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 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
657 bi
->bi_rw
|= REQ_FLUSH
;
659 bi
->bi_flags
= 1 << BIO_UPTODATE
;
661 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
662 bi
->bi_io_vec
[0].bv_offset
= 0;
663 bi
->bi_size
= STRIPE_SIZE
;
666 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
667 generic_make_request(bi
);
670 if (s
->syncing
|| s
->expanding
|| s
->expanded
672 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
674 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
676 rbi
->bi_bdev
= rrdev
->bdev
;
677 pr_debug("%s: for %llu schedule op %ld on "
678 "replacement disc %d\n",
679 __func__
, (unsigned long long)sh
->sector
,
681 atomic_inc(&sh
->count
);
682 if (use_new_offset(conf
, sh
))
683 rbi
->bi_sector
= (sh
->sector
684 + rrdev
->new_data_offset
);
686 rbi
->bi_sector
= (sh
->sector
687 + rrdev
->data_offset
);
688 rbi
->bi_flags
= 1 << BIO_UPTODATE
;
690 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
691 rbi
->bi_io_vec
[0].bv_offset
= 0;
692 rbi
->bi_size
= STRIPE_SIZE
;
694 generic_make_request(rbi
);
696 if (!rdev
&& !rrdev
) {
698 set_bit(STRIPE_DEGRADED
, &sh
->state
);
699 pr_debug("skip op %ld on disc %d for sector %llu\n",
700 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
701 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
702 set_bit(STRIPE_HANDLE
, &sh
->state
);
707 static struct dma_async_tx_descriptor
*
708 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
709 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
712 struct page
*bio_page
;
715 struct async_submit_ctl submit
;
716 enum async_tx_flags flags
= 0;
718 if (bio
->bi_sector
>= sector
)
719 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
721 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
724 flags
|= ASYNC_TX_FENCE
;
725 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
727 bio_for_each_segment(bvl
, bio
, i
) {
728 int len
= bvl
->bv_len
;
732 if (page_offset
< 0) {
733 b_offset
= -page_offset
;
734 page_offset
+= b_offset
;
738 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
739 clen
= STRIPE_SIZE
- page_offset
;
744 b_offset
+= bvl
->bv_offset
;
745 bio_page
= bvl
->bv_page
;
747 tx
= async_memcpy(page
, bio_page
, page_offset
,
748 b_offset
, clen
, &submit
);
750 tx
= async_memcpy(bio_page
, page
, b_offset
,
751 page_offset
, clen
, &submit
);
753 /* chain the operations */
754 submit
.depend_tx
= tx
;
756 if (clen
< len
) /* hit end of page */
764 static void ops_complete_biofill(void *stripe_head_ref
)
766 struct stripe_head
*sh
= stripe_head_ref
;
767 struct bio
*return_bi
= NULL
;
770 pr_debug("%s: stripe %llu\n", __func__
,
771 (unsigned long long)sh
->sector
);
773 /* clear completed biofills */
774 for (i
= sh
->disks
; i
--; ) {
775 struct r5dev
*dev
= &sh
->dev
[i
];
777 /* acknowledge completion of a biofill operation */
778 /* and check if we need to reply to a read request,
779 * new R5_Wantfill requests are held off until
780 * !STRIPE_BIOFILL_RUN
782 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
783 struct bio
*rbi
, *rbi2
;
788 while (rbi
&& rbi
->bi_sector
<
789 dev
->sector
+ STRIPE_SECTORS
) {
790 rbi2
= r5_next_bio(rbi
, dev
->sector
);
791 if (!raid5_dec_bi_active_stripes(rbi
)) {
792 rbi
->bi_next
= return_bi
;
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 async_submit_ctl submit
;
813 pr_debug("%s: stripe %llu\n", __func__
,
814 (unsigned long long)sh
->sector
);
816 for (i
= sh
->disks
; i
--; ) {
817 struct r5dev
*dev
= &sh
->dev
[i
];
818 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
820 spin_lock_irq(&sh
->stripe_lock
);
821 dev
->read
= rbi
= dev
->toread
;
823 spin_unlock_irq(&sh
->stripe_lock
);
824 while (rbi
&& rbi
->bi_sector
<
825 dev
->sector
+ STRIPE_SECTORS
) {
826 tx
= async_copy_data(0, rbi
, dev
->page
,
828 rbi
= r5_next_bio(rbi
, dev
->sector
);
833 atomic_inc(&sh
->count
);
834 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
835 async_trigger_callback(&submit
);
838 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
845 tgt
= &sh
->dev
[target
];
846 set_bit(R5_UPTODATE
, &tgt
->flags
);
847 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
848 clear_bit(R5_Wantcompute
, &tgt
->flags
);
851 static void ops_complete_compute(void *stripe_head_ref
)
853 struct stripe_head
*sh
= stripe_head_ref
;
855 pr_debug("%s: stripe %llu\n", __func__
,
856 (unsigned long long)sh
->sector
);
858 /* mark the computed target(s) as uptodate */
859 mark_target_uptodate(sh
, sh
->ops
.target
);
860 mark_target_uptodate(sh
, sh
->ops
.target2
);
862 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
863 if (sh
->check_state
== check_state_compute_run
)
864 sh
->check_state
= check_state_compute_result
;
865 set_bit(STRIPE_HANDLE
, &sh
->state
);
869 /* return a pointer to the address conversion region of the scribble buffer */
870 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
871 struct raid5_percpu
*percpu
)
873 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
876 static struct dma_async_tx_descriptor
*
877 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
879 int disks
= sh
->disks
;
880 struct page
**xor_srcs
= percpu
->scribble
;
881 int target
= sh
->ops
.target
;
882 struct r5dev
*tgt
= &sh
->dev
[target
];
883 struct page
*xor_dest
= tgt
->page
;
885 struct dma_async_tx_descriptor
*tx
;
886 struct async_submit_ctl submit
;
889 pr_debug("%s: stripe %llu block: %d\n",
890 __func__
, (unsigned long long)sh
->sector
, target
);
891 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
893 for (i
= disks
; i
--; )
895 xor_srcs
[count
++] = sh
->dev
[i
].page
;
897 atomic_inc(&sh
->count
);
899 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
900 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
901 if (unlikely(count
== 1))
902 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
904 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
909 /* set_syndrome_sources - populate source buffers for gen_syndrome
910 * @srcs - (struct page *) array of size sh->disks
911 * @sh - stripe_head to parse
913 * Populates srcs in proper layout order for the stripe and returns the
914 * 'count' of sources to be used in a call to async_gen_syndrome. The P
915 * destination buffer is recorded in srcs[count] and the Q destination
916 * is recorded in srcs[count+1]].
918 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
920 int disks
= sh
->disks
;
921 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
922 int d0_idx
= raid6_d0(sh
);
926 for (i
= 0; i
< disks
; i
++)
932 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
934 srcs
[slot
] = sh
->dev
[i
].page
;
935 i
= raid6_next_disk(i
, disks
);
936 } while (i
!= d0_idx
);
938 return syndrome_disks
;
941 static struct dma_async_tx_descriptor
*
942 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
944 int disks
= sh
->disks
;
945 struct page
**blocks
= percpu
->scribble
;
947 int qd_idx
= sh
->qd_idx
;
948 struct dma_async_tx_descriptor
*tx
;
949 struct async_submit_ctl submit
;
955 if (sh
->ops
.target
< 0)
956 target
= sh
->ops
.target2
;
957 else if (sh
->ops
.target2
< 0)
958 target
= sh
->ops
.target
;
960 /* we should only have one valid target */
963 pr_debug("%s: stripe %llu block: %d\n",
964 __func__
, (unsigned long long)sh
->sector
, target
);
966 tgt
= &sh
->dev
[target
];
967 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
970 atomic_inc(&sh
->count
);
972 if (target
== qd_idx
) {
973 count
= set_syndrome_sources(blocks
, sh
);
974 blocks
[count
] = NULL
; /* regenerating p is not necessary */
975 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
976 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
977 ops_complete_compute
, sh
,
978 to_addr_conv(sh
, percpu
));
979 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
981 /* Compute any data- or p-drive using XOR */
983 for (i
= disks
; i
-- ; ) {
984 if (i
== target
|| i
== qd_idx
)
986 blocks
[count
++] = sh
->dev
[i
].page
;
989 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
990 NULL
, ops_complete_compute
, sh
,
991 to_addr_conv(sh
, percpu
));
992 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
998 static struct dma_async_tx_descriptor
*
999 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1001 int i
, count
, disks
= sh
->disks
;
1002 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1003 int d0_idx
= raid6_d0(sh
);
1004 int faila
= -1, failb
= -1;
1005 int target
= sh
->ops
.target
;
1006 int target2
= sh
->ops
.target2
;
1007 struct r5dev
*tgt
= &sh
->dev
[target
];
1008 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1009 struct dma_async_tx_descriptor
*tx
;
1010 struct page
**blocks
= percpu
->scribble
;
1011 struct async_submit_ctl submit
;
1013 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1014 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1015 BUG_ON(target
< 0 || target2
< 0);
1016 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1017 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1019 /* we need to open-code set_syndrome_sources to handle the
1020 * slot number conversion for 'faila' and 'failb'
1022 for (i
= 0; i
< disks
; i
++)
1027 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1029 blocks
[slot
] = sh
->dev
[i
].page
;
1035 i
= raid6_next_disk(i
, disks
);
1036 } while (i
!= d0_idx
);
1038 BUG_ON(faila
== failb
);
1041 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1042 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1044 atomic_inc(&sh
->count
);
1046 if (failb
== syndrome_disks
+1) {
1047 /* Q disk is one of the missing disks */
1048 if (faila
== syndrome_disks
) {
1049 /* Missing P+Q, just recompute */
1050 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1051 ops_complete_compute
, sh
,
1052 to_addr_conv(sh
, percpu
));
1053 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1054 STRIPE_SIZE
, &submit
);
1058 int qd_idx
= sh
->qd_idx
;
1060 /* Missing D+Q: recompute D from P, then recompute Q */
1061 if (target
== qd_idx
)
1062 data_target
= target2
;
1064 data_target
= target
;
1067 for (i
= disks
; i
-- ; ) {
1068 if (i
== data_target
|| i
== qd_idx
)
1070 blocks
[count
++] = sh
->dev
[i
].page
;
1072 dest
= sh
->dev
[data_target
].page
;
1073 init_async_submit(&submit
,
1074 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1076 to_addr_conv(sh
, percpu
));
1077 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1080 count
= set_syndrome_sources(blocks
, sh
);
1081 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1082 ops_complete_compute
, sh
,
1083 to_addr_conv(sh
, percpu
));
1084 return async_gen_syndrome(blocks
, 0, count
+2,
1085 STRIPE_SIZE
, &submit
);
1088 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1089 ops_complete_compute
, sh
,
1090 to_addr_conv(sh
, percpu
));
1091 if (failb
== syndrome_disks
) {
1092 /* We're missing D+P. */
1093 return async_raid6_datap_recov(syndrome_disks
+2,
1097 /* We're missing D+D. */
1098 return async_raid6_2data_recov(syndrome_disks
+2,
1099 STRIPE_SIZE
, faila
, failb
,
1106 static void ops_complete_prexor(void *stripe_head_ref
)
1108 struct stripe_head
*sh
= stripe_head_ref
;
1110 pr_debug("%s: stripe %llu\n", __func__
,
1111 (unsigned long long)sh
->sector
);
1114 static struct dma_async_tx_descriptor
*
1115 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1116 struct dma_async_tx_descriptor
*tx
)
1118 int disks
= sh
->disks
;
1119 struct page
**xor_srcs
= percpu
->scribble
;
1120 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1121 struct async_submit_ctl submit
;
1123 /* existing parity data subtracted */
1124 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1126 pr_debug("%s: stripe %llu\n", __func__
,
1127 (unsigned long long)sh
->sector
);
1129 for (i
= disks
; i
--; ) {
1130 struct r5dev
*dev
= &sh
->dev
[i
];
1131 /* Only process blocks that are known to be uptodate */
1132 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1133 xor_srcs
[count
++] = dev
->page
;
1136 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1137 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1138 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1143 static struct dma_async_tx_descriptor
*
1144 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1146 int disks
= sh
->disks
;
1149 pr_debug("%s: stripe %llu\n", __func__
,
1150 (unsigned long long)sh
->sector
);
1152 for (i
= disks
; i
--; ) {
1153 struct r5dev
*dev
= &sh
->dev
[i
];
1156 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1159 spin_lock_irq(&sh
->stripe_lock
);
1160 chosen
= dev
->towrite
;
1161 dev
->towrite
= NULL
;
1162 BUG_ON(dev
->written
);
1163 wbi
= dev
->written
= chosen
;
1164 spin_unlock_irq(&sh
->stripe_lock
);
1166 while (wbi
&& wbi
->bi_sector
<
1167 dev
->sector
+ STRIPE_SECTORS
) {
1168 if (wbi
->bi_rw
& REQ_FUA
)
1169 set_bit(R5_WantFUA
, &dev
->flags
);
1170 if (wbi
->bi_rw
& REQ_SYNC
)
1171 set_bit(R5_SyncIO
, &dev
->flags
);
1172 tx
= async_copy_data(1, wbi
, dev
->page
,
1174 wbi
= r5_next_bio(wbi
, dev
->sector
);
1182 static void ops_complete_reconstruct(void *stripe_head_ref
)
1184 struct stripe_head
*sh
= stripe_head_ref
;
1185 int disks
= sh
->disks
;
1186 int pd_idx
= sh
->pd_idx
;
1187 int qd_idx
= sh
->qd_idx
;
1189 bool fua
= false, sync
= false;
1191 pr_debug("%s: stripe %llu\n", __func__
,
1192 (unsigned long long)sh
->sector
);
1194 for (i
= disks
; i
--; ) {
1195 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1196 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1199 for (i
= disks
; i
--; ) {
1200 struct r5dev
*dev
= &sh
->dev
[i
];
1202 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1203 set_bit(R5_UPTODATE
, &dev
->flags
);
1205 set_bit(R5_WantFUA
, &dev
->flags
);
1207 set_bit(R5_SyncIO
, &dev
->flags
);
1211 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1212 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1213 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1214 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1216 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1217 sh
->reconstruct_state
= reconstruct_state_result
;
1220 set_bit(STRIPE_HANDLE
, &sh
->state
);
1225 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1226 struct dma_async_tx_descriptor
*tx
)
1228 int disks
= sh
->disks
;
1229 struct page
**xor_srcs
= percpu
->scribble
;
1230 struct async_submit_ctl submit
;
1231 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1232 struct page
*xor_dest
;
1234 unsigned long flags
;
1236 pr_debug("%s: stripe %llu\n", __func__
,
1237 (unsigned long long)sh
->sector
);
1239 /* check if prexor is active which means only process blocks
1240 * that are part of a read-modify-write (written)
1242 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1244 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1245 for (i
= disks
; i
--; ) {
1246 struct r5dev
*dev
= &sh
->dev
[i
];
1248 xor_srcs
[count
++] = dev
->page
;
1251 xor_dest
= sh
->dev
[pd_idx
].page
;
1252 for (i
= disks
; i
--; ) {
1253 struct r5dev
*dev
= &sh
->dev
[i
];
1255 xor_srcs
[count
++] = dev
->page
;
1259 /* 1/ if we prexor'd then the dest is reused as a source
1260 * 2/ if we did not prexor then we are redoing the parity
1261 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1262 * for the synchronous xor case
1264 flags
= ASYNC_TX_ACK
|
1265 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1267 atomic_inc(&sh
->count
);
1269 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1270 to_addr_conv(sh
, percpu
));
1271 if (unlikely(count
== 1))
1272 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1274 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1278 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1279 struct dma_async_tx_descriptor
*tx
)
1281 struct async_submit_ctl submit
;
1282 struct page
**blocks
= percpu
->scribble
;
1285 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1287 count
= set_syndrome_sources(blocks
, sh
);
1289 atomic_inc(&sh
->count
);
1291 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1292 sh
, to_addr_conv(sh
, percpu
));
1293 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1296 static void ops_complete_check(void *stripe_head_ref
)
1298 struct stripe_head
*sh
= stripe_head_ref
;
1300 pr_debug("%s: stripe %llu\n", __func__
,
1301 (unsigned long long)sh
->sector
);
1303 sh
->check_state
= check_state_check_result
;
1304 set_bit(STRIPE_HANDLE
, &sh
->state
);
1308 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1310 int disks
= sh
->disks
;
1311 int pd_idx
= sh
->pd_idx
;
1312 int qd_idx
= sh
->qd_idx
;
1313 struct page
*xor_dest
;
1314 struct page
**xor_srcs
= percpu
->scribble
;
1315 struct dma_async_tx_descriptor
*tx
;
1316 struct async_submit_ctl submit
;
1320 pr_debug("%s: stripe %llu\n", __func__
,
1321 (unsigned long long)sh
->sector
);
1324 xor_dest
= sh
->dev
[pd_idx
].page
;
1325 xor_srcs
[count
++] = xor_dest
;
1326 for (i
= disks
; i
--; ) {
1327 if (i
== pd_idx
|| i
== qd_idx
)
1329 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1332 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1333 to_addr_conv(sh
, percpu
));
1334 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1335 &sh
->ops
.zero_sum_result
, &submit
);
1337 atomic_inc(&sh
->count
);
1338 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1339 tx
= async_trigger_callback(&submit
);
1342 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1344 struct page
**srcs
= percpu
->scribble
;
1345 struct async_submit_ctl submit
;
1348 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1349 (unsigned long long)sh
->sector
, checkp
);
1351 count
= set_syndrome_sources(srcs
, sh
);
1355 atomic_inc(&sh
->count
);
1356 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1357 sh
, to_addr_conv(sh
, percpu
));
1358 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1359 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1362 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1364 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1365 struct dma_async_tx_descriptor
*tx
= NULL
;
1366 struct r5conf
*conf
= sh
->raid_conf
;
1367 int level
= conf
->level
;
1368 struct raid5_percpu
*percpu
;
1372 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1373 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1374 ops_run_biofill(sh
);
1378 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1380 tx
= ops_run_compute5(sh
, percpu
);
1382 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1383 tx
= ops_run_compute6_1(sh
, percpu
);
1385 tx
= ops_run_compute6_2(sh
, percpu
);
1387 /* terminate the chain if reconstruct is not set to be run */
1388 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1392 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1393 tx
= ops_run_prexor(sh
, percpu
, tx
);
1395 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1396 tx
= ops_run_biodrain(sh
, tx
);
1400 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1402 ops_run_reconstruct5(sh
, percpu
, tx
);
1404 ops_run_reconstruct6(sh
, percpu
, tx
);
1407 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1408 if (sh
->check_state
== check_state_run
)
1409 ops_run_check_p(sh
, percpu
);
1410 else if (sh
->check_state
== check_state_run_q
)
1411 ops_run_check_pq(sh
, percpu
, 0);
1412 else if (sh
->check_state
== check_state_run_pq
)
1413 ops_run_check_pq(sh
, percpu
, 1);
1419 for (i
= disks
; i
--; ) {
1420 struct r5dev
*dev
= &sh
->dev
[i
];
1421 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1422 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1427 #ifdef CONFIG_MULTICORE_RAID456
1428 static void async_run_ops(void *param
, async_cookie_t cookie
)
1430 struct stripe_head
*sh
= param
;
1431 unsigned long ops_request
= sh
->ops
.request
;
1433 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1434 wake_up(&sh
->ops
.wait_for_ops
);
1436 __raid_run_ops(sh
, ops_request
);
1440 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1442 /* since handle_stripe can be called outside of raid5d context
1443 * we need to ensure sh->ops.request is de-staged before another
1446 wait_event(sh
->ops
.wait_for_ops
,
1447 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1448 sh
->ops
.request
= ops_request
;
1450 atomic_inc(&sh
->count
);
1451 async_schedule(async_run_ops
, sh
);
1454 #define raid_run_ops __raid_run_ops
1457 static int grow_one_stripe(struct r5conf
*conf
)
1459 struct stripe_head
*sh
;
1460 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1464 sh
->raid_conf
= conf
;
1465 #ifdef CONFIG_MULTICORE_RAID456
1466 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1469 spin_lock_init(&sh
->stripe_lock
);
1471 if (grow_buffers(sh
)) {
1473 kmem_cache_free(conf
->slab_cache
, sh
);
1476 /* we just created an active stripe so... */
1477 atomic_set(&sh
->count
, 1);
1478 atomic_inc(&conf
->active_stripes
);
1479 INIT_LIST_HEAD(&sh
->lru
);
1484 static int grow_stripes(struct r5conf
*conf
, int num
)
1486 struct kmem_cache
*sc
;
1487 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1489 if (conf
->mddev
->gendisk
)
1490 sprintf(conf
->cache_name
[0],
1491 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1493 sprintf(conf
->cache_name
[0],
1494 "raid%d-%p", conf
->level
, conf
->mddev
);
1495 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1497 conf
->active_name
= 0;
1498 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1499 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1503 conf
->slab_cache
= sc
;
1504 conf
->pool_size
= devs
;
1506 if (!grow_one_stripe(conf
))
1512 * scribble_len - return the required size of the scribble region
1513 * @num - total number of disks in the array
1515 * The size must be enough to contain:
1516 * 1/ a struct page pointer for each device in the array +2
1517 * 2/ room to convert each entry in (1) to its corresponding dma
1518 * (dma_map_page()) or page (page_address()) address.
1520 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1521 * calculate over all devices (not just the data blocks), using zeros in place
1522 * of the P and Q blocks.
1524 static size_t scribble_len(int num
)
1528 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1533 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1535 /* Make all the stripes able to hold 'newsize' devices.
1536 * New slots in each stripe get 'page' set to a new page.
1538 * This happens in stages:
1539 * 1/ create a new kmem_cache and allocate the required number of
1541 * 2/ gather all the old stripe_heads and tranfer the pages across
1542 * to the new stripe_heads. This will have the side effect of
1543 * freezing the array as once all stripe_heads have been collected,
1544 * no IO will be possible. Old stripe heads are freed once their
1545 * pages have been transferred over, and the old kmem_cache is
1546 * freed when all stripes are done.
1547 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1548 * we simple return a failre status - no need to clean anything up.
1549 * 4/ allocate new pages for the new slots in the new stripe_heads.
1550 * If this fails, we don't bother trying the shrink the
1551 * stripe_heads down again, we just leave them as they are.
1552 * As each stripe_head is processed the new one is released into
1555 * Once step2 is started, we cannot afford to wait for a write,
1556 * so we use GFP_NOIO allocations.
1558 struct stripe_head
*osh
, *nsh
;
1559 LIST_HEAD(newstripes
);
1560 struct disk_info
*ndisks
;
1563 struct kmem_cache
*sc
;
1566 if (newsize
<= conf
->pool_size
)
1567 return 0; /* never bother to shrink */
1569 err
= md_allow_write(conf
->mddev
);
1574 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1575 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1580 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1581 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1585 nsh
->raid_conf
= conf
;
1586 #ifdef CONFIG_MULTICORE_RAID456
1587 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1590 list_add(&nsh
->lru
, &newstripes
);
1593 /* didn't get enough, give up */
1594 while (!list_empty(&newstripes
)) {
1595 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1596 list_del(&nsh
->lru
);
1597 kmem_cache_free(sc
, nsh
);
1599 kmem_cache_destroy(sc
);
1602 /* Step 2 - Must use GFP_NOIO now.
1603 * OK, we have enough stripes, start collecting inactive
1604 * stripes and copying them over
1606 list_for_each_entry(nsh
, &newstripes
, lru
) {
1607 spin_lock_irq(&conf
->device_lock
);
1608 wait_event_lock_irq(conf
->wait_for_stripe
,
1609 !list_empty(&conf
->inactive_list
),
1612 osh
= get_free_stripe(conf
);
1613 spin_unlock_irq(&conf
->device_lock
);
1614 atomic_set(&nsh
->count
, 1);
1615 for(i
=0; i
<conf
->pool_size
; i
++)
1616 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1617 for( ; i
<newsize
; i
++)
1618 nsh
->dev
[i
].page
= NULL
;
1619 kmem_cache_free(conf
->slab_cache
, osh
);
1621 kmem_cache_destroy(conf
->slab_cache
);
1624 * At this point, we are holding all the stripes so the array
1625 * is completely stalled, so now is a good time to resize
1626 * conf->disks and the scribble region
1628 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1630 for (i
=0; i
<conf
->raid_disks
; i
++)
1631 ndisks
[i
] = conf
->disks
[i
];
1633 conf
->disks
= ndisks
;
1638 conf
->scribble_len
= scribble_len(newsize
);
1639 for_each_present_cpu(cpu
) {
1640 struct raid5_percpu
*percpu
;
1643 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1644 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1647 kfree(percpu
->scribble
);
1648 percpu
->scribble
= scribble
;
1656 /* Step 4, return new stripes to service */
1657 while(!list_empty(&newstripes
)) {
1658 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1659 list_del_init(&nsh
->lru
);
1661 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1662 if (nsh
->dev
[i
].page
== NULL
) {
1663 struct page
*p
= alloc_page(GFP_NOIO
);
1664 nsh
->dev
[i
].page
= p
;
1668 release_stripe(nsh
);
1670 /* critical section pass, GFP_NOIO no longer needed */
1672 conf
->slab_cache
= sc
;
1673 conf
->active_name
= 1-conf
->active_name
;
1674 conf
->pool_size
= newsize
;
1678 static int drop_one_stripe(struct r5conf
*conf
)
1680 struct stripe_head
*sh
;
1682 spin_lock_irq(&conf
->device_lock
);
1683 sh
= get_free_stripe(conf
);
1684 spin_unlock_irq(&conf
->device_lock
);
1687 BUG_ON(atomic_read(&sh
->count
));
1689 kmem_cache_free(conf
->slab_cache
, sh
);
1690 atomic_dec(&conf
->active_stripes
);
1694 static void shrink_stripes(struct r5conf
*conf
)
1696 while (drop_one_stripe(conf
))
1699 if (conf
->slab_cache
)
1700 kmem_cache_destroy(conf
->slab_cache
);
1701 conf
->slab_cache
= NULL
;
1704 static void raid5_end_read_request(struct bio
* bi
, int error
)
1706 struct stripe_head
*sh
= bi
->bi_private
;
1707 struct r5conf
*conf
= sh
->raid_conf
;
1708 int disks
= sh
->disks
, i
;
1709 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1710 char b
[BDEVNAME_SIZE
];
1711 struct md_rdev
*rdev
= NULL
;
1714 for (i
=0 ; i
<disks
; i
++)
1715 if (bi
== &sh
->dev
[i
].req
)
1718 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1719 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1725 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1726 /* If replacement finished while this request was outstanding,
1727 * 'replacement' might be NULL already.
1728 * In that case it moved down to 'rdev'.
1729 * rdev is not removed until all requests are finished.
1731 rdev
= conf
->disks
[i
].replacement
;
1733 rdev
= conf
->disks
[i
].rdev
;
1735 if (use_new_offset(conf
, sh
))
1736 s
= sh
->sector
+ rdev
->new_data_offset
;
1738 s
= sh
->sector
+ rdev
->data_offset
;
1740 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1741 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1742 /* Note that this cannot happen on a
1743 * replacement device. We just fail those on
1748 "md/raid:%s: read error corrected"
1749 " (%lu sectors at %llu on %s)\n",
1750 mdname(conf
->mddev
), STRIPE_SECTORS
,
1751 (unsigned long long)s
,
1752 bdevname(rdev
->bdev
, b
));
1753 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1754 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1755 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1756 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1757 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1759 if (atomic_read(&rdev
->read_errors
))
1760 atomic_set(&rdev
->read_errors
, 0);
1762 const char *bdn
= bdevname(rdev
->bdev
, b
);
1766 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1767 atomic_inc(&rdev
->read_errors
);
1768 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1771 "md/raid:%s: read error on replacement device "
1772 "(sector %llu on %s).\n",
1773 mdname(conf
->mddev
),
1774 (unsigned long long)s
,
1776 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1780 "md/raid:%s: read error not correctable "
1781 "(sector %llu on %s).\n",
1782 mdname(conf
->mddev
),
1783 (unsigned long long)s
,
1785 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1790 "md/raid:%s: read error NOT corrected!! "
1791 "(sector %llu on %s).\n",
1792 mdname(conf
->mddev
),
1793 (unsigned long long)s
,
1795 } else if (atomic_read(&rdev
->read_errors
)
1796 > conf
->max_nr_stripes
)
1798 "md/raid:%s: Too many read errors, failing device %s.\n",
1799 mdname(conf
->mddev
), bdn
);
1803 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1804 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1805 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1807 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1809 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1810 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1812 && test_bit(In_sync
, &rdev
->flags
)
1813 && rdev_set_badblocks(
1814 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1815 md_error(conf
->mddev
, rdev
);
1818 rdev_dec_pending(rdev
, conf
->mddev
);
1819 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1820 set_bit(STRIPE_HANDLE
, &sh
->state
);
1824 static void raid5_end_write_request(struct bio
*bi
, int error
)
1826 struct stripe_head
*sh
= bi
->bi_private
;
1827 struct r5conf
*conf
= sh
->raid_conf
;
1828 int disks
= sh
->disks
, i
;
1829 struct md_rdev
*uninitialized_var(rdev
);
1830 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1833 int replacement
= 0;
1835 for (i
= 0 ; i
< disks
; i
++) {
1836 if (bi
== &sh
->dev
[i
].req
) {
1837 rdev
= conf
->disks
[i
].rdev
;
1840 if (bi
== &sh
->dev
[i
].rreq
) {
1841 rdev
= conf
->disks
[i
].replacement
;
1845 /* rdev was removed and 'replacement'
1846 * replaced it. rdev is not removed
1847 * until all requests are finished.
1849 rdev
= conf
->disks
[i
].rdev
;
1853 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1854 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1863 md_error(conf
->mddev
, rdev
);
1864 else if (is_badblock(rdev
, sh
->sector
,
1866 &first_bad
, &bad_sectors
))
1867 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1870 set_bit(WriteErrorSeen
, &rdev
->flags
);
1871 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1872 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1873 set_bit(MD_RECOVERY_NEEDED
,
1874 &rdev
->mddev
->recovery
);
1875 } else if (is_badblock(rdev
, sh
->sector
,
1877 &first_bad
, &bad_sectors
))
1878 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1880 rdev_dec_pending(rdev
, conf
->mddev
);
1882 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1883 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1884 set_bit(STRIPE_HANDLE
, &sh
->state
);
1888 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1890 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1892 struct r5dev
*dev
= &sh
->dev
[i
];
1894 bio_init(&dev
->req
);
1895 dev
->req
.bi_io_vec
= &dev
->vec
;
1897 dev
->req
.bi_max_vecs
++;
1898 dev
->req
.bi_private
= sh
;
1899 dev
->vec
.bv_page
= dev
->page
;
1901 bio_init(&dev
->rreq
);
1902 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1903 dev
->rreq
.bi_vcnt
++;
1904 dev
->rreq
.bi_max_vecs
++;
1905 dev
->rreq
.bi_private
= sh
;
1906 dev
->rvec
.bv_page
= dev
->page
;
1909 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1912 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1914 char b
[BDEVNAME_SIZE
];
1915 struct r5conf
*conf
= mddev
->private;
1916 unsigned long flags
;
1917 pr_debug("raid456: error called\n");
1919 spin_lock_irqsave(&conf
->device_lock
, flags
);
1920 clear_bit(In_sync
, &rdev
->flags
);
1921 mddev
->degraded
= calc_degraded(conf
);
1922 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1923 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1925 set_bit(Blocked
, &rdev
->flags
);
1926 set_bit(Faulty
, &rdev
->flags
);
1927 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1929 "md/raid:%s: Disk failure on %s, disabling device.\n"
1930 "md/raid:%s: Operation continuing on %d devices.\n",
1932 bdevname(rdev
->bdev
, b
),
1934 conf
->raid_disks
- mddev
->degraded
);
1938 * Input: a 'big' sector number,
1939 * Output: index of the data and parity disk, and the sector # in them.
1941 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1942 int previous
, int *dd_idx
,
1943 struct stripe_head
*sh
)
1945 sector_t stripe
, stripe2
;
1946 sector_t chunk_number
;
1947 unsigned int chunk_offset
;
1950 sector_t new_sector
;
1951 int algorithm
= previous
? conf
->prev_algo
1953 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1954 : conf
->chunk_sectors
;
1955 int raid_disks
= previous
? conf
->previous_raid_disks
1957 int data_disks
= raid_disks
- conf
->max_degraded
;
1959 /* First compute the information on this sector */
1962 * Compute the chunk number and the sector offset inside the chunk
1964 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1965 chunk_number
= r_sector
;
1968 * Compute the stripe number
1970 stripe
= chunk_number
;
1971 *dd_idx
= sector_div(stripe
, data_disks
);
1974 * Select the parity disk based on the user selected algorithm.
1976 pd_idx
= qd_idx
= -1;
1977 switch(conf
->level
) {
1979 pd_idx
= data_disks
;
1982 switch (algorithm
) {
1983 case ALGORITHM_LEFT_ASYMMETRIC
:
1984 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1985 if (*dd_idx
>= pd_idx
)
1988 case ALGORITHM_RIGHT_ASYMMETRIC
:
1989 pd_idx
= sector_div(stripe2
, raid_disks
);
1990 if (*dd_idx
>= pd_idx
)
1993 case ALGORITHM_LEFT_SYMMETRIC
:
1994 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1995 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1997 case ALGORITHM_RIGHT_SYMMETRIC
:
1998 pd_idx
= sector_div(stripe2
, raid_disks
);
1999 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2001 case ALGORITHM_PARITY_0
:
2005 case ALGORITHM_PARITY_N
:
2006 pd_idx
= data_disks
;
2014 switch (algorithm
) {
2015 case ALGORITHM_LEFT_ASYMMETRIC
:
2016 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2017 qd_idx
= pd_idx
+ 1;
2018 if (pd_idx
== raid_disks
-1) {
2019 (*dd_idx
)++; /* Q D D D P */
2021 } else if (*dd_idx
>= pd_idx
)
2022 (*dd_idx
) += 2; /* D D P Q D */
2024 case ALGORITHM_RIGHT_ASYMMETRIC
:
2025 pd_idx
= sector_div(stripe2
, raid_disks
);
2026 qd_idx
= pd_idx
+ 1;
2027 if (pd_idx
== raid_disks
-1) {
2028 (*dd_idx
)++; /* Q D D D P */
2030 } else if (*dd_idx
>= pd_idx
)
2031 (*dd_idx
) += 2; /* D D P Q D */
2033 case ALGORITHM_LEFT_SYMMETRIC
:
2034 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2035 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2036 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2038 case ALGORITHM_RIGHT_SYMMETRIC
:
2039 pd_idx
= sector_div(stripe2
, raid_disks
);
2040 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2041 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2044 case ALGORITHM_PARITY_0
:
2049 case ALGORITHM_PARITY_N
:
2050 pd_idx
= data_disks
;
2051 qd_idx
= data_disks
+ 1;
2054 case ALGORITHM_ROTATING_ZERO_RESTART
:
2055 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2056 * of blocks for computing Q is different.
2058 pd_idx
= sector_div(stripe2
, raid_disks
);
2059 qd_idx
= pd_idx
+ 1;
2060 if (pd_idx
== raid_disks
-1) {
2061 (*dd_idx
)++; /* Q D D D P */
2063 } else if (*dd_idx
>= pd_idx
)
2064 (*dd_idx
) += 2; /* D D P Q D */
2068 case ALGORITHM_ROTATING_N_RESTART
:
2069 /* Same a left_asymmetric, by first stripe is
2070 * D D D P Q rather than
2074 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2075 qd_idx
= pd_idx
+ 1;
2076 if (pd_idx
== raid_disks
-1) {
2077 (*dd_idx
)++; /* Q D D D P */
2079 } else if (*dd_idx
>= pd_idx
)
2080 (*dd_idx
) += 2; /* D D P Q D */
2084 case ALGORITHM_ROTATING_N_CONTINUE
:
2085 /* Same as left_symmetric but Q is before P */
2086 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2087 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2088 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2092 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2093 /* RAID5 left_asymmetric, with Q on last device */
2094 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2095 if (*dd_idx
>= pd_idx
)
2097 qd_idx
= raid_disks
- 1;
2100 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2101 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2102 if (*dd_idx
>= pd_idx
)
2104 qd_idx
= raid_disks
- 1;
2107 case ALGORITHM_LEFT_SYMMETRIC_6
:
2108 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2109 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2110 qd_idx
= raid_disks
- 1;
2113 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2114 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2115 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2116 qd_idx
= raid_disks
- 1;
2119 case ALGORITHM_PARITY_0_6
:
2122 qd_idx
= raid_disks
- 1;
2132 sh
->pd_idx
= pd_idx
;
2133 sh
->qd_idx
= qd_idx
;
2134 sh
->ddf_layout
= ddf_layout
;
2137 * Finally, compute the new sector number
2139 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2144 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2146 struct r5conf
*conf
= sh
->raid_conf
;
2147 int raid_disks
= sh
->disks
;
2148 int data_disks
= raid_disks
- conf
->max_degraded
;
2149 sector_t new_sector
= sh
->sector
, check
;
2150 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2151 : conf
->chunk_sectors
;
2152 int algorithm
= previous
? conf
->prev_algo
2156 sector_t chunk_number
;
2157 int dummy1
, dd_idx
= i
;
2159 struct stripe_head sh2
;
2162 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2163 stripe
= new_sector
;
2165 if (i
== sh
->pd_idx
)
2167 switch(conf
->level
) {
2170 switch (algorithm
) {
2171 case ALGORITHM_LEFT_ASYMMETRIC
:
2172 case ALGORITHM_RIGHT_ASYMMETRIC
:
2176 case ALGORITHM_LEFT_SYMMETRIC
:
2177 case ALGORITHM_RIGHT_SYMMETRIC
:
2180 i
-= (sh
->pd_idx
+ 1);
2182 case ALGORITHM_PARITY_0
:
2185 case ALGORITHM_PARITY_N
:
2192 if (i
== sh
->qd_idx
)
2193 return 0; /* It is the Q disk */
2194 switch (algorithm
) {
2195 case ALGORITHM_LEFT_ASYMMETRIC
:
2196 case ALGORITHM_RIGHT_ASYMMETRIC
:
2197 case ALGORITHM_ROTATING_ZERO_RESTART
:
2198 case ALGORITHM_ROTATING_N_RESTART
:
2199 if (sh
->pd_idx
== raid_disks
-1)
2200 i
--; /* Q D D D P */
2201 else if (i
> sh
->pd_idx
)
2202 i
-= 2; /* D D P Q D */
2204 case ALGORITHM_LEFT_SYMMETRIC
:
2205 case ALGORITHM_RIGHT_SYMMETRIC
:
2206 if (sh
->pd_idx
== raid_disks
-1)
2207 i
--; /* Q D D D P */
2212 i
-= (sh
->pd_idx
+ 2);
2215 case ALGORITHM_PARITY_0
:
2218 case ALGORITHM_PARITY_N
:
2220 case ALGORITHM_ROTATING_N_CONTINUE
:
2221 /* Like left_symmetric, but P is before Q */
2222 if (sh
->pd_idx
== 0)
2223 i
--; /* P D D D Q */
2228 i
-= (sh
->pd_idx
+ 1);
2231 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2232 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2236 case ALGORITHM_LEFT_SYMMETRIC_6
:
2237 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2239 i
+= data_disks
+ 1;
2240 i
-= (sh
->pd_idx
+ 1);
2242 case ALGORITHM_PARITY_0_6
:
2251 chunk_number
= stripe
* data_disks
+ i
;
2252 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2254 check
= raid5_compute_sector(conf
, r_sector
,
2255 previous
, &dummy1
, &sh2
);
2256 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2257 || sh2
.qd_idx
!= sh
->qd_idx
) {
2258 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2259 mdname(conf
->mddev
));
2267 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2268 int rcw
, int expand
)
2270 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2271 struct r5conf
*conf
= sh
->raid_conf
;
2272 int level
= conf
->level
;
2275 /* if we are not expanding this is a proper write request, and
2276 * there will be bios with new data to be drained into the
2280 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2281 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2283 sh
->reconstruct_state
= reconstruct_state_run
;
2285 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2287 for (i
= disks
; i
--; ) {
2288 struct r5dev
*dev
= &sh
->dev
[i
];
2291 set_bit(R5_LOCKED
, &dev
->flags
);
2292 set_bit(R5_Wantdrain
, &dev
->flags
);
2294 clear_bit(R5_UPTODATE
, &dev
->flags
);
2298 if (s
->locked
+ conf
->max_degraded
== disks
)
2299 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2300 atomic_inc(&conf
->pending_full_writes
);
2303 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2304 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2306 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2307 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2308 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2309 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2311 for (i
= disks
; i
--; ) {
2312 struct r5dev
*dev
= &sh
->dev
[i
];
2317 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2318 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2319 set_bit(R5_Wantdrain
, &dev
->flags
);
2320 set_bit(R5_LOCKED
, &dev
->flags
);
2321 clear_bit(R5_UPTODATE
, &dev
->flags
);
2327 /* keep the parity disk(s) locked while asynchronous operations
2330 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2331 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2335 int qd_idx
= sh
->qd_idx
;
2336 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2338 set_bit(R5_LOCKED
, &dev
->flags
);
2339 clear_bit(R5_UPTODATE
, &dev
->flags
);
2343 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2344 __func__
, (unsigned long long)sh
->sector
,
2345 s
->locked
, s
->ops_request
);
2349 * Each stripe/dev can have one or more bion attached.
2350 * toread/towrite point to the first in a chain.
2351 * The bi_next chain must be in order.
2353 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2356 struct r5conf
*conf
= sh
->raid_conf
;
2359 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2360 (unsigned long long)bi
->bi_sector
,
2361 (unsigned long long)sh
->sector
);
2364 * If several bio share a stripe. The bio bi_phys_segments acts as a
2365 * reference count to avoid race. The reference count should already be
2366 * increased before this function is called (for example, in
2367 * make_request()), so other bio sharing this stripe will not free the
2368 * stripe. If a stripe is owned by one stripe, the stripe lock will
2371 spin_lock_irq(&sh
->stripe_lock
);
2373 bip
= &sh
->dev
[dd_idx
].towrite
;
2377 bip
= &sh
->dev
[dd_idx
].toread
;
2378 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2379 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2381 bip
= & (*bip
)->bi_next
;
2383 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2386 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2390 raid5_inc_bi_active_stripes(bi
);
2393 /* check if page is covered */
2394 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2395 for (bi
=sh
->dev
[dd_idx
].towrite
;
2396 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2397 bi
&& bi
->bi_sector
<= sector
;
2398 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2399 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2400 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2402 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2403 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2405 spin_unlock_irq(&sh
->stripe_lock
);
2407 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2408 (unsigned long long)(*bip
)->bi_sector
,
2409 (unsigned long long)sh
->sector
, dd_idx
);
2411 if (conf
->mddev
->bitmap
&& firstwrite
) {
2412 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2414 sh
->bm_seq
= conf
->seq_flush
+1;
2415 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2420 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2421 spin_unlock_irq(&sh
->stripe_lock
);
2425 static void end_reshape(struct r5conf
*conf
);
2427 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2428 struct stripe_head
*sh
)
2430 int sectors_per_chunk
=
2431 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2433 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2434 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2436 raid5_compute_sector(conf
,
2437 stripe
* (disks
- conf
->max_degraded
)
2438 *sectors_per_chunk
+ chunk_offset
,
2444 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2445 struct stripe_head_state
*s
, int disks
,
2446 struct bio
**return_bi
)
2449 for (i
= disks
; i
--; ) {
2453 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2454 struct md_rdev
*rdev
;
2456 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2457 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2458 atomic_inc(&rdev
->nr_pending
);
2463 if (!rdev_set_badblocks(
2467 md_error(conf
->mddev
, rdev
);
2468 rdev_dec_pending(rdev
, conf
->mddev
);
2471 spin_lock_irq(&sh
->stripe_lock
);
2472 /* fail all writes first */
2473 bi
= sh
->dev
[i
].towrite
;
2474 sh
->dev
[i
].towrite
= NULL
;
2475 spin_unlock_irq(&sh
->stripe_lock
);
2481 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2482 wake_up(&conf
->wait_for_overlap
);
2484 while (bi
&& bi
->bi_sector
<
2485 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2486 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2487 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2488 if (!raid5_dec_bi_active_stripes(bi
)) {
2489 md_write_end(conf
->mddev
);
2490 bi
->bi_next
= *return_bi
;
2496 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2497 STRIPE_SECTORS
, 0, 0);
2499 /* and fail all 'written' */
2500 bi
= sh
->dev
[i
].written
;
2501 sh
->dev
[i
].written
= NULL
;
2502 if (bi
) bitmap_end
= 1;
2503 while (bi
&& bi
->bi_sector
<
2504 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2505 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2506 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2507 if (!raid5_dec_bi_active_stripes(bi
)) {
2508 md_write_end(conf
->mddev
);
2509 bi
->bi_next
= *return_bi
;
2515 /* fail any reads if this device is non-operational and
2516 * the data has not reached the cache yet.
2518 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2519 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2520 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2521 bi
= sh
->dev
[i
].toread
;
2522 sh
->dev
[i
].toread
= NULL
;
2523 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2524 wake_up(&conf
->wait_for_overlap
);
2525 if (bi
) s
->to_read
--;
2526 while (bi
&& bi
->bi_sector
<
2527 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2528 struct bio
*nextbi
=
2529 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2530 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2531 if (!raid5_dec_bi_active_stripes(bi
)) {
2532 bi
->bi_next
= *return_bi
;
2539 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2540 STRIPE_SECTORS
, 0, 0);
2541 /* If we were in the middle of a write the parity block might
2542 * still be locked - so just clear all R5_LOCKED flags
2544 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2547 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2548 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2549 md_wakeup_thread(conf
->mddev
->thread
);
2553 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2554 struct stripe_head_state
*s
)
2559 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2562 /* There is nothing more to do for sync/check/repair.
2563 * Don't even need to abort as that is handled elsewhere
2564 * if needed, and not always wanted e.g. if there is a known
2566 * For recover/replace we need to record a bad block on all
2567 * non-sync devices, or abort the recovery
2569 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2570 /* During recovery devices cannot be removed, so
2571 * locking and refcounting of rdevs is not needed
2573 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2574 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2576 && !test_bit(Faulty
, &rdev
->flags
)
2577 && !test_bit(In_sync
, &rdev
->flags
)
2578 && !rdev_set_badblocks(rdev
, sh
->sector
,
2581 rdev
= conf
->disks
[i
].replacement
;
2583 && !test_bit(Faulty
, &rdev
->flags
)
2584 && !test_bit(In_sync
, &rdev
->flags
)
2585 && !rdev_set_badblocks(rdev
, sh
->sector
,
2590 conf
->recovery_disabled
=
2591 conf
->mddev
->recovery_disabled
;
2593 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2596 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2598 struct md_rdev
*rdev
;
2600 /* Doing recovery so rcu locking not required */
2601 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2603 && !test_bit(Faulty
, &rdev
->flags
)
2604 && !test_bit(In_sync
, &rdev
->flags
)
2605 && (rdev
->recovery_offset
<= sh
->sector
2606 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2612 /* fetch_block - checks the given member device to see if its data needs
2613 * to be read or computed to satisfy a request.
2615 * Returns 1 when no more member devices need to be checked, otherwise returns
2616 * 0 to tell the loop in handle_stripe_fill to continue
2618 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2619 int disk_idx
, int disks
)
2621 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2622 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2623 &sh
->dev
[s
->failed_num
[1]] };
2625 /* is the data in this block needed, and can we get it? */
2626 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2627 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2629 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2630 s
->syncing
|| s
->expanding
||
2631 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2632 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2633 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2634 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2635 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2636 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2637 /* we would like to get this block, possibly by computing it,
2638 * otherwise read it if the backing disk is insync
2640 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2641 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2642 if ((s
->uptodate
== disks
- 1) &&
2643 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2644 disk_idx
== s
->failed_num
[1]))) {
2645 /* have disk failed, and we're requested to fetch it;
2648 pr_debug("Computing stripe %llu block %d\n",
2649 (unsigned long long)sh
->sector
, disk_idx
);
2650 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2651 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2652 set_bit(R5_Wantcompute
, &dev
->flags
);
2653 sh
->ops
.target
= disk_idx
;
2654 sh
->ops
.target2
= -1; /* no 2nd target */
2656 /* Careful: from this point on 'uptodate' is in the eye
2657 * of raid_run_ops which services 'compute' operations
2658 * before writes. R5_Wantcompute flags a block that will
2659 * be R5_UPTODATE by the time it is needed for a
2660 * subsequent operation.
2664 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2665 /* Computing 2-failure is *very* expensive; only
2666 * do it if failed >= 2
2669 for (other
= disks
; other
--; ) {
2670 if (other
== disk_idx
)
2672 if (!test_bit(R5_UPTODATE
,
2673 &sh
->dev
[other
].flags
))
2677 pr_debug("Computing stripe %llu blocks %d,%d\n",
2678 (unsigned long long)sh
->sector
,
2680 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2681 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2682 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2683 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2684 sh
->ops
.target
= disk_idx
;
2685 sh
->ops
.target2
= other
;
2689 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2690 set_bit(R5_LOCKED
, &dev
->flags
);
2691 set_bit(R5_Wantread
, &dev
->flags
);
2693 pr_debug("Reading block %d (sync=%d)\n",
2694 disk_idx
, s
->syncing
);
2702 * handle_stripe_fill - read or compute data to satisfy pending requests.
2704 static void handle_stripe_fill(struct stripe_head
*sh
,
2705 struct stripe_head_state
*s
,
2710 /* look for blocks to read/compute, skip this if a compute
2711 * is already in flight, or if the stripe contents are in the
2712 * midst of changing due to a write
2714 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2715 !sh
->reconstruct_state
)
2716 for (i
= disks
; i
--; )
2717 if (fetch_block(sh
, s
, i
, disks
))
2719 set_bit(STRIPE_HANDLE
, &sh
->state
);
2723 /* handle_stripe_clean_event
2724 * any written block on an uptodate or failed drive can be returned.
2725 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2726 * never LOCKED, so we don't need to test 'failed' directly.
2728 static void handle_stripe_clean_event(struct r5conf
*conf
,
2729 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2734 for (i
= disks
; i
--; )
2735 if (sh
->dev
[i
].written
) {
2737 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2738 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2739 /* We can return any write requests */
2740 struct bio
*wbi
, *wbi2
;
2741 pr_debug("Return write for disc %d\n", i
);
2743 dev
->written
= NULL
;
2744 while (wbi
&& wbi
->bi_sector
<
2745 dev
->sector
+ STRIPE_SECTORS
) {
2746 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2747 if (!raid5_dec_bi_active_stripes(wbi
)) {
2748 md_write_end(conf
->mddev
);
2749 wbi
->bi_next
= *return_bi
;
2754 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2756 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2761 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2762 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2763 md_wakeup_thread(conf
->mddev
->thread
);
2766 static void handle_stripe_dirtying(struct r5conf
*conf
,
2767 struct stripe_head
*sh
,
2768 struct stripe_head_state
*s
,
2771 int rmw
= 0, rcw
= 0, i
;
2772 if (conf
->max_degraded
== 2) {
2773 /* RAID6 requires 'rcw' in current implementation
2774 * Calculate the real rcw later - for now fake it
2775 * look like rcw is cheaper
2778 } else for (i
= disks
; i
--; ) {
2779 /* would I have to read this buffer for read_modify_write */
2780 struct r5dev
*dev
= &sh
->dev
[i
];
2781 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2782 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2783 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2784 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2785 if (test_bit(R5_Insync
, &dev
->flags
))
2788 rmw
+= 2*disks
; /* cannot read it */
2790 /* Would I have to read this buffer for reconstruct_write */
2791 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2792 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2793 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2794 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2795 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2800 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2801 (unsigned long long)sh
->sector
, rmw
, rcw
);
2802 set_bit(STRIPE_HANDLE
, &sh
->state
);
2803 if (rmw
< rcw
&& rmw
> 0)
2804 /* prefer read-modify-write, but need to get some data */
2805 for (i
= disks
; i
--; ) {
2806 struct r5dev
*dev
= &sh
->dev
[i
];
2807 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2808 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2809 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2810 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2811 test_bit(R5_Insync
, &dev
->flags
)) {
2813 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2814 pr_debug("Read_old block "
2815 "%d for r-m-w\n", i
);
2816 set_bit(R5_LOCKED
, &dev
->flags
);
2817 set_bit(R5_Wantread
, &dev
->flags
);
2820 set_bit(STRIPE_DELAYED
, &sh
->state
);
2821 set_bit(STRIPE_HANDLE
, &sh
->state
);
2825 if (rcw
<= rmw
&& rcw
> 0) {
2826 /* want reconstruct write, but need to get some data */
2828 for (i
= disks
; i
--; ) {
2829 struct r5dev
*dev
= &sh
->dev
[i
];
2830 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2831 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2832 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2833 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2834 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2836 if (!test_bit(R5_Insync
, &dev
->flags
))
2837 continue; /* it's a failed drive */
2839 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2840 pr_debug("Read_old block "
2841 "%d for Reconstruct\n", i
);
2842 set_bit(R5_LOCKED
, &dev
->flags
);
2843 set_bit(R5_Wantread
, &dev
->flags
);
2846 set_bit(STRIPE_DELAYED
, &sh
->state
);
2847 set_bit(STRIPE_HANDLE
, &sh
->state
);
2852 /* now if nothing is locked, and if we have enough data,
2853 * we can start a write request
2855 /* since handle_stripe can be called at any time we need to handle the
2856 * case where a compute block operation has been submitted and then a
2857 * subsequent call wants to start a write request. raid_run_ops only
2858 * handles the case where compute block and reconstruct are requested
2859 * simultaneously. If this is not the case then new writes need to be
2860 * held off until the compute completes.
2862 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2863 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2864 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2865 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2868 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2869 struct stripe_head_state
*s
, int disks
)
2871 struct r5dev
*dev
= NULL
;
2873 set_bit(STRIPE_HANDLE
, &sh
->state
);
2875 switch (sh
->check_state
) {
2876 case check_state_idle
:
2877 /* start a new check operation if there are no failures */
2878 if (s
->failed
== 0) {
2879 BUG_ON(s
->uptodate
!= disks
);
2880 sh
->check_state
= check_state_run
;
2881 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2882 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2886 dev
= &sh
->dev
[s
->failed_num
[0]];
2888 case check_state_compute_result
:
2889 sh
->check_state
= check_state_idle
;
2891 dev
= &sh
->dev
[sh
->pd_idx
];
2893 /* check that a write has not made the stripe insync */
2894 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2897 /* either failed parity check, or recovery is happening */
2898 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2899 BUG_ON(s
->uptodate
!= disks
);
2901 set_bit(R5_LOCKED
, &dev
->flags
);
2903 set_bit(R5_Wantwrite
, &dev
->flags
);
2905 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2906 set_bit(STRIPE_INSYNC
, &sh
->state
);
2908 case check_state_run
:
2909 break; /* we will be called again upon completion */
2910 case check_state_check_result
:
2911 sh
->check_state
= check_state_idle
;
2913 /* if a failure occurred during the check operation, leave
2914 * STRIPE_INSYNC not set and let the stripe be handled again
2919 /* handle a successful check operation, if parity is correct
2920 * we are done. Otherwise update the mismatch count and repair
2921 * parity if !MD_RECOVERY_CHECK
2923 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2924 /* parity is correct (on disc,
2925 * not in buffer any more)
2927 set_bit(STRIPE_INSYNC
, &sh
->state
);
2929 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2930 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2931 /* don't try to repair!! */
2932 set_bit(STRIPE_INSYNC
, &sh
->state
);
2934 sh
->check_state
= check_state_compute_run
;
2935 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2936 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2937 set_bit(R5_Wantcompute
,
2938 &sh
->dev
[sh
->pd_idx
].flags
);
2939 sh
->ops
.target
= sh
->pd_idx
;
2940 sh
->ops
.target2
= -1;
2945 case check_state_compute_run
:
2948 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2949 __func__
, sh
->check_state
,
2950 (unsigned long long) sh
->sector
);
2956 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
2957 struct stripe_head_state
*s
,
2960 int pd_idx
= sh
->pd_idx
;
2961 int qd_idx
= sh
->qd_idx
;
2964 set_bit(STRIPE_HANDLE
, &sh
->state
);
2966 BUG_ON(s
->failed
> 2);
2968 /* Want to check and possibly repair P and Q.
2969 * However there could be one 'failed' device, in which
2970 * case we can only check one of them, possibly using the
2971 * other to generate missing data
2974 switch (sh
->check_state
) {
2975 case check_state_idle
:
2976 /* start a new check operation if there are < 2 failures */
2977 if (s
->failed
== s
->q_failed
) {
2978 /* The only possible failed device holds Q, so it
2979 * makes sense to check P (If anything else were failed,
2980 * we would have used P to recreate it).
2982 sh
->check_state
= check_state_run
;
2984 if (!s
->q_failed
&& s
->failed
< 2) {
2985 /* Q is not failed, and we didn't use it to generate
2986 * anything, so it makes sense to check it
2988 if (sh
->check_state
== check_state_run
)
2989 sh
->check_state
= check_state_run_pq
;
2991 sh
->check_state
= check_state_run_q
;
2994 /* discard potentially stale zero_sum_result */
2995 sh
->ops
.zero_sum_result
= 0;
2997 if (sh
->check_state
== check_state_run
) {
2998 /* async_xor_zero_sum destroys the contents of P */
2999 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3002 if (sh
->check_state
>= check_state_run
&&
3003 sh
->check_state
<= check_state_run_pq
) {
3004 /* async_syndrome_zero_sum preserves P and Q, so
3005 * no need to mark them !uptodate here
3007 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3011 /* we have 2-disk failure */
3012 BUG_ON(s
->failed
!= 2);
3014 case check_state_compute_result
:
3015 sh
->check_state
= check_state_idle
;
3017 /* check that a write has not made the stripe insync */
3018 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3021 /* now write out any block on a failed drive,
3022 * or P or Q if they were recomputed
3024 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3025 if (s
->failed
== 2) {
3026 dev
= &sh
->dev
[s
->failed_num
[1]];
3028 set_bit(R5_LOCKED
, &dev
->flags
);
3029 set_bit(R5_Wantwrite
, &dev
->flags
);
3031 if (s
->failed
>= 1) {
3032 dev
= &sh
->dev
[s
->failed_num
[0]];
3034 set_bit(R5_LOCKED
, &dev
->flags
);
3035 set_bit(R5_Wantwrite
, &dev
->flags
);
3037 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3038 dev
= &sh
->dev
[pd_idx
];
3040 set_bit(R5_LOCKED
, &dev
->flags
);
3041 set_bit(R5_Wantwrite
, &dev
->flags
);
3043 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3044 dev
= &sh
->dev
[qd_idx
];
3046 set_bit(R5_LOCKED
, &dev
->flags
);
3047 set_bit(R5_Wantwrite
, &dev
->flags
);
3049 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3051 set_bit(STRIPE_INSYNC
, &sh
->state
);
3053 case check_state_run
:
3054 case check_state_run_q
:
3055 case check_state_run_pq
:
3056 break; /* we will be called again upon completion */
3057 case check_state_check_result
:
3058 sh
->check_state
= check_state_idle
;
3060 /* handle a successful check operation, if parity is correct
3061 * we are done. Otherwise update the mismatch count and repair
3062 * parity if !MD_RECOVERY_CHECK
3064 if (sh
->ops
.zero_sum_result
== 0) {
3065 /* both parities are correct */
3067 set_bit(STRIPE_INSYNC
, &sh
->state
);
3069 /* in contrast to the raid5 case we can validate
3070 * parity, but still have a failure to write
3073 sh
->check_state
= check_state_compute_result
;
3074 /* Returning at this point means that we may go
3075 * off and bring p and/or q uptodate again so
3076 * we make sure to check zero_sum_result again
3077 * to verify if p or q need writeback
3081 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
3082 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3083 /* don't try to repair!! */
3084 set_bit(STRIPE_INSYNC
, &sh
->state
);
3086 int *target
= &sh
->ops
.target
;
3088 sh
->ops
.target
= -1;
3089 sh
->ops
.target2
= -1;
3090 sh
->check_state
= check_state_compute_run
;
3091 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3092 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3093 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3094 set_bit(R5_Wantcompute
,
3095 &sh
->dev
[pd_idx
].flags
);
3097 target
= &sh
->ops
.target2
;
3100 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3101 set_bit(R5_Wantcompute
,
3102 &sh
->dev
[qd_idx
].flags
);
3109 case check_state_compute_run
:
3112 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3113 __func__
, sh
->check_state
,
3114 (unsigned long long) sh
->sector
);
3119 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3123 /* We have read all the blocks in this stripe and now we need to
3124 * copy some of them into a target stripe for expand.
3126 struct dma_async_tx_descriptor
*tx
= NULL
;
3127 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3128 for (i
= 0; i
< sh
->disks
; i
++)
3129 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3131 struct stripe_head
*sh2
;
3132 struct async_submit_ctl submit
;
3134 sector_t bn
= compute_blocknr(sh
, i
, 1);
3135 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3137 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3139 /* so far only the early blocks of this stripe
3140 * have been requested. When later blocks
3141 * get requested, we will try again
3144 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3145 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3146 /* must have already done this block */
3147 release_stripe(sh2
);
3151 /* place all the copies on one channel */
3152 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3153 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3154 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3157 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3158 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3159 for (j
= 0; j
< conf
->raid_disks
; j
++)
3160 if (j
!= sh2
->pd_idx
&&
3162 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3164 if (j
== conf
->raid_disks
) {
3165 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3166 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3168 release_stripe(sh2
);
3171 /* done submitting copies, wait for them to complete */
3174 dma_wait_for_async_tx(tx
);
3179 * handle_stripe - do things to a stripe.
3181 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3182 * state of various bits to see what needs to be done.
3184 * return some read requests which now have data
3185 * return some write requests which are safely on storage
3186 * schedule a read on some buffers
3187 * schedule a write of some buffers
3188 * return confirmation of parity correctness
3192 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3194 struct r5conf
*conf
= sh
->raid_conf
;
3195 int disks
= sh
->disks
;
3198 int do_recovery
= 0;
3200 memset(s
, 0, sizeof(*s
));
3202 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3203 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3204 s
->failed_num
[0] = -1;
3205 s
->failed_num
[1] = -1;
3207 /* Now to look around and see what can be done */
3209 for (i
=disks
; i
--; ) {
3210 struct md_rdev
*rdev
;
3217 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3219 dev
->toread
, dev
->towrite
, dev
->written
);
3220 /* maybe we can reply to a read
3222 * new wantfill requests are only permitted while
3223 * ops_complete_biofill is guaranteed to be inactive
3225 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3226 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3227 set_bit(R5_Wantfill
, &dev
->flags
);
3229 /* now count some things */
3230 if (test_bit(R5_LOCKED
, &dev
->flags
))
3232 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3234 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3236 BUG_ON(s
->compute
> 2);
3239 if (test_bit(R5_Wantfill
, &dev
->flags
))
3241 else if (dev
->toread
)
3245 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3250 /* Prefer to use the replacement for reads, but only
3251 * if it is recovered enough and has no bad blocks.
3253 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3254 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3255 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3256 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3257 &first_bad
, &bad_sectors
))
3258 set_bit(R5_ReadRepl
, &dev
->flags
);
3261 set_bit(R5_NeedReplace
, &dev
->flags
);
3262 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3263 clear_bit(R5_ReadRepl
, &dev
->flags
);
3265 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3268 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3269 &first_bad
, &bad_sectors
);
3270 if (s
->blocked_rdev
== NULL
3271 && (test_bit(Blocked
, &rdev
->flags
)
3274 set_bit(BlockedBadBlocks
,
3276 s
->blocked_rdev
= rdev
;
3277 atomic_inc(&rdev
->nr_pending
);
3280 clear_bit(R5_Insync
, &dev
->flags
);
3284 /* also not in-sync */
3285 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3286 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3287 /* treat as in-sync, but with a read error
3288 * which we can now try to correct
3290 set_bit(R5_Insync
, &dev
->flags
);
3291 set_bit(R5_ReadError
, &dev
->flags
);
3293 } else if (test_bit(In_sync
, &rdev
->flags
))
3294 set_bit(R5_Insync
, &dev
->flags
);
3295 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3296 /* in sync if before recovery_offset */
3297 set_bit(R5_Insync
, &dev
->flags
);
3298 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3299 test_bit(R5_Expanded
, &dev
->flags
))
3300 /* If we've reshaped into here, we assume it is Insync.
3301 * We will shortly update recovery_offset to make
3304 set_bit(R5_Insync
, &dev
->flags
);
3306 if (rdev
&& test_bit(R5_WriteError
, &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
);
3312 clear_bit(R5_Insync
, &dev
->flags
);
3313 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3314 s
->handle_bad_blocks
= 1;
3315 atomic_inc(&rdev2
->nr_pending
);
3317 clear_bit(R5_WriteError
, &dev
->flags
);
3319 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3320 /* This flag does not apply to '.replacement'
3321 * only to .rdev, so make sure to check that*/
3322 struct md_rdev
*rdev2
= rcu_dereference(
3323 conf
->disks
[i
].rdev
);
3324 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3325 s
->handle_bad_blocks
= 1;
3326 atomic_inc(&rdev2
->nr_pending
);
3328 clear_bit(R5_MadeGood
, &dev
->flags
);
3330 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3331 struct md_rdev
*rdev2
= rcu_dereference(
3332 conf
->disks
[i
].replacement
);
3333 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3334 s
->handle_bad_blocks
= 1;
3335 atomic_inc(&rdev2
->nr_pending
);
3337 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3339 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3340 /* The ReadError flag will just be confusing now */
3341 clear_bit(R5_ReadError
, &dev
->flags
);
3342 clear_bit(R5_ReWrite
, &dev
->flags
);
3344 if (test_bit(R5_ReadError
, &dev
->flags
))
3345 clear_bit(R5_Insync
, &dev
->flags
);
3346 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3348 s
->failed_num
[s
->failed
] = i
;
3350 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3354 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3355 /* If there is a failed device being replaced,
3356 * we must be recovering.
3357 * else if we are after recovery_cp, we must be syncing
3358 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3359 * else we can only be replacing
3360 * sync and recovery both need to read all devices, and so
3361 * use the same flag.
3364 sh
->sector
>= conf
->mddev
->recovery_cp
||
3365 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3373 static void handle_stripe(struct stripe_head
*sh
)
3375 struct stripe_head_state s
;
3376 struct r5conf
*conf
= sh
->raid_conf
;
3379 int disks
= sh
->disks
;
3380 struct r5dev
*pdev
, *qdev
;
3382 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3383 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3384 /* already being handled, ensure it gets handled
3385 * again when current action finishes */
3386 set_bit(STRIPE_HANDLE
, &sh
->state
);
3390 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3391 set_bit(STRIPE_SYNCING
, &sh
->state
);
3392 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3394 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3396 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3397 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3398 (unsigned long long)sh
->sector
, sh
->state
,
3399 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3400 sh
->check_state
, sh
->reconstruct_state
);
3402 analyse_stripe(sh
, &s
);
3404 if (s
.handle_bad_blocks
) {
3405 set_bit(STRIPE_HANDLE
, &sh
->state
);
3409 if (unlikely(s
.blocked_rdev
)) {
3410 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3411 s
.replacing
|| s
.to_write
|| s
.written
) {
3412 set_bit(STRIPE_HANDLE
, &sh
->state
);
3415 /* There is nothing for the blocked_rdev to block */
3416 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3417 s
.blocked_rdev
= NULL
;
3420 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3421 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3422 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3425 pr_debug("locked=%d uptodate=%d to_read=%d"
3426 " to_write=%d failed=%d failed_num=%d,%d\n",
3427 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3428 s
.failed_num
[0], s
.failed_num
[1]);
3429 /* check if the array has lost more than max_degraded devices and,
3430 * if so, some requests might need to be failed.
3432 if (s
.failed
> conf
->max_degraded
) {
3433 sh
->check_state
= 0;
3434 sh
->reconstruct_state
= 0;
3435 if (s
.to_read
+s
.to_write
+s
.written
)
3436 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3437 if (s
.syncing
+ s
.replacing
)
3438 handle_failed_sync(conf
, sh
, &s
);
3442 * might be able to return some write requests if the parity blocks
3443 * are safe, or on a failed drive
3445 pdev
= &sh
->dev
[sh
->pd_idx
];
3446 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3447 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3448 qdev
= &sh
->dev
[sh
->qd_idx
];
3449 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3450 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3454 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3455 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3456 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3457 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3458 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3459 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3460 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3462 /* Now we might consider reading some blocks, either to check/generate
3463 * parity, or to satisfy requests
3464 * or to load a block that is being partially written.
3466 if (s
.to_read
|| s
.non_overwrite
3467 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3468 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3471 handle_stripe_fill(sh
, &s
, disks
);
3473 /* Now we check to see if any write operations have recently
3477 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3479 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3480 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3481 sh
->reconstruct_state
= reconstruct_state_idle
;
3483 /* All the 'written' buffers and the parity block are ready to
3484 * be written back to disk
3486 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3487 BUG_ON(sh
->qd_idx
>= 0 &&
3488 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
));
3489 for (i
= disks
; i
--; ) {
3490 struct r5dev
*dev
= &sh
->dev
[i
];
3491 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3492 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3494 pr_debug("Writing block %d\n", i
);
3495 set_bit(R5_Wantwrite
, &dev
->flags
);
3498 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3499 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3501 set_bit(STRIPE_INSYNC
, &sh
->state
);
3504 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3505 s
.dec_preread_active
= 1;
3508 /* Now to consider new write requests and what else, if anything
3509 * should be read. We do not handle new writes when:
3510 * 1/ A 'write' operation (copy+xor) is already in flight.
3511 * 2/ A 'check' operation is in flight, as it may clobber the parity
3514 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3515 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3517 /* maybe we need to check and possibly fix the parity for this stripe
3518 * Any reads will already have been scheduled, so we just see if enough
3519 * data is available. The parity check is held off while parity
3520 * dependent operations are in flight.
3522 if (sh
->check_state
||
3523 (s
.syncing
&& s
.locked
== 0 &&
3524 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3525 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3526 if (conf
->level
== 6)
3527 handle_parity_checks6(conf
, sh
, &s
, disks
);
3529 handle_parity_checks5(conf
, sh
, &s
, disks
);
3532 if (s
.replacing
&& s
.locked
== 0
3533 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3534 /* Write out to replacement devices where possible */
3535 for (i
= 0; i
< conf
->raid_disks
; i
++)
3536 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3537 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3538 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3539 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3542 set_bit(STRIPE_INSYNC
, &sh
->state
);
3544 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3545 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3546 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3547 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3550 /* If the failed drives are just a ReadError, then we might need
3551 * to progress the repair/check process
3553 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3554 for (i
= 0; i
< s
.failed
; i
++) {
3555 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3556 if (test_bit(R5_ReadError
, &dev
->flags
)
3557 && !test_bit(R5_LOCKED
, &dev
->flags
)
3558 && test_bit(R5_UPTODATE
, &dev
->flags
)
3560 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3561 set_bit(R5_Wantwrite
, &dev
->flags
);
3562 set_bit(R5_ReWrite
, &dev
->flags
);
3563 set_bit(R5_LOCKED
, &dev
->flags
);
3566 /* let's read it back */
3567 set_bit(R5_Wantread
, &dev
->flags
);
3568 set_bit(R5_LOCKED
, &dev
->flags
);
3575 /* Finish reconstruct operations initiated by the expansion process */
3576 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3577 struct stripe_head
*sh_src
3578 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3579 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3580 /* sh cannot be written until sh_src has been read.
3581 * so arrange for sh to be delayed a little
3583 set_bit(STRIPE_DELAYED
, &sh
->state
);
3584 set_bit(STRIPE_HANDLE
, &sh
->state
);
3585 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3587 atomic_inc(&conf
->preread_active_stripes
);
3588 release_stripe(sh_src
);
3592 release_stripe(sh_src
);
3594 sh
->reconstruct_state
= reconstruct_state_idle
;
3595 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3596 for (i
= conf
->raid_disks
; i
--; ) {
3597 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3598 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3603 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3604 !sh
->reconstruct_state
) {
3605 /* Need to write out all blocks after computing parity */
3606 sh
->disks
= conf
->raid_disks
;
3607 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3608 schedule_reconstruction(sh
, &s
, 1, 1);
3609 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3610 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3611 atomic_dec(&conf
->reshape_stripes
);
3612 wake_up(&conf
->wait_for_overlap
);
3613 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3616 if (s
.expanding
&& s
.locked
== 0 &&
3617 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3618 handle_stripe_expansion(conf
, sh
);
3621 /* wait for this device to become unblocked */
3622 if (unlikely(s
.blocked_rdev
)) {
3623 if (conf
->mddev
->external
)
3624 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3627 /* Internal metadata will immediately
3628 * be written by raid5d, so we don't
3629 * need to wait here.
3631 rdev_dec_pending(s
.blocked_rdev
,
3635 if (s
.handle_bad_blocks
)
3636 for (i
= disks
; i
--; ) {
3637 struct md_rdev
*rdev
;
3638 struct r5dev
*dev
= &sh
->dev
[i
];
3639 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3640 /* We own a safe reference to the rdev */
3641 rdev
= conf
->disks
[i
].rdev
;
3642 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3644 md_error(conf
->mddev
, rdev
);
3645 rdev_dec_pending(rdev
, conf
->mddev
);
3647 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3648 rdev
= conf
->disks
[i
].rdev
;
3649 rdev_clear_badblocks(rdev
, sh
->sector
,
3651 rdev_dec_pending(rdev
, conf
->mddev
);
3653 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3654 rdev
= conf
->disks
[i
].replacement
;
3656 /* rdev have been moved down */
3657 rdev
= conf
->disks
[i
].rdev
;
3658 rdev_clear_badblocks(rdev
, sh
->sector
,
3660 rdev_dec_pending(rdev
, conf
->mddev
);
3665 raid_run_ops(sh
, s
.ops_request
);
3669 if (s
.dec_preread_active
) {
3670 /* We delay this until after ops_run_io so that if make_request
3671 * is waiting on a flush, it won't continue until the writes
3672 * have actually been submitted.
3674 atomic_dec(&conf
->preread_active_stripes
);
3675 if (atomic_read(&conf
->preread_active_stripes
) <
3677 md_wakeup_thread(conf
->mddev
->thread
);
3680 return_io(s
.return_bi
);
3682 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3685 static void raid5_activate_delayed(struct r5conf
*conf
)
3687 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3688 while (!list_empty(&conf
->delayed_list
)) {
3689 struct list_head
*l
= conf
->delayed_list
.next
;
3690 struct stripe_head
*sh
;
3691 sh
= list_entry(l
, struct stripe_head
, lru
);
3693 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3694 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3695 atomic_inc(&conf
->preread_active_stripes
);
3696 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3701 static void activate_bit_delay(struct r5conf
*conf
)
3703 /* device_lock is held */
3704 struct list_head head
;
3705 list_add(&head
, &conf
->bitmap_list
);
3706 list_del_init(&conf
->bitmap_list
);
3707 while (!list_empty(&head
)) {
3708 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3709 list_del_init(&sh
->lru
);
3710 atomic_inc(&sh
->count
);
3711 __release_stripe(conf
, sh
);
3715 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3717 struct r5conf
*conf
= mddev
->private;
3719 /* No difference between reads and writes. Just check
3720 * how busy the stripe_cache is
3723 if (conf
->inactive_blocked
)
3727 if (list_empty_careful(&conf
->inactive_list
))
3732 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3734 static int raid5_congested(void *data
, int bits
)
3736 struct mddev
*mddev
= data
;
3738 return mddev_congested(mddev
, bits
) ||
3739 md_raid5_congested(mddev
, bits
);
3742 /* We want read requests to align with chunks where possible,
3743 * but write requests don't need to.
3745 static int raid5_mergeable_bvec(struct request_queue
*q
,
3746 struct bvec_merge_data
*bvm
,
3747 struct bio_vec
*biovec
)
3749 struct mddev
*mddev
= q
->queuedata
;
3750 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3752 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3753 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3755 if ((bvm
->bi_rw
& 1) == WRITE
)
3756 return biovec
->bv_len
; /* always allow writes to be mergeable */
3758 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3759 chunk_sectors
= mddev
->new_chunk_sectors
;
3760 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3761 if (max
< 0) max
= 0;
3762 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3763 return biovec
->bv_len
;
3769 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3771 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3772 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3773 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3775 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3776 chunk_sectors
= mddev
->new_chunk_sectors
;
3777 return chunk_sectors
>=
3778 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3782 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3783 * later sampled by raid5d.
3785 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3787 unsigned long flags
;
3789 spin_lock_irqsave(&conf
->device_lock
, flags
);
3791 bi
->bi_next
= conf
->retry_read_aligned_list
;
3792 conf
->retry_read_aligned_list
= bi
;
3794 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3795 md_wakeup_thread(conf
->mddev
->thread
);
3799 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3803 bi
= conf
->retry_read_aligned
;
3805 conf
->retry_read_aligned
= NULL
;
3808 bi
= conf
->retry_read_aligned_list
;
3810 conf
->retry_read_aligned_list
= bi
->bi_next
;
3813 * this sets the active strip count to 1 and the processed
3814 * strip count to zero (upper 8 bits)
3816 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3824 * The "raid5_align_endio" should check if the read succeeded and if it
3825 * did, call bio_endio on the original bio (having bio_put the new bio
3827 * If the read failed..
3829 static void raid5_align_endio(struct bio
*bi
, int error
)
3831 struct bio
* raid_bi
= bi
->bi_private
;
3832 struct mddev
*mddev
;
3833 struct r5conf
*conf
;
3834 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3835 struct md_rdev
*rdev
;
3839 rdev
= (void*)raid_bi
->bi_next
;
3840 raid_bi
->bi_next
= NULL
;
3841 mddev
= rdev
->mddev
;
3842 conf
= mddev
->private;
3844 rdev_dec_pending(rdev
, conf
->mddev
);
3846 if (!error
&& uptodate
) {
3847 bio_endio(raid_bi
, 0);
3848 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3849 wake_up(&conf
->wait_for_stripe
);
3854 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3856 add_bio_to_retry(raid_bi
, conf
);
3859 static int bio_fits_rdev(struct bio
*bi
)
3861 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3863 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3865 blk_recount_segments(q
, bi
);
3866 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3869 if (q
->merge_bvec_fn
)
3870 /* it's too hard to apply the merge_bvec_fn at this stage,
3879 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3881 struct r5conf
*conf
= mddev
->private;
3883 struct bio
* align_bi
;
3884 struct md_rdev
*rdev
;
3885 sector_t end_sector
;
3887 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3888 pr_debug("chunk_aligned_read : non aligned\n");
3892 * use bio_clone_mddev to make a copy of the bio
3894 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3898 * set bi_end_io to a new function, and set bi_private to the
3901 align_bi
->bi_end_io
= raid5_align_endio
;
3902 align_bi
->bi_private
= raid_bio
;
3906 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3910 end_sector
= align_bi
->bi_sector
+ (align_bi
->bi_size
>> 9);
3912 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3913 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3914 rdev
->recovery_offset
< end_sector
) {
3915 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3917 (test_bit(Faulty
, &rdev
->flags
) ||
3918 !(test_bit(In_sync
, &rdev
->flags
) ||
3919 rdev
->recovery_offset
>= end_sector
)))
3926 atomic_inc(&rdev
->nr_pending
);
3928 raid_bio
->bi_next
= (void*)rdev
;
3929 align_bi
->bi_bdev
= rdev
->bdev
;
3930 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3932 if (!bio_fits_rdev(align_bi
) ||
3933 is_badblock(rdev
, align_bi
->bi_sector
, align_bi
->bi_size
>>9,
3934 &first_bad
, &bad_sectors
)) {
3935 /* too big in some way, or has a known bad block */
3937 rdev_dec_pending(rdev
, mddev
);
3941 /* No reshape active, so we can trust rdev->data_offset */
3942 align_bi
->bi_sector
+= rdev
->data_offset
;
3944 spin_lock_irq(&conf
->device_lock
);
3945 wait_event_lock_irq(conf
->wait_for_stripe
,
3947 conf
->device_lock
, /* nothing */);
3948 atomic_inc(&conf
->active_aligned_reads
);
3949 spin_unlock_irq(&conf
->device_lock
);
3951 generic_make_request(align_bi
);
3960 /* __get_priority_stripe - get the next stripe to process
3962 * Full stripe writes are allowed to pass preread active stripes up until
3963 * the bypass_threshold is exceeded. In general the bypass_count
3964 * increments when the handle_list is handled before the hold_list; however, it
3965 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3966 * stripe with in flight i/o. The bypass_count will be reset when the
3967 * head of the hold_list has changed, i.e. the head was promoted to the
3970 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
3972 struct stripe_head
*sh
;
3974 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3976 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3977 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3978 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3980 if (!list_empty(&conf
->handle_list
)) {
3981 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3983 if (list_empty(&conf
->hold_list
))
3984 conf
->bypass_count
= 0;
3985 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3986 if (conf
->hold_list
.next
== conf
->last_hold
)
3987 conf
->bypass_count
++;
3989 conf
->last_hold
= conf
->hold_list
.next
;
3990 conf
->bypass_count
-= conf
->bypass_threshold
;
3991 if (conf
->bypass_count
< 0)
3992 conf
->bypass_count
= 0;
3995 } else if (!list_empty(&conf
->hold_list
) &&
3996 ((conf
->bypass_threshold
&&
3997 conf
->bypass_count
> conf
->bypass_threshold
) ||
3998 atomic_read(&conf
->pending_full_writes
) == 0)) {
3999 sh
= list_entry(conf
->hold_list
.next
,
4001 conf
->bypass_count
-= conf
->bypass_threshold
;
4002 if (conf
->bypass_count
< 0)
4003 conf
->bypass_count
= 0;
4007 list_del_init(&sh
->lru
);
4008 atomic_inc(&sh
->count
);
4009 BUG_ON(atomic_read(&sh
->count
) != 1);
4013 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4015 struct r5conf
*conf
= mddev
->private;
4017 sector_t new_sector
;
4018 sector_t logical_sector
, last_sector
;
4019 struct stripe_head
*sh
;
4020 const int rw
= bio_data_dir(bi
);
4023 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4024 md_flush_request(mddev
, bi
);
4028 md_write_start(mddev
, bi
);
4031 mddev
->reshape_position
== MaxSector
&&
4032 chunk_aligned_read(mddev
,bi
))
4035 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4036 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4038 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4040 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4046 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4047 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4048 /* spinlock is needed as reshape_progress may be
4049 * 64bit on a 32bit platform, and so it might be
4050 * possible to see a half-updated value
4051 * Of course reshape_progress could change after
4052 * the lock is dropped, so once we get a reference
4053 * to the stripe that we think it is, we will have
4056 spin_lock_irq(&conf
->device_lock
);
4057 if (mddev
->reshape_backwards
4058 ? logical_sector
< conf
->reshape_progress
4059 : logical_sector
>= conf
->reshape_progress
) {
4062 if (mddev
->reshape_backwards
4063 ? logical_sector
< conf
->reshape_safe
4064 : logical_sector
>= conf
->reshape_safe
) {
4065 spin_unlock_irq(&conf
->device_lock
);
4070 spin_unlock_irq(&conf
->device_lock
);
4073 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4076 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4077 (unsigned long long)new_sector
,
4078 (unsigned long long)logical_sector
);
4080 sh
= get_active_stripe(conf
, new_sector
, previous
,
4081 (bi
->bi_rw
&RWA_MASK
), 0);
4083 if (unlikely(previous
)) {
4084 /* expansion might have moved on while waiting for a
4085 * stripe, so we must do the range check again.
4086 * Expansion could still move past after this
4087 * test, but as we are holding a reference to
4088 * 'sh', we know that if that happens,
4089 * STRIPE_EXPANDING will get set and the expansion
4090 * won't proceed until we finish with the stripe.
4093 spin_lock_irq(&conf
->device_lock
);
4094 if (mddev
->reshape_backwards
4095 ? logical_sector
>= conf
->reshape_progress
4096 : logical_sector
< conf
->reshape_progress
)
4097 /* mismatch, need to try again */
4099 spin_unlock_irq(&conf
->device_lock
);
4108 logical_sector
>= mddev
->suspend_lo
&&
4109 logical_sector
< mddev
->suspend_hi
) {
4111 /* As the suspend_* range is controlled by
4112 * userspace, we want an interruptible
4115 flush_signals(current
);
4116 prepare_to_wait(&conf
->wait_for_overlap
,
4117 &w
, TASK_INTERRUPTIBLE
);
4118 if (logical_sector
>= mddev
->suspend_lo
&&
4119 logical_sector
< mddev
->suspend_hi
)
4124 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4125 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4126 /* Stripe is busy expanding or
4127 * add failed due to overlap. Flush everything
4130 md_wakeup_thread(mddev
->thread
);
4135 finish_wait(&conf
->wait_for_overlap
, &w
);
4136 set_bit(STRIPE_HANDLE
, &sh
->state
);
4137 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4138 if ((bi
->bi_rw
& REQ_NOIDLE
) &&
4139 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4140 atomic_inc(&conf
->preread_active_stripes
);
4141 mddev_check_plugged(mddev
);
4144 /* cannot get stripe for read-ahead, just give-up */
4145 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4146 finish_wait(&conf
->wait_for_overlap
, &w
);
4151 remaining
= raid5_dec_bi_active_stripes(bi
);
4152 if (remaining
== 0) {
4155 md_write_end(mddev
);
4161 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4163 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4165 /* reshaping is quite different to recovery/resync so it is
4166 * handled quite separately ... here.
4168 * On each call to sync_request, we gather one chunk worth of
4169 * destination stripes and flag them as expanding.
4170 * Then we find all the source stripes and request reads.
4171 * As the reads complete, handle_stripe will copy the data
4172 * into the destination stripe and release that stripe.
4174 struct r5conf
*conf
= mddev
->private;
4175 struct stripe_head
*sh
;
4176 sector_t first_sector
, last_sector
;
4177 int raid_disks
= conf
->previous_raid_disks
;
4178 int data_disks
= raid_disks
- conf
->max_degraded
;
4179 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4182 sector_t writepos
, readpos
, safepos
;
4183 sector_t stripe_addr
;
4184 int reshape_sectors
;
4185 struct list_head stripes
;
4187 if (sector_nr
== 0) {
4188 /* If restarting in the middle, skip the initial sectors */
4189 if (mddev
->reshape_backwards
&&
4190 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4191 sector_nr
= raid5_size(mddev
, 0, 0)
4192 - conf
->reshape_progress
;
4193 } else if (!mddev
->reshape_backwards
&&
4194 conf
->reshape_progress
> 0)
4195 sector_nr
= conf
->reshape_progress
;
4196 sector_div(sector_nr
, new_data_disks
);
4198 mddev
->curr_resync_completed
= sector_nr
;
4199 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4205 /* We need to process a full chunk at a time.
4206 * If old and new chunk sizes differ, we need to process the
4209 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4210 reshape_sectors
= mddev
->new_chunk_sectors
;
4212 reshape_sectors
= mddev
->chunk_sectors
;
4214 /* We update the metadata at least every 10 seconds, or when
4215 * the data about to be copied would over-write the source of
4216 * the data at the front of the range. i.e. one new_stripe
4217 * along from reshape_progress new_maps to after where
4218 * reshape_safe old_maps to
4220 writepos
= conf
->reshape_progress
;
4221 sector_div(writepos
, new_data_disks
);
4222 readpos
= conf
->reshape_progress
;
4223 sector_div(readpos
, data_disks
);
4224 safepos
= conf
->reshape_safe
;
4225 sector_div(safepos
, data_disks
);
4226 if (mddev
->reshape_backwards
) {
4227 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4228 readpos
+= reshape_sectors
;
4229 safepos
+= reshape_sectors
;
4231 writepos
+= reshape_sectors
;
4232 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4233 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4236 /* Having calculated the 'writepos' possibly use it
4237 * to set 'stripe_addr' which is where we will write to.
4239 if (mddev
->reshape_backwards
) {
4240 BUG_ON(conf
->reshape_progress
== 0);
4241 stripe_addr
= writepos
;
4242 BUG_ON((mddev
->dev_sectors
&
4243 ~((sector_t
)reshape_sectors
- 1))
4244 - reshape_sectors
- stripe_addr
4247 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4248 stripe_addr
= sector_nr
;
4251 /* 'writepos' is the most advanced device address we might write.
4252 * 'readpos' is the least advanced device address we might read.
4253 * 'safepos' is the least address recorded in the metadata as having
4255 * If there is a min_offset_diff, these are adjusted either by
4256 * increasing the safepos/readpos if diff is negative, or
4257 * increasing writepos if diff is positive.
4258 * If 'readpos' is then behind 'writepos', there is no way that we can
4259 * ensure safety in the face of a crash - that must be done by userspace
4260 * making a backup of the data. So in that case there is no particular
4261 * rush to update metadata.
4262 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4263 * update the metadata to advance 'safepos' to match 'readpos' so that
4264 * we can be safe in the event of a crash.
4265 * So we insist on updating metadata if safepos is behind writepos and
4266 * readpos is beyond writepos.
4267 * In any case, update the metadata every 10 seconds.
4268 * Maybe that number should be configurable, but I'm not sure it is
4269 * worth it.... maybe it could be a multiple of safemode_delay???
4271 if (conf
->min_offset_diff
< 0) {
4272 safepos
+= -conf
->min_offset_diff
;
4273 readpos
+= -conf
->min_offset_diff
;
4275 writepos
+= conf
->min_offset_diff
;
4277 if ((mddev
->reshape_backwards
4278 ? (safepos
> writepos
&& readpos
< writepos
)
4279 : (safepos
< writepos
&& readpos
> writepos
)) ||
4280 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4281 /* Cannot proceed until we've updated the superblock... */
4282 wait_event(conf
->wait_for_overlap
,
4283 atomic_read(&conf
->reshape_stripes
)==0);
4284 mddev
->reshape_position
= conf
->reshape_progress
;
4285 mddev
->curr_resync_completed
= sector_nr
;
4286 conf
->reshape_checkpoint
= jiffies
;
4287 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4288 md_wakeup_thread(mddev
->thread
);
4289 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4290 kthread_should_stop());
4291 spin_lock_irq(&conf
->device_lock
);
4292 conf
->reshape_safe
= mddev
->reshape_position
;
4293 spin_unlock_irq(&conf
->device_lock
);
4294 wake_up(&conf
->wait_for_overlap
);
4295 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4298 INIT_LIST_HEAD(&stripes
);
4299 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4301 int skipped_disk
= 0;
4302 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4303 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4304 atomic_inc(&conf
->reshape_stripes
);
4305 /* If any of this stripe is beyond the end of the old
4306 * array, then we need to zero those blocks
4308 for (j
=sh
->disks
; j
--;) {
4310 if (j
== sh
->pd_idx
)
4312 if (conf
->level
== 6 &&
4315 s
= compute_blocknr(sh
, j
, 0);
4316 if (s
< raid5_size(mddev
, 0, 0)) {
4320 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4321 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4322 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4324 if (!skipped_disk
) {
4325 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4326 set_bit(STRIPE_HANDLE
, &sh
->state
);
4328 list_add(&sh
->lru
, &stripes
);
4330 spin_lock_irq(&conf
->device_lock
);
4331 if (mddev
->reshape_backwards
)
4332 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4334 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4335 spin_unlock_irq(&conf
->device_lock
);
4336 /* Ok, those stripe are ready. We can start scheduling
4337 * reads on the source stripes.
4338 * The source stripes are determined by mapping the first and last
4339 * block on the destination stripes.
4342 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4345 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4346 * new_data_disks
- 1),
4348 if (last_sector
>= mddev
->dev_sectors
)
4349 last_sector
= mddev
->dev_sectors
- 1;
4350 while (first_sector
<= last_sector
) {
4351 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4352 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4353 set_bit(STRIPE_HANDLE
, &sh
->state
);
4355 first_sector
+= STRIPE_SECTORS
;
4357 /* Now that the sources are clearly marked, we can release
4358 * the destination stripes
4360 while (!list_empty(&stripes
)) {
4361 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4362 list_del_init(&sh
->lru
);
4365 /* If this takes us to the resync_max point where we have to pause,
4366 * then we need to write out the superblock.
4368 sector_nr
+= reshape_sectors
;
4369 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4370 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4371 /* Cannot proceed until we've updated the superblock... */
4372 wait_event(conf
->wait_for_overlap
,
4373 atomic_read(&conf
->reshape_stripes
) == 0);
4374 mddev
->reshape_position
= conf
->reshape_progress
;
4375 mddev
->curr_resync_completed
= sector_nr
;
4376 conf
->reshape_checkpoint
= jiffies
;
4377 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4378 md_wakeup_thread(mddev
->thread
);
4379 wait_event(mddev
->sb_wait
,
4380 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4381 || kthread_should_stop());
4382 spin_lock_irq(&conf
->device_lock
);
4383 conf
->reshape_safe
= mddev
->reshape_position
;
4384 spin_unlock_irq(&conf
->device_lock
);
4385 wake_up(&conf
->wait_for_overlap
);
4386 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4388 return reshape_sectors
;
4391 /* FIXME go_faster isn't used */
4392 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4394 struct r5conf
*conf
= mddev
->private;
4395 struct stripe_head
*sh
;
4396 sector_t max_sector
= mddev
->dev_sectors
;
4397 sector_t sync_blocks
;
4398 int still_degraded
= 0;
4401 if (sector_nr
>= max_sector
) {
4402 /* just being told to finish up .. nothing much to do */
4404 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4409 if (mddev
->curr_resync
< max_sector
) /* aborted */
4410 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4412 else /* completed sync */
4414 bitmap_close_sync(mddev
->bitmap
);
4419 /* Allow raid5_quiesce to complete */
4420 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4422 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4423 return reshape_request(mddev
, sector_nr
, skipped
);
4425 /* No need to check resync_max as we never do more than one
4426 * stripe, and as resync_max will always be on a chunk boundary,
4427 * if the check in md_do_sync didn't fire, there is no chance
4428 * of overstepping resync_max here
4431 /* if there is too many failed drives and we are trying
4432 * to resync, then assert that we are finished, because there is
4433 * nothing we can do.
4435 if (mddev
->degraded
>= conf
->max_degraded
&&
4436 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4437 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4441 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4442 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4443 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4444 /* we can skip this block, and probably more */
4445 sync_blocks
/= STRIPE_SECTORS
;
4447 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4450 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4452 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4454 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4455 /* make sure we don't swamp the stripe cache if someone else
4456 * is trying to get access
4458 schedule_timeout_uninterruptible(1);
4460 /* Need to check if array will still be degraded after recovery/resync
4461 * We don't need to check the 'failed' flag as when that gets set,
4464 for (i
= 0; i
< conf
->raid_disks
; i
++)
4465 if (conf
->disks
[i
].rdev
== NULL
)
4468 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4470 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4475 return STRIPE_SECTORS
;
4478 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4480 /* We may not be able to submit a whole bio at once as there
4481 * may not be enough stripe_heads available.
4482 * We cannot pre-allocate enough stripe_heads as we may need
4483 * more than exist in the cache (if we allow ever large chunks).
4484 * So we do one stripe head at a time and record in
4485 * ->bi_hw_segments how many have been done.
4487 * We *know* that this entire raid_bio is in one chunk, so
4488 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4490 struct stripe_head
*sh
;
4492 sector_t sector
, logical_sector
, last_sector
;
4497 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4498 sector
= raid5_compute_sector(conf
, logical_sector
,
4500 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4502 for (; logical_sector
< last_sector
;
4503 logical_sector
+= STRIPE_SECTORS
,
4504 sector
+= STRIPE_SECTORS
,
4507 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4508 /* already done this stripe */
4511 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4514 /* failed to get a stripe - must wait */
4515 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4516 conf
->retry_read_aligned
= raid_bio
;
4520 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4522 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4523 conf
->retry_read_aligned
= raid_bio
;
4527 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4532 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4534 bio_endio(raid_bio
, 0);
4535 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4536 wake_up(&conf
->wait_for_stripe
);
4542 * This is our raid5 kernel thread.
4544 * We scan the hash table for stripes which can be handled now.
4545 * During the scan, completed stripes are saved for us by the interrupt
4546 * handler, so that they will not have to wait for our next wakeup.
4548 static void raid5d(struct mddev
*mddev
)
4550 struct stripe_head
*sh
;
4551 struct r5conf
*conf
= mddev
->private;
4553 struct blk_plug plug
;
4555 pr_debug("+++ raid5d active\n");
4557 md_check_recovery(mddev
);
4559 blk_start_plug(&plug
);
4561 spin_lock_irq(&conf
->device_lock
);
4566 !list_empty(&conf
->bitmap_list
)) {
4567 /* Now is a good time to flush some bitmap updates */
4569 spin_unlock_irq(&conf
->device_lock
);
4570 bitmap_unplug(mddev
->bitmap
);
4571 spin_lock_irq(&conf
->device_lock
);
4572 conf
->seq_write
= conf
->seq_flush
;
4573 activate_bit_delay(conf
);
4575 raid5_activate_delayed(conf
);
4577 while ((bio
= remove_bio_from_retry(conf
))) {
4579 spin_unlock_irq(&conf
->device_lock
);
4580 ok
= retry_aligned_read(conf
, bio
);
4581 spin_lock_irq(&conf
->device_lock
);
4587 sh
= __get_priority_stripe(conf
);
4591 spin_unlock_irq(&conf
->device_lock
);
4598 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
4599 md_check_recovery(mddev
);
4601 spin_lock_irq(&conf
->device_lock
);
4603 pr_debug("%d stripes handled\n", handled
);
4605 spin_unlock_irq(&conf
->device_lock
);
4607 async_tx_issue_pending_all();
4608 blk_finish_plug(&plug
);
4610 pr_debug("--- raid5d inactive\n");
4614 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4616 struct r5conf
*conf
= mddev
->private;
4618 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4624 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4626 struct r5conf
*conf
= mddev
->private;
4629 if (size
<= 16 || size
> 32768)
4631 while (size
< conf
->max_nr_stripes
) {
4632 if (drop_one_stripe(conf
))
4633 conf
->max_nr_stripes
--;
4637 err
= md_allow_write(mddev
);
4640 while (size
> conf
->max_nr_stripes
) {
4641 if (grow_one_stripe(conf
))
4642 conf
->max_nr_stripes
++;
4647 EXPORT_SYMBOL(raid5_set_cache_size
);
4650 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4652 struct r5conf
*conf
= mddev
->private;
4656 if (len
>= PAGE_SIZE
)
4661 if (strict_strtoul(page
, 10, &new))
4663 err
= raid5_set_cache_size(mddev
, new);
4669 static struct md_sysfs_entry
4670 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4671 raid5_show_stripe_cache_size
,
4672 raid5_store_stripe_cache_size
);
4675 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4677 struct r5conf
*conf
= mddev
->private;
4679 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4685 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4687 struct r5conf
*conf
= mddev
->private;
4689 if (len
>= PAGE_SIZE
)
4694 if (strict_strtoul(page
, 10, &new))
4696 if (new > conf
->max_nr_stripes
)
4698 conf
->bypass_threshold
= new;
4702 static struct md_sysfs_entry
4703 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4705 raid5_show_preread_threshold
,
4706 raid5_store_preread_threshold
);
4709 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4711 struct r5conf
*conf
= mddev
->private;
4713 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4718 static struct md_sysfs_entry
4719 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4721 static struct attribute
*raid5_attrs
[] = {
4722 &raid5_stripecache_size
.attr
,
4723 &raid5_stripecache_active
.attr
,
4724 &raid5_preread_bypass_threshold
.attr
,
4727 static struct attribute_group raid5_attrs_group
= {
4729 .attrs
= raid5_attrs
,
4733 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4735 struct r5conf
*conf
= mddev
->private;
4738 sectors
= mddev
->dev_sectors
;
4740 /* size is defined by the smallest of previous and new size */
4741 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4743 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4744 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4745 return sectors
* (raid_disks
- conf
->max_degraded
);
4748 static void raid5_free_percpu(struct r5conf
*conf
)
4750 struct raid5_percpu
*percpu
;
4757 for_each_possible_cpu(cpu
) {
4758 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4759 safe_put_page(percpu
->spare_page
);
4760 kfree(percpu
->scribble
);
4762 #ifdef CONFIG_HOTPLUG_CPU
4763 unregister_cpu_notifier(&conf
->cpu_notify
);
4767 free_percpu(conf
->percpu
);
4770 static void free_conf(struct r5conf
*conf
)
4772 shrink_stripes(conf
);
4773 raid5_free_percpu(conf
);
4775 kfree(conf
->stripe_hashtbl
);
4779 #ifdef CONFIG_HOTPLUG_CPU
4780 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4783 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
4784 long cpu
= (long)hcpu
;
4785 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4788 case CPU_UP_PREPARE
:
4789 case CPU_UP_PREPARE_FROZEN
:
4790 if (conf
->level
== 6 && !percpu
->spare_page
)
4791 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4792 if (!percpu
->scribble
)
4793 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4795 if (!percpu
->scribble
||
4796 (conf
->level
== 6 && !percpu
->spare_page
)) {
4797 safe_put_page(percpu
->spare_page
);
4798 kfree(percpu
->scribble
);
4799 pr_err("%s: failed memory allocation for cpu%ld\n",
4801 return notifier_from_errno(-ENOMEM
);
4805 case CPU_DEAD_FROZEN
:
4806 safe_put_page(percpu
->spare_page
);
4807 kfree(percpu
->scribble
);
4808 percpu
->spare_page
= NULL
;
4809 percpu
->scribble
= NULL
;
4818 static int raid5_alloc_percpu(struct r5conf
*conf
)
4821 struct page
*spare_page
;
4822 struct raid5_percpu __percpu
*allcpus
;
4826 allcpus
= alloc_percpu(struct raid5_percpu
);
4829 conf
->percpu
= allcpus
;
4833 for_each_present_cpu(cpu
) {
4834 if (conf
->level
== 6) {
4835 spare_page
= alloc_page(GFP_KERNEL
);
4840 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4842 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4847 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4849 #ifdef CONFIG_HOTPLUG_CPU
4850 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4851 conf
->cpu_notify
.priority
= 0;
4853 err
= register_cpu_notifier(&conf
->cpu_notify
);
4860 static struct r5conf
*setup_conf(struct mddev
*mddev
)
4862 struct r5conf
*conf
;
4863 int raid_disk
, memory
, max_disks
;
4864 struct md_rdev
*rdev
;
4865 struct disk_info
*disk
;
4868 if (mddev
->new_level
!= 5
4869 && mddev
->new_level
!= 4
4870 && mddev
->new_level
!= 6) {
4871 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4872 mdname(mddev
), mddev
->new_level
);
4873 return ERR_PTR(-EIO
);
4875 if ((mddev
->new_level
== 5
4876 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4877 (mddev
->new_level
== 6
4878 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4879 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4880 mdname(mddev
), mddev
->new_layout
);
4881 return ERR_PTR(-EIO
);
4883 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4884 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4885 mdname(mddev
), mddev
->raid_disks
);
4886 return ERR_PTR(-EINVAL
);
4889 if (!mddev
->new_chunk_sectors
||
4890 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4891 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4892 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4893 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4894 return ERR_PTR(-EINVAL
);
4897 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
4900 spin_lock_init(&conf
->device_lock
);
4901 init_waitqueue_head(&conf
->wait_for_stripe
);
4902 init_waitqueue_head(&conf
->wait_for_overlap
);
4903 INIT_LIST_HEAD(&conf
->handle_list
);
4904 INIT_LIST_HEAD(&conf
->hold_list
);
4905 INIT_LIST_HEAD(&conf
->delayed_list
);
4906 INIT_LIST_HEAD(&conf
->bitmap_list
);
4907 INIT_LIST_HEAD(&conf
->inactive_list
);
4908 atomic_set(&conf
->active_stripes
, 0);
4909 atomic_set(&conf
->preread_active_stripes
, 0);
4910 atomic_set(&conf
->active_aligned_reads
, 0);
4911 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4912 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
4914 conf
->raid_disks
= mddev
->raid_disks
;
4915 if (mddev
->reshape_position
== MaxSector
)
4916 conf
->previous_raid_disks
= mddev
->raid_disks
;
4918 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4919 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4920 conf
->scribble_len
= scribble_len(max_disks
);
4922 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4927 conf
->mddev
= mddev
;
4929 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4932 conf
->level
= mddev
->new_level
;
4933 if (raid5_alloc_percpu(conf
) != 0)
4936 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4938 rdev_for_each(rdev
, mddev
) {
4939 raid_disk
= rdev
->raid_disk
;
4940 if (raid_disk
>= max_disks
4943 disk
= conf
->disks
+ raid_disk
;
4945 if (test_bit(Replacement
, &rdev
->flags
)) {
4946 if (disk
->replacement
)
4948 disk
->replacement
= rdev
;
4955 if (test_bit(In_sync
, &rdev
->flags
)) {
4956 char b
[BDEVNAME_SIZE
];
4957 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4959 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4960 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4961 /* Cannot rely on bitmap to complete recovery */
4965 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4966 conf
->level
= mddev
->new_level
;
4967 if (conf
->level
== 6)
4968 conf
->max_degraded
= 2;
4970 conf
->max_degraded
= 1;
4971 conf
->algorithm
= mddev
->new_layout
;
4972 conf
->max_nr_stripes
= NR_STRIPES
;
4973 conf
->reshape_progress
= mddev
->reshape_position
;
4974 if (conf
->reshape_progress
!= MaxSector
) {
4975 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4976 conf
->prev_algo
= mddev
->layout
;
4979 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4980 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4981 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4983 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4984 mdname(mddev
), memory
);
4987 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4988 mdname(mddev
), memory
);
4990 sprintf(pers_name
, "raid%d", mddev
->new_level
);
4991 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
4992 if (!conf
->thread
) {
4994 "md/raid:%s: couldn't allocate thread.\n",
5004 return ERR_PTR(-EIO
);
5006 return ERR_PTR(-ENOMEM
);
5010 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5013 case ALGORITHM_PARITY_0
:
5014 if (raid_disk
< max_degraded
)
5017 case ALGORITHM_PARITY_N
:
5018 if (raid_disk
>= raid_disks
- max_degraded
)
5021 case ALGORITHM_PARITY_0_6
:
5022 if (raid_disk
== 0 ||
5023 raid_disk
== raid_disks
- 1)
5026 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5027 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5028 case ALGORITHM_LEFT_SYMMETRIC_6
:
5029 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5030 if (raid_disk
== raid_disks
- 1)
5036 static int run(struct mddev
*mddev
)
5038 struct r5conf
*conf
;
5039 int working_disks
= 0;
5040 int dirty_parity_disks
= 0;
5041 struct md_rdev
*rdev
;
5042 sector_t reshape_offset
= 0;
5044 long long min_offset_diff
= 0;
5047 if (mddev
->recovery_cp
!= MaxSector
)
5048 printk(KERN_NOTICE
"md/raid:%s: not clean"
5049 " -- starting background reconstruction\n",
5052 rdev_for_each(rdev
, mddev
) {
5054 if (rdev
->raid_disk
< 0)
5056 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5058 min_offset_diff
= diff
;
5060 } else if (mddev
->reshape_backwards
&&
5061 diff
< min_offset_diff
)
5062 min_offset_diff
= diff
;
5063 else if (!mddev
->reshape_backwards
&&
5064 diff
> min_offset_diff
)
5065 min_offset_diff
= diff
;
5068 if (mddev
->reshape_position
!= MaxSector
) {
5069 /* Check that we can continue the reshape.
5070 * Difficulties arise if the stripe we would write to
5071 * next is at or after the stripe we would read from next.
5072 * For a reshape that changes the number of devices, this
5073 * is only possible for a very short time, and mdadm makes
5074 * sure that time appears to have past before assembling
5075 * the array. So we fail if that time hasn't passed.
5076 * For a reshape that keeps the number of devices the same
5077 * mdadm must be monitoring the reshape can keeping the
5078 * critical areas read-only and backed up. It will start
5079 * the array in read-only mode, so we check for that.
5081 sector_t here_new
, here_old
;
5083 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5085 if (mddev
->new_level
!= mddev
->level
) {
5086 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5087 "required - aborting.\n",
5091 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5092 /* reshape_position must be on a new-stripe boundary, and one
5093 * further up in new geometry must map after here in old
5096 here_new
= mddev
->reshape_position
;
5097 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5098 (mddev
->raid_disks
- max_degraded
))) {
5099 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5100 "on a stripe boundary\n", mdname(mddev
));
5103 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5104 /* here_new is the stripe we will write to */
5105 here_old
= mddev
->reshape_position
;
5106 sector_div(here_old
, mddev
->chunk_sectors
*
5107 (old_disks
-max_degraded
));
5108 /* here_old is the first stripe that we might need to read
5110 if (mddev
->delta_disks
== 0) {
5111 if ((here_new
* mddev
->new_chunk_sectors
!=
5112 here_old
* mddev
->chunk_sectors
)) {
5113 printk(KERN_ERR
"md/raid:%s: reshape position is"
5114 " confused - aborting\n", mdname(mddev
));
5117 /* We cannot be sure it is safe to start an in-place
5118 * reshape. It is only safe if user-space is monitoring
5119 * and taking constant backups.
5120 * mdadm always starts a situation like this in
5121 * readonly mode so it can take control before
5122 * allowing any writes. So just check for that.
5124 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5125 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5126 /* not really in-place - so OK */;
5127 else if (mddev
->ro
== 0) {
5128 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5129 "must be started in read-only mode "
5134 } else if (mddev
->reshape_backwards
5135 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5136 here_old
* mddev
->chunk_sectors
)
5137 : (here_new
* mddev
->new_chunk_sectors
>=
5138 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5139 /* Reading from the same stripe as writing to - bad */
5140 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5141 "auto-recovery - aborting.\n",
5145 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5147 /* OK, we should be able to continue; */
5149 BUG_ON(mddev
->level
!= mddev
->new_level
);
5150 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5151 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5152 BUG_ON(mddev
->delta_disks
!= 0);
5155 if (mddev
->private == NULL
)
5156 conf
= setup_conf(mddev
);
5158 conf
= mddev
->private;
5161 return PTR_ERR(conf
);
5163 conf
->min_offset_diff
= min_offset_diff
;
5164 mddev
->thread
= conf
->thread
;
5165 conf
->thread
= NULL
;
5166 mddev
->private = conf
;
5168 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5170 rdev
= conf
->disks
[i
].rdev
;
5171 if (!rdev
&& conf
->disks
[i
].replacement
) {
5172 /* The replacement is all we have yet */
5173 rdev
= conf
->disks
[i
].replacement
;
5174 conf
->disks
[i
].replacement
= NULL
;
5175 clear_bit(Replacement
, &rdev
->flags
);
5176 conf
->disks
[i
].rdev
= rdev
;
5180 if (conf
->disks
[i
].replacement
&&
5181 conf
->reshape_progress
!= MaxSector
) {
5182 /* replacements and reshape simply do not mix. */
5183 printk(KERN_ERR
"md: cannot handle concurrent "
5184 "replacement and reshape.\n");
5187 if (test_bit(In_sync
, &rdev
->flags
)) {
5191 /* This disc is not fully in-sync. However if it
5192 * just stored parity (beyond the recovery_offset),
5193 * when we don't need to be concerned about the
5194 * array being dirty.
5195 * When reshape goes 'backwards', we never have
5196 * partially completed devices, so we only need
5197 * to worry about reshape going forwards.
5199 /* Hack because v0.91 doesn't store recovery_offset properly. */
5200 if (mddev
->major_version
== 0 &&
5201 mddev
->minor_version
> 90)
5202 rdev
->recovery_offset
= reshape_offset
;
5204 if (rdev
->recovery_offset
< reshape_offset
) {
5205 /* We need to check old and new layout */
5206 if (!only_parity(rdev
->raid_disk
,
5209 conf
->max_degraded
))
5212 if (!only_parity(rdev
->raid_disk
,
5214 conf
->previous_raid_disks
,
5215 conf
->max_degraded
))
5217 dirty_parity_disks
++;
5221 * 0 for a fully functional array, 1 or 2 for a degraded array.
5223 mddev
->degraded
= calc_degraded(conf
);
5225 if (has_failed(conf
)) {
5226 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5227 " (%d/%d failed)\n",
5228 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5232 /* device size must be a multiple of chunk size */
5233 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5234 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5236 if (mddev
->degraded
> dirty_parity_disks
&&
5237 mddev
->recovery_cp
!= MaxSector
) {
5238 if (mddev
->ok_start_degraded
)
5240 "md/raid:%s: starting dirty degraded array"
5241 " - data corruption possible.\n",
5245 "md/raid:%s: cannot start dirty degraded array.\n",
5251 if (mddev
->degraded
== 0)
5252 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5253 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5254 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5257 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5258 " out of %d devices, algorithm %d\n",
5259 mdname(mddev
), conf
->level
,
5260 mddev
->raid_disks
- mddev
->degraded
,
5261 mddev
->raid_disks
, mddev
->new_layout
);
5263 print_raid5_conf(conf
);
5265 if (conf
->reshape_progress
!= MaxSector
) {
5266 conf
->reshape_safe
= conf
->reshape_progress
;
5267 atomic_set(&conf
->reshape_stripes
, 0);
5268 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5269 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5270 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5271 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5272 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5277 /* Ok, everything is just fine now */
5278 if (mddev
->to_remove
== &raid5_attrs_group
)
5279 mddev
->to_remove
= NULL
;
5280 else if (mddev
->kobj
.sd
&&
5281 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5283 "raid5: failed to create sysfs attributes for %s\n",
5285 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5289 /* read-ahead size must cover two whole stripes, which
5290 * is 2 * (datadisks) * chunksize where 'n' is the
5291 * number of raid devices
5293 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5294 int stripe
= data_disks
*
5295 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5296 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5297 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5299 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5301 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5302 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5304 chunk_size
= mddev
->chunk_sectors
<< 9;
5305 blk_queue_io_min(mddev
->queue
, chunk_size
);
5306 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5307 (conf
->raid_disks
- conf
->max_degraded
));
5309 rdev_for_each(rdev
, mddev
) {
5310 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5311 rdev
->data_offset
<< 9);
5312 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5313 rdev
->new_data_offset
<< 9);
5319 md_unregister_thread(&mddev
->thread
);
5320 print_raid5_conf(conf
);
5322 mddev
->private = NULL
;
5323 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5327 static int stop(struct mddev
*mddev
)
5329 struct r5conf
*conf
= mddev
->private;
5331 md_unregister_thread(&mddev
->thread
);
5333 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5335 mddev
->private = NULL
;
5336 mddev
->to_remove
= &raid5_attrs_group
;
5340 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5342 struct r5conf
*conf
= mddev
->private;
5345 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5346 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5347 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5348 for (i
= 0; i
< conf
->raid_disks
; i
++)
5349 seq_printf (seq
, "%s",
5350 conf
->disks
[i
].rdev
&&
5351 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5352 seq_printf (seq
, "]");
5355 static void print_raid5_conf (struct r5conf
*conf
)
5358 struct disk_info
*tmp
;
5360 printk(KERN_DEBUG
"RAID conf printout:\n");
5362 printk("(conf==NULL)\n");
5365 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5367 conf
->raid_disks
- conf
->mddev
->degraded
);
5369 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5370 char b
[BDEVNAME_SIZE
];
5371 tmp
= conf
->disks
+ i
;
5373 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5374 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5375 bdevname(tmp
->rdev
->bdev
, b
));
5379 static int raid5_spare_active(struct mddev
*mddev
)
5382 struct r5conf
*conf
= mddev
->private;
5383 struct disk_info
*tmp
;
5385 unsigned long flags
;
5387 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5388 tmp
= conf
->disks
+ i
;
5389 if (tmp
->replacement
5390 && tmp
->replacement
->recovery_offset
== MaxSector
5391 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5392 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5393 /* Replacement has just become active. */
5395 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5398 /* Replaced device not technically faulty,
5399 * but we need to be sure it gets removed
5400 * and never re-added.
5402 set_bit(Faulty
, &tmp
->rdev
->flags
);
5403 sysfs_notify_dirent_safe(
5404 tmp
->rdev
->sysfs_state
);
5406 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5407 } else if (tmp
->rdev
5408 && tmp
->rdev
->recovery_offset
== MaxSector
5409 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5410 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5412 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5415 spin_lock_irqsave(&conf
->device_lock
, flags
);
5416 mddev
->degraded
= calc_degraded(conf
);
5417 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5418 print_raid5_conf(conf
);
5422 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5424 struct r5conf
*conf
= mddev
->private;
5426 int number
= rdev
->raid_disk
;
5427 struct md_rdev
**rdevp
;
5428 struct disk_info
*p
= conf
->disks
+ number
;
5430 print_raid5_conf(conf
);
5431 if (rdev
== p
->rdev
)
5433 else if (rdev
== p
->replacement
)
5434 rdevp
= &p
->replacement
;
5438 if (number
>= conf
->raid_disks
&&
5439 conf
->reshape_progress
== MaxSector
)
5440 clear_bit(In_sync
, &rdev
->flags
);
5442 if (test_bit(In_sync
, &rdev
->flags
) ||
5443 atomic_read(&rdev
->nr_pending
)) {
5447 /* Only remove non-faulty devices if recovery
5450 if (!test_bit(Faulty
, &rdev
->flags
) &&
5451 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5452 !has_failed(conf
) &&
5453 (!p
->replacement
|| p
->replacement
== rdev
) &&
5454 number
< conf
->raid_disks
) {
5460 if (atomic_read(&rdev
->nr_pending
)) {
5461 /* lost the race, try later */
5464 } else if (p
->replacement
) {
5465 /* We must have just cleared 'rdev' */
5466 p
->rdev
= p
->replacement
;
5467 clear_bit(Replacement
, &p
->replacement
->flags
);
5468 smp_mb(); /* Make sure other CPUs may see both as identical
5469 * but will never see neither - if they are careful
5471 p
->replacement
= NULL
;
5472 clear_bit(WantReplacement
, &rdev
->flags
);
5474 /* We might have just removed the Replacement as faulty-
5475 * clear the bit just in case
5477 clear_bit(WantReplacement
, &rdev
->flags
);
5480 print_raid5_conf(conf
);
5484 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5486 struct r5conf
*conf
= mddev
->private;
5489 struct disk_info
*p
;
5491 int last
= conf
->raid_disks
- 1;
5493 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5496 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5497 /* no point adding a device */
5500 if (rdev
->raid_disk
>= 0)
5501 first
= last
= rdev
->raid_disk
;
5504 * find the disk ... but prefer rdev->saved_raid_disk
5507 if (rdev
->saved_raid_disk
>= 0 &&
5508 rdev
->saved_raid_disk
>= first
&&
5509 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5510 first
= rdev
->saved_raid_disk
;
5512 for (disk
= first
; disk
<= last
; disk
++) {
5513 p
= conf
->disks
+ disk
;
5514 if (p
->rdev
== NULL
) {
5515 clear_bit(In_sync
, &rdev
->flags
);
5516 rdev
->raid_disk
= disk
;
5518 if (rdev
->saved_raid_disk
!= disk
)
5520 rcu_assign_pointer(p
->rdev
, rdev
);
5524 for (disk
= first
; disk
<= last
; disk
++) {
5525 p
= conf
->disks
+ disk
;
5526 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5527 p
->replacement
== NULL
) {
5528 clear_bit(In_sync
, &rdev
->flags
);
5529 set_bit(Replacement
, &rdev
->flags
);
5530 rdev
->raid_disk
= disk
;
5533 rcu_assign_pointer(p
->replacement
, rdev
);
5538 print_raid5_conf(conf
);
5542 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5544 /* no resync is happening, and there is enough space
5545 * on all devices, so we can resize.
5546 * We need to make sure resync covers any new space.
5547 * If the array is shrinking we should possibly wait until
5548 * any io in the removed space completes, but it hardly seems
5552 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5553 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5554 if (mddev
->external_size
&&
5555 mddev
->array_sectors
> newsize
)
5557 if (mddev
->bitmap
) {
5558 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5562 md_set_array_sectors(mddev
, newsize
);
5563 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5564 revalidate_disk(mddev
->gendisk
);
5565 if (sectors
> mddev
->dev_sectors
&&
5566 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5567 mddev
->recovery_cp
= mddev
->dev_sectors
;
5568 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5570 mddev
->dev_sectors
= sectors
;
5571 mddev
->resync_max_sectors
= sectors
;
5575 static int check_stripe_cache(struct mddev
*mddev
)
5577 /* Can only proceed if there are plenty of stripe_heads.
5578 * We need a minimum of one full stripe,, and for sensible progress
5579 * it is best to have about 4 times that.
5580 * If we require 4 times, then the default 256 4K stripe_heads will
5581 * allow for chunk sizes up to 256K, which is probably OK.
5582 * If the chunk size is greater, user-space should request more
5583 * stripe_heads first.
5585 struct r5conf
*conf
= mddev
->private;
5586 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5587 > conf
->max_nr_stripes
||
5588 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5589 > conf
->max_nr_stripes
) {
5590 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5592 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5599 static int check_reshape(struct mddev
*mddev
)
5601 struct r5conf
*conf
= mddev
->private;
5603 if (mddev
->delta_disks
== 0 &&
5604 mddev
->new_layout
== mddev
->layout
&&
5605 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5606 return 0; /* nothing to do */
5607 if (has_failed(conf
))
5609 if (mddev
->delta_disks
< 0) {
5610 /* We might be able to shrink, but the devices must
5611 * be made bigger first.
5612 * For raid6, 4 is the minimum size.
5613 * Otherwise 2 is the minimum
5616 if (mddev
->level
== 6)
5618 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5622 if (!check_stripe_cache(mddev
))
5625 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5628 static int raid5_start_reshape(struct mddev
*mddev
)
5630 struct r5conf
*conf
= mddev
->private;
5631 struct md_rdev
*rdev
;
5633 unsigned long flags
;
5635 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5638 if (!check_stripe_cache(mddev
))
5641 if (has_failed(conf
))
5644 rdev_for_each(rdev
, mddev
) {
5645 if (!test_bit(In_sync
, &rdev
->flags
)
5646 && !test_bit(Faulty
, &rdev
->flags
))
5650 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5651 /* Not enough devices even to make a degraded array
5656 /* Refuse to reduce size of the array. Any reductions in
5657 * array size must be through explicit setting of array_size
5660 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5661 < mddev
->array_sectors
) {
5662 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5663 "before number of disks\n", mdname(mddev
));
5667 atomic_set(&conf
->reshape_stripes
, 0);
5668 spin_lock_irq(&conf
->device_lock
);
5669 conf
->previous_raid_disks
= conf
->raid_disks
;
5670 conf
->raid_disks
+= mddev
->delta_disks
;
5671 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5672 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5673 conf
->prev_algo
= conf
->algorithm
;
5674 conf
->algorithm
= mddev
->new_layout
;
5676 /* Code that selects data_offset needs to see the generation update
5677 * if reshape_progress has been set - so a memory barrier needed.
5680 if (mddev
->reshape_backwards
)
5681 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5683 conf
->reshape_progress
= 0;
5684 conf
->reshape_safe
= conf
->reshape_progress
;
5685 spin_unlock_irq(&conf
->device_lock
);
5687 /* Add some new drives, as many as will fit.
5688 * We know there are enough to make the newly sized array work.
5689 * Don't add devices if we are reducing the number of
5690 * devices in the array. This is because it is not possible
5691 * to correctly record the "partially reconstructed" state of
5692 * such devices during the reshape and confusion could result.
5694 if (mddev
->delta_disks
>= 0) {
5695 rdev_for_each(rdev
, mddev
)
5696 if (rdev
->raid_disk
< 0 &&
5697 !test_bit(Faulty
, &rdev
->flags
)) {
5698 if (raid5_add_disk(mddev
, rdev
) == 0) {
5700 >= conf
->previous_raid_disks
)
5701 set_bit(In_sync
, &rdev
->flags
);
5703 rdev
->recovery_offset
= 0;
5705 if (sysfs_link_rdev(mddev
, rdev
))
5706 /* Failure here is OK */;
5708 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5709 && !test_bit(Faulty
, &rdev
->flags
)) {
5710 /* This is a spare that was manually added */
5711 set_bit(In_sync
, &rdev
->flags
);
5714 /* When a reshape changes the number of devices,
5715 * ->degraded is measured against the larger of the
5716 * pre and post number of devices.
5718 spin_lock_irqsave(&conf
->device_lock
, flags
);
5719 mddev
->degraded
= calc_degraded(conf
);
5720 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5722 mddev
->raid_disks
= conf
->raid_disks
;
5723 mddev
->reshape_position
= conf
->reshape_progress
;
5724 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5726 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5727 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5728 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5729 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5730 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5732 if (!mddev
->sync_thread
) {
5733 mddev
->recovery
= 0;
5734 spin_lock_irq(&conf
->device_lock
);
5735 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5736 rdev_for_each(rdev
, mddev
)
5737 rdev
->new_data_offset
= rdev
->data_offset
;
5739 conf
->reshape_progress
= MaxSector
;
5740 mddev
->reshape_position
= MaxSector
;
5741 spin_unlock_irq(&conf
->device_lock
);
5744 conf
->reshape_checkpoint
= jiffies
;
5745 md_wakeup_thread(mddev
->sync_thread
);
5746 md_new_event(mddev
);
5750 /* This is called from the reshape thread and should make any
5751 * changes needed in 'conf'
5753 static void end_reshape(struct r5conf
*conf
)
5756 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5757 struct md_rdev
*rdev
;
5759 spin_lock_irq(&conf
->device_lock
);
5760 conf
->previous_raid_disks
= conf
->raid_disks
;
5761 rdev_for_each(rdev
, conf
->mddev
)
5762 rdev
->data_offset
= rdev
->new_data_offset
;
5764 conf
->reshape_progress
= MaxSector
;
5765 spin_unlock_irq(&conf
->device_lock
);
5766 wake_up(&conf
->wait_for_overlap
);
5768 /* read-ahead size must cover two whole stripes, which is
5769 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5771 if (conf
->mddev
->queue
) {
5772 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5773 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5775 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5776 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5781 /* This is called from the raid5d thread with mddev_lock held.
5782 * It makes config changes to the device.
5784 static void raid5_finish_reshape(struct mddev
*mddev
)
5786 struct r5conf
*conf
= mddev
->private;
5788 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5790 if (mddev
->delta_disks
> 0) {
5791 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5792 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5793 revalidate_disk(mddev
->gendisk
);
5796 spin_lock_irq(&conf
->device_lock
);
5797 mddev
->degraded
= calc_degraded(conf
);
5798 spin_unlock_irq(&conf
->device_lock
);
5799 for (d
= conf
->raid_disks
;
5800 d
< conf
->raid_disks
- mddev
->delta_disks
;
5802 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
5804 clear_bit(In_sync
, &rdev
->flags
);
5805 rdev
= conf
->disks
[d
].replacement
;
5807 clear_bit(In_sync
, &rdev
->flags
);
5810 mddev
->layout
= conf
->algorithm
;
5811 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5812 mddev
->reshape_position
= MaxSector
;
5813 mddev
->delta_disks
= 0;
5814 mddev
->reshape_backwards
= 0;
5818 static void raid5_quiesce(struct mddev
*mddev
, int state
)
5820 struct r5conf
*conf
= mddev
->private;
5823 case 2: /* resume for a suspend */
5824 wake_up(&conf
->wait_for_overlap
);
5827 case 1: /* stop all writes */
5828 spin_lock_irq(&conf
->device_lock
);
5829 /* '2' tells resync/reshape to pause so that all
5830 * active stripes can drain
5833 wait_event_lock_irq(conf
->wait_for_stripe
,
5834 atomic_read(&conf
->active_stripes
) == 0 &&
5835 atomic_read(&conf
->active_aligned_reads
) == 0,
5836 conf
->device_lock
, /* nothing */);
5838 spin_unlock_irq(&conf
->device_lock
);
5839 /* allow reshape to continue */
5840 wake_up(&conf
->wait_for_overlap
);
5843 case 0: /* re-enable writes */
5844 spin_lock_irq(&conf
->device_lock
);
5846 wake_up(&conf
->wait_for_stripe
);
5847 wake_up(&conf
->wait_for_overlap
);
5848 spin_unlock_irq(&conf
->device_lock
);
5854 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
5856 struct r0conf
*raid0_conf
= mddev
->private;
5859 /* for raid0 takeover only one zone is supported */
5860 if (raid0_conf
->nr_strip_zones
> 1) {
5861 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5863 return ERR_PTR(-EINVAL
);
5866 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
5867 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
5868 mddev
->dev_sectors
= sectors
;
5869 mddev
->new_level
= level
;
5870 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5871 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5872 mddev
->raid_disks
+= 1;
5873 mddev
->delta_disks
= 1;
5874 /* make sure it will be not marked as dirty */
5875 mddev
->recovery_cp
= MaxSector
;
5877 return setup_conf(mddev
);
5881 static void *raid5_takeover_raid1(struct mddev
*mddev
)
5885 if (mddev
->raid_disks
!= 2 ||
5886 mddev
->degraded
> 1)
5887 return ERR_PTR(-EINVAL
);
5889 /* Should check if there are write-behind devices? */
5891 chunksect
= 64*2; /* 64K by default */
5893 /* The array must be an exact multiple of chunksize */
5894 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5897 if ((chunksect
<<9) < STRIPE_SIZE
)
5898 /* array size does not allow a suitable chunk size */
5899 return ERR_PTR(-EINVAL
);
5901 mddev
->new_level
= 5;
5902 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5903 mddev
->new_chunk_sectors
= chunksect
;
5905 return setup_conf(mddev
);
5908 static void *raid5_takeover_raid6(struct mddev
*mddev
)
5912 switch (mddev
->layout
) {
5913 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5914 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5916 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5917 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5919 case ALGORITHM_LEFT_SYMMETRIC_6
:
5920 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5922 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5923 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5925 case ALGORITHM_PARITY_0_6
:
5926 new_layout
= ALGORITHM_PARITY_0
;
5928 case ALGORITHM_PARITY_N
:
5929 new_layout
= ALGORITHM_PARITY_N
;
5932 return ERR_PTR(-EINVAL
);
5934 mddev
->new_level
= 5;
5935 mddev
->new_layout
= new_layout
;
5936 mddev
->delta_disks
= -1;
5937 mddev
->raid_disks
-= 1;
5938 return setup_conf(mddev
);
5942 static int raid5_check_reshape(struct mddev
*mddev
)
5944 /* For a 2-drive array, the layout and chunk size can be changed
5945 * immediately as not restriping is needed.
5946 * For larger arrays we record the new value - after validation
5947 * to be used by a reshape pass.
5949 struct r5conf
*conf
= mddev
->private;
5950 int new_chunk
= mddev
->new_chunk_sectors
;
5952 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5954 if (new_chunk
> 0) {
5955 if (!is_power_of_2(new_chunk
))
5957 if (new_chunk
< (PAGE_SIZE
>>9))
5959 if (mddev
->array_sectors
& (new_chunk
-1))
5960 /* not factor of array size */
5964 /* They look valid */
5966 if (mddev
->raid_disks
== 2) {
5967 /* can make the change immediately */
5968 if (mddev
->new_layout
>= 0) {
5969 conf
->algorithm
= mddev
->new_layout
;
5970 mddev
->layout
= mddev
->new_layout
;
5972 if (new_chunk
> 0) {
5973 conf
->chunk_sectors
= new_chunk
;
5974 mddev
->chunk_sectors
= new_chunk
;
5976 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5977 md_wakeup_thread(mddev
->thread
);
5979 return check_reshape(mddev
);
5982 static int raid6_check_reshape(struct mddev
*mddev
)
5984 int new_chunk
= mddev
->new_chunk_sectors
;
5986 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5988 if (new_chunk
> 0) {
5989 if (!is_power_of_2(new_chunk
))
5991 if (new_chunk
< (PAGE_SIZE
>> 9))
5993 if (mddev
->array_sectors
& (new_chunk
-1))
5994 /* not factor of array size */
5998 /* They look valid */
5999 return check_reshape(mddev
);
6002 static void *raid5_takeover(struct mddev
*mddev
)
6004 /* raid5 can take over:
6005 * raid0 - if there is only one strip zone - make it a raid4 layout
6006 * raid1 - if there are two drives. We need to know the chunk size
6007 * raid4 - trivial - just use a raid4 layout.
6008 * raid6 - Providing it is a *_6 layout
6010 if (mddev
->level
== 0)
6011 return raid45_takeover_raid0(mddev
, 5);
6012 if (mddev
->level
== 1)
6013 return raid5_takeover_raid1(mddev
);
6014 if (mddev
->level
== 4) {
6015 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6016 mddev
->new_level
= 5;
6017 return setup_conf(mddev
);
6019 if (mddev
->level
== 6)
6020 return raid5_takeover_raid6(mddev
);
6022 return ERR_PTR(-EINVAL
);
6025 static void *raid4_takeover(struct mddev
*mddev
)
6027 /* raid4 can take over:
6028 * raid0 - if there is only one strip zone
6029 * raid5 - if layout is right
6031 if (mddev
->level
== 0)
6032 return raid45_takeover_raid0(mddev
, 4);
6033 if (mddev
->level
== 5 &&
6034 mddev
->layout
== ALGORITHM_PARITY_N
) {
6035 mddev
->new_layout
= 0;
6036 mddev
->new_level
= 4;
6037 return setup_conf(mddev
);
6039 return ERR_PTR(-EINVAL
);
6042 static struct md_personality raid5_personality
;
6044 static void *raid6_takeover(struct mddev
*mddev
)
6046 /* Currently can only take over a raid5. We map the
6047 * personality to an equivalent raid6 personality
6048 * with the Q block at the end.
6052 if (mddev
->pers
!= &raid5_personality
)
6053 return ERR_PTR(-EINVAL
);
6054 if (mddev
->degraded
> 1)
6055 return ERR_PTR(-EINVAL
);
6056 if (mddev
->raid_disks
> 253)
6057 return ERR_PTR(-EINVAL
);
6058 if (mddev
->raid_disks
< 3)
6059 return ERR_PTR(-EINVAL
);
6061 switch (mddev
->layout
) {
6062 case ALGORITHM_LEFT_ASYMMETRIC
:
6063 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6065 case ALGORITHM_RIGHT_ASYMMETRIC
:
6066 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6068 case ALGORITHM_LEFT_SYMMETRIC
:
6069 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6071 case ALGORITHM_RIGHT_SYMMETRIC
:
6072 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6074 case ALGORITHM_PARITY_0
:
6075 new_layout
= ALGORITHM_PARITY_0_6
;
6077 case ALGORITHM_PARITY_N
:
6078 new_layout
= ALGORITHM_PARITY_N
;
6081 return ERR_PTR(-EINVAL
);
6083 mddev
->new_level
= 6;
6084 mddev
->new_layout
= new_layout
;
6085 mddev
->delta_disks
= 1;
6086 mddev
->raid_disks
+= 1;
6087 return setup_conf(mddev
);
6091 static struct md_personality raid6_personality
=
6095 .owner
= THIS_MODULE
,
6096 .make_request
= make_request
,
6100 .error_handler
= error
,
6101 .hot_add_disk
= raid5_add_disk
,
6102 .hot_remove_disk
= raid5_remove_disk
,
6103 .spare_active
= raid5_spare_active
,
6104 .sync_request
= sync_request
,
6105 .resize
= raid5_resize
,
6107 .check_reshape
= raid6_check_reshape
,
6108 .start_reshape
= raid5_start_reshape
,
6109 .finish_reshape
= raid5_finish_reshape
,
6110 .quiesce
= raid5_quiesce
,
6111 .takeover
= raid6_takeover
,
6113 static struct md_personality raid5_personality
=
6117 .owner
= THIS_MODULE
,
6118 .make_request
= make_request
,
6122 .error_handler
= error
,
6123 .hot_add_disk
= raid5_add_disk
,
6124 .hot_remove_disk
= raid5_remove_disk
,
6125 .spare_active
= raid5_spare_active
,
6126 .sync_request
= sync_request
,
6127 .resize
= raid5_resize
,
6129 .check_reshape
= raid5_check_reshape
,
6130 .start_reshape
= raid5_start_reshape
,
6131 .finish_reshape
= raid5_finish_reshape
,
6132 .quiesce
= raid5_quiesce
,
6133 .takeover
= raid5_takeover
,
6136 static struct md_personality raid4_personality
=
6140 .owner
= THIS_MODULE
,
6141 .make_request
= make_request
,
6145 .error_handler
= error
,
6146 .hot_add_disk
= raid5_add_disk
,
6147 .hot_remove_disk
= raid5_remove_disk
,
6148 .spare_active
= raid5_spare_active
,
6149 .sync_request
= sync_request
,
6150 .resize
= raid5_resize
,
6152 .check_reshape
= raid5_check_reshape
,
6153 .start_reshape
= raid5_start_reshape
,
6154 .finish_reshape
= raid5_finish_reshape
,
6155 .quiesce
= raid5_quiesce
,
6156 .takeover
= raid4_takeover
,
6159 static int __init
raid5_init(void)
6161 register_md_personality(&raid6_personality
);
6162 register_md_personality(&raid5_personality
);
6163 register_md_personality(&raid4_personality
);
6167 static void raid5_exit(void)
6169 unregister_md_personality(&raid6_personality
);
6170 unregister_md_personality(&raid5_personality
);
6171 unregister_md_personality(&raid4_personality
);
6174 module_init(raid5_init
);
6175 module_exit(raid5_exit
);
6176 MODULE_LICENSE("GPL");
6177 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6178 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6179 MODULE_ALIAS("md-raid5");
6180 MODULE_ALIAS("md-raid4");
6181 MODULE_ALIAS("md-level-5");
6182 MODULE_ALIAS("md-level-4");
6183 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6184 MODULE_ALIAS("md-raid6");
6185 MODULE_ALIAS("md-level-6");
6187 /* This used to be two separate modules, they were: */
6188 MODULE_ALIAS("raid5");
6189 MODULE_ALIAS("raid6");