2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is seq_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/module.h>
51 #include <linux/async.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpu.h>
54 #include <linux/slab.h>
55 #include <linux/ratelimit.h>
65 #define NR_STRIPES 256
66 #define STRIPE_SIZE PAGE_SIZE
67 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
68 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
69 #define IO_THRESHOLD 1
70 #define BYPASS_THRESHOLD 1
71 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
72 #define HASH_MASK (NR_HASH - 1)
74 static inline struct hlist_head
*stripe_hash(struct r5conf
*conf
, sector_t sect
)
76 int hash
= (sect
>> STRIPE_SHIFT
) & HASH_MASK
;
77 return &conf
->stripe_hashtbl
[hash
];
80 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
81 * order without overlap. There may be several bio's per stripe+device, and
82 * a bio could span several devices.
83 * When walking this list for a particular stripe+device, we must never proceed
84 * beyond a bio that extends past this device, as the next bio might no longer
86 * This function is used to determine the 'next' bio in the list, given the sector
87 * of the current stripe+device
89 static inline struct bio
*r5_next_bio(struct bio
*bio
, sector_t sector
)
91 int sectors
= bio
->bi_size
>> 9;
92 if (bio
->bi_sector
+ sectors
< sector
+ STRIPE_SECTORS
)
99 * We maintain a biased count of active stripes in the bottom 16 bits of
100 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
102 static inline int raid5_bi_processed_stripes(struct bio
*bio
)
104 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
105 return (atomic_read(segments
) >> 16) & 0xffff;
108 static inline int raid5_dec_bi_active_stripes(struct bio
*bio
)
110 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
111 return atomic_sub_return(1, segments
) & 0xffff;
114 static inline void raid5_inc_bi_active_stripes(struct bio
*bio
)
116 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
117 atomic_inc(segments
);
120 static inline void raid5_set_bi_processed_stripes(struct bio
*bio
,
123 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
127 old
= atomic_read(segments
);
128 new = (old
& 0xffff) | (cnt
<< 16);
129 } while (atomic_cmpxchg(segments
, old
, new) != old
);
132 static inline void raid5_set_bi_stripes(struct bio
*bio
, unsigned int cnt
)
134 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
135 atomic_set(segments
, cnt
);
138 /* Find first data disk in a raid6 stripe */
139 static inline int raid6_d0(struct stripe_head
*sh
)
142 /* ddf always start from first device */
144 /* md starts just after Q block */
145 if (sh
->qd_idx
== sh
->disks
- 1)
148 return sh
->qd_idx
+ 1;
150 static inline int raid6_next_disk(int disk
, int raid_disks
)
153 return (disk
< raid_disks
) ? disk
: 0;
156 /* When walking through the disks in a raid5, starting at raid6_d0,
157 * We need to map each disk to a 'slot', where the data disks are slot
158 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
159 * is raid_disks-1. This help does that mapping.
161 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
162 int *count
, int syndrome_disks
)
168 if (idx
== sh
->pd_idx
)
169 return syndrome_disks
;
170 if (idx
== sh
->qd_idx
)
171 return syndrome_disks
+ 1;
177 static void return_io(struct bio
*return_bi
)
179 struct bio
*bi
= return_bi
;
182 return_bi
= bi
->bi_next
;
190 static void print_raid5_conf (struct r5conf
*conf
);
192 static int stripe_operations_active(struct stripe_head
*sh
)
194 return sh
->check_state
|| sh
->reconstruct_state
||
195 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
196 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
199 static void do_release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
201 BUG_ON(!list_empty(&sh
->lru
));
202 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
203 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
204 if (test_bit(STRIPE_DELAYED
, &sh
->state
) &&
205 !test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
206 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
207 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
208 sh
->bm_seq
- conf
->seq_write
> 0)
209 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
211 clear_bit(STRIPE_DELAYED
, &sh
->state
);
212 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
213 list_add_tail(&sh
->lru
, &conf
->handle_list
);
215 md_wakeup_thread(conf
->mddev
->thread
);
217 BUG_ON(stripe_operations_active(sh
));
218 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
219 if (atomic_dec_return(&conf
->preread_active_stripes
)
221 md_wakeup_thread(conf
->mddev
->thread
);
222 atomic_dec(&conf
->active_stripes
);
223 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
224 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
225 wake_up(&conf
->wait_for_stripe
);
226 if (conf
->retry_read_aligned
)
227 md_wakeup_thread(conf
->mddev
->thread
);
232 static void __release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
234 if (atomic_dec_and_test(&sh
->count
))
235 do_release_stripe(conf
, sh
);
238 static void release_stripe(struct stripe_head
*sh
)
240 struct r5conf
*conf
= sh
->raid_conf
;
243 local_irq_save(flags
);
244 if (atomic_dec_and_lock(&sh
->count
, &conf
->device_lock
)) {
245 do_release_stripe(conf
, sh
);
246 spin_unlock(&conf
->device_lock
);
248 local_irq_restore(flags
);
251 static inline void remove_hash(struct stripe_head
*sh
)
253 pr_debug("remove_hash(), stripe %llu\n",
254 (unsigned long long)sh
->sector
);
256 hlist_del_init(&sh
->hash
);
259 static inline void insert_hash(struct r5conf
*conf
, struct stripe_head
*sh
)
261 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
263 pr_debug("insert_hash(), stripe %llu\n",
264 (unsigned long long)sh
->sector
);
266 hlist_add_head(&sh
->hash
, hp
);
270 /* find an idle stripe, make sure it is unhashed, and return it. */
271 static struct stripe_head
*get_free_stripe(struct r5conf
*conf
)
273 struct stripe_head
*sh
= NULL
;
274 struct list_head
*first
;
276 if (list_empty(&conf
->inactive_list
))
278 first
= conf
->inactive_list
.next
;
279 sh
= list_entry(first
, struct stripe_head
, lru
);
280 list_del_init(first
);
282 atomic_inc(&conf
->active_stripes
);
287 static void shrink_buffers(struct stripe_head
*sh
)
291 int num
= sh
->raid_conf
->pool_size
;
293 for (i
= 0; i
< num
; i
++) {
297 sh
->dev
[i
].page
= NULL
;
302 static int grow_buffers(struct stripe_head
*sh
)
305 int num
= sh
->raid_conf
->pool_size
;
307 for (i
= 0; i
< num
; i
++) {
310 if (!(page
= alloc_page(GFP_KERNEL
))) {
313 sh
->dev
[i
].page
= page
;
318 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
);
319 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
320 struct stripe_head
*sh
);
322 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
324 struct r5conf
*conf
= sh
->raid_conf
;
327 BUG_ON(atomic_read(&sh
->count
) != 0);
328 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
329 BUG_ON(stripe_operations_active(sh
));
331 pr_debug("init_stripe called, stripe %llu\n",
332 (unsigned long long)sh
->sector
);
336 sh
->generation
= conf
->generation
- previous
;
337 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
339 stripe_set_idx(sector
, conf
, previous
, sh
);
343 for (i
= sh
->disks
; i
--; ) {
344 struct r5dev
*dev
= &sh
->dev
[i
];
346 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
347 test_bit(R5_LOCKED
, &dev
->flags
)) {
348 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
349 (unsigned long long)sh
->sector
, i
, dev
->toread
,
350 dev
->read
, dev
->towrite
, dev
->written
,
351 test_bit(R5_LOCKED
, &dev
->flags
));
355 raid5_build_block(sh
, i
, previous
);
357 insert_hash(conf
, sh
);
360 static struct stripe_head
*__find_stripe(struct r5conf
*conf
, sector_t sector
,
363 struct stripe_head
*sh
;
364 struct hlist_node
*hn
;
366 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
367 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
368 if (sh
->sector
== sector
&& sh
->generation
== generation
)
370 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
375 * Need to check if array has failed when deciding whether to:
377 * - remove non-faulty devices
380 * This determination is simple when no reshape is happening.
381 * However if there is a reshape, we need to carefully check
382 * both the before and after sections.
383 * This is because some failed devices may only affect one
384 * of the two sections, and some non-in_sync devices may
385 * be insync in the section most affected by failed devices.
387 static int calc_degraded(struct r5conf
*conf
)
389 int degraded
, degraded2
;
394 for (i
= 0; i
< conf
->previous_raid_disks
; i
++) {
395 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
396 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
398 else if (test_bit(In_sync
, &rdev
->flags
))
401 /* not in-sync or faulty.
402 * If the reshape increases the number of devices,
403 * this is being recovered by the reshape, so
404 * this 'previous' section is not in_sync.
405 * If the number of devices is being reduced however,
406 * the device can only be part of the array if
407 * we are reverting a reshape, so this section will
410 if (conf
->raid_disks
>= conf
->previous_raid_disks
)
414 if (conf
->raid_disks
== conf
->previous_raid_disks
)
418 for (i
= 0; i
< conf
->raid_disks
; i
++) {
419 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
420 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
422 else if (test_bit(In_sync
, &rdev
->flags
))
425 /* not in-sync or faulty.
426 * If reshape increases the number of devices, this
427 * section has already been recovered, else it
428 * almost certainly hasn't.
430 if (conf
->raid_disks
<= conf
->previous_raid_disks
)
434 if (degraded2
> degraded
)
439 static int has_failed(struct r5conf
*conf
)
443 if (conf
->mddev
->reshape_position
== MaxSector
)
444 return conf
->mddev
->degraded
> conf
->max_degraded
;
446 degraded
= calc_degraded(conf
);
447 if (degraded
> conf
->max_degraded
)
452 static struct stripe_head
*
453 get_active_stripe(struct r5conf
*conf
, sector_t sector
,
454 int previous
, int noblock
, int noquiesce
)
456 struct stripe_head
*sh
;
458 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
460 spin_lock_irq(&conf
->device_lock
);
463 wait_event_lock_irq(conf
->wait_for_stripe
,
464 conf
->quiesce
== 0 || noquiesce
,
465 conf
->device_lock
, /* nothing */);
466 sh
= __find_stripe(conf
, sector
, conf
->generation
- previous
);
468 if (!conf
->inactive_blocked
)
469 sh
= get_free_stripe(conf
);
470 if (noblock
&& sh
== NULL
)
473 conf
->inactive_blocked
= 1;
474 wait_event_lock_irq(conf
->wait_for_stripe
,
475 !list_empty(&conf
->inactive_list
) &&
476 (atomic_read(&conf
->active_stripes
)
477 < (conf
->max_nr_stripes
*3/4)
478 || !conf
->inactive_blocked
),
481 conf
->inactive_blocked
= 0;
483 init_stripe(sh
, sector
, previous
);
485 if (atomic_read(&sh
->count
)) {
486 BUG_ON(!list_empty(&sh
->lru
)
487 && !test_bit(STRIPE_EXPANDING
, &sh
->state
));
489 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
490 atomic_inc(&conf
->active_stripes
);
491 if (list_empty(&sh
->lru
) &&
492 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
494 list_del_init(&sh
->lru
);
497 } while (sh
== NULL
);
500 atomic_inc(&sh
->count
);
502 spin_unlock_irq(&conf
->device_lock
);
506 /* Determine if 'data_offset' or 'new_data_offset' should be used
507 * in this stripe_head.
509 static int use_new_offset(struct r5conf
*conf
, struct stripe_head
*sh
)
511 sector_t progress
= conf
->reshape_progress
;
512 /* Need a memory barrier to make sure we see the value
513 * of conf->generation, or ->data_offset that was set before
514 * reshape_progress was updated.
517 if (progress
== MaxSector
)
519 if (sh
->generation
== conf
->generation
- 1)
521 /* We are in a reshape, and this is a new-generation stripe,
522 * so use new_data_offset.
528 raid5_end_read_request(struct bio
*bi
, int error
);
530 raid5_end_write_request(struct bio
*bi
, int error
);
532 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
534 struct r5conf
*conf
= sh
->raid_conf
;
535 int i
, disks
= sh
->disks
;
539 for (i
= disks
; i
--; ) {
541 int replace_only
= 0;
542 struct bio
*bi
, *rbi
;
543 struct md_rdev
*rdev
, *rrdev
= NULL
;
544 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
)) {
545 if (test_and_clear_bit(R5_WantFUA
, &sh
->dev
[i
].flags
))
549 } else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
551 else if (test_and_clear_bit(R5_WantReplace
,
552 &sh
->dev
[i
].flags
)) {
557 if (test_and_clear_bit(R5_SyncIO
, &sh
->dev
[i
].flags
))
560 bi
= &sh
->dev
[i
].req
;
561 rbi
= &sh
->dev
[i
].rreq
; /* For writing to replacement */
566 bi
->bi_end_io
= raid5_end_write_request
;
567 rbi
->bi_end_io
= raid5_end_write_request
;
569 bi
->bi_end_io
= raid5_end_read_request
;
572 rrdev
= rcu_dereference(conf
->disks
[i
].replacement
);
573 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
574 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
583 /* We raced and saw duplicates */
586 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
) && rrdev
)
591 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
594 atomic_inc(&rdev
->nr_pending
);
595 if (rrdev
&& test_bit(Faulty
, &rrdev
->flags
))
598 atomic_inc(&rrdev
->nr_pending
);
601 /* We have already checked bad blocks for reads. Now
602 * need to check for writes. We never accept write errors
603 * on the replacement, so we don't to check rrdev.
605 while ((rw
& WRITE
) && rdev
&&
606 test_bit(WriteErrorSeen
, &rdev
->flags
)) {
609 int bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
610 &first_bad
, &bad_sectors
);
615 set_bit(BlockedBadBlocks
, &rdev
->flags
);
616 if (!conf
->mddev
->external
&&
617 conf
->mddev
->flags
) {
618 /* It is very unlikely, but we might
619 * still need to write out the
620 * bad block log - better give it
622 md_check_recovery(conf
->mddev
);
625 * Because md_wait_for_blocked_rdev
626 * will dec nr_pending, we must
627 * increment it first.
629 atomic_inc(&rdev
->nr_pending
);
630 md_wait_for_blocked_rdev(rdev
, conf
->mddev
);
632 /* Acknowledged bad block - skip the write */
633 rdev_dec_pending(rdev
, conf
->mddev
);
639 if (s
->syncing
|| s
->expanding
|| s
->expanded
641 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
643 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
645 bi
->bi_bdev
= rdev
->bdev
;
646 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
647 __func__
, (unsigned long long)sh
->sector
,
649 atomic_inc(&sh
->count
);
650 if (use_new_offset(conf
, sh
))
651 bi
->bi_sector
= (sh
->sector
652 + rdev
->new_data_offset
);
654 bi
->bi_sector
= (sh
->sector
655 + rdev
->data_offset
);
656 bi
->bi_flags
= 1 << BIO_UPTODATE
;
658 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
659 bi
->bi_io_vec
[0].bv_offset
= 0;
660 bi
->bi_size
= STRIPE_SIZE
;
663 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
664 generic_make_request(bi
);
667 if (s
->syncing
|| s
->expanding
|| s
->expanded
669 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
671 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
673 rbi
->bi_bdev
= rrdev
->bdev
;
674 pr_debug("%s: for %llu schedule op %ld on "
675 "replacement disc %d\n",
676 __func__
, (unsigned long long)sh
->sector
,
678 atomic_inc(&sh
->count
);
679 if (use_new_offset(conf
, sh
))
680 rbi
->bi_sector
= (sh
->sector
681 + rrdev
->new_data_offset
);
683 rbi
->bi_sector
= (sh
->sector
684 + rrdev
->data_offset
);
685 rbi
->bi_flags
= 1 << BIO_UPTODATE
;
687 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
688 rbi
->bi_io_vec
[0].bv_offset
= 0;
689 rbi
->bi_size
= STRIPE_SIZE
;
691 generic_make_request(rbi
);
693 if (!rdev
&& !rrdev
) {
695 set_bit(STRIPE_DEGRADED
, &sh
->state
);
696 pr_debug("skip op %ld on disc %d for sector %llu\n",
697 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
698 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
699 set_bit(STRIPE_HANDLE
, &sh
->state
);
704 static struct dma_async_tx_descriptor
*
705 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
706 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
709 struct page
*bio_page
;
712 struct async_submit_ctl submit
;
713 enum async_tx_flags flags
= 0;
715 if (bio
->bi_sector
>= sector
)
716 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
718 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
721 flags
|= ASYNC_TX_FENCE
;
722 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
724 bio_for_each_segment(bvl
, bio
, i
) {
725 int len
= bvl
->bv_len
;
729 if (page_offset
< 0) {
730 b_offset
= -page_offset
;
731 page_offset
+= b_offset
;
735 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
736 clen
= STRIPE_SIZE
- page_offset
;
741 b_offset
+= bvl
->bv_offset
;
742 bio_page
= bvl
->bv_page
;
744 tx
= async_memcpy(page
, bio_page
, page_offset
,
745 b_offset
, clen
, &submit
);
747 tx
= async_memcpy(bio_page
, page
, b_offset
,
748 page_offset
, clen
, &submit
);
750 /* chain the operations */
751 submit
.depend_tx
= tx
;
753 if (clen
< len
) /* hit end of page */
761 static void ops_complete_biofill(void *stripe_head_ref
)
763 struct stripe_head
*sh
= stripe_head_ref
;
764 struct bio
*return_bi
= NULL
;
765 struct r5conf
*conf
= sh
->raid_conf
;
768 pr_debug("%s: stripe %llu\n", __func__
,
769 (unsigned long long)sh
->sector
);
771 /* clear completed biofills */
772 spin_lock_irq(&conf
->device_lock
);
773 for (i
= sh
->disks
; i
--; ) {
774 struct r5dev
*dev
= &sh
->dev
[i
];
776 /* acknowledge completion of a biofill operation */
777 /* and check if we need to reply to a read request,
778 * new R5_Wantfill requests are held off until
779 * !STRIPE_BIOFILL_RUN
781 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
782 struct bio
*rbi
, *rbi2
;
787 while (rbi
&& rbi
->bi_sector
<
788 dev
->sector
+ STRIPE_SECTORS
) {
789 rbi2
= r5_next_bio(rbi
, dev
->sector
);
790 if (!raid5_dec_bi_active_stripes(rbi
)) {
791 rbi
->bi_next
= return_bi
;
798 spin_unlock_irq(&conf
->device_lock
);
799 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
801 return_io(return_bi
);
803 set_bit(STRIPE_HANDLE
, &sh
->state
);
807 static void ops_run_biofill(struct stripe_head
*sh
)
809 struct dma_async_tx_descriptor
*tx
= NULL
;
810 struct r5conf
*conf
= sh
->raid_conf
;
811 struct async_submit_ctl submit
;
814 pr_debug("%s: stripe %llu\n", __func__
,
815 (unsigned long long)sh
->sector
);
817 for (i
= sh
->disks
; i
--; ) {
818 struct r5dev
*dev
= &sh
->dev
[i
];
819 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
821 spin_lock_irq(&conf
->device_lock
);
822 dev
->read
= rbi
= dev
->toread
;
824 spin_unlock_irq(&conf
->device_lock
);
825 while (rbi
&& rbi
->bi_sector
<
826 dev
->sector
+ STRIPE_SECTORS
) {
827 tx
= async_copy_data(0, rbi
, dev
->page
,
829 rbi
= r5_next_bio(rbi
, dev
->sector
);
834 atomic_inc(&sh
->count
);
835 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
836 async_trigger_callback(&submit
);
839 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
846 tgt
= &sh
->dev
[target
];
847 set_bit(R5_UPTODATE
, &tgt
->flags
);
848 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
849 clear_bit(R5_Wantcompute
, &tgt
->flags
);
852 static void ops_complete_compute(void *stripe_head_ref
)
854 struct stripe_head
*sh
= stripe_head_ref
;
856 pr_debug("%s: stripe %llu\n", __func__
,
857 (unsigned long long)sh
->sector
);
859 /* mark the computed target(s) as uptodate */
860 mark_target_uptodate(sh
, sh
->ops
.target
);
861 mark_target_uptodate(sh
, sh
->ops
.target2
);
863 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
864 if (sh
->check_state
== check_state_compute_run
)
865 sh
->check_state
= check_state_compute_result
;
866 set_bit(STRIPE_HANDLE
, &sh
->state
);
870 /* return a pointer to the address conversion region of the scribble buffer */
871 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
872 struct raid5_percpu
*percpu
)
874 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
877 static struct dma_async_tx_descriptor
*
878 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
880 int disks
= sh
->disks
;
881 struct page
**xor_srcs
= percpu
->scribble
;
882 int target
= sh
->ops
.target
;
883 struct r5dev
*tgt
= &sh
->dev
[target
];
884 struct page
*xor_dest
= tgt
->page
;
886 struct dma_async_tx_descriptor
*tx
;
887 struct async_submit_ctl submit
;
890 pr_debug("%s: stripe %llu block: %d\n",
891 __func__
, (unsigned long long)sh
->sector
, target
);
892 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
894 for (i
= disks
; i
--; )
896 xor_srcs
[count
++] = sh
->dev
[i
].page
;
898 atomic_inc(&sh
->count
);
900 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
901 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
902 if (unlikely(count
== 1))
903 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
905 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
910 /* set_syndrome_sources - populate source buffers for gen_syndrome
911 * @srcs - (struct page *) array of size sh->disks
912 * @sh - stripe_head to parse
914 * Populates srcs in proper layout order for the stripe and returns the
915 * 'count' of sources to be used in a call to async_gen_syndrome. The P
916 * destination buffer is recorded in srcs[count] and the Q destination
917 * is recorded in srcs[count+1]].
919 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
921 int disks
= sh
->disks
;
922 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
923 int d0_idx
= raid6_d0(sh
);
927 for (i
= 0; i
< disks
; i
++)
933 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
935 srcs
[slot
] = sh
->dev
[i
].page
;
936 i
= raid6_next_disk(i
, disks
);
937 } while (i
!= d0_idx
);
939 return syndrome_disks
;
942 static struct dma_async_tx_descriptor
*
943 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
945 int disks
= sh
->disks
;
946 struct page
**blocks
= percpu
->scribble
;
948 int qd_idx
= sh
->qd_idx
;
949 struct dma_async_tx_descriptor
*tx
;
950 struct async_submit_ctl submit
;
956 if (sh
->ops
.target
< 0)
957 target
= sh
->ops
.target2
;
958 else if (sh
->ops
.target2
< 0)
959 target
= sh
->ops
.target
;
961 /* we should only have one valid target */
964 pr_debug("%s: stripe %llu block: %d\n",
965 __func__
, (unsigned long long)sh
->sector
, target
);
967 tgt
= &sh
->dev
[target
];
968 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
971 atomic_inc(&sh
->count
);
973 if (target
== qd_idx
) {
974 count
= set_syndrome_sources(blocks
, sh
);
975 blocks
[count
] = NULL
; /* regenerating p is not necessary */
976 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
977 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
978 ops_complete_compute
, sh
,
979 to_addr_conv(sh
, percpu
));
980 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
982 /* Compute any data- or p-drive using XOR */
984 for (i
= disks
; i
-- ; ) {
985 if (i
== target
|| i
== qd_idx
)
987 blocks
[count
++] = sh
->dev
[i
].page
;
990 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
991 NULL
, ops_complete_compute
, sh
,
992 to_addr_conv(sh
, percpu
));
993 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
999 static struct dma_async_tx_descriptor
*
1000 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1002 int i
, count
, disks
= sh
->disks
;
1003 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1004 int d0_idx
= raid6_d0(sh
);
1005 int faila
= -1, failb
= -1;
1006 int target
= sh
->ops
.target
;
1007 int target2
= sh
->ops
.target2
;
1008 struct r5dev
*tgt
= &sh
->dev
[target
];
1009 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1010 struct dma_async_tx_descriptor
*tx
;
1011 struct page
**blocks
= percpu
->scribble
;
1012 struct async_submit_ctl submit
;
1014 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1015 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1016 BUG_ON(target
< 0 || target2
< 0);
1017 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1018 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1020 /* we need to open-code set_syndrome_sources to handle the
1021 * slot number conversion for 'faila' and 'failb'
1023 for (i
= 0; i
< disks
; i
++)
1028 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1030 blocks
[slot
] = sh
->dev
[i
].page
;
1036 i
= raid6_next_disk(i
, disks
);
1037 } while (i
!= d0_idx
);
1039 BUG_ON(faila
== failb
);
1042 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1043 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1045 atomic_inc(&sh
->count
);
1047 if (failb
== syndrome_disks
+1) {
1048 /* Q disk is one of the missing disks */
1049 if (faila
== syndrome_disks
) {
1050 /* Missing P+Q, just recompute */
1051 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1052 ops_complete_compute
, sh
,
1053 to_addr_conv(sh
, percpu
));
1054 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1055 STRIPE_SIZE
, &submit
);
1059 int qd_idx
= sh
->qd_idx
;
1061 /* Missing D+Q: recompute D from P, then recompute Q */
1062 if (target
== qd_idx
)
1063 data_target
= target2
;
1065 data_target
= target
;
1068 for (i
= disks
; i
-- ; ) {
1069 if (i
== data_target
|| i
== qd_idx
)
1071 blocks
[count
++] = sh
->dev
[i
].page
;
1073 dest
= sh
->dev
[data_target
].page
;
1074 init_async_submit(&submit
,
1075 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1077 to_addr_conv(sh
, percpu
));
1078 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1081 count
= set_syndrome_sources(blocks
, sh
);
1082 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1083 ops_complete_compute
, sh
,
1084 to_addr_conv(sh
, percpu
));
1085 return async_gen_syndrome(blocks
, 0, count
+2,
1086 STRIPE_SIZE
, &submit
);
1089 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1090 ops_complete_compute
, sh
,
1091 to_addr_conv(sh
, percpu
));
1092 if (failb
== syndrome_disks
) {
1093 /* We're missing D+P. */
1094 return async_raid6_datap_recov(syndrome_disks
+2,
1098 /* We're missing D+D. */
1099 return async_raid6_2data_recov(syndrome_disks
+2,
1100 STRIPE_SIZE
, faila
, failb
,
1107 static void ops_complete_prexor(void *stripe_head_ref
)
1109 struct stripe_head
*sh
= stripe_head_ref
;
1111 pr_debug("%s: stripe %llu\n", __func__
,
1112 (unsigned long long)sh
->sector
);
1115 static struct dma_async_tx_descriptor
*
1116 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1117 struct dma_async_tx_descriptor
*tx
)
1119 int disks
= sh
->disks
;
1120 struct page
**xor_srcs
= percpu
->scribble
;
1121 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1122 struct async_submit_ctl submit
;
1124 /* existing parity data subtracted */
1125 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1127 pr_debug("%s: stripe %llu\n", __func__
,
1128 (unsigned long long)sh
->sector
);
1130 for (i
= disks
; i
--; ) {
1131 struct r5dev
*dev
= &sh
->dev
[i
];
1132 /* Only process blocks that are known to be uptodate */
1133 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1134 xor_srcs
[count
++] = dev
->page
;
1137 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1138 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1139 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1144 static struct dma_async_tx_descriptor
*
1145 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1147 int disks
= sh
->disks
;
1150 pr_debug("%s: stripe %llu\n", __func__
,
1151 (unsigned long long)sh
->sector
);
1153 for (i
= disks
; i
--; ) {
1154 struct r5dev
*dev
= &sh
->dev
[i
];
1157 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1160 spin_lock_irq(&sh
->raid_conf
->device_lock
);
1161 chosen
= dev
->towrite
;
1162 dev
->towrite
= NULL
;
1163 BUG_ON(dev
->written
);
1164 wbi
= dev
->written
= chosen
;
1165 spin_unlock_irq(&sh
->raid_conf
->device_lock
);
1167 while (wbi
&& wbi
->bi_sector
<
1168 dev
->sector
+ STRIPE_SECTORS
) {
1169 if (wbi
->bi_rw
& REQ_FUA
)
1170 set_bit(R5_WantFUA
, &dev
->flags
);
1171 if (wbi
->bi_rw
& REQ_SYNC
)
1172 set_bit(R5_SyncIO
, &dev
->flags
);
1173 tx
= async_copy_data(1, wbi
, dev
->page
,
1175 wbi
= r5_next_bio(wbi
, dev
->sector
);
1183 static void ops_complete_reconstruct(void *stripe_head_ref
)
1185 struct stripe_head
*sh
= stripe_head_ref
;
1186 int disks
= sh
->disks
;
1187 int pd_idx
= sh
->pd_idx
;
1188 int qd_idx
= sh
->qd_idx
;
1190 bool fua
= false, sync
= false;
1192 pr_debug("%s: stripe %llu\n", __func__
,
1193 (unsigned long long)sh
->sector
);
1195 for (i
= disks
; i
--; ) {
1196 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1197 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1200 for (i
= disks
; i
--; ) {
1201 struct r5dev
*dev
= &sh
->dev
[i
];
1203 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1204 set_bit(R5_UPTODATE
, &dev
->flags
);
1206 set_bit(R5_WantFUA
, &dev
->flags
);
1208 set_bit(R5_SyncIO
, &dev
->flags
);
1212 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1213 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1214 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1215 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1217 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1218 sh
->reconstruct_state
= reconstruct_state_result
;
1221 set_bit(STRIPE_HANDLE
, &sh
->state
);
1226 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1227 struct dma_async_tx_descriptor
*tx
)
1229 int disks
= sh
->disks
;
1230 struct page
**xor_srcs
= percpu
->scribble
;
1231 struct async_submit_ctl submit
;
1232 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1233 struct page
*xor_dest
;
1235 unsigned long flags
;
1237 pr_debug("%s: stripe %llu\n", __func__
,
1238 (unsigned long long)sh
->sector
);
1240 /* check if prexor is active which means only process blocks
1241 * that are part of a read-modify-write (written)
1243 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1245 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1246 for (i
= disks
; i
--; ) {
1247 struct r5dev
*dev
= &sh
->dev
[i
];
1249 xor_srcs
[count
++] = dev
->page
;
1252 xor_dest
= sh
->dev
[pd_idx
].page
;
1253 for (i
= disks
; i
--; ) {
1254 struct r5dev
*dev
= &sh
->dev
[i
];
1256 xor_srcs
[count
++] = dev
->page
;
1260 /* 1/ if we prexor'd then the dest is reused as a source
1261 * 2/ if we did not prexor then we are redoing the parity
1262 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1263 * for the synchronous xor case
1265 flags
= ASYNC_TX_ACK
|
1266 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1268 atomic_inc(&sh
->count
);
1270 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1271 to_addr_conv(sh
, percpu
));
1272 if (unlikely(count
== 1))
1273 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1275 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1279 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1280 struct dma_async_tx_descriptor
*tx
)
1282 struct async_submit_ctl submit
;
1283 struct page
**blocks
= percpu
->scribble
;
1286 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1288 count
= set_syndrome_sources(blocks
, sh
);
1290 atomic_inc(&sh
->count
);
1292 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1293 sh
, to_addr_conv(sh
, percpu
));
1294 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1297 static void ops_complete_check(void *stripe_head_ref
)
1299 struct stripe_head
*sh
= stripe_head_ref
;
1301 pr_debug("%s: stripe %llu\n", __func__
,
1302 (unsigned long long)sh
->sector
);
1304 sh
->check_state
= check_state_check_result
;
1305 set_bit(STRIPE_HANDLE
, &sh
->state
);
1309 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1311 int disks
= sh
->disks
;
1312 int pd_idx
= sh
->pd_idx
;
1313 int qd_idx
= sh
->qd_idx
;
1314 struct page
*xor_dest
;
1315 struct page
**xor_srcs
= percpu
->scribble
;
1316 struct dma_async_tx_descriptor
*tx
;
1317 struct async_submit_ctl submit
;
1321 pr_debug("%s: stripe %llu\n", __func__
,
1322 (unsigned long long)sh
->sector
);
1325 xor_dest
= sh
->dev
[pd_idx
].page
;
1326 xor_srcs
[count
++] = xor_dest
;
1327 for (i
= disks
; i
--; ) {
1328 if (i
== pd_idx
|| i
== qd_idx
)
1330 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1333 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1334 to_addr_conv(sh
, percpu
));
1335 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1336 &sh
->ops
.zero_sum_result
, &submit
);
1338 atomic_inc(&sh
->count
);
1339 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1340 tx
= async_trigger_callback(&submit
);
1343 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1345 struct page
**srcs
= percpu
->scribble
;
1346 struct async_submit_ctl submit
;
1349 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1350 (unsigned long long)sh
->sector
, checkp
);
1352 count
= set_syndrome_sources(srcs
, sh
);
1356 atomic_inc(&sh
->count
);
1357 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1358 sh
, to_addr_conv(sh
, percpu
));
1359 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1360 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1363 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1365 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1366 struct dma_async_tx_descriptor
*tx
= NULL
;
1367 struct r5conf
*conf
= sh
->raid_conf
;
1368 int level
= conf
->level
;
1369 struct raid5_percpu
*percpu
;
1373 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1374 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1375 ops_run_biofill(sh
);
1379 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1381 tx
= ops_run_compute5(sh
, percpu
);
1383 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1384 tx
= ops_run_compute6_1(sh
, percpu
);
1386 tx
= ops_run_compute6_2(sh
, percpu
);
1388 /* terminate the chain if reconstruct is not set to be run */
1389 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1393 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1394 tx
= ops_run_prexor(sh
, percpu
, tx
);
1396 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1397 tx
= ops_run_biodrain(sh
, tx
);
1401 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1403 ops_run_reconstruct5(sh
, percpu
, tx
);
1405 ops_run_reconstruct6(sh
, percpu
, tx
);
1408 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1409 if (sh
->check_state
== check_state_run
)
1410 ops_run_check_p(sh
, percpu
);
1411 else if (sh
->check_state
== check_state_run_q
)
1412 ops_run_check_pq(sh
, percpu
, 0);
1413 else if (sh
->check_state
== check_state_run_pq
)
1414 ops_run_check_pq(sh
, percpu
, 1);
1420 for (i
= disks
; i
--; ) {
1421 struct r5dev
*dev
= &sh
->dev
[i
];
1422 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1423 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1428 #ifdef CONFIG_MULTICORE_RAID456
1429 static void async_run_ops(void *param
, async_cookie_t cookie
)
1431 struct stripe_head
*sh
= param
;
1432 unsigned long ops_request
= sh
->ops
.request
;
1434 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1435 wake_up(&sh
->ops
.wait_for_ops
);
1437 __raid_run_ops(sh
, ops_request
);
1441 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1443 /* since handle_stripe can be called outside of raid5d context
1444 * we need to ensure sh->ops.request is de-staged before another
1447 wait_event(sh
->ops
.wait_for_ops
,
1448 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1449 sh
->ops
.request
= ops_request
;
1451 atomic_inc(&sh
->count
);
1452 async_schedule(async_run_ops
, sh
);
1455 #define raid_run_ops __raid_run_ops
1458 static int grow_one_stripe(struct r5conf
*conf
)
1460 struct stripe_head
*sh
;
1461 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1465 sh
->raid_conf
= conf
;
1466 #ifdef CONFIG_MULTICORE_RAID456
1467 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1470 if (grow_buffers(sh
)) {
1472 kmem_cache_free(conf
->slab_cache
, sh
);
1475 /* we just created an active stripe so... */
1476 atomic_set(&sh
->count
, 1);
1477 atomic_inc(&conf
->active_stripes
);
1478 INIT_LIST_HEAD(&sh
->lru
);
1483 static int grow_stripes(struct r5conf
*conf
, int num
)
1485 struct kmem_cache
*sc
;
1486 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1488 if (conf
->mddev
->gendisk
)
1489 sprintf(conf
->cache_name
[0],
1490 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1492 sprintf(conf
->cache_name
[0],
1493 "raid%d-%p", conf
->level
, conf
->mddev
);
1494 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1496 conf
->active_name
= 0;
1497 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1498 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1502 conf
->slab_cache
= sc
;
1503 conf
->pool_size
= devs
;
1505 if (!grow_one_stripe(conf
))
1511 * scribble_len - return the required size of the scribble region
1512 * @num - total number of disks in the array
1514 * The size must be enough to contain:
1515 * 1/ a struct page pointer for each device in the array +2
1516 * 2/ room to convert each entry in (1) to its corresponding dma
1517 * (dma_map_page()) or page (page_address()) address.
1519 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1520 * calculate over all devices (not just the data blocks), using zeros in place
1521 * of the P and Q blocks.
1523 static size_t scribble_len(int num
)
1527 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1532 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1534 /* Make all the stripes able to hold 'newsize' devices.
1535 * New slots in each stripe get 'page' set to a new page.
1537 * This happens in stages:
1538 * 1/ create a new kmem_cache and allocate the required number of
1540 * 2/ gather all the old stripe_heads and tranfer the pages across
1541 * to the new stripe_heads. This will have the side effect of
1542 * freezing the array as once all stripe_heads have been collected,
1543 * no IO will be possible. Old stripe heads are freed once their
1544 * pages have been transferred over, and the old kmem_cache is
1545 * freed when all stripes are done.
1546 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1547 * we simple return a failre status - no need to clean anything up.
1548 * 4/ allocate new pages for the new slots in the new stripe_heads.
1549 * If this fails, we don't bother trying the shrink the
1550 * stripe_heads down again, we just leave them as they are.
1551 * As each stripe_head is processed the new one is released into
1554 * Once step2 is started, we cannot afford to wait for a write,
1555 * so we use GFP_NOIO allocations.
1557 struct stripe_head
*osh
, *nsh
;
1558 LIST_HEAD(newstripes
);
1559 struct disk_info
*ndisks
;
1562 struct kmem_cache
*sc
;
1565 if (newsize
<= conf
->pool_size
)
1566 return 0; /* never bother to shrink */
1568 err
= md_allow_write(conf
->mddev
);
1573 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1574 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1579 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1580 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1584 nsh
->raid_conf
= conf
;
1585 #ifdef CONFIG_MULTICORE_RAID456
1586 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1589 list_add(&nsh
->lru
, &newstripes
);
1592 /* didn't get enough, give up */
1593 while (!list_empty(&newstripes
)) {
1594 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1595 list_del(&nsh
->lru
);
1596 kmem_cache_free(sc
, nsh
);
1598 kmem_cache_destroy(sc
);
1601 /* Step 2 - Must use GFP_NOIO now.
1602 * OK, we have enough stripes, start collecting inactive
1603 * stripes and copying them over
1605 list_for_each_entry(nsh
, &newstripes
, lru
) {
1606 spin_lock_irq(&conf
->device_lock
);
1607 wait_event_lock_irq(conf
->wait_for_stripe
,
1608 !list_empty(&conf
->inactive_list
),
1611 osh
= get_free_stripe(conf
);
1612 spin_unlock_irq(&conf
->device_lock
);
1613 atomic_set(&nsh
->count
, 1);
1614 for(i
=0; i
<conf
->pool_size
; i
++)
1615 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1616 for( ; i
<newsize
; i
++)
1617 nsh
->dev
[i
].page
= NULL
;
1618 kmem_cache_free(conf
->slab_cache
, osh
);
1620 kmem_cache_destroy(conf
->slab_cache
);
1623 * At this point, we are holding all the stripes so the array
1624 * is completely stalled, so now is a good time to resize
1625 * conf->disks and the scribble region
1627 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1629 for (i
=0; i
<conf
->raid_disks
; i
++)
1630 ndisks
[i
] = conf
->disks
[i
];
1632 conf
->disks
= ndisks
;
1637 conf
->scribble_len
= scribble_len(newsize
);
1638 for_each_present_cpu(cpu
) {
1639 struct raid5_percpu
*percpu
;
1642 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1643 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1646 kfree(percpu
->scribble
);
1647 percpu
->scribble
= scribble
;
1655 /* Step 4, return new stripes to service */
1656 while(!list_empty(&newstripes
)) {
1657 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1658 list_del_init(&nsh
->lru
);
1660 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1661 if (nsh
->dev
[i
].page
== NULL
) {
1662 struct page
*p
= alloc_page(GFP_NOIO
);
1663 nsh
->dev
[i
].page
= p
;
1667 release_stripe(nsh
);
1669 /* critical section pass, GFP_NOIO no longer needed */
1671 conf
->slab_cache
= sc
;
1672 conf
->active_name
= 1-conf
->active_name
;
1673 conf
->pool_size
= newsize
;
1677 static int drop_one_stripe(struct r5conf
*conf
)
1679 struct stripe_head
*sh
;
1681 spin_lock_irq(&conf
->device_lock
);
1682 sh
= get_free_stripe(conf
);
1683 spin_unlock_irq(&conf
->device_lock
);
1686 BUG_ON(atomic_read(&sh
->count
));
1688 kmem_cache_free(conf
->slab_cache
, sh
);
1689 atomic_dec(&conf
->active_stripes
);
1693 static void shrink_stripes(struct r5conf
*conf
)
1695 while (drop_one_stripe(conf
))
1698 if (conf
->slab_cache
)
1699 kmem_cache_destroy(conf
->slab_cache
);
1700 conf
->slab_cache
= NULL
;
1703 static void raid5_end_read_request(struct bio
* bi
, int error
)
1705 struct stripe_head
*sh
= bi
->bi_private
;
1706 struct r5conf
*conf
= sh
->raid_conf
;
1707 int disks
= sh
->disks
, i
;
1708 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1709 char b
[BDEVNAME_SIZE
];
1710 struct md_rdev
*rdev
= NULL
;
1713 for (i
=0 ; i
<disks
; i
++)
1714 if (bi
== &sh
->dev
[i
].req
)
1717 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1718 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1724 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1725 /* If replacement finished while this request was outstanding,
1726 * 'replacement' might be NULL already.
1727 * In that case it moved down to 'rdev'.
1728 * rdev is not removed until all requests are finished.
1730 rdev
= conf
->disks
[i
].replacement
;
1732 rdev
= conf
->disks
[i
].rdev
;
1734 if (use_new_offset(conf
, sh
))
1735 s
= sh
->sector
+ rdev
->new_data_offset
;
1737 s
= sh
->sector
+ rdev
->data_offset
;
1739 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1740 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1741 /* Note that this cannot happen on a
1742 * replacement device. We just fail those on
1747 "md/raid:%s: read error corrected"
1748 " (%lu sectors at %llu on %s)\n",
1749 mdname(conf
->mddev
), STRIPE_SECTORS
,
1750 (unsigned long long)s
,
1751 bdevname(rdev
->bdev
, b
));
1752 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1753 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1754 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1756 if (atomic_read(&rdev
->read_errors
))
1757 atomic_set(&rdev
->read_errors
, 0);
1759 const char *bdn
= bdevname(rdev
->bdev
, b
);
1763 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1764 atomic_inc(&rdev
->read_errors
);
1765 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1768 "md/raid:%s: read error on replacement device "
1769 "(sector %llu on %s).\n",
1770 mdname(conf
->mddev
),
1771 (unsigned long long)s
,
1773 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1777 "md/raid:%s: read error not correctable "
1778 "(sector %llu on %s).\n",
1779 mdname(conf
->mddev
),
1780 (unsigned long long)s
,
1782 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1787 "md/raid:%s: read error NOT corrected!! "
1788 "(sector %llu on %s).\n",
1789 mdname(conf
->mddev
),
1790 (unsigned long long)s
,
1792 } else if (atomic_read(&rdev
->read_errors
)
1793 > conf
->max_nr_stripes
)
1795 "md/raid:%s: Too many read errors, failing device %s.\n",
1796 mdname(conf
->mddev
), bdn
);
1800 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1802 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1803 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1805 && test_bit(In_sync
, &rdev
->flags
)
1806 && rdev_set_badblocks(
1807 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1808 md_error(conf
->mddev
, rdev
);
1811 rdev_dec_pending(rdev
, conf
->mddev
);
1812 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1813 set_bit(STRIPE_HANDLE
, &sh
->state
);
1817 static void raid5_end_write_request(struct bio
*bi
, int error
)
1819 struct stripe_head
*sh
= bi
->bi_private
;
1820 struct r5conf
*conf
= sh
->raid_conf
;
1821 int disks
= sh
->disks
, i
;
1822 struct md_rdev
*uninitialized_var(rdev
);
1823 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1826 int replacement
= 0;
1828 for (i
= 0 ; i
< disks
; i
++) {
1829 if (bi
== &sh
->dev
[i
].req
) {
1830 rdev
= conf
->disks
[i
].rdev
;
1833 if (bi
== &sh
->dev
[i
].rreq
) {
1834 rdev
= conf
->disks
[i
].replacement
;
1838 /* rdev was removed and 'replacement'
1839 * replaced it. rdev is not removed
1840 * until all requests are finished.
1842 rdev
= conf
->disks
[i
].rdev
;
1846 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1847 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1856 md_error(conf
->mddev
, rdev
);
1857 else if (is_badblock(rdev
, sh
->sector
,
1859 &first_bad
, &bad_sectors
))
1860 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1863 set_bit(WriteErrorSeen
, &rdev
->flags
);
1864 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1865 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1866 set_bit(MD_RECOVERY_NEEDED
,
1867 &rdev
->mddev
->recovery
);
1868 } else if (is_badblock(rdev
, sh
->sector
,
1870 &first_bad
, &bad_sectors
))
1871 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1873 rdev_dec_pending(rdev
, conf
->mddev
);
1875 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1876 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1877 set_bit(STRIPE_HANDLE
, &sh
->state
);
1881 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1883 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1885 struct r5dev
*dev
= &sh
->dev
[i
];
1887 bio_init(&dev
->req
);
1888 dev
->req
.bi_io_vec
= &dev
->vec
;
1890 dev
->req
.bi_max_vecs
++;
1891 dev
->req
.bi_private
= sh
;
1892 dev
->vec
.bv_page
= dev
->page
;
1894 bio_init(&dev
->rreq
);
1895 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1896 dev
->rreq
.bi_vcnt
++;
1897 dev
->rreq
.bi_max_vecs
++;
1898 dev
->rreq
.bi_private
= sh
;
1899 dev
->rvec
.bv_page
= dev
->page
;
1902 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1905 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1907 char b
[BDEVNAME_SIZE
];
1908 struct r5conf
*conf
= mddev
->private;
1909 unsigned long flags
;
1910 pr_debug("raid456: error called\n");
1912 spin_lock_irqsave(&conf
->device_lock
, flags
);
1913 clear_bit(In_sync
, &rdev
->flags
);
1914 mddev
->degraded
= calc_degraded(conf
);
1915 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1916 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1918 set_bit(Blocked
, &rdev
->flags
);
1919 set_bit(Faulty
, &rdev
->flags
);
1920 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1922 "md/raid:%s: Disk failure on %s, disabling device.\n"
1923 "md/raid:%s: Operation continuing on %d devices.\n",
1925 bdevname(rdev
->bdev
, b
),
1927 conf
->raid_disks
- mddev
->degraded
);
1931 * Input: a 'big' sector number,
1932 * Output: index of the data and parity disk, and the sector # in them.
1934 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1935 int previous
, int *dd_idx
,
1936 struct stripe_head
*sh
)
1938 sector_t stripe
, stripe2
;
1939 sector_t chunk_number
;
1940 unsigned int chunk_offset
;
1943 sector_t new_sector
;
1944 int algorithm
= previous
? conf
->prev_algo
1946 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1947 : conf
->chunk_sectors
;
1948 int raid_disks
= previous
? conf
->previous_raid_disks
1950 int data_disks
= raid_disks
- conf
->max_degraded
;
1952 /* First compute the information on this sector */
1955 * Compute the chunk number and the sector offset inside the chunk
1957 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1958 chunk_number
= r_sector
;
1961 * Compute the stripe number
1963 stripe
= chunk_number
;
1964 *dd_idx
= sector_div(stripe
, data_disks
);
1967 * Select the parity disk based on the user selected algorithm.
1969 pd_idx
= qd_idx
= -1;
1970 switch(conf
->level
) {
1972 pd_idx
= data_disks
;
1975 switch (algorithm
) {
1976 case ALGORITHM_LEFT_ASYMMETRIC
:
1977 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1978 if (*dd_idx
>= pd_idx
)
1981 case ALGORITHM_RIGHT_ASYMMETRIC
:
1982 pd_idx
= sector_div(stripe2
, raid_disks
);
1983 if (*dd_idx
>= pd_idx
)
1986 case ALGORITHM_LEFT_SYMMETRIC
:
1987 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1988 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1990 case ALGORITHM_RIGHT_SYMMETRIC
:
1991 pd_idx
= sector_div(stripe2
, raid_disks
);
1992 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1994 case ALGORITHM_PARITY_0
:
1998 case ALGORITHM_PARITY_N
:
1999 pd_idx
= data_disks
;
2007 switch (algorithm
) {
2008 case ALGORITHM_LEFT_ASYMMETRIC
:
2009 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2010 qd_idx
= pd_idx
+ 1;
2011 if (pd_idx
== raid_disks
-1) {
2012 (*dd_idx
)++; /* Q D D D P */
2014 } else if (*dd_idx
>= pd_idx
)
2015 (*dd_idx
) += 2; /* D D P Q D */
2017 case ALGORITHM_RIGHT_ASYMMETRIC
:
2018 pd_idx
= sector_div(stripe2
, raid_disks
);
2019 qd_idx
= pd_idx
+ 1;
2020 if (pd_idx
== raid_disks
-1) {
2021 (*dd_idx
)++; /* Q D D D P */
2023 } else if (*dd_idx
>= pd_idx
)
2024 (*dd_idx
) += 2; /* D D P Q D */
2026 case ALGORITHM_LEFT_SYMMETRIC
:
2027 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2028 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2029 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2031 case ALGORITHM_RIGHT_SYMMETRIC
:
2032 pd_idx
= sector_div(stripe2
, raid_disks
);
2033 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2034 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2037 case ALGORITHM_PARITY_0
:
2042 case ALGORITHM_PARITY_N
:
2043 pd_idx
= data_disks
;
2044 qd_idx
= data_disks
+ 1;
2047 case ALGORITHM_ROTATING_ZERO_RESTART
:
2048 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2049 * of blocks for computing Q is different.
2051 pd_idx
= sector_div(stripe2
, raid_disks
);
2052 qd_idx
= pd_idx
+ 1;
2053 if (pd_idx
== raid_disks
-1) {
2054 (*dd_idx
)++; /* Q D D D P */
2056 } else if (*dd_idx
>= pd_idx
)
2057 (*dd_idx
) += 2; /* D D P Q D */
2061 case ALGORITHM_ROTATING_N_RESTART
:
2062 /* Same a left_asymmetric, by first stripe is
2063 * D D D P Q rather than
2067 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2068 qd_idx
= pd_idx
+ 1;
2069 if (pd_idx
== raid_disks
-1) {
2070 (*dd_idx
)++; /* Q D D D P */
2072 } else if (*dd_idx
>= pd_idx
)
2073 (*dd_idx
) += 2; /* D D P Q D */
2077 case ALGORITHM_ROTATING_N_CONTINUE
:
2078 /* Same as left_symmetric but Q is before P */
2079 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2080 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2081 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2085 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2086 /* RAID5 left_asymmetric, with Q on last device */
2087 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2088 if (*dd_idx
>= pd_idx
)
2090 qd_idx
= raid_disks
- 1;
2093 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2094 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2095 if (*dd_idx
>= pd_idx
)
2097 qd_idx
= raid_disks
- 1;
2100 case ALGORITHM_LEFT_SYMMETRIC_6
:
2101 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2102 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2103 qd_idx
= raid_disks
- 1;
2106 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2107 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2108 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2109 qd_idx
= raid_disks
- 1;
2112 case ALGORITHM_PARITY_0_6
:
2115 qd_idx
= raid_disks
- 1;
2125 sh
->pd_idx
= pd_idx
;
2126 sh
->qd_idx
= qd_idx
;
2127 sh
->ddf_layout
= ddf_layout
;
2130 * Finally, compute the new sector number
2132 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2137 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2139 struct r5conf
*conf
= sh
->raid_conf
;
2140 int raid_disks
= sh
->disks
;
2141 int data_disks
= raid_disks
- conf
->max_degraded
;
2142 sector_t new_sector
= sh
->sector
, check
;
2143 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2144 : conf
->chunk_sectors
;
2145 int algorithm
= previous
? conf
->prev_algo
2149 sector_t chunk_number
;
2150 int dummy1
, dd_idx
= i
;
2152 struct stripe_head sh2
;
2155 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2156 stripe
= new_sector
;
2158 if (i
== sh
->pd_idx
)
2160 switch(conf
->level
) {
2163 switch (algorithm
) {
2164 case ALGORITHM_LEFT_ASYMMETRIC
:
2165 case ALGORITHM_RIGHT_ASYMMETRIC
:
2169 case ALGORITHM_LEFT_SYMMETRIC
:
2170 case ALGORITHM_RIGHT_SYMMETRIC
:
2173 i
-= (sh
->pd_idx
+ 1);
2175 case ALGORITHM_PARITY_0
:
2178 case ALGORITHM_PARITY_N
:
2185 if (i
== sh
->qd_idx
)
2186 return 0; /* It is the Q disk */
2187 switch (algorithm
) {
2188 case ALGORITHM_LEFT_ASYMMETRIC
:
2189 case ALGORITHM_RIGHT_ASYMMETRIC
:
2190 case ALGORITHM_ROTATING_ZERO_RESTART
:
2191 case ALGORITHM_ROTATING_N_RESTART
:
2192 if (sh
->pd_idx
== raid_disks
-1)
2193 i
--; /* Q D D D P */
2194 else if (i
> sh
->pd_idx
)
2195 i
-= 2; /* D D P Q D */
2197 case ALGORITHM_LEFT_SYMMETRIC
:
2198 case ALGORITHM_RIGHT_SYMMETRIC
:
2199 if (sh
->pd_idx
== raid_disks
-1)
2200 i
--; /* Q D D D P */
2205 i
-= (sh
->pd_idx
+ 2);
2208 case ALGORITHM_PARITY_0
:
2211 case ALGORITHM_PARITY_N
:
2213 case ALGORITHM_ROTATING_N_CONTINUE
:
2214 /* Like left_symmetric, but P is before Q */
2215 if (sh
->pd_idx
== 0)
2216 i
--; /* P D D D Q */
2221 i
-= (sh
->pd_idx
+ 1);
2224 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2225 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2229 case ALGORITHM_LEFT_SYMMETRIC_6
:
2230 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2232 i
+= data_disks
+ 1;
2233 i
-= (sh
->pd_idx
+ 1);
2235 case ALGORITHM_PARITY_0_6
:
2244 chunk_number
= stripe
* data_disks
+ i
;
2245 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2247 check
= raid5_compute_sector(conf
, r_sector
,
2248 previous
, &dummy1
, &sh2
);
2249 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2250 || sh2
.qd_idx
!= sh
->qd_idx
) {
2251 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2252 mdname(conf
->mddev
));
2260 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2261 int rcw
, int expand
)
2263 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2264 struct r5conf
*conf
= sh
->raid_conf
;
2265 int level
= conf
->level
;
2268 /* if we are not expanding this is a proper write request, and
2269 * there will be bios with new data to be drained into the
2273 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2274 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2276 sh
->reconstruct_state
= reconstruct_state_run
;
2278 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2280 for (i
= disks
; i
--; ) {
2281 struct r5dev
*dev
= &sh
->dev
[i
];
2284 set_bit(R5_LOCKED
, &dev
->flags
);
2285 set_bit(R5_Wantdrain
, &dev
->flags
);
2287 clear_bit(R5_UPTODATE
, &dev
->flags
);
2291 if (s
->locked
+ conf
->max_degraded
== disks
)
2292 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2293 atomic_inc(&conf
->pending_full_writes
);
2296 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2297 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2299 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2300 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2301 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2302 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2304 for (i
= disks
; i
--; ) {
2305 struct r5dev
*dev
= &sh
->dev
[i
];
2310 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2311 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2312 set_bit(R5_Wantdrain
, &dev
->flags
);
2313 set_bit(R5_LOCKED
, &dev
->flags
);
2314 clear_bit(R5_UPTODATE
, &dev
->flags
);
2320 /* keep the parity disk(s) locked while asynchronous operations
2323 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2324 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2328 int qd_idx
= sh
->qd_idx
;
2329 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2331 set_bit(R5_LOCKED
, &dev
->flags
);
2332 clear_bit(R5_UPTODATE
, &dev
->flags
);
2336 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2337 __func__
, (unsigned long long)sh
->sector
,
2338 s
->locked
, s
->ops_request
);
2342 * Each stripe/dev can have one or more bion attached.
2343 * toread/towrite point to the first in a chain.
2344 * The bi_next chain must be in order.
2346 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2349 struct r5conf
*conf
= sh
->raid_conf
;
2352 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2353 (unsigned long long)bi
->bi_sector
,
2354 (unsigned long long)sh
->sector
);
2357 spin_lock_irq(&conf
->device_lock
);
2359 bip
= &sh
->dev
[dd_idx
].towrite
;
2363 bip
= &sh
->dev
[dd_idx
].toread
;
2364 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2365 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2367 bip
= & (*bip
)->bi_next
;
2369 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2372 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2376 raid5_inc_bi_active_stripes(bi
);
2379 /* check if page is covered */
2380 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2381 for (bi
=sh
->dev
[dd_idx
].towrite
;
2382 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2383 bi
&& bi
->bi_sector
<= sector
;
2384 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2385 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2386 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2388 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2389 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2391 spin_unlock_irq(&conf
->device_lock
);
2393 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2394 (unsigned long long)(*bip
)->bi_sector
,
2395 (unsigned long long)sh
->sector
, dd_idx
);
2397 if (conf
->mddev
->bitmap
&& firstwrite
) {
2398 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2400 sh
->bm_seq
= conf
->seq_flush
+1;
2401 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2406 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2407 spin_unlock_irq(&conf
->device_lock
);
2411 static void end_reshape(struct r5conf
*conf
);
2413 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2414 struct stripe_head
*sh
)
2416 int sectors_per_chunk
=
2417 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2419 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2420 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2422 raid5_compute_sector(conf
,
2423 stripe
* (disks
- conf
->max_degraded
)
2424 *sectors_per_chunk
+ chunk_offset
,
2430 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2431 struct stripe_head_state
*s
, int disks
,
2432 struct bio
**return_bi
)
2435 for (i
= disks
; i
--; ) {
2439 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2440 struct md_rdev
*rdev
;
2442 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2443 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2444 atomic_inc(&rdev
->nr_pending
);
2449 if (!rdev_set_badblocks(
2453 md_error(conf
->mddev
, rdev
);
2454 rdev_dec_pending(rdev
, conf
->mddev
);
2457 spin_lock_irq(&conf
->device_lock
);
2458 /* fail all writes first */
2459 bi
= sh
->dev
[i
].towrite
;
2460 sh
->dev
[i
].towrite
= NULL
;
2461 spin_unlock_irq(&conf
->device_lock
);
2467 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2468 wake_up(&conf
->wait_for_overlap
);
2470 while (bi
&& bi
->bi_sector
<
2471 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2472 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2473 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2474 if (!raid5_dec_bi_active_stripes(bi
)) {
2475 md_write_end(conf
->mddev
);
2476 bi
->bi_next
= *return_bi
;
2482 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2483 STRIPE_SECTORS
, 0, 0);
2485 /* and fail all 'written' */
2486 bi
= sh
->dev
[i
].written
;
2487 sh
->dev
[i
].written
= NULL
;
2488 if (bi
) bitmap_end
= 1;
2489 while (bi
&& bi
->bi_sector
<
2490 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2491 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2492 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2493 if (!raid5_dec_bi_active_stripes(bi
)) {
2494 md_write_end(conf
->mddev
);
2495 bi
->bi_next
= *return_bi
;
2501 /* fail any reads if this device is non-operational and
2502 * the data has not reached the cache yet.
2504 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2505 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2506 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2507 bi
= sh
->dev
[i
].toread
;
2508 sh
->dev
[i
].toread
= NULL
;
2509 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2510 wake_up(&conf
->wait_for_overlap
);
2511 if (bi
) s
->to_read
--;
2512 while (bi
&& bi
->bi_sector
<
2513 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2514 struct bio
*nextbi
=
2515 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2516 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2517 if (!raid5_dec_bi_active_stripes(bi
)) {
2518 bi
->bi_next
= *return_bi
;
2525 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2526 STRIPE_SECTORS
, 0, 0);
2527 /* If we were in the middle of a write the parity block might
2528 * still be locked - so just clear all R5_LOCKED flags
2530 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2533 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2534 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2535 md_wakeup_thread(conf
->mddev
->thread
);
2539 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2540 struct stripe_head_state
*s
)
2545 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2548 /* There is nothing more to do for sync/check/repair.
2549 * Don't even need to abort as that is handled elsewhere
2550 * if needed, and not always wanted e.g. if there is a known
2552 * For recover/replace we need to record a bad block on all
2553 * non-sync devices, or abort the recovery
2555 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2556 /* During recovery devices cannot be removed, so
2557 * locking and refcounting of rdevs is not needed
2559 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2560 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2562 && !test_bit(Faulty
, &rdev
->flags
)
2563 && !test_bit(In_sync
, &rdev
->flags
)
2564 && !rdev_set_badblocks(rdev
, sh
->sector
,
2567 rdev
= conf
->disks
[i
].replacement
;
2569 && !test_bit(Faulty
, &rdev
->flags
)
2570 && !test_bit(In_sync
, &rdev
->flags
)
2571 && !rdev_set_badblocks(rdev
, sh
->sector
,
2576 conf
->recovery_disabled
=
2577 conf
->mddev
->recovery_disabled
;
2579 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2582 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2584 struct md_rdev
*rdev
;
2586 /* Doing recovery so rcu locking not required */
2587 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2589 && !test_bit(Faulty
, &rdev
->flags
)
2590 && !test_bit(In_sync
, &rdev
->flags
)
2591 && (rdev
->recovery_offset
<= sh
->sector
2592 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2598 /* fetch_block - checks the given member device to see if its data needs
2599 * to be read or computed to satisfy a request.
2601 * Returns 1 when no more member devices need to be checked, otherwise returns
2602 * 0 to tell the loop in handle_stripe_fill to continue
2604 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2605 int disk_idx
, int disks
)
2607 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2608 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2609 &sh
->dev
[s
->failed_num
[1]] };
2611 /* is the data in this block needed, and can we get it? */
2612 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2613 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2615 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2616 s
->syncing
|| s
->expanding
||
2617 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2618 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2619 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2620 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2621 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2622 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2623 /* we would like to get this block, possibly by computing it,
2624 * otherwise read it if the backing disk is insync
2626 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2627 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2628 if ((s
->uptodate
== disks
- 1) &&
2629 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2630 disk_idx
== s
->failed_num
[1]))) {
2631 /* have disk failed, and we're requested to fetch it;
2634 pr_debug("Computing stripe %llu block %d\n",
2635 (unsigned long long)sh
->sector
, disk_idx
);
2636 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2637 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2638 set_bit(R5_Wantcompute
, &dev
->flags
);
2639 sh
->ops
.target
= disk_idx
;
2640 sh
->ops
.target2
= -1; /* no 2nd target */
2642 /* Careful: from this point on 'uptodate' is in the eye
2643 * of raid_run_ops which services 'compute' operations
2644 * before writes. R5_Wantcompute flags a block that will
2645 * be R5_UPTODATE by the time it is needed for a
2646 * subsequent operation.
2650 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2651 /* Computing 2-failure is *very* expensive; only
2652 * do it if failed >= 2
2655 for (other
= disks
; other
--; ) {
2656 if (other
== disk_idx
)
2658 if (!test_bit(R5_UPTODATE
,
2659 &sh
->dev
[other
].flags
))
2663 pr_debug("Computing stripe %llu blocks %d,%d\n",
2664 (unsigned long long)sh
->sector
,
2666 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2667 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2668 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2669 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2670 sh
->ops
.target
= disk_idx
;
2671 sh
->ops
.target2
= other
;
2675 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2676 set_bit(R5_LOCKED
, &dev
->flags
);
2677 set_bit(R5_Wantread
, &dev
->flags
);
2679 pr_debug("Reading block %d (sync=%d)\n",
2680 disk_idx
, s
->syncing
);
2688 * handle_stripe_fill - read or compute data to satisfy pending requests.
2690 static void handle_stripe_fill(struct stripe_head
*sh
,
2691 struct stripe_head_state
*s
,
2696 /* look for blocks to read/compute, skip this if a compute
2697 * is already in flight, or if the stripe contents are in the
2698 * midst of changing due to a write
2700 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2701 !sh
->reconstruct_state
)
2702 for (i
= disks
; i
--; )
2703 if (fetch_block(sh
, s
, i
, disks
))
2705 set_bit(STRIPE_HANDLE
, &sh
->state
);
2709 /* handle_stripe_clean_event
2710 * any written block on an uptodate or failed drive can be returned.
2711 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2712 * never LOCKED, so we don't need to test 'failed' directly.
2714 static void handle_stripe_clean_event(struct r5conf
*conf
,
2715 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2720 for (i
= disks
; i
--; )
2721 if (sh
->dev
[i
].written
) {
2723 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2724 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2725 /* We can return any write requests */
2726 struct bio
*wbi
, *wbi2
;
2727 pr_debug("Return write for disc %d\n", i
);
2729 dev
->written
= NULL
;
2730 while (wbi
&& wbi
->bi_sector
<
2731 dev
->sector
+ STRIPE_SECTORS
) {
2732 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2733 if (!raid5_dec_bi_active_stripes(wbi
)) {
2734 md_write_end(conf
->mddev
);
2735 wbi
->bi_next
= *return_bi
;
2740 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2742 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2747 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2748 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2749 md_wakeup_thread(conf
->mddev
->thread
);
2752 static void handle_stripe_dirtying(struct r5conf
*conf
,
2753 struct stripe_head
*sh
,
2754 struct stripe_head_state
*s
,
2757 int rmw
= 0, rcw
= 0, i
;
2758 if (conf
->max_degraded
== 2) {
2759 /* RAID6 requires 'rcw' in current implementation
2760 * Calculate the real rcw later - for now fake it
2761 * look like rcw is cheaper
2764 } else for (i
= disks
; i
--; ) {
2765 /* would I have to read this buffer for read_modify_write */
2766 struct r5dev
*dev
= &sh
->dev
[i
];
2767 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2768 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2769 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2770 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2771 if (test_bit(R5_Insync
, &dev
->flags
))
2774 rmw
+= 2*disks
; /* cannot read it */
2776 /* Would I have to read this buffer for reconstruct_write */
2777 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2778 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2779 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2780 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2781 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2786 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2787 (unsigned long long)sh
->sector
, rmw
, rcw
);
2788 set_bit(STRIPE_HANDLE
, &sh
->state
);
2789 if (rmw
< rcw
&& rmw
> 0)
2790 /* prefer read-modify-write, but need to get some data */
2791 for (i
= disks
; i
--; ) {
2792 struct r5dev
*dev
= &sh
->dev
[i
];
2793 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2794 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2795 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2796 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2797 test_bit(R5_Insync
, &dev
->flags
)) {
2799 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2800 pr_debug("Read_old block "
2801 "%d for r-m-w\n", i
);
2802 set_bit(R5_LOCKED
, &dev
->flags
);
2803 set_bit(R5_Wantread
, &dev
->flags
);
2806 set_bit(STRIPE_DELAYED
, &sh
->state
);
2807 set_bit(STRIPE_HANDLE
, &sh
->state
);
2811 if (rcw
<= rmw
&& rcw
> 0) {
2812 /* want reconstruct write, but need to get some data */
2814 for (i
= disks
; i
--; ) {
2815 struct r5dev
*dev
= &sh
->dev
[i
];
2816 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2817 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2818 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2819 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2820 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2822 if (!test_bit(R5_Insync
, &dev
->flags
))
2823 continue; /* it's a failed drive */
2825 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2826 pr_debug("Read_old block "
2827 "%d for Reconstruct\n", i
);
2828 set_bit(R5_LOCKED
, &dev
->flags
);
2829 set_bit(R5_Wantread
, &dev
->flags
);
2832 set_bit(STRIPE_DELAYED
, &sh
->state
);
2833 set_bit(STRIPE_HANDLE
, &sh
->state
);
2838 /* now if nothing is locked, and if we have enough data,
2839 * we can start a write request
2841 /* since handle_stripe can be called at any time we need to handle the
2842 * case where a compute block operation has been submitted and then a
2843 * subsequent call wants to start a write request. raid_run_ops only
2844 * handles the case where compute block and reconstruct are requested
2845 * simultaneously. If this is not the case then new writes need to be
2846 * held off until the compute completes.
2848 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2849 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2850 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2851 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2854 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2855 struct stripe_head_state
*s
, int disks
)
2857 struct r5dev
*dev
= NULL
;
2859 set_bit(STRIPE_HANDLE
, &sh
->state
);
2861 switch (sh
->check_state
) {
2862 case check_state_idle
:
2863 /* start a new check operation if there are no failures */
2864 if (s
->failed
== 0) {
2865 BUG_ON(s
->uptodate
!= disks
);
2866 sh
->check_state
= check_state_run
;
2867 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2868 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2872 dev
= &sh
->dev
[s
->failed_num
[0]];
2874 case check_state_compute_result
:
2875 sh
->check_state
= check_state_idle
;
2877 dev
= &sh
->dev
[sh
->pd_idx
];
2879 /* check that a write has not made the stripe insync */
2880 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2883 /* either failed parity check, or recovery is happening */
2884 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2885 BUG_ON(s
->uptodate
!= disks
);
2887 set_bit(R5_LOCKED
, &dev
->flags
);
2889 set_bit(R5_Wantwrite
, &dev
->flags
);
2891 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2892 set_bit(STRIPE_INSYNC
, &sh
->state
);
2894 case check_state_run
:
2895 break; /* we will be called again upon completion */
2896 case check_state_check_result
:
2897 sh
->check_state
= check_state_idle
;
2899 /* if a failure occurred during the check operation, leave
2900 * STRIPE_INSYNC not set and let the stripe be handled again
2905 /* handle a successful check operation, if parity is correct
2906 * we are done. Otherwise update the mismatch count and repair
2907 * parity if !MD_RECOVERY_CHECK
2909 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2910 /* parity is correct (on disc,
2911 * not in buffer any more)
2913 set_bit(STRIPE_INSYNC
, &sh
->state
);
2915 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2916 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2917 /* don't try to repair!! */
2918 set_bit(STRIPE_INSYNC
, &sh
->state
);
2920 sh
->check_state
= check_state_compute_run
;
2921 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2922 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2923 set_bit(R5_Wantcompute
,
2924 &sh
->dev
[sh
->pd_idx
].flags
);
2925 sh
->ops
.target
= sh
->pd_idx
;
2926 sh
->ops
.target2
= -1;
2931 case check_state_compute_run
:
2934 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2935 __func__
, sh
->check_state
,
2936 (unsigned long long) sh
->sector
);
2942 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
2943 struct stripe_head_state
*s
,
2946 int pd_idx
= sh
->pd_idx
;
2947 int qd_idx
= sh
->qd_idx
;
2950 set_bit(STRIPE_HANDLE
, &sh
->state
);
2952 BUG_ON(s
->failed
> 2);
2954 /* Want to check and possibly repair P and Q.
2955 * However there could be one 'failed' device, in which
2956 * case we can only check one of them, possibly using the
2957 * other to generate missing data
2960 switch (sh
->check_state
) {
2961 case check_state_idle
:
2962 /* start a new check operation if there are < 2 failures */
2963 if (s
->failed
== s
->q_failed
) {
2964 /* The only possible failed device holds Q, so it
2965 * makes sense to check P (If anything else were failed,
2966 * we would have used P to recreate it).
2968 sh
->check_state
= check_state_run
;
2970 if (!s
->q_failed
&& s
->failed
< 2) {
2971 /* Q is not failed, and we didn't use it to generate
2972 * anything, so it makes sense to check it
2974 if (sh
->check_state
== check_state_run
)
2975 sh
->check_state
= check_state_run_pq
;
2977 sh
->check_state
= check_state_run_q
;
2980 /* discard potentially stale zero_sum_result */
2981 sh
->ops
.zero_sum_result
= 0;
2983 if (sh
->check_state
== check_state_run
) {
2984 /* async_xor_zero_sum destroys the contents of P */
2985 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2988 if (sh
->check_state
>= check_state_run
&&
2989 sh
->check_state
<= check_state_run_pq
) {
2990 /* async_syndrome_zero_sum preserves P and Q, so
2991 * no need to mark them !uptodate here
2993 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2997 /* we have 2-disk failure */
2998 BUG_ON(s
->failed
!= 2);
3000 case check_state_compute_result
:
3001 sh
->check_state
= check_state_idle
;
3003 /* check that a write has not made the stripe insync */
3004 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3007 /* now write out any block on a failed drive,
3008 * or P or Q if they were recomputed
3010 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3011 if (s
->failed
== 2) {
3012 dev
= &sh
->dev
[s
->failed_num
[1]];
3014 set_bit(R5_LOCKED
, &dev
->flags
);
3015 set_bit(R5_Wantwrite
, &dev
->flags
);
3017 if (s
->failed
>= 1) {
3018 dev
= &sh
->dev
[s
->failed_num
[0]];
3020 set_bit(R5_LOCKED
, &dev
->flags
);
3021 set_bit(R5_Wantwrite
, &dev
->flags
);
3023 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3024 dev
= &sh
->dev
[pd_idx
];
3026 set_bit(R5_LOCKED
, &dev
->flags
);
3027 set_bit(R5_Wantwrite
, &dev
->flags
);
3029 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3030 dev
= &sh
->dev
[qd_idx
];
3032 set_bit(R5_LOCKED
, &dev
->flags
);
3033 set_bit(R5_Wantwrite
, &dev
->flags
);
3035 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3037 set_bit(STRIPE_INSYNC
, &sh
->state
);
3039 case check_state_run
:
3040 case check_state_run_q
:
3041 case check_state_run_pq
:
3042 break; /* we will be called again upon completion */
3043 case check_state_check_result
:
3044 sh
->check_state
= check_state_idle
;
3046 /* handle a successful check operation, if parity is correct
3047 * we are done. Otherwise update the mismatch count and repair
3048 * parity if !MD_RECOVERY_CHECK
3050 if (sh
->ops
.zero_sum_result
== 0) {
3051 /* both parities are correct */
3053 set_bit(STRIPE_INSYNC
, &sh
->state
);
3055 /* in contrast to the raid5 case we can validate
3056 * parity, but still have a failure to write
3059 sh
->check_state
= check_state_compute_result
;
3060 /* Returning at this point means that we may go
3061 * off and bring p and/or q uptodate again so
3062 * we make sure to check zero_sum_result again
3063 * to verify if p or q need writeback
3067 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
3068 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3069 /* don't try to repair!! */
3070 set_bit(STRIPE_INSYNC
, &sh
->state
);
3072 int *target
= &sh
->ops
.target
;
3074 sh
->ops
.target
= -1;
3075 sh
->ops
.target2
= -1;
3076 sh
->check_state
= check_state_compute_run
;
3077 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3078 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3079 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3080 set_bit(R5_Wantcompute
,
3081 &sh
->dev
[pd_idx
].flags
);
3083 target
= &sh
->ops
.target2
;
3086 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3087 set_bit(R5_Wantcompute
,
3088 &sh
->dev
[qd_idx
].flags
);
3095 case check_state_compute_run
:
3098 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3099 __func__
, sh
->check_state
,
3100 (unsigned long long) sh
->sector
);
3105 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3109 /* We have read all the blocks in this stripe and now we need to
3110 * copy some of them into a target stripe for expand.
3112 struct dma_async_tx_descriptor
*tx
= NULL
;
3113 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3114 for (i
= 0; i
< sh
->disks
; i
++)
3115 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3117 struct stripe_head
*sh2
;
3118 struct async_submit_ctl submit
;
3120 sector_t bn
= compute_blocknr(sh
, i
, 1);
3121 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3123 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3125 /* so far only the early blocks of this stripe
3126 * have been requested. When later blocks
3127 * get requested, we will try again
3130 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3131 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3132 /* must have already done this block */
3133 release_stripe(sh2
);
3137 /* place all the copies on one channel */
3138 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3139 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3140 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3143 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3144 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3145 for (j
= 0; j
< conf
->raid_disks
; j
++)
3146 if (j
!= sh2
->pd_idx
&&
3148 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3150 if (j
== conf
->raid_disks
) {
3151 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3152 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3154 release_stripe(sh2
);
3157 /* done submitting copies, wait for them to complete */
3160 dma_wait_for_async_tx(tx
);
3165 * handle_stripe - do things to a stripe.
3167 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3168 * state of various bits to see what needs to be done.
3170 * return some read requests which now have data
3171 * return some write requests which are safely on storage
3172 * schedule a read on some buffers
3173 * schedule a write of some buffers
3174 * return confirmation of parity correctness
3178 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3180 struct r5conf
*conf
= sh
->raid_conf
;
3181 int disks
= sh
->disks
;
3184 int do_recovery
= 0;
3186 memset(s
, 0, sizeof(*s
));
3188 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3189 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3190 s
->failed_num
[0] = -1;
3191 s
->failed_num
[1] = -1;
3193 /* Now to look around and see what can be done */
3195 spin_lock_irq(&conf
->device_lock
);
3196 for (i
=disks
; i
--; ) {
3197 struct md_rdev
*rdev
;
3204 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3206 dev
->toread
, dev
->towrite
, dev
->written
);
3207 /* maybe we can reply to a read
3209 * new wantfill requests are only permitted while
3210 * ops_complete_biofill is guaranteed to be inactive
3212 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3213 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3214 set_bit(R5_Wantfill
, &dev
->flags
);
3216 /* now count some things */
3217 if (test_bit(R5_LOCKED
, &dev
->flags
))
3219 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3221 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3223 BUG_ON(s
->compute
> 2);
3226 if (test_bit(R5_Wantfill
, &dev
->flags
))
3228 else if (dev
->toread
)
3232 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3237 /* Prefer to use the replacement for reads, but only
3238 * if it is recovered enough and has no bad blocks.
3240 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3241 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3242 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3243 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3244 &first_bad
, &bad_sectors
))
3245 set_bit(R5_ReadRepl
, &dev
->flags
);
3248 set_bit(R5_NeedReplace
, &dev
->flags
);
3249 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3250 clear_bit(R5_ReadRepl
, &dev
->flags
);
3252 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3255 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3256 &first_bad
, &bad_sectors
);
3257 if (s
->blocked_rdev
== NULL
3258 && (test_bit(Blocked
, &rdev
->flags
)
3261 set_bit(BlockedBadBlocks
,
3263 s
->blocked_rdev
= rdev
;
3264 atomic_inc(&rdev
->nr_pending
);
3267 clear_bit(R5_Insync
, &dev
->flags
);
3271 /* also not in-sync */
3272 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3273 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3274 /* treat as in-sync, but with a read error
3275 * which we can now try to correct
3277 set_bit(R5_Insync
, &dev
->flags
);
3278 set_bit(R5_ReadError
, &dev
->flags
);
3280 } else if (test_bit(In_sync
, &rdev
->flags
))
3281 set_bit(R5_Insync
, &dev
->flags
);
3282 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3283 /* in sync if before recovery_offset */
3284 set_bit(R5_Insync
, &dev
->flags
);
3285 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3286 test_bit(R5_Expanded
, &dev
->flags
))
3287 /* If we've reshaped into here, we assume it is Insync.
3288 * We will shortly update recovery_offset to make
3291 set_bit(R5_Insync
, &dev
->flags
);
3293 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3294 /* This flag does not apply to '.replacement'
3295 * only to .rdev, so make sure to check that*/
3296 struct md_rdev
*rdev2
= rcu_dereference(
3297 conf
->disks
[i
].rdev
);
3299 clear_bit(R5_Insync
, &dev
->flags
);
3300 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3301 s
->handle_bad_blocks
= 1;
3302 atomic_inc(&rdev2
->nr_pending
);
3304 clear_bit(R5_WriteError
, &dev
->flags
);
3306 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3307 /* This flag does not apply to '.replacement'
3308 * only to .rdev, so make sure to check that*/
3309 struct md_rdev
*rdev2
= rcu_dereference(
3310 conf
->disks
[i
].rdev
);
3311 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3312 s
->handle_bad_blocks
= 1;
3313 atomic_inc(&rdev2
->nr_pending
);
3315 clear_bit(R5_MadeGood
, &dev
->flags
);
3317 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3318 struct md_rdev
*rdev2
= rcu_dereference(
3319 conf
->disks
[i
].replacement
);
3320 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3321 s
->handle_bad_blocks
= 1;
3322 atomic_inc(&rdev2
->nr_pending
);
3324 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3326 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3327 /* The ReadError flag will just be confusing now */
3328 clear_bit(R5_ReadError
, &dev
->flags
);
3329 clear_bit(R5_ReWrite
, &dev
->flags
);
3331 if (test_bit(R5_ReadError
, &dev
->flags
))
3332 clear_bit(R5_Insync
, &dev
->flags
);
3333 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3335 s
->failed_num
[s
->failed
] = i
;
3337 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3341 spin_unlock_irq(&conf
->device_lock
);
3342 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3343 /* If there is a failed device being replaced,
3344 * we must be recovering.
3345 * else if we are after recovery_cp, we must be syncing
3346 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3347 * else we can only be replacing
3348 * sync and recovery both need to read all devices, and so
3349 * use the same flag.
3352 sh
->sector
>= conf
->mddev
->recovery_cp
||
3353 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3361 static void handle_stripe(struct stripe_head
*sh
)
3363 struct stripe_head_state s
;
3364 struct r5conf
*conf
= sh
->raid_conf
;
3367 int disks
= sh
->disks
;
3368 struct r5dev
*pdev
, *qdev
;
3370 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3371 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3372 /* already being handled, ensure it gets handled
3373 * again when current action finishes */
3374 set_bit(STRIPE_HANDLE
, &sh
->state
);
3378 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3379 set_bit(STRIPE_SYNCING
, &sh
->state
);
3380 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3382 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3384 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3385 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3386 (unsigned long long)sh
->sector
, sh
->state
,
3387 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3388 sh
->check_state
, sh
->reconstruct_state
);
3390 analyse_stripe(sh
, &s
);
3392 if (s
.handle_bad_blocks
) {
3393 set_bit(STRIPE_HANDLE
, &sh
->state
);
3397 if (unlikely(s
.blocked_rdev
)) {
3398 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3399 s
.replacing
|| s
.to_write
|| s
.written
) {
3400 set_bit(STRIPE_HANDLE
, &sh
->state
);
3403 /* There is nothing for the blocked_rdev to block */
3404 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3405 s
.blocked_rdev
= NULL
;
3408 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3409 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3410 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3413 pr_debug("locked=%d uptodate=%d to_read=%d"
3414 " to_write=%d failed=%d failed_num=%d,%d\n",
3415 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3416 s
.failed_num
[0], s
.failed_num
[1]);
3417 /* check if the array has lost more than max_degraded devices and,
3418 * if so, some requests might need to be failed.
3420 if (s
.failed
> conf
->max_degraded
) {
3421 sh
->check_state
= 0;
3422 sh
->reconstruct_state
= 0;
3423 if (s
.to_read
+s
.to_write
+s
.written
)
3424 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3425 if (s
.syncing
+ s
.replacing
)
3426 handle_failed_sync(conf
, sh
, &s
);
3430 * might be able to return some write requests if the parity blocks
3431 * are safe, or on a failed drive
3433 pdev
= &sh
->dev
[sh
->pd_idx
];
3434 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3435 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3436 qdev
= &sh
->dev
[sh
->qd_idx
];
3437 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3438 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3442 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3443 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3444 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3445 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3446 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3447 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3448 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3450 /* Now we might consider reading some blocks, either to check/generate
3451 * parity, or to satisfy requests
3452 * or to load a block that is being partially written.
3454 if (s
.to_read
|| s
.non_overwrite
3455 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3456 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3459 handle_stripe_fill(sh
, &s
, disks
);
3461 /* Now we check to see if any write operations have recently
3465 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3467 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3468 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3469 sh
->reconstruct_state
= reconstruct_state_idle
;
3471 /* All the 'written' buffers and the parity block are ready to
3472 * be written back to disk
3474 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3475 BUG_ON(sh
->qd_idx
>= 0 &&
3476 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
));
3477 for (i
= disks
; i
--; ) {
3478 struct r5dev
*dev
= &sh
->dev
[i
];
3479 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3480 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3482 pr_debug("Writing block %d\n", i
);
3483 set_bit(R5_Wantwrite
, &dev
->flags
);
3486 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3487 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3489 set_bit(STRIPE_INSYNC
, &sh
->state
);
3492 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3493 s
.dec_preread_active
= 1;
3496 /* Now to consider new write requests and what else, if anything
3497 * should be read. We do not handle new writes when:
3498 * 1/ A 'write' operation (copy+xor) is already in flight.
3499 * 2/ A 'check' operation is in flight, as it may clobber the parity
3502 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3503 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3505 /* maybe we need to check and possibly fix the parity for this stripe
3506 * Any reads will already have been scheduled, so we just see if enough
3507 * data is available. The parity check is held off while parity
3508 * dependent operations are in flight.
3510 if (sh
->check_state
||
3511 (s
.syncing
&& s
.locked
== 0 &&
3512 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3513 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3514 if (conf
->level
== 6)
3515 handle_parity_checks6(conf
, sh
, &s
, disks
);
3517 handle_parity_checks5(conf
, sh
, &s
, disks
);
3520 if (s
.replacing
&& s
.locked
== 0
3521 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3522 /* Write out to replacement devices where possible */
3523 for (i
= 0; i
< conf
->raid_disks
; i
++)
3524 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3525 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3526 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3527 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3530 set_bit(STRIPE_INSYNC
, &sh
->state
);
3532 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3533 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3534 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3535 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3538 /* If the failed drives are just a ReadError, then we might need
3539 * to progress the repair/check process
3541 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3542 for (i
= 0; i
< s
.failed
; i
++) {
3543 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3544 if (test_bit(R5_ReadError
, &dev
->flags
)
3545 && !test_bit(R5_LOCKED
, &dev
->flags
)
3546 && test_bit(R5_UPTODATE
, &dev
->flags
)
3548 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3549 set_bit(R5_Wantwrite
, &dev
->flags
);
3550 set_bit(R5_ReWrite
, &dev
->flags
);
3551 set_bit(R5_LOCKED
, &dev
->flags
);
3554 /* let's read it back */
3555 set_bit(R5_Wantread
, &dev
->flags
);
3556 set_bit(R5_LOCKED
, &dev
->flags
);
3563 /* Finish reconstruct operations initiated by the expansion process */
3564 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3565 struct stripe_head
*sh_src
3566 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3567 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3568 /* sh cannot be written until sh_src has been read.
3569 * so arrange for sh to be delayed a little
3571 set_bit(STRIPE_DELAYED
, &sh
->state
);
3572 set_bit(STRIPE_HANDLE
, &sh
->state
);
3573 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3575 atomic_inc(&conf
->preread_active_stripes
);
3576 release_stripe(sh_src
);
3580 release_stripe(sh_src
);
3582 sh
->reconstruct_state
= reconstruct_state_idle
;
3583 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3584 for (i
= conf
->raid_disks
; i
--; ) {
3585 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3586 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3591 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3592 !sh
->reconstruct_state
) {
3593 /* Need to write out all blocks after computing parity */
3594 sh
->disks
= conf
->raid_disks
;
3595 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3596 schedule_reconstruction(sh
, &s
, 1, 1);
3597 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3598 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3599 atomic_dec(&conf
->reshape_stripes
);
3600 wake_up(&conf
->wait_for_overlap
);
3601 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3604 if (s
.expanding
&& s
.locked
== 0 &&
3605 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3606 handle_stripe_expansion(conf
, sh
);
3609 /* wait for this device to become unblocked */
3610 if (unlikely(s
.blocked_rdev
)) {
3611 if (conf
->mddev
->external
)
3612 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3615 /* Internal metadata will immediately
3616 * be written by raid5d, so we don't
3617 * need to wait here.
3619 rdev_dec_pending(s
.blocked_rdev
,
3623 if (s
.handle_bad_blocks
)
3624 for (i
= disks
; i
--; ) {
3625 struct md_rdev
*rdev
;
3626 struct r5dev
*dev
= &sh
->dev
[i
];
3627 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3628 /* We own a safe reference to the rdev */
3629 rdev
= conf
->disks
[i
].rdev
;
3630 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3632 md_error(conf
->mddev
, rdev
);
3633 rdev_dec_pending(rdev
, conf
->mddev
);
3635 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3636 rdev
= conf
->disks
[i
].rdev
;
3637 rdev_clear_badblocks(rdev
, sh
->sector
,
3639 rdev_dec_pending(rdev
, conf
->mddev
);
3641 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3642 rdev
= conf
->disks
[i
].replacement
;
3644 /* rdev have been moved down */
3645 rdev
= conf
->disks
[i
].rdev
;
3646 rdev_clear_badblocks(rdev
, sh
->sector
,
3648 rdev_dec_pending(rdev
, conf
->mddev
);
3653 raid_run_ops(sh
, s
.ops_request
);
3657 if (s
.dec_preread_active
) {
3658 /* We delay this until after ops_run_io so that if make_request
3659 * is waiting on a flush, it won't continue until the writes
3660 * have actually been submitted.
3662 atomic_dec(&conf
->preread_active_stripes
);
3663 if (atomic_read(&conf
->preread_active_stripes
) <
3665 md_wakeup_thread(conf
->mddev
->thread
);
3668 return_io(s
.return_bi
);
3670 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3673 static void raid5_activate_delayed(struct r5conf
*conf
)
3675 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3676 while (!list_empty(&conf
->delayed_list
)) {
3677 struct list_head
*l
= conf
->delayed_list
.next
;
3678 struct stripe_head
*sh
;
3679 sh
= list_entry(l
, struct stripe_head
, lru
);
3681 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3682 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3683 atomic_inc(&conf
->preread_active_stripes
);
3684 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3689 static void activate_bit_delay(struct r5conf
*conf
)
3691 /* device_lock is held */
3692 struct list_head head
;
3693 list_add(&head
, &conf
->bitmap_list
);
3694 list_del_init(&conf
->bitmap_list
);
3695 while (!list_empty(&head
)) {
3696 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3697 list_del_init(&sh
->lru
);
3698 atomic_inc(&sh
->count
);
3699 __release_stripe(conf
, sh
);
3703 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3705 struct r5conf
*conf
= mddev
->private;
3707 /* No difference between reads and writes. Just check
3708 * how busy the stripe_cache is
3711 if (conf
->inactive_blocked
)
3715 if (list_empty_careful(&conf
->inactive_list
))
3720 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3722 static int raid5_congested(void *data
, int bits
)
3724 struct mddev
*mddev
= data
;
3726 return mddev_congested(mddev
, bits
) ||
3727 md_raid5_congested(mddev
, bits
);
3730 /* We want read requests to align with chunks where possible,
3731 * but write requests don't need to.
3733 static int raid5_mergeable_bvec(struct request_queue
*q
,
3734 struct bvec_merge_data
*bvm
,
3735 struct bio_vec
*biovec
)
3737 struct mddev
*mddev
= q
->queuedata
;
3738 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3740 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3741 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3743 if ((bvm
->bi_rw
& 1) == WRITE
)
3744 return biovec
->bv_len
; /* always allow writes to be mergeable */
3746 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3747 chunk_sectors
= mddev
->new_chunk_sectors
;
3748 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3749 if (max
< 0) max
= 0;
3750 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3751 return biovec
->bv_len
;
3757 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3759 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3760 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3761 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3763 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3764 chunk_sectors
= mddev
->new_chunk_sectors
;
3765 return chunk_sectors
>=
3766 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3770 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3771 * later sampled by raid5d.
3773 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3775 unsigned long flags
;
3777 spin_lock_irqsave(&conf
->device_lock
, flags
);
3779 bi
->bi_next
= conf
->retry_read_aligned_list
;
3780 conf
->retry_read_aligned_list
= bi
;
3782 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3783 md_wakeup_thread(conf
->mddev
->thread
);
3787 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3791 bi
= conf
->retry_read_aligned
;
3793 conf
->retry_read_aligned
= NULL
;
3796 bi
= conf
->retry_read_aligned_list
;
3798 conf
->retry_read_aligned_list
= bi
->bi_next
;
3801 * this sets the active strip count to 1 and the processed
3802 * strip count to zero (upper 8 bits)
3804 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3812 * The "raid5_align_endio" should check if the read succeeded and if it
3813 * did, call bio_endio on the original bio (having bio_put the new bio
3815 * If the read failed..
3817 static void raid5_align_endio(struct bio
*bi
, int error
)
3819 struct bio
* raid_bi
= bi
->bi_private
;
3820 struct mddev
*mddev
;
3821 struct r5conf
*conf
;
3822 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3823 struct md_rdev
*rdev
;
3827 rdev
= (void*)raid_bi
->bi_next
;
3828 raid_bi
->bi_next
= NULL
;
3829 mddev
= rdev
->mddev
;
3830 conf
= mddev
->private;
3832 rdev_dec_pending(rdev
, conf
->mddev
);
3834 if (!error
&& uptodate
) {
3835 bio_endio(raid_bi
, 0);
3836 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3837 wake_up(&conf
->wait_for_stripe
);
3842 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3844 add_bio_to_retry(raid_bi
, conf
);
3847 static int bio_fits_rdev(struct bio
*bi
)
3849 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3851 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3853 blk_recount_segments(q
, bi
);
3854 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3857 if (q
->merge_bvec_fn
)
3858 /* it's too hard to apply the merge_bvec_fn at this stage,
3867 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3869 struct r5conf
*conf
= mddev
->private;
3871 struct bio
* align_bi
;
3872 struct md_rdev
*rdev
;
3873 sector_t end_sector
;
3875 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3876 pr_debug("chunk_aligned_read : non aligned\n");
3880 * use bio_clone_mddev to make a copy of the bio
3882 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3886 * set bi_end_io to a new function, and set bi_private to the
3889 align_bi
->bi_end_io
= raid5_align_endio
;
3890 align_bi
->bi_private
= raid_bio
;
3894 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3898 end_sector
= align_bi
->bi_sector
+ (align_bi
->bi_size
>> 9);
3900 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3901 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3902 rdev
->recovery_offset
< end_sector
) {
3903 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3905 (test_bit(Faulty
, &rdev
->flags
) ||
3906 !(test_bit(In_sync
, &rdev
->flags
) ||
3907 rdev
->recovery_offset
>= end_sector
)))
3914 atomic_inc(&rdev
->nr_pending
);
3916 raid_bio
->bi_next
= (void*)rdev
;
3917 align_bi
->bi_bdev
= rdev
->bdev
;
3918 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3920 if (!bio_fits_rdev(align_bi
) ||
3921 is_badblock(rdev
, align_bi
->bi_sector
, align_bi
->bi_size
>>9,
3922 &first_bad
, &bad_sectors
)) {
3923 /* too big in some way, or has a known bad block */
3925 rdev_dec_pending(rdev
, mddev
);
3929 /* No reshape active, so we can trust rdev->data_offset */
3930 align_bi
->bi_sector
+= rdev
->data_offset
;
3932 spin_lock_irq(&conf
->device_lock
);
3933 wait_event_lock_irq(conf
->wait_for_stripe
,
3935 conf
->device_lock
, /* nothing */);
3936 atomic_inc(&conf
->active_aligned_reads
);
3937 spin_unlock_irq(&conf
->device_lock
);
3939 generic_make_request(align_bi
);
3948 /* __get_priority_stripe - get the next stripe to process
3950 * Full stripe writes are allowed to pass preread active stripes up until
3951 * the bypass_threshold is exceeded. In general the bypass_count
3952 * increments when the handle_list is handled before the hold_list; however, it
3953 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3954 * stripe with in flight i/o. The bypass_count will be reset when the
3955 * head of the hold_list has changed, i.e. the head was promoted to the
3958 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
3960 struct stripe_head
*sh
;
3962 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3964 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3965 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3966 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3968 if (!list_empty(&conf
->handle_list
)) {
3969 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3971 if (list_empty(&conf
->hold_list
))
3972 conf
->bypass_count
= 0;
3973 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3974 if (conf
->hold_list
.next
== conf
->last_hold
)
3975 conf
->bypass_count
++;
3977 conf
->last_hold
= conf
->hold_list
.next
;
3978 conf
->bypass_count
-= conf
->bypass_threshold
;
3979 if (conf
->bypass_count
< 0)
3980 conf
->bypass_count
= 0;
3983 } else if (!list_empty(&conf
->hold_list
) &&
3984 ((conf
->bypass_threshold
&&
3985 conf
->bypass_count
> conf
->bypass_threshold
) ||
3986 atomic_read(&conf
->pending_full_writes
) == 0)) {
3987 sh
= list_entry(conf
->hold_list
.next
,
3989 conf
->bypass_count
-= conf
->bypass_threshold
;
3990 if (conf
->bypass_count
< 0)
3991 conf
->bypass_count
= 0;
3995 list_del_init(&sh
->lru
);
3996 atomic_inc(&sh
->count
);
3997 BUG_ON(atomic_read(&sh
->count
) != 1);
4001 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4003 struct r5conf
*conf
= mddev
->private;
4005 sector_t new_sector
;
4006 sector_t logical_sector
, last_sector
;
4007 struct stripe_head
*sh
;
4008 const int rw
= bio_data_dir(bi
);
4011 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4012 md_flush_request(mddev
, bi
);
4016 md_write_start(mddev
, bi
);
4019 mddev
->reshape_position
== MaxSector
&&
4020 chunk_aligned_read(mddev
,bi
))
4023 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4024 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4026 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4028 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4034 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4035 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4036 /* spinlock is needed as reshape_progress may be
4037 * 64bit on a 32bit platform, and so it might be
4038 * possible to see a half-updated value
4039 * Of course reshape_progress could change after
4040 * the lock is dropped, so once we get a reference
4041 * to the stripe that we think it is, we will have
4044 spin_lock_irq(&conf
->device_lock
);
4045 if (mddev
->reshape_backwards
4046 ? logical_sector
< conf
->reshape_progress
4047 : logical_sector
>= conf
->reshape_progress
) {
4050 if (mddev
->reshape_backwards
4051 ? logical_sector
< conf
->reshape_safe
4052 : logical_sector
>= conf
->reshape_safe
) {
4053 spin_unlock_irq(&conf
->device_lock
);
4058 spin_unlock_irq(&conf
->device_lock
);
4061 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4064 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4065 (unsigned long long)new_sector
,
4066 (unsigned long long)logical_sector
);
4068 sh
= get_active_stripe(conf
, new_sector
, previous
,
4069 (bi
->bi_rw
&RWA_MASK
), 0);
4071 if (unlikely(previous
)) {
4072 /* expansion might have moved on while waiting for a
4073 * stripe, so we must do the range check again.
4074 * Expansion could still move past after this
4075 * test, but as we are holding a reference to
4076 * 'sh', we know that if that happens,
4077 * STRIPE_EXPANDING will get set and the expansion
4078 * won't proceed until we finish with the stripe.
4081 spin_lock_irq(&conf
->device_lock
);
4082 if (mddev
->reshape_backwards
4083 ? logical_sector
>= conf
->reshape_progress
4084 : logical_sector
< conf
->reshape_progress
)
4085 /* mismatch, need to try again */
4087 spin_unlock_irq(&conf
->device_lock
);
4096 logical_sector
>= mddev
->suspend_lo
&&
4097 logical_sector
< mddev
->suspend_hi
) {
4099 /* As the suspend_* range is controlled by
4100 * userspace, we want an interruptible
4103 flush_signals(current
);
4104 prepare_to_wait(&conf
->wait_for_overlap
,
4105 &w
, TASK_INTERRUPTIBLE
);
4106 if (logical_sector
>= mddev
->suspend_lo
&&
4107 logical_sector
< mddev
->suspend_hi
)
4112 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4113 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4114 /* Stripe is busy expanding or
4115 * add failed due to overlap. Flush everything
4118 md_wakeup_thread(mddev
->thread
);
4123 finish_wait(&conf
->wait_for_overlap
, &w
);
4124 set_bit(STRIPE_HANDLE
, &sh
->state
);
4125 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4126 if ((bi
->bi_rw
& REQ_SYNC
) &&
4127 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4128 atomic_inc(&conf
->preread_active_stripes
);
4129 mddev_check_plugged(mddev
);
4132 /* cannot get stripe for read-ahead, just give-up */
4133 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4134 finish_wait(&conf
->wait_for_overlap
, &w
);
4139 remaining
= raid5_dec_bi_active_stripes(bi
);
4140 if (remaining
== 0) {
4143 md_write_end(mddev
);
4149 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4151 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4153 /* reshaping is quite different to recovery/resync so it is
4154 * handled quite separately ... here.
4156 * On each call to sync_request, we gather one chunk worth of
4157 * destination stripes and flag them as expanding.
4158 * Then we find all the source stripes and request reads.
4159 * As the reads complete, handle_stripe will copy the data
4160 * into the destination stripe and release that stripe.
4162 struct r5conf
*conf
= mddev
->private;
4163 struct stripe_head
*sh
;
4164 sector_t first_sector
, last_sector
;
4165 int raid_disks
= conf
->previous_raid_disks
;
4166 int data_disks
= raid_disks
- conf
->max_degraded
;
4167 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4170 sector_t writepos
, readpos
, safepos
;
4171 sector_t stripe_addr
;
4172 int reshape_sectors
;
4173 struct list_head stripes
;
4175 if (sector_nr
== 0) {
4176 /* If restarting in the middle, skip the initial sectors */
4177 if (mddev
->reshape_backwards
&&
4178 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4179 sector_nr
= raid5_size(mddev
, 0, 0)
4180 - conf
->reshape_progress
;
4181 } else if (!mddev
->reshape_backwards
&&
4182 conf
->reshape_progress
> 0)
4183 sector_nr
= conf
->reshape_progress
;
4184 sector_div(sector_nr
, new_data_disks
);
4186 mddev
->curr_resync_completed
= sector_nr
;
4187 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4193 /* We need to process a full chunk at a time.
4194 * If old and new chunk sizes differ, we need to process the
4197 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4198 reshape_sectors
= mddev
->new_chunk_sectors
;
4200 reshape_sectors
= mddev
->chunk_sectors
;
4202 /* We update the metadata at least every 10 seconds, or when
4203 * the data about to be copied would over-write the source of
4204 * the data at the front of the range. i.e. one new_stripe
4205 * along from reshape_progress new_maps to after where
4206 * reshape_safe old_maps to
4208 writepos
= conf
->reshape_progress
;
4209 sector_div(writepos
, new_data_disks
);
4210 readpos
= conf
->reshape_progress
;
4211 sector_div(readpos
, data_disks
);
4212 safepos
= conf
->reshape_safe
;
4213 sector_div(safepos
, data_disks
);
4214 if (mddev
->reshape_backwards
) {
4215 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4216 readpos
+= reshape_sectors
;
4217 safepos
+= reshape_sectors
;
4219 writepos
+= reshape_sectors
;
4220 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4221 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4224 /* Having calculated the 'writepos' possibly use it
4225 * to set 'stripe_addr' which is where we will write to.
4227 if (mddev
->reshape_backwards
) {
4228 BUG_ON(conf
->reshape_progress
== 0);
4229 stripe_addr
= writepos
;
4230 BUG_ON((mddev
->dev_sectors
&
4231 ~((sector_t
)reshape_sectors
- 1))
4232 - reshape_sectors
- stripe_addr
4235 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4236 stripe_addr
= sector_nr
;
4239 /* 'writepos' is the most advanced device address we might write.
4240 * 'readpos' is the least advanced device address we might read.
4241 * 'safepos' is the least address recorded in the metadata as having
4243 * If there is a min_offset_diff, these are adjusted either by
4244 * increasing the safepos/readpos if diff is negative, or
4245 * increasing writepos if diff is positive.
4246 * If 'readpos' is then behind 'writepos', there is no way that we can
4247 * ensure safety in the face of a crash - that must be done by userspace
4248 * making a backup of the data. So in that case there is no particular
4249 * rush to update metadata.
4250 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4251 * update the metadata to advance 'safepos' to match 'readpos' so that
4252 * we can be safe in the event of a crash.
4253 * So we insist on updating metadata if safepos is behind writepos and
4254 * readpos is beyond writepos.
4255 * In any case, update the metadata every 10 seconds.
4256 * Maybe that number should be configurable, but I'm not sure it is
4257 * worth it.... maybe it could be a multiple of safemode_delay???
4259 if (conf
->min_offset_diff
< 0) {
4260 safepos
+= -conf
->min_offset_diff
;
4261 readpos
+= -conf
->min_offset_diff
;
4263 writepos
+= conf
->min_offset_diff
;
4265 if ((mddev
->reshape_backwards
4266 ? (safepos
> writepos
&& readpos
< writepos
)
4267 : (safepos
< writepos
&& readpos
> writepos
)) ||
4268 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4269 /* Cannot proceed until we've updated the superblock... */
4270 wait_event(conf
->wait_for_overlap
,
4271 atomic_read(&conf
->reshape_stripes
)==0);
4272 mddev
->reshape_position
= conf
->reshape_progress
;
4273 mddev
->curr_resync_completed
= sector_nr
;
4274 conf
->reshape_checkpoint
= jiffies
;
4275 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4276 md_wakeup_thread(mddev
->thread
);
4277 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4278 kthread_should_stop());
4279 spin_lock_irq(&conf
->device_lock
);
4280 conf
->reshape_safe
= mddev
->reshape_position
;
4281 spin_unlock_irq(&conf
->device_lock
);
4282 wake_up(&conf
->wait_for_overlap
);
4283 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4286 INIT_LIST_HEAD(&stripes
);
4287 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4289 int skipped_disk
= 0;
4290 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4291 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4292 atomic_inc(&conf
->reshape_stripes
);
4293 /* If any of this stripe is beyond the end of the old
4294 * array, then we need to zero those blocks
4296 for (j
=sh
->disks
; j
--;) {
4298 if (j
== sh
->pd_idx
)
4300 if (conf
->level
== 6 &&
4303 s
= compute_blocknr(sh
, j
, 0);
4304 if (s
< raid5_size(mddev
, 0, 0)) {
4308 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4309 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4310 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4312 if (!skipped_disk
) {
4313 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4314 set_bit(STRIPE_HANDLE
, &sh
->state
);
4316 list_add(&sh
->lru
, &stripes
);
4318 spin_lock_irq(&conf
->device_lock
);
4319 if (mddev
->reshape_backwards
)
4320 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4322 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4323 spin_unlock_irq(&conf
->device_lock
);
4324 /* Ok, those stripe are ready. We can start scheduling
4325 * reads on the source stripes.
4326 * The source stripes are determined by mapping the first and last
4327 * block on the destination stripes.
4330 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4333 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4334 * new_data_disks
- 1),
4336 if (last_sector
>= mddev
->dev_sectors
)
4337 last_sector
= mddev
->dev_sectors
- 1;
4338 while (first_sector
<= last_sector
) {
4339 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4340 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4341 set_bit(STRIPE_HANDLE
, &sh
->state
);
4343 first_sector
+= STRIPE_SECTORS
;
4345 /* Now that the sources are clearly marked, we can release
4346 * the destination stripes
4348 while (!list_empty(&stripes
)) {
4349 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4350 list_del_init(&sh
->lru
);
4353 /* If this takes us to the resync_max point where we have to pause,
4354 * then we need to write out the superblock.
4356 sector_nr
+= reshape_sectors
;
4357 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4358 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4359 /* Cannot proceed until we've updated the superblock... */
4360 wait_event(conf
->wait_for_overlap
,
4361 atomic_read(&conf
->reshape_stripes
) == 0);
4362 mddev
->reshape_position
= conf
->reshape_progress
;
4363 mddev
->curr_resync_completed
= sector_nr
;
4364 conf
->reshape_checkpoint
= jiffies
;
4365 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4366 md_wakeup_thread(mddev
->thread
);
4367 wait_event(mddev
->sb_wait
,
4368 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4369 || kthread_should_stop());
4370 spin_lock_irq(&conf
->device_lock
);
4371 conf
->reshape_safe
= mddev
->reshape_position
;
4372 spin_unlock_irq(&conf
->device_lock
);
4373 wake_up(&conf
->wait_for_overlap
);
4374 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4376 return reshape_sectors
;
4379 /* FIXME go_faster isn't used */
4380 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4382 struct r5conf
*conf
= mddev
->private;
4383 struct stripe_head
*sh
;
4384 sector_t max_sector
= mddev
->dev_sectors
;
4385 sector_t sync_blocks
;
4386 int still_degraded
= 0;
4389 if (sector_nr
>= max_sector
) {
4390 /* just being told to finish up .. nothing much to do */
4392 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4397 if (mddev
->curr_resync
< max_sector
) /* aborted */
4398 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4400 else /* completed sync */
4402 bitmap_close_sync(mddev
->bitmap
);
4407 /* Allow raid5_quiesce to complete */
4408 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4410 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4411 return reshape_request(mddev
, sector_nr
, skipped
);
4413 /* No need to check resync_max as we never do more than one
4414 * stripe, and as resync_max will always be on a chunk boundary,
4415 * if the check in md_do_sync didn't fire, there is no chance
4416 * of overstepping resync_max here
4419 /* if there is too many failed drives and we are trying
4420 * to resync, then assert that we are finished, because there is
4421 * nothing we can do.
4423 if (mddev
->degraded
>= conf
->max_degraded
&&
4424 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4425 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4429 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4430 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4431 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4432 /* we can skip this block, and probably more */
4433 sync_blocks
/= STRIPE_SECTORS
;
4435 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4438 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4440 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4442 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4443 /* make sure we don't swamp the stripe cache if someone else
4444 * is trying to get access
4446 schedule_timeout_uninterruptible(1);
4448 /* Need to check if array will still be degraded after recovery/resync
4449 * We don't need to check the 'failed' flag as when that gets set,
4452 for (i
= 0; i
< conf
->raid_disks
; i
++)
4453 if (conf
->disks
[i
].rdev
== NULL
)
4456 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4458 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4463 return STRIPE_SECTORS
;
4466 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4468 /* We may not be able to submit a whole bio at once as there
4469 * may not be enough stripe_heads available.
4470 * We cannot pre-allocate enough stripe_heads as we may need
4471 * more than exist in the cache (if we allow ever large chunks).
4472 * So we do one stripe head at a time and record in
4473 * ->bi_hw_segments how many have been done.
4475 * We *know* that this entire raid_bio is in one chunk, so
4476 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4478 struct stripe_head
*sh
;
4480 sector_t sector
, logical_sector
, last_sector
;
4485 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4486 sector
= raid5_compute_sector(conf
, logical_sector
,
4488 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4490 for (; logical_sector
< last_sector
;
4491 logical_sector
+= STRIPE_SECTORS
,
4492 sector
+= STRIPE_SECTORS
,
4495 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4496 /* already done this stripe */
4499 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4502 /* failed to get a stripe - must wait */
4503 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4504 conf
->retry_read_aligned
= raid_bio
;
4508 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4510 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4511 conf
->retry_read_aligned
= raid_bio
;
4519 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4521 bio_endio(raid_bio
, 0);
4522 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4523 wake_up(&conf
->wait_for_stripe
);
4529 * This is our raid5 kernel thread.
4531 * We scan the hash table for stripes which can be handled now.
4532 * During the scan, completed stripes are saved for us by the interrupt
4533 * handler, so that they will not have to wait for our next wakeup.
4535 static void raid5d(struct mddev
*mddev
)
4537 struct stripe_head
*sh
;
4538 struct r5conf
*conf
= mddev
->private;
4540 struct blk_plug plug
;
4542 pr_debug("+++ raid5d active\n");
4544 md_check_recovery(mddev
);
4546 blk_start_plug(&plug
);
4548 spin_lock_irq(&conf
->device_lock
);
4552 if (atomic_read(&mddev
->plug_cnt
) == 0 &&
4553 !list_empty(&conf
->bitmap_list
)) {
4554 /* Now is a good time to flush some bitmap updates */
4556 spin_unlock_irq(&conf
->device_lock
);
4557 bitmap_unplug(mddev
->bitmap
);
4558 spin_lock_irq(&conf
->device_lock
);
4559 conf
->seq_write
= conf
->seq_flush
;
4560 activate_bit_delay(conf
);
4562 if (atomic_read(&mddev
->plug_cnt
) == 0)
4563 raid5_activate_delayed(conf
);
4565 while ((bio
= remove_bio_from_retry(conf
))) {
4567 spin_unlock_irq(&conf
->device_lock
);
4568 ok
= retry_aligned_read(conf
, bio
);
4569 spin_lock_irq(&conf
->device_lock
);
4575 sh
= __get_priority_stripe(conf
);
4579 spin_unlock_irq(&conf
->device_lock
);
4586 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
4587 md_check_recovery(mddev
);
4589 spin_lock_irq(&conf
->device_lock
);
4591 pr_debug("%d stripes handled\n", handled
);
4593 spin_unlock_irq(&conf
->device_lock
);
4595 async_tx_issue_pending_all();
4596 blk_finish_plug(&plug
);
4598 pr_debug("--- raid5d inactive\n");
4602 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4604 struct r5conf
*conf
= mddev
->private;
4606 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4612 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4614 struct r5conf
*conf
= mddev
->private;
4617 if (size
<= 16 || size
> 32768)
4619 while (size
< conf
->max_nr_stripes
) {
4620 if (drop_one_stripe(conf
))
4621 conf
->max_nr_stripes
--;
4625 err
= md_allow_write(mddev
);
4628 while (size
> conf
->max_nr_stripes
) {
4629 if (grow_one_stripe(conf
))
4630 conf
->max_nr_stripes
++;
4635 EXPORT_SYMBOL(raid5_set_cache_size
);
4638 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4640 struct r5conf
*conf
= mddev
->private;
4644 if (len
>= PAGE_SIZE
)
4649 if (strict_strtoul(page
, 10, &new))
4651 err
= raid5_set_cache_size(mddev
, new);
4657 static struct md_sysfs_entry
4658 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4659 raid5_show_stripe_cache_size
,
4660 raid5_store_stripe_cache_size
);
4663 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4665 struct r5conf
*conf
= mddev
->private;
4667 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4673 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4675 struct r5conf
*conf
= mddev
->private;
4677 if (len
>= PAGE_SIZE
)
4682 if (strict_strtoul(page
, 10, &new))
4684 if (new > conf
->max_nr_stripes
)
4686 conf
->bypass_threshold
= new;
4690 static struct md_sysfs_entry
4691 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4693 raid5_show_preread_threshold
,
4694 raid5_store_preread_threshold
);
4697 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4699 struct r5conf
*conf
= mddev
->private;
4701 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4706 static struct md_sysfs_entry
4707 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4709 static struct attribute
*raid5_attrs
[] = {
4710 &raid5_stripecache_size
.attr
,
4711 &raid5_stripecache_active
.attr
,
4712 &raid5_preread_bypass_threshold
.attr
,
4715 static struct attribute_group raid5_attrs_group
= {
4717 .attrs
= raid5_attrs
,
4721 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4723 struct r5conf
*conf
= mddev
->private;
4726 sectors
= mddev
->dev_sectors
;
4728 /* size is defined by the smallest of previous and new size */
4729 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4731 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4732 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4733 return sectors
* (raid_disks
- conf
->max_degraded
);
4736 static void raid5_free_percpu(struct r5conf
*conf
)
4738 struct raid5_percpu
*percpu
;
4745 for_each_possible_cpu(cpu
) {
4746 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4747 safe_put_page(percpu
->spare_page
);
4748 kfree(percpu
->scribble
);
4750 #ifdef CONFIG_HOTPLUG_CPU
4751 unregister_cpu_notifier(&conf
->cpu_notify
);
4755 free_percpu(conf
->percpu
);
4758 static void free_conf(struct r5conf
*conf
)
4760 shrink_stripes(conf
);
4761 raid5_free_percpu(conf
);
4763 kfree(conf
->stripe_hashtbl
);
4767 #ifdef CONFIG_HOTPLUG_CPU
4768 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4771 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
4772 long cpu
= (long)hcpu
;
4773 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4776 case CPU_UP_PREPARE
:
4777 case CPU_UP_PREPARE_FROZEN
:
4778 if (conf
->level
== 6 && !percpu
->spare_page
)
4779 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4780 if (!percpu
->scribble
)
4781 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4783 if (!percpu
->scribble
||
4784 (conf
->level
== 6 && !percpu
->spare_page
)) {
4785 safe_put_page(percpu
->spare_page
);
4786 kfree(percpu
->scribble
);
4787 pr_err("%s: failed memory allocation for cpu%ld\n",
4789 return notifier_from_errno(-ENOMEM
);
4793 case CPU_DEAD_FROZEN
:
4794 safe_put_page(percpu
->spare_page
);
4795 kfree(percpu
->scribble
);
4796 percpu
->spare_page
= NULL
;
4797 percpu
->scribble
= NULL
;
4806 static int raid5_alloc_percpu(struct r5conf
*conf
)
4809 struct page
*spare_page
;
4810 struct raid5_percpu __percpu
*allcpus
;
4814 allcpus
= alloc_percpu(struct raid5_percpu
);
4817 conf
->percpu
= allcpus
;
4821 for_each_present_cpu(cpu
) {
4822 if (conf
->level
== 6) {
4823 spare_page
= alloc_page(GFP_KERNEL
);
4828 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4830 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4835 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4837 #ifdef CONFIG_HOTPLUG_CPU
4838 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4839 conf
->cpu_notify
.priority
= 0;
4841 err
= register_cpu_notifier(&conf
->cpu_notify
);
4848 static struct r5conf
*setup_conf(struct mddev
*mddev
)
4850 struct r5conf
*conf
;
4851 int raid_disk
, memory
, max_disks
;
4852 struct md_rdev
*rdev
;
4853 struct disk_info
*disk
;
4856 if (mddev
->new_level
!= 5
4857 && mddev
->new_level
!= 4
4858 && mddev
->new_level
!= 6) {
4859 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4860 mdname(mddev
), mddev
->new_level
);
4861 return ERR_PTR(-EIO
);
4863 if ((mddev
->new_level
== 5
4864 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4865 (mddev
->new_level
== 6
4866 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4867 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4868 mdname(mddev
), mddev
->new_layout
);
4869 return ERR_PTR(-EIO
);
4871 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4872 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4873 mdname(mddev
), mddev
->raid_disks
);
4874 return ERR_PTR(-EINVAL
);
4877 if (!mddev
->new_chunk_sectors
||
4878 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4879 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4880 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4881 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4882 return ERR_PTR(-EINVAL
);
4885 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
4888 spin_lock_init(&conf
->device_lock
);
4889 init_waitqueue_head(&conf
->wait_for_stripe
);
4890 init_waitqueue_head(&conf
->wait_for_overlap
);
4891 INIT_LIST_HEAD(&conf
->handle_list
);
4892 INIT_LIST_HEAD(&conf
->hold_list
);
4893 INIT_LIST_HEAD(&conf
->delayed_list
);
4894 INIT_LIST_HEAD(&conf
->bitmap_list
);
4895 INIT_LIST_HEAD(&conf
->inactive_list
);
4896 atomic_set(&conf
->active_stripes
, 0);
4897 atomic_set(&conf
->preread_active_stripes
, 0);
4898 atomic_set(&conf
->active_aligned_reads
, 0);
4899 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4900 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
4902 conf
->raid_disks
= mddev
->raid_disks
;
4903 if (mddev
->reshape_position
== MaxSector
)
4904 conf
->previous_raid_disks
= mddev
->raid_disks
;
4906 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4907 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4908 conf
->scribble_len
= scribble_len(max_disks
);
4910 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4915 conf
->mddev
= mddev
;
4917 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4920 conf
->level
= mddev
->new_level
;
4921 if (raid5_alloc_percpu(conf
) != 0)
4924 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4926 rdev_for_each(rdev
, mddev
) {
4927 raid_disk
= rdev
->raid_disk
;
4928 if (raid_disk
>= max_disks
4931 disk
= conf
->disks
+ raid_disk
;
4933 if (test_bit(Replacement
, &rdev
->flags
)) {
4934 if (disk
->replacement
)
4936 disk
->replacement
= rdev
;
4943 if (test_bit(In_sync
, &rdev
->flags
)) {
4944 char b
[BDEVNAME_SIZE
];
4945 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4947 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4948 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4949 /* Cannot rely on bitmap to complete recovery */
4953 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4954 conf
->level
= mddev
->new_level
;
4955 if (conf
->level
== 6)
4956 conf
->max_degraded
= 2;
4958 conf
->max_degraded
= 1;
4959 conf
->algorithm
= mddev
->new_layout
;
4960 conf
->max_nr_stripes
= NR_STRIPES
;
4961 conf
->reshape_progress
= mddev
->reshape_position
;
4962 if (conf
->reshape_progress
!= MaxSector
) {
4963 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4964 conf
->prev_algo
= mddev
->layout
;
4967 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4968 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4969 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4971 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4972 mdname(mddev
), memory
);
4975 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4976 mdname(mddev
), memory
);
4978 sprintf(pers_name
, "raid%d", mddev
->new_level
);
4979 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
4980 if (!conf
->thread
) {
4982 "md/raid:%s: couldn't allocate thread.\n",
4992 return ERR_PTR(-EIO
);
4994 return ERR_PTR(-ENOMEM
);
4998 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5001 case ALGORITHM_PARITY_0
:
5002 if (raid_disk
< max_degraded
)
5005 case ALGORITHM_PARITY_N
:
5006 if (raid_disk
>= raid_disks
- max_degraded
)
5009 case ALGORITHM_PARITY_0_6
:
5010 if (raid_disk
== 0 ||
5011 raid_disk
== raid_disks
- 1)
5014 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5015 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5016 case ALGORITHM_LEFT_SYMMETRIC_6
:
5017 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5018 if (raid_disk
== raid_disks
- 1)
5024 static int run(struct mddev
*mddev
)
5026 struct r5conf
*conf
;
5027 int working_disks
= 0;
5028 int dirty_parity_disks
= 0;
5029 struct md_rdev
*rdev
;
5030 sector_t reshape_offset
= 0;
5032 long long min_offset_diff
= 0;
5035 if (mddev
->recovery_cp
!= MaxSector
)
5036 printk(KERN_NOTICE
"md/raid:%s: not clean"
5037 " -- starting background reconstruction\n",
5040 rdev_for_each(rdev
, mddev
) {
5042 if (rdev
->raid_disk
< 0)
5044 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5046 min_offset_diff
= diff
;
5048 } else if (mddev
->reshape_backwards
&&
5049 diff
< min_offset_diff
)
5050 min_offset_diff
= diff
;
5051 else if (!mddev
->reshape_backwards
&&
5052 diff
> min_offset_diff
)
5053 min_offset_diff
= diff
;
5056 if (mddev
->reshape_position
!= MaxSector
) {
5057 /* Check that we can continue the reshape.
5058 * Difficulties arise if the stripe we would write to
5059 * next is at or after the stripe we would read from next.
5060 * For a reshape that changes the number of devices, this
5061 * is only possible for a very short time, and mdadm makes
5062 * sure that time appears to have past before assembling
5063 * the array. So we fail if that time hasn't passed.
5064 * For a reshape that keeps the number of devices the same
5065 * mdadm must be monitoring the reshape can keeping the
5066 * critical areas read-only and backed up. It will start
5067 * the array in read-only mode, so we check for that.
5069 sector_t here_new
, here_old
;
5071 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5073 if (mddev
->new_level
!= mddev
->level
) {
5074 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5075 "required - aborting.\n",
5079 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5080 /* reshape_position must be on a new-stripe boundary, and one
5081 * further up in new geometry must map after here in old
5084 here_new
= mddev
->reshape_position
;
5085 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5086 (mddev
->raid_disks
- max_degraded
))) {
5087 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5088 "on a stripe boundary\n", mdname(mddev
));
5091 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5092 /* here_new is the stripe we will write to */
5093 here_old
= mddev
->reshape_position
;
5094 sector_div(here_old
, mddev
->chunk_sectors
*
5095 (old_disks
-max_degraded
));
5096 /* here_old is the first stripe that we might need to read
5098 if (mddev
->delta_disks
== 0) {
5099 if ((here_new
* mddev
->new_chunk_sectors
!=
5100 here_old
* mddev
->chunk_sectors
)) {
5101 printk(KERN_ERR
"md/raid:%s: reshape position is"
5102 " confused - aborting\n", mdname(mddev
));
5105 /* We cannot be sure it is safe to start an in-place
5106 * reshape. It is only safe if user-space is monitoring
5107 * and taking constant backups.
5108 * mdadm always starts a situation like this in
5109 * readonly mode so it can take control before
5110 * allowing any writes. So just check for that.
5112 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5113 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5114 /* not really in-place - so OK */;
5115 else if (mddev
->ro
== 0) {
5116 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5117 "must be started in read-only mode "
5122 } else if (mddev
->reshape_backwards
5123 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5124 here_old
* mddev
->chunk_sectors
)
5125 : (here_new
* mddev
->new_chunk_sectors
>=
5126 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5127 /* Reading from the same stripe as writing to - bad */
5128 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5129 "auto-recovery - aborting.\n",
5133 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5135 /* OK, we should be able to continue; */
5137 BUG_ON(mddev
->level
!= mddev
->new_level
);
5138 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5139 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5140 BUG_ON(mddev
->delta_disks
!= 0);
5143 if (mddev
->private == NULL
)
5144 conf
= setup_conf(mddev
);
5146 conf
= mddev
->private;
5149 return PTR_ERR(conf
);
5151 conf
->min_offset_diff
= min_offset_diff
;
5152 mddev
->thread
= conf
->thread
;
5153 conf
->thread
= NULL
;
5154 mddev
->private = conf
;
5156 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5158 rdev
= conf
->disks
[i
].rdev
;
5159 if (!rdev
&& conf
->disks
[i
].replacement
) {
5160 /* The replacement is all we have yet */
5161 rdev
= conf
->disks
[i
].replacement
;
5162 conf
->disks
[i
].replacement
= NULL
;
5163 clear_bit(Replacement
, &rdev
->flags
);
5164 conf
->disks
[i
].rdev
= rdev
;
5168 if (conf
->disks
[i
].replacement
&&
5169 conf
->reshape_progress
!= MaxSector
) {
5170 /* replacements and reshape simply do not mix. */
5171 printk(KERN_ERR
"md: cannot handle concurrent "
5172 "replacement and reshape.\n");
5175 if (test_bit(In_sync
, &rdev
->flags
)) {
5179 /* This disc is not fully in-sync. However if it
5180 * just stored parity (beyond the recovery_offset),
5181 * when we don't need to be concerned about the
5182 * array being dirty.
5183 * When reshape goes 'backwards', we never have
5184 * partially completed devices, so we only need
5185 * to worry about reshape going forwards.
5187 /* Hack because v0.91 doesn't store recovery_offset properly. */
5188 if (mddev
->major_version
== 0 &&
5189 mddev
->minor_version
> 90)
5190 rdev
->recovery_offset
= reshape_offset
;
5192 if (rdev
->recovery_offset
< reshape_offset
) {
5193 /* We need to check old and new layout */
5194 if (!only_parity(rdev
->raid_disk
,
5197 conf
->max_degraded
))
5200 if (!only_parity(rdev
->raid_disk
,
5202 conf
->previous_raid_disks
,
5203 conf
->max_degraded
))
5205 dirty_parity_disks
++;
5209 * 0 for a fully functional array, 1 or 2 for a degraded array.
5211 mddev
->degraded
= calc_degraded(conf
);
5213 if (has_failed(conf
)) {
5214 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5215 " (%d/%d failed)\n",
5216 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5220 /* device size must be a multiple of chunk size */
5221 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5222 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5224 if (mddev
->degraded
> dirty_parity_disks
&&
5225 mddev
->recovery_cp
!= MaxSector
) {
5226 if (mddev
->ok_start_degraded
)
5228 "md/raid:%s: starting dirty degraded array"
5229 " - data corruption possible.\n",
5233 "md/raid:%s: cannot start dirty degraded array.\n",
5239 if (mddev
->degraded
== 0)
5240 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5241 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5242 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5245 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5246 " out of %d devices, algorithm %d\n",
5247 mdname(mddev
), conf
->level
,
5248 mddev
->raid_disks
- mddev
->degraded
,
5249 mddev
->raid_disks
, mddev
->new_layout
);
5251 print_raid5_conf(conf
);
5253 if (conf
->reshape_progress
!= MaxSector
) {
5254 conf
->reshape_safe
= conf
->reshape_progress
;
5255 atomic_set(&conf
->reshape_stripes
, 0);
5256 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5257 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5258 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5259 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5260 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5265 /* Ok, everything is just fine now */
5266 if (mddev
->to_remove
== &raid5_attrs_group
)
5267 mddev
->to_remove
= NULL
;
5268 else if (mddev
->kobj
.sd
&&
5269 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5271 "raid5: failed to create sysfs attributes for %s\n",
5273 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5277 /* read-ahead size must cover two whole stripes, which
5278 * is 2 * (datadisks) * chunksize where 'n' is the
5279 * number of raid devices
5281 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5282 int stripe
= data_disks
*
5283 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5284 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5285 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5287 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5289 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5290 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5292 chunk_size
= mddev
->chunk_sectors
<< 9;
5293 blk_queue_io_min(mddev
->queue
, chunk_size
);
5294 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5295 (conf
->raid_disks
- conf
->max_degraded
));
5297 rdev_for_each(rdev
, mddev
) {
5298 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5299 rdev
->data_offset
<< 9);
5300 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5301 rdev
->new_data_offset
<< 9);
5307 md_unregister_thread(&mddev
->thread
);
5308 print_raid5_conf(conf
);
5310 mddev
->private = NULL
;
5311 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5315 static int stop(struct mddev
*mddev
)
5317 struct r5conf
*conf
= mddev
->private;
5319 md_unregister_thread(&mddev
->thread
);
5321 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5323 mddev
->private = NULL
;
5324 mddev
->to_remove
= &raid5_attrs_group
;
5328 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5330 struct r5conf
*conf
= mddev
->private;
5333 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5334 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5335 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5336 for (i
= 0; i
< conf
->raid_disks
; i
++)
5337 seq_printf (seq
, "%s",
5338 conf
->disks
[i
].rdev
&&
5339 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5340 seq_printf (seq
, "]");
5343 static void print_raid5_conf (struct r5conf
*conf
)
5346 struct disk_info
*tmp
;
5348 printk(KERN_DEBUG
"RAID conf printout:\n");
5350 printk("(conf==NULL)\n");
5353 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5355 conf
->raid_disks
- conf
->mddev
->degraded
);
5357 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5358 char b
[BDEVNAME_SIZE
];
5359 tmp
= conf
->disks
+ i
;
5361 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5362 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5363 bdevname(tmp
->rdev
->bdev
, b
));
5367 static int raid5_spare_active(struct mddev
*mddev
)
5370 struct r5conf
*conf
= mddev
->private;
5371 struct disk_info
*tmp
;
5373 unsigned long flags
;
5375 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5376 tmp
= conf
->disks
+ i
;
5377 if (tmp
->replacement
5378 && tmp
->replacement
->recovery_offset
== MaxSector
5379 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5380 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5381 /* Replacement has just become active. */
5383 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5386 /* Replaced device not technically faulty,
5387 * but we need to be sure it gets removed
5388 * and never re-added.
5390 set_bit(Faulty
, &tmp
->rdev
->flags
);
5391 sysfs_notify_dirent_safe(
5392 tmp
->rdev
->sysfs_state
);
5394 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5395 } else if (tmp
->rdev
5396 && tmp
->rdev
->recovery_offset
== MaxSector
5397 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5398 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5400 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5403 spin_lock_irqsave(&conf
->device_lock
, flags
);
5404 mddev
->degraded
= calc_degraded(conf
);
5405 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5406 print_raid5_conf(conf
);
5410 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5412 struct r5conf
*conf
= mddev
->private;
5414 int number
= rdev
->raid_disk
;
5415 struct md_rdev
**rdevp
;
5416 struct disk_info
*p
= conf
->disks
+ number
;
5418 print_raid5_conf(conf
);
5419 if (rdev
== p
->rdev
)
5421 else if (rdev
== p
->replacement
)
5422 rdevp
= &p
->replacement
;
5426 if (number
>= conf
->raid_disks
&&
5427 conf
->reshape_progress
== MaxSector
)
5428 clear_bit(In_sync
, &rdev
->flags
);
5430 if (test_bit(In_sync
, &rdev
->flags
) ||
5431 atomic_read(&rdev
->nr_pending
)) {
5435 /* Only remove non-faulty devices if recovery
5438 if (!test_bit(Faulty
, &rdev
->flags
) &&
5439 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5440 !has_failed(conf
) &&
5441 (!p
->replacement
|| p
->replacement
== rdev
) &&
5442 number
< conf
->raid_disks
) {
5448 if (atomic_read(&rdev
->nr_pending
)) {
5449 /* lost the race, try later */
5452 } else if (p
->replacement
) {
5453 /* We must have just cleared 'rdev' */
5454 p
->rdev
= p
->replacement
;
5455 clear_bit(Replacement
, &p
->replacement
->flags
);
5456 smp_mb(); /* Make sure other CPUs may see both as identical
5457 * but will never see neither - if they are careful
5459 p
->replacement
= NULL
;
5460 clear_bit(WantReplacement
, &rdev
->flags
);
5462 /* We might have just removed the Replacement as faulty-
5463 * clear the bit just in case
5465 clear_bit(WantReplacement
, &rdev
->flags
);
5468 print_raid5_conf(conf
);
5472 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5474 struct r5conf
*conf
= mddev
->private;
5477 struct disk_info
*p
;
5479 int last
= conf
->raid_disks
- 1;
5481 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5484 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5485 /* no point adding a device */
5488 if (rdev
->raid_disk
>= 0)
5489 first
= last
= rdev
->raid_disk
;
5492 * find the disk ... but prefer rdev->saved_raid_disk
5495 if (rdev
->saved_raid_disk
>= 0 &&
5496 rdev
->saved_raid_disk
>= first
&&
5497 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5498 first
= rdev
->saved_raid_disk
;
5500 for (disk
= first
; disk
<= last
; disk
++) {
5501 p
= conf
->disks
+ disk
;
5502 if (p
->rdev
== NULL
) {
5503 clear_bit(In_sync
, &rdev
->flags
);
5504 rdev
->raid_disk
= disk
;
5506 if (rdev
->saved_raid_disk
!= disk
)
5508 rcu_assign_pointer(p
->rdev
, rdev
);
5512 for (disk
= first
; disk
<= last
; disk
++) {
5513 p
= conf
->disks
+ disk
;
5514 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5515 p
->replacement
== NULL
) {
5516 clear_bit(In_sync
, &rdev
->flags
);
5517 set_bit(Replacement
, &rdev
->flags
);
5518 rdev
->raid_disk
= disk
;
5521 rcu_assign_pointer(p
->replacement
, rdev
);
5526 print_raid5_conf(conf
);
5530 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5532 /* no resync is happening, and there is enough space
5533 * on all devices, so we can resize.
5534 * We need to make sure resync covers any new space.
5535 * If the array is shrinking we should possibly wait until
5536 * any io in the removed space completes, but it hardly seems
5540 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5541 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5542 if (mddev
->external_size
&&
5543 mddev
->array_sectors
> newsize
)
5545 if (mddev
->bitmap
) {
5546 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5550 md_set_array_sectors(mddev
, newsize
);
5551 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5552 revalidate_disk(mddev
->gendisk
);
5553 if (sectors
> mddev
->dev_sectors
&&
5554 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5555 mddev
->recovery_cp
= mddev
->dev_sectors
;
5556 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5558 mddev
->dev_sectors
= sectors
;
5559 mddev
->resync_max_sectors
= sectors
;
5563 static int check_stripe_cache(struct mddev
*mddev
)
5565 /* Can only proceed if there are plenty of stripe_heads.
5566 * We need a minimum of one full stripe,, and for sensible progress
5567 * it is best to have about 4 times that.
5568 * If we require 4 times, then the default 256 4K stripe_heads will
5569 * allow for chunk sizes up to 256K, which is probably OK.
5570 * If the chunk size is greater, user-space should request more
5571 * stripe_heads first.
5573 struct r5conf
*conf
= mddev
->private;
5574 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5575 > conf
->max_nr_stripes
||
5576 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5577 > conf
->max_nr_stripes
) {
5578 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5580 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5587 static int check_reshape(struct mddev
*mddev
)
5589 struct r5conf
*conf
= mddev
->private;
5591 if (mddev
->delta_disks
== 0 &&
5592 mddev
->new_layout
== mddev
->layout
&&
5593 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5594 return 0; /* nothing to do */
5595 if (has_failed(conf
))
5597 if (mddev
->delta_disks
< 0) {
5598 /* We might be able to shrink, but the devices must
5599 * be made bigger first.
5600 * For raid6, 4 is the minimum size.
5601 * Otherwise 2 is the minimum
5604 if (mddev
->level
== 6)
5606 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5610 if (!check_stripe_cache(mddev
))
5613 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5616 static int raid5_start_reshape(struct mddev
*mddev
)
5618 struct r5conf
*conf
= mddev
->private;
5619 struct md_rdev
*rdev
;
5621 unsigned long flags
;
5623 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5626 if (!check_stripe_cache(mddev
))
5629 if (has_failed(conf
))
5632 rdev_for_each(rdev
, mddev
) {
5633 if (!test_bit(In_sync
, &rdev
->flags
)
5634 && !test_bit(Faulty
, &rdev
->flags
))
5638 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5639 /* Not enough devices even to make a degraded array
5644 /* Refuse to reduce size of the array. Any reductions in
5645 * array size must be through explicit setting of array_size
5648 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5649 < mddev
->array_sectors
) {
5650 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5651 "before number of disks\n", mdname(mddev
));
5655 atomic_set(&conf
->reshape_stripes
, 0);
5656 spin_lock_irq(&conf
->device_lock
);
5657 conf
->previous_raid_disks
= conf
->raid_disks
;
5658 conf
->raid_disks
+= mddev
->delta_disks
;
5659 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5660 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5661 conf
->prev_algo
= conf
->algorithm
;
5662 conf
->algorithm
= mddev
->new_layout
;
5664 /* Code that selects data_offset needs to see the generation update
5665 * if reshape_progress has been set - so a memory barrier needed.
5668 if (mddev
->reshape_backwards
)
5669 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5671 conf
->reshape_progress
= 0;
5672 conf
->reshape_safe
= conf
->reshape_progress
;
5673 spin_unlock_irq(&conf
->device_lock
);
5675 /* Add some new drives, as many as will fit.
5676 * We know there are enough to make the newly sized array work.
5677 * Don't add devices if we are reducing the number of
5678 * devices in the array. This is because it is not possible
5679 * to correctly record the "partially reconstructed" state of
5680 * such devices during the reshape and confusion could result.
5682 if (mddev
->delta_disks
>= 0) {
5683 rdev_for_each(rdev
, mddev
)
5684 if (rdev
->raid_disk
< 0 &&
5685 !test_bit(Faulty
, &rdev
->flags
)) {
5686 if (raid5_add_disk(mddev
, rdev
) == 0) {
5688 >= conf
->previous_raid_disks
)
5689 set_bit(In_sync
, &rdev
->flags
);
5691 rdev
->recovery_offset
= 0;
5693 if (sysfs_link_rdev(mddev
, rdev
))
5694 /* Failure here is OK */;
5696 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5697 && !test_bit(Faulty
, &rdev
->flags
)) {
5698 /* This is a spare that was manually added */
5699 set_bit(In_sync
, &rdev
->flags
);
5702 /* When a reshape changes the number of devices,
5703 * ->degraded is measured against the larger of the
5704 * pre and post number of devices.
5706 spin_lock_irqsave(&conf
->device_lock
, flags
);
5707 mddev
->degraded
= calc_degraded(conf
);
5708 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5710 mddev
->raid_disks
= conf
->raid_disks
;
5711 mddev
->reshape_position
= conf
->reshape_progress
;
5712 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5714 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5715 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5716 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5717 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5718 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5720 if (!mddev
->sync_thread
) {
5721 mddev
->recovery
= 0;
5722 spin_lock_irq(&conf
->device_lock
);
5723 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5724 rdev_for_each(rdev
, mddev
)
5725 rdev
->new_data_offset
= rdev
->data_offset
;
5727 conf
->reshape_progress
= MaxSector
;
5728 mddev
->reshape_position
= MaxSector
;
5729 spin_unlock_irq(&conf
->device_lock
);
5732 conf
->reshape_checkpoint
= jiffies
;
5733 md_wakeup_thread(mddev
->sync_thread
);
5734 md_new_event(mddev
);
5738 /* This is called from the reshape thread and should make any
5739 * changes needed in 'conf'
5741 static void end_reshape(struct r5conf
*conf
)
5744 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5745 struct md_rdev
*rdev
;
5747 spin_lock_irq(&conf
->device_lock
);
5748 conf
->previous_raid_disks
= conf
->raid_disks
;
5749 rdev_for_each(rdev
, conf
->mddev
)
5750 rdev
->data_offset
= rdev
->new_data_offset
;
5752 conf
->reshape_progress
= MaxSector
;
5753 spin_unlock_irq(&conf
->device_lock
);
5754 wake_up(&conf
->wait_for_overlap
);
5756 /* read-ahead size must cover two whole stripes, which is
5757 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5759 if (conf
->mddev
->queue
) {
5760 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5761 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5763 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5764 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5769 /* This is called from the raid5d thread with mddev_lock held.
5770 * It makes config changes to the device.
5772 static void raid5_finish_reshape(struct mddev
*mddev
)
5774 struct r5conf
*conf
= mddev
->private;
5776 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5778 if (mddev
->delta_disks
> 0) {
5779 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5780 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5781 revalidate_disk(mddev
->gendisk
);
5784 spin_lock_irq(&conf
->device_lock
);
5785 mddev
->degraded
= calc_degraded(conf
);
5786 spin_unlock_irq(&conf
->device_lock
);
5787 for (d
= conf
->raid_disks
;
5788 d
< conf
->raid_disks
- mddev
->delta_disks
;
5790 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
5792 clear_bit(In_sync
, &rdev
->flags
);
5793 rdev
= conf
->disks
[d
].replacement
;
5795 clear_bit(In_sync
, &rdev
->flags
);
5798 mddev
->layout
= conf
->algorithm
;
5799 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5800 mddev
->reshape_position
= MaxSector
;
5801 mddev
->delta_disks
= 0;
5802 mddev
->reshape_backwards
= 0;
5806 static void raid5_quiesce(struct mddev
*mddev
, int state
)
5808 struct r5conf
*conf
= mddev
->private;
5811 case 2: /* resume for a suspend */
5812 wake_up(&conf
->wait_for_overlap
);
5815 case 1: /* stop all writes */
5816 spin_lock_irq(&conf
->device_lock
);
5817 /* '2' tells resync/reshape to pause so that all
5818 * active stripes can drain
5821 wait_event_lock_irq(conf
->wait_for_stripe
,
5822 atomic_read(&conf
->active_stripes
) == 0 &&
5823 atomic_read(&conf
->active_aligned_reads
) == 0,
5824 conf
->device_lock
, /* nothing */);
5826 spin_unlock_irq(&conf
->device_lock
);
5827 /* allow reshape to continue */
5828 wake_up(&conf
->wait_for_overlap
);
5831 case 0: /* re-enable writes */
5832 spin_lock_irq(&conf
->device_lock
);
5834 wake_up(&conf
->wait_for_stripe
);
5835 wake_up(&conf
->wait_for_overlap
);
5836 spin_unlock_irq(&conf
->device_lock
);
5842 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
5844 struct r0conf
*raid0_conf
= mddev
->private;
5847 /* for raid0 takeover only one zone is supported */
5848 if (raid0_conf
->nr_strip_zones
> 1) {
5849 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5851 return ERR_PTR(-EINVAL
);
5854 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
5855 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
5856 mddev
->dev_sectors
= sectors
;
5857 mddev
->new_level
= level
;
5858 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5859 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5860 mddev
->raid_disks
+= 1;
5861 mddev
->delta_disks
= 1;
5862 /* make sure it will be not marked as dirty */
5863 mddev
->recovery_cp
= MaxSector
;
5865 return setup_conf(mddev
);
5869 static void *raid5_takeover_raid1(struct mddev
*mddev
)
5873 if (mddev
->raid_disks
!= 2 ||
5874 mddev
->degraded
> 1)
5875 return ERR_PTR(-EINVAL
);
5877 /* Should check if there are write-behind devices? */
5879 chunksect
= 64*2; /* 64K by default */
5881 /* The array must be an exact multiple of chunksize */
5882 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5885 if ((chunksect
<<9) < STRIPE_SIZE
)
5886 /* array size does not allow a suitable chunk size */
5887 return ERR_PTR(-EINVAL
);
5889 mddev
->new_level
= 5;
5890 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5891 mddev
->new_chunk_sectors
= chunksect
;
5893 return setup_conf(mddev
);
5896 static void *raid5_takeover_raid6(struct mddev
*mddev
)
5900 switch (mddev
->layout
) {
5901 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5902 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5904 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5905 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5907 case ALGORITHM_LEFT_SYMMETRIC_6
:
5908 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5910 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5911 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5913 case ALGORITHM_PARITY_0_6
:
5914 new_layout
= ALGORITHM_PARITY_0
;
5916 case ALGORITHM_PARITY_N
:
5917 new_layout
= ALGORITHM_PARITY_N
;
5920 return ERR_PTR(-EINVAL
);
5922 mddev
->new_level
= 5;
5923 mddev
->new_layout
= new_layout
;
5924 mddev
->delta_disks
= -1;
5925 mddev
->raid_disks
-= 1;
5926 return setup_conf(mddev
);
5930 static int raid5_check_reshape(struct mddev
*mddev
)
5932 /* For a 2-drive array, the layout and chunk size can be changed
5933 * immediately as not restriping is needed.
5934 * For larger arrays we record the new value - after validation
5935 * to be used by a reshape pass.
5937 struct r5conf
*conf
= mddev
->private;
5938 int new_chunk
= mddev
->new_chunk_sectors
;
5940 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5942 if (new_chunk
> 0) {
5943 if (!is_power_of_2(new_chunk
))
5945 if (new_chunk
< (PAGE_SIZE
>>9))
5947 if (mddev
->array_sectors
& (new_chunk
-1))
5948 /* not factor of array size */
5952 /* They look valid */
5954 if (mddev
->raid_disks
== 2) {
5955 /* can make the change immediately */
5956 if (mddev
->new_layout
>= 0) {
5957 conf
->algorithm
= mddev
->new_layout
;
5958 mddev
->layout
= mddev
->new_layout
;
5960 if (new_chunk
> 0) {
5961 conf
->chunk_sectors
= new_chunk
;
5962 mddev
->chunk_sectors
= new_chunk
;
5964 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5965 md_wakeup_thread(mddev
->thread
);
5967 return check_reshape(mddev
);
5970 static int raid6_check_reshape(struct mddev
*mddev
)
5972 int new_chunk
= mddev
->new_chunk_sectors
;
5974 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5976 if (new_chunk
> 0) {
5977 if (!is_power_of_2(new_chunk
))
5979 if (new_chunk
< (PAGE_SIZE
>> 9))
5981 if (mddev
->array_sectors
& (new_chunk
-1))
5982 /* not factor of array size */
5986 /* They look valid */
5987 return check_reshape(mddev
);
5990 static void *raid5_takeover(struct mddev
*mddev
)
5992 /* raid5 can take over:
5993 * raid0 - if there is only one strip zone - make it a raid4 layout
5994 * raid1 - if there are two drives. We need to know the chunk size
5995 * raid4 - trivial - just use a raid4 layout.
5996 * raid6 - Providing it is a *_6 layout
5998 if (mddev
->level
== 0)
5999 return raid45_takeover_raid0(mddev
, 5);
6000 if (mddev
->level
== 1)
6001 return raid5_takeover_raid1(mddev
);
6002 if (mddev
->level
== 4) {
6003 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6004 mddev
->new_level
= 5;
6005 return setup_conf(mddev
);
6007 if (mddev
->level
== 6)
6008 return raid5_takeover_raid6(mddev
);
6010 return ERR_PTR(-EINVAL
);
6013 static void *raid4_takeover(struct mddev
*mddev
)
6015 /* raid4 can take over:
6016 * raid0 - if there is only one strip zone
6017 * raid5 - if layout is right
6019 if (mddev
->level
== 0)
6020 return raid45_takeover_raid0(mddev
, 4);
6021 if (mddev
->level
== 5 &&
6022 mddev
->layout
== ALGORITHM_PARITY_N
) {
6023 mddev
->new_layout
= 0;
6024 mddev
->new_level
= 4;
6025 return setup_conf(mddev
);
6027 return ERR_PTR(-EINVAL
);
6030 static struct md_personality raid5_personality
;
6032 static void *raid6_takeover(struct mddev
*mddev
)
6034 /* Currently can only take over a raid5. We map the
6035 * personality to an equivalent raid6 personality
6036 * with the Q block at the end.
6040 if (mddev
->pers
!= &raid5_personality
)
6041 return ERR_PTR(-EINVAL
);
6042 if (mddev
->degraded
> 1)
6043 return ERR_PTR(-EINVAL
);
6044 if (mddev
->raid_disks
> 253)
6045 return ERR_PTR(-EINVAL
);
6046 if (mddev
->raid_disks
< 3)
6047 return ERR_PTR(-EINVAL
);
6049 switch (mddev
->layout
) {
6050 case ALGORITHM_LEFT_ASYMMETRIC
:
6051 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6053 case ALGORITHM_RIGHT_ASYMMETRIC
:
6054 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6056 case ALGORITHM_LEFT_SYMMETRIC
:
6057 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6059 case ALGORITHM_RIGHT_SYMMETRIC
:
6060 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6062 case ALGORITHM_PARITY_0
:
6063 new_layout
= ALGORITHM_PARITY_0_6
;
6065 case ALGORITHM_PARITY_N
:
6066 new_layout
= ALGORITHM_PARITY_N
;
6069 return ERR_PTR(-EINVAL
);
6071 mddev
->new_level
= 6;
6072 mddev
->new_layout
= new_layout
;
6073 mddev
->delta_disks
= 1;
6074 mddev
->raid_disks
+= 1;
6075 return setup_conf(mddev
);
6079 static struct md_personality raid6_personality
=
6083 .owner
= THIS_MODULE
,
6084 .make_request
= make_request
,
6088 .error_handler
= error
,
6089 .hot_add_disk
= raid5_add_disk
,
6090 .hot_remove_disk
= raid5_remove_disk
,
6091 .spare_active
= raid5_spare_active
,
6092 .sync_request
= sync_request
,
6093 .resize
= raid5_resize
,
6095 .check_reshape
= raid6_check_reshape
,
6096 .start_reshape
= raid5_start_reshape
,
6097 .finish_reshape
= raid5_finish_reshape
,
6098 .quiesce
= raid5_quiesce
,
6099 .takeover
= raid6_takeover
,
6101 static struct md_personality raid5_personality
=
6105 .owner
= THIS_MODULE
,
6106 .make_request
= make_request
,
6110 .error_handler
= error
,
6111 .hot_add_disk
= raid5_add_disk
,
6112 .hot_remove_disk
= raid5_remove_disk
,
6113 .spare_active
= raid5_spare_active
,
6114 .sync_request
= sync_request
,
6115 .resize
= raid5_resize
,
6117 .check_reshape
= raid5_check_reshape
,
6118 .start_reshape
= raid5_start_reshape
,
6119 .finish_reshape
= raid5_finish_reshape
,
6120 .quiesce
= raid5_quiesce
,
6121 .takeover
= raid5_takeover
,
6124 static struct md_personality raid4_personality
=
6128 .owner
= THIS_MODULE
,
6129 .make_request
= make_request
,
6133 .error_handler
= error
,
6134 .hot_add_disk
= raid5_add_disk
,
6135 .hot_remove_disk
= raid5_remove_disk
,
6136 .spare_active
= raid5_spare_active
,
6137 .sync_request
= sync_request
,
6138 .resize
= raid5_resize
,
6140 .check_reshape
= raid5_check_reshape
,
6141 .start_reshape
= raid5_start_reshape
,
6142 .finish_reshape
= raid5_finish_reshape
,
6143 .quiesce
= raid5_quiesce
,
6144 .takeover
= raid4_takeover
,
6147 static int __init
raid5_init(void)
6149 register_md_personality(&raid6_personality
);
6150 register_md_personality(&raid5_personality
);
6151 register_md_personality(&raid4_personality
);
6155 static void raid5_exit(void)
6157 unregister_md_personality(&raid6_personality
);
6158 unregister_md_personality(&raid5_personality
);
6159 unregister_md_personality(&raid4_personality
);
6162 module_init(raid5_init
);
6163 module_exit(raid5_exit
);
6164 MODULE_LICENSE("GPL");
6165 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6166 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6167 MODULE_ALIAS("md-raid5");
6168 MODULE_ALIAS("md-raid4");
6169 MODULE_ALIAS("md-level-5");
6170 MODULE_ALIAS("md-level-4");
6171 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6172 MODULE_ALIAS("md-raid6");
6173 MODULE_ALIAS("md-level-6");
6175 /* This used to be two separate modules, they were: */
6176 MODULE_ALIAS("raid5");
6177 MODULE_ALIAS("raid6");