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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 <crypto/hash.h>
10#include "ctree.h"
11#include "volumes.h"
12#include "disk-io.h"
13#include "ordered-data.h"
14#include "transaction.h"
15#include "backref.h"
16#include "extent_io.h"
17#include "dev-replace.h"
18#include "check-integrity.h"
19#include "rcu-string.h"
20#include "raid56.h"
21#include "block-group.h"
22
23/*
24 * This is only the first step towards a full-features scrub. It reads all
25 * extent and super block and verifies the checksums. In case a bad checksum
26 * is found or the extent cannot be read, good data will be written back if
27 * any can be found.
28 *
29 * Future enhancements:
30 * - In case an unrepairable extent is encountered, track which files are
31 * affected and report them
32 * - track and record media errors, throw out bad devices
33 * - add a mode to also read unallocated space
34 */
35
36struct scrub_block;
37struct scrub_ctx;
38
39/*
40 * the following three values only influence the performance.
41 * The last one configures the number of parallel and outstanding I/O
42 * operations. The first two values configure an upper limit for the number
43 * of (dynamically allocated) pages that are added to a bio.
44 */
45#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
46#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
47#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
48
49/*
50 * the following value times PAGE_SIZE needs to be large enough to match the
51 * largest node/leaf/sector size that shall be supported.
52 * Values larger than BTRFS_STRIPE_LEN are not supported.
53 */
54#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
55
56struct scrub_recover {
57 refcount_t refs;
58 struct btrfs_bio *bbio;
59 u64 map_length;
60};
61
62struct scrub_page {
63 struct scrub_block *sblock;
64 struct page *page;
65 struct btrfs_device *dev;
66 struct list_head list;
67 u64 flags; /* extent flags */
68 u64 generation;
69 u64 logical;
70 u64 physical;
71 u64 physical_for_dev_replace;
72 atomic_t refs;
73 struct {
74 unsigned int mirror_num:8;
75 unsigned int have_csum:1;
76 unsigned int io_error:1;
77 };
78 u8 csum[BTRFS_CSUM_SIZE];
79
80 struct scrub_recover *recover;
81};
82
83struct scrub_bio {
84 int index;
85 struct scrub_ctx *sctx;
86 struct btrfs_device *dev;
87 struct bio *bio;
88 blk_status_t status;
89 u64 logical;
90 u64 physical;
91#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
92 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
93#else
94 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
95#endif
96 int page_count;
97 int next_free;
98 struct btrfs_work work;
99};
100
101struct scrub_block {
102 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
103 int page_count;
104 atomic_t outstanding_pages;
105 refcount_t refs; /* free mem on transition to zero */
106 struct scrub_ctx *sctx;
107 struct scrub_parity *sparity;
108 struct {
109 unsigned int header_error:1;
110 unsigned int checksum_error:1;
111 unsigned int no_io_error_seen:1;
112 unsigned int generation_error:1; /* also sets header_error */
113
114 /* The following is for the data used to check parity */
115 /* It is for the data with checksum */
116 unsigned int data_corrected:1;
117 };
118 struct btrfs_work work;
119};
120
121/* Used for the chunks with parity stripe such RAID5/6 */
122struct scrub_parity {
123 struct scrub_ctx *sctx;
124
125 struct btrfs_device *scrub_dev;
126
127 u64 logic_start;
128
129 u64 logic_end;
130
131 int nsectors;
132
133 u64 stripe_len;
134
135 refcount_t refs;
136
137 struct list_head spages;
138
139 /* Work of parity check and repair */
140 struct btrfs_work work;
141
142 /* Mark the parity blocks which have data */
143 unsigned long *dbitmap;
144
145 /*
146 * Mark the parity blocks which have data, but errors happen when
147 * read data or check data
148 */
149 unsigned long *ebitmap;
150
151 unsigned long bitmap[0];
152};
153
154struct scrub_ctx {
155 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
156 struct btrfs_fs_info *fs_info;
157 int first_free;
158 int curr;
159 atomic_t bios_in_flight;
160 atomic_t workers_pending;
161 spinlock_t list_lock;
162 wait_queue_head_t list_wait;
163 u16 csum_size;
164 struct list_head csum_list;
165 atomic_t cancel_req;
166 int readonly;
167 int pages_per_rd_bio;
168
169 int is_dev_replace;
170
171 struct scrub_bio *wr_curr_bio;
172 struct mutex wr_lock;
173 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
174 struct btrfs_device *wr_tgtdev;
175 bool flush_all_writes;
176
177 /*
178 * statistics
179 */
180 struct btrfs_scrub_progress stat;
181 spinlock_t stat_lock;
182
183 /*
184 * Use a ref counter to avoid use-after-free issues. Scrub workers
185 * decrement bios_in_flight and workers_pending and then do a wakeup
186 * on the list_wait wait queue. We must ensure the main scrub task
187 * doesn't free the scrub context before or while the workers are
188 * doing the wakeup() call.
189 */
190 refcount_t refs;
191};
192
193struct scrub_warning {
194 struct btrfs_path *path;
195 u64 extent_item_size;
196 const char *errstr;
197 u64 physical;
198 u64 logical;
199 struct btrfs_device *dev;
200};
201
202struct full_stripe_lock {
203 struct rb_node node;
204 u64 logical;
205 u64 refs;
206 struct mutex mutex;
207};
208
209static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
210static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
211static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
212static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
213 struct scrub_block *sblocks_for_recheck);
214static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
215 struct scrub_block *sblock,
216 int retry_failed_mirror);
217static void scrub_recheck_block_checksum(struct scrub_block *sblock);
218static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
219 struct scrub_block *sblock_good);
220static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
221 struct scrub_block *sblock_good,
222 int page_num, int force_write);
223static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
224static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
225 int page_num);
226static int scrub_checksum_data(struct scrub_block *sblock);
227static int scrub_checksum_tree_block(struct scrub_block *sblock);
228static int scrub_checksum_super(struct scrub_block *sblock);
229static void scrub_block_get(struct scrub_block *sblock);
230static void scrub_block_put(struct scrub_block *sblock);
231static void scrub_page_get(struct scrub_page *spage);
232static void scrub_page_put(struct scrub_page *spage);
233static void scrub_parity_get(struct scrub_parity *sparity);
234static void scrub_parity_put(struct scrub_parity *sparity);
235static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
236 struct scrub_page *spage);
237static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
238 u64 physical, struct btrfs_device *dev, u64 flags,
239 u64 gen, int mirror_num, u8 *csum, int force,
240 u64 physical_for_dev_replace);
241static void scrub_bio_end_io(struct bio *bio);
242static void scrub_bio_end_io_worker(struct btrfs_work *work);
243static void scrub_block_complete(struct scrub_block *sblock);
244static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
245 u64 extent_logical, u64 extent_len,
246 u64 *extent_physical,
247 struct btrfs_device **extent_dev,
248 int *extent_mirror_num);
249static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
250 struct scrub_page *spage);
251static void scrub_wr_submit(struct scrub_ctx *sctx);
252static void scrub_wr_bio_end_io(struct bio *bio);
253static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
254static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
255static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
256static void scrub_put_ctx(struct scrub_ctx *sctx);
257
258static inline int scrub_is_page_on_raid56(struct scrub_page *page)
259{
260 return page->recover &&
261 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
262}
263
264static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
265{
266 refcount_inc(&sctx->refs);
267 atomic_inc(&sctx->bios_in_flight);
268}
269
270static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
271{
272 atomic_dec(&sctx->bios_in_flight);
273 wake_up(&sctx->list_wait);
274 scrub_put_ctx(sctx);
275}
276
277static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
278{
279 while (atomic_read(&fs_info->scrub_pause_req)) {
280 mutex_unlock(&fs_info->scrub_lock);
281 wait_event(fs_info->scrub_pause_wait,
282 atomic_read(&fs_info->scrub_pause_req) == 0);
283 mutex_lock(&fs_info->scrub_lock);
284 }
285}
286
287static void scrub_pause_on(struct btrfs_fs_info *fs_info)
288{
289 atomic_inc(&fs_info->scrubs_paused);
290 wake_up(&fs_info->scrub_pause_wait);
291}
292
293static void scrub_pause_off(struct btrfs_fs_info *fs_info)
294{
295 mutex_lock(&fs_info->scrub_lock);
296 __scrub_blocked_if_needed(fs_info);
297 atomic_dec(&fs_info->scrubs_paused);
298 mutex_unlock(&fs_info->scrub_lock);
299
300 wake_up(&fs_info->scrub_pause_wait);
301}
302
303static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
304{
305 scrub_pause_on(fs_info);
306 scrub_pause_off(fs_info);
307}
308
309/*
310 * Insert new full stripe lock into full stripe locks tree
311 *
312 * Return pointer to existing or newly inserted full_stripe_lock structure if
313 * everything works well.
314 * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
315 *
316 * NOTE: caller must hold full_stripe_locks_root->lock before calling this
317 * function
318 */
319static struct full_stripe_lock *insert_full_stripe_lock(
320 struct btrfs_full_stripe_locks_tree *locks_root,
321 u64 fstripe_logical)
322{
323 struct rb_node **p;
324 struct rb_node *parent = NULL;
325 struct full_stripe_lock *entry;
326 struct full_stripe_lock *ret;
327
328 lockdep_assert_held(&locks_root->lock);
329
330 p = &locks_root->root.rb_node;
331 while (*p) {
332 parent = *p;
333 entry = rb_entry(parent, struct full_stripe_lock, node);
334 if (fstripe_logical < entry->logical) {
335 p = &(*p)->rb_left;
336 } else if (fstripe_logical > entry->logical) {
337 p = &(*p)->rb_right;
338 } else {
339 entry->refs++;
340 return entry;
341 }
342 }
343
344 /*
345 * Insert new lock.
346 */
347 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
348 if (!ret)
349 return ERR_PTR(-ENOMEM);
350 ret->logical = fstripe_logical;
351 ret->refs = 1;
352 mutex_init(&ret->mutex);
353
354 rb_link_node(&ret->node, parent, p);
355 rb_insert_color(&ret->node, &locks_root->root);
356 return ret;
357}
358
359/*
360 * Search for a full stripe lock of a block group
361 *
362 * Return pointer to existing full stripe lock if found
363 * Return NULL if not found
364 */
365static struct full_stripe_lock *search_full_stripe_lock(
366 struct btrfs_full_stripe_locks_tree *locks_root,
367 u64 fstripe_logical)
368{
369 struct rb_node *node;
370 struct full_stripe_lock *entry;
371
372 lockdep_assert_held(&locks_root->lock);
373
374 node = locks_root->root.rb_node;
375 while (node) {
376 entry = rb_entry(node, struct full_stripe_lock, node);
377 if (fstripe_logical < entry->logical)
378 node = node->rb_left;
379 else if (fstripe_logical > entry->logical)
380 node = node->rb_right;
381 else
382 return entry;
383 }
384 return NULL;
385}
386
387/*
388 * Helper to get full stripe logical from a normal bytenr.
389 *
390 * Caller must ensure @cache is a RAID56 block group.
391 */
392static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
393 u64 bytenr)
394{
395 u64 ret;
396
397 /*
398 * Due to chunk item size limit, full stripe length should not be
399 * larger than U32_MAX. Just a sanity check here.
400 */
401 WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
402
403 /*
404 * round_down() can only handle power of 2, while RAID56 full
405 * stripe length can be 64KiB * n, so we need to manually round down.
406 */
407 ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
408 cache->full_stripe_len + cache->key.objectid;
409 return ret;
410}
411
412/*
413 * Lock a full stripe to avoid concurrency of recovery and read
414 *
415 * It's only used for profiles with parities (RAID5/6), for other profiles it
416 * does nothing.
417 *
418 * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
419 * So caller must call unlock_full_stripe() at the same context.
420 *
421 * Return <0 if encounters error.
422 */
423static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
424 bool *locked_ret)
425{
426 struct btrfs_block_group_cache *bg_cache;
427 struct btrfs_full_stripe_locks_tree *locks_root;
428 struct full_stripe_lock *existing;
429 u64 fstripe_start;
430 int ret = 0;
431
432 *locked_ret = false;
433 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
434 if (!bg_cache) {
435 ASSERT(0);
436 return -ENOENT;
437 }
438
439 /* Profiles not based on parity don't need full stripe lock */
440 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
441 goto out;
442 locks_root = &bg_cache->full_stripe_locks_root;
443
444 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
445
446 /* Now insert the full stripe lock */
447 mutex_lock(&locks_root->lock);
448 existing = insert_full_stripe_lock(locks_root, fstripe_start);
449 mutex_unlock(&locks_root->lock);
450 if (IS_ERR(existing)) {
451 ret = PTR_ERR(existing);
452 goto out;
453 }
454 mutex_lock(&existing->mutex);
455 *locked_ret = true;
456out:
457 btrfs_put_block_group(bg_cache);
458 return ret;
459}
460
461/*
462 * Unlock a full stripe.
463 *
464 * NOTE: Caller must ensure it's the same context calling corresponding
465 * lock_full_stripe().
466 *
467 * Return 0 if we unlock full stripe without problem.
468 * Return <0 for error
469 */
470static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
471 bool locked)
472{
473 struct btrfs_block_group_cache *bg_cache;
474 struct btrfs_full_stripe_locks_tree *locks_root;
475 struct full_stripe_lock *fstripe_lock;
476 u64 fstripe_start;
477 bool freeit = false;
478 int ret = 0;
479
480 /* If we didn't acquire full stripe lock, no need to continue */
481 if (!locked)
482 return 0;
483
484 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
485 if (!bg_cache) {
486 ASSERT(0);
487 return -ENOENT;
488 }
489 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
490 goto out;
491
492 locks_root = &bg_cache->full_stripe_locks_root;
493 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
494
495 mutex_lock(&locks_root->lock);
496 fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
497 /* Unpaired unlock_full_stripe() detected */
498 if (!fstripe_lock) {
499 WARN_ON(1);
500 ret = -ENOENT;
501 mutex_unlock(&locks_root->lock);
502 goto out;
503 }
504
505 if (fstripe_lock->refs == 0) {
506 WARN_ON(1);
507 btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
508 fstripe_lock->logical);
509 } else {
510 fstripe_lock->refs--;
511 }
512
513 if (fstripe_lock->refs == 0) {
514 rb_erase(&fstripe_lock->node, &locks_root->root);
515 freeit = true;
516 }
517 mutex_unlock(&locks_root->lock);
518
519 mutex_unlock(&fstripe_lock->mutex);
520 if (freeit)
521 kfree(fstripe_lock);
522out:
523 btrfs_put_block_group(bg_cache);
524 return ret;
525}
526
527static void scrub_free_csums(struct scrub_ctx *sctx)
528{
529 while (!list_empty(&sctx->csum_list)) {
530 struct btrfs_ordered_sum *sum;
531 sum = list_first_entry(&sctx->csum_list,
532 struct btrfs_ordered_sum, list);
533 list_del(&sum->list);
534 kfree(sum);
535 }
536}
537
538static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
539{
540 int i;
541
542 if (!sctx)
543 return;
544
545 /* this can happen when scrub is cancelled */
546 if (sctx->curr != -1) {
547 struct scrub_bio *sbio = sctx->bios[sctx->curr];
548
549 for (i = 0; i < sbio->page_count; i++) {
550 WARN_ON(!sbio->pagev[i]->page);
551 scrub_block_put(sbio->pagev[i]->sblock);
552 }
553 bio_put(sbio->bio);
554 }
555
556 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
557 struct scrub_bio *sbio = sctx->bios[i];
558
559 if (!sbio)
560 break;
561 kfree(sbio);
562 }
563
564 kfree(sctx->wr_curr_bio);
565 scrub_free_csums(sctx);
566 kfree(sctx);
567}
568
569static void scrub_put_ctx(struct scrub_ctx *sctx)
570{
571 if (refcount_dec_and_test(&sctx->refs))
572 scrub_free_ctx(sctx);
573}
574
575static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
576 struct btrfs_fs_info *fs_info, int is_dev_replace)
577{
578 struct scrub_ctx *sctx;
579 int i;
580
581 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
582 if (!sctx)
583 goto nomem;
584 refcount_set(&sctx->refs, 1);
585 sctx->is_dev_replace = is_dev_replace;
586 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
587 sctx->curr = -1;
588 sctx->fs_info = fs_info;
589 INIT_LIST_HEAD(&sctx->csum_list);
590 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
591 struct scrub_bio *sbio;
592
593 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
594 if (!sbio)
595 goto nomem;
596 sctx->bios[i] = sbio;
597
598 sbio->index = i;
599 sbio->sctx = sctx;
600 sbio->page_count = 0;
601 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
602 scrub_bio_end_io_worker, NULL, NULL);
603
604 if (i != SCRUB_BIOS_PER_SCTX - 1)
605 sctx->bios[i]->next_free = i + 1;
606 else
607 sctx->bios[i]->next_free = -1;
608 }
609 sctx->first_free = 0;
610 atomic_set(&sctx->bios_in_flight, 0);
611 atomic_set(&sctx->workers_pending, 0);
612 atomic_set(&sctx->cancel_req, 0);
613 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
614
615 spin_lock_init(&sctx->list_lock);
616 spin_lock_init(&sctx->stat_lock);
617 init_waitqueue_head(&sctx->list_wait);
618
619 WARN_ON(sctx->wr_curr_bio != NULL);
620 mutex_init(&sctx->wr_lock);
621 sctx->wr_curr_bio = NULL;
622 if (is_dev_replace) {
623 WARN_ON(!fs_info->dev_replace.tgtdev);
624 sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
625 sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
626 sctx->flush_all_writes = false;
627 }
628
629 return sctx;
630
631nomem:
632 scrub_free_ctx(sctx);
633 return ERR_PTR(-ENOMEM);
634}
635
636static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
637 void *warn_ctx)
638{
639 u64 isize;
640 u32 nlink;
641 int ret;
642 int i;
643 unsigned nofs_flag;
644 struct extent_buffer *eb;
645 struct btrfs_inode_item *inode_item;
646 struct scrub_warning *swarn = warn_ctx;
647 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
648 struct inode_fs_paths *ipath = NULL;
649 struct btrfs_root *local_root;
650 struct btrfs_key root_key;
651 struct btrfs_key key;
652
653 root_key.objectid = root;
654 root_key.type = BTRFS_ROOT_ITEM_KEY;
655 root_key.offset = (u64)-1;
656 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
657 if (IS_ERR(local_root)) {
658 ret = PTR_ERR(local_root);
659 goto err;
660 }
661
662 /*
663 * this makes the path point to (inum INODE_ITEM ioff)
664 */
665 key.objectid = inum;
666 key.type = BTRFS_INODE_ITEM_KEY;
667 key.offset = 0;
668
669 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
670 if (ret) {
671 btrfs_release_path(swarn->path);
672 goto err;
673 }
674
675 eb = swarn->path->nodes[0];
676 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
677 struct btrfs_inode_item);
678 isize = btrfs_inode_size(eb, inode_item);
679 nlink = btrfs_inode_nlink(eb, inode_item);
680 btrfs_release_path(swarn->path);
681
682 /*
683 * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
684 * uses GFP_NOFS in this context, so we keep it consistent but it does
685 * not seem to be strictly necessary.
686 */
687 nofs_flag = memalloc_nofs_save();
688 ipath = init_ipath(4096, local_root, swarn->path);
689 memalloc_nofs_restore(nofs_flag);
690 if (IS_ERR(ipath)) {
691 ret = PTR_ERR(ipath);
692 ipath = NULL;
693 goto err;
694 }
695 ret = paths_from_inode(inum, ipath);
696
697 if (ret < 0)
698 goto err;
699
700 /*
701 * we deliberately ignore the bit ipath might have been too small to
702 * hold all of the paths here
703 */
704 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
705 btrfs_warn_in_rcu(fs_info,
706"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
707 swarn->errstr, swarn->logical,
708 rcu_str_deref(swarn->dev->name),
709 swarn->physical,
710 root, inum, offset,
711 min(isize - offset, (u64)PAGE_SIZE), nlink,
712 (char *)(unsigned long)ipath->fspath->val[i]);
713
714 free_ipath(ipath);
715 return 0;
716
717err:
718 btrfs_warn_in_rcu(fs_info,
719 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
720 swarn->errstr, swarn->logical,
721 rcu_str_deref(swarn->dev->name),
722 swarn->physical,
723 root, inum, offset, ret);
724
725 free_ipath(ipath);
726 return 0;
727}
728
729static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
730{
731 struct btrfs_device *dev;
732 struct btrfs_fs_info *fs_info;
733 struct btrfs_path *path;
734 struct btrfs_key found_key;
735 struct extent_buffer *eb;
736 struct btrfs_extent_item *ei;
737 struct scrub_warning swarn;
738 unsigned long ptr = 0;
739 u64 extent_item_pos;
740 u64 flags = 0;
741 u64 ref_root;
742 u32 item_size;
743 u8 ref_level = 0;
744 int ret;
745
746 WARN_ON(sblock->page_count < 1);
747 dev = sblock->pagev[0]->dev;
748 fs_info = sblock->sctx->fs_info;
749
750 path = btrfs_alloc_path();
751 if (!path)
752 return;
753
754 swarn.physical = sblock->pagev[0]->physical;
755 swarn.logical = sblock->pagev[0]->logical;
756 swarn.errstr = errstr;
757 swarn.dev = NULL;
758
759 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
760 &flags);
761 if (ret < 0)
762 goto out;
763
764 extent_item_pos = swarn.logical - found_key.objectid;
765 swarn.extent_item_size = found_key.offset;
766
767 eb = path->nodes[0];
768 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
769 item_size = btrfs_item_size_nr(eb, path->slots[0]);
770
771 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
772 do {
773 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
774 item_size, &ref_root,
775 &ref_level);
776 btrfs_warn_in_rcu(fs_info,
777"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
778 errstr, swarn.logical,
779 rcu_str_deref(dev->name),
780 swarn.physical,
781 ref_level ? "node" : "leaf",
782 ret < 0 ? -1 : ref_level,
783 ret < 0 ? -1 : ref_root);
784 } while (ret != 1);
785 btrfs_release_path(path);
786 } else {
787 btrfs_release_path(path);
788 swarn.path = path;
789 swarn.dev = dev;
790 iterate_extent_inodes(fs_info, found_key.objectid,
791 extent_item_pos, 1,
792 scrub_print_warning_inode, &swarn, false);
793 }
794
795out:
796 btrfs_free_path(path);
797}
798
799static inline void scrub_get_recover(struct scrub_recover *recover)
800{
801 refcount_inc(&recover->refs);
802}
803
804static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
805 struct scrub_recover *recover)
806{
807 if (refcount_dec_and_test(&recover->refs)) {
808 btrfs_bio_counter_dec(fs_info);
809 btrfs_put_bbio(recover->bbio);
810 kfree(recover);
811 }
812}
813
814/*
815 * scrub_handle_errored_block gets called when either verification of the
816 * pages failed or the bio failed to read, e.g. with EIO. In the latter
817 * case, this function handles all pages in the bio, even though only one
818 * may be bad.
819 * The goal of this function is to repair the errored block by using the
820 * contents of one of the mirrors.
821 */
822static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
823{
824 struct scrub_ctx *sctx = sblock_to_check->sctx;
825 struct btrfs_device *dev;
826 struct btrfs_fs_info *fs_info;
827 u64 logical;
828 unsigned int failed_mirror_index;
829 unsigned int is_metadata;
830 unsigned int have_csum;
831 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
832 struct scrub_block *sblock_bad;
833 int ret;
834 int mirror_index;
835 int page_num;
836 int success;
837 bool full_stripe_locked;
838 unsigned int nofs_flag;
839 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
840 DEFAULT_RATELIMIT_BURST);
841
842 BUG_ON(sblock_to_check->page_count < 1);
843 fs_info = sctx->fs_info;
844 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
845 /*
846 * if we find an error in a super block, we just report it.
847 * They will get written with the next transaction commit
848 * anyway
849 */
850 spin_lock(&sctx->stat_lock);
851 ++sctx->stat.super_errors;
852 spin_unlock(&sctx->stat_lock);
853 return 0;
854 }
855 logical = sblock_to_check->pagev[0]->logical;
856 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
857 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
858 is_metadata = !(sblock_to_check->pagev[0]->flags &
859 BTRFS_EXTENT_FLAG_DATA);
860 have_csum = sblock_to_check->pagev[0]->have_csum;
861 dev = sblock_to_check->pagev[0]->dev;
862
863 /*
864 * We must use GFP_NOFS because the scrub task might be waiting for a
865 * worker task executing this function and in turn a transaction commit
866 * might be waiting the scrub task to pause (which needs to wait for all
867 * the worker tasks to complete before pausing).
868 * We do allocations in the workers through insert_full_stripe_lock()
869 * and scrub_add_page_to_wr_bio(), which happens down the call chain of
870 * this function.
871 */
872 nofs_flag = memalloc_nofs_save();
873 /*
874 * For RAID5/6, race can happen for a different device scrub thread.
875 * For data corruption, Parity and Data threads will both try
876 * to recovery the data.
877 * Race can lead to doubly added csum error, or even unrecoverable
878 * error.
879 */
880 ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
881 if (ret < 0) {
882 memalloc_nofs_restore(nofs_flag);
883 spin_lock(&sctx->stat_lock);
884 if (ret == -ENOMEM)
885 sctx->stat.malloc_errors++;
886 sctx->stat.read_errors++;
887 sctx->stat.uncorrectable_errors++;
888 spin_unlock(&sctx->stat_lock);
889 return ret;
890 }
891
892 /*
893 * read all mirrors one after the other. This includes to
894 * re-read the extent or metadata block that failed (that was
895 * the cause that this fixup code is called) another time,
896 * page by page this time in order to know which pages
897 * caused I/O errors and which ones are good (for all mirrors).
898 * It is the goal to handle the situation when more than one
899 * mirror contains I/O errors, but the errors do not
900 * overlap, i.e. the data can be repaired by selecting the
901 * pages from those mirrors without I/O error on the
902 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
903 * would be that mirror #1 has an I/O error on the first page,
904 * the second page is good, and mirror #2 has an I/O error on
905 * the second page, but the first page is good.
906 * Then the first page of the first mirror can be repaired by
907 * taking the first page of the second mirror, and the
908 * second page of the second mirror can be repaired by
909 * copying the contents of the 2nd page of the 1st mirror.
910 * One more note: if the pages of one mirror contain I/O
911 * errors, the checksum cannot be verified. In order to get
912 * the best data for repairing, the first attempt is to find
913 * a mirror without I/O errors and with a validated checksum.
914 * Only if this is not possible, the pages are picked from
915 * mirrors with I/O errors without considering the checksum.
916 * If the latter is the case, at the end, the checksum of the
917 * repaired area is verified in order to correctly maintain
918 * the statistics.
919 */
920
921 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
922 sizeof(*sblocks_for_recheck), GFP_KERNEL);
923 if (!sblocks_for_recheck) {
924 spin_lock(&sctx->stat_lock);
925 sctx->stat.malloc_errors++;
926 sctx->stat.read_errors++;
927 sctx->stat.uncorrectable_errors++;
928 spin_unlock(&sctx->stat_lock);
929 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
930 goto out;
931 }
932
933 /* setup the context, map the logical blocks and alloc the pages */
934 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
935 if (ret) {
936 spin_lock(&sctx->stat_lock);
937 sctx->stat.read_errors++;
938 sctx->stat.uncorrectable_errors++;
939 spin_unlock(&sctx->stat_lock);
940 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
941 goto out;
942 }
943 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
944 sblock_bad = sblocks_for_recheck + failed_mirror_index;
945
946 /* build and submit the bios for the failed mirror, check checksums */
947 scrub_recheck_block(fs_info, sblock_bad, 1);
948
949 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
950 sblock_bad->no_io_error_seen) {
951 /*
952 * the error disappeared after reading page by page, or
953 * the area was part of a huge bio and other parts of the
954 * bio caused I/O errors, or the block layer merged several
955 * read requests into one and the error is caused by a
956 * different bio (usually one of the two latter cases is
957 * the cause)
958 */
959 spin_lock(&sctx->stat_lock);
960 sctx->stat.unverified_errors++;
961 sblock_to_check->data_corrected = 1;
962 spin_unlock(&sctx->stat_lock);
963
964 if (sctx->is_dev_replace)
965 scrub_write_block_to_dev_replace(sblock_bad);
966 goto out;
967 }
968
969 if (!sblock_bad->no_io_error_seen) {
970 spin_lock(&sctx->stat_lock);
971 sctx->stat.read_errors++;
972 spin_unlock(&sctx->stat_lock);
973 if (__ratelimit(&_rs))
974 scrub_print_warning("i/o error", sblock_to_check);
975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
976 } else if (sblock_bad->checksum_error) {
977 spin_lock(&sctx->stat_lock);
978 sctx->stat.csum_errors++;
979 spin_unlock(&sctx->stat_lock);
980 if (__ratelimit(&_rs))
981 scrub_print_warning("checksum error", sblock_to_check);
982 btrfs_dev_stat_inc_and_print(dev,
983 BTRFS_DEV_STAT_CORRUPTION_ERRS);
984 } else if (sblock_bad->header_error) {
985 spin_lock(&sctx->stat_lock);
986 sctx->stat.verify_errors++;
987 spin_unlock(&sctx->stat_lock);
988 if (__ratelimit(&_rs))
989 scrub_print_warning("checksum/header error",
990 sblock_to_check);
991 if (sblock_bad->generation_error)
992 btrfs_dev_stat_inc_and_print(dev,
993 BTRFS_DEV_STAT_GENERATION_ERRS);
994 else
995 btrfs_dev_stat_inc_and_print(dev,
996 BTRFS_DEV_STAT_CORRUPTION_ERRS);
997 }
998
999 if (sctx->readonly) {
1000 ASSERT(!sctx->is_dev_replace);
1001 goto out;
1002 }
1003
1004 /*
1005 * now build and submit the bios for the other mirrors, check
1006 * checksums.
1007 * First try to pick the mirror which is completely without I/O
1008 * errors and also does not have a checksum error.
1009 * If one is found, and if a checksum is present, the full block
1010 * that is known to contain an error is rewritten. Afterwards
1011 * the block is known to be corrected.
1012 * If a mirror is found which is completely correct, and no
1013 * checksum is present, only those pages are rewritten that had
1014 * an I/O error in the block to be repaired, since it cannot be
1015 * determined, which copy of the other pages is better (and it
1016 * could happen otherwise that a correct page would be
1017 * overwritten by a bad one).
1018 */
1019 for (mirror_index = 0; ;mirror_index++) {
1020 struct scrub_block *sblock_other;
1021
1022 if (mirror_index == failed_mirror_index)
1023 continue;
1024
1025 /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
1026 if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1027 if (mirror_index >= BTRFS_MAX_MIRRORS)
1028 break;
1029 if (!sblocks_for_recheck[mirror_index].page_count)
1030 break;
1031
1032 sblock_other = sblocks_for_recheck + mirror_index;
1033 } else {
1034 struct scrub_recover *r = sblock_bad->pagev[0]->recover;
1035 int max_allowed = r->bbio->num_stripes -
1036 r->bbio->num_tgtdevs;
1037
1038 if (mirror_index >= max_allowed)
1039 break;
1040 if (!sblocks_for_recheck[1].page_count)
1041 break;
1042
1043 ASSERT(failed_mirror_index == 0);
1044 sblock_other = sblocks_for_recheck + 1;
1045 sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
1046 }
1047
1048 /* build and submit the bios, check checksums */
1049 scrub_recheck_block(fs_info, sblock_other, 0);
1050
1051 if (!sblock_other->header_error &&
1052 !sblock_other->checksum_error &&
1053 sblock_other->no_io_error_seen) {
1054 if (sctx->is_dev_replace) {
1055 scrub_write_block_to_dev_replace(sblock_other);
1056 goto corrected_error;
1057 } else {
1058 ret = scrub_repair_block_from_good_copy(
1059 sblock_bad, sblock_other);
1060 if (!ret)
1061 goto corrected_error;
1062 }
1063 }
1064 }
1065
1066 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1067 goto did_not_correct_error;
1068
1069 /*
1070 * In case of I/O errors in the area that is supposed to be
1071 * repaired, continue by picking good copies of those pages.
1072 * Select the good pages from mirrors to rewrite bad pages from
1073 * the area to fix. Afterwards verify the checksum of the block
1074 * that is supposed to be repaired. This verification step is
1075 * only done for the purpose of statistic counting and for the
1076 * final scrub report, whether errors remain.
1077 * A perfect algorithm could make use of the checksum and try
1078 * all possible combinations of pages from the different mirrors
1079 * until the checksum verification succeeds. For example, when
1080 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1081 * of mirror #2 is readable but the final checksum test fails,
1082 * then the 2nd page of mirror #3 could be tried, whether now
1083 * the final checksum succeeds. But this would be a rare
1084 * exception and is therefore not implemented. At least it is
1085 * avoided that the good copy is overwritten.
1086 * A more useful improvement would be to pick the sectors
1087 * without I/O error based on sector sizes (512 bytes on legacy
1088 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1089 * mirror could be repaired by taking 512 byte of a different
1090 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1091 * area are unreadable.
1092 */
1093 success = 1;
1094 for (page_num = 0; page_num < sblock_bad->page_count;
1095 page_num++) {
1096 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1097 struct scrub_block *sblock_other = NULL;
1098
1099 /* skip no-io-error page in scrub */
1100 if (!page_bad->io_error && !sctx->is_dev_replace)
1101 continue;
1102
1103 if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1104 /*
1105 * In case of dev replace, if raid56 rebuild process
1106 * didn't work out correct data, then copy the content
1107 * in sblock_bad to make sure target device is identical
1108 * to source device, instead of writing garbage data in
1109 * sblock_for_recheck array to target device.
1110 */
1111 sblock_other = NULL;
1112 } else if (page_bad->io_error) {
1113 /* try to find no-io-error page in mirrors */
1114 for (mirror_index = 0;
1115 mirror_index < BTRFS_MAX_MIRRORS &&
1116 sblocks_for_recheck[mirror_index].page_count > 0;
1117 mirror_index++) {
1118 if (!sblocks_for_recheck[mirror_index].
1119 pagev[page_num]->io_error) {
1120 sblock_other = sblocks_for_recheck +
1121 mirror_index;
1122 break;
1123 }
1124 }
1125 if (!sblock_other)
1126 success = 0;
1127 }
1128
1129 if (sctx->is_dev_replace) {
1130 /*
1131 * did not find a mirror to fetch the page
1132 * from. scrub_write_page_to_dev_replace()
1133 * handles this case (page->io_error), by
1134 * filling the block with zeros before
1135 * submitting the write request
1136 */
1137 if (!sblock_other)
1138 sblock_other = sblock_bad;
1139
1140 if (scrub_write_page_to_dev_replace(sblock_other,
1141 page_num) != 0) {
1142 atomic64_inc(
1143 &fs_info->dev_replace.num_write_errors);
1144 success = 0;
1145 }
1146 } else if (sblock_other) {
1147 ret = scrub_repair_page_from_good_copy(sblock_bad,
1148 sblock_other,
1149 page_num, 0);
1150 if (0 == ret)
1151 page_bad->io_error = 0;
1152 else
1153 success = 0;
1154 }
1155 }
1156
1157 if (success && !sctx->is_dev_replace) {
1158 if (is_metadata || have_csum) {
1159 /*
1160 * need to verify the checksum now that all
1161 * sectors on disk are repaired (the write
1162 * request for data to be repaired is on its way).
1163 * Just be lazy and use scrub_recheck_block()
1164 * which re-reads the data before the checksum
1165 * is verified, but most likely the data comes out
1166 * of the page cache.
1167 */
1168 scrub_recheck_block(fs_info, sblock_bad, 1);
1169 if (!sblock_bad->header_error &&
1170 !sblock_bad->checksum_error &&
1171 sblock_bad->no_io_error_seen)
1172 goto corrected_error;
1173 else
1174 goto did_not_correct_error;
1175 } else {
1176corrected_error:
1177 spin_lock(&sctx->stat_lock);
1178 sctx->stat.corrected_errors++;
1179 sblock_to_check->data_corrected = 1;
1180 spin_unlock(&sctx->stat_lock);
1181 btrfs_err_rl_in_rcu(fs_info,
1182 "fixed up error at logical %llu on dev %s",
1183 logical, rcu_str_deref(dev->name));
1184 }
1185 } else {
1186did_not_correct_error:
1187 spin_lock(&sctx->stat_lock);
1188 sctx->stat.uncorrectable_errors++;
1189 spin_unlock(&sctx->stat_lock);
1190 btrfs_err_rl_in_rcu(fs_info,
1191 "unable to fixup (regular) error at logical %llu on dev %s",
1192 logical, rcu_str_deref(dev->name));
1193 }
1194
1195out:
1196 if (sblocks_for_recheck) {
1197 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1198 mirror_index++) {
1199 struct scrub_block *sblock = sblocks_for_recheck +
1200 mirror_index;
1201 struct scrub_recover *recover;
1202 int page_index;
1203
1204 for (page_index = 0; page_index < sblock->page_count;
1205 page_index++) {
1206 sblock->pagev[page_index]->sblock = NULL;
1207 recover = sblock->pagev[page_index]->recover;
1208 if (recover) {
1209 scrub_put_recover(fs_info, recover);
1210 sblock->pagev[page_index]->recover =
1211 NULL;
1212 }
1213 scrub_page_put(sblock->pagev[page_index]);
1214 }
1215 }
1216 kfree(sblocks_for_recheck);
1217 }
1218
1219 ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
1220 memalloc_nofs_restore(nofs_flag);
1221 if (ret < 0)
1222 return ret;
1223 return 0;
1224}
1225
1226static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1227{
1228 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1229 return 2;
1230 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1231 return 3;
1232 else
1233 return (int)bbio->num_stripes;
1234}
1235
1236static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1237 u64 *raid_map,
1238 u64 mapped_length,
1239 int nstripes, int mirror,
1240 int *stripe_index,
1241 u64 *stripe_offset)
1242{
1243 int i;
1244
1245 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1246 /* RAID5/6 */
1247 for (i = 0; i < nstripes; i++) {
1248 if (raid_map[i] == RAID6_Q_STRIPE ||
1249 raid_map[i] == RAID5_P_STRIPE)
1250 continue;
1251
1252 if (logical >= raid_map[i] &&
1253 logical < raid_map[i] + mapped_length)
1254 break;
1255 }
1256
1257 *stripe_index = i;
1258 *stripe_offset = logical - raid_map[i];
1259 } else {
1260 /* The other RAID type */
1261 *stripe_index = mirror;
1262 *stripe_offset = 0;
1263 }
1264}
1265
1266static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1267 struct scrub_block *sblocks_for_recheck)
1268{
1269 struct scrub_ctx *sctx = original_sblock->sctx;
1270 struct btrfs_fs_info *fs_info = sctx->fs_info;
1271 u64 length = original_sblock->page_count * PAGE_SIZE;
1272 u64 logical = original_sblock->pagev[0]->logical;
1273 u64 generation = original_sblock->pagev[0]->generation;
1274 u64 flags = original_sblock->pagev[0]->flags;
1275 u64 have_csum = original_sblock->pagev[0]->have_csum;
1276 struct scrub_recover *recover;
1277 struct btrfs_bio *bbio;
1278 u64 sublen;
1279 u64 mapped_length;
1280 u64 stripe_offset;
1281 int stripe_index;
1282 int page_index = 0;
1283 int mirror_index;
1284 int nmirrors;
1285 int ret;
1286
1287 /*
1288 * note: the two members refs and outstanding_pages
1289 * are not used (and not set) in the blocks that are used for
1290 * the recheck procedure
1291 */
1292
1293 while (length > 0) {
1294 sublen = min_t(u64, length, PAGE_SIZE);
1295 mapped_length = sublen;
1296 bbio = NULL;
1297
1298 /*
1299 * with a length of PAGE_SIZE, each returned stripe
1300 * represents one mirror
1301 */
1302 btrfs_bio_counter_inc_blocked(fs_info);
1303 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1304 logical, &mapped_length, &bbio);
1305 if (ret || !bbio || mapped_length < sublen) {
1306 btrfs_put_bbio(bbio);
1307 btrfs_bio_counter_dec(fs_info);
1308 return -EIO;
1309 }
1310
1311 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1312 if (!recover) {
1313 btrfs_put_bbio(bbio);
1314 btrfs_bio_counter_dec(fs_info);
1315 return -ENOMEM;
1316 }
1317
1318 refcount_set(&recover->refs, 1);
1319 recover->bbio = bbio;
1320 recover->map_length = mapped_length;
1321
1322 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1323
1324 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1325
1326 for (mirror_index = 0; mirror_index < nmirrors;
1327 mirror_index++) {
1328 struct scrub_block *sblock;
1329 struct scrub_page *page;
1330
1331 sblock = sblocks_for_recheck + mirror_index;
1332 sblock->sctx = sctx;
1333
1334 page = kzalloc(sizeof(*page), GFP_NOFS);
1335 if (!page) {
1336leave_nomem:
1337 spin_lock(&sctx->stat_lock);
1338 sctx->stat.malloc_errors++;
1339 spin_unlock(&sctx->stat_lock);
1340 scrub_put_recover(fs_info, recover);
1341 return -ENOMEM;
1342 }
1343 scrub_page_get(page);
1344 sblock->pagev[page_index] = page;
1345 page->sblock = sblock;
1346 page->flags = flags;
1347 page->generation = generation;
1348 page->logical = logical;
1349 page->have_csum = have_csum;
1350 if (have_csum)
1351 memcpy(page->csum,
1352 original_sblock->pagev[0]->csum,
1353 sctx->csum_size);
1354
1355 scrub_stripe_index_and_offset(logical,
1356 bbio->map_type,
1357 bbio->raid_map,
1358 mapped_length,
1359 bbio->num_stripes -
1360 bbio->num_tgtdevs,
1361 mirror_index,
1362 &stripe_index,
1363 &stripe_offset);
1364 page->physical = bbio->stripes[stripe_index].physical +
1365 stripe_offset;
1366 page->dev = bbio->stripes[stripe_index].dev;
1367
1368 BUG_ON(page_index >= original_sblock->page_count);
1369 page->physical_for_dev_replace =
1370 original_sblock->pagev[page_index]->
1371 physical_for_dev_replace;
1372 /* for missing devices, dev->bdev is NULL */
1373 page->mirror_num = mirror_index + 1;
1374 sblock->page_count++;
1375 page->page = alloc_page(GFP_NOFS);
1376 if (!page->page)
1377 goto leave_nomem;
1378
1379 scrub_get_recover(recover);
1380 page->recover = recover;
1381 }
1382 scrub_put_recover(fs_info, recover);
1383 length -= sublen;
1384 logical += sublen;
1385 page_index++;
1386 }
1387
1388 return 0;
1389}
1390
1391static void scrub_bio_wait_endio(struct bio *bio)
1392{
1393 complete(bio->bi_private);
1394}
1395
1396static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1397 struct bio *bio,
1398 struct scrub_page *page)
1399{
1400 DECLARE_COMPLETION_ONSTACK(done);
1401 int ret;
1402 int mirror_num;
1403
1404 bio->bi_iter.bi_sector = page->logical >> 9;
1405 bio->bi_private = &done;
1406 bio->bi_end_io = scrub_bio_wait_endio;
1407
1408 mirror_num = page->sblock->pagev[0]->mirror_num;
1409 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1410 page->recover->map_length,
1411 mirror_num, 0);
1412 if (ret)
1413 return ret;
1414
1415 wait_for_completion_io(&done);
1416 return blk_status_to_errno(bio->bi_status);
1417}
1418
1419static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
1420 struct scrub_block *sblock)
1421{
1422 struct scrub_page *first_page = sblock->pagev[0];
1423 struct bio *bio;
1424 int page_num;
1425
1426 /* All pages in sblock belong to the same stripe on the same device. */
1427 ASSERT(first_page->dev);
1428 if (!first_page->dev->bdev)
1429 goto out;
1430
1431 bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
1432 bio_set_dev(bio, first_page->dev->bdev);
1433
1434 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1435 struct scrub_page *page = sblock->pagev[page_num];
1436
1437 WARN_ON(!page->page);
1438 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1439 }
1440
1441 if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
1442 bio_put(bio);
1443 goto out;
1444 }
1445
1446 bio_put(bio);
1447
1448 scrub_recheck_block_checksum(sblock);
1449
1450 return;
1451out:
1452 for (page_num = 0; page_num < sblock->page_count; page_num++)
1453 sblock->pagev[page_num]->io_error = 1;
1454
1455 sblock->no_io_error_seen = 0;
1456}
1457
1458/*
1459 * this function will check the on disk data for checksum errors, header
1460 * errors and read I/O errors. If any I/O errors happen, the exact pages
1461 * which are errored are marked as being bad. The goal is to enable scrub
1462 * to take those pages that are not errored from all the mirrors so that
1463 * the pages that are errored in the just handled mirror can be repaired.
1464 */
1465static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1466 struct scrub_block *sblock,
1467 int retry_failed_mirror)
1468{
1469 int page_num;
1470
1471 sblock->no_io_error_seen = 1;
1472
1473 /* short cut for raid56 */
1474 if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
1475 return scrub_recheck_block_on_raid56(fs_info, sblock);
1476
1477 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1478 struct bio *bio;
1479 struct scrub_page *page = sblock->pagev[page_num];
1480
1481 if (page->dev->bdev == NULL) {
1482 page->io_error = 1;
1483 sblock->no_io_error_seen = 0;
1484 continue;
1485 }
1486
1487 WARN_ON(!page->page);
1488 bio = btrfs_io_bio_alloc(1);
1489 bio_set_dev(bio, page->dev->bdev);
1490
1491 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1492 bio->bi_iter.bi_sector = page->physical >> 9;
1493 bio->bi_opf = REQ_OP_READ;
1494
1495 if (btrfsic_submit_bio_wait(bio)) {
1496 page->io_error = 1;
1497 sblock->no_io_error_seen = 0;
1498 }
1499
1500 bio_put(bio);
1501 }
1502
1503 if (sblock->no_io_error_seen)
1504 scrub_recheck_block_checksum(sblock);
1505}
1506
1507static inline int scrub_check_fsid(u8 fsid[],
1508 struct scrub_page *spage)
1509{
1510 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1511 int ret;
1512
1513 ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1514 return !ret;
1515}
1516
1517static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1518{
1519 sblock->header_error = 0;
1520 sblock->checksum_error = 0;
1521 sblock->generation_error = 0;
1522
1523 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1524 scrub_checksum_data(sblock);
1525 else
1526 scrub_checksum_tree_block(sblock);
1527}
1528
1529static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1530 struct scrub_block *sblock_good)
1531{
1532 int page_num;
1533 int ret = 0;
1534
1535 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1536 int ret_sub;
1537
1538 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1539 sblock_good,
1540 page_num, 1);
1541 if (ret_sub)
1542 ret = ret_sub;
1543 }
1544
1545 return ret;
1546}
1547
1548static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1549 struct scrub_block *sblock_good,
1550 int page_num, int force_write)
1551{
1552 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1553 struct scrub_page *page_good = sblock_good->pagev[page_num];
1554 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1555
1556 BUG_ON(page_bad->page == NULL);
1557 BUG_ON(page_good->page == NULL);
1558 if (force_write || sblock_bad->header_error ||
1559 sblock_bad->checksum_error || page_bad->io_error) {
1560 struct bio *bio;
1561 int ret;
1562
1563 if (!page_bad->dev->bdev) {
1564 btrfs_warn_rl(fs_info,
1565 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1566 return -EIO;
1567 }
1568
1569 bio = btrfs_io_bio_alloc(1);
1570 bio_set_dev(bio, page_bad->dev->bdev);
1571 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1572 bio->bi_opf = REQ_OP_WRITE;
1573
1574 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1575 if (PAGE_SIZE != ret) {
1576 bio_put(bio);
1577 return -EIO;
1578 }
1579
1580 if (btrfsic_submit_bio_wait(bio)) {
1581 btrfs_dev_stat_inc_and_print(page_bad->dev,
1582 BTRFS_DEV_STAT_WRITE_ERRS);
1583 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1584 bio_put(bio);
1585 return -EIO;
1586 }
1587 bio_put(bio);
1588 }
1589
1590 return 0;
1591}
1592
1593static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1594{
1595 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1596 int page_num;
1597
1598 /*
1599 * This block is used for the check of the parity on the source device,
1600 * so the data needn't be written into the destination device.
1601 */
1602 if (sblock->sparity)
1603 return;
1604
1605 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1606 int ret;
1607
1608 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1609 if (ret)
1610 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1611 }
1612}
1613
1614static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1615 int page_num)
1616{
1617 struct scrub_page *spage = sblock->pagev[page_num];
1618
1619 BUG_ON(spage->page == NULL);
1620 if (spage->io_error) {
1621 void *mapped_buffer = kmap_atomic(spage->page);
1622
1623 clear_page(mapped_buffer);
1624 flush_dcache_page(spage->page);
1625 kunmap_atomic(mapped_buffer);
1626 }
1627 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1628}
1629
1630static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1631 struct scrub_page *spage)
1632{
1633 struct scrub_bio *sbio;
1634 int ret;
1635
1636 mutex_lock(&sctx->wr_lock);
1637again:
1638 if (!sctx->wr_curr_bio) {
1639 sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
1640 GFP_KERNEL);
1641 if (!sctx->wr_curr_bio) {
1642 mutex_unlock(&sctx->wr_lock);
1643 return -ENOMEM;
1644 }
1645 sctx->wr_curr_bio->sctx = sctx;
1646 sctx->wr_curr_bio->page_count = 0;
1647 }
1648 sbio = sctx->wr_curr_bio;
1649 if (sbio->page_count == 0) {
1650 struct bio *bio;
1651
1652 sbio->physical = spage->physical_for_dev_replace;
1653 sbio->logical = spage->logical;
1654 sbio->dev = sctx->wr_tgtdev;
1655 bio = sbio->bio;
1656 if (!bio) {
1657 bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
1658 sbio->bio = bio;
1659 }
1660
1661 bio->bi_private = sbio;
1662 bio->bi_end_io = scrub_wr_bio_end_io;
1663 bio_set_dev(bio, sbio->dev->bdev);
1664 bio->bi_iter.bi_sector = sbio->physical >> 9;
1665 bio->bi_opf = REQ_OP_WRITE;
1666 sbio->status = 0;
1667 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1668 spage->physical_for_dev_replace ||
1669 sbio->logical + sbio->page_count * PAGE_SIZE !=
1670 spage->logical) {
1671 scrub_wr_submit(sctx);
1672 goto again;
1673 }
1674
1675 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1676 if (ret != PAGE_SIZE) {
1677 if (sbio->page_count < 1) {
1678 bio_put(sbio->bio);
1679 sbio->bio = NULL;
1680 mutex_unlock(&sctx->wr_lock);
1681 return -EIO;
1682 }
1683 scrub_wr_submit(sctx);
1684 goto again;
1685 }
1686
1687 sbio->pagev[sbio->page_count] = spage;
1688 scrub_page_get(spage);
1689 sbio->page_count++;
1690 if (sbio->page_count == sctx->pages_per_wr_bio)
1691 scrub_wr_submit(sctx);
1692 mutex_unlock(&sctx->wr_lock);
1693
1694 return 0;
1695}
1696
1697static void scrub_wr_submit(struct scrub_ctx *sctx)
1698{
1699 struct scrub_bio *sbio;
1700
1701 if (!sctx->wr_curr_bio)
1702 return;
1703
1704 sbio = sctx->wr_curr_bio;
1705 sctx->wr_curr_bio = NULL;
1706 WARN_ON(!sbio->bio->bi_disk);
1707 scrub_pending_bio_inc(sctx);
1708 /* process all writes in a single worker thread. Then the block layer
1709 * orders the requests before sending them to the driver which
1710 * doubled the write performance on spinning disks when measured
1711 * with Linux 3.5 */
1712 btrfsic_submit_bio(sbio->bio);
1713}
1714
1715static void scrub_wr_bio_end_io(struct bio *bio)
1716{
1717 struct scrub_bio *sbio = bio->bi_private;
1718 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
1719
1720 sbio->status = bio->bi_status;
1721 sbio->bio = bio;
1722
1723 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1724 scrub_wr_bio_end_io_worker, NULL, NULL);
1725 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1726}
1727
1728static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1729{
1730 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1731 struct scrub_ctx *sctx = sbio->sctx;
1732 int i;
1733
1734 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1735 if (sbio->status) {
1736 struct btrfs_dev_replace *dev_replace =
1737 &sbio->sctx->fs_info->dev_replace;
1738
1739 for (i = 0; i < sbio->page_count; i++) {
1740 struct scrub_page *spage = sbio->pagev[i];
1741
1742 spage->io_error = 1;
1743 atomic64_inc(&dev_replace->num_write_errors);
1744 }
1745 }
1746
1747 for (i = 0; i < sbio->page_count; i++)
1748 scrub_page_put(sbio->pagev[i]);
1749
1750 bio_put(sbio->bio);
1751 kfree(sbio);
1752 scrub_pending_bio_dec(sctx);
1753}
1754
1755static int scrub_checksum(struct scrub_block *sblock)
1756{
1757 u64 flags;
1758 int ret;
1759
1760 /*
1761 * No need to initialize these stats currently,
1762 * because this function only use return value
1763 * instead of these stats value.
1764 *
1765 * Todo:
1766 * always use stats
1767 */
1768 sblock->header_error = 0;
1769 sblock->generation_error = 0;
1770 sblock->checksum_error = 0;
1771
1772 WARN_ON(sblock->page_count < 1);
1773 flags = sblock->pagev[0]->flags;
1774 ret = 0;
1775 if (flags & BTRFS_EXTENT_FLAG_DATA)
1776 ret = scrub_checksum_data(sblock);
1777 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1778 ret = scrub_checksum_tree_block(sblock);
1779 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1780 (void)scrub_checksum_super(sblock);
1781 else
1782 WARN_ON(1);
1783 if (ret)
1784 scrub_handle_errored_block(sblock);
1785
1786 return ret;
1787}
1788
1789static int scrub_checksum_data(struct scrub_block *sblock)
1790{
1791 struct scrub_ctx *sctx = sblock->sctx;
1792 struct btrfs_fs_info *fs_info = sctx->fs_info;
1793 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1794 u8 csum[BTRFS_CSUM_SIZE];
1795 u8 *on_disk_csum;
1796 struct page *page;
1797 void *buffer;
1798 u64 len;
1799 int index;
1800
1801 BUG_ON(sblock->page_count < 1);
1802 if (!sblock->pagev[0]->have_csum)
1803 return 0;
1804
1805 shash->tfm = fs_info->csum_shash;
1806 crypto_shash_init(shash);
1807
1808 on_disk_csum = sblock->pagev[0]->csum;
1809 page = sblock->pagev[0]->page;
1810 buffer = kmap_atomic(page);
1811
1812 len = sctx->fs_info->sectorsize;
1813 index = 0;
1814 for (;;) {
1815 u64 l = min_t(u64, len, PAGE_SIZE);
1816
1817 crypto_shash_update(shash, buffer, l);
1818 kunmap_atomic(buffer);
1819 len -= l;
1820 if (len == 0)
1821 break;
1822 index++;
1823 BUG_ON(index >= sblock->page_count);
1824 BUG_ON(!sblock->pagev[index]->page);
1825 page = sblock->pagev[index]->page;
1826 buffer = kmap_atomic(page);
1827 }
1828
1829 crypto_shash_final(shash, csum);
1830 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1831 sblock->checksum_error = 1;
1832
1833 return sblock->checksum_error;
1834}
1835
1836static int scrub_checksum_tree_block(struct scrub_block *sblock)
1837{
1838 struct scrub_ctx *sctx = sblock->sctx;
1839 struct btrfs_header *h;
1840 struct btrfs_fs_info *fs_info = sctx->fs_info;
1841 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1842 u8 calculated_csum[BTRFS_CSUM_SIZE];
1843 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1844 struct page *page;
1845 void *mapped_buffer;
1846 u64 mapped_size;
1847 void *p;
1848 u64 len;
1849 int index;
1850
1851 shash->tfm = fs_info->csum_shash;
1852 crypto_shash_init(shash);
1853
1854 BUG_ON(sblock->page_count < 1);
1855 page = sblock->pagev[0]->page;
1856 mapped_buffer = kmap_atomic(page);
1857 h = (struct btrfs_header *)mapped_buffer;
1858 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1859
1860 /*
1861 * we don't use the getter functions here, as we
1862 * a) don't have an extent buffer and
1863 * b) the page is already kmapped
1864 */
1865 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1866 sblock->header_error = 1;
1867
1868 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1869 sblock->header_error = 1;
1870 sblock->generation_error = 1;
1871 }
1872
1873 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1874 sblock->header_error = 1;
1875
1876 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1877 BTRFS_UUID_SIZE))
1878 sblock->header_error = 1;
1879
1880 len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
1881 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1882 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1883 index = 0;
1884 for (;;) {
1885 u64 l = min_t(u64, len, mapped_size);
1886
1887 crypto_shash_update(shash, p, l);
1888 kunmap_atomic(mapped_buffer);
1889 len -= l;
1890 if (len == 0)
1891 break;
1892 index++;
1893 BUG_ON(index >= sblock->page_count);
1894 BUG_ON(!sblock->pagev[index]->page);
1895 page = sblock->pagev[index]->page;
1896 mapped_buffer = kmap_atomic(page);
1897 mapped_size = PAGE_SIZE;
1898 p = mapped_buffer;
1899 }
1900
1901 crypto_shash_final(shash, calculated_csum);
1902 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1903 sblock->checksum_error = 1;
1904
1905 return sblock->header_error || sblock->checksum_error;
1906}
1907
1908static int scrub_checksum_super(struct scrub_block *sblock)
1909{
1910 struct btrfs_super_block *s;
1911 struct scrub_ctx *sctx = sblock->sctx;
1912 struct btrfs_fs_info *fs_info = sctx->fs_info;
1913 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1914 u8 calculated_csum[BTRFS_CSUM_SIZE];
1915 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1916 struct page *page;
1917 void *mapped_buffer;
1918 u64 mapped_size;
1919 void *p;
1920 int fail_gen = 0;
1921 int fail_cor = 0;
1922 u64 len;
1923 int index;
1924
1925 shash->tfm = fs_info->csum_shash;
1926 crypto_shash_init(shash);
1927
1928 BUG_ON(sblock->page_count < 1);
1929 page = sblock->pagev[0]->page;
1930 mapped_buffer = kmap_atomic(page);
1931 s = (struct btrfs_super_block *)mapped_buffer;
1932 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1933
1934 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1935 ++fail_cor;
1936
1937 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1938 ++fail_gen;
1939
1940 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1941 ++fail_cor;
1942
1943 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1944 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1945 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1946 index = 0;
1947 for (;;) {
1948 u64 l = min_t(u64, len, mapped_size);
1949
1950 crypto_shash_update(shash, p, l);
1951 kunmap_atomic(mapped_buffer);
1952 len -= l;
1953 if (len == 0)
1954 break;
1955 index++;
1956 BUG_ON(index >= sblock->page_count);
1957 BUG_ON(!sblock->pagev[index]->page);
1958 page = sblock->pagev[index]->page;
1959 mapped_buffer = kmap_atomic(page);
1960 mapped_size = PAGE_SIZE;
1961 p = mapped_buffer;
1962 }
1963
1964 crypto_shash_final(shash, calculated_csum);
1965 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1966 ++fail_cor;
1967
1968 if (fail_cor + fail_gen) {
1969 /*
1970 * if we find an error in a super block, we just report it.
1971 * They will get written with the next transaction commit
1972 * anyway
1973 */
1974 spin_lock(&sctx->stat_lock);
1975 ++sctx->stat.super_errors;
1976 spin_unlock(&sctx->stat_lock);
1977 if (fail_cor)
1978 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1979 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1980 else
1981 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1982 BTRFS_DEV_STAT_GENERATION_ERRS);
1983 }
1984
1985 return fail_cor + fail_gen;
1986}
1987
1988static void scrub_block_get(struct scrub_block *sblock)
1989{
1990 refcount_inc(&sblock->refs);
1991}
1992
1993static void scrub_block_put(struct scrub_block *sblock)
1994{
1995 if (refcount_dec_and_test(&sblock->refs)) {
1996 int i;
1997
1998 if (sblock->sparity)
1999 scrub_parity_put(sblock->sparity);
2000
2001 for (i = 0; i < sblock->page_count; i++)
2002 scrub_page_put(sblock->pagev[i]);
2003 kfree(sblock);
2004 }
2005}
2006
2007static void scrub_page_get(struct scrub_page *spage)
2008{
2009 atomic_inc(&spage->refs);
2010}
2011
2012static void scrub_page_put(struct scrub_page *spage)
2013{
2014 if (atomic_dec_and_test(&spage->refs)) {
2015 if (spage->page)
2016 __free_page(spage->page);
2017 kfree(spage);
2018 }
2019}
2020
2021static void scrub_submit(struct scrub_ctx *sctx)
2022{
2023 struct scrub_bio *sbio;
2024
2025 if (sctx->curr == -1)
2026 return;
2027
2028 sbio = sctx->bios[sctx->curr];
2029 sctx->curr = -1;
2030 scrub_pending_bio_inc(sctx);
2031 btrfsic_submit_bio(sbio->bio);
2032}
2033
2034static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2035 struct scrub_page *spage)
2036{
2037 struct scrub_block *sblock = spage->sblock;
2038 struct scrub_bio *sbio;
2039 int ret;
2040
2041again:
2042 /*
2043 * grab a fresh bio or wait for one to become available
2044 */
2045 while (sctx->curr == -1) {
2046 spin_lock(&sctx->list_lock);
2047 sctx->curr = sctx->first_free;
2048 if (sctx->curr != -1) {
2049 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2050 sctx->bios[sctx->curr]->next_free = -1;
2051 sctx->bios[sctx->curr]->page_count = 0;
2052 spin_unlock(&sctx->list_lock);
2053 } else {
2054 spin_unlock(&sctx->list_lock);
2055 wait_event(sctx->list_wait, sctx->first_free != -1);
2056 }
2057 }
2058 sbio = sctx->bios[sctx->curr];
2059 if (sbio->page_count == 0) {
2060 struct bio *bio;
2061
2062 sbio->physical = spage->physical;
2063 sbio->logical = spage->logical;
2064 sbio->dev = spage->dev;
2065 bio = sbio->bio;
2066 if (!bio) {
2067 bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
2068 sbio->bio = bio;
2069 }
2070
2071 bio->bi_private = sbio;
2072 bio->bi_end_io = scrub_bio_end_io;
2073 bio_set_dev(bio, sbio->dev->bdev);
2074 bio->bi_iter.bi_sector = sbio->physical >> 9;
2075 bio->bi_opf = REQ_OP_READ;
2076 sbio->status = 0;
2077 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2078 spage->physical ||
2079 sbio->logical + sbio->page_count * PAGE_SIZE !=
2080 spage->logical ||
2081 sbio->dev != spage->dev) {
2082 scrub_submit(sctx);
2083 goto again;
2084 }
2085
2086 sbio->pagev[sbio->page_count] = spage;
2087 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2088 if (ret != PAGE_SIZE) {
2089 if (sbio->page_count < 1) {
2090 bio_put(sbio->bio);
2091 sbio->bio = NULL;
2092 return -EIO;
2093 }
2094 scrub_submit(sctx);
2095 goto again;
2096 }
2097
2098 scrub_block_get(sblock); /* one for the page added to the bio */
2099 atomic_inc(&sblock->outstanding_pages);
2100 sbio->page_count++;
2101 if (sbio->page_count == sctx->pages_per_rd_bio)
2102 scrub_submit(sctx);
2103
2104 return 0;
2105}
2106
2107static void scrub_missing_raid56_end_io(struct bio *bio)
2108{
2109 struct scrub_block *sblock = bio->bi_private;
2110 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2111
2112 if (bio->bi_status)
2113 sblock->no_io_error_seen = 0;
2114
2115 bio_put(bio);
2116
2117 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2118}
2119
2120static void scrub_missing_raid56_worker(struct btrfs_work *work)
2121{
2122 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2123 struct scrub_ctx *sctx = sblock->sctx;
2124 struct btrfs_fs_info *fs_info = sctx->fs_info;
2125 u64 logical;
2126 struct btrfs_device *dev;
2127
2128 logical = sblock->pagev[0]->logical;
2129 dev = sblock->pagev[0]->dev;
2130
2131 if (sblock->no_io_error_seen)
2132 scrub_recheck_block_checksum(sblock);
2133
2134 if (!sblock->no_io_error_seen) {
2135 spin_lock(&sctx->stat_lock);
2136 sctx->stat.read_errors++;
2137 spin_unlock(&sctx->stat_lock);
2138 btrfs_err_rl_in_rcu(fs_info,
2139 "IO error rebuilding logical %llu for dev %s",
2140 logical, rcu_str_deref(dev->name));
2141 } else if (sblock->header_error || sblock->checksum_error) {
2142 spin_lock(&sctx->stat_lock);
2143 sctx->stat.uncorrectable_errors++;
2144 spin_unlock(&sctx->stat_lock);
2145 btrfs_err_rl_in_rcu(fs_info,
2146 "failed to rebuild valid logical %llu for dev %s",
2147 logical, rcu_str_deref(dev->name));
2148 } else {
2149 scrub_write_block_to_dev_replace(sblock);
2150 }
2151
2152 scrub_block_put(sblock);
2153
2154 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2155 mutex_lock(&sctx->wr_lock);
2156 scrub_wr_submit(sctx);
2157 mutex_unlock(&sctx->wr_lock);
2158 }
2159
2160 scrub_pending_bio_dec(sctx);
2161}
2162
2163static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2164{
2165 struct scrub_ctx *sctx = sblock->sctx;
2166 struct btrfs_fs_info *fs_info = sctx->fs_info;
2167 u64 length = sblock->page_count * PAGE_SIZE;
2168 u64 logical = sblock->pagev[0]->logical;
2169 struct btrfs_bio *bbio = NULL;
2170 struct bio *bio;
2171 struct btrfs_raid_bio *rbio;
2172 int ret;
2173 int i;
2174
2175 btrfs_bio_counter_inc_blocked(fs_info);
2176 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2177 &length, &bbio);
2178 if (ret || !bbio || !bbio->raid_map)
2179 goto bbio_out;
2180
2181 if (WARN_ON(!sctx->is_dev_replace ||
2182 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2183 /*
2184 * We shouldn't be scrubbing a missing device. Even for dev
2185 * replace, we should only get here for RAID 5/6. We either
2186 * managed to mount something with no mirrors remaining or
2187 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2188 */
2189 goto bbio_out;
2190 }
2191
2192 bio = btrfs_io_bio_alloc(0);
2193 bio->bi_iter.bi_sector = logical >> 9;
2194 bio->bi_private = sblock;
2195 bio->bi_end_io = scrub_missing_raid56_end_io;
2196
2197 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2198 if (!rbio)
2199 goto rbio_out;
2200
2201 for (i = 0; i < sblock->page_count; i++) {
2202 struct scrub_page *spage = sblock->pagev[i];
2203
2204 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2205 }
2206
2207 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2208 scrub_missing_raid56_worker, NULL, NULL);
2209 scrub_block_get(sblock);
2210 scrub_pending_bio_inc(sctx);
2211 raid56_submit_missing_rbio(rbio);
2212 return;
2213
2214rbio_out:
2215 bio_put(bio);
2216bbio_out:
2217 btrfs_bio_counter_dec(fs_info);
2218 btrfs_put_bbio(bbio);
2219 spin_lock(&sctx->stat_lock);
2220 sctx->stat.malloc_errors++;
2221 spin_unlock(&sctx->stat_lock);
2222}
2223
2224static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2225 u64 physical, struct btrfs_device *dev, u64 flags,
2226 u64 gen, int mirror_num, u8 *csum, int force,
2227 u64 physical_for_dev_replace)
2228{
2229 struct scrub_block *sblock;
2230 int index;
2231
2232 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2233 if (!sblock) {
2234 spin_lock(&sctx->stat_lock);
2235 sctx->stat.malloc_errors++;
2236 spin_unlock(&sctx->stat_lock);
2237 return -ENOMEM;
2238 }
2239
2240 /* one ref inside this function, plus one for each page added to
2241 * a bio later on */
2242 refcount_set(&sblock->refs, 1);
2243 sblock->sctx = sctx;
2244 sblock->no_io_error_seen = 1;
2245
2246 for (index = 0; len > 0; index++) {
2247 struct scrub_page *spage;
2248 u64 l = min_t(u64, len, PAGE_SIZE);
2249
2250 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2251 if (!spage) {
2252leave_nomem:
2253 spin_lock(&sctx->stat_lock);
2254 sctx->stat.malloc_errors++;
2255 spin_unlock(&sctx->stat_lock);
2256 scrub_block_put(sblock);
2257 return -ENOMEM;
2258 }
2259 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2260 scrub_page_get(spage);
2261 sblock->pagev[index] = spage;
2262 spage->sblock = sblock;
2263 spage->dev = dev;
2264 spage->flags = flags;
2265 spage->generation = gen;
2266 spage->logical = logical;
2267 spage->physical = physical;
2268 spage->physical_for_dev_replace = physical_for_dev_replace;
2269 spage->mirror_num = mirror_num;
2270 if (csum) {
2271 spage->have_csum = 1;
2272 memcpy(spage->csum, csum, sctx->csum_size);
2273 } else {
2274 spage->have_csum = 0;
2275 }
2276 sblock->page_count++;
2277 spage->page = alloc_page(GFP_KERNEL);
2278 if (!spage->page)
2279 goto leave_nomem;
2280 len -= l;
2281 logical += l;
2282 physical += l;
2283 physical_for_dev_replace += l;
2284 }
2285
2286 WARN_ON(sblock->page_count == 0);
2287 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2288 /*
2289 * This case should only be hit for RAID 5/6 device replace. See
2290 * the comment in scrub_missing_raid56_pages() for details.
2291 */
2292 scrub_missing_raid56_pages(sblock);
2293 } else {
2294 for (index = 0; index < sblock->page_count; index++) {
2295 struct scrub_page *spage = sblock->pagev[index];
2296 int ret;
2297
2298 ret = scrub_add_page_to_rd_bio(sctx, spage);
2299 if (ret) {
2300 scrub_block_put(sblock);
2301 return ret;
2302 }
2303 }
2304
2305 if (force)
2306 scrub_submit(sctx);
2307 }
2308
2309 /* last one frees, either here or in bio completion for last page */
2310 scrub_block_put(sblock);
2311 return 0;
2312}
2313
2314static void scrub_bio_end_io(struct bio *bio)
2315{
2316 struct scrub_bio *sbio = bio->bi_private;
2317 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2318
2319 sbio->status = bio->bi_status;
2320 sbio->bio = bio;
2321
2322 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2323}
2324
2325static void scrub_bio_end_io_worker(struct btrfs_work *work)
2326{
2327 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2328 struct scrub_ctx *sctx = sbio->sctx;
2329 int i;
2330
2331 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2332 if (sbio->status) {
2333 for (i = 0; i < sbio->page_count; i++) {
2334 struct scrub_page *spage = sbio->pagev[i];
2335
2336 spage->io_error = 1;
2337 spage->sblock->no_io_error_seen = 0;
2338 }
2339 }
2340
2341 /* now complete the scrub_block items that have all pages completed */
2342 for (i = 0; i < sbio->page_count; i++) {
2343 struct scrub_page *spage = sbio->pagev[i];
2344 struct scrub_block *sblock = spage->sblock;
2345
2346 if (atomic_dec_and_test(&sblock->outstanding_pages))
2347 scrub_block_complete(sblock);
2348 scrub_block_put(sblock);
2349 }
2350
2351 bio_put(sbio->bio);
2352 sbio->bio = NULL;
2353 spin_lock(&sctx->list_lock);
2354 sbio->next_free = sctx->first_free;
2355 sctx->first_free = sbio->index;
2356 spin_unlock(&sctx->list_lock);
2357
2358 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2359 mutex_lock(&sctx->wr_lock);
2360 scrub_wr_submit(sctx);
2361 mutex_unlock(&sctx->wr_lock);
2362 }
2363
2364 scrub_pending_bio_dec(sctx);
2365}
2366
2367static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2368 unsigned long *bitmap,
2369 u64 start, u64 len)
2370{
2371 u64 offset;
2372 u64 nsectors64;
2373 u32 nsectors;
2374 int sectorsize = sparity->sctx->fs_info->sectorsize;
2375
2376 if (len >= sparity->stripe_len) {
2377 bitmap_set(bitmap, 0, sparity->nsectors);
2378 return;
2379 }
2380
2381 start -= sparity->logic_start;
2382 start = div64_u64_rem(start, sparity->stripe_len, &offset);
2383 offset = div_u64(offset, sectorsize);
2384 nsectors64 = div_u64(len, sectorsize);
2385
2386 ASSERT(nsectors64 < UINT_MAX);
2387 nsectors = (u32)nsectors64;
2388
2389 if (offset + nsectors <= sparity->nsectors) {
2390 bitmap_set(bitmap, offset, nsectors);
2391 return;
2392 }
2393
2394 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2395 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2396}
2397
2398static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2399 u64 start, u64 len)
2400{
2401 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2402}
2403
2404static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2405 u64 start, u64 len)
2406{
2407 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2408}
2409
2410static void scrub_block_complete(struct scrub_block *sblock)
2411{
2412 int corrupted = 0;
2413
2414 if (!sblock->no_io_error_seen) {
2415 corrupted = 1;
2416 scrub_handle_errored_block(sblock);
2417 } else {
2418 /*
2419 * if has checksum error, write via repair mechanism in
2420 * dev replace case, otherwise write here in dev replace
2421 * case.
2422 */
2423 corrupted = scrub_checksum(sblock);
2424 if (!corrupted && sblock->sctx->is_dev_replace)
2425 scrub_write_block_to_dev_replace(sblock);
2426 }
2427
2428 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2429 u64 start = sblock->pagev[0]->logical;
2430 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2431 PAGE_SIZE;
2432
2433 scrub_parity_mark_sectors_error(sblock->sparity,
2434 start, end - start);
2435 }
2436}
2437
2438static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2439{
2440 struct btrfs_ordered_sum *sum = NULL;
2441 unsigned long index;
2442 unsigned long num_sectors;
2443
2444 while (!list_empty(&sctx->csum_list)) {
2445 sum = list_first_entry(&sctx->csum_list,
2446 struct btrfs_ordered_sum, list);
2447 if (sum->bytenr > logical)
2448 return 0;
2449 if (sum->bytenr + sum->len > logical)
2450 break;
2451
2452 ++sctx->stat.csum_discards;
2453 list_del(&sum->list);
2454 kfree(sum);
2455 sum = NULL;
2456 }
2457 if (!sum)
2458 return 0;
2459
2460 index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
2461 ASSERT(index < UINT_MAX);
2462
2463 num_sectors = sum->len / sctx->fs_info->sectorsize;
2464 memcpy(csum, sum->sums + index * sctx->csum_size, sctx->csum_size);
2465 if (index == num_sectors - 1) {
2466 list_del(&sum->list);
2467 kfree(sum);
2468 }
2469 return 1;
2470}
2471
2472/* scrub extent tries to collect up to 64 kB for each bio */
2473static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
2474 u64 logical, u64 len,
2475 u64 physical, struct btrfs_device *dev, u64 flags,
2476 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2477{
2478 int ret;
2479 u8 csum[BTRFS_CSUM_SIZE];
2480 u32 blocksize;
2481
2482 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2483 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2484 blocksize = map->stripe_len;
2485 else
2486 blocksize = sctx->fs_info->sectorsize;
2487 spin_lock(&sctx->stat_lock);
2488 sctx->stat.data_extents_scrubbed++;
2489 sctx->stat.data_bytes_scrubbed += len;
2490 spin_unlock(&sctx->stat_lock);
2491 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2492 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2493 blocksize = map->stripe_len;
2494 else
2495 blocksize = sctx->fs_info->nodesize;
2496 spin_lock(&sctx->stat_lock);
2497 sctx->stat.tree_extents_scrubbed++;
2498 sctx->stat.tree_bytes_scrubbed += len;
2499 spin_unlock(&sctx->stat_lock);
2500 } else {
2501 blocksize = sctx->fs_info->sectorsize;
2502 WARN_ON(1);
2503 }
2504
2505 while (len) {
2506 u64 l = min_t(u64, len, blocksize);
2507 int have_csum = 0;
2508
2509 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2510 /* push csums to sbio */
2511 have_csum = scrub_find_csum(sctx, logical, csum);
2512 if (have_csum == 0)
2513 ++sctx->stat.no_csum;
2514 }
2515 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2516 mirror_num, have_csum ? csum : NULL, 0,
2517 physical_for_dev_replace);
2518 if (ret)
2519 return ret;
2520 len -= l;
2521 logical += l;
2522 physical += l;
2523 physical_for_dev_replace += l;
2524 }
2525 return 0;
2526}
2527
2528static int scrub_pages_for_parity(struct scrub_parity *sparity,
2529 u64 logical, u64 len,
2530 u64 physical, struct btrfs_device *dev,
2531 u64 flags, u64 gen, int mirror_num, u8 *csum)
2532{
2533 struct scrub_ctx *sctx = sparity->sctx;
2534 struct scrub_block *sblock;
2535 int index;
2536
2537 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2538 if (!sblock) {
2539 spin_lock(&sctx->stat_lock);
2540 sctx->stat.malloc_errors++;
2541 spin_unlock(&sctx->stat_lock);
2542 return -ENOMEM;
2543 }
2544
2545 /* one ref inside this function, plus one for each page added to
2546 * a bio later on */
2547 refcount_set(&sblock->refs, 1);
2548 sblock->sctx = sctx;
2549 sblock->no_io_error_seen = 1;
2550 sblock->sparity = sparity;
2551 scrub_parity_get(sparity);
2552
2553 for (index = 0; len > 0; index++) {
2554 struct scrub_page *spage;
2555 u64 l = min_t(u64, len, PAGE_SIZE);
2556
2557 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2558 if (!spage) {
2559leave_nomem:
2560 spin_lock(&sctx->stat_lock);
2561 sctx->stat.malloc_errors++;
2562 spin_unlock(&sctx->stat_lock);
2563 scrub_block_put(sblock);
2564 return -ENOMEM;
2565 }
2566 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2567 /* For scrub block */
2568 scrub_page_get(spage);
2569 sblock->pagev[index] = spage;
2570 /* For scrub parity */
2571 scrub_page_get(spage);
2572 list_add_tail(&spage->list, &sparity->spages);
2573 spage->sblock = sblock;
2574 spage->dev = dev;
2575 spage->flags = flags;
2576 spage->generation = gen;
2577 spage->logical = logical;
2578 spage->physical = physical;
2579 spage->mirror_num = mirror_num;
2580 if (csum) {
2581 spage->have_csum = 1;
2582 memcpy(spage->csum, csum, sctx->csum_size);
2583 } else {
2584 spage->have_csum = 0;
2585 }
2586 sblock->page_count++;
2587 spage->page = alloc_page(GFP_KERNEL);
2588 if (!spage->page)
2589 goto leave_nomem;
2590 len -= l;
2591 logical += l;
2592 physical += l;
2593 }
2594
2595 WARN_ON(sblock->page_count == 0);
2596 for (index = 0; index < sblock->page_count; index++) {
2597 struct scrub_page *spage = sblock->pagev[index];
2598 int ret;
2599
2600 ret = scrub_add_page_to_rd_bio(sctx, spage);
2601 if (ret) {
2602 scrub_block_put(sblock);
2603 return ret;
2604 }
2605 }
2606
2607 /* last one frees, either here or in bio completion for last page */
2608 scrub_block_put(sblock);
2609 return 0;
2610}
2611
2612static int scrub_extent_for_parity(struct scrub_parity *sparity,
2613 u64 logical, u64 len,
2614 u64 physical, struct btrfs_device *dev,
2615 u64 flags, u64 gen, int mirror_num)
2616{
2617 struct scrub_ctx *sctx = sparity->sctx;
2618 int ret;
2619 u8 csum[BTRFS_CSUM_SIZE];
2620 u32 blocksize;
2621
2622 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2623 scrub_parity_mark_sectors_error(sparity, logical, len);
2624 return 0;
2625 }
2626
2627 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2628 blocksize = sparity->stripe_len;
2629 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2630 blocksize = sparity->stripe_len;
2631 } else {
2632 blocksize = sctx->fs_info->sectorsize;
2633 WARN_ON(1);
2634 }
2635
2636 while (len) {
2637 u64 l = min_t(u64, len, blocksize);
2638 int have_csum = 0;
2639
2640 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2641 /* push csums to sbio */
2642 have_csum = scrub_find_csum(sctx, logical, csum);
2643 if (have_csum == 0)
2644 goto skip;
2645 }
2646 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2647 flags, gen, mirror_num,
2648 have_csum ? csum : NULL);
2649 if (ret)
2650 return ret;
2651skip:
2652 len -= l;
2653 logical += l;
2654 physical += l;
2655 }
2656 return 0;
2657}
2658
2659/*
2660 * Given a physical address, this will calculate it's
2661 * logical offset. if this is a parity stripe, it will return
2662 * the most left data stripe's logical offset.
2663 *
2664 * return 0 if it is a data stripe, 1 means parity stripe.
2665 */
2666static int get_raid56_logic_offset(u64 physical, int num,
2667 struct map_lookup *map, u64 *offset,
2668 u64 *stripe_start)
2669{
2670 int i;
2671 int j = 0;
2672 u64 stripe_nr;
2673 u64 last_offset;
2674 u32 stripe_index;
2675 u32 rot;
2676 const int data_stripes = nr_data_stripes(map);
2677
2678 last_offset = (physical - map->stripes[num].physical) * data_stripes;
2679 if (stripe_start)
2680 *stripe_start = last_offset;
2681
2682 *offset = last_offset;
2683 for (i = 0; i < data_stripes; i++) {
2684 *offset = last_offset + i * map->stripe_len;
2685
2686 stripe_nr = div64_u64(*offset, map->stripe_len);
2687 stripe_nr = div_u64(stripe_nr, data_stripes);
2688
2689 /* Work out the disk rotation on this stripe-set */
2690 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2691 /* calculate which stripe this data locates */
2692 rot += i;
2693 stripe_index = rot % map->num_stripes;
2694 if (stripe_index == num)
2695 return 0;
2696 if (stripe_index < num)
2697 j++;
2698 }
2699 *offset = last_offset + j * map->stripe_len;
2700 return 1;
2701}
2702
2703static void scrub_free_parity(struct scrub_parity *sparity)
2704{
2705 struct scrub_ctx *sctx = sparity->sctx;
2706 struct scrub_page *curr, *next;
2707 int nbits;
2708
2709 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2710 if (nbits) {
2711 spin_lock(&sctx->stat_lock);
2712 sctx->stat.read_errors += nbits;
2713 sctx->stat.uncorrectable_errors += nbits;
2714 spin_unlock(&sctx->stat_lock);
2715 }
2716
2717 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2718 list_del_init(&curr->list);
2719 scrub_page_put(curr);
2720 }
2721
2722 kfree(sparity);
2723}
2724
2725static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2726{
2727 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2728 work);
2729 struct scrub_ctx *sctx = sparity->sctx;
2730
2731 scrub_free_parity(sparity);
2732 scrub_pending_bio_dec(sctx);
2733}
2734
2735static void scrub_parity_bio_endio(struct bio *bio)
2736{
2737 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2738 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2739
2740 if (bio->bi_status)
2741 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2742 sparity->nsectors);
2743
2744 bio_put(bio);
2745
2746 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2747 scrub_parity_bio_endio_worker, NULL, NULL);
2748 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2749}
2750
2751static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2752{
2753 struct scrub_ctx *sctx = sparity->sctx;
2754 struct btrfs_fs_info *fs_info = sctx->fs_info;
2755 struct bio *bio;
2756 struct btrfs_raid_bio *rbio;
2757 struct btrfs_bio *bbio = NULL;
2758 u64 length;
2759 int ret;
2760
2761 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2762 sparity->nsectors))
2763 goto out;
2764
2765 length = sparity->logic_end - sparity->logic_start;
2766
2767 btrfs_bio_counter_inc_blocked(fs_info);
2768 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2769 &length, &bbio);
2770 if (ret || !bbio || !bbio->raid_map)
2771 goto bbio_out;
2772
2773 bio = btrfs_io_bio_alloc(0);
2774 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2775 bio->bi_private = sparity;
2776 bio->bi_end_io = scrub_parity_bio_endio;
2777
2778 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2779 length, sparity->scrub_dev,
2780 sparity->dbitmap,
2781 sparity->nsectors);
2782 if (!rbio)
2783 goto rbio_out;
2784
2785 scrub_pending_bio_inc(sctx);
2786 raid56_parity_submit_scrub_rbio(rbio);
2787 return;
2788
2789rbio_out:
2790 bio_put(bio);
2791bbio_out:
2792 btrfs_bio_counter_dec(fs_info);
2793 btrfs_put_bbio(bbio);
2794 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2795 sparity->nsectors);
2796 spin_lock(&sctx->stat_lock);
2797 sctx->stat.malloc_errors++;
2798 spin_unlock(&sctx->stat_lock);
2799out:
2800 scrub_free_parity(sparity);
2801}
2802
2803static inline int scrub_calc_parity_bitmap_len(int nsectors)
2804{
2805 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2806}
2807
2808static void scrub_parity_get(struct scrub_parity *sparity)
2809{
2810 refcount_inc(&sparity->refs);
2811}
2812
2813static void scrub_parity_put(struct scrub_parity *sparity)
2814{
2815 if (!refcount_dec_and_test(&sparity->refs))
2816 return;
2817
2818 scrub_parity_check_and_repair(sparity);
2819}
2820
2821static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2822 struct map_lookup *map,
2823 struct btrfs_device *sdev,
2824 struct btrfs_path *path,
2825 u64 logic_start,
2826 u64 logic_end)
2827{
2828 struct btrfs_fs_info *fs_info = sctx->fs_info;
2829 struct btrfs_root *root = fs_info->extent_root;
2830 struct btrfs_root *csum_root = fs_info->csum_root;
2831 struct btrfs_extent_item *extent;
2832 struct btrfs_bio *bbio = NULL;
2833 u64 flags;
2834 int ret;
2835 int slot;
2836 struct extent_buffer *l;
2837 struct btrfs_key key;
2838 u64 generation;
2839 u64 extent_logical;
2840 u64 extent_physical;
2841 u64 extent_len;
2842 u64 mapped_length;
2843 struct btrfs_device *extent_dev;
2844 struct scrub_parity *sparity;
2845 int nsectors;
2846 int bitmap_len;
2847 int extent_mirror_num;
2848 int stop_loop = 0;
2849
2850 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2851 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2852 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2853 GFP_NOFS);
2854 if (!sparity) {
2855 spin_lock(&sctx->stat_lock);
2856 sctx->stat.malloc_errors++;
2857 spin_unlock(&sctx->stat_lock);
2858 return -ENOMEM;
2859 }
2860
2861 sparity->stripe_len = map->stripe_len;
2862 sparity->nsectors = nsectors;
2863 sparity->sctx = sctx;
2864 sparity->scrub_dev = sdev;
2865 sparity->logic_start = logic_start;
2866 sparity->logic_end = logic_end;
2867 refcount_set(&sparity->refs, 1);
2868 INIT_LIST_HEAD(&sparity->spages);
2869 sparity->dbitmap = sparity->bitmap;
2870 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2871
2872 ret = 0;
2873 while (logic_start < logic_end) {
2874 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2875 key.type = BTRFS_METADATA_ITEM_KEY;
2876 else
2877 key.type = BTRFS_EXTENT_ITEM_KEY;
2878 key.objectid = logic_start;
2879 key.offset = (u64)-1;
2880
2881 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2882 if (ret < 0)
2883 goto out;
2884
2885 if (ret > 0) {
2886 ret = btrfs_previous_extent_item(root, path, 0);
2887 if (ret < 0)
2888 goto out;
2889 if (ret > 0) {
2890 btrfs_release_path(path);
2891 ret = btrfs_search_slot(NULL, root, &key,
2892 path, 0, 0);
2893 if (ret < 0)
2894 goto out;
2895 }
2896 }
2897
2898 stop_loop = 0;
2899 while (1) {
2900 u64 bytes;
2901
2902 l = path->nodes[0];
2903 slot = path->slots[0];
2904 if (slot >= btrfs_header_nritems(l)) {
2905 ret = btrfs_next_leaf(root, path);
2906 if (ret == 0)
2907 continue;
2908 if (ret < 0)
2909 goto out;
2910
2911 stop_loop = 1;
2912 break;
2913 }
2914 btrfs_item_key_to_cpu(l, &key, slot);
2915
2916 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2917 key.type != BTRFS_METADATA_ITEM_KEY)
2918 goto next;
2919
2920 if (key.type == BTRFS_METADATA_ITEM_KEY)
2921 bytes = fs_info->nodesize;
2922 else
2923 bytes = key.offset;
2924
2925 if (key.objectid + bytes <= logic_start)
2926 goto next;
2927
2928 if (key.objectid >= logic_end) {
2929 stop_loop = 1;
2930 break;
2931 }
2932
2933 while (key.objectid >= logic_start + map->stripe_len)
2934 logic_start += map->stripe_len;
2935
2936 extent = btrfs_item_ptr(l, slot,
2937 struct btrfs_extent_item);
2938 flags = btrfs_extent_flags(l, extent);
2939 generation = btrfs_extent_generation(l, extent);
2940
2941 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2942 (key.objectid < logic_start ||
2943 key.objectid + bytes >
2944 logic_start + map->stripe_len)) {
2945 btrfs_err(fs_info,
2946 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2947 key.objectid, logic_start);
2948 spin_lock(&sctx->stat_lock);
2949 sctx->stat.uncorrectable_errors++;
2950 spin_unlock(&sctx->stat_lock);
2951 goto next;
2952 }
2953again:
2954 extent_logical = key.objectid;
2955 extent_len = bytes;
2956
2957 if (extent_logical < logic_start) {
2958 extent_len -= logic_start - extent_logical;
2959 extent_logical = logic_start;
2960 }
2961
2962 if (extent_logical + extent_len >
2963 logic_start + map->stripe_len)
2964 extent_len = logic_start + map->stripe_len -
2965 extent_logical;
2966
2967 scrub_parity_mark_sectors_data(sparity, extent_logical,
2968 extent_len);
2969
2970 mapped_length = extent_len;
2971 bbio = NULL;
2972 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2973 extent_logical, &mapped_length, &bbio,
2974 0);
2975 if (!ret) {
2976 if (!bbio || mapped_length < extent_len)
2977 ret = -EIO;
2978 }
2979 if (ret) {
2980 btrfs_put_bbio(bbio);
2981 goto out;
2982 }
2983 extent_physical = bbio->stripes[0].physical;
2984 extent_mirror_num = bbio->mirror_num;
2985 extent_dev = bbio->stripes[0].dev;
2986 btrfs_put_bbio(bbio);
2987
2988 ret = btrfs_lookup_csums_range(csum_root,
2989 extent_logical,
2990 extent_logical + extent_len - 1,
2991 &sctx->csum_list, 1);
2992 if (ret)
2993 goto out;
2994
2995 ret = scrub_extent_for_parity(sparity, extent_logical,
2996 extent_len,
2997 extent_physical,
2998 extent_dev, flags,
2999 generation,
3000 extent_mirror_num);
3001
3002 scrub_free_csums(sctx);
3003
3004 if (ret)
3005 goto out;
3006
3007 if (extent_logical + extent_len <
3008 key.objectid + bytes) {
3009 logic_start += map->stripe_len;
3010
3011 if (logic_start >= logic_end) {
3012 stop_loop = 1;
3013 break;
3014 }
3015
3016 if (logic_start < key.objectid + bytes) {
3017 cond_resched();
3018 goto again;
3019 }
3020 }
3021next:
3022 path->slots[0]++;
3023 }
3024
3025 btrfs_release_path(path);
3026
3027 if (stop_loop)
3028 break;
3029
3030 logic_start += map->stripe_len;
3031 }
3032out:
3033 if (ret < 0)
3034 scrub_parity_mark_sectors_error(sparity, logic_start,
3035 logic_end - logic_start);
3036 scrub_parity_put(sparity);
3037 scrub_submit(sctx);
3038 mutex_lock(&sctx->wr_lock);
3039 scrub_wr_submit(sctx);
3040 mutex_unlock(&sctx->wr_lock);
3041
3042 btrfs_release_path(path);
3043 return ret < 0 ? ret : 0;
3044}
3045
3046static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3047 struct map_lookup *map,
3048 struct btrfs_device *scrub_dev,
3049 int num, u64 base, u64 length)
3050{
3051 struct btrfs_path *path, *ppath;
3052 struct btrfs_fs_info *fs_info = sctx->fs_info;
3053 struct btrfs_root *root = fs_info->extent_root;
3054 struct btrfs_root *csum_root = fs_info->csum_root;
3055 struct btrfs_extent_item *extent;
3056 struct blk_plug plug;
3057 u64 flags;
3058 int ret;
3059 int slot;
3060 u64 nstripes;
3061 struct extent_buffer *l;
3062 u64 physical;
3063 u64 logical;
3064 u64 logic_end;
3065 u64 physical_end;
3066 u64 generation;
3067 int mirror_num;
3068 struct reada_control *reada1;
3069 struct reada_control *reada2;
3070 struct btrfs_key key;
3071 struct btrfs_key key_end;
3072 u64 increment = map->stripe_len;
3073 u64 offset;
3074 u64 extent_logical;
3075 u64 extent_physical;
3076 u64 extent_len;
3077 u64 stripe_logical;
3078 u64 stripe_end;
3079 struct btrfs_device *extent_dev;
3080 int extent_mirror_num;
3081 int stop_loop = 0;
3082
3083 physical = map->stripes[num].physical;
3084 offset = 0;
3085 nstripes = div64_u64(length, map->stripe_len);
3086 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3087 offset = map->stripe_len * num;
3088 increment = map->stripe_len * map->num_stripes;
3089 mirror_num = 1;
3090 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3091 int factor = map->num_stripes / map->sub_stripes;
3092 offset = map->stripe_len * (num / map->sub_stripes);
3093 increment = map->stripe_len * factor;
3094 mirror_num = num % map->sub_stripes + 1;
3095 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
3096 increment = map->stripe_len;
3097 mirror_num = num % map->num_stripes + 1;
3098 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3099 increment = map->stripe_len;
3100 mirror_num = num % map->num_stripes + 1;
3101 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3102 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3103 increment = map->stripe_len * nr_data_stripes(map);
3104 mirror_num = 1;
3105 } else {
3106 increment = map->stripe_len;
3107 mirror_num = 1;
3108 }
3109
3110 path = btrfs_alloc_path();
3111 if (!path)
3112 return -ENOMEM;
3113
3114 ppath = btrfs_alloc_path();
3115 if (!ppath) {
3116 btrfs_free_path(path);
3117 return -ENOMEM;
3118 }
3119
3120 /*
3121 * work on commit root. The related disk blocks are static as
3122 * long as COW is applied. This means, it is save to rewrite
3123 * them to repair disk errors without any race conditions
3124 */
3125 path->search_commit_root = 1;
3126 path->skip_locking = 1;
3127
3128 ppath->search_commit_root = 1;
3129 ppath->skip_locking = 1;
3130 /*
3131 * trigger the readahead for extent tree csum tree and wait for
3132 * completion. During readahead, the scrub is officially paused
3133 * to not hold off transaction commits
3134 */
3135 logical = base + offset;
3136 physical_end = physical + nstripes * map->stripe_len;
3137 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3138 get_raid56_logic_offset(physical_end, num,
3139 map, &logic_end, NULL);
3140 logic_end += base;
3141 } else {
3142 logic_end = logical + increment * nstripes;
3143 }
3144 wait_event(sctx->list_wait,
3145 atomic_read(&sctx->bios_in_flight) == 0);
3146 scrub_blocked_if_needed(fs_info);
3147
3148 /* FIXME it might be better to start readahead at commit root */
3149 key.objectid = logical;
3150 key.type = BTRFS_EXTENT_ITEM_KEY;
3151 key.offset = (u64)0;
3152 key_end.objectid = logic_end;
3153 key_end.type = BTRFS_METADATA_ITEM_KEY;
3154 key_end.offset = (u64)-1;
3155 reada1 = btrfs_reada_add(root, &key, &key_end);
3156
3157 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3158 key.type = BTRFS_EXTENT_CSUM_KEY;
3159 key.offset = logical;
3160 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3161 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3162 key_end.offset = logic_end;
3163 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3164
3165 if (!IS_ERR(reada1))
3166 btrfs_reada_wait(reada1);
3167 if (!IS_ERR(reada2))
3168 btrfs_reada_wait(reada2);
3169
3170
3171 /*
3172 * collect all data csums for the stripe to avoid seeking during
3173 * the scrub. This might currently (crc32) end up to be about 1MB
3174 */
3175 blk_start_plug(&plug);
3176
3177 /*
3178 * now find all extents for each stripe and scrub them
3179 */
3180 ret = 0;
3181 while (physical < physical_end) {
3182 /*
3183 * canceled?
3184 */
3185 if (atomic_read(&fs_info->scrub_cancel_req) ||
3186 atomic_read(&sctx->cancel_req)) {
3187 ret = -ECANCELED;
3188 goto out;
3189 }
3190 /*
3191 * check to see if we have to pause
3192 */
3193 if (atomic_read(&fs_info->scrub_pause_req)) {
3194 /* push queued extents */
3195 sctx->flush_all_writes = true;
3196 scrub_submit(sctx);
3197 mutex_lock(&sctx->wr_lock);
3198 scrub_wr_submit(sctx);
3199 mutex_unlock(&sctx->wr_lock);
3200 wait_event(sctx->list_wait,
3201 atomic_read(&sctx->bios_in_flight) == 0);
3202 sctx->flush_all_writes = false;
3203 scrub_blocked_if_needed(fs_info);
3204 }
3205
3206 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3207 ret = get_raid56_logic_offset(physical, num, map,
3208 &logical,
3209 &stripe_logical);
3210 logical += base;
3211 if (ret) {
3212 /* it is parity strip */
3213 stripe_logical += base;
3214 stripe_end = stripe_logical + increment;
3215 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3216 ppath, stripe_logical,
3217 stripe_end);
3218 if (ret)
3219 goto out;
3220 goto skip;
3221 }
3222 }
3223
3224 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3225 key.type = BTRFS_METADATA_ITEM_KEY;
3226 else
3227 key.type = BTRFS_EXTENT_ITEM_KEY;
3228 key.objectid = logical;
3229 key.offset = (u64)-1;
3230
3231 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3232 if (ret < 0)
3233 goto out;
3234
3235 if (ret > 0) {
3236 ret = btrfs_previous_extent_item(root, path, 0);
3237 if (ret < 0)
3238 goto out;
3239 if (ret > 0) {
3240 /* there's no smaller item, so stick with the
3241 * larger one */
3242 btrfs_release_path(path);
3243 ret = btrfs_search_slot(NULL, root, &key,
3244 path, 0, 0);
3245 if (ret < 0)
3246 goto out;
3247 }
3248 }
3249
3250 stop_loop = 0;
3251 while (1) {
3252 u64 bytes;
3253
3254 l = path->nodes[0];
3255 slot = path->slots[0];
3256 if (slot >= btrfs_header_nritems(l)) {
3257 ret = btrfs_next_leaf(root, path);
3258 if (ret == 0)
3259 continue;
3260 if (ret < 0)
3261 goto out;
3262
3263 stop_loop = 1;
3264 break;
3265 }
3266 btrfs_item_key_to_cpu(l, &key, slot);
3267
3268 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3269 key.type != BTRFS_METADATA_ITEM_KEY)
3270 goto next;
3271
3272 if (key.type == BTRFS_METADATA_ITEM_KEY)
3273 bytes = fs_info->nodesize;
3274 else
3275 bytes = key.offset;
3276
3277 if (key.objectid + bytes <= logical)
3278 goto next;
3279
3280 if (key.objectid >= logical + map->stripe_len) {
3281 /* out of this device extent */
3282 if (key.objectid >= logic_end)
3283 stop_loop = 1;
3284 break;
3285 }
3286
3287 extent = btrfs_item_ptr(l, slot,
3288 struct btrfs_extent_item);
3289 flags = btrfs_extent_flags(l, extent);
3290 generation = btrfs_extent_generation(l, extent);
3291
3292 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3293 (key.objectid < logical ||
3294 key.objectid + bytes >
3295 logical + map->stripe_len)) {
3296 btrfs_err(fs_info,
3297 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3298 key.objectid, logical);
3299 spin_lock(&sctx->stat_lock);
3300 sctx->stat.uncorrectable_errors++;
3301 spin_unlock(&sctx->stat_lock);
3302 goto next;
3303 }
3304
3305again:
3306 extent_logical = key.objectid;
3307 extent_len = bytes;
3308
3309 /*
3310 * trim extent to this stripe
3311 */
3312 if (extent_logical < logical) {
3313 extent_len -= logical - extent_logical;
3314 extent_logical = logical;
3315 }
3316 if (extent_logical + extent_len >
3317 logical + map->stripe_len) {
3318 extent_len = logical + map->stripe_len -
3319 extent_logical;
3320 }
3321
3322 extent_physical = extent_logical - logical + physical;
3323 extent_dev = scrub_dev;
3324 extent_mirror_num = mirror_num;
3325 if (sctx->is_dev_replace)
3326 scrub_remap_extent(fs_info, extent_logical,
3327 extent_len, &extent_physical,
3328 &extent_dev,
3329 &extent_mirror_num);
3330
3331 ret = btrfs_lookup_csums_range(csum_root,
3332 extent_logical,
3333 extent_logical +
3334 extent_len - 1,
3335 &sctx->csum_list, 1);
3336 if (ret)
3337 goto out;
3338
3339 ret = scrub_extent(sctx, map, extent_logical, extent_len,
3340 extent_physical, extent_dev, flags,
3341 generation, extent_mirror_num,
3342 extent_logical - logical + physical);
3343
3344 scrub_free_csums(sctx);
3345
3346 if (ret)
3347 goto out;
3348
3349 if (extent_logical + extent_len <
3350 key.objectid + bytes) {
3351 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3352 /*
3353 * loop until we find next data stripe
3354 * or we have finished all stripes.
3355 */
3356loop:
3357 physical += map->stripe_len;
3358 ret = get_raid56_logic_offset(physical,
3359 num, map, &logical,
3360 &stripe_logical);
3361 logical += base;
3362
3363 if (ret && physical < physical_end) {
3364 stripe_logical += base;
3365 stripe_end = stripe_logical +
3366 increment;
3367 ret = scrub_raid56_parity(sctx,
3368 map, scrub_dev, ppath,
3369 stripe_logical,
3370 stripe_end);
3371 if (ret)
3372 goto out;
3373 goto loop;
3374 }
3375 } else {
3376 physical += map->stripe_len;
3377 logical += increment;
3378 }
3379 if (logical < key.objectid + bytes) {
3380 cond_resched();
3381 goto again;
3382 }
3383
3384 if (physical >= physical_end) {
3385 stop_loop = 1;
3386 break;
3387 }
3388 }
3389next:
3390 path->slots[0]++;
3391 }
3392 btrfs_release_path(path);
3393skip:
3394 logical += increment;
3395 physical += map->stripe_len;
3396 spin_lock(&sctx->stat_lock);
3397 if (stop_loop)
3398 sctx->stat.last_physical = map->stripes[num].physical +
3399 length;
3400 else
3401 sctx->stat.last_physical = physical;
3402 spin_unlock(&sctx->stat_lock);
3403 if (stop_loop)
3404 break;
3405 }
3406out:
3407 /* push queued extents */
3408 scrub_submit(sctx);
3409 mutex_lock(&sctx->wr_lock);
3410 scrub_wr_submit(sctx);
3411 mutex_unlock(&sctx->wr_lock);
3412
3413 blk_finish_plug(&plug);
3414 btrfs_free_path(path);
3415 btrfs_free_path(ppath);
3416 return ret < 0 ? ret : 0;
3417}
3418
3419static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3420 struct btrfs_device *scrub_dev,
3421 u64 chunk_offset, u64 length,
3422 u64 dev_offset,
3423 struct btrfs_block_group_cache *cache)
3424{
3425 struct btrfs_fs_info *fs_info = sctx->fs_info;
3426 struct extent_map_tree *map_tree = &fs_info->mapping_tree;
3427 struct map_lookup *map;
3428 struct extent_map *em;
3429 int i;
3430 int ret = 0;
3431
3432 read_lock(&map_tree->lock);
3433 em = lookup_extent_mapping(map_tree, chunk_offset, 1);
3434 read_unlock(&map_tree->lock);
3435
3436 if (!em) {
3437 /*
3438 * Might have been an unused block group deleted by the cleaner
3439 * kthread or relocation.
3440 */
3441 spin_lock(&cache->lock);
3442 if (!cache->removed)
3443 ret = -EINVAL;
3444 spin_unlock(&cache->lock);
3445
3446 return ret;
3447 }
3448
3449 map = em->map_lookup;
3450 if (em->start != chunk_offset)
3451 goto out;
3452
3453 if (em->len < length)
3454 goto out;
3455
3456 for (i = 0; i < map->num_stripes; ++i) {
3457 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3458 map->stripes[i].physical == dev_offset) {
3459 ret = scrub_stripe(sctx, map, scrub_dev, i,
3460 chunk_offset, length);
3461 if (ret)
3462 goto out;
3463 }
3464 }
3465out:
3466 free_extent_map(em);
3467
3468 return ret;
3469}
3470
3471static noinline_for_stack
3472int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3473 struct btrfs_device *scrub_dev, u64 start, u64 end)
3474{
3475 struct btrfs_dev_extent *dev_extent = NULL;
3476 struct btrfs_path *path;
3477 struct btrfs_fs_info *fs_info = sctx->fs_info;
3478 struct btrfs_root *root = fs_info->dev_root;
3479 u64 length;
3480 u64 chunk_offset;
3481 int ret = 0;
3482 int ro_set;
3483 int slot;
3484 struct extent_buffer *l;
3485 struct btrfs_key key;
3486 struct btrfs_key found_key;
3487 struct btrfs_block_group_cache *cache;
3488 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3489
3490 path = btrfs_alloc_path();
3491 if (!path)
3492 return -ENOMEM;
3493
3494 path->reada = READA_FORWARD;
3495 path->search_commit_root = 1;
3496 path->skip_locking = 1;
3497
3498 key.objectid = scrub_dev->devid;
3499 key.offset = 0ull;
3500 key.type = BTRFS_DEV_EXTENT_KEY;
3501
3502 while (1) {
3503 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3504 if (ret < 0)
3505 break;
3506 if (ret > 0) {
3507 if (path->slots[0] >=
3508 btrfs_header_nritems(path->nodes[0])) {
3509 ret = btrfs_next_leaf(root, path);
3510 if (ret < 0)
3511 break;
3512 if (ret > 0) {
3513 ret = 0;
3514 break;
3515 }
3516 } else {
3517 ret = 0;
3518 }
3519 }
3520
3521 l = path->nodes[0];
3522 slot = path->slots[0];
3523
3524 btrfs_item_key_to_cpu(l, &found_key, slot);
3525
3526 if (found_key.objectid != scrub_dev->devid)
3527 break;
3528
3529 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3530 break;
3531
3532 if (found_key.offset >= end)
3533 break;
3534
3535 if (found_key.offset < key.offset)
3536 break;
3537
3538 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3539 length = btrfs_dev_extent_length(l, dev_extent);
3540
3541 if (found_key.offset + length <= start)
3542 goto skip;
3543
3544 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3545
3546 /*
3547 * get a reference on the corresponding block group to prevent
3548 * the chunk from going away while we scrub it
3549 */
3550 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3551
3552 /* some chunks are removed but not committed to disk yet,
3553 * continue scrubbing */
3554 if (!cache)
3555 goto skip;
3556
3557 /*
3558 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3559 * to avoid deadlock caused by:
3560 * btrfs_inc_block_group_ro()
3561 * -> btrfs_wait_for_commit()
3562 * -> btrfs_commit_transaction()
3563 * -> btrfs_scrub_pause()
3564 */
3565 scrub_pause_on(fs_info);
3566 ret = btrfs_inc_block_group_ro(cache);
3567 if (!ret && sctx->is_dev_replace) {
3568 /*
3569 * If we are doing a device replace wait for any tasks
3570 * that started delalloc right before we set the block
3571 * group to RO mode, as they might have just allocated
3572 * an extent from it or decided they could do a nocow
3573 * write. And if any such tasks did that, wait for their
3574 * ordered extents to complete and then commit the
3575 * current transaction, so that we can later see the new
3576 * extent items in the extent tree - the ordered extents
3577 * create delayed data references (for cow writes) when
3578 * they complete, which will be run and insert the
3579 * corresponding extent items into the extent tree when
3580 * we commit the transaction they used when running
3581 * inode.c:btrfs_finish_ordered_io(). We later use
3582 * the commit root of the extent tree to find extents
3583 * to copy from the srcdev into the tgtdev, and we don't
3584 * want to miss any new extents.
3585 */
3586 btrfs_wait_block_group_reservations(cache);
3587 btrfs_wait_nocow_writers(cache);
3588 ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
3589 cache->key.objectid,
3590 cache->key.offset);
3591 if (ret > 0) {
3592 struct btrfs_trans_handle *trans;
3593
3594 trans = btrfs_join_transaction(root);
3595 if (IS_ERR(trans))
3596 ret = PTR_ERR(trans);
3597 else
3598 ret = btrfs_commit_transaction(trans);
3599 if (ret) {
3600 scrub_pause_off(fs_info);
3601 btrfs_put_block_group(cache);
3602 break;
3603 }
3604 }
3605 }
3606 scrub_pause_off(fs_info);
3607
3608 if (ret == 0) {
3609 ro_set = 1;
3610 } else if (ret == -ENOSPC) {
3611 /*
3612 * btrfs_inc_block_group_ro return -ENOSPC when it
3613 * failed in creating new chunk for metadata.
3614 * It is not a problem for scrub/replace, because
3615 * metadata are always cowed, and our scrub paused
3616 * commit_transactions.
3617 */
3618 ro_set = 0;
3619 } else {
3620 btrfs_warn(fs_info,
3621 "failed setting block group ro: %d", ret);
3622 btrfs_put_block_group(cache);
3623 break;
3624 }
3625
3626 down_write(&fs_info->dev_replace.rwsem);
3627 dev_replace->cursor_right = found_key.offset + length;
3628 dev_replace->cursor_left = found_key.offset;
3629 dev_replace->item_needs_writeback = 1;
3630 up_write(&dev_replace->rwsem);
3631
3632 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3633 found_key.offset, cache);
3634
3635 /*
3636 * flush, submit all pending read and write bios, afterwards
3637 * wait for them.
3638 * Note that in the dev replace case, a read request causes
3639 * write requests that are submitted in the read completion
3640 * worker. Therefore in the current situation, it is required
3641 * that all write requests are flushed, so that all read and
3642 * write requests are really completed when bios_in_flight
3643 * changes to 0.
3644 */
3645 sctx->flush_all_writes = true;
3646 scrub_submit(sctx);
3647 mutex_lock(&sctx->wr_lock);
3648 scrub_wr_submit(sctx);
3649 mutex_unlock(&sctx->wr_lock);
3650
3651 wait_event(sctx->list_wait,
3652 atomic_read(&sctx->bios_in_flight) == 0);
3653
3654 scrub_pause_on(fs_info);
3655
3656 /*
3657 * must be called before we decrease @scrub_paused.
3658 * make sure we don't block transaction commit while
3659 * we are waiting pending workers finished.
3660 */
3661 wait_event(sctx->list_wait,
3662 atomic_read(&sctx->workers_pending) == 0);
3663 sctx->flush_all_writes = false;
3664
3665 scrub_pause_off(fs_info);
3666
3667 down_write(&fs_info->dev_replace.rwsem);
3668 dev_replace->cursor_left = dev_replace->cursor_right;
3669 dev_replace->item_needs_writeback = 1;
3670 up_write(&fs_info->dev_replace.rwsem);
3671
3672 if (ro_set)
3673 btrfs_dec_block_group_ro(cache);
3674
3675 /*
3676 * We might have prevented the cleaner kthread from deleting
3677 * this block group if it was already unused because we raced
3678 * and set it to RO mode first. So add it back to the unused
3679 * list, otherwise it might not ever be deleted unless a manual
3680 * balance is triggered or it becomes used and unused again.
3681 */
3682 spin_lock(&cache->lock);
3683 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3684 btrfs_block_group_used(&cache->item) == 0) {
3685 spin_unlock(&cache->lock);
3686 btrfs_mark_bg_unused(cache);
3687 } else {
3688 spin_unlock(&cache->lock);
3689 }
3690
3691 btrfs_put_block_group(cache);
3692 if (ret)
3693 break;
3694 if (sctx->is_dev_replace &&
3695 atomic64_read(&dev_replace->num_write_errors) > 0) {
3696 ret = -EIO;
3697 break;
3698 }
3699 if (sctx->stat.malloc_errors > 0) {
3700 ret = -ENOMEM;
3701 break;
3702 }
3703skip:
3704 key.offset = found_key.offset + length;
3705 btrfs_release_path(path);
3706 }
3707
3708 btrfs_free_path(path);
3709
3710 return ret;
3711}
3712
3713static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3714 struct btrfs_device *scrub_dev)
3715{
3716 int i;
3717 u64 bytenr;
3718 u64 gen;
3719 int ret;
3720 struct btrfs_fs_info *fs_info = sctx->fs_info;
3721
3722 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3723 return -EIO;
3724
3725 /* Seed devices of a new filesystem has their own generation. */
3726 if (scrub_dev->fs_devices != fs_info->fs_devices)
3727 gen = scrub_dev->generation;
3728 else
3729 gen = fs_info->last_trans_committed;
3730
3731 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3732 bytenr = btrfs_sb_offset(i);
3733 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3734 scrub_dev->commit_total_bytes)
3735 break;
3736
3737 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3738 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3739 NULL, 1, bytenr);
3740 if (ret)
3741 return ret;
3742 }
3743 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3744
3745 return 0;
3746}
3747
3748/*
3749 * get a reference count on fs_info->scrub_workers. start worker if necessary
3750 */
3751static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3752 int is_dev_replace)
3753{
3754 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3755 int max_active = fs_info->thread_pool_size;
3756
3757 lockdep_assert_held(&fs_info->scrub_lock);
3758
3759 if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
3760 ASSERT(fs_info->scrub_workers == NULL);
3761 fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
3762 flags, is_dev_replace ? 1 : max_active, 4);
3763 if (!fs_info->scrub_workers)
3764 goto fail_scrub_workers;
3765
3766 ASSERT(fs_info->scrub_wr_completion_workers == NULL);
3767 fs_info->scrub_wr_completion_workers =
3768 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3769 max_active, 2);
3770 if (!fs_info->scrub_wr_completion_workers)
3771 goto fail_scrub_wr_completion_workers;
3772
3773 ASSERT(fs_info->scrub_parity_workers == NULL);
3774 fs_info->scrub_parity_workers =
3775 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3776 max_active, 2);
3777 if (!fs_info->scrub_parity_workers)
3778 goto fail_scrub_parity_workers;
3779
3780 refcount_set(&fs_info->scrub_workers_refcnt, 1);
3781 } else {
3782 refcount_inc(&fs_info->scrub_workers_refcnt);
3783 }
3784 return 0;
3785
3786fail_scrub_parity_workers:
3787 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3788fail_scrub_wr_completion_workers:
3789 btrfs_destroy_workqueue(fs_info->scrub_workers);
3790fail_scrub_workers:
3791 return -ENOMEM;
3792}
3793
3794int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3795 u64 end, struct btrfs_scrub_progress *progress,
3796 int readonly, int is_dev_replace)
3797{
3798 struct scrub_ctx *sctx;
3799 int ret;
3800 struct btrfs_device *dev;
3801 unsigned int nofs_flag;
3802 struct btrfs_workqueue *scrub_workers = NULL;
3803 struct btrfs_workqueue *scrub_wr_comp = NULL;
3804 struct btrfs_workqueue *scrub_parity = NULL;
3805
3806 if (btrfs_fs_closing(fs_info))
3807 return -EAGAIN;
3808
3809 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3810 /*
3811 * in this case scrub is unable to calculate the checksum
3812 * the way scrub is implemented. Do not handle this
3813 * situation at all because it won't ever happen.
3814 */
3815 btrfs_err(fs_info,
3816 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3817 fs_info->nodesize,
3818 BTRFS_STRIPE_LEN);
3819 return -EINVAL;
3820 }
3821
3822 if (fs_info->sectorsize != PAGE_SIZE) {
3823 /* not supported for data w/o checksums */
3824 btrfs_err_rl(fs_info,
3825 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3826 fs_info->sectorsize, PAGE_SIZE);
3827 return -EINVAL;
3828 }
3829
3830 if (fs_info->nodesize >
3831 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3832 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3833 /*
3834 * would exhaust the array bounds of pagev member in
3835 * struct scrub_block
3836 */
3837 btrfs_err(fs_info,
3838 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3839 fs_info->nodesize,
3840 SCRUB_MAX_PAGES_PER_BLOCK,
3841 fs_info->sectorsize,
3842 SCRUB_MAX_PAGES_PER_BLOCK);
3843 return -EINVAL;
3844 }
3845
3846 /* Allocate outside of device_list_mutex */
3847 sctx = scrub_setup_ctx(fs_info, is_dev_replace);
3848 if (IS_ERR(sctx))
3849 return PTR_ERR(sctx);
3850
3851 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3852 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
3853 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
3854 !is_dev_replace)) {
3855 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3856 ret = -ENODEV;
3857 goto out_free_ctx;
3858 }
3859
3860 if (!is_dev_replace && !readonly &&
3861 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
3862 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3863 btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
3864 rcu_str_deref(dev->name));
3865 ret = -EROFS;
3866 goto out_free_ctx;
3867 }
3868
3869 mutex_lock(&fs_info->scrub_lock);
3870 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3871 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
3872 mutex_unlock(&fs_info->scrub_lock);
3873 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3874 ret = -EIO;
3875 goto out_free_ctx;
3876 }
3877
3878 down_read(&fs_info->dev_replace.rwsem);
3879 if (dev->scrub_ctx ||
3880 (!is_dev_replace &&
3881 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3882 up_read(&fs_info->dev_replace.rwsem);
3883 mutex_unlock(&fs_info->scrub_lock);
3884 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3885 ret = -EINPROGRESS;
3886 goto out_free_ctx;
3887 }
3888 up_read(&fs_info->dev_replace.rwsem);
3889
3890 ret = scrub_workers_get(fs_info, is_dev_replace);
3891 if (ret) {
3892 mutex_unlock(&fs_info->scrub_lock);
3893 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3894 goto out_free_ctx;
3895 }
3896
3897 sctx->readonly = readonly;
3898 dev->scrub_ctx = sctx;
3899 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3900
3901 /*
3902 * checking @scrub_pause_req here, we can avoid
3903 * race between committing transaction and scrubbing.
3904 */
3905 __scrub_blocked_if_needed(fs_info);
3906 atomic_inc(&fs_info->scrubs_running);
3907 mutex_unlock(&fs_info->scrub_lock);
3908
3909 /*
3910 * In order to avoid deadlock with reclaim when there is a transaction
3911 * trying to pause scrub, make sure we use GFP_NOFS for all the
3912 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
3913 * invoked by our callees. The pausing request is done when the
3914 * transaction commit starts, and it blocks the transaction until scrub
3915 * is paused (done at specific points at scrub_stripe() or right above
3916 * before incrementing fs_info->scrubs_running).
3917 */
3918 nofs_flag = memalloc_nofs_save();
3919 if (!is_dev_replace) {
3920 btrfs_info(fs_info, "scrub: started on devid %llu", devid);
3921 /*
3922 * by holding device list mutex, we can
3923 * kick off writing super in log tree sync.
3924 */
3925 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3926 ret = scrub_supers(sctx, dev);
3927 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3928 }
3929
3930 if (!ret)
3931 ret = scrub_enumerate_chunks(sctx, dev, start, end);
3932 memalloc_nofs_restore(nofs_flag);
3933
3934 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3935 atomic_dec(&fs_info->scrubs_running);
3936 wake_up(&fs_info->scrub_pause_wait);
3937
3938 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3939
3940 if (progress)
3941 memcpy(progress, &sctx->stat, sizeof(*progress));
3942
3943 if (!is_dev_replace)
3944 btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
3945 ret ? "not finished" : "finished", devid, ret);
3946
3947 mutex_lock(&fs_info->scrub_lock);
3948 dev->scrub_ctx = NULL;
3949 if (refcount_dec_and_test(&fs_info->scrub_workers_refcnt)) {
3950 scrub_workers = fs_info->scrub_workers;
3951 scrub_wr_comp = fs_info->scrub_wr_completion_workers;
3952 scrub_parity = fs_info->scrub_parity_workers;
3953
3954 fs_info->scrub_workers = NULL;
3955 fs_info->scrub_wr_completion_workers = NULL;
3956 fs_info->scrub_parity_workers = NULL;
3957 }
3958 mutex_unlock(&fs_info->scrub_lock);
3959
3960 btrfs_destroy_workqueue(scrub_workers);
3961 btrfs_destroy_workqueue(scrub_wr_comp);
3962 btrfs_destroy_workqueue(scrub_parity);
3963 scrub_put_ctx(sctx);
3964
3965 return ret;
3966
3967out_free_ctx:
3968 scrub_free_ctx(sctx);
3969
3970 return ret;
3971}
3972
3973void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3974{
3975 mutex_lock(&fs_info->scrub_lock);
3976 atomic_inc(&fs_info->scrub_pause_req);
3977 while (atomic_read(&fs_info->scrubs_paused) !=
3978 atomic_read(&fs_info->scrubs_running)) {
3979 mutex_unlock(&fs_info->scrub_lock);
3980 wait_event(fs_info->scrub_pause_wait,
3981 atomic_read(&fs_info->scrubs_paused) ==
3982 atomic_read(&fs_info->scrubs_running));
3983 mutex_lock(&fs_info->scrub_lock);
3984 }
3985 mutex_unlock(&fs_info->scrub_lock);
3986}
3987
3988void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3989{
3990 atomic_dec(&fs_info->scrub_pause_req);
3991 wake_up(&fs_info->scrub_pause_wait);
3992}
3993
3994int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3995{
3996 mutex_lock(&fs_info->scrub_lock);
3997 if (!atomic_read(&fs_info->scrubs_running)) {
3998 mutex_unlock(&fs_info->scrub_lock);
3999 return -ENOTCONN;
4000 }
4001
4002 atomic_inc(&fs_info->scrub_cancel_req);
4003 while (atomic_read(&fs_info->scrubs_running)) {
4004 mutex_unlock(&fs_info->scrub_lock);
4005 wait_event(fs_info->scrub_pause_wait,
4006 atomic_read(&fs_info->scrubs_running) == 0);
4007 mutex_lock(&fs_info->scrub_lock);
4008 }
4009 atomic_dec(&fs_info->scrub_cancel_req);
4010 mutex_unlock(&fs_info->scrub_lock);
4011
4012 return 0;
4013}
4014
4015int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
4016{
4017 struct btrfs_fs_info *fs_info = dev->fs_info;
4018 struct scrub_ctx *sctx;
4019
4020 mutex_lock(&fs_info->scrub_lock);
4021 sctx = dev->scrub_ctx;
4022 if (!sctx) {
4023 mutex_unlock(&fs_info->scrub_lock);
4024 return -ENOTCONN;
4025 }
4026 atomic_inc(&sctx->cancel_req);
4027 while (dev->scrub_ctx) {
4028 mutex_unlock(&fs_info->scrub_lock);
4029 wait_event(fs_info->scrub_pause_wait,
4030 dev->scrub_ctx == NULL);
4031 mutex_lock(&fs_info->scrub_lock);
4032 }
4033 mutex_unlock(&fs_info->scrub_lock);
4034
4035 return 0;
4036}
4037
4038int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4039 struct btrfs_scrub_progress *progress)
4040{
4041 struct btrfs_device *dev;
4042 struct scrub_ctx *sctx = NULL;
4043
4044 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4045 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
4046 if (dev)
4047 sctx = dev->scrub_ctx;
4048 if (sctx)
4049 memcpy(progress, &sctx->stat, sizeof(*progress));
4050 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4051
4052 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4053}
4054
4055static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4056 u64 extent_logical, u64 extent_len,
4057 u64 *extent_physical,
4058 struct btrfs_device **extent_dev,
4059 int *extent_mirror_num)
4060{
4061 u64 mapped_length;
4062 struct btrfs_bio *bbio = NULL;
4063 int ret;
4064
4065 mapped_length = extent_len;
4066 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4067 &mapped_length, &bbio, 0);
4068 if (ret || !bbio || mapped_length < extent_len ||
4069 !bbio->stripes[0].dev->bdev) {
4070 btrfs_put_bbio(bbio);
4071 return;
4072 }
4073
4074 *extent_physical = bbio->stripes[0].physical;
4075 *extent_mirror_num = bbio->mirror_num;
4076 *extent_dev = bbio->stripes[0].dev;
4077 btrfs_put_bbio(bbio);
4078}
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}