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_list *return_bi)
229 while ((bi = bio_list_pop(return_bi)) != NULL) {
230 bi->bi_iter.bi_size = 0;
231 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
237 static void print_raid5_conf (struct r5conf *conf);
239 static int stripe_operations_active(struct stripe_head *sh)
241 return sh->check_state || sh->reconstruct_state ||
242 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
243 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
246 static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
248 struct r5conf *conf = sh->raid_conf;
249 struct r5worker_group *group;
251 int i, cpu = sh->cpu;
253 if (!cpu_online(cpu)) {
254 cpu = cpumask_any(cpu_online_mask);
258 if (list_empty(&sh->lru)) {
259 struct r5worker_group *group;
260 group = conf->worker_groups + cpu_to_group(cpu);
261 list_add_tail(&sh->lru, &group->handle_list);
262 group->stripes_cnt++;
266 if (conf->worker_cnt_per_group == 0) {
267 md_wakeup_thread(conf->mddev->thread);
271 group = conf->worker_groups + cpu_to_group(sh->cpu);
273 group->workers[0].working = true;
274 /* at least one worker should run to avoid race */
275 queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
277 thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
278 /* wakeup more workers */
279 for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
280 if (group->workers[i].working == false) {
281 group->workers[i].working = true;
282 queue_work_on(sh->cpu, raid5_wq,
283 &group->workers[i].work);
289 static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
290 struct list_head *temp_inactive_list)
292 BUG_ON(!list_empty(&sh->lru));
293 BUG_ON(atomic_read(&conf->active_stripes)==0);
294 if (test_bit(STRIPE_HANDLE, &sh->state)) {
295 if (test_bit(STRIPE_DELAYED, &sh->state) &&
296 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
297 list_add_tail(&sh->lru, &conf->delayed_list);
298 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
299 sh->bm_seq - conf->seq_write > 0)
300 list_add_tail(&sh->lru, &conf->bitmap_list);
302 clear_bit(STRIPE_DELAYED, &sh->state);
303 clear_bit(STRIPE_BIT_DELAY, &sh->state);
304 if (conf->worker_cnt_per_group == 0) {
305 list_add_tail(&sh->lru, &conf->handle_list);
307 raid5_wakeup_stripe_thread(sh);
311 md_wakeup_thread(conf->mddev->thread);
313 BUG_ON(stripe_operations_active(sh));
314 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
315 if (atomic_dec_return(&conf->preread_active_stripes)
317 md_wakeup_thread(conf->mddev->thread);
318 atomic_dec(&conf->active_stripes);
319 if (!test_bit(STRIPE_EXPANDING, &sh->state))
320 list_add_tail(&sh->lru, temp_inactive_list);
324 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
325 struct list_head *temp_inactive_list)
327 if (atomic_dec_and_test(&sh->count))
328 do_release_stripe(conf, sh, temp_inactive_list);
332 * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
334 * Be careful: Only one task can add/delete stripes from temp_inactive_list at
335 * given time. Adding stripes only takes device lock, while deleting stripes
336 * only takes hash lock.
338 static void release_inactive_stripe_list(struct r5conf *conf,
339 struct list_head *temp_inactive_list,
343 unsigned long do_wakeup = 0;
347 if (hash == NR_STRIPE_HASH_LOCKS) {
348 size = NR_STRIPE_HASH_LOCKS;
349 hash = NR_STRIPE_HASH_LOCKS - 1;
353 struct list_head *list = &temp_inactive_list[size - 1];
356 * We don't hold any lock here yet, get_active_stripe() might
357 * remove stripes from the list
359 if (!list_empty_careful(list)) {
360 spin_lock_irqsave(conf->hash_locks + hash, flags);
361 if (list_empty(conf->inactive_list + hash) &&
363 atomic_dec(&conf->empty_inactive_list_nr);
364 list_splice_tail_init(list, conf->inactive_list + hash);
365 do_wakeup |= 1 << hash;
366 spin_unlock_irqrestore(conf->hash_locks + hash, flags);
372 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) {
373 if (do_wakeup & (1 << i))
374 wake_up(&conf->wait_for_stripe[i]);
378 if (atomic_read(&conf->active_stripes) == 0)
379 wake_up(&conf->wait_for_quiescent);
380 if (conf->retry_read_aligned)
381 md_wakeup_thread(conf->mddev->thread);
385 /* should hold conf->device_lock already */
386 static int release_stripe_list(struct r5conf *conf,
387 struct list_head *temp_inactive_list)
389 struct stripe_head *sh;
391 struct llist_node *head;
393 head = llist_del_all(&conf->released_stripes);
394 head = llist_reverse_order(head);
398 sh = llist_entry(head, struct stripe_head, release_list);
399 head = llist_next(head);
400 /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
402 clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
404 * Don't worry the bit is set here, because if the bit is set
405 * again, the count is always > 1. This is true for
406 * STRIPE_ON_UNPLUG_LIST bit too.
408 hash = sh->hash_lock_index;
409 __release_stripe(conf, sh, &temp_inactive_list[hash]);
416 static void release_stripe(struct stripe_head *sh)
418 struct r5conf *conf = sh->raid_conf;
420 struct list_head list;
424 /* Avoid release_list until the last reference.
426 if (atomic_add_unless(&sh->count, -1, 1))
429 if (unlikely(!conf->mddev->thread) ||
430 test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
432 wakeup = llist_add(&sh->release_list, &conf->released_stripes);
434 md_wakeup_thread(conf->mddev->thread);
437 local_irq_save(flags);
438 /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
439 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
440 INIT_LIST_HEAD(&list);
441 hash = sh->hash_lock_index;
442 do_release_stripe(conf, sh, &list);
443 spin_unlock(&conf->device_lock);
444 release_inactive_stripe_list(conf, &list, hash);
446 local_irq_restore(flags);
449 static inline void remove_hash(struct stripe_head *sh)
451 pr_debug("remove_hash(), stripe %llu\n",
452 (unsigned long long)sh->sector);
454 hlist_del_init(&sh->hash);
457 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
459 struct hlist_head *hp = stripe_hash(conf, sh->sector);
461 pr_debug("insert_hash(), stripe %llu\n",
462 (unsigned long long)sh->sector);
464 hlist_add_head(&sh->hash, hp);
467 /* find an idle stripe, make sure it is unhashed, and return it. */
468 static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash)
470 struct stripe_head *sh = NULL;
471 struct list_head *first;
473 if (list_empty(conf->inactive_list + hash))
475 first = (conf->inactive_list + hash)->next;
476 sh = list_entry(first, struct stripe_head, lru);
477 list_del_init(first);
479 atomic_inc(&conf->active_stripes);
480 BUG_ON(hash != sh->hash_lock_index);
481 if (list_empty(conf->inactive_list + hash))
482 atomic_inc(&conf->empty_inactive_list_nr);
487 static void shrink_buffers(struct stripe_head *sh)
491 int num = sh->raid_conf->pool_size;
493 for (i = 0; i < num ; i++) {
494 WARN_ON(sh->dev[i].page != sh->dev[i].orig_page);
498 sh->dev[i].page = NULL;
503 static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
506 int num = sh->raid_conf->pool_size;
508 for (i = 0; i < num; i++) {
511 if (!(page = alloc_page(gfp))) {
514 sh->dev[i].page = page;
515 sh->dev[i].orig_page = page;
520 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
521 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
522 struct stripe_head *sh);
524 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
526 struct r5conf *conf = sh->raid_conf;
529 BUG_ON(atomic_read(&sh->count) != 0);
530 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
531 BUG_ON(stripe_operations_active(sh));
532 BUG_ON(sh->batch_head);
534 pr_debug("init_stripe called, stripe %llu\n",
535 (unsigned long long)sector);
537 seq = read_seqcount_begin(&conf->gen_lock);
538 sh->generation = conf->generation - previous;
539 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
541 stripe_set_idx(sector, conf, previous, sh);
544 for (i = sh->disks; i--; ) {
545 struct r5dev *dev = &sh->dev[i];
547 if (dev->toread || dev->read || dev->towrite || dev->written ||
548 test_bit(R5_LOCKED, &dev->flags)) {
549 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
550 (unsigned long long)sh->sector, i, dev->toread,
551 dev->read, dev->towrite, dev->written,
552 test_bit(R5_LOCKED, &dev->flags));
556 raid5_build_block(sh, i, previous);
558 if (read_seqcount_retry(&conf->gen_lock, seq))
560 sh->overwrite_disks = 0;
561 insert_hash(conf, sh);
562 sh->cpu = smp_processor_id();
563 set_bit(STRIPE_BATCH_READY, &sh->state);
566 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
569 struct stripe_head *sh;
571 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
572 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
573 if (sh->sector == sector && sh->generation == generation)
575 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
580 * Need to check if array has failed when deciding whether to:
582 * - remove non-faulty devices
585 * This determination is simple when no reshape is happening.
586 * However if there is a reshape, we need to carefully check
587 * both the before and after sections.
588 * This is because some failed devices may only affect one
589 * of the two sections, and some non-in_sync devices may
590 * be insync in the section most affected by failed devices.
592 static int calc_degraded(struct r5conf *conf)
594 int degraded, degraded2;
599 for (i = 0; i < conf->previous_raid_disks; i++) {
600 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
601 if (rdev && test_bit(Faulty, &rdev->flags))
602 rdev = rcu_dereference(conf->disks[i].replacement);
603 if (!rdev || test_bit(Faulty, &rdev->flags))
605 else if (test_bit(In_sync, &rdev->flags))
608 /* not in-sync or faulty.
609 * If the reshape increases the number of devices,
610 * this is being recovered by the reshape, so
611 * this 'previous' section is not in_sync.
612 * If the number of devices is being reduced however,
613 * the device can only be part of the array if
614 * we are reverting a reshape, so this section will
617 if (conf->raid_disks >= conf->previous_raid_disks)
621 if (conf->raid_disks == conf->previous_raid_disks)
625 for (i = 0; i < conf->raid_disks; i++) {
626 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
627 if (rdev && test_bit(Faulty, &rdev->flags))
628 rdev = rcu_dereference(conf->disks[i].replacement);
629 if (!rdev || test_bit(Faulty, &rdev->flags))
631 else if (test_bit(In_sync, &rdev->flags))
634 /* not in-sync or faulty.
635 * If reshape increases the number of devices, this
636 * section has already been recovered, else it
637 * almost certainly hasn't.
639 if (conf->raid_disks <= conf->previous_raid_disks)
643 if (degraded2 > degraded)
648 static int has_failed(struct r5conf *conf)
652 if (conf->mddev->reshape_position == MaxSector)
653 return conf->mddev->degraded > conf->max_degraded;
655 degraded = calc_degraded(conf);
656 if (degraded > conf->max_degraded)
661 static struct stripe_head *
662 get_active_stripe(struct r5conf *conf, sector_t sector,
663 int previous, int noblock, int noquiesce)
665 struct stripe_head *sh;
666 int hash = stripe_hash_locks_hash(sector);
668 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
670 spin_lock_irq(conf->hash_locks + hash);
673 wait_event_lock_irq(conf->wait_for_quiescent,
674 conf->quiesce == 0 || noquiesce,
675 *(conf->hash_locks + hash));
676 sh = __find_stripe(conf, sector, conf->generation - previous);
678 if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
679 sh = get_free_stripe(conf, hash);
680 if (!sh && !test_bit(R5_DID_ALLOC,
682 set_bit(R5_ALLOC_MORE,
685 if (noblock && sh == NULL)
688 set_bit(R5_INACTIVE_BLOCKED,
690 wait_event_exclusive_cmd(
691 conf->wait_for_stripe[hash],
692 !list_empty(conf->inactive_list + hash) &&
693 (atomic_read(&conf->active_stripes)
694 < (conf->max_nr_stripes * 3 / 4)
695 || !test_bit(R5_INACTIVE_BLOCKED,
696 &conf->cache_state)),
697 spin_unlock_irq(conf->hash_locks + hash),
698 spin_lock_irq(conf->hash_locks + hash));
699 clear_bit(R5_INACTIVE_BLOCKED,
702 init_stripe(sh, sector, previous);
703 atomic_inc(&sh->count);
705 } else if (!atomic_inc_not_zero(&sh->count)) {
706 spin_lock(&conf->device_lock);
707 if (!atomic_read(&sh->count)) {
708 if (!test_bit(STRIPE_HANDLE, &sh->state))
709 atomic_inc(&conf->active_stripes);
710 BUG_ON(list_empty(&sh->lru) &&
711 !test_bit(STRIPE_EXPANDING, &sh->state));
712 list_del_init(&sh->lru);
714 sh->group->stripes_cnt--;
718 atomic_inc(&sh->count);
719 spin_unlock(&conf->device_lock);
721 } while (sh == NULL);
723 if (!list_empty(conf->inactive_list + hash))
724 wake_up(&conf->wait_for_stripe[hash]);
726 spin_unlock_irq(conf->hash_locks + hash);
730 static bool is_full_stripe_write(struct stripe_head *sh)
732 BUG_ON(sh->overwrite_disks > (sh->disks - sh->raid_conf->max_degraded));
733 return sh->overwrite_disks == (sh->disks - sh->raid_conf->max_degraded);
736 static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
740 spin_lock(&sh2->stripe_lock);
741 spin_lock_nested(&sh1->stripe_lock, 1);
743 spin_lock(&sh1->stripe_lock);
744 spin_lock_nested(&sh2->stripe_lock, 1);
748 static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
750 spin_unlock(&sh1->stripe_lock);
751 spin_unlock(&sh2->stripe_lock);
755 /* Only freshly new full stripe normal write stripe can be added to a batch list */
756 static bool stripe_can_batch(struct stripe_head *sh)
758 return test_bit(STRIPE_BATCH_READY, &sh->state) &&
759 !test_bit(STRIPE_BITMAP_PENDING, &sh->state) &&
760 is_full_stripe_write(sh);
763 /* we only do back search */
764 static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh)
766 struct stripe_head *head;
767 sector_t head_sector, tmp_sec;
771 if (!stripe_can_batch(sh))
773 /* Don't cross chunks, so stripe pd_idx/qd_idx is the same */
774 tmp_sec = sh->sector;
775 if (!sector_div(tmp_sec, conf->chunk_sectors))
777 head_sector = sh->sector - STRIPE_SECTORS;
779 hash = stripe_hash_locks_hash(head_sector);
780 spin_lock_irq(conf->hash_locks + hash);
781 head = __find_stripe(conf, head_sector, conf->generation);
782 if (head && !atomic_inc_not_zero(&head->count)) {
783 spin_lock(&conf->device_lock);
784 if (!atomic_read(&head->count)) {
785 if (!test_bit(STRIPE_HANDLE, &head->state))
786 atomic_inc(&conf->active_stripes);
787 BUG_ON(list_empty(&head->lru) &&
788 !test_bit(STRIPE_EXPANDING, &head->state));
789 list_del_init(&head->lru);
791 head->group->stripes_cnt--;
795 atomic_inc(&head->count);
796 spin_unlock(&conf->device_lock);
798 spin_unlock_irq(conf->hash_locks + hash);
802 if (!stripe_can_batch(head))
805 lock_two_stripes(head, sh);
806 /* clear_batch_ready clear the flag */
807 if (!stripe_can_batch(head) || !stripe_can_batch(sh))
814 while (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
816 if (head->dev[dd_idx].towrite->bi_rw != sh->dev[dd_idx].towrite->bi_rw)
819 if (head->batch_head) {
820 spin_lock(&head->batch_head->batch_lock);
821 /* This batch list is already running */
822 if (!stripe_can_batch(head)) {
823 spin_unlock(&head->batch_head->batch_lock);
828 * at this point, head's BATCH_READY could be cleared, but we
829 * can still add the stripe to batch list
831 list_add(&sh->batch_list, &head->batch_list);
832 spin_unlock(&head->batch_head->batch_lock);
834 sh->batch_head = head->batch_head;
836 head->batch_head = head;
837 sh->batch_head = head->batch_head;
838 spin_lock(&head->batch_lock);
839 list_add_tail(&sh->batch_list, &head->batch_list);
840 spin_unlock(&head->batch_lock);
843 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
844 if (atomic_dec_return(&conf->preread_active_stripes)
846 md_wakeup_thread(conf->mddev->thread);
848 if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
849 int seq = sh->bm_seq;
850 if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
851 sh->batch_head->bm_seq > seq)
852 seq = sh->batch_head->bm_seq;
853 set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
854 sh->batch_head->bm_seq = seq;
857 atomic_inc(&sh->count);
859 unlock_two_stripes(head, sh);
861 release_stripe(head);
864 /* Determine if 'data_offset' or 'new_data_offset' should be used
865 * in this stripe_head.
867 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
869 sector_t progress = conf->reshape_progress;
870 /* Need a memory barrier to make sure we see the value
871 * of conf->generation, or ->data_offset that was set before
872 * reshape_progress was updated.
875 if (progress == MaxSector)
877 if (sh->generation == conf->generation - 1)
879 /* We are in a reshape, and this is a new-generation stripe,
880 * so use new_data_offset.
886 raid5_end_read_request(struct bio *bi);
888 raid5_end_write_request(struct bio *bi);
890 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
892 struct r5conf *conf = sh->raid_conf;
893 int i, disks = sh->disks;
894 struct stripe_head *head_sh = sh;
898 for (i = disks; i--; ) {
900 int replace_only = 0;
901 struct bio *bi, *rbi;
902 struct md_rdev *rdev, *rrdev = NULL;
905 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
906 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
910 if (test_bit(R5_Discard, &sh->dev[i].flags))
912 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
914 else if (test_and_clear_bit(R5_WantReplace,
915 &sh->dev[i].flags)) {
920 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
924 bi = &sh->dev[i].req;
925 rbi = &sh->dev[i].rreq; /* For writing to replacement */
928 rrdev = rcu_dereference(conf->disks[i].replacement);
929 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
930 rdev = rcu_dereference(conf->disks[i].rdev);
939 /* We raced and saw duplicates */
942 if (test_bit(R5_ReadRepl, &head_sh->dev[i].flags) && rrdev)
947 if (rdev && test_bit(Faulty, &rdev->flags))
950 atomic_inc(&rdev->nr_pending);
951 if (rrdev && test_bit(Faulty, &rrdev->flags))
954 atomic_inc(&rrdev->nr_pending);
957 /* We have already checked bad blocks for reads. Now
958 * need to check for writes. We never accept write errors
959 * on the replacement, so we don't to check rrdev.
961 while ((rw & WRITE) && rdev &&
962 test_bit(WriteErrorSeen, &rdev->flags)) {
965 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
966 &first_bad, &bad_sectors);
971 set_bit(BlockedBadBlocks, &rdev->flags);
972 if (!conf->mddev->external &&
973 conf->mddev->flags) {
974 /* It is very unlikely, but we might
975 * still need to write out the
976 * bad block log - better give it
978 md_check_recovery(conf->mddev);
981 * Because md_wait_for_blocked_rdev
982 * will dec nr_pending, we must
983 * increment it first.
985 atomic_inc(&rdev->nr_pending);
986 md_wait_for_blocked_rdev(rdev, conf->mddev);
988 /* Acknowledged bad block - skip the write */
989 rdev_dec_pending(rdev, conf->mddev);
995 if (s->syncing || s->expanding || s->expanded
997 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
999 set_bit(STRIPE_IO_STARTED, &sh->state);
1002 bi->bi_bdev = rdev->bdev;
1004 bi->bi_end_io = (rw & WRITE)
1005 ? raid5_end_write_request
1006 : raid5_end_read_request;
1007 bi->bi_private = sh;
1009 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
1010 __func__, (unsigned long long)sh->sector,
1012 atomic_inc(&sh->count);
1014 atomic_inc(&head_sh->count);
1015 if (use_new_offset(conf, sh))
1016 bi->bi_iter.bi_sector = (sh->sector
1017 + rdev->new_data_offset);
1019 bi->bi_iter.bi_sector = (sh->sector
1020 + rdev->data_offset);
1021 if (test_bit(R5_ReadNoMerge, &head_sh->dev[i].flags))
1022 bi->bi_rw |= REQ_NOMERGE;
1024 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1025 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1026 sh->dev[i].vec.bv_page = sh->dev[i].page;
1028 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1029 bi->bi_io_vec[0].bv_offset = 0;
1030 bi->bi_iter.bi_size = STRIPE_SIZE;
1032 * If this is discard request, set bi_vcnt 0. We don't
1033 * want to confuse SCSI because SCSI will replace payload
1035 if (rw & REQ_DISCARD)
1038 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
1040 if (conf->mddev->gendisk)
1041 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
1042 bi, disk_devt(conf->mddev->gendisk),
1044 generic_make_request(bi);
1047 if (s->syncing || s->expanding || s->expanded
1049 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
1051 set_bit(STRIPE_IO_STARTED, &sh->state);
1054 rbi->bi_bdev = rrdev->bdev;
1056 BUG_ON(!(rw & WRITE));
1057 rbi->bi_end_io = raid5_end_write_request;
1058 rbi->bi_private = sh;
1060 pr_debug("%s: for %llu schedule op %ld on "
1061 "replacement disc %d\n",
1062 __func__, (unsigned long long)sh->sector,
1064 atomic_inc(&sh->count);
1066 atomic_inc(&head_sh->count);
1067 if (use_new_offset(conf, sh))
1068 rbi->bi_iter.bi_sector = (sh->sector
1069 + rrdev->new_data_offset);
1071 rbi->bi_iter.bi_sector = (sh->sector
1072 + rrdev->data_offset);
1073 if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
1074 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
1075 sh->dev[i].rvec.bv_page = sh->dev[i].page;
1077 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
1078 rbi->bi_io_vec[0].bv_offset = 0;
1079 rbi->bi_iter.bi_size = STRIPE_SIZE;
1081 * If this is discard request, set bi_vcnt 0. We don't
1082 * want to confuse SCSI because SCSI will replace payload
1084 if (rw & REQ_DISCARD)
1086 if (conf->mddev->gendisk)
1087 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
1088 rbi, disk_devt(conf->mddev->gendisk),
1090 generic_make_request(rbi);
1092 if (!rdev && !rrdev) {
1094 set_bit(STRIPE_DEGRADED, &sh->state);
1095 pr_debug("skip op %ld on disc %d for sector %llu\n",
1096 bi->bi_rw, i, (unsigned long long)sh->sector);
1097 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1098 set_bit(STRIPE_HANDLE, &sh->state);
1101 if (!head_sh->batch_head)
1103 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1110 static struct dma_async_tx_descriptor *
1111 async_copy_data(int frombio, struct bio *bio, struct page **page,
1112 sector_t sector, struct dma_async_tx_descriptor *tx,
1113 struct stripe_head *sh)
1116 struct bvec_iter iter;
1117 struct page *bio_page;
1119 struct async_submit_ctl submit;
1120 enum async_tx_flags flags = 0;
1122 if (bio->bi_iter.bi_sector >= sector)
1123 page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512;
1125 page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512;
1128 flags |= ASYNC_TX_FENCE;
1129 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
1131 bio_for_each_segment(bvl, bio, iter) {
1132 int len = bvl.bv_len;
1136 if (page_offset < 0) {
1137 b_offset = -page_offset;
1138 page_offset += b_offset;
1142 if (len > 0 && page_offset + len > STRIPE_SIZE)
1143 clen = STRIPE_SIZE - page_offset;
1148 b_offset += bvl.bv_offset;
1149 bio_page = bvl.bv_page;
1151 if (sh->raid_conf->skip_copy &&
1152 b_offset == 0 && page_offset == 0 &&
1153 clen == STRIPE_SIZE)
1156 tx = async_memcpy(*page, bio_page, page_offset,
1157 b_offset, clen, &submit);
1159 tx = async_memcpy(bio_page, *page, b_offset,
1160 page_offset, clen, &submit);
1162 /* chain the operations */
1163 submit.depend_tx = tx;
1165 if (clen < len) /* hit end of page */
1173 static void ops_complete_biofill(void *stripe_head_ref)
1175 struct stripe_head *sh = stripe_head_ref;
1176 struct bio_list return_bi = BIO_EMPTY_LIST;
1179 pr_debug("%s: stripe %llu\n", __func__,
1180 (unsigned long long)sh->sector);
1182 /* clear completed biofills */
1183 for (i = sh->disks; i--; ) {
1184 struct r5dev *dev = &sh->dev[i];
1186 /* acknowledge completion of a biofill operation */
1187 /* and check if we need to reply to a read request,
1188 * new R5_Wantfill requests are held off until
1189 * !STRIPE_BIOFILL_RUN
1191 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
1192 struct bio *rbi, *rbi2;
1197 while (rbi && rbi->bi_iter.bi_sector <
1198 dev->sector + STRIPE_SECTORS) {
1199 rbi2 = r5_next_bio(rbi, dev->sector);
1200 if (!raid5_dec_bi_active_stripes(rbi))
1201 bio_list_add(&return_bi, rbi);
1206 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
1208 return_io(&return_bi);
1210 set_bit(STRIPE_HANDLE, &sh->state);
1214 static void ops_run_biofill(struct stripe_head *sh)
1216 struct dma_async_tx_descriptor *tx = NULL;
1217 struct async_submit_ctl submit;
1220 BUG_ON(sh->batch_head);
1221 pr_debug("%s: stripe %llu\n", __func__,
1222 (unsigned long long)sh->sector);
1224 for (i = sh->disks; i--; ) {
1225 struct r5dev *dev = &sh->dev[i];
1226 if (test_bit(R5_Wantfill, &dev->flags)) {
1228 spin_lock_irq(&sh->stripe_lock);
1229 dev->read = rbi = dev->toread;
1231 spin_unlock_irq(&sh->stripe_lock);
1232 while (rbi && rbi->bi_iter.bi_sector <
1233 dev->sector + STRIPE_SECTORS) {
1234 tx = async_copy_data(0, rbi, &dev->page,
1235 dev->sector, tx, sh);
1236 rbi = r5_next_bio(rbi, dev->sector);
1241 atomic_inc(&sh->count);
1242 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
1243 async_trigger_callback(&submit);
1246 static void mark_target_uptodate(struct stripe_head *sh, int target)
1253 tgt = &sh->dev[target];
1254 set_bit(R5_UPTODATE, &tgt->flags);
1255 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1256 clear_bit(R5_Wantcompute, &tgt->flags);
1259 static void ops_complete_compute(void *stripe_head_ref)
1261 struct stripe_head *sh = stripe_head_ref;
1263 pr_debug("%s: stripe %llu\n", __func__,
1264 (unsigned long long)sh->sector);
1266 /* mark the computed target(s) as uptodate */
1267 mark_target_uptodate(sh, sh->ops.target);
1268 mark_target_uptodate(sh, sh->ops.target2);
1270 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
1271 if (sh->check_state == check_state_compute_run)
1272 sh->check_state = check_state_compute_result;
1273 set_bit(STRIPE_HANDLE, &sh->state);
1277 /* return a pointer to the address conversion region of the scribble buffer */
1278 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
1279 struct raid5_percpu *percpu, int i)
1283 addr = flex_array_get(percpu->scribble, i);
1284 return addr + sizeof(struct page *) * (sh->disks + 2);
1287 /* return a pointer to the address conversion region of the scribble buffer */
1288 static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
1292 addr = flex_array_get(percpu->scribble, i);
1296 static struct dma_async_tx_descriptor *
1297 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
1299 int disks = sh->disks;
1300 struct page **xor_srcs = to_addr_page(percpu, 0);
1301 int target = sh->ops.target;
1302 struct r5dev *tgt = &sh->dev[target];
1303 struct page *xor_dest = tgt->page;
1305 struct dma_async_tx_descriptor *tx;
1306 struct async_submit_ctl submit;
1309 BUG_ON(sh->batch_head);
1311 pr_debug("%s: stripe %llu block: %d\n",
1312 __func__, (unsigned long long)sh->sector, target);
1313 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1315 for (i = disks; i--; )
1317 xor_srcs[count++] = sh->dev[i].page;
1319 atomic_inc(&sh->count);
1321 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
1322 ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));
1323 if (unlikely(count == 1))
1324 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1326 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1331 /* set_syndrome_sources - populate source buffers for gen_syndrome
1332 * @srcs - (struct page *) array of size sh->disks
1333 * @sh - stripe_head to parse
1335 * Populates srcs in proper layout order for the stripe and returns the
1336 * 'count' of sources to be used in a call to async_gen_syndrome. The P
1337 * destination buffer is recorded in srcs[count] and the Q destination
1338 * is recorded in srcs[count+1]].
1340 static int set_syndrome_sources(struct page **srcs,
1341 struct stripe_head *sh,
1344 int disks = sh->disks;
1345 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1346 int d0_idx = raid6_d0(sh);
1350 for (i = 0; i < disks; i++)
1356 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1357 struct r5dev *dev = &sh->dev[i];
1359 if (i == sh->qd_idx || i == sh->pd_idx ||
1360 (srctype == SYNDROME_SRC_ALL) ||
1361 (srctype == SYNDROME_SRC_WANT_DRAIN &&
1362 test_bit(R5_Wantdrain, &dev->flags)) ||
1363 (srctype == SYNDROME_SRC_WRITTEN &&
1365 srcs[slot] = sh->dev[i].page;
1366 i = raid6_next_disk(i, disks);
1367 } while (i != d0_idx);
1369 return syndrome_disks;
1372 static struct dma_async_tx_descriptor *
1373 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
1375 int disks = sh->disks;
1376 struct page **blocks = to_addr_page(percpu, 0);
1378 int qd_idx = sh->qd_idx;
1379 struct dma_async_tx_descriptor *tx;
1380 struct async_submit_ctl submit;
1386 BUG_ON(sh->batch_head);
1387 if (sh->ops.target < 0)
1388 target = sh->ops.target2;
1389 else if (sh->ops.target2 < 0)
1390 target = sh->ops.target;
1392 /* we should only have one valid target */
1395 pr_debug("%s: stripe %llu block: %d\n",
1396 __func__, (unsigned long long)sh->sector, target);
1398 tgt = &sh->dev[target];
1399 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1402 atomic_inc(&sh->count);
1404 if (target == qd_idx) {
1405 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1406 blocks[count] = NULL; /* regenerating p is not necessary */
1407 BUG_ON(blocks[count+1] != dest); /* q should already be set */
1408 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1409 ops_complete_compute, sh,
1410 to_addr_conv(sh, percpu, 0));
1411 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1413 /* Compute any data- or p-drive using XOR */
1415 for (i = disks; i-- ; ) {
1416 if (i == target || i == qd_idx)
1418 blocks[count++] = sh->dev[i].page;
1421 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1422 NULL, ops_complete_compute, sh,
1423 to_addr_conv(sh, percpu, 0));
1424 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1430 static struct dma_async_tx_descriptor *
1431 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1433 int i, count, disks = sh->disks;
1434 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1435 int d0_idx = raid6_d0(sh);
1436 int faila = -1, failb = -1;
1437 int target = sh->ops.target;
1438 int target2 = sh->ops.target2;
1439 struct r5dev *tgt = &sh->dev[target];
1440 struct r5dev *tgt2 = &sh->dev[target2];
1441 struct dma_async_tx_descriptor *tx;
1442 struct page **blocks = to_addr_page(percpu, 0);
1443 struct async_submit_ctl submit;
1445 BUG_ON(sh->batch_head);
1446 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1447 __func__, (unsigned long long)sh->sector, target, target2);
1448 BUG_ON(target < 0 || target2 < 0);
1449 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1450 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1452 /* we need to open-code set_syndrome_sources to handle the
1453 * slot number conversion for 'faila' and 'failb'
1455 for (i = 0; i < disks ; i++)
1460 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1462 blocks[slot] = sh->dev[i].page;
1468 i = raid6_next_disk(i, disks);
1469 } while (i != d0_idx);
1471 BUG_ON(faila == failb);
1474 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1475 __func__, (unsigned long long)sh->sector, faila, failb);
1477 atomic_inc(&sh->count);
1479 if (failb == syndrome_disks+1) {
1480 /* Q disk is one of the missing disks */
1481 if (faila == syndrome_disks) {
1482 /* Missing P+Q, just recompute */
1483 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1484 ops_complete_compute, sh,
1485 to_addr_conv(sh, percpu, 0));
1486 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
1487 STRIPE_SIZE, &submit);
1491 int qd_idx = sh->qd_idx;
1493 /* Missing D+Q: recompute D from P, then recompute Q */
1494 if (target == qd_idx)
1495 data_target = target2;
1497 data_target = target;
1500 for (i = disks; i-- ; ) {
1501 if (i == data_target || i == qd_idx)
1503 blocks[count++] = sh->dev[i].page;
1505 dest = sh->dev[data_target].page;
1506 init_async_submit(&submit,
1507 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1509 to_addr_conv(sh, percpu, 0));
1510 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1513 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_ALL);
1514 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1515 ops_complete_compute, sh,
1516 to_addr_conv(sh, percpu, 0));
1517 return async_gen_syndrome(blocks, 0, count+2,
1518 STRIPE_SIZE, &submit);
1521 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1522 ops_complete_compute, sh,
1523 to_addr_conv(sh, percpu, 0));
1524 if (failb == syndrome_disks) {
1525 /* We're missing D+P. */
1526 return async_raid6_datap_recov(syndrome_disks+2,
1530 /* We're missing D+D. */
1531 return async_raid6_2data_recov(syndrome_disks+2,
1532 STRIPE_SIZE, faila, failb,
1538 static void ops_complete_prexor(void *stripe_head_ref)
1540 struct stripe_head *sh = stripe_head_ref;
1542 pr_debug("%s: stripe %llu\n", __func__,
1543 (unsigned long long)sh->sector);
1546 static struct dma_async_tx_descriptor *
1547 ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu,
1548 struct dma_async_tx_descriptor *tx)
1550 int disks = sh->disks;
1551 struct page **xor_srcs = to_addr_page(percpu, 0);
1552 int count = 0, pd_idx = sh->pd_idx, i;
1553 struct async_submit_ctl submit;
1555 /* existing parity data subtracted */
1556 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1558 BUG_ON(sh->batch_head);
1559 pr_debug("%s: stripe %llu\n", __func__,
1560 (unsigned long long)sh->sector);
1562 for (i = disks; i--; ) {
1563 struct r5dev *dev = &sh->dev[i];
1564 /* Only process blocks that are known to be uptodate */
1565 if (test_bit(R5_Wantdrain, &dev->flags))
1566 xor_srcs[count++] = dev->page;
1569 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1570 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1571 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1576 static struct dma_async_tx_descriptor *
1577 ops_run_prexor6(struct stripe_head *sh, struct raid5_percpu *percpu,
1578 struct dma_async_tx_descriptor *tx)
1580 struct page **blocks = to_addr_page(percpu, 0);
1582 struct async_submit_ctl submit;
1584 pr_debug("%s: stripe %llu\n", __func__,
1585 (unsigned long long)sh->sector);
1587 count = set_syndrome_sources(blocks, sh, SYNDROME_SRC_WANT_DRAIN);
1589 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_PQ_XOR_DST, tx,
1590 ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
1591 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1596 static struct dma_async_tx_descriptor *
1597 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1599 int disks = sh->disks;
1601 struct stripe_head *head_sh = sh;
1603 pr_debug("%s: stripe %llu\n", __func__,
1604 (unsigned long long)sh->sector);
1606 for (i = disks; i--; ) {
1611 if (test_and_clear_bit(R5_Wantdrain, &head_sh->dev[i].flags)) {
1616 spin_lock_irq(&sh->stripe_lock);
1617 chosen = dev->towrite;
1618 dev->towrite = NULL;
1619 sh->overwrite_disks = 0;
1620 BUG_ON(dev->written);
1621 wbi = dev->written = chosen;
1622 spin_unlock_irq(&sh->stripe_lock);
1623 WARN_ON(dev->page != dev->orig_page);
1625 while (wbi && wbi->bi_iter.bi_sector <
1626 dev->sector + STRIPE_SECTORS) {
1627 if (wbi->bi_rw & REQ_FUA)
1628 set_bit(R5_WantFUA, &dev->flags);
1629 if (wbi->bi_rw & REQ_SYNC)
1630 set_bit(R5_SyncIO, &dev->flags);
1631 if (wbi->bi_rw & REQ_DISCARD)
1632 set_bit(R5_Discard, &dev->flags);
1634 tx = async_copy_data(1, wbi, &dev->page,
1635 dev->sector, tx, sh);
1636 if (dev->page != dev->orig_page) {
1637 set_bit(R5_SkipCopy, &dev->flags);
1638 clear_bit(R5_UPTODATE, &dev->flags);
1639 clear_bit(R5_OVERWRITE, &dev->flags);
1642 wbi = r5_next_bio(wbi, dev->sector);
1645 if (head_sh->batch_head) {
1646 sh = list_first_entry(&sh->batch_list,
1659 static void ops_complete_reconstruct(void *stripe_head_ref)
1661 struct stripe_head *sh = stripe_head_ref;
1662 int disks = sh->disks;
1663 int pd_idx = sh->pd_idx;
1664 int qd_idx = sh->qd_idx;
1666 bool fua = false, sync = false, discard = false;
1668 pr_debug("%s: stripe %llu\n", __func__,
1669 (unsigned long long)sh->sector);
1671 for (i = disks; i--; ) {
1672 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1673 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
1674 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
1677 for (i = disks; i--; ) {
1678 struct r5dev *dev = &sh->dev[i];
1680 if (dev->written || i == pd_idx || i == qd_idx) {
1681 if (!discard && !test_bit(R5_SkipCopy, &dev->flags))
1682 set_bit(R5_UPTODATE, &dev->flags);
1684 set_bit(R5_WantFUA, &dev->flags);
1686 set_bit(R5_SyncIO, &dev->flags);
1690 if (sh->reconstruct_state == reconstruct_state_drain_run)
1691 sh->reconstruct_state = reconstruct_state_drain_result;
1692 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1693 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1695 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1696 sh->reconstruct_state = reconstruct_state_result;
1699 set_bit(STRIPE_HANDLE, &sh->state);
1704 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1705 struct dma_async_tx_descriptor *tx)
1707 int disks = sh->disks;
1708 struct page **xor_srcs;
1709 struct async_submit_ctl submit;
1710 int count, pd_idx = sh->pd_idx, i;
1711 struct page *xor_dest;
1713 unsigned long flags;
1715 struct stripe_head *head_sh = sh;
1718 pr_debug("%s: stripe %llu\n", __func__,
1719 (unsigned long long)sh->sector);
1721 for (i = 0; i < sh->disks; i++) {
1724 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1727 if (i >= sh->disks) {
1728 atomic_inc(&sh->count);
1729 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1730 ops_complete_reconstruct(sh);
1735 xor_srcs = to_addr_page(percpu, j);
1736 /* check if prexor is active which means only process blocks
1737 * that are part of a read-modify-write (written)
1739 if (head_sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1741 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1742 for (i = disks; i--; ) {
1743 struct r5dev *dev = &sh->dev[i];
1744 if (head_sh->dev[i].written)
1745 xor_srcs[count++] = dev->page;
1748 xor_dest = sh->dev[pd_idx].page;
1749 for (i = disks; i--; ) {
1750 struct r5dev *dev = &sh->dev[i];
1752 xor_srcs[count++] = dev->page;
1756 /* 1/ if we prexor'd then the dest is reused as a source
1757 * 2/ if we did not prexor then we are redoing the parity
1758 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1759 * for the synchronous xor case
1761 last_stripe = !head_sh->batch_head ||
1762 list_first_entry(&sh->batch_list,
1763 struct stripe_head, batch_list) == head_sh;
1765 flags = ASYNC_TX_ACK |
1766 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1768 atomic_inc(&head_sh->count);
1769 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh,
1770 to_addr_conv(sh, percpu, j));
1772 flags = prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST;
1773 init_async_submit(&submit, flags, tx, NULL, NULL,
1774 to_addr_conv(sh, percpu, j));
1777 if (unlikely(count == 1))
1778 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1780 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1783 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1790 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1791 struct dma_async_tx_descriptor *tx)
1793 struct async_submit_ctl submit;
1794 struct page **blocks;
1795 int count, i, j = 0;
1796 struct stripe_head *head_sh = sh;
1799 unsigned long txflags;
1801 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1803 for (i = 0; i < sh->disks; i++) {
1804 if (sh->pd_idx == i || sh->qd_idx == i)
1806 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1809 if (i >= sh->disks) {
1810 atomic_inc(&sh->count);
1811 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1812 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1813 ops_complete_reconstruct(sh);
1818 blocks = to_addr_page(percpu, j);
1820 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1821 synflags = SYNDROME_SRC_WRITTEN;
1822 txflags = ASYNC_TX_ACK | ASYNC_TX_PQ_XOR_DST;
1824 synflags = SYNDROME_SRC_ALL;
1825 txflags = ASYNC_TX_ACK;
1828 count = set_syndrome_sources(blocks, sh, synflags);
1829 last_stripe = !head_sh->batch_head ||
1830 list_first_entry(&sh->batch_list,
1831 struct stripe_head, batch_list) == head_sh;
1834 atomic_inc(&head_sh->count);
1835 init_async_submit(&submit, txflags, tx, ops_complete_reconstruct,
1836 head_sh, to_addr_conv(sh, percpu, j));
1838 init_async_submit(&submit, 0, tx, NULL, NULL,
1839 to_addr_conv(sh, percpu, j));
1840 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1843 sh = list_first_entry(&sh->batch_list, struct stripe_head,
1849 static void ops_complete_check(void *stripe_head_ref)
1851 struct stripe_head *sh = stripe_head_ref;
1853 pr_debug("%s: stripe %llu\n", __func__,
1854 (unsigned long long)sh->sector);
1856 sh->check_state = check_state_check_result;
1857 set_bit(STRIPE_HANDLE, &sh->state);
1861 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1863 int disks = sh->disks;
1864 int pd_idx = sh->pd_idx;
1865 int qd_idx = sh->qd_idx;
1866 struct page *xor_dest;
1867 struct page **xor_srcs = to_addr_page(percpu, 0);
1868 struct dma_async_tx_descriptor *tx;
1869 struct async_submit_ctl submit;
1873 pr_debug("%s: stripe %llu\n", __func__,
1874 (unsigned long long)sh->sector);
1876 BUG_ON(sh->batch_head);
1878 xor_dest = sh->dev[pd_idx].page;
1879 xor_srcs[count++] = xor_dest;
1880 for (i = disks; i--; ) {
1881 if (i == pd_idx || i == qd_idx)
1883 xor_srcs[count++] = sh->dev[i].page;
1886 init_async_submit(&submit, 0, NULL, NULL, NULL,
1887 to_addr_conv(sh, percpu, 0));
1888 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1889 &sh->ops.zero_sum_result, &submit);
1891 atomic_inc(&sh->count);
1892 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1893 tx = async_trigger_callback(&submit);
1896 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1898 struct page **srcs = to_addr_page(percpu, 0);
1899 struct async_submit_ctl submit;
1902 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1903 (unsigned long long)sh->sector, checkp);
1905 BUG_ON(sh->batch_head);
1906 count = set_syndrome_sources(srcs, sh, SYNDROME_SRC_ALL);
1910 atomic_inc(&sh->count);
1911 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1912 sh, to_addr_conv(sh, percpu, 0));
1913 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1914 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1917 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1919 int overlap_clear = 0, i, disks = sh->disks;
1920 struct dma_async_tx_descriptor *tx = NULL;
1921 struct r5conf *conf = sh->raid_conf;
1922 int level = conf->level;
1923 struct raid5_percpu *percpu;
1927 percpu = per_cpu_ptr(conf->percpu, cpu);
1928 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1929 ops_run_biofill(sh);
1933 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1935 tx = ops_run_compute5(sh, percpu);
1937 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1938 tx = ops_run_compute6_1(sh, percpu);
1940 tx = ops_run_compute6_2(sh, percpu);
1942 /* terminate the chain if reconstruct is not set to be run */
1943 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1947 if (test_bit(STRIPE_OP_PREXOR, &ops_request)) {
1949 tx = ops_run_prexor5(sh, percpu, tx);
1951 tx = ops_run_prexor6(sh, percpu, tx);
1954 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1955 tx = ops_run_biodrain(sh, tx);
1959 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1961 ops_run_reconstruct5(sh, percpu, tx);
1963 ops_run_reconstruct6(sh, percpu, tx);
1966 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1967 if (sh->check_state == check_state_run)
1968 ops_run_check_p(sh, percpu);
1969 else if (sh->check_state == check_state_run_q)
1970 ops_run_check_pq(sh, percpu, 0);
1971 else if (sh->check_state == check_state_run_pq)
1972 ops_run_check_pq(sh, percpu, 1);
1977 if (overlap_clear && !sh->batch_head)
1978 for (i = disks; i--; ) {
1979 struct r5dev *dev = &sh->dev[i];
1980 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1981 wake_up(&sh->raid_conf->wait_for_overlap);
1986 static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp)
1988 struct stripe_head *sh;
1990 sh = kmem_cache_zalloc(sc, gfp);
1992 spin_lock_init(&sh->stripe_lock);
1993 spin_lock_init(&sh->batch_lock);
1994 INIT_LIST_HEAD(&sh->batch_list);
1995 INIT_LIST_HEAD(&sh->lru);
1996 atomic_set(&sh->count, 1);
2000 static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
2002 struct stripe_head *sh;
2004 sh = alloc_stripe(conf->slab_cache, gfp);
2008 sh->raid_conf = conf;
2010 if (grow_buffers(sh, gfp)) {
2012 kmem_cache_free(conf->slab_cache, sh);
2015 sh->hash_lock_index =
2016 conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
2017 /* we just created an active stripe so... */
2018 atomic_inc(&conf->active_stripes);
2021 conf->max_nr_stripes++;
2025 static int grow_stripes(struct r5conf *conf, int num)
2027 struct kmem_cache *sc;
2028 int devs = max(conf->raid_disks, conf->previous_raid_disks);
2030 if (conf->mddev->gendisk)
2031 sprintf(conf->cache_name[0],
2032 "raid%d-%s", conf->level, mdname(conf->mddev));
2034 sprintf(conf->cache_name[0],
2035 "raid%d-%p", conf->level, conf->mddev);
2036 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
2038 conf->active_name = 0;
2039 sc = kmem_cache_create(conf->cache_name[conf->active_name],
2040 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
2044 conf->slab_cache = sc;
2045 conf->pool_size = devs;
2047 if (!grow_one_stripe(conf, GFP_KERNEL))
2054 * scribble_len - return the required size of the scribble region
2055 * @num - total number of disks in the array
2057 * The size must be enough to contain:
2058 * 1/ a struct page pointer for each device in the array +2
2059 * 2/ room to convert each entry in (1) to its corresponding dma
2060 * (dma_map_page()) or page (page_address()) address.
2062 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
2063 * calculate over all devices (not just the data blocks), using zeros in place
2064 * of the P and Q blocks.
2066 static struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags)
2068 struct flex_array *ret;
2071 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
2072 ret = flex_array_alloc(len, cnt, flags);
2075 /* always prealloc all elements, so no locking is required */
2076 if (flex_array_prealloc(ret, 0, cnt, flags)) {
2077 flex_array_free(ret);
2083 static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
2088 mddev_suspend(conf->mddev);
2090 for_each_present_cpu(cpu) {
2091 struct raid5_percpu *percpu;
2092 struct flex_array *scribble;
2094 percpu = per_cpu_ptr(conf->percpu, cpu);
2095 scribble = scribble_alloc(new_disks,
2096 new_sectors / STRIPE_SECTORS,
2100 flex_array_free(percpu->scribble);
2101 percpu->scribble = scribble;
2108 mddev_resume(conf->mddev);
2112 static int resize_stripes(struct r5conf *conf, int newsize)
2114 /* Make all the stripes able to hold 'newsize' devices.
2115 * New slots in each stripe get 'page' set to a new page.
2117 * This happens in stages:
2118 * 1/ create a new kmem_cache and allocate the required number of
2120 * 2/ gather all the old stripe_heads and transfer the pages across
2121 * to the new stripe_heads. This will have the side effect of
2122 * freezing the array as once all stripe_heads have been collected,
2123 * no IO will be possible. Old stripe heads are freed once their
2124 * pages have been transferred over, and the old kmem_cache is
2125 * freed when all stripes are done.
2126 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
2127 * we simple return a failre status - no need to clean anything up.
2128 * 4/ allocate new pages for the new slots in the new stripe_heads.
2129 * If this fails, we don't bother trying the shrink the
2130 * stripe_heads down again, we just leave them as they are.
2131 * As each stripe_head is processed the new one is released into
2134 * Once step2 is started, we cannot afford to wait for a write,
2135 * so we use GFP_NOIO allocations.
2137 struct stripe_head *osh, *nsh;
2138 LIST_HEAD(newstripes);
2139 struct disk_info *ndisks;
2141 struct kmem_cache *sc;
2145 if (newsize <= conf->pool_size)
2146 return 0; /* never bother to shrink */
2148 err = md_allow_write(conf->mddev);
2153 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
2154 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
2159 /* Need to ensure auto-resizing doesn't interfere */
2160 mutex_lock(&conf->cache_size_mutex);
2162 for (i = conf->max_nr_stripes; i; i--) {
2163 nsh = alloc_stripe(sc, GFP_KERNEL);
2167 nsh->raid_conf = conf;
2168 list_add(&nsh->lru, &newstripes);
2171 /* didn't get enough, give up */
2172 while (!list_empty(&newstripes)) {
2173 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2174 list_del(&nsh->lru);
2175 kmem_cache_free(sc, nsh);
2177 kmem_cache_destroy(sc);
2178 mutex_unlock(&conf->cache_size_mutex);
2181 /* Step 2 - Must use GFP_NOIO now.
2182 * OK, we have enough stripes, start collecting inactive
2183 * stripes and copying them over
2187 list_for_each_entry(nsh, &newstripes, lru) {
2188 lock_device_hash_lock(conf, hash);
2189 wait_event_exclusive_cmd(conf->wait_for_stripe[hash],
2190 !list_empty(conf->inactive_list + hash),
2191 unlock_device_hash_lock(conf, hash),
2192 lock_device_hash_lock(conf, hash));
2193 osh = get_free_stripe(conf, hash);
2194 unlock_device_hash_lock(conf, hash);
2196 for(i=0; i<conf->pool_size; i++) {
2197 nsh->dev[i].page = osh->dev[i].page;
2198 nsh->dev[i].orig_page = osh->dev[i].page;
2200 nsh->hash_lock_index = hash;
2201 kmem_cache_free(conf->slab_cache, osh);
2203 if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +
2204 !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
2209 kmem_cache_destroy(conf->slab_cache);
2212 * At this point, we are holding all the stripes so the array
2213 * is completely stalled, so now is a good time to resize
2214 * conf->disks and the scribble region
2216 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
2218 for (i=0; i<conf->raid_disks; i++)
2219 ndisks[i] = conf->disks[i];
2221 conf->disks = ndisks;
2225 mutex_unlock(&conf->cache_size_mutex);
2226 /* Step 4, return new stripes to service */
2227 while(!list_empty(&newstripes)) {
2228 nsh = list_entry(newstripes.next, struct stripe_head, lru);
2229 list_del_init(&nsh->lru);
2231 for (i=conf->raid_disks; i < newsize; i++)
2232 if (nsh->dev[i].page == NULL) {
2233 struct page *p = alloc_page(GFP_NOIO);
2234 nsh->dev[i].page = p;
2235 nsh->dev[i].orig_page = p;
2239 release_stripe(nsh);
2241 /* critical section pass, GFP_NOIO no longer needed */
2243 conf->slab_cache = sc;
2244 conf->active_name = 1-conf->active_name;
2246 conf->pool_size = newsize;
2250 static int drop_one_stripe(struct r5conf *conf)
2252 struct stripe_head *sh;
2253 int hash = (conf->max_nr_stripes - 1) & STRIPE_HASH_LOCKS_MASK;
2255 spin_lock_irq(conf->hash_locks + hash);
2256 sh = get_free_stripe(conf, hash);
2257 spin_unlock_irq(conf->hash_locks + hash);
2260 BUG_ON(atomic_read(&sh->count));
2262 kmem_cache_free(conf->slab_cache, sh);
2263 atomic_dec(&conf->active_stripes);
2264 conf->max_nr_stripes--;
2268 static void shrink_stripes(struct r5conf *conf)
2270 while (conf->max_nr_stripes &&
2271 drop_one_stripe(conf))
2274 kmem_cache_destroy(conf->slab_cache);
2275 conf->slab_cache = NULL;
2278 static void raid5_end_read_request(struct bio * bi)
2280 struct stripe_head *sh = bi->bi_private;
2281 struct r5conf *conf = sh->raid_conf;
2282 int disks = sh->disks, i;
2283 char b[BDEVNAME_SIZE];
2284 struct md_rdev *rdev = NULL;
2287 for (i=0 ; i<disks; i++)
2288 if (bi == &sh->dev[i].req)
2291 pr_debug("end_read_request %llu/%d, count: %d, error %d.\n",
2292 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2298 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2299 /* If replacement finished while this request was outstanding,
2300 * 'replacement' might be NULL already.
2301 * In that case it moved down to 'rdev'.
2302 * rdev is not removed until all requests are finished.
2304 rdev = conf->disks[i].replacement;
2306 rdev = conf->disks[i].rdev;
2308 if (use_new_offset(conf, sh))
2309 s = sh->sector + rdev->new_data_offset;
2311 s = sh->sector + rdev->data_offset;
2312 if (!bi->bi_error) {
2313 set_bit(R5_UPTODATE, &sh->dev[i].flags);
2314 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2315 /* Note that this cannot happen on a
2316 * replacement device. We just fail those on
2321 "md/raid:%s: read error corrected"
2322 " (%lu sectors at %llu on %s)\n",
2323 mdname(conf->mddev), STRIPE_SECTORS,
2324 (unsigned long long)s,
2325 bdevname(rdev->bdev, b));
2326 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2327 clear_bit(R5_ReadError, &sh->dev[i].flags);
2328 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2329 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2330 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2332 if (atomic_read(&rdev->read_errors))
2333 atomic_set(&rdev->read_errors, 0);
2335 const char *bdn = bdevname(rdev->bdev, b);
2339 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
2340 atomic_inc(&rdev->read_errors);
2341 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
2344 "md/raid:%s: read error on replacement device "
2345 "(sector %llu on %s).\n",
2346 mdname(conf->mddev),
2347 (unsigned long long)s,
2349 else if (conf->mddev->degraded >= conf->max_degraded) {
2353 "md/raid:%s: read error not correctable "
2354 "(sector %llu on %s).\n",
2355 mdname(conf->mddev),
2356 (unsigned long long)s,
2358 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
2363 "md/raid:%s: read error NOT corrected!! "
2364 "(sector %llu on %s).\n",
2365 mdname(conf->mddev),
2366 (unsigned long long)s,
2368 } else if (atomic_read(&rdev->read_errors)
2369 > conf->max_nr_stripes)
2371 "md/raid:%s: Too many read errors, failing device %s.\n",
2372 mdname(conf->mddev), bdn);
2375 if (set_bad && test_bit(In_sync, &rdev->flags)
2376 && !test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
2379 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
2380 set_bit(R5_ReadError, &sh->dev[i].flags);
2381 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2383 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
2385 clear_bit(R5_ReadError, &sh->dev[i].flags);
2386 clear_bit(R5_ReWrite, &sh->dev[i].flags);
2388 && test_bit(In_sync, &rdev->flags)
2389 && rdev_set_badblocks(
2390 rdev, sh->sector, STRIPE_SECTORS, 0)))
2391 md_error(conf->mddev, rdev);
2394 rdev_dec_pending(rdev, conf->mddev);
2395 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2396 set_bit(STRIPE_HANDLE, &sh->state);
2400 static void raid5_end_write_request(struct bio *bi)
2402 struct stripe_head *sh = bi->bi_private;
2403 struct r5conf *conf = sh->raid_conf;
2404 int disks = sh->disks, i;
2405 struct md_rdev *uninitialized_var(rdev);
2408 int replacement = 0;
2410 for (i = 0 ; i < disks; i++) {
2411 if (bi == &sh->dev[i].req) {
2412 rdev = conf->disks[i].rdev;
2415 if (bi == &sh->dev[i].rreq) {
2416 rdev = conf->disks[i].replacement;
2420 /* rdev was removed and 'replacement'
2421 * replaced it. rdev is not removed
2422 * until all requests are finished.
2424 rdev = conf->disks[i].rdev;
2428 pr_debug("end_write_request %llu/%d, count %d, error: %d.\n",
2429 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
2438 md_error(conf->mddev, rdev);
2439 else if (is_badblock(rdev, sh->sector,
2441 &first_bad, &bad_sectors))
2442 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
2445 set_bit(STRIPE_DEGRADED, &sh->state);
2446 set_bit(WriteErrorSeen, &rdev->flags);
2447 set_bit(R5_WriteError, &sh->dev[i].flags);
2448 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2449 set_bit(MD_RECOVERY_NEEDED,
2450 &rdev->mddev->recovery);
2451 } else if (is_badblock(rdev, sh->sector,
2453 &first_bad, &bad_sectors)) {
2454 set_bit(R5_MadeGood, &sh->dev[i].flags);
2455 if (test_bit(R5_ReadError, &sh->dev[i].flags))
2456 /* That was a successful write so make
2457 * sure it looks like we already did
2460 set_bit(R5_ReWrite, &sh->dev[i].flags);
2463 rdev_dec_pending(rdev, conf->mddev);
2465 if (sh->batch_head && bi->bi_error && !replacement)
2466 set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state);
2468 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
2469 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2470 set_bit(STRIPE_HANDLE, &sh->state);
2473 if (sh->batch_head && sh != sh->batch_head)
2474 release_stripe(sh->batch_head);
2477 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
2479 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
2481 struct r5dev *dev = &sh->dev[i];
2483 bio_init(&dev->req);
2484 dev->req.bi_io_vec = &dev->vec;
2485 dev->req.bi_max_vecs = 1;
2486 dev->req.bi_private = sh;
2488 bio_init(&dev->rreq);
2489 dev->rreq.bi_io_vec = &dev->rvec;
2490 dev->rreq.bi_max_vecs = 1;
2491 dev->rreq.bi_private = sh;
2494 dev->sector = compute_blocknr(sh, i, previous);
2497 static void error(struct mddev *mddev, struct md_rdev *rdev)
2499 char b[BDEVNAME_SIZE];
2500 struct r5conf *conf = mddev->private;
2501 unsigned long flags;
2502 pr_debug("raid456: error called\n");
2504 spin_lock_irqsave(&conf->device_lock, flags);
2505 clear_bit(In_sync, &rdev->flags);
2506 mddev->degraded = calc_degraded(conf);
2507 spin_unlock_irqrestore(&conf->device_lock, flags);
2508 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2510 set_bit(Blocked, &rdev->flags);
2511 set_bit(Faulty, &rdev->flags);
2512 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2513 set_bit(MD_CHANGE_PENDING, &mddev->flags);
2515 "md/raid:%s: Disk failure on %s, disabling device.\n"
2516 "md/raid:%s: Operation continuing on %d devices.\n",
2518 bdevname(rdev->bdev, b),
2520 conf->raid_disks - mddev->degraded);
2524 * Input: a 'big' sector number,
2525 * Output: index of the data and parity disk, and the sector # in them.
2527 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
2528 int previous, int *dd_idx,
2529 struct stripe_head *sh)
2531 sector_t stripe, stripe2;
2532 sector_t chunk_number;
2533 unsigned int chunk_offset;
2536 sector_t new_sector;
2537 int algorithm = previous ? conf->prev_algo
2539 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2540 : conf->chunk_sectors;
2541 int raid_disks = previous ? conf->previous_raid_disks
2543 int data_disks = raid_disks - conf->max_degraded;
2545 /* First compute the information on this sector */
2548 * Compute the chunk number and the sector offset inside the chunk
2550 chunk_offset = sector_div(r_sector, sectors_per_chunk);
2551 chunk_number = r_sector;
2554 * Compute the stripe number
2556 stripe = chunk_number;
2557 *dd_idx = sector_div(stripe, data_disks);
2560 * Select the parity disk based on the user selected algorithm.
2562 pd_idx = qd_idx = -1;
2563 switch(conf->level) {
2565 pd_idx = data_disks;
2568 switch (algorithm) {
2569 case ALGORITHM_LEFT_ASYMMETRIC:
2570 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2571 if (*dd_idx >= pd_idx)
2574 case ALGORITHM_RIGHT_ASYMMETRIC:
2575 pd_idx = sector_div(stripe2, raid_disks);
2576 if (*dd_idx >= pd_idx)
2579 case ALGORITHM_LEFT_SYMMETRIC:
2580 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2581 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2583 case ALGORITHM_RIGHT_SYMMETRIC:
2584 pd_idx = sector_div(stripe2, raid_disks);
2585 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2587 case ALGORITHM_PARITY_0:
2591 case ALGORITHM_PARITY_N:
2592 pd_idx = data_disks;
2600 switch (algorithm) {
2601 case ALGORITHM_LEFT_ASYMMETRIC:
2602 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2603 qd_idx = pd_idx + 1;
2604 if (pd_idx == raid_disks-1) {
2605 (*dd_idx)++; /* Q D D D P */
2607 } else if (*dd_idx >= pd_idx)
2608 (*dd_idx) += 2; /* D D P Q D */
2610 case ALGORITHM_RIGHT_ASYMMETRIC:
2611 pd_idx = sector_div(stripe2, raid_disks);
2612 qd_idx = pd_idx + 1;
2613 if (pd_idx == raid_disks-1) {
2614 (*dd_idx)++; /* Q D D D P */
2616 } else if (*dd_idx >= pd_idx)
2617 (*dd_idx) += 2; /* D D P Q D */
2619 case ALGORITHM_LEFT_SYMMETRIC:
2620 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2621 qd_idx = (pd_idx + 1) % raid_disks;
2622 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2624 case ALGORITHM_RIGHT_SYMMETRIC:
2625 pd_idx = sector_div(stripe2, raid_disks);
2626 qd_idx = (pd_idx + 1) % raid_disks;
2627 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2630 case ALGORITHM_PARITY_0:
2635 case ALGORITHM_PARITY_N:
2636 pd_idx = data_disks;
2637 qd_idx = data_disks + 1;
2640 case ALGORITHM_ROTATING_ZERO_RESTART:
2641 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2642 * of blocks for computing Q is different.
2644 pd_idx = sector_div(stripe2, raid_disks);
2645 qd_idx = pd_idx + 1;
2646 if (pd_idx == raid_disks-1) {
2647 (*dd_idx)++; /* Q D D D P */
2649 } else if (*dd_idx >= pd_idx)
2650 (*dd_idx) += 2; /* D D P Q D */
2654 case ALGORITHM_ROTATING_N_RESTART:
2655 /* Same a left_asymmetric, by first stripe is
2656 * D D D P Q rather than
2660 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2661 qd_idx = pd_idx + 1;
2662 if (pd_idx == raid_disks-1) {
2663 (*dd_idx)++; /* Q D D D P */
2665 } else if (*dd_idx >= pd_idx)
2666 (*dd_idx) += 2; /* D D P Q D */
2670 case ALGORITHM_ROTATING_N_CONTINUE:
2671 /* Same as left_symmetric but Q is before P */
2672 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2673 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2674 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2678 case ALGORITHM_LEFT_ASYMMETRIC_6:
2679 /* RAID5 left_asymmetric, with Q on last device */
2680 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2681 if (*dd_idx >= pd_idx)
2683 qd_idx = raid_disks - 1;
2686 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2687 pd_idx = sector_div(stripe2, raid_disks-1);
2688 if (*dd_idx >= pd_idx)
2690 qd_idx = raid_disks - 1;
2693 case ALGORITHM_LEFT_SYMMETRIC_6:
2694 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2695 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2696 qd_idx = raid_disks - 1;
2699 case ALGORITHM_RIGHT_SYMMETRIC_6:
2700 pd_idx = sector_div(stripe2, raid_disks-1);
2701 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2702 qd_idx = raid_disks - 1;
2705 case ALGORITHM_PARITY_0_6:
2708 qd_idx = raid_disks - 1;
2718 sh->pd_idx = pd_idx;
2719 sh->qd_idx = qd_idx;
2720 sh->ddf_layout = ddf_layout;
2723 * Finally, compute the new sector number
2725 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2729 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
2731 struct r5conf *conf = sh->raid_conf;
2732 int raid_disks = sh->disks;
2733 int data_disks = raid_disks - conf->max_degraded;
2734 sector_t new_sector = sh->sector, check;
2735 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2736 : conf->chunk_sectors;
2737 int algorithm = previous ? conf->prev_algo
2741 sector_t chunk_number;
2742 int dummy1, dd_idx = i;
2744 struct stripe_head sh2;
2746 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2747 stripe = new_sector;
2749 if (i == sh->pd_idx)
2751 switch(conf->level) {
2754 switch (algorithm) {
2755 case ALGORITHM_LEFT_ASYMMETRIC:
2756 case ALGORITHM_RIGHT_ASYMMETRIC:
2760 case ALGORITHM_LEFT_SYMMETRIC:
2761 case ALGORITHM_RIGHT_SYMMETRIC:
2764 i -= (sh->pd_idx + 1);
2766 case ALGORITHM_PARITY_0:
2769 case ALGORITHM_PARITY_N:
2776 if (i == sh->qd_idx)
2777 return 0; /* It is the Q disk */
2778 switch (algorithm) {
2779 case ALGORITHM_LEFT_ASYMMETRIC:
2780 case ALGORITHM_RIGHT_ASYMMETRIC:
2781 case ALGORITHM_ROTATING_ZERO_RESTART:
2782 case ALGORITHM_ROTATING_N_RESTART:
2783 if (sh->pd_idx == raid_disks-1)
2784 i--; /* Q D D D P */
2785 else if (i > sh->pd_idx)
2786 i -= 2; /* D D P Q D */
2788 case ALGORITHM_LEFT_SYMMETRIC:
2789 case ALGORITHM_RIGHT_SYMMETRIC:
2790 if (sh->pd_idx == raid_disks-1)
2791 i--; /* Q D D D P */
2796 i -= (sh->pd_idx + 2);
2799 case ALGORITHM_PARITY_0:
2802 case ALGORITHM_PARITY_N:
2804 case ALGORITHM_ROTATING_N_CONTINUE:
2805 /* Like left_symmetric, but P is before Q */
2806 if (sh->pd_idx == 0)
2807 i--; /* P D D D Q */
2812 i -= (sh->pd_idx + 1);
2815 case ALGORITHM_LEFT_ASYMMETRIC_6:
2816 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2820 case ALGORITHM_LEFT_SYMMETRIC_6:
2821 case ALGORITHM_RIGHT_SYMMETRIC_6:
2823 i += data_disks + 1;
2824 i -= (sh->pd_idx + 1);
2826 case ALGORITHM_PARITY_0_6:
2835 chunk_number = stripe * data_disks + i;
2836 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2838 check = raid5_compute_sector(conf, r_sector,
2839 previous, &dummy1, &sh2);
2840 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2841 || sh2.qd_idx != sh->qd_idx) {
2842 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2843 mdname(conf->mddev));
2850 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2851 int rcw, int expand)
2853 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx, disks = sh->disks;
2854 struct r5conf *conf = sh->raid_conf;
2855 int level = conf->level;
2859 for (i = disks; i--; ) {
2860 struct r5dev *dev = &sh->dev[i];
2863 set_bit(R5_LOCKED, &dev->flags);
2864 set_bit(R5_Wantdrain, &dev->flags);
2866 clear_bit(R5_UPTODATE, &dev->flags);
2870 /* if we are not expanding this is a proper write request, and
2871 * there will be bios with new data to be drained into the
2876 /* False alarm, nothing to do */
2878 sh->reconstruct_state = reconstruct_state_drain_run;
2879 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2881 sh->reconstruct_state = reconstruct_state_run;
2883 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2885 if (s->locked + conf->max_degraded == disks)
2886 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2887 atomic_inc(&conf->pending_full_writes);
2889 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2890 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2891 BUG_ON(level == 6 &&
2892 (!(test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags) ||
2893 test_bit(R5_Wantcompute, &sh->dev[qd_idx].flags))));
2895 for (i = disks; i--; ) {
2896 struct r5dev *dev = &sh->dev[i];
2897 if (i == pd_idx || i == qd_idx)
2901 (test_bit(R5_UPTODATE, &dev->flags) ||
2902 test_bit(R5_Wantcompute, &dev->flags))) {
2903 set_bit(R5_Wantdrain, &dev->flags);
2904 set_bit(R5_LOCKED, &dev->flags);
2905 clear_bit(R5_UPTODATE, &dev->flags);
2910 /* False alarm - nothing to do */
2912 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2913 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2914 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2915 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2918 /* keep the parity disk(s) locked while asynchronous operations
2921 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2922 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2926 int qd_idx = sh->qd_idx;
2927 struct r5dev *dev = &sh->dev[qd_idx];
2929 set_bit(R5_LOCKED, &dev->flags);
2930 clear_bit(R5_UPTODATE, &dev->flags);
2934 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2935 __func__, (unsigned long long)sh->sector,
2936 s->locked, s->ops_request);
2940 * Each stripe/dev can have one or more bion attached.
2941 * toread/towrite point to the first in a chain.
2942 * The bi_next chain must be in order.
2944 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
2945 int forwrite, int previous)
2948 struct r5conf *conf = sh->raid_conf;
2951 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2952 (unsigned long long)bi->bi_iter.bi_sector,
2953 (unsigned long long)sh->sector);
2956 * If several bio share a stripe. The bio bi_phys_segments acts as a
2957 * reference count to avoid race. The reference count should already be
2958 * increased before this function is called (for example, in
2959 * make_request()), so other bio sharing this stripe will not free the
2960 * stripe. If a stripe is owned by one stripe, the stripe lock will
2963 spin_lock_irq(&sh->stripe_lock);
2964 /* Don't allow new IO added to stripes in batch list */
2968 bip = &sh->dev[dd_idx].towrite;
2972 bip = &sh->dev[dd_idx].toread;
2973 while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
2974 if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
2976 bip = & (*bip)->bi_next;
2978 if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
2981 if (!forwrite || previous)
2982 clear_bit(STRIPE_BATCH_READY, &sh->state);
2984 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2988 raid5_inc_bi_active_stripes(bi);
2991 /* check if page is covered */
2992 sector_t sector = sh->dev[dd_idx].sector;
2993 for (bi=sh->dev[dd_idx].towrite;
2994 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2995 bi && bi->bi_iter.bi_sector <= sector;
2996 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2997 if (bio_end_sector(bi) >= sector)
2998 sector = bio_end_sector(bi);
3000 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
3001 if (!test_and_set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags))
3002 sh->overwrite_disks++;
3005 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
3006 (unsigned long long)(*bip)->bi_iter.bi_sector,
3007 (unsigned long long)sh->sector, dd_idx);
3009 if (conf->mddev->bitmap && firstwrite) {
3010 /* Cannot hold spinlock over bitmap_startwrite,
3011 * but must ensure this isn't added to a batch until
3012 * we have added to the bitmap and set bm_seq.
3013 * So set STRIPE_BITMAP_PENDING to prevent
3015 * If multiple add_stripe_bio() calls race here they
3016 * much all set STRIPE_BITMAP_PENDING. So only the first one
3017 * to complete "bitmap_startwrite" gets to set
3018 * STRIPE_BIT_DELAY. This is important as once a stripe
3019 * is added to a batch, STRIPE_BIT_DELAY cannot be changed
3022 set_bit(STRIPE_BITMAP_PENDING, &sh->state);
3023 spin_unlock_irq(&sh->stripe_lock);
3024 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
3026 spin_lock_irq(&sh->stripe_lock);
3027 clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
3028 if (!sh->batch_head) {
3029 sh->bm_seq = conf->seq_flush+1;
3030 set_bit(STRIPE_BIT_DELAY, &sh->state);
3033 spin_unlock_irq(&sh->stripe_lock);
3035 if (stripe_can_batch(sh))
3036 stripe_add_to_batch_list(conf, sh);
3040 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
3041 spin_unlock_irq(&sh->stripe_lock);
3045 static void end_reshape(struct r5conf *conf);
3047 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
3048 struct stripe_head *sh)
3050 int sectors_per_chunk =
3051 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
3053 int chunk_offset = sector_div(stripe, sectors_per_chunk);
3054 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
3056 raid5_compute_sector(conf,
3057 stripe * (disks - conf->max_degraded)
3058 *sectors_per_chunk + chunk_offset,
3064 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
3065 struct stripe_head_state *s, int disks,
3066 struct bio_list *return_bi)
3069 BUG_ON(sh->batch_head);
3070 for (i = disks; i--; ) {
3074 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
3075 struct md_rdev *rdev;
3077 rdev = rcu_dereference(conf->disks[i].rdev);
3078 if (rdev && test_bit(In_sync, &rdev->flags))
3079 atomic_inc(&rdev->nr_pending);
3084 if (!rdev_set_badblocks(
3088 md_error(conf->mddev, rdev);
3089 rdev_dec_pending(rdev, conf->mddev);
3092 spin_lock_irq(&sh->stripe_lock);
3093 /* fail all writes first */
3094 bi = sh->dev[i].towrite;
3095 sh->dev[i].towrite = NULL;
3096 sh->overwrite_disks = 0;
3097 spin_unlock_irq(&sh->stripe_lock);
3101 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3102 wake_up(&conf->wait_for_overlap);
3104 while (bi && bi->bi_iter.bi_sector <
3105 sh->dev[i].sector + STRIPE_SECTORS) {
3106 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
3108 bi->bi_error = -EIO;
3109 if (!raid5_dec_bi_active_stripes(bi)) {
3110 md_write_end(conf->mddev);
3111 bio_list_add(return_bi, bi);
3116 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3117 STRIPE_SECTORS, 0, 0);
3119 /* and fail all 'written' */
3120 bi = sh->dev[i].written;
3121 sh->dev[i].written = NULL;
3122 if (test_and_clear_bit(R5_SkipCopy, &sh->dev[i].flags)) {
3123 WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
3124 sh->dev[i].page = sh->dev[i].orig_page;
3127 if (bi) bitmap_end = 1;
3128 while (bi && bi->bi_iter.bi_sector <
3129 sh->dev[i].sector + STRIPE_SECTORS) {
3130 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
3132 bi->bi_error = -EIO;
3133 if (!raid5_dec_bi_active_stripes(bi)) {
3134 md_write_end(conf->mddev);
3135 bio_list_add(return_bi, bi);
3140 /* fail any reads if this device is non-operational and
3141 * the data has not reached the cache yet.
3143 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
3144 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
3145 test_bit(R5_ReadError, &sh->dev[i].flags))) {
3146 spin_lock_irq(&sh->stripe_lock);
3147 bi = sh->dev[i].toread;
3148 sh->dev[i].toread = NULL;
3149 spin_unlock_irq(&sh->stripe_lock);
3150 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
3151 wake_up(&conf->wait_for_overlap);
3154 while (bi && bi->bi_iter.bi_sector <
3155 sh->dev[i].sector + STRIPE_SECTORS) {
3156 struct bio *nextbi =
3157 r5_next_bio(bi, sh->dev[i].sector);
3159 bi->bi_error = -EIO;
3160 if (!raid5_dec_bi_active_stripes(bi))
3161 bio_list_add(return_bi, bi);
3166 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3167 STRIPE_SECTORS, 0, 0);
3168 /* If we were in the middle of a write the parity block might
3169 * still be locked - so just clear all R5_LOCKED flags
3171 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3176 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3177 if (atomic_dec_and_test(&conf->pending_full_writes))
3178 md_wakeup_thread(conf->mddev->thread);
3182 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
3183 struct stripe_head_state *s)
3188 BUG_ON(sh->batch_head);
3189 clear_bit(STRIPE_SYNCING, &sh->state);
3190 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3191 wake_up(&conf->wait_for_overlap);
3194 /* There is nothing more to do for sync/check/repair.
3195 * Don't even need to abort as that is handled elsewhere
3196 * if needed, and not always wanted e.g. if there is a known
3198 * For recover/replace we need to record a bad block on all
3199 * non-sync devices, or abort the recovery
3201 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
3202 /* During recovery devices cannot be removed, so
3203 * locking and refcounting of rdevs is not needed
3205 for (i = 0; i < conf->raid_disks; i++) {
3206 struct md_rdev *rdev = conf->disks[i].rdev;
3208 && !test_bit(Faulty, &rdev->flags)
3209 && !test_bit(In_sync, &rdev->flags)
3210 && !rdev_set_badblocks(rdev, sh->sector,
3213 rdev = conf->disks[i].replacement;
3215 && !test_bit(Faulty, &rdev->flags)
3216 && !test_bit(In_sync, &rdev->flags)
3217 && !rdev_set_badblocks(rdev, sh->sector,
3222 conf->recovery_disabled =
3223 conf->mddev->recovery_disabled;
3225 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
3228 static int want_replace(struct stripe_head *sh, int disk_idx)
3230 struct md_rdev *rdev;
3232 /* Doing recovery so rcu locking not required */
3233 rdev = sh->raid_conf->disks[disk_idx].replacement;
3235 && !test_bit(Faulty, &rdev->flags)
3236 && !test_bit(In_sync, &rdev->flags)
3237 && (rdev->recovery_offset <= sh->sector
3238 || rdev->mddev->recovery_cp <= sh->sector))
3244 /* fetch_block - checks the given member device to see if its data needs
3245 * to be read or computed to satisfy a request.
3247 * Returns 1 when no more member devices need to be checked, otherwise returns
3248 * 0 to tell the loop in handle_stripe_fill to continue
3251 static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,
3252 int disk_idx, int disks)
3254 struct r5dev *dev = &sh->dev[disk_idx];
3255 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
3256 &sh->dev[s->failed_num[1]] };
3260 if (test_bit(R5_LOCKED, &dev->flags) ||
3261 test_bit(R5_UPTODATE, &dev->flags))
3262 /* No point reading this as we already have it or have
3263 * decided to get it.
3268 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)))
3269 /* We need this block to directly satisfy a request */
3272 if (s->syncing || s->expanding ||
3273 (s->replacing && want_replace(sh, disk_idx)))
3274 /* When syncing, or expanding we read everything.
3275 * When replacing, we need the replaced block.
3279 if ((s->failed >= 1 && fdev[0]->toread) ||
3280 (s->failed >= 2 && fdev[1]->toread))
3281 /* If we want to read from a failed device, then
3282 * we need to actually read every other device.
3286 /* Sometimes neither read-modify-write nor reconstruct-write
3287 * cycles can work. In those cases we read every block we
3288 * can. Then the parity-update is certain to have enough to
3290 * This can only be a problem when we need to write something,
3291 * and some device has failed. If either of those tests
3292 * fail we need look no further.
3294 if (!s->failed || !s->to_write)
3297 if (test_bit(R5_Insync, &dev->flags) &&
3298 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3299 /* Pre-reads at not permitted until after short delay
3300 * to gather multiple requests. However if this
3301 * device is no Insync, the block could only be be computed
3302 * and there is no need to delay that.
3306 for (i = 0; i < s->failed && i < 2; i++) {
3307 if (fdev[i]->towrite &&
3308 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3309 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3310 /* If we have a partial write to a failed
3311 * device, then we will need to reconstruct
3312 * the content of that device, so all other
3313 * devices must be read.
3318 /* If we are forced to do a reconstruct-write, either because
3319 * the current RAID6 implementation only supports that, or
3320 * or because parity cannot be trusted and we are currently
3321 * recovering it, there is extra need to be careful.
3322 * If one of the devices that we would need to read, because
3323 * it is not being overwritten (and maybe not written at all)
3324 * is missing/faulty, then we need to read everything we can.
3326 if (sh->raid_conf->level != 6 &&
3327 sh->sector < sh->raid_conf->mddev->recovery_cp)
3328 /* reconstruct-write isn't being forced */
3330 for (i = 0; i < s->failed && i < 2; i++) {
3331 if (s->failed_num[i] != sh->pd_idx &&
3332 s->failed_num[i] != sh->qd_idx &&
3333 !test_bit(R5_UPTODATE, &fdev[i]->flags) &&
3334 !test_bit(R5_OVERWRITE, &fdev[i]->flags))
3341 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
3342 int disk_idx, int disks)
3344 struct r5dev *dev = &sh->dev[disk_idx];
3346 /* is the data in this block needed, and can we get it? */
3347 if (need_this_block(sh, s, disk_idx, disks)) {
3348 /* we would like to get this block, possibly by computing it,
3349 * otherwise read it if the backing disk is insync
3351 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
3352 BUG_ON(test_bit(R5_Wantread, &dev->flags));
3353 BUG_ON(sh->batch_head);
3354 if ((s->uptodate == disks - 1) &&
3355 (s->failed && (disk_idx == s->failed_num[0] ||
3356 disk_idx == s->failed_num[1]))) {
3357 /* have disk failed, and we're requested to fetch it;
3360 pr_debug("Computing stripe %llu block %d\n",
3361 (unsigned long long)sh->sector, disk_idx);
3362 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3363 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3364 set_bit(R5_Wantcompute, &dev->flags);
3365 sh->ops.target = disk_idx;
3366 sh->ops.target2 = -1; /* no 2nd target */
3368 /* Careful: from this point on 'uptodate' is in the eye
3369 * of raid_run_ops which services 'compute' operations
3370 * before writes. R5_Wantcompute flags a block that will
3371 * be R5_UPTODATE by the time it is needed for a
3372 * subsequent operation.
3376 } else if (s->uptodate == disks-2 && s->failed >= 2) {
3377 /* Computing 2-failure is *very* expensive; only
3378 * do it if failed >= 2
3381 for (other = disks; other--; ) {
3382 if (other == disk_idx)
3384 if (!test_bit(R5_UPTODATE,
3385 &sh->dev[other].flags))
3389 pr_debug("Computing stripe %llu blocks %d,%d\n",
3390 (unsigned long long)sh->sector,
3392 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3393 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3394 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
3395 set_bit(R5_Wantcompute, &sh->dev[other].flags);
3396 sh->ops.target = disk_idx;
3397 sh->ops.target2 = other;
3401 } else if (test_bit(R5_Insync, &dev->flags)) {
3402 set_bit(R5_LOCKED, &dev->flags);
3403 set_bit(R5_Wantread, &dev->flags);
3405 pr_debug("Reading block %d (sync=%d)\n",
3406 disk_idx, s->syncing);
3414 * handle_stripe_fill - read or compute data to satisfy pending requests.
3416 static void handle_stripe_fill(struct stripe_head *sh,
3417 struct stripe_head_state *s,
3422 /* look for blocks to read/compute, skip this if a compute
3423 * is already in flight, or if the stripe contents are in the
3424 * midst of changing due to a write
3426 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
3427 !sh->reconstruct_state)
3428 for (i = disks; i--; )
3429 if (fetch_block(sh, s, i, disks))
3431 set_bit(STRIPE_HANDLE, &sh->state);
3434 static void break_stripe_batch_list(struct stripe_head *head_sh,
3435 unsigned long handle_flags);
3436 /* handle_stripe_clean_event
3437 * any written block on an uptodate or failed drive can be returned.
3438 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
3439 * never LOCKED, so we don't need to test 'failed' directly.
3441 static void handle_stripe_clean_event(struct r5conf *conf,
3442 struct stripe_head *sh, int disks, struct bio_list *return_bi)
3446 int discard_pending = 0;
3447 struct stripe_head *head_sh = sh;
3448 bool do_endio = false;
3450 for (i = disks; i--; )
3451 if (sh->dev[i].written) {
3453 if (!test_bit(R5_LOCKED, &dev->flags) &&
3454 (test_bit(R5_UPTODATE, &dev->flags) ||
3455 test_bit(R5_Discard, &dev->flags) ||
3456 test_bit(R5_SkipCopy, &dev->flags))) {
3457 /* We can return any write requests */
3458 struct bio *wbi, *wbi2;
3459 pr_debug("Return write for disc %d\n", i);
3460 if (test_and_clear_bit(R5_Discard, &dev->flags))
3461 clear_bit(R5_UPTODATE, &dev->flags);
3462 if (test_and_clear_bit(R5_SkipCopy, &dev->flags)) {
3463 WARN_ON(test_bit(R5_UPTODATE, &dev->flags));
3468 dev->page = dev->orig_page;
3470 dev->written = NULL;
3471 while (wbi && wbi->bi_iter.bi_sector <
3472 dev->sector + STRIPE_SECTORS) {
3473 wbi2 = r5_next_bio(wbi, dev->sector);
3474 if (!raid5_dec_bi_active_stripes(wbi)) {
3475 md_write_end(conf->mddev);
3476 bio_list_add(return_bi, wbi);
3480 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
3482 !test_bit(STRIPE_DEGRADED, &sh->state),
3484 if (head_sh->batch_head) {
3485 sh = list_first_entry(&sh->batch_list,
3488 if (sh != head_sh) {
3495 } else if (test_bit(R5_Discard, &dev->flags))
3496 discard_pending = 1;
3497 WARN_ON(test_bit(R5_SkipCopy, &dev->flags));
3498 WARN_ON(dev->page != dev->orig_page);
3500 if (!discard_pending &&
3501 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
3503 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
3504 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3505 if (sh->qd_idx >= 0) {
3506 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
3507 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
3509 /* now that discard is done we can proceed with any sync */
3510 clear_bit(STRIPE_DISCARD, &sh->state);
3512 * SCSI discard will change some bio fields and the stripe has
3513 * no updated data, so remove it from hash list and the stripe
3514 * will be reinitialized
3517 hash = sh->hash_lock_index;
3518 spin_lock_irq(conf->hash_locks + hash);
3520 spin_unlock_irq(conf->hash_locks + hash);
3521 if (head_sh->batch_head) {
3522 sh = list_first_entry(&sh->batch_list,
3523 struct stripe_head, batch_list);
3529 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
3530 set_bit(STRIPE_HANDLE, &sh->state);
3534 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
3535 if (atomic_dec_and_test(&conf->pending_full_writes))
3536 md_wakeup_thread(conf->mddev->thread);
3538 if (head_sh->batch_head && do_endio)
3539 break_stripe_batch_list(head_sh, STRIPE_EXPAND_SYNC_FLAGS);
3542 static void handle_stripe_dirtying(struct r5conf *conf,
3543 struct stripe_head *sh,
3544 struct stripe_head_state *s,
3547 int rmw = 0, rcw = 0, i;
3548 sector_t recovery_cp = conf->mddev->recovery_cp;
3550 /* Check whether resync is now happening or should start.
3551 * If yes, then the array is dirty (after unclean shutdown or
3552 * initial creation), so parity in some stripes might be inconsistent.
3553 * In this case, we need to always do reconstruct-write, to ensure
3554 * that in case of drive failure or read-error correction, we
3555 * generate correct data from the parity.
3557 if (conf->rmw_level == PARITY_DISABLE_RMW ||
3558 (recovery_cp < MaxSector && sh->sector >= recovery_cp &&
3560 /* Calculate the real rcw later - for now make it
3561 * look like rcw is cheaper
3564 pr_debug("force RCW rmw_level=%u, recovery_cp=%llu sh->sector=%llu\n",
3565 conf->rmw_level, (unsigned long long)recovery_cp,
3566 (unsigned long long)sh->sector);
3567 } else for (i = disks; i--; ) {
3568 /* would I have to read this buffer for read_modify_write */
3569 struct r5dev *dev = &sh->dev[i];
3570 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3571 !test_bit(R5_LOCKED, &dev->flags) &&
3572 !(test_bit(R5_UPTODATE, &dev->flags) ||
3573 test_bit(R5_Wantcompute, &dev->flags))) {
3574 if (test_bit(R5_Insync, &dev->flags))
3577 rmw += 2*disks; /* cannot read it */
3579 /* Would I have to read this buffer for reconstruct_write */
3580 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3581 i != sh->pd_idx && i != sh->qd_idx &&
3582 !test_bit(R5_LOCKED, &dev->flags) &&
3583 !(test_bit(R5_UPTODATE, &dev->flags) ||
3584 test_bit(R5_Wantcompute, &dev->flags))) {
3585 if (test_bit(R5_Insync, &dev->flags))
3591 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
3592 (unsigned long long)sh->sector, rmw, rcw);
3593 set_bit(STRIPE_HANDLE, &sh->state);
3594 if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_ENABLE_RMW)) && rmw > 0) {
3595 /* prefer read-modify-write, but need to get some data */
3596 if (conf->mddev->queue)
3597 blk_add_trace_msg(conf->mddev->queue,
3598 "raid5 rmw %llu %d",
3599 (unsigned long long)sh->sector, rmw);
3600 for (i = disks; i--; ) {
3601 struct r5dev *dev = &sh->dev[i];
3602 if ((dev->towrite || i == sh->pd_idx || i == sh->qd_idx) &&
3603 !test_bit(R5_LOCKED, &dev->flags) &&
3604 !(test_bit(R5_UPTODATE, &dev->flags) ||
3605 test_bit(R5_Wantcompute, &dev->flags)) &&
3606 test_bit(R5_Insync, &dev->flags)) {
3607 if (test_bit(STRIPE_PREREAD_ACTIVE,
3609 pr_debug("Read_old block %d for r-m-w\n",
3611 set_bit(R5_LOCKED, &dev->flags);
3612 set_bit(R5_Wantread, &dev->flags);
3615 set_bit(STRIPE_DELAYED, &sh->state);
3616 set_bit(STRIPE_HANDLE, &sh->state);
3621 if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_ENABLE_RMW)) && rcw > 0) {
3622 /* want reconstruct write, but need to get some data */
3625 for (i = disks; i--; ) {
3626 struct r5dev *dev = &sh->dev[i];
3627 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3628 i != sh->pd_idx && i != sh->qd_idx &&
3629 !test_bit(R5_LOCKED, &dev->flags) &&
3630 !(test_bit(R5_UPTODATE, &dev->flags) ||
3631 test_bit(R5_Wantcompute, &dev->flags))) {
3633 if (test_bit(R5_Insync, &dev->flags) &&
3634 test_bit(STRIPE_PREREAD_ACTIVE,
3636 pr_debug("Read_old block "
3637 "%d for Reconstruct\n", i);
3638 set_bit(R5_LOCKED, &dev->flags);
3639 set_bit(R5_Wantread, &dev->flags);
3643 set_bit(STRIPE_DELAYED, &sh->state);
3644 set_bit(STRIPE_HANDLE, &sh->state);
3648 if (rcw && conf->mddev->queue)
3649 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
3650 (unsigned long long)sh->sector,
3651 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
3654 if (rcw > disks && rmw > disks &&
3655 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3656 set_bit(STRIPE_DELAYED, &sh->state);
3658 /* now if nothing is locked, and if we have enough data,
3659 * we can start a write request
3661 /* since handle_stripe can be called at any time we need to handle the
3662 * case where a compute block operation has been submitted and then a
3663 * subsequent call wants to start a write request. raid_run_ops only
3664 * handles the case where compute block and reconstruct are requested
3665 * simultaneously. If this is not the case then new writes need to be
3666 * held off until the compute completes.
3668 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
3669 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
3670 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
3671 schedule_reconstruction(sh, s, rcw == 0, 0);
3674 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
3675 struct stripe_head_state *s, int disks)
3677 struct r5dev *dev = NULL;
3679 BUG_ON(sh->batch_head);
3680 set_bit(STRIPE_HANDLE, &sh->state);
3682 switch (sh->check_state) {
3683 case check_state_idle:
3684 /* start a new check operation if there are no failures */
3685 if (s->failed == 0) {
3686 BUG_ON(s->uptodate != disks);
3687 sh->check_state = check_state_run;
3688 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3689 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3693 dev = &sh->dev[s->failed_num[0]];
3695 case check_state_compute_result:
3696 sh->check_state = check_state_idle;
3698 dev = &sh->dev[sh->pd_idx];
3700 /* check that a write has not made the stripe insync */
3701 if (test_bit(STRIPE_INSYNC, &sh->state))
3704 /* either failed parity check, or recovery is happening */
3705 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3706 BUG_ON(s->uptodate != disks);
3708 set_bit(R5_LOCKED, &dev->flags);
3710 set_bit(R5_Wantwrite, &dev->flags);
3712 clear_bit(STRIPE_DEGRADED, &sh->state);
3713 set_bit(STRIPE_INSYNC, &sh->state);
3715 case check_state_run:
3716 break; /* we will be called again upon completion */
3717 case check_state_check_result:
3718 sh->check_state = check_state_idle;
3720 /* if a failure occurred during the check operation, leave
3721 * STRIPE_INSYNC not set and let the stripe be handled again
3726 /* handle a successful check operation, if parity is correct
3727 * we are done. Otherwise update the mismatch count and repair
3728 * parity if !MD_RECOVERY_CHECK
3730 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
3731 /* parity is correct (on disc,
3732 * not in buffer any more)
3734 set_bit(STRIPE_INSYNC, &sh->state);
3736 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3737 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3738 /* don't try to repair!! */
3739 set_bit(STRIPE_INSYNC, &sh->state);
3741 sh->check_state = check_state_compute_run;
3742 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3743 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3744 set_bit(R5_Wantcompute,
3745 &sh->dev[sh->pd_idx].flags);
3746 sh->ops.target = sh->pd_idx;
3747 sh->ops.target2 = -1;
3752 case check_state_compute_run:
3755 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3756 __func__, sh->check_state,
3757 (unsigned long long) sh->sector);
3762 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
3763 struct stripe_head_state *s,
3766 int pd_idx = sh->pd_idx;
3767 int qd_idx = sh->qd_idx;
3770 BUG_ON(sh->batch_head);
3771 set_bit(STRIPE_HANDLE, &sh->state);
3773 BUG_ON(s->failed > 2);
3775 /* Want to check and possibly repair P and Q.
3776 * However there could be one 'failed' device, in which
3777 * case we can only check one of them, possibly using the
3778 * other to generate missing data
3781 switch (sh->check_state) {
3782 case check_state_idle:
3783 /* start a new check operation if there are < 2 failures */
3784 if (s->failed == s->q_failed) {
3785 /* The only possible failed device holds Q, so it
3786 * makes sense to check P (If anything else were failed,
3787 * we would have used P to recreate it).
3789 sh->check_state = check_state_run;
3791 if (!s->q_failed && s->failed < 2) {
3792 /* Q is not failed, and we didn't use it to generate
3793 * anything, so it makes sense to check it
3795 if (sh->check_state == check_state_run)
3796 sh->check_state = check_state_run_pq;
3798 sh->check_state = check_state_run_q;
3801 /* discard potentially stale zero_sum_result */
3802 sh->ops.zero_sum_result = 0;
3804 if (sh->check_state == check_state_run) {
3805 /* async_xor_zero_sum destroys the contents of P */
3806 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3809 if (sh->check_state >= check_state_run &&
3810 sh->check_state <= check_state_run_pq) {
3811 /* async_syndrome_zero_sum preserves P and Q, so
3812 * no need to mark them !uptodate here
3814 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3818 /* we have 2-disk failure */
3819 BUG_ON(s->failed != 2);
3821 case check_state_compute_result:
3822 sh->check_state = check_state_idle;
3824 /* check that a write has not made the stripe insync */
3825 if (test_bit(STRIPE_INSYNC, &sh->state))
3828 /* now write out any block on a failed drive,
3829 * or P or Q if they were recomputed
3831 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
3832 if (s->failed == 2) {
3833 dev = &sh->dev[s->failed_num[1]];
3835 set_bit(R5_LOCKED, &dev->flags);
3836 set_bit(R5_Wantwrite, &dev->flags);
3838 if (s->failed >= 1) {
3839 dev = &sh->dev[s->failed_num[0]];
3841 set_bit(R5_LOCKED, &dev->flags);
3842 set_bit(R5_Wantwrite, &dev->flags);
3844 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3845 dev = &sh->dev[pd_idx];
3847 set_bit(R5_LOCKED, &dev->flags);
3848 set_bit(R5_Wantwrite, &dev->flags);
3850 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3851 dev = &sh->dev[qd_idx];
3853 set_bit(R5_LOCKED, &dev->flags);
3854 set_bit(R5_Wantwrite, &dev->flags);
3856 clear_bit(STRIPE_DEGRADED, &sh->state);
3858 set_bit(STRIPE_INSYNC, &sh->state);
3860 case check_state_run:
3861 case check_state_run_q:
3862 case check_state_run_pq:
3863 break; /* we will be called again upon completion */
3864 case check_state_check_result:
3865 sh->check_state = check_state_idle;
3867 /* handle a successful check operation, if parity is correct
3868 * we are done. Otherwise update the mismatch count and repair
3869 * parity if !MD_RECOVERY_CHECK
3871 if (sh->ops.zero_sum_result == 0) {
3872 /* both parities are correct */
3874 set_bit(STRIPE_INSYNC, &sh->state);
3876 /* in contrast to the raid5 case we can validate
3877 * parity, but still have a failure to write
3880 sh->check_state = check_state_compute_result;
3881 /* Returning at this point means that we may go
3882 * off and bring p and/or q uptodate again so
3883 * we make sure to check zero_sum_result again
3884 * to verify if p or q need writeback
3888 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3889 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3890 /* don't try to repair!! */
3891 set_bit(STRIPE_INSYNC, &sh->state);
3893 int *target = &sh->ops.target;
3895 sh->ops.target = -1;
3896 sh->ops.target2 = -1;
3897 sh->check_state = check_state_compute_run;
3898 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3899 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3900 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3901 set_bit(R5_Wantcompute,
3902 &sh->dev[pd_idx].flags);
3904 target = &sh->ops.target2;
3907 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3908 set_bit(R5_Wantcompute,
3909 &sh->dev[qd_idx].flags);
3916 case check_state_compute_run:
3919 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3920 __func__, sh->check_state,
3921 (unsigned long long) sh->sector);
3926 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
3930 /* We have read all the blocks in this stripe and now we need to
3931 * copy some of them into a target stripe for expand.
3933 struct dma_async_tx_descriptor *tx = NULL;
3934 BUG_ON(sh->batch_head);
3935 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3936 for (i = 0; i < sh->disks; i++)
3937 if (i != sh->pd_idx && i != sh->qd_idx) {
3939 struct stripe_head *sh2;
3940 struct async_submit_ctl submit;
3942 sector_t bn = compute_blocknr(sh, i, 1);
3943 sector_t s = raid5_compute_sector(conf, bn, 0,
3945 sh2 = get_active_stripe(conf, s, 0, 1, 1);
3947 /* so far only the early blocks of this stripe
3948 * have been requested. When later blocks
3949 * get requested, we will try again
3952 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3953 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3954 /* must have already done this block */
3955 release_stripe(sh2);
3959 /* place all the copies on one channel */
3960 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
3961 tx = async_memcpy(sh2->dev[dd_idx].page,
3962 sh->dev[i].page, 0, 0, STRIPE_SIZE,
3965 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
3966 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
3967 for (j = 0; j < conf->raid_disks; j++)
3968 if (j != sh2->pd_idx &&
3970 !test_bit(R5_Expanded, &sh2->dev[j].flags))
3972 if (j == conf->raid_disks) {
3973 set_bit(STRIPE_EXPAND_READY, &sh2->state);
3974 set_bit(STRIPE_HANDLE, &sh2->state);
3976 release_stripe(sh2);
3979 /* done submitting copies, wait for them to complete */
3980 async_tx_quiesce(&tx);
3984 * handle_stripe - do things to a stripe.
3986 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3987 * state of various bits to see what needs to be done.
3989 * return some read requests which now have data
3990 * return some write requests which are safely on storage
3991 * schedule a read on some buffers
3992 * schedule a write of some buffers
3993 * return confirmation of parity correctness
3997 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
3999 struct r5conf *conf = sh->raid_conf;
4000 int disks = sh->disks;
4003 int do_recovery = 0;
4005 memset(s, 0, sizeof(*s));
4007 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state) && !sh->batch_head;
4008 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state) && !sh->batch_head;
4009 s->failed_num[0] = -1;
4010 s->failed_num[1] = -1;
4012 /* Now to look around and see what can be done */
4014 for (i=disks; i--; ) {
4015 struct md_rdev *rdev;
4022 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
4024 dev->toread, dev->towrite, dev->written);
4025 /* maybe we can reply to a read
4027 * new wantfill requests are only permitted while
4028 * ops_complete_biofill is guaranteed to be inactive
4030 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
4031 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
4032 set_bit(R5_Wantfill, &dev->flags);
4034 /* now count some things */
4035 if (test_bit(R5_LOCKED, &dev->flags))
4037 if (test_bit(R5_UPTODATE, &dev->flags))
4039 if (test_bit(R5_Wantcompute, &dev->flags)) {
4041 BUG_ON(s->compute > 2);
4044 if (test_bit(R5_Wantfill, &dev->flags))
4046 else if (dev->toread)
4050 if (!test_bit(R5_OVERWRITE, &dev->flags))
4055 /* Prefer to use the replacement for reads, but only
4056 * if it is recovered enough and has no bad blocks.
4058 rdev = rcu_dereference(conf->disks[i].replacement);
4059 if (rdev && !test_bit(Faulty, &rdev->flags) &&
4060 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
4061 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4062 &first_bad, &bad_sectors))
4063 set_bit(R5_ReadRepl, &dev->flags);
4065 if (rdev && !test_bit(Faulty, &rdev->flags))
4066 set_bit(R5_NeedReplace, &dev->flags);
4068 clear_bit(R5_NeedReplace, &dev->flags);
4069 rdev = rcu_dereference(conf->disks[i].rdev);
4070 clear_bit(R5_ReadRepl, &dev->flags);
4072 if (rdev && test_bit(Faulty, &rdev->flags))
4075 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
4076 &first_bad, &bad_sectors);
4077 if (s->blocked_rdev == NULL
4078 && (test_bit(Blocked, &rdev->flags)
4081 set_bit(BlockedBadBlocks,
4083 s->blocked_rdev = rdev;
4084 atomic_inc(&rdev->nr_pending);
4087 clear_bit(R5_Insync, &dev->flags);
4091 /* also not in-sync */
4092 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
4093 test_bit(R5_UPTODATE, &dev->flags)) {
4094 /* treat as in-sync, but with a read error
4095 * which we can now try to correct
4097 set_bit(R5_Insync, &dev->flags);
4098 set_bit(R5_ReadError, &dev->flags);
4100 } else if (test_bit(In_sync, &rdev->flags))
4101 set_bit(R5_Insync, &dev->flags);
4102 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
4103 /* in sync if before recovery_offset */
4104 set_bit(R5_Insync, &dev->flags);
4105 else if (test_bit(R5_UPTODATE, &dev->flags) &&
4106 test_bit(R5_Expanded, &dev->flags))
4107 /* If we've reshaped into here, we assume it is Insync.
4108 * We will shortly update recovery_offset to make
4111 set_bit(R5_Insync, &dev->flags);
4113 if (test_bit(R5_WriteError, &dev->flags)) {
4114 /* This flag does not apply to '.replacement'
4115 * only to .rdev, so make sure to check that*/
4116 struct md_rdev *rdev2 = rcu_dereference(
4117 conf->disks[i].rdev);
4119 clear_bit(R5_Insync, &dev->flags);
4120 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4121 s->handle_bad_blocks = 1;
4122 atomic_inc(&rdev2->nr_pending);
4124 clear_bit(R5_WriteError, &dev->flags);
4126 if (test_bit(R5_MadeGood, &dev->flags)) {
4127 /* This flag does not apply to '.replacement'
4128 * only to .rdev, so make sure to check that*/
4129 struct md_rdev *rdev2 = rcu_dereference(
4130 conf->disks[i].rdev);
4131 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4132 s->handle_bad_blocks = 1;
4133 atomic_inc(&rdev2->nr_pending);
4135 clear_bit(R5_MadeGood, &dev->flags);
4137 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
4138 struct md_rdev *rdev2 = rcu_dereference(
4139 conf->disks[i].replacement);
4140 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
4141 s->handle_bad_blocks = 1;
4142 atomic_inc(&rdev2->nr_pending);
4144 clear_bit(R5_MadeGoodRepl, &dev->flags);
4146 if (!test_bit(R5_Insync, &dev->flags)) {
4147 /* The ReadError flag will just be confusing now */
4148 clear_bit(R5_ReadError, &dev->flags);
4149 clear_bit(R5_ReWrite, &dev->flags);
4151 if (test_bit(R5_ReadError, &dev->flags))
4152 clear_bit(R5_Insync, &dev->flags);
4153 if (!test_bit(R5_Insync, &dev->flags)) {
4155 s->failed_num[s->failed] = i;
4157 if (rdev && !test_bit(Faulty, &rdev->flags))
4161 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4162 /* If there is a failed device being replaced,
4163 * we must be recovering.
4164 * else if we are after recovery_cp, we must be syncing
4165 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
4166 * else we can only be replacing
4167 * sync and recovery both need to read all devices, and so
4168 * use the same flag.
4171 sh->sector >= conf->mddev->recovery_cp ||
4172 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
4180 static int clear_batch_ready(struct stripe_head *sh)
4182 /* Return '1' if this is a member of batch, or
4183 * '0' if it is a lone stripe or a head which can now be
4186 struct stripe_head *tmp;
4187 if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state))
4188 return (sh->batch_head && sh->batch_head != sh);
4189 spin_lock(&sh->stripe_lock);
4190 if (!sh->batch_head) {
4191 spin_unlock(&sh->stripe_lock);
4196 * this stripe could be added to a batch list before we check
4197 * BATCH_READY, skips it
4199 if (sh->batch_head != sh) {
4200 spin_unlock(&sh->stripe_lock);
4203 spin_lock(&sh->batch_lock);
4204 list_for_each_entry(tmp, &sh->batch_list, batch_list)
4205 clear_bit(STRIPE_BATCH_READY, &tmp->state);
4206 spin_unlock(&sh->batch_lock);
4207 spin_unlock(&sh->stripe_lock);
4210 * BATCH_READY is cleared, no new stripes can be added.
4211 * batch_list can be accessed without lock
4216 static void break_stripe_batch_list(struct stripe_head *head_sh,
4217 unsigned long handle_flags)
4219 struct stripe_head *sh, *next;
4223 list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) {
4225 list_del_init(&sh->batch_list);
4227 WARN_ON_ONCE(sh->state & ((1 << STRIPE_ACTIVE) |
4228 (1 << STRIPE_SYNCING) |
4229 (1 << STRIPE_REPLACED) |
4230 (1 << STRIPE_PREREAD_ACTIVE) |
4231 (1 << STRIPE_DELAYED) |
4232 (1 << STRIPE_BIT_DELAY) |
4233 (1 << STRIPE_FULL_WRITE) |
4234 (1 << STRIPE_BIOFILL_RUN) |
4235 (1 << STRIPE_COMPUTE_RUN) |
4236 (1 << STRIPE_OPS_REQ_PENDING) |
4237 (1 << STRIPE_DISCARD) |
4238 (1 << STRIPE_BATCH_READY) |
4239 (1 << STRIPE_BATCH_ERR) |
4240 (1 << STRIPE_BITMAP_PENDING)));
4241 WARN_ON_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) |
4242 (1 << STRIPE_REPLACED)));
4244 set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
4245 (1 << STRIPE_DEGRADED)),
4246 head_sh->state & (1 << STRIPE_INSYNC));
4248 sh->check_state = head_sh->check_state;
4249 sh->reconstruct_state = head_sh->reconstruct_state;
4250 for (i = 0; i < sh->disks; i++) {
4251 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
4253 sh->dev[i].flags = head_sh->dev[i].flags &
4254 (~((1 << R5_WriteError) | (1 << R5_Overlap)));
4256 spin_lock_irq(&sh->stripe_lock);
4257 sh->batch_head = NULL;
4258 spin_unlock_irq(&sh->stripe_lock);
4259 if (handle_flags == 0 ||
4260 sh->state & handle_flags)
4261 set_bit(STRIPE_HANDLE, &sh->state);
4264 spin_lock_irq(&head_sh->stripe_lock);
4265 head_sh->batch_head = NULL;
4266 spin_unlock_irq(&head_sh->stripe_lock);
4267 for (i = 0; i < head_sh->disks; i++)
4268 if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
4270 if (head_sh->state & handle_flags)
4271 set_bit(STRIPE_HANDLE, &head_sh->state);
4274 wake_up(&head_sh->raid_conf->wait_for_overlap);
4277 static void handle_stripe(struct stripe_head *sh)
4279 struct stripe_head_state s;
4280 struct r5conf *conf = sh->raid_conf;
4283 int disks = sh->disks;
4284 struct r5dev *pdev, *qdev;
4286 clear_bit(STRIPE_HANDLE, &sh->state);
4287 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
4288 /* already being handled, ensure it gets handled
4289 * again when current action finishes */
4290 set_bit(STRIPE_HANDLE, &sh->state);
4294 if (clear_batch_ready(sh) ) {
4295 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4299 if (test_and_clear_bit(STRIPE_BATCH_ERR, &sh->state))
4300 break_stripe_batch_list(sh, 0);
4302 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) {
4303 spin_lock(&sh->stripe_lock);
4304 /* Cannot process 'sync' concurrently with 'discard' */
4305 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
4306 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
4307 set_bit(STRIPE_SYNCING, &sh->state);
4308 clear_bit(STRIPE_INSYNC, &sh->state);
4309 clear_bit(STRIPE_REPLACED, &sh->state);
4311 spin_unlock(&sh->stripe_lock);
4313 clear_bit(STRIPE_DELAYED, &sh->state);
4315 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
4316 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
4317 (unsigned long long)sh->sector, sh->state,
4318 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
4319 sh->check_state, sh->reconstruct_state);
4321 analyse_stripe(sh, &s);
4323 if (s.handle_bad_blocks) {
4324 set_bit(STRIPE_HANDLE, &sh->state);
4328 if (unlikely(s.blocked_rdev)) {
4329 if (s.syncing || s.expanding || s.expanded ||
4330 s.replacing || s.to_write || s.written) {
4331 set_bit(STRIPE_HANDLE, &sh->state);
4334 /* There is nothing for the blocked_rdev to block */
4335 rdev_dec_pending(s.blocked_rdev, conf->mddev);
4336 s.blocked_rdev = NULL;
4339 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
4340 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
4341 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
4344 pr_debug("locked=%d uptodate=%d to_read=%d"
4345 " to_write=%d failed=%d failed_num=%d,%d\n",
4346 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
4347 s.failed_num[0], s.failed_num[1]);
4348 /* check if the array has lost more than max_degraded devices and,
4349 * if so, some requests might need to be failed.
4351 if (s.failed > conf->max_degraded) {
4352 sh->check_state = 0;
4353 sh->reconstruct_state = 0;
4354 break_stripe_batch_list(sh, 0);
4355 if (s.to_read+s.to_write+s.written)
4356 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
4357 if (s.syncing + s.replacing)
4358 handle_failed_sync(conf, sh, &s);
4361 /* Now we check to see if any write operations have recently
4365 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
4367 if (sh->reconstruct_state == reconstruct_state_drain_result ||
4368 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
4369 sh->reconstruct_state = reconstruct_state_idle;
4371 /* All the 'written' buffers and the parity block are ready to
4372 * be written back to disk
4374 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
4375 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
4376 BUG_ON(sh->qd_idx >= 0 &&
4377 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
4378 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
4379 for (i = disks; i--; ) {
4380 struct r5dev *dev = &sh->dev[i];
4381 if (test_bit(R5_LOCKED, &dev->flags) &&
4382 (i == sh->pd_idx || i == sh->qd_idx ||
4384 pr_debug("Writing block %d\n", i);
4385 set_bit(R5_Wantwrite, &dev->flags);
4390 if (!test_bit(R5_Insync, &dev->flags) ||
4391 ((i == sh->pd_idx || i == sh->qd_idx) &&
4393 set_bit(STRIPE_INSYNC, &sh->state);
4396 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4397 s.dec_preread_active = 1;
4401 * might be able to return some write requests if the parity blocks
4402 * are safe, or on a failed drive
4404 pdev = &sh->dev[sh->pd_idx];
4405 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
4406 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
4407 qdev = &sh->dev[sh->qd_idx];
4408 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
4409 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
4413 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
4414 && !test_bit(R5_LOCKED, &pdev->flags)
4415 && (test_bit(R5_UPTODATE, &pdev->flags) ||
4416 test_bit(R5_Discard, &pdev->flags))))) &&
4417 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
4418 && !test_bit(R5_LOCKED, &qdev->flags)
4419 && (test_bit(R5_UPTODATE, &qdev->flags) ||
4420 test_bit(R5_Discard, &qdev->flags))))))
4421 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
4423 /* Now we might consider reading some blocks, either to check/generate
4424 * parity, or to satisfy requests
4425 * or to load a block that is being partially written.
4427 if (s.to_read || s.non_overwrite
4428 || (conf->level == 6 && s.to_write && s.failed)
4429 || (s.syncing && (s.uptodate + s.compute < disks))
4432 handle_stripe_fill(sh, &s, disks);
4434 /* Now to consider new write requests and what else, if anything
4435 * should be read. We do not handle new writes when:
4436 * 1/ A 'write' operation (copy+xor) is already in flight.
4437 * 2/ A 'check' operation is in flight, as it may clobber the parity
4440 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
4441 handle_stripe_dirtying(conf, sh, &s, disks);
4443 /* maybe we need to check and possibly fix the parity for this stripe
4444 * Any reads will already have been scheduled, so we just see if enough
4445 * data is available. The parity check is held off while parity
4446 * dependent operations are in flight.
4448 if (sh->check_state ||
4449 (s.syncing && s.locked == 0 &&
4450 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4451 !test_bit(STRIPE_INSYNC, &sh->state))) {
4452 if (conf->level == 6)
4453 handle_parity_checks6(conf, sh, &s, disks);
4455 handle_parity_checks5(conf, sh, &s, disks);
4458 if ((s.replacing || s.syncing) && s.locked == 0
4459 && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
4460 && !test_bit(STRIPE_REPLACED, &sh->state)) {
4461 /* Write out to replacement devices where possible */
4462 for (i = 0; i < conf->raid_disks; i++)
4463 if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
4464 WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
4465 set_bit(R5_WantReplace, &sh->dev[i].flags);
4466 set_bit(R5_LOCKED, &sh->dev[i].flags);
4470 set_bit(STRIPE_INSYNC, &sh->state);
4471 set_bit(STRIPE_REPLACED, &sh->state);
4473 if ((s.syncing || s.replacing) && s.locked == 0 &&
4474 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
4475 test_bit(STRIPE_INSYNC, &sh->state)) {
4476 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4477 clear_bit(STRIPE_SYNCING, &sh->state);
4478 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
4479 wake_up(&conf->wait_for_overlap);
4482 /* If the failed drives are just a ReadError, then we might need
4483 * to progress the repair/check process
4485 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
4486 for (i = 0; i < s.failed; i++) {
4487 struct r5dev *dev = &sh->dev[s.failed_num[i]];
4488 if (test_bit(R5_ReadError, &dev->flags)
4489 && !test_bit(R5_LOCKED, &dev->flags)
4490 && test_bit(R5_UPTODATE, &dev->flags)
4492 if (!test_bit(R5_ReWrite, &dev->flags)) {
4493 set_bit(R5_Wantwrite, &dev->flags);
4494 set_bit(R5_ReWrite, &dev->flags);
4495 set_bit(R5_LOCKED, &dev->flags);
4498 /* let's read it back */
4499 set_bit(R5_Wantread, &dev->flags);
4500 set_bit(R5_LOCKED, &dev->flags);
4506 /* Finish reconstruct operations initiated by the expansion process */
4507 if (sh->reconstruct_state == reconstruct_state_result) {
4508 struct stripe_head *sh_src
4509 = get_active_stripe(conf, sh->sector, 1, 1, 1);
4510 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
4511 /* sh cannot be written until sh_src has been read.
4512 * so arrange for sh to be delayed a little
4514 set_bit(STRIPE_DELAYED, &sh->state);
4515 set_bit(STRIPE_HANDLE, &sh->state);
4516 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
4518 atomic_inc(&conf->preread_active_stripes);
4519 release_stripe(sh_src);
4523 release_stripe(sh_src);
4525 sh->reconstruct_state = reconstruct_state_idle;
4526 clear_bit(STRIPE_EXPANDING, &sh->state);
4527 for (i = conf->raid_disks; i--; ) {
4528 set_bit(R5_Wantwrite, &sh->dev[i].flags);
4529 set_bit(R5_LOCKED, &sh->dev[i].flags);
4534 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
4535 !sh->reconstruct_state) {
4536 /* Need to write out all blocks after computing parity */
4537 sh->disks = conf->raid_disks;
4538 stripe_set_idx(sh->sector, conf, 0, sh);
4539 schedule_reconstruction(sh, &s, 1, 1);
4540 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
4541 clear_bit(STRIPE_EXPAND_READY, &sh->state);
4542 atomic_dec(&conf->reshape_stripes);
4543 wake_up(&conf->wait_for_overlap);
4544 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
4547 if (s.expanding && s.locked == 0 &&
4548 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
4549 handle_stripe_expansion(conf, sh);
4552 /* wait for this device to become unblocked */
4553 if (unlikely(s.blocked_rdev)) {
4554 if (conf->mddev->external)
4555 md_wait_for_blocked_rdev(s.blocked_rdev,
4558 /* Internal metadata will immediately
4559 * be written by raid5d, so we don't
4560 * need to wait here.
4562 rdev_dec_pending(s.blocked_rdev,
4566 if (s.handle_bad_blocks)
4567 for (i = disks; i--; ) {
4568 struct md_rdev *rdev;
4569 struct r5dev *dev = &sh->dev[i];
4570 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
4571 /* We own a safe reference to the rdev */
4572 rdev = conf->disks[i].rdev;
4573 if (!rdev_set_badblocks(rdev, sh->sector,
4575 md_error(conf->mddev, rdev);
4576 rdev_dec_pending(rdev, conf->mddev);
4578 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
4579 rdev = conf->disks[i].rdev;
4580 rdev_clear_badblocks(rdev, sh->sector,
4582 rdev_dec_pending(rdev, conf->mddev);
4584 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
4585 rdev = conf->disks[i].replacement;
4587 /* rdev have been moved down */
4588 rdev = conf->disks[i].rdev;
4589 rdev_clear_badblocks(rdev, sh->sector,
4591 rdev_dec_pending(rdev, conf->mddev);
4596 raid_run_ops(sh, s.ops_request);
4600 if (s.dec_preread_active) {
4601 /* We delay this until after ops_run_io so that if make_request
4602 * is waiting on a flush, it won't continue until the writes
4603 * have actually been submitted.
4605 atomic_dec(&conf->preread_active_stripes);
4606 if (atomic_read(&conf->preread_active_stripes) <
4608 md_wakeup_thread(conf->mddev->thread);
4611 if (!bio_list_empty(&s.return_bi)) {
4612 if (test_bit(MD_CHANGE_PENDING, &conf->mddev->flags)) {
4613 spin_lock_irq(&conf->device_lock);
4614 bio_list_merge(&conf->return_bi, &s.return_bi);
4615 spin_unlock_irq(&conf->device_lock);
4616 md_wakeup_thread(conf->mddev->thread);
4618 return_io(&s.return_bi);
4621 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
4624 static void raid5_activate_delayed(struct r5conf *conf)
4626 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
4627 while (!list_empty(&conf->delayed_list)) {
4628 struct list_head *l = conf->delayed_list.next;
4629 struct stripe_head *sh;
4630 sh = list_entry(l, struct stripe_head, lru);
4632 clear_bit(STRIPE_DELAYED, &sh->state);
4633 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4634 atomic_inc(&conf->preread_active_stripes);
4635 list_add_tail(&sh->lru, &conf->hold_list);
4636 raid5_wakeup_stripe_thread(sh);
4641 static void activate_bit_delay(struct r5conf *conf,
4642 struct list_head *temp_inactive_list)
4644 /* device_lock is held */
4645 struct list_head head;
4646 list_add(&head, &conf->bitmap_list);
4647 list_del_init(&conf->bitmap_list);
4648 while (!list_empty(&head)) {
4649 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
4651 list_del_init(&sh->lru);
4652 atomic_inc(&sh->count);
4653 hash = sh->hash_lock_index;
4654 __release_stripe(conf, sh, &temp_inactive_list[hash]);
4658 static int raid5_congested(struct mddev *mddev, int bits)
4660 struct r5conf *conf = mddev->private;
4662 /* No difference between reads and writes. Just check
4663 * how busy the stripe_cache is
4666 if (test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
4670 if (atomic_read(&conf->empty_inactive_list_nr))
4676 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
4678 struct r5conf *conf = mddev->private;
4679 sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev);
4680 unsigned int chunk_sectors;
4681 unsigned int bio_sectors = bio_sectors(bio);
4683 chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors);
4684 return chunk_sectors >=
4685 ((sector & (chunk_sectors - 1)) + bio_sectors);
4689 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
4690 * later sampled by raid5d.
4692 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
4694 unsigned long flags;
4696 spin_lock_irqsave(&conf->device_lock, flags);
4698 bi->bi_next = conf->retry_read_aligned_list;
4699 conf->retry_read_aligned_list = bi;
4701 spin_unlock_irqrestore(&conf->device_lock, flags);
4702 md_wakeup_thread(conf->mddev->thread);
4705 static struct bio *remove_bio_from_retry(struct r5conf *conf)
4709 bi = conf->retry_read_aligned;
4711 conf->retry_read_aligned = NULL;
4714 bi = conf->retry_read_aligned_list;
4716 conf->retry_read_aligned_list = bi->bi_next;
4719 * this sets the active strip count to 1 and the processed
4720 * strip count to zero (upper 8 bits)
4722 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
4729 * The "raid5_align_endio" should check if the read succeeded and if it
4730 * did, call bio_endio on the original bio (having bio_put the new bio
4732 * If the read failed..
4734 static void raid5_align_endio(struct bio *bi)
4736 struct bio* raid_bi = bi->bi_private;
4737 struct mddev *mddev;
4738 struct r5conf *conf;
4739 struct md_rdev *rdev;
4740 int error = bi->bi_error;
4744 rdev = (void*)raid_bi->bi_next;
4745 raid_bi->bi_next = NULL;
4746 mddev = rdev->mddev;
4747 conf = mddev->private;
4749 rdev_dec_pending(rdev, conf->mddev);
4752 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
4755 if (atomic_dec_and_test(&conf->active_aligned_reads))
4756 wake_up(&conf->wait_for_quiescent);
4760 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
4762 add_bio_to_retry(raid_bi, conf);
4765 static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)
4767 struct r5conf *conf = mddev->private;
4769 struct bio* align_bi;
4770 struct md_rdev *rdev;
4771 sector_t end_sector;
4773 if (!in_chunk_boundary(mddev, raid_bio)) {
4774 pr_debug("%s: non aligned\n", __func__);
4778 * use bio_clone_mddev to make a copy of the bio
4780 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
4784 * set bi_end_io to a new function, and set bi_private to the
4787 align_bi->bi_end_io = raid5_align_endio;
4788 align_bi->bi_private = raid_bio;
4792 align_bi->bi_iter.bi_sector =
4793 raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector,
4796 end_sector = bio_end_sector(align_bi);
4798 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
4799 if (!rdev || test_bit(Faulty, &rdev->flags) ||
4800 rdev->recovery_offset < end_sector) {
4801 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
4803 (test_bit(Faulty, &rdev->flags) ||
4804 !(test_bit(In_sync, &rdev->flags) ||
4805 rdev->recovery_offset >= end_sector)))
4812 atomic_inc(&rdev->nr_pending);
4814 raid_bio->bi_next = (void*)rdev;
4815 align_bi->bi_bdev = rdev->bdev;
4816 bio_clear_flag(align_bi, BIO_SEG_VALID);
4818 if (is_badblock(rdev, align_bi->bi_iter.bi_sector,
4819 bio_sectors(align_bi),
4820 &first_bad, &bad_sectors)) {
4822 rdev_dec_pending(rdev, mddev);
4826 /* No reshape active, so we can trust rdev->data_offset */
4827 align_bi->bi_iter.bi_sector += rdev->data_offset;
4829 spin_lock_irq(&conf->device_lock);
4830 wait_event_lock_irq(conf->wait_for_quiescent,
4833 atomic_inc(&conf->active_aligned_reads);
4834 spin_unlock_irq(&conf->device_lock);
4837 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4838 align_bi, disk_devt(mddev->gendisk),
4839 raid_bio->bi_iter.bi_sector);
4840 generic_make_request(align_bi);
4849 static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
4854 sector_t sector = raid_bio->bi_iter.bi_sector;
4855 unsigned chunk_sects = mddev->chunk_sectors;
4856 unsigned sectors = chunk_sects - (sector & (chunk_sects-1));
4858 if (sectors < bio_sectors(raid_bio)) {
4859 split = bio_split(raid_bio, sectors, GFP_NOIO, fs_bio_set);
4860 bio_chain(split, raid_bio);
4864 if (!raid5_read_one_chunk(mddev, split)) {
4865 if (split != raid_bio)
4866 generic_make_request(raid_bio);
4869 } while (split != raid_bio);
4874 /* __get_priority_stripe - get the next stripe to process
4876 * Full stripe writes are allowed to pass preread active stripes up until
4877 * the bypass_threshold is exceeded. In general the bypass_count
4878 * increments when the handle_list is handled before the hold_list; however, it
4879 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4880 * stripe with in flight i/o. The bypass_count will be reset when the
4881 * head of the hold_list has changed, i.e. the head was promoted to the
4884 static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
4886 struct stripe_head *sh = NULL, *tmp;
4887 struct list_head *handle_list = NULL;
4888 struct r5worker_group *wg = NULL;
4890 if (conf->worker_cnt_per_group == 0) {
4891 handle_list = &conf->handle_list;
4892 } else if (group != ANY_GROUP) {
4893 handle_list = &conf->worker_groups[group].handle_list;
4894 wg = &conf->worker_groups[group];
4897 for (i = 0; i < conf->group_cnt; i++) {
4898 handle_list = &conf->worker_groups[i].handle_list;
4899 wg = &conf->worker_groups[i];
4900 if (!list_empty(handle_list))
4905 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4907 list_empty(handle_list) ? "empty" : "busy",
4908 list_empty(&conf->hold_list) ? "empty" : "busy",
4909 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4911 if (!list_empty(handle_list)) {
4912 sh = list_entry(handle_list->next, typeof(*sh), lru);
4914 if (list_empty(&conf->hold_list))
4915 conf->bypass_count = 0;
4916 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4917 if (conf->hold_list.next == conf->last_hold)
4918 conf->bypass_count++;
4920 conf->last_hold = conf->hold_list.next;
4921 conf->bypass_count -= conf->bypass_threshold;
4922 if (conf->bypass_count < 0)
4923 conf->bypass_count = 0;
4926 } else if (!list_empty(&conf->hold_list) &&
4927 ((conf->bypass_threshold &&
4928 conf->bypass_count > conf->bypass_threshold) ||
4929 atomic_read(&conf->pending_full_writes) == 0)) {
4931 list_for_each_entry(tmp, &conf->hold_list, lru) {
4932 if (conf->worker_cnt_per_group == 0 ||
4933 group == ANY_GROUP ||
4934 !cpu_online(tmp->cpu) ||
4935 cpu_to_group(tmp->cpu) == group) {
4942 conf->bypass_count -= conf->bypass_threshold;
4943 if (conf->bypass_count < 0)
4944 conf->bypass_count = 0;
4956 list_del_init(&sh->lru);
4957 BUG_ON(atomic_inc_return(&sh->count) != 1);
4961 struct raid5_plug_cb {
4962 struct blk_plug_cb cb;
4963 struct list_head list;
4964 struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS];
4967 static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
4969 struct raid5_plug_cb *cb = container_of(
4970 blk_cb, struct raid5_plug_cb, cb);
4971 struct stripe_head *sh;
4972 struct mddev *mddev = cb->cb.data;
4973 struct r5conf *conf = mddev->private;
4977 if (cb->list.next && !list_empty(&cb->list)) {
4978 spin_lock_irq(&conf->device_lock);
4979 while (!list_empty(&cb->list)) {
4980 sh = list_first_entry(&cb->list, struct stripe_head, lru);
4981 list_del_init(&sh->lru);
4983 * avoid race release_stripe_plug() sees
4984 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4985 * is still in our list
4987 smp_mb__before_atomic();
4988 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
4990 * STRIPE_ON_RELEASE_LIST could be set here. In that
4991 * case, the count is always > 1 here
4993 hash = sh->hash_lock_index;
4994 __release_stripe(conf, sh, &cb->temp_inactive_list[hash]);
4997 spin_unlock_irq(&conf->device_lock);
4999 release_inactive_stripe_list(conf, cb->temp_inactive_list,
5000 NR_STRIPE_HASH_LOCKS);
5002 trace_block_unplug(mddev->queue, cnt, !from_schedule);
5006 static void release_stripe_plug(struct mddev *mddev,
5007 struct stripe_head *sh)
5009 struct blk_plug_cb *blk_cb = blk_check_plugged(
5010 raid5_unplug, mddev,
5011 sizeof(struct raid5_plug_cb));
5012 struct raid5_plug_cb *cb;
5019 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
5021 if (cb->list.next == NULL) {
5023 INIT_LIST_HEAD(&cb->list);
5024 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5025 INIT_LIST_HEAD(cb->temp_inactive_list + i);
5028 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
5029 list_add_tail(&sh->lru, &cb->list);
5034 static void make_discard_request(struct mddev *mddev, struct bio *bi)
5036 struct r5conf *conf = mddev->private;
5037 sector_t logical_sector, last_sector;
5038 struct stripe_head *sh;
5042 if (mddev->reshape_position != MaxSector)
5043 /* Skip discard while reshape is happening */
5046 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5047 last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
5050 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5052 stripe_sectors = conf->chunk_sectors *
5053 (conf->raid_disks - conf->max_degraded);
5054 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
5056 sector_div(last_sector, stripe_sectors);
5058 logical_sector *= conf->chunk_sectors;
5059 last_sector *= conf->chunk_sectors;
5061 for (; logical_sector < last_sector;
5062 logical_sector += STRIPE_SECTORS) {
5066 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
5067 prepare_to_wait(&conf->wait_for_overlap, &w,
5068 TASK_UNINTERRUPTIBLE);
5069 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5070 if (test_bit(STRIPE_SYNCING, &sh->state)) {
5075 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
5076 spin_lock_irq(&sh->stripe_lock);
5077 for (d = 0; d < conf->raid_disks; d++) {
5078 if (d == sh->pd_idx || d == sh->qd_idx)
5080 if (sh->dev[d].towrite || sh->dev[d].toread) {
5081 set_bit(R5_Overlap, &sh->dev[d].flags);
5082 spin_unlock_irq(&sh->stripe_lock);
5088 set_bit(STRIPE_DISCARD, &sh->state);
5089 finish_wait(&conf->wait_for_overlap, &w);
5090 sh->overwrite_disks = 0;
5091 for (d = 0; d < conf->raid_disks; d++) {
5092 if (d == sh->pd_idx || d == sh->qd_idx)
5094 sh->dev[d].towrite = bi;
5095 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
5096 raid5_inc_bi_active_stripes(bi);
5097 sh->overwrite_disks++;
5099 spin_unlock_irq(&sh->stripe_lock);
5100 if (conf->mddev->bitmap) {
5102 d < conf->raid_disks - conf->max_degraded;
5104 bitmap_startwrite(mddev->bitmap,
5108 sh->bm_seq = conf->seq_flush + 1;
5109 set_bit(STRIPE_BIT_DELAY, &sh->state);
5112 set_bit(STRIPE_HANDLE, &sh->state);
5113 clear_bit(STRIPE_DELAYED, &sh->state);
5114 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5115 atomic_inc(&conf->preread_active_stripes);
5116 release_stripe_plug(mddev, sh);
5119 remaining = raid5_dec_bi_active_stripes(bi);
5120 if (remaining == 0) {
5121 md_write_end(mddev);
5126 static void make_request(struct mddev *mddev, struct bio * bi)
5128 struct r5conf *conf = mddev->private;
5130 sector_t new_sector;
5131 sector_t logical_sector, last_sector;
5132 struct stripe_head *sh;
5133 const int rw = bio_data_dir(bi);
5138 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
5139 md_flush_request(mddev, bi);
5143 md_write_start(mddev, bi);
5146 * If array is degraded, better not do chunk aligned read because
5147 * later we might have to read it again in order to reconstruct
5148 * data on failed drives.
5150 if (rw == READ && mddev->degraded == 0 &&
5151 mddev->reshape_position == MaxSector) {
5152 bi = chunk_aligned_read(mddev, bi);
5157 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
5158 make_discard_request(mddev, bi);
5162 logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
5163 last_sector = bio_end_sector(bi);
5165 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
5167 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
5168 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
5174 seq = read_seqcount_begin(&conf->gen_lock);
5177 prepare_to_wait(&conf->wait_for_overlap, &w,
5178 TASK_UNINTERRUPTIBLE);
5179 if (unlikely(conf->reshape_progress != MaxSector)) {
5180 /* spinlock is needed as reshape_progress may be
5181 * 64bit on a 32bit platform, and so it might be
5182 * possible to see a half-updated value
5183 * Of course reshape_progress could change after
5184 * the lock is dropped, so once we get a reference
5185 * to the stripe that we think it is, we will have
5188 spin_lock_irq(&conf->device_lock);
5189 if (mddev->reshape_backwards
5190 ? logical_sector < conf->reshape_progress
5191 : logical_sector >= conf->reshape_progress) {
5194 if (mddev->reshape_backwards
5195 ? logical_sector < conf->reshape_safe
5196 : logical_sector >= conf->reshape_safe) {
5197 spin_unlock_irq(&conf->device_lock);
5203 spin_unlock_irq(&conf->device_lock);
5206 new_sector = raid5_compute_sector(conf, logical_sector,
5209 pr_debug("raid456: make_request, sector %llu logical %llu\n",
5210 (unsigned long long)new_sector,
5211 (unsigned long long)logical_sector);
5213 sh = get_active_stripe(conf, new_sector, previous,
5214 (bi->bi_rw&RWA_MASK), 0);
5216 if (unlikely(previous)) {
5217 /* expansion might have moved on while waiting for a
5218 * stripe, so we must do the range check again.
5219 * Expansion could still move past after this
5220 * test, but as we are holding a reference to
5221 * 'sh', we know that if that happens,
5222 * STRIPE_EXPANDING will get set and the expansion
5223 * won't proceed until we finish with the stripe.
5226 spin_lock_irq(&conf->device_lock);
5227 if (mddev->reshape_backwards
5228 ? logical_sector >= conf->reshape_progress
5229 : logical_sector < conf->reshape_progress)
5230 /* mismatch, need to try again */
5232 spin_unlock_irq(&conf->device_lock);
5240 if (read_seqcount_retry(&conf->gen_lock, seq)) {
5241 /* Might have got the wrong stripe_head
5249 logical_sector >= mddev->suspend_lo &&
5250 logical_sector < mddev->suspend_hi) {
5252 /* As the suspend_* range is controlled by
5253 * userspace, we want an interruptible
5256 flush_signals(current);
5257 prepare_to_wait(&conf->wait_for_overlap,
5258 &w, TASK_INTERRUPTIBLE);
5259 if (logical_sector >= mddev->suspend_lo &&
5260 logical_sector < mddev->suspend_hi) {
5267 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
5268 !add_stripe_bio(sh, bi, dd_idx, rw, previous)) {
5269 /* Stripe is busy expanding or
5270 * add failed due to overlap. Flush everything
5273 md_wakeup_thread(mddev->thread);
5279 set_bit(STRIPE_HANDLE, &sh->state);
5280 clear_bit(STRIPE_DELAYED, &sh->state);
5281 if ((!sh->batch_head || sh == sh->batch_head) &&
5282 (bi->bi_rw & REQ_SYNC) &&
5283 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
5284 atomic_inc(&conf->preread_active_stripes);
5285 release_stripe_plug(mddev, sh);
5287 /* cannot get stripe for read-ahead, just give-up */
5288 bi->bi_error = -EIO;
5292 finish_wait(&conf->wait_for_overlap, &w);
5294 remaining = raid5_dec_bi_active_stripes(bi);
5295 if (remaining == 0) {
5298 md_write_end(mddev);
5300 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
5306 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
5308 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5310 /* reshaping is quite different to recovery/resync so it is
5311 * handled quite separately ... here.
5313 * On each call to sync_request, we gather one chunk worth of
5314 * destination stripes and flag them as expanding.
5315 * Then we find all the source stripes and request reads.
5316 * As the reads complete, handle_stripe will copy the data
5317 * into the destination stripe and release that stripe.
5319 struct r5conf *conf = mddev->private;
5320 struct stripe_head *sh;
5321 sector_t first_sector, last_sector;
5322 int raid_disks = conf->previous_raid_disks;
5323 int data_disks = raid_disks - conf->max_degraded;
5324 int new_data_disks = conf->raid_disks - conf->max_degraded;
5327 sector_t writepos, readpos, safepos;
5328 sector_t stripe_addr;
5329 int reshape_sectors;
5330 struct list_head stripes;
5333 if (sector_nr == 0) {
5334 /* If restarting in the middle, skip the initial sectors */
5335 if (mddev->reshape_backwards &&
5336 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
5337 sector_nr = raid5_size(mddev, 0, 0)
5338 - conf->reshape_progress;
5339 } else if (mddev->reshape_backwards &&
5340 conf->reshape_progress == MaxSector) {
5341 /* shouldn't happen, but just in case, finish up.*/
5342 sector_nr = MaxSector;
5343 } else if (!mddev->reshape_backwards &&
5344 conf->reshape_progress > 0)
5345 sector_nr = conf->reshape_progress;
5346 sector_div(sector_nr, new_data_disks);
5348 mddev->curr_resync_completed = sector_nr;
5349 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5356 /* We need to process a full chunk at a time.
5357 * If old and new chunk sizes differ, we need to process the
5361 reshape_sectors = max(conf->chunk_sectors, conf->prev_chunk_sectors);
5363 /* We update the metadata at least every 10 seconds, or when
5364 * the data about to be copied would over-write the source of
5365 * the data at the front of the range. i.e. one new_stripe
5366 * along from reshape_progress new_maps to after where
5367 * reshape_safe old_maps to
5369 writepos = conf->reshape_progress;
5370 sector_div(writepos, new_data_disks);
5371 readpos = conf->reshape_progress;
5372 sector_div(readpos, data_disks);
5373 safepos = conf->reshape_safe;
5374 sector_div(safepos, data_disks);
5375 if (mddev->reshape_backwards) {
5376 BUG_ON(writepos < reshape_sectors);
5377 writepos -= reshape_sectors;
5378 readpos += reshape_sectors;
5379 safepos += reshape_sectors;
5381 writepos += reshape_sectors;
5382 /* readpos and safepos are worst-case calculations.
5383 * A negative number is overly pessimistic, and causes
5384 * obvious problems for unsigned storage. So clip to 0.
5386 readpos -= min_t(sector_t, reshape_sectors, readpos);
5387 safepos -= min_t(sector_t, reshape_sectors, safepos);
5390 /* Having calculated the 'writepos' possibly use it
5391 * to set 'stripe_addr' which is where we will write to.
5393 if (mddev->reshape_backwards) {
5394 BUG_ON(conf->reshape_progress == 0);
5395 stripe_addr = writepos;
5396 BUG_ON((mddev->dev_sectors &
5397 ~((sector_t)reshape_sectors - 1))
5398 - reshape_sectors - stripe_addr
5401 BUG_ON(writepos != sector_nr + reshape_sectors);
5402 stripe_addr = sector_nr;
5405 /* 'writepos' is the most advanced device address we might write.
5406 * 'readpos' is the least advanced device address we might read.
5407 * 'safepos' is the least address recorded in the metadata as having
5409 * If there is a min_offset_diff, these are adjusted either by
5410 * increasing the safepos/readpos if diff is negative, or
5411 * increasing writepos if diff is positive.
5412 * If 'readpos' is then behind 'writepos', there is no way that we can
5413 * ensure safety in the face of a crash - that must be done by userspace
5414 * making a backup of the data. So in that case there is no particular
5415 * rush to update metadata.
5416 * Otherwise if 'safepos' is behind 'writepos', then we really need to
5417 * update the metadata to advance 'safepos' to match 'readpos' so that
5418 * we can be safe in the event of a crash.
5419 * So we insist on updating metadata if safepos is behind writepos and
5420 * readpos is beyond writepos.
5421 * In any case, update the metadata every 10 seconds.
5422 * Maybe that number should be configurable, but I'm not sure it is
5423 * worth it.... maybe it could be a multiple of safemode_delay???
5425 if (conf->min_offset_diff < 0) {
5426 safepos += -conf->min_offset_diff;
5427 readpos += -conf->min_offset_diff;
5429 writepos += conf->min_offset_diff;
5431 if ((mddev->reshape_backwards
5432 ? (safepos > writepos && readpos < writepos)
5433 : (safepos < writepos && readpos > writepos)) ||
5434 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
5435 /* Cannot proceed until we've updated the superblock... */
5436 wait_event(conf->wait_for_overlap,
5437 atomic_read(&conf->reshape_stripes)==0
5438 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5439 if (atomic_read(&conf->reshape_stripes) != 0)
5441 mddev->reshape_position = conf->reshape_progress;
5442 mddev->curr_resync_completed = sector_nr;
5443 conf->reshape_checkpoint = jiffies;
5444 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5445 md_wakeup_thread(mddev->thread);
5446 wait_event(mddev->sb_wait, mddev->flags == 0 ||
5447 test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5448 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5450 spin_lock_irq(&conf->device_lock);
5451 conf->reshape_safe = mddev->reshape_position;
5452 spin_unlock_irq(&conf->device_lock);
5453 wake_up(&conf->wait_for_overlap);
5454 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5457 INIT_LIST_HEAD(&stripes);
5458 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
5460 int skipped_disk = 0;
5461 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
5462 set_bit(STRIPE_EXPANDING, &sh->state);
5463 atomic_inc(&conf->reshape_stripes);
5464 /* If any of this stripe is beyond the end of the old
5465 * array, then we need to zero those blocks
5467 for (j=sh->disks; j--;) {
5469 if (j == sh->pd_idx)
5471 if (conf->level == 6 &&
5474 s = compute_blocknr(sh, j, 0);
5475 if (s < raid5_size(mddev, 0, 0)) {
5479 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
5480 set_bit(R5_Expanded, &sh->dev[j].flags);
5481 set_bit(R5_UPTODATE, &sh->dev[j].flags);
5483 if (!skipped_disk) {
5484 set_bit(STRIPE_EXPAND_READY, &sh->state);
5485 set_bit(STRIPE_HANDLE, &sh->state);
5487 list_add(&sh->lru, &stripes);
5489 spin_lock_irq(&conf->device_lock);
5490 if (mddev->reshape_backwards)
5491 conf->reshape_progress -= reshape_sectors * new_data_disks;
5493 conf->reshape_progress += reshape_sectors * new_data_disks;
5494 spin_unlock_irq(&conf->device_lock);
5495 /* Ok, those stripe are ready. We can start scheduling
5496 * reads on the source stripes.
5497 * The source stripes are determined by mapping the first and last
5498 * block on the destination stripes.
5501 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
5504 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
5505 * new_data_disks - 1),
5507 if (last_sector >= mddev->dev_sectors)
5508 last_sector = mddev->dev_sectors - 1;
5509 while (first_sector <= last_sector) {
5510 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
5511 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
5512 set_bit(STRIPE_HANDLE, &sh->state);
5514 first_sector += STRIPE_SECTORS;
5516 /* Now that the sources are clearly marked, we can release
5517 * the destination stripes
5519 while (!list_empty(&stripes)) {
5520 sh = list_entry(stripes.next, struct stripe_head, lru);
5521 list_del_init(&sh->lru);
5524 /* If this takes us to the resync_max point where we have to pause,
5525 * then we need to write out the superblock.
5527 sector_nr += reshape_sectors;
5528 retn = reshape_sectors;
5530 if (mddev->curr_resync_completed > mddev->resync_max ||
5531 (sector_nr - mddev->curr_resync_completed) * 2
5532 >= mddev->resync_max - mddev->curr_resync_completed) {
5533 /* Cannot proceed until we've updated the superblock... */
5534 wait_event(conf->wait_for_overlap,
5535 atomic_read(&conf->reshape_stripes) == 0
5536 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5537 if (atomic_read(&conf->reshape_stripes) != 0)
5539 mddev->reshape_position = conf->reshape_progress;
5540 mddev->curr_resync_completed = sector_nr;
5541 conf->reshape_checkpoint = jiffies;
5542 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5543 md_wakeup_thread(mddev->thread);
5544 wait_event(mddev->sb_wait,
5545 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
5546 || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
5547 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
5549 spin_lock_irq(&conf->device_lock);
5550 conf->reshape_safe = mddev->reshape_position;
5551 spin_unlock_irq(&conf->device_lock);
5552 wake_up(&conf->wait_for_overlap);
5553 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
5559 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
5561 struct r5conf *conf = mddev->private;
5562 struct stripe_head *sh;
5563 sector_t max_sector = mddev->dev_sectors;
5564 sector_t sync_blocks;
5565 int still_degraded = 0;
5568 if (sector_nr >= max_sector) {
5569 /* just being told to finish up .. nothing much to do */
5571 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
5576 if (mddev->curr_resync < max_sector) /* aborted */
5577 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
5579 else /* completed sync */
5581 bitmap_close_sync(mddev->bitmap);
5586 /* Allow raid5_quiesce to complete */
5587 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
5589 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
5590 return reshape_request(mddev, sector_nr, skipped);
5592 /* No need to check resync_max as we never do more than one
5593 * stripe, and as resync_max will always be on a chunk boundary,
5594 * if the check in md_do_sync didn't fire, there is no chance
5595 * of overstepping resync_max here
5598 /* if there is too many failed drives and we are trying
5599 * to resync, then assert that we are finished, because there is
5600 * nothing we can do.
5602 if (mddev->degraded >= conf->max_degraded &&
5603 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
5604 sector_t rv = mddev->dev_sectors - sector_nr;
5608 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
5610 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
5611 sync_blocks >= STRIPE_SECTORS) {
5612 /* we can skip this block, and probably more */
5613 sync_blocks /= STRIPE_SECTORS;
5615 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
5618 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
5620 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
5622 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
5623 /* make sure we don't swamp the stripe cache if someone else
5624 * is trying to get access
5626 schedule_timeout_uninterruptible(1);
5628 /* Need to check if array will still be degraded after recovery/resync
5629 * Note in case of > 1 drive failures it's possible we're rebuilding
5630 * one drive while leaving another faulty drive in array.
5633 for (i = 0; i < conf->raid_disks; i++) {
5634 struct md_rdev *rdev = ACCESS_ONCE(conf->disks[i].rdev);
5636 if (rdev == NULL || test_bit(Faulty, &rdev->flags))
5641 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
5643 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
5644 set_bit(STRIPE_HANDLE, &sh->state);
5648 return STRIPE_SECTORS;
5651 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
5653 /* We may not be able to submit a whole bio at once as there
5654 * may not be enough stripe_heads available.
5655 * We cannot pre-allocate enough stripe_heads as we may need
5656 * more than exist in the cache (if we allow ever large chunks).
5657 * So we do one stripe head at a time and record in
5658 * ->bi_hw_segments how many have been done.
5660 * We *know* that this entire raid_bio is in one chunk, so
5661 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
5663 struct stripe_head *sh;
5665 sector_t sector, logical_sector, last_sector;
5670 logical_sector = raid_bio->bi_iter.bi_sector &
5671 ~((sector_t)STRIPE_SECTORS-1);
5672 sector = raid5_compute_sector(conf, logical_sector,
5674 last_sector = bio_end_sector(raid_bio);
5676 for (; logical_sector < last_sector;
5677 logical_sector += STRIPE_SECTORS,
5678 sector += STRIPE_SECTORS,
5681 if (scnt < raid5_bi_processed_stripes(raid_bio))
5682 /* already done this stripe */
5685 sh = get_active_stripe(conf, sector, 0, 1, 1);
5688 /* failed to get a stripe - must wait */
5689 raid5_set_bi_processed_stripes(raid_bio, scnt);
5690 conf->retry_read_aligned = raid_bio;
5694 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) {
5696 raid5_set_bi_processed_stripes(raid_bio, scnt);
5697 conf->retry_read_aligned = raid_bio;
5701 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
5706 remaining = raid5_dec_bi_active_stripes(raid_bio);
5707 if (remaining == 0) {
5708 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
5710 bio_endio(raid_bio);
5712 if (atomic_dec_and_test(&conf->active_aligned_reads))
5713 wake_up(&conf->wait_for_quiescent);
5717 static int handle_active_stripes(struct r5conf *conf, int group,
5718 struct r5worker *worker,
5719 struct list_head *temp_inactive_list)
5721 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
5722 int i, batch_size = 0, hash;
5723 bool release_inactive = false;
5725 while (batch_size < MAX_STRIPE_BATCH &&
5726 (sh = __get_priority_stripe(conf, group)) != NULL)
5727 batch[batch_size++] = sh;
5729 if (batch_size == 0) {
5730 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
5731 if (!list_empty(temp_inactive_list + i))
5733 if (i == NR_STRIPE_HASH_LOCKS)
5735 release_inactive = true;
5737 spin_unlock_irq(&conf->device_lock);
5739 release_inactive_stripe_list(conf, temp_inactive_list,
5740 NR_STRIPE_HASH_LOCKS);
5742 if (release_inactive) {
5743 spin_lock_irq(&conf->device_lock);
5747 for (i = 0; i < batch_size; i++)
5748 handle_stripe(batch[i]);
5752 spin_lock_irq(&conf->device_lock);
5753 for (i = 0; i < batch_size; i++) {
5754 hash = batch[i]->hash_lock_index;
5755 __release_stripe(conf, batch[i], &temp_inactive_list[hash]);
5760 static void raid5_do_work(struct work_struct *work)
5762 struct r5worker *worker = container_of(work, struct r5worker, work);
5763 struct r5worker_group *group = worker->group;
5764 struct r5conf *conf = group->conf;
5765 int group_id = group - conf->worker_groups;
5767 struct blk_plug plug;
5769 pr_debug("+++ raid5worker active\n");
5771 blk_start_plug(&plug);
5773 spin_lock_irq(&conf->device_lock);
5775 int batch_size, released;
5777 released = release_stripe_list(conf, worker->temp_inactive_list);
5779 batch_size = handle_active_stripes(conf, group_id, worker,
5780 worker->temp_inactive_list);
5781 worker->working = false;
5782 if (!batch_size && !released)
5784 handled += batch_size;
5786 pr_debug("%d stripes handled\n", handled);
5788 spin_unlock_irq(&conf->device_lock);
5789 blk_finish_plug(&plug);
5791 pr_debug("--- raid5worker inactive\n");
5795 * This is our raid5 kernel thread.
5797 * We scan the hash table for stripes which can be handled now.
5798 * During the scan, completed stripes are saved for us by the interrupt
5799 * handler, so that they will not have to wait for our next wakeup.
5801 static void raid5d(struct md_thread *thread)
5803 struct mddev *mddev = thread->mddev;
5804 struct r5conf *conf = mddev->private;
5806 struct blk_plug plug;
5808 pr_debug("+++ raid5d active\n");
5810 md_check_recovery(mddev);
5812 if (!bio_list_empty(&conf->return_bi) &&
5813 !test_bit(MD_CHANGE_PENDING, &mddev->flags)) {
5814 struct bio_list tmp = BIO_EMPTY_LIST;
5815 spin_lock_irq(&conf->device_lock);
5816 if (!test_bit(MD_CHANGE_PENDING, &mddev->flags)) {
5817 bio_list_merge(&tmp, &conf->return_bi);
5818 bio_list_init(&conf->return_bi);
5820 spin_unlock_irq(&conf->device_lock);
5824 blk_start_plug(&plug);
5826 spin_lock_irq(&conf->device_lock);
5829 int batch_size, released;
5831 released = release_stripe_list(conf, conf->temp_inactive_list);
5833 clear_bit(R5_DID_ALLOC, &conf->cache_state);
5836 !list_empty(&conf->bitmap_list)) {
5837 /* Now is a good time to flush some bitmap updates */
5839 spin_unlock_irq(&conf->device_lock);
5840 bitmap_unplug(mddev->bitmap);
5841 spin_lock_irq(&conf->device_lock);
5842 conf->seq_write = conf->seq_flush;
5843 activate_bit_delay(conf, conf->temp_inactive_list);
5845 raid5_activate_delayed(conf);
5847 while ((bio = remove_bio_from_retry(conf))) {
5849 spin_unlock_irq(&conf->device_lock);
5850 ok = retry_aligned_read(conf, bio);
5851 spin_lock_irq(&conf->device_lock);
5857 batch_size = handle_active_stripes(conf, ANY_GROUP, NULL,
5858 conf->temp_inactive_list);
5859 if (!batch_size && !released)
5861 handled += batch_size;
5863 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
5864 spin_unlock_irq(&conf->device_lock);
5865 md_check_recovery(mddev);
5866 spin_lock_irq(&conf->device_lock);
5869 pr_debug("%d stripes handled\n", handled);
5871 spin_unlock_irq(&conf->device_lock);
5872 if (test_and_clear_bit(R5_ALLOC_MORE, &conf->cache_state) &&
5873 mutex_trylock(&conf->cache_size_mutex)) {
5874 grow_one_stripe(conf, __GFP_NOWARN);
5875 /* Set flag even if allocation failed. This helps
5876 * slow down allocation requests when mem is short
5878 set_bit(R5_DID_ALLOC, &conf->cache_state);
5879 mutex_unlock(&conf->cache_size_mutex);
5882 async_tx_issue_pending_all();
5883 blk_finish_plug(&plug);
5885 pr_debug("--- raid5d inactive\n");
5889 raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
5891 struct r5conf *conf;
5893 spin_lock(&mddev->lock);
5894 conf = mddev->private;
5896 ret = sprintf(page, "%d\n", conf->min_nr_stripes);
5897 spin_unlock(&mddev->lock);
5902 raid5_set_cache_size(struct mddev *mddev, int size)
5904 struct r5conf *conf = mddev->private;
5907 if (size <= 16 || size > 32768)
5910 conf->min_nr_stripes = size;
5911 mutex_lock(&conf->cache_size_mutex);
5912 while (size < conf->max_nr_stripes &&
5913 drop_one_stripe(conf))
5915 mutex_unlock(&conf->cache_size_mutex);
5918 err = md_allow_write(mddev);
5922 mutex_lock(&conf->cache_size_mutex);
5923 while (size > conf->max_nr_stripes)
5924 if (!grow_one_stripe(conf, GFP_KERNEL))
5926 mutex_unlock(&conf->cache_size_mutex);
5930 EXPORT_SYMBOL(raid5_set_cache_size);
5933 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
5935 struct r5conf *conf;
5939 if (len >= PAGE_SIZE)
5941 if (kstrtoul(page, 10, &new))
5943 err = mddev_lock(mddev);
5946 conf = mddev->private;
5950 err = raid5_set_cache_size(mddev, new);
5951 mddev_unlock(mddev);
5956 static struct md_sysfs_entry
5957 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
5958 raid5_show_stripe_cache_size,
5959 raid5_store_stripe_cache_size);
5962 raid5_show_rmw_level(struct mddev *mddev, char *page)
5964 struct r5conf *conf = mddev->private;
5966 return sprintf(page, "%d\n", conf->rmw_level);
5972 raid5_store_rmw_level(struct mddev *mddev, const char *page, size_t len)
5974 struct r5conf *conf = mddev->private;
5980 if (len >= PAGE_SIZE)
5983 if (kstrtoul(page, 10, &new))
5986 if (new != PARITY_DISABLE_RMW && !raid6_call.xor_syndrome)
5989 if (new != PARITY_DISABLE_RMW &&
5990 new != PARITY_ENABLE_RMW &&
5991 new != PARITY_PREFER_RMW)
5994 conf->rmw_level = new;
5998 static struct md_sysfs_entry
5999 raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR,
6000 raid5_show_rmw_level,
6001 raid5_store_rmw_level);
6005 raid5_show_preread_threshold(struct mddev *mddev, char *page)
6007 struct r5conf *conf;
6009 spin_lock(&mddev->lock);
6010 conf = mddev->private;
6012 ret = sprintf(page, "%d\n", conf->bypass_threshold);
6013 spin_unlock(&mddev->lock);
6018 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
6020 struct r5conf *conf;
6024 if (len >= PAGE_SIZE)
6026 if (kstrtoul(page, 10, &new))
6029 err = mddev_lock(mddev);
6032 conf = mddev->private;
6035 else if (new > conf->min_nr_stripes)
6038 conf->bypass_threshold = new;
6039 mddev_unlock(mddev);
6043 static struct md_sysfs_entry
6044 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
6046 raid5_show_preread_threshold,
6047 raid5_store_preread_threshold);
6050 raid5_show_skip_copy(struct mddev *mddev, char *page)
6052 struct r5conf *conf;
6054 spin_lock(&mddev->lock);
6055 conf = mddev->private;
6057 ret = sprintf(page, "%d\n", conf->skip_copy);
6058 spin_unlock(&mddev->lock);
6063 raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len)
6065 struct r5conf *conf;
6069 if (len >= PAGE_SIZE)
6071 if (kstrtoul(page, 10, &new))
6075 err = mddev_lock(mddev);
6078 conf = mddev->private;
6081 else if (new != conf->skip_copy) {
6082 mddev_suspend(mddev);
6083 conf->skip_copy = new;
6085 mddev->queue->backing_dev_info.capabilities |=
6086 BDI_CAP_STABLE_WRITES;
6088 mddev->queue->backing_dev_info.capabilities &=
6089 ~BDI_CAP_STABLE_WRITES;
6090 mddev_resume(mddev);
6092 mddev_unlock(mddev);
6096 static struct md_sysfs_entry
6097 raid5_skip_copy = __ATTR(skip_copy, S_IRUGO | S_IWUSR,
6098 raid5_show_skip_copy,
6099 raid5_store_skip_copy);
6102 stripe_cache_active_show(struct mddev *mddev, char *page)
6104 struct r5conf *conf = mddev->private;
6106 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
6111 static struct md_sysfs_entry
6112 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
6115 raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
6117 struct r5conf *conf;
6119 spin_lock(&mddev->lock);
6120 conf = mddev->private;
6122 ret = sprintf(page, "%d\n", conf->worker_cnt_per_group);
6123 spin_unlock(&mddev->lock);
6127 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6129 int *worker_cnt_per_group,
6130 struct r5worker_group **worker_groups);
6132 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
6134 struct r5conf *conf;
6137 struct r5worker_group *new_groups, *old_groups;
6138 int group_cnt, worker_cnt_per_group;
6140 if (len >= PAGE_SIZE)
6142 if (kstrtoul(page, 10, &new))
6145 err = mddev_lock(mddev);
6148 conf = mddev->private;
6151 else if (new != conf->worker_cnt_per_group) {
6152 mddev_suspend(mddev);
6154 old_groups = conf->worker_groups;
6156 flush_workqueue(raid5_wq);
6158 err = alloc_thread_groups(conf, new,
6159 &group_cnt, &worker_cnt_per_group,
6162 spin_lock_irq(&conf->device_lock);
6163 conf->group_cnt = group_cnt;
6164 conf->worker_cnt_per_group = worker_cnt_per_group;
6165 conf->worker_groups = new_groups;
6166 spin_unlock_irq(&conf->device_lock);
6169 kfree(old_groups[0].workers);
6172 mddev_resume(mddev);
6174 mddev_unlock(mddev);
6179 static struct md_sysfs_entry
6180 raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
6181 raid5_show_group_thread_cnt,
6182 raid5_store_group_thread_cnt);
6184 static struct attribute *raid5_attrs[] = {
6185 &raid5_stripecache_size.attr,
6186 &raid5_stripecache_active.attr,
6187 &raid5_preread_bypass_threshold.attr,
6188 &raid5_group_thread_cnt.attr,
6189 &raid5_skip_copy.attr,
6190 &raid5_rmw_level.attr,
6193 static struct attribute_group raid5_attrs_group = {
6195 .attrs = raid5_attrs,
6198 static int alloc_thread_groups(struct r5conf *conf, int cnt,
6200 int *worker_cnt_per_group,
6201 struct r5worker_group **worker_groups)
6205 struct r5worker *workers;
6207 *worker_cnt_per_group = cnt;
6210 *worker_groups = NULL;
6213 *group_cnt = num_possible_nodes();
6214 size = sizeof(struct r5worker) * cnt;
6215 workers = kzalloc(size * *group_cnt, GFP_NOIO);
6216 *worker_groups = kzalloc(sizeof(struct r5worker_group) *
6217 *group_cnt, GFP_NOIO);
6218 if (!*worker_groups || !workers) {
6220 kfree(*worker_groups);
6224 for (i = 0; i < *group_cnt; i++) {
6225 struct r5worker_group *group;
6227 group = &(*worker_groups)[i];
6228 INIT_LIST_HEAD(&group->handle_list);
6230 group->workers = workers + i * cnt;
6232 for (j = 0; j < cnt; j++) {
6233 struct r5worker *worker = group->workers + j;
6234 worker->group = group;
6235 INIT_WORK(&worker->work, raid5_do_work);
6237 for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++)
6238 INIT_LIST_HEAD(worker->temp_inactive_list + k);
6245 static void free_thread_groups(struct r5conf *conf)
6247 if (conf->worker_groups)
6248 kfree(conf->worker_groups[0].workers);
6249 kfree(conf->worker_groups);
6250 conf->worker_groups = NULL;
6254 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
6256 struct r5conf *conf = mddev->private;
6259 sectors = mddev->dev_sectors;
6261 /* size is defined by the smallest of previous and new size */
6262 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
6264 sectors &= ~((sector_t)conf->chunk_sectors - 1);
6265 sectors &= ~((sector_t)conf->prev_chunk_sectors - 1);
6266 return sectors * (raid_disks - conf->max_degraded);
6269 static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6271 safe_put_page(percpu->spare_page);
6272 if (percpu->scribble)
6273 flex_array_free(percpu->scribble);
6274 percpu->spare_page = NULL;
6275 percpu->scribble = NULL;
6278 static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
6280 if (conf->level == 6 && !percpu->spare_page)
6281 percpu->spare_page = alloc_page(GFP_KERNEL);
6282 if (!percpu->scribble)
6283 percpu->scribble = scribble_alloc(max(conf->raid_disks,
6284 conf->previous_raid_disks),
6285 max(conf->chunk_sectors,
6286 conf->prev_chunk_sectors)
6290 if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
6291 free_scratch_buffer(conf, percpu);
6298 static void raid5_free_percpu(struct r5conf *conf)
6305 #ifdef CONFIG_HOTPLUG_CPU
6306 unregister_cpu_notifier(&conf->cpu_notify);
6310 for_each_possible_cpu(cpu)
6311 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6314 free_percpu(conf->percpu);
6317 static void free_conf(struct r5conf *conf)
6319 if (conf->shrinker.seeks)
6320 unregister_shrinker(&conf->shrinker);
6321 free_thread_groups(conf);
6322 shrink_stripes(conf);
6323 raid5_free_percpu(conf);
6325 kfree(conf->stripe_hashtbl);
6329 #ifdef CONFIG_HOTPLUG_CPU
6330 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
6333 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
6334 long cpu = (long)hcpu;
6335 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
6338 case CPU_UP_PREPARE:
6339 case CPU_UP_PREPARE_FROZEN:
6340 if (alloc_scratch_buffer(conf, percpu)) {
6341 pr_err("%s: failed memory allocation for cpu%ld\n",
6343 return notifier_from_errno(-ENOMEM);
6347 case CPU_DEAD_FROZEN:
6348 free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6357 static int raid5_alloc_percpu(struct r5conf *conf)
6362 conf->percpu = alloc_percpu(struct raid5_percpu);
6366 #ifdef CONFIG_HOTPLUG_CPU
6367 conf->cpu_notify.notifier_call = raid456_cpu_notify;
6368 conf->cpu_notify.priority = 0;
6369 err = register_cpu_notifier(&conf->cpu_notify);
6375 for_each_present_cpu(cpu) {
6376 err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
6378 pr_err("%s: failed memory allocation for cpu%ld\n",
6388 static unsigned long raid5_cache_scan(struct shrinker *shrink,
6389 struct shrink_control *sc)
6391 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6392 unsigned long ret = SHRINK_STOP;
6394 if (mutex_trylock(&conf->cache_size_mutex)) {
6396 while (ret < sc->nr_to_scan &&
6397 conf->max_nr_stripes > conf->min_nr_stripes) {
6398 if (drop_one_stripe(conf) == 0) {
6404 mutex_unlock(&conf->cache_size_mutex);
6409 static unsigned long raid5_cache_count(struct shrinker *shrink,
6410 struct shrink_control *sc)
6412 struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
6414 if (conf->max_nr_stripes < conf->min_nr_stripes)
6415 /* unlikely, but not impossible */
6417 return conf->max_nr_stripes - conf->min_nr_stripes;
6420 static struct r5conf *setup_conf(struct mddev *mddev)
6422 struct r5conf *conf;
6423 int raid_disk, memory, max_disks;
6424 struct md_rdev *rdev;
6425 struct disk_info *disk;
6428 int group_cnt, worker_cnt_per_group;
6429 struct r5worker_group *new_group;
6431 if (mddev->new_level != 5
6432 && mddev->new_level != 4
6433 && mddev->new_level != 6) {
6434 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
6435 mdname(mddev), mddev->new_level);
6436 return ERR_PTR(-EIO);
6438 if ((mddev->new_level == 5
6439 && !algorithm_valid_raid5(mddev->new_layout)) ||
6440 (mddev->new_level == 6
6441 && !algorithm_valid_raid6(mddev->new_layout))) {
6442 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
6443 mdname(mddev), mddev->new_layout);
6444 return ERR_PTR(-EIO);
6446 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
6447 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
6448 mdname(mddev), mddev->raid_disks);
6449 return ERR_PTR(-EINVAL);
6452 if (!mddev->new_chunk_sectors ||
6453 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
6454 !is_power_of_2(mddev->new_chunk_sectors)) {
6455 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
6456 mdname(mddev), mddev->new_chunk_sectors << 9);
6457 return ERR_PTR(-EINVAL);
6460 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
6463 /* Don't enable multi-threading by default*/
6464 if (!alloc_thread_groups(conf, 0, &group_cnt, &worker_cnt_per_group,
6466 conf->group_cnt = group_cnt;
6467 conf->worker_cnt_per_group = worker_cnt_per_group;
6468 conf->worker_groups = new_group;
6471 spin_lock_init(&conf->device_lock);
6472 seqcount_init(&conf->gen_lock);
6473 mutex_init(&conf->cache_size_mutex);
6474 init_waitqueue_head(&conf->wait_for_quiescent);
6475 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) {
6476 init_waitqueue_head(&conf->wait_for_stripe[i]);
6478 init_waitqueue_head(&conf->wait_for_overlap);
6479 INIT_LIST_HEAD(&conf->handle_list);
6480 INIT_LIST_HEAD(&conf->hold_list);
6481 INIT_LIST_HEAD(&conf->delayed_list);
6482 INIT_LIST_HEAD(&conf->bitmap_list);
6483 bio_list_init(&conf->return_bi);
6484 init_llist_head(&conf->released_stripes);
6485 atomic_set(&conf->active_stripes, 0);
6486 atomic_set(&conf->preread_active_stripes, 0);
6487 atomic_set(&conf->active_aligned_reads, 0);
6488 conf->bypass_threshold = BYPASS_THRESHOLD;
6489 conf->recovery_disabled = mddev->recovery_disabled - 1;
6491 conf->raid_disks = mddev->raid_disks;
6492 if (mddev->reshape_position == MaxSector)
6493 conf->previous_raid_disks = mddev->raid_disks;
6495 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
6496 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
6498 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
6503 conf->mddev = mddev;
6505 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
6508 /* We init hash_locks[0] separately to that it can be used
6509 * as the reference lock in the spin_lock_nest_lock() call
6510 * in lock_all_device_hash_locks_irq in order to convince
6511 * lockdep that we know what we are doing.
6513 spin_lock_init(conf->hash_locks);
6514 for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
6515 spin_lock_init(conf->hash_locks + i);
6517 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6518 INIT_LIST_HEAD(conf->inactive_list + i);
6520 for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
6521 INIT_LIST_HEAD(conf->temp_inactive_list + i);
6523 conf->level = mddev->new_level;
6524 conf->chunk_sectors = mddev->new_chunk_sectors;
6525 if (raid5_alloc_percpu(conf) != 0)
6528 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
6530 rdev_for_each(rdev, mddev) {
6531 raid_disk = rdev->raid_disk;
6532 if (raid_disk >= max_disks
6535 disk = conf->disks + raid_disk;
6537 if (test_bit(Replacement, &rdev->flags)) {
6538 if (disk->replacement)
6540 disk->replacement = rdev;
6547 if (test_bit(In_sync, &rdev->flags)) {
6548 char b[BDEVNAME_SIZE];
6549 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
6551 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
6552 } else if (rdev->saved_raid_disk != raid_disk)
6553 /* Cannot rely on bitmap to complete recovery */
6557 conf->level = mddev->new_level;
6558 if (conf->level == 6) {
6559 conf->max_degraded = 2;
6560 if (raid6_call.xor_syndrome)
6561 conf->rmw_level = PARITY_ENABLE_RMW;
6563 conf->rmw_level = PARITY_DISABLE_RMW;
6565 conf->max_degraded = 1;
6566 conf->rmw_level = PARITY_ENABLE_RMW;
6568 conf->algorithm = mddev->new_layout;
6569 conf->reshape_progress = mddev->reshape_position;
6570 if (conf->reshape_progress != MaxSector) {
6571 conf->prev_chunk_sectors = mddev->chunk_sectors;
6572 conf->prev_algo = mddev->layout;
6574 conf->prev_chunk_sectors = conf->chunk_sectors;
6575 conf->prev_algo = conf->algorithm;
6578 conf->min_nr_stripes = NR_STRIPES;
6579 memory = conf->min_nr_stripes * (sizeof(struct stripe_head) +
6580 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
6581 atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
6582 if (grow_stripes(conf, conf->min_nr_stripes)) {
6584 "md/raid:%s: couldn't allocate %dkB for buffers\n",
6585 mdname(mddev), memory);
6588 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
6589 mdname(mddev), memory);
6591 * Losing a stripe head costs more than the time to refill it,
6592 * it reduces the queue depth and so can hurt throughput.
6593 * So set it rather large, scaled by number of devices.
6595 conf->shrinker.seeks = DEFAULT_SEEKS * conf->raid_disks * 4;
6596 conf->shrinker.scan_objects = raid5_cache_scan;
6597 conf->shrinker.count_objects = raid5_cache_count;
6598 conf->shrinker.batch = 128;
6599 conf->shrinker.flags = 0;
6600 register_shrinker(&conf->shrinker);
6602 sprintf(pers_name, "raid%d", mddev->new_level);
6603 conf->thread = md_register_thread(raid5d, mddev, pers_name);
6604 if (!conf->thread) {
6606 "md/raid:%s: couldn't allocate thread.\n",
6616 return ERR_PTR(-EIO);
6618 return ERR_PTR(-ENOMEM);
6621 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
6624 case ALGORITHM_PARITY_0:
6625 if (raid_disk < max_degraded)
6628 case ALGORITHM_PARITY_N:
6629 if (raid_disk >= raid_disks - max_degraded)
6632 case ALGORITHM_PARITY_0_6:
6633 if (raid_disk == 0 ||
6634 raid_disk == raid_disks - 1)
6637 case ALGORITHM_LEFT_ASYMMETRIC_6:
6638 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6639 case ALGORITHM_LEFT_SYMMETRIC_6:
6640 case ALGORITHM_RIGHT_SYMMETRIC_6:
6641 if (raid_disk == raid_disks - 1)
6647 static int run(struct mddev *mddev)
6649 struct r5conf *conf;
6650 int working_disks = 0;
6651 int dirty_parity_disks = 0;
6652 struct md_rdev *rdev;
6653 sector_t reshape_offset = 0;
6655 long long min_offset_diff = 0;
6658 if (mddev->recovery_cp != MaxSector)
6659 printk(KERN_NOTICE "md/raid:%s: not clean"
6660 " -- starting background reconstruction\n",
6663 rdev_for_each(rdev, mddev) {
6665 if (rdev->raid_disk < 0)
6667 diff = (rdev->new_data_offset - rdev->data_offset);
6669 min_offset_diff = diff;
6671 } else if (mddev->reshape_backwards &&
6672 diff < min_offset_diff)
6673 min_offset_diff = diff;
6674 else if (!mddev->reshape_backwards &&
6675 diff > min_offset_diff)
6676 min_offset_diff = diff;
6679 if (mddev->reshape_position != MaxSector) {
6680 /* Check that we can continue the reshape.
6681 * Difficulties arise if the stripe we would write to
6682 * next is at or after the stripe we would read from next.
6683 * For a reshape that changes the number of devices, this
6684 * is only possible for a very short time, and mdadm makes
6685 * sure that time appears to have past before assembling
6686 * the array. So we fail if that time hasn't passed.
6687 * For a reshape that keeps the number of devices the same
6688 * mdadm must be monitoring the reshape can keeping the
6689 * critical areas read-only and backed up. It will start
6690 * the array in read-only mode, so we check for that.
6692 sector_t here_new, here_old;
6694 int max_degraded = (mddev->level == 6 ? 2 : 1);
6698 if (mddev->new_level != mddev->level) {
6699 printk(KERN_ERR "md/raid:%s: unsupported reshape "
6700 "required - aborting.\n",
6704 old_disks = mddev->raid_disks - mddev->delta_disks;
6705 /* reshape_position must be on a new-stripe boundary, and one
6706 * further up in new geometry must map after here in old
6708 * If the chunk sizes are different, then as we perform reshape
6709 * in units of the largest of the two, reshape_position needs
6710 * be a multiple of the largest chunk size times new data disks.
6712 here_new = mddev->reshape_position;
6713 chunk_sectors = max(mddev->chunk_sectors, mddev->new_chunk_sectors);
6714 new_data_disks = mddev->raid_disks - max_degraded;
6715 if (sector_div(here_new, chunk_sectors * new_data_disks)) {
6716 printk(KERN_ERR "md/raid:%s: reshape_position not "
6717 "on a stripe boundary\n", mdname(mddev));
6720 reshape_offset = here_new * chunk_sectors;
6721 /* here_new is the stripe we will write to */
6722 here_old = mddev->reshape_position;
6723 sector_div(here_old, chunk_sectors * (old_disks-max_degraded));
6724 /* here_old is the first stripe that we might need to read
6726 if (mddev->delta_disks == 0) {
6727 /* We cannot be sure it is safe to start an in-place
6728 * reshape. It is only safe if user-space is monitoring
6729 * and taking constant backups.
6730 * mdadm always starts a situation like this in
6731 * readonly mode so it can take control before
6732 * allowing any writes. So just check for that.
6734 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
6735 abs(min_offset_diff) >= mddev->new_chunk_sectors)
6736 /* not really in-place - so OK */;
6737 else if (mddev->ro == 0) {
6738 printk(KERN_ERR "md/raid:%s: in-place reshape "
6739 "must be started in read-only mode "
6744 } else if (mddev->reshape_backwards
6745 ? (here_new * chunk_sectors + min_offset_diff <=
6746 here_old * chunk_sectors)
6747 : (here_new * chunk_sectors >=
6748 here_old * chunk_sectors + (-min_offset_diff))) {
6749 /* Reading from the same stripe as writing to - bad */
6750 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
6751 "auto-recovery - aborting.\n",
6755 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
6757 /* OK, we should be able to continue; */
6759 BUG_ON(mddev->level != mddev->new_level);
6760 BUG_ON(mddev->layout != mddev->new_layout);
6761 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
6762 BUG_ON(mddev->delta_disks != 0);
6765 if (mddev->private == NULL)
6766 conf = setup_conf(mddev);
6768 conf = mddev->private;
6771 return PTR_ERR(conf);
6773 conf->min_offset_diff = min_offset_diff;
6774 mddev->thread = conf->thread;
6775 conf->thread = NULL;
6776 mddev->private = conf;
6778 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
6780 rdev = conf->disks[i].rdev;
6781 if (!rdev && conf->disks[i].replacement) {
6782 /* The replacement is all we have yet */
6783 rdev = conf->disks[i].replacement;
6784 conf->disks[i].replacement = NULL;
6785 clear_bit(Replacement, &rdev->flags);
6786 conf->disks[i].rdev = rdev;
6790 if (conf->disks[i].replacement &&
6791 conf->reshape_progress != MaxSector) {
6792 /* replacements and reshape simply do not mix. */
6793 printk(KERN_ERR "md: cannot handle concurrent "
6794 "replacement and reshape.\n");
6797 if (test_bit(In_sync, &rdev->flags)) {
6801 /* This disc is not fully in-sync. However if it
6802 * just stored parity (beyond the recovery_offset),
6803 * when we don't need to be concerned about the
6804 * array being dirty.
6805 * When reshape goes 'backwards', we never have
6806 * partially completed devices, so we only need
6807 * to worry about reshape going forwards.
6809 /* Hack because v0.91 doesn't store recovery_offset properly. */
6810 if (mddev->major_version == 0 &&
6811 mddev->minor_version > 90)
6812 rdev->recovery_offset = reshape_offset;
6814 if (rdev->recovery_offset < reshape_offset) {
6815 /* We need to check old and new layout */
6816 if (!only_parity(rdev->raid_disk,
6819 conf->max_degraded))
6822 if (!only_parity(rdev->raid_disk,
6824 conf->previous_raid_disks,
6825 conf->max_degraded))
6827 dirty_parity_disks++;
6831 * 0 for a fully functional array, 1 or 2 for a degraded array.
6833 mddev->degraded = calc_degraded(conf);
6835 if (has_failed(conf)) {
6836 printk(KERN_ERR "md/raid:%s: not enough operational devices"
6837 " (%d/%d failed)\n",
6838 mdname(mddev), mddev->degraded, conf->raid_disks);
6842 /* device size must be a multiple of chunk size */
6843 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
6844 mddev->resync_max_sectors = mddev->dev_sectors;
6846 if (mddev->degraded > dirty_parity_disks &&
6847 mddev->recovery_cp != MaxSector) {
6848 if (mddev->ok_start_degraded)
6850 "md/raid:%s: starting dirty degraded array"
6851 " - data corruption possible.\n",
6855 "md/raid:%s: cannot start dirty degraded array.\n",
6861 if (mddev->degraded == 0)
6862 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
6863 " devices, algorithm %d\n", mdname(mddev), conf->level,
6864 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
6867 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
6868 " out of %d devices, algorithm %d\n",
6869 mdname(mddev), conf->level,
6870 mddev->raid_disks - mddev->degraded,
6871 mddev->raid_disks, mddev->new_layout);
6873 print_raid5_conf(conf);
6875 if (conf->reshape_progress != MaxSector) {
6876 conf->reshape_safe = conf->reshape_progress;
6877 atomic_set(&conf->reshape_stripes, 0);
6878 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6879 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6880 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6881 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6882 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
6886 /* Ok, everything is just fine now */
6887 if (mddev->to_remove == &raid5_attrs_group)
6888 mddev->to_remove = NULL;
6889 else if (mddev->kobj.sd &&
6890 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
6892 "raid5: failed to create sysfs attributes for %s\n",
6894 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6898 bool discard_supported = true;
6899 /* read-ahead size must cover two whole stripes, which
6900 * is 2 * (datadisks) * chunksize where 'n' is the
6901 * number of raid devices
6903 int data_disks = conf->previous_raid_disks - conf->max_degraded;
6904 int stripe = data_disks *
6905 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
6906 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6907 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6909 chunk_size = mddev->chunk_sectors << 9;
6910 blk_queue_io_min(mddev->queue, chunk_size);
6911 blk_queue_io_opt(mddev->queue, chunk_size *
6912 (conf->raid_disks - conf->max_degraded));
6913 mddev->queue->limits.raid_partial_stripes_expensive = 1;
6915 * We can only discard a whole stripe. It doesn't make sense to
6916 * discard data disk but write parity disk
6918 stripe = stripe * PAGE_SIZE;
6919 /* Round up to power of 2, as discard handling
6920 * currently assumes that */
6921 while ((stripe-1) & stripe)
6922 stripe = (stripe | (stripe-1)) + 1;
6923 mddev->queue->limits.discard_alignment = stripe;
6924 mddev->queue->limits.discard_granularity = stripe;
6926 * unaligned part of discard request will be ignored, so can't
6927 * guarantee discard_zeroes_data
6929 mddev->queue->limits.discard_zeroes_data = 0;
6931 blk_queue_max_write_same_sectors(mddev->queue, 0);
6933 rdev_for_each(rdev, mddev) {
6934 disk_stack_limits(mddev->gendisk, rdev->bdev,
6935 rdev->data_offset << 9);
6936 disk_stack_limits(mddev->gendisk, rdev->bdev,
6937 rdev->new_data_offset << 9);
6939 * discard_zeroes_data is required, otherwise data
6940 * could be lost. Consider a scenario: discard a stripe
6941 * (the stripe could be inconsistent if
6942 * discard_zeroes_data is 0); write one disk of the
6943 * stripe (the stripe could be inconsistent again
6944 * depending on which disks are used to calculate
6945 * parity); the disk is broken; The stripe data of this
6948 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
6949 !bdev_get_queue(rdev->bdev)->
6950 limits.discard_zeroes_data)
6951 discard_supported = false;
6952 /* Unfortunately, discard_zeroes_data is not currently
6953 * a guarantee - just a hint. So we only allow DISCARD
6954 * if the sysadmin has confirmed that only safe devices
6955 * are in use by setting a module parameter.
6957 if (!devices_handle_discard_safely) {
6958 if (discard_supported) {
6959 pr_info("md/raid456: discard support disabled due to uncertainty.\n");
6960 pr_info("Set raid456.devices_handle_discard_safely=Y to override.\n");
6962 discard_supported = false;
6966 if (discard_supported &&
6967 mddev->queue->limits.max_discard_sectors >= stripe &&
6968 mddev->queue->limits.discard_granularity >= stripe)
6969 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
6972 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
6978 md_unregister_thread(&mddev->thread);
6979 print_raid5_conf(conf);
6981 mddev->private = NULL;
6982 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
6986 static void raid5_free(struct mddev *mddev, void *priv)
6988 struct r5conf *conf = priv;
6991 mddev->to_remove = &raid5_attrs_group;
6994 static void status(struct seq_file *seq, struct mddev *mddev)
6996 struct r5conf *conf = mddev->private;
6999 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
7000 conf->chunk_sectors / 2, mddev->layout);
7001 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
7002 for (i = 0; i < conf->raid_disks; i++)
7003 seq_printf (seq, "%s",
7004 conf->disks[i].rdev &&
7005 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
7006 seq_printf (seq, "]");
7009 static void print_raid5_conf (struct r5conf *conf)
7012 struct disk_info *tmp;
7014 printk(KERN_DEBUG "RAID conf printout:\n");
7016 printk("(conf==NULL)\n");
7019 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
7021 conf->raid_disks - conf->mddev->degraded);
7023 for (i = 0; i < conf->raid_disks; i++) {
7024 char b[BDEVNAME_SIZE];
7025 tmp = conf->disks + i;
7027 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
7028 i, !test_bit(Faulty, &tmp->rdev->flags),
7029 bdevname(tmp->rdev->bdev, b));
7033 static int raid5_spare_active(struct mddev *mddev)
7036 struct r5conf *conf = mddev->private;
7037 struct disk_info *tmp;
7039 unsigned long flags;
7041 for (i = 0; i < conf->raid_disks; i++) {
7042 tmp = conf->disks + i;
7043 if (tmp->replacement
7044 && tmp->replacement->recovery_offset == MaxSector
7045 && !test_bit(Faulty, &tmp->replacement->flags)
7046 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
7047 /* Replacement has just become active. */
7049 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
7052 /* Replaced device not technically faulty,
7053 * but we need to be sure it gets removed
7054 * and never re-added.
7056 set_bit(Faulty, &tmp->rdev->flags);
7057 sysfs_notify_dirent_safe(
7058 tmp->rdev->sysfs_state);
7060 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
7061 } else if (tmp->rdev
7062 && tmp->rdev->recovery_offset == MaxSector
7063 && !test_bit(Faulty, &tmp->rdev->flags)
7064 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
7066 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
7069 spin_lock_irqsave(&conf->device_lock, flags);
7070 mddev->degraded = calc_degraded(conf);
7071 spin_unlock_irqrestore(&conf->device_lock, flags);
7072 print_raid5_conf(conf);
7076 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
7078 struct r5conf *conf = mddev->private;
7080 int number = rdev->raid_disk;
7081 struct md_rdev **rdevp;
7082 struct disk_info *p = conf->disks + number;
7084 print_raid5_conf(conf);
7085 if (rdev == p->rdev)
7087 else if (rdev == p->replacement)
7088 rdevp = &p->replacement;
7092 if (number >= conf->raid_disks &&
7093 conf->reshape_progress == MaxSector)
7094 clear_bit(In_sync, &rdev->flags);
7096 if (test_bit(In_sync, &rdev->flags) ||
7097 atomic_read(&rdev->nr_pending)) {
7101 /* Only remove non-faulty devices if recovery
7104 if (!test_bit(Faulty, &rdev->flags) &&
7105 mddev->recovery_disabled != conf->recovery_disabled &&
7106 !has_failed(conf) &&
7107 (!p->replacement || p->replacement == rdev) &&
7108 number < conf->raid_disks) {
7114 if (atomic_read(&rdev->nr_pending)) {
7115 /* lost the race, try later */
7118 } else if (p->replacement) {
7119 /* We must have just cleared 'rdev' */
7120 p->rdev = p->replacement;
7121 clear_bit(Replacement, &p->replacement->flags);
7122 smp_mb(); /* Make sure other CPUs may see both as identical
7123 * but will never see neither - if they are careful
7125 p->replacement = NULL;
7126 clear_bit(WantReplacement, &rdev->flags);
7128 /* We might have just removed the Replacement as faulty-
7129 * clear the bit just in case
7131 clear_bit(WantReplacement, &rdev->flags);
7134 print_raid5_conf(conf);
7138 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
7140 struct r5conf *conf = mddev->private;
7143 struct disk_info *p;
7145 int last = conf->raid_disks - 1;
7147 if (mddev->recovery_disabled == conf->recovery_disabled)
7150 if (rdev->saved_raid_disk < 0 && has_failed(conf))
7151 /* no point adding a device */
7154 if (rdev->raid_disk >= 0)
7155 first = last = rdev->raid_disk;
7158 * find the disk ... but prefer rdev->saved_raid_disk
7161 if (rdev->saved_raid_disk >= 0 &&
7162 rdev->saved_raid_disk >= first &&
7163 conf->disks[rdev->saved_raid_disk].rdev == NULL)
7164 first = rdev->saved_raid_disk;
7166 for (disk = first; disk <= last; disk++) {
7167 p = conf->disks + disk;
7168 if (p->rdev == NULL) {
7169 clear_bit(In_sync, &rdev->flags);
7170 rdev->raid_disk = disk;
7172 if (rdev->saved_raid_disk != disk)
7174 rcu_assign_pointer(p->rdev, rdev);
7178 for (disk = first; disk <= last; disk++) {
7179 p = conf->disks + disk;
7180 if (test_bit(WantReplacement, &p->rdev->flags) &&
7181 p->replacement == NULL) {
7182 clear_bit(In_sync, &rdev->flags);
7183 set_bit(Replacement, &rdev->flags);
7184 rdev->raid_disk = disk;
7187 rcu_assign_pointer(p->replacement, rdev);
7192 print_raid5_conf(conf);
7196 static int raid5_resize(struct mddev *mddev, sector_t sectors)
7198 /* no resync is happening, and there is enough space
7199 * on all devices, so we can resize.
7200 * We need to make sure resync covers any new space.
7201 * If the array is shrinking we should possibly wait until
7202 * any io in the removed space completes, but it hardly seems
7206 struct r5conf *conf = mddev->private;
7208 sectors &= ~((sector_t)conf->chunk_sectors - 1);
7209 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
7210 if (mddev->external_size &&
7211 mddev->array_sectors > newsize)
7213 if (mddev->bitmap) {
7214 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
7218 md_set_array_sectors(mddev, newsize);
7219 set_capacity(mddev->gendisk, mddev->array_sectors);
7220 revalidate_disk(mddev->gendisk);
7221 if (sectors > mddev->dev_sectors &&
7222 mddev->recovery_cp > mddev->dev_sectors) {
7223 mddev->recovery_cp = mddev->dev_sectors;
7224 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
7226 mddev->dev_sectors = sectors;
7227 mddev->resync_max_sectors = sectors;
7231 static int check_stripe_cache(struct mddev *mddev)
7233 /* Can only proceed if there are plenty of stripe_heads.
7234 * We need a minimum of one full stripe,, and for sensible progress
7235 * it is best to have about 4 times that.
7236 * If we require 4 times, then the default 256 4K stripe_heads will
7237 * allow for chunk sizes up to 256K, which is probably OK.
7238 * If the chunk size is greater, user-space should request more
7239 * stripe_heads first.
7241 struct r5conf *conf = mddev->private;
7242 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
7243 > conf->min_nr_stripes ||
7244 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
7245 > conf->min_nr_stripes) {
7246 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
7248 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
7255 static int check_reshape(struct mddev *mddev)
7257 struct r5conf *conf = mddev->private;
7259 if (mddev->delta_disks == 0 &&
7260 mddev->new_layout == mddev->layout &&
7261 mddev->new_chunk_sectors == mddev->chunk_sectors)
7262 return 0; /* nothing to do */
7263 if (has_failed(conf))
7265 if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
7266 /* We might be able to shrink, but the devices must
7267 * be made bigger first.
7268 * For raid6, 4 is the minimum size.
7269 * Otherwise 2 is the minimum
7272 if (mddev->level == 6)
7274 if (mddev->raid_disks + mddev->delta_disks < min)
7278 if (!check_stripe_cache(mddev))
7281 if (mddev->new_chunk_sectors > mddev->chunk_sectors ||
7282 mddev->delta_disks > 0)
7283 if (resize_chunks(conf,
7284 conf->previous_raid_disks
7285 + max(0, mddev->delta_disks),
7286 max(mddev->new_chunk_sectors,
7287 mddev->chunk_sectors)
7290 return resize_stripes(conf, (conf->previous_raid_disks
7291 + mddev->delta_disks));
7294 static int raid5_start_reshape(struct mddev *mddev)
7296 struct r5conf *conf = mddev->private;
7297 struct md_rdev *rdev;
7299 unsigned long flags;
7301 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
7304 if (!check_stripe_cache(mddev))
7307 if (has_failed(conf))
7310 rdev_for_each(rdev, mddev) {
7311 if (!test_bit(In_sync, &rdev->flags)
7312 && !test_bit(Faulty, &rdev->flags))
7316 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
7317 /* Not enough devices even to make a degraded array
7322 /* Refuse to reduce size of the array. Any reductions in
7323 * array size must be through explicit setting of array_size
7326 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
7327 < mddev->array_sectors) {
7328 printk(KERN_ERR "md/raid:%s: array size must be reduced "
7329 "before number of disks\n", mdname(mddev));
7333 atomic_set(&conf->reshape_stripes, 0);
7334 spin_lock_irq(&conf->device_lock);
7335 write_seqcount_begin(&conf->gen_lock);
7336 conf->previous_raid_disks = conf->raid_disks;
7337 conf->raid_disks += mddev->delta_disks;
7338 conf->prev_chunk_sectors = conf->chunk_sectors;
7339 conf->chunk_sectors = mddev->new_chunk_sectors;
7340 conf->prev_algo = conf->algorithm;
7341 conf->algorithm = mddev->new_layout;
7343 /* Code that selects data_offset needs to see the generation update
7344 * if reshape_progress has been set - so a memory barrier needed.
7347 if (mddev->reshape_backwards)
7348 conf->reshape_progress = raid5_size(mddev, 0, 0);
7350 conf->reshape_progress = 0;
7351 conf->reshape_safe = conf->reshape_progress;
7352 write_seqcount_end(&conf->gen_lock);
7353 spin_unlock_irq(&conf->device_lock);
7355 /* Now make sure any requests that proceeded on the assumption
7356 * the reshape wasn't running - like Discard or Read - have
7359 mddev_suspend(mddev);
7360 mddev_resume(mddev);
7362 /* Add some new drives, as many as will fit.
7363 * We know there are enough to make the newly sized array work.
7364 * Don't add devices if we are reducing the number of
7365 * devices in the array. This is because it is not possible
7366 * to correctly record the "partially reconstructed" state of
7367 * such devices during the reshape and confusion could result.
7369 if (mddev->delta_disks >= 0) {
7370 rdev_for_each(rdev, mddev)
7371 if (rdev->raid_disk < 0 &&
7372 !test_bit(Faulty, &rdev->flags)) {
7373 if (raid5_add_disk(mddev, rdev) == 0) {
7375 >= conf->previous_raid_disks)
7376 set_bit(In_sync, &rdev->flags);
7378 rdev->recovery_offset = 0;
7380 if (sysfs_link_rdev(mddev, rdev))
7381 /* Failure here is OK */;
7383 } else if (rdev->raid_disk >= conf->previous_raid_disks
7384 && !test_bit(Faulty, &rdev->flags)) {
7385 /* This is a spare that was manually added */
7386 set_bit(In_sync, &rdev->flags);
7389 /* When a reshape changes the number of devices,
7390 * ->degraded is measured against the larger of the
7391 * pre and post number of devices.
7393 spin_lock_irqsave(&conf->device_lock, flags);
7394 mddev->degraded = calc_degraded(conf);
7395 spin_unlock_irqrestore(&conf->device_lock, flags);
7397 mddev->raid_disks = conf->raid_disks;
7398 mddev->reshape_position = conf->reshape_progress;
7399 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7401 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
7402 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
7403 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
7404 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
7405 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
7406 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
7408 if (!mddev->sync_thread) {
7409 mddev->recovery = 0;
7410 spin_lock_irq(&conf->device_lock);
7411 write_seqcount_begin(&conf->gen_lock);
7412 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
7413 mddev->new_chunk_sectors =
7414 conf->chunk_sectors = conf->prev_chunk_sectors;
7415 mddev->new_layout = conf->algorithm = conf->prev_algo;
7416 rdev_for_each(rdev, mddev)
7417 rdev->new_data_offset = rdev->data_offset;
7419 conf->generation --;
7420 conf->reshape_progress = MaxSector;
7421 mddev->reshape_position = MaxSector;
7422 write_seqcount_end(&conf->gen_lock);
7423 spin_unlock_irq(&conf->device_lock);
7426 conf->reshape_checkpoint = jiffies;
7427 md_wakeup_thread(mddev->sync_thread);
7428 md_new_event(mddev);
7432 /* This is called from the reshape thread and should make any
7433 * changes needed in 'conf'
7435 static void end_reshape(struct r5conf *conf)
7438 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
7439 struct md_rdev *rdev;
7441 spin_lock_irq(&conf->device_lock);
7442 conf->previous_raid_disks = conf->raid_disks;
7443 rdev_for_each(rdev, conf->mddev)
7444 rdev->data_offset = rdev->new_data_offset;
7446 conf->reshape_progress = MaxSector;
7447 conf->mddev->reshape_position = MaxSector;
7448 spin_unlock_irq(&conf->device_lock);
7449 wake_up(&conf->wait_for_overlap);
7451 /* read-ahead size must cover two whole stripes, which is
7452 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
7454 if (conf->mddev->queue) {
7455 int data_disks = conf->raid_disks - conf->max_degraded;
7456 int stripe = data_disks * ((conf->chunk_sectors << 9)
7458 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
7459 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
7464 /* This is called from the raid5d thread with mddev_lock held.
7465 * It makes config changes to the device.
7467 static void raid5_finish_reshape(struct mddev *mddev)
7469 struct r5conf *conf = mddev->private;
7471 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
7473 if (mddev->delta_disks > 0) {
7474 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
7475 set_capacity(mddev->gendisk, mddev->array_sectors);
7476 revalidate_disk(mddev->gendisk);
7479 spin_lock_irq(&conf->device_lock);
7480 mddev->degraded = calc_degraded(conf);
7481 spin_unlock_irq(&conf->device_lock);
7482 for (d = conf->raid_disks ;
7483 d < conf->raid_disks - mddev->delta_disks;
7485 struct md_rdev *rdev = conf->disks[d].rdev;
7487 clear_bit(In_sync, &rdev->flags);
7488 rdev = conf->disks[d].replacement;
7490 clear_bit(In_sync, &rdev->flags);
7493 mddev->layout = conf->algorithm;
7494 mddev->chunk_sectors = conf->chunk_sectors;
7495 mddev->reshape_position = MaxSector;
7496 mddev->delta_disks = 0;
7497 mddev->reshape_backwards = 0;
7501 static void raid5_quiesce(struct mddev *mddev, int state)
7503 struct r5conf *conf = mddev->private;
7506 case 2: /* resume for a suspend */
7507 wake_up(&conf->wait_for_overlap);
7510 case 1: /* stop all writes */
7511 lock_all_device_hash_locks_irq(conf);
7512 /* '2' tells resync/reshape to pause so that all
7513 * active stripes can drain
7516 wait_event_cmd(conf->wait_for_quiescent,
7517 atomic_read(&conf->active_stripes) == 0 &&
7518 atomic_read(&conf->active_aligned_reads) == 0,
7519 unlock_all_device_hash_locks_irq(conf),
7520 lock_all_device_hash_locks_irq(conf));
7522 unlock_all_device_hash_locks_irq(conf);
7523 /* allow reshape to continue */
7524 wake_up(&conf->wait_for_overlap);
7527 case 0: /* re-enable writes */
7528 lock_all_device_hash_locks_irq(conf);
7530 wake_up(&conf->wait_for_quiescent);
7531 wake_up(&conf->wait_for_overlap);
7532 unlock_all_device_hash_locks_irq(conf);
7537 static void *raid45_takeover_raid0(struct mddev *mddev, int level)
7539 struct r0conf *raid0_conf = mddev->private;
7542 /* for raid0 takeover only one zone is supported */
7543 if (raid0_conf->nr_strip_zones > 1) {
7544 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
7546 return ERR_PTR(-EINVAL);
7549 sectors = raid0_conf->strip_zone[0].zone_end;
7550 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
7551 mddev->dev_sectors = sectors;
7552 mddev->new_level = level;
7553 mddev->new_layout = ALGORITHM_PARITY_N;
7554 mddev->new_chunk_sectors = mddev->chunk_sectors;
7555 mddev->raid_disks += 1;
7556 mddev->delta_disks = 1;
7557 /* make sure it will be not marked as dirty */
7558 mddev->recovery_cp = MaxSector;
7560 return setup_conf(mddev);
7563 static void *raid5_takeover_raid1(struct mddev *mddev)
7567 if (mddev->raid_disks != 2 ||
7568 mddev->degraded > 1)
7569 return ERR_PTR(-EINVAL);
7571 /* Should check if there are write-behind devices? */
7573 chunksect = 64*2; /* 64K by default */
7575 /* The array must be an exact multiple of chunksize */
7576 while (chunksect && (mddev->array_sectors & (chunksect-1)))
7579 if ((chunksect<<9) < STRIPE_SIZE)
7580 /* array size does not allow a suitable chunk size */
7581 return ERR_PTR(-EINVAL);
7583 mddev->new_level = 5;
7584 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
7585 mddev->new_chunk_sectors = chunksect;
7587 return setup_conf(mddev);
7590 static void *raid5_takeover_raid6(struct mddev *mddev)
7594 switch (mddev->layout) {
7595 case ALGORITHM_LEFT_ASYMMETRIC_6:
7596 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
7598 case ALGORITHM_RIGHT_ASYMMETRIC_6:
7599 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
7601 case ALGORITHM_LEFT_SYMMETRIC_6:
7602 new_layout = ALGORITHM_LEFT_SYMMETRIC;
7604 case ALGORITHM_RIGHT_SYMMETRIC_6:
7605 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
7607 case ALGORITHM_PARITY_0_6:
7608 new_layout = ALGORITHM_PARITY_0;
7610 case ALGORITHM_PARITY_N:
7611 new_layout = ALGORITHM_PARITY_N;
7614 return ERR_PTR(-EINVAL);
7616 mddev->new_level = 5;
7617 mddev->new_layout = new_layout;
7618 mddev->delta_disks = -1;
7619 mddev->raid_disks -= 1;
7620 return setup_conf(mddev);
7623 static int raid5_check_reshape(struct mddev *mddev)
7625 /* For a 2-drive array, the layout and chunk size can be changed
7626 * immediately as not restriping is needed.
7627 * For larger arrays we record the new value - after validation
7628 * to be used by a reshape pass.
7630 struct r5conf *conf = mddev->private;
7631 int new_chunk = mddev->new_chunk_sectors;
7633 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
7635 if (new_chunk > 0) {
7636 if (!is_power_of_2(new_chunk))
7638 if (new_chunk < (PAGE_SIZE>>9))
7640 if (mddev->array_sectors & (new_chunk-1))
7641 /* not factor of array size */
7645 /* They look valid */
7647 if (mddev->raid_disks == 2) {
7648 /* can make the change immediately */
7649 if (mddev->new_layout >= 0) {
7650 conf->algorithm = mddev->new_layout;
7651 mddev->layout = mddev->new_layout;
7653 if (new_chunk > 0) {
7654 conf->chunk_sectors = new_chunk ;
7655 mddev->chunk_sectors = new_chunk;
7657 set_bit(MD_CHANGE_DEVS, &mddev->flags);
7658 md_wakeup_thread(mddev->thread);
7660 return check_reshape(mddev);
7663 static int raid6_check_reshape(struct mddev *mddev)
7665 int new_chunk = mddev->new_chunk_sectors;
7667 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
7669 if (new_chunk > 0) {
7670 if (!is_power_of_2(new_chunk))
7672 if (new_chunk < (PAGE_SIZE >> 9))
7674 if (mddev->array_sectors & (new_chunk-1))
7675 /* not factor of array size */
7679 /* They look valid */
7680 return check_reshape(mddev);
7683 static void *raid5_takeover(struct mddev *mddev)
7685 /* raid5 can take over:
7686 * raid0 - if there is only one strip zone - make it a raid4 layout
7687 * raid1 - if there are two drives. We need to know the chunk size
7688 * raid4 - trivial - just use a raid4 layout.
7689 * raid6 - Providing it is a *_6 layout
7691 if (mddev->level == 0)
7692 return raid45_takeover_raid0(mddev, 5);
7693 if (mddev->level == 1)
7694 return raid5_takeover_raid1(mddev);
7695 if (mddev->level == 4) {
7696 mddev->new_layout = ALGORITHM_PARITY_N;
7697 mddev->new_level = 5;
7698 return setup_conf(mddev);
7700 if (mddev->level == 6)
7701 return raid5_takeover_raid6(mddev);
7703 return ERR_PTR(-EINVAL);
7706 static void *raid4_takeover(struct mddev *mddev)
7708 /* raid4 can take over:
7709 * raid0 - if there is only one strip zone
7710 * raid5 - if layout is right
7712 if (mddev->level == 0)
7713 return raid45_takeover_raid0(mddev, 4);
7714 if (mddev->level == 5 &&
7715 mddev->layout == ALGORITHM_PARITY_N) {
7716 mddev->new_layout = 0;
7717 mddev->new_level = 4;
7718 return setup_conf(mddev);
7720 return ERR_PTR(-EINVAL);
7723 static struct md_personality raid5_personality;
7725 static void *raid6_takeover(struct mddev *mddev)
7727 /* Currently can only take over a raid5. We map the
7728 * personality to an equivalent raid6 personality
7729 * with the Q block at the end.
7733 if (mddev->pers != &raid5_personality)
7734 return ERR_PTR(-EINVAL);
7735 if (mddev->degraded > 1)
7736 return ERR_PTR(-EINVAL);
7737 if (mddev->raid_disks > 253)
7738 return ERR_PTR(-EINVAL);
7739 if (mddev->raid_disks < 3)
7740 return ERR_PTR(-EINVAL);
7742 switch (mddev->layout) {
7743 case ALGORITHM_LEFT_ASYMMETRIC:
7744 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
7746 case ALGORITHM_RIGHT_ASYMMETRIC:
7747 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
7749 case ALGORITHM_LEFT_SYMMETRIC:
7750 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
7752 case ALGORITHM_RIGHT_SYMMETRIC:
7753 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
7755 case ALGORITHM_PARITY_0:
7756 new_layout = ALGORITHM_PARITY_0_6;
7758 case ALGORITHM_PARITY_N:
7759 new_layout = ALGORITHM_PARITY_N;
7762 return ERR_PTR(-EINVAL);
7764 mddev->new_level = 6;
7765 mddev->new_layout = new_layout;
7766 mddev->delta_disks = 1;
7767 mddev->raid_disks += 1;
7768 return setup_conf(mddev);
7771 static struct md_personality raid6_personality =
7775 .owner = THIS_MODULE,
7776 .make_request = make_request,
7780 .error_handler = error,
7781 .hot_add_disk = raid5_add_disk,
7782 .hot_remove_disk= raid5_remove_disk,
7783 .spare_active = raid5_spare_active,
7784 .sync_request = sync_request,
7785 .resize = raid5_resize,
7787 .check_reshape = raid6_check_reshape,
7788 .start_reshape = raid5_start_reshape,
7789 .finish_reshape = raid5_finish_reshape,
7790 .quiesce = raid5_quiesce,
7791 .takeover = raid6_takeover,
7792 .congested = raid5_congested,
7794 static struct md_personality raid5_personality =
7798 .owner = THIS_MODULE,
7799 .make_request = make_request,
7803 .error_handler = error,
7804 .hot_add_disk = raid5_add_disk,
7805 .hot_remove_disk= raid5_remove_disk,
7806 .spare_active = raid5_spare_active,
7807 .sync_request = sync_request,
7808 .resize = raid5_resize,
7810 .check_reshape = raid5_check_reshape,
7811 .start_reshape = raid5_start_reshape,
7812 .finish_reshape = raid5_finish_reshape,
7813 .quiesce = raid5_quiesce,
7814 .takeover = raid5_takeover,
7815 .congested = raid5_congested,
7818 static struct md_personality raid4_personality =
7822 .owner = THIS_MODULE,
7823 .make_request = make_request,
7827 .error_handler = error,
7828 .hot_add_disk = raid5_add_disk,
7829 .hot_remove_disk= raid5_remove_disk,
7830 .spare_active = raid5_spare_active,
7831 .sync_request = sync_request,
7832 .resize = raid5_resize,
7834 .check_reshape = raid5_check_reshape,
7835 .start_reshape = raid5_start_reshape,
7836 .finish_reshape = raid5_finish_reshape,
7837 .quiesce = raid5_quiesce,
7838 .takeover = raid4_takeover,
7839 .congested = raid5_congested,
7842 static int __init raid5_init(void)
7844 raid5_wq = alloc_workqueue("raid5wq",
7845 WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
7848 register_md_personality(&raid6_personality);
7849 register_md_personality(&raid5_personality);
7850 register_md_personality(&raid4_personality);
7854 static void raid5_exit(void)
7856 unregister_md_personality(&raid6_personality);
7857 unregister_md_personality(&raid5_personality);
7858 unregister_md_personality(&raid4_personality);
7859 destroy_workqueue(raid5_wq);
7862 module_init(raid5_init);
7863 module_exit(raid5_exit);
7864 MODULE_LICENSE("GPL");
7865 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
7866 MODULE_ALIAS("md-personality-4"); /* RAID5 */
7867 MODULE_ALIAS("md-raid5");
7868 MODULE_ALIAS("md-raid4");
7869 MODULE_ALIAS("md-level-5");
7870 MODULE_ALIAS("md-level-4");
7871 MODULE_ALIAS("md-personality-8"); /* RAID6 */
7872 MODULE_ALIAS("md-raid6");
7873 MODULE_ALIAS("md-level-6");
7875 /* This used to be two separate modules, they were: */
7876 MODULE_ALIAS("raid5");
7877 MODULE_ALIAS("raid6");