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btrfs: btrfs_multi_bio replaced with btrfs_bio
[linux-2.6/btrfs-unstable.git] / fs / btrfs / scrub.c
blob97142a218f0a8907825e0388f0d1dd4f149893a9
1 /*
2 * Copyright (C) 2011 STRATO. 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/blkdev.h>
20 #include <linux/ratelimit.h>
21 #include "ctree.h"
22 #include "volumes.h"
23 #include "disk-io.h"
24 #include "ordered-data.h"
25 #include "transaction.h"
26 #include "backref.h"
27
28 /*
29 * This is only the first step towards a full-features scrub. It reads all
30 * extent and super block and verifies the checksums. In case a bad checksum
31 * is found or the extent cannot be read, good data will be written back if
32 * any can be found.
33 *
34 * Future enhancements:
35 * - To enhance the performance, better read-ahead strategies for the
36 * extent-tree can be employed.
37 * - In case an unrepairable extent is encountered, track which files are
38 * affected and report them
39 * - In case of a read error on files with nodatasum, map the file and read
40 * the extent to trigger a writeback of the good copy
41 * - track and record media errors, throw out bad devices
42 * - add a mode to also read unallocated space
43 * - make the prefetch cancellable
44 */
45
46 struct scrub_bio;
47 struct scrub_page;
48 struct scrub_dev;
49 static void scrub_bio_end_io(struct bio *bio, int err);
50 static void scrub_checksum(struct btrfs_work *work);
51 static int scrub_checksum_data(struct scrub_dev *sdev,
52 struct scrub_page *spag, void *buffer);
53 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
54 struct scrub_page *spag, u64 logical,
55 void *buffer);
56 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer);
57 static int scrub_fixup_check(struct scrub_bio *sbio, int ix);
58 static void scrub_fixup_end_io(struct bio *bio, int err);
59 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
60 struct page *page);
61 static void scrub_fixup(struct scrub_bio *sbio, int ix);
62
63 #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
64 #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
65
66 struct scrub_page {
67 u64 flags; /* extent flags */
68 u64 generation;
69 int mirror_num;
70 int have_csum;
71 u8 csum[BTRFS_CSUM_SIZE];
72 };
73
74 struct scrub_bio {
75 int index;
76 struct scrub_dev *sdev;
77 struct bio *bio;
78 int err;
79 u64 logical;
80 u64 physical;
81 struct scrub_page spag[SCRUB_PAGES_PER_BIO];
82 u64 count;
83 int next_free;
84 struct btrfs_work work;
85 };
86
87 struct scrub_dev {
88 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
89 struct btrfs_device *dev;
90 int first_free;
91 int curr;
92 atomic_t in_flight;
93 atomic_t fixup_cnt;
94 spinlock_t list_lock;
95 wait_queue_head_t list_wait;
96 u16 csum_size;
97 struct list_head csum_list;
98 atomic_t cancel_req;
99 int readonly;
100 /*
101 * statistics
102 */
103 struct btrfs_scrub_progress stat;
104 spinlock_t stat_lock;
105 };
106
107 struct scrub_fixup_nodatasum {
108 struct scrub_dev *sdev;
109 u64 logical;
110 struct btrfs_root *root;
111 struct btrfs_work work;
112 int mirror_num;
113 };
114
115 struct scrub_warning {
116 struct btrfs_path *path;
117 u64 extent_item_size;
118 char *scratch_buf;
119 char *msg_buf;
120 const char *errstr;
121 sector_t sector;
122 u64 logical;
123 struct btrfs_device *dev;
124 int msg_bufsize;
125 int scratch_bufsize;
126 };
127
128 static void scrub_free_csums(struct scrub_dev *sdev)
129 {
130 while (!list_empty(&sdev->csum_list)) {
131 struct btrfs_ordered_sum *sum;
132 sum = list_first_entry(&sdev->csum_list,
133 struct btrfs_ordered_sum, list);
134 list_del(&sum->list);
135 kfree(sum);
136 }
137 }
138
139 static void scrub_free_bio(struct bio *bio)
140 {
141 int i;
142 struct page *last_page = NULL;
143
144 if (!bio)
145 return;
146
147 for (i = 0; i < bio->bi_vcnt; ++i) {
148 if (bio->bi_io_vec[i].bv_page == last_page)
149 continue;
150 last_page = bio->bi_io_vec[i].bv_page;
151 __free_page(last_page);
152 }
153 bio_put(bio);
154 }
155
156 static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
157 {
158 int i;
159
160 if (!sdev)
161 return;
162
163 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
164 struct scrub_bio *sbio = sdev->bios[i];
165
166 if (!sbio)
167 break;
168
169 scrub_free_bio(sbio->bio);
170 kfree(sbio);
171 }
172
173 scrub_free_csums(sdev);
174 kfree(sdev);
175 }
176
177 static noinline_for_stack
178 struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
179 {
180 struct scrub_dev *sdev;
181 int i;
182 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
183
184 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
185 if (!sdev)
186 goto nomem;
187 sdev->dev = dev;
188 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
189 struct scrub_bio *sbio;
190
191 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
192 if (!sbio)
193 goto nomem;
194 sdev->bios[i] = sbio;
195
196 sbio->index = i;
197 sbio->sdev = sdev;
198 sbio->count = 0;
199 sbio->work.func = scrub_checksum;
200
201 if (i != SCRUB_BIOS_PER_DEV-1)
202 sdev->bios[i]->next_free = i + 1;
203 else
204 sdev->bios[i]->next_free = -1;
205 }
206 sdev->first_free = 0;
207 sdev->curr = -1;
208 atomic_set(&sdev->in_flight, 0);
209 atomic_set(&sdev->fixup_cnt, 0);
210 atomic_set(&sdev->cancel_req, 0);
211 sdev->csum_size = btrfs_super_csum_size(&fs_info->super_copy);
212 INIT_LIST_HEAD(&sdev->csum_list);
213
214 spin_lock_init(&sdev->list_lock);
215 spin_lock_init(&sdev->stat_lock);
216 init_waitqueue_head(&sdev->list_wait);
217 return sdev;
218
219 nomem:
220 scrub_free_dev(sdev);
221 return ERR_PTR(-ENOMEM);
222 }
223
224 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
225 {
226 u64 isize;
227 u32 nlink;
228 int ret;
229 int i;
230 struct extent_buffer *eb;
231 struct btrfs_inode_item *inode_item;
232 struct scrub_warning *swarn = ctx;
233 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
234 struct inode_fs_paths *ipath = NULL;
235 struct btrfs_root *local_root;
236 struct btrfs_key root_key;
237
238 root_key.objectid = root;
239 root_key.type = BTRFS_ROOT_ITEM_KEY;
240 root_key.offset = (u64)-1;
241 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
242 if (IS_ERR(local_root)) {
243 ret = PTR_ERR(local_root);
244 goto err;
245 }
246
247 ret = inode_item_info(inum, 0, local_root, swarn->path);
248 if (ret) {
249 btrfs_release_path(swarn->path);
250 goto err;
251 }
252
253 eb = swarn->path->nodes[0];
254 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
255 struct btrfs_inode_item);
256 isize = btrfs_inode_size(eb, inode_item);
257 nlink = btrfs_inode_nlink(eb, inode_item);
258 btrfs_release_path(swarn->path);
259
260 ipath = init_ipath(4096, local_root, swarn->path);
261 ret = paths_from_inode(inum, ipath);
262
263 if (ret < 0)
264 goto err;
265
266 /*
267 * we deliberately ignore the bit ipath might have been too small to
268 * hold all of the paths here
269 */
270 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
271 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
272 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
273 "length %llu, links %u (path: %s)\n", swarn->errstr,
274 swarn->logical, swarn->dev->name,
275 (unsigned long long)swarn->sector, root, inum, offset,
276 min(isize - offset, (u64)PAGE_SIZE), nlink,
277 ipath->fspath->str[i]);
278
279 free_ipath(ipath);
280 return 0;
281
282 err:
283 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
284 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
285 "resolving failed with ret=%d\n", swarn->errstr,
286 swarn->logical, swarn->dev->name,
287 (unsigned long long)swarn->sector, root, inum, offset, ret);
288
289 free_ipath(ipath);
290 return 0;
291 }
292
293 static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
294 int ix)
295 {
296 struct btrfs_device *dev = sbio->sdev->dev;
297 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
298 struct btrfs_path *path;
299 struct btrfs_key found_key;
300 struct extent_buffer *eb;
301 struct btrfs_extent_item *ei;
302 struct scrub_warning swarn;
303 u32 item_size;
304 int ret;
305 u64 ref_root;
306 u8 ref_level;
307 unsigned long ptr = 0;
308 const int bufsize = 4096;
309 u64 extent_offset;
310
311 path = btrfs_alloc_path();
312
313 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
314 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
315 swarn.sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
316 swarn.logical = sbio->logical + ix * PAGE_SIZE;
317 swarn.errstr = errstr;
318 swarn.dev = dev;
319 swarn.msg_bufsize = bufsize;
320 swarn.scratch_bufsize = bufsize;
321
322 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
323 goto out;
324
325 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
326 if (ret < 0)
327 goto out;
328
329 extent_offset = swarn.logical - found_key.objectid;
330 swarn.extent_item_size = found_key.offset;
331
332 eb = path->nodes[0];
333 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
334 item_size = btrfs_item_size_nr(eb, path->slots[0]);
335
336 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
337 do {
338 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
339 &ref_root, &ref_level);
340 printk(KERN_WARNING "%s at logical %llu on dev %s, "
341 "sector %llu: metadata %s (level %d) in tree "
342 "%llu\n", errstr, swarn.logical, dev->name,
343 (unsigned long long)swarn.sector,
344 ref_level ? "node" : "leaf",
345 ret < 0 ? -1 : ref_level,
346 ret < 0 ? -1 : ref_root);
347 } while (ret != 1);
348 } else {
349 swarn.path = path;
350 iterate_extent_inodes(fs_info, path, found_key.objectid,
351 extent_offset,
352 scrub_print_warning_inode, &swarn);
353 }
354
355 out:
356 btrfs_free_path(path);
357 kfree(swarn.scratch_buf);
358 kfree(swarn.msg_buf);
359 }
360
361 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
362 {
363 struct page *page;
364 unsigned long index;
365 struct scrub_fixup_nodatasum *fixup = ctx;
366 int ret;
367 int corrected;
368 struct btrfs_key key;
369 struct inode *inode;
370 u64 end = offset + PAGE_SIZE - 1;
371 struct btrfs_root *local_root;
372
373 key.objectid = root;
374 key.type = BTRFS_ROOT_ITEM_KEY;
375 key.offset = (u64)-1;
376 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
377 if (IS_ERR(local_root))
378 return PTR_ERR(local_root);
379
380 key.type = BTRFS_INODE_ITEM_KEY;
381 key.objectid = inum;
382 key.offset = 0;
383 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
384 if (IS_ERR(inode))
385 return PTR_ERR(inode);
386
387 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, offset, end,
388 EXTENT_DAMAGED, 0, NULL, NULL, GFP_NOFS);
389
390 /* set_extent_bit should either succeed or give proper error */
391 WARN_ON(ret > 0);
392 if (ret)
393 return ret < 0 ? ret : -EFAULT;
394
395 index = offset >> PAGE_CACHE_SHIFT;
396
397 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
398 if (!page)
399 return -ENOMEM;
400
401 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
402 btrfs_get_extent, fixup->mirror_num);
403 wait_on_page_locked(page);
404 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset, end,
405 EXTENT_DAMAGED, 0, NULL);
406
407 if (corrected)
408 WARN_ON(!PageUptodate(page));
409 else
410 clear_extent_bit(&BTRFS_I(inode)->io_tree, offset, end,
411 EXTENT_DAMAGED, 0, 0, NULL, GFP_NOFS);
412
413 put_page(page);
414 iput(inode);
415
416 if (ret < 0)
417 return ret;
418
419 if (ret == 0 && corrected) {
420 /*
421 * we only need to call readpage for one of the inodes belonging
422 * to this extent. so make iterate_extent_inodes stop
423 */
424 return 1;
425 }
426
427 return -EIO;
428 }
429
430 static void scrub_fixup_nodatasum(struct btrfs_work *work)
431 {
432 int ret;
433 struct scrub_fixup_nodatasum *fixup;
434 struct scrub_dev *sdev;
435 struct btrfs_trans_handle *trans = NULL;
436 struct btrfs_fs_info *fs_info;
437 struct btrfs_path *path;
438 int uncorrectable = 0;
439
440 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
441 sdev = fixup->sdev;
442 fs_info = fixup->root->fs_info;
443
444 path = btrfs_alloc_path();
445 if (!path) {
446 spin_lock(&sdev->stat_lock);
447 ++sdev->stat.malloc_errors;
448 spin_unlock(&sdev->stat_lock);
449 uncorrectable = 1;
450 goto out;
451 }
452
453 trans = btrfs_join_transaction(fixup->root);
454 if (IS_ERR(trans)) {
455 uncorrectable = 1;
456 goto out;
457 }
458
459 /*
460 * the idea is to trigger a regular read through the standard path. we
461 * read a page from the (failed) logical address by specifying the
462 * corresponding copynum of the failed sector. thus, that readpage is
463 * expected to fail.
464 * that is the point where on-the-fly error correction will kick in
465 * (once it's finished) and rewrite the failed sector if a good copy
466 * can be found.
467 */
468 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
469 path, scrub_fixup_readpage,
470 fixup);
471 if (ret < 0) {
472 uncorrectable = 1;
473 goto out;
474 }
475 WARN_ON(ret != 1);
476
477 spin_lock(&sdev->stat_lock);
478 ++sdev->stat.corrected_errors;
479 spin_unlock(&sdev->stat_lock);
480
481 out:
482 if (trans && !IS_ERR(trans))
483 btrfs_end_transaction(trans, fixup->root);
484 if (uncorrectable) {
485 spin_lock(&sdev->stat_lock);
486 ++sdev->stat.uncorrectable_errors;
487 spin_unlock(&sdev->stat_lock);
488 printk_ratelimited(KERN_ERR "btrfs: unable to fixup "
489 "(nodatasum) error at logical %llu\n",
490 fixup->logical);
491 }
492
493 btrfs_free_path(path);
494 kfree(fixup);
495
496 /* see caller why we're pretending to be paused in the scrub counters */
497 mutex_lock(&fs_info->scrub_lock);
498 atomic_dec(&fs_info->scrubs_running);
499 atomic_dec(&fs_info->scrubs_paused);
500 mutex_unlock(&fs_info->scrub_lock);
501 atomic_dec(&sdev->fixup_cnt);
502 wake_up(&fs_info->scrub_pause_wait);
503 wake_up(&sdev->list_wait);
504 }
505
506 /*
507 * scrub_recheck_error gets called when either verification of the page
508 * failed or the bio failed to read, e.g. with EIO. In the latter case,
509 * recheck_error gets called for every page in the bio, even though only
510 * one may be bad
511 */
512 static int scrub_recheck_error(struct scrub_bio *sbio, int ix)
513 {
514 struct scrub_dev *sdev = sbio->sdev;
515 u64 sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
516 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
517 DEFAULT_RATELIMIT_BURST);
518
519 if (sbio->err) {
520 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev, sector,
521 sbio->bio->bi_io_vec[ix].bv_page) == 0) {
522 if (scrub_fixup_check(sbio, ix) == 0)
523 return 0;
524 }
525 if (__ratelimit(&_rs))
526 scrub_print_warning("i/o error", sbio, ix);
527 } else {
528 if (__ratelimit(&_rs))
529 scrub_print_warning("checksum error", sbio, ix);
530 }
531
532 spin_lock(&sdev->stat_lock);
533 ++sdev->stat.read_errors;
534 spin_unlock(&sdev->stat_lock);
535
536 scrub_fixup(sbio, ix);
537 return 1;
538 }
539
540 static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
541 {
542 int ret = 1;
543 struct page *page;
544 void *buffer;
545 u64 flags = sbio->spag[ix].flags;
546
547 page = sbio->bio->bi_io_vec[ix].bv_page;
548 buffer = kmap_atomic(page, KM_USER0);
549 if (flags & BTRFS_EXTENT_FLAG_DATA) {
550 ret = scrub_checksum_data(sbio->sdev,
551 sbio->spag + ix, buffer);
552 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
553 ret = scrub_checksum_tree_block(sbio->sdev,
554 sbio->spag + ix,
555 sbio->logical + ix * PAGE_SIZE,
556 buffer);
557 } else {
558 WARN_ON(1);
559 }
560 kunmap_atomic(buffer, KM_USER0);
561
562 return ret;
563 }
564
565 static void scrub_fixup_end_io(struct bio *bio, int err)
566 {
567 complete((struct completion *)bio->bi_private);
568 }
569
570 static void scrub_fixup(struct scrub_bio *sbio, int ix)
571 {
572 struct scrub_dev *sdev = sbio->sdev;
573 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
574 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
575 struct btrfs_bio *bbio = NULL;
576 struct scrub_fixup_nodatasum *fixup;
577 u64 logical = sbio->logical + ix * PAGE_SIZE;
578 u64 length;
579 int i;
580 int ret;
581 DECLARE_COMPLETION_ONSTACK(complete);
582
583 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
584 (sbio->spag[ix].have_csum == 0)) {
585 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
586 if (!fixup)
587 goto uncorrectable;
588 fixup->sdev = sdev;
589 fixup->logical = logical;
590 fixup->root = fs_info->extent_root;
591 fixup->mirror_num = sbio->spag[ix].mirror_num;
592 /*
593 * increment scrubs_running to prevent cancel requests from
594 * completing as long as a fixup worker is running. we must also
595 * increment scrubs_paused to prevent deadlocking on pause
596 * requests used for transactions commits (as the worker uses a
597 * transaction context). it is safe to regard the fixup worker
598 * as paused for all matters practical. effectively, we only
599 * avoid cancellation requests from completing.
600 */
601 mutex_lock(&fs_info->scrub_lock);
602 atomic_inc(&fs_info->scrubs_running);
603 atomic_inc(&fs_info->scrubs_paused);
604 mutex_unlock(&fs_info->scrub_lock);
605 atomic_inc(&sdev->fixup_cnt);
606 fixup->work.func = scrub_fixup_nodatasum;
607 btrfs_queue_worker(&fs_info->scrub_workers, &fixup->work);
608 return;
609 }
610
611 length = PAGE_SIZE;
612 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
613 &bbio, 0);
614 if (ret || !bbio || length < PAGE_SIZE) {
615 printk(KERN_ERR
616 "scrub_fixup: btrfs_map_block failed us for %llu\n",
617 (unsigned long long)logical);
618 WARN_ON(1);
619 return;
620 }
621
622 if (bbio->num_stripes == 1)
623 /* there aren't any replicas */
624 goto uncorrectable;
625
626 /*
627 * first find a good copy
628 */
629 for (i = 0; i < bbio->num_stripes; ++i) {
630 if (i + 1 == sbio->spag[ix].mirror_num)
631 continue;
632
633 if (scrub_fixup_io(READ, bbio->stripes[i].dev->bdev,
634 bbio->stripes[i].physical >> 9,
635 sbio->bio->bi_io_vec[ix].bv_page)) {
636 /* I/O-error, this is not a good copy */
637 continue;
638 }
639
640 if (scrub_fixup_check(sbio, ix) == 0)
641 break;
642 }
643 if (i == bbio->num_stripes)
644 goto uncorrectable;
645
646 if (!sdev->readonly) {
647 /*
648 * bi_io_vec[ix].bv_page now contains good data, write it back
649 */
650 if (scrub_fixup_io(WRITE, sdev->dev->bdev,
651 (sbio->physical + ix * PAGE_SIZE) >> 9,
652 sbio->bio->bi_io_vec[ix].bv_page)) {
653 /* I/O-error, writeback failed, give up */
654 goto uncorrectable;
655 }
656 }
657
658 kfree(bbio);
659 spin_lock(&sdev->stat_lock);
660 ++sdev->stat.corrected_errors;
661 spin_unlock(&sdev->stat_lock);
662
663 printk_ratelimited(KERN_ERR "btrfs: fixed up error at logical %llu\n",
664 (unsigned long long)logical);
665 return;
666
667 uncorrectable:
668 kfree(bbio);
669 spin_lock(&sdev->stat_lock);
670 ++sdev->stat.uncorrectable_errors;
671 spin_unlock(&sdev->stat_lock);
672
673 printk_ratelimited(KERN_ERR "btrfs: unable to fixup (regular) error at "
674 "logical %llu\n", (unsigned long long)logical);
675 }
676
677 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
678 struct page *page)
679 {
680 struct bio *bio = NULL;
681 int ret;
682 DECLARE_COMPLETION_ONSTACK(complete);
683
684 bio = bio_alloc(GFP_NOFS, 1);
685 bio->bi_bdev = bdev;
686 bio->bi_sector = sector;
687 bio_add_page(bio, page, PAGE_SIZE, 0);
688 bio->bi_end_io = scrub_fixup_end_io;
689 bio->bi_private = &complete;
690 submit_bio(rw, bio);
691
692 /* this will also unplug the queue */
693 wait_for_completion(&complete);
694
695 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
696 bio_put(bio);
697 return ret;
698 }
699
700 static void scrub_bio_end_io(struct bio *bio, int err)
701 {
702 struct scrub_bio *sbio = bio->bi_private;
703 struct scrub_dev *sdev = sbio->sdev;
704 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
705
706 sbio->err = err;
707 sbio->bio = bio;
708
709 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
710 }
711
712 static void scrub_checksum(struct btrfs_work *work)
713 {
714 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
715 struct scrub_dev *sdev = sbio->sdev;
716 struct page *page;
717 void *buffer;
718 int i;
719 u64 flags;
720 u64 logical;
721 int ret;
722
723 if (sbio->err) {
724 ret = 0;
725 for (i = 0; i < sbio->count; ++i)
726 ret |= scrub_recheck_error(sbio, i);
727 if (!ret) {
728 spin_lock(&sdev->stat_lock);
729 ++sdev->stat.unverified_errors;
730 spin_unlock(&sdev->stat_lock);
731 }
732
733 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
734 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
735 sbio->bio->bi_phys_segments = 0;
736 sbio->bio->bi_idx = 0;
737
738 for (i = 0; i < sbio->count; i++) {
739 struct bio_vec *bi;
740 bi = &sbio->bio->bi_io_vec[i];
741 bi->bv_offset = 0;
742 bi->bv_len = PAGE_SIZE;
743 }
744 goto out;
745 }
746 for (i = 0; i < sbio->count; ++i) {
747 page = sbio->bio->bi_io_vec[i].bv_page;
748 buffer = kmap_atomic(page, KM_USER0);
749 flags = sbio->spag[i].flags;
750 logical = sbio->logical + i * PAGE_SIZE;
751 ret = 0;
752 if (flags & BTRFS_EXTENT_FLAG_DATA) {
753 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer);
754 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
755 ret = scrub_checksum_tree_block(sdev, sbio->spag + i,
756 logical, buffer);
757 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) {
758 BUG_ON(i);
759 (void)scrub_checksum_super(sbio, buffer);
760 } else {
761 WARN_ON(1);
762 }
763 kunmap_atomic(buffer, KM_USER0);
764 if (ret) {
765 ret = scrub_recheck_error(sbio, i);
766 if (!ret) {
767 spin_lock(&sdev->stat_lock);
768 ++sdev->stat.unverified_errors;
769 spin_unlock(&sdev->stat_lock);
770 }
771 }
772 }
773
774 out:
775 scrub_free_bio(sbio->bio);
776 sbio->bio = NULL;
777 spin_lock(&sdev->list_lock);
778 sbio->next_free = sdev->first_free;
779 sdev->first_free = sbio->index;
780 spin_unlock(&sdev->list_lock);
781 atomic_dec(&sdev->in_flight);
782 wake_up(&sdev->list_wait);
783 }
784
785 static int scrub_checksum_data(struct scrub_dev *sdev,
786 struct scrub_page *spag, void *buffer)
787 {
788 u8 csum[BTRFS_CSUM_SIZE];
789 u32 crc = ~(u32)0;
790 int fail = 0;
791 struct btrfs_root *root = sdev->dev->dev_root;
792
793 if (!spag->have_csum)
794 return 0;
795
796 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE);
797 btrfs_csum_final(crc, csum);
798 if (memcmp(csum, spag->csum, sdev->csum_size))
799 fail = 1;
800
801 spin_lock(&sdev->stat_lock);
802 ++sdev->stat.data_extents_scrubbed;
803 sdev->stat.data_bytes_scrubbed += PAGE_SIZE;
804 if (fail)
805 ++sdev->stat.csum_errors;
806 spin_unlock(&sdev->stat_lock);
807
808 return fail;
809 }
810
811 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
812 struct scrub_page *spag, u64 logical,
813 void *buffer)
814 {
815 struct btrfs_header *h;
816 struct btrfs_root *root = sdev->dev->dev_root;
817 struct btrfs_fs_info *fs_info = root->fs_info;
818 u8 csum[BTRFS_CSUM_SIZE];
819 u32 crc = ~(u32)0;
820 int fail = 0;
821 int crc_fail = 0;
822
823 /*
824 * we don't use the getter functions here, as we
825 * a) don't have an extent buffer and
826 * b) the page is already kmapped
827 */
828 h = (struct btrfs_header *)buffer;
829
830 if (logical != le64_to_cpu(h->bytenr))
831 ++fail;
832
833 if (spag->generation != le64_to_cpu(h->generation))
834 ++fail;
835
836 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
837 ++fail;
838
839 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
840 BTRFS_UUID_SIZE))
841 ++fail;
842
843 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
844 PAGE_SIZE - BTRFS_CSUM_SIZE);
845 btrfs_csum_final(crc, csum);
846 if (memcmp(csum, h->csum, sdev->csum_size))
847 ++crc_fail;
848
849 spin_lock(&sdev->stat_lock);
850 ++sdev->stat.tree_extents_scrubbed;
851 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE;
852 if (crc_fail)
853 ++sdev->stat.csum_errors;
854 if (fail)
855 ++sdev->stat.verify_errors;
856 spin_unlock(&sdev->stat_lock);
857
858 return fail || crc_fail;
859 }
860
861 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
862 {
863 struct btrfs_super_block *s;
864 u64 logical;
865 struct scrub_dev *sdev = sbio->sdev;
866 struct btrfs_root *root = sdev->dev->dev_root;
867 struct btrfs_fs_info *fs_info = root->fs_info;
868 u8 csum[BTRFS_CSUM_SIZE];
869 u32 crc = ~(u32)0;
870 int fail = 0;
871
872 s = (struct btrfs_super_block *)buffer;
873 logical = sbio->logical;
874
875 if (logical != le64_to_cpu(s->bytenr))
876 ++fail;
877
878 if (sbio->spag[0].generation != le64_to_cpu(s->generation))
879 ++fail;
880
881 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
882 ++fail;
883
884 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
885 PAGE_SIZE - BTRFS_CSUM_SIZE);
886 btrfs_csum_final(crc, csum);
887 if (memcmp(csum, s->csum, sbio->sdev->csum_size))
888 ++fail;
889
890 if (fail) {
891 /*
892 * if we find an error in a super block, we just report it.
893 * They will get written with the next transaction commit
894 * anyway
895 */
896 spin_lock(&sdev->stat_lock);
897 ++sdev->stat.super_errors;
898 spin_unlock(&sdev->stat_lock);
899 }
900
901 return fail;
902 }
903
904 static int scrub_submit(struct scrub_dev *sdev)
905 {
906 struct scrub_bio *sbio;
907 struct bio *bio;
908 int i;
909
910 if (sdev->curr == -1)
911 return 0;
912
913 sbio = sdev->bios[sdev->curr];
914
915 bio = bio_alloc(GFP_NOFS, sbio->count);
916 if (!bio)
917 goto nomem;
918
919 bio->bi_private = sbio;
920 bio->bi_end_io = scrub_bio_end_io;
921 bio->bi_bdev = sdev->dev->bdev;
922 bio->bi_sector = sbio->physical >> 9;
923
924 for (i = 0; i < sbio->count; ++i) {
925 struct page *page;
926 int ret;
927
928 page = alloc_page(GFP_NOFS);
929 if (!page)
930 goto nomem;
931
932 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
933 if (!ret) {
934 __free_page(page);
935 goto nomem;
936 }
937 }
938
939 sbio->err = 0;
940 sdev->curr = -1;
941 atomic_inc(&sdev->in_flight);
942
943 submit_bio(READ, bio);
944
945 return 0;
946
947 nomem:
948 scrub_free_bio(bio);
949
950 return -ENOMEM;
951 }
952
953 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
954 u64 physical, u64 flags, u64 gen, int mirror_num,
955 u8 *csum, int force)
956 {
957 struct scrub_bio *sbio;
958
959 again:
960 /*
961 * grab a fresh bio or wait for one to become available
962 */
963 while (sdev->curr == -1) {
964 spin_lock(&sdev->list_lock);
965 sdev->curr = sdev->first_free;
966 if (sdev->curr != -1) {
967 sdev->first_free = sdev->bios[sdev->curr]->next_free;
968 sdev->bios[sdev->curr]->next_free = -1;
969 sdev->bios[sdev->curr]->count = 0;
970 spin_unlock(&sdev->list_lock);
971 } else {
972 spin_unlock(&sdev->list_lock);
973 wait_event(sdev->list_wait, sdev->first_free != -1);
974 }
975 }
976 sbio = sdev->bios[sdev->curr];
977 if (sbio->count == 0) {
978 sbio->physical = physical;
979 sbio->logical = logical;
980 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
981 sbio->logical + sbio->count * PAGE_SIZE != logical) {
982 int ret;
983
984 ret = scrub_submit(sdev);
985 if (ret)
986 return ret;
987 goto again;
988 }
989 sbio->spag[sbio->count].flags = flags;
990 sbio->spag[sbio->count].generation = gen;
991 sbio->spag[sbio->count].have_csum = 0;
992 sbio->spag[sbio->count].mirror_num = mirror_num;
993 if (csum) {
994 sbio->spag[sbio->count].have_csum = 1;
995 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
996 }
997 ++sbio->count;
998 if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
999 int ret;
1000
1001 ret = scrub_submit(sdev);
1002 if (ret)
1003 return ret;
1004 }
1005
1006 return 0;
1007 }
1008
1009 static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
1010 u8 *csum)
1011 {
1012 struct btrfs_ordered_sum *sum = NULL;
1013 int ret = 0;
1014 unsigned long i;
1015 unsigned long num_sectors;
1016 u32 sectorsize = sdev->dev->dev_root->sectorsize;
1017
1018 while (!list_empty(&sdev->csum_list)) {
1019 sum = list_first_entry(&sdev->csum_list,
1020 struct btrfs_ordered_sum, list);
1021 if (sum->bytenr > logical)
1022 return 0;
1023 if (sum->bytenr + sum->len > logical)
1024 break;
1025
1026 ++sdev->stat.csum_discards;
1027 list_del(&sum->list);
1028 kfree(sum);
1029 sum = NULL;
1030 }
1031 if (!sum)
1032 return 0;
1033
1034 num_sectors = sum->len / sectorsize;
1035 for (i = 0; i < num_sectors; ++i) {
1036 if (sum->sums[i].bytenr == logical) {
1037 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
1038 ret = 1;
1039 break;
1040 }
1041 }
1042 if (ret && i == num_sectors - 1) {
1043 list_del(&sum->list);
1044 kfree(sum);
1045 }
1046 return ret;
1047 }
1048
1049 /* scrub extent tries to collect up to 64 kB for each bio */
1050 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
1051 u64 physical, u64 flags, u64 gen, int mirror_num)
1052 {
1053 int ret;
1054 u8 csum[BTRFS_CSUM_SIZE];
1055
1056 while (len) {
1057 u64 l = min_t(u64, len, PAGE_SIZE);
1058 int have_csum = 0;
1059
1060 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1061 /* push csums to sbio */
1062 have_csum = scrub_find_csum(sdev, logical, l, csum);
1063 if (have_csum == 0)
1064 ++sdev->stat.no_csum;
1065 }
1066 ret = scrub_page(sdev, logical, l, physical, flags, gen,
1067 mirror_num, have_csum ? csum : NULL, 0);
1068 if (ret)
1069 return ret;
1070 len -= l;
1071 logical += l;
1072 physical += l;
1073 }
1074 return 0;
1075 }
1076
1077 static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
1078 struct map_lookup *map, int num, u64 base, u64 length)
1079 {
1080 struct btrfs_path *path;
1081 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1082 struct btrfs_root *root = fs_info->extent_root;
1083 struct btrfs_root *csum_root = fs_info->csum_root;
1084 struct btrfs_extent_item *extent;
1085 struct blk_plug plug;
1086 u64 flags;
1087 int ret;
1088 int slot;
1089 int i;
1090 u64 nstripes;
1091 int start_stripe;
1092 struct extent_buffer *l;
1093 struct btrfs_key key;
1094 u64 physical;
1095 u64 logical;
1096 u64 generation;
1097 int mirror_num;
1098
1099 u64 increment = map->stripe_len;
1100 u64 offset;
1101
1102 nstripes = length;
1103 offset = 0;
1104 do_div(nstripes, map->stripe_len);
1105 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1106 offset = map->stripe_len * num;
1107 increment = map->stripe_len * map->num_stripes;
1108 mirror_num = 1;
1109 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1110 int factor = map->num_stripes / map->sub_stripes;
1111 offset = map->stripe_len * (num / map->sub_stripes);
1112 increment = map->stripe_len * factor;
1113 mirror_num = num % map->sub_stripes + 1;
1114 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1115 increment = map->stripe_len;
1116 mirror_num = num % map->num_stripes + 1;
1117 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1118 increment = map->stripe_len;
1119 mirror_num = num % map->num_stripes + 1;
1120 } else {
1121 increment = map->stripe_len;
1122 mirror_num = 1;
1123 }
1124
1125 path = btrfs_alloc_path();
1126 if (!path)
1127 return -ENOMEM;
1128
1129 path->reada = 2;
1130 path->search_commit_root = 1;
1131 path->skip_locking = 1;
1132
1133 /*
1134 * find all extents for each stripe and just read them to get
1135 * them into the page cache
1136 * FIXME: we can do better. build a more intelligent prefetching
1137 */
1138 logical = base + offset;
1139 physical = map->stripes[num].physical;
1140 ret = 0;
1141 for (i = 0; i < nstripes; ++i) {
1142 key.objectid = logical;
1143 key.type = BTRFS_EXTENT_ITEM_KEY;
1144 key.offset = (u64)0;
1145
1146 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1147 if (ret < 0)
1148 goto out_noplug;
1149
1150 /*
1151 * we might miss half an extent here, but that doesn't matter,
1152 * as it's only the prefetch
1153 */
1154 while (1) {
1155 l = path->nodes[0];
1156 slot = path->slots[0];
1157 if (slot >= btrfs_header_nritems(l)) {
1158 ret = btrfs_next_leaf(root, path);
1159 if (ret == 0)
1160 continue;
1161 if (ret < 0)
1162 goto out_noplug;
1163
1164 break;
1165 }
1166 btrfs_item_key_to_cpu(l, &key, slot);
1167
1168 if (key.objectid >= logical + map->stripe_len)
1169 break;
1170
1171 path->slots[0]++;
1172 }
1173 btrfs_release_path(path);
1174 logical += increment;
1175 physical += map->stripe_len;
1176 cond_resched();
1177 }
1178
1179 /*
1180 * collect all data csums for the stripe to avoid seeking during
1181 * the scrub. This might currently (crc32) end up to be about 1MB
1182 */
1183 start_stripe = 0;
1184 blk_start_plug(&plug);
1185 again:
1186 logical = base + offset + start_stripe * increment;
1187 for (i = start_stripe; i < nstripes; ++i) {
1188 ret = btrfs_lookup_csums_range(csum_root, logical,
1189 logical + map->stripe_len - 1,
1190 &sdev->csum_list, 1);
1191 if (ret)
1192 goto out;
1193
1194 logical += increment;
1195 cond_resched();
1196 }
1197 /*
1198 * now find all extents for each stripe and scrub them
1199 */
1200 logical = base + offset + start_stripe * increment;
1201 physical = map->stripes[num].physical + start_stripe * map->stripe_len;
1202 ret = 0;
1203 for (i = start_stripe; i < nstripes; ++i) {
1204 /*
1205 * canceled?
1206 */
1207 if (atomic_read(&fs_info->scrub_cancel_req) ||
1208 atomic_read(&sdev->cancel_req)) {
1209 ret = -ECANCELED;
1210 goto out;
1211 }
1212 /*
1213 * check to see if we have to pause
1214 */
1215 if (atomic_read(&fs_info->scrub_pause_req)) {
1216 /* push queued extents */
1217 scrub_submit(sdev);
1218 wait_event(sdev->list_wait,
1219 atomic_read(&sdev->in_flight) == 0);
1220 atomic_inc(&fs_info->scrubs_paused);
1221 wake_up(&fs_info->scrub_pause_wait);
1222 mutex_lock(&fs_info->scrub_lock);
1223 while (atomic_read(&fs_info->scrub_pause_req)) {
1224 mutex_unlock(&fs_info->scrub_lock);
1225 wait_event(fs_info->scrub_pause_wait,
1226 atomic_read(&fs_info->scrub_pause_req) == 0);
1227 mutex_lock(&fs_info->scrub_lock);
1228 }
1229 atomic_dec(&fs_info->scrubs_paused);
1230 mutex_unlock(&fs_info->scrub_lock);
1231 wake_up(&fs_info->scrub_pause_wait);
1232 scrub_free_csums(sdev);
1233 start_stripe = i;
1234 goto again;
1235 }
1236
1237 key.objectid = logical;
1238 key.type = BTRFS_EXTENT_ITEM_KEY;
1239 key.offset = (u64)0;
1240
1241 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1242 if (ret < 0)
1243 goto out;
1244 if (ret > 0) {
1245 ret = btrfs_previous_item(root, path, 0,
1246 BTRFS_EXTENT_ITEM_KEY);
1247 if (ret < 0)
1248 goto out;
1249 if (ret > 0) {
1250 /* there's no smaller item, so stick with the
1251 * larger one */
1252 btrfs_release_path(path);
1253 ret = btrfs_search_slot(NULL, root, &key,
1254 path, 0, 0);
1255 if (ret < 0)
1256 goto out;
1257 }
1258 }
1259
1260 while (1) {
1261 l = path->nodes[0];
1262 slot = path->slots[0];
1263 if (slot >= btrfs_header_nritems(l)) {
1264 ret = btrfs_next_leaf(root, path);
1265 if (ret == 0)
1266 continue;
1267 if (ret < 0)
1268 goto out;
1269
1270 break;
1271 }
1272 btrfs_item_key_to_cpu(l, &key, slot);
1273
1274 if (key.objectid + key.offset <= logical)
1275 goto next;
1276
1277 if (key.objectid >= logical + map->stripe_len)
1278 break;
1279
1280 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1281 goto next;
1282
1283 extent = btrfs_item_ptr(l, slot,
1284 struct btrfs_extent_item);
1285 flags = btrfs_extent_flags(l, extent);
1286 generation = btrfs_extent_generation(l, extent);
1287
1288 if (key.objectid < logical &&
1289 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1290 printk(KERN_ERR
1291 "btrfs scrub: tree block %llu spanning "
1292 "stripes, ignored. logical=%llu\n",
1293 (unsigned long long)key.objectid,
1294 (unsigned long long)logical);
1295 goto next;
1296 }
1297
1298 /*
1299 * trim extent to this stripe
1300 */
1301 if (key.objectid < logical) {
1302 key.offset -= logical - key.objectid;
1303 key.objectid = logical;
1304 }
1305 if (key.objectid + key.offset >
1306 logical + map->stripe_len) {
1307 key.offset = logical + map->stripe_len -
1308 key.objectid;
1309 }
1310
1311 ret = scrub_extent(sdev, key.objectid, key.offset,
1312 key.objectid - logical + physical,
1313 flags, generation, mirror_num);
1314 if (ret)
1315 goto out;
1316
1317 next:
1318 path->slots[0]++;
1319 }
1320 btrfs_release_path(path);
1321 logical += increment;
1322 physical += map->stripe_len;
1323 spin_lock(&sdev->stat_lock);
1324 sdev->stat.last_physical = physical;
1325 spin_unlock(&sdev->stat_lock);
1326 }
1327 /* push queued extents */
1328 scrub_submit(sdev);
1329
1330 out:
1331 blk_finish_plug(&plug);
1332 out_noplug:
1333 btrfs_free_path(path);
1334 return ret < 0 ? ret : 0;
1335 }
1336
1337 static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
1338 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length)
1339 {
1340 struct btrfs_mapping_tree *map_tree =
1341 &sdev->dev->dev_root->fs_info->mapping_tree;
1342 struct map_lookup *map;
1343 struct extent_map *em;
1344 int i;
1345 int ret = -EINVAL;
1346
1347 read_lock(&map_tree->map_tree.lock);
1348 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
1349 read_unlock(&map_tree->map_tree.lock);
1350
1351 if (!em)
1352 return -EINVAL;
1353
1354 map = (struct map_lookup *)em->bdev;
1355 if (em->start != chunk_offset)
1356 goto out;
1357
1358 if (em->len < length)
1359 goto out;
1360
1361 for (i = 0; i < map->num_stripes; ++i) {
1362 if (map->stripes[i].dev == sdev->dev) {
1363 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
1364 if (ret)
1365 goto out;
1366 }
1367 }
1368 out:
1369 free_extent_map(em);
1370
1371 return ret;
1372 }
1373
1374 static noinline_for_stack
1375 int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
1376 {
1377 struct btrfs_dev_extent *dev_extent = NULL;
1378 struct btrfs_path *path;
1379 struct btrfs_root *root = sdev->dev->dev_root;
1380 struct btrfs_fs_info *fs_info = root->fs_info;
1381 u64 length;
1382 u64 chunk_tree;
1383 u64 chunk_objectid;
1384 u64 chunk_offset;
1385 int ret;
1386 int slot;
1387 struct extent_buffer *l;
1388 struct btrfs_key key;
1389 struct btrfs_key found_key;
1390 struct btrfs_block_group_cache *cache;
1391
1392 path = btrfs_alloc_path();
1393 if (!path)
1394 return -ENOMEM;
1395
1396 path->reada = 2;
1397 path->search_commit_root = 1;
1398 path->skip_locking = 1;
1399
1400 key.objectid = sdev->dev->devid;
1401 key.offset = 0ull;
1402 key.type = BTRFS_DEV_EXTENT_KEY;
1403
1404
1405 while (1) {
1406 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1407 if (ret < 0)
1408 break;
1409 if (ret > 0) {
1410 if (path->slots[0] >=
1411 btrfs_header_nritems(path->nodes[0])) {
1412 ret = btrfs_next_leaf(root, path);
1413 if (ret)
1414 break;
1415 }
1416 }
1417
1418 l = path->nodes[0];
1419 slot = path->slots[0];
1420
1421 btrfs_item_key_to_cpu(l, &found_key, slot);
1422
1423 if (found_key.objectid != sdev->dev->devid)
1424 break;
1425
1426 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
1427 break;
1428
1429 if (found_key.offset >= end)
1430 break;
1431
1432 if (found_key.offset < key.offset)
1433 break;
1434
1435 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1436 length = btrfs_dev_extent_length(l, dev_extent);
1437
1438 if (found_key.offset + length <= start) {
1439 key.offset = found_key.offset + length;
1440 btrfs_release_path(path);
1441 continue;
1442 }
1443
1444 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1445 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1446 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1447
1448 /*
1449 * get a reference on the corresponding block group to prevent
1450 * the chunk from going away while we scrub it
1451 */
1452 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
1453 if (!cache) {
1454 ret = -ENOENT;
1455 break;
1456 }
1457 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
1458 chunk_offset, length);
1459 btrfs_put_block_group(cache);
1460 if (ret)
1461 break;
1462
1463 key.offset = found_key.offset + length;
1464 btrfs_release_path(path);
1465 }
1466
1467 btrfs_free_path(path);
1468
1469 /*
1470 * ret can still be 1 from search_slot or next_leaf,
1471 * that's not an error
1472 */
1473 return ret < 0 ? ret : 0;
1474 }
1475
1476 static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
1477 {
1478 int i;
1479 u64 bytenr;
1480 u64 gen;
1481 int ret;
1482 struct btrfs_device *device = sdev->dev;
1483 struct btrfs_root *root = device->dev_root;
1484
1485 gen = root->fs_info->last_trans_committed;
1486
1487 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1488 bytenr = btrfs_sb_offset(i);
1489 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1490 break;
1491
1492 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr,
1493 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
1494 if (ret)
1495 return ret;
1496 }
1497 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1498
1499 return 0;
1500 }
1501
1502 /*
1503 * get a reference count on fs_info->scrub_workers. start worker if necessary
1504 */
1505 static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
1506 {
1507 struct btrfs_fs_info *fs_info = root->fs_info;
1508
1509 mutex_lock(&fs_info->scrub_lock);
1510 if (fs_info->scrub_workers_refcnt == 0) {
1511 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
1512 fs_info->thread_pool_size, &fs_info->generic_worker);
1513 fs_info->scrub_workers.idle_thresh = 4;
1514 btrfs_start_workers(&fs_info->scrub_workers, 1);
1515 }
1516 ++fs_info->scrub_workers_refcnt;
1517 mutex_unlock(&fs_info->scrub_lock);
1518
1519 return 0;
1520 }
1521
1522 static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
1523 {
1524 struct btrfs_fs_info *fs_info = root->fs_info;
1525
1526 mutex_lock(&fs_info->scrub_lock);
1527 if (--fs_info->scrub_workers_refcnt == 0)
1528 btrfs_stop_workers(&fs_info->scrub_workers);
1529 WARN_ON(fs_info->scrub_workers_refcnt < 0);
1530 mutex_unlock(&fs_info->scrub_lock);
1531 }
1532
1533
1534 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
1535 struct btrfs_scrub_progress *progress, int readonly)
1536 {
1537 struct scrub_dev *sdev;
1538 struct btrfs_fs_info *fs_info = root->fs_info;
1539 int ret;
1540 struct btrfs_device *dev;
1541
1542 if (btrfs_fs_closing(root->fs_info))
1543 return -EINVAL;
1544
1545 /*
1546 * check some assumptions
1547 */
1548 if (root->sectorsize != PAGE_SIZE ||
1549 root->sectorsize != root->leafsize ||
1550 root->sectorsize != root->nodesize) {
1551 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n");
1552 return -EINVAL;
1553 }
1554
1555 ret = scrub_workers_get(root);
1556 if (ret)
1557 return ret;
1558
1559 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1560 dev = btrfs_find_device(root, devid, NULL, NULL);
1561 if (!dev || dev->missing) {
1562 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1563 scrub_workers_put(root);
1564 return -ENODEV;
1565 }
1566 mutex_lock(&fs_info->scrub_lock);
1567
1568 if (!dev->in_fs_metadata) {
1569 mutex_unlock(&fs_info->scrub_lock);
1570 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1571 scrub_workers_put(root);
1572 return -ENODEV;
1573 }
1574
1575 if (dev->scrub_device) {
1576 mutex_unlock(&fs_info->scrub_lock);
1577 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1578 scrub_workers_put(root);
1579 return -EINPROGRESS;
1580 }
1581 sdev = scrub_setup_dev(dev);
1582 if (IS_ERR(sdev)) {
1583 mutex_unlock(&fs_info->scrub_lock);
1584 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1585 scrub_workers_put(root);
1586 return PTR_ERR(sdev);
1587 }
1588 sdev->readonly = readonly;
1589 dev->scrub_device = sdev;
1590
1591 atomic_inc(&fs_info->scrubs_running);
1592 mutex_unlock(&fs_info->scrub_lock);
1593 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1594
1595 down_read(&fs_info->scrub_super_lock);
1596 ret = scrub_supers(sdev);
1597 up_read(&fs_info->scrub_super_lock);
1598
1599 if (!ret)
1600 ret = scrub_enumerate_chunks(sdev, start, end);
1601
1602 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1603 atomic_dec(&fs_info->scrubs_running);
1604 wake_up(&fs_info->scrub_pause_wait);
1605
1606 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
1607
1608 if (progress)
1609 memcpy(progress, &sdev->stat, sizeof(*progress));
1610
1611 mutex_lock(&fs_info->scrub_lock);
1612 dev->scrub_device = NULL;
1613 mutex_unlock(&fs_info->scrub_lock);
1614
1615 scrub_free_dev(sdev);
1616 scrub_workers_put(root);
1617
1618 return ret;
1619 }
1620
1621 int btrfs_scrub_pause(struct btrfs_root *root)
1622 {
1623 struct btrfs_fs_info *fs_info = root->fs_info;
1624
1625 mutex_lock(&fs_info->scrub_lock);
1626 atomic_inc(&fs_info->scrub_pause_req);
1627 while (atomic_read(&fs_info->scrubs_paused) !=
1628 atomic_read(&fs_info->scrubs_running)) {
1629 mutex_unlock(&fs_info->scrub_lock);
1630 wait_event(fs_info->scrub_pause_wait,
1631 atomic_read(&fs_info->scrubs_paused) ==
1632 atomic_read(&fs_info->scrubs_running));
1633 mutex_lock(&fs_info->scrub_lock);
1634 }
1635 mutex_unlock(&fs_info->scrub_lock);
1636
1637 return 0;
1638 }
1639
1640 int btrfs_scrub_continue(struct btrfs_root *root)
1641 {
1642 struct btrfs_fs_info *fs_info = root->fs_info;
1643
1644 atomic_dec(&fs_info->scrub_pause_req);
1645 wake_up(&fs_info->scrub_pause_wait);
1646 return 0;
1647 }
1648
1649 int btrfs_scrub_pause_super(struct btrfs_root *root)
1650 {
1651 down_write(&root->fs_info->scrub_super_lock);
1652 return 0;
1653 }
1654
1655 int btrfs_scrub_continue_super(struct btrfs_root *root)
1656 {
1657 up_write(&root->fs_info->scrub_super_lock);
1658 return 0;
1659 }
1660
1661 int btrfs_scrub_cancel(struct btrfs_root *root)
1662 {
1663 struct btrfs_fs_info *fs_info = root->fs_info;
1664
1665 mutex_lock(&fs_info->scrub_lock);
1666 if (!atomic_read(&fs_info->scrubs_running)) {
1667 mutex_unlock(&fs_info->scrub_lock);
1668 return -ENOTCONN;
1669 }
1670
1671 atomic_inc(&fs_info->scrub_cancel_req);
1672 while (atomic_read(&fs_info->scrubs_running)) {
1673 mutex_unlock(&fs_info->scrub_lock);
1674 wait_event(fs_info->scrub_pause_wait,
1675 atomic_read(&fs_info->scrubs_running) == 0);
1676 mutex_lock(&fs_info->scrub_lock);
1677 }
1678 atomic_dec(&fs_info->scrub_cancel_req);
1679 mutex_unlock(&fs_info->scrub_lock);
1680
1681 return 0;
1682 }
1683
1684 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
1685 {
1686 struct btrfs_fs_info *fs_info = root->fs_info;
1687 struct scrub_dev *sdev;
1688
1689 mutex_lock(&fs_info->scrub_lock);
1690 sdev = dev->scrub_device;
1691 if (!sdev) {
1692 mutex_unlock(&fs_info->scrub_lock);
1693 return -ENOTCONN;
1694 }
1695 atomic_inc(&sdev->cancel_req);
1696 while (dev->scrub_device) {
1697 mutex_unlock(&fs_info->scrub_lock);
1698 wait_event(fs_info->scrub_pause_wait,
1699 dev->scrub_device == NULL);
1700 mutex_lock(&fs_info->scrub_lock);
1701 }
1702 mutex_unlock(&fs_info->scrub_lock);
1703
1704 return 0;
1705 }
1706 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
1707 {
1708 struct btrfs_fs_info *fs_info = root->fs_info;
1709 struct btrfs_device *dev;
1710 int ret;
1711
1712 /*
1713 * we have to hold the device_list_mutex here so the device
1714 * does not go away in cancel_dev. FIXME: find a better solution
1715 */
1716 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1717 dev = btrfs_find_device(root, devid, NULL, NULL);
1718 if (!dev) {
1719 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1720 return -ENODEV;
1721 }
1722 ret = btrfs_scrub_cancel_dev(root, dev);
1723 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1724
1725 return ret;
1726 }
1727
1728 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
1729 struct btrfs_scrub_progress *progress)
1730 {
1731 struct btrfs_device *dev;
1732 struct scrub_dev *sdev = NULL;
1733
1734 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1735 dev = btrfs_find_device(root, devid, NULL, NULL);
1736 if (dev)
1737 sdev = dev->scrub_device;
1738 if (sdev)
1739 memcpy(progress, &sdev->stat, sizeof(*progress));
1740 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1741
1742 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
1743 }
(deprecated) Btrfs devel tree