1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
6 #include <linux/blkdev.h>
7 #include <linux/ratelimit.h>
8 #include <linux/sched/mm.h>
9 #include <crypto/hash.h>
13 #include "ordered-data.h"
14 #include "transaction.h"
16 #include "extent_io.h"
17 #include "dev-replace.h"
18 #include "check-integrity.h"
19 #include "rcu-string.h"
21 #include "block-group.h"
24 * This is only the first step towards a full-features scrub. It reads all
25 * extent and super block and verifies the checksums. In case a bad checksum
26 * is found or the extent cannot be read, good data will be written back if
29 * Future enhancements:
30 * - In case an unrepairable extent is encountered, track which files are
31 * affected and report them
32 * - track and record media errors, throw out bad devices
33 * - add a mode to also read unallocated space
40 * the following three values only influence the performance.
41 * The last one configures the number of parallel and outstanding I/O
42 * operations. The first two values configure an upper limit for the number
43 * of (dynamically allocated) pages that are added to a bio.
45 #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
46 #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
47 #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
50 * the following value times PAGE_SIZE needs to be large enough to match the
51 * largest node/leaf/sector size that shall be supported.
52 * Values larger than BTRFS_STRIPE_LEN are not supported.
54 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
56 struct scrub_recover {
58 struct btrfs_bio *bbio;
63 struct scrub_block *sblock;
65 struct btrfs_device *dev;
66 struct list_head list;
67 u64 flags; /* extent flags */
71 u64 physical_for_dev_replace;
74 unsigned int mirror_num:8;
75 unsigned int have_csum:1;
76 unsigned int io_error:1;
78 u8 csum[BTRFS_CSUM_SIZE];
80 struct scrub_recover *recover;
85 struct scrub_ctx *sctx;
86 struct btrfs_device *dev;
91 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
92 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
94 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
98 struct btrfs_work work;
102 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
104 atomic_t outstanding_pages;
105 refcount_t refs; /* free mem on transition to zero */
106 struct scrub_ctx *sctx;
107 struct scrub_parity *sparity;
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 */
114 /* The following is for the data used to check parity */
115 /* It is for the data with checksum */
116 unsigned int data_corrected:1;
118 struct btrfs_work work;
121 /* Used for the chunks with parity stripe such RAID5/6 */
122 struct scrub_parity {
123 struct scrub_ctx *sctx;
125 struct btrfs_device *scrub_dev;
137 struct list_head spages;
139 /* Work of parity check and repair */
140 struct btrfs_work work;
142 /* Mark the parity blocks which have data */
143 unsigned long *dbitmap;
146 * Mark the parity blocks which have data, but errors happen when
147 * read data or check data
149 unsigned long *ebitmap;
151 unsigned long bitmap[0];
155 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
156 struct btrfs_fs_info *fs_info;
159 atomic_t bios_in_flight;
160 atomic_t workers_pending;
161 spinlock_t list_lock;
162 wait_queue_head_t list_wait;
164 struct list_head csum_list;
167 int pages_per_rd_bio;
171 struct scrub_bio *wr_curr_bio;
172 struct mutex wr_lock;
173 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
174 struct btrfs_device *wr_tgtdev;
175 bool flush_all_writes;
180 struct btrfs_scrub_progress stat;
181 spinlock_t stat_lock;
184 * Use a ref counter to avoid use-after-free issues. Scrub workers
185 * decrement bios_in_flight and workers_pending and then do a wakeup
186 * on the list_wait wait queue. We must ensure the main scrub task
187 * doesn't free the scrub context before or while the workers are
188 * doing the wakeup() call.
193 struct scrub_warning {
194 struct btrfs_path *path;
195 u64 extent_item_size;
199 struct btrfs_device *dev;
202 struct full_stripe_lock {
209 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
210 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
211 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
212 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
213 struct scrub_block *sblocks_for_recheck);
214 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
215 struct scrub_block *sblock,
216 int retry_failed_mirror);
217 static void scrub_recheck_block_checksum(struct scrub_block *sblock);
218 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
219 struct scrub_block *sblock_good);
220 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
221 struct scrub_block *sblock_good,
222 int page_num, int force_write);
223 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
224 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
226 static int scrub_checksum_data(struct scrub_block *sblock);
227 static int scrub_checksum_tree_block(struct scrub_block *sblock);
228 static int scrub_checksum_super(struct scrub_block *sblock);
229 static void scrub_block_get(struct scrub_block *sblock);
230 static void scrub_block_put(struct scrub_block *sblock);
231 static void scrub_page_get(struct scrub_page *spage);
232 static void scrub_page_put(struct scrub_page *spage);
233 static void scrub_parity_get(struct scrub_parity *sparity);
234 static void scrub_parity_put(struct scrub_parity *sparity);
235 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
236 struct scrub_page *spage);
237 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
238 u64 physical, struct btrfs_device *dev, u64 flags,
239 u64 gen, int mirror_num, u8 *csum, int force,
240 u64 physical_for_dev_replace);
241 static void scrub_bio_end_io(struct bio *bio);
242 static void scrub_bio_end_io_worker(struct btrfs_work *work);
243 static void scrub_block_complete(struct scrub_block *sblock);
244 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
245 u64 extent_logical, u64 extent_len,
246 u64 *extent_physical,
247 struct btrfs_device **extent_dev,
248 int *extent_mirror_num);
249 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
250 struct scrub_page *spage);
251 static void scrub_wr_submit(struct scrub_ctx *sctx);
252 static void scrub_wr_bio_end_io(struct bio *bio);
253 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
254 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
255 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
256 static void scrub_put_ctx(struct scrub_ctx *sctx);
258 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
260 return page->recover &&
261 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
264 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
266 refcount_inc(&sctx->refs);
267 atomic_inc(&sctx->bios_in_flight);
270 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
272 atomic_dec(&sctx->bios_in_flight);
273 wake_up(&sctx->list_wait);
277 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
279 while (atomic_read(&fs_info->scrub_pause_req)) {
280 mutex_unlock(&fs_info->scrub_lock);
281 wait_event(fs_info->scrub_pause_wait,
282 atomic_read(&fs_info->scrub_pause_req) == 0);
283 mutex_lock(&fs_info->scrub_lock);
287 static void scrub_pause_on(struct btrfs_fs_info *fs_info)
289 atomic_inc(&fs_info->scrubs_paused);
290 wake_up(&fs_info->scrub_pause_wait);
293 static void scrub_pause_off(struct btrfs_fs_info *fs_info)
295 mutex_lock(&fs_info->scrub_lock);
296 __scrub_blocked_if_needed(fs_info);
297 atomic_dec(&fs_info->scrubs_paused);
298 mutex_unlock(&fs_info->scrub_lock);
300 wake_up(&fs_info->scrub_pause_wait);
303 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
305 scrub_pause_on(fs_info);
306 scrub_pause_off(fs_info);
310 * Insert new full stripe lock into full stripe locks tree
312 * Return pointer to existing or newly inserted full_stripe_lock structure if
313 * everything works well.
314 * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
316 * NOTE: caller must hold full_stripe_locks_root->lock before calling this
319 static struct full_stripe_lock *insert_full_stripe_lock(
320 struct btrfs_full_stripe_locks_tree *locks_root,
324 struct rb_node *parent = NULL;
325 struct full_stripe_lock *entry;
326 struct full_stripe_lock *ret;
328 lockdep_assert_held(&locks_root->lock);
330 p = &locks_root->root.rb_node;
333 entry = rb_entry(parent, struct full_stripe_lock, node);
334 if (fstripe_logical < entry->logical) {
336 } else if (fstripe_logical > entry->logical) {
347 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
349 return ERR_PTR(-ENOMEM);
350 ret->logical = fstripe_logical;
352 mutex_init(&ret->mutex);
354 rb_link_node(&ret->node, parent, p);
355 rb_insert_color(&ret->node, &locks_root->root);
360 * Search for a full stripe lock of a block group
362 * Return pointer to existing full stripe lock if found
363 * Return NULL if not found
365 static struct full_stripe_lock *search_full_stripe_lock(
366 struct btrfs_full_stripe_locks_tree *locks_root,
369 struct rb_node *node;
370 struct full_stripe_lock *entry;
372 lockdep_assert_held(&locks_root->lock);
374 node = locks_root->root.rb_node;
376 entry = rb_entry(node, struct full_stripe_lock, node);
377 if (fstripe_logical < entry->logical)
378 node = node->rb_left;
379 else if (fstripe_logical > entry->logical)
380 node = node->rb_right;
388 * Helper to get full stripe logical from a normal bytenr.
390 * Caller must ensure @cache is a RAID56 block group.
392 static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
398 * Due to chunk item size limit, full stripe length should not be
399 * larger than U32_MAX. Just a sanity check here.
401 WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
404 * round_down() can only handle power of 2, while RAID56 full
405 * stripe length can be 64KiB * n, so we need to manually round down.
407 ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
408 cache->full_stripe_len + cache->key.objectid;
413 * Lock a full stripe to avoid concurrency of recovery and read
415 * It's only used for profiles with parities (RAID5/6), for other profiles it
418 * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
419 * So caller must call unlock_full_stripe() at the same context.
421 * Return <0 if encounters error.
423 static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
426 struct btrfs_block_group_cache *bg_cache;
427 struct btrfs_full_stripe_locks_tree *locks_root;
428 struct full_stripe_lock *existing;
433 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
439 /* Profiles not based on parity don't need full stripe lock */
440 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
442 locks_root = &bg_cache->full_stripe_locks_root;
444 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
446 /* Now insert the full stripe lock */
447 mutex_lock(&locks_root->lock);
448 existing = insert_full_stripe_lock(locks_root, fstripe_start);
449 mutex_unlock(&locks_root->lock);
450 if (IS_ERR(existing)) {
451 ret = PTR_ERR(existing);
454 mutex_lock(&existing->mutex);
457 btrfs_put_block_group(bg_cache);
462 * Unlock a full stripe.
464 * NOTE: Caller must ensure it's the same context calling corresponding
465 * lock_full_stripe().
467 * Return 0 if we unlock full stripe without problem.
468 * Return <0 for error
470 static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
473 struct btrfs_block_group_cache *bg_cache;
474 struct btrfs_full_stripe_locks_tree *locks_root;
475 struct full_stripe_lock *fstripe_lock;
480 /* If we didn't acquire full stripe lock, no need to continue */
484 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
489 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
492 locks_root = &bg_cache->full_stripe_locks_root;
493 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
495 mutex_lock(&locks_root->lock);
496 fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
497 /* Unpaired unlock_full_stripe() detected */
501 mutex_unlock(&locks_root->lock);
505 if (fstripe_lock->refs == 0) {
507 btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
508 fstripe_lock->logical);
510 fstripe_lock->refs--;
513 if (fstripe_lock->refs == 0) {
514 rb_erase(&fstripe_lock->node, &locks_root->root);
517 mutex_unlock(&locks_root->lock);
519 mutex_unlock(&fstripe_lock->mutex);
523 btrfs_put_block_group(bg_cache);
527 static void scrub_free_csums(struct scrub_ctx *sctx)
529 while (!list_empty(&sctx->csum_list)) {
530 struct btrfs_ordered_sum *sum;
531 sum = list_first_entry(&sctx->csum_list,
532 struct btrfs_ordered_sum, list);
533 list_del(&sum->list);
538 static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
545 /* this can happen when scrub is cancelled */
546 if (sctx->curr != -1) {
547 struct scrub_bio *sbio = sctx->bios[sctx->curr];
549 for (i = 0; i < sbio->page_count; i++) {
550 WARN_ON(!sbio->pagev[i]->page);
551 scrub_block_put(sbio->pagev[i]->sblock);
556 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
557 struct scrub_bio *sbio = sctx->bios[i];
564 kfree(sctx->wr_curr_bio);
565 scrub_free_csums(sctx);
569 static void scrub_put_ctx(struct scrub_ctx *sctx)
571 if (refcount_dec_and_test(&sctx->refs))
572 scrub_free_ctx(sctx);
575 static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
576 struct btrfs_fs_info *fs_info, int is_dev_replace)
578 struct scrub_ctx *sctx;
581 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
584 refcount_set(&sctx->refs, 1);
585 sctx->is_dev_replace = is_dev_replace;
586 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
588 sctx->fs_info = fs_info;
589 INIT_LIST_HEAD(&sctx->csum_list);
590 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
591 struct scrub_bio *sbio;
593 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
596 sctx->bios[i] = sbio;
600 sbio->page_count = 0;
601 btrfs_init_work(&sbio->work, scrub_bio_end_io_worker, NULL,
604 if (i != SCRUB_BIOS_PER_SCTX - 1)
605 sctx->bios[i]->next_free = i + 1;
607 sctx->bios[i]->next_free = -1;
609 sctx->first_free = 0;
610 atomic_set(&sctx->bios_in_flight, 0);
611 atomic_set(&sctx->workers_pending, 0);
612 atomic_set(&sctx->cancel_req, 0);
613 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
615 spin_lock_init(&sctx->list_lock);
616 spin_lock_init(&sctx->stat_lock);
617 init_waitqueue_head(&sctx->list_wait);
619 WARN_ON(sctx->wr_curr_bio != NULL);
620 mutex_init(&sctx->wr_lock);
621 sctx->wr_curr_bio = NULL;
622 if (is_dev_replace) {
623 WARN_ON(!fs_info->dev_replace.tgtdev);
624 sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
625 sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
626 sctx->flush_all_writes = false;
632 scrub_free_ctx(sctx);
633 return ERR_PTR(-ENOMEM);
636 static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
644 struct extent_buffer *eb;
645 struct btrfs_inode_item *inode_item;
646 struct scrub_warning *swarn = warn_ctx;
647 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
648 struct inode_fs_paths *ipath = NULL;
649 struct btrfs_root *local_root;
650 struct btrfs_key root_key;
651 struct btrfs_key key;
653 root_key.objectid = root;
654 root_key.type = BTRFS_ROOT_ITEM_KEY;
655 root_key.offset = (u64)-1;
656 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
657 if (IS_ERR(local_root)) {
658 ret = PTR_ERR(local_root);
663 * this makes the path point to (inum INODE_ITEM ioff)
666 key.type = BTRFS_INODE_ITEM_KEY;
669 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
671 btrfs_release_path(swarn->path);
675 eb = swarn->path->nodes[0];
676 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
677 struct btrfs_inode_item);
678 isize = btrfs_inode_size(eb, inode_item);
679 nlink = btrfs_inode_nlink(eb, inode_item);
680 btrfs_release_path(swarn->path);
683 * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
684 * uses GFP_NOFS in this context, so we keep it consistent but it does
685 * not seem to be strictly necessary.
687 nofs_flag = memalloc_nofs_save();
688 ipath = init_ipath(4096, local_root, swarn->path);
689 memalloc_nofs_restore(nofs_flag);
691 ret = PTR_ERR(ipath);
695 ret = paths_from_inode(inum, ipath);
701 * we deliberately ignore the bit ipath might have been too small to
702 * hold all of the paths here
704 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
705 btrfs_warn_in_rcu(fs_info,
706 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
707 swarn->errstr, swarn->logical,
708 rcu_str_deref(swarn->dev->name),
711 min(isize - offset, (u64)PAGE_SIZE), nlink,
712 (char *)(unsigned long)ipath->fspath->val[i]);
718 btrfs_warn_in_rcu(fs_info,
719 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
720 swarn->errstr, swarn->logical,
721 rcu_str_deref(swarn->dev->name),
723 root, inum, offset, ret);
729 static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
731 struct btrfs_device *dev;
732 struct btrfs_fs_info *fs_info;
733 struct btrfs_path *path;
734 struct btrfs_key found_key;
735 struct extent_buffer *eb;
736 struct btrfs_extent_item *ei;
737 struct scrub_warning swarn;
738 unsigned long ptr = 0;
746 WARN_ON(sblock->page_count < 1);
747 dev = sblock->pagev[0]->dev;
748 fs_info = sblock->sctx->fs_info;
750 path = btrfs_alloc_path();
754 swarn.physical = sblock->pagev[0]->physical;
755 swarn.logical = sblock->pagev[0]->logical;
756 swarn.errstr = errstr;
759 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
764 extent_item_pos = swarn.logical - found_key.objectid;
765 swarn.extent_item_size = found_key.offset;
768 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
769 item_size = btrfs_item_size_nr(eb, path->slots[0]);
771 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
773 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
774 item_size, &ref_root,
776 btrfs_warn_in_rcu(fs_info,
777 "%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
778 errstr, swarn.logical,
779 rcu_str_deref(dev->name),
781 ref_level ? "node" : "leaf",
782 ret < 0 ? -1 : ref_level,
783 ret < 0 ? -1 : ref_root);
785 btrfs_release_path(path);
787 btrfs_release_path(path);
790 iterate_extent_inodes(fs_info, found_key.objectid,
792 scrub_print_warning_inode, &swarn, false);
796 btrfs_free_path(path);
799 static inline void scrub_get_recover(struct scrub_recover *recover)
801 refcount_inc(&recover->refs);
804 static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
805 struct scrub_recover *recover)
807 if (refcount_dec_and_test(&recover->refs)) {
808 btrfs_bio_counter_dec(fs_info);
809 btrfs_put_bbio(recover->bbio);
815 * scrub_handle_errored_block gets called when either verification of the
816 * pages failed or the bio failed to read, e.g. with EIO. In the latter
817 * case, this function handles all pages in the bio, even though only one
819 * The goal of this function is to repair the errored block by using the
820 * contents of one of the mirrors.
822 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
824 struct scrub_ctx *sctx = sblock_to_check->sctx;
825 struct btrfs_device *dev;
826 struct btrfs_fs_info *fs_info;
828 unsigned int failed_mirror_index;
829 unsigned int is_metadata;
830 unsigned int have_csum;
831 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
832 struct scrub_block *sblock_bad;
837 bool full_stripe_locked;
838 unsigned int nofs_flag;
839 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
840 DEFAULT_RATELIMIT_BURST);
842 BUG_ON(sblock_to_check->page_count < 1);
843 fs_info = sctx->fs_info;
844 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
846 * if we find an error in a super block, we just report it.
847 * They will get written with the next transaction commit
850 spin_lock(&sctx->stat_lock);
851 ++sctx->stat.super_errors;
852 spin_unlock(&sctx->stat_lock);
855 logical = sblock_to_check->pagev[0]->logical;
856 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
857 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
858 is_metadata = !(sblock_to_check->pagev[0]->flags &
859 BTRFS_EXTENT_FLAG_DATA);
860 have_csum = sblock_to_check->pagev[0]->have_csum;
861 dev = sblock_to_check->pagev[0]->dev;
864 * We must use GFP_NOFS because the scrub task might be waiting for a
865 * worker task executing this function and in turn a transaction commit
866 * might be waiting the scrub task to pause (which needs to wait for all
867 * the worker tasks to complete before pausing).
868 * We do allocations in the workers through insert_full_stripe_lock()
869 * and scrub_add_page_to_wr_bio(), which happens down the call chain of
872 nofs_flag = memalloc_nofs_save();
874 * For RAID5/6, race can happen for a different device scrub thread.
875 * For data corruption, Parity and Data threads will both try
876 * to recovery the data.
877 * Race can lead to doubly added csum error, or even unrecoverable
880 ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
882 memalloc_nofs_restore(nofs_flag);
883 spin_lock(&sctx->stat_lock);
885 sctx->stat.malloc_errors++;
886 sctx->stat.read_errors++;
887 sctx->stat.uncorrectable_errors++;
888 spin_unlock(&sctx->stat_lock);
893 * read all mirrors one after the other. This includes to
894 * re-read the extent or metadata block that failed (that was
895 * the cause that this fixup code is called) another time,
896 * page by page this time in order to know which pages
897 * caused I/O errors and which ones are good (for all mirrors).
898 * It is the goal to handle the situation when more than one
899 * mirror contains I/O errors, but the errors do not
900 * overlap, i.e. the data can be repaired by selecting the
901 * pages from those mirrors without I/O error on the
902 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
903 * would be that mirror #1 has an I/O error on the first page,
904 * the second page is good, and mirror #2 has an I/O error on
905 * the second page, but the first page is good.
906 * Then the first page of the first mirror can be repaired by
907 * taking the first page of the second mirror, and the
908 * second page of the second mirror can be repaired by
909 * copying the contents of the 2nd page of the 1st mirror.
910 * One more note: if the pages of one mirror contain I/O
911 * errors, the checksum cannot be verified. In order to get
912 * the best data for repairing, the first attempt is to find
913 * a mirror without I/O errors and with a validated checksum.
914 * Only if this is not possible, the pages are picked from
915 * mirrors with I/O errors without considering the checksum.
916 * If the latter is the case, at the end, the checksum of the
917 * repaired area is verified in order to correctly maintain
921 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
922 sizeof(*sblocks_for_recheck), GFP_KERNEL);
923 if (!sblocks_for_recheck) {
924 spin_lock(&sctx->stat_lock);
925 sctx->stat.malloc_errors++;
926 sctx->stat.read_errors++;
927 sctx->stat.uncorrectable_errors++;
928 spin_unlock(&sctx->stat_lock);
929 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
933 /* setup the context, map the logical blocks and alloc the pages */
934 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
936 spin_lock(&sctx->stat_lock);
937 sctx->stat.read_errors++;
938 sctx->stat.uncorrectable_errors++;
939 spin_unlock(&sctx->stat_lock);
940 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
943 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
944 sblock_bad = sblocks_for_recheck + failed_mirror_index;
946 /* build and submit the bios for the failed mirror, check checksums */
947 scrub_recheck_block(fs_info, sblock_bad, 1);
949 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
950 sblock_bad->no_io_error_seen) {
952 * the error disappeared after reading page by page, or
953 * the area was part of a huge bio and other parts of the
954 * bio caused I/O errors, or the block layer merged several
955 * read requests into one and the error is caused by a
956 * different bio (usually one of the two latter cases is
959 spin_lock(&sctx->stat_lock);
960 sctx->stat.unverified_errors++;
961 sblock_to_check->data_corrected = 1;
962 spin_unlock(&sctx->stat_lock);
964 if (sctx->is_dev_replace)
965 scrub_write_block_to_dev_replace(sblock_bad);
969 if (!sblock_bad->no_io_error_seen) {
970 spin_lock(&sctx->stat_lock);
971 sctx->stat.read_errors++;
972 spin_unlock(&sctx->stat_lock);
973 if (__ratelimit(&_rs))
974 scrub_print_warning("i/o error", sblock_to_check);
975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
976 } else if (sblock_bad->checksum_error) {
977 spin_lock(&sctx->stat_lock);
978 sctx->stat.csum_errors++;
979 spin_unlock(&sctx->stat_lock);
980 if (__ratelimit(&_rs))
981 scrub_print_warning("checksum error", sblock_to_check);
982 btrfs_dev_stat_inc_and_print(dev,
983 BTRFS_DEV_STAT_CORRUPTION_ERRS);
984 } else if (sblock_bad->header_error) {
985 spin_lock(&sctx->stat_lock);
986 sctx->stat.verify_errors++;
987 spin_unlock(&sctx->stat_lock);
988 if (__ratelimit(&_rs))
989 scrub_print_warning("checksum/header error",
991 if (sblock_bad->generation_error)
992 btrfs_dev_stat_inc_and_print(dev,
993 BTRFS_DEV_STAT_GENERATION_ERRS);
995 btrfs_dev_stat_inc_and_print(dev,
996 BTRFS_DEV_STAT_CORRUPTION_ERRS);
999 if (sctx->readonly) {
1000 ASSERT(!sctx->is_dev_replace);
1005 * now build and submit the bios for the other mirrors, check
1007 * First try to pick the mirror which is completely without I/O
1008 * errors and also does not have a checksum error.
1009 * If one is found, and if a checksum is present, the full block
1010 * that is known to contain an error is rewritten. Afterwards
1011 * the block is known to be corrected.
1012 * If a mirror is found which is completely correct, and no
1013 * checksum is present, only those pages are rewritten that had
1014 * an I/O error in the block to be repaired, since it cannot be
1015 * determined, which copy of the other pages is better (and it
1016 * could happen otherwise that a correct page would be
1017 * overwritten by a bad one).
1019 for (mirror_index = 0; ;mirror_index++) {
1020 struct scrub_block *sblock_other;
1022 if (mirror_index == failed_mirror_index)
1025 /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
1026 if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1027 if (mirror_index >= BTRFS_MAX_MIRRORS)
1029 if (!sblocks_for_recheck[mirror_index].page_count)
1032 sblock_other = sblocks_for_recheck + mirror_index;
1034 struct scrub_recover *r = sblock_bad->pagev[0]->recover;
1035 int max_allowed = r->bbio->num_stripes -
1036 r->bbio->num_tgtdevs;
1038 if (mirror_index >= max_allowed)
1040 if (!sblocks_for_recheck[1].page_count)
1043 ASSERT(failed_mirror_index == 0);
1044 sblock_other = sblocks_for_recheck + 1;
1045 sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
1048 /* build and submit the bios, check checksums */
1049 scrub_recheck_block(fs_info, sblock_other, 0);
1051 if (!sblock_other->header_error &&
1052 !sblock_other->checksum_error &&
1053 sblock_other->no_io_error_seen) {
1054 if (sctx->is_dev_replace) {
1055 scrub_write_block_to_dev_replace(sblock_other);
1056 goto corrected_error;
1058 ret = scrub_repair_block_from_good_copy(
1059 sblock_bad, sblock_other);
1061 goto corrected_error;
1066 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1067 goto did_not_correct_error;
1070 * In case of I/O errors in the area that is supposed to be
1071 * repaired, continue by picking good copies of those pages.
1072 * Select the good pages from mirrors to rewrite bad pages from
1073 * the area to fix. Afterwards verify the checksum of the block
1074 * that is supposed to be repaired. This verification step is
1075 * only done for the purpose of statistic counting and for the
1076 * final scrub report, whether errors remain.
1077 * A perfect algorithm could make use of the checksum and try
1078 * all possible combinations of pages from the different mirrors
1079 * until the checksum verification succeeds. For example, when
1080 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1081 * of mirror #2 is readable but the final checksum test fails,
1082 * then the 2nd page of mirror #3 could be tried, whether now
1083 * the final checksum succeeds. But this would be a rare
1084 * exception and is therefore not implemented. At least it is
1085 * avoided that the good copy is overwritten.
1086 * A more useful improvement would be to pick the sectors
1087 * without I/O error based on sector sizes (512 bytes on legacy
1088 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1089 * mirror could be repaired by taking 512 byte of a different
1090 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1091 * area are unreadable.
1094 for (page_num = 0; page_num < sblock_bad->page_count;
1096 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1097 struct scrub_block *sblock_other = NULL;
1099 /* skip no-io-error page in scrub */
1100 if (!page_bad->io_error && !sctx->is_dev_replace)
1103 if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1105 * In case of dev replace, if raid56 rebuild process
1106 * didn't work out correct data, then copy the content
1107 * in sblock_bad to make sure target device is identical
1108 * to source device, instead of writing garbage data in
1109 * sblock_for_recheck array to target device.
1111 sblock_other = NULL;
1112 } else if (page_bad->io_error) {
1113 /* try to find no-io-error page in mirrors */
1114 for (mirror_index = 0;
1115 mirror_index < BTRFS_MAX_MIRRORS &&
1116 sblocks_for_recheck[mirror_index].page_count > 0;
1118 if (!sblocks_for_recheck[mirror_index].
1119 pagev[page_num]->io_error) {
1120 sblock_other = sblocks_for_recheck +
1129 if (sctx->is_dev_replace) {
1131 * did not find a mirror to fetch the page
1132 * from. scrub_write_page_to_dev_replace()
1133 * handles this case (page->io_error), by
1134 * filling the block with zeros before
1135 * submitting the write request
1138 sblock_other = sblock_bad;
1140 if (scrub_write_page_to_dev_replace(sblock_other,
1143 &fs_info->dev_replace.num_write_errors);
1146 } else if (sblock_other) {
1147 ret = scrub_repair_page_from_good_copy(sblock_bad,
1151 page_bad->io_error = 0;
1157 if (success && !sctx->is_dev_replace) {
1158 if (is_metadata || have_csum) {
1160 * need to verify the checksum now that all
1161 * sectors on disk are repaired (the write
1162 * request for data to be repaired is on its way).
1163 * Just be lazy and use scrub_recheck_block()
1164 * which re-reads the data before the checksum
1165 * is verified, but most likely the data comes out
1166 * of the page cache.
1168 scrub_recheck_block(fs_info, sblock_bad, 1);
1169 if (!sblock_bad->header_error &&
1170 !sblock_bad->checksum_error &&
1171 sblock_bad->no_io_error_seen)
1172 goto corrected_error;
1174 goto did_not_correct_error;
1177 spin_lock(&sctx->stat_lock);
1178 sctx->stat.corrected_errors++;
1179 sblock_to_check->data_corrected = 1;
1180 spin_unlock(&sctx->stat_lock);
1181 btrfs_err_rl_in_rcu(fs_info,
1182 "fixed up error at logical %llu on dev %s",
1183 logical, rcu_str_deref(dev->name));
1186 did_not_correct_error:
1187 spin_lock(&sctx->stat_lock);
1188 sctx->stat.uncorrectable_errors++;
1189 spin_unlock(&sctx->stat_lock);
1190 btrfs_err_rl_in_rcu(fs_info,
1191 "unable to fixup (regular) error at logical %llu on dev %s",
1192 logical, rcu_str_deref(dev->name));
1196 if (sblocks_for_recheck) {
1197 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1199 struct scrub_block *sblock = sblocks_for_recheck +
1201 struct scrub_recover *recover;
1204 for (page_index = 0; page_index < sblock->page_count;
1206 sblock->pagev[page_index]->sblock = NULL;
1207 recover = sblock->pagev[page_index]->recover;
1209 scrub_put_recover(fs_info, recover);
1210 sblock->pagev[page_index]->recover =
1213 scrub_page_put(sblock->pagev[page_index]);
1216 kfree(sblocks_for_recheck);
1219 ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
1220 memalloc_nofs_restore(nofs_flag);
1226 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1228 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1230 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1233 return (int)bbio->num_stripes;
1236 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1239 int nstripes, int mirror,
1245 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1247 for (i = 0; i < nstripes; i++) {
1248 if (raid_map[i] == RAID6_Q_STRIPE ||
1249 raid_map[i] == RAID5_P_STRIPE)
1252 if (logical >= raid_map[i] &&
1253 logical < raid_map[i] + mapped_length)
1258 *stripe_offset = logical - raid_map[i];
1260 /* The other RAID type */
1261 *stripe_index = mirror;
1266 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1267 struct scrub_block *sblocks_for_recheck)
1269 struct scrub_ctx *sctx = original_sblock->sctx;
1270 struct btrfs_fs_info *fs_info = sctx->fs_info;
1271 u64 length = original_sblock->page_count * PAGE_SIZE;
1272 u64 logical = original_sblock->pagev[0]->logical;
1273 u64 generation = original_sblock->pagev[0]->generation;
1274 u64 flags = original_sblock->pagev[0]->flags;
1275 u64 have_csum = original_sblock->pagev[0]->have_csum;
1276 struct scrub_recover *recover;
1277 struct btrfs_bio *bbio;
1288 * note: the two members refs and outstanding_pages
1289 * are not used (and not set) in the blocks that are used for
1290 * the recheck procedure
1293 while (length > 0) {
1294 sublen = min_t(u64, length, PAGE_SIZE);
1295 mapped_length = sublen;
1299 * with a length of PAGE_SIZE, each returned stripe
1300 * represents one mirror
1302 btrfs_bio_counter_inc_blocked(fs_info);
1303 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1304 logical, &mapped_length, &bbio);
1305 if (ret || !bbio || mapped_length < sublen) {
1306 btrfs_put_bbio(bbio);
1307 btrfs_bio_counter_dec(fs_info);
1311 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1313 btrfs_put_bbio(bbio);
1314 btrfs_bio_counter_dec(fs_info);
1318 refcount_set(&recover->refs, 1);
1319 recover->bbio = bbio;
1320 recover->map_length = mapped_length;
1322 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1324 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1326 for (mirror_index = 0; mirror_index < nmirrors;
1328 struct scrub_block *sblock;
1329 struct scrub_page *page;
1331 sblock = sblocks_for_recheck + mirror_index;
1332 sblock->sctx = sctx;
1334 page = kzalloc(sizeof(*page), GFP_NOFS);
1337 spin_lock(&sctx->stat_lock);
1338 sctx->stat.malloc_errors++;
1339 spin_unlock(&sctx->stat_lock);
1340 scrub_put_recover(fs_info, recover);
1343 scrub_page_get(page);
1344 sblock->pagev[page_index] = page;
1345 page->sblock = sblock;
1346 page->flags = flags;
1347 page->generation = generation;
1348 page->logical = logical;
1349 page->have_csum = have_csum;
1352 original_sblock->pagev[0]->csum,
1355 scrub_stripe_index_and_offset(logical,
1364 page->physical = bbio->stripes[stripe_index].physical +
1366 page->dev = bbio->stripes[stripe_index].dev;
1368 BUG_ON(page_index >= original_sblock->page_count);
1369 page->physical_for_dev_replace =
1370 original_sblock->pagev[page_index]->
1371 physical_for_dev_replace;
1372 /* for missing devices, dev->bdev is NULL */
1373 page->mirror_num = mirror_index + 1;
1374 sblock->page_count++;
1375 page->page = alloc_page(GFP_NOFS);
1379 scrub_get_recover(recover);
1380 page->recover = recover;
1382 scrub_put_recover(fs_info, recover);
1391 static void scrub_bio_wait_endio(struct bio *bio)
1393 complete(bio->bi_private);
1396 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1398 struct scrub_page *page)
1400 DECLARE_COMPLETION_ONSTACK(done);
1404 bio->bi_iter.bi_sector = page->logical >> 9;
1405 bio->bi_private = &done;
1406 bio->bi_end_io = scrub_bio_wait_endio;
1408 mirror_num = page->sblock->pagev[0]->mirror_num;
1409 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1410 page->recover->map_length,
1415 wait_for_completion_io(&done);
1416 return blk_status_to_errno(bio->bi_status);
1419 static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
1420 struct scrub_block *sblock)
1422 struct scrub_page *first_page = sblock->pagev[0];
1426 /* All pages in sblock belong to the same stripe on the same device. */
1427 ASSERT(first_page->dev);
1428 if (!first_page->dev->bdev)
1431 bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
1432 bio_set_dev(bio, first_page->dev->bdev);
1434 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1435 struct scrub_page *page = sblock->pagev[page_num];
1437 WARN_ON(!page->page);
1438 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1441 if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
1448 scrub_recheck_block_checksum(sblock);
1452 for (page_num = 0; page_num < sblock->page_count; page_num++)
1453 sblock->pagev[page_num]->io_error = 1;
1455 sblock->no_io_error_seen = 0;
1459 * this function will check the on disk data for checksum errors, header
1460 * errors and read I/O errors. If any I/O errors happen, the exact pages
1461 * which are errored are marked as being bad. The goal is to enable scrub
1462 * to take those pages that are not errored from all the mirrors so that
1463 * the pages that are errored in the just handled mirror can be repaired.
1465 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1466 struct scrub_block *sblock,
1467 int retry_failed_mirror)
1471 sblock->no_io_error_seen = 1;
1473 /* short cut for raid56 */
1474 if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
1475 return scrub_recheck_block_on_raid56(fs_info, sblock);
1477 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1479 struct scrub_page *page = sblock->pagev[page_num];
1481 if (page->dev->bdev == NULL) {
1483 sblock->no_io_error_seen = 0;
1487 WARN_ON(!page->page);
1488 bio = btrfs_io_bio_alloc(1);
1489 bio_set_dev(bio, page->dev->bdev);
1491 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1492 bio->bi_iter.bi_sector = page->physical >> 9;
1493 bio->bi_opf = REQ_OP_READ;
1495 if (btrfsic_submit_bio_wait(bio)) {
1497 sblock->no_io_error_seen = 0;
1503 if (sblock->no_io_error_seen)
1504 scrub_recheck_block_checksum(sblock);
1507 static inline int scrub_check_fsid(u8 fsid[],
1508 struct scrub_page *spage)
1510 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1513 ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1517 static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1519 sblock->header_error = 0;
1520 sblock->checksum_error = 0;
1521 sblock->generation_error = 0;
1523 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1524 scrub_checksum_data(sblock);
1526 scrub_checksum_tree_block(sblock);
1529 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1530 struct scrub_block *sblock_good)
1535 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1538 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1548 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1549 struct scrub_block *sblock_good,
1550 int page_num, int force_write)
1552 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1553 struct scrub_page *page_good = sblock_good->pagev[page_num];
1554 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1556 BUG_ON(page_bad->page == NULL);
1557 BUG_ON(page_good->page == NULL);
1558 if (force_write || sblock_bad->header_error ||
1559 sblock_bad->checksum_error || page_bad->io_error) {
1563 if (!page_bad->dev->bdev) {
1564 btrfs_warn_rl(fs_info,
1565 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1569 bio = btrfs_io_bio_alloc(1);
1570 bio_set_dev(bio, page_bad->dev->bdev);
1571 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1572 bio->bi_opf = REQ_OP_WRITE;
1574 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1575 if (PAGE_SIZE != ret) {
1580 if (btrfsic_submit_bio_wait(bio)) {
1581 btrfs_dev_stat_inc_and_print(page_bad->dev,
1582 BTRFS_DEV_STAT_WRITE_ERRS);
1583 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1593 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1595 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1599 * This block is used for the check of the parity on the source device,
1600 * so the data needn't be written into the destination device.
1602 if (sblock->sparity)
1605 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1608 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1610 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1614 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1617 struct scrub_page *spage = sblock->pagev[page_num];
1619 BUG_ON(spage->page == NULL);
1620 if (spage->io_error) {
1621 void *mapped_buffer = kmap_atomic(spage->page);
1623 clear_page(mapped_buffer);
1624 flush_dcache_page(spage->page);
1625 kunmap_atomic(mapped_buffer);
1627 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1630 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1631 struct scrub_page *spage)
1633 struct scrub_bio *sbio;
1636 mutex_lock(&sctx->wr_lock);
1638 if (!sctx->wr_curr_bio) {
1639 sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
1641 if (!sctx->wr_curr_bio) {
1642 mutex_unlock(&sctx->wr_lock);
1645 sctx->wr_curr_bio->sctx = sctx;
1646 sctx->wr_curr_bio->page_count = 0;
1648 sbio = sctx->wr_curr_bio;
1649 if (sbio->page_count == 0) {
1652 sbio->physical = spage->physical_for_dev_replace;
1653 sbio->logical = spage->logical;
1654 sbio->dev = sctx->wr_tgtdev;
1657 bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
1661 bio->bi_private = sbio;
1662 bio->bi_end_io = scrub_wr_bio_end_io;
1663 bio_set_dev(bio, sbio->dev->bdev);
1664 bio->bi_iter.bi_sector = sbio->physical >> 9;
1665 bio->bi_opf = REQ_OP_WRITE;
1667 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1668 spage->physical_for_dev_replace ||
1669 sbio->logical + sbio->page_count * PAGE_SIZE !=
1671 scrub_wr_submit(sctx);
1675 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1676 if (ret != PAGE_SIZE) {
1677 if (sbio->page_count < 1) {
1680 mutex_unlock(&sctx->wr_lock);
1683 scrub_wr_submit(sctx);
1687 sbio->pagev[sbio->page_count] = spage;
1688 scrub_page_get(spage);
1690 if (sbio->page_count == sctx->pages_per_wr_bio)
1691 scrub_wr_submit(sctx);
1692 mutex_unlock(&sctx->wr_lock);
1697 static void scrub_wr_submit(struct scrub_ctx *sctx)
1699 struct scrub_bio *sbio;
1701 if (!sctx->wr_curr_bio)
1704 sbio = sctx->wr_curr_bio;
1705 sctx->wr_curr_bio = NULL;
1706 WARN_ON(!sbio->bio->bi_disk);
1707 scrub_pending_bio_inc(sctx);
1708 /* process all writes in a single worker thread. Then the block layer
1709 * orders the requests before sending them to the driver which
1710 * doubled the write performance on spinning disks when measured
1712 btrfsic_submit_bio(sbio->bio);
1715 static void scrub_wr_bio_end_io(struct bio *bio)
1717 struct scrub_bio *sbio = bio->bi_private;
1718 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
1720 sbio->status = bio->bi_status;
1723 btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
1724 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1727 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1729 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1730 struct scrub_ctx *sctx = sbio->sctx;
1733 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1735 struct btrfs_dev_replace *dev_replace =
1736 &sbio->sctx->fs_info->dev_replace;
1738 for (i = 0; i < sbio->page_count; i++) {
1739 struct scrub_page *spage = sbio->pagev[i];
1741 spage->io_error = 1;
1742 atomic64_inc(&dev_replace->num_write_errors);
1746 for (i = 0; i < sbio->page_count; i++)
1747 scrub_page_put(sbio->pagev[i]);
1751 scrub_pending_bio_dec(sctx);
1754 static int scrub_checksum(struct scrub_block *sblock)
1760 * No need to initialize these stats currently,
1761 * because this function only use return value
1762 * instead of these stats value.
1767 sblock->header_error = 0;
1768 sblock->generation_error = 0;
1769 sblock->checksum_error = 0;
1771 WARN_ON(sblock->page_count < 1);
1772 flags = sblock->pagev[0]->flags;
1774 if (flags & BTRFS_EXTENT_FLAG_DATA)
1775 ret = scrub_checksum_data(sblock);
1776 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1777 ret = scrub_checksum_tree_block(sblock);
1778 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1779 (void)scrub_checksum_super(sblock);
1783 scrub_handle_errored_block(sblock);
1788 static int scrub_checksum_data(struct scrub_block *sblock)
1790 struct scrub_ctx *sctx = sblock->sctx;
1791 struct btrfs_fs_info *fs_info = sctx->fs_info;
1792 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1793 u8 csum[BTRFS_CSUM_SIZE];
1800 BUG_ON(sblock->page_count < 1);
1801 if (!sblock->pagev[0]->have_csum)
1804 shash->tfm = fs_info->csum_shash;
1805 crypto_shash_init(shash);
1807 on_disk_csum = sblock->pagev[0]->csum;
1808 page = sblock->pagev[0]->page;
1809 buffer = kmap_atomic(page);
1811 len = sctx->fs_info->sectorsize;
1814 u64 l = min_t(u64, len, PAGE_SIZE);
1816 crypto_shash_update(shash, buffer, l);
1817 kunmap_atomic(buffer);
1822 BUG_ON(index >= sblock->page_count);
1823 BUG_ON(!sblock->pagev[index]->page);
1824 page = sblock->pagev[index]->page;
1825 buffer = kmap_atomic(page);
1828 crypto_shash_final(shash, csum);
1829 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1830 sblock->checksum_error = 1;
1832 return sblock->checksum_error;
1835 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1837 struct scrub_ctx *sctx = sblock->sctx;
1838 struct btrfs_header *h;
1839 struct btrfs_fs_info *fs_info = sctx->fs_info;
1840 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1841 u8 calculated_csum[BTRFS_CSUM_SIZE];
1842 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1844 void *mapped_buffer;
1850 shash->tfm = fs_info->csum_shash;
1851 crypto_shash_init(shash);
1853 BUG_ON(sblock->page_count < 1);
1854 page = sblock->pagev[0]->page;
1855 mapped_buffer = kmap_atomic(page);
1856 h = (struct btrfs_header *)mapped_buffer;
1857 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1860 * we don't use the getter functions here, as we
1861 * a) don't have an extent buffer and
1862 * b) the page is already kmapped
1864 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1865 sblock->header_error = 1;
1867 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1868 sblock->header_error = 1;
1869 sblock->generation_error = 1;
1872 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1873 sblock->header_error = 1;
1875 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1877 sblock->header_error = 1;
1879 len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
1880 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1881 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1884 u64 l = min_t(u64, len, mapped_size);
1886 crypto_shash_update(shash, p, l);
1887 kunmap_atomic(mapped_buffer);
1892 BUG_ON(index >= sblock->page_count);
1893 BUG_ON(!sblock->pagev[index]->page);
1894 page = sblock->pagev[index]->page;
1895 mapped_buffer = kmap_atomic(page);
1896 mapped_size = PAGE_SIZE;
1900 crypto_shash_final(shash, calculated_csum);
1901 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1902 sblock->checksum_error = 1;
1904 return sblock->header_error || sblock->checksum_error;
1907 static int scrub_checksum_super(struct scrub_block *sblock)
1909 struct btrfs_super_block *s;
1910 struct scrub_ctx *sctx = sblock->sctx;
1911 struct btrfs_fs_info *fs_info = sctx->fs_info;
1912 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1913 u8 calculated_csum[BTRFS_CSUM_SIZE];
1914 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1916 void *mapped_buffer;
1924 shash->tfm = fs_info->csum_shash;
1925 crypto_shash_init(shash);
1927 BUG_ON(sblock->page_count < 1);
1928 page = sblock->pagev[0]->page;
1929 mapped_buffer = kmap_atomic(page);
1930 s = (struct btrfs_super_block *)mapped_buffer;
1931 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1933 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1936 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1939 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1942 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1943 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1944 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1947 u64 l = min_t(u64, len, mapped_size);
1949 crypto_shash_update(shash, p, l);
1950 kunmap_atomic(mapped_buffer);
1955 BUG_ON(index >= sblock->page_count);
1956 BUG_ON(!sblock->pagev[index]->page);
1957 page = sblock->pagev[index]->page;
1958 mapped_buffer = kmap_atomic(page);
1959 mapped_size = PAGE_SIZE;
1963 crypto_shash_final(shash, calculated_csum);
1964 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1967 if (fail_cor + fail_gen) {
1969 * if we find an error in a super block, we just report it.
1970 * They will get written with the next transaction commit
1973 spin_lock(&sctx->stat_lock);
1974 ++sctx->stat.super_errors;
1975 spin_unlock(&sctx->stat_lock);
1977 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1978 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1980 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1981 BTRFS_DEV_STAT_GENERATION_ERRS);
1984 return fail_cor + fail_gen;
1987 static void scrub_block_get(struct scrub_block *sblock)
1989 refcount_inc(&sblock->refs);
1992 static void scrub_block_put(struct scrub_block *sblock)
1994 if (refcount_dec_and_test(&sblock->refs)) {
1997 if (sblock->sparity)
1998 scrub_parity_put(sblock->sparity);
2000 for (i = 0; i < sblock->page_count; i++)
2001 scrub_page_put(sblock->pagev[i]);
2006 static void scrub_page_get(struct scrub_page *spage)
2008 atomic_inc(&spage->refs);
2011 static void scrub_page_put(struct scrub_page *spage)
2013 if (atomic_dec_and_test(&spage->refs)) {
2015 __free_page(spage->page);
2020 static void scrub_submit(struct scrub_ctx *sctx)
2022 struct scrub_bio *sbio;
2024 if (sctx->curr == -1)
2027 sbio = sctx->bios[sctx->curr];
2029 scrub_pending_bio_inc(sctx);
2030 btrfsic_submit_bio(sbio->bio);
2033 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2034 struct scrub_page *spage)
2036 struct scrub_block *sblock = spage->sblock;
2037 struct scrub_bio *sbio;
2042 * grab a fresh bio or wait for one to become available
2044 while (sctx->curr == -1) {
2045 spin_lock(&sctx->list_lock);
2046 sctx->curr = sctx->first_free;
2047 if (sctx->curr != -1) {
2048 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2049 sctx->bios[sctx->curr]->next_free = -1;
2050 sctx->bios[sctx->curr]->page_count = 0;
2051 spin_unlock(&sctx->list_lock);
2053 spin_unlock(&sctx->list_lock);
2054 wait_event(sctx->list_wait, sctx->first_free != -1);
2057 sbio = sctx->bios[sctx->curr];
2058 if (sbio->page_count == 0) {
2061 sbio->physical = spage->physical;
2062 sbio->logical = spage->logical;
2063 sbio->dev = spage->dev;
2066 bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
2070 bio->bi_private = sbio;
2071 bio->bi_end_io = scrub_bio_end_io;
2072 bio_set_dev(bio, sbio->dev->bdev);
2073 bio->bi_iter.bi_sector = sbio->physical >> 9;
2074 bio->bi_opf = REQ_OP_READ;
2076 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2078 sbio->logical + sbio->page_count * PAGE_SIZE !=
2080 sbio->dev != spage->dev) {
2085 sbio->pagev[sbio->page_count] = spage;
2086 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2087 if (ret != PAGE_SIZE) {
2088 if (sbio->page_count < 1) {
2097 scrub_block_get(sblock); /* one for the page added to the bio */
2098 atomic_inc(&sblock->outstanding_pages);
2100 if (sbio->page_count == sctx->pages_per_rd_bio)
2106 static void scrub_missing_raid56_end_io(struct bio *bio)
2108 struct scrub_block *sblock = bio->bi_private;
2109 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2112 sblock->no_io_error_seen = 0;
2116 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2119 static void scrub_missing_raid56_worker(struct btrfs_work *work)
2121 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2122 struct scrub_ctx *sctx = sblock->sctx;
2123 struct btrfs_fs_info *fs_info = sctx->fs_info;
2125 struct btrfs_device *dev;
2127 logical = sblock->pagev[0]->logical;
2128 dev = sblock->pagev[0]->dev;
2130 if (sblock->no_io_error_seen)
2131 scrub_recheck_block_checksum(sblock);
2133 if (!sblock->no_io_error_seen) {
2134 spin_lock(&sctx->stat_lock);
2135 sctx->stat.read_errors++;
2136 spin_unlock(&sctx->stat_lock);
2137 btrfs_err_rl_in_rcu(fs_info,
2138 "IO error rebuilding logical %llu for dev %s",
2139 logical, rcu_str_deref(dev->name));
2140 } else if (sblock->header_error || sblock->checksum_error) {
2141 spin_lock(&sctx->stat_lock);
2142 sctx->stat.uncorrectable_errors++;
2143 spin_unlock(&sctx->stat_lock);
2144 btrfs_err_rl_in_rcu(fs_info,
2145 "failed to rebuild valid logical %llu for dev %s",
2146 logical, rcu_str_deref(dev->name));
2148 scrub_write_block_to_dev_replace(sblock);
2151 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2152 mutex_lock(&sctx->wr_lock);
2153 scrub_wr_submit(sctx);
2154 mutex_unlock(&sctx->wr_lock);
2157 scrub_block_put(sblock);
2158 scrub_pending_bio_dec(sctx);
2161 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2163 struct scrub_ctx *sctx = sblock->sctx;
2164 struct btrfs_fs_info *fs_info = sctx->fs_info;
2165 u64 length = sblock->page_count * PAGE_SIZE;
2166 u64 logical = sblock->pagev[0]->logical;
2167 struct btrfs_bio *bbio = NULL;
2169 struct btrfs_raid_bio *rbio;
2173 btrfs_bio_counter_inc_blocked(fs_info);
2174 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2176 if (ret || !bbio || !bbio->raid_map)
2179 if (WARN_ON(!sctx->is_dev_replace ||
2180 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2182 * We shouldn't be scrubbing a missing device. Even for dev
2183 * replace, we should only get here for RAID 5/6. We either
2184 * managed to mount something with no mirrors remaining or
2185 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2190 bio = btrfs_io_bio_alloc(0);
2191 bio->bi_iter.bi_sector = logical >> 9;
2192 bio->bi_private = sblock;
2193 bio->bi_end_io = scrub_missing_raid56_end_io;
2195 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2199 for (i = 0; i < sblock->page_count; i++) {
2200 struct scrub_page *spage = sblock->pagev[i];
2202 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2205 btrfs_init_work(&sblock->work, scrub_missing_raid56_worker, NULL, NULL);
2206 scrub_block_get(sblock);
2207 scrub_pending_bio_inc(sctx);
2208 raid56_submit_missing_rbio(rbio);
2214 btrfs_bio_counter_dec(fs_info);
2215 btrfs_put_bbio(bbio);
2216 spin_lock(&sctx->stat_lock);
2217 sctx->stat.malloc_errors++;
2218 spin_unlock(&sctx->stat_lock);
2221 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2222 u64 physical, struct btrfs_device *dev, u64 flags,
2223 u64 gen, int mirror_num, u8 *csum, int force,
2224 u64 physical_for_dev_replace)
2226 struct scrub_block *sblock;
2229 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2231 spin_lock(&sctx->stat_lock);
2232 sctx->stat.malloc_errors++;
2233 spin_unlock(&sctx->stat_lock);
2237 /* one ref inside this function, plus one for each page added to
2239 refcount_set(&sblock->refs, 1);
2240 sblock->sctx = sctx;
2241 sblock->no_io_error_seen = 1;
2243 for (index = 0; len > 0; index++) {
2244 struct scrub_page *spage;
2245 u64 l = min_t(u64, len, PAGE_SIZE);
2247 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2250 spin_lock(&sctx->stat_lock);
2251 sctx->stat.malloc_errors++;
2252 spin_unlock(&sctx->stat_lock);
2253 scrub_block_put(sblock);
2256 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2257 scrub_page_get(spage);
2258 sblock->pagev[index] = spage;
2259 spage->sblock = sblock;
2261 spage->flags = flags;
2262 spage->generation = gen;
2263 spage->logical = logical;
2264 spage->physical = physical;
2265 spage->physical_for_dev_replace = physical_for_dev_replace;
2266 spage->mirror_num = mirror_num;
2268 spage->have_csum = 1;
2269 memcpy(spage->csum, csum, sctx->csum_size);
2271 spage->have_csum = 0;
2273 sblock->page_count++;
2274 spage->page = alloc_page(GFP_KERNEL);
2280 physical_for_dev_replace += l;
2283 WARN_ON(sblock->page_count == 0);
2284 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2286 * This case should only be hit for RAID 5/6 device replace. See
2287 * the comment in scrub_missing_raid56_pages() for details.
2289 scrub_missing_raid56_pages(sblock);
2291 for (index = 0; index < sblock->page_count; index++) {
2292 struct scrub_page *spage = sblock->pagev[index];
2295 ret = scrub_add_page_to_rd_bio(sctx, spage);
2297 scrub_block_put(sblock);
2306 /* last one frees, either here or in bio completion for last page */
2307 scrub_block_put(sblock);
2311 static void scrub_bio_end_io(struct bio *bio)
2313 struct scrub_bio *sbio = bio->bi_private;
2314 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2316 sbio->status = bio->bi_status;
2319 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2322 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2324 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2325 struct scrub_ctx *sctx = sbio->sctx;
2328 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2330 for (i = 0; i < sbio->page_count; i++) {
2331 struct scrub_page *spage = sbio->pagev[i];
2333 spage->io_error = 1;
2334 spage->sblock->no_io_error_seen = 0;
2338 /* now complete the scrub_block items that have all pages completed */
2339 for (i = 0; i < sbio->page_count; i++) {
2340 struct scrub_page *spage = sbio->pagev[i];
2341 struct scrub_block *sblock = spage->sblock;
2343 if (atomic_dec_and_test(&sblock->outstanding_pages))
2344 scrub_block_complete(sblock);
2345 scrub_block_put(sblock);
2350 spin_lock(&sctx->list_lock);
2351 sbio->next_free = sctx->first_free;
2352 sctx->first_free = sbio->index;
2353 spin_unlock(&sctx->list_lock);
2355 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2356 mutex_lock(&sctx->wr_lock);
2357 scrub_wr_submit(sctx);
2358 mutex_unlock(&sctx->wr_lock);
2361 scrub_pending_bio_dec(sctx);
2364 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2365 unsigned long *bitmap,
2371 int sectorsize = sparity->sctx->fs_info->sectorsize;
2373 if (len >= sparity->stripe_len) {
2374 bitmap_set(bitmap, 0, sparity->nsectors);
2378 start -= sparity->logic_start;
2379 start = div64_u64_rem(start, sparity->stripe_len, &offset);
2380 offset = div_u64(offset, sectorsize);
2381 nsectors64 = div_u64(len, sectorsize);
2383 ASSERT(nsectors64 < UINT_MAX);
2384 nsectors = (u32)nsectors64;
2386 if (offset + nsectors <= sparity->nsectors) {
2387 bitmap_set(bitmap, offset, nsectors);
2391 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2392 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2395 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2398 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2401 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2404 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2407 static void scrub_block_complete(struct scrub_block *sblock)
2411 if (!sblock->no_io_error_seen) {
2413 scrub_handle_errored_block(sblock);
2416 * if has checksum error, write via repair mechanism in
2417 * dev replace case, otherwise write here in dev replace
2420 corrupted = scrub_checksum(sblock);
2421 if (!corrupted && sblock->sctx->is_dev_replace)
2422 scrub_write_block_to_dev_replace(sblock);
2425 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2426 u64 start = sblock->pagev[0]->logical;
2427 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2430 scrub_parity_mark_sectors_error(sblock->sparity,
2431 start, end - start);
2435 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2437 struct btrfs_ordered_sum *sum = NULL;
2438 unsigned long index;
2439 unsigned long num_sectors;
2441 while (!list_empty(&sctx->csum_list)) {
2442 sum = list_first_entry(&sctx->csum_list,
2443 struct btrfs_ordered_sum, list);
2444 if (sum->bytenr > logical)
2446 if (sum->bytenr + sum->len > logical)
2449 ++sctx->stat.csum_discards;
2450 list_del(&sum->list);
2457 index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
2458 ASSERT(index < UINT_MAX);
2460 num_sectors = sum->len / sctx->fs_info->sectorsize;
2461 memcpy(csum, sum->sums + index * sctx->csum_size, sctx->csum_size);
2462 if (index == num_sectors - 1) {
2463 list_del(&sum->list);
2469 /* scrub extent tries to collect up to 64 kB for each bio */
2470 static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
2471 u64 logical, u64 len,
2472 u64 physical, struct btrfs_device *dev, u64 flags,
2473 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2476 u8 csum[BTRFS_CSUM_SIZE];
2479 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2480 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2481 blocksize = map->stripe_len;
2483 blocksize = sctx->fs_info->sectorsize;
2484 spin_lock(&sctx->stat_lock);
2485 sctx->stat.data_extents_scrubbed++;
2486 sctx->stat.data_bytes_scrubbed += len;
2487 spin_unlock(&sctx->stat_lock);
2488 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2489 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2490 blocksize = map->stripe_len;
2492 blocksize = sctx->fs_info->nodesize;
2493 spin_lock(&sctx->stat_lock);
2494 sctx->stat.tree_extents_scrubbed++;
2495 sctx->stat.tree_bytes_scrubbed += len;
2496 spin_unlock(&sctx->stat_lock);
2498 blocksize = sctx->fs_info->sectorsize;
2503 u64 l = min_t(u64, len, blocksize);
2506 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2507 /* push csums to sbio */
2508 have_csum = scrub_find_csum(sctx, logical, csum);
2510 ++sctx->stat.no_csum;
2512 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2513 mirror_num, have_csum ? csum : NULL, 0,
2514 physical_for_dev_replace);
2520 physical_for_dev_replace += l;
2525 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2526 u64 logical, u64 len,
2527 u64 physical, struct btrfs_device *dev,
2528 u64 flags, u64 gen, int mirror_num, u8 *csum)
2530 struct scrub_ctx *sctx = sparity->sctx;
2531 struct scrub_block *sblock;
2534 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2536 spin_lock(&sctx->stat_lock);
2537 sctx->stat.malloc_errors++;
2538 spin_unlock(&sctx->stat_lock);
2542 /* one ref inside this function, plus one for each page added to
2544 refcount_set(&sblock->refs, 1);
2545 sblock->sctx = sctx;
2546 sblock->no_io_error_seen = 1;
2547 sblock->sparity = sparity;
2548 scrub_parity_get(sparity);
2550 for (index = 0; len > 0; index++) {
2551 struct scrub_page *spage;
2552 u64 l = min_t(u64, len, PAGE_SIZE);
2554 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2557 spin_lock(&sctx->stat_lock);
2558 sctx->stat.malloc_errors++;
2559 spin_unlock(&sctx->stat_lock);
2560 scrub_block_put(sblock);
2563 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2564 /* For scrub block */
2565 scrub_page_get(spage);
2566 sblock->pagev[index] = spage;
2567 /* For scrub parity */
2568 scrub_page_get(spage);
2569 list_add_tail(&spage->list, &sparity->spages);
2570 spage->sblock = sblock;
2572 spage->flags = flags;
2573 spage->generation = gen;
2574 spage->logical = logical;
2575 spage->physical = physical;
2576 spage->mirror_num = mirror_num;
2578 spage->have_csum = 1;
2579 memcpy(spage->csum, csum, sctx->csum_size);
2581 spage->have_csum = 0;
2583 sblock->page_count++;
2584 spage->page = alloc_page(GFP_KERNEL);
2592 WARN_ON(sblock->page_count == 0);
2593 for (index = 0; index < sblock->page_count; index++) {
2594 struct scrub_page *spage = sblock->pagev[index];
2597 ret = scrub_add_page_to_rd_bio(sctx, spage);
2599 scrub_block_put(sblock);
2604 /* last one frees, either here or in bio completion for last page */
2605 scrub_block_put(sblock);
2609 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2610 u64 logical, u64 len,
2611 u64 physical, struct btrfs_device *dev,
2612 u64 flags, u64 gen, int mirror_num)
2614 struct scrub_ctx *sctx = sparity->sctx;
2616 u8 csum[BTRFS_CSUM_SIZE];
2619 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2620 scrub_parity_mark_sectors_error(sparity, logical, len);
2624 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2625 blocksize = sparity->stripe_len;
2626 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2627 blocksize = sparity->stripe_len;
2629 blocksize = sctx->fs_info->sectorsize;
2634 u64 l = min_t(u64, len, blocksize);
2637 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2638 /* push csums to sbio */
2639 have_csum = scrub_find_csum(sctx, logical, csum);
2643 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2644 flags, gen, mirror_num,
2645 have_csum ? csum : NULL);
2657 * Given a physical address, this will calculate it's
2658 * logical offset. if this is a parity stripe, it will return
2659 * the most left data stripe's logical offset.
2661 * return 0 if it is a data stripe, 1 means parity stripe.
2663 static int get_raid56_logic_offset(u64 physical, int num,
2664 struct map_lookup *map, u64 *offset,
2673 const int data_stripes = nr_data_stripes(map);
2675 last_offset = (physical - map->stripes[num].physical) * data_stripes;
2677 *stripe_start = last_offset;
2679 *offset = last_offset;
2680 for (i = 0; i < data_stripes; i++) {
2681 *offset = last_offset + i * map->stripe_len;
2683 stripe_nr = div64_u64(*offset, map->stripe_len);
2684 stripe_nr = div_u64(stripe_nr, data_stripes);
2686 /* Work out the disk rotation on this stripe-set */
2687 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2688 /* calculate which stripe this data locates */
2690 stripe_index = rot % map->num_stripes;
2691 if (stripe_index == num)
2693 if (stripe_index < num)
2696 *offset = last_offset + j * map->stripe_len;
2700 static void scrub_free_parity(struct scrub_parity *sparity)
2702 struct scrub_ctx *sctx = sparity->sctx;
2703 struct scrub_page *curr, *next;
2706 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2708 spin_lock(&sctx->stat_lock);
2709 sctx->stat.read_errors += nbits;
2710 sctx->stat.uncorrectable_errors += nbits;
2711 spin_unlock(&sctx->stat_lock);
2714 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2715 list_del_init(&curr->list);
2716 scrub_page_put(curr);
2722 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2724 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2726 struct scrub_ctx *sctx = sparity->sctx;
2728 scrub_free_parity(sparity);
2729 scrub_pending_bio_dec(sctx);
2732 static void scrub_parity_bio_endio(struct bio *bio)
2734 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2735 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2738 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2743 btrfs_init_work(&sparity->work, scrub_parity_bio_endio_worker, NULL,
2745 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2748 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2750 struct scrub_ctx *sctx = sparity->sctx;
2751 struct btrfs_fs_info *fs_info = sctx->fs_info;
2753 struct btrfs_raid_bio *rbio;
2754 struct btrfs_bio *bbio = NULL;
2758 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2762 length = sparity->logic_end - sparity->logic_start;
2764 btrfs_bio_counter_inc_blocked(fs_info);
2765 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2767 if (ret || !bbio || !bbio->raid_map)
2770 bio = btrfs_io_bio_alloc(0);
2771 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2772 bio->bi_private = sparity;
2773 bio->bi_end_io = scrub_parity_bio_endio;
2775 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2776 length, sparity->scrub_dev,
2782 scrub_pending_bio_inc(sctx);
2783 raid56_parity_submit_scrub_rbio(rbio);
2789 btrfs_bio_counter_dec(fs_info);
2790 btrfs_put_bbio(bbio);
2791 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2793 spin_lock(&sctx->stat_lock);
2794 sctx->stat.malloc_errors++;
2795 spin_unlock(&sctx->stat_lock);
2797 scrub_free_parity(sparity);
2800 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2802 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2805 static void scrub_parity_get(struct scrub_parity *sparity)
2807 refcount_inc(&sparity->refs);
2810 static void scrub_parity_put(struct scrub_parity *sparity)
2812 if (!refcount_dec_and_test(&sparity->refs))
2815 scrub_parity_check_and_repair(sparity);
2818 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2819 struct map_lookup *map,
2820 struct btrfs_device *sdev,
2821 struct btrfs_path *path,
2825 struct btrfs_fs_info *fs_info = sctx->fs_info;
2826 struct btrfs_root *root = fs_info->extent_root;
2827 struct btrfs_root *csum_root = fs_info->csum_root;
2828 struct btrfs_extent_item *extent;
2829 struct btrfs_bio *bbio = NULL;
2833 struct extent_buffer *l;
2834 struct btrfs_key key;
2837 u64 extent_physical;
2840 struct btrfs_device *extent_dev;
2841 struct scrub_parity *sparity;
2844 int extent_mirror_num;
2847 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2848 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2849 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2852 spin_lock(&sctx->stat_lock);
2853 sctx->stat.malloc_errors++;
2854 spin_unlock(&sctx->stat_lock);
2858 sparity->stripe_len = map->stripe_len;
2859 sparity->nsectors = nsectors;
2860 sparity->sctx = sctx;
2861 sparity->scrub_dev = sdev;
2862 sparity->logic_start = logic_start;
2863 sparity->logic_end = logic_end;
2864 refcount_set(&sparity->refs, 1);
2865 INIT_LIST_HEAD(&sparity->spages);
2866 sparity->dbitmap = sparity->bitmap;
2867 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2870 while (logic_start < logic_end) {
2871 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2872 key.type = BTRFS_METADATA_ITEM_KEY;
2874 key.type = BTRFS_EXTENT_ITEM_KEY;
2875 key.objectid = logic_start;
2876 key.offset = (u64)-1;
2878 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2883 ret = btrfs_previous_extent_item(root, path, 0);
2887 btrfs_release_path(path);
2888 ret = btrfs_search_slot(NULL, root, &key,
2900 slot = path->slots[0];
2901 if (slot >= btrfs_header_nritems(l)) {
2902 ret = btrfs_next_leaf(root, path);
2911 btrfs_item_key_to_cpu(l, &key, slot);
2913 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2914 key.type != BTRFS_METADATA_ITEM_KEY)
2917 if (key.type == BTRFS_METADATA_ITEM_KEY)
2918 bytes = fs_info->nodesize;
2922 if (key.objectid + bytes <= logic_start)
2925 if (key.objectid >= logic_end) {
2930 while (key.objectid >= logic_start + map->stripe_len)
2931 logic_start += map->stripe_len;
2933 extent = btrfs_item_ptr(l, slot,
2934 struct btrfs_extent_item);
2935 flags = btrfs_extent_flags(l, extent);
2936 generation = btrfs_extent_generation(l, extent);
2938 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2939 (key.objectid < logic_start ||
2940 key.objectid + bytes >
2941 logic_start + map->stripe_len)) {
2943 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2944 key.objectid, logic_start);
2945 spin_lock(&sctx->stat_lock);
2946 sctx->stat.uncorrectable_errors++;
2947 spin_unlock(&sctx->stat_lock);
2951 extent_logical = key.objectid;
2954 if (extent_logical < logic_start) {
2955 extent_len -= logic_start - extent_logical;
2956 extent_logical = logic_start;
2959 if (extent_logical + extent_len >
2960 logic_start + map->stripe_len)
2961 extent_len = logic_start + map->stripe_len -
2964 scrub_parity_mark_sectors_data(sparity, extent_logical,
2967 mapped_length = extent_len;
2969 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2970 extent_logical, &mapped_length, &bbio,
2973 if (!bbio || mapped_length < extent_len)
2977 btrfs_put_bbio(bbio);
2980 extent_physical = bbio->stripes[0].physical;
2981 extent_mirror_num = bbio->mirror_num;
2982 extent_dev = bbio->stripes[0].dev;
2983 btrfs_put_bbio(bbio);
2985 ret = btrfs_lookup_csums_range(csum_root,
2987 extent_logical + extent_len - 1,
2988 &sctx->csum_list, 1);
2992 ret = scrub_extent_for_parity(sparity, extent_logical,
2999 scrub_free_csums(sctx);
3004 if (extent_logical + extent_len <
3005 key.objectid + bytes) {
3006 logic_start += map->stripe_len;
3008 if (logic_start >= logic_end) {
3013 if (logic_start < key.objectid + bytes) {
3022 btrfs_release_path(path);
3027 logic_start += map->stripe_len;
3031 scrub_parity_mark_sectors_error(sparity, logic_start,
3032 logic_end - logic_start);
3033 scrub_parity_put(sparity);
3035 mutex_lock(&sctx->wr_lock);
3036 scrub_wr_submit(sctx);
3037 mutex_unlock(&sctx->wr_lock);
3039 btrfs_release_path(path);
3040 return ret < 0 ? ret : 0;
3043 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3044 struct map_lookup *map,
3045 struct btrfs_device *scrub_dev,
3046 int num, u64 base, u64 length)
3048 struct btrfs_path *path, *ppath;
3049 struct btrfs_fs_info *fs_info = sctx->fs_info;
3050 struct btrfs_root *root = fs_info->extent_root;
3051 struct btrfs_root *csum_root = fs_info->csum_root;
3052 struct btrfs_extent_item *extent;
3053 struct blk_plug plug;
3058 struct extent_buffer *l;
3065 struct reada_control *reada1;
3066 struct reada_control *reada2;
3067 struct btrfs_key key;
3068 struct btrfs_key key_end;
3069 u64 increment = map->stripe_len;
3072 u64 extent_physical;
3076 struct btrfs_device *extent_dev;
3077 int extent_mirror_num;
3080 physical = map->stripes[num].physical;
3082 nstripes = div64_u64(length, map->stripe_len);
3083 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3084 offset = map->stripe_len * num;
3085 increment = map->stripe_len * map->num_stripes;
3087 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3088 int factor = map->num_stripes / map->sub_stripes;
3089 offset = map->stripe_len * (num / map->sub_stripes);
3090 increment = map->stripe_len * factor;
3091 mirror_num = num % map->sub_stripes + 1;
3092 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
3093 increment = map->stripe_len;
3094 mirror_num = num % map->num_stripes + 1;
3095 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3096 increment = map->stripe_len;
3097 mirror_num = num % map->num_stripes + 1;
3098 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3099 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3100 increment = map->stripe_len * nr_data_stripes(map);
3103 increment = map->stripe_len;
3107 path = btrfs_alloc_path();
3111 ppath = btrfs_alloc_path();
3113 btrfs_free_path(path);
3118 * work on commit root. The related disk blocks are static as
3119 * long as COW is applied. This means, it is save to rewrite
3120 * them to repair disk errors without any race conditions
3122 path->search_commit_root = 1;
3123 path->skip_locking = 1;
3125 ppath->search_commit_root = 1;
3126 ppath->skip_locking = 1;
3128 * trigger the readahead for extent tree csum tree and wait for
3129 * completion. During readahead, the scrub is officially paused
3130 * to not hold off transaction commits
3132 logical = base + offset;
3133 physical_end = physical + nstripes * map->stripe_len;
3134 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3135 get_raid56_logic_offset(physical_end, num,
3136 map, &logic_end, NULL);
3139 logic_end = logical + increment * nstripes;
3141 wait_event(sctx->list_wait,
3142 atomic_read(&sctx->bios_in_flight) == 0);
3143 scrub_blocked_if_needed(fs_info);
3145 /* FIXME it might be better to start readahead at commit root */
3146 key.objectid = logical;
3147 key.type = BTRFS_EXTENT_ITEM_KEY;
3148 key.offset = (u64)0;
3149 key_end.objectid = logic_end;
3150 key_end.type = BTRFS_METADATA_ITEM_KEY;
3151 key_end.offset = (u64)-1;
3152 reada1 = btrfs_reada_add(root, &key, &key_end);
3154 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3155 key.type = BTRFS_EXTENT_CSUM_KEY;
3156 key.offset = logical;
3157 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3158 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3159 key_end.offset = logic_end;
3160 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3162 if (!IS_ERR(reada1))
3163 btrfs_reada_wait(reada1);
3164 if (!IS_ERR(reada2))
3165 btrfs_reada_wait(reada2);
3169 * collect all data csums for the stripe to avoid seeking during
3170 * the scrub. This might currently (crc32) end up to be about 1MB
3172 blk_start_plug(&plug);
3175 * now find all extents for each stripe and scrub them
3178 while (physical < physical_end) {
3182 if (atomic_read(&fs_info->scrub_cancel_req) ||
3183 atomic_read(&sctx->cancel_req)) {
3188 * check to see if we have to pause
3190 if (atomic_read(&fs_info->scrub_pause_req)) {
3191 /* push queued extents */
3192 sctx->flush_all_writes = true;
3194 mutex_lock(&sctx->wr_lock);
3195 scrub_wr_submit(sctx);
3196 mutex_unlock(&sctx->wr_lock);
3197 wait_event(sctx->list_wait,
3198 atomic_read(&sctx->bios_in_flight) == 0);
3199 sctx->flush_all_writes = false;
3200 scrub_blocked_if_needed(fs_info);
3203 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3204 ret = get_raid56_logic_offset(physical, num, map,
3209 /* it is parity strip */
3210 stripe_logical += base;
3211 stripe_end = stripe_logical + increment;
3212 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3213 ppath, stripe_logical,
3221 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3222 key.type = BTRFS_METADATA_ITEM_KEY;
3224 key.type = BTRFS_EXTENT_ITEM_KEY;
3225 key.objectid = logical;
3226 key.offset = (u64)-1;
3228 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3233 ret = btrfs_previous_extent_item(root, path, 0);
3237 /* there's no smaller item, so stick with the
3239 btrfs_release_path(path);
3240 ret = btrfs_search_slot(NULL, root, &key,
3252 slot = path->slots[0];
3253 if (slot >= btrfs_header_nritems(l)) {
3254 ret = btrfs_next_leaf(root, path);
3263 btrfs_item_key_to_cpu(l, &key, slot);
3265 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3266 key.type != BTRFS_METADATA_ITEM_KEY)
3269 if (key.type == BTRFS_METADATA_ITEM_KEY)
3270 bytes = fs_info->nodesize;
3274 if (key.objectid + bytes <= logical)
3277 if (key.objectid >= logical + map->stripe_len) {
3278 /* out of this device extent */
3279 if (key.objectid >= logic_end)
3284 extent = btrfs_item_ptr(l, slot,
3285 struct btrfs_extent_item);
3286 flags = btrfs_extent_flags(l, extent);
3287 generation = btrfs_extent_generation(l, extent);
3289 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3290 (key.objectid < logical ||
3291 key.objectid + bytes >
3292 logical + map->stripe_len)) {
3294 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3295 key.objectid, logical);
3296 spin_lock(&sctx->stat_lock);
3297 sctx->stat.uncorrectable_errors++;
3298 spin_unlock(&sctx->stat_lock);
3303 extent_logical = key.objectid;
3307 * trim extent to this stripe
3309 if (extent_logical < logical) {
3310 extent_len -= logical - extent_logical;
3311 extent_logical = logical;
3313 if (extent_logical + extent_len >
3314 logical + map->stripe_len) {
3315 extent_len = logical + map->stripe_len -
3319 extent_physical = extent_logical - logical + physical;
3320 extent_dev = scrub_dev;
3321 extent_mirror_num = mirror_num;
3322 if (sctx->is_dev_replace)
3323 scrub_remap_extent(fs_info, extent_logical,
3324 extent_len, &extent_physical,
3326 &extent_mirror_num);
3328 ret = btrfs_lookup_csums_range(csum_root,
3332 &sctx->csum_list, 1);
3336 ret = scrub_extent(sctx, map, extent_logical, extent_len,
3337 extent_physical, extent_dev, flags,
3338 generation, extent_mirror_num,
3339 extent_logical - logical + physical);
3341 scrub_free_csums(sctx);
3346 if (extent_logical + extent_len <
3347 key.objectid + bytes) {
3348 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3350 * loop until we find next data stripe
3351 * or we have finished all stripes.
3354 physical += map->stripe_len;
3355 ret = get_raid56_logic_offset(physical,
3360 if (ret && physical < physical_end) {
3361 stripe_logical += base;
3362 stripe_end = stripe_logical +
3364 ret = scrub_raid56_parity(sctx,
3365 map, scrub_dev, ppath,
3373 physical += map->stripe_len;
3374 logical += increment;
3376 if (logical < key.objectid + bytes) {
3381 if (physical >= physical_end) {
3389 btrfs_release_path(path);
3391 logical += increment;
3392 physical += map->stripe_len;
3393 spin_lock(&sctx->stat_lock);
3395 sctx->stat.last_physical = map->stripes[num].physical +
3398 sctx->stat.last_physical = physical;
3399 spin_unlock(&sctx->stat_lock);
3404 /* push queued extents */
3406 mutex_lock(&sctx->wr_lock);
3407 scrub_wr_submit(sctx);
3408 mutex_unlock(&sctx->wr_lock);
3410 blk_finish_plug(&plug);
3411 btrfs_free_path(path);
3412 btrfs_free_path(ppath);
3413 return ret < 0 ? ret : 0;
3416 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3417 struct btrfs_device *scrub_dev,
3418 u64 chunk_offset, u64 length,
3420 struct btrfs_block_group_cache *cache)
3422 struct btrfs_fs_info *fs_info = sctx->fs_info;
3423 struct extent_map_tree *map_tree = &fs_info->mapping_tree;
3424 struct map_lookup *map;
3425 struct extent_map *em;
3429 read_lock(&map_tree->lock);
3430 em = lookup_extent_mapping(map_tree, chunk_offset, 1);
3431 read_unlock(&map_tree->lock);
3435 * Might have been an unused block group deleted by the cleaner
3436 * kthread or relocation.
3438 spin_lock(&cache->lock);
3439 if (!cache->removed)
3441 spin_unlock(&cache->lock);
3446 map = em->map_lookup;
3447 if (em->start != chunk_offset)
3450 if (em->len < length)
3453 for (i = 0; i < map->num_stripes; ++i) {
3454 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3455 map->stripes[i].physical == dev_offset) {
3456 ret = scrub_stripe(sctx, map, scrub_dev, i,
3457 chunk_offset, length);
3463 free_extent_map(em);
3468 static noinline_for_stack
3469 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3470 struct btrfs_device *scrub_dev, u64 start, u64 end)
3472 struct btrfs_dev_extent *dev_extent = NULL;
3473 struct btrfs_path *path;
3474 struct btrfs_fs_info *fs_info = sctx->fs_info;
3475 struct btrfs_root *root = fs_info->dev_root;
3481 struct extent_buffer *l;
3482 struct btrfs_key key;
3483 struct btrfs_key found_key;
3484 struct btrfs_block_group_cache *cache;
3485 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3487 path = btrfs_alloc_path();
3491 path->reada = READA_FORWARD;
3492 path->search_commit_root = 1;
3493 path->skip_locking = 1;
3495 key.objectid = scrub_dev->devid;
3497 key.type = BTRFS_DEV_EXTENT_KEY;
3500 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3504 if (path->slots[0] >=
3505 btrfs_header_nritems(path->nodes[0])) {
3506 ret = btrfs_next_leaf(root, path);
3519 slot = path->slots[0];
3521 btrfs_item_key_to_cpu(l, &found_key, slot);
3523 if (found_key.objectid != scrub_dev->devid)
3526 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3529 if (found_key.offset >= end)
3532 if (found_key.offset < key.offset)
3535 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3536 length = btrfs_dev_extent_length(l, dev_extent);
3538 if (found_key.offset + length <= start)
3541 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3544 * get a reference on the corresponding block group to prevent
3545 * the chunk from going away while we scrub it
3547 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3549 /* some chunks are removed but not committed to disk yet,
3550 * continue scrubbing */
3555 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3556 * to avoid deadlock caused by:
3557 * btrfs_inc_block_group_ro()
3558 * -> btrfs_wait_for_commit()
3559 * -> btrfs_commit_transaction()
3560 * -> btrfs_scrub_pause()
3562 scrub_pause_on(fs_info);
3565 * Don't do chunk preallocation for scrub.
3567 * This is especially important for SYSTEM bgs, or we can hit
3568 * -EFBIG from btrfs_finish_chunk_alloc() like:
3569 * 1. The only SYSTEM bg is marked RO.
3570 * Since SYSTEM bg is small, that's pretty common.
3571 * 2. New SYSTEM bg will be allocated
3572 * Due to regular version will allocate new chunk.
3573 * 3. New SYSTEM bg is empty and will get cleaned up
3574 * Before cleanup really happens, it's marked RO again.
3575 * 4. Empty SYSTEM bg get scrubbed
3578 * This can easily boost the amount of SYSTEM chunks if cleaner
3579 * thread can't be triggered fast enough, and use up all space
3580 * of btrfs_super_block::sys_chunk_array
3582 ret = btrfs_inc_block_group_ro(cache, false);
3583 if (!ret && sctx->is_dev_replace) {
3585 * If we are doing a device replace wait for any tasks
3586 * that started delalloc right before we set the block
3587 * group to RO mode, as they might have just allocated
3588 * an extent from it or decided they could do a nocow
3589 * write. And if any such tasks did that, wait for their
3590 * ordered extents to complete and then commit the
3591 * current transaction, so that we can later see the new
3592 * extent items in the extent tree - the ordered extents
3593 * create delayed data references (for cow writes) when
3594 * they complete, which will be run and insert the
3595 * corresponding extent items into the extent tree when
3596 * we commit the transaction they used when running
3597 * inode.c:btrfs_finish_ordered_io(). We later use
3598 * the commit root of the extent tree to find extents
3599 * to copy from the srcdev into the tgtdev, and we don't
3600 * want to miss any new extents.
3602 btrfs_wait_block_group_reservations(cache);
3603 btrfs_wait_nocow_writers(cache);
3604 ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
3605 cache->key.objectid,
3608 struct btrfs_trans_handle *trans;
3610 trans = btrfs_join_transaction(root);
3612 ret = PTR_ERR(trans);
3614 ret = btrfs_commit_transaction(trans);
3616 scrub_pause_off(fs_info);
3617 btrfs_put_block_group(cache);
3622 scrub_pause_off(fs_info);
3626 } else if (ret == -ENOSPC) {
3628 * btrfs_inc_block_group_ro return -ENOSPC when it
3629 * failed in creating new chunk for metadata.
3630 * It is not a problem for scrub/replace, because
3631 * metadata are always cowed, and our scrub paused
3632 * commit_transactions.
3637 "failed setting block group ro: %d", ret);
3638 btrfs_put_block_group(cache);
3642 down_write(&fs_info->dev_replace.rwsem);
3643 dev_replace->cursor_right = found_key.offset + length;
3644 dev_replace->cursor_left = found_key.offset;
3645 dev_replace->item_needs_writeback = 1;
3646 up_write(&dev_replace->rwsem);
3648 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3649 found_key.offset, cache);
3652 * flush, submit all pending read and write bios, afterwards
3654 * Note that in the dev replace case, a read request causes
3655 * write requests that are submitted in the read completion
3656 * worker. Therefore in the current situation, it is required
3657 * that all write requests are flushed, so that all read and
3658 * write requests are really completed when bios_in_flight
3661 sctx->flush_all_writes = true;
3663 mutex_lock(&sctx->wr_lock);
3664 scrub_wr_submit(sctx);
3665 mutex_unlock(&sctx->wr_lock);
3667 wait_event(sctx->list_wait,
3668 atomic_read(&sctx->bios_in_flight) == 0);
3670 scrub_pause_on(fs_info);
3673 * must be called before we decrease @scrub_paused.
3674 * make sure we don't block transaction commit while
3675 * we are waiting pending workers finished.
3677 wait_event(sctx->list_wait,
3678 atomic_read(&sctx->workers_pending) == 0);
3679 sctx->flush_all_writes = false;
3681 scrub_pause_off(fs_info);
3683 down_write(&fs_info->dev_replace.rwsem);
3684 dev_replace->cursor_left = dev_replace->cursor_right;
3685 dev_replace->item_needs_writeback = 1;
3686 up_write(&fs_info->dev_replace.rwsem);
3689 btrfs_dec_block_group_ro(cache);
3692 * We might have prevented the cleaner kthread from deleting
3693 * this block group if it was already unused because we raced
3694 * and set it to RO mode first. So add it back to the unused
3695 * list, otherwise it might not ever be deleted unless a manual
3696 * balance is triggered or it becomes used and unused again.
3698 spin_lock(&cache->lock);
3699 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3700 btrfs_block_group_used(&cache->item) == 0) {
3701 spin_unlock(&cache->lock);
3702 btrfs_mark_bg_unused(cache);
3704 spin_unlock(&cache->lock);
3707 btrfs_put_block_group(cache);
3710 if (sctx->is_dev_replace &&
3711 atomic64_read(&dev_replace->num_write_errors) > 0) {
3715 if (sctx->stat.malloc_errors > 0) {
3720 key.offset = found_key.offset + length;
3721 btrfs_release_path(path);
3724 btrfs_free_path(path);
3729 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3730 struct btrfs_device *scrub_dev)
3736 struct btrfs_fs_info *fs_info = sctx->fs_info;
3738 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3741 /* Seed devices of a new filesystem has their own generation. */
3742 if (scrub_dev->fs_devices != fs_info->fs_devices)
3743 gen = scrub_dev->generation;
3745 gen = fs_info->last_trans_committed;
3747 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3748 bytenr = btrfs_sb_offset(i);
3749 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3750 scrub_dev->commit_total_bytes)
3753 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3754 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3759 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3764 static void scrub_workers_put(struct btrfs_fs_info *fs_info)
3766 if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
3767 &fs_info->scrub_lock)) {
3768 struct btrfs_workqueue *scrub_workers = NULL;
3769 struct btrfs_workqueue *scrub_wr_comp = NULL;
3770 struct btrfs_workqueue *scrub_parity = NULL;
3772 scrub_workers = fs_info->scrub_workers;
3773 scrub_wr_comp = fs_info->scrub_wr_completion_workers;
3774 scrub_parity = fs_info->scrub_parity_workers;
3776 fs_info->scrub_workers = NULL;
3777 fs_info->scrub_wr_completion_workers = NULL;
3778 fs_info->scrub_parity_workers = NULL;
3779 mutex_unlock(&fs_info->scrub_lock);
3781 btrfs_destroy_workqueue(scrub_workers);
3782 btrfs_destroy_workqueue(scrub_wr_comp);
3783 btrfs_destroy_workqueue(scrub_parity);
3788 * get a reference count on fs_info->scrub_workers. start worker if necessary
3790 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3793 struct btrfs_workqueue *scrub_workers = NULL;
3794 struct btrfs_workqueue *scrub_wr_comp = NULL;
3795 struct btrfs_workqueue *scrub_parity = NULL;
3796 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3797 int max_active = fs_info->thread_pool_size;
3800 if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
3803 scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub", flags,
3804 is_dev_replace ? 1 : max_active, 4);
3806 goto fail_scrub_workers;
3808 scrub_wr_comp = btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3811 goto fail_scrub_wr_completion_workers;
3813 scrub_parity = btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3816 goto fail_scrub_parity_workers;
3818 mutex_lock(&fs_info->scrub_lock);
3819 if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
3820 ASSERT(fs_info->scrub_workers == NULL &&
3821 fs_info->scrub_wr_completion_workers == NULL &&
3822 fs_info->scrub_parity_workers == NULL);
3823 fs_info->scrub_workers = scrub_workers;
3824 fs_info->scrub_wr_completion_workers = scrub_wr_comp;
3825 fs_info->scrub_parity_workers = scrub_parity;
3826 refcount_set(&fs_info->scrub_workers_refcnt, 1);
3827 mutex_unlock(&fs_info->scrub_lock);
3830 /* Other thread raced in and created the workers for us */
3831 refcount_inc(&fs_info->scrub_workers_refcnt);
3832 mutex_unlock(&fs_info->scrub_lock);
3835 btrfs_destroy_workqueue(scrub_parity);
3836 fail_scrub_parity_workers:
3837 btrfs_destroy_workqueue(scrub_wr_comp);
3838 fail_scrub_wr_completion_workers:
3839 btrfs_destroy_workqueue(scrub_workers);
3844 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3845 u64 end, struct btrfs_scrub_progress *progress,
3846 int readonly, int is_dev_replace)
3848 struct scrub_ctx *sctx;
3850 struct btrfs_device *dev;
3851 unsigned int nofs_flag;
3852 bool need_commit = false;
3854 if (btrfs_fs_closing(fs_info))
3857 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3859 * in this case scrub is unable to calculate the checksum
3860 * the way scrub is implemented. Do not handle this
3861 * situation at all because it won't ever happen.
3864 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3870 if (fs_info->sectorsize != PAGE_SIZE) {
3871 /* not supported for data w/o checksums */
3872 btrfs_err_rl(fs_info,
3873 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3874 fs_info->sectorsize, PAGE_SIZE);
3878 if (fs_info->nodesize >
3879 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3880 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3882 * would exhaust the array bounds of pagev member in
3883 * struct scrub_block
3886 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3888 SCRUB_MAX_PAGES_PER_BLOCK,
3889 fs_info->sectorsize,
3890 SCRUB_MAX_PAGES_PER_BLOCK);
3894 /* Allocate outside of device_list_mutex */
3895 sctx = scrub_setup_ctx(fs_info, is_dev_replace);
3897 return PTR_ERR(sctx);
3899 ret = scrub_workers_get(fs_info, is_dev_replace);
3903 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3904 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
3905 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
3907 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3912 if (!is_dev_replace && !readonly &&
3913 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
3914 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3915 btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
3916 rcu_str_deref(dev->name));
3921 mutex_lock(&fs_info->scrub_lock);
3922 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3923 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
3924 mutex_unlock(&fs_info->scrub_lock);
3925 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3930 down_read(&fs_info->dev_replace.rwsem);
3931 if (dev->scrub_ctx ||
3933 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3934 up_read(&fs_info->dev_replace.rwsem);
3935 mutex_unlock(&fs_info->scrub_lock);
3936 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3940 up_read(&fs_info->dev_replace.rwsem);
3942 sctx->readonly = readonly;
3943 dev->scrub_ctx = sctx;
3944 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3947 * checking @scrub_pause_req here, we can avoid
3948 * race between committing transaction and scrubbing.
3950 __scrub_blocked_if_needed(fs_info);
3951 atomic_inc(&fs_info->scrubs_running);
3952 mutex_unlock(&fs_info->scrub_lock);
3955 * In order to avoid deadlock with reclaim when there is a transaction
3956 * trying to pause scrub, make sure we use GFP_NOFS for all the
3957 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
3958 * invoked by our callees. The pausing request is done when the
3959 * transaction commit starts, and it blocks the transaction until scrub
3960 * is paused (done at specific points at scrub_stripe() or right above
3961 * before incrementing fs_info->scrubs_running).
3963 nofs_flag = memalloc_nofs_save();
3964 if (!is_dev_replace) {
3965 u64 old_super_errors;
3967 spin_lock(&sctx->stat_lock);
3968 old_super_errors = sctx->stat.super_errors;
3969 spin_unlock(&sctx->stat_lock);
3971 btrfs_info(fs_info, "scrub: started on devid %llu", devid);
3973 * by holding device list mutex, we can
3974 * kick off writing super in log tree sync.
3976 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3977 ret = scrub_supers(sctx, dev);
3978 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3980 spin_lock(&sctx->stat_lock);
3982 * Super block errors found, but we can not commit transaction
3983 * at current context, since btrfs_commit_transaction() needs
3984 * to pause the current running scrub (hold by ourselves).
3986 if (sctx->stat.super_errors > old_super_errors && !sctx->readonly)
3988 spin_unlock(&sctx->stat_lock);
3992 ret = scrub_enumerate_chunks(sctx, dev, start, end);
3993 memalloc_nofs_restore(nofs_flag);
3995 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3996 atomic_dec(&fs_info->scrubs_running);
3997 wake_up(&fs_info->scrub_pause_wait);
3999 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
4002 memcpy(progress, &sctx->stat, sizeof(*progress));
4004 if (!is_dev_replace)
4005 btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
4006 ret ? "not finished" : "finished", devid, ret);
4008 mutex_lock(&fs_info->scrub_lock);
4009 dev->scrub_ctx = NULL;
4010 mutex_unlock(&fs_info->scrub_lock);
4012 scrub_workers_put(fs_info);
4013 scrub_put_ctx(sctx);
4016 * We found some super block errors before, now try to force a
4017 * transaction commit, as scrub has finished.
4020 struct btrfs_trans_handle *trans;
4022 trans = btrfs_start_transaction(fs_info->tree_root, 0);
4023 if (IS_ERR(trans)) {
4024 ret = PTR_ERR(trans);
4026 "scrub: failed to start transaction to fix super block errors: %d", ret);
4029 ret = btrfs_commit_transaction(trans);
4032 "scrub: failed to commit transaction to fix super block errors: %d", ret);
4036 scrub_workers_put(fs_info);
4038 scrub_free_ctx(sctx);
4043 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
4045 mutex_lock(&fs_info->scrub_lock);
4046 atomic_inc(&fs_info->scrub_pause_req);
4047 while (atomic_read(&fs_info->scrubs_paused) !=
4048 atomic_read(&fs_info->scrubs_running)) {
4049 mutex_unlock(&fs_info->scrub_lock);
4050 wait_event(fs_info->scrub_pause_wait,
4051 atomic_read(&fs_info->scrubs_paused) ==
4052 atomic_read(&fs_info->scrubs_running));
4053 mutex_lock(&fs_info->scrub_lock);
4055 mutex_unlock(&fs_info->scrub_lock);
4058 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
4060 atomic_dec(&fs_info->scrub_pause_req);
4061 wake_up(&fs_info->scrub_pause_wait);
4064 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
4066 mutex_lock(&fs_info->scrub_lock);
4067 if (!atomic_read(&fs_info->scrubs_running)) {
4068 mutex_unlock(&fs_info->scrub_lock);
4072 atomic_inc(&fs_info->scrub_cancel_req);
4073 while (atomic_read(&fs_info->scrubs_running)) {
4074 mutex_unlock(&fs_info->scrub_lock);
4075 wait_event(fs_info->scrub_pause_wait,
4076 atomic_read(&fs_info->scrubs_running) == 0);
4077 mutex_lock(&fs_info->scrub_lock);
4079 atomic_dec(&fs_info->scrub_cancel_req);
4080 mutex_unlock(&fs_info->scrub_lock);
4085 int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
4087 struct btrfs_fs_info *fs_info = dev->fs_info;
4088 struct scrub_ctx *sctx;
4090 mutex_lock(&fs_info->scrub_lock);
4091 sctx = dev->scrub_ctx;
4093 mutex_unlock(&fs_info->scrub_lock);
4096 atomic_inc(&sctx->cancel_req);
4097 while (dev->scrub_ctx) {
4098 mutex_unlock(&fs_info->scrub_lock);
4099 wait_event(fs_info->scrub_pause_wait,
4100 dev->scrub_ctx == NULL);
4101 mutex_lock(&fs_info->scrub_lock);
4103 mutex_unlock(&fs_info->scrub_lock);
4108 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4109 struct btrfs_scrub_progress *progress)
4111 struct btrfs_device *dev;
4112 struct scrub_ctx *sctx = NULL;
4114 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4115 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
4117 sctx = dev->scrub_ctx;
4119 memcpy(progress, &sctx->stat, sizeof(*progress));
4120 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4122 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4125 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4126 u64 extent_logical, u64 extent_len,
4127 u64 *extent_physical,
4128 struct btrfs_device **extent_dev,
4129 int *extent_mirror_num)
4132 struct btrfs_bio *bbio = NULL;
4135 mapped_length = extent_len;
4136 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4137 &mapped_length, &bbio, 0);
4138 if (ret || !bbio || mapped_length < extent_len ||
4139 !bbio->stripes[0].dev->bdev) {
4140 btrfs_put_bbio(bbio);
4144 *extent_physical = bbio->stripes[0].physical;
4145 *extent_mirror_num = bbio->mirror_num;
4146 *extent_dev = bbio->stripes[0].dev;
4147 btrfs_put_bbio(bbio);