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
);
676 trace_block_bio_remap(bdev_get_queue(bi
->bi_bdev
),
677 bi
, disk_devt(conf
->mddev
->gendisk
),
679 generic_make_request(bi
);
682 if (s
->syncing
|| s
->expanding
|| s
->expanded
684 md_sync_acct(rrdev
->bdev
, STRIPE_SECTORS
);
686 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
688 rbi
->bi_bdev
= rrdev
->bdev
;
689 pr_debug("%s: for %llu schedule op %ld on "
690 "replacement disc %d\n",
691 __func__
, (unsigned long long)sh
->sector
,
693 atomic_inc(&sh
->count
);
694 if (use_new_offset(conf
, sh
))
695 rbi
->bi_sector
= (sh
->sector
696 + rrdev
->new_data_offset
);
698 rbi
->bi_sector
= (sh
->sector
699 + rrdev
->data_offset
);
700 rbi
->bi_flags
= 1 << BIO_UPTODATE
;
702 rbi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
703 rbi
->bi_io_vec
[0].bv_offset
= 0;
704 rbi
->bi_size
= STRIPE_SIZE
;
706 trace_block_bio_remap(bdev_get_queue(rbi
->bi_bdev
),
707 rbi
, disk_devt(conf
->mddev
->gendisk
),
709 generic_make_request(rbi
);
711 if (!rdev
&& !rrdev
) {
713 set_bit(STRIPE_DEGRADED
, &sh
->state
);
714 pr_debug("skip op %ld on disc %d for sector %llu\n",
715 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
716 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
717 set_bit(STRIPE_HANDLE
, &sh
->state
);
722 static struct dma_async_tx_descriptor
*
723 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
724 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
727 struct page
*bio_page
;
730 struct async_submit_ctl submit
;
731 enum async_tx_flags flags
= 0;
733 if (bio
->bi_sector
>= sector
)
734 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
736 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
739 flags
|= ASYNC_TX_FENCE
;
740 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
742 bio_for_each_segment(bvl
, bio
, i
) {
743 int len
= bvl
->bv_len
;
747 if (page_offset
< 0) {
748 b_offset
= -page_offset
;
749 page_offset
+= b_offset
;
753 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
754 clen
= STRIPE_SIZE
- page_offset
;
759 b_offset
+= bvl
->bv_offset
;
760 bio_page
= bvl
->bv_page
;
762 tx
= async_memcpy(page
, bio_page
, page_offset
,
763 b_offset
, clen
, &submit
);
765 tx
= async_memcpy(bio_page
, page
, b_offset
,
766 page_offset
, clen
, &submit
);
768 /* chain the operations */
769 submit
.depend_tx
= tx
;
771 if (clen
< len
) /* hit end of page */
779 static void ops_complete_biofill(void *stripe_head_ref
)
781 struct stripe_head
*sh
= stripe_head_ref
;
782 struct bio
*return_bi
= NULL
;
785 pr_debug("%s: stripe %llu\n", __func__
,
786 (unsigned long long)sh
->sector
);
788 /* clear completed biofills */
789 for (i
= sh
->disks
; i
--; ) {
790 struct r5dev
*dev
= &sh
->dev
[i
];
792 /* acknowledge completion of a biofill operation */
793 /* and check if we need to reply to a read request,
794 * new R5_Wantfill requests are held off until
795 * !STRIPE_BIOFILL_RUN
797 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
798 struct bio
*rbi
, *rbi2
;
803 while (rbi
&& rbi
->bi_sector
<
804 dev
->sector
+ STRIPE_SECTORS
) {
805 rbi2
= r5_next_bio(rbi
, dev
->sector
);
806 if (!raid5_dec_bi_active_stripes(rbi
)) {
807 rbi
->bi_next
= return_bi
;
814 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
816 return_io(return_bi
);
818 set_bit(STRIPE_HANDLE
, &sh
->state
);
822 static void ops_run_biofill(struct stripe_head
*sh
)
824 struct dma_async_tx_descriptor
*tx
= NULL
;
825 struct async_submit_ctl submit
;
828 pr_debug("%s: stripe %llu\n", __func__
,
829 (unsigned long long)sh
->sector
);
831 for (i
= sh
->disks
; i
--; ) {
832 struct r5dev
*dev
= &sh
->dev
[i
];
833 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
835 spin_lock_irq(&sh
->stripe_lock
);
836 dev
->read
= rbi
= dev
->toread
;
838 spin_unlock_irq(&sh
->stripe_lock
);
839 while (rbi
&& rbi
->bi_sector
<
840 dev
->sector
+ STRIPE_SECTORS
) {
841 tx
= async_copy_data(0, rbi
, dev
->page
,
843 rbi
= r5_next_bio(rbi
, dev
->sector
);
848 atomic_inc(&sh
->count
);
849 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
850 async_trigger_callback(&submit
);
853 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
860 tgt
= &sh
->dev
[target
];
861 set_bit(R5_UPTODATE
, &tgt
->flags
);
862 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
863 clear_bit(R5_Wantcompute
, &tgt
->flags
);
866 static void ops_complete_compute(void *stripe_head_ref
)
868 struct stripe_head
*sh
= stripe_head_ref
;
870 pr_debug("%s: stripe %llu\n", __func__
,
871 (unsigned long long)sh
->sector
);
873 /* mark the computed target(s) as uptodate */
874 mark_target_uptodate(sh
, sh
->ops
.target
);
875 mark_target_uptodate(sh
, sh
->ops
.target2
);
877 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
878 if (sh
->check_state
== check_state_compute_run
)
879 sh
->check_state
= check_state_compute_result
;
880 set_bit(STRIPE_HANDLE
, &sh
->state
);
884 /* return a pointer to the address conversion region of the scribble buffer */
885 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
886 struct raid5_percpu
*percpu
)
888 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
891 static struct dma_async_tx_descriptor
*
892 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
894 int disks
= sh
->disks
;
895 struct page
**xor_srcs
= percpu
->scribble
;
896 int target
= sh
->ops
.target
;
897 struct r5dev
*tgt
= &sh
->dev
[target
];
898 struct page
*xor_dest
= tgt
->page
;
900 struct dma_async_tx_descriptor
*tx
;
901 struct async_submit_ctl submit
;
904 pr_debug("%s: stripe %llu block: %d\n",
905 __func__
, (unsigned long long)sh
->sector
, target
);
906 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
908 for (i
= disks
; i
--; )
910 xor_srcs
[count
++] = sh
->dev
[i
].page
;
912 atomic_inc(&sh
->count
);
914 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
915 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
916 if (unlikely(count
== 1))
917 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
919 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
924 /* set_syndrome_sources - populate source buffers for gen_syndrome
925 * @srcs - (struct page *) array of size sh->disks
926 * @sh - stripe_head to parse
928 * Populates srcs in proper layout order for the stripe and returns the
929 * 'count' of sources to be used in a call to async_gen_syndrome. The P
930 * destination buffer is recorded in srcs[count] and the Q destination
931 * is recorded in srcs[count+1]].
933 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
935 int disks
= sh
->disks
;
936 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
937 int d0_idx
= raid6_d0(sh
);
941 for (i
= 0; i
< disks
; i
++)
947 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
949 srcs
[slot
] = sh
->dev
[i
].page
;
950 i
= raid6_next_disk(i
, disks
);
951 } while (i
!= d0_idx
);
953 return syndrome_disks
;
956 static struct dma_async_tx_descriptor
*
957 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
959 int disks
= sh
->disks
;
960 struct page
**blocks
= percpu
->scribble
;
962 int qd_idx
= sh
->qd_idx
;
963 struct dma_async_tx_descriptor
*tx
;
964 struct async_submit_ctl submit
;
970 if (sh
->ops
.target
< 0)
971 target
= sh
->ops
.target2
;
972 else if (sh
->ops
.target2
< 0)
973 target
= sh
->ops
.target
;
975 /* we should only have one valid target */
978 pr_debug("%s: stripe %llu block: %d\n",
979 __func__
, (unsigned long long)sh
->sector
, target
);
981 tgt
= &sh
->dev
[target
];
982 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
985 atomic_inc(&sh
->count
);
987 if (target
== qd_idx
) {
988 count
= set_syndrome_sources(blocks
, sh
);
989 blocks
[count
] = NULL
; /* regenerating p is not necessary */
990 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
991 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
992 ops_complete_compute
, sh
,
993 to_addr_conv(sh
, percpu
));
994 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
996 /* Compute any data- or p-drive using XOR */
998 for (i
= disks
; i
-- ; ) {
999 if (i
== target
|| i
== qd_idx
)
1001 blocks
[count
++] = sh
->dev
[i
].page
;
1004 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1005 NULL
, ops_complete_compute
, sh
,
1006 to_addr_conv(sh
, percpu
));
1007 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
1013 static struct dma_async_tx_descriptor
*
1014 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1016 int i
, count
, disks
= sh
->disks
;
1017 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
1018 int d0_idx
= raid6_d0(sh
);
1019 int faila
= -1, failb
= -1;
1020 int target
= sh
->ops
.target
;
1021 int target2
= sh
->ops
.target2
;
1022 struct r5dev
*tgt
= &sh
->dev
[target
];
1023 struct r5dev
*tgt2
= &sh
->dev
[target2
];
1024 struct dma_async_tx_descriptor
*tx
;
1025 struct page
**blocks
= percpu
->scribble
;
1026 struct async_submit_ctl submit
;
1028 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
1029 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
1030 BUG_ON(target
< 0 || target2
< 0);
1031 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
1032 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
1034 /* we need to open-code set_syndrome_sources to handle the
1035 * slot number conversion for 'faila' and 'failb'
1037 for (i
= 0; i
< disks
; i
++)
1042 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
1044 blocks
[slot
] = sh
->dev
[i
].page
;
1050 i
= raid6_next_disk(i
, disks
);
1051 } while (i
!= d0_idx
);
1053 BUG_ON(faila
== failb
);
1056 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
1057 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
1059 atomic_inc(&sh
->count
);
1061 if (failb
== syndrome_disks
+1) {
1062 /* Q disk is one of the missing disks */
1063 if (faila
== syndrome_disks
) {
1064 /* Missing P+Q, just recompute */
1065 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1066 ops_complete_compute
, sh
,
1067 to_addr_conv(sh
, percpu
));
1068 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
1069 STRIPE_SIZE
, &submit
);
1073 int qd_idx
= sh
->qd_idx
;
1075 /* Missing D+Q: recompute D from P, then recompute Q */
1076 if (target
== qd_idx
)
1077 data_target
= target2
;
1079 data_target
= target
;
1082 for (i
= disks
; i
-- ; ) {
1083 if (i
== data_target
|| i
== qd_idx
)
1085 blocks
[count
++] = sh
->dev
[i
].page
;
1087 dest
= sh
->dev
[data_target
].page
;
1088 init_async_submit(&submit
,
1089 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
1091 to_addr_conv(sh
, percpu
));
1092 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
1095 count
= set_syndrome_sources(blocks
, sh
);
1096 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
1097 ops_complete_compute
, sh
,
1098 to_addr_conv(sh
, percpu
));
1099 return async_gen_syndrome(blocks
, 0, count
+2,
1100 STRIPE_SIZE
, &submit
);
1103 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
1104 ops_complete_compute
, sh
,
1105 to_addr_conv(sh
, percpu
));
1106 if (failb
== syndrome_disks
) {
1107 /* We're missing D+P. */
1108 return async_raid6_datap_recov(syndrome_disks
+2,
1112 /* We're missing D+D. */
1113 return async_raid6_2data_recov(syndrome_disks
+2,
1114 STRIPE_SIZE
, faila
, failb
,
1121 static void ops_complete_prexor(void *stripe_head_ref
)
1123 struct stripe_head
*sh
= stripe_head_ref
;
1125 pr_debug("%s: stripe %llu\n", __func__
,
1126 (unsigned long long)sh
->sector
);
1129 static struct dma_async_tx_descriptor
*
1130 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1131 struct dma_async_tx_descriptor
*tx
)
1133 int disks
= sh
->disks
;
1134 struct page
**xor_srcs
= percpu
->scribble
;
1135 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1136 struct async_submit_ctl submit
;
1138 /* existing parity data subtracted */
1139 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1141 pr_debug("%s: stripe %llu\n", __func__
,
1142 (unsigned long long)sh
->sector
);
1144 for (i
= disks
; i
--; ) {
1145 struct r5dev
*dev
= &sh
->dev
[i
];
1146 /* Only process blocks that are known to be uptodate */
1147 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1148 xor_srcs
[count
++] = dev
->page
;
1151 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1152 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1153 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1158 static struct dma_async_tx_descriptor
*
1159 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1161 int disks
= sh
->disks
;
1164 pr_debug("%s: stripe %llu\n", __func__
,
1165 (unsigned long long)sh
->sector
);
1167 for (i
= disks
; i
--; ) {
1168 struct r5dev
*dev
= &sh
->dev
[i
];
1171 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1174 spin_lock_irq(&sh
->stripe_lock
);
1175 chosen
= dev
->towrite
;
1176 dev
->towrite
= NULL
;
1177 BUG_ON(dev
->written
);
1178 wbi
= dev
->written
= chosen
;
1179 spin_unlock_irq(&sh
->stripe_lock
);
1181 while (wbi
&& wbi
->bi_sector
<
1182 dev
->sector
+ STRIPE_SECTORS
) {
1183 if (wbi
->bi_rw
& REQ_FUA
)
1184 set_bit(R5_WantFUA
, &dev
->flags
);
1185 if (wbi
->bi_rw
& REQ_SYNC
)
1186 set_bit(R5_SyncIO
, &dev
->flags
);
1187 if (wbi
->bi_rw
& REQ_DISCARD
)
1188 set_bit(R5_Discard
, &dev
->flags
);
1190 tx
= async_copy_data(1, wbi
, dev
->page
,
1192 wbi
= r5_next_bio(wbi
, dev
->sector
);
1200 static void ops_complete_reconstruct(void *stripe_head_ref
)
1202 struct stripe_head
*sh
= stripe_head_ref
;
1203 int disks
= sh
->disks
;
1204 int pd_idx
= sh
->pd_idx
;
1205 int qd_idx
= sh
->qd_idx
;
1207 bool fua
= false, sync
= false, discard
= false;
1209 pr_debug("%s: stripe %llu\n", __func__
,
1210 (unsigned long long)sh
->sector
);
1212 for (i
= disks
; i
--; ) {
1213 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1214 sync
|= test_bit(R5_SyncIO
, &sh
->dev
[i
].flags
);
1215 discard
|= test_bit(R5_Discard
, &sh
->dev
[i
].flags
);
1218 for (i
= disks
; i
--; ) {
1219 struct r5dev
*dev
= &sh
->dev
[i
];
1221 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1223 set_bit(R5_UPTODATE
, &dev
->flags
);
1225 set_bit(R5_WantFUA
, &dev
->flags
);
1227 set_bit(R5_SyncIO
, &dev
->flags
);
1231 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1232 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1233 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1234 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1236 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1237 sh
->reconstruct_state
= reconstruct_state_result
;
1240 set_bit(STRIPE_HANDLE
, &sh
->state
);
1245 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1246 struct dma_async_tx_descriptor
*tx
)
1248 int disks
= sh
->disks
;
1249 struct page
**xor_srcs
= percpu
->scribble
;
1250 struct async_submit_ctl submit
;
1251 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1252 struct page
*xor_dest
;
1254 unsigned long flags
;
1256 pr_debug("%s: stripe %llu\n", __func__
,
1257 (unsigned long long)sh
->sector
);
1259 for (i
= 0; i
< sh
->disks
; i
++) {
1262 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1265 if (i
>= sh
->disks
) {
1266 atomic_inc(&sh
->count
);
1267 set_bit(R5_Discard
, &sh
->dev
[pd_idx
].flags
);
1268 ops_complete_reconstruct(sh
);
1271 /* check if prexor is active which means only process blocks
1272 * that are part of a read-modify-write (written)
1274 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1276 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1277 for (i
= disks
; i
--; ) {
1278 struct r5dev
*dev
= &sh
->dev
[i
];
1280 xor_srcs
[count
++] = dev
->page
;
1283 xor_dest
= sh
->dev
[pd_idx
].page
;
1284 for (i
= disks
; i
--; ) {
1285 struct r5dev
*dev
= &sh
->dev
[i
];
1287 xor_srcs
[count
++] = dev
->page
;
1291 /* 1/ if we prexor'd then the dest is reused as a source
1292 * 2/ if we did not prexor then we are redoing the parity
1293 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1294 * for the synchronous xor case
1296 flags
= ASYNC_TX_ACK
|
1297 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1299 atomic_inc(&sh
->count
);
1301 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1302 to_addr_conv(sh
, percpu
));
1303 if (unlikely(count
== 1))
1304 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1306 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1310 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1311 struct dma_async_tx_descriptor
*tx
)
1313 struct async_submit_ctl submit
;
1314 struct page
**blocks
= percpu
->scribble
;
1317 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1319 for (i
= 0; i
< sh
->disks
; i
++) {
1320 if (sh
->pd_idx
== i
|| sh
->qd_idx
== i
)
1322 if (!test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
1325 if (i
>= sh
->disks
) {
1326 atomic_inc(&sh
->count
);
1327 set_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
);
1328 set_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
);
1329 ops_complete_reconstruct(sh
);
1333 count
= set_syndrome_sources(blocks
, sh
);
1335 atomic_inc(&sh
->count
);
1337 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1338 sh
, to_addr_conv(sh
, percpu
));
1339 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1342 static void ops_complete_check(void *stripe_head_ref
)
1344 struct stripe_head
*sh
= stripe_head_ref
;
1346 pr_debug("%s: stripe %llu\n", __func__
,
1347 (unsigned long long)sh
->sector
);
1349 sh
->check_state
= check_state_check_result
;
1350 set_bit(STRIPE_HANDLE
, &sh
->state
);
1354 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1356 int disks
= sh
->disks
;
1357 int pd_idx
= sh
->pd_idx
;
1358 int qd_idx
= sh
->qd_idx
;
1359 struct page
*xor_dest
;
1360 struct page
**xor_srcs
= percpu
->scribble
;
1361 struct dma_async_tx_descriptor
*tx
;
1362 struct async_submit_ctl submit
;
1366 pr_debug("%s: stripe %llu\n", __func__
,
1367 (unsigned long long)sh
->sector
);
1370 xor_dest
= sh
->dev
[pd_idx
].page
;
1371 xor_srcs
[count
++] = xor_dest
;
1372 for (i
= disks
; i
--; ) {
1373 if (i
== pd_idx
|| i
== qd_idx
)
1375 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1378 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1379 to_addr_conv(sh
, percpu
));
1380 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1381 &sh
->ops
.zero_sum_result
, &submit
);
1383 atomic_inc(&sh
->count
);
1384 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1385 tx
= async_trigger_callback(&submit
);
1388 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1390 struct page
**srcs
= percpu
->scribble
;
1391 struct async_submit_ctl submit
;
1394 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1395 (unsigned long long)sh
->sector
, checkp
);
1397 count
= set_syndrome_sources(srcs
, sh
);
1401 atomic_inc(&sh
->count
);
1402 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1403 sh
, to_addr_conv(sh
, percpu
));
1404 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1405 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1408 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1410 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1411 struct dma_async_tx_descriptor
*tx
= NULL
;
1412 struct r5conf
*conf
= sh
->raid_conf
;
1413 int level
= conf
->level
;
1414 struct raid5_percpu
*percpu
;
1418 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1419 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1420 ops_run_biofill(sh
);
1424 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1426 tx
= ops_run_compute5(sh
, percpu
);
1428 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1429 tx
= ops_run_compute6_1(sh
, percpu
);
1431 tx
= ops_run_compute6_2(sh
, percpu
);
1433 /* terminate the chain if reconstruct is not set to be run */
1434 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1438 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1439 tx
= ops_run_prexor(sh
, percpu
, tx
);
1441 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1442 tx
= ops_run_biodrain(sh
, tx
);
1446 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1448 ops_run_reconstruct5(sh
, percpu
, tx
);
1450 ops_run_reconstruct6(sh
, percpu
, tx
);
1453 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1454 if (sh
->check_state
== check_state_run
)
1455 ops_run_check_p(sh
, percpu
);
1456 else if (sh
->check_state
== check_state_run_q
)
1457 ops_run_check_pq(sh
, percpu
, 0);
1458 else if (sh
->check_state
== check_state_run_pq
)
1459 ops_run_check_pq(sh
, percpu
, 1);
1465 for (i
= disks
; i
--; ) {
1466 struct r5dev
*dev
= &sh
->dev
[i
];
1467 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1468 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1473 #ifdef CONFIG_MULTICORE_RAID456
1474 static void async_run_ops(void *param
, async_cookie_t cookie
)
1476 struct stripe_head
*sh
= param
;
1477 unsigned long ops_request
= sh
->ops
.request
;
1479 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1480 wake_up(&sh
->ops
.wait_for_ops
);
1482 __raid_run_ops(sh
, ops_request
);
1486 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1488 /* since handle_stripe can be called outside of raid5d context
1489 * we need to ensure sh->ops.request is de-staged before another
1492 wait_event(sh
->ops
.wait_for_ops
,
1493 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1494 sh
->ops
.request
= ops_request
;
1496 atomic_inc(&sh
->count
);
1497 async_schedule(async_run_ops
, sh
);
1500 #define raid_run_ops __raid_run_ops
1503 static int grow_one_stripe(struct r5conf
*conf
)
1505 struct stripe_head
*sh
;
1506 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1510 sh
->raid_conf
= conf
;
1511 #ifdef CONFIG_MULTICORE_RAID456
1512 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1515 spin_lock_init(&sh
->stripe_lock
);
1517 if (grow_buffers(sh
)) {
1519 kmem_cache_free(conf
->slab_cache
, sh
);
1522 /* we just created an active stripe so... */
1523 atomic_set(&sh
->count
, 1);
1524 atomic_inc(&conf
->active_stripes
);
1525 INIT_LIST_HEAD(&sh
->lru
);
1530 static int grow_stripes(struct r5conf
*conf
, int num
)
1532 struct kmem_cache
*sc
;
1533 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1535 if (conf
->mddev
->gendisk
)
1536 sprintf(conf
->cache_name
[0],
1537 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1539 sprintf(conf
->cache_name
[0],
1540 "raid%d-%p", conf
->level
, conf
->mddev
);
1541 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1543 conf
->active_name
= 0;
1544 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1545 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1549 conf
->slab_cache
= sc
;
1550 conf
->pool_size
= devs
;
1552 if (!grow_one_stripe(conf
))
1558 * scribble_len - return the required size of the scribble region
1559 * @num - total number of disks in the array
1561 * The size must be enough to contain:
1562 * 1/ a struct page pointer for each device in the array +2
1563 * 2/ room to convert each entry in (1) to its corresponding dma
1564 * (dma_map_page()) or page (page_address()) address.
1566 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1567 * calculate over all devices (not just the data blocks), using zeros in place
1568 * of the P and Q blocks.
1570 static size_t scribble_len(int num
)
1574 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1579 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1581 /* Make all the stripes able to hold 'newsize' devices.
1582 * New slots in each stripe get 'page' set to a new page.
1584 * This happens in stages:
1585 * 1/ create a new kmem_cache and allocate the required number of
1587 * 2/ gather all the old stripe_heads and transfer the pages across
1588 * to the new stripe_heads. This will have the side effect of
1589 * freezing the array as once all stripe_heads have been collected,
1590 * no IO will be possible. Old stripe heads are freed once their
1591 * pages have been transferred over, and the old kmem_cache is
1592 * freed when all stripes are done.
1593 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1594 * we simple return a failre status - no need to clean anything up.
1595 * 4/ allocate new pages for the new slots in the new stripe_heads.
1596 * If this fails, we don't bother trying the shrink the
1597 * stripe_heads down again, we just leave them as they are.
1598 * As each stripe_head is processed the new one is released into
1601 * Once step2 is started, we cannot afford to wait for a write,
1602 * so we use GFP_NOIO allocations.
1604 struct stripe_head
*osh
, *nsh
;
1605 LIST_HEAD(newstripes
);
1606 struct disk_info
*ndisks
;
1609 struct kmem_cache
*sc
;
1612 if (newsize
<= conf
->pool_size
)
1613 return 0; /* never bother to shrink */
1615 err
= md_allow_write(conf
->mddev
);
1620 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1621 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1626 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1627 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1631 nsh
->raid_conf
= conf
;
1632 #ifdef CONFIG_MULTICORE_RAID456
1633 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1635 spin_lock_init(&nsh
->stripe_lock
);
1637 list_add(&nsh
->lru
, &newstripes
);
1640 /* didn't get enough, give up */
1641 while (!list_empty(&newstripes
)) {
1642 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1643 list_del(&nsh
->lru
);
1644 kmem_cache_free(sc
, nsh
);
1646 kmem_cache_destroy(sc
);
1649 /* Step 2 - Must use GFP_NOIO now.
1650 * OK, we have enough stripes, start collecting inactive
1651 * stripes and copying them over
1653 list_for_each_entry(nsh
, &newstripes
, lru
) {
1654 spin_lock_irq(&conf
->device_lock
);
1655 wait_event_lock_irq(conf
->wait_for_stripe
,
1656 !list_empty(&conf
->inactive_list
),
1658 osh
= get_free_stripe(conf
);
1659 spin_unlock_irq(&conf
->device_lock
);
1660 atomic_set(&nsh
->count
, 1);
1661 for(i
=0; i
<conf
->pool_size
; i
++)
1662 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1663 for( ; i
<newsize
; i
++)
1664 nsh
->dev
[i
].page
= NULL
;
1665 kmem_cache_free(conf
->slab_cache
, osh
);
1667 kmem_cache_destroy(conf
->slab_cache
);
1670 * At this point, we are holding all the stripes so the array
1671 * is completely stalled, so now is a good time to resize
1672 * conf->disks and the scribble region
1674 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1676 for (i
=0; i
<conf
->raid_disks
; i
++)
1677 ndisks
[i
] = conf
->disks
[i
];
1679 conf
->disks
= ndisks
;
1684 conf
->scribble_len
= scribble_len(newsize
);
1685 for_each_present_cpu(cpu
) {
1686 struct raid5_percpu
*percpu
;
1689 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1690 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1693 kfree(percpu
->scribble
);
1694 percpu
->scribble
= scribble
;
1702 /* Step 4, return new stripes to service */
1703 while(!list_empty(&newstripes
)) {
1704 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1705 list_del_init(&nsh
->lru
);
1707 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1708 if (nsh
->dev
[i
].page
== NULL
) {
1709 struct page
*p
= alloc_page(GFP_NOIO
);
1710 nsh
->dev
[i
].page
= p
;
1714 release_stripe(nsh
);
1716 /* critical section pass, GFP_NOIO no longer needed */
1718 conf
->slab_cache
= sc
;
1719 conf
->active_name
= 1-conf
->active_name
;
1720 conf
->pool_size
= newsize
;
1724 static int drop_one_stripe(struct r5conf
*conf
)
1726 struct stripe_head
*sh
;
1728 spin_lock_irq(&conf
->device_lock
);
1729 sh
= get_free_stripe(conf
);
1730 spin_unlock_irq(&conf
->device_lock
);
1733 BUG_ON(atomic_read(&sh
->count
));
1735 kmem_cache_free(conf
->slab_cache
, sh
);
1736 atomic_dec(&conf
->active_stripes
);
1740 static void shrink_stripes(struct r5conf
*conf
)
1742 while (drop_one_stripe(conf
))
1745 if (conf
->slab_cache
)
1746 kmem_cache_destroy(conf
->slab_cache
);
1747 conf
->slab_cache
= NULL
;
1750 static void raid5_end_read_request(struct bio
* bi
, int error
)
1752 struct stripe_head
*sh
= bi
->bi_private
;
1753 struct r5conf
*conf
= sh
->raid_conf
;
1754 int disks
= sh
->disks
, i
;
1755 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1756 char b
[BDEVNAME_SIZE
];
1757 struct md_rdev
*rdev
= NULL
;
1760 for (i
=0 ; i
<disks
; i
++)
1761 if (bi
== &sh
->dev
[i
].req
)
1764 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1765 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1771 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1772 /* If replacement finished while this request was outstanding,
1773 * 'replacement' might be NULL already.
1774 * In that case it moved down to 'rdev'.
1775 * rdev is not removed until all requests are finished.
1777 rdev
= conf
->disks
[i
].replacement
;
1779 rdev
= conf
->disks
[i
].rdev
;
1781 if (use_new_offset(conf
, sh
))
1782 s
= sh
->sector
+ rdev
->new_data_offset
;
1784 s
= sh
->sector
+ rdev
->data_offset
;
1786 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1787 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1788 /* Note that this cannot happen on a
1789 * replacement device. We just fail those on
1794 "md/raid:%s: read error corrected"
1795 " (%lu sectors at %llu on %s)\n",
1796 mdname(conf
->mddev
), STRIPE_SECTORS
,
1797 (unsigned long long)s
,
1798 bdevname(rdev
->bdev
, b
));
1799 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1800 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1801 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1802 } else if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
))
1803 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1805 if (atomic_read(&rdev
->read_errors
))
1806 atomic_set(&rdev
->read_errors
, 0);
1808 const char *bdn
= bdevname(rdev
->bdev
, b
);
1812 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1813 atomic_inc(&rdev
->read_errors
);
1814 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1817 "md/raid:%s: read error on replacement device "
1818 "(sector %llu on %s).\n",
1819 mdname(conf
->mddev
),
1820 (unsigned long long)s
,
1822 else if (conf
->mddev
->degraded
>= conf
->max_degraded
) {
1826 "md/raid:%s: read error not correctable "
1827 "(sector %llu on %s).\n",
1828 mdname(conf
->mddev
),
1829 (unsigned long long)s
,
1831 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
1836 "md/raid:%s: read error NOT corrected!! "
1837 "(sector %llu on %s).\n",
1838 mdname(conf
->mddev
),
1839 (unsigned long long)s
,
1841 } else if (atomic_read(&rdev
->read_errors
)
1842 > conf
->max_nr_stripes
)
1844 "md/raid:%s: Too many read errors, failing device %s.\n",
1845 mdname(conf
->mddev
), bdn
);
1849 if (test_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
)) {
1850 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1851 clear_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1853 set_bit(R5_ReadNoMerge
, &sh
->dev
[i
].flags
);
1855 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1856 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1858 && test_bit(In_sync
, &rdev
->flags
)
1859 && rdev_set_badblocks(
1860 rdev
, sh
->sector
, STRIPE_SECTORS
, 0)))
1861 md_error(conf
->mddev
, rdev
);
1864 rdev_dec_pending(rdev
, conf
->mddev
);
1865 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1866 set_bit(STRIPE_HANDLE
, &sh
->state
);
1870 static void raid5_end_write_request(struct bio
*bi
, int error
)
1872 struct stripe_head
*sh
= bi
->bi_private
;
1873 struct r5conf
*conf
= sh
->raid_conf
;
1874 int disks
= sh
->disks
, i
;
1875 struct md_rdev
*uninitialized_var(rdev
);
1876 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1879 int replacement
= 0;
1881 for (i
= 0 ; i
< disks
; i
++) {
1882 if (bi
== &sh
->dev
[i
].req
) {
1883 rdev
= conf
->disks
[i
].rdev
;
1886 if (bi
== &sh
->dev
[i
].rreq
) {
1887 rdev
= conf
->disks
[i
].replacement
;
1891 /* rdev was removed and 'replacement'
1892 * replaced it. rdev is not removed
1893 * until all requests are finished.
1895 rdev
= conf
->disks
[i
].rdev
;
1899 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1900 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1909 md_error(conf
->mddev
, rdev
);
1910 else if (is_badblock(rdev
, sh
->sector
,
1912 &first_bad
, &bad_sectors
))
1913 set_bit(R5_MadeGoodRepl
, &sh
->dev
[i
].flags
);
1916 set_bit(WriteErrorSeen
, &rdev
->flags
);
1917 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1918 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1919 set_bit(MD_RECOVERY_NEEDED
,
1920 &rdev
->mddev
->recovery
);
1921 } else if (is_badblock(rdev
, sh
->sector
,
1923 &first_bad
, &bad_sectors
))
1924 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1926 rdev_dec_pending(rdev
, conf
->mddev
);
1928 if (!test_and_clear_bit(R5_DOUBLE_LOCKED
, &sh
->dev
[i
].flags
))
1929 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1930 set_bit(STRIPE_HANDLE
, &sh
->state
);
1934 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1936 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1938 struct r5dev
*dev
= &sh
->dev
[i
];
1940 bio_init(&dev
->req
);
1941 dev
->req
.bi_io_vec
= &dev
->vec
;
1943 dev
->req
.bi_max_vecs
++;
1944 dev
->req
.bi_private
= sh
;
1945 dev
->vec
.bv_page
= dev
->page
;
1947 bio_init(&dev
->rreq
);
1948 dev
->rreq
.bi_io_vec
= &dev
->rvec
;
1949 dev
->rreq
.bi_vcnt
++;
1950 dev
->rreq
.bi_max_vecs
++;
1951 dev
->rreq
.bi_private
= sh
;
1952 dev
->rvec
.bv_page
= dev
->page
;
1955 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1958 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1960 char b
[BDEVNAME_SIZE
];
1961 struct r5conf
*conf
= mddev
->private;
1962 unsigned long flags
;
1963 pr_debug("raid456: error called\n");
1965 spin_lock_irqsave(&conf
->device_lock
, flags
);
1966 clear_bit(In_sync
, &rdev
->flags
);
1967 mddev
->degraded
= calc_degraded(conf
);
1968 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1969 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1971 set_bit(Blocked
, &rdev
->flags
);
1972 set_bit(Faulty
, &rdev
->flags
);
1973 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1975 "md/raid:%s: Disk failure on %s, disabling device.\n"
1976 "md/raid:%s: Operation continuing on %d devices.\n",
1978 bdevname(rdev
->bdev
, b
),
1980 conf
->raid_disks
- mddev
->degraded
);
1984 * Input: a 'big' sector number,
1985 * Output: index of the data and parity disk, and the sector # in them.
1987 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1988 int previous
, int *dd_idx
,
1989 struct stripe_head
*sh
)
1991 sector_t stripe
, stripe2
;
1992 sector_t chunk_number
;
1993 unsigned int chunk_offset
;
1996 sector_t new_sector
;
1997 int algorithm
= previous
? conf
->prev_algo
1999 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2000 : conf
->chunk_sectors
;
2001 int raid_disks
= previous
? conf
->previous_raid_disks
2003 int data_disks
= raid_disks
- conf
->max_degraded
;
2005 /* First compute the information on this sector */
2008 * Compute the chunk number and the sector offset inside the chunk
2010 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
2011 chunk_number
= r_sector
;
2014 * Compute the stripe number
2016 stripe
= chunk_number
;
2017 *dd_idx
= sector_div(stripe
, data_disks
);
2020 * Select the parity disk based on the user selected algorithm.
2022 pd_idx
= qd_idx
= -1;
2023 switch(conf
->level
) {
2025 pd_idx
= data_disks
;
2028 switch (algorithm
) {
2029 case ALGORITHM_LEFT_ASYMMETRIC
:
2030 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2031 if (*dd_idx
>= pd_idx
)
2034 case ALGORITHM_RIGHT_ASYMMETRIC
:
2035 pd_idx
= sector_div(stripe2
, raid_disks
);
2036 if (*dd_idx
>= pd_idx
)
2039 case ALGORITHM_LEFT_SYMMETRIC
:
2040 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
2041 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2043 case ALGORITHM_RIGHT_SYMMETRIC
:
2044 pd_idx
= sector_div(stripe2
, raid_disks
);
2045 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2047 case ALGORITHM_PARITY_0
:
2051 case ALGORITHM_PARITY_N
:
2052 pd_idx
= data_disks
;
2060 switch (algorithm
) {
2061 case ALGORITHM_LEFT_ASYMMETRIC
:
2062 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2063 qd_idx
= pd_idx
+ 1;
2064 if (pd_idx
== raid_disks
-1) {
2065 (*dd_idx
)++; /* Q D D D P */
2067 } else if (*dd_idx
>= pd_idx
)
2068 (*dd_idx
) += 2; /* D D P Q D */
2070 case ALGORITHM_RIGHT_ASYMMETRIC
:
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 */
2079 case ALGORITHM_LEFT_SYMMETRIC
:
2080 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2081 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2082 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2084 case ALGORITHM_RIGHT_SYMMETRIC
:
2085 pd_idx
= sector_div(stripe2
, raid_disks
);
2086 qd_idx
= (pd_idx
+ 1) % raid_disks
;
2087 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
2090 case ALGORITHM_PARITY_0
:
2095 case ALGORITHM_PARITY_N
:
2096 pd_idx
= data_disks
;
2097 qd_idx
= data_disks
+ 1;
2100 case ALGORITHM_ROTATING_ZERO_RESTART
:
2101 /* Exactly the same as RIGHT_ASYMMETRIC, but or
2102 * of blocks for computing Q is different.
2104 pd_idx
= sector_div(stripe2
, raid_disks
);
2105 qd_idx
= pd_idx
+ 1;
2106 if (pd_idx
== raid_disks
-1) {
2107 (*dd_idx
)++; /* Q D D D P */
2109 } else if (*dd_idx
>= pd_idx
)
2110 (*dd_idx
) += 2; /* D D P Q D */
2114 case ALGORITHM_ROTATING_N_RESTART
:
2115 /* Same a left_asymmetric, by first stripe is
2116 * D D D P Q rather than
2120 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2121 qd_idx
= pd_idx
+ 1;
2122 if (pd_idx
== raid_disks
-1) {
2123 (*dd_idx
)++; /* Q D D D P */
2125 } else if (*dd_idx
>= pd_idx
)
2126 (*dd_idx
) += 2; /* D D P Q D */
2130 case ALGORITHM_ROTATING_N_CONTINUE
:
2131 /* Same as left_symmetric but Q is before P */
2132 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
2133 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
2134 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
2138 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2139 /* RAID5 left_asymmetric, with Q on last device */
2140 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2141 if (*dd_idx
>= pd_idx
)
2143 qd_idx
= raid_disks
- 1;
2146 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2147 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2148 if (*dd_idx
>= pd_idx
)
2150 qd_idx
= raid_disks
- 1;
2153 case ALGORITHM_LEFT_SYMMETRIC_6
:
2154 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
2155 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2156 qd_idx
= raid_disks
- 1;
2159 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2160 pd_idx
= sector_div(stripe2
, raid_disks
-1);
2161 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
2162 qd_idx
= raid_disks
- 1;
2165 case ALGORITHM_PARITY_0_6
:
2168 qd_idx
= raid_disks
- 1;
2178 sh
->pd_idx
= pd_idx
;
2179 sh
->qd_idx
= qd_idx
;
2180 sh
->ddf_layout
= ddf_layout
;
2183 * Finally, compute the new sector number
2185 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
2190 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
2192 struct r5conf
*conf
= sh
->raid_conf
;
2193 int raid_disks
= sh
->disks
;
2194 int data_disks
= raid_disks
- conf
->max_degraded
;
2195 sector_t new_sector
= sh
->sector
, check
;
2196 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
2197 : conf
->chunk_sectors
;
2198 int algorithm
= previous
? conf
->prev_algo
2202 sector_t chunk_number
;
2203 int dummy1
, dd_idx
= i
;
2205 struct stripe_head sh2
;
2208 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
2209 stripe
= new_sector
;
2211 if (i
== sh
->pd_idx
)
2213 switch(conf
->level
) {
2216 switch (algorithm
) {
2217 case ALGORITHM_LEFT_ASYMMETRIC
:
2218 case ALGORITHM_RIGHT_ASYMMETRIC
:
2222 case ALGORITHM_LEFT_SYMMETRIC
:
2223 case ALGORITHM_RIGHT_SYMMETRIC
:
2226 i
-= (sh
->pd_idx
+ 1);
2228 case ALGORITHM_PARITY_0
:
2231 case ALGORITHM_PARITY_N
:
2238 if (i
== sh
->qd_idx
)
2239 return 0; /* It is the Q disk */
2240 switch (algorithm
) {
2241 case ALGORITHM_LEFT_ASYMMETRIC
:
2242 case ALGORITHM_RIGHT_ASYMMETRIC
:
2243 case ALGORITHM_ROTATING_ZERO_RESTART
:
2244 case ALGORITHM_ROTATING_N_RESTART
:
2245 if (sh
->pd_idx
== raid_disks
-1)
2246 i
--; /* Q D D D P */
2247 else if (i
> sh
->pd_idx
)
2248 i
-= 2; /* D D P Q D */
2250 case ALGORITHM_LEFT_SYMMETRIC
:
2251 case ALGORITHM_RIGHT_SYMMETRIC
:
2252 if (sh
->pd_idx
== raid_disks
-1)
2253 i
--; /* Q D D D P */
2258 i
-= (sh
->pd_idx
+ 2);
2261 case ALGORITHM_PARITY_0
:
2264 case ALGORITHM_PARITY_N
:
2266 case ALGORITHM_ROTATING_N_CONTINUE
:
2267 /* Like left_symmetric, but P is before Q */
2268 if (sh
->pd_idx
== 0)
2269 i
--; /* P D D D Q */
2274 i
-= (sh
->pd_idx
+ 1);
2277 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2278 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2282 case ALGORITHM_LEFT_SYMMETRIC_6
:
2283 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2285 i
+= data_disks
+ 1;
2286 i
-= (sh
->pd_idx
+ 1);
2288 case ALGORITHM_PARITY_0_6
:
2297 chunk_number
= stripe
* data_disks
+ i
;
2298 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2300 check
= raid5_compute_sector(conf
, r_sector
,
2301 previous
, &dummy1
, &sh2
);
2302 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2303 || sh2
.qd_idx
!= sh
->qd_idx
) {
2304 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2305 mdname(conf
->mddev
));
2313 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2314 int rcw
, int expand
)
2316 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2317 struct r5conf
*conf
= sh
->raid_conf
;
2318 int level
= conf
->level
;
2321 /* if we are not expanding this is a proper write request, and
2322 * there will be bios with new data to be drained into the
2326 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2327 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2329 sh
->reconstruct_state
= reconstruct_state_run
;
2331 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2333 for (i
= disks
; i
--; ) {
2334 struct r5dev
*dev
= &sh
->dev
[i
];
2337 set_bit(R5_LOCKED
, &dev
->flags
);
2338 set_bit(R5_Wantdrain
, &dev
->flags
);
2340 clear_bit(R5_UPTODATE
, &dev
->flags
);
2344 if (s
->locked
+ conf
->max_degraded
== disks
)
2345 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2346 atomic_inc(&conf
->pending_full_writes
);
2349 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2350 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2352 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2353 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2354 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2355 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2357 for (i
= disks
; i
--; ) {
2358 struct r5dev
*dev
= &sh
->dev
[i
];
2363 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2364 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2365 set_bit(R5_Wantdrain
, &dev
->flags
);
2366 set_bit(R5_LOCKED
, &dev
->flags
);
2367 clear_bit(R5_UPTODATE
, &dev
->flags
);
2373 /* keep the parity disk(s) locked while asynchronous operations
2376 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2377 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2381 int qd_idx
= sh
->qd_idx
;
2382 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2384 set_bit(R5_LOCKED
, &dev
->flags
);
2385 clear_bit(R5_UPTODATE
, &dev
->flags
);
2389 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2390 __func__
, (unsigned long long)sh
->sector
,
2391 s
->locked
, s
->ops_request
);
2395 * Each stripe/dev can have one or more bion attached.
2396 * toread/towrite point to the first in a chain.
2397 * The bi_next chain must be in order.
2399 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2402 struct r5conf
*conf
= sh
->raid_conf
;
2405 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2406 (unsigned long long)bi
->bi_sector
,
2407 (unsigned long long)sh
->sector
);
2410 * If several bio share a stripe. The bio bi_phys_segments acts as a
2411 * reference count to avoid race. The reference count should already be
2412 * increased before this function is called (for example, in
2413 * make_request()), so other bio sharing this stripe will not free the
2414 * stripe. If a stripe is owned by one stripe, the stripe lock will
2417 spin_lock_irq(&sh
->stripe_lock
);
2419 bip
= &sh
->dev
[dd_idx
].towrite
;
2423 bip
= &sh
->dev
[dd_idx
].toread
;
2424 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2425 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2427 bip
= & (*bip
)->bi_next
;
2429 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2432 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2436 raid5_inc_bi_active_stripes(bi
);
2439 /* check if page is covered */
2440 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2441 for (bi
=sh
->dev
[dd_idx
].towrite
;
2442 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2443 bi
&& bi
->bi_sector
<= sector
;
2444 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2445 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2446 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2448 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2449 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2452 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2453 (unsigned long long)(*bip
)->bi_sector
,
2454 (unsigned long long)sh
->sector
, dd_idx
);
2455 spin_unlock_irq(&sh
->stripe_lock
);
2457 if (conf
->mddev
->bitmap
&& firstwrite
) {
2458 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2460 sh
->bm_seq
= conf
->seq_flush
+1;
2461 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2466 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2467 spin_unlock_irq(&sh
->stripe_lock
);
2471 static void end_reshape(struct r5conf
*conf
);
2473 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2474 struct stripe_head
*sh
)
2476 int sectors_per_chunk
=
2477 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2479 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2480 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2482 raid5_compute_sector(conf
,
2483 stripe
* (disks
- conf
->max_degraded
)
2484 *sectors_per_chunk
+ chunk_offset
,
2490 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2491 struct stripe_head_state
*s
, int disks
,
2492 struct bio
**return_bi
)
2495 for (i
= disks
; i
--; ) {
2499 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2500 struct md_rdev
*rdev
;
2502 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2503 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2504 atomic_inc(&rdev
->nr_pending
);
2509 if (!rdev_set_badblocks(
2513 md_error(conf
->mddev
, rdev
);
2514 rdev_dec_pending(rdev
, conf
->mddev
);
2517 spin_lock_irq(&sh
->stripe_lock
);
2518 /* fail all writes first */
2519 bi
= sh
->dev
[i
].towrite
;
2520 sh
->dev
[i
].towrite
= NULL
;
2521 spin_unlock_irq(&sh
->stripe_lock
);
2525 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2526 wake_up(&conf
->wait_for_overlap
);
2528 while (bi
&& bi
->bi_sector
<
2529 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2530 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2531 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2532 if (!raid5_dec_bi_active_stripes(bi
)) {
2533 md_write_end(conf
->mddev
);
2534 bi
->bi_next
= *return_bi
;
2540 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2541 STRIPE_SECTORS
, 0, 0);
2543 /* and fail all 'written' */
2544 bi
= sh
->dev
[i
].written
;
2545 sh
->dev
[i
].written
= NULL
;
2546 if (bi
) bitmap_end
= 1;
2547 while (bi
&& bi
->bi_sector
<
2548 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2549 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2550 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2551 if (!raid5_dec_bi_active_stripes(bi
)) {
2552 md_write_end(conf
->mddev
);
2553 bi
->bi_next
= *return_bi
;
2559 /* fail any reads if this device is non-operational and
2560 * the data has not reached the cache yet.
2562 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2563 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2564 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2565 spin_lock_irq(&sh
->stripe_lock
);
2566 bi
= sh
->dev
[i
].toread
;
2567 sh
->dev
[i
].toread
= NULL
;
2568 spin_unlock_irq(&sh
->stripe_lock
);
2569 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2570 wake_up(&conf
->wait_for_overlap
);
2571 while (bi
&& bi
->bi_sector
<
2572 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2573 struct bio
*nextbi
=
2574 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2575 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2576 if (!raid5_dec_bi_active_stripes(bi
)) {
2577 bi
->bi_next
= *return_bi
;
2584 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2585 STRIPE_SECTORS
, 0, 0);
2586 /* If we were in the middle of a write the parity block might
2587 * still be locked - so just clear all R5_LOCKED flags
2589 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2592 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2593 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2594 md_wakeup_thread(conf
->mddev
->thread
);
2598 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2599 struct stripe_head_state
*s
)
2604 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2607 /* There is nothing more to do for sync/check/repair.
2608 * Don't even need to abort as that is handled elsewhere
2609 * if needed, and not always wanted e.g. if there is a known
2611 * For recover/replace we need to record a bad block on all
2612 * non-sync devices, or abort the recovery
2614 if (test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
)) {
2615 /* During recovery devices cannot be removed, so
2616 * locking and refcounting of rdevs is not needed
2618 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2619 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2621 && !test_bit(Faulty
, &rdev
->flags
)
2622 && !test_bit(In_sync
, &rdev
->flags
)
2623 && !rdev_set_badblocks(rdev
, sh
->sector
,
2626 rdev
= conf
->disks
[i
].replacement
;
2628 && !test_bit(Faulty
, &rdev
->flags
)
2629 && !test_bit(In_sync
, &rdev
->flags
)
2630 && !rdev_set_badblocks(rdev
, sh
->sector
,
2635 conf
->recovery_disabled
=
2636 conf
->mddev
->recovery_disabled
;
2638 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, !abort
);
2641 static int want_replace(struct stripe_head
*sh
, int disk_idx
)
2643 struct md_rdev
*rdev
;
2645 /* Doing recovery so rcu locking not required */
2646 rdev
= sh
->raid_conf
->disks
[disk_idx
].replacement
;
2648 && !test_bit(Faulty
, &rdev
->flags
)
2649 && !test_bit(In_sync
, &rdev
->flags
)
2650 && (rdev
->recovery_offset
<= sh
->sector
2651 || rdev
->mddev
->recovery_cp
<= sh
->sector
))
2657 /* fetch_block - checks the given member device to see if its data needs
2658 * to be read or computed to satisfy a request.
2660 * Returns 1 when no more member devices need to be checked, otherwise returns
2661 * 0 to tell the loop in handle_stripe_fill to continue
2663 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2664 int disk_idx
, int disks
)
2666 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2667 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2668 &sh
->dev
[s
->failed_num
[1]] };
2670 /* is the data in this block needed, and can we get it? */
2671 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2672 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2674 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2675 s
->syncing
|| s
->expanding
||
2676 (s
->replacing
&& want_replace(sh
, disk_idx
)) ||
2677 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2678 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2679 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2680 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2681 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2682 /* we would like to get this block, possibly by computing it,
2683 * otherwise read it if the backing disk is insync
2685 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2686 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2687 if ((s
->uptodate
== disks
- 1) &&
2688 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2689 disk_idx
== s
->failed_num
[1]))) {
2690 /* have disk failed, and we're requested to fetch it;
2693 pr_debug("Computing stripe %llu block %d\n",
2694 (unsigned long long)sh
->sector
, disk_idx
);
2695 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2696 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2697 set_bit(R5_Wantcompute
, &dev
->flags
);
2698 sh
->ops
.target
= disk_idx
;
2699 sh
->ops
.target2
= -1; /* no 2nd target */
2701 /* Careful: from this point on 'uptodate' is in the eye
2702 * of raid_run_ops which services 'compute' operations
2703 * before writes. R5_Wantcompute flags a block that will
2704 * be R5_UPTODATE by the time it is needed for a
2705 * subsequent operation.
2709 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2710 /* Computing 2-failure is *very* expensive; only
2711 * do it if failed >= 2
2714 for (other
= disks
; other
--; ) {
2715 if (other
== disk_idx
)
2717 if (!test_bit(R5_UPTODATE
,
2718 &sh
->dev
[other
].flags
))
2722 pr_debug("Computing stripe %llu blocks %d,%d\n",
2723 (unsigned long long)sh
->sector
,
2725 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2726 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2727 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2728 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2729 sh
->ops
.target
= disk_idx
;
2730 sh
->ops
.target2
= other
;
2734 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2735 set_bit(R5_LOCKED
, &dev
->flags
);
2736 set_bit(R5_Wantread
, &dev
->flags
);
2738 pr_debug("Reading block %d (sync=%d)\n",
2739 disk_idx
, s
->syncing
);
2747 * handle_stripe_fill - read or compute data to satisfy pending requests.
2749 static void handle_stripe_fill(struct stripe_head
*sh
,
2750 struct stripe_head_state
*s
,
2755 /* look for blocks to read/compute, skip this if a compute
2756 * is already in flight, or if the stripe contents are in the
2757 * midst of changing due to a write
2759 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2760 !sh
->reconstruct_state
)
2761 for (i
= disks
; i
--; )
2762 if (fetch_block(sh
, s
, i
, disks
))
2764 set_bit(STRIPE_HANDLE
, &sh
->state
);
2768 /* handle_stripe_clean_event
2769 * any written block on an uptodate or failed drive can be returned.
2770 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2771 * never LOCKED, so we don't need to test 'failed' directly.
2773 static void handle_stripe_clean_event(struct r5conf
*conf
,
2774 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2779 for (i
= disks
; i
--; )
2780 if (sh
->dev
[i
].written
) {
2782 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2783 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2784 test_bit(R5_Discard
, &dev
->flags
))) {
2785 /* We can return any write requests */
2786 struct bio
*wbi
, *wbi2
;
2787 pr_debug("Return write for disc %d\n", i
);
2788 if (test_and_clear_bit(R5_Discard
, &dev
->flags
))
2789 clear_bit(R5_UPTODATE
, &dev
->flags
);
2791 dev
->written
= NULL
;
2792 while (wbi
&& wbi
->bi_sector
<
2793 dev
->sector
+ STRIPE_SECTORS
) {
2794 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2795 if (!raid5_dec_bi_active_stripes(wbi
)) {
2796 md_write_end(conf
->mddev
);
2797 wbi
->bi_next
= *return_bi
;
2802 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2804 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2807 } else if (test_bit(R5_Discard
, &sh
->dev
[i
].flags
))
2808 clear_bit(R5_Discard
, &sh
->dev
[i
].flags
);
2810 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2811 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2812 md_wakeup_thread(conf
->mddev
->thread
);
2815 static void handle_stripe_dirtying(struct r5conf
*conf
,
2816 struct stripe_head
*sh
,
2817 struct stripe_head_state
*s
,
2820 int rmw
= 0, rcw
= 0, i
;
2821 sector_t recovery_cp
= conf
->mddev
->recovery_cp
;
2823 /* RAID6 requires 'rcw' in current implementation.
2824 * Otherwise, check whether resync is now happening or should start.
2825 * If yes, then the array is dirty (after unclean shutdown or
2826 * initial creation), so parity in some stripes might be inconsistent.
2827 * In this case, we need to always do reconstruct-write, to ensure
2828 * that in case of drive failure or read-error correction, we
2829 * generate correct data from the parity.
2831 if (conf
->max_degraded
== 2 ||
2832 (recovery_cp
< MaxSector
&& sh
->sector
>= recovery_cp
)) {
2833 /* Calculate the real rcw later - for now make it
2834 * look like rcw is cheaper
2837 pr_debug("force RCW max_degraded=%u, recovery_cp=%llu sh->sector=%llu\n",
2838 conf
->max_degraded
, (unsigned long long)recovery_cp
,
2839 (unsigned long long)sh
->sector
);
2840 } else for (i
= disks
; i
--; ) {
2841 /* would I have to read this buffer for read_modify_write */
2842 struct r5dev
*dev
= &sh
->dev
[i
];
2843 if ((dev
->towrite
|| 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
))
2850 rmw
+= 2*disks
; /* cannot read it */
2852 /* Would I have to read this buffer for reconstruct_write */
2853 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2854 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2855 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2856 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2857 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2862 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2863 (unsigned long long)sh
->sector
, rmw
, rcw
);
2864 set_bit(STRIPE_HANDLE
, &sh
->state
);
2865 if (rmw
< rcw
&& rmw
> 0) {
2866 /* prefer read-modify-write, but need to get some data */
2867 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rmw %llu %d",
2868 (unsigned long long)sh
->sector
, rmw
);
2869 for (i
= disks
; i
--; ) {
2870 struct r5dev
*dev
= &sh
->dev
[i
];
2871 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2872 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2873 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2874 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2875 test_bit(R5_Insync
, &dev
->flags
)) {
2877 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2878 pr_debug("Read_old block "
2879 "%d for r-m-w\n", i
);
2880 set_bit(R5_LOCKED
, &dev
->flags
);
2881 set_bit(R5_Wantread
, &dev
->flags
);
2884 set_bit(STRIPE_DELAYED
, &sh
->state
);
2885 set_bit(STRIPE_HANDLE
, &sh
->state
);
2890 if (rcw
<= rmw
&& rcw
> 0) {
2891 /* want reconstruct write, but need to get some data */
2894 for (i
= disks
; i
--; ) {
2895 struct r5dev
*dev
= &sh
->dev
[i
];
2896 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2897 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2898 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2899 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2900 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2902 if (!test_bit(R5_Insync
, &dev
->flags
))
2903 continue; /* it's a failed drive */
2905 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2906 pr_debug("Read_old block "
2907 "%d for Reconstruct\n", i
);
2908 set_bit(R5_LOCKED
, &dev
->flags
);
2909 set_bit(R5_Wantread
, &dev
->flags
);
2913 set_bit(STRIPE_DELAYED
, &sh
->state
);
2914 set_bit(STRIPE_HANDLE
, &sh
->state
);
2919 blk_add_trace_msg(conf
->mddev
->queue
, "raid5 rcw %llu %d %d %d",
2920 (unsigned long long)sh
->sector
,
2921 rcw
, qread
, test_bit(STRIPE_DELAYED
, &sh
->state
));
2923 /* now if nothing is locked, and if we have enough data,
2924 * we can start a write request
2926 /* since handle_stripe can be called at any time we need to handle the
2927 * case where a compute block operation has been submitted and then a
2928 * subsequent call wants to start a write request. raid_run_ops only
2929 * handles the case where compute block and reconstruct are requested
2930 * simultaneously. If this is not the case then new writes need to be
2931 * held off until the compute completes.
2933 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2934 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2935 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2936 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2939 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2940 struct stripe_head_state
*s
, int disks
)
2942 struct r5dev
*dev
= NULL
;
2944 set_bit(STRIPE_HANDLE
, &sh
->state
);
2946 switch (sh
->check_state
) {
2947 case check_state_idle
:
2948 /* start a new check operation if there are no failures */
2949 if (s
->failed
== 0) {
2950 BUG_ON(s
->uptodate
!= disks
);
2951 sh
->check_state
= check_state_run
;
2952 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2953 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2957 dev
= &sh
->dev
[s
->failed_num
[0]];
2959 case check_state_compute_result
:
2960 sh
->check_state
= check_state_idle
;
2962 dev
= &sh
->dev
[sh
->pd_idx
];
2964 /* check that a write has not made the stripe insync */
2965 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2968 /* either failed parity check, or recovery is happening */
2969 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2970 BUG_ON(s
->uptodate
!= disks
);
2972 set_bit(R5_LOCKED
, &dev
->flags
);
2974 set_bit(R5_Wantwrite
, &dev
->flags
);
2976 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2977 set_bit(STRIPE_INSYNC
, &sh
->state
);
2979 case check_state_run
:
2980 break; /* we will be called again upon completion */
2981 case check_state_check_result
:
2982 sh
->check_state
= check_state_idle
;
2984 /* if a failure occurred during the check operation, leave
2985 * STRIPE_INSYNC not set and let the stripe be handled again
2990 /* handle a successful check operation, if parity is correct
2991 * we are done. Otherwise update the mismatch count and repair
2992 * parity if !MD_RECOVERY_CHECK
2994 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2995 /* parity is correct (on disc,
2996 * not in buffer any more)
2998 set_bit(STRIPE_INSYNC
, &sh
->state
);
3000 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3001 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3002 /* don't try to repair!! */
3003 set_bit(STRIPE_INSYNC
, &sh
->state
);
3005 sh
->check_state
= check_state_compute_run
;
3006 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3007 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3008 set_bit(R5_Wantcompute
,
3009 &sh
->dev
[sh
->pd_idx
].flags
);
3010 sh
->ops
.target
= sh
->pd_idx
;
3011 sh
->ops
.target2
= -1;
3016 case check_state_compute_run
:
3019 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3020 __func__
, sh
->check_state
,
3021 (unsigned long long) sh
->sector
);
3027 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
3028 struct stripe_head_state
*s
,
3031 int pd_idx
= sh
->pd_idx
;
3032 int qd_idx
= sh
->qd_idx
;
3035 set_bit(STRIPE_HANDLE
, &sh
->state
);
3037 BUG_ON(s
->failed
> 2);
3039 /* Want to check and possibly repair P and Q.
3040 * However there could be one 'failed' device, in which
3041 * case we can only check one of them, possibly using the
3042 * other to generate missing data
3045 switch (sh
->check_state
) {
3046 case check_state_idle
:
3047 /* start a new check operation if there are < 2 failures */
3048 if (s
->failed
== s
->q_failed
) {
3049 /* The only possible failed device holds Q, so it
3050 * makes sense to check P (If anything else were failed,
3051 * we would have used P to recreate it).
3053 sh
->check_state
= check_state_run
;
3055 if (!s
->q_failed
&& s
->failed
< 2) {
3056 /* Q is not failed, and we didn't use it to generate
3057 * anything, so it makes sense to check it
3059 if (sh
->check_state
== check_state_run
)
3060 sh
->check_state
= check_state_run_pq
;
3062 sh
->check_state
= check_state_run_q
;
3065 /* discard potentially stale zero_sum_result */
3066 sh
->ops
.zero_sum_result
= 0;
3068 if (sh
->check_state
== check_state_run
) {
3069 /* async_xor_zero_sum destroys the contents of P */
3070 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
3073 if (sh
->check_state
>= check_state_run
&&
3074 sh
->check_state
<= check_state_run_pq
) {
3075 /* async_syndrome_zero_sum preserves P and Q, so
3076 * no need to mark them !uptodate here
3078 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
3082 /* we have 2-disk failure */
3083 BUG_ON(s
->failed
!= 2);
3085 case check_state_compute_result
:
3086 sh
->check_state
= check_state_idle
;
3088 /* check that a write has not made the stripe insync */
3089 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
3092 /* now write out any block on a failed drive,
3093 * or P or Q if they were recomputed
3095 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
3096 if (s
->failed
== 2) {
3097 dev
= &sh
->dev
[s
->failed_num
[1]];
3099 set_bit(R5_LOCKED
, &dev
->flags
);
3100 set_bit(R5_Wantwrite
, &dev
->flags
);
3102 if (s
->failed
>= 1) {
3103 dev
= &sh
->dev
[s
->failed_num
[0]];
3105 set_bit(R5_LOCKED
, &dev
->flags
);
3106 set_bit(R5_Wantwrite
, &dev
->flags
);
3108 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3109 dev
= &sh
->dev
[pd_idx
];
3111 set_bit(R5_LOCKED
, &dev
->flags
);
3112 set_bit(R5_Wantwrite
, &dev
->flags
);
3114 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3115 dev
= &sh
->dev
[qd_idx
];
3117 set_bit(R5_LOCKED
, &dev
->flags
);
3118 set_bit(R5_Wantwrite
, &dev
->flags
);
3120 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
3122 set_bit(STRIPE_INSYNC
, &sh
->state
);
3124 case check_state_run
:
3125 case check_state_run_q
:
3126 case check_state_run_pq
:
3127 break; /* we will be called again upon completion */
3128 case check_state_check_result
:
3129 sh
->check_state
= check_state_idle
;
3131 /* handle a successful check operation, if parity is correct
3132 * we are done. Otherwise update the mismatch count and repair
3133 * parity if !MD_RECOVERY_CHECK
3135 if (sh
->ops
.zero_sum_result
== 0) {
3136 /* both parities are correct */
3138 set_bit(STRIPE_INSYNC
, &sh
->state
);
3140 /* in contrast to the raid5 case we can validate
3141 * parity, but still have a failure to write
3144 sh
->check_state
= check_state_compute_result
;
3145 /* Returning at this point means that we may go
3146 * off and bring p and/or q uptodate again so
3147 * we make sure to check zero_sum_result again
3148 * to verify if p or q need writeback
3152 atomic64_add(STRIPE_SECTORS
, &conf
->mddev
->resync_mismatches
);
3153 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
3154 /* don't try to repair!! */
3155 set_bit(STRIPE_INSYNC
, &sh
->state
);
3157 int *target
= &sh
->ops
.target
;
3159 sh
->ops
.target
= -1;
3160 sh
->ops
.target2
= -1;
3161 sh
->check_state
= check_state_compute_run
;
3162 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
3163 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
3164 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
3165 set_bit(R5_Wantcompute
,
3166 &sh
->dev
[pd_idx
].flags
);
3168 target
= &sh
->ops
.target2
;
3171 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
3172 set_bit(R5_Wantcompute
,
3173 &sh
->dev
[qd_idx
].flags
);
3180 case check_state_compute_run
:
3183 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
3184 __func__
, sh
->check_state
,
3185 (unsigned long long) sh
->sector
);
3190 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
3194 /* We have read all the blocks in this stripe and now we need to
3195 * copy some of them into a target stripe for expand.
3197 struct dma_async_tx_descriptor
*tx
= NULL
;
3198 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3199 for (i
= 0; i
< sh
->disks
; i
++)
3200 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
3202 struct stripe_head
*sh2
;
3203 struct async_submit_ctl submit
;
3205 sector_t bn
= compute_blocknr(sh
, i
, 1);
3206 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
3208 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
3210 /* so far only the early blocks of this stripe
3211 * have been requested. When later blocks
3212 * get requested, we will try again
3215 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
3216 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
3217 /* must have already done this block */
3218 release_stripe(sh2
);
3222 /* place all the copies on one channel */
3223 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
3224 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
3225 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
3228 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
3229 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
3230 for (j
= 0; j
< conf
->raid_disks
; j
++)
3231 if (j
!= sh2
->pd_idx
&&
3233 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
3235 if (j
== conf
->raid_disks
) {
3236 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
3237 set_bit(STRIPE_HANDLE
, &sh2
->state
);
3239 release_stripe(sh2
);
3242 /* done submitting copies, wait for them to complete */
3243 async_tx_quiesce(&tx
);
3247 * handle_stripe - do things to a stripe.
3249 * We lock the stripe by setting STRIPE_ACTIVE and then examine the
3250 * state of various bits to see what needs to be done.
3252 * return some read requests which now have data
3253 * return some write requests which are safely on storage
3254 * schedule a read on some buffers
3255 * schedule a write of some buffers
3256 * return confirmation of parity correctness
3260 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3262 struct r5conf
*conf
= sh
->raid_conf
;
3263 int disks
= sh
->disks
;
3266 int do_recovery
= 0;
3268 memset(s
, 0, sizeof(*s
));
3270 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3271 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3272 s
->failed_num
[0] = -1;
3273 s
->failed_num
[1] = -1;
3275 /* Now to look around and see what can be done */
3277 for (i
=disks
; i
--; ) {
3278 struct md_rdev
*rdev
;
3285 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3287 dev
->toread
, dev
->towrite
, dev
->written
);
3288 /* maybe we can reply to a read
3290 * new wantfill requests are only permitted while
3291 * ops_complete_biofill is guaranteed to be inactive
3293 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3294 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3295 set_bit(R5_Wantfill
, &dev
->flags
);
3297 /* now count some things */
3298 if (test_bit(R5_LOCKED
, &dev
->flags
))
3300 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3302 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3304 BUG_ON(s
->compute
> 2);
3307 if (test_bit(R5_Wantfill
, &dev
->flags
))
3309 else if (dev
->toread
)
3313 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3318 /* Prefer to use the replacement for reads, but only
3319 * if it is recovered enough and has no bad blocks.
3321 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3322 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3323 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3324 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3325 &first_bad
, &bad_sectors
))
3326 set_bit(R5_ReadRepl
, &dev
->flags
);
3329 set_bit(R5_NeedReplace
, &dev
->flags
);
3330 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3331 clear_bit(R5_ReadRepl
, &dev
->flags
);
3333 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3336 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3337 &first_bad
, &bad_sectors
);
3338 if (s
->blocked_rdev
== NULL
3339 && (test_bit(Blocked
, &rdev
->flags
)
3342 set_bit(BlockedBadBlocks
,
3344 s
->blocked_rdev
= rdev
;
3345 atomic_inc(&rdev
->nr_pending
);
3348 clear_bit(R5_Insync
, &dev
->flags
);
3352 /* also not in-sync */
3353 if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
3354 test_bit(R5_UPTODATE
, &dev
->flags
)) {
3355 /* treat as in-sync, but with a read error
3356 * which we can now try to correct
3358 set_bit(R5_Insync
, &dev
->flags
);
3359 set_bit(R5_ReadError
, &dev
->flags
);
3361 } else if (test_bit(In_sync
, &rdev
->flags
))
3362 set_bit(R5_Insync
, &dev
->flags
);
3363 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3364 /* in sync if before recovery_offset */
3365 set_bit(R5_Insync
, &dev
->flags
);
3366 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3367 test_bit(R5_Expanded
, &dev
->flags
))
3368 /* If we've reshaped into here, we assume it is Insync.
3369 * We will shortly update recovery_offset to make
3372 set_bit(R5_Insync
, &dev
->flags
);
3374 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3375 /* This flag does not apply to '.replacement'
3376 * only to .rdev, so make sure to check that*/
3377 struct md_rdev
*rdev2
= rcu_dereference(
3378 conf
->disks
[i
].rdev
);
3380 clear_bit(R5_Insync
, &dev
->flags
);
3381 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3382 s
->handle_bad_blocks
= 1;
3383 atomic_inc(&rdev2
->nr_pending
);
3385 clear_bit(R5_WriteError
, &dev
->flags
);
3387 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3388 /* This flag does not apply to '.replacement'
3389 * only to .rdev, so make sure to check that*/
3390 struct md_rdev
*rdev2
= rcu_dereference(
3391 conf
->disks
[i
].rdev
);
3392 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3393 s
->handle_bad_blocks
= 1;
3394 atomic_inc(&rdev2
->nr_pending
);
3396 clear_bit(R5_MadeGood
, &dev
->flags
);
3398 if (test_bit(R5_MadeGoodRepl
, &dev
->flags
)) {
3399 struct md_rdev
*rdev2
= rcu_dereference(
3400 conf
->disks
[i
].replacement
);
3401 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3402 s
->handle_bad_blocks
= 1;
3403 atomic_inc(&rdev2
->nr_pending
);
3405 clear_bit(R5_MadeGoodRepl
, &dev
->flags
);
3407 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3408 /* The ReadError flag will just be confusing now */
3409 clear_bit(R5_ReadError
, &dev
->flags
);
3410 clear_bit(R5_ReWrite
, &dev
->flags
);
3412 if (test_bit(R5_ReadError
, &dev
->flags
))
3413 clear_bit(R5_Insync
, &dev
->flags
);
3414 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3416 s
->failed_num
[s
->failed
] = i
;
3418 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
))
3422 if (test_bit(STRIPE_SYNCING
, &sh
->state
)) {
3423 /* If there is a failed device being replaced,
3424 * we must be recovering.
3425 * else if we are after recovery_cp, we must be syncing
3426 * else if MD_RECOVERY_REQUESTED is set, we also are syncing.
3427 * else we can only be replacing
3428 * sync and recovery both need to read all devices, and so
3429 * use the same flag.
3432 sh
->sector
>= conf
->mddev
->recovery_cp
||
3433 test_bit(MD_RECOVERY_REQUESTED
, &(conf
->mddev
->recovery
)))
3441 static void handle_stripe(struct stripe_head
*sh
)
3443 struct stripe_head_state s
;
3444 struct r5conf
*conf
= sh
->raid_conf
;
3447 int disks
= sh
->disks
;
3448 struct r5dev
*pdev
, *qdev
;
3450 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3451 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3452 /* already being handled, ensure it gets handled
3453 * again when current action finishes */
3454 set_bit(STRIPE_HANDLE
, &sh
->state
);
3458 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3459 set_bit(STRIPE_SYNCING
, &sh
->state
);
3460 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3462 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3464 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3465 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3466 (unsigned long long)sh
->sector
, sh
->state
,
3467 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3468 sh
->check_state
, sh
->reconstruct_state
);
3470 analyse_stripe(sh
, &s
);
3472 if (s
.handle_bad_blocks
) {
3473 set_bit(STRIPE_HANDLE
, &sh
->state
);
3477 if (unlikely(s
.blocked_rdev
)) {
3478 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3479 s
.replacing
|| s
.to_write
|| s
.written
) {
3480 set_bit(STRIPE_HANDLE
, &sh
->state
);
3483 /* There is nothing for the blocked_rdev to block */
3484 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3485 s
.blocked_rdev
= NULL
;
3488 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3489 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3490 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3493 pr_debug("locked=%d uptodate=%d to_read=%d"
3494 " to_write=%d failed=%d failed_num=%d,%d\n",
3495 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3496 s
.failed_num
[0], s
.failed_num
[1]);
3497 /* check if the array has lost more than max_degraded devices and,
3498 * if so, some requests might need to be failed.
3500 if (s
.failed
> conf
->max_degraded
) {
3501 sh
->check_state
= 0;
3502 sh
->reconstruct_state
= 0;
3503 if (s
.to_read
+s
.to_write
+s
.written
)
3504 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3505 if (s
.syncing
+ s
.replacing
)
3506 handle_failed_sync(conf
, sh
, &s
);
3509 /* Now we check to see if any write operations have recently
3513 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3515 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3516 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3517 sh
->reconstruct_state
= reconstruct_state_idle
;
3519 /* All the 'written' buffers and the parity block are ready to
3520 * be written back to disk
3522 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
) &&
3523 !test_bit(R5_Discard
, &sh
->dev
[sh
->pd_idx
].flags
));
3524 BUG_ON(sh
->qd_idx
>= 0 &&
3525 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
) &&
3526 !test_bit(R5_Discard
, &sh
->dev
[sh
->qd_idx
].flags
));
3527 for (i
= disks
; i
--; ) {
3528 struct r5dev
*dev
= &sh
->dev
[i
];
3529 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3530 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3532 pr_debug("Writing block %d\n", i
);
3533 set_bit(R5_Wantwrite
, &dev
->flags
);
3536 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3537 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3539 set_bit(STRIPE_INSYNC
, &sh
->state
);
3542 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3543 s
.dec_preread_active
= 1;
3547 * might be able to return some write requests if the parity blocks
3548 * are safe, or on a failed drive
3550 pdev
= &sh
->dev
[sh
->pd_idx
];
3551 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3552 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3553 qdev
= &sh
->dev
[sh
->qd_idx
];
3554 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3555 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3559 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3560 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3561 && (test_bit(R5_UPTODATE
, &pdev
->flags
) ||
3562 test_bit(R5_Discard
, &pdev
->flags
))))) &&
3563 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3564 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3565 && (test_bit(R5_UPTODATE
, &qdev
->flags
) ||
3566 test_bit(R5_Discard
, &qdev
->flags
))))))
3567 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3569 /* Now we might consider reading some blocks, either to check/generate
3570 * parity, or to satisfy requests
3571 * or to load a block that is being partially written.
3573 if (s
.to_read
|| s
.non_overwrite
3574 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3575 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
))
3578 handle_stripe_fill(sh
, &s
, disks
);
3580 /* Now to consider new write requests and what else, if anything
3581 * should be read. We do not handle new writes when:
3582 * 1/ A 'write' operation (copy+xor) is already in flight.
3583 * 2/ A 'check' operation is in flight, as it may clobber the parity
3586 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3587 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3589 /* maybe we need to check and possibly fix the parity for this stripe
3590 * Any reads will already have been scheduled, so we just see if enough
3591 * data is available. The parity check is held off while parity
3592 * dependent operations are in flight.
3594 if (sh
->check_state
||
3595 (s
.syncing
&& s
.locked
== 0 &&
3596 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3597 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3598 if (conf
->level
== 6)
3599 handle_parity_checks6(conf
, sh
, &s
, disks
);
3601 handle_parity_checks5(conf
, sh
, &s
, disks
);
3604 if (s
.replacing
&& s
.locked
== 0
3605 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3606 /* Write out to replacement devices where possible */
3607 for (i
= 0; i
< conf
->raid_disks
; i
++)
3608 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
) &&
3609 test_bit(R5_NeedReplace
, &sh
->dev
[i
].flags
)) {
3610 set_bit(R5_WantReplace
, &sh
->dev
[i
].flags
);
3611 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3614 set_bit(STRIPE_INSYNC
, &sh
->state
);
3616 if ((s
.syncing
|| s
.replacing
) && s
.locked
== 0 &&
3617 test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3618 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3619 clear_bit(STRIPE_SYNCING
, &sh
->state
);
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
);
4025 trace_block_bio_remap(bdev_get_queue(align_bi
->bi_bdev
),
4026 align_bi
, disk_devt(mddev
->gendisk
),
4027 raid_bio
->bi_sector
);
4028 generic_make_request(align_bi
);
4037 /* __get_priority_stripe - get the next stripe to process
4039 * Full stripe writes are allowed to pass preread active stripes up until
4040 * the bypass_threshold is exceeded. In general the bypass_count
4041 * increments when the handle_list is handled before the hold_list; however, it
4042 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
4043 * stripe with in flight i/o. The bypass_count will be reset when the
4044 * head of the hold_list has changed, i.e. the head was promoted to the
4047 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
4049 struct stripe_head
*sh
;
4051 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
4053 list_empty(&conf
->handle_list
) ? "empty" : "busy",
4054 list_empty(&conf
->hold_list
) ? "empty" : "busy",
4055 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
4057 if (!list_empty(&conf
->handle_list
)) {
4058 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
4060 if (list_empty(&conf
->hold_list
))
4061 conf
->bypass_count
= 0;
4062 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
4063 if (conf
->hold_list
.next
== conf
->last_hold
)
4064 conf
->bypass_count
++;
4066 conf
->last_hold
= conf
->hold_list
.next
;
4067 conf
->bypass_count
-= conf
->bypass_threshold
;
4068 if (conf
->bypass_count
< 0)
4069 conf
->bypass_count
= 0;
4072 } else if (!list_empty(&conf
->hold_list
) &&
4073 ((conf
->bypass_threshold
&&
4074 conf
->bypass_count
> conf
->bypass_threshold
) ||
4075 atomic_read(&conf
->pending_full_writes
) == 0)) {
4076 sh
= list_entry(conf
->hold_list
.next
,
4078 conf
->bypass_count
-= conf
->bypass_threshold
;
4079 if (conf
->bypass_count
< 0)
4080 conf
->bypass_count
= 0;
4084 list_del_init(&sh
->lru
);
4085 atomic_inc(&sh
->count
);
4086 BUG_ON(atomic_read(&sh
->count
) != 1);
4090 struct raid5_plug_cb
{
4091 struct blk_plug_cb cb
;
4092 struct list_head list
;
4095 static void raid5_unplug(struct blk_plug_cb
*blk_cb
, bool from_schedule
)
4097 struct raid5_plug_cb
*cb
= container_of(
4098 blk_cb
, struct raid5_plug_cb
, cb
);
4099 struct stripe_head
*sh
;
4100 struct mddev
*mddev
= cb
->cb
.data
;
4101 struct r5conf
*conf
= mddev
->private;
4104 if (cb
->list
.next
&& !list_empty(&cb
->list
)) {
4105 spin_lock_irq(&conf
->device_lock
);
4106 while (!list_empty(&cb
->list
)) {
4107 sh
= list_first_entry(&cb
->list
, struct stripe_head
, lru
);
4108 list_del_init(&sh
->lru
);
4110 * avoid race release_stripe_plug() sees
4111 * STRIPE_ON_UNPLUG_LIST clear but the stripe
4112 * is still in our list
4114 smp_mb__before_clear_bit();
4115 clear_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
);
4116 __release_stripe(conf
, sh
);
4119 spin_unlock_irq(&conf
->device_lock
);
4121 trace_block_unplug(mddev
->queue
, cnt
, !from_schedule
);
4125 static void release_stripe_plug(struct mddev
*mddev
,
4126 struct stripe_head
*sh
)
4128 struct blk_plug_cb
*blk_cb
= blk_check_plugged(
4129 raid5_unplug
, mddev
,
4130 sizeof(struct raid5_plug_cb
));
4131 struct raid5_plug_cb
*cb
;
4138 cb
= container_of(blk_cb
, struct raid5_plug_cb
, cb
);
4140 if (cb
->list
.next
== NULL
)
4141 INIT_LIST_HEAD(&cb
->list
);
4143 if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST
, &sh
->state
))
4144 list_add_tail(&sh
->lru
, &cb
->list
);
4149 static void make_discard_request(struct mddev
*mddev
, struct bio
*bi
)
4151 struct r5conf
*conf
= mddev
->private;
4152 sector_t logical_sector
, last_sector
;
4153 struct stripe_head
*sh
;
4157 if (mddev
->reshape_position
!= MaxSector
)
4158 /* Skip discard while reshape is happening */
4161 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4162 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4165 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4167 stripe_sectors
= conf
->chunk_sectors
*
4168 (conf
->raid_disks
- conf
->max_degraded
);
4169 logical_sector
= DIV_ROUND_UP_SECTOR_T(logical_sector
,
4171 sector_div(last_sector
, stripe_sectors
);
4173 logical_sector
*= conf
->chunk_sectors
;
4174 last_sector
*= conf
->chunk_sectors
;
4176 for (; logical_sector
< last_sector
;
4177 logical_sector
+= STRIPE_SECTORS
) {
4181 sh
= get_active_stripe(conf
, logical_sector
, 0, 0, 0);
4182 prepare_to_wait(&conf
->wait_for_overlap
, &w
,
4183 TASK_UNINTERRUPTIBLE
);
4184 spin_lock_irq(&sh
->stripe_lock
);
4185 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4186 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4188 if (sh
->dev
[d
].towrite
|| sh
->dev
[d
].toread
) {
4189 set_bit(R5_Overlap
, &sh
->dev
[d
].flags
);
4190 spin_unlock_irq(&sh
->stripe_lock
);
4196 finish_wait(&conf
->wait_for_overlap
, &w
);
4197 for (d
= 0; d
< conf
->raid_disks
; d
++) {
4198 if (d
== sh
->pd_idx
|| d
== sh
->qd_idx
)
4200 sh
->dev
[d
].towrite
= bi
;
4201 set_bit(R5_OVERWRITE
, &sh
->dev
[d
].flags
);
4202 raid5_inc_bi_active_stripes(bi
);
4204 spin_unlock_irq(&sh
->stripe_lock
);
4205 if (conf
->mddev
->bitmap
) {
4207 d
< conf
->raid_disks
- conf
->max_degraded
;
4209 bitmap_startwrite(mddev
->bitmap
,
4213 sh
->bm_seq
= conf
->seq_flush
+ 1;
4214 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
4217 set_bit(STRIPE_HANDLE
, &sh
->state
);
4218 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4219 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4220 atomic_inc(&conf
->preread_active_stripes
);
4221 release_stripe_plug(mddev
, sh
);
4224 remaining
= raid5_dec_bi_active_stripes(bi
);
4225 if (remaining
== 0) {
4226 md_write_end(mddev
);
4231 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
4233 struct r5conf
*conf
= mddev
->private;
4235 sector_t new_sector
;
4236 sector_t logical_sector
, last_sector
;
4237 struct stripe_head
*sh
;
4238 const int rw
= bio_data_dir(bi
);
4241 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
4242 md_flush_request(mddev
, bi
);
4246 md_write_start(mddev
, bi
);
4249 mddev
->reshape_position
== MaxSector
&&
4250 chunk_aligned_read(mddev
,bi
))
4253 if (unlikely(bi
->bi_rw
& REQ_DISCARD
)) {
4254 make_discard_request(mddev
, bi
);
4258 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4259 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
4261 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
4263 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
4269 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
4270 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
4271 /* spinlock is needed as reshape_progress may be
4272 * 64bit on a 32bit platform, and so it might be
4273 * possible to see a half-updated value
4274 * Of course reshape_progress could change after
4275 * the lock is dropped, so once we get a reference
4276 * to the stripe that we think it is, we will have
4279 spin_lock_irq(&conf
->device_lock
);
4280 if (mddev
->reshape_backwards
4281 ? logical_sector
< conf
->reshape_progress
4282 : logical_sector
>= conf
->reshape_progress
) {
4285 if (mddev
->reshape_backwards
4286 ? logical_sector
< conf
->reshape_safe
4287 : logical_sector
>= conf
->reshape_safe
) {
4288 spin_unlock_irq(&conf
->device_lock
);
4293 spin_unlock_irq(&conf
->device_lock
);
4296 new_sector
= raid5_compute_sector(conf
, logical_sector
,
4299 pr_debug("raid456: make_request, sector %llu logical %llu\n",
4300 (unsigned long long)new_sector
,
4301 (unsigned long long)logical_sector
);
4303 sh
= get_active_stripe(conf
, new_sector
, previous
,
4304 (bi
->bi_rw
&RWA_MASK
), 0);
4306 if (unlikely(previous
)) {
4307 /* expansion might have moved on while waiting for a
4308 * stripe, so we must do the range check again.
4309 * Expansion could still move past after this
4310 * test, but as we are holding a reference to
4311 * 'sh', we know that if that happens,
4312 * STRIPE_EXPANDING will get set and the expansion
4313 * won't proceed until we finish with the stripe.
4316 spin_lock_irq(&conf
->device_lock
);
4317 if (mddev
->reshape_backwards
4318 ? logical_sector
>= conf
->reshape_progress
4319 : logical_sector
< conf
->reshape_progress
)
4320 /* mismatch, need to try again */
4322 spin_unlock_irq(&conf
->device_lock
);
4331 logical_sector
>= mddev
->suspend_lo
&&
4332 logical_sector
< mddev
->suspend_hi
) {
4334 /* As the suspend_* range is controlled by
4335 * userspace, we want an interruptible
4338 flush_signals(current
);
4339 prepare_to_wait(&conf
->wait_for_overlap
,
4340 &w
, TASK_INTERRUPTIBLE
);
4341 if (logical_sector
>= mddev
->suspend_lo
&&
4342 logical_sector
< mddev
->suspend_hi
)
4347 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
4348 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
4349 /* Stripe is busy expanding or
4350 * add failed due to overlap. Flush everything
4353 md_wakeup_thread(mddev
->thread
);
4358 finish_wait(&conf
->wait_for_overlap
, &w
);
4359 set_bit(STRIPE_HANDLE
, &sh
->state
);
4360 clear_bit(STRIPE_DELAYED
, &sh
->state
);
4361 if ((bi
->bi_rw
& REQ_SYNC
) &&
4362 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
4363 atomic_inc(&conf
->preread_active_stripes
);
4364 release_stripe_plug(mddev
, sh
);
4366 /* cannot get stripe for read-ahead, just give-up */
4367 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
4368 finish_wait(&conf
->wait_for_overlap
, &w
);
4373 remaining
= raid5_dec_bi_active_stripes(bi
);
4374 if (remaining
== 0) {
4377 md_write_end(mddev
);
4379 trace_block_bio_complete(bdev_get_queue(bi
->bi_bdev
),
4385 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
4387 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
4389 /* reshaping is quite different to recovery/resync so it is
4390 * handled quite separately ... here.
4392 * On each call to sync_request, we gather one chunk worth of
4393 * destination stripes and flag them as expanding.
4394 * Then we find all the source stripes and request reads.
4395 * As the reads complete, handle_stripe will copy the data
4396 * into the destination stripe and release that stripe.
4398 struct r5conf
*conf
= mddev
->private;
4399 struct stripe_head
*sh
;
4400 sector_t first_sector
, last_sector
;
4401 int raid_disks
= conf
->previous_raid_disks
;
4402 int data_disks
= raid_disks
- conf
->max_degraded
;
4403 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
4406 sector_t writepos
, readpos
, safepos
;
4407 sector_t stripe_addr
;
4408 int reshape_sectors
;
4409 struct list_head stripes
;
4411 if (sector_nr
== 0) {
4412 /* If restarting in the middle, skip the initial sectors */
4413 if (mddev
->reshape_backwards
&&
4414 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
4415 sector_nr
= raid5_size(mddev
, 0, 0)
4416 - conf
->reshape_progress
;
4417 } else if (!mddev
->reshape_backwards
&&
4418 conf
->reshape_progress
> 0)
4419 sector_nr
= conf
->reshape_progress
;
4420 sector_div(sector_nr
, new_data_disks
);
4422 mddev
->curr_resync_completed
= sector_nr
;
4423 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4429 /* We need to process a full chunk at a time.
4430 * If old and new chunk sizes differ, we need to process the
4433 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
4434 reshape_sectors
= mddev
->new_chunk_sectors
;
4436 reshape_sectors
= mddev
->chunk_sectors
;
4438 /* We update the metadata at least every 10 seconds, or when
4439 * the data about to be copied would over-write the source of
4440 * the data at the front of the range. i.e. one new_stripe
4441 * along from reshape_progress new_maps to after where
4442 * reshape_safe old_maps to
4444 writepos
= conf
->reshape_progress
;
4445 sector_div(writepos
, new_data_disks
);
4446 readpos
= conf
->reshape_progress
;
4447 sector_div(readpos
, data_disks
);
4448 safepos
= conf
->reshape_safe
;
4449 sector_div(safepos
, data_disks
);
4450 if (mddev
->reshape_backwards
) {
4451 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
4452 readpos
+= reshape_sectors
;
4453 safepos
+= reshape_sectors
;
4455 writepos
+= reshape_sectors
;
4456 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
4457 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
4460 /* Having calculated the 'writepos' possibly use it
4461 * to set 'stripe_addr' which is where we will write to.
4463 if (mddev
->reshape_backwards
) {
4464 BUG_ON(conf
->reshape_progress
== 0);
4465 stripe_addr
= writepos
;
4466 BUG_ON((mddev
->dev_sectors
&
4467 ~((sector_t
)reshape_sectors
- 1))
4468 - reshape_sectors
- stripe_addr
4471 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4472 stripe_addr
= sector_nr
;
4475 /* 'writepos' is the most advanced device address we might write.
4476 * 'readpos' is the least advanced device address we might read.
4477 * 'safepos' is the least address recorded in the metadata as having
4479 * If there is a min_offset_diff, these are adjusted either by
4480 * increasing the safepos/readpos if diff is negative, or
4481 * increasing writepos if diff is positive.
4482 * If 'readpos' is then behind 'writepos', there is no way that we can
4483 * ensure safety in the face of a crash - that must be done by userspace
4484 * making a backup of the data. So in that case there is no particular
4485 * rush to update metadata.
4486 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4487 * update the metadata to advance 'safepos' to match 'readpos' so that
4488 * we can be safe in the event of a crash.
4489 * So we insist on updating metadata if safepos is behind writepos and
4490 * readpos is beyond writepos.
4491 * In any case, update the metadata every 10 seconds.
4492 * Maybe that number should be configurable, but I'm not sure it is
4493 * worth it.... maybe it could be a multiple of safemode_delay???
4495 if (conf
->min_offset_diff
< 0) {
4496 safepos
+= -conf
->min_offset_diff
;
4497 readpos
+= -conf
->min_offset_diff
;
4499 writepos
+= conf
->min_offset_diff
;
4501 if ((mddev
->reshape_backwards
4502 ? (safepos
> writepos
&& readpos
< writepos
)
4503 : (safepos
< writepos
&& readpos
> writepos
)) ||
4504 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4505 /* Cannot proceed until we've updated the superblock... */
4506 wait_event(conf
->wait_for_overlap
,
4507 atomic_read(&conf
->reshape_stripes
)==0);
4508 mddev
->reshape_position
= conf
->reshape_progress
;
4509 mddev
->curr_resync_completed
= sector_nr
;
4510 conf
->reshape_checkpoint
= jiffies
;
4511 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4512 md_wakeup_thread(mddev
->thread
);
4513 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4514 kthread_should_stop());
4515 spin_lock_irq(&conf
->device_lock
);
4516 conf
->reshape_safe
= mddev
->reshape_position
;
4517 spin_unlock_irq(&conf
->device_lock
);
4518 wake_up(&conf
->wait_for_overlap
);
4519 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4522 INIT_LIST_HEAD(&stripes
);
4523 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4525 int skipped_disk
= 0;
4526 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4527 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4528 atomic_inc(&conf
->reshape_stripes
);
4529 /* If any of this stripe is beyond the end of the old
4530 * array, then we need to zero those blocks
4532 for (j
=sh
->disks
; j
--;) {
4534 if (j
== sh
->pd_idx
)
4536 if (conf
->level
== 6 &&
4539 s
= compute_blocknr(sh
, j
, 0);
4540 if (s
< raid5_size(mddev
, 0, 0)) {
4544 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4545 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4546 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4548 if (!skipped_disk
) {
4549 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4550 set_bit(STRIPE_HANDLE
, &sh
->state
);
4552 list_add(&sh
->lru
, &stripes
);
4554 spin_lock_irq(&conf
->device_lock
);
4555 if (mddev
->reshape_backwards
)
4556 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4558 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4559 spin_unlock_irq(&conf
->device_lock
);
4560 /* Ok, those stripe are ready. We can start scheduling
4561 * reads on the source stripes.
4562 * The source stripes are determined by mapping the first and last
4563 * block on the destination stripes.
4566 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4569 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4570 * new_data_disks
- 1),
4572 if (last_sector
>= mddev
->dev_sectors
)
4573 last_sector
= mddev
->dev_sectors
- 1;
4574 while (first_sector
<= last_sector
) {
4575 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4576 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4577 set_bit(STRIPE_HANDLE
, &sh
->state
);
4579 first_sector
+= STRIPE_SECTORS
;
4581 /* Now that the sources are clearly marked, we can release
4582 * the destination stripes
4584 while (!list_empty(&stripes
)) {
4585 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4586 list_del_init(&sh
->lru
);
4589 /* If this takes us to the resync_max point where we have to pause,
4590 * then we need to write out the superblock.
4592 sector_nr
+= reshape_sectors
;
4593 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4594 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4595 /* Cannot proceed until we've updated the superblock... */
4596 wait_event(conf
->wait_for_overlap
,
4597 atomic_read(&conf
->reshape_stripes
) == 0);
4598 mddev
->reshape_position
= conf
->reshape_progress
;
4599 mddev
->curr_resync_completed
= sector_nr
;
4600 conf
->reshape_checkpoint
= jiffies
;
4601 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4602 md_wakeup_thread(mddev
->thread
);
4603 wait_event(mddev
->sb_wait
,
4604 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4605 || kthread_should_stop());
4606 spin_lock_irq(&conf
->device_lock
);
4607 conf
->reshape_safe
= mddev
->reshape_position
;
4608 spin_unlock_irq(&conf
->device_lock
);
4609 wake_up(&conf
->wait_for_overlap
);
4610 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4612 return reshape_sectors
;
4615 /* FIXME go_faster isn't used */
4616 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4618 struct r5conf
*conf
= mddev
->private;
4619 struct stripe_head
*sh
;
4620 sector_t max_sector
= mddev
->dev_sectors
;
4621 sector_t sync_blocks
;
4622 int still_degraded
= 0;
4625 if (sector_nr
>= max_sector
) {
4626 /* just being told to finish up .. nothing much to do */
4628 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4633 if (mddev
->curr_resync
< max_sector
) /* aborted */
4634 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4636 else /* completed sync */
4638 bitmap_close_sync(mddev
->bitmap
);
4643 /* Allow raid5_quiesce to complete */
4644 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4646 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4647 return reshape_request(mddev
, sector_nr
, skipped
);
4649 /* No need to check resync_max as we never do more than one
4650 * stripe, and as resync_max will always be on a chunk boundary,
4651 * if the check in md_do_sync didn't fire, there is no chance
4652 * of overstepping resync_max here
4655 /* if there is too many failed drives and we are trying
4656 * to resync, then assert that we are finished, because there is
4657 * nothing we can do.
4659 if (mddev
->degraded
>= conf
->max_degraded
&&
4660 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4661 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4665 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4666 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4667 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4668 /* we can skip this block, and probably more */
4669 sync_blocks
/= STRIPE_SECTORS
;
4671 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4674 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4676 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4678 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4679 /* make sure we don't swamp the stripe cache if someone else
4680 * is trying to get access
4682 schedule_timeout_uninterruptible(1);
4684 /* Need to check if array will still be degraded after recovery/resync
4685 * We don't need to check the 'failed' flag as when that gets set,
4688 for (i
= 0; i
< conf
->raid_disks
; i
++)
4689 if (conf
->disks
[i
].rdev
== NULL
)
4692 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4694 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4699 return STRIPE_SECTORS
;
4702 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4704 /* We may not be able to submit a whole bio at once as there
4705 * may not be enough stripe_heads available.
4706 * We cannot pre-allocate enough stripe_heads as we may need
4707 * more than exist in the cache (if we allow ever large chunks).
4708 * So we do one stripe head at a time and record in
4709 * ->bi_hw_segments how many have been done.
4711 * We *know* that this entire raid_bio is in one chunk, so
4712 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4714 struct stripe_head
*sh
;
4716 sector_t sector
, logical_sector
, last_sector
;
4721 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4722 sector
= raid5_compute_sector(conf
, logical_sector
,
4724 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4726 for (; logical_sector
< last_sector
;
4727 logical_sector
+= STRIPE_SECTORS
,
4728 sector
+= STRIPE_SECTORS
,
4731 if (scnt
< raid5_bi_processed_stripes(raid_bio
))
4732 /* already done this stripe */
4735 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4738 /* failed to get a stripe - must wait */
4739 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4740 conf
->retry_read_aligned
= raid_bio
;
4744 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4746 raid5_set_bi_processed_stripes(raid_bio
, scnt
);
4747 conf
->retry_read_aligned
= raid_bio
;
4751 set_bit(R5_ReadNoMerge
, &sh
->dev
[dd_idx
].flags
);
4756 remaining
= raid5_dec_bi_active_stripes(raid_bio
);
4757 if (remaining
== 0) {
4758 trace_block_bio_complete(bdev_get_queue(raid_bio
->bi_bdev
),
4760 bio_endio(raid_bio
, 0);
4762 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4763 wake_up(&conf
->wait_for_stripe
);
4767 #define MAX_STRIPE_BATCH 8
4768 static int handle_active_stripes(struct r5conf
*conf
)
4770 struct stripe_head
*batch
[MAX_STRIPE_BATCH
], *sh
;
4771 int i
, batch_size
= 0;
4773 while (batch_size
< MAX_STRIPE_BATCH
&&
4774 (sh
= __get_priority_stripe(conf
)) != NULL
)
4775 batch
[batch_size
++] = sh
;
4777 if (batch_size
== 0)
4779 spin_unlock_irq(&conf
->device_lock
);
4781 for (i
= 0; i
< batch_size
; i
++)
4782 handle_stripe(batch
[i
]);
4786 spin_lock_irq(&conf
->device_lock
);
4787 for (i
= 0; i
< batch_size
; i
++)
4788 __release_stripe(conf
, batch
[i
]);
4793 * This is our raid5 kernel thread.
4795 * We scan the hash table for stripes which can be handled now.
4796 * During the scan, completed stripes are saved for us by the interrupt
4797 * handler, so that they will not have to wait for our next wakeup.
4799 static void raid5d(struct md_thread
*thread
)
4801 struct mddev
*mddev
= thread
->mddev
;
4802 struct r5conf
*conf
= mddev
->private;
4804 struct blk_plug plug
;
4806 pr_debug("+++ raid5d active\n");
4808 md_check_recovery(mddev
);
4810 blk_start_plug(&plug
);
4812 spin_lock_irq(&conf
->device_lock
);
4818 !list_empty(&conf
->bitmap_list
)) {
4819 /* Now is a good time to flush some bitmap updates */
4821 spin_unlock_irq(&conf
->device_lock
);
4822 bitmap_unplug(mddev
->bitmap
);
4823 spin_lock_irq(&conf
->device_lock
);
4824 conf
->seq_write
= conf
->seq_flush
;
4825 activate_bit_delay(conf
);
4827 raid5_activate_delayed(conf
);
4829 while ((bio
= remove_bio_from_retry(conf
))) {
4831 spin_unlock_irq(&conf
->device_lock
);
4832 ok
= retry_aligned_read(conf
, bio
);
4833 spin_lock_irq(&conf
->device_lock
);
4839 batch_size
= handle_active_stripes(conf
);
4842 handled
+= batch_size
;
4844 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
)) {
4845 spin_unlock_irq(&conf
->device_lock
);
4846 md_check_recovery(mddev
);
4847 spin_lock_irq(&conf
->device_lock
);
4850 pr_debug("%d stripes handled\n", handled
);
4852 spin_unlock_irq(&conf
->device_lock
);
4854 async_tx_issue_pending_all();
4855 blk_finish_plug(&plug
);
4857 pr_debug("--- raid5d inactive\n");
4861 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4863 struct r5conf
*conf
= mddev
->private;
4865 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4871 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4873 struct r5conf
*conf
= mddev
->private;
4876 if (size
<= 16 || size
> 32768)
4878 while (size
< conf
->max_nr_stripes
) {
4879 if (drop_one_stripe(conf
))
4880 conf
->max_nr_stripes
--;
4884 err
= md_allow_write(mddev
);
4887 while (size
> conf
->max_nr_stripes
) {
4888 if (grow_one_stripe(conf
))
4889 conf
->max_nr_stripes
++;
4894 EXPORT_SYMBOL(raid5_set_cache_size
);
4897 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4899 struct r5conf
*conf
= mddev
->private;
4903 if (len
>= PAGE_SIZE
)
4908 if (strict_strtoul(page
, 10, &new))
4910 err
= raid5_set_cache_size(mddev
, new);
4916 static struct md_sysfs_entry
4917 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4918 raid5_show_stripe_cache_size
,
4919 raid5_store_stripe_cache_size
);
4922 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4924 struct r5conf
*conf
= mddev
->private;
4926 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4932 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4934 struct r5conf
*conf
= mddev
->private;
4936 if (len
>= PAGE_SIZE
)
4941 if (strict_strtoul(page
, 10, &new))
4943 if (new > conf
->max_nr_stripes
)
4945 conf
->bypass_threshold
= new;
4949 static struct md_sysfs_entry
4950 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4952 raid5_show_preread_threshold
,
4953 raid5_store_preread_threshold
);
4956 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4958 struct r5conf
*conf
= mddev
->private;
4960 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4965 static struct md_sysfs_entry
4966 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4968 static struct attribute
*raid5_attrs
[] = {
4969 &raid5_stripecache_size
.attr
,
4970 &raid5_stripecache_active
.attr
,
4971 &raid5_preread_bypass_threshold
.attr
,
4974 static struct attribute_group raid5_attrs_group
= {
4976 .attrs
= raid5_attrs
,
4980 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4982 struct r5conf
*conf
= mddev
->private;
4985 sectors
= mddev
->dev_sectors
;
4987 /* size is defined by the smallest of previous and new size */
4988 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4990 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4991 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4992 return sectors
* (raid_disks
- conf
->max_degraded
);
4995 static void raid5_free_percpu(struct r5conf
*conf
)
4997 struct raid5_percpu
*percpu
;
5004 for_each_possible_cpu(cpu
) {
5005 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5006 safe_put_page(percpu
->spare_page
);
5007 kfree(percpu
->scribble
);
5009 #ifdef CONFIG_HOTPLUG_CPU
5010 unregister_cpu_notifier(&conf
->cpu_notify
);
5014 free_percpu(conf
->percpu
);
5017 static void free_conf(struct r5conf
*conf
)
5019 shrink_stripes(conf
);
5020 raid5_free_percpu(conf
);
5022 kfree(conf
->stripe_hashtbl
);
5026 #ifdef CONFIG_HOTPLUG_CPU
5027 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
5030 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
5031 long cpu
= (long)hcpu
;
5032 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
5035 case CPU_UP_PREPARE
:
5036 case CPU_UP_PREPARE_FROZEN
:
5037 if (conf
->level
== 6 && !percpu
->spare_page
)
5038 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
5039 if (!percpu
->scribble
)
5040 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5042 if (!percpu
->scribble
||
5043 (conf
->level
== 6 && !percpu
->spare_page
)) {
5044 safe_put_page(percpu
->spare_page
);
5045 kfree(percpu
->scribble
);
5046 pr_err("%s: failed memory allocation for cpu%ld\n",
5048 return notifier_from_errno(-ENOMEM
);
5052 case CPU_DEAD_FROZEN
:
5053 safe_put_page(percpu
->spare_page
);
5054 kfree(percpu
->scribble
);
5055 percpu
->spare_page
= NULL
;
5056 percpu
->scribble
= NULL
;
5065 static int raid5_alloc_percpu(struct r5conf
*conf
)
5068 struct page
*spare_page
;
5069 struct raid5_percpu __percpu
*allcpus
;
5073 allcpus
= alloc_percpu(struct raid5_percpu
);
5076 conf
->percpu
= allcpus
;
5080 for_each_present_cpu(cpu
) {
5081 if (conf
->level
== 6) {
5082 spare_page
= alloc_page(GFP_KERNEL
);
5087 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
5089 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
5094 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
5096 #ifdef CONFIG_HOTPLUG_CPU
5097 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
5098 conf
->cpu_notify
.priority
= 0;
5100 err
= register_cpu_notifier(&conf
->cpu_notify
);
5107 static struct r5conf
*setup_conf(struct mddev
*mddev
)
5109 struct r5conf
*conf
;
5110 int raid_disk
, memory
, max_disks
;
5111 struct md_rdev
*rdev
;
5112 struct disk_info
*disk
;
5115 if (mddev
->new_level
!= 5
5116 && mddev
->new_level
!= 4
5117 && mddev
->new_level
!= 6) {
5118 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
5119 mdname(mddev
), mddev
->new_level
);
5120 return ERR_PTR(-EIO
);
5122 if ((mddev
->new_level
== 5
5123 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
5124 (mddev
->new_level
== 6
5125 && !algorithm_valid_raid6(mddev
->new_layout
))) {
5126 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
5127 mdname(mddev
), mddev
->new_layout
);
5128 return ERR_PTR(-EIO
);
5130 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
5131 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
5132 mdname(mddev
), mddev
->raid_disks
);
5133 return ERR_PTR(-EINVAL
);
5136 if (!mddev
->new_chunk_sectors
||
5137 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
5138 !is_power_of_2(mddev
->new_chunk_sectors
)) {
5139 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
5140 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
5141 return ERR_PTR(-EINVAL
);
5144 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
5147 spin_lock_init(&conf
->device_lock
);
5148 init_waitqueue_head(&conf
->wait_for_stripe
);
5149 init_waitqueue_head(&conf
->wait_for_overlap
);
5150 INIT_LIST_HEAD(&conf
->handle_list
);
5151 INIT_LIST_HEAD(&conf
->hold_list
);
5152 INIT_LIST_HEAD(&conf
->delayed_list
);
5153 INIT_LIST_HEAD(&conf
->bitmap_list
);
5154 INIT_LIST_HEAD(&conf
->inactive_list
);
5155 atomic_set(&conf
->active_stripes
, 0);
5156 atomic_set(&conf
->preread_active_stripes
, 0);
5157 atomic_set(&conf
->active_aligned_reads
, 0);
5158 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
5159 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
5161 conf
->raid_disks
= mddev
->raid_disks
;
5162 if (mddev
->reshape_position
== MaxSector
)
5163 conf
->previous_raid_disks
= mddev
->raid_disks
;
5165 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5166 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
5167 conf
->scribble_len
= scribble_len(max_disks
);
5169 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
5174 conf
->mddev
= mddev
;
5176 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
5179 conf
->level
= mddev
->new_level
;
5180 if (raid5_alloc_percpu(conf
) != 0)
5183 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
5185 rdev_for_each(rdev
, mddev
) {
5186 raid_disk
= rdev
->raid_disk
;
5187 if (raid_disk
>= max_disks
5190 disk
= conf
->disks
+ raid_disk
;
5192 if (test_bit(Replacement
, &rdev
->flags
)) {
5193 if (disk
->replacement
)
5195 disk
->replacement
= rdev
;
5202 if (test_bit(In_sync
, &rdev
->flags
)) {
5203 char b
[BDEVNAME_SIZE
];
5204 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
5206 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
5207 } else if (rdev
->saved_raid_disk
!= raid_disk
)
5208 /* Cannot rely on bitmap to complete recovery */
5212 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5213 conf
->level
= mddev
->new_level
;
5214 if (conf
->level
== 6)
5215 conf
->max_degraded
= 2;
5217 conf
->max_degraded
= 1;
5218 conf
->algorithm
= mddev
->new_layout
;
5219 conf
->max_nr_stripes
= NR_STRIPES
;
5220 conf
->reshape_progress
= mddev
->reshape_position
;
5221 if (conf
->reshape_progress
!= MaxSector
) {
5222 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
5223 conf
->prev_algo
= mddev
->layout
;
5226 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
5227 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
5228 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
5230 "md/raid:%s: couldn't allocate %dkB for buffers\n",
5231 mdname(mddev
), memory
);
5234 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
5235 mdname(mddev
), memory
);
5237 sprintf(pers_name
, "raid%d", mddev
->new_level
);
5238 conf
->thread
= md_register_thread(raid5d
, mddev
, pers_name
);
5239 if (!conf
->thread
) {
5241 "md/raid:%s: couldn't allocate thread.\n",
5251 return ERR_PTR(-EIO
);
5253 return ERR_PTR(-ENOMEM
);
5257 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
5260 case ALGORITHM_PARITY_0
:
5261 if (raid_disk
< max_degraded
)
5264 case ALGORITHM_PARITY_N
:
5265 if (raid_disk
>= raid_disks
- max_degraded
)
5268 case ALGORITHM_PARITY_0_6
:
5269 if (raid_disk
== 0 ||
5270 raid_disk
== raid_disks
- 1)
5273 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5274 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5275 case ALGORITHM_LEFT_SYMMETRIC_6
:
5276 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5277 if (raid_disk
== raid_disks
- 1)
5283 static int run(struct mddev
*mddev
)
5285 struct r5conf
*conf
;
5286 int working_disks
= 0;
5287 int dirty_parity_disks
= 0;
5288 struct md_rdev
*rdev
;
5289 sector_t reshape_offset
= 0;
5291 long long min_offset_diff
= 0;
5294 if (mddev
->recovery_cp
!= MaxSector
)
5295 printk(KERN_NOTICE
"md/raid:%s: not clean"
5296 " -- starting background reconstruction\n",
5299 rdev_for_each(rdev
, mddev
) {
5301 if (rdev
->raid_disk
< 0)
5303 diff
= (rdev
->new_data_offset
- rdev
->data_offset
);
5305 min_offset_diff
= diff
;
5307 } else if (mddev
->reshape_backwards
&&
5308 diff
< min_offset_diff
)
5309 min_offset_diff
= diff
;
5310 else if (!mddev
->reshape_backwards
&&
5311 diff
> min_offset_diff
)
5312 min_offset_diff
= diff
;
5315 if (mddev
->reshape_position
!= MaxSector
) {
5316 /* Check that we can continue the reshape.
5317 * Difficulties arise if the stripe we would write to
5318 * next is at or after the stripe we would read from next.
5319 * For a reshape that changes the number of devices, this
5320 * is only possible for a very short time, and mdadm makes
5321 * sure that time appears to have past before assembling
5322 * the array. So we fail if that time hasn't passed.
5323 * For a reshape that keeps the number of devices the same
5324 * mdadm must be monitoring the reshape can keeping the
5325 * critical areas read-only and backed up. It will start
5326 * the array in read-only mode, so we check for that.
5328 sector_t here_new
, here_old
;
5330 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
5332 if (mddev
->new_level
!= mddev
->level
) {
5333 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
5334 "required - aborting.\n",
5338 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
5339 /* reshape_position must be on a new-stripe boundary, and one
5340 * further up in new geometry must map after here in old
5343 here_new
= mddev
->reshape_position
;
5344 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
5345 (mddev
->raid_disks
- max_degraded
))) {
5346 printk(KERN_ERR
"md/raid:%s: reshape_position not "
5347 "on a stripe boundary\n", mdname(mddev
));
5350 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
5351 /* here_new is the stripe we will write to */
5352 here_old
= mddev
->reshape_position
;
5353 sector_div(here_old
, mddev
->chunk_sectors
*
5354 (old_disks
-max_degraded
));
5355 /* here_old is the first stripe that we might need to read
5357 if (mddev
->delta_disks
== 0) {
5358 if ((here_new
* mddev
->new_chunk_sectors
!=
5359 here_old
* mddev
->chunk_sectors
)) {
5360 printk(KERN_ERR
"md/raid:%s: reshape position is"
5361 " confused - aborting\n", mdname(mddev
));
5364 /* We cannot be sure it is safe to start an in-place
5365 * reshape. It is only safe if user-space is monitoring
5366 * and taking constant backups.
5367 * mdadm always starts a situation like this in
5368 * readonly mode so it can take control before
5369 * allowing any writes. So just check for that.
5371 if (abs(min_offset_diff
) >= mddev
->chunk_sectors
&&
5372 abs(min_offset_diff
) >= mddev
->new_chunk_sectors
)
5373 /* not really in-place - so OK */;
5374 else if (mddev
->ro
== 0) {
5375 printk(KERN_ERR
"md/raid:%s: in-place reshape "
5376 "must be started in read-only mode "
5381 } else if (mddev
->reshape_backwards
5382 ? (here_new
* mddev
->new_chunk_sectors
+ min_offset_diff
<=
5383 here_old
* mddev
->chunk_sectors
)
5384 : (here_new
* mddev
->new_chunk_sectors
>=
5385 here_old
* mddev
->chunk_sectors
+ (-min_offset_diff
))) {
5386 /* Reading from the same stripe as writing to - bad */
5387 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
5388 "auto-recovery - aborting.\n",
5392 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
5394 /* OK, we should be able to continue; */
5396 BUG_ON(mddev
->level
!= mddev
->new_level
);
5397 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
5398 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
5399 BUG_ON(mddev
->delta_disks
!= 0);
5402 if (mddev
->private == NULL
)
5403 conf
= setup_conf(mddev
);
5405 conf
= mddev
->private;
5408 return PTR_ERR(conf
);
5410 conf
->min_offset_diff
= min_offset_diff
;
5411 mddev
->thread
= conf
->thread
;
5412 conf
->thread
= NULL
;
5413 mddev
->private = conf
;
5415 for (i
= 0; i
< conf
->raid_disks
&& conf
->previous_raid_disks
;
5417 rdev
= conf
->disks
[i
].rdev
;
5418 if (!rdev
&& conf
->disks
[i
].replacement
) {
5419 /* The replacement is all we have yet */
5420 rdev
= conf
->disks
[i
].replacement
;
5421 conf
->disks
[i
].replacement
= NULL
;
5422 clear_bit(Replacement
, &rdev
->flags
);
5423 conf
->disks
[i
].rdev
= rdev
;
5427 if (conf
->disks
[i
].replacement
&&
5428 conf
->reshape_progress
!= MaxSector
) {
5429 /* replacements and reshape simply do not mix. */
5430 printk(KERN_ERR
"md: cannot handle concurrent "
5431 "replacement and reshape.\n");
5434 if (test_bit(In_sync
, &rdev
->flags
)) {
5438 /* This disc is not fully in-sync. However if it
5439 * just stored parity (beyond the recovery_offset),
5440 * when we don't need to be concerned about the
5441 * array being dirty.
5442 * When reshape goes 'backwards', we never have
5443 * partially completed devices, so we only need
5444 * to worry about reshape going forwards.
5446 /* Hack because v0.91 doesn't store recovery_offset properly. */
5447 if (mddev
->major_version
== 0 &&
5448 mddev
->minor_version
> 90)
5449 rdev
->recovery_offset
= reshape_offset
;
5451 if (rdev
->recovery_offset
< reshape_offset
) {
5452 /* We need to check old and new layout */
5453 if (!only_parity(rdev
->raid_disk
,
5456 conf
->max_degraded
))
5459 if (!only_parity(rdev
->raid_disk
,
5461 conf
->previous_raid_disks
,
5462 conf
->max_degraded
))
5464 dirty_parity_disks
++;
5468 * 0 for a fully functional array, 1 or 2 for a degraded array.
5470 mddev
->degraded
= calc_degraded(conf
);
5472 if (has_failed(conf
)) {
5473 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
5474 " (%d/%d failed)\n",
5475 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
5479 /* device size must be a multiple of chunk size */
5480 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
5481 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
5483 if (mddev
->degraded
> dirty_parity_disks
&&
5484 mddev
->recovery_cp
!= MaxSector
) {
5485 if (mddev
->ok_start_degraded
)
5487 "md/raid:%s: starting dirty degraded array"
5488 " - data corruption possible.\n",
5492 "md/raid:%s: cannot start dirty degraded array.\n",
5498 if (mddev
->degraded
== 0)
5499 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
5500 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
5501 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
5504 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
5505 " out of %d devices, algorithm %d\n",
5506 mdname(mddev
), conf
->level
,
5507 mddev
->raid_disks
- mddev
->degraded
,
5508 mddev
->raid_disks
, mddev
->new_layout
);
5510 print_raid5_conf(conf
);
5512 if (conf
->reshape_progress
!= MaxSector
) {
5513 conf
->reshape_safe
= conf
->reshape_progress
;
5514 atomic_set(&conf
->reshape_stripes
, 0);
5515 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5516 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5517 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5518 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5519 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5524 /* Ok, everything is just fine now */
5525 if (mddev
->to_remove
== &raid5_attrs_group
)
5526 mddev
->to_remove
= NULL
;
5527 else if (mddev
->kobj
.sd
&&
5528 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
5530 "raid5: failed to create sysfs attributes for %s\n",
5532 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5536 bool discard_supported
= true;
5537 /* read-ahead size must cover two whole stripes, which
5538 * is 2 * (datadisks) * chunksize where 'n' is the
5539 * number of raid devices
5541 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
5542 int stripe
= data_disks
*
5543 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
5544 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5545 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5547 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
5549 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
5550 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
5552 chunk_size
= mddev
->chunk_sectors
<< 9;
5553 blk_queue_io_min(mddev
->queue
, chunk_size
);
5554 blk_queue_io_opt(mddev
->queue
, chunk_size
*
5555 (conf
->raid_disks
- conf
->max_degraded
));
5557 * We can only discard a whole stripe. It doesn't make sense to
5558 * discard data disk but write parity disk
5560 stripe
= stripe
* PAGE_SIZE
;
5561 /* Round up to power of 2, as discard handling
5562 * currently assumes that */
5563 while ((stripe
-1) & stripe
)
5564 stripe
= (stripe
| (stripe
-1)) + 1;
5565 mddev
->queue
->limits
.discard_alignment
= stripe
;
5566 mddev
->queue
->limits
.discard_granularity
= stripe
;
5568 * unaligned part of discard request will be ignored, so can't
5569 * guarantee discard_zerors_data
5571 mddev
->queue
->limits
.discard_zeroes_data
= 0;
5573 rdev_for_each(rdev
, mddev
) {
5574 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5575 rdev
->data_offset
<< 9);
5576 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
5577 rdev
->new_data_offset
<< 9);
5579 * discard_zeroes_data is required, otherwise data
5580 * could be lost. Consider a scenario: discard a stripe
5581 * (the stripe could be inconsistent if
5582 * discard_zeroes_data is 0); write one disk of the
5583 * stripe (the stripe could be inconsistent again
5584 * depending on which disks are used to calculate
5585 * parity); the disk is broken; The stripe data of this
5588 if (!blk_queue_discard(bdev_get_queue(rdev
->bdev
)) ||
5589 !bdev_get_queue(rdev
->bdev
)->
5590 limits
.discard_zeroes_data
)
5591 discard_supported
= false;
5594 if (discard_supported
&&
5595 mddev
->queue
->limits
.max_discard_sectors
>= stripe
&&
5596 mddev
->queue
->limits
.discard_granularity
>= stripe
)
5597 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
5600 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
5606 md_unregister_thread(&mddev
->thread
);
5607 print_raid5_conf(conf
);
5609 mddev
->private = NULL
;
5610 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5614 static int stop(struct mddev
*mddev
)
5616 struct r5conf
*conf
= mddev
->private;
5618 md_unregister_thread(&mddev
->thread
);
5620 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5622 mddev
->private = NULL
;
5623 mddev
->to_remove
= &raid5_attrs_group
;
5627 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5629 struct r5conf
*conf
= mddev
->private;
5632 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5633 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5634 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5635 for (i
= 0; i
< conf
->raid_disks
; i
++)
5636 seq_printf (seq
, "%s",
5637 conf
->disks
[i
].rdev
&&
5638 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5639 seq_printf (seq
, "]");
5642 static void print_raid5_conf (struct r5conf
*conf
)
5645 struct disk_info
*tmp
;
5647 printk(KERN_DEBUG
"RAID conf printout:\n");
5649 printk("(conf==NULL)\n");
5652 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5654 conf
->raid_disks
- conf
->mddev
->degraded
);
5656 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5657 char b
[BDEVNAME_SIZE
];
5658 tmp
= conf
->disks
+ i
;
5660 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5661 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5662 bdevname(tmp
->rdev
->bdev
, b
));
5666 static int raid5_spare_active(struct mddev
*mddev
)
5669 struct r5conf
*conf
= mddev
->private;
5670 struct disk_info
*tmp
;
5672 unsigned long flags
;
5674 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5675 tmp
= conf
->disks
+ i
;
5676 if (tmp
->replacement
5677 && tmp
->replacement
->recovery_offset
== MaxSector
5678 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
5679 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
5680 /* Replacement has just become active. */
5682 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
5685 /* Replaced device not technically faulty,
5686 * but we need to be sure it gets removed
5687 * and never re-added.
5689 set_bit(Faulty
, &tmp
->rdev
->flags
);
5690 sysfs_notify_dirent_safe(
5691 tmp
->rdev
->sysfs_state
);
5693 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
5694 } else if (tmp
->rdev
5695 && tmp
->rdev
->recovery_offset
== MaxSector
5696 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5697 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5699 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5702 spin_lock_irqsave(&conf
->device_lock
, flags
);
5703 mddev
->degraded
= calc_degraded(conf
);
5704 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5705 print_raid5_conf(conf
);
5709 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5711 struct r5conf
*conf
= mddev
->private;
5713 int number
= rdev
->raid_disk
;
5714 struct md_rdev
**rdevp
;
5715 struct disk_info
*p
= conf
->disks
+ number
;
5717 print_raid5_conf(conf
);
5718 if (rdev
== p
->rdev
)
5720 else if (rdev
== p
->replacement
)
5721 rdevp
= &p
->replacement
;
5725 if (number
>= conf
->raid_disks
&&
5726 conf
->reshape_progress
== MaxSector
)
5727 clear_bit(In_sync
, &rdev
->flags
);
5729 if (test_bit(In_sync
, &rdev
->flags
) ||
5730 atomic_read(&rdev
->nr_pending
)) {
5734 /* Only remove non-faulty devices if recovery
5737 if (!test_bit(Faulty
, &rdev
->flags
) &&
5738 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5739 !has_failed(conf
) &&
5740 (!p
->replacement
|| p
->replacement
== rdev
) &&
5741 number
< conf
->raid_disks
) {
5747 if (atomic_read(&rdev
->nr_pending
)) {
5748 /* lost the race, try later */
5751 } else if (p
->replacement
) {
5752 /* We must have just cleared 'rdev' */
5753 p
->rdev
= p
->replacement
;
5754 clear_bit(Replacement
, &p
->replacement
->flags
);
5755 smp_mb(); /* Make sure other CPUs may see both as identical
5756 * but will never see neither - if they are careful
5758 p
->replacement
= NULL
;
5759 clear_bit(WantReplacement
, &rdev
->flags
);
5761 /* We might have just removed the Replacement as faulty-
5762 * clear the bit just in case
5764 clear_bit(WantReplacement
, &rdev
->flags
);
5767 print_raid5_conf(conf
);
5771 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5773 struct r5conf
*conf
= mddev
->private;
5776 struct disk_info
*p
;
5778 int last
= conf
->raid_disks
- 1;
5780 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5783 if (rdev
->saved_raid_disk
< 0 && has_failed(conf
))
5784 /* no point adding a device */
5787 if (rdev
->raid_disk
>= 0)
5788 first
= last
= rdev
->raid_disk
;
5791 * find the disk ... but prefer rdev->saved_raid_disk
5794 if (rdev
->saved_raid_disk
>= 0 &&
5795 rdev
->saved_raid_disk
>= first
&&
5796 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5797 first
= rdev
->saved_raid_disk
;
5799 for (disk
= first
; disk
<= last
; disk
++) {
5800 p
= conf
->disks
+ disk
;
5801 if (p
->rdev
== NULL
) {
5802 clear_bit(In_sync
, &rdev
->flags
);
5803 rdev
->raid_disk
= disk
;
5805 if (rdev
->saved_raid_disk
!= disk
)
5807 rcu_assign_pointer(p
->rdev
, rdev
);
5811 for (disk
= first
; disk
<= last
; disk
++) {
5812 p
= conf
->disks
+ disk
;
5813 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
5814 p
->replacement
== NULL
) {
5815 clear_bit(In_sync
, &rdev
->flags
);
5816 set_bit(Replacement
, &rdev
->flags
);
5817 rdev
->raid_disk
= disk
;
5820 rcu_assign_pointer(p
->replacement
, rdev
);
5825 print_raid5_conf(conf
);
5829 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5831 /* no resync is happening, and there is enough space
5832 * on all devices, so we can resize.
5833 * We need to make sure resync covers any new space.
5834 * If the array is shrinking we should possibly wait until
5835 * any io in the removed space completes, but it hardly seems
5839 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5840 newsize
= raid5_size(mddev
, sectors
, mddev
->raid_disks
);
5841 if (mddev
->external_size
&&
5842 mddev
->array_sectors
> newsize
)
5844 if (mddev
->bitmap
) {
5845 int ret
= bitmap_resize(mddev
->bitmap
, sectors
, 0, 0);
5849 md_set_array_sectors(mddev
, newsize
);
5850 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5851 revalidate_disk(mddev
->gendisk
);
5852 if (sectors
> mddev
->dev_sectors
&&
5853 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5854 mddev
->recovery_cp
= mddev
->dev_sectors
;
5855 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5857 mddev
->dev_sectors
= sectors
;
5858 mddev
->resync_max_sectors
= sectors
;
5862 static int check_stripe_cache(struct mddev
*mddev
)
5864 /* Can only proceed if there are plenty of stripe_heads.
5865 * We need a minimum of one full stripe,, and for sensible progress
5866 * it is best to have about 4 times that.
5867 * If we require 4 times, then the default 256 4K stripe_heads will
5868 * allow for chunk sizes up to 256K, which is probably OK.
5869 * If the chunk size is greater, user-space should request more
5870 * stripe_heads first.
5872 struct r5conf
*conf
= mddev
->private;
5873 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5874 > conf
->max_nr_stripes
||
5875 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5876 > conf
->max_nr_stripes
) {
5877 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5879 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5886 static int check_reshape(struct mddev
*mddev
)
5888 struct r5conf
*conf
= mddev
->private;
5890 if (mddev
->delta_disks
== 0 &&
5891 mddev
->new_layout
== mddev
->layout
&&
5892 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5893 return 0; /* nothing to do */
5894 if (has_failed(conf
))
5896 if (mddev
->delta_disks
< 0) {
5897 /* We might be able to shrink, but the devices must
5898 * be made bigger first.
5899 * For raid6, 4 is the minimum size.
5900 * Otherwise 2 is the minimum
5903 if (mddev
->level
== 6)
5905 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5909 if (!check_stripe_cache(mddev
))
5912 return resize_stripes(conf
, (conf
->previous_raid_disks
5913 + mddev
->delta_disks
));
5916 static int raid5_start_reshape(struct mddev
*mddev
)
5918 struct r5conf
*conf
= mddev
->private;
5919 struct md_rdev
*rdev
;
5921 unsigned long flags
;
5923 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5926 if (!check_stripe_cache(mddev
))
5929 if (has_failed(conf
))
5932 rdev_for_each(rdev
, mddev
) {
5933 if (!test_bit(In_sync
, &rdev
->flags
)
5934 && !test_bit(Faulty
, &rdev
->flags
))
5938 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5939 /* Not enough devices even to make a degraded array
5944 /* Refuse to reduce size of the array. Any reductions in
5945 * array size must be through explicit setting of array_size
5948 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5949 < mddev
->array_sectors
) {
5950 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5951 "before number of disks\n", mdname(mddev
));
5955 atomic_set(&conf
->reshape_stripes
, 0);
5956 spin_lock_irq(&conf
->device_lock
);
5957 conf
->previous_raid_disks
= conf
->raid_disks
;
5958 conf
->raid_disks
+= mddev
->delta_disks
;
5959 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5960 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5961 conf
->prev_algo
= conf
->algorithm
;
5962 conf
->algorithm
= mddev
->new_layout
;
5964 /* Code that selects data_offset needs to see the generation update
5965 * if reshape_progress has been set - so a memory barrier needed.
5968 if (mddev
->reshape_backwards
)
5969 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5971 conf
->reshape_progress
= 0;
5972 conf
->reshape_safe
= conf
->reshape_progress
;
5973 spin_unlock_irq(&conf
->device_lock
);
5975 /* Add some new drives, as many as will fit.
5976 * We know there are enough to make the newly sized array work.
5977 * Don't add devices if we are reducing the number of
5978 * devices in the array. This is because it is not possible
5979 * to correctly record the "partially reconstructed" state of
5980 * such devices during the reshape and confusion could result.
5982 if (mddev
->delta_disks
>= 0) {
5983 rdev_for_each(rdev
, mddev
)
5984 if (rdev
->raid_disk
< 0 &&
5985 !test_bit(Faulty
, &rdev
->flags
)) {
5986 if (raid5_add_disk(mddev
, rdev
) == 0) {
5988 >= conf
->previous_raid_disks
)
5989 set_bit(In_sync
, &rdev
->flags
);
5991 rdev
->recovery_offset
= 0;
5993 if (sysfs_link_rdev(mddev
, rdev
))
5994 /* Failure here is OK */;
5996 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5997 && !test_bit(Faulty
, &rdev
->flags
)) {
5998 /* This is a spare that was manually added */
5999 set_bit(In_sync
, &rdev
->flags
);
6002 /* When a reshape changes the number of devices,
6003 * ->degraded is measured against the larger of the
6004 * pre and post number of devices.
6006 spin_lock_irqsave(&conf
->device_lock
, flags
);
6007 mddev
->degraded
= calc_degraded(conf
);
6008 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
6010 mddev
->raid_disks
= conf
->raid_disks
;
6011 mddev
->reshape_position
= conf
->reshape_progress
;
6012 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6014 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
6015 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
6016 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
6017 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
6018 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
6020 if (!mddev
->sync_thread
) {
6021 mddev
->recovery
= 0;
6022 spin_lock_irq(&conf
->device_lock
);
6023 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
6024 rdev_for_each(rdev
, mddev
)
6025 rdev
->new_data_offset
= rdev
->data_offset
;
6027 conf
->reshape_progress
= MaxSector
;
6028 mddev
->reshape_position
= MaxSector
;
6029 spin_unlock_irq(&conf
->device_lock
);
6032 conf
->reshape_checkpoint
= jiffies
;
6033 md_wakeup_thread(mddev
->sync_thread
);
6034 md_new_event(mddev
);
6038 /* This is called from the reshape thread and should make any
6039 * changes needed in 'conf'
6041 static void end_reshape(struct r5conf
*conf
)
6044 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
6045 struct md_rdev
*rdev
;
6047 spin_lock_irq(&conf
->device_lock
);
6048 conf
->previous_raid_disks
= conf
->raid_disks
;
6049 rdev_for_each(rdev
, conf
->mddev
)
6050 rdev
->data_offset
= rdev
->new_data_offset
;
6052 conf
->reshape_progress
= MaxSector
;
6053 spin_unlock_irq(&conf
->device_lock
);
6054 wake_up(&conf
->wait_for_overlap
);
6056 /* read-ahead size must cover two whole stripes, which is
6057 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
6059 if (conf
->mddev
->queue
) {
6060 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
6061 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
6063 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
6064 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
6069 /* This is called from the raid5d thread with mddev_lock held.
6070 * It makes config changes to the device.
6072 static void raid5_finish_reshape(struct mddev
*mddev
)
6074 struct r5conf
*conf
= mddev
->private;
6076 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
6078 if (mddev
->delta_disks
> 0) {
6079 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
6080 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
6081 revalidate_disk(mddev
->gendisk
);
6084 spin_lock_irq(&conf
->device_lock
);
6085 mddev
->degraded
= calc_degraded(conf
);
6086 spin_unlock_irq(&conf
->device_lock
);
6087 for (d
= conf
->raid_disks
;
6088 d
< conf
->raid_disks
- mddev
->delta_disks
;
6090 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
6092 clear_bit(In_sync
, &rdev
->flags
);
6093 rdev
= conf
->disks
[d
].replacement
;
6095 clear_bit(In_sync
, &rdev
->flags
);
6098 mddev
->layout
= conf
->algorithm
;
6099 mddev
->chunk_sectors
= conf
->chunk_sectors
;
6100 mddev
->reshape_position
= MaxSector
;
6101 mddev
->delta_disks
= 0;
6102 mddev
->reshape_backwards
= 0;
6106 static void raid5_quiesce(struct mddev
*mddev
, int state
)
6108 struct r5conf
*conf
= mddev
->private;
6111 case 2: /* resume for a suspend */
6112 wake_up(&conf
->wait_for_overlap
);
6115 case 1: /* stop all writes */
6116 spin_lock_irq(&conf
->device_lock
);
6117 /* '2' tells resync/reshape to pause so that all
6118 * active stripes can drain
6121 wait_event_lock_irq(conf
->wait_for_stripe
,
6122 atomic_read(&conf
->active_stripes
) == 0 &&
6123 atomic_read(&conf
->active_aligned_reads
) == 0,
6126 spin_unlock_irq(&conf
->device_lock
);
6127 /* allow reshape to continue */
6128 wake_up(&conf
->wait_for_overlap
);
6131 case 0: /* re-enable writes */
6132 spin_lock_irq(&conf
->device_lock
);
6134 wake_up(&conf
->wait_for_stripe
);
6135 wake_up(&conf
->wait_for_overlap
);
6136 spin_unlock_irq(&conf
->device_lock
);
6142 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
6144 struct r0conf
*raid0_conf
= mddev
->private;
6147 /* for raid0 takeover only one zone is supported */
6148 if (raid0_conf
->nr_strip_zones
> 1) {
6149 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
6151 return ERR_PTR(-EINVAL
);
6154 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
6155 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
6156 mddev
->dev_sectors
= sectors
;
6157 mddev
->new_level
= level
;
6158 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6159 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
6160 mddev
->raid_disks
+= 1;
6161 mddev
->delta_disks
= 1;
6162 /* make sure it will be not marked as dirty */
6163 mddev
->recovery_cp
= MaxSector
;
6165 return setup_conf(mddev
);
6169 static void *raid5_takeover_raid1(struct mddev
*mddev
)
6173 if (mddev
->raid_disks
!= 2 ||
6174 mddev
->degraded
> 1)
6175 return ERR_PTR(-EINVAL
);
6177 /* Should check if there are write-behind devices? */
6179 chunksect
= 64*2; /* 64K by default */
6181 /* The array must be an exact multiple of chunksize */
6182 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
6185 if ((chunksect
<<9) < STRIPE_SIZE
)
6186 /* array size does not allow a suitable chunk size */
6187 return ERR_PTR(-EINVAL
);
6189 mddev
->new_level
= 5;
6190 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6191 mddev
->new_chunk_sectors
= chunksect
;
6193 return setup_conf(mddev
);
6196 static void *raid5_takeover_raid6(struct mddev
*mddev
)
6200 switch (mddev
->layout
) {
6201 case ALGORITHM_LEFT_ASYMMETRIC_6
:
6202 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
6204 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
6205 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
6207 case ALGORITHM_LEFT_SYMMETRIC_6
:
6208 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
6210 case ALGORITHM_RIGHT_SYMMETRIC_6
:
6211 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
6213 case ALGORITHM_PARITY_0_6
:
6214 new_layout
= ALGORITHM_PARITY_0
;
6216 case ALGORITHM_PARITY_N
:
6217 new_layout
= ALGORITHM_PARITY_N
;
6220 return ERR_PTR(-EINVAL
);
6222 mddev
->new_level
= 5;
6223 mddev
->new_layout
= new_layout
;
6224 mddev
->delta_disks
= -1;
6225 mddev
->raid_disks
-= 1;
6226 return setup_conf(mddev
);
6230 static int raid5_check_reshape(struct mddev
*mddev
)
6232 /* For a 2-drive array, the layout and chunk size can be changed
6233 * immediately as not restriping is needed.
6234 * For larger arrays we record the new value - after validation
6235 * to be used by a reshape pass.
6237 struct r5conf
*conf
= mddev
->private;
6238 int new_chunk
= mddev
->new_chunk_sectors
;
6240 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
6242 if (new_chunk
> 0) {
6243 if (!is_power_of_2(new_chunk
))
6245 if (new_chunk
< (PAGE_SIZE
>>9))
6247 if (mddev
->array_sectors
& (new_chunk
-1))
6248 /* not factor of array size */
6252 /* They look valid */
6254 if (mddev
->raid_disks
== 2) {
6255 /* can make the change immediately */
6256 if (mddev
->new_layout
>= 0) {
6257 conf
->algorithm
= mddev
->new_layout
;
6258 mddev
->layout
= mddev
->new_layout
;
6260 if (new_chunk
> 0) {
6261 conf
->chunk_sectors
= new_chunk
;
6262 mddev
->chunk_sectors
= new_chunk
;
6264 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
6265 md_wakeup_thread(mddev
->thread
);
6267 return check_reshape(mddev
);
6270 static int raid6_check_reshape(struct mddev
*mddev
)
6272 int new_chunk
= mddev
->new_chunk_sectors
;
6274 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
6276 if (new_chunk
> 0) {
6277 if (!is_power_of_2(new_chunk
))
6279 if (new_chunk
< (PAGE_SIZE
>> 9))
6281 if (mddev
->array_sectors
& (new_chunk
-1))
6282 /* not factor of array size */
6286 /* They look valid */
6287 return check_reshape(mddev
);
6290 static void *raid5_takeover(struct mddev
*mddev
)
6292 /* raid5 can take over:
6293 * raid0 - if there is only one strip zone - make it a raid4 layout
6294 * raid1 - if there are two drives. We need to know the chunk size
6295 * raid4 - trivial - just use a raid4 layout.
6296 * raid6 - Providing it is a *_6 layout
6298 if (mddev
->level
== 0)
6299 return raid45_takeover_raid0(mddev
, 5);
6300 if (mddev
->level
== 1)
6301 return raid5_takeover_raid1(mddev
);
6302 if (mddev
->level
== 4) {
6303 mddev
->new_layout
= ALGORITHM_PARITY_N
;
6304 mddev
->new_level
= 5;
6305 return setup_conf(mddev
);
6307 if (mddev
->level
== 6)
6308 return raid5_takeover_raid6(mddev
);
6310 return ERR_PTR(-EINVAL
);
6313 static void *raid4_takeover(struct mddev
*mddev
)
6315 /* raid4 can take over:
6316 * raid0 - if there is only one strip zone
6317 * raid5 - if layout is right
6319 if (mddev
->level
== 0)
6320 return raid45_takeover_raid0(mddev
, 4);
6321 if (mddev
->level
== 5 &&
6322 mddev
->layout
== ALGORITHM_PARITY_N
) {
6323 mddev
->new_layout
= 0;
6324 mddev
->new_level
= 4;
6325 return setup_conf(mddev
);
6327 return ERR_PTR(-EINVAL
);
6330 static struct md_personality raid5_personality
;
6332 static void *raid6_takeover(struct mddev
*mddev
)
6334 /* Currently can only take over a raid5. We map the
6335 * personality to an equivalent raid6 personality
6336 * with the Q block at the end.
6340 if (mddev
->pers
!= &raid5_personality
)
6341 return ERR_PTR(-EINVAL
);
6342 if (mddev
->degraded
> 1)
6343 return ERR_PTR(-EINVAL
);
6344 if (mddev
->raid_disks
> 253)
6345 return ERR_PTR(-EINVAL
);
6346 if (mddev
->raid_disks
< 3)
6347 return ERR_PTR(-EINVAL
);
6349 switch (mddev
->layout
) {
6350 case ALGORITHM_LEFT_ASYMMETRIC
:
6351 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
6353 case ALGORITHM_RIGHT_ASYMMETRIC
:
6354 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
6356 case ALGORITHM_LEFT_SYMMETRIC
:
6357 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
6359 case ALGORITHM_RIGHT_SYMMETRIC
:
6360 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
6362 case ALGORITHM_PARITY_0
:
6363 new_layout
= ALGORITHM_PARITY_0_6
;
6365 case ALGORITHM_PARITY_N
:
6366 new_layout
= ALGORITHM_PARITY_N
;
6369 return ERR_PTR(-EINVAL
);
6371 mddev
->new_level
= 6;
6372 mddev
->new_layout
= new_layout
;
6373 mddev
->delta_disks
= 1;
6374 mddev
->raid_disks
+= 1;
6375 return setup_conf(mddev
);
6379 static struct md_personality raid6_personality
=
6383 .owner
= THIS_MODULE
,
6384 .make_request
= make_request
,
6388 .error_handler
= error
,
6389 .hot_add_disk
= raid5_add_disk
,
6390 .hot_remove_disk
= raid5_remove_disk
,
6391 .spare_active
= raid5_spare_active
,
6392 .sync_request
= sync_request
,
6393 .resize
= raid5_resize
,
6395 .check_reshape
= raid6_check_reshape
,
6396 .start_reshape
= raid5_start_reshape
,
6397 .finish_reshape
= raid5_finish_reshape
,
6398 .quiesce
= raid5_quiesce
,
6399 .takeover
= raid6_takeover
,
6401 static struct md_personality raid5_personality
=
6405 .owner
= THIS_MODULE
,
6406 .make_request
= make_request
,
6410 .error_handler
= error
,
6411 .hot_add_disk
= raid5_add_disk
,
6412 .hot_remove_disk
= raid5_remove_disk
,
6413 .spare_active
= raid5_spare_active
,
6414 .sync_request
= sync_request
,
6415 .resize
= raid5_resize
,
6417 .check_reshape
= raid5_check_reshape
,
6418 .start_reshape
= raid5_start_reshape
,
6419 .finish_reshape
= raid5_finish_reshape
,
6420 .quiesce
= raid5_quiesce
,
6421 .takeover
= raid5_takeover
,
6424 static struct md_personality raid4_personality
=
6428 .owner
= THIS_MODULE
,
6429 .make_request
= make_request
,
6433 .error_handler
= error
,
6434 .hot_add_disk
= raid5_add_disk
,
6435 .hot_remove_disk
= raid5_remove_disk
,
6436 .spare_active
= raid5_spare_active
,
6437 .sync_request
= sync_request
,
6438 .resize
= raid5_resize
,
6440 .check_reshape
= raid5_check_reshape
,
6441 .start_reshape
= raid5_start_reshape
,
6442 .finish_reshape
= raid5_finish_reshape
,
6443 .quiesce
= raid5_quiesce
,
6444 .takeover
= raid4_takeover
,
6447 static int __init
raid5_init(void)
6449 register_md_personality(&raid6_personality
);
6450 register_md_personality(&raid5_personality
);
6451 register_md_personality(&raid4_personality
);
6455 static void raid5_exit(void)
6457 unregister_md_personality(&raid6_personality
);
6458 unregister_md_personality(&raid5_personality
);
6459 unregister_md_personality(&raid4_personality
);
6462 module_init(raid5_init
);
6463 module_exit(raid5_exit
);
6464 MODULE_LICENSE("GPL");
6465 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
6466 MODULE_ALIAS("md-personality-4"); /* RAID5 */
6467 MODULE_ALIAS("md-raid5");
6468 MODULE_ALIAS("md-raid4");
6469 MODULE_ALIAS("md-level-5");
6470 MODULE_ALIAS("md-level-4");
6471 MODULE_ALIAS("md-personality-8"); /* RAID6 */
6472 MODULE_ALIAS("md-raid6");
6473 MODULE_ALIAS("md-level-6");
6475 /* This used to be two separate modules, they were: */
6476 MODULE_ALIAS("raid5");
6477 MODULE_ALIAS("raid6");