Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2012 Fusion-io All rights reserved.
4 * Copyright (C) 2012 Intel Corp. All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/bio.h>
9#include <linux/slab.h>
10#include <linux/blkdev.h>
11#include <linux/raid/pq.h>
12#include <linux/hash.h>
13#include <linux/list_sort.h>
14#include <linux/raid/xor.h>
15#include <linux/mm.h>
16#include "messages.h"
17#include "misc.h"
18#include "ctree.h"
19#include "disk-io.h"
20#include "volumes.h"
21#include "raid56.h"
22#include "async-thread.h"
23#include "file-item.h"
24#include "btrfs_inode.h"
25
26/* set when additional merges to this rbio are not allowed */
27#define RBIO_RMW_LOCKED_BIT 1
28
29/*
30 * set when this rbio is sitting in the hash, but it is just a cache
31 * of past RMW
32 */
33#define RBIO_CACHE_BIT 2
34
35/*
36 * set when it is safe to trust the stripe_pages for caching
37 */
38#define RBIO_CACHE_READY_BIT 3
39
40#define RBIO_CACHE_SIZE 1024
41
42#define BTRFS_STRIPE_HASH_TABLE_BITS 11
43
44/* Used by the raid56 code to lock stripes for read/modify/write */
45struct btrfs_stripe_hash {
46 struct list_head hash_list;
47 spinlock_t lock;
48};
49
50/* Used by the raid56 code to lock stripes for read/modify/write */
51struct btrfs_stripe_hash_table {
52 struct list_head stripe_cache;
53 spinlock_t cache_lock;
54 int cache_size;
55 struct btrfs_stripe_hash table[];
56};
57
58/*
59 * A bvec like structure to present a sector inside a page.
60 *
61 * Unlike bvec we don't need bvlen, as it's fixed to sectorsize.
62 */
63struct sector_ptr {
64 struct page *page;
65 unsigned int pgoff:24;
66 unsigned int uptodate:8;
67};
68
69static void rmw_rbio_work(struct work_struct *work);
70static void rmw_rbio_work_locked(struct work_struct *work);
71static void index_rbio_pages(struct btrfs_raid_bio *rbio);
72static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
73
74static int finish_parity_scrub(struct btrfs_raid_bio *rbio);
75static void scrub_rbio_work_locked(struct work_struct *work);
76
77static void free_raid_bio_pointers(struct btrfs_raid_bio *rbio)
78{
79 bitmap_free(rbio->error_bitmap);
80 kfree(rbio->stripe_pages);
81 kfree(rbio->bio_sectors);
82 kfree(rbio->stripe_sectors);
83 kfree(rbio->finish_pointers);
84}
85
86static void free_raid_bio(struct btrfs_raid_bio *rbio)
87{
88 int i;
89
90 if (!refcount_dec_and_test(&rbio->refs))
91 return;
92
93 WARN_ON(!list_empty(&rbio->stripe_cache));
94 WARN_ON(!list_empty(&rbio->hash_list));
95 WARN_ON(!bio_list_empty(&rbio->bio_list));
96
97 for (i = 0; i < rbio->nr_pages; i++) {
98 if (rbio->stripe_pages[i]) {
99 __free_page(rbio->stripe_pages[i]);
100 rbio->stripe_pages[i] = NULL;
101 }
102 }
103
104 btrfs_put_bioc(rbio->bioc);
105 free_raid_bio_pointers(rbio);
106 kfree(rbio);
107}
108
109static void start_async_work(struct btrfs_raid_bio *rbio, work_func_t work_func)
110{
111 INIT_WORK(&rbio->work, work_func);
112 queue_work(rbio->bioc->fs_info->rmw_workers, &rbio->work);
113}
114
115/*
116 * the stripe hash table is used for locking, and to collect
117 * bios in hopes of making a full stripe
118 */
119int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
120{
121 struct btrfs_stripe_hash_table *table;
122 struct btrfs_stripe_hash_table *x;
123 struct btrfs_stripe_hash *cur;
124 struct btrfs_stripe_hash *h;
125 int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
126 int i;
127
128 if (info->stripe_hash_table)
129 return 0;
130
131 /*
132 * The table is large, starting with order 4 and can go as high as
133 * order 7 in case lock debugging is turned on.
134 *
135 * Try harder to allocate and fallback to vmalloc to lower the chance
136 * of a failing mount.
137 */
138 table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL);
139 if (!table)
140 return -ENOMEM;
141
142 spin_lock_init(&table->cache_lock);
143 INIT_LIST_HEAD(&table->stripe_cache);
144
145 h = table->table;
146
147 for (i = 0; i < num_entries; i++) {
148 cur = h + i;
149 INIT_LIST_HEAD(&cur->hash_list);
150 spin_lock_init(&cur->lock);
151 }
152
153 x = cmpxchg(&info->stripe_hash_table, NULL, table);
154 kvfree(x);
155 return 0;
156}
157
158/*
159 * caching an rbio means to copy anything from the
160 * bio_sectors array into the stripe_pages array. We
161 * use the page uptodate bit in the stripe cache array
162 * to indicate if it has valid data
163 *
164 * once the caching is done, we set the cache ready
165 * bit.
166 */
167static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
168{
169 int i;
170 int ret;
171
172 ret = alloc_rbio_pages(rbio);
173 if (ret)
174 return;
175
176 for (i = 0; i < rbio->nr_sectors; i++) {
177 /* Some range not covered by bio (partial write), skip it */
178 if (!rbio->bio_sectors[i].page) {
179 /*
180 * Even if the sector is not covered by bio, if it is
181 * a data sector it should still be uptodate as it is
182 * read from disk.
183 */
184 if (i < rbio->nr_data * rbio->stripe_nsectors)
185 ASSERT(rbio->stripe_sectors[i].uptodate);
186 continue;
187 }
188
189 ASSERT(rbio->stripe_sectors[i].page);
190 memcpy_page(rbio->stripe_sectors[i].page,
191 rbio->stripe_sectors[i].pgoff,
192 rbio->bio_sectors[i].page,
193 rbio->bio_sectors[i].pgoff,
194 rbio->bioc->fs_info->sectorsize);
195 rbio->stripe_sectors[i].uptodate = 1;
196 }
197 set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
198}
199
200/*
201 * we hash on the first logical address of the stripe
202 */
203static int rbio_bucket(struct btrfs_raid_bio *rbio)
204{
205 u64 num = rbio->bioc->full_stripe_logical;
206
207 /*
208 * we shift down quite a bit. We're using byte
209 * addressing, and most of the lower bits are zeros.
210 * This tends to upset hash_64, and it consistently
211 * returns just one or two different values.
212 *
213 * shifting off the lower bits fixes things.
214 */
215 return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
216}
217
218static bool full_page_sectors_uptodate(struct btrfs_raid_bio *rbio,
219 unsigned int page_nr)
220{
221 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
222 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
223 int i;
224
225 ASSERT(page_nr < rbio->nr_pages);
226
227 for (i = sectors_per_page * page_nr;
228 i < sectors_per_page * page_nr + sectors_per_page;
229 i++) {
230 if (!rbio->stripe_sectors[i].uptodate)
231 return false;
232 }
233 return true;
234}
235
236/*
237 * Update the stripe_sectors[] array to use correct page and pgoff
238 *
239 * Should be called every time any page pointer in stripes_pages[] got modified.
240 */
241static void index_stripe_sectors(struct btrfs_raid_bio *rbio)
242{
243 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
244 u32 offset;
245 int i;
246
247 for (i = 0, offset = 0; i < rbio->nr_sectors; i++, offset += sectorsize) {
248 int page_index = offset >> PAGE_SHIFT;
249
250 ASSERT(page_index < rbio->nr_pages);
251 rbio->stripe_sectors[i].page = rbio->stripe_pages[page_index];
252 rbio->stripe_sectors[i].pgoff = offset_in_page(offset);
253 }
254}
255
256static void steal_rbio_page(struct btrfs_raid_bio *src,
257 struct btrfs_raid_bio *dest, int page_nr)
258{
259 const u32 sectorsize = src->bioc->fs_info->sectorsize;
260 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
261 int i;
262
263 if (dest->stripe_pages[page_nr])
264 __free_page(dest->stripe_pages[page_nr]);
265 dest->stripe_pages[page_nr] = src->stripe_pages[page_nr];
266 src->stripe_pages[page_nr] = NULL;
267
268 /* Also update the sector->uptodate bits. */
269 for (i = sectors_per_page * page_nr;
270 i < sectors_per_page * page_nr + sectors_per_page; i++)
271 dest->stripe_sectors[i].uptodate = true;
272}
273
274static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr)
275{
276 const int sector_nr = (page_nr << PAGE_SHIFT) >>
277 rbio->bioc->fs_info->sectorsize_bits;
278
279 /*
280 * We have ensured PAGE_SIZE is aligned with sectorsize, thus
281 * we won't have a page which is half data half parity.
282 *
283 * Thus if the first sector of the page belongs to data stripes, then
284 * the full page belongs to data stripes.
285 */
286 return (sector_nr < rbio->nr_data * rbio->stripe_nsectors);
287}
288
289/*
290 * Stealing an rbio means taking all the uptodate pages from the stripe array
291 * in the source rbio and putting them into the destination rbio.
292 *
293 * This will also update the involved stripe_sectors[] which are referring to
294 * the old pages.
295 */
296static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
297{
298 int i;
299
300 if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
301 return;
302
303 for (i = 0; i < dest->nr_pages; i++) {
304 struct page *p = src->stripe_pages[i];
305
306 /*
307 * We don't need to steal P/Q pages as they will always be
308 * regenerated for RMW or full write anyway.
309 */
310 if (!is_data_stripe_page(src, i))
311 continue;
312
313 /*
314 * If @src already has RBIO_CACHE_READY_BIT, it should have
315 * all data stripe pages present and uptodate.
316 */
317 ASSERT(p);
318 ASSERT(full_page_sectors_uptodate(src, i));
319 steal_rbio_page(src, dest, i);
320 }
321 index_stripe_sectors(dest);
322 index_stripe_sectors(src);
323}
324
325/*
326 * merging means we take the bio_list from the victim and
327 * splice it into the destination. The victim should
328 * be discarded afterwards.
329 *
330 * must be called with dest->rbio_list_lock held
331 */
332static void merge_rbio(struct btrfs_raid_bio *dest,
333 struct btrfs_raid_bio *victim)
334{
335 bio_list_merge(&dest->bio_list, &victim->bio_list);
336 dest->bio_list_bytes += victim->bio_list_bytes;
337 /* Also inherit the bitmaps from @victim. */
338 bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap,
339 dest->stripe_nsectors);
340 bio_list_init(&victim->bio_list);
341}
342
343/*
344 * used to prune items that are in the cache. The caller
345 * must hold the hash table lock.
346 */
347static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
348{
349 int bucket = rbio_bucket(rbio);
350 struct btrfs_stripe_hash_table *table;
351 struct btrfs_stripe_hash *h;
352 int freeit = 0;
353
354 /*
355 * check the bit again under the hash table lock.
356 */
357 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
358 return;
359
360 table = rbio->bioc->fs_info->stripe_hash_table;
361 h = table->table + bucket;
362
363 /* hold the lock for the bucket because we may be
364 * removing it from the hash table
365 */
366 spin_lock(&h->lock);
367
368 /*
369 * hold the lock for the bio list because we need
370 * to make sure the bio list is empty
371 */
372 spin_lock(&rbio->bio_list_lock);
373
374 if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
375 list_del_init(&rbio->stripe_cache);
376 table->cache_size -= 1;
377 freeit = 1;
378
379 /* if the bio list isn't empty, this rbio is
380 * still involved in an IO. We take it out
381 * of the cache list, and drop the ref that
382 * was held for the list.
383 *
384 * If the bio_list was empty, we also remove
385 * the rbio from the hash_table, and drop
386 * the corresponding ref
387 */
388 if (bio_list_empty(&rbio->bio_list)) {
389 if (!list_empty(&rbio->hash_list)) {
390 list_del_init(&rbio->hash_list);
391 refcount_dec(&rbio->refs);
392 BUG_ON(!list_empty(&rbio->plug_list));
393 }
394 }
395 }
396
397 spin_unlock(&rbio->bio_list_lock);
398 spin_unlock(&h->lock);
399
400 if (freeit)
401 free_raid_bio(rbio);
402}
403
404/*
405 * prune a given rbio from the cache
406 */
407static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
408{
409 struct btrfs_stripe_hash_table *table;
410
411 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
412 return;
413
414 table = rbio->bioc->fs_info->stripe_hash_table;
415
416 spin_lock(&table->cache_lock);
417 __remove_rbio_from_cache(rbio);
418 spin_unlock(&table->cache_lock);
419}
420
421/*
422 * remove everything in the cache
423 */
424static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
425{
426 struct btrfs_stripe_hash_table *table;
427 struct btrfs_raid_bio *rbio;
428
429 table = info->stripe_hash_table;
430
431 spin_lock(&table->cache_lock);
432 while (!list_empty(&table->stripe_cache)) {
433 rbio = list_entry(table->stripe_cache.next,
434 struct btrfs_raid_bio,
435 stripe_cache);
436 __remove_rbio_from_cache(rbio);
437 }
438 spin_unlock(&table->cache_lock);
439}
440
441/*
442 * remove all cached entries and free the hash table
443 * used by unmount
444 */
445void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
446{
447 if (!info->stripe_hash_table)
448 return;
449 btrfs_clear_rbio_cache(info);
450 kvfree(info->stripe_hash_table);
451 info->stripe_hash_table = NULL;
452}
453
454/*
455 * insert an rbio into the stripe cache. It
456 * must have already been prepared by calling
457 * cache_rbio_pages
458 *
459 * If this rbio was already cached, it gets
460 * moved to the front of the lru.
461 *
462 * If the size of the rbio cache is too big, we
463 * prune an item.
464 */
465static void cache_rbio(struct btrfs_raid_bio *rbio)
466{
467 struct btrfs_stripe_hash_table *table;
468
469 if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
470 return;
471
472 table = rbio->bioc->fs_info->stripe_hash_table;
473
474 spin_lock(&table->cache_lock);
475 spin_lock(&rbio->bio_list_lock);
476
477 /* bump our ref if we were not in the list before */
478 if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
479 refcount_inc(&rbio->refs);
480
481 if (!list_empty(&rbio->stripe_cache)){
482 list_move(&rbio->stripe_cache, &table->stripe_cache);
483 } else {
484 list_add(&rbio->stripe_cache, &table->stripe_cache);
485 table->cache_size += 1;
486 }
487
488 spin_unlock(&rbio->bio_list_lock);
489
490 if (table->cache_size > RBIO_CACHE_SIZE) {
491 struct btrfs_raid_bio *found;
492
493 found = list_entry(table->stripe_cache.prev,
494 struct btrfs_raid_bio,
495 stripe_cache);
496
497 if (found != rbio)
498 __remove_rbio_from_cache(found);
499 }
500
501 spin_unlock(&table->cache_lock);
502}
503
504/*
505 * helper function to run the xor_blocks api. It is only
506 * able to do MAX_XOR_BLOCKS at a time, so we need to
507 * loop through.
508 */
509static void run_xor(void **pages, int src_cnt, ssize_t len)
510{
511 int src_off = 0;
512 int xor_src_cnt = 0;
513 void *dest = pages[src_cnt];
514
515 while(src_cnt > 0) {
516 xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
517 xor_blocks(xor_src_cnt, len, dest, pages + src_off);
518
519 src_cnt -= xor_src_cnt;
520 src_off += xor_src_cnt;
521 }
522}
523
524/*
525 * Returns true if the bio list inside this rbio covers an entire stripe (no
526 * rmw required).
527 */
528static int rbio_is_full(struct btrfs_raid_bio *rbio)
529{
530 unsigned long size = rbio->bio_list_bytes;
531 int ret = 1;
532
533 spin_lock(&rbio->bio_list_lock);
534 if (size != rbio->nr_data * BTRFS_STRIPE_LEN)
535 ret = 0;
536 BUG_ON(size > rbio->nr_data * BTRFS_STRIPE_LEN);
537 spin_unlock(&rbio->bio_list_lock);
538
539 return ret;
540}
541
542/*
543 * returns 1 if it is safe to merge two rbios together.
544 * The merging is safe if the two rbios correspond to
545 * the same stripe and if they are both going in the same
546 * direction (read vs write), and if neither one is
547 * locked for final IO
548 *
549 * The caller is responsible for locking such that
550 * rmw_locked is safe to test
551 */
552static int rbio_can_merge(struct btrfs_raid_bio *last,
553 struct btrfs_raid_bio *cur)
554{
555 if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
556 test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
557 return 0;
558
559 /*
560 * we can't merge with cached rbios, since the
561 * idea is that when we merge the destination
562 * rbio is going to run our IO for us. We can
563 * steal from cached rbios though, other functions
564 * handle that.
565 */
566 if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
567 test_bit(RBIO_CACHE_BIT, &cur->flags))
568 return 0;
569
570 if (last->bioc->full_stripe_logical != cur->bioc->full_stripe_logical)
571 return 0;
572
573 /* we can't merge with different operations */
574 if (last->operation != cur->operation)
575 return 0;
576 /*
577 * We've need read the full stripe from the drive.
578 * check and repair the parity and write the new results.
579 *
580 * We're not allowed to add any new bios to the
581 * bio list here, anyone else that wants to
582 * change this stripe needs to do their own rmw.
583 */
584 if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
585 return 0;
586
587 if (last->operation == BTRFS_RBIO_READ_REBUILD)
588 return 0;
589
590 return 1;
591}
592
593static unsigned int rbio_stripe_sector_index(const struct btrfs_raid_bio *rbio,
594 unsigned int stripe_nr,
595 unsigned int sector_nr)
596{
597 ASSERT(stripe_nr < rbio->real_stripes);
598 ASSERT(sector_nr < rbio->stripe_nsectors);
599
600 return stripe_nr * rbio->stripe_nsectors + sector_nr;
601}
602
603/* Return a sector from rbio->stripe_sectors, not from the bio list */
604static struct sector_ptr *rbio_stripe_sector(const struct btrfs_raid_bio *rbio,
605 unsigned int stripe_nr,
606 unsigned int sector_nr)
607{
608 return &rbio->stripe_sectors[rbio_stripe_sector_index(rbio, stripe_nr,
609 sector_nr)];
610}
611
612/* Grab a sector inside P stripe */
613static struct sector_ptr *rbio_pstripe_sector(const struct btrfs_raid_bio *rbio,
614 unsigned int sector_nr)
615{
616 return rbio_stripe_sector(rbio, rbio->nr_data, sector_nr);
617}
618
619/* Grab a sector inside Q stripe, return NULL if not RAID6 */
620static struct sector_ptr *rbio_qstripe_sector(const struct btrfs_raid_bio *rbio,
621 unsigned int sector_nr)
622{
623 if (rbio->nr_data + 1 == rbio->real_stripes)
624 return NULL;
625 return rbio_stripe_sector(rbio, rbio->nr_data + 1, sector_nr);
626}
627
628/*
629 * The first stripe in the table for a logical address
630 * has the lock. rbios are added in one of three ways:
631 *
632 * 1) Nobody has the stripe locked yet. The rbio is given
633 * the lock and 0 is returned. The caller must start the IO
634 * themselves.
635 *
636 * 2) Someone has the stripe locked, but we're able to merge
637 * with the lock owner. The rbio is freed and the IO will
638 * start automatically along with the existing rbio. 1 is returned.
639 *
640 * 3) Someone has the stripe locked, but we're not able to merge.
641 * The rbio is added to the lock owner's plug list, or merged into
642 * an rbio already on the plug list. When the lock owner unlocks,
643 * the next rbio on the list is run and the IO is started automatically.
644 * 1 is returned
645 *
646 * If we return 0, the caller still owns the rbio and must continue with
647 * IO submission. If we return 1, the caller must assume the rbio has
648 * already been freed.
649 */
650static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
651{
652 struct btrfs_stripe_hash *h;
653 struct btrfs_raid_bio *cur;
654 struct btrfs_raid_bio *pending;
655 struct btrfs_raid_bio *freeit = NULL;
656 struct btrfs_raid_bio *cache_drop = NULL;
657 int ret = 0;
658
659 h = rbio->bioc->fs_info->stripe_hash_table->table + rbio_bucket(rbio);
660
661 spin_lock(&h->lock);
662 list_for_each_entry(cur, &h->hash_list, hash_list) {
663 if (cur->bioc->full_stripe_logical != rbio->bioc->full_stripe_logical)
664 continue;
665
666 spin_lock(&cur->bio_list_lock);
667
668 /* Can we steal this cached rbio's pages? */
669 if (bio_list_empty(&cur->bio_list) &&
670 list_empty(&cur->plug_list) &&
671 test_bit(RBIO_CACHE_BIT, &cur->flags) &&
672 !test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) {
673 list_del_init(&cur->hash_list);
674 refcount_dec(&cur->refs);
675
676 steal_rbio(cur, rbio);
677 cache_drop = cur;
678 spin_unlock(&cur->bio_list_lock);
679
680 goto lockit;
681 }
682
683 /* Can we merge into the lock owner? */
684 if (rbio_can_merge(cur, rbio)) {
685 merge_rbio(cur, rbio);
686 spin_unlock(&cur->bio_list_lock);
687 freeit = rbio;
688 ret = 1;
689 goto out;
690 }
691
692
693 /*
694 * We couldn't merge with the running rbio, see if we can merge
695 * with the pending ones. We don't have to check for rmw_locked
696 * because there is no way they are inside finish_rmw right now
697 */
698 list_for_each_entry(pending, &cur->plug_list, plug_list) {
699 if (rbio_can_merge(pending, rbio)) {
700 merge_rbio(pending, rbio);
701 spin_unlock(&cur->bio_list_lock);
702 freeit = rbio;
703 ret = 1;
704 goto out;
705 }
706 }
707
708 /*
709 * No merging, put us on the tail of the plug list, our rbio
710 * will be started with the currently running rbio unlocks
711 */
712 list_add_tail(&rbio->plug_list, &cur->plug_list);
713 spin_unlock(&cur->bio_list_lock);
714 ret = 1;
715 goto out;
716 }
717lockit:
718 refcount_inc(&rbio->refs);
719 list_add(&rbio->hash_list, &h->hash_list);
720out:
721 spin_unlock(&h->lock);
722 if (cache_drop)
723 remove_rbio_from_cache(cache_drop);
724 if (freeit)
725 free_raid_bio(freeit);
726 return ret;
727}
728
729static void recover_rbio_work_locked(struct work_struct *work);
730
731/*
732 * called as rmw or parity rebuild is completed. If the plug list has more
733 * rbios waiting for this stripe, the next one on the list will be started
734 */
735static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
736{
737 int bucket;
738 struct btrfs_stripe_hash *h;
739 int keep_cache = 0;
740
741 bucket = rbio_bucket(rbio);
742 h = rbio->bioc->fs_info->stripe_hash_table->table + bucket;
743
744 if (list_empty(&rbio->plug_list))
745 cache_rbio(rbio);
746
747 spin_lock(&h->lock);
748 spin_lock(&rbio->bio_list_lock);
749
750 if (!list_empty(&rbio->hash_list)) {
751 /*
752 * if we're still cached and there is no other IO
753 * to perform, just leave this rbio here for others
754 * to steal from later
755 */
756 if (list_empty(&rbio->plug_list) &&
757 test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
758 keep_cache = 1;
759 clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
760 BUG_ON(!bio_list_empty(&rbio->bio_list));
761 goto done;
762 }
763
764 list_del_init(&rbio->hash_list);
765 refcount_dec(&rbio->refs);
766
767 /*
768 * we use the plug list to hold all the rbios
769 * waiting for the chance to lock this stripe.
770 * hand the lock over to one of them.
771 */
772 if (!list_empty(&rbio->plug_list)) {
773 struct btrfs_raid_bio *next;
774 struct list_head *head = rbio->plug_list.next;
775
776 next = list_entry(head, struct btrfs_raid_bio,
777 plug_list);
778
779 list_del_init(&rbio->plug_list);
780
781 list_add(&next->hash_list, &h->hash_list);
782 refcount_inc(&next->refs);
783 spin_unlock(&rbio->bio_list_lock);
784 spin_unlock(&h->lock);
785
786 if (next->operation == BTRFS_RBIO_READ_REBUILD) {
787 start_async_work(next, recover_rbio_work_locked);
788 } else if (next->operation == BTRFS_RBIO_WRITE) {
789 steal_rbio(rbio, next);
790 start_async_work(next, rmw_rbio_work_locked);
791 } else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
792 steal_rbio(rbio, next);
793 start_async_work(next, scrub_rbio_work_locked);
794 }
795
796 goto done_nolock;
797 }
798 }
799done:
800 spin_unlock(&rbio->bio_list_lock);
801 spin_unlock(&h->lock);
802
803done_nolock:
804 if (!keep_cache)
805 remove_rbio_from_cache(rbio);
806}
807
808static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
809{
810 struct bio *next;
811
812 while (cur) {
813 next = cur->bi_next;
814 cur->bi_next = NULL;
815 cur->bi_status = err;
816 bio_endio(cur);
817 cur = next;
818 }
819}
820
821/*
822 * this frees the rbio and runs through all the bios in the
823 * bio_list and calls end_io on them
824 */
825static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err)
826{
827 struct bio *cur = bio_list_get(&rbio->bio_list);
828 struct bio *extra;
829
830 kfree(rbio->csum_buf);
831 bitmap_free(rbio->csum_bitmap);
832 rbio->csum_buf = NULL;
833 rbio->csum_bitmap = NULL;
834
835 /*
836 * Clear the data bitmap, as the rbio may be cached for later usage.
837 * do this before before unlock_stripe() so there will be no new bio
838 * for this bio.
839 */
840 bitmap_clear(&rbio->dbitmap, 0, rbio->stripe_nsectors);
841
842 /*
843 * At this moment, rbio->bio_list is empty, however since rbio does not
844 * always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the
845 * hash list, rbio may be merged with others so that rbio->bio_list
846 * becomes non-empty.
847 * Once unlock_stripe() is done, rbio->bio_list will not be updated any
848 * more and we can call bio_endio() on all queued bios.
849 */
850 unlock_stripe(rbio);
851 extra = bio_list_get(&rbio->bio_list);
852 free_raid_bio(rbio);
853
854 rbio_endio_bio_list(cur, err);
855 if (extra)
856 rbio_endio_bio_list(extra, err);
857}
858
859/*
860 * Get a sector pointer specified by its @stripe_nr and @sector_nr.
861 *
862 * @rbio: The raid bio
863 * @stripe_nr: Stripe number, valid range [0, real_stripe)
864 * @sector_nr: Sector number inside the stripe,
865 * valid range [0, stripe_nsectors)
866 * @bio_list_only: Whether to use sectors inside the bio list only.
867 *
868 * The read/modify/write code wants to reuse the original bio page as much
869 * as possible, and only use stripe_sectors as fallback.
870 */
871static struct sector_ptr *sector_in_rbio(struct btrfs_raid_bio *rbio,
872 int stripe_nr, int sector_nr,
873 bool bio_list_only)
874{
875 struct sector_ptr *sector;
876 int index;
877
878 ASSERT(stripe_nr >= 0 && stripe_nr < rbio->real_stripes);
879 ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
880
881 index = stripe_nr * rbio->stripe_nsectors + sector_nr;
882 ASSERT(index >= 0 && index < rbio->nr_sectors);
883
884 spin_lock(&rbio->bio_list_lock);
885 sector = &rbio->bio_sectors[index];
886 if (sector->page || bio_list_only) {
887 /* Don't return sector without a valid page pointer */
888 if (!sector->page)
889 sector = NULL;
890 spin_unlock(&rbio->bio_list_lock);
891 return sector;
892 }
893 spin_unlock(&rbio->bio_list_lock);
894
895 return &rbio->stripe_sectors[index];
896}
897
898/*
899 * allocation and initial setup for the btrfs_raid_bio. Not
900 * this does not allocate any pages for rbio->pages.
901 */
902static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
903 struct btrfs_io_context *bioc)
904{
905 const unsigned int real_stripes = bioc->num_stripes - bioc->replace_nr_stripes;
906 const unsigned int stripe_npages = BTRFS_STRIPE_LEN >> PAGE_SHIFT;
907 const unsigned int num_pages = stripe_npages * real_stripes;
908 const unsigned int stripe_nsectors =
909 BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
910 const unsigned int num_sectors = stripe_nsectors * real_stripes;
911 struct btrfs_raid_bio *rbio;
912
913 /* PAGE_SIZE must also be aligned to sectorsize for subpage support */
914 ASSERT(IS_ALIGNED(PAGE_SIZE, fs_info->sectorsize));
915 /*
916 * Our current stripe len should be fixed to 64k thus stripe_nsectors
917 * (at most 16) should be no larger than BITS_PER_LONG.
918 */
919 ASSERT(stripe_nsectors <= BITS_PER_LONG);
920
921 rbio = kzalloc(sizeof(*rbio), GFP_NOFS);
922 if (!rbio)
923 return ERR_PTR(-ENOMEM);
924 rbio->stripe_pages = kcalloc(num_pages, sizeof(struct page *),
925 GFP_NOFS);
926 rbio->bio_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
927 GFP_NOFS);
928 rbio->stripe_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
929 GFP_NOFS);
930 rbio->finish_pointers = kcalloc(real_stripes, sizeof(void *), GFP_NOFS);
931 rbio->error_bitmap = bitmap_zalloc(num_sectors, GFP_NOFS);
932
933 if (!rbio->stripe_pages || !rbio->bio_sectors || !rbio->stripe_sectors ||
934 !rbio->finish_pointers || !rbio->error_bitmap) {
935 free_raid_bio_pointers(rbio);
936 kfree(rbio);
937 return ERR_PTR(-ENOMEM);
938 }
939
940 bio_list_init(&rbio->bio_list);
941 init_waitqueue_head(&rbio->io_wait);
942 INIT_LIST_HEAD(&rbio->plug_list);
943 spin_lock_init(&rbio->bio_list_lock);
944 INIT_LIST_HEAD(&rbio->stripe_cache);
945 INIT_LIST_HEAD(&rbio->hash_list);
946 btrfs_get_bioc(bioc);
947 rbio->bioc = bioc;
948 rbio->nr_pages = num_pages;
949 rbio->nr_sectors = num_sectors;
950 rbio->real_stripes = real_stripes;
951 rbio->stripe_npages = stripe_npages;
952 rbio->stripe_nsectors = stripe_nsectors;
953 refcount_set(&rbio->refs, 1);
954 atomic_set(&rbio->stripes_pending, 0);
955
956 ASSERT(btrfs_nr_parity_stripes(bioc->map_type));
957 rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type);
958
959 return rbio;
960}
961
962/* allocate pages for all the stripes in the bio, including parity */
963static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
964{
965 int ret;
966
967 ret = btrfs_alloc_page_array(rbio->nr_pages, rbio->stripe_pages, 0);
968 if (ret < 0)
969 return ret;
970 /* Mapping all sectors */
971 index_stripe_sectors(rbio);
972 return 0;
973}
974
975/* only allocate pages for p/q stripes */
976static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
977{
978 const int data_pages = rbio->nr_data * rbio->stripe_npages;
979 int ret;
980
981 ret = btrfs_alloc_page_array(rbio->nr_pages - data_pages,
982 rbio->stripe_pages + data_pages, 0);
983 if (ret < 0)
984 return ret;
985
986 index_stripe_sectors(rbio);
987 return 0;
988}
989
990/*
991 * Return the total number of errors found in the vertical stripe of @sector_nr.
992 *
993 * @faila and @failb will also be updated to the first and second stripe
994 * number of the errors.
995 */
996static int get_rbio_veritical_errors(struct btrfs_raid_bio *rbio, int sector_nr,
997 int *faila, int *failb)
998{
999 int stripe_nr;
1000 int found_errors = 0;
1001
1002 if (faila || failb) {
1003 /*
1004 * Both @faila and @failb should be valid pointers if any of
1005 * them is specified.
1006 */
1007 ASSERT(faila && failb);
1008 *faila = -1;
1009 *failb = -1;
1010 }
1011
1012 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1013 int total_sector_nr = stripe_nr * rbio->stripe_nsectors + sector_nr;
1014
1015 if (test_bit(total_sector_nr, rbio->error_bitmap)) {
1016 found_errors++;
1017 if (faila) {
1018 /* Update faila and failb. */
1019 if (*faila < 0)
1020 *faila = stripe_nr;
1021 else if (*failb < 0)
1022 *failb = stripe_nr;
1023 }
1024 }
1025 }
1026 return found_errors;
1027}
1028
1029/*
1030 * Add a single sector @sector into our list of bios for IO.
1031 *
1032 * Return 0 if everything went well.
1033 * Return <0 for error.
1034 */
1035static int rbio_add_io_sector(struct btrfs_raid_bio *rbio,
1036 struct bio_list *bio_list,
1037 struct sector_ptr *sector,
1038 unsigned int stripe_nr,
1039 unsigned int sector_nr,
1040 enum req_op op)
1041{
1042 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1043 struct bio *last = bio_list->tail;
1044 int ret;
1045 struct bio *bio;
1046 struct btrfs_io_stripe *stripe;
1047 u64 disk_start;
1048
1049 /*
1050 * Note: here stripe_nr has taken device replace into consideration,
1051 * thus it can be larger than rbio->real_stripe.
1052 * So here we check against bioc->num_stripes, not rbio->real_stripes.
1053 */
1054 ASSERT(stripe_nr >= 0 && stripe_nr < rbio->bioc->num_stripes);
1055 ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
1056 ASSERT(sector->page);
1057
1058 stripe = &rbio->bioc->stripes[stripe_nr];
1059 disk_start = stripe->physical + sector_nr * sectorsize;
1060
1061 /* if the device is missing, just fail this stripe */
1062 if (!stripe->dev->bdev) {
1063 int found_errors;
1064
1065 set_bit(stripe_nr * rbio->stripe_nsectors + sector_nr,
1066 rbio->error_bitmap);
1067
1068 /* Check if we have reached tolerance early. */
1069 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
1070 NULL, NULL);
1071 if (found_errors > rbio->bioc->max_errors)
1072 return -EIO;
1073 return 0;
1074 }
1075
1076 /* see if we can add this page onto our existing bio */
1077 if (last) {
1078 u64 last_end = last->bi_iter.bi_sector << SECTOR_SHIFT;
1079 last_end += last->bi_iter.bi_size;
1080
1081 /*
1082 * we can't merge these if they are from different
1083 * devices or if they are not contiguous
1084 */
1085 if (last_end == disk_start && !last->bi_status &&
1086 last->bi_bdev == stripe->dev->bdev) {
1087 ret = bio_add_page(last, sector->page, sectorsize,
1088 sector->pgoff);
1089 if (ret == sectorsize)
1090 return 0;
1091 }
1092 }
1093
1094 /* put a new bio on the list */
1095 bio = bio_alloc(stripe->dev->bdev,
1096 max(BTRFS_STRIPE_LEN >> PAGE_SHIFT, 1),
1097 op, GFP_NOFS);
1098 bio->bi_iter.bi_sector = disk_start >> SECTOR_SHIFT;
1099 bio->bi_private = rbio;
1100
1101 __bio_add_page(bio, sector->page, sectorsize, sector->pgoff);
1102 bio_list_add(bio_list, bio);
1103 return 0;
1104}
1105
1106static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)
1107{
1108 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1109 struct bio_vec bvec;
1110 struct bvec_iter iter;
1111 u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1112 rbio->bioc->full_stripe_logical;
1113
1114 bio_for_each_segment(bvec, bio, iter) {
1115 u32 bvec_offset;
1116
1117 for (bvec_offset = 0; bvec_offset < bvec.bv_len;
1118 bvec_offset += sectorsize, offset += sectorsize) {
1119 int index = offset / sectorsize;
1120 struct sector_ptr *sector = &rbio->bio_sectors[index];
1121
1122 sector->page = bvec.bv_page;
1123 sector->pgoff = bvec.bv_offset + bvec_offset;
1124 ASSERT(sector->pgoff < PAGE_SIZE);
1125 }
1126 }
1127}
1128
1129/*
1130 * helper function to walk our bio list and populate the bio_pages array with
1131 * the result. This seems expensive, but it is faster than constantly
1132 * searching through the bio list as we setup the IO in finish_rmw or stripe
1133 * reconstruction.
1134 *
1135 * This must be called before you trust the answers from page_in_rbio
1136 */
1137static void index_rbio_pages(struct btrfs_raid_bio *rbio)
1138{
1139 struct bio *bio;
1140
1141 spin_lock(&rbio->bio_list_lock);
1142 bio_list_for_each(bio, &rbio->bio_list)
1143 index_one_bio(rbio, bio);
1144
1145 spin_unlock(&rbio->bio_list_lock);
1146}
1147
1148static void bio_get_trace_info(struct btrfs_raid_bio *rbio, struct bio *bio,
1149 struct raid56_bio_trace_info *trace_info)
1150{
1151 const struct btrfs_io_context *bioc = rbio->bioc;
1152 int i;
1153
1154 ASSERT(bioc);
1155
1156 /* We rely on bio->bi_bdev to find the stripe number. */
1157 if (!bio->bi_bdev)
1158 goto not_found;
1159
1160 for (i = 0; i < bioc->num_stripes; i++) {
1161 if (bio->bi_bdev != bioc->stripes[i].dev->bdev)
1162 continue;
1163 trace_info->stripe_nr = i;
1164 trace_info->devid = bioc->stripes[i].dev->devid;
1165 trace_info->offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1166 bioc->stripes[i].physical;
1167 return;
1168 }
1169
1170not_found:
1171 trace_info->devid = -1;
1172 trace_info->offset = -1;
1173 trace_info->stripe_nr = -1;
1174}
1175
1176static inline void bio_list_put(struct bio_list *bio_list)
1177{
1178 struct bio *bio;
1179
1180 while ((bio = bio_list_pop(bio_list)))
1181 bio_put(bio);
1182}
1183
1184/* Generate PQ for one vertical stripe. */
1185static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr)
1186{
1187 void **pointers = rbio->finish_pointers;
1188 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1189 struct sector_ptr *sector;
1190 int stripe;
1191 const bool has_qstripe = rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6;
1192
1193 /* First collect one sector from each data stripe */
1194 for (stripe = 0; stripe < rbio->nr_data; stripe++) {
1195 sector = sector_in_rbio(rbio, stripe, sectornr, 0);
1196 pointers[stripe] = kmap_local_page(sector->page) +
1197 sector->pgoff;
1198 }
1199
1200 /* Then add the parity stripe */
1201 sector = rbio_pstripe_sector(rbio, sectornr);
1202 sector->uptodate = 1;
1203 pointers[stripe++] = kmap_local_page(sector->page) + sector->pgoff;
1204
1205 if (has_qstripe) {
1206 /*
1207 * RAID6, add the qstripe and call the library function
1208 * to fill in our p/q
1209 */
1210 sector = rbio_qstripe_sector(rbio, sectornr);
1211 sector->uptodate = 1;
1212 pointers[stripe++] = kmap_local_page(sector->page) +
1213 sector->pgoff;
1214
1215 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
1216 pointers);
1217 } else {
1218 /* raid5 */
1219 memcpy(pointers[rbio->nr_data], pointers[0], sectorsize);
1220 run_xor(pointers + 1, rbio->nr_data - 1, sectorsize);
1221 }
1222 for (stripe = stripe - 1; stripe >= 0; stripe--)
1223 kunmap_local(pointers[stripe]);
1224}
1225
1226static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio,
1227 struct bio_list *bio_list)
1228{
1229 /* The total sector number inside the full stripe. */
1230 int total_sector_nr;
1231 int sectornr;
1232 int stripe;
1233 int ret;
1234
1235 ASSERT(bio_list_size(bio_list) == 0);
1236
1237 /* We should have at least one data sector. */
1238 ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));
1239
1240 /*
1241 * Reset errors, as we may have errors inherited from from degraded
1242 * write.
1243 */
1244 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
1245
1246 /*
1247 * Start assembly. Make bios for everything from the higher layers (the
1248 * bio_list in our rbio) and our P/Q. Ignore everything else.
1249 */
1250 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1251 total_sector_nr++) {
1252 struct sector_ptr *sector;
1253
1254 stripe = total_sector_nr / rbio->stripe_nsectors;
1255 sectornr = total_sector_nr % rbio->stripe_nsectors;
1256
1257 /* This vertical stripe has no data, skip it. */
1258 if (!test_bit(sectornr, &rbio->dbitmap))
1259 continue;
1260
1261 if (stripe < rbio->nr_data) {
1262 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1263 if (!sector)
1264 continue;
1265 } else {
1266 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1267 }
1268
1269 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
1270 sectornr, REQ_OP_WRITE);
1271 if (ret)
1272 goto error;
1273 }
1274
1275 if (likely(!rbio->bioc->replace_nr_stripes))
1276 return 0;
1277
1278 /*
1279 * Make a copy for the replace target device.
1280 *
1281 * Thus the source stripe number (in replace_stripe_src) should be valid.
1282 */
1283 ASSERT(rbio->bioc->replace_stripe_src >= 0);
1284
1285 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1286 total_sector_nr++) {
1287 struct sector_ptr *sector;
1288
1289 stripe = total_sector_nr / rbio->stripe_nsectors;
1290 sectornr = total_sector_nr % rbio->stripe_nsectors;
1291
1292 /*
1293 * For RAID56, there is only one device that can be replaced,
1294 * and replace_stripe_src[0] indicates the stripe number we
1295 * need to copy from.
1296 */
1297 if (stripe != rbio->bioc->replace_stripe_src) {
1298 /*
1299 * We can skip the whole stripe completely, note
1300 * total_sector_nr will be increased by one anyway.
1301 */
1302 ASSERT(sectornr == 0);
1303 total_sector_nr += rbio->stripe_nsectors - 1;
1304 continue;
1305 }
1306
1307 /* This vertical stripe has no data, skip it. */
1308 if (!test_bit(sectornr, &rbio->dbitmap))
1309 continue;
1310
1311 if (stripe < rbio->nr_data) {
1312 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1313 if (!sector)
1314 continue;
1315 } else {
1316 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1317 }
1318
1319 ret = rbio_add_io_sector(rbio, bio_list, sector,
1320 rbio->real_stripes,
1321 sectornr, REQ_OP_WRITE);
1322 if (ret)
1323 goto error;
1324 }
1325
1326 return 0;
1327error:
1328 bio_list_put(bio_list);
1329 return -EIO;
1330}
1331
1332static void set_rbio_range_error(struct btrfs_raid_bio *rbio, struct bio *bio)
1333{
1334 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1335 u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1336 rbio->bioc->full_stripe_logical;
1337 int total_nr_sector = offset >> fs_info->sectorsize_bits;
1338
1339 ASSERT(total_nr_sector < rbio->nr_data * rbio->stripe_nsectors);
1340
1341 bitmap_set(rbio->error_bitmap, total_nr_sector,
1342 bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
1343
1344 /*
1345 * Special handling for raid56_alloc_missing_rbio() used by
1346 * scrub/replace. Unlike call path in raid56_parity_recover(), they
1347 * pass an empty bio here. Thus we have to find out the missing device
1348 * and mark the stripe error instead.
1349 */
1350 if (bio->bi_iter.bi_size == 0) {
1351 bool found_missing = false;
1352 int stripe_nr;
1353
1354 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1355 if (!rbio->bioc->stripes[stripe_nr].dev->bdev) {
1356 found_missing = true;
1357 bitmap_set(rbio->error_bitmap,
1358 stripe_nr * rbio->stripe_nsectors,
1359 rbio->stripe_nsectors);
1360 }
1361 }
1362 ASSERT(found_missing);
1363 }
1364}
1365
1366/*
1367 * For subpage case, we can no longer set page Up-to-date directly for
1368 * stripe_pages[], thus we need to locate the sector.
1369 */
1370static struct sector_ptr *find_stripe_sector(struct btrfs_raid_bio *rbio,
1371 struct page *page,
1372 unsigned int pgoff)
1373{
1374 int i;
1375
1376 for (i = 0; i < rbio->nr_sectors; i++) {
1377 struct sector_ptr *sector = &rbio->stripe_sectors[i];
1378
1379 if (sector->page == page && sector->pgoff == pgoff)
1380 return sector;
1381 }
1382 return NULL;
1383}
1384
1385/*
1386 * this sets each page in the bio uptodate. It should only be used on private
1387 * rbio pages, nothing that comes in from the higher layers
1388 */
1389static void set_bio_pages_uptodate(struct btrfs_raid_bio *rbio, struct bio *bio)
1390{
1391 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1392 struct bio_vec *bvec;
1393 struct bvec_iter_all iter_all;
1394
1395 ASSERT(!bio_flagged(bio, BIO_CLONED));
1396
1397 bio_for_each_segment_all(bvec, bio, iter_all) {
1398 struct sector_ptr *sector;
1399 int pgoff;
1400
1401 for (pgoff = bvec->bv_offset; pgoff - bvec->bv_offset < bvec->bv_len;
1402 pgoff += sectorsize) {
1403 sector = find_stripe_sector(rbio, bvec->bv_page, pgoff);
1404 ASSERT(sector);
1405 if (sector)
1406 sector->uptodate = 1;
1407 }
1408 }
1409}
1410
1411static int get_bio_sector_nr(struct btrfs_raid_bio *rbio, struct bio *bio)
1412{
1413 struct bio_vec *bv = bio_first_bvec_all(bio);
1414 int i;
1415
1416 for (i = 0; i < rbio->nr_sectors; i++) {
1417 struct sector_ptr *sector;
1418
1419 sector = &rbio->stripe_sectors[i];
1420 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1421 break;
1422 sector = &rbio->bio_sectors[i];
1423 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1424 break;
1425 }
1426 ASSERT(i < rbio->nr_sectors);
1427 return i;
1428}
1429
1430static void rbio_update_error_bitmap(struct btrfs_raid_bio *rbio, struct bio *bio)
1431{
1432 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1433 u32 bio_size = 0;
1434 struct bio_vec *bvec;
1435 int i;
1436
1437 bio_for_each_bvec_all(bvec, bio, i)
1438 bio_size += bvec->bv_len;
1439
1440 /*
1441 * Since we can have multiple bios touching the error_bitmap, we cannot
1442 * call bitmap_set() without protection.
1443 *
1444 * Instead use set_bit() for each bit, as set_bit() itself is atomic.
1445 */
1446 for (i = total_sector_nr; i < total_sector_nr +
1447 (bio_size >> rbio->bioc->fs_info->sectorsize_bits); i++)
1448 set_bit(i, rbio->error_bitmap);
1449}
1450
1451/* Verify the data sectors at read time. */
1452static void verify_bio_data_sectors(struct btrfs_raid_bio *rbio,
1453 struct bio *bio)
1454{
1455 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1456 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1457 struct bio_vec *bvec;
1458 struct bvec_iter_all iter_all;
1459
1460 /* No data csum for the whole stripe, no need to verify. */
1461 if (!rbio->csum_bitmap || !rbio->csum_buf)
1462 return;
1463
1464 /* P/Q stripes, they have no data csum to verify against. */
1465 if (total_sector_nr >= rbio->nr_data * rbio->stripe_nsectors)
1466 return;
1467
1468 bio_for_each_segment_all(bvec, bio, iter_all) {
1469 int bv_offset;
1470
1471 for (bv_offset = bvec->bv_offset;
1472 bv_offset < bvec->bv_offset + bvec->bv_len;
1473 bv_offset += fs_info->sectorsize, total_sector_nr++) {
1474 u8 csum_buf[BTRFS_CSUM_SIZE];
1475 u8 *expected_csum = rbio->csum_buf +
1476 total_sector_nr * fs_info->csum_size;
1477 int ret;
1478
1479 /* No csum for this sector, skip to the next sector. */
1480 if (!test_bit(total_sector_nr, rbio->csum_bitmap))
1481 continue;
1482
1483 ret = btrfs_check_sector_csum(fs_info, bvec->bv_page,
1484 bv_offset, csum_buf, expected_csum);
1485 if (ret < 0)
1486 set_bit(total_sector_nr, rbio->error_bitmap);
1487 }
1488 }
1489}
1490
1491static void raid_wait_read_end_io(struct bio *bio)
1492{
1493 struct btrfs_raid_bio *rbio = bio->bi_private;
1494
1495 if (bio->bi_status) {
1496 rbio_update_error_bitmap(rbio, bio);
1497 } else {
1498 set_bio_pages_uptodate(rbio, bio);
1499 verify_bio_data_sectors(rbio, bio);
1500 }
1501
1502 bio_put(bio);
1503 if (atomic_dec_and_test(&rbio->stripes_pending))
1504 wake_up(&rbio->io_wait);
1505}
1506
1507static void submit_read_wait_bio_list(struct btrfs_raid_bio *rbio,
1508 struct bio_list *bio_list)
1509{
1510 struct bio *bio;
1511
1512 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
1513 while ((bio = bio_list_pop(bio_list))) {
1514 bio->bi_end_io = raid_wait_read_end_io;
1515
1516 if (trace_raid56_read_enabled()) {
1517 struct raid56_bio_trace_info trace_info = { 0 };
1518
1519 bio_get_trace_info(rbio, bio, &trace_info);
1520 trace_raid56_read(rbio, bio, &trace_info);
1521 }
1522 submit_bio(bio);
1523 }
1524
1525 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
1526}
1527
1528static int alloc_rbio_data_pages(struct btrfs_raid_bio *rbio)
1529{
1530 const int data_pages = rbio->nr_data * rbio->stripe_npages;
1531 int ret;
1532
1533 ret = btrfs_alloc_page_array(data_pages, rbio->stripe_pages, 0);
1534 if (ret < 0)
1535 return ret;
1536
1537 index_stripe_sectors(rbio);
1538 return 0;
1539}
1540
1541/*
1542 * We use plugging call backs to collect full stripes.
1543 * Any time we get a partial stripe write while plugged
1544 * we collect it into a list. When the unplug comes down,
1545 * we sort the list by logical block number and merge
1546 * everything we can into the same rbios
1547 */
1548struct btrfs_plug_cb {
1549 struct blk_plug_cb cb;
1550 struct btrfs_fs_info *info;
1551 struct list_head rbio_list;
1552};
1553
1554/*
1555 * rbios on the plug list are sorted for easier merging.
1556 */
1557static int plug_cmp(void *priv, const struct list_head *a,
1558 const struct list_head *b)
1559{
1560 const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
1561 plug_list);
1562 const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
1563 plug_list);
1564 u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
1565 u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
1566
1567 if (a_sector < b_sector)
1568 return -1;
1569 if (a_sector > b_sector)
1570 return 1;
1571 return 0;
1572}
1573
1574static void raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
1575{
1576 struct btrfs_plug_cb *plug = container_of(cb, struct btrfs_plug_cb, cb);
1577 struct btrfs_raid_bio *cur;
1578 struct btrfs_raid_bio *last = NULL;
1579
1580 list_sort(NULL, &plug->rbio_list, plug_cmp);
1581
1582 while (!list_empty(&plug->rbio_list)) {
1583 cur = list_entry(plug->rbio_list.next,
1584 struct btrfs_raid_bio, plug_list);
1585 list_del_init(&cur->plug_list);
1586
1587 if (rbio_is_full(cur)) {
1588 /* We have a full stripe, queue it down. */
1589 start_async_work(cur, rmw_rbio_work);
1590 continue;
1591 }
1592 if (last) {
1593 if (rbio_can_merge(last, cur)) {
1594 merge_rbio(last, cur);
1595 free_raid_bio(cur);
1596 continue;
1597 }
1598 start_async_work(last, rmw_rbio_work);
1599 }
1600 last = cur;
1601 }
1602 if (last)
1603 start_async_work(last, rmw_rbio_work);
1604 kfree(plug);
1605}
1606
1607/* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */
1608static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio)
1609{
1610 const struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1611 const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT;
1612 const u64 full_stripe_start = rbio->bioc->full_stripe_logical;
1613 const u32 orig_len = orig_bio->bi_iter.bi_size;
1614 const u32 sectorsize = fs_info->sectorsize;
1615 u64 cur_logical;
1616
1617 ASSERT(orig_logical >= full_stripe_start &&
1618 orig_logical + orig_len <= full_stripe_start +
1619 rbio->nr_data * BTRFS_STRIPE_LEN);
1620
1621 bio_list_add(&rbio->bio_list, orig_bio);
1622 rbio->bio_list_bytes += orig_bio->bi_iter.bi_size;
1623
1624 /* Update the dbitmap. */
1625 for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len;
1626 cur_logical += sectorsize) {
1627 int bit = ((u32)(cur_logical - full_stripe_start) >>
1628 fs_info->sectorsize_bits) % rbio->stripe_nsectors;
1629
1630 set_bit(bit, &rbio->dbitmap);
1631 }
1632}
1633
1634/*
1635 * our main entry point for writes from the rest of the FS.
1636 */
1637void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
1638{
1639 struct btrfs_fs_info *fs_info = bioc->fs_info;
1640 struct btrfs_raid_bio *rbio;
1641 struct btrfs_plug_cb *plug = NULL;
1642 struct blk_plug_cb *cb;
1643
1644 rbio = alloc_rbio(fs_info, bioc);
1645 if (IS_ERR(rbio)) {
1646 bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
1647 bio_endio(bio);
1648 return;
1649 }
1650 rbio->operation = BTRFS_RBIO_WRITE;
1651 rbio_add_bio(rbio, bio);
1652
1653 /*
1654 * Don't plug on full rbios, just get them out the door
1655 * as quickly as we can
1656 */
1657 if (!rbio_is_full(rbio)) {
1658 cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
1659 if (cb) {
1660 plug = container_of(cb, struct btrfs_plug_cb, cb);
1661 if (!plug->info) {
1662 plug->info = fs_info;
1663 INIT_LIST_HEAD(&plug->rbio_list);
1664 }
1665 list_add_tail(&rbio->plug_list, &plug->rbio_list);
1666 return;
1667 }
1668 }
1669
1670 /*
1671 * Either we don't have any existing plug, or we're doing a full stripe,
1672 * queue the rmw work now.
1673 */
1674 start_async_work(rbio, rmw_rbio_work);
1675}
1676
1677static int verify_one_sector(struct btrfs_raid_bio *rbio,
1678 int stripe_nr, int sector_nr)
1679{
1680 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1681 struct sector_ptr *sector;
1682 u8 csum_buf[BTRFS_CSUM_SIZE];
1683 u8 *csum_expected;
1684 int ret;
1685
1686 if (!rbio->csum_bitmap || !rbio->csum_buf)
1687 return 0;
1688
1689 /* No way to verify P/Q as they are not covered by data csum. */
1690 if (stripe_nr >= rbio->nr_data)
1691 return 0;
1692 /*
1693 * If we're rebuilding a read, we have to use pages from the
1694 * bio list if possible.
1695 */
1696 if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
1697 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1698 } else {
1699 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1700 }
1701
1702 ASSERT(sector->page);
1703
1704 csum_expected = rbio->csum_buf +
1705 (stripe_nr * rbio->stripe_nsectors + sector_nr) *
1706 fs_info->csum_size;
1707 ret = btrfs_check_sector_csum(fs_info, sector->page, sector->pgoff,
1708 csum_buf, csum_expected);
1709 return ret;
1710}
1711
1712/*
1713 * Recover a vertical stripe specified by @sector_nr.
1714 * @*pointers are the pre-allocated pointers by the caller, so we don't
1715 * need to allocate/free the pointers again and again.
1716 */
1717static int recover_vertical(struct btrfs_raid_bio *rbio, int sector_nr,
1718 void **pointers, void **unmap_array)
1719{
1720 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1721 struct sector_ptr *sector;
1722 const u32 sectorsize = fs_info->sectorsize;
1723 int found_errors;
1724 int faila;
1725 int failb;
1726 int stripe_nr;
1727 int ret = 0;
1728
1729 /*
1730 * Now we just use bitmap to mark the horizontal stripes in
1731 * which we have data when doing parity scrub.
1732 */
1733 if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
1734 !test_bit(sector_nr, &rbio->dbitmap))
1735 return 0;
1736
1737 found_errors = get_rbio_veritical_errors(rbio, sector_nr, &faila,
1738 &failb);
1739 /*
1740 * No errors in the vertical stripe, skip it. Can happen for recovery
1741 * which only part of a stripe failed csum check.
1742 */
1743 if (!found_errors)
1744 return 0;
1745
1746 if (found_errors > rbio->bioc->max_errors)
1747 return -EIO;
1748
1749 /*
1750 * Setup our array of pointers with sectors from each stripe
1751 *
1752 * NOTE: store a duplicate array of pointers to preserve the
1753 * pointer order.
1754 */
1755 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1756 /*
1757 * If we're rebuilding a read, we have to use pages from the
1758 * bio list if possible.
1759 */
1760 if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
1761 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1762 } else {
1763 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1764 }
1765 ASSERT(sector->page);
1766 pointers[stripe_nr] = kmap_local_page(sector->page) +
1767 sector->pgoff;
1768 unmap_array[stripe_nr] = pointers[stripe_nr];
1769 }
1770
1771 /* All raid6 handling here */
1772 if (rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6) {
1773 /* Single failure, rebuild from parity raid5 style */
1774 if (failb < 0) {
1775 if (faila == rbio->nr_data)
1776 /*
1777 * Just the P stripe has failed, without
1778 * a bad data or Q stripe.
1779 * We have nothing to do, just skip the
1780 * recovery for this stripe.
1781 */
1782 goto cleanup;
1783 /*
1784 * a single failure in raid6 is rebuilt
1785 * in the pstripe code below
1786 */
1787 goto pstripe;
1788 }
1789
1790 /*
1791 * If the q stripe is failed, do a pstripe reconstruction from
1792 * the xors.
1793 * If both the q stripe and the P stripe are failed, we're
1794 * here due to a crc mismatch and we can't give them the
1795 * data they want.
1796 */
1797 if (failb == rbio->real_stripes - 1) {
1798 if (faila == rbio->real_stripes - 2)
1799 /*
1800 * Only P and Q are corrupted.
1801 * We only care about data stripes recovery,
1802 * can skip this vertical stripe.
1803 */
1804 goto cleanup;
1805 /*
1806 * Otherwise we have one bad data stripe and
1807 * a good P stripe. raid5!
1808 */
1809 goto pstripe;
1810 }
1811
1812 if (failb == rbio->real_stripes - 2) {
1813 raid6_datap_recov(rbio->real_stripes, sectorsize,
1814 faila, pointers);
1815 } else {
1816 raid6_2data_recov(rbio->real_stripes, sectorsize,
1817 faila, failb, pointers);
1818 }
1819 } else {
1820 void *p;
1821
1822 /* Rebuild from P stripe here (raid5 or raid6). */
1823 ASSERT(failb == -1);
1824pstripe:
1825 /* Copy parity block into failed block to start with */
1826 memcpy(pointers[faila], pointers[rbio->nr_data], sectorsize);
1827
1828 /* Rearrange the pointer array */
1829 p = pointers[faila];
1830 for (stripe_nr = faila; stripe_nr < rbio->nr_data - 1;
1831 stripe_nr++)
1832 pointers[stripe_nr] = pointers[stripe_nr + 1];
1833 pointers[rbio->nr_data - 1] = p;
1834
1835 /* Xor in the rest */
1836 run_xor(pointers, rbio->nr_data - 1, sectorsize);
1837
1838 }
1839
1840 /*
1841 * No matter if this is a RMW or recovery, we should have all
1842 * failed sectors repaired in the vertical stripe, thus they are now
1843 * uptodate.
1844 * Especially if we determine to cache the rbio, we need to
1845 * have at least all data sectors uptodate.
1846 *
1847 * If possible, also check if the repaired sector matches its data
1848 * checksum.
1849 */
1850 if (faila >= 0) {
1851 ret = verify_one_sector(rbio, faila, sector_nr);
1852 if (ret < 0)
1853 goto cleanup;
1854
1855 sector = rbio_stripe_sector(rbio, faila, sector_nr);
1856 sector->uptodate = 1;
1857 }
1858 if (failb >= 0) {
1859 ret = verify_one_sector(rbio, failb, sector_nr);
1860 if (ret < 0)
1861 goto cleanup;
1862
1863 sector = rbio_stripe_sector(rbio, failb, sector_nr);
1864 sector->uptodate = 1;
1865 }
1866
1867cleanup:
1868 for (stripe_nr = rbio->real_stripes - 1; stripe_nr >= 0; stripe_nr--)
1869 kunmap_local(unmap_array[stripe_nr]);
1870 return ret;
1871}
1872
1873static int recover_sectors(struct btrfs_raid_bio *rbio)
1874{
1875 void **pointers = NULL;
1876 void **unmap_array = NULL;
1877 int sectornr;
1878 int ret = 0;
1879
1880 /*
1881 * @pointers array stores the pointer for each sector.
1882 *
1883 * @unmap_array stores copy of pointers that does not get reordered
1884 * during reconstruction so that kunmap_local works.
1885 */
1886 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1887 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1888 if (!pointers || !unmap_array) {
1889 ret = -ENOMEM;
1890 goto out;
1891 }
1892
1893 if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
1894 spin_lock(&rbio->bio_list_lock);
1895 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
1896 spin_unlock(&rbio->bio_list_lock);
1897 }
1898
1899 index_rbio_pages(rbio);
1900
1901 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
1902 ret = recover_vertical(rbio, sectornr, pointers, unmap_array);
1903 if (ret < 0)
1904 break;
1905 }
1906
1907out:
1908 kfree(pointers);
1909 kfree(unmap_array);
1910 return ret;
1911}
1912
1913static void recover_rbio(struct btrfs_raid_bio *rbio)
1914{
1915 struct bio_list bio_list = BIO_EMPTY_LIST;
1916 int total_sector_nr;
1917 int ret = 0;
1918
1919 /*
1920 * Either we're doing recover for a read failure or degraded write,
1921 * caller should have set error bitmap correctly.
1922 */
1923 ASSERT(bitmap_weight(rbio->error_bitmap, rbio->nr_sectors));
1924
1925 /* For recovery, we need to read all sectors including P/Q. */
1926 ret = alloc_rbio_pages(rbio);
1927 if (ret < 0)
1928 goto out;
1929
1930 index_rbio_pages(rbio);
1931
1932 /*
1933 * Read everything that hasn't failed. However this time we will
1934 * not trust any cached sector.
1935 * As we may read out some stale data but higher layer is not reading
1936 * that stale part.
1937 *
1938 * So here we always re-read everything in recovery path.
1939 */
1940 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1941 total_sector_nr++) {
1942 int stripe = total_sector_nr / rbio->stripe_nsectors;
1943 int sectornr = total_sector_nr % rbio->stripe_nsectors;
1944 struct sector_ptr *sector;
1945
1946 /*
1947 * Skip the range which has error. It can be a range which is
1948 * marked error (for csum mismatch), or it can be a missing
1949 * device.
1950 */
1951 if (!rbio->bioc->stripes[stripe].dev->bdev ||
1952 test_bit(total_sector_nr, rbio->error_bitmap)) {
1953 /*
1954 * Also set the error bit for missing device, which
1955 * may not yet have its error bit set.
1956 */
1957 set_bit(total_sector_nr, rbio->error_bitmap);
1958 continue;
1959 }
1960
1961 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1962 ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
1963 sectornr, REQ_OP_READ);
1964 if (ret < 0) {
1965 bio_list_put(&bio_list);
1966 goto out;
1967 }
1968 }
1969
1970 submit_read_wait_bio_list(rbio, &bio_list);
1971 ret = recover_sectors(rbio);
1972out:
1973 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
1974}
1975
1976static void recover_rbio_work(struct work_struct *work)
1977{
1978 struct btrfs_raid_bio *rbio;
1979
1980 rbio = container_of(work, struct btrfs_raid_bio, work);
1981 if (!lock_stripe_add(rbio))
1982 recover_rbio(rbio);
1983}
1984
1985static void recover_rbio_work_locked(struct work_struct *work)
1986{
1987 recover_rbio(container_of(work, struct btrfs_raid_bio, work));
1988}
1989
1990static void set_rbio_raid6_extra_error(struct btrfs_raid_bio *rbio, int mirror_num)
1991{
1992 bool found = false;
1993 int sector_nr;
1994
1995 /*
1996 * This is for RAID6 extra recovery tries, thus mirror number should
1997 * be large than 2.
1998 * Mirror 1 means read from data stripes. Mirror 2 means rebuild using
1999 * RAID5 methods.
2000 */
2001 ASSERT(mirror_num > 2);
2002 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2003 int found_errors;
2004 int faila;
2005 int failb;
2006
2007 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2008 &faila, &failb);
2009 /* This vertical stripe doesn't have errors. */
2010 if (!found_errors)
2011 continue;
2012
2013 /*
2014 * If we found errors, there should be only one error marked
2015 * by previous set_rbio_range_error().
2016 */
2017 ASSERT(found_errors == 1);
2018 found = true;
2019
2020 /* Now select another stripe to mark as error. */
2021 failb = rbio->real_stripes - (mirror_num - 1);
2022 if (failb <= faila)
2023 failb--;
2024
2025 /* Set the extra bit in error bitmap. */
2026 if (failb >= 0)
2027 set_bit(failb * rbio->stripe_nsectors + sector_nr,
2028 rbio->error_bitmap);
2029 }
2030
2031 /* We should found at least one vertical stripe with error.*/
2032 ASSERT(found);
2033}
2034
2035/*
2036 * the main entry point for reads from the higher layers. This
2037 * is really only called when the normal read path had a failure,
2038 * so we assume the bio they send down corresponds to a failed part
2039 * of the drive.
2040 */
2041void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
2042 int mirror_num)
2043{
2044 struct btrfs_fs_info *fs_info = bioc->fs_info;
2045 struct btrfs_raid_bio *rbio;
2046
2047 rbio = alloc_rbio(fs_info, bioc);
2048 if (IS_ERR(rbio)) {
2049 bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
2050 bio_endio(bio);
2051 return;
2052 }
2053
2054 rbio->operation = BTRFS_RBIO_READ_REBUILD;
2055 rbio_add_bio(rbio, bio);
2056
2057 set_rbio_range_error(rbio, bio);
2058
2059 /*
2060 * Loop retry:
2061 * for 'mirror == 2', reconstruct from all other stripes.
2062 * for 'mirror_num > 2', select a stripe to fail on every retry.
2063 */
2064 if (mirror_num > 2)
2065 set_rbio_raid6_extra_error(rbio, mirror_num);
2066
2067 start_async_work(rbio, recover_rbio_work);
2068}
2069
2070static void fill_data_csums(struct btrfs_raid_bio *rbio)
2071{
2072 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
2073 struct btrfs_root *csum_root = btrfs_csum_root(fs_info,
2074 rbio->bioc->full_stripe_logical);
2075 const u64 start = rbio->bioc->full_stripe_logical;
2076 const u32 len = (rbio->nr_data * rbio->stripe_nsectors) <<
2077 fs_info->sectorsize_bits;
2078 int ret;
2079
2080 /* The rbio should not have its csum buffer initialized. */
2081 ASSERT(!rbio->csum_buf && !rbio->csum_bitmap);
2082
2083 /*
2084 * Skip the csum search if:
2085 *
2086 * - The rbio doesn't belong to data block groups
2087 * Then we are doing IO for tree blocks, no need to search csums.
2088 *
2089 * - The rbio belongs to mixed block groups
2090 * This is to avoid deadlock, as we're already holding the full
2091 * stripe lock, if we trigger a metadata read, and it needs to do
2092 * raid56 recovery, we will deadlock.
2093 */
2094 if (!(rbio->bioc->map_type & BTRFS_BLOCK_GROUP_DATA) ||
2095 rbio->bioc->map_type & BTRFS_BLOCK_GROUP_METADATA)
2096 return;
2097
2098 rbio->csum_buf = kzalloc(rbio->nr_data * rbio->stripe_nsectors *
2099 fs_info->csum_size, GFP_NOFS);
2100 rbio->csum_bitmap = bitmap_zalloc(rbio->nr_data * rbio->stripe_nsectors,
2101 GFP_NOFS);
2102 if (!rbio->csum_buf || !rbio->csum_bitmap) {
2103 ret = -ENOMEM;
2104 goto error;
2105 }
2106
2107 ret = btrfs_lookup_csums_bitmap(csum_root, NULL, start, start + len - 1,
2108 rbio->csum_buf, rbio->csum_bitmap);
2109 if (ret < 0)
2110 goto error;
2111 if (bitmap_empty(rbio->csum_bitmap, len >> fs_info->sectorsize_bits))
2112 goto no_csum;
2113 return;
2114
2115error:
2116 /*
2117 * We failed to allocate memory or grab the csum, but it's not fatal,
2118 * we can still continue. But better to warn users that RMW is no
2119 * longer safe for this particular sub-stripe write.
2120 */
2121 btrfs_warn_rl(fs_info,
2122"sub-stripe write for full stripe %llu is not safe, failed to get csum: %d",
2123 rbio->bioc->full_stripe_logical, ret);
2124no_csum:
2125 kfree(rbio->csum_buf);
2126 bitmap_free(rbio->csum_bitmap);
2127 rbio->csum_buf = NULL;
2128 rbio->csum_bitmap = NULL;
2129}
2130
2131static int rmw_read_wait_recover(struct btrfs_raid_bio *rbio)
2132{
2133 struct bio_list bio_list = BIO_EMPTY_LIST;
2134 int total_sector_nr;
2135 int ret = 0;
2136
2137 /*
2138 * Fill the data csums we need for data verification. We need to fill
2139 * the csum_bitmap/csum_buf first, as our endio function will try to
2140 * verify the data sectors.
2141 */
2142 fill_data_csums(rbio);
2143
2144 /*
2145 * Build a list of bios to read all sectors (including data and P/Q).
2146 *
2147 * This behavior is to compensate the later csum verification and recovery.
2148 */
2149 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2150 total_sector_nr++) {
2151 struct sector_ptr *sector;
2152 int stripe = total_sector_nr / rbio->stripe_nsectors;
2153 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2154
2155 sector = rbio_stripe_sector(rbio, stripe, sectornr);
2156 ret = rbio_add_io_sector(rbio, &bio_list, sector,
2157 stripe, sectornr, REQ_OP_READ);
2158 if (ret) {
2159 bio_list_put(&bio_list);
2160 return ret;
2161 }
2162 }
2163
2164 /*
2165 * We may or may not have any corrupted sectors (including missing dev
2166 * and csum mismatch), just let recover_sectors() to handle them all.
2167 */
2168 submit_read_wait_bio_list(rbio, &bio_list);
2169 return recover_sectors(rbio);
2170}
2171
2172static void raid_wait_write_end_io(struct bio *bio)
2173{
2174 struct btrfs_raid_bio *rbio = bio->bi_private;
2175 blk_status_t err = bio->bi_status;
2176
2177 if (err)
2178 rbio_update_error_bitmap(rbio, bio);
2179 bio_put(bio);
2180 if (atomic_dec_and_test(&rbio->stripes_pending))
2181 wake_up(&rbio->io_wait);
2182}
2183
2184static void submit_write_bios(struct btrfs_raid_bio *rbio,
2185 struct bio_list *bio_list)
2186{
2187 struct bio *bio;
2188
2189 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
2190 while ((bio = bio_list_pop(bio_list))) {
2191 bio->bi_end_io = raid_wait_write_end_io;
2192
2193 if (trace_raid56_write_enabled()) {
2194 struct raid56_bio_trace_info trace_info = { 0 };
2195
2196 bio_get_trace_info(rbio, bio, &trace_info);
2197 trace_raid56_write(rbio, bio, &trace_info);
2198 }
2199 submit_bio(bio);
2200 }
2201}
2202
2203/*
2204 * To determine if we need to read any sector from the disk.
2205 * Should only be utilized in RMW path, to skip cached rbio.
2206 */
2207static bool need_read_stripe_sectors(struct btrfs_raid_bio *rbio)
2208{
2209 int i;
2210
2211 for (i = 0; i < rbio->nr_data * rbio->stripe_nsectors; i++) {
2212 struct sector_ptr *sector = &rbio->stripe_sectors[i];
2213
2214 /*
2215 * We have a sector which doesn't have page nor uptodate,
2216 * thus this rbio can not be cached one, as cached one must
2217 * have all its data sectors present and uptodate.
2218 */
2219 if (!sector->page || !sector->uptodate)
2220 return true;
2221 }
2222 return false;
2223}
2224
2225static void rmw_rbio(struct btrfs_raid_bio *rbio)
2226{
2227 struct bio_list bio_list;
2228 int sectornr;
2229 int ret = 0;
2230
2231 /*
2232 * Allocate the pages for parity first, as P/Q pages will always be
2233 * needed for both full-stripe and sub-stripe writes.
2234 */
2235 ret = alloc_rbio_parity_pages(rbio);
2236 if (ret < 0)
2237 goto out;
2238
2239 /*
2240 * Either full stripe write, or we have every data sector already
2241 * cached, can go to write path immediately.
2242 */
2243 if (!rbio_is_full(rbio) && need_read_stripe_sectors(rbio)) {
2244 /*
2245 * Now we're doing sub-stripe write, also need all data stripes
2246 * to do the full RMW.
2247 */
2248 ret = alloc_rbio_data_pages(rbio);
2249 if (ret < 0)
2250 goto out;
2251
2252 index_rbio_pages(rbio);
2253
2254 ret = rmw_read_wait_recover(rbio);
2255 if (ret < 0)
2256 goto out;
2257 }
2258
2259 /*
2260 * At this stage we're not allowed to add any new bios to the
2261 * bio list any more, anyone else that wants to change this stripe
2262 * needs to do their own rmw.
2263 */
2264 spin_lock(&rbio->bio_list_lock);
2265 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
2266 spin_unlock(&rbio->bio_list_lock);
2267
2268 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2269
2270 index_rbio_pages(rbio);
2271
2272 /*
2273 * We don't cache full rbios because we're assuming
2274 * the higher layers are unlikely to use this area of
2275 * the disk again soon. If they do use it again,
2276 * hopefully they will send another full bio.
2277 */
2278 if (!rbio_is_full(rbio))
2279 cache_rbio_pages(rbio);
2280 else
2281 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2282
2283 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
2284 generate_pq_vertical(rbio, sectornr);
2285
2286 bio_list_init(&bio_list);
2287 ret = rmw_assemble_write_bios(rbio, &bio_list);
2288 if (ret < 0)
2289 goto out;
2290
2291 /* We should have at least one bio assembled. */
2292 ASSERT(bio_list_size(&bio_list));
2293 submit_write_bios(rbio, &bio_list);
2294 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2295
2296 /* We may have more errors than our tolerance during the read. */
2297 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
2298 int found_errors;
2299
2300 found_errors = get_rbio_veritical_errors(rbio, sectornr, NULL, NULL);
2301 if (found_errors > rbio->bioc->max_errors) {
2302 ret = -EIO;
2303 break;
2304 }
2305 }
2306out:
2307 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2308}
2309
2310static void rmw_rbio_work(struct work_struct *work)
2311{
2312 struct btrfs_raid_bio *rbio;
2313
2314 rbio = container_of(work, struct btrfs_raid_bio, work);
2315 if (lock_stripe_add(rbio) == 0)
2316 rmw_rbio(rbio);
2317}
2318
2319static void rmw_rbio_work_locked(struct work_struct *work)
2320{
2321 rmw_rbio(container_of(work, struct btrfs_raid_bio, work));
2322}
2323
2324/*
2325 * The following code is used to scrub/replace the parity stripe
2326 *
2327 * Caller must have already increased bio_counter for getting @bioc.
2328 *
2329 * Note: We need make sure all the pages that add into the scrub/replace
2330 * raid bio are correct and not be changed during the scrub/replace. That
2331 * is those pages just hold metadata or file data with checksum.
2332 */
2333
2334struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
2335 struct btrfs_io_context *bioc,
2336 struct btrfs_device *scrub_dev,
2337 unsigned long *dbitmap, int stripe_nsectors)
2338{
2339 struct btrfs_fs_info *fs_info = bioc->fs_info;
2340 struct btrfs_raid_bio *rbio;
2341 int i;
2342
2343 rbio = alloc_rbio(fs_info, bioc);
2344 if (IS_ERR(rbio))
2345 return NULL;
2346 bio_list_add(&rbio->bio_list, bio);
2347 /*
2348 * This is a special bio which is used to hold the completion handler
2349 * and make the scrub rbio is similar to the other types
2350 */
2351 ASSERT(!bio->bi_iter.bi_size);
2352 rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
2353
2354 /*
2355 * After mapping bioc with BTRFS_MAP_WRITE, parities have been sorted
2356 * to the end position, so this search can start from the first parity
2357 * stripe.
2358 */
2359 for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
2360 if (bioc->stripes[i].dev == scrub_dev) {
2361 rbio->scrubp = i;
2362 break;
2363 }
2364 }
2365 ASSERT(i < rbio->real_stripes);
2366
2367 bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors);
2368 return rbio;
2369}
2370
2371/*
2372 * We just scrub the parity that we have correct data on the same horizontal,
2373 * so we needn't allocate all pages for all the stripes.
2374 */
2375static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
2376{
2377 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2378 int total_sector_nr;
2379
2380 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2381 total_sector_nr++) {
2382 struct page *page;
2383 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2384 int index = (total_sector_nr * sectorsize) >> PAGE_SHIFT;
2385
2386 if (!test_bit(sectornr, &rbio->dbitmap))
2387 continue;
2388 if (rbio->stripe_pages[index])
2389 continue;
2390 page = alloc_page(GFP_NOFS);
2391 if (!page)
2392 return -ENOMEM;
2393 rbio->stripe_pages[index] = page;
2394 }
2395 index_stripe_sectors(rbio);
2396 return 0;
2397}
2398
2399static int finish_parity_scrub(struct btrfs_raid_bio *rbio)
2400{
2401 struct btrfs_io_context *bioc = rbio->bioc;
2402 const u32 sectorsize = bioc->fs_info->sectorsize;
2403 void **pointers = rbio->finish_pointers;
2404 unsigned long *pbitmap = &rbio->finish_pbitmap;
2405 int nr_data = rbio->nr_data;
2406 int stripe;
2407 int sectornr;
2408 bool has_qstripe;
2409 struct sector_ptr p_sector = { 0 };
2410 struct sector_ptr q_sector = { 0 };
2411 struct bio_list bio_list;
2412 int is_replace = 0;
2413 int ret;
2414
2415 bio_list_init(&bio_list);
2416
2417 if (rbio->real_stripes - rbio->nr_data == 1)
2418 has_qstripe = false;
2419 else if (rbio->real_stripes - rbio->nr_data == 2)
2420 has_qstripe = true;
2421 else
2422 BUG();
2423
2424 /*
2425 * Replace is running and our P/Q stripe is being replaced, then we
2426 * need to duplicate the final write to replace target.
2427 */
2428 if (bioc->replace_nr_stripes && bioc->replace_stripe_src == rbio->scrubp) {
2429 is_replace = 1;
2430 bitmap_copy(pbitmap, &rbio->dbitmap, rbio->stripe_nsectors);
2431 }
2432
2433 /*
2434 * Because the higher layers(scrubber) are unlikely to
2435 * use this area of the disk again soon, so don't cache
2436 * it.
2437 */
2438 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2439
2440 p_sector.page = alloc_page(GFP_NOFS);
2441 if (!p_sector.page)
2442 return -ENOMEM;
2443 p_sector.pgoff = 0;
2444 p_sector.uptodate = 1;
2445
2446 if (has_qstripe) {
2447 /* RAID6, allocate and map temp space for the Q stripe */
2448 q_sector.page = alloc_page(GFP_NOFS);
2449 if (!q_sector.page) {
2450 __free_page(p_sector.page);
2451 p_sector.page = NULL;
2452 return -ENOMEM;
2453 }
2454 q_sector.pgoff = 0;
2455 q_sector.uptodate = 1;
2456 pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page);
2457 }
2458
2459 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2460
2461 /* Map the parity stripe just once */
2462 pointers[nr_data] = kmap_local_page(p_sector.page);
2463
2464 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2465 struct sector_ptr *sector;
2466 void *parity;
2467
2468 /* first collect one page from each data stripe */
2469 for (stripe = 0; stripe < nr_data; stripe++) {
2470 sector = sector_in_rbio(rbio, stripe, sectornr, 0);
2471 pointers[stripe] = kmap_local_page(sector->page) +
2472 sector->pgoff;
2473 }
2474
2475 if (has_qstripe) {
2476 /* RAID6, call the library function to fill in our P/Q */
2477 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
2478 pointers);
2479 } else {
2480 /* raid5 */
2481 memcpy(pointers[nr_data], pointers[0], sectorsize);
2482 run_xor(pointers + 1, nr_data - 1, sectorsize);
2483 }
2484
2485 /* Check scrubbing parity and repair it */
2486 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2487 parity = kmap_local_page(sector->page) + sector->pgoff;
2488 if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0)
2489 memcpy(parity, pointers[rbio->scrubp], sectorsize);
2490 else
2491 /* Parity is right, needn't writeback */
2492 bitmap_clear(&rbio->dbitmap, sectornr, 1);
2493 kunmap_local(parity);
2494
2495 for (stripe = nr_data - 1; stripe >= 0; stripe--)
2496 kunmap_local(pointers[stripe]);
2497 }
2498
2499 kunmap_local(pointers[nr_data]);
2500 __free_page(p_sector.page);
2501 p_sector.page = NULL;
2502 if (q_sector.page) {
2503 kunmap_local(pointers[rbio->real_stripes - 1]);
2504 __free_page(q_sector.page);
2505 q_sector.page = NULL;
2506 }
2507
2508 /*
2509 * time to start writing. Make bios for everything from the
2510 * higher layers (the bio_list in our rbio) and our p/q. Ignore
2511 * everything else.
2512 */
2513 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2514 struct sector_ptr *sector;
2515
2516 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2517 ret = rbio_add_io_sector(rbio, &bio_list, sector, rbio->scrubp,
2518 sectornr, REQ_OP_WRITE);
2519 if (ret)
2520 goto cleanup;
2521 }
2522
2523 if (!is_replace)
2524 goto submit_write;
2525
2526 /*
2527 * Replace is running and our parity stripe needs to be duplicated to
2528 * the target device. Check we have a valid source stripe number.
2529 */
2530 ASSERT(rbio->bioc->replace_stripe_src >= 0);
2531 for_each_set_bit(sectornr, pbitmap, rbio->stripe_nsectors) {
2532 struct sector_ptr *sector;
2533
2534 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2535 ret = rbio_add_io_sector(rbio, &bio_list, sector,
2536 rbio->real_stripes,
2537 sectornr, REQ_OP_WRITE);
2538 if (ret)
2539 goto cleanup;
2540 }
2541
2542submit_write:
2543 submit_write_bios(rbio, &bio_list);
2544 return 0;
2545
2546cleanup:
2547 bio_list_put(&bio_list);
2548 return ret;
2549}
2550
2551static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
2552{
2553 if (stripe >= 0 && stripe < rbio->nr_data)
2554 return 1;
2555 return 0;
2556}
2557
2558static int recover_scrub_rbio(struct btrfs_raid_bio *rbio)
2559{
2560 void **pointers = NULL;
2561 void **unmap_array = NULL;
2562 int sector_nr;
2563 int ret = 0;
2564
2565 /*
2566 * @pointers array stores the pointer for each sector.
2567 *
2568 * @unmap_array stores copy of pointers that does not get reordered
2569 * during reconstruction so that kunmap_local works.
2570 */
2571 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2572 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2573 if (!pointers || !unmap_array) {
2574 ret = -ENOMEM;
2575 goto out;
2576 }
2577
2578 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2579 int dfail = 0, failp = -1;
2580 int faila;
2581 int failb;
2582 int found_errors;
2583
2584 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2585 &faila, &failb);
2586 if (found_errors > rbio->bioc->max_errors) {
2587 ret = -EIO;
2588 goto out;
2589 }
2590 if (found_errors == 0)
2591 continue;
2592
2593 /* We should have at least one error here. */
2594 ASSERT(faila >= 0 || failb >= 0);
2595
2596 if (is_data_stripe(rbio, faila))
2597 dfail++;
2598 else if (is_parity_stripe(faila))
2599 failp = faila;
2600
2601 if (is_data_stripe(rbio, failb))
2602 dfail++;
2603 else if (is_parity_stripe(failb))
2604 failp = failb;
2605 /*
2606 * Because we can not use a scrubbing parity to repair the
2607 * data, so the capability of the repair is declined. (In the
2608 * case of RAID5, we can not repair anything.)
2609 */
2610 if (dfail > rbio->bioc->max_errors - 1) {
2611 ret = -EIO;
2612 goto out;
2613 }
2614 /*
2615 * If all data is good, only parity is correctly, just repair
2616 * the parity, no need to recover data stripes.
2617 */
2618 if (dfail == 0)
2619 continue;
2620
2621 /*
2622 * Here means we got one corrupted data stripe and one
2623 * corrupted parity on RAID6, if the corrupted parity is
2624 * scrubbing parity, luckily, use the other one to repair the
2625 * data, or we can not repair the data stripe.
2626 */
2627 if (failp != rbio->scrubp) {
2628 ret = -EIO;
2629 goto out;
2630 }
2631
2632 ret = recover_vertical(rbio, sector_nr, pointers, unmap_array);
2633 if (ret < 0)
2634 goto out;
2635 }
2636out:
2637 kfree(pointers);
2638 kfree(unmap_array);
2639 return ret;
2640}
2641
2642static int scrub_assemble_read_bios(struct btrfs_raid_bio *rbio)
2643{
2644 struct bio_list bio_list = BIO_EMPTY_LIST;
2645 int total_sector_nr;
2646 int ret = 0;
2647
2648 /* Build a list of bios to read all the missing parts. */
2649 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2650 total_sector_nr++) {
2651 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2652 int stripe = total_sector_nr / rbio->stripe_nsectors;
2653 struct sector_ptr *sector;
2654
2655 /* No data in the vertical stripe, no need to read. */
2656 if (!test_bit(sectornr, &rbio->dbitmap))
2657 continue;
2658
2659 /*
2660 * We want to find all the sectors missing from the rbio and
2661 * read them from the disk. If sector_in_rbio() finds a sector
2662 * in the bio list we don't need to read it off the stripe.
2663 */
2664 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
2665 if (sector)
2666 continue;
2667
2668 sector = rbio_stripe_sector(rbio, stripe, sectornr);
2669 /*
2670 * The bio cache may have handed us an uptodate sector. If so,
2671 * use it.
2672 */
2673 if (sector->uptodate)
2674 continue;
2675
2676 ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
2677 sectornr, REQ_OP_READ);
2678 if (ret) {
2679 bio_list_put(&bio_list);
2680 return ret;
2681 }
2682 }
2683
2684 submit_read_wait_bio_list(rbio, &bio_list);
2685 return 0;
2686}
2687
2688static void scrub_rbio(struct btrfs_raid_bio *rbio)
2689{
2690 int sector_nr;
2691 int ret;
2692
2693 ret = alloc_rbio_essential_pages(rbio);
2694 if (ret)
2695 goto out;
2696
2697 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2698
2699 ret = scrub_assemble_read_bios(rbio);
2700 if (ret < 0)
2701 goto out;
2702
2703 /* We may have some failures, recover the failed sectors first. */
2704 ret = recover_scrub_rbio(rbio);
2705 if (ret < 0)
2706 goto out;
2707
2708 /*
2709 * We have every sector properly prepared. Can finish the scrub
2710 * and writeback the good content.
2711 */
2712 ret = finish_parity_scrub(rbio);
2713 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2714 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2715 int found_errors;
2716
2717 found_errors = get_rbio_veritical_errors(rbio, sector_nr, NULL, NULL);
2718 if (found_errors > rbio->bioc->max_errors) {
2719 ret = -EIO;
2720 break;
2721 }
2722 }
2723out:
2724 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2725}
2726
2727static void scrub_rbio_work_locked(struct work_struct *work)
2728{
2729 scrub_rbio(container_of(work, struct btrfs_raid_bio, work));
2730}
2731
2732void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
2733{
2734 if (!lock_stripe_add(rbio))
2735 start_async_work(rbio, scrub_rbio_work_locked);
2736}
2737
2738/*
2739 * This is for scrub call sites where we already have correct data contents.
2740 * This allows us to avoid reading data stripes again.
2741 *
2742 * Unfortunately here we have to do page copy, other than reusing the pages.
2743 * This is due to the fact rbio has its own page management for its cache.
2744 */
2745void raid56_parity_cache_data_pages(struct btrfs_raid_bio *rbio,
2746 struct page **data_pages, u64 data_logical)
2747{
2748 const u64 offset_in_full_stripe = data_logical -
2749 rbio->bioc->full_stripe_logical;
2750 const int page_index = offset_in_full_stripe >> PAGE_SHIFT;
2751 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2752 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
2753 int ret;
2754
2755 /*
2756 * If we hit ENOMEM temporarily, but later at
2757 * raid56_parity_submit_scrub_rbio() time it succeeded, we just do
2758 * the extra read, not a big deal.
2759 *
2760 * If we hit ENOMEM later at raid56_parity_submit_scrub_rbio() time,
2761 * the bio would got proper error number set.
2762 */
2763 ret = alloc_rbio_data_pages(rbio);
2764 if (ret < 0)
2765 return;
2766
2767 /* data_logical must be at stripe boundary and inside the full stripe. */
2768 ASSERT(IS_ALIGNED(offset_in_full_stripe, BTRFS_STRIPE_LEN));
2769 ASSERT(offset_in_full_stripe < (rbio->nr_data << BTRFS_STRIPE_LEN_SHIFT));
2770
2771 for (int page_nr = 0; page_nr < (BTRFS_STRIPE_LEN >> PAGE_SHIFT); page_nr++) {
2772 struct page *dst = rbio->stripe_pages[page_nr + page_index];
2773 struct page *src = data_pages[page_nr];
2774
2775 memcpy_page(dst, 0, src, 0, PAGE_SIZE);
2776 for (int sector_nr = sectors_per_page * page_index;
2777 sector_nr < sectors_per_page * (page_index + 1);
2778 sector_nr++)
2779 rbio->stripe_sectors[sector_nr].uptodate = true;
2780 }
2781}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2012 Fusion-io All rights reserved.
4 * Copyright (C) 2012 Intel Corp. All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/bio.h>
9#include <linux/slab.h>
10#include <linux/blkdev.h>
11#include <linux/raid/pq.h>
12#include <linux/hash.h>
13#include <linux/list_sort.h>
14#include <linux/raid/xor.h>
15#include <linux/mm.h>
16#include "messages.h"
17#include "misc.h"
18#include "ctree.h"
19#include "disk-io.h"
20#include "volumes.h"
21#include "raid56.h"
22#include "async-thread.h"
23#include "file-item.h"
24#include "btrfs_inode.h"
25
26/* set when additional merges to this rbio are not allowed */
27#define RBIO_RMW_LOCKED_BIT 1
28
29/*
30 * set when this rbio is sitting in the hash, but it is just a cache
31 * of past RMW
32 */
33#define RBIO_CACHE_BIT 2
34
35/*
36 * set when it is safe to trust the stripe_pages for caching
37 */
38#define RBIO_CACHE_READY_BIT 3
39
40#define RBIO_CACHE_SIZE 1024
41
42#define BTRFS_STRIPE_HASH_TABLE_BITS 11
43
44/* Used by the raid56 code to lock stripes for read/modify/write */
45struct btrfs_stripe_hash {
46 struct list_head hash_list;
47 spinlock_t lock;
48};
49
50/* Used by the raid56 code to lock stripes for read/modify/write */
51struct btrfs_stripe_hash_table {
52 struct list_head stripe_cache;
53 spinlock_t cache_lock;
54 int cache_size;
55 struct btrfs_stripe_hash table[];
56};
57
58/*
59 * A bvec like structure to present a sector inside a page.
60 *
61 * Unlike bvec we don't need bvlen, as it's fixed to sectorsize.
62 */
63struct sector_ptr {
64 struct page *page;
65 unsigned int pgoff:24;
66 unsigned int uptodate:8;
67};
68
69static void rmw_rbio_work(struct work_struct *work);
70static void rmw_rbio_work_locked(struct work_struct *work);
71static void index_rbio_pages(struct btrfs_raid_bio *rbio);
72static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
73
74static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check);
75static void scrub_rbio_work_locked(struct work_struct *work);
76
77static void free_raid_bio_pointers(struct btrfs_raid_bio *rbio)
78{
79 bitmap_free(rbio->error_bitmap);
80 kfree(rbio->stripe_pages);
81 kfree(rbio->bio_sectors);
82 kfree(rbio->stripe_sectors);
83 kfree(rbio->finish_pointers);
84}
85
86static void free_raid_bio(struct btrfs_raid_bio *rbio)
87{
88 int i;
89
90 if (!refcount_dec_and_test(&rbio->refs))
91 return;
92
93 WARN_ON(!list_empty(&rbio->stripe_cache));
94 WARN_ON(!list_empty(&rbio->hash_list));
95 WARN_ON(!bio_list_empty(&rbio->bio_list));
96
97 for (i = 0; i < rbio->nr_pages; i++) {
98 if (rbio->stripe_pages[i]) {
99 __free_page(rbio->stripe_pages[i]);
100 rbio->stripe_pages[i] = NULL;
101 }
102 }
103
104 btrfs_put_bioc(rbio->bioc);
105 free_raid_bio_pointers(rbio);
106 kfree(rbio);
107}
108
109static void start_async_work(struct btrfs_raid_bio *rbio, work_func_t work_func)
110{
111 INIT_WORK(&rbio->work, work_func);
112 queue_work(rbio->bioc->fs_info->rmw_workers, &rbio->work);
113}
114
115/*
116 * the stripe hash table is used for locking, and to collect
117 * bios in hopes of making a full stripe
118 */
119int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
120{
121 struct btrfs_stripe_hash_table *table;
122 struct btrfs_stripe_hash_table *x;
123 struct btrfs_stripe_hash *cur;
124 struct btrfs_stripe_hash *h;
125 int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
126 int i;
127
128 if (info->stripe_hash_table)
129 return 0;
130
131 /*
132 * The table is large, starting with order 4 and can go as high as
133 * order 7 in case lock debugging is turned on.
134 *
135 * Try harder to allocate and fallback to vmalloc to lower the chance
136 * of a failing mount.
137 */
138 table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL);
139 if (!table)
140 return -ENOMEM;
141
142 spin_lock_init(&table->cache_lock);
143 INIT_LIST_HEAD(&table->stripe_cache);
144
145 h = table->table;
146
147 for (i = 0; i < num_entries; i++) {
148 cur = h + i;
149 INIT_LIST_HEAD(&cur->hash_list);
150 spin_lock_init(&cur->lock);
151 }
152
153 x = cmpxchg(&info->stripe_hash_table, NULL, table);
154 kvfree(x);
155 return 0;
156}
157
158/*
159 * caching an rbio means to copy anything from the
160 * bio_sectors array into the stripe_pages array. We
161 * use the page uptodate bit in the stripe cache array
162 * to indicate if it has valid data
163 *
164 * once the caching is done, we set the cache ready
165 * bit.
166 */
167static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
168{
169 int i;
170 int ret;
171
172 ret = alloc_rbio_pages(rbio);
173 if (ret)
174 return;
175
176 for (i = 0; i < rbio->nr_sectors; i++) {
177 /* Some range not covered by bio (partial write), skip it */
178 if (!rbio->bio_sectors[i].page) {
179 /*
180 * Even if the sector is not covered by bio, if it is
181 * a data sector it should still be uptodate as it is
182 * read from disk.
183 */
184 if (i < rbio->nr_data * rbio->stripe_nsectors)
185 ASSERT(rbio->stripe_sectors[i].uptodate);
186 continue;
187 }
188
189 ASSERT(rbio->stripe_sectors[i].page);
190 memcpy_page(rbio->stripe_sectors[i].page,
191 rbio->stripe_sectors[i].pgoff,
192 rbio->bio_sectors[i].page,
193 rbio->bio_sectors[i].pgoff,
194 rbio->bioc->fs_info->sectorsize);
195 rbio->stripe_sectors[i].uptodate = 1;
196 }
197 set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
198}
199
200/*
201 * we hash on the first logical address of the stripe
202 */
203static int rbio_bucket(struct btrfs_raid_bio *rbio)
204{
205 u64 num = rbio->bioc->raid_map[0];
206
207 /*
208 * we shift down quite a bit. We're using byte
209 * addressing, and most of the lower bits are zeros.
210 * This tends to upset hash_64, and it consistently
211 * returns just one or two different values.
212 *
213 * shifting off the lower bits fixes things.
214 */
215 return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
216}
217
218static bool full_page_sectors_uptodate(struct btrfs_raid_bio *rbio,
219 unsigned int page_nr)
220{
221 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
222 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
223 int i;
224
225 ASSERT(page_nr < rbio->nr_pages);
226
227 for (i = sectors_per_page * page_nr;
228 i < sectors_per_page * page_nr + sectors_per_page;
229 i++) {
230 if (!rbio->stripe_sectors[i].uptodate)
231 return false;
232 }
233 return true;
234}
235
236/*
237 * Update the stripe_sectors[] array to use correct page and pgoff
238 *
239 * Should be called every time any page pointer in stripes_pages[] got modified.
240 */
241static void index_stripe_sectors(struct btrfs_raid_bio *rbio)
242{
243 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
244 u32 offset;
245 int i;
246
247 for (i = 0, offset = 0; i < rbio->nr_sectors; i++, offset += sectorsize) {
248 int page_index = offset >> PAGE_SHIFT;
249
250 ASSERT(page_index < rbio->nr_pages);
251 rbio->stripe_sectors[i].page = rbio->stripe_pages[page_index];
252 rbio->stripe_sectors[i].pgoff = offset_in_page(offset);
253 }
254}
255
256static void steal_rbio_page(struct btrfs_raid_bio *src,
257 struct btrfs_raid_bio *dest, int page_nr)
258{
259 const u32 sectorsize = src->bioc->fs_info->sectorsize;
260 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
261 int i;
262
263 if (dest->stripe_pages[page_nr])
264 __free_page(dest->stripe_pages[page_nr]);
265 dest->stripe_pages[page_nr] = src->stripe_pages[page_nr];
266 src->stripe_pages[page_nr] = NULL;
267
268 /* Also update the sector->uptodate bits. */
269 for (i = sectors_per_page * page_nr;
270 i < sectors_per_page * page_nr + sectors_per_page; i++)
271 dest->stripe_sectors[i].uptodate = true;
272}
273
274static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr)
275{
276 const int sector_nr = (page_nr << PAGE_SHIFT) >>
277 rbio->bioc->fs_info->sectorsize_bits;
278
279 /*
280 * We have ensured PAGE_SIZE is aligned with sectorsize, thus
281 * we won't have a page which is half data half parity.
282 *
283 * Thus if the first sector of the page belongs to data stripes, then
284 * the full page belongs to data stripes.
285 */
286 return (sector_nr < rbio->nr_data * rbio->stripe_nsectors);
287}
288
289/*
290 * Stealing an rbio means taking all the uptodate pages from the stripe array
291 * in the source rbio and putting them into the destination rbio.
292 *
293 * This will also update the involved stripe_sectors[] which are referring to
294 * the old pages.
295 */
296static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
297{
298 int i;
299
300 if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
301 return;
302
303 for (i = 0; i < dest->nr_pages; i++) {
304 struct page *p = src->stripe_pages[i];
305
306 /*
307 * We don't need to steal P/Q pages as they will always be
308 * regenerated for RMW or full write anyway.
309 */
310 if (!is_data_stripe_page(src, i))
311 continue;
312
313 /*
314 * If @src already has RBIO_CACHE_READY_BIT, it should have
315 * all data stripe pages present and uptodate.
316 */
317 ASSERT(p);
318 ASSERT(full_page_sectors_uptodate(src, i));
319 steal_rbio_page(src, dest, i);
320 }
321 index_stripe_sectors(dest);
322 index_stripe_sectors(src);
323}
324
325/*
326 * merging means we take the bio_list from the victim and
327 * splice it into the destination. The victim should
328 * be discarded afterwards.
329 *
330 * must be called with dest->rbio_list_lock held
331 */
332static void merge_rbio(struct btrfs_raid_bio *dest,
333 struct btrfs_raid_bio *victim)
334{
335 bio_list_merge(&dest->bio_list, &victim->bio_list);
336 dest->bio_list_bytes += victim->bio_list_bytes;
337 /* Also inherit the bitmaps from @victim. */
338 bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap,
339 dest->stripe_nsectors);
340 bio_list_init(&victim->bio_list);
341}
342
343/*
344 * used to prune items that are in the cache. The caller
345 * must hold the hash table lock.
346 */
347static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
348{
349 int bucket = rbio_bucket(rbio);
350 struct btrfs_stripe_hash_table *table;
351 struct btrfs_stripe_hash *h;
352 int freeit = 0;
353
354 /*
355 * check the bit again under the hash table lock.
356 */
357 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
358 return;
359
360 table = rbio->bioc->fs_info->stripe_hash_table;
361 h = table->table + bucket;
362
363 /* hold the lock for the bucket because we may be
364 * removing it from the hash table
365 */
366 spin_lock(&h->lock);
367
368 /*
369 * hold the lock for the bio list because we need
370 * to make sure the bio list is empty
371 */
372 spin_lock(&rbio->bio_list_lock);
373
374 if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
375 list_del_init(&rbio->stripe_cache);
376 table->cache_size -= 1;
377 freeit = 1;
378
379 /* if the bio list isn't empty, this rbio is
380 * still involved in an IO. We take it out
381 * of the cache list, and drop the ref that
382 * was held for the list.
383 *
384 * If the bio_list was empty, we also remove
385 * the rbio from the hash_table, and drop
386 * the corresponding ref
387 */
388 if (bio_list_empty(&rbio->bio_list)) {
389 if (!list_empty(&rbio->hash_list)) {
390 list_del_init(&rbio->hash_list);
391 refcount_dec(&rbio->refs);
392 BUG_ON(!list_empty(&rbio->plug_list));
393 }
394 }
395 }
396
397 spin_unlock(&rbio->bio_list_lock);
398 spin_unlock(&h->lock);
399
400 if (freeit)
401 free_raid_bio(rbio);
402}
403
404/*
405 * prune a given rbio from the cache
406 */
407static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
408{
409 struct btrfs_stripe_hash_table *table;
410 unsigned long flags;
411
412 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
413 return;
414
415 table = rbio->bioc->fs_info->stripe_hash_table;
416
417 spin_lock_irqsave(&table->cache_lock, flags);
418 __remove_rbio_from_cache(rbio);
419 spin_unlock_irqrestore(&table->cache_lock, flags);
420}
421
422/*
423 * remove everything in the cache
424 */
425static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
426{
427 struct btrfs_stripe_hash_table *table;
428 unsigned long flags;
429 struct btrfs_raid_bio *rbio;
430
431 table = info->stripe_hash_table;
432
433 spin_lock_irqsave(&table->cache_lock, flags);
434 while (!list_empty(&table->stripe_cache)) {
435 rbio = list_entry(table->stripe_cache.next,
436 struct btrfs_raid_bio,
437 stripe_cache);
438 __remove_rbio_from_cache(rbio);
439 }
440 spin_unlock_irqrestore(&table->cache_lock, flags);
441}
442
443/*
444 * remove all cached entries and free the hash table
445 * used by unmount
446 */
447void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
448{
449 if (!info->stripe_hash_table)
450 return;
451 btrfs_clear_rbio_cache(info);
452 kvfree(info->stripe_hash_table);
453 info->stripe_hash_table = NULL;
454}
455
456/*
457 * insert an rbio into the stripe cache. It
458 * must have already been prepared by calling
459 * cache_rbio_pages
460 *
461 * If this rbio was already cached, it gets
462 * moved to the front of the lru.
463 *
464 * If the size of the rbio cache is too big, we
465 * prune an item.
466 */
467static void cache_rbio(struct btrfs_raid_bio *rbio)
468{
469 struct btrfs_stripe_hash_table *table;
470 unsigned long flags;
471
472 if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
473 return;
474
475 table = rbio->bioc->fs_info->stripe_hash_table;
476
477 spin_lock_irqsave(&table->cache_lock, flags);
478 spin_lock(&rbio->bio_list_lock);
479
480 /* bump our ref if we were not in the list before */
481 if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
482 refcount_inc(&rbio->refs);
483
484 if (!list_empty(&rbio->stripe_cache)){
485 list_move(&rbio->stripe_cache, &table->stripe_cache);
486 } else {
487 list_add(&rbio->stripe_cache, &table->stripe_cache);
488 table->cache_size += 1;
489 }
490
491 spin_unlock(&rbio->bio_list_lock);
492
493 if (table->cache_size > RBIO_CACHE_SIZE) {
494 struct btrfs_raid_bio *found;
495
496 found = list_entry(table->stripe_cache.prev,
497 struct btrfs_raid_bio,
498 stripe_cache);
499
500 if (found != rbio)
501 __remove_rbio_from_cache(found);
502 }
503
504 spin_unlock_irqrestore(&table->cache_lock, flags);
505}
506
507/*
508 * helper function to run the xor_blocks api. It is only
509 * able to do MAX_XOR_BLOCKS at a time, so we need to
510 * loop through.
511 */
512static void run_xor(void **pages, int src_cnt, ssize_t len)
513{
514 int src_off = 0;
515 int xor_src_cnt = 0;
516 void *dest = pages[src_cnt];
517
518 while(src_cnt > 0) {
519 xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
520 xor_blocks(xor_src_cnt, len, dest, pages + src_off);
521
522 src_cnt -= xor_src_cnt;
523 src_off += xor_src_cnt;
524 }
525}
526
527/*
528 * Returns true if the bio list inside this rbio covers an entire stripe (no
529 * rmw required).
530 */
531static int rbio_is_full(struct btrfs_raid_bio *rbio)
532{
533 unsigned long flags;
534 unsigned long size = rbio->bio_list_bytes;
535 int ret = 1;
536
537 spin_lock_irqsave(&rbio->bio_list_lock, flags);
538 if (size != rbio->nr_data * BTRFS_STRIPE_LEN)
539 ret = 0;
540 BUG_ON(size > rbio->nr_data * BTRFS_STRIPE_LEN);
541 spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
542
543 return ret;
544}
545
546/*
547 * returns 1 if it is safe to merge two rbios together.
548 * The merging is safe if the two rbios correspond to
549 * the same stripe and if they are both going in the same
550 * direction (read vs write), and if neither one is
551 * locked for final IO
552 *
553 * The caller is responsible for locking such that
554 * rmw_locked is safe to test
555 */
556static int rbio_can_merge(struct btrfs_raid_bio *last,
557 struct btrfs_raid_bio *cur)
558{
559 if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
560 test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
561 return 0;
562
563 /*
564 * we can't merge with cached rbios, since the
565 * idea is that when we merge the destination
566 * rbio is going to run our IO for us. We can
567 * steal from cached rbios though, other functions
568 * handle that.
569 */
570 if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
571 test_bit(RBIO_CACHE_BIT, &cur->flags))
572 return 0;
573
574 if (last->bioc->raid_map[0] != cur->bioc->raid_map[0])
575 return 0;
576
577 /* we can't merge with different operations */
578 if (last->operation != cur->operation)
579 return 0;
580 /*
581 * We've need read the full stripe from the drive.
582 * check and repair the parity and write the new results.
583 *
584 * We're not allowed to add any new bios to the
585 * bio list here, anyone else that wants to
586 * change this stripe needs to do their own rmw.
587 */
588 if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
589 return 0;
590
591 if (last->operation == BTRFS_RBIO_REBUILD_MISSING ||
592 last->operation == BTRFS_RBIO_READ_REBUILD)
593 return 0;
594
595 return 1;
596}
597
598static unsigned int rbio_stripe_sector_index(const struct btrfs_raid_bio *rbio,
599 unsigned int stripe_nr,
600 unsigned int sector_nr)
601{
602 ASSERT(stripe_nr < rbio->real_stripes);
603 ASSERT(sector_nr < rbio->stripe_nsectors);
604
605 return stripe_nr * rbio->stripe_nsectors + sector_nr;
606}
607
608/* Return a sector from rbio->stripe_sectors, not from the bio list */
609static struct sector_ptr *rbio_stripe_sector(const struct btrfs_raid_bio *rbio,
610 unsigned int stripe_nr,
611 unsigned int sector_nr)
612{
613 return &rbio->stripe_sectors[rbio_stripe_sector_index(rbio, stripe_nr,
614 sector_nr)];
615}
616
617/* Grab a sector inside P stripe */
618static struct sector_ptr *rbio_pstripe_sector(const struct btrfs_raid_bio *rbio,
619 unsigned int sector_nr)
620{
621 return rbio_stripe_sector(rbio, rbio->nr_data, sector_nr);
622}
623
624/* Grab a sector inside Q stripe, return NULL if not RAID6 */
625static struct sector_ptr *rbio_qstripe_sector(const struct btrfs_raid_bio *rbio,
626 unsigned int sector_nr)
627{
628 if (rbio->nr_data + 1 == rbio->real_stripes)
629 return NULL;
630 return rbio_stripe_sector(rbio, rbio->nr_data + 1, sector_nr);
631}
632
633/*
634 * The first stripe in the table for a logical address
635 * has the lock. rbios are added in one of three ways:
636 *
637 * 1) Nobody has the stripe locked yet. The rbio is given
638 * the lock and 0 is returned. The caller must start the IO
639 * themselves.
640 *
641 * 2) Someone has the stripe locked, but we're able to merge
642 * with the lock owner. The rbio is freed and the IO will
643 * start automatically along with the existing rbio. 1 is returned.
644 *
645 * 3) Someone has the stripe locked, but we're not able to merge.
646 * The rbio is added to the lock owner's plug list, or merged into
647 * an rbio already on the plug list. When the lock owner unlocks,
648 * the next rbio on the list is run and the IO is started automatically.
649 * 1 is returned
650 *
651 * If we return 0, the caller still owns the rbio and must continue with
652 * IO submission. If we return 1, the caller must assume the rbio has
653 * already been freed.
654 */
655static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
656{
657 struct btrfs_stripe_hash *h;
658 struct btrfs_raid_bio *cur;
659 struct btrfs_raid_bio *pending;
660 unsigned long flags;
661 struct btrfs_raid_bio *freeit = NULL;
662 struct btrfs_raid_bio *cache_drop = NULL;
663 int ret = 0;
664
665 h = rbio->bioc->fs_info->stripe_hash_table->table + rbio_bucket(rbio);
666
667 spin_lock_irqsave(&h->lock, flags);
668 list_for_each_entry(cur, &h->hash_list, hash_list) {
669 if (cur->bioc->raid_map[0] != rbio->bioc->raid_map[0])
670 continue;
671
672 spin_lock(&cur->bio_list_lock);
673
674 /* Can we steal this cached rbio's pages? */
675 if (bio_list_empty(&cur->bio_list) &&
676 list_empty(&cur->plug_list) &&
677 test_bit(RBIO_CACHE_BIT, &cur->flags) &&
678 !test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) {
679 list_del_init(&cur->hash_list);
680 refcount_dec(&cur->refs);
681
682 steal_rbio(cur, rbio);
683 cache_drop = cur;
684 spin_unlock(&cur->bio_list_lock);
685
686 goto lockit;
687 }
688
689 /* Can we merge into the lock owner? */
690 if (rbio_can_merge(cur, rbio)) {
691 merge_rbio(cur, rbio);
692 spin_unlock(&cur->bio_list_lock);
693 freeit = rbio;
694 ret = 1;
695 goto out;
696 }
697
698
699 /*
700 * We couldn't merge with the running rbio, see if we can merge
701 * with the pending ones. We don't have to check for rmw_locked
702 * because there is no way they are inside finish_rmw right now
703 */
704 list_for_each_entry(pending, &cur->plug_list, plug_list) {
705 if (rbio_can_merge(pending, rbio)) {
706 merge_rbio(pending, rbio);
707 spin_unlock(&cur->bio_list_lock);
708 freeit = rbio;
709 ret = 1;
710 goto out;
711 }
712 }
713
714 /*
715 * No merging, put us on the tail of the plug list, our rbio
716 * will be started with the currently running rbio unlocks
717 */
718 list_add_tail(&rbio->plug_list, &cur->plug_list);
719 spin_unlock(&cur->bio_list_lock);
720 ret = 1;
721 goto out;
722 }
723lockit:
724 refcount_inc(&rbio->refs);
725 list_add(&rbio->hash_list, &h->hash_list);
726out:
727 spin_unlock_irqrestore(&h->lock, flags);
728 if (cache_drop)
729 remove_rbio_from_cache(cache_drop);
730 if (freeit)
731 free_raid_bio(freeit);
732 return ret;
733}
734
735static void recover_rbio_work_locked(struct work_struct *work);
736
737/*
738 * called as rmw or parity rebuild is completed. If the plug list has more
739 * rbios waiting for this stripe, the next one on the list will be started
740 */
741static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
742{
743 int bucket;
744 struct btrfs_stripe_hash *h;
745 unsigned long flags;
746 int keep_cache = 0;
747
748 bucket = rbio_bucket(rbio);
749 h = rbio->bioc->fs_info->stripe_hash_table->table + bucket;
750
751 if (list_empty(&rbio->plug_list))
752 cache_rbio(rbio);
753
754 spin_lock_irqsave(&h->lock, flags);
755 spin_lock(&rbio->bio_list_lock);
756
757 if (!list_empty(&rbio->hash_list)) {
758 /*
759 * if we're still cached and there is no other IO
760 * to perform, just leave this rbio here for others
761 * to steal from later
762 */
763 if (list_empty(&rbio->plug_list) &&
764 test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
765 keep_cache = 1;
766 clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
767 BUG_ON(!bio_list_empty(&rbio->bio_list));
768 goto done;
769 }
770
771 list_del_init(&rbio->hash_list);
772 refcount_dec(&rbio->refs);
773
774 /*
775 * we use the plug list to hold all the rbios
776 * waiting for the chance to lock this stripe.
777 * hand the lock over to one of them.
778 */
779 if (!list_empty(&rbio->plug_list)) {
780 struct btrfs_raid_bio *next;
781 struct list_head *head = rbio->plug_list.next;
782
783 next = list_entry(head, struct btrfs_raid_bio,
784 plug_list);
785
786 list_del_init(&rbio->plug_list);
787
788 list_add(&next->hash_list, &h->hash_list);
789 refcount_inc(&next->refs);
790 spin_unlock(&rbio->bio_list_lock);
791 spin_unlock_irqrestore(&h->lock, flags);
792
793 if (next->operation == BTRFS_RBIO_READ_REBUILD)
794 start_async_work(next, recover_rbio_work_locked);
795 else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) {
796 steal_rbio(rbio, next);
797 start_async_work(next, recover_rbio_work_locked);
798 } else if (next->operation == BTRFS_RBIO_WRITE) {
799 steal_rbio(rbio, next);
800 start_async_work(next, rmw_rbio_work_locked);
801 } else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
802 steal_rbio(rbio, next);
803 start_async_work(next, scrub_rbio_work_locked);
804 }
805
806 goto done_nolock;
807 }
808 }
809done:
810 spin_unlock(&rbio->bio_list_lock);
811 spin_unlock_irqrestore(&h->lock, flags);
812
813done_nolock:
814 if (!keep_cache)
815 remove_rbio_from_cache(rbio);
816}
817
818static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
819{
820 struct bio *next;
821
822 while (cur) {
823 next = cur->bi_next;
824 cur->bi_next = NULL;
825 cur->bi_status = err;
826 bio_endio(cur);
827 cur = next;
828 }
829}
830
831/*
832 * this frees the rbio and runs through all the bios in the
833 * bio_list and calls end_io on them
834 */
835static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err)
836{
837 struct bio *cur = bio_list_get(&rbio->bio_list);
838 struct bio *extra;
839
840 kfree(rbio->csum_buf);
841 bitmap_free(rbio->csum_bitmap);
842 rbio->csum_buf = NULL;
843 rbio->csum_bitmap = NULL;
844
845 /*
846 * Clear the data bitmap, as the rbio may be cached for later usage.
847 * do this before before unlock_stripe() so there will be no new bio
848 * for this bio.
849 */
850 bitmap_clear(&rbio->dbitmap, 0, rbio->stripe_nsectors);
851
852 /*
853 * At this moment, rbio->bio_list is empty, however since rbio does not
854 * always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the
855 * hash list, rbio may be merged with others so that rbio->bio_list
856 * becomes non-empty.
857 * Once unlock_stripe() is done, rbio->bio_list will not be updated any
858 * more and we can call bio_endio() on all queued bios.
859 */
860 unlock_stripe(rbio);
861 extra = bio_list_get(&rbio->bio_list);
862 free_raid_bio(rbio);
863
864 rbio_endio_bio_list(cur, err);
865 if (extra)
866 rbio_endio_bio_list(extra, err);
867}
868
869/*
870 * Get a sector pointer specified by its @stripe_nr and @sector_nr.
871 *
872 * @rbio: The raid bio
873 * @stripe_nr: Stripe number, valid range [0, real_stripe)
874 * @sector_nr: Sector number inside the stripe,
875 * valid range [0, stripe_nsectors)
876 * @bio_list_only: Whether to use sectors inside the bio list only.
877 *
878 * The read/modify/write code wants to reuse the original bio page as much
879 * as possible, and only use stripe_sectors as fallback.
880 */
881static struct sector_ptr *sector_in_rbio(struct btrfs_raid_bio *rbio,
882 int stripe_nr, int sector_nr,
883 bool bio_list_only)
884{
885 struct sector_ptr *sector;
886 int index;
887
888 ASSERT(stripe_nr >= 0 && stripe_nr < rbio->real_stripes);
889 ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
890
891 index = stripe_nr * rbio->stripe_nsectors + sector_nr;
892 ASSERT(index >= 0 && index < rbio->nr_sectors);
893
894 spin_lock_irq(&rbio->bio_list_lock);
895 sector = &rbio->bio_sectors[index];
896 if (sector->page || bio_list_only) {
897 /* Don't return sector without a valid page pointer */
898 if (!sector->page)
899 sector = NULL;
900 spin_unlock_irq(&rbio->bio_list_lock);
901 return sector;
902 }
903 spin_unlock_irq(&rbio->bio_list_lock);
904
905 return &rbio->stripe_sectors[index];
906}
907
908/*
909 * allocation and initial setup for the btrfs_raid_bio. Not
910 * this does not allocate any pages for rbio->pages.
911 */
912static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
913 struct btrfs_io_context *bioc)
914{
915 const unsigned int real_stripes = bioc->num_stripes - bioc->num_tgtdevs;
916 const unsigned int stripe_npages = BTRFS_STRIPE_LEN >> PAGE_SHIFT;
917 const unsigned int num_pages = stripe_npages * real_stripes;
918 const unsigned int stripe_nsectors =
919 BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
920 const unsigned int num_sectors = stripe_nsectors * real_stripes;
921 struct btrfs_raid_bio *rbio;
922
923 /* PAGE_SIZE must also be aligned to sectorsize for subpage support */
924 ASSERT(IS_ALIGNED(PAGE_SIZE, fs_info->sectorsize));
925 /*
926 * Our current stripe len should be fixed to 64k thus stripe_nsectors
927 * (at most 16) should be no larger than BITS_PER_LONG.
928 */
929 ASSERT(stripe_nsectors <= BITS_PER_LONG);
930
931 rbio = kzalloc(sizeof(*rbio), GFP_NOFS);
932 if (!rbio)
933 return ERR_PTR(-ENOMEM);
934 rbio->stripe_pages = kcalloc(num_pages, sizeof(struct page *),
935 GFP_NOFS);
936 rbio->bio_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
937 GFP_NOFS);
938 rbio->stripe_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
939 GFP_NOFS);
940 rbio->finish_pointers = kcalloc(real_stripes, sizeof(void *), GFP_NOFS);
941 rbio->error_bitmap = bitmap_zalloc(num_sectors, GFP_NOFS);
942
943 if (!rbio->stripe_pages || !rbio->bio_sectors || !rbio->stripe_sectors ||
944 !rbio->finish_pointers || !rbio->error_bitmap) {
945 free_raid_bio_pointers(rbio);
946 kfree(rbio);
947 return ERR_PTR(-ENOMEM);
948 }
949
950 bio_list_init(&rbio->bio_list);
951 init_waitqueue_head(&rbio->io_wait);
952 INIT_LIST_HEAD(&rbio->plug_list);
953 spin_lock_init(&rbio->bio_list_lock);
954 INIT_LIST_HEAD(&rbio->stripe_cache);
955 INIT_LIST_HEAD(&rbio->hash_list);
956 btrfs_get_bioc(bioc);
957 rbio->bioc = bioc;
958 rbio->nr_pages = num_pages;
959 rbio->nr_sectors = num_sectors;
960 rbio->real_stripes = real_stripes;
961 rbio->stripe_npages = stripe_npages;
962 rbio->stripe_nsectors = stripe_nsectors;
963 refcount_set(&rbio->refs, 1);
964 atomic_set(&rbio->stripes_pending, 0);
965
966 ASSERT(btrfs_nr_parity_stripes(bioc->map_type));
967 rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type);
968
969 return rbio;
970}
971
972/* allocate pages for all the stripes in the bio, including parity */
973static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
974{
975 int ret;
976
977 ret = btrfs_alloc_page_array(rbio->nr_pages, rbio->stripe_pages);
978 if (ret < 0)
979 return ret;
980 /* Mapping all sectors */
981 index_stripe_sectors(rbio);
982 return 0;
983}
984
985/* only allocate pages for p/q stripes */
986static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
987{
988 const int data_pages = rbio->nr_data * rbio->stripe_npages;
989 int ret;
990
991 ret = btrfs_alloc_page_array(rbio->nr_pages - data_pages,
992 rbio->stripe_pages + data_pages);
993 if (ret < 0)
994 return ret;
995
996 index_stripe_sectors(rbio);
997 return 0;
998}
999
1000/*
1001 * Return the total numer of errors found in the vertical stripe of @sector_nr.
1002 *
1003 * @faila and @failb will also be updated to the first and second stripe
1004 * number of the errors.
1005 */
1006static int get_rbio_veritical_errors(struct btrfs_raid_bio *rbio, int sector_nr,
1007 int *faila, int *failb)
1008{
1009 int stripe_nr;
1010 int found_errors = 0;
1011
1012 if (faila || failb) {
1013 /*
1014 * Both @faila and @failb should be valid pointers if any of
1015 * them is specified.
1016 */
1017 ASSERT(faila && failb);
1018 *faila = -1;
1019 *failb = -1;
1020 }
1021
1022 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1023 int total_sector_nr = stripe_nr * rbio->stripe_nsectors + sector_nr;
1024
1025 if (test_bit(total_sector_nr, rbio->error_bitmap)) {
1026 found_errors++;
1027 if (faila) {
1028 /* Update faila and failb. */
1029 if (*faila < 0)
1030 *faila = stripe_nr;
1031 else if (*failb < 0)
1032 *failb = stripe_nr;
1033 }
1034 }
1035 }
1036 return found_errors;
1037}
1038
1039/*
1040 * Add a single sector @sector into our list of bios for IO.
1041 *
1042 * Return 0 if everything went well.
1043 * Return <0 for error.
1044 */
1045static int rbio_add_io_sector(struct btrfs_raid_bio *rbio,
1046 struct bio_list *bio_list,
1047 struct sector_ptr *sector,
1048 unsigned int stripe_nr,
1049 unsigned int sector_nr,
1050 enum req_op op)
1051{
1052 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1053 struct bio *last = bio_list->tail;
1054 int ret;
1055 struct bio *bio;
1056 struct btrfs_io_stripe *stripe;
1057 u64 disk_start;
1058
1059 /*
1060 * Note: here stripe_nr has taken device replace into consideration,
1061 * thus it can be larger than rbio->real_stripe.
1062 * So here we check against bioc->num_stripes, not rbio->real_stripes.
1063 */
1064 ASSERT(stripe_nr >= 0 && stripe_nr < rbio->bioc->num_stripes);
1065 ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
1066 ASSERT(sector->page);
1067
1068 stripe = &rbio->bioc->stripes[stripe_nr];
1069 disk_start = stripe->physical + sector_nr * sectorsize;
1070
1071 /* if the device is missing, just fail this stripe */
1072 if (!stripe->dev->bdev) {
1073 int found_errors;
1074
1075 set_bit(stripe_nr * rbio->stripe_nsectors + sector_nr,
1076 rbio->error_bitmap);
1077
1078 /* Check if we have reached tolerance early. */
1079 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
1080 NULL, NULL);
1081 if (found_errors > rbio->bioc->max_errors)
1082 return -EIO;
1083 return 0;
1084 }
1085
1086 /* see if we can add this page onto our existing bio */
1087 if (last) {
1088 u64 last_end = last->bi_iter.bi_sector << 9;
1089 last_end += last->bi_iter.bi_size;
1090
1091 /*
1092 * we can't merge these if they are from different
1093 * devices or if they are not contiguous
1094 */
1095 if (last_end == disk_start && !last->bi_status &&
1096 last->bi_bdev == stripe->dev->bdev) {
1097 ret = bio_add_page(last, sector->page, sectorsize,
1098 sector->pgoff);
1099 if (ret == sectorsize)
1100 return 0;
1101 }
1102 }
1103
1104 /* put a new bio on the list */
1105 bio = bio_alloc(stripe->dev->bdev,
1106 max(BTRFS_STRIPE_LEN >> PAGE_SHIFT, 1),
1107 op, GFP_NOFS);
1108 bio->bi_iter.bi_sector = disk_start >> 9;
1109 bio->bi_private = rbio;
1110
1111 bio_add_page(bio, sector->page, sectorsize, sector->pgoff);
1112 bio_list_add(bio_list, bio);
1113 return 0;
1114}
1115
1116static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)
1117{
1118 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1119 struct bio_vec bvec;
1120 struct bvec_iter iter;
1121 u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1122 rbio->bioc->raid_map[0];
1123
1124 bio_for_each_segment(bvec, bio, iter) {
1125 u32 bvec_offset;
1126
1127 for (bvec_offset = 0; bvec_offset < bvec.bv_len;
1128 bvec_offset += sectorsize, offset += sectorsize) {
1129 int index = offset / sectorsize;
1130 struct sector_ptr *sector = &rbio->bio_sectors[index];
1131
1132 sector->page = bvec.bv_page;
1133 sector->pgoff = bvec.bv_offset + bvec_offset;
1134 ASSERT(sector->pgoff < PAGE_SIZE);
1135 }
1136 }
1137}
1138
1139/*
1140 * helper function to walk our bio list and populate the bio_pages array with
1141 * the result. This seems expensive, but it is faster than constantly
1142 * searching through the bio list as we setup the IO in finish_rmw or stripe
1143 * reconstruction.
1144 *
1145 * This must be called before you trust the answers from page_in_rbio
1146 */
1147static void index_rbio_pages(struct btrfs_raid_bio *rbio)
1148{
1149 struct bio *bio;
1150
1151 spin_lock_irq(&rbio->bio_list_lock);
1152 bio_list_for_each(bio, &rbio->bio_list)
1153 index_one_bio(rbio, bio);
1154
1155 spin_unlock_irq(&rbio->bio_list_lock);
1156}
1157
1158static void bio_get_trace_info(struct btrfs_raid_bio *rbio, struct bio *bio,
1159 struct raid56_bio_trace_info *trace_info)
1160{
1161 const struct btrfs_io_context *bioc = rbio->bioc;
1162 int i;
1163
1164 ASSERT(bioc);
1165
1166 /* We rely on bio->bi_bdev to find the stripe number. */
1167 if (!bio->bi_bdev)
1168 goto not_found;
1169
1170 for (i = 0; i < bioc->num_stripes; i++) {
1171 if (bio->bi_bdev != bioc->stripes[i].dev->bdev)
1172 continue;
1173 trace_info->stripe_nr = i;
1174 trace_info->devid = bioc->stripes[i].dev->devid;
1175 trace_info->offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1176 bioc->stripes[i].physical;
1177 return;
1178 }
1179
1180not_found:
1181 trace_info->devid = -1;
1182 trace_info->offset = -1;
1183 trace_info->stripe_nr = -1;
1184}
1185
1186/* Generate PQ for one veritical stripe. */
1187static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr)
1188{
1189 void **pointers = rbio->finish_pointers;
1190 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1191 struct sector_ptr *sector;
1192 int stripe;
1193 const bool has_qstripe = rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6;
1194
1195 /* First collect one sector from each data stripe */
1196 for (stripe = 0; stripe < rbio->nr_data; stripe++) {
1197 sector = sector_in_rbio(rbio, stripe, sectornr, 0);
1198 pointers[stripe] = kmap_local_page(sector->page) +
1199 sector->pgoff;
1200 }
1201
1202 /* Then add the parity stripe */
1203 sector = rbio_pstripe_sector(rbio, sectornr);
1204 sector->uptodate = 1;
1205 pointers[stripe++] = kmap_local_page(sector->page) + sector->pgoff;
1206
1207 if (has_qstripe) {
1208 /*
1209 * RAID6, add the qstripe and call the library function
1210 * to fill in our p/q
1211 */
1212 sector = rbio_qstripe_sector(rbio, sectornr);
1213 sector->uptodate = 1;
1214 pointers[stripe++] = kmap_local_page(sector->page) +
1215 sector->pgoff;
1216
1217 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
1218 pointers);
1219 } else {
1220 /* raid5 */
1221 memcpy(pointers[rbio->nr_data], pointers[0], sectorsize);
1222 run_xor(pointers + 1, rbio->nr_data - 1, sectorsize);
1223 }
1224 for (stripe = stripe - 1; stripe >= 0; stripe--)
1225 kunmap_local(pointers[stripe]);
1226}
1227
1228static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio,
1229 struct bio_list *bio_list)
1230{
1231 struct bio *bio;
1232 /* The total sector number inside the full stripe. */
1233 int total_sector_nr;
1234 int sectornr;
1235 int stripe;
1236 int ret;
1237
1238 ASSERT(bio_list_size(bio_list) == 0);
1239
1240 /* We should have at least one data sector. */
1241 ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));
1242
1243 /*
1244 * Reset errors, as we may have errors inherited from from degraded
1245 * write.
1246 */
1247 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
1248
1249 /*
1250 * Start assembly. Make bios for everything from the higher layers (the
1251 * bio_list in our rbio) and our P/Q. Ignore everything else.
1252 */
1253 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1254 total_sector_nr++) {
1255 struct sector_ptr *sector;
1256
1257 stripe = total_sector_nr / rbio->stripe_nsectors;
1258 sectornr = total_sector_nr % rbio->stripe_nsectors;
1259
1260 /* This vertical stripe has no data, skip it. */
1261 if (!test_bit(sectornr, &rbio->dbitmap))
1262 continue;
1263
1264 if (stripe < rbio->nr_data) {
1265 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1266 if (!sector)
1267 continue;
1268 } else {
1269 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1270 }
1271
1272 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
1273 sectornr, REQ_OP_WRITE);
1274 if (ret)
1275 goto error;
1276 }
1277
1278 if (likely(!rbio->bioc->num_tgtdevs))
1279 return 0;
1280
1281 /* Make a copy for the replace target device. */
1282 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1283 total_sector_nr++) {
1284 struct sector_ptr *sector;
1285
1286 stripe = total_sector_nr / rbio->stripe_nsectors;
1287 sectornr = total_sector_nr % rbio->stripe_nsectors;
1288
1289 if (!rbio->bioc->tgtdev_map[stripe]) {
1290 /*
1291 * We can skip the whole stripe completely, note
1292 * total_sector_nr will be increased by one anyway.
1293 */
1294 ASSERT(sectornr == 0);
1295 total_sector_nr += rbio->stripe_nsectors - 1;
1296 continue;
1297 }
1298
1299 /* This vertical stripe has no data, skip it. */
1300 if (!test_bit(sectornr, &rbio->dbitmap))
1301 continue;
1302
1303 if (stripe < rbio->nr_data) {
1304 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1305 if (!sector)
1306 continue;
1307 } else {
1308 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1309 }
1310
1311 ret = rbio_add_io_sector(rbio, bio_list, sector,
1312 rbio->bioc->tgtdev_map[stripe],
1313 sectornr, REQ_OP_WRITE);
1314 if (ret)
1315 goto error;
1316 }
1317
1318 return 0;
1319error:
1320 while ((bio = bio_list_pop(bio_list)))
1321 bio_put(bio);
1322 return -EIO;
1323}
1324
1325static void set_rbio_range_error(struct btrfs_raid_bio *rbio, struct bio *bio)
1326{
1327 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1328 u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
1329 rbio->bioc->raid_map[0];
1330 int total_nr_sector = offset >> fs_info->sectorsize_bits;
1331
1332 ASSERT(total_nr_sector < rbio->nr_data * rbio->stripe_nsectors);
1333
1334 bitmap_set(rbio->error_bitmap, total_nr_sector,
1335 bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
1336
1337 /*
1338 * Special handling for raid56_alloc_missing_rbio() used by
1339 * scrub/replace. Unlike call path in raid56_parity_recover(), they
1340 * pass an empty bio here. Thus we have to find out the missing device
1341 * and mark the stripe error instead.
1342 */
1343 if (bio->bi_iter.bi_size == 0) {
1344 bool found_missing = false;
1345 int stripe_nr;
1346
1347 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1348 if (!rbio->bioc->stripes[stripe_nr].dev->bdev) {
1349 found_missing = true;
1350 bitmap_set(rbio->error_bitmap,
1351 stripe_nr * rbio->stripe_nsectors,
1352 rbio->stripe_nsectors);
1353 }
1354 }
1355 ASSERT(found_missing);
1356 }
1357}
1358
1359/*
1360 * For subpage case, we can no longer set page Uptodate directly for
1361 * stripe_pages[], thus we need to locate the sector.
1362 */
1363static struct sector_ptr *find_stripe_sector(struct btrfs_raid_bio *rbio,
1364 struct page *page,
1365 unsigned int pgoff)
1366{
1367 int i;
1368
1369 for (i = 0; i < rbio->nr_sectors; i++) {
1370 struct sector_ptr *sector = &rbio->stripe_sectors[i];
1371
1372 if (sector->page == page && sector->pgoff == pgoff)
1373 return sector;
1374 }
1375 return NULL;
1376}
1377
1378/*
1379 * this sets each page in the bio uptodate. It should only be used on private
1380 * rbio pages, nothing that comes in from the higher layers
1381 */
1382static void set_bio_pages_uptodate(struct btrfs_raid_bio *rbio, struct bio *bio)
1383{
1384 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1385 struct bio_vec *bvec;
1386 struct bvec_iter_all iter_all;
1387
1388 ASSERT(!bio_flagged(bio, BIO_CLONED));
1389
1390 bio_for_each_segment_all(bvec, bio, iter_all) {
1391 struct sector_ptr *sector;
1392 int pgoff;
1393
1394 for (pgoff = bvec->bv_offset; pgoff - bvec->bv_offset < bvec->bv_len;
1395 pgoff += sectorsize) {
1396 sector = find_stripe_sector(rbio, bvec->bv_page, pgoff);
1397 ASSERT(sector);
1398 if (sector)
1399 sector->uptodate = 1;
1400 }
1401 }
1402}
1403
1404static int get_bio_sector_nr(struct btrfs_raid_bio *rbio, struct bio *bio)
1405{
1406 struct bio_vec *bv = bio_first_bvec_all(bio);
1407 int i;
1408
1409 for (i = 0; i < rbio->nr_sectors; i++) {
1410 struct sector_ptr *sector;
1411
1412 sector = &rbio->stripe_sectors[i];
1413 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1414 break;
1415 sector = &rbio->bio_sectors[i];
1416 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1417 break;
1418 }
1419 ASSERT(i < rbio->nr_sectors);
1420 return i;
1421}
1422
1423static void rbio_update_error_bitmap(struct btrfs_raid_bio *rbio, struct bio *bio)
1424{
1425 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1426 u32 bio_size = 0;
1427 struct bio_vec *bvec;
1428 struct bvec_iter_all iter_all;
1429 int i;
1430
1431 bio_for_each_segment_all(bvec, bio, iter_all)
1432 bio_size += bvec->bv_len;
1433
1434 /*
1435 * Since we can have multiple bios touching the error_bitmap, we cannot
1436 * call bitmap_set() without protection.
1437 *
1438 * Instead use set_bit() for each bit, as set_bit() itself is atomic.
1439 */
1440 for (i = total_sector_nr; i < total_sector_nr +
1441 (bio_size >> rbio->bioc->fs_info->sectorsize_bits); i++)
1442 set_bit(i, rbio->error_bitmap);
1443}
1444
1445/* Verify the data sectors at read time. */
1446static void verify_bio_data_sectors(struct btrfs_raid_bio *rbio,
1447 struct bio *bio)
1448{
1449 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1450 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1451 struct bio_vec *bvec;
1452 struct bvec_iter_all iter_all;
1453
1454 /* No data csum for the whole stripe, no need to verify. */
1455 if (!rbio->csum_bitmap || !rbio->csum_buf)
1456 return;
1457
1458 /* P/Q stripes, they have no data csum to verify against. */
1459 if (total_sector_nr >= rbio->nr_data * rbio->stripe_nsectors)
1460 return;
1461
1462 bio_for_each_segment_all(bvec, bio, iter_all) {
1463 int bv_offset;
1464
1465 for (bv_offset = bvec->bv_offset;
1466 bv_offset < bvec->bv_offset + bvec->bv_len;
1467 bv_offset += fs_info->sectorsize, total_sector_nr++) {
1468 u8 csum_buf[BTRFS_CSUM_SIZE];
1469 u8 *expected_csum = rbio->csum_buf +
1470 total_sector_nr * fs_info->csum_size;
1471 int ret;
1472
1473 /* No csum for this sector, skip to the next sector. */
1474 if (!test_bit(total_sector_nr, rbio->csum_bitmap))
1475 continue;
1476
1477 ret = btrfs_check_sector_csum(fs_info, bvec->bv_page,
1478 bv_offset, csum_buf, expected_csum);
1479 if (ret < 0)
1480 set_bit(total_sector_nr, rbio->error_bitmap);
1481 }
1482 }
1483}
1484
1485static void raid_wait_read_end_io(struct bio *bio)
1486{
1487 struct btrfs_raid_bio *rbio = bio->bi_private;
1488
1489 if (bio->bi_status) {
1490 rbio_update_error_bitmap(rbio, bio);
1491 } else {
1492 set_bio_pages_uptodate(rbio, bio);
1493 verify_bio_data_sectors(rbio, bio);
1494 }
1495
1496 bio_put(bio);
1497 if (atomic_dec_and_test(&rbio->stripes_pending))
1498 wake_up(&rbio->io_wait);
1499}
1500
1501static void submit_read_bios(struct btrfs_raid_bio *rbio,
1502 struct bio_list *bio_list)
1503{
1504 struct bio *bio;
1505
1506 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
1507 while ((bio = bio_list_pop(bio_list))) {
1508 bio->bi_end_io = raid_wait_read_end_io;
1509
1510 if (trace_raid56_scrub_read_recover_enabled()) {
1511 struct raid56_bio_trace_info trace_info = { 0 };
1512
1513 bio_get_trace_info(rbio, bio, &trace_info);
1514 trace_raid56_scrub_read_recover(rbio, bio, &trace_info);
1515 }
1516 submit_bio(bio);
1517 }
1518}
1519
1520static int rmw_assemble_read_bios(struct btrfs_raid_bio *rbio,
1521 struct bio_list *bio_list)
1522{
1523 struct bio *bio;
1524 int total_sector_nr;
1525 int ret = 0;
1526
1527 ASSERT(bio_list_size(bio_list) == 0);
1528
1529 /*
1530 * Build a list of bios to read all sectors (including data and P/Q).
1531 *
1532 * This behaviro is to compensate the later csum verification and
1533 * recovery.
1534 */
1535 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1536 total_sector_nr++) {
1537 struct sector_ptr *sector;
1538 int stripe = total_sector_nr / rbio->stripe_nsectors;
1539 int sectornr = total_sector_nr % rbio->stripe_nsectors;
1540
1541 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1542 ret = rbio_add_io_sector(rbio, bio_list, sector,
1543 stripe, sectornr, REQ_OP_READ);
1544 if (ret)
1545 goto cleanup;
1546 }
1547 return 0;
1548
1549cleanup:
1550 while ((bio = bio_list_pop(bio_list)))
1551 bio_put(bio);
1552 return ret;
1553}
1554
1555static int alloc_rbio_data_pages(struct btrfs_raid_bio *rbio)
1556{
1557 const int data_pages = rbio->nr_data * rbio->stripe_npages;
1558 int ret;
1559
1560 ret = btrfs_alloc_page_array(data_pages, rbio->stripe_pages);
1561 if (ret < 0)
1562 return ret;
1563
1564 index_stripe_sectors(rbio);
1565 return 0;
1566}
1567
1568/*
1569 * We use plugging call backs to collect full stripes.
1570 * Any time we get a partial stripe write while plugged
1571 * we collect it into a list. When the unplug comes down,
1572 * we sort the list by logical block number and merge
1573 * everything we can into the same rbios
1574 */
1575struct btrfs_plug_cb {
1576 struct blk_plug_cb cb;
1577 struct btrfs_fs_info *info;
1578 struct list_head rbio_list;
1579 struct work_struct work;
1580};
1581
1582/*
1583 * rbios on the plug list are sorted for easier merging.
1584 */
1585static int plug_cmp(void *priv, const struct list_head *a,
1586 const struct list_head *b)
1587{
1588 const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
1589 plug_list);
1590 const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
1591 plug_list);
1592 u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
1593 u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
1594
1595 if (a_sector < b_sector)
1596 return -1;
1597 if (a_sector > b_sector)
1598 return 1;
1599 return 0;
1600}
1601
1602static void raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
1603{
1604 struct btrfs_plug_cb *plug = container_of(cb, struct btrfs_plug_cb, cb);
1605 struct btrfs_raid_bio *cur;
1606 struct btrfs_raid_bio *last = NULL;
1607
1608 list_sort(NULL, &plug->rbio_list, plug_cmp);
1609
1610 while (!list_empty(&plug->rbio_list)) {
1611 cur = list_entry(plug->rbio_list.next,
1612 struct btrfs_raid_bio, plug_list);
1613 list_del_init(&cur->plug_list);
1614
1615 if (rbio_is_full(cur)) {
1616 /* We have a full stripe, queue it down. */
1617 start_async_work(cur, rmw_rbio_work);
1618 continue;
1619 }
1620 if (last) {
1621 if (rbio_can_merge(last, cur)) {
1622 merge_rbio(last, cur);
1623 free_raid_bio(cur);
1624 continue;
1625 }
1626 start_async_work(last, rmw_rbio_work);
1627 }
1628 last = cur;
1629 }
1630 if (last)
1631 start_async_work(last, rmw_rbio_work);
1632 kfree(plug);
1633}
1634
1635/* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */
1636static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio)
1637{
1638 const struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1639 const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT;
1640 const u64 full_stripe_start = rbio->bioc->raid_map[0];
1641 const u32 orig_len = orig_bio->bi_iter.bi_size;
1642 const u32 sectorsize = fs_info->sectorsize;
1643 u64 cur_logical;
1644
1645 ASSERT(orig_logical >= full_stripe_start &&
1646 orig_logical + orig_len <= full_stripe_start +
1647 rbio->nr_data * BTRFS_STRIPE_LEN);
1648
1649 bio_list_add(&rbio->bio_list, orig_bio);
1650 rbio->bio_list_bytes += orig_bio->bi_iter.bi_size;
1651
1652 /* Update the dbitmap. */
1653 for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len;
1654 cur_logical += sectorsize) {
1655 int bit = ((u32)(cur_logical - full_stripe_start) >>
1656 fs_info->sectorsize_bits) % rbio->stripe_nsectors;
1657
1658 set_bit(bit, &rbio->dbitmap);
1659 }
1660}
1661
1662/*
1663 * our main entry point for writes from the rest of the FS.
1664 */
1665void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
1666{
1667 struct btrfs_fs_info *fs_info = bioc->fs_info;
1668 struct btrfs_raid_bio *rbio;
1669 struct btrfs_plug_cb *plug = NULL;
1670 struct blk_plug_cb *cb;
1671 int ret = 0;
1672
1673 rbio = alloc_rbio(fs_info, bioc);
1674 if (IS_ERR(rbio)) {
1675 ret = PTR_ERR(rbio);
1676 goto fail;
1677 }
1678 rbio->operation = BTRFS_RBIO_WRITE;
1679 rbio_add_bio(rbio, bio);
1680
1681 /*
1682 * Don't plug on full rbios, just get them out the door
1683 * as quickly as we can
1684 */
1685 if (rbio_is_full(rbio))
1686 goto queue_rbio;
1687
1688 cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
1689 if (cb) {
1690 plug = container_of(cb, struct btrfs_plug_cb, cb);
1691 if (!plug->info) {
1692 plug->info = fs_info;
1693 INIT_LIST_HEAD(&plug->rbio_list);
1694 }
1695 list_add_tail(&rbio->plug_list, &plug->rbio_list);
1696 return;
1697 }
1698queue_rbio:
1699 /*
1700 * Either we don't have any existing plug, or we're doing a full stripe,
1701 * can queue the rmw work now.
1702 */
1703 start_async_work(rbio, rmw_rbio_work);
1704
1705 return;
1706
1707fail:
1708 bio->bi_status = errno_to_blk_status(ret);
1709 bio_endio(bio);
1710}
1711
1712static int verify_one_sector(struct btrfs_raid_bio *rbio,
1713 int stripe_nr, int sector_nr)
1714{
1715 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1716 struct sector_ptr *sector;
1717 u8 csum_buf[BTRFS_CSUM_SIZE];
1718 u8 *csum_expected;
1719 int ret;
1720
1721 if (!rbio->csum_bitmap || !rbio->csum_buf)
1722 return 0;
1723
1724 /* No way to verify P/Q as they are not covered by data csum. */
1725 if (stripe_nr >= rbio->nr_data)
1726 return 0;
1727 /*
1728 * If we're rebuilding a read, we have to use pages from the
1729 * bio list if possible.
1730 */
1731 if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1732 rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) {
1733 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1734 } else {
1735 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1736 }
1737
1738 ASSERT(sector->page);
1739
1740 csum_expected = rbio->csum_buf +
1741 (stripe_nr * rbio->stripe_nsectors + sector_nr) *
1742 fs_info->csum_size;
1743 ret = btrfs_check_sector_csum(fs_info, sector->page, sector->pgoff,
1744 csum_buf, csum_expected);
1745 return ret;
1746}
1747
1748/*
1749 * Recover a vertical stripe specified by @sector_nr.
1750 * @*pointers are the pre-allocated pointers by the caller, so we don't
1751 * need to allocate/free the pointers again and again.
1752 */
1753static int recover_vertical(struct btrfs_raid_bio *rbio, int sector_nr,
1754 void **pointers, void **unmap_array)
1755{
1756 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1757 struct sector_ptr *sector;
1758 const u32 sectorsize = fs_info->sectorsize;
1759 int found_errors;
1760 int faila;
1761 int failb;
1762 int stripe_nr;
1763 int ret = 0;
1764
1765 /*
1766 * Now we just use bitmap to mark the horizontal stripes in
1767 * which we have data when doing parity scrub.
1768 */
1769 if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
1770 !test_bit(sector_nr, &rbio->dbitmap))
1771 return 0;
1772
1773 found_errors = get_rbio_veritical_errors(rbio, sector_nr, &faila,
1774 &failb);
1775 /*
1776 * No errors in the veritical stripe, skip it. Can happen for recovery
1777 * which only part of a stripe failed csum check.
1778 */
1779 if (!found_errors)
1780 return 0;
1781
1782 if (found_errors > rbio->bioc->max_errors)
1783 return -EIO;
1784
1785 /*
1786 * Setup our array of pointers with sectors from each stripe
1787 *
1788 * NOTE: store a duplicate array of pointers to preserve the
1789 * pointer order.
1790 */
1791 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1792 /*
1793 * If we're rebuilding a read, we have to use pages from the
1794 * bio list if possible.
1795 */
1796 if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1797 rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) {
1798 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1799 } else {
1800 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1801 }
1802 ASSERT(sector->page);
1803 pointers[stripe_nr] = kmap_local_page(sector->page) +
1804 sector->pgoff;
1805 unmap_array[stripe_nr] = pointers[stripe_nr];
1806 }
1807
1808 /* All raid6 handling here */
1809 if (rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6) {
1810 /* Single failure, rebuild from parity raid5 style */
1811 if (failb < 0) {
1812 if (faila == rbio->nr_data)
1813 /*
1814 * Just the P stripe has failed, without
1815 * a bad data or Q stripe.
1816 * We have nothing to do, just skip the
1817 * recovery for this stripe.
1818 */
1819 goto cleanup;
1820 /*
1821 * a single failure in raid6 is rebuilt
1822 * in the pstripe code below
1823 */
1824 goto pstripe;
1825 }
1826
1827 /*
1828 * If the q stripe is failed, do a pstripe reconstruction from
1829 * the xors.
1830 * If both the q stripe and the P stripe are failed, we're
1831 * here due to a crc mismatch and we can't give them the
1832 * data they want.
1833 */
1834 if (rbio->bioc->raid_map[failb] == RAID6_Q_STRIPE) {
1835 if (rbio->bioc->raid_map[faila] ==
1836 RAID5_P_STRIPE)
1837 /*
1838 * Only P and Q are corrupted.
1839 * We only care about data stripes recovery,
1840 * can skip this vertical stripe.
1841 */
1842 goto cleanup;
1843 /*
1844 * Otherwise we have one bad data stripe and
1845 * a good P stripe. raid5!
1846 */
1847 goto pstripe;
1848 }
1849
1850 if (rbio->bioc->raid_map[failb] == RAID5_P_STRIPE) {
1851 raid6_datap_recov(rbio->real_stripes, sectorsize,
1852 faila, pointers);
1853 } else {
1854 raid6_2data_recov(rbio->real_stripes, sectorsize,
1855 faila, failb, pointers);
1856 }
1857 } else {
1858 void *p;
1859
1860 /* Rebuild from P stripe here (raid5 or raid6). */
1861 ASSERT(failb == -1);
1862pstripe:
1863 /* Copy parity block into failed block to start with */
1864 memcpy(pointers[faila], pointers[rbio->nr_data], sectorsize);
1865
1866 /* Rearrange the pointer array */
1867 p = pointers[faila];
1868 for (stripe_nr = faila; stripe_nr < rbio->nr_data - 1;
1869 stripe_nr++)
1870 pointers[stripe_nr] = pointers[stripe_nr + 1];
1871 pointers[rbio->nr_data - 1] = p;
1872
1873 /* Xor in the rest */
1874 run_xor(pointers, rbio->nr_data - 1, sectorsize);
1875
1876 }
1877
1878 /*
1879 * No matter if this is a RMW or recovery, we should have all
1880 * failed sectors repaired in the vertical stripe, thus they are now
1881 * uptodate.
1882 * Especially if we determine to cache the rbio, we need to
1883 * have at least all data sectors uptodate.
1884 *
1885 * If possible, also check if the repaired sector matches its data
1886 * checksum.
1887 */
1888 if (faila >= 0) {
1889 ret = verify_one_sector(rbio, faila, sector_nr);
1890 if (ret < 0)
1891 goto cleanup;
1892
1893 sector = rbio_stripe_sector(rbio, faila, sector_nr);
1894 sector->uptodate = 1;
1895 }
1896 if (failb >= 0) {
1897 ret = verify_one_sector(rbio, failb, sector_nr);
1898 if (ret < 0)
1899 goto cleanup;
1900
1901 sector = rbio_stripe_sector(rbio, failb, sector_nr);
1902 sector->uptodate = 1;
1903 }
1904
1905cleanup:
1906 for (stripe_nr = rbio->real_stripes - 1; stripe_nr >= 0; stripe_nr--)
1907 kunmap_local(unmap_array[stripe_nr]);
1908 return ret;
1909}
1910
1911static int recover_sectors(struct btrfs_raid_bio *rbio)
1912{
1913 void **pointers = NULL;
1914 void **unmap_array = NULL;
1915 int sectornr;
1916 int ret = 0;
1917
1918 /*
1919 * @pointers array stores the pointer for each sector.
1920 *
1921 * @unmap_array stores copy of pointers that does not get reordered
1922 * during reconstruction so that kunmap_local works.
1923 */
1924 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1925 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1926 if (!pointers || !unmap_array) {
1927 ret = -ENOMEM;
1928 goto out;
1929 }
1930
1931 if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1932 rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
1933 spin_lock_irq(&rbio->bio_list_lock);
1934 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
1935 spin_unlock_irq(&rbio->bio_list_lock);
1936 }
1937
1938 index_rbio_pages(rbio);
1939
1940 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
1941 ret = recover_vertical(rbio, sectornr, pointers, unmap_array);
1942 if (ret < 0)
1943 break;
1944 }
1945
1946out:
1947 kfree(pointers);
1948 kfree(unmap_array);
1949 return ret;
1950}
1951
1952static int recover_assemble_read_bios(struct btrfs_raid_bio *rbio,
1953 struct bio_list *bio_list)
1954{
1955 struct bio *bio;
1956 int total_sector_nr;
1957 int ret = 0;
1958
1959 ASSERT(bio_list_size(bio_list) == 0);
1960 /*
1961 * Read everything that hasn't failed. However this time we will
1962 * not trust any cached sector.
1963 * As we may read out some stale data but higher layer is not reading
1964 * that stale part.
1965 *
1966 * So here we always re-read everything in recovery path.
1967 */
1968 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1969 total_sector_nr++) {
1970 int stripe = total_sector_nr / rbio->stripe_nsectors;
1971 int sectornr = total_sector_nr % rbio->stripe_nsectors;
1972 struct sector_ptr *sector;
1973
1974 /*
1975 * Skip the range which has error. It can be a range which is
1976 * marked error (for csum mismatch), or it can be a missing
1977 * device.
1978 */
1979 if (!rbio->bioc->stripes[stripe].dev->bdev ||
1980 test_bit(total_sector_nr, rbio->error_bitmap)) {
1981 /*
1982 * Also set the error bit for missing device, which
1983 * may not yet have its error bit set.
1984 */
1985 set_bit(total_sector_nr, rbio->error_bitmap);
1986 continue;
1987 }
1988
1989 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1990 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
1991 sectornr, REQ_OP_READ);
1992 if (ret < 0)
1993 goto error;
1994 }
1995 return 0;
1996error:
1997 while ((bio = bio_list_pop(bio_list)))
1998 bio_put(bio);
1999
2000 return -EIO;
2001}
2002
2003static int recover_rbio(struct btrfs_raid_bio *rbio)
2004{
2005 struct bio_list bio_list;
2006 struct bio *bio;
2007 int ret;
2008
2009 /*
2010 * Either we're doing recover for a read failure or degraded write,
2011 * caller should have set error bitmap correctly.
2012 */
2013 ASSERT(bitmap_weight(rbio->error_bitmap, rbio->nr_sectors));
2014 bio_list_init(&bio_list);
2015
2016 /* For recovery, we need to read all sectors including P/Q. */
2017 ret = alloc_rbio_pages(rbio);
2018 if (ret < 0)
2019 goto out;
2020
2021 index_rbio_pages(rbio);
2022
2023 ret = recover_assemble_read_bios(rbio, &bio_list);
2024 if (ret < 0)
2025 goto out;
2026
2027 submit_read_bios(rbio, &bio_list);
2028 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2029
2030 ret = recover_sectors(rbio);
2031
2032out:
2033 while ((bio = bio_list_pop(&bio_list)))
2034 bio_put(bio);
2035
2036 return ret;
2037}
2038
2039static void recover_rbio_work(struct work_struct *work)
2040{
2041 struct btrfs_raid_bio *rbio;
2042 int ret;
2043
2044 rbio = container_of(work, struct btrfs_raid_bio, work);
2045
2046 ret = lock_stripe_add(rbio);
2047 if (ret == 0) {
2048 ret = recover_rbio(rbio);
2049 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2050 }
2051}
2052
2053static void recover_rbio_work_locked(struct work_struct *work)
2054{
2055 struct btrfs_raid_bio *rbio;
2056 int ret;
2057
2058 rbio = container_of(work, struct btrfs_raid_bio, work);
2059
2060 ret = recover_rbio(rbio);
2061 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2062}
2063
2064static void set_rbio_raid6_extra_error(struct btrfs_raid_bio *rbio, int mirror_num)
2065{
2066 bool found = false;
2067 int sector_nr;
2068
2069 /*
2070 * This is for RAID6 extra recovery tries, thus mirror number should
2071 * be large than 2.
2072 * Mirror 1 means read from data stripes. Mirror 2 means rebuild using
2073 * RAID5 methods.
2074 */
2075 ASSERT(mirror_num > 2);
2076 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2077 int found_errors;
2078 int faila;
2079 int failb;
2080
2081 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2082 &faila, &failb);
2083 /* This vertical stripe doesn't have errors. */
2084 if (!found_errors)
2085 continue;
2086
2087 /*
2088 * If we found errors, there should be only one error marked
2089 * by previous set_rbio_range_error().
2090 */
2091 ASSERT(found_errors == 1);
2092 found = true;
2093
2094 /* Now select another stripe to mark as error. */
2095 failb = rbio->real_stripes - (mirror_num - 1);
2096 if (failb <= faila)
2097 failb--;
2098
2099 /* Set the extra bit in error bitmap. */
2100 if (failb >= 0)
2101 set_bit(failb * rbio->stripe_nsectors + sector_nr,
2102 rbio->error_bitmap);
2103 }
2104
2105 /* We should found at least one vertical stripe with error.*/
2106 ASSERT(found);
2107}
2108
2109/*
2110 * the main entry point for reads from the higher layers. This
2111 * is really only called when the normal read path had a failure,
2112 * so we assume the bio they send down corresponds to a failed part
2113 * of the drive.
2114 */
2115void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
2116 int mirror_num)
2117{
2118 struct btrfs_fs_info *fs_info = bioc->fs_info;
2119 struct btrfs_raid_bio *rbio;
2120
2121 rbio = alloc_rbio(fs_info, bioc);
2122 if (IS_ERR(rbio)) {
2123 bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
2124 bio_endio(bio);
2125 return;
2126 }
2127
2128 rbio->operation = BTRFS_RBIO_READ_REBUILD;
2129 rbio_add_bio(rbio, bio);
2130
2131 set_rbio_range_error(rbio, bio);
2132
2133 /*
2134 * Loop retry:
2135 * for 'mirror == 2', reconstruct from all other stripes.
2136 * for 'mirror_num > 2', select a stripe to fail on every retry.
2137 */
2138 if (mirror_num > 2)
2139 set_rbio_raid6_extra_error(rbio, mirror_num);
2140
2141 start_async_work(rbio, recover_rbio_work);
2142}
2143
2144static void fill_data_csums(struct btrfs_raid_bio *rbio)
2145{
2146 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
2147 struct btrfs_root *csum_root = btrfs_csum_root(fs_info,
2148 rbio->bioc->raid_map[0]);
2149 const u64 start = rbio->bioc->raid_map[0];
2150 const u32 len = (rbio->nr_data * rbio->stripe_nsectors) <<
2151 fs_info->sectorsize_bits;
2152 int ret;
2153
2154 /* The rbio should not have its csum buffer initialized. */
2155 ASSERT(!rbio->csum_buf && !rbio->csum_bitmap);
2156
2157 /*
2158 * Skip the csum search if:
2159 *
2160 * - The rbio doesn't belong to data block groups
2161 * Then we are doing IO for tree blocks, no need to search csums.
2162 *
2163 * - The rbio belongs to mixed block groups
2164 * This is to avoid deadlock, as we're already holding the full
2165 * stripe lock, if we trigger a metadata read, and it needs to do
2166 * raid56 recovery, we will deadlock.
2167 */
2168 if (!(rbio->bioc->map_type & BTRFS_BLOCK_GROUP_DATA) ||
2169 rbio->bioc->map_type & BTRFS_BLOCK_GROUP_METADATA)
2170 return;
2171
2172 rbio->csum_buf = kzalloc(rbio->nr_data * rbio->stripe_nsectors *
2173 fs_info->csum_size, GFP_NOFS);
2174 rbio->csum_bitmap = bitmap_zalloc(rbio->nr_data * rbio->stripe_nsectors,
2175 GFP_NOFS);
2176 if (!rbio->csum_buf || !rbio->csum_bitmap) {
2177 ret = -ENOMEM;
2178 goto error;
2179 }
2180
2181 ret = btrfs_lookup_csums_bitmap(csum_root, start, start + len - 1,
2182 rbio->csum_buf, rbio->csum_bitmap);
2183 if (ret < 0)
2184 goto error;
2185 if (bitmap_empty(rbio->csum_bitmap, len >> fs_info->sectorsize_bits))
2186 goto no_csum;
2187 return;
2188
2189error:
2190 /*
2191 * We failed to allocate memory or grab the csum, but it's not fatal,
2192 * we can still continue. But better to warn users that RMW is no
2193 * longer safe for this particular sub-stripe write.
2194 */
2195 btrfs_warn_rl(fs_info,
2196"sub-stripe write for full stripe %llu is not safe, failed to get csum: %d",
2197 rbio->bioc->raid_map[0], ret);
2198no_csum:
2199 kfree(rbio->csum_buf);
2200 bitmap_free(rbio->csum_bitmap);
2201 rbio->csum_buf = NULL;
2202 rbio->csum_bitmap = NULL;
2203}
2204
2205static int rmw_read_wait_recover(struct btrfs_raid_bio *rbio)
2206{
2207 struct bio_list bio_list;
2208 struct bio *bio;
2209 int ret;
2210
2211 bio_list_init(&bio_list);
2212
2213 /*
2214 * Fill the data csums we need for data verification. We need to fill
2215 * the csum_bitmap/csum_buf first, as our endio function will try to
2216 * verify the data sectors.
2217 */
2218 fill_data_csums(rbio);
2219
2220 ret = rmw_assemble_read_bios(rbio, &bio_list);
2221 if (ret < 0)
2222 goto out;
2223
2224 submit_read_bios(rbio, &bio_list);
2225 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2226
2227 /*
2228 * We may or may not have any corrupted sectors (including missing dev
2229 * and csum mismatch), just let recover_sectors() to handle them all.
2230 */
2231 ret = recover_sectors(rbio);
2232 return ret;
2233out:
2234 while ((bio = bio_list_pop(&bio_list)))
2235 bio_put(bio);
2236
2237 return ret;
2238}
2239
2240static void raid_wait_write_end_io(struct bio *bio)
2241{
2242 struct btrfs_raid_bio *rbio = bio->bi_private;
2243 blk_status_t err = bio->bi_status;
2244
2245 if (err)
2246 rbio_update_error_bitmap(rbio, bio);
2247 bio_put(bio);
2248 if (atomic_dec_and_test(&rbio->stripes_pending))
2249 wake_up(&rbio->io_wait);
2250}
2251
2252static void submit_write_bios(struct btrfs_raid_bio *rbio,
2253 struct bio_list *bio_list)
2254{
2255 struct bio *bio;
2256
2257 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
2258 while ((bio = bio_list_pop(bio_list))) {
2259 bio->bi_end_io = raid_wait_write_end_io;
2260
2261 if (trace_raid56_write_stripe_enabled()) {
2262 struct raid56_bio_trace_info trace_info = { 0 };
2263
2264 bio_get_trace_info(rbio, bio, &trace_info);
2265 trace_raid56_write_stripe(rbio, bio, &trace_info);
2266 }
2267 submit_bio(bio);
2268 }
2269}
2270
2271/*
2272 * To determine if we need to read any sector from the disk.
2273 * Should only be utilized in RMW path, to skip cached rbio.
2274 */
2275static bool need_read_stripe_sectors(struct btrfs_raid_bio *rbio)
2276{
2277 int i;
2278
2279 for (i = 0; i < rbio->nr_data * rbio->stripe_nsectors; i++) {
2280 struct sector_ptr *sector = &rbio->stripe_sectors[i];
2281
2282 /*
2283 * We have a sector which doesn't have page nor uptodate,
2284 * thus this rbio can not be cached one, as cached one must
2285 * have all its data sectors present and uptodate.
2286 */
2287 if (!sector->page || !sector->uptodate)
2288 return true;
2289 }
2290 return false;
2291}
2292
2293static int rmw_rbio(struct btrfs_raid_bio *rbio)
2294{
2295 struct bio_list bio_list;
2296 int sectornr;
2297 int ret = 0;
2298
2299 /*
2300 * Allocate the pages for parity first, as P/Q pages will always be
2301 * needed for both full-stripe and sub-stripe writes.
2302 */
2303 ret = alloc_rbio_parity_pages(rbio);
2304 if (ret < 0)
2305 return ret;
2306
2307 /*
2308 * Either full stripe write, or we have every data sector already
2309 * cached, can go to write path immediately.
2310 */
2311 if (rbio_is_full(rbio) || !need_read_stripe_sectors(rbio))
2312 goto write;
2313
2314 /*
2315 * Now we're doing sub-stripe write, also need all data stripes to do
2316 * the full RMW.
2317 */
2318 ret = alloc_rbio_data_pages(rbio);
2319 if (ret < 0)
2320 return ret;
2321
2322 index_rbio_pages(rbio);
2323
2324 ret = rmw_read_wait_recover(rbio);
2325 if (ret < 0)
2326 return ret;
2327
2328write:
2329 /*
2330 * At this stage we're not allowed to add any new bios to the
2331 * bio list any more, anyone else that wants to change this stripe
2332 * needs to do their own rmw.
2333 */
2334 spin_lock_irq(&rbio->bio_list_lock);
2335 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
2336 spin_unlock_irq(&rbio->bio_list_lock);
2337
2338 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2339
2340 index_rbio_pages(rbio);
2341
2342 /*
2343 * We don't cache full rbios because we're assuming
2344 * the higher layers are unlikely to use this area of
2345 * the disk again soon. If they do use it again,
2346 * hopefully they will send another full bio.
2347 */
2348 if (!rbio_is_full(rbio))
2349 cache_rbio_pages(rbio);
2350 else
2351 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2352
2353 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
2354 generate_pq_vertical(rbio, sectornr);
2355
2356 bio_list_init(&bio_list);
2357 ret = rmw_assemble_write_bios(rbio, &bio_list);
2358 if (ret < 0)
2359 return ret;
2360
2361 /* We should have at least one bio assembled. */
2362 ASSERT(bio_list_size(&bio_list));
2363 submit_write_bios(rbio, &bio_list);
2364 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2365
2366 /* We may have more errors than our tolerance during the read. */
2367 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
2368 int found_errors;
2369
2370 found_errors = get_rbio_veritical_errors(rbio, sectornr, NULL, NULL);
2371 if (found_errors > rbio->bioc->max_errors) {
2372 ret = -EIO;
2373 break;
2374 }
2375 }
2376 return ret;
2377}
2378
2379static void rmw_rbio_work(struct work_struct *work)
2380{
2381 struct btrfs_raid_bio *rbio;
2382 int ret;
2383
2384 rbio = container_of(work, struct btrfs_raid_bio, work);
2385
2386 ret = lock_stripe_add(rbio);
2387 if (ret == 0) {
2388 ret = rmw_rbio(rbio);
2389 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2390 }
2391}
2392
2393static void rmw_rbio_work_locked(struct work_struct *work)
2394{
2395 struct btrfs_raid_bio *rbio;
2396 int ret;
2397
2398 rbio = container_of(work, struct btrfs_raid_bio, work);
2399
2400 ret = rmw_rbio(rbio);
2401 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2402}
2403
2404/*
2405 * The following code is used to scrub/replace the parity stripe
2406 *
2407 * Caller must have already increased bio_counter for getting @bioc.
2408 *
2409 * Note: We need make sure all the pages that add into the scrub/replace
2410 * raid bio are correct and not be changed during the scrub/replace. That
2411 * is those pages just hold metadata or file data with checksum.
2412 */
2413
2414struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
2415 struct btrfs_io_context *bioc,
2416 struct btrfs_device *scrub_dev,
2417 unsigned long *dbitmap, int stripe_nsectors)
2418{
2419 struct btrfs_fs_info *fs_info = bioc->fs_info;
2420 struct btrfs_raid_bio *rbio;
2421 int i;
2422
2423 rbio = alloc_rbio(fs_info, bioc);
2424 if (IS_ERR(rbio))
2425 return NULL;
2426 bio_list_add(&rbio->bio_list, bio);
2427 /*
2428 * This is a special bio which is used to hold the completion handler
2429 * and make the scrub rbio is similar to the other types
2430 */
2431 ASSERT(!bio->bi_iter.bi_size);
2432 rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
2433
2434 /*
2435 * After mapping bioc with BTRFS_MAP_WRITE, parities have been sorted
2436 * to the end position, so this search can start from the first parity
2437 * stripe.
2438 */
2439 for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
2440 if (bioc->stripes[i].dev == scrub_dev) {
2441 rbio->scrubp = i;
2442 break;
2443 }
2444 }
2445 ASSERT(i < rbio->real_stripes);
2446
2447 bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors);
2448 return rbio;
2449}
2450
2451/* Used for both parity scrub and missing. */
2452void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
2453 unsigned int pgoff, u64 logical)
2454{
2455 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2456 int stripe_offset;
2457 int index;
2458
2459 ASSERT(logical >= rbio->bioc->raid_map[0]);
2460 ASSERT(logical + sectorsize <= rbio->bioc->raid_map[0] +
2461 BTRFS_STRIPE_LEN * rbio->nr_data);
2462 stripe_offset = (int)(logical - rbio->bioc->raid_map[0]);
2463 index = stripe_offset / sectorsize;
2464 rbio->bio_sectors[index].page = page;
2465 rbio->bio_sectors[index].pgoff = pgoff;
2466}
2467
2468/*
2469 * We just scrub the parity that we have correct data on the same horizontal,
2470 * so we needn't allocate all pages for all the stripes.
2471 */
2472static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
2473{
2474 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2475 int total_sector_nr;
2476
2477 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2478 total_sector_nr++) {
2479 struct page *page;
2480 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2481 int index = (total_sector_nr * sectorsize) >> PAGE_SHIFT;
2482
2483 if (!test_bit(sectornr, &rbio->dbitmap))
2484 continue;
2485 if (rbio->stripe_pages[index])
2486 continue;
2487 page = alloc_page(GFP_NOFS);
2488 if (!page)
2489 return -ENOMEM;
2490 rbio->stripe_pages[index] = page;
2491 }
2492 index_stripe_sectors(rbio);
2493 return 0;
2494}
2495
2496static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check)
2497{
2498 struct btrfs_io_context *bioc = rbio->bioc;
2499 const u32 sectorsize = bioc->fs_info->sectorsize;
2500 void **pointers = rbio->finish_pointers;
2501 unsigned long *pbitmap = &rbio->finish_pbitmap;
2502 int nr_data = rbio->nr_data;
2503 int stripe;
2504 int sectornr;
2505 bool has_qstripe;
2506 struct sector_ptr p_sector = { 0 };
2507 struct sector_ptr q_sector = { 0 };
2508 struct bio_list bio_list;
2509 struct bio *bio;
2510 int is_replace = 0;
2511 int ret;
2512
2513 bio_list_init(&bio_list);
2514
2515 if (rbio->real_stripes - rbio->nr_data == 1)
2516 has_qstripe = false;
2517 else if (rbio->real_stripes - rbio->nr_data == 2)
2518 has_qstripe = true;
2519 else
2520 BUG();
2521
2522 if (bioc->num_tgtdevs && bioc->tgtdev_map[rbio->scrubp]) {
2523 is_replace = 1;
2524 bitmap_copy(pbitmap, &rbio->dbitmap, rbio->stripe_nsectors);
2525 }
2526
2527 /*
2528 * Because the higher layers(scrubber) are unlikely to
2529 * use this area of the disk again soon, so don't cache
2530 * it.
2531 */
2532 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2533
2534 if (!need_check)
2535 goto writeback;
2536
2537 p_sector.page = alloc_page(GFP_NOFS);
2538 if (!p_sector.page)
2539 return -ENOMEM;
2540 p_sector.pgoff = 0;
2541 p_sector.uptodate = 1;
2542
2543 if (has_qstripe) {
2544 /* RAID6, allocate and map temp space for the Q stripe */
2545 q_sector.page = alloc_page(GFP_NOFS);
2546 if (!q_sector.page) {
2547 __free_page(p_sector.page);
2548 p_sector.page = NULL;
2549 return -ENOMEM;
2550 }
2551 q_sector.pgoff = 0;
2552 q_sector.uptodate = 1;
2553 pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page);
2554 }
2555
2556 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2557
2558 /* Map the parity stripe just once */
2559 pointers[nr_data] = kmap_local_page(p_sector.page);
2560
2561 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2562 struct sector_ptr *sector;
2563 void *parity;
2564
2565 /* first collect one page from each data stripe */
2566 for (stripe = 0; stripe < nr_data; stripe++) {
2567 sector = sector_in_rbio(rbio, stripe, sectornr, 0);
2568 pointers[stripe] = kmap_local_page(sector->page) +
2569 sector->pgoff;
2570 }
2571
2572 if (has_qstripe) {
2573 /* RAID6, call the library function to fill in our P/Q */
2574 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
2575 pointers);
2576 } else {
2577 /* raid5 */
2578 memcpy(pointers[nr_data], pointers[0], sectorsize);
2579 run_xor(pointers + 1, nr_data - 1, sectorsize);
2580 }
2581
2582 /* Check scrubbing parity and repair it */
2583 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2584 parity = kmap_local_page(sector->page) + sector->pgoff;
2585 if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0)
2586 memcpy(parity, pointers[rbio->scrubp], sectorsize);
2587 else
2588 /* Parity is right, needn't writeback */
2589 bitmap_clear(&rbio->dbitmap, sectornr, 1);
2590 kunmap_local(parity);
2591
2592 for (stripe = nr_data - 1; stripe >= 0; stripe--)
2593 kunmap_local(pointers[stripe]);
2594 }
2595
2596 kunmap_local(pointers[nr_data]);
2597 __free_page(p_sector.page);
2598 p_sector.page = NULL;
2599 if (q_sector.page) {
2600 kunmap_local(pointers[rbio->real_stripes - 1]);
2601 __free_page(q_sector.page);
2602 q_sector.page = NULL;
2603 }
2604
2605writeback:
2606 /*
2607 * time to start writing. Make bios for everything from the
2608 * higher layers (the bio_list in our rbio) and our p/q. Ignore
2609 * everything else.
2610 */
2611 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2612 struct sector_ptr *sector;
2613
2614 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2615 ret = rbio_add_io_sector(rbio, &bio_list, sector, rbio->scrubp,
2616 sectornr, REQ_OP_WRITE);
2617 if (ret)
2618 goto cleanup;
2619 }
2620
2621 if (!is_replace)
2622 goto submit_write;
2623
2624 for_each_set_bit(sectornr, pbitmap, rbio->stripe_nsectors) {
2625 struct sector_ptr *sector;
2626
2627 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2628 ret = rbio_add_io_sector(rbio, &bio_list, sector,
2629 bioc->tgtdev_map[rbio->scrubp],
2630 sectornr, REQ_OP_WRITE);
2631 if (ret)
2632 goto cleanup;
2633 }
2634
2635submit_write:
2636 submit_write_bios(rbio, &bio_list);
2637 return 0;
2638
2639cleanup:
2640 while ((bio = bio_list_pop(&bio_list)))
2641 bio_put(bio);
2642 return ret;
2643}
2644
2645static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
2646{
2647 if (stripe >= 0 && stripe < rbio->nr_data)
2648 return 1;
2649 return 0;
2650}
2651
2652static int recover_scrub_rbio(struct btrfs_raid_bio *rbio)
2653{
2654 void **pointers = NULL;
2655 void **unmap_array = NULL;
2656 int sector_nr;
2657 int ret = 0;
2658
2659 /*
2660 * @pointers array stores the pointer for each sector.
2661 *
2662 * @unmap_array stores copy of pointers that does not get reordered
2663 * during reconstruction so that kunmap_local works.
2664 */
2665 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2666 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2667 if (!pointers || !unmap_array) {
2668 ret = -ENOMEM;
2669 goto out;
2670 }
2671
2672 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2673 int dfail = 0, failp = -1;
2674 int faila;
2675 int failb;
2676 int found_errors;
2677
2678 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2679 &faila, &failb);
2680 if (found_errors > rbio->bioc->max_errors) {
2681 ret = -EIO;
2682 goto out;
2683 }
2684 if (found_errors == 0)
2685 continue;
2686
2687 /* We should have at least one error here. */
2688 ASSERT(faila >= 0 || failb >= 0);
2689
2690 if (is_data_stripe(rbio, faila))
2691 dfail++;
2692 else if (is_parity_stripe(faila))
2693 failp = faila;
2694
2695 if (is_data_stripe(rbio, failb))
2696 dfail++;
2697 else if (is_parity_stripe(failb))
2698 failp = failb;
2699 /*
2700 * Because we can not use a scrubbing parity to repair the
2701 * data, so the capability of the repair is declined. (In the
2702 * case of RAID5, we can not repair anything.)
2703 */
2704 if (dfail > rbio->bioc->max_errors - 1) {
2705 ret = -EIO;
2706 goto out;
2707 }
2708 /*
2709 * If all data is good, only parity is correctly, just repair
2710 * the parity, no need to recover data stripes.
2711 */
2712 if (dfail == 0)
2713 continue;
2714
2715 /*
2716 * Here means we got one corrupted data stripe and one
2717 * corrupted parity on RAID6, if the corrupted parity is
2718 * scrubbing parity, luckily, use the other one to repair the
2719 * data, or we can not repair the data stripe.
2720 */
2721 if (failp != rbio->scrubp) {
2722 ret = -EIO;
2723 goto out;
2724 }
2725
2726 ret = recover_vertical(rbio, sector_nr, pointers, unmap_array);
2727 if (ret < 0)
2728 goto out;
2729 }
2730out:
2731 kfree(pointers);
2732 kfree(unmap_array);
2733 return ret;
2734}
2735
2736static int scrub_assemble_read_bios(struct btrfs_raid_bio *rbio,
2737 struct bio_list *bio_list)
2738{
2739 struct bio *bio;
2740 int total_sector_nr;
2741 int ret = 0;
2742
2743 ASSERT(bio_list_size(bio_list) == 0);
2744
2745 /* Build a list of bios to read all the missing parts. */
2746 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2747 total_sector_nr++) {
2748 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2749 int stripe = total_sector_nr / rbio->stripe_nsectors;
2750 struct sector_ptr *sector;
2751
2752 /* No data in the vertical stripe, no need to read. */
2753 if (!test_bit(sectornr, &rbio->dbitmap))
2754 continue;
2755
2756 /*
2757 * We want to find all the sectors missing from the rbio and
2758 * read them from the disk. If sector_in_rbio() finds a sector
2759 * in the bio list we don't need to read it off the stripe.
2760 */
2761 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
2762 if (sector)
2763 continue;
2764
2765 sector = rbio_stripe_sector(rbio, stripe, sectornr);
2766 /*
2767 * The bio cache may have handed us an uptodate sector. If so,
2768 * use it.
2769 */
2770 if (sector->uptodate)
2771 continue;
2772
2773 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
2774 sectornr, REQ_OP_READ);
2775 if (ret)
2776 goto error;
2777 }
2778 return 0;
2779error:
2780 while ((bio = bio_list_pop(bio_list)))
2781 bio_put(bio);
2782 return ret;
2783}
2784
2785static int scrub_rbio(struct btrfs_raid_bio *rbio)
2786{
2787 bool need_check = false;
2788 struct bio_list bio_list;
2789 int sector_nr;
2790 int ret;
2791 struct bio *bio;
2792
2793 bio_list_init(&bio_list);
2794
2795 ret = alloc_rbio_essential_pages(rbio);
2796 if (ret)
2797 goto cleanup;
2798
2799 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2800
2801 ret = scrub_assemble_read_bios(rbio, &bio_list);
2802 if (ret < 0)
2803 goto cleanup;
2804
2805 submit_read_bios(rbio, &bio_list);
2806 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2807
2808 /* We may have some failures, recover the failed sectors first. */
2809 ret = recover_scrub_rbio(rbio);
2810 if (ret < 0)
2811 goto cleanup;
2812
2813 /*
2814 * We have every sector properly prepared. Can finish the scrub
2815 * and writeback the good content.
2816 */
2817 ret = finish_parity_scrub(rbio, need_check);
2818 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2819 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2820 int found_errors;
2821
2822 found_errors = get_rbio_veritical_errors(rbio, sector_nr, NULL, NULL);
2823 if (found_errors > rbio->bioc->max_errors) {
2824 ret = -EIO;
2825 break;
2826 }
2827 }
2828 return ret;
2829
2830cleanup:
2831 while ((bio = bio_list_pop(&bio_list)))
2832 bio_put(bio);
2833
2834 return ret;
2835}
2836
2837static void scrub_rbio_work_locked(struct work_struct *work)
2838{
2839 struct btrfs_raid_bio *rbio;
2840 int ret;
2841
2842 rbio = container_of(work, struct btrfs_raid_bio, work);
2843 ret = scrub_rbio(rbio);
2844 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2845}
2846
2847void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
2848{
2849 if (!lock_stripe_add(rbio))
2850 start_async_work(rbio, scrub_rbio_work_locked);
2851}
2852
2853/* The following code is used for dev replace of a missing RAID 5/6 device. */
2854
2855struct btrfs_raid_bio *
2856raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc)
2857{
2858 struct btrfs_fs_info *fs_info = bioc->fs_info;
2859 struct btrfs_raid_bio *rbio;
2860
2861 rbio = alloc_rbio(fs_info, bioc);
2862 if (IS_ERR(rbio))
2863 return NULL;
2864
2865 rbio->operation = BTRFS_RBIO_REBUILD_MISSING;
2866 bio_list_add(&rbio->bio_list, bio);
2867 /*
2868 * This is a special bio which is used to hold the completion handler
2869 * and make the scrub rbio is similar to the other types
2870 */
2871 ASSERT(!bio->bi_iter.bi_size);
2872
2873 set_rbio_range_error(rbio, bio);
2874
2875 return rbio;
2876}
2877
2878void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio)
2879{
2880 start_async_work(rbio, recover_rbio_work);
2881}