2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is seq_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/module.h>
51 #include <linux/async.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpu.h>
54 #include <linux/slab.h>
55 #include <linux/ratelimit.h>
56 #include <linux/nodemask.h>
57 #include <linux/flex_array.h>
58 #include <trace/events/block.h>
65 #define cpu_to_group(cpu) cpu_to_node(cpu)
66 #define ANY_GROUP NUMA_NO_NODE
68 static bool devices_handle_discard_safely = false;
69 module_param(devices_handle_discard_safely, bool, 0644);
70 MODULE_PARM_DESC(devices_handle_discard_safely,
71 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
72 static struct workqueue_struct *raid5_wq;
77 #define NR_STRIPES 256
78 #define STRIPE_SIZE PAGE_SIZE
79 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
80 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
81 #define IO_THRESHOLD 1
82 #define BYPASS_THRESHOLD 1
83 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
84 #define HASH_MASK (NR_HASH - 1)
85 #define MAX_STRIPE_BATCH 8
87 static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
89 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK;
90 return &conf->stripe_hashtbl[hash];
93 static inline int stripe_hash_locks_hash(sector_t sect)
95 return (sect >> STRIPE_SHIFT) & STRIPE_HASH_LOCKS_MASK;
98 static inline void lock_device_hash_lock(struct r5conf *conf, int hash)
100 spin_lock_irq(conf->hash_locks + hash);
101 spin_lock(&conf->device_lock);
104 static inline void unlock_device_hash_lock(struct r5conf *conf, int hash)
106 spin_unlock(&conf->device_lock);
107 spin_unlock_irq(conf->hash_locks + hash);
110 static inline void lock_all_device_hash_locks_irq(struct r5conf *conf)
114 spin_lock(conf->hash_locks);
115 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
116 spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks);
117 spin_lock(&conf->device_lock);
120 static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf)
123 spin_unlock(&conf->device_lock);
124 for (i = NR_STRIPE_HASH_LOCKS; i; i--)
125 spin_unlock(conf->hash_locks + i - 1);
129 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
130 * order without overlap. There may be several bio's per stripe+device, and
131 * a bio could span several devices.
132 * When walking this list for a particular stripe+device, we must never proceed
133 * beyond a bio that extends past this device, as the next bio might no longer
135 * This function is used to determine the 'next' bio in the list, given the sector
136 * of the current stripe+device
138 static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
140 int sectors = bio_sectors(bio);
141 if (bio->bi_iter.bi_sector + sectors < sector + STRIPE_SECTORS)
148 * We maintain a biased count of active stripes in the bottom 16 bits of
149 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
151 static inline int raid5_bi_processed_stripes(struct bio *bio)
153 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
154 return (atomic_read(segments) >> 16) & 0xffff;
157 static inline int raid5_dec_bi_active_stripes(struct bio *bio)
159 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
160 return atomic_sub_return(1, segments) & 0xffff;
163 static inline void raid5_inc_bi_active_stripes(struct bio *bio)
165 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
166 atomic_inc(segments);
169 static inline void raid5_set_bi_processed_stripes(struct bio *bio,
172 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
176 old = atomic_read(segments);
177 new = (old & 0xffff) | (cnt << 16);
178 } while (atomic_cmpxchg(segments, old, new) != old);
181 static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
183 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
184 atomic_set(segments, cnt);
187 /* Find first data disk in a raid6 stripe */
188 static inline int raid6_d0(struct stripe_head *sh)
191 /* ddf always start from first device */
193 /* md starts just after Q block */
194 if (sh->qd_idx == sh->disks - 1)
197 return sh->qd_idx + 1;
199 static inline int raid6_next_disk(int disk, int raid_disks)
202 return (disk < raid_disks) ? disk : 0;
205 /* When walking through the disks in a raid5, starting at raid6_d0,
206 * We need to map each disk to a 'slot', where the data disks are slot
207 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
208 * is raid_disks-1. This help does that mapping.
210 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
211 int *count, int syndrome_disks)
217 if (idx == sh->pd_idx)
218 return syndrome_disks;
219 if (idx == sh->qd_idx)
220 return syndrome_disks + 1;
226 static void return_io(struct bio *return_bi)
228 struct bio *bi = return_bi;
231 return_bi = bi->bi_next;
233 bi->bi_iter.bi_size = 0;
234 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
241 static void print_raid5_conf (struct r5conf *conf);
243 static int stripe_operations_active(struct stripe_head *sh)
245 return sh->check_state || sh->reconstruct_state ||
246 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
247 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
250 static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
252 struct r5conf *conf = sh->raid_conf;
253 struct r5worker_group *group;
255 int i, cpu = sh->cpu;
257 if (!cpu_online(cpu)) {
258 cpu = cpumask_any(cpu_online_mask);
262 if (list_empty(&sh->lru)) {
263 struct r5worker_group *group;
264 group = conf->worker_groups + cpu_to_group(cpu);
265 list_add_tail(&sh->lru, &group->handle_list);
266 group->stripes_cnt++;
270 if (conf->worker_cnt_per_group == 0) {
271 md_wakeup_thread(conf->mddev->thread);
275 group = conf->worker_groups + cpu_to_group(sh->cpu);
277 group->workers[0].working = true;
278 /* at least one worker should run to avoid race */
279 queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
281 thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
282 /* wakeup more workers */
283 for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
284 if (group->workers[i].working == false) {
285 group->workers[i].working = true;
286 queue_work_on(sh->cpu, raid5_wq,
287 &group->workers[i].work);
293 static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
294 struct list_head *temp_inactive_list)
296 BUG_ON(!list_empty(&sh->lru));
297 BUG_ON(atomic_read(&conf->active_stripes)==0);
298 if (test_bit(STRIPE_HANDLE, &sh->state)) {
299 if (test_bit(STRIPE_DELAYED, &sh->state) &&
300 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
301 list_add_tail(&sh->lru, &conf->delayed_list);
302 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
303 sh->bm_seq - conf->seq_write > 0)
304 list_add_tail(&sh->lru, &conf->bitmap_list);
306 clear_bit(STRIPE_DELAYED, &sh->state);
307 clear_bit(STRIPE_BIT_DELAY, &sh->state);
308 if (conf->worker_cnt_per_group == 0) {
309 list_add_tail(&sh->lru, &conf->handle_list);
311 raid5_wakeup_stripe_thread(sh);
315 md_wakeup_thread(conf->mddev->thread);
317 BUG_ON(stripe_operations_active(sh));
318 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
319 if (atomic_dec_return(&conf->preread_active_stripes)
321 md_wakeup_thread(conf->mddev->thread);
322 atomic_dec(&conf->active_stripes);
323 if (!test_bit(STRIPE_EXPANDING, &sh->state))
324 list_add_tail(&sh->lru, temp_inactive_list);
328 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
329 struct list_head *temp_inactive_list)
331 if (atomic_dec_and_test(&sh->count))
332 do_release_stripe(conf, sh, temp_inactive_list);
336 * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
338 * Be careful: Only one task can add/delete stripes from temp_inactive_list at
339 * given time. Adding stripes only takes device lock, while deleting stripes
340 * only takes hash lock.
342 static void release_inactive_stripe_list(struct r5conf *conf,
343 struct list_head *temp_inactive_list,
347 bool do_wakeup = false;
350 if (hash == NR_STRIPE_HASH_LOCKS) {
351 size = NR_STRIPE_HASH_LOCKS;
352 hash = NR_STRIPE_HASH_LOCKS - 1;
356 struct list_head *list = &temp_inactive_list[size - 1];
359 * We don't hold any lock here yet, get_active_stripe() might
360 * remove stripes from the list
362 if (!list_empty_careful(list)) {
363 spin_lock_irqsave(conf->hash_locks + hash, flags);
364 if (list_empty(conf->inactive_list + hash) &&
366 atomic_dec(&conf->empty_inactive_list_nr);
367 list_splice_tail_init(list, conf->inactive_list + hash);
369 spin_unlock_irqrestore(conf->hash_locks + hash, flags);
376 wake_up(&conf->wait_for_stripe);
377 if (conf->retry_read_aligned)
378 md_wakeup_thread(conf->mddev->thread);
382 /* should hold conf->device_lock already */
383 static int release_stripe_list(struct r5conf *conf,
384 struct list_head *temp_inactive_list)
386 struct stripe_head *sh;
388 struct llist_node *head;
390 head = llist_del_all(&conf->released_stripes);
391 head = llist_reverse_order(head);
395 sh = llist_entry(head, struct stripe_head, release_list);
396 head = llist_next(head);
397 /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
399 clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
401 * Don't worry the bit is set here, because if the bit is set
402 * again, the count is always > 1. This is true for
403 * STRIPE_ON_UNPLUG_LIST bit too.
405 hash = sh->hash_lock_index;
406 __release_stripe(conf, sh, &temp_inactive_list[hash]);
413 static void release_stripe(struct stripe_head *sh)
415 struct r5conf *conf = sh->raid_conf;
417 struct list_head list;
421 /* Avoid release_list until the last reference.
423 if (atomic_add_unless(&sh->count, -1, 1))
426 if (unlikely(!conf->mddev->thread) ||
427 test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
429 wakeup = llist_add(&sh->release_list, &conf->released_stripes);
431 md_wakeup_thread(conf->mddev->thread);
434 local_irq_save(flags);
435 /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
436 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
437 INIT_LIST_HEAD(&list);
438 hash = sh->hash_lock_index;
439 do_release_stripe(conf, sh, &list);
440 spin_unlock(&conf->device_lock);
441 release_inactive_stripe_list(conf, &list, hash);
443 local_irq_restore(flags);
446 static inline void remove_hash(struct stripe_head *sh)
448 pr_debug("remove_hash(), stripe %llu\n",
449 (unsigned long long)sh->sector);
451 hlist_del_init(&sh->hash);
454 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
456 struct hlist_head *hp = stripe_hash(conf, sh->sector);
458 pr_debug("insert_hash(), stripe %llu\n",
459 (unsigned long long)sh->sector);
461 hlist_add_head(&sh->hash, hp);
464 /* find an idle stripe, make sure it is unhashed, and return it. */
465 static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash)
467 struct stripe_head *sh = NULL;
468 struct list_head *first;
470 if (list_empty(conf->inactive_list + hash))
472 first = (conf->inactive_list + hash)->next;
473 sh = list_entry(first, struct stripe_head, lru);
474 list_del_init(first);
476 atomic_inc(&conf->active_stripes);
477 BUG_ON(hash != sh->hash_lock_index);
478 if (list_empty(conf->inactive_list + hash))
479 atomic_inc(&conf->empty_inactive_list_nr);
484 static void shrink_buffers(struct stripe_head *sh)
488 int num = sh->raid_conf->pool_size;
490 for (i = 0; i < num ; i++) {
491 WARN_ON(sh->dev[i].page != sh->dev[i].orig_page);
495 sh->dev[i].page = NULL;
500 static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
503 int num = sh->raid_conf->pool_size;
505 for (i = 0; i < num; i++) {
508 if (!(page = alloc_page(gfp))) {
511 sh->dev[i].page = page;
512 sh->dev[i].orig_page = page;
517 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
518 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
519 struct stripe_head *sh);
521 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
523 struct r5conf *conf = sh->raid_conf;
526 BUG_ON(atomic_read(&sh->count) != 0);
527 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
528 BUG_ON(stripe_operations_active(sh));
529 BUG_ON(sh->batch_head);
531 pr_debug("init_stripe called, stripe %llu\n",
532 (unsigned long long)sector);
534 seq = read_seqcount_begin(&conf->gen_lock);
535 sh->generation = conf->generation - previous;
536 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
538 stripe_set_idx(sector, conf, previous, sh);
541 for (i = sh->disks; i--; ) {
542 struct r5dev *dev = &sh->dev[i];
544 if (dev->toread || dev->read || dev->towrite || dev->written ||
545 test_bit(R5_LOCKED, &dev->flags)) {
546 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
547 (unsigned long long)sh->sector, i, dev->toread,
548 dev->read, dev->towrite, dev->written,
549 test_bit(R5_LOCKED, &dev->flags));
553 raid5_build_block(sh, i, previous);
555 if (read_seqcount_retry(&conf->gen_lock, seq))
557 sh->overwrite_disks = 0;
558 insert_hash(conf, sh);
559 sh->cpu = smp_processor_id();
560 set_bit(STRIPE_BATCH_READY, &sh->state);
563 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
566 struct stripe_head *sh;
568 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
569 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
570 if (sh->sector == sector && sh->generation == generation)
572 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
577 * Need to check if array has failed when deciding whether to:
579 * - remove non-faulty devices
582 * This determination is simple when no reshape is happening.
583 * However if there is a reshape, we need to carefully check
584 * both the before and after sections.
585 * This is because some failed devices may only affect one
586 * of the two sections, and some non-in_sync devices may
587 * be insync in the section most affected by failed devices.
589 static int calc_degraded(struct r5conf *conf)
591 int degraded, degraded2;
596 for (i = 0; i < conf->previous_raid_disks; i++) {
597 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
598 if (rdev && test_bit(Faulty, &rdev->flags))
599 rdev = rcu_dereference(conf->disks[i].replacement);
600 if (!rdev || test_bit(Faulty, &rdev->flags))
602 else if (test_bit(In_sync, &rdev->flags))
605 /* not in-sync or faulty.
606 * If the reshape increases the number of devices,
607 * this is being recovered by the reshape, so
608 * this 'previous' section is not in_sync.
609 * If the number of devices is being reduced however,
610 * the device can only be part of the array if
611 * we are reverting a reshape, so this section will
614 if (conf->raid_disks >= conf->previous_raid_disks)
618 if (conf->raid_disks == conf->previous_raid_disks)
622 for (i = 0; i < conf->raid_disks; i++) {
623 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
624 if (rdev && test_bit(Faulty, &rdev->flags))
625 rdev = rcu_dereference(conf->disks[i].replacement);
626 if (!rdev || test_bit(Faulty, &rdev->flags))
628 else if (test_bit(In_sync, &rdev->flags))
631 /* not in-sync or faulty.
632 * If reshape increases the number of devices, this
633 * section has already been recovered, else it
634 * almost certainly hasn't.
636 if (conf->raid_disks <= conf->previous_raid_disks)
640 if (degraded2 > degraded)
645 static int has_failed(struct r5conf *conf)
649 if (conf->mddev->reshape_position == MaxSector)
650 return conf->mddev->degraded > conf->max_degraded;
652 degraded = calc_degraded(conf);
653 if (degraded > conf->max_degraded)
658 static struct stripe_head *
659 get_active_stripe(struct r5conf *conf, sector_t sector,
660 int previous, int noblock, int noquiesce)
662 struct stripe_head *sh;
663 int hash = stripe_hash_locks_hash(sector);
665 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
667 spin_lock_irq(conf->hash_locks + hash);
670 wait_event_lock_irq(conf->wait_for_stripe,
671 conf->quiesce == 0 || noquiesce,
672 *(conf->hash_locks + hash));
673 sh = __find_stripe(conf, sector, conf->generation - previous);
675 if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
676 sh = get_free_stripe(conf, hash);
677 if (!sh && llist_empty(&conf->released_stripes) &&
678 !test_bit(R5_DID_ALLOC, &conf->cache_state))
679 set_bit(R5_ALLOC_MORE,
682 if (noblock && sh == NULL)
685 set_bit(R5_INACTIVE_BLOCKED,
688 conf->wait_for_stripe,
689 !list_empty(conf->inactive_list + hash) &&
690 (atomic_read(&conf->active_stripes)
691 < (conf->max_nr_stripes * 3 / 4)
692 || !test_bit(R5_INACTIVE_BLOCKED,
693 &conf->cache_state)),
694 *(conf->hash_locks + hash));
695 clear_bit(R5_INACTIVE_BLOCKED,
698 init_stripe(sh, sector, previous);
699 atomic_inc(&sh->count);
701 } else if (!atomic_inc_not_zero(&sh->count)) {
702 spin_lock(&conf->device_lock);
703 if (!atomic_read(&sh->count)) {
704 if (!test_bit(STRIPE_HANDLE, &sh->state))
705 atomic_inc(&conf->active_stripes);
706 BUG_ON(list_empty(&sh->lru) &&
707 !test_bit(STRIPE_EXPANDING, &sh->state));
708 list_del_init(&sh->lru);
710 sh->group->stripes_cnt--;
714 atomic_inc(&sh->count);
715 spin_unlock(&conf->device_lock);
717 } while (sh == NULL);
719 spin_unlock_irq(conf->hash_locks + hash);
723 static bool is_full_stripe_write(struct stripe_head *sh)
725 BUG_ON(sh->overwrite_disks > (sh->disks - sh->raid_conf->max_degraded));
726 return sh->overwrite_disks == (sh->disks - sh->raid_conf->max_degraded);
729 static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
733 spin_lock(&sh2->stripe_lock);
734 spin_lock_nested(&sh1->stripe_lock, 1);
736 spin_lock(&sh1->stripe_lock);
737 spin_lock_nested(&sh2->stripe_lock, 1);
741 static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
743 spin_unlock(&sh1->stripe_lock);
744 spin_unlock(&sh2->stripe_lock);
748 /* Only freshly new full stripe normal write stripe can be added to a batch list */
749 static bool stripe_can_batch(struct stripe_head *sh)
751 return test_bit(STRIPE_BATCH_READY, &sh->state) &&
752 !test_bit(STRIPE_BITMAP_PENDING, &sh->state) &&
753 is_full_stripe_write(sh);
756 /* we only do back search */
757 static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh)
759 struct stripe_head *head;
760 sector_t head_sector, tmp_sec;
764 if (!stripe_can_batch(sh))
766 /* Don't cross chunks, so stripe pd_idx/qd_idx is the same */
767 tmp_sec = sh->sector;
768 if (!sector_div(tmp_sec, conf->chunk_sectors))
770 head_sector = sh->sector - STRIPE_SECTORS;
772 hash = stripe_hash_locks_hash(head_sector);
773 spin_lock_irq(conf->hash_locks + hash);
774 head = __find_stripe(conf, head_sector, conf->generation);
775 if (head && !atomic_inc_not_zero(&head->count)) {
776 spin_lock(&conf->device_lock);
777 if (!atomic_read(&head->count)) {
778 if (!test_bit(STRIPE_HANDLE, &head->state))
779 atomic_inc(&conf->active_stripes);
780 BUG_ON(list_empty(&head->lru) &&
781 !test_bit(STRIPE_EXPANDING, &head->state));
782 list_del_init(&head->lru);
784 head->group->stripes_cnt--;
788 atomic_inc(&head->count);
789 spin_unlock(&conf->device_lock);
791 spin_unlock_irq(conf->hash_locks + hash);
795 if (!stripe_can_batch(head))
798 lock_two_stripes(head, sh);
799 /* clear_batch_ready clear the flag */
800 if (!stripe_can_batch(head) || !stripe_can_batch(sh))
807 while (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
809 if (head->dev[dd_idx].towrite->bi_rw != sh->dev[dd_idx].towrite->bi_rw)
812 if (head->batch_head) {
813 spin_lock(&head->batch_head->batch_lock);
814 /* This batch list is already running */
815 if (!stripe_can_batch(head)) {
816 spin_unlock(&head->batch_head->batch_lock);
821 * at this point, head's BATCH_READY could be cleared, but we
822 * can still add the stripe to batch list
824 list_add(&sh->batch_list, &head->batch_list);
825 spin_unlock(&head->batch_head->batch_lock);
827 sh->batch_head = head->batch_head;
829 head->batch_head = head;
830 sh->batch_head = head->batch_head;
831 spin_lock(&head->batch_lock);
832 list_add_tail(&sh->batch_list, &head->batch_list);
833 spin_unlock(&head->batch_lock);
836 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
837 if (atomic_dec_return(&conf->preread_active_stripes)
839 md_wakeup_thread(conf->mddev->thread);
841 if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
842 int seq = sh->bm_seq;
843 if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
844 sh->batch_head->bm_seq > seq)
845 seq = sh->batch_head->bm_seq;
846 set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
847 sh->batch_head->bm_seq = seq;
850 atomic_inc(&sh->count);
852 unlock_two_stripes(head, sh);
854 release_stripe(head);
857 /* Determine if 'data_offset' or 'new_data_offset' should be used
858 * in this stripe_head.
860 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
862 sector_t progress = conf->reshape_progress;
863 /* Need a memory barrier to make sure we see the value
864 * of conf->generation, or ->data_offset that was set before
865 * reshape_progress was updated.
868 if (progress == MaxSector)
870 if (sh->generation == conf->generation - 1)
872 /* We are in a reshape, and this is a new-generation stripe,
873 * so use new_data_offset.
879 raid5_end_read_request(struct bio *bi, int error);
881 raid5_end_write_request(struct bio *bi, int error);
883 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
885 struct r5conf *conf = sh->raid_conf;
886 int i, disks = sh->disks;
887 struct stripe_head *head_sh = sh;
891 for (i = disks; i--; ) {
893 int replace_only = 0;
894 struct bio *bi, *rbi;
895 struct md_rdev *rdev, *rrdev = NULL;
898 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
899 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
903 if (test_bit(R5_Discard, &sh->dev[i].flags))
905 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
907 else if (test_and_clear_bit(R5_WantReplace,
908 &sh->dev[i].flags)) {
913 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
917 bi = &sh->dev[i].req;
918 rbi = &sh->dev[i].rreq; /* For writing to replacement */
921 rrdev = rcu_dereference(conf->disks[i].replacement);
922 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
923 rdev = rcu_dereference(conf->disks[i].rdev);
932 /* We raced and saw duplicates */
935 if (test_bit(R5_ReadRepl, &head_sh->dev[i].flags) && rrdev)
940 if (rdev && test_bit(Faulty, &rdev->flags))
943 atomic_inc(&rdev->nr_pending);
944 if (rrdev && test_bit(Faulty, &rrdev->flags))
947 atomic_inc(&rrdev->nr_pending);
950 /* We have already checked bad blocks for reads. Now
951 * need to check for writes. We never accept write errors
952 * on the replacement, so we don't to check rrdev.
954 while ((rw & WRITE) && rdev &&
955 test_bit(WriteErrorSeen, &rdev->flags)) {
958 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
959 &first_bad, &bad_sectors);
964 set_bit(BlockedBadBlocks, &rdev->flags);
965 if (!conf->mddev->external &&
966 conf->mddev->flags) {
967 /* It is very unlikely, but we might
968 * still need to write out the
969 * bad block log - better give it
971 md_check_recovery(conf->mddev);
974 * Because md_wait_for_blocked_rdev
975 * will dec nr_pending, we must
976 * increment it first.
978 atomic_inc(&rdev->nr_pending);
979 md_wait_for_blocked_rdev(rdev, conf->mddev);
981 /* Acknowledged bad block - skip the write */
982 rdev_dec_pending(rdev, conf->mddev);
988 if (s->syncing || s->expanding || s->expanded
990 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
992 set_bit(STRIPE_IO_STARTED, &sh->state);
995 bi->bi_bdev = rdev->bdev;
997 bi->bi_end_io = (rw & WRITE)
998 ? raid5_end_write_request
999 : raid5_end_read_request;
1000 bi->bi_private = sh;
1002 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
1003 __func__, (unsigned long long)sh->sector,
1005 atomic_inc(&sh->count);
1007 atomic_inc(&head_sh->count);
1008 if (use_new_offset(conf, sh))
1009 bi->bi_iter.bi_sector = (sh->sector
1010 + rdev->new_data_offset);
1012 bi->bi_iter.bi_sector = (sh->sector
1013 + rdev->data_offset);
1014 if (test_bit(R5_ReadNoMerge, &head_sh->dev[i].flags))
1015 bi->bi_rw |= REQ_NOMERGE;
1017 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1018 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1019 sh->dev[i].vec.bv_page = sh->dev[i].page;
1021 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1022 bi->bi_io_vec[0].bv_offset = 0;
1023 bi->bi_iter.bi_size = STRIPE_SIZE;
1025 * If this is discard request, set bi_vcnt 0. We don't
1026 * want to confuse SCSI because SCSI will replace payload
1028 if (rw & REQ_DISCARD)
1031 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
1033 if (conf->mddev->gendisk)
1034 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
1035 bi, disk_devt(conf->mddev->gendisk),
1037 generic_make_request(bi);
1040 if (s->syncing || s->expanding || s->expanded
1042 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
1044 set_bit(STRIPE_IO_STARTED, &sh->state);
1047 rbi->bi_bdev = rrdev->bdev;
1049 BUG_ON(!(rw & WRITE));
1050 rbi->bi_end_io = raid5_end_write_request;
1051 rbi->bi_private = sh;
1053 pr_debug("%s: for %llu schedule op %ld on "
1054 "replacement disc %d\n",
1055 __func__, (unsigned long long)sh->sector,
1057 atomic_inc(&sh->count);
1059 atomic_inc(&head_sh->count);
1060 if (use_new_offset(conf, sh))
1061 rbi->bi_iter.bi_sector = (sh->sector
1062 + rrdev->new_data_offset);
1064 rbi->bi_iter.bi_sector = (sh->sector
1065 + rrdev->data_offset);
1066 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1067 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1068 sh->dev[i].rvec.bv_page = sh->dev[i].page;
1070 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1071 rbi->bi_io_vec[0].bv_offset = 0;
1072 rbi->bi_iter.bi_size = STRIPE_SIZE;
1074 * If this is discard request, set bi_vcnt 0. We don't
1075 * want to confuse SCSI because SCSI will replace payload
1077 if (rw & REQ_DISCARD)
1079 if (conf->mddev->gendisk)
1080 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
1081 rbi, disk_devt(conf->mddev->gendisk),
1083 generic_make_request(rbi);
1085 if (!rdev && !rrdev) {
1087 set_bit(STRIPE_DEGRADED, &sh->state);
1088 pr_debug("skip op %ld on disc %d for sector %llu\n",
1089 bi->bi_rw, i, (unsigned long long)sh->sector);
1090 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1091 set_bit(STRIPE_HANDLE, &sh->state);
1094 if (!head_sh->batch_head)
1096 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1103 static struct dma_async_tx_descriptor *
1104 async_copy_data(int frombio, struct bio *bio, struct page **page,
1105 sector_t sector, struct dma_async_tx_descriptor *tx,
1106 struct stripe_head *sh)
1109 struct bvec_iter iter;
1110 struct page *bio_page;
1112 struct async_submit_ctl submit;
1113 enum async_tx_flags flags = 0;
1115 if (bio->bi_iter.bi_sector >= sector)
1116 page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512;
1118 page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512;
1121 flags |= ASYNC_TX_FENCE;
1122 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
1124 bio_for_each_segment(bvl, bio, iter) {
1125 int len = bvl.bv_len;
1129 if (page_offset < 0) {
1130 b_offset = -page_offset;
1131 page_offset += b_offset;
1135 if (len > 0 && page_offset + len > STRIPE_SIZE)
1136 clen = STRIPE_SIZE - page_offset;
1141 b_offset += bvl.bv_offset;
1142 bio_page = bvl.bv_page;
1144 if (sh->raid_conf->skip_copy &&
1145 b_offset == 0 && page_offset == 0 &&
1146 clen == STRIPE_SIZE)
1149 tx = async_memcpy(*page, bio_page, page_offset,
1150 b_offset, clen, &submit);
1152 tx = async_memcpy(bio_page, *page, b_offset,
1153 page_offset, clen, &submit);
1155 /* chain the operations */
1156 submit.depend_tx = tx;
1158 if (clen < len) /* hit end of page */
1166 static void ops_complete_biofill(void *stripe_head_ref)
1168 struct stripe_head *sh = stripe_head_ref;
1169 struct bio *return_bi = NULL;
1172 pr_debug("%s: stripe %llu\n", __func__,
1173 (unsigned long long)sh->sector);
1175 /* clear completed biofills */
1176 for (i = sh->disks; i--; ) {
1177 struct r5dev *dev = &sh->dev[i];
1179 /* acknowledge completion of a biofill operation */
1180 /* and check if we need to reply to a read request,
1181 * new R5_Wantfill requests are held off until
1182 * !STRIPE_BIOFILL_RUN
1184 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
1185 struct bio *rbi, *rbi2;
1190 while (rbi && rbi->bi_iter.bi_sector <
1191 dev->sector + STRIPE_SECTORS) {
1192 rbi2 = r5_next_bio(rbi, dev->sector);
1193 if (!raid5_dec_bi_active_stripes(rbi)) {
1194 rbi->bi_next = return_bi;
1201 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
1203 return_io(return_bi);
1205 set_bit(STRIPE_HANDLE, &sh->state);
1209 static void ops_run_biofill(struct stripe_head *sh)
1211 struct dma_async_tx_descriptor *tx = NULL;
1212 struct async_submit_ctl submit;
1215 BUG_ON(sh->batch_head);
1216 pr_debug("%s: stripe %llu\n", __func__,
1217 (unsigned long long)sh->sector);
1219 for (i = sh->disks; i--; ) {
1220 struct r5dev *dev = &sh->dev[i];
1221 if (test_bit(R5_Wantfill, &dev->flags)) {
1223 spin_lock_irq(&sh->stripe_lock);
1224 dev->read = rbi = dev->toread;
1226 spin_unlock_irq(&sh->stripe_lock);
1227 while (rbi && rbi->bi_iter.bi_sector <
1228 dev->sector + STRIPE_SECTORS) {
1229 tx = async_copy_data(0, rbi, &dev->page,
1230 dev->sector, tx, sh);
1231 rbi = r5_next_bio(rbi, dev->sector);
1236 atomic_inc(&sh->count);
1237 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
1238 async_trigger_callback(&submit);
1241 static void mark_target_uptodate(struct stripe_head *sh, int target)
1248 tgt = &sh->dev[target];
1249 set_bit(R5_UPTODATE, &tgt->flags);
1250 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1251 clear_bit(R5_Wantcompute, &tgt->flags);
1254 static void ops_complete_compute(void *stripe_head_ref)
1256 struct stripe_head *sh = stripe_head_ref;
1258 pr_debug("%s: stripe %llu\n", __func__,
1259 (unsigned long long)sh->sector);
1261 /* mark the computed target(s) as uptodate */
1262 mark_target_uptodate(sh, sh->ops.target);
1263 mark_target_uptodate(sh, sh->ops.target2);
1265 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
1266 if (sh->check_state == check_state_compute_run)
1267 sh->check_state = check_state_compute_result;
1268 set_bit(STRIPE_HANDLE, &sh->state);
1272 /* return a pointer to the address conversion region of the scribble buffer */
1273 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
1274 struct raid5_percpu *percpu, int i)
1278 addr = flex_array_get(percpu->scribble, i);
1279 return addr + sizeof(struct page *) * (sh->disks + 2);
1282 /* return a pointer to the address conversion region of the scribble buffer */
1283 static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
1287 addr = flex_array_get(percpu->scribble, i);
1291 static struct dma_async_tx_descriptor *
1292 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
1294 int disks = sh->disks;
1295 struct page **xor_srcs = to_addr_page(percpu, 0);
1296 int target = sh->ops.target;
1297 struct r5dev *tgt = &sh->dev[target];
1298 struct page *xor_dest = tgt->page;
1300 struct dma_async_tx_descriptor *tx;
1301 struct async_submit_ctl submit;
1304 BUG_ON(sh->batch_head);
1306 pr_debug("%s: stripe %llu block: %d\n",
1307 __func__, (unsigned long long)sh->sector, target);
1308 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1310 for (i = disks; i--; )
1312 xor_srcs[count++] = sh->dev[i].page;
1314 atomic_inc(&sh->count);
1316 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
1317 ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));
1318 if (unlikely(count == 1))
1319 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1321 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1326 /* set_syndrome_sources - populate source buffers for gen_syndrome
1327 * @srcs - (struct page *) array of size sh->disks
1328 * @sh - stripe_head to parse
1330 * Populates srcs in proper layout order for the stripe and returns the
1331 * 'count' of sources to be used in a call to async_gen_syndrome. The P
1332 * destination buffer is recorded in srcs[count] and the Q destination
1333 * is recorded in srcs[count+1]].
1335 static int set_syndrome_sources(struct page **srcs,
1336 struct stripe_head *sh,
1339 int disks = sh->disks;
1340 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1341 int d0_idx = raid6_d0(sh);
1345 for (i = 0; i < disks; i++)
1351 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1352 struct r5dev *dev = &sh->dev[i];
1354 if (i == sh->qd_idx || i == sh->pd_idx ||
1355 (srctype == SYNDROME_SRC_ALL) ||
1356 (srctype == SYNDROME_SRC_WANT_DRAIN &&
1357 test_bit(R5_Wantdrain, &dev->flags)) ||
1358 (srctype == SYNDROME_SRC_WRITTEN &&
1360 srcs[slot] = sh->dev[i].page;
1361 i = raid6_next_disk(i, disks);
1362 } while (i != d0_idx);
1364 return syndrome_disks;
1367 static struct dma_async_tx_descriptor *
1368 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
1370 int disks = sh->disks;
1371 struct page **blocks = to_addr_page(percpu, 0);
1373 int qd_idx = sh->qd_idx;
1374 struct dma_async_tx_descriptor *tx;
1375 struct async_submit_ctl submit;
1381 BUG_ON(sh->batch_head);
1382 if (sh->ops.target < 0)
1383 target = sh->ops.target2;
1384 else if (sh->ops.target2 < 0)
1385 target = sh->ops.target;
1387 /* we should only have one valid target */
1390 pr_debug("%s: stripe %llu block: %d\n",
1391 __func__, (unsigned long long)sh->sector, target);
1393 tgt = &sh->dev[target];
1394 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1397 atomic_inc(&sh->count);
1399 if (target == qd_idx) {
1400 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1401 blocks[count] = NULL; /* regenerating p is not necessary */
1402 BUG_ON(blocks[count+1] != dest); /* q should already be set */
1403 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1404 ops_complete_compute, sh,
1405 to_addr_conv(sh, percpu, 0));
1406 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1408 /* Compute any data- or p-drive using XOR */
1410 for (i = disks; i-- ; ) {
1411 if (i == target || i == qd_idx)
1413 blocks[count++] = sh->dev[i].page;
1416 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1417 NULL, ops_complete_compute, sh,
1418 to_addr_conv(sh, percpu, 0));
1419 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1425 static struct dma_async_tx_descriptor *
1426 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1428 int i, count, disks = sh->disks;
1429 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1430 int d0_idx = raid6_d0(sh);
1431 int faila = -1, failb = -1;
1432 int target = sh->ops.target;
1433 int target2 = sh->ops.target2;
1434 struct r5dev *tgt = &sh->dev[target];
1435 struct r5dev *tgt2 = &sh->dev[target2];
1436 struct dma_async_tx_descriptor *tx;
1437 struct page **blocks = to_addr_page(percpu, 0);
1438 struct async_submit_ctl submit;
1440 BUG_ON(sh->batch_head);
1441 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1442 __func__, (unsigned long long)sh->sector, target, target2);
1443 BUG_ON(target < 0 || target2 < 0);
1444 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1445 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1447 /* we need to open-code set_syndrome_sources to handle the
1448 * slot number conversion for 'faila' and 'failb'
1450 for (i = 0; i < disks ; i++)
1455 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1457 blocks[slot] = sh->dev[i].page;
1463 i = raid6_next_disk(i, disks);
1464 } while (i != d0_idx);
1466 BUG_ON(faila == failb);
1469 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1470 __func__, (unsigned long long)sh->sector, faila, failb);
1472 atomic_inc(&sh->count);
1474 if (failb == syndrome_disks+1) {
1475 /* Q disk is one of the missing disks */
1476 if (faila == syndrome_disks) {
1477 /* Missing P+Q, just recompute */
1478 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1479 ops_complete_compute, sh,
1480 to_addr_conv(sh, percpu, 0));
1481 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
1482 STRIPE_SIZE, &submit);
1486 int qd_idx = sh->qd_idx;
1488 /* Missing D+Q: recompute D from P, then recompute Q */
1489 if (target == qd_idx)
1490 data_target = target2;
1492 data_target = target;
1495 for (i = disks; i-- ; ) {
1496 if (i == data_target || i == qd_idx)
1498 blocks[count++] = sh->dev[i].page;
1500 dest = sh->dev[data_target].page;
1501 init_async_submit(&submit,
1502 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1504 to_addr_conv(sh, percpu, 0));
1505 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1508 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1509 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1510 ops_complete_compute, sh,
1511 to_addr_conv(sh, percpu, 0));
1512 return async_gen_syndrome(blocks, 0, count+2,
1513 STRIPE_SIZE, &submit);
1516 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1517 ops_complete_compute, sh,
1518 to_addr_conv(sh, percpu, 0));
1519 if (failb == syndrome_disks) {
1520 /* We're missing D+P. */
1521 return async_raid6_datap_recov(syndrome_disks+2,
1525 /* We're missing D+D. */
1526 return async_raid6_2data_recov(syndrome_disks+2,
1527 STRIPE_SIZE, faila, failb,
1533 static void ops_complete_prexor(void *stripe_head_ref)
1535 struct stripe_head *sh = stripe_head_ref;
1537 pr_debug("%s: stripe %llu\n", __func__,
1538 (unsigned long long)sh->sector);
1541 static struct dma_async_tx_descriptor *
1542 ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu,
1543 struct dma_async_tx_descriptor *tx)
1545 int disks = sh->disks;
1546 struct page **xor_srcs = to_addr_page(percpu, 0);
1547 int count = 0, pd_idx = sh->pd_idx, i;
1548 struct async_submit_ctl submit;
1550 /* existing parity data subtracted */
1551 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1553 BUG_ON(sh->batch_head);
1554 pr_debug("%s: stripe %llu\n", __func__,
1555 (unsigned long long)sh->sector);
1557 for (i = disks; i--; ) {
1558 struct r5dev *dev = &sh->dev[i];
1559 /* Only process blocks that are known to be uptodate */
1560 if (test_bit(R5_Wantdrain, &dev->flags))
1561 xor_srcs[count++] = dev->page;
1564 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1565 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1566 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1571 static struct dma_async_tx_descriptor *
1572 ops_run_prexor6(struct stripe_head *sh, struct raid5_percpu *percpu,
1573 struct dma_async_tx_descriptor *tx)
1575 struct page **blocks = to_addr_page(percpu, 0);
1577 struct async_submit_ctl submit;
1579 pr_debug("%s: stripe %llu\n", __func__,
1580 (unsigned long long)sh->sector);
1582 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_WANT_DRAIN);
1584 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_PQ_XOR_DST, tx,
1585 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1586 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1591 static struct dma_async_tx_descriptor *
1592 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1594 int disks = sh->disks;
1596 struct stripe_head *head_sh = sh;
1598 pr_debug("%s: stripe %llu\n", __func__,
1599 (unsigned long long)sh->sector);
1601 for (i = disks; i--; ) {
1606 if (test_and_clear_bit(R5_Wantdrain, &head_sh->dev[i].flags)) {
1611 spin_lock_irq(&sh->stripe_lock);
1612 chosen = dev->towrite;
1613 dev->towrite = NULL;
1614 sh->overwrite_disks = 0;
1615 BUG_ON(dev->written);
1616 wbi = dev->written = chosen;
1617 spin_unlock_irq(&sh->stripe_lock);
1618 WARN_ON(dev->page != dev->orig_page);
1620 while (wbi && wbi->bi_iter.bi_sector <
1621 dev->sector + STRIPE_SECTORS) {
1622 if (wbi->bi_rw & REQ_FUA)
1623 set_bit(R5_WantFUA, &dev->flags);
1624 if (wbi->bi_rw & REQ_SYNC)
1625 set_bit(R5_SyncIO, &dev->flags);
1626 if (wbi->bi_rw & REQ_DISCARD)
1627 set_bit(R5_Discard, &dev->flags);
1629 tx = async_copy_data(1, wbi, &dev->page,
1630 dev->sector, tx, sh);
1631 if (dev->page != dev->orig_page) {
1632 set_bit(R5_SkipCopy, &dev->flags);
1633 clear_bit(R5_UPTODATE, &dev->flags);
1634 clear_bit(R5_OVERWRITE, &dev->flags);
1637 wbi = r5_next_bio(wbi, dev->sector);
1640 if (head_sh->batch_head) {
1641 sh = list_first_entry(&sh->batch_list,
1654 static void ops_complete_reconstruct(void *stripe_head_ref)
1656 struct stripe_head *sh = stripe_head_ref;
1657 int disks = sh->disks;
1658 int pd_idx = sh->pd_idx;
1659 int qd_idx = sh->qd_idx;
1661 bool fua = false, sync = false, discard = false;
1663 pr_debug("%s: stripe %llu\n", __func__,
1664 (unsigned long long)sh->sector);
1666 for (i = disks; i--; ) {
1667 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1668 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
1669 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
1672 for (i = disks; i--; ) {
1673 struct r5dev *dev = &sh->dev[i];
1675 if (dev->written || i == pd_idx || i == qd_idx) {
1676 if (!discard && !test_bit(R5_SkipCopy, &dev->flags))
1677 set_bit(R5_UPTODATE, &dev->flags);
1679 set_bit(R5_WantFUA, &dev->flags);
1681 set_bit(R5_SyncIO, &dev->flags);
1685 if (sh->reconstruct_state == reconstruct_state_drain_run)
1686 sh->reconstruct_state = reconstruct_state_drain_result;
1687 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1688 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1690 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1691 sh->reconstruct_state = reconstruct_state_result;
1694 set_bit(STRIPE_HANDLE, &sh->state);
1699 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1700 struct dma_async_tx_descriptor *tx)
1702 int disks = sh->disks;
1703 struct page **xor_srcs;
1704 struct async_submit_ctl submit;
1705 int count, pd_idx = sh->pd_idx, i;
1706 struct page *xor_dest;
1708 unsigned long flags;
1710 struct stripe_head *head_sh = sh;
1713 pr_debug("%s: stripe %llu\n", __func__,
1714 (unsigned long long)sh->sector);
1716 for (i = 0; i < sh->disks; i++) {
1719 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1722 if (i >= sh->disks) {
1723 atomic_inc(&sh->count);
1724 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1725 ops_complete_reconstruct(sh);
1730 xor_srcs = to_addr_page(percpu, j);
1731 /* check if prexor is active which means only process blocks
1732 * that are part of a read-modify-write (written)
1734 if (head_sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1736 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1737 for (i = disks; i--; ) {
1738 struct r5dev *dev = &sh->dev[i];
1739 if (head_sh->dev[i].written)
1740 xor_srcs[count++] = dev->page;
1743 xor_dest = sh->dev[pd_idx].page;
1744 for (i = disks; i--; ) {
1745 struct r5dev *dev = &sh->dev[i];
1747 xor_srcs[count++] = dev->page;
1751 /* 1/ if we prexor'd then the dest is reused as a source
1752 * 2/ if we did not prexor then we are redoing the parity
1753 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1754 * for the synchronous xor case
1756 last_stripe = !head_sh->batch_head ||
1757 list_first_entry(&sh->batch_list,
1758 struct stripe_head, batch_list) == head_sh;
1760 flags = ASYNC_TX_ACK |
1761 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1763 atomic_inc(&head_sh->count);
1764 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh,
1765 to_addr_conv(sh, percpu, j));
1767 flags = prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST;
1768 init_async_submit(&submit, flags, tx, NULL, NULL,
1769 to_addr_conv(sh, percpu, j));
1772 if (unlikely(count == 1))
1773 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1775 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1778 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1785 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1786 struct dma_async_tx_descriptor *tx)
1788 struct async_submit_ctl submit;
1789 struct page **blocks;
1790 int count, i, j = 0;
1791 struct stripe_head *head_sh = sh;
1794 unsigned long txflags;
1796 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1798 for (i = 0; i < sh->disks; i++) {
1799 if (sh->pd_idx == i || sh->qd_idx == i)
1801 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1804 if (i >= sh->disks) {
1805 atomic_inc(&sh->count);
1806 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1807 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1808 ops_complete_reconstruct(sh);
1813 blocks = to_addr_page(percpu, j);
1815 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1816 synflags = SYNDROME_SRC_WRITTEN;
1817 txflags = ASYNC_TX_ACK | ASYNC_TX_PQ_XOR_DST;
1819 synflags = SYNDROME_SRC_ALL;
1820 txflags = ASYNC_TX_ACK;
1823 count = set_syndrome_sources(blocks, sh, synflags);
1824 last_stripe = !head_sh->batch_head ||
1825 list_first_entry(&sh->batch_list,
1826 struct stripe_head, batch_list) == head_sh;
1829 atomic_inc(&head_sh->count);
1830 init_async_submit(&submit, txflags, tx, ops_complete_reconstruct,
1831 head_sh, to_addr_conv(sh, percpu, j));
1833 init_async_submit(&submit, 0, tx, NULL, NULL,
1834 to_addr_conv(sh, percpu, j));
1835 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1838 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1844 static void ops_complete_check(void *stripe_head_ref)
1846 struct stripe_head *sh = stripe_head_ref;
1848 pr_debug("%s: stripe %llu\n", __func__,
1849 (unsigned long long)sh->sector);
1851 sh->check_state = check_state_check_result;
1852 set_bit(STRIPE_HANDLE, &sh->state);
1856 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1858 int disks = sh->disks;
1859 int pd_idx = sh->pd_idx;
1860 int qd_idx = sh->qd_idx;
1861 struct page *xor_dest;
1862 struct page **xor_srcs = to_addr_page(percpu, 0);
1863 struct dma_async_tx_descriptor *tx;
1864 struct async_submit_ctl submit;
1868 pr_debug("%s: stripe %llu\n", __func__,
1869 (unsigned long long)sh->sector);
1871 BUG_ON(sh->batch_head);
1873 xor_dest = sh->dev[pd_idx].page;
1874 xor_srcs[count++] = xor_dest;
1875 for (i = disks; i--; ) {
1876 if (i == pd_idx || i == qd_idx)
1878 xor_srcs[count++] = sh->dev[i].page;
1881 init_async_submit(&submit, 0, NULL, NULL, NULL,
1882 to_addr_conv(sh, percpu, 0));
1883 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1884 &sh->ops.zero_sum_result, &submit);
1886 atomic_inc(&sh->count);
1887 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1888 tx = async_trigger_callback(&submit);
1891 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1893 struct page **srcs = to_addr_page(percpu, 0);
1894 struct async_submit_ctl submit;
1897 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1898 (unsigned long long)sh->sector, checkp);
1900 BUG_ON(sh->batch_head);
1901 count = set_syndrome_sources(srcs, sh, SYNDROME_SRC_ALL);
1905 atomic_inc(&sh->count);
1906 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1907 sh, to_addr_conv(sh, percpu, 0));
1908 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1909 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1912 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1914 int overlap_clear = 0, i, disks = sh->disks;
1915 struct dma_async_tx_descriptor *tx = NULL;
1916 struct r5conf *conf = sh->raid_conf;
1917 int level = conf->level;
1918 struct raid5_percpu *percpu;
1922 percpu = per_cpu_ptr(conf->percpu, cpu);
1923 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1924 ops_run_biofill(sh);
1928 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1930 tx = ops_run_compute5(sh, percpu);
1932 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1933 tx = ops_run_compute6_1(sh, percpu);
1935 tx = ops_run_compute6_2(sh, percpu);
1937 /* terminate the chain if reconstruct is not set to be run */
1938 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1942 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) {
1944 tx = ops_run_prexor5(sh, percpu, tx);
1946 tx = ops_run_prexor6(sh, percpu, tx);
1949 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1950 tx = ops_run_biodrain(sh, tx);
1954 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1956 ops_run_reconstruct5(sh, percpu, tx);
1958 ops_run_reconstruct6(sh, percpu, tx);
1961 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1962 if (sh->check_state == check_state_run)
1963 ops_run_check_p(sh, percpu);
1964 else if (sh->check_state == check_state_run_q)
1965 ops_run_check_pq(sh, percpu, 0);
1966 else if (sh->check_state == check_state_run_pq)
1967 ops_run_check_pq(sh, percpu, 1);
1972 if (overlap_clear && !sh->batch_head)
1973 for (i = disks; i--; ) {
1974 struct r5dev *dev = &sh->dev[i];
1975 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1976 wake_up(&sh->raid_conf->wait_for_overlap);
1981 static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp)
1983 struct stripe_head *sh;
1985 sh = kmem_cache_zalloc(sc, gfp);
1987 spin_lock_init(&sh->stripe_lock);
1988 spin_lock_init(&sh->batch_lock);
1989 INIT_LIST_HEAD(&sh->batch_list);
1990 INIT_LIST_HEAD(&sh->lru);
1991 atomic_set(&sh->count, 1);
1995 static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
1997 struct stripe_head *sh;
1999 sh = alloc_stripe(conf->slab_cache, gfp);
2003 sh->raid_conf = conf;
2005 if (grow_buffers(sh, gfp)) {
2007 kmem_cache_free(conf->slab_cache, sh);
2010 sh->hash_lock_index =
2011 conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
2012 /* we just created an active stripe so... */
2013 atomic_inc(&conf->active_stripes);
2016 conf->max_nr_stripes++;
2020 static int grow_stripes(struct r5conf *conf, int num)
2022 struct kmem_cache *sc;
2023 int devs = max(conf->raid_disks, conf->previous_raid_disks);
2025 if (conf->mddev->gendisk)
2026 sprintf(conf->cache_name[0],
2027 "raid%d-%s", conf->level, mdname(conf->mddev));
2029 sprintf(conf->cache_name[0],
2030 "raid%d-%p", conf->level, conf->mddev);
2031 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
2033 conf->active_name = 0;
2034 sc = kmem_cache_create(conf->cache_name[conf->active_name],
2035 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
2039 conf->slab_cache = sc;
2040 conf->pool_size = devs;
2042 if (!grow_one_stripe(conf, GFP_KERNEL))
2049 * scribble_len - return the required size of the scribble region
2050 * @num - total number of disks in the array
2052 * The size must be enough to contain:
2053 * 1/ a struct page pointer for each device in the array +2
2054 * 2/ room to convert each entry in (1) to its corresponding dma
2055 * (dma_map_page()) or page (page_address()) address.
2057 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
2058 * calculate over all devices (not just the data blocks), using zeros in place
2059 * of the P and Q blocks.
2061 static struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags)
2063 struct flex_array *ret;
2066 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
2067 ret = flex_array_alloc(len, cnt, flags);
2070 /* always prealloc all elements, so no locking is required */
2071 if (flex_array_prealloc(ret, 0, cnt, flags)) {
2072 flex_array_free(ret);
2078 static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
2083 mddev_suspend(conf->mddev);
2085 for_each_present_cpu(cpu) {
2086 struct raid5_percpu *percpu;
2087 struct flex_array *scribble;
2089 percpu = per_cpu_ptr(conf->percpu, cpu);
2090 scribble = scribble_alloc(new_disks,
2091 new_sectors / STRIPE_SECTORS,
2095 flex_array_free(percpu->scribble);
2096 percpu->scribble = scribble;
2103 mddev_resume(conf->mddev);
2107 static int resize_stripes(struct r5conf *conf, int newsize)
2109 /* Make all the stripes able to hold 'newsize' devices.
2110 * New slots in each stripe get 'page' set to a new page.
2112 * This happens in stages:
2113 * 1/ create a new kmem_cache and allocate the required number of
2115 * 2/ gather all the old stripe_heads and transfer the pages across
2116 * to the new stripe_heads. This will have the side effect of
2117 * freezing the array as once all stripe_heads have been collected,
2118 * no IO will be possible. Old stripe heads are freed once their
2119 * pages have been transferred over, and the old kmem_cache is
2120 * freed when all stripes are done.
2121 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
2122 * we simple return a failre status - no need to clean anything up.
2123 * 4/ allocate new pages for the new slots in the new stripe_heads.
2124 * If this fails, we don't bother trying the shrink the
2125 * stripe_heads down again, we just leave them as they are.
2126 * As each stripe_head is processed the new one is released into
2129 * Once step2 is started, we cannot afford to wait for a write,
2130 * so we use GFP_NOIO allocations.
2132 struct stripe_head *osh, *nsh;
2133 LIST_HEAD(newstripes);
2134 struct disk_info *ndisks;
2136 struct kmem_cache *sc;
2140 if (newsize <= conf->pool_size)
2141 return 0; /* never bother to shrink */
2143 err = md_allow_write(conf->mddev);
2148 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
2149 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
2154 for (i = conf->max_nr_stripes; i; i--) {
2155 nsh = alloc_stripe(sc, GFP_KERNEL);
2159 nsh->raid_conf = conf;
2160 list_add(&nsh->lru, &newstripes);
2163 /* didn't get enough, give up */
2164 while (!list_empty(&newstripes)) {
2165 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2166 list_del(&nsh->lru);
2167 kmem_cache_free(sc, nsh);
2169 kmem_cache_destroy(sc);
2172 /* Step 2 - Must use GFP_NOIO now.
2173 * OK, we have enough stripes, start collecting inactive
2174 * stripes and copying them over
2178 list_for_each_entry(nsh, &newstripes, lru) {
2179 lock_device_hash_lock(conf, hash);
2180 wait_event_cmd(conf->wait_for_stripe,
2181 !list_empty(conf->inactive_list + hash),
2182 unlock_device_hash_lock(conf, hash),
2183 lock_device_hash_lock(conf, hash));
2184 osh = get_free_stripe(conf, hash);
2185 unlock_device_hash_lock(conf, hash);
2187 for(i=0; i<conf->pool_size; i++) {
2188 nsh->dev[i].page = osh->dev[i].page;
2189 nsh->dev[i].orig_page = osh->dev[i].page;
2191 nsh->hash_lock_index = hash;
2192 kmem_cache_free(conf->slab_cache, osh);
2194 if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +
2195 !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
2200 kmem_cache_destroy(conf->slab_cache);
2203 * At this point, we are holding all the stripes so the array
2204 * is completely stalled, so now is a good time to resize
2205 * conf->disks and the scribble region
2207 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
2209 for (i=0; i<conf->raid_disks; i++)
2210 ndisks[i] = conf->disks[i];
2212 conf->disks = ndisks;
2216 /* Step 4, return new stripes to service */
2217 while(!list_empty(&newstripes)) {
2218 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2219 list_del_init(&nsh->lru);
2221 for (i=conf->raid_disks; i < newsize; i++)
2222 if (nsh->dev[i].page == NULL) {
2223 struct page *p = alloc_page(GFP_NOIO);
2224 nsh->dev[i].page = p;
2225 nsh->dev[i].orig_page = p;
2229 release_stripe(nsh);
2231 /* critical section pass, GFP_NOIO no longer needed */
2233 conf->slab_cache = sc;
2234 conf->active_name = 1-conf->active_name;
2236 conf->pool_size = newsize;
2240 static int drop_one_stripe(struct r5conf *conf)
2242 struct stripe_head *sh;
2243 int hash = (conf->max_nr_stripes - 1) % NR_STRIPE_HASH_LOCKS;
2245 spin_lock_irq(conf->hash_locks + hash);
2246 sh = get_free_stripe(conf, hash);
2247 spin_unlock_irq(conf->hash_locks + hash);
2250 BUG_ON(atomic_read(&sh->count));
2252 kmem_cache_free(conf->slab_cache, sh);
2253 atomic_dec(&conf->active_stripes);
2254 conf->max_nr_stripes--;
2258 static void shrink_stripes(struct r5conf *conf)
2260 while (conf->max_nr_stripes &&
2261 drop_one_stripe(conf))
2264 if (conf->slab_cache)
2265 kmem_cache_destroy(conf->slab_cache);
2266 conf->slab_cache = NULL;
2269 static void raid5_end_read_request(struct bio * bi, int error)
2271 struct stripe_head *sh = bi->bi_private;
2272 struct r5conf *conf = sh->raid_conf;
2273 int disks = sh->disks, i;
2274 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
2275 char b[BDEVNAME_SIZE];
2276 struct md_rdev *rdev = NULL;
2279 for (i=0 ; i<disks; i++)
2280 if (bi == &sh->dev[i].req)
2283 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
2284 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2290 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2291 /* If replacement finished while this request was outstanding,
2292 * 'replacement' might be NULL already.
2293 * In that case it moved down to 'rdev'.
2294 * rdev is not removed until all requests are finished.
2296 rdev = conf->disks[i].replacement;
2298 rdev = conf->disks[i].rdev;
2300 if (use_new_offset(conf, sh))
2301 s = sh->sector + rdev->new_data_offset;
2303 s = sh->sector + rdev->data_offset;
2305 set_bit(R5_UPTODATE, &sh->dev[i].flags);
2306 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2307 /* Note that this cannot happen on a
2308 * replacement device. We just fail those on
2313 "md/raid:%s: read error corrected"
2314 " (%lu sectors at %llu on %s)\n",
2315 mdname(conf->mddev), STRIPE_SECTORS,
2316 (unsigned long long)s,
2317 bdevname(rdev->bdev, b));
2318 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2319 clear_bit(R5_ReadError, &sh->dev[i].flags);
2320 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2321 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2322 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2324 if (atomic_read(&rdev->read_errors))
2325 atomic_set(&rdev->read_errors, 0);
2327 const char *bdn = bdevname(rdev->bdev, b);
2331 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
2332 atomic_inc(&rdev->read_errors);
2333 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2336 "md/raid:%s: read error on replacement device "
2337 "(sector %llu on %s).\n",
2338 mdname(conf->mddev),
2339 (unsigned long long)s,
2341 else if (conf->mddev->degraded >= conf->max_degraded) {
2345 "md/raid:%s: read error not correctable "
2346 "(sector %llu on %s).\n",
2347 mdname(conf->mddev),
2348 (unsigned long long)s,
2350 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
2355 "md/raid:%s: read error NOT corrected!! "
2356 "(sector %llu on %s).\n",
2357 mdname(conf->mddev),
2358 (unsigned long long)s,
2360 } else if (atomic_read(&rdev->read_errors)
2361 > conf->max_nr_stripes)
2363 "md/raid:%s: Too many read errors, failing device %s.\n",
2364 mdname(conf->mddev), bdn);
2367 if (set_bad && test_bit(In_sync, &rdev->flags)
2368 && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2371 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
2372 set_bit(R5_ReadError, &sh->dev[i].flags);
2373 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2375 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2377 clear_bit(R5_ReadError, &sh->dev[i].flags);
2378 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2380 && test_bit(In_sync, &rdev->flags)
2381 && rdev_set_badblocks(
2382 rdev, sh->sector, STRIPE_SECTORS, 0)))
2383 md_error(conf->mddev, rdev);
2386 rdev_dec_pending(rdev, conf->mddev);
2387 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2388 set_bit(STRIPE_HANDLE, &sh->state);
2392 static void raid5_end_write_request(struct bio *bi, int error)
2394 struct stripe_head *sh = bi->bi_private;
2395 struct r5conf *conf = sh->raid_conf;
2396 int disks = sh->disks, i;
2397 struct md_rdev *uninitialized_var(rdev);
2398 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
2401 int replacement = 0;
2403 for (i = 0 ; i < disks; i++) {
2404 if (bi == &sh->dev[i].req) {
2405 rdev = conf->disks[i].rdev;
2408 if (bi == &sh->dev[i].rreq) {
2409 rdev = conf->disks[i].replacement;
2413 /* rdev was removed and 'replacement'
2414 * replaced it. rdev is not removed
2415 * until all requests are finished.
2417 rdev = conf->disks[i].rdev;
2421 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
2422 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2431 md_error(conf->mddev, rdev);
2432 else if (is_badblock(rdev, sh->sector,
2434 &first_bad, &bad_sectors))
2435 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
2438 set_bit(STRIPE_DEGRADED, &sh->state);
2439 set_bit(WriteErrorSeen, &rdev->flags);
2440 set_bit(R5_WriteError, &sh->dev[i].flags);
2441 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2442 set_bit(MD_RECOVERY_NEEDED,
2443 &rdev->mddev->recovery);
2444 } else if (is_badblock(rdev, sh->sector,
2446 &first_bad, &bad_sectors)) {
2447 set_bit(R5_MadeGood, &sh->dev[i].flags);
2448 if (test_bit(R5_ReadError, &sh->dev[i].flags))
2449 /* That was a successful write so make
2450 * sure it looks like we already did
2453 set_bit(R5_ReWrite, &sh->dev[i].flags);
2456 rdev_dec_pending(rdev, conf->mddev);
2458 if (sh->batch_head && !uptodate && !replacement)
2459 set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state);
2461 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
2462 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2463 set_bit(STRIPE_HANDLE, &sh->state);
2466 if (sh->batch_head && sh != sh->batch_head)
2467 release_stripe(sh->batch_head);
2470 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
2472 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
2474 struct r5dev *dev = &sh->dev[i];
2476 bio_init(&dev->req);
2477 dev->req.bi_io_vec = &dev->vec;
2478 dev->req.bi_max_vecs = 1;
2479 dev->req.bi_private = sh;
2481 bio_init(&dev->rreq);
2482 dev->rreq.bi_io_vec = &dev->rvec;
2483 dev->rreq.bi_max_vecs = 1;
2484 dev->rreq.bi_private = sh;
2487 dev->sector = compute_blocknr(sh, i, previous);
2490 static void error(struct mddev *mddev, struct md_rdev *rdev)
2492 char b[BDEVNAME_SIZE];
2493 struct r5conf *conf = mddev->private;
2494 unsigned long flags;
2495 pr_debug("raid456: error called\n");
2497 spin_lock_irqsave(&conf->device_lock, flags);
2498 clear_bit(In_sync, &rdev->flags);
2499 mddev->degraded = calc_degraded(conf);
2500 spin_unlock_irqrestore(&conf->device_lock, flags);
2501 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2503 set_bit(Blocked, &rdev->flags);
2504 set_bit(Faulty, &rdev->flags);
2505 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2507 "md/raid:%s: Disk failure on %s, disabling device.\n"
2508 "md/raid:%s: Operation continuing on %d devices.\n",
2510 bdevname(rdev->bdev, b),
2512 conf->raid_disks - mddev->degraded);
2516 * Input: a 'big' sector number,
2517 * Output: index of the data and parity disk, and the sector # in them.
2519 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
2520 int previous, int *dd_idx,
2521 struct stripe_head *sh)
2523 sector_t stripe, stripe2;
2524 sector_t chunk_number;
2525 unsigned int chunk_offset;
2528 sector_t new_sector;
2529 int algorithm = previous ? conf->prev_algo
2531 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2532 : conf->chunk_sectors;
2533 int raid_disks = previous ? conf->previous_raid_disks
2535 int data_disks = raid_disks - conf->max_degraded;
2537 /* First compute the information on this sector */
2540 * Compute the chunk number and the sector offset inside the chunk
2542 chunk_offset = sector_div(r_sector, sectors_per_chunk);
2543 chunk_number = r_sector;
2546 * Compute the stripe number
2548 stripe = chunk_number;
2549 *dd_idx = sector_div(stripe, data_disks);
2552 * Select the parity disk based on the user selected algorithm.
2554 pd_idx = qd_idx = -1;
2555 switch(conf->level) {
2557 pd_idx = data_disks;
2560 switch (algorithm) {
2561 case ALGORITHM_LEFT_ASYMMETRIC:
2562 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2563 if (*dd_idx >= pd_idx)
2566 case ALGORITHM_RIGHT_ASYMMETRIC:
2567 pd_idx = sector_div(stripe2, raid_disks);
2568 if (*dd_idx >= pd_idx)
2571 case ALGORITHM_LEFT_SYMMETRIC:
2572 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2573 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2575 case ALGORITHM_RIGHT_SYMMETRIC:
2576 pd_idx = sector_div(stripe2, raid_disks);
2577 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2579 case ALGORITHM_PARITY_0:
2583 case ALGORITHM_PARITY_N:
2584 pd_idx = data_disks;
2592 switch (algorithm) {
2593 case ALGORITHM_LEFT_ASYMMETRIC:
2594 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2595 qd_idx = pd_idx + 1;
2596 if (pd_idx == raid_disks-1) {
2597 (*dd_idx)++; /* Q D D D P */
2599 } else if (*dd_idx >= pd_idx)
2600 (*dd_idx) += 2; /* D D P Q D */
2602 case ALGORITHM_RIGHT_ASYMMETRIC:
2603 pd_idx = sector_div(stripe2, raid_disks);
2604 qd_idx = pd_idx + 1;
2605 if (pd_idx == raid_disks-1) {
2606 (*dd_idx)++; /* Q D D D P */
2608 } else if (*dd_idx >= pd_idx)
2609 (*dd_idx) += 2; /* D D P Q D */
2611 case ALGORITHM_LEFT_SYMMETRIC:
2612 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2613 qd_idx = (pd_idx + 1) % raid_disks;
2614 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2616 case ALGORITHM_RIGHT_SYMMETRIC:
2617 pd_idx = sector_div(stripe2, raid_disks);
2618 qd_idx = (pd_idx + 1) % raid_disks;
2619 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2622 case ALGORITHM_PARITY_0:
2627 case ALGORITHM_PARITY_N:
2628 pd_idx = data_disks;
2629 qd_idx = data_disks + 1;
2632 case ALGORITHM_ROTATING_ZERO_RESTART:
2633 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2634 * of blocks for computing Q is different.
2636 pd_idx = sector_div(stripe2, raid_disks);
2637 qd_idx = pd_idx + 1;
2638 if (pd_idx == raid_disks-1) {
2639 (*dd_idx)++; /* Q D D D P */
2641 } else if (*dd_idx >= pd_idx)
2642 (*dd_idx) += 2; /* D D P Q D */
2646 case ALGORITHM_ROTATING_N_RESTART:
2647 /* Same a left_asymmetric, by first stripe is
2648 * D D D P Q rather than
2652 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2653 qd_idx = pd_idx + 1;
2654 if (pd_idx == raid_disks-1) {
2655 (*dd_idx)++; /* Q D D D P */
2657 } else if (*dd_idx >= pd_idx)
2658 (*dd_idx) += 2; /* D D P Q D */
2662 case ALGORITHM_ROTATING_N_CONTINUE:
2663 /* Same as left_symmetric but Q is before P */
2664 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2665 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2666 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2670 case ALGORITHM_LEFT_ASYMMETRIC_6:
2671 /* RAID5 left_asymmetric, with Q on last device */
2672 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2673 if (*dd_idx >= pd_idx)
2675 qd_idx = raid_disks - 1;
2678 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2679 pd_idx = sector_div(stripe2, raid_disks-1);
2680 if (*dd_idx >= pd_idx)
2682 qd_idx = raid_disks - 1;
2685 case ALGORITHM_LEFT_SYMMETRIC_6:
2686 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2687 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2688 qd_idx = raid_disks - 1;
2691 case ALGORITHM_RIGHT_SYMMETRIC_6:
2692 pd_idx = sector_div(stripe2, raid_disks-1);
2693 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2694 qd_idx = raid_disks - 1;
2697 case ALGORITHM_PARITY_0_6:
2700 qd_idx = raid_disks - 1;
2710 sh->pd_idx = pd_idx;
2711 sh->qd_idx = qd_idx;
2712 sh->ddf_layout = ddf_layout;
2715 * Finally, compute the new sector number
2717 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2721 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
2723 struct r5conf *conf = sh->raid_conf;
2724 int raid_disks = sh->disks;
2725 int data_disks = raid_disks - conf->max_degraded;
2726 sector_t new_sector = sh->sector, check;
2727 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2728 : conf->chunk_sectors;
2729 int algorithm = previous ? conf->prev_algo
2733 sector_t chunk_number;
2734 int dummy1, dd_idx = i;
2736 struct stripe_head sh2;
2738 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2739 stripe = new_sector;
2741 if (i == sh->pd_idx)
2743 switch(conf->level) {
2746 switch (algorithm) {
2747 case ALGORITHM_LEFT_ASYMMETRIC:
2748 case ALGORITHM_RIGHT_ASYMMETRIC:
2752 case ALGORITHM_LEFT_SYMMETRIC:
2753 case ALGORITHM_RIGHT_SYMMETRIC:
2756 i -= (sh->pd_idx + 1);
2758 case ALGORITHM_PARITY_0:
2761 case ALGORITHM_PARITY_N:
2768 if (i == sh->qd_idx)
2769 return 0; /* It is the Q disk */
2770 switch (algorithm) {
2771 case ALGORITHM_LEFT_ASYMMETRIC:
2772 case ALGORITHM_RIGHT_ASYMMETRIC:
2773 case ALGORITHM_ROTATING_ZERO_RESTART:
2774 case ALGORITHM_ROTATING_N_RESTART:
2775 if (sh->pd_idx == raid_disks-1)
2776 i--; /* Q D D D P */
2777 else if (i > sh->pd_idx)
2778 i -= 2; /* D D P Q D */
2780 case ALGORITHM_LEFT_SYMMETRIC:
2781 case ALGORITHM_RIGHT_SYMMETRIC:
2782 if (sh->pd_idx == raid_disks-1)
2783 i--; /* Q D D D P */
2788 i -= (sh->pd_idx + 2);
2791 case ALGORITHM_PARITY_0:
2794 case ALGORITHM_PARITY_N:
2796 case ALGORITHM_ROTATING_N_CONTINUE:
2797 /* Like left_symmetric, but P is before Q */
2798 if (sh->pd_idx == 0)
2799 i--; /* P D D D Q */
2804 i -= (sh->pd_idx + 1);
2807 case ALGORITHM_LEFT_ASYMMETRIC_6:
2808 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2812 case ALGORITHM_LEFT_SYMMETRIC_6:
2813 case ALGORITHM_RIGHT_SYMMETRIC_6:
2815 i += data_disks + 1;
2816 i -= (sh->pd_idx + 1);
2818 case ALGORITHM_PARITY_0_6:
2827 chunk_number = stripe * data_disks + i;
2828 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2830 check = raid5_compute_sector(conf, r_sector,
2831 previous, &dummy1, &sh2);
2832 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2833 || sh2.qd_idx != sh->qd_idx) {
2834 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2835 mdname(conf->mddev));
2842 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2843 int rcw, int expand)
2845 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx, disks = sh->disks;
2846 struct r5conf *conf = sh->raid_conf;
2847 int level = conf->level;
2851 for (i = disks; i--; ) {
2852 struct r5dev *dev = &sh->dev[i];
2855 set_bit(R5_LOCKED, &dev->flags);
2856 set_bit(R5_Wantdrain, &dev->flags);
2858 clear_bit(R5_UPTODATE, &dev->flags);
2862 /* if we are not expanding this is a proper write request, and
2863 * there will be bios with new data to be drained into the
2868 /* False alarm, nothing to do */
2870 sh->reconstruct_state = reconstruct_state_drain_run;
2871 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2873 sh->reconstruct_state = reconstruct_state_run;
2875 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2877 if (s->locked + conf->max_degraded == disks)
2878 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2879 atomic_inc(&conf->pending_full_writes);
2881 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2882 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2883 BUG_ON(level == 6 &&
2884 (!(test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags) ||
2885 test_bit(R5_Wantcompute, &sh->dev[qd_idx].flags))));
2887 for (i = disks; i--; ) {
2888 struct r5dev *dev = &sh->dev[i];
2889 if (i == pd_idx || i == qd_idx)
2893 (test_bit(R5_UPTODATE, &dev->flags) ||
2894 test_bit(R5_Wantcompute, &dev->flags))) {
2895 set_bit(R5_Wantdrain, &dev->flags);
2896 set_bit(R5_LOCKED, &dev->flags);
2897 clear_bit(R5_UPTODATE, &dev->flags);
2902 /* False alarm - nothing to do */
2904 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2905 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2906 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2907 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2910 /* keep the parity disk(s) locked while asynchronous operations
2913 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2914 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2918 int qd_idx = sh->qd_idx;
2919 struct r5dev *dev = &sh->dev[qd_idx];
2921 set_bit(R5_LOCKED, &dev->flags);
2922 clear_bit(R5_UPTODATE, &dev->flags);
2926 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2927 __func__, (unsigned long long)sh->sector,
2928 s->locked, s->ops_request);
2932 * Each stripe/dev can have one or more bion attached.
2933 * toread/towrite point to the first in a chain.
2934 * The bi_next chain must be in order.
2936 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
2937 int forwrite, int previous)
2940 struct r5conf *conf = sh->raid_conf;
2943 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2944 (unsigned long long)bi->bi_iter.bi_sector,
2945 (unsigned long long)sh->sector);
2948 * If several bio share a stripe. The bio bi_phys_segments acts as a
2949 * reference count to avoid race. The reference count should already be
2950 * increased before this function is called (for example, in
2951 * make_request()), so other bio sharing this stripe will not free the
2952 * stripe. If a stripe is owned by one stripe, the stripe lock will
2955 spin_lock_irq(&sh->stripe_lock);
2956 /* Don't allow new IO added to stripes in batch list */
2960 bip = &sh->dev[dd_idx].towrite;
2964 bip = &sh->dev[dd_idx].toread;
2965 while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
2966 if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
2968 bip = & (*bip)->bi_next;
2970 if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
2973 if (!forwrite || previous)
2974 clear_bit(STRIPE_BATCH_READY, &sh->state);
2976 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2980 raid5_inc_bi_active_stripes(bi);
2983 /* check if page is covered */
2984 sector_t sector = sh->dev[dd_idx].sector;
2985 for (bi=sh->dev[dd_idx].towrite;
2986 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2987 bi && bi->bi_iter.bi_sector <= sector;
2988 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2989 if (bio_end_sector(bi) >= sector)
2990 sector = bio_end_sector(bi);
2992 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2993 if (!test_and_set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags))
2994 sh->overwrite_disks++;
2997 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2998 (unsigned long long)(*bip)->bi_iter.bi_sector,
2999 (unsigned long long)sh->sector, dd_idx);
3001 if (conf->mddev->bitmap && firstwrite) {
3002 /* Cannot hold spinlock over bitmap_startwrite,
3003 * but must ensure this isn't added to a batch until
3004 * we have added to the bitmap and set bm_seq.
3005 * So set STRIPE_BITMAP_PENDING to prevent
3007 * If multiple add_stripe_bio() calls race here they
3008 * much all set STRIPE_BITMAP_PENDING. So only the first one
3009 * to complete "bitmap_startwrite" gets to set
3010 * STRIPE_BIT_DELAY. This is important as once a stripe
3011 * is added to a batch, STRIPE_BIT_DELAY cannot be changed
3014 set_bit(STRIPE_BITMAP_PENDING, &sh->state);
3015 spin_unlock_irq(&sh->stripe_lock);
3016 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
3018 spin_lock_irq(&sh->stripe_lock);
3019 clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
3020 if (!sh->batch_head) {
3021 sh->bm_seq = conf->seq_flush+1;
3022 set_bit(STRIPE_BIT_DELAY, &sh->state);
3025 spin_unlock_irq(&sh->stripe_lock);
3027 if (stripe_can_batch(sh))
3028 stripe_add_to_batch_list(conf, sh);
3032 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
3033 spin_unlock_irq(&sh->stripe_lock);
3037 static void end_reshape(struct r5conf *conf);
3039 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
3040 struct stripe_head *sh)
3042 int sectors_per_chunk =
3043 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
3045 int chunk_offset = sector_div(stripe, sectors_per_chunk);
3046 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
3048 raid5_compute_sector(conf,
3049 stripe * (disks - conf->max_degraded)
3050 *sectors_per_chunk + chunk_offset,
3056 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
3057 struct stripe_head_state *s, int disks,
3058 struct bio **return_bi)
3061 BUG_ON(sh->batch_head);
3062 for (i = disks; i--; ) {
3066 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
3067 struct md_rdev *rdev;
3069 rdev = rcu_dereference(conf->disks[i].rdev);
3070 if (rdev && test_bit(In_sync, &rdev->flags))
3071 atomic_inc(&rdev->nr_pending);
3076 if (!rdev_set_badblocks(
3080 md_error(conf->mddev, rdev);
3081 rdev_dec_pending(rdev, conf->mddev);
3084 spin_lock_irq(&sh->stripe_lock);
3085 /* fail all writes first */
3086 bi = sh->dev[i].towrite;
3087 sh->dev[i].towrite = NULL;
3088 sh->overwrite_disks = 0;
3089 spin_unlock_irq(&sh->stripe_lock);
3093 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3094 wake_up(&conf->wait_for_overlap);
3096 while (bi && bi->bi_iter.bi_sector <
3097 sh->dev[i].sector + STRIPE_SECTORS) {
3098 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
3099 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3100 if (!raid5_dec_bi_active_stripes(bi)) {
3101 md_write_end(conf->mddev);
3102 bi->bi_next = *return_bi;
3108 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3109 STRIPE_SECTORS, 0, 0);
3111 /* and fail all 'written' */
3112 bi = sh->dev[i].written;
3113 sh->dev[i].written = NULL;
3114 if (test_and_clear_bit(R5_SkipCopy, &sh->dev[i].flags)) {
3115 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
3116 sh->dev[i].page = sh->dev[i].orig_page;
3119 if (bi) bitmap_end = 1;
3120 while (bi && bi->bi_iter.bi_sector <
3121 sh->dev[i].sector + STRIPE_SECTORS) {
3122 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
3123 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3124 if (!raid5_dec_bi_active_stripes(bi)) {
3125 md_write_end(conf->mddev);
3126 bi->bi_next = *return_bi;
3132 /* fail any reads if this device is non-operational and
3133 * the data has not reached the cache yet.
3135 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
3136 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
3137 test_bit(R5_ReadError, &sh->dev[i].flags))) {
3138 spin_lock_irq(&sh->stripe_lock);
3139 bi = sh->dev[i].toread;
3140 sh->dev[i].toread = NULL;
3141 spin_unlock_irq(&sh->stripe_lock);
3142 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3143 wake_up(&conf->wait_for_overlap);
3144 while (bi && bi->bi_iter.bi_sector <
3145 sh->dev[i].sector + STRIPE_SECTORS) {
3146 struct bio *nextbi =
3147 r5_next_bio(bi, sh->dev[i].sector);
3148 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3149 if (!raid5_dec_bi_active_stripes(bi)) {
3150 bi->bi_next = *return_bi;
3157 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3158 STRIPE_SECTORS, 0, 0);
3159 /* If we were in the middle of a write the parity block might
3160 * still be locked - so just clear all R5_LOCKED flags
3162 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3165 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3166 if (atomic_dec_and_test(&conf->pending_full_writes))
3167 md_wakeup_thread(conf->mddev->thread);
3171 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
3172 struct stripe_head_state *s)
3177 BUG_ON(sh->batch_head);
3178 clear_bit(STRIPE_SYNCING, &sh->state);
3179 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3180 wake_up(&conf->wait_for_overlap);
3183 /* There is nothing more to do for sync/check/repair.
3184 * Don't even need to abort as that is handled elsewhere
3185 * if needed, and not always wanted e.g. if there is a known
3187 * For recover/replace we need to record a bad block on all
3188 * non-sync devices, or abort the recovery
3190 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
3191 /* During recovery devices cannot be removed, so
3192 * locking and refcounting of rdevs is not needed
3194 for (i = 0; i < conf->raid_disks; i++) {
3195 struct md_rdev *rdev = conf->disks[i].rdev;
3197 && !test_bit(Faulty, &rdev->flags)
3198 && !test_bit(In_sync, &rdev->flags)
3199 && !rdev_set_badblocks(rdev, sh->sector,
3202 rdev = conf->disks[i].replacement;
3204 && !test_bit(Faulty, &rdev->flags)
3205 && !test_bit(In_sync, &rdev->flags)
3206 && !rdev_set_badblocks(rdev, sh->sector,
3211 conf->recovery_disabled =
3212 conf->mddev->recovery_disabled;
3214 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
3217 static int want_replace(struct stripe_head *sh, int disk_idx)
3219 struct md_rdev *rdev;
3221 /* Doing recovery so rcu locking not required */
3222 rdev = sh->raid_conf->disks[disk_idx].replacement;
3224 && !test_bit(Faulty, &rdev->flags)
3225 && !test_bit(In_sync, &rdev->flags)
3226 && (rdev->recovery_offset <= sh->sector
3227 || rdev->mddev->recovery_cp <= sh->sector))
3233 /* fetch_block - checks the given member device to see if its data needs
3234 * to be read or computed to satisfy a request.
3236 * Returns 1 when no more member devices need to be checked, otherwise returns
3237 * 0 to tell the loop in handle_stripe_fill to continue
3240 static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,
3241 int disk_idx, int disks)
3243 struct r5dev *dev = &sh->dev[disk_idx];
3244 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
3245 &sh->dev[s->failed_num[1]] };
3249 if (test_bit(R5_LOCKED, &dev->flags) ||
3250 test_bit(R5_UPTODATE, &dev->flags))
3251 /* No point reading this as we already have it or have
3252 * decided to get it.
3257 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)))
3258 /* We need this block to directly satisfy a request */
3261 if (s->syncing || s->expanding ||
3262 (s->replacing && want_replace(sh, disk_idx)))
3263 /* When syncing, or expanding we read everything.
3264 * When replacing, we need the replaced block.
3268 if ((s->failed >= 1 && fdev[0]->toread) ||
3269 (s->failed >= 2 && fdev[1]->toread))
3270 /* If we want to read from a failed device, then
3271 * we need to actually read every other device.
3275 /* Sometimes neither read-modify-write nor reconstruct-write
3276 * cycles can work. In those cases we read every block we
3277 * can. Then the parity-update is certain to have enough to
3279 * This can only be a problem when we need to write something,
3280 * and some device has failed. If either of those tests
3281 * fail we need look no further.
3283 if (!s->failed || !s->to_write)
3286 if (test_bit(R5_Insync, &dev->flags) &&
3287 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3288 /* Pre-reads at not permitted until after short delay
3289 * to gather multiple requests. However if this
3290 * device is no Insync, the block could only be be computed
3291 * and there is no need to delay that.
3295 for (i = 0; i < s->failed; i++) {
3296 if (fdev[i]->towrite &&
3297 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3298 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3299 /* If we have a partial write to a failed
3300 * device, then we will need to reconstruct
3301 * the content of that device, so all other
3302 * devices must be read.
3307 /* If we are forced to do a reconstruct-write, either because
3308 * the current RAID6 implementation only supports that, or
3309 * or because parity cannot be trusted and we are currently
3310 * recovering it, there is extra need to be careful.
3311 * If one of the devices that we would need to read, because
3312 * it is not being overwritten (and maybe not written at all)
3313 * is missing/faulty, then we need to read everything we can.
3315 if (sh->raid_conf->level != 6 &&
3316 sh->sector < sh->raid_conf->mddev->recovery_cp)
3317 /* reconstruct-write isn't being forced */
3319 for (i = 0; i < s->failed; i++) {
3320 if (s->failed_num[i] != sh->pd_idx &&
3321 s->failed_num[i] != sh->qd_idx &&
3322 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3323 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3330 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
3331 int disk_idx, int disks)
3333 struct r5dev *dev = &sh->dev[disk_idx];
3335 /* is the data in this block needed, and can we get it? */
3336 if (need_this_block(sh, s, disk_idx, disks)) {
3337 /* we would like to get this block, possibly by computing it,
3338 * otherwise read it if the backing disk is insync
3340 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
3341 BUG_ON(test_bit(R5_Wantread, &dev->flags));
3342 BUG_ON(sh->batch_head);
3343 if ((s->uptodate == disks - 1) &&
3344 (s->failed && (disk_idx == s->failed_num[0] ||
3345 disk_idx == s->failed_num[1]))) {
3346 /* have disk failed, and we're requested to fetch it;
3349 pr_debug("Computing stripe %llu block %d\n",
3350 (unsigned long long)sh->sector, disk_idx);
3351 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3352 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3353 set_bit(R5_Wantcompute, &dev->flags);
3354 sh->ops.target = disk_idx;
3355 sh->ops.target2 = -1; /* no 2nd target */
3357 /* Careful: from this point on 'uptodate' is in the eye
3358 * of raid_run_ops which services 'compute' operations
3359 * before writes. R5_Wantcompute flags a block that will
3360 * be R5_UPTODATE by the time it is needed for a
3361 * subsequent operation.
3365 } else if (s->uptodate == disks-2 && s->failed >= 2) {
3366 /* Computing 2-failure is *very* expensive; only
3367 * do it if failed >= 2
3370 for (other = disks; other--; ) {
3371 if (other == disk_idx)
3373 if (!test_bit(R5_UPTODATE,
3374 &sh->dev[other].flags))
3378 pr_debug("Computing stripe %llu blocks %d,%d\n",
3379 (unsigned long long)sh->sector,
3381 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3382 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3383 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
3384 set_bit(R5_Wantcompute, &sh->dev[other].flags);
3385 sh->ops.target = disk_idx;
3386 sh->ops.target2 = other;
3390 } else if (test_bit(R5_Insync, &dev->flags)) {
3391 set_bit(R5_LOCKED, &dev->flags);
3392 set_bit(R5_Wantread, &dev->flags);
3394 pr_debug("Reading block %d (sync=%d)\n",
3395 disk_idx, s->syncing);
3403 * handle_stripe_fill - read or compute data to satisfy pending requests.
3405 static void handle_stripe_fill(struct stripe_head *sh,
3406 struct stripe_head_state *s,
3411 /* look for blocks to read/compute, skip this if a compute
3412 * is already in flight, or if the stripe contents are in the
3413 * midst of changing due to a write
3415 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
3416 !sh->reconstruct_state)
3417 for (i = disks; i--; )
3418 if (fetch_block(sh, s, i, disks))
3420 set_bit(STRIPE_HANDLE, &sh->state);
3423 /* handle_stripe_clean_event
3424 * any written block on an uptodate or failed drive can be returned.
3425 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
3426 * never LOCKED, so we don't need to test 'failed' directly.
3428 static void handle_stripe_clean_event(struct r5conf *conf,
3429 struct stripe_head *sh, int disks, struct bio **return_bi)
3433 int discard_pending = 0;
3434 struct stripe_head *head_sh = sh;
3435 bool do_endio = false;
3438 for (i = disks; i--; )
3439 if (sh->dev[i].written) {
3441 if (!test_bit(R5_LOCKED, &dev->flags) &&
3442 (test_bit(R5_UPTODATE, &dev->flags) ||
3443 test_bit(R5_Discard, &dev->flags) ||
3444 test_bit(R5_SkipCopy, &dev->flags))) {
3445 /* We can return any write requests */
3446 struct bio *wbi, *wbi2;
3447 pr_debug("Return write for disc %d\n", i);
3448 if (test_and_clear_bit(R5_Discard, &dev->flags))
3449 clear_bit(R5_UPTODATE, &dev->flags);
3450 if (test_and_clear_bit(R5_SkipCopy, &dev->flags)) {
3451 WARN_ON(test_bit(R5_UPTODATE, &dev->flags));
3456 dev->page = dev->orig_page;
3458 dev->written = NULL;
3459 while (wbi && wbi->bi_iter.bi_sector <
3460 dev->sector + STRIPE_SECTORS) {
3461 wbi2 = r5_next_bio(wbi, dev->sector);
3462 if (!raid5_dec_bi_active_stripes(wbi)) {
3463 md_write_end(conf->mddev);
3464 wbi->bi_next = *return_bi;
3469 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3471 !test_bit(STRIPE_DEGRADED, &sh->state),
3473 if (head_sh->batch_head) {
3474 sh = list_first_entry(&sh->batch_list,
3477 if (sh != head_sh) {
3484 } else if (test_bit(R5_Discard, &dev->flags))
3485 discard_pending = 1;
3486 WARN_ON(test_bit(R5_SkipCopy, &dev->flags));
3487 WARN_ON(dev->page != dev->orig_page);
3489 if (!discard_pending &&
3490 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
3491 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
3492 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3493 if (sh->qd_idx >= 0) {
3494 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
3495 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
3497 /* now that discard is done we can proceed with any sync */
3498 clear_bit(STRIPE_DISCARD, &sh->state);
3500 * SCSI discard will change some bio fields and the stripe has
3501 * no updated data, so remove it from hash list and the stripe
3502 * will be reinitialized
3504 spin_lock_irq(&conf->device_lock);
3507 if (head_sh->batch_head) {
3508 sh = list_first_entry(&sh->batch_list,
3509 struct stripe_head, batch_list);
3513 spin_unlock_irq(&conf->device_lock);
3516 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
3517 set_bit(STRIPE_HANDLE, &sh->state);
3521 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3522 if (atomic_dec_and_test(&conf->pending_full_writes))
3523 md_wakeup_thread(conf->mddev->thread);
3525 if (!head_sh->batch_head || !do_endio)
3527 for (i = 0; i < head_sh->disks; i++) {
3528 if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
3531 while (!list_empty(&head_sh->batch_list)) {
3533 sh = list_first_entry(&head_sh->batch_list,
3534 struct stripe_head, batch_list);
3535 list_del_init(&sh->batch_list);
3537 WARN_ON_ONCE(sh->state & ((1 << STRIPE_ACTIVE) |
3538 (1 << STRIPE_SYNCING) |
3539 (1 << STRIPE_REPLACED) |
3540 (1 << STRIPE_PREREAD_ACTIVE) |
3541 (1 << STRIPE_DELAYED) |
3542 (1 << STRIPE_BIT_DELAY) |
3543 (1 << STRIPE_FULL_WRITE) |
3544 (1 << STRIPE_BIOFILL_RUN) |
3545 (1 << STRIPE_COMPUTE_RUN) |
3546 (1 << STRIPE_OPS_REQ_PENDING) |
3547 (1 << STRIPE_DISCARD) |
3548 (1 << STRIPE_BATCH_READY) |
3549 (1 << STRIPE_BATCH_ERR) |
3550 (1 << STRIPE_BITMAP_PENDING)));
3551 WARN_ON_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) |
3552 (1 << STRIPE_REPLACED)));
3554 set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
3555 (1 << STRIPE_DEGRADED)),
3556 head_sh->state & (1 << STRIPE_INSYNC));
3558 sh->check_state = head_sh->check_state;
3559 sh->reconstruct_state = head_sh->reconstruct_state;
3560 for (i = 0; i < sh->disks; i++) {
3561 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3563 sh->dev[i].flags = head_sh->dev[i].flags;
3566 spin_lock_irq(&sh->stripe_lock);
3567 sh->batch_head = NULL;
3568 spin_unlock_irq(&sh->stripe_lock);
3569 if (sh->state & STRIPE_EXPAND_SYNC_FLAGS)
3570 set_bit(STRIPE_HANDLE, &sh->state);
3574 spin_lock_irq(&head_sh->stripe_lock);
3575 head_sh->batch_head = NULL;
3576 spin_unlock_irq(&head_sh->stripe_lock);
3578 wake_up(&conf->wait_for_overlap);
3579 if (head_sh->state & STRIPE_EXPAND_SYNC_FLAGS)
3580 set_bit(STRIPE_HANDLE, &head_sh->state);
3583 static void handle_stripe_dirtying(struct r5conf *conf,
3584 struct stripe_head *sh,
3585 struct stripe_head_state *s,
3588 int rmw = 0, rcw = 0, i;
3589 sector_t recovery_cp = conf->mddev->recovery_cp;
3591 /* Check whether resync is now happening or should start.
3592 * If yes, then the array is dirty (after unclean shutdown or
3593 * initial creation), so parity in some stripes might be inconsistent.
3594 * In this case, we need to always do reconstruct-write, to ensure
3595 * that in case of drive failure or read-error correction, we
3596 * generate correct data from the parity.
3598 if (conf->rmw_level == PARITY_DISABLE_RMW ||
3599 (recovery_cp < MaxSector && sh->sector >= recovery_cp &&
3601 /* Calculate the real rcw later - for now make it
3602 * look like rcw is cheaper
3605 pr_debug("force RCW rmw_level=%u, recovery_cp=%llu sh->sector=%llu\n",
3606 conf->rmw_level, (unsigned long long)recovery_cp,
3607 (unsigned long long)sh->sector);
3608 } else for (i = disks; i--; ) {
3609 /* would I have to read this buffer for read_modify_write */
3610 struct r5dev *dev = &sh->dev[i];
3611 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3612 !test_bit(R5_LOCKED, &dev->flags) &&
3613 !(test_bit(R5_UPTODATE, &dev->flags) ||
3614 test_bit(R5_Wantcompute, &dev->flags))) {
3615 if (test_bit(R5_Insync, &dev->flags))
3618 rmw += 2*disks; /* cannot read it */
3620 /* Would I have to read this buffer for reconstruct_write */
3621 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3622 i != sh->pd_idx && i != sh->qd_idx &&
3623 !test_bit(R5_LOCKED, &dev->flags) &&
3624 !(test_bit(R5_UPTODATE, &dev->flags) ||
3625 test_bit(R5_Wantcompute, &dev->flags))) {
3626 if (test_bit(R5_Insync, &dev->flags))
3632 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
3633 (unsigned long long)sh->sector, rmw, rcw);
3634 set_bit(STRIPE_HANDLE, &sh->state);
3635 if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_ENABLE_RMW)) && rmw > 0) {
3636 /* prefer read-modify-write, but need to get some data */
3637 if (conf->mddev->queue)
3638 blk_add_trace_msg(conf->mddev->queue,
3639 "raid5 rmw %llu %d",
3640 (unsigned long long)sh->sector, rmw);
3641 for (i = disks; i--; ) {
3642 struct r5dev *dev = &sh->dev[i];
3643 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3644 !test_bit(R5_LOCKED, &dev->flags) &&
3645 !(test_bit(R5_UPTODATE, &dev->flags) ||
3646 test_bit(R5_Wantcompute, &dev->flags)) &&
3647 test_bit(R5_Insync, &dev->flags)) {
3648 if (test_bit(STRIPE_PREREAD_ACTIVE,
3650 pr_debug("Read_old block %d for r-m-w\n",
3652 set_bit(R5_LOCKED, &dev->flags);
3653 set_bit(R5_Wantread, &dev->flags);
3656 set_bit(STRIPE_DELAYED, &sh->state);
3657 set_bit(STRIPE_HANDLE, &sh->state);
3662 if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_ENABLE_RMW)) && rcw > 0) {
3663 /* want reconstruct write, but need to get some data */
3666 for (i = disks; i--; ) {
3667 struct r5dev *dev = &sh->dev[i];
3668 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3669 i != sh->pd_idx && i != sh->qd_idx &&
3670 !test_bit(R5_LOCKED, &dev->flags) &&
3671 !(test_bit(R5_UPTODATE, &dev->flags) ||
3672 test_bit(R5_Wantcompute, &dev->flags))) {
3674 if (test_bit(R5_Insync, &dev->flags) &&
3675 test_bit(STRIPE_PREREAD_ACTIVE,
3677 pr_debug("Read_old block "
3678 "%d for Reconstruct\n", i);
3679 set_bit(R5_LOCKED, &dev->flags);
3680 set_bit(R5_Wantread, &dev->flags);
3684 set_bit(STRIPE_DELAYED, &sh->state);
3685 set_bit(STRIPE_HANDLE, &sh->state);
3689 if (rcw && conf->mddev->queue)
3690 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
3691 (unsigned long long)sh->sector,
3692 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
3695 if (rcw > disks && rmw > disks &&
3696 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3697 set_bit(STRIPE_DELAYED, &sh->state);
3699 /* now if nothing is locked, and if we have enough data,
3700 * we can start a write request
3702 /* since handle_stripe can be called at any time we need to handle the
3703 * case where a compute block operation has been submitted and then a
3704 * subsequent call wants to start a write request. raid_run_ops only
3705 * handles the case where compute block and reconstruct are requested
3706 * simultaneously. If this is not the case then new writes need to be
3707 * held off until the compute completes.
3709 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
3710 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
3711 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
3712 schedule_reconstruction(sh, s, rcw == 0, 0);
3715 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
3716 struct stripe_head_state *s, int disks)
3718 struct r5dev *dev = NULL;
3720 BUG_ON(sh->batch_head);
3721 set_bit(STRIPE_HANDLE, &sh->state);
3723 switch (sh->check_state) {
3724 case check_state_idle:
3725 /* start a new check operation if there are no failures */
3726 if (s->failed == 0) {
3727 BUG_ON(s->uptodate != disks);
3728 sh->check_state = check_state_run;
3729 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3730 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3734 dev = &sh->dev[s->failed_num[0]];
3736 case check_state_compute_result:
3737 sh->check_state = check_state_idle;
3739 dev = &sh->dev[sh->pd_idx];
3741 /* check that a write has not made the stripe insync */
3742 if (test_bit(STRIPE_INSYNC, &sh->state))
3745 /* either failed parity check, or recovery is happening */
3746 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3747 BUG_ON(s->uptodate != disks);
3749 set_bit(R5_LOCKED, &dev->flags);
3751 set_bit(R5_Wantwrite, &dev->flags);
3753 clear_bit(STRIPE_DEGRADED, &sh->state);
3754 set_bit(STRIPE_INSYNC, &sh->state);
3756 case check_state_run:
3757 break; /* we will be called again upon completion */
3758 case check_state_check_result:
3759 sh->check_state = check_state_idle;
3761 /* if a failure occurred during the check operation, leave
3762 * STRIPE_INSYNC not set and let the stripe be handled again
3767 /* handle a successful check operation, if parity is correct
3768 * we are done. Otherwise update the mismatch count and repair
3769 * parity if !MD_RECOVERY_CHECK
3771 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
3772 /* parity is correct (on disc,
3773 * not in buffer any more)
3775 set_bit(STRIPE_INSYNC, &sh->state);
3777 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3778 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3779 /* don't try to repair!! */
3780 set_bit(STRIPE_INSYNC, &sh->state);
3782 sh->check_state = check_state_compute_run;
3783 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3784 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3785 set_bit(R5_Wantcompute,
3786 &sh->dev[sh->pd_idx].flags);
3787 sh->ops.target = sh->pd_idx;
3788 sh->ops.target2 = -1;
3793 case check_state_compute_run:
3796 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3797 __func__, sh->check_state,
3798 (unsigned long long) sh->sector);
3803 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
3804 struct stripe_head_state *s,
3807 int pd_idx = sh->pd_idx;
3808 int qd_idx = sh->qd_idx;
3811 BUG_ON(sh->batch_head);
3812 set_bit(STRIPE_HANDLE, &sh->state);
3814 BUG_ON(s->failed > 2);
3816 /* Want to check and possibly repair P and Q.
3817 * However there could be one 'failed' device, in which
3818 * case we can only check one of them, possibly using the
3819 * other to generate missing data
3822 switch (sh->check_state) {
3823 case check_state_idle:
3824 /* start a new check operation if there are < 2 failures */
3825 if (s->failed == s->q_failed) {
3826 /* The only possible failed device holds Q, so it
3827 * makes sense to check P (If anything else were failed,
3828 * we would have used P to recreate it).
3830 sh->check_state = check_state_run;
3832 if (!s->q_failed && s->failed < 2) {
3833 /* Q is not failed, and we didn't use it to generate
3834 * anything, so it makes sense to check it
3836 if (sh->check_state == check_state_run)
3837 sh->check_state = check_state_run_pq;
3839 sh->check_state = check_state_run_q;
3842 /* discard potentially stale zero_sum_result */
3843 sh->ops.zero_sum_result = 0;
3845 if (sh->check_state == check_state_run) {
3846 /* async_xor_zero_sum destroys the contents of P */
3847 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3850 if (sh->check_state >= check_state_run &&
3851 sh->check_state <= check_state_run_pq) {
3852 /* async_syndrome_zero_sum preserves P and Q, so
3853 * no need to mark them !uptodate here
3855 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3859 /* we have 2-disk failure */
3860 BUG_ON(s->failed != 2);
3862 case check_state_compute_result:
3863 sh->check_state = check_state_idle;
3865 /* check that a write has not made the stripe insync */
3866 if (test_bit(STRIPE_INSYNC, &sh->state))
3869 /* now write out any block on a failed drive,
3870 * or P or Q if they were recomputed
3872 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
3873 if (s->failed == 2) {
3874 dev = &sh->dev[s->failed_num[1]];
3876 set_bit(R5_LOCKED, &dev->flags);
3877 set_bit(R5_Wantwrite, &dev->flags);
3879 if (s->failed >= 1) {
3880 dev = &sh->dev[s->failed_num[0]];
3882 set_bit(R5_LOCKED, &dev->flags);
3883 set_bit(R5_Wantwrite, &dev->flags);
3885 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3886 dev = &sh->dev[pd_idx];
3888 set_bit(R5_LOCKED, &dev->flags);
3889 set_bit(R5_Wantwrite, &dev->flags);
3891 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3892 dev = &sh->dev[qd_idx];
3894 set_bit(R5_LOCKED, &dev->flags);
3895 set_bit(R5_Wantwrite, &dev->flags);
3897 clear_bit(STRIPE_DEGRADED, &sh->state);
3899 set_bit(STRIPE_INSYNC, &sh->state);
3901 case check_state_run:
3902 case check_state_run_q:
3903 case check_state_run_pq:
3904 break; /* we will be called again upon completion */
3905 case check_state_check_result:
3906 sh->check_state = check_state_idle;
3908 /* handle a successful check operation, if parity is correct
3909 * we are done. Otherwise update the mismatch count and repair
3910 * parity if !MD_RECOVERY_CHECK
3912 if (sh->ops.zero_sum_result == 0) {
3913 /* both parities are correct */
3915 set_bit(STRIPE_INSYNC, &sh->state);
3917 /* in contrast to the raid5 case we can validate
3918 * parity, but still have a failure to write
3921 sh->check_state = check_state_compute_result;
3922 /* Returning at this point means that we may go
3923 * off and bring p and/or q uptodate again so
3924 * we make sure to check zero_sum_result again
3925 * to verify if p or q need writeback
3929 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3930 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3931 /* don't try to repair!! */
3932 set_bit(STRIPE_INSYNC, &sh->state);
3934 int *target = &sh->ops.target;
3936 sh->ops.target = -1;
3937 sh->ops.target2 = -1;
3938 sh->check_state = check_state_compute_run;
3939 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3940 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3941 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3942 set_bit(R5_Wantcompute,
3943 &sh->dev[pd_idx].flags);
3945 target = &sh->ops.target2;
3948 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3949 set_bit(R5_Wantcompute,
3950 &sh->dev[qd_idx].flags);
3957 case check_state_compute_run:
3960 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3961 __func__, sh->check_state,
3962 (unsigned long long) sh->sector);
3967 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
3971 /* We have read all the blocks in this stripe and now we need to
3972 * copy some of them into a target stripe for expand.
3974 struct dma_async_tx_descriptor *tx = NULL;
3975 BUG_ON(sh->batch_head);
3976 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3977 for (i = 0; i < sh->disks; i++)
3978 if (i != sh->pd_idx && i != sh->qd_idx) {
3980 struct stripe_head *sh2;
3981 struct async_submit_ctl submit;
3983 sector_t bn = compute_blocknr(sh, i, 1);
3984 sector_t s = raid5_compute_sector(conf, bn, 0,
3986 sh2 = get_active_stripe(conf, s, 0, 1, 1);
3988 /* so far only the early blocks of this stripe
3989 * have been requested. When later blocks
3990 * get requested, we will try again
3993 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3994 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3995 /* must have already done this block */
3996 release_stripe(sh2);
4000 /* place all the copies on one channel */
4001 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
4002 tx = async_memcpy(sh2->dev[dd_idx].page,
4003 sh->dev[i].page, 0, 0, STRIPE_SIZE,
4006 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
4007 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
4008 for (j = 0; j < conf->raid_disks; j++)
4009 if (j != sh2->pd_idx &&
4011 !test_bit(R5_Expanded, &sh2->dev[j].flags))
4013 if (j == conf->raid_disks) {
4014 set_bit(STRIPE_EXPAND_READY, &sh2->state);
4015 set_bit(STRIPE_HANDLE, &sh2->state);
4017 release_stripe(sh2);
4020 /* done submitting copies, wait for them to complete */
4021 async_tx_quiesce(&tx);
4025 * handle_stripe - do things to a stripe.
4027 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
4028 * state of various bits to see what needs to be done.
4030 * return some read requests which now have data
4031 * return some write requests which are safely on storage
4032 * schedule a read on some buffers
4033 * schedule a write of some buffers
4034 * return confirmation of parity correctness
4038 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
4040 struct r5conf *conf = sh->raid_conf;
4041 int disks = sh->disks;
4044 int do_recovery = 0;
4046 memset(s, 0, sizeof(*s));
4048 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state) && !sh->batch_head;
4049 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state) && !sh->batch_head;
4050 s->failed_num[0] = -1;
4051 s->failed_num[1] = -1;
4053 /* Now to look around and see what can be done */
4055 for (i=disks; i--; ) {
4056 struct md_rdev *rdev;
4063 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
4065 dev->toread, dev->towrite, dev->written);
4066 /* maybe we can reply to a read
4068 * new wantfill requests are only permitted while
4069 * ops_complete_biofill is guaranteed to be inactive
4071 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
4072 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
4073 set_bit(R5_Wantfill, &dev->flags);
4075 /* now count some things */
4076 if (test_bit(R5_LOCKED, &dev->flags))
4078 if (test_bit(R5_UPTODATE, &dev->flags))
4080 if (test_bit(R5_Wantcompute, &dev->flags)) {
4082 BUG_ON(s->compute > 2);
4085 if (test_bit(R5_Wantfill, &dev->flags))
4087 else if (dev->toread)
4091 if (!test_bit(R5_OVERWRITE, &dev->flags))
4096 /* Prefer to use the replacement for reads, but only
4097 * if it is recovered enough and has no bad blocks.
4099 rdev = rcu_dereference(conf->disks[i].replacement);
4100 if (rdev && !test_bit(Faulty, &rdev->flags) &&
4101 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
4102 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4103 &first_bad, &bad_sectors))
4104 set_bit(R5_ReadRepl, &dev->flags);
4107 set_bit(R5_NeedReplace, &dev->flags);
4108 rdev = rcu_dereference(conf->disks[i].rdev);
4109 clear_bit(R5_ReadRepl, &dev->flags);
4111 if (rdev && test_bit(Faulty, &rdev->flags))
4114 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4115 &first_bad, &bad_sectors);
4116 if (s->blocked_rdev == NULL
4117 && (test_bit(Blocked, &rdev->flags)
4120 set_bit(BlockedBadBlocks,
4122 s->blocked_rdev = rdev;
4123 atomic_inc(&rdev->nr_pending);
4126 clear_bit(R5_Insync, &dev->flags);
4130 /* also not in-sync */
4131 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
4132 test_bit(R5_UPTODATE, &dev->flags)) {
4133 /* treat as in-sync, but with a read error
4134 * which we can now try to correct
4136 set_bit(R5_Insync, &dev->flags);
4137 set_bit(R5_ReadError, &dev->flags);
4139 } else if (test_bit(In_sync, &rdev->flags))
4140 set_bit(R5_Insync, &dev->flags);
4141 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
4142 /* in sync if before recovery_offset */
4143 set_bit(R5_Insync, &dev->flags);
4144 else if (test_bit(R5_UPTODATE, &dev->flags) &&
4145 test_bit(R5_Expanded, &dev->flags))
4146 /* If we've reshaped into here, we assume it is Insync.
4147 * We will shortly update recovery_offset to make
4150 set_bit(R5_Insync, &dev->flags);
4152 if (test_bit(R5_WriteError, &dev->flags)) {
4153 /* This flag does not apply to '.replacement'
4154 * only to .rdev, so make sure to check that*/
4155 struct md_rdev *rdev2 = rcu_dereference(
4156 conf->disks[i].rdev);
4158 clear_bit(R5_Insync, &dev->flags);
4159 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4160 s->handle_bad_blocks = 1;
4161 atomic_inc(&rdev2->nr_pending);
4163 clear_bit(R5_WriteError, &dev->flags);
4165 if (test_bit(R5_MadeGood, &dev->flags)) {
4166 /* This flag does not apply to '.replacement'
4167 * only to .rdev, so make sure to check that*/
4168 struct md_rdev *rdev2 = rcu_dereference(
4169 conf->disks[i].rdev);
4170 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4171 s->handle_bad_blocks = 1;
4172 atomic_inc(&rdev2->nr_pending);
4174 clear_bit(R5_MadeGood, &dev->flags);
4176 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
4177 struct md_rdev *rdev2 = rcu_dereference(
4178 conf->disks[i].replacement);
4179 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4180 s->handle_bad_blocks = 1;
4181 atomic_inc(&rdev2->nr_pending);
4183 clear_bit(R5_MadeGoodRepl, &dev->flags);
4185 if (!test_bit(R5_Insync, &dev->flags)) {
4186 /* The ReadError flag will just be confusing now */
4187 clear_bit(R5_ReadError, &dev->flags);
4188 clear_bit(R5_ReWrite, &dev->flags);
4190 if (test_bit(R5_ReadError, &dev->flags))
4191 clear_bit(R5_Insync, &dev->flags);
4192 if (!test_bit(R5_Insync, &dev->flags)) {
4194 s->failed_num[s->failed] = i;
4196 if (rdev && !test_bit(Faulty, &rdev->flags))
4200 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4201 /* If there is a failed device being replaced,
4202 * we must be recovering.
4203 * else if we are after recovery_cp, we must be syncing
4204 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
4205 * else we can only be replacing
4206 * sync and recovery both need to read all devices, and so
4207 * use the same flag.
4210 sh->sector >= conf->mddev->recovery_cp ||
4211 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
4219 static int clear_batch_ready(struct stripe_head *sh)
4221 /* Return '1' if this is a member of batch, or
4222 * '0' if it is a lone stripe or a head which can now be
4225 struct stripe_head *tmp;
4226 if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state))
4227 return (sh->batch_head && sh->batch_head != sh);
4228 spin_lock(&sh->stripe_lock);
4229 if (!sh->batch_head) {
4230 spin_unlock(&sh->stripe_lock);
4235 * this stripe could be added to a batch list before we check
4236 * BATCH_READY, skips it
4238 if (sh->batch_head != sh) {
4239 spin_unlock(&sh->stripe_lock);
4242 spin_lock(&sh->batch_lock);
4243 list_for_each_entry(tmp, &sh->batch_list, batch_list)
4244 clear_bit(STRIPE_BATCH_READY, &tmp->state);
4245 spin_unlock(&sh->batch_lock);
4246 spin_unlock(&sh->stripe_lock);
4249 * BATCH_READY is cleared, no new stripes can be added.
4250 * batch_list can be accessed without lock
4255 static void break_stripe_batch_list(struct stripe_head *head_sh,
4256 unsigned long handle_flags)
4258 struct stripe_head *sh, *next;
4262 list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) {
4264 list_del_init(&sh->batch_list);
4266 WARN_ON_ONCE(sh->state & ((1 << STRIPE_ACTIVE) |
4267 (1 << STRIPE_SYNCING) |
4268 (1 << STRIPE_REPLACED) |
4269 (1 << STRIPE_PREREAD_ACTIVE) |
4270 (1 << STRIPE_DELAYED) |
4271 (1 << STRIPE_BIT_DELAY) |
4272 (1 << STRIPE_FULL_WRITE) |
4273 (1 << STRIPE_BIOFILL_RUN) |
4274 (1 << STRIPE_COMPUTE_RUN) |
4275 (1 << STRIPE_OPS_REQ_PENDING) |
4276 (1 << STRIPE_DISCARD) |
4277 (1 << STRIPE_BATCH_READY) |
4278 (1 << STRIPE_BATCH_ERR) |
4279 (1 << STRIPE_BITMAP_PENDING)));
4280 WARN_ON_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) |
4281 (1 << STRIPE_REPLACED)));
4283 set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
4284 (1 << STRIPE_DEGRADED)),
4285 head_sh->state & (1 << STRIPE_INSYNC));
4287 sh->check_state = head_sh->check_state;
4288 sh->reconstruct_state = head_sh->reconstruct_state;
4289 for (i = 0; i < sh->disks; i++) {
4290 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
4292 sh->dev[i].flags = head_sh->dev[i].flags &
4293 (~((1 << R5_WriteError) | (1 << R5_Overlap)));
4295 spin_lock_irq(&sh->stripe_lock);
4296 sh->batch_head = NULL;
4297 spin_unlock_irq(&sh->stripe_lock);
4298 if (handle_flags == 0 ||
4299 sh->state & handle_flags)
4300 set_bit(STRIPE_HANDLE, &sh->state);
4303 spin_lock_irq(&head_sh->stripe_lock);
4304 head_sh->batch_head = NULL;
4305 spin_unlock_irq(&head_sh->stripe_lock);
4306 for (i = 0; i < head_sh->disks; i++)
4307 if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
4309 if (head_sh->state & handle_flags)
4310 set_bit(STRIPE_HANDLE, &head_sh->state);
4313 wake_up(&head_sh->raid_conf->wait_for_overlap);
4316 static void handle_stripe(struct stripe_head *sh)
4318 struct stripe_head_state s;
4319 struct r5conf *conf = sh->raid_conf;
4322 int disks = sh->disks;
4323 struct r5dev *pdev, *qdev;
4325 clear_bit(STRIPE_HANDLE, &sh->state);
4326 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
4327 /* already being handled, ensure it gets handled
4328 * again when current action finishes */
4329 set_bit(STRIPE_HANDLE, &sh->state);
4333 if (clear_batch_ready(sh) ) {
4334 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4338 if (test_and_clear_bit(STRIPE_BATCH_ERR, &sh->state))
4339 break_stripe_batch_list(sh, 0);
4341 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) {
4342 spin_lock(&sh->stripe_lock);
4343 /* Cannot process 'sync' concurrently with 'discard' */
4344 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
4345 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
4346 set_bit(STRIPE_SYNCING, &sh->state);
4347 clear_bit(STRIPE_INSYNC, &sh->state);
4348 clear_bit(STRIPE_REPLACED, &sh->state);
4350 spin_unlock(&sh->stripe_lock);
4352 clear_bit(STRIPE_DELAYED, &sh->state);
4354 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
4355 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
4356 (unsigned long long)sh->sector, sh->state,
4357 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
4358 sh->check_state, sh->reconstruct_state);
4360 analyse_stripe(sh, &s);
4362 if (s.handle_bad_blocks) {
4363 set_bit(STRIPE_HANDLE, &sh->state);
4367 if (unlikely(s.blocked_rdev)) {
4368 if (s.syncing || s.expanding || s.expanded ||
4369 s.replacing || s.to_write || s.written) {
4370 set_bit(STRIPE_HANDLE, &sh->state);
4373 /* There is nothing for the blocked_rdev to block */
4374 rdev_dec_pending(s.blocked_rdev, conf->mddev);
4375 s.blocked_rdev = NULL;
4378 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
4379 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
4380 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
4383 pr_debug("locked=%d uptodate=%d to_read=%d"
4384 " to_write=%d failed=%d failed_num=%d,%d\n",
4385 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
4386 s.failed_num[0], s.failed_num[1]);
4387 /* check if the array has lost more than max_degraded devices and,
4388 * if so, some requests might need to be failed.
4390 if (s.failed > conf->max_degraded) {
4391 sh->check_state = 0;
4392 sh->reconstruct_state = 0;
4393 if (s.to_read+s.to_write+s.written)
4394 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
4395 if (s.syncing + s.replacing)
4396 handle_failed_sync(conf, sh, &s);
4399 /* Now we check to see if any write operations have recently
4403 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
4405 if (sh->reconstruct_state == reconstruct_state_drain_result ||
4406 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
4407 sh->reconstruct_state = reconstruct_state_idle;
4409 /* All the 'written' buffers and the parity block are ready to
4410 * be written back to disk
4412 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
4413 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
4414 BUG_ON(sh->qd_idx >= 0 &&
4415 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
4416 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
4417 for (i = disks; i--; ) {
4418 struct r5dev *dev = &sh->dev[i];
4419 if (test_bit(R5_LOCKED, &dev->flags) &&
4420 (i == sh->pd_idx || i == sh->qd_idx ||
4422 pr_debug("Writing block %d\n", i);
4423 set_bit(R5_Wantwrite, &dev->flags);
4428 if (!test_bit(R5_Insync, &dev->flags) ||
4429 ((i == sh->pd_idx || i == sh->qd_idx) &&
4431 set_bit(STRIPE_INSYNC, &sh->state);
4434 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4435 s.dec_preread_active = 1;
4439 * might be able to return some write requests if the parity blocks
4440 * are safe, or on a failed drive
4442 pdev = &sh->dev[sh->pd_idx];
4443 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
4444 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
4445 qdev = &sh->dev[sh->qd_idx];
4446 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
4447 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
4451 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
4452 && !test_bit(R5_LOCKED, &pdev->flags)
4453 && (test_bit(R5_UPTODATE, &pdev->flags) ||
4454 test_bit(R5_Discard, &pdev->flags))))) &&
4455 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
4456 && !test_bit(R5_LOCKED, &qdev->flags)
4457 && (test_bit(R5_UPTODATE, &qdev->flags) ||
4458 test_bit(R5_Discard, &qdev->flags))))))
4459 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
4461 /* Now we might consider reading some blocks, either to check/generate
4462 * parity, or to satisfy requests
4463 * or to load a block that is being partially written.
4465 if (s.to_read || s.non_overwrite
4466 || (conf->level == 6 && s.to_write && s.failed)
4467 || (s.syncing && (s.uptodate + s.compute < disks))
4470 handle_stripe_fill(sh, &s, disks);
4472 /* Now to consider new write requests and what else, if anything
4473 * should be read. We do not handle new writes when:
4474 * 1/ A 'write' operation (copy+xor) is already in flight.
4475 * 2/ A 'check' operation is in flight, as it may clobber the parity
4478 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
4479 handle_stripe_dirtying(conf, sh, &s, disks);
4481 /* maybe we need to check and possibly fix the parity for this stripe
4482 * Any reads will already have been scheduled, so we just see if enough
4483 * data is available. The parity check is held off while parity
4484 * dependent operations are in flight.
4486 if (sh->check_state ||
4487 (s.syncing && s.locked == 0 &&
4488 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4489 !test_bit(STRIPE_INSYNC, &sh->state))) {
4490 if (conf->level == 6)
4491 handle_parity_checks6(conf, sh, &s, disks);
4493 handle_parity_checks5(conf, sh, &s, disks);
4496 if ((s.replacing || s.syncing) && s.locked == 0
4497 && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
4498 && !test_bit(STRIPE_REPLACED, &sh->state)) {
4499 /* Write out to replacement devices where possible */
4500 for (i = 0; i < conf->raid_disks; i++)
4501 if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
4502 WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
4503 set_bit(R5_WantReplace, &sh->dev[i].flags);
4504 set_bit(R5_LOCKED, &sh->dev[i].flags);
4508 set_bit(STRIPE_INSYNC, &sh->state);
4509 set_bit(STRIPE_REPLACED, &sh->state);
4511 if ((s.syncing || s.replacing) && s.locked == 0 &&
4512 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4513 test_bit(STRIPE_INSYNC, &sh->state)) {
4514 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4515 clear_bit(STRIPE_SYNCING, &sh->state);
4516 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
4517 wake_up(&conf->wait_for_overlap);
4520 /* If the failed drives are just a ReadError, then we might need
4521 * to progress the repair/check process
4523 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
4524 for (i = 0; i < s.failed; i++) {
4525 struct r5dev *dev = &sh->dev[s.failed_num[i]];
4526 if (test_bit(R5_ReadError, &dev->flags)
4527 && !test_bit(R5_LOCKED, &dev->flags)
4528 && test_bit(R5_UPTODATE, &dev->flags)
4530 if (!test_bit(R5_ReWrite, &dev->flags)) {
4531 set_bit(R5_Wantwrite, &dev->flags);
4532 set_bit(R5_ReWrite, &dev->flags);
4533 set_bit(R5_LOCKED, &dev->flags);
4536 /* let's read it back */
4537 set_bit(R5_Wantread, &dev->flags);
4538 set_bit(R5_LOCKED, &dev->flags);
4544 /* Finish reconstruct operations initiated by the expansion process */
4545 if (sh->reconstruct_state == reconstruct_state_result) {
4546 struct stripe_head *sh_src
4547 = get_active_stripe(conf, sh->sector, 1, 1, 1);
4548 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
4549 /* sh cannot be written until sh_src has been read.
4550 * so arrange for sh to be delayed a little
4552 set_bit(STRIPE_DELAYED, &sh->state);
4553 set_bit(STRIPE_HANDLE, &sh->state);
4554 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
4556 atomic_inc(&conf->preread_active_stripes);
4557 release_stripe(sh_src);
4561 release_stripe(sh_src);
4563 sh->reconstruct_state = reconstruct_state_idle;
4564 clear_bit(STRIPE_EXPANDING, &sh->state);
4565 for (i = conf->raid_disks; i--; ) {
4566 set_bit(R5_Wantwrite, &sh->dev[i].flags);
4567 set_bit(R5_LOCKED, &sh->dev[i].flags);
4572 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
4573 !sh->reconstruct_state) {
4574 /* Need to write out all blocks after computing parity */
4575 sh->disks = conf->raid_disks;
4576 stripe_set_idx(sh->sector, conf, 0, sh);
4577 schedule_reconstruction(sh, &s, 1, 1);
4578 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
4579 clear_bit(STRIPE_EXPAND_READY, &sh->state);
4580 atomic_dec(&conf->reshape_stripes);
4581 wake_up(&conf->wait_for_overlap);
4582 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4585 if (s.expanding && s.locked == 0 &&
4586 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
4587 handle_stripe_expansion(conf, sh);
4590 /* wait for this device to become unblocked */
4591 if (unlikely(s.blocked_rdev)) {
4592 if (conf->mddev->external)
4593 md_wait_for_blocked_rdev(s.blocked_rdev,
4596 /* Internal metadata will immediately
4597 * be written by raid5d, so we don't
4598 * need to wait here.
4600 rdev_dec_pending(s.blocked_rdev,
4604 if (s.handle_bad_blocks)
4605 for (i = disks; i--; ) {
4606 struct md_rdev *rdev;
4607 struct r5dev *dev = &sh->dev[i];
4608 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
4609 /* We own a safe reference to the rdev */
4610 rdev = conf->disks[i].rdev;
4611 if (!rdev_set_badblocks(rdev, sh->sector,
4613 md_error(conf->mddev, rdev);
4614 rdev_dec_pending(rdev, conf->mddev);
4616 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
4617 rdev = conf->disks[i].rdev;
4618 rdev_clear_badblocks(rdev, sh->sector,
4620 rdev_dec_pending(rdev, conf->mddev);
4622 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
4623 rdev = conf->disks[i].replacement;
4625 /* rdev have been moved down */
4626 rdev = conf->disks[i].rdev;
4627 rdev_clear_badblocks(rdev, sh->sector,
4629 rdev_dec_pending(rdev, conf->mddev);
4634 raid_run_ops(sh, s.ops_request);
4638 if (s.dec_preread_active) {
4639 /* We delay this until after ops_run_io so that if make_request
4640 * is waiting on a flush, it won't continue until the writes
4641 * have actually been submitted.
4643 atomic_dec(&conf->preread_active_stripes);
4644 if (atomic_read(&conf->preread_active_stripes) <
4646 md_wakeup_thread(conf->mddev->thread);
4649 return_io(s.return_bi);
4651 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4654 static void raid5_activate_delayed(struct r5conf *conf)
4656 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
4657 while (!list_empty(&conf->delayed_list)) {
4658 struct list_head *l = conf->delayed_list.next;
4659 struct stripe_head *sh;
4660 sh = list_entry(l, struct stripe_head, lru);
4662 clear_bit(STRIPE_DELAYED, &sh->state);
4663 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4664 atomic_inc(&conf->preread_active_stripes);
4665 list_add_tail(&sh->lru, &conf->hold_list);
4666 raid5_wakeup_stripe_thread(sh);
4671 static void activate_bit_delay(struct r5conf *conf,
4672 struct list_head *temp_inactive_list)
4674 /* device_lock is held */
4675 struct list_head head;
4676 list_add(&head, &conf->bitmap_list);
4677 list_del_init(&conf->bitmap_list);
4678 while (!list_empty(&head)) {
4679 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
4681 list_del_init(&sh->lru);
4682 atomic_inc(&sh->count);
4683 hash = sh->hash_lock_index;
4684 __release_stripe(conf, sh, &temp_inactive_list[hash]);
4688 static int raid5_congested(struct mddev *mddev, int bits)
4690 struct r5conf *conf = mddev->private;
4692 /* No difference between reads and writes. Just check
4693 * how busy the stripe_cache is
4696 if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
4700 if (atomic_read(&conf->empty_inactive_list_nr))
4706 /* We want read requests to align with chunks where possible,
4707 * but write requests don't need to.
4709 static int raid5_mergeable_bvec(struct mddev *mddev,
4710 struct bvec_merge_data *bvm,
4711 struct bio_vec *biovec)
4713 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
4715 unsigned int chunk_sectors = mddev->chunk_sectors;
4716 unsigned int bio_sectors = bvm->bi_size >> 9;
4719 * always allow writes to be mergeable, read as well if array
4720 * is degraded as we'll go through stripe cache anyway.
4722 if ((bvm->bi_rw & 1) == WRITE || mddev->degraded)
4723 return biovec->bv_len;
4725 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
4726 chunk_sectors = mddev->new_chunk_sectors;
4727 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
4728 if (max < 0) max = 0;
4729 if (max <= biovec->bv_len && bio_sectors == 0)
4730 return biovec->bv_len;
4735 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
4737 sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev);
4738 unsigned int chunk_sectors = mddev->chunk_sectors;
4739 unsigned int bio_sectors = bio_sectors(bio);
4741 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
4742 chunk_sectors = mddev->new_chunk_sectors;
4743 return chunk_sectors >=
4744 ((sector & (chunk_sectors - 1)) + bio_sectors);
4748 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
4749 * later sampled by raid5d.
4751 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
4753 unsigned long flags;
4755 spin_lock_irqsave(&conf->device_lock, flags);
4757 bi->bi_next = conf->retry_read_aligned_list;
4758 conf->retry_read_aligned_list = bi;
4760 spin_unlock_irqrestore(&conf->device_lock, flags);
4761 md_wakeup_thread(conf->mddev->thread);
4764 static struct bio *remove_bio_from_retry(struct r5conf *conf)
4768 bi = conf->retry_read_aligned;
4770 conf->retry_read_aligned = NULL;
4773 bi = conf->retry_read_aligned_list;
4775 conf->retry_read_aligned_list = bi->bi_next;
4778 * this sets the active strip count to 1 and the processed
4779 * strip count to zero (upper 8 bits)
4781 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
4788 * The "raid5_align_endio" should check if the read succeeded and if it
4789 * did, call bio_endio on the original bio (having bio_put the new bio
4791 * If the read failed..
4793 static void raid5_align_endio(struct bio *bi, int error)
4795 struct bio* raid_bi = bi->bi_private;
4796 struct mddev *mddev;
4797 struct r5conf *conf;
4798 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
4799 struct md_rdev *rdev;
4803 rdev = (void*)raid_bi->bi_next;
4804 raid_bi->bi_next = NULL;
4805 mddev = rdev->mddev;
4806 conf = mddev->private;
4808 rdev_dec_pending(rdev, conf->mddev);
4810 if (!error && uptodate) {
4811 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
4813 bio_endio(raid_bi, 0);
4814 if (atomic_dec_and_test(&conf->active_aligned_reads))
4815 wake_up(&conf->wait_for_stripe);
4819 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
4821 add_bio_to_retry(raid_bi, conf);
4824 static int bio_fits_rdev(struct bio *bi)
4826 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
4828 if (bio_sectors(bi) > queue_max_sectors(q))
4830 blk_recount_segments(q, bi);
4831 if (bi->bi_phys_segments > queue_max_segments(q))
4834 if (q->merge_bvec_fn)
4835 /* it's too hard to apply the merge_bvec_fn at this stage,
4843 static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio)
4845 struct r5conf *conf = mddev->private;
4847 struct bio* align_bi;
4848 struct md_rdev *rdev;
4849 sector_t end_sector;
4851 if (!in_chunk_boundary(mddev, raid_bio)) {
4852 pr_debug("chunk_aligned_read : non aligned\n");
4856 * use bio_clone_mddev to make a copy of the bio
4858 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
4862 * set bi_end_io to a new function, and set bi_private to the
4865 align_bi->bi_end_io = raid5_align_endio;
4866 align_bi->bi_private = raid_bio;
4870 align_bi->bi_iter.bi_sector =
4871 raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector,
4874 end_sector = bio_end_sector(align_bi);
4876 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
4877 if (!rdev || test_bit(Faulty, &rdev->flags) ||
4878 rdev->recovery_offset < end_sector) {
4879 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
4881 (test_bit(Faulty, &rdev->flags) ||
4882 !(test_bit(In_sync, &rdev->flags) ||
4883 rdev->recovery_offset >= end_sector)))
4890 atomic_inc(&rdev->nr_pending);
4892 raid_bio->bi_next = (void*)rdev;
4893 align_bi->bi_bdev = rdev->bdev;
4894 __clear_bit(BIO_SEG_VALID, &align_bi->bi_flags);
4896 if (!bio_fits_rdev(align_bi) ||
4897 is_badblock(rdev, align_bi->bi_iter.bi_sector,
4898 bio_sectors(align_bi),
4899 &first_bad, &bad_sectors)) {
4900 /* too big in some way, or has a known bad block */
4902 rdev_dec_pending(rdev, mddev);
4906 /* No reshape active, so we can trust rdev->data_offset */
4907 align_bi->bi_iter.bi_sector += rdev->data_offset;
4909 spin_lock_irq(&conf->device_lock);
4910 wait_event_lock_irq(conf->wait_for_stripe,
4913 atomic_inc(&conf->active_aligned_reads);
4914 spin_unlock_irq(&conf->device_lock);
4917 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4918 align_bi, disk_devt(mddev->gendisk),
4919 raid_bio->bi_iter.bi_sector);
4920 generic_make_request(align_bi);
4929 /* __get_priority_stripe - get the next stripe to process
4931 * Full stripe writes are allowed to pass preread active stripes up until
4932 * the bypass_threshold is exceeded. In general the bypass_count
4933 * increments when the handle_list is handled before the hold_list; however, it
4934 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4935 * stripe with in flight i/o. The bypass_count will be reset when the
4936 * head of the hold_list has changed, i.e. the head was promoted to the
4939 static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
4941 struct stripe_head *sh = NULL, *tmp;
4942 struct list_head *handle_list = NULL;
4943 struct r5worker_group *wg = NULL;
4945 if (conf->worker_cnt_per_group == 0) {
4946 handle_list = &conf->handle_list;
4947 } else if (group != ANY_GROUP) {
4948 handle_list = &conf->worker_groups[group].handle_list;
4949 wg = &conf->worker_groups[group];
4952 for (i = 0; i < conf->group_cnt; i++) {
4953 handle_list = &conf->worker_groups[i].handle_list;
4954 wg = &conf->worker_groups[i];
4955 if (!list_empty(handle_list))
4960 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4962 list_empty(handle_list) ? "empty" : "busy",
4963 list_empty(&conf->hold_list) ? "empty" : "busy",
4964 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4966 if (!list_empty(handle_list)) {
4967 sh = list_entry(handle_list->next, typeof(*sh), lru);
4969 if (list_empty(&conf->hold_list))
4970 conf->bypass_count = 0;
4971 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4972 if (conf->hold_list.next == conf->last_hold)
4973 conf->bypass_count++;
4975 conf->last_hold = conf->hold_list.next;
4976 conf->bypass_count -= conf->bypass_threshold;
4977 if (conf->bypass_count < 0)
4978 conf->bypass_count = 0;
4981 } else if (!list_empty(&conf->hold_list) &&
4982 ((conf->bypass_threshold &&
4983 conf->bypass_count > conf->bypass_threshold) ||
4984 atomic_read(&conf->pending_full_writes) == 0)) {
4986 list_for_each_entry(tmp, &conf->hold_list, lru) {
4987 if (conf->worker_cnt_per_group == 0 ||
4988 group == ANY_GROUP ||
4989 !cpu_online(tmp->cpu) ||
4990 cpu_to_group(tmp->cpu) == group) {
4997 conf->bypass_count -= conf->bypass_threshold;
4998 if (conf->bypass_count < 0)
4999 conf->bypass_count = 0;
5011 list_del_init(&sh->lru);
5012 BUG_ON(atomic_inc_return(&sh->count) != 1);
5016 struct raid5_plug_cb {
5017 struct blk_plug_cb cb;
5018 struct list_head list;
5019 struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS];
5022 static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
5024 struct raid5_plug_cb *cb = container_of(
5025 blk_cb, struct raid5_plug_cb, cb);
5026 struct stripe_head *sh;
5027 struct mddev *mddev = cb->cb.data;
5028 struct r5conf *conf = mddev->private;
5032 if (cb->list.next && !list_empty(&cb->list)) {
5033 spin_lock_irq(&conf->device_lock);
5034 while (!list_empty(&cb->list)) {
5035 sh = list_first_entry(&cb->list, struct stripe_head, lru);
5036 list_del_init(&sh->lru);
5038 * avoid race release_stripe_plug() sees
5039 * STRIPE_ON_UNPLUG_LIST clear but the stripe
5040 * is still in our list
5042 smp_mb__before_atomic();
5043 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
5045 * STRIPE_ON_RELEASE_LIST could be set here. In that
5046 * case, the count is always > 1 here
5048 hash = sh->hash_lock_index;
5049 __release_stripe(conf, sh, &cb->temp_inactive_list[hash]);
5052 spin_unlock_irq(&conf->device_lock);
5054 release_inactive_stripe_list(conf, cb->temp_inactive_list,
5055 NR_STRIPE_HASH_LOCKS);
5057 trace_block_unplug(mddev->queue, cnt, !from_schedule);
5061 static void release_stripe_plug(struct mddev *mddev,
5062 struct stripe_head *sh)
5064 struct blk_plug_cb *blk_cb = blk_check_plugged(
5065 raid5_unplug, mddev,
5066 sizeof(struct raid5_plug_cb));
5067 struct raid5_plug_cb *cb;
5074 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
5076 if (cb->list.next == NULL) {
5078 INIT_LIST_HEAD(&cb->list);
5079 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5080 INIT_LIST_HEAD(cb->temp_inactive_list + i);
5083 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
5084 list_add_tail(&sh->lru, &cb->list);
5089 static void make_discard_request(struct mddev *mddev, struct bio *bi)
5091 struct r5conf *conf = mddev->private;
5092 sector_t logical_sector, last_sector;
5093 struct stripe_head *sh;
5097 if (mddev->reshape_position != MaxSector)
5098 /* Skip discard while reshape is happening */
5101 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5102 last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
5105 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5107 stripe_sectors = conf->chunk_sectors *
5108 (conf->raid_disks - conf->max_degraded);
5109 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
5111 sector_div(last_sector, stripe_sectors);
5113 logical_sector *= conf->chunk_sectors;
5114 last_sector *= conf->chunk_sectors;
5116 for (; logical_sector < last_sector;
5117 logical_sector += STRIPE_SECTORS) {
5121 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
5122 prepare_to_wait(&conf->wait_for_overlap, &w,
5123 TASK_UNINTERRUPTIBLE);
5124 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5125 if (test_bit(STRIPE_SYNCING, &sh->state)) {
5130 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5131 spin_lock_irq(&sh->stripe_lock);
5132 for (d = 0; d < conf->raid_disks; d++) {
5133 if (d == sh->pd_idx || d == sh->qd_idx)
5135 if (sh->dev[d].towrite || sh->dev[d].toread) {
5136 set_bit(R5_Overlap, &sh->dev[d].flags);
5137 spin_unlock_irq(&sh->stripe_lock);
5143 set_bit(STRIPE_DISCARD, &sh->state);
5144 finish_wait(&conf->wait_for_overlap, &w);
5145 sh->overwrite_disks = 0;
5146 for (d = 0; d < conf->raid_disks; d++) {
5147 if (d == sh->pd_idx || d == sh->qd_idx)
5149 sh->dev[d].towrite = bi;
5150 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
5151 raid5_inc_bi_active_stripes(bi);
5152 sh->overwrite_disks++;
5154 spin_unlock_irq(&sh->stripe_lock);
5155 if (conf->mddev->bitmap) {
5157 d < conf->raid_disks - conf->max_degraded;
5159 bitmap_startwrite(mddev->bitmap,
5163 sh->bm_seq = conf->seq_flush + 1;
5164 set_bit(STRIPE_BIT_DELAY, &sh->state);
5167 set_bit(STRIPE_HANDLE, &sh->state);
5168 clear_bit(STRIPE_DELAYED, &sh->state);
5169 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5170 atomic_inc(&conf->preread_active_stripes);
5171 release_stripe_plug(mddev, sh);
5174 remaining = raid5_dec_bi_active_stripes(bi);
5175 if (remaining == 0) {
5176 md_write_end(mddev);
5181 static void make_request(struct mddev *mddev, struct bio * bi)
5183 struct r5conf *conf = mddev->private;
5185 sector_t new_sector;
5186 sector_t logical_sector, last_sector;
5187 struct stripe_head *sh;
5188 const int rw = bio_data_dir(bi);
5193 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
5194 md_flush_request(mddev, bi);
5198 md_write_start(mddev, bi);
5201 * If array is degraded, better not do chunk aligned read because
5202 * later we might have to read it again in order to reconstruct
5203 * data on failed drives.
5205 if (rw == READ && mddev->degraded == 0 &&
5206 mddev->reshape_position == MaxSector &&
5207 chunk_aligned_read(mddev,bi))
5210 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
5211 make_discard_request(mddev, bi);
5215 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5216 last_sector = bio_end_sector(bi);
5218 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5220 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
5221 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
5227 seq = read_seqcount_begin(&conf->gen_lock);
5230 prepare_to_wait(&conf->wait_for_overlap, &w,
5231 TASK_UNINTERRUPTIBLE);
5232 if (unlikely(conf->reshape_progress != MaxSector)) {
5233 /* spinlock is needed as reshape_progress may be
5234 * 64bit on a 32bit platform, and so it might be
5235 * possible to see a half-updated value
5236 * Of course reshape_progress could change after
5237 * the lock is dropped, so once we get a reference
5238 * to the stripe that we think it is, we will have
5241 spin_lock_irq(&conf->device_lock);
5242 if (mddev->reshape_backwards
5243 ? logical_sector < conf->reshape_progress
5244 : logical_sector >= conf->reshape_progress) {
5247 if (mddev->reshape_backwards
5248 ? logical_sector < conf->reshape_safe
5249 : logical_sector >= conf->reshape_safe) {
5250 spin_unlock_irq(&conf->device_lock);
5256 spin_unlock_irq(&conf->device_lock);
5259 new_sector = raid5_compute_sector(conf, logical_sector,
5262 pr_debug("raid456: make_request, sector %llu logical %llu\n",
5263 (unsigned long long)new_sector,
5264 (unsigned long long)logical_sector);
5266 sh = get_active_stripe(conf, new_sector, previous,
5267 (bi->bi_rw&RWA_MASK), 0);
5269 if (unlikely(previous)) {
5270 /* expansion might have moved on while waiting for a
5271 * stripe, so we must do the range check again.
5272 * Expansion could still move past after this
5273 * test, but as we are holding a reference to
5274 * 'sh', we know that if that happens,
5275 * STRIPE_EXPANDING will get set and the expansion
5276 * won't proceed until we finish with the stripe.
5279 spin_lock_irq(&conf->device_lock);
5280 if (mddev->reshape_backwards
5281 ? logical_sector >= conf->reshape_progress
5282 : logical_sector < conf->reshape_progress)
5283 /* mismatch, need to try again */
5285 spin_unlock_irq(&conf->device_lock);
5293 if (read_seqcount_retry(&conf->gen_lock, seq)) {
5294 /* Might have got the wrong stripe_head
5302 logical_sector >= mddev->suspend_lo &&
5303 logical_sector < mddev->suspend_hi) {
5305 /* As the suspend_* range is controlled by
5306 * userspace, we want an interruptible
5309 flush_signals(current);
5310 prepare_to_wait(&conf->wait_for_overlap,
5311 &w, TASK_INTERRUPTIBLE);
5312 if (logical_sector >= mddev->suspend_lo &&
5313 logical_sector < mddev->suspend_hi) {
5320 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
5321 !add_stripe_bio(sh, bi, dd_idx, rw, previous)) {
5322 /* Stripe is busy expanding or
5323 * add failed due to overlap. Flush everything
5326 md_wakeup_thread(mddev->thread);
5332 set_bit(STRIPE_HANDLE, &sh->state);
5333 clear_bit(STRIPE_DELAYED, &sh->state);
5334 if ((!sh->batch_head || sh == sh->batch_head) &&
5335 (bi->bi_rw & REQ_SYNC) &&
5336 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5337 atomic_inc(&conf->preread_active_stripes);
5338 release_stripe_plug(mddev, sh);
5340 /* cannot get stripe for read-ahead, just give-up */
5341 clear_bit(BIO_UPTODATE, &bi->bi_flags);
5345 finish_wait(&conf->wait_for_overlap, &w);
5347 remaining = raid5_dec_bi_active_stripes(bi);
5348 if (remaining == 0) {
5351 md_write_end(mddev);
5353 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
5359 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
5361 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5363 /* reshaping is quite different to recovery/resync so it is
5364 * handled quite separately ... here.
5366 * On each call to sync_request, we gather one chunk worth of
5367 * destination stripes and flag them as expanding.
5368 * Then we find all the source stripes and request reads.
5369 * As the reads complete, handle_stripe will copy the data
5370 * into the destination stripe and release that stripe.
5372 struct r5conf *conf = mddev->private;
5373 struct stripe_head *sh;
5374 sector_t first_sector, last_sector;
5375 int raid_disks = conf->previous_raid_disks;
5376 int data_disks = raid_disks - conf->max_degraded;
5377 int new_data_disks = conf->raid_disks - conf->max_degraded;
5380 sector_t writepos, readpos, safepos;
5381 sector_t stripe_addr;
5382 int reshape_sectors;
5383 struct list_head stripes;
5385 if (sector_nr == 0) {
5386 /* If restarting in the middle, skip the initial sectors */
5387 if (mddev->reshape_backwards &&
5388 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
5389 sector_nr = raid5_size(mddev, 0, 0)
5390 - conf->reshape_progress;
5391 } else if (!mddev->reshape_backwards &&
5392 conf->reshape_progress > 0)
5393 sector_nr = conf->reshape_progress;
5394 sector_div(sector_nr, new_data_disks);
5396 mddev->curr_resync_completed = sector_nr;
5397 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5403 /* We need to process a full chunk at a time.
5404 * If old and new chunk sizes differ, we need to process the
5407 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
5408 reshape_sectors = mddev->new_chunk_sectors;
5410 reshape_sectors = mddev->chunk_sectors;
5412 /* We update the metadata at least every 10 seconds, or when
5413 * the data about to be copied would over-write the source of
5414 * the data at the front of the range. i.e. one new_stripe
5415 * along from reshape_progress new_maps to after where
5416 * reshape_safe old_maps to
5418 writepos = conf->reshape_progress;
5419 sector_div(writepos, new_data_disks);
5420 readpos = conf->reshape_progress;
5421 sector_div(readpos, data_disks);
5422 safepos = conf->reshape_safe;
5423 sector_div(safepos, data_disks);
5424 if (mddev->reshape_backwards) {
5425 writepos -= min_t(sector_t, reshape_sectors, writepos);
5426 readpos += reshape_sectors;
5427 safepos += reshape_sectors;
5429 writepos += reshape_sectors;
5430 readpos -= min_t(sector_t, reshape_sectors, readpos);
5431 safepos -= min_t(sector_t, reshape_sectors, safepos);
5434 /* Having calculated the 'writepos' possibly use it
5435 * to set 'stripe_addr' which is where we will write to.
5437 if (mddev->reshape_backwards) {
5438 BUG_ON(conf->reshape_progress == 0);
5439 stripe_addr = writepos;
5440 BUG_ON((mddev->dev_sectors &
5441 ~((sector_t)reshape_sectors - 1))
5442 - reshape_sectors - stripe_addr
5445 BUG_ON(writepos != sector_nr + reshape_sectors);
5446 stripe_addr = sector_nr;
5449 /* 'writepos' is the most advanced device address we might write.
5450 * 'readpos' is the least advanced device address we might read.
5451 * 'safepos' is the least address recorded in the metadata as having
5453 * If there is a min_offset_diff, these are adjusted either by
5454 * increasing the safepos/readpos if diff is negative, or
5455 * increasing writepos if diff is positive.
5456 * If 'readpos' is then behind 'writepos', there is no way that we can
5457 * ensure safety in the face of a crash - that must be done by userspace
5458 * making a backup of the data. So in that case there is no particular
5459 * rush to update metadata.
5460 * Otherwise if 'safepos' is behind 'writepos', then we really need to
5461 * update the metadata to advance 'safepos' to match 'readpos' so that
5462 * we can be safe in the event of a crash.
5463 * So we insist on updating metadata if safepos is behind writepos and
5464 * readpos is beyond writepos.
5465 * In any case, update the metadata every 10 seconds.
5466 * Maybe that number should be configurable, but I'm not sure it is
5467 * worth it.... maybe it could be a multiple of safemode_delay???
5469 if (conf->min_offset_diff < 0) {
5470 safepos += -conf->min_offset_diff;
5471 readpos += -conf->min_offset_diff;
5473 writepos += conf->min_offset_diff;
5475 if ((mddev->reshape_backwards
5476 ? (safepos > writepos && readpos < writepos)
5477 : (safepos < writepos && readpos > writepos)) ||
5478 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
5479 /* Cannot proceed until we've updated the superblock... */
5480 wait_event(conf->wait_for_overlap,
5481 atomic_read(&conf->reshape_stripes)==0
5482 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5483 if (atomic_read(&conf->reshape_stripes) != 0)
5485 mddev->reshape_position = conf->reshape_progress;
5486 mddev->curr_resync_completed = sector_nr;
5487 conf->reshape_checkpoint = jiffies;
5488 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5489 md_wakeup_thread(mddev->thread);
5490 wait_event(mddev->sb_wait, mddev->flags == 0 ||
5491 test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5492 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5494 spin_lock_irq(&conf->device_lock);
5495 conf->reshape_safe = mddev->reshape_position;
5496 spin_unlock_irq(&conf->device_lock);
5497 wake_up(&conf->wait_for_overlap);
5498 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5501 INIT_LIST_HEAD(&stripes);
5502 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
5504 int skipped_disk = 0;
5505 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
5506 set_bit(STRIPE_EXPANDING, &sh->state);
5507 atomic_inc(&conf->reshape_stripes);
5508 /* If any of this stripe is beyond the end of the old
5509 * array, then we need to zero those blocks
5511 for (j=sh->disks; j--;) {
5513 if (j == sh->pd_idx)
5515 if (conf->level == 6 &&
5518 s = compute_blocknr(sh, j, 0);
5519 if (s < raid5_size(mddev, 0, 0)) {
5523 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
5524 set_bit(R5_Expanded, &sh->dev[j].flags);
5525 set_bit(R5_UPTODATE, &sh->dev[j].flags);
5527 if (!skipped_disk) {
5528 set_bit(STRIPE_EXPAND_READY, &sh->state);
5529 set_bit(STRIPE_HANDLE, &sh->state);
5531 list_add(&sh->lru, &stripes);
5533 spin_lock_irq(&conf->device_lock);
5534 if (mddev->reshape_backwards)
5535 conf->reshape_progress -= reshape_sectors * new_data_disks;
5537 conf->reshape_progress += reshape_sectors * new_data_disks;
5538 spin_unlock_irq(&conf->device_lock);
5539 /* Ok, those stripe are ready. We can start scheduling
5540 * reads on the source stripes.
5541 * The source stripes are determined by mapping the first and last
5542 * block on the destination stripes.
5545 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
5548 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
5549 * new_data_disks - 1),
5551 if (last_sector >= mddev->dev_sectors)
5552 last_sector = mddev->dev_sectors - 1;
5553 while (first_sector <= last_sector) {
5554 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
5555 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
5556 set_bit(STRIPE_HANDLE, &sh->state);
5558 first_sector += STRIPE_SECTORS;
5560 /* Now that the sources are clearly marked, we can release
5561 * the destination stripes
5563 while (!list_empty(&stripes)) {
5564 sh = list_entry(stripes.next, struct stripe_head, lru);
5565 list_del_init(&sh->lru);
5568 /* If this takes us to the resync_max point where we have to pause,
5569 * then we need to write out the superblock.
5571 sector_nr += reshape_sectors;
5572 if ((sector_nr - mddev->curr_resync_completed) * 2
5573 >= mddev->resync_max - mddev->curr_resync_completed) {
5574 /* Cannot proceed until we've updated the superblock... */
5575 wait_event(conf->wait_for_overlap,
5576 atomic_read(&conf->reshape_stripes) == 0
5577 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5578 if (atomic_read(&conf->reshape_stripes) != 0)
5580 mddev->reshape_position = conf->reshape_progress;
5581 mddev->curr_resync_completed = sector_nr;
5582 conf->reshape_checkpoint = jiffies;
5583 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5584 md_wakeup_thread(mddev->thread);
5585 wait_event(mddev->sb_wait,
5586 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
5587 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5588 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5590 spin_lock_irq(&conf->device_lock);
5591 conf->reshape_safe = mddev->reshape_position;
5592 spin_unlock_irq(&conf->device_lock);
5593 wake_up(&conf->wait_for_overlap);
5594 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5597 return reshape_sectors;
5600 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5602 struct r5conf *conf = mddev->private;
5603 struct stripe_head *sh;
5604 sector_t max_sector = mddev->dev_sectors;
5605 sector_t sync_blocks;
5606 int still_degraded = 0;
5609 if (sector_nr >= max_sector) {
5610 /* just being told to finish up .. nothing much to do */
5612 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
5617 if (mddev->curr_resync < max_sector) /* aborted */
5618 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
5620 else /* completed sync */
5622 bitmap_close_sync(mddev->bitmap);
5627 /* Allow raid5_quiesce to complete */
5628 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
5630 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5631 return reshape_request(mddev, sector_nr, skipped);
5633 /* No need to check resync_max as we never do more than one
5634 * stripe, and as resync_max will always be on a chunk boundary,
5635 * if the check in md_do_sync didn't fire, there is no chance
5636 * of overstepping resync_max here
5639 /* if there is too many failed drives and we are trying
5640 * to resync, then assert that we are finished, because there is
5641 * nothing we can do.
5643 if (mddev->degraded >= conf->max_degraded &&
5644 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5645 sector_t rv = mddev->dev_sectors - sector_nr;
5649 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
5651 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
5652 sync_blocks >= STRIPE_SECTORS) {
5653 /* we can skip this block, and probably more */
5654 sync_blocks /= STRIPE_SECTORS;
5656 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
5659 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
5661 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
5663 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
5664 /* make sure we don't swamp the stripe cache if someone else
5665 * is trying to get access
5667 schedule_timeout_uninterruptible(1);
5669 /* Need to check if array will still be degraded after recovery/resync
5670 * Note in case of > 1 drive failures it's possible we're rebuilding
5671 * one drive while leaving another faulty drive in array.
5674 for (i = 0; i < conf->raid_disks; i++) {
5675 struct md_rdev *rdev = ACCESS_ONCE(conf->disks[i].rdev);
5677 if (rdev == NULL || test_bit(Faulty, &rdev->flags))
5682 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
5684 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
5685 set_bit(STRIPE_HANDLE, &sh->state);
5689 return STRIPE_SECTORS;
5692 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
5694 /* We may not be able to submit a whole bio at once as there
5695 * may not be enough stripe_heads available.
5696 * We cannot pre-allocate enough stripe_heads as we may need
5697 * more than exist in the cache (if we allow ever large chunks).
5698 * So we do one stripe head at a time and record in
5699 * ->bi_hw_segments how many have been done.
5701 * We *know* that this entire raid_bio is in one chunk, so
5702 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
5704 struct stripe_head *sh;
5706 sector_t sector, logical_sector, last_sector;
5711 logical_sector = raid_bio->bi_iter.bi_sector &
5712 ~((sector_t)STRIPE_SECTORS-1);
5713 sector = raid5_compute_sector(conf, logical_sector,
5715 last_sector = bio_end_sector(raid_bio);
5717 for (; logical_sector < last_sector;
5718 logical_sector += STRIPE_SECTORS,
5719 sector += STRIPE_SECTORS,
5722 if (scnt < raid5_bi_processed_stripes(raid_bio))
5723 /* already done this stripe */
5726 sh = get_active_stripe(conf, sector, 0, 1, 1);
5729 /* failed to get a stripe - must wait */
5730 raid5_set_bi_processed_stripes(raid_bio, scnt);
5731 conf->retry_read_aligned = raid_bio;
5735 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) {
5737 raid5_set_bi_processed_stripes(raid_bio, scnt);
5738 conf->retry_read_aligned = raid_bio;
5742 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
5747 remaining = raid5_dec_bi_active_stripes(raid_bio);
5748 if (remaining == 0) {
5749 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
5751 bio_endio(raid_bio, 0);
5753 if (atomic_dec_and_test(&conf->active_aligned_reads))
5754 wake_up(&conf->wait_for_stripe);
5758 static int handle_active_stripes(struct r5conf *conf, int group,
5759 struct r5worker *worker,
5760 struct list_head *temp_inactive_list)
5762 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
5763 int i, batch_size = 0, hash;
5764 bool release_inactive = false;
5766 while (batch_size < MAX_STRIPE_BATCH &&
5767 (sh = __get_priority_stripe(conf, group)) != NULL)
5768 batch[batch_size++] = sh;
5770 if (batch_size == 0) {
5771 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5772 if (!list_empty(temp_inactive_list + i))
5774 if (i == NR_STRIPE_HASH_LOCKS)
5776 release_inactive = true;
5778 spin_unlock_irq(&conf->device_lock);
5780 release_inactive_stripe_list(conf, temp_inactive_list,
5781 NR_STRIPE_HASH_LOCKS);
5783 if (release_inactive) {
5784 spin_lock_irq(&conf->device_lock);
5788 for (i = 0; i < batch_size; i++)
5789 handle_stripe(batch[i]);
5793 spin_lock_irq(&conf->device_lock);
5794 for (i = 0; i < batch_size; i++) {
5795 hash = batch[i]->hash_lock_index;
5796 __release_stripe(conf, batch[i], &temp_inactive_list[hash]);
5801 static void raid5_do_work(struct work_struct *work)
5803 struct r5worker *worker = container_of(work, struct r5worker, work);
5804 struct r5worker_group *group = worker->group;
5805 struct r5conf *conf = group->conf;
5806 int group_id = group - conf->worker_groups;
5808 struct blk_plug plug;
5810 pr_debug("+++ raid5worker active\n");
5812 blk_start_plug(&plug);
5814 spin_lock_irq(&conf->device_lock);
5816 int batch_size, released;
5818 released = release_stripe_list(conf, worker->temp_inactive_list);
5820 batch_size = handle_active_stripes(conf, group_id, worker,
5821 worker->temp_inactive_list);
5822 worker->working = false;
5823 if (!batch_size && !released)
5825 handled += batch_size;
5827 pr_debug("%d stripes handled\n", handled);
5829 spin_unlock_irq(&conf->device_lock);
5830 blk_finish_plug(&plug);
5832 pr_debug("--- raid5worker inactive\n");
5836 * This is our raid5 kernel thread.
5838 * We scan the hash table for stripes which can be handled now.
5839 * During the scan, completed stripes are saved for us by the interrupt
5840 * handler, so that they will not have to wait for our next wakeup.
5842 static void raid5d(struct md_thread *thread)
5844 struct mddev *mddev = thread->mddev;
5845 struct r5conf *conf = mddev->private;
5847 struct blk_plug plug;
5849 pr_debug("+++ raid5d active\n");
5851 md_check_recovery(mddev);
5853 blk_start_plug(&plug);
5855 spin_lock_irq(&conf->device_lock);
5858 int batch_size, released;
5860 released = release_stripe_list(conf, conf->temp_inactive_list);
5862 clear_bit(R5_DID_ALLOC, &conf->cache_state);
5865 !list_empty(&conf->bitmap_list)) {
5866 /* Now is a good time to flush some bitmap updates */
5868 spin_unlock_irq(&conf->device_lock);
5869 bitmap_unplug(mddev->bitmap);
5870 spin_lock_irq(&conf->device_lock);
5871 conf->seq_write = conf->seq_flush;
5872 activate_bit_delay(conf, conf->temp_inactive_list);
5874 raid5_activate_delayed(conf);
5876 while ((bio = remove_bio_from_retry(conf))) {
5878 spin_unlock_irq(&conf->device_lock);
5879 ok = retry_aligned_read(conf, bio);
5880 spin_lock_irq(&conf->device_lock);
5886 batch_size = handle_active_stripes(conf, ANY_GROUP, NULL,
5887 conf->temp_inactive_list);
5888 if (!batch_size && !released)
5890 handled += batch_size;
5892 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
5893 spin_unlock_irq(&conf->device_lock);
5894 md_check_recovery(mddev);
5895 spin_lock_irq(&conf->device_lock);
5898 pr_debug("%d stripes handled\n", handled);
5900 spin_unlock_irq(&conf->device_lock);
5901 if (test_and_clear_bit(R5_ALLOC_MORE, &conf->cache_state)) {
5902 grow_one_stripe(conf, __GFP_NOWARN);
5903 /* Set flag even if allocation failed. This helps
5904 * slow down allocation requests when mem is short
5906 set_bit(R5_DID_ALLOC, &conf->cache_state);
5909 async_tx_issue_pending_all();
5910 blk_finish_plug(&plug);
5912 pr_debug("--- raid5d inactive\n");
5916 raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
5918 struct r5conf *conf;
5920 spin_lock(&mddev->lock);
5921 conf = mddev->private;
5923 ret = sprintf(page, "%d\n", conf->min_nr_stripes);
5924 spin_unlock(&mddev->lock);
5929 raid5_set_cache_size(struct mddev *mddev, int size)
5931 struct r5conf *conf = mddev->private;
5934 if (size <= 16 || size > 32768)
5937 conf->min_nr_stripes = size;
5938 while (size < conf->max_nr_stripes &&
5939 drop_one_stripe(conf))
5943 err = md_allow_write(mddev);
5947 while (size > conf->max_nr_stripes)
5948 if (!grow_one_stripe(conf, GFP_KERNEL))
5953 EXPORT_SYMBOL(raid5_set_cache_size);
5956 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
5958 struct r5conf *conf;
5962 if (len >= PAGE_SIZE)
5964 if (kstrtoul(page, 10, &new))
5966 err = mddev_lock(mddev);
5969 conf = mddev->private;
5973 err = raid5_set_cache_size(mddev, new);
5974 mddev_unlock(mddev);
5979 static struct md_sysfs_entry
5980 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
5981 raid5_show_stripe_cache_size,
5982 raid5_store_stripe_cache_size);
5985 raid5_show_rmw_level(struct mddev *mddev, char *page)
5987 struct r5conf *conf = mddev->private;
5989 return sprintf(page, "%d\n", conf->rmw_level);
5995 raid5_store_rmw_level(struct mddev *mddev, const char *page, size_t len)
5997 struct r5conf *conf = mddev->private;
6003 if (len >= PAGE_SIZE)
6006 if (kstrtoul(page, 10, &new))
6009 if (new != PARITY_DISABLE_RMW && !raid6_call.xor_syndrome)
6012 if (new != PARITY_DISABLE_RMW &&
6013 new != PARITY_ENABLE_RMW &&
6014 new != PARITY_PREFER_RMW)
6017 conf->rmw_level = new;
6021 static struct md_sysfs_entry
6022 raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR,
6023 raid5_show_rmw_level,
6024 raid5_store_rmw_level);
6028 raid5_show_preread_threshold(struct mddev *mddev, char *page)
6030 struct r5conf *conf;
6032 spin_lock(&mddev->lock);
6033 conf = mddev->private;
6035 ret = sprintf(page, "%d\n", conf->bypass_threshold);
6036 spin_unlock(&mddev->lock);
6041 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
6043 struct r5conf *conf;
6047 if (len >= PAGE_SIZE)
6049 if (kstrtoul(page, 10, &new))
6052 err = mddev_lock(mddev);
6055 conf = mddev->private;
6058 else if (new > conf->min_nr_stripes)
6061 conf->bypass_threshold = new;
6062 mddev_unlock(mddev);
6066 static struct md_sysfs_entry
6067 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
6069 raid5_show_preread_threshold,
6070 raid5_store_preread_threshold);
6073 raid5_show_skip_copy(struct mddev *mddev, char *page)
6075 struct r5conf *conf;
6077 spin_lock(&mddev->lock);
6078 conf = mddev->private;
6080 ret = sprintf(page, "%d\n", conf->skip_copy);
6081 spin_unlock(&mddev->lock);
6086 raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len)
6088 struct r5conf *conf;
6092 if (len >= PAGE_SIZE)
6094 if (kstrtoul(page, 10, &new))
6098 err = mddev_lock(mddev);
6101 conf = mddev->private;
6104 else if (new != conf->skip_copy) {
6105 mddev_suspend(mddev);
6106 conf->skip_copy = new;
6108 mddev->queue->backing_dev_info.capabilities |=
6109 BDI_CAP_STABLE_WRITES;
6111 mddev->queue->backing_dev_info.capabilities &=
6112 ~BDI_CAP_STABLE_WRITES;
6113 mddev_resume(mddev);
6115 mddev_unlock(mddev);
6119 static struct md_sysfs_entry
6120 raid5_skip_copy = __ATTR(skip_copy, S_IRUGO | S_IWUSR,
6121 raid5_show_skip_copy,
6122 raid5_store_skip_copy);
6125 stripe_cache_active_show(struct mddev *mddev, char *page)
6127 struct r5conf *conf = mddev->private;
6129 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
6134 static struct md_sysfs_entry
6135 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
6138 raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
6140 struct r5conf *conf;
6142 spin_lock(&mddev->lock);
6143 conf = mddev->private;
6145 ret = sprintf(page, "%d\n", conf->worker_cnt_per_group);
6146 spin_unlock(&mddev->lock);
6150 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6152 int *worker_cnt_per_group,
6153 struct r5worker_group **worker_groups);
6155 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
6157 struct r5conf *conf;
6160 struct r5worker_group *new_groups, *old_groups;
6161 int group_cnt, worker_cnt_per_group;
6163 if (len >= PAGE_SIZE)
6165 if (kstrtoul(page, 10, &new))
6168 err = mddev_lock(mddev);
6171 conf = mddev->private;
6174 else if (new != conf->worker_cnt_per_group) {
6175 mddev_suspend(mddev);
6177 old_groups = conf->worker_groups;
6179 flush_workqueue(raid5_wq);
6181 err = alloc_thread_groups(conf, new,
6182 &group_cnt, &worker_cnt_per_group,
6185 spin_lock_irq(&conf->device_lock);
6186 conf->group_cnt = group_cnt;
6187 conf->worker_cnt_per_group = worker_cnt_per_group;
6188 conf->worker_groups = new_groups;
6189 spin_unlock_irq(&conf->device_lock);
6192 kfree(old_groups[0].workers);
6195 mddev_resume(mddev);
6197 mddev_unlock(mddev);
6202 static struct md_sysfs_entry
6203 raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
6204 raid5_show_group_thread_cnt,
6205 raid5_store_group_thread_cnt);
6207 static struct attribute *raid5_attrs[] = {
6208 &raid5_stripecache_size.attr,
6209 &raid5_stripecache_active.attr,
6210 &raid5_preread_bypass_threshold.attr,
6211 &raid5_group_thread_cnt.attr,
6212 &raid5_skip_copy.attr,
6213 &raid5_rmw_level.attr,
6216 static struct attribute_group raid5_attrs_group = {
6218 .attrs = raid5_attrs,
6221 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6223 int *worker_cnt_per_group,
6224 struct r5worker_group **worker_groups)
6228 struct r5worker *workers;
6230 *worker_cnt_per_group = cnt;
6233 *worker_groups = NULL;
6236 *group_cnt = num_possible_nodes();
6237 size = sizeof(struct r5worker) * cnt;
6238 workers = kzalloc(size * *group_cnt, GFP_NOIO);
6239 *worker_groups = kzalloc(sizeof(struct r5worker_group) *
6240 *group_cnt, GFP_NOIO);
6241 if (!*worker_groups || !workers) {
6243 kfree(*worker_groups);
6247 for (i = 0; i < *group_cnt; i++) {
6248 struct r5worker_group *group;
6250 group = &(*worker_groups)[i];
6251 INIT_LIST_HEAD(&group->handle_list);
6253 group->workers = workers + i * cnt;
6255 for (j = 0; j < cnt; j++) {
6256 struct r5worker *worker = group->workers + j;
6257 worker->group = group;
6258 INIT_WORK(&worker->work, raid5_do_work);
6260 for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++)
6261 INIT_LIST_HEAD(worker->temp_inactive_list + k);
6268 static void free_thread_groups(struct r5conf *conf)
6270 if (conf->worker_groups)
6271 kfree(conf->worker_groups[0].workers);
6272 kfree(conf->worker_groups);
6273 conf->worker_groups = NULL;
6277 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
6279 struct r5conf *conf = mddev->private;
6282 sectors = mddev->dev_sectors;
6284 /* size is defined by the smallest of previous and new size */
6285 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
6287 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
6288 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
6289 return sectors * (raid_disks - conf->max_degraded);
6292 static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6294 safe_put_page(percpu->spare_page);
6295 if (percpu->scribble)
6296 flex_array_free(percpu->scribble);
6297 percpu->spare_page = NULL;
6298 percpu->scribble = NULL;
6301 static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6303 if (conf->level == 6 && !percpu->spare_page)
6304 percpu->spare_page = alloc_page(GFP_KERNEL);
6305 if (!percpu->scribble)
6306 percpu->scribble = scribble_alloc(max(conf->raid_disks,
6307 conf->previous_raid_disks),
6308 max(conf->chunk_sectors,
6309 conf->prev_chunk_sectors)
6313 if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
6314 free_scratch_buffer(conf, percpu);
6321 static void raid5_free_percpu(struct r5conf *conf)
6328 #ifdef CONFIG_HOTPLUG_CPU
6329 unregister_cpu_notifier(&conf->cpu_notify);
6333 for_each_possible_cpu(cpu)
6334 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6337 free_percpu(conf->percpu);
6340 static void free_conf(struct r5conf *conf)
6342 if (conf->shrinker.seeks)
6343 unregister_shrinker(&conf->shrinker);
6344 free_thread_groups(conf);
6345 shrink_stripes(conf);
6346 raid5_free_percpu(conf);
6348 kfree(conf->stripe_hashtbl);
6352 #ifdef CONFIG_HOTPLUG_CPU
6353 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
6356 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
6357 long cpu = (long)hcpu;
6358 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
6361 case CPU_UP_PREPARE:
6362 case CPU_UP_PREPARE_FROZEN:
6363 if (alloc_scratch_buffer(conf, percpu)) {
6364 pr_err("%s: failed memory allocation for cpu%ld\n",
6366 return notifier_from_errno(-ENOMEM);
6370 case CPU_DEAD_FROZEN:
6371 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6380 static int raid5_alloc_percpu(struct r5conf *conf)
6385 conf->percpu = alloc_percpu(struct raid5_percpu);
6389 #ifdef CONFIG_HOTPLUG_CPU
6390 conf->cpu_notify.notifier_call = raid456_cpu_notify;
6391 conf->cpu_notify.priority = 0;
6392 err = register_cpu_notifier(&conf->cpu_notify);
6398 for_each_present_cpu(cpu) {
6399 err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6401 pr_err("%s: failed memory allocation for cpu%ld\n",
6411 static unsigned long raid5_cache_scan(struct shrinker *shrink,
6412 struct shrink_control *sc)
6414 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6416 while (ret < sc->nr_to_scan) {
6417 if (drop_one_stripe(conf) == 0)
6424 static unsigned long raid5_cache_count(struct shrinker *shrink,
6425 struct shrink_control *sc)
6427 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6429 if (conf->max_nr_stripes < conf->min_nr_stripes)
6430 /* unlikely, but not impossible */
6432 return conf->max_nr_stripes - conf->min_nr_stripes;
6435 static struct r5conf *setup_conf(struct mddev *mddev)
6437 struct r5conf *conf;
6438 int raid_disk, memory, max_disks;
6439 struct md_rdev *rdev;
6440 struct disk_info *disk;
6443 int group_cnt, worker_cnt_per_group;
6444 struct r5worker_group *new_group;
6446 if (mddev->new_level != 5
6447 && mddev->new_level != 4
6448 && mddev->new_level != 6) {
6449 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
6450 mdname(mddev), mddev->new_level);
6451 return ERR_PTR(-EIO);
6453 if ((mddev->new_level == 5
6454 && !algorithm_valid_raid5(mddev->new_layout)) ||
6455 (mddev->new_level == 6
6456 && !algorithm_valid_raid6(mddev->new_layout))) {
6457 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
6458 mdname(mddev), mddev->new_layout);
6459 return ERR_PTR(-EIO);
6461 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
6462 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
6463 mdname(mddev), mddev->raid_disks);
6464 return ERR_PTR(-EINVAL);
6467 if (!mddev->new_chunk_sectors ||
6468 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
6469 !is_power_of_2(mddev->new_chunk_sectors)) {
6470 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
6471 mdname(mddev), mddev->new_chunk_sectors << 9);
6472 return ERR_PTR(-EINVAL);
6475 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
6478 /* Don't enable multi-threading by default*/
6479 if (!alloc_thread_groups(conf, 0, &group_cnt, &worker_cnt_per_group,
6481 conf->group_cnt = group_cnt;
6482 conf->worker_cnt_per_group = worker_cnt_per_group;
6483 conf->worker_groups = new_group;
6486 spin_lock_init(&conf->device_lock);
6487 seqcount_init(&conf->gen_lock);
6488 init_waitqueue_head(&conf->wait_for_stripe);
6489 init_waitqueue_head(&conf->wait_for_overlap);
6490 INIT_LIST_HEAD(&conf->handle_list);
6491 INIT_LIST_HEAD(&conf->hold_list);
6492 INIT_LIST_HEAD(&conf->delayed_list);
6493 INIT_LIST_HEAD(&conf->bitmap_list);
6494 init_llist_head(&conf->released_stripes);
6495 atomic_set(&conf->active_stripes, 0);
6496 atomic_set(&conf->preread_active_stripes, 0);
6497 atomic_set(&conf->active_aligned_reads, 0);
6498 conf->bypass_threshold = BYPASS_THRESHOLD;
6499 conf->recovery_disabled = mddev->recovery_disabled - 1;
6501 conf->raid_disks = mddev->raid_disks;
6502 if (mddev->reshape_position == MaxSector)
6503 conf->previous_raid_disks = mddev->raid_disks;
6505 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
6506 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
6508 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
6513 conf->mddev = mddev;
6515 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
6518 /* We init hash_locks[0] separately to that it can be used
6519 * as the reference lock in the spin_lock_nest_lock() call
6520 * in lock_all_device_hash_locks_irq in order to convince
6521 * lockdep that we know what we are doing.
6523 spin_lock_init(conf->hash_locks);
6524 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
6525 spin_lock_init(conf->hash_locks + i);
6527 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6528 INIT_LIST_HEAD(conf->inactive_list + i);
6530 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6531 INIT_LIST_HEAD(conf->temp_inactive_list + i);
6533 conf->level = mddev->new_level;
6534 conf->chunk_sectors = mddev->new_chunk_sectors;
6535 if (raid5_alloc_percpu(conf) != 0)
6538 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
6540 rdev_for_each(rdev, mddev) {
6541 raid_disk = rdev->raid_disk;
6542 if (raid_disk >= max_disks
6545 disk = conf->disks + raid_disk;
6547 if (test_bit(Replacement, &rdev->flags)) {
6548 if (disk->replacement)
6550 disk->replacement = rdev;
6557 if (test_bit(In_sync, &rdev->flags)) {
6558 char b[BDEVNAME_SIZE];
6559 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
6561 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
6562 } else if (rdev->saved_raid_disk != raid_disk)
6563 /* Cannot rely on bitmap to complete recovery */
6567 conf->level = mddev->new_level;
6568 if (conf->level == 6) {
6569 conf->max_degraded = 2;
6570 if (raid6_call.xor_syndrome)
6571 conf->rmw_level = PARITY_ENABLE_RMW;
6573 conf->rmw_level = PARITY_DISABLE_RMW;
6575 conf->max_degraded = 1;
6576 conf->rmw_level = PARITY_ENABLE_RMW;
6578 conf->algorithm = mddev->new_layout;
6579 conf->reshape_progress = mddev->reshape_position;
6580 if (conf->reshape_progress != MaxSector) {
6581 conf->prev_chunk_sectors = mddev->chunk_sectors;
6582 conf->prev_algo = mddev->layout;
6585 conf->min_nr_stripes = NR_STRIPES;
6586 memory = conf->min_nr_stripes * (sizeof(struct stripe_head) +
6587 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
6588 atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
6589 if (grow_stripes(conf, conf->min_nr_stripes)) {
6591 "md/raid:%s: couldn't allocate %dkB for buffers\n",
6592 mdname(mddev), memory);
6595 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
6596 mdname(mddev), memory);
6598 * Losing a stripe head costs more than the time to refill it,
6599 * it reduces the queue depth and so can hurt throughput.
6600 * So set it rather large, scaled by number of devices.
6602 conf->shrinker.seeks = DEFAULT_SEEKS * conf->raid_disks * 4;
6603 conf->shrinker.scan_objects = raid5_cache_scan;
6604 conf->shrinker.count_objects = raid5_cache_count;
6605 conf->shrinker.batch = 128;
6606 conf->shrinker.flags = 0;
6607 register_shrinker(&conf->shrinker);
6609 sprintf(pers_name, "raid%d", mddev->new_level);
6610 conf->thread = md_register_thread(raid5d, mddev, pers_name);
6611 if (!conf->thread) {
6613 "md/raid:%s: couldn't allocate thread.\n",
6623 return ERR_PTR(-EIO);
6625 return ERR_PTR(-ENOMEM);
6628 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
6631 case ALGORITHM_PARITY_0:
6632 if (raid_disk < max_degraded)
6635 case ALGORITHM_PARITY_N:
6636 if (raid_disk >= raid_disks - max_degraded)
6639 case ALGORITHM_PARITY_0_6:
6640 if (raid_disk == 0 ||
6641 raid_disk == raid_disks - 1)
6644 case ALGORITHM_LEFT_ASYMMETRIC_6:
6645 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6646 case ALGORITHM_LEFT_SYMMETRIC_6:
6647 case ALGORITHM_RIGHT_SYMMETRIC_6:
6648 if (raid_disk == raid_disks - 1)
6654 static int run(struct mddev *mddev)
6656 struct r5conf *conf;
6657 int working_disks = 0;
6658 int dirty_parity_disks = 0;
6659 struct md_rdev *rdev;
6660 sector_t reshape_offset = 0;
6662 long long min_offset_diff = 0;
6665 if (mddev->recovery_cp != MaxSector)
6666 printk(KERN_NOTICE "md/raid:%s: not clean"
6667 " -- starting background reconstruction\n",
6670 rdev_for_each(rdev, mddev) {
6672 if (rdev->raid_disk < 0)
6674 diff = (rdev->new_data_offset - rdev->data_offset);
6676 min_offset_diff = diff;
6678 } else if (mddev->reshape_backwards &&
6679 diff < min_offset_diff)
6680 min_offset_diff = diff;
6681 else if (!mddev->reshape_backwards &&
6682 diff > min_offset_diff)
6683 min_offset_diff = diff;
6686 if (mddev->reshape_position != MaxSector) {
6687 /* Check that we can continue the reshape.
6688 * Difficulties arise if the stripe we would write to
6689 * next is at or after the stripe we would read from next.
6690 * For a reshape that changes the number of devices, this
6691 * is only possible for a very short time, and mdadm makes
6692 * sure that time appears to have past before assembling
6693 * the array. So we fail if that time hasn't passed.
6694 * For a reshape that keeps the number of devices the same
6695 * mdadm must be monitoring the reshape can keeping the
6696 * critical areas read-only and backed up. It will start
6697 * the array in read-only mode, so we check for that.
6699 sector_t here_new, here_old;
6701 int max_degraded = (mddev->level == 6 ? 2 : 1);
6703 if (mddev->new_level != mddev->level) {
6704 printk(KERN_ERR "md/raid:%s: unsupported reshape "
6705 "required - aborting.\n",
6709 old_disks = mddev->raid_disks - mddev->delta_disks;
6710 /* reshape_position must be on a new-stripe boundary, and one
6711 * further up in new geometry must map after here in old
6714 here_new = mddev->reshape_position;
6715 if (sector_div(here_new, mddev->new_chunk_sectors *
6716 (mddev->raid_disks - max_degraded))) {
6717 printk(KERN_ERR "md/raid:%s: reshape_position not "
6718 "on a stripe boundary\n", mdname(mddev));
6721 reshape_offset = here_new * mddev->new_chunk_sectors;
6722 /* here_new is the stripe we will write to */
6723 here_old = mddev->reshape_position;
6724 sector_div(here_old, mddev->chunk_sectors *
6725 (old_disks-max_degraded));
6726 /* here_old is the first stripe that we might need to read
6728 if (mddev->delta_disks == 0) {
6729 if ((here_new * mddev->new_chunk_sectors !=
6730 here_old * mddev->chunk_sectors)) {
6731 printk(KERN_ERR "md/raid:%s: reshape position is"
6732 " confused - aborting\n", mdname(mddev));
6735 /* We cannot be sure it is safe to start an in-place
6736 * reshape. It is only safe if user-space is monitoring
6737 * and taking constant backups.
6738 * mdadm always starts a situation like this in
6739 * readonly mode so it can take control before
6740 * allowing any writes. So just check for that.
6742 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
6743 abs(min_offset_diff) >= mddev->new_chunk_sectors)
6744 /* not really in-place - so OK */;
6745 else if (mddev->ro == 0) {
6746 printk(KERN_ERR "md/raid:%s: in-place reshape "
6747 "must be started in read-only mode "
6752 } else if (mddev->reshape_backwards
6753 ? (here_new * mddev->new_chunk_sectors + min_offset_diff <=
6754 here_old * mddev->chunk_sectors)
6755 : (here_new * mddev->new_chunk_sectors >=
6756 here_old * mddev->chunk_sectors + (-min_offset_diff))) {
6757 /* Reading from the same stripe as writing to - bad */
6758 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
6759 "auto-recovery - aborting.\n",
6763 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
6765 /* OK, we should be able to continue; */
6767 BUG_ON(mddev->level != mddev->new_level);
6768 BUG_ON(mddev->layout != mddev->new_layout);
6769 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
6770 BUG_ON(mddev->delta_disks != 0);
6773 if (mddev->private == NULL)
6774 conf = setup_conf(mddev);
6776 conf = mddev->private;
6779 return PTR_ERR(conf);
6781 conf->min_offset_diff = min_offset_diff;
6782 mddev->thread = conf->thread;
6783 conf->thread = NULL;
6784 mddev->private = conf;
6786 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
6788 rdev = conf->disks[i].rdev;
6789 if (!rdev && conf->disks[i].replacement) {
6790 /* The replacement is all we have yet */
6791 rdev = conf->disks[i].replacement;
6792 conf->disks[i].replacement = NULL;
6793 clear_bit(Replacement, &rdev->flags);
6794 conf->disks[i].rdev = rdev;
6798 if (conf->disks[i].replacement &&
6799 conf->reshape_progress != MaxSector) {
6800 /* replacements and reshape simply do not mix. */
6801 printk(KERN_ERR "md: cannot handle concurrent "
6802 "replacement and reshape.\n");
6805 if (test_bit(In_sync, &rdev->flags)) {
6809 /* This disc is not fully in-sync. However if it
6810 * just stored parity (beyond the recovery_offset),
6811 * when we don't need to be concerned about the
6812 * array being dirty.
6813 * When reshape goes 'backwards', we never have
6814 * partially completed devices, so we only need
6815 * to worry about reshape going forwards.
6817 /* Hack because v0.91 doesn't store recovery_offset properly. */
6818 if (mddev->major_version == 0 &&
6819 mddev->minor_version > 90)
6820 rdev->recovery_offset = reshape_offset;
6822 if (rdev->recovery_offset < reshape_offset) {
6823 /* We need to check old and new layout */
6824 if (!only_parity(rdev->raid_disk,
6827 conf->max_degraded))
6830 if (!only_parity(rdev->raid_disk,
6832 conf->previous_raid_disks,
6833 conf->max_degraded))
6835 dirty_parity_disks++;
6839 * 0 for a fully functional array, 1 or 2 for a degraded array.
6841 mddev->degraded = calc_degraded(conf);
6843 if (has_failed(conf)) {
6844 printk(KERN_ERR "md/raid:%s: not enough operational devices"
6845 " (%d/%d failed)\n",
6846 mdname(mddev), mddev->degraded, conf->raid_disks);
6850 /* device size must be a multiple of chunk size */
6851 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
6852 mddev->resync_max_sectors = mddev->dev_sectors;
6854 if (mddev->degraded > dirty_parity_disks &&
6855 mddev->recovery_cp != MaxSector) {
6856 if (mddev->ok_start_degraded)
6858 "md/raid:%s: starting dirty degraded array"
6859 " - data corruption possible.\n",
6863 "md/raid:%s: cannot start dirty degraded array.\n",
6869 if (mddev->degraded == 0)
6870 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
6871 " devices, algorithm %d\n", mdname(mddev), conf->level,
6872 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
6875 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
6876 " out of %d devices, algorithm %d\n",
6877 mdname(mddev), conf->level,
6878 mddev->raid_disks - mddev->degraded,
6879 mddev->raid_disks, mddev->new_layout);
6881 print_raid5_conf(conf);
6883 if (conf->reshape_progress != MaxSector) {
6884 conf->reshape_safe = conf->reshape_progress;
6885 atomic_set(&conf->reshape_stripes, 0);
6886 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6887 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6888 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6889 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6890 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
6894 /* Ok, everything is just fine now */
6895 if (mddev->to_remove == &raid5_attrs_group)
6896 mddev->to_remove = NULL;
6897 else if (mddev->kobj.sd &&
6898 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
6900 "raid5: failed to create sysfs attributes for %s\n",
6902 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6906 bool discard_supported = true;
6907 /* read-ahead size must cover two whole stripes, which
6908 * is 2 * (datadisks) * chunksize where 'n' is the
6909 * number of raid devices
6911 int data_disks = conf->previous_raid_disks - conf->max_degraded;
6912 int stripe = data_disks *
6913 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
6914 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6915 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6917 chunk_size = mddev->chunk_sectors << 9;
6918 blk_queue_io_min(mddev->queue, chunk_size);
6919 blk_queue_io_opt(mddev->queue, chunk_size *
6920 (conf->raid_disks - conf->max_degraded));
6921 mddev->queue->limits.raid_partial_stripes_expensive = 1;
6923 * We can only discard a whole stripe. It doesn't make sense to
6924 * discard data disk but write parity disk
6926 stripe = stripe * PAGE_SIZE;
6927 /* Round up to power of 2, as discard handling
6928 * currently assumes that */
6929 while ((stripe-1) & stripe)
6930 stripe = (stripe | (stripe-1)) + 1;
6931 mddev->queue->limits.discard_alignment = stripe;
6932 mddev->queue->limits.discard_granularity = stripe;
6934 * unaligned part of discard request will be ignored, so can't
6935 * guarantee discard_zeroes_data
6937 mddev->queue->limits.discard_zeroes_data = 0;
6939 blk_queue_max_write_same_sectors(mddev->queue, 0);
6941 rdev_for_each(rdev, mddev) {
6942 disk_stack_limits(mddev->gendisk, rdev->bdev,
6943 rdev->data_offset << 9);
6944 disk_stack_limits(mddev->gendisk, rdev->bdev,
6945 rdev->new_data_offset << 9);
6947 * discard_zeroes_data is required, otherwise data
6948 * could be lost. Consider a scenario: discard a stripe
6949 * (the stripe could be inconsistent if
6950 * discard_zeroes_data is 0); write one disk of the
6951 * stripe (the stripe could be inconsistent again
6952 * depending on which disks are used to calculate
6953 * parity); the disk is broken; The stripe data of this
6956 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
6957 !bdev_get_queue(rdev->bdev)->
6958 limits.discard_zeroes_data)
6959 discard_supported = false;
6960 /* Unfortunately, discard_zeroes_data is not currently
6961 * a guarantee - just a hint. So we only allow DISCARD
6962 * if the sysadmin has confirmed that only safe devices
6963 * are in use by setting a module parameter.
6965 if (!devices_handle_discard_safely) {
6966 if (discard_supported) {
6967 pr_info("md/raid456: discard support disabled due to uncertainty.\n");
6968 pr_info("Set raid456.devices_handle_discard_safely=Y to override.\n");
6970 discard_supported = false;
6974 if (discard_supported &&
6975 mddev->queue->limits.max_discard_sectors >= stripe &&
6976 mddev->queue->limits.discard_granularity >= stripe)
6977 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
6980 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
6986 md_unregister_thread(&mddev->thread);
6987 print_raid5_conf(conf);
6989 mddev->private = NULL;
6990 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
6994 static void raid5_free(struct mddev *mddev, void *priv)
6996 struct r5conf *conf = priv;
6999 mddev->to_remove = &raid5_attrs_group;
7002 static void status(struct seq_file *seq, struct mddev *mddev)
7004 struct r5conf *conf = mddev->private;
7007 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
7008 mddev->chunk_sectors / 2, mddev->layout);
7009 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
7010 for (i = 0; i < conf->raid_disks; i++)
7011 seq_printf (seq, "%s",
7012 conf->disks[i].rdev &&
7013 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
7014 seq_printf (seq, "]");
7017 static void print_raid5_conf (struct r5conf *conf)
7020 struct disk_info *tmp;
7022 printk(KERN_DEBUG "RAID conf printout:\n");
7024 printk("(conf==NULL)\n");
7027 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
7029 conf->raid_disks - conf->mddev->degraded);
7031 for (i = 0; i < conf->raid_disks; i++) {
7032 char b[BDEVNAME_SIZE];
7033 tmp = conf->disks + i;
7035 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
7036 i, !test_bit(Faulty, &tmp->rdev->flags),
7037 bdevname(tmp->rdev->bdev, b));
7041 static int raid5_spare_active(struct mddev *mddev)
7044 struct r5conf *conf = mddev->private;
7045 struct disk_info *tmp;
7047 unsigned long flags;
7049 for (i = 0; i < conf->raid_disks; i++) {
7050 tmp = conf->disks + i;
7051 if (tmp->replacement
7052 && tmp->replacement->recovery_offset == MaxSector
7053 && !test_bit(Faulty, &tmp->replacement->flags)
7054 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
7055 /* Replacement has just become active. */
7057 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
7060 /* Replaced device not technically faulty,
7061 * but we need to be sure it gets removed
7062 * and never re-added.
7064 set_bit(Faulty, &tmp->rdev->flags);
7065 sysfs_notify_dirent_safe(
7066 tmp->rdev->sysfs_state);
7068 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
7069 } else if (tmp->rdev
7070 && tmp->rdev->recovery_offset == MaxSector
7071 && !test_bit(Faulty, &tmp->rdev->flags)
7072 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
7074 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
7077 spin_lock_irqsave(&conf->device_lock, flags);
7078 mddev->degraded = calc_degraded(conf);
7079 spin_unlock_irqrestore(&conf->device_lock, flags);
7080 print_raid5_conf(conf);
7084 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
7086 struct r5conf *conf = mddev->private;
7088 int number = rdev->raid_disk;
7089 struct md_rdev **rdevp;
7090 struct disk_info *p = conf->disks + number;
7092 print_raid5_conf(conf);
7093 if (rdev == p->rdev)
7095 else if (rdev == p->replacement)
7096 rdevp = &p->replacement;
7100 if (number >= conf->raid_disks &&
7101 conf->reshape_progress == MaxSector)
7102 clear_bit(In_sync, &rdev->flags);
7104 if (test_bit(In_sync, &rdev->flags) ||
7105 atomic_read(&rdev->nr_pending)) {
7109 /* Only remove non-faulty devices if recovery
7112 if (!test_bit(Faulty, &rdev->flags) &&
7113 mddev->recovery_disabled != conf->recovery_disabled &&
7114 !has_failed(conf) &&
7115 (!p->replacement || p->replacement == rdev) &&
7116 number < conf->raid_disks) {
7122 if (atomic_read(&rdev->nr_pending)) {
7123 /* lost the race, try later */
7126 } else if (p->replacement) {
7127 /* We must have just cleared 'rdev' */
7128 p->rdev = p->replacement;
7129 clear_bit(Replacement, &p->replacement->flags);
7130 smp_mb(); /* Make sure other CPUs may see both as identical
7131 * but will never see neither - if they are careful
7133 p->replacement = NULL;
7134 clear_bit(WantReplacement, &rdev->flags);
7136 /* We might have just removed the Replacement as faulty-
7137 * clear the bit just in case
7139 clear_bit(WantReplacement, &rdev->flags);
7142 print_raid5_conf(conf);
7146 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
7148 struct r5conf *conf = mddev->private;
7151 struct disk_info *p;
7153 int last = conf->raid_disks - 1;
7155 if (mddev->recovery_disabled == conf->recovery_disabled)
7158 if (rdev->saved_raid_disk < 0 && has_failed(conf))
7159 /* no point adding a device */
7162 if (rdev->raid_disk >= 0)
7163 first = last = rdev->raid_disk;
7166 * find the disk ... but prefer rdev->saved_raid_disk
7169 if (rdev->saved_raid_disk >= 0 &&
7170 rdev->saved_raid_disk >= first &&
7171 conf->disks[rdev->saved_raid_disk].rdev == NULL)
7172 first = rdev->saved_raid_disk;
7174 for (disk = first; disk <= last; disk++) {
7175 p = conf->disks + disk;
7176 if (p->rdev == NULL) {
7177 clear_bit(In_sync, &rdev->flags);
7178 rdev->raid_disk = disk;
7180 if (rdev->saved_raid_disk != disk)
7182 rcu_assign_pointer(p->rdev, rdev);
7186 for (disk = first; disk <= last; disk++) {
7187 p = conf->disks + disk;
7188 if (test_bit(WantReplacement, &p->rdev->flags) &&
7189 p->replacement == NULL) {
7190 clear_bit(In_sync, &rdev->flags);
7191 set_bit(Replacement, &rdev->flags);
7192 rdev->raid_disk = disk;
7195 rcu_assign_pointer(p->replacement, rdev);
7200 print_raid5_conf(conf);
7204 static int raid5_resize(struct mddev *mddev, sector_t sectors)
7206 /* no resync is happening, and there is enough space
7207 * on all devices, so we can resize.
7208 * We need to make sure resync covers any new space.
7209 * If the array is shrinking we should possibly wait until
7210 * any io in the removed space completes, but it hardly seems
7214 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
7215 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
7216 if (mddev->external_size &&
7217 mddev->array_sectors > newsize)
7219 if (mddev->bitmap) {
7220 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
7224 md_set_array_sectors(mddev, newsize);
7225 set_capacity(mddev->gendisk, mddev->array_sectors);
7226 revalidate_disk(mddev->gendisk);
7227 if (sectors > mddev->dev_sectors &&
7228 mddev->recovery_cp > mddev->dev_sectors) {
7229 mddev->recovery_cp = mddev->dev_sectors;
7230 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7232 mddev->dev_sectors = sectors;
7233 mddev->resync_max_sectors = sectors;
7237 static int check_stripe_cache(struct mddev *mddev)
7239 /* Can only proceed if there are plenty of stripe_heads.
7240 * We need a minimum of one full stripe,, and for sensible progress
7241 * it is best to have about 4 times that.
7242 * If we require 4 times, then the default 256 4K stripe_heads will
7243 * allow for chunk sizes up to 256K, which is probably OK.
7244 * If the chunk size is greater, user-space should request more
7245 * stripe_heads first.
7247 struct r5conf *conf = mddev->private;
7248 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
7249 > conf->min_nr_stripes ||
7250 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
7251 > conf->min_nr_stripes) {
7252 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
7254 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
7261 static int check_reshape(struct mddev *mddev)
7263 struct r5conf *conf = mddev->private;
7265 if (mddev->delta_disks == 0 &&
7266 mddev->new_layout == mddev->layout &&
7267 mddev->new_chunk_sectors == mddev->chunk_sectors)
7268 return 0; /* nothing to do */
7269 if (has_failed(conf))
7271 if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
7272 /* We might be able to shrink, but the devices must
7273 * be made bigger first.
7274 * For raid6, 4 is the minimum size.
7275 * Otherwise 2 is the minimum
7278 if (mddev->level == 6)
7280 if (mddev->raid_disks + mddev->delta_disks < min)
7284 if (!check_stripe_cache(mddev))
7287 if (mddev->new_chunk_sectors > mddev->chunk_sectors ||
7288 mddev->delta_disks > 0)
7289 if (resize_chunks(conf,
7290 conf->previous_raid_disks
7291 + max(0, mddev->delta_disks),
7292 max(mddev->new_chunk_sectors,
7293 mddev->chunk_sectors)
7296 return resize_stripes(conf, (conf->previous_raid_disks
7297 + mddev->delta_disks));
7300 static int raid5_start_reshape(struct mddev *mddev)
7302 struct r5conf *conf = mddev->private;
7303 struct md_rdev *rdev;
7305 unsigned long flags;
7307 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
7310 if (!check_stripe_cache(mddev))
7313 if (has_failed(conf))
7316 rdev_for_each(rdev, mddev) {
7317 if (!test_bit(In_sync, &rdev->flags)
7318 && !test_bit(Faulty, &rdev->flags))
7322 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
7323 /* Not enough devices even to make a degraded array
7328 /* Refuse to reduce size of the array. Any reductions in
7329 * array size must be through explicit setting of array_size
7332 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
7333 < mddev->array_sectors) {
7334 printk(KERN_ERR "md/raid:%s: array size must be reduced "
7335 "before number of disks\n", mdname(mddev));
7339 atomic_set(&conf->reshape_stripes, 0);
7340 spin_lock_irq(&conf->device_lock);
7341 write_seqcount_begin(&conf->gen_lock);
7342 conf->previous_raid_disks = conf->raid_disks;
7343 conf->raid_disks += mddev->delta_disks;
7344 conf->prev_chunk_sectors = conf->chunk_sectors;
7345 conf->chunk_sectors = mddev->new_chunk_sectors;
7346 conf->prev_algo = conf->algorithm;
7347 conf->algorithm = mddev->new_layout;
7349 /* Code that selects data_offset needs to see the generation update
7350 * if reshape_progress has been set - so a memory barrier needed.
7353 if (mddev->reshape_backwards)
7354 conf->reshape_progress = raid5_size(mddev, 0, 0);
7356 conf->reshape_progress = 0;
7357 conf->reshape_safe = conf->reshape_progress;
7358 write_seqcount_end(&conf->gen_lock);
7359 spin_unlock_irq(&conf->device_lock);
7361 /* Now make sure any requests that proceeded on the assumption
7362 * the reshape wasn't running - like Discard or Read - have
7365 mddev_suspend(mddev);
7366 mddev_resume(mddev);
7368 /* Add some new drives, as many as will fit.
7369 * We know there are enough to make the newly sized array work.
7370 * Don't add devices if we are reducing the number of
7371 * devices in the array. This is because it is not possible
7372 * to correctly record the "partially reconstructed" state of
7373 * such devices during the reshape and confusion could result.
7375 if (mddev->delta_disks >= 0) {
7376 rdev_for_each(rdev, mddev)
7377 if (rdev->raid_disk < 0 &&
7378 !test_bit(Faulty, &rdev->flags)) {
7379 if (raid5_add_disk(mddev, rdev) == 0) {
7381 >= conf->previous_raid_disks)
7382 set_bit(In_sync, &rdev->flags);
7384 rdev->recovery_offset = 0;
7386 if (sysfs_link_rdev(mddev, rdev))
7387 /* Failure here is OK */;
7389 } else if (rdev->raid_disk >= conf->previous_raid_disks
7390 && !test_bit(Faulty, &rdev->flags)) {
7391 /* This is a spare that was manually added */
7392 set_bit(In_sync, &rdev->flags);
7395 /* When a reshape changes the number of devices,
7396 * ->degraded is measured against the larger of the
7397 * pre and post number of devices.
7399 spin_lock_irqsave(&conf->device_lock, flags);
7400 mddev->degraded = calc_degraded(conf);
7401 spin_unlock_irqrestore(&conf->device_lock, flags);
7403 mddev->raid_disks = conf->raid_disks;
7404 mddev->reshape_position = conf->reshape_progress;
7405 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7407 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7408 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7409 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7410 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7411 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
7413 if (!mddev->sync_thread) {
7414 mddev->recovery = 0;
7415 spin_lock_irq(&conf->device_lock);
7416 write_seqcount_begin(&conf->gen_lock);
7417 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
7418 mddev->new_chunk_sectors =
7419 conf->chunk_sectors = conf->prev_chunk_sectors;
7420 mddev->new_layout = conf->algorithm = conf->prev_algo;
7421 rdev_for_each(rdev, mddev)
7422 rdev->new_data_offset = rdev->data_offset;
7424 conf->generation --;
7425 conf->reshape_progress = MaxSector;
7426 mddev->reshape_position = MaxSector;
7427 write_seqcount_end(&conf->gen_lock);
7428 spin_unlock_irq(&conf->device_lock);
7431 conf->reshape_checkpoint = jiffies;
7432 md_wakeup_thread(mddev->sync_thread);
7433 md_new_event(mddev);
7437 /* This is called from the reshape thread and should make any
7438 * changes needed in 'conf'
7440 static void end_reshape(struct r5conf *conf)
7443 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
7444 struct md_rdev *rdev;
7446 spin_lock_irq(&conf->device_lock);
7447 conf->previous_raid_disks = conf->raid_disks;
7448 rdev_for_each(rdev, conf->mddev)
7449 rdev->data_offset = rdev->new_data_offset;
7451 conf->reshape_progress = MaxSector;
7452 spin_unlock_irq(&conf->device_lock);
7453 wake_up(&conf->wait_for_overlap);
7455 /* read-ahead size must cover two whole stripes, which is
7456 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
7458 if (conf->mddev->queue) {
7459 int data_disks = conf->raid_disks - conf->max_degraded;
7460 int stripe = data_disks * ((conf->chunk_sectors << 9)
7462 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
7463 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
7468 /* This is called from the raid5d thread with mddev_lock held.
7469 * It makes config changes to the device.
7471 static void raid5_finish_reshape(struct mddev *mddev)
7473 struct r5conf *conf = mddev->private;
7475 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7477 if (mddev->delta_disks > 0) {
7478 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7479 set_capacity(mddev->gendisk, mddev->array_sectors);
7480 revalidate_disk(mddev->gendisk);
7483 spin_lock_irq(&conf->device_lock);
7484 mddev->degraded = calc_degraded(conf);
7485 spin_unlock_irq(&conf->device_lock);
7486 for (d = conf->raid_disks ;
7487 d < conf->raid_disks - mddev->delta_disks;
7489 struct md_rdev *rdev = conf->disks[d].rdev;
7491 clear_bit(In_sync, &rdev->flags);
7492 rdev = conf->disks[d].replacement;
7494 clear_bit(In_sync, &rdev->flags);
7497 mddev->layout = conf->algorithm;
7498 mddev->chunk_sectors = conf->chunk_sectors;
7499 mddev->reshape_position = MaxSector;
7500 mddev->delta_disks = 0;
7501 mddev->reshape_backwards = 0;
7505 static void raid5_quiesce(struct mddev *mddev, int state)
7507 struct r5conf *conf = mddev->private;
7510 case 2: /* resume for a suspend */
7511 wake_up(&conf->wait_for_overlap);
7514 case 1: /* stop all writes */
7515 lock_all_device_hash_locks_irq(conf);
7516 /* '2' tells resync/reshape to pause so that all
7517 * active stripes can drain
7520 wait_event_cmd(conf->wait_for_stripe,
7521 atomic_read(&conf->active_stripes) == 0 &&
7522 atomic_read(&conf->active_aligned_reads) == 0,
7523 unlock_all_device_hash_locks_irq(conf),
7524 lock_all_device_hash_locks_irq(conf));
7526 unlock_all_device_hash_locks_irq(conf);
7527 /* allow reshape to continue */
7528 wake_up(&conf->wait_for_overlap);
7531 case 0: /* re-enable writes */
7532 lock_all_device_hash_locks_irq(conf);
7534 wake_up(&conf->wait_for_stripe);
7535 wake_up(&conf->wait_for_overlap);
7536 unlock_all_device_hash_locks_irq(conf);
7541 static void *raid45_takeover_raid0(struct mddev *mddev, int level)
7543 struct r0conf *raid0_conf = mddev->private;
7546 /* for raid0 takeover only one zone is supported */
7547 if (raid0_conf->nr_strip_zones > 1) {
7548 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
7550 return ERR_PTR(-EINVAL);
7553 sectors = raid0_conf->strip_zone[0].zone_end;
7554 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
7555 mddev->dev_sectors = sectors;
7556 mddev->new_level = level;
7557 mddev->new_layout = ALGORITHM_PARITY_N;
7558 mddev->new_chunk_sectors = mddev->chunk_sectors;
7559 mddev->raid_disks += 1;
7560 mddev->delta_disks = 1;
7561 /* make sure it will be not marked as dirty */
7562 mddev->recovery_cp = MaxSector;
7564 return setup_conf(mddev);
7567 static void *raid5_takeover_raid1(struct mddev *mddev)
7571 if (mddev->raid_disks != 2 ||
7572 mddev->degraded > 1)
7573 return ERR_PTR(-EINVAL);
7575 /* Should check if there are write-behind devices? */
7577 chunksect = 64*2; /* 64K by default */
7579 /* The array must be an exact multiple of chunksize */
7580 while (chunksect && (mddev->array_sectors & (chunksect-1)))
7583 if ((chunksect<<9) < STRIPE_SIZE)
7584 /* array size does not allow a suitable chunk size */
7585 return ERR_PTR(-EINVAL);
7587 mddev->new_level = 5;
7588 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
7589 mddev->new_chunk_sectors = chunksect;
7591 return setup_conf(mddev);
7594 static void *raid5_takeover_raid6(struct mddev *mddev)
7598 switch (mddev->layout) {
7599 case ALGORITHM_LEFT_ASYMMETRIC_6:
7600 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
7602 case ALGORITHM_RIGHT_ASYMMETRIC_6:
7603 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
7605 case ALGORITHM_LEFT_SYMMETRIC_6:
7606 new_layout = ALGORITHM_LEFT_SYMMETRIC;
7608 case ALGORITHM_RIGHT_SYMMETRIC_6:
7609 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
7611 case ALGORITHM_PARITY_0_6:
7612 new_layout = ALGORITHM_PARITY_0;
7614 case ALGORITHM_PARITY_N:
7615 new_layout = ALGORITHM_PARITY_N;
7618 return ERR_PTR(-EINVAL);
7620 mddev->new_level = 5;
7621 mddev->new_layout = new_layout;
7622 mddev->delta_disks = -1;
7623 mddev->raid_disks -= 1;
7624 return setup_conf(mddev);
7627 static int raid5_check_reshape(struct mddev *mddev)
7629 /* For a 2-drive array, the layout and chunk size can be changed
7630 * immediately as not restriping is needed.
7631 * For larger arrays we record the new value - after validation
7632 * to be used by a reshape pass.
7634 struct r5conf *conf = mddev->private;
7635 int new_chunk = mddev->new_chunk_sectors;
7637 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
7639 if (new_chunk > 0) {
7640 if (!is_power_of_2(new_chunk))
7642 if (new_chunk < (PAGE_SIZE>>9))
7644 if (mddev->array_sectors & (new_chunk-1))
7645 /* not factor of array size */
7649 /* They look valid */
7651 if (mddev->raid_disks == 2) {
7652 /* can make the change immediately */
7653 if (mddev->new_layout >= 0) {
7654 conf->algorithm = mddev->new_layout;
7655 mddev->layout = mddev->new_layout;
7657 if (new_chunk > 0) {
7658 conf->chunk_sectors = new_chunk ;
7659 mddev->chunk_sectors = new_chunk;
7661 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7662 md_wakeup_thread(mddev->thread);
7664 return check_reshape(mddev);
7667 static int raid6_check_reshape(struct mddev *mddev)
7669 int new_chunk = mddev->new_chunk_sectors;
7671 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
7673 if (new_chunk > 0) {
7674 if (!is_power_of_2(new_chunk))
7676 if (new_chunk < (PAGE_SIZE >> 9))
7678 if (mddev->array_sectors & (new_chunk-1))
7679 /* not factor of array size */
7683 /* They look valid */
7684 return check_reshape(mddev);
7687 static void *raid5_takeover(struct mddev *mddev)
7689 /* raid5 can take over:
7690 * raid0 - if there is only one strip zone - make it a raid4 layout
7691 * raid1 - if there are two drives. We need to know the chunk size
7692 * raid4 - trivial - just use a raid4 layout.
7693 * raid6 - Providing it is a *_6 layout
7695 if (mddev->level == 0)
7696 return raid45_takeover_raid0(mddev, 5);
7697 if (mddev->level == 1)
7698 return raid5_takeover_raid1(mddev);
7699 if (mddev->level == 4) {
7700 mddev->new_layout = ALGORITHM_PARITY_N;
7701 mddev->new_level = 5;
7702 return setup_conf(mddev);
7704 if (mddev->level == 6)
7705 return raid5_takeover_raid6(mddev);
7707 return ERR_PTR(-EINVAL);
7710 static void *raid4_takeover(struct mddev *mddev)
7712 /* raid4 can take over:
7713 * raid0 - if there is only one strip zone
7714 * raid5 - if layout is right
7716 if (mddev->level == 0)
7717 return raid45_takeover_raid0(mddev, 4);
7718 if (mddev->level == 5 &&
7719 mddev->layout == ALGORITHM_PARITY_N) {
7720 mddev->new_layout = 0;
7721 mddev->new_level = 4;
7722 return setup_conf(mddev);
7724 return ERR_PTR(-EINVAL);
7727 static struct md_personality raid5_personality;
7729 static void *raid6_takeover(struct mddev *mddev)
7731 /* Currently can only take over a raid5. We map the
7732 * personality to an equivalent raid6 personality
7733 * with the Q block at the end.
7737 if (mddev->pers != &raid5_personality)
7738 return ERR_PTR(-EINVAL);
7739 if (mddev->degraded > 1)
7740 return ERR_PTR(-EINVAL);
7741 if (mddev->raid_disks > 253)
7742 return ERR_PTR(-EINVAL);
7743 if (mddev->raid_disks < 3)
7744 return ERR_PTR(-EINVAL);
7746 switch (mddev->layout) {
7747 case ALGORITHM_LEFT_ASYMMETRIC:
7748 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
7750 case ALGORITHM_RIGHT_ASYMMETRIC:
7751 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
7753 case ALGORITHM_LEFT_SYMMETRIC:
7754 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
7756 case ALGORITHM_RIGHT_SYMMETRIC:
7757 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
7759 case ALGORITHM_PARITY_0:
7760 new_layout = ALGORITHM_PARITY_0_6;
7762 case ALGORITHM_PARITY_N:
7763 new_layout = ALGORITHM_PARITY_N;
7766 return ERR_PTR(-EINVAL);
7768 mddev->new_level = 6;
7769 mddev->new_layout = new_layout;
7770 mddev->delta_disks = 1;
7771 mddev->raid_disks += 1;
7772 return setup_conf(mddev);
7775 static struct md_personality raid6_personality =
7779 .owner = THIS_MODULE,
7780 .make_request = make_request,
7784 .error_handler = error,
7785 .hot_add_disk = raid5_add_disk,
7786 .hot_remove_disk= raid5_remove_disk,
7787 .spare_active = raid5_spare_active,
7788 .sync_request = sync_request,
7789 .resize = raid5_resize,
7791 .check_reshape = raid6_check_reshape,
7792 .start_reshape = raid5_start_reshape,
7793 .finish_reshape = raid5_finish_reshape,
7794 .quiesce = raid5_quiesce,
7795 .takeover = raid6_takeover,
7796 .congested = raid5_congested,
7797 .mergeable_bvec = raid5_mergeable_bvec,
7799 static struct md_personality raid5_personality =
7803 .owner = THIS_MODULE,
7804 .make_request = make_request,
7808 .error_handler = error,
7809 .hot_add_disk = raid5_add_disk,
7810 .hot_remove_disk= raid5_remove_disk,
7811 .spare_active = raid5_spare_active,
7812 .sync_request = sync_request,
7813 .resize = raid5_resize,
7815 .check_reshape = raid5_check_reshape,
7816 .start_reshape = raid5_start_reshape,
7817 .finish_reshape = raid5_finish_reshape,
7818 .quiesce = raid5_quiesce,
7819 .takeover = raid5_takeover,
7820 .congested = raid5_congested,
7821 .mergeable_bvec = raid5_mergeable_bvec,
7824 static struct md_personality raid4_personality =
7828 .owner = THIS_MODULE,
7829 .make_request = make_request,
7833 .error_handler = error,
7834 .hot_add_disk = raid5_add_disk,
7835 .hot_remove_disk= raid5_remove_disk,
7836 .spare_active = raid5_spare_active,
7837 .sync_request = sync_request,
7838 .resize = raid5_resize,
7840 .check_reshape = raid5_check_reshape,
7841 .start_reshape = raid5_start_reshape,
7842 .finish_reshape = raid5_finish_reshape,
7843 .quiesce = raid5_quiesce,
7844 .takeover = raid4_takeover,
7845 .congested = raid5_congested,
7846 .mergeable_bvec = raid5_mergeable_bvec,
7849 static int __init raid5_init(void)
7851 raid5_wq = alloc_workqueue("raid5wq",
7852 WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
7855 register_md_personality(&raid6_personality);
7856 register_md_personality(&raid5_personality);
7857 register_md_personality(&raid4_personality);
7861 static void raid5_exit(void)
7863 unregister_md_personality(&raid6_personality);
7864 unregister_md_personality(&raid5_personality);
7865 unregister_md_personality(&raid4_personality);
7866 destroy_workqueue(raid5_wq);
7869 module_init(raid5_init);
7870 module_exit(raid5_exit);
7871 MODULE_LICENSE("GPL");
7872 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
7873 MODULE_ALIAS("md-personality-4"); /* RAID5 */
7874 MODULE_ALIAS("md-raid5");
7875 MODULE_ALIAS("md-raid4");
7876 MODULE_ALIAS("md-level-5");
7877 MODULE_ALIAS("md-level-4");
7878 MODULE_ALIAS("md-personality-8"); /* RAID6 */
7879 MODULE_ALIAS("md-raid6");
7880 MODULE_ALIAS("md-level-6");
7882 /* This used to be two separate modules, they were: */
7883 MODULE_ALIAS("raid5");
7884 MODULE_ALIAS("raid6");