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 <trace/events/block.h>
64 #define cpu_to_group(cpu) cpu_to_node(cpu)
65 #define ANY_GROUP NUMA_NO_NODE
67 static struct workqueue_struct *raid5_wq;
72 #define NR_STRIPES 256
73 #define STRIPE_SIZE PAGE_SIZE
74 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
75 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
76 #define IO_THRESHOLD 1
77 #define BYPASS_THRESHOLD 1
78 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
79 #define HASH_MASK (NR_HASH - 1)
80 #define MAX_STRIPE_BATCH 8
82 static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
84 int hash = (sect >> STRIPE_SHIFT) & HASH_MASK;
85 return &conf->stripe_hashtbl[hash];
88 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
89 * order without overlap. There may be several bio's per stripe+device, and
90 * a bio could span several devices.
91 * When walking this list for a particular stripe+device, we must never proceed
92 * beyond a bio that extends past this device, as the next bio might no longer
94 * This function is used to determine the 'next' bio in the list, given the sector
95 * of the current stripe+device
97 static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
99 int sectors = bio_sectors(bio);
100 if (bio->bi_sector + sectors < sector + STRIPE_SECTORS)
107 * We maintain a biased count of active stripes in the bottom 16 bits of
108 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
110 static inline int raid5_bi_processed_stripes(struct bio *bio)
112 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
113 return (atomic_read(segments) >> 16) & 0xffff;
116 static inline int raid5_dec_bi_active_stripes(struct bio *bio)
118 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
119 return atomic_sub_return(1, segments) & 0xffff;
122 static inline void raid5_inc_bi_active_stripes(struct bio *bio)
124 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
125 atomic_inc(segments);
128 static inline void raid5_set_bi_processed_stripes(struct bio *bio,
131 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
135 old = atomic_read(segments);
136 new = (old & 0xffff) | (cnt << 16);
137 } while (atomic_cmpxchg(segments, old, new) != old);
140 static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
142 atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
143 atomic_set(segments, cnt);
146 /* Find first data disk in a raid6 stripe */
147 static inline int raid6_d0(struct stripe_head *sh)
150 /* ddf always start from first device */
152 /* md starts just after Q block */
153 if (sh->qd_idx == sh->disks - 1)
156 return sh->qd_idx + 1;
158 static inline int raid6_next_disk(int disk, int raid_disks)
161 return (disk < raid_disks) ? disk : 0;
164 /* When walking through the disks in a raid5, starting at raid6_d0,
165 * We need to map each disk to a 'slot', where the data disks are slot
166 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
167 * is raid_disks-1. This help does that mapping.
169 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
170 int *count, int syndrome_disks)
176 if (idx == sh->pd_idx)
177 return syndrome_disks;
178 if (idx == sh->qd_idx)
179 return syndrome_disks + 1;
185 static void return_io(struct bio *return_bi)
187 struct bio *bi = return_bi;
190 return_bi = bi->bi_next;
193 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
200 static void print_raid5_conf (struct r5conf *conf);
202 static int stripe_operations_active(struct stripe_head *sh)
204 return sh->check_state || sh->reconstruct_state ||
205 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
206 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
209 static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
211 struct r5conf *conf = sh->raid_conf;
212 struct r5worker_group *group;
214 int i, cpu = sh->cpu;
216 if (!cpu_online(cpu)) {
217 cpu = cpumask_any(cpu_online_mask);
221 if (list_empty(&sh->lru)) {
222 struct r5worker_group *group;
223 group = conf->worker_groups + cpu_to_group(cpu);
224 list_add_tail(&sh->lru, &group->handle_list);
225 group->stripes_cnt++;
229 if (conf->worker_cnt_per_group == 0) {
230 md_wakeup_thread(conf->mddev->thread);
234 group = conf->worker_groups + cpu_to_group(sh->cpu);
236 group->workers[0].working = true;
237 /* at least one worker should run to avoid race */
238 queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
240 thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
241 /* wakeup more workers */
242 for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
243 if (group->workers[i].working == false) {
244 group->workers[i].working = true;
245 queue_work_on(sh->cpu, raid5_wq,
246 &group->workers[i].work);
252 static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh)
254 BUG_ON(!list_empty(&sh->lru));
255 BUG_ON(atomic_read(&conf->active_stripes)==0);
256 if (test_bit(STRIPE_HANDLE, &sh->state)) {
257 if (test_bit(STRIPE_DELAYED, &sh->state) &&
258 !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
259 list_add_tail(&sh->lru, &conf->delayed_list);
260 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
261 sh->bm_seq - conf->seq_write > 0)
262 list_add_tail(&sh->lru, &conf->bitmap_list);
264 clear_bit(STRIPE_DELAYED, &sh->state);
265 clear_bit(STRIPE_BIT_DELAY, &sh->state);
266 if (conf->worker_cnt_per_group == 0) {
267 list_add_tail(&sh->lru, &conf->handle_list);
269 raid5_wakeup_stripe_thread(sh);
273 md_wakeup_thread(conf->mddev->thread);
275 BUG_ON(stripe_operations_active(sh));
276 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
277 if (atomic_dec_return(&conf->preread_active_stripes)
279 md_wakeup_thread(conf->mddev->thread);
280 atomic_dec(&conf->active_stripes);
281 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
282 list_add_tail(&sh->lru, &conf->inactive_list);
283 wake_up(&conf->wait_for_stripe);
284 if (conf->retry_read_aligned)
285 md_wakeup_thread(conf->mddev->thread);
290 static void __release_stripe(struct r5conf *conf, struct stripe_head *sh)
292 if (atomic_dec_and_test(&sh->count))
293 do_release_stripe(conf, sh);
296 static struct llist_node *llist_reverse_order(struct llist_node *head)
298 struct llist_node *new_head = NULL;
301 struct llist_node *tmp = head;
303 tmp->next = new_head;
310 /* should hold conf->device_lock already */
311 static int release_stripe_list(struct r5conf *conf)
313 struct stripe_head *sh;
315 struct llist_node *head;
317 head = llist_del_all(&conf->released_stripes);
318 head = llist_reverse_order(head);
320 sh = llist_entry(head, struct stripe_head, release_list);
321 head = llist_next(head);
322 /* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
324 clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
326 * Don't worry the bit is set here, because if the bit is set
327 * again, the count is always > 1. This is true for
328 * STRIPE_ON_UNPLUG_LIST bit too.
330 __release_stripe(conf, sh);
337 static void release_stripe(struct stripe_head *sh)
339 struct r5conf *conf = sh->raid_conf;
343 if (test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
345 wakeup = llist_add(&sh->release_list, &conf->released_stripes);
347 md_wakeup_thread(conf->mddev->thread);
350 local_irq_save(flags);
351 /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
352 if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
353 do_release_stripe(conf, sh);
354 spin_unlock(&conf->device_lock);
356 local_irq_restore(flags);
359 static inline void remove_hash(struct stripe_head *sh)
361 pr_debug("remove_hash(), stripe %llu\n",
362 (unsigned long long)sh->sector);
364 hlist_del_init(&sh->hash);
367 static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
369 struct hlist_head *hp = stripe_hash(conf, sh->sector);
371 pr_debug("insert_hash(), stripe %llu\n",
372 (unsigned long long)sh->sector);
374 hlist_add_head(&sh->hash, hp);
378 /* find an idle stripe, make sure it is unhashed, and return it. */
379 static struct stripe_head *get_free_stripe(struct r5conf *conf)
381 struct stripe_head *sh = NULL;
382 struct list_head *first;
384 if (list_empty(&conf->inactive_list))
386 first = conf->inactive_list.next;
387 sh = list_entry(first, struct stripe_head, lru);
388 list_del_init(first);
390 atomic_inc(&conf->active_stripes);
395 static void shrink_buffers(struct stripe_head *sh)
399 int num = sh->raid_conf->pool_size;
401 for (i = 0; i < num ; i++) {
405 sh->dev[i].page = NULL;
410 static int grow_buffers(struct stripe_head *sh)
413 int num = sh->raid_conf->pool_size;
415 for (i = 0; i < num; i++) {
418 if (!(page = alloc_page(GFP_KERNEL))) {
421 sh->dev[i].page = page;
426 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
427 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
428 struct stripe_head *sh);
430 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
432 struct r5conf *conf = sh->raid_conf;
435 BUG_ON(atomic_read(&sh->count) != 0);
436 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
437 BUG_ON(stripe_operations_active(sh));
439 pr_debug("init_stripe called, stripe %llu\n",
440 (unsigned long long)sh->sector);
444 sh->generation = conf->generation - previous;
445 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
447 stripe_set_idx(sector, conf, previous, sh);
451 for (i = sh->disks; i--; ) {
452 struct r5dev *dev = &sh->dev[i];
454 if (dev->toread || dev->read || dev->towrite || dev->written ||
455 test_bit(R5_LOCKED, &dev->flags)) {
456 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
457 (unsigned long long)sh->sector, i, dev->toread,
458 dev->read, dev->towrite, dev->written,
459 test_bit(R5_LOCKED, &dev->flags));
463 raid5_build_block(sh, i, previous);
465 insert_hash(conf, sh);
466 sh->cpu = smp_processor_id();
469 static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
472 struct stripe_head *sh;
474 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
475 hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
476 if (sh->sector == sector && sh->generation == generation)
478 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
483 * Need to check if array has failed when deciding whether to:
485 * - remove non-faulty devices
488 * This determination is simple when no reshape is happening.
489 * However if there is a reshape, we need to carefully check
490 * both the before and after sections.
491 * This is because some failed devices may only affect one
492 * of the two sections, and some non-in_sync devices may
493 * be insync in the section most affected by failed devices.
495 static int calc_degraded(struct r5conf *conf)
497 int degraded, degraded2;
502 for (i = 0; i < conf->previous_raid_disks; i++) {
503 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
504 if (rdev && test_bit(Faulty, &rdev->flags))
505 rdev = rcu_dereference(conf->disks[i].replacement);
506 if (!rdev || test_bit(Faulty, &rdev->flags))
508 else if (test_bit(In_sync, &rdev->flags))
511 /* not in-sync or faulty.
512 * If the reshape increases the number of devices,
513 * this is being recovered by the reshape, so
514 * this 'previous' section is not in_sync.
515 * If the number of devices is being reduced however,
516 * the device can only be part of the array if
517 * we are reverting a reshape, so this section will
520 if (conf->raid_disks >= conf->previous_raid_disks)
524 if (conf->raid_disks == conf->previous_raid_disks)
528 for (i = 0; i < conf->raid_disks; i++) {
529 struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
530 if (rdev && test_bit(Faulty, &rdev->flags))
531 rdev = rcu_dereference(conf->disks[i].replacement);
532 if (!rdev || test_bit(Faulty, &rdev->flags))
534 else if (test_bit(In_sync, &rdev->flags))
537 /* not in-sync or faulty.
538 * If reshape increases the number of devices, this
539 * section has already been recovered, else it
540 * almost certainly hasn't.
542 if (conf->raid_disks <= conf->previous_raid_disks)
546 if (degraded2 > degraded)
551 static int has_failed(struct r5conf *conf)
555 if (conf->mddev->reshape_position == MaxSector)
556 return conf->mddev->degraded > conf->max_degraded;
558 degraded = calc_degraded(conf);
559 if (degraded > conf->max_degraded)
564 static struct stripe_head *
565 get_active_stripe(struct r5conf *conf, sector_t sector,
566 int previous, int noblock, int noquiesce)
568 struct stripe_head *sh;
570 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
572 spin_lock_irq(&conf->device_lock);
575 wait_event_lock_irq(conf->wait_for_stripe,
576 conf->quiesce == 0 || noquiesce,
578 sh = __find_stripe(conf, sector, conf->generation - previous);
580 if (!conf->inactive_blocked)
581 sh = get_free_stripe(conf);
582 if (noblock && sh == NULL)
585 conf->inactive_blocked = 1;
586 wait_event_lock_irq(conf->wait_for_stripe,
587 !list_empty(&conf->inactive_list) &&
588 (atomic_read(&conf->active_stripes)
589 < (conf->max_nr_stripes *3/4)
590 || !conf->inactive_blocked),
592 conf->inactive_blocked = 0;
594 init_stripe(sh, sector, previous);
596 if (atomic_read(&sh->count)) {
597 BUG_ON(!list_empty(&sh->lru)
598 && !test_bit(STRIPE_EXPANDING, &sh->state)
599 && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)
600 && !test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
602 if (!test_bit(STRIPE_HANDLE, &sh->state))
603 atomic_inc(&conf->active_stripes);
604 if (list_empty(&sh->lru) &&
605 !test_bit(STRIPE_EXPANDING, &sh->state))
607 list_del_init(&sh->lru);
609 sh->group->stripes_cnt--;
614 } while (sh == NULL);
617 atomic_inc(&sh->count);
619 spin_unlock_irq(&conf->device_lock);
623 /* Determine if 'data_offset' or 'new_data_offset' should be used
624 * in this stripe_head.
626 static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
628 sector_t progress = conf->reshape_progress;
629 /* Need a memory barrier to make sure we see the value
630 * of conf->generation, or ->data_offset that was set before
631 * reshape_progress was updated.
634 if (progress == MaxSector)
636 if (sh->generation == conf->generation - 1)
638 /* We are in a reshape, and this is a new-generation stripe,
639 * so use new_data_offset.
645 raid5_end_read_request(struct bio *bi, int error);
647 raid5_end_write_request(struct bio *bi, int error);
649 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
651 struct r5conf *conf = sh->raid_conf;
652 int i, disks = sh->disks;
656 for (i = disks; i--; ) {
658 int replace_only = 0;
659 struct bio *bi, *rbi;
660 struct md_rdev *rdev, *rrdev = NULL;
661 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
662 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
666 if (test_bit(R5_Discard, &sh->dev[i].flags))
668 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
670 else if (test_and_clear_bit(R5_WantReplace,
671 &sh->dev[i].flags)) {
676 if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
679 bi = &sh->dev[i].req;
680 rbi = &sh->dev[i].rreq; /* For writing to replacement */
683 rrdev = rcu_dereference(conf->disks[i].replacement);
684 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
685 rdev = rcu_dereference(conf->disks[i].rdev);
694 /* We raced and saw duplicates */
697 if (test_bit(R5_ReadRepl, &sh->dev[i].flags) && rrdev)
702 if (rdev && test_bit(Faulty, &rdev->flags))
705 atomic_inc(&rdev->nr_pending);
706 if (rrdev && test_bit(Faulty, &rrdev->flags))
709 atomic_inc(&rrdev->nr_pending);
712 /* We have already checked bad blocks for reads. Now
713 * need to check for writes. We never accept write errors
714 * on the replacement, so we don't to check rrdev.
716 while ((rw & WRITE) && rdev &&
717 test_bit(WriteErrorSeen, &rdev->flags)) {
720 int bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
721 &first_bad, &bad_sectors);
726 set_bit(BlockedBadBlocks, &rdev->flags);
727 if (!conf->mddev->external &&
728 conf->mddev->flags) {
729 /* It is very unlikely, but we might
730 * still need to write out the
731 * bad block log - better give it
733 md_check_recovery(conf->mddev);
736 * Because md_wait_for_blocked_rdev
737 * will dec nr_pending, we must
738 * increment it first.
740 atomic_inc(&rdev->nr_pending);
741 md_wait_for_blocked_rdev(rdev, conf->mddev);
743 /* Acknowledged bad block - skip the write */
744 rdev_dec_pending(rdev, conf->mddev);
750 if (s->syncing || s->expanding || s->expanded
752 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
754 set_bit(STRIPE_IO_STARTED, &sh->state);
757 bi->bi_bdev = rdev->bdev;
759 bi->bi_end_io = (rw & WRITE)
760 ? raid5_end_write_request
761 : raid5_end_read_request;
764 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
765 __func__, (unsigned long long)sh->sector,
767 atomic_inc(&sh->count);
768 if (use_new_offset(conf, sh))
769 bi->bi_sector = (sh->sector
770 + rdev->new_data_offset);
772 bi->bi_sector = (sh->sector
773 + rdev->data_offset);
774 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
775 bi->bi_rw |= REQ_FLUSH;
778 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
779 bi->bi_io_vec[0].bv_offset = 0;
780 bi->bi_size = STRIPE_SIZE;
782 * If this is discard request, set bi_vcnt 0. We don't
783 * want to confuse SCSI because SCSI will replace payload
785 if (rw & REQ_DISCARD)
788 set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
790 if (conf->mddev->gendisk)
791 trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
792 bi, disk_devt(conf->mddev->gendisk),
794 generic_make_request(bi);
797 if (s->syncing || s->expanding || s->expanded
799 md_sync_acct(rrdev->bdev, STRIPE_SECTORS);
801 set_bit(STRIPE_IO_STARTED, &sh->state);
804 rbi->bi_bdev = rrdev->bdev;
806 BUG_ON(!(rw & WRITE));
807 rbi->bi_end_io = raid5_end_write_request;
808 rbi->bi_private = sh;
810 pr_debug("%s: for %llu schedule op %ld on "
811 "replacement disc %d\n",
812 __func__, (unsigned long long)sh->sector,
814 atomic_inc(&sh->count);
815 if (use_new_offset(conf, sh))
816 rbi->bi_sector = (sh->sector
817 + rrdev->new_data_offset);
819 rbi->bi_sector = (sh->sector
820 + rrdev->data_offset);
822 rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
823 rbi->bi_io_vec[0].bv_offset = 0;
824 rbi->bi_size = STRIPE_SIZE;
826 * If this is discard request, set bi_vcnt 0. We don't
827 * want to confuse SCSI because SCSI will replace payload
829 if (rw & REQ_DISCARD)
831 if (conf->mddev->gendisk)
832 trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
833 rbi, disk_devt(conf->mddev->gendisk),
835 generic_make_request(rbi);
837 if (!rdev && !rrdev) {
839 set_bit(STRIPE_DEGRADED, &sh->state);
840 pr_debug("skip op %ld on disc %d for sector %llu\n",
841 bi->bi_rw, i, (unsigned long long)sh->sector);
842 clear_bit(R5_LOCKED, &sh->dev[i].flags);
843 set_bit(STRIPE_HANDLE, &sh->state);
848 static struct dma_async_tx_descriptor *
849 async_copy_data(int frombio, struct bio *bio, struct page *page,
850 sector_t sector, struct dma_async_tx_descriptor *tx)
853 struct page *bio_page;
856 struct async_submit_ctl submit;
857 enum async_tx_flags flags = 0;
859 if (bio->bi_sector >= sector)
860 page_offset = (signed)(bio->bi_sector - sector) * 512;
862 page_offset = (signed)(sector - bio->bi_sector) * -512;
865 flags |= ASYNC_TX_FENCE;
866 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
868 bio_for_each_segment(bvl, bio, i) {
869 int len = bvl->bv_len;
873 if (page_offset < 0) {
874 b_offset = -page_offset;
875 page_offset += b_offset;
879 if (len > 0 && page_offset + len > STRIPE_SIZE)
880 clen = STRIPE_SIZE - page_offset;
885 b_offset += bvl->bv_offset;
886 bio_page = bvl->bv_page;
888 tx = async_memcpy(page, bio_page, page_offset,
889 b_offset, clen, &submit);
891 tx = async_memcpy(bio_page, page, b_offset,
892 page_offset, clen, &submit);
894 /* chain the operations */
895 submit.depend_tx = tx;
897 if (clen < len) /* hit end of page */
905 static void ops_complete_biofill(void *stripe_head_ref)
907 struct stripe_head *sh = stripe_head_ref;
908 struct bio *return_bi = NULL;
911 pr_debug("%s: stripe %llu\n", __func__,
912 (unsigned long long)sh->sector);
914 /* clear completed biofills */
915 for (i = sh->disks; i--; ) {
916 struct r5dev *dev = &sh->dev[i];
918 /* acknowledge completion of a biofill operation */
919 /* and check if we need to reply to a read request,
920 * new R5_Wantfill requests are held off until
921 * !STRIPE_BIOFILL_RUN
923 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
924 struct bio *rbi, *rbi2;
929 while (rbi && rbi->bi_sector <
930 dev->sector + STRIPE_SECTORS) {
931 rbi2 = r5_next_bio(rbi, dev->sector);
932 if (!raid5_dec_bi_active_stripes(rbi)) {
933 rbi->bi_next = return_bi;
940 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
942 return_io(return_bi);
944 set_bit(STRIPE_HANDLE, &sh->state);
948 static void ops_run_biofill(struct stripe_head *sh)
950 struct dma_async_tx_descriptor *tx = NULL;
951 struct async_submit_ctl submit;
954 pr_debug("%s: stripe %llu\n", __func__,
955 (unsigned long long)sh->sector);
957 for (i = sh->disks; i--; ) {
958 struct r5dev *dev = &sh->dev[i];
959 if (test_bit(R5_Wantfill, &dev->flags)) {
961 spin_lock_irq(&sh->stripe_lock);
962 dev->read = rbi = dev->toread;
964 spin_unlock_irq(&sh->stripe_lock);
965 while (rbi && rbi->bi_sector <
966 dev->sector + STRIPE_SECTORS) {
967 tx = async_copy_data(0, rbi, dev->page,
969 rbi = r5_next_bio(rbi, dev->sector);
974 atomic_inc(&sh->count);
975 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
976 async_trigger_callback(&submit);
979 static void mark_target_uptodate(struct stripe_head *sh, int target)
986 tgt = &sh->dev[target];
987 set_bit(R5_UPTODATE, &tgt->flags);
988 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
989 clear_bit(R5_Wantcompute, &tgt->flags);
992 static void ops_complete_compute(void *stripe_head_ref)
994 struct stripe_head *sh = stripe_head_ref;
996 pr_debug("%s: stripe %llu\n", __func__,
997 (unsigned long long)sh->sector);
999 /* mark the computed target(s) as uptodate */
1000 mark_target_uptodate(sh, sh->ops.target);
1001 mark_target_uptodate(sh, sh->ops.target2);
1003 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
1004 if (sh->check_state == check_state_compute_run)
1005 sh->check_state = check_state_compute_result;
1006 set_bit(STRIPE_HANDLE, &sh->state);
1010 /* return a pointer to the address conversion region of the scribble buffer */
1011 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
1012 struct raid5_percpu *percpu)
1014 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
1017 static struct dma_async_tx_descriptor *
1018 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
1020 int disks = sh->disks;
1021 struct page **xor_srcs = percpu->scribble;
1022 int target = sh->ops.target;
1023 struct r5dev *tgt = &sh->dev[target];
1024 struct page *xor_dest = tgt->page;
1026 struct dma_async_tx_descriptor *tx;
1027 struct async_submit_ctl submit;
1030 pr_debug("%s: stripe %llu block: %d\n",
1031 __func__, (unsigned long long)sh->sector, target);
1032 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1034 for (i = disks; i--; )
1036 xor_srcs[count++] = sh->dev[i].page;
1038 atomic_inc(&sh->count);
1040 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
1041 ops_complete_compute, sh, to_addr_conv(sh, percpu));
1042 if (unlikely(count == 1))
1043 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1045 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1050 /* set_syndrome_sources - populate source buffers for gen_syndrome
1051 * @srcs - (struct page *) array of size sh->disks
1052 * @sh - stripe_head to parse
1054 * Populates srcs in proper layout order for the stripe and returns the
1055 * 'count' of sources to be used in a call to async_gen_syndrome. The P
1056 * destination buffer is recorded in srcs[count] and the Q destination
1057 * is recorded in srcs[count+1]].
1059 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
1061 int disks = sh->disks;
1062 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1063 int d0_idx = raid6_d0(sh);
1067 for (i = 0; i < disks; i++)
1073 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1075 srcs[slot] = sh->dev[i].page;
1076 i = raid6_next_disk(i, disks);
1077 } while (i != d0_idx);
1079 return syndrome_disks;
1082 static struct dma_async_tx_descriptor *
1083 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
1085 int disks = sh->disks;
1086 struct page **blocks = percpu->scribble;
1088 int qd_idx = sh->qd_idx;
1089 struct dma_async_tx_descriptor *tx;
1090 struct async_submit_ctl submit;
1096 if (sh->ops.target < 0)
1097 target = sh->ops.target2;
1098 else if (sh->ops.target2 < 0)
1099 target = sh->ops.target;
1101 /* we should only have one valid target */
1104 pr_debug("%s: stripe %llu block: %d\n",
1105 __func__, (unsigned long long)sh->sector, target);
1107 tgt = &sh->dev[target];
1108 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1111 atomic_inc(&sh->count);
1113 if (target == qd_idx) {
1114 count = set_syndrome_sources(blocks, sh);
1115 blocks[count] = NULL; /* regenerating p is not necessary */
1116 BUG_ON(blocks[count+1] != dest); /* q should already be set */
1117 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1118 ops_complete_compute, sh,
1119 to_addr_conv(sh, percpu));
1120 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1122 /* Compute any data- or p-drive using XOR */
1124 for (i = disks; i-- ; ) {
1125 if (i == target || i == qd_idx)
1127 blocks[count++] = sh->dev[i].page;
1130 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1131 NULL, ops_complete_compute, sh,
1132 to_addr_conv(sh, percpu));
1133 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
1139 static struct dma_async_tx_descriptor *
1140 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
1142 int i, count, disks = sh->disks;
1143 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1144 int d0_idx = raid6_d0(sh);
1145 int faila = -1, failb = -1;
1146 int target = sh->ops.target;
1147 int target2 = sh->ops.target2;
1148 struct r5dev *tgt = &sh->dev[target];
1149 struct r5dev *tgt2 = &sh->dev[target2];
1150 struct dma_async_tx_descriptor *tx;
1151 struct page **blocks = percpu->scribble;
1152 struct async_submit_ctl submit;
1154 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1155 __func__, (unsigned long long)sh->sector, target, target2);
1156 BUG_ON(target < 0 || target2 < 0);
1157 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
1158 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
1160 /* we need to open-code set_syndrome_sources to handle the
1161 * slot number conversion for 'faila' and 'failb'
1163 for (i = 0; i < disks ; i++)
1168 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1170 blocks[slot] = sh->dev[i].page;
1176 i = raid6_next_disk(i, disks);
1177 } while (i != d0_idx);
1179 BUG_ON(faila == failb);
1182 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1183 __func__, (unsigned long long)sh->sector, faila, failb);
1185 atomic_inc(&sh->count);
1187 if (failb == syndrome_disks+1) {
1188 /* Q disk is one of the missing disks */
1189 if (faila == syndrome_disks) {
1190 /* Missing P+Q, just recompute */
1191 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1192 ops_complete_compute, sh,
1193 to_addr_conv(sh, percpu));
1194 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
1195 STRIPE_SIZE, &submit);
1199 int qd_idx = sh->qd_idx;
1201 /* Missing D+Q: recompute D from P, then recompute Q */
1202 if (target == qd_idx)
1203 data_target = target2;
1205 data_target = target;
1208 for (i = disks; i-- ; ) {
1209 if (i == data_target || i == qd_idx)
1211 blocks[count++] = sh->dev[i].page;
1213 dest = sh->dev[data_target].page;
1214 init_async_submit(&submit,
1215 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
1217 to_addr_conv(sh, percpu));
1218 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
1221 count = set_syndrome_sources(blocks, sh);
1222 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
1223 ops_complete_compute, sh,
1224 to_addr_conv(sh, percpu));
1225 return async_gen_syndrome(blocks, 0, count+2,
1226 STRIPE_SIZE, &submit);
1229 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
1230 ops_complete_compute, sh,
1231 to_addr_conv(sh, percpu));
1232 if (failb == syndrome_disks) {
1233 /* We're missing D+P. */
1234 return async_raid6_datap_recov(syndrome_disks+2,
1238 /* We're missing D+D. */
1239 return async_raid6_2data_recov(syndrome_disks+2,
1240 STRIPE_SIZE, faila, failb,
1247 static void ops_complete_prexor(void *stripe_head_ref)
1249 struct stripe_head *sh = stripe_head_ref;
1251 pr_debug("%s: stripe %llu\n", __func__,
1252 (unsigned long long)sh->sector);
1255 static struct dma_async_tx_descriptor *
1256 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
1257 struct dma_async_tx_descriptor *tx)
1259 int disks = sh->disks;
1260 struct page **xor_srcs = percpu->scribble;
1261 int count = 0, pd_idx = sh->pd_idx, i;
1262 struct async_submit_ctl submit;
1264 /* existing parity data subtracted */
1265 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1267 pr_debug("%s: stripe %llu\n", __func__,
1268 (unsigned long long)sh->sector);
1270 for (i = disks; i--; ) {
1271 struct r5dev *dev = &sh->dev[i];
1272 /* Only process blocks that are known to be uptodate */
1273 if (test_bit(R5_Wantdrain, &dev->flags))
1274 xor_srcs[count++] = dev->page;
1277 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1278 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
1279 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1284 static struct dma_async_tx_descriptor *
1285 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1287 int disks = sh->disks;
1290 pr_debug("%s: stripe %llu\n", __func__,
1291 (unsigned long long)sh->sector);
1293 for (i = disks; i--; ) {
1294 struct r5dev *dev = &sh->dev[i];
1297 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
1300 spin_lock_irq(&sh->stripe_lock);
1301 chosen = dev->towrite;
1302 dev->towrite = NULL;
1303 BUG_ON(dev->written);
1304 wbi = dev->written = chosen;
1305 spin_unlock_irq(&sh->stripe_lock);
1307 while (wbi && wbi->bi_sector <
1308 dev->sector + STRIPE_SECTORS) {
1309 if (wbi->bi_rw & REQ_FUA)
1310 set_bit(R5_WantFUA, &dev->flags);
1311 if (wbi->bi_rw & REQ_SYNC)
1312 set_bit(R5_SyncIO, &dev->flags);
1313 if (wbi->bi_rw & REQ_DISCARD)
1314 set_bit(R5_Discard, &dev->flags);
1316 tx = async_copy_data(1, wbi, dev->page,
1318 wbi = r5_next_bio(wbi, dev->sector);
1326 static void ops_complete_reconstruct(void *stripe_head_ref)
1328 struct stripe_head *sh = stripe_head_ref;
1329 int disks = sh->disks;
1330 int pd_idx = sh->pd_idx;
1331 int qd_idx = sh->qd_idx;
1333 bool fua = false, sync = false, discard = false;
1335 pr_debug("%s: stripe %llu\n", __func__,
1336 (unsigned long long)sh->sector);
1338 for (i = disks; i--; ) {
1339 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1340 sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
1341 discard |= test_bit(R5_Discard, &sh->dev[i].flags);
1344 for (i = disks; i--; ) {
1345 struct r5dev *dev = &sh->dev[i];
1347 if (dev->written || i == pd_idx || i == qd_idx) {
1349 set_bit(R5_UPTODATE, &dev->flags);
1351 set_bit(R5_WantFUA, &dev->flags);
1353 set_bit(R5_SyncIO, &dev->flags);
1357 if (sh->reconstruct_state == reconstruct_state_drain_run)
1358 sh->reconstruct_state = reconstruct_state_drain_result;
1359 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1360 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1362 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1363 sh->reconstruct_state = reconstruct_state_result;
1366 set_bit(STRIPE_HANDLE, &sh->state);
1371 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1372 struct dma_async_tx_descriptor *tx)
1374 int disks = sh->disks;
1375 struct page **xor_srcs = percpu->scribble;
1376 struct async_submit_ctl submit;
1377 int count = 0, pd_idx = sh->pd_idx, i;
1378 struct page *xor_dest;
1380 unsigned long flags;
1382 pr_debug("%s: stripe %llu\n", __func__,
1383 (unsigned long long)sh->sector);
1385 for (i = 0; i < sh->disks; i++) {
1388 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1391 if (i >= sh->disks) {
1392 atomic_inc(&sh->count);
1393 set_bit(R5_Discard, &sh->dev[pd_idx].flags);
1394 ops_complete_reconstruct(sh);
1397 /* check if prexor is active which means only process blocks
1398 * that are part of a read-modify-write (written)
1400 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1402 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1403 for (i = disks; i--; ) {
1404 struct r5dev *dev = &sh->dev[i];
1406 xor_srcs[count++] = dev->page;
1409 xor_dest = sh->dev[pd_idx].page;
1410 for (i = disks; i--; ) {
1411 struct r5dev *dev = &sh->dev[i];
1413 xor_srcs[count++] = dev->page;
1417 /* 1/ if we prexor'd then the dest is reused as a source
1418 * 2/ if we did not prexor then we are redoing the parity
1419 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1420 * for the synchronous xor case
1422 flags = ASYNC_TX_ACK |
1423 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1425 atomic_inc(&sh->count);
1427 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
1428 to_addr_conv(sh, percpu));
1429 if (unlikely(count == 1))
1430 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1432 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1436 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1437 struct dma_async_tx_descriptor *tx)
1439 struct async_submit_ctl submit;
1440 struct page **blocks = percpu->scribble;
1443 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1445 for (i = 0; i < sh->disks; i++) {
1446 if (sh->pd_idx == i || sh->qd_idx == i)
1448 if (!test_bit(R5_Discard, &sh->dev[i].flags))
1451 if (i >= sh->disks) {
1452 atomic_inc(&sh->count);
1453 set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
1454 set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
1455 ops_complete_reconstruct(sh);
1459 count = set_syndrome_sources(blocks, sh);
1461 atomic_inc(&sh->count);
1463 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1464 sh, to_addr_conv(sh, percpu));
1465 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1468 static void ops_complete_check(void *stripe_head_ref)
1470 struct stripe_head *sh = stripe_head_ref;
1472 pr_debug("%s: stripe %llu\n", __func__,
1473 (unsigned long long)sh->sector);
1475 sh->check_state = check_state_check_result;
1476 set_bit(STRIPE_HANDLE, &sh->state);
1480 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1482 int disks = sh->disks;
1483 int pd_idx = sh->pd_idx;
1484 int qd_idx = sh->qd_idx;
1485 struct page *xor_dest;
1486 struct page **xor_srcs = percpu->scribble;
1487 struct dma_async_tx_descriptor *tx;
1488 struct async_submit_ctl submit;
1492 pr_debug("%s: stripe %llu\n", __func__,
1493 (unsigned long long)sh->sector);
1496 xor_dest = sh->dev[pd_idx].page;
1497 xor_srcs[count++] = xor_dest;
1498 for (i = disks; i--; ) {
1499 if (i == pd_idx || i == qd_idx)
1501 xor_srcs[count++] = sh->dev[i].page;
1504 init_async_submit(&submit, 0, NULL, NULL, NULL,
1505 to_addr_conv(sh, percpu));
1506 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1507 &sh->ops.zero_sum_result, &submit);
1509 atomic_inc(&sh->count);
1510 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1511 tx = async_trigger_callback(&submit);
1514 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1516 struct page **srcs = percpu->scribble;
1517 struct async_submit_ctl submit;
1520 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1521 (unsigned long long)sh->sector, checkp);
1523 count = set_syndrome_sources(srcs, sh);
1527 atomic_inc(&sh->count);
1528 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1529 sh, to_addr_conv(sh, percpu));
1530 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1531 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1534 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1536 int overlap_clear = 0, i, disks = sh->disks;
1537 struct dma_async_tx_descriptor *tx = NULL;
1538 struct r5conf *conf = sh->raid_conf;
1539 int level = conf->level;
1540 struct raid5_percpu *percpu;
1544 percpu = per_cpu_ptr(conf->percpu, cpu);
1545 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1546 ops_run_biofill(sh);
1550 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1552 tx = ops_run_compute5(sh, percpu);
1554 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1555 tx = ops_run_compute6_1(sh, percpu);
1557 tx = ops_run_compute6_2(sh, percpu);
1559 /* terminate the chain if reconstruct is not set to be run */
1560 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1564 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
1565 tx = ops_run_prexor(sh, percpu, tx);
1567 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1568 tx = ops_run_biodrain(sh, tx);
1572 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1574 ops_run_reconstruct5(sh, percpu, tx);
1576 ops_run_reconstruct6(sh, percpu, tx);
1579 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1580 if (sh->check_state == check_state_run)
1581 ops_run_check_p(sh, percpu);
1582 else if (sh->check_state == check_state_run_q)
1583 ops_run_check_pq(sh, percpu, 0);
1584 else if (sh->check_state == check_state_run_pq)
1585 ops_run_check_pq(sh, percpu, 1);
1591 for (i = disks; i--; ) {
1592 struct r5dev *dev = &sh->dev[i];
1593 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1594 wake_up(&sh->raid_conf->wait_for_overlap);
1599 static int grow_one_stripe(struct r5conf *conf)
1601 struct stripe_head *sh;
1602 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
1606 sh->raid_conf = conf;
1608 spin_lock_init(&sh->stripe_lock);
1610 if (grow_buffers(sh)) {
1612 kmem_cache_free(conf->slab_cache, sh);
1615 /* we just created an active stripe so... */
1616 atomic_set(&sh->count, 1);
1617 atomic_inc(&conf->active_stripes);
1618 INIT_LIST_HEAD(&sh->lru);
1623 static int grow_stripes(struct r5conf *conf, int num)
1625 struct kmem_cache *sc;
1626 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1628 if (conf->mddev->gendisk)
1629 sprintf(conf->cache_name[0],
1630 "raid%d-%s", conf->level, mdname(conf->mddev));
1632 sprintf(conf->cache_name[0],
1633 "raid%d-%p", conf->level, conf->mddev);
1634 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1636 conf->active_name = 0;
1637 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1638 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
1642 conf->slab_cache = sc;
1643 conf->pool_size = devs;
1645 if (!grow_one_stripe(conf))
1651 * scribble_len - return the required size of the scribble region
1652 * @num - total number of disks in the array
1654 * The size must be enough to contain:
1655 * 1/ a struct page pointer for each device in the array +2
1656 * 2/ room to convert each entry in (1) to its corresponding dma
1657 * (dma_map_page()) or page (page_address()) address.
1659 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1660 * calculate over all devices (not just the data blocks), using zeros in place
1661 * of the P and Q blocks.
1663 static size_t scribble_len(int num)
1667 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1672 static int resize_stripes(struct r5conf *conf, int newsize)
1674 /* Make all the stripes able to hold 'newsize' devices.
1675 * New slots in each stripe get 'page' set to a new page.
1677 * This happens in stages:
1678 * 1/ create a new kmem_cache and allocate the required number of
1680 * 2/ gather all the old stripe_heads and transfer the pages across
1681 * to the new stripe_heads. This will have the side effect of
1682 * freezing the array as once all stripe_heads have been collected,
1683 * no IO will be possible. Old stripe heads are freed once their
1684 * pages have been transferred over, and the old kmem_cache is
1685 * freed when all stripes are done.
1686 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1687 * we simple return a failre status - no need to clean anything up.
1688 * 4/ allocate new pages for the new slots in the new stripe_heads.
1689 * If this fails, we don't bother trying the shrink the
1690 * stripe_heads down again, we just leave them as they are.
1691 * As each stripe_head is processed the new one is released into
1694 * Once step2 is started, we cannot afford to wait for a write,
1695 * so we use GFP_NOIO allocations.
1697 struct stripe_head *osh, *nsh;
1698 LIST_HEAD(newstripes);
1699 struct disk_info *ndisks;
1702 struct kmem_cache *sc;
1705 if (newsize <= conf->pool_size)
1706 return 0; /* never bother to shrink */
1708 err = md_allow_write(conf->mddev);
1713 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1714 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
1719 for (i = conf->max_nr_stripes; i; i--) {
1720 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
1724 nsh->raid_conf = conf;
1725 spin_lock_init(&nsh->stripe_lock);
1727 list_add(&nsh->lru, &newstripes);
1730 /* didn't get enough, give up */
1731 while (!list_empty(&newstripes)) {
1732 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1733 list_del(&nsh->lru);
1734 kmem_cache_free(sc, nsh);
1736 kmem_cache_destroy(sc);
1739 /* Step 2 - Must use GFP_NOIO now.
1740 * OK, we have enough stripes, start collecting inactive
1741 * stripes and copying them over
1743 list_for_each_entry(nsh, &newstripes, lru) {
1744 spin_lock_irq(&conf->device_lock);
1745 wait_event_lock_irq(conf->wait_for_stripe,
1746 !list_empty(&conf->inactive_list),
1748 osh = get_free_stripe(conf);
1749 spin_unlock_irq(&conf->device_lock);
1750 atomic_set(&nsh->count, 1);
1751 for(i=0; i<conf->pool_size; i++)
1752 nsh->dev[i].page = osh->dev[i].page;
1753 for( ; i<newsize; i++)
1754 nsh->dev[i].page = NULL;
1755 kmem_cache_free(conf->slab_cache, osh);
1757 kmem_cache_destroy(conf->slab_cache);
1760 * At this point, we are holding all the stripes so the array
1761 * is completely stalled, so now is a good time to resize
1762 * conf->disks and the scribble region
1764 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1766 for (i=0; i<conf->raid_disks; i++)
1767 ndisks[i] = conf->disks[i];
1769 conf->disks = ndisks;
1774 conf->scribble_len = scribble_len(newsize);
1775 for_each_present_cpu(cpu) {
1776 struct raid5_percpu *percpu;
1779 percpu = per_cpu_ptr(conf->percpu, cpu);
1780 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1783 kfree(percpu->scribble);
1784 percpu->scribble = scribble;
1792 /* Step 4, return new stripes to service */
1793 while(!list_empty(&newstripes)) {
1794 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1795 list_del_init(&nsh->lru);
1797 for (i=conf->raid_disks; i < newsize; i++)
1798 if (nsh->dev[i].page == NULL) {
1799 struct page *p = alloc_page(GFP_NOIO);
1800 nsh->dev[i].page = p;
1804 release_stripe(nsh);
1806 /* critical section pass, GFP_NOIO no longer needed */
1808 conf->slab_cache = sc;
1809 conf->active_name = 1-conf->active_name;
1810 conf->pool_size = newsize;
1814 static int drop_one_stripe(struct r5conf *conf)
1816 struct stripe_head *sh;
1818 spin_lock_irq(&conf->device_lock);
1819 sh = get_free_stripe(conf);
1820 spin_unlock_irq(&conf->device_lock);
1823 BUG_ON(atomic_read(&sh->count));
1825 kmem_cache_free(conf->slab_cache, sh);
1826 atomic_dec(&conf->active_stripes);
1830 static void shrink_stripes(struct r5conf *conf)
1832 while (drop_one_stripe(conf))
1835 if (conf->slab_cache)
1836 kmem_cache_destroy(conf->slab_cache);
1837 conf->slab_cache = NULL;
1840 static void raid5_end_read_request(struct bio * bi, int error)
1842 struct stripe_head *sh = bi->bi_private;
1843 struct r5conf *conf = sh->raid_conf;
1844 int disks = sh->disks, i;
1845 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1846 char b[BDEVNAME_SIZE];
1847 struct md_rdev *rdev = NULL;
1850 for (i=0 ; i<disks; i++)
1851 if (bi == &sh->dev[i].req)
1854 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1855 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1861 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
1862 /* If replacement finished while this request was outstanding,
1863 * 'replacement' might be NULL already.
1864 * In that case it moved down to 'rdev'.
1865 * rdev is not removed until all requests are finished.
1867 rdev = conf->disks[i].replacement;
1869 rdev = conf->disks[i].rdev;
1871 if (use_new_offset(conf, sh))
1872 s = sh->sector + rdev->new_data_offset;
1874 s = sh->sector + rdev->data_offset;
1876 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1877 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1878 /* Note that this cannot happen on a
1879 * replacement device. We just fail those on
1884 "md/raid:%s: read error corrected"
1885 " (%lu sectors at %llu on %s)\n",
1886 mdname(conf->mddev), STRIPE_SECTORS,
1887 (unsigned long long)s,
1888 bdevname(rdev->bdev, b));
1889 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
1890 clear_bit(R5_ReadError, &sh->dev[i].flags);
1891 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1892 } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
1893 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1895 if (atomic_read(&rdev->read_errors))
1896 atomic_set(&rdev->read_errors, 0);
1898 const char *bdn = bdevname(rdev->bdev, b);
1902 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1903 atomic_inc(&rdev->read_errors);
1904 if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
1907 "md/raid:%s: read error on replacement device "
1908 "(sector %llu on %s).\n",
1909 mdname(conf->mddev),
1910 (unsigned long long)s,
1912 else if (conf->mddev->degraded >= conf->max_degraded) {
1916 "md/raid:%s: read error not correctable "
1917 "(sector %llu on %s).\n",
1918 mdname(conf->mddev),
1919 (unsigned long long)s,
1921 } else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
1926 "md/raid:%s: read error NOT corrected!! "
1927 "(sector %llu on %s).\n",
1928 mdname(conf->mddev),
1929 (unsigned long long)s,
1931 } else if (atomic_read(&rdev->read_errors)
1932 > conf->max_nr_stripes)
1934 "md/raid:%s: Too many read errors, failing device %s.\n",
1935 mdname(conf->mddev), bdn);
1939 if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
1940 set_bit(R5_ReadError, &sh->dev[i].flags);
1941 clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1943 set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
1945 clear_bit(R5_ReadError, &sh->dev[i].flags);
1946 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1948 && test_bit(In_sync, &rdev->flags)
1949 && rdev_set_badblocks(
1950 rdev, sh->sector, STRIPE_SECTORS, 0)))
1951 md_error(conf->mddev, rdev);
1954 rdev_dec_pending(rdev, conf->mddev);
1955 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1956 set_bit(STRIPE_HANDLE, &sh->state);
1960 static void raid5_end_write_request(struct bio *bi, int error)
1962 struct stripe_head *sh = bi->bi_private;
1963 struct r5conf *conf = sh->raid_conf;
1964 int disks = sh->disks, i;
1965 struct md_rdev *uninitialized_var(rdev);
1966 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1969 int replacement = 0;
1971 for (i = 0 ; i < disks; i++) {
1972 if (bi == &sh->dev[i].req) {
1973 rdev = conf->disks[i].rdev;
1976 if (bi == &sh->dev[i].rreq) {
1977 rdev = conf->disks[i].replacement;
1981 /* rdev was removed and 'replacement'
1982 * replaced it. rdev is not removed
1983 * until all requests are finished.
1985 rdev = conf->disks[i].rdev;
1989 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1990 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1999 md_error(conf->mddev, rdev);
2000 else if (is_badblock(rdev, sh->sector,
2002 &first_bad, &bad_sectors))
2003 set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
2006 set_bit(WriteErrorSeen, &rdev->flags);
2007 set_bit(R5_WriteError, &sh->dev[i].flags);
2008 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2009 set_bit(MD_RECOVERY_NEEDED,
2010 &rdev->mddev->recovery);
2011 } else if (is_badblock(rdev, sh->sector,
2013 &first_bad, &bad_sectors)) {
2014 set_bit(R5_MadeGood, &sh->dev[i].flags);
2015 if (test_bit(R5_ReadError, &sh->dev[i].flags))
2016 /* That was a successful write so make
2017 * sure it looks like we already did
2020 set_bit(R5_ReWrite, &sh->dev[i].flags);
2023 rdev_dec_pending(rdev, conf->mddev);
2025 if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
2026 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2027 set_bit(STRIPE_HANDLE, &sh->state);
2031 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
2033 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
2035 struct r5dev *dev = &sh->dev[i];
2037 bio_init(&dev->req);
2038 dev->req.bi_io_vec = &dev->vec;
2040 dev->req.bi_max_vecs++;
2041 dev->req.bi_private = sh;
2042 dev->vec.bv_page = dev->page;
2044 bio_init(&dev->rreq);
2045 dev->rreq.bi_io_vec = &dev->rvec;
2046 dev->rreq.bi_vcnt++;
2047 dev->rreq.bi_max_vecs++;
2048 dev->rreq.bi_private = sh;
2049 dev->rvec.bv_page = dev->page;
2052 dev->sector = compute_blocknr(sh, i, previous);
2055 static void error(struct mddev *mddev, struct md_rdev *rdev)
2057 char b[BDEVNAME_SIZE];
2058 struct r5conf *conf = mddev->private;
2059 unsigned long flags;
2060 pr_debug("raid456: error called\n");
2062 spin_lock_irqsave(&conf->device_lock, flags);
2063 clear_bit(In_sync, &rdev->flags);
2064 mddev->degraded = calc_degraded(conf);
2065 spin_unlock_irqrestore(&conf->device_lock, flags);
2066 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2068 set_bit(Blocked, &rdev->flags);
2069 set_bit(Faulty, &rdev->flags);
2070 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2072 "md/raid:%s: Disk failure on %s, disabling device.\n"
2073 "md/raid:%s: Operation continuing on %d devices.\n",
2075 bdevname(rdev->bdev, b),
2077 conf->raid_disks - mddev->degraded);
2081 * Input: a 'big' sector number,
2082 * Output: index of the data and parity disk, and the sector # in them.
2084 static sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
2085 int previous, int *dd_idx,
2086 struct stripe_head *sh)
2088 sector_t stripe, stripe2;
2089 sector_t chunk_number;
2090 unsigned int chunk_offset;
2093 sector_t new_sector;
2094 int algorithm = previous ? conf->prev_algo
2096 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2097 : conf->chunk_sectors;
2098 int raid_disks = previous ? conf->previous_raid_disks
2100 int data_disks = raid_disks - conf->max_degraded;
2102 /* First compute the information on this sector */
2105 * Compute the chunk number and the sector offset inside the chunk
2107 chunk_offset = sector_div(r_sector, sectors_per_chunk);
2108 chunk_number = r_sector;
2111 * Compute the stripe number
2113 stripe = chunk_number;
2114 *dd_idx = sector_div(stripe, data_disks);
2117 * Select the parity disk based on the user selected algorithm.
2119 pd_idx = qd_idx = -1;
2120 switch(conf->level) {
2122 pd_idx = data_disks;
2125 switch (algorithm) {
2126 case ALGORITHM_LEFT_ASYMMETRIC:
2127 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2128 if (*dd_idx >= pd_idx)
2131 case ALGORITHM_RIGHT_ASYMMETRIC:
2132 pd_idx = sector_div(stripe2, raid_disks);
2133 if (*dd_idx >= pd_idx)
2136 case ALGORITHM_LEFT_SYMMETRIC:
2137 pd_idx = data_disks - sector_div(stripe2, raid_disks);
2138 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2140 case ALGORITHM_RIGHT_SYMMETRIC:
2141 pd_idx = sector_div(stripe2, raid_disks);
2142 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2144 case ALGORITHM_PARITY_0:
2148 case ALGORITHM_PARITY_N:
2149 pd_idx = data_disks;
2157 switch (algorithm) {
2158 case ALGORITHM_LEFT_ASYMMETRIC:
2159 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2160 qd_idx = pd_idx + 1;
2161 if (pd_idx == raid_disks-1) {
2162 (*dd_idx)++; /* Q D D D P */
2164 } else if (*dd_idx >= pd_idx)
2165 (*dd_idx) += 2; /* D D P Q D */
2167 case ALGORITHM_RIGHT_ASYMMETRIC:
2168 pd_idx = sector_div(stripe2, raid_disks);
2169 qd_idx = pd_idx + 1;
2170 if (pd_idx == raid_disks-1) {
2171 (*dd_idx)++; /* Q D D D P */
2173 } else if (*dd_idx >= pd_idx)
2174 (*dd_idx) += 2; /* D D P Q D */
2176 case ALGORITHM_LEFT_SYMMETRIC:
2177 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2178 qd_idx = (pd_idx + 1) % raid_disks;
2179 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2181 case ALGORITHM_RIGHT_SYMMETRIC:
2182 pd_idx = sector_div(stripe2, raid_disks);
2183 qd_idx = (pd_idx + 1) % raid_disks;
2184 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
2187 case ALGORITHM_PARITY_0:
2192 case ALGORITHM_PARITY_N:
2193 pd_idx = data_disks;
2194 qd_idx = data_disks + 1;
2197 case ALGORITHM_ROTATING_ZERO_RESTART:
2198 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2199 * of blocks for computing Q is different.
2201 pd_idx = sector_div(stripe2, raid_disks);
2202 qd_idx = pd_idx + 1;
2203 if (pd_idx == raid_disks-1) {
2204 (*dd_idx)++; /* Q D D D P */
2206 } else if (*dd_idx >= pd_idx)
2207 (*dd_idx) += 2; /* D D P Q D */
2211 case ALGORITHM_ROTATING_N_RESTART:
2212 /* Same a left_asymmetric, by first stripe is
2213 * D D D P Q rather than
2217 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2218 qd_idx = pd_idx + 1;
2219 if (pd_idx == raid_disks-1) {
2220 (*dd_idx)++; /* Q D D D P */
2222 } else if (*dd_idx >= pd_idx)
2223 (*dd_idx) += 2; /* D D P Q D */
2227 case ALGORITHM_ROTATING_N_CONTINUE:
2228 /* Same as left_symmetric but Q is before P */
2229 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
2230 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
2231 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
2235 case ALGORITHM_LEFT_ASYMMETRIC_6:
2236 /* RAID5 left_asymmetric, with Q on last device */
2237 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2238 if (*dd_idx >= pd_idx)
2240 qd_idx = raid_disks - 1;
2243 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2244 pd_idx = sector_div(stripe2, raid_disks-1);
2245 if (*dd_idx >= pd_idx)
2247 qd_idx = raid_disks - 1;
2250 case ALGORITHM_LEFT_SYMMETRIC_6:
2251 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
2252 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2253 qd_idx = raid_disks - 1;
2256 case ALGORITHM_RIGHT_SYMMETRIC_6:
2257 pd_idx = sector_div(stripe2, raid_disks-1);
2258 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
2259 qd_idx = raid_disks - 1;
2262 case ALGORITHM_PARITY_0_6:
2265 qd_idx = raid_disks - 1;
2275 sh->pd_idx = pd_idx;
2276 sh->qd_idx = qd_idx;
2277 sh->ddf_layout = ddf_layout;
2280 * Finally, compute the new sector number
2282 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
2287 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
2289 struct r5conf *conf = sh->raid_conf;
2290 int raid_disks = sh->disks;
2291 int data_disks = raid_disks - conf->max_degraded;
2292 sector_t new_sector = sh->sector, check;
2293 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
2294 : conf->chunk_sectors;
2295 int algorithm = previous ? conf->prev_algo
2299 sector_t chunk_number;
2300 int dummy1, dd_idx = i;
2302 struct stripe_head sh2;
2305 chunk_offset = sector_div(new_sector, sectors_per_chunk);
2306 stripe = new_sector;
2308 if (i == sh->pd_idx)
2310 switch(conf->level) {
2313 switch (algorithm) {
2314 case ALGORITHM_LEFT_ASYMMETRIC:
2315 case ALGORITHM_RIGHT_ASYMMETRIC:
2319 case ALGORITHM_LEFT_SYMMETRIC:
2320 case ALGORITHM_RIGHT_SYMMETRIC:
2323 i -= (sh->pd_idx + 1);
2325 case ALGORITHM_PARITY_0:
2328 case ALGORITHM_PARITY_N:
2335 if (i == sh->qd_idx)
2336 return 0; /* It is the Q disk */
2337 switch (algorithm) {
2338 case ALGORITHM_LEFT_ASYMMETRIC:
2339 case ALGORITHM_RIGHT_ASYMMETRIC:
2340 case ALGORITHM_ROTATING_ZERO_RESTART:
2341 case ALGORITHM_ROTATING_N_RESTART:
2342 if (sh->pd_idx == raid_disks-1)
2343 i--; /* Q D D D P */
2344 else if (i > sh->pd_idx)
2345 i -= 2; /* D D P Q D */
2347 case ALGORITHM_LEFT_SYMMETRIC:
2348 case ALGORITHM_RIGHT_SYMMETRIC:
2349 if (sh->pd_idx == raid_disks-1)
2350 i--; /* Q D D D P */
2355 i -= (sh->pd_idx + 2);
2358 case ALGORITHM_PARITY_0:
2361 case ALGORITHM_PARITY_N:
2363 case ALGORITHM_ROTATING_N_CONTINUE:
2364 /* Like left_symmetric, but P is before Q */
2365 if (sh->pd_idx == 0)
2366 i--; /* P D D D Q */
2371 i -= (sh->pd_idx + 1);
2374 case ALGORITHM_LEFT_ASYMMETRIC_6:
2375 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2379 case ALGORITHM_LEFT_SYMMETRIC_6:
2380 case ALGORITHM_RIGHT_SYMMETRIC_6:
2382 i += data_disks + 1;
2383 i -= (sh->pd_idx + 1);
2385 case ALGORITHM_PARITY_0_6:
2394 chunk_number = stripe * data_disks + i;
2395 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2397 check = raid5_compute_sector(conf, r_sector,
2398 previous, &dummy1, &sh2);
2399 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2400 || sh2.qd_idx != sh->qd_idx) {
2401 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2402 mdname(conf->mddev));
2410 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2411 int rcw, int expand)
2413 int i, pd_idx = sh->pd_idx, disks = sh->disks;
2414 struct r5conf *conf = sh->raid_conf;
2415 int level = conf->level;
2419 for (i = disks; i--; ) {
2420 struct r5dev *dev = &sh->dev[i];
2423 set_bit(R5_LOCKED, &dev->flags);
2424 set_bit(R5_Wantdrain, &dev->flags);
2426 clear_bit(R5_UPTODATE, &dev->flags);
2430 /* if we are not expanding this is a proper write request, and
2431 * there will be bios with new data to be drained into the
2436 /* False alarm, nothing to do */
2438 sh->reconstruct_state = reconstruct_state_drain_run;
2439 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2441 sh->reconstruct_state = reconstruct_state_run;
2443 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2445 if (s->locked + conf->max_degraded == disks)
2446 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2447 atomic_inc(&conf->pending_full_writes);
2450 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2451 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2453 for (i = disks; i--; ) {
2454 struct r5dev *dev = &sh->dev[i];
2459 (test_bit(R5_UPTODATE, &dev->flags) ||
2460 test_bit(R5_Wantcompute, &dev->flags))) {
2461 set_bit(R5_Wantdrain, &dev->flags);
2462 set_bit(R5_LOCKED, &dev->flags);
2463 clear_bit(R5_UPTODATE, &dev->flags);
2468 /* False alarm - nothing to do */
2470 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2471 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2472 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2473 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2476 /* keep the parity disk(s) locked while asynchronous operations
2479 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2480 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2484 int qd_idx = sh->qd_idx;
2485 struct r5dev *dev = &sh->dev[qd_idx];
2487 set_bit(R5_LOCKED, &dev->flags);
2488 clear_bit(R5_UPTODATE, &dev->flags);
2492 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2493 __func__, (unsigned long long)sh->sector,
2494 s->locked, s->ops_request);
2498 * Each stripe/dev can have one or more bion attached.
2499 * toread/towrite point to the first in a chain.
2500 * The bi_next chain must be in order.
2502 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2505 struct r5conf *conf = sh->raid_conf;
2508 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2509 (unsigned long long)bi->bi_sector,
2510 (unsigned long long)sh->sector);
2513 * If several bio share a stripe. The bio bi_phys_segments acts as a
2514 * reference count to avoid race. The reference count should already be
2515 * increased before this function is called (for example, in
2516 * make_request()), so other bio sharing this stripe will not free the
2517 * stripe. If a stripe is owned by one stripe, the stripe lock will
2520 spin_lock_irq(&sh->stripe_lock);
2522 bip = &sh->dev[dd_idx].towrite;
2526 bip = &sh->dev[dd_idx].toread;
2527 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2528 if (bio_end_sector(*bip) > bi->bi_sector)
2530 bip = & (*bip)->bi_next;
2532 if (*bip && (*bip)->bi_sector < bio_end_sector(bi))
2535 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2539 raid5_inc_bi_active_stripes(bi);
2542 /* check if page is covered */
2543 sector_t sector = sh->dev[dd_idx].sector;
2544 for (bi=sh->dev[dd_idx].towrite;
2545 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2546 bi && bi->bi_sector <= sector;
2547 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2548 if (bio_end_sector(bi) >= sector)
2549 sector = bio_end_sector(bi);
2551 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2552 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2555 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2556 (unsigned long long)(*bip)->bi_sector,
2557 (unsigned long long)sh->sector, dd_idx);
2558 spin_unlock_irq(&sh->stripe_lock);
2560 if (conf->mddev->bitmap && firstwrite) {
2561 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2563 sh->bm_seq = conf->seq_flush+1;
2564 set_bit(STRIPE_BIT_DELAY, &sh->state);
2569 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2570 spin_unlock_irq(&sh->stripe_lock);
2574 static void end_reshape(struct r5conf *conf);
2576 static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
2577 struct stripe_head *sh)
2579 int sectors_per_chunk =
2580 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
2582 int chunk_offset = sector_div(stripe, sectors_per_chunk);
2583 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2585 raid5_compute_sector(conf,
2586 stripe * (disks - conf->max_degraded)
2587 *sectors_per_chunk + chunk_offset,
2593 handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
2594 struct stripe_head_state *s, int disks,
2595 struct bio **return_bi)
2598 for (i = disks; i--; ) {
2602 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2603 struct md_rdev *rdev;
2605 rdev = rcu_dereference(conf->disks[i].rdev);
2606 if (rdev && test_bit(In_sync, &rdev->flags))
2607 atomic_inc(&rdev->nr_pending);
2612 if (!rdev_set_badblocks(
2616 md_error(conf->mddev, rdev);
2617 rdev_dec_pending(rdev, conf->mddev);
2620 spin_lock_irq(&sh->stripe_lock);
2621 /* fail all writes first */
2622 bi = sh->dev[i].towrite;
2623 sh->dev[i].towrite = NULL;
2624 spin_unlock_irq(&sh->stripe_lock);
2628 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2629 wake_up(&conf->wait_for_overlap);
2631 while (bi && bi->bi_sector <
2632 sh->dev[i].sector + STRIPE_SECTORS) {
2633 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2634 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2635 if (!raid5_dec_bi_active_stripes(bi)) {
2636 md_write_end(conf->mddev);
2637 bi->bi_next = *return_bi;
2643 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2644 STRIPE_SECTORS, 0, 0);
2646 /* and fail all 'written' */
2647 bi = sh->dev[i].written;
2648 sh->dev[i].written = NULL;
2649 if (bi) bitmap_end = 1;
2650 while (bi && bi->bi_sector <
2651 sh->dev[i].sector + STRIPE_SECTORS) {
2652 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2653 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2654 if (!raid5_dec_bi_active_stripes(bi)) {
2655 md_write_end(conf->mddev);
2656 bi->bi_next = *return_bi;
2662 /* fail any reads if this device is non-operational and
2663 * the data has not reached the cache yet.
2665 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2666 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2667 test_bit(R5_ReadError, &sh->dev[i].flags))) {
2668 spin_lock_irq(&sh->stripe_lock);
2669 bi = sh->dev[i].toread;
2670 sh->dev[i].toread = NULL;
2671 spin_unlock_irq(&sh->stripe_lock);
2672 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2673 wake_up(&conf->wait_for_overlap);
2674 while (bi && bi->bi_sector <
2675 sh->dev[i].sector + STRIPE_SECTORS) {
2676 struct bio *nextbi =
2677 r5_next_bio(bi, sh->dev[i].sector);
2678 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2679 if (!raid5_dec_bi_active_stripes(bi)) {
2680 bi->bi_next = *return_bi;
2687 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2688 STRIPE_SECTORS, 0, 0);
2689 /* If we were in the middle of a write the parity block might
2690 * still be locked - so just clear all R5_LOCKED flags
2692 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2695 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2696 if (atomic_dec_and_test(&conf->pending_full_writes))
2697 md_wakeup_thread(conf->mddev->thread);
2701 handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
2702 struct stripe_head_state *s)
2707 clear_bit(STRIPE_SYNCING, &sh->state);
2708 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
2709 wake_up(&conf->wait_for_overlap);
2712 /* There is nothing more to do for sync/check/repair.
2713 * Don't even need to abort as that is handled elsewhere
2714 * if needed, and not always wanted e.g. if there is a known
2716 * For recover/replace we need to record a bad block on all
2717 * non-sync devices, or abort the recovery
2719 if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
2720 /* During recovery devices cannot be removed, so
2721 * locking and refcounting of rdevs is not needed
2723 for (i = 0; i < conf->raid_disks; i++) {
2724 struct md_rdev *rdev = conf->disks[i].rdev;
2726 && !test_bit(Faulty, &rdev->flags)
2727 && !test_bit(In_sync, &rdev->flags)
2728 && !rdev_set_badblocks(rdev, sh->sector,
2731 rdev = conf->disks[i].replacement;
2733 && !test_bit(Faulty, &rdev->flags)
2734 && !test_bit(In_sync, &rdev->flags)
2735 && !rdev_set_badblocks(rdev, sh->sector,
2740 conf->recovery_disabled =
2741 conf->mddev->recovery_disabled;
2743 md_done_sync(conf->mddev, STRIPE_SECTORS, !abort);
2746 static int want_replace(struct stripe_head *sh, int disk_idx)
2748 struct md_rdev *rdev;
2750 /* Doing recovery so rcu locking not required */
2751 rdev = sh->raid_conf->disks[disk_idx].replacement;
2753 && !test_bit(Faulty, &rdev->flags)
2754 && !test_bit(In_sync, &rdev->flags)
2755 && (rdev->recovery_offset <= sh->sector
2756 || rdev->mddev->recovery_cp <= sh->sector))
2762 /* fetch_block - checks the given member device to see if its data needs
2763 * to be read or computed to satisfy a request.
2765 * Returns 1 when no more member devices need to be checked, otherwise returns
2766 * 0 to tell the loop in handle_stripe_fill to continue
2768 static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
2769 int disk_idx, int disks)
2771 struct r5dev *dev = &sh->dev[disk_idx];
2772 struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
2773 &sh->dev[s->failed_num[1]] };
2775 /* is the data in this block needed, and can we get it? */
2776 if (!test_bit(R5_LOCKED, &dev->flags) &&
2777 !test_bit(R5_UPTODATE, &dev->flags) &&
2779 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2780 s->syncing || s->expanding ||
2781 (s->replacing && want_replace(sh, disk_idx)) ||
2782 (s->failed >= 1 && fdev[0]->toread) ||
2783 (s->failed >= 2 && fdev[1]->toread) ||
2784 (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
2785 !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
2786 (sh->raid_conf->level == 6 && s->failed && s->to_write))) {
2787 /* we would like to get this block, possibly by computing it,
2788 * otherwise read it if the backing disk is insync
2790 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2791 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2792 if ((s->uptodate == disks - 1) &&
2793 (s->failed && (disk_idx == s->failed_num[0] ||
2794 disk_idx == s->failed_num[1]))) {
2795 /* have disk failed, and we're requested to fetch it;
2798 pr_debug("Computing stripe %llu block %d\n",
2799 (unsigned long long)sh->sector, disk_idx);
2800 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2801 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2802 set_bit(R5_Wantcompute, &dev->flags);
2803 sh->ops.target = disk_idx;
2804 sh->ops.target2 = -1; /* no 2nd target */
2806 /* Careful: from this point on 'uptodate' is in the eye
2807 * of raid_run_ops which services 'compute' operations
2808 * before writes. R5_Wantcompute flags a block that will
2809 * be R5_UPTODATE by the time it is needed for a
2810 * subsequent operation.
2814 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2815 /* Computing 2-failure is *very* expensive; only
2816 * do it if failed >= 2
2819 for (other = disks; other--; ) {
2820 if (other == disk_idx)
2822 if (!test_bit(R5_UPTODATE,
2823 &sh->dev[other].flags))
2827 pr_debug("Computing stripe %llu blocks %d,%d\n",
2828 (unsigned long long)sh->sector,
2830 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2831 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2832 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2833 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2834 sh->ops.target = disk_idx;
2835 sh->ops.target2 = other;
2839 } else if (test_bit(R5_Insync, &dev->flags)) {
2840 set_bit(R5_LOCKED, &dev->flags);
2841 set_bit(R5_Wantread, &dev->flags);
2843 pr_debug("Reading block %d (sync=%d)\n",
2844 disk_idx, s->syncing);
2852 * handle_stripe_fill - read or compute data to satisfy pending requests.
2854 static void handle_stripe_fill(struct stripe_head *sh,
2855 struct stripe_head_state *s,
2860 /* look for blocks to read/compute, skip this if a compute
2861 * is already in flight, or if the stripe contents are in the
2862 * midst of changing due to a write
2864 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2865 !sh->reconstruct_state)
2866 for (i = disks; i--; )
2867 if (fetch_block(sh, s, i, disks))
2869 set_bit(STRIPE_HANDLE, &sh->state);
2873 /* handle_stripe_clean_event
2874 * any written block on an uptodate or failed drive can be returned.
2875 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2876 * never LOCKED, so we don't need to test 'failed' directly.
2878 static void handle_stripe_clean_event(struct r5conf *conf,
2879 struct stripe_head *sh, int disks, struct bio **return_bi)
2883 int discard_pending = 0;
2885 for (i = disks; i--; )
2886 if (sh->dev[i].written) {
2888 if (!test_bit(R5_LOCKED, &dev->flags) &&
2889 (test_bit(R5_UPTODATE, &dev->flags) ||
2890 test_bit(R5_Discard, &dev->flags))) {
2891 /* We can return any write requests */
2892 struct bio *wbi, *wbi2;
2893 pr_debug("Return write for disc %d\n", i);
2894 if (test_and_clear_bit(R5_Discard, &dev->flags))
2895 clear_bit(R5_UPTODATE, &dev->flags);
2897 dev->written = NULL;
2898 while (wbi && wbi->bi_sector <
2899 dev->sector + STRIPE_SECTORS) {
2900 wbi2 = r5_next_bio(wbi, dev->sector);
2901 if (!raid5_dec_bi_active_stripes(wbi)) {
2902 md_write_end(conf->mddev);
2903 wbi->bi_next = *return_bi;
2908 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2910 !test_bit(STRIPE_DEGRADED, &sh->state),
2912 } else if (test_bit(R5_Discard, &dev->flags))
2913 discard_pending = 1;
2915 if (!discard_pending &&
2916 test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
2917 clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
2918 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2919 if (sh->qd_idx >= 0) {
2920 clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
2921 clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
2923 /* now that discard is done we can proceed with any sync */
2924 clear_bit(STRIPE_DISCARD, &sh->state);
2926 * SCSI discard will change some bio fields and the stripe has
2927 * no updated data, so remove it from hash list and the stripe
2928 * will be reinitialized
2930 spin_lock_irq(&conf->device_lock);
2932 spin_unlock_irq(&conf->device_lock);
2933 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
2934 set_bit(STRIPE_HANDLE, &sh->state);
2938 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2939 if (atomic_dec_and_test(&conf->pending_full_writes))
2940 md_wakeup_thread(conf->mddev->thread);
2943 static void handle_stripe_dirtying(struct r5conf *conf,
2944 struct stripe_head *sh,
2945 struct stripe_head_state *s,
2948 int rmw = 0, rcw = 0, i;
2949 sector_t recovery_cp = conf->mddev->recovery_cp;
2951 /* RAID6 requires 'rcw' in current implementation.
2952 * Otherwise, check whether resync is now happening or should start.
2953 * If yes, then the array is dirty (after unclean shutdown or
2954 * initial creation), so parity in some stripes might be inconsistent.
2955 * In this case, we need to always do reconstruct-write, to ensure
2956 * that in case of drive failure or read-error correction, we
2957 * generate correct data from the parity.
2959 if (conf->max_degraded == 2 ||
2960 (recovery_cp < MaxSector && sh->sector >= recovery_cp)) {
2961 /* Calculate the real rcw later - for now make it
2962 * look like rcw is cheaper
2965 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2966 conf->max_degraded, (unsigned long long)recovery_cp,
2967 (unsigned long long)sh->sector);
2968 } else for (i = disks; i--; ) {
2969 /* would I have to read this buffer for read_modify_write */
2970 struct r5dev *dev = &sh->dev[i];
2971 if ((dev->towrite || i == sh->pd_idx) &&
2972 !test_bit(R5_LOCKED, &dev->flags) &&
2973 !(test_bit(R5_UPTODATE, &dev->flags) ||
2974 test_bit(R5_Wantcompute, &dev->flags))) {
2975 if (test_bit(R5_Insync, &dev->flags))
2978 rmw += 2*disks; /* cannot read it */
2980 /* Would I have to read this buffer for reconstruct_write */
2981 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2982 !test_bit(R5_LOCKED, &dev->flags) &&
2983 !(test_bit(R5_UPTODATE, &dev->flags) ||
2984 test_bit(R5_Wantcompute, &dev->flags))) {
2985 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2990 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2991 (unsigned long long)sh->sector, rmw, rcw);
2992 set_bit(STRIPE_HANDLE, &sh->state);
2993 if (rmw < rcw && rmw > 0) {
2994 /* prefer read-modify-write, but need to get some data */
2995 if (conf->mddev->queue)
2996 blk_add_trace_msg(conf->mddev->queue,
2997 "raid5 rmw %llu %d",
2998 (unsigned long long)sh->sector, rmw);
2999 for (i = disks; i--; ) {
3000 struct r5dev *dev = &sh->dev[i];
3001 if ((dev->towrite || i == sh->pd_idx) &&
3002 !test_bit(R5_LOCKED, &dev->flags) &&
3003 !(test_bit(R5_UPTODATE, &dev->flags) ||
3004 test_bit(R5_Wantcompute, &dev->flags)) &&
3005 test_bit(R5_Insync, &dev->flags)) {
3007 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
3008 pr_debug("Read_old block "
3009 "%d for r-m-w\n", i);
3010 set_bit(R5_LOCKED, &dev->flags);
3011 set_bit(R5_Wantread, &dev->flags);
3014 set_bit(STRIPE_DELAYED, &sh->state);
3015 set_bit(STRIPE_HANDLE, &sh->state);
3020 if (rcw <= rmw && rcw > 0) {
3021 /* want reconstruct write, but need to get some data */
3024 for (i = disks; i--; ) {
3025 struct r5dev *dev = &sh->dev[i];
3026 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
3027 i != sh->pd_idx && i != sh->qd_idx &&
3028 !test_bit(R5_LOCKED, &dev->flags) &&
3029 !(test_bit(R5_UPTODATE, &dev->flags) ||
3030 test_bit(R5_Wantcompute, &dev->flags))) {
3032 if (!test_bit(R5_Insync, &dev->flags))
3033 continue; /* it's a failed drive */
3035 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
3036 pr_debug("Read_old block "
3037 "%d for Reconstruct\n", i);
3038 set_bit(R5_LOCKED, &dev->flags);
3039 set_bit(R5_Wantread, &dev->flags);
3043 set_bit(STRIPE_DELAYED, &sh->state);
3044 set_bit(STRIPE_HANDLE, &sh->state);
3048 if (rcw && conf->mddev->queue)
3049 blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
3050 (unsigned long long)sh->sector,
3051 rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
3053 /* now if nothing is locked, and if we have enough data,
3054 * we can start a write request
3056 /* since handle_stripe can be called at any time we need to handle the
3057 * case where a compute block operation has been submitted and then a
3058 * subsequent call wants to start a write request. raid_run_ops only
3059 * handles the case where compute block and reconstruct are requested
3060 * simultaneously. If this is not the case then new writes need to be
3061 * held off until the compute completes.
3063 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
3064 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
3065 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
3066 schedule_reconstruction(sh, s, rcw == 0, 0);
3069 static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
3070 struct stripe_head_state *s, int disks)
3072 struct r5dev *dev = NULL;
3074 set_bit(STRIPE_HANDLE, &sh->state);
3076 switch (sh->check_state) {
3077 case check_state_idle:
3078 /* start a new check operation if there are no failures */
3079 if (s->failed == 0) {
3080 BUG_ON(s->uptodate != disks);
3081 sh->check_state = check_state_run;
3082 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3083 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
3087 dev = &sh->dev[s->failed_num[0]];
3089 case check_state_compute_result:
3090 sh->check_state = check_state_idle;
3092 dev = &sh->dev[sh->pd_idx];
3094 /* check that a write has not made the stripe insync */
3095 if (test_bit(STRIPE_INSYNC, &sh->state))
3098 /* either failed parity check, or recovery is happening */
3099 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3100 BUG_ON(s->uptodate != disks);
3102 set_bit(R5_LOCKED, &dev->flags);
3104 set_bit(R5_Wantwrite, &dev->flags);
3106 clear_bit(STRIPE_DEGRADED, &sh->state);
3107 set_bit(STRIPE_INSYNC, &sh->state);
3109 case check_state_run:
3110 break; /* we will be called again upon completion */
3111 case check_state_check_result:
3112 sh->check_state = check_state_idle;
3114 /* if a failure occurred during the check operation, leave
3115 * STRIPE_INSYNC not set and let the stripe be handled again
3120 /* handle a successful check operation, if parity is correct
3121 * we are done. Otherwise update the mismatch count and repair
3122 * parity if !MD_RECOVERY_CHECK
3124 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
3125 /* parity is correct (on disc,
3126 * not in buffer any more)
3128 set_bit(STRIPE_INSYNC, &sh->state);
3130 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3131 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3132 /* don't try to repair!! */
3133 set_bit(STRIPE_INSYNC, &sh->state);
3135 sh->check_state = check_state_compute_run;
3136 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3137 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3138 set_bit(R5_Wantcompute,
3139 &sh->dev[sh->pd_idx].flags);
3140 sh->ops.target = sh->pd_idx;
3141 sh->ops.target2 = -1;
3146 case check_state_compute_run:
3149 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3150 __func__, sh->check_state,
3151 (unsigned long long) sh->sector);
3157 static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
3158 struct stripe_head_state *s,
3161 int pd_idx = sh->pd_idx;
3162 int qd_idx = sh->qd_idx;
3165 set_bit(STRIPE_HANDLE, &sh->state);
3167 BUG_ON(s->failed > 2);
3169 /* Want to check and possibly repair P and Q.
3170 * However there could be one 'failed' device, in which
3171 * case we can only check one of them, possibly using the
3172 * other to generate missing data
3175 switch (sh->check_state) {
3176 case check_state_idle:
3177 /* start a new check operation if there are < 2 failures */
3178 if (s->failed == s->q_failed) {
3179 /* The only possible failed device holds Q, so it
3180 * makes sense to check P (If anything else were failed,
3181 * we would have used P to recreate it).
3183 sh->check_state = check_state_run;
3185 if (!s->q_failed && s->failed < 2) {
3186 /* Q is not failed, and we didn't use it to generate
3187 * anything, so it makes sense to check it
3189 if (sh->check_state == check_state_run)
3190 sh->check_state = check_state_run_pq;
3192 sh->check_state = check_state_run_q;
3195 /* discard potentially stale zero_sum_result */
3196 sh->ops.zero_sum_result = 0;
3198 if (sh->check_state == check_state_run) {
3199 /* async_xor_zero_sum destroys the contents of P */
3200 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
3203 if (sh->check_state >= check_state_run &&
3204 sh->check_state <= check_state_run_pq) {
3205 /* async_syndrome_zero_sum preserves P and Q, so
3206 * no need to mark them !uptodate here
3208 set_bit(STRIPE_OP_CHECK, &s->ops_request);
3212 /* we have 2-disk failure */
3213 BUG_ON(s->failed != 2);
3215 case check_state_compute_result:
3216 sh->check_state = check_state_idle;
3218 /* check that a write has not made the stripe insync */
3219 if (test_bit(STRIPE_INSYNC, &sh->state))
3222 /* now write out any block on a failed drive,
3223 * or P or Q if they were recomputed
3225 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
3226 if (s->failed == 2) {
3227 dev = &sh->dev[s->failed_num[1]];
3229 set_bit(R5_LOCKED, &dev->flags);
3230 set_bit(R5_Wantwrite, &dev->flags);
3232 if (s->failed >= 1) {
3233 dev = &sh->dev[s->failed_num[0]];
3235 set_bit(R5_LOCKED, &dev->flags);
3236 set_bit(R5_Wantwrite, &dev->flags);
3238 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3239 dev = &sh->dev[pd_idx];
3241 set_bit(R5_LOCKED, &dev->flags);
3242 set_bit(R5_Wantwrite, &dev->flags);
3244 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3245 dev = &sh->dev[qd_idx];
3247 set_bit(R5_LOCKED, &dev->flags);
3248 set_bit(R5_Wantwrite, &dev->flags);
3250 clear_bit(STRIPE_DEGRADED, &sh->state);
3252 set_bit(STRIPE_INSYNC, &sh->state);
3254 case check_state_run:
3255 case check_state_run_q:
3256 case check_state_run_pq:
3257 break; /* we will be called again upon completion */
3258 case check_state_check_result:
3259 sh->check_state = check_state_idle;
3261 /* handle a successful check operation, if parity is correct
3262 * we are done. Otherwise update the mismatch count and repair
3263 * parity if !MD_RECOVERY_CHECK
3265 if (sh->ops.zero_sum_result == 0) {
3266 /* both parities are correct */
3268 set_bit(STRIPE_INSYNC, &sh->state);
3270 /* in contrast to the raid5 case we can validate
3271 * parity, but still have a failure to write
3274 sh->check_state = check_state_compute_result;
3275 /* Returning at this point means that we may go
3276 * off and bring p and/or q uptodate again so
3277 * we make sure to check zero_sum_result again
3278 * to verify if p or q need writeback
3282 atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
3283 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
3284 /* don't try to repair!! */
3285 set_bit(STRIPE_INSYNC, &sh->state);
3287 int *target = &sh->ops.target;
3289 sh->ops.target = -1;
3290 sh->ops.target2 = -1;
3291 sh->check_state = check_state_compute_run;
3292 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
3293 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
3294 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
3295 set_bit(R5_Wantcompute,
3296 &sh->dev[pd_idx].flags);
3298 target = &sh->ops.target2;
3301 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
3302 set_bit(R5_Wantcompute,
3303 &sh->dev[qd_idx].flags);
3310 case check_state_compute_run:
3313 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
3314 __func__, sh->check_state,
3315 (unsigned long long) sh->sector);
3320 static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
3324 /* We have read all the blocks in this stripe and now we need to
3325 * copy some of them into a target stripe for expand.
3327 struct dma_async_tx_descriptor *tx = NULL;
3328 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3329 for (i = 0; i < sh->disks; i++)
3330 if (i != sh->pd_idx && i != sh->qd_idx) {
3332 struct stripe_head *sh2;
3333 struct async_submit_ctl submit;
3335 sector_t bn = compute_blocknr(sh, i, 1);
3336 sector_t s = raid5_compute_sector(conf, bn, 0,
3338 sh2 = get_active_stripe(conf, s, 0, 1, 1);
3340 /* so far only the early blocks of this stripe
3341 * have been requested. When later blocks
3342 * get requested, we will try again
3345 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
3346 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
3347 /* must have already done this block */
3348 release_stripe(sh2);
3352 /* place all the copies on one channel */
3353 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
3354 tx = async_memcpy(sh2->dev[dd_idx].page,
3355 sh->dev[i].page, 0, 0, STRIPE_SIZE,
3358 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
3359 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
3360 for (j = 0; j < conf->raid_disks; j++)
3361 if (j != sh2->pd_idx &&
3363 !test_bit(R5_Expanded, &sh2->dev[j].flags))
3365 if (j == conf->raid_disks) {
3366 set_bit(STRIPE_EXPAND_READY, &sh2->state);
3367 set_bit(STRIPE_HANDLE, &sh2->state);
3369 release_stripe(sh2);
3372 /* done submitting copies, wait for them to complete */
3373 async_tx_quiesce(&tx);
3377 * handle_stripe - do things to a stripe.
3379 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3380 * state of various bits to see what needs to be done.
3382 * return some read requests which now have data
3383 * return some write requests which are safely on storage
3384 * schedule a read on some buffers
3385 * schedule a write of some buffers
3386 * return confirmation of parity correctness
3390 static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
3392 struct r5conf *conf = sh->raid_conf;
3393 int disks = sh->disks;
3396 int do_recovery = 0;
3398 memset(s, 0, sizeof(*s));
3400 s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3401 s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3402 s->failed_num[0] = -1;
3403 s->failed_num[1] = -1;
3405 /* Now to look around and see what can be done */
3407 for (i=disks; i--; ) {
3408 struct md_rdev *rdev;
3415 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3417 dev->toread, dev->towrite, dev->written);
3418 /* maybe we can reply to a read
3420 * new wantfill requests are only permitted while
3421 * ops_complete_biofill is guaranteed to be inactive
3423 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3424 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3425 set_bit(R5_Wantfill, &dev->flags);
3427 /* now count some things */
3428 if (test_bit(R5_LOCKED, &dev->flags))
3430 if (test_bit(R5_UPTODATE, &dev->flags))
3432 if (test_bit(R5_Wantcompute, &dev->flags)) {
3434 BUG_ON(s->compute > 2);
3437 if (test_bit(R5_Wantfill, &dev->flags))
3439 else if (dev->toread)
3443 if (!test_bit(R5_OVERWRITE, &dev->flags))
3448 /* Prefer to use the replacement for reads, but only
3449 * if it is recovered enough and has no bad blocks.
3451 rdev = rcu_dereference(conf->disks[i].replacement);
3452 if (rdev && !test_bit(Faulty, &rdev->flags) &&
3453 rdev->recovery_offset >= sh->sector + STRIPE_SECTORS &&
3454 !is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3455 &first_bad, &bad_sectors))
3456 set_bit(R5_ReadRepl, &dev->flags);
3459 set_bit(R5_NeedReplace, &dev->flags);
3460 rdev = rcu_dereference(conf->disks[i].rdev);
3461 clear_bit(R5_ReadRepl, &dev->flags);
3463 if (rdev && test_bit(Faulty, &rdev->flags))
3466 is_bad = is_badblock(rdev, sh->sector, STRIPE_SECTORS,
3467 &first_bad, &bad_sectors);
3468 if (s->blocked_rdev == NULL
3469 && (test_bit(Blocked, &rdev->flags)
3472 set_bit(BlockedBadBlocks,
3474 s->blocked_rdev = rdev;
3475 atomic_inc(&rdev->nr_pending);
3478 clear_bit(R5_Insync, &dev->flags);
3482 /* also not in-sync */
3483 if (!test_bit(WriteErrorSeen, &rdev->flags) &&
3484 test_bit(R5_UPTODATE, &dev->flags)) {
3485 /* treat as in-sync, but with a read error
3486 * which we can now try to correct
3488 set_bit(R5_Insync, &dev->flags);
3489 set_bit(R5_ReadError, &dev->flags);
3491 } else if (test_bit(In_sync, &rdev->flags))
3492 set_bit(R5_Insync, &dev->flags);
3493 else if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3494 /* in sync if before recovery_offset */
3495 set_bit(R5_Insync, &dev->flags);
3496 else if (test_bit(R5_UPTODATE, &dev->flags) &&
3497 test_bit(R5_Expanded, &dev->flags))
3498 /* If we've reshaped into here, we assume it is Insync.
3499 * We will shortly update recovery_offset to make
3502 set_bit(R5_Insync, &dev->flags);
3504 if (rdev && test_bit(R5_WriteError, &dev->flags)) {
3505 /* This flag does not apply to '.replacement'
3506 * only to .rdev, so make sure to check that*/
3507 struct md_rdev *rdev2 = rcu_dereference(
3508 conf->disks[i].rdev);
3510 clear_bit(R5_Insync, &dev->flags);
3511 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3512 s->handle_bad_blocks = 1;
3513 atomic_inc(&rdev2->nr_pending);
3515 clear_bit(R5_WriteError, &dev->flags);
3517 if (rdev && test_bit(R5_MadeGood, &dev->flags)) {
3518 /* This flag does not apply to '.replacement'
3519 * only to .rdev, so make sure to check that*/
3520 struct md_rdev *rdev2 = rcu_dereference(
3521 conf->disks[i].rdev);
3522 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3523 s->handle_bad_blocks = 1;
3524 atomic_inc(&rdev2->nr_pending);
3526 clear_bit(R5_MadeGood, &dev->flags);
3528 if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
3529 struct md_rdev *rdev2 = rcu_dereference(
3530 conf->disks[i].replacement);
3531 if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
3532 s->handle_bad_blocks = 1;
3533 atomic_inc(&rdev2->nr_pending);
3535 clear_bit(R5_MadeGoodRepl, &dev->flags);
3537 if (!test_bit(R5_Insync, &dev->flags)) {
3538 /* The ReadError flag will just be confusing now */
3539 clear_bit(R5_ReadError, &dev->flags);
3540 clear_bit(R5_ReWrite, &dev->flags);
3542 if (test_bit(R5_ReadError, &dev->flags))
3543 clear_bit(R5_Insync, &dev->flags);
3544 if (!test_bit(R5_Insync, &dev->flags)) {
3546 s->failed_num[s->failed] = i;
3548 if (rdev && !test_bit(Faulty, &rdev->flags))
3552 if (test_bit(STRIPE_SYNCING, &sh->state)) {
3553 /* If there is a failed device being replaced,
3554 * we must be recovering.
3555 * else if we are after recovery_cp, we must be syncing
3556 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3557 * else we can only be replacing
3558 * sync and recovery both need to read all devices, and so
3559 * use the same flag.
3562 sh->sector >= conf->mddev->recovery_cp ||
3563 test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
3571 static void handle_stripe(struct stripe_head *sh)
3573 struct stripe_head_state s;
3574 struct r5conf *conf = sh->raid_conf;
3577 int disks = sh->disks;
3578 struct r5dev *pdev, *qdev;
3580 clear_bit(STRIPE_HANDLE, &sh->state);
3581 if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
3582 /* already being handled, ensure it gets handled
3583 * again when current action finishes */
3584 set_bit(STRIPE_HANDLE, &sh->state);
3588 if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3589 spin_lock(&sh->stripe_lock);
3590 /* Cannot process 'sync' concurrently with 'discard' */
3591 if (!test_bit(STRIPE_DISCARD, &sh->state) &&
3592 test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3593 set_bit(STRIPE_SYNCING, &sh->state);
3594 clear_bit(STRIPE_INSYNC, &sh->state);
3595 clear_bit(STRIPE_REPLACED, &sh->state);
3597 spin_unlock(&sh->stripe_lock);
3599 clear_bit(STRIPE_DELAYED, &sh->state);
3601 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3602 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3603 (unsigned long long)sh->sector, sh->state,
3604 atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
3605 sh->check_state, sh->reconstruct_state);
3607 analyse_stripe(sh, &s);
3609 if (s.handle_bad_blocks) {
3610 set_bit(STRIPE_HANDLE, &sh->state);
3614 if (unlikely(s.blocked_rdev)) {
3615 if (s.syncing || s.expanding || s.expanded ||
3616 s.replacing || s.to_write || s.written) {
3617 set_bit(STRIPE_HANDLE, &sh->state);
3620 /* There is nothing for the blocked_rdev to block */
3621 rdev_dec_pending(s.blocked_rdev, conf->mddev);
3622 s.blocked_rdev = NULL;
3625 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3626 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3627 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3630 pr_debug("locked=%d uptodate=%d to_read=%d"
3631 " to_write=%d failed=%d failed_num=%d,%d\n",
3632 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3633 s.failed_num[0], s.failed_num[1]);
3634 /* check if the array has lost more than max_degraded devices and,
3635 * if so, some requests might need to be failed.
3637 if (s.failed > conf->max_degraded) {
3638 sh->check_state = 0;
3639 sh->reconstruct_state = 0;
3640 if (s.to_read+s.to_write+s.written)
3641 handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
3642 if (s.syncing + s.replacing)
3643 handle_failed_sync(conf, sh, &s);
3646 /* Now we check to see if any write operations have recently
3650 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3652 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3653 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3654 sh->reconstruct_state = reconstruct_state_idle;
3656 /* All the 'written' buffers and the parity block are ready to
3657 * be written back to disk
3659 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
3660 !test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
3661 BUG_ON(sh->qd_idx >= 0 &&
3662 !test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
3663 !test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
3664 for (i = disks; i--; ) {
3665 struct r5dev *dev = &sh->dev[i];
3666 if (test_bit(R5_LOCKED, &dev->flags) &&
3667 (i == sh->pd_idx || i == sh->qd_idx ||
3669 pr_debug("Writing block %d\n", i);
3670 set_bit(R5_Wantwrite, &dev->flags);
3673 if (!test_bit(R5_Insync, &dev->flags) ||
3674 ((i == sh->pd_idx || i == sh->qd_idx) &&
3676 set_bit(STRIPE_INSYNC, &sh->state);
3679 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3680 s.dec_preread_active = 1;
3684 * might be able to return some write requests if the parity blocks
3685 * are safe, or on a failed drive
3687 pdev = &sh->dev[sh->pd_idx];
3688 s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
3689 || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
3690 qdev = &sh->dev[sh->qd_idx];
3691 s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
3692 || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
3696 (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3697 && !test_bit(R5_LOCKED, &pdev->flags)
3698 && (test_bit(R5_UPTODATE, &pdev->flags) ||
3699 test_bit(R5_Discard, &pdev->flags))))) &&
3700 (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3701 && !test_bit(R5_LOCKED, &qdev->flags)
3702 && (test_bit(R5_UPTODATE, &qdev->flags) ||
3703 test_bit(R5_Discard, &qdev->flags))))))
3704 handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
3706 /* Now we might consider reading some blocks, either to check/generate
3707 * parity, or to satisfy requests
3708 * or to load a block that is being partially written.
3710 if (s.to_read || s.non_overwrite
3711 || (conf->level == 6 && s.to_write && s.failed)
3712 || (s.syncing && (s.uptodate + s.compute < disks))
3715 handle_stripe_fill(sh, &s, disks);
3717 /* Now to consider new write requests and what else, if anything
3718 * should be read. We do not handle new writes when:
3719 * 1/ A 'write' operation (copy+xor) is already in flight.
3720 * 2/ A 'check' operation is in flight, as it may clobber the parity
3723 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3724 handle_stripe_dirtying(conf, sh, &s, disks);
3726 /* maybe we need to check and possibly fix the parity for this stripe
3727 * Any reads will already have been scheduled, so we just see if enough
3728 * data is available. The parity check is held off while parity
3729 * dependent operations are in flight.
3731 if (sh->check_state ||
3732 (s.syncing && s.locked == 0 &&
3733 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3734 !test_bit(STRIPE_INSYNC, &sh->state))) {
3735 if (conf->level == 6)
3736 handle_parity_checks6(conf, sh, &s, disks);
3738 handle_parity_checks5(conf, sh, &s, disks);
3741 if ((s.replacing || s.syncing) && s.locked == 0
3742 && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
3743 && !test_bit(STRIPE_REPLACED, &sh->state)) {
3744 /* Write out to replacement devices where possible */
3745 for (i = 0; i < conf->raid_disks; i++)
3746 if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
3747 WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
3748 set_bit(R5_WantReplace, &sh->dev[i].flags);
3749 set_bit(R5_LOCKED, &sh->dev[i].flags);
3753 set_bit(STRIPE_INSYNC, &sh->state);
3754 set_bit(STRIPE_REPLACED, &sh->state);
3756 if ((s.syncing || s.replacing) && s.locked == 0 &&
3757 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3758 test_bit(STRIPE_INSYNC, &sh->state)) {
3759 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3760 clear_bit(STRIPE_SYNCING, &sh->state);
3761 if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
3762 wake_up(&conf->wait_for_overlap);
3765 /* If the failed drives are just a ReadError, then we might need
3766 * to progress the repair/check process
3768 if (s.failed <= conf->max_degraded && !conf->mddev->ro)
3769 for (i = 0; i < s.failed; i++) {
3770 struct r5dev *dev = &sh->dev[s.failed_num[i]];
3771 if (test_bit(R5_ReadError, &dev->flags)
3772 && !test_bit(R5_LOCKED, &dev->flags)
3773 && test_bit(R5_UPTODATE, &dev->flags)
3775 if (!test_bit(R5_ReWrite, &dev->flags)) {
3776 set_bit(R5_Wantwrite, &dev->flags);
3777 set_bit(R5_ReWrite, &dev->flags);
3778 set_bit(R5_LOCKED, &dev->flags);
3781 /* let's read it back */
3782 set_bit(R5_Wantread, &dev->flags);
3783 set_bit(R5_LOCKED, &dev->flags);
3790 /* Finish reconstruct operations initiated by the expansion process */
3791 if (sh->reconstruct_state == reconstruct_state_result) {
3792 struct stripe_head *sh_src
3793 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3794 if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
3795 /* sh cannot be written until sh_src has been read.
3796 * so arrange for sh to be delayed a little
3798 set_bit(STRIPE_DELAYED, &sh->state);
3799 set_bit(STRIPE_HANDLE, &sh->state);
3800 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3802 atomic_inc(&conf->preread_active_stripes);
3803 release_stripe(sh_src);
3807 release_stripe(sh_src);
3809 sh->reconstruct_state = reconstruct_state_idle;
3810 clear_bit(STRIPE_EXPANDING, &sh->state);
3811 for (i = conf->raid_disks; i--; ) {
3812 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3813 set_bit(R5_LOCKED, &sh->dev[i].flags);
3818 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3819 !sh->reconstruct_state) {
3820 /* Need to write out all blocks after computing parity */
3821 sh->disks = conf->raid_disks;
3822 stripe_set_idx(sh->sector, conf, 0, sh);
3823 schedule_reconstruction(sh, &s, 1, 1);
3824 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3825 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3826 atomic_dec(&conf->reshape_stripes);
3827 wake_up(&conf->wait_for_overlap);
3828 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3831 if (s.expanding && s.locked == 0 &&
3832 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3833 handle_stripe_expansion(conf, sh);
3836 /* wait for this device to become unblocked */
3837 if (unlikely(s.blocked_rdev)) {
3838 if (conf->mddev->external)
3839 md_wait_for_blocked_rdev(s.blocked_rdev,
3842 /* Internal metadata will immediately
3843 * be written by raid5d, so we don't
3844 * need to wait here.
3846 rdev_dec_pending(s.blocked_rdev,
3850 if (s.handle_bad_blocks)
3851 for (i = disks; i--; ) {
3852 struct md_rdev *rdev;
3853 struct r5dev *dev = &sh->dev[i];
3854 if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
3855 /* We own a safe reference to the rdev */
3856 rdev = conf->disks[i].rdev;
3857 if (!rdev_set_badblocks(rdev, sh->sector,
3859 md_error(conf->mddev, rdev);
3860 rdev_dec_pending(rdev, conf->mddev);
3862 if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
3863 rdev = conf->disks[i].rdev;
3864 rdev_clear_badblocks(rdev, sh->sector,
3866 rdev_dec_pending(rdev, conf->mddev);
3868 if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
3869 rdev = conf->disks[i].replacement;
3871 /* rdev have been moved down */
3872 rdev = conf->disks[i].rdev;
3873 rdev_clear_badblocks(rdev, sh->sector,
3875 rdev_dec_pending(rdev, conf->mddev);
3880 raid_run_ops(sh, s.ops_request);
3884 if (s.dec_preread_active) {
3885 /* We delay this until after ops_run_io so that if make_request
3886 * is waiting on a flush, it won't continue until the writes
3887 * have actually been submitted.
3889 atomic_dec(&conf->preread_active_stripes);
3890 if (atomic_read(&conf->preread_active_stripes) <
3892 md_wakeup_thread(conf->mddev->thread);
3895 return_io(s.return_bi);
3897 clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
3900 static void raid5_activate_delayed(struct r5conf *conf)
3902 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3903 while (!list_empty(&conf->delayed_list)) {
3904 struct list_head *l = conf->delayed_list.next;
3905 struct stripe_head *sh;
3906 sh = list_entry(l, struct stripe_head, lru);
3908 clear_bit(STRIPE_DELAYED, &sh->state);
3909 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3910 atomic_inc(&conf->preread_active_stripes);
3911 list_add_tail(&sh->lru, &conf->hold_list);
3912 raid5_wakeup_stripe_thread(sh);
3917 static void activate_bit_delay(struct r5conf *conf)
3919 /* device_lock is held */
3920 struct list_head head;
3921 list_add(&head, &conf->bitmap_list);
3922 list_del_init(&conf->bitmap_list);
3923 while (!list_empty(&head)) {
3924 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3925 list_del_init(&sh->lru);
3926 atomic_inc(&sh->count);
3927 __release_stripe(conf, sh);
3931 int md_raid5_congested(struct mddev *mddev, int bits)
3933 struct r5conf *conf = mddev->private;
3935 /* No difference between reads and writes. Just check
3936 * how busy the stripe_cache is
3939 if (conf->inactive_blocked)
3943 if (list_empty_careful(&conf->inactive_list))
3948 EXPORT_SYMBOL_GPL(md_raid5_congested);
3950 static int raid5_congested(void *data, int bits)
3952 struct mddev *mddev = data;
3954 return mddev_congested(mddev, bits) ||
3955 md_raid5_congested(mddev, bits);
3958 /* We want read requests to align with chunks where possible,
3959 * but write requests don't need to.
3961 static int raid5_mergeable_bvec(struct request_queue *q,
3962 struct bvec_merge_data *bvm,
3963 struct bio_vec *biovec)
3965 struct mddev *mddev = q->queuedata;
3966 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
3968 unsigned int chunk_sectors = mddev->chunk_sectors;
3969 unsigned int bio_sectors = bvm->bi_size >> 9;
3971 if ((bvm->bi_rw & 1) == WRITE)
3972 return biovec->bv_len; /* always allow writes to be mergeable */
3974 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3975 chunk_sectors = mddev->new_chunk_sectors;
3976 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3977 if (max < 0) max = 0;
3978 if (max <= biovec->bv_len && bio_sectors == 0)
3979 return biovec->bv_len;
3985 static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
3987 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3988 unsigned int chunk_sectors = mddev->chunk_sectors;
3989 unsigned int bio_sectors = bio_sectors(bio);
3991 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3992 chunk_sectors = mddev->new_chunk_sectors;
3993 return chunk_sectors >=
3994 ((sector & (chunk_sectors - 1)) + bio_sectors);
3998 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3999 * later sampled by raid5d.
4001 static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
4003 unsigned long flags;
4005 spin_lock_irqsave(&conf->device_lock, flags);
4007 bi->bi_next = conf->retry_read_aligned_list;
4008 conf->retry_read_aligned_list = bi;
4010 spin_unlock_irqrestore(&conf->device_lock, flags);
4011 md_wakeup_thread(conf->mddev->thread);
4015 static struct bio *remove_bio_from_retry(struct r5conf *conf)
4019 bi = conf->retry_read_aligned;
4021 conf->retry_read_aligned = NULL;
4024 bi = conf->retry_read_aligned_list;
4026 conf->retry_read_aligned_list = bi->bi_next;
4029 * this sets the active strip count to 1 and the processed
4030 * strip count to zero (upper 8 bits)
4032 raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */
4040 * The "raid5_align_endio" should check if the read succeeded and if it
4041 * did, call bio_endio on the original bio (having bio_put the new bio
4043 * If the read failed..
4045 static void raid5_align_endio(struct bio *bi, int error)
4047 struct bio* raid_bi = bi->bi_private;
4048 struct mddev *mddev;
4049 struct r5conf *conf;
4050 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
4051 struct md_rdev *rdev;
4055 rdev = (void*)raid_bi->bi_next;
4056 raid_bi->bi_next = NULL;
4057 mddev = rdev->mddev;
4058 conf = mddev->private;
4060 rdev_dec_pending(rdev, conf->mddev);
4062 if (!error && uptodate) {
4063 trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
4065 bio_endio(raid_bi, 0);
4066 if (atomic_dec_and_test(&conf->active_aligned_reads))
4067 wake_up(&conf->wait_for_stripe);
4072 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
4074 add_bio_to_retry(raid_bi, conf);
4077 static int bio_fits_rdev(struct bio *bi)
4079 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
4081 if (bio_sectors(bi) > queue_max_sectors(q))
4083 blk_recount_segments(q, bi);
4084 if (bi->bi_phys_segments > queue_max_segments(q))
4087 if (q->merge_bvec_fn)
4088 /* it's too hard to apply the merge_bvec_fn at this stage,
4097 static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio)
4099 struct r5conf *conf = mddev->private;
4101 struct bio* align_bi;
4102 struct md_rdev *rdev;
4103 sector_t end_sector;
4105 if (!in_chunk_boundary(mddev, raid_bio)) {
4106 pr_debug("chunk_aligned_read : non aligned\n");
4110 * use bio_clone_mddev to make a copy of the bio
4112 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
4116 * set bi_end_io to a new function, and set bi_private to the
4119 align_bi->bi_end_io = raid5_align_endio;
4120 align_bi->bi_private = raid_bio;
4124 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
4128 end_sector = bio_end_sector(align_bi);
4130 rdev = rcu_dereference(conf->disks[dd_idx].replacement);
4131 if (!rdev || test_bit(Faulty, &rdev->flags) ||
4132 rdev->recovery_offset < end_sector) {
4133 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
4135 (test_bit(Faulty, &rdev->flags) ||
4136 !(test_bit(In_sync, &rdev->flags) ||
4137 rdev->recovery_offset >= end_sector)))
4144 atomic_inc(&rdev->nr_pending);
4146 raid_bio->bi_next = (void*)rdev;
4147 align_bi->bi_bdev = rdev->bdev;
4148 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
4150 if (!bio_fits_rdev(align_bi) ||
4151 is_badblock(rdev, align_bi->bi_sector, bio_sectors(align_bi),
4152 &first_bad, &bad_sectors)) {
4153 /* too big in some way, or has a known bad block */
4155 rdev_dec_pending(rdev, mddev);
4159 /* No reshape active, so we can trust rdev->data_offset */
4160 align_bi->bi_sector += rdev->data_offset;
4162 spin_lock_irq(&conf->device_lock);
4163 wait_event_lock_irq(conf->wait_for_stripe,
4166 atomic_inc(&conf->active_aligned_reads);
4167 spin_unlock_irq(&conf->device_lock);
4170 trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
4171 align_bi, disk_devt(mddev->gendisk),
4172 raid_bio->bi_sector);
4173 generic_make_request(align_bi);
4182 /* __get_priority_stripe - get the next stripe to process
4184 * Full stripe writes are allowed to pass preread active stripes up until
4185 * the bypass_threshold is exceeded. In general the bypass_count
4186 * increments when the handle_list is handled before the hold_list; however, it
4187 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4188 * stripe with in flight i/o. The bypass_count will be reset when the
4189 * head of the hold_list has changed, i.e. the head was promoted to the
4192 static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
4194 struct stripe_head *sh = NULL, *tmp;
4195 struct list_head *handle_list = NULL;
4196 struct r5worker_group *wg = NULL;
4198 if (conf->worker_cnt_per_group == 0) {
4199 handle_list = &conf->handle_list;
4200 } else if (group != ANY_GROUP) {
4201 handle_list = &conf->worker_groups[group].handle_list;
4202 wg = &conf->worker_groups[group];
4205 for (i = 0; i < conf->group_cnt; i++) {
4206 handle_list = &conf->worker_groups[i].handle_list;
4207 wg = &conf->worker_groups[i];
4208 if (!list_empty(handle_list))
4213 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4215 list_empty(handle_list) ? "empty" : "busy",
4216 list_empty(&conf->hold_list) ? "empty" : "busy",
4217 atomic_read(&conf->pending_full_writes), conf->bypass_count);
4219 if (!list_empty(handle_list)) {
4220 sh = list_entry(handle_list->next, typeof(*sh), lru);
4222 if (list_empty(&conf->hold_list))
4223 conf->bypass_count = 0;
4224 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
4225 if (conf->hold_list.next == conf->last_hold)
4226 conf->bypass_count++;
4228 conf->last_hold = conf->hold_list.next;
4229 conf->bypass_count -= conf->bypass_threshold;
4230 if (conf->bypass_count < 0)
4231 conf->bypass_count = 0;
4234 } else if (!list_empty(&conf->hold_list) &&
4235 ((conf->bypass_threshold &&
4236 conf->bypass_count > conf->bypass_threshold) ||
4237 atomic_read(&conf->pending_full_writes) == 0)) {
4239 list_for_each_entry(tmp, &conf->hold_list, lru) {
4240 if (conf->worker_cnt_per_group == 0 ||
4241 group == ANY_GROUP ||
4242 !cpu_online(tmp->cpu) ||
4243 cpu_to_group(tmp->cpu) == group) {
4250 conf->bypass_count -= conf->bypass_threshold;
4251 if (conf->bypass_count < 0)
4252 conf->bypass_count = 0;
4264 list_del_init(&sh->lru);
4265 atomic_inc(&sh->count);
4266 BUG_ON(atomic_read(&sh->count) != 1);
4270 struct raid5_plug_cb {
4271 struct blk_plug_cb cb;
4272 struct list_head list;
4275 static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
4277 struct raid5_plug_cb *cb = container_of(
4278 blk_cb, struct raid5_plug_cb, cb);
4279 struct stripe_head *sh;
4280 struct mddev *mddev = cb->cb.data;
4281 struct r5conf *conf = mddev->private;
4284 if (cb->list.next && !list_empty(&cb->list)) {
4285 spin_lock_irq(&conf->device_lock);
4286 while (!list_empty(&cb->list)) {
4287 sh = list_first_entry(&cb->list, struct stripe_head, lru);
4288 list_del_init(&sh->lru);
4290 * avoid race release_stripe_plug() sees
4291 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4292 * is still in our list
4294 smp_mb__before_clear_bit();
4295 clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
4297 * STRIPE_ON_RELEASE_LIST could be set here. In that
4298 * case, the count is always > 1 here
4300 __release_stripe(conf, sh);
4303 spin_unlock_irq(&conf->device_lock);
4306 trace_block_unplug(mddev->queue, cnt, !from_schedule);
4310 static void release_stripe_plug(struct mddev *mddev,
4311 struct stripe_head *sh)
4313 struct blk_plug_cb *blk_cb = blk_check_plugged(
4314 raid5_unplug, mddev,
4315 sizeof(struct raid5_plug_cb));
4316 struct raid5_plug_cb *cb;
4323 cb = container_of(blk_cb, struct raid5_plug_cb, cb);
4325 if (cb->list.next == NULL)
4326 INIT_LIST_HEAD(&cb->list);
4328 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
4329 list_add_tail(&sh->lru, &cb->list);
4334 static void make_discard_request(struct mddev *mddev, struct bio *bi)
4336 struct r5conf *conf = mddev->private;
4337 sector_t logical_sector, last_sector;
4338 struct stripe_head *sh;
4342 if (mddev->reshape_position != MaxSector)
4343 /* Skip discard while reshape is happening */
4346 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4347 last_sector = bi->bi_sector + (bi->bi_size>>9);
4350 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4352 stripe_sectors = conf->chunk_sectors *
4353 (conf->raid_disks - conf->max_degraded);
4354 logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
4356 sector_div(last_sector, stripe_sectors);
4358 logical_sector *= conf->chunk_sectors;
4359 last_sector *= conf->chunk_sectors;
4361 for (; logical_sector < last_sector;
4362 logical_sector += STRIPE_SECTORS) {
4366 sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
4367 prepare_to_wait(&conf->wait_for_overlap, &w,
4368 TASK_UNINTERRUPTIBLE);
4369 set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
4370 if (test_bit(STRIPE_SYNCING, &sh->state)) {
4375 clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
4376 spin_lock_irq(&sh->stripe_lock);
4377 for (d = 0; d < conf->raid_disks; d++) {
4378 if (d == sh->pd_idx || d == sh->qd_idx)
4380 if (sh->dev[d].towrite || sh->dev[d].toread) {
4381 set_bit(R5_Overlap, &sh->dev[d].flags);
4382 spin_unlock_irq(&sh->stripe_lock);
4388 set_bit(STRIPE_DISCARD, &sh->state);
4389 finish_wait(&conf->wait_for_overlap, &w);
4390 for (d = 0; d < conf->raid_disks; d++) {
4391 if (d == sh->pd_idx || d == sh->qd_idx)
4393 sh->dev[d].towrite = bi;
4394 set_bit(R5_OVERWRITE, &sh->dev[d].flags);
4395 raid5_inc_bi_active_stripes(bi);
4397 spin_unlock_irq(&sh->stripe_lock);
4398 if (conf->mddev->bitmap) {
4400 d < conf->raid_disks - conf->max_degraded;
4402 bitmap_startwrite(mddev->bitmap,
4406 sh->bm_seq = conf->seq_flush + 1;
4407 set_bit(STRIPE_BIT_DELAY, &sh->state);
4410 set_bit(STRIPE_HANDLE, &sh->state);
4411 clear_bit(STRIPE_DELAYED, &sh->state);
4412 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4413 atomic_inc(&conf->preread_active_stripes);
4414 release_stripe_plug(mddev, sh);
4417 remaining = raid5_dec_bi_active_stripes(bi);
4418 if (remaining == 0) {
4419 md_write_end(mddev);
4424 static void make_request(struct mddev *mddev, struct bio * bi)
4426 struct r5conf *conf = mddev->private;
4428 sector_t new_sector;
4429 sector_t logical_sector, last_sector;
4430 struct stripe_head *sh;
4431 const int rw = bio_data_dir(bi);
4434 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
4435 md_flush_request(mddev, bi);
4439 md_write_start(mddev, bi);
4442 mddev->reshape_position == MaxSector &&
4443 chunk_aligned_read(mddev,bi))
4446 if (unlikely(bi->bi_rw & REQ_DISCARD)) {
4447 make_discard_request(mddev, bi);
4451 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4452 last_sector = bio_end_sector(bi);
4454 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4456 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
4462 seq = read_seqcount_begin(&conf->gen_lock);
4464 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
4465 if (unlikely(conf->reshape_progress != MaxSector)) {
4466 /* spinlock is needed as reshape_progress may be
4467 * 64bit on a 32bit platform, and so it might be
4468 * possible to see a half-updated value
4469 * Of course reshape_progress could change after
4470 * the lock is dropped, so once we get a reference
4471 * to the stripe that we think it is, we will have
4474 spin_lock_irq(&conf->device_lock);
4475 if (mddev->reshape_backwards
4476 ? logical_sector < conf->reshape_progress
4477 : logical_sector >= conf->reshape_progress) {
4480 if (mddev->reshape_backwards
4481 ? logical_sector < conf->reshape_safe
4482 : logical_sector >= conf->reshape_safe) {
4483 spin_unlock_irq(&conf->device_lock);
4488 spin_unlock_irq(&conf->device_lock);
4491 new_sector = raid5_compute_sector(conf, logical_sector,
4494 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4495 (unsigned long long)new_sector,
4496 (unsigned long long)logical_sector);
4498 sh = get_active_stripe(conf, new_sector, previous,
4499 (bi->bi_rw&RWA_MASK), 0);
4501 if (unlikely(previous)) {
4502 /* expansion might have moved on while waiting for a
4503 * stripe, so we must do the range check again.
4504 * Expansion could still move past after this
4505 * test, but as we are holding a reference to
4506 * 'sh', we know that if that happens,
4507 * STRIPE_EXPANDING will get set and the expansion
4508 * won't proceed until we finish with the stripe.
4511 spin_lock_irq(&conf->device_lock);
4512 if (mddev->reshape_backwards
4513 ? logical_sector >= conf->reshape_progress
4514 : logical_sector < conf->reshape_progress)
4515 /* mismatch, need to try again */
4517 spin_unlock_irq(&conf->device_lock);
4524 if (read_seqcount_retry(&conf->gen_lock, seq)) {
4525 /* Might have got the wrong stripe_head
4533 logical_sector >= mddev->suspend_lo &&
4534 logical_sector < mddev->suspend_hi) {
4536 /* As the suspend_* range is controlled by
4537 * userspace, we want an interruptible
4540 flush_signals(current);
4541 prepare_to_wait(&conf->wait_for_overlap,
4542 &w, TASK_INTERRUPTIBLE);
4543 if (logical_sector >= mddev->suspend_lo &&
4544 logical_sector < mddev->suspend_hi)
4549 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
4550 !add_stripe_bio(sh, bi, dd_idx, rw)) {
4551 /* Stripe is busy expanding or
4552 * add failed due to overlap. Flush everything
4555 md_wakeup_thread(mddev->thread);
4560 finish_wait(&conf->wait_for_overlap, &w);
4561 set_bit(STRIPE_HANDLE, &sh->state);
4562 clear_bit(STRIPE_DELAYED, &sh->state);
4563 if ((bi->bi_rw & REQ_SYNC) &&
4564 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4565 atomic_inc(&conf->preread_active_stripes);
4566 release_stripe_plug(mddev, sh);
4568 /* cannot get stripe for read-ahead, just give-up */
4569 clear_bit(BIO_UPTODATE, &bi->bi_flags);
4570 finish_wait(&conf->wait_for_overlap, &w);
4575 remaining = raid5_dec_bi_active_stripes(bi);
4576 if (remaining == 0) {
4579 md_write_end(mddev);
4581 trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
4587 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
4589 static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
4591 /* reshaping is quite different to recovery/resync so it is
4592 * handled quite separately ... here.
4594 * On each call to sync_request, we gather one chunk worth of
4595 * destination stripes and flag them as expanding.
4596 * Then we find all the source stripes and request reads.
4597 * As the reads complete, handle_stripe will copy the data
4598 * into the destination stripe and release that stripe.
4600 struct r5conf *conf = mddev->private;
4601 struct stripe_head *sh;
4602 sector_t first_sector, last_sector;
4603 int raid_disks = conf->previous_raid_disks;
4604 int data_disks = raid_disks - conf->max_degraded;
4605 int new_data_disks = conf->raid_disks - conf->max_degraded;
4608 sector_t writepos, readpos, safepos;
4609 sector_t stripe_addr;
4610 int reshape_sectors;
4611 struct list_head stripes;
4613 if (sector_nr == 0) {
4614 /* If restarting in the middle, skip the initial sectors */
4615 if (mddev->reshape_backwards &&
4616 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4617 sector_nr = raid5_size(mddev, 0, 0)
4618 - conf->reshape_progress;
4619 } else if (!mddev->reshape_backwards &&
4620 conf->reshape_progress > 0)
4621 sector_nr = conf->reshape_progress;
4622 sector_div(sector_nr, new_data_disks);
4624 mddev->curr_resync_completed = sector_nr;
4625 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4631 /* We need to process a full chunk at a time.
4632 * If old and new chunk sizes differ, we need to process the
4635 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4636 reshape_sectors = mddev->new_chunk_sectors;
4638 reshape_sectors = mddev->chunk_sectors;
4640 /* We update the metadata at least every 10 seconds, or when
4641 * the data about to be copied would over-write the source of
4642 * the data at the front of the range. i.e. one new_stripe
4643 * along from reshape_progress new_maps to after where
4644 * reshape_safe old_maps to
4646 writepos = conf->reshape_progress;
4647 sector_div(writepos, new_data_disks);
4648 readpos = conf->reshape_progress;
4649 sector_div(readpos, data_disks);
4650 safepos = conf->reshape_safe;
4651 sector_div(safepos, data_disks);
4652 if (mddev->reshape_backwards) {
4653 writepos -= min_t(sector_t, reshape_sectors, writepos);
4654 readpos += reshape_sectors;
4655 safepos += reshape_sectors;
4657 writepos += reshape_sectors;
4658 readpos -= min_t(sector_t, reshape_sectors, readpos);
4659 safepos -= min_t(sector_t, reshape_sectors, safepos);
4662 /* Having calculated the 'writepos' possibly use it
4663 * to set 'stripe_addr' which is where we will write to.
4665 if (mddev->reshape_backwards) {
4666 BUG_ON(conf->reshape_progress == 0);
4667 stripe_addr = writepos;
4668 BUG_ON((mddev->dev_sectors &
4669 ~((sector_t)reshape_sectors - 1))
4670 - reshape_sectors - stripe_addr
4673 BUG_ON(writepos != sector_nr + reshape_sectors);
4674 stripe_addr = sector_nr;
4677 /* 'writepos' is the most advanced device address we might write.
4678 * 'readpos' is the least advanced device address we might read.
4679 * 'safepos' is the least address recorded in the metadata as having
4681 * If there is a min_offset_diff, these are adjusted either by
4682 * increasing the safepos/readpos if diff is negative, or
4683 * increasing writepos if diff is positive.
4684 * If 'readpos' is then behind 'writepos', there is no way that we can
4685 * ensure safety in the face of a crash - that must be done by userspace
4686 * making a backup of the data. So in that case there is no particular
4687 * rush to update metadata.
4688 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4689 * update the metadata to advance 'safepos' to match 'readpos' so that
4690 * we can be safe in the event of a crash.
4691 * So we insist on updating metadata if safepos is behind writepos and
4692 * readpos is beyond writepos.
4693 * In any case, update the metadata every 10 seconds.
4694 * Maybe that number should be configurable, but I'm not sure it is
4695 * worth it.... maybe it could be a multiple of safemode_delay???
4697 if (conf->min_offset_diff < 0) {
4698 safepos += -conf->min_offset_diff;
4699 readpos += -conf->min_offset_diff;
4701 writepos += conf->min_offset_diff;
4703 if ((mddev->reshape_backwards
4704 ? (safepos > writepos && readpos < writepos)
4705 : (safepos < writepos && readpos > writepos)) ||
4706 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4707 /* Cannot proceed until we've updated the superblock... */
4708 wait_event(conf->wait_for_overlap,
4709 atomic_read(&conf->reshape_stripes)==0);
4710 mddev->reshape_position = conf->reshape_progress;
4711 mddev->curr_resync_completed = sector_nr;
4712 conf->reshape_checkpoint = jiffies;
4713 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4714 md_wakeup_thread(mddev->thread);
4715 wait_event(mddev->sb_wait, mddev->flags == 0 ||
4716 kthread_should_stop());
4717 spin_lock_irq(&conf->device_lock);
4718 conf->reshape_safe = mddev->reshape_position;
4719 spin_unlock_irq(&conf->device_lock);
4720 wake_up(&conf->wait_for_overlap);
4721 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4724 INIT_LIST_HEAD(&stripes);
4725 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
4727 int skipped_disk = 0;
4728 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
4729 set_bit(STRIPE_EXPANDING, &sh->state);
4730 atomic_inc(&conf->reshape_stripes);
4731 /* If any of this stripe is beyond the end of the old
4732 * array, then we need to zero those blocks
4734 for (j=sh->disks; j--;) {
4736 if (j == sh->pd_idx)
4738 if (conf->level == 6 &&
4741 s = compute_blocknr(sh, j, 0);
4742 if (s < raid5_size(mddev, 0, 0)) {
4746 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4747 set_bit(R5_Expanded, &sh->dev[j].flags);
4748 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4750 if (!skipped_disk) {
4751 set_bit(STRIPE_EXPAND_READY, &sh->state);
4752 set_bit(STRIPE_HANDLE, &sh->state);
4754 list_add(&sh->lru, &stripes);
4756 spin_lock_irq(&conf->device_lock);
4757 if (mddev->reshape_backwards)
4758 conf->reshape_progress -= reshape_sectors * new_data_disks;
4760 conf->reshape_progress += reshape_sectors * new_data_disks;
4761 spin_unlock_irq(&conf->device_lock);
4762 /* Ok, those stripe are ready. We can start scheduling
4763 * reads on the source stripes.
4764 * The source stripes are determined by mapping the first and last
4765 * block on the destination stripes.
4768 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
4771 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
4772 * new_data_disks - 1),
4774 if (last_sector >= mddev->dev_sectors)
4775 last_sector = mddev->dev_sectors - 1;
4776 while (first_sector <= last_sector) {
4777 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
4778 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4779 set_bit(STRIPE_HANDLE, &sh->state);
4781 first_sector += STRIPE_SECTORS;
4783 /* Now that the sources are clearly marked, we can release
4784 * the destination stripes
4786 while (!list_empty(&stripes)) {
4787 sh = list_entry(stripes.next, struct stripe_head, lru);
4788 list_del_init(&sh->lru);
4791 /* If this takes us to the resync_max point where we have to pause,
4792 * then we need to write out the superblock.
4794 sector_nr += reshape_sectors;
4795 if ((sector_nr - mddev->curr_resync_completed) * 2
4796 >= mddev->resync_max - mddev->curr_resync_completed) {
4797 /* Cannot proceed until we've updated the superblock... */
4798 wait_event(conf->wait_for_overlap,
4799 atomic_read(&conf->reshape_stripes) == 0);
4800 mddev->reshape_position = conf->reshape_progress;
4801 mddev->curr_resync_completed = sector_nr;
4802 conf->reshape_checkpoint = jiffies;
4803 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4804 md_wakeup_thread(mddev->thread);
4805 wait_event(mddev->sb_wait,
4806 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4807 || kthread_should_stop());
4808 spin_lock_irq(&conf->device_lock);
4809 conf->reshape_safe = mddev->reshape_position;
4810 spin_unlock_irq(&conf->device_lock);
4811 wake_up(&conf->wait_for_overlap);
4812 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4814 return reshape_sectors;
4817 /* FIXME go_faster isn't used */
4818 static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
4820 struct r5conf *conf = mddev->private;
4821 struct stripe_head *sh;
4822 sector_t max_sector = mddev->dev_sectors;
4823 sector_t sync_blocks;
4824 int still_degraded = 0;
4827 if (sector_nr >= max_sector) {
4828 /* just being told to finish up .. nothing much to do */
4830 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4835 if (mddev->curr_resync < max_sector) /* aborted */
4836 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4838 else /* completed sync */
4840 bitmap_close_sync(mddev->bitmap);
4845 /* Allow raid5_quiesce to complete */
4846 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4848 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4849 return reshape_request(mddev, sector_nr, skipped);
4851 /* No need to check resync_max as we never do more than one
4852 * stripe, and as resync_max will always be on a chunk boundary,
4853 * if the check in md_do_sync didn't fire, there is no chance
4854 * of overstepping resync_max here
4857 /* if there is too many failed drives and we are trying
4858 * to resync, then assert that we are finished, because there is
4859 * nothing we can do.
4861 if (mddev->degraded >= conf->max_degraded &&
4862 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4863 sector_t rv = mddev->dev_sectors - sector_nr;
4867 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
4869 !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
4870 sync_blocks >= STRIPE_SECTORS) {
4871 /* we can skip this block, and probably more */
4872 sync_blocks /= STRIPE_SECTORS;
4874 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4877 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4879 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
4881 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
4882 /* make sure we don't swamp the stripe cache if someone else
4883 * is trying to get access
4885 schedule_timeout_uninterruptible(1);
4887 /* Need to check if array will still be degraded after recovery/resync
4888 * We don't need to check the 'failed' flag as when that gets set,
4891 for (i = 0; i < conf->raid_disks; i++)
4892 if (conf->disks[i].rdev == NULL)
4895 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4897 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
4902 return STRIPE_SECTORS;
4905 static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
4907 /* We may not be able to submit a whole bio at once as there
4908 * may not be enough stripe_heads available.
4909 * We cannot pre-allocate enough stripe_heads as we may need
4910 * more than exist in the cache (if we allow ever large chunks).
4911 * So we do one stripe head at a time and record in
4912 * ->bi_hw_segments how many have been done.
4914 * We *know* that this entire raid_bio is in one chunk, so
4915 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4917 struct stripe_head *sh;
4919 sector_t sector, logical_sector, last_sector;
4924 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4925 sector = raid5_compute_sector(conf, logical_sector,
4927 last_sector = bio_end_sector(raid_bio);
4929 for (; logical_sector < last_sector;
4930 logical_sector += STRIPE_SECTORS,
4931 sector += STRIPE_SECTORS,
4934 if (scnt < raid5_bi_processed_stripes(raid_bio))
4935 /* already done this stripe */
4938 sh = get_active_stripe(conf, sector, 0, 1, 0);
4941 /* failed to get a stripe - must wait */
4942 raid5_set_bi_processed_stripes(raid_bio, scnt);
4943 conf->retry_read_aligned = raid_bio;
4947 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4949 raid5_set_bi_processed_stripes(raid_bio, scnt);
4950 conf->retry_read_aligned = raid_bio;
4954 set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
4959 remaining = raid5_dec_bi_active_stripes(raid_bio);
4960 if (remaining == 0) {
4961 trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
4963 bio_endio(raid_bio, 0);
4965 if (atomic_dec_and_test(&conf->active_aligned_reads))
4966 wake_up(&conf->wait_for_stripe);
4970 static int handle_active_stripes(struct r5conf *conf, int group,
4971 struct r5worker *worker)
4973 struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
4974 int i, batch_size = 0;
4976 while (batch_size < MAX_STRIPE_BATCH &&
4977 (sh = __get_priority_stripe(conf, group)) != NULL)
4978 batch[batch_size++] = sh;
4980 if (batch_size == 0)
4982 spin_unlock_irq(&conf->device_lock);
4984 for (i = 0; i < batch_size; i++)
4985 handle_stripe(batch[i]);
4989 spin_lock_irq(&conf->device_lock);
4990 for (i = 0; i < batch_size; i++)
4991 __release_stripe(conf, batch[i]);
4995 static void raid5_do_work(struct work_struct *work)
4997 struct r5worker *worker = container_of(work, struct r5worker, work);
4998 struct r5worker_group *group = worker->group;
4999 struct r5conf *conf = group->conf;
5000 int group_id = group - conf->worker_groups;
5002 struct blk_plug plug;
5004 pr_debug("+++ raid5worker active\n");
5006 blk_start_plug(&plug);
5008 spin_lock_irq(&conf->device_lock);
5010 int batch_size, released;
5012 released = release_stripe_list(conf);
5014 batch_size = handle_active_stripes(conf, group_id, worker);
5015 worker->working = false;
5016 if (!batch_size && !released)
5018 handled += batch_size;
5020 pr_debug("%d stripes handled\n", handled);
5022 spin_unlock_irq(&conf->device_lock);
5023 blk_finish_plug(&plug);
5025 pr_debug("--- raid5worker inactive\n");
5029 * This is our raid5 kernel thread.
5031 * We scan the hash table for stripes which can be handled now.
5032 * During the scan, completed stripes are saved for us by the interrupt
5033 * handler, so that they will not have to wait for our next wakeup.
5035 static void raid5d(struct md_thread *thread)
5037 struct mddev *mddev = thread->mddev;
5038 struct r5conf *conf = mddev->private;
5040 struct blk_plug plug;
5042 pr_debug("+++ raid5d active\n");
5044 md_check_recovery(mddev);
5046 blk_start_plug(&plug);
5048 spin_lock_irq(&conf->device_lock);
5051 int batch_size, released;
5053 released = release_stripe_list(conf);
5056 !list_empty(&conf->bitmap_list)) {
5057 /* Now is a good time to flush some bitmap updates */
5059 spin_unlock_irq(&conf->device_lock);
5060 bitmap_unplug(mddev->bitmap);
5061 spin_lock_irq(&conf->device_lock);
5062 conf->seq_write = conf->seq_flush;
5063 activate_bit_delay(conf);
5065 raid5_activate_delayed(conf);
5067 while ((bio = remove_bio_from_retry(conf))) {
5069 spin_unlock_irq(&conf->device_lock);
5070 ok = retry_aligned_read(conf, bio);
5071 spin_lock_irq(&conf->device_lock);
5077 batch_size = handle_active_stripes(conf, ANY_GROUP, NULL);
5078 if (!batch_size && !released)
5080 handled += batch_size;
5082 if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
5083 spin_unlock_irq(&conf->device_lock);
5084 md_check_recovery(mddev);
5085 spin_lock_irq(&conf->device_lock);
5088 pr_debug("%d stripes handled\n", handled);
5090 spin_unlock_irq(&conf->device_lock);
5092 async_tx_issue_pending_all();
5093 blk_finish_plug(&plug);
5095 pr_debug("--- raid5d inactive\n");
5099 raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
5101 struct r5conf *conf = mddev->private;
5103 return sprintf(page, "%d\n", conf->max_nr_stripes);
5109 raid5_set_cache_size(struct mddev *mddev, int size)
5111 struct r5conf *conf = mddev->private;
5114 if (size <= 16 || size > 32768)
5116 while (size < conf->max_nr_stripes) {
5117 if (drop_one_stripe(conf))
5118 conf->max_nr_stripes--;
5122 err = md_allow_write(mddev);
5125 while (size > conf->max_nr_stripes) {
5126 if (grow_one_stripe(conf))
5127 conf->max_nr_stripes++;
5132 EXPORT_SYMBOL(raid5_set_cache_size);
5135 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
5137 struct r5conf *conf = mddev->private;
5141 if (len >= PAGE_SIZE)
5146 if (kstrtoul(page, 10, &new))
5148 err = raid5_set_cache_size(mddev, new);
5154 static struct md_sysfs_entry
5155 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
5156 raid5_show_stripe_cache_size,
5157 raid5_store_stripe_cache_size);
5160 raid5_show_preread_threshold(struct mddev *mddev, char *page)
5162 struct r5conf *conf = mddev->private;
5164 return sprintf(page, "%d\n", conf->bypass_threshold);
5170 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
5172 struct r5conf *conf = mddev->private;
5174 if (len >= PAGE_SIZE)
5179 if (kstrtoul(page, 10, &new))
5181 if (new > conf->max_nr_stripes)
5183 conf->bypass_threshold = new;
5187 static struct md_sysfs_entry
5188 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
5190 raid5_show_preread_threshold,
5191 raid5_store_preread_threshold);
5194 stripe_cache_active_show(struct mddev *mddev, char *page)
5196 struct r5conf *conf = mddev->private;
5198 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
5203 static struct md_sysfs_entry
5204 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
5207 raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
5209 struct r5conf *conf = mddev->private;
5211 return sprintf(page, "%d\n", conf->worker_cnt_per_group);
5216 static int alloc_thread_groups(struct r5conf *conf, int cnt);
5218 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
5220 struct r5conf *conf = mddev->private;
5223 struct r5worker_group *old_groups;
5226 if (len >= PAGE_SIZE)
5231 if (kstrtoul(page, 10, &new))
5234 if (new == conf->worker_cnt_per_group)
5237 mddev_suspend(mddev);
5239 old_groups = conf->worker_groups;
5240 old_group_cnt = conf->worker_cnt_per_group;
5242 conf->worker_groups = NULL;
5243 err = alloc_thread_groups(conf, new);
5245 conf->worker_groups = old_groups;
5246 conf->worker_cnt_per_group = old_group_cnt;
5249 kfree(old_groups[0].workers);
5253 mddev_resume(mddev);
5260 static struct md_sysfs_entry
5261 raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
5262 raid5_show_group_thread_cnt,
5263 raid5_store_group_thread_cnt);
5265 static struct attribute *raid5_attrs[] = {
5266 &raid5_stripecache_size.attr,
5267 &raid5_stripecache_active.attr,
5268 &raid5_preread_bypass_threshold.attr,
5269 &raid5_group_thread_cnt.attr,
5272 static struct attribute_group raid5_attrs_group = {
5274 .attrs = raid5_attrs,
5277 static int alloc_thread_groups(struct r5conf *conf, int cnt)
5281 struct r5worker *workers;
5283 conf->worker_cnt_per_group = cnt;
5285 conf->worker_groups = NULL;
5288 conf->group_cnt = num_possible_nodes();
5289 size = sizeof(struct r5worker) * cnt;
5290 workers = kzalloc(size * conf->group_cnt, GFP_NOIO);
5291 conf->worker_groups = kzalloc(sizeof(struct r5worker_group) *
5292 conf->group_cnt, GFP_NOIO);
5293 if (!conf->worker_groups || !workers) {
5295 kfree(conf->worker_groups);
5296 conf->worker_groups = NULL;
5300 for (i = 0; i < conf->group_cnt; i++) {
5301 struct r5worker_group *group;
5303 group = &conf->worker_groups[i];
5304 INIT_LIST_HEAD(&group->handle_list);
5306 group->workers = workers + i * cnt;
5308 for (j = 0; j < cnt; j++) {
5309 group->workers[j].group = group;
5310 INIT_WORK(&group->workers[j].work, raid5_do_work);
5317 static void free_thread_groups(struct r5conf *conf)
5319 if (conf->worker_groups)
5320 kfree(conf->worker_groups[0].workers);
5321 kfree(conf->worker_groups);
5322 conf->worker_groups = NULL;
5326 raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
5328 struct r5conf *conf = mddev->private;
5331 sectors = mddev->dev_sectors;
5333 /* size is defined by the smallest of previous and new size */
5334 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
5336 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
5337 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
5338 return sectors * (raid_disks - conf->max_degraded);
5341 static void raid5_free_percpu(struct r5conf *conf)
5343 struct raid5_percpu *percpu;
5350 for_each_possible_cpu(cpu) {
5351 percpu = per_cpu_ptr(conf->percpu, cpu);
5352 safe_put_page(percpu->spare_page);
5353 kfree(percpu->scribble);
5355 #ifdef CONFIG_HOTPLUG_CPU
5356 unregister_cpu_notifier(&conf->cpu_notify);
5360 free_percpu(conf->percpu);
5363 static void free_conf(struct r5conf *conf)
5365 free_thread_groups(conf);
5366 shrink_stripes(conf);
5367 raid5_free_percpu(conf);
5369 kfree(conf->stripe_hashtbl);
5373 #ifdef CONFIG_HOTPLUG_CPU
5374 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
5377 struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify);
5378 long cpu = (long)hcpu;
5379 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
5382 case CPU_UP_PREPARE:
5383 case CPU_UP_PREPARE_FROZEN:
5384 if (conf->level == 6 && !percpu->spare_page)
5385 percpu->spare_page = alloc_page(GFP_KERNEL);
5386 if (!percpu->scribble)
5387 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
5389 if (!percpu->scribble ||
5390 (conf->level == 6 && !percpu->spare_page)) {
5391 safe_put_page(percpu->spare_page);
5392 kfree(percpu->scribble);
5393 pr_err("%s: failed memory allocation for cpu%ld\n",
5395 return notifier_from_errno(-ENOMEM);
5399 case CPU_DEAD_FROZEN:
5400 safe_put_page(percpu->spare_page);
5401 kfree(percpu->scribble);
5402 percpu->spare_page = NULL;
5403 percpu->scribble = NULL;
5412 static int raid5_alloc_percpu(struct r5conf *conf)
5415 struct page *spare_page;
5416 struct raid5_percpu __percpu *allcpus;
5420 allcpus = alloc_percpu(struct raid5_percpu);
5423 conf->percpu = allcpus;
5427 for_each_present_cpu(cpu) {
5428 if (conf->level == 6) {
5429 spare_page = alloc_page(GFP_KERNEL);
5434 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
5436 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
5441 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
5443 #ifdef CONFIG_HOTPLUG_CPU
5444 conf->cpu_notify.notifier_call = raid456_cpu_notify;
5445 conf->cpu_notify.priority = 0;
5447 err = register_cpu_notifier(&conf->cpu_notify);
5454 static struct r5conf *setup_conf(struct mddev *mddev)
5456 struct r5conf *conf;
5457 int raid_disk, memory, max_disks;
5458 struct md_rdev *rdev;
5459 struct disk_info *disk;
5462 if (mddev->new_level != 5
5463 && mddev->new_level != 4
5464 && mddev->new_level != 6) {
5465 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5466 mdname(mddev), mddev->new_level);
5467 return ERR_PTR(-EIO);
5469 if ((mddev->new_level == 5
5470 && !algorithm_valid_raid5(mddev->new_layout)) ||
5471 (mddev->new_level == 6
5472 && !algorithm_valid_raid6(mddev->new_layout))) {
5473 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
5474 mdname(mddev), mddev->new_layout);
5475 return ERR_PTR(-EIO);
5477 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
5478 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5479 mdname(mddev), mddev->raid_disks);
5480 return ERR_PTR(-EINVAL);
5483 if (!mddev->new_chunk_sectors ||
5484 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
5485 !is_power_of_2(mddev->new_chunk_sectors)) {
5486 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
5487 mdname(mddev), mddev->new_chunk_sectors << 9);
5488 return ERR_PTR(-EINVAL);
5491 conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
5494 /* Don't enable multi-threading by default*/
5495 if (alloc_thread_groups(conf, 0))
5497 spin_lock_init(&conf->device_lock);
5498 seqcount_init(&conf->gen_lock);
5499 init_waitqueue_head(&conf->wait_for_stripe);
5500 init_waitqueue_head(&conf->wait_for_overlap);
5501 INIT_LIST_HEAD(&conf->handle_list);
5502 INIT_LIST_HEAD(&conf->hold_list);
5503 INIT_LIST_HEAD(&conf->delayed_list);
5504 INIT_LIST_HEAD(&conf->bitmap_list);
5505 INIT_LIST_HEAD(&conf->inactive_list);
5506 init_llist_head(&conf->released_stripes);
5507 atomic_set(&conf->active_stripes, 0);
5508 atomic_set(&conf->preread_active_stripes, 0);
5509 atomic_set(&conf->active_aligned_reads, 0);
5510 conf->bypass_threshold = BYPASS_THRESHOLD;
5511 conf->recovery_disabled = mddev->recovery_disabled - 1;
5513 conf->raid_disks = mddev->raid_disks;
5514 if (mddev->reshape_position == MaxSector)
5515 conf->previous_raid_disks = mddev->raid_disks;
5517 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
5518 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
5519 conf->scribble_len = scribble_len(max_disks);
5521 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
5526 conf->mddev = mddev;
5528 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
5531 conf->level = mddev->new_level;
5532 if (raid5_alloc_percpu(conf) != 0)
5535 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
5537 rdev_for_each(rdev, mddev) {
5538 raid_disk = rdev->raid_disk;
5539 if (raid_disk >= max_disks
5542 disk = conf->disks + raid_disk;
5544 if (test_bit(Replacement, &rdev->flags)) {
5545 if (disk->replacement)
5547 disk->replacement = rdev;
5554 if (test_bit(In_sync, &rdev->flags)) {
5555 char b[BDEVNAME_SIZE];
5556 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
5558 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
5559 } else if (rdev->saved_raid_disk != raid_disk)
5560 /* Cannot rely on bitmap to complete recovery */
5564 conf->chunk_sectors = mddev->new_chunk_sectors;
5565 conf->level = mddev->new_level;
5566 if (conf->level == 6)
5567 conf->max_degraded = 2;
5569 conf->max_degraded = 1;
5570 conf->algorithm = mddev->new_layout;
5571 conf->max_nr_stripes = NR_STRIPES;
5572 conf->reshape_progress = mddev->reshape_position;
5573 if (conf->reshape_progress != MaxSector) {
5574 conf->prev_chunk_sectors = mddev->chunk_sectors;
5575 conf->prev_algo = mddev->layout;
5578 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
5579 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
5580 if (grow_stripes(conf, conf->max_nr_stripes)) {
5582 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5583 mdname(mddev), memory);
5586 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
5587 mdname(mddev), memory);
5589 sprintf(pers_name, "raid%d", mddev->new_level);
5590 conf->thread = md_register_thread(raid5d, mddev, pers_name);
5591 if (!conf->thread) {
5593 "md/raid:%s: couldn't allocate thread.\n",
5603 return ERR_PTR(-EIO);
5605 return ERR_PTR(-ENOMEM);
5609 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
5612 case ALGORITHM_PARITY_0:
5613 if (raid_disk < max_degraded)
5616 case ALGORITHM_PARITY_N:
5617 if (raid_disk >= raid_disks - max_degraded)
5620 case ALGORITHM_PARITY_0_6:
5621 if (raid_disk == 0 ||
5622 raid_disk == raid_disks - 1)
5625 case ALGORITHM_LEFT_ASYMMETRIC_6:
5626 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5627 case ALGORITHM_LEFT_SYMMETRIC_6:
5628 case ALGORITHM_RIGHT_SYMMETRIC_6:
5629 if (raid_disk == raid_disks - 1)
5635 static int run(struct mddev *mddev)
5637 struct r5conf *conf;
5638 int working_disks = 0;
5639 int dirty_parity_disks = 0;
5640 struct md_rdev *rdev;
5641 sector_t reshape_offset = 0;
5643 long long min_offset_diff = 0;
5646 if (mddev->recovery_cp != MaxSector)
5647 printk(KERN_NOTICE "md/raid:%s: not clean"
5648 " -- starting background reconstruction\n",
5651 rdev_for_each(rdev, mddev) {
5653 if (rdev->raid_disk < 0)
5655 diff = (rdev->new_data_offset - rdev->data_offset);
5657 min_offset_diff = diff;
5659 } else if (mddev->reshape_backwards &&
5660 diff < min_offset_diff)
5661 min_offset_diff = diff;
5662 else if (!mddev->reshape_backwards &&
5663 diff > min_offset_diff)
5664 min_offset_diff = diff;
5667 if (mddev->reshape_position != MaxSector) {
5668 /* Check that we can continue the reshape.
5669 * Difficulties arise if the stripe we would write to
5670 * next is at or after the stripe we would read from next.
5671 * For a reshape that changes the number of devices, this
5672 * is only possible for a very short time, and mdadm makes
5673 * sure that time appears to have past before assembling
5674 * the array. So we fail if that time hasn't passed.
5675 * For a reshape that keeps the number of devices the same
5676 * mdadm must be monitoring the reshape can keeping the
5677 * critical areas read-only and backed up. It will start
5678 * the array in read-only mode, so we check for that.
5680 sector_t here_new, here_old;
5682 int max_degraded = (mddev->level == 6 ? 2 : 1);
5684 if (mddev->new_level != mddev->level) {
5685 printk(KERN_ERR "md/raid:%s: unsupported reshape "
5686 "required - aborting.\n",
5690 old_disks = mddev->raid_disks - mddev->delta_disks;
5691 /* reshape_position must be on a new-stripe boundary, and one
5692 * further up in new geometry must map after here in old
5695 here_new = mddev->reshape_position;
5696 if (sector_div(here_new, mddev->new_chunk_sectors *
5697 (mddev->raid_disks - max_degraded))) {
5698 printk(KERN_ERR "md/raid:%s: reshape_position not "
5699 "on a stripe boundary\n", mdname(mddev));
5702 reshape_offset = here_new * mddev->new_chunk_sectors;
5703 /* here_new is the stripe we will write to */
5704 here_old = mddev->reshape_position;
5705 sector_div(here_old, mddev->chunk_sectors *
5706 (old_disks-max_degraded));
5707 /* here_old is the first stripe that we might need to read
5709 if (mddev->delta_disks == 0) {
5710 if ((here_new * mddev->new_chunk_sectors !=
5711 here_old * mddev->chunk_sectors)) {
5712 printk(KERN_ERR "md/raid:%s: reshape position is"
5713 " confused - aborting\n", mdname(mddev));
5716 /* We cannot be sure it is safe to start an in-place
5717 * reshape. It is only safe if user-space is monitoring
5718 * and taking constant backups.
5719 * mdadm always starts a situation like this in
5720 * readonly mode so it can take control before
5721 * allowing any writes. So just check for that.
5723 if (abs(min_offset_diff) >= mddev->chunk_sectors &&
5724 abs(min_offset_diff) >= mddev->new_chunk_sectors)
5725 /* not really in-place - so OK */;
5726 else if (mddev->ro == 0) {
5727 printk(KERN_ERR "md/raid:%s: in-place reshape "
5728 "must be started in read-only mode "
5733 } else if (mddev->reshape_backwards
5734 ? (here_new * mddev->new_chunk_sectors + min_offset_diff <=
5735 here_old * mddev->chunk_sectors)
5736 : (here_new * mddev->new_chunk_sectors >=
5737 here_old * mddev->chunk_sectors + (-min_offset_diff))) {
5738 /* Reading from the same stripe as writing to - bad */
5739 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
5740 "auto-recovery - aborting.\n",
5744 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
5746 /* OK, we should be able to continue; */
5748 BUG_ON(mddev->level != mddev->new_level);
5749 BUG_ON(mddev->layout != mddev->new_layout);
5750 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
5751 BUG_ON(mddev->delta_disks != 0);
5754 if (mddev->private == NULL)
5755 conf = setup_conf(mddev);
5757 conf = mddev->private;
5760 return PTR_ERR(conf);
5762 conf->min_offset_diff = min_offset_diff;
5763 mddev->thread = conf->thread;
5764 conf->thread = NULL;
5765 mddev->private = conf;
5767 for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
5769 rdev = conf->disks[i].rdev;
5770 if (!rdev && conf->disks[i].replacement) {
5771 /* The replacement is all we have yet */
5772 rdev = conf->disks[i].replacement;
5773 conf->disks[i].replacement = NULL;
5774 clear_bit(Replacement, &rdev->flags);
5775 conf->disks[i].rdev = rdev;
5779 if (conf->disks[i].replacement &&
5780 conf->reshape_progress != MaxSector) {
5781 /* replacements and reshape simply do not mix. */
5782 printk(KERN_ERR "md: cannot handle concurrent "
5783 "replacement and reshape.\n");
5786 if (test_bit(In_sync, &rdev->flags)) {
5790 /* This disc is not fully in-sync. However if it
5791 * just stored parity (beyond the recovery_offset),
5792 * when we don't need to be concerned about the
5793 * array being dirty.
5794 * When reshape goes 'backwards', we never have
5795 * partially completed devices, so we only need
5796 * to worry about reshape going forwards.
5798 /* Hack because v0.91 doesn't store recovery_offset properly. */
5799 if (mddev->major_version == 0 &&
5800 mddev->minor_version > 90)
5801 rdev->recovery_offset = reshape_offset;
5803 if (rdev->recovery_offset < reshape_offset) {
5804 /* We need to check old and new layout */
5805 if (!only_parity(rdev->raid_disk,
5808 conf->max_degraded))
5811 if (!only_parity(rdev->raid_disk,
5813 conf->previous_raid_disks,
5814 conf->max_degraded))
5816 dirty_parity_disks++;
5820 * 0 for a fully functional array, 1 or 2 for a degraded array.
5822 mddev->degraded = calc_degraded(conf);
5824 if (has_failed(conf)) {
5825 printk(KERN_ERR "md/raid:%s: not enough operational devices"
5826 " (%d/%d failed)\n",
5827 mdname(mddev), mddev->degraded, conf->raid_disks);
5831 /* device size must be a multiple of chunk size */
5832 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
5833 mddev->resync_max_sectors = mddev->dev_sectors;
5835 if (mddev->degraded > dirty_parity_disks &&
5836 mddev->recovery_cp != MaxSector) {
5837 if (mddev->ok_start_degraded)
5839 "md/raid:%s: starting dirty degraded array"
5840 " - data corruption possible.\n",
5844 "md/raid:%s: cannot start dirty degraded array.\n",
5850 if (mddev->degraded == 0)
5851 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5852 " devices, algorithm %d\n", mdname(mddev), conf->level,
5853 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5856 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5857 " out of %d devices, algorithm %d\n",
5858 mdname(mddev), conf->level,
5859 mddev->raid_disks - mddev->degraded,
5860 mddev->raid_disks, mddev->new_layout);
5862 print_raid5_conf(conf);
5864 if (conf->reshape_progress != MaxSector) {
5865 conf->reshape_safe = conf->reshape_progress;
5866 atomic_set(&conf->reshape_stripes, 0);
5867 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5868 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5869 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5870 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5871 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5876 /* Ok, everything is just fine now */
5877 if (mddev->to_remove == &raid5_attrs_group)
5878 mddev->to_remove = NULL;
5879 else if (mddev->kobj.sd &&
5880 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5882 "raid5: failed to create sysfs attributes for %s\n",
5884 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5888 bool discard_supported = true;
5889 /* read-ahead size must cover two whole stripes, which
5890 * is 2 * (datadisks) * chunksize where 'n' is the
5891 * number of raid devices
5893 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5894 int stripe = data_disks *
5895 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
5896 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5897 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5899 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
5901 mddev->queue->backing_dev_info.congested_data = mddev;
5902 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
5904 chunk_size = mddev->chunk_sectors << 9;
5905 blk_queue_io_min(mddev->queue, chunk_size);
5906 blk_queue_io_opt(mddev->queue, chunk_size *
5907 (conf->raid_disks - conf->max_degraded));
5909 * We can only discard a whole stripe. It doesn't make sense to
5910 * discard data disk but write parity disk
5912 stripe = stripe * PAGE_SIZE;
5913 /* Round up to power of 2, as discard handling
5914 * currently assumes that */
5915 while ((stripe-1) & stripe)
5916 stripe = (stripe | (stripe-1)) + 1;
5917 mddev->queue->limits.discard_alignment = stripe;
5918 mddev->queue->limits.discard_granularity = stripe;
5920 * unaligned part of discard request will be ignored, so can't
5921 * guarantee discard_zerors_data
5923 mddev->queue->limits.discard_zeroes_data = 0;
5925 blk_queue_max_write_same_sectors(mddev->queue, 0);
5927 rdev_for_each(rdev, mddev) {
5928 disk_stack_limits(mddev->gendisk, rdev->bdev,
5929 rdev->data_offset << 9);
5930 disk_stack_limits(mddev->gendisk, rdev->bdev,
5931 rdev->new_data_offset << 9);
5933 * discard_zeroes_data is required, otherwise data
5934 * could be lost. Consider a scenario: discard a stripe
5935 * (the stripe could be inconsistent if
5936 * discard_zeroes_data is 0); write one disk of the
5937 * stripe (the stripe could be inconsistent again
5938 * depending on which disks are used to calculate
5939 * parity); the disk is broken; The stripe data of this
5942 if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
5943 !bdev_get_queue(rdev->bdev)->
5944 limits.discard_zeroes_data)
5945 discard_supported = false;
5948 if (discard_supported &&
5949 mddev->queue->limits.max_discard_sectors >= stripe &&
5950 mddev->queue->limits.discard_granularity >= stripe)
5951 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
5954 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
5960 md_unregister_thread(&mddev->thread);
5961 print_raid5_conf(conf);
5963 mddev->private = NULL;
5964 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
5968 static int stop(struct mddev *mddev)
5970 struct r5conf *conf = mddev->private;
5972 md_unregister_thread(&mddev->thread);
5974 mddev->queue->backing_dev_info.congested_fn = NULL;
5976 mddev->private = NULL;
5977 mddev->to_remove = &raid5_attrs_group;
5981 static void status(struct seq_file *seq, struct mddev *mddev)
5983 struct r5conf *conf = mddev->private;
5986 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5987 mddev->chunk_sectors / 2, mddev->layout);
5988 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
5989 for (i = 0; i < conf->raid_disks; i++)
5990 seq_printf (seq, "%s",
5991 conf->disks[i].rdev &&
5992 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
5993 seq_printf (seq, "]");
5996 static void print_raid5_conf (struct r5conf *conf)
5999 struct disk_info *tmp;
6001 printk(KERN_DEBUG "RAID conf printout:\n");
6003 printk("(conf==NULL)\n");
6006 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
6008 conf->raid_disks - conf->mddev->degraded);
6010 for (i = 0; i < conf->raid_disks; i++) {
6011 char b[BDEVNAME_SIZE];
6012 tmp = conf->disks + i;
6014 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
6015 i, !test_bit(Faulty, &tmp->rdev->flags),
6016 bdevname(tmp->rdev->bdev, b));
6020 static int raid5_spare_active(struct mddev *mddev)
6023 struct r5conf *conf = mddev->private;
6024 struct disk_info *tmp;
6026 unsigned long flags;
6028 for (i = 0; i < conf->raid_disks; i++) {
6029 tmp = conf->disks + i;
6030 if (tmp->replacement
6031 && tmp->replacement->recovery_offset == MaxSector
6032 && !test_bit(Faulty, &tmp->replacement->flags)
6033 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
6034 /* Replacement has just become active. */
6036 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
6039 /* Replaced device not technically faulty,
6040 * but we need to be sure it gets removed
6041 * and never re-added.
6043 set_bit(Faulty, &tmp->rdev->flags);
6044 sysfs_notify_dirent_safe(
6045 tmp->rdev->sysfs_state);
6047 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
6048 } else if (tmp->rdev
6049 && tmp->rdev->recovery_offset == MaxSector
6050 && !test_bit(Faulty, &tmp->rdev->flags)
6051 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
6053 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
6056 spin_lock_irqsave(&conf->device_lock, flags);
6057 mddev->degraded = calc_degraded(conf);
6058 spin_unlock_irqrestore(&conf->device_lock, flags);
6059 print_raid5_conf(conf);
6063 static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
6065 struct r5conf *conf = mddev->private;
6067 int number = rdev->raid_disk;
6068 struct md_rdev **rdevp;
6069 struct disk_info *p = conf->disks + number;
6071 print_raid5_conf(conf);
6072 if (rdev == p->rdev)
6074 else if (rdev == p->replacement)
6075 rdevp = &p->replacement;
6079 if (number >= conf->raid_disks &&
6080 conf->reshape_progress == MaxSector)
6081 clear_bit(In_sync, &rdev->flags);
6083 if (test_bit(In_sync, &rdev->flags) ||
6084 atomic_read(&rdev->nr_pending)) {
6088 /* Only remove non-faulty devices if recovery
6091 if (!test_bit(Faulty, &rdev->flags) &&
6092 mddev->recovery_disabled != conf->recovery_disabled &&
6093 !has_failed(conf) &&
6094 (!p->replacement || p->replacement == rdev) &&
6095 number < conf->raid_disks) {
6101 if (atomic_read(&rdev->nr_pending)) {
6102 /* lost the race, try later */
6105 } else if (p->replacement) {
6106 /* We must have just cleared 'rdev' */
6107 p->rdev = p->replacement;
6108 clear_bit(Replacement, &p->replacement->flags);
6109 smp_mb(); /* Make sure other CPUs may see both as identical
6110 * but will never see neither - if they are careful
6112 p->replacement = NULL;
6113 clear_bit(WantReplacement, &rdev->flags);
6115 /* We might have just removed the Replacement as faulty-
6116 * clear the bit just in case
6118 clear_bit(WantReplacement, &rdev->flags);
6121 print_raid5_conf(conf);
6125 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
6127 struct r5conf *conf = mddev->private;
6130 struct disk_info *p;
6132 int last = conf->raid_disks - 1;
6134 if (mddev->recovery_disabled == conf->recovery_disabled)
6137 if (rdev->saved_raid_disk < 0 && has_failed(conf))
6138 /* no point adding a device */
6141 if (rdev->raid_disk >= 0)
6142 first = last = rdev->raid_disk;
6145 * find the disk ... but prefer rdev->saved_raid_disk
6148 if (rdev->saved_raid_disk >= 0 &&
6149 rdev->saved_raid_disk >= first &&
6150 conf->disks[rdev->saved_raid_disk].rdev == NULL)
6151 first = rdev->saved_raid_disk;
6153 for (disk = first; disk <= last; disk++) {
6154 p = conf->disks + disk;
6155 if (p->rdev == NULL) {
6156 clear_bit(In_sync, &rdev->flags);
6157 rdev->raid_disk = disk;
6159 if (rdev->saved_raid_disk != disk)
6161 rcu_assign_pointer(p->rdev, rdev);
6165 for (disk = first; disk <= last; disk++) {
6166 p = conf->disks + disk;
6167 if (test_bit(WantReplacement, &p->rdev->flags) &&
6168 p->replacement == NULL) {
6169 clear_bit(In_sync, &rdev->flags);
6170 set_bit(Replacement, &rdev->flags);
6171 rdev->raid_disk = disk;
6174 rcu_assign_pointer(p->replacement, rdev);
6179 print_raid5_conf(conf);
6183 static int raid5_resize(struct mddev *mddev, sector_t sectors)
6185 /* no resync is happening, and there is enough space
6186 * on all devices, so we can resize.
6187 * We need to make sure resync covers any new space.
6188 * If the array is shrinking we should possibly wait until
6189 * any io in the removed space completes, but it hardly seems
6193 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
6194 newsize = raid5_size(mddev, sectors, mddev->raid_disks);
6195 if (mddev->external_size &&
6196 mddev->array_sectors > newsize)
6198 if (mddev->bitmap) {
6199 int ret = bitmap_resize(mddev->bitmap, sectors, 0, 0);
6203 md_set_array_sectors(mddev, newsize);
6204 set_capacity(mddev->gendisk, mddev->array_sectors);
6205 revalidate_disk(mddev->gendisk);
6206 if (sectors > mddev->dev_sectors &&
6207 mddev->recovery_cp > mddev->dev_sectors) {
6208 mddev->recovery_cp = mddev->dev_sectors;
6209 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
6211 mddev->dev_sectors = sectors;
6212 mddev->resync_max_sectors = sectors;
6216 static int check_stripe_cache(struct mddev *mddev)
6218 /* Can only proceed if there are plenty of stripe_heads.
6219 * We need a minimum of one full stripe,, and for sensible progress
6220 * it is best to have about 4 times that.
6221 * If we require 4 times, then the default 256 4K stripe_heads will
6222 * allow for chunk sizes up to 256K, which is probably OK.
6223 * If the chunk size is greater, user-space should request more
6224 * stripe_heads first.
6226 struct r5conf *conf = mddev->private;
6227 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
6228 > conf->max_nr_stripes ||
6229 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
6230 > conf->max_nr_stripes) {
6231 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
6233 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
6240 static int check_reshape(struct mddev *mddev)
6242 struct r5conf *conf = mddev->private;
6244 if (mddev->delta_disks == 0 &&
6245 mddev->new_layout == mddev->layout &&
6246 mddev->new_chunk_sectors == mddev->chunk_sectors)
6247 return 0; /* nothing to do */
6248 if (has_failed(conf))
6250 if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
6251 /* We might be able to shrink, but the devices must
6252 * be made bigger first.
6253 * For raid6, 4 is the minimum size.
6254 * Otherwise 2 is the minimum
6257 if (mddev->level == 6)
6259 if (mddev->raid_disks + mddev->delta_disks < min)
6263 if (!check_stripe_cache(mddev))
6266 return resize_stripes(conf, (conf->previous_raid_disks
6267 + mddev->delta_disks));
6270 static int raid5_start_reshape(struct mddev *mddev)
6272 struct r5conf *conf = mddev->private;
6273 struct md_rdev *rdev;
6275 unsigned long flags;
6277 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
6280 if (!check_stripe_cache(mddev))
6283 if (has_failed(conf))
6286 rdev_for_each(rdev, mddev) {
6287 if (!test_bit(In_sync, &rdev->flags)
6288 && !test_bit(Faulty, &rdev->flags))
6292 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
6293 /* Not enough devices even to make a degraded array
6298 /* Refuse to reduce size of the array. Any reductions in
6299 * array size must be through explicit setting of array_size
6302 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
6303 < mddev->array_sectors) {
6304 printk(KERN_ERR "md/raid:%s: array size must be reduced "
6305 "before number of disks\n", mdname(mddev));
6309 atomic_set(&conf->reshape_stripes, 0);
6310 spin_lock_irq(&conf->device_lock);
6311 write_seqcount_begin(&conf->gen_lock);
6312 conf->previous_raid_disks = conf->raid_disks;
6313 conf->raid_disks += mddev->delta_disks;
6314 conf->prev_chunk_sectors = conf->chunk_sectors;
6315 conf->chunk_sectors = mddev->new_chunk_sectors;
6316 conf->prev_algo = conf->algorithm;
6317 conf->algorithm = mddev->new_layout;
6319 /* Code that selects data_offset needs to see the generation update
6320 * if reshape_progress has been set - so a memory barrier needed.
6323 if (mddev->reshape_backwards)
6324 conf->reshape_progress = raid5_size(mddev, 0, 0);
6326 conf->reshape_progress = 0;
6327 conf->reshape_safe = conf->reshape_progress;
6328 write_seqcount_end(&conf->gen_lock);
6329 spin_unlock_irq(&conf->device_lock);
6331 /* Now make sure any requests that proceeded on the assumption
6332 * the reshape wasn't running - like Discard or Read - have
6335 mddev_suspend(mddev);
6336 mddev_resume(mddev);
6338 /* Add some new drives, as many as will fit.
6339 * We know there are enough to make the newly sized array work.
6340 * Don't add devices if we are reducing the number of
6341 * devices in the array. This is because it is not possible
6342 * to correctly record the "partially reconstructed" state of
6343 * such devices during the reshape and confusion could result.
6345 if (mddev->delta_disks >= 0) {
6346 rdev_for_each(rdev, mddev)
6347 if (rdev->raid_disk < 0 &&
6348 !test_bit(Faulty, &rdev->flags)) {
6349 if (raid5_add_disk(mddev, rdev) == 0) {
6351 >= conf->previous_raid_disks)
6352 set_bit(In_sync, &rdev->flags);
6354 rdev->recovery_offset = 0;
6356 if (sysfs_link_rdev(mddev, rdev))
6357 /* Failure here is OK */;
6359 } else if (rdev->raid_disk >= conf->previous_raid_disks
6360 && !test_bit(Faulty, &rdev->flags)) {
6361 /* This is a spare that was manually added */
6362 set_bit(In_sync, &rdev->flags);
6365 /* When a reshape changes the number of devices,
6366 * ->degraded is measured against the larger of the
6367 * pre and post number of devices.
6369 spin_lock_irqsave(&conf->device_lock, flags);
6370 mddev->degraded = calc_degraded(conf);
6371 spin_unlock_irqrestore(&conf->device_lock, flags);
6373 mddev->raid_disks = conf->raid_disks;
6374 mddev->reshape_position = conf->reshape_progress;
6375 set_bit(MD_CHANGE_DEVS, &mddev->flags);
6377 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
6378 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
6379 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
6380 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
6381 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
6383 if (!mddev->sync_thread) {
6384 mddev->recovery = 0;
6385 spin_lock_irq(&conf->device_lock);
6386 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
6387 rdev_for_each(rdev, mddev)
6388 rdev->new_data_offset = rdev->data_offset;
6390 conf->reshape_progress = MaxSector;
6391 mddev->reshape_position = MaxSector;
6392 spin_unlock_irq(&conf->device_lock);
6395 conf->reshape_checkpoint = jiffies;
6396 md_wakeup_thread(mddev->sync_thread);
6397 md_new_event(mddev);
6401 /* This is called from the reshape thread and should make any
6402 * changes needed in 'conf'
6404 static void end_reshape(struct r5conf *conf)
6407 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
6408 struct md_rdev *rdev;
6410 spin_lock_irq(&conf->device_lock);
6411 conf->previous_raid_disks = conf->raid_disks;
6412 rdev_for_each(rdev, conf->mddev)
6413 rdev->data_offset = rdev->new_data_offset;
6415 conf->reshape_progress = MaxSector;
6416 spin_unlock_irq(&conf->device_lock);
6417 wake_up(&conf->wait_for_overlap);
6419 /* read-ahead size must cover two whole stripes, which is
6420 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6422 if (conf->mddev->queue) {
6423 int data_disks = conf->raid_disks - conf->max_degraded;
6424 int stripe = data_disks * ((conf->chunk_sectors << 9)
6426 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
6427 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
6432 /* This is called from the raid5d thread with mddev_lock held.
6433 * It makes config changes to the device.
6435 static void raid5_finish_reshape(struct mddev *mddev)
6437 struct r5conf *conf = mddev->private;
6439 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
6441 if (mddev->delta_disks > 0) {
6442 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
6443 set_capacity(mddev->gendisk, mddev->array_sectors);
6444 revalidate_disk(mddev->gendisk);
6447 spin_lock_irq(&conf->device_lock);
6448 mddev->degraded = calc_degraded(conf);
6449 spin_unlock_irq(&conf->device_lock);
6450 for (d = conf->raid_disks ;
6451 d < conf->raid_disks - mddev->delta_disks;
6453 struct md_rdev *rdev = conf->disks[d].rdev;
6455 clear_bit(In_sync, &rdev->flags);
6456 rdev = conf->disks[d].replacement;
6458 clear_bit(In_sync, &rdev->flags);
6461 mddev->layout = conf->algorithm;
6462 mddev->chunk_sectors = conf->chunk_sectors;
6463 mddev->reshape_position = MaxSector;
6464 mddev->delta_disks = 0;
6465 mddev->reshape_backwards = 0;
6469 static void raid5_quiesce(struct mddev *mddev, int state)
6471 struct r5conf *conf = mddev->private;
6474 case 2: /* resume for a suspend */
6475 wake_up(&conf->wait_for_overlap);
6478 case 1: /* stop all writes */
6479 spin_lock_irq(&conf->device_lock);
6480 /* '2' tells resync/reshape to pause so that all
6481 * active stripes can drain
6484 wait_event_lock_irq(conf->wait_for_stripe,
6485 atomic_read(&conf->active_stripes) == 0 &&
6486 atomic_read(&conf->active_aligned_reads) == 0,
6489 spin_unlock_irq(&conf->device_lock);
6490 /* allow reshape to continue */
6491 wake_up(&conf->wait_for_overlap);
6494 case 0: /* re-enable writes */
6495 spin_lock_irq(&conf->device_lock);
6497 wake_up(&conf->wait_for_stripe);
6498 wake_up(&conf->wait_for_overlap);
6499 spin_unlock_irq(&conf->device_lock);
6505 static void *raid45_takeover_raid0(struct mddev *mddev, int level)
6507 struct r0conf *raid0_conf = mddev->private;
6510 /* for raid0 takeover only one zone is supported */
6511 if (raid0_conf->nr_strip_zones > 1) {
6512 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6514 return ERR_PTR(-EINVAL);
6517 sectors = raid0_conf->strip_zone[0].zone_end;
6518 sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
6519 mddev->dev_sectors = sectors;
6520 mddev->new_level = level;
6521 mddev->new_layout = ALGORITHM_PARITY_N;
6522 mddev->new_chunk_sectors = mddev->chunk_sectors;
6523 mddev->raid_disks += 1;
6524 mddev->delta_disks = 1;
6525 /* make sure it will be not marked as dirty */
6526 mddev->recovery_cp = MaxSector;
6528 return setup_conf(mddev);
6532 static void *raid5_takeover_raid1(struct mddev *mddev)
6536 if (mddev->raid_disks != 2 ||
6537 mddev->degraded > 1)
6538 return ERR_PTR(-EINVAL);
6540 /* Should check if there are write-behind devices? */
6542 chunksect = 64*2; /* 64K by default */
6544 /* The array must be an exact multiple of chunksize */
6545 while (chunksect && (mddev->array_sectors & (chunksect-1)))
6548 if ((chunksect<<9) < STRIPE_SIZE)
6549 /* array size does not allow a suitable chunk size */
6550 return ERR_PTR(-EINVAL);
6552 mddev->new_level = 5;
6553 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
6554 mddev->new_chunk_sectors = chunksect;
6556 return setup_conf(mddev);
6559 static void *raid5_takeover_raid6(struct mddev *mddev)
6563 switch (mddev->layout) {
6564 case ALGORITHM_LEFT_ASYMMETRIC_6:
6565 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
6567 case ALGORITHM_RIGHT_ASYMMETRIC_6:
6568 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
6570 case ALGORITHM_LEFT_SYMMETRIC_6:
6571 new_layout = ALGORITHM_LEFT_SYMMETRIC;
6573 case ALGORITHM_RIGHT_SYMMETRIC_6:
6574 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
6576 case ALGORITHM_PARITY_0_6:
6577 new_layout = ALGORITHM_PARITY_0;
6579 case ALGORITHM_PARITY_N:
6580 new_layout = ALGORITHM_PARITY_N;
6583 return ERR_PTR(-EINVAL);
6585 mddev->new_level = 5;
6586 mddev->new_layout = new_layout;
6587 mddev->delta_disks = -1;
6588 mddev->raid_disks -= 1;
6589 return setup_conf(mddev);
6593 static int raid5_check_reshape(struct mddev *mddev)
6595 /* For a 2-drive array, the layout and chunk size can be changed
6596 * immediately as not restriping is needed.
6597 * For larger arrays we record the new value - after validation
6598 * to be used by a reshape pass.
6600 struct r5conf *conf = mddev->private;
6601 int new_chunk = mddev->new_chunk_sectors;
6603 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
6605 if (new_chunk > 0) {
6606 if (!is_power_of_2(new_chunk))
6608 if (new_chunk < (PAGE_SIZE>>9))
6610 if (mddev->array_sectors & (new_chunk-1))
6611 /* not factor of array size */
6615 /* They look valid */
6617 if (mddev->raid_disks == 2) {
6618 /* can make the change immediately */
6619 if (mddev->new_layout >= 0) {
6620 conf->algorithm = mddev->new_layout;
6621 mddev->layout = mddev->new_layout;
6623 if (new_chunk > 0) {
6624 conf->chunk_sectors = new_chunk ;
6625 mddev->chunk_sectors = new_chunk;
6627 set_bit(MD_CHANGE_DEVS, &mddev->flags);
6628 md_wakeup_thread(mddev->thread);
6630 return check_reshape(mddev);
6633 static int raid6_check_reshape(struct mddev *mddev)
6635 int new_chunk = mddev->new_chunk_sectors;
6637 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
6639 if (new_chunk > 0) {
6640 if (!is_power_of_2(new_chunk))
6642 if (new_chunk < (PAGE_SIZE >> 9))
6644 if (mddev->array_sectors & (new_chunk-1))
6645 /* not factor of array size */
6649 /* They look valid */
6650 return check_reshape(mddev);
6653 static void *raid5_takeover(struct mddev *mddev)
6655 /* raid5 can take over:
6656 * raid0 - if there is only one strip zone - make it a raid4 layout
6657 * raid1 - if there are two drives. We need to know the chunk size
6658 * raid4 - trivial - just use a raid4 layout.
6659 * raid6 - Providing it is a *_6 layout
6661 if (mddev->level == 0)
6662 return raid45_takeover_raid0(mddev, 5);
6663 if (mddev->level == 1)
6664 return raid5_takeover_raid1(mddev);
6665 if (mddev->level == 4) {
6666 mddev->new_layout = ALGORITHM_PARITY_N;
6667 mddev->new_level = 5;
6668 return setup_conf(mddev);
6670 if (mddev->level == 6)
6671 return raid5_takeover_raid6(mddev);
6673 return ERR_PTR(-EINVAL);
6676 static void *raid4_takeover(struct mddev *mddev)
6678 /* raid4 can take over:
6679 * raid0 - if there is only one strip zone
6680 * raid5 - if layout is right
6682 if (mddev->level == 0)
6683 return raid45_takeover_raid0(mddev, 4);
6684 if (mddev->level == 5 &&
6685 mddev->layout == ALGORITHM_PARITY_N) {
6686 mddev->new_layout = 0;
6687 mddev->new_level = 4;
6688 return setup_conf(mddev);
6690 return ERR_PTR(-EINVAL);
6693 static struct md_personality raid5_personality;
6695 static void *raid6_takeover(struct mddev *mddev)
6697 /* Currently can only take over a raid5. We map the
6698 * personality to an equivalent raid6 personality
6699 * with the Q block at the end.
6703 if (mddev->pers != &raid5_personality)
6704 return ERR_PTR(-EINVAL);
6705 if (mddev->degraded > 1)
6706 return ERR_PTR(-EINVAL);
6707 if (mddev->raid_disks > 253)
6708 return ERR_PTR(-EINVAL);
6709 if (mddev->raid_disks < 3)
6710 return ERR_PTR(-EINVAL);
6712 switch (mddev->layout) {
6713 case ALGORITHM_LEFT_ASYMMETRIC:
6714 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
6716 case ALGORITHM_RIGHT_ASYMMETRIC:
6717 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
6719 case ALGORITHM_LEFT_SYMMETRIC:
6720 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
6722 case ALGORITHM_RIGHT_SYMMETRIC:
6723 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
6725 case ALGORITHM_PARITY_0:
6726 new_layout = ALGORITHM_PARITY_0_6;
6728 case ALGORITHM_PARITY_N:
6729 new_layout = ALGORITHM_PARITY_N;
6732 return ERR_PTR(-EINVAL);
6734 mddev->new_level = 6;
6735 mddev->new_layout = new_layout;
6736 mddev->delta_disks = 1;
6737 mddev->raid_disks += 1;
6738 return setup_conf(mddev);
6742 static struct md_personality raid6_personality =
6746 .owner = THIS_MODULE,
6747 .make_request = make_request,
6751 .error_handler = error,
6752 .hot_add_disk = raid5_add_disk,
6753 .hot_remove_disk= raid5_remove_disk,
6754 .spare_active = raid5_spare_active,
6755 .sync_request = sync_request,
6756 .resize = raid5_resize,
6758 .check_reshape = raid6_check_reshape,
6759 .start_reshape = raid5_start_reshape,
6760 .finish_reshape = raid5_finish_reshape,
6761 .quiesce = raid5_quiesce,
6762 .takeover = raid6_takeover,
6764 static struct md_personality raid5_personality =
6768 .owner = THIS_MODULE,
6769 .make_request = make_request,
6773 .error_handler = error,
6774 .hot_add_disk = raid5_add_disk,
6775 .hot_remove_disk= raid5_remove_disk,
6776 .spare_active = raid5_spare_active,
6777 .sync_request = sync_request,
6778 .resize = raid5_resize,
6780 .check_reshape = raid5_check_reshape,
6781 .start_reshape = raid5_start_reshape,
6782 .finish_reshape = raid5_finish_reshape,
6783 .quiesce = raid5_quiesce,
6784 .takeover = raid5_takeover,
6787 static struct md_personality raid4_personality =
6791 .owner = THIS_MODULE,
6792 .make_request = make_request,
6796 .error_handler = error,
6797 .hot_add_disk = raid5_add_disk,
6798 .hot_remove_disk= raid5_remove_disk,
6799 .spare_active = raid5_spare_active,
6800 .sync_request = sync_request,
6801 .resize = raid5_resize,
6803 .check_reshape = raid5_check_reshape,
6804 .start_reshape = raid5_start_reshape,
6805 .finish_reshape = raid5_finish_reshape,
6806 .quiesce = raid5_quiesce,
6807 .takeover = raid4_takeover,
6810 static int __init raid5_init(void)
6812 raid5_wq = alloc_workqueue("raid5wq",
6813 WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
6816 register_md_personality(&raid6_personality);
6817 register_md_personality(&raid5_personality);
6818 register_md_personality(&raid4_personality);
6822 static void raid5_exit(void)
6824 unregister_md_personality(&raid6_personality);
6825 unregister_md_personality(&raid5_personality);
6826 unregister_md_personality(&raid4_personality);
6827 destroy_workqueue(raid5_wq);
6830 module_init(raid5_init);
6831 module_exit(raid5_exit);
6832 MODULE_LICENSE("GPL");
6833 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6834 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6835 MODULE_ALIAS("md-raid5");
6836 MODULE_ALIAS("md-raid4");
6837 MODULE_ALIAS("md-level-5");
6838 MODULE_ALIAS("md-level-4");
6839 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6840 MODULE_ALIAS("md-raid6");
6841 MODULE_ALIAS("md-level-6");
6843 /* This used to be two separate modules, they were: */
6844 MODULE_ALIAS("raid5");
6845 MODULE_ALIAS("raid6");