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->bm_write is the number of the last batch successfully written.
31 * conf->bm_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 bm_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/async.h>
51 #include <linux/seq_file.h>
52 #include <linux/cpu.h>
53 #include <linux/slab.h>
63 #define NR_STRIPES 256
64 #define STRIPE_SIZE PAGE_SIZE
65 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
66 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
67 #define IO_THRESHOLD 1
68 #define BYPASS_THRESHOLD 1
69 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
70 #define HASH_MASK (NR_HASH - 1)
72 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
74 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
75 * order without overlap. There may be several bio's per stripe+device, and
76 * a bio could span several devices.
77 * When walking this list for a particular stripe+device, we must never proceed
78 * beyond a bio that extends past this device, as the next bio might no longer
80 * This macro is used to determine the 'next' bio in the list, given the sector
81 * of the current stripe+device
83 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
85 * The following can be used to debug the driver
87 #define RAID5_PARANOIA 1
88 #if RAID5_PARANOIA && defined(CONFIG_SMP)
89 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
91 # define CHECK_DEVLOCK()
99 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
102 * We maintain a biased count of active stripes in the bottom 16 bits of
103 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
105 static inline int raid5_bi_phys_segments(struct bio *bio)
107 return bio->bi_phys_segments & 0xffff;
110 static inline int raid5_bi_hw_segments(struct bio *bio)
112 return (bio->bi_phys_segments >> 16) & 0xffff;
115 static inline int raid5_dec_bi_phys_segments(struct bio *bio)
117 --bio->bi_phys_segments;
118 return raid5_bi_phys_segments(bio);
121 static inline int raid5_dec_bi_hw_segments(struct bio *bio)
123 unsigned short val = raid5_bi_hw_segments(bio);
126 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
130 static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
132 bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
135 /* Find first data disk in a raid6 stripe */
136 static inline int raid6_d0(struct stripe_head *sh)
139 /* ddf always start from first device */
141 /* md starts just after Q block */
142 if (sh->qd_idx == sh->disks - 1)
145 return sh->qd_idx + 1;
147 static inline int raid6_next_disk(int disk, int raid_disks)
150 return (disk < raid_disks) ? disk : 0;
153 /* When walking through the disks in a raid5, starting at raid6_d0,
154 * We need to map each disk to a 'slot', where the data disks are slot
155 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
156 * is raid_disks-1. This help does that mapping.
158 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
159 int *count, int syndrome_disks)
165 if (idx == sh->pd_idx)
166 return syndrome_disks;
167 if (idx == sh->qd_idx)
168 return syndrome_disks + 1;
174 static void return_io(struct bio *return_bi)
176 struct bio *bi = return_bi;
179 return_bi = bi->bi_next;
187 static void print_raid5_conf (raid5_conf_t *conf);
189 static int stripe_operations_active(struct stripe_head *sh)
191 return sh->check_state || sh->reconstruct_state ||
192 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
193 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
196 static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
198 if (atomic_dec_and_test(&sh->count)) {
199 BUG_ON(!list_empty(&sh->lru));
200 BUG_ON(atomic_read(&conf->active_stripes)==0);
201 if (test_bit(STRIPE_HANDLE, &sh->state)) {
202 if (test_bit(STRIPE_DELAYED, &sh->state)) {
203 list_add_tail(&sh->lru, &conf->delayed_list);
204 plugger_set_plug(&conf->plug);
205 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
206 sh->bm_seq - conf->seq_write > 0) {
207 list_add_tail(&sh->lru, &conf->bitmap_list);
208 plugger_set_plug(&conf->plug);
210 clear_bit(STRIPE_BIT_DELAY, &sh->state);
211 list_add_tail(&sh->lru, &conf->handle_list);
213 md_wakeup_thread(conf->mddev->thread);
215 BUG_ON(stripe_operations_active(sh));
216 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
217 atomic_dec(&conf->preread_active_stripes);
218 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
219 md_wakeup_thread(conf->mddev->thread);
221 atomic_dec(&conf->active_stripes);
222 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
223 list_add_tail(&sh->lru, &conf->inactive_list);
224 wake_up(&conf->wait_for_stripe);
225 if (conf->retry_read_aligned)
226 md_wakeup_thread(conf->mddev->thread);
232 static void release_stripe(struct stripe_head *sh)
234 raid5_conf_t *conf = sh->raid_conf;
237 spin_lock_irqsave(&conf->device_lock, flags);
238 __release_stripe(conf, sh);
239 spin_unlock_irqrestore(&conf->device_lock, flags);
242 static inline void remove_hash(struct stripe_head *sh)
244 pr_debug("remove_hash(), stripe %llu\n",
245 (unsigned long long)sh->sector);
247 hlist_del_init(&sh->hash);
250 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
252 struct hlist_head *hp = stripe_hash(conf, sh->sector);
254 pr_debug("insert_hash(), stripe %llu\n",
255 (unsigned long long)sh->sector);
258 hlist_add_head(&sh->hash, hp);
262 /* find an idle stripe, make sure it is unhashed, and return it. */
263 static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
265 struct stripe_head *sh = NULL;
266 struct list_head *first;
269 if (list_empty(&conf->inactive_list))
271 first = conf->inactive_list.next;
272 sh = list_entry(first, struct stripe_head, lru);
273 list_del_init(first);
275 atomic_inc(&conf->active_stripes);
280 static void shrink_buffers(struct stripe_head *sh)
284 int num = sh->raid_conf->pool_size;
286 for (i = 0; i < num ; i++) {
290 sh->dev[i].page = NULL;
295 static int grow_buffers(struct stripe_head *sh)
298 int num = sh->raid_conf->pool_size;
300 for (i = 0; i < num; i++) {
303 if (!(page = alloc_page(GFP_KERNEL))) {
306 sh->dev[i].page = page;
311 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
312 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
313 struct stripe_head *sh);
315 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
317 raid5_conf_t *conf = sh->raid_conf;
320 BUG_ON(atomic_read(&sh->count) != 0);
321 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
322 BUG_ON(stripe_operations_active(sh));
325 pr_debug("init_stripe called, stripe %llu\n",
326 (unsigned long long)sh->sector);
330 sh->generation = conf->generation - previous;
331 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
333 stripe_set_idx(sector, conf, previous, sh);
337 for (i = sh->disks; i--; ) {
338 struct r5dev *dev = &sh->dev[i];
340 if (dev->toread || dev->read || dev->towrite || dev->written ||
341 test_bit(R5_LOCKED, &dev->flags)) {
342 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
343 (unsigned long long)sh->sector, i, dev->toread,
344 dev->read, dev->towrite, dev->written,
345 test_bit(R5_LOCKED, &dev->flags));
349 raid5_build_block(sh, i, previous);
351 insert_hash(conf, sh);
354 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
357 struct stripe_head *sh;
358 struct hlist_node *hn;
361 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
362 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
363 if (sh->sector == sector && sh->generation == generation)
365 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
370 * Need to check if array has failed when deciding whether to:
372 * - remove non-faulty devices
375 * This determination is simple when no reshape is happening.
376 * However if there is a reshape, we need to carefully check
377 * both the before and after sections.
378 * This is because some failed devices may only affect one
379 * of the two sections, and some non-in_sync devices may
380 * be insync in the section most affected by failed devices.
382 static int has_failed(raid5_conf_t *conf)
386 if (conf->mddev->reshape_position == MaxSector)
387 return conf->mddev->degraded > conf->max_degraded;
391 for (i = 0; i < conf->previous_raid_disks; i++) {
392 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
393 if (!rdev || test_bit(Faulty, &rdev->flags))
395 else if (test_bit(In_sync, &rdev->flags))
398 /* not in-sync or faulty.
399 * If the reshape increases the number of devices,
400 * this is being recovered by the reshape, so
401 * this 'previous' section is not in_sync.
402 * If the number of devices is being reduced however,
403 * the device can only be part of the array if
404 * we are reverting a reshape, so this section will
407 if (conf->raid_disks >= conf->previous_raid_disks)
411 if (degraded > conf->max_degraded)
415 for (i = 0; i < conf->raid_disks; i++) {
416 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
417 if (!rdev || test_bit(Faulty, &rdev->flags))
419 else if (test_bit(In_sync, &rdev->flags))
422 /* not in-sync or faulty.
423 * If reshape increases the number of devices, this
424 * section has already been recovered, else it
425 * almost certainly hasn't.
427 if (conf->raid_disks <= conf->previous_raid_disks)
431 if (degraded > conf->max_degraded)
436 static void unplug_slaves(mddev_t *mddev);
438 static struct stripe_head *
439 get_active_stripe(raid5_conf_t *conf, sector_t sector,
440 int previous, int noblock, int noquiesce)
442 struct stripe_head *sh;
444 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
446 spin_lock_irq(&conf->device_lock);
449 wait_event_lock_irq(conf->wait_for_stripe,
450 conf->quiesce == 0 || noquiesce,
451 conf->device_lock, /* nothing */);
452 sh = __find_stripe(conf, sector, conf->generation - previous);
454 if (!conf->inactive_blocked)
455 sh = get_free_stripe(conf);
456 if (noblock && sh == NULL)
459 conf->inactive_blocked = 1;
460 wait_event_lock_irq(conf->wait_for_stripe,
461 !list_empty(&conf->inactive_list) &&
462 (atomic_read(&conf->active_stripes)
463 < (conf->max_nr_stripes *3/4)
464 || !conf->inactive_blocked),
466 md_raid5_unplug_device(conf)
468 conf->inactive_blocked = 0;
470 init_stripe(sh, sector, previous);
472 if (atomic_read(&sh->count)) {
473 BUG_ON(!list_empty(&sh->lru)
474 && !test_bit(STRIPE_EXPANDING, &sh->state));
476 if (!test_bit(STRIPE_HANDLE, &sh->state))
477 atomic_inc(&conf->active_stripes);
478 if (list_empty(&sh->lru) &&
479 !test_bit(STRIPE_EXPANDING, &sh->state))
481 list_del_init(&sh->lru);
484 } while (sh == NULL);
487 atomic_inc(&sh->count);
489 spin_unlock_irq(&conf->device_lock);
494 raid5_end_read_request(struct bio *bi, int error);
496 raid5_end_write_request(struct bio *bi, int error);
498 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
500 raid5_conf_t *conf = sh->raid_conf;
501 int i, disks = sh->disks;
505 for (i = disks; i--; ) {
509 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
511 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
516 bi = &sh->dev[i].req;
520 bi->bi_end_io = raid5_end_write_request;
522 bi->bi_end_io = raid5_end_read_request;
525 rdev = rcu_dereference(conf->disks[i].rdev);
526 if (rdev && test_bit(Faulty, &rdev->flags))
529 atomic_inc(&rdev->nr_pending);
533 if (s->syncing || s->expanding || s->expanded)
534 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
536 set_bit(STRIPE_IO_STARTED, &sh->state);
538 bi->bi_bdev = rdev->bdev;
539 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
540 __func__, (unsigned long long)sh->sector,
542 atomic_inc(&sh->count);
543 bi->bi_sector = sh->sector + rdev->data_offset;
544 bi->bi_flags = 1 << BIO_UPTODATE;
548 bi->bi_io_vec = &sh->dev[i].vec;
549 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
550 bi->bi_io_vec[0].bv_offset = 0;
551 bi->bi_size = STRIPE_SIZE;
554 test_bit(R5_ReWrite, &sh->dev[i].flags))
555 atomic_add(STRIPE_SECTORS,
556 &rdev->corrected_errors);
557 generic_make_request(bi);
560 set_bit(STRIPE_DEGRADED, &sh->state);
561 pr_debug("skip op %ld on disc %d for sector %llu\n",
562 bi->bi_rw, i, (unsigned long long)sh->sector);
563 clear_bit(R5_LOCKED, &sh->dev[i].flags);
564 set_bit(STRIPE_HANDLE, &sh->state);
569 static struct dma_async_tx_descriptor *
570 async_copy_data(int frombio, struct bio *bio, struct page *page,
571 sector_t sector, struct dma_async_tx_descriptor *tx)
574 struct page *bio_page;
577 struct async_submit_ctl submit;
578 enum async_tx_flags flags = 0;
580 if (bio->bi_sector >= sector)
581 page_offset = (signed)(bio->bi_sector - sector) * 512;
583 page_offset = (signed)(sector - bio->bi_sector) * -512;
586 flags |= ASYNC_TX_FENCE;
587 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
589 bio_for_each_segment(bvl, bio, i) {
590 int len = bio_iovec_idx(bio, i)->bv_len;
594 if (page_offset < 0) {
595 b_offset = -page_offset;
596 page_offset += b_offset;
600 if (len > 0 && page_offset + len > STRIPE_SIZE)
601 clen = STRIPE_SIZE - page_offset;
606 b_offset += bio_iovec_idx(bio, i)->bv_offset;
607 bio_page = bio_iovec_idx(bio, i)->bv_page;
609 tx = async_memcpy(page, bio_page, page_offset,
610 b_offset, clen, &submit);
612 tx = async_memcpy(bio_page, page, b_offset,
613 page_offset, clen, &submit);
615 /* chain the operations */
616 submit.depend_tx = tx;
618 if (clen < len) /* hit end of page */
626 static void ops_complete_biofill(void *stripe_head_ref)
628 struct stripe_head *sh = stripe_head_ref;
629 struct bio *return_bi = NULL;
630 raid5_conf_t *conf = sh->raid_conf;
633 pr_debug("%s: stripe %llu\n", __func__,
634 (unsigned long long)sh->sector);
636 /* clear completed biofills */
637 spin_lock_irq(&conf->device_lock);
638 for (i = sh->disks; i--; ) {
639 struct r5dev *dev = &sh->dev[i];
641 /* acknowledge completion of a biofill operation */
642 /* and check if we need to reply to a read request,
643 * new R5_Wantfill requests are held off until
644 * !STRIPE_BIOFILL_RUN
646 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
647 struct bio *rbi, *rbi2;
652 while (rbi && rbi->bi_sector <
653 dev->sector + STRIPE_SECTORS) {
654 rbi2 = r5_next_bio(rbi, dev->sector);
655 if (!raid5_dec_bi_phys_segments(rbi)) {
656 rbi->bi_next = return_bi;
663 spin_unlock_irq(&conf->device_lock);
664 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
666 return_io(return_bi);
668 set_bit(STRIPE_HANDLE, &sh->state);
672 static void ops_run_biofill(struct stripe_head *sh)
674 struct dma_async_tx_descriptor *tx = NULL;
675 raid5_conf_t *conf = sh->raid_conf;
676 struct async_submit_ctl submit;
679 pr_debug("%s: stripe %llu\n", __func__,
680 (unsigned long long)sh->sector);
682 for (i = sh->disks; i--; ) {
683 struct r5dev *dev = &sh->dev[i];
684 if (test_bit(R5_Wantfill, &dev->flags)) {
686 spin_lock_irq(&conf->device_lock);
687 dev->read = rbi = dev->toread;
689 spin_unlock_irq(&conf->device_lock);
690 while (rbi && rbi->bi_sector <
691 dev->sector + STRIPE_SECTORS) {
692 tx = async_copy_data(0, rbi, dev->page,
694 rbi = r5_next_bio(rbi, dev->sector);
699 atomic_inc(&sh->count);
700 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
701 async_trigger_callback(&submit);
704 static void mark_target_uptodate(struct stripe_head *sh, int target)
711 tgt = &sh->dev[target];
712 set_bit(R5_UPTODATE, &tgt->flags);
713 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
714 clear_bit(R5_Wantcompute, &tgt->flags);
717 static void ops_complete_compute(void *stripe_head_ref)
719 struct stripe_head *sh = stripe_head_ref;
721 pr_debug("%s: stripe %llu\n", __func__,
722 (unsigned long long)sh->sector);
724 /* mark the computed target(s) as uptodate */
725 mark_target_uptodate(sh, sh->ops.target);
726 mark_target_uptodate(sh, sh->ops.target2);
728 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
729 if (sh->check_state == check_state_compute_run)
730 sh->check_state = check_state_compute_result;
731 set_bit(STRIPE_HANDLE, &sh->state);
735 /* return a pointer to the address conversion region of the scribble buffer */
736 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
737 struct raid5_percpu *percpu)
739 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
742 static struct dma_async_tx_descriptor *
743 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
745 int disks = sh->disks;
746 struct page **xor_srcs = percpu->scribble;
747 int target = sh->ops.target;
748 struct r5dev *tgt = &sh->dev[target];
749 struct page *xor_dest = tgt->page;
751 struct dma_async_tx_descriptor *tx;
752 struct async_submit_ctl submit;
755 pr_debug("%s: stripe %llu block: %d\n",
756 __func__, (unsigned long long)sh->sector, target);
757 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
759 for (i = disks; i--; )
761 xor_srcs[count++] = sh->dev[i].page;
763 atomic_inc(&sh->count);
765 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
766 ops_complete_compute, sh, to_addr_conv(sh, percpu));
767 if (unlikely(count == 1))
768 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
770 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
775 /* set_syndrome_sources - populate source buffers for gen_syndrome
776 * @srcs - (struct page *) array of size sh->disks
777 * @sh - stripe_head to parse
779 * Populates srcs in proper layout order for the stripe and returns the
780 * 'count' of sources to be used in a call to async_gen_syndrome. The P
781 * destination buffer is recorded in srcs[count] and the Q destination
782 * is recorded in srcs[count+1]].
784 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
786 int disks = sh->disks;
787 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
788 int d0_idx = raid6_d0(sh);
792 for (i = 0; i < disks; i++)
798 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
800 srcs[slot] = sh->dev[i].page;
801 i = raid6_next_disk(i, disks);
802 } while (i != d0_idx);
804 return syndrome_disks;
807 static struct dma_async_tx_descriptor *
808 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
810 int disks = sh->disks;
811 struct page **blocks = percpu->scribble;
813 int qd_idx = sh->qd_idx;
814 struct dma_async_tx_descriptor *tx;
815 struct async_submit_ctl submit;
821 if (sh->ops.target < 0)
822 target = sh->ops.target2;
823 else if (sh->ops.target2 < 0)
824 target = sh->ops.target;
826 /* we should only have one valid target */
829 pr_debug("%s: stripe %llu block: %d\n",
830 __func__, (unsigned long long)sh->sector, target);
832 tgt = &sh->dev[target];
833 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
836 atomic_inc(&sh->count);
838 if (target == qd_idx) {
839 count = set_syndrome_sources(blocks, sh);
840 blocks[count] = NULL; /* regenerating p is not necessary */
841 BUG_ON(blocks[count+1] != dest); /* q should already be set */
842 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
843 ops_complete_compute, sh,
844 to_addr_conv(sh, percpu));
845 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
847 /* Compute any data- or p-drive using XOR */
849 for (i = disks; i-- ; ) {
850 if (i == target || i == qd_idx)
852 blocks[count++] = sh->dev[i].page;
855 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
856 NULL, ops_complete_compute, sh,
857 to_addr_conv(sh, percpu));
858 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
864 static struct dma_async_tx_descriptor *
865 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
867 int i, count, disks = sh->disks;
868 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
869 int d0_idx = raid6_d0(sh);
870 int faila = -1, failb = -1;
871 int target = sh->ops.target;
872 int target2 = sh->ops.target2;
873 struct r5dev *tgt = &sh->dev[target];
874 struct r5dev *tgt2 = &sh->dev[target2];
875 struct dma_async_tx_descriptor *tx;
876 struct page **blocks = percpu->scribble;
877 struct async_submit_ctl submit;
879 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
880 __func__, (unsigned long long)sh->sector, target, target2);
881 BUG_ON(target < 0 || target2 < 0);
882 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
883 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
885 /* we need to open-code set_syndrome_sources to handle the
886 * slot number conversion for 'faila' and 'failb'
888 for (i = 0; i < disks ; i++)
893 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
895 blocks[slot] = sh->dev[i].page;
901 i = raid6_next_disk(i, disks);
902 } while (i != d0_idx);
904 BUG_ON(faila == failb);
907 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
908 __func__, (unsigned long long)sh->sector, faila, failb);
910 atomic_inc(&sh->count);
912 if (failb == syndrome_disks+1) {
913 /* Q disk is one of the missing disks */
914 if (faila == syndrome_disks) {
915 /* Missing P+Q, just recompute */
916 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
917 ops_complete_compute, sh,
918 to_addr_conv(sh, percpu));
919 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
920 STRIPE_SIZE, &submit);
924 int qd_idx = sh->qd_idx;
926 /* Missing D+Q: recompute D from P, then recompute Q */
927 if (target == qd_idx)
928 data_target = target2;
930 data_target = target;
933 for (i = disks; i-- ; ) {
934 if (i == data_target || i == qd_idx)
936 blocks[count++] = sh->dev[i].page;
938 dest = sh->dev[data_target].page;
939 init_async_submit(&submit,
940 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
942 to_addr_conv(sh, percpu));
943 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
946 count = set_syndrome_sources(blocks, sh);
947 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
948 ops_complete_compute, sh,
949 to_addr_conv(sh, percpu));
950 return async_gen_syndrome(blocks, 0, count+2,
951 STRIPE_SIZE, &submit);
954 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
955 ops_complete_compute, sh,
956 to_addr_conv(sh, percpu));
957 if (failb == syndrome_disks) {
958 /* We're missing D+P. */
959 return async_raid6_datap_recov(syndrome_disks+2,
963 /* We're missing D+D. */
964 return async_raid6_2data_recov(syndrome_disks+2,
965 STRIPE_SIZE, faila, failb,
972 static void ops_complete_prexor(void *stripe_head_ref)
974 struct stripe_head *sh = stripe_head_ref;
976 pr_debug("%s: stripe %llu\n", __func__,
977 (unsigned long long)sh->sector);
980 static struct dma_async_tx_descriptor *
981 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
982 struct dma_async_tx_descriptor *tx)
984 int disks = sh->disks;
985 struct page **xor_srcs = percpu->scribble;
986 int count = 0, pd_idx = sh->pd_idx, i;
987 struct async_submit_ctl submit;
989 /* existing parity data subtracted */
990 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
992 pr_debug("%s: stripe %llu\n", __func__,
993 (unsigned long long)sh->sector);
995 for (i = disks; i--; ) {
996 struct r5dev *dev = &sh->dev[i];
997 /* Only process blocks that are known to be uptodate */
998 if (test_bit(R5_Wantdrain, &dev->flags))
999 xor_srcs[count++] = dev->page;
1002 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1003 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
1004 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1009 static struct dma_async_tx_descriptor *
1010 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1012 int disks = sh->disks;
1015 pr_debug("%s: stripe %llu\n", __func__,
1016 (unsigned long long)sh->sector);
1018 for (i = disks; i--; ) {
1019 struct r5dev *dev = &sh->dev[i];
1022 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
1025 spin_lock(&sh->lock);
1026 chosen = dev->towrite;
1027 dev->towrite = NULL;
1028 BUG_ON(dev->written);
1029 wbi = dev->written = chosen;
1030 spin_unlock(&sh->lock);
1032 while (wbi && wbi->bi_sector <
1033 dev->sector + STRIPE_SECTORS) {
1034 tx = async_copy_data(1, wbi, dev->page,
1036 wbi = r5_next_bio(wbi, dev->sector);
1044 static void ops_complete_reconstruct(void *stripe_head_ref)
1046 struct stripe_head *sh = stripe_head_ref;
1047 int disks = sh->disks;
1048 int pd_idx = sh->pd_idx;
1049 int qd_idx = sh->qd_idx;
1052 pr_debug("%s: stripe %llu\n", __func__,
1053 (unsigned long long)sh->sector);
1055 for (i = disks; i--; ) {
1056 struct r5dev *dev = &sh->dev[i];
1058 if (dev->written || i == pd_idx || i == qd_idx)
1059 set_bit(R5_UPTODATE, &dev->flags);
1062 if (sh->reconstruct_state == reconstruct_state_drain_run)
1063 sh->reconstruct_state = reconstruct_state_drain_result;
1064 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1065 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1067 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1068 sh->reconstruct_state = reconstruct_state_result;
1071 set_bit(STRIPE_HANDLE, &sh->state);
1076 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1077 struct dma_async_tx_descriptor *tx)
1079 int disks = sh->disks;
1080 struct page **xor_srcs = percpu->scribble;
1081 struct async_submit_ctl submit;
1082 int count = 0, pd_idx = sh->pd_idx, i;
1083 struct page *xor_dest;
1085 unsigned long flags;
1087 pr_debug("%s: stripe %llu\n", __func__,
1088 (unsigned long long)sh->sector);
1090 /* check if prexor is active which means only process blocks
1091 * that are part of a read-modify-write (written)
1093 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1095 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1096 for (i = disks; i--; ) {
1097 struct r5dev *dev = &sh->dev[i];
1099 xor_srcs[count++] = dev->page;
1102 xor_dest = sh->dev[pd_idx].page;
1103 for (i = disks; i--; ) {
1104 struct r5dev *dev = &sh->dev[i];
1106 xor_srcs[count++] = dev->page;
1110 /* 1/ if we prexor'd then the dest is reused as a source
1111 * 2/ if we did not prexor then we are redoing the parity
1112 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1113 * for the synchronous xor case
1115 flags = ASYNC_TX_ACK |
1116 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1118 atomic_inc(&sh->count);
1120 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
1121 to_addr_conv(sh, percpu));
1122 if (unlikely(count == 1))
1123 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1125 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1129 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1130 struct dma_async_tx_descriptor *tx)
1132 struct async_submit_ctl submit;
1133 struct page **blocks = percpu->scribble;
1136 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1138 count = set_syndrome_sources(blocks, sh);
1140 atomic_inc(&sh->count);
1142 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1143 sh, to_addr_conv(sh, percpu));
1144 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1147 static void ops_complete_check(void *stripe_head_ref)
1149 struct stripe_head *sh = stripe_head_ref;
1151 pr_debug("%s: stripe %llu\n", __func__,
1152 (unsigned long long)sh->sector);
1154 sh->check_state = check_state_check_result;
1155 set_bit(STRIPE_HANDLE, &sh->state);
1159 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1161 int disks = sh->disks;
1162 int pd_idx = sh->pd_idx;
1163 int qd_idx = sh->qd_idx;
1164 struct page *xor_dest;
1165 struct page **xor_srcs = percpu->scribble;
1166 struct dma_async_tx_descriptor *tx;
1167 struct async_submit_ctl submit;
1171 pr_debug("%s: stripe %llu\n", __func__,
1172 (unsigned long long)sh->sector);
1175 xor_dest = sh->dev[pd_idx].page;
1176 xor_srcs[count++] = xor_dest;
1177 for (i = disks; i--; ) {
1178 if (i == pd_idx || i == qd_idx)
1180 xor_srcs[count++] = sh->dev[i].page;
1183 init_async_submit(&submit, 0, NULL, NULL, NULL,
1184 to_addr_conv(sh, percpu));
1185 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1186 &sh->ops.zero_sum_result, &submit);
1188 atomic_inc(&sh->count);
1189 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1190 tx = async_trigger_callback(&submit);
1193 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1195 struct page **srcs = percpu->scribble;
1196 struct async_submit_ctl submit;
1199 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1200 (unsigned long long)sh->sector, checkp);
1202 count = set_syndrome_sources(srcs, sh);
1206 atomic_inc(&sh->count);
1207 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1208 sh, to_addr_conv(sh, percpu));
1209 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1210 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1213 static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1215 int overlap_clear = 0, i, disks = sh->disks;
1216 struct dma_async_tx_descriptor *tx = NULL;
1217 raid5_conf_t *conf = sh->raid_conf;
1218 int level = conf->level;
1219 struct raid5_percpu *percpu;
1223 percpu = per_cpu_ptr(conf->percpu, cpu);
1224 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1225 ops_run_biofill(sh);
1229 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1231 tx = ops_run_compute5(sh, percpu);
1233 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1234 tx = ops_run_compute6_1(sh, percpu);
1236 tx = ops_run_compute6_2(sh, percpu);
1238 /* terminate the chain if reconstruct is not set to be run */
1239 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1243 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
1244 tx = ops_run_prexor(sh, percpu, tx);
1246 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1247 tx = ops_run_biodrain(sh, tx);
1251 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1253 ops_run_reconstruct5(sh, percpu, tx);
1255 ops_run_reconstruct6(sh, percpu, tx);
1258 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1259 if (sh->check_state == check_state_run)
1260 ops_run_check_p(sh, percpu);
1261 else if (sh->check_state == check_state_run_q)
1262 ops_run_check_pq(sh, percpu, 0);
1263 else if (sh->check_state == check_state_run_pq)
1264 ops_run_check_pq(sh, percpu, 1);
1270 for (i = disks; i--; ) {
1271 struct r5dev *dev = &sh->dev[i];
1272 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1273 wake_up(&sh->raid_conf->wait_for_overlap);
1278 #ifdef CONFIG_MULTICORE_RAID456
1279 static void async_run_ops(void *param, async_cookie_t cookie)
1281 struct stripe_head *sh = param;
1282 unsigned long ops_request = sh->ops.request;
1284 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
1285 wake_up(&sh->ops.wait_for_ops);
1287 __raid_run_ops(sh, ops_request);
1291 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1293 /* since handle_stripe can be called outside of raid5d context
1294 * we need to ensure sh->ops.request is de-staged before another
1297 wait_event(sh->ops.wait_for_ops,
1298 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
1299 sh->ops.request = ops_request;
1301 atomic_inc(&sh->count);
1302 async_schedule(async_run_ops, sh);
1305 #define raid_run_ops __raid_run_ops
1308 static int grow_one_stripe(raid5_conf_t *conf)
1310 struct stripe_head *sh;
1311 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
1314 memset(sh, 0, sizeof(*sh) + (conf->pool_size-1)*sizeof(struct r5dev));
1315 sh->raid_conf = conf;
1316 spin_lock_init(&sh->lock);
1317 #ifdef CONFIG_MULTICORE_RAID456
1318 init_waitqueue_head(&sh->ops.wait_for_ops);
1321 if (grow_buffers(sh)) {
1323 kmem_cache_free(conf->slab_cache, sh);
1326 /* we just created an active stripe so... */
1327 atomic_set(&sh->count, 1);
1328 atomic_inc(&conf->active_stripes);
1329 INIT_LIST_HEAD(&sh->lru);
1334 static int grow_stripes(raid5_conf_t *conf, int num)
1336 struct kmem_cache *sc;
1337 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1339 if (conf->mddev->gendisk)
1340 sprintf(conf->cache_name[0],
1341 "raid%d-%s", conf->level, mdname(conf->mddev));
1343 sprintf(conf->cache_name[0],
1344 "raid%d-%p", conf->level, conf->mddev);
1345 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1347 conf->active_name = 0;
1348 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1349 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
1353 conf->slab_cache = sc;
1354 conf->pool_size = devs;
1356 if (!grow_one_stripe(conf))
1362 * scribble_len - return the required size of the scribble region
1363 * @num - total number of disks in the array
1365 * The size must be enough to contain:
1366 * 1/ a struct page pointer for each device in the array +2
1367 * 2/ room to convert each entry in (1) to its corresponding dma
1368 * (dma_map_page()) or page (page_address()) address.
1370 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1371 * calculate over all devices (not just the data blocks), using zeros in place
1372 * of the P and Q blocks.
1374 static size_t scribble_len(int num)
1378 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1383 static int resize_stripes(raid5_conf_t *conf, int newsize)
1385 /* Make all the stripes able to hold 'newsize' devices.
1386 * New slots in each stripe get 'page' set to a new page.
1388 * This happens in stages:
1389 * 1/ create a new kmem_cache and allocate the required number of
1391 * 2/ gather all the old stripe_heads and tranfer the pages across
1392 * to the new stripe_heads. This will have the side effect of
1393 * freezing the array as once all stripe_heads have been collected,
1394 * no IO will be possible. Old stripe heads are freed once their
1395 * pages have been transferred over, and the old kmem_cache is
1396 * freed when all stripes are done.
1397 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1398 * we simple return a failre status - no need to clean anything up.
1399 * 4/ allocate new pages for the new slots in the new stripe_heads.
1400 * If this fails, we don't bother trying the shrink the
1401 * stripe_heads down again, we just leave them as they are.
1402 * As each stripe_head is processed the new one is released into
1405 * Once step2 is started, we cannot afford to wait for a write,
1406 * so we use GFP_NOIO allocations.
1408 struct stripe_head *osh, *nsh;
1409 LIST_HEAD(newstripes);
1410 struct disk_info *ndisks;
1413 struct kmem_cache *sc;
1416 if (newsize <= conf->pool_size)
1417 return 0; /* never bother to shrink */
1419 err = md_allow_write(conf->mddev);
1424 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1425 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
1430 for (i = conf->max_nr_stripes; i; i--) {
1431 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1435 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1437 nsh->raid_conf = conf;
1438 spin_lock_init(&nsh->lock);
1439 #ifdef CONFIG_MULTICORE_RAID456
1440 init_waitqueue_head(&nsh->ops.wait_for_ops);
1443 list_add(&nsh->lru, &newstripes);
1446 /* didn't get enough, give up */
1447 while (!list_empty(&newstripes)) {
1448 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1449 list_del(&nsh->lru);
1450 kmem_cache_free(sc, nsh);
1452 kmem_cache_destroy(sc);
1455 /* Step 2 - Must use GFP_NOIO now.
1456 * OK, we have enough stripes, start collecting inactive
1457 * stripes and copying them over
1459 list_for_each_entry(nsh, &newstripes, lru) {
1460 spin_lock_irq(&conf->device_lock);
1461 wait_event_lock_irq(conf->wait_for_stripe,
1462 !list_empty(&conf->inactive_list),
1464 unplug_slaves(conf->mddev)
1466 osh = get_free_stripe(conf);
1467 spin_unlock_irq(&conf->device_lock);
1468 atomic_set(&nsh->count, 1);
1469 for(i=0; i<conf->pool_size; i++)
1470 nsh->dev[i].page = osh->dev[i].page;
1471 for( ; i<newsize; i++)
1472 nsh->dev[i].page = NULL;
1473 kmem_cache_free(conf->slab_cache, osh);
1475 kmem_cache_destroy(conf->slab_cache);
1478 * At this point, we are holding all the stripes so the array
1479 * is completely stalled, so now is a good time to resize
1480 * conf->disks and the scribble region
1482 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1484 for (i=0; i<conf->raid_disks; i++)
1485 ndisks[i] = conf->disks[i];
1487 conf->disks = ndisks;
1492 conf->scribble_len = scribble_len(newsize);
1493 for_each_present_cpu(cpu) {
1494 struct raid5_percpu *percpu;
1497 percpu = per_cpu_ptr(conf->percpu, cpu);
1498 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1501 kfree(percpu->scribble);
1502 percpu->scribble = scribble;
1510 /* Step 4, return new stripes to service */
1511 while(!list_empty(&newstripes)) {
1512 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1513 list_del_init(&nsh->lru);
1515 for (i=conf->raid_disks; i < newsize; i++)
1516 if (nsh->dev[i].page == NULL) {
1517 struct page *p = alloc_page(GFP_NOIO);
1518 nsh->dev[i].page = p;
1522 release_stripe(nsh);
1524 /* critical section pass, GFP_NOIO no longer needed */
1526 conf->slab_cache = sc;
1527 conf->active_name = 1-conf->active_name;
1528 conf->pool_size = newsize;
1532 static int drop_one_stripe(raid5_conf_t *conf)
1534 struct stripe_head *sh;
1536 spin_lock_irq(&conf->device_lock);
1537 sh = get_free_stripe(conf);
1538 spin_unlock_irq(&conf->device_lock);
1541 BUG_ON(atomic_read(&sh->count));
1543 kmem_cache_free(conf->slab_cache, sh);
1544 atomic_dec(&conf->active_stripes);
1548 static void shrink_stripes(raid5_conf_t *conf)
1550 while (drop_one_stripe(conf))
1553 if (conf->slab_cache)
1554 kmem_cache_destroy(conf->slab_cache);
1555 conf->slab_cache = NULL;
1558 static void raid5_end_read_request(struct bio * bi, int error)
1560 struct stripe_head *sh = bi->bi_private;
1561 raid5_conf_t *conf = sh->raid_conf;
1562 int disks = sh->disks, i;
1563 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1564 char b[BDEVNAME_SIZE];
1568 for (i=0 ; i<disks; i++)
1569 if (bi == &sh->dev[i].req)
1572 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1573 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1581 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1582 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1583 rdev = conf->disks[i].rdev;
1584 printk_rl(KERN_INFO "md/raid:%s: read error corrected"
1585 " (%lu sectors at %llu on %s)\n",
1586 mdname(conf->mddev), STRIPE_SECTORS,
1587 (unsigned long long)(sh->sector
1588 + rdev->data_offset),
1589 bdevname(rdev->bdev, b));
1590 clear_bit(R5_ReadError, &sh->dev[i].flags);
1591 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1593 if (atomic_read(&conf->disks[i].rdev->read_errors))
1594 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1596 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
1598 rdev = conf->disks[i].rdev;
1600 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1601 atomic_inc(&rdev->read_errors);
1602 if (conf->mddev->degraded >= conf->max_degraded)
1603 printk_rl(KERN_WARNING
1604 "md/raid:%s: read error not correctable "
1605 "(sector %llu on %s).\n",
1606 mdname(conf->mddev),
1607 (unsigned long long)(sh->sector
1608 + rdev->data_offset),
1610 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
1612 printk_rl(KERN_WARNING
1613 "md/raid:%s: read error NOT corrected!! "
1614 "(sector %llu on %s).\n",
1615 mdname(conf->mddev),
1616 (unsigned long long)(sh->sector
1617 + rdev->data_offset),
1619 else if (atomic_read(&rdev->read_errors)
1620 > conf->max_nr_stripes)
1622 "md/raid:%s: Too many read errors, failing device %s.\n",
1623 mdname(conf->mddev), bdn);
1627 set_bit(R5_ReadError, &sh->dev[i].flags);
1629 clear_bit(R5_ReadError, &sh->dev[i].flags);
1630 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1631 md_error(conf->mddev, rdev);
1634 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1635 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1636 set_bit(STRIPE_HANDLE, &sh->state);
1640 static void raid5_end_write_request(struct bio *bi, int error)
1642 struct stripe_head *sh = bi->bi_private;
1643 raid5_conf_t *conf = sh->raid_conf;
1644 int disks = sh->disks, i;
1645 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1647 for (i=0 ; i<disks; i++)
1648 if (bi == &sh->dev[i].req)
1651 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1652 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1660 md_error(conf->mddev, conf->disks[i].rdev);
1662 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1664 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1665 set_bit(STRIPE_HANDLE, &sh->state);
1670 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1672 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1674 struct r5dev *dev = &sh->dev[i];
1676 bio_init(&dev->req);
1677 dev->req.bi_io_vec = &dev->vec;
1679 dev->req.bi_max_vecs++;
1680 dev->vec.bv_page = dev->page;
1681 dev->vec.bv_len = STRIPE_SIZE;
1682 dev->vec.bv_offset = 0;
1684 dev->req.bi_sector = sh->sector;
1685 dev->req.bi_private = sh;
1688 dev->sector = compute_blocknr(sh, i, previous);
1691 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1693 char b[BDEVNAME_SIZE];
1694 raid5_conf_t *conf = mddev->private;
1695 pr_debug("raid456: error called\n");
1697 if (!test_bit(Faulty, &rdev->flags)) {
1698 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1699 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1700 unsigned long flags;
1701 spin_lock_irqsave(&conf->device_lock, flags);
1703 spin_unlock_irqrestore(&conf->device_lock, flags);
1705 * if recovery was running, make sure it aborts.
1707 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1709 set_bit(Faulty, &rdev->flags);
1711 "md/raid:%s: Disk failure on %s, disabling device.\n"
1713 "md/raid:%s: Operation continuing on %d devices.\n",
1715 bdevname(rdev->bdev, b),
1717 conf->raid_disks - mddev->degraded);
1722 * Input: a 'big' sector number,
1723 * Output: index of the data and parity disk, and the sector # in them.
1725 static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
1726 int previous, int *dd_idx,
1727 struct stripe_head *sh)
1729 sector_t stripe, stripe2;
1730 sector_t chunk_number;
1731 unsigned int chunk_offset;
1734 sector_t new_sector;
1735 int algorithm = previous ? conf->prev_algo
1737 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1738 : conf->chunk_sectors;
1739 int raid_disks = previous ? conf->previous_raid_disks
1741 int data_disks = raid_disks - conf->max_degraded;
1743 /* First compute the information on this sector */
1746 * Compute the chunk number and the sector offset inside the chunk
1748 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1749 chunk_number = r_sector;
1752 * Compute the stripe number
1754 stripe = chunk_number;
1755 *dd_idx = sector_div(stripe, data_disks);
1758 * Select the parity disk based on the user selected algorithm.
1760 pd_idx = qd_idx = ~0;
1761 switch(conf->level) {
1763 pd_idx = data_disks;
1766 switch (algorithm) {
1767 case ALGORITHM_LEFT_ASYMMETRIC:
1768 pd_idx = data_disks - sector_div(stripe2, raid_disks);
1769 if (*dd_idx >= pd_idx)
1772 case ALGORITHM_RIGHT_ASYMMETRIC:
1773 pd_idx = sector_div(stripe2, raid_disks);
1774 if (*dd_idx >= pd_idx)
1777 case ALGORITHM_LEFT_SYMMETRIC:
1778 pd_idx = data_disks - sector_div(stripe2, raid_disks);
1779 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1781 case ALGORITHM_RIGHT_SYMMETRIC:
1782 pd_idx = sector_div(stripe2, raid_disks);
1783 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1785 case ALGORITHM_PARITY_0:
1789 case ALGORITHM_PARITY_N:
1790 pd_idx = data_disks;
1798 switch (algorithm) {
1799 case ALGORITHM_LEFT_ASYMMETRIC:
1800 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1801 qd_idx = pd_idx + 1;
1802 if (pd_idx == raid_disks-1) {
1803 (*dd_idx)++; /* Q D D D P */
1805 } else if (*dd_idx >= pd_idx)
1806 (*dd_idx) += 2; /* D D P Q D */
1808 case ALGORITHM_RIGHT_ASYMMETRIC:
1809 pd_idx = sector_div(stripe2, raid_disks);
1810 qd_idx = pd_idx + 1;
1811 if (pd_idx == raid_disks-1) {
1812 (*dd_idx)++; /* Q D D D P */
1814 } else if (*dd_idx >= pd_idx)
1815 (*dd_idx) += 2; /* D D P Q D */
1817 case ALGORITHM_LEFT_SYMMETRIC:
1818 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1819 qd_idx = (pd_idx + 1) % raid_disks;
1820 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1822 case ALGORITHM_RIGHT_SYMMETRIC:
1823 pd_idx = sector_div(stripe2, raid_disks);
1824 qd_idx = (pd_idx + 1) % raid_disks;
1825 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1828 case ALGORITHM_PARITY_0:
1833 case ALGORITHM_PARITY_N:
1834 pd_idx = data_disks;
1835 qd_idx = data_disks + 1;
1838 case ALGORITHM_ROTATING_ZERO_RESTART:
1839 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1840 * of blocks for computing Q is different.
1842 pd_idx = sector_div(stripe2, raid_disks);
1843 qd_idx = pd_idx + 1;
1844 if (pd_idx == raid_disks-1) {
1845 (*dd_idx)++; /* Q D D D P */
1847 } else if (*dd_idx >= pd_idx)
1848 (*dd_idx) += 2; /* D D P Q D */
1852 case ALGORITHM_ROTATING_N_RESTART:
1853 /* Same a left_asymmetric, by first stripe is
1854 * D D D P Q rather than
1858 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1859 qd_idx = pd_idx + 1;
1860 if (pd_idx == raid_disks-1) {
1861 (*dd_idx)++; /* Q D D D P */
1863 } else if (*dd_idx >= pd_idx)
1864 (*dd_idx) += 2; /* D D P Q D */
1868 case ALGORITHM_ROTATING_N_CONTINUE:
1869 /* Same as left_symmetric but Q is before P */
1870 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1871 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1872 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1876 case ALGORITHM_LEFT_ASYMMETRIC_6:
1877 /* RAID5 left_asymmetric, with Q on last device */
1878 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
1879 if (*dd_idx >= pd_idx)
1881 qd_idx = raid_disks - 1;
1884 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1885 pd_idx = sector_div(stripe2, raid_disks-1);
1886 if (*dd_idx >= pd_idx)
1888 qd_idx = raid_disks - 1;
1891 case ALGORITHM_LEFT_SYMMETRIC_6:
1892 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
1893 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1894 qd_idx = raid_disks - 1;
1897 case ALGORITHM_RIGHT_SYMMETRIC_6:
1898 pd_idx = sector_div(stripe2, raid_disks-1);
1899 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1900 qd_idx = raid_disks - 1;
1903 case ALGORITHM_PARITY_0_6:
1906 qd_idx = raid_disks - 1;
1916 sh->pd_idx = pd_idx;
1917 sh->qd_idx = qd_idx;
1918 sh->ddf_layout = ddf_layout;
1921 * Finally, compute the new sector number
1923 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1928 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
1930 raid5_conf_t *conf = sh->raid_conf;
1931 int raid_disks = sh->disks;
1932 int data_disks = raid_disks - conf->max_degraded;
1933 sector_t new_sector = sh->sector, check;
1934 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1935 : conf->chunk_sectors;
1936 int algorithm = previous ? conf->prev_algo
1940 sector_t chunk_number;
1941 int dummy1, dd_idx = i;
1943 struct stripe_head sh2;
1946 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1947 stripe = new_sector;
1949 if (i == sh->pd_idx)
1951 switch(conf->level) {
1954 switch (algorithm) {
1955 case ALGORITHM_LEFT_ASYMMETRIC:
1956 case ALGORITHM_RIGHT_ASYMMETRIC:
1960 case ALGORITHM_LEFT_SYMMETRIC:
1961 case ALGORITHM_RIGHT_SYMMETRIC:
1964 i -= (sh->pd_idx + 1);
1966 case ALGORITHM_PARITY_0:
1969 case ALGORITHM_PARITY_N:
1976 if (i == sh->qd_idx)
1977 return 0; /* It is the Q disk */
1978 switch (algorithm) {
1979 case ALGORITHM_LEFT_ASYMMETRIC:
1980 case ALGORITHM_RIGHT_ASYMMETRIC:
1981 case ALGORITHM_ROTATING_ZERO_RESTART:
1982 case ALGORITHM_ROTATING_N_RESTART:
1983 if (sh->pd_idx == raid_disks-1)
1984 i--; /* Q D D D P */
1985 else if (i > sh->pd_idx)
1986 i -= 2; /* D D P Q D */
1988 case ALGORITHM_LEFT_SYMMETRIC:
1989 case ALGORITHM_RIGHT_SYMMETRIC:
1990 if (sh->pd_idx == raid_disks-1)
1991 i--; /* Q D D D P */
1996 i -= (sh->pd_idx + 2);
1999 case ALGORITHM_PARITY_0:
2002 case ALGORITHM_PARITY_N:
2004 case ALGORITHM_ROTATING_N_CONTINUE:
2005 /* Like left_symmetric, but P is before Q */
2006 if (sh->pd_idx == 0)
2007 i--; /* P D D D Q */
2012 i -= (sh->pd_idx + 1);
2015 case ALGORITHM_LEFT_ASYMMETRIC_6:
2016 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2020 case ALGORITHM_LEFT_SYMMETRIC_6:
2021 case ALGORITHM_RIGHT_SYMMETRIC_6:
2023 i += data_disks + 1;
2024 i -= (sh->pd_idx + 1);
2026 case ALGORITHM_PARITY_0_6:
2035 chunk_number = stripe * data_disks + i;
2036 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2038 check = raid5_compute_sector(conf, r_sector,
2039 previous, &dummy1, &sh2);
2040 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2041 || sh2.qd_idx != sh->qd_idx) {
2042 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2043 mdname(conf->mddev));
2051 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2052 int rcw, int expand)
2054 int i, pd_idx = sh->pd_idx, disks = sh->disks;
2055 raid5_conf_t *conf = sh->raid_conf;
2056 int level = conf->level;
2059 /* if we are not expanding this is a proper write request, and
2060 * there will be bios with new data to be drained into the
2064 sh->reconstruct_state = reconstruct_state_drain_run;
2065 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2067 sh->reconstruct_state = reconstruct_state_run;
2069 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2071 for (i = disks; i--; ) {
2072 struct r5dev *dev = &sh->dev[i];
2075 set_bit(R5_LOCKED, &dev->flags);
2076 set_bit(R5_Wantdrain, &dev->flags);
2078 clear_bit(R5_UPTODATE, &dev->flags);
2082 if (s->locked + conf->max_degraded == disks)
2083 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2084 atomic_inc(&conf->pending_full_writes);
2087 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2088 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2090 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2091 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2092 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2093 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2095 for (i = disks; i--; ) {
2096 struct r5dev *dev = &sh->dev[i];
2101 (test_bit(R5_UPTODATE, &dev->flags) ||
2102 test_bit(R5_Wantcompute, &dev->flags))) {
2103 set_bit(R5_Wantdrain, &dev->flags);
2104 set_bit(R5_LOCKED, &dev->flags);
2105 clear_bit(R5_UPTODATE, &dev->flags);
2111 /* keep the parity disk(s) locked while asynchronous operations
2114 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2115 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2119 int qd_idx = sh->qd_idx;
2120 struct r5dev *dev = &sh->dev[qd_idx];
2122 set_bit(R5_LOCKED, &dev->flags);
2123 clear_bit(R5_UPTODATE, &dev->flags);
2127 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2128 __func__, (unsigned long long)sh->sector,
2129 s->locked, s->ops_request);
2133 * Each stripe/dev can have one or more bion attached.
2134 * toread/towrite point to the first in a chain.
2135 * The bi_next chain must be in order.
2137 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2140 raid5_conf_t *conf = sh->raid_conf;
2143 pr_debug("adding bh b#%llu to stripe s#%llu\n",
2144 (unsigned long long)bi->bi_sector,
2145 (unsigned long long)sh->sector);
2148 spin_lock(&sh->lock);
2149 spin_lock_irq(&conf->device_lock);
2151 bip = &sh->dev[dd_idx].towrite;
2152 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
2155 bip = &sh->dev[dd_idx].toread;
2156 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2157 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
2159 bip = & (*bip)->bi_next;
2161 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
2164 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2168 bi->bi_phys_segments++;
2169 spin_unlock_irq(&conf->device_lock);
2170 spin_unlock(&sh->lock);
2172 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2173 (unsigned long long)bi->bi_sector,
2174 (unsigned long long)sh->sector, dd_idx);
2176 if (conf->mddev->bitmap && firstwrite) {
2177 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2179 sh->bm_seq = conf->seq_flush+1;
2180 set_bit(STRIPE_BIT_DELAY, &sh->state);
2184 /* check if page is covered */
2185 sector_t sector = sh->dev[dd_idx].sector;
2186 for (bi=sh->dev[dd_idx].towrite;
2187 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2188 bi && bi->bi_sector <= sector;
2189 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2190 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
2191 sector = bi->bi_sector + (bi->bi_size>>9);
2193 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2194 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2199 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2200 spin_unlock_irq(&conf->device_lock);
2201 spin_unlock(&sh->lock);
2205 static void end_reshape(raid5_conf_t *conf);
2207 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
2208 struct stripe_head *sh)
2210 int sectors_per_chunk =
2211 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
2213 int chunk_offset = sector_div(stripe, sectors_per_chunk);
2214 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2216 raid5_compute_sector(conf,
2217 stripe * (disks - conf->max_degraded)
2218 *sectors_per_chunk + chunk_offset,
2224 handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
2225 struct stripe_head_state *s, int disks,
2226 struct bio **return_bi)
2229 for (i = disks; i--; ) {
2233 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2236 rdev = rcu_dereference(conf->disks[i].rdev);
2237 if (rdev && test_bit(In_sync, &rdev->flags))
2238 /* multiple read failures in one stripe */
2239 md_error(conf->mddev, rdev);
2242 spin_lock_irq(&conf->device_lock);
2243 /* fail all writes first */
2244 bi = sh->dev[i].towrite;
2245 sh->dev[i].towrite = NULL;
2251 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2252 wake_up(&conf->wait_for_overlap);
2254 while (bi && bi->bi_sector <
2255 sh->dev[i].sector + STRIPE_SECTORS) {
2256 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2257 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2258 if (!raid5_dec_bi_phys_segments(bi)) {
2259 md_write_end(conf->mddev);
2260 bi->bi_next = *return_bi;
2265 /* and fail all 'written' */
2266 bi = sh->dev[i].written;
2267 sh->dev[i].written = NULL;
2268 if (bi) bitmap_end = 1;
2269 while (bi && bi->bi_sector <
2270 sh->dev[i].sector + STRIPE_SECTORS) {
2271 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2272 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2273 if (!raid5_dec_bi_phys_segments(bi)) {
2274 md_write_end(conf->mddev);
2275 bi->bi_next = *return_bi;
2281 /* fail any reads if this device is non-operational and
2282 * the data has not reached the cache yet.
2284 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2285 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2286 test_bit(R5_ReadError, &sh->dev[i].flags))) {
2287 bi = sh->dev[i].toread;
2288 sh->dev[i].toread = NULL;
2289 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2290 wake_up(&conf->wait_for_overlap);
2291 if (bi) s->to_read--;
2292 while (bi && bi->bi_sector <
2293 sh->dev[i].sector + STRIPE_SECTORS) {
2294 struct bio *nextbi =
2295 r5_next_bio(bi, sh->dev[i].sector);
2296 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2297 if (!raid5_dec_bi_phys_segments(bi)) {
2298 bi->bi_next = *return_bi;
2304 spin_unlock_irq(&conf->device_lock);
2306 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2307 STRIPE_SECTORS, 0, 0);
2310 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2311 if (atomic_dec_and_test(&conf->pending_full_writes))
2312 md_wakeup_thread(conf->mddev->thread);
2315 /* fetch_block5 - checks the given member device to see if its data needs
2316 * to be read or computed to satisfy a request.
2318 * Returns 1 when no more member devices need to be checked, otherwise returns
2319 * 0 to tell the loop in handle_stripe_fill5 to continue
2321 static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2322 int disk_idx, int disks)
2324 struct r5dev *dev = &sh->dev[disk_idx];
2325 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2327 /* is the data in this block needed, and can we get it? */
2328 if (!test_bit(R5_LOCKED, &dev->flags) &&
2329 !test_bit(R5_UPTODATE, &dev->flags) &&
2331 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2332 s->syncing || s->expanding ||
2334 (failed_dev->toread ||
2335 (failed_dev->towrite &&
2336 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
2337 /* We would like to get this block, possibly by computing it,
2338 * otherwise read it if the backing disk is insync
2340 if ((s->uptodate == disks - 1) &&
2341 (s->failed && disk_idx == s->failed_num)) {
2342 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2343 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2344 set_bit(R5_Wantcompute, &dev->flags);
2345 sh->ops.target = disk_idx;
2346 sh->ops.target2 = -1;
2348 /* Careful: from this point on 'uptodate' is in the eye
2349 * of raid_run_ops which services 'compute' operations
2350 * before writes. R5_Wantcompute flags a block that will
2351 * be R5_UPTODATE by the time it is needed for a
2352 * subsequent operation.
2355 return 1; /* uptodate + compute == disks */
2356 } else if (test_bit(R5_Insync, &dev->flags)) {
2357 set_bit(R5_LOCKED, &dev->flags);
2358 set_bit(R5_Wantread, &dev->flags);
2360 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2369 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2371 static void handle_stripe_fill5(struct stripe_head *sh,
2372 struct stripe_head_state *s, int disks)
2376 /* look for blocks to read/compute, skip this if a compute
2377 * is already in flight, or if the stripe contents are in the
2378 * midst of changing due to a write
2380 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2381 !sh->reconstruct_state)
2382 for (i = disks; i--; )
2383 if (fetch_block5(sh, s, i, disks))
2385 set_bit(STRIPE_HANDLE, &sh->state);
2388 /* fetch_block6 - checks the given member device to see if its data needs
2389 * to be read or computed to satisfy a request.
2391 * Returns 1 when no more member devices need to be checked, otherwise returns
2392 * 0 to tell the loop in handle_stripe_fill6 to continue
2394 static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
2395 struct r6_state *r6s, int disk_idx, int disks)
2397 struct r5dev *dev = &sh->dev[disk_idx];
2398 struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]],
2399 &sh->dev[r6s->failed_num[1]] };
2401 if (!test_bit(R5_LOCKED, &dev->flags) &&
2402 !test_bit(R5_UPTODATE, &dev->flags) &&
2404 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2405 s->syncing || s->expanding ||
2407 (fdev[0]->toread || s->to_write)) ||
2409 (fdev[1]->toread || s->to_write)))) {
2410 /* we would like to get this block, possibly by computing it,
2411 * otherwise read it if the backing disk is insync
2413 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2414 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2415 if ((s->uptodate == disks - 1) &&
2416 (s->failed && (disk_idx == r6s->failed_num[0] ||
2417 disk_idx == r6s->failed_num[1]))) {
2418 /* have disk failed, and we're requested to fetch it;
2421 pr_debug("Computing stripe %llu block %d\n",
2422 (unsigned long long)sh->sector, disk_idx);
2423 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2424 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2425 set_bit(R5_Wantcompute, &dev->flags);
2426 sh->ops.target = disk_idx;
2427 sh->ops.target2 = -1; /* no 2nd target */
2431 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2432 /* Computing 2-failure is *very* expensive; only
2433 * do it if failed >= 2
2436 for (other = disks; other--; ) {
2437 if (other == disk_idx)
2439 if (!test_bit(R5_UPTODATE,
2440 &sh->dev[other].flags))
2444 pr_debug("Computing stripe %llu blocks %d,%d\n",
2445 (unsigned long long)sh->sector,
2447 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2448 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2449 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2450 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2451 sh->ops.target = disk_idx;
2452 sh->ops.target2 = other;
2456 } else if (test_bit(R5_Insync, &dev->flags)) {
2457 set_bit(R5_LOCKED, &dev->flags);
2458 set_bit(R5_Wantread, &dev->flags);
2460 pr_debug("Reading block %d (sync=%d)\n",
2461 disk_idx, s->syncing);
2469 * handle_stripe_fill6 - read or compute data to satisfy pending requests.
2471 static void handle_stripe_fill6(struct stripe_head *sh,
2472 struct stripe_head_state *s, struct r6_state *r6s,
2477 /* look for blocks to read/compute, skip this if a compute
2478 * is already in flight, or if the stripe contents are in the
2479 * midst of changing due to a write
2481 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2482 !sh->reconstruct_state)
2483 for (i = disks; i--; )
2484 if (fetch_block6(sh, s, r6s, i, disks))
2486 set_bit(STRIPE_HANDLE, &sh->state);
2490 /* handle_stripe_clean_event
2491 * any written block on an uptodate or failed drive can be returned.
2492 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2493 * never LOCKED, so we don't need to test 'failed' directly.
2495 static void handle_stripe_clean_event(raid5_conf_t *conf,
2496 struct stripe_head *sh, int disks, struct bio **return_bi)
2501 for (i = disks; i--; )
2502 if (sh->dev[i].written) {
2504 if (!test_bit(R5_LOCKED, &dev->flags) &&
2505 test_bit(R5_UPTODATE, &dev->flags)) {
2506 /* We can return any write requests */
2507 struct bio *wbi, *wbi2;
2509 pr_debug("Return write for disc %d\n", i);
2510 spin_lock_irq(&conf->device_lock);
2512 dev->written = NULL;
2513 while (wbi && wbi->bi_sector <
2514 dev->sector + STRIPE_SECTORS) {
2515 wbi2 = r5_next_bio(wbi, dev->sector);
2516 if (!raid5_dec_bi_phys_segments(wbi)) {
2517 md_write_end(conf->mddev);
2518 wbi->bi_next = *return_bi;
2523 if (dev->towrite == NULL)
2525 spin_unlock_irq(&conf->device_lock);
2527 bitmap_endwrite(conf->mddev->bitmap,
2530 !test_bit(STRIPE_DEGRADED, &sh->state),
2535 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2536 if (atomic_dec_and_test(&conf->pending_full_writes))
2537 md_wakeup_thread(conf->mddev->thread);
2540 static void handle_stripe_dirtying5(raid5_conf_t *conf,
2541 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2543 int rmw = 0, rcw = 0, i;
2544 for (i = disks; i--; ) {
2545 /* would I have to read this buffer for read_modify_write */
2546 struct r5dev *dev = &sh->dev[i];
2547 if ((dev->towrite || i == sh->pd_idx) &&
2548 !test_bit(R5_LOCKED, &dev->flags) &&
2549 !(test_bit(R5_UPTODATE, &dev->flags) ||
2550 test_bit(R5_Wantcompute, &dev->flags))) {
2551 if (test_bit(R5_Insync, &dev->flags))
2554 rmw += 2*disks; /* cannot read it */
2556 /* Would I have to read this buffer for reconstruct_write */
2557 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2558 !test_bit(R5_LOCKED, &dev->flags) &&
2559 !(test_bit(R5_UPTODATE, &dev->flags) ||
2560 test_bit(R5_Wantcompute, &dev->flags))) {
2561 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2566 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2567 (unsigned long long)sh->sector, rmw, rcw);
2568 set_bit(STRIPE_HANDLE, &sh->state);
2569 if (rmw < rcw && rmw > 0)
2570 /* prefer read-modify-write, but need to get some data */
2571 for (i = disks; i--; ) {
2572 struct r5dev *dev = &sh->dev[i];
2573 if ((dev->towrite || i == sh->pd_idx) &&
2574 !test_bit(R5_LOCKED, &dev->flags) &&
2575 !(test_bit(R5_UPTODATE, &dev->flags) ||
2576 test_bit(R5_Wantcompute, &dev->flags)) &&
2577 test_bit(R5_Insync, &dev->flags)) {
2579 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2580 pr_debug("Read_old block "
2581 "%d for r-m-w\n", i);
2582 set_bit(R5_LOCKED, &dev->flags);
2583 set_bit(R5_Wantread, &dev->flags);
2586 set_bit(STRIPE_DELAYED, &sh->state);
2587 set_bit(STRIPE_HANDLE, &sh->state);
2591 if (rcw <= rmw && rcw > 0)
2592 /* want reconstruct write, but need to get some data */
2593 for (i = disks; i--; ) {
2594 struct r5dev *dev = &sh->dev[i];
2595 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2597 !test_bit(R5_LOCKED, &dev->flags) &&
2598 !(test_bit(R5_UPTODATE, &dev->flags) ||
2599 test_bit(R5_Wantcompute, &dev->flags)) &&
2600 test_bit(R5_Insync, &dev->flags)) {
2602 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2603 pr_debug("Read_old block "
2604 "%d for Reconstruct\n", i);
2605 set_bit(R5_LOCKED, &dev->flags);
2606 set_bit(R5_Wantread, &dev->flags);
2609 set_bit(STRIPE_DELAYED, &sh->state);
2610 set_bit(STRIPE_HANDLE, &sh->state);
2614 /* now if nothing is locked, and if we have enough data,
2615 * we can start a write request
2617 /* since handle_stripe can be called at any time we need to handle the
2618 * case where a compute block operation has been submitted and then a
2619 * subsequent call wants to start a write request. raid_run_ops only
2620 * handles the case where compute block and reconstruct are requested
2621 * simultaneously. If this is not the case then new writes need to be
2622 * held off until the compute completes.
2624 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2625 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2626 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
2627 schedule_reconstruction(sh, s, rcw == 0, 0);
2630 static void handle_stripe_dirtying6(raid5_conf_t *conf,
2631 struct stripe_head *sh, struct stripe_head_state *s,
2632 struct r6_state *r6s, int disks)
2634 int rcw = 0, pd_idx = sh->pd_idx, i;
2635 int qd_idx = sh->qd_idx;
2637 set_bit(STRIPE_HANDLE, &sh->state);
2638 for (i = disks; i--; ) {
2639 struct r5dev *dev = &sh->dev[i];
2640 /* check if we haven't enough data */
2641 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2642 i != pd_idx && i != qd_idx &&
2643 !test_bit(R5_LOCKED, &dev->flags) &&
2644 !(test_bit(R5_UPTODATE, &dev->flags) ||
2645 test_bit(R5_Wantcompute, &dev->flags))) {
2647 if (!test_bit(R5_Insync, &dev->flags))
2648 continue; /* it's a failed drive */
2651 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2652 pr_debug("Read_old stripe %llu "
2653 "block %d for Reconstruct\n",
2654 (unsigned long long)sh->sector, i);
2655 set_bit(R5_LOCKED, &dev->flags);
2656 set_bit(R5_Wantread, &dev->flags);
2659 pr_debug("Request delayed stripe %llu "
2660 "block %d for Reconstruct\n",
2661 (unsigned long long)sh->sector, i);
2662 set_bit(STRIPE_DELAYED, &sh->state);
2663 set_bit(STRIPE_HANDLE, &sh->state);
2667 /* now if nothing is locked, and if we have enough data, we can start a
2670 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2671 s->locked == 0 && rcw == 0 &&
2672 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2673 schedule_reconstruction(sh, s, 1, 0);
2677 static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2678 struct stripe_head_state *s, int disks)
2680 struct r5dev *dev = NULL;
2682 set_bit(STRIPE_HANDLE, &sh->state);
2684 switch (sh->check_state) {
2685 case check_state_idle:
2686 /* start a new check operation if there are no failures */
2687 if (s->failed == 0) {
2688 BUG_ON(s->uptodate != disks);
2689 sh->check_state = check_state_run;
2690 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2691 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2695 dev = &sh->dev[s->failed_num];
2697 case check_state_compute_result:
2698 sh->check_state = check_state_idle;
2700 dev = &sh->dev[sh->pd_idx];
2702 /* check that a write has not made the stripe insync */
2703 if (test_bit(STRIPE_INSYNC, &sh->state))
2706 /* either failed parity check, or recovery is happening */
2707 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2708 BUG_ON(s->uptodate != disks);
2710 set_bit(R5_LOCKED, &dev->flags);
2712 set_bit(R5_Wantwrite, &dev->flags);
2714 clear_bit(STRIPE_DEGRADED, &sh->state);
2715 set_bit(STRIPE_INSYNC, &sh->state);
2717 case check_state_run:
2718 break; /* we will be called again upon completion */
2719 case check_state_check_result:
2720 sh->check_state = check_state_idle;
2722 /* if a failure occurred during the check operation, leave
2723 * STRIPE_INSYNC not set and let the stripe be handled again
2728 /* handle a successful check operation, if parity is correct
2729 * we are done. Otherwise update the mismatch count and repair
2730 * parity if !MD_RECOVERY_CHECK
2732 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
2733 /* parity is correct (on disc,
2734 * not in buffer any more)
2736 set_bit(STRIPE_INSYNC, &sh->state);
2738 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2739 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2740 /* don't try to repair!! */
2741 set_bit(STRIPE_INSYNC, &sh->state);
2743 sh->check_state = check_state_compute_run;
2744 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2745 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2746 set_bit(R5_Wantcompute,
2747 &sh->dev[sh->pd_idx].flags);
2748 sh->ops.target = sh->pd_idx;
2749 sh->ops.target2 = -1;
2754 case check_state_compute_run:
2757 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2758 __func__, sh->check_state,
2759 (unsigned long long) sh->sector);
2765 static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2766 struct stripe_head_state *s,
2767 struct r6_state *r6s, int disks)
2769 int pd_idx = sh->pd_idx;
2770 int qd_idx = sh->qd_idx;
2773 set_bit(STRIPE_HANDLE, &sh->state);
2775 BUG_ON(s->failed > 2);
2777 /* Want to check and possibly repair P and Q.
2778 * However there could be one 'failed' device, in which
2779 * case we can only check one of them, possibly using the
2780 * other to generate missing data
2783 switch (sh->check_state) {
2784 case check_state_idle:
2785 /* start a new check operation if there are < 2 failures */
2786 if (s->failed == r6s->q_failed) {
2787 /* The only possible failed device holds Q, so it
2788 * makes sense to check P (If anything else were failed,
2789 * we would have used P to recreate it).
2791 sh->check_state = check_state_run;
2793 if (!r6s->q_failed && s->failed < 2) {
2794 /* Q is not failed, and we didn't use it to generate
2795 * anything, so it makes sense to check it
2797 if (sh->check_state == check_state_run)
2798 sh->check_state = check_state_run_pq;
2800 sh->check_state = check_state_run_q;
2803 /* discard potentially stale zero_sum_result */
2804 sh->ops.zero_sum_result = 0;
2806 if (sh->check_state == check_state_run) {
2807 /* async_xor_zero_sum destroys the contents of P */
2808 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2811 if (sh->check_state >= check_state_run &&
2812 sh->check_state <= check_state_run_pq) {
2813 /* async_syndrome_zero_sum preserves P and Q, so
2814 * no need to mark them !uptodate here
2816 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2820 /* we have 2-disk failure */
2821 BUG_ON(s->failed != 2);
2823 case check_state_compute_result:
2824 sh->check_state = check_state_idle;
2826 /* check that a write has not made the stripe insync */
2827 if (test_bit(STRIPE_INSYNC, &sh->state))
2830 /* now write out any block on a failed drive,
2831 * or P or Q if they were recomputed
2833 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
2834 if (s->failed == 2) {
2835 dev = &sh->dev[r6s->failed_num[1]];
2837 set_bit(R5_LOCKED, &dev->flags);
2838 set_bit(R5_Wantwrite, &dev->flags);
2840 if (s->failed >= 1) {
2841 dev = &sh->dev[r6s->failed_num[0]];
2843 set_bit(R5_LOCKED, &dev->flags);
2844 set_bit(R5_Wantwrite, &dev->flags);
2846 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2847 dev = &sh->dev[pd_idx];
2849 set_bit(R5_LOCKED, &dev->flags);
2850 set_bit(R5_Wantwrite, &dev->flags);
2852 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2853 dev = &sh->dev[qd_idx];
2855 set_bit(R5_LOCKED, &dev->flags);
2856 set_bit(R5_Wantwrite, &dev->flags);
2858 clear_bit(STRIPE_DEGRADED, &sh->state);
2860 set_bit(STRIPE_INSYNC, &sh->state);
2862 case check_state_run:
2863 case check_state_run_q:
2864 case check_state_run_pq:
2865 break; /* we will be called again upon completion */
2866 case check_state_check_result:
2867 sh->check_state = check_state_idle;
2869 /* handle a successful check operation, if parity is correct
2870 * we are done. Otherwise update the mismatch count and repair
2871 * parity if !MD_RECOVERY_CHECK
2873 if (sh->ops.zero_sum_result == 0) {
2874 /* both parities are correct */
2876 set_bit(STRIPE_INSYNC, &sh->state);
2878 /* in contrast to the raid5 case we can validate
2879 * parity, but still have a failure to write
2882 sh->check_state = check_state_compute_result;
2883 /* Returning at this point means that we may go
2884 * off and bring p and/or q uptodate again so
2885 * we make sure to check zero_sum_result again
2886 * to verify if p or q need writeback
2890 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2891 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2892 /* don't try to repair!! */
2893 set_bit(STRIPE_INSYNC, &sh->state);
2895 int *target = &sh->ops.target;
2897 sh->ops.target = -1;
2898 sh->ops.target2 = -1;
2899 sh->check_state = check_state_compute_run;
2900 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2901 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2902 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2903 set_bit(R5_Wantcompute,
2904 &sh->dev[pd_idx].flags);
2906 target = &sh->ops.target2;
2909 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2910 set_bit(R5_Wantcompute,
2911 &sh->dev[qd_idx].flags);
2918 case check_state_compute_run:
2921 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2922 __func__, sh->check_state,
2923 (unsigned long long) sh->sector);
2928 static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2929 struct r6_state *r6s)
2933 /* We have read all the blocks in this stripe and now we need to
2934 * copy some of them into a target stripe for expand.
2936 struct dma_async_tx_descriptor *tx = NULL;
2937 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2938 for (i = 0; i < sh->disks; i++)
2939 if (i != sh->pd_idx && i != sh->qd_idx) {
2941 struct stripe_head *sh2;
2942 struct async_submit_ctl submit;
2944 sector_t bn = compute_blocknr(sh, i, 1);
2945 sector_t s = raid5_compute_sector(conf, bn, 0,
2947 sh2 = get_active_stripe(conf, s, 0, 1, 1);
2949 /* so far only the early blocks of this stripe
2950 * have been requested. When later blocks
2951 * get requested, we will try again
2954 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2955 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2956 /* must have already done this block */
2957 release_stripe(sh2);
2961 /* place all the copies on one channel */
2962 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
2963 tx = async_memcpy(sh2->dev[dd_idx].page,
2964 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2967 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2968 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2969 for (j = 0; j < conf->raid_disks; j++)
2970 if (j != sh2->pd_idx &&
2971 (!r6s || j != sh2->qd_idx) &&
2972 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2974 if (j == conf->raid_disks) {
2975 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2976 set_bit(STRIPE_HANDLE, &sh2->state);
2978 release_stripe(sh2);
2981 /* done submitting copies, wait for them to complete */
2984 dma_wait_for_async_tx(tx);
2990 * handle_stripe - do things to a stripe.
2992 * We lock the stripe and then examine the state of various bits
2993 * to see what needs to be done.
2995 * return some read request which now have data
2996 * return some write requests which are safely on disc
2997 * schedule a read on some buffers
2998 * schedule a write of some buffers
2999 * return confirmation of parity correctness
3001 * buffers are taken off read_list or write_list, and bh_cache buffers
3002 * get BH_Lock set before the stripe lock is released.
3006 static void handle_stripe5(struct stripe_head *sh)
3008 raid5_conf_t *conf = sh->raid_conf;
3009 int disks = sh->disks, i;
3010 struct bio *return_bi = NULL;
3011 struct stripe_head_state s;
3013 mdk_rdev_t *blocked_rdev = NULL;
3015 int dec_preread_active = 0;
3017 memset(&s, 0, sizeof(s));
3018 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
3019 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
3020 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
3021 sh->reconstruct_state);
3023 spin_lock(&sh->lock);
3024 clear_bit(STRIPE_HANDLE, &sh->state);
3025 clear_bit(STRIPE_DELAYED, &sh->state);
3027 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3028 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3029 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3031 /* Now to look around and see what can be done */
3033 for (i=disks; i--; ) {
3038 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
3039 "written %p\n", i, dev->flags, dev->toread, dev->read,
3040 dev->towrite, dev->written);
3042 /* maybe we can request a biofill operation
3044 * new wantfill requests are only permitted while
3045 * ops_complete_biofill is guaranteed to be inactive
3047 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3048 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3049 set_bit(R5_Wantfill, &dev->flags);
3051 /* now count some things */
3052 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3053 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
3054 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
3056 if (test_bit(R5_Wantfill, &dev->flags))
3058 else if (dev->toread)
3062 if (!test_bit(R5_OVERWRITE, &dev->flags))
3067 rdev = rcu_dereference(conf->disks[i].rdev);
3068 if (blocked_rdev == NULL &&
3069 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3070 blocked_rdev = rdev;
3071 atomic_inc(&rdev->nr_pending);
3073 clear_bit(R5_Insync, &dev->flags);
3076 else if (test_bit(In_sync, &rdev->flags))
3077 set_bit(R5_Insync, &dev->flags);
3079 /* could be in-sync depending on recovery/reshape status */
3080 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3081 set_bit(R5_Insync, &dev->flags);
3083 if (!test_bit(R5_Insync, &dev->flags)) {
3084 /* The ReadError flag will just be confusing now */
3085 clear_bit(R5_ReadError, &dev->flags);
3086 clear_bit(R5_ReWrite, &dev->flags);
3088 if (test_bit(R5_ReadError, &dev->flags))
3089 clear_bit(R5_Insync, &dev->flags);
3090 if (!test_bit(R5_Insync, &dev->flags)) {
3097 if (unlikely(blocked_rdev)) {
3098 if (s.syncing || s.expanding || s.expanded ||
3099 s.to_write || s.written) {
3100 set_bit(STRIPE_HANDLE, &sh->state);
3103 /* There is nothing for the blocked_rdev to block */
3104 rdev_dec_pending(blocked_rdev, conf->mddev);
3105 blocked_rdev = NULL;
3108 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3109 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3110 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3113 pr_debug("locked=%d uptodate=%d to_read=%d"
3114 " to_write=%d failed=%d failed_num=%d\n",
3115 s.locked, s.uptodate, s.to_read, s.to_write,
3116 s.failed, s.failed_num);
3117 /* check if the array has lost two devices and, if so, some requests might
3120 if (s.failed > 1 && s.to_read+s.to_write+s.written)
3121 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
3122 if (s.failed > 1 && s.syncing) {
3123 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3124 clear_bit(STRIPE_SYNCING, &sh->state);
3128 /* might be able to return some write requests if the parity block
3129 * is safe, or on a failed drive
3131 dev = &sh->dev[sh->pd_idx];
3133 ((test_bit(R5_Insync, &dev->flags) &&
3134 !test_bit(R5_LOCKED, &dev->flags) &&
3135 test_bit(R5_UPTODATE, &dev->flags)) ||
3136 (s.failed == 1 && s.failed_num == sh->pd_idx)))
3137 handle_stripe_clean_event(conf, sh, disks, &return_bi);
3139 /* Now we might consider reading some blocks, either to check/generate
3140 * parity, or to satisfy requests
3141 * or to load a block that is being partially written.
3143 if (s.to_read || s.non_overwrite ||
3144 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
3145 handle_stripe_fill5(sh, &s, disks);
3147 /* Now we check to see if any write operations have recently
3151 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3153 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3154 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3155 sh->reconstruct_state = reconstruct_state_idle;
3157 /* All the 'written' buffers and the parity block are ready to
3158 * be written back to disk
3160 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3161 for (i = disks; i--; ) {
3163 if (test_bit(R5_LOCKED, &dev->flags) &&
3164 (i == sh->pd_idx || dev->written)) {
3165 pr_debug("Writing block %d\n", i);
3166 set_bit(R5_Wantwrite, &dev->flags);
3169 if (!test_bit(R5_Insync, &dev->flags) ||
3170 (i == sh->pd_idx && s.failed == 0))
3171 set_bit(STRIPE_INSYNC, &sh->state);
3174 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3175 dec_preread_active = 1;
3178 /* Now to consider new write requests and what else, if anything
3179 * should be read. We do not handle new writes when:
3180 * 1/ A 'write' operation (copy+xor) is already in flight.
3181 * 2/ A 'check' operation is in flight, as it may clobber the parity
3184 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3185 handle_stripe_dirtying5(conf, sh, &s, disks);
3187 /* maybe we need to check and possibly fix the parity for this stripe
3188 * Any reads will already have been scheduled, so we just see if enough
3189 * data is available. The parity check is held off while parity
3190 * dependent operations are in flight.
3192 if (sh->check_state ||
3193 (s.syncing && s.locked == 0 &&
3194 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3195 !test_bit(STRIPE_INSYNC, &sh->state)))
3196 handle_parity_checks5(conf, sh, &s, disks);
3198 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3199 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3200 clear_bit(STRIPE_SYNCING, &sh->state);
3203 /* If the failed drive is just a ReadError, then we might need to progress
3204 * the repair/check process
3206 if (s.failed == 1 && !conf->mddev->ro &&
3207 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
3208 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
3209 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
3211 dev = &sh->dev[s.failed_num];
3212 if (!test_bit(R5_ReWrite, &dev->flags)) {
3213 set_bit(R5_Wantwrite, &dev->flags);
3214 set_bit(R5_ReWrite, &dev->flags);
3215 set_bit(R5_LOCKED, &dev->flags);
3218 /* let's read it back */
3219 set_bit(R5_Wantread, &dev->flags);
3220 set_bit(R5_LOCKED, &dev->flags);
3225 /* Finish reconstruct operations initiated by the expansion process */
3226 if (sh->reconstruct_state == reconstruct_state_result) {
3227 struct stripe_head *sh2
3228 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3229 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3230 /* sh cannot be written until sh2 has been read.
3231 * so arrange for sh to be delayed a little
3233 set_bit(STRIPE_DELAYED, &sh->state);
3234 set_bit(STRIPE_HANDLE, &sh->state);
3235 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3237 atomic_inc(&conf->preread_active_stripes);
3238 release_stripe(sh2);
3242 release_stripe(sh2);
3244 sh->reconstruct_state = reconstruct_state_idle;
3245 clear_bit(STRIPE_EXPANDING, &sh->state);
3246 for (i = conf->raid_disks; i--; ) {
3247 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3248 set_bit(R5_LOCKED, &sh->dev[i].flags);
3253 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3254 !sh->reconstruct_state) {
3255 /* Need to write out all blocks after computing parity */
3256 sh->disks = conf->raid_disks;
3257 stripe_set_idx(sh->sector, conf, 0, sh);
3258 schedule_reconstruction(sh, &s, 1, 1);
3259 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3260 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3261 atomic_dec(&conf->reshape_stripes);
3262 wake_up(&conf->wait_for_overlap);
3263 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3266 if (s.expanding && s.locked == 0 &&
3267 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3268 handle_stripe_expansion(conf, sh, NULL);
3271 spin_unlock(&sh->lock);
3273 /* wait for this device to become unblocked */
3274 if (unlikely(blocked_rdev))
3275 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3278 raid_run_ops(sh, s.ops_request);
3282 if (dec_preread_active) {
3283 /* We delay this until after ops_run_io so that if make_request
3284 * is waiting on a barrier, it won't continue until the writes
3285 * have actually been submitted.
3287 atomic_dec(&conf->preread_active_stripes);
3288 if (atomic_read(&conf->preread_active_stripes) <
3290 md_wakeup_thread(conf->mddev->thread);
3292 return_io(return_bi);
3295 static void handle_stripe6(struct stripe_head *sh)
3297 raid5_conf_t *conf = sh->raid_conf;
3298 int disks = sh->disks;
3299 struct bio *return_bi = NULL;
3300 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
3301 struct stripe_head_state s;
3302 struct r6_state r6s;
3303 struct r5dev *dev, *pdev, *qdev;
3304 mdk_rdev_t *blocked_rdev = NULL;
3305 int dec_preread_active = 0;
3307 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3308 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3309 (unsigned long long)sh->sector, sh->state,
3310 atomic_read(&sh->count), pd_idx, qd_idx,
3311 sh->check_state, sh->reconstruct_state);
3312 memset(&s, 0, sizeof(s));
3314 spin_lock(&sh->lock);
3315 clear_bit(STRIPE_HANDLE, &sh->state);
3316 clear_bit(STRIPE_DELAYED, &sh->state);
3318 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3319 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3320 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3321 /* Now to look around and see what can be done */
3324 for (i=disks; i--; ) {
3328 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3329 i, dev->flags, dev->toread, dev->towrite, dev->written);
3330 /* maybe we can reply to a read
3332 * new wantfill requests are only permitted while
3333 * ops_complete_biofill is guaranteed to be inactive
3335 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3336 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3337 set_bit(R5_Wantfill, &dev->flags);
3339 /* now count some things */
3340 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3341 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
3342 if (test_bit(R5_Wantcompute, &dev->flags)) {
3344 BUG_ON(s.compute > 2);
3347 if (test_bit(R5_Wantfill, &dev->flags)) {
3349 } else if (dev->toread)
3353 if (!test_bit(R5_OVERWRITE, &dev->flags))
3358 rdev = rcu_dereference(conf->disks[i].rdev);
3359 if (blocked_rdev == NULL &&
3360 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3361 blocked_rdev = rdev;
3362 atomic_inc(&rdev->nr_pending);
3364 clear_bit(R5_Insync, &dev->flags);
3367 else if (test_bit(In_sync, &rdev->flags))
3368 set_bit(R5_Insync, &dev->flags);
3370 /* in sync if before recovery_offset */
3371 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3372 set_bit(R5_Insync, &dev->flags);
3374 if (!test_bit(R5_Insync, &dev->flags)) {
3375 /* The ReadError flag will just be confusing now */
3376 clear_bit(R5_ReadError, &dev->flags);
3377 clear_bit(R5_ReWrite, &dev->flags);
3379 if (test_bit(R5_ReadError, &dev->flags))
3380 clear_bit(R5_Insync, &dev->flags);
3381 if (!test_bit(R5_Insync, &dev->flags)) {
3383 r6s.failed_num[s.failed] = i;
3389 if (unlikely(blocked_rdev)) {
3390 if (s.syncing || s.expanding || s.expanded ||
3391 s.to_write || s.written) {
3392 set_bit(STRIPE_HANDLE, &sh->state);
3395 /* There is nothing for the blocked_rdev to block */
3396 rdev_dec_pending(blocked_rdev, conf->mddev);
3397 blocked_rdev = NULL;
3400 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3401 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3402 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3405 pr_debug("locked=%d uptodate=%d to_read=%d"
3406 " to_write=%d failed=%d failed_num=%d,%d\n",
3407 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3408 r6s.failed_num[0], r6s.failed_num[1]);
3409 /* check if the array has lost >2 devices and, if so, some requests
3410 * might need to be failed
3412 if (s.failed > 2 && s.to_read+s.to_write+s.written)
3413 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
3414 if (s.failed > 2 && s.syncing) {
3415 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3416 clear_bit(STRIPE_SYNCING, &sh->state);
3421 * might be able to return some write requests if the parity blocks
3422 * are safe, or on a failed drive
3424 pdev = &sh->dev[pd_idx];
3425 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3426 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
3427 qdev = &sh->dev[qd_idx];
3428 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3429 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
3432 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3433 && !test_bit(R5_LOCKED, &pdev->flags)
3434 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3435 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3436 && !test_bit(R5_LOCKED, &qdev->flags)
3437 && test_bit(R5_UPTODATE, &qdev->flags)))))
3438 handle_stripe_clean_event(conf, sh, disks, &return_bi);
3440 /* Now we might consider reading some blocks, either to check/generate
3441 * parity, or to satisfy requests
3442 * or to load a block that is being partially written.
3444 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3445 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
3446 handle_stripe_fill6(sh, &s, &r6s, disks);
3448 /* Now we check to see if any write operations have recently
3451 if (sh->reconstruct_state == reconstruct_state_drain_result) {
3453 sh->reconstruct_state = reconstruct_state_idle;
3454 /* All the 'written' buffers and the parity blocks are ready to
3455 * be written back to disk
3457 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3458 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
3459 for (i = disks; i--; ) {
3461 if (test_bit(R5_LOCKED, &dev->flags) &&
3462 (i == sh->pd_idx || i == qd_idx ||
3464 pr_debug("Writing block %d\n", i);
3465 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3466 set_bit(R5_Wantwrite, &dev->flags);
3467 if (!test_bit(R5_Insync, &dev->flags) ||
3468 ((i == sh->pd_idx || i == qd_idx) &&
3470 set_bit(STRIPE_INSYNC, &sh->state);
3473 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3474 dec_preread_active = 1;
3477 /* Now to consider new write requests and what else, if anything
3478 * should be read. We do not handle new writes when:
3479 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3480 * 2/ A 'check' operation is in flight, as it may clobber the parity
3483 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3484 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
3486 /* maybe we need to check and possibly fix the parity for this stripe
3487 * Any reads will already have been scheduled, so we just see if enough
3488 * data is available. The parity check is held off while parity
3489 * dependent operations are in flight.
3491 if (sh->check_state ||
3492 (s.syncing && s.locked == 0 &&
3493 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3494 !test_bit(STRIPE_INSYNC, &sh->state)))
3495 handle_parity_checks6(conf, sh, &s, &r6s, disks);
3497 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3498 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3499 clear_bit(STRIPE_SYNCING, &sh->state);
3502 /* If the failed drives are just a ReadError, then we might need
3503 * to progress the repair/check process
3505 if (s.failed <= 2 && !conf->mddev->ro)
3506 for (i = 0; i < s.failed; i++) {
3507 dev = &sh->dev[r6s.failed_num[i]];
3508 if (test_bit(R5_ReadError, &dev->flags)
3509 && !test_bit(R5_LOCKED, &dev->flags)
3510 && test_bit(R5_UPTODATE, &dev->flags)
3512 if (!test_bit(R5_ReWrite, &dev->flags)) {
3513 set_bit(R5_Wantwrite, &dev->flags);
3514 set_bit(R5_ReWrite, &dev->flags);
3515 set_bit(R5_LOCKED, &dev->flags);
3518 /* let's read it back */
3519 set_bit(R5_Wantread, &dev->flags);
3520 set_bit(R5_LOCKED, &dev->flags);
3526 /* Finish reconstruct operations initiated by the expansion process */
3527 if (sh->reconstruct_state == reconstruct_state_result) {
3528 sh->reconstruct_state = reconstruct_state_idle;
3529 clear_bit(STRIPE_EXPANDING, &sh->state);
3530 for (i = conf->raid_disks; i--; ) {
3531 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3532 set_bit(R5_LOCKED, &sh->dev[i].flags);
3537 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3538 !sh->reconstruct_state) {
3539 struct stripe_head *sh2
3540 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3541 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3542 /* sh cannot be written until sh2 has been read.
3543 * so arrange for sh to be delayed a little
3545 set_bit(STRIPE_DELAYED, &sh->state);
3546 set_bit(STRIPE_HANDLE, &sh->state);
3547 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3549 atomic_inc(&conf->preread_active_stripes);
3550 release_stripe(sh2);
3554 release_stripe(sh2);
3556 /* Need to write out all blocks after computing P&Q */
3557 sh->disks = conf->raid_disks;
3558 stripe_set_idx(sh->sector, conf, 0, sh);
3559 schedule_reconstruction(sh, &s, 1, 1);
3560 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3561 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3562 atomic_dec(&conf->reshape_stripes);
3563 wake_up(&conf->wait_for_overlap);
3564 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3567 if (s.expanding && s.locked == 0 &&
3568 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3569 handle_stripe_expansion(conf, sh, &r6s);
3572 spin_unlock(&sh->lock);
3574 /* wait for this device to become unblocked */
3575 if (unlikely(blocked_rdev))
3576 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3579 raid_run_ops(sh, s.ops_request);
3584 if (dec_preread_active) {
3585 /* We delay this until after ops_run_io so that if make_request
3586 * is waiting on a barrier, it won't continue until the writes
3587 * have actually been submitted.
3589 atomic_dec(&conf->preread_active_stripes);
3590 if (atomic_read(&conf->preread_active_stripes) <
3592 md_wakeup_thread(conf->mddev->thread);
3595 return_io(return_bi);
3598 static void handle_stripe(struct stripe_head *sh)
3600 if (sh->raid_conf->level == 6)
3606 static void raid5_activate_delayed(raid5_conf_t *conf)
3608 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3609 while (!list_empty(&conf->delayed_list)) {
3610 struct list_head *l = conf->delayed_list.next;
3611 struct stripe_head *sh;
3612 sh = list_entry(l, struct stripe_head, lru);
3614 clear_bit(STRIPE_DELAYED, &sh->state);
3615 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3616 atomic_inc(&conf->preread_active_stripes);
3617 list_add_tail(&sh->lru, &conf->hold_list);
3620 plugger_set_plug(&conf->plug);
3623 static void activate_bit_delay(raid5_conf_t *conf)
3625 /* device_lock is held */
3626 struct list_head head;
3627 list_add(&head, &conf->bitmap_list);
3628 list_del_init(&conf->bitmap_list);
3629 while (!list_empty(&head)) {
3630 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3631 list_del_init(&sh->lru);
3632 atomic_inc(&sh->count);
3633 __release_stripe(conf, sh);
3637 static void unplug_slaves(mddev_t *mddev)
3639 raid5_conf_t *conf = mddev->private;
3641 int devs = max(conf->raid_disks, conf->previous_raid_disks);
3644 for (i = 0; i < devs; i++) {
3645 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
3646 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
3647 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
3649 atomic_inc(&rdev->nr_pending);
3652 blk_unplug(r_queue);
3654 rdev_dec_pending(rdev, mddev);
3661 void md_raid5_unplug_device(raid5_conf_t *conf)
3663 unsigned long flags;
3665 spin_lock_irqsave(&conf->device_lock, flags);
3667 if (plugger_remove_plug(&conf->plug)) {
3669 raid5_activate_delayed(conf);
3671 md_wakeup_thread(conf->mddev->thread);
3673 spin_unlock_irqrestore(&conf->device_lock, flags);
3675 unplug_slaves(conf->mddev);
3677 EXPORT_SYMBOL_GPL(md_raid5_unplug_device);
3679 static void raid5_unplug(struct plug_handle *plug)
3681 raid5_conf_t *conf = container_of(plug, raid5_conf_t, plug);
3682 md_raid5_unplug_device(conf);
3685 static void raid5_unplug_queue(struct request_queue *q)
3687 mddev_t *mddev = q->queuedata;
3688 md_raid5_unplug_device(mddev->private);
3691 int md_raid5_congested(mddev_t *mddev, int bits)
3693 raid5_conf_t *conf = mddev->private;
3695 /* No difference between reads and writes. Just check
3696 * how busy the stripe_cache is
3699 if (conf->inactive_blocked)
3703 if (list_empty_careful(&conf->inactive_list))
3708 EXPORT_SYMBOL_GPL(md_raid5_congested);
3710 static int raid5_congested(void *data, int bits)
3712 mddev_t *mddev = data;
3714 return mddev_congested(mddev, bits) ||
3715 md_raid5_congested(mddev, bits);
3718 /* We want read requests to align with chunks where possible,
3719 * but write requests don't need to.
3721 static int raid5_mergeable_bvec(struct request_queue *q,
3722 struct bvec_merge_data *bvm,
3723 struct bio_vec *biovec)
3725 mddev_t *mddev = q->queuedata;
3726 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
3728 unsigned int chunk_sectors = mddev->chunk_sectors;
3729 unsigned int bio_sectors = bvm->bi_size >> 9;
3731 if ((bvm->bi_rw & 1) == WRITE)
3732 return biovec->bv_len; /* always allow writes to be mergeable */
3734 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3735 chunk_sectors = mddev->new_chunk_sectors;
3736 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3737 if (max < 0) max = 0;
3738 if (max <= biovec->bv_len && bio_sectors == 0)
3739 return biovec->bv_len;
3745 static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3747 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3748 unsigned int chunk_sectors = mddev->chunk_sectors;
3749 unsigned int bio_sectors = bio->bi_size >> 9;
3751 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3752 chunk_sectors = mddev->new_chunk_sectors;
3753 return chunk_sectors >=
3754 ((sector & (chunk_sectors - 1)) + bio_sectors);
3758 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3759 * later sampled by raid5d.
3761 static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3763 unsigned long flags;
3765 spin_lock_irqsave(&conf->device_lock, flags);
3767 bi->bi_next = conf->retry_read_aligned_list;
3768 conf->retry_read_aligned_list = bi;
3770 spin_unlock_irqrestore(&conf->device_lock, flags);
3771 md_wakeup_thread(conf->mddev->thread);
3775 static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3779 bi = conf->retry_read_aligned;
3781 conf->retry_read_aligned = NULL;
3784 bi = conf->retry_read_aligned_list;
3786 conf->retry_read_aligned_list = bi->bi_next;
3789 * this sets the active strip count to 1 and the processed
3790 * strip count to zero (upper 8 bits)
3792 bi->bi_phys_segments = 1; /* biased count of active stripes */
3800 * The "raid5_align_endio" should check if the read succeeded and if it
3801 * did, call bio_endio on the original bio (having bio_put the new bio
3803 * If the read failed..
3805 static void raid5_align_endio(struct bio *bi, int error)
3807 struct bio* raid_bi = bi->bi_private;
3810 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3815 rdev = (void*)raid_bi->bi_next;
3816 raid_bi->bi_next = NULL;
3817 mddev = rdev->mddev;
3818 conf = mddev->private;
3820 rdev_dec_pending(rdev, conf->mddev);
3822 if (!error && uptodate) {
3823 bio_endio(raid_bi, 0);
3824 if (atomic_dec_and_test(&conf->active_aligned_reads))
3825 wake_up(&conf->wait_for_stripe);
3830 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3832 add_bio_to_retry(raid_bi, conf);
3835 static int bio_fits_rdev(struct bio *bi)
3837 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
3839 if ((bi->bi_size>>9) > queue_max_sectors(q))
3841 blk_recount_segments(q, bi);
3842 if (bi->bi_phys_segments > queue_max_segments(q))
3845 if (q->merge_bvec_fn)
3846 /* it's too hard to apply the merge_bvec_fn at this stage,
3855 static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
3857 raid5_conf_t *conf = mddev->private;
3859 struct bio* align_bi;
3862 if (!in_chunk_boundary(mddev, raid_bio)) {
3863 pr_debug("chunk_aligned_read : non aligned\n");
3867 * use bio_clone to make a copy of the bio
3869 align_bi = bio_clone(raid_bio, GFP_NOIO);
3873 * set bi_end_io to a new function, and set bi_private to the
3876 align_bi->bi_end_io = raid5_align_endio;
3877 align_bi->bi_private = raid_bio;
3881 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3886 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3887 if (rdev && test_bit(In_sync, &rdev->flags)) {
3888 atomic_inc(&rdev->nr_pending);
3890 raid_bio->bi_next = (void*)rdev;
3891 align_bi->bi_bdev = rdev->bdev;
3892 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3893 align_bi->bi_sector += rdev->data_offset;
3895 if (!bio_fits_rdev(align_bi)) {
3896 /* too big in some way */
3898 rdev_dec_pending(rdev, mddev);
3902 spin_lock_irq(&conf->device_lock);
3903 wait_event_lock_irq(conf->wait_for_stripe,
3905 conf->device_lock, /* nothing */);
3906 atomic_inc(&conf->active_aligned_reads);
3907 spin_unlock_irq(&conf->device_lock);
3909 generic_make_request(align_bi);
3918 /* __get_priority_stripe - get the next stripe to process
3920 * Full stripe writes are allowed to pass preread active stripes up until
3921 * the bypass_threshold is exceeded. In general the bypass_count
3922 * increments when the handle_list is handled before the hold_list; however, it
3923 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3924 * stripe with in flight i/o. The bypass_count will be reset when the
3925 * head of the hold_list has changed, i.e. the head was promoted to the
3928 static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3930 struct stripe_head *sh;
3932 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3934 list_empty(&conf->handle_list) ? "empty" : "busy",
3935 list_empty(&conf->hold_list) ? "empty" : "busy",
3936 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3938 if (!list_empty(&conf->handle_list)) {
3939 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3941 if (list_empty(&conf->hold_list))
3942 conf->bypass_count = 0;
3943 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3944 if (conf->hold_list.next == conf->last_hold)
3945 conf->bypass_count++;
3947 conf->last_hold = conf->hold_list.next;
3948 conf->bypass_count -= conf->bypass_threshold;
3949 if (conf->bypass_count < 0)
3950 conf->bypass_count = 0;
3953 } else if (!list_empty(&conf->hold_list) &&
3954 ((conf->bypass_threshold &&
3955 conf->bypass_count > conf->bypass_threshold) ||
3956 atomic_read(&conf->pending_full_writes) == 0)) {
3957 sh = list_entry(conf->hold_list.next,
3959 conf->bypass_count -= conf->bypass_threshold;
3960 if (conf->bypass_count < 0)
3961 conf->bypass_count = 0;
3965 list_del_init(&sh->lru);
3966 atomic_inc(&sh->count);
3967 BUG_ON(atomic_read(&sh->count) != 1);
3971 static int make_request(mddev_t *mddev, struct bio * bi)
3973 raid5_conf_t *conf = mddev->private;
3975 sector_t new_sector;
3976 sector_t logical_sector, last_sector;
3977 struct stripe_head *sh;
3978 const int rw = bio_data_dir(bi);
3981 if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
3982 /* Drain all pending writes. We only really need
3983 * to ensure they have been submitted, but this is
3986 mddev->pers->quiesce(mddev, 1);
3987 mddev->pers->quiesce(mddev, 0);
3988 md_barrier_request(mddev, bi);
3992 md_write_start(mddev, bi);
3995 mddev->reshape_position == MaxSector &&
3996 chunk_aligned_read(mddev,bi))
3999 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4000 last_sector = bi->bi_sector + (bi->bi_size>>9);
4002 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
4004 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
4006 int disks, data_disks;
4011 disks = conf->raid_disks;
4012 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
4013 if (unlikely(conf->reshape_progress != MaxSector)) {
4014 /* spinlock is needed as reshape_progress may be
4015 * 64bit on a 32bit platform, and so it might be
4016 * possible to see a half-updated value
4017 * Ofcourse reshape_progress could change after
4018 * the lock is dropped, so once we get a reference
4019 * to the stripe that we think it is, we will have
4022 spin_lock_irq(&conf->device_lock);
4023 if (mddev->delta_disks < 0
4024 ? logical_sector < conf->reshape_progress
4025 : logical_sector >= conf->reshape_progress) {
4026 disks = conf->previous_raid_disks;
4029 if (mddev->delta_disks < 0
4030 ? logical_sector < conf->reshape_safe
4031 : logical_sector >= conf->reshape_safe) {
4032 spin_unlock_irq(&conf->device_lock);
4037 spin_unlock_irq(&conf->device_lock);
4039 data_disks = disks - conf->max_degraded;
4041 new_sector = raid5_compute_sector(conf, logical_sector,
4044 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4045 (unsigned long long)new_sector,
4046 (unsigned long long)logical_sector);
4048 sh = get_active_stripe(conf, new_sector, previous,
4049 (bi->bi_rw&RWA_MASK), 0);
4051 if (unlikely(previous)) {
4052 /* expansion might have moved on while waiting for a
4053 * stripe, so we must do the range check again.
4054 * Expansion could still move past after this
4055 * test, but as we are holding a reference to
4056 * 'sh', we know that if that happens,
4057 * STRIPE_EXPANDING will get set and the expansion
4058 * won't proceed until we finish with the stripe.
4061 spin_lock_irq(&conf->device_lock);
4062 if (mddev->delta_disks < 0
4063 ? logical_sector >= conf->reshape_progress
4064 : logical_sector < conf->reshape_progress)
4065 /* mismatch, need to try again */
4067 spin_unlock_irq(&conf->device_lock);
4075 if (bio_data_dir(bi) == WRITE &&
4076 logical_sector >= mddev->suspend_lo &&
4077 logical_sector < mddev->suspend_hi) {
4079 /* As the suspend_* range is controlled by
4080 * userspace, we want an interruptible
4083 flush_signals(current);
4084 prepare_to_wait(&conf->wait_for_overlap,
4085 &w, TASK_INTERRUPTIBLE);
4086 if (logical_sector >= mddev->suspend_lo &&
4087 logical_sector < mddev->suspend_hi)
4092 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
4093 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
4094 /* Stripe is busy expanding or
4095 * add failed due to overlap. Flush everything
4098 md_raid5_unplug_device(conf);
4103 finish_wait(&conf->wait_for_overlap, &w);
4104 set_bit(STRIPE_HANDLE, &sh->state);
4105 clear_bit(STRIPE_DELAYED, &sh->state);
4106 if (mddev->barrier &&
4107 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4108 atomic_inc(&conf->preread_active_stripes);
4111 /* cannot get stripe for read-ahead, just give-up */
4112 clear_bit(BIO_UPTODATE, &bi->bi_flags);
4113 finish_wait(&conf->wait_for_overlap, &w);
4118 spin_lock_irq(&conf->device_lock);
4119 remaining = raid5_dec_bi_phys_segments(bi);
4120 spin_unlock_irq(&conf->device_lock);
4121 if (remaining == 0) {
4124 md_write_end(mddev);
4129 if (mddev->barrier) {
4130 /* We need to wait for the stripes to all be handled.
4131 * So: wait for preread_active_stripes to drop to 0.
4133 wait_event(mddev->thread->wqueue,
4134 atomic_read(&conf->preread_active_stripes) == 0);
4139 static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
4141 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
4143 /* reshaping is quite different to recovery/resync so it is
4144 * handled quite separately ... here.
4146 * On each call to sync_request, we gather one chunk worth of
4147 * destination stripes and flag them as expanding.
4148 * Then we find all the source stripes and request reads.
4149 * As the reads complete, handle_stripe will copy the data
4150 * into the destination stripe and release that stripe.
4152 raid5_conf_t *conf = mddev->private;
4153 struct stripe_head *sh;
4154 sector_t first_sector, last_sector;
4155 int raid_disks = conf->previous_raid_disks;
4156 int data_disks = raid_disks - conf->max_degraded;
4157 int new_data_disks = conf->raid_disks - conf->max_degraded;
4160 sector_t writepos, readpos, safepos;
4161 sector_t stripe_addr;
4162 int reshape_sectors;
4163 struct list_head stripes;
4165 if (sector_nr == 0) {
4166 /* If restarting in the middle, skip the initial sectors */
4167 if (mddev->delta_disks < 0 &&
4168 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4169 sector_nr = raid5_size(mddev, 0, 0)
4170 - conf->reshape_progress;
4171 } else if (mddev->delta_disks >= 0 &&
4172 conf->reshape_progress > 0)
4173 sector_nr = conf->reshape_progress;
4174 sector_div(sector_nr, new_data_disks);
4176 mddev->curr_resync_completed = sector_nr;
4177 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4183 /* We need to process a full chunk at a time.
4184 * If old and new chunk sizes differ, we need to process the
4187 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4188 reshape_sectors = mddev->new_chunk_sectors;
4190 reshape_sectors = mddev->chunk_sectors;
4192 /* we update the metadata when there is more than 3Meg
4193 * in the block range (that is rather arbitrary, should
4194 * probably be time based) or when the data about to be
4195 * copied would over-write the source of the data at
4196 * the front of the range.
4197 * i.e. one new_stripe along from reshape_progress new_maps
4198 * to after where reshape_safe old_maps to
4200 writepos = conf->reshape_progress;
4201 sector_div(writepos, new_data_disks);
4202 readpos = conf->reshape_progress;
4203 sector_div(readpos, data_disks);
4204 safepos = conf->reshape_safe;
4205 sector_div(safepos, data_disks);
4206 if (mddev->delta_disks < 0) {
4207 writepos -= min_t(sector_t, reshape_sectors, writepos);
4208 readpos += reshape_sectors;
4209 safepos += reshape_sectors;
4211 writepos += reshape_sectors;
4212 readpos -= min_t(sector_t, reshape_sectors, readpos);
4213 safepos -= min_t(sector_t, reshape_sectors, safepos);
4216 /* 'writepos' is the most advanced device address we might write.
4217 * 'readpos' is the least advanced device address we might read.
4218 * 'safepos' is the least address recorded in the metadata as having
4220 * If 'readpos' is behind 'writepos', then there is no way that we can
4221 * ensure safety in the face of a crash - that must be done by userspace
4222 * making a backup of the data. So in that case there is no particular
4223 * rush to update metadata.
4224 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4225 * update the metadata to advance 'safepos' to match 'readpos' so that
4226 * we can be safe in the event of a crash.
4227 * So we insist on updating metadata if safepos is behind writepos and
4228 * readpos is beyond writepos.
4229 * In any case, update the metadata every 10 seconds.
4230 * Maybe that number should be configurable, but I'm not sure it is
4231 * worth it.... maybe it could be a multiple of safemode_delay???
4233 if ((mddev->delta_disks < 0
4234 ? (safepos > writepos && readpos < writepos)
4235 : (safepos < writepos && readpos > writepos)) ||
4236 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4237 /* Cannot proceed until we've updated the superblock... */
4238 wait_event(conf->wait_for_overlap,
4239 atomic_read(&conf->reshape_stripes)==0);
4240 mddev->reshape_position = conf->reshape_progress;
4241 mddev->curr_resync_completed = mddev->curr_resync;
4242 conf->reshape_checkpoint = jiffies;
4243 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4244 md_wakeup_thread(mddev->thread);
4245 wait_event(mddev->sb_wait, mddev->flags == 0 ||
4246 kthread_should_stop());
4247 spin_lock_irq(&conf->device_lock);
4248 conf->reshape_safe = mddev->reshape_position;
4249 spin_unlock_irq(&conf->device_lock);
4250 wake_up(&conf->wait_for_overlap);
4251 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4254 if (mddev->delta_disks < 0) {
4255 BUG_ON(conf->reshape_progress == 0);
4256 stripe_addr = writepos;
4257 BUG_ON((mddev->dev_sectors &
4258 ~((sector_t)reshape_sectors - 1))
4259 - reshape_sectors - stripe_addr
4262 BUG_ON(writepos != sector_nr + reshape_sectors);
4263 stripe_addr = sector_nr;
4265 INIT_LIST_HEAD(&stripes);
4266 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
4268 int skipped_disk = 0;
4269 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
4270 set_bit(STRIPE_EXPANDING, &sh->state);
4271 atomic_inc(&conf->reshape_stripes);
4272 /* If any of this stripe is beyond the end of the old
4273 * array, then we need to zero those blocks
4275 for (j=sh->disks; j--;) {
4277 if (j == sh->pd_idx)
4279 if (conf->level == 6 &&
4282 s = compute_blocknr(sh, j, 0);
4283 if (s < raid5_size(mddev, 0, 0)) {
4287 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4288 set_bit(R5_Expanded, &sh->dev[j].flags);
4289 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4291 if (!skipped_disk) {
4292 set_bit(STRIPE_EXPAND_READY, &sh->state);
4293 set_bit(STRIPE_HANDLE, &sh->state);
4295 list_add(&sh->lru, &stripes);
4297 spin_lock_irq(&conf->device_lock);
4298 if (mddev->delta_disks < 0)
4299 conf->reshape_progress -= reshape_sectors * new_data_disks;
4301 conf->reshape_progress += reshape_sectors * new_data_disks;
4302 spin_unlock_irq(&conf->device_lock);
4303 /* Ok, those stripe are ready. We can start scheduling
4304 * reads on the source stripes.
4305 * The source stripes are determined by mapping the first and last
4306 * block on the destination stripes.
4309 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
4312 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
4313 * new_data_disks - 1),
4315 if (last_sector >= mddev->dev_sectors)
4316 last_sector = mddev->dev_sectors - 1;
4317 while (first_sector <= last_sector) {
4318 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
4319 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4320 set_bit(STRIPE_HANDLE, &sh->state);
4322 first_sector += STRIPE_SECTORS;
4324 /* Now that the sources are clearly marked, we can release
4325 * the destination stripes
4327 while (!list_empty(&stripes)) {
4328 sh = list_entry(stripes.next, struct stripe_head, lru);
4329 list_del_init(&sh->lru);
4332 /* If this takes us to the resync_max point where we have to pause,
4333 * then we need to write out the superblock.
4335 sector_nr += reshape_sectors;
4336 if ((sector_nr - mddev->curr_resync_completed) * 2
4337 >= mddev->resync_max - mddev->curr_resync_completed) {
4338 /* Cannot proceed until we've updated the superblock... */
4339 wait_event(conf->wait_for_overlap,
4340 atomic_read(&conf->reshape_stripes) == 0);
4341 mddev->reshape_position = conf->reshape_progress;
4342 mddev->curr_resync_completed = mddev->curr_resync + reshape_sectors;
4343 conf->reshape_checkpoint = jiffies;
4344 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4345 md_wakeup_thread(mddev->thread);
4346 wait_event(mddev->sb_wait,
4347 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4348 || kthread_should_stop());
4349 spin_lock_irq(&conf->device_lock);
4350 conf->reshape_safe = mddev->reshape_position;
4351 spin_unlock_irq(&conf->device_lock);
4352 wake_up(&conf->wait_for_overlap);
4353 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4355 return reshape_sectors;
4358 /* FIXME go_faster isn't used */
4359 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
4361 raid5_conf_t *conf = mddev->private;
4362 struct stripe_head *sh;
4363 sector_t max_sector = mddev->dev_sectors;
4365 int still_degraded = 0;
4368 if (sector_nr >= max_sector) {
4369 /* just being told to finish up .. nothing much to do */
4370 unplug_slaves(mddev);
4372 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4377 if (mddev->curr_resync < max_sector) /* aborted */
4378 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4380 else /* completed sync */
4382 bitmap_close_sync(mddev->bitmap);
4387 /* Allow raid5_quiesce to complete */
4388 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4390 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4391 return reshape_request(mddev, sector_nr, skipped);
4393 /* No need to check resync_max as we never do more than one
4394 * stripe, and as resync_max will always be on a chunk boundary,
4395 * if the check in md_do_sync didn't fire, there is no chance
4396 * of overstepping resync_max here
4399 /* if there is too many failed drives and we are trying
4400 * to resync, then assert that we are finished, because there is
4401 * nothing we can do.
4403 if (mddev->degraded >= conf->max_degraded &&
4404 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4405 sector_t rv = mddev->dev_sectors - sector_nr;
4409 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
4410 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
4411 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4412 /* we can skip this block, and probably more */
4413 sync_blocks /= STRIPE_SECTORS;
4415 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4419 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4421 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
4423 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
4424 /* make sure we don't swamp the stripe cache if someone else
4425 * is trying to get access
4427 schedule_timeout_uninterruptible(1);
4429 /* Need to check if array will still be degraded after recovery/resync
4430 * We don't need to check the 'failed' flag as when that gets set,
4433 for (i = 0; i < conf->raid_disks; i++)
4434 if (conf->disks[i].rdev == NULL)
4437 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4439 spin_lock(&sh->lock);
4440 set_bit(STRIPE_SYNCING, &sh->state);
4441 clear_bit(STRIPE_INSYNC, &sh->state);
4442 spin_unlock(&sh->lock);
4447 return STRIPE_SECTORS;
4450 static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4452 /* We may not be able to submit a whole bio at once as there
4453 * may not be enough stripe_heads available.
4454 * We cannot pre-allocate enough stripe_heads as we may need
4455 * more than exist in the cache (if we allow ever large chunks).
4456 * So we do one stripe head at a time and record in
4457 * ->bi_hw_segments how many have been done.
4459 * We *know* that this entire raid_bio is in one chunk, so
4460 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4462 struct stripe_head *sh;
4464 sector_t sector, logical_sector, last_sector;
4469 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4470 sector = raid5_compute_sector(conf, logical_sector,
4472 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4474 for (; logical_sector < last_sector;
4475 logical_sector += STRIPE_SECTORS,
4476 sector += STRIPE_SECTORS,
4479 if (scnt < raid5_bi_hw_segments(raid_bio))
4480 /* already done this stripe */
4483 sh = get_active_stripe(conf, sector, 0, 1, 0);
4486 /* failed to get a stripe - must wait */
4487 raid5_set_bi_hw_segments(raid_bio, scnt);
4488 conf->retry_read_aligned = raid_bio;
4492 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
4493 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4495 raid5_set_bi_hw_segments(raid_bio, scnt);
4496 conf->retry_read_aligned = raid_bio;
4504 spin_lock_irq(&conf->device_lock);
4505 remaining = raid5_dec_bi_phys_segments(raid_bio);
4506 spin_unlock_irq(&conf->device_lock);
4508 bio_endio(raid_bio, 0);
4509 if (atomic_dec_and_test(&conf->active_aligned_reads))
4510 wake_up(&conf->wait_for_stripe);
4516 * This is our raid5 kernel thread.
4518 * We scan the hash table for stripes which can be handled now.
4519 * During the scan, completed stripes are saved for us by the interrupt
4520 * handler, so that they will not have to wait for our next wakeup.
4522 static void raid5d(mddev_t *mddev)
4524 struct stripe_head *sh;
4525 raid5_conf_t *conf = mddev->private;
4528 pr_debug("+++ raid5d active\n");
4530 md_check_recovery(mddev);
4533 spin_lock_irq(&conf->device_lock);
4537 if (conf->seq_flush != conf->seq_write) {
4538 int seq = conf->seq_flush;
4539 spin_unlock_irq(&conf->device_lock);
4540 bitmap_unplug(mddev->bitmap);
4541 spin_lock_irq(&conf->device_lock);
4542 conf->seq_write = seq;
4543 activate_bit_delay(conf);
4546 while ((bio = remove_bio_from_retry(conf))) {
4548 spin_unlock_irq(&conf->device_lock);
4549 ok = retry_aligned_read(conf, bio);
4550 spin_lock_irq(&conf->device_lock);
4556 sh = __get_priority_stripe(conf);
4560 spin_unlock_irq(&conf->device_lock);
4567 spin_lock_irq(&conf->device_lock);
4569 pr_debug("%d stripes handled\n", handled);
4571 spin_unlock_irq(&conf->device_lock);
4573 async_tx_issue_pending_all();
4574 unplug_slaves(mddev);
4576 pr_debug("--- raid5d inactive\n");
4580 raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
4582 raid5_conf_t *conf = mddev->private;
4584 return sprintf(page, "%d\n", conf->max_nr_stripes);
4590 raid5_set_cache_size(mddev_t *mddev, int size)
4592 raid5_conf_t *conf = mddev->private;
4595 if (size <= 16 || size > 32768)
4597 while (size < conf->max_nr_stripes) {
4598 if (drop_one_stripe(conf))
4599 conf->max_nr_stripes--;
4603 err = md_allow_write(mddev);
4606 while (size > conf->max_nr_stripes) {
4607 if (grow_one_stripe(conf))
4608 conf->max_nr_stripes++;
4613 EXPORT_SYMBOL(raid5_set_cache_size);
4616 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
4618 raid5_conf_t *conf = mddev->private;
4622 if (len >= PAGE_SIZE)
4627 if (strict_strtoul(page, 10, &new))
4629 err = raid5_set_cache_size(mddev, new);
4635 static struct md_sysfs_entry
4636 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4637 raid5_show_stripe_cache_size,
4638 raid5_store_stripe_cache_size);
4641 raid5_show_preread_threshold(mddev_t *mddev, char *page)
4643 raid5_conf_t *conf = mddev->private;
4645 return sprintf(page, "%d\n", conf->bypass_threshold);
4651 raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4653 raid5_conf_t *conf = mddev->private;
4655 if (len >= PAGE_SIZE)
4660 if (strict_strtoul(page, 10, &new))
4662 if (new > conf->max_nr_stripes)
4664 conf->bypass_threshold = new;
4668 static struct md_sysfs_entry
4669 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4671 raid5_show_preread_threshold,
4672 raid5_store_preread_threshold);
4675 stripe_cache_active_show(mddev_t *mddev, char *page)
4677 raid5_conf_t *conf = mddev->private;
4679 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4684 static struct md_sysfs_entry
4685 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
4687 static struct attribute *raid5_attrs[] = {
4688 &raid5_stripecache_size.attr,
4689 &raid5_stripecache_active.attr,
4690 &raid5_preread_bypass_threshold.attr,
4693 static struct attribute_group raid5_attrs_group = {
4695 .attrs = raid5_attrs,
4699 raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4701 raid5_conf_t *conf = mddev->private;
4704 sectors = mddev->dev_sectors;
4706 /* size is defined by the smallest of previous and new size */
4707 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
4709 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
4710 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
4711 return sectors * (raid_disks - conf->max_degraded);
4714 static void raid5_free_percpu(raid5_conf_t *conf)
4716 struct raid5_percpu *percpu;
4723 for_each_possible_cpu(cpu) {
4724 percpu = per_cpu_ptr(conf->percpu, cpu);
4725 safe_put_page(percpu->spare_page);
4726 kfree(percpu->scribble);
4728 #ifdef CONFIG_HOTPLUG_CPU
4729 unregister_cpu_notifier(&conf->cpu_notify);
4733 free_percpu(conf->percpu);
4736 static void free_conf(raid5_conf_t *conf)
4738 shrink_stripes(conf);
4739 raid5_free_percpu(conf);
4741 kfree(conf->stripe_hashtbl);
4745 #ifdef CONFIG_HOTPLUG_CPU
4746 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
4749 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify);
4750 long cpu = (long)hcpu;
4751 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
4754 case CPU_UP_PREPARE:
4755 case CPU_UP_PREPARE_FROZEN:
4756 if (conf->level == 6 && !percpu->spare_page)
4757 percpu->spare_page = alloc_page(GFP_KERNEL);
4758 if (!percpu->scribble)
4759 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4761 if (!percpu->scribble ||
4762 (conf->level == 6 && !percpu->spare_page)) {
4763 safe_put_page(percpu->spare_page);
4764 kfree(percpu->scribble);
4765 pr_err("%s: failed memory allocation for cpu%ld\n",
4767 return notifier_from_errno(-ENOMEM);
4771 case CPU_DEAD_FROZEN:
4772 safe_put_page(percpu->spare_page);
4773 kfree(percpu->scribble);
4774 percpu->spare_page = NULL;
4775 percpu->scribble = NULL;
4784 static int raid5_alloc_percpu(raid5_conf_t *conf)
4787 struct page *spare_page;
4788 struct raid5_percpu __percpu *allcpus;
4792 allcpus = alloc_percpu(struct raid5_percpu);
4795 conf->percpu = allcpus;
4799 for_each_present_cpu(cpu) {
4800 if (conf->level == 6) {
4801 spare_page = alloc_page(GFP_KERNEL);
4806 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
4808 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4813 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
4815 #ifdef CONFIG_HOTPLUG_CPU
4816 conf->cpu_notify.notifier_call = raid456_cpu_notify;
4817 conf->cpu_notify.priority = 0;
4819 err = register_cpu_notifier(&conf->cpu_notify);
4826 static raid5_conf_t *setup_conf(mddev_t *mddev)
4829 int raid_disk, memory, max_disks;
4831 struct disk_info *disk;
4833 if (mddev->new_level != 5
4834 && mddev->new_level != 4
4835 && mddev->new_level != 6) {
4836 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4837 mdname(mddev), mddev->new_level);
4838 return ERR_PTR(-EIO);
4840 if ((mddev->new_level == 5
4841 && !algorithm_valid_raid5(mddev->new_layout)) ||
4842 (mddev->new_level == 6
4843 && !algorithm_valid_raid6(mddev->new_layout))) {
4844 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
4845 mdname(mddev), mddev->new_layout);
4846 return ERR_PTR(-EIO);
4848 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
4849 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4850 mdname(mddev), mddev->raid_disks);
4851 return ERR_PTR(-EINVAL);
4854 if (!mddev->new_chunk_sectors ||
4855 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4856 !is_power_of_2(mddev->new_chunk_sectors)) {
4857 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
4858 mdname(mddev), mddev->new_chunk_sectors << 9);
4859 return ERR_PTR(-EINVAL);
4862 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4865 spin_lock_init(&conf->device_lock);
4866 init_waitqueue_head(&conf->wait_for_stripe);
4867 init_waitqueue_head(&conf->wait_for_overlap);
4868 INIT_LIST_HEAD(&conf->handle_list);
4869 INIT_LIST_HEAD(&conf->hold_list);
4870 INIT_LIST_HEAD(&conf->delayed_list);
4871 INIT_LIST_HEAD(&conf->bitmap_list);
4872 INIT_LIST_HEAD(&conf->inactive_list);
4873 atomic_set(&conf->active_stripes, 0);
4874 atomic_set(&conf->preread_active_stripes, 0);
4875 atomic_set(&conf->active_aligned_reads, 0);
4876 conf->bypass_threshold = BYPASS_THRESHOLD;
4878 conf->raid_disks = mddev->raid_disks;
4879 if (mddev->reshape_position == MaxSector)
4880 conf->previous_raid_disks = mddev->raid_disks;
4882 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4883 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
4884 conf->scribble_len = scribble_len(max_disks);
4886 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
4891 conf->mddev = mddev;
4893 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4896 conf->level = mddev->new_level;
4897 if (raid5_alloc_percpu(conf) != 0)
4900 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
4902 list_for_each_entry(rdev, &mddev->disks, same_set) {
4903 raid_disk = rdev->raid_disk;
4904 if (raid_disk >= max_disks
4907 disk = conf->disks + raid_disk;
4911 if (test_bit(In_sync, &rdev->flags)) {
4912 char b[BDEVNAME_SIZE];
4913 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
4915 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
4917 /* Cannot rely on bitmap to complete recovery */
4921 conf->chunk_sectors = mddev->new_chunk_sectors;
4922 conf->level = mddev->new_level;
4923 if (conf->level == 6)
4924 conf->max_degraded = 2;
4926 conf->max_degraded = 1;
4927 conf->algorithm = mddev->new_layout;
4928 conf->max_nr_stripes = NR_STRIPES;
4929 conf->reshape_progress = mddev->reshape_position;
4930 if (conf->reshape_progress != MaxSector) {
4931 conf->prev_chunk_sectors = mddev->chunk_sectors;
4932 conf->prev_algo = mddev->layout;
4935 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4936 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4937 if (grow_stripes(conf, conf->max_nr_stripes)) {
4939 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4940 mdname(mddev), memory);
4943 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
4944 mdname(mddev), memory);
4946 conf->thread = md_register_thread(raid5d, mddev, NULL);
4947 if (!conf->thread) {
4949 "md/raid:%s: couldn't allocate thread.\n",
4959 return ERR_PTR(-EIO);
4961 return ERR_PTR(-ENOMEM);
4965 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
4968 case ALGORITHM_PARITY_0:
4969 if (raid_disk < max_degraded)
4972 case ALGORITHM_PARITY_N:
4973 if (raid_disk >= raid_disks - max_degraded)
4976 case ALGORITHM_PARITY_0_6:
4977 if (raid_disk == 0 ||
4978 raid_disk == raid_disks - 1)
4981 case ALGORITHM_LEFT_ASYMMETRIC_6:
4982 case ALGORITHM_RIGHT_ASYMMETRIC_6:
4983 case ALGORITHM_LEFT_SYMMETRIC_6:
4984 case ALGORITHM_RIGHT_SYMMETRIC_6:
4985 if (raid_disk == raid_disks - 1)
4991 static int run(mddev_t *mddev)
4994 int working_disks = 0;
4995 int dirty_parity_disks = 0;
4997 sector_t reshape_offset = 0;
4999 if (mddev->recovery_cp != MaxSector)
5000 printk(KERN_NOTICE "md/raid:%s: not clean"
5001 " -- starting background reconstruction\n",
5003 if (mddev->reshape_position != MaxSector) {
5004 /* Check that we can continue the reshape.
5005 * Currently only disks can change, it must
5006 * increase, and we must be past the point where
5007 * a stripe over-writes itself
5009 sector_t here_new, here_old;
5011 int max_degraded = (mddev->level == 6 ? 2 : 1);
5013 if (mddev->new_level != mddev->level) {
5014 printk(KERN_ERR "md/raid:%s: unsupported reshape "
5015 "required - aborting.\n",
5019 old_disks = mddev->raid_disks - mddev->delta_disks;
5020 /* reshape_position must be on a new-stripe boundary, and one
5021 * further up in new geometry must map after here in old
5024 here_new = mddev->reshape_position;
5025 if (sector_div(here_new, mddev->new_chunk_sectors *
5026 (mddev->raid_disks - max_degraded))) {
5027 printk(KERN_ERR "md/raid:%s: reshape_position not "
5028 "on a stripe boundary\n", mdname(mddev));
5031 reshape_offset = here_new * mddev->new_chunk_sectors;
5032 /* here_new is the stripe we will write to */
5033 here_old = mddev->reshape_position;
5034 sector_div(here_old, mddev->chunk_sectors *
5035 (old_disks-max_degraded));
5036 /* here_old is the first stripe that we might need to read
5038 if (mddev->delta_disks == 0) {
5039 /* We cannot be sure it is safe to start an in-place
5040 * reshape. It is only safe if user-space if monitoring
5041 * and taking constant backups.
5042 * mdadm always starts a situation like this in
5043 * readonly mode so it can take control before
5044 * allowing any writes. So just check for that.
5046 if ((here_new * mddev->new_chunk_sectors !=
5047 here_old * mddev->chunk_sectors) ||
5049 printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
5050 " in read-only mode - aborting\n",
5054 } else if (mddev->delta_disks < 0
5055 ? (here_new * mddev->new_chunk_sectors <=
5056 here_old * mddev->chunk_sectors)
5057 : (here_new * mddev->new_chunk_sectors >=
5058 here_old * mddev->chunk_sectors)) {
5059 /* Reading from the same stripe as writing to - bad */
5060 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
5061 "auto-recovery - aborting.\n",
5065 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
5067 /* OK, we should be able to continue; */
5069 BUG_ON(mddev->level != mddev->new_level);
5070 BUG_ON(mddev->layout != mddev->new_layout);
5071 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
5072 BUG_ON(mddev->delta_disks != 0);
5075 if (mddev->private == NULL)
5076 conf = setup_conf(mddev);
5078 conf = mddev->private;
5081 return PTR_ERR(conf);
5083 mddev->thread = conf->thread;
5084 conf->thread = NULL;
5085 mddev->private = conf;
5088 * 0 for a fully functional array, 1 or 2 for a degraded array.
5090 list_for_each_entry(rdev, &mddev->disks, same_set) {
5091 if (rdev->raid_disk < 0)
5093 if (test_bit(In_sync, &rdev->flags)) {
5097 /* This disc is not fully in-sync. However if it
5098 * just stored parity (beyond the recovery_offset),
5099 * when we don't need to be concerned about the
5100 * array being dirty.
5101 * When reshape goes 'backwards', we never have
5102 * partially completed devices, so we only need
5103 * to worry about reshape going forwards.
5105 /* Hack because v0.91 doesn't store recovery_offset properly. */
5106 if (mddev->major_version == 0 &&
5107 mddev->minor_version > 90)
5108 rdev->recovery_offset = reshape_offset;
5110 if (rdev->recovery_offset < reshape_offset) {
5111 /* We need to check old and new layout */
5112 if (!only_parity(rdev->raid_disk,
5115 conf->max_degraded))
5118 if (!only_parity(rdev->raid_disk,
5120 conf->previous_raid_disks,
5121 conf->max_degraded))
5123 dirty_parity_disks++;
5126 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
5129 if (has_failed(conf)) {
5130 printk(KERN_ERR "md/raid:%s: not enough operational devices"
5131 " (%d/%d failed)\n",
5132 mdname(mddev), mddev->degraded, conf->raid_disks);
5136 /* device size must be a multiple of chunk size */
5137 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
5138 mddev->resync_max_sectors = mddev->dev_sectors;
5140 if (mddev->degraded > dirty_parity_disks &&
5141 mddev->recovery_cp != MaxSector) {
5142 if (mddev->ok_start_degraded)
5144 "md/raid:%s: starting dirty degraded array"
5145 " - data corruption possible.\n",
5149 "md/raid:%s: cannot start dirty degraded array.\n",
5155 if (mddev->degraded == 0)
5156 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5157 " devices, algorithm %d\n", mdname(mddev), conf->level,
5158 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5161 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5162 " out of %d devices, algorithm %d\n",
5163 mdname(mddev), conf->level,
5164 mddev->raid_disks - mddev->degraded,
5165 mddev->raid_disks, mddev->new_layout);
5167 print_raid5_conf(conf);
5169 if (conf->reshape_progress != MaxSector) {
5170 conf->reshape_safe = conf->reshape_progress;
5171 atomic_set(&conf->reshape_stripes, 0);
5172 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5173 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5174 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5175 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5176 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5181 /* Ok, everything is just fine now */
5182 if (mddev->to_remove == &raid5_attrs_group)
5183 mddev->to_remove = NULL;
5184 else if (mddev->kobj.sd &&
5185 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5187 "raid5: failed to create sysfs attributes for %s\n",
5189 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5191 plugger_init(&conf->plug, raid5_unplug);
5192 mddev->plug = &conf->plug;
5195 /* read-ahead size must cover two whole stripes, which
5196 * is 2 * (datadisks) * chunksize where 'n' is the
5197 * number of raid devices
5199 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5200 int stripe = data_disks *
5201 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
5202 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5203 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5205 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
5207 mddev->queue->backing_dev_info.congested_data = mddev;
5208 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
5209 mddev->queue->queue_lock = &conf->device_lock;
5210 mddev->queue->unplug_fn = raid5_unplug_queue;
5212 chunk_size = mddev->chunk_sectors << 9;
5213 blk_queue_io_min(mddev->queue, chunk_size);
5214 blk_queue_io_opt(mddev->queue, chunk_size *
5215 (conf->raid_disks - conf->max_degraded));
5217 list_for_each_entry(rdev, &mddev->disks, same_set)
5218 disk_stack_limits(mddev->gendisk, rdev->bdev,
5219 rdev->data_offset << 9);
5224 md_unregister_thread(mddev->thread);
5225 mddev->thread = NULL;
5227 print_raid5_conf(conf);
5230 mddev->private = NULL;
5231 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
5235 static int stop(mddev_t *mddev)
5237 raid5_conf_t *conf = mddev->private;
5239 md_unregister_thread(mddev->thread);
5240 mddev->thread = NULL;
5242 mddev->queue->backing_dev_info.congested_fn = NULL;
5243 plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/
5245 mddev->private = NULL;
5246 mddev->to_remove = &raid5_attrs_group;
5251 static void print_sh(struct seq_file *seq, struct stripe_head *sh)
5255 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
5256 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
5257 seq_printf(seq, "sh %llu, count %d.\n",
5258 (unsigned long long)sh->sector, atomic_read(&sh->count));
5259 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
5260 for (i = 0; i < sh->disks; i++) {
5261 seq_printf(seq, "(cache%d: %p %ld) ",
5262 i, sh->dev[i].page, sh->dev[i].flags);
5264 seq_printf(seq, "\n");
5267 static void printall(struct seq_file *seq, raid5_conf_t *conf)
5269 struct stripe_head *sh;
5270 struct hlist_node *hn;
5273 spin_lock_irq(&conf->device_lock);
5274 for (i = 0; i < NR_HASH; i++) {
5275 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
5276 if (sh->raid_conf != conf)
5281 spin_unlock_irq(&conf->device_lock);
5285 static void status(struct seq_file *seq, mddev_t *mddev)
5287 raid5_conf_t *conf = mddev->private;
5290 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5291 mddev->chunk_sectors / 2, mddev->layout);
5292 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
5293 for (i = 0; i < conf->raid_disks; i++)
5294 seq_printf (seq, "%s",
5295 conf->disks[i].rdev &&
5296 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
5297 seq_printf (seq, "]");
5299 seq_printf (seq, "\n");
5300 printall(seq, conf);
5304 static void print_raid5_conf (raid5_conf_t *conf)
5307 struct disk_info *tmp;
5309 printk(KERN_DEBUG "RAID conf printout:\n");
5311 printk("(conf==NULL)\n");
5314 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
5316 conf->raid_disks - conf->mddev->degraded);
5318 for (i = 0; i < conf->raid_disks; i++) {
5319 char b[BDEVNAME_SIZE];
5320 tmp = conf->disks + i;
5322 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
5323 i, !test_bit(Faulty, &tmp->rdev->flags),
5324 bdevname(tmp->rdev->bdev, b));
5328 static int raid5_spare_active(mddev_t *mddev)
5331 raid5_conf_t *conf = mddev->private;
5332 struct disk_info *tmp;
5334 for (i = 0; i < conf->raid_disks; i++) {
5335 tmp = conf->disks + i;
5337 && tmp->rdev->recovery_offset == MaxSector
5338 && !test_bit(Faulty, &tmp->rdev->flags)
5339 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
5340 unsigned long flags;
5341 spin_lock_irqsave(&conf->device_lock, flags);
5343 spin_unlock_irqrestore(&conf->device_lock, flags);
5346 print_raid5_conf(conf);
5350 static int raid5_remove_disk(mddev_t *mddev, int number)
5352 raid5_conf_t *conf = mddev->private;
5355 struct disk_info *p = conf->disks + number;
5357 print_raid5_conf(conf);
5360 if (number >= conf->raid_disks &&
5361 conf->reshape_progress == MaxSector)
5362 clear_bit(In_sync, &rdev->flags);
5364 if (test_bit(In_sync, &rdev->flags) ||
5365 atomic_read(&rdev->nr_pending)) {
5369 /* Only remove non-faulty devices if recovery
5372 if (!test_bit(Faulty, &rdev->flags) &&
5373 !has_failed(conf) &&
5374 number < conf->raid_disks) {
5380 if (atomic_read(&rdev->nr_pending)) {
5381 /* lost the race, try later */
5388 print_raid5_conf(conf);
5392 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
5394 raid5_conf_t *conf = mddev->private;
5397 struct disk_info *p;
5399 int last = conf->raid_disks - 1;
5401 if (has_failed(conf))
5402 /* no point adding a device */
5405 if (rdev->raid_disk >= 0)
5406 first = last = rdev->raid_disk;
5409 * find the disk ... but prefer rdev->saved_raid_disk
5412 if (rdev->saved_raid_disk >= 0 &&
5413 rdev->saved_raid_disk >= first &&
5414 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5415 disk = rdev->saved_raid_disk;
5418 for ( ; disk <= last ; disk++)
5419 if ((p=conf->disks + disk)->rdev == NULL) {
5420 clear_bit(In_sync, &rdev->flags);
5421 rdev->raid_disk = disk;
5423 if (rdev->saved_raid_disk != disk)
5425 rcu_assign_pointer(p->rdev, rdev);
5428 print_raid5_conf(conf);
5432 static int raid5_resize(mddev_t *mddev, sector_t sectors)
5434 /* no resync is happening, and there is enough space
5435 * on all devices, so we can resize.
5436 * We need to make sure resync covers any new space.
5437 * If the array is shrinking we should possibly wait until
5438 * any io in the removed space completes, but it hardly seems
5441 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
5442 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
5443 mddev->raid_disks));
5444 if (mddev->array_sectors >
5445 raid5_size(mddev, sectors, mddev->raid_disks))
5447 set_capacity(mddev->gendisk, mddev->array_sectors);
5448 revalidate_disk(mddev->gendisk);
5449 if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
5450 mddev->recovery_cp = mddev->dev_sectors;
5451 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5453 mddev->dev_sectors = sectors;
5454 mddev->resync_max_sectors = sectors;
5458 static int check_stripe_cache(mddev_t *mddev)
5460 /* Can only proceed if there are plenty of stripe_heads.
5461 * We need a minimum of one full stripe,, and for sensible progress
5462 * it is best to have about 4 times that.
5463 * If we require 4 times, then the default 256 4K stripe_heads will
5464 * allow for chunk sizes up to 256K, which is probably OK.
5465 * If the chunk size is greater, user-space should request more
5466 * stripe_heads first.
5468 raid5_conf_t *conf = mddev->private;
5469 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5470 > conf->max_nr_stripes ||
5471 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5472 > conf->max_nr_stripes) {
5473 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5475 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5482 static int check_reshape(mddev_t *mddev)
5484 raid5_conf_t *conf = mddev->private;
5486 if (mddev->delta_disks == 0 &&
5487 mddev->new_layout == mddev->layout &&
5488 mddev->new_chunk_sectors == mddev->chunk_sectors)
5489 return 0; /* nothing to do */
5491 /* Cannot grow a bitmap yet */
5493 if (has_failed(conf))
5495 if (mddev->delta_disks < 0) {
5496 /* We might be able to shrink, but the devices must
5497 * be made bigger first.
5498 * For raid6, 4 is the minimum size.
5499 * Otherwise 2 is the minimum
5502 if (mddev->level == 6)
5504 if (mddev->raid_disks + mddev->delta_disks < min)
5508 if (!check_stripe_cache(mddev))
5511 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
5514 static int raid5_start_reshape(mddev_t *mddev)
5516 raid5_conf_t *conf = mddev->private;
5519 int added_devices = 0;
5520 unsigned long flags;
5522 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5525 if (!check_stripe_cache(mddev))
5528 list_for_each_entry(rdev, &mddev->disks, same_set)
5529 if (rdev->raid_disk < 0 &&
5530 !test_bit(Faulty, &rdev->flags))
5533 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
5534 /* Not enough devices even to make a degraded array
5539 /* Refuse to reduce size of the array. Any reductions in
5540 * array size must be through explicit setting of array_size
5543 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5544 < mddev->array_sectors) {
5545 printk(KERN_ERR "md/raid:%s: array size must be reduced "
5546 "before number of disks\n", mdname(mddev));
5550 atomic_set(&conf->reshape_stripes, 0);
5551 spin_lock_irq(&conf->device_lock);
5552 conf->previous_raid_disks = conf->raid_disks;
5553 conf->raid_disks += mddev->delta_disks;
5554 conf->prev_chunk_sectors = conf->chunk_sectors;
5555 conf->chunk_sectors = mddev->new_chunk_sectors;
5556 conf->prev_algo = conf->algorithm;
5557 conf->algorithm = mddev->new_layout;
5558 if (mddev->delta_disks < 0)
5559 conf->reshape_progress = raid5_size(mddev, 0, 0);
5561 conf->reshape_progress = 0;
5562 conf->reshape_safe = conf->reshape_progress;
5564 spin_unlock_irq(&conf->device_lock);
5566 /* Add some new drives, as many as will fit.
5567 * We know there are enough to make the newly sized array work.
5568 * Don't add devices if we are reducing the number of
5569 * devices in the array. This is because it is not possible
5570 * to correctly record the "partially reconstructed" state of
5571 * such devices during the reshape and confusion could result.
5573 if (mddev->delta_disks >= 0)
5574 list_for_each_entry(rdev, &mddev->disks, same_set)
5575 if (rdev->raid_disk < 0 &&
5576 !test_bit(Faulty, &rdev->flags)) {
5577 if (raid5_add_disk(mddev, rdev) == 0) {
5579 if (rdev->raid_disk >= conf->previous_raid_disks) {
5580 set_bit(In_sync, &rdev->flags);
5583 rdev->recovery_offset = 0;
5584 sprintf(nm, "rd%d", rdev->raid_disk);
5585 if (sysfs_create_link(&mddev->kobj,
5587 /* Failure here is OK */;
5592 /* When a reshape changes the number of devices, ->degraded
5593 * is measured against the larger of the pre and post number of
5595 if (mddev->delta_disks > 0) {
5596 spin_lock_irqsave(&conf->device_lock, flags);
5597 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
5599 spin_unlock_irqrestore(&conf->device_lock, flags);
5601 mddev->raid_disks = conf->raid_disks;
5602 mddev->reshape_position = conf->reshape_progress;
5603 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5605 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5606 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5607 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5608 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5609 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5611 if (!mddev->sync_thread) {
5612 mddev->recovery = 0;
5613 spin_lock_irq(&conf->device_lock);
5614 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
5615 conf->reshape_progress = MaxSector;
5616 spin_unlock_irq(&conf->device_lock);
5619 conf->reshape_checkpoint = jiffies;
5620 md_wakeup_thread(mddev->sync_thread);
5621 md_new_event(mddev);
5625 /* This is called from the reshape thread and should make any
5626 * changes needed in 'conf'
5628 static void end_reshape(raid5_conf_t *conf)
5631 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
5633 spin_lock_irq(&conf->device_lock);
5634 conf->previous_raid_disks = conf->raid_disks;
5635 conf->reshape_progress = MaxSector;
5636 spin_unlock_irq(&conf->device_lock);
5637 wake_up(&conf->wait_for_overlap);
5639 /* read-ahead size must cover two whole stripes, which is
5640 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5642 if (conf->mddev->queue) {
5643 int data_disks = conf->raid_disks - conf->max_degraded;
5644 int stripe = data_disks * ((conf->chunk_sectors << 9)
5646 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5647 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5652 /* This is called from the raid5d thread with mddev_lock held.
5653 * It makes config changes to the device.
5655 static void raid5_finish_reshape(mddev_t *mddev)
5657 raid5_conf_t *conf = mddev->private;
5659 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5661 if (mddev->delta_disks > 0) {
5662 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5663 set_capacity(mddev->gendisk, mddev->array_sectors);
5664 revalidate_disk(mddev->gendisk);
5667 mddev->degraded = conf->raid_disks;
5668 for (d = 0; d < conf->raid_disks ; d++)
5669 if (conf->disks[d].rdev &&
5671 &conf->disks[d].rdev->flags))
5673 for (d = conf->raid_disks ;
5674 d < conf->raid_disks - mddev->delta_disks;
5676 mdk_rdev_t *rdev = conf->disks[d].rdev;
5677 if (rdev && raid5_remove_disk(mddev, d) == 0) {
5679 sprintf(nm, "rd%d", rdev->raid_disk);
5680 sysfs_remove_link(&mddev->kobj, nm);
5681 rdev->raid_disk = -1;
5685 mddev->layout = conf->algorithm;
5686 mddev->chunk_sectors = conf->chunk_sectors;
5687 mddev->reshape_position = MaxSector;
5688 mddev->delta_disks = 0;
5692 static void raid5_quiesce(mddev_t *mddev, int state)
5694 raid5_conf_t *conf = mddev->private;
5697 case 2: /* resume for a suspend */
5698 wake_up(&conf->wait_for_overlap);
5701 case 1: /* stop all writes */
5702 spin_lock_irq(&conf->device_lock);
5703 /* '2' tells resync/reshape to pause so that all
5704 * active stripes can drain
5707 wait_event_lock_irq(conf->wait_for_stripe,
5708 atomic_read(&conf->active_stripes) == 0 &&
5709 atomic_read(&conf->active_aligned_reads) == 0,
5710 conf->device_lock, /* nothing */);
5712 spin_unlock_irq(&conf->device_lock);
5713 /* allow reshape to continue */
5714 wake_up(&conf->wait_for_overlap);
5717 case 0: /* re-enable writes */
5718 spin_lock_irq(&conf->device_lock);
5720 wake_up(&conf->wait_for_stripe);
5721 wake_up(&conf->wait_for_overlap);
5722 spin_unlock_irq(&conf->device_lock);
5728 static void *raid45_takeover_raid0(mddev_t *mddev, int level)
5730 struct raid0_private_data *raid0_priv = mddev->private;
5732 /* for raid0 takeover only one zone is supported */
5733 if (raid0_priv->nr_strip_zones > 1) {
5734 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5736 return ERR_PTR(-EINVAL);
5739 mddev->new_level = level;
5740 mddev->new_layout = ALGORITHM_PARITY_N;
5741 mddev->new_chunk_sectors = mddev->chunk_sectors;
5742 mddev->raid_disks += 1;
5743 mddev->delta_disks = 1;
5744 /* make sure it will be not marked as dirty */
5745 mddev->recovery_cp = MaxSector;
5747 return setup_conf(mddev);
5751 static void *raid5_takeover_raid1(mddev_t *mddev)
5755 if (mddev->raid_disks != 2 ||
5756 mddev->degraded > 1)
5757 return ERR_PTR(-EINVAL);
5759 /* Should check if there are write-behind devices? */
5761 chunksect = 64*2; /* 64K by default */
5763 /* The array must be an exact multiple of chunksize */
5764 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5767 if ((chunksect<<9) < STRIPE_SIZE)
5768 /* array size does not allow a suitable chunk size */
5769 return ERR_PTR(-EINVAL);
5771 mddev->new_level = 5;
5772 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
5773 mddev->new_chunk_sectors = chunksect;
5775 return setup_conf(mddev);
5778 static void *raid5_takeover_raid6(mddev_t *mddev)
5782 switch (mddev->layout) {
5783 case ALGORITHM_LEFT_ASYMMETRIC_6:
5784 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5786 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5787 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5789 case ALGORITHM_LEFT_SYMMETRIC_6:
5790 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5792 case ALGORITHM_RIGHT_SYMMETRIC_6:
5793 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5795 case ALGORITHM_PARITY_0_6:
5796 new_layout = ALGORITHM_PARITY_0;
5798 case ALGORITHM_PARITY_N:
5799 new_layout = ALGORITHM_PARITY_N;
5802 return ERR_PTR(-EINVAL);
5804 mddev->new_level = 5;
5805 mddev->new_layout = new_layout;
5806 mddev->delta_disks = -1;
5807 mddev->raid_disks -= 1;
5808 return setup_conf(mddev);
5812 static int raid5_check_reshape(mddev_t *mddev)
5814 /* For a 2-drive array, the layout and chunk size can be changed
5815 * immediately as not restriping is needed.
5816 * For larger arrays we record the new value - after validation
5817 * to be used by a reshape pass.
5819 raid5_conf_t *conf = mddev->private;
5820 int new_chunk = mddev->new_chunk_sectors;
5822 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
5824 if (new_chunk > 0) {
5825 if (!is_power_of_2(new_chunk))
5827 if (new_chunk < (PAGE_SIZE>>9))
5829 if (mddev->array_sectors & (new_chunk-1))
5830 /* not factor of array size */
5834 /* They look valid */
5836 if (mddev->raid_disks == 2) {
5837 /* can make the change immediately */
5838 if (mddev->new_layout >= 0) {
5839 conf->algorithm = mddev->new_layout;
5840 mddev->layout = mddev->new_layout;
5842 if (new_chunk > 0) {
5843 conf->chunk_sectors = new_chunk ;
5844 mddev->chunk_sectors = new_chunk;
5846 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5847 md_wakeup_thread(mddev->thread);
5849 return check_reshape(mddev);
5852 static int raid6_check_reshape(mddev_t *mddev)
5854 int new_chunk = mddev->new_chunk_sectors;
5856 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
5858 if (new_chunk > 0) {
5859 if (!is_power_of_2(new_chunk))
5861 if (new_chunk < (PAGE_SIZE >> 9))
5863 if (mddev->array_sectors & (new_chunk-1))
5864 /* not factor of array size */
5868 /* They look valid */
5869 return check_reshape(mddev);
5872 static void *raid5_takeover(mddev_t *mddev)
5874 /* raid5 can take over:
5875 * raid0 - if there is only one strip zone - make it a raid4 layout
5876 * raid1 - if there are two drives. We need to know the chunk size
5877 * raid4 - trivial - just use a raid4 layout.
5878 * raid6 - Providing it is a *_6 layout
5880 if (mddev->level == 0)
5881 return raid45_takeover_raid0(mddev, 5);
5882 if (mddev->level == 1)
5883 return raid5_takeover_raid1(mddev);
5884 if (mddev->level == 4) {
5885 mddev->new_layout = ALGORITHM_PARITY_N;
5886 mddev->new_level = 5;
5887 return setup_conf(mddev);
5889 if (mddev->level == 6)
5890 return raid5_takeover_raid6(mddev);
5892 return ERR_PTR(-EINVAL);
5895 static void *raid4_takeover(mddev_t *mddev)
5897 /* raid4 can take over:
5898 * raid0 - if there is only one strip zone
5899 * raid5 - if layout is right
5901 if (mddev->level == 0)
5902 return raid45_takeover_raid0(mddev, 4);
5903 if (mddev->level == 5 &&
5904 mddev->layout == ALGORITHM_PARITY_N) {
5905 mddev->new_layout = 0;
5906 mddev->new_level = 4;
5907 return setup_conf(mddev);
5909 return ERR_PTR(-EINVAL);
5912 static struct mdk_personality raid5_personality;
5914 static void *raid6_takeover(mddev_t *mddev)
5916 /* Currently can only take over a raid5. We map the
5917 * personality to an equivalent raid6 personality
5918 * with the Q block at the end.
5922 if (mddev->pers != &raid5_personality)
5923 return ERR_PTR(-EINVAL);
5924 if (mddev->degraded > 1)
5925 return ERR_PTR(-EINVAL);
5926 if (mddev->raid_disks > 253)
5927 return ERR_PTR(-EINVAL);
5928 if (mddev->raid_disks < 3)
5929 return ERR_PTR(-EINVAL);
5931 switch (mddev->layout) {
5932 case ALGORITHM_LEFT_ASYMMETRIC:
5933 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5935 case ALGORITHM_RIGHT_ASYMMETRIC:
5936 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5938 case ALGORITHM_LEFT_SYMMETRIC:
5939 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5941 case ALGORITHM_RIGHT_SYMMETRIC:
5942 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5944 case ALGORITHM_PARITY_0:
5945 new_layout = ALGORITHM_PARITY_0_6;
5947 case ALGORITHM_PARITY_N:
5948 new_layout = ALGORITHM_PARITY_N;
5951 return ERR_PTR(-EINVAL);
5953 mddev->new_level = 6;
5954 mddev->new_layout = new_layout;
5955 mddev->delta_disks = 1;
5956 mddev->raid_disks += 1;
5957 return setup_conf(mddev);
5961 static struct mdk_personality raid6_personality =
5965 .owner = THIS_MODULE,
5966 .make_request = make_request,
5970 .error_handler = error,
5971 .hot_add_disk = raid5_add_disk,
5972 .hot_remove_disk= raid5_remove_disk,
5973 .spare_active = raid5_spare_active,
5974 .sync_request = sync_request,
5975 .resize = raid5_resize,
5977 .check_reshape = raid6_check_reshape,
5978 .start_reshape = raid5_start_reshape,
5979 .finish_reshape = raid5_finish_reshape,
5980 .quiesce = raid5_quiesce,
5981 .takeover = raid6_takeover,
5983 static struct mdk_personality raid5_personality =
5987 .owner = THIS_MODULE,
5988 .make_request = make_request,
5992 .error_handler = error,
5993 .hot_add_disk = raid5_add_disk,
5994 .hot_remove_disk= raid5_remove_disk,
5995 .spare_active = raid5_spare_active,
5996 .sync_request = sync_request,
5997 .resize = raid5_resize,
5999 .check_reshape = raid5_check_reshape,
6000 .start_reshape = raid5_start_reshape,
6001 .finish_reshape = raid5_finish_reshape,
6002 .quiesce = raid5_quiesce,
6003 .takeover = raid5_takeover,
6006 static struct mdk_personality raid4_personality =
6010 .owner = THIS_MODULE,
6011 .make_request = make_request,
6015 .error_handler = error,
6016 .hot_add_disk = raid5_add_disk,
6017 .hot_remove_disk= raid5_remove_disk,
6018 .spare_active = raid5_spare_active,
6019 .sync_request = sync_request,
6020 .resize = raid5_resize,
6022 .check_reshape = raid5_check_reshape,
6023 .start_reshape = raid5_start_reshape,
6024 .finish_reshape = raid5_finish_reshape,
6025 .quiesce = raid5_quiesce,
6026 .takeover = raid4_takeover,
6029 static int __init raid5_init(void)
6031 register_md_personality(&raid6_personality);
6032 register_md_personality(&raid5_personality);
6033 register_md_personality(&raid4_personality);
6037 static void raid5_exit(void)
6039 unregister_md_personality(&raid6_personality);
6040 unregister_md_personality(&raid5_personality);
6041 unregister_md_personality(&raid4_personality);
6044 module_init(raid5_init);
6045 module_exit(raid5_exit);
6046 MODULE_LICENSE("GPL");
6047 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6048 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6049 MODULE_ALIAS("md-raid5");
6050 MODULE_ALIAS("md-raid4");
6051 MODULE_ALIAS("md-level-5");
6052 MODULE_ALIAS("md-level-4");
6053 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6054 MODULE_ALIAS("md-raid6");
6055 MODULE_ALIAS("md-level-6");
6057 /* This used to be two separate modules, they were: */
6058 MODULE_ALIAS("raid5");
6059 MODULE_ALIAS("raid6");