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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
4 */
5
6#include <linux/blkdev.h>
7#include <linux/ratelimit.h>
8#include <linux/sched/mm.h>
9#include "ctree.h"
10#include "volumes.h"
11#include "disk-io.h"
12#include "ordered-data.h"
13#include "transaction.h"
14#include "backref.h"
15#include "extent_io.h"
16#include "dev-replace.h"
17#include "check-integrity.h"
18#include "rcu-string.h"
19#include "raid56.h"
20
21/*
22 * This is only the first step towards a full-features scrub. It reads all
23 * extent and super block and verifies the checksums. In case a bad checksum
24 * is found or the extent cannot be read, good data will be written back if
25 * any can be found.
26 *
27 * Future enhancements:
28 * - In case an unrepairable extent is encountered, track which files are
29 * affected and report them
30 * - track and record media errors, throw out bad devices
31 * - add a mode to also read unallocated space
32 */
33
34struct scrub_block;
35struct scrub_ctx;
36
37/*
38 * the following three values only influence the performance.
39 * The last one configures the number of parallel and outstanding I/O
40 * operations. The first two values configure an upper limit for the number
41 * of (dynamically allocated) pages that are added to a bio.
42 */
43#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
44#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
45#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
46
47/*
48 * the following value times PAGE_SIZE needs to be large enough to match the
49 * largest node/leaf/sector size that shall be supported.
50 * Values larger than BTRFS_STRIPE_LEN are not supported.
51 */
52#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
53
54struct scrub_recover {
55 refcount_t refs;
56 struct btrfs_bio *bbio;
57 u64 map_length;
58};
59
60struct scrub_page {
61 struct scrub_block *sblock;
62 struct page *page;
63 struct btrfs_device *dev;
64 struct list_head list;
65 u64 flags; /* extent flags */
66 u64 generation;
67 u64 logical;
68 u64 physical;
69 u64 physical_for_dev_replace;
70 atomic_t refs;
71 struct {
72 unsigned int mirror_num:8;
73 unsigned int have_csum:1;
74 unsigned int io_error:1;
75 };
76 u8 csum[BTRFS_CSUM_SIZE];
77
78 struct scrub_recover *recover;
79};
80
81struct scrub_bio {
82 int index;
83 struct scrub_ctx *sctx;
84 struct btrfs_device *dev;
85 struct bio *bio;
86 blk_status_t status;
87 u64 logical;
88 u64 physical;
89#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
90 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
91#else
92 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
93#endif
94 int page_count;
95 int next_free;
96 struct btrfs_work work;
97};
98
99struct scrub_block {
100 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
101 int page_count;
102 atomic_t outstanding_pages;
103 refcount_t refs; /* free mem on transition to zero */
104 struct scrub_ctx *sctx;
105 struct scrub_parity *sparity;
106 struct {
107 unsigned int header_error:1;
108 unsigned int checksum_error:1;
109 unsigned int no_io_error_seen:1;
110 unsigned int generation_error:1; /* also sets header_error */
111
112 /* The following is for the data used to check parity */
113 /* It is for the data with checksum */
114 unsigned int data_corrected:1;
115 };
116 struct btrfs_work work;
117};
118
119/* Used for the chunks with parity stripe such RAID5/6 */
120struct scrub_parity {
121 struct scrub_ctx *sctx;
122
123 struct btrfs_device *scrub_dev;
124
125 u64 logic_start;
126
127 u64 logic_end;
128
129 int nsectors;
130
131 u64 stripe_len;
132
133 refcount_t refs;
134
135 struct list_head spages;
136
137 /* Work of parity check and repair */
138 struct btrfs_work work;
139
140 /* Mark the parity blocks which have data */
141 unsigned long *dbitmap;
142
143 /*
144 * Mark the parity blocks which have data, but errors happen when
145 * read data or check data
146 */
147 unsigned long *ebitmap;
148
149 unsigned long bitmap[0];
150};
151
152struct scrub_ctx {
153 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
154 struct btrfs_fs_info *fs_info;
155 int first_free;
156 int curr;
157 atomic_t bios_in_flight;
158 atomic_t workers_pending;
159 spinlock_t list_lock;
160 wait_queue_head_t list_wait;
161 u16 csum_size;
162 struct list_head csum_list;
163 atomic_t cancel_req;
164 int readonly;
165 int pages_per_rd_bio;
166
167 int is_dev_replace;
168
169 struct scrub_bio *wr_curr_bio;
170 struct mutex wr_lock;
171 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
172 struct btrfs_device *wr_tgtdev;
173 bool flush_all_writes;
174
175 /*
176 * statistics
177 */
178 struct btrfs_scrub_progress stat;
179 spinlock_t stat_lock;
180
181 /*
182 * Use a ref counter to avoid use-after-free issues. Scrub workers
183 * decrement bios_in_flight and workers_pending and then do a wakeup
184 * on the list_wait wait queue. We must ensure the main scrub task
185 * doesn't free the scrub context before or while the workers are
186 * doing the wakeup() call.
187 */
188 refcount_t refs;
189};
190
191struct scrub_fixup_nodatasum {
192 struct scrub_ctx *sctx;
193 struct btrfs_device *dev;
194 u64 logical;
195 struct btrfs_root *root;
196 struct btrfs_work work;
197 int mirror_num;
198};
199
200struct scrub_nocow_inode {
201 u64 inum;
202 u64 offset;
203 u64 root;
204 struct list_head list;
205};
206
207struct scrub_copy_nocow_ctx {
208 struct scrub_ctx *sctx;
209 u64 logical;
210 u64 len;
211 int mirror_num;
212 u64 physical_for_dev_replace;
213 struct list_head inodes;
214 struct btrfs_work work;
215};
216
217struct scrub_warning {
218 struct btrfs_path *path;
219 u64 extent_item_size;
220 const char *errstr;
221 u64 physical;
222 u64 logical;
223 struct btrfs_device *dev;
224};
225
226struct full_stripe_lock {
227 struct rb_node node;
228 u64 logical;
229 u64 refs;
230 struct mutex mutex;
231};
232
233static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
234static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
235static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
236static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
237static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
238static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
239 struct scrub_block *sblocks_for_recheck);
240static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
241 struct scrub_block *sblock,
242 int retry_failed_mirror);
243static void scrub_recheck_block_checksum(struct scrub_block *sblock);
244static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
245 struct scrub_block *sblock_good);
246static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
247 struct scrub_block *sblock_good,
248 int page_num, int force_write);
249static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
250static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
251 int page_num);
252static int scrub_checksum_data(struct scrub_block *sblock);
253static int scrub_checksum_tree_block(struct scrub_block *sblock);
254static int scrub_checksum_super(struct scrub_block *sblock);
255static void scrub_block_get(struct scrub_block *sblock);
256static void scrub_block_put(struct scrub_block *sblock);
257static void scrub_page_get(struct scrub_page *spage);
258static void scrub_page_put(struct scrub_page *spage);
259static void scrub_parity_get(struct scrub_parity *sparity);
260static void scrub_parity_put(struct scrub_parity *sparity);
261static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
262 struct scrub_page *spage);
263static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
264 u64 physical, struct btrfs_device *dev, u64 flags,
265 u64 gen, int mirror_num, u8 *csum, int force,
266 u64 physical_for_dev_replace);
267static void scrub_bio_end_io(struct bio *bio);
268static void scrub_bio_end_io_worker(struct btrfs_work *work);
269static void scrub_block_complete(struct scrub_block *sblock);
270static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
271 u64 extent_logical, u64 extent_len,
272 u64 *extent_physical,
273 struct btrfs_device **extent_dev,
274 int *extent_mirror_num);
275static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
276 struct scrub_page *spage);
277static void scrub_wr_submit(struct scrub_ctx *sctx);
278static void scrub_wr_bio_end_io(struct bio *bio);
279static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
280static int write_page_nocow(struct scrub_ctx *sctx,
281 u64 physical_for_dev_replace, struct page *page);
282static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
283 struct scrub_copy_nocow_ctx *ctx);
284static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
285 int mirror_num, u64 physical_for_dev_replace);
286static void copy_nocow_pages_worker(struct btrfs_work *work);
287static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
288static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
289static void scrub_put_ctx(struct scrub_ctx *sctx);
290
291static inline int scrub_is_page_on_raid56(struct scrub_page *page)
292{
293 return page->recover &&
294 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
295}
296
297static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
298{
299 refcount_inc(&sctx->refs);
300 atomic_inc(&sctx->bios_in_flight);
301}
302
303static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
304{
305 atomic_dec(&sctx->bios_in_flight);
306 wake_up(&sctx->list_wait);
307 scrub_put_ctx(sctx);
308}
309
310static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
311{
312 while (atomic_read(&fs_info->scrub_pause_req)) {
313 mutex_unlock(&fs_info->scrub_lock);
314 wait_event(fs_info->scrub_pause_wait,
315 atomic_read(&fs_info->scrub_pause_req) == 0);
316 mutex_lock(&fs_info->scrub_lock);
317 }
318}
319
320static void scrub_pause_on(struct btrfs_fs_info *fs_info)
321{
322 atomic_inc(&fs_info->scrubs_paused);
323 wake_up(&fs_info->scrub_pause_wait);
324}
325
326static void scrub_pause_off(struct btrfs_fs_info *fs_info)
327{
328 mutex_lock(&fs_info->scrub_lock);
329 __scrub_blocked_if_needed(fs_info);
330 atomic_dec(&fs_info->scrubs_paused);
331 mutex_unlock(&fs_info->scrub_lock);
332
333 wake_up(&fs_info->scrub_pause_wait);
334}
335
336static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
337{
338 scrub_pause_on(fs_info);
339 scrub_pause_off(fs_info);
340}
341
342/*
343 * Insert new full stripe lock into full stripe locks tree
344 *
345 * Return pointer to existing or newly inserted full_stripe_lock structure if
346 * everything works well.
347 * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
348 *
349 * NOTE: caller must hold full_stripe_locks_root->lock before calling this
350 * function
351 */
352static struct full_stripe_lock *insert_full_stripe_lock(
353 struct btrfs_full_stripe_locks_tree *locks_root,
354 u64 fstripe_logical)
355{
356 struct rb_node **p;
357 struct rb_node *parent = NULL;
358 struct full_stripe_lock *entry;
359 struct full_stripe_lock *ret;
360
361 lockdep_assert_held(&locks_root->lock);
362
363 p = &locks_root->root.rb_node;
364 while (*p) {
365 parent = *p;
366 entry = rb_entry(parent, struct full_stripe_lock, node);
367 if (fstripe_logical < entry->logical) {
368 p = &(*p)->rb_left;
369 } else if (fstripe_logical > entry->logical) {
370 p = &(*p)->rb_right;
371 } else {
372 entry->refs++;
373 return entry;
374 }
375 }
376
377 /* Insert new lock */
378 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
379 if (!ret)
380 return ERR_PTR(-ENOMEM);
381 ret->logical = fstripe_logical;
382 ret->refs = 1;
383 mutex_init(&ret->mutex);
384
385 rb_link_node(&ret->node, parent, p);
386 rb_insert_color(&ret->node, &locks_root->root);
387 return ret;
388}
389
390/*
391 * Search for a full stripe lock of a block group
392 *
393 * Return pointer to existing full stripe lock if found
394 * Return NULL if not found
395 */
396static struct full_stripe_lock *search_full_stripe_lock(
397 struct btrfs_full_stripe_locks_tree *locks_root,
398 u64 fstripe_logical)
399{
400 struct rb_node *node;
401 struct full_stripe_lock *entry;
402
403 lockdep_assert_held(&locks_root->lock);
404
405 node = locks_root->root.rb_node;
406 while (node) {
407 entry = rb_entry(node, struct full_stripe_lock, node);
408 if (fstripe_logical < entry->logical)
409 node = node->rb_left;
410 else if (fstripe_logical > entry->logical)
411 node = node->rb_right;
412 else
413 return entry;
414 }
415 return NULL;
416}
417
418/*
419 * Helper to get full stripe logical from a normal bytenr.
420 *
421 * Caller must ensure @cache is a RAID56 block group.
422 */
423static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
424 u64 bytenr)
425{
426 u64 ret;
427
428 /*
429 * Due to chunk item size limit, full stripe length should not be
430 * larger than U32_MAX. Just a sanity check here.
431 */
432 WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
433
434 /*
435 * round_down() can only handle power of 2, while RAID56 full
436 * stripe length can be 64KiB * n, so we need to manually round down.
437 */
438 ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
439 cache->full_stripe_len + cache->key.objectid;
440 return ret;
441}
442
443/*
444 * Lock a full stripe to avoid concurrency of recovery and read
445 *
446 * It's only used for profiles with parities (RAID5/6), for other profiles it
447 * does nothing.
448 *
449 * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
450 * So caller must call unlock_full_stripe() at the same context.
451 *
452 * Return <0 if encounters error.
453 */
454static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
455 bool *locked_ret)
456{
457 struct btrfs_block_group_cache *bg_cache;
458 struct btrfs_full_stripe_locks_tree *locks_root;
459 struct full_stripe_lock *existing;
460 u64 fstripe_start;
461 int ret = 0;
462
463 *locked_ret = false;
464 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
465 if (!bg_cache) {
466 ASSERT(0);
467 return -ENOENT;
468 }
469
470 /* Profiles not based on parity don't need full stripe lock */
471 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
472 goto out;
473 locks_root = &bg_cache->full_stripe_locks_root;
474
475 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
476
477 /* Now insert the full stripe lock */
478 mutex_lock(&locks_root->lock);
479 existing = insert_full_stripe_lock(locks_root, fstripe_start);
480 mutex_unlock(&locks_root->lock);
481 if (IS_ERR(existing)) {
482 ret = PTR_ERR(existing);
483 goto out;
484 }
485 mutex_lock(&existing->mutex);
486 *locked_ret = true;
487out:
488 btrfs_put_block_group(bg_cache);
489 return ret;
490}
491
492/*
493 * Unlock a full stripe.
494 *
495 * NOTE: Caller must ensure it's the same context calling corresponding
496 * lock_full_stripe().
497 *
498 * Return 0 if we unlock full stripe without problem.
499 * Return <0 for error
500 */
501static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
502 bool locked)
503{
504 struct btrfs_block_group_cache *bg_cache;
505 struct btrfs_full_stripe_locks_tree *locks_root;
506 struct full_stripe_lock *fstripe_lock;
507 u64 fstripe_start;
508 bool freeit = false;
509 int ret = 0;
510
511 /* If we didn't acquire full stripe lock, no need to continue */
512 if (!locked)
513 return 0;
514
515 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
516 if (!bg_cache) {
517 ASSERT(0);
518 return -ENOENT;
519 }
520 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
521 goto out;
522
523 locks_root = &bg_cache->full_stripe_locks_root;
524 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
525
526 mutex_lock(&locks_root->lock);
527 fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
528 /* Unpaired unlock_full_stripe() detected */
529 if (!fstripe_lock) {
530 WARN_ON(1);
531 ret = -ENOENT;
532 mutex_unlock(&locks_root->lock);
533 goto out;
534 }
535
536 if (fstripe_lock->refs == 0) {
537 WARN_ON(1);
538 btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
539 fstripe_lock->logical);
540 } else {
541 fstripe_lock->refs--;
542 }
543
544 if (fstripe_lock->refs == 0) {
545 rb_erase(&fstripe_lock->node, &locks_root->root);
546 freeit = true;
547 }
548 mutex_unlock(&locks_root->lock);
549
550 mutex_unlock(&fstripe_lock->mutex);
551 if (freeit)
552 kfree(fstripe_lock);
553out:
554 btrfs_put_block_group(bg_cache);
555 return ret;
556}
557
558/*
559 * used for workers that require transaction commits (i.e., for the
560 * NOCOW case)
561 */
562static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
563{
564 struct btrfs_fs_info *fs_info = sctx->fs_info;
565
566 refcount_inc(&sctx->refs);
567 /*
568 * increment scrubs_running to prevent cancel requests from
569 * completing as long as a worker is running. we must also
570 * increment scrubs_paused to prevent deadlocking on pause
571 * requests used for transactions commits (as the worker uses a
572 * transaction context). it is safe to regard the worker
573 * as paused for all matters practical. effectively, we only
574 * avoid cancellation requests from completing.
575 */
576 mutex_lock(&fs_info->scrub_lock);
577 atomic_inc(&fs_info->scrubs_running);
578 atomic_inc(&fs_info->scrubs_paused);
579 mutex_unlock(&fs_info->scrub_lock);
580
581 /*
582 * check if @scrubs_running=@scrubs_paused condition
583 * inside wait_event() is not an atomic operation.
584 * which means we may inc/dec @scrub_running/paused
585 * at any time. Let's wake up @scrub_pause_wait as
586 * much as we can to let commit transaction blocked less.
587 */
588 wake_up(&fs_info->scrub_pause_wait);
589
590 atomic_inc(&sctx->workers_pending);
591}
592
593/* used for workers that require transaction commits */
594static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
595{
596 struct btrfs_fs_info *fs_info = sctx->fs_info;
597
598 /*
599 * see scrub_pending_trans_workers_inc() why we're pretending
600 * to be paused in the scrub counters
601 */
602 mutex_lock(&fs_info->scrub_lock);
603 atomic_dec(&fs_info->scrubs_running);
604 atomic_dec(&fs_info->scrubs_paused);
605 mutex_unlock(&fs_info->scrub_lock);
606 atomic_dec(&sctx->workers_pending);
607 wake_up(&fs_info->scrub_pause_wait);
608 wake_up(&sctx->list_wait);
609 scrub_put_ctx(sctx);
610}
611
612static void scrub_free_csums(struct scrub_ctx *sctx)
613{
614 while (!list_empty(&sctx->csum_list)) {
615 struct btrfs_ordered_sum *sum;
616 sum = list_first_entry(&sctx->csum_list,
617 struct btrfs_ordered_sum, list);
618 list_del(&sum->list);
619 kfree(sum);
620 }
621}
622
623static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
624{
625 int i;
626
627 if (!sctx)
628 return;
629
630 /* this can happen when scrub is cancelled */
631 if (sctx->curr != -1) {
632 struct scrub_bio *sbio = sctx->bios[sctx->curr];
633
634 for (i = 0; i < sbio->page_count; i++) {
635 WARN_ON(!sbio->pagev[i]->page);
636 scrub_block_put(sbio->pagev[i]->sblock);
637 }
638 bio_put(sbio->bio);
639 }
640
641 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
642 struct scrub_bio *sbio = sctx->bios[i];
643
644 if (!sbio)
645 break;
646 kfree(sbio);
647 }
648
649 kfree(sctx->wr_curr_bio);
650 scrub_free_csums(sctx);
651 kfree(sctx);
652}
653
654static void scrub_put_ctx(struct scrub_ctx *sctx)
655{
656 if (refcount_dec_and_test(&sctx->refs))
657 scrub_free_ctx(sctx);
658}
659
660static noinline_for_stack
661struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
662{
663 struct scrub_ctx *sctx;
664 int i;
665 struct btrfs_fs_info *fs_info = dev->fs_info;
666
667 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
668 if (!sctx)
669 goto nomem;
670 refcount_set(&sctx->refs, 1);
671 sctx->is_dev_replace = is_dev_replace;
672 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
673 sctx->curr = -1;
674 sctx->fs_info = dev->fs_info;
675 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
676 struct scrub_bio *sbio;
677
678 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
679 if (!sbio)
680 goto nomem;
681 sctx->bios[i] = sbio;
682
683 sbio->index = i;
684 sbio->sctx = sctx;
685 sbio->page_count = 0;
686 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
687 scrub_bio_end_io_worker, NULL, NULL);
688
689 if (i != SCRUB_BIOS_PER_SCTX - 1)
690 sctx->bios[i]->next_free = i + 1;
691 else
692 sctx->bios[i]->next_free = -1;
693 }
694 sctx->first_free = 0;
695 atomic_set(&sctx->bios_in_flight, 0);
696 atomic_set(&sctx->workers_pending, 0);
697 atomic_set(&sctx->cancel_req, 0);
698 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
699 INIT_LIST_HEAD(&sctx->csum_list);
700
701 spin_lock_init(&sctx->list_lock);
702 spin_lock_init(&sctx->stat_lock);
703 init_waitqueue_head(&sctx->list_wait);
704
705 WARN_ON(sctx->wr_curr_bio != NULL);
706 mutex_init(&sctx->wr_lock);
707 sctx->wr_curr_bio = NULL;
708 if (is_dev_replace) {
709 WARN_ON(!fs_info->dev_replace.tgtdev);
710 sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
711 sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
712 sctx->flush_all_writes = false;
713 }
714
715 return sctx;
716
717nomem:
718 scrub_free_ctx(sctx);
719 return ERR_PTR(-ENOMEM);
720}
721
722static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
723 void *warn_ctx)
724{
725 u64 isize;
726 u32 nlink;
727 int ret;
728 int i;
729 unsigned nofs_flag;
730 struct extent_buffer *eb;
731 struct btrfs_inode_item *inode_item;
732 struct scrub_warning *swarn = warn_ctx;
733 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
734 struct inode_fs_paths *ipath = NULL;
735 struct btrfs_root *local_root;
736 struct btrfs_key root_key;
737 struct btrfs_key key;
738
739 root_key.objectid = root;
740 root_key.type = BTRFS_ROOT_ITEM_KEY;
741 root_key.offset = (u64)-1;
742 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
743 if (IS_ERR(local_root)) {
744 ret = PTR_ERR(local_root);
745 goto err;
746 }
747
748 /*
749 * this makes the path point to (inum INODE_ITEM ioff)
750 */
751 key.objectid = inum;
752 key.type = BTRFS_INODE_ITEM_KEY;
753 key.offset = 0;
754
755 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
756 if (ret) {
757 btrfs_release_path(swarn->path);
758 goto err;
759 }
760
761 eb = swarn->path->nodes[0];
762 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
763 struct btrfs_inode_item);
764 isize = btrfs_inode_size(eb, inode_item);
765 nlink = btrfs_inode_nlink(eb, inode_item);
766 btrfs_release_path(swarn->path);
767
768 /*
769 * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
770 * uses GFP_NOFS in this context, so we keep it consistent but it does
771 * not seem to be strictly necessary.
772 */
773 nofs_flag = memalloc_nofs_save();
774 ipath = init_ipath(4096, local_root, swarn->path);
775 memalloc_nofs_restore(nofs_flag);
776 if (IS_ERR(ipath)) {
777 ret = PTR_ERR(ipath);
778 ipath = NULL;
779 goto err;
780 }
781 ret = paths_from_inode(inum, ipath);
782
783 if (ret < 0)
784 goto err;
785
786 /*
787 * we deliberately ignore the bit ipath might have been too small to
788 * hold all of the paths here
789 */
790 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
791 btrfs_warn_in_rcu(fs_info,
792"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
793 swarn->errstr, swarn->logical,
794 rcu_str_deref(swarn->dev->name),
795 swarn->physical,
796 root, inum, offset,
797 min(isize - offset, (u64)PAGE_SIZE), nlink,
798 (char *)(unsigned long)ipath->fspath->val[i]);
799
800 free_ipath(ipath);
801 return 0;
802
803err:
804 btrfs_warn_in_rcu(fs_info,
805 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
806 swarn->errstr, swarn->logical,
807 rcu_str_deref(swarn->dev->name),
808 swarn->physical,
809 root, inum, offset, ret);
810
811 free_ipath(ipath);
812 return 0;
813}
814
815static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
816{
817 struct btrfs_device *dev;
818 struct btrfs_fs_info *fs_info;
819 struct btrfs_path *path;
820 struct btrfs_key found_key;
821 struct extent_buffer *eb;
822 struct btrfs_extent_item *ei;
823 struct scrub_warning swarn;
824 unsigned long ptr = 0;
825 u64 extent_item_pos;
826 u64 flags = 0;
827 u64 ref_root;
828 u32 item_size;
829 u8 ref_level = 0;
830 int ret;
831
832 WARN_ON(sblock->page_count < 1);
833 dev = sblock->pagev[0]->dev;
834 fs_info = sblock->sctx->fs_info;
835
836 path = btrfs_alloc_path();
837 if (!path)
838 return;
839
840 swarn.physical = sblock->pagev[0]->physical;
841 swarn.logical = sblock->pagev[0]->logical;
842 swarn.errstr = errstr;
843 swarn.dev = NULL;
844
845 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
846 &flags);
847 if (ret < 0)
848 goto out;
849
850 extent_item_pos = swarn.logical - found_key.objectid;
851 swarn.extent_item_size = found_key.offset;
852
853 eb = path->nodes[0];
854 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
855 item_size = btrfs_item_size_nr(eb, path->slots[0]);
856
857 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
858 do {
859 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
860 item_size, &ref_root,
861 &ref_level);
862 btrfs_warn_in_rcu(fs_info,
863"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
864 errstr, swarn.logical,
865 rcu_str_deref(dev->name),
866 swarn.physical,
867 ref_level ? "node" : "leaf",
868 ret < 0 ? -1 : ref_level,
869 ret < 0 ? -1 : ref_root);
870 } while (ret != 1);
871 btrfs_release_path(path);
872 } else {
873 btrfs_release_path(path);
874 swarn.path = path;
875 swarn.dev = dev;
876 iterate_extent_inodes(fs_info, found_key.objectid,
877 extent_item_pos, 1,
878 scrub_print_warning_inode, &swarn, false);
879 }
880
881out:
882 btrfs_free_path(path);
883}
884
885static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
886{
887 struct page *page = NULL;
888 unsigned long index;
889 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
890 int ret;
891 int corrected = 0;
892 struct btrfs_key key;
893 struct inode *inode = NULL;
894 struct btrfs_fs_info *fs_info;
895 u64 end = offset + PAGE_SIZE - 1;
896 struct btrfs_root *local_root;
897 int srcu_index;
898
899 key.objectid = root;
900 key.type = BTRFS_ROOT_ITEM_KEY;
901 key.offset = (u64)-1;
902
903 fs_info = fixup->root->fs_info;
904 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
905
906 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
907 if (IS_ERR(local_root)) {
908 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
909 return PTR_ERR(local_root);
910 }
911
912 key.type = BTRFS_INODE_ITEM_KEY;
913 key.objectid = inum;
914 key.offset = 0;
915 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
916 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
917 if (IS_ERR(inode))
918 return PTR_ERR(inode);
919
920 index = offset >> PAGE_SHIFT;
921
922 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
923 if (!page) {
924 ret = -ENOMEM;
925 goto out;
926 }
927
928 if (PageUptodate(page)) {
929 if (PageDirty(page)) {
930 /*
931 * we need to write the data to the defect sector. the
932 * data that was in that sector is not in memory,
933 * because the page was modified. we must not write the
934 * modified page to that sector.
935 *
936 * TODO: what could be done here: wait for the delalloc
937 * runner to write out that page (might involve
938 * COW) and see whether the sector is still
939 * referenced afterwards.
940 *
941 * For the meantime, we'll treat this error
942 * incorrectable, although there is a chance that a
943 * later scrub will find the bad sector again and that
944 * there's no dirty page in memory, then.
945 */
946 ret = -EIO;
947 goto out;
948 }
949 ret = repair_io_failure(fs_info, inum, offset, PAGE_SIZE,
950 fixup->logical, page,
951 offset - page_offset(page),
952 fixup->mirror_num);
953 unlock_page(page);
954 corrected = !ret;
955 } else {
956 /*
957 * we need to get good data first. the general readpage path
958 * will call repair_io_failure for us, we just have to make
959 * sure we read the bad mirror.
960 */
961 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
962 EXTENT_DAMAGED);
963 if (ret) {
964 /* set_extent_bits should give proper error */
965 WARN_ON(ret > 0);
966 if (ret > 0)
967 ret = -EFAULT;
968 goto out;
969 }
970
971 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
972 btrfs_get_extent,
973 fixup->mirror_num);
974 wait_on_page_locked(page);
975
976 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
977 end, EXTENT_DAMAGED, 0, NULL);
978 if (!corrected)
979 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
980 EXTENT_DAMAGED);
981 }
982
983out:
984 if (page)
985 put_page(page);
986
987 iput(inode);
988
989 if (ret < 0)
990 return ret;
991
992 if (ret == 0 && corrected) {
993 /*
994 * we only need to call readpage for one of the inodes belonging
995 * to this extent. so make iterate_extent_inodes stop
996 */
997 return 1;
998 }
999
1000 return -EIO;
1001}
1002
1003static void scrub_fixup_nodatasum(struct btrfs_work *work)
1004{
1005 struct btrfs_fs_info *fs_info;
1006 int ret;
1007 struct scrub_fixup_nodatasum *fixup;
1008 struct scrub_ctx *sctx;
1009 struct btrfs_trans_handle *trans = NULL;
1010 struct btrfs_path *path;
1011 int uncorrectable = 0;
1012
1013 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
1014 sctx = fixup->sctx;
1015 fs_info = fixup->root->fs_info;
1016
1017 path = btrfs_alloc_path();
1018 if (!path) {
1019 spin_lock(&sctx->stat_lock);
1020 ++sctx->stat.malloc_errors;
1021 spin_unlock(&sctx->stat_lock);
1022 uncorrectable = 1;
1023 goto out;
1024 }
1025
1026 trans = btrfs_join_transaction(fixup->root);
1027 if (IS_ERR(trans)) {
1028 uncorrectable = 1;
1029 goto out;
1030 }
1031
1032 /*
1033 * the idea is to trigger a regular read through the standard path. we
1034 * read a page from the (failed) logical address by specifying the
1035 * corresponding copynum of the failed sector. thus, that readpage is
1036 * expected to fail.
1037 * that is the point where on-the-fly error correction will kick in
1038 * (once it's finished) and rewrite the failed sector if a good copy
1039 * can be found.
1040 */
1041 ret = iterate_inodes_from_logical(fixup->logical, fs_info, path,
1042 scrub_fixup_readpage, fixup, false);
1043 if (ret < 0) {
1044 uncorrectable = 1;
1045 goto out;
1046 }
1047 WARN_ON(ret != 1);
1048
1049 spin_lock(&sctx->stat_lock);
1050 ++sctx->stat.corrected_errors;
1051 spin_unlock(&sctx->stat_lock);
1052
1053out:
1054 if (trans && !IS_ERR(trans))
1055 btrfs_end_transaction(trans);
1056 if (uncorrectable) {
1057 spin_lock(&sctx->stat_lock);
1058 ++sctx->stat.uncorrectable_errors;
1059 spin_unlock(&sctx->stat_lock);
1060 btrfs_dev_replace_stats_inc(
1061 &fs_info->dev_replace.num_uncorrectable_read_errors);
1062 btrfs_err_rl_in_rcu(fs_info,
1063 "unable to fixup (nodatasum) error at logical %llu on dev %s",
1064 fixup->logical, rcu_str_deref(fixup->dev->name));
1065 }
1066
1067 btrfs_free_path(path);
1068 kfree(fixup);
1069
1070 scrub_pending_trans_workers_dec(sctx);
1071}
1072
1073static inline void scrub_get_recover(struct scrub_recover *recover)
1074{
1075 refcount_inc(&recover->refs);
1076}
1077
1078static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
1079 struct scrub_recover *recover)
1080{
1081 if (refcount_dec_and_test(&recover->refs)) {
1082 btrfs_bio_counter_dec(fs_info);
1083 btrfs_put_bbio(recover->bbio);
1084 kfree(recover);
1085 }
1086}
1087
1088/*
1089 * scrub_handle_errored_block gets called when either verification of the
1090 * pages failed or the bio failed to read, e.g. with EIO. In the latter
1091 * case, this function handles all pages in the bio, even though only one
1092 * may be bad.
1093 * The goal of this function is to repair the errored block by using the
1094 * contents of one of the mirrors.
1095 */
1096static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
1097{
1098 struct scrub_ctx *sctx = sblock_to_check->sctx;
1099 struct btrfs_device *dev;
1100 struct btrfs_fs_info *fs_info;
1101 u64 logical;
1102 unsigned int failed_mirror_index;
1103 unsigned int is_metadata;
1104 unsigned int have_csum;
1105 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
1106 struct scrub_block *sblock_bad;
1107 int ret;
1108 int mirror_index;
1109 int page_num;
1110 int success;
1111 bool full_stripe_locked;
1112 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
1113 DEFAULT_RATELIMIT_BURST);
1114
1115 BUG_ON(sblock_to_check->page_count < 1);
1116 fs_info = sctx->fs_info;
1117 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
1118 /*
1119 * if we find an error in a super block, we just report it.
1120 * They will get written with the next transaction commit
1121 * anyway
1122 */
1123 spin_lock(&sctx->stat_lock);
1124 ++sctx->stat.super_errors;
1125 spin_unlock(&sctx->stat_lock);
1126 return 0;
1127 }
1128 logical = sblock_to_check->pagev[0]->logical;
1129 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
1130 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
1131 is_metadata = !(sblock_to_check->pagev[0]->flags &
1132 BTRFS_EXTENT_FLAG_DATA);
1133 have_csum = sblock_to_check->pagev[0]->have_csum;
1134 dev = sblock_to_check->pagev[0]->dev;
1135
1136 /*
1137 * For RAID5/6, race can happen for a different device scrub thread.
1138 * For data corruption, Parity and Data threads will both try
1139 * to recovery the data.
1140 * Race can lead to doubly added csum error, or even unrecoverable
1141 * error.
1142 */
1143 ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
1144 if (ret < 0) {
1145 spin_lock(&sctx->stat_lock);
1146 if (ret == -ENOMEM)
1147 sctx->stat.malloc_errors++;
1148 sctx->stat.read_errors++;
1149 sctx->stat.uncorrectable_errors++;
1150 spin_unlock(&sctx->stat_lock);
1151 return ret;
1152 }
1153
1154 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
1155 sblocks_for_recheck = NULL;
1156 goto nodatasum_case;
1157 }
1158
1159 /*
1160 * read all mirrors one after the other. This includes to
1161 * re-read the extent or metadata block that failed (that was
1162 * the cause that this fixup code is called) another time,
1163 * page by page this time in order to know which pages
1164 * caused I/O errors and which ones are good (for all mirrors).
1165 * It is the goal to handle the situation when more than one
1166 * mirror contains I/O errors, but the errors do not
1167 * overlap, i.e. the data can be repaired by selecting the
1168 * pages from those mirrors without I/O error on the
1169 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
1170 * would be that mirror #1 has an I/O error on the first page,
1171 * the second page is good, and mirror #2 has an I/O error on
1172 * the second page, but the first page is good.
1173 * Then the first page of the first mirror can be repaired by
1174 * taking the first page of the second mirror, and the
1175 * second page of the second mirror can be repaired by
1176 * copying the contents of the 2nd page of the 1st mirror.
1177 * One more note: if the pages of one mirror contain I/O
1178 * errors, the checksum cannot be verified. In order to get
1179 * the best data for repairing, the first attempt is to find
1180 * a mirror without I/O errors and with a validated checksum.
1181 * Only if this is not possible, the pages are picked from
1182 * mirrors with I/O errors without considering the checksum.
1183 * If the latter is the case, at the end, the checksum of the
1184 * repaired area is verified in order to correctly maintain
1185 * the statistics.
1186 */
1187
1188 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
1189 sizeof(*sblocks_for_recheck), GFP_NOFS);
1190 if (!sblocks_for_recheck) {
1191 spin_lock(&sctx->stat_lock);
1192 sctx->stat.malloc_errors++;
1193 sctx->stat.read_errors++;
1194 sctx->stat.uncorrectable_errors++;
1195 spin_unlock(&sctx->stat_lock);
1196 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1197 goto out;
1198 }
1199
1200 /* setup the context, map the logical blocks and alloc the pages */
1201 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
1202 if (ret) {
1203 spin_lock(&sctx->stat_lock);
1204 sctx->stat.read_errors++;
1205 sctx->stat.uncorrectable_errors++;
1206 spin_unlock(&sctx->stat_lock);
1207 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1208 goto out;
1209 }
1210 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
1211 sblock_bad = sblocks_for_recheck + failed_mirror_index;
1212
1213 /* build and submit the bios for the failed mirror, check checksums */
1214 scrub_recheck_block(fs_info, sblock_bad, 1);
1215
1216 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
1217 sblock_bad->no_io_error_seen) {
1218 /*
1219 * the error disappeared after reading page by page, or
1220 * the area was part of a huge bio and other parts of the
1221 * bio caused I/O errors, or the block layer merged several
1222 * read requests into one and the error is caused by a
1223 * different bio (usually one of the two latter cases is
1224 * the cause)
1225 */
1226 spin_lock(&sctx->stat_lock);
1227 sctx->stat.unverified_errors++;
1228 sblock_to_check->data_corrected = 1;
1229 spin_unlock(&sctx->stat_lock);
1230
1231 if (sctx->is_dev_replace)
1232 scrub_write_block_to_dev_replace(sblock_bad);
1233 goto out;
1234 }
1235
1236 if (!sblock_bad->no_io_error_seen) {
1237 spin_lock(&sctx->stat_lock);
1238 sctx->stat.read_errors++;
1239 spin_unlock(&sctx->stat_lock);
1240 if (__ratelimit(&_rs))
1241 scrub_print_warning("i/o error", sblock_to_check);
1242 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1243 } else if (sblock_bad->checksum_error) {
1244 spin_lock(&sctx->stat_lock);
1245 sctx->stat.csum_errors++;
1246 spin_unlock(&sctx->stat_lock);
1247 if (__ratelimit(&_rs))
1248 scrub_print_warning("checksum error", sblock_to_check);
1249 btrfs_dev_stat_inc_and_print(dev,
1250 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1251 } else if (sblock_bad->header_error) {
1252 spin_lock(&sctx->stat_lock);
1253 sctx->stat.verify_errors++;
1254 spin_unlock(&sctx->stat_lock);
1255 if (__ratelimit(&_rs))
1256 scrub_print_warning("checksum/header error",
1257 sblock_to_check);
1258 if (sblock_bad->generation_error)
1259 btrfs_dev_stat_inc_and_print(dev,
1260 BTRFS_DEV_STAT_GENERATION_ERRS);
1261 else
1262 btrfs_dev_stat_inc_and_print(dev,
1263 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1264 }
1265
1266 if (sctx->readonly) {
1267 ASSERT(!sctx->is_dev_replace);
1268 goto out;
1269 }
1270
1271 if (!is_metadata && !have_csum) {
1272 struct scrub_fixup_nodatasum *fixup_nodatasum;
1273
1274 WARN_ON(sctx->is_dev_replace);
1275
1276nodatasum_case:
1277
1278 /*
1279 * !is_metadata and !have_csum, this means that the data
1280 * might not be COWed, that it might be modified
1281 * concurrently. The general strategy to work on the
1282 * commit root does not help in the case when COW is not
1283 * used.
1284 */
1285 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
1286 if (!fixup_nodatasum)
1287 goto did_not_correct_error;
1288 fixup_nodatasum->sctx = sctx;
1289 fixup_nodatasum->dev = dev;
1290 fixup_nodatasum->logical = logical;
1291 fixup_nodatasum->root = fs_info->extent_root;
1292 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1293 scrub_pending_trans_workers_inc(sctx);
1294 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
1295 scrub_fixup_nodatasum, NULL, NULL);
1296 btrfs_queue_work(fs_info->scrub_workers,
1297 &fixup_nodatasum->work);
1298 goto out;
1299 }
1300
1301 /*
1302 * now build and submit the bios for the other mirrors, check
1303 * checksums.
1304 * First try to pick the mirror which is completely without I/O
1305 * errors and also does not have a checksum error.
1306 * If one is found, and if a checksum is present, the full block
1307 * that is known to contain an error is rewritten. Afterwards
1308 * the block is known to be corrected.
1309 * If a mirror is found which is completely correct, and no
1310 * checksum is present, only those pages are rewritten that had
1311 * an I/O error in the block to be repaired, since it cannot be
1312 * determined, which copy of the other pages is better (and it
1313 * could happen otherwise that a correct page would be
1314 * overwritten by a bad one).
1315 */
1316 for (mirror_index = 0; ;mirror_index++) {
1317 struct scrub_block *sblock_other;
1318
1319 if (mirror_index == failed_mirror_index)
1320 continue;
1321
1322 /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
1323 if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1324 if (mirror_index >= BTRFS_MAX_MIRRORS)
1325 break;
1326 if (!sblocks_for_recheck[mirror_index].page_count)
1327 break;
1328
1329 sblock_other = sblocks_for_recheck + mirror_index;
1330 } else {
1331 struct scrub_recover *r = sblock_bad->pagev[0]->recover;
1332 int max_allowed = r->bbio->num_stripes -
1333 r->bbio->num_tgtdevs;
1334
1335 if (mirror_index >= max_allowed)
1336 break;
1337 if (!sblocks_for_recheck[1].page_count)
1338 break;
1339
1340 ASSERT(failed_mirror_index == 0);
1341 sblock_other = sblocks_for_recheck + 1;
1342 sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
1343 }
1344
1345 /* build and submit the bios, check checksums */
1346 scrub_recheck_block(fs_info, sblock_other, 0);
1347
1348 if (!sblock_other->header_error &&
1349 !sblock_other->checksum_error &&
1350 sblock_other->no_io_error_seen) {
1351 if (sctx->is_dev_replace) {
1352 scrub_write_block_to_dev_replace(sblock_other);
1353 goto corrected_error;
1354 } else {
1355 ret = scrub_repair_block_from_good_copy(
1356 sblock_bad, sblock_other);
1357 if (!ret)
1358 goto corrected_error;
1359 }
1360 }
1361 }
1362
1363 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1364 goto did_not_correct_error;
1365
1366 /*
1367 * In case of I/O errors in the area that is supposed to be
1368 * repaired, continue by picking good copies of those pages.
1369 * Select the good pages from mirrors to rewrite bad pages from
1370 * the area to fix. Afterwards verify the checksum of the block
1371 * that is supposed to be repaired. This verification step is
1372 * only done for the purpose of statistic counting and for the
1373 * final scrub report, whether errors remain.
1374 * A perfect algorithm could make use of the checksum and try
1375 * all possible combinations of pages from the different mirrors
1376 * until the checksum verification succeeds. For example, when
1377 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1378 * of mirror #2 is readable but the final checksum test fails,
1379 * then the 2nd page of mirror #3 could be tried, whether now
1380 * the final checksum succeeds. But this would be a rare
1381 * exception and is therefore not implemented. At least it is
1382 * avoided that the good copy is overwritten.
1383 * A more useful improvement would be to pick the sectors
1384 * without I/O error based on sector sizes (512 bytes on legacy
1385 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1386 * mirror could be repaired by taking 512 byte of a different
1387 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1388 * area are unreadable.
1389 */
1390 success = 1;
1391 for (page_num = 0; page_num < sblock_bad->page_count;
1392 page_num++) {
1393 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1394 struct scrub_block *sblock_other = NULL;
1395
1396 /* skip no-io-error page in scrub */
1397 if (!page_bad->io_error && !sctx->is_dev_replace)
1398 continue;
1399
1400 if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1401 /*
1402 * In case of dev replace, if raid56 rebuild process
1403 * didn't work out correct data, then copy the content
1404 * in sblock_bad to make sure target device is identical
1405 * to source device, instead of writing garbage data in
1406 * sblock_for_recheck array to target device.
1407 */
1408 sblock_other = NULL;
1409 } else if (page_bad->io_error) {
1410 /* try to find no-io-error page in mirrors */
1411 for (mirror_index = 0;
1412 mirror_index < BTRFS_MAX_MIRRORS &&
1413 sblocks_for_recheck[mirror_index].page_count > 0;
1414 mirror_index++) {
1415 if (!sblocks_for_recheck[mirror_index].
1416 pagev[page_num]->io_error) {
1417 sblock_other = sblocks_for_recheck +
1418 mirror_index;
1419 break;
1420 }
1421 }
1422 if (!sblock_other)
1423 success = 0;
1424 }
1425
1426 if (sctx->is_dev_replace) {
1427 /*
1428 * did not find a mirror to fetch the page
1429 * from. scrub_write_page_to_dev_replace()
1430 * handles this case (page->io_error), by
1431 * filling the block with zeros before
1432 * submitting the write request
1433 */
1434 if (!sblock_other)
1435 sblock_other = sblock_bad;
1436
1437 if (scrub_write_page_to_dev_replace(sblock_other,
1438 page_num) != 0) {
1439 btrfs_dev_replace_stats_inc(
1440 &fs_info->dev_replace.num_write_errors);
1441 success = 0;
1442 }
1443 } else if (sblock_other) {
1444 ret = scrub_repair_page_from_good_copy(sblock_bad,
1445 sblock_other,
1446 page_num, 0);
1447 if (0 == ret)
1448 page_bad->io_error = 0;
1449 else
1450 success = 0;
1451 }
1452 }
1453
1454 if (success && !sctx->is_dev_replace) {
1455 if (is_metadata || have_csum) {
1456 /*
1457 * need to verify the checksum now that all
1458 * sectors on disk are repaired (the write
1459 * request for data to be repaired is on its way).
1460 * Just be lazy and use scrub_recheck_block()
1461 * which re-reads the data before the checksum
1462 * is verified, but most likely the data comes out
1463 * of the page cache.
1464 */
1465 scrub_recheck_block(fs_info, sblock_bad, 1);
1466 if (!sblock_bad->header_error &&
1467 !sblock_bad->checksum_error &&
1468 sblock_bad->no_io_error_seen)
1469 goto corrected_error;
1470 else
1471 goto did_not_correct_error;
1472 } else {
1473corrected_error:
1474 spin_lock(&sctx->stat_lock);
1475 sctx->stat.corrected_errors++;
1476 sblock_to_check->data_corrected = 1;
1477 spin_unlock(&sctx->stat_lock);
1478 btrfs_err_rl_in_rcu(fs_info,
1479 "fixed up error at logical %llu on dev %s",
1480 logical, rcu_str_deref(dev->name));
1481 }
1482 } else {
1483did_not_correct_error:
1484 spin_lock(&sctx->stat_lock);
1485 sctx->stat.uncorrectable_errors++;
1486 spin_unlock(&sctx->stat_lock);
1487 btrfs_err_rl_in_rcu(fs_info,
1488 "unable to fixup (regular) error at logical %llu on dev %s",
1489 logical, rcu_str_deref(dev->name));
1490 }
1491
1492out:
1493 if (sblocks_for_recheck) {
1494 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1495 mirror_index++) {
1496 struct scrub_block *sblock = sblocks_for_recheck +
1497 mirror_index;
1498 struct scrub_recover *recover;
1499 int page_index;
1500
1501 for (page_index = 0; page_index < sblock->page_count;
1502 page_index++) {
1503 sblock->pagev[page_index]->sblock = NULL;
1504 recover = sblock->pagev[page_index]->recover;
1505 if (recover) {
1506 scrub_put_recover(fs_info, recover);
1507 sblock->pagev[page_index]->recover =
1508 NULL;
1509 }
1510 scrub_page_put(sblock->pagev[page_index]);
1511 }
1512 }
1513 kfree(sblocks_for_recheck);
1514 }
1515
1516 ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
1517 if (ret < 0)
1518 return ret;
1519 return 0;
1520}
1521
1522static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1523{
1524 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1525 return 2;
1526 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1527 return 3;
1528 else
1529 return (int)bbio->num_stripes;
1530}
1531
1532static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1533 u64 *raid_map,
1534 u64 mapped_length,
1535 int nstripes, int mirror,
1536 int *stripe_index,
1537 u64 *stripe_offset)
1538{
1539 int i;
1540
1541 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1542 /* RAID5/6 */
1543 for (i = 0; i < nstripes; i++) {
1544 if (raid_map[i] == RAID6_Q_STRIPE ||
1545 raid_map[i] == RAID5_P_STRIPE)
1546 continue;
1547
1548 if (logical >= raid_map[i] &&
1549 logical < raid_map[i] + mapped_length)
1550 break;
1551 }
1552
1553 *stripe_index = i;
1554 *stripe_offset = logical - raid_map[i];
1555 } else {
1556 /* The other RAID type */
1557 *stripe_index = mirror;
1558 *stripe_offset = 0;
1559 }
1560}
1561
1562static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1563 struct scrub_block *sblocks_for_recheck)
1564{
1565 struct scrub_ctx *sctx = original_sblock->sctx;
1566 struct btrfs_fs_info *fs_info = sctx->fs_info;
1567 u64 length = original_sblock->page_count * PAGE_SIZE;
1568 u64 logical = original_sblock->pagev[0]->logical;
1569 u64 generation = original_sblock->pagev[0]->generation;
1570 u64 flags = original_sblock->pagev[0]->flags;
1571 u64 have_csum = original_sblock->pagev[0]->have_csum;
1572 struct scrub_recover *recover;
1573 struct btrfs_bio *bbio;
1574 u64 sublen;
1575 u64 mapped_length;
1576 u64 stripe_offset;
1577 int stripe_index;
1578 int page_index = 0;
1579 int mirror_index;
1580 int nmirrors;
1581 int ret;
1582
1583 /*
1584 * note: the two members refs and outstanding_pages
1585 * are not used (and not set) in the blocks that are used for
1586 * the recheck procedure
1587 */
1588
1589 while (length > 0) {
1590 sublen = min_t(u64, length, PAGE_SIZE);
1591 mapped_length = sublen;
1592 bbio = NULL;
1593
1594 /*
1595 * with a length of PAGE_SIZE, each returned stripe
1596 * represents one mirror
1597 */
1598 btrfs_bio_counter_inc_blocked(fs_info);
1599 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1600 logical, &mapped_length, &bbio);
1601 if (ret || !bbio || mapped_length < sublen) {
1602 btrfs_put_bbio(bbio);
1603 btrfs_bio_counter_dec(fs_info);
1604 return -EIO;
1605 }
1606
1607 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1608 if (!recover) {
1609 btrfs_put_bbio(bbio);
1610 btrfs_bio_counter_dec(fs_info);
1611 return -ENOMEM;
1612 }
1613
1614 refcount_set(&recover->refs, 1);
1615 recover->bbio = bbio;
1616 recover->map_length = mapped_length;
1617
1618 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1619
1620 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1621
1622 for (mirror_index = 0; mirror_index < nmirrors;
1623 mirror_index++) {
1624 struct scrub_block *sblock;
1625 struct scrub_page *page;
1626
1627 sblock = sblocks_for_recheck + mirror_index;
1628 sblock->sctx = sctx;
1629
1630 page = kzalloc(sizeof(*page), GFP_NOFS);
1631 if (!page) {
1632leave_nomem:
1633 spin_lock(&sctx->stat_lock);
1634 sctx->stat.malloc_errors++;
1635 spin_unlock(&sctx->stat_lock);
1636 scrub_put_recover(fs_info, recover);
1637 return -ENOMEM;
1638 }
1639 scrub_page_get(page);
1640 sblock->pagev[page_index] = page;
1641 page->sblock = sblock;
1642 page->flags = flags;
1643 page->generation = generation;
1644 page->logical = logical;
1645 page->have_csum = have_csum;
1646 if (have_csum)
1647 memcpy(page->csum,
1648 original_sblock->pagev[0]->csum,
1649 sctx->csum_size);
1650
1651 scrub_stripe_index_and_offset(logical,
1652 bbio->map_type,
1653 bbio->raid_map,
1654 mapped_length,
1655 bbio->num_stripes -
1656 bbio->num_tgtdevs,
1657 mirror_index,
1658 &stripe_index,
1659 &stripe_offset);
1660 page->physical = bbio->stripes[stripe_index].physical +
1661 stripe_offset;
1662 page->dev = bbio->stripes[stripe_index].dev;
1663
1664 BUG_ON(page_index >= original_sblock->page_count);
1665 page->physical_for_dev_replace =
1666 original_sblock->pagev[page_index]->
1667 physical_for_dev_replace;
1668 /* for missing devices, dev->bdev is NULL */
1669 page->mirror_num = mirror_index + 1;
1670 sblock->page_count++;
1671 page->page = alloc_page(GFP_NOFS);
1672 if (!page->page)
1673 goto leave_nomem;
1674
1675 scrub_get_recover(recover);
1676 page->recover = recover;
1677 }
1678 scrub_put_recover(fs_info, recover);
1679 length -= sublen;
1680 logical += sublen;
1681 page_index++;
1682 }
1683
1684 return 0;
1685}
1686
1687static void scrub_bio_wait_endio(struct bio *bio)
1688{
1689 complete(bio->bi_private);
1690}
1691
1692static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1693 struct bio *bio,
1694 struct scrub_page *page)
1695{
1696 DECLARE_COMPLETION_ONSTACK(done);
1697 int ret;
1698 int mirror_num;
1699
1700 bio->bi_iter.bi_sector = page->logical >> 9;
1701 bio->bi_private = &done;
1702 bio->bi_end_io = scrub_bio_wait_endio;
1703
1704 mirror_num = page->sblock->pagev[0]->mirror_num;
1705 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1706 page->recover->map_length,
1707 mirror_num, 0);
1708 if (ret)
1709 return ret;
1710
1711 wait_for_completion_io(&done);
1712 return blk_status_to_errno(bio->bi_status);
1713}
1714
1715static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
1716 struct scrub_block *sblock)
1717{
1718 struct scrub_page *first_page = sblock->pagev[0];
1719 struct bio *bio;
1720 int page_num;
1721
1722 /* All pages in sblock belong to the same stripe on the same device. */
1723 ASSERT(first_page->dev);
1724 if (!first_page->dev->bdev)
1725 goto out;
1726
1727 bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
1728 bio_set_dev(bio, first_page->dev->bdev);
1729
1730 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1731 struct scrub_page *page = sblock->pagev[page_num];
1732
1733 WARN_ON(!page->page);
1734 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1735 }
1736
1737 if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
1738 bio_put(bio);
1739 goto out;
1740 }
1741
1742 bio_put(bio);
1743
1744 scrub_recheck_block_checksum(sblock);
1745
1746 return;
1747out:
1748 for (page_num = 0; page_num < sblock->page_count; page_num++)
1749 sblock->pagev[page_num]->io_error = 1;
1750
1751 sblock->no_io_error_seen = 0;
1752}
1753
1754/*
1755 * this function will check the on disk data for checksum errors, header
1756 * errors and read I/O errors. If any I/O errors happen, the exact pages
1757 * which are errored are marked as being bad. The goal is to enable scrub
1758 * to take those pages that are not errored from all the mirrors so that
1759 * the pages that are errored in the just handled mirror can be repaired.
1760 */
1761static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1762 struct scrub_block *sblock,
1763 int retry_failed_mirror)
1764{
1765 int page_num;
1766
1767 sblock->no_io_error_seen = 1;
1768
1769 /* short cut for raid56 */
1770 if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
1771 return scrub_recheck_block_on_raid56(fs_info, sblock);
1772
1773 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1774 struct bio *bio;
1775 struct scrub_page *page = sblock->pagev[page_num];
1776
1777 if (page->dev->bdev == NULL) {
1778 page->io_error = 1;
1779 sblock->no_io_error_seen = 0;
1780 continue;
1781 }
1782
1783 WARN_ON(!page->page);
1784 bio = btrfs_io_bio_alloc(1);
1785 bio_set_dev(bio, page->dev->bdev);
1786
1787 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1788 bio->bi_iter.bi_sector = page->physical >> 9;
1789 bio->bi_opf = REQ_OP_READ;
1790
1791 if (btrfsic_submit_bio_wait(bio)) {
1792 page->io_error = 1;
1793 sblock->no_io_error_seen = 0;
1794 }
1795
1796 bio_put(bio);
1797 }
1798
1799 if (sblock->no_io_error_seen)
1800 scrub_recheck_block_checksum(sblock);
1801}
1802
1803static inline int scrub_check_fsid(u8 fsid[],
1804 struct scrub_page *spage)
1805{
1806 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1807 int ret;
1808
1809 ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1810 return !ret;
1811}
1812
1813static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1814{
1815 sblock->header_error = 0;
1816 sblock->checksum_error = 0;
1817 sblock->generation_error = 0;
1818
1819 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1820 scrub_checksum_data(sblock);
1821 else
1822 scrub_checksum_tree_block(sblock);
1823}
1824
1825static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1826 struct scrub_block *sblock_good)
1827{
1828 int page_num;
1829 int ret = 0;
1830
1831 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1832 int ret_sub;
1833
1834 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1835 sblock_good,
1836 page_num, 1);
1837 if (ret_sub)
1838 ret = ret_sub;
1839 }
1840
1841 return ret;
1842}
1843
1844static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1845 struct scrub_block *sblock_good,
1846 int page_num, int force_write)
1847{
1848 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1849 struct scrub_page *page_good = sblock_good->pagev[page_num];
1850 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1851
1852 BUG_ON(page_bad->page == NULL);
1853 BUG_ON(page_good->page == NULL);
1854 if (force_write || sblock_bad->header_error ||
1855 sblock_bad->checksum_error || page_bad->io_error) {
1856 struct bio *bio;
1857 int ret;
1858
1859 if (!page_bad->dev->bdev) {
1860 btrfs_warn_rl(fs_info,
1861 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1862 return -EIO;
1863 }
1864
1865 bio = btrfs_io_bio_alloc(1);
1866 bio_set_dev(bio, page_bad->dev->bdev);
1867 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1868 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1869
1870 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1871 if (PAGE_SIZE != ret) {
1872 bio_put(bio);
1873 return -EIO;
1874 }
1875
1876 if (btrfsic_submit_bio_wait(bio)) {
1877 btrfs_dev_stat_inc_and_print(page_bad->dev,
1878 BTRFS_DEV_STAT_WRITE_ERRS);
1879 btrfs_dev_replace_stats_inc(
1880 &fs_info->dev_replace.num_write_errors);
1881 bio_put(bio);
1882 return -EIO;
1883 }
1884 bio_put(bio);
1885 }
1886
1887 return 0;
1888}
1889
1890static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1891{
1892 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1893 int page_num;
1894
1895 /*
1896 * This block is used for the check of the parity on the source device,
1897 * so the data needn't be written into the destination device.
1898 */
1899 if (sblock->sparity)
1900 return;
1901
1902 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1903 int ret;
1904
1905 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1906 if (ret)
1907 btrfs_dev_replace_stats_inc(
1908 &fs_info->dev_replace.num_write_errors);
1909 }
1910}
1911
1912static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1913 int page_num)
1914{
1915 struct scrub_page *spage = sblock->pagev[page_num];
1916
1917 BUG_ON(spage->page == NULL);
1918 if (spage->io_error) {
1919 void *mapped_buffer = kmap_atomic(spage->page);
1920
1921 clear_page(mapped_buffer);
1922 flush_dcache_page(spage->page);
1923 kunmap_atomic(mapped_buffer);
1924 }
1925 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1926}
1927
1928static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1929 struct scrub_page *spage)
1930{
1931 struct scrub_bio *sbio;
1932 int ret;
1933
1934 mutex_lock(&sctx->wr_lock);
1935again:
1936 if (!sctx->wr_curr_bio) {
1937 sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
1938 GFP_KERNEL);
1939 if (!sctx->wr_curr_bio) {
1940 mutex_unlock(&sctx->wr_lock);
1941 return -ENOMEM;
1942 }
1943 sctx->wr_curr_bio->sctx = sctx;
1944 sctx->wr_curr_bio->page_count = 0;
1945 }
1946 sbio = sctx->wr_curr_bio;
1947 if (sbio->page_count == 0) {
1948 struct bio *bio;
1949
1950 sbio->physical = spage->physical_for_dev_replace;
1951 sbio->logical = spage->logical;
1952 sbio->dev = sctx->wr_tgtdev;
1953 bio = sbio->bio;
1954 if (!bio) {
1955 bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
1956 sbio->bio = bio;
1957 }
1958
1959 bio->bi_private = sbio;
1960 bio->bi_end_io = scrub_wr_bio_end_io;
1961 bio_set_dev(bio, sbio->dev->bdev);
1962 bio->bi_iter.bi_sector = sbio->physical >> 9;
1963 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1964 sbio->status = 0;
1965 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1966 spage->physical_for_dev_replace ||
1967 sbio->logical + sbio->page_count * PAGE_SIZE !=
1968 spage->logical) {
1969 scrub_wr_submit(sctx);
1970 goto again;
1971 }
1972
1973 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1974 if (ret != PAGE_SIZE) {
1975 if (sbio->page_count < 1) {
1976 bio_put(sbio->bio);
1977 sbio->bio = NULL;
1978 mutex_unlock(&sctx->wr_lock);
1979 return -EIO;
1980 }
1981 scrub_wr_submit(sctx);
1982 goto again;
1983 }
1984
1985 sbio->pagev[sbio->page_count] = spage;
1986 scrub_page_get(spage);
1987 sbio->page_count++;
1988 if (sbio->page_count == sctx->pages_per_wr_bio)
1989 scrub_wr_submit(sctx);
1990 mutex_unlock(&sctx->wr_lock);
1991
1992 return 0;
1993}
1994
1995static void scrub_wr_submit(struct scrub_ctx *sctx)
1996{
1997 struct scrub_bio *sbio;
1998
1999 if (!sctx->wr_curr_bio)
2000 return;
2001
2002 sbio = sctx->wr_curr_bio;
2003 sctx->wr_curr_bio = NULL;
2004 WARN_ON(!sbio->bio->bi_disk);
2005 scrub_pending_bio_inc(sctx);
2006 /* process all writes in a single worker thread. Then the block layer
2007 * orders the requests before sending them to the driver which
2008 * doubled the write performance on spinning disks when measured
2009 * with Linux 3.5 */
2010 btrfsic_submit_bio(sbio->bio);
2011}
2012
2013static void scrub_wr_bio_end_io(struct bio *bio)
2014{
2015 struct scrub_bio *sbio = bio->bi_private;
2016 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2017
2018 sbio->status = bio->bi_status;
2019 sbio->bio = bio;
2020
2021 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
2022 scrub_wr_bio_end_io_worker, NULL, NULL);
2023 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
2024}
2025
2026static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
2027{
2028 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2029 struct scrub_ctx *sctx = sbio->sctx;
2030 int i;
2031
2032 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
2033 if (sbio->status) {
2034 struct btrfs_dev_replace *dev_replace =
2035 &sbio->sctx->fs_info->dev_replace;
2036
2037 for (i = 0; i < sbio->page_count; i++) {
2038 struct scrub_page *spage = sbio->pagev[i];
2039
2040 spage->io_error = 1;
2041 btrfs_dev_replace_stats_inc(&dev_replace->
2042 num_write_errors);
2043 }
2044 }
2045
2046 for (i = 0; i < sbio->page_count; i++)
2047 scrub_page_put(sbio->pagev[i]);
2048
2049 bio_put(sbio->bio);
2050 kfree(sbio);
2051 scrub_pending_bio_dec(sctx);
2052}
2053
2054static int scrub_checksum(struct scrub_block *sblock)
2055{
2056 u64 flags;
2057 int ret;
2058
2059 /*
2060 * No need to initialize these stats currently,
2061 * because this function only use return value
2062 * instead of these stats value.
2063 *
2064 * Todo:
2065 * always use stats
2066 */
2067 sblock->header_error = 0;
2068 sblock->generation_error = 0;
2069 sblock->checksum_error = 0;
2070
2071 WARN_ON(sblock->page_count < 1);
2072 flags = sblock->pagev[0]->flags;
2073 ret = 0;
2074 if (flags & BTRFS_EXTENT_FLAG_DATA)
2075 ret = scrub_checksum_data(sblock);
2076 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
2077 ret = scrub_checksum_tree_block(sblock);
2078 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
2079 (void)scrub_checksum_super(sblock);
2080 else
2081 WARN_ON(1);
2082 if (ret)
2083 scrub_handle_errored_block(sblock);
2084
2085 return ret;
2086}
2087
2088static int scrub_checksum_data(struct scrub_block *sblock)
2089{
2090 struct scrub_ctx *sctx = sblock->sctx;
2091 u8 csum[BTRFS_CSUM_SIZE];
2092 u8 *on_disk_csum;
2093 struct page *page;
2094 void *buffer;
2095 u32 crc = ~(u32)0;
2096 u64 len;
2097 int index;
2098
2099 BUG_ON(sblock->page_count < 1);
2100 if (!sblock->pagev[0]->have_csum)
2101 return 0;
2102
2103 on_disk_csum = sblock->pagev[0]->csum;
2104 page = sblock->pagev[0]->page;
2105 buffer = kmap_atomic(page);
2106
2107 len = sctx->fs_info->sectorsize;
2108 index = 0;
2109 for (;;) {
2110 u64 l = min_t(u64, len, PAGE_SIZE);
2111
2112 crc = btrfs_csum_data(buffer, crc, l);
2113 kunmap_atomic(buffer);
2114 len -= l;
2115 if (len == 0)
2116 break;
2117 index++;
2118 BUG_ON(index >= sblock->page_count);
2119 BUG_ON(!sblock->pagev[index]->page);
2120 page = sblock->pagev[index]->page;
2121 buffer = kmap_atomic(page);
2122 }
2123
2124 btrfs_csum_final(crc, csum);
2125 if (memcmp(csum, on_disk_csum, sctx->csum_size))
2126 sblock->checksum_error = 1;
2127
2128 return sblock->checksum_error;
2129}
2130
2131static int scrub_checksum_tree_block(struct scrub_block *sblock)
2132{
2133 struct scrub_ctx *sctx = sblock->sctx;
2134 struct btrfs_header *h;
2135 struct btrfs_fs_info *fs_info = sctx->fs_info;
2136 u8 calculated_csum[BTRFS_CSUM_SIZE];
2137 u8 on_disk_csum[BTRFS_CSUM_SIZE];
2138 struct page *page;
2139 void *mapped_buffer;
2140 u64 mapped_size;
2141 void *p;
2142 u32 crc = ~(u32)0;
2143 u64 len;
2144 int index;
2145
2146 BUG_ON(sblock->page_count < 1);
2147 page = sblock->pagev[0]->page;
2148 mapped_buffer = kmap_atomic(page);
2149 h = (struct btrfs_header *)mapped_buffer;
2150 memcpy(on_disk_csum, h->csum, sctx->csum_size);
2151
2152 /*
2153 * we don't use the getter functions here, as we
2154 * a) don't have an extent buffer and
2155 * b) the page is already kmapped
2156 */
2157 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
2158 sblock->header_error = 1;
2159
2160 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
2161 sblock->header_error = 1;
2162 sblock->generation_error = 1;
2163 }
2164
2165 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
2166 sblock->header_error = 1;
2167
2168 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
2169 BTRFS_UUID_SIZE))
2170 sblock->header_error = 1;
2171
2172 len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
2173 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
2174 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
2175 index = 0;
2176 for (;;) {
2177 u64 l = min_t(u64, len, mapped_size);
2178
2179 crc = btrfs_csum_data(p, crc, l);
2180 kunmap_atomic(mapped_buffer);
2181 len -= l;
2182 if (len == 0)
2183 break;
2184 index++;
2185 BUG_ON(index >= sblock->page_count);
2186 BUG_ON(!sblock->pagev[index]->page);
2187 page = sblock->pagev[index]->page;
2188 mapped_buffer = kmap_atomic(page);
2189 mapped_size = PAGE_SIZE;
2190 p = mapped_buffer;
2191 }
2192
2193 btrfs_csum_final(crc, calculated_csum);
2194 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
2195 sblock->checksum_error = 1;
2196
2197 return sblock->header_error || sblock->checksum_error;
2198}
2199
2200static int scrub_checksum_super(struct scrub_block *sblock)
2201{
2202 struct btrfs_super_block *s;
2203 struct scrub_ctx *sctx = sblock->sctx;
2204 u8 calculated_csum[BTRFS_CSUM_SIZE];
2205 u8 on_disk_csum[BTRFS_CSUM_SIZE];
2206 struct page *page;
2207 void *mapped_buffer;
2208 u64 mapped_size;
2209 void *p;
2210 u32 crc = ~(u32)0;
2211 int fail_gen = 0;
2212 int fail_cor = 0;
2213 u64 len;
2214 int index;
2215
2216 BUG_ON(sblock->page_count < 1);
2217 page = sblock->pagev[0]->page;
2218 mapped_buffer = kmap_atomic(page);
2219 s = (struct btrfs_super_block *)mapped_buffer;
2220 memcpy(on_disk_csum, s->csum, sctx->csum_size);
2221
2222 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
2223 ++fail_cor;
2224
2225 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
2226 ++fail_gen;
2227
2228 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
2229 ++fail_cor;
2230
2231 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
2232 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
2233 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
2234 index = 0;
2235 for (;;) {
2236 u64 l = min_t(u64, len, mapped_size);
2237
2238 crc = btrfs_csum_data(p, crc, l);
2239 kunmap_atomic(mapped_buffer);
2240 len -= l;
2241 if (len == 0)
2242 break;
2243 index++;
2244 BUG_ON(index >= sblock->page_count);
2245 BUG_ON(!sblock->pagev[index]->page);
2246 page = sblock->pagev[index]->page;
2247 mapped_buffer = kmap_atomic(page);
2248 mapped_size = PAGE_SIZE;
2249 p = mapped_buffer;
2250 }
2251
2252 btrfs_csum_final(crc, calculated_csum);
2253 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
2254 ++fail_cor;
2255
2256 if (fail_cor + fail_gen) {
2257 /*
2258 * if we find an error in a super block, we just report it.
2259 * They will get written with the next transaction commit
2260 * anyway
2261 */
2262 spin_lock(&sctx->stat_lock);
2263 ++sctx->stat.super_errors;
2264 spin_unlock(&sctx->stat_lock);
2265 if (fail_cor)
2266 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2267 BTRFS_DEV_STAT_CORRUPTION_ERRS);
2268 else
2269 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
2270 BTRFS_DEV_STAT_GENERATION_ERRS);
2271 }
2272
2273 return fail_cor + fail_gen;
2274}
2275
2276static void scrub_block_get(struct scrub_block *sblock)
2277{
2278 refcount_inc(&sblock->refs);
2279}
2280
2281static void scrub_block_put(struct scrub_block *sblock)
2282{
2283 if (refcount_dec_and_test(&sblock->refs)) {
2284 int i;
2285
2286 if (sblock->sparity)
2287 scrub_parity_put(sblock->sparity);
2288
2289 for (i = 0; i < sblock->page_count; i++)
2290 scrub_page_put(sblock->pagev[i]);
2291 kfree(sblock);
2292 }
2293}
2294
2295static void scrub_page_get(struct scrub_page *spage)
2296{
2297 atomic_inc(&spage->refs);
2298}
2299
2300static void scrub_page_put(struct scrub_page *spage)
2301{
2302 if (atomic_dec_and_test(&spage->refs)) {
2303 if (spage->page)
2304 __free_page(spage->page);
2305 kfree(spage);
2306 }
2307}
2308
2309static void scrub_submit(struct scrub_ctx *sctx)
2310{
2311 struct scrub_bio *sbio;
2312
2313 if (sctx->curr == -1)
2314 return;
2315
2316 sbio = sctx->bios[sctx->curr];
2317 sctx->curr = -1;
2318 scrub_pending_bio_inc(sctx);
2319 btrfsic_submit_bio(sbio->bio);
2320}
2321
2322static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2323 struct scrub_page *spage)
2324{
2325 struct scrub_block *sblock = spage->sblock;
2326 struct scrub_bio *sbio;
2327 int ret;
2328
2329again:
2330 /*
2331 * grab a fresh bio or wait for one to become available
2332 */
2333 while (sctx->curr == -1) {
2334 spin_lock(&sctx->list_lock);
2335 sctx->curr = sctx->first_free;
2336 if (sctx->curr != -1) {
2337 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2338 sctx->bios[sctx->curr]->next_free = -1;
2339 sctx->bios[sctx->curr]->page_count = 0;
2340 spin_unlock(&sctx->list_lock);
2341 } else {
2342 spin_unlock(&sctx->list_lock);
2343 wait_event(sctx->list_wait, sctx->first_free != -1);
2344 }
2345 }
2346 sbio = sctx->bios[sctx->curr];
2347 if (sbio->page_count == 0) {
2348 struct bio *bio;
2349
2350 sbio->physical = spage->physical;
2351 sbio->logical = spage->logical;
2352 sbio->dev = spage->dev;
2353 bio = sbio->bio;
2354 if (!bio) {
2355 bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
2356 sbio->bio = bio;
2357 }
2358
2359 bio->bi_private = sbio;
2360 bio->bi_end_io = scrub_bio_end_io;
2361 bio_set_dev(bio, sbio->dev->bdev);
2362 bio->bi_iter.bi_sector = sbio->physical >> 9;
2363 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2364 sbio->status = 0;
2365 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2366 spage->physical ||
2367 sbio->logical + sbio->page_count * PAGE_SIZE !=
2368 spage->logical ||
2369 sbio->dev != spage->dev) {
2370 scrub_submit(sctx);
2371 goto again;
2372 }
2373
2374 sbio->pagev[sbio->page_count] = spage;
2375 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2376 if (ret != PAGE_SIZE) {
2377 if (sbio->page_count < 1) {
2378 bio_put(sbio->bio);
2379 sbio->bio = NULL;
2380 return -EIO;
2381 }
2382 scrub_submit(sctx);
2383 goto again;
2384 }
2385
2386 scrub_block_get(sblock); /* one for the page added to the bio */
2387 atomic_inc(&sblock->outstanding_pages);
2388 sbio->page_count++;
2389 if (sbio->page_count == sctx->pages_per_rd_bio)
2390 scrub_submit(sctx);
2391
2392 return 0;
2393}
2394
2395static void scrub_missing_raid56_end_io(struct bio *bio)
2396{
2397 struct scrub_block *sblock = bio->bi_private;
2398 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2399
2400 if (bio->bi_status)
2401 sblock->no_io_error_seen = 0;
2402
2403 bio_put(bio);
2404
2405 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2406}
2407
2408static void scrub_missing_raid56_worker(struct btrfs_work *work)
2409{
2410 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2411 struct scrub_ctx *sctx = sblock->sctx;
2412 struct btrfs_fs_info *fs_info = sctx->fs_info;
2413 u64 logical;
2414 struct btrfs_device *dev;
2415
2416 logical = sblock->pagev[0]->logical;
2417 dev = sblock->pagev[0]->dev;
2418
2419 if (sblock->no_io_error_seen)
2420 scrub_recheck_block_checksum(sblock);
2421
2422 if (!sblock->no_io_error_seen) {
2423 spin_lock(&sctx->stat_lock);
2424 sctx->stat.read_errors++;
2425 spin_unlock(&sctx->stat_lock);
2426 btrfs_err_rl_in_rcu(fs_info,
2427 "IO error rebuilding logical %llu for dev %s",
2428 logical, rcu_str_deref(dev->name));
2429 } else if (sblock->header_error || sblock->checksum_error) {
2430 spin_lock(&sctx->stat_lock);
2431 sctx->stat.uncorrectable_errors++;
2432 spin_unlock(&sctx->stat_lock);
2433 btrfs_err_rl_in_rcu(fs_info,
2434 "failed to rebuild valid logical %llu for dev %s",
2435 logical, rcu_str_deref(dev->name));
2436 } else {
2437 scrub_write_block_to_dev_replace(sblock);
2438 }
2439
2440 scrub_block_put(sblock);
2441
2442 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2443 mutex_lock(&sctx->wr_lock);
2444 scrub_wr_submit(sctx);
2445 mutex_unlock(&sctx->wr_lock);
2446 }
2447
2448 scrub_pending_bio_dec(sctx);
2449}
2450
2451static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2452{
2453 struct scrub_ctx *sctx = sblock->sctx;
2454 struct btrfs_fs_info *fs_info = sctx->fs_info;
2455 u64 length = sblock->page_count * PAGE_SIZE;
2456 u64 logical = sblock->pagev[0]->logical;
2457 struct btrfs_bio *bbio = NULL;
2458 struct bio *bio;
2459 struct btrfs_raid_bio *rbio;
2460 int ret;
2461 int i;
2462
2463 btrfs_bio_counter_inc_blocked(fs_info);
2464 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2465 &length, &bbio);
2466 if (ret || !bbio || !bbio->raid_map)
2467 goto bbio_out;
2468
2469 if (WARN_ON(!sctx->is_dev_replace ||
2470 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2471 /*
2472 * We shouldn't be scrubbing a missing device. Even for dev
2473 * replace, we should only get here for RAID 5/6. We either
2474 * managed to mount something with no mirrors remaining or
2475 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2476 */
2477 goto bbio_out;
2478 }
2479
2480 bio = btrfs_io_bio_alloc(0);
2481 bio->bi_iter.bi_sector = logical >> 9;
2482 bio->bi_private = sblock;
2483 bio->bi_end_io = scrub_missing_raid56_end_io;
2484
2485 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2486 if (!rbio)
2487 goto rbio_out;
2488
2489 for (i = 0; i < sblock->page_count; i++) {
2490 struct scrub_page *spage = sblock->pagev[i];
2491
2492 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2493 }
2494
2495 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2496 scrub_missing_raid56_worker, NULL, NULL);
2497 scrub_block_get(sblock);
2498 scrub_pending_bio_inc(sctx);
2499 raid56_submit_missing_rbio(rbio);
2500 return;
2501
2502rbio_out:
2503 bio_put(bio);
2504bbio_out:
2505 btrfs_bio_counter_dec(fs_info);
2506 btrfs_put_bbio(bbio);
2507 spin_lock(&sctx->stat_lock);
2508 sctx->stat.malloc_errors++;
2509 spin_unlock(&sctx->stat_lock);
2510}
2511
2512static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2513 u64 physical, struct btrfs_device *dev, u64 flags,
2514 u64 gen, int mirror_num, u8 *csum, int force,
2515 u64 physical_for_dev_replace)
2516{
2517 struct scrub_block *sblock;
2518 int index;
2519
2520 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2521 if (!sblock) {
2522 spin_lock(&sctx->stat_lock);
2523 sctx->stat.malloc_errors++;
2524 spin_unlock(&sctx->stat_lock);
2525 return -ENOMEM;
2526 }
2527
2528 /* one ref inside this function, plus one for each page added to
2529 * a bio later on */
2530 refcount_set(&sblock->refs, 1);
2531 sblock->sctx = sctx;
2532 sblock->no_io_error_seen = 1;
2533
2534 for (index = 0; len > 0; index++) {
2535 struct scrub_page *spage;
2536 u64 l = min_t(u64, len, PAGE_SIZE);
2537
2538 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2539 if (!spage) {
2540leave_nomem:
2541 spin_lock(&sctx->stat_lock);
2542 sctx->stat.malloc_errors++;
2543 spin_unlock(&sctx->stat_lock);
2544 scrub_block_put(sblock);
2545 return -ENOMEM;
2546 }
2547 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2548 scrub_page_get(spage);
2549 sblock->pagev[index] = spage;
2550 spage->sblock = sblock;
2551 spage->dev = dev;
2552 spage->flags = flags;
2553 spage->generation = gen;
2554 spage->logical = logical;
2555 spage->physical = physical;
2556 spage->physical_for_dev_replace = physical_for_dev_replace;
2557 spage->mirror_num = mirror_num;
2558 if (csum) {
2559 spage->have_csum = 1;
2560 memcpy(spage->csum, csum, sctx->csum_size);
2561 } else {
2562 spage->have_csum = 0;
2563 }
2564 sblock->page_count++;
2565 spage->page = alloc_page(GFP_KERNEL);
2566 if (!spage->page)
2567 goto leave_nomem;
2568 len -= l;
2569 logical += l;
2570 physical += l;
2571 physical_for_dev_replace += l;
2572 }
2573
2574 WARN_ON(sblock->page_count == 0);
2575 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2576 /*
2577 * This case should only be hit for RAID 5/6 device replace. See
2578 * the comment in scrub_missing_raid56_pages() for details.
2579 */
2580 scrub_missing_raid56_pages(sblock);
2581 } else {
2582 for (index = 0; index < sblock->page_count; index++) {
2583 struct scrub_page *spage = sblock->pagev[index];
2584 int ret;
2585
2586 ret = scrub_add_page_to_rd_bio(sctx, spage);
2587 if (ret) {
2588 scrub_block_put(sblock);
2589 return ret;
2590 }
2591 }
2592
2593 if (force)
2594 scrub_submit(sctx);
2595 }
2596
2597 /* last one frees, either here or in bio completion for last page */
2598 scrub_block_put(sblock);
2599 return 0;
2600}
2601
2602static void scrub_bio_end_io(struct bio *bio)
2603{
2604 struct scrub_bio *sbio = bio->bi_private;
2605 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2606
2607 sbio->status = bio->bi_status;
2608 sbio->bio = bio;
2609
2610 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2611}
2612
2613static void scrub_bio_end_io_worker(struct btrfs_work *work)
2614{
2615 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2616 struct scrub_ctx *sctx = sbio->sctx;
2617 int i;
2618
2619 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2620 if (sbio->status) {
2621 for (i = 0; i < sbio->page_count; i++) {
2622 struct scrub_page *spage = sbio->pagev[i];
2623
2624 spage->io_error = 1;
2625 spage->sblock->no_io_error_seen = 0;
2626 }
2627 }
2628
2629 /* now complete the scrub_block items that have all pages completed */
2630 for (i = 0; i < sbio->page_count; i++) {
2631 struct scrub_page *spage = sbio->pagev[i];
2632 struct scrub_block *sblock = spage->sblock;
2633
2634 if (atomic_dec_and_test(&sblock->outstanding_pages))
2635 scrub_block_complete(sblock);
2636 scrub_block_put(sblock);
2637 }
2638
2639 bio_put(sbio->bio);
2640 sbio->bio = NULL;
2641 spin_lock(&sctx->list_lock);
2642 sbio->next_free = sctx->first_free;
2643 sctx->first_free = sbio->index;
2644 spin_unlock(&sctx->list_lock);
2645
2646 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2647 mutex_lock(&sctx->wr_lock);
2648 scrub_wr_submit(sctx);
2649 mutex_unlock(&sctx->wr_lock);
2650 }
2651
2652 scrub_pending_bio_dec(sctx);
2653}
2654
2655static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2656 unsigned long *bitmap,
2657 u64 start, u64 len)
2658{
2659 u64 offset;
2660 u64 nsectors64;
2661 u32 nsectors;
2662 int sectorsize = sparity->sctx->fs_info->sectorsize;
2663
2664 if (len >= sparity->stripe_len) {
2665 bitmap_set(bitmap, 0, sparity->nsectors);
2666 return;
2667 }
2668
2669 start -= sparity->logic_start;
2670 start = div64_u64_rem(start, sparity->stripe_len, &offset);
2671 offset = div_u64(offset, sectorsize);
2672 nsectors64 = div_u64(len, sectorsize);
2673
2674 ASSERT(nsectors64 < UINT_MAX);
2675 nsectors = (u32)nsectors64;
2676
2677 if (offset + nsectors <= sparity->nsectors) {
2678 bitmap_set(bitmap, offset, nsectors);
2679 return;
2680 }
2681
2682 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2683 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2684}
2685
2686static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2687 u64 start, u64 len)
2688{
2689 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2690}
2691
2692static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2693 u64 start, u64 len)
2694{
2695 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2696}
2697
2698static void scrub_block_complete(struct scrub_block *sblock)
2699{
2700 int corrupted = 0;
2701
2702 if (!sblock->no_io_error_seen) {
2703 corrupted = 1;
2704 scrub_handle_errored_block(sblock);
2705 } else {
2706 /*
2707 * if has checksum error, write via repair mechanism in
2708 * dev replace case, otherwise write here in dev replace
2709 * case.
2710 */
2711 corrupted = scrub_checksum(sblock);
2712 if (!corrupted && sblock->sctx->is_dev_replace)
2713 scrub_write_block_to_dev_replace(sblock);
2714 }
2715
2716 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2717 u64 start = sblock->pagev[0]->logical;
2718 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2719 PAGE_SIZE;
2720
2721 scrub_parity_mark_sectors_error(sblock->sparity,
2722 start, end - start);
2723 }
2724}
2725
2726static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2727{
2728 struct btrfs_ordered_sum *sum = NULL;
2729 unsigned long index;
2730 unsigned long num_sectors;
2731
2732 while (!list_empty(&sctx->csum_list)) {
2733 sum = list_first_entry(&sctx->csum_list,
2734 struct btrfs_ordered_sum, list);
2735 if (sum->bytenr > logical)
2736 return 0;
2737 if (sum->bytenr + sum->len > logical)
2738 break;
2739
2740 ++sctx->stat.csum_discards;
2741 list_del(&sum->list);
2742 kfree(sum);
2743 sum = NULL;
2744 }
2745 if (!sum)
2746 return 0;
2747
2748 index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
2749 ASSERT(index < UINT_MAX);
2750
2751 num_sectors = sum->len / sctx->fs_info->sectorsize;
2752 memcpy(csum, sum->sums + index, sctx->csum_size);
2753 if (index == num_sectors - 1) {
2754 list_del(&sum->list);
2755 kfree(sum);
2756 }
2757 return 1;
2758}
2759
2760/* scrub extent tries to collect up to 64 kB for each bio */
2761static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
2762 u64 logical, u64 len,
2763 u64 physical, struct btrfs_device *dev, u64 flags,
2764 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2765{
2766 int ret;
2767 u8 csum[BTRFS_CSUM_SIZE];
2768 u32 blocksize;
2769
2770 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2771 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2772 blocksize = map->stripe_len;
2773 else
2774 blocksize = sctx->fs_info->sectorsize;
2775 spin_lock(&sctx->stat_lock);
2776 sctx->stat.data_extents_scrubbed++;
2777 sctx->stat.data_bytes_scrubbed += len;
2778 spin_unlock(&sctx->stat_lock);
2779 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2780 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2781 blocksize = map->stripe_len;
2782 else
2783 blocksize = sctx->fs_info->nodesize;
2784 spin_lock(&sctx->stat_lock);
2785 sctx->stat.tree_extents_scrubbed++;
2786 sctx->stat.tree_bytes_scrubbed += len;
2787 spin_unlock(&sctx->stat_lock);
2788 } else {
2789 blocksize = sctx->fs_info->sectorsize;
2790 WARN_ON(1);
2791 }
2792
2793 while (len) {
2794 u64 l = min_t(u64, len, blocksize);
2795 int have_csum = 0;
2796
2797 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2798 /* push csums to sbio */
2799 have_csum = scrub_find_csum(sctx, logical, csum);
2800 if (have_csum == 0)
2801 ++sctx->stat.no_csum;
2802 if (sctx->is_dev_replace && !have_csum) {
2803 ret = copy_nocow_pages(sctx, logical, l,
2804 mirror_num,
2805 physical_for_dev_replace);
2806 goto behind_scrub_pages;
2807 }
2808 }
2809 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2810 mirror_num, have_csum ? csum : NULL, 0,
2811 physical_for_dev_replace);
2812behind_scrub_pages:
2813 if (ret)
2814 return ret;
2815 len -= l;
2816 logical += l;
2817 physical += l;
2818 physical_for_dev_replace += l;
2819 }
2820 return 0;
2821}
2822
2823static int scrub_pages_for_parity(struct scrub_parity *sparity,
2824 u64 logical, u64 len,
2825 u64 physical, struct btrfs_device *dev,
2826 u64 flags, u64 gen, int mirror_num, u8 *csum)
2827{
2828 struct scrub_ctx *sctx = sparity->sctx;
2829 struct scrub_block *sblock;
2830 int index;
2831
2832 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2833 if (!sblock) {
2834 spin_lock(&sctx->stat_lock);
2835 sctx->stat.malloc_errors++;
2836 spin_unlock(&sctx->stat_lock);
2837 return -ENOMEM;
2838 }
2839
2840 /* one ref inside this function, plus one for each page added to
2841 * a bio later on */
2842 refcount_set(&sblock->refs, 1);
2843 sblock->sctx = sctx;
2844 sblock->no_io_error_seen = 1;
2845 sblock->sparity = sparity;
2846 scrub_parity_get(sparity);
2847
2848 for (index = 0; len > 0; index++) {
2849 struct scrub_page *spage;
2850 u64 l = min_t(u64, len, PAGE_SIZE);
2851
2852 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2853 if (!spage) {
2854leave_nomem:
2855 spin_lock(&sctx->stat_lock);
2856 sctx->stat.malloc_errors++;
2857 spin_unlock(&sctx->stat_lock);
2858 scrub_block_put(sblock);
2859 return -ENOMEM;
2860 }
2861 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2862 /* For scrub block */
2863 scrub_page_get(spage);
2864 sblock->pagev[index] = spage;
2865 /* For scrub parity */
2866 scrub_page_get(spage);
2867 list_add_tail(&spage->list, &sparity->spages);
2868 spage->sblock = sblock;
2869 spage->dev = dev;
2870 spage->flags = flags;
2871 spage->generation = gen;
2872 spage->logical = logical;
2873 spage->physical = physical;
2874 spage->mirror_num = mirror_num;
2875 if (csum) {
2876 spage->have_csum = 1;
2877 memcpy(spage->csum, csum, sctx->csum_size);
2878 } else {
2879 spage->have_csum = 0;
2880 }
2881 sblock->page_count++;
2882 spage->page = alloc_page(GFP_KERNEL);
2883 if (!spage->page)
2884 goto leave_nomem;
2885 len -= l;
2886 logical += l;
2887 physical += l;
2888 }
2889
2890 WARN_ON(sblock->page_count == 0);
2891 for (index = 0; index < sblock->page_count; index++) {
2892 struct scrub_page *spage = sblock->pagev[index];
2893 int ret;
2894
2895 ret = scrub_add_page_to_rd_bio(sctx, spage);
2896 if (ret) {
2897 scrub_block_put(sblock);
2898 return ret;
2899 }
2900 }
2901
2902 /* last one frees, either here or in bio completion for last page */
2903 scrub_block_put(sblock);
2904 return 0;
2905}
2906
2907static int scrub_extent_for_parity(struct scrub_parity *sparity,
2908 u64 logical, u64 len,
2909 u64 physical, struct btrfs_device *dev,
2910 u64 flags, u64 gen, int mirror_num)
2911{
2912 struct scrub_ctx *sctx = sparity->sctx;
2913 int ret;
2914 u8 csum[BTRFS_CSUM_SIZE];
2915 u32 blocksize;
2916
2917 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2918 scrub_parity_mark_sectors_error(sparity, logical, len);
2919 return 0;
2920 }
2921
2922 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2923 blocksize = sparity->stripe_len;
2924 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2925 blocksize = sparity->stripe_len;
2926 } else {
2927 blocksize = sctx->fs_info->sectorsize;
2928 WARN_ON(1);
2929 }
2930
2931 while (len) {
2932 u64 l = min_t(u64, len, blocksize);
2933 int have_csum = 0;
2934
2935 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2936 /* push csums to sbio */
2937 have_csum = scrub_find_csum(sctx, logical, csum);
2938 if (have_csum == 0)
2939 goto skip;
2940 }
2941 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2942 flags, gen, mirror_num,
2943 have_csum ? csum : NULL);
2944 if (ret)
2945 return ret;
2946skip:
2947 len -= l;
2948 logical += l;
2949 physical += l;
2950 }
2951 return 0;
2952}
2953
2954/*
2955 * Given a physical address, this will calculate it's
2956 * logical offset. if this is a parity stripe, it will return
2957 * the most left data stripe's logical offset.
2958 *
2959 * return 0 if it is a data stripe, 1 means parity stripe.
2960 */
2961static int get_raid56_logic_offset(u64 physical, int num,
2962 struct map_lookup *map, u64 *offset,
2963 u64 *stripe_start)
2964{
2965 int i;
2966 int j = 0;
2967 u64 stripe_nr;
2968 u64 last_offset;
2969 u32 stripe_index;
2970 u32 rot;
2971
2972 last_offset = (physical - map->stripes[num].physical) *
2973 nr_data_stripes(map);
2974 if (stripe_start)
2975 *stripe_start = last_offset;
2976
2977 *offset = last_offset;
2978 for (i = 0; i < nr_data_stripes(map); i++) {
2979 *offset = last_offset + i * map->stripe_len;
2980
2981 stripe_nr = div64_u64(*offset, map->stripe_len);
2982 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2983
2984 /* Work out the disk rotation on this stripe-set */
2985 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2986 /* calculate which stripe this data locates */
2987 rot += i;
2988 stripe_index = rot % map->num_stripes;
2989 if (stripe_index == num)
2990 return 0;
2991 if (stripe_index < num)
2992 j++;
2993 }
2994 *offset = last_offset + j * map->stripe_len;
2995 return 1;
2996}
2997
2998static void scrub_free_parity(struct scrub_parity *sparity)
2999{
3000 struct scrub_ctx *sctx = sparity->sctx;
3001 struct scrub_page *curr, *next;
3002 int nbits;
3003
3004 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
3005 if (nbits) {
3006 spin_lock(&sctx->stat_lock);
3007 sctx->stat.read_errors += nbits;
3008 sctx->stat.uncorrectable_errors += nbits;
3009 spin_unlock(&sctx->stat_lock);
3010 }
3011
3012 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
3013 list_del_init(&curr->list);
3014 scrub_page_put(curr);
3015 }
3016
3017 kfree(sparity);
3018}
3019
3020static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
3021{
3022 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
3023 work);
3024 struct scrub_ctx *sctx = sparity->sctx;
3025
3026 scrub_free_parity(sparity);
3027 scrub_pending_bio_dec(sctx);
3028}
3029
3030static void scrub_parity_bio_endio(struct bio *bio)
3031{
3032 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
3033 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
3034
3035 if (bio->bi_status)
3036 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
3037 sparity->nsectors);
3038
3039 bio_put(bio);
3040
3041 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
3042 scrub_parity_bio_endio_worker, NULL, NULL);
3043 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
3044}
3045
3046static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
3047{
3048 struct scrub_ctx *sctx = sparity->sctx;
3049 struct btrfs_fs_info *fs_info = sctx->fs_info;
3050 struct bio *bio;
3051 struct btrfs_raid_bio *rbio;
3052 struct btrfs_bio *bbio = NULL;
3053 u64 length;
3054 int ret;
3055
3056 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
3057 sparity->nsectors))
3058 goto out;
3059
3060 length = sparity->logic_end - sparity->logic_start;
3061
3062 btrfs_bio_counter_inc_blocked(fs_info);
3063 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
3064 &length, &bbio);
3065 if (ret || !bbio || !bbio->raid_map)
3066 goto bbio_out;
3067
3068 bio = btrfs_io_bio_alloc(0);
3069 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
3070 bio->bi_private = sparity;
3071 bio->bi_end_io = scrub_parity_bio_endio;
3072
3073 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
3074 length, sparity->scrub_dev,
3075 sparity->dbitmap,
3076 sparity->nsectors);
3077 if (!rbio)
3078 goto rbio_out;
3079
3080 scrub_pending_bio_inc(sctx);
3081 raid56_parity_submit_scrub_rbio(rbio);
3082 return;
3083
3084rbio_out:
3085 bio_put(bio);
3086bbio_out:
3087 btrfs_bio_counter_dec(fs_info);
3088 btrfs_put_bbio(bbio);
3089 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
3090 sparity->nsectors);
3091 spin_lock(&sctx->stat_lock);
3092 sctx->stat.malloc_errors++;
3093 spin_unlock(&sctx->stat_lock);
3094out:
3095 scrub_free_parity(sparity);
3096}
3097
3098static inline int scrub_calc_parity_bitmap_len(int nsectors)
3099{
3100 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
3101}
3102
3103static void scrub_parity_get(struct scrub_parity *sparity)
3104{
3105 refcount_inc(&sparity->refs);
3106}
3107
3108static void scrub_parity_put(struct scrub_parity *sparity)
3109{
3110 if (!refcount_dec_and_test(&sparity->refs))
3111 return;
3112
3113 scrub_parity_check_and_repair(sparity);
3114}
3115
3116static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
3117 struct map_lookup *map,
3118 struct btrfs_device *sdev,
3119 struct btrfs_path *path,
3120 u64 logic_start,
3121 u64 logic_end)
3122{
3123 struct btrfs_fs_info *fs_info = sctx->fs_info;
3124 struct btrfs_root *root = fs_info->extent_root;
3125 struct btrfs_root *csum_root = fs_info->csum_root;
3126 struct btrfs_extent_item *extent;
3127 struct btrfs_bio *bbio = NULL;
3128 u64 flags;
3129 int ret;
3130 int slot;
3131 struct extent_buffer *l;
3132 struct btrfs_key key;
3133 u64 generation;
3134 u64 extent_logical;
3135 u64 extent_physical;
3136 u64 extent_len;
3137 u64 mapped_length;
3138 struct btrfs_device *extent_dev;
3139 struct scrub_parity *sparity;
3140 int nsectors;
3141 int bitmap_len;
3142 int extent_mirror_num;
3143 int stop_loop = 0;
3144
3145 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
3146 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
3147 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
3148 GFP_NOFS);
3149 if (!sparity) {
3150 spin_lock(&sctx->stat_lock);
3151 sctx->stat.malloc_errors++;
3152 spin_unlock(&sctx->stat_lock);
3153 return -ENOMEM;
3154 }
3155
3156 sparity->stripe_len = map->stripe_len;
3157 sparity->nsectors = nsectors;
3158 sparity->sctx = sctx;
3159 sparity->scrub_dev = sdev;
3160 sparity->logic_start = logic_start;
3161 sparity->logic_end = logic_end;
3162 refcount_set(&sparity->refs, 1);
3163 INIT_LIST_HEAD(&sparity->spages);
3164 sparity->dbitmap = sparity->bitmap;
3165 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
3166
3167 ret = 0;
3168 while (logic_start < logic_end) {
3169 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3170 key.type = BTRFS_METADATA_ITEM_KEY;
3171 else
3172 key.type = BTRFS_EXTENT_ITEM_KEY;
3173 key.objectid = logic_start;
3174 key.offset = (u64)-1;
3175
3176 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3177 if (ret < 0)
3178 goto out;
3179
3180 if (ret > 0) {
3181 ret = btrfs_previous_extent_item(root, path, 0);
3182 if (ret < 0)
3183 goto out;
3184 if (ret > 0) {
3185 btrfs_release_path(path);
3186 ret = btrfs_search_slot(NULL, root, &key,
3187 path, 0, 0);
3188 if (ret < 0)
3189 goto out;
3190 }
3191 }
3192
3193 stop_loop = 0;
3194 while (1) {
3195 u64 bytes;
3196
3197 l = path->nodes[0];
3198 slot = path->slots[0];
3199 if (slot >= btrfs_header_nritems(l)) {
3200 ret = btrfs_next_leaf(root, path);
3201 if (ret == 0)
3202 continue;
3203 if (ret < 0)
3204 goto out;
3205
3206 stop_loop = 1;
3207 break;
3208 }
3209 btrfs_item_key_to_cpu(l, &key, slot);
3210
3211 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3212 key.type != BTRFS_METADATA_ITEM_KEY)
3213 goto next;
3214
3215 if (key.type == BTRFS_METADATA_ITEM_KEY)
3216 bytes = fs_info->nodesize;
3217 else
3218 bytes = key.offset;
3219
3220 if (key.objectid + bytes <= logic_start)
3221 goto next;
3222
3223 if (key.objectid >= logic_end) {
3224 stop_loop = 1;
3225 break;
3226 }
3227
3228 while (key.objectid >= logic_start + map->stripe_len)
3229 logic_start += map->stripe_len;
3230
3231 extent = btrfs_item_ptr(l, slot,
3232 struct btrfs_extent_item);
3233 flags = btrfs_extent_flags(l, extent);
3234 generation = btrfs_extent_generation(l, extent);
3235
3236 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3237 (key.objectid < logic_start ||
3238 key.objectid + bytes >
3239 logic_start + map->stripe_len)) {
3240 btrfs_err(fs_info,
3241 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3242 key.objectid, logic_start);
3243 spin_lock(&sctx->stat_lock);
3244 sctx->stat.uncorrectable_errors++;
3245 spin_unlock(&sctx->stat_lock);
3246 goto next;
3247 }
3248again:
3249 extent_logical = key.objectid;
3250 extent_len = bytes;
3251
3252 if (extent_logical < logic_start) {
3253 extent_len -= logic_start - extent_logical;
3254 extent_logical = logic_start;
3255 }
3256
3257 if (extent_logical + extent_len >
3258 logic_start + map->stripe_len)
3259 extent_len = logic_start + map->stripe_len -
3260 extent_logical;
3261
3262 scrub_parity_mark_sectors_data(sparity, extent_logical,
3263 extent_len);
3264
3265 mapped_length = extent_len;
3266 bbio = NULL;
3267 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
3268 extent_logical, &mapped_length, &bbio,
3269 0);
3270 if (!ret) {
3271 if (!bbio || mapped_length < extent_len)
3272 ret = -EIO;
3273 }
3274 if (ret) {
3275 btrfs_put_bbio(bbio);
3276 goto out;
3277 }
3278 extent_physical = bbio->stripes[0].physical;
3279 extent_mirror_num = bbio->mirror_num;
3280 extent_dev = bbio->stripes[0].dev;
3281 btrfs_put_bbio(bbio);
3282
3283 ret = btrfs_lookup_csums_range(csum_root,
3284 extent_logical,
3285 extent_logical + extent_len - 1,
3286 &sctx->csum_list, 1);
3287 if (ret)
3288 goto out;
3289
3290 ret = scrub_extent_for_parity(sparity, extent_logical,
3291 extent_len,
3292 extent_physical,
3293 extent_dev, flags,
3294 generation,
3295 extent_mirror_num);
3296
3297 scrub_free_csums(sctx);
3298
3299 if (ret)
3300 goto out;
3301
3302 if (extent_logical + extent_len <
3303 key.objectid + bytes) {
3304 logic_start += map->stripe_len;
3305
3306 if (logic_start >= logic_end) {
3307 stop_loop = 1;
3308 break;
3309 }
3310
3311 if (logic_start < key.objectid + bytes) {
3312 cond_resched();
3313 goto again;
3314 }
3315 }
3316next:
3317 path->slots[0]++;
3318 }
3319
3320 btrfs_release_path(path);
3321
3322 if (stop_loop)
3323 break;
3324
3325 logic_start += map->stripe_len;
3326 }
3327out:
3328 if (ret < 0)
3329 scrub_parity_mark_sectors_error(sparity, logic_start,
3330 logic_end - logic_start);
3331 scrub_parity_put(sparity);
3332 scrub_submit(sctx);
3333 mutex_lock(&sctx->wr_lock);
3334 scrub_wr_submit(sctx);
3335 mutex_unlock(&sctx->wr_lock);
3336
3337 btrfs_release_path(path);
3338 return ret < 0 ? ret : 0;
3339}
3340
3341static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3342 struct map_lookup *map,
3343 struct btrfs_device *scrub_dev,
3344 int num, u64 base, u64 length,
3345 int is_dev_replace)
3346{
3347 struct btrfs_path *path, *ppath;
3348 struct btrfs_fs_info *fs_info = sctx->fs_info;
3349 struct btrfs_root *root = fs_info->extent_root;
3350 struct btrfs_root *csum_root = fs_info->csum_root;
3351 struct btrfs_extent_item *extent;
3352 struct blk_plug plug;
3353 u64 flags;
3354 int ret;
3355 int slot;
3356 u64 nstripes;
3357 struct extent_buffer *l;
3358 u64 physical;
3359 u64 logical;
3360 u64 logic_end;
3361 u64 physical_end;
3362 u64 generation;
3363 int mirror_num;
3364 struct reada_control *reada1;
3365 struct reada_control *reada2;
3366 struct btrfs_key key;
3367 struct btrfs_key key_end;
3368 u64 increment = map->stripe_len;
3369 u64 offset;
3370 u64 extent_logical;
3371 u64 extent_physical;
3372 u64 extent_len;
3373 u64 stripe_logical;
3374 u64 stripe_end;
3375 struct btrfs_device *extent_dev;
3376 int extent_mirror_num;
3377 int stop_loop = 0;
3378
3379 physical = map->stripes[num].physical;
3380 offset = 0;
3381 nstripes = div64_u64(length, map->stripe_len);
3382 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3383 offset = map->stripe_len * num;
3384 increment = map->stripe_len * map->num_stripes;
3385 mirror_num = 1;
3386 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3387 int factor = map->num_stripes / map->sub_stripes;
3388 offset = map->stripe_len * (num / map->sub_stripes);
3389 increment = map->stripe_len * factor;
3390 mirror_num = num % map->sub_stripes + 1;
3391 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3392 increment = map->stripe_len;
3393 mirror_num = num % map->num_stripes + 1;
3394 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3395 increment = map->stripe_len;
3396 mirror_num = num % map->num_stripes + 1;
3397 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3398 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3399 increment = map->stripe_len * nr_data_stripes(map);
3400 mirror_num = 1;
3401 } else {
3402 increment = map->stripe_len;
3403 mirror_num = 1;
3404 }
3405
3406 path = btrfs_alloc_path();
3407 if (!path)
3408 return -ENOMEM;
3409
3410 ppath = btrfs_alloc_path();
3411 if (!ppath) {
3412 btrfs_free_path(path);
3413 return -ENOMEM;
3414 }
3415
3416 /*
3417 * work on commit root. The related disk blocks are static as
3418 * long as COW is applied. This means, it is save to rewrite
3419 * them to repair disk errors without any race conditions
3420 */
3421 path->search_commit_root = 1;
3422 path->skip_locking = 1;
3423
3424 ppath->search_commit_root = 1;
3425 ppath->skip_locking = 1;
3426 /*
3427 * trigger the readahead for extent tree csum tree and wait for
3428 * completion. During readahead, the scrub is officially paused
3429 * to not hold off transaction commits
3430 */
3431 logical = base + offset;
3432 physical_end = physical + nstripes * map->stripe_len;
3433 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3434 get_raid56_logic_offset(physical_end, num,
3435 map, &logic_end, NULL);
3436 logic_end += base;
3437 } else {
3438 logic_end = logical + increment * nstripes;
3439 }
3440 wait_event(sctx->list_wait,
3441 atomic_read(&sctx->bios_in_flight) == 0);
3442 scrub_blocked_if_needed(fs_info);
3443
3444 /* FIXME it might be better to start readahead at commit root */
3445 key.objectid = logical;
3446 key.type = BTRFS_EXTENT_ITEM_KEY;
3447 key.offset = (u64)0;
3448 key_end.objectid = logic_end;
3449 key_end.type = BTRFS_METADATA_ITEM_KEY;
3450 key_end.offset = (u64)-1;
3451 reada1 = btrfs_reada_add(root, &key, &key_end);
3452
3453 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3454 key.type = BTRFS_EXTENT_CSUM_KEY;
3455 key.offset = logical;
3456 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3457 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3458 key_end.offset = logic_end;
3459 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3460
3461 if (!IS_ERR(reada1))
3462 btrfs_reada_wait(reada1);
3463 if (!IS_ERR(reada2))
3464 btrfs_reada_wait(reada2);
3465
3466
3467 /*
3468 * collect all data csums for the stripe to avoid seeking during
3469 * the scrub. This might currently (crc32) end up to be about 1MB
3470 */
3471 blk_start_plug(&plug);
3472
3473 /*
3474 * now find all extents for each stripe and scrub them
3475 */
3476 ret = 0;
3477 while (physical < physical_end) {
3478 /*
3479 * canceled?
3480 */
3481 if (atomic_read(&fs_info->scrub_cancel_req) ||
3482 atomic_read(&sctx->cancel_req)) {
3483 ret = -ECANCELED;
3484 goto out;
3485 }
3486 /*
3487 * check to see if we have to pause
3488 */
3489 if (atomic_read(&fs_info->scrub_pause_req)) {
3490 /* push queued extents */
3491 sctx->flush_all_writes = true;
3492 scrub_submit(sctx);
3493 mutex_lock(&sctx->wr_lock);
3494 scrub_wr_submit(sctx);
3495 mutex_unlock(&sctx->wr_lock);
3496 wait_event(sctx->list_wait,
3497 atomic_read(&sctx->bios_in_flight) == 0);
3498 sctx->flush_all_writes = false;
3499 scrub_blocked_if_needed(fs_info);
3500 }
3501
3502 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3503 ret = get_raid56_logic_offset(physical, num, map,
3504 &logical,
3505 &stripe_logical);
3506 logical += base;
3507 if (ret) {
3508 /* it is parity strip */
3509 stripe_logical += base;
3510 stripe_end = stripe_logical + increment;
3511 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3512 ppath, stripe_logical,
3513 stripe_end);
3514 if (ret)
3515 goto out;
3516 goto skip;
3517 }
3518 }
3519
3520 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3521 key.type = BTRFS_METADATA_ITEM_KEY;
3522 else
3523 key.type = BTRFS_EXTENT_ITEM_KEY;
3524 key.objectid = logical;
3525 key.offset = (u64)-1;
3526
3527 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3528 if (ret < 0)
3529 goto out;
3530
3531 if (ret > 0) {
3532 ret = btrfs_previous_extent_item(root, path, 0);
3533 if (ret < 0)
3534 goto out;
3535 if (ret > 0) {
3536 /* there's no smaller item, so stick with the
3537 * larger one */
3538 btrfs_release_path(path);
3539 ret = btrfs_search_slot(NULL, root, &key,
3540 path, 0, 0);
3541 if (ret < 0)
3542 goto out;
3543 }
3544 }
3545
3546 stop_loop = 0;
3547 while (1) {
3548 u64 bytes;
3549
3550 l = path->nodes[0];
3551 slot = path->slots[0];
3552 if (slot >= btrfs_header_nritems(l)) {
3553 ret = btrfs_next_leaf(root, path);
3554 if (ret == 0)
3555 continue;
3556 if (ret < 0)
3557 goto out;
3558
3559 stop_loop = 1;
3560 break;
3561 }
3562 btrfs_item_key_to_cpu(l, &key, slot);
3563
3564 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3565 key.type != BTRFS_METADATA_ITEM_KEY)
3566 goto next;
3567
3568 if (key.type == BTRFS_METADATA_ITEM_KEY)
3569 bytes = fs_info->nodesize;
3570 else
3571 bytes = key.offset;
3572
3573 if (key.objectid + bytes <= logical)
3574 goto next;
3575
3576 if (key.objectid >= logical + map->stripe_len) {
3577 /* out of this device extent */
3578 if (key.objectid >= logic_end)
3579 stop_loop = 1;
3580 break;
3581 }
3582
3583 extent = btrfs_item_ptr(l, slot,
3584 struct btrfs_extent_item);
3585 flags = btrfs_extent_flags(l, extent);
3586 generation = btrfs_extent_generation(l, extent);
3587
3588 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3589 (key.objectid < logical ||
3590 key.objectid + bytes >
3591 logical + map->stripe_len)) {
3592 btrfs_err(fs_info,
3593 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3594 key.objectid, logical);
3595 spin_lock(&sctx->stat_lock);
3596 sctx->stat.uncorrectable_errors++;
3597 spin_unlock(&sctx->stat_lock);
3598 goto next;
3599 }
3600
3601again:
3602 extent_logical = key.objectid;
3603 extent_len = bytes;
3604
3605 /*
3606 * trim extent to this stripe
3607 */
3608 if (extent_logical < logical) {
3609 extent_len -= logical - extent_logical;
3610 extent_logical = logical;
3611 }
3612 if (extent_logical + extent_len >
3613 logical + map->stripe_len) {
3614 extent_len = logical + map->stripe_len -
3615 extent_logical;
3616 }
3617
3618 extent_physical = extent_logical - logical + physical;
3619 extent_dev = scrub_dev;
3620 extent_mirror_num = mirror_num;
3621 if (is_dev_replace)
3622 scrub_remap_extent(fs_info, extent_logical,
3623 extent_len, &extent_physical,
3624 &extent_dev,
3625 &extent_mirror_num);
3626
3627 ret = btrfs_lookup_csums_range(csum_root,
3628 extent_logical,
3629 extent_logical +
3630 extent_len - 1,
3631 &sctx->csum_list, 1);
3632 if (ret)
3633 goto out;
3634
3635 ret = scrub_extent(sctx, map, extent_logical, extent_len,
3636 extent_physical, extent_dev, flags,
3637 generation, extent_mirror_num,
3638 extent_logical - logical + physical);
3639
3640 scrub_free_csums(sctx);
3641
3642 if (ret)
3643 goto out;
3644
3645 if (extent_logical + extent_len <
3646 key.objectid + bytes) {
3647 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3648 /*
3649 * loop until we find next data stripe
3650 * or we have finished all stripes.
3651 */
3652loop:
3653 physical += map->stripe_len;
3654 ret = get_raid56_logic_offset(physical,
3655 num, map, &logical,
3656 &stripe_logical);
3657 logical += base;
3658
3659 if (ret && physical < physical_end) {
3660 stripe_logical += base;
3661 stripe_end = stripe_logical +
3662 increment;
3663 ret = scrub_raid56_parity(sctx,
3664 map, scrub_dev, ppath,
3665 stripe_logical,
3666 stripe_end);
3667 if (ret)
3668 goto out;
3669 goto loop;
3670 }
3671 } else {
3672 physical += map->stripe_len;
3673 logical += increment;
3674 }
3675 if (logical < key.objectid + bytes) {
3676 cond_resched();
3677 goto again;
3678 }
3679
3680 if (physical >= physical_end) {
3681 stop_loop = 1;
3682 break;
3683 }
3684 }
3685next:
3686 path->slots[0]++;
3687 }
3688 btrfs_release_path(path);
3689skip:
3690 logical += increment;
3691 physical += map->stripe_len;
3692 spin_lock(&sctx->stat_lock);
3693 if (stop_loop)
3694 sctx->stat.last_physical = map->stripes[num].physical +
3695 length;
3696 else
3697 sctx->stat.last_physical = physical;
3698 spin_unlock(&sctx->stat_lock);
3699 if (stop_loop)
3700 break;
3701 }
3702out:
3703 /* push queued extents */
3704 scrub_submit(sctx);
3705 mutex_lock(&sctx->wr_lock);
3706 scrub_wr_submit(sctx);
3707 mutex_unlock(&sctx->wr_lock);
3708
3709 blk_finish_plug(&plug);
3710 btrfs_free_path(path);
3711 btrfs_free_path(ppath);
3712 return ret < 0 ? ret : 0;
3713}
3714
3715static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3716 struct btrfs_device *scrub_dev,
3717 u64 chunk_offset, u64 length,
3718 u64 dev_offset,
3719 struct btrfs_block_group_cache *cache,
3720 int is_dev_replace)
3721{
3722 struct btrfs_fs_info *fs_info = sctx->fs_info;
3723 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
3724 struct map_lookup *map;
3725 struct extent_map *em;
3726 int i;
3727 int ret = 0;
3728
3729 read_lock(&map_tree->map_tree.lock);
3730 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3731 read_unlock(&map_tree->map_tree.lock);
3732
3733 if (!em) {
3734 /*
3735 * Might have been an unused block group deleted by the cleaner
3736 * kthread or relocation.
3737 */
3738 spin_lock(&cache->lock);
3739 if (!cache->removed)
3740 ret = -EINVAL;
3741 spin_unlock(&cache->lock);
3742
3743 return ret;
3744 }
3745
3746 map = em->map_lookup;
3747 if (em->start != chunk_offset)
3748 goto out;
3749
3750 if (em->len < length)
3751 goto out;
3752
3753 for (i = 0; i < map->num_stripes; ++i) {
3754 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3755 map->stripes[i].physical == dev_offset) {
3756 ret = scrub_stripe(sctx, map, scrub_dev, i,
3757 chunk_offset, length,
3758 is_dev_replace);
3759 if (ret)
3760 goto out;
3761 }
3762 }
3763out:
3764 free_extent_map(em);
3765
3766 return ret;
3767}
3768
3769static noinline_for_stack
3770int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3771 struct btrfs_device *scrub_dev, u64 start, u64 end,
3772 int is_dev_replace)
3773{
3774 struct btrfs_dev_extent *dev_extent = NULL;
3775 struct btrfs_path *path;
3776 struct btrfs_fs_info *fs_info = sctx->fs_info;
3777 struct btrfs_root *root = fs_info->dev_root;
3778 u64 length;
3779 u64 chunk_offset;
3780 int ret = 0;
3781 int ro_set;
3782 int slot;
3783 struct extent_buffer *l;
3784 struct btrfs_key key;
3785 struct btrfs_key found_key;
3786 struct btrfs_block_group_cache *cache;
3787 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3788
3789 path = btrfs_alloc_path();
3790 if (!path)
3791 return -ENOMEM;
3792
3793 path->reada = READA_FORWARD;
3794 path->search_commit_root = 1;
3795 path->skip_locking = 1;
3796
3797 key.objectid = scrub_dev->devid;
3798 key.offset = 0ull;
3799 key.type = BTRFS_DEV_EXTENT_KEY;
3800
3801 while (1) {
3802 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3803 if (ret < 0)
3804 break;
3805 if (ret > 0) {
3806 if (path->slots[0] >=
3807 btrfs_header_nritems(path->nodes[0])) {
3808 ret = btrfs_next_leaf(root, path);
3809 if (ret < 0)
3810 break;
3811 if (ret > 0) {
3812 ret = 0;
3813 break;
3814 }
3815 } else {
3816 ret = 0;
3817 }
3818 }
3819
3820 l = path->nodes[0];
3821 slot = path->slots[0];
3822
3823 btrfs_item_key_to_cpu(l, &found_key, slot);
3824
3825 if (found_key.objectid != scrub_dev->devid)
3826 break;
3827
3828 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3829 break;
3830
3831 if (found_key.offset >= end)
3832 break;
3833
3834 if (found_key.offset < key.offset)
3835 break;
3836
3837 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3838 length = btrfs_dev_extent_length(l, dev_extent);
3839
3840 if (found_key.offset + length <= start)
3841 goto skip;
3842
3843 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3844
3845 /*
3846 * get a reference on the corresponding block group to prevent
3847 * the chunk from going away while we scrub it
3848 */
3849 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3850
3851 /* some chunks are removed but not committed to disk yet,
3852 * continue scrubbing */
3853 if (!cache)
3854 goto skip;
3855
3856 /*
3857 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3858 * to avoid deadlock caused by:
3859 * btrfs_inc_block_group_ro()
3860 * -> btrfs_wait_for_commit()
3861 * -> btrfs_commit_transaction()
3862 * -> btrfs_scrub_pause()
3863 */
3864 scrub_pause_on(fs_info);
3865 ret = btrfs_inc_block_group_ro(fs_info, cache);
3866 if (!ret && is_dev_replace) {
3867 /*
3868 * If we are doing a device replace wait for any tasks
3869 * that started dellaloc right before we set the block
3870 * group to RO mode, as they might have just allocated
3871 * an extent from it or decided they could do a nocow
3872 * write. And if any such tasks did that, wait for their
3873 * ordered extents to complete and then commit the
3874 * current transaction, so that we can later see the new
3875 * extent items in the extent tree - the ordered extents
3876 * create delayed data references (for cow writes) when
3877 * they complete, which will be run and insert the
3878 * corresponding extent items into the extent tree when
3879 * we commit the transaction they used when running
3880 * inode.c:btrfs_finish_ordered_io(). We later use
3881 * the commit root of the extent tree to find extents
3882 * to copy from the srcdev into the tgtdev, and we don't
3883 * want to miss any new extents.
3884 */
3885 btrfs_wait_block_group_reservations(cache);
3886 btrfs_wait_nocow_writers(cache);
3887 ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
3888 cache->key.objectid,
3889 cache->key.offset);
3890 if (ret > 0) {
3891 struct btrfs_trans_handle *trans;
3892
3893 trans = btrfs_join_transaction(root);
3894 if (IS_ERR(trans))
3895 ret = PTR_ERR(trans);
3896 else
3897 ret = btrfs_commit_transaction(trans);
3898 if (ret) {
3899 scrub_pause_off(fs_info);
3900 btrfs_put_block_group(cache);
3901 break;
3902 }
3903 }
3904 }
3905 scrub_pause_off(fs_info);
3906
3907 if (ret == 0) {
3908 ro_set = 1;
3909 } else if (ret == -ENOSPC) {
3910 /*
3911 * btrfs_inc_block_group_ro return -ENOSPC when it
3912 * failed in creating new chunk for metadata.
3913 * It is not a problem for scrub/replace, because
3914 * metadata are always cowed, and our scrub paused
3915 * commit_transactions.
3916 */
3917 ro_set = 0;
3918 } else {
3919 btrfs_warn(fs_info,
3920 "failed setting block group ro: %d", ret);
3921 btrfs_put_block_group(cache);
3922 break;
3923 }
3924
3925 btrfs_dev_replace_write_lock(&fs_info->dev_replace);
3926 dev_replace->cursor_right = found_key.offset + length;
3927 dev_replace->cursor_left = found_key.offset;
3928 dev_replace->item_needs_writeback = 1;
3929 btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
3930 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3931 found_key.offset, cache, is_dev_replace);
3932
3933 /*
3934 * flush, submit all pending read and write bios, afterwards
3935 * wait for them.
3936 * Note that in the dev replace case, a read request causes
3937 * write requests that are submitted in the read completion
3938 * worker. Therefore in the current situation, it is required
3939 * that all write requests are flushed, so that all read and
3940 * write requests are really completed when bios_in_flight
3941 * changes to 0.
3942 */
3943 sctx->flush_all_writes = true;
3944 scrub_submit(sctx);
3945 mutex_lock(&sctx->wr_lock);
3946 scrub_wr_submit(sctx);
3947 mutex_unlock(&sctx->wr_lock);
3948
3949 wait_event(sctx->list_wait,
3950 atomic_read(&sctx->bios_in_flight) == 0);
3951
3952 scrub_pause_on(fs_info);
3953
3954 /*
3955 * must be called before we decrease @scrub_paused.
3956 * make sure we don't block transaction commit while
3957 * we are waiting pending workers finished.
3958 */
3959 wait_event(sctx->list_wait,
3960 atomic_read(&sctx->workers_pending) == 0);
3961 sctx->flush_all_writes = false;
3962
3963 scrub_pause_off(fs_info);
3964
3965 btrfs_dev_replace_write_lock(&fs_info->dev_replace);
3966 dev_replace->cursor_left = dev_replace->cursor_right;
3967 dev_replace->item_needs_writeback = 1;
3968 btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
3969
3970 if (ro_set)
3971 btrfs_dec_block_group_ro(cache);
3972
3973 /*
3974 * We might have prevented the cleaner kthread from deleting
3975 * this block group if it was already unused because we raced
3976 * and set it to RO mode first. So add it back to the unused
3977 * list, otherwise it might not ever be deleted unless a manual
3978 * balance is triggered or it becomes used and unused again.
3979 */
3980 spin_lock(&cache->lock);
3981 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3982 btrfs_block_group_used(&cache->item) == 0) {
3983 spin_unlock(&cache->lock);
3984 spin_lock(&fs_info->unused_bgs_lock);
3985 if (list_empty(&cache->bg_list)) {
3986 btrfs_get_block_group(cache);
3987 list_add_tail(&cache->bg_list,
3988 &fs_info->unused_bgs);
3989 }
3990 spin_unlock(&fs_info->unused_bgs_lock);
3991 } else {
3992 spin_unlock(&cache->lock);
3993 }
3994
3995 btrfs_put_block_group(cache);
3996 if (ret)
3997 break;
3998 if (is_dev_replace &&
3999 atomic64_read(&dev_replace->num_write_errors) > 0) {
4000 ret = -EIO;
4001 break;
4002 }
4003 if (sctx->stat.malloc_errors > 0) {
4004 ret = -ENOMEM;
4005 break;
4006 }
4007skip:
4008 key.offset = found_key.offset + length;
4009 btrfs_release_path(path);
4010 }
4011
4012 btrfs_free_path(path);
4013
4014 return ret;
4015}
4016
4017static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
4018 struct btrfs_device *scrub_dev)
4019{
4020 int i;
4021 u64 bytenr;
4022 u64 gen;
4023 int ret;
4024 struct btrfs_fs_info *fs_info = sctx->fs_info;
4025
4026 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
4027 return -EIO;
4028
4029 /* Seed devices of a new filesystem has their own generation. */
4030 if (scrub_dev->fs_devices != fs_info->fs_devices)
4031 gen = scrub_dev->generation;
4032 else
4033 gen = fs_info->last_trans_committed;
4034
4035 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
4036 bytenr = btrfs_sb_offset(i);
4037 if (bytenr + BTRFS_SUPER_INFO_SIZE >
4038 scrub_dev->commit_total_bytes)
4039 break;
4040
4041 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
4042 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
4043 NULL, 1, bytenr);
4044 if (ret)
4045 return ret;
4046 }
4047 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
4048
4049 return 0;
4050}
4051
4052/*
4053 * get a reference count on fs_info->scrub_workers. start worker if necessary
4054 */
4055static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
4056 int is_dev_replace)
4057{
4058 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
4059 int max_active = fs_info->thread_pool_size;
4060
4061 if (fs_info->scrub_workers_refcnt == 0) {
4062 fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
4063 flags, is_dev_replace ? 1 : max_active, 4);
4064 if (!fs_info->scrub_workers)
4065 goto fail_scrub_workers;
4066
4067 fs_info->scrub_wr_completion_workers =
4068 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
4069 max_active, 2);
4070 if (!fs_info->scrub_wr_completion_workers)
4071 goto fail_scrub_wr_completion_workers;
4072
4073 fs_info->scrub_nocow_workers =
4074 btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
4075 if (!fs_info->scrub_nocow_workers)
4076 goto fail_scrub_nocow_workers;
4077 fs_info->scrub_parity_workers =
4078 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
4079 max_active, 2);
4080 if (!fs_info->scrub_parity_workers)
4081 goto fail_scrub_parity_workers;
4082 }
4083 ++fs_info->scrub_workers_refcnt;
4084 return 0;
4085
4086fail_scrub_parity_workers:
4087 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
4088fail_scrub_nocow_workers:
4089 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
4090fail_scrub_wr_completion_workers:
4091 btrfs_destroy_workqueue(fs_info->scrub_workers);
4092fail_scrub_workers:
4093 return -ENOMEM;
4094}
4095
4096static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
4097{
4098 if (--fs_info->scrub_workers_refcnt == 0) {
4099 btrfs_destroy_workqueue(fs_info->scrub_workers);
4100 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
4101 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
4102 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
4103 }
4104 WARN_ON(fs_info->scrub_workers_refcnt < 0);
4105}
4106
4107int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
4108 u64 end, struct btrfs_scrub_progress *progress,
4109 int readonly, int is_dev_replace)
4110{
4111 struct scrub_ctx *sctx;
4112 int ret;
4113 struct btrfs_device *dev;
4114 struct rcu_string *name;
4115
4116 if (btrfs_fs_closing(fs_info))
4117 return -EINVAL;
4118
4119 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
4120 /*
4121 * in this case scrub is unable to calculate the checksum
4122 * the way scrub is implemented. Do not handle this
4123 * situation at all because it won't ever happen.
4124 */
4125 btrfs_err(fs_info,
4126 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
4127 fs_info->nodesize,
4128 BTRFS_STRIPE_LEN);
4129 return -EINVAL;
4130 }
4131
4132 if (fs_info->sectorsize != PAGE_SIZE) {
4133 /* not supported for data w/o checksums */
4134 btrfs_err_rl(fs_info,
4135 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
4136 fs_info->sectorsize, PAGE_SIZE);
4137 return -EINVAL;
4138 }
4139
4140 if (fs_info->nodesize >
4141 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
4142 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
4143 /*
4144 * would exhaust the array bounds of pagev member in
4145 * struct scrub_block
4146 */
4147 btrfs_err(fs_info,
4148 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
4149 fs_info->nodesize,
4150 SCRUB_MAX_PAGES_PER_BLOCK,
4151 fs_info->sectorsize,
4152 SCRUB_MAX_PAGES_PER_BLOCK);
4153 return -EINVAL;
4154 }
4155
4156
4157 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4158 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
4159 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
4160 !is_dev_replace)) {
4161 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4162 return -ENODEV;
4163 }
4164
4165 if (!is_dev_replace && !readonly &&
4166 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
4167 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4168 rcu_read_lock();
4169 name = rcu_dereference(dev->name);
4170 btrfs_err(fs_info, "scrub: device %s is not writable",
4171 name->str);
4172 rcu_read_unlock();
4173 return -EROFS;
4174 }
4175
4176 mutex_lock(&fs_info->scrub_lock);
4177 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4178 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
4179 mutex_unlock(&fs_info->scrub_lock);
4180 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4181 return -EIO;
4182 }
4183
4184 btrfs_dev_replace_read_lock(&fs_info->dev_replace);
4185 if (dev->scrub_ctx ||
4186 (!is_dev_replace &&
4187 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
4188 btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
4189 mutex_unlock(&fs_info->scrub_lock);
4190 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4191 return -EINPROGRESS;
4192 }
4193 btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
4194
4195 ret = scrub_workers_get(fs_info, is_dev_replace);
4196 if (ret) {
4197 mutex_unlock(&fs_info->scrub_lock);
4198 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4199 return ret;
4200 }
4201
4202 sctx = scrub_setup_ctx(dev, is_dev_replace);
4203 if (IS_ERR(sctx)) {
4204 mutex_unlock(&fs_info->scrub_lock);
4205 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4206 scrub_workers_put(fs_info);
4207 return PTR_ERR(sctx);
4208 }
4209 sctx->readonly = readonly;
4210 dev->scrub_ctx = sctx;
4211 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4212
4213 /*
4214 * checking @scrub_pause_req here, we can avoid
4215 * race between committing transaction and scrubbing.
4216 */
4217 __scrub_blocked_if_needed(fs_info);
4218 atomic_inc(&fs_info->scrubs_running);
4219 mutex_unlock(&fs_info->scrub_lock);
4220
4221 if (!is_dev_replace) {
4222 /*
4223 * by holding device list mutex, we can
4224 * kick off writing super in log tree sync.
4225 */
4226 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4227 ret = scrub_supers(sctx, dev);
4228 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4229 }
4230
4231 if (!ret)
4232 ret = scrub_enumerate_chunks(sctx, dev, start, end,
4233 is_dev_replace);
4234
4235 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
4236 atomic_dec(&fs_info->scrubs_running);
4237 wake_up(&fs_info->scrub_pause_wait);
4238
4239 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
4240
4241 if (progress)
4242 memcpy(progress, &sctx->stat, sizeof(*progress));
4243
4244 mutex_lock(&fs_info->scrub_lock);
4245 dev->scrub_ctx = NULL;
4246 scrub_workers_put(fs_info);
4247 mutex_unlock(&fs_info->scrub_lock);
4248
4249 scrub_put_ctx(sctx);
4250
4251 return ret;
4252}
4253
4254void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
4255{
4256 mutex_lock(&fs_info->scrub_lock);
4257 atomic_inc(&fs_info->scrub_pause_req);
4258 while (atomic_read(&fs_info->scrubs_paused) !=
4259 atomic_read(&fs_info->scrubs_running)) {
4260 mutex_unlock(&fs_info->scrub_lock);
4261 wait_event(fs_info->scrub_pause_wait,
4262 atomic_read(&fs_info->scrubs_paused) ==
4263 atomic_read(&fs_info->scrubs_running));
4264 mutex_lock(&fs_info->scrub_lock);
4265 }
4266 mutex_unlock(&fs_info->scrub_lock);
4267}
4268
4269void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
4270{
4271 atomic_dec(&fs_info->scrub_pause_req);
4272 wake_up(&fs_info->scrub_pause_wait);
4273}
4274
4275int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
4276{
4277 mutex_lock(&fs_info->scrub_lock);
4278 if (!atomic_read(&fs_info->scrubs_running)) {
4279 mutex_unlock(&fs_info->scrub_lock);
4280 return -ENOTCONN;
4281 }
4282
4283 atomic_inc(&fs_info->scrub_cancel_req);
4284 while (atomic_read(&fs_info->scrubs_running)) {
4285 mutex_unlock(&fs_info->scrub_lock);
4286 wait_event(fs_info->scrub_pause_wait,
4287 atomic_read(&fs_info->scrubs_running) == 0);
4288 mutex_lock(&fs_info->scrub_lock);
4289 }
4290 atomic_dec(&fs_info->scrub_cancel_req);
4291 mutex_unlock(&fs_info->scrub_lock);
4292
4293 return 0;
4294}
4295
4296int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
4297 struct btrfs_device *dev)
4298{
4299 struct scrub_ctx *sctx;
4300
4301 mutex_lock(&fs_info->scrub_lock);
4302 sctx = dev->scrub_ctx;
4303 if (!sctx) {
4304 mutex_unlock(&fs_info->scrub_lock);
4305 return -ENOTCONN;
4306 }
4307 atomic_inc(&sctx->cancel_req);
4308 while (dev->scrub_ctx) {
4309 mutex_unlock(&fs_info->scrub_lock);
4310 wait_event(fs_info->scrub_pause_wait,
4311 dev->scrub_ctx == NULL);
4312 mutex_lock(&fs_info->scrub_lock);
4313 }
4314 mutex_unlock(&fs_info->scrub_lock);
4315
4316 return 0;
4317}
4318
4319int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4320 struct btrfs_scrub_progress *progress)
4321{
4322 struct btrfs_device *dev;
4323 struct scrub_ctx *sctx = NULL;
4324
4325 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4326 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
4327 if (dev)
4328 sctx = dev->scrub_ctx;
4329 if (sctx)
4330 memcpy(progress, &sctx->stat, sizeof(*progress));
4331 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4332
4333 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4334}
4335
4336static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4337 u64 extent_logical, u64 extent_len,
4338 u64 *extent_physical,
4339 struct btrfs_device **extent_dev,
4340 int *extent_mirror_num)
4341{
4342 u64 mapped_length;
4343 struct btrfs_bio *bbio = NULL;
4344 int ret;
4345
4346 mapped_length = extent_len;
4347 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4348 &mapped_length, &bbio, 0);
4349 if (ret || !bbio || mapped_length < extent_len ||
4350 !bbio->stripes[0].dev->bdev) {
4351 btrfs_put_bbio(bbio);
4352 return;
4353 }
4354
4355 *extent_physical = bbio->stripes[0].physical;
4356 *extent_mirror_num = bbio->mirror_num;
4357 *extent_dev = bbio->stripes[0].dev;
4358 btrfs_put_bbio(bbio);
4359}
4360
4361static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
4362 int mirror_num, u64 physical_for_dev_replace)
4363{
4364 struct scrub_copy_nocow_ctx *nocow_ctx;
4365 struct btrfs_fs_info *fs_info = sctx->fs_info;
4366
4367 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
4368 if (!nocow_ctx) {
4369 spin_lock(&sctx->stat_lock);
4370 sctx->stat.malloc_errors++;
4371 spin_unlock(&sctx->stat_lock);
4372 return -ENOMEM;
4373 }
4374
4375 scrub_pending_trans_workers_inc(sctx);
4376
4377 nocow_ctx->sctx = sctx;
4378 nocow_ctx->logical = logical;
4379 nocow_ctx->len = len;
4380 nocow_ctx->mirror_num = mirror_num;
4381 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
4382 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
4383 copy_nocow_pages_worker, NULL, NULL);
4384 INIT_LIST_HEAD(&nocow_ctx->inodes);
4385 btrfs_queue_work(fs_info->scrub_nocow_workers,
4386 &nocow_ctx->work);
4387
4388 return 0;
4389}
4390
4391static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
4392{
4393 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
4394 struct scrub_nocow_inode *nocow_inode;
4395
4396 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
4397 if (!nocow_inode)
4398 return -ENOMEM;
4399 nocow_inode->inum = inum;
4400 nocow_inode->offset = offset;
4401 nocow_inode->root = root;
4402 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
4403 return 0;
4404}
4405
4406#define COPY_COMPLETE 1
4407
4408static void copy_nocow_pages_worker(struct btrfs_work *work)
4409{
4410 struct scrub_copy_nocow_ctx *nocow_ctx =
4411 container_of(work, struct scrub_copy_nocow_ctx, work);
4412 struct scrub_ctx *sctx = nocow_ctx->sctx;
4413 struct btrfs_fs_info *fs_info = sctx->fs_info;
4414 struct btrfs_root *root = fs_info->extent_root;
4415 u64 logical = nocow_ctx->logical;
4416 u64 len = nocow_ctx->len;
4417 int mirror_num = nocow_ctx->mirror_num;
4418 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4419 int ret;
4420 struct btrfs_trans_handle *trans = NULL;
4421 struct btrfs_path *path;
4422 int not_written = 0;
4423
4424 path = btrfs_alloc_path();
4425 if (!path) {
4426 spin_lock(&sctx->stat_lock);
4427 sctx->stat.malloc_errors++;
4428 spin_unlock(&sctx->stat_lock);
4429 not_written = 1;
4430 goto out;
4431 }
4432
4433 trans = btrfs_join_transaction(root);
4434 if (IS_ERR(trans)) {
4435 not_written = 1;
4436 goto out;
4437 }
4438
4439 ret = iterate_inodes_from_logical(logical, fs_info, path,
4440 record_inode_for_nocow, nocow_ctx, false);
4441 if (ret != 0 && ret != -ENOENT) {
4442 btrfs_warn(fs_info,
4443 "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d",
4444 logical, physical_for_dev_replace, len, mirror_num,
4445 ret);
4446 not_written = 1;
4447 goto out;
4448 }
4449
4450 btrfs_end_transaction(trans);
4451 trans = NULL;
4452 while (!list_empty(&nocow_ctx->inodes)) {
4453 struct scrub_nocow_inode *entry;
4454 entry = list_first_entry(&nocow_ctx->inodes,
4455 struct scrub_nocow_inode,
4456 list);
4457 list_del_init(&entry->list);
4458 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4459 entry->root, nocow_ctx);
4460 kfree(entry);
4461 if (ret == COPY_COMPLETE) {
4462 ret = 0;
4463 break;
4464 } else if (ret) {
4465 break;
4466 }
4467 }
4468out:
4469 while (!list_empty(&nocow_ctx->inodes)) {
4470 struct scrub_nocow_inode *entry;
4471 entry = list_first_entry(&nocow_ctx->inodes,
4472 struct scrub_nocow_inode,
4473 list);
4474 list_del_init(&entry->list);
4475 kfree(entry);
4476 }
4477 if (trans && !IS_ERR(trans))
4478 btrfs_end_transaction(trans);
4479 if (not_written)
4480 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4481 num_uncorrectable_read_errors);
4482
4483 btrfs_free_path(path);
4484 kfree(nocow_ctx);
4485
4486 scrub_pending_trans_workers_dec(sctx);
4487}
4488
4489static int check_extent_to_block(struct btrfs_inode *inode, u64 start, u64 len,
4490 u64 logical)
4491{
4492 struct extent_state *cached_state = NULL;
4493 struct btrfs_ordered_extent *ordered;
4494 struct extent_io_tree *io_tree;
4495 struct extent_map *em;
4496 u64 lockstart = start, lockend = start + len - 1;
4497 int ret = 0;
4498
4499 io_tree = &inode->io_tree;
4500
4501 lock_extent_bits(io_tree, lockstart, lockend, &cached_state);
4502 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4503 if (ordered) {
4504 btrfs_put_ordered_extent(ordered);
4505 ret = 1;
4506 goto out_unlock;
4507 }
4508
4509 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4510 if (IS_ERR(em)) {
4511 ret = PTR_ERR(em);
4512 goto out_unlock;
4513 }
4514
4515 /*
4516 * This extent does not actually cover the logical extent anymore,
4517 * move on to the next inode.
4518 */
4519 if (em->block_start > logical ||
4520 em->block_start + em->block_len < logical + len ||
4521 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4522 free_extent_map(em);
4523 ret = 1;
4524 goto out_unlock;
4525 }
4526 free_extent_map(em);
4527
4528out_unlock:
4529 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state);
4530 return ret;
4531}
4532
4533static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4534 struct scrub_copy_nocow_ctx *nocow_ctx)
4535{
4536 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info;
4537 struct btrfs_key key;
4538 struct inode *inode;
4539 struct page *page;
4540 struct btrfs_root *local_root;
4541 struct extent_io_tree *io_tree;
4542 u64 physical_for_dev_replace;
4543 u64 nocow_ctx_logical;
4544 u64 len = nocow_ctx->len;
4545 unsigned long index;
4546 int srcu_index;
4547 int ret = 0;
4548 int err = 0;
4549
4550 key.objectid = root;
4551 key.type = BTRFS_ROOT_ITEM_KEY;
4552 key.offset = (u64)-1;
4553
4554 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4555
4556 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4557 if (IS_ERR(local_root)) {
4558 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4559 return PTR_ERR(local_root);
4560 }
4561
4562 key.type = BTRFS_INODE_ITEM_KEY;
4563 key.objectid = inum;
4564 key.offset = 0;
4565 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4566 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4567 if (IS_ERR(inode))
4568 return PTR_ERR(inode);
4569
4570 /* Avoid truncate/dio/punch hole.. */
4571 inode_lock(inode);
4572 inode_dio_wait(inode);
4573
4574 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4575 io_tree = &BTRFS_I(inode)->io_tree;
4576 nocow_ctx_logical = nocow_ctx->logical;
4577
4578 ret = check_extent_to_block(BTRFS_I(inode), offset, len,
4579 nocow_ctx_logical);
4580 if (ret) {
4581 ret = ret > 0 ? 0 : ret;
4582 goto out;
4583 }
4584
4585 while (len >= PAGE_SIZE) {
4586 index = offset >> PAGE_SHIFT;
4587again:
4588 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4589 if (!page) {
4590 btrfs_err(fs_info, "find_or_create_page() failed");
4591 ret = -ENOMEM;
4592 goto out;
4593 }
4594
4595 if (PageUptodate(page)) {
4596 if (PageDirty(page))
4597 goto next_page;
4598 } else {
4599 ClearPageError(page);
4600 err = extent_read_full_page(io_tree, page,
4601 btrfs_get_extent,
4602 nocow_ctx->mirror_num);
4603 if (err) {
4604 ret = err;
4605 goto next_page;
4606 }
4607
4608 lock_page(page);
4609 /*
4610 * If the page has been remove from the page cache,
4611 * the data on it is meaningless, because it may be
4612 * old one, the new data may be written into the new
4613 * page in the page cache.
4614 */
4615 if (page->mapping != inode->i_mapping) {
4616 unlock_page(page);
4617 put_page(page);
4618 goto again;
4619 }
4620 if (!PageUptodate(page)) {
4621 ret = -EIO;
4622 goto next_page;
4623 }
4624 }
4625
4626 ret = check_extent_to_block(BTRFS_I(inode), offset, len,
4627 nocow_ctx_logical);
4628 if (ret) {
4629 ret = ret > 0 ? 0 : ret;
4630 goto next_page;
4631 }
4632
4633 err = write_page_nocow(nocow_ctx->sctx,
4634 physical_for_dev_replace, page);
4635 if (err)
4636 ret = err;
4637next_page:
4638 unlock_page(page);
4639 put_page(page);
4640
4641 if (ret)
4642 break;
4643
4644 offset += PAGE_SIZE;
4645 physical_for_dev_replace += PAGE_SIZE;
4646 nocow_ctx_logical += PAGE_SIZE;
4647 len -= PAGE_SIZE;
4648 }
4649 ret = COPY_COMPLETE;
4650out:
4651 inode_unlock(inode);
4652 iput(inode);
4653 return ret;
4654}
4655
4656static int write_page_nocow(struct scrub_ctx *sctx,
4657 u64 physical_for_dev_replace, struct page *page)
4658{
4659 struct bio *bio;
4660 struct btrfs_device *dev;
4661
4662 dev = sctx->wr_tgtdev;
4663 if (!dev)
4664 return -EIO;
4665 if (!dev->bdev) {
4666 btrfs_warn_rl(dev->fs_info,
4667 "scrub write_page_nocow(bdev == NULL) is unexpected");
4668 return -EIO;
4669 }
4670 bio = btrfs_io_bio_alloc(1);
4671 bio->bi_iter.bi_size = 0;
4672 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4673 bio_set_dev(bio, dev->bdev);
4674 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
4675 /* bio_add_page won't fail on a freshly allocated bio */
4676 bio_add_page(bio, page, PAGE_SIZE, 0);
4677
4678 if (btrfsic_submit_bio_wait(bio)) {
4679 bio_put(bio);
4680 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4681 return -EIO;
4682 }
4683
4684 bio_put(bio);
4685 return 0;
4686}
1/*
2 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/blkdev.h>
20#include <linux/ratelimit.h>
21#include "ctree.h"
22#include "volumes.h"
23#include "disk-io.h"
24#include "ordered-data.h"
25#include "transaction.h"
26#include "backref.h"
27#include "extent_io.h"
28#include "dev-replace.h"
29#include "check-integrity.h"
30#include "rcu-string.h"
31#include "raid56.h"
32
33/*
34 * This is only the first step towards a full-features scrub. It reads all
35 * extent and super block and verifies the checksums. In case a bad checksum
36 * is found or the extent cannot be read, good data will be written back if
37 * any can be found.
38 *
39 * Future enhancements:
40 * - In case an unrepairable extent is encountered, track which files are
41 * affected and report them
42 * - track and record media errors, throw out bad devices
43 * - add a mode to also read unallocated space
44 */
45
46struct scrub_block;
47struct scrub_ctx;
48
49/*
50 * the following three values only influence the performance.
51 * The last one configures the number of parallel and outstanding I/O
52 * operations. The first two values configure an upper limit for the number
53 * of (dynamically allocated) pages that are added to a bio.
54 */
55#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
56#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
57#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
58
59/*
60 * the following value times PAGE_SIZE needs to be large enough to match the
61 * largest node/leaf/sector size that shall be supported.
62 * Values larger than BTRFS_STRIPE_LEN are not supported.
63 */
64#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
65
66struct scrub_recover {
67 atomic_t refs;
68 struct btrfs_bio *bbio;
69 u64 map_length;
70};
71
72struct scrub_page {
73 struct scrub_block *sblock;
74 struct page *page;
75 struct btrfs_device *dev;
76 struct list_head list;
77 u64 flags; /* extent flags */
78 u64 generation;
79 u64 logical;
80 u64 physical;
81 u64 physical_for_dev_replace;
82 atomic_t refs;
83 struct {
84 unsigned int mirror_num:8;
85 unsigned int have_csum:1;
86 unsigned int io_error:1;
87 };
88 u8 csum[BTRFS_CSUM_SIZE];
89
90 struct scrub_recover *recover;
91};
92
93struct scrub_bio {
94 int index;
95 struct scrub_ctx *sctx;
96 struct btrfs_device *dev;
97 struct bio *bio;
98 int err;
99 u64 logical;
100 u64 physical;
101#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
102 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
103#else
104 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
105#endif
106 int page_count;
107 int next_free;
108 struct btrfs_work work;
109};
110
111struct scrub_block {
112 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
113 int page_count;
114 atomic_t outstanding_pages;
115 atomic_t refs; /* free mem on transition to zero */
116 struct scrub_ctx *sctx;
117 struct scrub_parity *sparity;
118 struct {
119 unsigned int header_error:1;
120 unsigned int checksum_error:1;
121 unsigned int no_io_error_seen:1;
122 unsigned int generation_error:1; /* also sets header_error */
123
124 /* The following is for the data used to check parity */
125 /* It is for the data with checksum */
126 unsigned int data_corrected:1;
127 };
128 struct btrfs_work work;
129};
130
131/* Used for the chunks with parity stripe such RAID5/6 */
132struct scrub_parity {
133 struct scrub_ctx *sctx;
134
135 struct btrfs_device *scrub_dev;
136
137 u64 logic_start;
138
139 u64 logic_end;
140
141 int nsectors;
142
143 int stripe_len;
144
145 atomic_t refs;
146
147 struct list_head spages;
148
149 /* Work of parity check and repair */
150 struct btrfs_work work;
151
152 /* Mark the parity blocks which have data */
153 unsigned long *dbitmap;
154
155 /*
156 * Mark the parity blocks which have data, but errors happen when
157 * read data or check data
158 */
159 unsigned long *ebitmap;
160
161 unsigned long bitmap[0];
162};
163
164struct scrub_wr_ctx {
165 struct scrub_bio *wr_curr_bio;
166 struct btrfs_device *tgtdev;
167 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
168 atomic_t flush_all_writes;
169 struct mutex wr_lock;
170};
171
172struct scrub_ctx {
173 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
174 struct btrfs_fs_info *fs_info;
175 int first_free;
176 int curr;
177 atomic_t bios_in_flight;
178 atomic_t workers_pending;
179 spinlock_t list_lock;
180 wait_queue_head_t list_wait;
181 u16 csum_size;
182 struct list_head csum_list;
183 atomic_t cancel_req;
184 int readonly;
185 int pages_per_rd_bio;
186 u32 sectorsize;
187 u32 nodesize;
188
189 int is_dev_replace;
190 struct scrub_wr_ctx wr_ctx;
191
192 /*
193 * statistics
194 */
195 struct btrfs_scrub_progress stat;
196 spinlock_t stat_lock;
197
198 /*
199 * Use a ref counter to avoid use-after-free issues. Scrub workers
200 * decrement bios_in_flight and workers_pending and then do a wakeup
201 * on the list_wait wait queue. We must ensure the main scrub task
202 * doesn't free the scrub context before or while the workers are
203 * doing the wakeup() call.
204 */
205 atomic_t refs;
206};
207
208struct scrub_fixup_nodatasum {
209 struct scrub_ctx *sctx;
210 struct btrfs_device *dev;
211 u64 logical;
212 struct btrfs_root *root;
213 struct btrfs_work work;
214 int mirror_num;
215};
216
217struct scrub_nocow_inode {
218 u64 inum;
219 u64 offset;
220 u64 root;
221 struct list_head list;
222};
223
224struct scrub_copy_nocow_ctx {
225 struct scrub_ctx *sctx;
226 u64 logical;
227 u64 len;
228 int mirror_num;
229 u64 physical_for_dev_replace;
230 struct list_head inodes;
231 struct btrfs_work work;
232};
233
234struct scrub_warning {
235 struct btrfs_path *path;
236 u64 extent_item_size;
237 const char *errstr;
238 sector_t sector;
239 u64 logical;
240 struct btrfs_device *dev;
241};
242
243static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
244static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
245static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
246static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
247static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
248static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
249 struct scrub_block *sblocks_for_recheck);
250static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
251 struct scrub_block *sblock,
252 int retry_failed_mirror);
253static void scrub_recheck_block_checksum(struct scrub_block *sblock);
254static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
255 struct scrub_block *sblock_good);
256static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
257 struct scrub_block *sblock_good,
258 int page_num, int force_write);
259static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
260static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
261 int page_num);
262static int scrub_checksum_data(struct scrub_block *sblock);
263static int scrub_checksum_tree_block(struct scrub_block *sblock);
264static int scrub_checksum_super(struct scrub_block *sblock);
265static void scrub_block_get(struct scrub_block *sblock);
266static void scrub_block_put(struct scrub_block *sblock);
267static void scrub_page_get(struct scrub_page *spage);
268static void scrub_page_put(struct scrub_page *spage);
269static void scrub_parity_get(struct scrub_parity *sparity);
270static void scrub_parity_put(struct scrub_parity *sparity);
271static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
272 struct scrub_page *spage);
273static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
274 u64 physical, struct btrfs_device *dev, u64 flags,
275 u64 gen, int mirror_num, u8 *csum, int force,
276 u64 physical_for_dev_replace);
277static void scrub_bio_end_io(struct bio *bio);
278static void scrub_bio_end_io_worker(struct btrfs_work *work);
279static void scrub_block_complete(struct scrub_block *sblock);
280static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
281 u64 extent_logical, u64 extent_len,
282 u64 *extent_physical,
283 struct btrfs_device **extent_dev,
284 int *extent_mirror_num);
285static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
286 struct scrub_wr_ctx *wr_ctx,
287 struct btrfs_fs_info *fs_info,
288 struct btrfs_device *dev,
289 int is_dev_replace);
290static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
291static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
292 struct scrub_page *spage);
293static void scrub_wr_submit(struct scrub_ctx *sctx);
294static void scrub_wr_bio_end_io(struct bio *bio);
295static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
296static int write_page_nocow(struct scrub_ctx *sctx,
297 u64 physical_for_dev_replace, struct page *page);
298static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
299 struct scrub_copy_nocow_ctx *ctx);
300static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
301 int mirror_num, u64 physical_for_dev_replace);
302static void copy_nocow_pages_worker(struct btrfs_work *work);
303static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
304static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
305static void scrub_put_ctx(struct scrub_ctx *sctx);
306
307
308static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
309{
310 atomic_inc(&sctx->refs);
311 atomic_inc(&sctx->bios_in_flight);
312}
313
314static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
315{
316 atomic_dec(&sctx->bios_in_flight);
317 wake_up(&sctx->list_wait);
318 scrub_put_ctx(sctx);
319}
320
321static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
322{
323 while (atomic_read(&fs_info->scrub_pause_req)) {
324 mutex_unlock(&fs_info->scrub_lock);
325 wait_event(fs_info->scrub_pause_wait,
326 atomic_read(&fs_info->scrub_pause_req) == 0);
327 mutex_lock(&fs_info->scrub_lock);
328 }
329}
330
331static void scrub_pause_on(struct btrfs_fs_info *fs_info)
332{
333 atomic_inc(&fs_info->scrubs_paused);
334 wake_up(&fs_info->scrub_pause_wait);
335}
336
337static void scrub_pause_off(struct btrfs_fs_info *fs_info)
338{
339 mutex_lock(&fs_info->scrub_lock);
340 __scrub_blocked_if_needed(fs_info);
341 atomic_dec(&fs_info->scrubs_paused);
342 mutex_unlock(&fs_info->scrub_lock);
343
344 wake_up(&fs_info->scrub_pause_wait);
345}
346
347static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
348{
349 scrub_pause_on(fs_info);
350 scrub_pause_off(fs_info);
351}
352
353/*
354 * used for workers that require transaction commits (i.e., for the
355 * NOCOW case)
356 */
357static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
358{
359 struct btrfs_fs_info *fs_info = sctx->fs_info;
360
361 atomic_inc(&sctx->refs);
362 /*
363 * increment scrubs_running to prevent cancel requests from
364 * completing as long as a worker is running. we must also
365 * increment scrubs_paused to prevent deadlocking on pause
366 * requests used for transactions commits (as the worker uses a
367 * transaction context). it is safe to regard the worker
368 * as paused for all matters practical. effectively, we only
369 * avoid cancellation requests from completing.
370 */
371 mutex_lock(&fs_info->scrub_lock);
372 atomic_inc(&fs_info->scrubs_running);
373 atomic_inc(&fs_info->scrubs_paused);
374 mutex_unlock(&fs_info->scrub_lock);
375
376 /*
377 * check if @scrubs_running=@scrubs_paused condition
378 * inside wait_event() is not an atomic operation.
379 * which means we may inc/dec @scrub_running/paused
380 * at any time. Let's wake up @scrub_pause_wait as
381 * much as we can to let commit transaction blocked less.
382 */
383 wake_up(&fs_info->scrub_pause_wait);
384
385 atomic_inc(&sctx->workers_pending);
386}
387
388/* used for workers that require transaction commits */
389static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
390{
391 struct btrfs_fs_info *fs_info = sctx->fs_info;
392
393 /*
394 * see scrub_pending_trans_workers_inc() why we're pretending
395 * to be paused in the scrub counters
396 */
397 mutex_lock(&fs_info->scrub_lock);
398 atomic_dec(&fs_info->scrubs_running);
399 atomic_dec(&fs_info->scrubs_paused);
400 mutex_unlock(&fs_info->scrub_lock);
401 atomic_dec(&sctx->workers_pending);
402 wake_up(&fs_info->scrub_pause_wait);
403 wake_up(&sctx->list_wait);
404 scrub_put_ctx(sctx);
405}
406
407static void scrub_free_csums(struct scrub_ctx *sctx)
408{
409 while (!list_empty(&sctx->csum_list)) {
410 struct btrfs_ordered_sum *sum;
411 sum = list_first_entry(&sctx->csum_list,
412 struct btrfs_ordered_sum, list);
413 list_del(&sum->list);
414 kfree(sum);
415 }
416}
417
418static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
419{
420 int i;
421
422 if (!sctx)
423 return;
424
425 scrub_free_wr_ctx(&sctx->wr_ctx);
426
427 /* this can happen when scrub is cancelled */
428 if (sctx->curr != -1) {
429 struct scrub_bio *sbio = sctx->bios[sctx->curr];
430
431 for (i = 0; i < sbio->page_count; i++) {
432 WARN_ON(!sbio->pagev[i]->page);
433 scrub_block_put(sbio->pagev[i]->sblock);
434 }
435 bio_put(sbio->bio);
436 }
437
438 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
439 struct scrub_bio *sbio = sctx->bios[i];
440
441 if (!sbio)
442 break;
443 kfree(sbio);
444 }
445
446 scrub_free_csums(sctx);
447 kfree(sctx);
448}
449
450static void scrub_put_ctx(struct scrub_ctx *sctx)
451{
452 if (atomic_dec_and_test(&sctx->refs))
453 scrub_free_ctx(sctx);
454}
455
456static noinline_for_stack
457struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
458{
459 struct scrub_ctx *sctx;
460 int i;
461 struct btrfs_fs_info *fs_info = dev->fs_info;
462 int ret;
463
464 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
465 if (!sctx)
466 goto nomem;
467 atomic_set(&sctx->refs, 1);
468 sctx->is_dev_replace = is_dev_replace;
469 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
470 sctx->curr = -1;
471 sctx->fs_info = dev->fs_info;
472 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
473 struct scrub_bio *sbio;
474
475 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
476 if (!sbio)
477 goto nomem;
478 sctx->bios[i] = sbio;
479
480 sbio->index = i;
481 sbio->sctx = sctx;
482 sbio->page_count = 0;
483 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
484 scrub_bio_end_io_worker, NULL, NULL);
485
486 if (i != SCRUB_BIOS_PER_SCTX - 1)
487 sctx->bios[i]->next_free = i + 1;
488 else
489 sctx->bios[i]->next_free = -1;
490 }
491 sctx->first_free = 0;
492 sctx->nodesize = fs_info->nodesize;
493 sctx->sectorsize = fs_info->sectorsize;
494 atomic_set(&sctx->bios_in_flight, 0);
495 atomic_set(&sctx->workers_pending, 0);
496 atomic_set(&sctx->cancel_req, 0);
497 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
498 INIT_LIST_HEAD(&sctx->csum_list);
499
500 spin_lock_init(&sctx->list_lock);
501 spin_lock_init(&sctx->stat_lock);
502 init_waitqueue_head(&sctx->list_wait);
503
504 ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
505 fs_info->dev_replace.tgtdev, is_dev_replace);
506 if (ret) {
507 scrub_free_ctx(sctx);
508 return ERR_PTR(ret);
509 }
510 return sctx;
511
512nomem:
513 scrub_free_ctx(sctx);
514 return ERR_PTR(-ENOMEM);
515}
516
517static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
518 void *warn_ctx)
519{
520 u64 isize;
521 u32 nlink;
522 int ret;
523 int i;
524 struct extent_buffer *eb;
525 struct btrfs_inode_item *inode_item;
526 struct scrub_warning *swarn = warn_ctx;
527 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
528 struct inode_fs_paths *ipath = NULL;
529 struct btrfs_root *local_root;
530 struct btrfs_key root_key;
531 struct btrfs_key key;
532
533 root_key.objectid = root;
534 root_key.type = BTRFS_ROOT_ITEM_KEY;
535 root_key.offset = (u64)-1;
536 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
537 if (IS_ERR(local_root)) {
538 ret = PTR_ERR(local_root);
539 goto err;
540 }
541
542 /*
543 * this makes the path point to (inum INODE_ITEM ioff)
544 */
545 key.objectid = inum;
546 key.type = BTRFS_INODE_ITEM_KEY;
547 key.offset = 0;
548
549 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
550 if (ret) {
551 btrfs_release_path(swarn->path);
552 goto err;
553 }
554
555 eb = swarn->path->nodes[0];
556 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
557 struct btrfs_inode_item);
558 isize = btrfs_inode_size(eb, inode_item);
559 nlink = btrfs_inode_nlink(eb, inode_item);
560 btrfs_release_path(swarn->path);
561
562 ipath = init_ipath(4096, local_root, swarn->path);
563 if (IS_ERR(ipath)) {
564 ret = PTR_ERR(ipath);
565 ipath = NULL;
566 goto err;
567 }
568 ret = paths_from_inode(inum, ipath);
569
570 if (ret < 0)
571 goto err;
572
573 /*
574 * we deliberately ignore the bit ipath might have been too small to
575 * hold all of the paths here
576 */
577 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
578 btrfs_warn_in_rcu(fs_info,
579 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
580 swarn->errstr, swarn->logical,
581 rcu_str_deref(swarn->dev->name),
582 (unsigned long long)swarn->sector,
583 root, inum, offset,
584 min(isize - offset, (u64)PAGE_SIZE), nlink,
585 (char *)(unsigned long)ipath->fspath->val[i]);
586
587 free_ipath(ipath);
588 return 0;
589
590err:
591 btrfs_warn_in_rcu(fs_info,
592 "%s at logical %llu on dev %s, sector %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
593 swarn->errstr, swarn->logical,
594 rcu_str_deref(swarn->dev->name),
595 (unsigned long long)swarn->sector,
596 root, inum, offset, ret);
597
598 free_ipath(ipath);
599 return 0;
600}
601
602static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
603{
604 struct btrfs_device *dev;
605 struct btrfs_fs_info *fs_info;
606 struct btrfs_path *path;
607 struct btrfs_key found_key;
608 struct extent_buffer *eb;
609 struct btrfs_extent_item *ei;
610 struct scrub_warning swarn;
611 unsigned long ptr = 0;
612 u64 extent_item_pos;
613 u64 flags = 0;
614 u64 ref_root;
615 u32 item_size;
616 u8 ref_level = 0;
617 int ret;
618
619 WARN_ON(sblock->page_count < 1);
620 dev = sblock->pagev[0]->dev;
621 fs_info = sblock->sctx->fs_info;
622
623 path = btrfs_alloc_path();
624 if (!path)
625 return;
626
627 swarn.sector = (sblock->pagev[0]->physical) >> 9;
628 swarn.logical = sblock->pagev[0]->logical;
629 swarn.errstr = errstr;
630 swarn.dev = NULL;
631
632 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
633 &flags);
634 if (ret < 0)
635 goto out;
636
637 extent_item_pos = swarn.logical - found_key.objectid;
638 swarn.extent_item_size = found_key.offset;
639
640 eb = path->nodes[0];
641 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
642 item_size = btrfs_item_size_nr(eb, path->slots[0]);
643
644 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
645 do {
646 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
647 item_size, &ref_root,
648 &ref_level);
649 btrfs_warn_in_rcu(fs_info,
650 "%s at logical %llu on dev %s, sector %llu: metadata %s (level %d) in tree %llu",
651 errstr, swarn.logical,
652 rcu_str_deref(dev->name),
653 (unsigned long long)swarn.sector,
654 ref_level ? "node" : "leaf",
655 ret < 0 ? -1 : ref_level,
656 ret < 0 ? -1 : ref_root);
657 } while (ret != 1);
658 btrfs_release_path(path);
659 } else {
660 btrfs_release_path(path);
661 swarn.path = path;
662 swarn.dev = dev;
663 iterate_extent_inodes(fs_info, found_key.objectid,
664 extent_item_pos, 1,
665 scrub_print_warning_inode, &swarn);
666 }
667
668out:
669 btrfs_free_path(path);
670}
671
672static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
673{
674 struct page *page = NULL;
675 unsigned long index;
676 struct scrub_fixup_nodatasum *fixup = fixup_ctx;
677 int ret;
678 int corrected = 0;
679 struct btrfs_key key;
680 struct inode *inode = NULL;
681 struct btrfs_fs_info *fs_info;
682 u64 end = offset + PAGE_SIZE - 1;
683 struct btrfs_root *local_root;
684 int srcu_index;
685
686 key.objectid = root;
687 key.type = BTRFS_ROOT_ITEM_KEY;
688 key.offset = (u64)-1;
689
690 fs_info = fixup->root->fs_info;
691 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
692
693 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
694 if (IS_ERR(local_root)) {
695 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
696 return PTR_ERR(local_root);
697 }
698
699 key.type = BTRFS_INODE_ITEM_KEY;
700 key.objectid = inum;
701 key.offset = 0;
702 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
703 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
704 if (IS_ERR(inode))
705 return PTR_ERR(inode);
706
707 index = offset >> PAGE_SHIFT;
708
709 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
710 if (!page) {
711 ret = -ENOMEM;
712 goto out;
713 }
714
715 if (PageUptodate(page)) {
716 if (PageDirty(page)) {
717 /*
718 * we need to write the data to the defect sector. the
719 * data that was in that sector is not in memory,
720 * because the page was modified. we must not write the
721 * modified page to that sector.
722 *
723 * TODO: what could be done here: wait for the delalloc
724 * runner to write out that page (might involve
725 * COW) and see whether the sector is still
726 * referenced afterwards.
727 *
728 * For the meantime, we'll treat this error
729 * incorrectable, although there is a chance that a
730 * later scrub will find the bad sector again and that
731 * there's no dirty page in memory, then.
732 */
733 ret = -EIO;
734 goto out;
735 }
736 ret = repair_io_failure(inode, offset, PAGE_SIZE,
737 fixup->logical, page,
738 offset - page_offset(page),
739 fixup->mirror_num);
740 unlock_page(page);
741 corrected = !ret;
742 } else {
743 /*
744 * we need to get good data first. the general readpage path
745 * will call repair_io_failure for us, we just have to make
746 * sure we read the bad mirror.
747 */
748 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
749 EXTENT_DAMAGED);
750 if (ret) {
751 /* set_extent_bits should give proper error */
752 WARN_ON(ret > 0);
753 if (ret > 0)
754 ret = -EFAULT;
755 goto out;
756 }
757
758 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
759 btrfs_get_extent,
760 fixup->mirror_num);
761 wait_on_page_locked(page);
762
763 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
764 end, EXTENT_DAMAGED, 0, NULL);
765 if (!corrected)
766 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
767 EXTENT_DAMAGED);
768 }
769
770out:
771 if (page)
772 put_page(page);
773
774 iput(inode);
775
776 if (ret < 0)
777 return ret;
778
779 if (ret == 0 && corrected) {
780 /*
781 * we only need to call readpage for one of the inodes belonging
782 * to this extent. so make iterate_extent_inodes stop
783 */
784 return 1;
785 }
786
787 return -EIO;
788}
789
790static void scrub_fixup_nodatasum(struct btrfs_work *work)
791{
792 struct btrfs_fs_info *fs_info;
793 int ret;
794 struct scrub_fixup_nodatasum *fixup;
795 struct scrub_ctx *sctx;
796 struct btrfs_trans_handle *trans = NULL;
797 struct btrfs_path *path;
798 int uncorrectable = 0;
799
800 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
801 sctx = fixup->sctx;
802 fs_info = fixup->root->fs_info;
803
804 path = btrfs_alloc_path();
805 if (!path) {
806 spin_lock(&sctx->stat_lock);
807 ++sctx->stat.malloc_errors;
808 spin_unlock(&sctx->stat_lock);
809 uncorrectable = 1;
810 goto out;
811 }
812
813 trans = btrfs_join_transaction(fixup->root);
814 if (IS_ERR(trans)) {
815 uncorrectable = 1;
816 goto out;
817 }
818
819 /*
820 * the idea is to trigger a regular read through the standard path. we
821 * read a page from the (failed) logical address by specifying the
822 * corresponding copynum of the failed sector. thus, that readpage is
823 * expected to fail.
824 * that is the point where on-the-fly error correction will kick in
825 * (once it's finished) and rewrite the failed sector if a good copy
826 * can be found.
827 */
828 ret = iterate_inodes_from_logical(fixup->logical, fs_info, path,
829 scrub_fixup_readpage, fixup);
830 if (ret < 0) {
831 uncorrectable = 1;
832 goto out;
833 }
834 WARN_ON(ret != 1);
835
836 spin_lock(&sctx->stat_lock);
837 ++sctx->stat.corrected_errors;
838 spin_unlock(&sctx->stat_lock);
839
840out:
841 if (trans && !IS_ERR(trans))
842 btrfs_end_transaction(trans);
843 if (uncorrectable) {
844 spin_lock(&sctx->stat_lock);
845 ++sctx->stat.uncorrectable_errors;
846 spin_unlock(&sctx->stat_lock);
847 btrfs_dev_replace_stats_inc(
848 &fs_info->dev_replace.num_uncorrectable_read_errors);
849 btrfs_err_rl_in_rcu(fs_info,
850 "unable to fixup (nodatasum) error at logical %llu on dev %s",
851 fixup->logical, rcu_str_deref(fixup->dev->name));
852 }
853
854 btrfs_free_path(path);
855 kfree(fixup);
856
857 scrub_pending_trans_workers_dec(sctx);
858}
859
860static inline void scrub_get_recover(struct scrub_recover *recover)
861{
862 atomic_inc(&recover->refs);
863}
864
865static inline void scrub_put_recover(struct scrub_recover *recover)
866{
867 if (atomic_dec_and_test(&recover->refs)) {
868 btrfs_put_bbio(recover->bbio);
869 kfree(recover);
870 }
871}
872
873/*
874 * scrub_handle_errored_block gets called when either verification of the
875 * pages failed or the bio failed to read, e.g. with EIO. In the latter
876 * case, this function handles all pages in the bio, even though only one
877 * may be bad.
878 * The goal of this function is to repair the errored block by using the
879 * contents of one of the mirrors.
880 */
881static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
882{
883 struct scrub_ctx *sctx = sblock_to_check->sctx;
884 struct btrfs_device *dev;
885 struct btrfs_fs_info *fs_info;
886 u64 length;
887 u64 logical;
888 unsigned int failed_mirror_index;
889 unsigned int is_metadata;
890 unsigned int have_csum;
891 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
892 struct scrub_block *sblock_bad;
893 int ret;
894 int mirror_index;
895 int page_num;
896 int success;
897 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
898 DEFAULT_RATELIMIT_BURST);
899
900 BUG_ON(sblock_to_check->page_count < 1);
901 fs_info = sctx->fs_info;
902 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
903 /*
904 * if we find an error in a super block, we just report it.
905 * They will get written with the next transaction commit
906 * anyway
907 */
908 spin_lock(&sctx->stat_lock);
909 ++sctx->stat.super_errors;
910 spin_unlock(&sctx->stat_lock);
911 return 0;
912 }
913 length = sblock_to_check->page_count * PAGE_SIZE;
914 logical = sblock_to_check->pagev[0]->logical;
915 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
916 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
917 is_metadata = !(sblock_to_check->pagev[0]->flags &
918 BTRFS_EXTENT_FLAG_DATA);
919 have_csum = sblock_to_check->pagev[0]->have_csum;
920 dev = sblock_to_check->pagev[0]->dev;
921
922 if (sctx->is_dev_replace && !is_metadata && !have_csum) {
923 sblocks_for_recheck = NULL;
924 goto nodatasum_case;
925 }
926
927 /*
928 * read all mirrors one after the other. This includes to
929 * re-read the extent or metadata block that failed (that was
930 * the cause that this fixup code is called) another time,
931 * page by page this time in order to know which pages
932 * caused I/O errors and which ones are good (for all mirrors).
933 * It is the goal to handle the situation when more than one
934 * mirror contains I/O errors, but the errors do not
935 * overlap, i.e. the data can be repaired by selecting the
936 * pages from those mirrors without I/O error on the
937 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
938 * would be that mirror #1 has an I/O error on the first page,
939 * the second page is good, and mirror #2 has an I/O error on
940 * the second page, but the first page is good.
941 * Then the first page of the first mirror can be repaired by
942 * taking the first page of the second mirror, and the
943 * second page of the second mirror can be repaired by
944 * copying the contents of the 2nd page of the 1st mirror.
945 * One more note: if the pages of one mirror contain I/O
946 * errors, the checksum cannot be verified. In order to get
947 * the best data for repairing, the first attempt is to find
948 * a mirror without I/O errors and with a validated checksum.
949 * Only if this is not possible, the pages are picked from
950 * mirrors with I/O errors without considering the checksum.
951 * If the latter is the case, at the end, the checksum of the
952 * repaired area is verified in order to correctly maintain
953 * the statistics.
954 */
955
956 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
957 sizeof(*sblocks_for_recheck), GFP_NOFS);
958 if (!sblocks_for_recheck) {
959 spin_lock(&sctx->stat_lock);
960 sctx->stat.malloc_errors++;
961 sctx->stat.read_errors++;
962 sctx->stat.uncorrectable_errors++;
963 spin_unlock(&sctx->stat_lock);
964 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
965 goto out;
966 }
967
968 /* setup the context, map the logical blocks and alloc the pages */
969 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
970 if (ret) {
971 spin_lock(&sctx->stat_lock);
972 sctx->stat.read_errors++;
973 sctx->stat.uncorrectable_errors++;
974 spin_unlock(&sctx->stat_lock);
975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
976 goto out;
977 }
978 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
979 sblock_bad = sblocks_for_recheck + failed_mirror_index;
980
981 /* build and submit the bios for the failed mirror, check checksums */
982 scrub_recheck_block(fs_info, sblock_bad, 1);
983
984 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
985 sblock_bad->no_io_error_seen) {
986 /*
987 * the error disappeared after reading page by page, or
988 * the area was part of a huge bio and other parts of the
989 * bio caused I/O errors, or the block layer merged several
990 * read requests into one and the error is caused by a
991 * different bio (usually one of the two latter cases is
992 * the cause)
993 */
994 spin_lock(&sctx->stat_lock);
995 sctx->stat.unverified_errors++;
996 sblock_to_check->data_corrected = 1;
997 spin_unlock(&sctx->stat_lock);
998
999 if (sctx->is_dev_replace)
1000 scrub_write_block_to_dev_replace(sblock_bad);
1001 goto out;
1002 }
1003
1004 if (!sblock_bad->no_io_error_seen) {
1005 spin_lock(&sctx->stat_lock);
1006 sctx->stat.read_errors++;
1007 spin_unlock(&sctx->stat_lock);
1008 if (__ratelimit(&_rs))
1009 scrub_print_warning("i/o error", sblock_to_check);
1010 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
1011 } else if (sblock_bad->checksum_error) {
1012 spin_lock(&sctx->stat_lock);
1013 sctx->stat.csum_errors++;
1014 spin_unlock(&sctx->stat_lock);
1015 if (__ratelimit(&_rs))
1016 scrub_print_warning("checksum error", sblock_to_check);
1017 btrfs_dev_stat_inc_and_print(dev,
1018 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1019 } else if (sblock_bad->header_error) {
1020 spin_lock(&sctx->stat_lock);
1021 sctx->stat.verify_errors++;
1022 spin_unlock(&sctx->stat_lock);
1023 if (__ratelimit(&_rs))
1024 scrub_print_warning("checksum/header error",
1025 sblock_to_check);
1026 if (sblock_bad->generation_error)
1027 btrfs_dev_stat_inc_and_print(dev,
1028 BTRFS_DEV_STAT_GENERATION_ERRS);
1029 else
1030 btrfs_dev_stat_inc_and_print(dev,
1031 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1032 }
1033
1034 if (sctx->readonly) {
1035 ASSERT(!sctx->is_dev_replace);
1036 goto out;
1037 }
1038
1039 if (!is_metadata && !have_csum) {
1040 struct scrub_fixup_nodatasum *fixup_nodatasum;
1041
1042 WARN_ON(sctx->is_dev_replace);
1043
1044nodatasum_case:
1045
1046 /*
1047 * !is_metadata and !have_csum, this means that the data
1048 * might not be COWed, that it might be modified
1049 * concurrently. The general strategy to work on the
1050 * commit root does not help in the case when COW is not
1051 * used.
1052 */
1053 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
1054 if (!fixup_nodatasum)
1055 goto did_not_correct_error;
1056 fixup_nodatasum->sctx = sctx;
1057 fixup_nodatasum->dev = dev;
1058 fixup_nodatasum->logical = logical;
1059 fixup_nodatasum->root = fs_info->extent_root;
1060 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
1061 scrub_pending_trans_workers_inc(sctx);
1062 btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
1063 scrub_fixup_nodatasum, NULL, NULL);
1064 btrfs_queue_work(fs_info->scrub_workers,
1065 &fixup_nodatasum->work);
1066 goto out;
1067 }
1068
1069 /*
1070 * now build and submit the bios for the other mirrors, check
1071 * checksums.
1072 * First try to pick the mirror which is completely without I/O
1073 * errors and also does not have a checksum error.
1074 * If one is found, and if a checksum is present, the full block
1075 * that is known to contain an error is rewritten. Afterwards
1076 * the block is known to be corrected.
1077 * If a mirror is found which is completely correct, and no
1078 * checksum is present, only those pages are rewritten that had
1079 * an I/O error in the block to be repaired, since it cannot be
1080 * determined, which copy of the other pages is better (and it
1081 * could happen otherwise that a correct page would be
1082 * overwritten by a bad one).
1083 */
1084 for (mirror_index = 0;
1085 mirror_index < BTRFS_MAX_MIRRORS &&
1086 sblocks_for_recheck[mirror_index].page_count > 0;
1087 mirror_index++) {
1088 struct scrub_block *sblock_other;
1089
1090 if (mirror_index == failed_mirror_index)
1091 continue;
1092 sblock_other = sblocks_for_recheck + mirror_index;
1093
1094 /* build and submit the bios, check checksums */
1095 scrub_recheck_block(fs_info, sblock_other, 0);
1096
1097 if (!sblock_other->header_error &&
1098 !sblock_other->checksum_error &&
1099 sblock_other->no_io_error_seen) {
1100 if (sctx->is_dev_replace) {
1101 scrub_write_block_to_dev_replace(sblock_other);
1102 goto corrected_error;
1103 } else {
1104 ret = scrub_repair_block_from_good_copy(
1105 sblock_bad, sblock_other);
1106 if (!ret)
1107 goto corrected_error;
1108 }
1109 }
1110 }
1111
1112 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1113 goto did_not_correct_error;
1114
1115 /*
1116 * In case of I/O errors in the area that is supposed to be
1117 * repaired, continue by picking good copies of those pages.
1118 * Select the good pages from mirrors to rewrite bad pages from
1119 * the area to fix. Afterwards verify the checksum of the block
1120 * that is supposed to be repaired. This verification step is
1121 * only done for the purpose of statistic counting and for the
1122 * final scrub report, whether errors remain.
1123 * A perfect algorithm could make use of the checksum and try
1124 * all possible combinations of pages from the different mirrors
1125 * until the checksum verification succeeds. For example, when
1126 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1127 * of mirror #2 is readable but the final checksum test fails,
1128 * then the 2nd page of mirror #3 could be tried, whether now
1129 * the final checksum succeeds. But this would be a rare
1130 * exception and is therefore not implemented. At least it is
1131 * avoided that the good copy is overwritten.
1132 * A more useful improvement would be to pick the sectors
1133 * without I/O error based on sector sizes (512 bytes on legacy
1134 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1135 * mirror could be repaired by taking 512 byte of a different
1136 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1137 * area are unreadable.
1138 */
1139 success = 1;
1140 for (page_num = 0; page_num < sblock_bad->page_count;
1141 page_num++) {
1142 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1143 struct scrub_block *sblock_other = NULL;
1144
1145 /* skip no-io-error page in scrub */
1146 if (!page_bad->io_error && !sctx->is_dev_replace)
1147 continue;
1148
1149 /* try to find no-io-error page in mirrors */
1150 if (page_bad->io_error) {
1151 for (mirror_index = 0;
1152 mirror_index < BTRFS_MAX_MIRRORS &&
1153 sblocks_for_recheck[mirror_index].page_count > 0;
1154 mirror_index++) {
1155 if (!sblocks_for_recheck[mirror_index].
1156 pagev[page_num]->io_error) {
1157 sblock_other = sblocks_for_recheck +
1158 mirror_index;
1159 break;
1160 }
1161 }
1162 if (!sblock_other)
1163 success = 0;
1164 }
1165
1166 if (sctx->is_dev_replace) {
1167 /*
1168 * did not find a mirror to fetch the page
1169 * from. scrub_write_page_to_dev_replace()
1170 * handles this case (page->io_error), by
1171 * filling the block with zeros before
1172 * submitting the write request
1173 */
1174 if (!sblock_other)
1175 sblock_other = sblock_bad;
1176
1177 if (scrub_write_page_to_dev_replace(sblock_other,
1178 page_num) != 0) {
1179 btrfs_dev_replace_stats_inc(
1180 &fs_info->dev_replace.num_write_errors);
1181 success = 0;
1182 }
1183 } else if (sblock_other) {
1184 ret = scrub_repair_page_from_good_copy(sblock_bad,
1185 sblock_other,
1186 page_num, 0);
1187 if (0 == ret)
1188 page_bad->io_error = 0;
1189 else
1190 success = 0;
1191 }
1192 }
1193
1194 if (success && !sctx->is_dev_replace) {
1195 if (is_metadata || have_csum) {
1196 /*
1197 * need to verify the checksum now that all
1198 * sectors on disk are repaired (the write
1199 * request for data to be repaired is on its way).
1200 * Just be lazy and use scrub_recheck_block()
1201 * which re-reads the data before the checksum
1202 * is verified, but most likely the data comes out
1203 * of the page cache.
1204 */
1205 scrub_recheck_block(fs_info, sblock_bad, 1);
1206 if (!sblock_bad->header_error &&
1207 !sblock_bad->checksum_error &&
1208 sblock_bad->no_io_error_seen)
1209 goto corrected_error;
1210 else
1211 goto did_not_correct_error;
1212 } else {
1213corrected_error:
1214 spin_lock(&sctx->stat_lock);
1215 sctx->stat.corrected_errors++;
1216 sblock_to_check->data_corrected = 1;
1217 spin_unlock(&sctx->stat_lock);
1218 btrfs_err_rl_in_rcu(fs_info,
1219 "fixed up error at logical %llu on dev %s",
1220 logical, rcu_str_deref(dev->name));
1221 }
1222 } else {
1223did_not_correct_error:
1224 spin_lock(&sctx->stat_lock);
1225 sctx->stat.uncorrectable_errors++;
1226 spin_unlock(&sctx->stat_lock);
1227 btrfs_err_rl_in_rcu(fs_info,
1228 "unable to fixup (regular) error at logical %llu on dev %s",
1229 logical, rcu_str_deref(dev->name));
1230 }
1231
1232out:
1233 if (sblocks_for_recheck) {
1234 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1235 mirror_index++) {
1236 struct scrub_block *sblock = sblocks_for_recheck +
1237 mirror_index;
1238 struct scrub_recover *recover;
1239 int page_index;
1240
1241 for (page_index = 0; page_index < sblock->page_count;
1242 page_index++) {
1243 sblock->pagev[page_index]->sblock = NULL;
1244 recover = sblock->pagev[page_index]->recover;
1245 if (recover) {
1246 scrub_put_recover(recover);
1247 sblock->pagev[page_index]->recover =
1248 NULL;
1249 }
1250 scrub_page_put(sblock->pagev[page_index]);
1251 }
1252 }
1253 kfree(sblocks_for_recheck);
1254 }
1255
1256 return 0;
1257}
1258
1259static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1260{
1261 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1262 return 2;
1263 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1264 return 3;
1265 else
1266 return (int)bbio->num_stripes;
1267}
1268
1269static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1270 u64 *raid_map,
1271 u64 mapped_length,
1272 int nstripes, int mirror,
1273 int *stripe_index,
1274 u64 *stripe_offset)
1275{
1276 int i;
1277
1278 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1279 /* RAID5/6 */
1280 for (i = 0; i < nstripes; i++) {
1281 if (raid_map[i] == RAID6_Q_STRIPE ||
1282 raid_map[i] == RAID5_P_STRIPE)
1283 continue;
1284
1285 if (logical >= raid_map[i] &&
1286 logical < raid_map[i] + mapped_length)
1287 break;
1288 }
1289
1290 *stripe_index = i;
1291 *stripe_offset = logical - raid_map[i];
1292 } else {
1293 /* The other RAID type */
1294 *stripe_index = mirror;
1295 *stripe_offset = 0;
1296 }
1297}
1298
1299static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1300 struct scrub_block *sblocks_for_recheck)
1301{
1302 struct scrub_ctx *sctx = original_sblock->sctx;
1303 struct btrfs_fs_info *fs_info = sctx->fs_info;
1304 u64 length = original_sblock->page_count * PAGE_SIZE;
1305 u64 logical = original_sblock->pagev[0]->logical;
1306 u64 generation = original_sblock->pagev[0]->generation;
1307 u64 flags = original_sblock->pagev[0]->flags;
1308 u64 have_csum = original_sblock->pagev[0]->have_csum;
1309 struct scrub_recover *recover;
1310 struct btrfs_bio *bbio;
1311 u64 sublen;
1312 u64 mapped_length;
1313 u64 stripe_offset;
1314 int stripe_index;
1315 int page_index = 0;
1316 int mirror_index;
1317 int nmirrors;
1318 int ret;
1319
1320 /*
1321 * note: the two members refs and outstanding_pages
1322 * are not used (and not set) in the blocks that are used for
1323 * the recheck procedure
1324 */
1325
1326 while (length > 0) {
1327 sublen = min_t(u64, length, PAGE_SIZE);
1328 mapped_length = sublen;
1329 bbio = NULL;
1330
1331 /*
1332 * with a length of PAGE_SIZE, each returned stripe
1333 * represents one mirror
1334 */
1335 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1336 logical, &mapped_length, &bbio, 0, 1);
1337 if (ret || !bbio || mapped_length < sublen) {
1338 btrfs_put_bbio(bbio);
1339 return -EIO;
1340 }
1341
1342 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1343 if (!recover) {
1344 btrfs_put_bbio(bbio);
1345 return -ENOMEM;
1346 }
1347
1348 atomic_set(&recover->refs, 1);
1349 recover->bbio = bbio;
1350 recover->map_length = mapped_length;
1351
1352 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1353
1354 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1355
1356 for (mirror_index = 0; mirror_index < nmirrors;
1357 mirror_index++) {
1358 struct scrub_block *sblock;
1359 struct scrub_page *page;
1360
1361 sblock = sblocks_for_recheck + mirror_index;
1362 sblock->sctx = sctx;
1363
1364 page = kzalloc(sizeof(*page), GFP_NOFS);
1365 if (!page) {
1366leave_nomem:
1367 spin_lock(&sctx->stat_lock);
1368 sctx->stat.malloc_errors++;
1369 spin_unlock(&sctx->stat_lock);
1370 scrub_put_recover(recover);
1371 return -ENOMEM;
1372 }
1373 scrub_page_get(page);
1374 sblock->pagev[page_index] = page;
1375 page->sblock = sblock;
1376 page->flags = flags;
1377 page->generation = generation;
1378 page->logical = logical;
1379 page->have_csum = have_csum;
1380 if (have_csum)
1381 memcpy(page->csum,
1382 original_sblock->pagev[0]->csum,
1383 sctx->csum_size);
1384
1385 scrub_stripe_index_and_offset(logical,
1386 bbio->map_type,
1387 bbio->raid_map,
1388 mapped_length,
1389 bbio->num_stripes -
1390 bbio->num_tgtdevs,
1391 mirror_index,
1392 &stripe_index,
1393 &stripe_offset);
1394 page->physical = bbio->stripes[stripe_index].physical +
1395 stripe_offset;
1396 page->dev = bbio->stripes[stripe_index].dev;
1397
1398 BUG_ON(page_index >= original_sblock->page_count);
1399 page->physical_for_dev_replace =
1400 original_sblock->pagev[page_index]->
1401 physical_for_dev_replace;
1402 /* for missing devices, dev->bdev is NULL */
1403 page->mirror_num = mirror_index + 1;
1404 sblock->page_count++;
1405 page->page = alloc_page(GFP_NOFS);
1406 if (!page->page)
1407 goto leave_nomem;
1408
1409 scrub_get_recover(recover);
1410 page->recover = recover;
1411 }
1412 scrub_put_recover(recover);
1413 length -= sublen;
1414 logical += sublen;
1415 page_index++;
1416 }
1417
1418 return 0;
1419}
1420
1421struct scrub_bio_ret {
1422 struct completion event;
1423 int error;
1424};
1425
1426static void scrub_bio_wait_endio(struct bio *bio)
1427{
1428 struct scrub_bio_ret *ret = bio->bi_private;
1429
1430 ret->error = bio->bi_error;
1431 complete(&ret->event);
1432}
1433
1434static inline int scrub_is_page_on_raid56(struct scrub_page *page)
1435{
1436 return page->recover &&
1437 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
1438}
1439
1440static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1441 struct bio *bio,
1442 struct scrub_page *page)
1443{
1444 struct scrub_bio_ret done;
1445 int ret;
1446
1447 init_completion(&done.event);
1448 done.error = 0;
1449 bio->bi_iter.bi_sector = page->logical >> 9;
1450 bio->bi_private = &done;
1451 bio->bi_end_io = scrub_bio_wait_endio;
1452
1453 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1454 page->recover->map_length,
1455 page->mirror_num, 0);
1456 if (ret)
1457 return ret;
1458
1459 wait_for_completion(&done.event);
1460 if (done.error)
1461 return -EIO;
1462
1463 return 0;
1464}
1465
1466/*
1467 * this function will check the on disk data for checksum errors, header
1468 * errors and read I/O errors. If any I/O errors happen, the exact pages
1469 * which are errored are marked as being bad. The goal is to enable scrub
1470 * to take those pages that are not errored from all the mirrors so that
1471 * the pages that are errored in the just handled mirror can be repaired.
1472 */
1473static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1474 struct scrub_block *sblock,
1475 int retry_failed_mirror)
1476{
1477 int page_num;
1478
1479 sblock->no_io_error_seen = 1;
1480
1481 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1482 struct bio *bio;
1483 struct scrub_page *page = sblock->pagev[page_num];
1484
1485 if (page->dev->bdev == NULL) {
1486 page->io_error = 1;
1487 sblock->no_io_error_seen = 0;
1488 continue;
1489 }
1490
1491 WARN_ON(!page->page);
1492 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1493 if (!bio) {
1494 page->io_error = 1;
1495 sblock->no_io_error_seen = 0;
1496 continue;
1497 }
1498 bio->bi_bdev = page->dev->bdev;
1499
1500 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1501 if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
1502 if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
1503 sblock->no_io_error_seen = 0;
1504 } else {
1505 bio->bi_iter.bi_sector = page->physical >> 9;
1506 bio_set_op_attrs(bio, REQ_OP_READ, 0);
1507
1508 if (btrfsic_submit_bio_wait(bio))
1509 sblock->no_io_error_seen = 0;
1510 }
1511
1512 bio_put(bio);
1513 }
1514
1515 if (sblock->no_io_error_seen)
1516 scrub_recheck_block_checksum(sblock);
1517}
1518
1519static inline int scrub_check_fsid(u8 fsid[],
1520 struct scrub_page *spage)
1521{
1522 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1523 int ret;
1524
1525 ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
1526 return !ret;
1527}
1528
1529static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1530{
1531 sblock->header_error = 0;
1532 sblock->checksum_error = 0;
1533 sblock->generation_error = 0;
1534
1535 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1536 scrub_checksum_data(sblock);
1537 else
1538 scrub_checksum_tree_block(sblock);
1539}
1540
1541static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1542 struct scrub_block *sblock_good)
1543{
1544 int page_num;
1545 int ret = 0;
1546
1547 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1548 int ret_sub;
1549
1550 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1551 sblock_good,
1552 page_num, 1);
1553 if (ret_sub)
1554 ret = ret_sub;
1555 }
1556
1557 return ret;
1558}
1559
1560static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1561 struct scrub_block *sblock_good,
1562 int page_num, int force_write)
1563{
1564 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1565 struct scrub_page *page_good = sblock_good->pagev[page_num];
1566 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1567
1568 BUG_ON(page_bad->page == NULL);
1569 BUG_ON(page_good->page == NULL);
1570 if (force_write || sblock_bad->header_error ||
1571 sblock_bad->checksum_error || page_bad->io_error) {
1572 struct bio *bio;
1573 int ret;
1574
1575 if (!page_bad->dev->bdev) {
1576 btrfs_warn_rl(fs_info,
1577 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1578 return -EIO;
1579 }
1580
1581 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
1582 if (!bio)
1583 return -EIO;
1584 bio->bi_bdev = page_bad->dev->bdev;
1585 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1586 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1587
1588 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1589 if (PAGE_SIZE != ret) {
1590 bio_put(bio);
1591 return -EIO;
1592 }
1593
1594 if (btrfsic_submit_bio_wait(bio)) {
1595 btrfs_dev_stat_inc_and_print(page_bad->dev,
1596 BTRFS_DEV_STAT_WRITE_ERRS);
1597 btrfs_dev_replace_stats_inc(
1598 &fs_info->dev_replace.num_write_errors);
1599 bio_put(bio);
1600 return -EIO;
1601 }
1602 bio_put(bio);
1603 }
1604
1605 return 0;
1606}
1607
1608static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1609{
1610 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1611 int page_num;
1612
1613 /*
1614 * This block is used for the check of the parity on the source device,
1615 * so the data needn't be written into the destination device.
1616 */
1617 if (sblock->sparity)
1618 return;
1619
1620 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1621 int ret;
1622
1623 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1624 if (ret)
1625 btrfs_dev_replace_stats_inc(
1626 &fs_info->dev_replace.num_write_errors);
1627 }
1628}
1629
1630static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1631 int page_num)
1632{
1633 struct scrub_page *spage = sblock->pagev[page_num];
1634
1635 BUG_ON(spage->page == NULL);
1636 if (spage->io_error) {
1637 void *mapped_buffer = kmap_atomic(spage->page);
1638
1639 memset(mapped_buffer, 0, PAGE_SIZE);
1640 flush_dcache_page(spage->page);
1641 kunmap_atomic(mapped_buffer);
1642 }
1643 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1644}
1645
1646static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1647 struct scrub_page *spage)
1648{
1649 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1650 struct scrub_bio *sbio;
1651 int ret;
1652
1653 mutex_lock(&wr_ctx->wr_lock);
1654again:
1655 if (!wr_ctx->wr_curr_bio) {
1656 wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
1657 GFP_KERNEL);
1658 if (!wr_ctx->wr_curr_bio) {
1659 mutex_unlock(&wr_ctx->wr_lock);
1660 return -ENOMEM;
1661 }
1662 wr_ctx->wr_curr_bio->sctx = sctx;
1663 wr_ctx->wr_curr_bio->page_count = 0;
1664 }
1665 sbio = wr_ctx->wr_curr_bio;
1666 if (sbio->page_count == 0) {
1667 struct bio *bio;
1668
1669 sbio->physical = spage->physical_for_dev_replace;
1670 sbio->logical = spage->logical;
1671 sbio->dev = wr_ctx->tgtdev;
1672 bio = sbio->bio;
1673 if (!bio) {
1674 bio = btrfs_io_bio_alloc(GFP_KERNEL,
1675 wr_ctx->pages_per_wr_bio);
1676 if (!bio) {
1677 mutex_unlock(&wr_ctx->wr_lock);
1678 return -ENOMEM;
1679 }
1680 sbio->bio = bio;
1681 }
1682
1683 bio->bi_private = sbio;
1684 bio->bi_end_io = scrub_wr_bio_end_io;
1685 bio->bi_bdev = sbio->dev->bdev;
1686 bio->bi_iter.bi_sector = sbio->physical >> 9;
1687 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
1688 sbio->err = 0;
1689 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1690 spage->physical_for_dev_replace ||
1691 sbio->logical + sbio->page_count * PAGE_SIZE !=
1692 spage->logical) {
1693 scrub_wr_submit(sctx);
1694 goto again;
1695 }
1696
1697 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1698 if (ret != PAGE_SIZE) {
1699 if (sbio->page_count < 1) {
1700 bio_put(sbio->bio);
1701 sbio->bio = NULL;
1702 mutex_unlock(&wr_ctx->wr_lock);
1703 return -EIO;
1704 }
1705 scrub_wr_submit(sctx);
1706 goto again;
1707 }
1708
1709 sbio->pagev[sbio->page_count] = spage;
1710 scrub_page_get(spage);
1711 sbio->page_count++;
1712 if (sbio->page_count == wr_ctx->pages_per_wr_bio)
1713 scrub_wr_submit(sctx);
1714 mutex_unlock(&wr_ctx->wr_lock);
1715
1716 return 0;
1717}
1718
1719static void scrub_wr_submit(struct scrub_ctx *sctx)
1720{
1721 struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
1722 struct scrub_bio *sbio;
1723
1724 if (!wr_ctx->wr_curr_bio)
1725 return;
1726
1727 sbio = wr_ctx->wr_curr_bio;
1728 wr_ctx->wr_curr_bio = NULL;
1729 WARN_ON(!sbio->bio->bi_bdev);
1730 scrub_pending_bio_inc(sctx);
1731 /* process all writes in a single worker thread. Then the block layer
1732 * orders the requests before sending them to the driver which
1733 * doubled the write performance on spinning disks when measured
1734 * with Linux 3.5 */
1735 btrfsic_submit_bio(sbio->bio);
1736}
1737
1738static void scrub_wr_bio_end_io(struct bio *bio)
1739{
1740 struct scrub_bio *sbio = bio->bi_private;
1741 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
1742
1743 sbio->err = bio->bi_error;
1744 sbio->bio = bio;
1745
1746 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1747 scrub_wr_bio_end_io_worker, NULL, NULL);
1748 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1749}
1750
1751static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1752{
1753 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1754 struct scrub_ctx *sctx = sbio->sctx;
1755 int i;
1756
1757 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1758 if (sbio->err) {
1759 struct btrfs_dev_replace *dev_replace =
1760 &sbio->sctx->fs_info->dev_replace;
1761
1762 for (i = 0; i < sbio->page_count; i++) {
1763 struct scrub_page *spage = sbio->pagev[i];
1764
1765 spage->io_error = 1;
1766 btrfs_dev_replace_stats_inc(&dev_replace->
1767 num_write_errors);
1768 }
1769 }
1770
1771 for (i = 0; i < sbio->page_count; i++)
1772 scrub_page_put(sbio->pagev[i]);
1773
1774 bio_put(sbio->bio);
1775 kfree(sbio);
1776 scrub_pending_bio_dec(sctx);
1777}
1778
1779static int scrub_checksum(struct scrub_block *sblock)
1780{
1781 u64 flags;
1782 int ret;
1783
1784 /*
1785 * No need to initialize these stats currently,
1786 * because this function only use return value
1787 * instead of these stats value.
1788 *
1789 * Todo:
1790 * always use stats
1791 */
1792 sblock->header_error = 0;
1793 sblock->generation_error = 0;
1794 sblock->checksum_error = 0;
1795
1796 WARN_ON(sblock->page_count < 1);
1797 flags = sblock->pagev[0]->flags;
1798 ret = 0;
1799 if (flags & BTRFS_EXTENT_FLAG_DATA)
1800 ret = scrub_checksum_data(sblock);
1801 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1802 ret = scrub_checksum_tree_block(sblock);
1803 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1804 (void)scrub_checksum_super(sblock);
1805 else
1806 WARN_ON(1);
1807 if (ret)
1808 scrub_handle_errored_block(sblock);
1809
1810 return ret;
1811}
1812
1813static int scrub_checksum_data(struct scrub_block *sblock)
1814{
1815 struct scrub_ctx *sctx = sblock->sctx;
1816 u8 csum[BTRFS_CSUM_SIZE];
1817 u8 *on_disk_csum;
1818 struct page *page;
1819 void *buffer;
1820 u32 crc = ~(u32)0;
1821 u64 len;
1822 int index;
1823
1824 BUG_ON(sblock->page_count < 1);
1825 if (!sblock->pagev[0]->have_csum)
1826 return 0;
1827
1828 on_disk_csum = sblock->pagev[0]->csum;
1829 page = sblock->pagev[0]->page;
1830 buffer = kmap_atomic(page);
1831
1832 len = sctx->sectorsize;
1833 index = 0;
1834 for (;;) {
1835 u64 l = min_t(u64, len, PAGE_SIZE);
1836
1837 crc = btrfs_csum_data(buffer, crc, l);
1838 kunmap_atomic(buffer);
1839 len -= l;
1840 if (len == 0)
1841 break;
1842 index++;
1843 BUG_ON(index >= sblock->page_count);
1844 BUG_ON(!sblock->pagev[index]->page);
1845 page = sblock->pagev[index]->page;
1846 buffer = kmap_atomic(page);
1847 }
1848
1849 btrfs_csum_final(crc, csum);
1850 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1851 sblock->checksum_error = 1;
1852
1853 return sblock->checksum_error;
1854}
1855
1856static int scrub_checksum_tree_block(struct scrub_block *sblock)
1857{
1858 struct scrub_ctx *sctx = sblock->sctx;
1859 struct btrfs_header *h;
1860 struct btrfs_fs_info *fs_info = sctx->fs_info;
1861 u8 calculated_csum[BTRFS_CSUM_SIZE];
1862 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1863 struct page *page;
1864 void *mapped_buffer;
1865 u64 mapped_size;
1866 void *p;
1867 u32 crc = ~(u32)0;
1868 u64 len;
1869 int index;
1870
1871 BUG_ON(sblock->page_count < 1);
1872 page = sblock->pagev[0]->page;
1873 mapped_buffer = kmap_atomic(page);
1874 h = (struct btrfs_header *)mapped_buffer;
1875 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1876
1877 /*
1878 * we don't use the getter functions here, as we
1879 * a) don't have an extent buffer and
1880 * b) the page is already kmapped
1881 */
1882 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1883 sblock->header_error = 1;
1884
1885 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1886 sblock->header_error = 1;
1887 sblock->generation_error = 1;
1888 }
1889
1890 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1891 sblock->header_error = 1;
1892
1893 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1894 BTRFS_UUID_SIZE))
1895 sblock->header_error = 1;
1896
1897 len = sctx->nodesize - BTRFS_CSUM_SIZE;
1898 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1899 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1900 index = 0;
1901 for (;;) {
1902 u64 l = min_t(u64, len, mapped_size);
1903
1904 crc = btrfs_csum_data(p, crc, l);
1905 kunmap_atomic(mapped_buffer);
1906 len -= l;
1907 if (len == 0)
1908 break;
1909 index++;
1910 BUG_ON(index >= sblock->page_count);
1911 BUG_ON(!sblock->pagev[index]->page);
1912 page = sblock->pagev[index]->page;
1913 mapped_buffer = kmap_atomic(page);
1914 mapped_size = PAGE_SIZE;
1915 p = mapped_buffer;
1916 }
1917
1918 btrfs_csum_final(crc, calculated_csum);
1919 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1920 sblock->checksum_error = 1;
1921
1922 return sblock->header_error || sblock->checksum_error;
1923}
1924
1925static int scrub_checksum_super(struct scrub_block *sblock)
1926{
1927 struct btrfs_super_block *s;
1928 struct scrub_ctx *sctx = sblock->sctx;
1929 u8 calculated_csum[BTRFS_CSUM_SIZE];
1930 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1931 struct page *page;
1932 void *mapped_buffer;
1933 u64 mapped_size;
1934 void *p;
1935 u32 crc = ~(u32)0;
1936 int fail_gen = 0;
1937 int fail_cor = 0;
1938 u64 len;
1939 int index;
1940
1941 BUG_ON(sblock->page_count < 1);
1942 page = sblock->pagev[0]->page;
1943 mapped_buffer = kmap_atomic(page);
1944 s = (struct btrfs_super_block *)mapped_buffer;
1945 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1946
1947 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1948 ++fail_cor;
1949
1950 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1951 ++fail_gen;
1952
1953 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1954 ++fail_cor;
1955
1956 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1957 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1958 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1959 index = 0;
1960 for (;;) {
1961 u64 l = min_t(u64, len, mapped_size);
1962
1963 crc = btrfs_csum_data(p, crc, l);
1964 kunmap_atomic(mapped_buffer);
1965 len -= l;
1966 if (len == 0)
1967 break;
1968 index++;
1969 BUG_ON(index >= sblock->page_count);
1970 BUG_ON(!sblock->pagev[index]->page);
1971 page = sblock->pagev[index]->page;
1972 mapped_buffer = kmap_atomic(page);
1973 mapped_size = PAGE_SIZE;
1974 p = mapped_buffer;
1975 }
1976
1977 btrfs_csum_final(crc, calculated_csum);
1978 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1979 ++fail_cor;
1980
1981 if (fail_cor + fail_gen) {
1982 /*
1983 * if we find an error in a super block, we just report it.
1984 * They will get written with the next transaction commit
1985 * anyway
1986 */
1987 spin_lock(&sctx->stat_lock);
1988 ++sctx->stat.super_errors;
1989 spin_unlock(&sctx->stat_lock);
1990 if (fail_cor)
1991 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1992 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1993 else
1994 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1995 BTRFS_DEV_STAT_GENERATION_ERRS);
1996 }
1997
1998 return fail_cor + fail_gen;
1999}
2000
2001static void scrub_block_get(struct scrub_block *sblock)
2002{
2003 atomic_inc(&sblock->refs);
2004}
2005
2006static void scrub_block_put(struct scrub_block *sblock)
2007{
2008 if (atomic_dec_and_test(&sblock->refs)) {
2009 int i;
2010
2011 if (sblock->sparity)
2012 scrub_parity_put(sblock->sparity);
2013
2014 for (i = 0; i < sblock->page_count; i++)
2015 scrub_page_put(sblock->pagev[i]);
2016 kfree(sblock);
2017 }
2018}
2019
2020static void scrub_page_get(struct scrub_page *spage)
2021{
2022 atomic_inc(&spage->refs);
2023}
2024
2025static void scrub_page_put(struct scrub_page *spage)
2026{
2027 if (atomic_dec_and_test(&spage->refs)) {
2028 if (spage->page)
2029 __free_page(spage->page);
2030 kfree(spage);
2031 }
2032}
2033
2034static void scrub_submit(struct scrub_ctx *sctx)
2035{
2036 struct scrub_bio *sbio;
2037
2038 if (sctx->curr == -1)
2039 return;
2040
2041 sbio = sctx->bios[sctx->curr];
2042 sctx->curr = -1;
2043 scrub_pending_bio_inc(sctx);
2044 btrfsic_submit_bio(sbio->bio);
2045}
2046
2047static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2048 struct scrub_page *spage)
2049{
2050 struct scrub_block *sblock = spage->sblock;
2051 struct scrub_bio *sbio;
2052 int ret;
2053
2054again:
2055 /*
2056 * grab a fresh bio or wait for one to become available
2057 */
2058 while (sctx->curr == -1) {
2059 spin_lock(&sctx->list_lock);
2060 sctx->curr = sctx->first_free;
2061 if (sctx->curr != -1) {
2062 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2063 sctx->bios[sctx->curr]->next_free = -1;
2064 sctx->bios[sctx->curr]->page_count = 0;
2065 spin_unlock(&sctx->list_lock);
2066 } else {
2067 spin_unlock(&sctx->list_lock);
2068 wait_event(sctx->list_wait, sctx->first_free != -1);
2069 }
2070 }
2071 sbio = sctx->bios[sctx->curr];
2072 if (sbio->page_count == 0) {
2073 struct bio *bio;
2074
2075 sbio->physical = spage->physical;
2076 sbio->logical = spage->logical;
2077 sbio->dev = spage->dev;
2078 bio = sbio->bio;
2079 if (!bio) {
2080 bio = btrfs_io_bio_alloc(GFP_KERNEL,
2081 sctx->pages_per_rd_bio);
2082 if (!bio)
2083 return -ENOMEM;
2084 sbio->bio = bio;
2085 }
2086
2087 bio->bi_private = sbio;
2088 bio->bi_end_io = scrub_bio_end_io;
2089 bio->bi_bdev = sbio->dev->bdev;
2090 bio->bi_iter.bi_sector = sbio->physical >> 9;
2091 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2092 sbio->err = 0;
2093 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2094 spage->physical ||
2095 sbio->logical + sbio->page_count * PAGE_SIZE !=
2096 spage->logical ||
2097 sbio->dev != spage->dev) {
2098 scrub_submit(sctx);
2099 goto again;
2100 }
2101
2102 sbio->pagev[sbio->page_count] = spage;
2103 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2104 if (ret != PAGE_SIZE) {
2105 if (sbio->page_count < 1) {
2106 bio_put(sbio->bio);
2107 sbio->bio = NULL;
2108 return -EIO;
2109 }
2110 scrub_submit(sctx);
2111 goto again;
2112 }
2113
2114 scrub_block_get(sblock); /* one for the page added to the bio */
2115 atomic_inc(&sblock->outstanding_pages);
2116 sbio->page_count++;
2117 if (sbio->page_count == sctx->pages_per_rd_bio)
2118 scrub_submit(sctx);
2119
2120 return 0;
2121}
2122
2123static void scrub_missing_raid56_end_io(struct bio *bio)
2124{
2125 struct scrub_block *sblock = bio->bi_private;
2126 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2127
2128 if (bio->bi_error)
2129 sblock->no_io_error_seen = 0;
2130
2131 bio_put(bio);
2132
2133 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2134}
2135
2136static void scrub_missing_raid56_worker(struct btrfs_work *work)
2137{
2138 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2139 struct scrub_ctx *sctx = sblock->sctx;
2140 struct btrfs_fs_info *fs_info = sctx->fs_info;
2141 u64 logical;
2142 struct btrfs_device *dev;
2143
2144 logical = sblock->pagev[0]->logical;
2145 dev = sblock->pagev[0]->dev;
2146
2147 if (sblock->no_io_error_seen)
2148 scrub_recheck_block_checksum(sblock);
2149
2150 if (!sblock->no_io_error_seen) {
2151 spin_lock(&sctx->stat_lock);
2152 sctx->stat.read_errors++;
2153 spin_unlock(&sctx->stat_lock);
2154 btrfs_err_rl_in_rcu(fs_info,
2155 "IO error rebuilding logical %llu for dev %s",
2156 logical, rcu_str_deref(dev->name));
2157 } else if (sblock->header_error || sblock->checksum_error) {
2158 spin_lock(&sctx->stat_lock);
2159 sctx->stat.uncorrectable_errors++;
2160 spin_unlock(&sctx->stat_lock);
2161 btrfs_err_rl_in_rcu(fs_info,
2162 "failed to rebuild valid logical %llu for dev %s",
2163 logical, rcu_str_deref(dev->name));
2164 } else {
2165 scrub_write_block_to_dev_replace(sblock);
2166 }
2167
2168 scrub_block_put(sblock);
2169
2170 if (sctx->is_dev_replace &&
2171 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2172 mutex_lock(&sctx->wr_ctx.wr_lock);
2173 scrub_wr_submit(sctx);
2174 mutex_unlock(&sctx->wr_ctx.wr_lock);
2175 }
2176
2177 scrub_pending_bio_dec(sctx);
2178}
2179
2180static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2181{
2182 struct scrub_ctx *sctx = sblock->sctx;
2183 struct btrfs_fs_info *fs_info = sctx->fs_info;
2184 u64 length = sblock->page_count * PAGE_SIZE;
2185 u64 logical = sblock->pagev[0]->logical;
2186 struct btrfs_bio *bbio = NULL;
2187 struct bio *bio;
2188 struct btrfs_raid_bio *rbio;
2189 int ret;
2190 int i;
2191
2192 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2193 &length, &bbio, 0, 1);
2194 if (ret || !bbio || !bbio->raid_map)
2195 goto bbio_out;
2196
2197 if (WARN_ON(!sctx->is_dev_replace ||
2198 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2199 /*
2200 * We shouldn't be scrubbing a missing device. Even for dev
2201 * replace, we should only get here for RAID 5/6. We either
2202 * managed to mount something with no mirrors remaining or
2203 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2204 */
2205 goto bbio_out;
2206 }
2207
2208 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2209 if (!bio)
2210 goto bbio_out;
2211
2212 bio->bi_iter.bi_sector = logical >> 9;
2213 bio->bi_private = sblock;
2214 bio->bi_end_io = scrub_missing_raid56_end_io;
2215
2216 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2217 if (!rbio)
2218 goto rbio_out;
2219
2220 for (i = 0; i < sblock->page_count; i++) {
2221 struct scrub_page *spage = sblock->pagev[i];
2222
2223 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2224 }
2225
2226 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2227 scrub_missing_raid56_worker, NULL, NULL);
2228 scrub_block_get(sblock);
2229 scrub_pending_bio_inc(sctx);
2230 raid56_submit_missing_rbio(rbio);
2231 return;
2232
2233rbio_out:
2234 bio_put(bio);
2235bbio_out:
2236 btrfs_put_bbio(bbio);
2237 spin_lock(&sctx->stat_lock);
2238 sctx->stat.malloc_errors++;
2239 spin_unlock(&sctx->stat_lock);
2240}
2241
2242static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2243 u64 physical, struct btrfs_device *dev, u64 flags,
2244 u64 gen, int mirror_num, u8 *csum, int force,
2245 u64 physical_for_dev_replace)
2246{
2247 struct scrub_block *sblock;
2248 int index;
2249
2250 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2251 if (!sblock) {
2252 spin_lock(&sctx->stat_lock);
2253 sctx->stat.malloc_errors++;
2254 spin_unlock(&sctx->stat_lock);
2255 return -ENOMEM;
2256 }
2257
2258 /* one ref inside this function, plus one for each page added to
2259 * a bio later on */
2260 atomic_set(&sblock->refs, 1);
2261 sblock->sctx = sctx;
2262 sblock->no_io_error_seen = 1;
2263
2264 for (index = 0; len > 0; index++) {
2265 struct scrub_page *spage;
2266 u64 l = min_t(u64, len, PAGE_SIZE);
2267
2268 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2269 if (!spage) {
2270leave_nomem:
2271 spin_lock(&sctx->stat_lock);
2272 sctx->stat.malloc_errors++;
2273 spin_unlock(&sctx->stat_lock);
2274 scrub_block_put(sblock);
2275 return -ENOMEM;
2276 }
2277 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2278 scrub_page_get(spage);
2279 sblock->pagev[index] = spage;
2280 spage->sblock = sblock;
2281 spage->dev = dev;
2282 spage->flags = flags;
2283 spage->generation = gen;
2284 spage->logical = logical;
2285 spage->physical = physical;
2286 spage->physical_for_dev_replace = physical_for_dev_replace;
2287 spage->mirror_num = mirror_num;
2288 if (csum) {
2289 spage->have_csum = 1;
2290 memcpy(spage->csum, csum, sctx->csum_size);
2291 } else {
2292 spage->have_csum = 0;
2293 }
2294 sblock->page_count++;
2295 spage->page = alloc_page(GFP_KERNEL);
2296 if (!spage->page)
2297 goto leave_nomem;
2298 len -= l;
2299 logical += l;
2300 physical += l;
2301 physical_for_dev_replace += l;
2302 }
2303
2304 WARN_ON(sblock->page_count == 0);
2305 if (dev->missing) {
2306 /*
2307 * This case should only be hit for RAID 5/6 device replace. See
2308 * the comment in scrub_missing_raid56_pages() for details.
2309 */
2310 scrub_missing_raid56_pages(sblock);
2311 } else {
2312 for (index = 0; index < sblock->page_count; index++) {
2313 struct scrub_page *spage = sblock->pagev[index];
2314 int ret;
2315
2316 ret = scrub_add_page_to_rd_bio(sctx, spage);
2317 if (ret) {
2318 scrub_block_put(sblock);
2319 return ret;
2320 }
2321 }
2322
2323 if (force)
2324 scrub_submit(sctx);
2325 }
2326
2327 /* last one frees, either here or in bio completion for last page */
2328 scrub_block_put(sblock);
2329 return 0;
2330}
2331
2332static void scrub_bio_end_io(struct bio *bio)
2333{
2334 struct scrub_bio *sbio = bio->bi_private;
2335 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2336
2337 sbio->err = bio->bi_error;
2338 sbio->bio = bio;
2339
2340 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2341}
2342
2343static void scrub_bio_end_io_worker(struct btrfs_work *work)
2344{
2345 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2346 struct scrub_ctx *sctx = sbio->sctx;
2347 int i;
2348
2349 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2350 if (sbio->err) {
2351 for (i = 0; i < sbio->page_count; i++) {
2352 struct scrub_page *spage = sbio->pagev[i];
2353
2354 spage->io_error = 1;
2355 spage->sblock->no_io_error_seen = 0;
2356 }
2357 }
2358
2359 /* now complete the scrub_block items that have all pages completed */
2360 for (i = 0; i < sbio->page_count; i++) {
2361 struct scrub_page *spage = sbio->pagev[i];
2362 struct scrub_block *sblock = spage->sblock;
2363
2364 if (atomic_dec_and_test(&sblock->outstanding_pages))
2365 scrub_block_complete(sblock);
2366 scrub_block_put(sblock);
2367 }
2368
2369 bio_put(sbio->bio);
2370 sbio->bio = NULL;
2371 spin_lock(&sctx->list_lock);
2372 sbio->next_free = sctx->first_free;
2373 sctx->first_free = sbio->index;
2374 spin_unlock(&sctx->list_lock);
2375
2376 if (sctx->is_dev_replace &&
2377 atomic_read(&sctx->wr_ctx.flush_all_writes)) {
2378 mutex_lock(&sctx->wr_ctx.wr_lock);
2379 scrub_wr_submit(sctx);
2380 mutex_unlock(&sctx->wr_ctx.wr_lock);
2381 }
2382
2383 scrub_pending_bio_dec(sctx);
2384}
2385
2386static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2387 unsigned long *bitmap,
2388 u64 start, u64 len)
2389{
2390 u32 offset;
2391 int nsectors;
2392 int sectorsize = sparity->sctx->fs_info->sectorsize;
2393
2394 if (len >= sparity->stripe_len) {
2395 bitmap_set(bitmap, 0, sparity->nsectors);
2396 return;
2397 }
2398
2399 start -= sparity->logic_start;
2400 start = div_u64_rem(start, sparity->stripe_len, &offset);
2401 offset /= sectorsize;
2402 nsectors = (int)len / sectorsize;
2403
2404 if (offset + nsectors <= sparity->nsectors) {
2405 bitmap_set(bitmap, offset, nsectors);
2406 return;
2407 }
2408
2409 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2410 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2411}
2412
2413static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2414 u64 start, u64 len)
2415{
2416 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2417}
2418
2419static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2420 u64 start, u64 len)
2421{
2422 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2423}
2424
2425static void scrub_block_complete(struct scrub_block *sblock)
2426{
2427 int corrupted = 0;
2428
2429 if (!sblock->no_io_error_seen) {
2430 corrupted = 1;
2431 scrub_handle_errored_block(sblock);
2432 } else {
2433 /*
2434 * if has checksum error, write via repair mechanism in
2435 * dev replace case, otherwise write here in dev replace
2436 * case.
2437 */
2438 corrupted = scrub_checksum(sblock);
2439 if (!corrupted && sblock->sctx->is_dev_replace)
2440 scrub_write_block_to_dev_replace(sblock);
2441 }
2442
2443 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2444 u64 start = sblock->pagev[0]->logical;
2445 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2446 PAGE_SIZE;
2447
2448 scrub_parity_mark_sectors_error(sblock->sparity,
2449 start, end - start);
2450 }
2451}
2452
2453static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2454{
2455 struct btrfs_ordered_sum *sum = NULL;
2456 unsigned long index;
2457 unsigned long num_sectors;
2458
2459 while (!list_empty(&sctx->csum_list)) {
2460 sum = list_first_entry(&sctx->csum_list,
2461 struct btrfs_ordered_sum, list);
2462 if (sum->bytenr > logical)
2463 return 0;
2464 if (sum->bytenr + sum->len > logical)
2465 break;
2466
2467 ++sctx->stat.csum_discards;
2468 list_del(&sum->list);
2469 kfree(sum);
2470 sum = NULL;
2471 }
2472 if (!sum)
2473 return 0;
2474
2475 index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
2476 num_sectors = sum->len / sctx->sectorsize;
2477 memcpy(csum, sum->sums + index, sctx->csum_size);
2478 if (index == num_sectors - 1) {
2479 list_del(&sum->list);
2480 kfree(sum);
2481 }
2482 return 1;
2483}
2484
2485/* scrub extent tries to collect up to 64 kB for each bio */
2486static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
2487 u64 physical, struct btrfs_device *dev, u64 flags,
2488 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2489{
2490 int ret;
2491 u8 csum[BTRFS_CSUM_SIZE];
2492 u32 blocksize;
2493
2494 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2495 blocksize = sctx->sectorsize;
2496 spin_lock(&sctx->stat_lock);
2497 sctx->stat.data_extents_scrubbed++;
2498 sctx->stat.data_bytes_scrubbed += len;
2499 spin_unlock(&sctx->stat_lock);
2500 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2501 blocksize = sctx->nodesize;
2502 spin_lock(&sctx->stat_lock);
2503 sctx->stat.tree_extents_scrubbed++;
2504 sctx->stat.tree_bytes_scrubbed += len;
2505 spin_unlock(&sctx->stat_lock);
2506 } else {
2507 blocksize = sctx->sectorsize;
2508 WARN_ON(1);
2509 }
2510
2511 while (len) {
2512 u64 l = min_t(u64, len, blocksize);
2513 int have_csum = 0;
2514
2515 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2516 /* push csums to sbio */
2517 have_csum = scrub_find_csum(sctx, logical, csum);
2518 if (have_csum == 0)
2519 ++sctx->stat.no_csum;
2520 if (sctx->is_dev_replace && !have_csum) {
2521 ret = copy_nocow_pages(sctx, logical, l,
2522 mirror_num,
2523 physical_for_dev_replace);
2524 goto behind_scrub_pages;
2525 }
2526 }
2527 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2528 mirror_num, have_csum ? csum : NULL, 0,
2529 physical_for_dev_replace);
2530behind_scrub_pages:
2531 if (ret)
2532 return ret;
2533 len -= l;
2534 logical += l;
2535 physical += l;
2536 physical_for_dev_replace += l;
2537 }
2538 return 0;
2539}
2540
2541static int scrub_pages_for_parity(struct scrub_parity *sparity,
2542 u64 logical, u64 len,
2543 u64 physical, struct btrfs_device *dev,
2544 u64 flags, u64 gen, int mirror_num, u8 *csum)
2545{
2546 struct scrub_ctx *sctx = sparity->sctx;
2547 struct scrub_block *sblock;
2548 int index;
2549
2550 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2551 if (!sblock) {
2552 spin_lock(&sctx->stat_lock);
2553 sctx->stat.malloc_errors++;
2554 spin_unlock(&sctx->stat_lock);
2555 return -ENOMEM;
2556 }
2557
2558 /* one ref inside this function, plus one for each page added to
2559 * a bio later on */
2560 atomic_set(&sblock->refs, 1);
2561 sblock->sctx = sctx;
2562 sblock->no_io_error_seen = 1;
2563 sblock->sparity = sparity;
2564 scrub_parity_get(sparity);
2565
2566 for (index = 0; len > 0; index++) {
2567 struct scrub_page *spage;
2568 u64 l = min_t(u64, len, PAGE_SIZE);
2569
2570 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2571 if (!spage) {
2572leave_nomem:
2573 spin_lock(&sctx->stat_lock);
2574 sctx->stat.malloc_errors++;
2575 spin_unlock(&sctx->stat_lock);
2576 scrub_block_put(sblock);
2577 return -ENOMEM;
2578 }
2579 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2580 /* For scrub block */
2581 scrub_page_get(spage);
2582 sblock->pagev[index] = spage;
2583 /* For scrub parity */
2584 scrub_page_get(spage);
2585 list_add_tail(&spage->list, &sparity->spages);
2586 spage->sblock = sblock;
2587 spage->dev = dev;
2588 spage->flags = flags;
2589 spage->generation = gen;
2590 spage->logical = logical;
2591 spage->physical = physical;
2592 spage->mirror_num = mirror_num;
2593 if (csum) {
2594 spage->have_csum = 1;
2595 memcpy(spage->csum, csum, sctx->csum_size);
2596 } else {
2597 spage->have_csum = 0;
2598 }
2599 sblock->page_count++;
2600 spage->page = alloc_page(GFP_KERNEL);
2601 if (!spage->page)
2602 goto leave_nomem;
2603 len -= l;
2604 logical += l;
2605 physical += l;
2606 }
2607
2608 WARN_ON(sblock->page_count == 0);
2609 for (index = 0; index < sblock->page_count; index++) {
2610 struct scrub_page *spage = sblock->pagev[index];
2611 int ret;
2612
2613 ret = scrub_add_page_to_rd_bio(sctx, spage);
2614 if (ret) {
2615 scrub_block_put(sblock);
2616 return ret;
2617 }
2618 }
2619
2620 /* last one frees, either here or in bio completion for last page */
2621 scrub_block_put(sblock);
2622 return 0;
2623}
2624
2625static int scrub_extent_for_parity(struct scrub_parity *sparity,
2626 u64 logical, u64 len,
2627 u64 physical, struct btrfs_device *dev,
2628 u64 flags, u64 gen, int mirror_num)
2629{
2630 struct scrub_ctx *sctx = sparity->sctx;
2631 int ret;
2632 u8 csum[BTRFS_CSUM_SIZE];
2633 u32 blocksize;
2634
2635 if (dev->missing) {
2636 scrub_parity_mark_sectors_error(sparity, logical, len);
2637 return 0;
2638 }
2639
2640 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2641 blocksize = sctx->sectorsize;
2642 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2643 blocksize = sctx->nodesize;
2644 } else {
2645 blocksize = sctx->sectorsize;
2646 WARN_ON(1);
2647 }
2648
2649 while (len) {
2650 u64 l = min_t(u64, len, blocksize);
2651 int have_csum = 0;
2652
2653 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2654 /* push csums to sbio */
2655 have_csum = scrub_find_csum(sctx, logical, csum);
2656 if (have_csum == 0)
2657 goto skip;
2658 }
2659 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2660 flags, gen, mirror_num,
2661 have_csum ? csum : NULL);
2662 if (ret)
2663 return ret;
2664skip:
2665 len -= l;
2666 logical += l;
2667 physical += l;
2668 }
2669 return 0;
2670}
2671
2672/*
2673 * Given a physical address, this will calculate it's
2674 * logical offset. if this is a parity stripe, it will return
2675 * the most left data stripe's logical offset.
2676 *
2677 * return 0 if it is a data stripe, 1 means parity stripe.
2678 */
2679static int get_raid56_logic_offset(u64 physical, int num,
2680 struct map_lookup *map, u64 *offset,
2681 u64 *stripe_start)
2682{
2683 int i;
2684 int j = 0;
2685 u64 stripe_nr;
2686 u64 last_offset;
2687 u32 stripe_index;
2688 u32 rot;
2689
2690 last_offset = (physical - map->stripes[num].physical) *
2691 nr_data_stripes(map);
2692 if (stripe_start)
2693 *stripe_start = last_offset;
2694
2695 *offset = last_offset;
2696 for (i = 0; i < nr_data_stripes(map); i++) {
2697 *offset = last_offset + i * map->stripe_len;
2698
2699 stripe_nr = div_u64(*offset, map->stripe_len);
2700 stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
2701
2702 /* Work out the disk rotation on this stripe-set */
2703 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2704 /* calculate which stripe this data locates */
2705 rot += i;
2706 stripe_index = rot % map->num_stripes;
2707 if (stripe_index == num)
2708 return 0;
2709 if (stripe_index < num)
2710 j++;
2711 }
2712 *offset = last_offset + j * map->stripe_len;
2713 return 1;
2714}
2715
2716static void scrub_free_parity(struct scrub_parity *sparity)
2717{
2718 struct scrub_ctx *sctx = sparity->sctx;
2719 struct scrub_page *curr, *next;
2720 int nbits;
2721
2722 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2723 if (nbits) {
2724 spin_lock(&sctx->stat_lock);
2725 sctx->stat.read_errors += nbits;
2726 sctx->stat.uncorrectable_errors += nbits;
2727 spin_unlock(&sctx->stat_lock);
2728 }
2729
2730 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2731 list_del_init(&curr->list);
2732 scrub_page_put(curr);
2733 }
2734
2735 kfree(sparity);
2736}
2737
2738static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2739{
2740 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2741 work);
2742 struct scrub_ctx *sctx = sparity->sctx;
2743
2744 scrub_free_parity(sparity);
2745 scrub_pending_bio_dec(sctx);
2746}
2747
2748static void scrub_parity_bio_endio(struct bio *bio)
2749{
2750 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2751 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2752
2753 if (bio->bi_error)
2754 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2755 sparity->nsectors);
2756
2757 bio_put(bio);
2758
2759 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2760 scrub_parity_bio_endio_worker, NULL, NULL);
2761 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2762}
2763
2764static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2765{
2766 struct scrub_ctx *sctx = sparity->sctx;
2767 struct btrfs_fs_info *fs_info = sctx->fs_info;
2768 struct bio *bio;
2769 struct btrfs_raid_bio *rbio;
2770 struct scrub_page *spage;
2771 struct btrfs_bio *bbio = NULL;
2772 u64 length;
2773 int ret;
2774
2775 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2776 sparity->nsectors))
2777 goto out;
2778
2779 length = sparity->logic_end - sparity->logic_start;
2780 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2781 &length, &bbio, 0, 1);
2782 if (ret || !bbio || !bbio->raid_map)
2783 goto bbio_out;
2784
2785 bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
2786 if (!bio)
2787 goto bbio_out;
2788
2789 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2790 bio->bi_private = sparity;
2791 bio->bi_end_io = scrub_parity_bio_endio;
2792
2793 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2794 length, sparity->scrub_dev,
2795 sparity->dbitmap,
2796 sparity->nsectors);
2797 if (!rbio)
2798 goto rbio_out;
2799
2800 list_for_each_entry(spage, &sparity->spages, list)
2801 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2802
2803 scrub_pending_bio_inc(sctx);
2804 raid56_parity_submit_scrub_rbio(rbio);
2805 return;
2806
2807rbio_out:
2808 bio_put(bio);
2809bbio_out:
2810 btrfs_put_bbio(bbio);
2811 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2812 sparity->nsectors);
2813 spin_lock(&sctx->stat_lock);
2814 sctx->stat.malloc_errors++;
2815 spin_unlock(&sctx->stat_lock);
2816out:
2817 scrub_free_parity(sparity);
2818}
2819
2820static inline int scrub_calc_parity_bitmap_len(int nsectors)
2821{
2822 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2823}
2824
2825static void scrub_parity_get(struct scrub_parity *sparity)
2826{
2827 atomic_inc(&sparity->refs);
2828}
2829
2830static void scrub_parity_put(struct scrub_parity *sparity)
2831{
2832 if (!atomic_dec_and_test(&sparity->refs))
2833 return;
2834
2835 scrub_parity_check_and_repair(sparity);
2836}
2837
2838static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2839 struct map_lookup *map,
2840 struct btrfs_device *sdev,
2841 struct btrfs_path *path,
2842 u64 logic_start,
2843 u64 logic_end)
2844{
2845 struct btrfs_fs_info *fs_info = sctx->fs_info;
2846 struct btrfs_root *root = fs_info->extent_root;
2847 struct btrfs_root *csum_root = fs_info->csum_root;
2848 struct btrfs_extent_item *extent;
2849 struct btrfs_bio *bbio = NULL;
2850 u64 flags;
2851 int ret;
2852 int slot;
2853 struct extent_buffer *l;
2854 struct btrfs_key key;
2855 u64 generation;
2856 u64 extent_logical;
2857 u64 extent_physical;
2858 u64 extent_len;
2859 u64 mapped_length;
2860 struct btrfs_device *extent_dev;
2861 struct scrub_parity *sparity;
2862 int nsectors;
2863 int bitmap_len;
2864 int extent_mirror_num;
2865 int stop_loop = 0;
2866
2867 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2868 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2869 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2870 GFP_NOFS);
2871 if (!sparity) {
2872 spin_lock(&sctx->stat_lock);
2873 sctx->stat.malloc_errors++;
2874 spin_unlock(&sctx->stat_lock);
2875 return -ENOMEM;
2876 }
2877
2878 sparity->stripe_len = map->stripe_len;
2879 sparity->nsectors = nsectors;
2880 sparity->sctx = sctx;
2881 sparity->scrub_dev = sdev;
2882 sparity->logic_start = logic_start;
2883 sparity->logic_end = logic_end;
2884 atomic_set(&sparity->refs, 1);
2885 INIT_LIST_HEAD(&sparity->spages);
2886 sparity->dbitmap = sparity->bitmap;
2887 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2888
2889 ret = 0;
2890 while (logic_start < logic_end) {
2891 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2892 key.type = BTRFS_METADATA_ITEM_KEY;
2893 else
2894 key.type = BTRFS_EXTENT_ITEM_KEY;
2895 key.objectid = logic_start;
2896 key.offset = (u64)-1;
2897
2898 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2899 if (ret < 0)
2900 goto out;
2901
2902 if (ret > 0) {
2903 ret = btrfs_previous_extent_item(root, path, 0);
2904 if (ret < 0)
2905 goto out;
2906 if (ret > 0) {
2907 btrfs_release_path(path);
2908 ret = btrfs_search_slot(NULL, root, &key,
2909 path, 0, 0);
2910 if (ret < 0)
2911 goto out;
2912 }
2913 }
2914
2915 stop_loop = 0;
2916 while (1) {
2917 u64 bytes;
2918
2919 l = path->nodes[0];
2920 slot = path->slots[0];
2921 if (slot >= btrfs_header_nritems(l)) {
2922 ret = btrfs_next_leaf(root, path);
2923 if (ret == 0)
2924 continue;
2925 if (ret < 0)
2926 goto out;
2927
2928 stop_loop = 1;
2929 break;
2930 }
2931 btrfs_item_key_to_cpu(l, &key, slot);
2932
2933 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2934 key.type != BTRFS_METADATA_ITEM_KEY)
2935 goto next;
2936
2937 if (key.type == BTRFS_METADATA_ITEM_KEY)
2938 bytes = fs_info->nodesize;
2939 else
2940 bytes = key.offset;
2941
2942 if (key.objectid + bytes <= logic_start)
2943 goto next;
2944
2945 if (key.objectid >= logic_end) {
2946 stop_loop = 1;
2947 break;
2948 }
2949
2950 while (key.objectid >= logic_start + map->stripe_len)
2951 logic_start += map->stripe_len;
2952
2953 extent = btrfs_item_ptr(l, slot,
2954 struct btrfs_extent_item);
2955 flags = btrfs_extent_flags(l, extent);
2956 generation = btrfs_extent_generation(l, extent);
2957
2958 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2959 (key.objectid < logic_start ||
2960 key.objectid + bytes >
2961 logic_start + map->stripe_len)) {
2962 btrfs_err(fs_info,
2963 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2964 key.objectid, logic_start);
2965 spin_lock(&sctx->stat_lock);
2966 sctx->stat.uncorrectable_errors++;
2967 spin_unlock(&sctx->stat_lock);
2968 goto next;
2969 }
2970again:
2971 extent_logical = key.objectid;
2972 extent_len = bytes;
2973
2974 if (extent_logical < logic_start) {
2975 extent_len -= logic_start - extent_logical;
2976 extent_logical = logic_start;
2977 }
2978
2979 if (extent_logical + extent_len >
2980 logic_start + map->stripe_len)
2981 extent_len = logic_start + map->stripe_len -
2982 extent_logical;
2983
2984 scrub_parity_mark_sectors_data(sparity, extent_logical,
2985 extent_len);
2986
2987 mapped_length = extent_len;
2988 bbio = NULL;
2989 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2990 extent_logical, &mapped_length, &bbio,
2991 0);
2992 if (!ret) {
2993 if (!bbio || mapped_length < extent_len)
2994 ret = -EIO;
2995 }
2996 if (ret) {
2997 btrfs_put_bbio(bbio);
2998 goto out;
2999 }
3000 extent_physical = bbio->stripes[0].physical;
3001 extent_mirror_num = bbio->mirror_num;
3002 extent_dev = bbio->stripes[0].dev;
3003 btrfs_put_bbio(bbio);
3004
3005 ret = btrfs_lookup_csums_range(csum_root,
3006 extent_logical,
3007 extent_logical + extent_len - 1,
3008 &sctx->csum_list, 1);
3009 if (ret)
3010 goto out;
3011
3012 ret = scrub_extent_for_parity(sparity, extent_logical,
3013 extent_len,
3014 extent_physical,
3015 extent_dev, flags,
3016 generation,
3017 extent_mirror_num);
3018
3019 scrub_free_csums(sctx);
3020
3021 if (ret)
3022 goto out;
3023
3024 if (extent_logical + extent_len <
3025 key.objectid + bytes) {
3026 logic_start += map->stripe_len;
3027
3028 if (logic_start >= logic_end) {
3029 stop_loop = 1;
3030 break;
3031 }
3032
3033 if (logic_start < key.objectid + bytes) {
3034 cond_resched();
3035 goto again;
3036 }
3037 }
3038next:
3039 path->slots[0]++;
3040 }
3041
3042 btrfs_release_path(path);
3043
3044 if (stop_loop)
3045 break;
3046
3047 logic_start += map->stripe_len;
3048 }
3049out:
3050 if (ret < 0)
3051 scrub_parity_mark_sectors_error(sparity, logic_start,
3052 logic_end - logic_start);
3053 scrub_parity_put(sparity);
3054 scrub_submit(sctx);
3055 mutex_lock(&sctx->wr_ctx.wr_lock);
3056 scrub_wr_submit(sctx);
3057 mutex_unlock(&sctx->wr_ctx.wr_lock);
3058
3059 btrfs_release_path(path);
3060 return ret < 0 ? ret : 0;
3061}
3062
3063static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3064 struct map_lookup *map,
3065 struct btrfs_device *scrub_dev,
3066 int num, u64 base, u64 length,
3067 int is_dev_replace)
3068{
3069 struct btrfs_path *path, *ppath;
3070 struct btrfs_fs_info *fs_info = sctx->fs_info;
3071 struct btrfs_root *root = fs_info->extent_root;
3072 struct btrfs_root *csum_root = fs_info->csum_root;
3073 struct btrfs_extent_item *extent;
3074 struct blk_plug plug;
3075 u64 flags;
3076 int ret;
3077 int slot;
3078 u64 nstripes;
3079 struct extent_buffer *l;
3080 u64 physical;
3081 u64 logical;
3082 u64 logic_end;
3083 u64 physical_end;
3084 u64 generation;
3085 int mirror_num;
3086 struct reada_control *reada1;
3087 struct reada_control *reada2;
3088 struct btrfs_key key;
3089 struct btrfs_key key_end;
3090 u64 increment = map->stripe_len;
3091 u64 offset;
3092 u64 extent_logical;
3093 u64 extent_physical;
3094 u64 extent_len;
3095 u64 stripe_logical;
3096 u64 stripe_end;
3097 struct btrfs_device *extent_dev;
3098 int extent_mirror_num;
3099 int stop_loop = 0;
3100
3101 physical = map->stripes[num].physical;
3102 offset = 0;
3103 nstripes = div_u64(length, map->stripe_len);
3104 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3105 offset = map->stripe_len * num;
3106 increment = map->stripe_len * map->num_stripes;
3107 mirror_num = 1;
3108 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3109 int factor = map->num_stripes / map->sub_stripes;
3110 offset = map->stripe_len * (num / map->sub_stripes);
3111 increment = map->stripe_len * factor;
3112 mirror_num = num % map->sub_stripes + 1;
3113 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3114 increment = map->stripe_len;
3115 mirror_num = num % map->num_stripes + 1;
3116 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3117 increment = map->stripe_len;
3118 mirror_num = num % map->num_stripes + 1;
3119 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3120 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3121 increment = map->stripe_len * nr_data_stripes(map);
3122 mirror_num = 1;
3123 } else {
3124 increment = map->stripe_len;
3125 mirror_num = 1;
3126 }
3127
3128 path = btrfs_alloc_path();
3129 if (!path)
3130 return -ENOMEM;
3131
3132 ppath = btrfs_alloc_path();
3133 if (!ppath) {
3134 btrfs_free_path(path);
3135 return -ENOMEM;
3136 }
3137
3138 /*
3139 * work on commit root. The related disk blocks are static as
3140 * long as COW is applied. This means, it is save to rewrite
3141 * them to repair disk errors without any race conditions
3142 */
3143 path->search_commit_root = 1;
3144 path->skip_locking = 1;
3145
3146 ppath->search_commit_root = 1;
3147 ppath->skip_locking = 1;
3148 /*
3149 * trigger the readahead for extent tree csum tree and wait for
3150 * completion. During readahead, the scrub is officially paused
3151 * to not hold off transaction commits
3152 */
3153 logical = base + offset;
3154 physical_end = physical + nstripes * map->stripe_len;
3155 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3156 get_raid56_logic_offset(physical_end, num,
3157 map, &logic_end, NULL);
3158 logic_end += base;
3159 } else {
3160 logic_end = logical + increment * nstripes;
3161 }
3162 wait_event(sctx->list_wait,
3163 atomic_read(&sctx->bios_in_flight) == 0);
3164 scrub_blocked_if_needed(fs_info);
3165
3166 /* FIXME it might be better to start readahead at commit root */
3167 key.objectid = logical;
3168 key.type = BTRFS_EXTENT_ITEM_KEY;
3169 key.offset = (u64)0;
3170 key_end.objectid = logic_end;
3171 key_end.type = BTRFS_METADATA_ITEM_KEY;
3172 key_end.offset = (u64)-1;
3173 reada1 = btrfs_reada_add(root, &key, &key_end);
3174
3175 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3176 key.type = BTRFS_EXTENT_CSUM_KEY;
3177 key.offset = logical;
3178 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3179 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3180 key_end.offset = logic_end;
3181 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3182
3183 if (!IS_ERR(reada1))
3184 btrfs_reada_wait(reada1);
3185 if (!IS_ERR(reada2))
3186 btrfs_reada_wait(reada2);
3187
3188
3189 /*
3190 * collect all data csums for the stripe to avoid seeking during
3191 * the scrub. This might currently (crc32) end up to be about 1MB
3192 */
3193 blk_start_plug(&plug);
3194
3195 /*
3196 * now find all extents for each stripe and scrub them
3197 */
3198 ret = 0;
3199 while (physical < physical_end) {
3200 /*
3201 * canceled?
3202 */
3203 if (atomic_read(&fs_info->scrub_cancel_req) ||
3204 atomic_read(&sctx->cancel_req)) {
3205 ret = -ECANCELED;
3206 goto out;
3207 }
3208 /*
3209 * check to see if we have to pause
3210 */
3211 if (atomic_read(&fs_info->scrub_pause_req)) {
3212 /* push queued extents */
3213 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3214 scrub_submit(sctx);
3215 mutex_lock(&sctx->wr_ctx.wr_lock);
3216 scrub_wr_submit(sctx);
3217 mutex_unlock(&sctx->wr_ctx.wr_lock);
3218 wait_event(sctx->list_wait,
3219 atomic_read(&sctx->bios_in_flight) == 0);
3220 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3221 scrub_blocked_if_needed(fs_info);
3222 }
3223
3224 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3225 ret = get_raid56_logic_offset(physical, num, map,
3226 &logical,
3227 &stripe_logical);
3228 logical += base;
3229 if (ret) {
3230 /* it is parity strip */
3231 stripe_logical += base;
3232 stripe_end = stripe_logical + increment;
3233 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3234 ppath, stripe_logical,
3235 stripe_end);
3236 if (ret)
3237 goto out;
3238 goto skip;
3239 }
3240 }
3241
3242 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3243 key.type = BTRFS_METADATA_ITEM_KEY;
3244 else
3245 key.type = BTRFS_EXTENT_ITEM_KEY;
3246 key.objectid = logical;
3247 key.offset = (u64)-1;
3248
3249 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3250 if (ret < 0)
3251 goto out;
3252
3253 if (ret > 0) {
3254 ret = btrfs_previous_extent_item(root, path, 0);
3255 if (ret < 0)
3256 goto out;
3257 if (ret > 0) {
3258 /* there's no smaller item, so stick with the
3259 * larger one */
3260 btrfs_release_path(path);
3261 ret = btrfs_search_slot(NULL, root, &key,
3262 path, 0, 0);
3263 if (ret < 0)
3264 goto out;
3265 }
3266 }
3267
3268 stop_loop = 0;
3269 while (1) {
3270 u64 bytes;
3271
3272 l = path->nodes[0];
3273 slot = path->slots[0];
3274 if (slot >= btrfs_header_nritems(l)) {
3275 ret = btrfs_next_leaf(root, path);
3276 if (ret == 0)
3277 continue;
3278 if (ret < 0)
3279 goto out;
3280
3281 stop_loop = 1;
3282 break;
3283 }
3284 btrfs_item_key_to_cpu(l, &key, slot);
3285
3286 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3287 key.type != BTRFS_METADATA_ITEM_KEY)
3288 goto next;
3289
3290 if (key.type == BTRFS_METADATA_ITEM_KEY)
3291 bytes = fs_info->nodesize;
3292 else
3293 bytes = key.offset;
3294
3295 if (key.objectid + bytes <= logical)
3296 goto next;
3297
3298 if (key.objectid >= logical + map->stripe_len) {
3299 /* out of this device extent */
3300 if (key.objectid >= logic_end)
3301 stop_loop = 1;
3302 break;
3303 }
3304
3305 extent = btrfs_item_ptr(l, slot,
3306 struct btrfs_extent_item);
3307 flags = btrfs_extent_flags(l, extent);
3308 generation = btrfs_extent_generation(l, extent);
3309
3310 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3311 (key.objectid < logical ||
3312 key.objectid + bytes >
3313 logical + map->stripe_len)) {
3314 btrfs_err(fs_info,
3315 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3316 key.objectid, logical);
3317 spin_lock(&sctx->stat_lock);
3318 sctx->stat.uncorrectable_errors++;
3319 spin_unlock(&sctx->stat_lock);
3320 goto next;
3321 }
3322
3323again:
3324 extent_logical = key.objectid;
3325 extent_len = bytes;
3326
3327 /*
3328 * trim extent to this stripe
3329 */
3330 if (extent_logical < logical) {
3331 extent_len -= logical - extent_logical;
3332 extent_logical = logical;
3333 }
3334 if (extent_logical + extent_len >
3335 logical + map->stripe_len) {
3336 extent_len = logical + map->stripe_len -
3337 extent_logical;
3338 }
3339
3340 extent_physical = extent_logical - logical + physical;
3341 extent_dev = scrub_dev;
3342 extent_mirror_num = mirror_num;
3343 if (is_dev_replace)
3344 scrub_remap_extent(fs_info, extent_logical,
3345 extent_len, &extent_physical,
3346 &extent_dev,
3347 &extent_mirror_num);
3348
3349 ret = btrfs_lookup_csums_range(csum_root,
3350 extent_logical,
3351 extent_logical +
3352 extent_len - 1,
3353 &sctx->csum_list, 1);
3354 if (ret)
3355 goto out;
3356
3357 ret = scrub_extent(sctx, extent_logical, extent_len,
3358 extent_physical, extent_dev, flags,
3359 generation, extent_mirror_num,
3360 extent_logical - logical + physical);
3361
3362 scrub_free_csums(sctx);
3363
3364 if (ret)
3365 goto out;
3366
3367 if (extent_logical + extent_len <
3368 key.objectid + bytes) {
3369 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3370 /*
3371 * loop until we find next data stripe
3372 * or we have finished all stripes.
3373 */
3374loop:
3375 physical += map->stripe_len;
3376 ret = get_raid56_logic_offset(physical,
3377 num, map, &logical,
3378 &stripe_logical);
3379 logical += base;
3380
3381 if (ret && physical < physical_end) {
3382 stripe_logical += base;
3383 stripe_end = stripe_logical +
3384 increment;
3385 ret = scrub_raid56_parity(sctx,
3386 map, scrub_dev, ppath,
3387 stripe_logical,
3388 stripe_end);
3389 if (ret)
3390 goto out;
3391 goto loop;
3392 }
3393 } else {
3394 physical += map->stripe_len;
3395 logical += increment;
3396 }
3397 if (logical < key.objectid + bytes) {
3398 cond_resched();
3399 goto again;
3400 }
3401
3402 if (physical >= physical_end) {
3403 stop_loop = 1;
3404 break;
3405 }
3406 }
3407next:
3408 path->slots[0]++;
3409 }
3410 btrfs_release_path(path);
3411skip:
3412 logical += increment;
3413 physical += map->stripe_len;
3414 spin_lock(&sctx->stat_lock);
3415 if (stop_loop)
3416 sctx->stat.last_physical = map->stripes[num].physical +
3417 length;
3418 else
3419 sctx->stat.last_physical = physical;
3420 spin_unlock(&sctx->stat_lock);
3421 if (stop_loop)
3422 break;
3423 }
3424out:
3425 /* push queued extents */
3426 scrub_submit(sctx);
3427 mutex_lock(&sctx->wr_ctx.wr_lock);
3428 scrub_wr_submit(sctx);
3429 mutex_unlock(&sctx->wr_ctx.wr_lock);
3430
3431 blk_finish_plug(&plug);
3432 btrfs_free_path(path);
3433 btrfs_free_path(ppath);
3434 return ret < 0 ? ret : 0;
3435}
3436
3437static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3438 struct btrfs_device *scrub_dev,
3439 u64 chunk_offset, u64 length,
3440 u64 dev_offset,
3441 struct btrfs_block_group_cache *cache,
3442 int is_dev_replace)
3443{
3444 struct btrfs_fs_info *fs_info = sctx->fs_info;
3445 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
3446 struct map_lookup *map;
3447 struct extent_map *em;
3448 int i;
3449 int ret = 0;
3450
3451 read_lock(&map_tree->map_tree.lock);
3452 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3453 read_unlock(&map_tree->map_tree.lock);
3454
3455 if (!em) {
3456 /*
3457 * Might have been an unused block group deleted by the cleaner
3458 * kthread or relocation.
3459 */
3460 spin_lock(&cache->lock);
3461 if (!cache->removed)
3462 ret = -EINVAL;
3463 spin_unlock(&cache->lock);
3464
3465 return ret;
3466 }
3467
3468 map = em->map_lookup;
3469 if (em->start != chunk_offset)
3470 goto out;
3471
3472 if (em->len < length)
3473 goto out;
3474
3475 for (i = 0; i < map->num_stripes; ++i) {
3476 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3477 map->stripes[i].physical == dev_offset) {
3478 ret = scrub_stripe(sctx, map, scrub_dev, i,
3479 chunk_offset, length,
3480 is_dev_replace);
3481 if (ret)
3482 goto out;
3483 }
3484 }
3485out:
3486 free_extent_map(em);
3487
3488 return ret;
3489}
3490
3491static noinline_for_stack
3492int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3493 struct btrfs_device *scrub_dev, u64 start, u64 end,
3494 int is_dev_replace)
3495{
3496 struct btrfs_dev_extent *dev_extent = NULL;
3497 struct btrfs_path *path;
3498 struct btrfs_fs_info *fs_info = sctx->fs_info;
3499 struct btrfs_root *root = fs_info->dev_root;
3500 u64 length;
3501 u64 chunk_offset;
3502 int ret = 0;
3503 int ro_set;
3504 int slot;
3505 struct extent_buffer *l;
3506 struct btrfs_key key;
3507 struct btrfs_key found_key;
3508 struct btrfs_block_group_cache *cache;
3509 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3510
3511 path = btrfs_alloc_path();
3512 if (!path)
3513 return -ENOMEM;
3514
3515 path->reada = READA_FORWARD;
3516 path->search_commit_root = 1;
3517 path->skip_locking = 1;
3518
3519 key.objectid = scrub_dev->devid;
3520 key.offset = 0ull;
3521 key.type = BTRFS_DEV_EXTENT_KEY;
3522
3523 while (1) {
3524 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3525 if (ret < 0)
3526 break;
3527 if (ret > 0) {
3528 if (path->slots[0] >=
3529 btrfs_header_nritems(path->nodes[0])) {
3530 ret = btrfs_next_leaf(root, path);
3531 if (ret < 0)
3532 break;
3533 if (ret > 0) {
3534 ret = 0;
3535 break;
3536 }
3537 } else {
3538 ret = 0;
3539 }
3540 }
3541
3542 l = path->nodes[0];
3543 slot = path->slots[0];
3544
3545 btrfs_item_key_to_cpu(l, &found_key, slot);
3546
3547 if (found_key.objectid != scrub_dev->devid)
3548 break;
3549
3550 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3551 break;
3552
3553 if (found_key.offset >= end)
3554 break;
3555
3556 if (found_key.offset < key.offset)
3557 break;
3558
3559 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3560 length = btrfs_dev_extent_length(l, dev_extent);
3561
3562 if (found_key.offset + length <= start)
3563 goto skip;
3564
3565 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3566
3567 /*
3568 * get a reference on the corresponding block group to prevent
3569 * the chunk from going away while we scrub it
3570 */
3571 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3572
3573 /* some chunks are removed but not committed to disk yet,
3574 * continue scrubbing */
3575 if (!cache)
3576 goto skip;
3577
3578 /*
3579 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3580 * to avoid deadlock caused by:
3581 * btrfs_inc_block_group_ro()
3582 * -> btrfs_wait_for_commit()
3583 * -> btrfs_commit_transaction()
3584 * -> btrfs_scrub_pause()
3585 */
3586 scrub_pause_on(fs_info);
3587 ret = btrfs_inc_block_group_ro(root, cache);
3588 if (!ret && is_dev_replace) {
3589 /*
3590 * If we are doing a device replace wait for any tasks
3591 * that started dellaloc right before we set the block
3592 * group to RO mode, as they might have just allocated
3593 * an extent from it or decided they could do a nocow
3594 * write. And if any such tasks did that, wait for their
3595 * ordered extents to complete and then commit the
3596 * current transaction, so that we can later see the new
3597 * extent items in the extent tree - the ordered extents
3598 * create delayed data references (for cow writes) when
3599 * they complete, which will be run and insert the
3600 * corresponding extent items into the extent tree when
3601 * we commit the transaction they used when running
3602 * inode.c:btrfs_finish_ordered_io(). We later use
3603 * the commit root of the extent tree to find extents
3604 * to copy from the srcdev into the tgtdev, and we don't
3605 * want to miss any new extents.
3606 */
3607 btrfs_wait_block_group_reservations(cache);
3608 btrfs_wait_nocow_writers(cache);
3609 ret = btrfs_wait_ordered_roots(fs_info, -1,
3610 cache->key.objectid,
3611 cache->key.offset);
3612 if (ret > 0) {
3613 struct btrfs_trans_handle *trans;
3614
3615 trans = btrfs_join_transaction(root);
3616 if (IS_ERR(trans))
3617 ret = PTR_ERR(trans);
3618 else
3619 ret = btrfs_commit_transaction(trans);
3620 if (ret) {
3621 scrub_pause_off(fs_info);
3622 btrfs_put_block_group(cache);
3623 break;
3624 }
3625 }
3626 }
3627 scrub_pause_off(fs_info);
3628
3629 if (ret == 0) {
3630 ro_set = 1;
3631 } else if (ret == -ENOSPC) {
3632 /*
3633 * btrfs_inc_block_group_ro return -ENOSPC when it
3634 * failed in creating new chunk for metadata.
3635 * It is not a problem for scrub/replace, because
3636 * metadata are always cowed, and our scrub paused
3637 * commit_transactions.
3638 */
3639 ro_set = 0;
3640 } else {
3641 btrfs_warn(fs_info,
3642 "failed setting block group ro, ret=%d\n",
3643 ret);
3644 btrfs_put_block_group(cache);
3645 break;
3646 }
3647
3648 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3649 dev_replace->cursor_right = found_key.offset + length;
3650 dev_replace->cursor_left = found_key.offset;
3651 dev_replace->item_needs_writeback = 1;
3652 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3653 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3654 found_key.offset, cache, is_dev_replace);
3655
3656 /*
3657 * flush, submit all pending read and write bios, afterwards
3658 * wait for them.
3659 * Note that in the dev replace case, a read request causes
3660 * write requests that are submitted in the read completion
3661 * worker. Therefore in the current situation, it is required
3662 * that all write requests are flushed, so that all read and
3663 * write requests are really completed when bios_in_flight
3664 * changes to 0.
3665 */
3666 atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
3667 scrub_submit(sctx);
3668 mutex_lock(&sctx->wr_ctx.wr_lock);
3669 scrub_wr_submit(sctx);
3670 mutex_unlock(&sctx->wr_ctx.wr_lock);
3671
3672 wait_event(sctx->list_wait,
3673 atomic_read(&sctx->bios_in_flight) == 0);
3674
3675 scrub_pause_on(fs_info);
3676
3677 /*
3678 * must be called before we decrease @scrub_paused.
3679 * make sure we don't block transaction commit while
3680 * we are waiting pending workers finished.
3681 */
3682 wait_event(sctx->list_wait,
3683 atomic_read(&sctx->workers_pending) == 0);
3684 atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
3685
3686 scrub_pause_off(fs_info);
3687
3688 btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
3689 dev_replace->cursor_left = dev_replace->cursor_right;
3690 dev_replace->item_needs_writeback = 1;
3691 btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
3692
3693 if (ro_set)
3694 btrfs_dec_block_group_ro(cache);
3695
3696 /*
3697 * We might have prevented the cleaner kthread from deleting
3698 * this block group if it was already unused because we raced
3699 * and set it to RO mode first. So add it back to the unused
3700 * list, otherwise it might not ever be deleted unless a manual
3701 * balance is triggered or it becomes used and unused again.
3702 */
3703 spin_lock(&cache->lock);
3704 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3705 btrfs_block_group_used(&cache->item) == 0) {
3706 spin_unlock(&cache->lock);
3707 spin_lock(&fs_info->unused_bgs_lock);
3708 if (list_empty(&cache->bg_list)) {
3709 btrfs_get_block_group(cache);
3710 list_add_tail(&cache->bg_list,
3711 &fs_info->unused_bgs);
3712 }
3713 spin_unlock(&fs_info->unused_bgs_lock);
3714 } else {
3715 spin_unlock(&cache->lock);
3716 }
3717
3718 btrfs_put_block_group(cache);
3719 if (ret)
3720 break;
3721 if (is_dev_replace &&
3722 atomic64_read(&dev_replace->num_write_errors) > 0) {
3723 ret = -EIO;
3724 break;
3725 }
3726 if (sctx->stat.malloc_errors > 0) {
3727 ret = -ENOMEM;
3728 break;
3729 }
3730skip:
3731 key.offset = found_key.offset + length;
3732 btrfs_release_path(path);
3733 }
3734
3735 btrfs_free_path(path);
3736
3737 return ret;
3738}
3739
3740static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3741 struct btrfs_device *scrub_dev)
3742{
3743 int i;
3744 u64 bytenr;
3745 u64 gen;
3746 int ret;
3747 struct btrfs_fs_info *fs_info = sctx->fs_info;
3748
3749 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3750 return -EIO;
3751
3752 /* Seed devices of a new filesystem has their own generation. */
3753 if (scrub_dev->fs_devices != fs_info->fs_devices)
3754 gen = scrub_dev->generation;
3755 else
3756 gen = fs_info->last_trans_committed;
3757
3758 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3759 bytenr = btrfs_sb_offset(i);
3760 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3761 scrub_dev->commit_total_bytes)
3762 break;
3763
3764 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3765 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3766 NULL, 1, bytenr);
3767 if (ret)
3768 return ret;
3769 }
3770 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3771
3772 return 0;
3773}
3774
3775/*
3776 * get a reference count on fs_info->scrub_workers. start worker if necessary
3777 */
3778static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3779 int is_dev_replace)
3780{
3781 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3782 int max_active = fs_info->thread_pool_size;
3783
3784 if (fs_info->scrub_workers_refcnt == 0) {
3785 if (is_dev_replace)
3786 fs_info->scrub_workers =
3787 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3788 1, 4);
3789 else
3790 fs_info->scrub_workers =
3791 btrfs_alloc_workqueue(fs_info, "scrub", flags,
3792 max_active, 4);
3793 if (!fs_info->scrub_workers)
3794 goto fail_scrub_workers;
3795
3796 fs_info->scrub_wr_completion_workers =
3797 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3798 max_active, 2);
3799 if (!fs_info->scrub_wr_completion_workers)
3800 goto fail_scrub_wr_completion_workers;
3801
3802 fs_info->scrub_nocow_workers =
3803 btrfs_alloc_workqueue(fs_info, "scrubnc", flags, 1, 0);
3804 if (!fs_info->scrub_nocow_workers)
3805 goto fail_scrub_nocow_workers;
3806 fs_info->scrub_parity_workers =
3807 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3808 max_active, 2);
3809 if (!fs_info->scrub_parity_workers)
3810 goto fail_scrub_parity_workers;
3811 }
3812 ++fs_info->scrub_workers_refcnt;
3813 return 0;
3814
3815fail_scrub_parity_workers:
3816 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3817fail_scrub_nocow_workers:
3818 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3819fail_scrub_wr_completion_workers:
3820 btrfs_destroy_workqueue(fs_info->scrub_workers);
3821fail_scrub_workers:
3822 return -ENOMEM;
3823}
3824
3825static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
3826{
3827 if (--fs_info->scrub_workers_refcnt == 0) {
3828 btrfs_destroy_workqueue(fs_info->scrub_workers);
3829 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3830 btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
3831 btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
3832 }
3833 WARN_ON(fs_info->scrub_workers_refcnt < 0);
3834}
3835
3836int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3837 u64 end, struct btrfs_scrub_progress *progress,
3838 int readonly, int is_dev_replace)
3839{
3840 struct scrub_ctx *sctx;
3841 int ret;
3842 struct btrfs_device *dev;
3843 struct rcu_string *name;
3844
3845 if (btrfs_fs_closing(fs_info))
3846 return -EINVAL;
3847
3848 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3849 /*
3850 * in this case scrub is unable to calculate the checksum
3851 * the way scrub is implemented. Do not handle this
3852 * situation at all because it won't ever happen.
3853 */
3854 btrfs_err(fs_info,
3855 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3856 fs_info->nodesize,
3857 BTRFS_STRIPE_LEN);
3858 return -EINVAL;
3859 }
3860
3861 if (fs_info->sectorsize != PAGE_SIZE) {
3862 /* not supported for data w/o checksums */
3863 btrfs_err_rl(fs_info,
3864 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3865 fs_info->sectorsize, PAGE_SIZE);
3866 return -EINVAL;
3867 }
3868
3869 if (fs_info->nodesize >
3870 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3871 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3872 /*
3873 * would exhaust the array bounds of pagev member in
3874 * struct scrub_block
3875 */
3876 btrfs_err(fs_info,
3877 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3878 fs_info->nodesize,
3879 SCRUB_MAX_PAGES_PER_BLOCK,
3880 fs_info->sectorsize,
3881 SCRUB_MAX_PAGES_PER_BLOCK);
3882 return -EINVAL;
3883 }
3884
3885
3886 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3887 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
3888 if (!dev || (dev->missing && !is_dev_replace)) {
3889 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3890 return -ENODEV;
3891 }
3892
3893 if (!is_dev_replace && !readonly && !dev->writeable) {
3894 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3895 rcu_read_lock();
3896 name = rcu_dereference(dev->name);
3897 btrfs_err(fs_info, "scrub: device %s is not writable",
3898 name->str);
3899 rcu_read_unlock();
3900 return -EROFS;
3901 }
3902
3903 mutex_lock(&fs_info->scrub_lock);
3904 if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
3905 mutex_unlock(&fs_info->scrub_lock);
3906 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3907 return -EIO;
3908 }
3909
3910 btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
3911 if (dev->scrub_device ||
3912 (!is_dev_replace &&
3913 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3914 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3915 mutex_unlock(&fs_info->scrub_lock);
3916 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3917 return -EINPROGRESS;
3918 }
3919 btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3920
3921 ret = scrub_workers_get(fs_info, is_dev_replace);
3922 if (ret) {
3923 mutex_unlock(&fs_info->scrub_lock);
3924 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3925 return ret;
3926 }
3927
3928 sctx = scrub_setup_ctx(dev, is_dev_replace);
3929 if (IS_ERR(sctx)) {
3930 mutex_unlock(&fs_info->scrub_lock);
3931 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3932 scrub_workers_put(fs_info);
3933 return PTR_ERR(sctx);
3934 }
3935 sctx->readonly = readonly;
3936 dev->scrub_device = sctx;
3937 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3938
3939 /*
3940 * checking @scrub_pause_req here, we can avoid
3941 * race between committing transaction and scrubbing.
3942 */
3943 __scrub_blocked_if_needed(fs_info);
3944 atomic_inc(&fs_info->scrubs_running);
3945 mutex_unlock(&fs_info->scrub_lock);
3946
3947 if (!is_dev_replace) {
3948 /*
3949 * by holding device list mutex, we can
3950 * kick off writing super in log tree sync.
3951 */
3952 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3953 ret = scrub_supers(sctx, dev);
3954 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3955 }
3956
3957 if (!ret)
3958 ret = scrub_enumerate_chunks(sctx, dev, start, end,
3959 is_dev_replace);
3960
3961 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3962 atomic_dec(&fs_info->scrubs_running);
3963 wake_up(&fs_info->scrub_pause_wait);
3964
3965 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3966
3967 if (progress)
3968 memcpy(progress, &sctx->stat, sizeof(*progress));
3969
3970 mutex_lock(&fs_info->scrub_lock);
3971 dev->scrub_device = NULL;
3972 scrub_workers_put(fs_info);
3973 mutex_unlock(&fs_info->scrub_lock);
3974
3975 scrub_put_ctx(sctx);
3976
3977 return ret;
3978}
3979
3980void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3981{
3982 mutex_lock(&fs_info->scrub_lock);
3983 atomic_inc(&fs_info->scrub_pause_req);
3984 while (atomic_read(&fs_info->scrubs_paused) !=
3985 atomic_read(&fs_info->scrubs_running)) {
3986 mutex_unlock(&fs_info->scrub_lock);
3987 wait_event(fs_info->scrub_pause_wait,
3988 atomic_read(&fs_info->scrubs_paused) ==
3989 atomic_read(&fs_info->scrubs_running));
3990 mutex_lock(&fs_info->scrub_lock);
3991 }
3992 mutex_unlock(&fs_info->scrub_lock);
3993}
3994
3995void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3996{
3997 atomic_dec(&fs_info->scrub_pause_req);
3998 wake_up(&fs_info->scrub_pause_wait);
3999}
4000
4001int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
4002{
4003 mutex_lock(&fs_info->scrub_lock);
4004 if (!atomic_read(&fs_info->scrubs_running)) {
4005 mutex_unlock(&fs_info->scrub_lock);
4006 return -ENOTCONN;
4007 }
4008
4009 atomic_inc(&fs_info->scrub_cancel_req);
4010 while (atomic_read(&fs_info->scrubs_running)) {
4011 mutex_unlock(&fs_info->scrub_lock);
4012 wait_event(fs_info->scrub_pause_wait,
4013 atomic_read(&fs_info->scrubs_running) == 0);
4014 mutex_lock(&fs_info->scrub_lock);
4015 }
4016 atomic_dec(&fs_info->scrub_cancel_req);
4017 mutex_unlock(&fs_info->scrub_lock);
4018
4019 return 0;
4020}
4021
4022int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
4023 struct btrfs_device *dev)
4024{
4025 struct scrub_ctx *sctx;
4026
4027 mutex_lock(&fs_info->scrub_lock);
4028 sctx = dev->scrub_device;
4029 if (!sctx) {
4030 mutex_unlock(&fs_info->scrub_lock);
4031 return -ENOTCONN;
4032 }
4033 atomic_inc(&sctx->cancel_req);
4034 while (dev->scrub_device) {
4035 mutex_unlock(&fs_info->scrub_lock);
4036 wait_event(fs_info->scrub_pause_wait,
4037 dev->scrub_device == NULL);
4038 mutex_lock(&fs_info->scrub_lock);
4039 }
4040 mutex_unlock(&fs_info->scrub_lock);
4041
4042 return 0;
4043}
4044
4045int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4046 struct btrfs_scrub_progress *progress)
4047{
4048 struct btrfs_device *dev;
4049 struct scrub_ctx *sctx = NULL;
4050
4051 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4052 dev = btrfs_find_device(fs_info, devid, NULL, NULL);
4053 if (dev)
4054 sctx = dev->scrub_device;
4055 if (sctx)
4056 memcpy(progress, &sctx->stat, sizeof(*progress));
4057 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4058
4059 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4060}
4061
4062static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4063 u64 extent_logical, u64 extent_len,
4064 u64 *extent_physical,
4065 struct btrfs_device **extent_dev,
4066 int *extent_mirror_num)
4067{
4068 u64 mapped_length;
4069 struct btrfs_bio *bbio = NULL;
4070 int ret;
4071
4072 mapped_length = extent_len;
4073 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4074 &mapped_length, &bbio, 0);
4075 if (ret || !bbio || mapped_length < extent_len ||
4076 !bbio->stripes[0].dev->bdev) {
4077 btrfs_put_bbio(bbio);
4078 return;
4079 }
4080
4081 *extent_physical = bbio->stripes[0].physical;
4082 *extent_mirror_num = bbio->mirror_num;
4083 *extent_dev = bbio->stripes[0].dev;
4084 btrfs_put_bbio(bbio);
4085}
4086
4087static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
4088 struct scrub_wr_ctx *wr_ctx,
4089 struct btrfs_fs_info *fs_info,
4090 struct btrfs_device *dev,
4091 int is_dev_replace)
4092{
4093 WARN_ON(wr_ctx->wr_curr_bio != NULL);
4094
4095 mutex_init(&wr_ctx->wr_lock);
4096 wr_ctx->wr_curr_bio = NULL;
4097 if (!is_dev_replace)
4098 return 0;
4099
4100 WARN_ON(!dev->bdev);
4101 wr_ctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
4102 wr_ctx->tgtdev = dev;
4103 atomic_set(&wr_ctx->flush_all_writes, 0);
4104 return 0;
4105}
4106
4107static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
4108{
4109 mutex_lock(&wr_ctx->wr_lock);
4110 kfree(wr_ctx->wr_curr_bio);
4111 wr_ctx->wr_curr_bio = NULL;
4112 mutex_unlock(&wr_ctx->wr_lock);
4113}
4114
4115static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
4116 int mirror_num, u64 physical_for_dev_replace)
4117{
4118 struct scrub_copy_nocow_ctx *nocow_ctx;
4119 struct btrfs_fs_info *fs_info = sctx->fs_info;
4120
4121 nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
4122 if (!nocow_ctx) {
4123 spin_lock(&sctx->stat_lock);
4124 sctx->stat.malloc_errors++;
4125 spin_unlock(&sctx->stat_lock);
4126 return -ENOMEM;
4127 }
4128
4129 scrub_pending_trans_workers_inc(sctx);
4130
4131 nocow_ctx->sctx = sctx;
4132 nocow_ctx->logical = logical;
4133 nocow_ctx->len = len;
4134 nocow_ctx->mirror_num = mirror_num;
4135 nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
4136 btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
4137 copy_nocow_pages_worker, NULL, NULL);
4138 INIT_LIST_HEAD(&nocow_ctx->inodes);
4139 btrfs_queue_work(fs_info->scrub_nocow_workers,
4140 &nocow_ctx->work);
4141
4142 return 0;
4143}
4144
4145static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
4146{
4147 struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
4148 struct scrub_nocow_inode *nocow_inode;
4149
4150 nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
4151 if (!nocow_inode)
4152 return -ENOMEM;
4153 nocow_inode->inum = inum;
4154 nocow_inode->offset = offset;
4155 nocow_inode->root = root;
4156 list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
4157 return 0;
4158}
4159
4160#define COPY_COMPLETE 1
4161
4162static void copy_nocow_pages_worker(struct btrfs_work *work)
4163{
4164 struct scrub_copy_nocow_ctx *nocow_ctx =
4165 container_of(work, struct scrub_copy_nocow_ctx, work);
4166 struct scrub_ctx *sctx = nocow_ctx->sctx;
4167 struct btrfs_fs_info *fs_info = sctx->fs_info;
4168 struct btrfs_root *root = fs_info->extent_root;
4169 u64 logical = nocow_ctx->logical;
4170 u64 len = nocow_ctx->len;
4171 int mirror_num = nocow_ctx->mirror_num;
4172 u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4173 int ret;
4174 struct btrfs_trans_handle *trans = NULL;
4175 struct btrfs_path *path;
4176 int not_written = 0;
4177
4178 path = btrfs_alloc_path();
4179 if (!path) {
4180 spin_lock(&sctx->stat_lock);
4181 sctx->stat.malloc_errors++;
4182 spin_unlock(&sctx->stat_lock);
4183 not_written = 1;
4184 goto out;
4185 }
4186
4187 trans = btrfs_join_transaction(root);
4188 if (IS_ERR(trans)) {
4189 not_written = 1;
4190 goto out;
4191 }
4192
4193 ret = iterate_inodes_from_logical(logical, fs_info, path,
4194 record_inode_for_nocow, nocow_ctx);
4195 if (ret != 0 && ret != -ENOENT) {
4196 btrfs_warn(fs_info,
4197 "iterate_inodes_from_logical() failed: log %llu, phys %llu, len %llu, mir %u, ret %d",
4198 logical, physical_for_dev_replace, len, mirror_num,
4199 ret);
4200 not_written = 1;
4201 goto out;
4202 }
4203
4204 btrfs_end_transaction(trans);
4205 trans = NULL;
4206 while (!list_empty(&nocow_ctx->inodes)) {
4207 struct scrub_nocow_inode *entry;
4208 entry = list_first_entry(&nocow_ctx->inodes,
4209 struct scrub_nocow_inode,
4210 list);
4211 list_del_init(&entry->list);
4212 ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
4213 entry->root, nocow_ctx);
4214 kfree(entry);
4215 if (ret == COPY_COMPLETE) {
4216 ret = 0;
4217 break;
4218 } else if (ret) {
4219 break;
4220 }
4221 }
4222out:
4223 while (!list_empty(&nocow_ctx->inodes)) {
4224 struct scrub_nocow_inode *entry;
4225 entry = list_first_entry(&nocow_ctx->inodes,
4226 struct scrub_nocow_inode,
4227 list);
4228 list_del_init(&entry->list);
4229 kfree(entry);
4230 }
4231 if (trans && !IS_ERR(trans))
4232 btrfs_end_transaction(trans);
4233 if (not_written)
4234 btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
4235 num_uncorrectable_read_errors);
4236
4237 btrfs_free_path(path);
4238 kfree(nocow_ctx);
4239
4240 scrub_pending_trans_workers_dec(sctx);
4241}
4242
4243static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
4244 u64 logical)
4245{
4246 struct extent_state *cached_state = NULL;
4247 struct btrfs_ordered_extent *ordered;
4248 struct extent_io_tree *io_tree;
4249 struct extent_map *em;
4250 u64 lockstart = start, lockend = start + len - 1;
4251 int ret = 0;
4252
4253 io_tree = &BTRFS_I(inode)->io_tree;
4254
4255 lock_extent_bits(io_tree, lockstart, lockend, &cached_state);
4256 ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
4257 if (ordered) {
4258 btrfs_put_ordered_extent(ordered);
4259 ret = 1;
4260 goto out_unlock;
4261 }
4262
4263 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
4264 if (IS_ERR(em)) {
4265 ret = PTR_ERR(em);
4266 goto out_unlock;
4267 }
4268
4269 /*
4270 * This extent does not actually cover the logical extent anymore,
4271 * move on to the next inode.
4272 */
4273 if (em->block_start > logical ||
4274 em->block_start + em->block_len < logical + len) {
4275 free_extent_map(em);
4276 ret = 1;
4277 goto out_unlock;
4278 }
4279 free_extent_map(em);
4280
4281out_unlock:
4282 unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
4283 GFP_NOFS);
4284 return ret;
4285}
4286
4287static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
4288 struct scrub_copy_nocow_ctx *nocow_ctx)
4289{
4290 struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info;
4291 struct btrfs_key key;
4292 struct inode *inode;
4293 struct page *page;
4294 struct btrfs_root *local_root;
4295 struct extent_io_tree *io_tree;
4296 u64 physical_for_dev_replace;
4297 u64 nocow_ctx_logical;
4298 u64 len = nocow_ctx->len;
4299 unsigned long index;
4300 int srcu_index;
4301 int ret = 0;
4302 int err = 0;
4303
4304 key.objectid = root;
4305 key.type = BTRFS_ROOT_ITEM_KEY;
4306 key.offset = (u64)-1;
4307
4308 srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
4309
4310 local_root = btrfs_read_fs_root_no_name(fs_info, &key);
4311 if (IS_ERR(local_root)) {
4312 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4313 return PTR_ERR(local_root);
4314 }
4315
4316 key.type = BTRFS_INODE_ITEM_KEY;
4317 key.objectid = inum;
4318 key.offset = 0;
4319 inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
4320 srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
4321 if (IS_ERR(inode))
4322 return PTR_ERR(inode);
4323
4324 /* Avoid truncate/dio/punch hole.. */
4325 inode_lock(inode);
4326 inode_dio_wait(inode);
4327
4328 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
4329 io_tree = &BTRFS_I(inode)->io_tree;
4330 nocow_ctx_logical = nocow_ctx->logical;
4331
4332 ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
4333 if (ret) {
4334 ret = ret > 0 ? 0 : ret;
4335 goto out;
4336 }
4337
4338 while (len >= PAGE_SIZE) {
4339 index = offset >> PAGE_SHIFT;
4340again:
4341 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4342 if (!page) {
4343 btrfs_err(fs_info, "find_or_create_page() failed");
4344 ret = -ENOMEM;
4345 goto out;
4346 }
4347
4348 if (PageUptodate(page)) {
4349 if (PageDirty(page))
4350 goto next_page;
4351 } else {
4352 ClearPageError(page);
4353 err = extent_read_full_page(io_tree, page,
4354 btrfs_get_extent,
4355 nocow_ctx->mirror_num);
4356 if (err) {
4357 ret = err;
4358 goto next_page;
4359 }
4360
4361 lock_page(page);
4362 /*
4363 * If the page has been remove from the page cache,
4364 * the data on it is meaningless, because it may be
4365 * old one, the new data may be written into the new
4366 * page in the page cache.
4367 */
4368 if (page->mapping != inode->i_mapping) {
4369 unlock_page(page);
4370 put_page(page);
4371 goto again;
4372 }
4373 if (!PageUptodate(page)) {
4374 ret = -EIO;
4375 goto next_page;
4376 }
4377 }
4378
4379 ret = check_extent_to_block(inode, offset, len,
4380 nocow_ctx_logical);
4381 if (ret) {
4382 ret = ret > 0 ? 0 : ret;
4383 goto next_page;
4384 }
4385
4386 err = write_page_nocow(nocow_ctx->sctx,
4387 physical_for_dev_replace, page);
4388 if (err)
4389 ret = err;
4390next_page:
4391 unlock_page(page);
4392 put_page(page);
4393
4394 if (ret)
4395 break;
4396
4397 offset += PAGE_SIZE;
4398 physical_for_dev_replace += PAGE_SIZE;
4399 nocow_ctx_logical += PAGE_SIZE;
4400 len -= PAGE_SIZE;
4401 }
4402 ret = COPY_COMPLETE;
4403out:
4404 inode_unlock(inode);
4405 iput(inode);
4406 return ret;
4407}
4408
4409static int write_page_nocow(struct scrub_ctx *sctx,
4410 u64 physical_for_dev_replace, struct page *page)
4411{
4412 struct bio *bio;
4413 struct btrfs_device *dev;
4414 int ret;
4415
4416 dev = sctx->wr_ctx.tgtdev;
4417 if (!dev)
4418 return -EIO;
4419 if (!dev->bdev) {
4420 btrfs_warn_rl(dev->fs_info,
4421 "scrub write_page_nocow(bdev == NULL) is unexpected");
4422 return -EIO;
4423 }
4424 bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
4425 if (!bio) {
4426 spin_lock(&sctx->stat_lock);
4427 sctx->stat.malloc_errors++;
4428 spin_unlock(&sctx->stat_lock);
4429 return -ENOMEM;
4430 }
4431 bio->bi_iter.bi_size = 0;
4432 bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
4433 bio->bi_bdev = dev->bdev;
4434 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
4435 ret = bio_add_page(bio, page, PAGE_SIZE, 0);
4436 if (ret != PAGE_SIZE) {
4437leave_with_eio:
4438 bio_put(bio);
4439 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
4440 return -EIO;
4441 }
4442
4443 if (btrfsic_submit_bio_wait(bio))
4444 goto leave_with_eio;
4445
4446 bio_put(bio);
4447 return 0;
4448}