob92caa8035f36f9beecc3c21551722a0eefdd911e
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 #include "free-space-cache.h"
42
43 static struct extent_io_ops btree_extent_io_ops;
44 static void end_workqueue_fn(struct btrfs_work *work);
45
46 /*
47 * end_io_wq structs are used to do processing in task context when an IO is
48 * complete. This is used during reads to verify checksums, and it is used
49 * by writes to insert metadata for new file extents after IO is complete.
50 */
51 struct end_io_wq {
52 struct bio *bio;
53 bio_end_io_t *end_io;
54 void *private;
55 struct btrfs_fs_info *info;
56 int error;
57 int metadata;
58 struct list_head list;
59 struct btrfs_work work;
60 };
61
62 /*
63 * async submit bios are used to offload expensive checksumming
64 * onto the worker threads. They checksum file and metadata bios
65 * just before they are sent down the IO stack.
66 */
67 struct async_submit_bio {
68 struct inode *inode;
69 struct bio *bio;
70 struct list_head list;
71 extent_submit_bio_hook_t *submit_bio_start;
72 extent_submit_bio_hook_t *submit_bio_done;
73 int rw;
74 int mirror_num;
75 unsigned long bio_flags;
76 struct btrfs_work work;
77 };
78
79 /* These are used to set the lockdep class on the extent buffer locks.
80 * The class is set by the readpage_end_io_hook after the buffer has
81 * passed csum validation but before the pages are unlocked.
82 *
83 * The lockdep class is also set by btrfs_init_new_buffer on freshly
84 * allocated blocks.
85 *
86 * The class is based on the level in the tree block, which allows lockdep
87 * to know that lower nodes nest inside the locks of higher nodes.
88 *
89 * We also add a check to make sure the highest level of the tree is
90 * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this
91 * code needs update as well.
92 */
93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
94 # if BTRFS_MAX_LEVEL != 8
95 # error
96 # endif
97 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
98 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
99 /* leaf */
100 "btrfs-extent-00",
101 "btrfs-extent-01",
102 "btrfs-extent-02",
103 "btrfs-extent-03",
104 "btrfs-extent-04",
105 "btrfs-extent-05",
106 "btrfs-extent-06",
107 "btrfs-extent-07",
108 /* highest possible level */
109 "btrfs-extent-08",
110 };
111 #endif
112
113 /*
114 * extents on the btree inode are pretty simple, there's one extent
115 * that covers the entire device
116 */
117 static struct extent_map *btree_get_extent(struct inode *inode,
118 struct page *page, size_t page_offset, u64 start, u64 len,
119 int create)
120 {
121 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
122 struct extent_map *em;
123 int ret;
124
125 spin_lock(&em_tree->lock);
126 em = lookup_extent_mapping(em_tree, start, len);
127 if (em) {
128 em->bdev =
129 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
130 spin_unlock(&em_tree->lock);
131 goto out;
132 }
133 spin_unlock(&em_tree->lock);
134
135 em = alloc_extent_map(GFP_NOFS);
136 if (!em) {
137 em = ERR_PTR(-ENOMEM);
138 goto out;
139 }
140 em->start = 0;
141 em->len = (u64)-1;
142 em->block_len = (u64)-1;
143 em->block_start = 0;
144 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
145
146 spin_lock(&em_tree->lock);
147 ret = add_extent_mapping(em_tree, em);
148 if (ret == -EEXIST) {
149 u64 failed_start = em->start;
150 u64 failed_len = em->len;
151
152 free_extent_map(em);
153 em = lookup_extent_mapping(em_tree, start, len);
154 if (em) {
155 ret = 0;
156 } else {
157 em = lookup_extent_mapping(em_tree, failed_start,
158 failed_len);
159 ret = -EIO;
160 }
161 } else if (ret) {
162 free_extent_map(em);
163 em = NULL;
164 }
165 spin_unlock(&em_tree->lock);
166
167 if (ret)
168 em = ERR_PTR(ret);
169 out:
170 return em;
171 }
172
173 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
174 {
175 return btrfs_crc32c(seed, data, len);
176 }
177
178 void btrfs_csum_final(u32 crc, char *result)
179 {
180 *(__le32 *)result = ~cpu_to_le32(crc);
181 }
182
183 /*
184 * compute the csum for a btree block, and either verify it or write it
185 * into the csum field of the block.
186 */
187 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
188 int verify)
189 {
190 u16 csum_size =
191 btrfs_super_csum_size(&root->fs_info->super_copy);
192 char *result = NULL;
193 unsigned long len;
194 unsigned long cur_len;
195 unsigned long offset = BTRFS_CSUM_SIZE;
196 char *map_token = NULL;
197 char *kaddr;
198 unsigned long map_start;
199 unsigned long map_len;
200 int err;
201 u32 crc = ~(u32)0;
202 unsigned long inline_result;
203
204 len = buf->len - offset;
205 while (len > 0) {
206 err = map_private_extent_buffer(buf, offset, 32,
207 &map_token, &kaddr,
208 &map_start, &map_len, KM_USER0);
209 if (err)
210 return 1;
211 cur_len = min(len, map_len - (offset - map_start));
212 crc = btrfs_csum_data(root, kaddr + offset - map_start,
213 crc, cur_len);
214 len -= cur_len;
215 offset += cur_len;
216 unmap_extent_buffer(buf, map_token, KM_USER0);
217 }
218 if (csum_size > sizeof(inline_result)) {
219 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
220 if (!result)
221 return 1;
222 } else {
223 result = (char *)&inline_result;
224 }
225
226 btrfs_csum_final(crc, result);
227
228 if (verify) {
229 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
230 u32 val;
231 u32 found = 0;
232 memcpy(&found, result, csum_size);
233
234 read_extent_buffer(buf, &val, 0, csum_size);
235 printk(KERN_INFO "btrfs: %s checksum verify failed "
236 "on %llu wanted %X found %X level %d\n",
237 root->fs_info->sb->s_id,
238 buf->start, val, found, btrfs_header_level(buf));
239 if (result != (char *)&inline_result)
240 kfree(result);
241 return 1;
242 }
243 } else {
244 write_extent_buffer(buf, result, 0, csum_size);
245 }
246 if (result != (char *)&inline_result)
247 kfree(result);
248 return 0;
249 }
250
251 /*
252 * we can't consider a given block up to date unless the transid of the
253 * block matches the transid in the parent node's pointer. This is how we
254 * detect blocks that either didn't get written at all or got written
255 * in the wrong place.
256 */
257 static int verify_parent_transid(struct extent_io_tree *io_tree,
258 struct extent_buffer *eb, u64 parent_transid)
259 {
260 int ret;
261
262 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
263 return 0;
264
265 lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
266 if (extent_buffer_uptodate(io_tree, eb) &&
267 btrfs_header_generation(eb) == parent_transid) {
268 ret = 0;
269 goto out;
270 }
271 printk("parent transid verify failed on %llu wanted %llu found %llu\n",
272 (unsigned long long)eb->start,
273 (unsigned long long)parent_transid,
274 (unsigned long long)btrfs_header_generation(eb));
275 ret = 1;
276 clear_extent_buffer_uptodate(io_tree, eb);
277 out:
278 unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
279 GFP_NOFS);
280 return ret;
281 }
282
283 /*
284 * helper to read a given tree block, doing retries as required when
285 * the checksums don't match and we have alternate mirrors to try.
286 */
287 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
288 struct extent_buffer *eb,
289 u64 start, u64 parent_transid)
290 {
291 struct extent_io_tree *io_tree;
292 int ret;
293 int num_copies = 0;
294 int mirror_num = 0;
295
296 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
297 while (1) {
298 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
299 btree_get_extent, mirror_num);
300 if (!ret &&
301 !verify_parent_transid(io_tree, eb, parent_transid))
302 return ret;
303
304 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
305 eb->start, eb->len);
306 if (num_copies == 1)
307 return ret;
308
309 mirror_num++;
310 if (mirror_num > num_copies)
311 return ret;
312 }
313 return -EIO;
314 }
315
316 /*
317 * checksum a dirty tree block before IO. This has extra checks to make sure
318 * we only fill in the checksum field in the first page of a multi-page block
319 */
320
321 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
322 {
323 struct extent_io_tree *tree;
324 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
325 u64 found_start;
326 int found_level;
327 unsigned long len;
328 struct extent_buffer *eb;
329 int ret;
330
331 tree = &BTRFS_I(page->mapping->host)->io_tree;
332
333 if (page->private == EXTENT_PAGE_PRIVATE)
334 goto out;
335 if (!page->private)
336 goto out;
337 len = page->private >> 2;
338 WARN_ON(len == 0);
339
340 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
341 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
342 btrfs_header_generation(eb));
343 BUG_ON(ret);
344 found_start = btrfs_header_bytenr(eb);
345 if (found_start != start) {
346 WARN_ON(1);
347 goto err;
348 }
349 if (eb->first_page != page) {
350 WARN_ON(1);
351 goto err;
352 }
353 if (!PageUptodate(page)) {
354 WARN_ON(1);
355 goto err;
356 }
357 found_level = btrfs_header_level(eb);
358
359 csum_tree_block(root, eb, 0);
360 err:
361 free_extent_buffer(eb);
362 out:
363 return 0;
364 }
365
366 static int check_tree_block_fsid(struct btrfs_root *root,
367 struct extent_buffer *eb)
368 {
369 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
370 u8 fsid[BTRFS_UUID_SIZE];
371 int ret = 1;
372
373 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
374 BTRFS_FSID_SIZE);
375 while (fs_devices) {
376 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
377 ret = 0;
378 break;
379 }
380 fs_devices = fs_devices->seed;
381 }
382 return ret;
383 }
384
385 #ifdef CONFIG_DEBUG_LOCK_ALLOC
386 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
387 {
388 lockdep_set_class_and_name(&eb->lock,
389 &btrfs_eb_class[level],
390 btrfs_eb_name[level]);
391 }
392 #endif
393
394 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
395 struct extent_state *state)
396 {
397 struct extent_io_tree *tree;
398 u64 found_start;
399 int found_level;
400 unsigned long len;
401 struct extent_buffer *eb;
402 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
403 int ret = 0;
404
405 tree = &BTRFS_I(page->mapping->host)->io_tree;
406 if (page->private == EXTENT_PAGE_PRIVATE)
407 goto out;
408 if (!page->private)
409 goto out;
410
411 len = page->private >> 2;
412 WARN_ON(len == 0);
413
414 eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
415
416 found_start = btrfs_header_bytenr(eb);
417 if (found_start != start) {
418 printk(KERN_INFO "btrfs bad tree block start %llu %llu\n",
419 (unsigned long long)found_start,
420 (unsigned long long)eb->start);
421 ret = -EIO;
422 goto err;
423 }
424 if (eb->first_page != page) {
425 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
426 eb->first_page->index, page->index);
427 WARN_ON(1);
428 ret = -EIO;
429 goto err;
430 }
431 if (check_tree_block_fsid(root, eb)) {
432 printk(KERN_INFO "btrfs bad fsid on block %llu\n",
433 (unsigned long long)eb->start);
434 ret = -EIO;
435 goto err;
436 }
437 found_level = btrfs_header_level(eb);
438
439 btrfs_set_buffer_lockdep_class(eb, found_level);
440
441 ret = csum_tree_block(root, eb, 1);
442 if (ret)
443 ret = -EIO;
444
445 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
446 end = eb->start + end - 1;
447 err:
448 free_extent_buffer(eb);
449 out:
450 return ret;
451 }
452
453 static void end_workqueue_bio(struct bio *bio, int err)
454 {
455 struct end_io_wq *end_io_wq = bio->bi_private;
456 struct btrfs_fs_info *fs_info;
457
458 fs_info = end_io_wq->info;
459 end_io_wq->error = err;
460 end_io_wq->work.func = end_workqueue_fn;
461 end_io_wq->work.flags = 0;
462
463 if (bio->bi_rw & (1 << BIO_RW)) {
464 if (end_io_wq->metadata)
465 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
466 &end_io_wq->work);
467 else
468 btrfs_queue_worker(&fs_info->endio_write_workers,
469 &end_io_wq->work);
470 } else {
471 if (end_io_wq->metadata)
472 btrfs_queue_worker(&fs_info->endio_meta_workers,
473 &end_io_wq->work);
474 else
475 btrfs_queue_worker(&fs_info->endio_workers,
476 &end_io_wq->work);
477 }
478 }
479
480 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
481 int metadata)
482 {
483 struct end_io_wq *end_io_wq;
484 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
485 if (!end_io_wq)
486 return -ENOMEM;
487
488 end_io_wq->private = bio->bi_private;
489 end_io_wq->end_io = bio->bi_end_io;
490 end_io_wq->info = info;
491 end_io_wq->error = 0;
492 end_io_wq->bio = bio;
493 end_io_wq->metadata = metadata;
494
495 bio->bi_private = end_io_wq;
496 bio->bi_end_io = end_workqueue_bio;
497 return 0;
498 }
499
500 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
501 {
502 unsigned long limit = min_t(unsigned long,
503 info->workers.max_workers,
504 info->fs_devices->open_devices);
505 return 256 * limit;
506 }
507
508 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
509 {
510 return atomic_read(&info->nr_async_bios) >
511 btrfs_async_submit_limit(info);
512 }
513
514 static void run_one_async_start(struct btrfs_work *work)
515 {
516 struct btrfs_fs_info *fs_info;
517 struct async_submit_bio *async;
518
519 async = container_of(work, struct async_submit_bio, work);
520 fs_info = BTRFS_I(async->inode)->root->fs_info;
521 async->submit_bio_start(async->inode, async->rw, async->bio,
522 async->mirror_num, async->bio_flags);
523 }
524
525 static void run_one_async_done(struct btrfs_work *work)
526 {
527 struct btrfs_fs_info *fs_info;
528 struct async_submit_bio *async;
529 int limit;
530
531 async = container_of(work, struct async_submit_bio, work);
532 fs_info = BTRFS_I(async->inode)->root->fs_info;
533
534 limit = btrfs_async_submit_limit(fs_info);
535 limit = limit * 2 / 3;
536
537 atomic_dec(&fs_info->nr_async_submits);
538
539 if (atomic_read(&fs_info->nr_async_submits) < limit &&
540 waitqueue_active(&fs_info->async_submit_wait))
541 wake_up(&fs_info->async_submit_wait);
542
543 async->submit_bio_done(async->inode, async->rw, async->bio,
544 async->mirror_num, async->bio_flags);
545 }
546
547 static void run_one_async_free(struct btrfs_work *work)
548 {
549 struct async_submit_bio *async;
550
551 async = container_of(work, struct async_submit_bio, work);
552 kfree(async);
553 }
554
555 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
556 int rw, struct bio *bio, int mirror_num,
557 unsigned long bio_flags,
558 extent_submit_bio_hook_t *submit_bio_start,
559 extent_submit_bio_hook_t *submit_bio_done)
560 {
561 struct async_submit_bio *async;
562
563 async = kmalloc(sizeof(*async), GFP_NOFS);
564 if (!async)
565 return -ENOMEM;
566
567 async->inode = inode;
568 async->rw = rw;
569 async->bio = bio;
570 async->mirror_num = mirror_num;
571 async->submit_bio_start = submit_bio_start;
572 async->submit_bio_done = submit_bio_done;
573
574 async->work.func = run_one_async_start;
575 async->work.ordered_func = run_one_async_done;
576 async->work.ordered_free = run_one_async_free;
577
578 async->work.flags = 0;
579 async->bio_flags = bio_flags;
580
581 atomic_inc(&fs_info->nr_async_submits);
582 btrfs_queue_worker(&fs_info->workers, &async->work);
583 #if 0
584 int limit = btrfs_async_submit_limit(fs_info);
585 if (atomic_read(&fs_info->nr_async_submits) > limit) {
586 wait_event_timeout(fs_info->async_submit_wait,
587 (atomic_read(&fs_info->nr_async_submits) < limit),
588 HZ/10);
589
590 wait_event_timeout(fs_info->async_submit_wait,
591 (atomic_read(&fs_info->nr_async_bios) < limit),
592 HZ/10);
593 }
594 #endif
595 while (atomic_read(&fs_info->async_submit_draining) &&
596 atomic_read(&fs_info->nr_async_submits)) {
597 wait_event(fs_info->async_submit_wait,
598 (atomic_read(&fs_info->nr_async_submits) == 0));
599 }
600
601 return 0;
602 }
603
604 static int btree_csum_one_bio(struct bio *bio)
605 {
606 struct bio_vec *bvec = bio->bi_io_vec;
607 int bio_index = 0;
608 struct btrfs_root *root;
609
610 WARN_ON(bio->bi_vcnt <= 0);
611 while (bio_index < bio->bi_vcnt) {
612 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
613 csum_dirty_buffer(root, bvec->bv_page);
614 bio_index++;
615 bvec++;
616 }
617 return 0;
618 }
619
620 static int __btree_submit_bio_start(struct inode *inode, int rw,
621 struct bio *bio, int mirror_num,
622 unsigned long bio_flags)
623 {
624 /*
625 * when we're called for a write, we're already in the async
626 * submission context. Just jump into btrfs_map_bio
627 */
628 btree_csum_one_bio(bio);
629 return 0;
630 }
631
632 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
633 int mirror_num, unsigned long bio_flags)
634 {
635 /*
636 * when we're called for a write, we're already in the async
637 * submission context. Just jump into btrfs_map_bio
638 */
639 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
640 }
641
642 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
643 int mirror_num, unsigned long bio_flags)
644 {
645 int ret;
646
647 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
648 bio, 1);
649 BUG_ON(ret);
650
651 if (!(rw & (1 << BIO_RW))) {
652 /*
653 * called for a read, do the setup so that checksum validation
654 * can happen in the async kernel threads
655 */
656 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
657 mirror_num, 0);
658 }
659 /*
660 * kthread helpers are used to submit writes so that checksumming
661 * can happen in parallel across all CPUs
662 */
663 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
664 inode, rw, bio, mirror_num, 0,
665 __btree_submit_bio_start,
666 __btree_submit_bio_done);
667 }
668
669 static int btree_writepage(struct page *page, struct writeback_control *wbc)
670 {
671 struct extent_io_tree *tree;
672 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
673 struct extent_buffer *eb;
674 int was_dirty;
675
676 tree = &BTRFS_I(page->mapping->host)->io_tree;
677 if (!(current->flags & PF_MEMALLOC)) {
678 return extent_write_full_page(tree, page,
679 btree_get_extent, wbc);
680 }
681
682 redirty_page_for_writepage(wbc, page);
683 eb = btrfs_find_tree_block(root, page_offset(page),
684 PAGE_CACHE_SIZE);
685 WARN_ON(!eb);
686
687 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
688 if (!was_dirty) {
689 spin_lock(&root->fs_info->delalloc_lock);
690 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
691 spin_unlock(&root->fs_info->delalloc_lock);
692 }
693 free_extent_buffer(eb);
694
695 unlock_page(page);
696 return 0;
697 }
698
699 static int btree_writepages(struct address_space *mapping,
700 struct writeback_control *wbc)
701 {
702 struct extent_io_tree *tree;
703 tree = &BTRFS_I(mapping->host)->io_tree;
704 if (wbc->sync_mode == WB_SYNC_NONE) {
705 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
706 u64 num_dirty;
707 unsigned long thresh = 32 * 1024 * 1024;
708
709 if (wbc->for_kupdate)
710 return 0;
711
712 /* this is a bit racy, but that's ok */
713 num_dirty = root->fs_info->dirty_metadata_bytes;
714 if (num_dirty < thresh)
715 return 0;
716 }
717 return extent_writepages(tree, mapping, btree_get_extent, wbc);
718 }
719
720 static int btree_readpage(struct file *file, struct page *page)
721 {
722 struct extent_io_tree *tree;
723 tree = &BTRFS_I(page->mapping->host)->io_tree;
724 return extent_read_full_page(tree, page, btree_get_extent);
725 }
726
727 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
728 {
729 struct extent_io_tree *tree;
730 struct extent_map_tree *map;
731 int ret;
732
733 if (PageWriteback(page) || PageDirty(page))
734 return 0;
735
736 tree = &BTRFS_I(page->mapping->host)->io_tree;
737 map = &BTRFS_I(page->mapping->host)->extent_tree;
738
739 ret = try_release_extent_state(map, tree, page, gfp_flags);
740 if (!ret)
741 return 0;
742
743 ret = try_release_extent_buffer(tree, page);
744 if (ret == 1) {
745 ClearPagePrivate(page);
746 set_page_private(page, 0);
747 page_cache_release(page);
748 }
749
750 return ret;
751 }
752
753 static void btree_invalidatepage(struct page *page, unsigned long offset)
754 {
755 struct extent_io_tree *tree;
756 tree = &BTRFS_I(page->mapping->host)->io_tree;
757 extent_invalidatepage(tree, page, offset);
758 btree_releasepage(page, GFP_NOFS);
759 if (PagePrivate(page)) {
760 printk(KERN_WARNING "btrfs warning page private not zero "
761 "on page %llu\n", (unsigned long long)page_offset(page));
762 ClearPagePrivate(page);
763 set_page_private(page, 0);
764 page_cache_release(page);
765 }
766 }
767
768 #if 0
769 static int btree_writepage(struct page *page, struct writeback_control *wbc)
770 {
771 struct buffer_head *bh;
772 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
773 struct buffer_head *head;
774 if (!page_has_buffers(page)) {
775 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
776 (1 << BH_Dirty)|(1 << BH_Uptodate));
777 }
778 head = page_buffers(page);
779 bh = head;
780 do {
781 if (buffer_dirty(bh))
782 csum_tree_block(root, bh, 0);
783 bh = bh->b_this_page;
784 } while (bh != head);
785 return block_write_full_page(page, btree_get_block, wbc);
786 }
787 #endif
788
789 static struct address_space_operations btree_aops = {
790 .readpage = btree_readpage,
791 .writepage = btree_writepage,
792 .writepages = btree_writepages,
793 .releasepage = btree_releasepage,
794 .invalidatepage = btree_invalidatepage,
795 .sync_page = block_sync_page,
796 };
797
798 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
799 u64 parent_transid)
800 {
801 struct extent_buffer *buf = NULL;
802 struct inode *btree_inode = root->fs_info->btree_inode;
803 int ret = 0;
804
805 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
806 if (!buf)
807 return 0;
808 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
809 buf, 0, 0, btree_get_extent, 0);
810 free_extent_buffer(buf);
811 return ret;
812 }
813
814 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
815 u64 bytenr, u32 blocksize)
816 {
817 struct inode *btree_inode = root->fs_info->btree_inode;
818 struct extent_buffer *eb;
819 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
820 bytenr, blocksize, GFP_NOFS);
821 return eb;
822 }
823
824 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
825 u64 bytenr, u32 blocksize)
826 {
827 struct inode *btree_inode = root->fs_info->btree_inode;
828 struct extent_buffer *eb;
829
830 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
831 bytenr, blocksize, NULL, GFP_NOFS);
832 return eb;
833 }
834
835
836 int btrfs_write_tree_block(struct extent_buffer *buf)
837 {
838 return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
839 buf->start + buf->len - 1, WB_SYNC_ALL);
840 }
841
842 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
843 {
844 return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
845 buf->start, buf->start + buf->len - 1);
846 }
847
848 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
849 u32 blocksize, u64 parent_transid)
850 {
851 struct extent_buffer *buf = NULL;
852 struct inode *btree_inode = root->fs_info->btree_inode;
853 struct extent_io_tree *io_tree;
854 int ret;
855
856 io_tree = &BTRFS_I(btree_inode)->io_tree;
857
858 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
859 if (!buf)
860 return NULL;
861
862 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
863
864 if (ret == 0)
865 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
866 else
867 WARN_ON(1);
868 return buf;
869
870 }
871
872 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
873 struct extent_buffer *buf)
874 {
875 struct inode *btree_inode = root->fs_info->btree_inode;
876 if (btrfs_header_generation(buf) ==
877 root->fs_info->running_transaction->transid) {
878 btrfs_assert_tree_locked(buf);
879
880 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
881 spin_lock(&root->fs_info->delalloc_lock);
882 if (root->fs_info->dirty_metadata_bytes >= buf->len)
883 root->fs_info->dirty_metadata_bytes -= buf->len;
884 else
885 WARN_ON(1);
886 spin_unlock(&root->fs_info->delalloc_lock);
887 }
888
889 /* ugh, clear_extent_buffer_dirty needs to lock the page */
890 btrfs_set_lock_blocking(buf);
891 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
892 buf);
893 }
894 return 0;
895 }
896
897 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
898 u32 stripesize, struct btrfs_root *root,
899 struct btrfs_fs_info *fs_info,
900 u64 objectid)
901 {
902 root->node = NULL;
903 root->commit_root = NULL;
904 root->ref_tree = NULL;
905 root->sectorsize = sectorsize;
906 root->nodesize = nodesize;
907 root->leafsize = leafsize;
908 root->stripesize = stripesize;
909 root->ref_cows = 0;
910 root->track_dirty = 0;
911
912 root->fs_info = fs_info;
913 root->objectid = objectid;
914 root->last_trans = 0;
915 root->highest_inode = 0;
916 root->last_inode_alloc = 0;
917 root->name = NULL;
918 root->in_sysfs = 0;
919
920 INIT_LIST_HEAD(&root->dirty_list);
921 INIT_LIST_HEAD(&root->orphan_list);
922 INIT_LIST_HEAD(&root->dead_list);
923 spin_lock_init(&root->node_lock);
924 spin_lock_init(&root->list_lock);
925 mutex_init(&root->objectid_mutex);
926 mutex_init(&root->log_mutex);
927 init_waitqueue_head(&root->log_writer_wait);
928 init_waitqueue_head(&root->log_commit_wait[0]);
929 init_waitqueue_head(&root->log_commit_wait[1]);
930 atomic_set(&root->log_commit[0], 0);
931 atomic_set(&root->log_commit[1], 0);
932 atomic_set(&root->log_writers, 0);
933 root->log_batch = 0;
934 root->log_transid = 0;
935 extent_io_tree_init(&root->dirty_log_pages,
936 fs_info->btree_inode->i_mapping, GFP_NOFS);
937
938 btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
939 root->ref_tree = &root->ref_tree_struct;
940
941 memset(&root->root_key, 0, sizeof(root->root_key));
942 memset(&root->root_item, 0, sizeof(root->root_item));
943 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
944 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
945 root->defrag_trans_start = fs_info->generation;
946 init_completion(&root->kobj_unregister);
947 root->defrag_running = 0;
948 root->defrag_level = 0;
949 root->root_key.objectid = objectid;
950 root->anon_super.s_root = NULL;
951 root->anon_super.s_dev = 0;
952 INIT_LIST_HEAD(&root->anon_super.s_list);
953 INIT_LIST_HEAD(&root->anon_super.s_instances);
954 init_rwsem(&root->anon_super.s_umount);
955
956 return 0;
957 }
958
959 static int find_and_setup_root(struct btrfs_root *tree_root,
960 struct btrfs_fs_info *fs_info,
961 u64 objectid,
962 struct btrfs_root *root)
963 {
964 int ret;
965 u32 blocksize;
966 u64 generation;
967
968 __setup_root(tree_root->nodesize, tree_root->leafsize,
969 tree_root->sectorsize, tree_root->stripesize,
970 root, fs_info, objectid);
971 ret = btrfs_find_last_root(tree_root, objectid,
972 &root->root_item, &root->root_key);
973 BUG_ON(ret);
974
975 generation = btrfs_root_generation(&root->root_item);
976 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
977 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
978 blocksize, generation);
979 BUG_ON(!root->node);
980 return 0;
981 }
982
983 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
984 struct btrfs_fs_info *fs_info)
985 {
986 struct extent_buffer *eb;
987 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
988 u64 start = 0;
989 u64 end = 0;
990 int ret;
991
992 if (!log_root_tree)
993 return 0;
994
995 while (1) {
996 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
997 0, &start, &end, EXTENT_DIRTY);
998 if (ret)
999 break;
1000
1001 clear_extent_dirty(&log_root_tree->dirty_log_pages,
1002 start, end, GFP_NOFS);
1003 }
1004 eb = fs_info->log_root_tree->node;
1005
1006 WARN_ON(btrfs_header_level(eb) != 0);
1007 WARN_ON(btrfs_header_nritems(eb) != 0);
1008
1009 ret = btrfs_free_reserved_extent(fs_info->tree_root,
1010 eb->start, eb->len);
1011 BUG_ON(ret);
1012
1013 free_extent_buffer(eb);
1014 kfree(fs_info->log_root_tree);
1015 fs_info->log_root_tree = NULL;
1016 return 0;
1017 }
1018
1019 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1020 struct btrfs_fs_info *fs_info)
1021 {
1022 struct btrfs_root *root;
1023 struct btrfs_root *tree_root = fs_info->tree_root;
1024 struct extent_buffer *leaf;
1025
1026 root = kzalloc(sizeof(*root), GFP_NOFS);
1027 if (!root)
1028 return ERR_PTR(-ENOMEM);
1029
1030 __setup_root(tree_root->nodesize, tree_root->leafsize,
1031 tree_root->sectorsize, tree_root->stripesize,
1032 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1033
1034 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1035 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1036 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1037 /*
1038 * log trees do not get reference counted because they go away
1039 * before a real commit is actually done. They do store pointers
1040 * to file data extents, and those reference counts still get
1041 * updated (along with back refs to the log tree).
1042 */
1043 root->ref_cows = 0;
1044
1045 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1046 0, BTRFS_TREE_LOG_OBJECTID,
1047 trans->transid, 0, 0, 0);
1048 if (IS_ERR(leaf)) {
1049 kfree(root);
1050 return ERR_CAST(leaf);
1051 }
1052
1053 root->node = leaf;
1054 btrfs_set_header_nritems(root->node, 0);
1055 btrfs_set_header_level(root->node, 0);
1056 btrfs_set_header_bytenr(root->node, root->node->start);
1057 btrfs_set_header_generation(root->node, trans->transid);
1058 btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
1059
1060 write_extent_buffer(root->node, root->fs_info->fsid,
1061 (unsigned long)btrfs_header_fsid(root->node),
1062 BTRFS_FSID_SIZE);
1063 btrfs_mark_buffer_dirty(root->node);
1064 btrfs_tree_unlock(root->node);
1065 return root;
1066 }
1067
1068 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1069 struct btrfs_fs_info *fs_info)
1070 {
1071 struct btrfs_root *log_root;
1072
1073 log_root = alloc_log_tree(trans, fs_info);
1074 if (IS_ERR(log_root))
1075 return PTR_ERR(log_root);
1076 WARN_ON(fs_info->log_root_tree);
1077 fs_info->log_root_tree = log_root;
1078 return 0;
1079 }
1080
1081 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1082 struct btrfs_root *root)
1083 {
1084 struct btrfs_root *log_root;
1085 struct btrfs_inode_item *inode_item;
1086
1087 log_root = alloc_log_tree(trans, root->fs_info);
1088 if (IS_ERR(log_root))
1089 return PTR_ERR(log_root);
1090
1091 log_root->last_trans = trans->transid;
1092 log_root->root_key.offset = root->root_key.objectid;
1093
1094 inode_item = &log_root->root_item.inode;
1095 inode_item->generation = cpu_to_le64(1);
1096 inode_item->size = cpu_to_le64(3);
1097 inode_item->nlink = cpu_to_le32(1);
1098 inode_item->nbytes = cpu_to_le64(root->leafsize);
1099 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1100
1101 btrfs_set_root_bytenr(&log_root->root_item, log_root->node->start);
1102 btrfs_set_root_generation(&log_root->root_item, trans->transid);
1103
1104 WARN_ON(root->log_root);
1105 root->log_root = log_root;
1106 root->log_transid = 0;
1107 return 0;
1108 }
1109
1110 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1111 struct btrfs_key *location)
1112 {
1113 struct btrfs_root *root;
1114 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1115 struct btrfs_path *path;
1116 struct extent_buffer *l;
1117 u64 highest_inode;
1118 u64 generation;
1119 u32 blocksize;
1120 int ret = 0;
1121
1122 root = kzalloc(sizeof(*root), GFP_NOFS);
1123 if (!root)
1124 return ERR_PTR(-ENOMEM);
1125 if (location->offset == (u64)-1) {
1126 ret = find_and_setup_root(tree_root, fs_info,
1127 location->objectid, root);
1128 if (ret) {
1129 kfree(root);
1130 return ERR_PTR(ret);
1131 }
1132 goto insert;
1133 }
1134
1135 __setup_root(tree_root->nodesize, tree_root->leafsize,
1136 tree_root->sectorsize, tree_root->stripesize,
1137 root, fs_info, location->objectid);
1138
1139 path = btrfs_alloc_path();
1140 BUG_ON(!path);
1141 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1142 if (ret != 0) {
1143 if (ret > 0)
1144 ret = -ENOENT;
1145 goto out;
1146 }
1147 l = path->nodes[0];
1148 read_extent_buffer(l, &root->root_item,
1149 btrfs_item_ptr_offset(l, path->slots[0]),
1150 sizeof(root->root_item));
1151 memcpy(&root->root_key, location, sizeof(*location));
1152 ret = 0;
1153 out:
1154 btrfs_release_path(root, path);
1155 btrfs_free_path(path);
1156 if (ret) {
1157 kfree(root);
1158 return ERR_PTR(ret);
1159 }
1160 generation = btrfs_root_generation(&root->root_item);
1161 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1162 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1163 blocksize, generation);
1164 BUG_ON(!root->node);
1165 insert:
1166 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1167 root->ref_cows = 1;
1168 ret = btrfs_find_highest_inode(root, &highest_inode);
1169 if (ret == 0) {
1170 root->highest_inode = highest_inode;
1171 root->last_inode_alloc = highest_inode;
1172 }
1173 }
1174 return root;
1175 }
1176
1177 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1178 u64 root_objectid)
1179 {
1180 struct btrfs_root *root;
1181
1182 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
1183 return fs_info->tree_root;
1184 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
1185 return fs_info->extent_root;
1186
1187 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1188 (unsigned long)root_objectid);
1189 return root;
1190 }
1191
1192 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1193 struct btrfs_key *location)
1194 {
1195 struct btrfs_root *root;
1196 int ret;
1197
1198 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1199 return fs_info->tree_root;
1200 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1201 return fs_info->extent_root;
1202 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1203 return fs_info->chunk_root;
1204 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1205 return fs_info->dev_root;
1206 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1207 return fs_info->csum_root;
1208
1209 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1210 (unsigned long)location->objectid);
1211 if (root)
1212 return root;
1213
1214 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1215 if (IS_ERR(root))
1216 return root;
1217
1218 set_anon_super(&root->anon_super, NULL);
1219
1220 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1221 (unsigned long)root->root_key.objectid,
1222 root);
1223 if (ret) {
1224 free_extent_buffer(root->node);
1225 kfree(root);
1226 return ERR_PTR(ret);
1227 }
1228 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
1229 ret = btrfs_find_dead_roots(fs_info->tree_root,
1230 root->root_key.objectid, root);
1231 BUG_ON(ret);
1232 btrfs_orphan_cleanup(root);
1233 }
1234 return root;
1235 }
1236
1237 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1238 struct btrfs_key *location,
1239 const char *name, int namelen)
1240 {
1241 struct btrfs_root *root;
1242 int ret;
1243
1244 root = btrfs_read_fs_root_no_name(fs_info, location);
1245 if (!root)
1246 return NULL;
1247
1248 if (root->in_sysfs)
1249 return root;
1250
1251 ret = btrfs_set_root_name(root, name, namelen);
1252 if (ret) {
1253 free_extent_buffer(root->node);
1254 kfree(root);
1255 return ERR_PTR(ret);
1256 }
1257 #if 0
1258 ret = btrfs_sysfs_add_root(root);
1259 if (ret) {
1260 free_extent_buffer(root->node);
1261 kfree(root->name);
1262 kfree(root);
1263 return ERR_PTR(ret);
1264 }
1265 #endif
1266 root->in_sysfs = 1;
1267 return root;
1268 }
1269
1270 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1271 {
1272 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1273 int ret = 0;
1274 struct btrfs_device *device;
1275 struct backing_dev_info *bdi;
1276 #if 0
1277 if ((bdi_bits & (1 << BDI_write_congested)) &&
1278 btrfs_congested_async(info, 0))
1279 return 1;
1280 #endif
1281 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1282 if (!device->bdev)
1283 continue;
1284 bdi = blk_get_backing_dev_info(device->bdev);
1285 if (bdi && bdi_congested(bdi, bdi_bits)) {
1286 ret = 1;
1287 break;
1288 }
1289 }
1290 return ret;
1291 }
1292
1293 /*
1294 * this unplugs every device on the box, and it is only used when page
1295 * is null
1296 */
1297 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1298 {
1299 struct btrfs_device *device;
1300 struct btrfs_fs_info *info;
1301
1302 info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1303 list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
1304 if (!device->bdev)
1305 continue;
1306
1307 bdi = blk_get_backing_dev_info(device->bdev);
1308 if (bdi->unplug_io_fn)
1309 bdi->unplug_io_fn(bdi, page);
1310 }
1311 }
1312
1313 static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1314 {
1315 struct inode *inode;
1316 struct extent_map_tree *em_tree;
1317 struct extent_map *em;
1318 struct address_space *mapping;
1319 u64 offset;
1320
1321 /* the generic O_DIRECT read code does this */
1322 if (1 || !page) {
1323 __unplug_io_fn(bdi, page);
1324 return;
1325 }
1326
1327 /*
1328 * page->mapping may change at any time. Get a consistent copy
1329 * and use that for everything below
1330 */
1331 smp_mb();
1332 mapping = page->mapping;
1333 if (!mapping)
1334 return;
1335
1336 inode = mapping->host;
1337
1338 /*
1339 * don't do the expensive searching for a small number of
1340 * devices
1341 */
1342 if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
1343 __unplug_io_fn(bdi, page);
1344 return;
1345 }
1346
1347 offset = page_offset(page);
1348
1349 em_tree = &BTRFS_I(inode)->extent_tree;
1350 spin_lock(&em_tree->lock);
1351 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1352 spin_unlock(&em_tree->lock);
1353 if (!em) {
1354 __unplug_io_fn(bdi, page);
1355 return;
1356 }
1357
1358 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1359 free_extent_map(em);
1360 __unplug_io_fn(bdi, page);
1361 return;
1362 }
1363 offset = offset - em->start;
1364 btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1365 em->block_start + offset, page);
1366 free_extent_map(em);
1367 }
1368
1369 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1370 {
1371 bdi_init(bdi);
1372 bdi->ra_pages = default_backing_dev_info.ra_pages;
1373 bdi->state = 0;
1374 bdi->capabilities = default_backing_dev_info.capabilities;
1375 bdi->unplug_io_fn = btrfs_unplug_io_fn;
1376 bdi->unplug_io_data = info;
1377 bdi->congested_fn = btrfs_congested_fn;
1378 bdi->congested_data = info;
1379 return 0;
1380 }
1381
1382 static int bio_ready_for_csum(struct bio *bio)
1383 {
1384 u64 length = 0;
1385 u64 buf_len = 0;
1386 u64 start = 0;
1387 struct page *page;
1388 struct extent_io_tree *io_tree = NULL;
1389 struct btrfs_fs_info *info = NULL;
1390 struct bio_vec *bvec;
1391 int i;
1392 int ret;
1393
1394 bio_for_each_segment(bvec, bio, i) {
1395 page = bvec->bv_page;
1396 if (page->private == EXTENT_PAGE_PRIVATE) {
1397 length += bvec->bv_len;
1398 continue;
1399 }
1400 if (!page->private) {
1401 length += bvec->bv_len;
1402 continue;
1403 }
1404 length = bvec->bv_len;
1405 buf_len = page->private >> 2;
1406 start = page_offset(page) + bvec->bv_offset;
1407 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1408 info = BTRFS_I(page->mapping->host)->root->fs_info;
1409 }
1410 /* are we fully contained in this bio? */
1411 if (buf_len <= length)
1412 return 1;
1413
1414 ret = extent_range_uptodate(io_tree, start + length,
1415 start + buf_len - 1);
1416 return ret;
1417 }
1418
1419 /*
1420 * called by the kthread helper functions to finally call the bio end_io
1421 * functions. This is where read checksum verification actually happens
1422 */
1423 static void end_workqueue_fn(struct btrfs_work *work)
1424 {
1425 struct bio *bio;
1426 struct end_io_wq *end_io_wq;
1427 struct btrfs_fs_info *fs_info;
1428 int error;
1429
1430 end_io_wq = container_of(work, struct end_io_wq, work);
1431 bio = end_io_wq->bio;
1432 fs_info = end_io_wq->info;
1433
1434 /* metadata bio reads are special because the whole tree block must
1435 * be checksummed at once. This makes sure the entire block is in
1436 * ram and up to date before trying to verify things. For
1437 * blocksize <= pagesize, it is basically a noop
1438 */
1439 if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
1440 !bio_ready_for_csum(bio)) {
1441 btrfs_queue_worker(&fs_info->endio_meta_workers,
1442 &end_io_wq->work);
1443 return;
1444 }
1445 error = end_io_wq->error;
1446 bio->bi_private = end_io_wq->private;
1447 bio->bi_end_io = end_io_wq->end_io;
1448 kfree(end_io_wq);
1449 bio_endio(bio, error);
1450 }
1451
1452 static int cleaner_kthread(void *arg)
1453 {
1454 struct btrfs_root *root = arg;
1455
1456 do {
1457 smp_mb();
1458 if (root->fs_info->closing)
1459 break;
1460
1461 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1462 mutex_lock(&root->fs_info->cleaner_mutex);
1463 btrfs_clean_old_snapshots(root);
1464 mutex_unlock(&root->fs_info->cleaner_mutex);
1465
1466 if (freezing(current)) {
1467 refrigerator();
1468 } else {
1469 smp_mb();
1470 if (root->fs_info->closing)
1471 break;
1472 set_current_state(TASK_INTERRUPTIBLE);
1473 schedule();
1474 __set_current_state(TASK_RUNNING);
1475 }
1476 } while (!kthread_should_stop());
1477 return 0;
1478 }
1479
1480 static int transaction_kthread(void *arg)
1481 {
1482 struct btrfs_root *root = arg;
1483 struct btrfs_trans_handle *trans;
1484 struct btrfs_transaction *cur;
1485 unsigned long now;
1486 unsigned long delay;
1487 int ret;
1488
1489 do {
1490 smp_mb();
1491 if (root->fs_info->closing)
1492 break;
1493
1494 delay = HZ * 30;
1495 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1496 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1497
1498 mutex_lock(&root->fs_info->trans_mutex);
1499 cur = root->fs_info->running_transaction;
1500 if (!cur) {
1501 mutex_unlock(&root->fs_info->trans_mutex);
1502 goto sleep;
1503 }
1504
1505 now = get_seconds();
1506 if (now < cur->start_time || now - cur->start_time < 30) {
1507 mutex_unlock(&root->fs_info->trans_mutex);
1508 delay = HZ * 5;
1509 goto sleep;
1510 }
1511 mutex_unlock(&root->fs_info->trans_mutex);
1512 trans = btrfs_start_transaction(root, 1);
1513 ret = btrfs_commit_transaction(trans, root);
1514
1515 sleep:
1516 wake_up_process(root->fs_info->cleaner_kthread);
1517 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1518
1519 if (freezing(current)) {
1520 refrigerator();
1521 } else {
1522 if (root->fs_info->closing)
1523 break;
1524 set_current_state(TASK_INTERRUPTIBLE);
1525 schedule_timeout(delay);
1526 __set_current_state(TASK_RUNNING);
1527 }
1528 } while (!kthread_should_stop());
1529 return 0;
1530 }
1531
1532 struct btrfs_root *open_ctree(struct super_block *sb,
1533 struct btrfs_fs_devices *fs_devices,
1534 char *options)
1535 {
1536 u32 sectorsize;
1537 u32 nodesize;
1538 u32 leafsize;
1539 u32 blocksize;
1540 u32 stripesize;
1541 u64 generation;
1542 u64 features;
1543 struct btrfs_key location;
1544 struct buffer_head *bh;
1545 struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1546 GFP_NOFS);
1547 struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1548 GFP_NOFS);
1549 struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1550 GFP_NOFS);
1551 struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1552 GFP_NOFS);
1553 struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1554 GFP_NOFS);
1555 struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1556 GFP_NOFS);
1557 struct btrfs_root *log_tree_root;
1558
1559 int ret;
1560 int err = -EINVAL;
1561
1562 struct btrfs_super_block *disk_super;
1563
1564 if (!extent_root || !tree_root || !fs_info ||
1565 !chunk_root || !dev_root || !csum_root) {
1566 err = -ENOMEM;
1567 goto fail;
1568 }
1569 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1570 INIT_LIST_HEAD(&fs_info->trans_list);
1571 INIT_LIST_HEAD(&fs_info->dead_roots);
1572 INIT_LIST_HEAD(&fs_info->hashers);
1573 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1574 INIT_LIST_HEAD(&fs_info->ordered_operations);
1575 spin_lock_init(&fs_info->delalloc_lock);
1576 spin_lock_init(&fs_info->new_trans_lock);
1577 spin_lock_init(&fs_info->ref_cache_lock);
1578
1579 init_completion(&fs_info->kobj_unregister);
1580 fs_info->tree_root = tree_root;
1581 fs_info->extent_root = extent_root;
1582 fs_info->csum_root = csum_root;
1583 fs_info->chunk_root = chunk_root;
1584 fs_info->dev_root = dev_root;
1585 fs_info->fs_devices = fs_devices;
1586 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1587 INIT_LIST_HEAD(&fs_info->space_info);
1588 btrfs_mapping_init(&fs_info->mapping_tree);
1589 atomic_set(&fs_info->nr_async_submits, 0);
1590 atomic_set(&fs_info->async_delalloc_pages, 0);
1591 atomic_set(&fs_info->async_submit_draining, 0);
1592 atomic_set(&fs_info->nr_async_bios, 0);
1593 atomic_set(&fs_info->throttles, 0);
1594 atomic_set(&fs_info->throttle_gen, 0);
1595 fs_info->sb = sb;
1596 fs_info->max_extent = (u64)-1;
1597 fs_info->max_inline = 8192 * 1024;
1598 setup_bdi(fs_info, &fs_info->bdi);
1599 fs_info->btree_inode = new_inode(sb);
1600 fs_info->btree_inode->i_ino = 1;
1601 fs_info->btree_inode->i_nlink = 1;
1602
1603 fs_info->thread_pool_size = min_t(unsigned long,
1604 num_online_cpus() + 2, 8);
1605
1606 INIT_LIST_HEAD(&fs_info->ordered_extents);
1607 spin_lock_init(&fs_info->ordered_extent_lock);
1608
1609 sb->s_blocksize = 4096;
1610 sb->s_blocksize_bits = blksize_bits(4096);
1611
1612 /*
1613 * we set the i_size on the btree inode to the max possible int.
1614 * the real end of the address space is determined by all of
1615 * the devices in the system
1616 */
1617 fs_info->btree_inode->i_size = OFFSET_MAX;
1618 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1619 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1620
1621 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1622 fs_info->btree_inode->i_mapping,
1623 GFP_NOFS);
1624 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1625 GFP_NOFS);
1626
1627 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1628
1629 spin_lock_init(&fs_info->block_group_cache_lock);
1630 fs_info->block_group_cache_tree.rb_node = NULL;
1631
1632 extent_io_tree_init(&fs_info->pinned_extents,
1633 fs_info->btree_inode->i_mapping, GFP_NOFS);
1634 fs_info->do_barriers = 1;
1635
1636 INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1637 btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1638 btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1639
1640 BTRFS_I(fs_info->btree_inode)->root = tree_root;
1641 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1642 sizeof(struct btrfs_key));
1643 insert_inode_hash(fs_info->btree_inode);
1644
1645 mutex_init(&fs_info->trans_mutex);
1646 mutex_init(&fs_info->ordered_operations_mutex);
1647 mutex_init(&fs_info->tree_log_mutex);
1648 mutex_init(&fs_info->drop_mutex);
1649 mutex_init(&fs_info->chunk_mutex);
1650 mutex_init(&fs_info->transaction_kthread_mutex);
1651 mutex_init(&fs_info->cleaner_mutex);
1652 mutex_init(&fs_info->volume_mutex);
1653 mutex_init(&fs_info->tree_reloc_mutex);
1654
1655 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1656 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1657
1658 init_waitqueue_head(&fs_info->transaction_throttle);
1659 init_waitqueue_head(&fs_info->transaction_wait);
1660 init_waitqueue_head(&fs_info->async_submit_wait);
1661
1662 __setup_root(4096, 4096, 4096, 4096, tree_root,
1663 fs_info, BTRFS_ROOT_TREE_OBJECTID);
1664
1665
1666 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1667 if (!bh)
1668 goto fail_iput;
1669
1670 memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1671 memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1672 sizeof(fs_info->super_for_commit));
1673 brelse(bh);
1674
1675 memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1676
1677 disk_super = &fs_info->super_copy;
1678 if (!btrfs_super_root(disk_super))
1679 goto fail_iput;
1680
1681 ret = btrfs_parse_options(tree_root, options);
1682 if (ret) {
1683 err = ret;
1684 goto fail_iput;
1685 }
1686
1687 features = btrfs_super_incompat_flags(disk_super) &
1688 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1689 if (features) {
1690 printk(KERN_ERR "BTRFS: couldn't mount because of "
1691 "unsupported optional features (%Lx).\n",
1692 features);
1693 err = -EINVAL;
1694 goto fail_iput;
1695 }
1696
1697 features = btrfs_super_compat_ro_flags(disk_super) &
1698 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1699 if (!(sb->s_flags & MS_RDONLY) && features) {
1700 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1701 "unsupported option features (%Lx).\n",
1702 features);
1703 err = -EINVAL;
1704 goto fail_iput;
1705 }
1706
1707 /*
1708 * we need to start all the end_io workers up front because the
1709 * queue work function gets called at interrupt time, and so it
1710 * cannot dynamically grow.
1711 */
1712 btrfs_init_workers(&fs_info->workers, "worker",
1713 fs_info->thread_pool_size);
1714
1715 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1716 fs_info->thread_pool_size);
1717
1718 btrfs_init_workers(&fs_info->submit_workers, "submit",
1719 min_t(u64, fs_devices->num_devices,
1720 fs_info->thread_pool_size));
1721
1722 /* a higher idle thresh on the submit workers makes it much more
1723 * likely that bios will be send down in a sane order to the
1724 * devices
1725 */
1726 fs_info->submit_workers.idle_thresh = 64;
1727
1728 fs_info->workers.idle_thresh = 16;
1729 fs_info->workers.ordered = 1;
1730
1731 fs_info->delalloc_workers.idle_thresh = 2;
1732 fs_info->delalloc_workers.ordered = 1;
1733
1734 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1735 btrfs_init_workers(&fs_info->endio_workers, "endio",
1736 fs_info->thread_pool_size);
1737 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1738 fs_info->thread_pool_size);
1739 btrfs_init_workers(&fs_info->endio_meta_write_workers,
1740 "endio-meta-write", fs_info->thread_pool_size);
1741 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1742 fs_info->thread_pool_size);
1743
1744 /*
1745 * endios are largely parallel and should have a very
1746 * low idle thresh
1747 */
1748 fs_info->endio_workers.idle_thresh = 4;
1749 fs_info->endio_meta_workers.idle_thresh = 4;
1750
1751 fs_info->endio_write_workers.idle_thresh = 64;
1752 fs_info->endio_meta_write_workers.idle_thresh = 64;
1753
1754 btrfs_start_workers(&fs_info->workers, 1);
1755 btrfs_start_workers(&fs_info->submit_workers, 1);
1756 btrfs_start_workers(&fs_info->delalloc_workers, 1);
1757 btrfs_start_workers(&fs_info->fixup_workers, 1);
1758 btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1759 btrfs_start_workers(&fs_info->endio_meta_workers,
1760 fs_info->thread_pool_size);
1761 btrfs_start_workers(&fs_info->endio_meta_write_workers,
1762 fs_info->thread_pool_size);
1763 btrfs_start_workers(&fs_info->endio_write_workers,
1764 fs_info->thread_pool_size);
1765
1766 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1767 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1768 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1769
1770 nodesize = btrfs_super_nodesize(disk_super);
1771 leafsize = btrfs_super_leafsize(disk_super);
1772 sectorsize = btrfs_super_sectorsize(disk_super);
1773 stripesize = btrfs_super_stripesize(disk_super);
1774 tree_root->nodesize = nodesize;
1775 tree_root->leafsize = leafsize;
1776 tree_root->sectorsize = sectorsize;
1777 tree_root->stripesize = stripesize;
1778
1779 sb->s_blocksize = sectorsize;
1780 sb->s_blocksize_bits = blksize_bits(sectorsize);
1781
1782 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1783 sizeof(disk_super->magic))) {
1784 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1785 goto fail_sb_buffer;
1786 }
1787
1788 mutex_lock(&fs_info->chunk_mutex);
1789 ret = btrfs_read_sys_array(tree_root);
1790 mutex_unlock(&fs_info->chunk_mutex);
1791 if (ret) {
1792 printk(KERN_WARNING "btrfs: failed to read the system "
1793 "array on %s\n", sb->s_id);
1794 goto fail_sys_array;
1795 }
1796
1797 blocksize = btrfs_level_size(tree_root,
1798 btrfs_super_chunk_root_level(disk_super));
1799 generation = btrfs_super_chunk_root_generation(disk_super);
1800
1801 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1802 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1803
1804 chunk_root->node = read_tree_block(chunk_root,
1805 btrfs_super_chunk_root(disk_super),
1806 blocksize, generation);
1807 BUG_ON(!chunk_root->node);
1808
1809 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1810 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1811 BTRFS_UUID_SIZE);
1812
1813 mutex_lock(&fs_info->chunk_mutex);
1814 ret = btrfs_read_chunk_tree(chunk_root);
1815 mutex_unlock(&fs_info->chunk_mutex);
1816 if (ret) {
1817 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1818 sb->s_id);
1819 goto fail_chunk_root;
1820 }
1821
1822 btrfs_close_extra_devices(fs_devices);
1823
1824 blocksize = btrfs_level_size(tree_root,
1825 btrfs_super_root_level(disk_super));
1826 generation = btrfs_super_generation(disk_super);
1827
1828 tree_root->node = read_tree_block(tree_root,
1829 btrfs_super_root(disk_super),
1830 blocksize, generation);
1831 if (!tree_root->node)
1832 goto fail_chunk_root;
1833
1834
1835 ret = find_and_setup_root(tree_root, fs_info,
1836 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1837 if (ret)
1838 goto fail_tree_root;
1839 extent_root->track_dirty = 1;
1840
1841 ret = find_and_setup_root(tree_root, fs_info,
1842 BTRFS_DEV_TREE_OBJECTID, dev_root);
1843 dev_root->track_dirty = 1;
1844 if (ret)
1845 goto fail_extent_root;
1846
1847 ret = find_and_setup_root(tree_root, fs_info,
1848 BTRFS_CSUM_TREE_OBJECTID, csum_root);
1849 if (ret)
1850 goto fail_extent_root;
1851
1852 csum_root->track_dirty = 1;
1853
1854 btrfs_read_block_groups(extent_root);
1855
1856 fs_info->generation = generation;
1857 fs_info->last_trans_committed = generation;
1858 fs_info->data_alloc_profile = (u64)-1;
1859 fs_info->metadata_alloc_profile = (u64)-1;
1860 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1861 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1862 "btrfs-cleaner");
1863 if (IS_ERR(fs_info->cleaner_kthread))
1864 goto fail_csum_root;
1865
1866 fs_info->transaction_kthread = kthread_run(transaction_kthread,
1867 tree_root,
1868 "btrfs-transaction");
1869 if (IS_ERR(fs_info->transaction_kthread))
1870 goto fail_cleaner;
1871
1872 if (btrfs_super_log_root(disk_super) != 0) {
1873 u64 bytenr = btrfs_super_log_root(disk_super);
1874
1875 if (fs_devices->rw_devices == 0) {
1876 printk(KERN_WARNING "Btrfs log replay required "
1877 "on RO media\n");
1878 err = -EIO;
1879 goto fail_trans_kthread;
1880 }
1881 blocksize =
1882 btrfs_level_size(tree_root,
1883 btrfs_super_log_root_level(disk_super));
1884
1885 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1886 GFP_NOFS);
1887
1888 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1889 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1890
1891 log_tree_root->node = read_tree_block(tree_root, bytenr,
1892 blocksize,
1893 generation + 1);
1894 ret = btrfs_recover_log_trees(log_tree_root);
1895 BUG_ON(ret);
1896
1897 if (sb->s_flags & MS_RDONLY) {
1898 ret = btrfs_commit_super(tree_root);
1899 BUG_ON(ret);
1900 }
1901 }
1902
1903 if (!(sb->s_flags & MS_RDONLY)) {
1904 ret = btrfs_cleanup_reloc_trees(tree_root);
1905 BUG_ON(ret);
1906 }
1907
1908 location.objectid = BTRFS_FS_TREE_OBJECTID;
1909 location.type = BTRFS_ROOT_ITEM_KEY;
1910 location.offset = (u64)-1;
1911
1912 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
1913 if (!fs_info->fs_root)
1914 goto fail_trans_kthread;
1915 return tree_root;
1916
1917 fail_trans_kthread:
1918 kthread_stop(fs_info->transaction_kthread);
1919 fail_cleaner:
1920 kthread_stop(fs_info->cleaner_kthread);
1921
1922 /*
1923 * make sure we're done with the btree inode before we stop our
1924 * kthreads
1925 */
1926 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1927 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1928
1929 fail_csum_root:
1930 free_extent_buffer(csum_root->node);
1931 fail_extent_root:
1932 free_extent_buffer(extent_root->node);
1933 fail_tree_root:
1934 free_extent_buffer(tree_root->node);
1935 fail_chunk_root:
1936 free_extent_buffer(chunk_root->node);
1937 fail_sys_array:
1938 free_extent_buffer(dev_root->node);
1939 fail_sb_buffer:
1940 btrfs_stop_workers(&fs_info->fixup_workers);
1941 btrfs_stop_workers(&fs_info->delalloc_workers);
1942 btrfs_stop_workers(&fs_info->workers);
1943 btrfs_stop_workers(&fs_info->endio_workers);
1944 btrfs_stop_workers(&fs_info->endio_meta_workers);
1945 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
1946 btrfs_stop_workers(&fs_info->endio_write_workers);
1947 btrfs_stop_workers(&fs_info->submit_workers);
1948 fail_iput:
1949 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
1950 iput(fs_info->btree_inode);
1951
1952 btrfs_close_devices(fs_info->fs_devices);
1953 btrfs_mapping_tree_free(&fs_info->mapping_tree);
1954 bdi_destroy(&fs_info->bdi);
1955
1956 fail:
1957 kfree(extent_root);
1958 kfree(tree_root);
1959 kfree(fs_info);
1960 kfree(chunk_root);
1961 kfree(dev_root);
1962 kfree(csum_root);
1963 return ERR_PTR(err);
1964 }
1965
1966 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1967 {
1968 char b[BDEVNAME_SIZE];
1969
1970 if (uptodate) {
1971 set_buffer_uptodate(bh);
1972 } else {
1973 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1974 printk(KERN_WARNING "lost page write due to "
1975 "I/O error on %s\n",
1976 bdevname(bh->b_bdev, b));
1977 }
1978 /* note, we dont' set_buffer_write_io_error because we have
1979 * our own ways of dealing with the IO errors
1980 */
1981 clear_buffer_uptodate(bh);
1982 }
1983 unlock_buffer(bh);
1984 put_bh(bh);
1985 }
1986
1987 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
1988 {
1989 struct buffer_head *bh;
1990 struct buffer_head *latest = NULL;
1991 struct btrfs_super_block *super;
1992 int i;
1993 u64 transid = 0;
1994 u64 bytenr;
1995
1996 /* we would like to check all the supers, but that would make
1997 * a btrfs mount succeed after a mkfs from a different FS.
1998 * So, we need to add a special mount option to scan for
1999 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2000 */
2001 for (i = 0; i < 1; i++) {
2002 bytenr = btrfs_sb_offset(i);
2003 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2004 break;
2005 bh = __bread(bdev, bytenr / 4096, 4096);
2006 if (!bh)
2007 continue;
2008
2009 super = (struct btrfs_super_block *)bh->b_data;
2010 if (btrfs_super_bytenr(super) != bytenr ||
2011 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2012 sizeof(super->magic))) {
2013 brelse(bh);
2014 continue;
2015 }
2016
2017 if (!latest || btrfs_super_generation(super) > transid) {
2018 brelse(latest);
2019 latest = bh;
2020 transid = btrfs_super_generation(super);
2021 } else {
2022 brelse(bh);
2023 }
2024 }
2025 return latest;
2026 }
2027
2028 static int write_dev_supers(struct btrfs_device *device,
2029 struct btrfs_super_block *sb,
2030 int do_barriers, int wait, int max_mirrors)
2031 {
2032 struct buffer_head *bh;
2033 int i;
2034 int ret;
2035 int errors = 0;
2036 u32 crc;
2037 u64 bytenr;
2038 int last_barrier = 0;
2039
2040 if (max_mirrors == 0)
2041 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2042
2043 /* make sure only the last submit_bh does a barrier */
2044 if (do_barriers) {
2045 for (i = 0; i < max_mirrors; i++) {
2046 bytenr = btrfs_sb_offset(i);
2047 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2048 device->total_bytes)
2049 break;
2050 last_barrier = i;
2051 }
2052 }
2053
2054 for (i = 0; i < max_mirrors; i++) {
2055 bytenr = btrfs_sb_offset(i);
2056 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2057 break;
2058
2059 if (wait) {
2060 bh = __find_get_block(device->bdev, bytenr / 4096,
2061 BTRFS_SUPER_INFO_SIZE);
2062 BUG_ON(!bh);
2063 brelse(bh);
2064 wait_on_buffer(bh);
2065 if (buffer_uptodate(bh)) {
2066 brelse(bh);
2067 continue;
2068 }
2069 } else {
2070 btrfs_set_super_bytenr(sb, bytenr);
2071
2072 crc = ~(u32)0;
2073 crc = btrfs_csum_data(NULL, (char *)sb +
2074 BTRFS_CSUM_SIZE, crc,
2075 BTRFS_SUPER_INFO_SIZE -
2076 BTRFS_CSUM_SIZE);
2077 btrfs_csum_final(crc, sb->csum);
2078
2079 bh = __getblk(device->bdev, bytenr / 4096,
2080 BTRFS_SUPER_INFO_SIZE);
2081 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2082
2083 set_buffer_uptodate(bh);
2084 get_bh(bh);
2085 lock_buffer(bh);
2086 bh->b_end_io = btrfs_end_buffer_write_sync;
2087 }
2088
2089 if (i == last_barrier && do_barriers && device->barriers) {
2090 ret = submit_bh(WRITE_BARRIER, bh);
2091 if (ret == -EOPNOTSUPP) {
2092 printk("btrfs: disabling barriers on dev %s\n",
2093 device->name);
2094 set_buffer_uptodate(bh);
2095 device->barriers = 0;
2096 get_bh(bh);
2097 lock_buffer(bh);
2098 ret = submit_bh(WRITE, bh);
2099 }
2100 } else {
2101 ret = submit_bh(WRITE, bh);
2102 }
2103
2104 if (!ret && wait) {
2105 wait_on_buffer(bh);
2106 if (!buffer_uptodate(bh))
2107 errors++;
2108 } else if (ret) {
2109 errors++;
2110 }
2111 if (wait)
2112 brelse(bh);
2113 }
2114 return errors < i ? 0 : -1;
2115 }
2116
2117 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2118 {
2119 struct list_head *head = &root->fs_info->fs_devices->devices;
2120 struct btrfs_device *dev;
2121 struct btrfs_super_block *sb;
2122 struct btrfs_dev_item *dev_item;
2123 int ret;
2124 int do_barriers;
2125 int max_errors;
2126 int total_errors = 0;
2127 u64 flags;
2128
2129 max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2130 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2131
2132 sb = &root->fs_info->super_for_commit;
2133 dev_item = &sb->dev_item;
2134 list_for_each_entry(dev, head, dev_list) {
2135 if (!dev->bdev) {
2136 total_errors++;
2137 continue;
2138 }
2139 if (!dev->in_fs_metadata || !dev->writeable)
2140 continue;
2141
2142 btrfs_set_stack_device_generation(dev_item, 0);
2143 btrfs_set_stack_device_type(dev_item, dev->type);
2144 btrfs_set_stack_device_id(dev_item, dev->devid);
2145 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2146 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2147 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2148 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2149 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2150 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2151 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2152
2153 flags = btrfs_super_flags(sb);
2154 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2155
2156 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2157 if (ret)
2158 total_errors++;
2159 }
2160 if (total_errors > max_errors) {
2161 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2162 total_errors);
2163 BUG();
2164 }
2165
2166 total_errors = 0;
2167 list_for_each_entry(dev, head, dev_list) {
2168 if (!dev->bdev)
2169 continue;
2170 if (!dev->in_fs_metadata || !dev->writeable)
2171 continue;
2172
2173 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2174 if (ret)
2175 total_errors++;
2176 }
2177 if (total_errors > max_errors) {
2178 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2179 total_errors);
2180 BUG();
2181 }
2182 return 0;
2183 }
2184
2185 int write_ctree_super(struct btrfs_trans_handle *trans,
2186 struct btrfs_root *root, int max_mirrors)
2187 {
2188 int ret;
2189
2190 ret = write_all_supers(root, max_mirrors);
2191 return ret;
2192 }
2193
2194 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2195 {
2196 radix_tree_delete(&fs_info->fs_roots_radix,
2197 (unsigned long)root->root_key.objectid);
2198 if (root->anon_super.s_dev) {
2199 down_write(&root->anon_super.s_umount);
2200 kill_anon_super(&root->anon_super);
2201 }
2202 if (root->node)
2203 free_extent_buffer(root->node);
2204 if (root->commit_root)
2205 free_extent_buffer(root->commit_root);
2206 kfree(root->name);
2207 kfree(root);
2208 return 0;
2209 }
2210
2211 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2212 {
2213 int ret;
2214 struct btrfs_root *gang[8];
2215 int i;
2216
2217 while (1) {
2218 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2219 (void **)gang, 0,
2220 ARRAY_SIZE(gang));
2221 if (!ret)
2222 break;
2223 for (i = 0; i < ret; i++)
2224 btrfs_free_fs_root(fs_info, gang[i]);
2225 }
2226 return 0;
2227 }
2228
2229 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2230 {
2231 u64 root_objectid = 0;
2232 struct btrfs_root *gang[8];
2233 int i;
2234 int ret;
2235
2236 while (1) {
2237 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2238 (void **)gang, root_objectid,
2239 ARRAY_SIZE(gang));
2240 if (!ret)
2241 break;
2242 for (i = 0; i < ret; i++) {
2243 root_objectid = gang[i]->root_key.objectid;
2244 ret = btrfs_find_dead_roots(fs_info->tree_root,
2245 root_objectid, gang[i]);
2246 BUG_ON(ret);
2247 btrfs_orphan_cleanup(gang[i]);
2248 }
2249 root_objectid++;
2250 }
2251 return 0;
2252 }
2253
2254 int btrfs_commit_super(struct btrfs_root *root)
2255 {
2256 struct btrfs_trans_handle *trans;
2257 int ret;
2258
2259 mutex_lock(&root->fs_info->cleaner_mutex);
2260 btrfs_clean_old_snapshots(root);
2261 mutex_unlock(&root->fs_info->cleaner_mutex);
2262 trans = btrfs_start_transaction(root, 1);
2263 ret = btrfs_commit_transaction(trans, root);
2264 BUG_ON(ret);
2265 /* run commit again to drop the original snapshot */
2266 trans = btrfs_start_transaction(root, 1);
2267 btrfs_commit_transaction(trans, root);
2268 ret = btrfs_write_and_wait_transaction(NULL, root);
2269 BUG_ON(ret);
2270
2271 ret = write_ctree_super(NULL, root, 0);
2272 return ret;
2273 }
2274
2275 int close_ctree(struct btrfs_root *root)
2276 {
2277 struct btrfs_fs_info *fs_info = root->fs_info;
2278 int ret;
2279
2280 fs_info->closing = 1;
2281 smp_mb();
2282
2283 kthread_stop(root->fs_info->transaction_kthread);
2284 kthread_stop(root->fs_info->cleaner_kthread);
2285
2286 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2287 ret = btrfs_commit_super(root);
2288 if (ret)
2289 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2290 }
2291
2292 if (fs_info->delalloc_bytes) {
2293 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2294 fs_info->delalloc_bytes);
2295 }
2296 if (fs_info->total_ref_cache_size) {
2297 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2298 (unsigned long long)fs_info->total_ref_cache_size);
2299 }
2300
2301 if (fs_info->extent_root->node)
2302 free_extent_buffer(fs_info->extent_root->node);
2303
2304 if (fs_info->tree_root->node)
2305 free_extent_buffer(fs_info->tree_root->node);
2306
2307 if (root->fs_info->chunk_root->node)
2308 free_extent_buffer(root->fs_info->chunk_root->node);
2309
2310 if (root->fs_info->dev_root->node)
2311 free_extent_buffer(root->fs_info->dev_root->node);
2312
2313 if (root->fs_info->csum_root->node)
2314 free_extent_buffer(root->fs_info->csum_root->node);
2315
2316 btrfs_free_block_groups(root->fs_info);
2317
2318 del_fs_roots(fs_info);
2319
2320 iput(fs_info->btree_inode);
2321
2322 btrfs_stop_workers(&fs_info->fixup_workers);
2323 btrfs_stop_workers(&fs_info->delalloc_workers);
2324 btrfs_stop_workers(&fs_info->workers);
2325 btrfs_stop_workers(&fs_info->endio_workers);
2326 btrfs_stop_workers(&fs_info->endio_meta_workers);
2327 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2328 btrfs_stop_workers(&fs_info->endio_write_workers);
2329 btrfs_stop_workers(&fs_info->submit_workers);
2330
2331 #if 0
2332 while (!list_empty(&fs_info->hashers)) {
2333 struct btrfs_hasher *hasher;
2334 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
2335 hashers);
2336 list_del(&hasher->hashers);
2337 crypto_free_hash(&fs_info->hash_tfm);
2338 kfree(hasher);
2339 }
2340 #endif
2341 btrfs_close_devices(fs_info->fs_devices);
2342 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2343
2344 bdi_destroy(&fs_info->bdi);
2345
2346 kfree(fs_info->extent_root);
2347 kfree(fs_info->tree_root);
2348 kfree(fs_info->chunk_root);
2349 kfree(fs_info->dev_root);
2350 kfree(fs_info->csum_root);
2351 return 0;
2352 }
2353
2354 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2355 {
2356 int ret;
2357 struct inode *btree_inode = buf->first_page->mapping->host;
2358
2359 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
2360 if (!ret)
2361 return ret;
2362
2363 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2364 parent_transid);
2365 return !ret;
2366 }
2367
2368 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2369 {
2370 struct inode *btree_inode = buf->first_page->mapping->host;
2371 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2372 buf);
2373 }
2374
2375 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2376 {
2377 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2378 u64 transid = btrfs_header_generation(buf);
2379 struct inode *btree_inode = root->fs_info->btree_inode;
2380 int was_dirty;
2381
2382 btrfs_assert_tree_locked(buf);
2383 if (transid != root->fs_info->generation) {
2384 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2385 "found %llu running %llu\n",
2386 (unsigned long long)buf->start,
2387 (unsigned long long)transid,
2388 (unsigned long long)root->fs_info->generation);
2389 WARN_ON(1);
2390 }
2391 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2392 buf);
2393 if (!was_dirty) {
2394 spin_lock(&root->fs_info->delalloc_lock);
2395 root->fs_info->dirty_metadata_bytes += buf->len;
2396 spin_unlock(&root->fs_info->delalloc_lock);
2397 }
2398 }
2399
2400 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2401 {
2402 /*
2403 * looks as though older kernels can get into trouble with
2404 * this code, they end up stuck in balance_dirty_pages forever
2405 */
2406 struct extent_io_tree *tree;
2407 u64 num_dirty;
2408 u64 start = 0;
2409 unsigned long thresh = 32 * 1024 * 1024;
2410 tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
2411
2412 if (current->flags & PF_MEMALLOC)
2413 return;
2414
2415 num_dirty = count_range_bits(tree, &start, (u64)-1,
2416 thresh, EXTENT_DIRTY);
2417 if (num_dirty > thresh) {
2418 balance_dirty_pages_ratelimited_nr(
2419 root->fs_info->btree_inode->i_mapping, 1);
2420 }
2421 return;
2422 }
2423
2424 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2425 {
2426 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2427 int ret;
2428 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2429 if (ret == 0)
2430 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2431 return ret;
2432 }
2433
2434 int btree_lock_page_hook(struct page *page)
2435 {
2436 struct inode *inode = page->mapping->host;
2437 struct btrfs_root *root = BTRFS_I(inode)->root;
2438 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2439 struct extent_buffer *eb;
2440 unsigned long len;
2441 u64 bytenr = page_offset(page);
2442
2443 if (page->private == EXTENT_PAGE_PRIVATE)
2444 goto out;
2445
2446 len = page->private >> 2;
2447 eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2448 if (!eb)
2449 goto out;
2450
2451 btrfs_tree_lock(eb);
2452 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2453
2454 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2455 spin_lock(&root->fs_info->delalloc_lock);
2456 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2457 root->fs_info->dirty_metadata_bytes -= eb->len;
2458 else
2459 WARN_ON(1);
2460 spin_unlock(&root->fs_info->delalloc_lock);
2461 }
2462
2463 btrfs_tree_unlock(eb);
2464 free_extent_buffer(eb);
2465 out:
2466 lock_page(page);
2467 return 0;
2468 }
2469
2470 static struct extent_io_ops btree_extent_io_ops = {
2471 .write_cache_pages_lock_hook = btree_lock_page_hook,
2472 .readpage_end_io_hook = btree_readpage_end_io_hook,
2473 .submit_bio_hook = btree_submit_bio_hook,
2474 /* note we're sharing with inode.c for the merge bio hook */
2475 .merge_bio_hook = btrfs_merge_bio_hook,
2476 };
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