2 * Copyright (C) 2011 STRATO. All rights reserved.
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.
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.
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.
19 #include <linux/blkdev.h>
20 #include <linux/ratelimit.h>
24 #include "ordered-data.h"
25 #include "transaction.h"
27 #include "extent_io.h"
28 #include "check-integrity.h"
29 #include "rcu-string.h"
32 * This is only the first step towards a full-features scrub. It reads all
33 * extent and super block and verifies the checksums. In case a bad checksum
34 * is found or the extent cannot be read, good data will be written back if
37 * Future enhancements:
38 * - In case an unrepairable extent is encountered, track which files are
39 * affected and report them
40 * - track and record media errors, throw out bad devices
41 * - add a mode to also read unallocated space
47 #define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
48 #define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
49 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
52 struct scrub_block *sblock;
54 struct btrfs_device *dev;
55 u64 flags; /* extent flags */
60 unsigned int mirror_num:8;
61 unsigned int have_csum:1;
62 unsigned int io_error:1;
64 u8 csum[BTRFS_CSUM_SIZE];
69 struct scrub_dev *sdev;
74 struct scrub_page *pagev[SCRUB_PAGES_PER_BIO];
77 struct btrfs_work work;
81 struct scrub_page pagev[SCRUB_MAX_PAGES_PER_BLOCK];
83 atomic_t outstanding_pages;
84 atomic_t ref_count; /* free mem on transition to zero */
85 struct scrub_dev *sdev;
87 unsigned int header_error:1;
88 unsigned int checksum_error:1;
89 unsigned int no_io_error_seen:1;
90 unsigned int generation_error:1; /* also sets header_error */
95 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
96 struct btrfs_device *dev;
101 spinlock_t list_lock;
102 wait_queue_head_t list_wait;
104 struct list_head csum_list;
107 int pages_per_bio; /* <= SCRUB_PAGES_PER_BIO */
114 struct btrfs_scrub_progress stat;
115 spinlock_t stat_lock;
118 struct scrub_fixup_nodatasum {
119 struct scrub_dev *sdev;
121 struct btrfs_root *root;
122 struct btrfs_work work;
126 struct scrub_warning {
127 struct btrfs_path *path;
128 u64 extent_item_size;
134 struct btrfs_device *dev;
140 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
141 static int scrub_setup_recheck_block(struct scrub_dev *sdev,
142 struct btrfs_mapping_tree *map_tree,
143 u64 length, u64 logical,
144 struct scrub_block *sblock);
145 static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
146 struct scrub_block *sblock, int is_metadata,
147 int have_csum, u8 *csum, u64 generation,
149 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
150 struct scrub_block *sblock,
151 int is_metadata, int have_csum,
152 const u8 *csum, u64 generation,
154 static void scrub_complete_bio_end_io(struct bio *bio, int err);
155 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
156 struct scrub_block *sblock_good,
158 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
159 struct scrub_block *sblock_good,
160 int page_num, int force_write);
161 static int scrub_checksum_data(struct scrub_block *sblock);
162 static int scrub_checksum_tree_block(struct scrub_block *sblock);
163 static int scrub_checksum_super(struct scrub_block *sblock);
164 static void scrub_block_get(struct scrub_block *sblock);
165 static void scrub_block_put(struct scrub_block *sblock);
166 static int scrub_add_page_to_bio(struct scrub_dev *sdev,
167 struct scrub_page *spage);
168 static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len,
169 u64 physical, u64 flags, u64 gen, int mirror_num,
170 u8 *csum, int force);
171 static void scrub_bio_end_io(struct bio *bio, int err);
172 static void scrub_bio_end_io_worker(struct btrfs_work *work);
173 static void scrub_block_complete(struct scrub_block *sblock);
176 static void scrub_free_csums(struct scrub_dev *sdev)
178 while (!list_empty(&sdev->csum_list)) {
179 struct btrfs_ordered_sum *sum;
180 sum = list_first_entry(&sdev->csum_list,
181 struct btrfs_ordered_sum, list);
182 list_del(&sum->list);
187 static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
194 /* this can happen when scrub is cancelled */
195 if (sdev->curr != -1) {
196 struct scrub_bio *sbio = sdev->bios[sdev->curr];
198 for (i = 0; i < sbio->page_count; i++) {
199 BUG_ON(!sbio->pagev[i]);
200 BUG_ON(!sbio->pagev[i]->page);
201 scrub_block_put(sbio->pagev[i]->sblock);
206 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
207 struct scrub_bio *sbio = sdev->bios[i];
214 scrub_free_csums(sdev);
218 static noinline_for_stack
219 struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
221 struct scrub_dev *sdev;
223 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
226 pages_per_bio = min_t(int, SCRUB_PAGES_PER_BIO,
227 bio_get_nr_vecs(dev->bdev));
228 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
232 sdev->pages_per_bio = pages_per_bio;
234 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
235 struct scrub_bio *sbio;
237 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
240 sdev->bios[i] = sbio;
244 sbio->page_count = 0;
245 sbio->work.func = scrub_bio_end_io_worker;
247 if (i != SCRUB_BIOS_PER_DEV-1)
248 sdev->bios[i]->next_free = i + 1;
250 sdev->bios[i]->next_free = -1;
252 sdev->first_free = 0;
253 sdev->nodesize = dev->dev_root->nodesize;
254 sdev->leafsize = dev->dev_root->leafsize;
255 sdev->sectorsize = dev->dev_root->sectorsize;
256 atomic_set(&sdev->in_flight, 0);
257 atomic_set(&sdev->fixup_cnt, 0);
258 atomic_set(&sdev->cancel_req, 0);
259 sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
260 INIT_LIST_HEAD(&sdev->csum_list);
262 spin_lock_init(&sdev->list_lock);
263 spin_lock_init(&sdev->stat_lock);
264 init_waitqueue_head(&sdev->list_wait);
268 scrub_free_dev(sdev);
269 return ERR_PTR(-ENOMEM);
272 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
278 struct extent_buffer *eb;
279 struct btrfs_inode_item *inode_item;
280 struct scrub_warning *swarn = ctx;
281 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
282 struct inode_fs_paths *ipath = NULL;
283 struct btrfs_root *local_root;
284 struct btrfs_key root_key;
286 root_key.objectid = root;
287 root_key.type = BTRFS_ROOT_ITEM_KEY;
288 root_key.offset = (u64)-1;
289 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
290 if (IS_ERR(local_root)) {
291 ret = PTR_ERR(local_root);
295 ret = inode_item_info(inum, 0, local_root, swarn->path);
297 btrfs_release_path(swarn->path);
301 eb = swarn->path->nodes[0];
302 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
303 struct btrfs_inode_item);
304 isize = btrfs_inode_size(eb, inode_item);
305 nlink = btrfs_inode_nlink(eb, inode_item);
306 btrfs_release_path(swarn->path);
308 ipath = init_ipath(4096, local_root, swarn->path);
310 ret = PTR_ERR(ipath);
314 ret = paths_from_inode(inum, ipath);
320 * we deliberately ignore the bit ipath might have been too small to
321 * hold all of the paths here
323 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
324 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
325 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
326 "length %llu, links %u (path: %s)\n", swarn->errstr,
327 swarn->logical, rcu_str_deref(swarn->dev->name),
328 (unsigned long long)swarn->sector, root, inum, offset,
329 min(isize - offset, (u64)PAGE_SIZE), nlink,
330 (char *)(unsigned long)ipath->fspath->val[i]);
336 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
337 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
338 "resolving failed with ret=%d\n", swarn->errstr,
339 swarn->logical, rcu_str_deref(swarn->dev->name),
340 (unsigned long long)swarn->sector, root, inum, offset, ret);
346 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
348 struct btrfs_device *dev = sblock->sdev->dev;
349 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
350 struct btrfs_path *path;
351 struct btrfs_key found_key;
352 struct extent_buffer *eb;
353 struct btrfs_extent_item *ei;
354 struct scrub_warning swarn;
359 unsigned long ptr = 0;
360 const int bufsize = 4096;
363 path = btrfs_alloc_path();
365 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
366 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
367 BUG_ON(sblock->page_count < 1);
368 swarn.sector = (sblock->pagev[0].physical) >> 9;
369 swarn.logical = sblock->pagev[0].logical;
370 swarn.errstr = errstr;
372 swarn.msg_bufsize = bufsize;
373 swarn.scratch_bufsize = bufsize;
375 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
378 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
382 extent_item_pos = swarn.logical - found_key.objectid;
383 swarn.extent_item_size = found_key.offset;
386 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
387 item_size = btrfs_item_size_nr(eb, path->slots[0]);
388 btrfs_release_path(path);
390 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
392 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
393 &ref_root, &ref_level);
394 printk_in_rcu(KERN_WARNING
395 "btrfs: %s at logical %llu on dev %s, "
396 "sector %llu: metadata %s (level %d) in tree "
397 "%llu\n", errstr, swarn.logical,
398 rcu_str_deref(dev->name),
399 (unsigned long long)swarn.sector,
400 ref_level ? "node" : "leaf",
401 ret < 0 ? -1 : ref_level,
402 ret < 0 ? -1 : ref_root);
406 iterate_extent_inodes(fs_info, found_key.objectid,
408 scrub_print_warning_inode, &swarn);
412 btrfs_free_path(path);
413 kfree(swarn.scratch_buf);
414 kfree(swarn.msg_buf);
417 static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
419 struct page *page = NULL;
421 struct scrub_fixup_nodatasum *fixup = ctx;
424 struct btrfs_key key;
425 struct inode *inode = NULL;
426 u64 end = offset + PAGE_SIZE - 1;
427 struct btrfs_root *local_root;
430 key.type = BTRFS_ROOT_ITEM_KEY;
431 key.offset = (u64)-1;
432 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
433 if (IS_ERR(local_root))
434 return PTR_ERR(local_root);
436 key.type = BTRFS_INODE_ITEM_KEY;
439 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
441 return PTR_ERR(inode);
443 index = offset >> PAGE_CACHE_SHIFT;
445 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
451 if (PageUptodate(page)) {
452 struct btrfs_mapping_tree *map_tree;
453 if (PageDirty(page)) {
455 * we need to write the data to the defect sector. the
456 * data that was in that sector is not in memory,
457 * because the page was modified. we must not write the
458 * modified page to that sector.
460 * TODO: what could be done here: wait for the delalloc
461 * runner to write out that page (might involve
462 * COW) and see whether the sector is still
463 * referenced afterwards.
465 * For the meantime, we'll treat this error
466 * incorrectable, although there is a chance that a
467 * later scrub will find the bad sector again and that
468 * there's no dirty page in memory, then.
473 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
474 ret = repair_io_failure(map_tree, offset, PAGE_SIZE,
475 fixup->logical, page,
481 * we need to get good data first. the general readpage path
482 * will call repair_io_failure for us, we just have to make
483 * sure we read the bad mirror.
485 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
486 EXTENT_DAMAGED, GFP_NOFS);
488 /* set_extent_bits should give proper error */
495 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
498 wait_on_page_locked(page);
500 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
501 end, EXTENT_DAMAGED, 0, NULL);
503 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
504 EXTENT_DAMAGED, GFP_NOFS);
516 if (ret == 0 && corrected) {
518 * we only need to call readpage for one of the inodes belonging
519 * to this extent. so make iterate_extent_inodes stop
527 static void scrub_fixup_nodatasum(struct btrfs_work *work)
530 struct scrub_fixup_nodatasum *fixup;
531 struct scrub_dev *sdev;
532 struct btrfs_trans_handle *trans = NULL;
533 struct btrfs_fs_info *fs_info;
534 struct btrfs_path *path;
535 int uncorrectable = 0;
537 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
539 fs_info = fixup->root->fs_info;
541 path = btrfs_alloc_path();
543 spin_lock(&sdev->stat_lock);
544 ++sdev->stat.malloc_errors;
545 spin_unlock(&sdev->stat_lock);
550 trans = btrfs_join_transaction(fixup->root);
557 * the idea is to trigger a regular read through the standard path. we
558 * read a page from the (failed) logical address by specifying the
559 * corresponding copynum of the failed sector. thus, that readpage is
561 * that is the point where on-the-fly error correction will kick in
562 * (once it's finished) and rewrite the failed sector if a good copy
565 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
566 path, scrub_fixup_readpage,
574 spin_lock(&sdev->stat_lock);
575 ++sdev->stat.corrected_errors;
576 spin_unlock(&sdev->stat_lock);
579 if (trans && !IS_ERR(trans))
580 btrfs_end_transaction(trans, fixup->root);
582 spin_lock(&sdev->stat_lock);
583 ++sdev->stat.uncorrectable_errors;
584 spin_unlock(&sdev->stat_lock);
586 printk_ratelimited_in_rcu(KERN_ERR
587 "btrfs: unable to fixup (nodatasum) error at logical %llu on dev %s\n",
588 (unsigned long long)fixup->logical,
589 rcu_str_deref(sdev->dev->name));
592 btrfs_free_path(path);
595 /* see caller why we're pretending to be paused in the scrub counters */
596 mutex_lock(&fs_info->scrub_lock);
597 atomic_dec(&fs_info->scrubs_running);
598 atomic_dec(&fs_info->scrubs_paused);
599 mutex_unlock(&fs_info->scrub_lock);
600 atomic_dec(&sdev->fixup_cnt);
601 wake_up(&fs_info->scrub_pause_wait);
602 wake_up(&sdev->list_wait);
606 * scrub_handle_errored_block gets called when either verification of the
607 * pages failed or the bio failed to read, e.g. with EIO. In the latter
608 * case, this function handles all pages in the bio, even though only one
610 * The goal of this function is to repair the errored block by using the
611 * contents of one of the mirrors.
613 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
615 struct scrub_dev *sdev = sblock_to_check->sdev;
616 struct btrfs_fs_info *fs_info;
620 unsigned int failed_mirror_index;
621 unsigned int is_metadata;
622 unsigned int have_csum;
624 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
625 struct scrub_block *sblock_bad;
630 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
631 DEFAULT_RATELIMIT_BURST);
633 BUG_ON(sblock_to_check->page_count < 1);
634 fs_info = sdev->dev->dev_root->fs_info;
635 length = sblock_to_check->page_count * PAGE_SIZE;
636 logical = sblock_to_check->pagev[0].logical;
637 generation = sblock_to_check->pagev[0].generation;
638 BUG_ON(sblock_to_check->pagev[0].mirror_num < 1);
639 failed_mirror_index = sblock_to_check->pagev[0].mirror_num - 1;
640 is_metadata = !(sblock_to_check->pagev[0].flags &
641 BTRFS_EXTENT_FLAG_DATA);
642 have_csum = sblock_to_check->pagev[0].have_csum;
643 csum = sblock_to_check->pagev[0].csum;
646 * read all mirrors one after the other. This includes to
647 * re-read the extent or metadata block that failed (that was
648 * the cause that this fixup code is called) another time,
649 * page by page this time in order to know which pages
650 * caused I/O errors and which ones are good (for all mirrors).
651 * It is the goal to handle the situation when more than one
652 * mirror contains I/O errors, but the errors do not
653 * overlap, i.e. the data can be repaired by selecting the
654 * pages from those mirrors without I/O error on the
655 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
656 * would be that mirror #1 has an I/O error on the first page,
657 * the second page is good, and mirror #2 has an I/O error on
658 * the second page, but the first page is good.
659 * Then the first page of the first mirror can be repaired by
660 * taking the first page of the second mirror, and the
661 * second page of the second mirror can be repaired by
662 * copying the contents of the 2nd page of the 1st mirror.
663 * One more note: if the pages of one mirror contain I/O
664 * errors, the checksum cannot be verified. In order to get
665 * the best data for repairing, the first attempt is to find
666 * a mirror without I/O errors and with a validated checksum.
667 * Only if this is not possible, the pages are picked from
668 * mirrors with I/O errors without considering the checksum.
669 * If the latter is the case, at the end, the checksum of the
670 * repaired area is verified in order to correctly maintain
674 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
675 sizeof(*sblocks_for_recheck),
677 if (!sblocks_for_recheck) {
678 spin_lock(&sdev->stat_lock);
679 sdev->stat.malloc_errors++;
680 sdev->stat.read_errors++;
681 sdev->stat.uncorrectable_errors++;
682 spin_unlock(&sdev->stat_lock);
683 btrfs_dev_stat_inc_and_print(sdev->dev,
684 BTRFS_DEV_STAT_READ_ERRS);
688 /* setup the context, map the logical blocks and alloc the pages */
689 ret = scrub_setup_recheck_block(sdev, &fs_info->mapping_tree, length,
690 logical, sblocks_for_recheck);
692 spin_lock(&sdev->stat_lock);
693 sdev->stat.read_errors++;
694 sdev->stat.uncorrectable_errors++;
695 spin_unlock(&sdev->stat_lock);
696 btrfs_dev_stat_inc_and_print(sdev->dev,
697 BTRFS_DEV_STAT_READ_ERRS);
700 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
701 sblock_bad = sblocks_for_recheck + failed_mirror_index;
703 /* build and submit the bios for the failed mirror, check checksums */
704 ret = scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
705 csum, generation, sdev->csum_size);
707 spin_lock(&sdev->stat_lock);
708 sdev->stat.read_errors++;
709 sdev->stat.uncorrectable_errors++;
710 spin_unlock(&sdev->stat_lock);
711 btrfs_dev_stat_inc_and_print(sdev->dev,
712 BTRFS_DEV_STAT_READ_ERRS);
716 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
717 sblock_bad->no_io_error_seen) {
719 * the error disappeared after reading page by page, or
720 * the area was part of a huge bio and other parts of the
721 * bio caused I/O errors, or the block layer merged several
722 * read requests into one and the error is caused by a
723 * different bio (usually one of the two latter cases is
726 spin_lock(&sdev->stat_lock);
727 sdev->stat.unverified_errors++;
728 spin_unlock(&sdev->stat_lock);
733 if (!sblock_bad->no_io_error_seen) {
734 spin_lock(&sdev->stat_lock);
735 sdev->stat.read_errors++;
736 spin_unlock(&sdev->stat_lock);
737 if (__ratelimit(&_rs))
738 scrub_print_warning("i/o error", sblock_to_check);
739 btrfs_dev_stat_inc_and_print(sdev->dev,
740 BTRFS_DEV_STAT_READ_ERRS);
741 } else if (sblock_bad->checksum_error) {
742 spin_lock(&sdev->stat_lock);
743 sdev->stat.csum_errors++;
744 spin_unlock(&sdev->stat_lock);
745 if (__ratelimit(&_rs))
746 scrub_print_warning("checksum error", sblock_to_check);
747 btrfs_dev_stat_inc_and_print(sdev->dev,
748 BTRFS_DEV_STAT_CORRUPTION_ERRS);
749 } else if (sblock_bad->header_error) {
750 spin_lock(&sdev->stat_lock);
751 sdev->stat.verify_errors++;
752 spin_unlock(&sdev->stat_lock);
753 if (__ratelimit(&_rs))
754 scrub_print_warning("checksum/header error",
756 if (sblock_bad->generation_error)
757 btrfs_dev_stat_inc_and_print(sdev->dev,
758 BTRFS_DEV_STAT_GENERATION_ERRS);
760 btrfs_dev_stat_inc_and_print(sdev->dev,
761 BTRFS_DEV_STAT_CORRUPTION_ERRS);
765 goto did_not_correct_error;
767 if (!is_metadata && !have_csum) {
768 struct scrub_fixup_nodatasum *fixup_nodatasum;
771 * !is_metadata and !have_csum, this means that the data
772 * might not be COW'ed, that it might be modified
773 * concurrently. The general strategy to work on the
774 * commit root does not help in the case when COW is not
777 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
778 if (!fixup_nodatasum)
779 goto did_not_correct_error;
780 fixup_nodatasum->sdev = sdev;
781 fixup_nodatasum->logical = logical;
782 fixup_nodatasum->root = fs_info->extent_root;
783 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
785 * increment scrubs_running to prevent cancel requests from
786 * completing as long as a fixup worker is running. we must also
787 * increment scrubs_paused to prevent deadlocking on pause
788 * requests used for transactions commits (as the worker uses a
789 * transaction context). it is safe to regard the fixup worker
790 * as paused for all matters practical. effectively, we only
791 * avoid cancellation requests from completing.
793 mutex_lock(&fs_info->scrub_lock);
794 atomic_inc(&fs_info->scrubs_running);
795 atomic_inc(&fs_info->scrubs_paused);
796 mutex_unlock(&fs_info->scrub_lock);
797 atomic_inc(&sdev->fixup_cnt);
798 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
799 btrfs_queue_worker(&fs_info->scrub_workers,
800 &fixup_nodatasum->work);
805 * now build and submit the bios for the other mirrors, check
808 for (mirror_index = 0;
809 mirror_index < BTRFS_MAX_MIRRORS &&
810 sblocks_for_recheck[mirror_index].page_count > 0;
812 if (mirror_index == failed_mirror_index)
815 /* build and submit the bios, check checksums */
816 ret = scrub_recheck_block(fs_info,
817 sblocks_for_recheck + mirror_index,
818 is_metadata, have_csum, csum,
819 generation, sdev->csum_size);
821 goto did_not_correct_error;
825 * first try to pick the mirror which is completely without I/O
826 * errors and also does not have a checksum error.
827 * If one is found, and if a checksum is present, the full block
828 * that is known to contain an error is rewritten. Afterwards
829 * the block is known to be corrected.
830 * If a mirror is found which is completely correct, and no
831 * checksum is present, only those pages are rewritten that had
832 * an I/O error in the block to be repaired, since it cannot be
833 * determined, which copy of the other pages is better (and it
834 * could happen otherwise that a correct page would be
835 * overwritten by a bad one).
837 for (mirror_index = 0;
838 mirror_index < BTRFS_MAX_MIRRORS &&
839 sblocks_for_recheck[mirror_index].page_count > 0;
841 struct scrub_block *sblock_other = sblocks_for_recheck +
844 if (!sblock_other->header_error &&
845 !sblock_other->checksum_error &&
846 sblock_other->no_io_error_seen) {
847 int force_write = is_metadata || have_csum;
849 ret = scrub_repair_block_from_good_copy(sblock_bad,
853 goto corrected_error;
858 * in case of I/O errors in the area that is supposed to be
859 * repaired, continue by picking good copies of those pages.
860 * Select the good pages from mirrors to rewrite bad pages from
861 * the area to fix. Afterwards verify the checksum of the block
862 * that is supposed to be repaired. This verification step is
863 * only done for the purpose of statistic counting and for the
864 * final scrub report, whether errors remain.
865 * A perfect algorithm could make use of the checksum and try
866 * all possible combinations of pages from the different mirrors
867 * until the checksum verification succeeds. For example, when
868 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
869 * of mirror #2 is readable but the final checksum test fails,
870 * then the 2nd page of mirror #3 could be tried, whether now
871 * the final checksum succeedes. But this would be a rare
872 * exception and is therefore not implemented. At least it is
873 * avoided that the good copy is overwritten.
874 * A more useful improvement would be to pick the sectors
875 * without I/O error based on sector sizes (512 bytes on legacy
876 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
877 * mirror could be repaired by taking 512 byte of a different
878 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
879 * area are unreadable.
882 /* can only fix I/O errors from here on */
883 if (sblock_bad->no_io_error_seen)
884 goto did_not_correct_error;
887 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
888 struct scrub_page *page_bad = sblock_bad->pagev + page_num;
890 if (!page_bad->io_error)
893 for (mirror_index = 0;
894 mirror_index < BTRFS_MAX_MIRRORS &&
895 sblocks_for_recheck[mirror_index].page_count > 0;
897 struct scrub_block *sblock_other = sblocks_for_recheck +
899 struct scrub_page *page_other = sblock_other->pagev +
902 if (!page_other->io_error) {
903 ret = scrub_repair_page_from_good_copy(
904 sblock_bad, sblock_other, page_num, 0);
906 page_bad->io_error = 0;
907 break; /* succeeded for this page */
912 if (page_bad->io_error) {
913 /* did not find a mirror to copy the page from */
919 if (is_metadata || have_csum) {
921 * need to verify the checksum now that all
922 * sectors on disk are repaired (the write
923 * request for data to be repaired is on its way).
924 * Just be lazy and use scrub_recheck_block()
925 * which re-reads the data before the checksum
926 * is verified, but most likely the data comes out
929 ret = scrub_recheck_block(fs_info, sblock_bad,
930 is_metadata, have_csum, csum,
931 generation, sdev->csum_size);
932 if (!ret && !sblock_bad->header_error &&
933 !sblock_bad->checksum_error &&
934 sblock_bad->no_io_error_seen)
935 goto corrected_error;
937 goto did_not_correct_error;
940 spin_lock(&sdev->stat_lock);
941 sdev->stat.corrected_errors++;
942 spin_unlock(&sdev->stat_lock);
943 printk_ratelimited_in_rcu(KERN_ERR
944 "btrfs: fixed up error at logical %llu on dev %s\n",
945 (unsigned long long)logical,
946 rcu_str_deref(sdev->dev->name));
949 did_not_correct_error:
950 spin_lock(&sdev->stat_lock);
951 sdev->stat.uncorrectable_errors++;
952 spin_unlock(&sdev->stat_lock);
953 printk_ratelimited_in_rcu(KERN_ERR
954 "btrfs: unable to fixup (regular) error at logical %llu on dev %s\n",
955 (unsigned long long)logical,
956 rcu_str_deref(sdev->dev->name));
960 if (sblocks_for_recheck) {
961 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
963 struct scrub_block *sblock = sblocks_for_recheck +
967 for (page_index = 0; page_index < SCRUB_PAGES_PER_BIO;
969 if (sblock->pagev[page_index].page)
971 sblock->pagev[page_index].page);
973 kfree(sblocks_for_recheck);
979 static int scrub_setup_recheck_block(struct scrub_dev *sdev,
980 struct btrfs_mapping_tree *map_tree,
981 u64 length, u64 logical,
982 struct scrub_block *sblocks_for_recheck)
989 * note: the three members sdev, ref_count and outstanding_pages
990 * are not used (and not set) in the blocks that are used for
991 * the recheck procedure
996 u64 sublen = min_t(u64, length, PAGE_SIZE);
997 u64 mapped_length = sublen;
998 struct btrfs_bio *bbio = NULL;
1001 * with a length of PAGE_SIZE, each returned stripe
1002 * represents one mirror
1004 ret = btrfs_map_block(map_tree, WRITE, logical, &mapped_length,
1006 if (ret || !bbio || mapped_length < sublen) {
1011 BUG_ON(page_index >= SCRUB_PAGES_PER_BIO);
1012 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1014 struct scrub_block *sblock;
1015 struct scrub_page *page;
1017 if (mirror_index >= BTRFS_MAX_MIRRORS)
1020 sblock = sblocks_for_recheck + mirror_index;
1021 page = sblock->pagev + page_index;
1022 page->logical = logical;
1023 page->physical = bbio->stripes[mirror_index].physical;
1024 /* for missing devices, dev->bdev is NULL */
1025 page->dev = bbio->stripes[mirror_index].dev;
1026 page->mirror_num = mirror_index + 1;
1027 page->page = alloc_page(GFP_NOFS);
1029 spin_lock(&sdev->stat_lock);
1030 sdev->stat.malloc_errors++;
1031 spin_unlock(&sdev->stat_lock);
1035 sblock->page_count++;
1047 * this function will check the on disk data for checksum errors, header
1048 * errors and read I/O errors. If any I/O errors happen, the exact pages
1049 * which are errored are marked as being bad. The goal is to enable scrub
1050 * to take those pages that are not errored from all the mirrors so that
1051 * the pages that are errored in the just handled mirror can be repaired.
1053 static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
1054 struct scrub_block *sblock, int is_metadata,
1055 int have_csum, u8 *csum, u64 generation,
1060 sblock->no_io_error_seen = 1;
1061 sblock->header_error = 0;
1062 sblock->checksum_error = 0;
1064 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1067 struct scrub_page *page = sblock->pagev + page_num;
1068 DECLARE_COMPLETION_ONSTACK(complete);
1070 if (page->dev->bdev == NULL) {
1072 sblock->no_io_error_seen = 0;
1076 BUG_ON(!page->page);
1077 bio = bio_alloc(GFP_NOFS, 1);
1080 bio->bi_bdev = page->dev->bdev;
1081 bio->bi_sector = page->physical >> 9;
1082 bio->bi_end_io = scrub_complete_bio_end_io;
1083 bio->bi_private = &complete;
1085 ret = bio_add_page(bio, page->page, PAGE_SIZE, 0);
1086 if (PAGE_SIZE != ret) {
1090 btrfsic_submit_bio(READ, bio);
1092 /* this will also unplug the queue */
1093 wait_for_completion(&complete);
1095 page->io_error = !test_bit(BIO_UPTODATE, &bio->bi_flags);
1096 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1097 sblock->no_io_error_seen = 0;
1101 if (sblock->no_io_error_seen)
1102 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1103 have_csum, csum, generation,
1109 static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1110 struct scrub_block *sblock,
1111 int is_metadata, int have_csum,
1112 const u8 *csum, u64 generation,
1116 u8 calculated_csum[BTRFS_CSUM_SIZE];
1118 struct btrfs_root *root = fs_info->extent_root;
1119 void *mapped_buffer;
1121 BUG_ON(!sblock->pagev[0].page);
1123 struct btrfs_header *h;
1125 mapped_buffer = kmap_atomic(sblock->pagev[0].page);
1126 h = (struct btrfs_header *)mapped_buffer;
1128 if (sblock->pagev[0].logical != le64_to_cpu(h->bytenr) ||
1129 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1130 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1132 sblock->header_error = 1;
1133 } else if (generation != le64_to_cpu(h->generation)) {
1134 sblock->header_error = 1;
1135 sblock->generation_error = 1;
1142 mapped_buffer = kmap_atomic(sblock->pagev[0].page);
1145 for (page_num = 0;;) {
1146 if (page_num == 0 && is_metadata)
1147 crc = btrfs_csum_data(root,
1148 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1149 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1151 crc = btrfs_csum_data(root, mapped_buffer, crc,
1154 kunmap_atomic(mapped_buffer);
1156 if (page_num >= sblock->page_count)
1158 BUG_ON(!sblock->pagev[page_num].page);
1160 mapped_buffer = kmap_atomic(sblock->pagev[page_num].page);
1163 btrfs_csum_final(crc, calculated_csum);
1164 if (memcmp(calculated_csum, csum, csum_size))
1165 sblock->checksum_error = 1;
1168 static void scrub_complete_bio_end_io(struct bio *bio, int err)
1170 complete((struct completion *)bio->bi_private);
1173 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1174 struct scrub_block *sblock_good,
1180 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1183 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1194 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1195 struct scrub_block *sblock_good,
1196 int page_num, int force_write)
1198 struct scrub_page *page_bad = sblock_bad->pagev + page_num;
1199 struct scrub_page *page_good = sblock_good->pagev + page_num;
1201 BUG_ON(sblock_bad->pagev[page_num].page == NULL);
1202 BUG_ON(sblock_good->pagev[page_num].page == NULL);
1203 if (force_write || sblock_bad->header_error ||
1204 sblock_bad->checksum_error || page_bad->io_error) {
1207 DECLARE_COMPLETION_ONSTACK(complete);
1209 bio = bio_alloc(GFP_NOFS, 1);
1212 bio->bi_bdev = page_bad->dev->bdev;
1213 bio->bi_sector = page_bad->physical >> 9;
1214 bio->bi_end_io = scrub_complete_bio_end_io;
1215 bio->bi_private = &complete;
1217 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1218 if (PAGE_SIZE != ret) {
1222 btrfsic_submit_bio(WRITE, bio);
1224 /* this will also unplug the queue */
1225 wait_for_completion(&complete);
1226 if (!bio_flagged(bio, BIO_UPTODATE)) {
1227 btrfs_dev_stat_inc_and_print(page_bad->dev,
1228 BTRFS_DEV_STAT_WRITE_ERRS);
1238 static void scrub_checksum(struct scrub_block *sblock)
1243 BUG_ON(sblock->page_count < 1);
1244 flags = sblock->pagev[0].flags;
1246 if (flags & BTRFS_EXTENT_FLAG_DATA)
1247 ret = scrub_checksum_data(sblock);
1248 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1249 ret = scrub_checksum_tree_block(sblock);
1250 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1251 (void)scrub_checksum_super(sblock);
1255 scrub_handle_errored_block(sblock);
1258 static int scrub_checksum_data(struct scrub_block *sblock)
1260 struct scrub_dev *sdev = sblock->sdev;
1261 u8 csum[BTRFS_CSUM_SIZE];
1267 struct btrfs_root *root = sdev->dev->dev_root;
1271 BUG_ON(sblock->page_count < 1);
1272 if (!sblock->pagev[0].have_csum)
1275 on_disk_csum = sblock->pagev[0].csum;
1276 page = sblock->pagev[0].page;
1277 buffer = kmap_atomic(page);
1279 len = sdev->sectorsize;
1282 u64 l = min_t(u64, len, PAGE_SIZE);
1284 crc = btrfs_csum_data(root, buffer, crc, l);
1285 kunmap_atomic(buffer);
1290 BUG_ON(index >= sblock->page_count);
1291 BUG_ON(!sblock->pagev[index].page);
1292 page = sblock->pagev[index].page;
1293 buffer = kmap_atomic(page);
1296 btrfs_csum_final(crc, csum);
1297 if (memcmp(csum, on_disk_csum, sdev->csum_size))
1303 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1305 struct scrub_dev *sdev = sblock->sdev;
1306 struct btrfs_header *h;
1307 struct btrfs_root *root = sdev->dev->dev_root;
1308 struct btrfs_fs_info *fs_info = root->fs_info;
1309 u8 calculated_csum[BTRFS_CSUM_SIZE];
1310 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1312 void *mapped_buffer;
1321 BUG_ON(sblock->page_count < 1);
1322 page = sblock->pagev[0].page;
1323 mapped_buffer = kmap_atomic(page);
1324 h = (struct btrfs_header *)mapped_buffer;
1325 memcpy(on_disk_csum, h->csum, sdev->csum_size);
1328 * we don't use the getter functions here, as we
1329 * a) don't have an extent buffer and
1330 * b) the page is already kmapped
1333 if (sblock->pagev[0].logical != le64_to_cpu(h->bytenr))
1336 if (sblock->pagev[0].generation != le64_to_cpu(h->generation))
1339 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1342 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1346 BUG_ON(sdev->nodesize != sdev->leafsize);
1347 len = sdev->nodesize - BTRFS_CSUM_SIZE;
1348 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1349 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1352 u64 l = min_t(u64, len, mapped_size);
1354 crc = btrfs_csum_data(root, p, crc, l);
1355 kunmap_atomic(mapped_buffer);
1360 BUG_ON(index >= sblock->page_count);
1361 BUG_ON(!sblock->pagev[index].page);
1362 page = sblock->pagev[index].page;
1363 mapped_buffer = kmap_atomic(page);
1364 mapped_size = PAGE_SIZE;
1368 btrfs_csum_final(crc, calculated_csum);
1369 if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size))
1372 return fail || crc_fail;
1375 static int scrub_checksum_super(struct scrub_block *sblock)
1377 struct btrfs_super_block *s;
1378 struct scrub_dev *sdev = sblock->sdev;
1379 struct btrfs_root *root = sdev->dev->dev_root;
1380 struct btrfs_fs_info *fs_info = root->fs_info;
1381 u8 calculated_csum[BTRFS_CSUM_SIZE];
1382 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1384 void *mapped_buffer;
1393 BUG_ON(sblock->page_count < 1);
1394 page = sblock->pagev[0].page;
1395 mapped_buffer = kmap_atomic(page);
1396 s = (struct btrfs_super_block *)mapped_buffer;
1397 memcpy(on_disk_csum, s->csum, sdev->csum_size);
1399 if (sblock->pagev[0].logical != le64_to_cpu(s->bytenr))
1402 if (sblock->pagev[0].generation != le64_to_cpu(s->generation))
1405 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1408 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1409 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1410 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1413 u64 l = min_t(u64, len, mapped_size);
1415 crc = btrfs_csum_data(root, p, crc, l);
1416 kunmap_atomic(mapped_buffer);
1421 BUG_ON(index >= sblock->page_count);
1422 BUG_ON(!sblock->pagev[index].page);
1423 page = sblock->pagev[index].page;
1424 mapped_buffer = kmap_atomic(page);
1425 mapped_size = PAGE_SIZE;
1429 btrfs_csum_final(crc, calculated_csum);
1430 if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size))
1433 if (fail_cor + fail_gen) {
1435 * if we find an error in a super block, we just report it.
1436 * They will get written with the next transaction commit
1439 spin_lock(&sdev->stat_lock);
1440 ++sdev->stat.super_errors;
1441 spin_unlock(&sdev->stat_lock);
1443 btrfs_dev_stat_inc_and_print(sdev->dev,
1444 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1446 btrfs_dev_stat_inc_and_print(sdev->dev,
1447 BTRFS_DEV_STAT_GENERATION_ERRS);
1450 return fail_cor + fail_gen;
1453 static void scrub_block_get(struct scrub_block *sblock)
1455 atomic_inc(&sblock->ref_count);
1458 static void scrub_block_put(struct scrub_block *sblock)
1460 if (atomic_dec_and_test(&sblock->ref_count)) {
1463 for (i = 0; i < sblock->page_count; i++)
1464 if (sblock->pagev[i].page)
1465 __free_page(sblock->pagev[i].page);
1470 static void scrub_submit(struct scrub_dev *sdev)
1472 struct scrub_bio *sbio;
1474 if (sdev->curr == -1)
1477 sbio = sdev->bios[sdev->curr];
1479 atomic_inc(&sdev->in_flight);
1481 btrfsic_submit_bio(READ, sbio->bio);
1484 static int scrub_add_page_to_bio(struct scrub_dev *sdev,
1485 struct scrub_page *spage)
1487 struct scrub_block *sblock = spage->sblock;
1488 struct scrub_bio *sbio;
1493 * grab a fresh bio or wait for one to become available
1495 while (sdev->curr == -1) {
1496 spin_lock(&sdev->list_lock);
1497 sdev->curr = sdev->first_free;
1498 if (sdev->curr != -1) {
1499 sdev->first_free = sdev->bios[sdev->curr]->next_free;
1500 sdev->bios[sdev->curr]->next_free = -1;
1501 sdev->bios[sdev->curr]->page_count = 0;
1502 spin_unlock(&sdev->list_lock);
1504 spin_unlock(&sdev->list_lock);
1505 wait_event(sdev->list_wait, sdev->first_free != -1);
1508 sbio = sdev->bios[sdev->curr];
1509 if (sbio->page_count == 0) {
1512 sbio->physical = spage->physical;
1513 sbio->logical = spage->logical;
1516 bio = bio_alloc(GFP_NOFS, sdev->pages_per_bio);
1522 bio->bi_private = sbio;
1523 bio->bi_end_io = scrub_bio_end_io;
1524 bio->bi_bdev = sdev->dev->bdev;
1525 bio->bi_sector = spage->physical >> 9;
1527 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1529 sbio->logical + sbio->page_count * PAGE_SIZE !=
1535 sbio->pagev[sbio->page_count] = spage;
1536 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1537 if (ret != PAGE_SIZE) {
1538 if (sbio->page_count < 1) {
1547 scrub_block_get(sblock); /* one for the added page */
1548 atomic_inc(&sblock->outstanding_pages);
1550 if (sbio->page_count == sdev->pages_per_bio)
1556 static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len,
1557 u64 physical, u64 flags, u64 gen, int mirror_num,
1558 u8 *csum, int force)
1560 struct scrub_block *sblock;
1563 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
1565 spin_lock(&sdev->stat_lock);
1566 sdev->stat.malloc_errors++;
1567 spin_unlock(&sdev->stat_lock);
1571 /* one ref inside this function, plus one for each page later on */
1572 atomic_set(&sblock->ref_count, 1);
1573 sblock->sdev = sdev;
1574 sblock->no_io_error_seen = 1;
1576 for (index = 0; len > 0; index++) {
1577 struct scrub_page *spage = sblock->pagev + index;
1578 u64 l = min_t(u64, len, PAGE_SIZE);
1580 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
1581 spage->page = alloc_page(GFP_NOFS);
1583 spin_lock(&sdev->stat_lock);
1584 sdev->stat.malloc_errors++;
1585 spin_unlock(&sdev->stat_lock);
1588 __free_page(sblock->pagev[index].page);
1593 spage->sblock = sblock;
1594 spage->dev = sdev->dev;
1595 spage->flags = flags;
1596 spage->generation = gen;
1597 spage->logical = logical;
1598 spage->physical = physical;
1599 spage->mirror_num = mirror_num;
1601 spage->have_csum = 1;
1602 memcpy(spage->csum, csum, sdev->csum_size);
1604 spage->have_csum = 0;
1606 sblock->page_count++;
1612 BUG_ON(sblock->page_count == 0);
1613 for (index = 0; index < sblock->page_count; index++) {
1614 struct scrub_page *spage = sblock->pagev + index;
1617 ret = scrub_add_page_to_bio(sdev, spage);
1619 scrub_block_put(sblock);
1627 /* last one frees, either here or in bio completion for last page */
1628 scrub_block_put(sblock);
1632 static void scrub_bio_end_io(struct bio *bio, int err)
1634 struct scrub_bio *sbio = bio->bi_private;
1635 struct scrub_dev *sdev = sbio->sdev;
1636 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1641 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
1644 static void scrub_bio_end_io_worker(struct btrfs_work *work)
1646 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1647 struct scrub_dev *sdev = sbio->sdev;
1650 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_BIO);
1652 for (i = 0; i < sbio->page_count; i++) {
1653 struct scrub_page *spage = sbio->pagev[i];
1655 spage->io_error = 1;
1656 spage->sblock->no_io_error_seen = 0;
1660 /* now complete the scrub_block items that have all pages completed */
1661 for (i = 0; i < sbio->page_count; i++) {
1662 struct scrub_page *spage = sbio->pagev[i];
1663 struct scrub_block *sblock = spage->sblock;
1665 if (atomic_dec_and_test(&sblock->outstanding_pages))
1666 scrub_block_complete(sblock);
1667 scrub_block_put(sblock);
1671 /* what is this good for??? */
1672 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
1673 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
1674 sbio->bio->bi_phys_segments = 0;
1675 sbio->bio->bi_idx = 0;
1677 for (i = 0; i < sbio->page_count; i++) {
1679 bi = &sbio->bio->bi_io_vec[i];
1681 bi->bv_len = PAGE_SIZE;
1687 spin_lock(&sdev->list_lock);
1688 sbio->next_free = sdev->first_free;
1689 sdev->first_free = sbio->index;
1690 spin_unlock(&sdev->list_lock);
1691 atomic_dec(&sdev->in_flight);
1692 wake_up(&sdev->list_wait);
1695 static void scrub_block_complete(struct scrub_block *sblock)
1697 if (!sblock->no_io_error_seen)
1698 scrub_handle_errored_block(sblock);
1700 scrub_checksum(sblock);
1703 static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
1706 struct btrfs_ordered_sum *sum = NULL;
1709 unsigned long num_sectors;
1711 while (!list_empty(&sdev->csum_list)) {
1712 sum = list_first_entry(&sdev->csum_list,
1713 struct btrfs_ordered_sum, list);
1714 if (sum->bytenr > logical)
1716 if (sum->bytenr + sum->len > logical)
1719 ++sdev->stat.csum_discards;
1720 list_del(&sum->list);
1727 num_sectors = sum->len / sdev->sectorsize;
1728 for (i = 0; i < num_sectors; ++i) {
1729 if (sum->sums[i].bytenr == logical) {
1730 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
1735 if (ret && i == num_sectors - 1) {
1736 list_del(&sum->list);
1742 /* scrub extent tries to collect up to 64 kB for each bio */
1743 static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
1744 u64 physical, u64 flags, u64 gen, int mirror_num)
1747 u8 csum[BTRFS_CSUM_SIZE];
1750 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1751 blocksize = sdev->sectorsize;
1752 spin_lock(&sdev->stat_lock);
1753 sdev->stat.data_extents_scrubbed++;
1754 sdev->stat.data_bytes_scrubbed += len;
1755 spin_unlock(&sdev->stat_lock);
1756 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1757 BUG_ON(sdev->nodesize != sdev->leafsize);
1758 blocksize = sdev->nodesize;
1759 spin_lock(&sdev->stat_lock);
1760 sdev->stat.tree_extents_scrubbed++;
1761 sdev->stat.tree_bytes_scrubbed += len;
1762 spin_unlock(&sdev->stat_lock);
1764 blocksize = sdev->sectorsize;
1769 u64 l = min_t(u64, len, blocksize);
1772 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1773 /* push csums to sbio */
1774 have_csum = scrub_find_csum(sdev, logical, l, csum);
1776 ++sdev->stat.no_csum;
1778 ret = scrub_pages(sdev, logical, l, physical, flags, gen,
1779 mirror_num, have_csum ? csum : NULL, 0);
1789 static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
1790 struct map_lookup *map, int num, u64 base, u64 length)
1792 struct btrfs_path *path;
1793 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1794 struct btrfs_root *root = fs_info->extent_root;
1795 struct btrfs_root *csum_root = fs_info->csum_root;
1796 struct btrfs_extent_item *extent;
1797 struct blk_plug plug;
1803 struct extent_buffer *l;
1804 struct btrfs_key key;
1809 struct reada_control *reada1;
1810 struct reada_control *reada2;
1811 struct btrfs_key key_start;
1812 struct btrfs_key key_end;
1814 u64 increment = map->stripe_len;
1819 do_div(nstripes, map->stripe_len);
1820 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1821 offset = map->stripe_len * num;
1822 increment = map->stripe_len * map->num_stripes;
1824 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1825 int factor = map->num_stripes / map->sub_stripes;
1826 offset = map->stripe_len * (num / map->sub_stripes);
1827 increment = map->stripe_len * factor;
1828 mirror_num = num % map->sub_stripes + 1;
1829 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1830 increment = map->stripe_len;
1831 mirror_num = num % map->num_stripes + 1;
1832 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1833 increment = map->stripe_len;
1834 mirror_num = num % map->num_stripes + 1;
1836 increment = map->stripe_len;
1840 path = btrfs_alloc_path();
1845 * work on commit root. The related disk blocks are static as
1846 * long as COW is applied. This means, it is save to rewrite
1847 * them to repair disk errors without any race conditions
1849 path->search_commit_root = 1;
1850 path->skip_locking = 1;
1853 * trigger the readahead for extent tree csum tree and wait for
1854 * completion. During readahead, the scrub is officially paused
1855 * to not hold off transaction commits
1857 logical = base + offset;
1859 wait_event(sdev->list_wait,
1860 atomic_read(&sdev->in_flight) == 0);
1861 atomic_inc(&fs_info->scrubs_paused);
1862 wake_up(&fs_info->scrub_pause_wait);
1864 /* FIXME it might be better to start readahead at commit root */
1865 key_start.objectid = logical;
1866 key_start.type = BTRFS_EXTENT_ITEM_KEY;
1867 key_start.offset = (u64)0;
1868 key_end.objectid = base + offset + nstripes * increment;
1869 key_end.type = BTRFS_EXTENT_ITEM_KEY;
1870 key_end.offset = (u64)0;
1871 reada1 = btrfs_reada_add(root, &key_start, &key_end);
1873 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1874 key_start.type = BTRFS_EXTENT_CSUM_KEY;
1875 key_start.offset = logical;
1876 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1877 key_end.type = BTRFS_EXTENT_CSUM_KEY;
1878 key_end.offset = base + offset + nstripes * increment;
1879 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
1881 if (!IS_ERR(reada1))
1882 btrfs_reada_wait(reada1);
1883 if (!IS_ERR(reada2))
1884 btrfs_reada_wait(reada2);
1886 mutex_lock(&fs_info->scrub_lock);
1887 while (atomic_read(&fs_info->scrub_pause_req)) {
1888 mutex_unlock(&fs_info->scrub_lock);
1889 wait_event(fs_info->scrub_pause_wait,
1890 atomic_read(&fs_info->scrub_pause_req) == 0);
1891 mutex_lock(&fs_info->scrub_lock);
1893 atomic_dec(&fs_info->scrubs_paused);
1894 mutex_unlock(&fs_info->scrub_lock);
1895 wake_up(&fs_info->scrub_pause_wait);
1898 * collect all data csums for the stripe to avoid seeking during
1899 * the scrub. This might currently (crc32) end up to be about 1MB
1901 blk_start_plug(&plug);
1904 * now find all extents for each stripe and scrub them
1906 logical = base + offset;
1907 physical = map->stripes[num].physical;
1909 for (i = 0; i < nstripes; ++i) {
1913 if (atomic_read(&fs_info->scrub_cancel_req) ||
1914 atomic_read(&sdev->cancel_req)) {
1919 * check to see if we have to pause
1921 if (atomic_read(&fs_info->scrub_pause_req)) {
1922 /* push queued extents */
1924 wait_event(sdev->list_wait,
1925 atomic_read(&sdev->in_flight) == 0);
1926 atomic_inc(&fs_info->scrubs_paused);
1927 wake_up(&fs_info->scrub_pause_wait);
1928 mutex_lock(&fs_info->scrub_lock);
1929 while (atomic_read(&fs_info->scrub_pause_req)) {
1930 mutex_unlock(&fs_info->scrub_lock);
1931 wait_event(fs_info->scrub_pause_wait,
1932 atomic_read(&fs_info->scrub_pause_req) == 0);
1933 mutex_lock(&fs_info->scrub_lock);
1935 atomic_dec(&fs_info->scrubs_paused);
1936 mutex_unlock(&fs_info->scrub_lock);
1937 wake_up(&fs_info->scrub_pause_wait);
1940 ret = btrfs_lookup_csums_range(csum_root, logical,
1941 logical + map->stripe_len - 1,
1942 &sdev->csum_list, 1);
1946 key.objectid = logical;
1947 key.type = BTRFS_EXTENT_ITEM_KEY;
1948 key.offset = (u64)0;
1950 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1954 ret = btrfs_previous_item(root, path, 0,
1955 BTRFS_EXTENT_ITEM_KEY);
1959 /* there's no smaller item, so stick with the
1961 btrfs_release_path(path);
1962 ret = btrfs_search_slot(NULL, root, &key,
1971 slot = path->slots[0];
1972 if (slot >= btrfs_header_nritems(l)) {
1973 ret = btrfs_next_leaf(root, path);
1981 btrfs_item_key_to_cpu(l, &key, slot);
1983 if (key.objectid + key.offset <= logical)
1986 if (key.objectid >= logical + map->stripe_len)
1989 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1992 extent = btrfs_item_ptr(l, slot,
1993 struct btrfs_extent_item);
1994 flags = btrfs_extent_flags(l, extent);
1995 generation = btrfs_extent_generation(l, extent);
1997 if (key.objectid < logical &&
1998 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
2000 "btrfs scrub: tree block %llu spanning "
2001 "stripes, ignored. logical=%llu\n",
2002 (unsigned long long)key.objectid,
2003 (unsigned long long)logical);
2008 * trim extent to this stripe
2010 if (key.objectid < logical) {
2011 key.offset -= logical - key.objectid;
2012 key.objectid = logical;
2014 if (key.objectid + key.offset >
2015 logical + map->stripe_len) {
2016 key.offset = logical + map->stripe_len -
2020 ret = scrub_extent(sdev, key.objectid, key.offset,
2021 key.objectid - logical + physical,
2022 flags, generation, mirror_num);
2029 btrfs_release_path(path);
2030 logical += increment;
2031 physical += map->stripe_len;
2032 spin_lock(&sdev->stat_lock);
2033 sdev->stat.last_physical = physical;
2034 spin_unlock(&sdev->stat_lock);
2036 /* push queued extents */
2040 blk_finish_plug(&plug);
2041 btrfs_free_path(path);
2042 return ret < 0 ? ret : 0;
2045 static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
2046 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length,
2049 struct btrfs_mapping_tree *map_tree =
2050 &sdev->dev->dev_root->fs_info->mapping_tree;
2051 struct map_lookup *map;
2052 struct extent_map *em;
2056 read_lock(&map_tree->map_tree.lock);
2057 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2058 read_unlock(&map_tree->map_tree.lock);
2063 map = (struct map_lookup *)em->bdev;
2064 if (em->start != chunk_offset)
2067 if (em->len < length)
2070 for (i = 0; i < map->num_stripes; ++i) {
2071 if (map->stripes[i].dev == sdev->dev &&
2072 map->stripes[i].physical == dev_offset) {
2073 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
2079 free_extent_map(em);
2084 static noinline_for_stack
2085 int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
2087 struct btrfs_dev_extent *dev_extent = NULL;
2088 struct btrfs_path *path;
2089 struct btrfs_root *root = sdev->dev->dev_root;
2090 struct btrfs_fs_info *fs_info = root->fs_info;
2097 struct extent_buffer *l;
2098 struct btrfs_key key;
2099 struct btrfs_key found_key;
2100 struct btrfs_block_group_cache *cache;
2102 path = btrfs_alloc_path();
2107 path->search_commit_root = 1;
2108 path->skip_locking = 1;
2110 key.objectid = sdev->dev->devid;
2112 key.type = BTRFS_DEV_EXTENT_KEY;
2116 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2120 if (path->slots[0] >=
2121 btrfs_header_nritems(path->nodes[0])) {
2122 ret = btrfs_next_leaf(root, path);
2129 slot = path->slots[0];
2131 btrfs_item_key_to_cpu(l, &found_key, slot);
2133 if (found_key.objectid != sdev->dev->devid)
2136 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
2139 if (found_key.offset >= end)
2142 if (found_key.offset < key.offset)
2145 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2146 length = btrfs_dev_extent_length(l, dev_extent);
2148 if (found_key.offset + length <= start) {
2149 key.offset = found_key.offset + length;
2150 btrfs_release_path(path);
2154 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2155 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2156 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2159 * get a reference on the corresponding block group to prevent
2160 * the chunk from going away while we scrub it
2162 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2167 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
2168 chunk_offset, length, found_key.offset);
2169 btrfs_put_block_group(cache);
2173 key.offset = found_key.offset + length;
2174 btrfs_release_path(path);
2177 btrfs_free_path(path);
2180 * ret can still be 1 from search_slot or next_leaf,
2181 * that's not an error
2183 return ret < 0 ? ret : 0;
2186 static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
2192 struct btrfs_device *device = sdev->dev;
2193 struct btrfs_root *root = device->dev_root;
2195 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2198 gen = root->fs_info->last_trans_committed;
2200 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2201 bytenr = btrfs_sb_offset(i);
2202 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
2205 ret = scrub_pages(sdev, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
2206 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
2210 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
2216 * get a reference count on fs_info->scrub_workers. start worker if necessary
2218 static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
2220 struct btrfs_fs_info *fs_info = root->fs_info;
2223 mutex_lock(&fs_info->scrub_lock);
2224 if (fs_info->scrub_workers_refcnt == 0) {
2225 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2226 fs_info->thread_pool_size, &fs_info->generic_worker);
2227 fs_info->scrub_workers.idle_thresh = 4;
2228 ret = btrfs_start_workers(&fs_info->scrub_workers);
2232 ++fs_info->scrub_workers_refcnt;
2234 mutex_unlock(&fs_info->scrub_lock);
2239 static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
2241 struct btrfs_fs_info *fs_info = root->fs_info;
2243 mutex_lock(&fs_info->scrub_lock);
2244 if (--fs_info->scrub_workers_refcnt == 0)
2245 btrfs_stop_workers(&fs_info->scrub_workers);
2246 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2247 mutex_unlock(&fs_info->scrub_lock);
2251 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
2252 struct btrfs_scrub_progress *progress, int readonly)
2254 struct scrub_dev *sdev;
2255 struct btrfs_fs_info *fs_info = root->fs_info;
2257 struct btrfs_device *dev;
2259 if (btrfs_fs_closing(root->fs_info))
2263 * check some assumptions
2265 if (root->nodesize != root->leafsize) {
2267 "btrfs_scrub: size assumption nodesize == leafsize (%d == %d) fails\n",
2268 root->nodesize, root->leafsize);
2272 if (root->nodesize > BTRFS_STRIPE_LEN) {
2274 * in this case scrub is unable to calculate the checksum
2275 * the way scrub is implemented. Do not handle this
2276 * situation at all because it won't ever happen.
2279 "btrfs_scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails\n",
2280 root->nodesize, BTRFS_STRIPE_LEN);
2284 if (root->sectorsize != PAGE_SIZE) {
2285 /* not supported for data w/o checksums */
2287 "btrfs_scrub: size assumption sectorsize != PAGE_SIZE (%d != %lld) fails\n",
2288 root->sectorsize, (unsigned long long)PAGE_SIZE);
2292 ret = scrub_workers_get(root);
2296 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2297 dev = btrfs_find_device(root, devid, NULL, NULL);
2298 if (!dev || dev->missing) {
2299 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2300 scrub_workers_put(root);
2303 mutex_lock(&fs_info->scrub_lock);
2305 if (!dev->in_fs_metadata) {
2306 mutex_unlock(&fs_info->scrub_lock);
2307 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2308 scrub_workers_put(root);
2312 if (dev->scrub_device) {
2313 mutex_unlock(&fs_info->scrub_lock);
2314 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2315 scrub_workers_put(root);
2316 return -EINPROGRESS;
2318 sdev = scrub_setup_dev(dev);
2320 mutex_unlock(&fs_info->scrub_lock);
2321 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2322 scrub_workers_put(root);
2323 return PTR_ERR(sdev);
2325 sdev->readonly = readonly;
2326 dev->scrub_device = sdev;
2328 atomic_inc(&fs_info->scrubs_running);
2329 mutex_unlock(&fs_info->scrub_lock);
2330 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2332 down_read(&fs_info->scrub_super_lock);
2333 ret = scrub_supers(sdev);
2334 up_read(&fs_info->scrub_super_lock);
2337 ret = scrub_enumerate_chunks(sdev, start, end);
2339 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
2340 atomic_dec(&fs_info->scrubs_running);
2341 wake_up(&fs_info->scrub_pause_wait);
2343 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
2346 memcpy(progress, &sdev->stat, sizeof(*progress));
2348 mutex_lock(&fs_info->scrub_lock);
2349 dev->scrub_device = NULL;
2350 mutex_unlock(&fs_info->scrub_lock);
2352 scrub_free_dev(sdev);
2353 scrub_workers_put(root);
2358 void btrfs_scrub_pause(struct btrfs_root *root)
2360 struct btrfs_fs_info *fs_info = root->fs_info;
2362 mutex_lock(&fs_info->scrub_lock);
2363 atomic_inc(&fs_info->scrub_pause_req);
2364 while (atomic_read(&fs_info->scrubs_paused) !=
2365 atomic_read(&fs_info->scrubs_running)) {
2366 mutex_unlock(&fs_info->scrub_lock);
2367 wait_event(fs_info->scrub_pause_wait,
2368 atomic_read(&fs_info->scrubs_paused) ==
2369 atomic_read(&fs_info->scrubs_running));
2370 mutex_lock(&fs_info->scrub_lock);
2372 mutex_unlock(&fs_info->scrub_lock);
2375 void btrfs_scrub_continue(struct btrfs_root *root)
2377 struct btrfs_fs_info *fs_info = root->fs_info;
2379 atomic_dec(&fs_info->scrub_pause_req);
2380 wake_up(&fs_info->scrub_pause_wait);
2383 void btrfs_scrub_pause_super(struct btrfs_root *root)
2385 down_write(&root->fs_info->scrub_super_lock);
2388 void btrfs_scrub_continue_super(struct btrfs_root *root)
2390 up_write(&root->fs_info->scrub_super_lock);
2393 int __btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
2396 mutex_lock(&fs_info->scrub_lock);
2397 if (!atomic_read(&fs_info->scrubs_running)) {
2398 mutex_unlock(&fs_info->scrub_lock);
2402 atomic_inc(&fs_info->scrub_cancel_req);
2403 while (atomic_read(&fs_info->scrubs_running)) {
2404 mutex_unlock(&fs_info->scrub_lock);
2405 wait_event(fs_info->scrub_pause_wait,
2406 atomic_read(&fs_info->scrubs_running) == 0);
2407 mutex_lock(&fs_info->scrub_lock);
2409 atomic_dec(&fs_info->scrub_cancel_req);
2410 mutex_unlock(&fs_info->scrub_lock);
2415 int btrfs_scrub_cancel(struct btrfs_root *root)
2417 return __btrfs_scrub_cancel(root->fs_info);
2420 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
2422 struct btrfs_fs_info *fs_info = root->fs_info;
2423 struct scrub_dev *sdev;
2425 mutex_lock(&fs_info->scrub_lock);
2426 sdev = dev->scrub_device;
2428 mutex_unlock(&fs_info->scrub_lock);
2431 atomic_inc(&sdev->cancel_req);
2432 while (dev->scrub_device) {
2433 mutex_unlock(&fs_info->scrub_lock);
2434 wait_event(fs_info->scrub_pause_wait,
2435 dev->scrub_device == NULL);
2436 mutex_lock(&fs_info->scrub_lock);
2438 mutex_unlock(&fs_info->scrub_lock);
2443 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
2445 struct btrfs_fs_info *fs_info = root->fs_info;
2446 struct btrfs_device *dev;
2450 * we have to hold the device_list_mutex here so the device
2451 * does not go away in cancel_dev. FIXME: find a better solution
2453 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2454 dev = btrfs_find_device(root, devid, NULL, NULL);
2456 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2459 ret = btrfs_scrub_cancel_dev(root, dev);
2460 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2465 int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
2466 struct btrfs_scrub_progress *progress)
2468 struct btrfs_device *dev;
2469 struct scrub_dev *sdev = NULL;
2471 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2472 dev = btrfs_find_device(root, devid, NULL, NULL);
2474 sdev = dev->scrub_device;
2476 memcpy(progress, &sdev->stat, sizeof(*progress));
2477 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2479 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;