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/module.h>
47 #include <linux/slab.h>
48 #include <linux/highmem.h>
49 #include <linux/bitops.h>
50 #include <linux/kthread.h>
51 #include <asm/atomic.h>
54 #include <linux/raid/bitmap.h>
55 #include <linux/async_tx.h>
61 #define NR_STRIPES 256
62 #define STRIPE_SIZE PAGE_SIZE
63 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
64 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
65 #define IO_THRESHOLD 1
66 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
67 #define HASH_MASK (NR_HASH - 1)
69 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
71 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
72 * order without overlap. There may be several bio's per stripe+device, and
73 * a bio could span several devices.
74 * When walking this list for a particular stripe+device, we must never proceed
75 * beyond a bio that extends past this device, as the next bio might no longer
77 * This macro is used to determine the 'next' bio in the list, given the sector
78 * of the current stripe+device
80 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
82 * The following can be used to debug the driver
84 #define RAID5_PARANOIA 1
85 #if RAID5_PARANOIA && defined(CONFIG_SMP)
86 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
88 # define CHECK_DEVLOCK()
96 #if !RAID6_USE_EMPTY_ZERO_PAGE
97 /* In .bss so it's zeroed */
98 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
101 static inline int raid6_next_disk(int disk, int raid_disks)
104 return (disk < raid_disks) ? disk : 0;
107 static void return_io(struct bio *return_bi)
109 struct bio *bi = return_bi;
111 int bytes = bi->bi_size;
113 return_bi = bi->bi_next;
116 bi->bi_end_io(bi, bytes,
117 test_bit(BIO_UPTODATE, &bi->bi_flags)
123 static void print_raid5_conf (raid5_conf_t *conf);
125 static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
127 if (atomic_dec_and_test(&sh->count)) {
128 BUG_ON(!list_empty(&sh->lru));
129 BUG_ON(atomic_read(&conf->active_stripes)==0);
130 if (test_bit(STRIPE_HANDLE, &sh->state)) {
131 if (test_bit(STRIPE_DELAYED, &sh->state)) {
132 list_add_tail(&sh->lru, &conf->delayed_list);
133 blk_plug_device(conf->mddev->queue);
134 } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
135 sh->bm_seq - conf->seq_write > 0) {
136 list_add_tail(&sh->lru, &conf->bitmap_list);
137 blk_plug_device(conf->mddev->queue);
139 clear_bit(STRIPE_BIT_DELAY, &sh->state);
140 list_add_tail(&sh->lru, &conf->handle_list);
142 md_wakeup_thread(conf->mddev->thread);
144 BUG_ON(sh->ops.pending);
145 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
146 atomic_dec(&conf->preread_active_stripes);
147 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
148 md_wakeup_thread(conf->mddev->thread);
150 atomic_dec(&conf->active_stripes);
151 if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
152 list_add_tail(&sh->lru, &conf->inactive_list);
153 wake_up(&conf->wait_for_stripe);
154 if (conf->retry_read_aligned)
155 md_wakeup_thread(conf->mddev->thread);
160 static void release_stripe(struct stripe_head *sh)
162 raid5_conf_t *conf = sh->raid_conf;
165 spin_lock_irqsave(&conf->device_lock, flags);
166 __release_stripe(conf, sh);
167 spin_unlock_irqrestore(&conf->device_lock, flags);
170 static inline void remove_hash(struct stripe_head *sh)
172 pr_debug("remove_hash(), stripe %llu\n",
173 (unsigned long long)sh->sector);
175 hlist_del_init(&sh->hash);
178 static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
180 struct hlist_head *hp = stripe_hash(conf, sh->sector);
182 pr_debug("insert_hash(), stripe %llu\n",
183 (unsigned long long)sh->sector);
186 hlist_add_head(&sh->hash, hp);
190 /* find an idle stripe, make sure it is unhashed, and return it. */
191 static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
193 struct stripe_head *sh = NULL;
194 struct list_head *first;
197 if (list_empty(&conf->inactive_list))
199 first = conf->inactive_list.next;
200 sh = list_entry(first, struct stripe_head, lru);
201 list_del_init(first);
203 atomic_inc(&conf->active_stripes);
208 static void shrink_buffers(struct stripe_head *sh, int num)
213 for (i=0; i<num ; i++) {
217 sh->dev[i].page = NULL;
222 static int grow_buffers(struct stripe_head *sh, int num)
226 for (i=0; i<num; i++) {
229 if (!(page = alloc_page(GFP_KERNEL))) {
232 sh->dev[i].page = page;
237 static void raid5_build_block (struct stripe_head *sh, int i);
239 static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
241 raid5_conf_t *conf = sh->raid_conf;
244 BUG_ON(atomic_read(&sh->count) != 0);
245 BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
246 BUG_ON(sh->ops.pending || sh->ops.ack || sh->ops.complete);
249 pr_debug("init_stripe called, stripe %llu\n",
250 (unsigned long long)sh->sector);
260 for (i = sh->disks; i--; ) {
261 struct r5dev *dev = &sh->dev[i];
263 if (dev->toread || dev->read || dev->towrite || dev->written ||
264 test_bit(R5_LOCKED, &dev->flags)) {
265 printk(KERN_ERR "sector=%llx i=%d %p %p %p %p %d\n",
266 (unsigned long long)sh->sector, i, dev->toread,
267 dev->read, dev->towrite, dev->written,
268 test_bit(R5_LOCKED, &dev->flags));
272 raid5_build_block(sh, i);
274 insert_hash(conf, sh);
277 static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
279 struct stripe_head *sh;
280 struct hlist_node *hn;
283 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
284 hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
285 if (sh->sector == sector && sh->disks == disks)
287 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
291 static void unplug_slaves(mddev_t *mddev);
292 static void raid5_unplug_device(request_queue_t *q);
294 static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
295 int pd_idx, int noblock)
297 struct stripe_head *sh;
299 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
301 spin_lock_irq(&conf->device_lock);
304 wait_event_lock_irq(conf->wait_for_stripe,
306 conf->device_lock, /* nothing */);
307 sh = __find_stripe(conf, sector, disks);
309 if (!conf->inactive_blocked)
310 sh = get_free_stripe(conf);
311 if (noblock && sh == NULL)
314 conf->inactive_blocked = 1;
315 wait_event_lock_irq(conf->wait_for_stripe,
316 !list_empty(&conf->inactive_list) &&
317 (atomic_read(&conf->active_stripes)
318 < (conf->max_nr_stripes *3/4)
319 || !conf->inactive_blocked),
321 raid5_unplug_device(conf->mddev->queue)
323 conf->inactive_blocked = 0;
325 init_stripe(sh, sector, pd_idx, disks);
327 if (atomic_read(&sh->count)) {
328 BUG_ON(!list_empty(&sh->lru));
330 if (!test_bit(STRIPE_HANDLE, &sh->state))
331 atomic_inc(&conf->active_stripes);
332 if (list_empty(&sh->lru) &&
333 !test_bit(STRIPE_EXPANDING, &sh->state))
335 list_del_init(&sh->lru);
338 } while (sh == NULL);
341 atomic_inc(&sh->count);
343 spin_unlock_irq(&conf->device_lock);
347 /* test_and_ack_op() ensures that we only dequeue an operation once */
348 #define test_and_ack_op(op, pend) \
350 if (test_bit(op, &sh->ops.pending) && \
351 !test_bit(op, &sh->ops.complete)) { \
352 if (test_and_set_bit(op, &sh->ops.ack)) \
353 clear_bit(op, &pend); \
357 clear_bit(op, &pend); \
360 /* find new work to run, do not resubmit work that is already
363 static unsigned long get_stripe_work(struct stripe_head *sh)
365 unsigned long pending;
368 pending = sh->ops.pending;
370 test_and_ack_op(STRIPE_OP_BIOFILL, pending);
371 test_and_ack_op(STRIPE_OP_COMPUTE_BLK, pending);
372 test_and_ack_op(STRIPE_OP_PREXOR, pending);
373 test_and_ack_op(STRIPE_OP_BIODRAIN, pending);
374 test_and_ack_op(STRIPE_OP_POSTXOR, pending);
375 test_and_ack_op(STRIPE_OP_CHECK, pending);
376 if (test_and_clear_bit(STRIPE_OP_IO, &sh->ops.pending))
379 sh->ops.count -= ack;
380 BUG_ON(sh->ops.count < 0);
386 raid5_end_read_request(struct bio *bi, unsigned int bytes_done, int error);
388 raid5_end_write_request (struct bio *bi, unsigned int bytes_done, int error);
390 static void ops_run_io(struct stripe_head *sh)
392 raid5_conf_t *conf = sh->raid_conf;
393 int i, disks = sh->disks;
397 for (i = disks; i--; ) {
401 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
403 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
408 bi = &sh->dev[i].req;
412 bi->bi_end_io = raid5_end_write_request;
414 bi->bi_end_io = raid5_end_read_request;
417 rdev = rcu_dereference(conf->disks[i].rdev);
418 if (rdev && test_bit(Faulty, &rdev->flags))
421 atomic_inc(&rdev->nr_pending);
425 if (test_bit(STRIPE_SYNCING, &sh->state) ||
426 test_bit(STRIPE_EXPAND_SOURCE, &sh->state) ||
427 test_bit(STRIPE_EXPAND_READY, &sh->state))
428 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
430 bi->bi_bdev = rdev->bdev;
431 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
432 __FUNCTION__, (unsigned long long)sh->sector,
434 atomic_inc(&sh->count);
435 bi->bi_sector = sh->sector + rdev->data_offset;
436 bi->bi_flags = 1 << BIO_UPTODATE;
440 bi->bi_io_vec = &sh->dev[i].vec;
441 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
442 bi->bi_io_vec[0].bv_offset = 0;
443 bi->bi_size = STRIPE_SIZE;
446 test_bit(R5_ReWrite, &sh->dev[i].flags))
447 atomic_add(STRIPE_SECTORS,
448 &rdev->corrected_errors);
449 generic_make_request(bi);
452 set_bit(STRIPE_DEGRADED, &sh->state);
453 pr_debug("skip op %ld on disc %d for sector %llu\n",
454 bi->bi_rw, i, (unsigned long long)sh->sector);
455 clear_bit(R5_LOCKED, &sh->dev[i].flags);
456 set_bit(STRIPE_HANDLE, &sh->state);
461 static struct dma_async_tx_descriptor *
462 async_copy_data(int frombio, struct bio *bio, struct page *page,
463 sector_t sector, struct dma_async_tx_descriptor *tx)
466 struct page *bio_page;
470 if (bio->bi_sector >= sector)
471 page_offset = (signed)(bio->bi_sector - sector) * 512;
473 page_offset = (signed)(sector - bio->bi_sector) * -512;
474 bio_for_each_segment(bvl, bio, i) {
475 int len = bio_iovec_idx(bio, i)->bv_len;
479 if (page_offset < 0) {
480 b_offset = -page_offset;
481 page_offset += b_offset;
485 if (len > 0 && page_offset + len > STRIPE_SIZE)
486 clen = STRIPE_SIZE - page_offset;
491 b_offset += bio_iovec_idx(bio, i)->bv_offset;
492 bio_page = bio_iovec_idx(bio, i)->bv_page;
494 tx = async_memcpy(page, bio_page, page_offset,
496 ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_SRC,
499 tx = async_memcpy(bio_page, page, b_offset,
501 ASYNC_TX_DEP_ACK | ASYNC_TX_KMAP_DST,
504 if (clen < len) /* hit end of page */
512 static void ops_complete_biofill(void *stripe_head_ref)
514 struct stripe_head *sh = stripe_head_ref;
515 struct bio *return_bi = NULL;
516 raid5_conf_t *conf = sh->raid_conf;
517 int i, more_to_read = 0;
519 pr_debug("%s: stripe %llu\n", __FUNCTION__,
520 (unsigned long long)sh->sector);
522 /* clear completed biofills */
523 for (i = sh->disks; i--; ) {
524 struct r5dev *dev = &sh->dev[i];
525 /* check if this stripe has new incoming reads */
529 /* acknowledge completion of a biofill operation */
530 /* and check if we need to reply to a read request
532 if (test_bit(R5_Wantfill, &dev->flags) && !dev->toread) {
533 struct bio *rbi, *rbi2;
534 clear_bit(R5_Wantfill, &dev->flags);
536 /* The access to dev->read is outside of the
537 * spin_lock_irq(&conf->device_lock), but is protected
538 * by the STRIPE_OP_BIOFILL pending bit
543 while (rbi && rbi->bi_sector <
544 dev->sector + STRIPE_SECTORS) {
545 rbi2 = r5_next_bio(rbi, dev->sector);
546 spin_lock_irq(&conf->device_lock);
547 if (--rbi->bi_phys_segments == 0) {
548 rbi->bi_next = return_bi;
551 spin_unlock_irq(&conf->device_lock);
556 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.ack);
557 clear_bit(STRIPE_OP_BIOFILL, &sh->ops.pending);
559 return_io(return_bi);
562 set_bit(STRIPE_HANDLE, &sh->state);
566 static void ops_run_biofill(struct stripe_head *sh)
568 struct dma_async_tx_descriptor *tx = NULL;
569 raid5_conf_t *conf = sh->raid_conf;
572 pr_debug("%s: stripe %llu\n", __FUNCTION__,
573 (unsigned long long)sh->sector);
575 for (i = sh->disks; i--; ) {
576 struct r5dev *dev = &sh->dev[i];
577 if (test_bit(R5_Wantfill, &dev->flags)) {
579 spin_lock_irq(&conf->device_lock);
580 dev->read = rbi = dev->toread;
582 spin_unlock_irq(&conf->device_lock);
583 while (rbi && rbi->bi_sector <
584 dev->sector + STRIPE_SECTORS) {
585 tx = async_copy_data(0, rbi, dev->page,
587 rbi = r5_next_bio(rbi, dev->sector);
592 atomic_inc(&sh->count);
593 async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
594 ops_complete_biofill, sh);
597 static void ops_complete_compute5(void *stripe_head_ref)
599 struct stripe_head *sh = stripe_head_ref;
600 int target = sh->ops.target;
601 struct r5dev *tgt = &sh->dev[target];
603 pr_debug("%s: stripe %llu\n", __FUNCTION__,
604 (unsigned long long)sh->sector);
606 set_bit(R5_UPTODATE, &tgt->flags);
607 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
608 clear_bit(R5_Wantcompute, &tgt->flags);
609 set_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
610 set_bit(STRIPE_HANDLE, &sh->state);
614 static struct dma_async_tx_descriptor *
615 ops_run_compute5(struct stripe_head *sh, unsigned long pending)
617 /* kernel stack size limits the total number of disks */
618 int disks = sh->disks;
619 struct page *xor_srcs[disks];
620 int target = sh->ops.target;
621 struct r5dev *tgt = &sh->dev[target];
622 struct page *xor_dest = tgt->page;
624 struct dma_async_tx_descriptor *tx;
627 pr_debug("%s: stripe %llu block: %d\n",
628 __FUNCTION__, (unsigned long long)sh->sector, target);
629 BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
631 for (i = disks; i--; )
633 xor_srcs[count++] = sh->dev[i].page;
635 atomic_inc(&sh->count);
637 if (unlikely(count == 1))
638 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
639 0, NULL, ops_complete_compute5, sh);
641 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
642 ASYNC_TX_XOR_ZERO_DST, NULL,
643 ops_complete_compute5, sh);
645 /* ack now if postxor is not set to be run */
646 if (tx && !test_bit(STRIPE_OP_POSTXOR, &pending))
652 static void ops_complete_prexor(void *stripe_head_ref)
654 struct stripe_head *sh = stripe_head_ref;
656 pr_debug("%s: stripe %llu\n", __FUNCTION__,
657 (unsigned long long)sh->sector);
659 set_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
662 static struct dma_async_tx_descriptor *
663 ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
665 /* kernel stack size limits the total number of disks */
666 int disks = sh->disks;
667 struct page *xor_srcs[disks];
668 int count = 0, pd_idx = sh->pd_idx, i;
670 /* existing parity data subtracted */
671 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
673 pr_debug("%s: stripe %llu\n", __FUNCTION__,
674 (unsigned long long)sh->sector);
676 for (i = disks; i--; ) {
677 struct r5dev *dev = &sh->dev[i];
678 /* Only process blocks that are known to be uptodate */
679 if (dev->towrite && test_bit(R5_Wantprexor, &dev->flags))
680 xor_srcs[count++] = dev->page;
683 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
684 ASYNC_TX_DEP_ACK | ASYNC_TX_XOR_DROP_DST, tx,
685 ops_complete_prexor, sh);
690 static struct dma_async_tx_descriptor *
691 ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
693 int disks = sh->disks;
694 int pd_idx = sh->pd_idx, i;
696 /* check if prexor is active which means only process blocks
697 * that are part of a read-modify-write (Wantprexor)
699 int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
701 pr_debug("%s: stripe %llu\n", __FUNCTION__,
702 (unsigned long long)sh->sector);
704 for (i = disks; i--; ) {
705 struct r5dev *dev = &sh->dev[i];
710 if (prexor) { /* rmw */
712 test_bit(R5_Wantprexor, &dev->flags))
715 if (i != pd_idx && dev->towrite &&
716 test_bit(R5_LOCKED, &dev->flags))
723 spin_lock(&sh->lock);
724 chosen = dev->towrite;
726 BUG_ON(dev->written);
727 wbi = dev->written = chosen;
728 spin_unlock(&sh->lock);
730 while (wbi && wbi->bi_sector <
731 dev->sector + STRIPE_SECTORS) {
732 tx = async_copy_data(1, wbi, dev->page,
734 wbi = r5_next_bio(wbi, dev->sector);
742 static void ops_complete_postxor(void *stripe_head_ref)
744 struct stripe_head *sh = stripe_head_ref;
746 pr_debug("%s: stripe %llu\n", __FUNCTION__,
747 (unsigned long long)sh->sector);
749 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
750 set_bit(STRIPE_HANDLE, &sh->state);
754 static void ops_complete_write(void *stripe_head_ref)
756 struct stripe_head *sh = stripe_head_ref;
757 int disks = sh->disks, i, pd_idx = sh->pd_idx;
759 pr_debug("%s: stripe %llu\n", __FUNCTION__,
760 (unsigned long long)sh->sector);
762 for (i = disks; i--; ) {
763 struct r5dev *dev = &sh->dev[i];
764 if (dev->written || i == pd_idx)
765 set_bit(R5_UPTODATE, &dev->flags);
768 set_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
769 set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
771 set_bit(STRIPE_HANDLE, &sh->state);
776 ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
778 /* kernel stack size limits the total number of disks */
779 int disks = sh->disks;
780 struct page *xor_srcs[disks];
782 int count = 0, pd_idx = sh->pd_idx, i;
783 struct page *xor_dest;
784 int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
786 dma_async_tx_callback callback;
788 pr_debug("%s: stripe %llu\n", __FUNCTION__,
789 (unsigned long long)sh->sector);
791 /* check if prexor is active which means only process blocks
792 * that are part of a read-modify-write (written)
795 xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
796 for (i = disks; i--; ) {
797 struct r5dev *dev = &sh->dev[i];
799 xor_srcs[count++] = dev->page;
802 xor_dest = sh->dev[pd_idx].page;
803 for (i = disks; i--; ) {
804 struct r5dev *dev = &sh->dev[i];
806 xor_srcs[count++] = dev->page;
810 /* check whether this postxor is part of a write */
811 callback = test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending) ?
812 ops_complete_write : ops_complete_postxor;
814 /* 1/ if we prexor'd then the dest is reused as a source
815 * 2/ if we did not prexor then we are redoing the parity
816 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
817 * for the synchronous xor case
819 flags = ASYNC_TX_DEP_ACK | ASYNC_TX_ACK |
820 (prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
822 atomic_inc(&sh->count);
824 if (unlikely(count == 1)) {
825 flags &= ~(ASYNC_TX_XOR_DROP_DST | ASYNC_TX_XOR_ZERO_DST);
826 tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE,
827 flags, tx, callback, sh);
829 tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
830 flags, tx, callback, sh);
833 static void ops_complete_check(void *stripe_head_ref)
835 struct stripe_head *sh = stripe_head_ref;
836 int pd_idx = sh->pd_idx;
838 pr_debug("%s: stripe %llu\n", __FUNCTION__,
839 (unsigned long long)sh->sector);
841 if (test_and_clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending) &&
842 sh->ops.zero_sum_result == 0)
843 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
845 set_bit(STRIPE_OP_CHECK, &sh->ops.complete);
846 set_bit(STRIPE_HANDLE, &sh->state);
850 static void ops_run_check(struct stripe_head *sh)
852 /* kernel stack size limits the total number of disks */
853 int disks = sh->disks;
854 struct page *xor_srcs[disks];
855 struct dma_async_tx_descriptor *tx;
857 int count = 0, pd_idx = sh->pd_idx, i;
858 struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
860 pr_debug("%s: stripe %llu\n", __FUNCTION__,
861 (unsigned long long)sh->sector);
863 for (i = disks; i--; ) {
864 struct r5dev *dev = &sh->dev[i];
866 xor_srcs[count++] = dev->page;
869 tx = async_xor_zero_sum(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
870 &sh->ops.zero_sum_result, 0, NULL, NULL, NULL);
873 set_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
875 clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending);
877 atomic_inc(&sh->count);
878 tx = async_trigger_callback(ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, tx,
879 ops_complete_check, sh);
882 static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
884 int overlap_clear = 0, i, disks = sh->disks;
885 struct dma_async_tx_descriptor *tx = NULL;
887 if (test_bit(STRIPE_OP_BIOFILL, &pending)) {
892 if (test_bit(STRIPE_OP_COMPUTE_BLK, &pending))
893 tx = ops_run_compute5(sh, pending);
895 if (test_bit(STRIPE_OP_PREXOR, &pending))
896 tx = ops_run_prexor(sh, tx);
898 if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
899 tx = ops_run_biodrain(sh, tx);
903 if (test_bit(STRIPE_OP_POSTXOR, &pending))
904 ops_run_postxor(sh, tx);
906 if (test_bit(STRIPE_OP_CHECK, &pending))
909 if (test_bit(STRIPE_OP_IO, &pending))
913 for (i = disks; i--; ) {
914 struct r5dev *dev = &sh->dev[i];
915 if (test_and_clear_bit(R5_Overlap, &dev->flags))
916 wake_up(&sh->raid_conf->wait_for_overlap);
920 static int grow_one_stripe(raid5_conf_t *conf)
922 struct stripe_head *sh;
923 sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
926 memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
927 sh->raid_conf = conf;
928 spin_lock_init(&sh->lock);
930 if (grow_buffers(sh, conf->raid_disks)) {
931 shrink_buffers(sh, conf->raid_disks);
932 kmem_cache_free(conf->slab_cache, sh);
935 sh->disks = conf->raid_disks;
936 /* we just created an active stripe so... */
937 atomic_set(&sh->count, 1);
938 atomic_inc(&conf->active_stripes);
939 INIT_LIST_HEAD(&sh->lru);
944 static int grow_stripes(raid5_conf_t *conf, int num)
946 struct kmem_cache *sc;
947 int devs = conf->raid_disks;
949 sprintf(conf->cache_name[0], "raid5-%s", mdname(conf->mddev));
950 sprintf(conf->cache_name[1], "raid5-%s-alt", mdname(conf->mddev));
951 conf->active_name = 0;
952 sc = kmem_cache_create(conf->cache_name[conf->active_name],
953 sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
957 conf->slab_cache = sc;
958 conf->pool_size = devs;
960 if (!grow_one_stripe(conf))
965 #ifdef CONFIG_MD_RAID5_RESHAPE
966 static int resize_stripes(raid5_conf_t *conf, int newsize)
968 /* Make all the stripes able to hold 'newsize' devices.
969 * New slots in each stripe get 'page' set to a new page.
971 * This happens in stages:
972 * 1/ create a new kmem_cache and allocate the required number of
974 * 2/ gather all the old stripe_heads and tranfer the pages across
975 * to the new stripe_heads. This will have the side effect of
976 * freezing the array as once all stripe_heads have been collected,
977 * no IO will be possible. Old stripe heads are freed once their
978 * pages have been transferred over, and the old kmem_cache is
979 * freed when all stripes are done.
980 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
981 * we simple return a failre status - no need to clean anything up.
982 * 4/ allocate new pages for the new slots in the new stripe_heads.
983 * If this fails, we don't bother trying the shrink the
984 * stripe_heads down again, we just leave them as they are.
985 * As each stripe_head is processed the new one is released into
988 * Once step2 is started, we cannot afford to wait for a write,
989 * so we use GFP_NOIO allocations.
991 struct stripe_head *osh, *nsh;
992 LIST_HEAD(newstripes);
993 struct disk_info *ndisks;
995 struct kmem_cache *sc;
998 if (newsize <= conf->pool_size)
999 return 0; /* never bother to shrink */
1001 md_allow_write(conf->mddev);
1004 sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
1005 sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
1010 for (i = conf->max_nr_stripes; i; i--) {
1011 nsh = kmem_cache_alloc(sc, GFP_KERNEL);
1015 memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
1017 nsh->raid_conf = conf;
1018 spin_lock_init(&nsh->lock);
1020 list_add(&nsh->lru, &newstripes);
1023 /* didn't get enough, give up */
1024 while (!list_empty(&newstripes)) {
1025 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1026 list_del(&nsh->lru);
1027 kmem_cache_free(sc, nsh);
1029 kmem_cache_destroy(sc);
1032 /* Step 2 - Must use GFP_NOIO now.
1033 * OK, we have enough stripes, start collecting inactive
1034 * stripes and copying them over
1036 list_for_each_entry(nsh, &newstripes, lru) {
1037 spin_lock_irq(&conf->device_lock);
1038 wait_event_lock_irq(conf->wait_for_stripe,
1039 !list_empty(&conf->inactive_list),
1041 unplug_slaves(conf->mddev)
1043 osh = get_free_stripe(conf);
1044 spin_unlock_irq(&conf->device_lock);
1045 atomic_set(&nsh->count, 1);
1046 for(i=0; i<conf->pool_size; i++)
1047 nsh->dev[i].page = osh->dev[i].page;
1048 for( ; i<newsize; i++)
1049 nsh->dev[i].page = NULL;
1050 kmem_cache_free(conf->slab_cache, osh);
1052 kmem_cache_destroy(conf->slab_cache);
1055 * At this point, we are holding all the stripes so the array
1056 * is completely stalled, so now is a good time to resize
1059 ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
1061 for (i=0; i<conf->raid_disks; i++)
1062 ndisks[i] = conf->disks[i];
1064 conf->disks = ndisks;
1068 /* Step 4, return new stripes to service */
1069 while(!list_empty(&newstripes)) {
1070 nsh = list_entry(newstripes.next, struct stripe_head, lru);
1071 list_del_init(&nsh->lru);
1072 for (i=conf->raid_disks; i < newsize; i++)
1073 if (nsh->dev[i].page == NULL) {
1074 struct page *p = alloc_page(GFP_NOIO);
1075 nsh->dev[i].page = p;
1079 release_stripe(nsh);
1081 /* critical section pass, GFP_NOIO no longer needed */
1083 conf->slab_cache = sc;
1084 conf->active_name = 1-conf->active_name;
1085 conf->pool_size = newsize;
1090 static int drop_one_stripe(raid5_conf_t *conf)
1092 struct stripe_head *sh;
1094 spin_lock_irq(&conf->device_lock);
1095 sh = get_free_stripe(conf);
1096 spin_unlock_irq(&conf->device_lock);
1099 BUG_ON(atomic_read(&sh->count));
1100 shrink_buffers(sh, conf->pool_size);
1101 kmem_cache_free(conf->slab_cache, sh);
1102 atomic_dec(&conf->active_stripes);
1106 static void shrink_stripes(raid5_conf_t *conf)
1108 while (drop_one_stripe(conf))
1111 if (conf->slab_cache)
1112 kmem_cache_destroy(conf->slab_cache);
1113 conf->slab_cache = NULL;
1116 static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
1119 struct stripe_head *sh = bi->bi_private;
1120 raid5_conf_t *conf = sh->raid_conf;
1121 int disks = sh->disks, i;
1122 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1123 char b[BDEVNAME_SIZE];
1129 for (i=0 ; i<disks; i++)
1130 if (bi == &sh->dev[i].req)
1133 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1134 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1142 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1143 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1144 rdev = conf->disks[i].rdev;
1145 printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
1146 mdname(conf->mddev), STRIPE_SECTORS,
1147 (unsigned long long)sh->sector + rdev->data_offset,
1148 bdevname(rdev->bdev, b));
1149 clear_bit(R5_ReadError, &sh->dev[i].flags);
1150 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1152 if (atomic_read(&conf->disks[i].rdev->read_errors))
1153 atomic_set(&conf->disks[i].rdev->read_errors, 0);
1155 const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
1157 rdev = conf->disks[i].rdev;
1159 clear_bit(R5_UPTODATE, &sh->dev[i].flags);
1160 atomic_inc(&rdev->read_errors);
1161 if (conf->mddev->degraded)
1162 printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n",
1163 mdname(conf->mddev),
1164 (unsigned long long)sh->sector + rdev->data_offset,
1166 else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
1168 printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
1169 mdname(conf->mddev),
1170 (unsigned long long)sh->sector + rdev->data_offset,
1172 else if (atomic_read(&rdev->read_errors)
1173 > conf->max_nr_stripes)
1175 "raid5:%s: Too many read errors, failing device %s.\n",
1176 mdname(conf->mddev), bdn);
1180 set_bit(R5_ReadError, &sh->dev[i].flags);
1182 clear_bit(R5_ReadError, &sh->dev[i].flags);
1183 clear_bit(R5_ReWrite, &sh->dev[i].flags);
1184 md_error(conf->mddev, rdev);
1187 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1188 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1189 set_bit(STRIPE_HANDLE, &sh->state);
1194 static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
1197 struct stripe_head *sh = bi->bi_private;
1198 raid5_conf_t *conf = sh->raid_conf;
1199 int disks = sh->disks, i;
1200 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
1205 for (i=0 ; i<disks; i++)
1206 if (bi == &sh->dev[i].req)
1209 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1210 (unsigned long long)sh->sector, i, atomic_read(&sh->count),
1218 md_error(conf->mddev, conf->disks[i].rdev);
1220 rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
1222 clear_bit(R5_LOCKED, &sh->dev[i].flags);
1223 set_bit(STRIPE_HANDLE, &sh->state);
1229 static sector_t compute_blocknr(struct stripe_head *sh, int i);
1231 static void raid5_build_block (struct stripe_head *sh, int i)
1233 struct r5dev *dev = &sh->dev[i];
1235 bio_init(&dev->req);
1236 dev->req.bi_io_vec = &dev->vec;
1238 dev->req.bi_max_vecs++;
1239 dev->vec.bv_page = dev->page;
1240 dev->vec.bv_len = STRIPE_SIZE;
1241 dev->vec.bv_offset = 0;
1243 dev->req.bi_sector = sh->sector;
1244 dev->req.bi_private = sh;
1247 dev->sector = compute_blocknr(sh, i);
1250 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1252 char b[BDEVNAME_SIZE];
1253 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
1254 pr_debug("raid5: error called\n");
1256 if (!test_bit(Faulty, &rdev->flags)) {
1257 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1258 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1259 unsigned long flags;
1260 spin_lock_irqsave(&conf->device_lock, flags);
1262 spin_unlock_irqrestore(&conf->device_lock, flags);
1264 * if recovery was running, make sure it aborts.
1266 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
1268 set_bit(Faulty, &rdev->flags);
1270 "raid5: Disk failure on %s, disabling device."
1271 " Operation continuing on %d devices\n",
1272 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
1277 * Input: a 'big' sector number,
1278 * Output: index of the data and parity disk, and the sector # in them.
1280 static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
1281 unsigned int data_disks, unsigned int * dd_idx,
1282 unsigned int * pd_idx, raid5_conf_t *conf)
1285 unsigned long chunk_number;
1286 unsigned int chunk_offset;
1287 sector_t new_sector;
1288 int sectors_per_chunk = conf->chunk_size >> 9;
1290 /* First compute the information on this sector */
1293 * Compute the chunk number and the sector offset inside the chunk
1295 chunk_offset = sector_div(r_sector, sectors_per_chunk);
1296 chunk_number = r_sector;
1297 BUG_ON(r_sector != chunk_number);
1300 * Compute the stripe number
1302 stripe = chunk_number / data_disks;
1305 * Compute the data disk and parity disk indexes inside the stripe
1307 *dd_idx = chunk_number % data_disks;
1310 * Select the parity disk based on the user selected algorithm.
1312 switch(conf->level) {
1314 *pd_idx = data_disks;
1317 switch (conf->algorithm) {
1318 case ALGORITHM_LEFT_ASYMMETRIC:
1319 *pd_idx = data_disks - stripe % raid_disks;
1320 if (*dd_idx >= *pd_idx)
1323 case ALGORITHM_RIGHT_ASYMMETRIC:
1324 *pd_idx = stripe % raid_disks;
1325 if (*dd_idx >= *pd_idx)
1328 case ALGORITHM_LEFT_SYMMETRIC:
1329 *pd_idx = data_disks - stripe % raid_disks;
1330 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1332 case ALGORITHM_RIGHT_SYMMETRIC:
1333 *pd_idx = stripe % raid_disks;
1334 *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
1337 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
1343 /**** FIX THIS ****/
1344 switch (conf->algorithm) {
1345 case ALGORITHM_LEFT_ASYMMETRIC:
1346 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1347 if (*pd_idx == raid_disks-1)
1348 (*dd_idx)++; /* Q D D D P */
1349 else if (*dd_idx >= *pd_idx)
1350 (*dd_idx) += 2; /* D D P Q D */
1352 case ALGORITHM_RIGHT_ASYMMETRIC:
1353 *pd_idx = stripe % raid_disks;
1354 if (*pd_idx == raid_disks-1)
1355 (*dd_idx)++; /* Q D D D P */
1356 else if (*dd_idx >= *pd_idx)
1357 (*dd_idx) += 2; /* D D P Q D */
1359 case ALGORITHM_LEFT_SYMMETRIC:
1360 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
1361 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1363 case ALGORITHM_RIGHT_SYMMETRIC:
1364 *pd_idx = stripe % raid_disks;
1365 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
1368 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
1375 * Finally, compute the new sector number
1377 new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
1382 static sector_t compute_blocknr(struct stripe_head *sh, int i)
1384 raid5_conf_t *conf = sh->raid_conf;
1385 int raid_disks = sh->disks;
1386 int data_disks = raid_disks - conf->max_degraded;
1387 sector_t new_sector = sh->sector, check;
1388 int sectors_per_chunk = conf->chunk_size >> 9;
1391 int chunk_number, dummy1, dummy2, dd_idx = i;
1395 chunk_offset = sector_div(new_sector, sectors_per_chunk);
1396 stripe = new_sector;
1397 BUG_ON(new_sector != stripe);
1399 if (i == sh->pd_idx)
1401 switch(conf->level) {
1404 switch (conf->algorithm) {
1405 case ALGORITHM_LEFT_ASYMMETRIC:
1406 case ALGORITHM_RIGHT_ASYMMETRIC:
1410 case ALGORITHM_LEFT_SYMMETRIC:
1411 case ALGORITHM_RIGHT_SYMMETRIC:
1414 i -= (sh->pd_idx + 1);
1417 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
1422 if (i == raid6_next_disk(sh->pd_idx, raid_disks))
1423 return 0; /* It is the Q disk */
1424 switch (conf->algorithm) {
1425 case ALGORITHM_LEFT_ASYMMETRIC:
1426 case ALGORITHM_RIGHT_ASYMMETRIC:
1427 if (sh->pd_idx == raid_disks-1)
1428 i--; /* Q D D D P */
1429 else if (i > sh->pd_idx)
1430 i -= 2; /* D D P Q D */
1432 case ALGORITHM_LEFT_SYMMETRIC:
1433 case ALGORITHM_RIGHT_SYMMETRIC:
1434 if (sh->pd_idx == raid_disks-1)
1435 i--; /* Q D D D P */
1440 i -= (sh->pd_idx + 2);
1444 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
1450 chunk_number = stripe * data_disks + i;
1451 r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
1453 check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
1454 if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
1455 printk(KERN_ERR "compute_blocknr: map not correct\n");
1464 * Copy data between a page in the stripe cache, and one or more bion
1465 * The page could align with the middle of the bio, or there could be
1466 * several bion, each with several bio_vecs, which cover part of the page
1467 * Multiple bion are linked together on bi_next. There may be extras
1468 * at the end of this list. We ignore them.
1470 static void copy_data(int frombio, struct bio *bio,
1474 char *pa = page_address(page);
1475 struct bio_vec *bvl;
1479 if (bio->bi_sector >= sector)
1480 page_offset = (signed)(bio->bi_sector - sector) * 512;
1482 page_offset = (signed)(sector - bio->bi_sector) * -512;
1483 bio_for_each_segment(bvl, bio, i) {
1484 int len = bio_iovec_idx(bio,i)->bv_len;
1488 if (page_offset < 0) {
1489 b_offset = -page_offset;
1490 page_offset += b_offset;
1494 if (len > 0 && page_offset + len > STRIPE_SIZE)
1495 clen = STRIPE_SIZE - page_offset;
1499 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
1501 memcpy(pa+page_offset, ba+b_offset, clen);
1503 memcpy(ba+b_offset, pa+page_offset, clen);
1504 __bio_kunmap_atomic(ba, KM_USER0);
1506 if (clen < len) /* hit end of page */
1512 #define check_xor() do { \
1513 if (count == MAX_XOR_BLOCKS) { \
1514 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1520 static void compute_block(struct stripe_head *sh, int dd_idx)
1522 int i, count, disks = sh->disks;
1523 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
1525 pr_debug("compute_block, stripe %llu, idx %d\n",
1526 (unsigned long long)sh->sector, dd_idx);
1528 dest = page_address(sh->dev[dd_idx].page);
1529 memset(dest, 0, STRIPE_SIZE);
1531 for (i = disks ; i--; ) {
1534 p = page_address(sh->dev[i].page);
1535 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1538 printk(KERN_ERR "compute_block() %d, stripe %llu, %d"
1539 " not present\n", dd_idx,
1540 (unsigned long long)sh->sector, i);
1545 xor_blocks(count, STRIPE_SIZE, dest, ptr);
1546 set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1549 static void compute_parity5(struct stripe_head *sh, int method)
1551 raid5_conf_t *conf = sh->raid_conf;
1552 int i, pd_idx = sh->pd_idx, disks = sh->disks, count;
1553 void *ptr[MAX_XOR_BLOCKS], *dest;
1556 pr_debug("compute_parity5, stripe %llu, method %d\n",
1557 (unsigned long long)sh->sector, method);
1560 dest = page_address(sh->dev[pd_idx].page);
1562 case READ_MODIFY_WRITE:
1563 BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags));
1564 for (i=disks ; i-- ;) {
1567 if (sh->dev[i].towrite &&
1568 test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
1569 ptr[count++] = page_address(sh->dev[i].page);
1570 chosen = sh->dev[i].towrite;
1571 sh->dev[i].towrite = NULL;
1573 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1574 wake_up(&conf->wait_for_overlap);
1576 BUG_ON(sh->dev[i].written);
1577 sh->dev[i].written = chosen;
1582 case RECONSTRUCT_WRITE:
1583 memset(dest, 0, STRIPE_SIZE);
1584 for (i= disks; i-- ;)
1585 if (i!=pd_idx && sh->dev[i].towrite) {
1586 chosen = sh->dev[i].towrite;
1587 sh->dev[i].towrite = NULL;
1589 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1590 wake_up(&conf->wait_for_overlap);
1592 BUG_ON(sh->dev[i].written);
1593 sh->dev[i].written = chosen;
1600 xor_blocks(count, STRIPE_SIZE, dest, ptr);
1604 for (i = disks; i--;)
1605 if (sh->dev[i].written) {
1606 sector_t sector = sh->dev[i].sector;
1607 struct bio *wbi = sh->dev[i].written;
1608 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1609 copy_data(1, wbi, sh->dev[i].page, sector);
1610 wbi = r5_next_bio(wbi, sector);
1613 set_bit(R5_LOCKED, &sh->dev[i].flags);
1614 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1618 case RECONSTRUCT_WRITE:
1622 ptr[count++] = page_address(sh->dev[i].page);
1626 case READ_MODIFY_WRITE:
1627 for (i = disks; i--;)
1628 if (sh->dev[i].written) {
1629 ptr[count++] = page_address(sh->dev[i].page);
1634 xor_blocks(count, STRIPE_SIZE, dest, ptr);
1636 if (method != CHECK_PARITY) {
1637 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1638 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1640 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1643 static void compute_parity6(struct stripe_head *sh, int method)
1645 raid6_conf_t *conf = sh->raid_conf;
1646 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
1648 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1651 qd_idx = raid6_next_disk(pd_idx, disks);
1652 d0_idx = raid6_next_disk(qd_idx, disks);
1654 pr_debug("compute_parity, stripe %llu, method %d\n",
1655 (unsigned long long)sh->sector, method);
1658 case READ_MODIFY_WRITE:
1659 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1660 case RECONSTRUCT_WRITE:
1661 for (i= disks; i-- ;)
1662 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1663 chosen = sh->dev[i].towrite;
1664 sh->dev[i].towrite = NULL;
1666 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1667 wake_up(&conf->wait_for_overlap);
1669 BUG_ON(sh->dev[i].written);
1670 sh->dev[i].written = chosen;
1674 BUG(); /* Not implemented yet */
1677 for (i = disks; i--;)
1678 if (sh->dev[i].written) {
1679 sector_t sector = sh->dev[i].sector;
1680 struct bio *wbi = sh->dev[i].written;
1681 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1682 copy_data(1, wbi, sh->dev[i].page, sector);
1683 wbi = r5_next_bio(wbi, sector);
1686 set_bit(R5_LOCKED, &sh->dev[i].flags);
1687 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1691 // case RECONSTRUCT_WRITE:
1692 // case CHECK_PARITY:
1693 // case UPDATE_PARITY:
1694 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1695 /* FIX: Is this ordering of drives even remotely optimal? */
1699 ptrs[count++] = page_address(sh->dev[i].page);
1700 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1701 printk("block %d/%d not uptodate on parity calc\n", i,count);
1702 i = raid6_next_disk(i, disks);
1703 } while ( i != d0_idx );
1707 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
1710 case RECONSTRUCT_WRITE:
1711 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1712 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1713 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1714 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1717 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1718 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1724 /* Compute one missing block */
1725 static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1727 int i, count, disks = sh->disks;
1728 void *ptr[MAX_XOR_BLOCKS], *dest, *p;
1729 int pd_idx = sh->pd_idx;
1730 int qd_idx = raid6_next_disk(pd_idx, disks);
1732 pr_debug("compute_block_1, stripe %llu, idx %d\n",
1733 (unsigned long long)sh->sector, dd_idx);
1735 if ( dd_idx == qd_idx ) {
1736 /* We're actually computing the Q drive */
1737 compute_parity6(sh, UPDATE_PARITY);
1739 dest = page_address(sh->dev[dd_idx].page);
1740 if (!nozero) memset(dest, 0, STRIPE_SIZE);
1742 for (i = disks ; i--; ) {
1743 if (i == dd_idx || i == qd_idx)
1745 p = page_address(sh->dev[i].page);
1746 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1749 printk("compute_block() %d, stripe %llu, %d"
1750 " not present\n", dd_idx,
1751 (unsigned long long)sh->sector, i);
1756 xor_blocks(count, STRIPE_SIZE, dest, ptr);
1757 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1758 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1762 /* Compute two missing blocks */
1763 static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1765 int i, count, disks = sh->disks;
1766 int pd_idx = sh->pd_idx;
1767 int qd_idx = raid6_next_disk(pd_idx, disks);
1768 int d0_idx = raid6_next_disk(qd_idx, disks);
1771 /* faila and failb are disk numbers relative to d0_idx */
1772 /* pd_idx become disks-2 and qd_idx become disks-1 */
1773 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
1774 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
1776 BUG_ON(faila == failb);
1777 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1779 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1780 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
1782 if ( failb == disks-1 ) {
1783 /* Q disk is one of the missing disks */
1784 if ( faila == disks-2 ) {
1785 /* Missing P+Q, just recompute */
1786 compute_parity6(sh, UPDATE_PARITY);
1789 /* We're missing D+Q; recompute D from P */
1790 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0);
1791 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1796 /* We're missing D+P or D+D; build pointer table */
1798 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1804 ptrs[count++] = page_address(sh->dev[i].page);
1805 i = raid6_next_disk(i, disks);
1806 if (i != dd_idx1 && i != dd_idx2 &&
1807 !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1808 printk("compute_2 with missing block %d/%d\n", count, i);
1809 } while ( i != d0_idx );
1811 if ( failb == disks-2 ) {
1812 /* We're missing D+P. */
1813 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
1815 /* We're missing D+D. */
1816 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
1819 /* Both the above update both missing blocks */
1820 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1821 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1828 * Each stripe/dev can have one or more bion attached.
1829 * toread/towrite point to the first in a chain.
1830 * The bi_next chain must be in order.
1832 static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
1835 raid5_conf_t *conf = sh->raid_conf;
1838 pr_debug("adding bh b#%llu to stripe s#%llu\n",
1839 (unsigned long long)bi->bi_sector,
1840 (unsigned long long)sh->sector);
1843 spin_lock(&sh->lock);
1844 spin_lock_irq(&conf->device_lock);
1846 bip = &sh->dev[dd_idx].towrite;
1847 if (*bip == NULL && sh->dev[dd_idx].written == NULL)
1850 bip = &sh->dev[dd_idx].toread;
1851 while (*bip && (*bip)->bi_sector < bi->bi_sector) {
1852 if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
1854 bip = & (*bip)->bi_next;
1856 if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
1859 BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
1863 bi->bi_phys_segments ++;
1864 spin_unlock_irq(&conf->device_lock);
1865 spin_unlock(&sh->lock);
1867 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
1868 (unsigned long long)bi->bi_sector,
1869 (unsigned long long)sh->sector, dd_idx);
1871 if (conf->mddev->bitmap && firstwrite) {
1872 bitmap_startwrite(conf->mddev->bitmap, sh->sector,
1874 sh->bm_seq = conf->seq_flush+1;
1875 set_bit(STRIPE_BIT_DELAY, &sh->state);
1879 /* check if page is covered */
1880 sector_t sector = sh->dev[dd_idx].sector;
1881 for (bi=sh->dev[dd_idx].towrite;
1882 sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
1883 bi && bi->bi_sector <= sector;
1884 bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
1885 if (bi->bi_sector + (bi->bi_size>>9) >= sector)
1886 sector = bi->bi_sector + (bi->bi_size>>9);
1888 if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
1889 set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
1894 set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
1895 spin_unlock_irq(&conf->device_lock);
1896 spin_unlock(&sh->lock);
1900 static void end_reshape(raid5_conf_t *conf);
1902 static int page_is_zero(struct page *p)
1904 char *a = page_address(p);
1905 return ((*(u32*)a) == 0 &&
1906 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1909 static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1911 int sectors_per_chunk = conf->chunk_size >> 9;
1913 int chunk_offset = sector_div(stripe, sectors_per_chunk);
1915 raid5_compute_sector(stripe * (disks - conf->max_degraded)
1916 *sectors_per_chunk + chunk_offset,
1917 disks, disks - conf->max_degraded,
1918 &dd_idx, &pd_idx, conf);
1923 handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
1924 struct stripe_head_state *s, int disks,
1925 struct bio **return_bi)
1928 for (i = disks; i--; ) {
1932 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1935 rdev = rcu_dereference(conf->disks[i].rdev);
1936 if (rdev && test_bit(In_sync, &rdev->flags))
1937 /* multiple read failures in one stripe */
1938 md_error(conf->mddev, rdev);
1941 spin_lock_irq(&conf->device_lock);
1942 /* fail all writes first */
1943 bi = sh->dev[i].towrite;
1944 sh->dev[i].towrite = NULL;
1950 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1951 wake_up(&conf->wait_for_overlap);
1953 while (bi && bi->bi_sector <
1954 sh->dev[i].sector + STRIPE_SECTORS) {
1955 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
1956 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1957 if (--bi->bi_phys_segments == 0) {
1958 md_write_end(conf->mddev);
1959 bi->bi_next = *return_bi;
1964 /* and fail all 'written' */
1965 bi = sh->dev[i].written;
1966 sh->dev[i].written = NULL;
1967 if (bi) bitmap_end = 1;
1968 while (bi && bi->bi_sector <
1969 sh->dev[i].sector + STRIPE_SECTORS) {
1970 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
1971 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1972 if (--bi->bi_phys_segments == 0) {
1973 md_write_end(conf->mddev);
1974 bi->bi_next = *return_bi;
1980 /* fail any reads if this device is non-operational */
1981 if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
1982 test_bit(R5_ReadError, &sh->dev[i].flags)) {
1983 bi = sh->dev[i].toread;
1984 sh->dev[i].toread = NULL;
1985 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1986 wake_up(&conf->wait_for_overlap);
1987 if (bi) s->to_read--;
1988 while (bi && bi->bi_sector <
1989 sh->dev[i].sector + STRIPE_SECTORS) {
1990 struct bio *nextbi =
1991 r5_next_bio(bi, sh->dev[i].sector);
1992 clear_bit(BIO_UPTODATE, &bi->bi_flags);
1993 if (--bi->bi_phys_segments == 0) {
1994 bi->bi_next = *return_bi;
2000 spin_unlock_irq(&conf->device_lock);
2002 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2003 STRIPE_SECTORS, 0, 0);
2008 static void handle_issuing_new_read_requests5(struct stripe_head *sh,
2009 struct stripe_head_state *s, int disks)
2012 for (i = disks; i--; ) {
2013 struct r5dev *dev = &sh->dev[i];
2014 if (!test_bit(R5_LOCKED, &dev->flags) &&
2015 !test_bit(R5_UPTODATE, &dev->flags) &&
2017 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2018 s->syncing || s->expanding ||
2019 (s->failed && (sh->dev[s->failed_num].toread ||
2020 (sh->dev[s->failed_num].towrite &&
2021 !test_bit(R5_OVERWRITE, &sh->dev[s->failed_num].flags))
2023 /* we would like to get this block, possibly
2024 * by computing it, but we might not be able to
2026 if (s->uptodate == disks-1) {
2027 pr_debug("Computing block %d\n", i);
2028 compute_block(sh, i);
2030 } else if (test_bit(R5_Insync, &dev->flags)) {
2031 set_bit(R5_LOCKED, &dev->flags);
2032 set_bit(R5_Wantread, &dev->flags);
2034 pr_debug("Reading block %d (sync=%d)\n",
2039 set_bit(STRIPE_HANDLE, &sh->state);
2042 static void handle_issuing_new_read_requests6(struct stripe_head *sh,
2043 struct stripe_head_state *s, struct r6_state *r6s,
2047 for (i = disks; i--; ) {
2048 struct r5dev *dev = &sh->dev[i];
2049 if (!test_bit(R5_LOCKED, &dev->flags) &&
2050 !test_bit(R5_UPTODATE, &dev->flags) &&
2051 (dev->toread || (dev->towrite &&
2052 !test_bit(R5_OVERWRITE, &dev->flags)) ||
2053 s->syncing || s->expanding ||
2055 (sh->dev[r6s->failed_num[0]].toread ||
2058 (sh->dev[r6s->failed_num[1]].toread ||
2060 /* we would like to get this block, possibly
2061 * by computing it, but we might not be able to
2063 if (s->uptodate == disks-1) {
2064 pr_debug("Computing stripe %llu block %d\n",
2065 (unsigned long long)sh->sector, i);
2066 compute_block_1(sh, i, 0);
2068 } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
2069 /* Computing 2-failure is *very* expensive; only
2070 * do it if failed >= 2
2073 for (other = disks; other--; ) {
2076 if (!test_bit(R5_UPTODATE,
2077 &sh->dev[other].flags))
2081 pr_debug("Computing stripe %llu blocks %d,%d\n",
2082 (unsigned long long)sh->sector,
2084 compute_block_2(sh, i, other);
2086 } else if (test_bit(R5_Insync, &dev->flags)) {
2087 set_bit(R5_LOCKED, &dev->flags);
2088 set_bit(R5_Wantread, &dev->flags);
2090 pr_debug("Reading block %d (sync=%d)\n",
2095 set_bit(STRIPE_HANDLE, &sh->state);
2099 /* handle_completed_write_requests
2100 * any written block on an uptodate or failed drive can be returned.
2101 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2102 * never LOCKED, so we don't need to test 'failed' directly.
2104 static void handle_completed_write_requests(raid5_conf_t *conf,
2105 struct stripe_head *sh, int disks, struct bio **return_bi)
2110 for (i = disks; i--; )
2111 if (sh->dev[i].written) {
2113 if (!test_bit(R5_LOCKED, &dev->flags) &&
2114 test_bit(R5_UPTODATE, &dev->flags)) {
2115 /* We can return any write requests */
2116 struct bio *wbi, *wbi2;
2118 pr_debug("Return write for disc %d\n", i);
2119 spin_lock_irq(&conf->device_lock);
2121 dev->written = NULL;
2122 while (wbi && wbi->bi_sector <
2123 dev->sector + STRIPE_SECTORS) {
2124 wbi2 = r5_next_bio(wbi, dev->sector);
2125 if (--wbi->bi_phys_segments == 0) {
2126 md_write_end(conf->mddev);
2127 wbi->bi_next = *return_bi;
2132 if (dev->towrite == NULL)
2134 spin_unlock_irq(&conf->device_lock);
2136 bitmap_endwrite(conf->mddev->bitmap,
2139 !test_bit(STRIPE_DEGRADED, &sh->state),
2145 static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
2146 struct stripe_head *sh, struct stripe_head_state *s, int disks)
2148 int rmw = 0, rcw = 0, i;
2149 for (i = disks; i--; ) {
2150 /* would I have to read this buffer for read_modify_write */
2151 struct r5dev *dev = &sh->dev[i];
2152 if ((dev->towrite || i == sh->pd_idx) &&
2153 !test_bit(R5_LOCKED, &dev->flags) &&
2154 !test_bit(R5_UPTODATE, &dev->flags)) {
2155 if (test_bit(R5_Insync, &dev->flags))
2158 rmw += 2*disks; /* cannot read it */
2160 /* Would I have to read this buffer for reconstruct_write */
2161 if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
2162 !test_bit(R5_LOCKED, &dev->flags) &&
2163 !test_bit(R5_UPTODATE, &dev->flags)) {
2164 if (test_bit(R5_Insync, &dev->flags))
2170 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2171 (unsigned long long)sh->sector, rmw, rcw);
2172 set_bit(STRIPE_HANDLE, &sh->state);
2173 if (rmw < rcw && rmw > 0)
2174 /* prefer read-modify-write, but need to get some data */
2175 for (i = disks; i--; ) {
2176 struct r5dev *dev = &sh->dev[i];
2177 if ((dev->towrite || i == sh->pd_idx) &&
2178 !test_bit(R5_LOCKED, &dev->flags) &&
2179 !test_bit(R5_UPTODATE, &dev->flags) &&
2180 test_bit(R5_Insync, &dev->flags)) {
2182 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2183 pr_debug("Read_old block "
2184 "%d for r-m-w\n", i);
2185 set_bit(R5_LOCKED, &dev->flags);
2186 set_bit(R5_Wantread, &dev->flags);
2189 set_bit(STRIPE_DELAYED, &sh->state);
2190 set_bit(STRIPE_HANDLE, &sh->state);
2194 if (rcw <= rmw && rcw > 0)
2195 /* want reconstruct write, but need to get some data */
2196 for (i = disks; i--; ) {
2197 struct r5dev *dev = &sh->dev[i];
2198 if (!test_bit(R5_OVERWRITE, &dev->flags) &&
2200 !test_bit(R5_LOCKED, &dev->flags) &&
2201 !test_bit(R5_UPTODATE, &dev->flags) &&
2202 test_bit(R5_Insync, &dev->flags)) {
2204 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2205 pr_debug("Read_old block "
2206 "%d for Reconstruct\n", i);
2207 set_bit(R5_LOCKED, &dev->flags);
2208 set_bit(R5_Wantread, &dev->flags);
2211 set_bit(STRIPE_DELAYED, &sh->state);
2212 set_bit(STRIPE_HANDLE, &sh->state);
2216 /* now if nothing is locked, and if we have enough data,
2217 * we can start a write request
2219 if (s->locked == 0 && (rcw == 0 || rmw == 0) &&
2220 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2221 pr_debug("Computing parity...\n");
2222 compute_parity5(sh, rcw == 0 ?
2223 RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
2224 /* now every locked buffer is ready to be written */
2225 for (i = disks; i--; )
2226 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
2227 pr_debug("Writing block %d\n", i);
2229 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2230 if (!test_bit(R5_Insync, &sh->dev[i].flags)
2231 || (i == sh->pd_idx && s->failed == 0))
2232 set_bit(STRIPE_INSYNC, &sh->state);
2234 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2235 atomic_dec(&conf->preread_active_stripes);
2236 if (atomic_read(&conf->preread_active_stripes) <
2238 md_wakeup_thread(conf->mddev->thread);
2243 static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
2244 struct stripe_head *sh, struct stripe_head_state *s,
2245 struct r6_state *r6s, int disks)
2247 int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
2248 int qd_idx = r6s->qd_idx;
2249 for (i = disks; i--; ) {
2250 struct r5dev *dev = &sh->dev[i];
2251 /* Would I have to read this buffer for reconstruct_write */
2252 if (!test_bit(R5_OVERWRITE, &dev->flags)
2253 && i != pd_idx && i != qd_idx
2254 && (!test_bit(R5_LOCKED, &dev->flags)
2256 !test_bit(R5_UPTODATE, &dev->flags)) {
2257 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2259 pr_debug("raid6: must_compute: "
2260 "disk %d flags=%#lx\n", i, dev->flags);
2265 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
2266 (unsigned long long)sh->sector, rcw, must_compute);
2267 set_bit(STRIPE_HANDLE, &sh->state);
2270 /* want reconstruct write, but need to get some data */
2271 for (i = disks; i--; ) {
2272 struct r5dev *dev = &sh->dev[i];
2273 if (!test_bit(R5_OVERWRITE, &dev->flags)
2274 && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
2275 && !test_bit(R5_LOCKED, &dev->flags) &&
2276 !test_bit(R5_UPTODATE, &dev->flags) &&
2277 test_bit(R5_Insync, &dev->flags)) {
2279 test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2280 pr_debug("Read_old stripe %llu "
2281 "block %d for Reconstruct\n",
2282 (unsigned long long)sh->sector, i);
2283 set_bit(R5_LOCKED, &dev->flags);
2284 set_bit(R5_Wantread, &dev->flags);
2287 pr_debug("Request delayed stripe %llu "
2288 "block %d for Reconstruct\n",
2289 (unsigned long long)sh->sector, i);
2290 set_bit(STRIPE_DELAYED, &sh->state);
2291 set_bit(STRIPE_HANDLE, &sh->state);
2295 /* now if nothing is locked, and if we have enough data, we can start a
2298 if (s->locked == 0 && rcw == 0 &&
2299 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2300 if (must_compute > 0) {
2301 /* We have failed blocks and need to compute them */
2302 switch (s->failed) {
2306 compute_block_1(sh, r6s->failed_num[0], 0);
2309 compute_block_2(sh, r6s->failed_num[0],
2310 r6s->failed_num[1]);
2312 default: /* This request should have been failed? */
2317 pr_debug("Computing parity for stripe %llu\n",
2318 (unsigned long long)sh->sector);
2319 compute_parity6(sh, RECONSTRUCT_WRITE);
2320 /* now every locked buffer is ready to be written */
2321 for (i = disks; i--; )
2322 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
2323 pr_debug("Writing stripe %llu block %d\n",
2324 (unsigned long long)sh->sector, i);
2326 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2328 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2329 set_bit(STRIPE_INSYNC, &sh->state);
2331 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2332 atomic_dec(&conf->preread_active_stripes);
2333 if (atomic_read(&conf->preread_active_stripes) <
2335 md_wakeup_thread(conf->mddev->thread);
2340 static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
2341 struct stripe_head_state *s, int disks)
2343 set_bit(STRIPE_HANDLE, &sh->state);
2344 if (s->failed == 0) {
2345 BUG_ON(s->uptodate != disks);
2346 compute_parity5(sh, CHECK_PARITY);
2348 if (page_is_zero(sh->dev[sh->pd_idx].page)) {
2349 /* parity is correct (on disc, not in buffer any more)
2351 set_bit(STRIPE_INSYNC, &sh->state);
2353 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2354 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2355 /* don't try to repair!! */
2356 set_bit(STRIPE_INSYNC, &sh->state);
2358 compute_block(sh, sh->pd_idx);
2363 if (!test_bit(STRIPE_INSYNC, &sh->state)) {
2365 /* either failed parity check, or recovery is happening */
2367 s->failed_num = sh->pd_idx;
2368 dev = &sh->dev[s->failed_num];
2369 BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
2370 BUG_ON(s->uptodate != disks);
2372 set_bit(R5_LOCKED, &dev->flags);
2373 set_bit(R5_Wantwrite, &dev->flags);
2374 clear_bit(STRIPE_DEGRADED, &sh->state);
2376 set_bit(STRIPE_INSYNC, &sh->state);
2381 static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
2382 struct stripe_head_state *s,
2383 struct r6_state *r6s, struct page *tmp_page,
2386 int update_p = 0, update_q = 0;
2388 int pd_idx = sh->pd_idx;
2389 int qd_idx = r6s->qd_idx;
2391 set_bit(STRIPE_HANDLE, &sh->state);
2393 BUG_ON(s->failed > 2);
2394 BUG_ON(s->uptodate < disks);
2395 /* Want to check and possibly repair P and Q.
2396 * However there could be one 'failed' device, in which
2397 * case we can only check one of them, possibly using the
2398 * other to generate missing data
2401 /* If !tmp_page, we cannot do the calculations,
2402 * but as we have set STRIPE_HANDLE, we will soon be called
2403 * by stripe_handle with a tmp_page - just wait until then.
2406 if (s->failed == r6s->q_failed) {
2407 /* The only possible failed device holds 'Q', so it
2408 * makes sense to check P (If anything else were failed,
2409 * we would have used P to recreate it).
2411 compute_block_1(sh, pd_idx, 1);
2412 if (!page_is_zero(sh->dev[pd_idx].page)) {
2413 compute_block_1(sh, pd_idx, 0);
2417 if (!r6s->q_failed && s->failed < 2) {
2418 /* q is not failed, and we didn't use it to generate
2419 * anything, so it makes sense to check it
2421 memcpy(page_address(tmp_page),
2422 page_address(sh->dev[qd_idx].page),
2424 compute_parity6(sh, UPDATE_PARITY);
2425 if (memcmp(page_address(tmp_page),
2426 page_address(sh->dev[qd_idx].page),
2427 STRIPE_SIZE) != 0) {
2428 clear_bit(STRIPE_INSYNC, &sh->state);
2432 if (update_p || update_q) {
2433 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2434 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2435 /* don't try to repair!! */
2436 update_p = update_q = 0;
2439 /* now write out any block on a failed drive,
2440 * or P or Q if they need it
2443 if (s->failed == 2) {
2444 dev = &sh->dev[r6s->failed_num[1]];
2446 set_bit(R5_LOCKED, &dev->flags);
2447 set_bit(R5_Wantwrite, &dev->flags);
2449 if (s->failed >= 1) {
2450 dev = &sh->dev[r6s->failed_num[0]];
2452 set_bit(R5_LOCKED, &dev->flags);
2453 set_bit(R5_Wantwrite, &dev->flags);
2457 dev = &sh->dev[pd_idx];
2459 set_bit(R5_LOCKED, &dev->flags);
2460 set_bit(R5_Wantwrite, &dev->flags);
2463 dev = &sh->dev[qd_idx];
2465 set_bit(R5_LOCKED, &dev->flags);
2466 set_bit(R5_Wantwrite, &dev->flags);
2468 clear_bit(STRIPE_DEGRADED, &sh->state);
2470 set_bit(STRIPE_INSYNC, &sh->state);
2474 static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
2475 struct r6_state *r6s)
2479 /* We have read all the blocks in this stripe and now we need to
2480 * copy some of them into a target stripe for expand.
2482 clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2483 for (i = 0; i < sh->disks; i++)
2484 if (i != sh->pd_idx && (r6s && i != r6s->qd_idx)) {
2485 int dd_idx, pd_idx, j;
2486 struct stripe_head *sh2;
2488 sector_t bn = compute_blocknr(sh, i);
2489 sector_t s = raid5_compute_sector(bn, conf->raid_disks,
2491 conf->max_degraded, &dd_idx,
2493 sh2 = get_active_stripe(conf, s, conf->raid_disks,
2496 /* so far only the early blocks of this stripe
2497 * have been requested. When later blocks
2498 * get requested, we will try again
2501 if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
2502 test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
2503 /* must have already done this block */
2504 release_stripe(sh2);
2507 memcpy(page_address(sh2->dev[dd_idx].page),
2508 page_address(sh->dev[i].page),
2510 set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
2511 set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
2512 for (j = 0; j < conf->raid_disks; j++)
2513 if (j != sh2->pd_idx &&
2514 (r6s && j != r6s->qd_idx) &&
2515 !test_bit(R5_Expanded, &sh2->dev[j].flags))
2517 if (j == conf->raid_disks) {
2518 set_bit(STRIPE_EXPAND_READY, &sh2->state);
2519 set_bit(STRIPE_HANDLE, &sh2->state);
2521 release_stripe(sh2);
2526 * handle_stripe - do things to a stripe.
2528 * We lock the stripe and then examine the state of various bits
2529 * to see what needs to be done.
2531 * return some read request which now have data
2532 * return some write requests which are safely on disc
2533 * schedule a read on some buffers
2534 * schedule a write of some buffers
2535 * return confirmation of parity correctness
2537 * buffers are taken off read_list or write_list, and bh_cache buffers
2538 * get BH_Lock set before the stripe lock is released.
2542 static void handle_stripe5(struct stripe_head *sh)
2544 raid5_conf_t *conf = sh->raid_conf;
2545 int disks = sh->disks, i;
2546 struct bio *return_bi = NULL;
2547 struct stripe_head_state s;
2549 unsigned long pending = 0;
2551 memset(&s, 0, sizeof(s));
2552 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d "
2553 "ops=%lx:%lx:%lx\n", (unsigned long long)sh->sector, sh->state,
2554 atomic_read(&sh->count), sh->pd_idx,
2555 sh->ops.pending, sh->ops.ack, sh->ops.complete);
2557 spin_lock(&sh->lock);
2558 clear_bit(STRIPE_HANDLE, &sh->state);
2559 clear_bit(STRIPE_DELAYED, &sh->state);
2561 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2562 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2563 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
2564 /* Now to look around and see what can be done */
2567 for (i=disks; i--; ) {
2569 struct r5dev *dev = &sh->dev[i];
2570 clear_bit(R5_Insync, &dev->flags);
2572 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
2573 i, dev->flags, dev->toread, dev->towrite, dev->written);
2574 /* maybe we can reply to a read */
2575 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
2576 struct bio *rbi, *rbi2;
2577 pr_debug("Return read for disc %d\n", i);
2578 spin_lock_irq(&conf->device_lock);
2581 if (test_and_clear_bit(R5_Overlap, &dev->flags))
2582 wake_up(&conf->wait_for_overlap);
2583 spin_unlock_irq(&conf->device_lock);
2584 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2585 copy_data(0, rbi, dev->page, dev->sector);
2586 rbi2 = r5_next_bio(rbi, dev->sector);
2587 spin_lock_irq(&conf->device_lock);
2588 if (--rbi->bi_phys_segments == 0) {
2589 rbi->bi_next = return_bi;
2592 spin_unlock_irq(&conf->device_lock);
2597 /* now count some things */
2598 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2599 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
2605 if (!test_bit(R5_OVERWRITE, &dev->flags))
2610 rdev = rcu_dereference(conf->disks[i].rdev);
2611 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
2612 /* The ReadError flag will just be confusing now */
2613 clear_bit(R5_ReadError, &dev->flags);
2614 clear_bit(R5_ReWrite, &dev->flags);
2616 if (!rdev || !test_bit(In_sync, &rdev->flags)
2617 || test_bit(R5_ReadError, &dev->flags)) {
2621 set_bit(R5_Insync, &dev->flags);
2624 pr_debug("locked=%d uptodate=%d to_read=%d"
2625 " to_write=%d failed=%d failed_num=%d\n",
2626 s.locked, s.uptodate, s.to_read, s.to_write,
2627 s.failed, s.failed_num);
2628 /* check if the array has lost two devices and, if so, some requests might
2631 if (s.failed > 1 && s.to_read+s.to_write+s.written)
2632 handle_requests_to_failed_array(conf, sh, &s, disks,
2634 if (s.failed > 1 && s.syncing) {
2635 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2636 clear_bit(STRIPE_SYNCING, &sh->state);
2640 /* might be able to return some write requests if the parity block
2641 * is safe, or on a failed drive
2643 dev = &sh->dev[sh->pd_idx];
2645 ((test_bit(R5_Insync, &dev->flags) &&
2646 !test_bit(R5_LOCKED, &dev->flags) &&
2647 test_bit(R5_UPTODATE, &dev->flags)) ||
2648 (s.failed == 1 && s.failed_num == sh->pd_idx)))
2649 handle_completed_write_requests(conf, sh, disks, &return_bi);
2651 /* Now we might consider reading some blocks, either to check/generate
2652 * parity, or to satisfy requests
2653 * or to load a block that is being partially written.
2655 if (s.to_read || s.non_overwrite ||
2656 (s.syncing && (s.uptodate < disks)) || s.expanding)
2657 handle_issuing_new_read_requests5(sh, &s, disks);
2659 /* now to consider writing and what else, if anything should be read */
2661 handle_issuing_new_write_requests5(conf, sh, &s, disks);
2663 /* maybe we need to check and possibly fix the parity for this stripe
2664 * Any reads will already have been scheduled, so we just see if enough data
2667 if (s.syncing && s.locked == 0 &&
2668 !test_bit(STRIPE_INSYNC, &sh->state))
2669 handle_parity_checks5(conf, sh, &s, disks);
2670 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
2671 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2672 clear_bit(STRIPE_SYNCING, &sh->state);
2675 /* If the failed drive is just a ReadError, then we might need to progress
2676 * the repair/check process
2678 if (s.failed == 1 && !conf->mddev->ro &&
2679 test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
2680 && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
2681 && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
2683 dev = &sh->dev[s.failed_num];
2684 if (!test_bit(R5_ReWrite, &dev->flags)) {
2685 set_bit(R5_Wantwrite, &dev->flags);
2686 set_bit(R5_ReWrite, &dev->flags);
2687 set_bit(R5_LOCKED, &dev->flags);
2690 /* let's read it back */
2691 set_bit(R5_Wantread, &dev->flags);
2692 set_bit(R5_LOCKED, &dev->flags);
2697 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
2698 /* Need to write out all blocks after computing parity */
2699 sh->disks = conf->raid_disks;
2700 sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
2701 compute_parity5(sh, RECONSTRUCT_WRITE);
2702 for (i = conf->raid_disks; i--; ) {
2703 set_bit(R5_LOCKED, &sh->dev[i].flags);
2705 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2707 clear_bit(STRIPE_EXPANDING, &sh->state);
2708 } else if (s.expanded) {
2709 clear_bit(STRIPE_EXPAND_READY, &sh->state);
2710 atomic_dec(&conf->reshape_stripes);
2711 wake_up(&conf->wait_for_overlap);
2712 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2715 if (s.expanding && s.locked == 0)
2716 handle_stripe_expansion(conf, sh, NULL);
2719 pending = get_stripe_work(sh);
2721 spin_unlock(&sh->lock);
2724 raid5_run_ops(sh, pending);
2726 return_io(return_bi);
2728 for (i=disks; i-- ;) {
2732 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
2734 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
2739 bi = &sh->dev[i].req;
2743 bi->bi_end_io = raid5_end_write_request;
2745 bi->bi_end_io = raid5_end_read_request;
2748 rdev = rcu_dereference(conf->disks[i].rdev);
2749 if (rdev && test_bit(Faulty, &rdev->flags))
2752 atomic_inc(&rdev->nr_pending);
2756 if (s.syncing || s.expanding || s.expanded)
2757 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
2759 bi->bi_bdev = rdev->bdev;
2760 pr_debug("for %llu schedule op %ld on disc %d\n",
2761 (unsigned long long)sh->sector, bi->bi_rw, i);
2762 atomic_inc(&sh->count);
2763 bi->bi_sector = sh->sector + rdev->data_offset;
2764 bi->bi_flags = 1 << BIO_UPTODATE;
2766 bi->bi_max_vecs = 1;
2768 bi->bi_io_vec = &sh->dev[i].vec;
2769 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
2770 bi->bi_io_vec[0].bv_offset = 0;
2771 bi->bi_size = STRIPE_SIZE;
2774 test_bit(R5_ReWrite, &sh->dev[i].flags))
2775 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2776 generic_make_request(bi);
2779 set_bit(STRIPE_DEGRADED, &sh->state);
2780 pr_debug("skip op %ld on disc %d for sector %llu\n",
2781 bi->bi_rw, i, (unsigned long long)sh->sector);
2782 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2783 set_bit(STRIPE_HANDLE, &sh->state);
2788 static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
2790 raid6_conf_t *conf = sh->raid_conf;
2791 int disks = sh->disks;
2792 struct bio *return_bi = NULL;
2793 int i, pd_idx = sh->pd_idx;
2794 struct stripe_head_state s;
2795 struct r6_state r6s;
2796 struct r5dev *dev, *pdev, *qdev;
2798 r6s.qd_idx = raid6_next_disk(pd_idx, disks);
2799 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
2800 "pd_idx=%d, qd_idx=%d\n",
2801 (unsigned long long)sh->sector, sh->state,
2802 atomic_read(&sh->count), pd_idx, r6s.qd_idx);
2803 memset(&s, 0, sizeof(s));
2805 spin_lock(&sh->lock);
2806 clear_bit(STRIPE_HANDLE, &sh->state);
2807 clear_bit(STRIPE_DELAYED, &sh->state);
2809 s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
2810 s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
2811 s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
2812 /* Now to look around and see what can be done */
2815 for (i=disks; i--; ) {
2818 clear_bit(R5_Insync, &dev->flags);
2820 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
2821 i, dev->flags, dev->toread, dev->towrite, dev->written);
2822 /* maybe we can reply to a read */
2823 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
2824 struct bio *rbi, *rbi2;
2825 pr_debug("Return read for disc %d\n", i);
2826 spin_lock_irq(&conf->device_lock);
2829 if (test_and_clear_bit(R5_Overlap, &dev->flags))
2830 wake_up(&conf->wait_for_overlap);
2831 spin_unlock_irq(&conf->device_lock);
2832 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2833 copy_data(0, rbi, dev->page, dev->sector);
2834 rbi2 = r5_next_bio(rbi, dev->sector);
2835 spin_lock_irq(&conf->device_lock);
2836 if (--rbi->bi_phys_segments == 0) {
2837 rbi->bi_next = return_bi;
2840 spin_unlock_irq(&conf->device_lock);
2845 /* now count some things */
2846 if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
2847 if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
2854 if (!test_bit(R5_OVERWRITE, &dev->flags))
2859 rdev = rcu_dereference(conf->disks[i].rdev);
2860 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
2861 /* The ReadError flag will just be confusing now */
2862 clear_bit(R5_ReadError, &dev->flags);
2863 clear_bit(R5_ReWrite, &dev->flags);
2865 if (!rdev || !test_bit(In_sync, &rdev->flags)
2866 || test_bit(R5_ReadError, &dev->flags)) {
2868 r6s.failed_num[s.failed] = i;
2871 set_bit(R5_Insync, &dev->flags);
2874 pr_debug("locked=%d uptodate=%d to_read=%d"
2875 " to_write=%d failed=%d failed_num=%d,%d\n",
2876 s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
2877 r6s.failed_num[0], r6s.failed_num[1]);
2878 /* check if the array has lost >2 devices and, if so, some requests
2879 * might need to be failed
2881 if (s.failed > 2 && s.to_read+s.to_write+s.written)
2882 handle_requests_to_failed_array(conf, sh, &s, disks,
2884 if (s.failed > 2 && s.syncing) {
2885 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2886 clear_bit(STRIPE_SYNCING, &sh->state);
2891 * might be able to return some write requests if the parity blocks
2892 * are safe, or on a failed drive
2894 pdev = &sh->dev[pd_idx];
2895 r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
2896 || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
2897 qdev = &sh->dev[r6s.qd_idx];
2898 r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == r6s.qd_idx)
2899 || (s.failed >= 2 && r6s.failed_num[1] == r6s.qd_idx);
2902 ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
2903 && !test_bit(R5_LOCKED, &pdev->flags)
2904 && test_bit(R5_UPTODATE, &pdev->flags)))) &&
2905 ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
2906 && !test_bit(R5_LOCKED, &qdev->flags)
2907 && test_bit(R5_UPTODATE, &qdev->flags)))))
2908 handle_completed_write_requests(conf, sh, disks, &return_bi);
2910 /* Now we might consider reading some blocks, either to check/generate
2911 * parity, or to satisfy requests
2912 * or to load a block that is being partially written.
2914 if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
2915 (s.syncing && (s.uptodate < disks)) || s.expanding)
2916 handle_issuing_new_read_requests6(sh, &s, &r6s, disks);
2918 /* now to consider writing and what else, if anything should be read */
2920 handle_issuing_new_write_requests6(conf, sh, &s, &r6s, disks);
2922 /* maybe we need to check and possibly fix the parity for this stripe
2923 * Any reads will already have been scheduled, so we just see if enough
2926 if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
2927 handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
2929 if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
2930 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2931 clear_bit(STRIPE_SYNCING, &sh->state);
2934 /* If the failed drives are just a ReadError, then we might need
2935 * to progress the repair/check process
2937 if (s.failed <= 2 && !conf->mddev->ro)
2938 for (i = 0; i < s.failed; i++) {
2939 dev = &sh->dev[r6s.failed_num[i]];
2940 if (test_bit(R5_ReadError, &dev->flags)
2941 && !test_bit(R5_LOCKED, &dev->flags)
2942 && test_bit(R5_UPTODATE, &dev->flags)
2944 if (!test_bit(R5_ReWrite, &dev->flags)) {
2945 set_bit(R5_Wantwrite, &dev->flags);
2946 set_bit(R5_ReWrite, &dev->flags);
2947 set_bit(R5_LOCKED, &dev->flags);
2949 /* let's read it back */
2950 set_bit(R5_Wantread, &dev->flags);
2951 set_bit(R5_LOCKED, &dev->flags);
2956 if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
2957 /* Need to write out all blocks after computing P&Q */
2958 sh->disks = conf->raid_disks;
2959 sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
2961 compute_parity6(sh, RECONSTRUCT_WRITE);
2962 for (i = conf->raid_disks ; i-- ; ) {
2963 set_bit(R5_LOCKED, &sh->dev[i].flags);
2965 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2967 clear_bit(STRIPE_EXPANDING, &sh->state);
2968 } else if (s.expanded) {
2969 clear_bit(STRIPE_EXPAND_READY, &sh->state);
2970 atomic_dec(&conf->reshape_stripes);
2971 wake_up(&conf->wait_for_overlap);
2972 md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
2975 if (s.expanding && s.locked == 0)
2976 handle_stripe_expansion(conf, sh, &r6s);
2978 spin_unlock(&sh->lock);
2980 return_io(return_bi);
2982 for (i=disks; i-- ;) {
2986 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
2988 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
2993 bi = &sh->dev[i].req;
2997 bi->bi_end_io = raid5_end_write_request;
2999 bi->bi_end_io = raid5_end_read_request;
3002 rdev = rcu_dereference(conf->disks[i].rdev);
3003 if (rdev && test_bit(Faulty, &rdev->flags))
3006 atomic_inc(&rdev->nr_pending);
3010 if (s.syncing || s.expanding || s.expanded)
3011 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
3013 bi->bi_bdev = rdev->bdev;
3014 pr_debug("for %llu schedule op %ld on disc %d\n",
3015 (unsigned long long)sh->sector, bi->bi_rw, i);
3016 atomic_inc(&sh->count);
3017 bi->bi_sector = sh->sector + rdev->data_offset;
3018 bi->bi_flags = 1 << BIO_UPTODATE;
3020 bi->bi_max_vecs = 1;
3022 bi->bi_io_vec = &sh->dev[i].vec;
3023 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
3024 bi->bi_io_vec[0].bv_offset = 0;
3025 bi->bi_size = STRIPE_SIZE;
3028 test_bit(R5_ReWrite, &sh->dev[i].flags))
3029 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
3030 generic_make_request(bi);
3033 set_bit(STRIPE_DEGRADED, &sh->state);
3034 pr_debug("skip op %ld on disc %d for sector %llu\n",
3035 bi->bi_rw, i, (unsigned long long)sh->sector);
3036 clear_bit(R5_LOCKED, &sh->dev[i].flags);
3037 set_bit(STRIPE_HANDLE, &sh->state);
3042 static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
3044 if (sh->raid_conf->level == 6)
3045 handle_stripe6(sh, tmp_page);
3052 static void raid5_activate_delayed(raid5_conf_t *conf)
3054 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
3055 while (!list_empty(&conf->delayed_list)) {
3056 struct list_head *l = conf->delayed_list.next;
3057 struct stripe_head *sh;
3058 sh = list_entry(l, struct stripe_head, lru);
3060 clear_bit(STRIPE_DELAYED, &sh->state);
3061 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
3062 atomic_inc(&conf->preread_active_stripes);
3063 list_add_tail(&sh->lru, &conf->handle_list);
3068 static void activate_bit_delay(raid5_conf_t *conf)
3070 /* device_lock is held */
3071 struct list_head head;
3072 list_add(&head, &conf->bitmap_list);
3073 list_del_init(&conf->bitmap_list);
3074 while (!list_empty(&head)) {
3075 struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
3076 list_del_init(&sh->lru);
3077 atomic_inc(&sh->count);
3078 __release_stripe(conf, sh);
3082 static void unplug_slaves(mddev_t *mddev)
3084 raid5_conf_t *conf = mddev_to_conf(mddev);
3088 for (i=0; i<mddev->raid_disks; i++) {
3089 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
3090 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
3091 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
3093 atomic_inc(&rdev->nr_pending);
3096 if (r_queue->unplug_fn)
3097 r_queue->unplug_fn(r_queue);
3099 rdev_dec_pending(rdev, mddev);
3106 static void raid5_unplug_device(request_queue_t *q)
3108 mddev_t *mddev = q->queuedata;
3109 raid5_conf_t *conf = mddev_to_conf(mddev);
3110 unsigned long flags;
3112 spin_lock_irqsave(&conf->device_lock, flags);
3114 if (blk_remove_plug(q)) {
3116 raid5_activate_delayed(conf);
3118 md_wakeup_thread(mddev->thread);
3120 spin_unlock_irqrestore(&conf->device_lock, flags);
3122 unplug_slaves(mddev);
3125 static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk,
3126 sector_t *error_sector)
3128 mddev_t *mddev = q->queuedata;
3129 raid5_conf_t *conf = mddev_to_conf(mddev);
3133 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
3134 mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
3135 if (rdev && !test_bit(Faulty, &rdev->flags)) {
3136 struct block_device *bdev = rdev->bdev;
3137 request_queue_t *r_queue = bdev_get_queue(bdev);
3139 if (!r_queue->issue_flush_fn)
3142 atomic_inc(&rdev->nr_pending);
3144 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
3146 rdev_dec_pending(rdev, mddev);
3155 static int raid5_congested(void *data, int bits)
3157 mddev_t *mddev = data;
3158 raid5_conf_t *conf = mddev_to_conf(mddev);
3160 /* No difference between reads and writes. Just check
3161 * how busy the stripe_cache is
3163 if (conf->inactive_blocked)
3167 if (list_empty_careful(&conf->inactive_list))
3173 /* We want read requests to align with chunks where possible,
3174 * but write requests don't need to.
3176 static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
3178 mddev_t *mddev = q->queuedata;
3179 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3181 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3182 unsigned int bio_sectors = bio->bi_size >> 9;
3184 if (bio_data_dir(bio) == WRITE)
3185 return biovec->bv_len; /* always allow writes to be mergeable */
3187 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
3188 if (max < 0) max = 0;
3189 if (max <= biovec->bv_len && bio_sectors == 0)
3190 return biovec->bv_len;
3196 static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
3198 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
3199 unsigned int chunk_sectors = mddev->chunk_size >> 9;
3200 unsigned int bio_sectors = bio->bi_size >> 9;
3202 return chunk_sectors >=
3203 ((sector & (chunk_sectors - 1)) + bio_sectors);
3207 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3208 * later sampled by raid5d.
3210 static void add_bio_to_retry(struct bio *bi,raid5_conf_t *conf)
3212 unsigned long flags;
3214 spin_lock_irqsave(&conf->device_lock, flags);
3216 bi->bi_next = conf->retry_read_aligned_list;
3217 conf->retry_read_aligned_list = bi;
3219 spin_unlock_irqrestore(&conf->device_lock, flags);
3220 md_wakeup_thread(conf->mddev->thread);
3224 static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
3228 bi = conf->retry_read_aligned;
3230 conf->retry_read_aligned = NULL;
3233 bi = conf->retry_read_aligned_list;
3235 conf->retry_read_aligned_list = bi->bi_next;
3237 bi->bi_phys_segments = 1; /* biased count of active stripes */
3238 bi->bi_hw_segments = 0; /* count of processed stripes */
3246 * The "raid5_align_endio" should check if the read succeeded and if it
3247 * did, call bio_endio on the original bio (having bio_put the new bio
3249 * If the read failed..
3251 static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error)
3253 struct bio* raid_bi = bi->bi_private;
3256 int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
3263 mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
3264 conf = mddev_to_conf(mddev);
3265 rdev = (void*)raid_bi->bi_next;
3266 raid_bi->bi_next = NULL;
3268 rdev_dec_pending(rdev, conf->mddev);
3270 if (!error && uptodate) {
3271 bio_endio(raid_bi, bytes, 0);
3272 if (atomic_dec_and_test(&conf->active_aligned_reads))
3273 wake_up(&conf->wait_for_stripe);
3278 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3280 add_bio_to_retry(raid_bi, conf);
3284 static int bio_fits_rdev(struct bio *bi)
3286 request_queue_t *q = bdev_get_queue(bi->bi_bdev);
3288 if ((bi->bi_size>>9) > q->max_sectors)
3290 blk_recount_segments(q, bi);
3291 if (bi->bi_phys_segments > q->max_phys_segments ||
3292 bi->bi_hw_segments > q->max_hw_segments)
3295 if (q->merge_bvec_fn)
3296 /* it's too hard to apply the merge_bvec_fn at this stage,
3305 static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
3307 mddev_t *mddev = q->queuedata;
3308 raid5_conf_t *conf = mddev_to_conf(mddev);
3309 const unsigned int raid_disks = conf->raid_disks;
3310 const unsigned int data_disks = raid_disks - conf->max_degraded;
3311 unsigned int dd_idx, pd_idx;
3312 struct bio* align_bi;
3315 if (!in_chunk_boundary(mddev, raid_bio)) {
3316 pr_debug("chunk_aligned_read : non aligned\n");
3320 * use bio_clone to make a copy of the bio
3322 align_bi = bio_clone(raid_bio, GFP_NOIO);
3326 * set bi_end_io to a new function, and set bi_private to the
3329 align_bi->bi_end_io = raid5_align_endio;
3330 align_bi->bi_private = raid_bio;
3334 align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector,
3342 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
3343 if (rdev && test_bit(In_sync, &rdev->flags)) {
3344 atomic_inc(&rdev->nr_pending);
3346 raid_bio->bi_next = (void*)rdev;
3347 align_bi->bi_bdev = rdev->bdev;
3348 align_bi->bi_flags &= ~(1 << BIO_SEG_VALID);
3349 align_bi->bi_sector += rdev->data_offset;
3351 if (!bio_fits_rdev(align_bi)) {
3352 /* too big in some way */
3354 rdev_dec_pending(rdev, mddev);
3358 spin_lock_irq(&conf->device_lock);
3359 wait_event_lock_irq(conf->wait_for_stripe,
3361 conf->device_lock, /* nothing */);
3362 atomic_inc(&conf->active_aligned_reads);
3363 spin_unlock_irq(&conf->device_lock);
3365 generic_make_request(align_bi);
3375 static int make_request(request_queue_t *q, struct bio * bi)
3377 mddev_t *mddev = q->queuedata;
3378 raid5_conf_t *conf = mddev_to_conf(mddev);
3379 unsigned int dd_idx, pd_idx;
3380 sector_t new_sector;
3381 sector_t logical_sector, last_sector;
3382 struct stripe_head *sh;
3383 const int rw = bio_data_dir(bi);
3386 if (unlikely(bio_barrier(bi))) {
3387 bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
3391 md_write_start(mddev, bi);
3393 disk_stat_inc(mddev->gendisk, ios[rw]);
3394 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
3397 mddev->reshape_position == MaxSector &&
3398 chunk_aligned_read(q,bi))
3401 logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3402 last_sector = bi->bi_sector + (bi->bi_size>>9);
3404 bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
3406 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
3408 int disks, data_disks;
3411 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
3412 if (likely(conf->expand_progress == MaxSector))
3413 disks = conf->raid_disks;
3415 /* spinlock is needed as expand_progress may be
3416 * 64bit on a 32bit platform, and so it might be
3417 * possible to see a half-updated value
3418 * Ofcourse expand_progress could change after
3419 * the lock is dropped, so once we get a reference
3420 * to the stripe that we think it is, we will have
3423 spin_lock_irq(&conf->device_lock);
3424 disks = conf->raid_disks;
3425 if (logical_sector >= conf->expand_progress)
3426 disks = conf->previous_raid_disks;
3428 if (logical_sector >= conf->expand_lo) {
3429 spin_unlock_irq(&conf->device_lock);
3434 spin_unlock_irq(&conf->device_lock);
3436 data_disks = disks - conf->max_degraded;
3438 new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
3439 &dd_idx, &pd_idx, conf);
3440 pr_debug("raid5: make_request, sector %llu logical %llu\n",
3441 (unsigned long long)new_sector,
3442 (unsigned long long)logical_sector);
3444 sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
3446 if (unlikely(conf->expand_progress != MaxSector)) {
3447 /* expansion might have moved on while waiting for a
3448 * stripe, so we must do the range check again.
3449 * Expansion could still move past after this
3450 * test, but as we are holding a reference to
3451 * 'sh', we know that if that happens,
3452 * STRIPE_EXPANDING will get set and the expansion
3453 * won't proceed until we finish with the stripe.
3456 spin_lock_irq(&conf->device_lock);
3457 if (logical_sector < conf->expand_progress &&
3458 disks == conf->previous_raid_disks)
3459 /* mismatch, need to try again */
3461 spin_unlock_irq(&conf->device_lock);
3467 /* FIXME what if we get a false positive because these
3468 * are being updated.
3470 if (logical_sector >= mddev->suspend_lo &&
3471 logical_sector < mddev->suspend_hi) {
3477 if (test_bit(STRIPE_EXPANDING, &sh->state) ||
3478 !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
3479 /* Stripe is busy expanding or
3480 * add failed due to overlap. Flush everything
3483 raid5_unplug_device(mddev->queue);
3488 finish_wait(&conf->wait_for_overlap, &w);
3489 handle_stripe(sh, NULL);
3492 /* cannot get stripe for read-ahead, just give-up */
3493 clear_bit(BIO_UPTODATE, &bi->bi_flags);
3494 finish_wait(&conf->wait_for_overlap, &w);
3499 spin_lock_irq(&conf->device_lock);
3500 remaining = --bi->bi_phys_segments;
3501 spin_unlock_irq(&conf->device_lock);
3502 if (remaining == 0) {
3503 int bytes = bi->bi_size;
3506 md_write_end(mddev);
3508 bi->bi_end_io(bi, bytes,
3509 test_bit(BIO_UPTODATE, &bi->bi_flags)
3515 static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
3517 /* reshaping is quite different to recovery/resync so it is
3518 * handled quite separately ... here.
3520 * On each call to sync_request, we gather one chunk worth of
3521 * destination stripes and flag them as expanding.
3522 * Then we find all the source stripes and request reads.
3523 * As the reads complete, handle_stripe will copy the data
3524 * into the destination stripe and release that stripe.
3526 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3527 struct stripe_head *sh;
3529 sector_t first_sector, last_sector;
3530 int raid_disks = conf->previous_raid_disks;
3531 int data_disks = raid_disks - conf->max_degraded;
3532 int new_data_disks = conf->raid_disks - conf->max_degraded;
3535 sector_t writepos, safepos, gap;
3537 if (sector_nr == 0 &&
3538 conf->expand_progress != 0) {
3539 /* restarting in the middle, skip the initial sectors */
3540 sector_nr = conf->expand_progress;
3541 sector_div(sector_nr, new_data_disks);
3546 /* we update the metadata when there is more than 3Meg
3547 * in the block range (that is rather arbitrary, should
3548 * probably be time based) or when the data about to be
3549 * copied would over-write the source of the data at
3550 * the front of the range.
3551 * i.e. one new_stripe forward from expand_progress new_maps
3552 * to after where expand_lo old_maps to
3554 writepos = conf->expand_progress +
3555 conf->chunk_size/512*(new_data_disks);
3556 sector_div(writepos, new_data_disks);
3557 safepos = conf->expand_lo;
3558 sector_div(safepos, data_disks);
3559 gap = conf->expand_progress - conf->expand_lo;
3561 if (writepos >= safepos ||
3562 gap > (new_data_disks)*3000*2 /*3Meg*/) {
3563 /* Cannot proceed until we've updated the superblock... */
3564 wait_event(conf->wait_for_overlap,
3565 atomic_read(&conf->reshape_stripes)==0);
3566 mddev->reshape_position = conf->expand_progress;
3567 set_bit(MD_CHANGE_DEVS, &mddev->flags);
3568 md_wakeup_thread(mddev->thread);
3569 wait_event(mddev->sb_wait, mddev->flags == 0 ||
3570 kthread_should_stop());
3571 spin_lock_irq(&conf->device_lock);
3572 conf->expand_lo = mddev->reshape_position;
3573 spin_unlock_irq(&conf->device_lock);
3574 wake_up(&conf->wait_for_overlap);
3577 for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
3580 pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
3581 sh = get_active_stripe(conf, sector_nr+i,
3582 conf->raid_disks, pd_idx, 0);
3583 set_bit(STRIPE_EXPANDING, &sh->state);
3584 atomic_inc(&conf->reshape_stripes);
3585 /* If any of this stripe is beyond the end of the old
3586 * array, then we need to zero those blocks
3588 for (j=sh->disks; j--;) {
3590 if (j == sh->pd_idx)
3592 if (conf->level == 6 &&
3593 j == raid6_next_disk(sh->pd_idx, sh->disks))
3595 s = compute_blocknr(sh, j);
3596 if (s < (mddev->array_size<<1)) {
3600 memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
3601 set_bit(R5_Expanded, &sh->dev[j].flags);
3602 set_bit(R5_UPTODATE, &sh->dev[j].flags);
3605 set_bit(STRIPE_EXPAND_READY, &sh->state);
3606 set_bit(STRIPE_HANDLE, &sh->state);
3610 spin_lock_irq(&conf->device_lock);
3611 conf->expand_progress = (sector_nr + i) * new_data_disks;
3612 spin_unlock_irq(&conf->device_lock);
3613 /* Ok, those stripe are ready. We can start scheduling
3614 * reads on the source stripes.
3615 * The source stripes are determined by mapping the first and last
3616 * block on the destination stripes.
3619 raid5_compute_sector(sector_nr*(new_data_disks),
3620 raid_disks, data_disks,
3621 &dd_idx, &pd_idx, conf);
3623 raid5_compute_sector((sector_nr+conf->chunk_size/512)
3624 *(new_data_disks) -1,
3625 raid_disks, data_disks,
3626 &dd_idx, &pd_idx, conf);
3627 if (last_sector >= (mddev->size<<1))
3628 last_sector = (mddev->size<<1)-1;
3629 while (first_sector <= last_sector) {
3630 pd_idx = stripe_to_pdidx(first_sector, conf,
3631 conf->previous_raid_disks);
3632 sh = get_active_stripe(conf, first_sector,
3633 conf->previous_raid_disks, pd_idx, 0);
3634 set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
3635 set_bit(STRIPE_HANDLE, &sh->state);
3637 first_sector += STRIPE_SECTORS;
3639 return conf->chunk_size>>9;
3642 /* FIXME go_faster isn't used */
3643 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
3645 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
3646 struct stripe_head *sh;
3648 int raid_disks = conf->raid_disks;
3649 sector_t max_sector = mddev->size << 1;
3651 int still_degraded = 0;
3654 if (sector_nr >= max_sector) {
3655 /* just being told to finish up .. nothing much to do */
3656 unplug_slaves(mddev);
3657 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
3662 if (mddev->curr_resync < max_sector) /* aborted */
3663 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
3665 else /* completed sync */
3667 bitmap_close_sync(mddev->bitmap);
3672 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3673 return reshape_request(mddev, sector_nr, skipped);
3675 /* if there is too many failed drives and we are trying
3676 * to resync, then assert that we are finished, because there is
3677 * nothing we can do.
3679 if (mddev->degraded >= conf->max_degraded &&
3680 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3681 sector_t rv = (mddev->size << 1) - sector_nr;
3685 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
3686 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
3687 !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
3688 /* we can skip this block, and probably more */
3689 sync_blocks /= STRIPE_SECTORS;
3691 return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
3694 pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
3695 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
3697 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
3698 /* make sure we don't swamp the stripe cache if someone else
3699 * is trying to get access
3701 schedule_timeout_uninterruptible(1);
3703 /* Need to check if array will still be degraded after recovery/resync
3704 * We don't need to check the 'failed' flag as when that gets set,
3707 for (i=0; i<mddev->raid_disks; i++)
3708 if (conf->disks[i].rdev == NULL)
3711 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
3713 spin_lock(&sh->lock);
3714 set_bit(STRIPE_SYNCING, &sh->state);
3715 clear_bit(STRIPE_INSYNC, &sh->state);
3716 spin_unlock(&sh->lock);
3718 handle_stripe(sh, NULL);
3721 return STRIPE_SECTORS;
3724 static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
3726 /* We may not be able to submit a whole bio at once as there
3727 * may not be enough stripe_heads available.
3728 * We cannot pre-allocate enough stripe_heads as we may need
3729 * more than exist in the cache (if we allow ever large chunks).
3730 * So we do one stripe head at a time and record in
3731 * ->bi_hw_segments how many have been done.
3733 * We *know* that this entire raid_bio is in one chunk, so
3734 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3736 struct stripe_head *sh;
3738 sector_t sector, logical_sector, last_sector;
3743 logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
3744 sector = raid5_compute_sector( logical_sector,
3746 conf->raid_disks - conf->max_degraded,
3750 last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
3752 for (; logical_sector < last_sector;
3753 logical_sector += STRIPE_SECTORS,
3754 sector += STRIPE_SECTORS,
3757 if (scnt < raid_bio->bi_hw_segments)
3758 /* already done this stripe */
3761 sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1);
3764 /* failed to get a stripe - must wait */
3765 raid_bio->bi_hw_segments = scnt;
3766 conf->retry_read_aligned = raid_bio;
3770 set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
3771 if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
3773 raid_bio->bi_hw_segments = scnt;
3774 conf->retry_read_aligned = raid_bio;
3778 handle_stripe(sh, NULL);
3782 spin_lock_irq(&conf->device_lock);
3783 remaining = --raid_bio->bi_phys_segments;
3784 spin_unlock_irq(&conf->device_lock);
3785 if (remaining == 0) {
3786 int bytes = raid_bio->bi_size;
3788 raid_bio->bi_size = 0;
3789 raid_bio->bi_end_io(raid_bio, bytes,
3790 test_bit(BIO_UPTODATE, &raid_bio->bi_flags)
3793 if (atomic_dec_and_test(&conf->active_aligned_reads))
3794 wake_up(&conf->wait_for_stripe);
3801 * This is our raid5 kernel thread.
3803 * We scan the hash table for stripes which can be handled now.
3804 * During the scan, completed stripes are saved for us by the interrupt
3805 * handler, so that they will not have to wait for our next wakeup.
3807 static void raid5d (mddev_t *mddev)
3809 struct stripe_head *sh;
3810 raid5_conf_t *conf = mddev_to_conf(mddev);
3813 pr_debug("+++ raid5d active\n");
3815 md_check_recovery(mddev);
3818 spin_lock_irq(&conf->device_lock);
3820 struct list_head *first;
3823 if (conf->seq_flush != conf->seq_write) {
3824 int seq = conf->seq_flush;
3825 spin_unlock_irq(&conf->device_lock);
3826 bitmap_unplug(mddev->bitmap);
3827 spin_lock_irq(&conf->device_lock);
3828 conf->seq_write = seq;
3829 activate_bit_delay(conf);
3832 if (list_empty(&conf->handle_list) &&
3833 atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD &&
3834 !blk_queue_plugged(mddev->queue) &&
3835 !list_empty(&conf->delayed_list))
3836 raid5_activate_delayed(conf);
3838 while ((bio = remove_bio_from_retry(conf))) {
3840 spin_unlock_irq(&conf->device_lock);
3841 ok = retry_aligned_read(conf, bio);
3842 spin_lock_irq(&conf->device_lock);
3848 if (list_empty(&conf->handle_list)) {
3849 async_tx_issue_pending_all();
3853 first = conf->handle_list.next;
3854 sh = list_entry(first, struct stripe_head, lru);
3856 list_del_init(first);
3857 atomic_inc(&sh->count);
3858 BUG_ON(atomic_read(&sh->count)!= 1);
3859 spin_unlock_irq(&conf->device_lock);
3862 handle_stripe(sh, conf->spare_page);
3865 spin_lock_irq(&conf->device_lock);
3867 pr_debug("%d stripes handled\n", handled);
3869 spin_unlock_irq(&conf->device_lock);
3871 unplug_slaves(mddev);
3873 pr_debug("--- raid5d inactive\n");
3877 raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
3879 raid5_conf_t *conf = mddev_to_conf(mddev);
3881 return sprintf(page, "%d\n", conf->max_nr_stripes);
3887 raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
3889 raid5_conf_t *conf = mddev_to_conf(mddev);
3892 if (len >= PAGE_SIZE)
3897 new = simple_strtoul(page, &end, 10);
3898 if (!*page || (*end && *end != '\n') )
3900 if (new <= 16 || new > 32768)
3902 while (new < conf->max_nr_stripes) {
3903 if (drop_one_stripe(conf))
3904 conf->max_nr_stripes--;
3908 md_allow_write(mddev);
3909 while (new > conf->max_nr_stripes) {
3910 if (grow_one_stripe(conf))
3911 conf->max_nr_stripes++;
3917 static struct md_sysfs_entry
3918 raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
3919 raid5_show_stripe_cache_size,
3920 raid5_store_stripe_cache_size);
3923 stripe_cache_active_show(mddev_t *mddev, char *page)
3925 raid5_conf_t *conf = mddev_to_conf(mddev);
3927 return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
3932 static struct md_sysfs_entry
3933 raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
3935 static struct attribute *raid5_attrs[] = {
3936 &raid5_stripecache_size.attr,
3937 &raid5_stripecache_active.attr,
3940 static struct attribute_group raid5_attrs_group = {
3942 .attrs = raid5_attrs,
3945 static int run(mddev_t *mddev)
3948 int raid_disk, memory;
3950 struct disk_info *disk;
3951 struct list_head *tmp;
3952 int working_disks = 0;
3954 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
3955 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
3956 mdname(mddev), mddev->level);
3960 if (mddev->reshape_position != MaxSector) {
3961 /* Check that we can continue the reshape.
3962 * Currently only disks can change, it must
3963 * increase, and we must be past the point where
3964 * a stripe over-writes itself
3966 sector_t here_new, here_old;
3968 int max_degraded = (mddev->level == 5 ? 1 : 2);
3970 if (mddev->new_level != mddev->level ||
3971 mddev->new_layout != mddev->layout ||
3972 mddev->new_chunk != mddev->chunk_size) {
3973 printk(KERN_ERR "raid5: %s: unsupported reshape "
3974 "required - aborting.\n",
3978 if (mddev->delta_disks <= 0) {
3979 printk(KERN_ERR "raid5: %s: unsupported reshape "
3980 "(reduce disks) required - aborting.\n",
3984 old_disks = mddev->raid_disks - mddev->delta_disks;
3985 /* reshape_position must be on a new-stripe boundary, and one
3986 * further up in new geometry must map after here in old
3989 here_new = mddev->reshape_position;
3990 if (sector_div(here_new, (mddev->chunk_size>>9)*
3991 (mddev->raid_disks - max_degraded))) {
3992 printk(KERN_ERR "raid5: reshape_position not "
3993 "on a stripe boundary\n");
3996 /* here_new is the stripe we will write to */
3997 here_old = mddev->reshape_position;
3998 sector_div(here_old, (mddev->chunk_size>>9)*
3999 (old_disks-max_degraded));
4000 /* here_old is the first stripe that we might need to read
4002 if (here_new >= here_old) {
4003 /* Reading from the same stripe as writing to - bad */
4004 printk(KERN_ERR "raid5: reshape_position too early for "
4005 "auto-recovery - aborting.\n");
4008 printk(KERN_INFO "raid5: reshape will continue\n");
4009 /* OK, we should be able to continue; */
4013 mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
4014 if ((conf = mddev->private) == NULL)
4016 if (mddev->reshape_position == MaxSector) {
4017 conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
4019 conf->raid_disks = mddev->raid_disks;
4020 conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
4023 conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
4028 conf->mddev = mddev;
4030 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
4033 if (mddev->level == 6) {
4034 conf->spare_page = alloc_page(GFP_KERNEL);
4035 if (!conf->spare_page)
4038 spin_lock_init(&conf->device_lock);
4039 init_waitqueue_head(&conf->wait_for_stripe);
4040 init_waitqueue_head(&conf->wait_for_overlap);
4041 INIT_LIST_HEAD(&conf->handle_list);
4042 INIT_LIST_HEAD(&conf->delayed_list);
4043 INIT_LIST_HEAD(&conf->bitmap_list);
4044 INIT_LIST_HEAD(&conf->inactive_list);
4045 atomic_set(&conf->active_stripes, 0);
4046 atomic_set(&conf->preread_active_stripes, 0);
4047 atomic_set(&conf->active_aligned_reads, 0);
4049 pr_debug("raid5: run(%s) called.\n", mdname(mddev));
4051 ITERATE_RDEV(mddev,rdev,tmp) {
4052 raid_disk = rdev->raid_disk;
4053 if (raid_disk >= conf->raid_disks
4056 disk = conf->disks + raid_disk;
4060 if (test_bit(In_sync, &rdev->flags)) {
4061 char b[BDEVNAME_SIZE];
4062 printk(KERN_INFO "raid5: device %s operational as raid"
4063 " disk %d\n", bdevname(rdev->bdev,b),
4070 * 0 for a fully functional array, 1 or 2 for a degraded array.
4072 mddev->degraded = conf->raid_disks - working_disks;
4073 conf->mddev = mddev;
4074 conf->chunk_size = mddev->chunk_size;
4075 conf->level = mddev->level;
4076 if (conf->level == 6)
4077 conf->max_degraded = 2;
4079 conf->max_degraded = 1;
4080 conf->algorithm = mddev->layout;
4081 conf->max_nr_stripes = NR_STRIPES;
4082 conf->expand_progress = mddev->reshape_position;
4084 /* device size must be a multiple of chunk size */
4085 mddev->size &= ~(mddev->chunk_size/1024 -1);
4086 mddev->resync_max_sectors = mddev->size << 1;
4088 if (conf->level == 6 && conf->raid_disks < 4) {
4089 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
4090 mdname(mddev), conf->raid_disks);
4093 if (!conf->chunk_size || conf->chunk_size % 4) {
4094 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
4095 conf->chunk_size, mdname(mddev));
4098 if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
4100 "raid5: unsupported parity algorithm %d for %s\n",
4101 conf->algorithm, mdname(mddev));
4104 if (mddev->degraded > conf->max_degraded) {
4105 printk(KERN_ERR "raid5: not enough operational devices for %s"
4106 " (%d/%d failed)\n",
4107 mdname(mddev), mddev->degraded, conf->raid_disks);
4111 if (mddev->degraded > 0 &&
4112 mddev->recovery_cp != MaxSector) {
4113 if (mddev->ok_start_degraded)
4115 "raid5: starting dirty degraded array: %s"
4116 "- data corruption possible.\n",
4120 "raid5: cannot start dirty degraded array for %s\n",
4127 mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
4128 if (!mddev->thread) {
4130 "raid5: couldn't allocate thread for %s\n",
4135 memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
4136 conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
4137 if (grow_stripes(conf, conf->max_nr_stripes)) {
4139 "raid5: couldn't allocate %dkB for buffers\n", memory);
4140 shrink_stripes(conf);
4141 md_unregister_thread(mddev->thread);
4144 printk(KERN_INFO "raid5: allocated %dkB for %s\n",
4145 memory, mdname(mddev));
4147 if (mddev->degraded == 0)
4148 printk("raid5: raid level %d set %s active with %d out of %d"
4149 " devices, algorithm %d\n", conf->level, mdname(mddev),
4150 mddev->raid_disks-mddev->degraded, mddev->raid_disks,
4153 printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
4154 " out of %d devices, algorithm %d\n", conf->level,
4155 mdname(mddev), mddev->raid_disks - mddev->degraded,
4156 mddev->raid_disks, conf->algorithm);
4158 print_raid5_conf(conf);
4160 if (conf->expand_progress != MaxSector) {
4161 printk("...ok start reshape thread\n");
4162 conf->expand_lo = conf->expand_progress;
4163 atomic_set(&conf->reshape_stripes, 0);
4164 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4165 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4166 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4167 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4168 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4172 /* read-ahead size must cover two whole stripes, which is
4173 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4176 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4177 int stripe = data_disks *
4178 (mddev->chunk_size / PAGE_SIZE);
4179 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4180 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4183 /* Ok, everything is just fine now */
4184 if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
4186 "raid5: failed to create sysfs attributes for %s\n",
4189 mddev->queue->unplug_fn = raid5_unplug_device;
4190 mddev->queue->issue_flush_fn = raid5_issue_flush;
4191 mddev->queue->backing_dev_info.congested_data = mddev;
4192 mddev->queue->backing_dev_info.congested_fn = raid5_congested;
4194 mddev->array_size = mddev->size * (conf->previous_raid_disks -
4195 conf->max_degraded);
4197 blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
4202 print_raid5_conf(conf);
4203 safe_put_page(conf->spare_page);
4205 kfree(conf->stripe_hashtbl);
4208 mddev->private = NULL;
4209 printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
4215 static int stop(mddev_t *mddev)
4217 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4219 md_unregister_thread(mddev->thread);
4220 mddev->thread = NULL;
4221 shrink_stripes(conf);
4222 kfree(conf->stripe_hashtbl);
4223 mddev->queue->backing_dev_info.congested_fn = NULL;
4224 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
4225 sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
4228 mddev->private = NULL;
4233 static void print_sh (struct seq_file *seq, struct stripe_head *sh)
4237 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
4238 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
4239 seq_printf(seq, "sh %llu, count %d.\n",
4240 (unsigned long long)sh->sector, atomic_read(&sh->count));
4241 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
4242 for (i = 0; i < sh->disks; i++) {
4243 seq_printf(seq, "(cache%d: %p %ld) ",
4244 i, sh->dev[i].page, sh->dev[i].flags);
4246 seq_printf(seq, "\n");
4249 static void printall (struct seq_file *seq, raid5_conf_t *conf)
4251 struct stripe_head *sh;
4252 struct hlist_node *hn;
4255 spin_lock_irq(&conf->device_lock);
4256 for (i = 0; i < NR_HASH; i++) {
4257 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
4258 if (sh->raid_conf != conf)
4263 spin_unlock_irq(&conf->device_lock);
4267 static void status (struct seq_file *seq, mddev_t *mddev)
4269 raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
4272 seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
4273 seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
4274 for (i = 0; i < conf->raid_disks; i++)
4275 seq_printf (seq, "%s",
4276 conf->disks[i].rdev &&
4277 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
4278 seq_printf (seq, "]");
4280 seq_printf (seq, "\n");
4281 printall(seq, conf);
4285 static void print_raid5_conf (raid5_conf_t *conf)
4288 struct disk_info *tmp;
4290 printk("RAID5 conf printout:\n");
4292 printk("(conf==NULL)\n");
4295 printk(" --- rd:%d wd:%d\n", conf->raid_disks,
4296 conf->raid_disks - conf->mddev->degraded);
4298 for (i = 0; i < conf->raid_disks; i++) {
4299 char b[BDEVNAME_SIZE];
4300 tmp = conf->disks + i;
4302 printk(" disk %d, o:%d, dev:%s\n",
4303 i, !test_bit(Faulty, &tmp->rdev->flags),
4304 bdevname(tmp->rdev->bdev,b));
4308 static int raid5_spare_active(mddev_t *mddev)
4311 raid5_conf_t *conf = mddev->private;
4312 struct disk_info *tmp;
4314 for (i = 0; i < conf->raid_disks; i++) {
4315 tmp = conf->disks + i;
4317 && !test_bit(Faulty, &tmp->rdev->flags)
4318 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
4319 unsigned long flags;
4320 spin_lock_irqsave(&conf->device_lock, flags);
4322 spin_unlock_irqrestore(&conf->device_lock, flags);
4325 print_raid5_conf(conf);
4329 static int raid5_remove_disk(mddev_t *mddev, int number)
4331 raid5_conf_t *conf = mddev->private;
4334 struct disk_info *p = conf->disks + number;
4336 print_raid5_conf(conf);
4339 if (test_bit(In_sync, &rdev->flags) ||
4340 atomic_read(&rdev->nr_pending)) {
4346 if (atomic_read(&rdev->nr_pending)) {
4347 /* lost the race, try later */
4354 print_raid5_conf(conf);
4358 static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
4360 raid5_conf_t *conf = mddev->private;
4363 struct disk_info *p;
4365 if (mddev->degraded > conf->max_degraded)
4366 /* no point adding a device */
4370 * find the disk ... but prefer rdev->saved_raid_disk
4373 if (rdev->saved_raid_disk >= 0 &&
4374 conf->disks[rdev->saved_raid_disk].rdev == NULL)
4375 disk = rdev->saved_raid_disk;
4378 for ( ; disk < conf->raid_disks; disk++)
4379 if ((p=conf->disks + disk)->rdev == NULL) {
4380 clear_bit(In_sync, &rdev->flags);
4381 rdev->raid_disk = disk;
4383 if (rdev->saved_raid_disk != disk)
4385 rcu_assign_pointer(p->rdev, rdev);
4388 print_raid5_conf(conf);
4392 static int raid5_resize(mddev_t *mddev, sector_t sectors)
4394 /* no resync is happening, and there is enough space
4395 * on all devices, so we can resize.
4396 * We need to make sure resync covers any new space.
4397 * If the array is shrinking we should possibly wait until
4398 * any io in the removed space completes, but it hardly seems
4401 raid5_conf_t *conf = mddev_to_conf(mddev);
4403 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
4404 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
4405 set_capacity(mddev->gendisk, mddev->array_size << 1);
4407 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
4408 mddev->recovery_cp = mddev->size << 1;
4409 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4411 mddev->size = sectors /2;
4412 mddev->resync_max_sectors = sectors;
4416 #ifdef CONFIG_MD_RAID5_RESHAPE
4417 static int raid5_check_reshape(mddev_t *mddev)
4419 raid5_conf_t *conf = mddev_to_conf(mddev);
4422 if (mddev->delta_disks < 0 ||
4423 mddev->new_level != mddev->level)
4424 return -EINVAL; /* Cannot shrink array or change level yet */
4425 if (mddev->delta_disks == 0)
4426 return 0; /* nothing to do */
4428 /* Can only proceed if there are plenty of stripe_heads.
4429 * We need a minimum of one full stripe,, and for sensible progress
4430 * it is best to have about 4 times that.
4431 * If we require 4 times, then the default 256 4K stripe_heads will
4432 * allow for chunk sizes up to 256K, which is probably OK.
4433 * If the chunk size is greater, user-space should request more
4434 * stripe_heads first.
4436 if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
4437 (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
4438 printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
4439 (mddev->chunk_size / STRIPE_SIZE)*4);
4443 err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
4447 if (mddev->degraded > conf->max_degraded)
4449 /* looks like we might be able to manage this */
4453 static int raid5_start_reshape(mddev_t *mddev)
4455 raid5_conf_t *conf = mddev_to_conf(mddev);
4457 struct list_head *rtmp;
4459 int added_devices = 0;
4460 unsigned long flags;
4462 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4465 ITERATE_RDEV(mddev, rdev, rtmp)
4466 if (rdev->raid_disk < 0 &&
4467 !test_bit(Faulty, &rdev->flags))
4470 if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
4471 /* Not enough devices even to make a degraded array
4476 atomic_set(&conf->reshape_stripes, 0);
4477 spin_lock_irq(&conf->device_lock);
4478 conf->previous_raid_disks = conf->raid_disks;
4479 conf->raid_disks += mddev->delta_disks;
4480 conf->expand_progress = 0;
4481 conf->expand_lo = 0;
4482 spin_unlock_irq(&conf->device_lock);
4484 /* Add some new drives, as many as will fit.
4485 * We know there are enough to make the newly sized array work.
4487 ITERATE_RDEV(mddev, rdev, rtmp)
4488 if (rdev->raid_disk < 0 &&
4489 !test_bit(Faulty, &rdev->flags)) {
4490 if (raid5_add_disk(mddev, rdev)) {
4492 set_bit(In_sync, &rdev->flags);
4494 rdev->recovery_offset = 0;
4495 sprintf(nm, "rd%d", rdev->raid_disk);
4496 if (sysfs_create_link(&mddev->kobj,
4499 "raid5: failed to create "
4500 " link %s for %s\n",
4506 spin_lock_irqsave(&conf->device_lock, flags);
4507 mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
4508 spin_unlock_irqrestore(&conf->device_lock, flags);
4509 mddev->raid_disks = conf->raid_disks;
4510 mddev->reshape_position = 0;
4511 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4513 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4514 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4515 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4516 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4517 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4519 if (!mddev->sync_thread) {
4520 mddev->recovery = 0;
4521 spin_lock_irq(&conf->device_lock);
4522 mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
4523 conf->expand_progress = MaxSector;
4524 spin_unlock_irq(&conf->device_lock);
4527 md_wakeup_thread(mddev->sync_thread);
4528 md_new_event(mddev);
4533 static void end_reshape(raid5_conf_t *conf)
4535 struct block_device *bdev;
4537 if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
4538 conf->mddev->array_size = conf->mddev->size *
4539 (conf->raid_disks - conf->max_degraded);
4540 set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
4541 conf->mddev->changed = 1;
4543 bdev = bdget_disk(conf->mddev->gendisk, 0);
4545 mutex_lock(&bdev->bd_inode->i_mutex);
4546 i_size_write(bdev->bd_inode, (loff_t)conf->mddev->array_size << 10);
4547 mutex_unlock(&bdev->bd_inode->i_mutex);
4550 spin_lock_irq(&conf->device_lock);
4551 conf->expand_progress = MaxSector;
4552 spin_unlock_irq(&conf->device_lock);
4553 conf->mddev->reshape_position = MaxSector;
4555 /* read-ahead size must cover two whole stripes, which is
4556 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4559 int data_disks = conf->previous_raid_disks - conf->max_degraded;
4560 int stripe = data_disks *
4561 (conf->mddev->chunk_size / PAGE_SIZE);
4562 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4563 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4568 static void raid5_quiesce(mddev_t *mddev, int state)
4570 raid5_conf_t *conf = mddev_to_conf(mddev);
4573 case 2: /* resume for a suspend */
4574 wake_up(&conf->wait_for_overlap);
4577 case 1: /* stop all writes */
4578 spin_lock_irq(&conf->device_lock);
4580 wait_event_lock_irq(conf->wait_for_stripe,
4581 atomic_read(&conf->active_stripes) == 0 &&
4582 atomic_read(&conf->active_aligned_reads) == 0,
4583 conf->device_lock, /* nothing */);
4584 spin_unlock_irq(&conf->device_lock);
4587 case 0: /* re-enable writes */
4588 spin_lock_irq(&conf->device_lock);
4590 wake_up(&conf->wait_for_stripe);
4591 wake_up(&conf->wait_for_overlap);
4592 spin_unlock_irq(&conf->device_lock);
4597 static struct mdk_personality raid6_personality =
4601 .owner = THIS_MODULE,
4602 .make_request = make_request,
4606 .error_handler = error,
4607 .hot_add_disk = raid5_add_disk,
4608 .hot_remove_disk= raid5_remove_disk,
4609 .spare_active = raid5_spare_active,
4610 .sync_request = sync_request,
4611 .resize = raid5_resize,
4612 #ifdef CONFIG_MD_RAID5_RESHAPE
4613 .check_reshape = raid5_check_reshape,
4614 .start_reshape = raid5_start_reshape,
4616 .quiesce = raid5_quiesce,
4618 static struct mdk_personality raid5_personality =
4622 .owner = THIS_MODULE,
4623 .make_request = make_request,
4627 .error_handler = error,
4628 .hot_add_disk = raid5_add_disk,
4629 .hot_remove_disk= raid5_remove_disk,
4630 .spare_active = raid5_spare_active,
4631 .sync_request = sync_request,
4632 .resize = raid5_resize,
4633 #ifdef CONFIG_MD_RAID5_RESHAPE
4634 .check_reshape = raid5_check_reshape,
4635 .start_reshape = raid5_start_reshape,
4637 .quiesce = raid5_quiesce,
4640 static struct mdk_personality raid4_personality =
4644 .owner = THIS_MODULE,
4645 .make_request = make_request,
4649 .error_handler = error,
4650 .hot_add_disk = raid5_add_disk,
4651 .hot_remove_disk= raid5_remove_disk,
4652 .spare_active = raid5_spare_active,
4653 .sync_request = sync_request,
4654 .resize = raid5_resize,
4655 #ifdef CONFIG_MD_RAID5_RESHAPE
4656 .check_reshape = raid5_check_reshape,
4657 .start_reshape = raid5_start_reshape,
4659 .quiesce = raid5_quiesce,
4662 static int __init raid5_init(void)
4666 e = raid6_select_algo();
4669 register_md_personality(&raid6_personality);
4670 register_md_personality(&raid5_personality);
4671 register_md_personality(&raid4_personality);
4675 static void raid5_exit(void)
4677 unregister_md_personality(&raid6_personality);
4678 unregister_md_personality(&raid5_personality);
4679 unregister_md_personality(&raid4_personality);
4682 module_init(raid5_init);
4683 module_exit(raid5_exit);
4684 MODULE_LICENSE("GPL");
4685 MODULE_ALIAS("md-personality-4"); /* RAID5 */
4686 MODULE_ALIAS("md-raid5");
4687 MODULE_ALIAS("md-raid4");
4688 MODULE_ALIAS("md-level-5");
4689 MODULE_ALIAS("md-level-4");
4690 MODULE_ALIAS("md-personality-8"); /* RAID6 */
4691 MODULE_ALIAS("md-raid6");
4692 MODULE_ALIAS("md-level-6");
4694 /* This used to be two separate modules, they were: */
4695 MODULE_ALIAS("raid5");
4696 MODULE_ALIAS("raid6");