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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 "ctree.h"
21#include "volumes.h"
22#include "disk-io.h"
23#include "ordered-data.h"
24
25/*
26 * This is only the first step towards a full-features scrub. It reads all
27 * extent and super block and verifies the checksums. In case a bad checksum
28 * is found or the extent cannot be read, good data will be written back if
29 * any can be found.
30 *
31 * Future enhancements:
32 * - To enhance the performance, better read-ahead strategies for the
33 * extent-tree can be employed.
34 * - In case an unrepairable extent is encountered, track which files are
35 * affected and report them
36 * - In case of a read error on files with nodatasum, map the file and read
37 * the extent to trigger a writeback of the good copy
38 * - track and record media errors, throw out bad devices
39 * - add a mode to also read unallocated space
40 * - make the prefetch cancellable
41 */
42
43struct scrub_bio;
44struct scrub_page;
45struct scrub_dev;
46static void scrub_bio_end_io(struct bio *bio, int err);
47static void scrub_checksum(struct btrfs_work *work);
48static int scrub_checksum_data(struct scrub_dev *sdev,
49 struct scrub_page *spag, void *buffer);
50static int scrub_checksum_tree_block(struct scrub_dev *sdev,
51 struct scrub_page *spag, u64 logical,
52 void *buffer);
53static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer);
54static int scrub_fixup_check(struct scrub_bio *sbio, int ix);
55static void scrub_fixup_end_io(struct bio *bio, int err);
56static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
57 struct page *page);
58static void scrub_fixup(struct scrub_bio *sbio, int ix);
59
60#define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
61#define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
62
63struct scrub_page {
64 u64 flags; /* extent flags */
65 u64 generation;
66 u64 mirror_num;
67 int have_csum;
68 u8 csum[BTRFS_CSUM_SIZE];
69};
70
71struct scrub_bio {
72 int index;
73 struct scrub_dev *sdev;
74 struct bio *bio;
75 int err;
76 u64 logical;
77 u64 physical;
78 struct scrub_page spag[SCRUB_PAGES_PER_BIO];
79 u64 count;
80 int next_free;
81 struct btrfs_work work;
82};
83
84struct scrub_dev {
85 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
86 struct btrfs_device *dev;
87 int first_free;
88 int curr;
89 atomic_t in_flight;
90 spinlock_t list_lock;
91 wait_queue_head_t list_wait;
92 u16 csum_size;
93 struct list_head csum_list;
94 atomic_t cancel_req;
95 int readonly;
96 /*
97 * statistics
98 */
99 struct btrfs_scrub_progress stat;
100 spinlock_t stat_lock;
101};
102
103static void scrub_free_csums(struct scrub_dev *sdev)
104{
105 while (!list_empty(&sdev->csum_list)) {
106 struct btrfs_ordered_sum *sum;
107 sum = list_first_entry(&sdev->csum_list,
108 struct btrfs_ordered_sum, list);
109 list_del(&sum->list);
110 kfree(sum);
111 }
112}
113
114static void scrub_free_bio(struct bio *bio)
115{
116 int i;
117 struct page *last_page = NULL;
118
119 if (!bio)
120 return;
121
122 for (i = 0; i < bio->bi_vcnt; ++i) {
123 if (bio->bi_io_vec[i].bv_page == last_page)
124 continue;
125 last_page = bio->bi_io_vec[i].bv_page;
126 __free_page(last_page);
127 }
128 bio_put(bio);
129}
130
131static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
132{
133 int i;
134
135 if (!sdev)
136 return;
137
138 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
139 struct scrub_bio *sbio = sdev->bios[i];
140
141 if (!sbio)
142 break;
143
144 scrub_free_bio(sbio->bio);
145 kfree(sbio);
146 }
147
148 scrub_free_csums(sdev);
149 kfree(sdev);
150}
151
152static noinline_for_stack
153struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
154{
155 struct scrub_dev *sdev;
156 int i;
157 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
158
159 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
160 if (!sdev)
161 goto nomem;
162 sdev->dev = dev;
163 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
164 struct scrub_bio *sbio;
165
166 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
167 if (!sbio)
168 goto nomem;
169 sdev->bios[i] = sbio;
170
171 sbio->index = i;
172 sbio->sdev = sdev;
173 sbio->count = 0;
174 sbio->work.func = scrub_checksum;
175
176 if (i != SCRUB_BIOS_PER_DEV-1)
177 sdev->bios[i]->next_free = i + 1;
178 else
179 sdev->bios[i]->next_free = -1;
180 }
181 sdev->first_free = 0;
182 sdev->curr = -1;
183 atomic_set(&sdev->in_flight, 0);
184 atomic_set(&sdev->cancel_req, 0);
185 sdev->csum_size = btrfs_super_csum_size(&fs_info->super_copy);
186 INIT_LIST_HEAD(&sdev->csum_list);
187
188 spin_lock_init(&sdev->list_lock);
189 spin_lock_init(&sdev->stat_lock);
190 init_waitqueue_head(&sdev->list_wait);
191 return sdev;
192
193nomem:
194 scrub_free_dev(sdev);
195 return ERR_PTR(-ENOMEM);
196}
197
198/*
199 * scrub_recheck_error gets called when either verification of the page
200 * failed or the bio failed to read, e.g. with EIO. In the latter case,
201 * recheck_error gets called for every page in the bio, even though only
202 * one may be bad
203 */
204static void scrub_recheck_error(struct scrub_bio *sbio, int ix)
205{
206 if (sbio->err) {
207 if (scrub_fixup_io(READ, sbio->sdev->dev->bdev,
208 (sbio->physical + ix * PAGE_SIZE) >> 9,
209 sbio->bio->bi_io_vec[ix].bv_page) == 0) {
210 if (scrub_fixup_check(sbio, ix) == 0)
211 return;
212 }
213 }
214
215 scrub_fixup(sbio, ix);
216}
217
218static int scrub_fixup_check(struct scrub_bio *sbio, int ix)
219{
220 int ret = 1;
221 struct page *page;
222 void *buffer;
223 u64 flags = sbio->spag[ix].flags;
224
225 page = sbio->bio->bi_io_vec[ix].bv_page;
226 buffer = kmap_atomic(page, KM_USER0);
227 if (flags & BTRFS_EXTENT_FLAG_DATA) {
228 ret = scrub_checksum_data(sbio->sdev,
229 sbio->spag + ix, buffer);
230 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
231 ret = scrub_checksum_tree_block(sbio->sdev,
232 sbio->spag + ix,
233 sbio->logical + ix * PAGE_SIZE,
234 buffer);
235 } else {
236 WARN_ON(1);
237 }
238 kunmap_atomic(buffer, KM_USER0);
239
240 return ret;
241}
242
243static void scrub_fixup_end_io(struct bio *bio, int err)
244{
245 complete((struct completion *)bio->bi_private);
246}
247
248static void scrub_fixup(struct scrub_bio *sbio, int ix)
249{
250 struct scrub_dev *sdev = sbio->sdev;
251 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
252 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
253 struct btrfs_multi_bio *multi = NULL;
254 u64 logical = sbio->logical + ix * PAGE_SIZE;
255 u64 length;
256 int i;
257 int ret;
258 DECLARE_COMPLETION_ONSTACK(complete);
259
260 if ((sbio->spag[ix].flags & BTRFS_EXTENT_FLAG_DATA) &&
261 (sbio->spag[ix].have_csum == 0)) {
262 /*
263 * nodatasum, don't try to fix anything
264 * FIXME: we can do better, open the inode and trigger a
265 * writeback
266 */
267 goto uncorrectable;
268 }
269
270 length = PAGE_SIZE;
271 ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length,
272 &multi, 0);
273 if (ret || !multi || length < PAGE_SIZE) {
274 printk(KERN_ERR
275 "scrub_fixup: btrfs_map_block failed us for %llu\n",
276 (unsigned long long)logical);
277 WARN_ON(1);
278 return;
279 }
280
281 if (multi->num_stripes == 1)
282 /* there aren't any replicas */
283 goto uncorrectable;
284
285 /*
286 * first find a good copy
287 */
288 for (i = 0; i < multi->num_stripes; ++i) {
289 if (i == sbio->spag[ix].mirror_num)
290 continue;
291
292 if (scrub_fixup_io(READ, multi->stripes[i].dev->bdev,
293 multi->stripes[i].physical >> 9,
294 sbio->bio->bi_io_vec[ix].bv_page)) {
295 /* I/O-error, this is not a good copy */
296 continue;
297 }
298
299 if (scrub_fixup_check(sbio, ix) == 0)
300 break;
301 }
302 if (i == multi->num_stripes)
303 goto uncorrectable;
304
305 if (!sdev->readonly) {
306 /*
307 * bi_io_vec[ix].bv_page now contains good data, write it back
308 */
309 if (scrub_fixup_io(WRITE, sdev->dev->bdev,
310 (sbio->physical + ix * PAGE_SIZE) >> 9,
311 sbio->bio->bi_io_vec[ix].bv_page)) {
312 /* I/O-error, writeback failed, give up */
313 goto uncorrectable;
314 }
315 }
316
317 kfree(multi);
318 spin_lock(&sdev->stat_lock);
319 ++sdev->stat.corrected_errors;
320 spin_unlock(&sdev->stat_lock);
321
322 if (printk_ratelimit())
323 printk(KERN_ERR "btrfs: fixed up at %llu\n",
324 (unsigned long long)logical);
325 return;
326
327uncorrectable:
328 kfree(multi);
329 spin_lock(&sdev->stat_lock);
330 ++sdev->stat.uncorrectable_errors;
331 spin_unlock(&sdev->stat_lock);
332
333 if (printk_ratelimit())
334 printk(KERN_ERR "btrfs: unable to fixup at %llu\n",
335 (unsigned long long)logical);
336}
337
338static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
339 struct page *page)
340{
341 struct bio *bio = NULL;
342 int ret;
343 DECLARE_COMPLETION_ONSTACK(complete);
344
345 bio = bio_alloc(GFP_NOFS, 1);
346 bio->bi_bdev = bdev;
347 bio->bi_sector = sector;
348 bio_add_page(bio, page, PAGE_SIZE, 0);
349 bio->bi_end_io = scrub_fixup_end_io;
350 bio->bi_private = &complete;
351 submit_bio(rw, bio);
352
353 /* this will also unplug the queue */
354 wait_for_completion(&complete);
355
356 ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
357 bio_put(bio);
358 return ret;
359}
360
361static void scrub_bio_end_io(struct bio *bio, int err)
362{
363 struct scrub_bio *sbio = bio->bi_private;
364 struct scrub_dev *sdev = sbio->sdev;
365 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
366
367 sbio->err = err;
368 sbio->bio = bio;
369
370 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
371}
372
373static void scrub_checksum(struct btrfs_work *work)
374{
375 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
376 struct scrub_dev *sdev = sbio->sdev;
377 struct page *page;
378 void *buffer;
379 int i;
380 u64 flags;
381 u64 logical;
382 int ret;
383
384 if (sbio->err) {
385 for (i = 0; i < sbio->count; ++i)
386 scrub_recheck_error(sbio, i);
387
388 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
389 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
390 sbio->bio->bi_phys_segments = 0;
391 sbio->bio->bi_idx = 0;
392
393 for (i = 0; i < sbio->count; i++) {
394 struct bio_vec *bi;
395 bi = &sbio->bio->bi_io_vec[i];
396 bi->bv_offset = 0;
397 bi->bv_len = PAGE_SIZE;
398 }
399
400 spin_lock(&sdev->stat_lock);
401 ++sdev->stat.read_errors;
402 spin_unlock(&sdev->stat_lock);
403 goto out;
404 }
405 for (i = 0; i < sbio->count; ++i) {
406 page = sbio->bio->bi_io_vec[i].bv_page;
407 buffer = kmap_atomic(page, KM_USER0);
408 flags = sbio->spag[i].flags;
409 logical = sbio->logical + i * PAGE_SIZE;
410 ret = 0;
411 if (flags & BTRFS_EXTENT_FLAG_DATA) {
412 ret = scrub_checksum_data(sdev, sbio->spag + i, buffer);
413 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
414 ret = scrub_checksum_tree_block(sdev, sbio->spag + i,
415 logical, buffer);
416 } else if (flags & BTRFS_EXTENT_FLAG_SUPER) {
417 BUG_ON(i);
418 (void)scrub_checksum_super(sbio, buffer);
419 } else {
420 WARN_ON(1);
421 }
422 kunmap_atomic(buffer, KM_USER0);
423 if (ret)
424 scrub_recheck_error(sbio, i);
425 }
426
427out:
428 scrub_free_bio(sbio->bio);
429 sbio->bio = NULL;
430 spin_lock(&sdev->list_lock);
431 sbio->next_free = sdev->first_free;
432 sdev->first_free = sbio->index;
433 spin_unlock(&sdev->list_lock);
434 atomic_dec(&sdev->in_flight);
435 wake_up(&sdev->list_wait);
436}
437
438static int scrub_checksum_data(struct scrub_dev *sdev,
439 struct scrub_page *spag, void *buffer)
440{
441 u8 csum[BTRFS_CSUM_SIZE];
442 u32 crc = ~(u32)0;
443 int fail = 0;
444 struct btrfs_root *root = sdev->dev->dev_root;
445
446 if (!spag->have_csum)
447 return 0;
448
449 crc = btrfs_csum_data(root, buffer, crc, PAGE_SIZE);
450 btrfs_csum_final(crc, csum);
451 if (memcmp(csum, spag->csum, sdev->csum_size))
452 fail = 1;
453
454 spin_lock(&sdev->stat_lock);
455 ++sdev->stat.data_extents_scrubbed;
456 sdev->stat.data_bytes_scrubbed += PAGE_SIZE;
457 if (fail)
458 ++sdev->stat.csum_errors;
459 spin_unlock(&sdev->stat_lock);
460
461 return fail;
462}
463
464static int scrub_checksum_tree_block(struct scrub_dev *sdev,
465 struct scrub_page *spag, u64 logical,
466 void *buffer)
467{
468 struct btrfs_header *h;
469 struct btrfs_root *root = sdev->dev->dev_root;
470 struct btrfs_fs_info *fs_info = root->fs_info;
471 u8 csum[BTRFS_CSUM_SIZE];
472 u32 crc = ~(u32)0;
473 int fail = 0;
474 int crc_fail = 0;
475
476 /*
477 * we don't use the getter functions here, as we
478 * a) don't have an extent buffer and
479 * b) the page is already kmapped
480 */
481 h = (struct btrfs_header *)buffer;
482
483 if (logical != le64_to_cpu(h->bytenr))
484 ++fail;
485
486 if (spag->generation != le64_to_cpu(h->generation))
487 ++fail;
488
489 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
490 ++fail;
491
492 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
493 BTRFS_UUID_SIZE))
494 ++fail;
495
496 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
497 PAGE_SIZE - BTRFS_CSUM_SIZE);
498 btrfs_csum_final(crc, csum);
499 if (memcmp(csum, h->csum, sdev->csum_size))
500 ++crc_fail;
501
502 spin_lock(&sdev->stat_lock);
503 ++sdev->stat.tree_extents_scrubbed;
504 sdev->stat.tree_bytes_scrubbed += PAGE_SIZE;
505 if (crc_fail)
506 ++sdev->stat.csum_errors;
507 if (fail)
508 ++sdev->stat.verify_errors;
509 spin_unlock(&sdev->stat_lock);
510
511 return fail || crc_fail;
512}
513
514static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
515{
516 struct btrfs_super_block *s;
517 u64 logical;
518 struct scrub_dev *sdev = sbio->sdev;
519 struct btrfs_root *root = sdev->dev->dev_root;
520 struct btrfs_fs_info *fs_info = root->fs_info;
521 u8 csum[BTRFS_CSUM_SIZE];
522 u32 crc = ~(u32)0;
523 int fail = 0;
524
525 s = (struct btrfs_super_block *)buffer;
526 logical = sbio->logical;
527
528 if (logical != le64_to_cpu(s->bytenr))
529 ++fail;
530
531 if (sbio->spag[0].generation != le64_to_cpu(s->generation))
532 ++fail;
533
534 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
535 ++fail;
536
537 crc = btrfs_csum_data(root, buffer + BTRFS_CSUM_SIZE, crc,
538 PAGE_SIZE - BTRFS_CSUM_SIZE);
539 btrfs_csum_final(crc, csum);
540 if (memcmp(csum, s->csum, sbio->sdev->csum_size))
541 ++fail;
542
543 if (fail) {
544 /*
545 * if we find an error in a super block, we just report it.
546 * They will get written with the next transaction commit
547 * anyway
548 */
549 spin_lock(&sdev->stat_lock);
550 ++sdev->stat.super_errors;
551 spin_unlock(&sdev->stat_lock);
552 }
553
554 return fail;
555}
556
557static int scrub_submit(struct scrub_dev *sdev)
558{
559 struct scrub_bio *sbio;
560 struct bio *bio;
561 int i;
562
563 if (sdev->curr == -1)
564 return 0;
565
566 sbio = sdev->bios[sdev->curr];
567
568 bio = bio_alloc(GFP_NOFS, sbio->count);
569 if (!bio)
570 goto nomem;
571
572 bio->bi_private = sbio;
573 bio->bi_end_io = scrub_bio_end_io;
574 bio->bi_bdev = sdev->dev->bdev;
575 bio->bi_sector = sbio->physical >> 9;
576
577 for (i = 0; i < sbio->count; ++i) {
578 struct page *page;
579 int ret;
580
581 page = alloc_page(GFP_NOFS);
582 if (!page)
583 goto nomem;
584
585 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
586 if (!ret) {
587 __free_page(page);
588 goto nomem;
589 }
590 }
591
592 sbio->err = 0;
593 sdev->curr = -1;
594 atomic_inc(&sdev->in_flight);
595
596 submit_bio(READ, bio);
597
598 return 0;
599
600nomem:
601 scrub_free_bio(bio);
602
603 return -ENOMEM;
604}
605
606static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
607 u64 physical, u64 flags, u64 gen, u64 mirror_num,
608 u8 *csum, int force)
609{
610 struct scrub_bio *sbio;
611
612again:
613 /*
614 * grab a fresh bio or wait for one to become available
615 */
616 while (sdev->curr == -1) {
617 spin_lock(&sdev->list_lock);
618 sdev->curr = sdev->first_free;
619 if (sdev->curr != -1) {
620 sdev->first_free = sdev->bios[sdev->curr]->next_free;
621 sdev->bios[sdev->curr]->next_free = -1;
622 sdev->bios[sdev->curr]->count = 0;
623 spin_unlock(&sdev->list_lock);
624 } else {
625 spin_unlock(&sdev->list_lock);
626 wait_event(sdev->list_wait, sdev->first_free != -1);
627 }
628 }
629 sbio = sdev->bios[sdev->curr];
630 if (sbio->count == 0) {
631 sbio->physical = physical;
632 sbio->logical = logical;
633 } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
634 sbio->logical + sbio->count * PAGE_SIZE != logical) {
635 int ret;
636
637 ret = scrub_submit(sdev);
638 if (ret)
639 return ret;
640 goto again;
641 }
642 sbio->spag[sbio->count].flags = flags;
643 sbio->spag[sbio->count].generation = gen;
644 sbio->spag[sbio->count].have_csum = 0;
645 sbio->spag[sbio->count].mirror_num = mirror_num;
646 if (csum) {
647 sbio->spag[sbio->count].have_csum = 1;
648 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
649 }
650 ++sbio->count;
651 if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
652 int ret;
653
654 ret = scrub_submit(sdev);
655 if (ret)
656 return ret;
657 }
658
659 return 0;
660}
661
662static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
663 u8 *csum)
664{
665 struct btrfs_ordered_sum *sum = NULL;
666 int ret = 0;
667 unsigned long i;
668 unsigned long num_sectors;
669 u32 sectorsize = sdev->dev->dev_root->sectorsize;
670
671 while (!list_empty(&sdev->csum_list)) {
672 sum = list_first_entry(&sdev->csum_list,
673 struct btrfs_ordered_sum, list);
674 if (sum->bytenr > logical)
675 return 0;
676 if (sum->bytenr + sum->len > logical)
677 break;
678
679 ++sdev->stat.csum_discards;
680 list_del(&sum->list);
681 kfree(sum);
682 sum = NULL;
683 }
684 if (!sum)
685 return 0;
686
687 num_sectors = sum->len / sectorsize;
688 for (i = 0; i < num_sectors; ++i) {
689 if (sum->sums[i].bytenr == logical) {
690 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
691 ret = 1;
692 break;
693 }
694 }
695 if (ret && i == num_sectors - 1) {
696 list_del(&sum->list);
697 kfree(sum);
698 }
699 return ret;
700}
701
702/* scrub extent tries to collect up to 64 kB for each bio */
703static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
704 u64 physical, u64 flags, u64 gen, u64 mirror_num)
705{
706 int ret;
707 u8 csum[BTRFS_CSUM_SIZE];
708
709 while (len) {
710 u64 l = min_t(u64, len, PAGE_SIZE);
711 int have_csum = 0;
712
713 if (flags & BTRFS_EXTENT_FLAG_DATA) {
714 /* push csums to sbio */
715 have_csum = scrub_find_csum(sdev, logical, l, csum);
716 if (have_csum == 0)
717 ++sdev->stat.no_csum;
718 }
719 ret = scrub_page(sdev, logical, l, physical, flags, gen,
720 mirror_num, have_csum ? csum : NULL, 0);
721 if (ret)
722 return ret;
723 len -= l;
724 logical += l;
725 physical += l;
726 }
727 return 0;
728}
729
730static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
731 struct map_lookup *map, int num, u64 base, u64 length)
732{
733 struct btrfs_path *path;
734 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
735 struct btrfs_root *root = fs_info->extent_root;
736 struct btrfs_root *csum_root = fs_info->csum_root;
737 struct btrfs_extent_item *extent;
738 struct blk_plug plug;
739 u64 flags;
740 int ret;
741 int slot;
742 int i;
743 u64 nstripes;
744 int start_stripe;
745 struct extent_buffer *l;
746 struct btrfs_key key;
747 u64 physical;
748 u64 logical;
749 u64 generation;
750 u64 mirror_num;
751
752 u64 increment = map->stripe_len;
753 u64 offset;
754
755 nstripes = length;
756 offset = 0;
757 do_div(nstripes, map->stripe_len);
758 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
759 offset = map->stripe_len * num;
760 increment = map->stripe_len * map->num_stripes;
761 mirror_num = 0;
762 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
763 int factor = map->num_stripes / map->sub_stripes;
764 offset = map->stripe_len * (num / map->sub_stripes);
765 increment = map->stripe_len * factor;
766 mirror_num = num % map->sub_stripes;
767 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
768 increment = map->stripe_len;
769 mirror_num = num % map->num_stripes;
770 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
771 increment = map->stripe_len;
772 mirror_num = num % map->num_stripes;
773 } else {
774 increment = map->stripe_len;
775 mirror_num = 0;
776 }
777
778 path = btrfs_alloc_path();
779 if (!path)
780 return -ENOMEM;
781
782 path->reada = 2;
783 path->search_commit_root = 1;
784 path->skip_locking = 1;
785
786 /*
787 * find all extents for each stripe and just read them to get
788 * them into the page cache
789 * FIXME: we can do better. build a more intelligent prefetching
790 */
791 logical = base + offset;
792 physical = map->stripes[num].physical;
793 ret = 0;
794 for (i = 0; i < nstripes; ++i) {
795 key.objectid = logical;
796 key.type = BTRFS_EXTENT_ITEM_KEY;
797 key.offset = (u64)0;
798
799 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
800 if (ret < 0)
801 goto out_noplug;
802
803 /*
804 * we might miss half an extent here, but that doesn't matter,
805 * as it's only the prefetch
806 */
807 while (1) {
808 l = path->nodes[0];
809 slot = path->slots[0];
810 if (slot >= btrfs_header_nritems(l)) {
811 ret = btrfs_next_leaf(root, path);
812 if (ret == 0)
813 continue;
814 if (ret < 0)
815 goto out_noplug;
816
817 break;
818 }
819 btrfs_item_key_to_cpu(l, &key, slot);
820
821 if (key.objectid >= logical + map->stripe_len)
822 break;
823
824 path->slots[0]++;
825 }
826 btrfs_release_path(path);
827 logical += increment;
828 physical += map->stripe_len;
829 cond_resched();
830 }
831
832 /*
833 * collect all data csums for the stripe to avoid seeking during
834 * the scrub. This might currently (crc32) end up to be about 1MB
835 */
836 start_stripe = 0;
837 blk_start_plug(&plug);
838again:
839 logical = base + offset + start_stripe * increment;
840 for (i = start_stripe; i < nstripes; ++i) {
841 ret = btrfs_lookup_csums_range(csum_root, logical,
842 logical + map->stripe_len - 1,
843 &sdev->csum_list, 1);
844 if (ret)
845 goto out;
846
847 logical += increment;
848 cond_resched();
849 }
850 /*
851 * now find all extents for each stripe and scrub them
852 */
853 logical = base + offset + start_stripe * increment;
854 physical = map->stripes[num].physical + start_stripe * map->stripe_len;
855 ret = 0;
856 for (i = start_stripe; i < nstripes; ++i) {
857 /*
858 * canceled?
859 */
860 if (atomic_read(&fs_info->scrub_cancel_req) ||
861 atomic_read(&sdev->cancel_req)) {
862 ret = -ECANCELED;
863 goto out;
864 }
865 /*
866 * check to see if we have to pause
867 */
868 if (atomic_read(&fs_info->scrub_pause_req)) {
869 /* push queued extents */
870 scrub_submit(sdev);
871 wait_event(sdev->list_wait,
872 atomic_read(&sdev->in_flight) == 0);
873 atomic_inc(&fs_info->scrubs_paused);
874 wake_up(&fs_info->scrub_pause_wait);
875 mutex_lock(&fs_info->scrub_lock);
876 while (atomic_read(&fs_info->scrub_pause_req)) {
877 mutex_unlock(&fs_info->scrub_lock);
878 wait_event(fs_info->scrub_pause_wait,
879 atomic_read(&fs_info->scrub_pause_req) == 0);
880 mutex_lock(&fs_info->scrub_lock);
881 }
882 atomic_dec(&fs_info->scrubs_paused);
883 mutex_unlock(&fs_info->scrub_lock);
884 wake_up(&fs_info->scrub_pause_wait);
885 scrub_free_csums(sdev);
886 start_stripe = i;
887 goto again;
888 }
889
890 key.objectid = logical;
891 key.type = BTRFS_EXTENT_ITEM_KEY;
892 key.offset = (u64)0;
893
894 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
895 if (ret < 0)
896 goto out;
897 if (ret > 0) {
898 ret = btrfs_previous_item(root, path, 0,
899 BTRFS_EXTENT_ITEM_KEY);
900 if (ret < 0)
901 goto out;
902 if (ret > 0) {
903 /* there's no smaller item, so stick with the
904 * larger one */
905 btrfs_release_path(path);
906 ret = btrfs_search_slot(NULL, root, &key,
907 path, 0, 0);
908 if (ret < 0)
909 goto out;
910 }
911 }
912
913 while (1) {
914 l = path->nodes[0];
915 slot = path->slots[0];
916 if (slot >= btrfs_header_nritems(l)) {
917 ret = btrfs_next_leaf(root, path);
918 if (ret == 0)
919 continue;
920 if (ret < 0)
921 goto out;
922
923 break;
924 }
925 btrfs_item_key_to_cpu(l, &key, slot);
926
927 if (key.objectid + key.offset <= logical)
928 goto next;
929
930 if (key.objectid >= logical + map->stripe_len)
931 break;
932
933 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
934 goto next;
935
936 extent = btrfs_item_ptr(l, slot,
937 struct btrfs_extent_item);
938 flags = btrfs_extent_flags(l, extent);
939 generation = btrfs_extent_generation(l, extent);
940
941 if (key.objectid < logical &&
942 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
943 printk(KERN_ERR
944 "btrfs scrub: tree block %llu spanning "
945 "stripes, ignored. logical=%llu\n",
946 (unsigned long long)key.objectid,
947 (unsigned long long)logical);
948 goto next;
949 }
950
951 /*
952 * trim extent to this stripe
953 */
954 if (key.objectid < logical) {
955 key.offset -= logical - key.objectid;
956 key.objectid = logical;
957 }
958 if (key.objectid + key.offset >
959 logical + map->stripe_len) {
960 key.offset = logical + map->stripe_len -
961 key.objectid;
962 }
963
964 ret = scrub_extent(sdev, key.objectid, key.offset,
965 key.objectid - logical + physical,
966 flags, generation, mirror_num);
967 if (ret)
968 goto out;
969
970next:
971 path->slots[0]++;
972 }
973 btrfs_release_path(path);
974 logical += increment;
975 physical += map->stripe_len;
976 spin_lock(&sdev->stat_lock);
977 sdev->stat.last_physical = physical;
978 spin_unlock(&sdev->stat_lock);
979 }
980 /* push queued extents */
981 scrub_submit(sdev);
982
983out:
984 blk_finish_plug(&plug);
985out_noplug:
986 btrfs_free_path(path);
987 return ret < 0 ? ret : 0;
988}
989
990static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
991 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length)
992{
993 struct btrfs_mapping_tree *map_tree =
994 &sdev->dev->dev_root->fs_info->mapping_tree;
995 struct map_lookup *map;
996 struct extent_map *em;
997 int i;
998 int ret = -EINVAL;
999
1000 read_lock(&map_tree->map_tree.lock);
1001 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
1002 read_unlock(&map_tree->map_tree.lock);
1003
1004 if (!em)
1005 return -EINVAL;
1006
1007 map = (struct map_lookup *)em->bdev;
1008 if (em->start != chunk_offset)
1009 goto out;
1010
1011 if (em->len < length)
1012 goto out;
1013
1014 for (i = 0; i < map->num_stripes; ++i) {
1015 if (map->stripes[i].dev == sdev->dev) {
1016 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
1017 if (ret)
1018 goto out;
1019 }
1020 }
1021out:
1022 free_extent_map(em);
1023
1024 return ret;
1025}
1026
1027static noinline_for_stack
1028int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
1029{
1030 struct btrfs_dev_extent *dev_extent = NULL;
1031 struct btrfs_path *path;
1032 struct btrfs_root *root = sdev->dev->dev_root;
1033 struct btrfs_fs_info *fs_info = root->fs_info;
1034 u64 length;
1035 u64 chunk_tree;
1036 u64 chunk_objectid;
1037 u64 chunk_offset;
1038 int ret;
1039 int slot;
1040 struct extent_buffer *l;
1041 struct btrfs_key key;
1042 struct btrfs_key found_key;
1043 struct btrfs_block_group_cache *cache;
1044
1045 path = btrfs_alloc_path();
1046 if (!path)
1047 return -ENOMEM;
1048
1049 path->reada = 2;
1050 path->search_commit_root = 1;
1051 path->skip_locking = 1;
1052
1053 key.objectid = sdev->dev->devid;
1054 key.offset = 0ull;
1055 key.type = BTRFS_DEV_EXTENT_KEY;
1056
1057
1058 while (1) {
1059 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1060 if (ret < 0)
1061 break;
1062 if (ret > 0) {
1063 if (path->slots[0] >=
1064 btrfs_header_nritems(path->nodes[0])) {
1065 ret = btrfs_next_leaf(root, path);
1066 if (ret)
1067 break;
1068 }
1069 }
1070
1071 l = path->nodes[0];
1072 slot = path->slots[0];
1073
1074 btrfs_item_key_to_cpu(l, &found_key, slot);
1075
1076 if (found_key.objectid != sdev->dev->devid)
1077 break;
1078
1079 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
1080 break;
1081
1082 if (found_key.offset >= end)
1083 break;
1084
1085 if (found_key.offset < key.offset)
1086 break;
1087
1088 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1089 length = btrfs_dev_extent_length(l, dev_extent);
1090
1091 if (found_key.offset + length <= start) {
1092 key.offset = found_key.offset + length;
1093 btrfs_release_path(path);
1094 continue;
1095 }
1096
1097 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1098 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1099 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1100
1101 /*
1102 * get a reference on the corresponding block group to prevent
1103 * the chunk from going away while we scrub it
1104 */
1105 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
1106 if (!cache) {
1107 ret = -ENOENT;
1108 break;
1109 }
1110 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
1111 chunk_offset, length);
1112 btrfs_put_block_group(cache);
1113 if (ret)
1114 break;
1115
1116 key.offset = found_key.offset + length;
1117 btrfs_release_path(path);
1118 }
1119
1120 btrfs_free_path(path);
1121
1122 /*
1123 * ret can still be 1 from search_slot or next_leaf,
1124 * that's not an error
1125 */
1126 return ret < 0 ? ret : 0;
1127}
1128
1129static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
1130{
1131 int i;
1132 u64 bytenr;
1133 u64 gen;
1134 int ret;
1135 struct btrfs_device *device = sdev->dev;
1136 struct btrfs_root *root = device->dev_root;
1137
1138 gen = root->fs_info->last_trans_committed;
1139
1140 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1141 bytenr = btrfs_sb_offset(i);
1142 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
1143 break;
1144
1145 ret = scrub_page(sdev, bytenr, PAGE_SIZE, bytenr,
1146 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
1147 if (ret)
1148 return ret;
1149 }
1150 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1151
1152 return 0;
1153}
1154
1155/*
1156 * get a reference count on fs_info->scrub_workers. start worker if necessary
1157 */
1158static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
1159{
1160 struct btrfs_fs_info *fs_info = root->fs_info;
1161
1162 mutex_lock(&fs_info->scrub_lock);
1163 if (fs_info->scrub_workers_refcnt == 0) {
1164 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
1165 fs_info->thread_pool_size, &fs_info->generic_worker);
1166 fs_info->scrub_workers.idle_thresh = 4;
1167 btrfs_start_workers(&fs_info->scrub_workers, 1);
1168 }
1169 ++fs_info->scrub_workers_refcnt;
1170 mutex_unlock(&fs_info->scrub_lock);
1171
1172 return 0;
1173}
1174
1175static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
1176{
1177 struct btrfs_fs_info *fs_info = root->fs_info;
1178
1179 mutex_lock(&fs_info->scrub_lock);
1180 if (--fs_info->scrub_workers_refcnt == 0)
1181 btrfs_stop_workers(&fs_info->scrub_workers);
1182 WARN_ON(fs_info->scrub_workers_refcnt < 0);
1183 mutex_unlock(&fs_info->scrub_lock);
1184}
1185
1186
1187int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
1188 struct btrfs_scrub_progress *progress, int readonly)
1189{
1190 struct scrub_dev *sdev;
1191 struct btrfs_fs_info *fs_info = root->fs_info;
1192 int ret;
1193 struct btrfs_device *dev;
1194
1195 if (btrfs_fs_closing(root->fs_info))
1196 return -EINVAL;
1197
1198 /*
1199 * check some assumptions
1200 */
1201 if (root->sectorsize != PAGE_SIZE ||
1202 root->sectorsize != root->leafsize ||
1203 root->sectorsize != root->nodesize) {
1204 printk(KERN_ERR "btrfs_scrub: size assumptions fail\n");
1205 return -EINVAL;
1206 }
1207
1208 ret = scrub_workers_get(root);
1209 if (ret)
1210 return ret;
1211
1212 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1213 dev = btrfs_find_device(root, devid, NULL, NULL);
1214 if (!dev || dev->missing) {
1215 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1216 scrub_workers_put(root);
1217 return -ENODEV;
1218 }
1219 mutex_lock(&fs_info->scrub_lock);
1220
1221 if (!dev->in_fs_metadata) {
1222 mutex_unlock(&fs_info->scrub_lock);
1223 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1224 scrub_workers_put(root);
1225 return -ENODEV;
1226 }
1227
1228 if (dev->scrub_device) {
1229 mutex_unlock(&fs_info->scrub_lock);
1230 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1231 scrub_workers_put(root);
1232 return -EINPROGRESS;
1233 }
1234 sdev = scrub_setup_dev(dev);
1235 if (IS_ERR(sdev)) {
1236 mutex_unlock(&fs_info->scrub_lock);
1237 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1238 scrub_workers_put(root);
1239 return PTR_ERR(sdev);
1240 }
1241 sdev->readonly = readonly;
1242 dev->scrub_device = sdev;
1243
1244 atomic_inc(&fs_info->scrubs_running);
1245 mutex_unlock(&fs_info->scrub_lock);
1246 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1247
1248 down_read(&fs_info->scrub_super_lock);
1249 ret = scrub_supers(sdev);
1250 up_read(&fs_info->scrub_super_lock);
1251
1252 if (!ret)
1253 ret = scrub_enumerate_chunks(sdev, start, end);
1254
1255 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
1256
1257 atomic_dec(&fs_info->scrubs_running);
1258 wake_up(&fs_info->scrub_pause_wait);
1259
1260 if (progress)
1261 memcpy(progress, &sdev->stat, sizeof(*progress));
1262
1263 mutex_lock(&fs_info->scrub_lock);
1264 dev->scrub_device = NULL;
1265 mutex_unlock(&fs_info->scrub_lock);
1266
1267 scrub_free_dev(sdev);
1268 scrub_workers_put(root);
1269
1270 return ret;
1271}
1272
1273int btrfs_scrub_pause(struct btrfs_root *root)
1274{
1275 struct btrfs_fs_info *fs_info = root->fs_info;
1276
1277 mutex_lock(&fs_info->scrub_lock);
1278 atomic_inc(&fs_info->scrub_pause_req);
1279 while (atomic_read(&fs_info->scrubs_paused) !=
1280 atomic_read(&fs_info->scrubs_running)) {
1281 mutex_unlock(&fs_info->scrub_lock);
1282 wait_event(fs_info->scrub_pause_wait,
1283 atomic_read(&fs_info->scrubs_paused) ==
1284 atomic_read(&fs_info->scrubs_running));
1285 mutex_lock(&fs_info->scrub_lock);
1286 }
1287 mutex_unlock(&fs_info->scrub_lock);
1288
1289 return 0;
1290}
1291
1292int btrfs_scrub_continue(struct btrfs_root *root)
1293{
1294 struct btrfs_fs_info *fs_info = root->fs_info;
1295
1296 atomic_dec(&fs_info->scrub_pause_req);
1297 wake_up(&fs_info->scrub_pause_wait);
1298 return 0;
1299}
1300
1301int btrfs_scrub_pause_super(struct btrfs_root *root)
1302{
1303 down_write(&root->fs_info->scrub_super_lock);
1304 return 0;
1305}
1306
1307int btrfs_scrub_continue_super(struct btrfs_root *root)
1308{
1309 up_write(&root->fs_info->scrub_super_lock);
1310 return 0;
1311}
1312
1313int btrfs_scrub_cancel(struct btrfs_root *root)
1314{
1315 struct btrfs_fs_info *fs_info = root->fs_info;
1316
1317 mutex_lock(&fs_info->scrub_lock);
1318 if (!atomic_read(&fs_info->scrubs_running)) {
1319 mutex_unlock(&fs_info->scrub_lock);
1320 return -ENOTCONN;
1321 }
1322
1323 atomic_inc(&fs_info->scrub_cancel_req);
1324 while (atomic_read(&fs_info->scrubs_running)) {
1325 mutex_unlock(&fs_info->scrub_lock);
1326 wait_event(fs_info->scrub_pause_wait,
1327 atomic_read(&fs_info->scrubs_running) == 0);
1328 mutex_lock(&fs_info->scrub_lock);
1329 }
1330 atomic_dec(&fs_info->scrub_cancel_req);
1331 mutex_unlock(&fs_info->scrub_lock);
1332
1333 return 0;
1334}
1335
1336int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
1337{
1338 struct btrfs_fs_info *fs_info = root->fs_info;
1339 struct scrub_dev *sdev;
1340
1341 mutex_lock(&fs_info->scrub_lock);
1342 sdev = dev->scrub_device;
1343 if (!sdev) {
1344 mutex_unlock(&fs_info->scrub_lock);
1345 return -ENOTCONN;
1346 }
1347 atomic_inc(&sdev->cancel_req);
1348 while (dev->scrub_device) {
1349 mutex_unlock(&fs_info->scrub_lock);
1350 wait_event(fs_info->scrub_pause_wait,
1351 dev->scrub_device == NULL);
1352 mutex_lock(&fs_info->scrub_lock);
1353 }
1354 mutex_unlock(&fs_info->scrub_lock);
1355
1356 return 0;
1357}
1358int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
1359{
1360 struct btrfs_fs_info *fs_info = root->fs_info;
1361 struct btrfs_device *dev;
1362 int ret;
1363
1364 /*
1365 * we have to hold the device_list_mutex here so the device
1366 * does not go away in cancel_dev. FIXME: find a better solution
1367 */
1368 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1369 dev = btrfs_find_device(root, devid, NULL, NULL);
1370 if (!dev) {
1371 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1372 return -ENODEV;
1373 }
1374 ret = btrfs_scrub_cancel_dev(root, dev);
1375 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1376
1377 return ret;
1378}
1379
1380int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
1381 struct btrfs_scrub_progress *progress)
1382{
1383 struct btrfs_device *dev;
1384 struct scrub_dev *sdev = NULL;
1385
1386 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1387 dev = btrfs_find_device(root, devid, NULL, NULL);
1388 if (dev)
1389 sdev = dev->scrub_device;
1390 if (sdev)
1391 memcpy(progress, &sdev->stat, sizeof(*progress));
1392 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1393
1394 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
1395}
1/*
2 * Copyright (C) 2011, 2012 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#include "dev-replace.h"
29#include "check-integrity.h"
30#include "rcu-string.h"
31#include "raid56.h"
32
33/*
34 * This is only the first step towards a full-features scrub. It reads all
35 * extent and super block and verifies the checksums. In case a bad checksum
36 * is found or the extent cannot be read, good data will be written back if
37 * any can be found.
38 *
39 * Future enhancements:
40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
42 * - track and record media errors, throw out bad devices
43 * - add a mode to also read unallocated space
44 */
45
46struct scrub_block;
47struct scrub_ctx;
48
49/*
50 * the following three values only influence the performance.
51 * The last one configures the number of parallel and outstanding I/O
52 * operations. The first two values configure an upper limit for the number
53 * of (dynamically allocated) pages that are added to a bio.
54 */
55#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
56#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
57#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
58
59/*
60 * the following value times PAGE_SIZE needs to be large enough to match the
61 * largest node/leaf/sector size that shall be supported.
62 * Values larger than BTRFS_STRIPE_LEN are not supported.
63 */
64#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
65
66struct scrub_page {
67 struct scrub_block *sblock;
68 struct page *page;
69 struct btrfs_device *dev;
70 u64 flags; /* extent flags */
71 u64 generation;
72 u64 logical;
73 u64 physical;
74 u64 physical_for_dev_replace;
75 atomic_t ref_count;
76 struct {
77 unsigned int mirror_num:8;
78 unsigned int have_csum:1;
79 unsigned int io_error:1;
80 };
81 u8 csum[BTRFS_CSUM_SIZE];
82};
83
84struct scrub_bio {
85 int index;
86 struct scrub_ctx *sctx;
87 struct btrfs_device *dev;
88 struct bio *bio;
89 int err;
90 u64 logical;
91 u64 physical;
92#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
93 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
94#else
95 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
96#endif
97 int page_count;
98 int next_free;
99 struct btrfs_work work;
100};
101
102struct scrub_block {
103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
104 int page_count;
105 atomic_t outstanding_pages;
106 atomic_t ref_count; /* free mem on transition to zero */
107 struct scrub_ctx *sctx;
108 struct {
109 unsigned int header_error:1;
110 unsigned int checksum_error:1;
111 unsigned int no_io_error_seen:1;
112 unsigned int generation_error:1; /* also sets header_error */
113 };
114};
115
116struct scrub_wr_ctx {
117 struct scrub_bio *wr_curr_bio;
118 struct btrfs_device *tgtdev;
119 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
120 atomic_t flush_all_writes;
121 struct mutex wr_lock;
122};
123
124struct scrub_ctx {
125 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
126 struct btrfs_root *dev_root;
127 int first_free;
128 int curr;
129 atomic_t bios_in_flight;
130 atomic_t workers_pending;
131 spinlock_t list_lock;
132 wait_queue_head_t list_wait;
133 u16 csum_size;
134 struct list_head csum_list;
135 atomic_t cancel_req;
136 int readonly;
137 int pages_per_rd_bio;
138 u32 sectorsize;
139 u32 nodesize;
140 u32 leafsize;
141
142 int is_dev_replace;
143 struct scrub_wr_ctx wr_ctx;
144
145 /*
146 * statistics
147 */
148 struct btrfs_scrub_progress stat;
149 spinlock_t stat_lock;
150};
151
152struct scrub_fixup_nodatasum {
153 struct scrub_ctx *sctx;
154 struct btrfs_device *dev;
155 u64 logical;
156 struct btrfs_root *root;
157 struct btrfs_work work;
158 int mirror_num;
159};
160
161struct scrub_nocow_inode {
162 u64 inum;
163 u64 offset;
164 u64 root;
165 struct list_head list;
166};
167
168struct scrub_copy_nocow_ctx {
169 struct scrub_ctx *sctx;
170 u64 logical;
171 u64 len;
172 int mirror_num;
173 u64 physical_for_dev_replace;
174 struct list_head inodes;
175 struct btrfs_work work;
176};
177
178struct scrub_warning {
179 struct btrfs_path *path;
180 u64 extent_item_size;
181 char *scratch_buf;
182 char *msg_buf;
183 const char *errstr;
184 sector_t sector;
185 u64 logical;
186 struct btrfs_device *dev;
187 int msg_bufsize;
188 int scratch_bufsize;
189};
190
191
192static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
193static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
194static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
195static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
196static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
197static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
198 struct btrfs_fs_info *fs_info,
199 struct scrub_block *original_sblock,
200 u64 length, u64 logical,
201 struct scrub_block *sblocks_for_recheck);
202static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
203 struct scrub_block *sblock, int is_metadata,
204 int have_csum, u8 *csum, u64 generation,
205 u16 csum_size);
206static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
207 struct scrub_block *sblock,
208 int is_metadata, int have_csum,
209 const u8 *csum, u64 generation,
210 u16 csum_size);
211static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
212 struct scrub_block *sblock_good,
213 int force_write);
214static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
215 struct scrub_block *sblock_good,
216 int page_num, int force_write);
217static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
218static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
219 int page_num);
220static int scrub_checksum_data(struct scrub_block *sblock);
221static int scrub_checksum_tree_block(struct scrub_block *sblock);
222static int scrub_checksum_super(struct scrub_block *sblock);
223static void scrub_block_get(struct scrub_block *sblock);
224static void scrub_block_put(struct scrub_block *sblock);
225static void scrub_page_get(struct scrub_page *spage);
226static void scrub_page_put(struct scrub_page *spage);
227static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
228 struct scrub_page *spage);
229static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
230 u64 physical, struct btrfs_device *dev, u64 flags,
231 u64 gen, int mirror_num, u8 *csum, int force,
232 u64 physical_for_dev_replace);
233static void scrub_bio_end_io(struct bio *bio, int err);
234static void scrub_bio_end_io_worker(struct btrfs_work *work);
235static void scrub_block_complete(struct scrub_block *sblock);
236static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
237 u64 extent_logical, u64 extent_len,
238 u64 *extent_physical,
239 struct btrfs_device **extent_dev,
240 int *extent_mirror_num);
241static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
242 struct scrub_wr_ctx *wr_ctx,
243 struct btrfs_fs_info *fs_info,
244 struct btrfs_device *dev,
245 int is_dev_replace);
246static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
247static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
248 struct scrub_page *spage);
249static void scrub_wr_submit(struct scrub_ctx *sctx);
250static void scrub_wr_bio_end_io(struct bio *bio, int err);
251static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
252static int write_page_nocow(struct scrub_ctx *sctx,
253 u64 physical_for_dev_replace, struct page *page);
254static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
255 struct scrub_copy_nocow_ctx *ctx);
256static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
257 int mirror_num, u64 physical_for_dev_replace);
258static void copy_nocow_pages_worker(struct btrfs_work *work);
259static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
260static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
261
262
263static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
264{
265 atomic_inc(&sctx->bios_in_flight);
266}
267
268static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
269{
270 atomic_dec(&sctx->bios_in_flight);
271 wake_up(&sctx->list_wait);
272}
273
274static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
275{
276 while (atomic_read(&fs_info->scrub_pause_req)) {
277 mutex_unlock(&fs_info->scrub_lock);
278 wait_event(fs_info->scrub_pause_wait,
279 atomic_read(&fs_info->scrub_pause_req) == 0);
280 mutex_lock(&fs_info->scrub_lock);
281 }
282}
283
284static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
285{
286 atomic_inc(&fs_info->scrubs_paused);
287 wake_up(&fs_info->scrub_pause_wait);
288
289 mutex_lock(&fs_info->scrub_lock);
290 __scrub_blocked_if_needed(fs_info);
291 atomic_dec(&fs_info->scrubs_paused);
292 mutex_unlock(&fs_info->scrub_lock);
293
294 wake_up(&fs_info->scrub_pause_wait);
295}
296
297/*
298 * used for workers that require transaction commits (i.e., for the
299 * NOCOW case)
300 */
301static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
302{
303 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
304
305 /*
306 * increment scrubs_running to prevent cancel requests from
307 * completing as long as a worker is running. we must also
308 * increment scrubs_paused to prevent deadlocking on pause
309 * requests used for transactions commits (as the worker uses a
310 * transaction context). it is safe to regard the worker
311 * as paused for all matters practical. effectively, we only
312 * avoid cancellation requests from completing.
313 */
314 mutex_lock(&fs_info->scrub_lock);
315 atomic_inc(&fs_info->scrubs_running);
316 atomic_inc(&fs_info->scrubs_paused);
317 mutex_unlock(&fs_info->scrub_lock);
318
319 /*
320 * check if @scrubs_running=@scrubs_paused condition
321 * inside wait_event() is not an atomic operation.
322 * which means we may inc/dec @scrub_running/paused
323 * at any time. Let's wake up @scrub_pause_wait as
324 * much as we can to let commit transaction blocked less.
325 */
326 wake_up(&fs_info->scrub_pause_wait);
327
328 atomic_inc(&sctx->workers_pending);
329}
330
331/* used for workers that require transaction commits */
332static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
333{
334 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
335
336 /*
337 * see scrub_pending_trans_workers_inc() why we're pretending
338 * to be paused in the scrub counters
339 */
340 mutex_lock(&fs_info->scrub_lock);
341 atomic_dec(&fs_info->scrubs_running);
342 atomic_dec(&fs_info->scrubs_paused);
343 mutex_unlock(&fs_info->scrub_lock);
344 atomic_dec(&sctx->workers_pending);
345 wake_up(&fs_info->scrub_pause_wait);
346 wake_up(&sctx->list_wait);
347}
348
349static void scrub_free_csums(struct scrub_ctx *sctx)
350{
351 while (!list_empty(&sctx->csum_list)) {
352 struct btrfs_ordered_sum *sum;
353 sum = list_first_entry(&sctx->csum_list,
354 struct btrfs_ordered_sum, list);
355 list_del(&sum->list);
356 kfree(sum);
357 }
358}
359
360static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
361{
362 int i;
363
364 if (!sctx)
365 return;
366
367 scrub_free_wr_ctx(&sctx->wr_ctx);
368
369 /* this can happen when scrub is cancelled */
370 if (sctx->curr != -1) {
371 struct scrub_bio *sbio = sctx->bios[sctx->curr];
372
373 for (i = 0; i < sbio->page_count; i++) {
374 WARN_ON(!sbio->pagev[i]->page);
375 scrub_block_put(sbio->pagev[i]->sblock);
376 }
377 bio_put(sbio->bio);
378 }
379
380 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
381 struct scrub_bio *sbio = sctx->bios[i];
382
383 if (!sbio)
384 break;
385 kfree(sbio);
386 }
387
388 scrub_free_csums(sctx);
389 kfree(sctx);
390}
391
392static noinline_for_stack
393struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
394{
395 struct scrub_ctx *sctx;
396 int i;
397 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
398 int pages_per_rd_bio;
399 int ret;
400
401 /*
402 * the setting of pages_per_rd_bio is correct for scrub but might
403 * be wrong for the dev_replace code where we might read from
404 * different devices in the initial huge bios. However, that
405 * code is able to correctly handle the case when adding a page
406 * to a bio fails.
407 */
408 if (dev->bdev)
409 pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
410 bio_get_nr_vecs(dev->bdev));
411 else
412 pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
413 sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
414 if (!sctx)
415 goto nomem;
416 sctx->is_dev_replace = is_dev_replace;
417 sctx->pages_per_rd_bio = pages_per_rd_bio;
418 sctx->curr = -1;
419 sctx->dev_root = dev->dev_root;
420 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
421 struct scrub_bio *sbio;
422
423 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
424 if (!sbio)
425 goto nomem;
426 sctx->bios[i] = sbio;
427
428 sbio->index = i;
429 sbio->sctx = sctx;
430 sbio->page_count = 0;
431 btrfs_init_work(&sbio->work, scrub_bio_end_io_worker,
432 NULL, NULL);
433
434 if (i != SCRUB_BIOS_PER_SCTX - 1)
435 sctx->bios[i]->next_free = i + 1;
436 else
437 sctx->bios[i]->next_free = -1;
438 }
439 sctx->first_free = 0;
440 sctx->nodesize = dev->dev_root->nodesize;
441 sctx->leafsize = dev->dev_root->leafsize;
442 sctx->sectorsize = dev->dev_root->sectorsize;
443 atomic_set(&sctx->bios_in_flight, 0);
444 atomic_set(&sctx->workers_pending, 0);
445 atomic_set(&sctx->cancel_req, 0);
446 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
447 INIT_LIST_HEAD(&sctx->csum_list);
448
449 spin_lock_init(&sctx->list_lock);
450 spin_lock_init(&sctx->stat_lock);
451 init_waitqueue_head(&sctx->list_wait);
452
453 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
454 fs_info->dev_replace.tgtdev, is_dev_replace);
455 if (ret) {
456 scrub_free_ctx(sctx);
457 return ERR_PTR(ret);
458 }
459 return sctx;
460
461nomem:
462 scrub_free_ctx(sctx);
463 return ERR_PTR(-ENOMEM);
464}
465
466static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
467 void *warn_ctx)
468{
469 u64 isize;
470 u32 nlink;
471 int ret;
472 int i;
473 struct extent_buffer *eb;
474 struct btrfs_inode_item *inode_item;
475 struct scrub_warning *swarn = warn_ctx;
476 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
477 struct inode_fs_paths *ipath = NULL;
478 struct btrfs_root *local_root;
479 struct btrfs_key root_key;
480
481 root_key.objectid = root;
482 root_key.type = BTRFS_ROOT_ITEM_KEY;
483 root_key.offset = (u64)-1;
484 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
485 if (IS_ERR(local_root)) {
486 ret = PTR_ERR(local_root);
487 goto err;
488 }
489
490 ret = inode_item_info(inum, 0, local_root, swarn->path);
491 if (ret) {
492 btrfs_release_path(swarn->path);
493 goto err;
494 }
495
496 eb = swarn->path->nodes[0];
497 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
498 struct btrfs_inode_item);
499 isize = btrfs_inode_size(eb, inode_item);
500 nlink = btrfs_inode_nlink(eb, inode_item);
501 btrfs_release_path(swarn->path);
502
503 ipath = init_ipath(4096, local_root, swarn->path);
504 if (IS_ERR(ipath)) {
505 ret = PTR_ERR(ipath);
506 ipath = NULL;
507 goto err;
508 }
509 ret = paths_from_inode(inum, ipath);
510
511 if (ret < 0)
512 goto err;
513
514 /*
515 * we deliberately ignore the bit ipath might have been too small to
516 * hold all of the paths here
517 */
518 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
519 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
520 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
521 "length %llu, links %u (path: %s)\n", swarn->errstr,
522 swarn->logical, rcu_str_deref(swarn->dev->name),
523 (unsigned long long)swarn->sector, root, inum, offset,
524 min(isize - offset, (u64)PAGE_SIZE), nlink,
525 (char *)(unsigned long)ipath->fspath->val[i]);
526
527 free_ipath(ipath);
528 return 0;
529
530err:
531 printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
532 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
533 "resolving failed with ret=%d\n", swarn->errstr,
534 swarn->logical, rcu_str_deref(swarn->dev->name),
535 (unsigned long long)swarn->sector, root, inum, offset, ret);
536
537 free_ipath(ipath);
538 return 0;
539}
540
541static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
542{
543 struct btrfs_device *dev;
544 struct btrfs_fs_info *fs_info;
545 struct btrfs_path *path;
546 struct btrfs_key found_key;
547 struct extent_buffer *eb;
548 struct btrfs_extent_item *ei;
549 struct scrub_warning swarn;
550 unsigned long ptr = 0;
551 u64 extent_item_pos;
552 u64 flags = 0;
553 u64 ref_root;
554 u32 item_size;
555 u8 ref_level;
556 const int bufsize = 4096;
557 int ret;
558
559 WARN_ON(sblock->page_count < 1);
560 dev = sblock->pagev[0]->dev;
561 fs_info = sblock->sctx->dev_root->fs_info;
562
563 path = btrfs_alloc_path();
564
565 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
566 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
567 swarn.sector = (sblock->pagev[0]->physical) >> 9;
568 swarn.logical = sblock->pagev[0]->logical;
569 swarn.errstr = errstr;
570 swarn.dev = NULL;
571 swarn.msg_bufsize = bufsize;
572 swarn.scratch_bufsize = bufsize;
573
574 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
575 goto out;
576
577 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
578 &flags);
579 if (ret < 0)
580 goto out;
581
582 extent_item_pos = swarn.logical - found_key.objectid;
583 swarn.extent_item_size = found_key.offset;
584
585 eb = path->nodes[0];
586 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
587 item_size = btrfs_item_size_nr(eb, path->slots[0]);
588
589 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
590 do {
591 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
592 &ref_root, &ref_level);
593 printk_in_rcu(KERN_WARNING
594 "BTRFS: %s at logical %llu on dev %s, "
595 "sector %llu: metadata %s (level %d) in tree "
596 "%llu\n", errstr, swarn.logical,
597 rcu_str_deref(dev->name),
598 (unsigned long long)swarn.sector,
599 ref_level ? "node" : "leaf",
600 ret < 0 ? -1 : ref_level,
601 ret < 0 ? -1 : ref_root);
602 } while (ret != 1);
603 btrfs_release_path(path);
604 } else {
605 btrfs_release_path(path);
606 swarn.path = path;
607 swarn.dev = dev;
608 iterate_extent_inodes(fs_info, found_key.objectid,
609 extent_item_pos, 1,
610 scrub_print_warning_inode, &swarn);
611 }
612
613out:
614 btrfs_free_path(path);
615 kfree(swarn.scratch_buf);
616 kfree(swarn.msg_buf);
617}
618
619static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
620{
621 struct page *page = NULL;
622 unsigned long index;
623 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
624 int ret;
625 int corrected = 0;
626 struct btrfs_key key;
627 struct inode *inode = NULL;
628 struct btrfs_fs_info *fs_info;
629 u64 end = offset + PAGE_SIZE - 1;
630 struct btrfs_root *local_root;
631 int srcu_index;
632
633 key.objectid = root;
634 key.type = BTRFS_ROOT_ITEM_KEY;
635 key.offset = (u64)-1;
636
637 fs_info = fixup->root->fs_info;
638 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
639
640 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
641 if (IS_ERR(local_root)) {
642 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
643 return PTR_ERR(local_root);
644 }
645
646 key.type = BTRFS_INODE_ITEM_KEY;
647 key.objectid = inum;
648 key.offset = 0;
649 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
650 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
651 if (IS_ERR(inode))
652 return PTR_ERR(inode);
653
654 index = offset >> PAGE_CACHE_SHIFT;
655
656 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
657 if (!page) {
658 ret = -ENOMEM;
659 goto out;
660 }
661
662 if (PageUptodate(page)) {
663 if (PageDirty(page)) {
664 /*
665 * we need to write the data to the defect sector. the
666 * data that was in that sector is not in memory,
667 * because the page was modified. we must not write the
668 * modified page to that sector.
669 *
670 * TODO: what could be done here: wait for the delalloc
671 * runner to write out that page (might involve
672 * COW) and see whether the sector is still
673 * referenced afterwards.
674 *
675 * For the meantime, we'll treat this error
676 * incorrectable, although there is a chance that a
677 * later scrub will find the bad sector again and that
678 * there's no dirty page in memory, then.
679 */
680 ret = -EIO;
681 goto out;
682 }
683 fs_info = BTRFS_I(inode)->root->fs_info;
684 ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
685 fixup->logical, page,
686 fixup->mirror_num);
687 unlock_page(page);
688 corrected = !ret;
689 } else {
690 /*
691 * we need to get good data first. the general readpage path
692 * will call repair_io_failure for us, we just have to make
693 * sure we read the bad mirror.
694 */
695 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
696 EXTENT_DAMAGED, GFP_NOFS);
697 if (ret) {
698 /* set_extent_bits should give proper error */
699 WARN_ON(ret > 0);
700 if (ret > 0)
701 ret = -EFAULT;
702 goto out;
703 }
704
705 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
706 btrfs_get_extent,
707 fixup->mirror_num);
708 wait_on_page_locked(page);
709
710 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
711 end, EXTENT_DAMAGED, 0, NULL);
712 if (!corrected)
713 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
714 EXTENT_DAMAGED, GFP_NOFS);
715 }
716
717out:
718 if (page)
719 put_page(page);
720 if (inode)
721 iput(inode);
722
723 if (ret < 0)
724 return ret;
725
726 if (ret == 0 && corrected) {
727 /*
728 * we only need to call readpage for one of the inodes belonging
729 * to this extent. so make iterate_extent_inodes stop
730 */
731 return 1;
732 }
733
734 return -EIO;
735}
736
737static void scrub_fixup_nodatasum(struct btrfs_work *work)
738{
739 int ret;
740 struct scrub_fixup_nodatasum *fixup;
741 struct scrub_ctx *sctx;
742 struct btrfs_trans_handle *trans = NULL;
743 struct btrfs_path *path;
744 int uncorrectable = 0;
745
746 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
747 sctx = fixup->sctx;
748
749 path = btrfs_alloc_path();
750 if (!path) {
751 spin_lock(&sctx->stat_lock);
752 ++sctx->stat.malloc_errors;
753 spin_unlock(&sctx->stat_lock);
754 uncorrectable = 1;
755 goto out;
756 }
757
758 trans = btrfs_join_transaction(fixup->root);
759 if (IS_ERR(trans)) {
760 uncorrectable = 1;
761 goto out;
762 }
763
764 /*
765 * the idea is to trigger a regular read through the standard path. we
766 * read a page from the (failed) logical address by specifying the
767 * corresponding copynum of the failed sector. thus, that readpage is
768 * expected to fail.
769 * that is the point where on-the-fly error correction will kick in
770 * (once it's finished) and rewrite the failed sector if a good copy
771 * can be found.
772 */
773 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
774 path, scrub_fixup_readpage,
775 fixup);
776 if (ret < 0) {
777 uncorrectable = 1;
778 goto out;
779 }
780 WARN_ON(ret != 1);
781
782 spin_lock(&sctx->stat_lock);
783 ++sctx->stat.corrected_errors;
784 spin_unlock(&sctx->stat_lock);
785
786out:
787 if (trans && !IS_ERR(trans))
788 btrfs_end_transaction(trans, fixup->root);
789 if (uncorrectable) {
790 spin_lock(&sctx->stat_lock);
791 ++sctx->stat.uncorrectable_errors;
792 spin_unlock(&sctx->stat_lock);
793 btrfs_dev_replace_stats_inc(
794 &sctx->dev_root->fs_info->dev_replace.
795 num_uncorrectable_read_errors);
796 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
797 "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
798 fixup->logical, rcu_str_deref(fixup->dev->name));
799 }
800
801 btrfs_free_path(path);
802 kfree(fixup);
803
804 scrub_pending_trans_workers_dec(sctx);
805}
806
807/*
808 * scrub_handle_errored_block gets called when either verification of the
809 * pages failed or the bio failed to read, e.g. with EIO. In the latter
810 * case, this function handles all pages in the bio, even though only one
811 * may be bad.
812 * The goal of this function is to repair the errored block by using the
813 * contents of one of the mirrors.
814 */
815static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
816{
817 struct scrub_ctx *sctx = sblock_to_check->sctx;
818 struct btrfs_device *dev;
819 struct btrfs_fs_info *fs_info;
820 u64 length;
821 u64 logical;
822 u64 generation;
823 unsigned int failed_mirror_index;
824 unsigned int is_metadata;
825 unsigned int have_csum;
826 u8 *csum;
827 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
828 struct scrub_block *sblock_bad;
829 int ret;
830 int mirror_index;
831 int page_num;
832 int success;
833 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
834 DEFAULT_RATELIMIT_BURST);
835
836 BUG_ON(sblock_to_check->page_count < 1);
837 fs_info = sctx->dev_root->fs_info;
838 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
839 /*
840 * if we find an error in a super block, we just report it.
841 * They will get written with the next transaction commit
842 * anyway
843 */
844 spin_lock(&sctx->stat_lock);
845 ++sctx->stat.super_errors;
846 spin_unlock(&sctx->stat_lock);
847 return 0;
848 }
849 length = sblock_to_check->page_count * PAGE_SIZE;
850 logical = sblock_to_check->pagev[0]->logical;
851 generation = sblock_to_check->pagev[0]->generation;
852 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
853 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
854 is_metadata = !(sblock_to_check->pagev[0]->flags &
855 BTRFS_EXTENT_FLAG_DATA);
856 have_csum = sblock_to_check->pagev[0]->have_csum;
857 csum = sblock_to_check->pagev[0]->csum;
858 dev = sblock_to_check->pagev[0]->dev;
859
860 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
861 sblocks_for_recheck = NULL;
862 goto nodatasum_case;
863 }
864
865 /*
866 * read all mirrors one after the other. This includes to
867 * re-read the extent or metadata block that failed (that was
868 * the cause that this fixup code is called) another time,
869 * page by page this time in order to know which pages
870 * caused I/O errors and which ones are good (for all mirrors).
871 * It is the goal to handle the situation when more than one
872 * mirror contains I/O errors, but the errors do not
873 * overlap, i.e. the data can be repaired by selecting the
874 * pages from those mirrors without I/O error on the
875 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
876 * would be that mirror #1 has an I/O error on the first page,
877 * the second page is good, and mirror #2 has an I/O error on
878 * the second page, but the first page is good.
879 * Then the first page of the first mirror can be repaired by
880 * taking the first page of the second mirror, and the
881 * second page of the second mirror can be repaired by
882 * copying the contents of the 2nd page of the 1st mirror.
883 * One more note: if the pages of one mirror contain I/O
884 * errors, the checksum cannot be verified. In order to get
885 * the best data for repairing, the first attempt is to find
886 * a mirror without I/O errors and with a validated checksum.
887 * Only if this is not possible, the pages are picked from
888 * mirrors with I/O errors without considering the checksum.
889 * If the latter is the case, at the end, the checksum of the
890 * repaired area is verified in order to correctly maintain
891 * the statistics.
892 */
893
894 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
895 sizeof(*sblocks_for_recheck),
896 GFP_NOFS);
897 if (!sblocks_for_recheck) {
898 spin_lock(&sctx->stat_lock);
899 sctx->stat.malloc_errors++;
900 sctx->stat.read_errors++;
901 sctx->stat.uncorrectable_errors++;
902 spin_unlock(&sctx->stat_lock);
903 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
904 goto out;
905 }
906
907 /* setup the context, map the logical blocks and alloc the pages */
908 ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
909 logical, sblocks_for_recheck);
910 if (ret) {
911 spin_lock(&sctx->stat_lock);
912 sctx->stat.read_errors++;
913 sctx->stat.uncorrectable_errors++;
914 spin_unlock(&sctx->stat_lock);
915 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
916 goto out;
917 }
918 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
919 sblock_bad = sblocks_for_recheck + failed_mirror_index;
920
921 /* build and submit the bios for the failed mirror, check checksums */
922 scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
923 csum, generation, sctx->csum_size);
924
925 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
926 sblock_bad->no_io_error_seen) {
927 /*
928 * the error disappeared after reading page by page, or
929 * the area was part of a huge bio and other parts of the
930 * bio caused I/O errors, or the block layer merged several
931 * read requests into one and the error is caused by a
932 * different bio (usually one of the two latter cases is
933 * the cause)
934 */
935 spin_lock(&sctx->stat_lock);
936 sctx->stat.unverified_errors++;
937 spin_unlock(&sctx->stat_lock);
938
939 if (sctx->is_dev_replace)
940 scrub_write_block_to_dev_replace(sblock_bad);
941 goto out;
942 }
943
944 if (!sblock_bad->no_io_error_seen) {
945 spin_lock(&sctx->stat_lock);
946 sctx->stat.read_errors++;
947 spin_unlock(&sctx->stat_lock);
948 if (__ratelimit(&_rs))
949 scrub_print_warning("i/o error", sblock_to_check);
950 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
951 } else if (sblock_bad->checksum_error) {
952 spin_lock(&sctx->stat_lock);
953 sctx->stat.csum_errors++;
954 spin_unlock(&sctx->stat_lock);
955 if (__ratelimit(&_rs))
956 scrub_print_warning("checksum error", sblock_to_check);
957 btrfs_dev_stat_inc_and_print(dev,
958 BTRFS_DEV_STAT_CORRUPTION_ERRS);
959 } else if (sblock_bad->header_error) {
960 spin_lock(&sctx->stat_lock);
961 sctx->stat.verify_errors++;
962 spin_unlock(&sctx->stat_lock);
963 if (__ratelimit(&_rs))
964 scrub_print_warning("checksum/header error",
965 sblock_to_check);
966 if (sblock_bad->generation_error)
967 btrfs_dev_stat_inc_and_print(dev,
968 BTRFS_DEV_STAT_GENERATION_ERRS);
969 else
970 btrfs_dev_stat_inc_and_print(dev,
971 BTRFS_DEV_STAT_CORRUPTION_ERRS);
972 }
973
974 if (sctx->readonly) {
975 ASSERT(!sctx->is_dev_replace);
976 goto out;
977 }
978
979 if (!is_metadata && !have_csum) {
980 struct scrub_fixup_nodatasum *fixup_nodatasum;
981
982nodatasum_case:
983 WARN_ON(sctx->is_dev_replace);
984
985 /*
986 * !is_metadata and !have_csum, this means that the data
987 * might not be COW'ed, that it might be modified
988 * concurrently. The general strategy to work on the
989 * commit root does not help in the case when COW is not
990 * used.
991 */
992 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
993 if (!fixup_nodatasum)
994 goto did_not_correct_error;
995 fixup_nodatasum->sctx = sctx;
996 fixup_nodatasum->dev = dev;
997 fixup_nodatasum->logical = logical;
998 fixup_nodatasum->root = fs_info->extent_root;
999 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1000 scrub_pending_trans_workers_inc(sctx);
1001 btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum,
1002 NULL, NULL);
1003 btrfs_queue_work(fs_info->scrub_workers,
1004 &fixup_nodatasum->work);
1005 goto out;
1006 }
1007
1008 /*
1009 * now build and submit the bios for the other mirrors, check
1010 * checksums.
1011 * First try to pick the mirror which is completely without I/O
1012 * errors and also does not have a checksum error.
1013 * If one is found, and if a checksum is present, the full block
1014 * that is known to contain an error is rewritten. Afterwards
1015 * the block is known to be corrected.
1016 * If a mirror is found which is completely correct, and no
1017 * checksum is present, only those pages are rewritten that had
1018 * an I/O error in the block to be repaired, since it cannot be
1019 * determined, which copy of the other pages is better (and it
1020 * could happen otherwise that a correct page would be
1021 * overwritten by a bad one).
1022 */
1023 for (mirror_index = 0;
1024 mirror_index < BTRFS_MAX_MIRRORS &&
1025 sblocks_for_recheck[mirror_index].page_count > 0;
1026 mirror_index++) {
1027 struct scrub_block *sblock_other;
1028
1029 if (mirror_index == failed_mirror_index)
1030 continue;
1031 sblock_other = sblocks_for_recheck + mirror_index;
1032
1033 /* build and submit the bios, check checksums */
1034 scrub_recheck_block(fs_info, sblock_other, is_metadata,
1035 have_csum, csum, generation,
1036 sctx->csum_size);
1037
1038 if (!sblock_other->header_error &&
1039 !sblock_other->checksum_error &&
1040 sblock_other->no_io_error_seen) {
1041 if (sctx->is_dev_replace) {
1042 scrub_write_block_to_dev_replace(sblock_other);
1043 } else {
1044 int force_write = is_metadata || have_csum;
1045
1046 ret = scrub_repair_block_from_good_copy(
1047 sblock_bad, sblock_other,
1048 force_write);
1049 }
1050 if (0 == ret)
1051 goto corrected_error;
1052 }
1053 }
1054
1055 /*
1056 * for dev_replace, pick good pages and write to the target device.
1057 */
1058 if (sctx->is_dev_replace) {
1059 success = 1;
1060 for (page_num = 0; page_num < sblock_bad->page_count;
1061 page_num++) {
1062 int sub_success;
1063
1064 sub_success = 0;
1065 for (mirror_index = 0;
1066 mirror_index < BTRFS_MAX_MIRRORS &&
1067 sblocks_for_recheck[mirror_index].page_count > 0;
1068 mirror_index++) {
1069 struct scrub_block *sblock_other =
1070 sblocks_for_recheck + mirror_index;
1071 struct scrub_page *page_other =
1072 sblock_other->pagev[page_num];
1073
1074 if (!page_other->io_error) {
1075 ret = scrub_write_page_to_dev_replace(
1076 sblock_other, page_num);
1077 if (ret == 0) {
1078 /* succeeded for this page */
1079 sub_success = 1;
1080 break;
1081 } else {
1082 btrfs_dev_replace_stats_inc(
1083 &sctx->dev_root->
1084 fs_info->dev_replace.
1085 num_write_errors);
1086 }
1087 }
1088 }
1089
1090 if (!sub_success) {
1091 /*
1092 * did not find a mirror to fetch the page
1093 * from. scrub_write_page_to_dev_replace()
1094 * handles this case (page->io_error), by
1095 * filling the block with zeros before
1096 * submitting the write request
1097 */
1098 success = 0;
1099 ret = scrub_write_page_to_dev_replace(
1100 sblock_bad, page_num);
1101 if (ret)
1102 btrfs_dev_replace_stats_inc(
1103 &sctx->dev_root->fs_info->
1104 dev_replace.num_write_errors);
1105 }
1106 }
1107
1108 goto out;
1109 }
1110
1111 /*
1112 * for regular scrub, repair those pages that are errored.
1113 * In case of I/O errors in the area that is supposed to be
1114 * repaired, continue by picking good copies of those pages.
1115 * Select the good pages from mirrors to rewrite bad pages from
1116 * the area to fix. Afterwards verify the checksum of the block
1117 * that is supposed to be repaired. This verification step is
1118 * only done for the purpose of statistic counting and for the
1119 * final scrub report, whether errors remain.
1120 * A perfect algorithm could make use of the checksum and try
1121 * all possible combinations of pages from the different mirrors
1122 * until the checksum verification succeeds. For example, when
1123 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1124 * of mirror #2 is readable but the final checksum test fails,
1125 * then the 2nd page of mirror #3 could be tried, whether now
1126 * the final checksum succeedes. But this would be a rare
1127 * exception and is therefore not implemented. At least it is
1128 * avoided that the good copy is overwritten.
1129 * A more useful improvement would be to pick the sectors
1130 * without I/O error based on sector sizes (512 bytes on legacy
1131 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1132 * mirror could be repaired by taking 512 byte of a different
1133 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1134 * area are unreadable.
1135 */
1136
1137 /* can only fix I/O errors from here on */
1138 if (sblock_bad->no_io_error_seen)
1139 goto did_not_correct_error;
1140
1141 success = 1;
1142 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1143 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1144
1145 if (!page_bad->io_error)
1146 continue;
1147
1148 for (mirror_index = 0;
1149 mirror_index < BTRFS_MAX_MIRRORS &&
1150 sblocks_for_recheck[mirror_index].page_count > 0;
1151 mirror_index++) {
1152 struct scrub_block *sblock_other = sblocks_for_recheck +
1153 mirror_index;
1154 struct scrub_page *page_other = sblock_other->pagev[
1155 page_num];
1156
1157 if (!page_other->io_error) {
1158 ret = scrub_repair_page_from_good_copy(
1159 sblock_bad, sblock_other, page_num, 0);
1160 if (0 == ret) {
1161 page_bad->io_error = 0;
1162 break; /* succeeded for this page */
1163 }
1164 }
1165 }
1166
1167 if (page_bad->io_error) {
1168 /* did not find a mirror to copy the page from */
1169 success = 0;
1170 }
1171 }
1172
1173 if (success) {
1174 if (is_metadata || have_csum) {
1175 /*
1176 * need to verify the checksum now that all
1177 * sectors on disk are repaired (the write
1178 * request for data to be repaired is on its way).
1179 * Just be lazy and use scrub_recheck_block()
1180 * which re-reads the data before the checksum
1181 * is verified, but most likely the data comes out
1182 * of the page cache.
1183 */
1184 scrub_recheck_block(fs_info, sblock_bad,
1185 is_metadata, have_csum, csum,
1186 generation, sctx->csum_size);
1187 if (!sblock_bad->header_error &&
1188 !sblock_bad->checksum_error &&
1189 sblock_bad->no_io_error_seen)
1190 goto corrected_error;
1191 else
1192 goto did_not_correct_error;
1193 } else {
1194corrected_error:
1195 spin_lock(&sctx->stat_lock);
1196 sctx->stat.corrected_errors++;
1197 spin_unlock(&sctx->stat_lock);
1198 printk_ratelimited_in_rcu(KERN_ERR
1199 "BTRFS: fixed up error at logical %llu on dev %s\n",
1200 logical, rcu_str_deref(dev->name));
1201 }
1202 } else {
1203did_not_correct_error:
1204 spin_lock(&sctx->stat_lock);
1205 sctx->stat.uncorrectable_errors++;
1206 spin_unlock(&sctx->stat_lock);
1207 printk_ratelimited_in_rcu(KERN_ERR
1208 "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
1209 logical, rcu_str_deref(dev->name));
1210 }
1211
1212out:
1213 if (sblocks_for_recheck) {
1214 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1215 mirror_index++) {
1216 struct scrub_block *sblock = sblocks_for_recheck +
1217 mirror_index;
1218 int page_index;
1219
1220 for (page_index = 0; page_index < sblock->page_count;
1221 page_index++) {
1222 sblock->pagev[page_index]->sblock = NULL;
1223 scrub_page_put(sblock->pagev[page_index]);
1224 }
1225 }
1226 kfree(sblocks_for_recheck);
1227 }
1228
1229 return 0;
1230}
1231
1232static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
1233 struct btrfs_fs_info *fs_info,
1234 struct scrub_block *original_sblock,
1235 u64 length, u64 logical,
1236 struct scrub_block *sblocks_for_recheck)
1237{
1238 int page_index;
1239 int mirror_index;
1240 int ret;
1241
1242 /*
1243 * note: the two members ref_count and outstanding_pages
1244 * are not used (and not set) in the blocks that are used for
1245 * the recheck procedure
1246 */
1247
1248 page_index = 0;
1249 while (length > 0) {
1250 u64 sublen = min_t(u64, length, PAGE_SIZE);
1251 u64 mapped_length = sublen;
1252 struct btrfs_bio *bbio = NULL;
1253
1254 /*
1255 * with a length of PAGE_SIZE, each returned stripe
1256 * represents one mirror
1257 */
1258 ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
1259 &mapped_length, &bbio, 0);
1260 if (ret || !bbio || mapped_length < sublen) {
1261 kfree(bbio);
1262 return -EIO;
1263 }
1264
1265 BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
1266 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1267 mirror_index++) {
1268 struct scrub_block *sblock;
1269 struct scrub_page *page;
1270
1271 if (mirror_index >= BTRFS_MAX_MIRRORS)
1272 continue;
1273
1274 sblock = sblocks_for_recheck + mirror_index;
1275 sblock->sctx = sctx;
1276 page = kzalloc(sizeof(*page), GFP_NOFS);
1277 if (!page) {
1278leave_nomem:
1279 spin_lock(&sctx->stat_lock);
1280 sctx->stat.malloc_errors++;
1281 spin_unlock(&sctx->stat_lock);
1282 kfree(bbio);
1283 return -ENOMEM;
1284 }
1285 scrub_page_get(page);
1286 sblock->pagev[page_index] = page;
1287 page->logical = logical;
1288 page->physical = bbio->stripes[mirror_index].physical;
1289 BUG_ON(page_index >= original_sblock->page_count);
1290 page->physical_for_dev_replace =
1291 original_sblock->pagev[page_index]->
1292 physical_for_dev_replace;
1293 /* for missing devices, dev->bdev is NULL */
1294 page->dev = bbio->stripes[mirror_index].dev;
1295 page->mirror_num = mirror_index + 1;
1296 sblock->page_count++;
1297 page->page = alloc_page(GFP_NOFS);
1298 if (!page->page)
1299 goto leave_nomem;
1300 }
1301 kfree(bbio);
1302 length -= sublen;
1303 logical += sublen;
1304 page_index++;
1305 }
1306
1307 return 0;
1308}
1309
1310/*
1311 * this function will check the on disk data for checksum errors, header
1312 * errors and read I/O errors. If any I/O errors happen, the exact pages
1313 * which are errored are marked as being bad. The goal is to enable scrub
1314 * to take those pages that are not errored from all the mirrors so that
1315 * the pages that are errored in the just handled mirror can be repaired.
1316 */
1317static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1318 struct scrub_block *sblock, int is_metadata,
1319 int have_csum, u8 *csum, u64 generation,
1320 u16 csum_size)
1321{
1322 int page_num;
1323
1324 sblock->no_io_error_seen = 1;
1325 sblock->header_error = 0;
1326 sblock->checksum_error = 0;
1327
1328 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1329 struct bio *bio;
1330 struct scrub_page *page = sblock->pagev[page_num];
1331
1332 if (page->dev->bdev == NULL) {
1333 page->io_error = 1;
1334 sblock->no_io_error_seen = 0;
1335 continue;
1336 }
1337
1338 WARN_ON(!page->page);
1339 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1340 if (!bio) {
1341 page->io_error = 1;
1342 sblock->no_io_error_seen = 0;
1343 continue;
1344 }
1345 bio->bi_bdev = page->dev->bdev;
1346 bio->bi_iter.bi_sector = page->physical >> 9;
1347
1348 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1349 if (btrfsic_submit_bio_wait(READ, bio))
1350 sblock->no_io_error_seen = 0;
1351
1352 bio_put(bio);
1353 }
1354
1355 if (sblock->no_io_error_seen)
1356 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1357 have_csum, csum, generation,
1358 csum_size);
1359
1360 return;
1361}
1362
1363static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1364 struct scrub_block *sblock,
1365 int is_metadata, int have_csum,
1366 const u8 *csum, u64 generation,
1367 u16 csum_size)
1368{
1369 int page_num;
1370 u8 calculated_csum[BTRFS_CSUM_SIZE];
1371 u32 crc = ~(u32)0;
1372 void *mapped_buffer;
1373
1374 WARN_ON(!sblock->pagev[0]->page);
1375 if (is_metadata) {
1376 struct btrfs_header *h;
1377
1378 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1379 h = (struct btrfs_header *)mapped_buffer;
1380
1381 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
1382 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1383 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1384 BTRFS_UUID_SIZE)) {
1385 sblock->header_error = 1;
1386 } else if (generation != btrfs_stack_header_generation(h)) {
1387 sblock->header_error = 1;
1388 sblock->generation_error = 1;
1389 }
1390 csum = h->csum;
1391 } else {
1392 if (!have_csum)
1393 return;
1394
1395 mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
1396 }
1397
1398 for (page_num = 0;;) {
1399 if (page_num == 0 && is_metadata)
1400 crc = btrfs_csum_data(
1401 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1402 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1403 else
1404 crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
1405
1406 kunmap_atomic(mapped_buffer);
1407 page_num++;
1408 if (page_num >= sblock->page_count)
1409 break;
1410 WARN_ON(!sblock->pagev[page_num]->page);
1411
1412 mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
1413 }
1414
1415 btrfs_csum_final(crc, calculated_csum);
1416 if (memcmp(calculated_csum, csum, csum_size))
1417 sblock->checksum_error = 1;
1418}
1419
1420static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1421 struct scrub_block *sblock_good,
1422 int force_write)
1423{
1424 int page_num;
1425 int ret = 0;
1426
1427 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1428 int ret_sub;
1429
1430 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1431 sblock_good,
1432 page_num,
1433 force_write);
1434 if (ret_sub)
1435 ret = ret_sub;
1436 }
1437
1438 return ret;
1439}
1440
1441static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1442 struct scrub_block *sblock_good,
1443 int page_num, int force_write)
1444{
1445 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1446 struct scrub_page *page_good = sblock_good->pagev[page_num];
1447
1448 BUG_ON(page_bad->page == NULL);
1449 BUG_ON(page_good->page == NULL);
1450 if (force_write || sblock_bad->header_error ||
1451 sblock_bad->checksum_error || page_bad->io_error) {
1452 struct bio *bio;
1453 int ret;
1454
1455 if (!page_bad->dev->bdev) {
1456 printk_ratelimited(KERN_WARNING "BTRFS: "
1457 "scrub_repair_page_from_good_copy(bdev == NULL) "
1458 "is unexpected!\n");
1459 return -EIO;
1460 }
1461
1462 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1463 if (!bio)
1464 return -EIO;
1465 bio->bi_bdev = page_bad->dev->bdev;
1466 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1467
1468 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1469 if (PAGE_SIZE != ret) {
1470 bio_put(bio);
1471 return -EIO;
1472 }
1473
1474 if (btrfsic_submit_bio_wait(WRITE, bio)) {
1475 btrfs_dev_stat_inc_and_print(page_bad->dev,
1476 BTRFS_DEV_STAT_WRITE_ERRS);
1477 btrfs_dev_replace_stats_inc(
1478 &sblock_bad->sctx->dev_root->fs_info->
1479 dev_replace.num_write_errors);
1480 bio_put(bio);
1481 return -EIO;
1482 }
1483 bio_put(bio);
1484 }
1485
1486 return 0;
1487}
1488
1489static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1490{
1491 int page_num;
1492
1493 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1494 int ret;
1495
1496 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1497 if (ret)
1498 btrfs_dev_replace_stats_inc(
1499 &sblock->sctx->dev_root->fs_info->dev_replace.
1500 num_write_errors);
1501 }
1502}
1503
1504static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1505 int page_num)
1506{
1507 struct scrub_page *spage = sblock->pagev[page_num];
1508
1509 BUG_ON(spage->page == NULL);
1510 if (spage->io_error) {
1511 void *mapped_buffer = kmap_atomic(spage->page);
1512
1513 memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
1514 flush_dcache_page(spage->page);
1515 kunmap_atomic(mapped_buffer);
1516 }
1517 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1518}
1519
1520static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1521 struct scrub_page *spage)
1522{
1523 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1524 struct scrub_bio *sbio;
1525 int ret;
1526
1527 mutex_lock(&wr_ctx->wr_lock);
1528again:
1529 if (!wr_ctx->wr_curr_bio) {
1530 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1531 GFP_NOFS);
1532 if (!wr_ctx->wr_curr_bio) {
1533 mutex_unlock(&wr_ctx->wr_lock);
1534 return -ENOMEM;
1535 }
1536 wr_ctx->wr_curr_bio->sctx = sctx;
1537 wr_ctx->wr_curr_bio->page_count = 0;
1538 }
1539 sbio = wr_ctx->wr_curr_bio;
1540 if (sbio->page_count == 0) {
1541 struct bio *bio;
1542
1543 sbio->physical = spage->physical_for_dev_replace;
1544 sbio->logical = spage->logical;
1545 sbio->dev = wr_ctx->tgtdev;
1546 bio = sbio->bio;
1547 if (!bio) {
1548 bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
1549 if (!bio) {
1550 mutex_unlock(&wr_ctx->wr_lock);
1551 return -ENOMEM;
1552 }
1553 sbio->bio = bio;
1554 }
1555
1556 bio->bi_private = sbio;
1557 bio->bi_end_io = scrub_wr_bio_end_io;
1558 bio->bi_bdev = sbio->dev->bdev;
1559 bio->bi_iter.bi_sector = sbio->physical >> 9;
1560 sbio->err = 0;
1561 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1562 spage->physical_for_dev_replace ||
1563 sbio->logical + sbio->page_count * PAGE_SIZE !=
1564 spage->logical) {
1565 scrub_wr_submit(sctx);
1566 goto again;
1567 }
1568
1569 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1570 if (ret != PAGE_SIZE) {
1571 if (sbio->page_count < 1) {
1572 bio_put(sbio->bio);
1573 sbio->bio = NULL;
1574 mutex_unlock(&wr_ctx->wr_lock);
1575 return -EIO;
1576 }
1577 scrub_wr_submit(sctx);
1578 goto again;
1579 }
1580
1581 sbio->pagev[sbio->page_count] = spage;
1582 scrub_page_get(spage);
1583 sbio->page_count++;
1584 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1585 scrub_wr_submit(sctx);
1586 mutex_unlock(&wr_ctx->wr_lock);
1587
1588 return 0;
1589}
1590
1591static void scrub_wr_submit(struct scrub_ctx *sctx)
1592{
1593 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1594 struct scrub_bio *sbio;
1595
1596 if (!wr_ctx->wr_curr_bio)
1597 return;
1598
1599 sbio = wr_ctx->wr_curr_bio;
1600 wr_ctx->wr_curr_bio = NULL;
1601 WARN_ON(!sbio->bio->bi_bdev);
1602 scrub_pending_bio_inc(sctx);
1603 /* process all writes in a single worker thread. Then the block layer
1604 * orders the requests before sending them to the driver which
1605 * doubled the write performance on spinning disks when measured
1606 * with Linux 3.5 */
1607 btrfsic_submit_bio(WRITE, sbio->bio);
1608}
1609
1610static void scrub_wr_bio_end_io(struct bio *bio, int err)
1611{
1612 struct scrub_bio *sbio = bio->bi_private;
1613 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
1614
1615 sbio->err = err;
1616 sbio->bio = bio;
1617
1618 btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
1619 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1620}
1621
1622static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1623{
1624 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1625 struct scrub_ctx *sctx = sbio->sctx;
1626 int i;
1627
1628 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1629 if (sbio->err) {
1630 struct btrfs_dev_replace *dev_replace =
1631 &sbio->sctx->dev_root->fs_info->dev_replace;
1632
1633 for (i = 0; i < sbio->page_count; i++) {
1634 struct scrub_page *spage = sbio->pagev[i];
1635
1636 spage->io_error = 1;
1637 btrfs_dev_replace_stats_inc(&dev_replace->
1638 num_write_errors);
1639 }
1640 }
1641
1642 for (i = 0; i < sbio->page_count; i++)
1643 scrub_page_put(sbio->pagev[i]);
1644
1645 bio_put(sbio->bio);
1646 kfree(sbio);
1647 scrub_pending_bio_dec(sctx);
1648}
1649
1650static int scrub_checksum(struct scrub_block *sblock)
1651{
1652 u64 flags;
1653 int ret;
1654
1655 WARN_ON(sblock->page_count < 1);
1656 flags = sblock->pagev[0]->flags;
1657 ret = 0;
1658 if (flags & BTRFS_EXTENT_FLAG_DATA)
1659 ret = scrub_checksum_data(sblock);
1660 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1661 ret = scrub_checksum_tree_block(sblock);
1662 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1663 (void)scrub_checksum_super(sblock);
1664 else
1665 WARN_ON(1);
1666 if (ret)
1667 scrub_handle_errored_block(sblock);
1668
1669 return ret;
1670}
1671
1672static int scrub_checksum_data(struct scrub_block *sblock)
1673{
1674 struct scrub_ctx *sctx = sblock->sctx;
1675 u8 csum[BTRFS_CSUM_SIZE];
1676 u8 *on_disk_csum;
1677 struct page *page;
1678 void *buffer;
1679 u32 crc = ~(u32)0;
1680 int fail = 0;
1681 u64 len;
1682 int index;
1683
1684 BUG_ON(sblock->page_count < 1);
1685 if (!sblock->pagev[0]->have_csum)
1686 return 0;
1687
1688 on_disk_csum = sblock->pagev[0]->csum;
1689 page = sblock->pagev[0]->page;
1690 buffer = kmap_atomic(page);
1691
1692 len = sctx->sectorsize;
1693 index = 0;
1694 for (;;) {
1695 u64 l = min_t(u64, len, PAGE_SIZE);
1696
1697 crc = btrfs_csum_data(buffer, crc, l);
1698 kunmap_atomic(buffer);
1699 len -= l;
1700 if (len == 0)
1701 break;
1702 index++;
1703 BUG_ON(index >= sblock->page_count);
1704 BUG_ON(!sblock->pagev[index]->page);
1705 page = sblock->pagev[index]->page;
1706 buffer = kmap_atomic(page);
1707 }
1708
1709 btrfs_csum_final(crc, csum);
1710 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1711 fail = 1;
1712
1713 return fail;
1714}
1715
1716static int scrub_checksum_tree_block(struct scrub_block *sblock)
1717{
1718 struct scrub_ctx *sctx = sblock->sctx;
1719 struct btrfs_header *h;
1720 struct btrfs_root *root = sctx->dev_root;
1721 struct btrfs_fs_info *fs_info = root->fs_info;
1722 u8 calculated_csum[BTRFS_CSUM_SIZE];
1723 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1724 struct page *page;
1725 void *mapped_buffer;
1726 u64 mapped_size;
1727 void *p;
1728 u32 crc = ~(u32)0;
1729 int fail = 0;
1730 int crc_fail = 0;
1731 u64 len;
1732 int index;
1733
1734 BUG_ON(sblock->page_count < 1);
1735 page = sblock->pagev[0]->page;
1736 mapped_buffer = kmap_atomic(page);
1737 h = (struct btrfs_header *)mapped_buffer;
1738 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1739
1740 /*
1741 * we don't use the getter functions here, as we
1742 * a) don't have an extent buffer and
1743 * b) the page is already kmapped
1744 */
1745
1746 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1747 ++fail;
1748
1749 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
1750 ++fail;
1751
1752 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1753 ++fail;
1754
1755 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1756 BTRFS_UUID_SIZE))
1757 ++fail;
1758
1759 WARN_ON(sctx->nodesize != sctx->leafsize);
1760 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1761 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1762 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1763 index = 0;
1764 for (;;) {
1765 u64 l = min_t(u64, len, mapped_size);
1766
1767 crc = btrfs_csum_data(p, crc, l);
1768 kunmap_atomic(mapped_buffer);
1769 len -= l;
1770 if (len == 0)
1771 break;
1772 index++;
1773 BUG_ON(index >= sblock->page_count);
1774 BUG_ON(!sblock->pagev[index]->page);
1775 page = sblock->pagev[index]->page;
1776 mapped_buffer = kmap_atomic(page);
1777 mapped_size = PAGE_SIZE;
1778 p = mapped_buffer;
1779 }
1780
1781 btrfs_csum_final(crc, calculated_csum);
1782 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1783 ++crc_fail;
1784
1785 return fail || crc_fail;
1786}
1787
1788static int scrub_checksum_super(struct scrub_block *sblock)
1789{
1790 struct btrfs_super_block *s;
1791 struct scrub_ctx *sctx = sblock->sctx;
1792 struct btrfs_root *root = sctx->dev_root;
1793 struct btrfs_fs_info *fs_info = root->fs_info;
1794 u8 calculated_csum[BTRFS_CSUM_SIZE];
1795 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1796 struct page *page;
1797 void *mapped_buffer;
1798 u64 mapped_size;
1799 void *p;
1800 u32 crc = ~(u32)0;
1801 int fail_gen = 0;
1802 int fail_cor = 0;
1803 u64 len;
1804 int index;
1805
1806 BUG_ON(sblock->page_count < 1);
1807 page = sblock->pagev[0]->page;
1808 mapped_buffer = kmap_atomic(page);
1809 s = (struct btrfs_super_block *)mapped_buffer;
1810 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1811
1812 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1813 ++fail_cor;
1814
1815 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1816 ++fail_gen;
1817
1818 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1819 ++fail_cor;
1820
1821 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1822 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1823 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1824 index = 0;
1825 for (;;) {
1826 u64 l = min_t(u64, len, mapped_size);
1827
1828 crc = btrfs_csum_data(p, crc, l);
1829 kunmap_atomic(mapped_buffer);
1830 len -= l;
1831 if (len == 0)
1832 break;
1833 index++;
1834 BUG_ON(index >= sblock->page_count);
1835 BUG_ON(!sblock->pagev[index]->page);
1836 page = sblock->pagev[index]->page;
1837 mapped_buffer = kmap_atomic(page);
1838 mapped_size = PAGE_SIZE;
1839 p = mapped_buffer;
1840 }
1841
1842 btrfs_csum_final(crc, calculated_csum);
1843 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1844 ++fail_cor;
1845
1846 if (fail_cor + fail_gen) {
1847 /*
1848 * if we find an error in a super block, we just report it.
1849 * They will get written with the next transaction commit
1850 * anyway
1851 */
1852 spin_lock(&sctx->stat_lock);
1853 ++sctx->stat.super_errors;
1854 spin_unlock(&sctx->stat_lock);
1855 if (fail_cor)
1856 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1857 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1858 else
1859 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1860 BTRFS_DEV_STAT_GENERATION_ERRS);
1861 }
1862
1863 return fail_cor + fail_gen;
1864}
1865
1866static void scrub_block_get(struct scrub_block *sblock)
1867{
1868 atomic_inc(&sblock->ref_count);
1869}
1870
1871static void scrub_block_put(struct scrub_block *sblock)
1872{
1873 if (atomic_dec_and_test(&sblock->ref_count)) {
1874 int i;
1875
1876 for (i = 0; i < sblock->page_count; i++)
1877 scrub_page_put(sblock->pagev[i]);
1878 kfree(sblock);
1879 }
1880}
1881
1882static void scrub_page_get(struct scrub_page *spage)
1883{
1884 atomic_inc(&spage->ref_count);
1885}
1886
1887static void scrub_page_put(struct scrub_page *spage)
1888{
1889 if (atomic_dec_and_test(&spage->ref_count)) {
1890 if (spage->page)
1891 __free_page(spage->page);
1892 kfree(spage);
1893 }
1894}
1895
1896static void scrub_submit(struct scrub_ctx *sctx)
1897{
1898 struct scrub_bio *sbio;
1899
1900 if (sctx->curr == -1)
1901 return;
1902
1903 sbio = sctx->bios[sctx->curr];
1904 sctx->curr = -1;
1905 scrub_pending_bio_inc(sctx);
1906
1907 if (!sbio->bio->bi_bdev) {
1908 /*
1909 * this case should not happen. If btrfs_map_block() is
1910 * wrong, it could happen for dev-replace operations on
1911 * missing devices when no mirrors are available, but in
1912 * this case it should already fail the mount.
1913 * This case is handled correctly (but _very_ slowly).
1914 */
1915 printk_ratelimited(KERN_WARNING
1916 "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
1917 bio_endio(sbio->bio, -EIO);
1918 } else {
1919 btrfsic_submit_bio(READ, sbio->bio);
1920 }
1921}
1922
1923static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
1924 struct scrub_page *spage)
1925{
1926 struct scrub_block *sblock = spage->sblock;
1927 struct scrub_bio *sbio;
1928 int ret;
1929
1930again:
1931 /*
1932 * grab a fresh bio or wait for one to become available
1933 */
1934 while (sctx->curr == -1) {
1935 spin_lock(&sctx->list_lock);
1936 sctx->curr = sctx->first_free;
1937 if (sctx->curr != -1) {
1938 sctx->first_free = sctx->bios[sctx->curr]->next_free;
1939 sctx->bios[sctx->curr]->next_free = -1;
1940 sctx->bios[sctx->curr]->page_count = 0;
1941 spin_unlock(&sctx->list_lock);
1942 } else {
1943 spin_unlock(&sctx->list_lock);
1944 wait_event(sctx->list_wait, sctx->first_free != -1);
1945 }
1946 }
1947 sbio = sctx->bios[sctx->curr];
1948 if (sbio->page_count == 0) {
1949 struct bio *bio;
1950
1951 sbio->physical = spage->physical;
1952 sbio->logical = spage->logical;
1953 sbio->dev = spage->dev;
1954 bio = sbio->bio;
1955 if (!bio) {
1956 bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
1957 if (!bio)
1958 return -ENOMEM;
1959 sbio->bio = bio;
1960 }
1961
1962 bio->bi_private = sbio;
1963 bio->bi_end_io = scrub_bio_end_io;
1964 bio->bi_bdev = sbio->dev->bdev;
1965 bio->bi_iter.bi_sector = sbio->physical >> 9;
1966 sbio->err = 0;
1967 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1968 spage->physical ||
1969 sbio->logical + sbio->page_count * PAGE_SIZE !=
1970 spage->logical ||
1971 sbio->dev != spage->dev) {
1972 scrub_submit(sctx);
1973 goto again;
1974 }
1975
1976 sbio->pagev[sbio->page_count] = spage;
1977 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1978 if (ret != PAGE_SIZE) {
1979 if (sbio->page_count < 1) {
1980 bio_put(sbio->bio);
1981 sbio->bio = NULL;
1982 return -EIO;
1983 }
1984 scrub_submit(sctx);
1985 goto again;
1986 }
1987
1988 scrub_block_get(sblock); /* one for the page added to the bio */
1989 atomic_inc(&sblock->outstanding_pages);
1990 sbio->page_count++;
1991 if (sbio->page_count == sctx->pages_per_rd_bio)
1992 scrub_submit(sctx);
1993
1994 return 0;
1995}
1996
1997static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
1998 u64 physical, struct btrfs_device *dev, u64 flags,
1999 u64 gen, int mirror_num, u8 *csum, int force,
2000 u64 physical_for_dev_replace)
2001{
2002 struct scrub_block *sblock;
2003 int index;
2004
2005 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
2006 if (!sblock) {
2007 spin_lock(&sctx->stat_lock);
2008 sctx->stat.malloc_errors++;
2009 spin_unlock(&sctx->stat_lock);
2010 return -ENOMEM;
2011 }
2012
2013 /* one ref inside this function, plus one for each page added to
2014 * a bio later on */
2015 atomic_set(&sblock->ref_count, 1);
2016 sblock->sctx = sctx;
2017 sblock->no_io_error_seen = 1;
2018
2019 for (index = 0; len > 0; index++) {
2020 struct scrub_page *spage;
2021 u64 l = min_t(u64, len, PAGE_SIZE);
2022
2023 spage = kzalloc(sizeof(*spage), GFP_NOFS);
2024 if (!spage) {
2025leave_nomem:
2026 spin_lock(&sctx->stat_lock);
2027 sctx->stat.malloc_errors++;
2028 spin_unlock(&sctx->stat_lock);
2029 scrub_block_put(sblock);
2030 return -ENOMEM;
2031 }
2032 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2033 scrub_page_get(spage);
2034 sblock->pagev[index] = spage;
2035 spage->sblock = sblock;
2036 spage->dev = dev;
2037 spage->flags = flags;
2038 spage->generation = gen;
2039 spage->logical = logical;
2040 spage->physical = physical;
2041 spage->physical_for_dev_replace = physical_for_dev_replace;
2042 spage->mirror_num = mirror_num;
2043 if (csum) {
2044 spage->have_csum = 1;
2045 memcpy(spage->csum, csum, sctx->csum_size);
2046 } else {
2047 spage->have_csum = 0;
2048 }
2049 sblock->page_count++;
2050 spage->page = alloc_page(GFP_NOFS);
2051 if (!spage->page)
2052 goto leave_nomem;
2053 len -= l;
2054 logical += l;
2055 physical += l;
2056 physical_for_dev_replace += l;
2057 }
2058
2059 WARN_ON(sblock->page_count == 0);
2060 for (index = 0; index < sblock->page_count; index++) {
2061 struct scrub_page *spage = sblock->pagev[index];
2062 int ret;
2063
2064 ret = scrub_add_page_to_rd_bio(sctx, spage);
2065 if (ret) {
2066 scrub_block_put(sblock);
2067 return ret;
2068 }
2069 }
2070
2071 if (force)
2072 scrub_submit(sctx);
2073
2074 /* last one frees, either here or in bio completion for last page */
2075 scrub_block_put(sblock);
2076 return 0;
2077}
2078
2079static void scrub_bio_end_io(struct bio *bio, int err)
2080{
2081 struct scrub_bio *sbio = bio->bi_private;
2082 struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
2083
2084 sbio->err = err;
2085 sbio->bio = bio;
2086
2087 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2088}
2089
2090static void scrub_bio_end_io_worker(struct btrfs_work *work)
2091{
2092 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2093 struct scrub_ctx *sctx = sbio->sctx;
2094 int i;
2095
2096 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2097 if (sbio->err) {
2098 for (i = 0; i < sbio->page_count; i++) {
2099 struct scrub_page *spage = sbio->pagev[i];
2100
2101 spage->io_error = 1;
2102 spage->sblock->no_io_error_seen = 0;
2103 }
2104 }
2105
2106 /* now complete the scrub_block items that have all pages completed */
2107 for (i = 0; i < sbio->page_count; i++) {
2108 struct scrub_page *spage = sbio->pagev[i];
2109 struct scrub_block *sblock = spage->sblock;
2110
2111 if (atomic_dec_and_test(&sblock->outstanding_pages))
2112 scrub_block_complete(sblock);
2113 scrub_block_put(sblock);
2114 }
2115
2116 bio_put(sbio->bio);
2117 sbio->bio = NULL;
2118 spin_lock(&sctx->list_lock);
2119 sbio->next_free = sctx->first_free;
2120 sctx->first_free = sbio->index;
2121 spin_unlock(&sctx->list_lock);
2122
2123 if (sctx->is_dev_replace &&
2124 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2125 mutex_lock(&sctx->wr_ctx.wr_lock);
2126 scrub_wr_submit(sctx);
2127 mutex_unlock(&sctx->wr_ctx.wr_lock);
2128 }
2129
2130 scrub_pending_bio_dec(sctx);
2131}
2132
2133static void scrub_block_complete(struct scrub_block *sblock)
2134{
2135 if (!sblock->no_io_error_seen) {
2136 scrub_handle_errored_block(sblock);
2137 } else {
2138 /*
2139 * if has checksum error, write via repair mechanism in
2140 * dev replace case, otherwise write here in dev replace
2141 * case.
2142 */
2143 if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
2144 scrub_write_block_to_dev_replace(sblock);
2145 }
2146}
2147
2148static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
2149 u8 *csum)
2150{
2151 struct btrfs_ordered_sum *sum = NULL;
2152 unsigned long index;
2153 unsigned long num_sectors;
2154
2155 while (!list_empty(&sctx->csum_list)) {
2156 sum = list_first_entry(&sctx->csum_list,
2157 struct btrfs_ordered_sum, list);
2158 if (sum->bytenr > logical)
2159 return 0;
2160 if (sum->bytenr + sum->len > logical)
2161 break;
2162
2163 ++sctx->stat.csum_discards;
2164 list_del(&sum->list);
2165 kfree(sum);
2166 sum = NULL;
2167 }
2168 if (!sum)
2169 return 0;
2170
2171 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2172 num_sectors = sum->len / sctx->sectorsize;
2173 memcpy(csum, sum->sums + index, sctx->csum_size);
2174 if (index == num_sectors - 1) {
2175 list_del(&sum->list);
2176 kfree(sum);
2177 }
2178 return 1;
2179}
2180
2181/* scrub extent tries to collect up to 64 kB for each bio */
2182static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2183 u64 physical, struct btrfs_device *dev, u64 flags,
2184 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2185{
2186 int ret;
2187 u8 csum[BTRFS_CSUM_SIZE];
2188 u32 blocksize;
2189
2190 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2191 blocksize = sctx->sectorsize;
2192 spin_lock(&sctx->stat_lock);
2193 sctx->stat.data_extents_scrubbed++;
2194 sctx->stat.data_bytes_scrubbed += len;
2195 spin_unlock(&sctx->stat_lock);
2196 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2197 WARN_ON(sctx->nodesize != sctx->leafsize);
2198 blocksize = sctx->nodesize;
2199 spin_lock(&sctx->stat_lock);
2200 sctx->stat.tree_extents_scrubbed++;
2201 sctx->stat.tree_bytes_scrubbed += len;
2202 spin_unlock(&sctx->stat_lock);
2203 } else {
2204 blocksize = sctx->sectorsize;
2205 WARN_ON(1);
2206 }
2207
2208 while (len) {
2209 u64 l = min_t(u64, len, blocksize);
2210 int have_csum = 0;
2211
2212 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2213 /* push csums to sbio */
2214 have_csum = scrub_find_csum(sctx, logical, l, csum);
2215 if (have_csum == 0)
2216 ++sctx->stat.no_csum;
2217 if (sctx->is_dev_replace && !have_csum) {
2218 ret = copy_nocow_pages(sctx, logical, l,
2219 mirror_num,
2220 physical_for_dev_replace);
2221 goto behind_scrub_pages;
2222 }
2223 }
2224 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2225 mirror_num, have_csum ? csum : NULL, 0,
2226 physical_for_dev_replace);
2227behind_scrub_pages:
2228 if (ret)
2229 return ret;
2230 len -= l;
2231 logical += l;
2232 physical += l;
2233 physical_for_dev_replace += l;
2234 }
2235 return 0;
2236}
2237
2238/*
2239 * Given a physical address, this will calculate it's
2240 * logical offset. if this is a parity stripe, it will return
2241 * the most left data stripe's logical offset.
2242 *
2243 * return 0 if it is a data stripe, 1 means parity stripe.
2244 */
2245static int get_raid56_logic_offset(u64 physical, int num,
2246 struct map_lookup *map, u64 *offset)
2247{
2248 int i;
2249 int j = 0;
2250 u64 stripe_nr;
2251 u64 last_offset;
2252 int stripe_index;
2253 int rot;
2254
2255 last_offset = (physical - map->stripes[num].physical) *
2256 nr_data_stripes(map);
2257 *offset = last_offset;
2258 for (i = 0; i < nr_data_stripes(map); i++) {
2259 *offset = last_offset + i * map->stripe_len;
2260
2261 stripe_nr = *offset;
2262 do_div(stripe_nr, map->stripe_len);
2263 do_div(stripe_nr, nr_data_stripes(map));
2264
2265 /* Work out the disk rotation on this stripe-set */
2266 rot = do_div(stripe_nr, map->num_stripes);
2267 /* calculate which stripe this data locates */
2268 rot += i;
2269 stripe_index = rot % map->num_stripes;
2270 if (stripe_index == num)
2271 return 0;
2272 if (stripe_index < num)
2273 j++;
2274 }
2275 *offset = last_offset + j * map->stripe_len;
2276 return 1;
2277}
2278
2279static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
2280 struct map_lookup *map,
2281 struct btrfs_device *scrub_dev,
2282 int num, u64 base, u64 length,
2283 int is_dev_replace)
2284{
2285 struct btrfs_path *path;
2286 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
2287 struct btrfs_root *root = fs_info->extent_root;
2288 struct btrfs_root *csum_root = fs_info->csum_root;
2289 struct btrfs_extent_item *extent;
2290 struct blk_plug plug;
2291 u64 flags;
2292 int ret;
2293 int slot;
2294 u64 nstripes;
2295 struct extent_buffer *l;
2296 struct btrfs_key key;
2297 u64 physical;
2298 u64 logical;
2299 u64 logic_end;
2300 u64 physical_end;
2301 u64 generation;
2302 int mirror_num;
2303 struct reada_control *reada1;
2304 struct reada_control *reada2;
2305 struct btrfs_key key_start;
2306 struct btrfs_key key_end;
2307 u64 increment = map->stripe_len;
2308 u64 offset;
2309 u64 extent_logical;
2310 u64 extent_physical;
2311 u64 extent_len;
2312 struct btrfs_device *extent_dev;
2313 int extent_mirror_num;
2314 int stop_loop = 0;
2315
2316 nstripes = length;
2317 physical = map->stripes[num].physical;
2318 offset = 0;
2319 do_div(nstripes, map->stripe_len);
2320 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2321 offset = map->stripe_len * num;
2322 increment = map->stripe_len * map->num_stripes;
2323 mirror_num = 1;
2324 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2325 int factor = map->num_stripes / map->sub_stripes;
2326 offset = map->stripe_len * (num / map->sub_stripes);
2327 increment = map->stripe_len * factor;
2328 mirror_num = num % map->sub_stripes + 1;
2329 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2330 increment = map->stripe_len;
2331 mirror_num = num % map->num_stripes + 1;
2332 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2333 increment = map->stripe_len;
2334 mirror_num = num % map->num_stripes + 1;
2335 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2336 BTRFS_BLOCK_GROUP_RAID6)) {
2337 get_raid56_logic_offset(physical, num, map, &offset);
2338 increment = map->stripe_len * nr_data_stripes(map);
2339 mirror_num = 1;
2340 } else {
2341 increment = map->stripe_len;
2342 mirror_num = 1;
2343 }
2344
2345 path = btrfs_alloc_path();
2346 if (!path)
2347 return -ENOMEM;
2348
2349 /*
2350 * work on commit root. The related disk blocks are static as
2351 * long as COW is applied. This means, it is save to rewrite
2352 * them to repair disk errors without any race conditions
2353 */
2354 path->search_commit_root = 1;
2355 path->skip_locking = 1;
2356
2357 /*
2358 * trigger the readahead for extent tree csum tree and wait for
2359 * completion. During readahead, the scrub is officially paused
2360 * to not hold off transaction commits
2361 */
2362 logical = base + offset;
2363 physical_end = physical + nstripes * map->stripe_len;
2364 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2365 BTRFS_BLOCK_GROUP_RAID6)) {
2366 get_raid56_logic_offset(physical_end, num,
2367 map, &logic_end);
2368 logic_end += base;
2369 } else {
2370 logic_end = logical + increment * nstripes;
2371 }
2372 wait_event(sctx->list_wait,
2373 atomic_read(&sctx->bios_in_flight) == 0);
2374 scrub_blocked_if_needed(fs_info);
2375
2376 /* FIXME it might be better to start readahead at commit root */
2377 key_start.objectid = logical;
2378 key_start.type = BTRFS_EXTENT_ITEM_KEY;
2379 key_start.offset = (u64)0;
2380 key_end.objectid = logic_end;
2381 key_end.type = BTRFS_METADATA_ITEM_KEY;
2382 key_end.offset = (u64)-1;
2383 reada1 = btrfs_reada_add(root, &key_start, &key_end);
2384
2385 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2386 key_start.type = BTRFS_EXTENT_CSUM_KEY;
2387 key_start.offset = logical;
2388 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
2389 key_end.type = BTRFS_EXTENT_CSUM_KEY;
2390 key_end.offset = logic_end;
2391 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
2392
2393 if (!IS_ERR(reada1))
2394 btrfs_reada_wait(reada1);
2395 if (!IS_ERR(reada2))
2396 btrfs_reada_wait(reada2);
2397
2398
2399 /*
2400 * collect all data csums for the stripe to avoid seeking during
2401 * the scrub. This might currently (crc32) end up to be about 1MB
2402 */
2403 blk_start_plug(&plug);
2404
2405 /*
2406 * now find all extents for each stripe and scrub them
2407 */
2408 ret = 0;
2409 while (physical < physical_end) {
2410 /* for raid56, we skip parity stripe */
2411 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2412 BTRFS_BLOCK_GROUP_RAID6)) {
2413 ret = get_raid56_logic_offset(physical, num,
2414 map, &logical);
2415 logical += base;
2416 if (ret)
2417 goto skip;
2418 }
2419 /*
2420 * canceled?
2421 */
2422 if (atomic_read(&fs_info->scrub_cancel_req) ||
2423 atomic_read(&sctx->cancel_req)) {
2424 ret = -ECANCELED;
2425 goto out;
2426 }
2427 /*
2428 * check to see if we have to pause
2429 */
2430 if (atomic_read(&fs_info->scrub_pause_req)) {
2431 /* push queued extents */
2432 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2433 scrub_submit(sctx);
2434 mutex_lock(&sctx->wr_ctx.wr_lock);
2435 scrub_wr_submit(sctx);
2436 mutex_unlock(&sctx->wr_ctx.wr_lock);
2437 wait_event(sctx->list_wait,
2438 atomic_read(&sctx->bios_in_flight) == 0);
2439 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2440 scrub_blocked_if_needed(fs_info);
2441 }
2442
2443 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2444 key.type = BTRFS_METADATA_ITEM_KEY;
2445 else
2446 key.type = BTRFS_EXTENT_ITEM_KEY;
2447 key.objectid = logical;
2448 key.offset = (u64)-1;
2449
2450 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2451 if (ret < 0)
2452 goto out;
2453
2454 if (ret > 0) {
2455 ret = btrfs_previous_extent_item(root, path, 0);
2456 if (ret < 0)
2457 goto out;
2458 if (ret > 0) {
2459 /* there's no smaller item, so stick with the
2460 * larger one */
2461 btrfs_release_path(path);
2462 ret = btrfs_search_slot(NULL, root, &key,
2463 path, 0, 0);
2464 if (ret < 0)
2465 goto out;
2466 }
2467 }
2468
2469 stop_loop = 0;
2470 while (1) {
2471 u64 bytes;
2472
2473 l = path->nodes[0];
2474 slot = path->slots[0];
2475 if (slot >= btrfs_header_nritems(l)) {
2476 ret = btrfs_next_leaf(root, path);
2477 if (ret == 0)
2478 continue;
2479 if (ret < 0)
2480 goto out;
2481
2482 stop_loop = 1;
2483 break;
2484 }
2485 btrfs_item_key_to_cpu(l, &key, slot);
2486
2487 if (key.type == BTRFS_METADATA_ITEM_KEY)
2488 bytes = root->leafsize;
2489 else
2490 bytes = key.offset;
2491
2492 if (key.objectid + bytes <= logical)
2493 goto next;
2494
2495 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2496 key.type != BTRFS_METADATA_ITEM_KEY)
2497 goto next;
2498
2499 if (key.objectid >= logical + map->stripe_len) {
2500 /* out of this device extent */
2501 if (key.objectid >= logic_end)
2502 stop_loop = 1;
2503 break;
2504 }
2505
2506 extent = btrfs_item_ptr(l, slot,
2507 struct btrfs_extent_item);
2508 flags = btrfs_extent_flags(l, extent);
2509 generation = btrfs_extent_generation(l, extent);
2510
2511 if (key.objectid < logical &&
2512 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2513 btrfs_err(fs_info,
2514 "scrub: tree block %llu spanning "
2515 "stripes, ignored. logical=%llu",
2516 key.objectid, logical);
2517 goto next;
2518 }
2519
2520again:
2521 extent_logical = key.objectid;
2522 extent_len = bytes;
2523
2524 /*
2525 * trim extent to this stripe
2526 */
2527 if (extent_logical < logical) {
2528 extent_len -= logical - extent_logical;
2529 extent_logical = logical;
2530 }
2531 if (extent_logical + extent_len >
2532 logical + map->stripe_len) {
2533 extent_len = logical + map->stripe_len -
2534 extent_logical;
2535 }
2536
2537 extent_physical = extent_logical - logical + physical;
2538 extent_dev = scrub_dev;
2539 extent_mirror_num = mirror_num;
2540 if (is_dev_replace)
2541 scrub_remap_extent(fs_info, extent_logical,
2542 extent_len, &extent_physical,
2543 &extent_dev,
2544 &extent_mirror_num);
2545
2546 ret = btrfs_lookup_csums_range(csum_root, logical,
2547 logical + map->stripe_len - 1,
2548 &sctx->csum_list, 1);
2549 if (ret)
2550 goto out;
2551
2552 ret = scrub_extent(sctx, extent_logical, extent_len,
2553 extent_physical, extent_dev, flags,
2554 generation, extent_mirror_num,
2555 extent_logical - logical + physical);
2556 if (ret)
2557 goto out;
2558
2559 scrub_free_csums(sctx);
2560 if (extent_logical + extent_len <
2561 key.objectid + bytes) {
2562 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
2563 BTRFS_BLOCK_GROUP_RAID6)) {
2564 /*
2565 * loop until we find next data stripe
2566 * or we have finished all stripes.
2567 */
2568 do {
2569 physical += map->stripe_len;
2570 ret = get_raid56_logic_offset(
2571 physical, num,
2572 map, &logical);
2573 logical += base;
2574 } while (physical < physical_end && ret);
2575 } else {
2576 physical += map->stripe_len;
2577 logical += increment;
2578 }
2579 if (logical < key.objectid + bytes) {
2580 cond_resched();
2581 goto again;
2582 }
2583
2584 if (physical >= physical_end) {
2585 stop_loop = 1;
2586 break;
2587 }
2588 }
2589next:
2590 path->slots[0]++;
2591 }
2592 btrfs_release_path(path);
2593skip:
2594 logical += increment;
2595 physical += map->stripe_len;
2596 spin_lock(&sctx->stat_lock);
2597 if (stop_loop)
2598 sctx->stat.last_physical = map->stripes[num].physical +
2599 length;
2600 else
2601 sctx->stat.last_physical = physical;
2602 spin_unlock(&sctx->stat_lock);
2603 if (stop_loop)
2604 break;
2605 }
2606out:
2607 /* push queued extents */
2608 scrub_submit(sctx);
2609 mutex_lock(&sctx->wr_ctx.wr_lock);
2610 scrub_wr_submit(sctx);
2611 mutex_unlock(&sctx->wr_ctx.wr_lock);
2612
2613 blk_finish_plug(&plug);
2614 btrfs_free_path(path);
2615 return ret < 0 ? ret : 0;
2616}
2617
2618static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
2619 struct btrfs_device *scrub_dev,
2620 u64 chunk_tree, u64 chunk_objectid,
2621 u64 chunk_offset, u64 length,
2622 u64 dev_offset, int is_dev_replace)
2623{
2624 struct btrfs_mapping_tree *map_tree =
2625 &sctx->dev_root->fs_info->mapping_tree;
2626 struct map_lookup *map;
2627 struct extent_map *em;
2628 int i;
2629 int ret = 0;
2630
2631 read_lock(&map_tree->map_tree.lock);
2632 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2633 read_unlock(&map_tree->map_tree.lock);
2634
2635 if (!em)
2636 return -EINVAL;
2637
2638 map = (struct map_lookup *)em->bdev;
2639 if (em->start != chunk_offset)
2640 goto out;
2641
2642 if (em->len < length)
2643 goto out;
2644
2645 for (i = 0; i < map->num_stripes; ++i) {
2646 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
2647 map->stripes[i].physical == dev_offset) {
2648 ret = scrub_stripe(sctx, map, scrub_dev, i,
2649 chunk_offset, length,
2650 is_dev_replace);
2651 if (ret)
2652 goto out;
2653 }
2654 }
2655out:
2656 free_extent_map(em);
2657
2658 return ret;
2659}
2660
2661static noinline_for_stack
2662int scrub_enumerate_chunks(struct scrub_ctx *sctx,
2663 struct btrfs_device *scrub_dev, u64 start, u64 end,
2664 int is_dev_replace)
2665{
2666 struct btrfs_dev_extent *dev_extent = NULL;
2667 struct btrfs_path *path;
2668 struct btrfs_root *root = sctx->dev_root;
2669 struct btrfs_fs_info *fs_info = root->fs_info;
2670 u64 length;
2671 u64 chunk_tree;
2672 u64 chunk_objectid;
2673 u64 chunk_offset;
2674 int ret;
2675 int slot;
2676 struct extent_buffer *l;
2677 struct btrfs_key key;
2678 struct btrfs_key found_key;
2679 struct btrfs_block_group_cache *cache;
2680 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
2681
2682 path = btrfs_alloc_path();
2683 if (!path)
2684 return -ENOMEM;
2685
2686 path->reada = 2;
2687 path->search_commit_root = 1;
2688 path->skip_locking = 1;
2689
2690 key.objectid = scrub_dev->devid;
2691 key.offset = 0ull;
2692 key.type = BTRFS_DEV_EXTENT_KEY;
2693
2694 while (1) {
2695 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2696 if (ret < 0)
2697 break;
2698 if (ret > 0) {
2699 if (path->slots[0] >=
2700 btrfs_header_nritems(path->nodes[0])) {
2701 ret = btrfs_next_leaf(root, path);
2702 if (ret)
2703 break;
2704 }
2705 }
2706
2707 l = path->nodes[0];
2708 slot = path->slots[0];
2709
2710 btrfs_item_key_to_cpu(l, &found_key, slot);
2711
2712 if (found_key.objectid != scrub_dev->devid)
2713 break;
2714
2715 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
2716 break;
2717
2718 if (found_key.offset >= end)
2719 break;
2720
2721 if (found_key.offset < key.offset)
2722 break;
2723
2724 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2725 length = btrfs_dev_extent_length(l, dev_extent);
2726
2727 if (found_key.offset + length <= start) {
2728 key.offset = found_key.offset + length;
2729 btrfs_release_path(path);
2730 continue;
2731 }
2732
2733 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2734 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2735 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2736
2737 /*
2738 * get a reference on the corresponding block group to prevent
2739 * the chunk from going away while we scrub it
2740 */
2741 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2742 if (!cache) {
2743 ret = -ENOENT;
2744 break;
2745 }
2746 dev_replace->cursor_right = found_key.offset + length;
2747 dev_replace->cursor_left = found_key.offset;
2748 dev_replace->item_needs_writeback = 1;
2749 ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
2750 chunk_offset, length, found_key.offset,
2751 is_dev_replace);
2752
2753 /*
2754 * flush, submit all pending read and write bios, afterwards
2755 * wait for them.
2756 * Note that in the dev replace case, a read request causes
2757 * write requests that are submitted in the read completion
2758 * worker. Therefore in the current situation, it is required
2759 * that all write requests are flushed, so that all read and
2760 * write requests are really completed when bios_in_flight
2761 * changes to 0.
2762 */
2763 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
2764 scrub_submit(sctx);
2765 mutex_lock(&sctx->wr_ctx.wr_lock);
2766 scrub_wr_submit(sctx);
2767 mutex_unlock(&sctx->wr_ctx.wr_lock);
2768
2769 wait_event(sctx->list_wait,
2770 atomic_read(&sctx->bios_in_flight) == 0);
2771 atomic_inc(&fs_info->scrubs_paused);
2772 wake_up(&fs_info->scrub_pause_wait);
2773
2774 /*
2775 * must be called before we decrease @scrub_paused.
2776 * make sure we don't block transaction commit while
2777 * we are waiting pending workers finished.
2778 */
2779 wait_event(sctx->list_wait,
2780 atomic_read(&sctx->workers_pending) == 0);
2781 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
2782
2783 mutex_lock(&fs_info->scrub_lock);
2784 __scrub_blocked_if_needed(fs_info);
2785 atomic_dec(&fs_info->scrubs_paused);
2786 mutex_unlock(&fs_info->scrub_lock);
2787 wake_up(&fs_info->scrub_pause_wait);
2788
2789 btrfs_put_block_group(cache);
2790 if (ret)
2791 break;
2792 if (is_dev_replace &&
2793 atomic64_read(&dev_replace->num_write_errors) > 0) {
2794 ret = -EIO;
2795 break;
2796 }
2797 if (sctx->stat.malloc_errors > 0) {
2798 ret = -ENOMEM;
2799 break;
2800 }
2801
2802 dev_replace->cursor_left = dev_replace->cursor_right;
2803 dev_replace->item_needs_writeback = 1;
2804
2805 key.offset = found_key.offset + length;
2806 btrfs_release_path(path);
2807 }
2808
2809 btrfs_free_path(path);
2810
2811 /*
2812 * ret can still be 1 from search_slot or next_leaf,
2813 * that's not an error
2814 */
2815 return ret < 0 ? ret : 0;
2816}
2817
2818static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
2819 struct btrfs_device *scrub_dev)
2820{
2821 int i;
2822 u64 bytenr;
2823 u64 gen;
2824 int ret;
2825 struct btrfs_root *root = sctx->dev_root;
2826
2827 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
2828 return -EIO;
2829
2830 gen = root->fs_info->last_trans_committed;
2831
2832 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2833 bytenr = btrfs_sb_offset(i);
2834 if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
2835 break;
2836
2837 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
2838 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
2839 NULL, 1, bytenr);
2840 if (ret)
2841 return ret;
2842 }
2843 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
2844
2845 return 0;
2846}
2847
2848/*
2849 * get a reference count on fs_info->scrub_workers. start worker if necessary
2850 */
2851static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
2852 int is_dev_replace)
2853{
2854 int ret = 0;
2855 int flags = WQ_FREEZABLE | WQ_UNBOUND;
2856 int max_active = fs_info->thread_pool_size;
2857
2858 if (fs_info->scrub_workers_refcnt == 0) {
2859 if (is_dev_replace)
2860 fs_info->scrub_workers =
2861 btrfs_alloc_workqueue("btrfs-scrub", flags,
2862 1, 4);
2863 else
2864 fs_info->scrub_workers =
2865 btrfs_alloc_workqueue("btrfs-scrub", flags,
2866 max_active, 4);
2867 if (!fs_info->scrub_workers) {
2868 ret = -ENOMEM;
2869 goto out;
2870 }
2871 fs_info->scrub_wr_completion_workers =
2872 btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
2873 max_active, 2);
2874 if (!fs_info->scrub_wr_completion_workers) {
2875 ret = -ENOMEM;
2876 goto out;
2877 }
2878 fs_info->scrub_nocow_workers =
2879 btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
2880 if (!fs_info->scrub_nocow_workers) {
2881 ret = -ENOMEM;
2882 goto out;
2883 }
2884 }
2885 ++fs_info->scrub_workers_refcnt;
2886out:
2887 return ret;
2888}
2889
2890static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
2891{
2892 if (--fs_info->scrub_workers_refcnt == 0) {
2893 btrfs_destroy_workqueue(fs_info->scrub_workers);
2894 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
2895 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
2896 }
2897 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2898}
2899
2900int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
2901 u64 end, struct btrfs_scrub_progress *progress,
2902 int readonly, int is_dev_replace)
2903{
2904 struct scrub_ctx *sctx;
2905 int ret;
2906 struct btrfs_device *dev;
2907
2908 if (btrfs_fs_closing(fs_info))
2909 return -EINVAL;
2910
2911 /*
2912 * check some assumptions
2913 */
2914 if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
2915 btrfs_err(fs_info,
2916 "scrub: size assumption nodesize == leafsize (%d == %d) fails",
2917 fs_info->chunk_root->nodesize,
2918 fs_info->chunk_root->leafsize);
2919 return -EINVAL;
2920 }
2921
2922 if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
2923 /*
2924 * in this case scrub is unable to calculate the checksum
2925 * the way scrub is implemented. Do not handle this
2926 * situation at all because it won't ever happen.
2927 */
2928 btrfs_err(fs_info,
2929 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
2930 fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
2931 return -EINVAL;
2932 }
2933
2934 if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
2935 /* not supported for data w/o checksums */
2936 btrfs_err(fs_info,
2937 "scrub: size assumption sectorsize != PAGE_SIZE "
2938 "(%d != %lu) fails",
2939 fs_info->chunk_root->sectorsize, PAGE_SIZE);
2940 return -EINVAL;
2941 }
2942
2943 if (fs_info->chunk_root->nodesize >
2944 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
2945 fs_info->chunk_root->sectorsize >
2946 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
2947 /*
2948 * would exhaust the array bounds of pagev member in
2949 * struct scrub_block
2950 */
2951 btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
2952 "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
2953 fs_info->chunk_root->nodesize,
2954 SCRUB_MAX_PAGES_PER_BLOCK,
2955 fs_info->chunk_root->sectorsize,
2956 SCRUB_MAX_PAGES_PER_BLOCK);
2957 return -EINVAL;
2958 }
2959
2960
2961 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2962 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
2963 if (!dev || (dev->missing && !is_dev_replace)) {
2964 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2965 return -ENODEV;
2966 }
2967
2968 mutex_lock(&fs_info->scrub_lock);
2969 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
2970 mutex_unlock(&fs_info->scrub_lock);
2971 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2972 return -EIO;
2973 }
2974
2975 btrfs_dev_replace_lock(&fs_info->dev_replace);
2976 if (dev->scrub_device ||
2977 (!is_dev_replace &&
2978 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
2979 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2980 mutex_unlock(&fs_info->scrub_lock);
2981 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2982 return -EINPROGRESS;
2983 }
2984 btrfs_dev_replace_unlock(&fs_info->dev_replace);
2985
2986 ret = scrub_workers_get(fs_info, is_dev_replace);
2987 if (ret) {
2988 mutex_unlock(&fs_info->scrub_lock);
2989 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2990 return ret;
2991 }
2992
2993 sctx = scrub_setup_ctx(dev, is_dev_replace);
2994 if (IS_ERR(sctx)) {
2995 mutex_unlock(&fs_info->scrub_lock);
2996 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2997 scrub_workers_put(fs_info);
2998 return PTR_ERR(sctx);
2999 }
3000 sctx->readonly = readonly;
3001 dev->scrub_device = sctx;
3002 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3003
3004 /*
3005 * checking @scrub_pause_req here, we can avoid
3006 * race between committing transaction and scrubbing.
3007 */
3008 __scrub_blocked_if_needed(fs_info);
3009 atomic_inc(&fs_info->scrubs_running);
3010 mutex_unlock(&fs_info->scrub_lock);
3011
3012 if (!is_dev_replace) {
3013 /*
3014 * by holding device list mutex, we can
3015 * kick off writing super in log tree sync.
3016 */
3017 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3018 ret = scrub_supers(sctx, dev);
3019 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3020 }
3021
3022 if (!ret)
3023 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3024 is_dev_replace);
3025
3026 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3027 atomic_dec(&fs_info->scrubs_running);
3028 wake_up(&fs_info->scrub_pause_wait);
3029
3030 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3031
3032 if (progress)
3033 memcpy(progress, &sctx->stat, sizeof(*progress));
3034
3035 mutex_lock(&fs_info->scrub_lock);
3036 dev->scrub_device = NULL;
3037 scrub_workers_put(fs_info);
3038 mutex_unlock(&fs_info->scrub_lock);
3039
3040 scrub_free_ctx(sctx);
3041
3042 return ret;
3043}
3044
3045void btrfs_scrub_pause(struct btrfs_root *root)
3046{
3047 struct btrfs_fs_info *fs_info = root->fs_info;
3048
3049 mutex_lock(&fs_info->scrub_lock);
3050 atomic_inc(&fs_info->scrub_pause_req);
3051 while (atomic_read(&fs_info->scrubs_paused) !=
3052 atomic_read(&fs_info->scrubs_running)) {
3053 mutex_unlock(&fs_info->scrub_lock);
3054 wait_event(fs_info->scrub_pause_wait,
3055 atomic_read(&fs_info->scrubs_paused) ==
3056 atomic_read(&fs_info->scrubs_running));
3057 mutex_lock(&fs_info->scrub_lock);
3058 }
3059 mutex_unlock(&fs_info->scrub_lock);
3060}
3061
3062void btrfs_scrub_continue(struct btrfs_root *root)
3063{
3064 struct btrfs_fs_info *fs_info = root->fs_info;
3065
3066 atomic_dec(&fs_info->scrub_pause_req);
3067 wake_up(&fs_info->scrub_pause_wait);
3068}
3069
3070int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3071{
3072 mutex_lock(&fs_info->scrub_lock);
3073 if (!atomic_read(&fs_info->scrubs_running)) {
3074 mutex_unlock(&fs_info->scrub_lock);
3075 return -ENOTCONN;
3076 }
3077
3078 atomic_inc(&fs_info->scrub_cancel_req);
3079 while (atomic_read(&fs_info->scrubs_running)) {
3080 mutex_unlock(&fs_info->scrub_lock);
3081 wait_event(fs_info->scrub_pause_wait,
3082 atomic_read(&fs_info->scrubs_running) == 0);
3083 mutex_lock(&fs_info->scrub_lock);
3084 }
3085 atomic_dec(&fs_info->scrub_cancel_req);
3086 mutex_unlock(&fs_info->scrub_lock);
3087
3088 return 0;
3089}
3090
3091int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
3092 struct btrfs_device *dev)
3093{
3094 struct scrub_ctx *sctx;
3095
3096 mutex_lock(&fs_info->scrub_lock);
3097 sctx = dev->scrub_device;
3098 if (!sctx) {
3099 mutex_unlock(&fs_info->scrub_lock);
3100 return -ENOTCONN;
3101 }
3102 atomic_inc(&sctx->cancel_req);
3103 while (dev->scrub_device) {
3104 mutex_unlock(&fs_info->scrub_lock);
3105 wait_event(fs_info->scrub_pause_wait,
3106 dev->scrub_device == NULL);
3107 mutex_lock(&fs_info->scrub_lock);
3108 }
3109 mutex_unlock(&fs_info->scrub_lock);
3110
3111 return 0;
3112}
3113
3114int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
3115 struct btrfs_scrub_progress *progress)
3116{
3117 struct btrfs_device *dev;
3118 struct scrub_ctx *sctx = NULL;
3119
3120 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3121 dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
3122 if (dev)
3123 sctx = dev->scrub_device;
3124 if (sctx)
3125 memcpy(progress, &sctx->stat, sizeof(*progress));
3126 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3127
3128 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
3129}
3130
3131static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
3132 u64 extent_logical, u64 extent_len,
3133 u64 *extent_physical,
3134 struct btrfs_device **extent_dev,
3135 int *extent_mirror_num)
3136{
3137 u64 mapped_length;
3138 struct btrfs_bio *bbio = NULL;
3139 int ret;
3140
3141 mapped_length = extent_len;
3142 ret = btrfs_map_block(fs_info, READ, extent_logical,
3143 &mapped_length, &bbio, 0);
3144 if (ret || !bbio || mapped_length < extent_len ||
3145 !bbio->stripes[0].dev->bdev) {
3146 kfree(bbio);
3147 return;
3148 }
3149
3150 *extent_physical = bbio->stripes[0].physical;
3151 *extent_mirror_num = bbio->mirror_num;
3152 *extent_dev = bbio->stripes[0].dev;
3153 kfree(bbio);
3154}
3155
3156static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
3157 struct scrub_wr_ctx *wr_ctx,
3158 struct btrfs_fs_info *fs_info,
3159 struct btrfs_device *dev,
3160 int is_dev_replace)
3161{
3162 WARN_ON(wr_ctx->wr_curr_bio != NULL);
3163
3164 mutex_init(&wr_ctx->wr_lock);
3165 wr_ctx->wr_curr_bio = NULL;
3166 if (!is_dev_replace)
3167 return 0;
3168
3169 WARN_ON(!dev->bdev);
3170 wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
3171 bio_get_nr_vecs(dev->bdev));
3172 wr_ctx->tgtdev = dev;
3173 atomic_set(&wr_ctx->flush_all_writes, 0);
3174 return 0;
3175}
3176
3177static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
3178{
3179 mutex_lock(&wr_ctx->wr_lock);
3180 kfree(wr_ctx->wr_curr_bio);
3181 wr_ctx->wr_curr_bio = NULL;
3182 mutex_unlock(&wr_ctx->wr_lock);
3183}
3184
3185static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
3186 int mirror_num, u64 physical_for_dev_replace)
3187{
3188 struct scrub_copy_nocow_ctx *nocow_ctx;
3189 struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
3190
3191 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
3192 if (!nocow_ctx) {
3193 spin_lock(&sctx->stat_lock);
3194 sctx->stat.malloc_errors++;
3195 spin_unlock(&sctx->stat_lock);
3196 return -ENOMEM;
3197 }
3198
3199 scrub_pending_trans_workers_inc(sctx);
3200
3201 nocow_ctx->sctx = sctx;
3202 nocow_ctx->logical = logical;
3203 nocow_ctx->len = len;
3204 nocow_ctx->mirror_num = mirror_num;
3205 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
3206 btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL);
3207 INIT_LIST_HEAD(&nocow_ctx->inodes);
3208 btrfs_queue_work(fs_info->scrub_nocow_workers,
3209 &nocow_ctx->work);
3210
3211 return 0;
3212}
3213
3214static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
3215{
3216 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
3217 struct scrub_nocow_inode *nocow_inode;
3218
3219 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
3220 if (!nocow_inode)
3221 return -ENOMEM;
3222 nocow_inode->inum = inum;
3223 nocow_inode->offset = offset;
3224 nocow_inode->root = root;
3225 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
3226 return 0;
3227}
3228
3229#define COPY_COMPLETE 1
3230
3231static void copy_nocow_pages_worker(struct btrfs_work *work)
3232{
3233 struct scrub_copy_nocow_ctx *nocow_ctx =
3234 container_of(work, struct scrub_copy_nocow_ctx, work);
3235 struct scrub_ctx *sctx = nocow_ctx->sctx;
3236 u64 logical = nocow_ctx->logical;
3237 u64 len = nocow_ctx->len;
3238 int mirror_num = nocow_ctx->mirror_num;
3239 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3240 int ret;
3241 struct btrfs_trans_handle *trans = NULL;
3242 struct btrfs_fs_info *fs_info;
3243 struct btrfs_path *path;
3244 struct btrfs_root *root;
3245 int not_written = 0;
3246
3247 fs_info = sctx->dev_root->fs_info;
3248 root = fs_info->extent_root;
3249
3250 path = btrfs_alloc_path();
3251 if (!path) {
3252 spin_lock(&sctx->stat_lock);
3253 sctx->stat.malloc_errors++;
3254 spin_unlock(&sctx->stat_lock);
3255 not_written = 1;
3256 goto out;
3257 }
3258
3259 trans = btrfs_join_transaction(root);
3260 if (IS_ERR(trans)) {
3261 not_written = 1;
3262 goto out;
3263 }
3264
3265 ret = iterate_inodes_from_logical(logical, fs_info, path,
3266 record_inode_for_nocow, nocow_ctx);
3267 if (ret != 0 && ret != -ENOENT) {
3268 btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
3269 "phys %llu, len %llu, mir %u, ret %d",
3270 logical, physical_for_dev_replace, len, mirror_num,
3271 ret);
3272 not_written = 1;
3273 goto out;
3274 }
3275
3276 btrfs_end_transaction(trans, root);
3277 trans = NULL;
3278 while (!list_empty(&nocow_ctx->inodes)) {
3279 struct scrub_nocow_inode *entry;
3280 entry = list_first_entry(&nocow_ctx->inodes,
3281 struct scrub_nocow_inode,
3282 list);
3283 list_del_init(&entry->list);
3284 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
3285 entry->root, nocow_ctx);
3286 kfree(entry);
3287 if (ret == COPY_COMPLETE) {
3288 ret = 0;
3289 break;
3290 } else if (ret) {
3291 break;
3292 }
3293 }
3294out:
3295 while (!list_empty(&nocow_ctx->inodes)) {
3296 struct scrub_nocow_inode *entry;
3297 entry = list_first_entry(&nocow_ctx->inodes,
3298 struct scrub_nocow_inode,
3299 list);
3300 list_del_init(&entry->list);
3301 kfree(entry);
3302 }
3303 if (trans && !IS_ERR(trans))
3304 btrfs_end_transaction(trans, root);
3305 if (not_written)
3306 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
3307 num_uncorrectable_read_errors);
3308
3309 btrfs_free_path(path);
3310 kfree(nocow_ctx);
3311
3312 scrub_pending_trans_workers_dec(sctx);
3313}
3314
3315static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
3316 struct scrub_copy_nocow_ctx *nocow_ctx)
3317{
3318 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
3319 struct btrfs_key key;
3320 struct inode *inode;
3321 struct page *page;
3322 struct btrfs_root *local_root;
3323 struct btrfs_ordered_extent *ordered;
3324 struct extent_map *em;
3325 struct extent_state *cached_state = NULL;
3326 struct extent_io_tree *io_tree;
3327 u64 physical_for_dev_replace;
3328 u64 len = nocow_ctx->len;
3329 u64 lockstart = offset, lockend = offset + len - 1;
3330 unsigned long index;
3331 int srcu_index;
3332 int ret = 0;
3333 int err = 0;
3334
3335 key.objectid = root;
3336 key.type = BTRFS_ROOT_ITEM_KEY;
3337 key.offset = (u64)-1;
3338
3339 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
3340
3341 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
3342 if (IS_ERR(local_root)) {
3343 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3344 return PTR_ERR(local_root);
3345 }
3346
3347 key.type = BTRFS_INODE_ITEM_KEY;
3348 key.objectid = inum;
3349 key.offset = 0;
3350 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
3351 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
3352 if (IS_ERR(inode))
3353 return PTR_ERR(inode);
3354
3355 /* Avoid truncate/dio/punch hole.. */
3356 mutex_lock(&inode->i_mutex);
3357 inode_dio_wait(inode);
3358
3359 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
3360 io_tree = &BTRFS_I(inode)->io_tree;
3361
3362 lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
3363 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
3364 if (ordered) {
3365 btrfs_put_ordered_extent(ordered);
3366 goto out_unlock;
3367 }
3368
3369 em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
3370 if (IS_ERR(em)) {
3371 ret = PTR_ERR(em);
3372 goto out_unlock;
3373 }
3374
3375 /*
3376 * This extent does not actually cover the logical extent anymore,
3377 * move on to the next inode.
3378 */
3379 if (em->block_start > nocow_ctx->logical ||
3380 em->block_start + em->block_len < nocow_ctx->logical + len) {
3381 free_extent_map(em);
3382 goto out_unlock;
3383 }
3384 free_extent_map(em);
3385
3386 while (len >= PAGE_CACHE_SIZE) {
3387 index = offset >> PAGE_CACHE_SHIFT;
3388again:
3389 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3390 if (!page) {
3391 btrfs_err(fs_info, "find_or_create_page() failed");
3392 ret = -ENOMEM;
3393 goto out;
3394 }
3395
3396 if (PageUptodate(page)) {
3397 if (PageDirty(page))
3398 goto next_page;
3399 } else {
3400 ClearPageError(page);
3401 err = extent_read_full_page_nolock(io_tree, page,
3402 btrfs_get_extent,
3403 nocow_ctx->mirror_num);
3404 if (err) {
3405 ret = err;
3406 goto next_page;
3407 }
3408
3409 lock_page(page);
3410 /*
3411 * If the page has been remove from the page cache,
3412 * the data on it is meaningless, because it may be
3413 * old one, the new data may be written into the new
3414 * page in the page cache.
3415 */
3416 if (page->mapping != inode->i_mapping) {
3417 unlock_page(page);
3418 page_cache_release(page);
3419 goto again;
3420 }
3421 if (!PageUptodate(page)) {
3422 ret = -EIO;
3423 goto next_page;
3424 }
3425 }
3426 err = write_page_nocow(nocow_ctx->sctx,
3427 physical_for_dev_replace, page);
3428 if (err)
3429 ret = err;
3430next_page:
3431 unlock_page(page);
3432 page_cache_release(page);
3433
3434 if (ret)
3435 break;
3436
3437 offset += PAGE_CACHE_SIZE;
3438 physical_for_dev_replace += PAGE_CACHE_SIZE;
3439 len -= PAGE_CACHE_SIZE;
3440 }
3441 ret = COPY_COMPLETE;
3442out_unlock:
3443 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
3444 GFP_NOFS);
3445out:
3446 mutex_unlock(&inode->i_mutex);
3447 iput(inode);
3448 return ret;
3449}
3450
3451static int write_page_nocow(struct scrub_ctx *sctx,
3452 u64 physical_for_dev_replace, struct page *page)
3453{
3454 struct bio *bio;
3455 struct btrfs_device *dev;
3456 int ret;
3457
3458 dev = sctx->wr_ctx.tgtdev;
3459 if (!dev)
3460 return -EIO;
3461 if (!dev->bdev) {
3462 printk_ratelimited(KERN_WARNING
3463 "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
3464 return -EIO;
3465 }
3466 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
3467 if (!bio) {
3468 spin_lock(&sctx->stat_lock);
3469 sctx->stat.malloc_errors++;
3470 spin_unlock(&sctx->stat_lock);
3471 return -ENOMEM;
3472 }
3473 bio->bi_iter.bi_size = 0;
3474 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
3475 bio->bi_bdev = dev->bdev;
3476 ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
3477 if (ret != PAGE_CACHE_SIZE) {
3478leave_with_eio:
3479 bio_put(bio);
3480 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
3481 return -EIO;
3482 }
3483
3484 if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
3485 goto leave_with_eio;
3486
3487 bio_put(bio);
3488 return 0;
3489}