2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is seq_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/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 else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
205 sh->bm_seq - conf->seq_write > 0)
206 list_add_tail(&sh->lru, &conf->bitmap_list);
208 clear_bit(STRIPE_BIT_DELAY, &sh->state);
209 list_add_tail(&sh->lru, &conf->handle_list);
211 md_wakeup_thread(conf->mddev->thread);
213 BUG_ON(stripe_operations_active(sh));
214 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
215 atomic_dec(&conf->preread_active_stripes);
216 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
217 md_wakeup_thread(conf->mddev->thread);
219 atomic_dec(&conf->active_stripes);
220 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
221 list_add_tail(&sh->lru, &conf->inactive_list);
222 wake_up(&conf->wait_for_stripe);
223 if (conf->retry_read_aligned)
224 md_wakeup_thread(conf->mddev->thread);
230 static void release_stripe(struct stripe_head *sh)
232 raid5_conf_t *conf = sh->raid_conf;
235 spin_lock_irqsave(&conf->device_lock, flags);
236 __release_stripe(conf, sh);
237 spin_unlock_irqrestore(&conf->device_lock, flags);
240 static inline void remove_hash(struct stripe_head *sh)
242 pr_debug("remove_hash(), stripe %llu\n",
243 (unsigned long long)sh->sector);
245 hlist_del_init(&sh->hash);
248 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
250 struct hlist_head *hp = stripe_hash(conf, sh->sector);
252 pr_debug("insert_hash(), stripe %llu\n",
253 (unsigned long long)sh->sector);
256 hlist_add_head(&sh->hash, hp);
260 /* find an idle stripe, make sure it is unhashed, and return it. */
261 static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
263 struct stripe_head *sh = NULL;
264 struct list_head *first;
267 if (list_empty(&conf->inactive_list))
269 first = conf->inactive_list.next;
270 sh = list_entry(first, struct stripe_head, lru);
271 list_del_init(first);
273 atomic_inc(&conf->active_stripes);
278 static void shrink_buffers(struct stripe_head *sh)
282 int num = sh->raid_conf->pool_size;
284 for (i = 0; i < num ; i++) {
288 sh->dev[i].page = NULL;
293 static int grow_buffers(struct stripe_head *sh)
296 int num = sh->raid_conf->pool_size;
298 for (i = 0; i < num; i++) {
301 if (!(page = alloc_page(GFP_KERNEL))) {
304 sh->dev[i].page = page;
309 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
310 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
311 struct stripe_head *sh);
313 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
315 raid5_conf_t *conf = sh->raid_conf;
318 BUG_ON(atomic_read(&sh->count) != 0);
319 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
320 BUG_ON(stripe_operations_active(sh));
323 pr_debug("init_stripe called, stripe %llu\n",
324 (unsigned long long)sh->sector);
328 sh->generation = conf->generation - previous;
329 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
331 stripe_set_idx(sector, conf, previous, sh);
335 for (i = sh->disks; i--; ) {
336 struct r5dev *dev = &sh->dev[i];
338 if (dev->toread || dev->read || dev->towrite || dev->written ||
339 test_bit(R5_LOCKED, &dev->flags)) {
340 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
341 (unsigned long long)sh->sector, i, dev->toread,
342 dev->read, dev->towrite, dev->written,
343 test_bit(R5_LOCKED, &dev->flags));
347 raid5_build_block(sh, i, previous);
349 insert_hash(conf, sh);
352 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
355 struct stripe_head *sh;
356 struct hlist_node *hn;
359 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
360 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
361 if (sh->sector == sector && sh->generation == generation)
363 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
368 * Need to check if array has failed when deciding whether to:
370 * - remove non-faulty devices
373 * This determination is simple when no reshape is happening.
374 * However if there is a reshape, we need to carefully check
375 * both the before and after sections.
376 * This is because some failed devices may only affect one
377 * of the two sections, and some non-in_sync devices may
378 * be insync in the section most affected by failed devices.
380 static int has_failed(raid5_conf_t *conf)
384 if (conf->mddev->reshape_position == MaxSector)
385 return conf->mddev->degraded > conf->max_degraded;
389 for (i = 0; i < conf->previous_raid_disks; i++) {
390 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
391 if (!rdev || test_bit(Faulty, &rdev->flags))
393 else if (test_bit(In_sync, &rdev->flags))
396 /* not in-sync or faulty.
397 * If the reshape increases the number of devices,
398 * this is being recovered by the reshape, so
399 * this 'previous' section is not in_sync.
400 * If the number of devices is being reduced however,
401 * the device can only be part of the array if
402 * we are reverting a reshape, so this section will
405 if (conf->raid_disks >= conf->previous_raid_disks)
409 if (degraded > conf->max_degraded)
413 for (i = 0; i < conf->raid_disks; i++) {
414 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
415 if (!rdev || test_bit(Faulty, &rdev->flags))
417 else if (test_bit(In_sync, &rdev->flags))
420 /* not in-sync or faulty.
421 * If reshape increases the number of devices, this
422 * section has already been recovered, else it
423 * almost certainly hasn't.
425 if (conf->raid_disks <= conf->previous_raid_disks)
429 if (degraded > conf->max_degraded)
434 static struct stripe_head *
435 get_active_stripe(raid5_conf_t *conf, sector_t sector,
436 int previous, int noblock, int noquiesce)
438 struct stripe_head *sh;
440 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
442 spin_lock_irq(&conf->device_lock);
445 wait_event_lock_irq(conf->wait_for_stripe,
446 conf->quiesce == 0 || noquiesce,
447 conf->device_lock, /* nothing */);
448 sh = __find_stripe(conf, sector, conf->generation - previous);
450 if (!conf->inactive_blocked)
451 sh = get_free_stripe(conf);
452 if (noblock && sh == NULL)
455 conf->inactive_blocked = 1;
456 wait_event_lock_irq(conf->wait_for_stripe,
457 !list_empty(&conf->inactive_list) &&
458 (atomic_read(&conf->active_stripes)
459 < (conf->max_nr_stripes *3/4)
460 || !conf->inactive_blocked),
463 conf->inactive_blocked = 0;
465 init_stripe(sh, sector, previous);
467 if (atomic_read(&sh->count)) {
468 BUG_ON(!list_empty(&sh->lru)
469 && !test_bit(STRIPE_EXPANDING, &sh->state));
471 if (!test_bit(STRIPE_HANDLE, &sh->state))
472 atomic_inc(&conf->active_stripes);
473 if (list_empty(&sh->lru) &&
474 !test_bit(STRIPE_EXPANDING, &sh->state))
476 list_del_init(&sh->lru);
479 } while (sh == NULL);
482 atomic_inc(&sh->count);
484 spin_unlock_irq(&conf->device_lock);
489 raid5_end_read_request(struct bio *bi, int error);
491 raid5_end_write_request(struct bio *bi, int error);
493 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
495 raid5_conf_t *conf = sh->raid_conf;
496 int i, disks = sh->disks;
500 for (i = disks; i--; ) {
504 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
505 if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
509 } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
514 bi = &sh->dev[i].req;
518 bi->bi_end_io = raid5_end_write_request;
520 bi->bi_end_io = raid5_end_read_request;
523 rdev = rcu_dereference(conf->disks[i].rdev);
524 if (rdev && test_bit(Faulty, &rdev->flags))
527 atomic_inc(&rdev->nr_pending);
531 if (s->syncing || s->expanding || s->expanded)
532 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
534 set_bit(STRIPE_IO_STARTED, &sh->state);
536 bi->bi_bdev = rdev->bdev;
537 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
538 __func__, (unsigned long long)sh->sector,
540 atomic_inc(&sh->count);
541 bi->bi_sector = sh->sector + rdev->data_offset;
542 bi->bi_flags = 1 << BIO_UPTODATE;
546 bi->bi_io_vec = &sh->dev[i].vec;
547 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
548 bi->bi_io_vec[0].bv_offset = 0;
549 bi->bi_size = STRIPE_SIZE;
552 test_bit(R5_ReWrite, &sh->dev[i].flags))
553 atomic_add(STRIPE_SECTORS,
554 &rdev->corrected_errors);
555 generic_make_request(bi);
558 set_bit(STRIPE_DEGRADED, &sh->state);
559 pr_debug("skip op %ld on disc %d for sector %llu\n",
560 bi->bi_rw, i, (unsigned long long)sh->sector);
561 clear_bit(R5_LOCKED, &sh->dev[i].flags);
562 set_bit(STRIPE_HANDLE, &sh->state);
567 static struct dma_async_tx_descriptor *
568 async_copy_data(int frombio, struct bio *bio, struct page *page,
569 sector_t sector, struct dma_async_tx_descriptor *tx)
572 struct page *bio_page;
575 struct async_submit_ctl submit;
576 enum async_tx_flags flags = 0;
578 if (bio->bi_sector >= sector)
579 page_offset = (signed)(bio->bi_sector - sector) * 512;
581 page_offset = (signed)(sector - bio->bi_sector) * -512;
584 flags |= ASYNC_TX_FENCE;
585 init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
587 bio_for_each_segment(bvl, bio, i) {
588 int len = bvl->bv_len;
592 if (page_offset < 0) {
593 b_offset = -page_offset;
594 page_offset += b_offset;
598 if (len > 0 && page_offset + len > STRIPE_SIZE)
599 clen = STRIPE_SIZE - page_offset;
604 b_offset += bvl->bv_offset;
605 bio_page = bvl->bv_page;
607 tx = async_memcpy(page, bio_page, page_offset,
608 b_offset, clen, &submit);
610 tx = async_memcpy(bio_page, page, b_offset,
611 page_offset, clen, &submit);
613 /* chain the operations */
614 submit.depend_tx = tx;
616 if (clen < len) /* hit end of page */
624 static void ops_complete_biofill(void *stripe_head_ref)
626 struct stripe_head *sh = stripe_head_ref;
627 struct bio *return_bi = NULL;
628 raid5_conf_t *conf = sh->raid_conf;
631 pr_debug("%s: stripe %llu\n", __func__,
632 (unsigned long long)sh->sector);
634 /* clear completed biofills */
635 spin_lock_irq(&conf->device_lock);
636 for (i = sh->disks; i--; ) {
637 struct r5dev *dev = &sh->dev[i];
639 /* acknowledge completion of a biofill operation */
640 /* and check if we need to reply to a read request,
641 * new R5_Wantfill requests are held off until
642 * !STRIPE_BIOFILL_RUN
644 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
645 struct bio *rbi, *rbi2;
650 while (rbi && rbi->bi_sector <
651 dev->sector + STRIPE_SECTORS) {
652 rbi2 = r5_next_bio(rbi, dev->sector);
653 if (!raid5_dec_bi_phys_segments(rbi)) {
654 rbi->bi_next = return_bi;
661 spin_unlock_irq(&conf->device_lock);
662 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
664 return_io(return_bi);
666 set_bit(STRIPE_HANDLE, &sh->state);
670 static void ops_run_biofill(struct stripe_head *sh)
672 struct dma_async_tx_descriptor *tx = NULL;
673 raid5_conf_t *conf = sh->raid_conf;
674 struct async_submit_ctl submit;
677 pr_debug("%s: stripe %llu\n", __func__,
678 (unsigned long long)sh->sector);
680 for (i = sh->disks; i--; ) {
681 struct r5dev *dev = &sh->dev[i];
682 if (test_bit(R5_Wantfill, &dev->flags)) {
684 spin_lock_irq(&conf->device_lock);
685 dev->read = rbi = dev->toread;
687 spin_unlock_irq(&conf->device_lock);
688 while (rbi && rbi->bi_sector <
689 dev->sector + STRIPE_SECTORS) {
690 tx = async_copy_data(0, rbi, dev->page,
692 rbi = r5_next_bio(rbi, dev->sector);
697 atomic_inc(&sh->count);
698 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
699 async_trigger_callback(&submit);
702 static void mark_target_uptodate(struct stripe_head *sh, int target)
709 tgt = &sh->dev[target];
710 set_bit(R5_UPTODATE, &tgt->flags);
711 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
712 clear_bit(R5_Wantcompute, &tgt->flags);
715 static void ops_complete_compute(void *stripe_head_ref)
717 struct stripe_head *sh = stripe_head_ref;
719 pr_debug("%s: stripe %llu\n", __func__,
720 (unsigned long long)sh->sector);
722 /* mark the computed target(s) as uptodate */
723 mark_target_uptodate(sh, sh->ops.target);
724 mark_target_uptodate(sh, sh->ops.target2);
726 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
727 if (sh->check_state == check_state_compute_run)
728 sh->check_state = check_state_compute_result;
729 set_bit(STRIPE_HANDLE, &sh->state);
733 /* return a pointer to the address conversion region of the scribble buffer */
734 static addr_conv_t *to_addr_conv(struct stripe_head *sh,
735 struct raid5_percpu *percpu)
737 return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
740 static struct dma_async_tx_descriptor *
741 ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
743 int disks = sh->disks;
744 struct page **xor_srcs = percpu->scribble;
745 int target = sh->ops.target;
746 struct r5dev *tgt = &sh->dev[target];
747 struct page *xor_dest = tgt->page;
749 struct dma_async_tx_descriptor *tx;
750 struct async_submit_ctl submit;
753 pr_debug("%s: stripe %llu block: %d\n",
754 __func__, (unsigned long long)sh->sector, target);
755 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
757 for (i = disks; i--; )
759 xor_srcs[count++] = sh->dev[i].page;
761 atomic_inc(&sh->count);
763 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
764 ops_complete_compute, sh, to_addr_conv(sh, percpu));
765 if (unlikely(count == 1))
766 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
768 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
773 /* set_syndrome_sources - populate source buffers for gen_syndrome
774 * @srcs - (struct page *) array of size sh->disks
775 * @sh - stripe_head to parse
777 * Populates srcs in proper layout order for the stripe and returns the
778 * 'count' of sources to be used in a call to async_gen_syndrome. The P
779 * destination buffer is recorded in srcs[count] and the Q destination
780 * is recorded in srcs[count+1]].
782 static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
784 int disks = sh->disks;
785 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
786 int d0_idx = raid6_d0(sh);
790 for (i = 0; i < disks; i++)
796 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
798 srcs[slot] = sh->dev[i].page;
799 i = raid6_next_disk(i, disks);
800 } while (i != d0_idx);
802 return syndrome_disks;
805 static struct dma_async_tx_descriptor *
806 ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
808 int disks = sh->disks;
809 struct page **blocks = percpu->scribble;
811 int qd_idx = sh->qd_idx;
812 struct dma_async_tx_descriptor *tx;
813 struct async_submit_ctl submit;
819 if (sh->ops.target < 0)
820 target = sh->ops.target2;
821 else if (sh->ops.target2 < 0)
822 target = sh->ops.target;
824 /* we should only have one valid target */
827 pr_debug("%s: stripe %llu block: %d\n",
828 __func__, (unsigned long long)sh->sector, target);
830 tgt = &sh->dev[target];
831 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
834 atomic_inc(&sh->count);
836 if (target == qd_idx) {
837 count = set_syndrome_sources(blocks, sh);
838 blocks[count] = NULL; /* regenerating p is not necessary */
839 BUG_ON(blocks[count+1] != dest); /* q should already be set */
840 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
841 ops_complete_compute, sh,
842 to_addr_conv(sh, percpu));
843 tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
845 /* Compute any data- or p-drive using XOR */
847 for (i = disks; i-- ; ) {
848 if (i == target || i == qd_idx)
850 blocks[count++] = sh->dev[i].page;
853 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
854 NULL, ops_complete_compute, sh,
855 to_addr_conv(sh, percpu));
856 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
862 static struct dma_async_tx_descriptor *
863 ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
865 int i, count, disks = sh->disks;
866 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
867 int d0_idx = raid6_d0(sh);
868 int faila = -1, failb = -1;
869 int target = sh->ops.target;
870 int target2 = sh->ops.target2;
871 struct r5dev *tgt = &sh->dev[target];
872 struct r5dev *tgt2 = &sh->dev[target2];
873 struct dma_async_tx_descriptor *tx;
874 struct page **blocks = percpu->scribble;
875 struct async_submit_ctl submit;
877 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
878 __func__, (unsigned long long)sh->sector, target, target2);
879 BUG_ON(target < 0 || target2 < 0);
880 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
881 BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
883 /* we need to open-code set_syndrome_sources to handle the
884 * slot number conversion for 'faila' and 'failb'
886 for (i = 0; i < disks ; i++)
891 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
893 blocks[slot] = sh->dev[i].page;
899 i = raid6_next_disk(i, disks);
900 } while (i != d0_idx);
902 BUG_ON(faila == failb);
905 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
906 __func__, (unsigned long long)sh->sector, faila, failb);
908 atomic_inc(&sh->count);
910 if (failb == syndrome_disks+1) {
911 /* Q disk is one of the missing disks */
912 if (faila == syndrome_disks) {
913 /* Missing P+Q, just recompute */
914 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
915 ops_complete_compute, sh,
916 to_addr_conv(sh, percpu));
917 return async_gen_syndrome(blocks, 0, syndrome_disks+2,
918 STRIPE_SIZE, &submit);
922 int qd_idx = sh->qd_idx;
924 /* Missing D+Q: recompute D from P, then recompute Q */
925 if (target == qd_idx)
926 data_target = target2;
928 data_target = target;
931 for (i = disks; i-- ; ) {
932 if (i == data_target || i == qd_idx)
934 blocks[count++] = sh->dev[i].page;
936 dest = sh->dev[data_target].page;
937 init_async_submit(&submit,
938 ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
940 to_addr_conv(sh, percpu));
941 tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
944 count = set_syndrome_sources(blocks, sh);
945 init_async_submit(&submit, ASYNC_TX_FENCE, tx,
946 ops_complete_compute, sh,
947 to_addr_conv(sh, percpu));
948 return async_gen_syndrome(blocks, 0, count+2,
949 STRIPE_SIZE, &submit);
952 init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
953 ops_complete_compute, sh,
954 to_addr_conv(sh, percpu));
955 if (failb == syndrome_disks) {
956 /* We're missing D+P. */
957 return async_raid6_datap_recov(syndrome_disks+2,
961 /* We're missing D+D. */
962 return async_raid6_2data_recov(syndrome_disks+2,
963 STRIPE_SIZE, faila, failb,
970 static void ops_complete_prexor(void *stripe_head_ref)
972 struct stripe_head *sh = stripe_head_ref;
974 pr_debug("%s: stripe %llu\n", __func__,
975 (unsigned long long)sh->sector);
978 static struct dma_async_tx_descriptor *
979 ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
980 struct dma_async_tx_descriptor *tx)
982 int disks = sh->disks;
983 struct page **xor_srcs = percpu->scribble;
984 int count = 0, pd_idx = sh->pd_idx, i;
985 struct async_submit_ctl submit;
987 /* existing parity data subtracted */
988 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
990 pr_debug("%s: stripe %llu\n", __func__,
991 (unsigned long long)sh->sector);
993 for (i = disks; i--; ) {
994 struct r5dev *dev = &sh->dev[i];
995 /* Only process blocks that are known to be uptodate */
996 if (test_bit(R5_Wantdrain, &dev->flags))
997 xor_srcs[count++] = dev->page;
1000 init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
1001 ops_complete_prexor, sh, to_addr_conv(sh, percpu));
1002 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1007 static struct dma_async_tx_descriptor *
1008 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
1010 int disks = sh->disks;
1013 pr_debug("%s: stripe %llu\n", __func__,
1014 (unsigned long long)sh->sector);
1016 for (i = disks; i--; ) {
1017 struct r5dev *dev = &sh->dev[i];
1020 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
1023 spin_lock(&sh->lock);
1024 spin_lock_irq(&sh->raid_conf->device_lock);
1025 chosen = dev->towrite;
1026 dev->towrite = NULL;
1027 BUG_ON(dev->written);
1028 wbi = dev->written = chosen;
1029 spin_unlock_irq(&sh->raid_conf->device_lock);
1030 spin_unlock(&sh->lock);
1032 while (wbi && wbi->bi_sector <
1033 dev->sector + STRIPE_SECTORS) {
1034 if (wbi->bi_rw & REQ_FUA)
1035 set_bit(R5_WantFUA, &dev->flags);
1036 tx = async_copy_data(1, wbi, dev->page,
1038 wbi = r5_next_bio(wbi, dev->sector);
1046 static void ops_complete_reconstruct(void *stripe_head_ref)
1048 struct stripe_head *sh = stripe_head_ref;
1049 int disks = sh->disks;
1050 int pd_idx = sh->pd_idx;
1051 int qd_idx = sh->qd_idx;
1055 pr_debug("%s: stripe %llu\n", __func__,
1056 (unsigned long long)sh->sector);
1058 for (i = disks; i--; )
1059 fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
1061 for (i = disks; i--; ) {
1062 struct r5dev *dev = &sh->dev[i];
1064 if (dev->written || i == pd_idx || i == qd_idx) {
1065 set_bit(R5_UPTODATE, &dev->flags);
1067 set_bit(R5_WantFUA, &dev->flags);
1071 if (sh->reconstruct_state == reconstruct_state_drain_run)
1072 sh->reconstruct_state = reconstruct_state_drain_result;
1073 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
1074 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
1076 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
1077 sh->reconstruct_state = reconstruct_state_result;
1080 set_bit(STRIPE_HANDLE, &sh->state);
1085 ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
1086 struct dma_async_tx_descriptor *tx)
1088 int disks = sh->disks;
1089 struct page **xor_srcs = percpu->scribble;
1090 struct async_submit_ctl submit;
1091 int count = 0, pd_idx = sh->pd_idx, i;
1092 struct page *xor_dest;
1094 unsigned long flags;
1096 pr_debug("%s: stripe %llu\n", __func__,
1097 (unsigned long long)sh->sector);
1099 /* check if prexor is active which means only process blocks
1100 * that are part of a read-modify-write (written)
1102 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
1104 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
1105 for (i = disks; i--; ) {
1106 struct r5dev *dev = &sh->dev[i];
1108 xor_srcs[count++] = dev->page;
1111 xor_dest = sh->dev[pd_idx].page;
1112 for (i = disks; i--; ) {
1113 struct r5dev *dev = &sh->dev[i];
1115 xor_srcs[count++] = dev->page;
1119 /* 1/ if we prexor'd then the dest is reused as a source
1120 * 2/ if we did not prexor then we are redoing the parity
1121 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1122 * for the synchronous xor case
1124 flags = ASYNC_TX_ACK |
1125 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
1127 atomic_inc(&sh->count);
1129 init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
1130 to_addr_conv(sh, percpu));
1131 if (unlikely(count == 1))
1132 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
1134 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
1138 ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
1139 struct dma_async_tx_descriptor *tx)
1141 struct async_submit_ctl submit;
1142 struct page **blocks = percpu->scribble;
1145 pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
1147 count = set_syndrome_sources(blocks, sh);
1149 atomic_inc(&sh->count);
1151 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
1152 sh, to_addr_conv(sh, percpu));
1153 async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
1156 static void ops_complete_check(void *stripe_head_ref)
1158 struct stripe_head *sh = stripe_head_ref;
1160 pr_debug("%s: stripe %llu\n", __func__,
1161 (unsigned long long)sh->sector);
1163 sh->check_state = check_state_check_result;
1164 set_bit(STRIPE_HANDLE, &sh->state);
1168 static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
1170 int disks = sh->disks;
1171 int pd_idx = sh->pd_idx;
1172 int qd_idx = sh->qd_idx;
1173 struct page *xor_dest;
1174 struct page **xor_srcs = percpu->scribble;
1175 struct dma_async_tx_descriptor *tx;
1176 struct async_submit_ctl submit;
1180 pr_debug("%s: stripe %llu\n", __func__,
1181 (unsigned long long)sh->sector);
1184 xor_dest = sh->dev[pd_idx].page;
1185 xor_srcs[count++] = xor_dest;
1186 for (i = disks; i--; ) {
1187 if (i == pd_idx || i == qd_idx)
1189 xor_srcs[count++] = sh->dev[i].page;
1192 init_async_submit(&submit, 0, NULL, NULL, NULL,
1193 to_addr_conv(sh, percpu));
1194 tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
1195 &sh->ops.zero_sum_result, &submit);
1197 atomic_inc(&sh->count);
1198 init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
1199 tx = async_trigger_callback(&submit);
1202 static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
1204 struct page **srcs = percpu->scribble;
1205 struct async_submit_ctl submit;
1208 pr_debug("%s: stripe %llu checkp: %d\n", __func__,
1209 (unsigned long long)sh->sector, checkp);
1211 count = set_syndrome_sources(srcs, sh);
1215 atomic_inc(&sh->count);
1216 init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
1217 sh, to_addr_conv(sh, percpu));
1218 async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
1219 &sh->ops.zero_sum_result, percpu->spare_page, &submit);
1222 static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1224 int overlap_clear = 0, i, disks = sh->disks;
1225 struct dma_async_tx_descriptor *tx = NULL;
1226 raid5_conf_t *conf = sh->raid_conf;
1227 int level = conf->level;
1228 struct raid5_percpu *percpu;
1232 percpu = per_cpu_ptr(conf->percpu, cpu);
1233 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
1234 ops_run_biofill(sh);
1238 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
1240 tx = ops_run_compute5(sh, percpu);
1242 if (sh->ops.target2 < 0 || sh->ops.target < 0)
1243 tx = ops_run_compute6_1(sh, percpu);
1245 tx = ops_run_compute6_2(sh, percpu);
1247 /* terminate the chain if reconstruct is not set to be run */
1248 if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
1252 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
1253 tx = ops_run_prexor(sh, percpu, tx);
1255 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
1256 tx = ops_run_biodrain(sh, tx);
1260 if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
1262 ops_run_reconstruct5(sh, percpu, tx);
1264 ops_run_reconstruct6(sh, percpu, tx);
1267 if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
1268 if (sh->check_state == check_state_run)
1269 ops_run_check_p(sh, percpu);
1270 else if (sh->check_state == check_state_run_q)
1271 ops_run_check_pq(sh, percpu, 0);
1272 else if (sh->check_state == check_state_run_pq)
1273 ops_run_check_pq(sh, percpu, 1);
1279 for (i = disks; i--; ) {
1280 struct r5dev *dev = &sh->dev[i];
1281 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1282 wake_up(&sh->raid_conf->wait_for_overlap);
1287 #ifdef CONFIG_MULTICORE_RAID456
1288 static void async_run_ops(void *param, async_cookie_t cookie)
1290 struct stripe_head *sh = param;
1291 unsigned long ops_request = sh->ops.request;
1293 clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
1294 wake_up(&sh->ops.wait_for_ops);
1296 __raid_run_ops(sh, ops_request);
1300 static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
1302 /* since handle_stripe can be called outside of raid5d context
1303 * we need to ensure sh->ops.request is de-staged before another
1306 wait_event(sh->ops.wait_for_ops,
1307 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
1308 sh->ops.request = ops_request;
1310 atomic_inc(&sh->count);
1311 async_schedule(async_run_ops, sh);
1314 #define raid_run_ops __raid_run_ops
1317 static int grow_one_stripe(raid5_conf_t *conf)
1319 struct stripe_head *sh;
1320 sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
1324 sh->raid_conf = conf;
1325 spin_lock_init(&sh->lock);
1326 #ifdef CONFIG_MULTICORE_RAID456
1327 init_waitqueue_head(&sh->ops.wait_for_ops);
1330 if (grow_buffers(sh)) {
1332 kmem_cache_free(conf->slab_cache, sh);
1335 /* we just created an active stripe so... */
1336 atomic_set(&sh->count, 1);
1337 atomic_inc(&conf->active_stripes);
1338 INIT_LIST_HEAD(&sh->lru);
1343 static int grow_stripes(raid5_conf_t *conf, int num)
1345 struct kmem_cache *sc;
1346 int devs = max(conf->raid_disks, conf->previous_raid_disks);
1348 if (conf->mddev->gendisk)
1349 sprintf(conf->cache_name[0],
1350 "raid%d-%s", conf->level, mdname(conf->mddev));
1352 sprintf(conf->cache_name[0],
1353 "raid%d-%p", conf->level, conf->mddev);
1354 sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
1356 conf->active_name = 0;
1357 sc = kmem_cache_create(conf->cache_name[conf->active_name],
1358 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
1362 conf->slab_cache = sc;
1363 conf->pool_size = devs;
1365 if (!grow_one_stripe(conf))
1371 * scribble_len - return the required size of the scribble region
1372 * @num - total number of disks in the array
1374 * The size must be enough to contain:
1375 * 1/ a struct page pointer for each device in the array +2
1376 * 2/ room to convert each entry in (1) to its corresponding dma
1377 * (dma_map_page()) or page (page_address()) address.
1379 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1380 * calculate over all devices (not just the data blocks), using zeros in place
1381 * of the P and Q blocks.
1383 static size_t scribble_len(int num)
1387 len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
1392 static int resize_stripes(raid5_conf_t *conf, int newsize)
1394 /* Make all the stripes able to hold 'newsize' devices.
1395 * New slots in each stripe get 'page' set to a new page.
1397 * This happens in stages:
1398 * 1/ create a new kmem_cache and allocate the required number of
1400 * 2/ gather all the old stripe_heads and tranfer the pages across
1401 * to the new stripe_heads. This will have the side effect of
1402 * freezing the array as once all stripe_heads have been collected,
1403 * no IO will be possible. Old stripe heads are freed once their
1404 * pages have been transferred over, and the old kmem_cache is
1405 * freed when all stripes are done.
1406 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1407 * we simple return a failre status - no need to clean anything up.
1408 * 4/ allocate new pages for the new slots in the new stripe_heads.
1409 * If this fails, we don't bother trying the shrink the
1410 * stripe_heads down again, we just leave them as they are.
1411 * As each stripe_head is processed the new one is released into
1414 * Once step2 is started, we cannot afford to wait for a write,
1415 * so we use GFP_NOIO allocations.
1417 struct stripe_head *osh, *nsh;
1418 LIST_HEAD(newstripes);
1419 struct disk_info *ndisks;
1422 struct kmem_cache *sc;
1425 if (newsize <= conf->pool_size)
1426 return 0; /* never bother to shrink */
1428 err = md_allow_write(conf->mddev);
1433 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1434 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
1439 for (i = conf->max_nr_stripes; i; i--) {
1440 nsh = kmem_cache_zalloc(sc, GFP_KERNEL);
1444 nsh->raid_conf = conf;
1445 spin_lock_init(&nsh->lock);
1446 #ifdef CONFIG_MULTICORE_RAID456
1447 init_waitqueue_head(&nsh->ops.wait_for_ops);
1450 list_add(&nsh->lru, &newstripes);
1453 /* didn't get enough, give up */
1454 while (!list_empty(&newstripes)) {
1455 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1456 list_del(&nsh->lru);
1457 kmem_cache_free(sc, nsh);
1459 kmem_cache_destroy(sc);
1462 /* Step 2 - Must use GFP_NOIO now.
1463 * OK, we have enough stripes, start collecting inactive
1464 * stripes and copying them over
1466 list_for_each_entry(nsh, &newstripes, lru) {
1467 spin_lock_irq(&conf->device_lock);
1468 wait_event_lock_irq(conf->wait_for_stripe,
1469 !list_empty(&conf->inactive_list),
1472 osh = get_free_stripe(conf);
1473 spin_unlock_irq(&conf->device_lock);
1474 atomic_set(&nsh->count, 1);
1475 for(i=0; i<conf->pool_size; i++)
1476 nsh->dev[i].page = osh->dev[i].page;
1477 for( ; i<newsize; i++)
1478 nsh->dev[i].page = NULL;
1479 kmem_cache_free(conf->slab_cache, osh);
1481 kmem_cache_destroy(conf->slab_cache);
1484 * At this point, we are holding all the stripes so the array
1485 * is completely stalled, so now is a good time to resize
1486 * conf->disks and the scribble region
1488 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1490 for (i=0; i<conf->raid_disks; i++)
1491 ndisks[i] = conf->disks[i];
1493 conf->disks = ndisks;
1498 conf->scribble_len = scribble_len(newsize);
1499 for_each_present_cpu(cpu) {
1500 struct raid5_percpu *percpu;
1503 percpu = per_cpu_ptr(conf->percpu, cpu);
1504 scribble = kmalloc(conf->scribble_len, GFP_NOIO);
1507 kfree(percpu->scribble);
1508 percpu->scribble = scribble;
1516 /* Step 4, return new stripes to service */
1517 while(!list_empty(&newstripes)) {
1518 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1519 list_del_init(&nsh->lru);
1521 for (i=conf->raid_disks; i < newsize; i++)
1522 if (nsh->dev[i].page == NULL) {
1523 struct page *p = alloc_page(GFP_NOIO);
1524 nsh->dev[i].page = p;
1528 release_stripe(nsh);
1530 /* critical section pass, GFP_NOIO no longer needed */
1532 conf->slab_cache = sc;
1533 conf->active_name = 1-conf->active_name;
1534 conf->pool_size = newsize;
1538 static int drop_one_stripe(raid5_conf_t *conf)
1540 struct stripe_head *sh;
1542 spin_lock_irq(&conf->device_lock);
1543 sh = get_free_stripe(conf);
1544 spin_unlock_irq(&conf->device_lock);
1547 BUG_ON(atomic_read(&sh->count));
1549 kmem_cache_free(conf->slab_cache, sh);
1550 atomic_dec(&conf->active_stripes);
1554 static void shrink_stripes(raid5_conf_t *conf)
1556 while (drop_one_stripe(conf))
1559 if (conf->slab_cache)
1560 kmem_cache_destroy(conf->slab_cache);
1561 conf->slab_cache = NULL;
1564 static void raid5_end_read_request(struct bio * bi, int error)
1566 struct stripe_head *sh = bi->bi_private;
1567 raid5_conf_t *conf = sh->raid_conf;
1568 int disks = sh->disks, i;
1569 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1570 char b[BDEVNAME_SIZE];
1574 for (i=0 ; i<disks; i++)
1575 if (bi == &sh->dev[i].req)
1578 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1579 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1587 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1588 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1589 rdev = conf->disks[i].rdev;
1590 printk_rl(KERN_INFO "md/raid:%s: read error corrected"
1591 " (%lu sectors at %llu on %s)\n",
1592 mdname(conf->mddev), STRIPE_SECTORS,
1593 (unsigned long long)(sh->sector
1594 + rdev->data_offset),
1595 bdevname(rdev->bdev, b));
1596 clear_bit(R5_ReadError, &sh->dev[i].flags);
1597 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1599 if (atomic_read(&conf->disks[i].rdev->read_errors))
1600 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1602 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
1604 rdev = conf->disks[i].rdev;
1606 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1607 atomic_inc(&rdev->read_errors);
1608 if (conf->mddev->degraded >= conf->max_degraded)
1609 printk_rl(KERN_WARNING
1610 "md/raid:%s: read error not correctable "
1611 "(sector %llu on %s).\n",
1612 mdname(conf->mddev),
1613 (unsigned long long)(sh->sector
1614 + rdev->data_offset),
1616 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
1618 printk_rl(KERN_WARNING
1619 "md/raid:%s: read error NOT corrected!! "
1620 "(sector %llu on %s).\n",
1621 mdname(conf->mddev),
1622 (unsigned long long)(sh->sector
1623 + rdev->data_offset),
1625 else if (atomic_read(&rdev->read_errors)
1626 > conf->max_nr_stripes)
1628 "md/raid:%s: Too many read errors, failing device %s.\n",
1629 mdname(conf->mddev), bdn);
1633 set_bit(R5_ReadError, &sh->dev[i].flags);
1635 clear_bit(R5_ReadError, &sh->dev[i].flags);
1636 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1637 md_error(conf->mddev, rdev);
1640 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1641 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1642 set_bit(STRIPE_HANDLE, &sh->state);
1646 static void raid5_end_write_request(struct bio *bi, int error)
1648 struct stripe_head *sh = bi->bi_private;
1649 raid5_conf_t *conf = sh->raid_conf;
1650 int disks = sh->disks, i;
1651 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1653 for (i=0 ; i<disks; i++)
1654 if (bi == &sh->dev[i].req)
1657 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1658 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1666 md_error(conf->mddev, conf->disks[i].rdev);
1668 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1670 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1671 set_bit(STRIPE_HANDLE, &sh->state);
1676 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1678 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1680 struct r5dev *dev = &sh->dev[i];
1682 bio_init(&dev->req);
1683 dev->req.bi_io_vec = &dev->vec;
1685 dev->req.bi_max_vecs++;
1686 dev->vec.bv_page = dev->page;
1687 dev->vec.bv_len = STRIPE_SIZE;
1688 dev->vec.bv_offset = 0;
1690 dev->req.bi_sector = sh->sector;
1691 dev->req.bi_private = sh;
1694 dev->sector = compute_blocknr(sh, i, previous);
1697 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1699 char b[BDEVNAME_SIZE];
1700 raid5_conf_t *conf = mddev->private;
1701 pr_debug("raid456: error called\n");
1703 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1704 unsigned long flags;
1705 spin_lock_irqsave(&conf->device_lock, flags);
1707 spin_unlock_irqrestore(&conf->device_lock, flags);
1709 * if recovery was running, make sure it aborts.
1711 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1713 set_bit(Faulty, &rdev->flags);
1714 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1716 "md/raid:%s: Disk failure on %s, disabling device.\n"
1717 "md/raid:%s: Operation continuing on %d devices.\n",
1719 bdevname(rdev->bdev, b),
1721 conf->raid_disks - mddev->degraded);
1725 * Input: a 'big' sector number,
1726 * Output: index of the data and parity disk, and the sector # in them.
1728 static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
1729 int previous, int *dd_idx,
1730 struct stripe_head *sh)
1732 sector_t stripe, stripe2;
1733 sector_t chunk_number;
1734 unsigned int chunk_offset;
1737 sector_t new_sector;
1738 int algorithm = previous ? conf->prev_algo
1740 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1741 : conf->chunk_sectors;
1742 int raid_disks = previous ? conf->previous_raid_disks
1744 int data_disks = raid_disks - conf->max_degraded;
1746 /* First compute the information on this sector */
1749 * Compute the chunk number and the sector offset inside the chunk
1751 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1752 chunk_number = r_sector;
1755 * Compute the stripe number
1757 stripe = chunk_number;
1758 *dd_idx = sector_div(stripe, data_disks);
1761 * Select the parity disk based on the user selected algorithm.
1763 pd_idx = qd_idx = ~0;
1764 switch(conf->level) {
1766 pd_idx = data_disks;
1769 switch (algorithm) {
1770 case ALGORITHM_LEFT_ASYMMETRIC:
1771 pd_idx = data_disks - sector_div(stripe2, raid_disks);
1772 if (*dd_idx >= pd_idx)
1775 case ALGORITHM_RIGHT_ASYMMETRIC:
1776 pd_idx = sector_div(stripe2, raid_disks);
1777 if (*dd_idx >= pd_idx)
1780 case ALGORITHM_LEFT_SYMMETRIC:
1781 pd_idx = data_disks - sector_div(stripe2, raid_disks);
1782 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1784 case ALGORITHM_RIGHT_SYMMETRIC:
1785 pd_idx = sector_div(stripe2, raid_disks);
1786 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1788 case ALGORITHM_PARITY_0:
1792 case ALGORITHM_PARITY_N:
1793 pd_idx = data_disks;
1801 switch (algorithm) {
1802 case ALGORITHM_LEFT_ASYMMETRIC:
1803 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1804 qd_idx = pd_idx + 1;
1805 if (pd_idx == raid_disks-1) {
1806 (*dd_idx)++; /* Q D D D P */
1808 } else if (*dd_idx >= pd_idx)
1809 (*dd_idx) += 2; /* D D P Q D */
1811 case ALGORITHM_RIGHT_ASYMMETRIC:
1812 pd_idx = sector_div(stripe2, raid_disks);
1813 qd_idx = pd_idx + 1;
1814 if (pd_idx == raid_disks-1) {
1815 (*dd_idx)++; /* Q D D D P */
1817 } else if (*dd_idx >= pd_idx)
1818 (*dd_idx) += 2; /* D D P Q D */
1820 case ALGORITHM_LEFT_SYMMETRIC:
1821 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1822 qd_idx = (pd_idx + 1) % raid_disks;
1823 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1825 case ALGORITHM_RIGHT_SYMMETRIC:
1826 pd_idx = sector_div(stripe2, raid_disks);
1827 qd_idx = (pd_idx + 1) % raid_disks;
1828 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1831 case ALGORITHM_PARITY_0:
1836 case ALGORITHM_PARITY_N:
1837 pd_idx = data_disks;
1838 qd_idx = data_disks + 1;
1841 case ALGORITHM_ROTATING_ZERO_RESTART:
1842 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1843 * of blocks for computing Q is different.
1845 pd_idx = sector_div(stripe2, raid_disks);
1846 qd_idx = pd_idx + 1;
1847 if (pd_idx == raid_disks-1) {
1848 (*dd_idx)++; /* Q D D D P */
1850 } else if (*dd_idx >= pd_idx)
1851 (*dd_idx) += 2; /* D D P Q D */
1855 case ALGORITHM_ROTATING_N_RESTART:
1856 /* Same a left_asymmetric, by first stripe is
1857 * D D D P Q rather than
1861 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1862 qd_idx = pd_idx + 1;
1863 if (pd_idx == raid_disks-1) {
1864 (*dd_idx)++; /* Q D D D P */
1866 } else if (*dd_idx >= pd_idx)
1867 (*dd_idx) += 2; /* D D P Q D */
1871 case ALGORITHM_ROTATING_N_CONTINUE:
1872 /* Same as left_symmetric but Q is before P */
1873 pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
1874 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1875 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1879 case ALGORITHM_LEFT_ASYMMETRIC_6:
1880 /* RAID5 left_asymmetric, with Q on last device */
1881 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
1882 if (*dd_idx >= pd_idx)
1884 qd_idx = raid_disks - 1;
1887 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1888 pd_idx = sector_div(stripe2, raid_disks-1);
1889 if (*dd_idx >= pd_idx)
1891 qd_idx = raid_disks - 1;
1894 case ALGORITHM_LEFT_SYMMETRIC_6:
1895 pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
1896 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1897 qd_idx = raid_disks - 1;
1900 case ALGORITHM_RIGHT_SYMMETRIC_6:
1901 pd_idx = sector_div(stripe2, raid_disks-1);
1902 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1903 qd_idx = raid_disks - 1;
1906 case ALGORITHM_PARITY_0_6:
1909 qd_idx = raid_disks - 1;
1919 sh->pd_idx = pd_idx;
1920 sh->qd_idx = qd_idx;
1921 sh->ddf_layout = ddf_layout;
1924 * Finally, compute the new sector number
1926 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1931 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
1933 raid5_conf_t *conf = sh->raid_conf;
1934 int raid_disks = sh->disks;
1935 int data_disks = raid_disks - conf->max_degraded;
1936 sector_t new_sector = sh->sector, check;
1937 int sectors_per_chunk = previous ? conf->prev_chunk_sectors
1938 : conf->chunk_sectors;
1939 int algorithm = previous ? conf->prev_algo
1943 sector_t chunk_number;
1944 int dummy1, dd_idx = i;
1946 struct stripe_head sh2;
1949 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1950 stripe = new_sector;
1952 if (i == sh->pd_idx)
1954 switch(conf->level) {
1957 switch (algorithm) {
1958 case ALGORITHM_LEFT_ASYMMETRIC:
1959 case ALGORITHM_RIGHT_ASYMMETRIC:
1963 case ALGORITHM_LEFT_SYMMETRIC:
1964 case ALGORITHM_RIGHT_SYMMETRIC:
1967 i -= (sh->pd_idx + 1);
1969 case ALGORITHM_PARITY_0:
1972 case ALGORITHM_PARITY_N:
1979 if (i == sh->qd_idx)
1980 return 0; /* It is the Q disk */
1981 switch (algorithm) {
1982 case ALGORITHM_LEFT_ASYMMETRIC:
1983 case ALGORITHM_RIGHT_ASYMMETRIC:
1984 case ALGORITHM_ROTATING_ZERO_RESTART:
1985 case ALGORITHM_ROTATING_N_RESTART:
1986 if (sh->pd_idx == raid_disks-1)
1987 i--; /* Q D D D P */
1988 else if (i > sh->pd_idx)
1989 i -= 2; /* D D P Q D */
1991 case ALGORITHM_LEFT_SYMMETRIC:
1992 case ALGORITHM_RIGHT_SYMMETRIC:
1993 if (sh->pd_idx == raid_disks-1)
1994 i--; /* Q D D D P */
1999 i -= (sh->pd_idx + 2);
2002 case ALGORITHM_PARITY_0:
2005 case ALGORITHM_PARITY_N:
2007 case ALGORITHM_ROTATING_N_CONTINUE:
2008 /* Like left_symmetric, but P is before Q */
2009 if (sh->pd_idx == 0)
2010 i--; /* P D D D Q */
2015 i -= (sh->pd_idx + 1);
2018 case ALGORITHM_LEFT_ASYMMETRIC_6:
2019 case ALGORITHM_RIGHT_ASYMMETRIC_6:
2023 case ALGORITHM_LEFT_SYMMETRIC_6:
2024 case ALGORITHM_RIGHT_SYMMETRIC_6:
2026 i += data_disks + 1;
2027 i -= (sh->pd_idx + 1);
2029 case ALGORITHM_PARITY_0_6:
2038 chunk_number = stripe * data_disks + i;
2039 r_sector = chunk_number * sectors_per_chunk + chunk_offset;
2041 check = raid5_compute_sector(conf, r_sector,
2042 previous, &dummy1, &sh2);
2043 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
2044 || sh2.qd_idx != sh->qd_idx) {
2045 printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
2046 mdname(conf->mddev));
2054 schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
2055 int rcw, int expand)
2057 int i, pd_idx = sh->pd_idx, disks = sh->disks;
2058 raid5_conf_t *conf = sh->raid_conf;
2059 int level = conf->level;
2062 /* if we are not expanding this is a proper write request, and
2063 * there will be bios with new data to be drained into the
2067 sh->reconstruct_state = reconstruct_state_drain_run;
2068 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2070 sh->reconstruct_state = reconstruct_state_run;
2072 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2074 for (i = disks; i--; ) {
2075 struct r5dev *dev = &sh->dev[i];
2078 set_bit(R5_LOCKED, &dev->flags);
2079 set_bit(R5_Wantdrain, &dev->flags);
2081 clear_bit(R5_UPTODATE, &dev->flags);
2085 if (s->locked + conf->max_degraded == disks)
2086 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2087 atomic_inc(&conf->pending_full_writes);
2090 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
2091 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
2093 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
2094 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
2095 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
2096 set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
2098 for (i = disks; i--; ) {
2099 struct r5dev *dev = &sh->dev[i];
2104 (test_bit(R5_UPTODATE, &dev->flags) ||
2105 test_bit(R5_Wantcompute, &dev->flags))) {
2106 set_bit(R5_Wantdrain, &dev->flags);
2107 set_bit(R5_LOCKED, &dev->flags);
2108 clear_bit(R5_UPTODATE, &dev->flags);
2114 /* keep the parity disk(s) locked while asynchronous operations
2117 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
2118 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2122 int qd_idx = sh->qd_idx;
2123 struct r5dev *dev = &sh->dev[qd_idx];
2125 set_bit(R5_LOCKED, &dev->flags);
2126 clear_bit(R5_UPTODATE, &dev->flags);
2130 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2131 __func__, (unsigned long long)sh->sector,
2132 s->locked, s->ops_request);
2136 * Each stripe/dev can have one or more bion attached.
2137 * toread/towrite point to the first in a chain.
2138 * The bi_next chain must be in order.
2140 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
2143 raid5_conf_t *conf = sh->raid_conf;
2146 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2147 (unsigned long long)bi->bi_sector,
2148 (unsigned long long)sh->sector);
2151 spin_lock(&sh->lock);
2152 spin_lock_irq(&conf->device_lock);
2154 bip = &sh->dev[dd_idx].towrite;
2155 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
2158 bip = &sh->dev[dd_idx].toread;
2159 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
2160 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
2162 bip = & (*bip)->bi_next;
2164 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
2167 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
2171 bi->bi_phys_segments++;
2174 /* check if page is covered */
2175 sector_t sector = sh->dev[dd_idx].sector;
2176 for (bi=sh->dev[dd_idx].towrite;
2177 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
2178 bi && bi->bi_sector <= sector;
2179 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
2180 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
2181 sector = bi->bi_sector + (bi->bi_size>>9);
2183 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
2184 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
2186 spin_unlock_irq(&conf->device_lock);
2187 spin_unlock(&sh->lock);
2189 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2190 (unsigned long long)(*bip)->bi_sector,
2191 (unsigned long long)sh->sector, dd_idx);
2193 if (conf->mddev->bitmap && firstwrite) {
2194 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
2196 sh->bm_seq = conf->seq_flush+1;
2197 set_bit(STRIPE_BIT_DELAY, &sh->state);
2202 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
2203 spin_unlock_irq(&conf->device_lock);
2204 spin_unlock(&sh->lock);
2208 static void end_reshape(raid5_conf_t *conf);
2210 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
2211 struct stripe_head *sh)
2213 int sectors_per_chunk =
2214 previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
2216 int chunk_offset = sector_div(stripe, sectors_per_chunk);
2217 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2219 raid5_compute_sector(conf,
2220 stripe * (disks - conf->max_degraded)
2221 *sectors_per_chunk + chunk_offset,
2227 handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
2228 struct stripe_head_state *s, int disks,
2229 struct bio **return_bi)
2232 for (i = disks; i--; ) {
2236 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2239 rdev = rcu_dereference(conf->disks[i].rdev);
2240 if (rdev && test_bit(In_sync, &rdev->flags))
2241 /* multiple read failures in one stripe */
2242 md_error(conf->mddev, rdev);
2245 spin_lock_irq(&conf->device_lock);
2246 /* fail all writes first */
2247 bi = sh->dev[i].towrite;
2248 sh->dev[i].towrite = NULL;
2254 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2255 wake_up(&conf->wait_for_overlap);
2257 while (bi && bi->bi_sector <
2258 sh->dev[i].sector + STRIPE_SECTORS) {
2259 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2260 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2261 if (!raid5_dec_bi_phys_segments(bi)) {
2262 md_write_end(conf->mddev);
2263 bi->bi_next = *return_bi;
2268 /* and fail all 'written' */
2269 bi = sh->dev[i].written;
2270 sh->dev[i].written = NULL;
2271 if (bi) bitmap_end = 1;
2272 while (bi && bi->bi_sector <
2273 sh->dev[i].sector + STRIPE_SECTORS) {
2274 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2275 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2276 if (!raid5_dec_bi_phys_segments(bi)) {
2277 md_write_end(conf->mddev);
2278 bi->bi_next = *return_bi;
2284 /* fail any reads if this device is non-operational and
2285 * the data has not reached the cache yet.
2287 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2288 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2289 test_bit(R5_ReadError, &sh->dev[i].flags))) {
2290 bi = sh->dev[i].toread;
2291 sh->dev[i].toread = NULL;
2292 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2293 wake_up(&conf->wait_for_overlap);
2294 if (bi) s->to_read--;
2295 while (bi && bi->bi_sector <
2296 sh->dev[i].sector + STRIPE_SECTORS) {
2297 struct bio *nextbi =
2298 r5_next_bio(bi, sh->dev[i].sector);
2299 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2300 if (!raid5_dec_bi_phys_segments(bi)) {
2301 bi->bi_next = *return_bi;
2307 spin_unlock_irq(&conf->device_lock);
2309 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2310 STRIPE_SECTORS, 0, 0);
2313 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2314 if (atomic_dec_and_test(&conf->pending_full_writes))
2315 md_wakeup_thread(conf->mddev->thread);
2318 /* fetch_block5 - checks the given member device to see if its data needs
2319 * to be read or computed to satisfy a request.
2321 * Returns 1 when no more member devices need to be checked, otherwise returns
2322 * 0 to tell the loop in handle_stripe_fill5 to continue
2324 static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2325 int disk_idx, int disks)
2327 struct r5dev *dev = &sh->dev[disk_idx];
2328 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2330 /* is the data in this block needed, and can we get it? */
2331 if (!test_bit(R5_LOCKED, &dev->flags) &&
2332 !test_bit(R5_UPTODATE, &dev->flags) &&
2334 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2335 s->syncing || s->expanding ||
2337 (failed_dev->toread ||
2338 (failed_dev->towrite &&
2339 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
2340 /* We would like to get this block, possibly by computing it,
2341 * otherwise read it if the backing disk is insync
2343 if ((s->uptodate == disks - 1) &&
2344 (s->failed && disk_idx == s->failed_num)) {
2345 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2346 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2347 set_bit(R5_Wantcompute, &dev->flags);
2348 sh->ops.target = disk_idx;
2349 sh->ops.target2 = -1;
2351 /* Careful: from this point on 'uptodate' is in the eye
2352 * of raid_run_ops which services 'compute' operations
2353 * before writes. R5_Wantcompute flags a block that will
2354 * be R5_UPTODATE by the time it is needed for a
2355 * subsequent operation.
2358 return 1; /* uptodate + compute == disks */
2359 } else if (test_bit(R5_Insync, &dev->flags)) {
2360 set_bit(R5_LOCKED, &dev->flags);
2361 set_bit(R5_Wantread, &dev->flags);
2363 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2372 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2374 static void handle_stripe_fill5(struct stripe_head *sh,
2375 struct stripe_head_state *s, int disks)
2379 /* look for blocks to read/compute, skip this if a compute
2380 * is already in flight, or if the stripe contents are in the
2381 * midst of changing due to a write
2383 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2384 !sh->reconstruct_state)
2385 for (i = disks; i--; )
2386 if (fetch_block5(sh, s, i, disks))
2388 set_bit(STRIPE_HANDLE, &sh->state);
2391 /* fetch_block6 - checks the given member device to see if its data needs
2392 * to be read or computed to satisfy a request.
2394 * Returns 1 when no more member devices need to be checked, otherwise returns
2395 * 0 to tell the loop in handle_stripe_fill6 to continue
2397 static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
2398 struct r6_state *r6s, int disk_idx, int disks)
2400 struct r5dev *dev = &sh->dev[disk_idx];
2401 struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]],
2402 &sh->dev[r6s->failed_num[1]] };
2404 if (!test_bit(R5_LOCKED, &dev->flags) &&
2405 !test_bit(R5_UPTODATE, &dev->flags) &&
2407 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2408 s->syncing || s->expanding ||
2410 (fdev[0]->toread || s->to_write)) ||
2412 (fdev[1]->toread || s->to_write)))) {
2413 /* we would like to get this block, possibly by computing it,
2414 * otherwise read it if the backing disk is insync
2416 BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
2417 BUG_ON(test_bit(R5_Wantread, &dev->flags));
2418 if ((s->uptodate == disks - 1) &&
2419 (s->failed && (disk_idx == r6s->failed_num[0] ||
2420 disk_idx == r6s->failed_num[1]))) {
2421 /* have disk failed, and we're requested to fetch it;
2424 pr_debug("Computing stripe %llu block %d\n",
2425 (unsigned long long)sh->sector, disk_idx);
2426 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2427 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2428 set_bit(R5_Wantcompute, &dev->flags);
2429 sh->ops.target = disk_idx;
2430 sh->ops.target2 = -1; /* no 2nd target */
2434 } else if (s->uptodate == disks-2 && s->failed >= 2) {
2435 /* Computing 2-failure is *very* expensive; only
2436 * do it if failed >= 2
2439 for (other = disks; other--; ) {
2440 if (other == disk_idx)
2442 if (!test_bit(R5_UPTODATE,
2443 &sh->dev[other].flags))
2447 pr_debug("Computing stripe %llu blocks %d,%d\n",
2448 (unsigned long long)sh->sector,
2450 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2451 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2452 set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
2453 set_bit(R5_Wantcompute, &sh->dev[other].flags);
2454 sh->ops.target = disk_idx;
2455 sh->ops.target2 = other;
2459 } else if (test_bit(R5_Insync, &dev->flags)) {
2460 set_bit(R5_LOCKED, &dev->flags);
2461 set_bit(R5_Wantread, &dev->flags);
2463 pr_debug("Reading block %d (sync=%d)\n",
2464 disk_idx, s->syncing);
2472 * handle_stripe_fill6 - read or compute data to satisfy pending requests.
2474 static void handle_stripe_fill6(struct stripe_head *sh,
2475 struct stripe_head_state *s, struct r6_state *r6s,
2480 /* look for blocks to read/compute, skip this if a compute
2481 * is already in flight, or if the stripe contents are in the
2482 * midst of changing due to a write
2484 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2485 !sh->reconstruct_state)
2486 for (i = disks; i--; )
2487 if (fetch_block6(sh, s, r6s, i, disks))
2489 set_bit(STRIPE_HANDLE, &sh->state);
2493 /* handle_stripe_clean_event
2494 * any written block on an uptodate or failed drive can be returned.
2495 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2496 * never LOCKED, so we don't need to test 'failed' directly.
2498 static void handle_stripe_clean_event(raid5_conf_t *conf,
2499 struct stripe_head *sh, int disks, struct bio **return_bi)
2504 for (i = disks; i--; )
2505 if (sh->dev[i].written) {
2507 if (!test_bit(R5_LOCKED, &dev->flags) &&
2508 test_bit(R5_UPTODATE, &dev->flags)) {
2509 /* We can return any write requests */
2510 struct bio *wbi, *wbi2;
2512 pr_debug("Return write for disc %d\n", i);
2513 spin_lock_irq(&conf->device_lock);
2515 dev->written = NULL;
2516 while (wbi && wbi->bi_sector <
2517 dev->sector + STRIPE_SECTORS) {
2518 wbi2 = r5_next_bio(wbi, dev->sector);
2519 if (!raid5_dec_bi_phys_segments(wbi)) {
2520 md_write_end(conf->mddev);
2521 wbi->bi_next = *return_bi;
2526 if (dev->towrite == NULL)
2528 spin_unlock_irq(&conf->device_lock);
2530 bitmap_endwrite(conf->mddev->bitmap,
2533 !test_bit(STRIPE_DEGRADED, &sh->state),
2538 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2539 if (atomic_dec_and_test(&conf->pending_full_writes))
2540 md_wakeup_thread(conf->mddev->thread);
2543 static void handle_stripe_dirtying5(raid5_conf_t *conf,
2544 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2546 int rmw = 0, rcw = 0, i;
2547 for (i = disks; i--; ) {
2548 /* would I have to read this buffer for read_modify_write */
2549 struct r5dev *dev = &sh->dev[i];
2550 if ((dev->towrite || i == sh->pd_idx) &&
2551 !test_bit(R5_LOCKED, &dev->flags) &&
2552 !(test_bit(R5_UPTODATE, &dev->flags) ||
2553 test_bit(R5_Wantcompute, &dev->flags))) {
2554 if (test_bit(R5_Insync, &dev->flags))
2557 rmw += 2*disks; /* cannot read it */
2559 /* Would I have to read this buffer for reconstruct_write */
2560 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2561 !test_bit(R5_LOCKED, &dev->flags) &&
2562 !(test_bit(R5_UPTODATE, &dev->flags) ||
2563 test_bit(R5_Wantcompute, &dev->flags))) {
2564 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2569 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2570 (unsigned long long)sh->sector, rmw, rcw);
2571 set_bit(STRIPE_HANDLE, &sh->state);
2572 if (rmw < rcw && rmw > 0)
2573 /* prefer read-modify-write, but need to get some data */
2574 for (i = disks; i--; ) {
2575 struct r5dev *dev = &sh->dev[i];
2576 if ((dev->towrite || i == sh->pd_idx) &&
2577 !test_bit(R5_LOCKED, &dev->flags) &&
2578 !(test_bit(R5_UPTODATE, &dev->flags) ||
2579 test_bit(R5_Wantcompute, &dev->flags)) &&
2580 test_bit(R5_Insync, &dev->flags)) {
2582 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2583 pr_debug("Read_old block "
2584 "%d for r-m-w\n", i);
2585 set_bit(R5_LOCKED, &dev->flags);
2586 set_bit(R5_Wantread, &dev->flags);
2589 set_bit(STRIPE_DELAYED, &sh->state);
2590 set_bit(STRIPE_HANDLE, &sh->state);
2594 if (rcw <= rmw && rcw > 0)
2595 /* want reconstruct write, but need to get some data */
2596 for (i = disks; i--; ) {
2597 struct r5dev *dev = &sh->dev[i];
2598 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2600 !test_bit(R5_LOCKED, &dev->flags) &&
2601 !(test_bit(R5_UPTODATE, &dev->flags) ||
2602 test_bit(R5_Wantcompute, &dev->flags)) &&
2603 test_bit(R5_Insync, &dev->flags)) {
2605 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2606 pr_debug("Read_old block "
2607 "%d for Reconstruct\n", i);
2608 set_bit(R5_LOCKED, &dev->flags);
2609 set_bit(R5_Wantread, &dev->flags);
2612 set_bit(STRIPE_DELAYED, &sh->state);
2613 set_bit(STRIPE_HANDLE, &sh->state);
2617 /* now if nothing is locked, and if we have enough data,
2618 * we can start a write request
2620 /* since handle_stripe can be called at any time we need to handle the
2621 * case where a compute block operation has been submitted and then a
2622 * subsequent call wants to start a write request. raid_run_ops only
2623 * handles the case where compute block and reconstruct are requested
2624 * simultaneously. If this is not the case then new writes need to be
2625 * held off until the compute completes.
2627 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2628 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2629 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
2630 schedule_reconstruction(sh, s, rcw == 0, 0);
2633 static void handle_stripe_dirtying6(raid5_conf_t *conf,
2634 struct stripe_head *sh, struct stripe_head_state *s,
2635 struct r6_state *r6s, int disks)
2637 int rcw = 0, pd_idx = sh->pd_idx, i;
2638 int qd_idx = sh->qd_idx;
2640 set_bit(STRIPE_HANDLE, &sh->state);
2641 for (i = disks; i--; ) {
2642 struct r5dev *dev = &sh->dev[i];
2643 /* check if we haven't enough data */
2644 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2645 i != pd_idx && i != qd_idx &&
2646 !test_bit(R5_LOCKED, &dev->flags) &&
2647 !(test_bit(R5_UPTODATE, &dev->flags) ||
2648 test_bit(R5_Wantcompute, &dev->flags))) {
2650 if (!test_bit(R5_Insync, &dev->flags))
2651 continue; /* it's a failed drive */
2654 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2655 pr_debug("Read_old stripe %llu "
2656 "block %d for Reconstruct\n",
2657 (unsigned long long)sh->sector, i);
2658 set_bit(R5_LOCKED, &dev->flags);
2659 set_bit(R5_Wantread, &dev->flags);
2662 pr_debug("Request delayed stripe %llu "
2663 "block %d for Reconstruct\n",
2664 (unsigned long long)sh->sector, i);
2665 set_bit(STRIPE_DELAYED, &sh->state);
2666 set_bit(STRIPE_HANDLE, &sh->state);
2670 /* now if nothing is locked, and if we have enough data, we can start a
2673 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2674 s->locked == 0 && rcw == 0 &&
2675 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2676 schedule_reconstruction(sh, s, 1, 0);
2680 static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2681 struct stripe_head_state *s, int disks)
2683 struct r5dev *dev = NULL;
2685 set_bit(STRIPE_HANDLE, &sh->state);
2687 switch (sh->check_state) {
2688 case check_state_idle:
2689 /* start a new check operation if there are no failures */
2690 if (s->failed == 0) {
2691 BUG_ON(s->uptodate != disks);
2692 sh->check_state = check_state_run;
2693 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2694 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2698 dev = &sh->dev[s->failed_num];
2700 case check_state_compute_result:
2701 sh->check_state = check_state_idle;
2703 dev = &sh->dev[sh->pd_idx];
2705 /* check that a write has not made the stripe insync */
2706 if (test_bit(STRIPE_INSYNC, &sh->state))
2709 /* either failed parity check, or recovery is happening */
2710 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2711 BUG_ON(s->uptodate != disks);
2713 set_bit(R5_LOCKED, &dev->flags);
2715 set_bit(R5_Wantwrite, &dev->flags);
2717 clear_bit(STRIPE_DEGRADED, &sh->state);
2718 set_bit(STRIPE_INSYNC, &sh->state);
2720 case check_state_run:
2721 break; /* we will be called again upon completion */
2722 case check_state_check_result:
2723 sh->check_state = check_state_idle;
2725 /* if a failure occurred during the check operation, leave
2726 * STRIPE_INSYNC not set and let the stripe be handled again
2731 /* handle a successful check operation, if parity is correct
2732 * we are done. Otherwise update the mismatch count and repair
2733 * parity if !MD_RECOVERY_CHECK
2735 if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
2736 /* parity is correct (on disc,
2737 * not in buffer any more)
2739 set_bit(STRIPE_INSYNC, &sh->state);
2741 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2742 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2743 /* don't try to repair!! */
2744 set_bit(STRIPE_INSYNC, &sh->state);
2746 sh->check_state = check_state_compute_run;
2747 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2748 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2749 set_bit(R5_Wantcompute,
2750 &sh->dev[sh->pd_idx].flags);
2751 sh->ops.target = sh->pd_idx;
2752 sh->ops.target2 = -1;
2757 case check_state_compute_run:
2760 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2761 __func__, sh->check_state,
2762 (unsigned long long) sh->sector);
2768 static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2769 struct stripe_head_state *s,
2770 struct r6_state *r6s, int disks)
2772 int pd_idx = sh->pd_idx;
2773 int qd_idx = sh->qd_idx;
2776 set_bit(STRIPE_HANDLE, &sh->state);
2778 BUG_ON(s->failed > 2);
2780 /* Want to check and possibly repair P and Q.
2781 * However there could be one 'failed' device, in which
2782 * case we can only check one of them, possibly using the
2783 * other to generate missing data
2786 switch (sh->check_state) {
2787 case check_state_idle:
2788 /* start a new check operation if there are < 2 failures */
2789 if (s->failed == r6s->q_failed) {
2790 /* The only possible failed device holds Q, so it
2791 * makes sense to check P (If anything else were failed,
2792 * we would have used P to recreate it).
2794 sh->check_state = check_state_run;
2796 if (!r6s->q_failed && s->failed < 2) {
2797 /* Q is not failed, and we didn't use it to generate
2798 * anything, so it makes sense to check it
2800 if (sh->check_state == check_state_run)
2801 sh->check_state = check_state_run_pq;
2803 sh->check_state = check_state_run_q;
2806 /* discard potentially stale zero_sum_result */
2807 sh->ops.zero_sum_result = 0;
2809 if (sh->check_state == check_state_run) {
2810 /* async_xor_zero_sum destroys the contents of P */
2811 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
2814 if (sh->check_state >= check_state_run &&
2815 sh->check_state <= check_state_run_pq) {
2816 /* async_syndrome_zero_sum preserves P and Q, so
2817 * no need to mark them !uptodate here
2819 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2823 /* we have 2-disk failure */
2824 BUG_ON(s->failed != 2);
2826 case check_state_compute_result:
2827 sh->check_state = check_state_idle;
2829 /* check that a write has not made the stripe insync */
2830 if (test_bit(STRIPE_INSYNC, &sh->state))
2833 /* now write out any block on a failed drive,
2834 * or P or Q if they were recomputed
2836 BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
2837 if (s->failed == 2) {
2838 dev = &sh->dev[r6s->failed_num[1]];
2840 set_bit(R5_LOCKED, &dev->flags);
2841 set_bit(R5_Wantwrite, &dev->flags);
2843 if (s->failed >= 1) {
2844 dev = &sh->dev[r6s->failed_num[0]];
2846 set_bit(R5_LOCKED, &dev->flags);
2847 set_bit(R5_Wantwrite, &dev->flags);
2849 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2850 dev = &sh->dev[pd_idx];
2852 set_bit(R5_LOCKED, &dev->flags);
2853 set_bit(R5_Wantwrite, &dev->flags);
2855 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2856 dev = &sh->dev[qd_idx];
2858 set_bit(R5_LOCKED, &dev->flags);
2859 set_bit(R5_Wantwrite, &dev->flags);
2861 clear_bit(STRIPE_DEGRADED, &sh->state);
2863 set_bit(STRIPE_INSYNC, &sh->state);
2865 case check_state_run:
2866 case check_state_run_q:
2867 case check_state_run_pq:
2868 break; /* we will be called again upon completion */
2869 case check_state_check_result:
2870 sh->check_state = check_state_idle;
2872 /* handle a successful check operation, if parity is correct
2873 * we are done. Otherwise update the mismatch count and repair
2874 * parity if !MD_RECOVERY_CHECK
2876 if (sh->ops.zero_sum_result == 0) {
2877 /* both parities are correct */
2879 set_bit(STRIPE_INSYNC, &sh->state);
2881 /* in contrast to the raid5 case we can validate
2882 * parity, but still have a failure to write
2885 sh->check_state = check_state_compute_result;
2886 /* Returning at this point means that we may go
2887 * off and bring p and/or q uptodate again so
2888 * we make sure to check zero_sum_result again
2889 * to verify if p or q need writeback
2893 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2894 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2895 /* don't try to repair!! */
2896 set_bit(STRIPE_INSYNC, &sh->state);
2898 int *target = &sh->ops.target;
2900 sh->ops.target = -1;
2901 sh->ops.target2 = -1;
2902 sh->check_state = check_state_compute_run;
2903 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2904 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2905 if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
2906 set_bit(R5_Wantcompute,
2907 &sh->dev[pd_idx].flags);
2909 target = &sh->ops.target2;
2912 if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
2913 set_bit(R5_Wantcompute,
2914 &sh->dev[qd_idx].flags);
2921 case check_state_compute_run:
2924 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2925 __func__, sh->check_state,
2926 (unsigned long long) sh->sector);
2931 static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2932 struct r6_state *r6s)
2936 /* We have read all the blocks in this stripe and now we need to
2937 * copy some of them into a target stripe for expand.
2939 struct dma_async_tx_descriptor *tx = NULL;
2940 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2941 for (i = 0; i < sh->disks; i++)
2942 if (i != sh->pd_idx && i != sh->qd_idx) {
2944 struct stripe_head *sh2;
2945 struct async_submit_ctl submit;
2947 sector_t bn = compute_blocknr(sh, i, 1);
2948 sector_t s = raid5_compute_sector(conf, bn, 0,
2950 sh2 = get_active_stripe(conf, s, 0, 1, 1);
2952 /* so far only the early blocks of this stripe
2953 * have been requested. When later blocks
2954 * get requested, we will try again
2957 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2958 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2959 /* must have already done this block */
2960 release_stripe(sh2);
2964 /* place all the copies on one channel */
2965 init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
2966 tx = async_memcpy(sh2->dev[dd_idx].page,
2967 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2970 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2971 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2972 for (j = 0; j < conf->raid_disks; j++)
2973 if (j != sh2->pd_idx &&
2974 (!r6s || j != sh2->qd_idx) &&
2975 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2977 if (j == conf->raid_disks) {
2978 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2979 set_bit(STRIPE_HANDLE, &sh2->state);
2981 release_stripe(sh2);
2984 /* done submitting copies, wait for them to complete */
2987 dma_wait_for_async_tx(tx);
2993 * handle_stripe - do things to a stripe.
2995 * We lock the stripe and then examine the state of various bits
2996 * to see what needs to be done.
2998 * return some read request which now have data
2999 * return some write requests which are safely on disc
3000 * schedule a read on some buffers
3001 * schedule a write of some buffers
3002 * return confirmation of parity correctness
3004 * buffers are taken off read_list or write_list, and bh_cache buffers
3005 * get BH_Lock set before the stripe lock is released.
3009 static void handle_stripe5(struct stripe_head *sh)
3011 raid5_conf_t *conf = sh->raid_conf;
3012 int disks = sh->disks, i;
3013 struct bio *return_bi = NULL;
3014 struct stripe_head_state s;
3016 mdk_rdev_t *blocked_rdev = NULL;
3018 int dec_preread_active = 0;
3020 memset(&s, 0, sizeof(s));
3021 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
3022 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
3023 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
3024 sh->reconstruct_state);
3026 spin_lock(&sh->lock);
3027 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3028 set_bit(STRIPE_SYNCING, &sh->state);
3029 clear_bit(STRIPE_INSYNC, &sh->state);
3031 clear_bit(STRIPE_HANDLE, &sh->state);
3032 clear_bit(STRIPE_DELAYED, &sh->state);
3034 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3035 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3036 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3038 /* Now to look around and see what can be done */
3040 for (i=disks; i--; ) {
3045 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
3046 "written %p\n", i, dev->flags, dev->toread, dev->read,
3047 dev->towrite, dev->written);
3049 /* maybe we can request a biofill operation
3051 * new wantfill requests are only permitted while
3052 * ops_complete_biofill is guaranteed to be inactive
3054 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3055 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3056 set_bit(R5_Wantfill, &dev->flags);
3058 /* now count some things */
3059 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3060 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
3061 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
3063 if (test_bit(R5_Wantfill, &dev->flags))
3065 else if (dev->toread)
3069 if (!test_bit(R5_OVERWRITE, &dev->flags))
3074 rdev = rcu_dereference(conf->disks[i].rdev);
3075 if (blocked_rdev == NULL &&
3076 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3077 blocked_rdev = rdev;
3078 atomic_inc(&rdev->nr_pending);
3080 clear_bit(R5_Insync, &dev->flags);
3083 else if (test_bit(In_sync, &rdev->flags))
3084 set_bit(R5_Insync, &dev->flags);
3086 /* could be in-sync depending on recovery/reshape status */
3087 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3088 set_bit(R5_Insync, &dev->flags);
3090 if (!test_bit(R5_Insync, &dev->flags)) {
3091 /* The ReadError flag will just be confusing now */
3092 clear_bit(R5_ReadError, &dev->flags);
3093 clear_bit(R5_ReWrite, &dev->flags);
3095 if (test_bit(R5_ReadError, &dev->flags))
3096 clear_bit(R5_Insync, &dev->flags);
3097 if (!test_bit(R5_Insync, &dev->flags)) {
3104 if (unlikely(blocked_rdev)) {
3105 if (s.syncing || s.expanding || s.expanded ||
3106 s.to_write || s.written) {
3107 set_bit(STRIPE_HANDLE, &sh->state);
3110 /* There is nothing for the blocked_rdev to block */
3111 rdev_dec_pending(blocked_rdev, conf->mddev);
3112 blocked_rdev = NULL;
3115 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3116 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3117 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3120 pr_debug("locked=%d uptodate=%d to_read=%d"
3121 " to_write=%d failed=%d failed_num=%d\n",
3122 s.locked, s.uptodate, s.to_read, s.to_write,
3123 s.failed, s.failed_num);
3124 /* check if the array has lost two devices and, if so, some requests might
3127 if (s.failed > 1 && s.to_read+s.to_write+s.written)
3128 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
3129 if (s.failed > 1 && s.syncing) {
3130 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3131 clear_bit(STRIPE_SYNCING, &sh->state);
3135 /* might be able to return some write requests if the parity block
3136 * is safe, or on a failed drive
3138 dev = &sh->dev[sh->pd_idx];
3140 ((test_bit(R5_Insync, &dev->flags) &&
3141 !test_bit(R5_LOCKED, &dev->flags) &&
3142 test_bit(R5_UPTODATE, &dev->flags)) ||
3143 (s.failed == 1 && s.failed_num == sh->pd_idx)))
3144 handle_stripe_clean_event(conf, sh, disks, &return_bi);
3146 /* Now we might consider reading some blocks, either to check/generate
3147 * parity, or to satisfy requests
3148 * or to load a block that is being partially written.
3150 if (s.to_read || s.non_overwrite ||
3151 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
3152 handle_stripe_fill5(sh, &s, disks);
3154 /* Now we check to see if any write operations have recently
3158 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
3160 if (sh->reconstruct_state == reconstruct_state_drain_result ||
3161 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
3162 sh->reconstruct_state = reconstruct_state_idle;
3164 /* All the 'written' buffers and the parity block are ready to
3165 * be written back to disk
3167 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3168 for (i = disks; i--; ) {
3170 if (test_bit(R5_LOCKED, &dev->flags) &&
3171 (i == sh->pd_idx || dev->written)) {
3172 pr_debug("Writing block %d\n", i);
3173 set_bit(R5_Wantwrite, &dev->flags);
3176 if (!test_bit(R5_Insync, &dev->flags) ||
3177 (i == sh->pd_idx && s.failed == 0))
3178 set_bit(STRIPE_INSYNC, &sh->state);
3181 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3182 dec_preread_active = 1;
3185 /* Now to consider new write requests and what else, if anything
3186 * should be read. We do not handle new writes when:
3187 * 1/ A 'write' operation (copy+xor) is already in flight.
3188 * 2/ A 'check' operation is in flight, as it may clobber the parity
3191 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3192 handle_stripe_dirtying5(conf, sh, &s, disks);
3194 /* maybe we need to check and possibly fix the parity for this stripe
3195 * Any reads will already have been scheduled, so we just see if enough
3196 * data is available. The parity check is held off while parity
3197 * dependent operations are in flight.
3199 if (sh->check_state ||
3200 (s.syncing && s.locked == 0 &&
3201 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3202 !test_bit(STRIPE_INSYNC, &sh->state)))
3203 handle_parity_checks5(conf, sh, &s, disks);
3205 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3206 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3207 clear_bit(STRIPE_SYNCING, &sh->state);
3210 /* If the failed drive is just a ReadError, then we might need to progress
3211 * the repair/check process
3213 if (s.failed == 1 && !conf->mddev->ro &&
3214 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
3215 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
3216 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
3218 dev = &sh->dev[s.failed_num];
3219 if (!test_bit(R5_ReWrite, &dev->flags)) {
3220 set_bit(R5_Wantwrite, &dev->flags);
3221 set_bit(R5_ReWrite, &dev->flags);
3222 set_bit(R5_LOCKED, &dev->flags);
3225 /* let's read it back */
3226 set_bit(R5_Wantread, &dev->flags);
3227 set_bit(R5_LOCKED, &dev->flags);
3232 /* Finish reconstruct operations initiated by the expansion process */
3233 if (sh->reconstruct_state == reconstruct_state_result) {
3234 struct stripe_head *sh2
3235 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3236 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3237 /* sh cannot be written until sh2 has been read.
3238 * so arrange for sh to be delayed a little
3240 set_bit(STRIPE_DELAYED, &sh->state);
3241 set_bit(STRIPE_HANDLE, &sh->state);
3242 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3244 atomic_inc(&conf->preread_active_stripes);
3245 release_stripe(sh2);
3249 release_stripe(sh2);
3251 sh->reconstruct_state = reconstruct_state_idle;
3252 clear_bit(STRIPE_EXPANDING, &sh->state);
3253 for (i = conf->raid_disks; i--; ) {
3254 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3255 set_bit(R5_LOCKED, &sh->dev[i].flags);
3260 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3261 !sh->reconstruct_state) {
3262 /* Need to write out all blocks after computing parity */
3263 sh->disks = conf->raid_disks;
3264 stripe_set_idx(sh->sector, conf, 0, sh);
3265 schedule_reconstruction(sh, &s, 1, 1);
3266 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3267 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3268 atomic_dec(&conf->reshape_stripes);
3269 wake_up(&conf->wait_for_overlap);
3270 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3273 if (s.expanding && s.locked == 0 &&
3274 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3275 handle_stripe_expansion(conf, sh, NULL);
3278 spin_unlock(&sh->lock);
3280 /* wait for this device to become unblocked */
3281 if (unlikely(blocked_rdev))
3282 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3285 raid_run_ops(sh, s.ops_request);
3289 if (dec_preread_active) {
3290 /* We delay this until after ops_run_io so that if make_request
3291 * is waiting on a flush, it won't continue until the writes
3292 * have actually been submitted.
3294 atomic_dec(&conf->preread_active_stripes);
3295 if (atomic_read(&conf->preread_active_stripes) <
3297 md_wakeup_thread(conf->mddev->thread);
3299 return_io(return_bi);
3302 static void handle_stripe6(struct stripe_head *sh)
3304 raid5_conf_t *conf = sh->raid_conf;
3305 int disks = sh->disks;
3306 struct bio *return_bi = NULL;
3307 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
3308 struct stripe_head_state s;
3309 struct r6_state r6s;
3310 struct r5dev *dev, *pdev, *qdev;
3311 mdk_rdev_t *blocked_rdev = NULL;
3312 int dec_preread_active = 0;
3314 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3315 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3316 (unsigned long long)sh->sector, sh->state,
3317 atomic_read(&sh->count), pd_idx, qd_idx,
3318 sh->check_state, sh->reconstruct_state);
3319 memset(&s, 0, sizeof(s));
3321 spin_lock(&sh->lock);
3322 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
3323 set_bit(STRIPE_SYNCING, &sh->state);
3324 clear_bit(STRIPE_INSYNC, &sh->state);
3326 clear_bit(STRIPE_HANDLE, &sh->state);
3327 clear_bit(STRIPE_DELAYED, &sh->state);
3329 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3330 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3331 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3332 /* Now to look around and see what can be done */
3335 for (i=disks; i--; ) {
3339 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3340 i, dev->flags, dev->toread, dev->towrite, dev->written);
3341 /* maybe we can reply to a read
3343 * new wantfill requests are only permitted while
3344 * ops_complete_biofill is guaranteed to be inactive
3346 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
3347 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
3348 set_bit(R5_Wantfill, &dev->flags);
3350 /* now count some things */
3351 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3352 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
3353 if (test_bit(R5_Wantcompute, &dev->flags)) {
3355 BUG_ON(s.compute > 2);
3358 if (test_bit(R5_Wantfill, &dev->flags)) {
3360 } else if (dev->toread)
3364 if (!test_bit(R5_OVERWRITE, &dev->flags))
3369 rdev = rcu_dereference(conf->disks[i].rdev);
3370 if (blocked_rdev == NULL &&
3371 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3372 blocked_rdev = rdev;
3373 atomic_inc(&rdev->nr_pending);
3375 clear_bit(R5_Insync, &dev->flags);
3378 else if (test_bit(In_sync, &rdev->flags))
3379 set_bit(R5_Insync, &dev->flags);
3381 /* in sync if before recovery_offset */
3382 if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
3383 set_bit(R5_Insync, &dev->flags);
3385 if (!test_bit(R5_Insync, &dev->flags)) {
3386 /* The ReadError flag will just be confusing now */
3387 clear_bit(R5_ReadError, &dev->flags);
3388 clear_bit(R5_ReWrite, &dev->flags);
3390 if (test_bit(R5_ReadError, &dev->flags))
3391 clear_bit(R5_Insync, &dev->flags);
3392 if (!test_bit(R5_Insync, &dev->flags)) {
3394 r6s.failed_num[s.failed] = i;
3400 if (unlikely(blocked_rdev)) {
3401 if (s.syncing || s.expanding || s.expanded ||
3402 s.to_write || s.written) {
3403 set_bit(STRIPE_HANDLE, &sh->state);
3406 /* There is nothing for the blocked_rdev to block */
3407 rdev_dec_pending(blocked_rdev, conf->mddev);
3408 blocked_rdev = NULL;
3411 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
3412 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
3413 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
3416 pr_debug("locked=%d uptodate=%d to_read=%d"
3417 " to_write=%d failed=%d failed_num=%d,%d\n",
3418 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3419 r6s.failed_num[0], r6s.failed_num[1]);
3420 /* check if the array has lost >2 devices and, if so, some requests
3421 * might need to be failed
3423 if (s.failed > 2 && s.to_read+s.to_write+s.written)
3424 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
3425 if (s.failed > 2 && s.syncing) {
3426 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3427 clear_bit(STRIPE_SYNCING, &sh->state);
3432 * might be able to return some write requests if the parity blocks
3433 * are safe, or on a failed drive
3435 pdev = &sh->dev[pd_idx];
3436 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3437 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
3438 qdev = &sh->dev[qd_idx];
3439 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3440 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
3443 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3444 && !test_bit(R5_LOCKED, &pdev->flags)
3445 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3446 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3447 && !test_bit(R5_LOCKED, &qdev->flags)
3448 && test_bit(R5_UPTODATE, &qdev->flags)))))
3449 handle_stripe_clean_event(conf, sh, disks, &return_bi);
3451 /* Now we might consider reading some blocks, either to check/generate
3452 * parity, or to satisfy requests
3453 * or to load a block that is being partially written.
3455 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3456 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
3457 handle_stripe_fill6(sh, &s, &r6s, disks);
3459 /* Now we check to see if any write operations have recently
3462 if (sh->reconstruct_state == reconstruct_state_drain_result) {
3464 sh->reconstruct_state = reconstruct_state_idle;
3465 /* All the 'written' buffers and the parity blocks are ready to
3466 * be written back to disk
3468 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
3469 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
3470 for (i = disks; i--; ) {
3472 if (test_bit(R5_LOCKED, &dev->flags) &&
3473 (i == sh->pd_idx || i == qd_idx ||
3475 pr_debug("Writing block %d\n", i);
3476 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
3477 set_bit(R5_Wantwrite, &dev->flags);
3478 if (!test_bit(R5_Insync, &dev->flags) ||
3479 ((i == sh->pd_idx || i == qd_idx) &&
3481 set_bit(STRIPE_INSYNC, &sh->state);
3484 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3485 dec_preread_active = 1;
3488 /* Now to consider new write requests and what else, if anything
3489 * should be read. We do not handle new writes when:
3490 * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
3491 * 2/ A 'check' operation is in flight, as it may clobber the parity
3494 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
3495 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
3497 /* maybe we need to check and possibly fix the parity for this stripe
3498 * Any reads will already have been scheduled, so we just see if enough
3499 * data is available. The parity check is held off while parity
3500 * dependent operations are in flight.
3502 if (sh->check_state ||
3503 (s.syncing && s.locked == 0 &&
3504 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
3505 !test_bit(STRIPE_INSYNC, &sh->state)))
3506 handle_parity_checks6(conf, sh, &s, &r6s, disks);
3508 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3509 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3510 clear_bit(STRIPE_SYNCING, &sh->state);
3513 /* If the failed drives are just a ReadError, then we might need
3514 * to progress the repair/check process
3516 if (s.failed <= 2 && !conf->mddev->ro)
3517 for (i = 0; i < s.failed; i++) {
3518 dev = &sh->dev[r6s.failed_num[i]];
3519 if (test_bit(R5_ReadError, &dev->flags)
3520 && !test_bit(R5_LOCKED, &dev->flags)
3521 && test_bit(R5_UPTODATE, &dev->flags)
3523 if (!test_bit(R5_ReWrite, &dev->flags)) {
3524 set_bit(R5_Wantwrite, &dev->flags);
3525 set_bit(R5_ReWrite, &dev->flags);
3526 set_bit(R5_LOCKED, &dev->flags);
3529 /* let's read it back */
3530 set_bit(R5_Wantread, &dev->flags);
3531 set_bit(R5_LOCKED, &dev->flags);
3537 /* Finish reconstruct operations initiated by the expansion process */
3538 if (sh->reconstruct_state == reconstruct_state_result) {
3539 sh->reconstruct_state = reconstruct_state_idle;
3540 clear_bit(STRIPE_EXPANDING, &sh->state);
3541 for (i = conf->raid_disks; i--; ) {
3542 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3543 set_bit(R5_LOCKED, &sh->dev[i].flags);
3548 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
3549 !sh->reconstruct_state) {
3550 struct stripe_head *sh2
3551 = get_active_stripe(conf, sh->sector, 1, 1, 1);
3552 if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
3553 /* sh cannot be written until sh2 has been read.
3554 * so arrange for sh to be delayed a little
3556 set_bit(STRIPE_DELAYED, &sh->state);
3557 set_bit(STRIPE_HANDLE, &sh->state);
3558 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
3560 atomic_inc(&conf->preread_active_stripes);
3561 release_stripe(sh2);
3565 release_stripe(sh2);
3567 /* Need to write out all blocks after computing P&Q */
3568 sh->disks = conf->raid_disks;
3569 stripe_set_idx(sh->sector, conf, 0, sh);
3570 schedule_reconstruction(sh, &s, 1, 1);
3571 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
3572 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3573 atomic_dec(&conf->reshape_stripes);
3574 wake_up(&conf->wait_for_overlap);
3575 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3578 if (s.expanding && s.locked == 0 &&
3579 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3580 handle_stripe_expansion(conf, sh, &r6s);
3583 spin_unlock(&sh->lock);
3585 /* wait for this device to become unblocked */
3586 if (unlikely(blocked_rdev))
3587 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3590 raid_run_ops(sh, s.ops_request);
3595 if (dec_preread_active) {
3596 /* We delay this until after ops_run_io so that if make_request
3597 * is waiting on a flush, it won't continue until the writes
3598 * have actually been submitted.
3600 atomic_dec(&conf->preread_active_stripes);
3601 if (atomic_read(&conf->preread_active_stripes) <
3603 md_wakeup_thread(conf->mddev->thread);
3606 return_io(return_bi);
3609 static void handle_stripe(struct stripe_head *sh)
3611 if (sh->raid_conf->level == 6)
3617 static void raid5_activate_delayed(raid5_conf_t *conf)
3619 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3620 while (!list_empty(&conf->delayed_list)) {
3621 struct list_head *l = conf->delayed_list.next;
3622 struct stripe_head *sh;
3623 sh = list_entry(l, struct stripe_head, lru);
3625 clear_bit(STRIPE_DELAYED, &sh->state);
3626 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3627 atomic_inc(&conf->preread_active_stripes);
3628 list_add_tail(&sh->lru, &conf->hold_list);
3633 static void activate_bit_delay(raid5_conf_t *conf)
3635 /* device_lock is held */
3636 struct list_head head;
3637 list_add(&head, &conf->bitmap_list);
3638 list_del_init(&conf->bitmap_list);
3639 while (!list_empty(&head)) {
3640 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3641 list_del_init(&sh->lru);
3642 atomic_inc(&sh->count);
3643 __release_stripe(conf, sh);
3647 int md_raid5_congested(mddev_t *mddev, int bits)
3649 raid5_conf_t *conf = mddev->private;
3651 /* No difference between reads and writes. Just check
3652 * how busy the stripe_cache is
3655 if (conf->inactive_blocked)
3659 if (list_empty_careful(&conf->inactive_list))
3664 EXPORT_SYMBOL_GPL(md_raid5_congested);
3666 static int raid5_congested(void *data, int bits)
3668 mddev_t *mddev = data;
3670 return mddev_congested(mddev, bits) ||
3671 md_raid5_congested(mddev, bits);
3674 /* We want read requests to align with chunks where possible,
3675 * but write requests don't need to.
3677 static int raid5_mergeable_bvec(struct request_queue *q,
3678 struct bvec_merge_data *bvm,
3679 struct bio_vec *biovec)
3681 mddev_t *mddev = q->queuedata;
3682 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
3684 unsigned int chunk_sectors = mddev->chunk_sectors;
3685 unsigned int bio_sectors = bvm->bi_size >> 9;
3687 if ((bvm->bi_rw & 1) == WRITE)
3688 return biovec->bv_len; /* always allow writes to be mergeable */
3690 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3691 chunk_sectors = mddev->new_chunk_sectors;
3692 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3693 if (max < 0) max = 0;
3694 if (max <= biovec->bv_len && bio_sectors == 0)
3695 return biovec->bv_len;
3701 static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3703 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3704 unsigned int chunk_sectors = mddev->chunk_sectors;
3705 unsigned int bio_sectors = bio->bi_size >> 9;
3707 if (mddev->new_chunk_sectors < mddev->chunk_sectors)
3708 chunk_sectors = mddev->new_chunk_sectors;
3709 return chunk_sectors >=
3710 ((sector & (chunk_sectors - 1)) + bio_sectors);
3714 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3715 * later sampled by raid5d.
3717 static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3719 unsigned long flags;
3721 spin_lock_irqsave(&conf->device_lock, flags);
3723 bi->bi_next = conf->retry_read_aligned_list;
3724 conf->retry_read_aligned_list = bi;
3726 spin_unlock_irqrestore(&conf->device_lock, flags);
3727 md_wakeup_thread(conf->mddev->thread);
3731 static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3735 bi = conf->retry_read_aligned;
3737 conf->retry_read_aligned = NULL;
3740 bi = conf->retry_read_aligned_list;
3742 conf->retry_read_aligned_list = bi->bi_next;
3745 * this sets the active strip count to 1 and the processed
3746 * strip count to zero (upper 8 bits)
3748 bi->bi_phys_segments = 1; /* biased count of active stripes */
3756 * The "raid5_align_endio" should check if the read succeeded and if it
3757 * did, call bio_endio on the original bio (having bio_put the new bio
3759 * If the read failed..
3761 static void raid5_align_endio(struct bio *bi, int error)
3763 struct bio* raid_bi = bi->bi_private;
3766 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3771 rdev = (void*)raid_bi->bi_next;
3772 raid_bi->bi_next = NULL;
3773 mddev = rdev->mddev;
3774 conf = mddev->private;
3776 rdev_dec_pending(rdev, conf->mddev);
3778 if (!error && uptodate) {
3779 bio_endio(raid_bi, 0);
3780 if (atomic_dec_and_test(&conf->active_aligned_reads))
3781 wake_up(&conf->wait_for_stripe);
3786 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3788 add_bio_to_retry(raid_bi, conf);
3791 static int bio_fits_rdev(struct bio *bi)
3793 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
3795 if ((bi->bi_size>>9) > queue_max_sectors(q))
3797 blk_recount_segments(q, bi);
3798 if (bi->bi_phys_segments > queue_max_segments(q))
3801 if (q->merge_bvec_fn)
3802 /* it's too hard to apply the merge_bvec_fn at this stage,
3811 static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
3813 raid5_conf_t *conf = mddev->private;
3815 struct bio* align_bi;
3818 if (!in_chunk_boundary(mddev, raid_bio)) {
3819 pr_debug("chunk_aligned_read : non aligned\n");
3823 * use bio_clone_mddev to make a copy of the bio
3825 align_bi = bio_clone_mddev(raid_bio, GFP_NOIO, mddev);
3829 * set bi_end_io to a new function, and set bi_private to the
3832 align_bi->bi_end_io = raid5_align_endio;
3833 align_bi->bi_private = raid_bio;
3837 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3842 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3843 if (rdev && test_bit(In_sync, &rdev->flags)) {
3844 atomic_inc(&rdev->nr_pending);
3846 raid_bio->bi_next = (void*)rdev;
3847 align_bi->bi_bdev = rdev->bdev;
3848 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3849 align_bi->bi_sector += rdev->data_offset;
3851 if (!bio_fits_rdev(align_bi)) {
3852 /* too big in some way */
3854 rdev_dec_pending(rdev, mddev);
3858 spin_lock_irq(&conf->device_lock);
3859 wait_event_lock_irq(conf->wait_for_stripe,
3861 conf->device_lock, /* nothing */);
3862 atomic_inc(&conf->active_aligned_reads);
3863 spin_unlock_irq(&conf->device_lock);
3865 generic_make_request(align_bi);
3874 /* __get_priority_stripe - get the next stripe to process
3876 * Full stripe writes are allowed to pass preread active stripes up until
3877 * the bypass_threshold is exceeded. In general the bypass_count
3878 * increments when the handle_list is handled before the hold_list; however, it
3879 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3880 * stripe with in flight i/o. The bypass_count will be reset when the
3881 * head of the hold_list has changed, i.e. the head was promoted to the
3884 static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3886 struct stripe_head *sh;
3888 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3890 list_empty(&conf->handle_list) ? "empty" : "busy",
3891 list_empty(&conf->hold_list) ? "empty" : "busy",
3892 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3894 if (!list_empty(&conf->handle_list)) {
3895 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3897 if (list_empty(&conf->hold_list))
3898 conf->bypass_count = 0;
3899 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3900 if (conf->hold_list.next == conf->last_hold)
3901 conf->bypass_count++;
3903 conf->last_hold = conf->hold_list.next;
3904 conf->bypass_count -= conf->bypass_threshold;
3905 if (conf->bypass_count < 0)
3906 conf->bypass_count = 0;
3909 } else if (!list_empty(&conf->hold_list) &&
3910 ((conf->bypass_threshold &&
3911 conf->bypass_count > conf->bypass_threshold) ||
3912 atomic_read(&conf->pending_full_writes) == 0)) {
3913 sh = list_entry(conf->hold_list.next,
3915 conf->bypass_count -= conf->bypass_threshold;
3916 if (conf->bypass_count < 0)
3917 conf->bypass_count = 0;
3921 list_del_init(&sh->lru);
3922 atomic_inc(&sh->count);
3923 BUG_ON(atomic_read(&sh->count) != 1);
3927 static int make_request(mddev_t *mddev, struct bio * bi)
3929 raid5_conf_t *conf = mddev->private;
3931 sector_t new_sector;
3932 sector_t logical_sector, last_sector;
3933 struct stripe_head *sh;
3934 const int rw = bio_data_dir(bi);
3938 if (unlikely(bi->bi_rw & REQ_FLUSH)) {
3939 md_flush_request(mddev, bi);
3943 md_write_start(mddev, bi);
3946 mddev->reshape_position == MaxSector &&
3947 chunk_aligned_read(mddev,bi))
3950 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3951 last_sector = bi->bi_sector + (bi->bi_size>>9);
3953 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
3955 plugged = mddev_check_plugged(mddev);
3956 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3958 int disks, data_disks;
3963 disks = conf->raid_disks;
3964 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
3965 if (unlikely(conf->reshape_progress != MaxSector)) {
3966 /* spinlock is needed as reshape_progress may be
3967 * 64bit on a 32bit platform, and so it might be
3968 * possible to see a half-updated value
3969 * Of course reshape_progress could change after
3970 * the lock is dropped, so once we get a reference
3971 * to the stripe that we think it is, we will have
3974 spin_lock_irq(&conf->device_lock);
3975 if (mddev->delta_disks < 0
3976 ? logical_sector < conf->reshape_progress
3977 : logical_sector >= conf->reshape_progress) {
3978 disks = conf->previous_raid_disks;
3981 if (mddev->delta_disks < 0
3982 ? logical_sector < conf->reshape_safe
3983 : logical_sector >= conf->reshape_safe) {
3984 spin_unlock_irq(&conf->device_lock);
3989 spin_unlock_irq(&conf->device_lock);
3991 data_disks = disks - conf->max_degraded;
3993 new_sector = raid5_compute_sector(conf, logical_sector,
3996 pr_debug("raid456: make_request, sector %llu logical %llu\n",
3997 (unsigned long long)new_sector,
3998 (unsigned long long)logical_sector);
4000 sh = get_active_stripe(conf, new_sector, previous,
4001 (bi->bi_rw&RWA_MASK), 0);
4003 if (unlikely(previous)) {
4004 /* expansion might have moved on while waiting for a
4005 * stripe, so we must do the range check again.
4006 * Expansion could still move past after this
4007 * test, but as we are holding a reference to
4008 * 'sh', we know that if that happens,
4009 * STRIPE_EXPANDING will get set and the expansion
4010 * won't proceed until we finish with the stripe.
4013 spin_lock_irq(&conf->device_lock);
4014 if (mddev->delta_disks < 0
4015 ? logical_sector >= conf->reshape_progress
4016 : logical_sector < conf->reshape_progress)
4017 /* mismatch, need to try again */
4019 spin_unlock_irq(&conf->device_lock);
4028 logical_sector >= mddev->suspend_lo &&
4029 logical_sector < mddev->suspend_hi) {
4031 /* As the suspend_* range is controlled by
4032 * userspace, we want an interruptible
4035 flush_signals(current);
4036 prepare_to_wait(&conf->wait_for_overlap,
4037 &w, TASK_INTERRUPTIBLE);
4038 if (logical_sector >= mddev->suspend_lo &&
4039 logical_sector < mddev->suspend_hi)
4044 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
4045 !add_stripe_bio(sh, bi, dd_idx, rw)) {
4046 /* Stripe is busy expanding or
4047 * add failed due to overlap. Flush everything
4050 md_wakeup_thread(mddev->thread);
4055 finish_wait(&conf->wait_for_overlap, &w);
4056 set_bit(STRIPE_HANDLE, &sh->state);
4057 clear_bit(STRIPE_DELAYED, &sh->state);
4058 if ((bi->bi_rw & REQ_SYNC) &&
4059 !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
4060 atomic_inc(&conf->preread_active_stripes);
4063 /* cannot get stripe for read-ahead, just give-up */
4064 clear_bit(BIO_UPTODATE, &bi->bi_flags);
4065 finish_wait(&conf->wait_for_overlap, &w);
4071 md_wakeup_thread(mddev->thread);
4073 spin_lock_irq(&conf->device_lock);
4074 remaining = raid5_dec_bi_phys_segments(bi);
4075 spin_unlock_irq(&conf->device_lock);
4076 if (remaining == 0) {
4079 md_write_end(mddev);
4087 static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
4089 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
4091 /* reshaping is quite different to recovery/resync so it is
4092 * handled quite separately ... here.
4094 * On each call to sync_request, we gather one chunk worth of
4095 * destination stripes and flag them as expanding.
4096 * Then we find all the source stripes and request reads.
4097 * As the reads complete, handle_stripe will copy the data
4098 * into the destination stripe and release that stripe.
4100 raid5_conf_t *conf = mddev->private;
4101 struct stripe_head *sh;
4102 sector_t first_sector, last_sector;
4103 int raid_disks = conf->previous_raid_disks;
4104 int data_disks = raid_disks - conf->max_degraded;
4105 int new_data_disks = conf->raid_disks - conf->max_degraded;
4108 sector_t writepos, readpos, safepos;
4109 sector_t stripe_addr;
4110 int reshape_sectors;
4111 struct list_head stripes;
4113 if (sector_nr == 0) {
4114 /* If restarting in the middle, skip the initial sectors */
4115 if (mddev->delta_disks < 0 &&
4116 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
4117 sector_nr = raid5_size(mddev, 0, 0)
4118 - conf->reshape_progress;
4119 } else if (mddev->delta_disks >= 0 &&
4120 conf->reshape_progress > 0)
4121 sector_nr = conf->reshape_progress;
4122 sector_div(sector_nr, new_data_disks);
4124 mddev->curr_resync_completed = sector_nr;
4125 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4131 /* We need to process a full chunk at a time.
4132 * If old and new chunk sizes differ, we need to process the
4135 if (mddev->new_chunk_sectors > mddev->chunk_sectors)
4136 reshape_sectors = mddev->new_chunk_sectors;
4138 reshape_sectors = mddev->chunk_sectors;
4140 /* we update the metadata when there is more than 3Meg
4141 * in the block range (that is rather arbitrary, should
4142 * probably be time based) or when the data about to be
4143 * copied would over-write the source of the data at
4144 * the front of the range.
4145 * i.e. one new_stripe along from reshape_progress new_maps
4146 * to after where reshape_safe old_maps to
4148 writepos = conf->reshape_progress;
4149 sector_div(writepos, new_data_disks);
4150 readpos = conf->reshape_progress;
4151 sector_div(readpos, data_disks);
4152 safepos = conf->reshape_safe;
4153 sector_div(safepos, data_disks);
4154 if (mddev->delta_disks < 0) {
4155 writepos -= min_t(sector_t, reshape_sectors, writepos);
4156 readpos += reshape_sectors;
4157 safepos += reshape_sectors;
4159 writepos += reshape_sectors;
4160 readpos -= min_t(sector_t, reshape_sectors, readpos);
4161 safepos -= min_t(sector_t, reshape_sectors, safepos);
4164 /* 'writepos' is the most advanced device address we might write.
4165 * 'readpos' is the least advanced device address we might read.
4166 * 'safepos' is the least address recorded in the metadata as having
4168 * If 'readpos' is behind 'writepos', then there is no way that we can
4169 * ensure safety in the face of a crash - that must be done by userspace
4170 * making a backup of the data. So in that case there is no particular
4171 * rush to update metadata.
4172 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4173 * update the metadata to advance 'safepos' to match 'readpos' so that
4174 * we can be safe in the event of a crash.
4175 * So we insist on updating metadata if safepos is behind writepos and
4176 * readpos is beyond writepos.
4177 * In any case, update the metadata every 10 seconds.
4178 * Maybe that number should be configurable, but I'm not sure it is
4179 * worth it.... maybe it could be a multiple of safemode_delay???
4181 if ((mddev->delta_disks < 0
4182 ? (safepos > writepos && readpos < writepos)
4183 : (safepos < writepos && readpos > writepos)) ||
4184 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4185 /* Cannot proceed until we've updated the superblock... */
4186 wait_event(conf->wait_for_overlap,
4187 atomic_read(&conf->reshape_stripes)==0);
4188 mddev->reshape_position = conf->reshape_progress;
4189 mddev->curr_resync_completed = sector_nr;
4190 conf->reshape_checkpoint = jiffies;
4191 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4192 md_wakeup_thread(mddev->thread);
4193 wait_event(mddev->sb_wait, mddev->flags == 0 ||
4194 kthread_should_stop());
4195 spin_lock_irq(&conf->device_lock);
4196 conf->reshape_safe = mddev->reshape_position;
4197 spin_unlock_irq(&conf->device_lock);
4198 wake_up(&conf->wait_for_overlap);
4199 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4202 if (mddev->delta_disks < 0) {
4203 BUG_ON(conf->reshape_progress == 0);
4204 stripe_addr = writepos;
4205 BUG_ON((mddev->dev_sectors &
4206 ~((sector_t)reshape_sectors - 1))
4207 - reshape_sectors - stripe_addr
4210 BUG_ON(writepos != sector_nr + reshape_sectors);
4211 stripe_addr = sector_nr;
4213 INIT_LIST_HEAD(&stripes);
4214 for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) {
4216 int skipped_disk = 0;
4217 sh = get_active_stripe(conf, stripe_addr+i, 0, 0, 1);
4218 set_bit(STRIPE_EXPANDING, &sh->state);
4219 atomic_inc(&conf->reshape_stripes);
4220 /* If any of this stripe is beyond the end of the old
4221 * array, then we need to zero those blocks
4223 for (j=sh->disks; j--;) {
4225 if (j == sh->pd_idx)
4227 if (conf->level == 6 &&
4230 s = compute_blocknr(sh, j, 0);
4231 if (s < raid5_size(mddev, 0, 0)) {
4235 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
4236 set_bit(R5_Expanded, &sh->dev[j].flags);
4237 set_bit(R5_UPTODATE, &sh->dev[j].flags);
4239 if (!skipped_disk) {
4240 set_bit(STRIPE_EXPAND_READY, &sh->state);
4241 set_bit(STRIPE_HANDLE, &sh->state);
4243 list_add(&sh->lru, &stripes);
4245 spin_lock_irq(&conf->device_lock);
4246 if (mddev->delta_disks < 0)
4247 conf->reshape_progress -= reshape_sectors * new_data_disks;
4249 conf->reshape_progress += reshape_sectors * new_data_disks;
4250 spin_unlock_irq(&conf->device_lock);
4251 /* Ok, those stripe are ready. We can start scheduling
4252 * reads on the source stripes.
4253 * The source stripes are determined by mapping the first and last
4254 * block on the destination stripes.
4257 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
4260 raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
4261 * new_data_disks - 1),
4263 if (last_sector >= mddev->dev_sectors)
4264 last_sector = mddev->dev_sectors - 1;
4265 while (first_sector <= last_sector) {
4266 sh = get_active_stripe(conf, first_sector, 1, 0, 1);
4267 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
4268 set_bit(STRIPE_HANDLE, &sh->state);
4270 first_sector += STRIPE_SECTORS;
4272 /* Now that the sources are clearly marked, we can release
4273 * the destination stripes
4275 while (!list_empty(&stripes)) {
4276 sh = list_entry(stripes.next, struct stripe_head, lru);
4277 list_del_init(&sh->lru);
4280 /* If this takes us to the resync_max point where we have to pause,
4281 * then we need to write out the superblock.
4283 sector_nr += reshape_sectors;
4284 if ((sector_nr - mddev->curr_resync_completed) * 2
4285 >= mddev->resync_max - mddev->curr_resync_completed) {
4286 /* Cannot proceed until we've updated the superblock... */
4287 wait_event(conf->wait_for_overlap,
4288 atomic_read(&conf->reshape_stripes) == 0);
4289 mddev->reshape_position = conf->reshape_progress;
4290 mddev->curr_resync_completed = sector_nr;
4291 conf->reshape_checkpoint = jiffies;
4292 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4293 md_wakeup_thread(mddev->thread);
4294 wait_event(mddev->sb_wait,
4295 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
4296 || kthread_should_stop());
4297 spin_lock_irq(&conf->device_lock);
4298 conf->reshape_safe = mddev->reshape_position;
4299 spin_unlock_irq(&conf->device_lock);
4300 wake_up(&conf->wait_for_overlap);
4301 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4303 return reshape_sectors;
4306 /* FIXME go_faster isn't used */
4307 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
4309 raid5_conf_t *conf = mddev->private;
4310 struct stripe_head *sh;
4311 sector_t max_sector = mddev->dev_sectors;
4312 sector_t sync_blocks;
4313 int still_degraded = 0;
4316 if (sector_nr >= max_sector) {
4317 /* just being told to finish up .. nothing much to do */
4319 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
4324 if (mddev->curr_resync < max_sector) /* aborted */
4325 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
4327 else /* completed sync */
4329 bitmap_close_sync(mddev->bitmap);
4334 /* Allow raid5_quiesce to complete */
4335 wait_event(conf->wait_for_overlap, conf->quiesce != 2);
4337 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
4338 return reshape_request(mddev, sector_nr, skipped);
4340 /* No need to check resync_max as we never do more than one
4341 * stripe, and as resync_max will always be on a chunk boundary,
4342 * if the check in md_do_sync didn't fire, there is no chance
4343 * of overstepping resync_max here
4346 /* if there is too many failed drives and we are trying
4347 * to resync, then assert that we are finished, because there is
4348 * nothing we can do.
4350 if (mddev->degraded >= conf->max_degraded &&
4351 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
4352 sector_t rv = mddev->dev_sectors - sector_nr;
4356 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
4357 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
4358 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
4359 /* we can skip this block, and probably more */
4360 sync_blocks /= STRIPE_SECTORS;
4362 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
4366 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
4368 sh = get_active_stripe(conf, sector_nr, 0, 1, 0);
4370 sh = get_active_stripe(conf, sector_nr, 0, 0, 0);
4371 /* make sure we don't swamp the stripe cache if someone else
4372 * is trying to get access
4374 schedule_timeout_uninterruptible(1);
4376 /* Need to check if array will still be degraded after recovery/resync
4377 * We don't need to check the 'failed' flag as when that gets set,
4380 for (i = 0; i < conf->raid_disks; i++)
4381 if (conf->disks[i].rdev == NULL)
4384 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
4386 set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
4391 return STRIPE_SECTORS;
4394 static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
4396 /* We may not be able to submit a whole bio at once as there
4397 * may not be enough stripe_heads available.
4398 * We cannot pre-allocate enough stripe_heads as we may need
4399 * more than exist in the cache (if we allow ever large chunks).
4400 * So we do one stripe head at a time and record in
4401 * ->bi_hw_segments how many have been done.
4403 * We *know* that this entire raid_bio is in one chunk, so
4404 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4406 struct stripe_head *sh;
4408 sector_t sector, logical_sector, last_sector;
4413 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4414 sector = raid5_compute_sector(conf, logical_sector,
4416 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4418 for (; logical_sector < last_sector;
4419 logical_sector += STRIPE_SECTORS,
4420 sector += STRIPE_SECTORS,
4423 if (scnt < raid5_bi_hw_segments(raid_bio))
4424 /* already done this stripe */
4427 sh = get_active_stripe(conf, sector, 0, 1, 0);
4430 /* failed to get a stripe - must wait */
4431 raid5_set_bi_hw_segments(raid_bio, scnt);
4432 conf->retry_read_aligned = raid_bio;
4436 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
4437 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4439 raid5_set_bi_hw_segments(raid_bio, scnt);
4440 conf->retry_read_aligned = raid_bio;
4448 spin_lock_irq(&conf->device_lock);
4449 remaining = raid5_dec_bi_phys_segments(raid_bio);
4450 spin_unlock_irq(&conf->device_lock);
4452 bio_endio(raid_bio, 0);
4453 if (atomic_dec_and_test(&conf->active_aligned_reads))
4454 wake_up(&conf->wait_for_stripe);
4460 * This is our raid5 kernel thread.
4462 * We scan the hash table for stripes which can be handled now.
4463 * During the scan, completed stripes are saved for us by the interrupt
4464 * handler, so that they will not have to wait for our next wakeup.
4466 static void raid5d(mddev_t *mddev)
4468 struct stripe_head *sh;
4469 raid5_conf_t *conf = mddev->private;
4471 struct blk_plug plug;
4473 pr_debug("+++ raid5d active\n");
4475 md_check_recovery(mddev);
4477 blk_start_plug(&plug);
4479 spin_lock_irq(&conf->device_lock);
4483 if (atomic_read(&mddev->plug_cnt) == 0 &&
4484 !list_empty(&conf->bitmap_list)) {
4485 /* Now is a good time to flush some bitmap updates */
4487 spin_unlock_irq(&conf->device_lock);
4488 bitmap_unplug(mddev->bitmap);
4489 spin_lock_irq(&conf->device_lock);
4490 conf->seq_write = conf->seq_flush;
4491 activate_bit_delay(conf);
4493 if (atomic_read(&mddev->plug_cnt) == 0)
4494 raid5_activate_delayed(conf);
4496 while ((bio = remove_bio_from_retry(conf))) {
4498 spin_unlock_irq(&conf->device_lock);
4499 ok = retry_aligned_read(conf, bio);
4500 spin_lock_irq(&conf->device_lock);
4506 sh = __get_priority_stripe(conf);
4510 spin_unlock_irq(&conf->device_lock);
4517 spin_lock_irq(&conf->device_lock);
4519 pr_debug("%d stripes handled\n", handled);
4521 spin_unlock_irq(&conf->device_lock);
4523 async_tx_issue_pending_all();
4524 blk_finish_plug(&plug);
4526 pr_debug("--- raid5d inactive\n");
4530 raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
4532 raid5_conf_t *conf = mddev->private;
4534 return sprintf(page, "%d\n", conf->max_nr_stripes);
4540 raid5_set_cache_size(mddev_t *mddev, int size)
4542 raid5_conf_t *conf = mddev->private;
4545 if (size <= 16 || size > 32768)
4547 while (size < conf->max_nr_stripes) {
4548 if (drop_one_stripe(conf))
4549 conf->max_nr_stripes--;
4553 err = md_allow_write(mddev);
4556 while (size > conf->max_nr_stripes) {
4557 if (grow_one_stripe(conf))
4558 conf->max_nr_stripes++;
4563 EXPORT_SYMBOL(raid5_set_cache_size);
4566 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
4568 raid5_conf_t *conf = mddev->private;
4572 if (len >= PAGE_SIZE)
4577 if (strict_strtoul(page, 10, &new))
4579 err = raid5_set_cache_size(mddev, new);
4585 static struct md_sysfs_entry
4586 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4587 raid5_show_stripe_cache_size,
4588 raid5_store_stripe_cache_size);
4591 raid5_show_preread_threshold(mddev_t *mddev, char *page)
4593 raid5_conf_t *conf = mddev->private;
4595 return sprintf(page, "%d\n", conf->bypass_threshold);
4601 raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4603 raid5_conf_t *conf = mddev->private;
4605 if (len >= PAGE_SIZE)
4610 if (strict_strtoul(page, 10, &new))
4612 if (new > conf->max_nr_stripes)
4614 conf->bypass_threshold = new;
4618 static struct md_sysfs_entry
4619 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4621 raid5_show_preread_threshold,
4622 raid5_store_preread_threshold);
4625 stripe_cache_active_show(mddev_t *mddev, char *page)
4627 raid5_conf_t *conf = mddev->private;
4629 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4634 static struct md_sysfs_entry
4635 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
4637 static struct attribute *raid5_attrs[] = {
4638 &raid5_stripecache_size.attr,
4639 &raid5_stripecache_active.attr,
4640 &raid5_preread_bypass_threshold.attr,
4643 static struct attribute_group raid5_attrs_group = {
4645 .attrs = raid5_attrs,
4649 raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4651 raid5_conf_t *conf = mddev->private;
4654 sectors = mddev->dev_sectors;
4656 /* size is defined by the smallest of previous and new size */
4657 raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
4659 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
4660 sectors &= ~((sector_t)mddev->new_chunk_sectors - 1);
4661 return sectors * (raid_disks - conf->max_degraded);
4664 static void raid5_free_percpu(raid5_conf_t *conf)
4666 struct raid5_percpu *percpu;
4673 for_each_possible_cpu(cpu) {
4674 percpu = per_cpu_ptr(conf->percpu, cpu);
4675 safe_put_page(percpu->spare_page);
4676 kfree(percpu->scribble);
4678 #ifdef CONFIG_HOTPLUG_CPU
4679 unregister_cpu_notifier(&conf->cpu_notify);
4683 free_percpu(conf->percpu);
4686 static void free_conf(raid5_conf_t *conf)
4688 shrink_stripes(conf);
4689 raid5_free_percpu(conf);
4691 kfree(conf->stripe_hashtbl);
4695 #ifdef CONFIG_HOTPLUG_CPU
4696 static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action,
4699 raid5_conf_t *conf = container_of(nfb, raid5_conf_t, cpu_notify);
4700 long cpu = (long)hcpu;
4701 struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
4704 case CPU_UP_PREPARE:
4705 case CPU_UP_PREPARE_FROZEN:
4706 if (conf->level == 6 && !percpu->spare_page)
4707 percpu->spare_page = alloc_page(GFP_KERNEL);
4708 if (!percpu->scribble)
4709 percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4711 if (!percpu->scribble ||
4712 (conf->level == 6 && !percpu->spare_page)) {
4713 safe_put_page(percpu->spare_page);
4714 kfree(percpu->scribble);
4715 pr_err("%s: failed memory allocation for cpu%ld\n",
4717 return notifier_from_errno(-ENOMEM);
4721 case CPU_DEAD_FROZEN:
4722 safe_put_page(percpu->spare_page);
4723 kfree(percpu->scribble);
4724 percpu->spare_page = NULL;
4725 percpu->scribble = NULL;
4734 static int raid5_alloc_percpu(raid5_conf_t *conf)
4737 struct page *spare_page;
4738 struct raid5_percpu __percpu *allcpus;
4742 allcpus = alloc_percpu(struct raid5_percpu);
4745 conf->percpu = allcpus;
4749 for_each_present_cpu(cpu) {
4750 if (conf->level == 6) {
4751 spare_page = alloc_page(GFP_KERNEL);
4756 per_cpu_ptr(conf->percpu, cpu)->spare_page = spare_page;
4758 scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
4763 per_cpu_ptr(conf->percpu, cpu)->scribble = scribble;
4765 #ifdef CONFIG_HOTPLUG_CPU
4766 conf->cpu_notify.notifier_call = raid456_cpu_notify;
4767 conf->cpu_notify.priority = 0;
4769 err = register_cpu_notifier(&conf->cpu_notify);
4776 static raid5_conf_t *setup_conf(mddev_t *mddev)
4779 int raid_disk, memory, max_disks;
4781 struct disk_info *disk;
4783 if (mddev->new_level != 5
4784 && mddev->new_level != 4
4785 && mddev->new_level != 6) {
4786 printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4787 mdname(mddev), mddev->new_level);
4788 return ERR_PTR(-EIO);
4790 if ((mddev->new_level == 5
4791 && !algorithm_valid_raid5(mddev->new_layout)) ||
4792 (mddev->new_level == 6
4793 && !algorithm_valid_raid6(mddev->new_layout))) {
4794 printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
4795 mdname(mddev), mddev->new_layout);
4796 return ERR_PTR(-EIO);
4798 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
4799 printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4800 mdname(mddev), mddev->raid_disks);
4801 return ERR_PTR(-EINVAL);
4804 if (!mddev->new_chunk_sectors ||
4805 (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
4806 !is_power_of_2(mddev->new_chunk_sectors)) {
4807 printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
4808 mdname(mddev), mddev->new_chunk_sectors << 9);
4809 return ERR_PTR(-EINVAL);
4812 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4815 spin_lock_init(&conf->device_lock);
4816 init_waitqueue_head(&conf->wait_for_stripe);
4817 init_waitqueue_head(&conf->wait_for_overlap);
4818 INIT_LIST_HEAD(&conf->handle_list);
4819 INIT_LIST_HEAD(&conf->hold_list);
4820 INIT_LIST_HEAD(&conf->delayed_list);
4821 INIT_LIST_HEAD(&conf->bitmap_list);
4822 INIT_LIST_HEAD(&conf->inactive_list);
4823 atomic_set(&conf->active_stripes, 0);
4824 atomic_set(&conf->preread_active_stripes, 0);
4825 atomic_set(&conf->active_aligned_reads, 0);
4826 conf->bypass_threshold = BYPASS_THRESHOLD;
4828 conf->raid_disks = mddev->raid_disks;
4829 if (mddev->reshape_position == MaxSector)
4830 conf->previous_raid_disks = mddev->raid_disks;
4832 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4833 max_disks = max(conf->raid_disks, conf->previous_raid_disks);
4834 conf->scribble_len = scribble_len(max_disks);
4836 conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
4841 conf->mddev = mddev;
4843 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4846 conf->level = mddev->new_level;
4847 if (raid5_alloc_percpu(conf) != 0)
4850 pr_debug("raid456: run(%s) called.\n", mdname(mddev));
4852 list_for_each_entry(rdev, &mddev->disks, same_set) {
4853 raid_disk = rdev->raid_disk;
4854 if (raid_disk >= max_disks
4857 disk = conf->disks + raid_disk;
4861 if (test_bit(In_sync, &rdev->flags)) {
4862 char b[BDEVNAME_SIZE];
4863 printk(KERN_INFO "md/raid:%s: device %s operational as raid"
4865 mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
4866 } else if (rdev->saved_raid_disk != raid_disk)
4867 /* Cannot rely on bitmap to complete recovery */
4871 conf->chunk_sectors = mddev->new_chunk_sectors;
4872 conf->level = mddev->new_level;
4873 if (conf->level == 6)
4874 conf->max_degraded = 2;
4876 conf->max_degraded = 1;
4877 conf->algorithm = mddev->new_layout;
4878 conf->max_nr_stripes = NR_STRIPES;
4879 conf->reshape_progress = mddev->reshape_position;
4880 if (conf->reshape_progress != MaxSector) {
4881 conf->prev_chunk_sectors = mddev->chunk_sectors;
4882 conf->prev_algo = mddev->layout;
4885 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4886 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4887 if (grow_stripes(conf, conf->max_nr_stripes)) {
4889 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4890 mdname(mddev), memory);
4893 printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
4894 mdname(mddev), memory);
4896 conf->thread = md_register_thread(raid5d, mddev, NULL);
4897 if (!conf->thread) {
4899 "md/raid:%s: couldn't allocate thread.\n",
4909 return ERR_PTR(-EIO);
4911 return ERR_PTR(-ENOMEM);
4915 static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
4918 case ALGORITHM_PARITY_0:
4919 if (raid_disk < max_degraded)
4922 case ALGORITHM_PARITY_N:
4923 if (raid_disk >= raid_disks - max_degraded)
4926 case ALGORITHM_PARITY_0_6:
4927 if (raid_disk == 0 ||
4928 raid_disk == raid_disks - 1)
4931 case ALGORITHM_LEFT_ASYMMETRIC_6:
4932 case ALGORITHM_RIGHT_ASYMMETRIC_6:
4933 case ALGORITHM_LEFT_SYMMETRIC_6:
4934 case ALGORITHM_RIGHT_SYMMETRIC_6:
4935 if (raid_disk == raid_disks - 1)
4941 static int run(mddev_t *mddev)
4944 int working_disks = 0;
4945 int dirty_parity_disks = 0;
4947 sector_t reshape_offset = 0;
4949 if (mddev->recovery_cp != MaxSector)
4950 printk(KERN_NOTICE "md/raid:%s: not clean"
4951 " -- starting background reconstruction\n",
4953 if (mddev->reshape_position != MaxSector) {
4954 /* Check that we can continue the reshape.
4955 * Currently only disks can change, it must
4956 * increase, and we must be past the point where
4957 * a stripe over-writes itself
4959 sector_t here_new, here_old;
4961 int max_degraded = (mddev->level == 6 ? 2 : 1);
4963 if (mddev->new_level != mddev->level) {
4964 printk(KERN_ERR "md/raid:%s: unsupported reshape "
4965 "required - aborting.\n",
4969 old_disks = mddev->raid_disks - mddev->delta_disks;
4970 /* reshape_position must be on a new-stripe boundary, and one
4971 * further up in new geometry must map after here in old
4974 here_new = mddev->reshape_position;
4975 if (sector_div(here_new, mddev->new_chunk_sectors *
4976 (mddev->raid_disks - max_degraded))) {
4977 printk(KERN_ERR "md/raid:%s: reshape_position not "
4978 "on a stripe boundary\n", mdname(mddev));
4981 reshape_offset = here_new * mddev->new_chunk_sectors;
4982 /* here_new is the stripe we will write to */
4983 here_old = mddev->reshape_position;
4984 sector_div(here_old, mddev->chunk_sectors *
4985 (old_disks-max_degraded));
4986 /* here_old is the first stripe that we might need to read
4988 if (mddev->delta_disks == 0) {
4989 /* We cannot be sure it is safe to start an in-place
4990 * reshape. It is only safe if user-space if monitoring
4991 * and taking constant backups.
4992 * mdadm always starts a situation like this in
4993 * readonly mode so it can take control before
4994 * allowing any writes. So just check for that.
4996 if ((here_new * mddev->new_chunk_sectors !=
4997 here_old * mddev->chunk_sectors) ||
4999 printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
5000 " in read-only mode - aborting\n",
5004 } else if (mddev->delta_disks < 0
5005 ? (here_new * mddev->new_chunk_sectors <=
5006 here_old * mddev->chunk_sectors)
5007 : (here_new * mddev->new_chunk_sectors >=
5008 here_old * mddev->chunk_sectors)) {
5009 /* Reading from the same stripe as writing to - bad */
5010 printk(KERN_ERR "md/raid:%s: reshape_position too early for "
5011 "auto-recovery - aborting.\n",
5015 printk(KERN_INFO "md/raid:%s: reshape will continue\n",
5017 /* OK, we should be able to continue; */
5019 BUG_ON(mddev->level != mddev->new_level);
5020 BUG_ON(mddev->layout != mddev->new_layout);
5021 BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
5022 BUG_ON(mddev->delta_disks != 0);
5025 if (mddev->private == NULL)
5026 conf = setup_conf(mddev);
5028 conf = mddev->private;
5031 return PTR_ERR(conf);
5033 mddev->thread = conf->thread;
5034 conf->thread = NULL;
5035 mddev->private = conf;
5038 * 0 for a fully functional array, 1 or 2 for a degraded array.
5040 list_for_each_entry(rdev, &mddev->disks, same_set) {
5041 if (rdev->raid_disk < 0)
5043 if (test_bit(In_sync, &rdev->flags)) {
5047 /* This disc is not fully in-sync. However if it
5048 * just stored parity (beyond the recovery_offset),
5049 * when we don't need to be concerned about the
5050 * array being dirty.
5051 * When reshape goes 'backwards', we never have
5052 * partially completed devices, so we only need
5053 * to worry about reshape going forwards.
5055 /* Hack because v0.91 doesn't store recovery_offset properly. */
5056 if (mddev->major_version == 0 &&
5057 mddev->minor_version > 90)
5058 rdev->recovery_offset = reshape_offset;
5060 if (rdev->recovery_offset < reshape_offset) {
5061 /* We need to check old and new layout */
5062 if (!only_parity(rdev->raid_disk,
5065 conf->max_degraded))
5068 if (!only_parity(rdev->raid_disk,
5070 conf->previous_raid_disks,
5071 conf->max_degraded))
5073 dirty_parity_disks++;
5076 mddev->degraded = (max(conf->raid_disks, conf->previous_raid_disks)
5079 if (has_failed(conf)) {
5080 printk(KERN_ERR "md/raid:%s: not enough operational devices"
5081 " (%d/%d failed)\n",
5082 mdname(mddev), mddev->degraded, conf->raid_disks);
5086 /* device size must be a multiple of chunk size */
5087 mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
5088 mddev->resync_max_sectors = mddev->dev_sectors;
5090 if (mddev->degraded > dirty_parity_disks &&
5091 mddev->recovery_cp != MaxSector) {
5092 if (mddev->ok_start_degraded)
5094 "md/raid:%s: starting dirty degraded array"
5095 " - data corruption possible.\n",
5099 "md/raid:%s: cannot start dirty degraded array.\n",
5105 if (mddev->degraded == 0)
5106 printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
5107 " devices, algorithm %d\n", mdname(mddev), conf->level,
5108 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
5111 printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
5112 " out of %d devices, algorithm %d\n",
5113 mdname(mddev), conf->level,
5114 mddev->raid_disks - mddev->degraded,
5115 mddev->raid_disks, mddev->new_layout);
5117 print_raid5_conf(conf);
5119 if (conf->reshape_progress != MaxSector) {
5120 conf->reshape_safe = conf->reshape_progress;
5121 atomic_set(&conf->reshape_stripes, 0);
5122 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5123 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5124 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5125 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5126 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5131 /* Ok, everything is just fine now */
5132 if (mddev->to_remove == &raid5_attrs_group)
5133 mddev->to_remove = NULL;
5134 else if (mddev->kobj.sd &&
5135 sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
5137 "raid5: failed to create sysfs attributes for %s\n",
5139 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5143 /* read-ahead size must cover two whole stripes, which
5144 * is 2 * (datadisks) * chunksize where 'n' is the
5145 * number of raid devices
5147 int data_disks = conf->previous_raid_disks - conf->max_degraded;
5148 int stripe = data_disks *
5149 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
5150 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5151 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5153 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
5155 mddev->queue->backing_dev_info.congested_data = mddev;
5156 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
5158 chunk_size = mddev->chunk_sectors << 9;
5159 blk_queue_io_min(mddev->queue, chunk_size);
5160 blk_queue_io_opt(mddev->queue, chunk_size *
5161 (conf->raid_disks - conf->max_degraded));
5163 list_for_each_entry(rdev, &mddev->disks, same_set)
5164 disk_stack_limits(mddev->gendisk, rdev->bdev,
5165 rdev->data_offset << 9);
5170 md_unregister_thread(mddev->thread);
5171 mddev->thread = NULL;
5173 print_raid5_conf(conf);
5176 mddev->private = NULL;
5177 printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
5181 static int stop(mddev_t *mddev)
5183 raid5_conf_t *conf = mddev->private;
5185 md_unregister_thread(mddev->thread);
5186 mddev->thread = NULL;
5188 mddev->queue->backing_dev_info.congested_fn = NULL;
5190 mddev->private = NULL;
5191 mddev->to_remove = &raid5_attrs_group;
5196 static void print_sh(struct seq_file *seq, struct stripe_head *sh)
5200 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
5201 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
5202 seq_printf(seq, "sh %llu, count %d.\n",
5203 (unsigned long long)sh->sector, atomic_read(&sh->count));
5204 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
5205 for (i = 0; i < sh->disks; i++) {
5206 seq_printf(seq, "(cache%d: %p %ld) ",
5207 i, sh->dev[i].page, sh->dev[i].flags);
5209 seq_printf(seq, "\n");
5212 static void printall(struct seq_file *seq, raid5_conf_t *conf)
5214 struct stripe_head *sh;
5215 struct hlist_node *hn;
5218 spin_lock_irq(&conf->device_lock);
5219 for (i = 0; i < NR_HASH; i++) {
5220 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
5221 if (sh->raid_conf != conf)
5226 spin_unlock_irq(&conf->device_lock);
5230 static void status(struct seq_file *seq, mddev_t *mddev)
5232 raid5_conf_t *conf = mddev->private;
5235 seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
5236 mddev->chunk_sectors / 2, mddev->layout);
5237 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
5238 for (i = 0; i < conf->raid_disks; i++)
5239 seq_printf (seq, "%s",
5240 conf->disks[i].rdev &&
5241 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
5242 seq_printf (seq, "]");
5244 seq_printf (seq, "\n");
5245 printall(seq, conf);
5249 static void print_raid5_conf (raid5_conf_t *conf)
5252 struct disk_info *tmp;
5254 printk(KERN_DEBUG "RAID conf printout:\n");
5256 printk("(conf==NULL)\n");
5259 printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
5261 conf->raid_disks - conf->mddev->degraded);
5263 for (i = 0; i < conf->raid_disks; i++) {
5264 char b[BDEVNAME_SIZE];
5265 tmp = conf->disks + i;
5267 printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
5268 i, !test_bit(Faulty, &tmp->rdev->flags),
5269 bdevname(tmp->rdev->bdev, b));
5273 static int raid5_spare_active(mddev_t *mddev)
5276 raid5_conf_t *conf = mddev->private;
5277 struct disk_info *tmp;
5279 unsigned long flags;
5281 for (i = 0; i < conf->raid_disks; i++) {
5282 tmp = conf->disks + i;
5284 && tmp->rdev->recovery_offset == MaxSector
5285 && !test_bit(Faulty, &tmp->rdev->flags)
5286 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
5288 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
5291 spin_lock_irqsave(&conf->device_lock, flags);
5292 mddev->degraded -= count;
5293 spin_unlock_irqrestore(&conf->device_lock, flags);
5294 print_raid5_conf(conf);
5298 static int raid5_remove_disk(mddev_t *mddev, int number)
5300 raid5_conf_t *conf = mddev->private;
5303 struct disk_info *p = conf->disks + number;
5305 print_raid5_conf(conf);
5308 if (number >= conf->raid_disks &&
5309 conf->reshape_progress == MaxSector)
5310 clear_bit(In_sync, &rdev->flags);
5312 if (test_bit(In_sync, &rdev->flags) ||
5313 atomic_read(&rdev->nr_pending)) {
5317 /* Only remove non-faulty devices if recovery
5320 if (!test_bit(Faulty, &rdev->flags) &&
5321 !has_failed(conf) &&
5322 number < conf->raid_disks) {
5328 if (atomic_read(&rdev->nr_pending)) {
5329 /* lost the race, try later */
5336 print_raid5_conf(conf);
5340 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
5342 raid5_conf_t *conf = mddev->private;
5345 struct disk_info *p;
5347 int last = conf->raid_disks - 1;
5349 if (has_failed(conf))
5350 /* no point adding a device */
5353 if (rdev->raid_disk >= 0)
5354 first = last = rdev->raid_disk;
5357 * find the disk ... but prefer rdev->saved_raid_disk
5360 if (rdev->saved_raid_disk >= 0 &&
5361 rdev->saved_raid_disk >= first &&
5362 conf->disks[rdev->saved_raid_disk].rdev == NULL)
5363 disk = rdev->saved_raid_disk;
5366 for ( ; disk <= last ; disk++)
5367 if ((p=conf->disks + disk)->rdev == NULL) {
5368 clear_bit(In_sync, &rdev->flags);
5369 rdev->raid_disk = disk;
5371 if (rdev->saved_raid_disk != disk)
5373 rcu_assign_pointer(p->rdev, rdev);
5376 print_raid5_conf(conf);
5380 static int raid5_resize(mddev_t *mddev, sector_t sectors)
5382 /* no resync is happening, and there is enough space
5383 * on all devices, so we can resize.
5384 * We need to make sure resync covers any new space.
5385 * If the array is shrinking we should possibly wait until
5386 * any io in the removed space completes, but it hardly seems
5389 sectors &= ~((sector_t)mddev->chunk_sectors - 1);
5390 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
5391 mddev->raid_disks));
5392 if (mddev->array_sectors >
5393 raid5_size(mddev, sectors, mddev->raid_disks))
5395 set_capacity(mddev->gendisk, mddev->array_sectors);
5396 revalidate_disk(mddev->gendisk);
5397 if (sectors > mddev->dev_sectors &&
5398 mddev->recovery_cp > mddev->dev_sectors) {
5399 mddev->recovery_cp = mddev->dev_sectors;
5400 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
5402 mddev->dev_sectors = sectors;
5403 mddev->resync_max_sectors = sectors;
5407 static int check_stripe_cache(mddev_t *mddev)
5409 /* Can only proceed if there are plenty of stripe_heads.
5410 * We need a minimum of one full stripe,, and for sensible progress
5411 * it is best to have about 4 times that.
5412 * If we require 4 times, then the default 256 4K stripe_heads will
5413 * allow for chunk sizes up to 256K, which is probably OK.
5414 * If the chunk size is greater, user-space should request more
5415 * stripe_heads first.
5417 raid5_conf_t *conf = mddev->private;
5418 if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4
5419 > conf->max_nr_stripes ||
5420 ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
5421 > conf->max_nr_stripes) {
5422 printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5424 ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
5431 static int check_reshape(mddev_t *mddev)
5433 raid5_conf_t *conf = mddev->private;
5435 if (mddev->delta_disks == 0 &&
5436 mddev->new_layout == mddev->layout &&
5437 mddev->new_chunk_sectors == mddev->chunk_sectors)
5438 return 0; /* nothing to do */
5440 /* Cannot grow a bitmap yet */
5442 if (has_failed(conf))
5444 if (mddev->delta_disks < 0) {
5445 /* We might be able to shrink, but the devices must
5446 * be made bigger first.
5447 * For raid6, 4 is the minimum size.
5448 * Otherwise 2 is the minimum
5451 if (mddev->level == 6)
5453 if (mddev->raid_disks + mddev->delta_disks < min)
5457 if (!check_stripe_cache(mddev))
5460 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
5463 static int raid5_start_reshape(mddev_t *mddev)
5465 raid5_conf_t *conf = mddev->private;
5468 unsigned long flags;
5470 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5473 if (!check_stripe_cache(mddev))
5476 list_for_each_entry(rdev, &mddev->disks, same_set)
5477 if (!test_bit(In_sync, &rdev->flags)
5478 && !test_bit(Faulty, &rdev->flags))
5481 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
5482 /* Not enough devices even to make a degraded array
5487 /* Refuse to reduce size of the array. Any reductions in
5488 * array size must be through explicit setting of array_size
5491 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
5492 < mddev->array_sectors) {
5493 printk(KERN_ERR "md/raid:%s: array size must be reduced "
5494 "before number of disks\n", mdname(mddev));
5498 atomic_set(&conf->reshape_stripes, 0);
5499 spin_lock_irq(&conf->device_lock);
5500 conf->previous_raid_disks = conf->raid_disks;
5501 conf->raid_disks += mddev->delta_disks;
5502 conf->prev_chunk_sectors = conf->chunk_sectors;
5503 conf->chunk_sectors = mddev->new_chunk_sectors;
5504 conf->prev_algo = conf->algorithm;
5505 conf->algorithm = mddev->new_layout;
5506 if (mddev->delta_disks < 0)
5507 conf->reshape_progress = raid5_size(mddev, 0, 0);
5509 conf->reshape_progress = 0;
5510 conf->reshape_safe = conf->reshape_progress;
5512 spin_unlock_irq(&conf->device_lock);
5514 /* Add some new drives, as many as will fit.
5515 * We know there are enough to make the newly sized array work.
5516 * Don't add devices if we are reducing the number of
5517 * devices in the array. This is because it is not possible
5518 * to correctly record the "partially reconstructed" state of
5519 * such devices during the reshape and confusion could result.
5521 if (mddev->delta_disks >= 0) {
5522 int added_devices = 0;
5523 list_for_each_entry(rdev, &mddev->disks, same_set)
5524 if (rdev->raid_disk < 0 &&
5525 !test_bit(Faulty, &rdev->flags)) {
5526 if (raid5_add_disk(mddev, rdev) == 0) {
5529 >= conf->previous_raid_disks) {
5530 set_bit(In_sync, &rdev->flags);
5533 rdev->recovery_offset = 0;
5534 sprintf(nm, "rd%d", rdev->raid_disk);
5535 if (sysfs_create_link(&mddev->kobj,
5537 /* Failure here is OK */;
5539 } else if (rdev->raid_disk >= conf->previous_raid_disks
5540 && !test_bit(Faulty, &rdev->flags)) {
5541 /* This is a spare that was manually added */
5542 set_bit(In_sync, &rdev->flags);
5546 /* When a reshape changes the number of devices,
5547 * ->degraded is measured against the larger of the
5548 * pre and post number of devices.
5550 spin_lock_irqsave(&conf->device_lock, flags);
5551 mddev->degraded += (conf->raid_disks - conf->previous_raid_disks)
5553 spin_unlock_irqrestore(&conf->device_lock, flags);
5555 mddev->raid_disks = conf->raid_disks;
5556 mddev->reshape_position = conf->reshape_progress;
5557 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5559 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
5560 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
5561 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
5562 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
5563 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
5565 if (!mddev->sync_thread) {
5566 mddev->recovery = 0;
5567 spin_lock_irq(&conf->device_lock);
5568 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
5569 conf->reshape_progress = MaxSector;
5570 spin_unlock_irq(&conf->device_lock);
5573 conf->reshape_checkpoint = jiffies;
5574 md_wakeup_thread(mddev->sync_thread);
5575 md_new_event(mddev);
5579 /* This is called from the reshape thread and should make any
5580 * changes needed in 'conf'
5582 static void end_reshape(raid5_conf_t *conf)
5585 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
5587 spin_lock_irq(&conf->device_lock);
5588 conf->previous_raid_disks = conf->raid_disks;
5589 conf->reshape_progress = MaxSector;
5590 spin_unlock_irq(&conf->device_lock);
5591 wake_up(&conf->wait_for_overlap);
5593 /* read-ahead size must cover two whole stripes, which is
5594 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5596 if (conf->mddev->queue) {
5597 int data_disks = conf->raid_disks - conf->max_degraded;
5598 int stripe = data_disks * ((conf->chunk_sectors << 9)
5600 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
5601 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
5606 /* This is called from the raid5d thread with mddev_lock held.
5607 * It makes config changes to the device.
5609 static void raid5_finish_reshape(mddev_t *mddev)
5611 raid5_conf_t *conf = mddev->private;
5613 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
5615 if (mddev->delta_disks > 0) {
5616 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
5617 set_capacity(mddev->gendisk, mddev->array_sectors);
5618 revalidate_disk(mddev->gendisk);
5621 mddev->degraded = conf->raid_disks;
5622 for (d = 0; d < conf->raid_disks ; d++)
5623 if (conf->disks[d].rdev &&
5625 &conf->disks[d].rdev->flags))
5627 for (d = conf->raid_disks ;
5628 d < conf->raid_disks - mddev->delta_disks;
5630 mdk_rdev_t *rdev = conf->disks[d].rdev;
5631 if (rdev && raid5_remove_disk(mddev, d) == 0) {
5633 sprintf(nm, "rd%d", rdev->raid_disk);
5634 sysfs_remove_link(&mddev->kobj, nm);
5635 rdev->raid_disk = -1;
5639 mddev->layout = conf->algorithm;
5640 mddev->chunk_sectors = conf->chunk_sectors;
5641 mddev->reshape_position = MaxSector;
5642 mddev->delta_disks = 0;
5646 static void raid5_quiesce(mddev_t *mddev, int state)
5648 raid5_conf_t *conf = mddev->private;
5651 case 2: /* resume for a suspend */
5652 wake_up(&conf->wait_for_overlap);
5655 case 1: /* stop all writes */
5656 spin_lock_irq(&conf->device_lock);
5657 /* '2' tells resync/reshape to pause so that all
5658 * active stripes can drain
5661 wait_event_lock_irq(conf->wait_for_stripe,
5662 atomic_read(&conf->active_stripes) == 0 &&
5663 atomic_read(&conf->active_aligned_reads) == 0,
5664 conf->device_lock, /* nothing */);
5666 spin_unlock_irq(&conf->device_lock);
5667 /* allow reshape to continue */
5668 wake_up(&conf->wait_for_overlap);
5671 case 0: /* re-enable writes */
5672 spin_lock_irq(&conf->device_lock);
5674 wake_up(&conf->wait_for_stripe);
5675 wake_up(&conf->wait_for_overlap);
5676 spin_unlock_irq(&conf->device_lock);
5682 static void *raid45_takeover_raid0(mddev_t *mddev, int level)
5684 struct raid0_private_data *raid0_priv = mddev->private;
5687 /* for raid0 takeover only one zone is supported */
5688 if (raid0_priv->nr_strip_zones > 1) {
5689 printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5691 return ERR_PTR(-EINVAL);
5694 sectors = raid0_priv->strip_zone[0].zone_end;
5695 sector_div(sectors, raid0_priv->strip_zone[0].nb_dev);
5696 mddev->dev_sectors = sectors;
5697 mddev->new_level = level;
5698 mddev->new_layout = ALGORITHM_PARITY_N;
5699 mddev->new_chunk_sectors = mddev->chunk_sectors;
5700 mddev->raid_disks += 1;
5701 mddev->delta_disks = 1;
5702 /* make sure it will be not marked as dirty */
5703 mddev->recovery_cp = MaxSector;
5705 return setup_conf(mddev);
5709 static void *raid5_takeover_raid1(mddev_t *mddev)
5713 if (mddev->raid_disks != 2 ||
5714 mddev->degraded > 1)
5715 return ERR_PTR(-EINVAL);
5717 /* Should check if there are write-behind devices? */
5719 chunksect = 64*2; /* 64K by default */
5721 /* The array must be an exact multiple of chunksize */
5722 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5725 if ((chunksect<<9) < STRIPE_SIZE)
5726 /* array size does not allow a suitable chunk size */
5727 return ERR_PTR(-EINVAL);
5729 mddev->new_level = 5;
5730 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
5731 mddev->new_chunk_sectors = chunksect;
5733 return setup_conf(mddev);
5736 static void *raid5_takeover_raid6(mddev_t *mddev)
5740 switch (mddev->layout) {
5741 case ALGORITHM_LEFT_ASYMMETRIC_6:
5742 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5744 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5745 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5747 case ALGORITHM_LEFT_SYMMETRIC_6:
5748 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5750 case ALGORITHM_RIGHT_SYMMETRIC_6:
5751 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5753 case ALGORITHM_PARITY_0_6:
5754 new_layout = ALGORITHM_PARITY_0;
5756 case ALGORITHM_PARITY_N:
5757 new_layout = ALGORITHM_PARITY_N;
5760 return ERR_PTR(-EINVAL);
5762 mddev->new_level = 5;
5763 mddev->new_layout = new_layout;
5764 mddev->delta_disks = -1;
5765 mddev->raid_disks -= 1;
5766 return setup_conf(mddev);
5770 static int raid5_check_reshape(mddev_t *mddev)
5772 /* For a 2-drive array, the layout and chunk size can be changed
5773 * immediately as not restriping is needed.
5774 * For larger arrays we record the new value - after validation
5775 * to be used by a reshape pass.
5777 raid5_conf_t *conf = mddev->private;
5778 int new_chunk = mddev->new_chunk_sectors;
5780 if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
5782 if (new_chunk > 0) {
5783 if (!is_power_of_2(new_chunk))
5785 if (new_chunk < (PAGE_SIZE>>9))
5787 if (mddev->array_sectors & (new_chunk-1))
5788 /* not factor of array size */
5792 /* They look valid */
5794 if (mddev->raid_disks == 2) {
5795 /* can make the change immediately */
5796 if (mddev->new_layout >= 0) {
5797 conf->algorithm = mddev->new_layout;
5798 mddev->layout = mddev->new_layout;
5800 if (new_chunk > 0) {
5801 conf->chunk_sectors = new_chunk ;
5802 mddev->chunk_sectors = new_chunk;
5804 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5805 md_wakeup_thread(mddev->thread);
5807 return check_reshape(mddev);
5810 static int raid6_check_reshape(mddev_t *mddev)
5812 int new_chunk = mddev->new_chunk_sectors;
5814 if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
5816 if (new_chunk > 0) {
5817 if (!is_power_of_2(new_chunk))
5819 if (new_chunk < (PAGE_SIZE >> 9))
5821 if (mddev->array_sectors & (new_chunk-1))
5822 /* not factor of array size */
5826 /* They look valid */
5827 return check_reshape(mddev);
5830 static void *raid5_takeover(mddev_t *mddev)
5832 /* raid5 can take over:
5833 * raid0 - if there is only one strip zone - make it a raid4 layout
5834 * raid1 - if there are two drives. We need to know the chunk size
5835 * raid4 - trivial - just use a raid4 layout.
5836 * raid6 - Providing it is a *_6 layout
5838 if (mddev->level == 0)
5839 return raid45_takeover_raid0(mddev, 5);
5840 if (mddev->level == 1)
5841 return raid5_takeover_raid1(mddev);
5842 if (mddev->level == 4) {
5843 mddev->new_layout = ALGORITHM_PARITY_N;
5844 mddev->new_level = 5;
5845 return setup_conf(mddev);
5847 if (mddev->level == 6)
5848 return raid5_takeover_raid6(mddev);
5850 return ERR_PTR(-EINVAL);
5853 static void *raid4_takeover(mddev_t *mddev)
5855 /* raid4 can take over:
5856 * raid0 - if there is only one strip zone
5857 * raid5 - if layout is right
5859 if (mddev->level == 0)
5860 return raid45_takeover_raid0(mddev, 4);
5861 if (mddev->level == 5 &&
5862 mddev->layout == ALGORITHM_PARITY_N) {
5863 mddev->new_layout = 0;
5864 mddev->new_level = 4;
5865 return setup_conf(mddev);
5867 return ERR_PTR(-EINVAL);
5870 static struct mdk_personality raid5_personality;
5872 static void *raid6_takeover(mddev_t *mddev)
5874 /* Currently can only take over a raid5. We map the
5875 * personality to an equivalent raid6 personality
5876 * with the Q block at the end.
5880 if (mddev->pers != &raid5_personality)
5881 return ERR_PTR(-EINVAL);
5882 if (mddev->degraded > 1)
5883 return ERR_PTR(-EINVAL);
5884 if (mddev->raid_disks > 253)
5885 return ERR_PTR(-EINVAL);
5886 if (mddev->raid_disks < 3)
5887 return ERR_PTR(-EINVAL);
5889 switch (mddev->layout) {
5890 case ALGORITHM_LEFT_ASYMMETRIC:
5891 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5893 case ALGORITHM_RIGHT_ASYMMETRIC:
5894 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5896 case ALGORITHM_LEFT_SYMMETRIC:
5897 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5899 case ALGORITHM_RIGHT_SYMMETRIC:
5900 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5902 case ALGORITHM_PARITY_0:
5903 new_layout = ALGORITHM_PARITY_0_6;
5905 case ALGORITHM_PARITY_N:
5906 new_layout = ALGORITHM_PARITY_N;
5909 return ERR_PTR(-EINVAL);
5911 mddev->new_level = 6;
5912 mddev->new_layout = new_layout;
5913 mddev->delta_disks = 1;
5914 mddev->raid_disks += 1;
5915 return setup_conf(mddev);
5919 static struct mdk_personality raid6_personality =
5923 .owner = THIS_MODULE,
5924 .make_request = make_request,
5928 .error_handler = error,
5929 .hot_add_disk = raid5_add_disk,
5930 .hot_remove_disk= raid5_remove_disk,
5931 .spare_active = raid5_spare_active,
5932 .sync_request = sync_request,
5933 .resize = raid5_resize,
5935 .check_reshape = raid6_check_reshape,
5936 .start_reshape = raid5_start_reshape,
5937 .finish_reshape = raid5_finish_reshape,
5938 .quiesce = raid5_quiesce,
5939 .takeover = raid6_takeover,
5941 static struct mdk_personality raid5_personality =
5945 .owner = THIS_MODULE,
5946 .make_request = make_request,
5950 .error_handler = error,
5951 .hot_add_disk = raid5_add_disk,
5952 .hot_remove_disk= raid5_remove_disk,
5953 .spare_active = raid5_spare_active,
5954 .sync_request = sync_request,
5955 .resize = raid5_resize,
5957 .check_reshape = raid5_check_reshape,
5958 .start_reshape = raid5_start_reshape,
5959 .finish_reshape = raid5_finish_reshape,
5960 .quiesce = raid5_quiesce,
5961 .takeover = raid5_takeover,
5964 static struct mdk_personality raid4_personality =
5968 .owner = THIS_MODULE,
5969 .make_request = make_request,
5973 .error_handler = error,
5974 .hot_add_disk = raid5_add_disk,
5975 .hot_remove_disk= raid5_remove_disk,
5976 .spare_active = raid5_spare_active,
5977 .sync_request = sync_request,
5978 .resize = raid5_resize,
5980 .check_reshape = raid5_check_reshape,
5981 .start_reshape = raid5_start_reshape,
5982 .finish_reshape = raid5_finish_reshape,
5983 .quiesce = raid5_quiesce,
5984 .takeover = raid4_takeover,
5987 static int __init raid5_init(void)
5989 register_md_personality(&raid6_personality);
5990 register_md_personality(&raid5_personality);
5991 register_md_personality(&raid4_personality);
5995 static void raid5_exit(void)
5997 unregister_md_personality(&raid6_personality);
5998 unregister_md_personality(&raid5_personality);
5999 unregister_md_personality(&raid4_personality);
6002 module_init(raid5_init);
6003 module_exit(raid5_exit);
6004 MODULE_LICENSE("GPL");
6005 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6006 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6007 MODULE_ALIAS("md-raid5");
6008 MODULE_ALIAS("md-raid4");
6009 MODULE_ALIAS("md-level-5");
6010 MODULE_ALIAS("md-level-4");
6011 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6012 MODULE_ALIAS("md-raid6");
6013 MODULE_ALIAS("md-level-6");
6015 /* This used to be two separate modules, they were: */
6016 MODULE_ALIAS("raid5");
6017 MODULE_ALIAS("raid6");