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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011, 2012 STRATO. All rights reserved.
4 */
5
6#include <linux/blkdev.h>
7#include <linux/ratelimit.h>
8#include <linux/sched/mm.h>
9#include <crypto/hash.h>
10#include "ctree.h"
11#include "volumes.h"
12#include "disk-io.h"
13#include "ordered-data.h"
14#include "transaction.h"
15#include "backref.h"
16#include "extent_io.h"
17#include "dev-replace.h"
18#include "check-integrity.h"
19#include "rcu-string.h"
20#include "raid56.h"
21#include "block-group.h"
22
23/*
24 * This is only the first step towards a full-features scrub. It reads all
25 * extent and super block and verifies the checksums. In case a bad checksum
26 * is found or the extent cannot be read, good data will be written back if
27 * any can be found.
28 *
29 * Future enhancements:
30 * - In case an unrepairable extent is encountered, track which files are
31 * affected and report them
32 * - track and record media errors, throw out bad devices
33 * - add a mode to also read unallocated space
34 */
35
36struct scrub_block;
37struct scrub_ctx;
38
39/*
40 * the following three values only influence the performance.
41 * The last one configures the number of parallel and outstanding I/O
42 * operations. The first two values configure an upper limit for the number
43 * of (dynamically allocated) pages that are added to a bio.
44 */
45#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
46#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
47#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
48
49/*
50 * the following value times PAGE_SIZE needs to be large enough to match the
51 * largest node/leaf/sector size that shall be supported.
52 * Values larger than BTRFS_STRIPE_LEN are not supported.
53 */
54#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
55
56struct scrub_recover {
57 refcount_t refs;
58 struct btrfs_bio *bbio;
59 u64 map_length;
60};
61
62struct scrub_page {
63 struct scrub_block *sblock;
64 struct page *page;
65 struct btrfs_device *dev;
66 struct list_head list;
67 u64 flags; /* extent flags */
68 u64 generation;
69 u64 logical;
70 u64 physical;
71 u64 physical_for_dev_replace;
72 atomic_t refs;
73 struct {
74 unsigned int mirror_num:8;
75 unsigned int have_csum:1;
76 unsigned int io_error:1;
77 };
78 u8 csum[BTRFS_CSUM_SIZE];
79
80 struct scrub_recover *recover;
81};
82
83struct scrub_bio {
84 int index;
85 struct scrub_ctx *sctx;
86 struct btrfs_device *dev;
87 struct bio *bio;
88 blk_status_t status;
89 u64 logical;
90 u64 physical;
91#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
92 struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
93#else
94 struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
95#endif
96 int page_count;
97 int next_free;
98 struct btrfs_work work;
99};
100
101struct scrub_block {
102 struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
103 int page_count;
104 atomic_t outstanding_pages;
105 refcount_t refs; /* free mem on transition to zero */
106 struct scrub_ctx *sctx;
107 struct scrub_parity *sparity;
108 struct {
109 unsigned int header_error:1;
110 unsigned int checksum_error:1;
111 unsigned int no_io_error_seen:1;
112 unsigned int generation_error:1; /* also sets header_error */
113
114 /* The following is for the data used to check parity */
115 /* It is for the data with checksum */
116 unsigned int data_corrected:1;
117 };
118 struct btrfs_work work;
119};
120
121/* Used for the chunks with parity stripe such RAID5/6 */
122struct scrub_parity {
123 struct scrub_ctx *sctx;
124
125 struct btrfs_device *scrub_dev;
126
127 u64 logic_start;
128
129 u64 logic_end;
130
131 int nsectors;
132
133 u64 stripe_len;
134
135 refcount_t refs;
136
137 struct list_head spages;
138
139 /* Work of parity check and repair */
140 struct btrfs_work work;
141
142 /* Mark the parity blocks which have data */
143 unsigned long *dbitmap;
144
145 /*
146 * Mark the parity blocks which have data, but errors happen when
147 * read data or check data
148 */
149 unsigned long *ebitmap;
150
151 unsigned long bitmap[0];
152};
153
154struct scrub_ctx {
155 struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
156 struct btrfs_fs_info *fs_info;
157 int first_free;
158 int curr;
159 atomic_t bios_in_flight;
160 atomic_t workers_pending;
161 spinlock_t list_lock;
162 wait_queue_head_t list_wait;
163 u16 csum_size;
164 struct list_head csum_list;
165 atomic_t cancel_req;
166 int readonly;
167 int pages_per_rd_bio;
168
169 int is_dev_replace;
170
171 struct scrub_bio *wr_curr_bio;
172 struct mutex wr_lock;
173 int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
174 struct btrfs_device *wr_tgtdev;
175 bool flush_all_writes;
176
177 /*
178 * statistics
179 */
180 struct btrfs_scrub_progress stat;
181 spinlock_t stat_lock;
182
183 /*
184 * Use a ref counter to avoid use-after-free issues. Scrub workers
185 * decrement bios_in_flight and workers_pending and then do a wakeup
186 * on the list_wait wait queue. We must ensure the main scrub task
187 * doesn't free the scrub context before or while the workers are
188 * doing the wakeup() call.
189 */
190 refcount_t refs;
191};
192
193struct scrub_warning {
194 struct btrfs_path *path;
195 u64 extent_item_size;
196 const char *errstr;
197 u64 physical;
198 u64 logical;
199 struct btrfs_device *dev;
200};
201
202struct full_stripe_lock {
203 struct rb_node node;
204 u64 logical;
205 u64 refs;
206 struct mutex mutex;
207};
208
209static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
210static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
211static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
212static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
213 struct scrub_block *sblocks_for_recheck);
214static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
215 struct scrub_block *sblock,
216 int retry_failed_mirror);
217static void scrub_recheck_block_checksum(struct scrub_block *sblock);
218static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
219 struct scrub_block *sblock_good);
220static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
221 struct scrub_block *sblock_good,
222 int page_num, int force_write);
223static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
224static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
225 int page_num);
226static int scrub_checksum_data(struct scrub_block *sblock);
227static int scrub_checksum_tree_block(struct scrub_block *sblock);
228static int scrub_checksum_super(struct scrub_block *sblock);
229static void scrub_block_get(struct scrub_block *sblock);
230static void scrub_block_put(struct scrub_block *sblock);
231static void scrub_page_get(struct scrub_page *spage);
232static void scrub_page_put(struct scrub_page *spage);
233static void scrub_parity_get(struct scrub_parity *sparity);
234static void scrub_parity_put(struct scrub_parity *sparity);
235static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
236 struct scrub_page *spage);
237static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
238 u64 physical, struct btrfs_device *dev, u64 flags,
239 u64 gen, int mirror_num, u8 *csum, int force,
240 u64 physical_for_dev_replace);
241static void scrub_bio_end_io(struct bio *bio);
242static void scrub_bio_end_io_worker(struct btrfs_work *work);
243static void scrub_block_complete(struct scrub_block *sblock);
244static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
245 u64 extent_logical, u64 extent_len,
246 u64 *extent_physical,
247 struct btrfs_device **extent_dev,
248 int *extent_mirror_num);
249static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
250 struct scrub_page *spage);
251static void scrub_wr_submit(struct scrub_ctx *sctx);
252static void scrub_wr_bio_end_io(struct bio *bio);
253static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
254static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
255static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
256static void scrub_put_ctx(struct scrub_ctx *sctx);
257
258static inline int scrub_is_page_on_raid56(struct scrub_page *page)
259{
260 return page->recover &&
261 (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
262}
263
264static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
265{
266 refcount_inc(&sctx->refs);
267 atomic_inc(&sctx->bios_in_flight);
268}
269
270static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
271{
272 atomic_dec(&sctx->bios_in_flight);
273 wake_up(&sctx->list_wait);
274 scrub_put_ctx(sctx);
275}
276
277static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
278{
279 while (atomic_read(&fs_info->scrub_pause_req)) {
280 mutex_unlock(&fs_info->scrub_lock);
281 wait_event(fs_info->scrub_pause_wait,
282 atomic_read(&fs_info->scrub_pause_req) == 0);
283 mutex_lock(&fs_info->scrub_lock);
284 }
285}
286
287static void scrub_pause_on(struct btrfs_fs_info *fs_info)
288{
289 atomic_inc(&fs_info->scrubs_paused);
290 wake_up(&fs_info->scrub_pause_wait);
291}
292
293static void scrub_pause_off(struct btrfs_fs_info *fs_info)
294{
295 mutex_lock(&fs_info->scrub_lock);
296 __scrub_blocked_if_needed(fs_info);
297 atomic_dec(&fs_info->scrubs_paused);
298 mutex_unlock(&fs_info->scrub_lock);
299
300 wake_up(&fs_info->scrub_pause_wait);
301}
302
303static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
304{
305 scrub_pause_on(fs_info);
306 scrub_pause_off(fs_info);
307}
308
309/*
310 * Insert new full stripe lock into full stripe locks tree
311 *
312 * Return pointer to existing or newly inserted full_stripe_lock structure if
313 * everything works well.
314 * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
315 *
316 * NOTE: caller must hold full_stripe_locks_root->lock before calling this
317 * function
318 */
319static struct full_stripe_lock *insert_full_stripe_lock(
320 struct btrfs_full_stripe_locks_tree *locks_root,
321 u64 fstripe_logical)
322{
323 struct rb_node **p;
324 struct rb_node *parent = NULL;
325 struct full_stripe_lock *entry;
326 struct full_stripe_lock *ret;
327
328 lockdep_assert_held(&locks_root->lock);
329
330 p = &locks_root->root.rb_node;
331 while (*p) {
332 parent = *p;
333 entry = rb_entry(parent, struct full_stripe_lock, node);
334 if (fstripe_logical < entry->logical) {
335 p = &(*p)->rb_left;
336 } else if (fstripe_logical > entry->logical) {
337 p = &(*p)->rb_right;
338 } else {
339 entry->refs++;
340 return entry;
341 }
342 }
343
344 /*
345 * Insert new lock.
346 */
347 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
348 if (!ret)
349 return ERR_PTR(-ENOMEM);
350 ret->logical = fstripe_logical;
351 ret->refs = 1;
352 mutex_init(&ret->mutex);
353
354 rb_link_node(&ret->node, parent, p);
355 rb_insert_color(&ret->node, &locks_root->root);
356 return ret;
357}
358
359/*
360 * Search for a full stripe lock of a block group
361 *
362 * Return pointer to existing full stripe lock if found
363 * Return NULL if not found
364 */
365static struct full_stripe_lock *search_full_stripe_lock(
366 struct btrfs_full_stripe_locks_tree *locks_root,
367 u64 fstripe_logical)
368{
369 struct rb_node *node;
370 struct full_stripe_lock *entry;
371
372 lockdep_assert_held(&locks_root->lock);
373
374 node = locks_root->root.rb_node;
375 while (node) {
376 entry = rb_entry(node, struct full_stripe_lock, node);
377 if (fstripe_logical < entry->logical)
378 node = node->rb_left;
379 else if (fstripe_logical > entry->logical)
380 node = node->rb_right;
381 else
382 return entry;
383 }
384 return NULL;
385}
386
387/*
388 * Helper to get full stripe logical from a normal bytenr.
389 *
390 * Caller must ensure @cache is a RAID56 block group.
391 */
392static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
393 u64 bytenr)
394{
395 u64 ret;
396
397 /*
398 * Due to chunk item size limit, full stripe length should not be
399 * larger than U32_MAX. Just a sanity check here.
400 */
401 WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
402
403 /*
404 * round_down() can only handle power of 2, while RAID56 full
405 * stripe length can be 64KiB * n, so we need to manually round down.
406 */
407 ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
408 cache->full_stripe_len + cache->key.objectid;
409 return ret;
410}
411
412/*
413 * Lock a full stripe to avoid concurrency of recovery and read
414 *
415 * It's only used for profiles with parities (RAID5/6), for other profiles it
416 * does nothing.
417 *
418 * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
419 * So caller must call unlock_full_stripe() at the same context.
420 *
421 * Return <0 if encounters error.
422 */
423static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
424 bool *locked_ret)
425{
426 struct btrfs_block_group_cache *bg_cache;
427 struct btrfs_full_stripe_locks_tree *locks_root;
428 struct full_stripe_lock *existing;
429 u64 fstripe_start;
430 int ret = 0;
431
432 *locked_ret = false;
433 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
434 if (!bg_cache) {
435 ASSERT(0);
436 return -ENOENT;
437 }
438
439 /* Profiles not based on parity don't need full stripe lock */
440 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
441 goto out;
442 locks_root = &bg_cache->full_stripe_locks_root;
443
444 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
445
446 /* Now insert the full stripe lock */
447 mutex_lock(&locks_root->lock);
448 existing = insert_full_stripe_lock(locks_root, fstripe_start);
449 mutex_unlock(&locks_root->lock);
450 if (IS_ERR(existing)) {
451 ret = PTR_ERR(existing);
452 goto out;
453 }
454 mutex_lock(&existing->mutex);
455 *locked_ret = true;
456out:
457 btrfs_put_block_group(bg_cache);
458 return ret;
459}
460
461/*
462 * Unlock a full stripe.
463 *
464 * NOTE: Caller must ensure it's the same context calling corresponding
465 * lock_full_stripe().
466 *
467 * Return 0 if we unlock full stripe without problem.
468 * Return <0 for error
469 */
470static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
471 bool locked)
472{
473 struct btrfs_block_group_cache *bg_cache;
474 struct btrfs_full_stripe_locks_tree *locks_root;
475 struct full_stripe_lock *fstripe_lock;
476 u64 fstripe_start;
477 bool freeit = false;
478 int ret = 0;
479
480 /* If we didn't acquire full stripe lock, no need to continue */
481 if (!locked)
482 return 0;
483
484 bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
485 if (!bg_cache) {
486 ASSERT(0);
487 return -ENOENT;
488 }
489 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
490 goto out;
491
492 locks_root = &bg_cache->full_stripe_locks_root;
493 fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
494
495 mutex_lock(&locks_root->lock);
496 fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
497 /* Unpaired unlock_full_stripe() detected */
498 if (!fstripe_lock) {
499 WARN_ON(1);
500 ret = -ENOENT;
501 mutex_unlock(&locks_root->lock);
502 goto out;
503 }
504
505 if (fstripe_lock->refs == 0) {
506 WARN_ON(1);
507 btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
508 fstripe_lock->logical);
509 } else {
510 fstripe_lock->refs--;
511 }
512
513 if (fstripe_lock->refs == 0) {
514 rb_erase(&fstripe_lock->node, &locks_root->root);
515 freeit = true;
516 }
517 mutex_unlock(&locks_root->lock);
518
519 mutex_unlock(&fstripe_lock->mutex);
520 if (freeit)
521 kfree(fstripe_lock);
522out:
523 btrfs_put_block_group(bg_cache);
524 return ret;
525}
526
527static void scrub_free_csums(struct scrub_ctx *sctx)
528{
529 while (!list_empty(&sctx->csum_list)) {
530 struct btrfs_ordered_sum *sum;
531 sum = list_first_entry(&sctx->csum_list,
532 struct btrfs_ordered_sum, list);
533 list_del(&sum->list);
534 kfree(sum);
535 }
536}
537
538static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
539{
540 int i;
541
542 if (!sctx)
543 return;
544
545 /* this can happen when scrub is cancelled */
546 if (sctx->curr != -1) {
547 struct scrub_bio *sbio = sctx->bios[sctx->curr];
548
549 for (i = 0; i < sbio->page_count; i++) {
550 WARN_ON(!sbio->pagev[i]->page);
551 scrub_block_put(sbio->pagev[i]->sblock);
552 }
553 bio_put(sbio->bio);
554 }
555
556 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
557 struct scrub_bio *sbio = sctx->bios[i];
558
559 if (!sbio)
560 break;
561 kfree(sbio);
562 }
563
564 kfree(sctx->wr_curr_bio);
565 scrub_free_csums(sctx);
566 kfree(sctx);
567}
568
569static void scrub_put_ctx(struct scrub_ctx *sctx)
570{
571 if (refcount_dec_and_test(&sctx->refs))
572 scrub_free_ctx(sctx);
573}
574
575static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
576 struct btrfs_fs_info *fs_info, int is_dev_replace)
577{
578 struct scrub_ctx *sctx;
579 int i;
580
581 sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
582 if (!sctx)
583 goto nomem;
584 refcount_set(&sctx->refs, 1);
585 sctx->is_dev_replace = is_dev_replace;
586 sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
587 sctx->curr = -1;
588 sctx->fs_info = fs_info;
589 INIT_LIST_HEAD(&sctx->csum_list);
590 for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
591 struct scrub_bio *sbio;
592
593 sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
594 if (!sbio)
595 goto nomem;
596 sctx->bios[i] = sbio;
597
598 sbio->index = i;
599 sbio->sctx = sctx;
600 sbio->page_count = 0;
601 btrfs_init_work(&sbio->work, btrfs_scrub_helper,
602 scrub_bio_end_io_worker, NULL, NULL);
603
604 if (i != SCRUB_BIOS_PER_SCTX - 1)
605 sctx->bios[i]->next_free = i + 1;
606 else
607 sctx->bios[i]->next_free = -1;
608 }
609 sctx->first_free = 0;
610 atomic_set(&sctx->bios_in_flight, 0);
611 atomic_set(&sctx->workers_pending, 0);
612 atomic_set(&sctx->cancel_req, 0);
613 sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
614
615 spin_lock_init(&sctx->list_lock);
616 spin_lock_init(&sctx->stat_lock);
617 init_waitqueue_head(&sctx->list_wait);
618
619 WARN_ON(sctx->wr_curr_bio != NULL);
620 mutex_init(&sctx->wr_lock);
621 sctx->wr_curr_bio = NULL;
622 if (is_dev_replace) {
623 WARN_ON(!fs_info->dev_replace.tgtdev);
624 sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
625 sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
626 sctx->flush_all_writes = false;
627 }
628
629 return sctx;
630
631nomem:
632 scrub_free_ctx(sctx);
633 return ERR_PTR(-ENOMEM);
634}
635
636static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
637 void *warn_ctx)
638{
639 u64 isize;
640 u32 nlink;
641 int ret;
642 int i;
643 unsigned nofs_flag;
644 struct extent_buffer *eb;
645 struct btrfs_inode_item *inode_item;
646 struct scrub_warning *swarn = warn_ctx;
647 struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
648 struct inode_fs_paths *ipath = NULL;
649 struct btrfs_root *local_root;
650 struct btrfs_key root_key;
651 struct btrfs_key key;
652
653 root_key.objectid = root;
654 root_key.type = BTRFS_ROOT_ITEM_KEY;
655 root_key.offset = (u64)-1;
656 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
657 if (IS_ERR(local_root)) {
658 ret = PTR_ERR(local_root);
659 goto err;
660 }
661
662 /*
663 * this makes the path point to (inum INODE_ITEM ioff)
664 */
665 key.objectid = inum;
666 key.type = BTRFS_INODE_ITEM_KEY;
667 key.offset = 0;
668
669 ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
670 if (ret) {
671 btrfs_release_path(swarn->path);
672 goto err;
673 }
674
675 eb = swarn->path->nodes[0];
676 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
677 struct btrfs_inode_item);
678 isize = btrfs_inode_size(eb, inode_item);
679 nlink = btrfs_inode_nlink(eb, inode_item);
680 btrfs_release_path(swarn->path);
681
682 /*
683 * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
684 * uses GFP_NOFS in this context, so we keep it consistent but it does
685 * not seem to be strictly necessary.
686 */
687 nofs_flag = memalloc_nofs_save();
688 ipath = init_ipath(4096, local_root, swarn->path);
689 memalloc_nofs_restore(nofs_flag);
690 if (IS_ERR(ipath)) {
691 ret = PTR_ERR(ipath);
692 ipath = NULL;
693 goto err;
694 }
695 ret = paths_from_inode(inum, ipath);
696
697 if (ret < 0)
698 goto err;
699
700 /*
701 * we deliberately ignore the bit ipath might have been too small to
702 * hold all of the paths here
703 */
704 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
705 btrfs_warn_in_rcu(fs_info,
706"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
707 swarn->errstr, swarn->logical,
708 rcu_str_deref(swarn->dev->name),
709 swarn->physical,
710 root, inum, offset,
711 min(isize - offset, (u64)PAGE_SIZE), nlink,
712 (char *)(unsigned long)ipath->fspath->val[i]);
713
714 free_ipath(ipath);
715 return 0;
716
717err:
718 btrfs_warn_in_rcu(fs_info,
719 "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
720 swarn->errstr, swarn->logical,
721 rcu_str_deref(swarn->dev->name),
722 swarn->physical,
723 root, inum, offset, ret);
724
725 free_ipath(ipath);
726 return 0;
727}
728
729static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
730{
731 struct btrfs_device *dev;
732 struct btrfs_fs_info *fs_info;
733 struct btrfs_path *path;
734 struct btrfs_key found_key;
735 struct extent_buffer *eb;
736 struct btrfs_extent_item *ei;
737 struct scrub_warning swarn;
738 unsigned long ptr = 0;
739 u64 extent_item_pos;
740 u64 flags = 0;
741 u64 ref_root;
742 u32 item_size;
743 u8 ref_level = 0;
744 int ret;
745
746 WARN_ON(sblock->page_count < 1);
747 dev = sblock->pagev[0]->dev;
748 fs_info = sblock->sctx->fs_info;
749
750 path = btrfs_alloc_path();
751 if (!path)
752 return;
753
754 swarn.physical = sblock->pagev[0]->physical;
755 swarn.logical = sblock->pagev[0]->logical;
756 swarn.errstr = errstr;
757 swarn.dev = NULL;
758
759 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
760 &flags);
761 if (ret < 0)
762 goto out;
763
764 extent_item_pos = swarn.logical - found_key.objectid;
765 swarn.extent_item_size = found_key.offset;
766
767 eb = path->nodes[0];
768 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
769 item_size = btrfs_item_size_nr(eb, path->slots[0]);
770
771 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
772 do {
773 ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
774 item_size, &ref_root,
775 &ref_level);
776 btrfs_warn_in_rcu(fs_info,
777"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
778 errstr, swarn.logical,
779 rcu_str_deref(dev->name),
780 swarn.physical,
781 ref_level ? "node" : "leaf",
782 ret < 0 ? -1 : ref_level,
783 ret < 0 ? -1 : ref_root);
784 } while (ret != 1);
785 btrfs_release_path(path);
786 } else {
787 btrfs_release_path(path);
788 swarn.path = path;
789 swarn.dev = dev;
790 iterate_extent_inodes(fs_info, found_key.objectid,
791 extent_item_pos, 1,
792 scrub_print_warning_inode, &swarn, false);
793 }
794
795out:
796 btrfs_free_path(path);
797}
798
799static inline void scrub_get_recover(struct scrub_recover *recover)
800{
801 refcount_inc(&recover->refs);
802}
803
804static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
805 struct scrub_recover *recover)
806{
807 if (refcount_dec_and_test(&recover->refs)) {
808 btrfs_bio_counter_dec(fs_info);
809 btrfs_put_bbio(recover->bbio);
810 kfree(recover);
811 }
812}
813
814/*
815 * scrub_handle_errored_block gets called when either verification of the
816 * pages failed or the bio failed to read, e.g. with EIO. In the latter
817 * case, this function handles all pages in the bio, even though only one
818 * may be bad.
819 * The goal of this function is to repair the errored block by using the
820 * contents of one of the mirrors.
821 */
822static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
823{
824 struct scrub_ctx *sctx = sblock_to_check->sctx;
825 struct btrfs_device *dev;
826 struct btrfs_fs_info *fs_info;
827 u64 logical;
828 unsigned int failed_mirror_index;
829 unsigned int is_metadata;
830 unsigned int have_csum;
831 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
832 struct scrub_block *sblock_bad;
833 int ret;
834 int mirror_index;
835 int page_num;
836 int success;
837 bool full_stripe_locked;
838 unsigned int nofs_flag;
839 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
840 DEFAULT_RATELIMIT_BURST);
841
842 BUG_ON(sblock_to_check->page_count < 1);
843 fs_info = sctx->fs_info;
844 if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
845 /*
846 * if we find an error in a super block, we just report it.
847 * They will get written with the next transaction commit
848 * anyway
849 */
850 spin_lock(&sctx->stat_lock);
851 ++sctx->stat.super_errors;
852 spin_unlock(&sctx->stat_lock);
853 return 0;
854 }
855 logical = sblock_to_check->pagev[0]->logical;
856 BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
857 failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
858 is_metadata = !(sblock_to_check->pagev[0]->flags &
859 BTRFS_EXTENT_FLAG_DATA);
860 have_csum = sblock_to_check->pagev[0]->have_csum;
861 dev = sblock_to_check->pagev[0]->dev;
862
863 /*
864 * We must use GFP_NOFS because the scrub task might be waiting for a
865 * worker task executing this function and in turn a transaction commit
866 * might be waiting the scrub task to pause (which needs to wait for all
867 * the worker tasks to complete before pausing).
868 * We do allocations in the workers through insert_full_stripe_lock()
869 * and scrub_add_page_to_wr_bio(), which happens down the call chain of
870 * this function.
871 */
872 nofs_flag = memalloc_nofs_save();
873 /*
874 * For RAID5/6, race can happen for a different device scrub thread.
875 * For data corruption, Parity and Data threads will both try
876 * to recovery the data.
877 * Race can lead to doubly added csum error, or even unrecoverable
878 * error.
879 */
880 ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
881 if (ret < 0) {
882 memalloc_nofs_restore(nofs_flag);
883 spin_lock(&sctx->stat_lock);
884 if (ret == -ENOMEM)
885 sctx->stat.malloc_errors++;
886 sctx->stat.read_errors++;
887 sctx->stat.uncorrectable_errors++;
888 spin_unlock(&sctx->stat_lock);
889 return ret;
890 }
891
892 /*
893 * read all mirrors one after the other. This includes to
894 * re-read the extent or metadata block that failed (that was
895 * the cause that this fixup code is called) another time,
896 * page by page this time in order to know which pages
897 * caused I/O errors and which ones are good (for all mirrors).
898 * It is the goal to handle the situation when more than one
899 * mirror contains I/O errors, but the errors do not
900 * overlap, i.e. the data can be repaired by selecting the
901 * pages from those mirrors without I/O error on the
902 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
903 * would be that mirror #1 has an I/O error on the first page,
904 * the second page is good, and mirror #2 has an I/O error on
905 * the second page, but the first page is good.
906 * Then the first page of the first mirror can be repaired by
907 * taking the first page of the second mirror, and the
908 * second page of the second mirror can be repaired by
909 * copying the contents of the 2nd page of the 1st mirror.
910 * One more note: if the pages of one mirror contain I/O
911 * errors, the checksum cannot be verified. In order to get
912 * the best data for repairing, the first attempt is to find
913 * a mirror without I/O errors and with a validated checksum.
914 * Only if this is not possible, the pages are picked from
915 * mirrors with I/O errors without considering the checksum.
916 * If the latter is the case, at the end, the checksum of the
917 * repaired area is verified in order to correctly maintain
918 * the statistics.
919 */
920
921 sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
922 sizeof(*sblocks_for_recheck), GFP_KERNEL);
923 if (!sblocks_for_recheck) {
924 spin_lock(&sctx->stat_lock);
925 sctx->stat.malloc_errors++;
926 sctx->stat.read_errors++;
927 sctx->stat.uncorrectable_errors++;
928 spin_unlock(&sctx->stat_lock);
929 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
930 goto out;
931 }
932
933 /* setup the context, map the logical blocks and alloc the pages */
934 ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
935 if (ret) {
936 spin_lock(&sctx->stat_lock);
937 sctx->stat.read_errors++;
938 sctx->stat.uncorrectable_errors++;
939 spin_unlock(&sctx->stat_lock);
940 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
941 goto out;
942 }
943 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
944 sblock_bad = sblocks_for_recheck + failed_mirror_index;
945
946 /* build and submit the bios for the failed mirror, check checksums */
947 scrub_recheck_block(fs_info, sblock_bad, 1);
948
949 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
950 sblock_bad->no_io_error_seen) {
951 /*
952 * the error disappeared after reading page by page, or
953 * the area was part of a huge bio and other parts of the
954 * bio caused I/O errors, or the block layer merged several
955 * read requests into one and the error is caused by a
956 * different bio (usually one of the two latter cases is
957 * the cause)
958 */
959 spin_lock(&sctx->stat_lock);
960 sctx->stat.unverified_errors++;
961 sblock_to_check->data_corrected = 1;
962 spin_unlock(&sctx->stat_lock);
963
964 if (sctx->is_dev_replace)
965 scrub_write_block_to_dev_replace(sblock_bad);
966 goto out;
967 }
968
969 if (!sblock_bad->no_io_error_seen) {
970 spin_lock(&sctx->stat_lock);
971 sctx->stat.read_errors++;
972 spin_unlock(&sctx->stat_lock);
973 if (__ratelimit(&_rs))
974 scrub_print_warning("i/o error", sblock_to_check);
975 btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
976 } else if (sblock_bad->checksum_error) {
977 spin_lock(&sctx->stat_lock);
978 sctx->stat.csum_errors++;
979 spin_unlock(&sctx->stat_lock);
980 if (__ratelimit(&_rs))
981 scrub_print_warning("checksum error", sblock_to_check);
982 btrfs_dev_stat_inc_and_print(dev,
983 BTRFS_DEV_STAT_CORRUPTION_ERRS);
984 } else if (sblock_bad->header_error) {
985 spin_lock(&sctx->stat_lock);
986 sctx->stat.verify_errors++;
987 spin_unlock(&sctx->stat_lock);
988 if (__ratelimit(&_rs))
989 scrub_print_warning("checksum/header error",
990 sblock_to_check);
991 if (sblock_bad->generation_error)
992 btrfs_dev_stat_inc_and_print(dev,
993 BTRFS_DEV_STAT_GENERATION_ERRS);
994 else
995 btrfs_dev_stat_inc_and_print(dev,
996 BTRFS_DEV_STAT_CORRUPTION_ERRS);
997 }
998
999 if (sctx->readonly) {
1000 ASSERT(!sctx->is_dev_replace);
1001 goto out;
1002 }
1003
1004 /*
1005 * now build and submit the bios for the other mirrors, check
1006 * checksums.
1007 * First try to pick the mirror which is completely without I/O
1008 * errors and also does not have a checksum error.
1009 * If one is found, and if a checksum is present, the full block
1010 * that is known to contain an error is rewritten. Afterwards
1011 * the block is known to be corrected.
1012 * If a mirror is found which is completely correct, and no
1013 * checksum is present, only those pages are rewritten that had
1014 * an I/O error in the block to be repaired, since it cannot be
1015 * determined, which copy of the other pages is better (and it
1016 * could happen otherwise that a correct page would be
1017 * overwritten by a bad one).
1018 */
1019 for (mirror_index = 0; ;mirror_index++) {
1020 struct scrub_block *sblock_other;
1021
1022 if (mirror_index == failed_mirror_index)
1023 continue;
1024
1025 /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
1026 if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1027 if (mirror_index >= BTRFS_MAX_MIRRORS)
1028 break;
1029 if (!sblocks_for_recheck[mirror_index].page_count)
1030 break;
1031
1032 sblock_other = sblocks_for_recheck + mirror_index;
1033 } else {
1034 struct scrub_recover *r = sblock_bad->pagev[0]->recover;
1035 int max_allowed = r->bbio->num_stripes -
1036 r->bbio->num_tgtdevs;
1037
1038 if (mirror_index >= max_allowed)
1039 break;
1040 if (!sblocks_for_recheck[1].page_count)
1041 break;
1042
1043 ASSERT(failed_mirror_index == 0);
1044 sblock_other = sblocks_for_recheck + 1;
1045 sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
1046 }
1047
1048 /* build and submit the bios, check checksums */
1049 scrub_recheck_block(fs_info, sblock_other, 0);
1050
1051 if (!sblock_other->header_error &&
1052 !sblock_other->checksum_error &&
1053 sblock_other->no_io_error_seen) {
1054 if (sctx->is_dev_replace) {
1055 scrub_write_block_to_dev_replace(sblock_other);
1056 goto corrected_error;
1057 } else {
1058 ret = scrub_repair_block_from_good_copy(
1059 sblock_bad, sblock_other);
1060 if (!ret)
1061 goto corrected_error;
1062 }
1063 }
1064 }
1065
1066 if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
1067 goto did_not_correct_error;
1068
1069 /*
1070 * In case of I/O errors in the area that is supposed to be
1071 * repaired, continue by picking good copies of those pages.
1072 * Select the good pages from mirrors to rewrite bad pages from
1073 * the area to fix. Afterwards verify the checksum of the block
1074 * that is supposed to be repaired. This verification step is
1075 * only done for the purpose of statistic counting and for the
1076 * final scrub report, whether errors remain.
1077 * A perfect algorithm could make use of the checksum and try
1078 * all possible combinations of pages from the different mirrors
1079 * until the checksum verification succeeds. For example, when
1080 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
1081 * of mirror #2 is readable but the final checksum test fails,
1082 * then the 2nd page of mirror #3 could be tried, whether now
1083 * the final checksum succeeds. But this would be a rare
1084 * exception and is therefore not implemented. At least it is
1085 * avoided that the good copy is overwritten.
1086 * A more useful improvement would be to pick the sectors
1087 * without I/O error based on sector sizes (512 bytes on legacy
1088 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
1089 * mirror could be repaired by taking 512 byte of a different
1090 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
1091 * area are unreadable.
1092 */
1093 success = 1;
1094 for (page_num = 0; page_num < sblock_bad->page_count;
1095 page_num++) {
1096 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1097 struct scrub_block *sblock_other = NULL;
1098
1099 /* skip no-io-error page in scrub */
1100 if (!page_bad->io_error && !sctx->is_dev_replace)
1101 continue;
1102
1103 if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
1104 /*
1105 * In case of dev replace, if raid56 rebuild process
1106 * didn't work out correct data, then copy the content
1107 * in sblock_bad to make sure target device is identical
1108 * to source device, instead of writing garbage data in
1109 * sblock_for_recheck array to target device.
1110 */
1111 sblock_other = NULL;
1112 } else if (page_bad->io_error) {
1113 /* try to find no-io-error page in mirrors */
1114 for (mirror_index = 0;
1115 mirror_index < BTRFS_MAX_MIRRORS &&
1116 sblocks_for_recheck[mirror_index].page_count > 0;
1117 mirror_index++) {
1118 if (!sblocks_for_recheck[mirror_index].
1119 pagev[page_num]->io_error) {
1120 sblock_other = sblocks_for_recheck +
1121 mirror_index;
1122 break;
1123 }
1124 }
1125 if (!sblock_other)
1126 success = 0;
1127 }
1128
1129 if (sctx->is_dev_replace) {
1130 /*
1131 * did not find a mirror to fetch the page
1132 * from. scrub_write_page_to_dev_replace()
1133 * handles this case (page->io_error), by
1134 * filling the block with zeros before
1135 * submitting the write request
1136 */
1137 if (!sblock_other)
1138 sblock_other = sblock_bad;
1139
1140 if (scrub_write_page_to_dev_replace(sblock_other,
1141 page_num) != 0) {
1142 atomic64_inc(
1143 &fs_info->dev_replace.num_write_errors);
1144 success = 0;
1145 }
1146 } else if (sblock_other) {
1147 ret = scrub_repair_page_from_good_copy(sblock_bad,
1148 sblock_other,
1149 page_num, 0);
1150 if (0 == ret)
1151 page_bad->io_error = 0;
1152 else
1153 success = 0;
1154 }
1155 }
1156
1157 if (success && !sctx->is_dev_replace) {
1158 if (is_metadata || have_csum) {
1159 /*
1160 * need to verify the checksum now that all
1161 * sectors on disk are repaired (the write
1162 * request for data to be repaired is on its way).
1163 * Just be lazy and use scrub_recheck_block()
1164 * which re-reads the data before the checksum
1165 * is verified, but most likely the data comes out
1166 * of the page cache.
1167 */
1168 scrub_recheck_block(fs_info, sblock_bad, 1);
1169 if (!sblock_bad->header_error &&
1170 !sblock_bad->checksum_error &&
1171 sblock_bad->no_io_error_seen)
1172 goto corrected_error;
1173 else
1174 goto did_not_correct_error;
1175 } else {
1176corrected_error:
1177 spin_lock(&sctx->stat_lock);
1178 sctx->stat.corrected_errors++;
1179 sblock_to_check->data_corrected = 1;
1180 spin_unlock(&sctx->stat_lock);
1181 btrfs_err_rl_in_rcu(fs_info,
1182 "fixed up error at logical %llu on dev %s",
1183 logical, rcu_str_deref(dev->name));
1184 }
1185 } else {
1186did_not_correct_error:
1187 spin_lock(&sctx->stat_lock);
1188 sctx->stat.uncorrectable_errors++;
1189 spin_unlock(&sctx->stat_lock);
1190 btrfs_err_rl_in_rcu(fs_info,
1191 "unable to fixup (regular) error at logical %llu on dev %s",
1192 logical, rcu_str_deref(dev->name));
1193 }
1194
1195out:
1196 if (sblocks_for_recheck) {
1197 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
1198 mirror_index++) {
1199 struct scrub_block *sblock = sblocks_for_recheck +
1200 mirror_index;
1201 struct scrub_recover *recover;
1202 int page_index;
1203
1204 for (page_index = 0; page_index < sblock->page_count;
1205 page_index++) {
1206 sblock->pagev[page_index]->sblock = NULL;
1207 recover = sblock->pagev[page_index]->recover;
1208 if (recover) {
1209 scrub_put_recover(fs_info, recover);
1210 sblock->pagev[page_index]->recover =
1211 NULL;
1212 }
1213 scrub_page_put(sblock->pagev[page_index]);
1214 }
1215 }
1216 kfree(sblocks_for_recheck);
1217 }
1218
1219 ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
1220 memalloc_nofs_restore(nofs_flag);
1221 if (ret < 0)
1222 return ret;
1223 return 0;
1224}
1225
1226static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
1227{
1228 if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
1229 return 2;
1230 else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
1231 return 3;
1232 else
1233 return (int)bbio->num_stripes;
1234}
1235
1236static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
1237 u64 *raid_map,
1238 u64 mapped_length,
1239 int nstripes, int mirror,
1240 int *stripe_index,
1241 u64 *stripe_offset)
1242{
1243 int i;
1244
1245 if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1246 /* RAID5/6 */
1247 for (i = 0; i < nstripes; i++) {
1248 if (raid_map[i] == RAID6_Q_STRIPE ||
1249 raid_map[i] == RAID5_P_STRIPE)
1250 continue;
1251
1252 if (logical >= raid_map[i] &&
1253 logical < raid_map[i] + mapped_length)
1254 break;
1255 }
1256
1257 *stripe_index = i;
1258 *stripe_offset = logical - raid_map[i];
1259 } else {
1260 /* The other RAID type */
1261 *stripe_index = mirror;
1262 *stripe_offset = 0;
1263 }
1264}
1265
1266static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
1267 struct scrub_block *sblocks_for_recheck)
1268{
1269 struct scrub_ctx *sctx = original_sblock->sctx;
1270 struct btrfs_fs_info *fs_info = sctx->fs_info;
1271 u64 length = original_sblock->page_count * PAGE_SIZE;
1272 u64 logical = original_sblock->pagev[0]->logical;
1273 u64 generation = original_sblock->pagev[0]->generation;
1274 u64 flags = original_sblock->pagev[0]->flags;
1275 u64 have_csum = original_sblock->pagev[0]->have_csum;
1276 struct scrub_recover *recover;
1277 struct btrfs_bio *bbio;
1278 u64 sublen;
1279 u64 mapped_length;
1280 u64 stripe_offset;
1281 int stripe_index;
1282 int page_index = 0;
1283 int mirror_index;
1284 int nmirrors;
1285 int ret;
1286
1287 /*
1288 * note: the two members refs and outstanding_pages
1289 * are not used (and not set) in the blocks that are used for
1290 * the recheck procedure
1291 */
1292
1293 while (length > 0) {
1294 sublen = min_t(u64, length, PAGE_SIZE);
1295 mapped_length = sublen;
1296 bbio = NULL;
1297
1298 /*
1299 * with a length of PAGE_SIZE, each returned stripe
1300 * represents one mirror
1301 */
1302 btrfs_bio_counter_inc_blocked(fs_info);
1303 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
1304 logical, &mapped_length, &bbio);
1305 if (ret || !bbio || mapped_length < sublen) {
1306 btrfs_put_bbio(bbio);
1307 btrfs_bio_counter_dec(fs_info);
1308 return -EIO;
1309 }
1310
1311 recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
1312 if (!recover) {
1313 btrfs_put_bbio(bbio);
1314 btrfs_bio_counter_dec(fs_info);
1315 return -ENOMEM;
1316 }
1317
1318 refcount_set(&recover->refs, 1);
1319 recover->bbio = bbio;
1320 recover->map_length = mapped_length;
1321
1322 BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
1323
1324 nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
1325
1326 for (mirror_index = 0; mirror_index < nmirrors;
1327 mirror_index++) {
1328 struct scrub_block *sblock;
1329 struct scrub_page *page;
1330
1331 sblock = sblocks_for_recheck + mirror_index;
1332 sblock->sctx = sctx;
1333
1334 page = kzalloc(sizeof(*page), GFP_NOFS);
1335 if (!page) {
1336leave_nomem:
1337 spin_lock(&sctx->stat_lock);
1338 sctx->stat.malloc_errors++;
1339 spin_unlock(&sctx->stat_lock);
1340 scrub_put_recover(fs_info, recover);
1341 return -ENOMEM;
1342 }
1343 scrub_page_get(page);
1344 sblock->pagev[page_index] = page;
1345 page->sblock = sblock;
1346 page->flags = flags;
1347 page->generation = generation;
1348 page->logical = logical;
1349 page->have_csum = have_csum;
1350 if (have_csum)
1351 memcpy(page->csum,
1352 original_sblock->pagev[0]->csum,
1353 sctx->csum_size);
1354
1355 scrub_stripe_index_and_offset(logical,
1356 bbio->map_type,
1357 bbio->raid_map,
1358 mapped_length,
1359 bbio->num_stripes -
1360 bbio->num_tgtdevs,
1361 mirror_index,
1362 &stripe_index,
1363 &stripe_offset);
1364 page->physical = bbio->stripes[stripe_index].physical +
1365 stripe_offset;
1366 page->dev = bbio->stripes[stripe_index].dev;
1367
1368 BUG_ON(page_index >= original_sblock->page_count);
1369 page->physical_for_dev_replace =
1370 original_sblock->pagev[page_index]->
1371 physical_for_dev_replace;
1372 /* for missing devices, dev->bdev is NULL */
1373 page->mirror_num = mirror_index + 1;
1374 sblock->page_count++;
1375 page->page = alloc_page(GFP_NOFS);
1376 if (!page->page)
1377 goto leave_nomem;
1378
1379 scrub_get_recover(recover);
1380 page->recover = recover;
1381 }
1382 scrub_put_recover(fs_info, recover);
1383 length -= sublen;
1384 logical += sublen;
1385 page_index++;
1386 }
1387
1388 return 0;
1389}
1390
1391static void scrub_bio_wait_endio(struct bio *bio)
1392{
1393 complete(bio->bi_private);
1394}
1395
1396static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
1397 struct bio *bio,
1398 struct scrub_page *page)
1399{
1400 DECLARE_COMPLETION_ONSTACK(done);
1401 int ret;
1402 int mirror_num;
1403
1404 bio->bi_iter.bi_sector = page->logical >> 9;
1405 bio->bi_private = &done;
1406 bio->bi_end_io = scrub_bio_wait_endio;
1407
1408 mirror_num = page->sblock->pagev[0]->mirror_num;
1409 ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
1410 page->recover->map_length,
1411 mirror_num, 0);
1412 if (ret)
1413 return ret;
1414
1415 wait_for_completion_io(&done);
1416 return blk_status_to_errno(bio->bi_status);
1417}
1418
1419static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
1420 struct scrub_block *sblock)
1421{
1422 struct scrub_page *first_page = sblock->pagev[0];
1423 struct bio *bio;
1424 int page_num;
1425
1426 /* All pages in sblock belong to the same stripe on the same device. */
1427 ASSERT(first_page->dev);
1428 if (!first_page->dev->bdev)
1429 goto out;
1430
1431 bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
1432 bio_set_dev(bio, first_page->dev->bdev);
1433
1434 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1435 struct scrub_page *page = sblock->pagev[page_num];
1436
1437 WARN_ON(!page->page);
1438 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1439 }
1440
1441 if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
1442 bio_put(bio);
1443 goto out;
1444 }
1445
1446 bio_put(bio);
1447
1448 scrub_recheck_block_checksum(sblock);
1449
1450 return;
1451out:
1452 for (page_num = 0; page_num < sblock->page_count; page_num++)
1453 sblock->pagev[page_num]->io_error = 1;
1454
1455 sblock->no_io_error_seen = 0;
1456}
1457
1458/*
1459 * this function will check the on disk data for checksum errors, header
1460 * errors and read I/O errors. If any I/O errors happen, the exact pages
1461 * which are errored are marked as being bad. The goal is to enable scrub
1462 * to take those pages that are not errored from all the mirrors so that
1463 * the pages that are errored in the just handled mirror can be repaired.
1464 */
1465static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
1466 struct scrub_block *sblock,
1467 int retry_failed_mirror)
1468{
1469 int page_num;
1470
1471 sblock->no_io_error_seen = 1;
1472
1473 /* short cut for raid56 */
1474 if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
1475 return scrub_recheck_block_on_raid56(fs_info, sblock);
1476
1477 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1478 struct bio *bio;
1479 struct scrub_page *page = sblock->pagev[page_num];
1480
1481 if (page->dev->bdev == NULL) {
1482 page->io_error = 1;
1483 sblock->no_io_error_seen = 0;
1484 continue;
1485 }
1486
1487 WARN_ON(!page->page);
1488 bio = btrfs_io_bio_alloc(1);
1489 bio_set_dev(bio, page->dev->bdev);
1490
1491 bio_add_page(bio, page->page, PAGE_SIZE, 0);
1492 bio->bi_iter.bi_sector = page->physical >> 9;
1493 bio->bi_opf = REQ_OP_READ;
1494
1495 if (btrfsic_submit_bio_wait(bio)) {
1496 page->io_error = 1;
1497 sblock->no_io_error_seen = 0;
1498 }
1499
1500 bio_put(bio);
1501 }
1502
1503 if (sblock->no_io_error_seen)
1504 scrub_recheck_block_checksum(sblock);
1505}
1506
1507static inline int scrub_check_fsid(u8 fsid[],
1508 struct scrub_page *spage)
1509{
1510 struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
1511 int ret;
1512
1513 ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1514 return !ret;
1515}
1516
1517static void scrub_recheck_block_checksum(struct scrub_block *sblock)
1518{
1519 sblock->header_error = 0;
1520 sblock->checksum_error = 0;
1521 sblock->generation_error = 0;
1522
1523 if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
1524 scrub_checksum_data(sblock);
1525 else
1526 scrub_checksum_tree_block(sblock);
1527}
1528
1529static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1530 struct scrub_block *sblock_good)
1531{
1532 int page_num;
1533 int ret = 0;
1534
1535 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1536 int ret_sub;
1537
1538 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1539 sblock_good,
1540 page_num, 1);
1541 if (ret_sub)
1542 ret = ret_sub;
1543 }
1544
1545 return ret;
1546}
1547
1548static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1549 struct scrub_block *sblock_good,
1550 int page_num, int force_write)
1551{
1552 struct scrub_page *page_bad = sblock_bad->pagev[page_num];
1553 struct scrub_page *page_good = sblock_good->pagev[page_num];
1554 struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
1555
1556 BUG_ON(page_bad->page == NULL);
1557 BUG_ON(page_good->page == NULL);
1558 if (force_write || sblock_bad->header_error ||
1559 sblock_bad->checksum_error || page_bad->io_error) {
1560 struct bio *bio;
1561 int ret;
1562
1563 if (!page_bad->dev->bdev) {
1564 btrfs_warn_rl(fs_info,
1565 "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
1566 return -EIO;
1567 }
1568
1569 bio = btrfs_io_bio_alloc(1);
1570 bio_set_dev(bio, page_bad->dev->bdev);
1571 bio->bi_iter.bi_sector = page_bad->physical >> 9;
1572 bio->bi_opf = REQ_OP_WRITE;
1573
1574 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1575 if (PAGE_SIZE != ret) {
1576 bio_put(bio);
1577 return -EIO;
1578 }
1579
1580 if (btrfsic_submit_bio_wait(bio)) {
1581 btrfs_dev_stat_inc_and_print(page_bad->dev,
1582 BTRFS_DEV_STAT_WRITE_ERRS);
1583 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1584 bio_put(bio);
1585 return -EIO;
1586 }
1587 bio_put(bio);
1588 }
1589
1590 return 0;
1591}
1592
1593static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
1594{
1595 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
1596 int page_num;
1597
1598 /*
1599 * This block is used for the check of the parity on the source device,
1600 * so the data needn't be written into the destination device.
1601 */
1602 if (sblock->sparity)
1603 return;
1604
1605 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1606 int ret;
1607
1608 ret = scrub_write_page_to_dev_replace(sblock, page_num);
1609 if (ret)
1610 atomic64_inc(&fs_info->dev_replace.num_write_errors);
1611 }
1612}
1613
1614static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
1615 int page_num)
1616{
1617 struct scrub_page *spage = sblock->pagev[page_num];
1618
1619 BUG_ON(spage->page == NULL);
1620 if (spage->io_error) {
1621 void *mapped_buffer = kmap_atomic(spage->page);
1622
1623 clear_page(mapped_buffer);
1624 flush_dcache_page(spage->page);
1625 kunmap_atomic(mapped_buffer);
1626 }
1627 return scrub_add_page_to_wr_bio(sblock->sctx, spage);
1628}
1629
1630static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
1631 struct scrub_page *spage)
1632{
1633 struct scrub_bio *sbio;
1634 int ret;
1635
1636 mutex_lock(&sctx->wr_lock);
1637again:
1638 if (!sctx->wr_curr_bio) {
1639 sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
1640 GFP_KERNEL);
1641 if (!sctx->wr_curr_bio) {
1642 mutex_unlock(&sctx->wr_lock);
1643 return -ENOMEM;
1644 }
1645 sctx->wr_curr_bio->sctx = sctx;
1646 sctx->wr_curr_bio->page_count = 0;
1647 }
1648 sbio = sctx->wr_curr_bio;
1649 if (sbio->page_count == 0) {
1650 struct bio *bio;
1651
1652 sbio->physical = spage->physical_for_dev_replace;
1653 sbio->logical = spage->logical;
1654 sbio->dev = sctx->wr_tgtdev;
1655 bio = sbio->bio;
1656 if (!bio) {
1657 bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
1658 sbio->bio = bio;
1659 }
1660
1661 bio->bi_private = sbio;
1662 bio->bi_end_io = scrub_wr_bio_end_io;
1663 bio_set_dev(bio, sbio->dev->bdev);
1664 bio->bi_iter.bi_sector = sbio->physical >> 9;
1665 bio->bi_opf = REQ_OP_WRITE;
1666 sbio->status = 0;
1667 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1668 spage->physical_for_dev_replace ||
1669 sbio->logical + sbio->page_count * PAGE_SIZE !=
1670 spage->logical) {
1671 scrub_wr_submit(sctx);
1672 goto again;
1673 }
1674
1675 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1676 if (ret != PAGE_SIZE) {
1677 if (sbio->page_count < 1) {
1678 bio_put(sbio->bio);
1679 sbio->bio = NULL;
1680 mutex_unlock(&sctx->wr_lock);
1681 return -EIO;
1682 }
1683 scrub_wr_submit(sctx);
1684 goto again;
1685 }
1686
1687 sbio->pagev[sbio->page_count] = spage;
1688 scrub_page_get(spage);
1689 sbio->page_count++;
1690 if (sbio->page_count == sctx->pages_per_wr_bio)
1691 scrub_wr_submit(sctx);
1692 mutex_unlock(&sctx->wr_lock);
1693
1694 return 0;
1695}
1696
1697static void scrub_wr_submit(struct scrub_ctx *sctx)
1698{
1699 struct scrub_bio *sbio;
1700
1701 if (!sctx->wr_curr_bio)
1702 return;
1703
1704 sbio = sctx->wr_curr_bio;
1705 sctx->wr_curr_bio = NULL;
1706 WARN_ON(!sbio->bio->bi_disk);
1707 scrub_pending_bio_inc(sctx);
1708 /* process all writes in a single worker thread. Then the block layer
1709 * orders the requests before sending them to the driver which
1710 * doubled the write performance on spinning disks when measured
1711 * with Linux 3.5 */
1712 btrfsic_submit_bio(sbio->bio);
1713}
1714
1715static void scrub_wr_bio_end_io(struct bio *bio)
1716{
1717 struct scrub_bio *sbio = bio->bi_private;
1718 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
1719
1720 sbio->status = bio->bi_status;
1721 sbio->bio = bio;
1722
1723 btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
1724 scrub_wr_bio_end_io_worker, NULL, NULL);
1725 btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
1726}
1727
1728static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
1729{
1730 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1731 struct scrub_ctx *sctx = sbio->sctx;
1732 int i;
1733
1734 WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
1735 if (sbio->status) {
1736 struct btrfs_dev_replace *dev_replace =
1737 &sbio->sctx->fs_info->dev_replace;
1738
1739 for (i = 0; i < sbio->page_count; i++) {
1740 struct scrub_page *spage = sbio->pagev[i];
1741
1742 spage->io_error = 1;
1743 atomic64_inc(&dev_replace->num_write_errors);
1744 }
1745 }
1746
1747 for (i = 0; i < sbio->page_count; i++)
1748 scrub_page_put(sbio->pagev[i]);
1749
1750 bio_put(sbio->bio);
1751 kfree(sbio);
1752 scrub_pending_bio_dec(sctx);
1753}
1754
1755static int scrub_checksum(struct scrub_block *sblock)
1756{
1757 u64 flags;
1758 int ret;
1759
1760 /*
1761 * No need to initialize these stats currently,
1762 * because this function only use return value
1763 * instead of these stats value.
1764 *
1765 * Todo:
1766 * always use stats
1767 */
1768 sblock->header_error = 0;
1769 sblock->generation_error = 0;
1770 sblock->checksum_error = 0;
1771
1772 WARN_ON(sblock->page_count < 1);
1773 flags = sblock->pagev[0]->flags;
1774 ret = 0;
1775 if (flags & BTRFS_EXTENT_FLAG_DATA)
1776 ret = scrub_checksum_data(sblock);
1777 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1778 ret = scrub_checksum_tree_block(sblock);
1779 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1780 (void)scrub_checksum_super(sblock);
1781 else
1782 WARN_ON(1);
1783 if (ret)
1784 scrub_handle_errored_block(sblock);
1785
1786 return ret;
1787}
1788
1789static int scrub_checksum_data(struct scrub_block *sblock)
1790{
1791 struct scrub_ctx *sctx = sblock->sctx;
1792 struct btrfs_fs_info *fs_info = sctx->fs_info;
1793 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1794 u8 csum[BTRFS_CSUM_SIZE];
1795 u8 *on_disk_csum;
1796 struct page *page;
1797 void *buffer;
1798 u64 len;
1799 int index;
1800
1801 BUG_ON(sblock->page_count < 1);
1802 if (!sblock->pagev[0]->have_csum)
1803 return 0;
1804
1805 shash->tfm = fs_info->csum_shash;
1806 crypto_shash_init(shash);
1807
1808 on_disk_csum = sblock->pagev[0]->csum;
1809 page = sblock->pagev[0]->page;
1810 buffer = kmap_atomic(page);
1811
1812 len = sctx->fs_info->sectorsize;
1813 index = 0;
1814 for (;;) {
1815 u64 l = min_t(u64, len, PAGE_SIZE);
1816
1817 crypto_shash_update(shash, buffer, l);
1818 kunmap_atomic(buffer);
1819 len -= l;
1820 if (len == 0)
1821 break;
1822 index++;
1823 BUG_ON(index >= sblock->page_count);
1824 BUG_ON(!sblock->pagev[index]->page);
1825 page = sblock->pagev[index]->page;
1826 buffer = kmap_atomic(page);
1827 }
1828
1829 crypto_shash_final(shash, csum);
1830 if (memcmp(csum, on_disk_csum, sctx->csum_size))
1831 sblock->checksum_error = 1;
1832
1833 return sblock->checksum_error;
1834}
1835
1836static int scrub_checksum_tree_block(struct scrub_block *sblock)
1837{
1838 struct scrub_ctx *sctx = sblock->sctx;
1839 struct btrfs_header *h;
1840 struct btrfs_fs_info *fs_info = sctx->fs_info;
1841 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1842 u8 calculated_csum[BTRFS_CSUM_SIZE];
1843 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1844 struct page *page;
1845 void *mapped_buffer;
1846 u64 mapped_size;
1847 void *p;
1848 u64 len;
1849 int index;
1850
1851 shash->tfm = fs_info->csum_shash;
1852 crypto_shash_init(shash);
1853
1854 BUG_ON(sblock->page_count < 1);
1855 page = sblock->pagev[0]->page;
1856 mapped_buffer = kmap_atomic(page);
1857 h = (struct btrfs_header *)mapped_buffer;
1858 memcpy(on_disk_csum, h->csum, sctx->csum_size);
1859
1860 /*
1861 * we don't use the getter functions here, as we
1862 * a) don't have an extent buffer and
1863 * b) the page is already kmapped
1864 */
1865 if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
1866 sblock->header_error = 1;
1867
1868 if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
1869 sblock->header_error = 1;
1870 sblock->generation_error = 1;
1871 }
1872
1873 if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
1874 sblock->header_error = 1;
1875
1876 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1877 BTRFS_UUID_SIZE))
1878 sblock->header_error = 1;
1879
1880 len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
1881 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1882 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1883 index = 0;
1884 for (;;) {
1885 u64 l = min_t(u64, len, mapped_size);
1886
1887 crypto_shash_update(shash, p, l);
1888 kunmap_atomic(mapped_buffer);
1889 len -= l;
1890 if (len == 0)
1891 break;
1892 index++;
1893 BUG_ON(index >= sblock->page_count);
1894 BUG_ON(!sblock->pagev[index]->page);
1895 page = sblock->pagev[index]->page;
1896 mapped_buffer = kmap_atomic(page);
1897 mapped_size = PAGE_SIZE;
1898 p = mapped_buffer;
1899 }
1900
1901 crypto_shash_final(shash, calculated_csum);
1902 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1903 sblock->checksum_error = 1;
1904
1905 return sblock->header_error || sblock->checksum_error;
1906}
1907
1908static int scrub_checksum_super(struct scrub_block *sblock)
1909{
1910 struct btrfs_super_block *s;
1911 struct scrub_ctx *sctx = sblock->sctx;
1912 struct btrfs_fs_info *fs_info = sctx->fs_info;
1913 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
1914 u8 calculated_csum[BTRFS_CSUM_SIZE];
1915 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1916 struct page *page;
1917 void *mapped_buffer;
1918 u64 mapped_size;
1919 void *p;
1920 int fail_gen = 0;
1921 int fail_cor = 0;
1922 u64 len;
1923 int index;
1924
1925 shash->tfm = fs_info->csum_shash;
1926 crypto_shash_init(shash);
1927
1928 BUG_ON(sblock->page_count < 1);
1929 page = sblock->pagev[0]->page;
1930 mapped_buffer = kmap_atomic(page);
1931 s = (struct btrfs_super_block *)mapped_buffer;
1932 memcpy(on_disk_csum, s->csum, sctx->csum_size);
1933
1934 if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
1935 ++fail_cor;
1936
1937 if (sblock->pagev[0]->generation != btrfs_super_generation(s))
1938 ++fail_gen;
1939
1940 if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
1941 ++fail_cor;
1942
1943 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1944 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1945 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1946 index = 0;
1947 for (;;) {
1948 u64 l = min_t(u64, len, mapped_size);
1949
1950 crypto_shash_update(shash, p, l);
1951 kunmap_atomic(mapped_buffer);
1952 len -= l;
1953 if (len == 0)
1954 break;
1955 index++;
1956 BUG_ON(index >= sblock->page_count);
1957 BUG_ON(!sblock->pagev[index]->page);
1958 page = sblock->pagev[index]->page;
1959 mapped_buffer = kmap_atomic(page);
1960 mapped_size = PAGE_SIZE;
1961 p = mapped_buffer;
1962 }
1963
1964 crypto_shash_final(shash, calculated_csum);
1965 if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
1966 ++fail_cor;
1967
1968 if (fail_cor + fail_gen) {
1969 /*
1970 * if we find an error in a super block, we just report it.
1971 * They will get written with the next transaction commit
1972 * anyway
1973 */
1974 spin_lock(&sctx->stat_lock);
1975 ++sctx->stat.super_errors;
1976 spin_unlock(&sctx->stat_lock);
1977 if (fail_cor)
1978 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1979 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1980 else
1981 btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
1982 BTRFS_DEV_STAT_GENERATION_ERRS);
1983 }
1984
1985 return fail_cor + fail_gen;
1986}
1987
1988static void scrub_block_get(struct scrub_block *sblock)
1989{
1990 refcount_inc(&sblock->refs);
1991}
1992
1993static void scrub_block_put(struct scrub_block *sblock)
1994{
1995 if (refcount_dec_and_test(&sblock->refs)) {
1996 int i;
1997
1998 if (sblock->sparity)
1999 scrub_parity_put(sblock->sparity);
2000
2001 for (i = 0; i < sblock->page_count; i++)
2002 scrub_page_put(sblock->pagev[i]);
2003 kfree(sblock);
2004 }
2005}
2006
2007static void scrub_page_get(struct scrub_page *spage)
2008{
2009 atomic_inc(&spage->refs);
2010}
2011
2012static void scrub_page_put(struct scrub_page *spage)
2013{
2014 if (atomic_dec_and_test(&spage->refs)) {
2015 if (spage->page)
2016 __free_page(spage->page);
2017 kfree(spage);
2018 }
2019}
2020
2021static void scrub_submit(struct scrub_ctx *sctx)
2022{
2023 struct scrub_bio *sbio;
2024
2025 if (sctx->curr == -1)
2026 return;
2027
2028 sbio = sctx->bios[sctx->curr];
2029 sctx->curr = -1;
2030 scrub_pending_bio_inc(sctx);
2031 btrfsic_submit_bio(sbio->bio);
2032}
2033
2034static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
2035 struct scrub_page *spage)
2036{
2037 struct scrub_block *sblock = spage->sblock;
2038 struct scrub_bio *sbio;
2039 int ret;
2040
2041again:
2042 /*
2043 * grab a fresh bio or wait for one to become available
2044 */
2045 while (sctx->curr == -1) {
2046 spin_lock(&sctx->list_lock);
2047 sctx->curr = sctx->first_free;
2048 if (sctx->curr != -1) {
2049 sctx->first_free = sctx->bios[sctx->curr]->next_free;
2050 sctx->bios[sctx->curr]->next_free = -1;
2051 sctx->bios[sctx->curr]->page_count = 0;
2052 spin_unlock(&sctx->list_lock);
2053 } else {
2054 spin_unlock(&sctx->list_lock);
2055 wait_event(sctx->list_wait, sctx->first_free != -1);
2056 }
2057 }
2058 sbio = sctx->bios[sctx->curr];
2059 if (sbio->page_count == 0) {
2060 struct bio *bio;
2061
2062 sbio->physical = spage->physical;
2063 sbio->logical = spage->logical;
2064 sbio->dev = spage->dev;
2065 bio = sbio->bio;
2066 if (!bio) {
2067 bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
2068 sbio->bio = bio;
2069 }
2070
2071 bio->bi_private = sbio;
2072 bio->bi_end_io = scrub_bio_end_io;
2073 bio_set_dev(bio, sbio->dev->bdev);
2074 bio->bi_iter.bi_sector = sbio->physical >> 9;
2075 bio->bi_opf = REQ_OP_READ;
2076 sbio->status = 0;
2077 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
2078 spage->physical ||
2079 sbio->logical + sbio->page_count * PAGE_SIZE !=
2080 spage->logical ||
2081 sbio->dev != spage->dev) {
2082 scrub_submit(sctx);
2083 goto again;
2084 }
2085
2086 sbio->pagev[sbio->page_count] = spage;
2087 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
2088 if (ret != PAGE_SIZE) {
2089 if (sbio->page_count < 1) {
2090 bio_put(sbio->bio);
2091 sbio->bio = NULL;
2092 return -EIO;
2093 }
2094 scrub_submit(sctx);
2095 goto again;
2096 }
2097
2098 scrub_block_get(sblock); /* one for the page added to the bio */
2099 atomic_inc(&sblock->outstanding_pages);
2100 sbio->page_count++;
2101 if (sbio->page_count == sctx->pages_per_rd_bio)
2102 scrub_submit(sctx);
2103
2104 return 0;
2105}
2106
2107static void scrub_missing_raid56_end_io(struct bio *bio)
2108{
2109 struct scrub_block *sblock = bio->bi_private;
2110 struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
2111
2112 if (bio->bi_status)
2113 sblock->no_io_error_seen = 0;
2114
2115 bio_put(bio);
2116
2117 btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
2118}
2119
2120static void scrub_missing_raid56_worker(struct btrfs_work *work)
2121{
2122 struct scrub_block *sblock = container_of(work, struct scrub_block, work);
2123 struct scrub_ctx *sctx = sblock->sctx;
2124 struct btrfs_fs_info *fs_info = sctx->fs_info;
2125 u64 logical;
2126 struct btrfs_device *dev;
2127
2128 logical = sblock->pagev[0]->logical;
2129 dev = sblock->pagev[0]->dev;
2130
2131 if (sblock->no_io_error_seen)
2132 scrub_recheck_block_checksum(sblock);
2133
2134 if (!sblock->no_io_error_seen) {
2135 spin_lock(&sctx->stat_lock);
2136 sctx->stat.read_errors++;
2137 spin_unlock(&sctx->stat_lock);
2138 btrfs_err_rl_in_rcu(fs_info,
2139 "IO error rebuilding logical %llu for dev %s",
2140 logical, rcu_str_deref(dev->name));
2141 } else if (sblock->header_error || sblock->checksum_error) {
2142 spin_lock(&sctx->stat_lock);
2143 sctx->stat.uncorrectable_errors++;
2144 spin_unlock(&sctx->stat_lock);
2145 btrfs_err_rl_in_rcu(fs_info,
2146 "failed to rebuild valid logical %llu for dev %s",
2147 logical, rcu_str_deref(dev->name));
2148 } else {
2149 scrub_write_block_to_dev_replace(sblock);
2150 }
2151
2152 scrub_block_put(sblock);
2153
2154 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2155 mutex_lock(&sctx->wr_lock);
2156 scrub_wr_submit(sctx);
2157 mutex_unlock(&sctx->wr_lock);
2158 }
2159
2160 scrub_pending_bio_dec(sctx);
2161}
2162
2163static void scrub_missing_raid56_pages(struct scrub_block *sblock)
2164{
2165 struct scrub_ctx *sctx = sblock->sctx;
2166 struct btrfs_fs_info *fs_info = sctx->fs_info;
2167 u64 length = sblock->page_count * PAGE_SIZE;
2168 u64 logical = sblock->pagev[0]->logical;
2169 struct btrfs_bio *bbio = NULL;
2170 struct bio *bio;
2171 struct btrfs_raid_bio *rbio;
2172 int ret;
2173 int i;
2174
2175 btrfs_bio_counter_inc_blocked(fs_info);
2176 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
2177 &length, &bbio);
2178 if (ret || !bbio || !bbio->raid_map)
2179 goto bbio_out;
2180
2181 if (WARN_ON(!sctx->is_dev_replace ||
2182 !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
2183 /*
2184 * We shouldn't be scrubbing a missing device. Even for dev
2185 * replace, we should only get here for RAID 5/6. We either
2186 * managed to mount something with no mirrors remaining or
2187 * there's a bug in scrub_remap_extent()/btrfs_map_block().
2188 */
2189 goto bbio_out;
2190 }
2191
2192 bio = btrfs_io_bio_alloc(0);
2193 bio->bi_iter.bi_sector = logical >> 9;
2194 bio->bi_private = sblock;
2195 bio->bi_end_io = scrub_missing_raid56_end_io;
2196
2197 rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
2198 if (!rbio)
2199 goto rbio_out;
2200
2201 for (i = 0; i < sblock->page_count; i++) {
2202 struct scrub_page *spage = sblock->pagev[i];
2203
2204 raid56_add_scrub_pages(rbio, spage->page, spage->logical);
2205 }
2206
2207 btrfs_init_work(&sblock->work, btrfs_scrub_helper,
2208 scrub_missing_raid56_worker, NULL, NULL);
2209 scrub_block_get(sblock);
2210 scrub_pending_bio_inc(sctx);
2211 raid56_submit_missing_rbio(rbio);
2212 return;
2213
2214rbio_out:
2215 bio_put(bio);
2216bbio_out:
2217 btrfs_bio_counter_dec(fs_info);
2218 btrfs_put_bbio(bbio);
2219 spin_lock(&sctx->stat_lock);
2220 sctx->stat.malloc_errors++;
2221 spin_unlock(&sctx->stat_lock);
2222}
2223
2224static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
2225 u64 physical, struct btrfs_device *dev, u64 flags,
2226 u64 gen, int mirror_num, u8 *csum, int force,
2227 u64 physical_for_dev_replace)
2228{
2229 struct scrub_block *sblock;
2230 int index;
2231
2232 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2233 if (!sblock) {
2234 spin_lock(&sctx->stat_lock);
2235 sctx->stat.malloc_errors++;
2236 spin_unlock(&sctx->stat_lock);
2237 return -ENOMEM;
2238 }
2239
2240 /* one ref inside this function, plus one for each page added to
2241 * a bio later on */
2242 refcount_set(&sblock->refs, 1);
2243 sblock->sctx = sctx;
2244 sblock->no_io_error_seen = 1;
2245
2246 for (index = 0; len > 0; index++) {
2247 struct scrub_page *spage;
2248 u64 l = min_t(u64, len, PAGE_SIZE);
2249
2250 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2251 if (!spage) {
2252leave_nomem:
2253 spin_lock(&sctx->stat_lock);
2254 sctx->stat.malloc_errors++;
2255 spin_unlock(&sctx->stat_lock);
2256 scrub_block_put(sblock);
2257 return -ENOMEM;
2258 }
2259 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2260 scrub_page_get(spage);
2261 sblock->pagev[index] = spage;
2262 spage->sblock = sblock;
2263 spage->dev = dev;
2264 spage->flags = flags;
2265 spage->generation = gen;
2266 spage->logical = logical;
2267 spage->physical = physical;
2268 spage->physical_for_dev_replace = physical_for_dev_replace;
2269 spage->mirror_num = mirror_num;
2270 if (csum) {
2271 spage->have_csum = 1;
2272 memcpy(spage->csum, csum, sctx->csum_size);
2273 } else {
2274 spage->have_csum = 0;
2275 }
2276 sblock->page_count++;
2277 spage->page = alloc_page(GFP_KERNEL);
2278 if (!spage->page)
2279 goto leave_nomem;
2280 len -= l;
2281 logical += l;
2282 physical += l;
2283 physical_for_dev_replace += l;
2284 }
2285
2286 WARN_ON(sblock->page_count == 0);
2287 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2288 /*
2289 * This case should only be hit for RAID 5/6 device replace. See
2290 * the comment in scrub_missing_raid56_pages() for details.
2291 */
2292 scrub_missing_raid56_pages(sblock);
2293 } else {
2294 for (index = 0; index < sblock->page_count; index++) {
2295 struct scrub_page *spage = sblock->pagev[index];
2296 int ret;
2297
2298 ret = scrub_add_page_to_rd_bio(sctx, spage);
2299 if (ret) {
2300 scrub_block_put(sblock);
2301 return ret;
2302 }
2303 }
2304
2305 if (force)
2306 scrub_submit(sctx);
2307 }
2308
2309 /* last one frees, either here or in bio completion for last page */
2310 scrub_block_put(sblock);
2311 return 0;
2312}
2313
2314static void scrub_bio_end_io(struct bio *bio)
2315{
2316 struct scrub_bio *sbio = bio->bi_private;
2317 struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
2318
2319 sbio->status = bio->bi_status;
2320 sbio->bio = bio;
2321
2322 btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
2323}
2324
2325static void scrub_bio_end_io_worker(struct btrfs_work *work)
2326{
2327 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
2328 struct scrub_ctx *sctx = sbio->sctx;
2329 int i;
2330
2331 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
2332 if (sbio->status) {
2333 for (i = 0; i < sbio->page_count; i++) {
2334 struct scrub_page *spage = sbio->pagev[i];
2335
2336 spage->io_error = 1;
2337 spage->sblock->no_io_error_seen = 0;
2338 }
2339 }
2340
2341 /* now complete the scrub_block items that have all pages completed */
2342 for (i = 0; i < sbio->page_count; i++) {
2343 struct scrub_page *spage = sbio->pagev[i];
2344 struct scrub_block *sblock = spage->sblock;
2345
2346 if (atomic_dec_and_test(&sblock->outstanding_pages))
2347 scrub_block_complete(sblock);
2348 scrub_block_put(sblock);
2349 }
2350
2351 bio_put(sbio->bio);
2352 sbio->bio = NULL;
2353 spin_lock(&sctx->list_lock);
2354 sbio->next_free = sctx->first_free;
2355 sctx->first_free = sbio->index;
2356 spin_unlock(&sctx->list_lock);
2357
2358 if (sctx->is_dev_replace && sctx->flush_all_writes) {
2359 mutex_lock(&sctx->wr_lock);
2360 scrub_wr_submit(sctx);
2361 mutex_unlock(&sctx->wr_lock);
2362 }
2363
2364 scrub_pending_bio_dec(sctx);
2365}
2366
2367static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
2368 unsigned long *bitmap,
2369 u64 start, u64 len)
2370{
2371 u64 offset;
2372 u64 nsectors64;
2373 u32 nsectors;
2374 int sectorsize = sparity->sctx->fs_info->sectorsize;
2375
2376 if (len >= sparity->stripe_len) {
2377 bitmap_set(bitmap, 0, sparity->nsectors);
2378 return;
2379 }
2380
2381 start -= sparity->logic_start;
2382 start = div64_u64_rem(start, sparity->stripe_len, &offset);
2383 offset = div_u64(offset, sectorsize);
2384 nsectors64 = div_u64(len, sectorsize);
2385
2386 ASSERT(nsectors64 < UINT_MAX);
2387 nsectors = (u32)nsectors64;
2388
2389 if (offset + nsectors <= sparity->nsectors) {
2390 bitmap_set(bitmap, offset, nsectors);
2391 return;
2392 }
2393
2394 bitmap_set(bitmap, offset, sparity->nsectors - offset);
2395 bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
2396}
2397
2398static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
2399 u64 start, u64 len)
2400{
2401 __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
2402}
2403
2404static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
2405 u64 start, u64 len)
2406{
2407 __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
2408}
2409
2410static void scrub_block_complete(struct scrub_block *sblock)
2411{
2412 int corrupted = 0;
2413
2414 if (!sblock->no_io_error_seen) {
2415 corrupted = 1;
2416 scrub_handle_errored_block(sblock);
2417 } else {
2418 /*
2419 * if has checksum error, write via repair mechanism in
2420 * dev replace case, otherwise write here in dev replace
2421 * case.
2422 */
2423 corrupted = scrub_checksum(sblock);
2424 if (!corrupted && sblock->sctx->is_dev_replace)
2425 scrub_write_block_to_dev_replace(sblock);
2426 }
2427
2428 if (sblock->sparity && corrupted && !sblock->data_corrected) {
2429 u64 start = sblock->pagev[0]->logical;
2430 u64 end = sblock->pagev[sblock->page_count - 1]->logical +
2431 PAGE_SIZE;
2432
2433 scrub_parity_mark_sectors_error(sblock->sparity,
2434 start, end - start);
2435 }
2436}
2437
2438static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
2439{
2440 struct btrfs_ordered_sum *sum = NULL;
2441 unsigned long index;
2442 unsigned long num_sectors;
2443
2444 while (!list_empty(&sctx->csum_list)) {
2445 sum = list_first_entry(&sctx->csum_list,
2446 struct btrfs_ordered_sum, list);
2447 if (sum->bytenr > logical)
2448 return 0;
2449 if (sum->bytenr + sum->len > logical)
2450 break;
2451
2452 ++sctx->stat.csum_discards;
2453 list_del(&sum->list);
2454 kfree(sum);
2455 sum = NULL;
2456 }
2457 if (!sum)
2458 return 0;
2459
2460 index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
2461 ASSERT(index < UINT_MAX);
2462
2463 num_sectors = sum->len / sctx->fs_info->sectorsize;
2464 memcpy(csum, sum->sums + index * sctx->csum_size, sctx->csum_size);
2465 if (index == num_sectors - 1) {
2466 list_del(&sum->list);
2467 kfree(sum);
2468 }
2469 return 1;
2470}
2471
2472/* scrub extent tries to collect up to 64 kB for each bio */
2473static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
2474 u64 logical, u64 len,
2475 u64 physical, struct btrfs_device *dev, u64 flags,
2476 u64 gen, int mirror_num, u64 physical_for_dev_replace)
2477{
2478 int ret;
2479 u8 csum[BTRFS_CSUM_SIZE];
2480 u32 blocksize;
2481
2482 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2483 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2484 blocksize = map->stripe_len;
2485 else
2486 blocksize = sctx->fs_info->sectorsize;
2487 spin_lock(&sctx->stat_lock);
2488 sctx->stat.data_extents_scrubbed++;
2489 sctx->stat.data_bytes_scrubbed += len;
2490 spin_unlock(&sctx->stat_lock);
2491 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2492 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2493 blocksize = map->stripe_len;
2494 else
2495 blocksize = sctx->fs_info->nodesize;
2496 spin_lock(&sctx->stat_lock);
2497 sctx->stat.tree_extents_scrubbed++;
2498 sctx->stat.tree_bytes_scrubbed += len;
2499 spin_unlock(&sctx->stat_lock);
2500 } else {
2501 blocksize = sctx->fs_info->sectorsize;
2502 WARN_ON(1);
2503 }
2504
2505 while (len) {
2506 u64 l = min_t(u64, len, blocksize);
2507 int have_csum = 0;
2508
2509 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2510 /* push csums to sbio */
2511 have_csum = scrub_find_csum(sctx, logical, csum);
2512 if (have_csum == 0)
2513 ++sctx->stat.no_csum;
2514 }
2515 ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
2516 mirror_num, have_csum ? csum : NULL, 0,
2517 physical_for_dev_replace);
2518 if (ret)
2519 return ret;
2520 len -= l;
2521 logical += l;
2522 physical += l;
2523 physical_for_dev_replace += l;
2524 }
2525 return 0;
2526}
2527
2528static int scrub_pages_for_parity(struct scrub_parity *sparity,
2529 u64 logical, u64 len,
2530 u64 physical, struct btrfs_device *dev,
2531 u64 flags, u64 gen, int mirror_num, u8 *csum)
2532{
2533 struct scrub_ctx *sctx = sparity->sctx;
2534 struct scrub_block *sblock;
2535 int index;
2536
2537 sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
2538 if (!sblock) {
2539 spin_lock(&sctx->stat_lock);
2540 sctx->stat.malloc_errors++;
2541 spin_unlock(&sctx->stat_lock);
2542 return -ENOMEM;
2543 }
2544
2545 /* one ref inside this function, plus one for each page added to
2546 * a bio later on */
2547 refcount_set(&sblock->refs, 1);
2548 sblock->sctx = sctx;
2549 sblock->no_io_error_seen = 1;
2550 sblock->sparity = sparity;
2551 scrub_parity_get(sparity);
2552
2553 for (index = 0; len > 0; index++) {
2554 struct scrub_page *spage;
2555 u64 l = min_t(u64, len, PAGE_SIZE);
2556
2557 spage = kzalloc(sizeof(*spage), GFP_KERNEL);
2558 if (!spage) {
2559leave_nomem:
2560 spin_lock(&sctx->stat_lock);
2561 sctx->stat.malloc_errors++;
2562 spin_unlock(&sctx->stat_lock);
2563 scrub_block_put(sblock);
2564 return -ENOMEM;
2565 }
2566 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
2567 /* For scrub block */
2568 scrub_page_get(spage);
2569 sblock->pagev[index] = spage;
2570 /* For scrub parity */
2571 scrub_page_get(spage);
2572 list_add_tail(&spage->list, &sparity->spages);
2573 spage->sblock = sblock;
2574 spage->dev = dev;
2575 spage->flags = flags;
2576 spage->generation = gen;
2577 spage->logical = logical;
2578 spage->physical = physical;
2579 spage->mirror_num = mirror_num;
2580 if (csum) {
2581 spage->have_csum = 1;
2582 memcpy(spage->csum, csum, sctx->csum_size);
2583 } else {
2584 spage->have_csum = 0;
2585 }
2586 sblock->page_count++;
2587 spage->page = alloc_page(GFP_KERNEL);
2588 if (!spage->page)
2589 goto leave_nomem;
2590 len -= l;
2591 logical += l;
2592 physical += l;
2593 }
2594
2595 WARN_ON(sblock->page_count == 0);
2596 for (index = 0; index < sblock->page_count; index++) {
2597 struct scrub_page *spage = sblock->pagev[index];
2598 int ret;
2599
2600 ret = scrub_add_page_to_rd_bio(sctx, spage);
2601 if (ret) {
2602 scrub_block_put(sblock);
2603 return ret;
2604 }
2605 }
2606
2607 /* last one frees, either here or in bio completion for last page */
2608 scrub_block_put(sblock);
2609 return 0;
2610}
2611
2612static int scrub_extent_for_parity(struct scrub_parity *sparity,
2613 u64 logical, u64 len,
2614 u64 physical, struct btrfs_device *dev,
2615 u64 flags, u64 gen, int mirror_num)
2616{
2617 struct scrub_ctx *sctx = sparity->sctx;
2618 int ret;
2619 u8 csum[BTRFS_CSUM_SIZE];
2620 u32 blocksize;
2621
2622 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
2623 scrub_parity_mark_sectors_error(sparity, logical, len);
2624 return 0;
2625 }
2626
2627 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2628 blocksize = sparity->stripe_len;
2629 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
2630 blocksize = sparity->stripe_len;
2631 } else {
2632 blocksize = sctx->fs_info->sectorsize;
2633 WARN_ON(1);
2634 }
2635
2636 while (len) {
2637 u64 l = min_t(u64, len, blocksize);
2638 int have_csum = 0;
2639
2640 if (flags & BTRFS_EXTENT_FLAG_DATA) {
2641 /* push csums to sbio */
2642 have_csum = scrub_find_csum(sctx, logical, csum);
2643 if (have_csum == 0)
2644 goto skip;
2645 }
2646 ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
2647 flags, gen, mirror_num,
2648 have_csum ? csum : NULL);
2649 if (ret)
2650 return ret;
2651skip:
2652 len -= l;
2653 logical += l;
2654 physical += l;
2655 }
2656 return 0;
2657}
2658
2659/*
2660 * Given a physical address, this will calculate it's
2661 * logical offset. if this is a parity stripe, it will return
2662 * the most left data stripe's logical offset.
2663 *
2664 * return 0 if it is a data stripe, 1 means parity stripe.
2665 */
2666static int get_raid56_logic_offset(u64 physical, int num,
2667 struct map_lookup *map, u64 *offset,
2668 u64 *stripe_start)
2669{
2670 int i;
2671 int j = 0;
2672 u64 stripe_nr;
2673 u64 last_offset;
2674 u32 stripe_index;
2675 u32 rot;
2676 const int data_stripes = nr_data_stripes(map);
2677
2678 last_offset = (physical - map->stripes[num].physical) * data_stripes;
2679 if (stripe_start)
2680 *stripe_start = last_offset;
2681
2682 *offset = last_offset;
2683 for (i = 0; i < data_stripes; i++) {
2684 *offset = last_offset + i * map->stripe_len;
2685
2686 stripe_nr = div64_u64(*offset, map->stripe_len);
2687 stripe_nr = div_u64(stripe_nr, data_stripes);
2688
2689 /* Work out the disk rotation on this stripe-set */
2690 stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
2691 /* calculate which stripe this data locates */
2692 rot += i;
2693 stripe_index = rot % map->num_stripes;
2694 if (stripe_index == num)
2695 return 0;
2696 if (stripe_index < num)
2697 j++;
2698 }
2699 *offset = last_offset + j * map->stripe_len;
2700 return 1;
2701}
2702
2703static void scrub_free_parity(struct scrub_parity *sparity)
2704{
2705 struct scrub_ctx *sctx = sparity->sctx;
2706 struct scrub_page *curr, *next;
2707 int nbits;
2708
2709 nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
2710 if (nbits) {
2711 spin_lock(&sctx->stat_lock);
2712 sctx->stat.read_errors += nbits;
2713 sctx->stat.uncorrectable_errors += nbits;
2714 spin_unlock(&sctx->stat_lock);
2715 }
2716
2717 list_for_each_entry_safe(curr, next, &sparity->spages, list) {
2718 list_del_init(&curr->list);
2719 scrub_page_put(curr);
2720 }
2721
2722 kfree(sparity);
2723}
2724
2725static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
2726{
2727 struct scrub_parity *sparity = container_of(work, struct scrub_parity,
2728 work);
2729 struct scrub_ctx *sctx = sparity->sctx;
2730
2731 scrub_free_parity(sparity);
2732 scrub_pending_bio_dec(sctx);
2733}
2734
2735static void scrub_parity_bio_endio(struct bio *bio)
2736{
2737 struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
2738 struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
2739
2740 if (bio->bi_status)
2741 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2742 sparity->nsectors);
2743
2744 bio_put(bio);
2745
2746 btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
2747 scrub_parity_bio_endio_worker, NULL, NULL);
2748 btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
2749}
2750
2751static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
2752{
2753 struct scrub_ctx *sctx = sparity->sctx;
2754 struct btrfs_fs_info *fs_info = sctx->fs_info;
2755 struct bio *bio;
2756 struct btrfs_raid_bio *rbio;
2757 struct btrfs_bio *bbio = NULL;
2758 u64 length;
2759 int ret;
2760
2761 if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
2762 sparity->nsectors))
2763 goto out;
2764
2765 length = sparity->logic_end - sparity->logic_start;
2766
2767 btrfs_bio_counter_inc_blocked(fs_info);
2768 ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
2769 &length, &bbio);
2770 if (ret || !bbio || !bbio->raid_map)
2771 goto bbio_out;
2772
2773 bio = btrfs_io_bio_alloc(0);
2774 bio->bi_iter.bi_sector = sparity->logic_start >> 9;
2775 bio->bi_private = sparity;
2776 bio->bi_end_io = scrub_parity_bio_endio;
2777
2778 rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
2779 length, sparity->scrub_dev,
2780 sparity->dbitmap,
2781 sparity->nsectors);
2782 if (!rbio)
2783 goto rbio_out;
2784
2785 scrub_pending_bio_inc(sctx);
2786 raid56_parity_submit_scrub_rbio(rbio);
2787 return;
2788
2789rbio_out:
2790 bio_put(bio);
2791bbio_out:
2792 btrfs_bio_counter_dec(fs_info);
2793 btrfs_put_bbio(bbio);
2794 bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
2795 sparity->nsectors);
2796 spin_lock(&sctx->stat_lock);
2797 sctx->stat.malloc_errors++;
2798 spin_unlock(&sctx->stat_lock);
2799out:
2800 scrub_free_parity(sparity);
2801}
2802
2803static inline int scrub_calc_parity_bitmap_len(int nsectors)
2804{
2805 return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
2806}
2807
2808static void scrub_parity_get(struct scrub_parity *sparity)
2809{
2810 refcount_inc(&sparity->refs);
2811}
2812
2813static void scrub_parity_put(struct scrub_parity *sparity)
2814{
2815 if (!refcount_dec_and_test(&sparity->refs))
2816 return;
2817
2818 scrub_parity_check_and_repair(sparity);
2819}
2820
2821static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
2822 struct map_lookup *map,
2823 struct btrfs_device *sdev,
2824 struct btrfs_path *path,
2825 u64 logic_start,
2826 u64 logic_end)
2827{
2828 struct btrfs_fs_info *fs_info = sctx->fs_info;
2829 struct btrfs_root *root = fs_info->extent_root;
2830 struct btrfs_root *csum_root = fs_info->csum_root;
2831 struct btrfs_extent_item *extent;
2832 struct btrfs_bio *bbio = NULL;
2833 u64 flags;
2834 int ret;
2835 int slot;
2836 struct extent_buffer *l;
2837 struct btrfs_key key;
2838 u64 generation;
2839 u64 extent_logical;
2840 u64 extent_physical;
2841 u64 extent_len;
2842 u64 mapped_length;
2843 struct btrfs_device *extent_dev;
2844 struct scrub_parity *sparity;
2845 int nsectors;
2846 int bitmap_len;
2847 int extent_mirror_num;
2848 int stop_loop = 0;
2849
2850 nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
2851 bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
2852 sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
2853 GFP_NOFS);
2854 if (!sparity) {
2855 spin_lock(&sctx->stat_lock);
2856 sctx->stat.malloc_errors++;
2857 spin_unlock(&sctx->stat_lock);
2858 return -ENOMEM;
2859 }
2860
2861 sparity->stripe_len = map->stripe_len;
2862 sparity->nsectors = nsectors;
2863 sparity->sctx = sctx;
2864 sparity->scrub_dev = sdev;
2865 sparity->logic_start = logic_start;
2866 sparity->logic_end = logic_end;
2867 refcount_set(&sparity->refs, 1);
2868 INIT_LIST_HEAD(&sparity->spages);
2869 sparity->dbitmap = sparity->bitmap;
2870 sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
2871
2872 ret = 0;
2873 while (logic_start < logic_end) {
2874 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2875 key.type = BTRFS_METADATA_ITEM_KEY;
2876 else
2877 key.type = BTRFS_EXTENT_ITEM_KEY;
2878 key.objectid = logic_start;
2879 key.offset = (u64)-1;
2880
2881 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2882 if (ret < 0)
2883 goto out;
2884
2885 if (ret > 0) {
2886 ret = btrfs_previous_extent_item(root, path, 0);
2887 if (ret < 0)
2888 goto out;
2889 if (ret > 0) {
2890 btrfs_release_path(path);
2891 ret = btrfs_search_slot(NULL, root, &key,
2892 path, 0, 0);
2893 if (ret < 0)
2894 goto out;
2895 }
2896 }
2897
2898 stop_loop = 0;
2899 while (1) {
2900 u64 bytes;
2901
2902 l = path->nodes[0];
2903 slot = path->slots[0];
2904 if (slot >= btrfs_header_nritems(l)) {
2905 ret = btrfs_next_leaf(root, path);
2906 if (ret == 0)
2907 continue;
2908 if (ret < 0)
2909 goto out;
2910
2911 stop_loop = 1;
2912 break;
2913 }
2914 btrfs_item_key_to_cpu(l, &key, slot);
2915
2916 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
2917 key.type != BTRFS_METADATA_ITEM_KEY)
2918 goto next;
2919
2920 if (key.type == BTRFS_METADATA_ITEM_KEY)
2921 bytes = fs_info->nodesize;
2922 else
2923 bytes = key.offset;
2924
2925 if (key.objectid + bytes <= logic_start)
2926 goto next;
2927
2928 if (key.objectid >= logic_end) {
2929 stop_loop = 1;
2930 break;
2931 }
2932
2933 while (key.objectid >= logic_start + map->stripe_len)
2934 logic_start += map->stripe_len;
2935
2936 extent = btrfs_item_ptr(l, slot,
2937 struct btrfs_extent_item);
2938 flags = btrfs_extent_flags(l, extent);
2939 generation = btrfs_extent_generation(l, extent);
2940
2941 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
2942 (key.objectid < logic_start ||
2943 key.objectid + bytes >
2944 logic_start + map->stripe_len)) {
2945 btrfs_err(fs_info,
2946 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
2947 key.objectid, logic_start);
2948 spin_lock(&sctx->stat_lock);
2949 sctx->stat.uncorrectable_errors++;
2950 spin_unlock(&sctx->stat_lock);
2951 goto next;
2952 }
2953again:
2954 extent_logical = key.objectid;
2955 extent_len = bytes;
2956
2957 if (extent_logical < logic_start) {
2958 extent_len -= logic_start - extent_logical;
2959 extent_logical = logic_start;
2960 }
2961
2962 if (extent_logical + extent_len >
2963 logic_start + map->stripe_len)
2964 extent_len = logic_start + map->stripe_len -
2965 extent_logical;
2966
2967 scrub_parity_mark_sectors_data(sparity, extent_logical,
2968 extent_len);
2969
2970 mapped_length = extent_len;
2971 bbio = NULL;
2972 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
2973 extent_logical, &mapped_length, &bbio,
2974 0);
2975 if (!ret) {
2976 if (!bbio || mapped_length < extent_len)
2977 ret = -EIO;
2978 }
2979 if (ret) {
2980 btrfs_put_bbio(bbio);
2981 goto out;
2982 }
2983 extent_physical = bbio->stripes[0].physical;
2984 extent_mirror_num = bbio->mirror_num;
2985 extent_dev = bbio->stripes[0].dev;
2986 btrfs_put_bbio(bbio);
2987
2988 ret = btrfs_lookup_csums_range(csum_root,
2989 extent_logical,
2990 extent_logical + extent_len - 1,
2991 &sctx->csum_list, 1);
2992 if (ret)
2993 goto out;
2994
2995 ret = scrub_extent_for_parity(sparity, extent_logical,
2996 extent_len,
2997 extent_physical,
2998 extent_dev, flags,
2999 generation,
3000 extent_mirror_num);
3001
3002 scrub_free_csums(sctx);
3003
3004 if (ret)
3005 goto out;
3006
3007 if (extent_logical + extent_len <
3008 key.objectid + bytes) {
3009 logic_start += map->stripe_len;
3010
3011 if (logic_start >= logic_end) {
3012 stop_loop = 1;
3013 break;
3014 }
3015
3016 if (logic_start < key.objectid + bytes) {
3017 cond_resched();
3018 goto again;
3019 }
3020 }
3021next:
3022 path->slots[0]++;
3023 }
3024
3025 btrfs_release_path(path);
3026
3027 if (stop_loop)
3028 break;
3029
3030 logic_start += map->stripe_len;
3031 }
3032out:
3033 if (ret < 0)
3034 scrub_parity_mark_sectors_error(sparity, logic_start,
3035 logic_end - logic_start);
3036 scrub_parity_put(sparity);
3037 scrub_submit(sctx);
3038 mutex_lock(&sctx->wr_lock);
3039 scrub_wr_submit(sctx);
3040 mutex_unlock(&sctx->wr_lock);
3041
3042 btrfs_release_path(path);
3043 return ret < 0 ? ret : 0;
3044}
3045
3046static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
3047 struct map_lookup *map,
3048 struct btrfs_device *scrub_dev,
3049 int num, u64 base, u64 length)
3050{
3051 struct btrfs_path *path, *ppath;
3052 struct btrfs_fs_info *fs_info = sctx->fs_info;
3053 struct btrfs_root *root = fs_info->extent_root;
3054 struct btrfs_root *csum_root = fs_info->csum_root;
3055 struct btrfs_extent_item *extent;
3056 struct blk_plug plug;
3057 u64 flags;
3058 int ret;
3059 int slot;
3060 u64 nstripes;
3061 struct extent_buffer *l;
3062 u64 physical;
3063 u64 logical;
3064 u64 logic_end;
3065 u64 physical_end;
3066 u64 generation;
3067 int mirror_num;
3068 struct reada_control *reada1;
3069 struct reada_control *reada2;
3070 struct btrfs_key key;
3071 struct btrfs_key key_end;
3072 u64 increment = map->stripe_len;
3073 u64 offset;
3074 u64 extent_logical;
3075 u64 extent_physical;
3076 u64 extent_len;
3077 u64 stripe_logical;
3078 u64 stripe_end;
3079 struct btrfs_device *extent_dev;
3080 int extent_mirror_num;
3081 int stop_loop = 0;
3082
3083 physical = map->stripes[num].physical;
3084 offset = 0;
3085 nstripes = div64_u64(length, map->stripe_len);
3086 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3087 offset = map->stripe_len * num;
3088 increment = map->stripe_len * map->num_stripes;
3089 mirror_num = 1;
3090 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3091 int factor = map->num_stripes / map->sub_stripes;
3092 offset = map->stripe_len * (num / map->sub_stripes);
3093 increment = map->stripe_len * factor;
3094 mirror_num = num % map->sub_stripes + 1;
3095 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
3096 increment = map->stripe_len;
3097 mirror_num = num % map->num_stripes + 1;
3098 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3099 increment = map->stripe_len;
3100 mirror_num = num % map->num_stripes + 1;
3101 } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3102 get_raid56_logic_offset(physical, num, map, &offset, NULL);
3103 increment = map->stripe_len * nr_data_stripes(map);
3104 mirror_num = 1;
3105 } else {
3106 increment = map->stripe_len;
3107 mirror_num = 1;
3108 }
3109
3110 path = btrfs_alloc_path();
3111 if (!path)
3112 return -ENOMEM;
3113
3114 ppath = btrfs_alloc_path();
3115 if (!ppath) {
3116 btrfs_free_path(path);
3117 return -ENOMEM;
3118 }
3119
3120 /*
3121 * work on commit root. The related disk blocks are static as
3122 * long as COW is applied. This means, it is save to rewrite
3123 * them to repair disk errors without any race conditions
3124 */
3125 path->search_commit_root = 1;
3126 path->skip_locking = 1;
3127
3128 ppath->search_commit_root = 1;
3129 ppath->skip_locking = 1;
3130 /*
3131 * trigger the readahead for extent tree csum tree and wait for
3132 * completion. During readahead, the scrub is officially paused
3133 * to not hold off transaction commits
3134 */
3135 logical = base + offset;
3136 physical_end = physical + nstripes * map->stripe_len;
3137 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3138 get_raid56_logic_offset(physical_end, num,
3139 map, &logic_end, NULL);
3140 logic_end += base;
3141 } else {
3142 logic_end = logical + increment * nstripes;
3143 }
3144 wait_event(sctx->list_wait,
3145 atomic_read(&sctx->bios_in_flight) == 0);
3146 scrub_blocked_if_needed(fs_info);
3147
3148 /* FIXME it might be better to start readahead at commit root */
3149 key.objectid = logical;
3150 key.type = BTRFS_EXTENT_ITEM_KEY;
3151 key.offset = (u64)0;
3152 key_end.objectid = logic_end;
3153 key_end.type = BTRFS_METADATA_ITEM_KEY;
3154 key_end.offset = (u64)-1;
3155 reada1 = btrfs_reada_add(root, &key, &key_end);
3156
3157 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3158 key.type = BTRFS_EXTENT_CSUM_KEY;
3159 key.offset = logical;
3160 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
3161 key_end.type = BTRFS_EXTENT_CSUM_KEY;
3162 key_end.offset = logic_end;
3163 reada2 = btrfs_reada_add(csum_root, &key, &key_end);
3164
3165 if (!IS_ERR(reada1))
3166 btrfs_reada_wait(reada1);
3167 if (!IS_ERR(reada2))
3168 btrfs_reada_wait(reada2);
3169
3170
3171 /*
3172 * collect all data csums for the stripe to avoid seeking during
3173 * the scrub. This might currently (crc32) end up to be about 1MB
3174 */
3175 blk_start_plug(&plug);
3176
3177 /*
3178 * now find all extents for each stripe and scrub them
3179 */
3180 ret = 0;
3181 while (physical < physical_end) {
3182 /*
3183 * canceled?
3184 */
3185 if (atomic_read(&fs_info->scrub_cancel_req) ||
3186 atomic_read(&sctx->cancel_req)) {
3187 ret = -ECANCELED;
3188 goto out;
3189 }
3190 /*
3191 * check to see if we have to pause
3192 */
3193 if (atomic_read(&fs_info->scrub_pause_req)) {
3194 /* push queued extents */
3195 sctx->flush_all_writes = true;
3196 scrub_submit(sctx);
3197 mutex_lock(&sctx->wr_lock);
3198 scrub_wr_submit(sctx);
3199 mutex_unlock(&sctx->wr_lock);
3200 wait_event(sctx->list_wait,
3201 atomic_read(&sctx->bios_in_flight) == 0);
3202 sctx->flush_all_writes = false;
3203 scrub_blocked_if_needed(fs_info);
3204 }
3205
3206 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3207 ret = get_raid56_logic_offset(physical, num, map,
3208 &logical,
3209 &stripe_logical);
3210 logical += base;
3211 if (ret) {
3212 /* it is parity strip */
3213 stripe_logical += base;
3214 stripe_end = stripe_logical + increment;
3215 ret = scrub_raid56_parity(sctx, map, scrub_dev,
3216 ppath, stripe_logical,
3217 stripe_end);
3218 if (ret)
3219 goto out;
3220 goto skip;
3221 }
3222 }
3223
3224 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
3225 key.type = BTRFS_METADATA_ITEM_KEY;
3226 else
3227 key.type = BTRFS_EXTENT_ITEM_KEY;
3228 key.objectid = logical;
3229 key.offset = (u64)-1;
3230
3231 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3232 if (ret < 0)
3233 goto out;
3234
3235 if (ret > 0) {
3236 ret = btrfs_previous_extent_item(root, path, 0);
3237 if (ret < 0)
3238 goto out;
3239 if (ret > 0) {
3240 /* there's no smaller item, so stick with the
3241 * larger one */
3242 btrfs_release_path(path);
3243 ret = btrfs_search_slot(NULL, root, &key,
3244 path, 0, 0);
3245 if (ret < 0)
3246 goto out;
3247 }
3248 }
3249
3250 stop_loop = 0;
3251 while (1) {
3252 u64 bytes;
3253
3254 l = path->nodes[0];
3255 slot = path->slots[0];
3256 if (slot >= btrfs_header_nritems(l)) {
3257 ret = btrfs_next_leaf(root, path);
3258 if (ret == 0)
3259 continue;
3260 if (ret < 0)
3261 goto out;
3262
3263 stop_loop = 1;
3264 break;
3265 }
3266 btrfs_item_key_to_cpu(l, &key, slot);
3267
3268 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3269 key.type != BTRFS_METADATA_ITEM_KEY)
3270 goto next;
3271
3272 if (key.type == BTRFS_METADATA_ITEM_KEY)
3273 bytes = fs_info->nodesize;
3274 else
3275 bytes = key.offset;
3276
3277 if (key.objectid + bytes <= logical)
3278 goto next;
3279
3280 if (key.objectid >= logical + map->stripe_len) {
3281 /* out of this device extent */
3282 if (key.objectid >= logic_end)
3283 stop_loop = 1;
3284 break;
3285 }
3286
3287 extent = btrfs_item_ptr(l, slot,
3288 struct btrfs_extent_item);
3289 flags = btrfs_extent_flags(l, extent);
3290 generation = btrfs_extent_generation(l, extent);
3291
3292 if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
3293 (key.objectid < logical ||
3294 key.objectid + bytes >
3295 logical + map->stripe_len)) {
3296 btrfs_err(fs_info,
3297 "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
3298 key.objectid, logical);
3299 spin_lock(&sctx->stat_lock);
3300 sctx->stat.uncorrectable_errors++;
3301 spin_unlock(&sctx->stat_lock);
3302 goto next;
3303 }
3304
3305again:
3306 extent_logical = key.objectid;
3307 extent_len = bytes;
3308
3309 /*
3310 * trim extent to this stripe
3311 */
3312 if (extent_logical < logical) {
3313 extent_len -= logical - extent_logical;
3314 extent_logical = logical;
3315 }
3316 if (extent_logical + extent_len >
3317 logical + map->stripe_len) {
3318 extent_len = logical + map->stripe_len -
3319 extent_logical;
3320 }
3321
3322 extent_physical = extent_logical - logical + physical;
3323 extent_dev = scrub_dev;
3324 extent_mirror_num = mirror_num;
3325 if (sctx->is_dev_replace)
3326 scrub_remap_extent(fs_info, extent_logical,
3327 extent_len, &extent_physical,
3328 &extent_dev,
3329 &extent_mirror_num);
3330
3331 ret = btrfs_lookup_csums_range(csum_root,
3332 extent_logical,
3333 extent_logical +
3334 extent_len - 1,
3335 &sctx->csum_list, 1);
3336 if (ret)
3337 goto out;
3338
3339 ret = scrub_extent(sctx, map, extent_logical, extent_len,
3340 extent_physical, extent_dev, flags,
3341 generation, extent_mirror_num,
3342 extent_logical - logical + physical);
3343
3344 scrub_free_csums(sctx);
3345
3346 if (ret)
3347 goto out;
3348
3349 if (extent_logical + extent_len <
3350 key.objectid + bytes) {
3351 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
3352 /*
3353 * loop until we find next data stripe
3354 * or we have finished all stripes.
3355 */
3356loop:
3357 physical += map->stripe_len;
3358 ret = get_raid56_logic_offset(physical,
3359 num, map, &logical,
3360 &stripe_logical);
3361 logical += base;
3362
3363 if (ret && physical < physical_end) {
3364 stripe_logical += base;
3365 stripe_end = stripe_logical +
3366 increment;
3367 ret = scrub_raid56_parity(sctx,
3368 map, scrub_dev, ppath,
3369 stripe_logical,
3370 stripe_end);
3371 if (ret)
3372 goto out;
3373 goto loop;
3374 }
3375 } else {
3376 physical += map->stripe_len;
3377 logical += increment;
3378 }
3379 if (logical < key.objectid + bytes) {
3380 cond_resched();
3381 goto again;
3382 }
3383
3384 if (physical >= physical_end) {
3385 stop_loop = 1;
3386 break;
3387 }
3388 }
3389next:
3390 path->slots[0]++;
3391 }
3392 btrfs_release_path(path);
3393skip:
3394 logical += increment;
3395 physical += map->stripe_len;
3396 spin_lock(&sctx->stat_lock);
3397 if (stop_loop)
3398 sctx->stat.last_physical = map->stripes[num].physical +
3399 length;
3400 else
3401 sctx->stat.last_physical = physical;
3402 spin_unlock(&sctx->stat_lock);
3403 if (stop_loop)
3404 break;
3405 }
3406out:
3407 /* push queued extents */
3408 scrub_submit(sctx);
3409 mutex_lock(&sctx->wr_lock);
3410 scrub_wr_submit(sctx);
3411 mutex_unlock(&sctx->wr_lock);
3412
3413 blk_finish_plug(&plug);
3414 btrfs_free_path(path);
3415 btrfs_free_path(ppath);
3416 return ret < 0 ? ret : 0;
3417}
3418
3419static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
3420 struct btrfs_device *scrub_dev,
3421 u64 chunk_offset, u64 length,
3422 u64 dev_offset,
3423 struct btrfs_block_group_cache *cache)
3424{
3425 struct btrfs_fs_info *fs_info = sctx->fs_info;
3426 struct extent_map_tree *map_tree = &fs_info->mapping_tree;
3427 struct map_lookup *map;
3428 struct extent_map *em;
3429 int i;
3430 int ret = 0;
3431
3432 read_lock(&map_tree->lock);
3433 em = lookup_extent_mapping(map_tree, chunk_offset, 1);
3434 read_unlock(&map_tree->lock);
3435
3436 if (!em) {
3437 /*
3438 * Might have been an unused block group deleted by the cleaner
3439 * kthread or relocation.
3440 */
3441 spin_lock(&cache->lock);
3442 if (!cache->removed)
3443 ret = -EINVAL;
3444 spin_unlock(&cache->lock);
3445
3446 return ret;
3447 }
3448
3449 map = em->map_lookup;
3450 if (em->start != chunk_offset)
3451 goto out;
3452
3453 if (em->len < length)
3454 goto out;
3455
3456 for (i = 0; i < map->num_stripes; ++i) {
3457 if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
3458 map->stripes[i].physical == dev_offset) {
3459 ret = scrub_stripe(sctx, map, scrub_dev, i,
3460 chunk_offset, length);
3461 if (ret)
3462 goto out;
3463 }
3464 }
3465out:
3466 free_extent_map(em);
3467
3468 return ret;
3469}
3470
3471static noinline_for_stack
3472int scrub_enumerate_chunks(struct scrub_ctx *sctx,
3473 struct btrfs_device *scrub_dev, u64 start, u64 end)
3474{
3475 struct btrfs_dev_extent *dev_extent = NULL;
3476 struct btrfs_path *path;
3477 struct btrfs_fs_info *fs_info = sctx->fs_info;
3478 struct btrfs_root *root = fs_info->dev_root;
3479 u64 length;
3480 u64 chunk_offset;
3481 int ret = 0;
3482 int ro_set;
3483 int slot;
3484 struct extent_buffer *l;
3485 struct btrfs_key key;
3486 struct btrfs_key found_key;
3487 struct btrfs_block_group_cache *cache;
3488 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
3489
3490 path = btrfs_alloc_path();
3491 if (!path)
3492 return -ENOMEM;
3493
3494 path->reada = READA_FORWARD;
3495 path->search_commit_root = 1;
3496 path->skip_locking = 1;
3497
3498 key.objectid = scrub_dev->devid;
3499 key.offset = 0ull;
3500 key.type = BTRFS_DEV_EXTENT_KEY;
3501
3502 while (1) {
3503 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3504 if (ret < 0)
3505 break;
3506 if (ret > 0) {
3507 if (path->slots[0] >=
3508 btrfs_header_nritems(path->nodes[0])) {
3509 ret = btrfs_next_leaf(root, path);
3510 if (ret < 0)
3511 break;
3512 if (ret > 0) {
3513 ret = 0;
3514 break;
3515 }
3516 } else {
3517 ret = 0;
3518 }
3519 }
3520
3521 l = path->nodes[0];
3522 slot = path->slots[0];
3523
3524 btrfs_item_key_to_cpu(l, &found_key, slot);
3525
3526 if (found_key.objectid != scrub_dev->devid)
3527 break;
3528
3529 if (found_key.type != BTRFS_DEV_EXTENT_KEY)
3530 break;
3531
3532 if (found_key.offset >= end)
3533 break;
3534
3535 if (found_key.offset < key.offset)
3536 break;
3537
3538 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3539 length = btrfs_dev_extent_length(l, dev_extent);
3540
3541 if (found_key.offset + length <= start)
3542 goto skip;
3543
3544 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3545
3546 /*
3547 * get a reference on the corresponding block group to prevent
3548 * the chunk from going away while we scrub it
3549 */
3550 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3551
3552 /* some chunks are removed but not committed to disk yet,
3553 * continue scrubbing */
3554 if (!cache)
3555 goto skip;
3556
3557 /*
3558 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
3559 * to avoid deadlock caused by:
3560 * btrfs_inc_block_group_ro()
3561 * -> btrfs_wait_for_commit()
3562 * -> btrfs_commit_transaction()
3563 * -> btrfs_scrub_pause()
3564 */
3565 scrub_pause_on(fs_info);
3566 ret = btrfs_inc_block_group_ro(cache);
3567 if (!ret && sctx->is_dev_replace) {
3568 /*
3569 * If we are doing a device replace wait for any tasks
3570 * that started delalloc right before we set the block
3571 * group to RO mode, as they might have just allocated
3572 * an extent from it or decided they could do a nocow
3573 * write. And if any such tasks did that, wait for their
3574 * ordered extents to complete and then commit the
3575 * current transaction, so that we can later see the new
3576 * extent items in the extent tree - the ordered extents
3577 * create delayed data references (for cow writes) when
3578 * they complete, which will be run and insert the
3579 * corresponding extent items into the extent tree when
3580 * we commit the transaction they used when running
3581 * inode.c:btrfs_finish_ordered_io(). We later use
3582 * the commit root of the extent tree to find extents
3583 * to copy from the srcdev into the tgtdev, and we don't
3584 * want to miss any new extents.
3585 */
3586 btrfs_wait_block_group_reservations(cache);
3587 btrfs_wait_nocow_writers(cache);
3588 ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
3589 cache->key.objectid,
3590 cache->key.offset);
3591 if (ret > 0) {
3592 struct btrfs_trans_handle *trans;
3593
3594 trans = btrfs_join_transaction(root);
3595 if (IS_ERR(trans))
3596 ret = PTR_ERR(trans);
3597 else
3598 ret = btrfs_commit_transaction(trans);
3599 if (ret) {
3600 scrub_pause_off(fs_info);
3601 btrfs_put_block_group(cache);
3602 break;
3603 }
3604 }
3605 }
3606 scrub_pause_off(fs_info);
3607
3608 if (ret == 0) {
3609 ro_set = 1;
3610 } else if (ret == -ENOSPC) {
3611 /*
3612 * btrfs_inc_block_group_ro return -ENOSPC when it
3613 * failed in creating new chunk for metadata.
3614 * It is not a problem for scrub/replace, because
3615 * metadata are always cowed, and our scrub paused
3616 * commit_transactions.
3617 */
3618 ro_set = 0;
3619 } else {
3620 btrfs_warn(fs_info,
3621 "failed setting block group ro: %d", ret);
3622 btrfs_put_block_group(cache);
3623 break;
3624 }
3625
3626 down_write(&fs_info->dev_replace.rwsem);
3627 dev_replace->cursor_right = found_key.offset + length;
3628 dev_replace->cursor_left = found_key.offset;
3629 dev_replace->item_needs_writeback = 1;
3630 up_write(&dev_replace->rwsem);
3631
3632 ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
3633 found_key.offset, cache);
3634
3635 /*
3636 * flush, submit all pending read and write bios, afterwards
3637 * wait for them.
3638 * Note that in the dev replace case, a read request causes
3639 * write requests that are submitted in the read completion
3640 * worker. Therefore in the current situation, it is required
3641 * that all write requests are flushed, so that all read and
3642 * write requests are really completed when bios_in_flight
3643 * changes to 0.
3644 */
3645 sctx->flush_all_writes = true;
3646 scrub_submit(sctx);
3647 mutex_lock(&sctx->wr_lock);
3648 scrub_wr_submit(sctx);
3649 mutex_unlock(&sctx->wr_lock);
3650
3651 wait_event(sctx->list_wait,
3652 atomic_read(&sctx->bios_in_flight) == 0);
3653
3654 scrub_pause_on(fs_info);
3655
3656 /*
3657 * must be called before we decrease @scrub_paused.
3658 * make sure we don't block transaction commit while
3659 * we are waiting pending workers finished.
3660 */
3661 wait_event(sctx->list_wait,
3662 atomic_read(&sctx->workers_pending) == 0);
3663 sctx->flush_all_writes = false;
3664
3665 scrub_pause_off(fs_info);
3666
3667 down_write(&fs_info->dev_replace.rwsem);
3668 dev_replace->cursor_left = dev_replace->cursor_right;
3669 dev_replace->item_needs_writeback = 1;
3670 up_write(&fs_info->dev_replace.rwsem);
3671
3672 if (ro_set)
3673 btrfs_dec_block_group_ro(cache);
3674
3675 /*
3676 * We might have prevented the cleaner kthread from deleting
3677 * this block group if it was already unused because we raced
3678 * and set it to RO mode first. So add it back to the unused
3679 * list, otherwise it might not ever be deleted unless a manual
3680 * balance is triggered or it becomes used and unused again.
3681 */
3682 spin_lock(&cache->lock);
3683 if (!cache->removed && !cache->ro && cache->reserved == 0 &&
3684 btrfs_block_group_used(&cache->item) == 0) {
3685 spin_unlock(&cache->lock);
3686 btrfs_mark_bg_unused(cache);
3687 } else {
3688 spin_unlock(&cache->lock);
3689 }
3690
3691 btrfs_put_block_group(cache);
3692 if (ret)
3693 break;
3694 if (sctx->is_dev_replace &&
3695 atomic64_read(&dev_replace->num_write_errors) > 0) {
3696 ret = -EIO;
3697 break;
3698 }
3699 if (sctx->stat.malloc_errors > 0) {
3700 ret = -ENOMEM;
3701 break;
3702 }
3703skip:
3704 key.offset = found_key.offset + length;
3705 btrfs_release_path(path);
3706 }
3707
3708 btrfs_free_path(path);
3709
3710 return ret;
3711}
3712
3713static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
3714 struct btrfs_device *scrub_dev)
3715{
3716 int i;
3717 u64 bytenr;
3718 u64 gen;
3719 int ret;
3720 struct btrfs_fs_info *fs_info = sctx->fs_info;
3721
3722 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3723 return -EIO;
3724
3725 /* Seed devices of a new filesystem has their own generation. */
3726 if (scrub_dev->fs_devices != fs_info->fs_devices)
3727 gen = scrub_dev->generation;
3728 else
3729 gen = fs_info->last_trans_committed;
3730
3731 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3732 bytenr = btrfs_sb_offset(i);
3733 if (bytenr + BTRFS_SUPER_INFO_SIZE >
3734 scrub_dev->commit_total_bytes)
3735 break;
3736
3737 ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
3738 scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
3739 NULL, 1, bytenr);
3740 if (ret)
3741 return ret;
3742 }
3743 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3744
3745 return 0;
3746}
3747
3748/*
3749 * get a reference count on fs_info->scrub_workers. start worker if necessary
3750 */
3751static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
3752 int is_dev_replace)
3753{
3754 unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
3755 int max_active = fs_info->thread_pool_size;
3756
3757 lockdep_assert_held(&fs_info->scrub_lock);
3758
3759 if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
3760 ASSERT(fs_info->scrub_workers == NULL);
3761 fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
3762 flags, is_dev_replace ? 1 : max_active, 4);
3763 if (!fs_info->scrub_workers)
3764 goto fail_scrub_workers;
3765
3766 ASSERT(fs_info->scrub_wr_completion_workers == NULL);
3767 fs_info->scrub_wr_completion_workers =
3768 btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
3769 max_active, 2);
3770 if (!fs_info->scrub_wr_completion_workers)
3771 goto fail_scrub_wr_completion_workers;
3772
3773 ASSERT(fs_info->scrub_parity_workers == NULL);
3774 fs_info->scrub_parity_workers =
3775 btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
3776 max_active, 2);
3777 if (!fs_info->scrub_parity_workers)
3778 goto fail_scrub_parity_workers;
3779
3780 refcount_set(&fs_info->scrub_workers_refcnt, 1);
3781 } else {
3782 refcount_inc(&fs_info->scrub_workers_refcnt);
3783 }
3784 return 0;
3785
3786fail_scrub_parity_workers:
3787 btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
3788fail_scrub_wr_completion_workers:
3789 btrfs_destroy_workqueue(fs_info->scrub_workers);
3790fail_scrub_workers:
3791 return -ENOMEM;
3792}
3793
3794int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
3795 u64 end, struct btrfs_scrub_progress *progress,
3796 int readonly, int is_dev_replace)
3797{
3798 struct scrub_ctx *sctx;
3799 int ret;
3800 struct btrfs_device *dev;
3801 unsigned int nofs_flag;
3802 struct btrfs_workqueue *scrub_workers = NULL;
3803 struct btrfs_workqueue *scrub_wr_comp = NULL;
3804 struct btrfs_workqueue *scrub_parity = NULL;
3805
3806 if (btrfs_fs_closing(fs_info))
3807 return -EAGAIN;
3808
3809 if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
3810 /*
3811 * in this case scrub is unable to calculate the checksum
3812 * the way scrub is implemented. Do not handle this
3813 * situation at all because it won't ever happen.
3814 */
3815 btrfs_err(fs_info,
3816 "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
3817 fs_info->nodesize,
3818 BTRFS_STRIPE_LEN);
3819 return -EINVAL;
3820 }
3821
3822 if (fs_info->sectorsize != PAGE_SIZE) {
3823 /* not supported for data w/o checksums */
3824 btrfs_err_rl(fs_info,
3825 "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
3826 fs_info->sectorsize, PAGE_SIZE);
3827 return -EINVAL;
3828 }
3829
3830 if (fs_info->nodesize >
3831 PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
3832 fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
3833 /*
3834 * would exhaust the array bounds of pagev member in
3835 * struct scrub_block
3836 */
3837 btrfs_err(fs_info,
3838 "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
3839 fs_info->nodesize,
3840 SCRUB_MAX_PAGES_PER_BLOCK,
3841 fs_info->sectorsize,
3842 SCRUB_MAX_PAGES_PER_BLOCK);
3843 return -EINVAL;
3844 }
3845
3846 /* Allocate outside of device_list_mutex */
3847 sctx = scrub_setup_ctx(fs_info, is_dev_replace);
3848 if (IS_ERR(sctx))
3849 return PTR_ERR(sctx);
3850
3851 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3852 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
3853 if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
3854 !is_dev_replace)) {
3855 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3856 ret = -ENODEV;
3857 goto out_free_ctx;
3858 }
3859
3860 if (!is_dev_replace && !readonly &&
3861 !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
3862 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3863 btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
3864 rcu_str_deref(dev->name));
3865 ret = -EROFS;
3866 goto out_free_ctx;
3867 }
3868
3869 mutex_lock(&fs_info->scrub_lock);
3870 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3871 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
3872 mutex_unlock(&fs_info->scrub_lock);
3873 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3874 ret = -EIO;
3875 goto out_free_ctx;
3876 }
3877
3878 down_read(&fs_info->dev_replace.rwsem);
3879 if (dev->scrub_ctx ||
3880 (!is_dev_replace &&
3881 btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
3882 up_read(&fs_info->dev_replace.rwsem);
3883 mutex_unlock(&fs_info->scrub_lock);
3884 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3885 ret = -EINPROGRESS;
3886 goto out_free_ctx;
3887 }
3888 up_read(&fs_info->dev_replace.rwsem);
3889
3890 ret = scrub_workers_get(fs_info, is_dev_replace);
3891 if (ret) {
3892 mutex_unlock(&fs_info->scrub_lock);
3893 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3894 goto out_free_ctx;
3895 }
3896
3897 sctx->readonly = readonly;
3898 dev->scrub_ctx = sctx;
3899 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3900
3901 /*
3902 * checking @scrub_pause_req here, we can avoid
3903 * race between committing transaction and scrubbing.
3904 */
3905 __scrub_blocked_if_needed(fs_info);
3906 atomic_inc(&fs_info->scrubs_running);
3907 mutex_unlock(&fs_info->scrub_lock);
3908
3909 /*
3910 * In order to avoid deadlock with reclaim when there is a transaction
3911 * trying to pause scrub, make sure we use GFP_NOFS for all the
3912 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
3913 * invoked by our callees. The pausing request is done when the
3914 * transaction commit starts, and it blocks the transaction until scrub
3915 * is paused (done at specific points at scrub_stripe() or right above
3916 * before incrementing fs_info->scrubs_running).
3917 */
3918 nofs_flag = memalloc_nofs_save();
3919 if (!is_dev_replace) {
3920 btrfs_info(fs_info, "scrub: started on devid %llu", devid);
3921 /*
3922 * by holding device list mutex, we can
3923 * kick off writing super in log tree sync.
3924 */
3925 mutex_lock(&fs_info->fs_devices->device_list_mutex);
3926 ret = scrub_supers(sctx, dev);
3927 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
3928 }
3929
3930 if (!ret)
3931 ret = scrub_enumerate_chunks(sctx, dev, start, end);
3932 memalloc_nofs_restore(nofs_flag);
3933
3934 wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
3935 atomic_dec(&fs_info->scrubs_running);
3936 wake_up(&fs_info->scrub_pause_wait);
3937
3938 wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
3939
3940 if (progress)
3941 memcpy(progress, &sctx->stat, sizeof(*progress));
3942
3943 if (!is_dev_replace)
3944 btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
3945 ret ? "not finished" : "finished", devid, ret);
3946
3947 mutex_lock(&fs_info->scrub_lock);
3948 dev->scrub_ctx = NULL;
3949 if (refcount_dec_and_test(&fs_info->scrub_workers_refcnt)) {
3950 scrub_workers = fs_info->scrub_workers;
3951 scrub_wr_comp = fs_info->scrub_wr_completion_workers;
3952 scrub_parity = fs_info->scrub_parity_workers;
3953
3954 fs_info->scrub_workers = NULL;
3955 fs_info->scrub_wr_completion_workers = NULL;
3956 fs_info->scrub_parity_workers = NULL;
3957 }
3958 mutex_unlock(&fs_info->scrub_lock);
3959
3960 btrfs_destroy_workqueue(scrub_workers);
3961 btrfs_destroy_workqueue(scrub_wr_comp);
3962 btrfs_destroy_workqueue(scrub_parity);
3963 scrub_put_ctx(sctx);
3964
3965 return ret;
3966
3967out_free_ctx:
3968 scrub_free_ctx(sctx);
3969
3970 return ret;
3971}
3972
3973void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
3974{
3975 mutex_lock(&fs_info->scrub_lock);
3976 atomic_inc(&fs_info->scrub_pause_req);
3977 while (atomic_read(&fs_info->scrubs_paused) !=
3978 atomic_read(&fs_info->scrubs_running)) {
3979 mutex_unlock(&fs_info->scrub_lock);
3980 wait_event(fs_info->scrub_pause_wait,
3981 atomic_read(&fs_info->scrubs_paused) ==
3982 atomic_read(&fs_info->scrubs_running));
3983 mutex_lock(&fs_info->scrub_lock);
3984 }
3985 mutex_unlock(&fs_info->scrub_lock);
3986}
3987
3988void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
3989{
3990 atomic_dec(&fs_info->scrub_pause_req);
3991 wake_up(&fs_info->scrub_pause_wait);
3992}
3993
3994int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
3995{
3996 mutex_lock(&fs_info->scrub_lock);
3997 if (!atomic_read(&fs_info->scrubs_running)) {
3998 mutex_unlock(&fs_info->scrub_lock);
3999 return -ENOTCONN;
4000 }
4001
4002 atomic_inc(&fs_info->scrub_cancel_req);
4003 while (atomic_read(&fs_info->scrubs_running)) {
4004 mutex_unlock(&fs_info->scrub_lock);
4005 wait_event(fs_info->scrub_pause_wait,
4006 atomic_read(&fs_info->scrubs_running) == 0);
4007 mutex_lock(&fs_info->scrub_lock);
4008 }
4009 atomic_dec(&fs_info->scrub_cancel_req);
4010 mutex_unlock(&fs_info->scrub_lock);
4011
4012 return 0;
4013}
4014
4015int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
4016{
4017 struct btrfs_fs_info *fs_info = dev->fs_info;
4018 struct scrub_ctx *sctx;
4019
4020 mutex_lock(&fs_info->scrub_lock);
4021 sctx = dev->scrub_ctx;
4022 if (!sctx) {
4023 mutex_unlock(&fs_info->scrub_lock);
4024 return -ENOTCONN;
4025 }
4026 atomic_inc(&sctx->cancel_req);
4027 while (dev->scrub_ctx) {
4028 mutex_unlock(&fs_info->scrub_lock);
4029 wait_event(fs_info->scrub_pause_wait,
4030 dev->scrub_ctx == NULL);
4031 mutex_lock(&fs_info->scrub_lock);
4032 }
4033 mutex_unlock(&fs_info->scrub_lock);
4034
4035 return 0;
4036}
4037
4038int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
4039 struct btrfs_scrub_progress *progress)
4040{
4041 struct btrfs_device *dev;
4042 struct scrub_ctx *sctx = NULL;
4043
4044 mutex_lock(&fs_info->fs_devices->device_list_mutex);
4045 dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
4046 if (dev)
4047 sctx = dev->scrub_ctx;
4048 if (sctx)
4049 memcpy(progress, &sctx->stat, sizeof(*progress));
4050 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4051
4052 return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
4053}
4054
4055static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
4056 u64 extent_logical, u64 extent_len,
4057 u64 *extent_physical,
4058 struct btrfs_device **extent_dev,
4059 int *extent_mirror_num)
4060{
4061 u64 mapped_length;
4062 struct btrfs_bio *bbio = NULL;
4063 int ret;
4064
4065 mapped_length = extent_len;
4066 ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
4067 &mapped_length, &bbio, 0);
4068 if (ret || !bbio || mapped_length < extent_len ||
4069 !bbio->stripes[0].dev->bdev) {
4070 btrfs_put_bbio(bbio);
4071 return;
4072 }
4073
4074 *extent_physical = bbio->stripes[0].physical;
4075 *extent_mirror_num = bbio->mirror_num;
4076 *extent_dev = bbio->stripes[0].dev;
4077 btrfs_put_bbio(bbio);
4078}
1/*
2 * Copyright (C) 2011 STRATO. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/blkdev.h>
20#include <linux/ratelimit.h>
21#include "ctree.h"
22#include "volumes.h"
23#include "disk-io.h"
24#include "ordered-data.h"
25#include "transaction.h"
26#include "backref.h"
27#include "extent_io.h"
28#include "check-integrity.h"
29#include "rcu-string.h"
30
31/*
32 * This is only the first step towards a full-features scrub. It reads all
33 * extent and super block and verifies the checksums. In case a bad checksum
34 * is found or the extent cannot be read, good data will be written back if
35 * any can be found.
36 *
37 * Future enhancements:
38 * - In case an unrepairable extent is encountered, track which files are
39 * affected and report them
40 * - track and record media errors, throw out bad devices
41 * - add a mode to also read unallocated space
42 */
43
44struct scrub_block;
45struct scrub_dev;
46
47#define SCRUB_PAGES_PER_BIO 16 /* 64k per bio */
48#define SCRUB_BIOS_PER_DEV 16 /* 1 MB per device in flight */
49#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
50
51struct scrub_page {
52 struct scrub_block *sblock;
53 struct page *page;
54 struct btrfs_device *dev;
55 u64 flags; /* extent flags */
56 u64 generation;
57 u64 logical;
58 u64 physical;
59 struct {
60 unsigned int mirror_num:8;
61 unsigned int have_csum:1;
62 unsigned int io_error:1;
63 };
64 u8 csum[BTRFS_CSUM_SIZE];
65};
66
67struct scrub_bio {
68 int index;
69 struct scrub_dev *sdev;
70 struct bio *bio;
71 int err;
72 u64 logical;
73 u64 physical;
74 struct scrub_page *pagev[SCRUB_PAGES_PER_BIO];
75 int page_count;
76 int next_free;
77 struct btrfs_work work;
78};
79
80struct scrub_block {
81 struct scrub_page pagev[SCRUB_MAX_PAGES_PER_BLOCK];
82 int page_count;
83 atomic_t outstanding_pages;
84 atomic_t ref_count; /* free mem on transition to zero */
85 struct scrub_dev *sdev;
86 struct {
87 unsigned int header_error:1;
88 unsigned int checksum_error:1;
89 unsigned int no_io_error_seen:1;
90 unsigned int generation_error:1; /* also sets header_error */
91 };
92};
93
94struct scrub_dev {
95 struct scrub_bio *bios[SCRUB_BIOS_PER_DEV];
96 struct btrfs_device *dev;
97 int first_free;
98 int curr;
99 atomic_t in_flight;
100 atomic_t fixup_cnt;
101 spinlock_t list_lock;
102 wait_queue_head_t list_wait;
103 u16 csum_size;
104 struct list_head csum_list;
105 atomic_t cancel_req;
106 int readonly;
107 int pages_per_bio; /* <= SCRUB_PAGES_PER_BIO */
108 u32 sectorsize;
109 u32 nodesize;
110 u32 leafsize;
111 /*
112 * statistics
113 */
114 struct btrfs_scrub_progress stat;
115 spinlock_t stat_lock;
116};
117
118struct scrub_fixup_nodatasum {
119 struct scrub_dev *sdev;
120 u64 logical;
121 struct btrfs_root *root;
122 struct btrfs_work work;
123 int mirror_num;
124};
125
126struct scrub_warning {
127 struct btrfs_path *path;
128 u64 extent_item_size;
129 char *scratch_buf;
130 char *msg_buf;
131 const char *errstr;
132 sector_t sector;
133 u64 logical;
134 struct btrfs_device *dev;
135 int msg_bufsize;
136 int scratch_bufsize;
137};
138
139
140static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
141static int scrub_setup_recheck_block(struct scrub_dev *sdev,
142 struct btrfs_mapping_tree *map_tree,
143 u64 length, u64 logical,
144 struct scrub_block *sblock);
145static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
146 struct scrub_block *sblock, int is_metadata,
147 int have_csum, u8 *csum, u64 generation,
148 u16 csum_size);
149static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
150 struct scrub_block *sblock,
151 int is_metadata, int have_csum,
152 const u8 *csum, u64 generation,
153 u16 csum_size);
154static void scrub_complete_bio_end_io(struct bio *bio, int err);
155static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
156 struct scrub_block *sblock_good,
157 int force_write);
158static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
159 struct scrub_block *sblock_good,
160 int page_num, int force_write);
161static int scrub_checksum_data(struct scrub_block *sblock);
162static int scrub_checksum_tree_block(struct scrub_block *sblock);
163static int scrub_checksum_super(struct scrub_block *sblock);
164static void scrub_block_get(struct scrub_block *sblock);
165static void scrub_block_put(struct scrub_block *sblock);
166static int scrub_add_page_to_bio(struct scrub_dev *sdev,
167 struct scrub_page *spage);
168static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len,
169 u64 physical, u64 flags, u64 gen, int mirror_num,
170 u8 *csum, int force);
171static void scrub_bio_end_io(struct bio *bio, int err);
172static void scrub_bio_end_io_worker(struct btrfs_work *work);
173static void scrub_block_complete(struct scrub_block *sblock);
174
175
176static void scrub_free_csums(struct scrub_dev *sdev)
177{
178 while (!list_empty(&sdev->csum_list)) {
179 struct btrfs_ordered_sum *sum;
180 sum = list_first_entry(&sdev->csum_list,
181 struct btrfs_ordered_sum, list);
182 list_del(&sum->list);
183 kfree(sum);
184 }
185}
186
187static noinline_for_stack void scrub_free_dev(struct scrub_dev *sdev)
188{
189 int i;
190
191 if (!sdev)
192 return;
193
194 /* this can happen when scrub is cancelled */
195 if (sdev->curr != -1) {
196 struct scrub_bio *sbio = sdev->bios[sdev->curr];
197
198 for (i = 0; i < sbio->page_count; i++) {
199 BUG_ON(!sbio->pagev[i]);
200 BUG_ON(!sbio->pagev[i]->page);
201 scrub_block_put(sbio->pagev[i]->sblock);
202 }
203 bio_put(sbio->bio);
204 }
205
206 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
207 struct scrub_bio *sbio = sdev->bios[i];
208
209 if (!sbio)
210 break;
211 kfree(sbio);
212 }
213
214 scrub_free_csums(sdev);
215 kfree(sdev);
216}
217
218static noinline_for_stack
219struct scrub_dev *scrub_setup_dev(struct btrfs_device *dev)
220{
221 struct scrub_dev *sdev;
222 int i;
223 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
224 int pages_per_bio;
225
226 pages_per_bio = min_t(int, SCRUB_PAGES_PER_BIO,
227 bio_get_nr_vecs(dev->bdev));
228 sdev = kzalloc(sizeof(*sdev), GFP_NOFS);
229 if (!sdev)
230 goto nomem;
231 sdev->dev = dev;
232 sdev->pages_per_bio = pages_per_bio;
233 sdev->curr = -1;
234 for (i = 0; i < SCRUB_BIOS_PER_DEV; ++i) {
235 struct scrub_bio *sbio;
236
237 sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
238 if (!sbio)
239 goto nomem;
240 sdev->bios[i] = sbio;
241
242 sbio->index = i;
243 sbio->sdev = sdev;
244 sbio->page_count = 0;
245 sbio->work.func = scrub_bio_end_io_worker;
246
247 if (i != SCRUB_BIOS_PER_DEV-1)
248 sdev->bios[i]->next_free = i + 1;
249 else
250 sdev->bios[i]->next_free = -1;
251 }
252 sdev->first_free = 0;
253 sdev->nodesize = dev->dev_root->nodesize;
254 sdev->leafsize = dev->dev_root->leafsize;
255 sdev->sectorsize = dev->dev_root->sectorsize;
256 atomic_set(&sdev->in_flight, 0);
257 atomic_set(&sdev->fixup_cnt, 0);
258 atomic_set(&sdev->cancel_req, 0);
259 sdev->csum_size = btrfs_super_csum_size(fs_info->super_copy);
260 INIT_LIST_HEAD(&sdev->csum_list);
261
262 spin_lock_init(&sdev->list_lock);
263 spin_lock_init(&sdev->stat_lock);
264 init_waitqueue_head(&sdev->list_wait);
265 return sdev;
266
267nomem:
268 scrub_free_dev(sdev);
269 return ERR_PTR(-ENOMEM);
270}
271
272static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
273{
274 u64 isize;
275 u32 nlink;
276 int ret;
277 int i;
278 struct extent_buffer *eb;
279 struct btrfs_inode_item *inode_item;
280 struct scrub_warning *swarn = ctx;
281 struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
282 struct inode_fs_paths *ipath = NULL;
283 struct btrfs_root *local_root;
284 struct btrfs_key root_key;
285
286 root_key.objectid = root;
287 root_key.type = BTRFS_ROOT_ITEM_KEY;
288 root_key.offset = (u64)-1;
289 local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
290 if (IS_ERR(local_root)) {
291 ret = PTR_ERR(local_root);
292 goto err;
293 }
294
295 ret = inode_item_info(inum, 0, local_root, swarn->path);
296 if (ret) {
297 btrfs_release_path(swarn->path);
298 goto err;
299 }
300
301 eb = swarn->path->nodes[0];
302 inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
303 struct btrfs_inode_item);
304 isize = btrfs_inode_size(eb, inode_item);
305 nlink = btrfs_inode_nlink(eb, inode_item);
306 btrfs_release_path(swarn->path);
307
308 ipath = init_ipath(4096, local_root, swarn->path);
309 if (IS_ERR(ipath)) {
310 ret = PTR_ERR(ipath);
311 ipath = NULL;
312 goto err;
313 }
314 ret = paths_from_inode(inum, ipath);
315
316 if (ret < 0)
317 goto err;
318
319 /*
320 * we deliberately ignore the bit ipath might have been too small to
321 * hold all of the paths here
322 */
323 for (i = 0; i < ipath->fspath->elem_cnt; ++i)
324 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
325 "%s, sector %llu, root %llu, inode %llu, offset %llu, "
326 "length %llu, links %u (path: %s)\n", swarn->errstr,
327 swarn->logical, rcu_str_deref(swarn->dev->name),
328 (unsigned long long)swarn->sector, root, inum, offset,
329 min(isize - offset, (u64)PAGE_SIZE), nlink,
330 (char *)(unsigned long)ipath->fspath->val[i]);
331
332 free_ipath(ipath);
333 return 0;
334
335err:
336 printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
337 "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
338 "resolving failed with ret=%d\n", swarn->errstr,
339 swarn->logical, rcu_str_deref(swarn->dev->name),
340 (unsigned long long)swarn->sector, root, inum, offset, ret);
341
342 free_ipath(ipath);
343 return 0;
344}
345
346static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
347{
348 struct btrfs_device *dev = sblock->sdev->dev;
349 struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
350 struct btrfs_path *path;
351 struct btrfs_key found_key;
352 struct extent_buffer *eb;
353 struct btrfs_extent_item *ei;
354 struct scrub_warning swarn;
355 u32 item_size;
356 int ret;
357 u64 ref_root;
358 u8 ref_level;
359 unsigned long ptr = 0;
360 const int bufsize = 4096;
361 u64 extent_item_pos;
362
363 path = btrfs_alloc_path();
364
365 swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
366 swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
367 BUG_ON(sblock->page_count < 1);
368 swarn.sector = (sblock->pagev[0].physical) >> 9;
369 swarn.logical = sblock->pagev[0].logical;
370 swarn.errstr = errstr;
371 swarn.dev = dev;
372 swarn.msg_bufsize = bufsize;
373 swarn.scratch_bufsize = bufsize;
374
375 if (!path || !swarn.scratch_buf || !swarn.msg_buf)
376 goto out;
377
378 ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
379 if (ret < 0)
380 goto out;
381
382 extent_item_pos = swarn.logical - found_key.objectid;
383 swarn.extent_item_size = found_key.offset;
384
385 eb = path->nodes[0];
386 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
387 item_size = btrfs_item_size_nr(eb, path->slots[0]);
388 btrfs_release_path(path);
389
390 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
391 do {
392 ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
393 &ref_root, &ref_level);
394 printk_in_rcu(KERN_WARNING
395 "btrfs: %s at logical %llu on dev %s, "
396 "sector %llu: metadata %s (level %d) in tree "
397 "%llu\n", errstr, swarn.logical,
398 rcu_str_deref(dev->name),
399 (unsigned long long)swarn.sector,
400 ref_level ? "node" : "leaf",
401 ret < 0 ? -1 : ref_level,
402 ret < 0 ? -1 : ref_root);
403 } while (ret != 1);
404 } else {
405 swarn.path = path;
406 iterate_extent_inodes(fs_info, found_key.objectid,
407 extent_item_pos, 1,
408 scrub_print_warning_inode, &swarn);
409 }
410
411out:
412 btrfs_free_path(path);
413 kfree(swarn.scratch_buf);
414 kfree(swarn.msg_buf);
415}
416
417static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *ctx)
418{
419 struct page *page = NULL;
420 unsigned long index;
421 struct scrub_fixup_nodatasum *fixup = ctx;
422 int ret;
423 int corrected = 0;
424 struct btrfs_key key;
425 struct inode *inode = NULL;
426 u64 end = offset + PAGE_SIZE - 1;
427 struct btrfs_root *local_root;
428
429 key.objectid = root;
430 key.type = BTRFS_ROOT_ITEM_KEY;
431 key.offset = (u64)-1;
432 local_root = btrfs_read_fs_root_no_name(fixup->root->fs_info, &key);
433 if (IS_ERR(local_root))
434 return PTR_ERR(local_root);
435
436 key.type = BTRFS_INODE_ITEM_KEY;
437 key.objectid = inum;
438 key.offset = 0;
439 inode = btrfs_iget(fixup->root->fs_info->sb, &key, local_root, NULL);
440 if (IS_ERR(inode))
441 return PTR_ERR(inode);
442
443 index = offset >> PAGE_CACHE_SHIFT;
444
445 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
446 if (!page) {
447 ret = -ENOMEM;
448 goto out;
449 }
450
451 if (PageUptodate(page)) {
452 struct btrfs_mapping_tree *map_tree;
453 if (PageDirty(page)) {
454 /*
455 * we need to write the data to the defect sector. the
456 * data that was in that sector is not in memory,
457 * because the page was modified. we must not write the
458 * modified page to that sector.
459 *
460 * TODO: what could be done here: wait for the delalloc
461 * runner to write out that page (might involve
462 * COW) and see whether the sector is still
463 * referenced afterwards.
464 *
465 * For the meantime, we'll treat this error
466 * incorrectable, although there is a chance that a
467 * later scrub will find the bad sector again and that
468 * there's no dirty page in memory, then.
469 */
470 ret = -EIO;
471 goto out;
472 }
473 map_tree = &BTRFS_I(inode)->root->fs_info->mapping_tree;
474 ret = repair_io_failure(map_tree, offset, PAGE_SIZE,
475 fixup->logical, page,
476 fixup->mirror_num);
477 unlock_page(page);
478 corrected = !ret;
479 } else {
480 /*
481 * we need to get good data first. the general readpage path
482 * will call repair_io_failure for us, we just have to make
483 * sure we read the bad mirror.
484 */
485 ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
486 EXTENT_DAMAGED, GFP_NOFS);
487 if (ret) {
488 /* set_extent_bits should give proper error */
489 WARN_ON(ret > 0);
490 if (ret > 0)
491 ret = -EFAULT;
492 goto out;
493 }
494
495 ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
496 btrfs_get_extent,
497 fixup->mirror_num);
498 wait_on_page_locked(page);
499
500 corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
501 end, EXTENT_DAMAGED, 0, NULL);
502 if (!corrected)
503 clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
504 EXTENT_DAMAGED, GFP_NOFS);
505 }
506
507out:
508 if (page)
509 put_page(page);
510 if (inode)
511 iput(inode);
512
513 if (ret < 0)
514 return ret;
515
516 if (ret == 0 && corrected) {
517 /*
518 * we only need to call readpage for one of the inodes belonging
519 * to this extent. so make iterate_extent_inodes stop
520 */
521 return 1;
522 }
523
524 return -EIO;
525}
526
527static void scrub_fixup_nodatasum(struct btrfs_work *work)
528{
529 int ret;
530 struct scrub_fixup_nodatasum *fixup;
531 struct scrub_dev *sdev;
532 struct btrfs_trans_handle *trans = NULL;
533 struct btrfs_fs_info *fs_info;
534 struct btrfs_path *path;
535 int uncorrectable = 0;
536
537 fixup = container_of(work, struct scrub_fixup_nodatasum, work);
538 sdev = fixup->sdev;
539 fs_info = fixup->root->fs_info;
540
541 path = btrfs_alloc_path();
542 if (!path) {
543 spin_lock(&sdev->stat_lock);
544 ++sdev->stat.malloc_errors;
545 spin_unlock(&sdev->stat_lock);
546 uncorrectable = 1;
547 goto out;
548 }
549
550 trans = btrfs_join_transaction(fixup->root);
551 if (IS_ERR(trans)) {
552 uncorrectable = 1;
553 goto out;
554 }
555
556 /*
557 * the idea is to trigger a regular read through the standard path. we
558 * read a page from the (failed) logical address by specifying the
559 * corresponding copynum of the failed sector. thus, that readpage is
560 * expected to fail.
561 * that is the point where on-the-fly error correction will kick in
562 * (once it's finished) and rewrite the failed sector if a good copy
563 * can be found.
564 */
565 ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
566 path, scrub_fixup_readpage,
567 fixup);
568 if (ret < 0) {
569 uncorrectable = 1;
570 goto out;
571 }
572 WARN_ON(ret != 1);
573
574 spin_lock(&sdev->stat_lock);
575 ++sdev->stat.corrected_errors;
576 spin_unlock(&sdev->stat_lock);
577
578out:
579 if (trans && !IS_ERR(trans))
580 btrfs_end_transaction(trans, fixup->root);
581 if (uncorrectable) {
582 spin_lock(&sdev->stat_lock);
583 ++sdev->stat.uncorrectable_errors;
584 spin_unlock(&sdev->stat_lock);
585
586 printk_ratelimited_in_rcu(KERN_ERR
587 "btrfs: unable to fixup (nodatasum) error at logical %llu on dev %s\n",
588 (unsigned long long)fixup->logical,
589 rcu_str_deref(sdev->dev->name));
590 }
591
592 btrfs_free_path(path);
593 kfree(fixup);
594
595 /* see caller why we're pretending to be paused in the scrub counters */
596 mutex_lock(&fs_info->scrub_lock);
597 atomic_dec(&fs_info->scrubs_running);
598 atomic_dec(&fs_info->scrubs_paused);
599 mutex_unlock(&fs_info->scrub_lock);
600 atomic_dec(&sdev->fixup_cnt);
601 wake_up(&fs_info->scrub_pause_wait);
602 wake_up(&sdev->list_wait);
603}
604
605/*
606 * scrub_handle_errored_block gets called when either verification of the
607 * pages failed or the bio failed to read, e.g. with EIO. In the latter
608 * case, this function handles all pages in the bio, even though only one
609 * may be bad.
610 * The goal of this function is to repair the errored block by using the
611 * contents of one of the mirrors.
612 */
613static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
614{
615 struct scrub_dev *sdev = sblock_to_check->sdev;
616 struct btrfs_fs_info *fs_info;
617 u64 length;
618 u64 logical;
619 u64 generation;
620 unsigned int failed_mirror_index;
621 unsigned int is_metadata;
622 unsigned int have_csum;
623 u8 *csum;
624 struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
625 struct scrub_block *sblock_bad;
626 int ret;
627 int mirror_index;
628 int page_num;
629 int success;
630 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
631 DEFAULT_RATELIMIT_BURST);
632
633 BUG_ON(sblock_to_check->page_count < 1);
634 fs_info = sdev->dev->dev_root->fs_info;
635 length = sblock_to_check->page_count * PAGE_SIZE;
636 logical = sblock_to_check->pagev[0].logical;
637 generation = sblock_to_check->pagev[0].generation;
638 BUG_ON(sblock_to_check->pagev[0].mirror_num < 1);
639 failed_mirror_index = sblock_to_check->pagev[0].mirror_num - 1;
640 is_metadata = !(sblock_to_check->pagev[0].flags &
641 BTRFS_EXTENT_FLAG_DATA);
642 have_csum = sblock_to_check->pagev[0].have_csum;
643 csum = sblock_to_check->pagev[0].csum;
644
645 /*
646 * read all mirrors one after the other. This includes to
647 * re-read the extent or metadata block that failed (that was
648 * the cause that this fixup code is called) another time,
649 * page by page this time in order to know which pages
650 * caused I/O errors and which ones are good (for all mirrors).
651 * It is the goal to handle the situation when more than one
652 * mirror contains I/O errors, but the errors do not
653 * overlap, i.e. the data can be repaired by selecting the
654 * pages from those mirrors without I/O error on the
655 * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
656 * would be that mirror #1 has an I/O error on the first page,
657 * the second page is good, and mirror #2 has an I/O error on
658 * the second page, but the first page is good.
659 * Then the first page of the first mirror can be repaired by
660 * taking the first page of the second mirror, and the
661 * second page of the second mirror can be repaired by
662 * copying the contents of the 2nd page of the 1st mirror.
663 * One more note: if the pages of one mirror contain I/O
664 * errors, the checksum cannot be verified. In order to get
665 * the best data for repairing, the first attempt is to find
666 * a mirror without I/O errors and with a validated checksum.
667 * Only if this is not possible, the pages are picked from
668 * mirrors with I/O errors without considering the checksum.
669 * If the latter is the case, at the end, the checksum of the
670 * repaired area is verified in order to correctly maintain
671 * the statistics.
672 */
673
674 sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
675 sizeof(*sblocks_for_recheck),
676 GFP_NOFS);
677 if (!sblocks_for_recheck) {
678 spin_lock(&sdev->stat_lock);
679 sdev->stat.malloc_errors++;
680 sdev->stat.read_errors++;
681 sdev->stat.uncorrectable_errors++;
682 spin_unlock(&sdev->stat_lock);
683 btrfs_dev_stat_inc_and_print(sdev->dev,
684 BTRFS_DEV_STAT_READ_ERRS);
685 goto out;
686 }
687
688 /* setup the context, map the logical blocks and alloc the pages */
689 ret = scrub_setup_recheck_block(sdev, &fs_info->mapping_tree, length,
690 logical, sblocks_for_recheck);
691 if (ret) {
692 spin_lock(&sdev->stat_lock);
693 sdev->stat.read_errors++;
694 sdev->stat.uncorrectable_errors++;
695 spin_unlock(&sdev->stat_lock);
696 btrfs_dev_stat_inc_and_print(sdev->dev,
697 BTRFS_DEV_STAT_READ_ERRS);
698 goto out;
699 }
700 BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
701 sblock_bad = sblocks_for_recheck + failed_mirror_index;
702
703 /* build and submit the bios for the failed mirror, check checksums */
704 ret = scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
705 csum, generation, sdev->csum_size);
706 if (ret) {
707 spin_lock(&sdev->stat_lock);
708 sdev->stat.read_errors++;
709 sdev->stat.uncorrectable_errors++;
710 spin_unlock(&sdev->stat_lock);
711 btrfs_dev_stat_inc_and_print(sdev->dev,
712 BTRFS_DEV_STAT_READ_ERRS);
713 goto out;
714 }
715
716 if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
717 sblock_bad->no_io_error_seen) {
718 /*
719 * the error disappeared after reading page by page, or
720 * the area was part of a huge bio and other parts of the
721 * bio caused I/O errors, or the block layer merged several
722 * read requests into one and the error is caused by a
723 * different bio (usually one of the two latter cases is
724 * the cause)
725 */
726 spin_lock(&sdev->stat_lock);
727 sdev->stat.unverified_errors++;
728 spin_unlock(&sdev->stat_lock);
729
730 goto out;
731 }
732
733 if (!sblock_bad->no_io_error_seen) {
734 spin_lock(&sdev->stat_lock);
735 sdev->stat.read_errors++;
736 spin_unlock(&sdev->stat_lock);
737 if (__ratelimit(&_rs))
738 scrub_print_warning("i/o error", sblock_to_check);
739 btrfs_dev_stat_inc_and_print(sdev->dev,
740 BTRFS_DEV_STAT_READ_ERRS);
741 } else if (sblock_bad->checksum_error) {
742 spin_lock(&sdev->stat_lock);
743 sdev->stat.csum_errors++;
744 spin_unlock(&sdev->stat_lock);
745 if (__ratelimit(&_rs))
746 scrub_print_warning("checksum error", sblock_to_check);
747 btrfs_dev_stat_inc_and_print(sdev->dev,
748 BTRFS_DEV_STAT_CORRUPTION_ERRS);
749 } else if (sblock_bad->header_error) {
750 spin_lock(&sdev->stat_lock);
751 sdev->stat.verify_errors++;
752 spin_unlock(&sdev->stat_lock);
753 if (__ratelimit(&_rs))
754 scrub_print_warning("checksum/header error",
755 sblock_to_check);
756 if (sblock_bad->generation_error)
757 btrfs_dev_stat_inc_and_print(sdev->dev,
758 BTRFS_DEV_STAT_GENERATION_ERRS);
759 else
760 btrfs_dev_stat_inc_and_print(sdev->dev,
761 BTRFS_DEV_STAT_CORRUPTION_ERRS);
762 }
763
764 if (sdev->readonly)
765 goto did_not_correct_error;
766
767 if (!is_metadata && !have_csum) {
768 struct scrub_fixup_nodatasum *fixup_nodatasum;
769
770 /*
771 * !is_metadata and !have_csum, this means that the data
772 * might not be COW'ed, that it might be modified
773 * concurrently. The general strategy to work on the
774 * commit root does not help in the case when COW is not
775 * used.
776 */
777 fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
778 if (!fixup_nodatasum)
779 goto did_not_correct_error;
780 fixup_nodatasum->sdev = sdev;
781 fixup_nodatasum->logical = logical;
782 fixup_nodatasum->root = fs_info->extent_root;
783 fixup_nodatasum->mirror_num = failed_mirror_index + 1;
784 /*
785 * increment scrubs_running to prevent cancel requests from
786 * completing as long as a fixup worker is running. we must also
787 * increment scrubs_paused to prevent deadlocking on pause
788 * requests used for transactions commits (as the worker uses a
789 * transaction context). it is safe to regard the fixup worker
790 * as paused for all matters practical. effectively, we only
791 * avoid cancellation requests from completing.
792 */
793 mutex_lock(&fs_info->scrub_lock);
794 atomic_inc(&fs_info->scrubs_running);
795 atomic_inc(&fs_info->scrubs_paused);
796 mutex_unlock(&fs_info->scrub_lock);
797 atomic_inc(&sdev->fixup_cnt);
798 fixup_nodatasum->work.func = scrub_fixup_nodatasum;
799 btrfs_queue_worker(&fs_info->scrub_workers,
800 &fixup_nodatasum->work);
801 goto out;
802 }
803
804 /*
805 * now build and submit the bios for the other mirrors, check
806 * checksums
807 */
808 for (mirror_index = 0;
809 mirror_index < BTRFS_MAX_MIRRORS &&
810 sblocks_for_recheck[mirror_index].page_count > 0;
811 mirror_index++) {
812 if (mirror_index == failed_mirror_index)
813 continue;
814
815 /* build and submit the bios, check checksums */
816 ret = scrub_recheck_block(fs_info,
817 sblocks_for_recheck + mirror_index,
818 is_metadata, have_csum, csum,
819 generation, sdev->csum_size);
820 if (ret)
821 goto did_not_correct_error;
822 }
823
824 /*
825 * first try to pick the mirror which is completely without I/O
826 * errors and also does not have a checksum error.
827 * If one is found, and if a checksum is present, the full block
828 * that is known to contain an error is rewritten. Afterwards
829 * the block is known to be corrected.
830 * If a mirror is found which is completely correct, and no
831 * checksum is present, only those pages are rewritten that had
832 * an I/O error in the block to be repaired, since it cannot be
833 * determined, which copy of the other pages is better (and it
834 * could happen otherwise that a correct page would be
835 * overwritten by a bad one).
836 */
837 for (mirror_index = 0;
838 mirror_index < BTRFS_MAX_MIRRORS &&
839 sblocks_for_recheck[mirror_index].page_count > 0;
840 mirror_index++) {
841 struct scrub_block *sblock_other = sblocks_for_recheck +
842 mirror_index;
843
844 if (!sblock_other->header_error &&
845 !sblock_other->checksum_error &&
846 sblock_other->no_io_error_seen) {
847 int force_write = is_metadata || have_csum;
848
849 ret = scrub_repair_block_from_good_copy(sblock_bad,
850 sblock_other,
851 force_write);
852 if (0 == ret)
853 goto corrected_error;
854 }
855 }
856
857 /*
858 * in case of I/O errors in the area that is supposed to be
859 * repaired, continue by picking good copies of those pages.
860 * Select the good pages from mirrors to rewrite bad pages from
861 * the area to fix. Afterwards verify the checksum of the block
862 * that is supposed to be repaired. This verification step is
863 * only done for the purpose of statistic counting and for the
864 * final scrub report, whether errors remain.
865 * A perfect algorithm could make use of the checksum and try
866 * all possible combinations of pages from the different mirrors
867 * until the checksum verification succeeds. For example, when
868 * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
869 * of mirror #2 is readable but the final checksum test fails,
870 * then the 2nd page of mirror #3 could be tried, whether now
871 * the final checksum succeedes. But this would be a rare
872 * exception and is therefore not implemented. At least it is
873 * avoided that the good copy is overwritten.
874 * A more useful improvement would be to pick the sectors
875 * without I/O error based on sector sizes (512 bytes on legacy
876 * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
877 * mirror could be repaired by taking 512 byte of a different
878 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
879 * area are unreadable.
880 */
881
882 /* can only fix I/O errors from here on */
883 if (sblock_bad->no_io_error_seen)
884 goto did_not_correct_error;
885
886 success = 1;
887 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
888 struct scrub_page *page_bad = sblock_bad->pagev + page_num;
889
890 if (!page_bad->io_error)
891 continue;
892
893 for (mirror_index = 0;
894 mirror_index < BTRFS_MAX_MIRRORS &&
895 sblocks_for_recheck[mirror_index].page_count > 0;
896 mirror_index++) {
897 struct scrub_block *sblock_other = sblocks_for_recheck +
898 mirror_index;
899 struct scrub_page *page_other = sblock_other->pagev +
900 page_num;
901
902 if (!page_other->io_error) {
903 ret = scrub_repair_page_from_good_copy(
904 sblock_bad, sblock_other, page_num, 0);
905 if (0 == ret) {
906 page_bad->io_error = 0;
907 break; /* succeeded for this page */
908 }
909 }
910 }
911
912 if (page_bad->io_error) {
913 /* did not find a mirror to copy the page from */
914 success = 0;
915 }
916 }
917
918 if (success) {
919 if (is_metadata || have_csum) {
920 /*
921 * need to verify the checksum now that all
922 * sectors on disk are repaired (the write
923 * request for data to be repaired is on its way).
924 * Just be lazy and use scrub_recheck_block()
925 * which re-reads the data before the checksum
926 * is verified, but most likely the data comes out
927 * of the page cache.
928 */
929 ret = scrub_recheck_block(fs_info, sblock_bad,
930 is_metadata, have_csum, csum,
931 generation, sdev->csum_size);
932 if (!ret && !sblock_bad->header_error &&
933 !sblock_bad->checksum_error &&
934 sblock_bad->no_io_error_seen)
935 goto corrected_error;
936 else
937 goto did_not_correct_error;
938 } else {
939corrected_error:
940 spin_lock(&sdev->stat_lock);
941 sdev->stat.corrected_errors++;
942 spin_unlock(&sdev->stat_lock);
943 printk_ratelimited_in_rcu(KERN_ERR
944 "btrfs: fixed up error at logical %llu on dev %s\n",
945 (unsigned long long)logical,
946 rcu_str_deref(sdev->dev->name));
947 }
948 } else {
949did_not_correct_error:
950 spin_lock(&sdev->stat_lock);
951 sdev->stat.uncorrectable_errors++;
952 spin_unlock(&sdev->stat_lock);
953 printk_ratelimited_in_rcu(KERN_ERR
954 "btrfs: unable to fixup (regular) error at logical %llu on dev %s\n",
955 (unsigned long long)logical,
956 rcu_str_deref(sdev->dev->name));
957 }
958
959out:
960 if (sblocks_for_recheck) {
961 for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
962 mirror_index++) {
963 struct scrub_block *sblock = sblocks_for_recheck +
964 mirror_index;
965 int page_index;
966
967 for (page_index = 0; page_index < SCRUB_PAGES_PER_BIO;
968 page_index++)
969 if (sblock->pagev[page_index].page)
970 __free_page(
971 sblock->pagev[page_index].page);
972 }
973 kfree(sblocks_for_recheck);
974 }
975
976 return 0;
977}
978
979static int scrub_setup_recheck_block(struct scrub_dev *sdev,
980 struct btrfs_mapping_tree *map_tree,
981 u64 length, u64 logical,
982 struct scrub_block *sblocks_for_recheck)
983{
984 int page_index;
985 int mirror_index;
986 int ret;
987
988 /*
989 * note: the three members sdev, ref_count and outstanding_pages
990 * are not used (and not set) in the blocks that are used for
991 * the recheck procedure
992 */
993
994 page_index = 0;
995 while (length > 0) {
996 u64 sublen = min_t(u64, length, PAGE_SIZE);
997 u64 mapped_length = sublen;
998 struct btrfs_bio *bbio = NULL;
999
1000 /*
1001 * with a length of PAGE_SIZE, each returned stripe
1002 * represents one mirror
1003 */
1004 ret = btrfs_map_block(map_tree, WRITE, logical, &mapped_length,
1005 &bbio, 0);
1006 if (ret || !bbio || mapped_length < sublen) {
1007 kfree(bbio);
1008 return -EIO;
1009 }
1010
1011 BUG_ON(page_index >= SCRUB_PAGES_PER_BIO);
1012 for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
1013 mirror_index++) {
1014 struct scrub_block *sblock;
1015 struct scrub_page *page;
1016
1017 if (mirror_index >= BTRFS_MAX_MIRRORS)
1018 continue;
1019
1020 sblock = sblocks_for_recheck + mirror_index;
1021 page = sblock->pagev + page_index;
1022 page->logical = logical;
1023 page->physical = bbio->stripes[mirror_index].physical;
1024 /* for missing devices, dev->bdev is NULL */
1025 page->dev = bbio->stripes[mirror_index].dev;
1026 page->mirror_num = mirror_index + 1;
1027 page->page = alloc_page(GFP_NOFS);
1028 if (!page->page) {
1029 spin_lock(&sdev->stat_lock);
1030 sdev->stat.malloc_errors++;
1031 spin_unlock(&sdev->stat_lock);
1032 return -ENOMEM;
1033 }
1034 sblock->page_count++;
1035 }
1036 kfree(bbio);
1037 length -= sublen;
1038 logical += sublen;
1039 page_index++;
1040 }
1041
1042 return 0;
1043}
1044
1045/*
1046 * this function will check the on disk data for checksum errors, header
1047 * errors and read I/O errors. If any I/O errors happen, the exact pages
1048 * which are errored are marked as being bad. The goal is to enable scrub
1049 * to take those pages that are not errored from all the mirrors so that
1050 * the pages that are errored in the just handled mirror can be repaired.
1051 */
1052static int scrub_recheck_block(struct btrfs_fs_info *fs_info,
1053 struct scrub_block *sblock, int is_metadata,
1054 int have_csum, u8 *csum, u64 generation,
1055 u16 csum_size)
1056{
1057 int page_num;
1058
1059 sblock->no_io_error_seen = 1;
1060 sblock->header_error = 0;
1061 sblock->checksum_error = 0;
1062
1063 for (page_num = 0; page_num < sblock->page_count; page_num++) {
1064 struct bio *bio;
1065 int ret;
1066 struct scrub_page *page = sblock->pagev + page_num;
1067 DECLARE_COMPLETION_ONSTACK(complete);
1068
1069 if (page->dev->bdev == NULL) {
1070 page->io_error = 1;
1071 sblock->no_io_error_seen = 0;
1072 continue;
1073 }
1074
1075 BUG_ON(!page->page);
1076 bio = bio_alloc(GFP_NOFS, 1);
1077 if (!bio)
1078 return -EIO;
1079 bio->bi_bdev = page->dev->bdev;
1080 bio->bi_sector = page->physical >> 9;
1081 bio->bi_end_io = scrub_complete_bio_end_io;
1082 bio->bi_private = &complete;
1083
1084 ret = bio_add_page(bio, page->page, PAGE_SIZE, 0);
1085 if (PAGE_SIZE != ret) {
1086 bio_put(bio);
1087 return -EIO;
1088 }
1089 btrfsic_submit_bio(READ, bio);
1090
1091 /* this will also unplug the queue */
1092 wait_for_completion(&complete);
1093
1094 page->io_error = !test_bit(BIO_UPTODATE, &bio->bi_flags);
1095 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1096 sblock->no_io_error_seen = 0;
1097 bio_put(bio);
1098 }
1099
1100 if (sblock->no_io_error_seen)
1101 scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
1102 have_csum, csum, generation,
1103 csum_size);
1104
1105 return 0;
1106}
1107
1108static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
1109 struct scrub_block *sblock,
1110 int is_metadata, int have_csum,
1111 const u8 *csum, u64 generation,
1112 u16 csum_size)
1113{
1114 int page_num;
1115 u8 calculated_csum[BTRFS_CSUM_SIZE];
1116 u32 crc = ~(u32)0;
1117 struct btrfs_root *root = fs_info->extent_root;
1118 void *mapped_buffer;
1119
1120 BUG_ON(!sblock->pagev[0].page);
1121 if (is_metadata) {
1122 struct btrfs_header *h;
1123
1124 mapped_buffer = kmap_atomic(sblock->pagev[0].page);
1125 h = (struct btrfs_header *)mapped_buffer;
1126
1127 if (sblock->pagev[0].logical != le64_to_cpu(h->bytenr) ||
1128 memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
1129 memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1130 BTRFS_UUID_SIZE)) {
1131 sblock->header_error = 1;
1132 } else if (generation != le64_to_cpu(h->generation)) {
1133 sblock->header_error = 1;
1134 sblock->generation_error = 1;
1135 }
1136 csum = h->csum;
1137 } else {
1138 if (!have_csum)
1139 return;
1140
1141 mapped_buffer = kmap_atomic(sblock->pagev[0].page);
1142 }
1143
1144 for (page_num = 0;;) {
1145 if (page_num == 0 && is_metadata)
1146 crc = btrfs_csum_data(root,
1147 ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
1148 crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
1149 else
1150 crc = btrfs_csum_data(root, mapped_buffer, crc,
1151 PAGE_SIZE);
1152
1153 kunmap_atomic(mapped_buffer);
1154 page_num++;
1155 if (page_num >= sblock->page_count)
1156 break;
1157 BUG_ON(!sblock->pagev[page_num].page);
1158
1159 mapped_buffer = kmap_atomic(sblock->pagev[page_num].page);
1160 }
1161
1162 btrfs_csum_final(crc, calculated_csum);
1163 if (memcmp(calculated_csum, csum, csum_size))
1164 sblock->checksum_error = 1;
1165}
1166
1167static void scrub_complete_bio_end_io(struct bio *bio, int err)
1168{
1169 complete((struct completion *)bio->bi_private);
1170}
1171
1172static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
1173 struct scrub_block *sblock_good,
1174 int force_write)
1175{
1176 int page_num;
1177 int ret = 0;
1178
1179 for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
1180 int ret_sub;
1181
1182 ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
1183 sblock_good,
1184 page_num,
1185 force_write);
1186 if (ret_sub)
1187 ret = ret_sub;
1188 }
1189
1190 return ret;
1191}
1192
1193static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
1194 struct scrub_block *sblock_good,
1195 int page_num, int force_write)
1196{
1197 struct scrub_page *page_bad = sblock_bad->pagev + page_num;
1198 struct scrub_page *page_good = sblock_good->pagev + page_num;
1199
1200 BUG_ON(sblock_bad->pagev[page_num].page == NULL);
1201 BUG_ON(sblock_good->pagev[page_num].page == NULL);
1202 if (force_write || sblock_bad->header_error ||
1203 sblock_bad->checksum_error || page_bad->io_error) {
1204 struct bio *bio;
1205 int ret;
1206 DECLARE_COMPLETION_ONSTACK(complete);
1207
1208 bio = bio_alloc(GFP_NOFS, 1);
1209 if (!bio)
1210 return -EIO;
1211 bio->bi_bdev = page_bad->dev->bdev;
1212 bio->bi_sector = page_bad->physical >> 9;
1213 bio->bi_end_io = scrub_complete_bio_end_io;
1214 bio->bi_private = &complete;
1215
1216 ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
1217 if (PAGE_SIZE != ret) {
1218 bio_put(bio);
1219 return -EIO;
1220 }
1221 btrfsic_submit_bio(WRITE, bio);
1222
1223 /* this will also unplug the queue */
1224 wait_for_completion(&complete);
1225 if (!bio_flagged(bio, BIO_UPTODATE)) {
1226 btrfs_dev_stat_inc_and_print(page_bad->dev,
1227 BTRFS_DEV_STAT_WRITE_ERRS);
1228 bio_put(bio);
1229 return -EIO;
1230 }
1231 bio_put(bio);
1232 }
1233
1234 return 0;
1235}
1236
1237static void scrub_checksum(struct scrub_block *sblock)
1238{
1239 u64 flags;
1240 int ret;
1241
1242 BUG_ON(sblock->page_count < 1);
1243 flags = sblock->pagev[0].flags;
1244 ret = 0;
1245 if (flags & BTRFS_EXTENT_FLAG_DATA)
1246 ret = scrub_checksum_data(sblock);
1247 else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1248 ret = scrub_checksum_tree_block(sblock);
1249 else if (flags & BTRFS_EXTENT_FLAG_SUPER)
1250 (void)scrub_checksum_super(sblock);
1251 else
1252 WARN_ON(1);
1253 if (ret)
1254 scrub_handle_errored_block(sblock);
1255}
1256
1257static int scrub_checksum_data(struct scrub_block *sblock)
1258{
1259 struct scrub_dev *sdev = sblock->sdev;
1260 u8 csum[BTRFS_CSUM_SIZE];
1261 u8 *on_disk_csum;
1262 struct page *page;
1263 void *buffer;
1264 u32 crc = ~(u32)0;
1265 int fail = 0;
1266 struct btrfs_root *root = sdev->dev->dev_root;
1267 u64 len;
1268 int index;
1269
1270 BUG_ON(sblock->page_count < 1);
1271 if (!sblock->pagev[0].have_csum)
1272 return 0;
1273
1274 on_disk_csum = sblock->pagev[0].csum;
1275 page = sblock->pagev[0].page;
1276 buffer = kmap_atomic(page);
1277
1278 len = sdev->sectorsize;
1279 index = 0;
1280 for (;;) {
1281 u64 l = min_t(u64, len, PAGE_SIZE);
1282
1283 crc = btrfs_csum_data(root, buffer, crc, l);
1284 kunmap_atomic(buffer);
1285 len -= l;
1286 if (len == 0)
1287 break;
1288 index++;
1289 BUG_ON(index >= sblock->page_count);
1290 BUG_ON(!sblock->pagev[index].page);
1291 page = sblock->pagev[index].page;
1292 buffer = kmap_atomic(page);
1293 }
1294
1295 btrfs_csum_final(crc, csum);
1296 if (memcmp(csum, on_disk_csum, sdev->csum_size))
1297 fail = 1;
1298
1299 return fail;
1300}
1301
1302static int scrub_checksum_tree_block(struct scrub_block *sblock)
1303{
1304 struct scrub_dev *sdev = sblock->sdev;
1305 struct btrfs_header *h;
1306 struct btrfs_root *root = sdev->dev->dev_root;
1307 struct btrfs_fs_info *fs_info = root->fs_info;
1308 u8 calculated_csum[BTRFS_CSUM_SIZE];
1309 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1310 struct page *page;
1311 void *mapped_buffer;
1312 u64 mapped_size;
1313 void *p;
1314 u32 crc = ~(u32)0;
1315 int fail = 0;
1316 int crc_fail = 0;
1317 u64 len;
1318 int index;
1319
1320 BUG_ON(sblock->page_count < 1);
1321 page = sblock->pagev[0].page;
1322 mapped_buffer = kmap_atomic(page);
1323 h = (struct btrfs_header *)mapped_buffer;
1324 memcpy(on_disk_csum, h->csum, sdev->csum_size);
1325
1326 /*
1327 * we don't use the getter functions here, as we
1328 * a) don't have an extent buffer and
1329 * b) the page is already kmapped
1330 */
1331
1332 if (sblock->pagev[0].logical != le64_to_cpu(h->bytenr))
1333 ++fail;
1334
1335 if (sblock->pagev[0].generation != le64_to_cpu(h->generation))
1336 ++fail;
1337
1338 if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1339 ++fail;
1340
1341 if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
1342 BTRFS_UUID_SIZE))
1343 ++fail;
1344
1345 BUG_ON(sdev->nodesize != sdev->leafsize);
1346 len = sdev->nodesize - BTRFS_CSUM_SIZE;
1347 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1348 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1349 index = 0;
1350 for (;;) {
1351 u64 l = min_t(u64, len, mapped_size);
1352
1353 crc = btrfs_csum_data(root, p, crc, l);
1354 kunmap_atomic(mapped_buffer);
1355 len -= l;
1356 if (len == 0)
1357 break;
1358 index++;
1359 BUG_ON(index >= sblock->page_count);
1360 BUG_ON(!sblock->pagev[index].page);
1361 page = sblock->pagev[index].page;
1362 mapped_buffer = kmap_atomic(page);
1363 mapped_size = PAGE_SIZE;
1364 p = mapped_buffer;
1365 }
1366
1367 btrfs_csum_final(crc, calculated_csum);
1368 if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size))
1369 ++crc_fail;
1370
1371 return fail || crc_fail;
1372}
1373
1374static int scrub_checksum_super(struct scrub_block *sblock)
1375{
1376 struct btrfs_super_block *s;
1377 struct scrub_dev *sdev = sblock->sdev;
1378 struct btrfs_root *root = sdev->dev->dev_root;
1379 struct btrfs_fs_info *fs_info = root->fs_info;
1380 u8 calculated_csum[BTRFS_CSUM_SIZE];
1381 u8 on_disk_csum[BTRFS_CSUM_SIZE];
1382 struct page *page;
1383 void *mapped_buffer;
1384 u64 mapped_size;
1385 void *p;
1386 u32 crc = ~(u32)0;
1387 int fail_gen = 0;
1388 int fail_cor = 0;
1389 u64 len;
1390 int index;
1391
1392 BUG_ON(sblock->page_count < 1);
1393 page = sblock->pagev[0].page;
1394 mapped_buffer = kmap_atomic(page);
1395 s = (struct btrfs_super_block *)mapped_buffer;
1396 memcpy(on_disk_csum, s->csum, sdev->csum_size);
1397
1398 if (sblock->pagev[0].logical != le64_to_cpu(s->bytenr))
1399 ++fail_cor;
1400
1401 if (sblock->pagev[0].generation != le64_to_cpu(s->generation))
1402 ++fail_gen;
1403
1404 if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
1405 ++fail_cor;
1406
1407 len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
1408 mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
1409 p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
1410 index = 0;
1411 for (;;) {
1412 u64 l = min_t(u64, len, mapped_size);
1413
1414 crc = btrfs_csum_data(root, p, crc, l);
1415 kunmap_atomic(mapped_buffer);
1416 len -= l;
1417 if (len == 0)
1418 break;
1419 index++;
1420 BUG_ON(index >= sblock->page_count);
1421 BUG_ON(!sblock->pagev[index].page);
1422 page = sblock->pagev[index].page;
1423 mapped_buffer = kmap_atomic(page);
1424 mapped_size = PAGE_SIZE;
1425 p = mapped_buffer;
1426 }
1427
1428 btrfs_csum_final(crc, calculated_csum);
1429 if (memcmp(calculated_csum, on_disk_csum, sdev->csum_size))
1430 ++fail_cor;
1431
1432 if (fail_cor + fail_gen) {
1433 /*
1434 * if we find an error in a super block, we just report it.
1435 * They will get written with the next transaction commit
1436 * anyway
1437 */
1438 spin_lock(&sdev->stat_lock);
1439 ++sdev->stat.super_errors;
1440 spin_unlock(&sdev->stat_lock);
1441 if (fail_cor)
1442 btrfs_dev_stat_inc_and_print(sdev->dev,
1443 BTRFS_DEV_STAT_CORRUPTION_ERRS);
1444 else
1445 btrfs_dev_stat_inc_and_print(sdev->dev,
1446 BTRFS_DEV_STAT_GENERATION_ERRS);
1447 }
1448
1449 return fail_cor + fail_gen;
1450}
1451
1452static void scrub_block_get(struct scrub_block *sblock)
1453{
1454 atomic_inc(&sblock->ref_count);
1455}
1456
1457static void scrub_block_put(struct scrub_block *sblock)
1458{
1459 if (atomic_dec_and_test(&sblock->ref_count)) {
1460 int i;
1461
1462 for (i = 0; i < sblock->page_count; i++)
1463 if (sblock->pagev[i].page)
1464 __free_page(sblock->pagev[i].page);
1465 kfree(sblock);
1466 }
1467}
1468
1469static void scrub_submit(struct scrub_dev *sdev)
1470{
1471 struct scrub_bio *sbio;
1472
1473 if (sdev->curr == -1)
1474 return;
1475
1476 sbio = sdev->bios[sdev->curr];
1477 sdev->curr = -1;
1478 atomic_inc(&sdev->in_flight);
1479
1480 btrfsic_submit_bio(READ, sbio->bio);
1481}
1482
1483static int scrub_add_page_to_bio(struct scrub_dev *sdev,
1484 struct scrub_page *spage)
1485{
1486 struct scrub_block *sblock = spage->sblock;
1487 struct scrub_bio *sbio;
1488 int ret;
1489
1490again:
1491 /*
1492 * grab a fresh bio or wait for one to become available
1493 */
1494 while (sdev->curr == -1) {
1495 spin_lock(&sdev->list_lock);
1496 sdev->curr = sdev->first_free;
1497 if (sdev->curr != -1) {
1498 sdev->first_free = sdev->bios[sdev->curr]->next_free;
1499 sdev->bios[sdev->curr]->next_free = -1;
1500 sdev->bios[sdev->curr]->page_count = 0;
1501 spin_unlock(&sdev->list_lock);
1502 } else {
1503 spin_unlock(&sdev->list_lock);
1504 wait_event(sdev->list_wait, sdev->first_free != -1);
1505 }
1506 }
1507 sbio = sdev->bios[sdev->curr];
1508 if (sbio->page_count == 0) {
1509 struct bio *bio;
1510
1511 sbio->physical = spage->physical;
1512 sbio->logical = spage->logical;
1513 bio = sbio->bio;
1514 if (!bio) {
1515 bio = bio_alloc(GFP_NOFS, sdev->pages_per_bio);
1516 if (!bio)
1517 return -ENOMEM;
1518 sbio->bio = bio;
1519 }
1520
1521 bio->bi_private = sbio;
1522 bio->bi_end_io = scrub_bio_end_io;
1523 bio->bi_bdev = sdev->dev->bdev;
1524 bio->bi_sector = spage->physical >> 9;
1525 sbio->err = 0;
1526 } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
1527 spage->physical ||
1528 sbio->logical + sbio->page_count * PAGE_SIZE !=
1529 spage->logical) {
1530 scrub_submit(sdev);
1531 goto again;
1532 }
1533
1534 sbio->pagev[sbio->page_count] = spage;
1535 ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
1536 if (ret != PAGE_SIZE) {
1537 if (sbio->page_count < 1) {
1538 bio_put(sbio->bio);
1539 sbio->bio = NULL;
1540 return -EIO;
1541 }
1542 scrub_submit(sdev);
1543 goto again;
1544 }
1545
1546 scrub_block_get(sblock); /* one for the added page */
1547 atomic_inc(&sblock->outstanding_pages);
1548 sbio->page_count++;
1549 if (sbio->page_count == sdev->pages_per_bio)
1550 scrub_submit(sdev);
1551
1552 return 0;
1553}
1554
1555static int scrub_pages(struct scrub_dev *sdev, u64 logical, u64 len,
1556 u64 physical, u64 flags, u64 gen, int mirror_num,
1557 u8 *csum, int force)
1558{
1559 struct scrub_block *sblock;
1560 int index;
1561
1562 sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
1563 if (!sblock) {
1564 spin_lock(&sdev->stat_lock);
1565 sdev->stat.malloc_errors++;
1566 spin_unlock(&sdev->stat_lock);
1567 return -ENOMEM;
1568 }
1569
1570 /* one ref inside this function, plus one for each page later on */
1571 atomic_set(&sblock->ref_count, 1);
1572 sblock->sdev = sdev;
1573 sblock->no_io_error_seen = 1;
1574
1575 for (index = 0; len > 0; index++) {
1576 struct scrub_page *spage = sblock->pagev + index;
1577 u64 l = min_t(u64, len, PAGE_SIZE);
1578
1579 BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
1580 spage->page = alloc_page(GFP_NOFS);
1581 if (!spage->page) {
1582 spin_lock(&sdev->stat_lock);
1583 sdev->stat.malloc_errors++;
1584 spin_unlock(&sdev->stat_lock);
1585 while (index > 0) {
1586 index--;
1587 __free_page(sblock->pagev[index].page);
1588 }
1589 kfree(sblock);
1590 return -ENOMEM;
1591 }
1592 spage->sblock = sblock;
1593 spage->dev = sdev->dev;
1594 spage->flags = flags;
1595 spage->generation = gen;
1596 spage->logical = logical;
1597 spage->physical = physical;
1598 spage->mirror_num = mirror_num;
1599 if (csum) {
1600 spage->have_csum = 1;
1601 memcpy(spage->csum, csum, sdev->csum_size);
1602 } else {
1603 spage->have_csum = 0;
1604 }
1605 sblock->page_count++;
1606 len -= l;
1607 logical += l;
1608 physical += l;
1609 }
1610
1611 BUG_ON(sblock->page_count == 0);
1612 for (index = 0; index < sblock->page_count; index++) {
1613 struct scrub_page *spage = sblock->pagev + index;
1614 int ret;
1615
1616 ret = scrub_add_page_to_bio(sdev, spage);
1617 if (ret) {
1618 scrub_block_put(sblock);
1619 return ret;
1620 }
1621 }
1622
1623 if (force)
1624 scrub_submit(sdev);
1625
1626 /* last one frees, either here or in bio completion for last page */
1627 scrub_block_put(sblock);
1628 return 0;
1629}
1630
1631static void scrub_bio_end_io(struct bio *bio, int err)
1632{
1633 struct scrub_bio *sbio = bio->bi_private;
1634 struct scrub_dev *sdev = sbio->sdev;
1635 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1636
1637 sbio->err = err;
1638 sbio->bio = bio;
1639
1640 btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
1641}
1642
1643static void scrub_bio_end_io_worker(struct btrfs_work *work)
1644{
1645 struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
1646 struct scrub_dev *sdev = sbio->sdev;
1647 int i;
1648
1649 BUG_ON(sbio->page_count > SCRUB_PAGES_PER_BIO);
1650 if (sbio->err) {
1651 for (i = 0; i < sbio->page_count; i++) {
1652 struct scrub_page *spage = sbio->pagev[i];
1653
1654 spage->io_error = 1;
1655 spage->sblock->no_io_error_seen = 0;
1656 }
1657 }
1658
1659 /* now complete the scrub_block items that have all pages completed */
1660 for (i = 0; i < sbio->page_count; i++) {
1661 struct scrub_page *spage = sbio->pagev[i];
1662 struct scrub_block *sblock = spage->sblock;
1663
1664 if (atomic_dec_and_test(&sblock->outstanding_pages))
1665 scrub_block_complete(sblock);
1666 scrub_block_put(sblock);
1667 }
1668
1669 if (sbio->err) {
1670 /* what is this good for??? */
1671 sbio->bio->bi_flags &= ~(BIO_POOL_MASK - 1);
1672 sbio->bio->bi_flags |= 1 << BIO_UPTODATE;
1673 sbio->bio->bi_phys_segments = 0;
1674 sbio->bio->bi_idx = 0;
1675
1676 for (i = 0; i < sbio->page_count; i++) {
1677 struct bio_vec *bi;
1678 bi = &sbio->bio->bi_io_vec[i];
1679 bi->bv_offset = 0;
1680 bi->bv_len = PAGE_SIZE;
1681 }
1682 }
1683
1684 bio_put(sbio->bio);
1685 sbio->bio = NULL;
1686 spin_lock(&sdev->list_lock);
1687 sbio->next_free = sdev->first_free;
1688 sdev->first_free = sbio->index;
1689 spin_unlock(&sdev->list_lock);
1690 atomic_dec(&sdev->in_flight);
1691 wake_up(&sdev->list_wait);
1692}
1693
1694static void scrub_block_complete(struct scrub_block *sblock)
1695{
1696 if (!sblock->no_io_error_seen)
1697 scrub_handle_errored_block(sblock);
1698 else
1699 scrub_checksum(sblock);
1700}
1701
1702static int scrub_find_csum(struct scrub_dev *sdev, u64 logical, u64 len,
1703 u8 *csum)
1704{
1705 struct btrfs_ordered_sum *sum = NULL;
1706 int ret = 0;
1707 unsigned long i;
1708 unsigned long num_sectors;
1709
1710 while (!list_empty(&sdev->csum_list)) {
1711 sum = list_first_entry(&sdev->csum_list,
1712 struct btrfs_ordered_sum, list);
1713 if (sum->bytenr > logical)
1714 return 0;
1715 if (sum->bytenr + sum->len > logical)
1716 break;
1717
1718 ++sdev->stat.csum_discards;
1719 list_del(&sum->list);
1720 kfree(sum);
1721 sum = NULL;
1722 }
1723 if (!sum)
1724 return 0;
1725
1726 num_sectors = sum->len / sdev->sectorsize;
1727 for (i = 0; i < num_sectors; ++i) {
1728 if (sum->sums[i].bytenr == logical) {
1729 memcpy(csum, &sum->sums[i].sum, sdev->csum_size);
1730 ret = 1;
1731 break;
1732 }
1733 }
1734 if (ret && i == num_sectors - 1) {
1735 list_del(&sum->list);
1736 kfree(sum);
1737 }
1738 return ret;
1739}
1740
1741/* scrub extent tries to collect up to 64 kB for each bio */
1742static int scrub_extent(struct scrub_dev *sdev, u64 logical, u64 len,
1743 u64 physical, u64 flags, u64 gen, int mirror_num)
1744{
1745 int ret;
1746 u8 csum[BTRFS_CSUM_SIZE];
1747 u32 blocksize;
1748
1749 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1750 blocksize = sdev->sectorsize;
1751 spin_lock(&sdev->stat_lock);
1752 sdev->stat.data_extents_scrubbed++;
1753 sdev->stat.data_bytes_scrubbed += len;
1754 spin_unlock(&sdev->stat_lock);
1755 } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1756 BUG_ON(sdev->nodesize != sdev->leafsize);
1757 blocksize = sdev->nodesize;
1758 spin_lock(&sdev->stat_lock);
1759 sdev->stat.tree_extents_scrubbed++;
1760 sdev->stat.tree_bytes_scrubbed += len;
1761 spin_unlock(&sdev->stat_lock);
1762 } else {
1763 blocksize = sdev->sectorsize;
1764 BUG_ON(1);
1765 }
1766
1767 while (len) {
1768 u64 l = min_t(u64, len, blocksize);
1769 int have_csum = 0;
1770
1771 if (flags & BTRFS_EXTENT_FLAG_DATA) {
1772 /* push csums to sbio */
1773 have_csum = scrub_find_csum(sdev, logical, l, csum);
1774 if (have_csum == 0)
1775 ++sdev->stat.no_csum;
1776 }
1777 ret = scrub_pages(sdev, logical, l, physical, flags, gen,
1778 mirror_num, have_csum ? csum : NULL, 0);
1779 if (ret)
1780 return ret;
1781 len -= l;
1782 logical += l;
1783 physical += l;
1784 }
1785 return 0;
1786}
1787
1788static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
1789 struct map_lookup *map, int num, u64 base, u64 length)
1790{
1791 struct btrfs_path *path;
1792 struct btrfs_fs_info *fs_info = sdev->dev->dev_root->fs_info;
1793 struct btrfs_root *root = fs_info->extent_root;
1794 struct btrfs_root *csum_root = fs_info->csum_root;
1795 struct btrfs_extent_item *extent;
1796 struct blk_plug plug;
1797 u64 flags;
1798 int ret;
1799 int slot;
1800 int i;
1801 u64 nstripes;
1802 struct extent_buffer *l;
1803 struct btrfs_key key;
1804 u64 physical;
1805 u64 logical;
1806 u64 generation;
1807 int mirror_num;
1808 struct reada_control *reada1;
1809 struct reada_control *reada2;
1810 struct btrfs_key key_start;
1811 struct btrfs_key key_end;
1812
1813 u64 increment = map->stripe_len;
1814 u64 offset;
1815
1816 nstripes = length;
1817 offset = 0;
1818 do_div(nstripes, map->stripe_len);
1819 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1820 offset = map->stripe_len * num;
1821 increment = map->stripe_len * map->num_stripes;
1822 mirror_num = 1;
1823 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1824 int factor = map->num_stripes / map->sub_stripes;
1825 offset = map->stripe_len * (num / map->sub_stripes);
1826 increment = map->stripe_len * factor;
1827 mirror_num = num % map->sub_stripes + 1;
1828 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1829 increment = map->stripe_len;
1830 mirror_num = num % map->num_stripes + 1;
1831 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1832 increment = map->stripe_len;
1833 mirror_num = num % map->num_stripes + 1;
1834 } else {
1835 increment = map->stripe_len;
1836 mirror_num = 1;
1837 }
1838
1839 path = btrfs_alloc_path();
1840 if (!path)
1841 return -ENOMEM;
1842
1843 /*
1844 * work on commit root. The related disk blocks are static as
1845 * long as COW is applied. This means, it is save to rewrite
1846 * them to repair disk errors without any race conditions
1847 */
1848 path->search_commit_root = 1;
1849 path->skip_locking = 1;
1850
1851 /*
1852 * trigger the readahead for extent tree csum tree and wait for
1853 * completion. During readahead, the scrub is officially paused
1854 * to not hold off transaction commits
1855 */
1856 logical = base + offset;
1857
1858 wait_event(sdev->list_wait,
1859 atomic_read(&sdev->in_flight) == 0);
1860 atomic_inc(&fs_info->scrubs_paused);
1861 wake_up(&fs_info->scrub_pause_wait);
1862
1863 /* FIXME it might be better to start readahead at commit root */
1864 key_start.objectid = logical;
1865 key_start.type = BTRFS_EXTENT_ITEM_KEY;
1866 key_start.offset = (u64)0;
1867 key_end.objectid = base + offset + nstripes * increment;
1868 key_end.type = BTRFS_EXTENT_ITEM_KEY;
1869 key_end.offset = (u64)0;
1870 reada1 = btrfs_reada_add(root, &key_start, &key_end);
1871
1872 key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1873 key_start.type = BTRFS_EXTENT_CSUM_KEY;
1874 key_start.offset = logical;
1875 key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1876 key_end.type = BTRFS_EXTENT_CSUM_KEY;
1877 key_end.offset = base + offset + nstripes * increment;
1878 reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
1879
1880 if (!IS_ERR(reada1))
1881 btrfs_reada_wait(reada1);
1882 if (!IS_ERR(reada2))
1883 btrfs_reada_wait(reada2);
1884
1885 mutex_lock(&fs_info->scrub_lock);
1886 while (atomic_read(&fs_info->scrub_pause_req)) {
1887 mutex_unlock(&fs_info->scrub_lock);
1888 wait_event(fs_info->scrub_pause_wait,
1889 atomic_read(&fs_info->scrub_pause_req) == 0);
1890 mutex_lock(&fs_info->scrub_lock);
1891 }
1892 atomic_dec(&fs_info->scrubs_paused);
1893 mutex_unlock(&fs_info->scrub_lock);
1894 wake_up(&fs_info->scrub_pause_wait);
1895
1896 /*
1897 * collect all data csums for the stripe to avoid seeking during
1898 * the scrub. This might currently (crc32) end up to be about 1MB
1899 */
1900 blk_start_plug(&plug);
1901
1902 /*
1903 * now find all extents for each stripe and scrub them
1904 */
1905 logical = base + offset;
1906 physical = map->stripes[num].physical;
1907 ret = 0;
1908 for (i = 0; i < nstripes; ++i) {
1909 /*
1910 * canceled?
1911 */
1912 if (atomic_read(&fs_info->scrub_cancel_req) ||
1913 atomic_read(&sdev->cancel_req)) {
1914 ret = -ECANCELED;
1915 goto out;
1916 }
1917 /*
1918 * check to see if we have to pause
1919 */
1920 if (atomic_read(&fs_info->scrub_pause_req)) {
1921 /* push queued extents */
1922 scrub_submit(sdev);
1923 wait_event(sdev->list_wait,
1924 atomic_read(&sdev->in_flight) == 0);
1925 atomic_inc(&fs_info->scrubs_paused);
1926 wake_up(&fs_info->scrub_pause_wait);
1927 mutex_lock(&fs_info->scrub_lock);
1928 while (atomic_read(&fs_info->scrub_pause_req)) {
1929 mutex_unlock(&fs_info->scrub_lock);
1930 wait_event(fs_info->scrub_pause_wait,
1931 atomic_read(&fs_info->scrub_pause_req) == 0);
1932 mutex_lock(&fs_info->scrub_lock);
1933 }
1934 atomic_dec(&fs_info->scrubs_paused);
1935 mutex_unlock(&fs_info->scrub_lock);
1936 wake_up(&fs_info->scrub_pause_wait);
1937 }
1938
1939 ret = btrfs_lookup_csums_range(csum_root, logical,
1940 logical + map->stripe_len - 1,
1941 &sdev->csum_list, 1);
1942 if (ret)
1943 goto out;
1944
1945 key.objectid = logical;
1946 key.type = BTRFS_EXTENT_ITEM_KEY;
1947 key.offset = (u64)0;
1948
1949 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1950 if (ret < 0)
1951 goto out;
1952 if (ret > 0) {
1953 ret = btrfs_previous_item(root, path, 0,
1954 BTRFS_EXTENT_ITEM_KEY);
1955 if (ret < 0)
1956 goto out;
1957 if (ret > 0) {
1958 /* there's no smaller item, so stick with the
1959 * larger one */
1960 btrfs_release_path(path);
1961 ret = btrfs_search_slot(NULL, root, &key,
1962 path, 0, 0);
1963 if (ret < 0)
1964 goto out;
1965 }
1966 }
1967
1968 while (1) {
1969 l = path->nodes[0];
1970 slot = path->slots[0];
1971 if (slot >= btrfs_header_nritems(l)) {
1972 ret = btrfs_next_leaf(root, path);
1973 if (ret == 0)
1974 continue;
1975 if (ret < 0)
1976 goto out;
1977
1978 break;
1979 }
1980 btrfs_item_key_to_cpu(l, &key, slot);
1981
1982 if (key.objectid + key.offset <= logical)
1983 goto next;
1984
1985 if (key.objectid >= logical + map->stripe_len)
1986 break;
1987
1988 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY)
1989 goto next;
1990
1991 extent = btrfs_item_ptr(l, slot,
1992 struct btrfs_extent_item);
1993 flags = btrfs_extent_flags(l, extent);
1994 generation = btrfs_extent_generation(l, extent);
1995
1996 if (key.objectid < logical &&
1997 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1998 printk(KERN_ERR
1999 "btrfs scrub: tree block %llu spanning "
2000 "stripes, ignored. logical=%llu\n",
2001 (unsigned long long)key.objectid,
2002 (unsigned long long)logical);
2003 goto next;
2004 }
2005
2006 /*
2007 * trim extent to this stripe
2008 */
2009 if (key.objectid < logical) {
2010 key.offset -= logical - key.objectid;
2011 key.objectid = logical;
2012 }
2013 if (key.objectid + key.offset >
2014 logical + map->stripe_len) {
2015 key.offset = logical + map->stripe_len -
2016 key.objectid;
2017 }
2018
2019 ret = scrub_extent(sdev, key.objectid, key.offset,
2020 key.objectid - logical + physical,
2021 flags, generation, mirror_num);
2022 if (ret)
2023 goto out;
2024
2025next:
2026 path->slots[0]++;
2027 }
2028 btrfs_release_path(path);
2029 logical += increment;
2030 physical += map->stripe_len;
2031 spin_lock(&sdev->stat_lock);
2032 sdev->stat.last_physical = physical;
2033 spin_unlock(&sdev->stat_lock);
2034 }
2035 /* push queued extents */
2036 scrub_submit(sdev);
2037
2038out:
2039 blk_finish_plug(&plug);
2040 btrfs_free_path(path);
2041 return ret < 0 ? ret : 0;
2042}
2043
2044static noinline_for_stack int scrub_chunk(struct scrub_dev *sdev,
2045 u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 length,
2046 u64 dev_offset)
2047{
2048 struct btrfs_mapping_tree *map_tree =
2049 &sdev->dev->dev_root->fs_info->mapping_tree;
2050 struct map_lookup *map;
2051 struct extent_map *em;
2052 int i;
2053 int ret = -EINVAL;
2054
2055 read_lock(&map_tree->map_tree.lock);
2056 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2057 read_unlock(&map_tree->map_tree.lock);
2058
2059 if (!em)
2060 return -EINVAL;
2061
2062 map = (struct map_lookup *)em->bdev;
2063 if (em->start != chunk_offset)
2064 goto out;
2065
2066 if (em->len < length)
2067 goto out;
2068
2069 for (i = 0; i < map->num_stripes; ++i) {
2070 if (map->stripes[i].dev == sdev->dev &&
2071 map->stripes[i].physical == dev_offset) {
2072 ret = scrub_stripe(sdev, map, i, chunk_offset, length);
2073 if (ret)
2074 goto out;
2075 }
2076 }
2077out:
2078 free_extent_map(em);
2079
2080 return ret;
2081}
2082
2083static noinline_for_stack
2084int scrub_enumerate_chunks(struct scrub_dev *sdev, u64 start, u64 end)
2085{
2086 struct btrfs_dev_extent *dev_extent = NULL;
2087 struct btrfs_path *path;
2088 struct btrfs_root *root = sdev->dev->dev_root;
2089 struct btrfs_fs_info *fs_info = root->fs_info;
2090 u64 length;
2091 u64 chunk_tree;
2092 u64 chunk_objectid;
2093 u64 chunk_offset;
2094 int ret;
2095 int slot;
2096 struct extent_buffer *l;
2097 struct btrfs_key key;
2098 struct btrfs_key found_key;
2099 struct btrfs_block_group_cache *cache;
2100
2101 path = btrfs_alloc_path();
2102 if (!path)
2103 return -ENOMEM;
2104
2105 path->reada = 2;
2106 path->search_commit_root = 1;
2107 path->skip_locking = 1;
2108
2109 key.objectid = sdev->dev->devid;
2110 key.offset = 0ull;
2111 key.type = BTRFS_DEV_EXTENT_KEY;
2112
2113
2114 while (1) {
2115 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2116 if (ret < 0)
2117 break;
2118 if (ret > 0) {
2119 if (path->slots[0] >=
2120 btrfs_header_nritems(path->nodes[0])) {
2121 ret = btrfs_next_leaf(root, path);
2122 if (ret)
2123 break;
2124 }
2125 }
2126
2127 l = path->nodes[0];
2128 slot = path->slots[0];
2129
2130 btrfs_item_key_to_cpu(l, &found_key, slot);
2131
2132 if (found_key.objectid != sdev->dev->devid)
2133 break;
2134
2135 if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
2136 break;
2137
2138 if (found_key.offset >= end)
2139 break;
2140
2141 if (found_key.offset < key.offset)
2142 break;
2143
2144 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2145 length = btrfs_dev_extent_length(l, dev_extent);
2146
2147 if (found_key.offset + length <= start) {
2148 key.offset = found_key.offset + length;
2149 btrfs_release_path(path);
2150 continue;
2151 }
2152
2153 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2154 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2155 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2156
2157 /*
2158 * get a reference on the corresponding block group to prevent
2159 * the chunk from going away while we scrub it
2160 */
2161 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2162 if (!cache) {
2163 ret = -ENOENT;
2164 break;
2165 }
2166 ret = scrub_chunk(sdev, chunk_tree, chunk_objectid,
2167 chunk_offset, length, found_key.offset);
2168 btrfs_put_block_group(cache);
2169 if (ret)
2170 break;
2171
2172 key.offset = found_key.offset + length;
2173 btrfs_release_path(path);
2174 }
2175
2176 btrfs_free_path(path);
2177
2178 /*
2179 * ret can still be 1 from search_slot or next_leaf,
2180 * that's not an error
2181 */
2182 return ret < 0 ? ret : 0;
2183}
2184
2185static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
2186{
2187 int i;
2188 u64 bytenr;
2189 u64 gen;
2190 int ret;
2191 struct btrfs_device *device = sdev->dev;
2192 struct btrfs_root *root = device->dev_root;
2193
2194 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2195 return -EIO;
2196
2197 gen = root->fs_info->last_trans_committed;
2198
2199 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2200 bytenr = btrfs_sb_offset(i);
2201 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
2202 break;
2203
2204 ret = scrub_pages(sdev, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
2205 BTRFS_EXTENT_FLAG_SUPER, gen, i, NULL, 1);
2206 if (ret)
2207 return ret;
2208 }
2209 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
2210
2211 return 0;
2212}
2213
2214/*
2215 * get a reference count on fs_info->scrub_workers. start worker if necessary
2216 */
2217static noinline_for_stack int scrub_workers_get(struct btrfs_root *root)
2218{
2219 struct btrfs_fs_info *fs_info = root->fs_info;
2220 int ret = 0;
2221
2222 mutex_lock(&fs_info->scrub_lock);
2223 if (fs_info->scrub_workers_refcnt == 0) {
2224 btrfs_init_workers(&fs_info->scrub_workers, "scrub",
2225 fs_info->thread_pool_size, &fs_info->generic_worker);
2226 fs_info->scrub_workers.idle_thresh = 4;
2227 ret = btrfs_start_workers(&fs_info->scrub_workers);
2228 if (ret)
2229 goto out;
2230 }
2231 ++fs_info->scrub_workers_refcnt;
2232out:
2233 mutex_unlock(&fs_info->scrub_lock);
2234
2235 return ret;
2236}
2237
2238static noinline_for_stack void scrub_workers_put(struct btrfs_root *root)
2239{
2240 struct btrfs_fs_info *fs_info = root->fs_info;
2241
2242 mutex_lock(&fs_info->scrub_lock);
2243 if (--fs_info->scrub_workers_refcnt == 0)
2244 btrfs_stop_workers(&fs_info->scrub_workers);
2245 WARN_ON(fs_info->scrub_workers_refcnt < 0);
2246 mutex_unlock(&fs_info->scrub_lock);
2247}
2248
2249
2250int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
2251 struct btrfs_scrub_progress *progress, int readonly)
2252{
2253 struct scrub_dev *sdev;
2254 struct btrfs_fs_info *fs_info = root->fs_info;
2255 int ret;
2256 struct btrfs_device *dev;
2257
2258 if (btrfs_fs_closing(root->fs_info))
2259 return -EINVAL;
2260
2261 /*
2262 * check some assumptions
2263 */
2264 if (root->nodesize != root->leafsize) {
2265 printk(KERN_ERR
2266 "btrfs_scrub: size assumption nodesize == leafsize (%d == %d) fails\n",
2267 root->nodesize, root->leafsize);
2268 return -EINVAL;
2269 }
2270
2271 if (root->nodesize > BTRFS_STRIPE_LEN) {
2272 /*
2273 * in this case scrub is unable to calculate the checksum
2274 * the way scrub is implemented. Do not handle this
2275 * situation at all because it won't ever happen.
2276 */
2277 printk(KERN_ERR
2278 "btrfs_scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails\n",
2279 root->nodesize, BTRFS_STRIPE_LEN);
2280 return -EINVAL;
2281 }
2282
2283 if (root->sectorsize != PAGE_SIZE) {
2284 /* not supported for data w/o checksums */
2285 printk(KERN_ERR
2286 "btrfs_scrub: size assumption sectorsize != PAGE_SIZE (%d != %lld) fails\n",
2287 root->sectorsize, (unsigned long long)PAGE_SIZE);
2288 return -EINVAL;
2289 }
2290
2291 ret = scrub_workers_get(root);
2292 if (ret)
2293 return ret;
2294
2295 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2296 dev = btrfs_find_device(root, devid, NULL, NULL);
2297 if (!dev || dev->missing) {
2298 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2299 scrub_workers_put(root);
2300 return -ENODEV;
2301 }
2302 mutex_lock(&fs_info->scrub_lock);
2303
2304 if (!dev->in_fs_metadata) {
2305 mutex_unlock(&fs_info->scrub_lock);
2306 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2307 scrub_workers_put(root);
2308 return -ENODEV;
2309 }
2310
2311 if (dev->scrub_device) {
2312 mutex_unlock(&fs_info->scrub_lock);
2313 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2314 scrub_workers_put(root);
2315 return -EINPROGRESS;
2316 }
2317 sdev = scrub_setup_dev(dev);
2318 if (IS_ERR(sdev)) {
2319 mutex_unlock(&fs_info->scrub_lock);
2320 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2321 scrub_workers_put(root);
2322 return PTR_ERR(sdev);
2323 }
2324 sdev->readonly = readonly;
2325 dev->scrub_device = sdev;
2326
2327 atomic_inc(&fs_info->scrubs_running);
2328 mutex_unlock(&fs_info->scrub_lock);
2329 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2330
2331 down_read(&fs_info->scrub_super_lock);
2332 ret = scrub_supers(sdev);
2333 up_read(&fs_info->scrub_super_lock);
2334
2335 if (!ret)
2336 ret = scrub_enumerate_chunks(sdev, start, end);
2337
2338 wait_event(sdev->list_wait, atomic_read(&sdev->in_flight) == 0);
2339 atomic_dec(&fs_info->scrubs_running);
2340 wake_up(&fs_info->scrub_pause_wait);
2341
2342 wait_event(sdev->list_wait, atomic_read(&sdev->fixup_cnt) == 0);
2343
2344 if (progress)
2345 memcpy(progress, &sdev->stat, sizeof(*progress));
2346
2347 mutex_lock(&fs_info->scrub_lock);
2348 dev->scrub_device = NULL;
2349 mutex_unlock(&fs_info->scrub_lock);
2350
2351 scrub_free_dev(sdev);
2352 scrub_workers_put(root);
2353
2354 return ret;
2355}
2356
2357void btrfs_scrub_pause(struct btrfs_root *root)
2358{
2359 struct btrfs_fs_info *fs_info = root->fs_info;
2360
2361 mutex_lock(&fs_info->scrub_lock);
2362 atomic_inc(&fs_info->scrub_pause_req);
2363 while (atomic_read(&fs_info->scrubs_paused) !=
2364 atomic_read(&fs_info->scrubs_running)) {
2365 mutex_unlock(&fs_info->scrub_lock);
2366 wait_event(fs_info->scrub_pause_wait,
2367 atomic_read(&fs_info->scrubs_paused) ==
2368 atomic_read(&fs_info->scrubs_running));
2369 mutex_lock(&fs_info->scrub_lock);
2370 }
2371 mutex_unlock(&fs_info->scrub_lock);
2372}
2373
2374void btrfs_scrub_continue(struct btrfs_root *root)
2375{
2376 struct btrfs_fs_info *fs_info = root->fs_info;
2377
2378 atomic_dec(&fs_info->scrub_pause_req);
2379 wake_up(&fs_info->scrub_pause_wait);
2380}
2381
2382void btrfs_scrub_pause_super(struct btrfs_root *root)
2383{
2384 down_write(&root->fs_info->scrub_super_lock);
2385}
2386
2387void btrfs_scrub_continue_super(struct btrfs_root *root)
2388{
2389 up_write(&root->fs_info->scrub_super_lock);
2390}
2391
2392int __btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
2393{
2394
2395 mutex_lock(&fs_info->scrub_lock);
2396 if (!atomic_read(&fs_info->scrubs_running)) {
2397 mutex_unlock(&fs_info->scrub_lock);
2398 return -ENOTCONN;
2399 }
2400
2401 atomic_inc(&fs_info->scrub_cancel_req);
2402 while (atomic_read(&fs_info->scrubs_running)) {
2403 mutex_unlock(&fs_info->scrub_lock);
2404 wait_event(fs_info->scrub_pause_wait,
2405 atomic_read(&fs_info->scrubs_running) == 0);
2406 mutex_lock(&fs_info->scrub_lock);
2407 }
2408 atomic_dec(&fs_info->scrub_cancel_req);
2409 mutex_unlock(&fs_info->scrub_lock);
2410
2411 return 0;
2412}
2413
2414int btrfs_scrub_cancel(struct btrfs_root *root)
2415{
2416 return __btrfs_scrub_cancel(root->fs_info);
2417}
2418
2419int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev)
2420{
2421 struct btrfs_fs_info *fs_info = root->fs_info;
2422 struct scrub_dev *sdev;
2423
2424 mutex_lock(&fs_info->scrub_lock);
2425 sdev = dev->scrub_device;
2426 if (!sdev) {
2427 mutex_unlock(&fs_info->scrub_lock);
2428 return -ENOTCONN;
2429 }
2430 atomic_inc(&sdev->cancel_req);
2431 while (dev->scrub_device) {
2432 mutex_unlock(&fs_info->scrub_lock);
2433 wait_event(fs_info->scrub_pause_wait,
2434 dev->scrub_device == NULL);
2435 mutex_lock(&fs_info->scrub_lock);
2436 }
2437 mutex_unlock(&fs_info->scrub_lock);
2438
2439 return 0;
2440}
2441
2442int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid)
2443{
2444 struct btrfs_fs_info *fs_info = root->fs_info;
2445 struct btrfs_device *dev;
2446 int ret;
2447
2448 /*
2449 * we have to hold the device_list_mutex here so the device
2450 * does not go away in cancel_dev. FIXME: find a better solution
2451 */
2452 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2453 dev = btrfs_find_device(root, devid, NULL, NULL);
2454 if (!dev) {
2455 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2456 return -ENODEV;
2457 }
2458 ret = btrfs_scrub_cancel_dev(root, dev);
2459 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2460
2461 return ret;
2462}
2463
2464int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
2465 struct btrfs_scrub_progress *progress)
2466{
2467 struct btrfs_device *dev;
2468 struct scrub_dev *sdev = NULL;
2469
2470 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2471 dev = btrfs_find_device(root, devid, NULL, NULL);
2472 if (dev)
2473 sdev = dev->scrub_device;
2474 if (sdev)
2475 memcpy(progress, &sdev->stat, sizeof(*progress));
2476 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2477
2478 return dev ? (sdev ? 0 : -ENOTCONN) : -ENODEV;
2479}