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>
56 #include <trace/events/block.h>
67 #define NR_STRIPES 256
68 #define STRIPE_SIZE PAGE_SIZE
69 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
70 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
71 #define IO_THRESHOLD 1
72 #define BYPASS_THRESHOLD 1
73 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
74 #define HASH_MASK (NR_HASH - 1)
76 static inline struct hlist_head
*stripe_hash(struct r5conf
*conf
, sector_t sect
)
78 int hash
= (sect
>> STRIPE_SHIFT
) & HASH_MASK
;
79 return &conf
->stripe_hashtbl
[hash
];
82 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
83 * order without overlap. There may be several bio's per stripe+device, and
84 * a bio could span several devices.
85 * When walking this list for a particular stripe+device, we must never proceed
86 * beyond a bio that extends past this device, as the next bio might no longer
88 * This function is used to determine the 'next' bio in the list, given the sector
89 * of the current stripe+device
91 static inline struct bio
*r5_next_bio(struct bio
*bio
, sector_t sector
)
93 int sectors
= bio
->bi_size
>> 9;
94 if (bio
->bi_sector
+ sectors
< sector
+ STRIPE_SECTORS
)
101 * We maintain a biased count of active stripes in the bottom 16 bits of
102 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
104 static inline int raid5_bi_processed_stripes(struct bio
*bio
)
106 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
107 return (atomic_read(segments
) >> 16) & 0xffff;
110 static inline int raid5_dec_bi_active_stripes(struct bio
*bio
)
112 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
113 return atomic_sub_return(1, segments
) & 0xffff;
116 static inline void raid5_inc_bi_active_stripes(struct bio
*bio
)
118 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
119 atomic_inc(segments
);
122 static inline void raid5_set_bi_processed_stripes(struct bio
*bio
,
125 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
129 old
= atomic_read(segments
);
130 new = (old
& 0xffff) | (cnt
<< 16);
131 } while (atomic_cmpxchg(segments
, old
, new) != old
);
134 static inline void raid5_set_bi_stripes(struct bio
*bio
, unsigned int cnt
)
136 atomic_t
*segments
= (atomic_t
*)&bio
->bi_phys_segments
;
137 atomic_set(segments
, cnt
);
140 /* Find first data disk in a raid6 stripe */
141 static inline int raid6_d0(struct stripe_head
*sh
)
144 /* ddf always start from first device */
146 /* md starts just after Q block */
147 if (sh
->qd_idx
== sh
->disks
- 1)
150 return sh
->qd_idx
+ 1;
152 static inline int raid6_next_disk(int disk
, int raid_disks
)
155 return (disk
< raid_disks
) ? disk
: 0;
158 /* When walking through the disks in a raid5, starting at raid6_d0,
159 * We need to map each disk to a 'slot', where the data disks are slot
160 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
161 * is raid_disks-1. This help does that mapping.
163 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
164 int *count
, int syndrome_disks
)
170 if (idx
== sh
->pd_idx
)
171 return syndrome_disks
;
172 if (idx
== sh
->qd_idx
)
173 return syndrome_disks
+ 1;
179 static void return_io(struct bio
*return_bi
)
181 struct bio
*bi
= return_bi
;
184 return_bi
= bi
->bi_next
;
187 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
194 static void print_raid5_conf (struct r5conf
*conf
);
196 static int stripe_operations_active(struct stripe_head
*sh
)
198 return sh
->check_state
|| sh
->reconstruct_state
||
199 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
200 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
203 static void do_release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
205 BUG_ON(!list_empty(&sh
->lru
));
206 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
207 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
208 if (test_bit(STRIPE_DELAYED
, &sh
->state
) &&
209 !test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
210 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
211 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
212 sh
->bm_seq
- conf
->seq_write
> 0)
213 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
215 clear_bit(STRIPE_DELAYED
, &sh
->state
);
216 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
217 list_add_tail(&sh
->lru
, &conf
->handle_list
);
219 md_wakeup_thread(conf
->mddev
->thread
);
221 BUG_ON(stripe_operations_active(sh
));
222 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
223 if (atomic_dec_return(&conf
->preread_active_stripes
)
225 md_wakeup_thread(conf
->mddev
->thread
);
226 atomic_dec(&conf
->active_stripes
);
227 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
228 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
229 wake_up(&conf
->wait_for_stripe
);
230 if (conf
->retry_read_aligned
)
231 md_wakeup_thread(conf
->mddev
->thread
);
236 static void __release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
238 if (atomic_dec_and_test(&sh
->count
))
239 do_release_stripe(conf
, sh
);
242 static void release_stripe(struct stripe_head
*sh
)
244 struct r5conf
*conf
= sh
->raid_conf
;
247 local_irq_save(flags
);
248 if (atomic_dec_and_lock(&sh
->count
, &conf
->device_lock
)) {
249 do_release_stripe(conf
, sh
);
250 spin_unlock(&conf
->device_lock
);
252 local_irq_restore(flags
);
255 static inline void remove_hash(struct stripe_head
*sh
)
257 pr_debug("remove_hash(), stripe %llu\n",
258 (unsigned long long)sh
->sector
);
260 hlist_del_init(&sh
->hash
);
263 static inline void insert_hash(struct r5conf
*conf
, struct stripe_head
*sh
)
265 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
267 pr_debug("insert_hash(), stripe %llu\n",
268 (unsigned long long)sh
->sector
);
270 hlist_add_head(&sh
->hash
, hp
);
274 /* find an idle stripe, make sure it is unhashed, and return it. */
275 static struct stripe_head
*get_free_stripe(struct r5conf
*conf
)
277 struct stripe_head
*sh
= NULL
;
278 struct list_head
*first
;
280 if (list_empty(&conf
->inactive_list
))
282 first
= conf
->inactive_list
.next
;
283 sh
= list_entry(first
, struct stripe_head
, lru
);
284 list_del_init(first
);
286 atomic_inc(&conf
->active_stripes
);
291 static void shrink_buffers(struct stripe_head
*sh
)
295 int num
= sh
->raid_conf
->pool_size
;
297 for (i
= 0; i
< num
; i
++) {
301 sh
->dev
[i
].page
= NULL
;
306 static int grow_buffers(struct stripe_head
*sh
)
309 int num
= sh
->raid_conf
->pool_size
;
311 for (i
= 0; i
< num
; i
++) {
314 if (!(page
= alloc_page(GFP_KERNEL
))) {
317 sh
->dev
[i
].page
= page
;
322 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
);
323 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
324 struct stripe_head
*sh
);
326 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
328 struct r5conf
*conf
= sh
->raid_conf
;
331 BUG_ON(atomic_read(&sh
->count
) != 0);
332 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
333 BUG_ON(stripe_operations_active(sh
));
335 pr_debug("init_stripe called, stripe %llu\n",
336 (unsigned long long)sh
->sector
);
340 sh
->generation
= conf
->generation
- previous
;
341 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
343 stripe_set_idx(sector
, conf
, previous
, sh
);
347 for (i
= sh
->disks
; i
--; ) {
348 struct r5dev
*dev
= &sh
->dev
[i
];
350 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
351 test_bit(R5_LOCKED
, &dev
->flags
)) {
352 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
353 (unsigned long long)sh
->sector
, i
, dev
->toread
,
354 dev
->read
, dev
->towrite
, dev
->written
,
355 test_bit(R5_LOCKED
, &dev
->flags
));
359 raid5_build_block(sh
, i
, previous
);
361 insert_hash(conf
, sh
);
364 static struct stripe_head
*__find_stripe(struct r5conf
*conf
, sector_t sector
,
367 struct stripe_head
*sh
;
369 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
370 hlist_for_each_entry(sh
, stripe_hash(conf
, sector
), hash
)
371 if (sh
->sector
== sector
&& sh
->generation
== generation
)
373 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
378 * Need to check if array has failed when deciding whether to:
380 * - remove non-faulty devices
383 * This determination is simple when no reshape is happening.
384 * However if there is a reshape, we need to carefully check
385 * both the before and after sections.
386 * This is because some failed devices may only affect one
387 * of the two sections, and some non-in_sync devices may
388 * be insync in the section most affected by failed devices.
390 static int calc_degraded(struct r5conf
*conf
)
392 int degraded
, degraded2
;
397 for (i
= 0; i
< conf
->previous_raid_disks
; i
++) {
398 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
399 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
400 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
401 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
403 else if (test_bit(In_sync
, &rdev
->flags
))
406 /* not in-sync or faulty.
407 * If the reshape increases the number of devices,
408 * this is being recovered by the reshape, so
409 * this 'previous' section is not in_sync.
410 * If the number of devices is being reduced however,
411 * the device can only be part of the array if
412 * we are reverting a reshape, so this section will
415 if (conf
->raid_disks
>= conf
->previous_raid_disks
)
419 if (conf
->raid_disks
== conf
->previous_raid_disks
)
423 for (i
= 0; i
< conf
->raid_disks
; i
++) {
424 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
425 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
426 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
427 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
429 else if (test_bit(In_sync
, &rdev
->flags
))
432 /* not in-sync or faulty.
433 * If reshape increases the number of devices, this
434 * section has already been recovered, else it
435 * almost certainly hasn't.
437 if (conf
->raid_disks
<= conf
->previous_raid_disks
)
441 if (degraded2
> degraded
)
446 static int has_failed(struct r5conf
*conf
)
450 if (conf
->mddev
->reshape_position
== MaxSector
)
451 return conf
->mddev
->degraded
> conf
->max_degraded
;
453 degraded
= calc_degraded(conf
);
454 if (degraded
> conf
->max_degraded
)
459 static struct stripe_head
*
460 get_active_stripe(struct r5conf
*conf
, sector_t sector
,
461 int previous
, int noblock
, int noquiesce
)
463 struct stripe_head
*sh
;
465 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
467 spin_lock_irq(&conf
->device_lock
);
470 wait_event_lock_irq(conf
->wait_for_stripe
,
471 conf
->quiesce
== 0 || noquiesce
,
473 sh
= __find_stripe(conf
, sector
, conf
->generation
- previous
);
475 if (!conf
->inactive_blocked
)
476 sh
= get_free_stripe(conf
);
477 if (noblock
&& sh
== NULL
)
480 conf
->inactive_blocked
= 1;
481 wait_event_lock_irq(conf
->wait_for_stripe
,
482 !list_empty(&conf
->inactive_list
) &&
483 (atomic_read(&conf
->active_stripes
)
484 < (conf
->max_nr_stripes
*3/4)
485 || !conf
->inactive_blocked
),
487 conf
->inactive_blocked
= 0;
489 init_stripe(sh
, sector
, previous
);
491 if (atomic_read(&sh
->count
)) {
492 BUG_ON(!list_empty(&sh
->lru
)
493 && !test_bit(STRIPE_EXPANDING
, &sh
->state
)
494 && !test_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
));
496 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
497 atomic_inc(&conf
->active_stripes
);
498 if (list_empty(&sh
->lru
) &&
499 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
501 list_del_init(&sh
->lru
);
504 } while (sh
== NULL
);
507 atomic_inc(&sh
->count
);
509 spin_unlock_irq(&conf
->device_lock
);
513 /* Determine if 'data_offset' or 'new_data_offset' should be used
514 * in this stripe_head.
516 static int use_new_offset(struct r5conf
*conf
, struct stripe_head
*sh
)
518 sector_t progress
= conf
->reshape_progress
;
519 /* Need a memory barrier to make sure we see the value
520 * of conf->generation, or ->data_offset that was set before
521 * reshape_progress was updated.
524 if (progress
== MaxSector
)
526 if (sh
->generation
== conf
->generation
- 1)
528 /* We are in a reshape, and this is a new-generation stripe,
529 * so use new_data_offset.
535 raid5_end_read_request(struct bio
*bi
, int error
);
537 raid5_end_write_request(struct bio
*bi
, int error
);
539 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
541 struct r5conf
*conf
= sh
->raid_conf
;
542 int i
, disks
= sh
->disks
;
546 for (i
= disks
; i
--; ) {
548 int replace_only
= 0;
549 struct bio
*bi
, *rbi
;
550 struct md_rdev
*rdev
, *rrdev
= NULL
;
551 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
)) {
552 if (test_and_clear_bit(R5_WantFUA
, &sh
->dev
[i
].flags
))
556 if (test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
558 } else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
560 else if (test_and_clear_bit(R5_WantReplace
,
561 &sh
->dev
[i
].flags
)) {
566 if (test_and_clear_bit(R5_SyncIO
, &sh
->dev
[i
].flags
))
569 bi
= &sh
->dev
[i
].req
;
570 rbi
= &sh
->dev
[i
].rreq
; /* For writing to replacement */
575 bi
->bi_end_io
= raid5_end_write_request
;
576 rbi
->bi_end_io
= raid5_end_write_request
;
578 bi
->bi_end_io
= raid5_end_read_request
;
581 rrdev
= rcu_dereference(conf
->disks
[i
].replacement
);
582 smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
583 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
592 /* We raced and saw duplicates */
595 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
) && rrdev
)
600 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
603 atomic_inc(&rdev
->nr_pending
);
604 if (rrdev
&& test_bit(Faulty
, &rrdev
->flags
))
607 atomic_inc(&rrdev
->nr_pending
);
610 /* We have already checked bad blocks for reads. Now
611 * need to check for writes. We never accept write errors
612 * on the replacement, so we don't to check rrdev.
614 while ((rw
& WRITE
) && rdev
&&
615 test_bit(WriteErrorSeen
, &rdev
->flags
)) {
618 int bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
619 &first_bad
, &bad_sectors
);
624 set_bit(BlockedBadBlocks
, &rdev
->flags
);
625 if (!conf
->mddev
->external
&&
626 conf
->mddev
->flags
) {
627 /* It is very unlikely, but we might
628 * still need to write out the
629 * bad block log - better give it
631 md_check_recovery(conf
->mddev
);
634 * Because md_wait_for_blocked_rdev
635 * will dec nr_pending, we must
636 * increment it first.
638 atomic_inc(&rdev
->nr_pending
);
639 md_wait_for_blocked_rdev(rdev
, conf
->mddev
);
641 /* Acknowledged bad block - skip the write */
642 rdev_dec_pending(rdev
, conf
->mddev
);
648 if (s
->syncing
|| s
->expanding
|| s
->expanded
650 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
652 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
654 bi
->bi_bdev
= rdev
->bdev
;
655 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
656 __func__
, (unsigned long long)sh
->sector
,
658 atomic_inc(&sh
->count
);
659 if (use_new_offset(conf
, sh
))
660 bi
->bi_sector
= (sh
->sector
661 + rdev
->new_data_offset
);
663 bi
->bi_sector
= (sh
->sector
664 + rdev
->data_offset
);
665 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
666 bi
->bi_rw
|= REQ_FLUSH
;
668 bi
->bi_flags
= 1 << BIO_UPTODATE
;
670 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
671 bi
->bi_io_vec
[0].bv_offset
= 0;
672 bi
->bi_size
= STRIPE_SIZE
;
675 set_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
);
677 if (conf
->mddev
->gendisk
)
678 trace_block_bio_remap(bdev_get_queue(bi
->bi_bdev
),
679 bi
, disk_devt(conf
->mddev
->gendisk
),
681 generic_make_request(bi
);
684 if (s
->syncing
|| s
->expanding
|| s
->expanded
686 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
688 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
690 rbi
->bi_bdev
= rrdev
->bdev
;
691 pr_debug("%s: for %llu schedule op %ld on "
692 "replacement disc %d\n",
693 __func__
, (unsigned long long)sh
->sector
,
695 atomic_inc(&sh
->count
);
696 if (use_new_offset(conf
, sh
))
697 rbi
->bi_sector
= (sh
->sector
698 + rrdev
->new_data_offset
);
700 rbi
->bi_sector
= (sh
->sector
701 + rrdev
->data_offset
);
702 rbi
->bi_flags
= 1 << BIO_UPTODATE
;
704 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
705 rbi
->bi_io_vec
[0].bv_offset
= 0;
706 rbi
->bi_size
= STRIPE_SIZE
;
708 if (conf
->mddev
->gendisk
)
709 trace_block_bio_remap(bdev_get_queue(rbi
->bi_bdev
),
710 rbi
, disk_devt(conf
->mddev
->gendisk
),
712 generic_make_request(rbi
);
714 if (!rdev
&& !rrdev
) {
716 set_bit(STRIPE_DEGRADED
, &sh
->state
);
717 pr_debug("skip op %ld on disc %d for sector %llu\n",
718 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
719 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
720 set_bit(STRIPE_HANDLE
, &sh
->state
);
725 static struct dma_async_tx_descriptor
*
726 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
727 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
730 struct page
*bio_page
;
733 struct async_submit_ctl submit
;
734 enum async_tx_flags flags
= 0;
736 if (bio
->bi_sector
>= sector
)
737 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
739 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
742 flags
|= ASYNC_TX_FENCE
;
743 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
745 bio_for_each_segment(bvl
, bio
, i
) {
746 int len
= bvl
->bv_len
;
750 if (page_offset
< 0) {
751 b_offset
= -page_offset
;
752 page_offset
+= b_offset
;
756 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
757 clen
= STRIPE_SIZE
- page_offset
;
762 b_offset
+= bvl
->bv_offset
;
763 bio_page
= bvl
->bv_page
;
765 tx
= async_memcpy(page
, bio_page
, page_offset
,
766 b_offset
, clen
, &submit
);
768 tx
= async_memcpy(bio_page
, page
, b_offset
,
769 page_offset
, clen
, &submit
);
771 /* chain the operations */
772 submit
.depend_tx
= tx
;
774 if (clen
< len
) /* hit end of page */
782 static void ops_complete_biofill(void *stripe_head_ref
)
784 struct stripe_head
*sh
= stripe_head_ref
;
785 struct bio
*return_bi
= NULL
;
788 pr_debug("%s: stripe %llu\n", __func__
,
789 (unsigned long long)sh
->sector
);
791 /* clear completed biofills */
792 for (i
= sh
->disks
; i
--; ) {
793 struct r5dev
*dev
= &sh
->dev
[i
];
795 /* acknowledge completion of a biofill operation */
796 /* and check if we need to reply to a read request,
797 * new R5_Wantfill requests are held off until
798 * !STRIPE_BIOFILL_RUN
800 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
801 struct bio
*rbi
, *rbi2
;
806 while (rbi
&& rbi
->bi_sector
<
807 dev
->sector
+ STRIPE_SECTORS
) {
808 rbi2
= r5_next_bio(rbi
, dev
->sector
);
809 if (!raid5_dec_bi_active_stripes(rbi
)) {
810 rbi
->bi_next
= return_bi
;
817 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
819 return_io(return_bi
);
821 set_bit(STRIPE_HANDLE
, &sh
->state
);
825 static void ops_run_biofill(struct stripe_head
*sh
)
827 struct dma_async_tx_descriptor
*tx
= NULL
;
828 struct async_submit_ctl submit
;
831 pr_debug("%s: stripe %llu\n", __func__
,
832 (unsigned long long)sh
->sector
);
834 for (i
= sh
->disks
; i
--; ) {
835 struct r5dev
*dev
= &sh
->dev
[i
];
836 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
838 spin_lock_irq(&sh
->stripe_lock
);
839 dev
->read
= rbi
= dev
->toread
;
841 spin_unlock_irq(&sh
->stripe_lock
);
842 while (rbi
&& rbi
->bi_sector
<
843 dev
->sector
+ STRIPE_SECTORS
) {
844 tx
= async_copy_data(0, rbi
, dev
->page
,
846 rbi
= r5_next_bio(rbi
, dev
->sector
);
851 atomic_inc(&sh
->count
);
852 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
853 async_trigger_callback(&submit
);
856 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
863 tgt
= &sh
->dev
[target
];
864 set_bit(R5_UPTODATE
, &tgt
->flags
);
865 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
866 clear_bit(R5_Wantcompute
, &tgt
->flags
);
869 static void ops_complete_compute(void *stripe_head_ref
)
871 struct stripe_head
*sh
= stripe_head_ref
;
873 pr_debug("%s: stripe %llu\n", __func__
,
874 (unsigned long long)sh
->sector
);
876 /* mark the computed target(s) as uptodate */
877 mark_target_uptodate(sh
, sh
->ops
.target
);
878 mark_target_uptodate(sh
, sh
->ops
.target2
);
880 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
881 if (sh
->check_state
== check_state_compute_run
)
882 sh
->check_state
= check_state_compute_result
;
883 set_bit(STRIPE_HANDLE
, &sh
->state
);
887 /* return a pointer to the address conversion region of the scribble buffer */
888 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
889 struct raid5_percpu
*percpu
)
891 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
894 static struct dma_async_tx_descriptor
*
895 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
897 int disks
= sh
->disks
;
898 struct page
**xor_srcs
= percpu
->scribble
;
899 int target
= sh
->ops
.target
;
900 struct r5dev
*tgt
= &sh
->dev
[target
];
901 struct page
*xor_dest
= tgt
->page
;
903 struct dma_async_tx_descriptor
*tx
;
904 struct async_submit_ctl submit
;
907 pr_debug("%s: stripe %llu block: %d\n",
908 __func__
, (unsigned long long)sh
->sector
, target
);
909 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
911 for (i
= disks
; i
--; )
913 xor_srcs
[count
++] = sh
->dev
[i
].page
;
915 atomic_inc(&sh
->count
);
917 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
918 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
919 if (unlikely(count
== 1))
920 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
922 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
927 /* set_syndrome_sources - populate source buffers for gen_syndrome
928 * @srcs - (struct page *) array of size sh->disks
929 * @sh - stripe_head to parse
931 * Populates srcs in proper layout order for the stripe and returns the
932 * 'count' of sources to be used in a call to async_gen_syndrome. The P
933 * destination buffer is recorded in srcs[count] and the Q destination
934 * is recorded in srcs[count+1]].
936 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
938 int disks
= sh
->disks
;
939 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
940 int d0_idx
= raid6_d0(sh
);
944 for (i
= 0; i
< disks
; i
++)
950 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
952 srcs
[slot
] = sh
->dev
[i
].page
;
953 i
= raid6_next_disk(i
, disks
);
954 } while (i
!= d0_idx
);
956 return syndrome_disks
;
959 static struct dma_async_tx_descriptor
*
960 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
962 int disks
= sh
->disks
;
963 struct page
**blocks
= percpu
->scribble
;
965 int qd_idx
= sh
->qd_idx
;
966 struct dma_async_tx_descriptor
*tx
;
967 struct async_submit_ctl submit
;
973 if (sh
->ops
.target
< 0)
974 target
= sh
->ops
.target2
;
975 else if (sh
->ops
.target2
< 0)
976 target
= sh
->ops
.target
;
978 /* we should only have one valid target */
981 pr_debug("%s: stripe %llu block: %d\n",
982 __func__
, (unsigned long long)sh
->sector
, target
);
984 tgt
= &sh
->dev
[target
];
985 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
988 atomic_inc(&sh
->count
);
990 if (target
== qd_idx
) {
991 count
= set_syndrome_sources(blocks
, sh
);
992 blocks
[count
] = NULL
; /* regenerating p is not necessary */
993 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
994 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
995 ops_complete_compute
, sh
,
996 to_addr_conv(sh
, percpu
));
997 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
999 /* Compute any data- or p-drive using XOR */
1001 for (i
= disks
; i
-- ; ) {
1002 if (i
== target
|| i
== qd_idx
)
1004 blocks
[count
++] = sh
->dev
[i
].page
;
1007 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1008 NULL
, ops_complete_compute
, sh
,
1009 to_addr_conv(sh
, percpu
));
1010 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
1016 static struct dma_async_tx_descriptor
*
1017 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1019 int i
, count
, disks
= sh
->disks
;
1020 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1021 int d0_idx
= raid6_d0(sh
);
1022 int faila
= -1, failb
= -1;
1023 int target
= sh
->ops
.target
;
1024 int target2
= sh
->ops
.target2
;
1025 struct r5dev
*tgt
= &sh
->dev
[target
];
1026 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1027 struct dma_async_tx_descriptor
*tx
;
1028 struct page
**blocks
= percpu
->scribble
;
1029 struct async_submit_ctl submit
;
1031 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1032 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1033 BUG_ON(target
< 0 || target2
< 0);
1034 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1035 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1037 /* we need to open-code set_syndrome_sources to handle the
1038 * slot number conversion for 'faila' and 'failb'
1040 for (i
= 0; i
< disks
; i
++)
1045 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1047 blocks
[slot
] = sh
->dev
[i
].page
;
1053 i
= raid6_next_disk(i
, disks
);
1054 } while (i
!= d0_idx
);
1056 BUG_ON(faila
== failb
);
1059 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1060 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1062 atomic_inc(&sh
->count
);
1064 if (failb
== syndrome_disks
+1) {
1065 /* Q disk is one of the missing disks */
1066 if (faila
== syndrome_disks
) {
1067 /* Missing P+Q, just recompute */
1068 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1069 ops_complete_compute
, sh
,
1070 to_addr_conv(sh
, percpu
));
1071 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1072 STRIPE_SIZE
, &submit
);
1076 int qd_idx
= sh
->qd_idx
;
1078 /* Missing D+Q: recompute D from P, then recompute Q */
1079 if (target
== qd_idx
)
1080 data_target
= target2
;
1082 data_target
= target
;
1085 for (i
= disks
; i
-- ; ) {
1086 if (i
== data_target
|| i
== qd_idx
)
1088 blocks
[count
++] = sh
->dev
[i
].page
;
1090 dest
= sh
->dev
[data_target
].page
;
1091 init_async_submit(&submit
,
1092 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1094 to_addr_conv(sh
, percpu
));
1095 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1098 count
= set_syndrome_sources(blocks
, sh
);
1099 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1100 ops_complete_compute
, sh
,
1101 to_addr_conv(sh
, percpu
));
1102 return async_gen_syndrome(blocks
, 0, count
+2,
1103 STRIPE_SIZE
, &submit
);
1106 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1107 ops_complete_compute
, sh
,
1108 to_addr_conv(sh
, percpu
));
1109 if (failb
== syndrome_disks
) {
1110 /* We're missing D+P. */
1111 return async_raid6_datap_recov(syndrome_disks
+2,
1115 /* We're missing D+D. */
1116 return async_raid6_2data_recov(syndrome_disks
+2,
1117 STRIPE_SIZE
, faila
, failb
,
1124 static void ops_complete_prexor(void *stripe_head_ref
)
1126 struct stripe_head
*sh
= stripe_head_ref
;
1128 pr_debug("%s: stripe %llu\n", __func__
,
1129 (unsigned long long)sh
->sector
);
1132 static struct dma_async_tx_descriptor
*
1133 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1134 struct dma_async_tx_descriptor
*tx
)
1136 int disks
= sh
->disks
;
1137 struct page
**xor_srcs
= percpu
->scribble
;
1138 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1139 struct async_submit_ctl submit
;
1141 /* existing parity data subtracted */
1142 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1144 pr_debug("%s: stripe %llu\n", __func__
,
1145 (unsigned long long)sh
->sector
);
1147 for (i
= disks
; i
--; ) {
1148 struct r5dev
*dev
= &sh
->dev
[i
];
1149 /* Only process blocks that are known to be uptodate */
1150 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1151 xor_srcs
[count
++] = dev
->page
;
1154 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1155 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1156 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1161 static struct dma_async_tx_descriptor
*
1162 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1164 int disks
= sh
->disks
;
1167 pr_debug("%s: stripe %llu\n", __func__
,
1168 (unsigned long long)sh
->sector
);
1170 for (i
= disks
; i
--; ) {
1171 struct r5dev
*dev
= &sh
->dev
[i
];
1174 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1177 spin_lock_irq(&sh
->stripe_lock
);
1178 chosen
= dev
->towrite
;
1179 dev
->towrite
= NULL
;
1180 BUG_ON(dev
->written
);
1181 wbi
= dev
->written
= chosen
;
1182 spin_unlock_irq(&sh
->stripe_lock
);
1184 while (wbi
&& wbi
->bi_sector
<
1185 dev
->sector
+ STRIPE_SECTORS
) {
1186 if (wbi
->bi_rw
& REQ_FUA
)
1187 set_bit(R5_WantFUA
, &dev
->flags
);
1188 if (wbi
->bi_rw
& REQ_SYNC
)
1189 set_bit(R5_SyncIO
, &dev
->flags
);
1190 if (wbi
->bi_rw
& REQ_DISCARD
)
1191 set_bit(R5_Discard
, &dev
->flags
);
1193 tx
= async_copy_data(1, wbi
, dev
->page
,
1195 wbi
= r5_next_bio(wbi
, dev
->sector
);
1203 static void ops_complete_reconstruct(void *stripe_head_ref
)
1205 struct stripe_head
*sh
= stripe_head_ref
;
1206 int disks
= sh
->disks
;
1207 int pd_idx
= sh
->pd_idx
;
1208 int qd_idx
= sh
->qd_idx
;
1210 bool fua
= false, sync
= false, discard
= false;
1212 pr_debug("%s: stripe %llu\n", __func__
,
1213 (unsigned long long)sh
->sector
);
1215 for (i
= disks
; i
--; ) {
1216 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1217 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1218 discard
|= test_bit(R5_Discard
, &sh
->dev
[i
].flags
);
1221 for (i
= disks
; i
--; ) {
1222 struct r5dev
*dev
= &sh
->dev
[i
];
1224 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1226 set_bit(R5_UPTODATE
, &dev
->flags
);
1228 set_bit(R5_WantFUA
, &dev
->flags
);
1230 set_bit(R5_SyncIO
, &dev
->flags
);
1234 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1235 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1236 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1237 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1239 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1240 sh
->reconstruct_state
= reconstruct_state_result
;
1243 set_bit(STRIPE_HANDLE
, &sh
->state
);
1248 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1249 struct dma_async_tx_descriptor
*tx
)
1251 int disks
= sh
->disks
;
1252 struct page
**xor_srcs
= percpu
->scribble
;
1253 struct async_submit_ctl submit
;
1254 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1255 struct page
*xor_dest
;
1257 unsigned long flags
;
1259 pr_debug("%s: stripe %llu\n", __func__
,
1260 (unsigned long long)sh
->sector
);
1262 for (i
= 0; i
< sh
->disks
; i
++) {
1265 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1268 if (i
>= sh
->disks
) {
1269 atomic_inc(&sh
->count
);
1270 set_bit(R5_Discard
, &sh
->dev
[pd_idx
].flags
);
1271 ops_complete_reconstruct(sh
);
1274 /* check if prexor is active which means only process blocks
1275 * that are part of a read-modify-write (written)
1277 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1279 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1280 for (i
= disks
; i
--; ) {
1281 struct r5dev
*dev
= &sh
->dev
[i
];
1283 xor_srcs
[count
++] = dev
->page
;
1286 xor_dest
= sh
->dev
[pd_idx
].page
;
1287 for (i
= disks
; i
--; ) {
1288 struct r5dev
*dev
= &sh
->dev
[i
];
1290 xor_srcs
[count
++] = dev
->page
;
1294 /* 1/ if we prexor'd then the dest is reused as a source
1295 * 2/ if we did not prexor then we are redoing the parity
1296 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1297 * for the synchronous xor case
1299 flags
= ASYNC_TX_ACK
|
1300 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1302 atomic_inc(&sh
->count
);
1304 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1305 to_addr_conv(sh
, percpu
));
1306 if (unlikely(count
== 1))
1307 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1309 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1313 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1314 struct dma_async_tx_descriptor
*tx
)
1316 struct async_submit_ctl submit
;
1317 struct page
**blocks
= percpu
->scribble
;
1320 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1322 for (i
= 0; i
< sh
->disks
; i
++) {
1323 if (sh
->pd_idx
== i
|| sh
->qd_idx
== i
)
1325 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1328 if (i
>= sh
->disks
) {
1329 atomic_inc(&sh
->count
);
1330 set_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
1331 set_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
1332 ops_complete_reconstruct(sh
);
1336 count
= set_syndrome_sources(blocks
, sh
);
1338 atomic_inc(&sh
->count
);
1340 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1341 sh
, to_addr_conv(sh
, percpu
));
1342 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1345 static void ops_complete_check(void *stripe_head_ref
)
1347 struct stripe_head
*sh
= stripe_head_ref
;
1349 pr_debug("%s: stripe %llu\n", __func__
,
1350 (unsigned long long)sh
->sector
);
1352 sh
->check_state
= check_state_check_result
;
1353 set_bit(STRIPE_HANDLE
, &sh
->state
);
1357 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1359 int disks
= sh
->disks
;
1360 int pd_idx
= sh
->pd_idx
;
1361 int qd_idx
= sh
->qd_idx
;
1362 struct page
*xor_dest
;
1363 struct page
**xor_srcs
= percpu
->scribble
;
1364 struct dma_async_tx_descriptor
*tx
;
1365 struct async_submit_ctl submit
;
1369 pr_debug("%s: stripe %llu\n", __func__
,
1370 (unsigned long long)sh
->sector
);
1373 xor_dest
= sh
->dev
[pd_idx
].page
;
1374 xor_srcs
[count
++] = xor_dest
;
1375 for (i
= disks
; i
--; ) {
1376 if (i
== pd_idx
|| i
== qd_idx
)
1378 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1381 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1382 to_addr_conv(sh
, percpu
));
1383 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1384 &sh
->ops
.zero_sum_result
, &submit
);
1386 atomic_inc(&sh
->count
);
1387 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1388 tx
= async_trigger_callback(&submit
);
1391 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1393 struct page
**srcs
= percpu
->scribble
;
1394 struct async_submit_ctl submit
;
1397 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1398 (unsigned long long)sh
->sector
, checkp
);
1400 count
= set_syndrome_sources(srcs
, sh
);
1404 atomic_inc(&sh
->count
);
1405 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1406 sh
, to_addr_conv(sh
, percpu
));
1407 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1408 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1411 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1413 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1414 struct dma_async_tx_descriptor
*tx
= NULL
;
1415 struct r5conf
*conf
= sh
->raid_conf
;
1416 int level
= conf
->level
;
1417 struct raid5_percpu
*percpu
;
1421 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1422 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1423 ops_run_biofill(sh
);
1427 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1429 tx
= ops_run_compute5(sh
, percpu
);
1431 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1432 tx
= ops_run_compute6_1(sh
, percpu
);
1434 tx
= ops_run_compute6_2(sh
, percpu
);
1436 /* terminate the chain if reconstruct is not set to be run */
1437 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1441 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1442 tx
= ops_run_prexor(sh
, percpu
, tx
);
1444 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1445 tx
= ops_run_biodrain(sh
, tx
);
1449 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1451 ops_run_reconstruct5(sh
, percpu
, tx
);
1453 ops_run_reconstruct6(sh
, percpu
, tx
);
1456 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1457 if (sh
->check_state
== check_state_run
)
1458 ops_run_check_p(sh
, percpu
);
1459 else if (sh
->check_state
== check_state_run_q
)
1460 ops_run_check_pq(sh
, percpu
, 0);
1461 else if (sh
->check_state
== check_state_run_pq
)
1462 ops_run_check_pq(sh
, percpu
, 1);
1468 for (i
= disks
; i
--; ) {
1469 struct r5dev
*dev
= &sh
->dev
[i
];
1470 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1471 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1476 static int grow_one_stripe(struct r5conf
*conf
)
1478 struct stripe_head
*sh
;
1479 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1483 sh
->raid_conf
= conf
;
1485 spin_lock_init(&sh
->stripe_lock
);
1487 if (grow_buffers(sh
)) {
1489 kmem_cache_free(conf
->slab_cache
, sh
);
1492 /* we just created an active stripe so... */
1493 atomic_set(&sh
->count
, 1);
1494 atomic_inc(&conf
->active_stripes
);
1495 INIT_LIST_HEAD(&sh
->lru
);
1500 static int grow_stripes(struct r5conf
*conf
, int num
)
1502 struct kmem_cache
*sc
;
1503 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1505 if (conf
->mddev
->gendisk
)
1506 sprintf(conf
->cache_name
[0],
1507 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1509 sprintf(conf
->cache_name
[0],
1510 "raid%d-%p", conf
->level
, conf
->mddev
);
1511 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1513 conf
->active_name
= 0;
1514 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1515 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1519 conf
->slab_cache
= sc
;
1520 conf
->pool_size
= devs
;
1522 if (!grow_one_stripe(conf
))
1528 * scribble_len - return the required size of the scribble region
1529 * @num - total number of disks in the array
1531 * The size must be enough to contain:
1532 * 1/ a struct page pointer for each device in the array +2
1533 * 2/ room to convert each entry in (1) to its corresponding dma
1534 * (dma_map_page()) or page (page_address()) address.
1536 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1537 * calculate over all devices (not just the data blocks), using zeros in place
1538 * of the P and Q blocks.
1540 static size_t scribble_len(int num
)
1544 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1549 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1551 /* Make all the stripes able to hold 'newsize' devices.
1552 * New slots in each stripe get 'page' set to a new page.
1554 * This happens in stages:
1555 * 1/ create a new kmem_cache and allocate the required number of
1557 * 2/ gather all the old stripe_heads and transfer the pages across
1558 * to the new stripe_heads. This will have the side effect of
1559 * freezing the array as once all stripe_heads have been collected,
1560 * no IO will be possible. Old stripe heads are freed once their
1561 * pages have been transferred over, and the old kmem_cache is
1562 * freed when all stripes are done.
1563 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1564 * we simple return a failre status - no need to clean anything up.
1565 * 4/ allocate new pages for the new slots in the new stripe_heads.
1566 * If this fails, we don't bother trying the shrink the
1567 * stripe_heads down again, we just leave them as they are.
1568 * As each stripe_head is processed the new one is released into
1571 * Once step2 is started, we cannot afford to wait for a write,
1572 * so we use GFP_NOIO allocations.
1574 struct stripe_head
*osh
, *nsh
;
1575 LIST_HEAD(newstripes
);
1576 struct disk_info
*ndisks
;
1579 struct kmem_cache
*sc
;
1582 if (newsize
<= conf
->pool_size
)
1583 return 0; /* never bother to shrink */
1585 err
= md_allow_write(conf
->mddev
);
1590 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1591 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1596 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1597 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1601 nsh
->raid_conf
= conf
;
1602 spin_lock_init(&nsh
->stripe_lock
);
1604 list_add(&nsh
->lru
, &newstripes
);
1607 /* didn't get enough, give up */
1608 while (!list_empty(&newstripes
)) {
1609 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1610 list_del(&nsh
->lru
);
1611 kmem_cache_free(sc
, nsh
);
1613 kmem_cache_destroy(sc
);
1616 /* Step 2 - Must use GFP_NOIO now.
1617 * OK, we have enough stripes, start collecting inactive
1618 * stripes and copying them over
1620 list_for_each_entry(nsh
, &newstripes
, lru
) {
1621 spin_lock_irq(&conf
->device_lock
);
1622 wait_event_lock_irq(conf
->wait_for_stripe
,
1623 !list_empty(&conf
->inactive_list
),
1625 osh
= get_free_stripe(conf
);
1626 spin_unlock_irq(&conf
->device_lock
);
1627 atomic_set(&nsh
->count
, 1);
1628 for(i
=0; i
<conf
->pool_size
; i
++)
1629 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1630 for( ; i
<newsize
; i
++)
1631 nsh
->dev
[i
].page
= NULL
;
1632 kmem_cache_free(conf
->slab_cache
, osh
);
1634 kmem_cache_destroy(conf
->slab_cache
);
1637 * At this point, we are holding all the stripes so the array
1638 * is completely stalled, so now is a good time to resize
1639 * conf->disks and the scribble region
1641 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1643 for (i
=0; i
<conf
->raid_disks
; i
++)
1644 ndisks
[i
] = conf
->disks
[i
];
1646 conf
->disks
= ndisks
;
1651 conf
->scribble_len
= scribble_len(newsize
);
1652 for_each_present_cpu(cpu
) {
1653 struct raid5_percpu
*percpu
;
1656 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1657 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1660 kfree(percpu
->scribble
);
1661 percpu
->scribble
= scribble
;
1669 /* Step 4, return new stripes to service */
1670 while(!list_empty(&newstripes
)) {
1671 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1672 list_del_init(&nsh
->lru
);
1674 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1675 if (nsh
->dev
[i
].page
== NULL
) {
1676 struct page
*p
= alloc_page(GFP_NOIO
);
1677 nsh
->dev
[i
].page
= p
;
1681 release_stripe(nsh
);
1683 /* critical section pass, GFP_NOIO no longer needed */
1685 conf
->slab_cache
= sc
;
1686 conf
->active_name
= 1-conf
->active_name
;
1687 conf
->pool_size
= newsize
;
1691 static int drop_one_stripe(struct r5conf
*conf
)
1693 struct stripe_head
*sh
;
1695 spin_lock_irq(&conf
->device_lock
);
1696 sh
= get_free_stripe(conf
);
1697 spin_unlock_irq(&conf
->device_lock
);
1700 BUG_ON(atomic_read(&sh
->count
));
1702 kmem_cache_free(conf
->slab_cache
, sh
);
1703 atomic_dec(&conf
->active_stripes
);
1707 static void shrink_stripes(struct r5conf
*conf
)
1709 while (drop_one_stripe(conf
))
1712 if (conf
->slab_cache
)
1713 kmem_cache_destroy(conf
->slab_cache
);
1714 conf
->slab_cache
= NULL
;
1717 static void raid5_end_read_request(struct bio
* bi
, int error
)
1719 struct stripe_head
*sh
= bi
->bi_private
;
1720 struct r5conf
*conf
= sh
->raid_conf
;
1721 int disks
= sh
->disks
, i
;
1722 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1723 char b
[BDEVNAME_SIZE
];
1724 struct md_rdev
*rdev
= NULL
;
1727 for (i
=0 ; i
<disks
; i
++)
1728 if (bi
== &sh
->dev
[i
].req
)
1731 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1732 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1738 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1739 /* If replacement finished while this request was outstanding,
1740 * 'replacement' might be NULL already.
1741 * In that case it moved down to 'rdev'.
1742 * rdev is not removed until all requests are finished.
1744 rdev
= conf
->disks
[i
].replacement
;
1746 rdev
= conf
->disks
[i
].rdev
;
1748 if (use_new_offset(conf
, sh
))
1749 s
= sh
->sector
+ rdev
->new_data_offset
;
1751 s
= sh
->sector
+ rdev
->data_offset
;
1753 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1754 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1755 /* Note that this cannot happen on a
1756 * replacement device. We just fail those on
1761 "md/raid:%s: read error corrected"
1762 " (%lu sectors at %llu on %s)\n",
1763 mdname(conf
->mddev
), STRIPE_SECTORS
,
1764 (unsigned long long)s
,
1765 bdevname(rdev
->bdev
, b
));
1766 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1767 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1768 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1769 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1770 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1772 if (atomic_read(&rdev
->read_errors
))
1773 atomic_set(&rdev
->read_errors
, 0);
1775 const char *bdn
= bdevname(rdev
->bdev
, b
);
1779 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1780 atomic_inc(&rdev
->read_errors
);
1781 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1784 "md/raid:%s: read error on replacement device "
1785 "(sector %llu on %s).\n",
1786 mdname(conf
->mddev
),
1787 (unsigned long long)s
,
1789 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1793 "md/raid:%s: read error not correctable "
1794 "(sector %llu on %s).\n",
1795 mdname(conf
->mddev
),
1796 (unsigned long long)s
,
1798 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1803 "md/raid:%s: read error NOT corrected!! "
1804 "(sector %llu on %s).\n",
1805 mdname(conf
->mddev
),
1806 (unsigned long long)s
,
1808 } else if (atomic_read(&rdev
->read_errors
)
1809 > conf
->max_nr_stripes
)
1811 "md/raid:%s: Too many read errors, failing device %s.\n",
1812 mdname(conf
->mddev
), bdn
);
1816 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1817 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1818 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1820 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1822 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1823 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1825 && test_bit(In_sync
, &rdev
->flags
)
1826 && rdev_set_badblocks(
1827 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1828 md_error(conf
->mddev
, rdev
);
1831 rdev_dec_pending(rdev
, conf
->mddev
);
1832 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1833 set_bit(STRIPE_HANDLE
, &sh
->state
);
1837 static void raid5_end_write_request(struct bio
*bi
, int error
)
1839 struct stripe_head
*sh
= bi
->bi_private
;
1840 struct r5conf
*conf
= sh
->raid_conf
;
1841 int disks
= sh
->disks
, i
;
1842 struct md_rdev
*uninitialized_var(rdev
);
1843 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1846 int replacement
= 0;
1848 for (i
= 0 ; i
< disks
; i
++) {
1849 if (bi
== &sh
->dev
[i
].req
) {
1850 rdev
= conf
->disks
[i
].rdev
;
1853 if (bi
== &sh
->dev
[i
].rreq
) {
1854 rdev
= conf
->disks
[i
].replacement
;
1858 /* rdev was removed and 'replacement'
1859 * replaced it. rdev is not removed
1860 * until all requests are finished.
1862 rdev
= conf
->disks
[i
].rdev
;
1866 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1867 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1876 md_error(conf
->mddev
, rdev
);
1877 else if (is_badblock(rdev
, sh
->sector
,
1879 &first_bad
, &bad_sectors
))
1880 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1883 set_bit(WriteErrorSeen
, &rdev
->flags
);
1884 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1885 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1886 set_bit(MD_RECOVERY_NEEDED
,
1887 &rdev
->mddev
->recovery
);
1888 } else if (is_badblock(rdev
, sh
->sector
,
1890 &first_bad
, &bad_sectors
))
1891 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1893 rdev_dec_pending(rdev
, conf
->mddev
);
1895 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1896 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1897 set_bit(STRIPE_HANDLE
, &sh
->state
);
1901 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1903 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1905 struct r5dev
*dev
= &sh
->dev
[i
];
1907 bio_init(&dev
->req
);
1908 dev
->req
.bi_io_vec
= &dev
->vec
;
1910 dev
->req
.bi_max_vecs
++;
1911 dev
->req
.bi_private
= sh
;
1912 dev
->vec
.bv_page
= dev
->page
;
1914 bio_init(&dev
->rreq
);
1915 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1916 dev
->rreq
.bi_vcnt
++;
1917 dev
->rreq
.bi_max_vecs
++;
1918 dev
->rreq
.bi_private
= sh
;
1919 dev
->rvec
.bv_page
= dev
->page
;
1922 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1925 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1927 char b
[BDEVNAME_SIZE
];
1928 struct r5conf
*conf
= mddev
->private;
1929 unsigned long flags
;
1930 pr_debug("raid456: error called\n");
1932 spin_lock_irqsave(&conf
->device_lock
, flags
);
1933 clear_bit(In_sync
, &rdev
->flags
);
1934 mddev
->degraded
= calc_degraded(conf
);
1935 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1936 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1938 set_bit(Blocked
, &rdev
->flags
);
1939 set_bit(Faulty
, &rdev
->flags
);
1940 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1942 "md/raid:%s: Disk failure on %s, disabling device.\n"
1943 "md/raid:%s: Operation continuing on %d devices.\n",
1945 bdevname(rdev
->bdev
, b
),
1947 conf
->raid_disks
- mddev
->degraded
);
1951 * Input: a 'big' sector number,
1952 * Output: index of the data and parity disk, and the sector # in them.
1954 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1955 int previous
, int *dd_idx
,
1956 struct stripe_head
*sh
)
1958 sector_t stripe
, stripe2
;
1959 sector_t chunk_number
;
1960 unsigned int chunk_offset
;
1963 sector_t new_sector
;
1964 int algorithm
= previous
? conf
->prev_algo
1966 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1967 : conf
->chunk_sectors
;
1968 int raid_disks
= previous
? conf
->previous_raid_disks
1970 int data_disks
= raid_disks
- conf
->max_degraded
;
1972 /* First compute the information on this sector */
1975 * Compute the chunk number and the sector offset inside the chunk
1977 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1978 chunk_number
= r_sector
;
1981 * Compute the stripe number
1983 stripe
= chunk_number
;
1984 *dd_idx
= sector_div(stripe
, data_disks
);
1987 * Select the parity disk based on the user selected algorithm.
1989 pd_idx
= qd_idx
= -1;
1990 switch(conf
->level
) {
1992 pd_idx
= data_disks
;
1995 switch (algorithm
) {
1996 case ALGORITHM_LEFT_ASYMMETRIC
:
1997 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1998 if (*dd_idx
>= pd_idx
)
2001 case ALGORITHM_RIGHT_ASYMMETRIC
:
2002 pd_idx
= sector_div(stripe2
, raid_disks
);
2003 if (*dd_idx
>= pd_idx
)
2006 case ALGORITHM_LEFT_SYMMETRIC
:
2007 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2008 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2010 case ALGORITHM_RIGHT_SYMMETRIC
:
2011 pd_idx
= sector_div(stripe2
, raid_disks
);
2012 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2014 case ALGORITHM_PARITY_0
:
2018 case ALGORITHM_PARITY_N
:
2019 pd_idx
= data_disks
;
2027 switch (algorithm
) {
2028 case ALGORITHM_LEFT_ASYMMETRIC
:
2029 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2030 qd_idx
= pd_idx
+ 1;
2031 if (pd_idx
== raid_disks
-1) {
2032 (*dd_idx
)++; /* Q D D D P */
2034 } else if (*dd_idx
>= pd_idx
)
2035 (*dd_idx
) += 2; /* D D P Q D */
2037 case ALGORITHM_RIGHT_ASYMMETRIC
:
2038 pd_idx
= sector_div(stripe2
, raid_disks
);
2039 qd_idx
= pd_idx
+ 1;
2040 if (pd_idx
== raid_disks
-1) {
2041 (*dd_idx
)++; /* Q D D D P */
2043 } else if (*dd_idx
>= pd_idx
)
2044 (*dd_idx
) += 2; /* D D P Q D */
2046 case ALGORITHM_LEFT_SYMMETRIC
:
2047 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2048 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2049 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2051 case ALGORITHM_RIGHT_SYMMETRIC
:
2052 pd_idx
= sector_div(stripe2
, raid_disks
);
2053 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2054 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2057 case ALGORITHM_PARITY_0
:
2062 case ALGORITHM_PARITY_N
:
2063 pd_idx
= data_disks
;
2064 qd_idx
= data_disks
+ 1;
2067 case ALGORITHM_ROTATING_ZERO_RESTART
:
2068 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2069 * of blocks for computing Q is different.
2071 pd_idx
= sector_div(stripe2
, raid_disks
);
2072 qd_idx
= pd_idx
+ 1;
2073 if (pd_idx
== raid_disks
-1) {
2074 (*dd_idx
)++; /* Q D D D P */
2076 } else if (*dd_idx
>= pd_idx
)
2077 (*dd_idx
) += 2; /* D D P Q D */
2081 case ALGORITHM_ROTATING_N_RESTART
:
2082 /* Same a left_asymmetric, by first stripe is
2083 * D D D P Q rather than
2087 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2088 qd_idx
= pd_idx
+ 1;
2089 if (pd_idx
== raid_disks
-1) {
2090 (*dd_idx
)++; /* Q D D D P */
2092 } else if (*dd_idx
>= pd_idx
)
2093 (*dd_idx
) += 2; /* D D P Q D */
2097 case ALGORITHM_ROTATING_N_CONTINUE
:
2098 /* Same as left_symmetric but Q is before P */
2099 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2100 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2101 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2105 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2106 /* RAID5 left_asymmetric, with Q on last device */
2107 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2108 if (*dd_idx
>= pd_idx
)
2110 qd_idx
= raid_disks
- 1;
2113 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2114 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2115 if (*dd_idx
>= pd_idx
)
2117 qd_idx
= raid_disks
- 1;
2120 case ALGORITHM_LEFT_SYMMETRIC_6
:
2121 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2122 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2123 qd_idx
= raid_disks
- 1;
2126 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2127 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2128 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2129 qd_idx
= raid_disks
- 1;
2132 case ALGORITHM_PARITY_0_6
:
2135 qd_idx
= raid_disks
- 1;
2145 sh
->pd_idx
= pd_idx
;
2146 sh
->qd_idx
= qd_idx
;
2147 sh
->ddf_layout
= ddf_layout
;
2150 * Finally, compute the new sector number
2152 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2157 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2159 struct r5conf
*conf
= sh
->raid_conf
;
2160 int raid_disks
= sh
->disks
;
2161 int data_disks
= raid_disks
- conf
->max_degraded
;
2162 sector_t new_sector
= sh
->sector
, check
;
2163 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2164 : conf
->chunk_sectors
;
2165 int algorithm
= previous
? conf
->prev_algo
2169 sector_t chunk_number
;
2170 int dummy1
, dd_idx
= i
;
2172 struct stripe_head sh2
;
2175 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2176 stripe
= new_sector
;
2178 if (i
== sh
->pd_idx
)
2180 switch(conf
->level
) {
2183 switch (algorithm
) {
2184 case ALGORITHM_LEFT_ASYMMETRIC
:
2185 case ALGORITHM_RIGHT_ASYMMETRIC
:
2189 case ALGORITHM_LEFT_SYMMETRIC
:
2190 case ALGORITHM_RIGHT_SYMMETRIC
:
2193 i
-= (sh
->pd_idx
+ 1);
2195 case ALGORITHM_PARITY_0
:
2198 case ALGORITHM_PARITY_N
:
2205 if (i
== sh
->qd_idx
)
2206 return 0; /* It is the Q disk */
2207 switch (algorithm
) {
2208 case ALGORITHM_LEFT_ASYMMETRIC
:
2209 case ALGORITHM_RIGHT_ASYMMETRIC
:
2210 case ALGORITHM_ROTATING_ZERO_RESTART
:
2211 case ALGORITHM_ROTATING_N_RESTART
:
2212 if (sh
->pd_idx
== raid_disks
-1)
2213 i
--; /* Q D D D P */
2214 else if (i
> sh
->pd_idx
)
2215 i
-= 2; /* D D P Q D */
2217 case ALGORITHM_LEFT_SYMMETRIC
:
2218 case ALGORITHM_RIGHT_SYMMETRIC
:
2219 if (sh
->pd_idx
== raid_disks
-1)
2220 i
--; /* Q D D D P */
2225 i
-= (sh
->pd_idx
+ 2);
2228 case ALGORITHM_PARITY_0
:
2231 case ALGORITHM_PARITY_N
:
2233 case ALGORITHM_ROTATING_N_CONTINUE
:
2234 /* Like left_symmetric, but P is before Q */
2235 if (sh
->pd_idx
== 0)
2236 i
--; /* P D D D Q */
2241 i
-= (sh
->pd_idx
+ 1);
2244 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2245 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2249 case ALGORITHM_LEFT_SYMMETRIC_6
:
2250 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2252 i
+= data_disks
+ 1;
2253 i
-= (sh
->pd_idx
+ 1);
2255 case ALGORITHM_PARITY_0_6
:
2264 chunk_number
= stripe
* data_disks
+ i
;
2265 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2267 check
= raid5_compute_sector(conf
, r_sector
,
2268 previous
, &dummy1
, &sh2
);
2269 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2270 || sh2
.qd_idx
!= sh
->qd_idx
) {
2271 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2272 mdname(conf
->mddev
));
2280 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2281 int rcw
, int expand
)
2283 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2284 struct r5conf
*conf
= sh
->raid_conf
;
2285 int level
= conf
->level
;
2289 for (i
= disks
; i
--; ) {
2290 struct r5dev
*dev
= &sh
->dev
[i
];
2293 set_bit(R5_LOCKED
, &dev
->flags
);
2294 set_bit(R5_Wantdrain
, &dev
->flags
);
2296 clear_bit(R5_UPTODATE
, &dev
->flags
);
2300 /* if we are not expanding this is a proper write request, and
2301 * there will be bios with new data to be drained into the
2306 /* False alarm, nothing to do */
2308 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2309 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2311 sh
->reconstruct_state
= reconstruct_state_run
;
2313 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2315 if (s
->locked
+ conf
->max_degraded
== disks
)
2316 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2317 atomic_inc(&conf
->pending_full_writes
);
2320 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2321 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2323 for (i
= disks
; i
--; ) {
2324 struct r5dev
*dev
= &sh
->dev
[i
];
2329 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2330 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2331 set_bit(R5_Wantdrain
, &dev
->flags
);
2332 set_bit(R5_LOCKED
, &dev
->flags
);
2333 clear_bit(R5_UPTODATE
, &dev
->flags
);
2338 /* False alarm - nothing to do */
2340 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2341 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2342 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2343 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2346 /* keep the parity disk(s) locked while asynchronous operations
2349 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2350 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2354 int qd_idx
= sh
->qd_idx
;
2355 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2357 set_bit(R5_LOCKED
, &dev
->flags
);
2358 clear_bit(R5_UPTODATE
, &dev
->flags
);
2362 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2363 __func__
, (unsigned long long)sh
->sector
,
2364 s
->locked
, s
->ops_request
);
2368 * Each stripe/dev can have one or more bion attached.
2369 * toread/towrite point to the first in a chain.
2370 * The bi_next chain must be in order.
2372 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2375 struct r5conf
*conf
= sh
->raid_conf
;
2378 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2379 (unsigned long long)bi
->bi_sector
,
2380 (unsigned long long)sh
->sector
);
2383 * If several bio share a stripe. The bio bi_phys_segments acts as a
2384 * reference count to avoid race. The reference count should already be
2385 * increased before this function is called (for example, in
2386 * make_request()), so other bio sharing this stripe will not free the
2387 * stripe. If a stripe is owned by one stripe, the stripe lock will
2390 spin_lock_irq(&sh
->stripe_lock
);
2392 bip
= &sh
->dev
[dd_idx
].towrite
;
2396 bip
= &sh
->dev
[dd_idx
].toread
;
2397 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2398 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2400 bip
= & (*bip
)->bi_next
;
2402 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2405 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2409 raid5_inc_bi_active_stripes(bi
);
2412 /* check if page is covered */
2413 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2414 for (bi
=sh
->dev
[dd_idx
].towrite
;
2415 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2416 bi
&& bi
->bi_sector
<= sector
;
2417 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2418 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2419 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2421 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2422 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2425 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2426 (unsigned long long)(*bip
)->bi_sector
,
2427 (unsigned long long)sh
->sector
, dd_idx
);
2428 spin_unlock_irq(&sh
->stripe_lock
);
2430 if (conf
->mddev
->bitmap
&& firstwrite
) {
2431 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2433 sh
->bm_seq
= conf
->seq_flush
+1;
2434 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2439 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2440 spin_unlock_irq(&sh
->stripe_lock
);
2444 static void end_reshape(struct r5conf
*conf
);
2446 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2447 struct stripe_head
*sh
)
2449 int sectors_per_chunk
=
2450 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2452 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2453 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2455 raid5_compute_sector(conf
,
2456 stripe
* (disks
- conf
->max_degraded
)
2457 *sectors_per_chunk
+ chunk_offset
,
2463 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2464 struct stripe_head_state
*s
, int disks
,
2465 struct bio
**return_bi
)
2468 for (i
= disks
; i
--; ) {
2472 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2473 struct md_rdev
*rdev
;
2475 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2476 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2477 atomic_inc(&rdev
->nr_pending
);
2482 if (!rdev_set_badblocks(
2486 md_error(conf
->mddev
, rdev
);
2487 rdev_dec_pending(rdev
, conf
->mddev
);
2490 spin_lock_irq(&sh
->stripe_lock
);
2491 /* fail all writes first */
2492 bi
= sh
->dev
[i
].towrite
;
2493 sh
->dev
[i
].towrite
= NULL
;
2494 spin_unlock_irq(&sh
->stripe_lock
);
2498 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2499 wake_up(&conf
->wait_for_overlap
);
2501 while (bi
&& bi
->bi_sector
<
2502 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2503 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2504 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2505 if (!raid5_dec_bi_active_stripes(bi
)) {
2506 md_write_end(conf
->mddev
);
2507 bi
->bi_next
= *return_bi
;
2513 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2514 STRIPE_SECTORS
, 0, 0);
2516 /* and fail all 'written' */
2517 bi
= sh
->dev
[i
].written
;
2518 sh
->dev
[i
].written
= NULL
;
2519 if (bi
) bitmap_end
= 1;
2520 while (bi
&& bi
->bi_sector
<
2521 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2522 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2523 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2524 if (!raid5_dec_bi_active_stripes(bi
)) {
2525 md_write_end(conf
->mddev
);
2526 bi
->bi_next
= *return_bi
;
2532 /* fail any reads if this device is non-operational and
2533 * the data has not reached the cache yet.
2535 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2536 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2537 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2538 spin_lock_irq(&sh
->stripe_lock
);
2539 bi
= sh
->dev
[i
].toread
;
2540 sh
->dev
[i
].toread
= NULL
;
2541 spin_unlock_irq(&sh
->stripe_lock
);
2542 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2543 wake_up(&conf
->wait_for_overlap
);
2544 while (bi
&& bi
->bi_sector
<
2545 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2546 struct bio
*nextbi
=
2547 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2548 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2549 if (!raid5_dec_bi_active_stripes(bi
)) {
2550 bi
->bi_next
= *return_bi
;
2557 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2558 STRIPE_SECTORS
, 0, 0);
2559 /* If we were in the middle of a write the parity block might
2560 * still be locked - so just clear all R5_LOCKED flags
2562 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2565 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2566 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2567 md_wakeup_thread(conf
->mddev
->thread
);
2571 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2572 struct stripe_head_state
*s
)
2577 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2578 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
2579 wake_up(&conf
->wait_for_overlap
);
2582 /* There is nothing more to do for sync/check/repair.
2583 * Don't even need to abort as that is handled elsewhere
2584 * if needed, and not always wanted e.g. if there is a known
2586 * For recover/replace we need to record a bad block on all
2587 * non-sync devices, or abort the recovery
2589 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2590 /* During recovery devices cannot be removed, so
2591 * locking and refcounting of rdevs is not needed
2593 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2594 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2596 && !test_bit(Faulty
, &rdev
->flags
)
2597 && !test_bit(In_sync
, &rdev
->flags
)
2598 && !rdev_set_badblocks(rdev
, sh
->sector
,
2601 rdev
= conf
->disks
[i
].replacement
;
2603 && !test_bit(Faulty
, &rdev
->flags
)
2604 && !test_bit(In_sync
, &rdev
->flags
)
2605 && !rdev_set_badblocks(rdev
, sh
->sector
,
2610 conf
->recovery_disabled
=
2611 conf
->mddev
->recovery_disabled
;
2613 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2616 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2618 struct md_rdev
*rdev
;
2620 /* Doing recovery so rcu locking not required */
2621 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2623 && !test_bit(Faulty
, &rdev
->flags
)
2624 && !test_bit(In_sync
, &rdev
->flags
)
2625 && (rdev
->recovery_offset
<= sh
->sector
2626 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2632 /* fetch_block - checks the given member device to see if its data needs
2633 * to be read or computed to satisfy a request.
2635 * Returns 1 when no more member devices need to be checked, otherwise returns
2636 * 0 to tell the loop in handle_stripe_fill to continue
2638 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2639 int disk_idx
, int disks
)
2641 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2642 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2643 &sh
->dev
[s
->failed_num
[1]] };
2645 /* is the data in this block needed, and can we get it? */
2646 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2647 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2649 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2650 s
->syncing
|| s
->expanding
||
2651 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2652 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2653 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2654 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2655 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2656 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2657 /* we would like to get this block, possibly by computing it,
2658 * otherwise read it if the backing disk is insync
2660 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2661 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2662 if ((s
->uptodate
== disks
- 1) &&
2663 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2664 disk_idx
== s
->failed_num
[1]))) {
2665 /* have disk failed, and we're requested to fetch it;
2668 pr_debug("Computing stripe %llu block %d\n",
2669 (unsigned long long)sh
->sector
, disk_idx
);
2670 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2671 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2672 set_bit(R5_Wantcompute
, &dev
->flags
);
2673 sh
->ops
.target
= disk_idx
;
2674 sh
->ops
.target2
= -1; /* no 2nd target */
2676 /* Careful: from this point on 'uptodate' is in the eye
2677 * of raid_run_ops which services 'compute' operations
2678 * before writes. R5_Wantcompute flags a block that will
2679 * be R5_UPTODATE by the time it is needed for a
2680 * subsequent operation.
2684 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2685 /* Computing 2-failure is *very* expensive; only
2686 * do it if failed >= 2
2689 for (other
= disks
; other
--; ) {
2690 if (other
== disk_idx
)
2692 if (!test_bit(R5_UPTODATE
,
2693 &sh
->dev
[other
].flags
))
2697 pr_debug("Computing stripe %llu blocks %d,%d\n",
2698 (unsigned long long)sh
->sector
,
2700 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2701 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2702 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2703 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2704 sh
->ops
.target
= disk_idx
;
2705 sh
->ops
.target2
= other
;
2709 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2710 set_bit(R5_LOCKED
, &dev
->flags
);
2711 set_bit(R5_Wantread
, &dev
->flags
);
2713 pr_debug("Reading block %d (sync=%d)\n",
2714 disk_idx
, s
->syncing
);
2722 * handle_stripe_fill - read or compute data to satisfy pending requests.
2724 static void handle_stripe_fill(struct stripe_head
*sh
,
2725 struct stripe_head_state
*s
,
2730 /* look for blocks to read/compute, skip this if a compute
2731 * is already in flight, or if the stripe contents are in the
2732 * midst of changing due to a write
2734 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2735 !sh
->reconstruct_state
)
2736 for (i
= disks
; i
--; )
2737 if (fetch_block(sh
, s
, i
, disks
))
2739 set_bit(STRIPE_HANDLE
, &sh
->state
);
2743 /* handle_stripe_clean_event
2744 * any written block on an uptodate or failed drive can be returned.
2745 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2746 * never LOCKED, so we don't need to test 'failed' directly.
2748 static void handle_stripe_clean_event(struct r5conf
*conf
,
2749 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2753 int discard_pending
= 0;
2755 for (i
= disks
; i
--; )
2756 if (sh
->dev
[i
].written
) {
2758 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2759 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2760 test_bit(R5_Discard
, &dev
->flags
))) {
2761 /* We can return any write requests */
2762 struct bio
*wbi
, *wbi2
;
2763 pr_debug("Return write for disc %d\n", i
);
2764 if (test_and_clear_bit(R5_Discard
, &dev
->flags
))
2765 clear_bit(R5_UPTODATE
, &dev
->flags
);
2767 dev
->written
= NULL
;
2768 while (wbi
&& wbi
->bi_sector
<
2769 dev
->sector
+ STRIPE_SECTORS
) {
2770 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2771 if (!raid5_dec_bi_active_stripes(wbi
)) {
2772 md_write_end(conf
->mddev
);
2773 wbi
->bi_next
= *return_bi
;
2778 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2780 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2782 } else if (test_bit(R5_Discard
, &dev
->flags
))
2783 discard_pending
= 1;
2785 if (!discard_pending
&&
2786 test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
)) {
2787 clear_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
2788 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2789 if (sh
->qd_idx
>= 0) {
2790 clear_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
2791 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
);
2793 /* now that discard is done we can proceed with any sync */
2794 clear_bit(STRIPE_DISCARD
, &sh
->state
);
2795 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
))
2796 set_bit(STRIPE_HANDLE
, &sh
->state
);
2800 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2801 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2802 md_wakeup_thread(conf
->mddev
->thread
);
2805 static void handle_stripe_dirtying(struct r5conf
*conf
,
2806 struct stripe_head
*sh
,
2807 struct stripe_head_state
*s
,
2810 int rmw
= 0, rcw
= 0, i
;
2811 sector_t recovery_cp
= conf
->mddev
->recovery_cp
;
2813 /* RAID6 requires 'rcw' in current implementation.
2814 * Otherwise, check whether resync is now happening or should start.
2815 * If yes, then the array is dirty (after unclean shutdown or
2816 * initial creation), so parity in some stripes might be inconsistent.
2817 * In this case, we need to always do reconstruct-write, to ensure
2818 * that in case of drive failure or read-error correction, we
2819 * generate correct data from the parity.
2821 if (conf
->max_degraded
== 2 ||
2822 (recovery_cp
< MaxSector
&& sh
->sector
>= recovery_cp
)) {
2823 /* Calculate the real rcw later - for now make it
2824 * look like rcw is cheaper
2827 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2828 conf
->max_degraded
, (unsigned long long)recovery_cp
,
2829 (unsigned long long)sh
->sector
);
2830 } else for (i
= disks
; i
--; ) {
2831 /* would I have to read this buffer for read_modify_write */
2832 struct r5dev
*dev
= &sh
->dev
[i
];
2833 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2834 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2835 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2836 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2837 if (test_bit(R5_Insync
, &dev
->flags
))
2840 rmw
+= 2*disks
; /* cannot read it */
2842 /* Would I have to read this buffer for reconstruct_write */
2843 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2844 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2845 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2846 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2847 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2852 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2853 (unsigned long long)sh
->sector
, rmw
, rcw
);
2854 set_bit(STRIPE_HANDLE
, &sh
->state
);
2855 if (rmw
< rcw
&& rmw
> 0) {
2856 /* prefer read-modify-write, but need to get some data */
2857 if (conf
->mddev
->queue
)
2858 blk_add_trace_msg(conf
->mddev
->queue
,
2859 "raid5 rmw %llu %d",
2860 (unsigned long long)sh
->sector
, rmw
);
2861 for (i
= disks
; i
--; ) {
2862 struct r5dev
*dev
= &sh
->dev
[i
];
2863 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2864 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2865 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2866 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2867 test_bit(R5_Insync
, &dev
->flags
)) {
2869 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2870 pr_debug("Read_old block "
2871 "%d for r-m-w\n", i
);
2872 set_bit(R5_LOCKED
, &dev
->flags
);
2873 set_bit(R5_Wantread
, &dev
->flags
);
2876 set_bit(STRIPE_DELAYED
, &sh
->state
);
2877 set_bit(STRIPE_HANDLE
, &sh
->state
);
2882 if (rcw
<= rmw
&& rcw
> 0) {
2883 /* want reconstruct write, but need to get some data */
2886 for (i
= disks
; i
--; ) {
2887 struct r5dev
*dev
= &sh
->dev
[i
];
2888 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2889 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2890 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2891 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2892 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2894 if (!test_bit(R5_Insync
, &dev
->flags
))
2895 continue; /* it's a failed drive */
2897 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2898 pr_debug("Read_old block "
2899 "%d for Reconstruct\n", i
);
2900 set_bit(R5_LOCKED
, &dev
->flags
);
2901 set_bit(R5_Wantread
, &dev
->flags
);
2905 set_bit(STRIPE_DELAYED
, &sh
->state
);
2906 set_bit(STRIPE_HANDLE
, &sh
->state
);
2910 if (rcw
&& conf
->mddev
->queue
)
2911 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rcw %llu %d %d %d",
2912 (unsigned long long)sh
->sector
,
2913 rcw
, qread
, test_bit(STRIPE_DELAYED
, &sh
->state
));
2915 /* now if nothing is locked, and if we have enough data,
2916 * we can start a write request
2918 /* since handle_stripe can be called at any time we need to handle the
2919 * case where a compute block operation has been submitted and then a
2920 * subsequent call wants to start a write request. raid_run_ops only
2921 * handles the case where compute block and reconstruct are requested
2922 * simultaneously. If this is not the case then new writes need to be
2923 * held off until the compute completes.
2925 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2926 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2927 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2928 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2931 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2932 struct stripe_head_state
*s
, int disks
)
2934 struct r5dev
*dev
= NULL
;
2936 set_bit(STRIPE_HANDLE
, &sh
->state
);
2938 switch (sh
->check_state
) {
2939 case check_state_idle
:
2940 /* start a new check operation if there are no failures */
2941 if (s
->failed
== 0) {
2942 BUG_ON(s
->uptodate
!= disks
);
2943 sh
->check_state
= check_state_run
;
2944 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2945 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2949 dev
= &sh
->dev
[s
->failed_num
[0]];
2951 case check_state_compute_result
:
2952 sh
->check_state
= check_state_idle
;
2954 dev
= &sh
->dev
[sh
->pd_idx
];
2956 /* check that a write has not made the stripe insync */
2957 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2960 /* either failed parity check, or recovery is happening */
2961 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2962 BUG_ON(s
->uptodate
!= disks
);
2964 set_bit(R5_LOCKED
, &dev
->flags
);
2966 set_bit(R5_Wantwrite
, &dev
->flags
);
2968 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2969 set_bit(STRIPE_INSYNC
, &sh
->state
);
2971 case check_state_run
:
2972 break; /* we will be called again upon completion */
2973 case check_state_check_result
:
2974 sh
->check_state
= check_state_idle
;
2976 /* if a failure occurred during the check operation, leave
2977 * STRIPE_INSYNC not set and let the stripe be handled again
2982 /* handle a successful check operation, if parity is correct
2983 * we are done. Otherwise update the mismatch count and repair
2984 * parity if !MD_RECOVERY_CHECK
2986 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2987 /* parity is correct (on disc,
2988 * not in buffer any more)
2990 set_bit(STRIPE_INSYNC
, &sh
->state
);
2992 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
2993 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2994 /* don't try to repair!! */
2995 set_bit(STRIPE_INSYNC
, &sh
->state
);
2997 sh
->check_state
= check_state_compute_run
;
2998 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2999 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3000 set_bit(R5_Wantcompute
,
3001 &sh
->dev
[sh
->pd_idx
].flags
);
3002 sh
->ops
.target
= sh
->pd_idx
;
3003 sh
->ops
.target2
= -1;
3008 case check_state_compute_run
:
3011 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3012 __func__
, sh
->check_state
,
3013 (unsigned long long) sh
->sector
);
3019 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
3020 struct stripe_head_state
*s
,
3023 int pd_idx
= sh
->pd_idx
;
3024 int qd_idx
= sh
->qd_idx
;
3027 set_bit(STRIPE_HANDLE
, &sh
->state
);
3029 BUG_ON(s
->failed
> 2);
3031 /* Want to check and possibly repair P and Q.
3032 * However there could be one 'failed' device, in which
3033 * case we can only check one of them, possibly using the
3034 * other to generate missing data
3037 switch (sh
->check_state
) {
3038 case check_state_idle
:
3039 /* start a new check operation if there are < 2 failures */
3040 if (s
->failed
== s
->q_failed
) {
3041 /* The only possible failed device holds Q, so it
3042 * makes sense to check P (If anything else were failed,
3043 * we would have used P to recreate it).
3045 sh
->check_state
= check_state_run
;
3047 if (!s
->q_failed
&& s
->failed
< 2) {
3048 /* Q is not failed, and we didn't use it to generate
3049 * anything, so it makes sense to check it
3051 if (sh
->check_state
== check_state_run
)
3052 sh
->check_state
= check_state_run_pq
;
3054 sh
->check_state
= check_state_run_q
;
3057 /* discard potentially stale zero_sum_result */
3058 sh
->ops
.zero_sum_result
= 0;
3060 if (sh
->check_state
== check_state_run
) {
3061 /* async_xor_zero_sum destroys the contents of P */
3062 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3065 if (sh
->check_state
>= check_state_run
&&
3066 sh
->check_state
<= check_state_run_pq
) {
3067 /* async_syndrome_zero_sum preserves P and Q, so
3068 * no need to mark them !uptodate here
3070 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3074 /* we have 2-disk failure */
3075 BUG_ON(s
->failed
!= 2);
3077 case check_state_compute_result
:
3078 sh
->check_state
= check_state_idle
;
3080 /* check that a write has not made the stripe insync */
3081 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3084 /* now write out any block on a failed drive,
3085 * or P or Q if they were recomputed
3087 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3088 if (s
->failed
== 2) {
3089 dev
= &sh
->dev
[s
->failed_num
[1]];
3091 set_bit(R5_LOCKED
, &dev
->flags
);
3092 set_bit(R5_Wantwrite
, &dev
->flags
);
3094 if (s
->failed
>= 1) {
3095 dev
= &sh
->dev
[s
->failed_num
[0]];
3097 set_bit(R5_LOCKED
, &dev
->flags
);
3098 set_bit(R5_Wantwrite
, &dev
->flags
);
3100 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3101 dev
= &sh
->dev
[pd_idx
];
3103 set_bit(R5_LOCKED
, &dev
->flags
);
3104 set_bit(R5_Wantwrite
, &dev
->flags
);
3106 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3107 dev
= &sh
->dev
[qd_idx
];
3109 set_bit(R5_LOCKED
, &dev
->flags
);
3110 set_bit(R5_Wantwrite
, &dev
->flags
);
3112 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3114 set_bit(STRIPE_INSYNC
, &sh
->state
);
3116 case check_state_run
:
3117 case check_state_run_q
:
3118 case check_state_run_pq
:
3119 break; /* we will be called again upon completion */
3120 case check_state_check_result
:
3121 sh
->check_state
= check_state_idle
;
3123 /* handle a successful check operation, if parity is correct
3124 * we are done. Otherwise update the mismatch count and repair
3125 * parity if !MD_RECOVERY_CHECK
3127 if (sh
->ops
.zero_sum_result
== 0) {
3128 /* both parities are correct */
3130 set_bit(STRIPE_INSYNC
, &sh
->state
);
3132 /* in contrast to the raid5 case we can validate
3133 * parity, but still have a failure to write
3136 sh
->check_state
= check_state_compute_result
;
3137 /* Returning at this point means that we may go
3138 * off and bring p and/or q uptodate again so
3139 * we make sure to check zero_sum_result again
3140 * to verify if p or q need writeback
3144 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3145 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3146 /* don't try to repair!! */
3147 set_bit(STRIPE_INSYNC
, &sh
->state
);
3149 int *target
= &sh
->ops
.target
;
3151 sh
->ops
.target
= -1;
3152 sh
->ops
.target2
= -1;
3153 sh
->check_state
= check_state_compute_run
;
3154 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3155 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3156 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3157 set_bit(R5_Wantcompute
,
3158 &sh
->dev
[pd_idx
].flags
);
3160 target
= &sh
->ops
.target2
;
3163 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3164 set_bit(R5_Wantcompute
,
3165 &sh
->dev
[qd_idx
].flags
);
3172 case check_state_compute_run
:
3175 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3176 __func__
, sh
->check_state
,
3177 (unsigned long long) sh
->sector
);
3182 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3186 /* We have read all the blocks in this stripe and now we need to
3187 * copy some of them into a target stripe for expand.
3189 struct dma_async_tx_descriptor
*tx
= NULL
;
3190 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3191 for (i
= 0; i
< sh
->disks
; i
++)
3192 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3194 struct stripe_head
*sh2
;
3195 struct async_submit_ctl submit
;
3197 sector_t bn
= compute_blocknr(sh
, i
, 1);
3198 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3200 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3202 /* so far only the early blocks of this stripe
3203 * have been requested. When later blocks
3204 * get requested, we will try again
3207 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3208 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3209 /* must have already done this block */
3210 release_stripe(sh2
);
3214 /* place all the copies on one channel */
3215 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3216 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3217 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3220 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3221 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3222 for (j
= 0; j
< conf
->raid_disks
; j
++)
3223 if (j
!= sh2
->pd_idx
&&
3225 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3227 if (j
== conf
->raid_disks
) {
3228 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3229 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3231 release_stripe(sh2
);
3234 /* done submitting copies, wait for them to complete */
3235 async_tx_quiesce(&tx
);
3239 * handle_stripe - do things to a stripe.
3241 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3242 * state of various bits to see what needs to be done.
3244 * return some read requests which now have data
3245 * return some write requests which are safely on storage
3246 * schedule a read on some buffers
3247 * schedule a write of some buffers
3248 * return confirmation of parity correctness
3252 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3254 struct r5conf
*conf
= sh
->raid_conf
;
3255 int disks
= sh
->disks
;
3258 int do_recovery
= 0;
3260 memset(s
, 0, sizeof(*s
));
3262 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3263 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3264 s
->failed_num
[0] = -1;
3265 s
->failed_num
[1] = -1;
3267 /* Now to look around and see what can be done */
3269 for (i
=disks
; i
--; ) {
3270 struct md_rdev
*rdev
;
3277 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3279 dev
->toread
, dev
->towrite
, dev
->written
);
3280 /* maybe we can reply to a read
3282 * new wantfill requests are only permitted while
3283 * ops_complete_biofill is guaranteed to be inactive
3285 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3286 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3287 set_bit(R5_Wantfill
, &dev
->flags
);
3289 /* now count some things */
3290 if (test_bit(R5_LOCKED
, &dev
->flags
))
3292 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3294 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3296 BUG_ON(s
->compute
> 2);
3299 if (test_bit(R5_Wantfill
, &dev
->flags
))
3301 else if (dev
->toread
)
3305 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3310 /* Prefer to use the replacement for reads, but only
3311 * if it is recovered enough and has no bad blocks.
3313 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3314 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3315 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3316 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3317 &first_bad
, &bad_sectors
))
3318 set_bit(R5_ReadRepl
, &dev
->flags
);
3321 set_bit(R5_NeedReplace
, &dev
->flags
);
3322 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3323 clear_bit(R5_ReadRepl
, &dev
->flags
);
3325 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3328 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3329 &first_bad
, &bad_sectors
);
3330 if (s
->blocked_rdev
== NULL
3331 && (test_bit(Blocked
, &rdev
->flags
)
3334 set_bit(BlockedBadBlocks
,
3336 s
->blocked_rdev
= rdev
;
3337 atomic_inc(&rdev
->nr_pending
);
3340 clear_bit(R5_Insync
, &dev
->flags
);
3344 /* also not in-sync */
3345 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3346 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3347 /* treat as in-sync, but with a read error
3348 * which we can now try to correct
3350 set_bit(R5_Insync
, &dev
->flags
);
3351 set_bit(R5_ReadError
, &dev
->flags
);
3353 } else if (test_bit(In_sync
, &rdev
->flags
))
3354 set_bit(R5_Insync
, &dev
->flags
);
3355 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3356 /* in sync if before recovery_offset */
3357 set_bit(R5_Insync
, &dev
->flags
);
3358 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3359 test_bit(R5_Expanded
, &dev
->flags
))
3360 /* If we've reshaped into here, we assume it is Insync.
3361 * We will shortly update recovery_offset to make
3364 set_bit(R5_Insync
, &dev
->flags
);
3366 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3367 /* This flag does not apply to '.replacement'
3368 * only to .rdev, so make sure to check that*/
3369 struct md_rdev
*rdev2
= rcu_dereference(
3370 conf
->disks
[i
].rdev
);
3372 clear_bit(R5_Insync
, &dev
->flags
);
3373 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3374 s
->handle_bad_blocks
= 1;
3375 atomic_inc(&rdev2
->nr_pending
);
3377 clear_bit(R5_WriteError
, &dev
->flags
);
3379 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3380 /* This flag does not apply to '.replacement'
3381 * only to .rdev, so make sure to check that*/
3382 struct md_rdev
*rdev2
= rcu_dereference(
3383 conf
->disks
[i
].rdev
);
3384 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3385 s
->handle_bad_blocks
= 1;
3386 atomic_inc(&rdev2
->nr_pending
);
3388 clear_bit(R5_MadeGood
, &dev
->flags
);
3390 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3391 struct md_rdev
*rdev2
= rcu_dereference(
3392 conf
->disks
[i
].replacement
);
3393 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3394 s
->handle_bad_blocks
= 1;
3395 atomic_inc(&rdev2
->nr_pending
);
3397 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3399 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3400 /* The ReadError flag will just be confusing now */
3401 clear_bit(R5_ReadError
, &dev
->flags
);
3402 clear_bit(R5_ReWrite
, &dev
->flags
);
3404 if (test_bit(R5_ReadError
, &dev
->flags
))
3405 clear_bit(R5_Insync
, &dev
->flags
);
3406 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3408 s
->failed_num
[s
->failed
] = i
;
3410 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3414 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3415 /* If there is a failed device being replaced,
3416 * we must be recovering.
3417 * else if we are after recovery_cp, we must be syncing
3418 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3419 * else we can only be replacing
3420 * sync and recovery both need to read all devices, and so
3421 * use the same flag.
3424 sh
->sector
>= conf
->mddev
->recovery_cp
||
3425 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3433 static void handle_stripe(struct stripe_head
*sh
)
3435 struct stripe_head_state s
;
3436 struct r5conf
*conf
= sh
->raid_conf
;
3439 int disks
= sh
->disks
;
3440 struct r5dev
*pdev
, *qdev
;
3442 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3443 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3444 /* already being handled, ensure it gets handled
3445 * again when current action finishes */
3446 set_bit(STRIPE_HANDLE
, &sh
->state
);
3450 if (test_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3451 spin_lock(&sh
->stripe_lock
);
3452 /* Cannot process 'sync' concurrently with 'discard' */
3453 if (!test_bit(STRIPE_DISCARD
, &sh
->state
) &&
3454 test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3455 set_bit(STRIPE_SYNCING
, &sh
->state
);
3456 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3458 spin_unlock(&sh
->stripe_lock
);
3460 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3462 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3463 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3464 (unsigned long long)sh
->sector
, sh
->state
,
3465 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3466 sh
->check_state
, sh
->reconstruct_state
);
3468 analyse_stripe(sh
, &s
);
3470 if (s
.handle_bad_blocks
) {
3471 set_bit(STRIPE_HANDLE
, &sh
->state
);
3475 if (unlikely(s
.blocked_rdev
)) {
3476 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3477 s
.replacing
|| s
.to_write
|| s
.written
) {
3478 set_bit(STRIPE_HANDLE
, &sh
->state
);
3481 /* There is nothing for the blocked_rdev to block */
3482 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3483 s
.blocked_rdev
= NULL
;
3486 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3487 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3488 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3491 pr_debug("locked=%d uptodate=%d to_read=%d"
3492 " to_write=%d failed=%d failed_num=%d,%d\n",
3493 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3494 s
.failed_num
[0], s
.failed_num
[1]);
3495 /* check if the array has lost more than max_degraded devices and,
3496 * if so, some requests might need to be failed.
3498 if (s
.failed
> conf
->max_degraded
) {
3499 sh
->check_state
= 0;
3500 sh
->reconstruct_state
= 0;
3501 if (s
.to_read
+s
.to_write
+s
.written
)
3502 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3503 if (s
.syncing
+ s
.replacing
)
3504 handle_failed_sync(conf
, sh
, &s
);
3507 /* Now we check to see if any write operations have recently
3511 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3513 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3514 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3515 sh
->reconstruct_state
= reconstruct_state_idle
;
3517 /* All the 'written' buffers and the parity block are ready to
3518 * be written back to disk
3520 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
) &&
3521 !test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
));
3522 BUG_ON(sh
->qd_idx
>= 0 &&
3523 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
) &&
3524 !test_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
));
3525 for (i
= disks
; i
--; ) {
3526 struct r5dev
*dev
= &sh
->dev
[i
];
3527 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3528 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3530 pr_debug("Writing block %d\n", i
);
3531 set_bit(R5_Wantwrite
, &dev
->flags
);
3534 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3535 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3537 set_bit(STRIPE_INSYNC
, &sh
->state
);
3540 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3541 s
.dec_preread_active
= 1;
3545 * might be able to return some write requests if the parity blocks
3546 * are safe, or on a failed drive
3548 pdev
= &sh
->dev
[sh
->pd_idx
];
3549 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3550 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3551 qdev
= &sh
->dev
[sh
->qd_idx
];
3552 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3553 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3557 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3558 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3559 && (test_bit(R5_UPTODATE
, &pdev
->flags
) ||
3560 test_bit(R5_Discard
, &pdev
->flags
))))) &&
3561 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3562 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3563 && (test_bit(R5_UPTODATE
, &qdev
->flags
) ||
3564 test_bit(R5_Discard
, &qdev
->flags
))))))
3565 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3567 /* Now we might consider reading some blocks, either to check/generate
3568 * parity, or to satisfy requests
3569 * or to load a block that is being partially written.
3571 if (s
.to_read
|| s
.non_overwrite
3572 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3573 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3576 handle_stripe_fill(sh
, &s
, disks
);
3578 /* Now to consider new write requests and what else, if anything
3579 * should be read. We do not handle new writes when:
3580 * 1/ A 'write' operation (copy+xor) is already in flight.
3581 * 2/ A 'check' operation is in flight, as it may clobber the parity
3584 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3585 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3587 /* maybe we need to check and possibly fix the parity for this stripe
3588 * Any reads will already have been scheduled, so we just see if enough
3589 * data is available. The parity check is held off while parity
3590 * dependent operations are in flight.
3592 if (sh
->check_state
||
3593 (s
.syncing
&& s
.locked
== 0 &&
3594 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3595 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3596 if (conf
->level
== 6)
3597 handle_parity_checks6(conf
, sh
, &s
, disks
);
3599 handle_parity_checks5(conf
, sh
, &s
, disks
);
3602 if (s
.replacing
&& s
.locked
== 0
3603 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3604 /* Write out to replacement devices where possible */
3605 for (i
= 0; i
< conf
->raid_disks
; i
++)
3606 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3607 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3608 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3609 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3612 set_bit(STRIPE_INSYNC
, &sh
->state
);
3614 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3615 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3616 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3617 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3618 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
))
3619 wake_up(&conf
->wait_for_overlap
);
3622 /* If the failed drives are just a ReadError, then we might need
3623 * to progress the repair/check process
3625 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3626 for (i
= 0; i
< s
.failed
; i
++) {
3627 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3628 if (test_bit(R5_ReadError
, &dev
->flags
)
3629 && !test_bit(R5_LOCKED
, &dev
->flags
)
3630 && test_bit(R5_UPTODATE
, &dev
->flags
)
3632 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3633 set_bit(R5_Wantwrite
, &dev
->flags
);
3634 set_bit(R5_ReWrite
, &dev
->flags
);
3635 set_bit(R5_LOCKED
, &dev
->flags
);
3638 /* let's read it back */
3639 set_bit(R5_Wantread
, &dev
->flags
);
3640 set_bit(R5_LOCKED
, &dev
->flags
);
3647 /* Finish reconstruct operations initiated by the expansion process */
3648 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3649 struct stripe_head
*sh_src
3650 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3651 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3652 /* sh cannot be written until sh_src has been read.
3653 * so arrange for sh to be delayed a little
3655 set_bit(STRIPE_DELAYED
, &sh
->state
);
3656 set_bit(STRIPE_HANDLE
, &sh
->state
);
3657 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3659 atomic_inc(&conf
->preread_active_stripes
);
3660 release_stripe(sh_src
);
3664 release_stripe(sh_src
);
3666 sh
->reconstruct_state
= reconstruct_state_idle
;
3667 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3668 for (i
= conf
->raid_disks
; i
--; ) {
3669 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3670 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3675 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3676 !sh
->reconstruct_state
) {
3677 /* Need to write out all blocks after computing parity */
3678 sh
->disks
= conf
->raid_disks
;
3679 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3680 schedule_reconstruction(sh
, &s
, 1, 1);
3681 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3682 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3683 atomic_dec(&conf
->reshape_stripes
);
3684 wake_up(&conf
->wait_for_overlap
);
3685 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3688 if (s
.expanding
&& s
.locked
== 0 &&
3689 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3690 handle_stripe_expansion(conf
, sh
);
3693 /* wait for this device to become unblocked */
3694 if (unlikely(s
.blocked_rdev
)) {
3695 if (conf
->mddev
->external
)
3696 md_wait_for_blocked_rdev(s
.blocked_rdev
,
3699 /* Internal metadata will immediately
3700 * be written by raid5d, so we don't
3701 * need to wait here.
3703 rdev_dec_pending(s
.blocked_rdev
,
3707 if (s
.handle_bad_blocks
)
3708 for (i
= disks
; i
--; ) {
3709 struct md_rdev
*rdev
;
3710 struct r5dev
*dev
= &sh
->dev
[i
];
3711 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3712 /* We own a safe reference to the rdev */
3713 rdev
= conf
->disks
[i
].rdev
;
3714 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3716 md_error(conf
->mddev
, rdev
);
3717 rdev_dec_pending(rdev
, conf
->mddev
);
3719 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3720 rdev
= conf
->disks
[i
].rdev
;
3721 rdev_clear_badblocks(rdev
, sh
->sector
,
3723 rdev_dec_pending(rdev
, conf
->mddev
);
3725 if (test_and_clear_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3726 rdev
= conf
->disks
[i
].replacement
;
3728 /* rdev have been moved down */
3729 rdev
= conf
->disks
[i
].rdev
;
3730 rdev_clear_badblocks(rdev
, sh
->sector
,
3732 rdev_dec_pending(rdev
, conf
->mddev
);
3737 raid_run_ops(sh
, s
.ops_request
);
3741 if (s
.dec_preread_active
) {
3742 /* We delay this until after ops_run_io so that if make_request
3743 * is waiting on a flush, it won't continue until the writes
3744 * have actually been submitted.
3746 atomic_dec(&conf
->preread_active_stripes
);
3747 if (atomic_read(&conf
->preread_active_stripes
) <
3749 md_wakeup_thread(conf
->mddev
->thread
);
3752 return_io(s
.return_bi
);
3754 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3757 static void raid5_activate_delayed(struct r5conf
*conf
)
3759 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3760 while (!list_empty(&conf
->delayed_list
)) {
3761 struct list_head
*l
= conf
->delayed_list
.next
;
3762 struct stripe_head
*sh
;
3763 sh
= list_entry(l
, struct stripe_head
, lru
);
3765 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3766 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3767 atomic_inc(&conf
->preread_active_stripes
);
3768 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3773 static void activate_bit_delay(struct r5conf
*conf
)
3775 /* device_lock is held */
3776 struct list_head head
;
3777 list_add(&head
, &conf
->bitmap_list
);
3778 list_del_init(&conf
->bitmap_list
);
3779 while (!list_empty(&head
)) {
3780 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3781 list_del_init(&sh
->lru
);
3782 atomic_inc(&sh
->count
);
3783 __release_stripe(conf
, sh
);
3787 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3789 struct r5conf
*conf
= mddev
->private;
3791 /* No difference between reads and writes. Just check
3792 * how busy the stripe_cache is
3795 if (conf
->inactive_blocked
)
3799 if (list_empty_careful(&conf
->inactive_list
))
3804 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3806 static int raid5_congested(void *data
, int bits
)
3808 struct mddev
*mddev
= data
;
3810 return mddev_congested(mddev
, bits
) ||
3811 md_raid5_congested(mddev
, bits
);
3814 /* We want read requests to align with chunks where possible,
3815 * but write requests don't need to.
3817 static int raid5_mergeable_bvec(struct request_queue
*q
,
3818 struct bvec_merge_data
*bvm
,
3819 struct bio_vec
*biovec
)
3821 struct mddev
*mddev
= q
->queuedata
;
3822 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3824 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3825 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3827 if ((bvm
->bi_rw
& 1) == WRITE
)
3828 return biovec
->bv_len
; /* always allow writes to be mergeable */
3830 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3831 chunk_sectors
= mddev
->new_chunk_sectors
;
3832 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3833 if (max
< 0) max
= 0;
3834 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3835 return biovec
->bv_len
;
3841 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3843 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3844 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3845 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3847 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3848 chunk_sectors
= mddev
->new_chunk_sectors
;
3849 return chunk_sectors
>=
3850 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3854 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3855 * later sampled by raid5d.
3857 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3859 unsigned long flags
;
3861 spin_lock_irqsave(&conf
->device_lock
, flags
);
3863 bi
->bi_next
= conf
->retry_read_aligned_list
;
3864 conf
->retry_read_aligned_list
= bi
;
3866 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3867 md_wakeup_thread(conf
->mddev
->thread
);
3871 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3875 bi
= conf
->retry_read_aligned
;
3877 conf
->retry_read_aligned
= NULL
;
3880 bi
= conf
->retry_read_aligned_list
;
3882 conf
->retry_read_aligned_list
= bi
->bi_next
;
3885 * this sets the active strip count to 1 and the processed
3886 * strip count to zero (upper 8 bits)
3888 raid5_set_bi_stripes(bi
, 1); /* biased count of active stripes */
3896 * The "raid5_align_endio" should check if the read succeeded and if it
3897 * did, call bio_endio on the original bio (having bio_put the new bio
3899 * If the read failed..
3901 static void raid5_align_endio(struct bio
*bi
, int error
)
3903 struct bio
* raid_bi
= bi
->bi_private
;
3904 struct mddev
*mddev
;
3905 struct r5conf
*conf
;
3906 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3907 struct md_rdev
*rdev
;
3911 rdev
= (void*)raid_bi
->bi_next
;
3912 raid_bi
->bi_next
= NULL
;
3913 mddev
= rdev
->mddev
;
3914 conf
= mddev
->private;
3916 rdev_dec_pending(rdev
, conf
->mddev
);
3918 if (!error
&& uptodate
) {
3919 trace_block_bio_complete(bdev_get_queue(raid_bi
->bi_bdev
),
3921 bio_endio(raid_bi
, 0);
3922 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3923 wake_up(&conf
->wait_for_stripe
);
3928 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3930 add_bio_to_retry(raid_bi
, conf
);
3933 static int bio_fits_rdev(struct bio
*bi
)
3935 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3937 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3939 blk_recount_segments(q
, bi
);
3940 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3943 if (q
->merge_bvec_fn
)
3944 /* it's too hard to apply the merge_bvec_fn at this stage,
3953 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3955 struct r5conf
*conf
= mddev
->private;
3957 struct bio
* align_bi
;
3958 struct md_rdev
*rdev
;
3959 sector_t end_sector
;
3961 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3962 pr_debug("chunk_aligned_read : non aligned\n");
3966 * use bio_clone_mddev to make a copy of the bio
3968 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3972 * set bi_end_io to a new function, and set bi_private to the
3975 align_bi
->bi_end_io
= raid5_align_endio
;
3976 align_bi
->bi_private
= raid_bio
;
3980 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3984 end_sector
= align_bi
->bi_sector
+ (align_bi
->bi_size
>> 9);
3986 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3987 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3988 rdev
->recovery_offset
< end_sector
) {
3989 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3991 (test_bit(Faulty
, &rdev
->flags
) ||
3992 !(test_bit(In_sync
, &rdev
->flags
) ||
3993 rdev
->recovery_offset
>= end_sector
)))
4000 atomic_inc(&rdev
->nr_pending
);
4002 raid_bio
->bi_next
= (void*)rdev
;
4003 align_bi
->bi_bdev
= rdev
->bdev
;
4004 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
4006 if (!bio_fits_rdev(align_bi
) ||
4007 is_badblock(rdev
, align_bi
->bi_sector
, align_bi
->bi_size
>>9,
4008 &first_bad
, &bad_sectors
)) {
4009 /* too big in some way, or has a known bad block */
4011 rdev_dec_pending(rdev
, mddev
);
4015 /* No reshape active, so we can trust rdev->data_offset */
4016 align_bi
->bi_sector
+= rdev
->data_offset
;
4018 spin_lock_irq(&conf
->device_lock
);
4019 wait_event_lock_irq(conf
->wait_for_stripe
,
4022 atomic_inc(&conf
->active_aligned_reads
);
4023 spin_unlock_irq(&conf
->device_lock
);
4026 trace_block_bio_remap(bdev_get_queue(align_bi
->bi_bdev
),
4027 align_bi
, disk_devt(mddev
->gendisk
),
4028 raid_bio
->bi_sector
);
4029 generic_make_request(align_bi
);
4038 /* __get_priority_stripe - get the next stripe to process
4040 * Full stripe writes are allowed to pass preread active stripes up until
4041 * the bypass_threshold is exceeded. In general the bypass_count
4042 * increments when the handle_list is handled before the hold_list; however, it
4043 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4044 * stripe with in flight i/o. The bypass_count will be reset when the
4045 * head of the hold_list has changed, i.e. the head was promoted to the
4048 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
4050 struct stripe_head
*sh
;
4052 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4054 list_empty(&conf
->handle_list
) ? "empty" : "busy",
4055 list_empty(&conf
->hold_list
) ? "empty" : "busy",
4056 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
4058 if (!list_empty(&conf
->handle_list
)) {
4059 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
4061 if (list_empty(&conf
->hold_list
))
4062 conf
->bypass_count
= 0;
4063 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
4064 if (conf
->hold_list
.next
== conf
->last_hold
)
4065 conf
->bypass_count
++;
4067 conf
->last_hold
= conf
->hold_list
.next
;
4068 conf
->bypass_count
-= conf
->bypass_threshold
;
4069 if (conf
->bypass_count
< 0)
4070 conf
->bypass_count
= 0;
4073 } else if (!list_empty(&conf
->hold_list
) &&
4074 ((conf
->bypass_threshold
&&
4075 conf
->bypass_count
> conf
->bypass_threshold
) ||
4076 atomic_read(&conf
->pending_full_writes
) == 0)) {
4077 sh
= list_entry(conf
->hold_list
.next
,
4079 conf
->bypass_count
-= conf
->bypass_threshold
;
4080 if (conf
->bypass_count
< 0)
4081 conf
->bypass_count
= 0;
4085 list_del_init(&sh
->lru
);
4086 atomic_inc(&sh
->count
);
4087 BUG_ON(atomic_read(&sh
->count
) != 1);
4091 struct raid5_plug_cb
{
4092 struct blk_plug_cb cb
;
4093 struct list_head list
;
4096 static void raid5_unplug(struct blk_plug_cb
*blk_cb
, bool from_schedule
)
4098 struct raid5_plug_cb
*cb
= container_of(
4099 blk_cb
, struct raid5_plug_cb
, cb
);
4100 struct stripe_head
*sh
;
4101 struct mddev
*mddev
= cb
->cb
.data
;
4102 struct r5conf
*conf
= mddev
->private;
4105 if (cb
->list
.next
&& !list_empty(&cb
->list
)) {
4106 spin_lock_irq(&conf
->device_lock
);
4107 while (!list_empty(&cb
->list
)) {
4108 sh
= list_first_entry(&cb
->list
, struct stripe_head
, lru
);
4109 list_del_init(&sh
->lru
);
4111 * avoid race release_stripe_plug() sees
4112 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4113 * is still in our list
4115 smp_mb__before_clear_bit();
4116 clear_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
);
4117 __release_stripe(conf
, sh
);
4120 spin_unlock_irq(&conf
->device_lock
);
4123 trace_block_unplug(mddev
->queue
, cnt
, !from_schedule
);
4127 static void release_stripe_plug(struct mddev
*mddev
,
4128 struct stripe_head
*sh
)
4130 struct blk_plug_cb
*blk_cb
= blk_check_plugged(
4131 raid5_unplug
, mddev
,
4132 sizeof(struct raid5_plug_cb
));
4133 struct raid5_plug_cb
*cb
;
4140 cb
= container_of(blk_cb
, struct raid5_plug_cb
, cb
);
4142 if (cb
->list
.next
== NULL
)
4143 INIT_LIST_HEAD(&cb
->list
);
4145 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
))
4146 list_add_tail(&sh
->lru
, &cb
->list
);
4151 static void make_discard_request(struct mddev
*mddev
, struct bio
*bi
)
4153 struct r5conf
*conf
= mddev
->private;
4154 sector_t logical_sector
, last_sector
;
4155 struct stripe_head
*sh
;
4159 if (mddev
->reshape_position
!= MaxSector
)
4160 /* Skip discard while reshape is happening */
4163 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4164 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4167 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4169 stripe_sectors
= conf
->chunk_sectors
*
4170 (conf
->raid_disks
- conf
->max_degraded
);
4171 logical_sector
= DIV_ROUND_UP_SECTOR_T(logical_sector
,
4173 sector_div(last_sector
, stripe_sectors
);
4175 logical_sector
*= conf
->chunk_sectors
;
4176 last_sector
*= conf
->chunk_sectors
;
4178 for (; logical_sector
< last_sector
;
4179 logical_sector
+= STRIPE_SECTORS
) {
4183 sh
= get_active_stripe(conf
, logical_sector
, 0, 0, 0);
4184 prepare_to_wait(&conf
->wait_for_overlap
, &w
,
4185 TASK_UNINTERRUPTIBLE
);
4186 set_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4187 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
4192 clear_bit(R5_Overlap
, &sh
->dev
[sh
->pd_idx
].flags
);
4193 spin_lock_irq(&sh
->stripe_lock
);
4194 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4195 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4197 if (sh
->dev
[d
].towrite
|| sh
->dev
[d
].toread
) {
4198 set_bit(R5_Overlap
, &sh
->dev
[d
].flags
);
4199 spin_unlock_irq(&sh
->stripe_lock
);
4205 set_bit(STRIPE_DISCARD
, &sh
->state
);
4206 finish_wait(&conf
->wait_for_overlap
, &w
);
4207 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4208 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4210 sh
->dev
[d
].towrite
= bi
;
4211 set_bit(R5_OVERWRITE
, &sh
->dev
[d
].flags
);
4212 raid5_inc_bi_active_stripes(bi
);
4214 spin_unlock_irq(&sh
->stripe_lock
);
4215 if (conf
->mddev
->bitmap
) {
4217 d
< conf
->raid_disks
- conf
->max_degraded
;
4219 bitmap_startwrite(mddev
->bitmap
,
4223 sh
->bm_seq
= conf
->seq_flush
+ 1;
4224 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
4227 set_bit(STRIPE_HANDLE
, &sh
->state
);
4228 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4229 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4230 atomic_inc(&conf
->preread_active_stripes
);
4231 release_stripe_plug(mddev
, sh
);
4234 remaining
= raid5_dec_bi_active_stripes(bi
);
4235 if (remaining
== 0) {
4236 md_write_end(mddev
);
4241 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4243 struct r5conf
*conf
= mddev
->private;
4245 sector_t new_sector
;
4246 sector_t logical_sector
, last_sector
;
4247 struct stripe_head
*sh
;
4248 const int rw
= bio_data_dir(bi
);
4251 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4252 md_flush_request(mddev
, bi
);
4256 md_write_start(mddev
, bi
);
4259 mddev
->reshape_position
== MaxSector
&&
4260 chunk_aligned_read(mddev
,bi
))
4263 if (unlikely(bi
->bi_rw
& REQ_DISCARD
)) {
4264 make_discard_request(mddev
, bi
);
4268 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4269 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4271 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4273 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4279 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4280 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4281 /* spinlock is needed as reshape_progress may be
4282 * 64bit on a 32bit platform, and so it might be
4283 * possible to see a half-updated value
4284 * Of course reshape_progress could change after
4285 * the lock is dropped, so once we get a reference
4286 * to the stripe that we think it is, we will have
4289 spin_lock_irq(&conf
->device_lock
);
4290 if (mddev
->reshape_backwards
4291 ? logical_sector
< conf
->reshape_progress
4292 : logical_sector
>= conf
->reshape_progress
) {
4295 if (mddev
->reshape_backwards
4296 ? logical_sector
< conf
->reshape_safe
4297 : logical_sector
>= conf
->reshape_safe
) {
4298 spin_unlock_irq(&conf
->device_lock
);
4303 spin_unlock_irq(&conf
->device_lock
);
4306 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4309 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4310 (unsigned long long)new_sector
,
4311 (unsigned long long)logical_sector
);
4313 sh
= get_active_stripe(conf
, new_sector
, previous
,
4314 (bi
->bi_rw
&RWA_MASK
), 0);
4316 if (unlikely(previous
)) {
4317 /* expansion might have moved on while waiting for a
4318 * stripe, so we must do the range check again.
4319 * Expansion could still move past after this
4320 * test, but as we are holding a reference to
4321 * 'sh', we know that if that happens,
4322 * STRIPE_EXPANDING will get set and the expansion
4323 * won't proceed until we finish with the stripe.
4326 spin_lock_irq(&conf
->device_lock
);
4327 if (mddev
->reshape_backwards
4328 ? logical_sector
>= conf
->reshape_progress
4329 : logical_sector
< conf
->reshape_progress
)
4330 /* mismatch, need to try again */
4332 spin_unlock_irq(&conf
->device_lock
);
4341 logical_sector
>= mddev
->suspend_lo
&&
4342 logical_sector
< mddev
->suspend_hi
) {
4344 /* As the suspend_* range is controlled by
4345 * userspace, we want an interruptible
4348 flush_signals(current
);
4349 prepare_to_wait(&conf
->wait_for_overlap
,
4350 &w
, TASK_INTERRUPTIBLE
);
4351 if (logical_sector
>= mddev
->suspend_lo
&&
4352 logical_sector
< mddev
->suspend_hi
)
4357 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4358 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4359 /* Stripe is busy expanding or
4360 * add failed due to overlap. Flush everything
4363 md_wakeup_thread(mddev
->thread
);
4368 finish_wait(&conf
->wait_for_overlap
, &w
);
4369 set_bit(STRIPE_HANDLE
, &sh
->state
);
4370 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4371 if ((bi
->bi_rw
& REQ_SYNC
) &&
4372 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4373 atomic_inc(&conf
->preread_active_stripes
);
4374 release_stripe_plug(mddev
, sh
);
4376 /* cannot get stripe for read-ahead, just give-up */
4377 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4378 finish_wait(&conf
->wait_for_overlap
, &w
);
4383 remaining
= raid5_dec_bi_active_stripes(bi
);
4384 if (remaining
== 0) {
4387 md_write_end(mddev
);
4389 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
4395 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4397 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4399 /* reshaping is quite different to recovery/resync so it is
4400 * handled quite separately ... here.
4402 * On each call to sync_request, we gather one chunk worth of
4403 * destination stripes and flag them as expanding.
4404 * Then we find all the source stripes and request reads.
4405 * As the reads complete, handle_stripe will copy the data
4406 * into the destination stripe and release that stripe.
4408 struct r5conf
*conf
= mddev
->private;
4409 struct stripe_head
*sh
;
4410 sector_t first_sector
, last_sector
;
4411 int raid_disks
= conf
->previous_raid_disks
;
4412 int data_disks
= raid_disks
- conf
->max_degraded
;
4413 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4416 sector_t writepos
, readpos
, safepos
;
4417 sector_t stripe_addr
;
4418 int reshape_sectors
;
4419 struct list_head stripes
;
4421 if (sector_nr
== 0) {
4422 /* If restarting in the middle, skip the initial sectors */
4423 if (mddev
->reshape_backwards
&&
4424 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4425 sector_nr
= raid5_size(mddev
, 0, 0)
4426 - conf
->reshape_progress
;
4427 } else if (!mddev
->reshape_backwards
&&
4428 conf
->reshape_progress
> 0)
4429 sector_nr
= conf
->reshape_progress
;
4430 sector_div(sector_nr
, new_data_disks
);
4432 mddev
->curr_resync_completed
= sector_nr
;
4433 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4439 /* We need to process a full chunk at a time.
4440 * If old and new chunk sizes differ, we need to process the
4443 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4444 reshape_sectors
= mddev
->new_chunk_sectors
;
4446 reshape_sectors
= mddev
->chunk_sectors
;
4448 /* We update the metadata at least every 10 seconds, or when
4449 * the data about to be copied would over-write the source of
4450 * the data at the front of the range. i.e. one new_stripe
4451 * along from reshape_progress new_maps to after where
4452 * reshape_safe old_maps to
4454 writepos
= conf
->reshape_progress
;
4455 sector_div(writepos
, new_data_disks
);
4456 readpos
= conf
->reshape_progress
;
4457 sector_div(readpos
, data_disks
);
4458 safepos
= conf
->reshape_safe
;
4459 sector_div(safepos
, data_disks
);
4460 if (mddev
->reshape_backwards
) {
4461 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4462 readpos
+= reshape_sectors
;
4463 safepos
+= reshape_sectors
;
4465 writepos
+= reshape_sectors
;
4466 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4467 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4470 /* Having calculated the 'writepos' possibly use it
4471 * to set 'stripe_addr' which is where we will write to.
4473 if (mddev
->reshape_backwards
) {
4474 BUG_ON(conf
->reshape_progress
== 0);
4475 stripe_addr
= writepos
;
4476 BUG_ON((mddev
->dev_sectors
&
4477 ~((sector_t
)reshape_sectors
- 1))
4478 - reshape_sectors
- stripe_addr
4481 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4482 stripe_addr
= sector_nr
;
4485 /* 'writepos' is the most advanced device address we might write.
4486 * 'readpos' is the least advanced device address we might read.
4487 * 'safepos' is the least address recorded in the metadata as having
4489 * If there is a min_offset_diff, these are adjusted either by
4490 * increasing the safepos/readpos if diff is negative, or
4491 * increasing writepos if diff is positive.
4492 * If 'readpos' is then behind 'writepos', there is no way that we can
4493 * ensure safety in the face of a crash - that must be done by userspace
4494 * making a backup of the data. So in that case there is no particular
4495 * rush to update metadata.
4496 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4497 * update the metadata to advance 'safepos' to match 'readpos' so that
4498 * we can be safe in the event of a crash.
4499 * So we insist on updating metadata if safepos is behind writepos and
4500 * readpos is beyond writepos.
4501 * In any case, update the metadata every 10 seconds.
4502 * Maybe that number should be configurable, but I'm not sure it is
4503 * worth it.... maybe it could be a multiple of safemode_delay???
4505 if (conf
->min_offset_diff
< 0) {
4506 safepos
+= -conf
->min_offset_diff
;
4507 readpos
+= -conf
->min_offset_diff
;
4509 writepos
+= conf
->min_offset_diff
;
4511 if ((mddev
->reshape_backwards
4512 ? (safepos
> writepos
&& readpos
< writepos
)
4513 : (safepos
< writepos
&& readpos
> writepos
)) ||
4514 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4515 /* Cannot proceed until we've updated the superblock... */
4516 wait_event(conf
->wait_for_overlap
,
4517 atomic_read(&conf
->reshape_stripes
)==0);
4518 mddev
->reshape_position
= conf
->reshape_progress
;
4519 mddev
->curr_resync_completed
= sector_nr
;
4520 conf
->reshape_checkpoint
= jiffies
;
4521 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4522 md_wakeup_thread(mddev
->thread
);
4523 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4524 kthread_should_stop());
4525 spin_lock_irq(&conf
->device_lock
);
4526 conf
->reshape_safe
= mddev
->reshape_position
;
4527 spin_unlock_irq(&conf
->device_lock
);
4528 wake_up(&conf
->wait_for_overlap
);
4529 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4532 INIT_LIST_HEAD(&stripes
);
4533 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4535 int skipped_disk
= 0;
4536 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4537 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4538 atomic_inc(&conf
->reshape_stripes
);
4539 /* If any of this stripe is beyond the end of the old
4540 * array, then we need to zero those blocks
4542 for (j
=sh
->disks
; j
--;) {
4544 if (j
== sh
->pd_idx
)
4546 if (conf
->level
== 6 &&
4549 s
= compute_blocknr(sh
, j
, 0);
4550 if (s
< raid5_size(mddev
, 0, 0)) {
4554 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4555 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4556 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4558 if (!skipped_disk
) {
4559 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4560 set_bit(STRIPE_HANDLE
, &sh
->state
);
4562 list_add(&sh
->lru
, &stripes
);
4564 spin_lock_irq(&conf
->device_lock
);
4565 if (mddev
->reshape_backwards
)
4566 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4568 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4569 spin_unlock_irq(&conf
->device_lock
);
4570 /* Ok, those stripe are ready. We can start scheduling
4571 * reads on the source stripes.
4572 * The source stripes are determined by mapping the first and last
4573 * block on the destination stripes.
4576 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4579 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4580 * new_data_disks
- 1),
4582 if (last_sector
>= mddev
->dev_sectors
)
4583 last_sector
= mddev
->dev_sectors
- 1;
4584 while (first_sector
<= last_sector
) {
4585 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4586 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4587 set_bit(STRIPE_HANDLE
, &sh
->state
);
4589 first_sector
+= STRIPE_SECTORS
;
4591 /* Now that the sources are clearly marked, we can release
4592 * the destination stripes
4594 while (!list_empty(&stripes
)) {
4595 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4596 list_del_init(&sh
->lru
);
4599 /* If this takes us to the resync_max point where we have to pause,
4600 * then we need to write out the superblock.
4602 sector_nr
+= reshape_sectors
;
4603 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4604 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4605 /* Cannot proceed until we've updated the superblock... */
4606 wait_event(conf
->wait_for_overlap
,
4607 atomic_read(&conf
->reshape_stripes
) == 0);
4608 mddev
->reshape_position
= conf
->reshape_progress
;
4609 mddev
->curr_resync_completed
= sector_nr
;
4610 conf
->reshape_checkpoint
= jiffies
;
4611 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4612 md_wakeup_thread(mddev
->thread
);
4613 wait_event(mddev
->sb_wait
,
4614 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4615 || kthread_should_stop());
4616 spin_lock_irq(&conf
->device_lock
);
4617 conf
->reshape_safe
= mddev
->reshape_position
;
4618 spin_unlock_irq(&conf
->device_lock
);
4619 wake_up(&conf
->wait_for_overlap
);
4620 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4622 return reshape_sectors
;
4625 /* FIXME go_faster isn't used */
4626 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4628 struct r5conf
*conf
= mddev
->private;
4629 struct stripe_head
*sh
;
4630 sector_t max_sector
= mddev
->dev_sectors
;
4631 sector_t sync_blocks
;
4632 int still_degraded
= 0;
4635 if (sector_nr
>= max_sector
) {
4636 /* just being told to finish up .. nothing much to do */
4638 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4643 if (mddev
->curr_resync
< max_sector
) /* aborted */
4644 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4646 else /* completed sync */
4648 bitmap_close_sync(mddev
->bitmap
);
4653 /* Allow raid5_quiesce to complete */
4654 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4656 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4657 return reshape_request(mddev
, sector_nr
, skipped
);
4659 /* No need to check resync_max as we never do more than one
4660 * stripe, and as resync_max will always be on a chunk boundary,
4661 * if the check in md_do_sync didn't fire, there is no chance
4662 * of overstepping resync_max here
4665 /* if there is too many failed drives and we are trying
4666 * to resync, then assert that we are finished, because there is
4667 * nothing we can do.
4669 if (mddev
->degraded
>= conf
->max_degraded
&&
4670 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4671 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4675 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4676 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4677 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4678 /* we can skip this block, and probably more */
4679 sync_blocks
/= STRIPE_SECTORS
;
4681 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4684 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4686 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4688 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4689 /* make sure we don't swamp the stripe cache if someone else
4690 * is trying to get access
4692 schedule_timeout_uninterruptible(1);
4694 /* Need to check if array will still be degraded after recovery/resync
4695 * We don't need to check the 'failed' flag as when that gets set,
4698 for (i
= 0; i
< conf
->raid_disks
; i
++)
4699 if (conf
->disks
[i
].rdev
== NULL
)
4702 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4704 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4709 return STRIPE_SECTORS
;
4712 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4714 /* We may not be able to submit a whole bio at once as there
4715 * may not be enough stripe_heads available.
4716 * We cannot pre-allocate enough stripe_heads as we may need
4717 * more than exist in the cache (if we allow ever large chunks).
4718 * So we do one stripe head at a time and record in
4719 * ->bi_hw_segments how many have been done.
4721 * We *know* that this entire raid_bio is in one chunk, so
4722 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4724 struct stripe_head
*sh
;
4726 sector_t sector
, logical_sector
, last_sector
;
4731 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4732 sector
= raid5_compute_sector(conf
, logical_sector
,
4734 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4736 for (; logical_sector
< last_sector
;
4737 logical_sector
+= STRIPE_SECTORS
,
4738 sector
+= STRIPE_SECTORS
,
4741 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4742 /* already done this stripe */
4745 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4748 /* failed to get a stripe - must wait */
4749 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4750 conf
->retry_read_aligned
= raid_bio
;
4754 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4756 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4757 conf
->retry_read_aligned
= raid_bio
;
4761 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4766 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4767 if (remaining
== 0) {
4768 trace_block_bio_complete(bdev_get_queue(raid_bio
->bi_bdev
),
4770 bio_endio(raid_bio
, 0);
4772 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4773 wake_up(&conf
->wait_for_stripe
);
4777 #define MAX_STRIPE_BATCH 8
4778 static int handle_active_stripes(struct r5conf
*conf
)
4780 struct stripe_head
*batch
[MAX_STRIPE_BATCH
], *sh
;
4781 int i
, batch_size
= 0;
4783 while (batch_size
< MAX_STRIPE_BATCH
&&
4784 (sh
= __get_priority_stripe(conf
)) != NULL
)
4785 batch
[batch_size
++] = sh
;
4787 if (batch_size
== 0)
4789 spin_unlock_irq(&conf
->device_lock
);
4791 for (i
= 0; i
< batch_size
; i
++)
4792 handle_stripe(batch
[i
]);
4796 spin_lock_irq(&conf
->device_lock
);
4797 for (i
= 0; i
< batch_size
; i
++)
4798 __release_stripe(conf
, batch
[i
]);
4803 * This is our raid5 kernel thread.
4805 * We scan the hash table for stripes which can be handled now.
4806 * During the scan, completed stripes are saved for us by the interrupt
4807 * handler, so that they will not have to wait for our next wakeup.
4809 static void raid5d(struct md_thread
*thread
)
4811 struct mddev
*mddev
= thread
->mddev
;
4812 struct r5conf
*conf
= mddev
->private;
4814 struct blk_plug plug
;
4816 pr_debug("+++ raid5d active\n");
4818 md_check_recovery(mddev
);
4820 blk_start_plug(&plug
);
4822 spin_lock_irq(&conf
->device_lock
);
4828 !list_empty(&conf
->bitmap_list
)) {
4829 /* Now is a good time to flush some bitmap updates */
4831 spin_unlock_irq(&conf
->device_lock
);
4832 bitmap_unplug(mddev
->bitmap
);
4833 spin_lock_irq(&conf
->device_lock
);
4834 conf
->seq_write
= conf
->seq_flush
;
4835 activate_bit_delay(conf
);
4837 raid5_activate_delayed(conf
);
4839 while ((bio
= remove_bio_from_retry(conf
))) {
4841 spin_unlock_irq(&conf
->device_lock
);
4842 ok
= retry_aligned_read(conf
, bio
);
4843 spin_lock_irq(&conf
->device_lock
);
4849 batch_size
= handle_active_stripes(conf
);
4852 handled
+= batch_size
;
4854 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
)) {
4855 spin_unlock_irq(&conf
->device_lock
);
4856 md_check_recovery(mddev
);
4857 spin_lock_irq(&conf
->device_lock
);
4860 pr_debug("%d stripes handled\n", handled
);
4862 spin_unlock_irq(&conf
->device_lock
);
4864 async_tx_issue_pending_all();
4865 blk_finish_plug(&plug
);
4867 pr_debug("--- raid5d inactive\n");
4871 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4873 struct r5conf
*conf
= mddev
->private;
4875 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4881 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4883 struct r5conf
*conf
= mddev
->private;
4886 if (size
<= 16 || size
> 32768)
4888 while (size
< conf
->max_nr_stripes
) {
4889 if (drop_one_stripe(conf
))
4890 conf
->max_nr_stripes
--;
4894 err
= md_allow_write(mddev
);
4897 while (size
> conf
->max_nr_stripes
) {
4898 if (grow_one_stripe(conf
))
4899 conf
->max_nr_stripes
++;
4904 EXPORT_SYMBOL(raid5_set_cache_size
);
4907 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4909 struct r5conf
*conf
= mddev
->private;
4913 if (len
>= PAGE_SIZE
)
4918 if (strict_strtoul(page
, 10, &new))
4920 err
= raid5_set_cache_size(mddev
, new);
4926 static struct md_sysfs_entry
4927 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4928 raid5_show_stripe_cache_size
,
4929 raid5_store_stripe_cache_size
);
4932 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4934 struct r5conf
*conf
= mddev
->private;
4936 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4942 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4944 struct r5conf
*conf
= mddev
->private;
4946 if (len
>= PAGE_SIZE
)
4951 if (strict_strtoul(page
, 10, &new))
4953 if (new > conf
->max_nr_stripes
)
4955 conf
->bypass_threshold
= new;
4959 static struct md_sysfs_entry
4960 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4962 raid5_show_preread_threshold
,
4963 raid5_store_preread_threshold
);
4966 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4968 struct r5conf
*conf
= mddev
->private;
4970 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4975 static struct md_sysfs_entry
4976 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4978 static struct attribute
*raid5_attrs
[] = {
4979 &raid5_stripecache_size
.attr
,
4980 &raid5_stripecache_active
.attr
,
4981 &raid5_preread_bypass_threshold
.attr
,
4984 static struct attribute_group raid5_attrs_group
= {
4986 .attrs
= raid5_attrs
,
4990 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4992 struct r5conf
*conf
= mddev
->private;
4995 sectors
= mddev
->dev_sectors
;
4997 /* size is defined by the smallest of previous and new size */
4998 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
5000 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5001 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
5002 return sectors
* (raid_disks
- conf
->max_degraded
);
5005 static void raid5_free_percpu(struct r5conf
*conf
)
5007 struct raid5_percpu
*percpu
;
5014 for_each_possible_cpu(cpu
) {
5015 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5016 safe_put_page(percpu
->spare_page
);
5017 kfree(percpu
->scribble
);
5019 #ifdef CONFIG_HOTPLUG_CPU
5020 unregister_cpu_notifier(&conf
->cpu_notify
);
5024 free_percpu(conf
->percpu
);
5027 static void free_conf(struct r5conf
*conf
)
5029 shrink_stripes(conf
);
5030 raid5_free_percpu(conf
);
5032 kfree(conf
->stripe_hashtbl
);
5036 #ifdef CONFIG_HOTPLUG_CPU
5037 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
5040 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
5041 long cpu
= (long)hcpu
;
5042 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5045 case CPU_UP_PREPARE
:
5046 case CPU_UP_PREPARE_FROZEN
:
5047 if (conf
->level
== 6 && !percpu
->spare_page
)
5048 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
5049 if (!percpu
->scribble
)
5050 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5052 if (!percpu
->scribble
||
5053 (conf
->level
== 6 && !percpu
->spare_page
)) {
5054 safe_put_page(percpu
->spare_page
);
5055 kfree(percpu
->scribble
);
5056 pr_err("%s: failed memory allocation for cpu%ld\n",
5058 return notifier_from_errno(-ENOMEM
);
5062 case CPU_DEAD_FROZEN
:
5063 safe_put_page(percpu
->spare_page
);
5064 kfree(percpu
->scribble
);
5065 percpu
->spare_page
= NULL
;
5066 percpu
->scribble
= NULL
;
5075 static int raid5_alloc_percpu(struct r5conf
*conf
)
5078 struct page
*spare_page
;
5079 struct raid5_percpu __percpu
*allcpus
;
5083 allcpus
= alloc_percpu(struct raid5_percpu
);
5086 conf
->percpu
= allcpus
;
5090 for_each_present_cpu(cpu
) {
5091 if (conf
->level
== 6) {
5092 spare_page
= alloc_page(GFP_KERNEL
);
5097 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
5099 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5104 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
5106 #ifdef CONFIG_HOTPLUG_CPU
5107 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
5108 conf
->cpu_notify
.priority
= 0;
5110 err
= register_cpu_notifier(&conf
->cpu_notify
);
5117 static struct r5conf
*setup_conf(struct mddev
*mddev
)
5119 struct r5conf
*conf
;
5120 int raid_disk
, memory
, max_disks
;
5121 struct md_rdev
*rdev
;
5122 struct disk_info
*disk
;
5125 if (mddev
->new_level
!= 5
5126 && mddev
->new_level
!= 4
5127 && mddev
->new_level
!= 6) {
5128 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5129 mdname(mddev
), mddev
->new_level
);
5130 return ERR_PTR(-EIO
);
5132 if ((mddev
->new_level
== 5
5133 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
5134 (mddev
->new_level
== 6
5135 && !algorithm_valid_raid6(mddev
->new_layout
))) {
5136 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
5137 mdname(mddev
), mddev
->new_layout
);
5138 return ERR_PTR(-EIO
);
5140 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
5141 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5142 mdname(mddev
), mddev
->raid_disks
);
5143 return ERR_PTR(-EINVAL
);
5146 if (!mddev
->new_chunk_sectors
||
5147 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
5148 !is_power_of_2(mddev
->new_chunk_sectors
)) {
5149 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
5150 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
5151 return ERR_PTR(-EINVAL
);
5154 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
5157 spin_lock_init(&conf
->device_lock
);
5158 init_waitqueue_head(&conf
->wait_for_stripe
);
5159 init_waitqueue_head(&conf
->wait_for_overlap
);
5160 INIT_LIST_HEAD(&conf
->handle_list
);
5161 INIT_LIST_HEAD(&conf
->hold_list
);
5162 INIT_LIST_HEAD(&conf
->delayed_list
);
5163 INIT_LIST_HEAD(&conf
->bitmap_list
);
5164 INIT_LIST_HEAD(&conf
->inactive_list
);
5165 atomic_set(&conf
->active_stripes
, 0);
5166 atomic_set(&conf
->preread_active_stripes
, 0);
5167 atomic_set(&conf
->active_aligned_reads
, 0);
5168 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
5169 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
5171 conf
->raid_disks
= mddev
->raid_disks
;
5172 if (mddev
->reshape_position
== MaxSector
)
5173 conf
->previous_raid_disks
= mddev
->raid_disks
;
5175 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5176 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
5177 conf
->scribble_len
= scribble_len(max_disks
);
5179 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
5184 conf
->mddev
= mddev
;
5186 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
5189 conf
->level
= mddev
->new_level
;
5190 if (raid5_alloc_percpu(conf
) != 0)
5193 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
5195 rdev_for_each(rdev
, mddev
) {
5196 raid_disk
= rdev
->raid_disk
;
5197 if (raid_disk
>= max_disks
5200 disk
= conf
->disks
+ raid_disk
;
5202 if (test_bit(Replacement
, &rdev
->flags
)) {
5203 if (disk
->replacement
)
5205 disk
->replacement
= rdev
;
5212 if (test_bit(In_sync
, &rdev
->flags
)) {
5213 char b
[BDEVNAME_SIZE
];
5214 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
5216 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
5217 } else if (rdev
->saved_raid_disk
!= raid_disk
)
5218 /* Cannot rely on bitmap to complete recovery */
5222 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5223 conf
->level
= mddev
->new_level
;
5224 if (conf
->level
== 6)
5225 conf
->max_degraded
= 2;
5227 conf
->max_degraded
= 1;
5228 conf
->algorithm
= mddev
->new_layout
;
5229 conf
->max_nr_stripes
= NR_STRIPES
;
5230 conf
->reshape_progress
= mddev
->reshape_position
;
5231 if (conf
->reshape_progress
!= MaxSector
) {
5232 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
5233 conf
->prev_algo
= mddev
->layout
;
5236 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
5237 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
5238 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
5240 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5241 mdname(mddev
), memory
);
5244 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
5245 mdname(mddev
), memory
);
5247 sprintf(pers_name
, "raid%d", mddev
->new_level
);
5248 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
5249 if (!conf
->thread
) {
5251 "md/raid:%s: couldn't allocate thread.\n",
5261 return ERR_PTR(-EIO
);
5263 return ERR_PTR(-ENOMEM
);
5267 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5270 case ALGORITHM_PARITY_0
:
5271 if (raid_disk
< max_degraded
)
5274 case ALGORITHM_PARITY_N
:
5275 if (raid_disk
>= raid_disks
- max_degraded
)
5278 case ALGORITHM_PARITY_0_6
:
5279 if (raid_disk
== 0 ||
5280 raid_disk
== raid_disks
- 1)
5283 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5284 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5285 case ALGORITHM_LEFT_SYMMETRIC_6
:
5286 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5287 if (raid_disk
== raid_disks
- 1)
5293 static int run(struct mddev
*mddev
)
5295 struct r5conf
*conf
;
5296 int working_disks
= 0;
5297 int dirty_parity_disks
= 0;
5298 struct md_rdev
*rdev
;
5299 sector_t reshape_offset
= 0;
5301 long long min_offset_diff
= 0;
5304 if (mddev
->recovery_cp
!= MaxSector
)
5305 printk(KERN_NOTICE
"md/raid:%s: not clean"
5306 " -- starting background reconstruction\n",
5309 rdev_for_each(rdev
, mddev
) {
5311 if (rdev
->raid_disk
< 0)
5313 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5315 min_offset_diff
= diff
;
5317 } else if (mddev
->reshape_backwards
&&
5318 diff
< min_offset_diff
)
5319 min_offset_diff
= diff
;
5320 else if (!mddev
->reshape_backwards
&&
5321 diff
> min_offset_diff
)
5322 min_offset_diff
= diff
;
5325 if (mddev
->reshape_position
!= MaxSector
) {
5326 /* Check that we can continue the reshape.
5327 * Difficulties arise if the stripe we would write to
5328 * next is at or after the stripe we would read from next.
5329 * For a reshape that changes the number of devices, this
5330 * is only possible for a very short time, and mdadm makes
5331 * sure that time appears to have past before assembling
5332 * the array. So we fail if that time hasn't passed.
5333 * For a reshape that keeps the number of devices the same
5334 * mdadm must be monitoring the reshape can keeping the
5335 * critical areas read-only and backed up. It will start
5336 * the array in read-only mode, so we check for that.
5338 sector_t here_new
, here_old
;
5340 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5342 if (mddev
->new_level
!= mddev
->level
) {
5343 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5344 "required - aborting.\n",
5348 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5349 /* reshape_position must be on a new-stripe boundary, and one
5350 * further up in new geometry must map after here in old
5353 here_new
= mddev
->reshape_position
;
5354 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5355 (mddev
->raid_disks
- max_degraded
))) {
5356 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5357 "on a stripe boundary\n", mdname(mddev
));
5360 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5361 /* here_new is the stripe we will write to */
5362 here_old
= mddev
->reshape_position
;
5363 sector_div(here_old
, mddev
->chunk_sectors
*
5364 (old_disks
-max_degraded
));
5365 /* here_old is the first stripe that we might need to read
5367 if (mddev
->delta_disks
== 0) {
5368 if ((here_new
* mddev
->new_chunk_sectors
!=
5369 here_old
* mddev
->chunk_sectors
)) {
5370 printk(KERN_ERR
"md/raid:%s: reshape position is"
5371 " confused - aborting\n", mdname(mddev
));
5374 /* We cannot be sure it is safe to start an in-place
5375 * reshape. It is only safe if user-space is monitoring
5376 * and taking constant backups.
5377 * mdadm always starts a situation like this in
5378 * readonly mode so it can take control before
5379 * allowing any writes. So just check for that.
5381 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5382 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5383 /* not really in-place - so OK */;
5384 else if (mddev
->ro
== 0) {
5385 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5386 "must be started in read-only mode "
5391 } else if (mddev
->reshape_backwards
5392 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5393 here_old
* mddev
->chunk_sectors
)
5394 : (here_new
* mddev
->new_chunk_sectors
>=
5395 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5396 /* Reading from the same stripe as writing to - bad */
5397 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5398 "auto-recovery - aborting.\n",
5402 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5404 /* OK, we should be able to continue; */
5406 BUG_ON(mddev
->level
!= mddev
->new_level
);
5407 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5408 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5409 BUG_ON(mddev
->delta_disks
!= 0);
5412 if (mddev
->private == NULL
)
5413 conf
= setup_conf(mddev
);
5415 conf
= mddev
->private;
5418 return PTR_ERR(conf
);
5420 conf
->min_offset_diff
= min_offset_diff
;
5421 mddev
->thread
= conf
->thread
;
5422 conf
->thread
= NULL
;
5423 mddev
->private = conf
;
5425 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5427 rdev
= conf
->disks
[i
].rdev
;
5428 if (!rdev
&& conf
->disks
[i
].replacement
) {
5429 /* The replacement is all we have yet */
5430 rdev
= conf
->disks
[i
].replacement
;
5431 conf
->disks
[i
].replacement
= NULL
;
5432 clear_bit(Replacement
, &rdev
->flags
);
5433 conf
->disks
[i
].rdev
= rdev
;
5437 if (conf
->disks
[i
].replacement
&&
5438 conf
->reshape_progress
!= MaxSector
) {
5439 /* replacements and reshape simply do not mix. */
5440 printk(KERN_ERR
"md: cannot handle concurrent "
5441 "replacement and reshape.\n");
5444 if (test_bit(In_sync
, &rdev
->flags
)) {
5448 /* This disc is not fully in-sync. However if it
5449 * just stored parity (beyond the recovery_offset),
5450 * when we don't need to be concerned about the
5451 * array being dirty.
5452 * When reshape goes 'backwards', we never have
5453 * partially completed devices, so we only need
5454 * to worry about reshape going forwards.
5456 /* Hack because v0.91 doesn't store recovery_offset properly. */
5457 if (mddev
->major_version
== 0 &&
5458 mddev
->minor_version
> 90)
5459 rdev
->recovery_offset
= reshape_offset
;
5461 if (rdev
->recovery_offset
< reshape_offset
) {
5462 /* We need to check old and new layout */
5463 if (!only_parity(rdev
->raid_disk
,
5466 conf
->max_degraded
))
5469 if (!only_parity(rdev
->raid_disk
,
5471 conf
->previous_raid_disks
,
5472 conf
->max_degraded
))
5474 dirty_parity_disks
++;
5478 * 0 for a fully functional array, 1 or 2 for a degraded array.
5480 mddev
->degraded
= calc_degraded(conf
);
5482 if (has_failed(conf
)) {
5483 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5484 " (%d/%d failed)\n",
5485 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5489 /* device size must be a multiple of chunk size */
5490 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5491 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5493 if (mddev
->degraded
> dirty_parity_disks
&&
5494 mddev
->recovery_cp
!= MaxSector
) {
5495 if (mddev
->ok_start_degraded
)
5497 "md/raid:%s: starting dirty degraded array"
5498 " - data corruption possible.\n",
5502 "md/raid:%s: cannot start dirty degraded array.\n",
5508 if (mddev
->degraded
== 0)
5509 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5510 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5511 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5514 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5515 " out of %d devices, algorithm %d\n",
5516 mdname(mddev
), conf
->level
,
5517 mddev
->raid_disks
- mddev
->degraded
,
5518 mddev
->raid_disks
, mddev
->new_layout
);
5520 print_raid5_conf(conf
);
5522 if (conf
->reshape_progress
!= MaxSector
) {
5523 conf
->reshape_safe
= conf
->reshape_progress
;
5524 atomic_set(&conf
->reshape_stripes
, 0);
5525 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5526 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5527 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5528 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5529 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5534 /* Ok, everything is just fine now */
5535 if (mddev
->to_remove
== &raid5_attrs_group
)
5536 mddev
->to_remove
= NULL
;
5537 else if (mddev
->kobj
.sd
&&
5538 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5540 "raid5: failed to create sysfs attributes for %s\n",
5542 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5546 bool discard_supported
= true;
5547 /* read-ahead size must cover two whole stripes, which
5548 * is 2 * (datadisks) * chunksize where 'n' is the
5549 * number of raid devices
5551 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5552 int stripe
= data_disks
*
5553 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5554 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5555 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5557 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5559 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5560 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5562 chunk_size
= mddev
->chunk_sectors
<< 9;
5563 blk_queue_io_min(mddev
->queue
, chunk_size
);
5564 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5565 (conf
->raid_disks
- conf
->max_degraded
));
5567 * We can only discard a whole stripe. It doesn't make sense to
5568 * discard data disk but write parity disk
5570 stripe
= stripe
* PAGE_SIZE
;
5571 /* Round up to power of 2, as discard handling
5572 * currently assumes that */
5573 while ((stripe
-1) & stripe
)
5574 stripe
= (stripe
| (stripe
-1)) + 1;
5575 mddev
->queue
->limits
.discard_alignment
= stripe
;
5576 mddev
->queue
->limits
.discard_granularity
= stripe
;
5578 * unaligned part of discard request will be ignored, so can't
5579 * guarantee discard_zerors_data
5581 mddev
->queue
->limits
.discard_zeroes_data
= 0;
5583 rdev_for_each(rdev
, mddev
) {
5584 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5585 rdev
->data_offset
<< 9);
5586 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5587 rdev
->new_data_offset
<< 9);
5589 * discard_zeroes_data is required, otherwise data
5590 * could be lost. Consider a scenario: discard a stripe
5591 * (the stripe could be inconsistent if
5592 * discard_zeroes_data is 0); write one disk of the
5593 * stripe (the stripe could be inconsistent again
5594 * depending on which disks are used to calculate
5595 * parity); the disk is broken; The stripe data of this
5598 if (!blk_queue_discard(bdev_get_queue(rdev
->bdev
)) ||
5599 !bdev_get_queue(rdev
->bdev
)->
5600 limits
.discard_zeroes_data
)
5601 discard_supported
= false;
5604 if (discard_supported
&&
5605 mddev
->queue
->limits
.max_discard_sectors
>= stripe
&&
5606 mddev
->queue
->limits
.discard_granularity
>= stripe
)
5607 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
5610 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
5616 md_unregister_thread(&mddev
->thread
);
5617 print_raid5_conf(conf
);
5619 mddev
->private = NULL
;
5620 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5624 static int stop(struct mddev
*mddev
)
5626 struct r5conf
*conf
= mddev
->private;
5628 md_unregister_thread(&mddev
->thread
);
5630 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5632 mddev
->private = NULL
;
5633 mddev
->to_remove
= &raid5_attrs_group
;
5637 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5639 struct r5conf
*conf
= mddev
->private;
5642 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5643 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5644 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5645 for (i
= 0; i
< conf
->raid_disks
; i
++)
5646 seq_printf (seq
, "%s",
5647 conf
->disks
[i
].rdev
&&
5648 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5649 seq_printf (seq
, "]");
5652 static void print_raid5_conf (struct r5conf
*conf
)
5655 struct disk_info
*tmp
;
5657 printk(KERN_DEBUG
"RAID conf printout:\n");
5659 printk("(conf==NULL)\n");
5662 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5664 conf
->raid_disks
- conf
->mddev
->degraded
);
5666 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5667 char b
[BDEVNAME_SIZE
];
5668 tmp
= conf
->disks
+ i
;
5670 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5671 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5672 bdevname(tmp
->rdev
->bdev
, b
));
5676 static int raid5_spare_active(struct mddev
*mddev
)
5679 struct r5conf
*conf
= mddev
->private;
5680 struct disk_info
*tmp
;
5682 unsigned long flags
;
5684 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5685 tmp
= conf
->disks
+ i
;
5686 if (tmp
->replacement
5687 && tmp
->replacement
->recovery_offset
== MaxSector
5688 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5689 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5690 /* Replacement has just become active. */
5692 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5695 /* Replaced device not technically faulty,
5696 * but we need to be sure it gets removed
5697 * and never re-added.
5699 set_bit(Faulty
, &tmp
->rdev
->flags
);
5700 sysfs_notify_dirent_safe(
5701 tmp
->rdev
->sysfs_state
);
5703 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5704 } else if (tmp
->rdev
5705 && tmp
->rdev
->recovery_offset
== MaxSector
5706 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5707 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5709 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5712 spin_lock_irqsave(&conf
->device_lock
, flags
);
5713 mddev
->degraded
= calc_degraded(conf
);
5714 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5715 print_raid5_conf(conf
);
5719 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5721 struct r5conf
*conf
= mddev
->private;
5723 int number
= rdev
->raid_disk
;
5724 struct md_rdev
**rdevp
;
5725 struct disk_info
*p
= conf
->disks
+ number
;
5727 print_raid5_conf(conf
);
5728 if (rdev
== p
->rdev
)
5730 else if (rdev
== p
->replacement
)
5731 rdevp
= &p
->replacement
;
5735 if (number
>= conf
->raid_disks
&&
5736 conf
->reshape_progress
== MaxSector
)
5737 clear_bit(In_sync
, &rdev
->flags
);
5739 if (test_bit(In_sync
, &rdev
->flags
) ||
5740 atomic_read(&rdev
->nr_pending
)) {
5744 /* Only remove non-faulty devices if recovery
5747 if (!test_bit(Faulty
, &rdev
->flags
) &&
5748 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5749 !has_failed(conf
) &&
5750 (!p
->replacement
|| p
->replacement
== rdev
) &&
5751 number
< conf
->raid_disks
) {
5757 if (atomic_read(&rdev
->nr_pending
)) {
5758 /* lost the race, try later */
5761 } else if (p
->replacement
) {
5762 /* We must have just cleared 'rdev' */
5763 p
->rdev
= p
->replacement
;
5764 clear_bit(Replacement
, &p
->replacement
->flags
);
5765 smp_mb(); /* Make sure other CPUs may see both as identical
5766 * but will never see neither - if they are careful
5768 p
->replacement
= NULL
;
5769 clear_bit(WantReplacement
, &rdev
->flags
);
5771 /* We might have just removed the Replacement as faulty-
5772 * clear the bit just in case
5774 clear_bit(WantReplacement
, &rdev
->flags
);
5777 print_raid5_conf(conf
);
5781 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5783 struct r5conf
*conf
= mddev
->private;
5786 struct disk_info
*p
;
5788 int last
= conf
->raid_disks
- 1;
5790 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5793 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5794 /* no point adding a device */
5797 if (rdev
->raid_disk
>= 0)
5798 first
= last
= rdev
->raid_disk
;
5801 * find the disk ... but prefer rdev->saved_raid_disk
5804 if (rdev
->saved_raid_disk
>= 0 &&
5805 rdev
->saved_raid_disk
>= first
&&
5806 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5807 first
= rdev
->saved_raid_disk
;
5809 for (disk
= first
; disk
<= last
; disk
++) {
5810 p
= conf
->disks
+ disk
;
5811 if (p
->rdev
== NULL
) {
5812 clear_bit(In_sync
, &rdev
->flags
);
5813 rdev
->raid_disk
= disk
;
5815 if (rdev
->saved_raid_disk
!= disk
)
5817 rcu_assign_pointer(p
->rdev
, rdev
);
5821 for (disk
= first
; disk
<= last
; disk
++) {
5822 p
= conf
->disks
+ disk
;
5823 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5824 p
->replacement
== NULL
) {
5825 clear_bit(In_sync
, &rdev
->flags
);
5826 set_bit(Replacement
, &rdev
->flags
);
5827 rdev
->raid_disk
= disk
;
5830 rcu_assign_pointer(p
->replacement
, rdev
);
5835 print_raid5_conf(conf
);
5839 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5841 /* no resync is happening, and there is enough space
5842 * on all devices, so we can resize.
5843 * We need to make sure resync covers any new space.
5844 * If the array is shrinking we should possibly wait until
5845 * any io in the removed space completes, but it hardly seems
5849 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5850 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5851 if (mddev
->external_size
&&
5852 mddev
->array_sectors
> newsize
)
5854 if (mddev
->bitmap
) {
5855 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5859 md_set_array_sectors(mddev
, newsize
);
5860 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5861 revalidate_disk(mddev
->gendisk
);
5862 if (sectors
> mddev
->dev_sectors
&&
5863 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5864 mddev
->recovery_cp
= mddev
->dev_sectors
;
5865 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5867 mddev
->dev_sectors
= sectors
;
5868 mddev
->resync_max_sectors
= sectors
;
5872 static int check_stripe_cache(struct mddev
*mddev
)
5874 /* Can only proceed if there are plenty of stripe_heads.
5875 * We need a minimum of one full stripe,, and for sensible progress
5876 * it is best to have about 4 times that.
5877 * If we require 4 times, then the default 256 4K stripe_heads will
5878 * allow for chunk sizes up to 256K, which is probably OK.
5879 * If the chunk size is greater, user-space should request more
5880 * stripe_heads first.
5882 struct r5conf
*conf
= mddev
->private;
5883 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5884 > conf
->max_nr_stripes
||
5885 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5886 > conf
->max_nr_stripes
) {
5887 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5889 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5896 static int check_reshape(struct mddev
*mddev
)
5898 struct r5conf
*conf
= mddev
->private;
5900 if (mddev
->delta_disks
== 0 &&
5901 mddev
->new_layout
== mddev
->layout
&&
5902 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5903 return 0; /* nothing to do */
5904 if (has_failed(conf
))
5906 if (mddev
->delta_disks
< 0) {
5907 /* We might be able to shrink, but the devices must
5908 * be made bigger first.
5909 * For raid6, 4 is the minimum size.
5910 * Otherwise 2 is the minimum
5913 if (mddev
->level
== 6)
5915 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5919 if (!check_stripe_cache(mddev
))
5922 return resize_stripes(conf
, (conf
->previous_raid_disks
5923 + mddev
->delta_disks
));
5926 static int raid5_start_reshape(struct mddev
*mddev
)
5928 struct r5conf
*conf
= mddev
->private;
5929 struct md_rdev
*rdev
;
5931 unsigned long flags
;
5933 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5936 if (!check_stripe_cache(mddev
))
5939 if (has_failed(conf
))
5942 rdev_for_each(rdev
, mddev
) {
5943 if (!test_bit(In_sync
, &rdev
->flags
)
5944 && !test_bit(Faulty
, &rdev
->flags
))
5948 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5949 /* Not enough devices even to make a degraded array
5954 /* Refuse to reduce size of the array. Any reductions in
5955 * array size must be through explicit setting of array_size
5958 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5959 < mddev
->array_sectors
) {
5960 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5961 "before number of disks\n", mdname(mddev
));
5965 atomic_set(&conf
->reshape_stripes
, 0);
5966 spin_lock_irq(&conf
->device_lock
);
5967 conf
->previous_raid_disks
= conf
->raid_disks
;
5968 conf
->raid_disks
+= mddev
->delta_disks
;
5969 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5970 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5971 conf
->prev_algo
= conf
->algorithm
;
5972 conf
->algorithm
= mddev
->new_layout
;
5974 /* Code that selects data_offset needs to see the generation update
5975 * if reshape_progress has been set - so a memory barrier needed.
5978 if (mddev
->reshape_backwards
)
5979 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5981 conf
->reshape_progress
= 0;
5982 conf
->reshape_safe
= conf
->reshape_progress
;
5983 spin_unlock_irq(&conf
->device_lock
);
5985 /* Add some new drives, as many as will fit.
5986 * We know there are enough to make the newly sized array work.
5987 * Don't add devices if we are reducing the number of
5988 * devices in the array. This is because it is not possible
5989 * to correctly record the "partially reconstructed" state of
5990 * such devices during the reshape and confusion could result.
5992 if (mddev
->delta_disks
>= 0) {
5993 rdev_for_each(rdev
, mddev
)
5994 if (rdev
->raid_disk
< 0 &&
5995 !test_bit(Faulty
, &rdev
->flags
)) {
5996 if (raid5_add_disk(mddev
, rdev
) == 0) {
5998 >= conf
->previous_raid_disks
)
5999 set_bit(In_sync
, &rdev
->flags
);
6001 rdev
->recovery_offset
= 0;
6003 if (sysfs_link_rdev(mddev
, rdev
))
6004 /* Failure here is OK */;
6006 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
6007 && !test_bit(Faulty
, &rdev
->flags
)) {
6008 /* This is a spare that was manually added */
6009 set_bit(In_sync
, &rdev
->flags
);
6012 /* When a reshape changes the number of devices,
6013 * ->degraded is measured against the larger of the
6014 * pre and post number of devices.
6016 spin_lock_irqsave(&conf
->device_lock
, flags
);
6017 mddev
->degraded
= calc_degraded(conf
);
6018 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
6020 mddev
->raid_disks
= conf
->raid_disks
;
6021 mddev
->reshape_position
= conf
->reshape_progress
;
6022 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6024 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
6025 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
6026 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
6027 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
6028 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
6030 if (!mddev
->sync_thread
) {
6031 mddev
->recovery
= 0;
6032 spin_lock_irq(&conf
->device_lock
);
6033 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
6034 rdev_for_each(rdev
, mddev
)
6035 rdev
->new_data_offset
= rdev
->data_offset
;
6037 conf
->reshape_progress
= MaxSector
;
6038 mddev
->reshape_position
= MaxSector
;
6039 spin_unlock_irq(&conf
->device_lock
);
6042 conf
->reshape_checkpoint
= jiffies
;
6043 md_wakeup_thread(mddev
->sync_thread
);
6044 md_new_event(mddev
);
6048 /* This is called from the reshape thread and should make any
6049 * changes needed in 'conf'
6051 static void end_reshape(struct r5conf
*conf
)
6054 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
6055 struct md_rdev
*rdev
;
6057 spin_lock_irq(&conf
->device_lock
);
6058 conf
->previous_raid_disks
= conf
->raid_disks
;
6059 rdev_for_each(rdev
, conf
->mddev
)
6060 rdev
->data_offset
= rdev
->new_data_offset
;
6062 conf
->reshape_progress
= MaxSector
;
6063 spin_unlock_irq(&conf
->device_lock
);
6064 wake_up(&conf
->wait_for_overlap
);
6066 /* read-ahead size must cover two whole stripes, which is
6067 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6069 if (conf
->mddev
->queue
) {
6070 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
6071 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
6073 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
6074 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
6079 /* This is called from the raid5d thread with mddev_lock held.
6080 * It makes config changes to the device.
6082 static void raid5_finish_reshape(struct mddev
*mddev
)
6084 struct r5conf
*conf
= mddev
->private;
6086 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
6088 if (mddev
->delta_disks
> 0) {
6089 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
6090 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
6091 revalidate_disk(mddev
->gendisk
);
6094 spin_lock_irq(&conf
->device_lock
);
6095 mddev
->degraded
= calc_degraded(conf
);
6096 spin_unlock_irq(&conf
->device_lock
);
6097 for (d
= conf
->raid_disks
;
6098 d
< conf
->raid_disks
- mddev
->delta_disks
;
6100 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
6102 clear_bit(In_sync
, &rdev
->flags
);
6103 rdev
= conf
->disks
[d
].replacement
;
6105 clear_bit(In_sync
, &rdev
->flags
);
6108 mddev
->layout
= conf
->algorithm
;
6109 mddev
->chunk_sectors
= conf
->chunk_sectors
;
6110 mddev
->reshape_position
= MaxSector
;
6111 mddev
->delta_disks
= 0;
6112 mddev
->reshape_backwards
= 0;
6116 static void raid5_quiesce(struct mddev
*mddev
, int state
)
6118 struct r5conf
*conf
= mddev
->private;
6121 case 2: /* resume for a suspend */
6122 wake_up(&conf
->wait_for_overlap
);
6125 case 1: /* stop all writes */
6126 spin_lock_irq(&conf
->device_lock
);
6127 /* '2' tells resync/reshape to pause so that all
6128 * active stripes can drain
6131 wait_event_lock_irq(conf
->wait_for_stripe
,
6132 atomic_read(&conf
->active_stripes
) == 0 &&
6133 atomic_read(&conf
->active_aligned_reads
) == 0,
6136 spin_unlock_irq(&conf
->device_lock
);
6137 /* allow reshape to continue */
6138 wake_up(&conf
->wait_for_overlap
);
6141 case 0: /* re-enable writes */
6142 spin_lock_irq(&conf
->device_lock
);
6144 wake_up(&conf
->wait_for_stripe
);
6145 wake_up(&conf
->wait_for_overlap
);
6146 spin_unlock_irq(&conf
->device_lock
);
6152 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
6154 struct r0conf
*raid0_conf
= mddev
->private;
6157 /* for raid0 takeover only one zone is supported */
6158 if (raid0_conf
->nr_strip_zones
> 1) {
6159 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6161 return ERR_PTR(-EINVAL
);
6164 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
6165 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
6166 mddev
->dev_sectors
= sectors
;
6167 mddev
->new_level
= level
;
6168 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6169 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
6170 mddev
->raid_disks
+= 1;
6171 mddev
->delta_disks
= 1;
6172 /* make sure it will be not marked as dirty */
6173 mddev
->recovery_cp
= MaxSector
;
6175 return setup_conf(mddev
);
6179 static void *raid5_takeover_raid1(struct mddev
*mddev
)
6183 if (mddev
->raid_disks
!= 2 ||
6184 mddev
->degraded
> 1)
6185 return ERR_PTR(-EINVAL
);
6187 /* Should check if there are write-behind devices? */
6189 chunksect
= 64*2; /* 64K by default */
6191 /* The array must be an exact multiple of chunksize */
6192 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
6195 if ((chunksect
<<9) < STRIPE_SIZE
)
6196 /* array size does not allow a suitable chunk size */
6197 return ERR_PTR(-EINVAL
);
6199 mddev
->new_level
= 5;
6200 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6201 mddev
->new_chunk_sectors
= chunksect
;
6203 return setup_conf(mddev
);
6206 static void *raid5_takeover_raid6(struct mddev
*mddev
)
6210 switch (mddev
->layout
) {
6211 case ALGORITHM_LEFT_ASYMMETRIC_6
:
6212 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
6214 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
6215 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
6217 case ALGORITHM_LEFT_SYMMETRIC_6
:
6218 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6220 case ALGORITHM_RIGHT_SYMMETRIC_6
:
6221 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
6223 case ALGORITHM_PARITY_0_6
:
6224 new_layout
= ALGORITHM_PARITY_0
;
6226 case ALGORITHM_PARITY_N
:
6227 new_layout
= ALGORITHM_PARITY_N
;
6230 return ERR_PTR(-EINVAL
);
6232 mddev
->new_level
= 5;
6233 mddev
->new_layout
= new_layout
;
6234 mddev
->delta_disks
= -1;
6235 mddev
->raid_disks
-= 1;
6236 return setup_conf(mddev
);
6240 static int raid5_check_reshape(struct mddev
*mddev
)
6242 /* For a 2-drive array, the layout and chunk size can be changed
6243 * immediately as not restriping is needed.
6244 * For larger arrays we record the new value - after validation
6245 * to be used by a reshape pass.
6247 struct r5conf
*conf
= mddev
->private;
6248 int new_chunk
= mddev
->new_chunk_sectors
;
6250 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
6252 if (new_chunk
> 0) {
6253 if (!is_power_of_2(new_chunk
))
6255 if (new_chunk
< (PAGE_SIZE
>>9))
6257 if (mddev
->array_sectors
& (new_chunk
-1))
6258 /* not factor of array size */
6262 /* They look valid */
6264 if (mddev
->raid_disks
== 2) {
6265 /* can make the change immediately */
6266 if (mddev
->new_layout
>= 0) {
6267 conf
->algorithm
= mddev
->new_layout
;
6268 mddev
->layout
= mddev
->new_layout
;
6270 if (new_chunk
> 0) {
6271 conf
->chunk_sectors
= new_chunk
;
6272 mddev
->chunk_sectors
= new_chunk
;
6274 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6275 md_wakeup_thread(mddev
->thread
);
6277 return check_reshape(mddev
);
6280 static int raid6_check_reshape(struct mddev
*mddev
)
6282 int new_chunk
= mddev
->new_chunk_sectors
;
6284 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
6286 if (new_chunk
> 0) {
6287 if (!is_power_of_2(new_chunk
))
6289 if (new_chunk
< (PAGE_SIZE
>> 9))
6291 if (mddev
->array_sectors
& (new_chunk
-1))
6292 /* not factor of array size */
6296 /* They look valid */
6297 return check_reshape(mddev
);
6300 static void *raid5_takeover(struct mddev
*mddev
)
6302 /* raid5 can take over:
6303 * raid0 - if there is only one strip zone - make it a raid4 layout
6304 * raid1 - if there are two drives. We need to know the chunk size
6305 * raid4 - trivial - just use a raid4 layout.
6306 * raid6 - Providing it is a *_6 layout
6308 if (mddev
->level
== 0)
6309 return raid45_takeover_raid0(mddev
, 5);
6310 if (mddev
->level
== 1)
6311 return raid5_takeover_raid1(mddev
);
6312 if (mddev
->level
== 4) {
6313 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6314 mddev
->new_level
= 5;
6315 return setup_conf(mddev
);
6317 if (mddev
->level
== 6)
6318 return raid5_takeover_raid6(mddev
);
6320 return ERR_PTR(-EINVAL
);
6323 static void *raid4_takeover(struct mddev
*mddev
)
6325 /* raid4 can take over:
6326 * raid0 - if there is only one strip zone
6327 * raid5 - if layout is right
6329 if (mddev
->level
== 0)
6330 return raid45_takeover_raid0(mddev
, 4);
6331 if (mddev
->level
== 5 &&
6332 mddev
->layout
== ALGORITHM_PARITY_N
) {
6333 mddev
->new_layout
= 0;
6334 mddev
->new_level
= 4;
6335 return setup_conf(mddev
);
6337 return ERR_PTR(-EINVAL
);
6340 static struct md_personality raid5_personality
;
6342 static void *raid6_takeover(struct mddev
*mddev
)
6344 /* Currently can only take over a raid5. We map the
6345 * personality to an equivalent raid6 personality
6346 * with the Q block at the end.
6350 if (mddev
->pers
!= &raid5_personality
)
6351 return ERR_PTR(-EINVAL
);
6352 if (mddev
->degraded
> 1)
6353 return ERR_PTR(-EINVAL
);
6354 if (mddev
->raid_disks
> 253)
6355 return ERR_PTR(-EINVAL
);
6356 if (mddev
->raid_disks
< 3)
6357 return ERR_PTR(-EINVAL
);
6359 switch (mddev
->layout
) {
6360 case ALGORITHM_LEFT_ASYMMETRIC
:
6361 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6363 case ALGORITHM_RIGHT_ASYMMETRIC
:
6364 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6366 case ALGORITHM_LEFT_SYMMETRIC
:
6367 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6369 case ALGORITHM_RIGHT_SYMMETRIC
:
6370 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6372 case ALGORITHM_PARITY_0
:
6373 new_layout
= ALGORITHM_PARITY_0_6
;
6375 case ALGORITHM_PARITY_N
:
6376 new_layout
= ALGORITHM_PARITY_N
;
6379 return ERR_PTR(-EINVAL
);
6381 mddev
->new_level
= 6;
6382 mddev
->new_layout
= new_layout
;
6383 mddev
->delta_disks
= 1;
6384 mddev
->raid_disks
+= 1;
6385 return setup_conf(mddev
);
6389 static struct md_personality raid6_personality
=
6393 .owner
= THIS_MODULE
,
6394 .make_request
= make_request
,
6398 .error_handler
= error
,
6399 .hot_add_disk
= raid5_add_disk
,
6400 .hot_remove_disk
= raid5_remove_disk
,
6401 .spare_active
= raid5_spare_active
,
6402 .sync_request
= sync_request
,
6403 .resize
= raid5_resize
,
6405 .check_reshape
= raid6_check_reshape
,
6406 .start_reshape
= raid5_start_reshape
,
6407 .finish_reshape
= raid5_finish_reshape
,
6408 .quiesce
= raid5_quiesce
,
6409 .takeover
= raid6_takeover
,
6411 static struct md_personality raid5_personality
=
6415 .owner
= THIS_MODULE
,
6416 .make_request
= make_request
,
6420 .error_handler
= error
,
6421 .hot_add_disk
= raid5_add_disk
,
6422 .hot_remove_disk
= raid5_remove_disk
,
6423 .spare_active
= raid5_spare_active
,
6424 .sync_request
= sync_request
,
6425 .resize
= raid5_resize
,
6427 .check_reshape
= raid5_check_reshape
,
6428 .start_reshape
= raid5_start_reshape
,
6429 .finish_reshape
= raid5_finish_reshape
,
6430 .quiesce
= raid5_quiesce
,
6431 .takeover
= raid5_takeover
,
6434 static struct md_personality raid4_personality
=
6438 .owner
= THIS_MODULE
,
6439 .make_request
= make_request
,
6443 .error_handler
= error
,
6444 .hot_add_disk
= raid5_add_disk
,
6445 .hot_remove_disk
= raid5_remove_disk
,
6446 .spare_active
= raid5_spare_active
,
6447 .sync_request
= sync_request
,
6448 .resize
= raid5_resize
,
6450 .check_reshape
= raid5_check_reshape
,
6451 .start_reshape
= raid5_start_reshape
,
6452 .finish_reshape
= raid5_finish_reshape
,
6453 .quiesce
= raid5_quiesce
,
6454 .takeover
= raid4_takeover
,
6457 static int __init
raid5_init(void)
6459 register_md_personality(&raid6_personality
);
6460 register_md_personality(&raid5_personality
);
6461 register_md_personality(&raid4_personality
);
6465 static void raid5_exit(void)
6467 unregister_md_personality(&raid6_personality
);
6468 unregister_md_personality(&raid5_personality
);
6469 unregister_md_personality(&raid4_personality
);
6472 module_init(raid5_init
);
6473 module_exit(raid5_exit
);
6474 MODULE_LICENSE("GPL");
6475 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6476 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6477 MODULE_ALIAS("md-raid5");
6478 MODULE_ALIAS("md-raid4");
6479 MODULE_ALIAS("md-level-5");
6480 MODULE_ALIAS("md-level-4");
6481 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6482 MODULE_ALIAS("md-raid6");
6483 MODULE_ALIAS("md-level-6");
6485 /* This used to be two separate modules, they were: */
6486 MODULE_ALIAS("raid5");
6487 MODULE_ALIAS("raid6");