1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2012 Fusion-io All rights reserved.
4 * Copyright (C) 2012 Intel Corp. All rights reserved.
7 #include <linux/sched.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>
22 #include "async-thread.h"
23 #include "file-item.h"
24 #include "btrfs_inode.h"
26 /* set when additional merges to this rbio are not allowed */
27 #define RBIO_RMW_LOCKED_BIT 1
30 * set when this rbio is sitting in the hash, but it is just a cache
33 #define RBIO_CACHE_BIT 2
36 * set when it is safe to trust the stripe_pages for caching
38 #define RBIO_CACHE_READY_BIT 3
40 #define RBIO_CACHE_SIZE 1024
42 #define BTRFS_STRIPE_HASH_TABLE_BITS 11
44 /* Used by the raid56 code to lock stripes for read/modify/write */
45 struct btrfs_stripe_hash {
46 struct list_head hash_list;
50 /* Used by the raid56 code to lock stripes for read/modify/write */
51 struct btrfs_stripe_hash_table {
52 struct list_head stripe_cache;
53 spinlock_t cache_lock;
55 struct btrfs_stripe_hash table[];
59 * A bvec like structure to present a sector inside a page.
61 * Unlike bvec we don't need bvlen, as it's fixed to sectorsize.
65 unsigned int pgoff:24;
66 unsigned int uptodate:8;
69 static void rmw_rbio_work(struct work_struct *work);
70 static void rmw_rbio_work_locked(struct work_struct *work);
71 static void index_rbio_pages(struct btrfs_raid_bio *rbio);
72 static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
74 static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check);
75 static void scrub_rbio_work_locked(struct work_struct *work);
77 static void free_raid_bio_pointers(struct btrfs_raid_bio *rbio)
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);
86 static void free_raid_bio(struct btrfs_raid_bio *rbio)
90 if (!refcount_dec_and_test(&rbio->refs))
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));
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;
104 btrfs_put_bioc(rbio->bioc);
105 free_raid_bio_pointers(rbio);
109 static void start_async_work(struct btrfs_raid_bio *rbio, work_func_t work_func)
111 INIT_WORK(&rbio->work, work_func);
112 queue_work(rbio->bioc->fs_info->rmw_workers, &rbio->work);
116 * the stripe hash table is used for locking, and to collect
117 * bios in hopes of making a full stripe
119 int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
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;
128 if (info->stripe_hash_table)
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.
135 * Try harder to allocate and fallback to vmalloc to lower the chance
136 * of a failing mount.
138 table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL);
142 spin_lock_init(&table->cache_lock);
143 INIT_LIST_HEAD(&table->stripe_cache);
147 for (i = 0; i < num_entries; i++) {
149 INIT_LIST_HEAD(&cur->hash_list);
150 spin_lock_init(&cur->lock);
153 x = cmpxchg(&info->stripe_hash_table, NULL, table);
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
164 * once the caching is done, we set the cache ready
167 static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
172 ret = alloc_rbio_pages(rbio);
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) {
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
184 if (i < rbio->nr_data * rbio->stripe_nsectors)
185 ASSERT(rbio->stripe_sectors[i].uptodate);
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;
197 set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
201 * we hash on the first logical address of the stripe
203 static int rbio_bucket(struct btrfs_raid_bio *rbio)
205 u64 num = rbio->bioc->raid_map[0];
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.
213 * shifting off the lower bits fixes things.
215 return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
218 static bool full_page_sectors_uptodate(struct btrfs_raid_bio *rbio,
219 unsigned int page_nr)
221 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
222 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
225 ASSERT(page_nr < rbio->nr_pages);
227 for (i = sectors_per_page * page_nr;
228 i < sectors_per_page * page_nr + sectors_per_page;
230 if (!rbio->stripe_sectors[i].uptodate)
237 * Update the stripe_sectors[] array to use correct page and pgoff
239 * Should be called every time any page pointer in stripes_pages[] got modified.
241 static void index_stripe_sectors(struct btrfs_raid_bio *rbio)
243 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
247 for (i = 0, offset = 0; i < rbio->nr_sectors; i++, offset += sectorsize) {
248 int page_index = offset >> PAGE_SHIFT;
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);
256 static void steal_rbio_page(struct btrfs_raid_bio *src,
257 struct btrfs_raid_bio *dest, int page_nr)
259 const u32 sectorsize = src->bioc->fs_info->sectorsize;
260 const u32 sectors_per_page = PAGE_SIZE / sectorsize;
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;
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;
274 static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr)
276 const int sector_nr = (page_nr << PAGE_SHIFT) >>
277 rbio->bioc->fs_info->sectorsize_bits;
280 * We have ensured PAGE_SIZE is aligned with sectorsize, thus
281 * we won't have a page which is half data half parity.
283 * Thus if the first sector of the page belongs to data stripes, then
284 * the full page belongs to data stripes.
286 return (sector_nr < rbio->nr_data * rbio->stripe_nsectors);
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.
293 * This will also update the involved stripe_sectors[] which are referring to
296 static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
300 if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
303 for (i = 0; i < dest->nr_pages; i++) {
304 struct page *p = src->stripe_pages[i];
307 * We don't need to steal P/Q pages as they will always be
308 * regenerated for RMW or full write anyway.
310 if (!is_data_stripe_page(src, i))
314 * If @src already has RBIO_CACHE_READY_BIT, it should have
315 * all data stripe pages present and uptodate.
318 ASSERT(full_page_sectors_uptodate(src, i));
319 steal_rbio_page(src, dest, i);
321 index_stripe_sectors(dest);
322 index_stripe_sectors(src);
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.
330 * must be called with dest->rbio_list_lock held
332 static void merge_rbio(struct btrfs_raid_bio *dest,
333 struct btrfs_raid_bio *victim)
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);
344 * used to prune items that are in the cache. The caller
345 * must hold the hash table lock.
347 static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
349 int bucket = rbio_bucket(rbio);
350 struct btrfs_stripe_hash_table *table;
351 struct btrfs_stripe_hash *h;
355 * check the bit again under the hash table lock.
357 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
360 table = rbio->bioc->fs_info->stripe_hash_table;
361 h = table->table + bucket;
363 /* hold the lock for the bucket because we may be
364 * removing it from the hash table
369 * hold the lock for the bio list because we need
370 * to make sure the bio list is empty
372 spin_lock(&rbio->bio_list_lock);
374 if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
375 list_del_init(&rbio->stripe_cache);
376 table->cache_size -= 1;
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.
384 * If the bio_list was empty, we also remove
385 * the rbio from the hash_table, and drop
386 * the corresponding ref
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));
397 spin_unlock(&rbio->bio_list_lock);
398 spin_unlock(&h->lock);
405 * prune a given rbio from the cache
407 static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
409 struct btrfs_stripe_hash_table *table;
412 if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
415 table = rbio->bioc->fs_info->stripe_hash_table;
417 spin_lock_irqsave(&table->cache_lock, flags);
418 __remove_rbio_from_cache(rbio);
419 spin_unlock_irqrestore(&table->cache_lock, flags);
423 * remove everything in the cache
425 static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
427 struct btrfs_stripe_hash_table *table;
429 struct btrfs_raid_bio *rbio;
431 table = info->stripe_hash_table;
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,
438 __remove_rbio_from_cache(rbio);
440 spin_unlock_irqrestore(&table->cache_lock, flags);
444 * remove all cached entries and free the hash table
447 void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
449 if (!info->stripe_hash_table)
451 btrfs_clear_rbio_cache(info);
452 kvfree(info->stripe_hash_table);
453 info->stripe_hash_table = NULL;
457 * insert an rbio into the stripe cache. It
458 * must have already been prepared by calling
461 * If this rbio was already cached, it gets
462 * moved to the front of the lru.
464 * If the size of the rbio cache is too big, we
467 static void cache_rbio(struct btrfs_raid_bio *rbio)
469 struct btrfs_stripe_hash_table *table;
472 if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
475 table = rbio->bioc->fs_info->stripe_hash_table;
477 spin_lock_irqsave(&table->cache_lock, flags);
478 spin_lock(&rbio->bio_list_lock);
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);
484 if (!list_empty(&rbio->stripe_cache)){
485 list_move(&rbio->stripe_cache, &table->stripe_cache);
487 list_add(&rbio->stripe_cache, &table->stripe_cache);
488 table->cache_size += 1;
491 spin_unlock(&rbio->bio_list_lock);
493 if (table->cache_size > RBIO_CACHE_SIZE) {
494 struct btrfs_raid_bio *found;
496 found = list_entry(table->stripe_cache.prev,
497 struct btrfs_raid_bio,
501 __remove_rbio_from_cache(found);
504 spin_unlock_irqrestore(&table->cache_lock, flags);
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
512 static void run_xor(void **pages, int src_cnt, ssize_t len)
516 void *dest = pages[src_cnt];
519 xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
520 xor_blocks(xor_src_cnt, len, dest, pages + src_off);
522 src_cnt -= xor_src_cnt;
523 src_off += xor_src_cnt;
528 * Returns true if the bio list inside this rbio covers an entire stripe (no
531 static int rbio_is_full(struct btrfs_raid_bio *rbio)
534 unsigned long size = rbio->bio_list_bytes;
537 spin_lock_irqsave(&rbio->bio_list_lock, flags);
538 if (size != rbio->nr_data * BTRFS_STRIPE_LEN)
540 BUG_ON(size > rbio->nr_data * BTRFS_STRIPE_LEN);
541 spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
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
553 * The caller is responsible for locking such that
554 * rmw_locked is safe to test
556 static int rbio_can_merge(struct btrfs_raid_bio *last,
557 struct btrfs_raid_bio *cur)
559 if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
560 test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
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
570 if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
571 test_bit(RBIO_CACHE_BIT, &cur->flags))
574 if (last->bioc->raid_map[0] != cur->bioc->raid_map[0])
577 /* we can't merge with different operations */
578 if (last->operation != cur->operation)
581 * We've need read the full stripe from the drive.
582 * check and repair the parity and write the new results.
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.
588 if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
591 if (last->operation == BTRFS_RBIO_REBUILD_MISSING ||
592 last->operation == BTRFS_RBIO_READ_REBUILD)
598 static unsigned int rbio_stripe_sector_index(const struct btrfs_raid_bio *rbio,
599 unsigned int stripe_nr,
600 unsigned int sector_nr)
602 ASSERT(stripe_nr < rbio->real_stripes);
603 ASSERT(sector_nr < rbio->stripe_nsectors);
605 return stripe_nr * rbio->stripe_nsectors + sector_nr;
608 /* Return a sector from rbio->stripe_sectors, not from the bio list */
609 static struct sector_ptr *rbio_stripe_sector(const struct btrfs_raid_bio *rbio,
610 unsigned int stripe_nr,
611 unsigned int sector_nr)
613 return &rbio->stripe_sectors[rbio_stripe_sector_index(rbio, stripe_nr,
617 /* Grab a sector inside P stripe */
618 static struct sector_ptr *rbio_pstripe_sector(const struct btrfs_raid_bio *rbio,
619 unsigned int sector_nr)
621 return rbio_stripe_sector(rbio, rbio->nr_data, sector_nr);
624 /* Grab a sector inside Q stripe, return NULL if not RAID6 */
625 static struct sector_ptr *rbio_qstripe_sector(const struct btrfs_raid_bio *rbio,
626 unsigned int sector_nr)
628 if (rbio->nr_data + 1 == rbio->real_stripes)
630 return rbio_stripe_sector(rbio, rbio->nr_data + 1, sector_nr);
634 * The first stripe in the table for a logical address
635 * has the lock. rbios are added in one of three ways:
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
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.
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.
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.
655 static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
657 struct btrfs_stripe_hash *h;
658 struct btrfs_raid_bio *cur;
659 struct btrfs_raid_bio *pending;
661 struct btrfs_raid_bio *freeit = NULL;
662 struct btrfs_raid_bio *cache_drop = NULL;
665 h = rbio->bioc->fs_info->stripe_hash_table->table + rbio_bucket(rbio);
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])
672 spin_lock(&cur->bio_list_lock);
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);
682 steal_rbio(cur, rbio);
684 spin_unlock(&cur->bio_list_lock);
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);
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
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);
715 * No merging, put us on the tail of the plug list, our rbio
716 * will be started with the currently running rbio unlocks
718 list_add_tail(&rbio->plug_list, &cur->plug_list);
719 spin_unlock(&cur->bio_list_lock);
724 refcount_inc(&rbio->refs);
725 list_add(&rbio->hash_list, &h->hash_list);
727 spin_unlock_irqrestore(&h->lock, flags);
729 remove_rbio_from_cache(cache_drop);
731 free_raid_bio(freeit);
735 static void recover_rbio_work_locked(struct work_struct *work);
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
741 static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
744 struct btrfs_stripe_hash *h;
748 bucket = rbio_bucket(rbio);
749 h = rbio->bioc->fs_info->stripe_hash_table->table + bucket;
751 if (list_empty(&rbio->plug_list))
754 spin_lock_irqsave(&h->lock, flags);
755 spin_lock(&rbio->bio_list_lock);
757 if (!list_empty(&rbio->hash_list)) {
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
763 if (list_empty(&rbio->plug_list) &&
764 test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
766 clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
767 BUG_ON(!bio_list_empty(&rbio->bio_list));
771 list_del_init(&rbio->hash_list);
772 refcount_dec(&rbio->refs);
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.
779 if (!list_empty(&rbio->plug_list)) {
780 struct btrfs_raid_bio *next;
781 struct list_head *head = rbio->plug_list.next;
783 next = list_entry(head, struct btrfs_raid_bio,
786 list_del_init(&rbio->plug_list);
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);
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);
810 spin_unlock(&rbio->bio_list_lock);
811 spin_unlock_irqrestore(&h->lock, flags);
815 remove_rbio_from_cache(rbio);
818 static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
825 cur->bi_status = err;
832 * this frees the rbio and runs through all the bios in the
833 * bio_list and calls end_io on them
835 static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err)
837 struct bio *cur = bio_list_get(&rbio->bio_list);
840 kfree(rbio->csum_buf);
841 bitmap_free(rbio->csum_bitmap);
842 rbio->csum_buf = NULL;
843 rbio->csum_bitmap = NULL;
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
850 bitmap_clear(&rbio->dbitmap, 0, rbio->stripe_nsectors);
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
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.
861 extra = bio_list_get(&rbio->bio_list);
864 rbio_endio_bio_list(cur, err);
866 rbio_endio_bio_list(extra, err);
870 * Get a sector pointer specified by its @stripe_nr and @sector_nr.
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.
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.
881 static struct sector_ptr *sector_in_rbio(struct btrfs_raid_bio *rbio,
882 int stripe_nr, int sector_nr,
885 struct sector_ptr *sector;
888 ASSERT(stripe_nr >= 0 && stripe_nr < rbio->real_stripes);
889 ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
891 index = stripe_nr * rbio->stripe_nsectors + sector_nr;
892 ASSERT(index >= 0 && index < rbio->nr_sectors);
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 */
900 spin_unlock_irq(&rbio->bio_list_lock);
903 spin_unlock_irq(&rbio->bio_list_lock);
905 return &rbio->stripe_sectors[index];
909 * allocation and initial setup for the btrfs_raid_bio. Not
910 * this does not allocate any pages for rbio->pages.
912 static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
913 struct btrfs_io_context *bioc)
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;
923 /* PAGE_SIZE must also be aligned to sectorsize for subpage support */
924 ASSERT(IS_ALIGNED(PAGE_SIZE, fs_info->sectorsize));
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.
929 ASSERT(stripe_nsectors <= BITS_PER_LONG);
931 rbio = kzalloc(sizeof(*rbio), GFP_NOFS);
933 return ERR_PTR(-ENOMEM);
934 rbio->stripe_pages = kcalloc(num_pages, sizeof(struct page *),
936 rbio->bio_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
938 rbio->stripe_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
940 rbio->finish_pointers = kcalloc(real_stripes, sizeof(void *), GFP_NOFS);
941 rbio->error_bitmap = bitmap_zalloc(num_sectors, GFP_NOFS);
943 if (!rbio->stripe_pages || !rbio->bio_sectors || !rbio->stripe_sectors ||
944 !rbio->finish_pointers || !rbio->error_bitmap) {
945 free_raid_bio_pointers(rbio);
947 return ERR_PTR(-ENOMEM);
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);
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);
966 ASSERT(btrfs_nr_parity_stripes(bioc->map_type));
967 rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type);
972 /* allocate pages for all the stripes in the bio, including parity */
973 static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
977 ret = btrfs_alloc_page_array(rbio->nr_pages, rbio->stripe_pages);
980 /* Mapping all sectors */
981 index_stripe_sectors(rbio);
985 /* only allocate pages for p/q stripes */
986 static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
988 const int data_pages = rbio->nr_data * rbio->stripe_npages;
991 ret = btrfs_alloc_page_array(rbio->nr_pages - data_pages,
992 rbio->stripe_pages + data_pages);
996 index_stripe_sectors(rbio);
1001 * Return the total numer of errors found in the vertical stripe of @sector_nr.
1003 * @faila and @failb will also be updated to the first and second stripe
1004 * number of the errors.
1006 static int get_rbio_veritical_errors(struct btrfs_raid_bio *rbio, int sector_nr,
1007 int *faila, int *failb)
1010 int found_errors = 0;
1012 if (faila || failb) {
1014 * Both @faila and @failb should be valid pointers if any of
1015 * them is specified.
1017 ASSERT(faila && failb);
1022 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1023 int total_sector_nr = stripe_nr * rbio->stripe_nsectors + sector_nr;
1025 if (test_bit(total_sector_nr, rbio->error_bitmap)) {
1028 /* Update faila and failb. */
1031 else if (*failb < 0)
1036 return found_errors;
1040 * Add a single sector @sector into our list of bios for IO.
1042 * Return 0 if everything went well.
1043 * Return <0 for error.
1045 static 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,
1052 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1053 struct bio *last = bio_list->tail;
1056 struct btrfs_io_stripe *stripe;
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.
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);
1068 stripe = &rbio->bioc->stripes[stripe_nr];
1069 disk_start = stripe->physical + sector_nr * sectorsize;
1071 /* if the device is missing, just fail this stripe */
1072 if (!stripe->dev->bdev) {
1075 set_bit(stripe_nr * rbio->stripe_nsectors + sector_nr,
1076 rbio->error_bitmap);
1078 /* Check if we have reached tolerance early. */
1079 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
1081 if (found_errors > rbio->bioc->max_errors)
1086 /* see if we can add this page onto our existing bio */
1088 u64 last_end = last->bi_iter.bi_sector << 9;
1089 last_end += last->bi_iter.bi_size;
1092 * we can't merge these if they are from different
1093 * devices or if they are not contiguous
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,
1099 if (ret == sectorsize)
1104 /* put a new bio on the list */
1105 bio = bio_alloc(stripe->dev->bdev,
1106 max(BTRFS_STRIPE_LEN >> PAGE_SHIFT, 1),
1108 bio->bi_iter.bi_sector = disk_start >> 9;
1109 bio->bi_private = rbio;
1111 bio_add_page(bio, sector->page, sectorsize, sector->pgoff);
1112 bio_list_add(bio_list, bio);
1116 static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)
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];
1124 bio_for_each_segment(bvec, bio, iter) {
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];
1132 sector->page = bvec.bv_page;
1133 sector->pgoff = bvec.bv_offset + bvec_offset;
1134 ASSERT(sector->pgoff < PAGE_SIZE);
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
1145 * This must be called before you trust the answers from page_in_rbio
1147 static void index_rbio_pages(struct btrfs_raid_bio *rbio)
1151 spin_lock_irq(&rbio->bio_list_lock);
1152 bio_list_for_each(bio, &rbio->bio_list)
1153 index_one_bio(rbio, bio);
1155 spin_unlock_irq(&rbio->bio_list_lock);
1158 static void bio_get_trace_info(struct btrfs_raid_bio *rbio, struct bio *bio,
1159 struct raid56_bio_trace_info *trace_info)
1161 const struct btrfs_io_context *bioc = rbio->bioc;
1166 /* We rely on bio->bi_bdev to find the stripe number. */
1170 for (i = 0; i < bioc->num_stripes; i++) {
1171 if (bio->bi_bdev != bioc->stripes[i].dev->bdev)
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;
1181 trace_info->devid = -1;
1182 trace_info->offset = -1;
1183 trace_info->stripe_nr = -1;
1186 /* Generate PQ for one veritical stripe. */
1187 static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr)
1189 void **pointers = rbio->finish_pointers;
1190 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1191 struct sector_ptr *sector;
1193 const bool has_qstripe = rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6;
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) +
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;
1209 * RAID6, add the qstripe and call the library function
1210 * to fill in our p/q
1212 sector = rbio_qstripe_sector(rbio, sectornr);
1213 sector->uptodate = 1;
1214 pointers[stripe++] = kmap_local_page(sector->page) +
1217 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
1221 memcpy(pointers[rbio->nr_data], pointers[0], sectorsize);
1222 run_xor(pointers + 1, rbio->nr_data - 1, sectorsize);
1224 for (stripe = stripe - 1; stripe >= 0; stripe--)
1225 kunmap_local(pointers[stripe]);
1228 static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio,
1229 struct bio_list *bio_list)
1232 /* The total sector number inside the full stripe. */
1233 int total_sector_nr;
1238 ASSERT(bio_list_size(bio_list) == 0);
1240 /* We should have at least one data sector. */
1241 ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));
1244 * Reset errors, as we may have errors inherited from from degraded
1247 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
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.
1253 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1254 total_sector_nr++) {
1255 struct sector_ptr *sector;
1257 stripe = total_sector_nr / rbio->stripe_nsectors;
1258 sectornr = total_sector_nr % rbio->stripe_nsectors;
1260 /* This vertical stripe has no data, skip it. */
1261 if (!test_bit(sectornr, &rbio->dbitmap))
1264 if (stripe < rbio->nr_data) {
1265 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1269 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1272 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
1273 sectornr, REQ_OP_WRITE);
1278 if (likely(!rbio->bioc->num_tgtdevs))
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;
1286 stripe = total_sector_nr / rbio->stripe_nsectors;
1287 sectornr = total_sector_nr % rbio->stripe_nsectors;
1289 if (!rbio->bioc->tgtdev_map[stripe]) {
1291 * We can skip the whole stripe completely, note
1292 * total_sector_nr will be increased by one anyway.
1294 ASSERT(sectornr == 0);
1295 total_sector_nr += rbio->stripe_nsectors - 1;
1299 /* This vertical stripe has no data, skip it. */
1300 if (!test_bit(sectornr, &rbio->dbitmap))
1303 if (stripe < rbio->nr_data) {
1304 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
1308 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1311 ret = rbio_add_io_sector(rbio, bio_list, sector,
1312 rbio->bioc->tgtdev_map[stripe],
1313 sectornr, REQ_OP_WRITE);
1320 while ((bio = bio_list_pop(bio_list)))
1325 static void set_rbio_range_error(struct btrfs_raid_bio *rbio, struct bio *bio)
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;
1332 ASSERT(total_nr_sector < rbio->nr_data * rbio->stripe_nsectors);
1334 bitmap_set(rbio->error_bitmap, total_nr_sector,
1335 bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
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.
1343 if (bio->bi_iter.bi_size == 0) {
1344 bool found_missing = false;
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);
1355 ASSERT(found_missing);
1360 * For subpage case, we can no longer set page Uptodate directly for
1361 * stripe_pages[], thus we need to locate the sector.
1363 static struct sector_ptr *find_stripe_sector(struct btrfs_raid_bio *rbio,
1369 for (i = 0; i < rbio->nr_sectors; i++) {
1370 struct sector_ptr *sector = &rbio->stripe_sectors[i];
1372 if (sector->page == page && sector->pgoff == pgoff)
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
1382 static void set_bio_pages_uptodate(struct btrfs_raid_bio *rbio, struct bio *bio)
1384 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
1385 struct bio_vec *bvec;
1386 struct bvec_iter_all iter_all;
1388 ASSERT(!bio_flagged(bio, BIO_CLONED));
1390 bio_for_each_segment_all(bvec, bio, iter_all) {
1391 struct sector_ptr *sector;
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);
1399 sector->uptodate = 1;
1404 static int get_bio_sector_nr(struct btrfs_raid_bio *rbio, struct bio *bio)
1406 struct bio_vec *bv = bio_first_bvec_all(bio);
1409 for (i = 0; i < rbio->nr_sectors; i++) {
1410 struct sector_ptr *sector;
1412 sector = &rbio->stripe_sectors[i];
1413 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1415 sector = &rbio->bio_sectors[i];
1416 if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
1419 ASSERT(i < rbio->nr_sectors);
1423 static void rbio_update_error_bitmap(struct btrfs_raid_bio *rbio, struct bio *bio)
1425 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1427 struct bio_vec *bvec;
1428 struct bvec_iter_all iter_all;
1430 bio_for_each_segment_all(bvec, bio, iter_all)
1431 bio_size += bvec->bv_len;
1433 bitmap_set(rbio->error_bitmap, total_sector_nr,
1434 bio_size >> rbio->bioc->fs_info->sectorsize_bits);
1437 /* Verify the data sectors at read time. */
1438 static void verify_bio_data_sectors(struct btrfs_raid_bio *rbio,
1441 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1442 int total_sector_nr = get_bio_sector_nr(rbio, bio);
1443 struct bio_vec *bvec;
1444 struct bvec_iter_all iter_all;
1446 /* No data csum for the whole stripe, no need to verify. */
1447 if (!rbio->csum_bitmap || !rbio->csum_buf)
1450 /* P/Q stripes, they have no data csum to verify against. */
1451 if (total_sector_nr >= rbio->nr_data * rbio->stripe_nsectors)
1454 bio_for_each_segment_all(bvec, bio, iter_all) {
1457 for (bv_offset = bvec->bv_offset;
1458 bv_offset < bvec->bv_offset + bvec->bv_len;
1459 bv_offset += fs_info->sectorsize, total_sector_nr++) {
1460 u8 csum_buf[BTRFS_CSUM_SIZE];
1461 u8 *expected_csum = rbio->csum_buf +
1462 total_sector_nr * fs_info->csum_size;
1465 /* No csum for this sector, skip to the next sector. */
1466 if (!test_bit(total_sector_nr, rbio->csum_bitmap))
1469 ret = btrfs_check_sector_csum(fs_info, bvec->bv_page,
1470 bv_offset, csum_buf, expected_csum);
1472 set_bit(total_sector_nr, rbio->error_bitmap);
1477 static void raid_wait_read_end_io(struct bio *bio)
1479 struct btrfs_raid_bio *rbio = bio->bi_private;
1481 if (bio->bi_status) {
1482 rbio_update_error_bitmap(rbio, bio);
1484 set_bio_pages_uptodate(rbio, bio);
1485 verify_bio_data_sectors(rbio, bio);
1489 if (atomic_dec_and_test(&rbio->stripes_pending))
1490 wake_up(&rbio->io_wait);
1493 static void submit_read_bios(struct btrfs_raid_bio *rbio,
1494 struct bio_list *bio_list)
1498 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
1499 while ((bio = bio_list_pop(bio_list))) {
1500 bio->bi_end_io = raid_wait_read_end_io;
1502 if (trace_raid56_scrub_read_recover_enabled()) {
1503 struct raid56_bio_trace_info trace_info = { 0 };
1505 bio_get_trace_info(rbio, bio, &trace_info);
1506 trace_raid56_scrub_read_recover(rbio, bio, &trace_info);
1512 static int rmw_assemble_read_bios(struct btrfs_raid_bio *rbio,
1513 struct bio_list *bio_list)
1516 int total_sector_nr;
1519 ASSERT(bio_list_size(bio_list) == 0);
1522 * Build a list of bios to read all sectors (including data and P/Q).
1524 * This behaviro is to compensate the later csum verification and
1527 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1528 total_sector_nr++) {
1529 struct sector_ptr *sector;
1530 int stripe = total_sector_nr / rbio->stripe_nsectors;
1531 int sectornr = total_sector_nr % rbio->stripe_nsectors;
1533 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1534 ret = rbio_add_io_sector(rbio, bio_list, sector,
1535 stripe, sectornr, REQ_OP_READ);
1542 while ((bio = bio_list_pop(bio_list)))
1547 static int alloc_rbio_data_pages(struct btrfs_raid_bio *rbio)
1549 const int data_pages = rbio->nr_data * rbio->stripe_npages;
1552 ret = btrfs_alloc_page_array(data_pages, rbio->stripe_pages);
1556 index_stripe_sectors(rbio);
1561 * We use plugging call backs to collect full stripes.
1562 * Any time we get a partial stripe write while plugged
1563 * we collect it into a list. When the unplug comes down,
1564 * we sort the list by logical block number and merge
1565 * everything we can into the same rbios
1567 struct btrfs_plug_cb {
1568 struct blk_plug_cb cb;
1569 struct btrfs_fs_info *info;
1570 struct list_head rbio_list;
1571 struct work_struct work;
1575 * rbios on the plug list are sorted for easier merging.
1577 static int plug_cmp(void *priv, const struct list_head *a,
1578 const struct list_head *b)
1580 const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
1582 const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
1584 u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
1585 u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
1587 if (a_sector < b_sector)
1589 if (a_sector > b_sector)
1594 static void raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
1596 struct btrfs_plug_cb *plug = container_of(cb, struct btrfs_plug_cb, cb);
1597 struct btrfs_raid_bio *cur;
1598 struct btrfs_raid_bio *last = NULL;
1600 list_sort(NULL, &plug->rbio_list, plug_cmp);
1602 while (!list_empty(&plug->rbio_list)) {
1603 cur = list_entry(plug->rbio_list.next,
1604 struct btrfs_raid_bio, plug_list);
1605 list_del_init(&cur->plug_list);
1607 if (rbio_is_full(cur)) {
1608 /* We have a full stripe, queue it down. */
1609 start_async_work(cur, rmw_rbio_work);
1613 if (rbio_can_merge(last, cur)) {
1614 merge_rbio(last, cur);
1618 start_async_work(last, rmw_rbio_work);
1623 start_async_work(last, rmw_rbio_work);
1627 /* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */
1628 static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio)
1630 const struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1631 const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT;
1632 const u64 full_stripe_start = rbio->bioc->raid_map[0];
1633 const u32 orig_len = orig_bio->bi_iter.bi_size;
1634 const u32 sectorsize = fs_info->sectorsize;
1637 ASSERT(orig_logical >= full_stripe_start &&
1638 orig_logical + orig_len <= full_stripe_start +
1639 rbio->nr_data * BTRFS_STRIPE_LEN);
1641 bio_list_add(&rbio->bio_list, orig_bio);
1642 rbio->bio_list_bytes += orig_bio->bi_iter.bi_size;
1644 /* Update the dbitmap. */
1645 for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len;
1646 cur_logical += sectorsize) {
1647 int bit = ((u32)(cur_logical - full_stripe_start) >>
1648 fs_info->sectorsize_bits) % rbio->stripe_nsectors;
1650 set_bit(bit, &rbio->dbitmap);
1655 * our main entry point for writes from the rest of the FS.
1657 void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
1659 struct btrfs_fs_info *fs_info = bioc->fs_info;
1660 struct btrfs_raid_bio *rbio;
1661 struct btrfs_plug_cb *plug = NULL;
1662 struct blk_plug_cb *cb;
1665 rbio = alloc_rbio(fs_info, bioc);
1667 ret = PTR_ERR(rbio);
1670 rbio->operation = BTRFS_RBIO_WRITE;
1671 rbio_add_bio(rbio, bio);
1674 * Don't plug on full rbios, just get them out the door
1675 * as quickly as we can
1677 if (rbio_is_full(rbio))
1680 cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
1682 plug = container_of(cb, struct btrfs_plug_cb, cb);
1684 plug->info = fs_info;
1685 INIT_LIST_HEAD(&plug->rbio_list);
1687 list_add_tail(&rbio->plug_list, &plug->rbio_list);
1692 * Either we don't have any existing plug, or we're doing a full stripe,
1693 * can queue the rmw work now.
1695 start_async_work(rbio, rmw_rbio_work);
1700 bio->bi_status = errno_to_blk_status(ret);
1704 static int verify_one_sector(struct btrfs_raid_bio *rbio,
1705 int stripe_nr, int sector_nr)
1707 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1708 struct sector_ptr *sector;
1709 u8 csum_buf[BTRFS_CSUM_SIZE];
1713 if (!rbio->csum_bitmap || !rbio->csum_buf)
1716 /* No way to verify P/Q as they are not covered by data csum. */
1717 if (stripe_nr >= rbio->nr_data)
1720 * If we're rebuilding a read, we have to use pages from the
1721 * bio list if possible.
1723 if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1724 rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) {
1725 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1727 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1730 ASSERT(sector->page);
1732 csum_expected = rbio->csum_buf +
1733 (stripe_nr * rbio->stripe_nsectors + sector_nr) *
1735 ret = btrfs_check_sector_csum(fs_info, sector->page, sector->pgoff,
1736 csum_buf, csum_expected);
1741 * Recover a vertical stripe specified by @sector_nr.
1742 * @*pointers are the pre-allocated pointers by the caller, so we don't
1743 * need to allocate/free the pointers again and again.
1745 static int recover_vertical(struct btrfs_raid_bio *rbio, int sector_nr,
1746 void **pointers, void **unmap_array)
1748 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
1749 struct sector_ptr *sector;
1750 const u32 sectorsize = fs_info->sectorsize;
1758 * Now we just use bitmap to mark the horizontal stripes in
1759 * which we have data when doing parity scrub.
1761 if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
1762 !test_bit(sector_nr, &rbio->dbitmap))
1765 found_errors = get_rbio_veritical_errors(rbio, sector_nr, &faila,
1768 * No errors in the veritical stripe, skip it. Can happen for recovery
1769 * which only part of a stripe failed csum check.
1774 if (found_errors > rbio->bioc->max_errors)
1778 * Setup our array of pointers with sectors from each stripe
1780 * NOTE: store a duplicate array of pointers to preserve the
1783 for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
1785 * If we're rebuilding a read, we have to use pages from the
1786 * bio list if possible.
1788 if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1789 rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) {
1790 sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
1792 sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
1794 ASSERT(sector->page);
1795 pointers[stripe_nr] = kmap_local_page(sector->page) +
1797 unmap_array[stripe_nr] = pointers[stripe_nr];
1800 /* All raid6 handling here */
1801 if (rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6) {
1802 /* Single failure, rebuild from parity raid5 style */
1804 if (faila == rbio->nr_data)
1806 * Just the P stripe has failed, without
1807 * a bad data or Q stripe.
1808 * We have nothing to do, just skip the
1809 * recovery for this stripe.
1813 * a single failure in raid6 is rebuilt
1814 * in the pstripe code below
1820 * If the q stripe is failed, do a pstripe reconstruction from
1822 * If both the q stripe and the P stripe are failed, we're
1823 * here due to a crc mismatch and we can't give them the
1826 if (rbio->bioc->raid_map[failb] == RAID6_Q_STRIPE) {
1827 if (rbio->bioc->raid_map[faila] ==
1830 * Only P and Q are corrupted.
1831 * We only care about data stripes recovery,
1832 * can skip this vertical stripe.
1836 * Otherwise we have one bad data stripe and
1837 * a good P stripe. raid5!
1842 if (rbio->bioc->raid_map[failb] == RAID5_P_STRIPE) {
1843 raid6_datap_recov(rbio->real_stripes, sectorsize,
1846 raid6_2data_recov(rbio->real_stripes, sectorsize,
1847 faila, failb, pointers);
1852 /* Rebuild from P stripe here (raid5 or raid6). */
1853 ASSERT(failb == -1);
1855 /* Copy parity block into failed block to start with */
1856 memcpy(pointers[faila], pointers[rbio->nr_data], sectorsize);
1858 /* Rearrange the pointer array */
1859 p = pointers[faila];
1860 for (stripe_nr = faila; stripe_nr < rbio->nr_data - 1;
1862 pointers[stripe_nr] = pointers[stripe_nr + 1];
1863 pointers[rbio->nr_data - 1] = p;
1865 /* Xor in the rest */
1866 run_xor(pointers, rbio->nr_data - 1, sectorsize);
1871 * No matter if this is a RMW or recovery, we should have all
1872 * failed sectors repaired in the vertical stripe, thus they are now
1874 * Especially if we determine to cache the rbio, we need to
1875 * have at least all data sectors uptodate.
1877 * If possible, also check if the repaired sector matches its data
1881 ret = verify_one_sector(rbio, faila, sector_nr);
1885 sector = rbio_stripe_sector(rbio, faila, sector_nr);
1886 sector->uptodate = 1;
1889 ret = verify_one_sector(rbio, faila, sector_nr);
1893 sector = rbio_stripe_sector(rbio, failb, sector_nr);
1894 sector->uptodate = 1;
1898 for (stripe_nr = rbio->real_stripes - 1; stripe_nr >= 0; stripe_nr--)
1899 kunmap_local(unmap_array[stripe_nr]);
1903 static int recover_sectors(struct btrfs_raid_bio *rbio)
1905 void **pointers = NULL;
1906 void **unmap_array = NULL;
1911 * @pointers array stores the pointer for each sector.
1913 * @unmap_array stores copy of pointers that does not get reordered
1914 * during reconstruction so that kunmap_local works.
1916 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1917 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
1918 if (!pointers || !unmap_array) {
1923 if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
1924 rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
1925 spin_lock_irq(&rbio->bio_list_lock);
1926 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
1927 spin_unlock_irq(&rbio->bio_list_lock);
1930 index_rbio_pages(rbio);
1932 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
1933 ret = recover_vertical(rbio, sectornr, pointers, unmap_array);
1944 static int recover_assemble_read_bios(struct btrfs_raid_bio *rbio,
1945 struct bio_list *bio_list)
1948 int total_sector_nr;
1951 ASSERT(bio_list_size(bio_list) == 0);
1953 * Read everything that hasn't failed. However this time we will
1954 * not trust any cached sector.
1955 * As we may read out some stale data but higher layer is not reading
1958 * So here we always re-read everything in recovery path.
1960 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
1961 total_sector_nr++) {
1962 int stripe = total_sector_nr / rbio->stripe_nsectors;
1963 int sectornr = total_sector_nr % rbio->stripe_nsectors;
1964 struct sector_ptr *sector;
1967 * Skip the range which has error. It can be a range which is
1968 * marked error (for csum mismatch), or it can be a missing
1971 if (!rbio->bioc->stripes[stripe].dev->bdev ||
1972 test_bit(total_sector_nr, rbio->error_bitmap)) {
1974 * Also set the error bit for missing device, which
1975 * may not yet have its error bit set.
1977 set_bit(total_sector_nr, rbio->error_bitmap);
1981 sector = rbio_stripe_sector(rbio, stripe, sectornr);
1982 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
1983 sectornr, REQ_OP_READ);
1989 while ((bio = bio_list_pop(bio_list)))
1995 static int recover_rbio(struct btrfs_raid_bio *rbio)
1997 struct bio_list bio_list;
2002 * Either we're doing recover for a read failure or degraded write,
2003 * caller should have set error bitmap correctly.
2005 ASSERT(bitmap_weight(rbio->error_bitmap, rbio->nr_sectors));
2006 bio_list_init(&bio_list);
2008 /* For recovery, we need to read all sectors including P/Q. */
2009 ret = alloc_rbio_pages(rbio);
2013 index_rbio_pages(rbio);
2015 ret = recover_assemble_read_bios(rbio, &bio_list);
2019 submit_read_bios(rbio, &bio_list);
2020 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2022 ret = recover_sectors(rbio);
2025 while ((bio = bio_list_pop(&bio_list)))
2031 static void recover_rbio_work(struct work_struct *work)
2033 struct btrfs_raid_bio *rbio;
2036 rbio = container_of(work, struct btrfs_raid_bio, work);
2038 ret = lock_stripe_add(rbio);
2040 ret = recover_rbio(rbio);
2041 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2045 static void recover_rbio_work_locked(struct work_struct *work)
2047 struct btrfs_raid_bio *rbio;
2050 rbio = container_of(work, struct btrfs_raid_bio, work);
2052 ret = recover_rbio(rbio);
2053 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2056 static void set_rbio_raid6_extra_error(struct btrfs_raid_bio *rbio, int mirror_num)
2062 * This is for RAID6 extra recovery tries, thus mirror number should
2064 * Mirror 1 means read from data stripes. Mirror 2 means rebuild using
2067 ASSERT(mirror_num > 2);
2068 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2073 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2075 /* This vertical stripe doesn't have errors. */
2080 * If we found errors, there should be only one error marked
2081 * by previous set_rbio_range_error().
2083 ASSERT(found_errors == 1);
2086 /* Now select another stripe to mark as error. */
2087 failb = rbio->real_stripes - (mirror_num - 1);
2091 /* Set the extra bit in error bitmap. */
2093 set_bit(failb * rbio->stripe_nsectors + sector_nr,
2094 rbio->error_bitmap);
2097 /* We should found at least one vertical stripe with error.*/
2102 * the main entry point for reads from the higher layers. This
2103 * is really only called when the normal read path had a failure,
2104 * so we assume the bio they send down corresponds to a failed part
2107 void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
2110 struct btrfs_fs_info *fs_info = bioc->fs_info;
2111 struct btrfs_raid_bio *rbio;
2113 rbio = alloc_rbio(fs_info, bioc);
2115 bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
2120 rbio->operation = BTRFS_RBIO_READ_REBUILD;
2121 rbio_add_bio(rbio, bio);
2123 set_rbio_range_error(rbio, bio);
2127 * for 'mirror == 2', reconstruct from all other stripes.
2128 * for 'mirror_num > 2', select a stripe to fail on every retry.
2131 set_rbio_raid6_extra_error(rbio, mirror_num);
2133 start_async_work(rbio, recover_rbio_work);
2136 static void fill_data_csums(struct btrfs_raid_bio *rbio)
2138 struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
2139 struct btrfs_root *csum_root = btrfs_csum_root(fs_info,
2140 rbio->bioc->raid_map[0]);
2141 const u64 start = rbio->bioc->raid_map[0];
2142 const u32 len = (rbio->nr_data * rbio->stripe_nsectors) <<
2143 fs_info->sectorsize_bits;
2146 /* The rbio should not have its csum buffer initialized. */
2147 ASSERT(!rbio->csum_buf && !rbio->csum_bitmap);
2150 * Skip the csum search if:
2152 * - The rbio doesn't belong to data block groups
2153 * Then we are doing IO for tree blocks, no need to search csums.
2155 * - The rbio belongs to mixed block groups
2156 * This is to avoid deadlock, as we're already holding the full
2157 * stripe lock, if we trigger a metadata read, and it needs to do
2158 * raid56 recovery, we will deadlock.
2160 if (!(rbio->bioc->map_type & BTRFS_BLOCK_GROUP_DATA) ||
2161 rbio->bioc->map_type & BTRFS_BLOCK_GROUP_METADATA)
2164 rbio->csum_buf = kzalloc(rbio->nr_data * rbio->stripe_nsectors *
2165 fs_info->csum_size, GFP_NOFS);
2166 rbio->csum_bitmap = bitmap_zalloc(rbio->nr_data * rbio->stripe_nsectors,
2168 if (!rbio->csum_buf || !rbio->csum_bitmap) {
2173 ret = btrfs_lookup_csums_bitmap(csum_root, start, start + len - 1,
2174 rbio->csum_buf, rbio->csum_bitmap);
2177 if (bitmap_empty(rbio->csum_bitmap, len >> fs_info->sectorsize_bits))
2183 * We failed to allocate memory or grab the csum, but it's not fatal,
2184 * we can still continue. But better to warn users that RMW is no
2185 * longer safe for this particular sub-stripe write.
2187 btrfs_warn_rl(fs_info,
2188 "sub-stripe write for full stripe %llu is not safe, failed to get csum: %d",
2189 rbio->bioc->raid_map[0], ret);
2191 kfree(rbio->csum_buf);
2192 bitmap_free(rbio->csum_bitmap);
2193 rbio->csum_buf = NULL;
2194 rbio->csum_bitmap = NULL;
2197 static int rmw_read_wait_recover(struct btrfs_raid_bio *rbio)
2199 struct bio_list bio_list;
2203 bio_list_init(&bio_list);
2206 * Fill the data csums we need for data verification. We need to fill
2207 * the csum_bitmap/csum_buf first, as our endio function will try to
2208 * verify the data sectors.
2210 fill_data_csums(rbio);
2212 ret = rmw_assemble_read_bios(rbio, &bio_list);
2216 submit_read_bios(rbio, &bio_list);
2217 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2220 * We may or may not have any corrupted sectors (including missing dev
2221 * and csum mismatch), just let recover_sectors() to handle them all.
2223 ret = recover_sectors(rbio);
2226 while ((bio = bio_list_pop(&bio_list)))
2232 static void raid_wait_write_end_io(struct bio *bio)
2234 struct btrfs_raid_bio *rbio = bio->bi_private;
2235 blk_status_t err = bio->bi_status;
2238 rbio_update_error_bitmap(rbio, bio);
2240 if (atomic_dec_and_test(&rbio->stripes_pending))
2241 wake_up(&rbio->io_wait);
2244 static void submit_write_bios(struct btrfs_raid_bio *rbio,
2245 struct bio_list *bio_list)
2249 atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
2250 while ((bio = bio_list_pop(bio_list))) {
2251 bio->bi_end_io = raid_wait_write_end_io;
2253 if (trace_raid56_write_stripe_enabled()) {
2254 struct raid56_bio_trace_info trace_info = { 0 };
2256 bio_get_trace_info(rbio, bio, &trace_info);
2257 trace_raid56_write_stripe(rbio, bio, &trace_info);
2264 * To determine if we need to read any sector from the disk.
2265 * Should only be utilized in RMW path, to skip cached rbio.
2267 static bool need_read_stripe_sectors(struct btrfs_raid_bio *rbio)
2271 for (i = 0; i < rbio->nr_data * rbio->stripe_nsectors; i++) {
2272 struct sector_ptr *sector = &rbio->stripe_sectors[i];
2275 * We have a sector which doesn't have page nor uptodate,
2276 * thus this rbio can not be cached one, as cached one must
2277 * have all its data sectors present and uptodate.
2279 if (!sector->page || !sector->uptodate)
2285 static int rmw_rbio(struct btrfs_raid_bio *rbio)
2287 struct bio_list bio_list;
2292 * Allocate the pages for parity first, as P/Q pages will always be
2293 * needed for both full-stripe and sub-stripe writes.
2295 ret = alloc_rbio_parity_pages(rbio);
2300 * Either full stripe write, or we have every data sector already
2301 * cached, can go to write path immediately.
2303 if (rbio_is_full(rbio) || !need_read_stripe_sectors(rbio))
2307 * Now we're doing sub-stripe write, also need all data stripes to do
2310 ret = alloc_rbio_data_pages(rbio);
2314 index_rbio_pages(rbio);
2316 ret = rmw_read_wait_recover(rbio);
2322 * At this stage we're not allowed to add any new bios to the
2323 * bio list any more, anyone else that wants to change this stripe
2324 * needs to do their own rmw.
2326 spin_lock_irq(&rbio->bio_list_lock);
2327 set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
2328 spin_unlock_irq(&rbio->bio_list_lock);
2330 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2332 index_rbio_pages(rbio);
2335 * We don't cache full rbios because we're assuming
2336 * the higher layers are unlikely to use this area of
2337 * the disk again soon. If they do use it again,
2338 * hopefully they will send another full bio.
2340 if (!rbio_is_full(rbio))
2341 cache_rbio_pages(rbio);
2343 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2345 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
2346 generate_pq_vertical(rbio, sectornr);
2348 bio_list_init(&bio_list);
2349 ret = rmw_assemble_write_bios(rbio, &bio_list);
2353 /* We should have at least one bio assembled. */
2354 ASSERT(bio_list_size(&bio_list));
2355 submit_write_bios(rbio, &bio_list);
2356 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2358 /* We may have more errors than our tolerance during the read. */
2359 for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
2362 found_errors = get_rbio_veritical_errors(rbio, sectornr, NULL, NULL);
2363 if (found_errors > rbio->bioc->max_errors) {
2371 static void rmw_rbio_work(struct work_struct *work)
2373 struct btrfs_raid_bio *rbio;
2376 rbio = container_of(work, struct btrfs_raid_bio, work);
2378 ret = lock_stripe_add(rbio);
2380 ret = rmw_rbio(rbio);
2381 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2385 static void rmw_rbio_work_locked(struct work_struct *work)
2387 struct btrfs_raid_bio *rbio;
2390 rbio = container_of(work, struct btrfs_raid_bio, work);
2392 ret = rmw_rbio(rbio);
2393 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2397 * The following code is used to scrub/replace the parity stripe
2399 * Caller must have already increased bio_counter for getting @bioc.
2401 * Note: We need make sure all the pages that add into the scrub/replace
2402 * raid bio are correct and not be changed during the scrub/replace. That
2403 * is those pages just hold metadata or file data with checksum.
2406 struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
2407 struct btrfs_io_context *bioc,
2408 struct btrfs_device *scrub_dev,
2409 unsigned long *dbitmap, int stripe_nsectors)
2411 struct btrfs_fs_info *fs_info = bioc->fs_info;
2412 struct btrfs_raid_bio *rbio;
2415 rbio = alloc_rbio(fs_info, bioc);
2418 bio_list_add(&rbio->bio_list, bio);
2420 * This is a special bio which is used to hold the completion handler
2421 * and make the scrub rbio is similar to the other types
2423 ASSERT(!bio->bi_iter.bi_size);
2424 rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
2427 * After mapping bioc with BTRFS_MAP_WRITE, parities have been sorted
2428 * to the end position, so this search can start from the first parity
2431 for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
2432 if (bioc->stripes[i].dev == scrub_dev) {
2437 ASSERT(i < rbio->real_stripes);
2439 bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors);
2443 /* Used for both parity scrub and missing. */
2444 void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
2445 unsigned int pgoff, u64 logical)
2447 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2451 ASSERT(logical >= rbio->bioc->raid_map[0]);
2452 ASSERT(logical + sectorsize <= rbio->bioc->raid_map[0] +
2453 BTRFS_STRIPE_LEN * rbio->nr_data);
2454 stripe_offset = (int)(logical - rbio->bioc->raid_map[0]);
2455 index = stripe_offset / sectorsize;
2456 rbio->bio_sectors[index].page = page;
2457 rbio->bio_sectors[index].pgoff = pgoff;
2461 * We just scrub the parity that we have correct data on the same horizontal,
2462 * so we needn't allocate all pages for all the stripes.
2464 static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
2466 const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
2467 int total_sector_nr;
2469 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2470 total_sector_nr++) {
2472 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2473 int index = (total_sector_nr * sectorsize) >> PAGE_SHIFT;
2475 if (!test_bit(sectornr, &rbio->dbitmap))
2477 if (rbio->stripe_pages[index])
2479 page = alloc_page(GFP_NOFS);
2482 rbio->stripe_pages[index] = page;
2484 index_stripe_sectors(rbio);
2488 static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check)
2490 struct btrfs_io_context *bioc = rbio->bioc;
2491 const u32 sectorsize = bioc->fs_info->sectorsize;
2492 void **pointers = rbio->finish_pointers;
2493 unsigned long *pbitmap = &rbio->finish_pbitmap;
2494 int nr_data = rbio->nr_data;
2498 struct sector_ptr p_sector = { 0 };
2499 struct sector_ptr q_sector = { 0 };
2500 struct bio_list bio_list;
2505 bio_list_init(&bio_list);
2507 if (rbio->real_stripes - rbio->nr_data == 1)
2508 has_qstripe = false;
2509 else if (rbio->real_stripes - rbio->nr_data == 2)
2514 if (bioc->num_tgtdevs && bioc->tgtdev_map[rbio->scrubp]) {
2516 bitmap_copy(pbitmap, &rbio->dbitmap, rbio->stripe_nsectors);
2520 * Because the higher layers(scrubber) are unlikely to
2521 * use this area of the disk again soon, so don't cache
2524 clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
2529 p_sector.page = alloc_page(GFP_NOFS);
2533 p_sector.uptodate = 1;
2536 /* RAID6, allocate and map temp space for the Q stripe */
2537 q_sector.page = alloc_page(GFP_NOFS);
2538 if (!q_sector.page) {
2539 __free_page(p_sector.page);
2540 p_sector.page = NULL;
2544 q_sector.uptodate = 1;
2545 pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page);
2548 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2550 /* Map the parity stripe just once */
2551 pointers[nr_data] = kmap_local_page(p_sector.page);
2553 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2554 struct sector_ptr *sector;
2557 /* first collect one page from each data stripe */
2558 for (stripe = 0; stripe < nr_data; stripe++) {
2559 sector = sector_in_rbio(rbio, stripe, sectornr, 0);
2560 pointers[stripe] = kmap_local_page(sector->page) +
2565 /* RAID6, call the library function to fill in our P/Q */
2566 raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
2570 memcpy(pointers[nr_data], pointers[0], sectorsize);
2571 run_xor(pointers + 1, nr_data - 1, sectorsize);
2574 /* Check scrubbing parity and repair it */
2575 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2576 parity = kmap_local_page(sector->page) + sector->pgoff;
2577 if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0)
2578 memcpy(parity, pointers[rbio->scrubp], sectorsize);
2580 /* Parity is right, needn't writeback */
2581 bitmap_clear(&rbio->dbitmap, sectornr, 1);
2582 kunmap_local(parity);
2584 for (stripe = nr_data - 1; stripe >= 0; stripe--)
2585 kunmap_local(pointers[stripe]);
2588 kunmap_local(pointers[nr_data]);
2589 __free_page(p_sector.page);
2590 p_sector.page = NULL;
2591 if (q_sector.page) {
2592 kunmap_local(pointers[rbio->real_stripes - 1]);
2593 __free_page(q_sector.page);
2594 q_sector.page = NULL;
2599 * time to start writing. Make bios for everything from the
2600 * higher layers (the bio_list in our rbio) and our p/q. Ignore
2603 for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
2604 struct sector_ptr *sector;
2606 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2607 ret = rbio_add_io_sector(rbio, &bio_list, sector, rbio->scrubp,
2608 sectornr, REQ_OP_WRITE);
2616 for_each_set_bit(sectornr, pbitmap, rbio->stripe_nsectors) {
2617 struct sector_ptr *sector;
2619 sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
2620 ret = rbio_add_io_sector(rbio, &bio_list, sector,
2621 bioc->tgtdev_map[rbio->scrubp],
2622 sectornr, REQ_OP_WRITE);
2628 submit_write_bios(rbio, &bio_list);
2632 while ((bio = bio_list_pop(&bio_list)))
2637 static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
2639 if (stripe >= 0 && stripe < rbio->nr_data)
2644 static int recover_scrub_rbio(struct btrfs_raid_bio *rbio)
2646 void **pointers = NULL;
2647 void **unmap_array = NULL;
2652 * @pointers array stores the pointer for each sector.
2654 * @unmap_array stores copy of pointers that does not get reordered
2655 * during reconstruction so that kunmap_local works.
2657 pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2658 unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
2659 if (!pointers || !unmap_array) {
2664 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2665 int dfail = 0, failp = -1;
2670 found_errors = get_rbio_veritical_errors(rbio, sector_nr,
2672 if (found_errors > rbio->bioc->max_errors) {
2676 if (found_errors == 0)
2679 /* We should have at least one error here. */
2680 ASSERT(faila >= 0 || failb >= 0);
2682 if (is_data_stripe(rbio, faila))
2684 else if (is_parity_stripe(faila))
2687 if (is_data_stripe(rbio, failb))
2689 else if (is_parity_stripe(failb))
2692 * Because we can not use a scrubbing parity to repair the
2693 * data, so the capability of the repair is declined. (In the
2694 * case of RAID5, we can not repair anything.)
2696 if (dfail > rbio->bioc->max_errors - 1) {
2701 * If all data is good, only parity is correctly, just repair
2702 * the parity, no need to recover data stripes.
2708 * Here means we got one corrupted data stripe and one
2709 * corrupted parity on RAID6, if the corrupted parity is
2710 * scrubbing parity, luckily, use the other one to repair the
2711 * data, or we can not repair the data stripe.
2713 if (failp != rbio->scrubp) {
2718 ret = recover_vertical(rbio, sector_nr, pointers, unmap_array);
2728 static int scrub_assemble_read_bios(struct btrfs_raid_bio *rbio,
2729 struct bio_list *bio_list)
2732 int total_sector_nr;
2735 ASSERT(bio_list_size(bio_list) == 0);
2737 /* Build a list of bios to read all the missing parts. */
2738 for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
2739 total_sector_nr++) {
2740 int sectornr = total_sector_nr % rbio->stripe_nsectors;
2741 int stripe = total_sector_nr / rbio->stripe_nsectors;
2742 struct sector_ptr *sector;
2744 /* No data in the vertical stripe, no need to read. */
2745 if (!test_bit(sectornr, &rbio->dbitmap))
2749 * We want to find all the sectors missing from the rbio and
2750 * read them from the disk. If sector_in_rbio() finds a sector
2751 * in the bio list we don't need to read it off the stripe.
2753 sector = sector_in_rbio(rbio, stripe, sectornr, 1);
2757 sector = rbio_stripe_sector(rbio, stripe, sectornr);
2759 * The bio cache may have handed us an uptodate sector. If so,
2762 if (sector->uptodate)
2765 ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
2766 sectornr, REQ_OP_READ);
2772 while ((bio = bio_list_pop(bio_list)))
2777 static int scrub_rbio(struct btrfs_raid_bio *rbio)
2779 bool need_check = false;
2780 struct bio_list bio_list;
2785 bio_list_init(&bio_list);
2787 ret = alloc_rbio_essential_pages(rbio);
2791 bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
2793 ret = scrub_assemble_read_bios(rbio, &bio_list);
2797 submit_read_bios(rbio, &bio_list);
2798 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2800 /* We may have some failures, recover the failed sectors first. */
2801 ret = recover_scrub_rbio(rbio);
2806 * We have every sector properly prepared. Can finish the scrub
2807 * and writeback the good content.
2809 ret = finish_parity_scrub(rbio, need_check);
2810 wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
2811 for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
2814 found_errors = get_rbio_veritical_errors(rbio, sector_nr, NULL, NULL);
2815 if (found_errors > rbio->bioc->max_errors) {
2823 while ((bio = bio_list_pop(&bio_list)))
2829 static void scrub_rbio_work_locked(struct work_struct *work)
2831 struct btrfs_raid_bio *rbio;
2834 rbio = container_of(work, struct btrfs_raid_bio, work);
2835 ret = scrub_rbio(rbio);
2836 rbio_orig_end_io(rbio, errno_to_blk_status(ret));
2839 void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
2841 if (!lock_stripe_add(rbio))
2842 start_async_work(rbio, scrub_rbio_work_locked);
2845 /* The following code is used for dev replace of a missing RAID 5/6 device. */
2847 struct btrfs_raid_bio *
2848 raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc)
2850 struct btrfs_fs_info *fs_info = bioc->fs_info;
2851 struct btrfs_raid_bio *rbio;
2853 rbio = alloc_rbio(fs_info, bioc);
2857 rbio->operation = BTRFS_RBIO_REBUILD_MISSING;
2858 bio_list_add(&rbio->bio_list, bio);
2860 * This is a special bio which is used to hold the completion handler
2861 * and make the scrub rbio is similar to the other types
2863 ASSERT(!bio->bi_iter.bi_size);
2865 set_rbio_range_error(rbio, bio);
2870 void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio)
2872 start_async_work(rbio, recover_rbio_work);