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fanotify: merge duplicate events on parent and child
[linux/fpc-iii.git] / fs / btrfs / scrub.c
blob61b37c56a7fb934b25aface21c7736ae6757da78
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 "discard.h"
12 #include "volumes.h"
13 #include "disk-io.h"
14 #include "ordered-data.h"
15 #include "transaction.h"
16 #include "backref.h"
17 #include "extent_io.h"
18 #include "dev-replace.h"
19 #include "check-integrity.h"
20 #include "rcu-string.h"
21 #include "raid56.h"
22 #include "block-group.h"
23
24 /*
25 * This is only the first step towards a full-features scrub. It reads all
26 * extent and super block and verifies the checksums. In case a bad checksum
27 * is found or the extent cannot be read, good data will be written back if
28 * any can be found.
29 *
30 * Future enhancements:
31 * - In case an unrepairable extent is encountered, track which files are
32 * affected and report them
33 * - track and record media errors, throw out bad devices
34 * - add a mode to also read unallocated space
35 */
36
37 struct scrub_block;
38 struct scrub_ctx;
39
40 /*
41 * the following three values only influence the performance.
42 * The last one configures the number of parallel and outstanding I/O
43 * operations. The first two values configure an upper limit for the number
44 * of (dynamically allocated) pages that are added to a bio.
45 */
46 #define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
47 #define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
48 #define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
49
50 /*
51 * the following value times PAGE_SIZE needs to be large enough to match the
52 * largest node/leaf/sector size that shall be supported.
53 * Values larger than BTRFS_STRIPE_LEN are not supported.
54 */
55 #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
56
57 struct scrub_recover {
58 refcount_t refs;
59 struct btrfs_bio *bbio;
60 u64 map_length;
61 };
62
63 struct scrub_page {
64 struct scrub_block *sblock;
65 struct page *page;
66 struct btrfs_device *dev;
67 struct list_head list;
68 u64 flags; /* extent flags */
69 u64 generation;
70 u64 logical;
71 u64 physical;
72 u64 physical_for_dev_replace;
73 atomic_t refs;
74 struct {
75 unsigned int mirror_num:8;
76 unsigned int have_csum:1;
77 unsigned int io_error:1;
78 };
79 u8 csum[BTRFS_CSUM_SIZE];
80
81 struct scrub_recover *recover;
82 };
83
84 struct scrub_bio {
85 int index;
86 struct scrub_ctx *sctx;
87 struct btrfs_device *dev;
88 struct bio *bio;
89 blk_status_t status;
90 u64 logical;
91 u64 physical;
92 #if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
93 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
94 #else
95 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
96 #endif
97 int page_count;
98 int next_free;
99 struct btrfs_work work;
100 };
101
102 struct scrub_block {
103 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
104 int page_count;
105 atomic_t outstanding_pages;
106 refcount_t refs; /* free mem on transition to zero */
107 struct scrub_ctx *sctx;
108 struct scrub_parity *sparity;
109 struct {
110 unsigned int header_error:1;
111 unsigned int checksum_error:1;
112 unsigned int no_io_error_seen:1;
113 unsigned int generation_error:1; /* also sets header_error */
114
115 /* The following is for the data used to check parity */
116 /* It is for the data with checksum */
117 unsigned int data_corrected:1;
118 };
119 struct btrfs_work work;
120 };
121
122 /* Used for the chunks with parity stripe such RAID5/6 */
123 struct scrub_parity {
124 struct scrub_ctx *sctx;
125
126 struct btrfs_device *scrub_dev;
127
128 u64 logic_start;
129
130 u64 logic_end;
131
132 int nsectors;
133
134 u64 stripe_len;
135
136 refcount_t refs;
137
138 struct list_head spages;
139
140 /* Work of parity check and repair */
141 struct btrfs_work work;
142
143 /* Mark the parity blocks which have data */
144 unsigned long *dbitmap;
145
146 /*
147 * Mark the parity blocks which have data, but errors happen when
148 * read data or check data
149 */
150 unsigned long *ebitmap;
151
152 unsigned long bitmap[0];
153 };
154
155 struct scrub_ctx {
156 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
157 struct btrfs_fs_info *fs_info;
158 int first_free;
159 int curr;
160 atomic_t bios_in_flight;
161 atomic_t workers_pending;
162 spinlock_t list_lock;
163 wait_queue_head_t list_wait;
164 u16 csum_size;
165 struct list_head csum_list;
166 atomic_t cancel_req;
167 int readonly;
168 int pages_per_rd_bio;
169
170 int is_dev_replace;
171
172 struct scrub_bio *wr_curr_bio;
173 struct mutex wr_lock;
174 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
175 struct btrfs_device *wr_tgtdev;
176 bool flush_all_writes;
177
178 /*
179 * statistics
180 */
181 struct btrfs_scrub_progress stat;
182 spinlock_t stat_lock;
183
184 /*
185 * Use a ref counter to avoid use-after-free issues. Scrub workers
186 * decrement bios_in_flight and workers_pending and then do a wakeup
187 * on the list_wait wait queue. We must ensure the main scrub task
188 * doesn't free the scrub context before or while the workers are
189 * doing the wakeup() call.
190 */
191 refcount_t refs;
192 };
193
194 struct scrub_warning {
195 struct btrfs_path *path;
196 u64 extent_item_size;
197 const char *errstr;
198 u64 physical;
199 u64 logical;
200 struct btrfs_device *dev;
201 };
202
203 struct full_stripe_lock {
204 struct rb_node node;
205 u64 logical;
206 u64 refs;
207 struct mutex mutex;
208 };
209
210 static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
211 static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
212 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
213 static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
214 struct scrub_block *sblocks_for_recheck);
215 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
216 struct scrub_block *sblock,
217 int retry_failed_mirror);
218 static void scrub_recheck_block_checksum(struct scrub_block *sblock);
219 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
220 struct scrub_block *sblock_good);
221 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
222 struct scrub_block *sblock_good,
223 int page_num, int force_write);
224 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
225 static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
226 int page_num);
227 static int scrub_checksum_data(struct scrub_block *sblock);
228 static int scrub_checksum_tree_block(struct scrub_block *sblock);
229 static int scrub_checksum_super(struct scrub_block *sblock);
230 static void scrub_block_get(struct scrub_block *sblock);
231 static void scrub_block_put(struct scrub_block *sblock);
232 static void scrub_page_get(struct scrub_page *spage);
233 static void scrub_page_put(struct scrub_page *spage);
234 static void scrub_parity_get(struct scrub_parity *sparity);
235 static void scrub_parity_put(struct scrub_parity *sparity);
236 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
237 struct scrub_page *spage);
238 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
239 u64 physical, struct btrfs_device *dev, u64 flags,
240 u64 gen, int mirror_num, u8 *csum, int force,
241 u64 physical_for_dev_replace);
242 static void scrub_bio_end_io(struct bio *bio);
243 static void scrub_bio_end_io_worker(struct btrfs_work *work);
244 static void scrub_block_complete(struct scrub_block *sblock);
245 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
246 u64 extent_logical, u64 extent_len,
247 u64 *extent_physical,
248 struct btrfs_device **extent_dev,
249 int *extent_mirror_num);
250 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
251 struct scrub_page *spage);
252 static void scrub_wr_submit(struct scrub_ctx *sctx);
253 static void scrub_wr_bio_end_io(struct bio *bio);
254 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
255 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
256 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
257 static void scrub_put_ctx(struct scrub_ctx *sctx);
258
259 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
260 {
261 return page->recover &&
262 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
263 }
264
265 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
266 {
267 refcount_inc(&sctx->refs);
268 atomic_inc(&sctx->bios_in_flight);
269 }
270
271 static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
272 {
273 atomic_dec(&sctx->bios_in_flight);
274 wake_up(&sctx->list_wait);
275 scrub_put_ctx(sctx);
276 }
277
278 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
279 {
280 while (atomic_read(&fs_info->scrub_pause_req)) {
281 mutex_unlock(&fs_info->scrub_lock);
282 wait_event(fs_info->scrub_pause_wait,
283 atomic_read(&fs_info->scrub_pause_req) == 0);
284 mutex_lock(&fs_info->scrub_lock);
285 }
286 }
287
288 static void scrub_pause_on(struct btrfs_fs_info *fs_info)
289 {
290 atomic_inc(&fs_info->scrubs_paused);
291 wake_up(&fs_info->scrub_pause_wait);
292 }
293
294 static void scrub_pause_off(struct btrfs_fs_info *fs_info)
295 {
296 mutex_lock(&fs_info->scrub_lock);
297 __scrub_blocked_if_needed(fs_info);
298 atomic_dec(&fs_info->scrubs_paused);
299 mutex_unlock(&fs_info->scrub_lock);
300
301 wake_up(&fs_info->scrub_pause_wait);
302 }
303
304 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
305 {
306 scrub_pause_on(fs_info);
307 scrub_pause_off(fs_info);
308 }
309
310 /*
311 * Insert new full stripe lock into full stripe locks tree
312 *
313 * Return pointer to existing or newly inserted full_stripe_lock structure if
314 * everything works well.
315 * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
316 *
317 * NOTE: caller must hold full_stripe_locks_root->lock before calling this
318 * function
319 */
320 static struct full_stripe_lock *insert_full_stripe_lock(
321 struct btrfs_full_stripe_locks_tree *locks_root,
322 u64 fstripe_logical)
323 {
324 struct rb_node **p;
325 struct rb_node *parent = NULL;
326 struct full_stripe_lock *entry;
327 struct full_stripe_lock *ret;
328
329 lockdep_assert_held(&locks_root->lock);
330
331 p = &locks_root->root.rb_node;
332 while (*p) {
333 parent = *p;
334 entry = rb_entry(parent, struct full_stripe_lock, node);
335 if (fstripe_logical < entry->logical) {
336 p = &(*p)->rb_left;
337 } else if (fstripe_logical > entry->logical) {
338 p = &(*p)->rb_right;
339 } else {
340 entry->refs++;
341 return entry;
342 }
343 }
344
345 /*
346 * Insert new lock.
347 */
348 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
349 if (!ret)
350 return ERR_PTR(-ENOMEM);
351 ret->logical = fstripe_logical;
352 ret->refs = 1;
353 mutex_init(&ret->mutex);
354
355 rb_link_node(&ret->node, parent, p);
356 rb_insert_color(&ret->node, &locks_root->root);
357 return ret;
358 }
359
360 /*
361 * Search for a full stripe lock of a block group
362 *
363 * Return pointer to existing full stripe lock if found
364 * Return NULL if not found
365 */
366 static struct full_stripe_lock *search_full_stripe_lock(
367 struct btrfs_full_stripe_locks_tree *locks_root,
368 u64 fstripe_logical)
369 {
370 struct rb_node *node;
371 struct full_stripe_lock *entry;
372
373 lockdep_assert_held(&locks_root->lock);
374
375 node = locks_root->root.rb_node;
376 while (node) {
377 entry = rb_entry(node, struct full_stripe_lock, node);
378 if (fstripe_logical < entry->logical)
379 node = node->rb_left;
380 else if (fstripe_logical > entry->logical)
381 node = node->rb_right;
382 else
383 return entry;
384 }
385 return NULL;
386 }
387
388 /*
389 * Helper to get full stripe logical from a normal bytenr.
390 *
391 * Caller must ensure @cache is a RAID56 block group.
392 */
393 static u64 get_full_stripe_logical(struct btrfs_block_group *cache, 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->start, cache->full_stripe_len) *
408 cache->full_stripe_len + cache->start;
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 */
423 static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
424 bool *locked_ret)
425 {
426 struct btrfs_block_group *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;
456 out:
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 */
470 static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
471 bool locked)
472 {
473 struct btrfs_block_group *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);
522 out:
523 btrfs_put_block_group(bg_cache);
524 return ret;
525 }
526
527 static 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
538 static 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
569 static void scrub_put_ctx(struct scrub_ctx *sctx)
570 {
571 if (refcount_dec_and_test(&sctx->refs))
572 scrub_free_ctx(sctx);
573 }
574
575 static 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, scrub_bio_end_io_worker, NULL,
602 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
631 nomem:
632 scrub_free_ctx(sctx);
633 return ERR_PTR(-ENOMEM);
634 }
635
636 static 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
717 err:
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
729 static 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
795 out:
796 btrfs_free_path(path);
797 }
798
799 static inline void scrub_get_recover(struct scrub_recover *recover)
800 {
801 refcount_inc(&recover->refs);
802 }
803
804 static 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 */
822 static 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 {
1176 corrected_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 {
1186 did_not_correct_error:
1187 spin_lock(&sctx->stat_lock);
1188 sctx->stat.uncorrectable_errors++;
1189 spin_unlock(&sctx->stat_lock);
1190 btrfs_err_rl_in_rcu(fs_info,
1191 "unable to fixup (regular) error at logical %llu on dev %s",
1192 logical, rcu_str_deref(dev->name));
1193 }
1194
1195 out:
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
1226 static 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
1236 static 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
1266 static 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) {
1336 leave_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
1391 static void scrub_bio_wait_endio(struct bio *bio)
1392 {
1393 complete(bio->bi_private);
1394 }
1395
1396 static 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
1419 static 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;
1451 out:
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 */
1465 static 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
1507 static 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
1517 static 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
1529 static 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
1548 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1549 struct scrub_block *sblock_good,
1550 int page_num, int force_write)
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
1593 static 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
1614 static 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
1630 static 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);
1637 again:
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
1697 static 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
1715 static 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, scrub_wr_bio_end_io_worker, NULL, NULL);
1724 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1725 }
1726
1727 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1728 {
1729 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1730 struct scrub_ctx *sctx = sbio->sctx;
1731 int i;
1732
1733 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1734 if (sbio->status) {
1735 struct btrfs_dev_replace *dev_replace =
1736 &sbio->sctx->fs_info->dev_replace;
1737
1738 for (i = 0; i < sbio->page_count; i++) {
1739 struct scrub_page *spage = sbio->pagev[i];
1740
1741 spage->io_error = 1;
1742 atomic64_inc(&dev_replace->num_write_errors);
1743 }
1744 }
1745
1746 for (i = 0; i < sbio->page_count; i++)
1747 scrub_page_put(sbio->pagev[i]);
1748
1749 bio_put(sbio->bio);
1750 kfree(sbio);
1751 scrub_pending_bio_dec(sctx);
1752 }
1753
1754 static int scrub_checksum(struct scrub_block *sblock)
1755 {
1756 u64 flags;
1757 int ret;
1758
1759 /*
1760 * No need to initialize these stats currently,
1761 * because this function only use return value
1762 * instead of these stats value.
1763 *
1764 * Todo:
1765 * always use stats
1766 */
1767 sblock->header_error = 0;
1768 sblock->generation_error = 0;
1769 sblock->checksum_error = 0;
1770
1771 WARN_ON(sblock->page_count < 1);
1772 flags = sblock->pagev[0]->flags;
1773 ret = 0;
1774 if (flags & BTRFS_EXTENT_FLAG_DATA)
1775 ret = scrub_checksum_data(sblock);
1776 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1777 ret = scrub_checksum_tree_block(sblock);
1778 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1779 (void)scrub_checksum_super(sblock);
1780 else
1781 WARN_ON(1);
1782 if (ret)
1783 scrub_handle_errored_block(sblock);
1784
1785 return ret;
1786 }
1787
1788 static int scrub_checksum_data(struct scrub_block *sblock)
1789 {
1790 struct scrub_ctx *sctx = sblock->sctx;
1791 struct btrfs_fs_info *fs_info = sctx->fs_info;
1792 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1793 u8 csum[BTRFS_CSUM_SIZE];
1794 u8 *on_disk_csum;
1795 struct page *page;
1796 void *buffer;
1797 u64 len;
1798 int index;
1799
1800 BUG_ON(sblock->page_count < 1);
1801 if (!sblock->pagev[0]->have_csum)
1802 return 0;
1803
1804 shash->tfm = fs_info->csum_shash;
1805 crypto_shash_init(shash);
1806
1807 on_disk_csum = sblock->pagev[0]->csum;
1808 page = sblock->pagev[0]->page;
1809 buffer = kmap_atomic(page);
1810
1811 len = sctx->fs_info->sectorsize;
1812 index = 0;
1813 for (;;) {
1814 u64 l = min_t(u64, len, PAGE_SIZE);
1815
1816 crypto_shash_update(shash, buffer, l);
1817 kunmap_atomic(buffer);
1818 len -= l;
1819 if (len == 0)
1820 break;
1821 index++;
1822 BUG_ON(index >= sblock->page_count);
1823 BUG_ON(!sblock->pagev[index]->page);
1824 page = sblock->pagev[index]->page;
1825 buffer = kmap_atomic(page);
1826 }
1827
1828 crypto_shash_final(shash, csum);
1829 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1830 sblock->checksum_error = 1;
1831
1832 return sblock->checksum_error;
1833 }
1834
1835 static int scrub_checksum_tree_block(struct scrub_block *sblock)
1836 {
1837 struct scrub_ctx *sctx = sblock->sctx;
1838 struct btrfs_header *h;
1839 struct btrfs_fs_info *fs_info = sctx->fs_info;
1840 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1841 u8 calculated_csum[BTRFS_CSUM_SIZE];
1842 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1843 struct page *page;
1844 void *mapped_buffer;
1845 u64 mapped_size;
1846 void *p;
1847 u64 len;
1848 int index;
1849
1850 shash->tfm = fs_info->csum_shash;
1851 crypto_shash_init(shash);
1852
1853 BUG_ON(sblock->page_count < 1);
1854 page = sblock->pagev[0]->page;
1855 mapped_buffer = kmap_atomic(page);
1856 h = (struct btrfs_header *)mapped_buffer;
1857 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1858
1859 /*
1860 * we don't use the getter functions here, as we
1861 * a) don't have an extent buffer and
1862 * b) the page is already kmapped
1863 */
1864 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1865 sblock->header_error = 1;
1866
1867 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1868 sblock->header_error = 1;
1869 sblock->generation_error = 1;
1870 }
1871
1872 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1873 sblock->header_error = 1;
1874
1875 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1876 BTRFS_UUID_SIZE))
1877 sblock->header_error = 1;
1878
1879 len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
1880 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1881 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1882 index = 0;
1883 for (;;) {
1884 u64 l = min_t(u64, len, mapped_size);
1885
1886 crypto_shash_update(shash, p, l);
1887 kunmap_atomic(mapped_buffer);
1888 len -= l;
1889 if (len == 0)
1890 break;
1891 index++;
1892 BUG_ON(index >= sblock->page_count);
1893 BUG_ON(!sblock->pagev[index]->page);
1894 page = sblock->pagev[index]->page;
1895 mapped_buffer = kmap_atomic(page);
1896 mapped_size = PAGE_SIZE;
1897 p = mapped_buffer;
1898 }
1899
1900 crypto_shash_final(shash, calculated_csum);
1901 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1902 sblock->checksum_error = 1;
1903
1904 return sblock->header_error || sblock->checksum_error;
1905 }
1906
1907 static int scrub_checksum_super(struct scrub_block *sblock)
1908 {
1909 struct btrfs_super_block *s;
1910 struct scrub_ctx *sctx = sblock->sctx;
1911 struct btrfs_fs_info *fs_info = sctx->fs_info;
1912 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1913 u8 calculated_csum[BTRFS_CSUM_SIZE];
1914 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1915 struct page *page;
1916 void *mapped_buffer;
1917 u64 mapped_size;
1918 void *p;
1919 int fail_gen = 0;
1920 int fail_cor = 0;
1921 u64 len;
1922 int index;
1923
1924 shash->tfm = fs_info->csum_shash;
1925 crypto_shash_init(shash);
1926
1927 BUG_ON(sblock->page_count < 1);
1928 page = sblock->pagev[0]->page;
1929 mapped_buffer = kmap_atomic(page);
1930 s = (struct btrfs_super_block *)mapped_buffer;
1931 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1932
1933 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1934 ++fail_cor;
1935
1936 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1937 ++fail_gen;
1938
1939 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1940 ++fail_cor;
1941
1942 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1943 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1944 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1945 index = 0;
1946 for (;;) {
1947 u64 l = min_t(u64, len, mapped_size);
1948
1949 crypto_shash_update(shash, p, l);
1950 kunmap_atomic(mapped_buffer);
1951 len -= l;
1952 if (len == 0)
1953 break;
1954 index++;
1955 BUG_ON(index >= sblock->page_count);
1956 BUG_ON(!sblock->pagev[index]->page);
1957 page = sblock->pagev[index]->page;
1958 mapped_buffer = kmap_atomic(page);
1959 mapped_size = PAGE_SIZE;
1960 p = mapped_buffer;
1961 }
1962
1963 crypto_shash_final(shash, calculated_csum);
1964 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1965 ++fail_cor;
1966
1967 if (fail_cor + fail_gen) {
1968 /*
1969 * if we find an error in a super block, we just report it.
1970 * They will get written with the next transaction commit
1971 * anyway
1972 */
1973 spin_lock(&sctx->stat_lock);
1974 ++sctx->stat.super_errors;
1975 spin_unlock(&sctx->stat_lock);
1976 if (fail_cor)
1977 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1978 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1979 else
1980 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1981 BTRFS_DEV_STAT_GENERATION_ERRS);
1982 }
1983
1984 return fail_cor + fail_gen;
1985 }
1986
1987 static void scrub_block_get(struct scrub_block *sblock)
1988 {
1989 refcount_inc(&sblock->refs);
1990 }
1991
1992 static void scrub_block_put(struct scrub_block *sblock)
1993 {
1994 if (refcount_dec_and_test(&sblock->refs)) {
1995 int i;
1996
1997 if (sblock->sparity)
1998 scrub_parity_put(sblock->sparity);
1999
2000 for (i = 0; i < sblock->page_count; i++)
2001 scrub_page_put(sblock->pagev[i]);
2002 kfree(sblock);
2003 }
2004 }
2005
2006 static void scrub_page_get(struct scrub_page *spage)
2007 {
2008 atomic_inc(&spage->refs);
2009 }
2010
2011 static void scrub_page_put(struct scrub_page *spage)
2012 {
2013 if (atomic_dec_and_test(&spage->refs)) {
2014 if (spage->page)
2015 __free_page(spage->page);
2016 kfree(spage);
2017 }
2018 }
2019
2020 static void scrub_submit(struct scrub_ctx *sctx)
2021 {
2022 struct scrub_bio *sbio;
2023
2024 if (sctx->curr == -1)
2025 return;
2026
2027 sbio = sctx->bios[sctx->curr];
2028 sctx->curr = -1;
2029 scrub_pending_bio_inc(sctx);
2030 btrfsic_submit_bio(sbio->bio);
2031 }
2032
2033 static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2034 struct scrub_page *spage)
2035 {
2036 struct scrub_block *sblock = spage->sblock;
2037 struct scrub_bio *sbio;
2038 int ret;
2039
2040 again:
2041 /*
2042 * grab a fresh bio or wait for one to become available
2043 */
2044 while (sctx->curr == -1) {
2045 spin_lock(&sctx->list_lock);
2046 sctx->curr = sctx->first_free;
2047 if (sctx->curr != -1) {
2048 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2049 sctx->bios[sctx->curr]->next_free = -1;
2050 sctx->bios[sctx->curr]->page_count = 0;
2051 spin_unlock(&sctx->list_lock);
2052 } else {
2053 spin_unlock(&sctx->list_lock);
2054 wait_event(sctx->list_wait, sctx->first_free != -1);
2055 }
2056 }
2057 sbio = sctx->bios[sctx->curr];
2058 if (sbio->page_count == 0) {
2059 struct bio *bio;
2060
2061 sbio->physical = spage->physical;
2062 sbio->logical = spage->logical;
2063 sbio->dev = spage->dev;
2064 bio = sbio->bio;
2065 if (!bio) {
2066 bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
2067 sbio->bio = bio;
2068 }
2069
2070 bio->bi_private = sbio;
2071 bio->bi_end_io = scrub_bio_end_io;
2072 bio_set_dev(bio, sbio->dev->bdev);
2073 bio->bi_iter.bi_sector = sbio->physical >> 9;
2074 bio->bi_opf = REQ_OP_READ;
2075 sbio->status = 0;
2076 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2077 spage->physical ||
2078 sbio->logical + sbio->page_count * PAGE_SIZE !=
2079 spage->logical ||
2080 sbio->dev != spage->dev) {
2081 scrub_submit(sctx);
2082 goto again;
2083 }
2084
2085 sbio->pagev[sbio->page_count] = spage;
2086 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2087 if (ret != PAGE_SIZE) {
2088 if (sbio->page_count < 1) {
2089 bio_put(sbio->bio);
2090 sbio->bio = NULL;
2091 return -EIO;
2092 }
2093 scrub_submit(sctx);
2094 goto again;
2095 }
2096
2097 scrub_block_get(sblock); /* one for the page added to the bio */
2098 atomic_inc(&sblock->outstanding_pages);
2099 sbio->page_count++;
2100 if (sbio->page_count == sctx->pages_per_rd_bio)
2101 scrub_submit(sctx);
2102
2103 return 0;
2104 }
2105
2106 static void scrub_missing_raid56_end_io(struct bio *bio)
2107 {
2108 struct scrub_block *sblock = bio->bi_private;
2109 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2110
2111 if (bio->bi_status)
2112 sblock->no_io_error_seen = 0;
2113
2114 bio_put(bio);
2115
2116 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2117 }
2118
2119 static void scrub_missing_raid56_worker(struct btrfs_work *work)
2120 {
2121 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2122 struct scrub_ctx *sctx = sblock->sctx;
2123 struct btrfs_fs_info *fs_info = sctx->fs_info;
2124 u64 logical;
2125 struct btrfs_device *dev;
2126
2127 logical = sblock->pagev[0]->logical;
2128 dev = sblock->pagev[0]->dev;
2129
2130 if (sblock->no_io_error_seen)
2131 scrub_recheck_block_checksum(sblock);
2132
2133 if (!sblock->no_io_error_seen) {
2134 spin_lock(&sctx->stat_lock);
2135 sctx->stat.read_errors++;
2136 spin_unlock(&sctx->stat_lock);
2137 btrfs_err_rl_in_rcu(fs_info,
2138 "IO error rebuilding logical %llu for dev %s",
2139 logical, rcu_str_deref(dev->name));
2140 } else if (sblock->header_error || sblock->checksum_error) {
2141 spin_lock(&sctx->stat_lock);
2142 sctx->stat.uncorrectable_errors++;
2143 spin_unlock(&sctx->stat_lock);
2144 btrfs_err_rl_in_rcu(fs_info,
2145 "failed to rebuild valid logical %llu for dev %s",
2146 logical, rcu_str_deref(dev->name));
2147 } else {
2148 scrub_write_block_to_dev_replace(sblock);
2149 }
2150
2151 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2152 mutex_lock(&sctx->wr_lock);
2153 scrub_wr_submit(sctx);
2154 mutex_unlock(&sctx->wr_lock);
2155 }
2156
2157 scrub_block_put(sblock);
2158 scrub_pending_bio_dec(sctx);
2159 }
2160
2161 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2162 {
2163 struct scrub_ctx *sctx = sblock->sctx;
2164 struct btrfs_fs_info *fs_info = sctx->fs_info;
2165 u64 length = sblock->page_count * PAGE_SIZE;
2166 u64 logical = sblock->pagev[0]->logical;
2167 struct btrfs_bio *bbio = NULL;
2168 struct bio *bio;
2169 struct btrfs_raid_bio *rbio;
2170 int ret;
2171 int i;
2172
2173 btrfs_bio_counter_inc_blocked(fs_info);
2174 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2175 &length, &bbio);
2176 if (ret || !bbio || !bbio->raid_map)
2177 goto bbio_out;
2178
2179 if (WARN_ON(!sctx->is_dev_replace ||
2180 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2181 /*
2182 * We shouldn't be scrubbing a missing device. Even for dev
2183 * replace, we should only get here for RAID 5/6. We either
2184 * managed to mount something with no mirrors remaining or
2185 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2186 */
2187 goto bbio_out;
2188 }
2189
2190 bio = btrfs_io_bio_alloc(0);
2191 bio->bi_iter.bi_sector = logical >> 9;
2192 bio->bi_private = sblock;
2193 bio->bi_end_io = scrub_missing_raid56_end_io;
2194
2195 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2196 if (!rbio)
2197 goto rbio_out;
2198
2199 for (i = 0; i < sblock->page_count; i++) {
2200 struct scrub_page *spage = sblock->pagev[i];
2201
2202 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2203 }
2204
2205 btrfs_init_work(&sblock->work, scrub_missing_raid56_worker, NULL, NULL);
2206 scrub_block_get(sblock);
2207 scrub_pending_bio_inc(sctx);
2208 raid56_submit_missing_rbio(rbio);
2209 return;
2210
2211 rbio_out:
2212 bio_put(bio);
2213 bbio_out:
2214 btrfs_bio_counter_dec(fs_info);
2215 btrfs_put_bbio(bbio);
2216 spin_lock(&sctx->stat_lock);
2217 sctx->stat.malloc_errors++;
2218 spin_unlock(&sctx->stat_lock);
2219 }
2220
2221 static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2222 u64 physical, struct btrfs_device *dev, u64 flags,
2223 u64 gen, int mirror_num, u8 *csum, int force,
2224 u64 physical_for_dev_replace)
2225 {
2226 struct scrub_block *sblock;
2227 int index;
2228
2229 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2230 if (!sblock) {
2231 spin_lock(&sctx->stat_lock);
2232 sctx->stat.malloc_errors++;
2233 spin_unlock(&sctx->stat_lock);
2234 return -ENOMEM;
2235 }
2236
2237 /* one ref inside this function, plus one for each page added to
2238 * a bio later on */
2239 refcount_set(&sblock->refs, 1);
2240 sblock->sctx = sctx;
2241 sblock->no_io_error_seen = 1;
2242
2243 for (index = 0; len > 0; index++) {
2244 struct scrub_page *spage;
2245 u64 l = min_t(u64, len, PAGE_SIZE);
2246
2247 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2248 if (!spage) {
2249 leave_nomem:
2250 spin_lock(&sctx->stat_lock);
2251 sctx->stat.malloc_errors++;
2252 spin_unlock(&sctx->stat_lock);
2253 scrub_block_put(sblock);
2254 return -ENOMEM;
2255 }
2256 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2257 scrub_page_get(spage);
2258 sblock->pagev[index] = spage;
2259 spage->sblock = sblock;
2260 spage->dev = dev;
2261 spage->flags = flags;
2262 spage->generation = gen;
2263 spage->logical = logical;
2264 spage->physical = physical;
2265 spage->physical_for_dev_replace = physical_for_dev_replace;
2266 spage->mirror_num = mirror_num;
2267 if (csum) {
2268 spage->have_csum = 1;
2269 memcpy(spage->csum, csum, sctx->csum_size);
2270 } else {
2271 spage->have_csum = 0;
2272 }
2273 sblock->page_count++;
2274 spage->page = alloc_page(GFP_KERNEL);
2275 if (!spage->page)
2276 goto leave_nomem;
2277 len -= l;
2278 logical += l;
2279 physical += l;
2280 physical_for_dev_replace += l;
2281 }
2282
2283 WARN_ON(sblock->page_count == 0);
2284 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2285 /*
2286 * This case should only be hit for RAID 5/6 device replace. See
2287 * the comment in scrub_missing_raid56_pages() for details.
2288 */
2289 scrub_missing_raid56_pages(sblock);
2290 } else {
2291 for (index = 0; index < sblock->page_count; index++) {
2292 struct scrub_page *spage = sblock->pagev[index];
2293 int ret;
2294
2295 ret = scrub_add_page_to_rd_bio(sctx, spage);
2296 if (ret) {
2297 scrub_block_put(sblock);
2298 return ret;
2299 }
2300 }
2301
2302 if (force)
2303 scrub_submit(sctx);
2304 }
2305
2306 /* last one frees, either here or in bio completion for last page */
2307 scrub_block_put(sblock);
2308 return 0;
2309 }
2310
2311 static void scrub_bio_end_io(struct bio *bio)
2312 {
2313 struct scrub_bio *sbio = bio->bi_private;
2314 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2315
2316 sbio->status = bio->bi_status;
2317 sbio->bio = bio;
2318
2319 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2320 }
2321
2322 static void scrub_bio_end_io_worker(struct btrfs_work *work)
2323 {
2324 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2325 struct scrub_ctx *sctx = sbio->sctx;
2326 int i;
2327
2328 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2329 if (sbio->status) {
2330 for (i = 0; i < sbio->page_count; i++) {
2331 struct scrub_page *spage = sbio->pagev[i];
2332
2333 spage->io_error = 1;
2334 spage->sblock->no_io_error_seen = 0;
2335 }
2336 }
2337
2338 /* now complete the scrub_block items that have all pages completed */
2339 for (i = 0; i < sbio->page_count; i++) {
2340 struct scrub_page *spage = sbio->pagev[i];
2341 struct scrub_block *sblock = spage->sblock;
2342
2343 if (atomic_dec_and_test(&sblock->outstanding_pages))
2344 scrub_block_complete(sblock);
2345 scrub_block_put(sblock);
2346 }
2347
2348 bio_put(sbio->bio);
2349 sbio->bio = NULL;
2350 spin_lock(&sctx->list_lock);
2351 sbio->next_free = sctx->first_free;
2352 sctx->first_free = sbio->index;
2353 spin_unlock(&sctx->list_lock);
2354
2355 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2356 mutex_lock(&sctx->wr_lock);
2357 scrub_wr_submit(sctx);
2358 mutex_unlock(&sctx->wr_lock);
2359 }
2360
2361 scrub_pending_bio_dec(sctx);
2362 }
2363
2364 static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2365 unsigned long *bitmap,
2366 u64 start, u64 len)
2367 {
2368 u64 offset;
2369 u64 nsectors64;
2370 u32 nsectors;
2371 int sectorsize = sparity->sctx->fs_info->sectorsize;
2372
2373 if (len >= sparity->stripe_len) {
2374 bitmap_set(bitmap, 0, sparity->nsectors);
2375 return;
2376 }
2377
2378 start -= sparity->logic_start;
2379 start = div64_u64_rem(start, sparity->stripe_len, &offset);
2380 offset = div_u64(offset, sectorsize);
2381 nsectors64 = div_u64(len, sectorsize);
2382
2383 ASSERT(nsectors64 < UINT_MAX);
2384 nsectors = (u32)nsectors64;
2385
2386 if (offset + nsectors <= sparity->nsectors) {
2387 bitmap_set(bitmap, offset, nsectors);
2388 return;
2389 }
2390
2391 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2392 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2393 }
2394
2395 static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2396 u64 start, u64 len)
2397 {
2398 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2399 }
2400
2401 static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2402 u64 start, u64 len)
2403 {
2404 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2405 }
2406
2407 static void scrub_block_complete(struct scrub_block *sblock)
2408 {
2409 int corrupted = 0;
2410
2411 if (!sblock->no_io_error_seen) {
2412 corrupted = 1;
2413 scrub_handle_errored_block(sblock);
2414 } else {
2415 /*
2416 * if has checksum error, write via repair mechanism in
2417 * dev replace case, otherwise write here in dev replace
2418 * case.
2419 */
2420 corrupted = scrub_checksum(sblock);
2421 if (!corrupted && sblock->sctx->is_dev_replace)
2422 scrub_write_block_to_dev_replace(sblock);
2423 }
2424
2425 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2426 u64 start = sblock->pagev[0]->logical;
2427 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2428 PAGE_SIZE;
2429
2430 scrub_parity_mark_sectors_error(sblock->sparity,
2431 start, end - start);
2432 }
2433 }
2434
2435 static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2436 {
2437 struct btrfs_ordered_sum *sum = NULL;
2438 unsigned long index;
2439 unsigned long num_sectors;
2440
2441 while (!list_empty(&sctx->csum_list)) {
2442 sum = list_first_entry(&sctx->csum_list,
2443 struct btrfs_ordered_sum, list);
2444 if (sum->bytenr > logical)
2445 return 0;
2446 if (sum->bytenr + sum->len > logical)
2447 break;
2448
2449 ++sctx->stat.csum_discards;
2450 list_del(&sum->list);
2451 kfree(sum);
2452 sum = NULL;
2453 }
2454 if (!sum)
2455 return 0;
2456
2457 index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
2458 ASSERT(index < UINT_MAX);
2459
2460 num_sectors = sum->len / sctx->fs_info->sectorsize;
2461 memcpy(csum, sum->sums + index * sctx->csum_size, sctx->csum_size);
2462 if (index == num_sectors - 1) {
2463 list_del(&sum->list);
2464 kfree(sum);
2465 }
2466 return 1;
2467 }
2468
2469 /* scrub extent tries to collect up to 64 kB for each bio */
2470 static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
2471 u64 logical, u64 len,
2472 u64 physical, struct btrfs_device *dev, u64 flags,
2473 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2474 {
2475 int ret;
2476 u8 csum[BTRFS_CSUM_SIZE];
2477 u32 blocksize;
2478
2479 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2480 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2481 blocksize = map->stripe_len;
2482 else
2483 blocksize = sctx->fs_info->sectorsize;
2484 spin_lock(&sctx->stat_lock);
2485 sctx->stat.data_extents_scrubbed++;
2486 sctx->stat.data_bytes_scrubbed += len;
2487 spin_unlock(&sctx->stat_lock);
2488 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2489 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2490 blocksize = map->stripe_len;
2491 else
2492 blocksize = sctx->fs_info->nodesize;
2493 spin_lock(&sctx->stat_lock);
2494 sctx->stat.tree_extents_scrubbed++;
2495 sctx->stat.tree_bytes_scrubbed += len;
2496 spin_unlock(&sctx->stat_lock);
2497 } else {
2498 blocksize = sctx->fs_info->sectorsize;
2499 WARN_ON(1);
2500 }
2501
2502 while (len) {
2503 u64 l = min_t(u64, len, blocksize);
2504 int have_csum = 0;
2505
2506 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2507 /* push csums to sbio */
2508 have_csum = scrub_find_csum(sctx, logical, csum);
2509 if (have_csum == 0)
2510 ++sctx->stat.no_csum;
2511 }
2512 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2513 mirror_num, have_csum ? csum : NULL, 0,
2514 physical_for_dev_replace);
2515 if (ret)
2516 return ret;
2517 len -= l;
2518 logical += l;
2519 physical += l;
2520 physical_for_dev_replace += l;
2521 }
2522 return 0;
2523 }
2524
2525 static int scrub_pages_for_parity(struct scrub_parity *sparity,
2526 u64 logical, u64 len,
2527 u64 physical, struct btrfs_device *dev,
2528 u64 flags, u64 gen, int mirror_num, u8 *csum)
2529 {
2530 struct scrub_ctx *sctx = sparity->sctx;
2531 struct scrub_block *sblock;
2532 int index;
2533
2534 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2535 if (!sblock) {
2536 spin_lock(&sctx->stat_lock);
2537 sctx->stat.malloc_errors++;
2538 spin_unlock(&sctx->stat_lock);
2539 return -ENOMEM;
2540 }
2541
2542 /* one ref inside this function, plus one for each page added to
2543 * a bio later on */
2544 refcount_set(&sblock->refs, 1);
2545 sblock->sctx = sctx;
2546 sblock->no_io_error_seen = 1;
2547 sblock->sparity = sparity;
2548 scrub_parity_get(sparity);
2549
2550 for (index = 0; len > 0; index++) {
2551 struct scrub_page *spage;
2552 u64 l = min_t(u64, len, PAGE_SIZE);
2553
2554 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2555 if (!spage) {
2556 leave_nomem:
2557 spin_lock(&sctx->stat_lock);
2558 sctx->stat.malloc_errors++;
2559 spin_unlock(&sctx->stat_lock);
2560 scrub_block_put(sblock);
2561 return -ENOMEM;
2562 }
2563 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2564 /* For scrub block */
2565 scrub_page_get(spage);
2566 sblock->pagev[index] = spage;
2567 /* For scrub parity */
2568 scrub_page_get(spage);
2569 list_add_tail(&spage->list, &sparity->spages);
2570 spage->sblock = sblock;
2571 spage->dev = dev;
2572 spage->flags = flags;
2573 spage->generation = gen;
2574 spage->logical = logical;
2575 spage->physical = physical;
2576 spage->mirror_num = mirror_num;
2577 if (csum) {
2578 spage->have_csum = 1;
2579 memcpy(spage->csum, csum, sctx->csum_size);
2580 } else {
2581 spage->have_csum = 0;
2582 }
2583 sblock->page_count++;
2584 spage->page = alloc_page(GFP_KERNEL);
2585 if (!spage->page)
2586 goto leave_nomem;
2587 len -= l;
2588 logical += l;
2589 physical += l;
2590 }
2591
2592 WARN_ON(sblock->page_count == 0);
2593 for (index = 0; index < sblock->page_count; index++) {
2594 struct scrub_page *spage = sblock->pagev[index];
2595 int ret;
2596
2597 ret = scrub_add_page_to_rd_bio(sctx, spage);
2598 if (ret) {
2599 scrub_block_put(sblock);
2600 return ret;
2601 }
2602 }
2603
2604 /* last one frees, either here or in bio completion for last page */
2605 scrub_block_put(sblock);
2606 return 0;
2607 }
2608
2609 static int scrub_extent_for_parity(struct scrub_parity *sparity,
2610 u64 logical, u64 len,
2611 u64 physical, struct btrfs_device *dev,
2612 u64 flags, u64 gen, int mirror_num)
2613 {
2614 struct scrub_ctx *sctx = sparity->sctx;
2615 int ret;
2616 u8 csum[BTRFS_CSUM_SIZE];
2617 u32 blocksize;
2618
2619 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2620 scrub_parity_mark_sectors_error(sparity, logical, len);
2621 return 0;
2622 }
2623
2624 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2625 blocksize = sparity->stripe_len;
2626 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2627 blocksize = sparity->stripe_len;
2628 } else {
2629 blocksize = sctx->fs_info->sectorsize;
2630 WARN_ON(1);
2631 }
2632
2633 while (len) {
2634 u64 l = min_t(u64, len, blocksize);
2635 int have_csum = 0;
2636
2637 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2638 /* push csums to sbio */
2639 have_csum = scrub_find_csum(sctx, logical, csum);
2640 if (have_csum == 0)
2641 goto skip;
2642 }
2643 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2644 flags, gen, mirror_num,
2645 have_csum ? csum : NULL);
2646 if (ret)
2647 return ret;
2648 skip:
2649 len -= l;
2650 logical += l;
2651 physical += l;
2652 }
2653 return 0;
2654 }
2655
2656 /*
2657 * Given a physical address, this will calculate it's
2658 * logical offset. if this is a parity stripe, it will return
2659 * the most left data stripe's logical offset.
2660 *
2661 * return 0 if it is a data stripe, 1 means parity stripe.
2662 */
2663 static int get_raid56_logic_offset(u64 physical, int num,
2664 struct map_lookup *map, u64 *offset,
2665 u64 *stripe_start)
2666 {
2667 int i;
2668 int j = 0;
2669 u64 stripe_nr;
2670 u64 last_offset;
2671 u32 stripe_index;
2672 u32 rot;
2673 const int data_stripes = nr_data_stripes(map);
2674
2675 last_offset = (physical - map->stripes[num].physical) * data_stripes;
2676 if (stripe_start)
2677 *stripe_start = last_offset;
2678
2679 *offset = last_offset;
2680 for (i = 0; i < data_stripes; i++) {
2681 *offset = last_offset + i * map->stripe_len;
2682
2683 stripe_nr = div64_u64(*offset, map->stripe_len);
2684 stripe_nr = div_u64(stripe_nr, data_stripes);
2685
2686 /* Work out the disk rotation on this stripe-set */
2687 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2688 /* calculate which stripe this data locates */
2689 rot += i;
2690 stripe_index = rot % map->num_stripes;
2691 if (stripe_index == num)
2692 return 0;
2693 if (stripe_index < num)
2694 j++;
2695 }
2696 *offset = last_offset + j * map->stripe_len;
2697 return 1;
2698 }
2699
2700 static void scrub_free_parity(struct scrub_parity *sparity)
2701 {
2702 struct scrub_ctx *sctx = sparity->sctx;
2703 struct scrub_page *curr, *next;
2704 int nbits;
2705
2706 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2707 if (nbits) {
2708 spin_lock(&sctx->stat_lock);
2709 sctx->stat.read_errors += nbits;
2710 sctx->stat.uncorrectable_errors += nbits;
2711 spin_unlock(&sctx->stat_lock);
2712 }
2713
2714 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2715 list_del_init(&curr->list);
2716 scrub_page_put(curr);
2717 }
2718
2719 kfree(sparity);
2720 }
2721
2722 static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2723 {
2724 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2725 work);
2726 struct scrub_ctx *sctx = sparity->sctx;
2727
2728 scrub_free_parity(sparity);
2729 scrub_pending_bio_dec(sctx);
2730 }
2731
2732 static void scrub_parity_bio_endio(struct bio *bio)
2733 {
2734 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2735 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2736
2737 if (bio->bi_status)
2738 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2739 sparity->nsectors);
2740
2741 bio_put(bio);
2742
2743 btrfs_init_work(&sparity->work, scrub_parity_bio_endio_worker, NULL,
2744 NULL);
2745 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2746 }
2747
2748 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2749 {
2750 struct scrub_ctx *sctx = sparity->sctx;
2751 struct btrfs_fs_info *fs_info = sctx->fs_info;
2752 struct bio *bio;
2753 struct btrfs_raid_bio *rbio;
2754 struct btrfs_bio *bbio = NULL;
2755 u64 length;
2756 int ret;
2757
2758 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2759 sparity->nsectors))
2760 goto out;
2761
2762 length = sparity->logic_end - sparity->logic_start;
2763
2764 btrfs_bio_counter_inc_blocked(fs_info);
2765 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2766 &length, &bbio);
2767 if (ret || !bbio || !bbio->raid_map)
2768 goto bbio_out;
2769
2770 bio = btrfs_io_bio_alloc(0);
2771 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2772 bio->bi_private = sparity;
2773 bio->bi_end_io = scrub_parity_bio_endio;
2774
2775 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2776 length, sparity->scrub_dev,
2777 sparity->dbitmap,
2778 sparity->nsectors);
2779 if (!rbio)
2780 goto rbio_out;
2781
2782 scrub_pending_bio_inc(sctx);
2783 raid56_parity_submit_scrub_rbio(rbio);
2784 return;
2785
2786 rbio_out:
2787 bio_put(bio);
2788 bbio_out:
2789 btrfs_bio_counter_dec(fs_info);
2790 btrfs_put_bbio(bbio);
2791 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2792 sparity->nsectors);
2793 spin_lock(&sctx->stat_lock);
2794 sctx->stat.malloc_errors++;
2795 spin_unlock(&sctx->stat_lock);
2796 out:
2797 scrub_free_parity(sparity);
2798 }
2799
2800 static inline int scrub_calc_parity_bitmap_len(int nsectors)
2801 {
2802 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2803 }
2804
2805 static void scrub_parity_get(struct scrub_parity *sparity)
2806 {
2807 refcount_inc(&sparity->refs);
2808 }
2809
2810 static void scrub_parity_put(struct scrub_parity *sparity)
2811 {
2812 if (!refcount_dec_and_test(&sparity->refs))
2813 return;
2814
2815 scrub_parity_check_and_repair(sparity);
2816 }
2817
2818 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2819 struct map_lookup *map,
2820 struct btrfs_device *sdev,
2821 struct btrfs_path *path,
2822 u64 logic_start,
2823 u64 logic_end)
2824 {
2825 struct btrfs_fs_info *fs_info = sctx->fs_info;
2826 struct btrfs_root *root = fs_info->extent_root;
2827 struct btrfs_root *csum_root = fs_info->csum_root;
2828 struct btrfs_extent_item *extent;
2829 struct btrfs_bio *bbio = NULL;
2830 u64 flags;
2831 int ret;
2832 int slot;
2833 struct extent_buffer *l;
2834 struct btrfs_key key;
2835 u64 generation;
2836 u64 extent_logical;
2837 u64 extent_physical;
2838 u64 extent_len;
2839 u64 mapped_length;
2840 struct btrfs_device *extent_dev;
2841 struct scrub_parity *sparity;
2842 int nsectors;
2843 int bitmap_len;
2844 int extent_mirror_num;
2845 int stop_loop = 0;
2846
2847 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2848 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2849 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2850 GFP_NOFS);
2851 if (!sparity) {
2852 spin_lock(&sctx->stat_lock);
2853 sctx->stat.malloc_errors++;
2854 spin_unlock(&sctx->stat_lock);
2855 return -ENOMEM;
2856 }
2857
2858 sparity->stripe_len = map->stripe_len;
2859 sparity->nsectors = nsectors;
2860 sparity->sctx = sctx;
2861 sparity->scrub_dev = sdev;
2862 sparity->logic_start = logic_start;
2863 sparity->logic_end = logic_end;
2864 refcount_set(&sparity->refs, 1);
2865 INIT_LIST_HEAD(&sparity->spages);
2866 sparity->dbitmap = sparity->bitmap;
2867 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2868
2869 ret = 0;
2870 while (logic_start < logic_end) {
2871 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2872 key.type = BTRFS_METADATA_ITEM_KEY;
2873 else
2874 key.type = BTRFS_EXTENT_ITEM_KEY;
2875 key.objectid = logic_start;
2876 key.offset = (u64)-1;
2877
2878 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2879 if (ret < 0)
2880 goto out;
2881
2882 if (ret > 0) {
2883 ret = btrfs_previous_extent_item(root, path, 0);
2884 if (ret < 0)
2885 goto out;
2886 if (ret > 0) {
2887 btrfs_release_path(path);
2888 ret = btrfs_search_slot(NULL, root, &key,
2889 path, 0, 0);
2890 if (ret < 0)
2891 goto out;
2892 }
2893 }
2894
2895 stop_loop = 0;
2896 while (1) {
2897 u64 bytes;
2898
2899 l = path->nodes[0];
2900 slot = path->slots[0];
2901 if (slot >= btrfs_header_nritems(l)) {
2902 ret = btrfs_next_leaf(root, path);
2903 if (ret == 0)
2904 continue;
2905 if (ret < 0)
2906 goto out;
2907
2908 stop_loop = 1;
2909 break;
2910 }
2911 btrfs_item_key_to_cpu(l, &key, slot);
2912
2913 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2914 key.type != BTRFS_METADATA_ITEM_KEY)
2915 goto next;
2916
2917 if (key.type == BTRFS_METADATA_ITEM_KEY)
2918 bytes = fs_info->nodesize;
2919 else
2920 bytes = key.offset;
2921
2922 if (key.objectid + bytes <= logic_start)
2923 goto next;
2924
2925 if (key.objectid >= logic_end) {
2926 stop_loop = 1;
2927 break;
2928 }
2929
2930 while (key.objectid >= logic_start + map->stripe_len)
2931 logic_start += map->stripe_len;
2932
2933 extent = btrfs_item_ptr(l, slot,
2934 struct btrfs_extent_item);
2935 flags = btrfs_extent_flags(l, extent);
2936 generation = btrfs_extent_generation(l, extent);
2937
2938 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2939 (key.objectid < logic_start ||
2940 key.objectid + bytes >
2941 logic_start + map->stripe_len)) {
2942 btrfs_err(fs_info,
2943 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2944 key.objectid, logic_start);
2945 spin_lock(&sctx->stat_lock);
2946 sctx->stat.uncorrectable_errors++;
2947 spin_unlock(&sctx->stat_lock);
2948 goto next;
2949 }
2950 again:
2951 extent_logical = key.objectid;
2952 extent_len = bytes;
2953
2954 if (extent_logical < logic_start) {
2955 extent_len -= logic_start - extent_logical;
2956 extent_logical = logic_start;
2957 }
2958
2959 if (extent_logical + extent_len >
2960 logic_start + map->stripe_len)
2961 extent_len = logic_start + map->stripe_len -
2962 extent_logical;
2963
2964 scrub_parity_mark_sectors_data(sparity, extent_logical,
2965 extent_len);
2966
2967 mapped_length = extent_len;
2968 bbio = NULL;
2969 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2970 extent_logical, &mapped_length, &bbio,
2971 0);
2972 if (!ret) {
2973 if (!bbio || mapped_length < extent_len)
2974 ret = -EIO;
2975 }
2976 if (ret) {
2977 btrfs_put_bbio(bbio);
2978 goto out;
2979 }
2980 extent_physical = bbio->stripes[0].physical;
2981 extent_mirror_num = bbio->mirror_num;
2982 extent_dev = bbio->stripes[0].dev;
2983 btrfs_put_bbio(bbio);
2984
2985 ret = btrfs_lookup_csums_range(csum_root,
2986 extent_logical,
2987 extent_logical + extent_len - 1,
2988 &sctx->csum_list, 1);
2989 if (ret)
2990 goto out;
2991
2992 ret = scrub_extent_for_parity(sparity, extent_logical,
2993 extent_len,
2994 extent_physical,
2995 extent_dev, flags,
2996 generation,
2997 extent_mirror_num);
2998
2999 scrub_free_csums(sctx);
3000
3001 if (ret)
3002 goto out;
3003
3004 if (extent_logical + extent_len <
3005 key.objectid + bytes) {
3006 logic_start += map->stripe_len;
3007
3008 if (logic_start >= logic_end) {
3009 stop_loop = 1;
3010 break;
3011 }
3012
3013 if (logic_start < key.objectid + bytes) {
3014 cond_resched();
3015 goto again;
3016 }
3017 }
3018 next:
3019 path->slots[0]++;
3020 }
3021
3022 btrfs_release_path(path);
3023
3024 if (stop_loop)
3025 break;
3026
3027 logic_start += map->stripe_len;
3028 }
3029 out:
3030 if (ret < 0)
3031 scrub_parity_mark_sectors_error(sparity, logic_start,
3032 logic_end - logic_start);
3033 scrub_parity_put(sparity);
3034 scrub_submit(sctx);
3035 mutex_lock(&sctx->wr_lock);
3036 scrub_wr_submit(sctx);
3037 mutex_unlock(&sctx->wr_lock);
3038
3039 btrfs_release_path(path);
3040 return ret < 0 ? ret : 0;
3041 }
3042
3043 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3044 struct map_lookup *map,
3045 struct btrfs_device *scrub_dev,
3046 int num, u64 base, u64 length)
3047 {
3048 struct btrfs_path *path, *ppath;
3049 struct btrfs_fs_info *fs_info = sctx->fs_info;
3050 struct btrfs_root *root = fs_info->extent_root;
3051 struct btrfs_root *csum_root = fs_info->csum_root;
3052 struct btrfs_extent_item *extent;
3053 struct blk_plug plug;
3054 u64 flags;
3055 int ret;
3056 int slot;
3057 u64 nstripes;
3058 struct extent_buffer *l;
3059 u64 physical;
3060 u64 logical;
3061 u64 logic_end;
3062 u64 physical_end;
3063 u64 generation;
3064 int mirror_num;
3065 struct reada_control *reada1;
3066 struct reada_control *reada2;
3067 struct btrfs_key key;
3068 struct btrfs_key key_end;
3069 u64 increment = map->stripe_len;
3070 u64 offset;
3071 u64 extent_logical;
3072 u64 extent_physical;
3073 u64 extent_len;
3074 u64 stripe_logical;
3075 u64 stripe_end;
3076 struct btrfs_device *extent_dev;
3077 int extent_mirror_num;
3078 int stop_loop = 0;
3079
3080 physical = map->stripes[num].physical;
3081 offset = 0;
3082 nstripes = div64_u64(length, map->stripe_len);
3083 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3084 offset = map->stripe_len * num;
3085 increment = map->stripe_len * map->num_stripes;
3086 mirror_num = 1;
3087 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3088 int factor = map->num_stripes / map->sub_stripes;
3089 offset = map->stripe_len * (num / map->sub_stripes);
3090 increment = map->stripe_len * factor;
3091 mirror_num = num % map->sub_stripes + 1;
3092 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
3093 increment = map->stripe_len;
3094 mirror_num = num % map->num_stripes + 1;
3095 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3096 increment = map->stripe_len;
3097 mirror_num = num % map->num_stripes + 1;
3098 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3099 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3100 increment = map->stripe_len * nr_data_stripes(map);
3101 mirror_num = 1;
3102 } else {
3103 increment = map->stripe_len;
3104 mirror_num = 1;
3105 }
3106
3107 path = btrfs_alloc_path();
3108 if (!path)
3109 return -ENOMEM;
3110
3111 ppath = btrfs_alloc_path();
3112 if (!ppath) {
3113 btrfs_free_path(path);
3114 return -ENOMEM;
3115 }
3116
3117 /*
3118 * work on commit root. The related disk blocks are static as
3119 * long as COW is applied. This means, it is save to rewrite
3120 * them to repair disk errors without any race conditions
3121 */
3122 path->search_commit_root = 1;
3123 path->skip_locking = 1;
3124
3125 ppath->search_commit_root = 1;
3126 ppath->skip_locking = 1;
3127 /*
3128 * trigger the readahead for extent tree csum tree and wait for
3129 * completion. During readahead, the scrub is officially paused
3130 * to not hold off transaction commits
3131 */
3132 logical = base + offset;
3133 physical_end = physical + nstripes * map->stripe_len;
3134 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3135 get_raid56_logic_offset(physical_end, num,
3136 map, &logic_end, NULL);
3137 logic_end += base;
3138 } else {
3139 logic_end = logical + increment * nstripes;
3140 }
3141 wait_event(sctx->list_wait,
3142 atomic_read(&sctx->bios_in_flight) == 0);
3143 scrub_blocked_if_needed(fs_info);
3144
3145 /* FIXME it might be better to start readahead at commit root */
3146 key.objectid = logical;
3147 key.type = BTRFS_EXTENT_ITEM_KEY;
3148 key.offset = (u64)0;
3149 key_end.objectid = logic_end;
3150 key_end.type = BTRFS_METADATA_ITEM_KEY;
3151 key_end.offset = (u64)-1;
3152 reada1 = btrfs_reada_add(root, &key, &key_end);
3153
3154 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3155 key.type = BTRFS_EXTENT_CSUM_KEY;
3156 key.offset = logical;
3157 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3158 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3159 key_end.offset = logic_end;
3160 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3161
3162 if (!IS_ERR(reada1))
3163 btrfs_reada_wait(reada1);
3164 if (!IS_ERR(reada2))
3165 btrfs_reada_wait(reada2);
3166
3167
3168 /*
3169 * collect all data csums for the stripe to avoid seeking during
3170 * the scrub. This might currently (crc32) end up to be about 1MB
3171 */
3172 blk_start_plug(&plug);
3173
3174 /*
3175 * now find all extents for each stripe and scrub them
3176 */
3177 ret = 0;
3178 while (physical < physical_end) {
3179 /*
3180 * canceled?
3181 */
3182 if (atomic_read(&fs_info->scrub_cancel_req) ||
3183 atomic_read(&sctx->cancel_req)) {
3184 ret = -ECANCELED;
3185 goto out;
3186 }
3187 /*
3188 * check to see if we have to pause
3189 */
3190 if (atomic_read(&fs_info->scrub_pause_req)) {
3191 /* push queued extents */
3192 sctx->flush_all_writes = true;
3193 scrub_submit(sctx);
3194 mutex_lock(&sctx->wr_lock);
3195 scrub_wr_submit(sctx);
3196 mutex_unlock(&sctx->wr_lock);
3197 wait_event(sctx->list_wait,
3198 atomic_read(&sctx->bios_in_flight) == 0);
3199 sctx->flush_all_writes = false;
3200 scrub_blocked_if_needed(fs_info);
3201 }
3202
3203 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3204 ret = get_raid56_logic_offset(physical, num, map,
3205 &logical,
3206 &stripe_logical);
3207 logical += base;
3208 if (ret) {
3209 /* it is parity strip */
3210 stripe_logical += base;
3211 stripe_end = stripe_logical + increment;
3212 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3213 ppath, stripe_logical,
3214 stripe_end);
3215 if (ret)
3216 goto out;
3217 goto skip;
3218 }
3219 }
3220
3221 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3222 key.type = BTRFS_METADATA_ITEM_KEY;
3223 else
3224 key.type = BTRFS_EXTENT_ITEM_KEY;
3225 key.objectid = logical;
3226 key.offset = (u64)-1;
3227
3228 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3229 if (ret < 0)
3230 goto out;
3231
3232 if (ret > 0) {
3233 ret = btrfs_previous_extent_item(root, path, 0);
3234 if (ret < 0)
3235 goto out;
3236 if (ret > 0) {
3237 /* there's no smaller item, so stick with the
3238 * larger one */
3239 btrfs_release_path(path);
3240 ret = btrfs_search_slot(NULL, root, &key,
3241 path, 0, 0);
3242 if (ret < 0)
3243 goto out;
3244 }
3245 }
3246
3247 stop_loop = 0;
3248 while (1) {
3249 u64 bytes;
3250
3251 l = path->nodes[0];
3252 slot = path->slots[0];
3253 if (slot >= btrfs_header_nritems(l)) {
3254 ret = btrfs_next_leaf(root, path);
3255 if (ret == 0)
3256 continue;
3257 if (ret < 0)
3258 goto out;
3259
3260 stop_loop = 1;
3261 break;
3262 }
3263 btrfs_item_key_to_cpu(l, &key, slot);
3264
3265 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3266 key.type != BTRFS_METADATA_ITEM_KEY)
3267 goto next;
3268
3269 if (key.type == BTRFS_METADATA_ITEM_KEY)
3270 bytes = fs_info->nodesize;
3271 else
3272 bytes = key.offset;
3273
3274 if (key.objectid + bytes <= logical)
3275 goto next;
3276
3277 if (key.objectid >= logical + map->stripe_len) {
3278 /* out of this device extent */
3279 if (key.objectid >= logic_end)
3280 stop_loop = 1;
3281 break;
3282 }
3283
3284 extent = btrfs_item_ptr(l, slot,
3285 struct btrfs_extent_item);
3286 flags = btrfs_extent_flags(l, extent);
3287 generation = btrfs_extent_generation(l, extent);
3288
3289 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3290 (key.objectid < logical ||
3291 key.objectid + bytes >
3292 logical + map->stripe_len)) {
3293 btrfs_err(fs_info,
3294 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3295 key.objectid, logical);
3296 spin_lock(&sctx->stat_lock);
3297 sctx->stat.uncorrectable_errors++;
3298 spin_unlock(&sctx->stat_lock);
3299 goto next;
3300 }
3301
3302 again:
3303 extent_logical = key.objectid;
3304 extent_len = bytes;
3305
3306 /*
3307 * trim extent to this stripe
3308 */
3309 if (extent_logical < logical) {
3310 extent_len -= logical - extent_logical;
3311 extent_logical = logical;
3312 }
3313 if (extent_logical + extent_len >
3314 logical + map->stripe_len) {
3315 extent_len = logical + map->stripe_len -
3316 extent_logical;
3317 }
3318
3319 extent_physical = extent_logical - logical + physical;
3320 extent_dev = scrub_dev;
3321 extent_mirror_num = mirror_num;
3322 if (sctx->is_dev_replace)
3323 scrub_remap_extent(fs_info, extent_logical,
3324 extent_len, &extent_physical,
3325 &extent_dev,
3326 &extent_mirror_num);
3327
3328 ret = btrfs_lookup_csums_range(csum_root,
3329 extent_logical,
3330 extent_logical +
3331 extent_len - 1,
3332 &sctx->csum_list, 1);
3333 if (ret)
3334 goto out;
3335
3336 ret = scrub_extent(sctx, map, extent_logical, extent_len,
3337 extent_physical, extent_dev, flags,
3338 generation, extent_mirror_num,
3339 extent_logical - logical + physical);
3340
3341 scrub_free_csums(sctx);
3342
3343 if (ret)
3344 goto out;
3345
3346 if (extent_logical + extent_len <
3347 key.objectid + bytes) {
3348 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3349 /*
3350 * loop until we find next data stripe
3351 * or we have finished all stripes.
3352 */
3353 loop:
3354 physical += map->stripe_len;
3355 ret = get_raid56_logic_offset(physical,
3356 num, map, &logical,
3357 &stripe_logical);
3358 logical += base;
3359
3360 if (ret && physical < physical_end) {
3361 stripe_logical += base;
3362 stripe_end = stripe_logical +
3363 increment;
3364 ret = scrub_raid56_parity(sctx,
3365 map, scrub_dev, ppath,
3366 stripe_logical,
3367 stripe_end);
3368 if (ret)
3369 goto out;
3370 goto loop;
3371 }
3372 } else {
3373 physical += map->stripe_len;
3374 logical += increment;
3375 }
3376 if (logical < key.objectid + bytes) {
3377 cond_resched();
3378 goto again;
3379 }
3380
3381 if (physical >= physical_end) {
3382 stop_loop = 1;
3383 break;
3384 }
3385 }
3386 next:
3387 path->slots[0]++;
3388 }
3389 btrfs_release_path(path);
3390 skip:
3391 logical += increment;
3392 physical += map->stripe_len;
3393 spin_lock(&sctx->stat_lock);
3394 if (stop_loop)
3395 sctx->stat.last_physical = map->stripes[num].physical +
3396 length;
3397 else
3398 sctx->stat.last_physical = physical;
3399 spin_unlock(&sctx->stat_lock);
3400 if (stop_loop)
3401 break;
3402 }
3403 out:
3404 /* push queued extents */
3405 scrub_submit(sctx);
3406 mutex_lock(&sctx->wr_lock);
3407 scrub_wr_submit(sctx);
3408 mutex_unlock(&sctx->wr_lock);
3409
3410 blk_finish_plug(&plug);
3411 btrfs_free_path(path);
3412 btrfs_free_path(ppath);
3413 return ret < 0 ? ret : 0;
3414 }
3415
3416 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3417 struct btrfs_device *scrub_dev,
3418 u64 chunk_offset, u64 length,
3419 u64 dev_offset,
3420 struct btrfs_block_group *cache)
3421 {
3422 struct btrfs_fs_info *fs_info = sctx->fs_info;
3423 struct extent_map_tree *map_tree = &fs_info->mapping_tree;
3424 struct map_lookup *map;
3425 struct extent_map *em;
3426 int i;
3427 int ret = 0;
3428
3429 read_lock(&map_tree->lock);
3430 em = lookup_extent_mapping(map_tree, chunk_offset, 1);
3431 read_unlock(&map_tree->lock);
3432
3433 if (!em) {
3434 /*
3435 * Might have been an unused block group deleted by the cleaner
3436 * kthread or relocation.
3437 */
3438 spin_lock(&cache->lock);
3439 if (!cache->removed)
3440 ret = -EINVAL;
3441 spin_unlock(&cache->lock);
3442
3443 return ret;
3444 }
3445
3446 map = em->map_lookup;
3447 if (em->start != chunk_offset)
3448 goto out;
3449
3450 if (em->len < length)
3451 goto out;
3452
3453 for (i = 0; i < map->num_stripes; ++i) {
3454 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3455 map->stripes[i].physical == dev_offset) {
3456 ret = scrub_stripe(sctx, map, scrub_dev, i,
3457 chunk_offset, length);
3458 if (ret)
3459 goto out;
3460 }
3461 }
3462 out:
3463 free_extent_map(em);
3464
3465 return ret;
3466 }
3467
3468 static noinline_for_stack
3469 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3470 struct btrfs_device *scrub_dev, u64 start, u64 end)
3471 {
3472 struct btrfs_dev_extent *dev_extent = NULL;
3473 struct btrfs_path *path;
3474 struct btrfs_fs_info *fs_info = sctx->fs_info;
3475 struct btrfs_root *root = fs_info->dev_root;
3476 u64 length;
3477 u64 chunk_offset;
3478 int ret = 0;
3479 int ro_set;
3480 int slot;
3481 struct extent_buffer *l;
3482 struct btrfs_key key;
3483 struct btrfs_key found_key;
3484 struct btrfs_block_group *cache;
3485 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3486
3487 path = btrfs_alloc_path();
3488 if (!path)
3489 return -ENOMEM;
3490
3491 path->reada = READA_FORWARD;
3492 path->search_commit_root = 1;
3493 path->skip_locking = 1;
3494
3495 key.objectid = scrub_dev->devid;
3496 key.offset = 0ull;
3497 key.type = BTRFS_DEV_EXTENT_KEY;
3498
3499 while (1) {
3500 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3501 if (ret < 0)
3502 break;
3503 if (ret > 0) {
3504 if (path->slots[0] >=
3505 btrfs_header_nritems(path->nodes[0])) {
3506 ret = btrfs_next_leaf(root, path);
3507 if (ret < 0)
3508 break;
3509 if (ret > 0) {
3510 ret = 0;
3511 break;
3512 }
3513 } else {
3514 ret = 0;
3515 }
3516 }
3517
3518 l = path->nodes[0];
3519 slot = path->slots[0];
3520
3521 btrfs_item_key_to_cpu(l, &found_key, slot);
3522
3523 if (found_key.objectid != scrub_dev->devid)
3524 break;
3525
3526 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3527 break;
3528
3529 if (found_key.offset >= end)
3530 break;
3531
3532 if (found_key.offset < key.offset)
3533 break;
3534
3535 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3536 length = btrfs_dev_extent_length(l, dev_extent);
3537
3538 if (found_key.offset + length <= start)
3539 goto skip;
3540
3541 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3542
3543 /*
3544 * get a reference on the corresponding block group to prevent
3545 * the chunk from going away while we scrub it
3546 */
3547 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3548
3549 /* some chunks are removed but not committed to disk yet,
3550 * continue scrubbing */
3551 if (!cache)
3552 goto skip;
3553
3554 /*
3555 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3556 * to avoid deadlock caused by:
3557 * btrfs_inc_block_group_ro()
3558 * -> btrfs_wait_for_commit()
3559 * -> btrfs_commit_transaction()
3560 * -> btrfs_scrub_pause()
3561 */
3562 scrub_pause_on(fs_info);
3563
3564 /*
3565 * Don't do chunk preallocation for scrub.
3566 *
3567 * This is especially important for SYSTEM bgs, or we can hit
3568 * -EFBIG from btrfs_finish_chunk_alloc() like:
3569 * 1. The only SYSTEM bg is marked RO.
3570 * Since SYSTEM bg is small, that's pretty common.
3571 * 2. New SYSTEM bg will be allocated
3572 * Due to regular version will allocate new chunk.
3573 * 3. New SYSTEM bg is empty and will get cleaned up
3574 * Before cleanup really happens, it's marked RO again.
3575 * 4. Empty SYSTEM bg get scrubbed
3576 * We go back to 2.
3577 *
3578 * This can easily boost the amount of SYSTEM chunks if cleaner
3579 * thread can't be triggered fast enough, and use up all space
3580 * of btrfs_super_block::sys_chunk_array
3581 *
3582 * While for dev replace, we need to try our best to mark block
3583 * group RO, to prevent race between:
3584 * - Write duplication
3585 * Contains latest data
3586 * - Scrub copy
3587 * Contains data from commit tree
3588 *
3589 * If target block group is not marked RO, nocow writes can
3590 * be overwritten by scrub copy, causing data corruption.
3591 * So for dev-replace, it's not allowed to continue if a block
3592 * group is not RO.
3593 */
3594 ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
3595 if (ret == 0) {
3596 ro_set = 1;
3597 } else if (ret == -ENOSPC && !sctx->is_dev_replace) {
3598 /*
3599 * btrfs_inc_block_group_ro return -ENOSPC when it
3600 * failed in creating new chunk for metadata.
3601 * It is not a problem for scrub, because
3602 * metadata are always cowed, and our scrub paused
3603 * commit_transactions.
3604 */
3605 ro_set = 0;
3606 } else {
3607 btrfs_warn(fs_info,
3608 "failed setting block group ro: %d", ret);
3609 btrfs_put_block_group(cache);
3610 scrub_pause_off(fs_info);
3611 break;
3612 }
3613
3614 /*
3615 * Now the target block is marked RO, wait for nocow writes to
3616 * finish before dev-replace.
3617 * COW is fine, as COW never overwrites extents in commit tree.
3618 */
3619 if (sctx->is_dev_replace) {
3620 btrfs_wait_nocow_writers(cache);
3621 btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
3622 cache->length);
3623 }
3624
3625 scrub_pause_off(fs_info);
3626 down_write(&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(&dev_replace->rwsem);
3668 dev_replace->cursor_left = dev_replace->cursor_right;
3669 dev_replace->item_needs_writeback = 1;
3670 up_write(&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 cache->used == 0) {
3685 spin_unlock(&cache->lock);
3686 if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
3687 btrfs_discard_queue_work(&fs_info->discard_ctl,
3688 cache);
3689 else
3690 btrfs_mark_bg_unused(cache);
3691 } else {
3692 spin_unlock(&cache->lock);
3693 }
3694
3695 btrfs_put_block_group(cache);
3696 if (ret)
3697 break;
3698 if (sctx->is_dev_replace &&
3699 atomic64_read(&dev_replace->num_write_errors) > 0) {
3700 ret = -EIO;
3701 break;
3702 }
3703 if (sctx->stat.malloc_errors > 0) {
3704 ret = -ENOMEM;
3705 break;
3706 }
3707 skip:
3708 key.offset = found_key.offset + length;
3709 btrfs_release_path(path);
3710 }
3711
3712 btrfs_free_path(path);
3713
3714 return ret;
3715 }
3716
3717 static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3718 struct btrfs_device *scrub_dev)
3719 {
3720 int i;
3721 u64 bytenr;
3722 u64 gen;
3723 int ret;
3724 struct btrfs_fs_info *fs_info = sctx->fs_info;
3725
3726 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3727 return -EIO;
3728
3729 /* Seed devices of a new filesystem has their own generation. */
3730 if (scrub_dev->fs_devices != fs_info->fs_devices)
3731 gen = scrub_dev->generation;
3732 else
3733 gen = fs_info->last_trans_committed;
3734
3735 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3736 bytenr = btrfs_sb_offset(i);
3737 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3738 scrub_dev->commit_total_bytes)
3739 break;
3740
3741 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3742 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3743 NULL, 1, bytenr);
3744 if (ret)
3745 return ret;
3746 }
3747 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3748
3749 return 0;
3750 }
3751
3752 /*
3753 * get a reference count on fs_info->scrub_workers. start worker if necessary
3754 */
3755 static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3756 int is_dev_replace)
3757 {
3758 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3759 int max_active = fs_info->thread_pool_size;
3760
3761 lockdep_assert_held(&fs_info->scrub_lock);
3762
3763 if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
3764 ASSERT(fs_info->scrub_workers == NULL);
3765 fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
3766 flags, is_dev_replace ? 1 : max_active, 4);
3767 if (!fs_info->scrub_workers)
3768 goto fail_scrub_workers;
3769
3770 ASSERT(fs_info->scrub_wr_completion_workers == NULL);
3771 fs_info->scrub_wr_completion_workers =
3772 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3773 max_active, 2);
3774 if (!fs_info->scrub_wr_completion_workers)
3775 goto fail_scrub_wr_completion_workers;
3776
3777 ASSERT(fs_info->scrub_parity_workers == NULL);
3778 fs_info->scrub_parity_workers =
3779 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3780 max_active, 2);
3781 if (!fs_info->scrub_parity_workers)
3782 goto fail_scrub_parity_workers;
3783
3784 refcount_set(&fs_info->scrub_workers_refcnt, 1);
3785 } else {
3786 refcount_inc(&fs_info->scrub_workers_refcnt);
3787 }
3788 return 0;
3789
3790 fail_scrub_parity_workers:
3791 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3792 fail_scrub_wr_completion_workers:
3793 btrfs_destroy_workqueue(fs_info->scrub_workers);
3794 fail_scrub_workers:
3795 return -ENOMEM;
3796 }
3797
3798 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3799 u64 end, struct btrfs_scrub_progress *progress,
3800 int readonly, int is_dev_replace)
3801 {
3802 struct scrub_ctx *sctx;
3803 int ret;
3804 struct btrfs_device *dev;
3805 unsigned int nofs_flag;
3806 struct btrfs_workqueue *scrub_workers = NULL;
3807 struct btrfs_workqueue *scrub_wr_comp = NULL;
3808 struct btrfs_workqueue *scrub_parity = NULL;
3809
3810 if (btrfs_fs_closing(fs_info))
3811 return -EAGAIN;
3812
3813 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3814 /*
3815 * in this case scrub is unable to calculate the checksum
3816 * the way scrub is implemented. Do not handle this
3817 * situation at all because it won't ever happen.
3818 */
3819 btrfs_err(fs_info,
3820 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3821 fs_info->nodesize,
3822 BTRFS_STRIPE_LEN);
3823 return -EINVAL;
3824 }
3825
3826 if (fs_info->sectorsize != PAGE_SIZE) {
3827 /* not supported for data w/o checksums */
3828 btrfs_err_rl(fs_info,
3829 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3830 fs_info->sectorsize, PAGE_SIZE);
3831 return -EINVAL;
3832 }
3833
3834 if (fs_info->nodesize >
3835 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3836 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3837 /*
3838 * would exhaust the array bounds of pagev member in
3839 * struct scrub_block
3840 */
3841 btrfs_err(fs_info,
3842 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3843 fs_info->nodesize,
3844 SCRUB_MAX_PAGES_PER_BLOCK,
3845 fs_info->sectorsize,
3846 SCRUB_MAX_PAGES_PER_BLOCK);
3847 return -EINVAL;
3848 }
3849
3850 /* Allocate outside of device_list_mutex */
3851 sctx = scrub_setup_ctx(fs_info, is_dev_replace);
3852 if (IS_ERR(sctx))
3853 return PTR_ERR(sctx);
3854
3855 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3856 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
3857 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
3858 !is_dev_replace)) {
3859 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3860 ret = -ENODEV;
3861 goto out_free_ctx;
3862 }
3863
3864 if (!is_dev_replace && !readonly &&
3865 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
3866 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3867 btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
3868 rcu_str_deref(dev->name));
3869 ret = -EROFS;
3870 goto out_free_ctx;
3871 }
3872
3873 mutex_lock(&fs_info->scrub_lock);
3874 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3875 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
3876 mutex_unlock(&fs_info->scrub_lock);
3877 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3878 ret = -EIO;
3879 goto out_free_ctx;
3880 }
3881
3882 down_read(&fs_info->dev_replace.rwsem);
3883 if (dev->scrub_ctx ||
3884 (!is_dev_replace &&
3885 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3886 up_read(&fs_info->dev_replace.rwsem);
3887 mutex_unlock(&fs_info->scrub_lock);
3888 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3889 ret = -EINPROGRESS;
3890 goto out_free_ctx;
3891 }
3892 up_read(&fs_info->dev_replace.rwsem);
3893
3894 ret = scrub_workers_get(fs_info, is_dev_replace);
3895 if (ret) {
3896 mutex_unlock(&fs_info->scrub_lock);
3897 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3898 goto out_free_ctx;
3899 }
3900
3901 sctx->readonly = readonly;
3902 dev->scrub_ctx = sctx;
3903 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3904
3905 /*
3906 * checking @scrub_pause_req here, we can avoid
3907 * race between committing transaction and scrubbing.
3908 */
3909 __scrub_blocked_if_needed(fs_info);
3910 atomic_inc(&fs_info->scrubs_running);
3911 mutex_unlock(&fs_info->scrub_lock);
3912
3913 /*
3914 * In order to avoid deadlock with reclaim when there is a transaction
3915 * trying to pause scrub, make sure we use GFP_NOFS for all the
3916 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
3917 * invoked by our callees. The pausing request is done when the
3918 * transaction commit starts, and it blocks the transaction until scrub
3919 * is paused (done at specific points at scrub_stripe() or right above
3920 * before incrementing fs_info->scrubs_running).
3921 */
3922 nofs_flag = memalloc_nofs_save();
3923 if (!is_dev_replace) {
3924 btrfs_info(fs_info, "scrub: started on devid %llu", devid);
3925 /*
3926 * by holding device list mutex, we can
3927 * kick off writing super in log tree sync.
3928 */
3929 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3930 ret = scrub_supers(sctx, dev);
3931 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3932 }
3933
3934 if (!ret)
3935 ret = scrub_enumerate_chunks(sctx, dev, start, end);
3936 memalloc_nofs_restore(nofs_flag);
3937
3938 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3939 atomic_dec(&fs_info->scrubs_running);
3940 wake_up(&fs_info->scrub_pause_wait);
3941
3942 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3943
3944 if (progress)
3945 memcpy(progress, &sctx->stat, sizeof(*progress));
3946
3947 if (!is_dev_replace)
3948 btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
3949 ret ? "not finished" : "finished", devid, ret);
3950
3951 mutex_lock(&fs_info->scrub_lock);
3952 dev->scrub_ctx = NULL;
3953 if (refcount_dec_and_test(&fs_info->scrub_workers_refcnt)) {
3954 scrub_workers = fs_info->scrub_workers;
3955 scrub_wr_comp = fs_info->scrub_wr_completion_workers;
3956 scrub_parity = fs_info->scrub_parity_workers;
3957
3958 fs_info->scrub_workers = NULL;
3959 fs_info->scrub_wr_completion_workers = NULL;
3960 fs_info->scrub_parity_workers = NULL;
3961 }
3962 mutex_unlock(&fs_info->scrub_lock);
3963
3964 btrfs_destroy_workqueue(scrub_workers);
3965 btrfs_destroy_workqueue(scrub_wr_comp);
3966 btrfs_destroy_workqueue(scrub_parity);
3967 scrub_put_ctx(sctx);
3968
3969 return ret;
3970
3971 out_free_ctx:
3972 scrub_free_ctx(sctx);
3973
3974 return ret;
3975 }
3976
3977 void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3978 {
3979 mutex_lock(&fs_info->scrub_lock);
3980 atomic_inc(&fs_info->scrub_pause_req);
3981 while (atomic_read(&fs_info->scrubs_paused) !=
3982 atomic_read(&fs_info->scrubs_running)) {
3983 mutex_unlock(&fs_info->scrub_lock);
3984 wait_event(fs_info->scrub_pause_wait,
3985 atomic_read(&fs_info->scrubs_paused) ==
3986 atomic_read(&fs_info->scrubs_running));
3987 mutex_lock(&fs_info->scrub_lock);
3988 }
3989 mutex_unlock(&fs_info->scrub_lock);
3990 }
3991
3992 void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3993 {
3994 atomic_dec(&fs_info->scrub_pause_req);
3995 wake_up(&fs_info->scrub_pause_wait);
3996 }
3997
3998 int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3999 {
4000 mutex_lock(&fs_info->scrub_lock);
4001 if (!atomic_read(&fs_info->scrubs_running)) {
4002 mutex_unlock(&fs_info->scrub_lock);
4003 return -ENOTCONN;
4004 }
4005
4006 atomic_inc(&fs_info->scrub_cancel_req);
4007 while (atomic_read(&fs_info->scrubs_running)) {
4008 mutex_unlock(&fs_info->scrub_lock);
4009 wait_event(fs_info->scrub_pause_wait,
4010 atomic_read(&fs_info->scrubs_running) == 0);
4011 mutex_lock(&fs_info->scrub_lock);
4012 }
4013 atomic_dec(&fs_info->scrub_cancel_req);
4014 mutex_unlock(&fs_info->scrub_lock);
4015
4016 return 0;
4017 }
4018
4019 int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
4020 {
4021 struct btrfs_fs_info *fs_info = dev->fs_info;
4022 struct scrub_ctx *sctx;
4023
4024 mutex_lock(&fs_info->scrub_lock);
4025 sctx = dev->scrub_ctx;
4026 if (!sctx) {
4027 mutex_unlock(&fs_info->scrub_lock);
4028 return -ENOTCONN;
4029 }
4030 atomic_inc(&sctx->cancel_req);
4031 while (dev->scrub_ctx) {
4032 mutex_unlock(&fs_info->scrub_lock);
4033 wait_event(fs_info->scrub_pause_wait,
4034 dev->scrub_ctx == NULL);
4035 mutex_lock(&fs_info->scrub_lock);
4036 }
4037 mutex_unlock(&fs_info->scrub_lock);
4038
4039 return 0;
4040 }
4041
4042 int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4043 struct btrfs_scrub_progress *progress)
4044 {
4045 struct btrfs_device *dev;
4046 struct scrub_ctx *sctx = NULL;
4047
4048 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4049 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
4050 if (dev)
4051 sctx = dev->scrub_ctx;
4052 if (sctx)
4053 memcpy(progress, &sctx->stat, sizeof(*progress));
4054 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4055
4056 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4057 }
4058
4059 static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4060 u64 extent_logical, u64 extent_len,
4061 u64 *extent_physical,
4062 struct btrfs_device **extent_dev,
4063 int *extent_mirror_num)
4064 {
4065 u64 mapped_length;
4066 struct btrfs_bio *bbio = NULL;
4067 int ret;
4068
4069 mapped_length = extent_len;
4070 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4071 &mapped_length, &bbio, 0);
4072 if (ret || !bbio || mapped_length < extent_len ||
4073 !bbio->stripes[0].dev->bdev) {
4074 btrfs_put_bbio(bbio);
4075 return;
4076 }
4077
4078 *extent_physical = bbio->stripes[0].physical;
4079 *extent_mirror_num = bbio->mirror_num;
4080 *extent_dev = bbio->stripes[0].dev;
4081 btrfs_put_bbio(bbio);
4082 }
Linux with added FPC-III support