2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->bm_write is the number of the last batch successfully written.
31 * conf->bm_flush is the number of the last batch that was closed to
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is bm_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/seq_file.h>
59 #define NR_STRIPES 256
60 #define STRIPE_SIZE PAGE_SIZE
61 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
62 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
63 #define IO_THRESHOLD 1
64 #define BYPASS_THRESHOLD 1
65 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
66 #define HASH_MASK (NR_HASH - 1)
68 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
70 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
71 * order without overlap. There may be several bio's per stripe+device, and
72 * a bio could span several devices.
73 * When walking this list for a particular stripe+device, we must never proceed
74 * beyond a bio that extends past this device, as the next bio might no longer
76 * This macro is used to determine the 'next' bio in the list, given the sector
77 * of the current stripe+device
79 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
81 * The following can be used to debug the driver
83 #define RAID5_PARANOIA 1
84 #if RAID5_PARANOIA && defined(CONFIG_SMP)
85 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
87 # define CHECK_DEVLOCK()
95 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
98 * We maintain a biased count of active stripes in the bottom 16 bits of
99 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
101 static inline int raid5_bi_phys_segments(struct bio *bio)
103 return bio->bi_phys_segments & 0xffff;
106 static inline int raid5_bi_hw_segments(struct bio *bio)
108 return (bio->bi_phys_segments >> 16) & 0xffff;
111 static inline int raid5_dec_bi_phys_segments(struct bio *bio)
113 --bio->bi_phys_segments;
114 return raid5_bi_phys_segments(bio);
117 static inline int raid5_dec_bi_hw_segments(struct bio *bio)
119 unsigned short val = raid5_bi_hw_segments(bio);
122 bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
126 static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
128 bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
131 /* Find first data disk in a raid6 stripe */
132 static inline int raid6_d0(struct stripe_head *sh)
135 /* ddf always start from first device */
137 /* md starts just after Q block */
138 if (sh->qd_idx == sh->disks - 1)
141 return sh->qd_idx + 1;
143 static inline int raid6_next_disk(int disk, int raid_disks)
146 return (disk < raid_disks) ? disk : 0;
149 /* When walking through the disks in a raid5, starting at raid6_d0,
150 * We need to map each disk to a 'slot', where the data disks are slot
151 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
152 * is raid_disks-1. This help does that mapping.
154 static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
155 int *count, int syndrome_disks)
159 if (idx == sh->pd_idx)
160 return syndrome_disks;
161 if (idx == sh->qd_idx)
162 return syndrome_disks + 1;
167 static void return_io(struct bio *return_bi)
169 struct bio *bi = return_bi;
172 return_bi = bi->bi_next;
180 static void print_raid5_conf (raid5_conf_t *conf);
182 static int stripe_operations_active(struct stripe_head *sh)
184 return sh->check_state || sh->reconstruct_state ||
185 test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
186 test_bit(STRIPE_COMPUTE_RUN, &sh->state);
189 static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
191 if (atomic_dec_and_test(&sh->count)) {
192 BUG_ON(!list_empty(&sh->lru));
193 BUG_ON(atomic_read(&conf->active_stripes)==0);
194 if (test_bit(STRIPE_HANDLE, &sh->state)) {
195 if (test_bit(STRIPE_DELAYED, &sh->state)) {
196 list_add_tail(&sh->lru, &conf->delayed_list);
197 blk_plug_device(conf->mddev->queue);
198 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
199 sh->bm_seq - conf->seq_write > 0) {
200 list_add_tail(&sh->lru, &conf->bitmap_list);
201 blk_plug_device(conf->mddev->queue);
203 clear_bit(STRIPE_BIT_DELAY, &sh->state);
204 list_add_tail(&sh->lru, &conf->handle_list);
206 md_wakeup_thread(conf->mddev->thread);
208 BUG_ON(stripe_operations_active(sh));
209 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
210 atomic_dec(&conf->preread_active_stripes);
211 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
212 md_wakeup_thread(conf->mddev->thread);
214 atomic_dec(&conf->active_stripes);
215 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
216 list_add_tail(&sh->lru, &conf->inactive_list);
217 wake_up(&conf->wait_for_stripe);
218 if (conf->retry_read_aligned)
219 md_wakeup_thread(conf->mddev->thread);
225 static void release_stripe(struct stripe_head *sh)
227 raid5_conf_t *conf = sh->raid_conf;
230 spin_lock_irqsave(&conf->device_lock, flags);
231 __release_stripe(conf, sh);
232 spin_unlock_irqrestore(&conf->device_lock, flags);
235 static inline void remove_hash(struct stripe_head *sh)
237 pr_debug("remove_hash(), stripe %llu\n",
238 (unsigned long long)sh->sector);
240 hlist_del_init(&sh->hash);
243 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
245 struct hlist_head *hp = stripe_hash(conf, sh->sector);
247 pr_debug("insert_hash(), stripe %llu\n",
248 (unsigned long long)sh->sector);
251 hlist_add_head(&sh->hash, hp);
255 /* find an idle stripe, make sure it is unhashed, and return it. */
256 static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
258 struct stripe_head *sh = NULL;
259 struct list_head *first;
262 if (list_empty(&conf->inactive_list))
264 first = conf->inactive_list.next;
265 sh = list_entry(first, struct stripe_head, lru);
266 list_del_init(first);
268 atomic_inc(&conf->active_stripes);
273 static void shrink_buffers(struct stripe_head *sh, int num)
278 for (i=0; i<num ; i++) {
282 sh->dev[i].page = NULL;
287 static int grow_buffers(struct stripe_head *sh, int num)
291 for (i=0; i<num; i++) {
294 if (!(page = alloc_page(GFP_KERNEL))) {
297 sh->dev[i].page = page;
302 static void raid5_build_block(struct stripe_head *sh, int i, int previous);
303 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
304 struct stripe_head *sh);
306 static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
308 raid5_conf_t *conf = sh->raid_conf;
311 BUG_ON(atomic_read(&sh->count) != 0);
312 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
313 BUG_ON(stripe_operations_active(sh));
316 pr_debug("init_stripe called, stripe %llu\n",
317 (unsigned long long)sh->sector);
321 sh->generation = conf->generation - previous;
322 sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
324 stripe_set_idx(sector, conf, previous, sh);
328 for (i = sh->disks; i--; ) {
329 struct r5dev *dev = &sh->dev[i];
331 if (dev->toread || dev->read || dev->towrite || dev->written ||
332 test_bit(R5_LOCKED, &dev->flags)) {
333 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
334 (unsigned long long)sh->sector, i, dev->toread,
335 dev->read, dev->towrite, dev->written,
336 test_bit(R5_LOCKED, &dev->flags));
340 raid5_build_block(sh, i, previous);
342 insert_hash(conf, sh);
345 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector,
348 struct stripe_head *sh;
349 struct hlist_node *hn;
352 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
353 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
354 if (sh->sector == sector && sh->generation == generation)
356 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
360 static void unplug_slaves(mddev_t *mddev);
361 static void raid5_unplug_device(struct request_queue *q);
363 static struct stripe_head *
364 get_active_stripe(raid5_conf_t *conf, sector_t sector,
365 int previous, int noblock)
367 struct stripe_head *sh;
369 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
371 spin_lock_irq(&conf->device_lock);
374 wait_event_lock_irq(conf->wait_for_stripe,
376 conf->device_lock, /* nothing */);
377 sh = __find_stripe(conf, sector, conf->generation - previous);
379 if (!conf->inactive_blocked)
380 sh = get_free_stripe(conf);
381 if (noblock && sh == NULL)
384 conf->inactive_blocked = 1;
385 wait_event_lock_irq(conf->wait_for_stripe,
386 !list_empty(&conf->inactive_list) &&
387 (atomic_read(&conf->active_stripes)
388 < (conf->max_nr_stripes *3/4)
389 || !conf->inactive_blocked),
391 raid5_unplug_device(conf->mddev->queue)
393 conf->inactive_blocked = 0;
395 init_stripe(sh, sector, previous);
397 if (atomic_read(&sh->count)) {
398 BUG_ON(!list_empty(&sh->lru));
400 if (!test_bit(STRIPE_HANDLE, &sh->state))
401 atomic_inc(&conf->active_stripes);
402 if (list_empty(&sh->lru) &&
403 !test_bit(STRIPE_EXPANDING, &sh->state))
405 list_del_init(&sh->lru);
408 } while (sh == NULL);
411 atomic_inc(&sh->count);
413 spin_unlock_irq(&conf->device_lock);
418 raid5_end_read_request(struct bio *bi, int error);
420 raid5_end_write_request(struct bio *bi, int error);
422 static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
424 raid5_conf_t *conf = sh->raid_conf;
425 int i, disks = sh->disks;
429 for (i = disks; i--; ) {
433 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
435 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
440 bi = &sh->dev[i].req;
444 bi->bi_end_io = raid5_end_write_request;
446 bi->bi_end_io = raid5_end_read_request;
449 rdev = rcu_dereference(conf->disks[i].rdev);
450 if (rdev && test_bit(Faulty, &rdev->flags))
453 atomic_inc(&rdev->nr_pending);
457 if (s->syncing || s->expanding || s->expanded)
458 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
460 set_bit(STRIPE_IO_STARTED, &sh->state);
462 bi->bi_bdev = rdev->bdev;
463 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
464 __func__, (unsigned long long)sh->sector,
466 atomic_inc(&sh->count);
467 bi->bi_sector = sh->sector + rdev->data_offset;
468 bi->bi_flags = 1 << BIO_UPTODATE;
472 bi->bi_io_vec = &sh->dev[i].vec;
473 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
474 bi->bi_io_vec[0].bv_offset = 0;
475 bi->bi_size = STRIPE_SIZE;
478 test_bit(R5_ReWrite, &sh->dev[i].flags))
479 atomic_add(STRIPE_SECTORS,
480 &rdev->corrected_errors);
481 generic_make_request(bi);
484 set_bit(STRIPE_DEGRADED, &sh->state);
485 pr_debug("skip op %ld on disc %d for sector %llu\n",
486 bi->bi_rw, i, (unsigned long long)sh->sector);
487 clear_bit(R5_LOCKED, &sh->dev[i].flags);
488 set_bit(STRIPE_HANDLE, &sh->state);
493 static struct dma_async_tx_descriptor *
494 async_copy_data(int frombio, struct bio *bio, struct page *page,
495 sector_t sector, struct dma_async_tx_descriptor *tx)
498 struct page *bio_page;
502 if (bio->bi_sector >= sector)
503 page_offset = (signed)(bio->bi_sector - sector) * 512;
505 page_offset = (signed)(sector - bio->bi_sector) * -512;
506 bio_for_each_segment(bvl, bio, i) {
507 int len = bio_iovec_idx(bio, i)->bv_len;
511 if (page_offset < 0) {
512 b_offset = -page_offset;
513 page_offset += b_offset;
517 if (len > 0 && page_offset + len > STRIPE_SIZE)
518 clen = STRIPE_SIZE - page_offset;
523 b_offset += bio_iovec_idx(bio, i)->bv_offset;
524 bio_page = bio_iovec_idx(bio, i)->bv_page;
526 tx = async_memcpy(page, bio_page, page_offset,
531 tx = async_memcpy(bio_page, page, b_offset,
536 if (clen < len) /* hit end of page */
544 static void ops_complete_biofill(void *stripe_head_ref)
546 struct stripe_head *sh = stripe_head_ref;
547 struct bio *return_bi = NULL;
548 raid5_conf_t *conf = sh->raid_conf;
551 pr_debug("%s: stripe %llu\n", __func__,
552 (unsigned long long)sh->sector);
554 /* clear completed biofills */
555 spin_lock_irq(&conf->device_lock);
556 for (i = sh->disks; i--; ) {
557 struct r5dev *dev = &sh->dev[i];
559 /* acknowledge completion of a biofill operation */
560 /* and check if we need to reply to a read request,
561 * new R5_Wantfill requests are held off until
562 * !STRIPE_BIOFILL_RUN
564 if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
565 struct bio *rbi, *rbi2;
570 while (rbi && rbi->bi_sector <
571 dev->sector + STRIPE_SECTORS) {
572 rbi2 = r5_next_bio(rbi, dev->sector);
573 if (!raid5_dec_bi_phys_segments(rbi)) {
574 rbi->bi_next = return_bi;
581 spin_unlock_irq(&conf->device_lock);
582 clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
584 return_io(return_bi);
586 set_bit(STRIPE_HANDLE, &sh->state);
590 static void ops_run_biofill(struct stripe_head *sh)
592 struct dma_async_tx_descriptor *tx = NULL;
593 raid5_conf_t *conf = sh->raid_conf;
596 pr_debug("%s: stripe %llu\n", __func__,
597 (unsigned long long)sh->sector);
599 for (i = sh->disks; i--; ) {
600 struct r5dev *dev = &sh->dev[i];
601 if (test_bit(R5_Wantfill, &dev->flags)) {
603 spin_lock_irq(&conf->device_lock);
604 dev->read = rbi = dev->toread;
606 spin_unlock_irq(&conf->device_lock);
607 while (rbi && rbi->bi_sector <
608 dev->sector + STRIPE_SECTORS) {
609 tx = async_copy_data(0, rbi, dev->page,
611 rbi = r5_next_bio(rbi, dev->sector);
616 atomic_inc(&sh->count);
617 async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
618 ops_complete_biofill, sh);
621 static void ops_complete_compute5(void *stripe_head_ref)
623 struct stripe_head *sh = stripe_head_ref;
624 int target = sh->ops.target;
625 struct r5dev *tgt = &sh->dev[target];
627 pr_debug("%s: stripe %llu\n", __func__,
628 (unsigned long long)sh->sector);
630 set_bit(R5_UPTODATE, &tgt->flags);
631 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
632 clear_bit(R5_Wantcompute, &tgt->flags);
633 clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
634 if (sh->check_state == check_state_compute_run)
635 sh->check_state = check_state_compute_result;
636 set_bit(STRIPE_HANDLE, &sh->state);
640 static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh)
642 /* kernel stack size limits the total number of disks */
643 int disks = sh->disks;
644 struct page *xor_srcs[disks];
645 int target = sh->ops.target;
646 struct r5dev *tgt = &sh->dev[target];
647 struct page *xor_dest = tgt->page;
649 struct dma_async_tx_descriptor *tx;
652 pr_debug("%s: stripe %llu block: %d\n",
653 __func__, (unsigned long long)sh->sector, target);
654 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
656 for (i = disks; i--; )
658 xor_srcs[count++] = sh->dev[i].page;
660 atomic_inc(&sh->count);
662 if (unlikely(count == 1))
663 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
664 0, NULL, ops_complete_compute5, sh);
666 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
667 ASYNC_TX_XOR_ZERO_DST, NULL,
668 ops_complete_compute5, sh);
673 static void ops_complete_prexor(void *stripe_head_ref)
675 struct stripe_head *sh = stripe_head_ref;
677 pr_debug("%s: stripe %llu\n", __func__,
678 (unsigned long long)sh->sector);
681 static struct dma_async_tx_descriptor *
682 ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
684 /* kernel stack size limits the total number of disks */
685 int disks = sh->disks;
686 struct page *xor_srcs[disks];
687 int count = 0, pd_idx = sh->pd_idx, i;
689 /* existing parity data subtracted */
690 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
692 pr_debug("%s: stripe %llu\n", __func__,
693 (unsigned long long)sh->sector);
695 for (i = disks; i--; ) {
696 struct r5dev *dev = &sh->dev[i];
697 /* Only process blocks that are known to be uptodate */
698 if (test_bit(R5_Wantdrain, &dev->flags))
699 xor_srcs[count++] = dev->page;
702 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
703 ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
704 ops_complete_prexor, sh);
709 static struct dma_async_tx_descriptor *
710 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
712 int disks = sh->disks;
715 pr_debug("%s: stripe %llu\n", __func__,
716 (unsigned long long)sh->sector);
718 for (i = disks; i--; ) {
719 struct r5dev *dev = &sh->dev[i];
722 if (test_and_clear_bit(R5_Wantdrain, &dev->flags)) {
725 spin_lock(&sh->lock);
726 chosen = dev->towrite;
728 BUG_ON(dev->written);
729 wbi = dev->written = chosen;
730 spin_unlock(&sh->lock);
732 while (wbi && wbi->bi_sector <
733 dev->sector + STRIPE_SECTORS) {
734 tx = async_copy_data(1, wbi, dev->page,
736 wbi = r5_next_bio(wbi, dev->sector);
744 static void ops_complete_postxor(void *stripe_head_ref)
746 struct stripe_head *sh = stripe_head_ref;
747 int disks = sh->disks, i, pd_idx = sh->pd_idx;
749 pr_debug("%s: stripe %llu\n", __func__,
750 (unsigned long long)sh->sector);
752 for (i = disks; i--; ) {
753 struct r5dev *dev = &sh->dev[i];
754 if (dev->written || i == pd_idx)
755 set_bit(R5_UPTODATE, &dev->flags);
758 if (sh->reconstruct_state == reconstruct_state_drain_run)
759 sh->reconstruct_state = reconstruct_state_drain_result;
760 else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
761 sh->reconstruct_state = reconstruct_state_prexor_drain_result;
763 BUG_ON(sh->reconstruct_state != reconstruct_state_run);
764 sh->reconstruct_state = reconstruct_state_result;
767 set_bit(STRIPE_HANDLE, &sh->state);
772 ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
774 /* kernel stack size limits the total number of disks */
775 int disks = sh->disks;
776 struct page *xor_srcs[disks];
778 int count = 0, pd_idx = sh->pd_idx, i;
779 struct page *xor_dest;
783 pr_debug("%s: stripe %llu\n", __func__,
784 (unsigned long long)sh->sector);
786 /* check if prexor is active which means only process blocks
787 * that are part of a read-modify-write (written)
789 if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
791 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
792 for (i = disks; i--; ) {
793 struct r5dev *dev = &sh->dev[i];
795 xor_srcs[count++] = dev->page;
798 xor_dest = sh->dev[pd_idx].page;
799 for (i = disks; i--; ) {
800 struct r5dev *dev = &sh->dev[i];
802 xor_srcs[count++] = dev->page;
806 /* 1/ if we prexor'd then the dest is reused as a source
807 * 2/ if we did not prexor then we are redoing the parity
808 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
809 * for the synchronous xor case
811 flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
812 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
814 atomic_inc(&sh->count);
816 if (unlikely(count == 1)) {
817 flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
818 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
819 flags, tx, ops_complete_postxor, sh);
821 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
822 flags, tx, ops_complete_postxor, sh);
825 static void ops_complete_check(void *stripe_head_ref)
827 struct stripe_head *sh = stripe_head_ref;
829 pr_debug("%s: stripe %llu\n", __func__,
830 (unsigned long long)sh->sector);
832 sh->check_state = check_state_check_result;
833 set_bit(STRIPE_HANDLE, &sh->state);
837 static void ops_run_check(struct stripe_head *sh)
839 /* kernel stack size limits the total number of disks */
840 int disks = sh->disks;
841 struct page *xor_srcs[disks];
842 struct dma_async_tx_descriptor *tx;
844 int count = 0, pd_idx = sh->pd_idx, i;
845 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
847 pr_debug("%s: stripe %llu\n", __func__,
848 (unsigned long long)sh->sector);
850 for (i = disks; i--; ) {
851 struct r5dev *dev = &sh->dev[i];
853 xor_srcs[count++] = dev->page;
856 tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
857 &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
859 atomic_inc(&sh->count);
860 tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
861 ops_complete_check, sh);
864 static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
866 int overlap_clear = 0, i, disks = sh->disks;
867 struct dma_async_tx_descriptor *tx = NULL;
869 if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
874 if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
875 tx = ops_run_compute5(sh);
876 /* terminate the chain if postxor is not set to be run */
877 if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request))
881 if (test_bit(STRIPE_OP_PREXOR, &ops_request))
882 tx = ops_run_prexor(sh, tx);
884 if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
885 tx = ops_run_biodrain(sh, tx);
889 if (test_bit(STRIPE_OP_POSTXOR, &ops_request))
890 ops_run_postxor(sh, tx);
892 if (test_bit(STRIPE_OP_CHECK, &ops_request))
896 for (i = disks; i--; ) {
897 struct r5dev *dev = &sh->dev[i];
898 if (test_and_clear_bit(R5_Overlap, &dev->flags))
899 wake_up(&sh->raid_conf->wait_for_overlap);
903 static int grow_one_stripe(raid5_conf_t *conf)
905 struct stripe_head *sh;
906 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
909 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
910 sh->raid_conf = conf;
911 spin_lock_init(&sh->lock);
913 if (grow_buffers(sh, conf->raid_disks)) {
914 shrink_buffers(sh, conf->raid_disks);
915 kmem_cache_free(conf->slab_cache, sh);
918 sh->disks = conf->raid_disks;
919 /* we just created an active stripe so... */
920 atomic_set(&sh->count, 1);
921 atomic_inc(&conf->active_stripes);
922 INIT_LIST_HEAD(&sh->lru);
927 static int grow_stripes(raid5_conf_t *conf, int num)
929 struct kmem_cache *sc;
930 int devs = conf->raid_disks;
932 sprintf(conf->cache_name[0],
933 "raid%d-%s", conf->level, mdname(conf->mddev));
934 sprintf(conf->cache_name[1],
935 "raid%d-%s-alt", conf->level, mdname(conf->mddev));
936 conf->active_name = 0;
937 sc = kmem_cache_create(conf->cache_name[conf->active_name],
938 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
942 conf->slab_cache = sc;
943 conf->pool_size = devs;
945 if (!grow_one_stripe(conf))
950 #ifdef CONFIG_MD_RAID5_RESHAPE
951 static int resize_stripes(raid5_conf_t *conf, int newsize)
953 /* Make all the stripes able to hold 'newsize' devices.
954 * New slots in each stripe get 'page' set to a new page.
956 * This happens in stages:
957 * 1/ create a new kmem_cache and allocate the required number of
959 * 2/ gather all the old stripe_heads and tranfer the pages across
960 * to the new stripe_heads. This will have the side effect of
961 * freezing the array as once all stripe_heads have been collected,
962 * no IO will be possible. Old stripe heads are freed once their
963 * pages have been transferred over, and the old kmem_cache is
964 * freed when all stripes are done.
965 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
966 * we simple return a failre status - no need to clean anything up.
967 * 4/ allocate new pages for the new slots in the new stripe_heads.
968 * If this fails, we don't bother trying the shrink the
969 * stripe_heads down again, we just leave them as they are.
970 * As each stripe_head is processed the new one is released into
973 * Once step2 is started, we cannot afford to wait for a write,
974 * so we use GFP_NOIO allocations.
976 struct stripe_head *osh, *nsh;
977 LIST_HEAD(newstripes);
978 struct disk_info *ndisks;
980 struct kmem_cache *sc;
983 if (newsize <= conf->pool_size)
984 return 0; /* never bother to shrink */
986 err = md_allow_write(conf->mddev);
991 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
992 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
997 for (i = conf->max_nr_stripes; i; i--) {
998 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1002 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1004 nsh->raid_conf = conf;
1005 spin_lock_init(&nsh->lock);
1007 list_add(&nsh->lru, &newstripes);
1010 /* didn't get enough, give up */
1011 while (!list_empty(&newstripes)) {
1012 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1013 list_del(&nsh->lru);
1014 kmem_cache_free(sc, nsh);
1016 kmem_cache_destroy(sc);
1019 /* Step 2 - Must use GFP_NOIO now.
1020 * OK, we have enough stripes, start collecting inactive
1021 * stripes and copying them over
1023 list_for_each_entry(nsh, &newstripes, lru) {
1024 spin_lock_irq(&conf->device_lock);
1025 wait_event_lock_irq(conf->wait_for_stripe,
1026 !list_empty(&conf->inactive_list),
1028 unplug_slaves(conf->mddev)
1030 osh = get_free_stripe(conf);
1031 spin_unlock_irq(&conf->device_lock);
1032 atomic_set(&nsh->count, 1);
1033 for(i=0; i<conf->pool_size; i++)
1034 nsh->dev[i].page = osh->dev[i].page;
1035 for( ; i<newsize; i++)
1036 nsh->dev[i].page = NULL;
1037 kmem_cache_free(conf->slab_cache, osh);
1039 kmem_cache_destroy(conf->slab_cache);
1042 * At this point, we are holding all the stripes so the array
1043 * is completely stalled, so now is a good time to resize
1046 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1048 for (i=0; i<conf->raid_disks; i++)
1049 ndisks[i] = conf->disks[i];
1051 conf->disks = ndisks;
1055 /* Step 4, return new stripes to service */
1056 while(!list_empty(&newstripes)) {
1057 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1058 list_del_init(&nsh->lru);
1059 for (i=conf->raid_disks; i < newsize; i++)
1060 if (nsh->dev[i].page == NULL) {
1061 struct page *p = alloc_page(GFP_NOIO);
1062 nsh->dev[i].page = p;
1066 release_stripe(nsh);
1068 /* critical section pass, GFP_NOIO no longer needed */
1070 conf->slab_cache = sc;
1071 conf->active_name = 1-conf->active_name;
1072 conf->pool_size = newsize;
1077 static int drop_one_stripe(raid5_conf_t *conf)
1079 struct stripe_head *sh;
1081 spin_lock_irq(&conf->device_lock);
1082 sh = get_free_stripe(conf);
1083 spin_unlock_irq(&conf->device_lock);
1086 BUG_ON(atomic_read(&sh->count));
1087 shrink_buffers(sh, conf->pool_size);
1088 kmem_cache_free(conf->slab_cache, sh);
1089 atomic_dec(&conf->active_stripes);
1093 static void shrink_stripes(raid5_conf_t *conf)
1095 while (drop_one_stripe(conf))
1098 if (conf->slab_cache)
1099 kmem_cache_destroy(conf->slab_cache);
1100 conf->slab_cache = NULL;
1103 static void raid5_end_read_request(struct bio * bi, int error)
1105 struct stripe_head *sh = bi->bi_private;
1106 raid5_conf_t *conf = sh->raid_conf;
1107 int disks = sh->disks, i;
1108 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1109 char b[BDEVNAME_SIZE];
1113 for (i=0 ; i<disks; i++)
1114 if (bi == &sh->dev[i].req)
1117 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1118 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1126 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1127 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1128 rdev = conf->disks[i].rdev;
1129 printk_rl(KERN_INFO "raid5:%s: read error corrected"
1130 " (%lu sectors at %llu on %s)\n",
1131 mdname(conf->mddev), STRIPE_SECTORS,
1132 (unsigned long long)(sh->sector
1133 + rdev->data_offset),
1134 bdevname(rdev->bdev, b));
1135 clear_bit(R5_ReadError, &sh->dev[i].flags);
1136 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1138 if (atomic_read(&conf->disks[i].rdev->read_errors))
1139 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1141 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
1143 rdev = conf->disks[i].rdev;
1145 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1146 atomic_inc(&rdev->read_errors);
1147 if (conf->mddev->degraded)
1148 printk_rl(KERN_WARNING
1149 "raid5:%s: read error not correctable "
1150 "(sector %llu on %s).\n",
1151 mdname(conf->mddev),
1152 (unsigned long long)(sh->sector
1153 + rdev->data_offset),
1155 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
1157 printk_rl(KERN_WARNING
1158 "raid5:%s: read error NOT corrected!! "
1159 "(sector %llu on %s).\n",
1160 mdname(conf->mddev),
1161 (unsigned long long)(sh->sector
1162 + rdev->data_offset),
1164 else if (atomic_read(&rdev->read_errors)
1165 > conf->max_nr_stripes)
1167 "raid5:%s: Too many read errors, failing device %s.\n",
1168 mdname(conf->mddev), bdn);
1172 set_bit(R5_ReadError, &sh->dev[i].flags);
1174 clear_bit(R5_ReadError, &sh->dev[i].flags);
1175 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1176 md_error(conf->mddev, rdev);
1179 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1180 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1181 set_bit(STRIPE_HANDLE, &sh->state);
1185 static void raid5_end_write_request(struct bio *bi, int error)
1187 struct stripe_head *sh = bi->bi_private;
1188 raid5_conf_t *conf = sh->raid_conf;
1189 int disks = sh->disks, i;
1190 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1192 for (i=0 ; i<disks; i++)
1193 if (bi == &sh->dev[i].req)
1196 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1197 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1205 md_error(conf->mddev, conf->disks[i].rdev);
1207 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1209 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1210 set_bit(STRIPE_HANDLE, &sh->state);
1215 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous);
1217 static void raid5_build_block(struct stripe_head *sh, int i, int previous)
1219 struct r5dev *dev = &sh->dev[i];
1221 bio_init(&dev->req);
1222 dev->req.bi_io_vec = &dev->vec;
1224 dev->req.bi_max_vecs++;
1225 dev->vec.bv_page = dev->page;
1226 dev->vec.bv_len = STRIPE_SIZE;
1227 dev->vec.bv_offset = 0;
1229 dev->req.bi_sector = sh->sector;
1230 dev->req.bi_private = sh;
1233 dev->sector = compute_blocknr(sh, i, previous);
1236 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1238 char b[BDEVNAME_SIZE];
1239 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
1240 pr_debug("raid5: error called\n");
1242 if (!test_bit(Faulty, &rdev->flags)) {
1243 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1244 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1245 unsigned long flags;
1246 spin_lock_irqsave(&conf->device_lock, flags);
1248 spin_unlock_irqrestore(&conf->device_lock, flags);
1250 * if recovery was running, make sure it aborts.
1252 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1254 set_bit(Faulty, &rdev->flags);
1256 "raid5: Disk failure on %s, disabling device.\n"
1257 "raid5: Operation continuing on %d devices.\n",
1258 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
1263 * Input: a 'big' sector number,
1264 * Output: index of the data and parity disk, and the sector # in them.
1266 static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
1267 int previous, int *dd_idx,
1268 struct stripe_head *sh)
1271 unsigned long chunk_number;
1272 unsigned int chunk_offset;
1275 sector_t new_sector;
1276 int algorithm = previous ? conf->prev_algo
1278 int sectors_per_chunk = previous ? (conf->prev_chunk >> 9)
1279 : (conf->chunk_size >> 9);
1280 int raid_disks = previous ? conf->previous_raid_disks
1282 int data_disks = raid_disks - conf->max_degraded;
1284 /* First compute the information on this sector */
1287 * Compute the chunk number and the sector offset inside the chunk
1289 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1290 chunk_number = r_sector;
1291 BUG_ON(r_sector != chunk_number);
1294 * Compute the stripe number
1296 stripe = chunk_number / data_disks;
1299 * Compute the data disk and parity disk indexes inside the stripe
1301 *dd_idx = chunk_number % data_disks;
1304 * Select the parity disk based on the user selected algorithm.
1306 pd_idx = qd_idx = ~0;
1307 switch(conf->level) {
1309 pd_idx = data_disks;
1312 switch (algorithm) {
1313 case ALGORITHM_LEFT_ASYMMETRIC:
1314 pd_idx = data_disks - stripe % raid_disks;
1315 if (*dd_idx >= pd_idx)
1318 case ALGORITHM_RIGHT_ASYMMETRIC:
1319 pd_idx = stripe % raid_disks;
1320 if (*dd_idx >= pd_idx)
1323 case ALGORITHM_LEFT_SYMMETRIC:
1324 pd_idx = data_disks - stripe % raid_disks;
1325 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1327 case ALGORITHM_RIGHT_SYMMETRIC:
1328 pd_idx = stripe % raid_disks;
1329 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1331 case ALGORITHM_PARITY_0:
1335 case ALGORITHM_PARITY_N:
1336 pd_idx = data_disks;
1339 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
1346 switch (algorithm) {
1347 case ALGORITHM_LEFT_ASYMMETRIC:
1348 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1349 qd_idx = pd_idx + 1;
1350 if (pd_idx == raid_disks-1) {
1351 (*dd_idx)++; /* Q D D D P */
1353 } else if (*dd_idx >= pd_idx)
1354 (*dd_idx) += 2; /* D D P Q D */
1356 case ALGORITHM_RIGHT_ASYMMETRIC:
1357 pd_idx = stripe % raid_disks;
1358 qd_idx = pd_idx + 1;
1359 if (pd_idx == raid_disks-1) {
1360 (*dd_idx)++; /* Q D D D P */
1362 } else if (*dd_idx >= pd_idx)
1363 (*dd_idx) += 2; /* D D P Q D */
1365 case ALGORITHM_LEFT_SYMMETRIC:
1366 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1367 qd_idx = (pd_idx + 1) % raid_disks;
1368 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1370 case ALGORITHM_RIGHT_SYMMETRIC:
1371 pd_idx = stripe % raid_disks;
1372 qd_idx = (pd_idx + 1) % raid_disks;
1373 *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
1376 case ALGORITHM_PARITY_0:
1381 case ALGORITHM_PARITY_N:
1382 pd_idx = data_disks;
1383 qd_idx = data_disks + 1;
1386 case ALGORITHM_ROTATING_ZERO_RESTART:
1387 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1388 * of blocks for computing Q is different.
1390 pd_idx = stripe % raid_disks;
1391 qd_idx = pd_idx + 1;
1392 if (pd_idx == raid_disks-1) {
1393 (*dd_idx)++; /* Q D D D P */
1395 } else if (*dd_idx >= pd_idx)
1396 (*dd_idx) += 2; /* D D P Q D */
1400 case ALGORITHM_ROTATING_N_RESTART:
1401 /* Same a left_asymmetric, by first stripe is
1402 * D D D P Q rather than
1405 pd_idx = raid_disks - 1 - ((stripe + 1) % raid_disks);
1406 qd_idx = pd_idx + 1;
1407 if (pd_idx == raid_disks-1) {
1408 (*dd_idx)++; /* Q D D D P */
1410 } else if (*dd_idx >= pd_idx)
1411 (*dd_idx) += 2; /* D D P Q D */
1415 case ALGORITHM_ROTATING_N_CONTINUE:
1416 /* Same as left_symmetric but Q is before P */
1417 pd_idx = raid_disks - 1 - (stripe % raid_disks);
1418 qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
1419 *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
1423 case ALGORITHM_LEFT_ASYMMETRIC_6:
1424 /* RAID5 left_asymmetric, with Q on last device */
1425 pd_idx = data_disks - stripe % (raid_disks-1);
1426 if (*dd_idx >= pd_idx)
1428 qd_idx = raid_disks - 1;
1431 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1432 pd_idx = stripe % (raid_disks-1);
1433 if (*dd_idx >= pd_idx)
1435 qd_idx = raid_disks - 1;
1438 case ALGORITHM_LEFT_SYMMETRIC_6:
1439 pd_idx = data_disks - stripe % (raid_disks-1);
1440 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1441 qd_idx = raid_disks - 1;
1444 case ALGORITHM_RIGHT_SYMMETRIC_6:
1445 pd_idx = stripe % (raid_disks-1);
1446 *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
1447 qd_idx = raid_disks - 1;
1450 case ALGORITHM_PARITY_0_6:
1453 qd_idx = raid_disks - 1;
1458 printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
1466 sh->pd_idx = pd_idx;
1467 sh->qd_idx = qd_idx;
1468 sh->ddf_layout = ddf_layout;
1471 * Finally, compute the new sector number
1473 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1478 static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
1480 raid5_conf_t *conf = sh->raid_conf;
1481 int raid_disks = sh->disks;
1482 int data_disks = raid_disks - conf->max_degraded;
1483 sector_t new_sector = sh->sector, check;
1484 int sectors_per_chunk = previous ? (conf->prev_chunk >> 9)
1485 : (conf->chunk_size >> 9);
1486 int algorithm = previous ? conf->prev_algo
1490 int chunk_number, dummy1, dd_idx = i;
1492 struct stripe_head sh2;
1495 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1496 stripe = new_sector;
1497 BUG_ON(new_sector != stripe);
1499 if (i == sh->pd_idx)
1501 switch(conf->level) {
1504 switch (algorithm) {
1505 case ALGORITHM_LEFT_ASYMMETRIC:
1506 case ALGORITHM_RIGHT_ASYMMETRIC:
1510 case ALGORITHM_LEFT_SYMMETRIC:
1511 case ALGORITHM_RIGHT_SYMMETRIC:
1514 i -= (sh->pd_idx + 1);
1516 case ALGORITHM_PARITY_0:
1519 case ALGORITHM_PARITY_N:
1522 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
1528 if (i == sh->qd_idx)
1529 return 0; /* It is the Q disk */
1530 switch (algorithm) {
1531 case ALGORITHM_LEFT_ASYMMETRIC:
1532 case ALGORITHM_RIGHT_ASYMMETRIC:
1533 case ALGORITHM_ROTATING_ZERO_RESTART:
1534 case ALGORITHM_ROTATING_N_RESTART:
1535 if (sh->pd_idx == raid_disks-1)
1536 i--; /* Q D D D P */
1537 else if (i > sh->pd_idx)
1538 i -= 2; /* D D P Q D */
1540 case ALGORITHM_LEFT_SYMMETRIC:
1541 case ALGORITHM_RIGHT_SYMMETRIC:
1542 if (sh->pd_idx == raid_disks-1)
1543 i--; /* Q D D D P */
1548 i -= (sh->pd_idx + 2);
1551 case ALGORITHM_PARITY_0:
1554 case ALGORITHM_PARITY_N:
1556 case ALGORITHM_ROTATING_N_CONTINUE:
1557 if (sh->pd_idx == 0)
1558 i--; /* P D D D Q */
1559 else if (i > sh->pd_idx)
1560 i -= 2; /* D D Q P D */
1562 case ALGORITHM_LEFT_ASYMMETRIC_6:
1563 case ALGORITHM_RIGHT_ASYMMETRIC_6:
1567 case ALGORITHM_LEFT_SYMMETRIC_6:
1568 case ALGORITHM_RIGHT_SYMMETRIC_6:
1570 i += data_disks + 1;
1571 i -= (sh->pd_idx + 1);
1573 case ALGORITHM_PARITY_0_6:
1577 printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
1584 chunk_number = stripe * data_disks + i;
1585 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
1587 check = raid5_compute_sector(conf, r_sector,
1588 previous, &dummy1, &sh2);
1589 if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
1590 || sh2.qd_idx != sh->qd_idx) {
1591 printk(KERN_ERR "compute_blocknr: map not correct\n");
1600 * Copy data between a page in the stripe cache, and one or more bion
1601 * The page could align with the middle of the bio, or there could be
1602 * several bion, each with several bio_vecs, which cover part of the page
1603 * Multiple bion are linked together on bi_next. There may be extras
1604 * at the end of this list. We ignore them.
1606 static void copy_data(int frombio, struct bio *bio,
1610 char *pa = page_address(page);
1611 struct bio_vec *bvl;
1615 if (bio->bi_sector >= sector)
1616 page_offset = (signed)(bio->bi_sector - sector) * 512;
1618 page_offset = (signed)(sector - bio->bi_sector) * -512;
1619 bio_for_each_segment(bvl, bio, i) {
1620 int len = bio_iovec_idx(bio,i)->bv_len;
1624 if (page_offset < 0) {
1625 b_offset = -page_offset;
1626 page_offset += b_offset;
1630 if (len > 0 && page_offset + len > STRIPE_SIZE)
1631 clen = STRIPE_SIZE - page_offset;
1635 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
1637 memcpy(pa+page_offset, ba+b_offset, clen);
1639 memcpy(ba+b_offset, pa+page_offset, clen);
1640 __bio_kunmap_atomic(ba, KM_USER0);
1642 if (clen < len) /* hit end of page */
1648 #define check_xor() do { \
1649 if (count == MAX_XOR_BLOCKS) { \
1650 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1655 static void compute_parity6(struct stripe_head *sh, int method)
1657 raid5_conf_t *conf = sh->raid_conf;
1658 int i, pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
1659 int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
1661 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1662 void *ptrs[syndrome_disks+2];
1664 pd_idx = sh->pd_idx;
1665 qd_idx = sh->qd_idx;
1666 d0_idx = raid6_d0(sh);
1668 pr_debug("compute_parity, stripe %llu, method %d\n",
1669 (unsigned long long)sh->sector, method);
1672 case READ_MODIFY_WRITE:
1673 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1674 case RECONSTRUCT_WRITE:
1675 for (i= disks; i-- ;)
1676 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1677 chosen = sh->dev[i].towrite;
1678 sh->dev[i].towrite = NULL;
1680 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1681 wake_up(&conf->wait_for_overlap);
1683 BUG_ON(sh->dev[i].written);
1684 sh->dev[i].written = chosen;
1688 BUG(); /* Not implemented yet */
1691 for (i = disks; i--;)
1692 if (sh->dev[i].written) {
1693 sector_t sector = sh->dev[i].sector;
1694 struct bio *wbi = sh->dev[i].written;
1695 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1696 copy_data(1, wbi, sh->dev[i].page, sector);
1697 wbi = r5_next_bio(wbi, sector);
1700 set_bit(R5_LOCKED, &sh->dev[i].flags);
1701 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1704 /* Note that unlike RAID-5, the ordering of the disks matters greatly.*/
1706 for (i = 0; i < disks; i++)
1707 ptrs[i] = (void *)raid6_empty_zero_page;
1712 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1714 ptrs[slot] = page_address(sh->dev[i].page);
1715 if (slot < syndrome_disks &&
1716 !test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
1717 printk(KERN_ERR "block %d/%d not uptodate "
1718 "on parity calc\n", i, count);
1722 i = raid6_next_disk(i, disks);
1723 } while (i != d0_idx);
1724 BUG_ON(count != syndrome_disks);
1726 raid6_call.gen_syndrome(syndrome_disks+2, STRIPE_SIZE, ptrs);
1729 case RECONSTRUCT_WRITE:
1730 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1731 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1732 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1733 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1736 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1737 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1743 /* Compute one missing block */
1744 static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1746 int i, count, disks = sh->disks;
1747 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
1748 int qd_idx = sh->qd_idx;
1750 pr_debug("compute_block_1, stripe %llu, idx %d\n",
1751 (unsigned long long)sh->sector, dd_idx);
1753 if ( dd_idx == qd_idx ) {
1754 /* We're actually computing the Q drive */
1755 compute_parity6(sh, UPDATE_PARITY);
1757 dest = page_address(sh->dev[dd_idx].page);
1758 if (!nozero) memset(dest, 0, STRIPE_SIZE);
1760 for (i = disks ; i--; ) {
1761 if (i == dd_idx || i == qd_idx)
1763 p = page_address(sh->dev[i].page);
1764 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1767 printk("compute_block() %d, stripe %llu, %d"
1768 " not present\n", dd_idx,
1769 (unsigned long long)sh->sector, i);
1774 xor_blocks(count, STRIPE_SIZE, dest, ptr);
1775 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1776 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1780 /* Compute two missing blocks */
1781 static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1783 int i, count, disks = sh->disks;
1784 int syndrome_disks = sh->ddf_layout ? disks : disks-2;
1785 int d0_idx = raid6_d0(sh);
1786 int faila = -1, failb = -1;
1787 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1788 void *ptrs[syndrome_disks+2];
1790 for (i = 0; i < disks ; i++)
1791 ptrs[i] = (void *)raid6_empty_zero_page;
1795 int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
1797 ptrs[slot] = page_address(sh->dev[i].page);
1803 i = raid6_next_disk(i, disks);
1804 } while (i != d0_idx);
1805 BUG_ON(count != syndrome_disks);
1807 BUG_ON(faila == failb);
1808 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1810 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1811 (unsigned long long)sh->sector, dd_idx1, dd_idx2,
1814 if (failb == syndrome_disks+1) {
1815 /* Q disk is one of the missing disks */
1816 if (faila == syndrome_disks) {
1817 /* Missing P+Q, just recompute */
1818 compute_parity6(sh, UPDATE_PARITY);
1821 /* We're missing D+Q; recompute D from P */
1822 compute_block_1(sh, ((dd_idx1 == sh->qd_idx) ?
1825 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1830 /* We're missing D+P or D+D; */
1831 if (failb == syndrome_disks) {
1832 /* We're missing D+P. */
1833 raid6_datap_recov(syndrome_disks+2, STRIPE_SIZE, faila, ptrs);
1835 /* We're missing D+D. */
1836 raid6_2data_recov(syndrome_disks+2, STRIPE_SIZE, faila, failb,
1840 /* Both the above update both missing blocks */
1841 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1842 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1846 schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
1847 int rcw, int expand)
1849 int i, pd_idx = sh->pd_idx, disks = sh->disks;
1852 /* if we are not expanding this is a proper write request, and
1853 * there will be bios with new data to be drained into the
1857 sh->reconstruct_state = reconstruct_state_drain_run;
1858 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
1860 sh->reconstruct_state = reconstruct_state_run;
1862 set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
1864 for (i = disks; i--; ) {
1865 struct r5dev *dev = &sh->dev[i];
1868 set_bit(R5_LOCKED, &dev->flags);
1869 set_bit(R5_Wantdrain, &dev->flags);
1871 clear_bit(R5_UPTODATE, &dev->flags);
1875 if (s->locked + 1 == disks)
1876 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
1877 atomic_inc(&sh->raid_conf->pending_full_writes);
1879 BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
1880 test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
1882 sh->reconstruct_state = reconstruct_state_prexor_drain_run;
1883 set_bit(STRIPE_OP_PREXOR, &s->ops_request);
1884 set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
1885 set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
1887 for (i = disks; i--; ) {
1888 struct r5dev *dev = &sh->dev[i];
1893 (test_bit(R5_UPTODATE, &dev->flags) ||
1894 test_bit(R5_Wantcompute, &dev->flags))) {
1895 set_bit(R5_Wantdrain, &dev->flags);
1896 set_bit(R5_LOCKED, &dev->flags);
1897 clear_bit(R5_UPTODATE, &dev->flags);
1903 /* keep the parity disk locked while asynchronous operations
1906 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1907 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1910 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
1911 __func__, (unsigned long long)sh->sector,
1912 s->locked, s->ops_request);
1916 * Each stripe/dev can have one or more bion attached.
1917 * toread/towrite point to the first in a chain.
1918 * The bi_next chain must be in order.
1920 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1923 raid5_conf_t *conf = sh->raid_conf;
1926 pr_debug("adding bh b#%llu to stripe s#%llu\n",
1927 (unsigned long long)bi->bi_sector,
1928 (unsigned long long)sh->sector);
1931 spin_lock(&sh->lock);
1932 spin_lock_irq(&conf->device_lock);
1934 bip = &sh->dev[dd_idx].towrite;
1935 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1938 bip = &sh->dev[dd_idx].toread;
1939 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1940 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1942 bip = & (*bip)->bi_next;
1944 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1947 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
1951 bi->bi_phys_segments++;
1952 spin_unlock_irq(&conf->device_lock);
1953 spin_unlock(&sh->lock);
1955 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
1956 (unsigned long long)bi->bi_sector,
1957 (unsigned long long)sh->sector, dd_idx);
1959 if (conf->mddev->bitmap && firstwrite) {
1960 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1962 sh->bm_seq = conf->seq_flush+1;
1963 set_bit(STRIPE_BIT_DELAY, &sh->state);
1967 /* check if page is covered */
1968 sector_t sector = sh->dev[dd_idx].sector;
1969 for (bi=sh->dev[dd_idx].towrite;
1970 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1971 bi && bi->bi_sector <= sector;
1972 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1973 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1974 sector = bi->bi_sector + (bi->bi_size>>9);
1976 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1977 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1982 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1983 spin_unlock_irq(&conf->device_lock);
1984 spin_unlock(&sh->lock);
1988 static void end_reshape(raid5_conf_t *conf);
1990 static int page_is_zero(struct page *p)
1992 char *a = page_address(p);
1993 return ((*(u32*)a) == 0 &&
1994 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1997 static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
1998 struct stripe_head *sh)
2000 int sectors_per_chunk =
2001 previous ? (conf->prev_chunk >> 9)
2002 : (conf->chunk_size >> 9);
2004 int chunk_offset = sector_div(stripe, sectors_per_chunk);
2005 int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
2007 raid5_compute_sector(conf,
2008 stripe * (disks - conf->max_degraded)
2009 *sectors_per_chunk + chunk_offset,
2015 handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
2016 struct stripe_head_state *s, int disks,
2017 struct bio **return_bi)
2020 for (i = disks; i--; ) {
2024 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
2027 rdev = rcu_dereference(conf->disks[i].rdev);
2028 if (rdev && test_bit(In_sync, &rdev->flags))
2029 /* multiple read failures in one stripe */
2030 md_error(conf->mddev, rdev);
2033 spin_lock_irq(&conf->device_lock);
2034 /* fail all writes first */
2035 bi = sh->dev[i].towrite;
2036 sh->dev[i].towrite = NULL;
2042 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2043 wake_up(&conf->wait_for_overlap);
2045 while (bi && bi->bi_sector <
2046 sh->dev[i].sector + STRIPE_SECTORS) {
2047 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2048 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2049 if (!raid5_dec_bi_phys_segments(bi)) {
2050 md_write_end(conf->mddev);
2051 bi->bi_next = *return_bi;
2056 /* and fail all 'written' */
2057 bi = sh->dev[i].written;
2058 sh->dev[i].written = NULL;
2059 if (bi) bitmap_end = 1;
2060 while (bi && bi->bi_sector <
2061 sh->dev[i].sector + STRIPE_SECTORS) {
2062 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2063 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2064 if (!raid5_dec_bi_phys_segments(bi)) {
2065 md_write_end(conf->mddev);
2066 bi->bi_next = *return_bi;
2072 /* fail any reads if this device is non-operational and
2073 * the data has not reached the cache yet.
2075 if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
2076 (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2077 test_bit(R5_ReadError, &sh->dev[i].flags))) {
2078 bi = sh->dev[i].toread;
2079 sh->dev[i].toread = NULL;
2080 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2081 wake_up(&conf->wait_for_overlap);
2082 if (bi) s->to_read--;
2083 while (bi && bi->bi_sector <
2084 sh->dev[i].sector + STRIPE_SECTORS) {
2085 struct bio *nextbi =
2086 r5_next_bio(bi, sh->dev[i].sector);
2087 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2088 if (!raid5_dec_bi_phys_segments(bi)) {
2089 bi->bi_next = *return_bi;
2095 spin_unlock_irq(&conf->device_lock);
2097 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2098 STRIPE_SECTORS, 0, 0);
2101 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2102 if (atomic_dec_and_test(&conf->pending_full_writes))
2103 md_wakeup_thread(conf->mddev->thread);
2106 /* fetch_block5 - checks the given member device to see if its data needs
2107 * to be read or computed to satisfy a request.
2109 * Returns 1 when no more member devices need to be checked, otherwise returns
2110 * 0 to tell the loop in handle_stripe_fill5 to continue
2112 static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
2113 int disk_idx, int disks)
2115 struct r5dev *dev = &sh->dev[disk_idx];
2116 struct r5dev *failed_dev = &sh->dev[s->failed_num];
2118 /* is the data in this block needed, and can we get it? */
2119 if (!test_bit(R5_LOCKED, &dev->flags) &&
2120 !test_bit(R5_UPTODATE, &dev->flags) &&
2122 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2123 s->syncing || s->expanding ||
2125 (failed_dev->toread ||
2126 (failed_dev->towrite &&
2127 !test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
2128 /* We would like to get this block, possibly by computing it,
2129 * otherwise read it if the backing disk is insync
2131 if ((s->uptodate == disks - 1) &&
2132 (s->failed && disk_idx == s->failed_num)) {
2133 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2134 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2135 set_bit(R5_Wantcompute, &dev->flags);
2136 sh->ops.target = disk_idx;
2138 /* Careful: from this point on 'uptodate' is in the eye
2139 * of raid5_run_ops which services 'compute' operations
2140 * before writes. R5_Wantcompute flags a block that will
2141 * be R5_UPTODATE by the time it is needed for a
2142 * subsequent operation.
2145 return 1; /* uptodate + compute == disks */
2146 } else if (test_bit(R5_Insync, &dev->flags)) {
2147 set_bit(R5_LOCKED, &dev->flags);
2148 set_bit(R5_Wantread, &dev->flags);
2150 pr_debug("Reading block %d (sync=%d)\n", disk_idx,
2159 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
2161 static void handle_stripe_fill5(struct stripe_head *sh,
2162 struct stripe_head_state *s, int disks)
2166 /* look for blocks to read/compute, skip this if a compute
2167 * is already in flight, or if the stripe contents are in the
2168 * midst of changing due to a write
2170 if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
2171 !sh->reconstruct_state)
2172 for (i = disks; i--; )
2173 if (fetch_block5(sh, s, i, disks))
2175 set_bit(STRIPE_HANDLE, &sh->state);
2178 static void handle_stripe_fill6(struct stripe_head *sh,
2179 struct stripe_head_state *s, struct r6_state *r6s,
2183 for (i = disks; i--; ) {
2184 struct r5dev *dev = &sh->dev[i];
2185 if (!test_bit(R5_LOCKED, &dev->flags) &&
2186 !test_bit(R5_UPTODATE, &dev->flags) &&
2187 (dev->toread || (dev->towrite &&
2188 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2189 s->syncing || s->expanding ||
2191 (sh->dev[r6s->failed_num[0]].toread ||
2194 (sh->dev[r6s->failed_num[1]].toread ||
2196 /* we would like to get this block, possibly
2197 * by computing it, but we might not be able to
2199 if ((s->uptodate == disks - 1) &&
2200 (s->failed && (i == r6s->failed_num[0] ||
2201 i == r6s->failed_num[1]))) {
2202 pr_debug("Computing stripe %llu block %d\n",
2203 (unsigned long long)sh->sector, i);
2204 compute_block_1(sh, i, 0);
2206 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2207 /* Computing 2-failure is *very* expensive; only
2208 * do it if failed >= 2
2211 for (other = disks; other--; ) {
2214 if (!test_bit(R5_UPTODATE,
2215 &sh->dev[other].flags))
2219 pr_debug("Computing stripe %llu blocks %d,%d\n",
2220 (unsigned long long)sh->sector,
2222 compute_block_2(sh, i, other);
2224 } else if (test_bit(R5_Insync, &dev->flags)) {
2225 set_bit(R5_LOCKED, &dev->flags);
2226 set_bit(R5_Wantread, &dev->flags);
2228 pr_debug("Reading block %d (sync=%d)\n",
2233 set_bit(STRIPE_HANDLE, &sh->state);
2237 /* handle_stripe_clean_event
2238 * any written block on an uptodate or failed drive can be returned.
2239 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2240 * never LOCKED, so we don't need to test 'failed' directly.
2242 static void handle_stripe_clean_event(raid5_conf_t *conf,
2243 struct stripe_head *sh, int disks, struct bio **return_bi)
2248 for (i = disks; i--; )
2249 if (sh->dev[i].written) {
2251 if (!test_bit(R5_LOCKED, &dev->flags) &&
2252 test_bit(R5_UPTODATE, &dev->flags)) {
2253 /* We can return any write requests */
2254 struct bio *wbi, *wbi2;
2256 pr_debug("Return write for disc %d\n", i);
2257 spin_lock_irq(&conf->device_lock);
2259 dev->written = NULL;
2260 while (wbi && wbi->bi_sector <
2261 dev->sector + STRIPE_SECTORS) {
2262 wbi2 = r5_next_bio(wbi, dev->sector);
2263 if (!raid5_dec_bi_phys_segments(wbi)) {
2264 md_write_end(conf->mddev);
2265 wbi->bi_next = *return_bi;
2270 if (dev->towrite == NULL)
2272 spin_unlock_irq(&conf->device_lock);
2274 bitmap_endwrite(conf->mddev->bitmap,
2277 !test_bit(STRIPE_DEGRADED, &sh->state),
2282 if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
2283 if (atomic_dec_and_test(&conf->pending_full_writes))
2284 md_wakeup_thread(conf->mddev->thread);
2287 static void handle_stripe_dirtying5(raid5_conf_t *conf,
2288 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2290 int rmw = 0, rcw = 0, i;
2291 for (i = disks; i--; ) {
2292 /* would I have to read this buffer for read_modify_write */
2293 struct r5dev *dev = &sh->dev[i];
2294 if ((dev->towrite || i == sh->pd_idx) &&
2295 !test_bit(R5_LOCKED, &dev->flags) &&
2296 !(test_bit(R5_UPTODATE, &dev->flags) ||
2297 test_bit(R5_Wantcompute, &dev->flags))) {
2298 if (test_bit(R5_Insync, &dev->flags))
2301 rmw += 2*disks; /* cannot read it */
2303 /* Would I have to read this buffer for reconstruct_write */
2304 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2305 !test_bit(R5_LOCKED, &dev->flags) &&
2306 !(test_bit(R5_UPTODATE, &dev->flags) ||
2307 test_bit(R5_Wantcompute, &dev->flags))) {
2308 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2313 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2314 (unsigned long long)sh->sector, rmw, rcw);
2315 set_bit(STRIPE_HANDLE, &sh->state);
2316 if (rmw < rcw && rmw > 0)
2317 /* prefer read-modify-write, but need to get some data */
2318 for (i = disks; i--; ) {
2319 struct r5dev *dev = &sh->dev[i];
2320 if ((dev->towrite || i == sh->pd_idx) &&
2321 !test_bit(R5_LOCKED, &dev->flags) &&
2322 !(test_bit(R5_UPTODATE, &dev->flags) ||
2323 test_bit(R5_Wantcompute, &dev->flags)) &&
2324 test_bit(R5_Insync, &dev->flags)) {
2326 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2327 pr_debug("Read_old block "
2328 "%d for r-m-w\n", i);
2329 set_bit(R5_LOCKED, &dev->flags);
2330 set_bit(R5_Wantread, &dev->flags);
2333 set_bit(STRIPE_DELAYED, &sh->state);
2334 set_bit(STRIPE_HANDLE, &sh->state);
2338 if (rcw <= rmw && rcw > 0)
2339 /* want reconstruct write, but need to get some data */
2340 for (i = disks; i--; ) {
2341 struct r5dev *dev = &sh->dev[i];
2342 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2344 !test_bit(R5_LOCKED, &dev->flags) &&
2345 !(test_bit(R5_UPTODATE, &dev->flags) ||
2346 test_bit(R5_Wantcompute, &dev->flags)) &&
2347 test_bit(R5_Insync, &dev->flags)) {
2349 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2350 pr_debug("Read_old block "
2351 "%d for Reconstruct\n", i);
2352 set_bit(R5_LOCKED, &dev->flags);
2353 set_bit(R5_Wantread, &dev->flags);
2356 set_bit(STRIPE_DELAYED, &sh->state);
2357 set_bit(STRIPE_HANDLE, &sh->state);
2361 /* now if nothing is locked, and if we have enough data,
2362 * we can start a write request
2364 /* since handle_stripe can be called at any time we need to handle the
2365 * case where a compute block operation has been submitted and then a
2366 * subsequent call wants to start a write request. raid5_run_ops only
2367 * handles the case where compute block and postxor are requested
2368 * simultaneously. If this is not the case then new writes need to be
2369 * held off until the compute completes.
2371 if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
2372 (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2373 !test_bit(STRIPE_BIT_DELAY, &sh->state)))
2374 schedule_reconstruction5(sh, s, rcw == 0, 0);
2377 static void handle_stripe_dirtying6(raid5_conf_t *conf,
2378 struct stripe_head *sh, struct stripe_head_state *s,
2379 struct r6_state *r6s, int disks)
2381 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
2382 int qd_idx = sh->qd_idx;
2383 for (i = disks; i--; ) {
2384 struct r5dev *dev = &sh->dev[i];
2385 /* Would I have to read this buffer for reconstruct_write */
2386 if (!test_bit(R5_OVERWRITE, &dev->flags)
2387 && i != pd_idx && i != qd_idx
2388 && (!test_bit(R5_LOCKED, &dev->flags)
2390 !test_bit(R5_UPTODATE, &dev->flags)) {
2391 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2393 pr_debug("raid6: must_compute: "
2394 "disk %d flags=%#lx\n", i, dev->flags);
2399 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
2400 (unsigned long long)sh->sector, rcw, must_compute);
2401 set_bit(STRIPE_HANDLE, &sh->state);
2404 /* want reconstruct write, but need to get some data */
2405 for (i = disks; i--; ) {
2406 struct r5dev *dev = &sh->dev[i];
2407 if (!test_bit(R5_OVERWRITE, &dev->flags)
2408 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2409 && !test_bit(R5_LOCKED, &dev->flags) &&
2410 !test_bit(R5_UPTODATE, &dev->flags) &&
2411 test_bit(R5_Insync, &dev->flags)) {
2413 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2414 pr_debug("Read_old stripe %llu "
2415 "block %d for Reconstruct\n",
2416 (unsigned long long)sh->sector, i);
2417 set_bit(R5_LOCKED, &dev->flags);
2418 set_bit(R5_Wantread, &dev->flags);
2421 pr_debug("Request delayed stripe %llu "
2422 "block %d for Reconstruct\n",
2423 (unsigned long long)sh->sector, i);
2424 set_bit(STRIPE_DELAYED, &sh->state);
2425 set_bit(STRIPE_HANDLE, &sh->state);
2429 /* now if nothing is locked, and if we have enough data, we can start a
2432 if (s->locked == 0 && rcw == 0 &&
2433 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2434 if (must_compute > 0) {
2435 /* We have failed blocks and need to compute them */
2436 switch (s->failed) {
2440 compute_block_1(sh, r6s->failed_num[0], 0);
2443 compute_block_2(sh, r6s->failed_num[0],
2444 r6s->failed_num[1]);
2446 default: /* This request should have been failed? */
2451 pr_debug("Computing parity for stripe %llu\n",
2452 (unsigned long long)sh->sector);
2453 compute_parity6(sh, RECONSTRUCT_WRITE);
2454 /* now every locked buffer is ready to be written */
2455 for (i = disks; i--; )
2456 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
2457 pr_debug("Writing stripe %llu block %d\n",
2458 (unsigned long long)sh->sector, i);
2460 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2462 if (s->locked == disks)
2463 if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
2464 atomic_inc(&conf->pending_full_writes);
2465 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2466 set_bit(STRIPE_INSYNC, &sh->state);
2468 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2469 atomic_dec(&conf->preread_active_stripes);
2470 if (atomic_read(&conf->preread_active_stripes) <
2472 md_wakeup_thread(conf->mddev->thread);
2477 static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2478 struct stripe_head_state *s, int disks)
2480 struct r5dev *dev = NULL;
2482 set_bit(STRIPE_HANDLE, &sh->state);
2484 switch (sh->check_state) {
2485 case check_state_idle:
2486 /* start a new check operation if there are no failures */
2487 if (s->failed == 0) {
2488 BUG_ON(s->uptodate != disks);
2489 sh->check_state = check_state_run;
2490 set_bit(STRIPE_OP_CHECK, &s->ops_request);
2491 clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
2495 dev = &sh->dev[s->failed_num];
2497 case check_state_compute_result:
2498 sh->check_state = check_state_idle;
2500 dev = &sh->dev[sh->pd_idx];
2502 /* check that a write has not made the stripe insync */
2503 if (test_bit(STRIPE_INSYNC, &sh->state))
2506 /* either failed parity check, or recovery is happening */
2507 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2508 BUG_ON(s->uptodate != disks);
2510 set_bit(R5_LOCKED, &dev->flags);
2512 set_bit(R5_Wantwrite, &dev->flags);
2514 clear_bit(STRIPE_DEGRADED, &sh->state);
2515 set_bit(STRIPE_INSYNC, &sh->state);
2517 case check_state_run:
2518 break; /* we will be called again upon completion */
2519 case check_state_check_result:
2520 sh->check_state = check_state_idle;
2522 /* if a failure occurred during the check operation, leave
2523 * STRIPE_INSYNC not set and let the stripe be handled again
2528 /* handle a successful check operation, if parity is correct
2529 * we are done. Otherwise update the mismatch count and repair
2530 * parity if !MD_RECOVERY_CHECK
2532 if (sh->ops.zero_sum_result == 0)
2533 /* parity is correct (on disc,
2534 * not in buffer any more)
2536 set_bit(STRIPE_INSYNC, &sh->state);
2538 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2539 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2540 /* don't try to repair!! */
2541 set_bit(STRIPE_INSYNC, &sh->state);
2543 sh->check_state = check_state_compute_run;
2544 set_bit(STRIPE_COMPUTE_RUN, &sh->state);
2545 set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
2546 set_bit(R5_Wantcompute,
2547 &sh->dev[sh->pd_idx].flags);
2548 sh->ops.target = sh->pd_idx;
2553 case check_state_compute_run:
2556 printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
2557 __func__, sh->check_state,
2558 (unsigned long long) sh->sector);
2564 static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2565 struct stripe_head_state *s,
2566 struct r6_state *r6s, struct page *tmp_page,
2569 int update_p = 0, update_q = 0;
2571 int pd_idx = sh->pd_idx;
2572 int qd_idx = sh->qd_idx;
2574 set_bit(STRIPE_HANDLE, &sh->state);
2576 BUG_ON(s->failed > 2);
2577 BUG_ON(s->uptodate < disks);
2578 /* Want to check and possibly repair P and Q.
2579 * However there could be one 'failed' device, in which
2580 * case we can only check one of them, possibly using the
2581 * other to generate missing data
2584 /* If !tmp_page, we cannot do the calculations,
2585 * but as we have set STRIPE_HANDLE, we will soon be called
2586 * by stripe_handle with a tmp_page - just wait until then.
2589 if (s->failed == r6s->q_failed) {
2590 /* The only possible failed device holds 'Q', so it
2591 * makes sense to check P (If anything else were failed,
2592 * we would have used P to recreate it).
2594 compute_block_1(sh, pd_idx, 1);
2595 if (!page_is_zero(sh->dev[pd_idx].page)) {
2596 compute_block_1(sh, pd_idx, 0);
2600 if (!r6s->q_failed && s->failed < 2) {
2601 /* q is not failed, and we didn't use it to generate
2602 * anything, so it makes sense to check it
2604 memcpy(page_address(tmp_page),
2605 page_address(sh->dev[qd_idx].page),
2607 compute_parity6(sh, UPDATE_PARITY);
2608 if (memcmp(page_address(tmp_page),
2609 page_address(sh->dev[qd_idx].page),
2610 STRIPE_SIZE) != 0) {
2611 clear_bit(STRIPE_INSYNC, &sh->state);
2615 if (update_p || update_q) {
2616 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2617 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2618 /* don't try to repair!! */
2619 update_p = update_q = 0;
2622 /* now write out any block on a failed drive,
2623 * or P or Q if they need it
2626 if (s->failed == 2) {
2627 dev = &sh->dev[r6s->failed_num[1]];
2629 set_bit(R5_LOCKED, &dev->flags);
2630 set_bit(R5_Wantwrite, &dev->flags);
2632 if (s->failed >= 1) {
2633 dev = &sh->dev[r6s->failed_num[0]];
2635 set_bit(R5_LOCKED, &dev->flags);
2636 set_bit(R5_Wantwrite, &dev->flags);
2640 dev = &sh->dev[pd_idx];
2642 set_bit(R5_LOCKED, &dev->flags);
2643 set_bit(R5_Wantwrite, &dev->flags);
2646 dev = &sh->dev[qd_idx];
2648 set_bit(R5_LOCKED, &dev->flags);
2649 set_bit(R5_Wantwrite, &dev->flags);
2651 clear_bit(STRIPE_DEGRADED, &sh->state);
2653 set_bit(STRIPE_INSYNC, &sh->state);
2657 static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2658 struct r6_state *r6s)
2662 /* We have read all the blocks in this stripe and now we need to
2663 * copy some of them into a target stripe for expand.
2665 struct dma_async_tx_descriptor *tx = NULL;
2666 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2667 for (i = 0; i < sh->disks; i++)
2668 if (i != sh->pd_idx && i != sh->qd_idx) {
2670 struct stripe_head *sh2;
2672 sector_t bn = compute_blocknr(sh, i, 1);
2673 sector_t s = raid5_compute_sector(conf, bn, 0,
2675 sh2 = get_active_stripe(conf, s, 0, 1);
2677 /* so far only the early blocks of this stripe
2678 * have been requested. When later blocks
2679 * get requested, we will try again
2682 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2683 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2684 /* must have already done this block */
2685 release_stripe(sh2);
2689 /* place all the copies on one channel */
2690 tx = async_memcpy(sh2->dev[dd_idx].page,
2691 sh->dev[i].page, 0, 0, STRIPE_SIZE,
2692 ASYNC_TX_DEP_ACK, tx, NULL, NULL);
2694 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2695 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2696 for (j = 0; j < conf->raid_disks; j++)
2697 if (j != sh2->pd_idx &&
2698 (!r6s || j != sh2->qd_idx) &&
2699 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2701 if (j == conf->raid_disks) {
2702 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2703 set_bit(STRIPE_HANDLE, &sh2->state);
2705 release_stripe(sh2);
2708 /* done submitting copies, wait for them to complete */
2711 dma_wait_for_async_tx(tx);
2717 * handle_stripe - do things to a stripe.
2719 * We lock the stripe and then examine the state of various bits
2720 * to see what needs to be done.
2722 * return some read request which now have data
2723 * return some write requests which are safely on disc
2724 * schedule a read on some buffers
2725 * schedule a write of some buffers
2726 * return confirmation of parity correctness
2728 * buffers are taken off read_list or write_list, and bh_cache buffers
2729 * get BH_Lock set before the stripe lock is released.
2733 static bool handle_stripe5(struct stripe_head *sh)
2735 raid5_conf_t *conf = sh->raid_conf;
2736 int disks = sh->disks, i;
2737 struct bio *return_bi = NULL;
2738 struct stripe_head_state s;
2740 mdk_rdev_t *blocked_rdev = NULL;
2743 memset(&s, 0, sizeof(s));
2744 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2745 "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state,
2746 atomic_read(&sh->count), sh->pd_idx, sh->check_state,
2747 sh->reconstruct_state);
2749 spin_lock(&sh->lock);
2750 clear_bit(STRIPE_HANDLE, &sh->state);
2751 clear_bit(STRIPE_DELAYED, &sh->state);
2753 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2754 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2755 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
2757 /* Now to look around and see what can be done */
2759 for (i=disks; i--; ) {
2761 struct r5dev *dev = &sh->dev[i];
2762 clear_bit(R5_Insync, &dev->flags);
2764 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2765 "written %p\n", i, dev->flags, dev->toread, dev->read,
2766 dev->towrite, dev->written);
2768 /* maybe we can request a biofill operation
2770 * new wantfill requests are only permitted while
2771 * ops_complete_biofill is guaranteed to be inactive
2773 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
2774 !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
2775 set_bit(R5_Wantfill, &dev->flags);
2777 /* now count some things */
2778 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2779 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
2780 if (test_bit(R5_Wantcompute, &dev->flags)) s.compute++;
2782 if (test_bit(R5_Wantfill, &dev->flags))
2784 else if (dev->toread)
2788 if (!test_bit(R5_OVERWRITE, &dev->flags))
2793 rdev = rcu_dereference(conf->disks[i].rdev);
2794 if (blocked_rdev == NULL &&
2795 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
2796 blocked_rdev = rdev;
2797 atomic_inc(&rdev->nr_pending);
2799 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
2800 /* The ReadError flag will just be confusing now */
2801 clear_bit(R5_ReadError, &dev->flags);
2802 clear_bit(R5_ReWrite, &dev->flags);
2804 if (!rdev || !test_bit(In_sync, &rdev->flags)
2805 || test_bit(R5_ReadError, &dev->flags)) {
2809 set_bit(R5_Insync, &dev->flags);
2813 if (unlikely(blocked_rdev)) {
2814 if (s.syncing || s.expanding || s.expanded ||
2815 s.to_write || s.written) {
2816 set_bit(STRIPE_HANDLE, &sh->state);
2819 /* There is nothing for the blocked_rdev to block */
2820 rdev_dec_pending(blocked_rdev, conf->mddev);
2821 blocked_rdev = NULL;
2824 if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
2825 set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
2826 set_bit(STRIPE_BIOFILL_RUN, &sh->state);
2829 pr_debug("locked=%d uptodate=%d to_read=%d"
2830 " to_write=%d failed=%d failed_num=%d\n",
2831 s.locked, s.uptodate, s.to_read, s.to_write,
2832 s.failed, s.failed_num);
2833 /* check if the array has lost two devices and, if so, some requests might
2836 if (s.failed > 1 && s.to_read+s.to_write+s.written)
2837 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
2838 if (s.failed > 1 && s.syncing) {
2839 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2840 clear_bit(STRIPE_SYNCING, &sh->state);
2844 /* might be able to return some write requests if the parity block
2845 * is safe, or on a failed drive
2847 dev = &sh->dev[sh->pd_idx];
2849 ((test_bit(R5_Insync, &dev->flags) &&
2850 !test_bit(R5_LOCKED, &dev->flags) &&
2851 test_bit(R5_UPTODATE, &dev->flags)) ||
2852 (s.failed == 1 && s.failed_num == sh->pd_idx)))
2853 handle_stripe_clean_event(conf, sh, disks, &return_bi);
2855 /* Now we might consider reading some blocks, either to check/generate
2856 * parity, or to satisfy requests
2857 * or to load a block that is being partially written.
2859 if (s.to_read || s.non_overwrite ||
2860 (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
2861 handle_stripe_fill5(sh, &s, disks);
2863 /* Now we check to see if any write operations have recently
2867 if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
2869 if (sh->reconstruct_state == reconstruct_state_drain_result ||
2870 sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
2871 sh->reconstruct_state = reconstruct_state_idle;
2873 /* All the 'written' buffers and the parity block are ready to
2874 * be written back to disk
2876 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
2877 for (i = disks; i--; ) {
2879 if (test_bit(R5_LOCKED, &dev->flags) &&
2880 (i == sh->pd_idx || dev->written)) {
2881 pr_debug("Writing block %d\n", i);
2882 set_bit(R5_Wantwrite, &dev->flags);
2885 if (!test_bit(R5_Insync, &dev->flags) ||
2886 (i == sh->pd_idx && s.failed == 0))
2887 set_bit(STRIPE_INSYNC, &sh->state);
2890 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2891 atomic_dec(&conf->preread_active_stripes);
2892 if (atomic_read(&conf->preread_active_stripes) <
2894 md_wakeup_thread(conf->mddev->thread);
2898 /* Now to consider new write requests and what else, if anything
2899 * should be read. We do not handle new writes when:
2900 * 1/ A 'write' operation (copy+xor) is already in flight.
2901 * 2/ A 'check' operation is in flight, as it may clobber the parity
2904 if (s.to_write && !sh->reconstruct_state && !sh->check_state)
2905 handle_stripe_dirtying5(conf, sh, &s, disks);
2907 /* maybe we need to check and possibly fix the parity for this stripe
2908 * Any reads will already have been scheduled, so we just see if enough
2909 * data is available. The parity check is held off while parity
2910 * dependent operations are in flight.
2912 if (sh->check_state ||
2913 (s.syncing && s.locked == 0 &&
2914 !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
2915 !test_bit(STRIPE_INSYNC, &sh->state)))
2916 handle_parity_checks5(conf, sh, &s, disks);
2918 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
2919 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2920 clear_bit(STRIPE_SYNCING, &sh->state);
2923 /* If the failed drive is just a ReadError, then we might need to progress
2924 * the repair/check process
2926 if (s.failed == 1 && !conf->mddev->ro &&
2927 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2928 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2929 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
2931 dev = &sh->dev[s.failed_num];
2932 if (!test_bit(R5_ReWrite, &dev->flags)) {
2933 set_bit(R5_Wantwrite, &dev->flags);
2934 set_bit(R5_ReWrite, &dev->flags);
2935 set_bit(R5_LOCKED, &dev->flags);
2938 /* let's read it back */
2939 set_bit(R5_Wantread, &dev->flags);
2940 set_bit(R5_LOCKED, &dev->flags);
2945 /* Finish reconstruct operations initiated by the expansion process */
2946 if (sh->reconstruct_state == reconstruct_state_result) {
2947 sh->reconstruct_state = reconstruct_state_idle;
2948 clear_bit(STRIPE_EXPANDING, &sh->state);
2949 for (i = conf->raid_disks; i--; ) {
2950 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2951 set_bit(R5_LOCKED, &sh->dev[i].flags);
2956 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
2957 !sh->reconstruct_state) {
2958 /* Need to write out all blocks after computing parity */
2959 sh->disks = conf->raid_disks;
2960 stripe_set_idx(sh->sector, conf, 0, sh);
2961 schedule_reconstruction5(sh, &s, 1, 1);
2962 } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
2963 clear_bit(STRIPE_EXPAND_READY, &sh->state);
2964 atomic_dec(&conf->reshape_stripes);
2965 wake_up(&conf->wait_for_overlap);
2966 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2969 if (s.expanding && s.locked == 0 &&
2970 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
2971 handle_stripe_expansion(conf, sh, NULL);
2974 spin_unlock(&sh->lock);
2976 /* wait for this device to become unblocked */
2977 if (unlikely(blocked_rdev))
2978 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
2981 raid5_run_ops(sh, s.ops_request);
2985 return_io(return_bi);
2987 return blocked_rdev == NULL;
2990 static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
2992 raid5_conf_t *conf = sh->raid_conf;
2993 int disks = sh->disks;
2994 struct bio *return_bi = NULL;
2995 int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
2996 struct stripe_head_state s;
2997 struct r6_state r6s;
2998 struct r5dev *dev, *pdev, *qdev;
2999 mdk_rdev_t *blocked_rdev = NULL;
3001 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3002 "pd_idx=%d, qd_idx=%d\n",
3003 (unsigned long long)sh->sector, sh->state,
3004 atomic_read(&sh->count), pd_idx, qd_idx);
3005 memset(&s, 0, sizeof(s));
3007 spin_lock(&sh->lock);
3008 clear_bit(STRIPE_HANDLE, &sh->state);
3009 clear_bit(STRIPE_DELAYED, &sh->state);
3011 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
3012 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3013 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
3014 /* Now to look around and see what can be done */
3017 for (i=disks; i--; ) {
3020 clear_bit(R5_Insync, &dev->flags);
3022 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3023 i, dev->flags, dev->toread, dev->towrite, dev->written);
3024 /* maybe we can reply to a read */
3025 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
3026 struct bio *rbi, *rbi2;
3027 pr_debug("Return read for disc %d\n", i);
3028 spin_lock_irq(&conf->device_lock);
3031 if (test_and_clear_bit(R5_Overlap, &dev->flags))
3032 wake_up(&conf->wait_for_overlap);
3033 spin_unlock_irq(&conf->device_lock);
3034 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
3035 copy_data(0, rbi, dev->page, dev->sector);
3036 rbi2 = r5_next_bio(rbi, dev->sector);
3037 spin_lock_irq(&conf->device_lock);
3038 if (!raid5_dec_bi_phys_segments(rbi)) {
3039 rbi->bi_next = return_bi;
3042 spin_unlock_irq(&conf->device_lock);
3047 /* now count some things */
3048 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
3049 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
3056 if (!test_bit(R5_OVERWRITE, &dev->flags))
3061 rdev = rcu_dereference(conf->disks[i].rdev);
3062 if (blocked_rdev == NULL &&
3063 rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
3064 blocked_rdev = rdev;
3065 atomic_inc(&rdev->nr_pending);
3067 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
3068 /* The ReadError flag will just be confusing now */
3069 clear_bit(R5_ReadError, &dev->flags);
3070 clear_bit(R5_ReWrite, &dev->flags);
3072 if (!rdev || !test_bit(In_sync, &rdev->flags)
3073 || test_bit(R5_ReadError, &dev->flags)) {
3075 r6s.failed_num[s.failed] = i;
3078 set_bit(R5_Insync, &dev->flags);
3082 if (unlikely(blocked_rdev)) {
3083 if (s.syncing || s.expanding || s.expanded ||
3084 s.to_write || s.written) {
3085 set_bit(STRIPE_HANDLE, &sh->state);
3088 /* There is nothing for the blocked_rdev to block */
3089 rdev_dec_pending(blocked_rdev, conf->mddev);
3090 blocked_rdev = NULL;
3093 pr_debug("locked=%d uptodate=%d to_read=%d"
3094 " to_write=%d failed=%d failed_num=%d,%d\n",
3095 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
3096 r6s.failed_num[0], r6s.failed_num[1]);
3097 /* check if the array has lost >2 devices and, if so, some requests
3098 * might need to be failed
3100 if (s.failed > 2 && s.to_read+s.to_write+s.written)
3101 handle_failed_stripe(conf, sh, &s, disks, &return_bi);
3102 if (s.failed > 2 && s.syncing) {
3103 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
3104 clear_bit(STRIPE_SYNCING, &sh->state);
3109 * might be able to return some write requests if the parity blocks
3110 * are safe, or on a failed drive
3112 pdev = &sh->dev[pd_idx];
3113 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
3114 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
3115 qdev = &sh->dev[qd_idx];
3116 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
3117 || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
3120 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
3121 && !test_bit(R5_LOCKED, &pdev->flags)
3122 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
3123 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
3124 && !test_bit(R5_LOCKED, &qdev->flags)
3125 && test_bit(R5_UPTODATE, &qdev->flags)))))
3126 handle_stripe_clean_event(conf, sh, disks, &return_bi);
3128 /* Now we might consider reading some blocks, either to check/generate
3129 * parity, or to satisfy requests
3130 * or to load a block that is being partially written.
3132 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
3133 (s.syncing && (s.uptodate < disks)) || s.expanding)
3134 handle_stripe_fill6(sh, &s, &r6s, disks);
3136 /* now to consider writing and what else, if anything should be read */
3138 handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
3140 /* maybe we need to check and possibly fix the parity for this stripe
3141 * Any reads will already have been scheduled, so we just see if enough
3144 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
3145 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
3147 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
3148 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
3149 clear_bit(STRIPE_SYNCING, &sh->state);
3152 /* If the failed drives are just a ReadError, then we might need
3153 * to progress the repair/check process
3155 if (s.failed <= 2 && !conf->mddev->ro)
3156 for (i = 0; i < s.failed; i++) {
3157 dev = &sh->dev[r6s.failed_num[i]];
3158 if (test_bit(R5_ReadError, &dev->flags)
3159 && !test_bit(R5_LOCKED, &dev->flags)
3160 && test_bit(R5_UPTODATE, &dev->flags)
3162 if (!test_bit(R5_ReWrite, &dev->flags)) {
3163 set_bit(R5_Wantwrite, &dev->flags);
3164 set_bit(R5_ReWrite, &dev->flags);
3165 set_bit(R5_LOCKED, &dev->flags);
3167 /* let's read it back */
3168 set_bit(R5_Wantread, &dev->flags);
3169 set_bit(R5_LOCKED, &dev->flags);
3174 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
3175 /* Need to write out all blocks after computing P&Q */
3176 sh->disks = conf->raid_disks;
3177 stripe_set_idx(sh->sector, conf, 0, sh);
3178 compute_parity6(sh, RECONSTRUCT_WRITE);
3179 for (i = conf->raid_disks ; i-- ; ) {
3180 set_bit(R5_LOCKED, &sh->dev[i].flags);
3182 set_bit(R5_Wantwrite, &sh->dev[i].flags);
3184 clear_bit(STRIPE_EXPANDING, &sh->state);
3185 } else if (s.expanded) {
3186 clear_bit(STRIPE_EXPAND_READY, &sh->state);
3187 atomic_dec(&conf->reshape_stripes);
3188 wake_up(&conf->wait_for_overlap);
3189 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
3192 if (s.expanding && s.locked == 0 &&
3193 !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
3194 handle_stripe_expansion(conf, sh, &r6s);
3197 spin_unlock(&sh->lock);
3199 /* wait for this device to become unblocked */
3200 if (unlikely(blocked_rdev))
3201 md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
3205 return_io(return_bi);
3207 return blocked_rdev == NULL;
3210 /* returns true if the stripe was handled */
3211 static bool handle_stripe(struct stripe_head *sh, struct page *tmp_page)
3213 if (sh->raid_conf->level == 6)
3214 return handle_stripe6(sh, tmp_page);
3216 return handle_stripe5(sh);
3221 static void raid5_activate_delayed(raid5_conf_t *conf)
3223 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3224 while (!list_empty(&conf->delayed_list)) {
3225 struct list_head *l = conf->delayed_list.next;
3226 struct stripe_head *sh;
3227 sh = list_entry(l, struct stripe_head, lru);
3229 clear_bit(STRIPE_DELAYED, &sh->state);
3230 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3231 atomic_inc(&conf->preread_active_stripes);
3232 list_add_tail(&sh->lru, &conf->hold_list);
3235 blk_plug_device(conf->mddev->queue);
3238 static void activate_bit_delay(raid5_conf_t *conf)
3240 /* device_lock is held */
3241 struct list_head head;
3242 list_add(&head, &conf->bitmap_list);
3243 list_del_init(&conf->bitmap_list);
3244 while (!list_empty(&head)) {
3245 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3246 list_del_init(&sh->lru);
3247 atomic_inc(&sh->count);
3248 __release_stripe(conf, sh);
3252 static void unplug_slaves(mddev_t *mddev)
3254 raid5_conf_t *conf = mddev_to_conf(mddev);
3258 for (i=0; i<mddev->raid_disks; i++) {
3259 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
3260 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
3261 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
3263 atomic_inc(&rdev->nr_pending);
3266 blk_unplug(r_queue);
3268 rdev_dec_pending(rdev, mddev);
3275 static void raid5_unplug_device(struct request_queue *q)
3277 mddev_t *mddev = q->queuedata;
3278 raid5_conf_t *conf = mddev_to_conf(mddev);
3279 unsigned long flags;
3281 spin_lock_irqsave(&conf->device_lock, flags);
3283 if (blk_remove_plug(q)) {
3285 raid5_activate_delayed(conf);
3287 md_wakeup_thread(mddev->thread);
3289 spin_unlock_irqrestore(&conf->device_lock, flags);
3291 unplug_slaves(mddev);
3294 static int raid5_congested(void *data, int bits)
3296 mddev_t *mddev = data;
3297 raid5_conf_t *conf = mddev_to_conf(mddev);
3299 /* No difference between reads and writes. Just check
3300 * how busy the stripe_cache is
3302 if (conf->inactive_blocked)
3306 if (list_empty_careful(&conf->inactive_list))
3312 /* We want read requests to align with chunks where possible,
3313 * but write requests don't need to.
3315 static int raid5_mergeable_bvec(struct request_queue *q,
3316 struct bvec_merge_data *bvm,
3317 struct bio_vec *biovec)
3319 mddev_t *mddev = q->queuedata;
3320 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
3322 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3323 unsigned int bio_sectors = bvm->bi_size >> 9;
3325 if ((bvm->bi_rw & 1) == WRITE)
3326 return biovec->bv_len; /* always allow writes to be mergeable */
3328 if (mddev->new_chunk < mddev->chunk_size)
3329 chunk_sectors = mddev->new_chunk >> 9;
3330 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3331 if (max < 0) max = 0;
3332 if (max <= biovec->bv_len && bio_sectors == 0)
3333 return biovec->bv_len;
3339 static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3341 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3342 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3343 unsigned int bio_sectors = bio->bi_size >> 9;
3345 if (mddev->new_chunk < mddev->chunk_size)
3346 chunk_sectors = mddev->new_chunk >> 9;
3347 return chunk_sectors >=
3348 ((sector & (chunk_sectors - 1)) + bio_sectors);
3352 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3353 * later sampled by raid5d.
3355 static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3357 unsigned long flags;
3359 spin_lock_irqsave(&conf->device_lock, flags);
3361 bi->bi_next = conf->retry_read_aligned_list;
3362 conf->retry_read_aligned_list = bi;
3364 spin_unlock_irqrestore(&conf->device_lock, flags);
3365 md_wakeup_thread(conf->mddev->thread);
3369 static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3373 bi = conf->retry_read_aligned;
3375 conf->retry_read_aligned = NULL;
3378 bi = conf->retry_read_aligned_list;
3380 conf->retry_read_aligned_list = bi->bi_next;
3383 * this sets the active strip count to 1 and the processed
3384 * strip count to zero (upper 8 bits)
3386 bi->bi_phys_segments = 1; /* biased count of active stripes */
3394 * The "raid5_align_endio" should check if the read succeeded and if it
3395 * did, call bio_endio on the original bio (having bio_put the new bio
3397 * If the read failed..
3399 static void raid5_align_endio(struct bio *bi, int error)
3401 struct bio* raid_bi = bi->bi_private;
3404 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3409 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
3410 conf = mddev_to_conf(mddev);
3411 rdev = (void*)raid_bi->bi_next;
3412 raid_bi->bi_next = NULL;
3414 rdev_dec_pending(rdev, conf->mddev);
3416 if (!error && uptodate) {
3417 bio_endio(raid_bi, 0);
3418 if (atomic_dec_and_test(&conf->active_aligned_reads))
3419 wake_up(&conf->wait_for_stripe);
3424 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3426 add_bio_to_retry(raid_bi, conf);
3429 static int bio_fits_rdev(struct bio *bi)
3431 struct request_queue *q = bdev_get_queue(bi->bi_bdev);
3433 if ((bi->bi_size>>9) > q->max_sectors)
3435 blk_recount_segments(q, bi);
3436 if (bi->bi_phys_segments > q->max_phys_segments)
3439 if (q->merge_bvec_fn)
3440 /* it's too hard to apply the merge_bvec_fn at this stage,
3449 static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
3451 mddev_t *mddev = q->queuedata;
3452 raid5_conf_t *conf = mddev_to_conf(mddev);
3453 unsigned int dd_idx;
3454 struct bio* align_bi;
3457 if (!in_chunk_boundary(mddev, raid_bio)) {
3458 pr_debug("chunk_aligned_read : non aligned\n");
3462 * use bio_clone to make a copy of the bio
3464 align_bi = bio_clone(raid_bio, GFP_NOIO);
3468 * set bi_end_io to a new function, and set bi_private to the
3471 align_bi->bi_end_io = raid5_align_endio;
3472 align_bi->bi_private = raid_bio;
3476 align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector,
3481 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3482 if (rdev && test_bit(In_sync, &rdev->flags)) {
3483 atomic_inc(&rdev->nr_pending);
3485 raid_bio->bi_next = (void*)rdev;
3486 align_bi->bi_bdev = rdev->bdev;
3487 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3488 align_bi->bi_sector += rdev->data_offset;
3490 if (!bio_fits_rdev(align_bi)) {
3491 /* too big in some way */
3493 rdev_dec_pending(rdev, mddev);
3497 spin_lock_irq(&conf->device_lock);
3498 wait_event_lock_irq(conf->wait_for_stripe,
3500 conf->device_lock, /* nothing */);
3501 atomic_inc(&conf->active_aligned_reads);
3502 spin_unlock_irq(&conf->device_lock);
3504 generic_make_request(align_bi);
3513 /* __get_priority_stripe - get the next stripe to process
3515 * Full stripe writes are allowed to pass preread active stripes up until
3516 * the bypass_threshold is exceeded. In general the bypass_count
3517 * increments when the handle_list is handled before the hold_list; however, it
3518 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3519 * stripe with in flight i/o. The bypass_count will be reset when the
3520 * head of the hold_list has changed, i.e. the head was promoted to the
3523 static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
3525 struct stripe_head *sh;
3527 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3529 list_empty(&conf->handle_list) ? "empty" : "busy",
3530 list_empty(&conf->hold_list) ? "empty" : "busy",
3531 atomic_read(&conf->pending_full_writes), conf->bypass_count);
3533 if (!list_empty(&conf->handle_list)) {
3534 sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
3536 if (list_empty(&conf->hold_list))
3537 conf->bypass_count = 0;
3538 else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
3539 if (conf->hold_list.next == conf->last_hold)
3540 conf->bypass_count++;
3542 conf->last_hold = conf->hold_list.next;
3543 conf->bypass_count -= conf->bypass_threshold;
3544 if (conf->bypass_count < 0)
3545 conf->bypass_count = 0;
3548 } else if (!list_empty(&conf->hold_list) &&
3549 ((conf->bypass_threshold &&
3550 conf->bypass_count > conf->bypass_threshold) ||
3551 atomic_read(&conf->pending_full_writes) == 0)) {
3552 sh = list_entry(conf->hold_list.next,
3554 conf->bypass_count -= conf->bypass_threshold;
3555 if (conf->bypass_count < 0)
3556 conf->bypass_count = 0;
3560 list_del_init(&sh->lru);
3561 atomic_inc(&sh->count);
3562 BUG_ON(atomic_read(&sh->count) != 1);
3566 static int make_request(struct request_queue *q, struct bio * bi)
3568 mddev_t *mddev = q->queuedata;
3569 raid5_conf_t *conf = mddev_to_conf(mddev);
3571 sector_t new_sector;
3572 sector_t logical_sector, last_sector;
3573 struct stripe_head *sh;
3574 const int rw = bio_data_dir(bi);
3577 if (unlikely(bio_barrier(bi))) {
3578 bio_endio(bi, -EOPNOTSUPP);
3582 md_write_start(mddev, bi);
3584 cpu = part_stat_lock();
3585 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
3586 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
3591 mddev->reshape_position == MaxSector &&
3592 chunk_aligned_read(q,bi))
3595 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3596 last_sector = bi->bi_sector + (bi->bi_size>>9);
3598 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
3600 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3602 int disks, data_disks;
3607 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
3608 if (likely(conf->reshape_progress == MaxSector))
3609 disks = conf->raid_disks;
3611 /* spinlock is needed as reshape_progress may be
3612 * 64bit on a 32bit platform, and so it might be
3613 * possible to see a half-updated value
3614 * Ofcourse reshape_progress could change after
3615 * the lock is dropped, so once we get a reference
3616 * to the stripe that we think it is, we will have
3619 spin_lock_irq(&conf->device_lock);
3620 disks = conf->raid_disks;
3621 if (mddev->delta_disks < 0
3622 ? logical_sector < conf->reshape_progress
3623 : logical_sector >= conf->reshape_progress) {
3624 disks = conf->previous_raid_disks;
3627 if (mddev->delta_disks < 0
3628 ? logical_sector < conf->reshape_safe
3629 : logical_sector >= conf->reshape_safe) {
3630 spin_unlock_irq(&conf->device_lock);
3635 spin_unlock_irq(&conf->device_lock);
3637 data_disks = disks - conf->max_degraded;
3639 new_sector = raid5_compute_sector(conf, logical_sector,
3642 pr_debug("raid5: make_request, sector %llu logical %llu\n",
3643 (unsigned long long)new_sector,
3644 (unsigned long long)logical_sector);
3646 sh = get_active_stripe(conf, new_sector, previous,
3647 (bi->bi_rw&RWA_MASK));
3649 if (unlikely(conf->reshape_progress != MaxSector)) {
3650 /* expansion might have moved on while waiting for a
3651 * stripe, so we must do the range check again.
3652 * Expansion could still move past after this
3653 * test, but as we are holding a reference to
3654 * 'sh', we know that if that happens,
3655 * STRIPE_EXPANDING will get set and the expansion
3656 * won't proceed until we finish with the stripe.
3659 spin_lock_irq(&conf->device_lock);
3660 if ((mddev->delta_disks < 0
3661 ? logical_sector >= conf->reshape_progress
3662 : logical_sector < conf->reshape_progress)
3664 /* mismatch, need to try again */
3666 spin_unlock_irq(&conf->device_lock);
3672 /* FIXME what if we get a false positive because these
3673 * are being updated.
3675 if (logical_sector >= mddev->suspend_lo &&
3676 logical_sector < mddev->suspend_hi) {
3682 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3683 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3684 /* Stripe is busy expanding or
3685 * add failed due to overlap. Flush everything
3688 raid5_unplug_device(mddev->queue);
3693 finish_wait(&conf->wait_for_overlap, &w);
3694 set_bit(STRIPE_HANDLE, &sh->state);
3695 clear_bit(STRIPE_DELAYED, &sh->state);
3698 /* cannot get stripe for read-ahead, just give-up */
3699 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3700 finish_wait(&conf->wait_for_overlap, &w);
3705 spin_lock_irq(&conf->device_lock);
3706 remaining = raid5_dec_bi_phys_segments(bi);
3707 spin_unlock_irq(&conf->device_lock);
3708 if (remaining == 0) {
3711 md_write_end(mddev);
3718 static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
3720 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
3722 /* reshaping is quite different to recovery/resync so it is
3723 * handled quite separately ... here.
3725 * On each call to sync_request, we gather one chunk worth of
3726 * destination stripes and flag them as expanding.
3727 * Then we find all the source stripes and request reads.
3728 * As the reads complete, handle_stripe will copy the data
3729 * into the destination stripe and release that stripe.
3731 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3732 struct stripe_head *sh;
3733 sector_t first_sector, last_sector;
3734 int raid_disks = conf->previous_raid_disks;
3735 int data_disks = raid_disks - conf->max_degraded;
3736 int new_data_disks = conf->raid_disks - conf->max_degraded;
3739 sector_t writepos, safepos, gap;
3740 sector_t stripe_addr;
3742 if (sector_nr == 0) {
3743 /* If restarting in the middle, skip the initial sectors */
3744 if (mddev->delta_disks < 0 &&
3745 conf->reshape_progress < raid5_size(mddev, 0, 0)) {
3746 sector_nr = raid5_size(mddev, 0, 0)
3747 - conf->reshape_progress;
3748 } else if (mddev->delta_disks > 0 &&
3749 conf->reshape_progress > 0)
3750 sector_nr = conf->reshape_progress;
3751 sector_div(sector_nr, new_data_disks);
3758 /* we update the metadata when there is more than 3Meg
3759 * in the block range (that is rather arbitrary, should
3760 * probably be time based) or when the data about to be
3761 * copied would over-write the source of the data at
3762 * the front of the range.
3763 * i.e. one new_stripe along from reshape_progress new_maps
3764 * to after where reshape_safe old_maps to
3766 writepos = conf->reshape_progress;
3767 sector_div(writepos, new_data_disks);
3768 safepos = conf->reshape_safe;
3769 sector_div(safepos, data_disks);
3770 if (mddev->delta_disks < 0) {
3771 writepos -= conf->chunk_size/512;
3772 safepos += conf->chunk_size/512;
3773 gap = conf->reshape_safe - conf->reshape_progress;
3775 writepos += conf->chunk_size/512;
3776 safepos -= conf->chunk_size/512;
3777 gap = conf->reshape_progress - conf->reshape_safe;
3780 if ((mddev->delta_disks < 0
3781 ? writepos < safepos
3782 : writepos > safepos) ||
3783 gap > (new_data_disks)*3000*2 /*3Meg*/) {
3784 /* Cannot proceed until we've updated the superblock... */
3785 wait_event(conf->wait_for_overlap,
3786 atomic_read(&conf->reshape_stripes)==0);
3787 mddev->reshape_position = conf->reshape_progress;
3788 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3789 md_wakeup_thread(mddev->thread);
3790 wait_event(mddev->sb_wait, mddev->flags == 0 ||
3791 kthread_should_stop());
3792 spin_lock_irq(&conf->device_lock);
3793 conf->reshape_safe = mddev->reshape_position;
3794 spin_unlock_irq(&conf->device_lock);
3795 wake_up(&conf->wait_for_overlap);
3798 if (mddev->delta_disks < 0) {
3799 BUG_ON(conf->reshape_progress == 0);
3800 stripe_addr = writepos;
3801 BUG_ON((mddev->dev_sectors &
3802 ~((sector_t)conf->chunk_size / 512 - 1))
3803 - (conf->chunk_size / 512) - stripe_addr
3806 BUG_ON(writepos != sector_nr + conf->chunk_size / 512);
3807 stripe_addr = sector_nr;
3809 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
3812 sh = get_active_stripe(conf, stripe_addr+i, 0, 0);
3813 set_bit(STRIPE_EXPANDING, &sh->state);
3814 atomic_inc(&conf->reshape_stripes);
3815 /* If any of this stripe is beyond the end of the old
3816 * array, then we need to zero those blocks
3818 for (j=sh->disks; j--;) {
3820 if (j == sh->pd_idx)
3822 if (conf->level == 6 &&
3825 s = compute_blocknr(sh, j, 0);
3826 if (s < raid5_size(mddev, 0, 0)) {
3830 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3831 set_bit(R5_Expanded, &sh->dev[j].flags);
3832 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3835 set_bit(STRIPE_EXPAND_READY, &sh->state);
3836 set_bit(STRIPE_HANDLE, &sh->state);
3840 spin_lock_irq(&conf->device_lock);
3841 if (mddev->delta_disks < 0)
3842 conf->reshape_progress -= i * new_data_disks;
3844 conf->reshape_progress += i * new_data_disks;
3845 spin_unlock_irq(&conf->device_lock);
3846 /* Ok, those stripe are ready. We can start scheduling
3847 * reads on the source stripes.
3848 * The source stripes are determined by mapping the first and last
3849 * block on the destination stripes.
3852 raid5_compute_sector(conf, stripe_addr*(new_data_disks),
3855 raid5_compute_sector(conf, ((stripe_addr+conf->chunk_size/512)
3856 *(new_data_disks) - 1),
3858 if (last_sector >= mddev->dev_sectors)
3859 last_sector = mddev->dev_sectors - 1;
3860 while (first_sector <= last_sector) {
3861 sh = get_active_stripe(conf, first_sector, 1, 0);
3862 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3863 set_bit(STRIPE_HANDLE, &sh->state);
3865 first_sector += STRIPE_SECTORS;
3867 /* If this takes us to the resync_max point where we have to pause,
3868 * then we need to write out the superblock.
3870 sector_nr += conf->chunk_size>>9;
3871 if (sector_nr >= mddev->resync_max) {
3872 /* Cannot proceed until we've updated the superblock... */
3873 wait_event(conf->wait_for_overlap,
3874 atomic_read(&conf->reshape_stripes) == 0);
3875 mddev->reshape_position = conf->reshape_progress;
3876 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3877 md_wakeup_thread(mddev->thread);
3878 wait_event(mddev->sb_wait,
3879 !test_bit(MD_CHANGE_DEVS, &mddev->flags)
3880 || kthread_should_stop());
3881 spin_lock_irq(&conf->device_lock);
3882 conf->reshape_safe = mddev->reshape_position;
3883 spin_unlock_irq(&conf->device_lock);
3884 wake_up(&conf->wait_for_overlap);
3886 return conf->chunk_size>>9;
3889 /* FIXME go_faster isn't used */
3890 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3892 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3893 struct stripe_head *sh;
3894 sector_t max_sector = mddev->dev_sectors;
3896 int still_degraded = 0;
3899 if (sector_nr >= max_sector) {
3900 /* just being told to finish up .. nothing much to do */
3901 unplug_slaves(mddev);
3903 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3908 if (mddev->curr_resync < max_sector) /* aborted */
3909 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3911 else /* completed sync */
3913 bitmap_close_sync(mddev->bitmap);
3918 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3919 return reshape_request(mddev, sector_nr, skipped);
3921 /* No need to check resync_max as we never do more than one
3922 * stripe, and as resync_max will always be on a chunk boundary,
3923 * if the check in md_do_sync didn't fire, there is no chance
3924 * of overstepping resync_max here
3927 /* if there is too many failed drives and we are trying
3928 * to resync, then assert that we are finished, because there is
3929 * nothing we can do.
3931 if (mddev->degraded >= conf->max_degraded &&
3932 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3933 sector_t rv = mddev->dev_sectors - sector_nr;
3937 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
3938 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
3939 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3940 /* we can skip this block, and probably more */
3941 sync_blocks /= STRIPE_SECTORS;
3943 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3947 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
3949 sh = get_active_stripe(conf, sector_nr, 0, 1);
3951 sh = get_active_stripe(conf, sector_nr, 0, 0);
3952 /* make sure we don't swamp the stripe cache if someone else
3953 * is trying to get access
3955 schedule_timeout_uninterruptible(1);
3957 /* Need to check if array will still be degraded after recovery/resync
3958 * We don't need to check the 'failed' flag as when that gets set,
3961 for (i=0; i<mddev->raid_disks; i++)
3962 if (conf->disks[i].rdev == NULL)
3965 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
3967 spin_lock(&sh->lock);
3968 set_bit(STRIPE_SYNCING, &sh->state);
3969 clear_bit(STRIPE_INSYNC, &sh->state);
3970 spin_unlock(&sh->lock);
3972 /* wait for any blocked device to be handled */
3973 while(unlikely(!handle_stripe(sh, NULL)))
3977 return STRIPE_SECTORS;
3980 static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
3982 /* We may not be able to submit a whole bio at once as there
3983 * may not be enough stripe_heads available.
3984 * We cannot pre-allocate enough stripe_heads as we may need
3985 * more than exist in the cache (if we allow ever large chunks).
3986 * So we do one stripe head at a time and record in
3987 * ->bi_hw_segments how many have been done.
3989 * We *know* that this entire raid_bio is in one chunk, so
3990 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3992 struct stripe_head *sh;
3994 sector_t sector, logical_sector, last_sector;
3999 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
4000 sector = raid5_compute_sector(conf, logical_sector,
4002 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
4004 for (; logical_sector < last_sector;
4005 logical_sector += STRIPE_SECTORS,
4006 sector += STRIPE_SECTORS,
4009 if (scnt < raid5_bi_hw_segments(raid_bio))
4010 /* already done this stripe */
4013 sh = get_active_stripe(conf, sector, 0, 1);
4016 /* failed to get a stripe - must wait */
4017 raid5_set_bi_hw_segments(raid_bio, scnt);
4018 conf->retry_read_aligned = raid_bio;
4022 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
4023 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
4025 raid5_set_bi_hw_segments(raid_bio, scnt);
4026 conf->retry_read_aligned = raid_bio;
4030 handle_stripe(sh, NULL);
4034 spin_lock_irq(&conf->device_lock);
4035 remaining = raid5_dec_bi_phys_segments(raid_bio);
4036 spin_unlock_irq(&conf->device_lock);
4038 bio_endio(raid_bio, 0);
4039 if (atomic_dec_and_test(&conf->active_aligned_reads))
4040 wake_up(&conf->wait_for_stripe);
4047 * This is our raid5 kernel thread.
4049 * We scan the hash table for stripes which can be handled now.
4050 * During the scan, completed stripes are saved for us by the interrupt
4051 * handler, so that they will not have to wait for our next wakeup.
4053 static void raid5d(mddev_t *mddev)
4055 struct stripe_head *sh;
4056 raid5_conf_t *conf = mddev_to_conf(mddev);
4059 pr_debug("+++ raid5d active\n");
4061 md_check_recovery(mddev);
4064 spin_lock_irq(&conf->device_lock);
4068 if (conf->seq_flush != conf->seq_write) {
4069 int seq = conf->seq_flush;
4070 spin_unlock_irq(&conf->device_lock);
4071 bitmap_unplug(mddev->bitmap);
4072 spin_lock_irq(&conf->device_lock);
4073 conf->seq_write = seq;
4074 activate_bit_delay(conf);
4077 while ((bio = remove_bio_from_retry(conf))) {
4079 spin_unlock_irq(&conf->device_lock);
4080 ok = retry_aligned_read(conf, bio);
4081 spin_lock_irq(&conf->device_lock);
4087 sh = __get_priority_stripe(conf);
4091 spin_unlock_irq(&conf->device_lock);
4094 handle_stripe(sh, conf->spare_page);
4097 spin_lock_irq(&conf->device_lock);
4099 pr_debug("%d stripes handled\n", handled);
4101 spin_unlock_irq(&conf->device_lock);
4103 async_tx_issue_pending_all();
4104 unplug_slaves(mddev);
4106 pr_debug("--- raid5d inactive\n");
4110 raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
4112 raid5_conf_t *conf = mddev_to_conf(mddev);
4114 return sprintf(page, "%d\n", conf->max_nr_stripes);
4120 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
4122 raid5_conf_t *conf = mddev_to_conf(mddev);
4126 if (len >= PAGE_SIZE)
4131 if (strict_strtoul(page, 10, &new))
4133 if (new <= 16 || new > 32768)
4135 while (new < conf->max_nr_stripes) {
4136 if (drop_one_stripe(conf))
4137 conf->max_nr_stripes--;
4141 err = md_allow_write(mddev);
4144 while (new > conf->max_nr_stripes) {
4145 if (grow_one_stripe(conf))
4146 conf->max_nr_stripes++;
4152 static struct md_sysfs_entry
4153 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
4154 raid5_show_stripe_cache_size,
4155 raid5_store_stripe_cache_size);
4158 raid5_show_preread_threshold(mddev_t *mddev, char *page)
4160 raid5_conf_t *conf = mddev_to_conf(mddev);
4162 return sprintf(page, "%d\n", conf->bypass_threshold);
4168 raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
4170 raid5_conf_t *conf = mddev_to_conf(mddev);
4172 if (len >= PAGE_SIZE)
4177 if (strict_strtoul(page, 10, &new))
4179 if (new > conf->max_nr_stripes)
4181 conf->bypass_threshold = new;
4185 static struct md_sysfs_entry
4186 raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
4188 raid5_show_preread_threshold,
4189 raid5_store_preread_threshold);
4192 stripe_cache_active_show(mddev_t *mddev, char *page)
4194 raid5_conf_t *conf = mddev_to_conf(mddev);
4196 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
4201 static struct md_sysfs_entry
4202 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
4204 static struct attribute *raid5_attrs[] = {
4205 &raid5_stripecache_size.attr,
4206 &raid5_stripecache_active.attr,
4207 &raid5_preread_bypass_threshold.attr,
4210 static struct attribute_group raid5_attrs_group = {
4212 .attrs = raid5_attrs,
4216 raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks)
4218 raid5_conf_t *conf = mddev_to_conf(mddev);
4221 sectors = mddev->dev_sectors;
4223 /* size is defined by the smallest of previous and new size */
4224 if (conf->raid_disks < conf->previous_raid_disks)
4225 raid_disks = conf->raid_disks;
4227 raid_disks = conf->previous_raid_disks;
4230 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
4231 sectors &= ~((sector_t)mddev->new_chunk/512 - 1);
4232 return sectors * (raid_disks - conf->max_degraded);
4235 static raid5_conf_t *setup_conf(mddev_t *mddev)
4238 int raid_disk, memory;
4240 struct disk_info *disk;
4242 if (mddev->new_level != 5
4243 && mddev->new_level != 4
4244 && mddev->new_level != 6) {
4245 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
4246 mdname(mddev), mddev->new_level);
4247 return ERR_PTR(-EIO);
4249 if ((mddev->new_level == 5
4250 && !algorithm_valid_raid5(mddev->new_layout)) ||
4251 (mddev->new_level == 6
4252 && !algorithm_valid_raid6(mddev->new_layout))) {
4253 printk(KERN_ERR "raid5: %s: layout %d not supported\n",
4254 mdname(mddev), mddev->new_layout);
4255 return ERR_PTR(-EIO);
4257 if (mddev->new_level == 6 && mddev->raid_disks < 4) {
4258 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4259 mdname(mddev), mddev->raid_disks);
4260 return ERR_PTR(-EINVAL);
4263 if (!mddev->new_chunk || mddev->new_chunk % PAGE_SIZE) {
4264 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
4265 mddev->new_chunk, mdname(mddev));
4266 return ERR_PTR(-EINVAL);
4269 conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
4273 conf->raid_disks = mddev->raid_disks;
4274 if (mddev->reshape_position == MaxSector)
4275 conf->previous_raid_disks = mddev->raid_disks;
4277 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4279 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
4284 conf->mddev = mddev;
4286 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4289 if (mddev->new_level == 6) {
4290 conf->spare_page = alloc_page(GFP_KERNEL);
4291 if (!conf->spare_page)
4294 spin_lock_init(&conf->device_lock);
4295 init_waitqueue_head(&conf->wait_for_stripe);
4296 init_waitqueue_head(&conf->wait_for_overlap);
4297 INIT_LIST_HEAD(&conf->handle_list);
4298 INIT_LIST_HEAD(&conf->hold_list);
4299 INIT_LIST_HEAD(&conf->delayed_list);
4300 INIT_LIST_HEAD(&conf->bitmap_list);
4301 INIT_LIST_HEAD(&conf->inactive_list);
4302 atomic_set(&conf->active_stripes, 0);
4303 atomic_set(&conf->preread_active_stripes, 0);
4304 atomic_set(&conf->active_aligned_reads, 0);
4305 conf->bypass_threshold = BYPASS_THRESHOLD;
4307 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
4309 list_for_each_entry(rdev, &mddev->disks, same_set) {
4310 raid_disk = rdev->raid_disk;
4311 if (raid_disk >= conf->raid_disks
4314 disk = conf->disks + raid_disk;
4318 if (test_bit(In_sync, &rdev->flags)) {
4319 char b[BDEVNAME_SIZE];
4320 printk(KERN_INFO "raid5: device %s operational as raid"
4321 " disk %d\n", bdevname(rdev->bdev,b),
4324 /* Cannot rely on bitmap to complete recovery */
4328 conf->chunk_size = mddev->new_chunk;
4329 conf->level = mddev->new_level;
4330 if (conf->level == 6)
4331 conf->max_degraded = 2;
4333 conf->max_degraded = 1;
4334 conf->algorithm = mddev->new_layout;
4335 conf->max_nr_stripes = NR_STRIPES;
4336 conf->reshape_progress = mddev->reshape_position;
4337 if (conf->reshape_progress != MaxSector) {
4338 conf->prev_chunk = mddev->chunk_size;
4339 conf->prev_algo = mddev->layout;
4342 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4343 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4344 if (grow_stripes(conf, conf->max_nr_stripes)) {
4346 "raid5: couldn't allocate %dkB for buffers\n", memory);
4349 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4350 memory, mdname(mddev));
4352 conf->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4353 if (!conf->thread) {
4355 "raid5: couldn't allocate thread for %s\n",
4364 shrink_stripes(conf);
4365 safe_put_page(conf->spare_page);
4367 kfree(conf->stripe_hashtbl);
4369 return ERR_PTR(-EIO);
4371 return ERR_PTR(-ENOMEM);
4374 static int run(mddev_t *mddev)
4377 int working_disks = 0;
4380 if (mddev->reshape_position != MaxSector) {
4381 /* Check that we can continue the reshape.
4382 * Currently only disks can change, it must
4383 * increase, and we must be past the point where
4384 * a stripe over-writes itself
4386 sector_t here_new, here_old;
4388 int max_degraded = (mddev->level == 6 ? 2 : 1);
4390 if (mddev->new_level != mddev->level ||
4391 mddev->new_layout != mddev->layout ||
4392 mddev->new_chunk != mddev->chunk_size) {
4393 printk(KERN_ERR "raid5: %s: unsupported reshape "
4394 "required - aborting.\n",
4398 old_disks = mddev->raid_disks - mddev->delta_disks;
4399 /* reshape_position must be on a new-stripe boundary, and one
4400 * further up in new geometry must map after here in old
4403 here_new = mddev->reshape_position;
4404 if (sector_div(here_new, (mddev->new_chunk>>9)*
4405 (mddev->raid_disks - max_degraded))) {
4406 printk(KERN_ERR "raid5: reshape_position not "
4407 "on a stripe boundary\n");
4410 /* here_new is the stripe we will write to */
4411 here_old = mddev->reshape_position;
4412 sector_div(here_old, (mddev->chunk_size>>9)*
4413 (old_disks-max_degraded));
4414 /* here_old is the first stripe that we might need to read
4416 if (here_new >= here_old) {
4417 /* Reading from the same stripe as writing to - bad */
4418 printk(KERN_ERR "raid5: reshape_position too early for "
4419 "auto-recovery - aborting.\n");
4422 printk(KERN_INFO "raid5: reshape will continue\n");
4423 /* OK, we should be able to continue; */
4425 BUG_ON(mddev->level != mddev->new_level);
4426 BUG_ON(mddev->layout != mddev->new_layout);
4427 BUG_ON(mddev->chunk_size != mddev->new_chunk);
4428 BUG_ON(mddev->delta_disks != 0);
4431 if (mddev->private == NULL)
4432 conf = setup_conf(mddev);
4434 conf = mddev->private;
4437 return PTR_ERR(conf);
4439 mddev->thread = conf->thread;
4440 conf->thread = NULL;
4441 mddev->private = conf;
4444 * 0 for a fully functional array, 1 or 2 for a degraded array.
4446 list_for_each_entry(rdev, &mddev->disks, same_set)
4447 if (rdev->raid_disk >= 0 &&
4448 test_bit(In_sync, &rdev->flags))
4451 mddev->degraded = conf->raid_disks - working_disks;
4453 if (mddev->degraded > conf->max_degraded) {
4454 printk(KERN_ERR "raid5: not enough operational devices for %s"
4455 " (%d/%d failed)\n",
4456 mdname(mddev), mddev->degraded, conf->raid_disks);
4460 /* device size must be a multiple of chunk size */
4461 mddev->dev_sectors &= ~(mddev->chunk_size / 512 - 1);
4462 mddev->resync_max_sectors = mddev->dev_sectors;
4464 if (mddev->degraded > 0 &&
4465 mddev->recovery_cp != MaxSector) {
4466 if (mddev->ok_start_degraded)
4468 "raid5: starting dirty degraded array: %s"
4469 "- data corruption possible.\n",
4473 "raid5: cannot start dirty degraded array for %s\n",
4479 if (mddev->degraded == 0)
4480 printk("raid5: raid level %d set %s active with %d out of %d"
4481 " devices, algorithm %d\n", conf->level, mdname(mddev),
4482 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4485 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4486 " out of %d devices, algorithm %d\n", conf->level,
4487 mdname(mddev), mddev->raid_disks - mddev->degraded,
4488 mddev->raid_disks, mddev->new_layout);
4490 print_raid5_conf(conf);
4492 if (conf->reshape_progress != MaxSector) {
4493 printk("...ok start reshape thread\n");
4494 conf->reshape_safe = conf->reshape_progress;
4495 atomic_set(&conf->reshape_stripes, 0);
4496 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4497 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4498 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4499 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4500 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4504 /* read-ahead size must cover two whole stripes, which is
4505 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4508 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4509 int stripe = data_disks *
4510 (mddev->chunk_size / PAGE_SIZE);
4511 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4512 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4515 /* Ok, everything is just fine now */
4516 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4518 "raid5: failed to create sysfs attributes for %s\n",
4521 mddev->queue->queue_lock = &conf->device_lock;
4523 mddev->queue->unplug_fn = raid5_unplug_device;
4524 mddev->queue->backing_dev_info.congested_data = mddev;
4525 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
4527 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
4529 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
4533 md_unregister_thread(mddev->thread);
4534 mddev->thread = NULL;
4536 shrink_stripes(conf);
4537 print_raid5_conf(conf);
4538 safe_put_page(conf->spare_page);
4540 kfree(conf->stripe_hashtbl);
4543 mddev->private = NULL;
4544 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4550 static int stop(mddev_t *mddev)
4552 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4554 md_unregister_thread(mddev->thread);
4555 mddev->thread = NULL;
4556 shrink_stripes(conf);
4557 kfree(conf->stripe_hashtbl);
4558 mddev->queue->backing_dev_info.congested_fn = NULL;
4559 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
4560 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
4563 mddev->private = NULL;
4568 static void print_sh(struct seq_file *seq, struct stripe_head *sh)
4572 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4573 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4574 seq_printf(seq, "sh %llu, count %d.\n",
4575 (unsigned long long)sh->sector, atomic_read(&sh->count));
4576 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
4577 for (i = 0; i < sh->disks; i++) {
4578 seq_printf(seq, "(cache%d: %p %ld) ",
4579 i, sh->dev[i].page, sh->dev[i].flags);
4581 seq_printf(seq, "\n");
4584 static void printall(struct seq_file *seq, raid5_conf_t *conf)
4586 struct stripe_head *sh;
4587 struct hlist_node *hn;
4590 spin_lock_irq(&conf->device_lock);
4591 for (i = 0; i < NR_HASH; i++) {
4592 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
4593 if (sh->raid_conf != conf)
4598 spin_unlock_irq(&conf->device_lock);
4602 static void status(struct seq_file *seq, mddev_t *mddev)
4604 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4607 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
4608 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
4609 for (i = 0; i < conf->raid_disks; i++)
4610 seq_printf (seq, "%s",
4611 conf->disks[i].rdev &&
4612 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
4613 seq_printf (seq, "]");
4615 seq_printf (seq, "\n");
4616 printall(seq, conf);
4620 static void print_raid5_conf (raid5_conf_t *conf)
4623 struct disk_info *tmp;
4625 printk("RAID5 conf printout:\n");
4627 printk("(conf==NULL)\n");
4630 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4631 conf->raid_disks - conf->mddev->degraded);
4633 for (i = 0; i < conf->raid_disks; i++) {
4634 char b[BDEVNAME_SIZE];
4635 tmp = conf->disks + i;
4637 printk(" disk %d, o:%d, dev:%s\n",
4638 i, !test_bit(Faulty, &tmp->rdev->flags),
4639 bdevname(tmp->rdev->bdev,b));
4643 static int raid5_spare_active(mddev_t *mddev)
4646 raid5_conf_t *conf = mddev->private;
4647 struct disk_info *tmp;
4649 for (i = 0; i < conf->raid_disks; i++) {
4650 tmp = conf->disks + i;
4652 && !test_bit(Faulty, &tmp->rdev->flags)
4653 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4654 unsigned long flags;
4655 spin_lock_irqsave(&conf->device_lock, flags);
4657 spin_unlock_irqrestore(&conf->device_lock, flags);
4660 print_raid5_conf(conf);
4664 static int raid5_remove_disk(mddev_t *mddev, int number)
4666 raid5_conf_t *conf = mddev->private;
4669 struct disk_info *p = conf->disks + number;
4671 print_raid5_conf(conf);
4674 if (number >= conf->raid_disks &&
4675 conf->reshape_progress == MaxSector)
4676 clear_bit(In_sync, &rdev->flags);
4678 if (test_bit(In_sync, &rdev->flags) ||
4679 atomic_read(&rdev->nr_pending)) {
4683 /* Only remove non-faulty devices if recovery
4686 if (!test_bit(Faulty, &rdev->flags) &&
4687 mddev->degraded <= conf->max_degraded &&
4688 number < conf->raid_disks) {
4694 if (atomic_read(&rdev->nr_pending)) {
4695 /* lost the race, try later */
4702 print_raid5_conf(conf);
4706 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4708 raid5_conf_t *conf = mddev->private;
4711 struct disk_info *p;
4713 int last = conf->raid_disks - 1;
4715 if (mddev->degraded > conf->max_degraded)
4716 /* no point adding a device */
4719 if (rdev->raid_disk >= 0)
4720 first = last = rdev->raid_disk;
4723 * find the disk ... but prefer rdev->saved_raid_disk
4726 if (rdev->saved_raid_disk >= 0 &&
4727 rdev->saved_raid_disk >= first &&
4728 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4729 disk = rdev->saved_raid_disk;
4732 for ( ; disk <= last ; disk++)
4733 if ((p=conf->disks + disk)->rdev == NULL) {
4734 clear_bit(In_sync, &rdev->flags);
4735 rdev->raid_disk = disk;
4737 if (rdev->saved_raid_disk != disk)
4739 rcu_assign_pointer(p->rdev, rdev);
4742 print_raid5_conf(conf);
4746 static int raid5_resize(mddev_t *mddev, sector_t sectors)
4748 /* no resync is happening, and there is enough space
4749 * on all devices, so we can resize.
4750 * We need to make sure resync covers any new space.
4751 * If the array is shrinking we should possibly wait until
4752 * any io in the removed space completes, but it hardly seems
4755 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
4756 md_set_array_sectors(mddev, raid5_size(mddev, sectors,
4757 mddev->raid_disks));
4758 if (mddev->array_sectors >
4759 raid5_size(mddev, sectors, mddev->raid_disks))
4761 set_capacity(mddev->gendisk, mddev->array_sectors);
4763 if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
4764 mddev->recovery_cp = mddev->dev_sectors;
4765 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4767 mddev->dev_sectors = sectors;
4768 mddev->resync_max_sectors = sectors;
4772 #ifdef CONFIG_MD_RAID5_RESHAPE
4773 static int raid5_check_reshape(mddev_t *mddev)
4775 raid5_conf_t *conf = mddev_to_conf(mddev);
4777 if (mddev->delta_disks == 0)
4778 return 0; /* nothing to do */
4780 /* Cannot grow a bitmap yet */
4782 if (mddev->degraded > conf->max_degraded)
4784 if (mddev->delta_disks < 0) {
4785 /* We might be able to shrink, but the devices must
4786 * be made bigger first.
4787 * For raid6, 4 is the minimum size.
4788 * Otherwise 2 is the minimum
4791 if (mddev->level == 6)
4793 if (mddev->raid_disks + mddev->delta_disks < min)
4797 /* Can only proceed if there are plenty of stripe_heads.
4798 * We need a minimum of one full stripe,, and for sensible progress
4799 * it is best to have about 4 times that.
4800 * If we require 4 times, then the default 256 4K stripe_heads will
4801 * allow for chunk sizes up to 256K, which is probably OK.
4802 * If the chunk size is greater, user-space should request more
4803 * stripe_heads first.
4805 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
4806 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
4807 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
4808 (max(mddev->chunk_size, mddev->new_chunk)
4813 return resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
4816 static int raid5_start_reshape(mddev_t *mddev)
4818 raid5_conf_t *conf = mddev_to_conf(mddev);
4821 int added_devices = 0;
4822 unsigned long flags;
4824 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4827 list_for_each_entry(rdev, &mddev->disks, same_set)
4828 if (rdev->raid_disk < 0 &&
4829 !test_bit(Faulty, &rdev->flags))
4832 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
4833 /* Not enough devices even to make a degraded array
4838 /* Refuse to reduce size of the array. Any reductions in
4839 * array size must be through explicit setting of array_size
4842 if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
4843 < mddev->array_sectors) {
4844 printk(KERN_ERR "md: %s: array size must be reduced "
4845 "before number of disks\n", mdname(mddev));
4849 atomic_set(&conf->reshape_stripes, 0);
4850 spin_lock_irq(&conf->device_lock);
4851 conf->previous_raid_disks = conf->raid_disks;
4852 conf->raid_disks += mddev->delta_disks;
4853 if (mddev->delta_disks < 0)
4854 conf->reshape_progress = raid5_size(mddev, 0, 0);
4856 conf->reshape_progress = 0;
4857 conf->reshape_safe = conf->reshape_progress;
4859 spin_unlock_irq(&conf->device_lock);
4861 /* Add some new drives, as many as will fit.
4862 * We know there are enough to make the newly sized array work.
4864 list_for_each_entry(rdev, &mddev->disks, same_set)
4865 if (rdev->raid_disk < 0 &&
4866 !test_bit(Faulty, &rdev->flags)) {
4867 if (raid5_add_disk(mddev, rdev) == 0) {
4869 set_bit(In_sync, &rdev->flags);
4871 rdev->recovery_offset = 0;
4872 sprintf(nm, "rd%d", rdev->raid_disk);
4873 if (sysfs_create_link(&mddev->kobj,
4876 "raid5: failed to create "
4877 " link %s for %s\n",
4883 if (mddev->delta_disks > 0) {
4884 spin_lock_irqsave(&conf->device_lock, flags);
4885 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks)
4887 spin_unlock_irqrestore(&conf->device_lock, flags);
4889 mddev->raid_disks = conf->raid_disks;
4890 mddev->reshape_position = 0;
4891 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4893 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4894 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4895 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4896 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4897 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4899 if (!mddev->sync_thread) {
4900 mddev->recovery = 0;
4901 spin_lock_irq(&conf->device_lock);
4902 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
4903 conf->reshape_progress = MaxSector;
4904 spin_unlock_irq(&conf->device_lock);
4907 md_wakeup_thread(mddev->sync_thread);
4908 md_new_event(mddev);
4913 /* This is called from the reshape thread and should make any
4914 * changes needed in 'conf'
4916 static void end_reshape(raid5_conf_t *conf)
4919 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
4921 spin_lock_irq(&conf->device_lock);
4922 conf->previous_raid_disks = conf->raid_disks;
4923 conf->reshape_progress = MaxSector;
4924 spin_unlock_irq(&conf->device_lock);
4926 /* read-ahead size must cover two whole stripes, which is
4927 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4930 int data_disks = conf->raid_disks - conf->max_degraded;
4931 int stripe = data_disks * (conf->chunk_size
4933 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4934 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4939 /* This is called from the raid5d thread with mddev_lock held.
4940 * It makes config changes to the device.
4942 static void raid5_finish_reshape(mddev_t *mddev)
4944 struct block_device *bdev;
4946 if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4948 if (mddev->delta_disks > 0) {
4949 md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
4950 set_capacity(mddev->gendisk, mddev->array_sectors);
4953 bdev = bdget_disk(mddev->gendisk, 0);
4955 mutex_lock(&bdev->bd_inode->i_mutex);
4956 i_size_write(bdev->bd_inode,
4957 (loff_t)mddev->array_sectors << 9);
4958 mutex_unlock(&bdev->bd_inode->i_mutex);
4963 raid5_conf_t *conf = mddev_to_conf(mddev);
4964 mddev->degraded = conf->raid_disks;
4965 for (d = 0; d < conf->raid_disks ; d++)
4966 if (conf->disks[d].rdev &&
4968 &conf->disks[d].rdev->flags))
4970 for (d = conf->raid_disks ;
4971 d < conf->raid_disks - mddev->delta_disks;
4973 raid5_remove_disk(mddev, d);
4975 mddev->reshape_position = MaxSector;
4976 mddev->delta_disks = 0;
4980 static void raid5_quiesce(mddev_t *mddev, int state)
4982 raid5_conf_t *conf = mddev_to_conf(mddev);
4985 case 2: /* resume for a suspend */
4986 wake_up(&conf->wait_for_overlap);
4989 case 1: /* stop all writes */
4990 spin_lock_irq(&conf->device_lock);
4992 wait_event_lock_irq(conf->wait_for_stripe,
4993 atomic_read(&conf->active_stripes) == 0 &&
4994 atomic_read(&conf->active_aligned_reads) == 0,
4995 conf->device_lock, /* nothing */);
4996 spin_unlock_irq(&conf->device_lock);
4999 case 0: /* re-enable writes */
5000 spin_lock_irq(&conf->device_lock);
5002 wake_up(&conf->wait_for_stripe);
5003 wake_up(&conf->wait_for_overlap);
5004 spin_unlock_irq(&conf->device_lock);
5010 static void *raid5_takeover_raid1(mddev_t *mddev)
5014 if (mddev->raid_disks != 2 ||
5015 mddev->degraded > 1)
5016 return ERR_PTR(-EINVAL);
5018 /* Should check if there are write-behind devices? */
5020 chunksect = 64*2; /* 64K by default */
5022 /* The array must be an exact multiple of chunksize */
5023 while (chunksect && (mddev->array_sectors & (chunksect-1)))
5026 if ((chunksect<<9) < STRIPE_SIZE)
5027 /* array size does not allow a suitable chunk size */
5028 return ERR_PTR(-EINVAL);
5030 mddev->new_level = 5;
5031 mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
5032 mddev->new_chunk = chunksect << 9;
5034 return setup_conf(mddev);
5037 static void *raid5_takeover_raid6(mddev_t *mddev)
5041 switch (mddev->layout) {
5042 case ALGORITHM_LEFT_ASYMMETRIC_6:
5043 new_layout = ALGORITHM_LEFT_ASYMMETRIC;
5045 case ALGORITHM_RIGHT_ASYMMETRIC_6:
5046 new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
5048 case ALGORITHM_LEFT_SYMMETRIC_6:
5049 new_layout = ALGORITHM_LEFT_SYMMETRIC;
5051 case ALGORITHM_RIGHT_SYMMETRIC_6:
5052 new_layout = ALGORITHM_RIGHT_SYMMETRIC;
5054 case ALGORITHM_PARITY_0_6:
5055 new_layout = ALGORITHM_PARITY_0;
5057 case ALGORITHM_PARITY_N:
5058 new_layout = ALGORITHM_PARITY_N;
5061 return ERR_PTR(-EINVAL);
5063 mddev->new_level = 5;
5064 mddev->new_layout = new_layout;
5065 mddev->delta_disks = -1;
5066 mddev->raid_disks -= 1;
5067 return setup_conf(mddev);
5071 static int raid5_reconfig(mddev_t *mddev, int new_layout, int new_chunk)
5073 /* Currently the layout and chunk size can only be changed
5074 * for a 2-drive raid array, as in that case no data shuffling
5076 * Later we might validate these and set new_* so a reshape
5077 * can complete the change.
5079 raid5_conf_t *conf = mddev_to_conf(mddev);
5081 if (new_layout >= 0 && !algorithm_valid_raid5(new_layout))
5083 if (new_chunk > 0) {
5084 if (new_chunk & (new_chunk-1))
5085 /* not a power of 2 */
5087 if (new_chunk < PAGE_SIZE)
5089 if (mddev->array_sectors & ((new_chunk>>9)-1))
5090 /* not factor of array size */
5094 /* They look valid */
5096 if (mddev->raid_disks != 2)
5099 if (new_layout >= 0) {
5100 conf->algorithm = new_layout;
5101 mddev->layout = mddev->new_layout = new_layout;
5103 if (new_chunk > 0) {
5104 conf->chunk_size = new_chunk;
5105 mddev->chunk_size = mddev->new_chunk = new_chunk;
5107 set_bit(MD_CHANGE_DEVS, &mddev->flags);
5108 md_wakeup_thread(mddev->thread);
5112 static void *raid5_takeover(mddev_t *mddev)
5114 /* raid5 can take over:
5115 * raid0 - if all devices are the same - make it a raid4 layout
5116 * raid1 - if there are two drives. We need to know the chunk size
5117 * raid4 - trivial - just use a raid4 layout.
5118 * raid6 - Providing it is a *_6 layout
5120 * For now, just do raid1
5123 if (mddev->level == 1)
5124 return raid5_takeover_raid1(mddev);
5125 if (mddev->level == 4) {
5126 mddev->new_layout = ALGORITHM_PARITY_N;
5127 mddev->new_level = 5;
5128 return setup_conf(mddev);
5130 if (mddev->level == 6)
5131 return raid5_takeover_raid6(mddev);
5133 return ERR_PTR(-EINVAL);
5137 static struct mdk_personality raid5_personality;
5139 static void *raid6_takeover(mddev_t *mddev)
5141 /* Currently can only take over a raid5. We map the
5142 * personality to an equivalent raid6 personality
5143 * with the Q block at the end.
5147 if (mddev->pers != &raid5_personality)
5148 return ERR_PTR(-EINVAL);
5149 if (mddev->degraded > 1)
5150 return ERR_PTR(-EINVAL);
5151 if (mddev->raid_disks > 253)
5152 return ERR_PTR(-EINVAL);
5153 if (mddev->raid_disks < 3)
5154 return ERR_PTR(-EINVAL);
5156 switch (mddev->layout) {
5157 case ALGORITHM_LEFT_ASYMMETRIC:
5158 new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
5160 case ALGORITHM_RIGHT_ASYMMETRIC:
5161 new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
5163 case ALGORITHM_LEFT_SYMMETRIC:
5164 new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
5166 case ALGORITHM_RIGHT_SYMMETRIC:
5167 new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
5169 case ALGORITHM_PARITY_0:
5170 new_layout = ALGORITHM_PARITY_0_6;
5172 case ALGORITHM_PARITY_N:
5173 new_layout = ALGORITHM_PARITY_N;
5176 return ERR_PTR(-EINVAL);
5178 mddev->new_level = 6;
5179 mddev->new_layout = new_layout;
5180 mddev->delta_disks = 1;
5181 mddev->raid_disks += 1;
5182 return setup_conf(mddev);
5186 static struct mdk_personality raid6_personality =
5190 .owner = THIS_MODULE,
5191 .make_request = make_request,
5195 .error_handler = error,
5196 .hot_add_disk = raid5_add_disk,
5197 .hot_remove_disk= raid5_remove_disk,
5198 .spare_active = raid5_spare_active,
5199 .sync_request = sync_request,
5200 .resize = raid5_resize,
5202 #ifdef CONFIG_MD_RAID5_RESHAPE
5203 .check_reshape = raid5_check_reshape,
5204 .start_reshape = raid5_start_reshape,
5205 .finish_reshape = raid5_finish_reshape,
5207 .quiesce = raid5_quiesce,
5208 .takeover = raid6_takeover,
5210 static struct mdk_personality raid5_personality =
5214 .owner = THIS_MODULE,
5215 .make_request = make_request,
5219 .error_handler = error,
5220 .hot_add_disk = raid5_add_disk,
5221 .hot_remove_disk= raid5_remove_disk,
5222 .spare_active = raid5_spare_active,
5223 .sync_request = sync_request,
5224 .resize = raid5_resize,
5226 #ifdef CONFIG_MD_RAID5_RESHAPE
5227 .check_reshape = raid5_check_reshape,
5228 .start_reshape = raid5_start_reshape,
5229 .finish_reshape = raid5_finish_reshape,
5231 .quiesce = raid5_quiesce,
5232 .takeover = raid5_takeover,
5233 .reconfig = raid5_reconfig,
5236 static struct mdk_personality raid4_personality =
5240 .owner = THIS_MODULE,
5241 .make_request = make_request,
5245 .error_handler = error,
5246 .hot_add_disk = raid5_add_disk,
5247 .hot_remove_disk= raid5_remove_disk,
5248 .spare_active = raid5_spare_active,
5249 .sync_request = sync_request,
5250 .resize = raid5_resize,
5252 #ifdef CONFIG_MD_RAID5_RESHAPE
5253 .check_reshape = raid5_check_reshape,
5254 .start_reshape = raid5_start_reshape,
5255 .finish_reshape = raid5_finish_reshape,
5257 .quiesce = raid5_quiesce,
5260 static int __init raid5_init(void)
5262 register_md_personality(&raid6_personality);
5263 register_md_personality(&raid5_personality);
5264 register_md_personality(&raid4_personality);
5268 static void raid5_exit(void)
5270 unregister_md_personality(&raid6_personality);
5271 unregister_md_personality(&raid5_personality);
5272 unregister_md_personality(&raid4_personality);
5275 module_init(raid5_init);
5276 module_exit(raid5_exit);
5277 MODULE_LICENSE("GPL");
5278 MODULE_ALIAS("md-personality-4"); /* RAID5 */
5279 MODULE_ALIAS("md-raid5");
5280 MODULE_ALIAS("md-raid4");
5281 MODULE_ALIAS("md-level-5");
5282 MODULE_ALIAS("md-level-4");
5283 MODULE_ALIAS("md-personality-8"); /* RAID6 */
5284 MODULE_ALIAS("md-raid6");
5285 MODULE_ALIAS("md-level-6");
5287 /* This used to be two separate modules, they were: */
5288 MODULE_ALIAS("raid5");
5289 MODULE_ALIAS("raid6");