]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - fs/btrfs/scrub.c
projects / mirror_ubuntu-bionic-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into integration
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / scrub.c
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 #include "extent_io.h"
28
29 /*
30 * This is only the first step towards a full-features scrub. It reads all
31 * extent and super block and verifies the checksums. In case a bad checksum
32 * is found or the extent cannot be read, good data will be written back if
33 * any can be found.
34 *
35 * Future enhancements:
36 * - In case an unrepairable extent is encountered, track which files are
37 * affected and report them
38 * - In case of a read error on files with nodatasum, map the file and read
39 * the extent to trigger a writeback of the good copy
40 * - track and record media errors, throw out bad devices
41 * - add a mode to also read unallocated space
42 */
43
44 struct scrub_bio;
45 struct scrub_page;
46 struct scrub_dev;
47 static void scrub_bio_end_io(struct bio *bio, int err);
48 static void scrub_checksum(struct btrfs_work *work);
49 static int scrub_checksum_data(struct scrub_dev *sdev,
50 struct scrub_page *spag, void *buffer);
51 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
52 struct scrub_page *spag, u64 logical,
53 void *buffer);
54 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer);
55 static int scrub_fixup_check(struct scrub_bio *sbio, int ix);
56 static void scrub_fixup_end_io(struct bio *bio, int err);
57 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
58 struct page *page);
59 static void scrub_fixup(struct scrub_bio *sbio, int ix);
60
61 #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
62 #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
63
64 struct scrub_page {
65 u64 flags; /* extent flags */
66 u64 generation;
67 int mirror_num;
68 int have_csum;
69 u8 csum[BTRFS_CSUM_SIZE];
70 };
71
72 struct scrub_bio {
73 int index;
74 struct scrub_dev *sdev;
75 struct bio *bio;
76 int err;
77 u64 logical;
78 u64 physical;
79 struct scrub_page spag[SCRUB_PAGES_PER_BIO];
80 u64 count;
81 int next_free;
82 struct btrfs_work work;
83 };
84
85 struct scrub_dev {
86 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
87 struct btrfs_device *dev;
88 int first_free;
89 int curr;
90 atomic_t in_flight;
91 atomic_t fixup_cnt;
92 spinlock_t list_lock;
93 wait_queue_head_t list_wait;
94 u16 csum_size;
95 struct list_head csum_list;
96 atomic_t cancel_req;
97 int readonly;
98 /*
99 * statistics
100 */
101 struct btrfs_scrub_progress stat;
102 spinlock_t stat_lock;
103 };
104
105 struct scrub_fixup_nodatasum {
106 struct scrub_dev *sdev;
107 u64 logical;
108 struct btrfs_root *root;
109 struct btrfs_work work;
110 int mirror_num;
111 };
112
113 struct scrub_warning {
114 struct btrfs_path *path;
115 u64 extent_item_size;
116 char *scratch_buf;
117 char *msg_buf;
118 const char *errstr;
119 sector_t sector;
120 u64 logical;
121 struct btrfs_device *dev;
122 int msg_bufsize;
123 int scratch_bufsize;
124 };
125
126 static void scrub_free_csums(struct scrub_dev *sdev)
127 {
128 while (!list_empty(&sdev->csum_list)) {
129 struct btrfs_ordered_sum *sum;
130 sum = list_first_entry(&sdev->csum_list,
131 struct btrfs_ordered_sum, list);
132 list_del(&sum->list);
133 kfree(sum);
134 }
135 }
136
137 static void scrub_free_bio(struct bio *bio)
138 {
139 int i;
140 struct page *last_page = NULL;
141
142 if (!bio)
143 return;
144
145 for (i = 0; i < bio->bi_vcnt; ++i) {
146 if (bio->bi_io_vec[i].bv_page == last_page)
147 continue;
148 last_page = bio->bi_io_vec[i].bv_page;
149 __free_page(last_page);
150 }
151 bio_put(bio);
152 }
153
154 static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
155 {
156 int i;
157
158 if (!sdev)
159 return;
160
161 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
162 struct scrub_bio *sbio = sdev->bios[i];
163
164 if (!sbio)
165 break;
166
167 scrub_free_bio(sbio->bio);
168 kfree(sbio);
169 }
170
171 scrub_free_csums(sdev);
172 kfree(sdev);
173 }
174
175 static noinline_for_stack
176 struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
177 {
178 struct scrub_dev *sdev;
179 int i;
180 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
181
182 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
183 if (!sdev)
184 goto nomem;
185 sdev->dev = dev;
186 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
187 struct scrub_bio *sbio;
188
189 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
190 if (!sbio)
191 goto nomem;
192 sdev->bios[i] = sbio;
193
194 sbio->index = i;
195 sbio->sdev = sdev;
196 sbio->count = 0;
197 sbio->work.func = scrub_checksum;
198
199 if (i != SCRUB_BIOS_PER_DEV-1)
200 sdev->bios[i]->next_free = i + 1;
201 else
202 sdev->bios[i]->next_free = -1;
203 }
204 sdev->first_free = 0;
205 sdev->curr = -1;
206 atomic_set(&sdev->in_flight, 0);
207 atomic_set(&sdev->fixup_cnt, 0);
208 atomic_set(&sdev->cancel_req, 0);
209 sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
210 INIT_LIST_HEAD(&sdev->csum_list);
211
212 spin_lock_init(&sdev->list_lock);
213 spin_lock_init(&sdev->stat_lock);
214 init_waitqueue_head(&sdev->list_wait);
215 return sdev;
216
217 nomem:
218 scrub_free_dev(sdev);
219 return ERR_PTR(-ENOMEM);
220 }
221
222 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
223 {
224 u64 isize;
225 u32 nlink;
226 int ret;
227 int i;
228 struct extent_buffer *eb;
229 struct btrfs_inode_item *inode_item;
230 struct scrub_warning *swarn = ctx;
231 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
232 struct inode_fs_paths *ipath = NULL;
233 struct btrfs_root *local_root;
234 struct btrfs_key root_key;
235
236 root_key.objectid = root;
237 root_key.type = BTRFS_ROOT_ITEM_KEY;
238 root_key.offset = (u64)-1;
239 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
240 if (IS_ERR(local_root)) {
241 ret = PTR_ERR(local_root);
242 goto err;
243 }
244
245 ret = inode_item_info(inum, 0, local_root, swarn->path);
246 if (ret) {
247 btrfs_release_path(swarn->path);
248 goto err;
249 }
250
251 eb = swarn->path->nodes[0];
252 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
253 struct btrfs_inode_item);
254 isize = btrfs_inode_size(eb, inode_item);
255 nlink = btrfs_inode_nlink(eb, inode_item);
256 btrfs_release_path(swarn->path);
257
258 ipath = init_ipath(4096, local_root, swarn->path);
259 if (IS_ERR(ipath)) {
260 ret = PTR_ERR(ipath);
261 ipath = NULL;
262 goto err;
263 }
264 ret = paths_from_inode(inum, ipath);
265
266 if (ret < 0)
267 goto err;
268
269 /*
270 * we deliberately ignore the bit ipath might have been too small to
271 * hold all of the paths here
272 */
273 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
274 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
275 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
276 "length %llu, links %u (path: %s)\n", swarn->errstr,
277 swarn->logical, swarn->dev->name,
278 (unsigned long long)swarn->sector, root, inum, offset,
279 min(isize - offset, (u64)PAGE_SIZE), nlink,
280 (char *)(unsigned long)ipath->fspath->val[i]);
281
282 free_ipath(ipath);
283 return 0;
284
285 err:
286 printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
287 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
288 "resolving failed with ret=%d\n", swarn->errstr,
289 swarn->logical, swarn->dev->name,
290 (unsigned long long)swarn->sector, root, inum, offset, ret);
291
292 free_ipath(ipath);
293 return 0;
294 }
295
296 static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
297 int ix)
298 {
299 struct btrfs_device *dev = sbio->sdev->dev;
300 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
301 struct btrfs_path *path;
302 struct btrfs_key found_key;
303 struct extent_buffer *eb;
304 struct btrfs_extent_item *ei;
305 struct scrub_warning swarn;
306 u32 item_size;
307 int ret;
308 u64 ref_root;
309 u8 ref_level;
310 unsigned long ptr = 0;
311 const int bufsize = 4096;
312 u64 extent_item_pos;
313
314 path = btrfs_alloc_path();
315
316 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
317 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
318 swarn.sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
319 swarn.logical = sbio->logical + ix * PAGE_SIZE;
320 swarn.errstr = errstr;
321 swarn.dev = dev;
322 swarn.msg_bufsize = bufsize;
323 swarn.scratch_bufsize = bufsize;
324
325 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
326 goto out;
327
328 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
329 if (ret < 0)
330 goto out;
331
332 extent_item_pos = swarn.logical - found_key.objectid;
333 swarn.extent_item_size = found_key.offset;
334
335 eb = path->nodes[0];
336 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
337 item_size = btrfs_item_size_nr(eb, path->slots[0]);
338 btrfs_release_path(path);
339
340 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
341 do {
342 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
343 &ref_root, &ref_level);
344 printk(KERN_WARNING "%s at logical %llu on dev %s, "
345 "sector %llu: metadata %s (level %d) in tree "
346 "%llu\n", errstr, swarn.logical, dev->name,
347 (unsigned long long)swarn.sector,
348 ref_level ? "node" : "leaf",
349 ret < 0 ? -1 : ref_level,
350 ret < 0 ? -1 : ref_root);
351 } while (ret != 1);
352 } else {
353 swarn.path = path;
354 iterate_extent_inodes(fs_info, path, found_key.objectid,
355 extent_item_pos,
356 scrub_print_warning_inode, &swarn);
357 }
358
359 out:
360 btrfs_free_path(path);
361 kfree(swarn.scratch_buf);
362 kfree(swarn.msg_buf);
363 }
364
365 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
366 {
367 struct page *page = NULL;
368 unsigned long index;
369 struct scrub_fixup_nodatasum *fixup = ctx;
370 int ret;
371 int corrected = 0;
372 struct btrfs_key key;
373 struct inode *inode = NULL;
374 u64 end = offset + PAGE_SIZE - 1;
375 struct btrfs_root *local_root;
376
377 key.objectid = root;
378 key.type = BTRFS_ROOT_ITEM_KEY;
379 key.offset = (u64)-1;
380 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
381 if (IS_ERR(local_root))
382 return PTR_ERR(local_root);
383
384 key.type = BTRFS_INODE_ITEM_KEY;
385 key.objectid = inum;
386 key.offset = 0;
387 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
388 if (IS_ERR(inode))
389 return PTR_ERR(inode);
390
391 index = offset >> PAGE_CACHE_SHIFT;
392
393 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
394 if (!page) {
395 ret = -ENOMEM;
396 goto out;
397 }
398
399 if (PageUptodate(page)) {
400 struct btrfs_mapping_tree *map_tree;
401 if (PageDirty(page)) {
402 /*
403 * we need to write the data to the defect sector. the
404 * data that was in that sector is not in memory,
405 * because the page was modified. we must not write the
406 * modified page to that sector.
407 *
408 * TODO: what could be done here: wait for the delalloc
409 * runner to write out that page (might involve
410 * COW) and see whether the sector is still
411 * referenced afterwards.
412 *
413 * For the meantime, we'll treat this error
414 * incorrectable, although there is a chance that a
415 * later scrub will find the bad sector again and that
416 * there's no dirty page in memory, then.
417 */
418 ret = -EIO;
419 goto out;
420 }
421 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
422 ret = repair_io_failure(map_tree, offset, PAGE_SIZE,
423 fixup->logical, page,
424 fixup->mirror_num);
425 unlock_page(page);
426 corrected = !ret;
427 } else {
428 /*
429 * we need to get good data first. the general readpage path
430 * will call repair_io_failure for us, we just have to make
431 * sure we read the bad mirror.
432 */
433 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
434 EXTENT_DAMAGED, GFP_NOFS);
435 if (ret) {
436 /* set_extent_bits should give proper error */
437 WARN_ON(ret > 0);
438 if (ret > 0)
439 ret = -EFAULT;
440 goto out;
441 }
442
443 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
444 btrfs_get_extent,
445 fixup->mirror_num);
446 wait_on_page_locked(page);
447
448 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
449 end, EXTENT_DAMAGED, 0, NULL);
450 if (!corrected)
451 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
452 EXTENT_DAMAGED, GFP_NOFS);
453 }
454
455 out:
456 if (page)
457 put_page(page);
458 if (inode)
459 iput(inode);
460
461 if (ret < 0)
462 return ret;
463
464 if (ret == 0 && corrected) {
465 /*
466 * we only need to call readpage for one of the inodes belonging
467 * to this extent. so make iterate_extent_inodes stop
468 */
469 return 1;
470 }
471
472 return -EIO;
473 }
474
475 static void scrub_fixup_nodatasum(struct btrfs_work *work)
476 {
477 int ret;
478 struct scrub_fixup_nodatasum *fixup;
479 struct scrub_dev *sdev;
480 struct btrfs_trans_handle *trans = NULL;
481 struct btrfs_fs_info *fs_info;
482 struct btrfs_path *path;
483 int uncorrectable = 0;
484
485 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
486 sdev = fixup->sdev;
487 fs_info = fixup->root->fs_info;
488
489 path = btrfs_alloc_path();
490 if (!path) {
491 spin_lock(&sdev->stat_lock);
492 ++sdev->stat.malloc_errors;
493 spin_unlock(&sdev->stat_lock);
494 uncorrectable = 1;
495 goto out;
496 }
497
498 trans = btrfs_join_transaction(fixup->root);
499 if (IS_ERR(trans)) {
500 uncorrectable = 1;
501 goto out;
502 }
503
504 /*
505 * the idea is to trigger a regular read through the standard path. we
506 * read a page from the (failed) logical address by specifying the
507 * corresponding copynum of the failed sector. thus, that readpage is
508 * expected to fail.
509 * that is the point where on-the-fly error correction will kick in
510 * (once it's finished) and rewrite the failed sector if a good copy
511 * can be found.
512 */
513 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
514 path, scrub_fixup_readpage,
515 fixup);
516 if (ret < 0) {
517 uncorrectable = 1;
518 goto out;
519 }
520 WARN_ON(ret != 1);
521
522 spin_lock(&sdev->stat_lock);
523 ++sdev->stat.corrected_errors;
524 spin_unlock(&sdev->stat_lock);
525
526 out:
527 if (trans && !IS_ERR(trans))
528 btrfs_end_transaction(trans, fixup->root);
529 if (uncorrectable) {
530 spin_lock(&sdev->stat_lock);
531 ++sdev->stat.uncorrectable_errors;
532 spin_unlock(&sdev->stat_lock);
533 printk_ratelimited(KERN_ERR "btrfs: unable to fixup "
534 "(nodatasum) error at logical %llu\n",
535 fixup->logical);
536 }
537
538 btrfs_free_path(path);
539 kfree(fixup);
540
541 /* see caller why we're pretending to be paused in the scrub counters */
542 mutex_lock(&fs_info->scrub_lock);
543 atomic_dec(&fs_info->scrubs_running);
544 atomic_dec(&fs_info->scrubs_paused);
545 mutex_unlock(&fs_info->scrub_lock);
546 atomic_dec(&sdev->fixup_cnt);
547 wake_up(&fs_info->scrub_pause_wait);
548 wake_up(&sdev->list_wait);
549 }
550
551 /*
552 * scrub_recheck_error gets called when either verification of the page
553 * failed or the bio failed to read, e.g. with EIO. In the latter case,
554 * recheck_error gets called for every page in the bio, even though only
555 * one may be bad
556 */
557 static int scrub_recheck_error(struct scrub_bio *sbio, int ix)
558 {
559 struct scrub_dev *sdev = sbio->sdev;
560 u64 sector = (sbio->physical + ix * PAGE_SIZE) >> 9;
561 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
562 DEFAULT_RATELIMIT_BURST);
563
564 if (sbio->err) {
565 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev, sector,
566 sbio->bio->bi_io_vec[ix].bv_page) == 0) {
567 if (scrub_fixup_check(sbio, ix) == 0)
568 return 0;
569 }
570 if (__ratelimit(&_rs))
571 scrub_print_warning("i/o error", sbio, ix);
572 } else {
573 if (__ratelimit(&_rs))
574 scrub_print_warning("checksum error", sbio, ix);
575 }
576
577 spin_lock(&sdev->stat_lock);
578 ++sdev->stat.read_errors;
579 spin_unlock(&sdev->stat_lock);
580
581 scrub_fixup(sbio, ix);
582 return 1;
583 }
584
585 static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
586 {
587 int ret = 1;
588 struct page *page;
589 void *buffer;
590 u64 flags = sbio->spag[ix].flags;
591
592 page = sbio->bio->bi_io_vec[ix].bv_page;
593 buffer = kmap_atomic(page, KM_USER0);
594 if (flags & BTRFS_EXTENT_FLAG_DATA) {
595 ret = scrub_checksum_data(sbio->sdev,
596 sbio->spag + ix, buffer);
597 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
598 ret = scrub_checksum_tree_block(sbio->sdev,
599 sbio->spag + ix,
600 sbio->logical + ix * PAGE_SIZE,
601 buffer);
602 } else {
603 WARN_ON(1);
604 }
605 kunmap_atomic(buffer, KM_USER0);
606
607 return ret;
608 }
609
610 static void scrub_fixup_end_io(struct bio *bio, int err)
611 {
612 complete((struct completion *)bio->bi_private);
613 }
614
615 static void scrub_fixup(struct scrub_bio *sbio, int ix)
616 {
617 struct scrub_dev *sdev = sbio->sdev;
618 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
619 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
620 struct btrfs_bio *bbio = NULL;
621 struct scrub_fixup_nodatasum *fixup;
622 u64 logical = sbio->logical + ix * PAGE_SIZE;
623 u64 length;
624 int i;
625 int ret;
626 DECLARE_COMPLETION_ONSTACK(complete);
627
628 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
629 (sbio->spag[ix].have_csum == 0)) {
630 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
631 if (!fixup)
632 goto uncorrectable;
633 fixup->sdev = sdev;
634 fixup->logical = logical;
635 fixup->root = fs_info->extent_root;
636 fixup->mirror_num = sbio->spag[ix].mirror_num;
637 /*
638 * increment scrubs_running to prevent cancel requests from
639 * completing as long as a fixup worker is running. we must also
640 * increment scrubs_paused to prevent deadlocking on pause
641 * requests used for transactions commits (as the worker uses a
642 * transaction context). it is safe to regard the fixup worker
643 * as paused for all matters practical. effectively, we only
644 * avoid cancellation requests from completing.
645 */
646 mutex_lock(&fs_info->scrub_lock);
647 atomic_inc(&fs_info->scrubs_running);
648 atomic_inc(&fs_info->scrubs_paused);
649 mutex_unlock(&fs_info->scrub_lock);
650 atomic_inc(&sdev->fixup_cnt);
651 fixup->work.func = scrub_fixup_nodatasum;
652 btrfs_queue_worker(&fs_info->scrub_workers, &fixup->work);
653 return;
654 }
655
656 length = PAGE_SIZE;
657 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
658 &bbio, 0);
659 if (ret || !bbio || length < PAGE_SIZE) {
660 printk(KERN_ERR
661 "scrub_fixup: btrfs_map_block failed us for %llu\n",
662 (unsigned long long)logical);
663 WARN_ON(1);
664 kfree(bbio);
665 return;
666 }
667
668 if (bbio->num_stripes == 1)
669 /* there aren't any replicas */
670 goto uncorrectable;
671
672 /*
673 * first find a good copy
674 */
675 for (i = 0; i < bbio->num_stripes; ++i) {
676 if (i + 1 == sbio->spag[ix].mirror_num)
677 continue;
678
679 if (scrub_fixup_io(READ, bbio->stripes[i].dev->bdev,
680 bbio->stripes[i].physical >> 9,
681 sbio->bio->bi_io_vec[ix].bv_page)) {
682 /* I/O-error, this is not a good copy */
683 continue;
684 }
685
686 if (scrub_fixup_check(sbio, ix) == 0)
687 break;
688 }
689 if (i == bbio->num_stripes)
690 goto uncorrectable;
691
692 if (!sdev->readonly) {
693 /*
694 * bi_io_vec[ix].bv_page now contains good data, write it back
695 */
696 if (scrub_fixup_io(WRITE, sdev->dev->bdev,
697 (sbio->physical + ix * PAGE_SIZE) >> 9,
698 sbio->bio->bi_io_vec[ix].bv_page)) {
699 /* I/O-error, writeback failed, give up */
700 goto uncorrectable;
701 }
702 }
703
704 kfree(bbio);
705 spin_lock(&sdev->stat_lock);
706 ++sdev->stat.corrected_errors;
707 spin_unlock(&sdev->stat_lock);
708
709 printk_ratelimited(KERN_ERR "btrfs: fixed up error at logical %llu\n",
710 (unsigned long long)logical);
711 return;
712
713 uncorrectable:
714 kfree(bbio);
715 spin_lock(&sdev->stat_lock);
716 ++sdev->stat.uncorrectable_errors;
717 spin_unlock(&sdev->stat_lock);
718
719 printk_ratelimited(KERN_ERR "btrfs: unable to fixup (regular) error at "
720 "logical %llu\n", (unsigned long long)logical);
721 }
722
723 static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
724 struct page *page)
725 {
726 struct bio *bio = NULL;
727 int ret;
728 DECLARE_COMPLETION_ONSTACK(complete);
729
730 bio = bio_alloc(GFP_NOFS, 1);
731 bio->bi_bdev = bdev;
732 bio->bi_sector = sector;
733 bio_add_page(bio, page, PAGE_SIZE, 0);
734 bio->bi_end_io = scrub_fixup_end_io;
735 bio->bi_private = &complete;
736 submit_bio(rw, bio);
737
738 /* this will also unplug the queue */
739 wait_for_completion(&complete);
740
741 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
742 bio_put(bio);
743 return ret;
744 }
745
746 static void scrub_bio_end_io(struct bio *bio, int err)
747 {
748 struct scrub_bio *sbio = bio->bi_private;
749 struct scrub_dev *sdev = sbio->sdev;
750 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
751
752 sbio->err = err;
753 sbio->bio = bio;
754
755 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
756 }
757
758 static void scrub_checksum(struct btrfs_work *work)
759 {
760 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
761 struct scrub_dev *sdev = sbio->sdev;
762 struct page *page;
763 void *buffer;
764 int i;
765 u64 flags;
766 u64 logical;
767 int ret;
768
769 if (sbio->err) {
770 ret = 0;
771 for (i = 0; i < sbio->count; ++i)
772 ret |= scrub_recheck_error(sbio, i);
773 if (!ret) {
774 spin_lock(&sdev->stat_lock);
775 ++sdev->stat.unverified_errors;
776 spin_unlock(&sdev->stat_lock);
777 }
778
779 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
780 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
781 sbio->bio->bi_phys_segments = 0;
782 sbio->bio->bi_idx = 0;
783
784 for (i = 0; i < sbio->count; i++) {
785 struct bio_vec *bi;
786 bi = &sbio->bio->bi_io_vec[i];
787 bi->bv_offset = 0;
788 bi->bv_len = PAGE_SIZE;
789 }
790 goto out;
791 }
792 for (i = 0; i < sbio->count; ++i) {
793 page = sbio->bio->bi_io_vec[i].bv_page;
794 buffer = kmap_atomic(page, KM_USER0);
795 flags = sbio->spag[i].flags;
796 logical = sbio->logical + i * PAGE_SIZE;
797 ret = 0;
798 if (flags & BTRFS_EXTENT_FLAG_DATA) {
799 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer);
800 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
801 ret = scrub_checksum_tree_block(sdev, sbio->spag + i,
802 logical, buffer);
803 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) {
804 BUG_ON(i);
805 (void)scrub_checksum_super(sbio, buffer);
806 } else {
807 WARN_ON(1);
808 }
809 kunmap_atomic(buffer, KM_USER0);
810 if (ret) {
811 ret = scrub_recheck_error(sbio, i);
812 if (!ret) {
813 spin_lock(&sdev->stat_lock);
814 ++sdev->stat.unverified_errors;
815 spin_unlock(&sdev->stat_lock);
816 }
817 }
818 }
819
820 out:
821 scrub_free_bio(sbio->bio);
822 sbio->bio = NULL;
823 spin_lock(&sdev->list_lock);
824 sbio->next_free = sdev->first_free;
825 sdev->first_free = sbio->index;
826 spin_unlock(&sdev->list_lock);
827 atomic_dec(&sdev->in_flight);
828 wake_up(&sdev->list_wait);
829 }
830
831 static int scrub_checksum_data(struct scrub_dev *sdev,
832 struct scrub_page *spag, void *buffer)
833 {
834 u8 csum[BTRFS_CSUM_SIZE];
835 u32 crc = ~(u32)0;
836 int fail = 0;
837 struct btrfs_root *root = sdev->dev->dev_root;
838
839 if (!spag->have_csum)
840 return 0;
841
842 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE);
843 btrfs_csum_final(crc, csum);
844 if (memcmp(csum, spag->csum, sdev->csum_size))
845 fail = 1;
846
847 spin_lock(&sdev->stat_lock);
848 ++sdev->stat.data_extents_scrubbed;
849 sdev->stat.data_bytes_scrubbed += PAGE_SIZE;
850 if (fail)
851 ++sdev->stat.csum_errors;
852 spin_unlock(&sdev->stat_lock);
853
854 return fail;
855 }
856
857 static int scrub_checksum_tree_block(struct scrub_dev *sdev,
858 struct scrub_page *spag, u64 logical,
859 void *buffer)
860 {
861 struct btrfs_header *h;
862 struct btrfs_root *root = sdev->dev->dev_root;
863 struct btrfs_fs_info *fs_info = root->fs_info;
864 u8 csum[BTRFS_CSUM_SIZE];
865 u32 crc = ~(u32)0;
866 int fail = 0;
867 int crc_fail = 0;
868
869 /*
870 * we don't use the getter functions here, as we
871 * a) don't have an extent buffer and
872 * b) the page is already kmapped
873 */
874 h = (struct btrfs_header *)buffer;
875
876 if (logical != le64_to_cpu(h->bytenr))
877 ++fail;
878
879 if (spag->generation != le64_to_cpu(h->generation))
880 ++fail;
881
882 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
883 ++fail;
884
885 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
886 BTRFS_UUID_SIZE))
887 ++fail;
888
889 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
890 PAGE_SIZE - BTRFS_CSUM_SIZE);
891 btrfs_csum_final(crc, csum);
892 if (memcmp(csum, h->csum, sdev->csum_size))
893 ++crc_fail;
894
895 spin_lock(&sdev->stat_lock);
896 ++sdev->stat.tree_extents_scrubbed;
897 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE;
898 if (crc_fail)
899 ++sdev->stat.csum_errors;
900 if (fail)
901 ++sdev->stat.verify_errors;
902 spin_unlock(&sdev->stat_lock);
903
904 return fail || crc_fail;
905 }
906
907 static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
908 {
909 struct btrfs_super_block *s;
910 u64 logical;
911 struct scrub_dev *sdev = sbio->sdev;
912 struct btrfs_root *root = sdev->dev->dev_root;
913 struct btrfs_fs_info *fs_info = root->fs_info;
914 u8 csum[BTRFS_CSUM_SIZE];
915 u32 crc = ~(u32)0;
916 int fail = 0;
917
918 s = (struct btrfs_super_block *)buffer;
919 logical = sbio->logical;
920
921 if (logical != le64_to_cpu(s->bytenr))
922 ++fail;
923
924 if (sbio->spag[0].generation != le64_to_cpu(s->generation))
925 ++fail;
926
927 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
928 ++fail;
929
930 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
931 PAGE_SIZE - BTRFS_CSUM_SIZE);
932 btrfs_csum_final(crc, csum);
933 if (memcmp(csum, s->csum, sbio->sdev->csum_size))
934 ++fail;
935
936 if (fail) {
937 /*
938 * if we find an error in a super block, we just report it.
939 * They will get written with the next transaction commit
940 * anyway
941 */
942 spin_lock(&sdev->stat_lock);
943 ++sdev->stat.super_errors;
944 spin_unlock(&sdev->stat_lock);
945 }
946
947 return fail;
948 }
949
950 static int scrub_submit(struct scrub_dev *sdev)
951 {
952 struct scrub_bio *sbio;
953
954 if (sdev->curr == -1)
955 return 0;
956
957 sbio = sdev->bios[sdev->curr];
958 sbio->err = 0;
959 sdev->curr = -1;
960 atomic_inc(&sdev->in_flight);
961
962 submit_bio(READ, sbio->bio);
963
964 return 0;
965 }
966
967 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
968 u64 physical, u64 flags, u64 gen, int mirror_num,
969 u8 *csum, int force)
970 {
971 struct scrub_bio *sbio;
972 struct page *page;
973 int ret;
974
975 again:
976 /*
977 * grab a fresh bio or wait for one to become available
978 */
979 while (sdev->curr == -1) {
980 spin_lock(&sdev->list_lock);
981 sdev->curr = sdev->first_free;
982 if (sdev->curr != -1) {
983 sdev->first_free = sdev->bios[sdev->curr]->next_free;
984 sdev->bios[sdev->curr]->next_free = -1;
985 sdev->bios[sdev->curr]->count = 0;
986 spin_unlock(&sdev->list_lock);
987 } else {
988 spin_unlock(&sdev->list_lock);
989 wait_event(sdev->list_wait, sdev->first_free != -1);
990 }
991 }
992 sbio = sdev->bios[sdev->curr];
993 if (sbio->count == 0) {
994 struct bio *bio;
995
996 sbio->physical = physical;
997 sbio->logical = logical;
998 bio = bio_alloc(GFP_NOFS, SCRUB_PAGES_PER_BIO);
999 if (!bio)
1000 return -ENOMEM;
1001
1002 bio->bi_private = sbio;
1003 bio->bi_end_io = scrub_bio_end_io;
1004 bio->bi_bdev = sdev->dev->bdev;
1005 bio->bi_sector = sbio->physical >> 9;
1006 sbio->err = 0;
1007 sbio->bio = bio;
1008 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
1009 sbio->logical + sbio->count * PAGE_SIZE != logical) {
1010 ret = scrub_submit(sdev);
1011 if (ret)
1012 return ret;
1013 goto again;
1014 }
1015 sbio->spag[sbio->count].flags = flags;
1016 sbio->spag[sbio->count].generation = gen;
1017 sbio->spag[sbio->count].have_csum = 0;
1018 sbio->spag[sbio->count].mirror_num = mirror_num;
1019
1020 page = alloc_page(GFP_NOFS);
1021 if (!page)
1022 return -ENOMEM;
1023
1024 ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0);
1025 if (!ret) {
1026 __free_page(page);
1027 ret = scrub_submit(sdev);
1028 if (ret)
1029 return ret;
1030 goto again;
1031 }
1032
1033 if (csum) {
1034 sbio->spag[sbio->count].have_csum = 1;
1035 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
1036 }
1037 ++sbio->count;
1038 if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
1039 int ret;
1040
1041 ret = scrub_submit(sdev);
1042 if (ret)
1043 return ret;
1044 }
1045
1046 return 0;
1047 }
1048
1049 static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
1050 u8 *csum)
1051 {
1052 struct btrfs_ordered_sum *sum = NULL;
1053 int ret = 0;
1054 unsigned long i;
1055 unsigned long num_sectors;
1056 u32 sectorsize = sdev->dev->dev_root->sectorsize;
1057
1058 while (!list_empty(&sdev->csum_list)) {
1059 sum = list_first_entry(&sdev->csum_list,
1060 struct btrfs_ordered_sum, list);
1061 if (sum->bytenr > logical)
1062 return 0;
1063 if (sum->bytenr + sum->len > logical)
1064 break;
1065
1066 ++sdev->stat.csum_discards;
1067 list_del(&sum->list);
1068 kfree(sum);
1069 sum = NULL;
1070 }
1071 if (!sum)
1072 return 0;
1073
1074 num_sectors = sum->len / sectorsize;
1075 for (i = 0; i < num_sectors; ++i) {
1076 if (sum->sums[i].bytenr == logical) {
1077 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
1078 ret = 1;
1079 break;
1080 }
1081 }
1082 if (ret && i == num_sectors - 1) {
1083 list_del(&sum->list);
1084 kfree(sum);
1085 }
1086 return ret;
1087 }
1088
1089 /* scrub extent tries to collect up to 64 kB for each bio */
1090 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
1091 u64 physical, u64 flags, u64 gen, int mirror_num)
1092 {
1093 int ret;
1094 u8 csum[BTRFS_CSUM_SIZE];
1095
1096 while (len) {
1097 u64 l = min_t(u64, len, PAGE_SIZE);
1098 int have_csum = 0;
1099
1100 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1101 /* push csums to sbio */
1102 have_csum = scrub_find_csum(sdev, logical, l, csum);
1103 if (have_csum == 0)
1104 ++sdev->stat.no_csum;
1105 }
1106 ret = scrub_page(sdev, logical, l, physical, flags, gen,
1107 mirror_num, have_csum ? csum : NULL, 0);
1108 if (ret)
1109 return ret;
1110 len -= l;
1111 logical += l;
1112 physical += l;
1113 }
1114 return 0;
1115 }
1116
1117 static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
1118 struct map_lookup *map, int num, u64 base, u64 length)
1119 {
1120 struct btrfs_path *path;
1121 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1122 struct btrfs_root *root = fs_info->extent_root;
1123 struct btrfs_root *csum_root = fs_info->csum_root;
1124 struct btrfs_extent_item *extent;
1125 struct blk_plug plug;
1126 u64 flags;
1127 int ret;
1128 int slot;
1129 int i;
1130 u64 nstripes;
1131 struct extent_buffer *l;
1132 struct btrfs_key key;
1133 u64 physical;
1134 u64 logical;
1135 u64 generation;
1136 int mirror_num;
1137 struct reada_control *reada1;
1138 struct reada_control *reada2;
1139 struct btrfs_key key_start;
1140 struct btrfs_key key_end;
1141
1142 u64 increment = map->stripe_len;
1143 u64 offset;
1144
1145 nstripes = length;
1146 offset = 0;
1147 do_div(nstripes, map->stripe_len);
1148 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1149 offset = map->stripe_len * num;
1150 increment = map->stripe_len * map->num_stripes;
1151 mirror_num = 1;
1152 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1153 int factor = map->num_stripes / map->sub_stripes;
1154 offset = map->stripe_len * (num / map->sub_stripes);
1155 increment = map->stripe_len * factor;
1156 mirror_num = num % map->sub_stripes + 1;
1157 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1158 increment = map->stripe_len;
1159 mirror_num = num % map->num_stripes + 1;
1160 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1161 increment = map->stripe_len;
1162 mirror_num = num % map->num_stripes + 1;
1163 } else {
1164 increment = map->stripe_len;
1165 mirror_num = 1;
1166 }
1167
1168 path = btrfs_alloc_path();
1169 if (!path)
1170 return -ENOMEM;
1171
1172 path->search_commit_root = 1;
1173 path->skip_locking = 1;
1174
1175 /*
1176 * trigger the readahead for extent tree csum tree and wait for
1177 * completion. During readahead, the scrub is officially paused
1178 * to not hold off transaction commits
1179 */
1180 logical = base + offset;
1181
1182 wait_event(sdev->list_wait,
1183 atomic_read(&sdev->in_flight) == 0);
1184 atomic_inc(&fs_info->scrubs_paused);
1185 wake_up(&fs_info->scrub_pause_wait);
1186
1187 /* FIXME it might be better to start readahead at commit root */
1188 key_start.objectid = logical;
1189 key_start.type = BTRFS_EXTENT_ITEM_KEY;
1190 key_start.offset = (u64)0;
1191 key_end.objectid = base + offset + nstripes * increment;
1192 key_end.type = BTRFS_EXTENT_ITEM_KEY;
1193 key_end.offset = (u64)0;
1194 reada1 = btrfs_reada_add(root, &key_start, &key_end);
1195
1196 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1197 key_start.type = BTRFS_EXTENT_CSUM_KEY;
1198 key_start.offset = logical;
1199 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1200 key_end.type = BTRFS_EXTENT_CSUM_KEY;
1201 key_end.offset = base + offset + nstripes * increment;
1202 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
1203
1204 if (!IS_ERR(reada1))
1205 btrfs_reada_wait(reada1);
1206 if (!IS_ERR(reada2))
1207 btrfs_reada_wait(reada2);
1208
1209 mutex_lock(&fs_info->scrub_lock);
1210 while (atomic_read(&fs_info->scrub_pause_req)) {
1211 mutex_unlock(&fs_info->scrub_lock);
1212 wait_event(fs_info->scrub_pause_wait,
1213 atomic_read(&fs_info->scrub_pause_req) == 0);
1214 mutex_lock(&fs_info->scrub_lock);
1215 }
1216 atomic_dec(&fs_info->scrubs_paused);
1217 mutex_unlock(&fs_info->scrub_lock);
1218 wake_up(&fs_info->scrub_pause_wait);
1219
1220 /*
1221 * collect all data csums for the stripe to avoid seeking during
1222 * the scrub. This might currently (crc32) end up to be about 1MB
1223 */
1224 blk_start_plug(&plug);
1225
1226 /*
1227 * now find all extents for each stripe and scrub them
1228 */
1229 logical = base + offset;
1230 physical = map->stripes[num].physical;
1231 ret = 0;
1232 for (i = 0; i < nstripes; ++i) {
1233 /*
1234 * canceled?
1235 */
1236 if (atomic_read(&fs_info->scrub_cancel_req) ||
1237 atomic_read(&sdev->cancel_req)) {
1238 ret = -ECANCELED;
1239 goto out;
1240 }
1241 /*
1242 * check to see if we have to pause
1243 */
1244 if (atomic_read(&fs_info->scrub_pause_req)) {
1245 /* push queued extents */
1246 scrub_submit(sdev);
1247 wait_event(sdev->list_wait,
1248 atomic_read(&sdev->in_flight) == 0);
1249 atomic_inc(&fs_info->scrubs_paused);
1250 wake_up(&fs_info->scrub_pause_wait);
1251 mutex_lock(&fs_info->scrub_lock);
1252 while (atomic_read(&fs_info->scrub_pause_req)) {
1253 mutex_unlock(&fs_info->scrub_lock);
1254 wait_event(fs_info->scrub_pause_wait,
1255 atomic_read(&fs_info->scrub_pause_req) == 0);
1256 mutex_lock(&fs_info->scrub_lock);
1257 }
1258 atomic_dec(&fs_info->scrubs_paused);
1259 mutex_unlock(&fs_info->scrub_lock);
1260 wake_up(&fs_info->scrub_pause_wait);
1261 }
1262
1263 ret = btrfs_lookup_csums_range(csum_root, logical,
1264 logical + map->stripe_len - 1,
1265 &sdev->csum_list, 1);
1266 if (ret)
1267 goto out;
1268
1269 key.objectid = logical;
1270 key.type = BTRFS_EXTENT_ITEM_KEY;
1271 key.offset = (u64)0;
1272
1273 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1274 if (ret < 0)
1275 goto out;
1276 if (ret > 0) {
1277 ret = btrfs_previous_item(root, path, 0,
1278 BTRFS_EXTENT_ITEM_KEY);
1279 if (ret < 0)
1280 goto out;
1281 if (ret > 0) {
1282 /* there's no smaller item, so stick with the
1283 * larger one */
1284 btrfs_release_path(path);
1285 ret = btrfs_search_slot(NULL, root, &key,
1286 path, 0, 0);
1287 if (ret < 0)
1288 goto out;
1289 }
1290 }
1291
1292 while (1) {
1293 l = path->nodes[0];
1294 slot = path->slots[0];
1295 if (slot >= btrfs_header_nritems(l)) {
1296 ret = btrfs_next_leaf(root, path);
1297 if (ret == 0)
1298 continue;
1299 if (ret < 0)
1300 goto out;
1301
1302 break;
1303 }
1304 btrfs_item_key_to_cpu(l, &key, slot);
1305
1306 if (key.objectid + key.offset <= logical)
1307 goto next;
1308
1309 if (key.objectid >= logical + map->stripe_len)
1310 break;
1311
1312 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1313 goto next;
1314
1315 extent = btrfs_item_ptr(l, slot,
1316 struct btrfs_extent_item);
1317 flags = btrfs_extent_flags(l, extent);
1318 generation = btrfs_extent_generation(l, extent);
1319
1320 if (key.objectid < logical &&
1321 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1322 printk(KERN_ERR
1323 "btrfs scrub: tree block %llu spanning "
1324 "stripes, ignored. logical=%llu\n",
1325 (unsigned long long)key.objectid,
1326 (unsigned long long)logical);
1327 goto next;
1328 }
1329
1330 /*
1331 * trim extent to this stripe
1332 */
1333 if (key.objectid < logical) {
1334 key.offset -= logical - key.objectid;
1335 key.objectid = logical;
1336 }
1337 if (key.objectid + key.offset >
1338 logical + map->stripe_len) {
1339 key.offset = logical + map->stripe_len -
1340 key.objectid;
1341 }
1342
1343 ret = scrub_extent(sdev, key.objectid, key.offset,
1344 key.objectid - logical + physical,
1345 flags, generation, mirror_num);
1346 if (ret)
1347 goto out;
1348
1349 next:
1350 path->slots[0]++;
1351 }
1352 btrfs_release_path(path);
1353 logical += increment;
1354 physical += map->stripe_len;
1355 spin_lock(&sdev->stat_lock);
1356 sdev->stat.last_physical = physical;
1357 spin_unlock(&sdev->stat_lock);
1358 }
1359 /* push queued extents */
1360 scrub_submit(sdev);
1361
1362 out:
1363 blk_finish_plug(&plug);
1364 btrfs_free_path(path);
1365 return ret < 0 ? ret : 0;
1366 }
1367
1368 static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
1369 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length)
1370 {
1371 struct btrfs_mapping_tree *map_tree =
1372 &sdev->dev->dev_root->fs_info->mapping_tree;
1373 struct map_lookup *map;
1374 struct extent_map *em;
1375 int i;
1376 int ret = -EINVAL;
1377
1378 read_lock(&map_tree->map_tree.lock);
1379 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
1380 read_unlock(&map_tree->map_tree.lock);
1381
1382 if (!em)
1383 return -EINVAL;
1384
1385 map = (struct map_lookup *)em->bdev;
1386 if (em->start != chunk_offset)
1387 goto out;
1388
1389 if (em->len < length)
1390 goto out;
1391
1392 for (i = 0; i < map->num_stripes; ++i) {
1393 if (map->stripes[i].dev == sdev->dev) {
1394 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
1395 if (ret)
1396 goto out;
1397 }
1398 }
1399 out:
1400 free_extent_map(em);
1401
1402 return ret;
1403 }
1404
1405 static noinline_for_stack
1406 int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
1407 {
1408 struct btrfs_dev_extent *dev_extent = NULL;
1409 struct btrfs_path *path;
1410 struct btrfs_root *root = sdev->dev->dev_root;
1411 struct btrfs_fs_info *fs_info = root->fs_info;
1412 u64 length;
1413 u64 chunk_tree;
1414 u64 chunk_objectid;
1415 u64 chunk_offset;
1416 int ret;
1417 int slot;
1418 struct extent_buffer *l;
1419 struct btrfs_key key;
1420 struct btrfs_key found_key;
1421 struct btrfs_block_group_cache *cache;
1422
1423 path = btrfs_alloc_path();
1424 if (!path)
1425 return -ENOMEM;
1426
1427 path->reada = 2;
1428 path->search_commit_root = 1;
1429 path->skip_locking = 1;
1430
1431 key.objectid = sdev->dev->devid;
1432 key.offset = 0ull;
1433 key.type = BTRFS_DEV_EXTENT_KEY;
1434
1435
1436 while (1) {
1437 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1438 if (ret < 0)
1439 break;
1440 if (ret > 0) {
1441 if (path->slots[0] >=
1442 btrfs_header_nritems(path->nodes[0])) {
1443 ret = btrfs_next_leaf(root, path);
1444 if (ret)
1445 break;
1446 }
1447 }
1448
1449 l = path->nodes[0];
1450 slot = path->slots[0];
1451
1452 btrfs_item_key_to_cpu(l, &found_key, slot);
1453
1454 if (found_key.objectid != sdev->dev->devid)
1455 break;
1456
1457 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
1458 break;
1459
1460 if (found_key.offset >= end)
1461 break;
1462
1463 if (found_key.offset < key.offset)
1464 break;
1465
1466 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1467 length = btrfs_dev_extent_length(l, dev_extent);
1468
1469 if (found_key.offset + length <= start) {
1470 key.offset = found_key.offset + length;
1471 btrfs_release_path(path);
1472 continue;
1473 }
1474
1475 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1476 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1477 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1478
1479 /*
1480 * get a reference on the corresponding block group to prevent
1481 * the chunk from going away while we scrub it
1482 */
1483 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
1484 if (!cache) {
1485 ret = -ENOENT;
1486 break;
1487 }
1488 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
1489 chunk_offset, length);
1490 btrfs_put_block_group(cache);
1491 if (ret)
1492 break;
1493
1494 key.offset = found_key.offset + length;
1495 btrfs_release_path(path);
1496 }
1497
1498 btrfs_free_path(path);
1499
1500 /*
1501 * ret can still be 1 from search_slot or next_leaf,
1502 * that's not an error
1503 */
1504 return ret < 0 ? ret : 0;
1505 }
1506
1507 static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
1508 {
1509 int i;
1510 u64 bytenr;
1511 u64 gen;
1512 int ret;
1513 struct btrfs_device *device = sdev->dev;
1514 struct btrfs_root *root = device->dev_root;
1515
1516 gen = root->fs_info->last_trans_committed;
1517
1518 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1519 bytenr = btrfs_sb_offset(i);
1520 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1521 break;
1522
1523 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr,
1524 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
1525 if (ret)
1526 return ret;
1527 }
1528 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1529
1530 return 0;
1531 }
1532
1533 /*
1534 * get a reference count on fs_info->scrub_workers. start worker if necessary
1535 */
1536 static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
1537 {
1538 struct btrfs_fs_info *fs_info = root->fs_info;
1539 int ret = 0;
1540
1541 mutex_lock(&fs_info->scrub_lock);
1542 if (fs_info->scrub_workers_refcnt == 0) {
1543 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
1544 fs_info->thread_pool_size, &fs_info->generic_worker);
1545 fs_info->scrub_workers.idle_thresh = 4;
1546 ret = btrfs_start_workers(&fs_info->scrub_workers);
1547 if (ret)
1548 goto out;
1549 }
1550 ++fs_info->scrub_workers_refcnt;
1551 out:
1552 mutex_unlock(&fs_info->scrub_lock);
1553
1554 return ret;
1555 }
1556
1557 static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
1558 {
1559 struct btrfs_fs_info *fs_info = root->fs_info;
1560
1561 mutex_lock(&fs_info->scrub_lock);
1562 if (--fs_info->scrub_workers_refcnt == 0)
1563 btrfs_stop_workers(&fs_info->scrub_workers);
1564 WARN_ON(fs_info->scrub_workers_refcnt < 0);
1565 mutex_unlock(&fs_info->scrub_lock);
1566 }
1567
1568
1569 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
1570 struct btrfs_scrub_progress *progress, int readonly)
1571 {
1572 struct scrub_dev *sdev;
1573 struct btrfs_fs_info *fs_info = root->fs_info;
1574 int ret;
1575 struct btrfs_device *dev;
1576
1577 if (btrfs_fs_closing(root->fs_info))
1578 return -EINVAL;
1579
1580 /*
1581 * check some assumptions
1582 */
1583 if (root->sectorsize != PAGE_SIZE ||
1584 root->sectorsize != root->leafsize ||
1585 root->sectorsize != root->nodesize) {
1586 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n");
1587 return -EINVAL;
1588 }
1589
1590 ret = scrub_workers_get(root);
1591 if (ret)
1592 return ret;
1593
1594 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1595 dev = btrfs_find_device(root, devid, NULL, NULL);
1596 if (!dev || dev->missing) {
1597 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1598 scrub_workers_put(root);
1599 return -ENODEV;
1600 }
1601 mutex_lock(&fs_info->scrub_lock);
1602
1603 if (!dev->in_fs_metadata) {
1604 mutex_unlock(&fs_info->scrub_lock);
1605 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1606 scrub_workers_put(root);
1607 return -ENODEV;
1608 }
1609
1610 if (dev->scrub_device) {
1611 mutex_unlock(&fs_info->scrub_lock);
1612 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1613 scrub_workers_put(root);
1614 return -EINPROGRESS;
1615 }
1616 sdev = scrub_setup_dev(dev);
1617 if (IS_ERR(sdev)) {
1618 mutex_unlock(&fs_info->scrub_lock);
1619 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1620 scrub_workers_put(root);
1621 return PTR_ERR(sdev);
1622 }
1623 sdev->readonly = readonly;
1624 dev->scrub_device = sdev;
1625
1626 atomic_inc(&fs_info->scrubs_running);
1627 mutex_unlock(&fs_info->scrub_lock);
1628 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1629
1630 down_read(&fs_info->scrub_super_lock);
1631 ret = scrub_supers(sdev);
1632 up_read(&fs_info->scrub_super_lock);
1633
1634 if (!ret)
1635 ret = scrub_enumerate_chunks(sdev, start, end);
1636
1637 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1638 atomic_dec(&fs_info->scrubs_running);
1639 wake_up(&fs_info->scrub_pause_wait);
1640
1641 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
1642
1643 if (progress)
1644 memcpy(progress, &sdev->stat, sizeof(*progress));
1645
1646 mutex_lock(&fs_info->scrub_lock);
1647 dev->scrub_device = NULL;
1648 mutex_unlock(&fs_info->scrub_lock);
1649
1650 scrub_free_dev(sdev);
1651 scrub_workers_put(root);
1652
1653 return ret;
1654 }
1655
1656 int btrfs_scrub_pause(struct btrfs_root *root)
1657 {
1658 struct btrfs_fs_info *fs_info = root->fs_info;
1659
1660 mutex_lock(&fs_info->scrub_lock);
1661 atomic_inc(&fs_info->scrub_pause_req);
1662 while (atomic_read(&fs_info->scrubs_paused) !=
1663 atomic_read(&fs_info->scrubs_running)) {
1664 mutex_unlock(&fs_info->scrub_lock);
1665 wait_event(fs_info->scrub_pause_wait,
1666 atomic_read(&fs_info->scrubs_paused) ==
1667 atomic_read(&fs_info->scrubs_running));
1668 mutex_lock(&fs_info->scrub_lock);
1669 }
1670 mutex_unlock(&fs_info->scrub_lock);
1671
1672 return 0;
1673 }
1674
1675 int btrfs_scrub_continue(struct btrfs_root *root)
1676 {
1677 struct btrfs_fs_info *fs_info = root->fs_info;
1678
1679 atomic_dec(&fs_info->scrub_pause_req);
1680 wake_up(&fs_info->scrub_pause_wait);
1681 return 0;
1682 }
1683
1684 int btrfs_scrub_pause_super(struct btrfs_root *root)
1685 {
1686 down_write(&root->fs_info->scrub_super_lock);
1687 return 0;
1688 }
1689
1690 int btrfs_scrub_continue_super(struct btrfs_root *root)
1691 {
1692 up_write(&root->fs_info->scrub_super_lock);
1693 return 0;
1694 }
1695
1696 int btrfs_scrub_cancel(struct btrfs_root *root)
1697 {
1698 struct btrfs_fs_info *fs_info = root->fs_info;
1699
1700 mutex_lock(&fs_info->scrub_lock);
1701 if (!atomic_read(&fs_info->scrubs_running)) {
1702 mutex_unlock(&fs_info->scrub_lock);
1703 return -ENOTCONN;
1704 }
1705
1706 atomic_inc(&fs_info->scrub_cancel_req);
1707 while (atomic_read(&fs_info->scrubs_running)) {
1708 mutex_unlock(&fs_info->scrub_lock);
1709 wait_event(fs_info->scrub_pause_wait,
1710 atomic_read(&fs_info->scrubs_running) == 0);
1711 mutex_lock(&fs_info->scrub_lock);
1712 }
1713 atomic_dec(&fs_info->scrub_cancel_req);
1714 mutex_unlock(&fs_info->scrub_lock);
1715
1716 return 0;
1717 }
1718
1719 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
1720 {
1721 struct btrfs_fs_info *fs_info = root->fs_info;
1722 struct scrub_dev *sdev;
1723
1724 mutex_lock(&fs_info->scrub_lock);
1725 sdev = dev->scrub_device;
1726 if (!sdev) {
1727 mutex_unlock(&fs_info->scrub_lock);
1728 return -ENOTCONN;
1729 }
1730 atomic_inc(&sdev->cancel_req);
1731 while (dev->scrub_device) {
1732 mutex_unlock(&fs_info->scrub_lock);
1733 wait_event(fs_info->scrub_pause_wait,
1734 dev->scrub_device == NULL);
1735 mutex_lock(&fs_info->scrub_lock);
1736 }
1737 mutex_unlock(&fs_info->scrub_lock);
1738
1739 return 0;
1740 }
1741 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
1742 {
1743 struct btrfs_fs_info *fs_info = root->fs_info;
1744 struct btrfs_device *dev;
1745 int ret;
1746
1747 /*
1748 * we have to hold the device_list_mutex here so the device
1749 * does not go away in cancel_dev. FIXME: find a better solution
1750 */
1751 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1752 dev = btrfs_find_device(root, devid, NULL, NULL);
1753 if (!dev) {
1754 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1755 return -ENODEV;
1756 }
1757 ret = btrfs_scrub_cancel_dev(root, dev);
1758 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1759
1760 return ret;
1761 }
1762
1763 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
1764 struct btrfs_scrub_progress *progress)
1765 {
1766 struct btrfs_device *dev;
1767 struct scrub_dev *sdev = NULL;
1768
1769 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1770 dev = btrfs_find_device(root, devid, NULL, NULL);
1771 if (dev)
1772 sdev = dev->scrub_device;
1773 if (sdev)
1774 memcpy(progress, &sdev->stat, sizeof(*progress));
1775 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1776
1777 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
1778 }
ubuntu-bionic-kernel mirror