2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * The sequencing for updating the bitmap reliably is a little
25 * subtle (and I got it wrong the first time) so it deserves some
28 * We group bitmap updates into batches. Each batch has a number.
29 * We may write out several batches at once, but that isn't very important.
30 * conf->seq_write is the number of the last batch successfully written.
31 * conf->seq_flush is the number of the last batch that was closed to
33 * When we discover that we will need to write to any block in a stripe
34 * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
35 * the number of the batch it will be in. This is seq_flush+1.
36 * When we are ready to do a write, if that batch hasn't been written yet,
37 * we plug the array and queue the stripe for later.
38 * When an unplug happens, we increment bm_flush, thus closing the current
40 * When we notice that bm_flush > bm_write, we write out all pending updates
41 * to the bitmap, and advance bm_write to where bm_flush was.
42 * This may occasionally write a bit out twice, but is sure never to
46 #include <linux/blkdev.h>
47 #include <linux/kthread.h>
48 #include <linux/raid/pq.h>
49 #include <linux/async_tx.h>
50 #include <linux/module.h>
51 #include <linux/async.h>
52 #include <linux/seq_file.h>
53 #include <linux/cpu.h>
54 #include <linux/slab.h>
55 #include <linux/ratelimit.h>
65 #define NR_STRIPES 256
66 #define STRIPE_SIZE PAGE_SIZE
67 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
68 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
69 #define IO_THRESHOLD 1
70 #define BYPASS_THRESHOLD 1
71 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
72 #define HASH_MASK (NR_HASH - 1)
74 static inline struct hlist_head
*stripe_hash(struct r5conf
*conf
, sector_t sect
)
76 int hash
= (sect
>> STRIPE_SHIFT
) & HASH_MASK
;
77 return &conf
->stripe_hashtbl
[hash
];
80 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
81 * order without overlap. There may be several bio's per stripe+device, and
82 * a bio could span several devices.
83 * When walking this list for a particular stripe+device, we must never proceed
84 * beyond a bio that extends past this device, as the next bio might no longer
86 * This function is used to determine the 'next' bio in the list, given the sector
87 * of the current stripe+device
89 static inline struct bio
*r5_next_bio(struct bio
*bio
, sector_t sector
)
91 int sectors
= bio
->bi_size
>> 9;
92 if (bio
->bi_sector
+ sectors
< sector
+ STRIPE_SECTORS
)
99 * We maintain a biased count of active stripes in the bottom 16 bits of
100 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
102 static inline int raid5_bi_phys_segments(struct bio
*bio
)
104 return bio
->bi_phys_segments
& 0xffff;
107 static inline int raid5_bi_hw_segments(struct bio
*bio
)
109 return (bio
->bi_phys_segments
>> 16) & 0xffff;
112 static inline int raid5_dec_bi_phys_segments(struct bio
*bio
)
114 --bio
->bi_phys_segments
;
115 return raid5_bi_phys_segments(bio
);
118 static inline int raid5_dec_bi_hw_segments(struct bio
*bio
)
120 unsigned short val
= raid5_bi_hw_segments(bio
);
123 bio
->bi_phys_segments
= (val
<< 16) | raid5_bi_phys_segments(bio
);
127 static inline void raid5_set_bi_hw_segments(struct bio
*bio
, unsigned int cnt
)
129 bio
->bi_phys_segments
= raid5_bi_phys_segments(bio
) | (cnt
<< 16);
132 /* Find first data disk in a raid6 stripe */
133 static inline int raid6_d0(struct stripe_head
*sh
)
136 /* ddf always start from first device */
138 /* md starts just after Q block */
139 if (sh
->qd_idx
== sh
->disks
- 1)
142 return sh
->qd_idx
+ 1;
144 static inline int raid6_next_disk(int disk
, int raid_disks
)
147 return (disk
< raid_disks
) ? disk
: 0;
150 /* When walking through the disks in a raid5, starting at raid6_d0,
151 * We need to map each disk to a 'slot', where the data disks are slot
152 * 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
153 * is raid_disks-1. This help does that mapping.
155 static int raid6_idx_to_slot(int idx
, struct stripe_head
*sh
,
156 int *count
, int syndrome_disks
)
162 if (idx
== sh
->pd_idx
)
163 return syndrome_disks
;
164 if (idx
== sh
->qd_idx
)
165 return syndrome_disks
+ 1;
171 static void return_io(struct bio
*return_bi
)
173 struct bio
*bi
= return_bi
;
176 return_bi
= bi
->bi_next
;
184 static void print_raid5_conf (struct r5conf
*conf
);
186 static int stripe_operations_active(struct stripe_head
*sh
)
188 return sh
->check_state
|| sh
->reconstruct_state
||
189 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
190 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
193 static void __release_stripe(struct r5conf
*conf
, struct stripe_head
*sh
)
195 if (atomic_dec_and_test(&sh
->count
)) {
196 BUG_ON(!list_empty(&sh
->lru
));
197 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
198 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
199 if (test_bit(STRIPE_DELAYED
, &sh
->state
))
200 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
201 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
202 sh
->bm_seq
- conf
->seq_write
> 0)
203 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
205 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
206 list_add_tail(&sh
->lru
, &conf
->handle_list
);
208 md_wakeup_thread(conf
->mddev
->thread
);
210 BUG_ON(stripe_operations_active(sh
));
211 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
212 atomic_dec(&conf
->preread_active_stripes
);
213 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
214 md_wakeup_thread(conf
->mddev
->thread
);
216 atomic_dec(&conf
->active_stripes
);
217 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
218 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
219 wake_up(&conf
->wait_for_stripe
);
220 if (conf
->retry_read_aligned
)
221 md_wakeup_thread(conf
->mddev
->thread
);
227 static void release_stripe(struct stripe_head
*sh
)
229 struct r5conf
*conf
= sh
->raid_conf
;
232 spin_lock_irqsave(&conf
->device_lock
, flags
);
233 __release_stripe(conf
, sh
);
234 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
237 static inline void remove_hash(struct stripe_head
*sh
)
239 pr_debug("remove_hash(), stripe %llu\n",
240 (unsigned long long)sh
->sector
);
242 hlist_del_init(&sh
->hash
);
245 static inline void insert_hash(struct r5conf
*conf
, struct stripe_head
*sh
)
247 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
249 pr_debug("insert_hash(), stripe %llu\n",
250 (unsigned long long)sh
->sector
);
252 hlist_add_head(&sh
->hash
, hp
);
256 /* find an idle stripe, make sure it is unhashed, and return it. */
257 static struct stripe_head
*get_free_stripe(struct r5conf
*conf
)
259 struct stripe_head
*sh
= NULL
;
260 struct list_head
*first
;
262 if (list_empty(&conf
->inactive_list
))
264 first
= conf
->inactive_list
.next
;
265 sh
= list_entry(first
, struct stripe_head
, lru
);
266 list_del_init(first
);
268 atomic_inc(&conf
->active_stripes
);
273 static void shrink_buffers(struct stripe_head
*sh
)
277 int num
= sh
->raid_conf
->pool_size
;
279 for (i
= 0; i
< num
; i
++) {
283 sh
->dev
[i
].page
= NULL
;
288 static int grow_buffers(struct stripe_head
*sh
)
291 int num
= sh
->raid_conf
->pool_size
;
293 for (i
= 0; i
< num
; i
++) {
296 if (!(page
= alloc_page(GFP_KERNEL
))) {
299 sh
->dev
[i
].page
= page
;
304 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
);
305 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
306 struct stripe_head
*sh
);
308 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
310 struct r5conf
*conf
= sh
->raid_conf
;
313 BUG_ON(atomic_read(&sh
->count
) != 0);
314 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
315 BUG_ON(stripe_operations_active(sh
));
317 pr_debug("init_stripe called, stripe %llu\n",
318 (unsigned long long)sh
->sector
);
322 sh
->generation
= conf
->generation
- previous
;
323 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
325 stripe_set_idx(sector
, conf
, previous
, sh
);
329 for (i
= sh
->disks
; i
--; ) {
330 struct r5dev
*dev
= &sh
->dev
[i
];
332 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
333 test_bit(R5_LOCKED
, &dev
->flags
)) {
334 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
335 (unsigned long long)sh
->sector
, i
, dev
->toread
,
336 dev
->read
, dev
->towrite
, dev
->written
,
337 test_bit(R5_LOCKED
, &dev
->flags
));
341 raid5_build_block(sh
, i
, previous
);
343 insert_hash(conf
, sh
);
346 static struct stripe_head
*__find_stripe(struct r5conf
*conf
, sector_t sector
,
349 struct stripe_head
*sh
;
350 struct hlist_node
*hn
;
352 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
353 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
354 if (sh
->sector
== sector
&& sh
->generation
== generation
)
356 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
361 * Need to check if array has failed when deciding whether to:
363 * - remove non-faulty devices
366 * This determination is simple when no reshape is happening.
367 * However if there is a reshape, we need to carefully check
368 * both the before and after sections.
369 * This is because some failed devices may only affect one
370 * of the two sections, and some non-in_sync devices may
371 * be insync in the section most affected by failed devices.
373 static int calc_degraded(struct r5conf
*conf
)
375 int degraded
, degraded2
;
380 for (i
= 0; i
< conf
->previous_raid_disks
; i
++) {
381 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
382 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
384 else if (test_bit(In_sync
, &rdev
->flags
))
387 /* not in-sync or faulty.
388 * If the reshape increases the number of devices,
389 * this is being recovered by the reshape, so
390 * this 'previous' section is not in_sync.
391 * If the number of devices is being reduced however,
392 * the device can only be part of the array if
393 * we are reverting a reshape, so this section will
396 if (conf
->raid_disks
>= conf
->previous_raid_disks
)
400 if (conf
->raid_disks
== conf
->previous_raid_disks
)
404 for (i
= 0; i
< conf
->raid_disks
; i
++) {
405 struct md_rdev
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
406 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
408 else if (test_bit(In_sync
, &rdev
->flags
))
411 /* not in-sync or faulty.
412 * If reshape increases the number of devices, this
413 * section has already been recovered, else it
414 * almost certainly hasn't.
416 if (conf
->raid_disks
<= conf
->previous_raid_disks
)
420 if (degraded2
> degraded
)
425 static int has_failed(struct r5conf
*conf
)
429 if (conf
->mddev
->reshape_position
== MaxSector
)
430 return conf
->mddev
->degraded
> conf
->max_degraded
;
432 degraded
= calc_degraded(conf
);
433 if (degraded
> conf
->max_degraded
)
438 static struct stripe_head
*
439 get_active_stripe(struct r5conf
*conf
, sector_t sector
,
440 int previous
, int noblock
, int noquiesce
)
442 struct stripe_head
*sh
;
444 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
446 spin_lock_irq(&conf
->device_lock
);
449 wait_event_lock_irq(conf
->wait_for_stripe
,
450 conf
->quiesce
== 0 || noquiesce
,
451 conf
->device_lock
, /* nothing */);
452 sh
= __find_stripe(conf
, sector
, conf
->generation
- previous
);
454 if (!conf
->inactive_blocked
)
455 sh
= get_free_stripe(conf
);
456 if (noblock
&& sh
== NULL
)
459 conf
->inactive_blocked
= 1;
460 wait_event_lock_irq(conf
->wait_for_stripe
,
461 !list_empty(&conf
->inactive_list
) &&
462 (atomic_read(&conf
->active_stripes
)
463 < (conf
->max_nr_stripes
*3/4)
464 || !conf
->inactive_blocked
),
467 conf
->inactive_blocked
= 0;
469 init_stripe(sh
, sector
, previous
);
471 if (atomic_read(&sh
->count
)) {
472 BUG_ON(!list_empty(&sh
->lru
)
473 && !test_bit(STRIPE_EXPANDING
, &sh
->state
));
475 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
476 atomic_inc(&conf
->active_stripes
);
477 if (list_empty(&sh
->lru
) &&
478 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
480 list_del_init(&sh
->lru
);
483 } while (sh
== NULL
);
486 atomic_inc(&sh
->count
);
488 spin_unlock_irq(&conf
->device_lock
);
493 raid5_end_read_request(struct bio
*bi
, int error
);
495 raid5_end_write_request(struct bio
*bi
, int error
);
497 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
499 struct r5conf
*conf
= sh
->raid_conf
;
500 int i
, disks
= sh
->disks
;
504 for (i
= disks
; i
--; ) {
507 struct md_rdev
*rdev
;
508 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
)) {
509 if (test_and_clear_bit(R5_WantFUA
, &sh
->dev
[i
].flags
))
513 } else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
518 bi
= &sh
->dev
[i
].req
;
522 bi
->bi_end_io
= raid5_end_write_request
;
524 bi
->bi_end_io
= raid5_end_read_request
;
528 test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
529 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
531 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
532 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
535 atomic_inc(&rdev
->nr_pending
);
538 /* We have already checked bad blocks for reads. Now
539 * need to check for writes.
541 while ((rw
& WRITE
) && rdev
&&
542 test_bit(WriteErrorSeen
, &rdev
->flags
)) {
545 int bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
546 &first_bad
, &bad_sectors
);
551 set_bit(BlockedBadBlocks
, &rdev
->flags
);
552 if (!conf
->mddev
->external
&&
553 conf
->mddev
->flags
) {
554 /* It is very unlikely, but we might
555 * still need to write out the
556 * bad block log - better give it
558 md_check_recovery(conf
->mddev
);
560 md_wait_for_blocked_rdev(rdev
, conf
->mddev
);
562 /* Acknowledged bad block - skip the write */
563 rdev_dec_pending(rdev
, conf
->mddev
);
569 if (s
->syncing
|| s
->expanding
|| s
->expanded
)
570 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
572 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
574 bi
->bi_bdev
= rdev
->bdev
;
575 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
576 __func__
, (unsigned long long)sh
->sector
,
578 atomic_inc(&sh
->count
);
579 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
580 bi
->bi_flags
= 1 << BIO_UPTODATE
;
582 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
583 bi
->bi_io_vec
[0].bv_offset
= 0;
584 bi
->bi_size
= STRIPE_SIZE
;
586 generic_make_request(bi
);
589 set_bit(STRIPE_DEGRADED
, &sh
->state
);
590 pr_debug("skip op %ld on disc %d for sector %llu\n",
591 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
592 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
593 set_bit(STRIPE_HANDLE
, &sh
->state
);
598 static struct dma_async_tx_descriptor
*
599 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
600 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
603 struct page
*bio_page
;
606 struct async_submit_ctl submit
;
607 enum async_tx_flags flags
= 0;
609 if (bio
->bi_sector
>= sector
)
610 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
612 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
615 flags
|= ASYNC_TX_FENCE
;
616 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
618 bio_for_each_segment(bvl
, bio
, i
) {
619 int len
= bvl
->bv_len
;
623 if (page_offset
< 0) {
624 b_offset
= -page_offset
;
625 page_offset
+= b_offset
;
629 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
630 clen
= STRIPE_SIZE
- page_offset
;
635 b_offset
+= bvl
->bv_offset
;
636 bio_page
= bvl
->bv_page
;
638 tx
= async_memcpy(page
, bio_page
, page_offset
,
639 b_offset
, clen
, &submit
);
641 tx
= async_memcpy(bio_page
, page
, b_offset
,
642 page_offset
, clen
, &submit
);
644 /* chain the operations */
645 submit
.depend_tx
= tx
;
647 if (clen
< len
) /* hit end of page */
655 static void ops_complete_biofill(void *stripe_head_ref
)
657 struct stripe_head
*sh
= stripe_head_ref
;
658 struct bio
*return_bi
= NULL
;
659 struct r5conf
*conf
= sh
->raid_conf
;
662 pr_debug("%s: stripe %llu\n", __func__
,
663 (unsigned long long)sh
->sector
);
665 /* clear completed biofills */
666 spin_lock_irq(&conf
->device_lock
);
667 for (i
= sh
->disks
; i
--; ) {
668 struct r5dev
*dev
= &sh
->dev
[i
];
670 /* acknowledge completion of a biofill operation */
671 /* and check if we need to reply to a read request,
672 * new R5_Wantfill requests are held off until
673 * !STRIPE_BIOFILL_RUN
675 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
676 struct bio
*rbi
, *rbi2
;
681 while (rbi
&& rbi
->bi_sector
<
682 dev
->sector
+ STRIPE_SECTORS
) {
683 rbi2
= r5_next_bio(rbi
, dev
->sector
);
684 if (!raid5_dec_bi_phys_segments(rbi
)) {
685 rbi
->bi_next
= return_bi
;
692 spin_unlock_irq(&conf
->device_lock
);
693 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
695 return_io(return_bi
);
697 set_bit(STRIPE_HANDLE
, &sh
->state
);
701 static void ops_run_biofill(struct stripe_head
*sh
)
703 struct dma_async_tx_descriptor
*tx
= NULL
;
704 struct r5conf
*conf
= sh
->raid_conf
;
705 struct async_submit_ctl submit
;
708 pr_debug("%s: stripe %llu\n", __func__
,
709 (unsigned long long)sh
->sector
);
711 for (i
= sh
->disks
; i
--; ) {
712 struct r5dev
*dev
= &sh
->dev
[i
];
713 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
715 spin_lock_irq(&conf
->device_lock
);
716 dev
->read
= rbi
= dev
->toread
;
718 spin_unlock_irq(&conf
->device_lock
);
719 while (rbi
&& rbi
->bi_sector
<
720 dev
->sector
+ STRIPE_SECTORS
) {
721 tx
= async_copy_data(0, rbi
, dev
->page
,
723 rbi
= r5_next_bio(rbi
, dev
->sector
);
728 atomic_inc(&sh
->count
);
729 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
730 async_trigger_callback(&submit
);
733 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
740 tgt
= &sh
->dev
[target
];
741 set_bit(R5_UPTODATE
, &tgt
->flags
);
742 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
743 clear_bit(R5_Wantcompute
, &tgt
->flags
);
746 static void ops_complete_compute(void *stripe_head_ref
)
748 struct stripe_head
*sh
= stripe_head_ref
;
750 pr_debug("%s: stripe %llu\n", __func__
,
751 (unsigned long long)sh
->sector
);
753 /* mark the computed target(s) as uptodate */
754 mark_target_uptodate(sh
, sh
->ops
.target
);
755 mark_target_uptodate(sh
, sh
->ops
.target2
);
757 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
758 if (sh
->check_state
== check_state_compute_run
)
759 sh
->check_state
= check_state_compute_result
;
760 set_bit(STRIPE_HANDLE
, &sh
->state
);
764 /* return a pointer to the address conversion region of the scribble buffer */
765 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
766 struct raid5_percpu
*percpu
)
768 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
771 static struct dma_async_tx_descriptor
*
772 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
774 int disks
= sh
->disks
;
775 struct page
**xor_srcs
= percpu
->scribble
;
776 int target
= sh
->ops
.target
;
777 struct r5dev
*tgt
= &sh
->dev
[target
];
778 struct page
*xor_dest
= tgt
->page
;
780 struct dma_async_tx_descriptor
*tx
;
781 struct async_submit_ctl submit
;
784 pr_debug("%s: stripe %llu block: %d\n",
785 __func__
, (unsigned long long)sh
->sector
, target
);
786 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
788 for (i
= disks
; i
--; )
790 xor_srcs
[count
++] = sh
->dev
[i
].page
;
792 atomic_inc(&sh
->count
);
794 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
795 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
796 if (unlikely(count
== 1))
797 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
799 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
804 /* set_syndrome_sources - populate source buffers for gen_syndrome
805 * @srcs - (struct page *) array of size sh->disks
806 * @sh - stripe_head to parse
808 * Populates srcs in proper layout order for the stripe and returns the
809 * 'count' of sources to be used in a call to async_gen_syndrome. The P
810 * destination buffer is recorded in srcs[count] and the Q destination
811 * is recorded in srcs[count+1]].
813 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
815 int disks
= sh
->disks
;
816 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
817 int d0_idx
= raid6_d0(sh
);
821 for (i
= 0; i
< disks
; i
++)
827 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
829 srcs
[slot
] = sh
->dev
[i
].page
;
830 i
= raid6_next_disk(i
, disks
);
831 } while (i
!= d0_idx
);
833 return syndrome_disks
;
836 static struct dma_async_tx_descriptor
*
837 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
839 int disks
= sh
->disks
;
840 struct page
**blocks
= percpu
->scribble
;
842 int qd_idx
= sh
->qd_idx
;
843 struct dma_async_tx_descriptor
*tx
;
844 struct async_submit_ctl submit
;
850 if (sh
->ops
.target
< 0)
851 target
= sh
->ops
.target2
;
852 else if (sh
->ops
.target2
< 0)
853 target
= sh
->ops
.target
;
855 /* we should only have one valid target */
858 pr_debug("%s: stripe %llu block: %d\n",
859 __func__
, (unsigned long long)sh
->sector
, target
);
861 tgt
= &sh
->dev
[target
];
862 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
865 atomic_inc(&sh
->count
);
867 if (target
== qd_idx
) {
868 count
= set_syndrome_sources(blocks
, sh
);
869 blocks
[count
] = NULL
; /* regenerating p is not necessary */
870 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
871 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
872 ops_complete_compute
, sh
,
873 to_addr_conv(sh
, percpu
));
874 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
876 /* Compute any data- or p-drive using XOR */
878 for (i
= disks
; i
-- ; ) {
879 if (i
== target
|| i
== qd_idx
)
881 blocks
[count
++] = sh
->dev
[i
].page
;
884 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
885 NULL
, ops_complete_compute
, sh
,
886 to_addr_conv(sh
, percpu
));
887 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
893 static struct dma_async_tx_descriptor
*
894 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
896 int i
, count
, disks
= sh
->disks
;
897 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
898 int d0_idx
= raid6_d0(sh
);
899 int faila
= -1, failb
= -1;
900 int target
= sh
->ops
.target
;
901 int target2
= sh
->ops
.target2
;
902 struct r5dev
*tgt
= &sh
->dev
[target
];
903 struct r5dev
*tgt2
= &sh
->dev
[target2
];
904 struct dma_async_tx_descriptor
*tx
;
905 struct page
**blocks
= percpu
->scribble
;
906 struct async_submit_ctl submit
;
908 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
909 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
910 BUG_ON(target
< 0 || target2
< 0);
911 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
912 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
914 /* we need to open-code set_syndrome_sources to handle the
915 * slot number conversion for 'faila' and 'failb'
917 for (i
= 0; i
< disks
; i
++)
922 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
924 blocks
[slot
] = sh
->dev
[i
].page
;
930 i
= raid6_next_disk(i
, disks
);
931 } while (i
!= d0_idx
);
933 BUG_ON(faila
== failb
);
936 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
937 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
939 atomic_inc(&sh
->count
);
941 if (failb
== syndrome_disks
+1) {
942 /* Q disk is one of the missing disks */
943 if (faila
== syndrome_disks
) {
944 /* Missing P+Q, just recompute */
945 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
946 ops_complete_compute
, sh
,
947 to_addr_conv(sh
, percpu
));
948 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
949 STRIPE_SIZE
, &submit
);
953 int qd_idx
= sh
->qd_idx
;
955 /* Missing D+Q: recompute D from P, then recompute Q */
956 if (target
== qd_idx
)
957 data_target
= target2
;
959 data_target
= target
;
962 for (i
= disks
; i
-- ; ) {
963 if (i
== data_target
|| i
== qd_idx
)
965 blocks
[count
++] = sh
->dev
[i
].page
;
967 dest
= sh
->dev
[data_target
].page
;
968 init_async_submit(&submit
,
969 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
971 to_addr_conv(sh
, percpu
));
972 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
975 count
= set_syndrome_sources(blocks
, sh
);
976 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
977 ops_complete_compute
, sh
,
978 to_addr_conv(sh
, percpu
));
979 return async_gen_syndrome(blocks
, 0, count
+2,
980 STRIPE_SIZE
, &submit
);
983 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
984 ops_complete_compute
, sh
,
985 to_addr_conv(sh
, percpu
));
986 if (failb
== syndrome_disks
) {
987 /* We're missing D+P. */
988 return async_raid6_datap_recov(syndrome_disks
+2,
992 /* We're missing D+D. */
993 return async_raid6_2data_recov(syndrome_disks
+2,
994 STRIPE_SIZE
, faila
, failb
,
1001 static void ops_complete_prexor(void *stripe_head_ref
)
1003 struct stripe_head
*sh
= stripe_head_ref
;
1005 pr_debug("%s: stripe %llu\n", __func__
,
1006 (unsigned long long)sh
->sector
);
1009 static struct dma_async_tx_descriptor
*
1010 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1011 struct dma_async_tx_descriptor
*tx
)
1013 int disks
= sh
->disks
;
1014 struct page
**xor_srcs
= percpu
->scribble
;
1015 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1016 struct async_submit_ctl submit
;
1018 /* existing parity data subtracted */
1019 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1021 pr_debug("%s: stripe %llu\n", __func__
,
1022 (unsigned long long)sh
->sector
);
1024 for (i
= disks
; i
--; ) {
1025 struct r5dev
*dev
= &sh
->dev
[i
];
1026 /* Only process blocks that are known to be uptodate */
1027 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1028 xor_srcs
[count
++] = dev
->page
;
1031 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1032 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1033 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1038 static struct dma_async_tx_descriptor
*
1039 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1041 int disks
= sh
->disks
;
1044 pr_debug("%s: stripe %llu\n", __func__
,
1045 (unsigned long long)sh
->sector
);
1047 for (i
= disks
; i
--; ) {
1048 struct r5dev
*dev
= &sh
->dev
[i
];
1051 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1054 spin_lock_irq(&sh
->raid_conf
->device_lock
);
1055 chosen
= dev
->towrite
;
1056 dev
->towrite
= NULL
;
1057 BUG_ON(dev
->written
);
1058 wbi
= dev
->written
= chosen
;
1059 spin_unlock_irq(&sh
->raid_conf
->device_lock
);
1061 while (wbi
&& wbi
->bi_sector
<
1062 dev
->sector
+ STRIPE_SECTORS
) {
1063 if (wbi
->bi_rw
& REQ_FUA
)
1064 set_bit(R5_WantFUA
, &dev
->flags
);
1065 tx
= async_copy_data(1, wbi
, dev
->page
,
1067 wbi
= r5_next_bio(wbi
, dev
->sector
);
1075 static void ops_complete_reconstruct(void *stripe_head_ref
)
1077 struct stripe_head
*sh
= stripe_head_ref
;
1078 int disks
= sh
->disks
;
1079 int pd_idx
= sh
->pd_idx
;
1080 int qd_idx
= sh
->qd_idx
;
1084 pr_debug("%s: stripe %llu\n", __func__
,
1085 (unsigned long long)sh
->sector
);
1087 for (i
= disks
; i
--; )
1088 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1090 for (i
= disks
; i
--; ) {
1091 struct r5dev
*dev
= &sh
->dev
[i
];
1093 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1094 set_bit(R5_UPTODATE
, &dev
->flags
);
1096 set_bit(R5_WantFUA
, &dev
->flags
);
1100 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1101 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1102 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1103 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1105 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1106 sh
->reconstruct_state
= reconstruct_state_result
;
1109 set_bit(STRIPE_HANDLE
, &sh
->state
);
1114 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1115 struct dma_async_tx_descriptor
*tx
)
1117 int disks
= sh
->disks
;
1118 struct page
**xor_srcs
= percpu
->scribble
;
1119 struct async_submit_ctl submit
;
1120 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1121 struct page
*xor_dest
;
1123 unsigned long flags
;
1125 pr_debug("%s: stripe %llu\n", __func__
,
1126 (unsigned long long)sh
->sector
);
1128 /* check if prexor is active which means only process blocks
1129 * that are part of a read-modify-write (written)
1131 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1133 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1134 for (i
= disks
; i
--; ) {
1135 struct r5dev
*dev
= &sh
->dev
[i
];
1137 xor_srcs
[count
++] = dev
->page
;
1140 xor_dest
= sh
->dev
[pd_idx
].page
;
1141 for (i
= disks
; i
--; ) {
1142 struct r5dev
*dev
= &sh
->dev
[i
];
1144 xor_srcs
[count
++] = dev
->page
;
1148 /* 1/ if we prexor'd then the dest is reused as a source
1149 * 2/ if we did not prexor then we are redoing the parity
1150 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1151 * for the synchronous xor case
1153 flags
= ASYNC_TX_ACK
|
1154 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1156 atomic_inc(&sh
->count
);
1158 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1159 to_addr_conv(sh
, percpu
));
1160 if (unlikely(count
== 1))
1161 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1163 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1167 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1168 struct dma_async_tx_descriptor
*tx
)
1170 struct async_submit_ctl submit
;
1171 struct page
**blocks
= percpu
->scribble
;
1174 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1176 count
= set_syndrome_sources(blocks
, sh
);
1178 atomic_inc(&sh
->count
);
1180 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1181 sh
, to_addr_conv(sh
, percpu
));
1182 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1185 static void ops_complete_check(void *stripe_head_ref
)
1187 struct stripe_head
*sh
= stripe_head_ref
;
1189 pr_debug("%s: stripe %llu\n", __func__
,
1190 (unsigned long long)sh
->sector
);
1192 sh
->check_state
= check_state_check_result
;
1193 set_bit(STRIPE_HANDLE
, &sh
->state
);
1197 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1199 int disks
= sh
->disks
;
1200 int pd_idx
= sh
->pd_idx
;
1201 int qd_idx
= sh
->qd_idx
;
1202 struct page
*xor_dest
;
1203 struct page
**xor_srcs
= percpu
->scribble
;
1204 struct dma_async_tx_descriptor
*tx
;
1205 struct async_submit_ctl submit
;
1209 pr_debug("%s: stripe %llu\n", __func__
,
1210 (unsigned long long)sh
->sector
);
1213 xor_dest
= sh
->dev
[pd_idx
].page
;
1214 xor_srcs
[count
++] = xor_dest
;
1215 for (i
= disks
; i
--; ) {
1216 if (i
== pd_idx
|| i
== qd_idx
)
1218 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1221 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1222 to_addr_conv(sh
, percpu
));
1223 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1224 &sh
->ops
.zero_sum_result
, &submit
);
1226 atomic_inc(&sh
->count
);
1227 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1228 tx
= async_trigger_callback(&submit
);
1231 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1233 struct page
**srcs
= percpu
->scribble
;
1234 struct async_submit_ctl submit
;
1237 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1238 (unsigned long long)sh
->sector
, checkp
);
1240 count
= set_syndrome_sources(srcs
, sh
);
1244 atomic_inc(&sh
->count
);
1245 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1246 sh
, to_addr_conv(sh
, percpu
));
1247 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1248 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1251 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1253 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1254 struct dma_async_tx_descriptor
*tx
= NULL
;
1255 struct r5conf
*conf
= sh
->raid_conf
;
1256 int level
= conf
->level
;
1257 struct raid5_percpu
*percpu
;
1261 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1262 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1263 ops_run_biofill(sh
);
1267 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1269 tx
= ops_run_compute5(sh
, percpu
);
1271 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1272 tx
= ops_run_compute6_1(sh
, percpu
);
1274 tx
= ops_run_compute6_2(sh
, percpu
);
1276 /* terminate the chain if reconstruct is not set to be run */
1277 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1281 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1282 tx
= ops_run_prexor(sh
, percpu
, tx
);
1284 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1285 tx
= ops_run_biodrain(sh
, tx
);
1289 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1291 ops_run_reconstruct5(sh
, percpu
, tx
);
1293 ops_run_reconstruct6(sh
, percpu
, tx
);
1296 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1297 if (sh
->check_state
== check_state_run
)
1298 ops_run_check_p(sh
, percpu
);
1299 else if (sh
->check_state
== check_state_run_q
)
1300 ops_run_check_pq(sh
, percpu
, 0);
1301 else if (sh
->check_state
== check_state_run_pq
)
1302 ops_run_check_pq(sh
, percpu
, 1);
1308 for (i
= disks
; i
--; ) {
1309 struct r5dev
*dev
= &sh
->dev
[i
];
1310 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1311 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1316 #ifdef CONFIG_MULTICORE_RAID456
1317 static void async_run_ops(void *param
, async_cookie_t cookie
)
1319 struct stripe_head
*sh
= param
;
1320 unsigned long ops_request
= sh
->ops
.request
;
1322 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1323 wake_up(&sh
->ops
.wait_for_ops
);
1325 __raid_run_ops(sh
, ops_request
);
1329 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1331 /* since handle_stripe can be called outside of raid5d context
1332 * we need to ensure sh->ops.request is de-staged before another
1335 wait_event(sh
->ops
.wait_for_ops
,
1336 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1337 sh
->ops
.request
= ops_request
;
1339 atomic_inc(&sh
->count
);
1340 async_schedule(async_run_ops
, sh
);
1343 #define raid_run_ops __raid_run_ops
1346 static int grow_one_stripe(struct r5conf
*conf
)
1348 struct stripe_head
*sh
;
1349 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1353 sh
->raid_conf
= conf
;
1354 #ifdef CONFIG_MULTICORE_RAID456
1355 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1358 if (grow_buffers(sh
)) {
1360 kmem_cache_free(conf
->slab_cache
, sh
);
1363 /* we just created an active stripe so... */
1364 atomic_set(&sh
->count
, 1);
1365 atomic_inc(&conf
->active_stripes
);
1366 INIT_LIST_HEAD(&sh
->lru
);
1371 static int grow_stripes(struct r5conf
*conf
, int num
)
1373 struct kmem_cache
*sc
;
1374 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1376 if (conf
->mddev
->gendisk
)
1377 sprintf(conf
->cache_name
[0],
1378 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1380 sprintf(conf
->cache_name
[0],
1381 "raid%d-%p", conf
->level
, conf
->mddev
);
1382 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1384 conf
->active_name
= 0;
1385 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1386 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1390 conf
->slab_cache
= sc
;
1391 conf
->pool_size
= devs
;
1393 if (!grow_one_stripe(conf
))
1399 * scribble_len - return the required size of the scribble region
1400 * @num - total number of disks in the array
1402 * The size must be enough to contain:
1403 * 1/ a struct page pointer for each device in the array +2
1404 * 2/ room to convert each entry in (1) to its corresponding dma
1405 * (dma_map_page()) or page (page_address()) address.
1407 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1408 * calculate over all devices (not just the data blocks), using zeros in place
1409 * of the P and Q blocks.
1411 static size_t scribble_len(int num
)
1415 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1420 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1422 /* Make all the stripes able to hold 'newsize' devices.
1423 * New slots in each stripe get 'page' set to a new page.
1425 * This happens in stages:
1426 * 1/ create a new kmem_cache and allocate the required number of
1428 * 2/ gather all the old stripe_heads and tranfer the pages across
1429 * to the new stripe_heads. This will have the side effect of
1430 * freezing the array as once all stripe_heads have been collected,
1431 * no IO will be possible. Old stripe heads are freed once their
1432 * pages have been transferred over, and the old kmem_cache is
1433 * freed when all stripes are done.
1434 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1435 * we simple return a failre status - no need to clean anything up.
1436 * 4/ allocate new pages for the new slots in the new stripe_heads.
1437 * If this fails, we don't bother trying the shrink the
1438 * stripe_heads down again, we just leave them as they are.
1439 * As each stripe_head is processed the new one is released into
1442 * Once step2 is started, we cannot afford to wait for a write,
1443 * so we use GFP_NOIO allocations.
1445 struct stripe_head
*osh
, *nsh
;
1446 LIST_HEAD(newstripes
);
1447 struct disk_info
*ndisks
;
1450 struct kmem_cache
*sc
;
1453 if (newsize
<= conf
->pool_size
)
1454 return 0; /* never bother to shrink */
1456 err
= md_allow_write(conf
->mddev
);
1461 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1462 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1467 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1468 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1472 nsh
->raid_conf
= conf
;
1473 #ifdef CONFIG_MULTICORE_RAID456
1474 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1477 list_add(&nsh
->lru
, &newstripes
);
1480 /* didn't get enough, give up */
1481 while (!list_empty(&newstripes
)) {
1482 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1483 list_del(&nsh
->lru
);
1484 kmem_cache_free(sc
, nsh
);
1486 kmem_cache_destroy(sc
);
1489 /* Step 2 - Must use GFP_NOIO now.
1490 * OK, we have enough stripes, start collecting inactive
1491 * stripes and copying them over
1493 list_for_each_entry(nsh
, &newstripes
, lru
) {
1494 spin_lock_irq(&conf
->device_lock
);
1495 wait_event_lock_irq(conf
->wait_for_stripe
,
1496 !list_empty(&conf
->inactive_list
),
1499 osh
= get_free_stripe(conf
);
1500 spin_unlock_irq(&conf
->device_lock
);
1501 atomic_set(&nsh
->count
, 1);
1502 for(i
=0; i
<conf
->pool_size
; i
++)
1503 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1504 for( ; i
<newsize
; i
++)
1505 nsh
->dev
[i
].page
= NULL
;
1506 kmem_cache_free(conf
->slab_cache
, osh
);
1508 kmem_cache_destroy(conf
->slab_cache
);
1511 * At this point, we are holding all the stripes so the array
1512 * is completely stalled, so now is a good time to resize
1513 * conf->disks and the scribble region
1515 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1517 for (i
=0; i
<conf
->raid_disks
; i
++)
1518 ndisks
[i
] = conf
->disks
[i
];
1520 conf
->disks
= ndisks
;
1525 conf
->scribble_len
= scribble_len(newsize
);
1526 for_each_present_cpu(cpu
) {
1527 struct raid5_percpu
*percpu
;
1530 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1531 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1534 kfree(percpu
->scribble
);
1535 percpu
->scribble
= scribble
;
1543 /* Step 4, return new stripes to service */
1544 while(!list_empty(&newstripes
)) {
1545 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1546 list_del_init(&nsh
->lru
);
1548 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1549 if (nsh
->dev
[i
].page
== NULL
) {
1550 struct page
*p
= alloc_page(GFP_NOIO
);
1551 nsh
->dev
[i
].page
= p
;
1555 release_stripe(nsh
);
1557 /* critical section pass, GFP_NOIO no longer needed */
1559 conf
->slab_cache
= sc
;
1560 conf
->active_name
= 1-conf
->active_name
;
1561 conf
->pool_size
= newsize
;
1565 static int drop_one_stripe(struct r5conf
*conf
)
1567 struct stripe_head
*sh
;
1569 spin_lock_irq(&conf
->device_lock
);
1570 sh
= get_free_stripe(conf
);
1571 spin_unlock_irq(&conf
->device_lock
);
1574 BUG_ON(atomic_read(&sh
->count
));
1576 kmem_cache_free(conf
->slab_cache
, sh
);
1577 atomic_dec(&conf
->active_stripes
);
1581 static void shrink_stripes(struct r5conf
*conf
)
1583 while (drop_one_stripe(conf
))
1586 if (conf
->slab_cache
)
1587 kmem_cache_destroy(conf
->slab_cache
);
1588 conf
->slab_cache
= NULL
;
1591 static void raid5_end_read_request(struct bio
* bi
, int error
)
1593 struct stripe_head
*sh
= bi
->bi_private
;
1594 struct r5conf
*conf
= sh
->raid_conf
;
1595 int disks
= sh
->disks
, i
;
1596 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1597 char b
[BDEVNAME_SIZE
];
1598 struct md_rdev
*rdev
;
1601 for (i
=0 ; i
<disks
; i
++)
1602 if (bi
== &sh
->dev
[i
].req
)
1605 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1606 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1612 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1613 rdev
= conf
->disks
[i
].replacement
;
1615 rdev
= conf
->disks
[i
].rdev
;
1618 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1619 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1620 /* Note that this cannot happen on a
1621 * replacement device. We just fail those on
1626 "md/raid:%s: read error corrected"
1627 " (%lu sectors at %llu on %s)\n",
1628 mdname(conf
->mddev
), STRIPE_SECTORS
,
1629 (unsigned long long)(sh
->sector
1630 + rdev
->data_offset
),
1631 bdevname(rdev
->bdev
, b
));
1632 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1633 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1634 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1636 if (atomic_read(&rdev
->read_errors
))
1637 atomic_set(&rdev
->read_errors
, 0);
1639 const char *bdn
= bdevname(rdev
->bdev
, b
);
1642 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1643 atomic_inc(&rdev
->read_errors
);
1644 if (test_bit(R5_ReadRepl
, &sh
->dev
[i
].flags
))
1647 "md/raid:%s: read error on replacement device "
1648 "(sector %llu on %s).\n",
1649 mdname(conf
->mddev
),
1650 (unsigned long long)(sh
->sector
1651 + rdev
->data_offset
),
1653 else if (conf
->mddev
->degraded
>= conf
->max_degraded
)
1656 "md/raid:%s: read error not correctable "
1657 "(sector %llu on %s).\n",
1658 mdname(conf
->mddev
),
1659 (unsigned long long)(sh
->sector
1660 + rdev
->data_offset
),
1662 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1666 "md/raid:%s: read error NOT corrected!! "
1667 "(sector %llu on %s).\n",
1668 mdname(conf
->mddev
),
1669 (unsigned long long)(sh
->sector
1670 + rdev
->data_offset
),
1672 else if (atomic_read(&rdev
->read_errors
)
1673 > conf
->max_nr_stripes
)
1675 "md/raid:%s: Too many read errors, failing device %s.\n",
1676 mdname(conf
->mddev
), bdn
);
1680 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1682 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1683 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1684 md_error(conf
->mddev
, rdev
);
1687 rdev_dec_pending(rdev
, conf
->mddev
);
1688 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1689 set_bit(STRIPE_HANDLE
, &sh
->state
);
1693 static void raid5_end_write_request(struct bio
*bi
, int error
)
1695 struct stripe_head
*sh
= bi
->bi_private
;
1696 struct r5conf
*conf
= sh
->raid_conf
;
1697 int disks
= sh
->disks
, i
;
1698 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1702 for (i
=0 ; i
<disks
; i
++)
1703 if (bi
== &sh
->dev
[i
].req
)
1706 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1707 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1715 set_bit(WriteErrorSeen
, &conf
->disks
[i
].rdev
->flags
);
1716 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1717 } else if (is_badblock(conf
->disks
[i
].rdev
, sh
->sector
, STRIPE_SECTORS
,
1718 &first_bad
, &bad_sectors
))
1719 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1721 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1723 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1724 set_bit(STRIPE_HANDLE
, &sh
->state
);
1729 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1731 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1733 struct r5dev
*dev
= &sh
->dev
[i
];
1735 bio_init(&dev
->req
);
1736 dev
->req
.bi_io_vec
= &dev
->vec
;
1738 dev
->req
.bi_max_vecs
++;
1739 dev
->req
.bi_private
= sh
;
1740 dev
->vec
.bv_page
= dev
->page
;
1743 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1746 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1748 char b
[BDEVNAME_SIZE
];
1749 struct r5conf
*conf
= mddev
->private;
1750 unsigned long flags
;
1751 pr_debug("raid456: error called\n");
1753 spin_lock_irqsave(&conf
->device_lock
, flags
);
1754 clear_bit(In_sync
, &rdev
->flags
);
1755 mddev
->degraded
= calc_degraded(conf
);
1756 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1757 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1759 set_bit(Blocked
, &rdev
->flags
);
1760 set_bit(Faulty
, &rdev
->flags
);
1761 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1763 "md/raid:%s: Disk failure on %s, disabling device.\n"
1764 "md/raid:%s: Operation continuing on %d devices.\n",
1766 bdevname(rdev
->bdev
, b
),
1768 conf
->raid_disks
- mddev
->degraded
);
1772 * Input: a 'big' sector number,
1773 * Output: index of the data and parity disk, and the sector # in them.
1775 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1776 int previous
, int *dd_idx
,
1777 struct stripe_head
*sh
)
1779 sector_t stripe
, stripe2
;
1780 sector_t chunk_number
;
1781 unsigned int chunk_offset
;
1784 sector_t new_sector
;
1785 int algorithm
= previous
? conf
->prev_algo
1787 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1788 : conf
->chunk_sectors
;
1789 int raid_disks
= previous
? conf
->previous_raid_disks
1791 int data_disks
= raid_disks
- conf
->max_degraded
;
1793 /* First compute the information on this sector */
1796 * Compute the chunk number and the sector offset inside the chunk
1798 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1799 chunk_number
= r_sector
;
1802 * Compute the stripe number
1804 stripe
= chunk_number
;
1805 *dd_idx
= sector_div(stripe
, data_disks
);
1808 * Select the parity disk based on the user selected algorithm.
1810 pd_idx
= qd_idx
= -1;
1811 switch(conf
->level
) {
1813 pd_idx
= data_disks
;
1816 switch (algorithm
) {
1817 case ALGORITHM_LEFT_ASYMMETRIC
:
1818 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1819 if (*dd_idx
>= pd_idx
)
1822 case ALGORITHM_RIGHT_ASYMMETRIC
:
1823 pd_idx
= sector_div(stripe2
, raid_disks
);
1824 if (*dd_idx
>= pd_idx
)
1827 case ALGORITHM_LEFT_SYMMETRIC
:
1828 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1829 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1831 case ALGORITHM_RIGHT_SYMMETRIC
:
1832 pd_idx
= sector_div(stripe2
, raid_disks
);
1833 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1835 case ALGORITHM_PARITY_0
:
1839 case ALGORITHM_PARITY_N
:
1840 pd_idx
= data_disks
;
1848 switch (algorithm
) {
1849 case ALGORITHM_LEFT_ASYMMETRIC
:
1850 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1851 qd_idx
= pd_idx
+ 1;
1852 if (pd_idx
== raid_disks
-1) {
1853 (*dd_idx
)++; /* Q D D D P */
1855 } else if (*dd_idx
>= pd_idx
)
1856 (*dd_idx
) += 2; /* D D P Q D */
1858 case ALGORITHM_RIGHT_ASYMMETRIC
:
1859 pd_idx
= sector_div(stripe2
, raid_disks
);
1860 qd_idx
= pd_idx
+ 1;
1861 if (pd_idx
== raid_disks
-1) {
1862 (*dd_idx
)++; /* Q D D D P */
1864 } else if (*dd_idx
>= pd_idx
)
1865 (*dd_idx
) += 2; /* D D P Q D */
1867 case ALGORITHM_LEFT_SYMMETRIC
:
1868 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1869 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1870 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1872 case ALGORITHM_RIGHT_SYMMETRIC
:
1873 pd_idx
= sector_div(stripe2
, raid_disks
);
1874 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1875 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1878 case ALGORITHM_PARITY_0
:
1883 case ALGORITHM_PARITY_N
:
1884 pd_idx
= data_disks
;
1885 qd_idx
= data_disks
+ 1;
1888 case ALGORITHM_ROTATING_ZERO_RESTART
:
1889 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1890 * of blocks for computing Q is different.
1892 pd_idx
= sector_div(stripe2
, raid_disks
);
1893 qd_idx
= pd_idx
+ 1;
1894 if (pd_idx
== raid_disks
-1) {
1895 (*dd_idx
)++; /* Q D D D P */
1897 } else if (*dd_idx
>= pd_idx
)
1898 (*dd_idx
) += 2; /* D D P Q D */
1902 case ALGORITHM_ROTATING_N_RESTART
:
1903 /* Same a left_asymmetric, by first stripe is
1904 * D D D P Q rather than
1908 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1909 qd_idx
= pd_idx
+ 1;
1910 if (pd_idx
== raid_disks
-1) {
1911 (*dd_idx
)++; /* Q D D D P */
1913 } else if (*dd_idx
>= pd_idx
)
1914 (*dd_idx
) += 2; /* D D P Q D */
1918 case ALGORITHM_ROTATING_N_CONTINUE
:
1919 /* Same as left_symmetric but Q is before P */
1920 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1921 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
1922 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1926 case ALGORITHM_LEFT_ASYMMETRIC_6
:
1927 /* RAID5 left_asymmetric, with Q on last device */
1928 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1929 if (*dd_idx
>= pd_idx
)
1931 qd_idx
= raid_disks
- 1;
1934 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
1935 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1936 if (*dd_idx
>= pd_idx
)
1938 qd_idx
= raid_disks
- 1;
1941 case ALGORITHM_LEFT_SYMMETRIC_6
:
1942 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1943 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1944 qd_idx
= raid_disks
- 1;
1947 case ALGORITHM_RIGHT_SYMMETRIC_6
:
1948 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1949 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1950 qd_idx
= raid_disks
- 1;
1953 case ALGORITHM_PARITY_0_6
:
1956 qd_idx
= raid_disks
- 1;
1966 sh
->pd_idx
= pd_idx
;
1967 sh
->qd_idx
= qd_idx
;
1968 sh
->ddf_layout
= ddf_layout
;
1971 * Finally, compute the new sector number
1973 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
1978 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
1980 struct r5conf
*conf
= sh
->raid_conf
;
1981 int raid_disks
= sh
->disks
;
1982 int data_disks
= raid_disks
- conf
->max_degraded
;
1983 sector_t new_sector
= sh
->sector
, check
;
1984 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1985 : conf
->chunk_sectors
;
1986 int algorithm
= previous
? conf
->prev_algo
1990 sector_t chunk_number
;
1991 int dummy1
, dd_idx
= i
;
1993 struct stripe_head sh2
;
1996 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
1997 stripe
= new_sector
;
1999 if (i
== sh
->pd_idx
)
2001 switch(conf
->level
) {
2004 switch (algorithm
) {
2005 case ALGORITHM_LEFT_ASYMMETRIC
:
2006 case ALGORITHM_RIGHT_ASYMMETRIC
:
2010 case ALGORITHM_LEFT_SYMMETRIC
:
2011 case ALGORITHM_RIGHT_SYMMETRIC
:
2014 i
-= (sh
->pd_idx
+ 1);
2016 case ALGORITHM_PARITY_0
:
2019 case ALGORITHM_PARITY_N
:
2026 if (i
== sh
->qd_idx
)
2027 return 0; /* It is the Q disk */
2028 switch (algorithm
) {
2029 case ALGORITHM_LEFT_ASYMMETRIC
:
2030 case ALGORITHM_RIGHT_ASYMMETRIC
:
2031 case ALGORITHM_ROTATING_ZERO_RESTART
:
2032 case ALGORITHM_ROTATING_N_RESTART
:
2033 if (sh
->pd_idx
== raid_disks
-1)
2034 i
--; /* Q D D D P */
2035 else if (i
> sh
->pd_idx
)
2036 i
-= 2; /* D D P Q D */
2038 case ALGORITHM_LEFT_SYMMETRIC
:
2039 case ALGORITHM_RIGHT_SYMMETRIC
:
2040 if (sh
->pd_idx
== raid_disks
-1)
2041 i
--; /* Q D D D P */
2046 i
-= (sh
->pd_idx
+ 2);
2049 case ALGORITHM_PARITY_0
:
2052 case ALGORITHM_PARITY_N
:
2054 case ALGORITHM_ROTATING_N_CONTINUE
:
2055 /* Like left_symmetric, but P is before Q */
2056 if (sh
->pd_idx
== 0)
2057 i
--; /* P D D D Q */
2062 i
-= (sh
->pd_idx
+ 1);
2065 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2066 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2070 case ALGORITHM_LEFT_SYMMETRIC_6
:
2071 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2073 i
+= data_disks
+ 1;
2074 i
-= (sh
->pd_idx
+ 1);
2076 case ALGORITHM_PARITY_0_6
:
2085 chunk_number
= stripe
* data_disks
+ i
;
2086 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2088 check
= raid5_compute_sector(conf
, r_sector
,
2089 previous
, &dummy1
, &sh2
);
2090 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2091 || sh2
.qd_idx
!= sh
->qd_idx
) {
2092 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2093 mdname(conf
->mddev
));
2101 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2102 int rcw
, int expand
)
2104 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2105 struct r5conf
*conf
= sh
->raid_conf
;
2106 int level
= conf
->level
;
2109 /* if we are not expanding this is a proper write request, and
2110 * there will be bios with new data to be drained into the
2114 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2115 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2117 sh
->reconstruct_state
= reconstruct_state_run
;
2119 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2121 for (i
= disks
; i
--; ) {
2122 struct r5dev
*dev
= &sh
->dev
[i
];
2125 set_bit(R5_LOCKED
, &dev
->flags
);
2126 set_bit(R5_Wantdrain
, &dev
->flags
);
2128 clear_bit(R5_UPTODATE
, &dev
->flags
);
2132 if (s
->locked
+ conf
->max_degraded
== disks
)
2133 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2134 atomic_inc(&conf
->pending_full_writes
);
2137 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2138 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2140 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2141 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2142 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2143 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2145 for (i
= disks
; i
--; ) {
2146 struct r5dev
*dev
= &sh
->dev
[i
];
2151 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2152 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2153 set_bit(R5_Wantdrain
, &dev
->flags
);
2154 set_bit(R5_LOCKED
, &dev
->flags
);
2155 clear_bit(R5_UPTODATE
, &dev
->flags
);
2161 /* keep the parity disk(s) locked while asynchronous operations
2164 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2165 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2169 int qd_idx
= sh
->qd_idx
;
2170 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2172 set_bit(R5_LOCKED
, &dev
->flags
);
2173 clear_bit(R5_UPTODATE
, &dev
->flags
);
2177 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2178 __func__
, (unsigned long long)sh
->sector
,
2179 s
->locked
, s
->ops_request
);
2183 * Each stripe/dev can have one or more bion attached.
2184 * toread/towrite point to the first in a chain.
2185 * The bi_next chain must be in order.
2187 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2190 struct r5conf
*conf
= sh
->raid_conf
;
2193 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2194 (unsigned long long)bi
->bi_sector
,
2195 (unsigned long long)sh
->sector
);
2198 spin_lock_irq(&conf
->device_lock
);
2200 bip
= &sh
->dev
[dd_idx
].towrite
;
2201 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
2204 bip
= &sh
->dev
[dd_idx
].toread
;
2205 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2206 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2208 bip
= & (*bip
)->bi_next
;
2210 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2213 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2217 bi
->bi_phys_segments
++;
2220 /* check if page is covered */
2221 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2222 for (bi
=sh
->dev
[dd_idx
].towrite
;
2223 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2224 bi
&& bi
->bi_sector
<= sector
;
2225 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2226 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2227 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2229 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2230 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2232 spin_unlock_irq(&conf
->device_lock
);
2234 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2235 (unsigned long long)(*bip
)->bi_sector
,
2236 (unsigned long long)sh
->sector
, dd_idx
);
2238 if (conf
->mddev
->bitmap
&& firstwrite
) {
2239 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2241 sh
->bm_seq
= conf
->seq_flush
+1;
2242 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2247 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2248 spin_unlock_irq(&conf
->device_lock
);
2252 static void end_reshape(struct r5conf
*conf
);
2254 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2255 struct stripe_head
*sh
)
2257 int sectors_per_chunk
=
2258 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2260 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2261 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2263 raid5_compute_sector(conf
,
2264 stripe
* (disks
- conf
->max_degraded
)
2265 *sectors_per_chunk
+ chunk_offset
,
2271 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2272 struct stripe_head_state
*s
, int disks
,
2273 struct bio
**return_bi
)
2276 for (i
= disks
; i
--; ) {
2280 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2281 struct md_rdev
*rdev
;
2283 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2284 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2285 atomic_inc(&rdev
->nr_pending
);
2290 if (!rdev_set_badblocks(
2294 md_error(conf
->mddev
, rdev
);
2295 rdev_dec_pending(rdev
, conf
->mddev
);
2298 spin_lock_irq(&conf
->device_lock
);
2299 /* fail all writes first */
2300 bi
= sh
->dev
[i
].towrite
;
2301 sh
->dev
[i
].towrite
= NULL
;
2307 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2308 wake_up(&conf
->wait_for_overlap
);
2310 while (bi
&& bi
->bi_sector
<
2311 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2312 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2313 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2314 if (!raid5_dec_bi_phys_segments(bi
)) {
2315 md_write_end(conf
->mddev
);
2316 bi
->bi_next
= *return_bi
;
2321 /* and fail all 'written' */
2322 bi
= sh
->dev
[i
].written
;
2323 sh
->dev
[i
].written
= NULL
;
2324 if (bi
) bitmap_end
= 1;
2325 while (bi
&& bi
->bi_sector
<
2326 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2327 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2328 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2329 if (!raid5_dec_bi_phys_segments(bi
)) {
2330 md_write_end(conf
->mddev
);
2331 bi
->bi_next
= *return_bi
;
2337 /* fail any reads if this device is non-operational and
2338 * the data has not reached the cache yet.
2340 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2341 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2342 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2343 bi
= sh
->dev
[i
].toread
;
2344 sh
->dev
[i
].toread
= NULL
;
2345 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2346 wake_up(&conf
->wait_for_overlap
);
2347 if (bi
) s
->to_read
--;
2348 while (bi
&& bi
->bi_sector
<
2349 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2350 struct bio
*nextbi
=
2351 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2352 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2353 if (!raid5_dec_bi_phys_segments(bi
)) {
2354 bi
->bi_next
= *return_bi
;
2360 spin_unlock_irq(&conf
->device_lock
);
2362 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2363 STRIPE_SECTORS
, 0, 0);
2364 /* If we were in the middle of a write the parity block might
2365 * still be locked - so just clear all R5_LOCKED flags
2367 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2370 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2371 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2372 md_wakeup_thread(conf
->mddev
->thread
);
2376 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2377 struct stripe_head_state
*s
)
2382 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 0);
2383 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2385 /* There is nothing more to do for sync/check/repair.
2386 * For recover we need to record a bad block on all
2387 * non-sync devices, or abort the recovery
2389 if (!test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
))
2391 /* During recovery devices cannot be removed, so locking and
2392 * refcounting of rdevs is not needed
2394 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2395 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2397 || test_bit(Faulty
, &rdev
->flags
)
2398 || test_bit(In_sync
, &rdev
->flags
))
2400 if (!rdev_set_badblocks(rdev
, sh
->sector
,
2405 conf
->recovery_disabled
= conf
->mddev
->recovery_disabled
;
2406 set_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
);
2410 /* fetch_block - checks the given member device to see if its data needs
2411 * to be read or computed to satisfy a request.
2413 * Returns 1 when no more member devices need to be checked, otherwise returns
2414 * 0 to tell the loop in handle_stripe_fill to continue
2416 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2417 int disk_idx
, int disks
)
2419 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2420 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2421 &sh
->dev
[s
->failed_num
[1]] };
2423 /* is the data in this block needed, and can we get it? */
2424 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2425 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2427 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2428 s
->syncing
|| s
->expanding
||
2429 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2430 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2431 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2432 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2433 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2434 /* we would like to get this block, possibly by computing it,
2435 * otherwise read it if the backing disk is insync
2437 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2438 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2439 if ((s
->uptodate
== disks
- 1) &&
2440 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2441 disk_idx
== s
->failed_num
[1]))) {
2442 /* have disk failed, and we're requested to fetch it;
2445 pr_debug("Computing stripe %llu block %d\n",
2446 (unsigned long long)sh
->sector
, disk_idx
);
2447 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2448 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2449 set_bit(R5_Wantcompute
, &dev
->flags
);
2450 sh
->ops
.target
= disk_idx
;
2451 sh
->ops
.target2
= -1; /* no 2nd target */
2453 /* Careful: from this point on 'uptodate' is in the eye
2454 * of raid_run_ops which services 'compute' operations
2455 * before writes. R5_Wantcompute flags a block that will
2456 * be R5_UPTODATE by the time it is needed for a
2457 * subsequent operation.
2461 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2462 /* Computing 2-failure is *very* expensive; only
2463 * do it if failed >= 2
2466 for (other
= disks
; other
--; ) {
2467 if (other
== disk_idx
)
2469 if (!test_bit(R5_UPTODATE
,
2470 &sh
->dev
[other
].flags
))
2474 pr_debug("Computing stripe %llu blocks %d,%d\n",
2475 (unsigned long long)sh
->sector
,
2477 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2478 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2479 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2480 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2481 sh
->ops
.target
= disk_idx
;
2482 sh
->ops
.target2
= other
;
2486 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2487 set_bit(R5_LOCKED
, &dev
->flags
);
2488 set_bit(R5_Wantread
, &dev
->flags
);
2490 pr_debug("Reading block %d (sync=%d)\n",
2491 disk_idx
, s
->syncing
);
2499 * handle_stripe_fill - read or compute data to satisfy pending requests.
2501 static void handle_stripe_fill(struct stripe_head
*sh
,
2502 struct stripe_head_state
*s
,
2507 /* look for blocks to read/compute, skip this if a compute
2508 * is already in flight, or if the stripe contents are in the
2509 * midst of changing due to a write
2511 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2512 !sh
->reconstruct_state
)
2513 for (i
= disks
; i
--; )
2514 if (fetch_block(sh
, s
, i
, disks
))
2516 set_bit(STRIPE_HANDLE
, &sh
->state
);
2520 /* handle_stripe_clean_event
2521 * any written block on an uptodate or failed drive can be returned.
2522 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2523 * never LOCKED, so we don't need to test 'failed' directly.
2525 static void handle_stripe_clean_event(struct r5conf
*conf
,
2526 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2531 for (i
= disks
; i
--; )
2532 if (sh
->dev
[i
].written
) {
2534 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2535 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2536 /* We can return any write requests */
2537 struct bio
*wbi
, *wbi2
;
2539 pr_debug("Return write for disc %d\n", i
);
2540 spin_lock_irq(&conf
->device_lock
);
2542 dev
->written
= NULL
;
2543 while (wbi
&& wbi
->bi_sector
<
2544 dev
->sector
+ STRIPE_SECTORS
) {
2545 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2546 if (!raid5_dec_bi_phys_segments(wbi
)) {
2547 md_write_end(conf
->mddev
);
2548 wbi
->bi_next
= *return_bi
;
2553 if (dev
->towrite
== NULL
)
2555 spin_unlock_irq(&conf
->device_lock
);
2557 bitmap_endwrite(conf
->mddev
->bitmap
,
2560 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2565 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2566 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2567 md_wakeup_thread(conf
->mddev
->thread
);
2570 static void handle_stripe_dirtying(struct r5conf
*conf
,
2571 struct stripe_head
*sh
,
2572 struct stripe_head_state
*s
,
2575 int rmw
= 0, rcw
= 0, i
;
2576 if (conf
->max_degraded
== 2) {
2577 /* RAID6 requires 'rcw' in current implementation
2578 * Calculate the real rcw later - for now fake it
2579 * look like rcw is cheaper
2582 } else for (i
= disks
; i
--; ) {
2583 /* would I have to read this buffer for read_modify_write */
2584 struct r5dev
*dev
= &sh
->dev
[i
];
2585 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2586 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2587 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2588 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2589 if (test_bit(R5_Insync
, &dev
->flags
))
2592 rmw
+= 2*disks
; /* cannot read it */
2594 /* Would I have to read this buffer for reconstruct_write */
2595 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2596 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2597 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2598 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2599 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2604 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2605 (unsigned long long)sh
->sector
, rmw
, rcw
);
2606 set_bit(STRIPE_HANDLE
, &sh
->state
);
2607 if (rmw
< rcw
&& rmw
> 0)
2608 /* prefer read-modify-write, but need to get some data */
2609 for (i
= disks
; i
--; ) {
2610 struct r5dev
*dev
= &sh
->dev
[i
];
2611 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2612 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2613 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2614 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2615 test_bit(R5_Insync
, &dev
->flags
)) {
2617 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2618 pr_debug("Read_old block "
2619 "%d for r-m-w\n", i
);
2620 set_bit(R5_LOCKED
, &dev
->flags
);
2621 set_bit(R5_Wantread
, &dev
->flags
);
2624 set_bit(STRIPE_DELAYED
, &sh
->state
);
2625 set_bit(STRIPE_HANDLE
, &sh
->state
);
2629 if (rcw
<= rmw
&& rcw
> 0) {
2630 /* want reconstruct write, but need to get some data */
2632 for (i
= disks
; i
--; ) {
2633 struct r5dev
*dev
= &sh
->dev
[i
];
2634 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2635 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2636 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2637 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2638 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2640 if (!test_bit(R5_Insync
, &dev
->flags
))
2641 continue; /* it's a failed drive */
2643 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2644 pr_debug("Read_old block "
2645 "%d for Reconstruct\n", i
);
2646 set_bit(R5_LOCKED
, &dev
->flags
);
2647 set_bit(R5_Wantread
, &dev
->flags
);
2650 set_bit(STRIPE_DELAYED
, &sh
->state
);
2651 set_bit(STRIPE_HANDLE
, &sh
->state
);
2656 /* now if nothing is locked, and if we have enough data,
2657 * we can start a write request
2659 /* since handle_stripe can be called at any time we need to handle the
2660 * case where a compute block operation has been submitted and then a
2661 * subsequent call wants to start a write request. raid_run_ops only
2662 * handles the case where compute block and reconstruct are requested
2663 * simultaneously. If this is not the case then new writes need to be
2664 * held off until the compute completes.
2666 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2667 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2668 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2669 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2672 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2673 struct stripe_head_state
*s
, int disks
)
2675 struct r5dev
*dev
= NULL
;
2677 set_bit(STRIPE_HANDLE
, &sh
->state
);
2679 switch (sh
->check_state
) {
2680 case check_state_idle
:
2681 /* start a new check operation if there are no failures */
2682 if (s
->failed
== 0) {
2683 BUG_ON(s
->uptodate
!= disks
);
2684 sh
->check_state
= check_state_run
;
2685 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2686 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2690 dev
= &sh
->dev
[s
->failed_num
[0]];
2692 case check_state_compute_result
:
2693 sh
->check_state
= check_state_idle
;
2695 dev
= &sh
->dev
[sh
->pd_idx
];
2697 /* check that a write has not made the stripe insync */
2698 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2701 /* either failed parity check, or recovery is happening */
2702 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2703 BUG_ON(s
->uptodate
!= disks
);
2705 set_bit(R5_LOCKED
, &dev
->flags
);
2707 set_bit(R5_Wantwrite
, &dev
->flags
);
2709 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2710 set_bit(STRIPE_INSYNC
, &sh
->state
);
2712 case check_state_run
:
2713 break; /* we will be called again upon completion */
2714 case check_state_check_result
:
2715 sh
->check_state
= check_state_idle
;
2717 /* if a failure occurred during the check operation, leave
2718 * STRIPE_INSYNC not set and let the stripe be handled again
2723 /* handle a successful check operation, if parity is correct
2724 * we are done. Otherwise update the mismatch count and repair
2725 * parity if !MD_RECOVERY_CHECK
2727 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2728 /* parity is correct (on disc,
2729 * not in buffer any more)
2731 set_bit(STRIPE_INSYNC
, &sh
->state
);
2733 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2734 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2735 /* don't try to repair!! */
2736 set_bit(STRIPE_INSYNC
, &sh
->state
);
2738 sh
->check_state
= check_state_compute_run
;
2739 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2740 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2741 set_bit(R5_Wantcompute
,
2742 &sh
->dev
[sh
->pd_idx
].flags
);
2743 sh
->ops
.target
= sh
->pd_idx
;
2744 sh
->ops
.target2
= -1;
2749 case check_state_compute_run
:
2752 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2753 __func__
, sh
->check_state
,
2754 (unsigned long long) sh
->sector
);
2760 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
2761 struct stripe_head_state
*s
,
2764 int pd_idx
= sh
->pd_idx
;
2765 int qd_idx
= sh
->qd_idx
;
2768 set_bit(STRIPE_HANDLE
, &sh
->state
);
2770 BUG_ON(s
->failed
> 2);
2772 /* Want to check and possibly repair P and Q.
2773 * However there could be one 'failed' device, in which
2774 * case we can only check one of them, possibly using the
2775 * other to generate missing data
2778 switch (sh
->check_state
) {
2779 case check_state_idle
:
2780 /* start a new check operation if there are < 2 failures */
2781 if (s
->failed
== s
->q_failed
) {
2782 /* The only possible failed device holds Q, so it
2783 * makes sense to check P (If anything else were failed,
2784 * we would have used P to recreate it).
2786 sh
->check_state
= check_state_run
;
2788 if (!s
->q_failed
&& s
->failed
< 2) {
2789 /* Q is not failed, and we didn't use it to generate
2790 * anything, so it makes sense to check it
2792 if (sh
->check_state
== check_state_run
)
2793 sh
->check_state
= check_state_run_pq
;
2795 sh
->check_state
= check_state_run_q
;
2798 /* discard potentially stale zero_sum_result */
2799 sh
->ops
.zero_sum_result
= 0;
2801 if (sh
->check_state
== check_state_run
) {
2802 /* async_xor_zero_sum destroys the contents of P */
2803 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2806 if (sh
->check_state
>= check_state_run
&&
2807 sh
->check_state
<= check_state_run_pq
) {
2808 /* async_syndrome_zero_sum preserves P and Q, so
2809 * no need to mark them !uptodate here
2811 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2815 /* we have 2-disk failure */
2816 BUG_ON(s
->failed
!= 2);
2818 case check_state_compute_result
:
2819 sh
->check_state
= check_state_idle
;
2821 /* check that a write has not made the stripe insync */
2822 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2825 /* now write out any block on a failed drive,
2826 * or P or Q if they were recomputed
2828 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
2829 if (s
->failed
== 2) {
2830 dev
= &sh
->dev
[s
->failed_num
[1]];
2832 set_bit(R5_LOCKED
, &dev
->flags
);
2833 set_bit(R5_Wantwrite
, &dev
->flags
);
2835 if (s
->failed
>= 1) {
2836 dev
= &sh
->dev
[s
->failed_num
[0]];
2838 set_bit(R5_LOCKED
, &dev
->flags
);
2839 set_bit(R5_Wantwrite
, &dev
->flags
);
2841 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2842 dev
= &sh
->dev
[pd_idx
];
2844 set_bit(R5_LOCKED
, &dev
->flags
);
2845 set_bit(R5_Wantwrite
, &dev
->flags
);
2847 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2848 dev
= &sh
->dev
[qd_idx
];
2850 set_bit(R5_LOCKED
, &dev
->flags
);
2851 set_bit(R5_Wantwrite
, &dev
->flags
);
2853 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2855 set_bit(STRIPE_INSYNC
, &sh
->state
);
2857 case check_state_run
:
2858 case check_state_run_q
:
2859 case check_state_run_pq
:
2860 break; /* we will be called again upon completion */
2861 case check_state_check_result
:
2862 sh
->check_state
= check_state_idle
;
2864 /* handle a successful check operation, if parity is correct
2865 * we are done. Otherwise update the mismatch count and repair
2866 * parity if !MD_RECOVERY_CHECK
2868 if (sh
->ops
.zero_sum_result
== 0) {
2869 /* both parities are correct */
2871 set_bit(STRIPE_INSYNC
, &sh
->state
);
2873 /* in contrast to the raid5 case we can validate
2874 * parity, but still have a failure to write
2877 sh
->check_state
= check_state_compute_result
;
2878 /* Returning at this point means that we may go
2879 * off and bring p and/or q uptodate again so
2880 * we make sure to check zero_sum_result again
2881 * to verify if p or q need writeback
2885 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2886 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2887 /* don't try to repair!! */
2888 set_bit(STRIPE_INSYNC
, &sh
->state
);
2890 int *target
= &sh
->ops
.target
;
2892 sh
->ops
.target
= -1;
2893 sh
->ops
.target2
= -1;
2894 sh
->check_state
= check_state_compute_run
;
2895 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2896 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2897 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2898 set_bit(R5_Wantcompute
,
2899 &sh
->dev
[pd_idx
].flags
);
2901 target
= &sh
->ops
.target2
;
2904 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2905 set_bit(R5_Wantcompute
,
2906 &sh
->dev
[qd_idx
].flags
);
2913 case check_state_compute_run
:
2916 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2917 __func__
, sh
->check_state
,
2918 (unsigned long long) sh
->sector
);
2923 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
2927 /* We have read all the blocks in this stripe and now we need to
2928 * copy some of them into a target stripe for expand.
2930 struct dma_async_tx_descriptor
*tx
= NULL
;
2931 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2932 for (i
= 0; i
< sh
->disks
; i
++)
2933 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
2935 struct stripe_head
*sh2
;
2936 struct async_submit_ctl submit
;
2938 sector_t bn
= compute_blocknr(sh
, i
, 1);
2939 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
2941 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
2943 /* so far only the early blocks of this stripe
2944 * have been requested. When later blocks
2945 * get requested, we will try again
2948 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
2949 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
2950 /* must have already done this block */
2951 release_stripe(sh2
);
2955 /* place all the copies on one channel */
2956 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
2957 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
2958 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
2961 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
2962 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
2963 for (j
= 0; j
< conf
->raid_disks
; j
++)
2964 if (j
!= sh2
->pd_idx
&&
2966 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
2968 if (j
== conf
->raid_disks
) {
2969 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
2970 set_bit(STRIPE_HANDLE
, &sh2
->state
);
2972 release_stripe(sh2
);
2975 /* done submitting copies, wait for them to complete */
2978 dma_wait_for_async_tx(tx
);
2984 * handle_stripe - do things to a stripe.
2986 * We lock the stripe and then examine the state of various bits
2987 * to see what needs to be done.
2989 * return some read request which now have data
2990 * return some write requests which are safely on disc
2991 * schedule a read on some buffers
2992 * schedule a write of some buffers
2993 * return confirmation of parity correctness
2995 * buffers are taken off read_list or write_list, and bh_cache buffers
2996 * get BH_Lock set before the stripe lock is released.
3000 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
3002 struct r5conf
*conf
= sh
->raid_conf
;
3003 int disks
= sh
->disks
;
3007 memset(s
, 0, sizeof(*s
));
3009 s
->syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
3010 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3011 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3012 s
->failed_num
[0] = -1;
3013 s
->failed_num
[1] = -1;
3015 /* Now to look around and see what can be done */
3017 spin_lock_irq(&conf
->device_lock
);
3018 for (i
=disks
; i
--; ) {
3019 struct md_rdev
*rdev
;
3026 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3027 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
3028 /* maybe we can reply to a read
3030 * new wantfill requests are only permitted while
3031 * ops_complete_biofill is guaranteed to be inactive
3033 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3034 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3035 set_bit(R5_Wantfill
, &dev
->flags
);
3037 /* now count some things */
3038 if (test_bit(R5_LOCKED
, &dev
->flags
))
3040 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3042 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3044 BUG_ON(s
->compute
> 2);
3047 if (test_bit(R5_Wantfill
, &dev
->flags
))
3049 else if (dev
->toread
)
3053 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3058 /* Prefer to use the replacement for reads, but only
3059 * if it is recovered enough and has no bad blocks.
3061 rdev
= rcu_dereference(conf
->disks
[i
].replacement
);
3062 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) &&
3063 rdev
->recovery_offset
>= sh
->sector
+ STRIPE_SECTORS
&&
3064 !is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3065 &first_bad
, &bad_sectors
))
3066 set_bit(R5_ReadRepl
, &dev
->flags
);
3068 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3069 clear_bit(R5_ReadRepl
, &dev
->flags
);
3071 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3074 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3075 &first_bad
, &bad_sectors
);
3076 if (s
->blocked_rdev
== NULL
3077 && (test_bit(Blocked
, &rdev
->flags
)
3080 set_bit(BlockedBadBlocks
,
3082 s
->blocked_rdev
= rdev
;
3083 atomic_inc(&rdev
->nr_pending
);
3086 clear_bit(R5_Insync
, &dev
->flags
);
3090 /* also not in-sync */
3091 if (!test_bit(WriteErrorSeen
, &rdev
->flags
)) {
3092 /* treat as in-sync, but with a read error
3093 * which we can now try to correct
3095 set_bit(R5_Insync
, &dev
->flags
);
3096 set_bit(R5_ReadError
, &dev
->flags
);
3098 } else if (test_bit(In_sync
, &rdev
->flags
))
3099 set_bit(R5_Insync
, &dev
->flags
);
3100 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3101 /* in sync if before recovery_offset */
3102 set_bit(R5_Insync
, &dev
->flags
);
3103 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3104 test_bit(R5_Expanded
, &dev
->flags
))
3105 /* If we've reshaped into here, we assume it is Insync.
3106 * We will shortly update recovery_offset to make
3109 set_bit(R5_Insync
, &dev
->flags
);
3111 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3112 /* This flag does not apply to '.replacement'
3113 * only to .rdev, so make sure to check that*/
3114 struct md_rdev
*rdev2
= rcu_dereference(
3115 conf
->disks
[i
].rdev
);
3117 clear_bit(R5_Insync
, &dev
->flags
);
3118 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3119 s
->handle_bad_blocks
= 1;
3120 atomic_inc(&rdev2
->nr_pending
);
3122 clear_bit(R5_WriteError
, &dev
->flags
);
3124 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3125 /* This flag does not apply to '.replacement'
3126 * only to .rdev, so make sure to check that*/
3127 struct md_rdev
*rdev2
= rcu_dereference(
3128 conf
->disks
[i
].rdev
);
3129 if (rdev2
&& !test_bit(Faulty
, &rdev2
->flags
)) {
3130 s
->handle_bad_blocks
= 1;
3131 atomic_inc(&rdev2
->nr_pending
);
3133 clear_bit(R5_MadeGood
, &dev
->flags
);
3135 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3136 /* The ReadError flag will just be confusing now */
3137 clear_bit(R5_ReadError
, &dev
->flags
);
3138 clear_bit(R5_ReWrite
, &dev
->flags
);
3140 if (test_bit(R5_ReadError
, &dev
->flags
))
3141 clear_bit(R5_Insync
, &dev
->flags
);
3142 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3144 s
->failed_num
[s
->failed
] = i
;
3148 spin_unlock_irq(&conf
->device_lock
);
3152 static void handle_stripe(struct stripe_head
*sh
)
3154 struct stripe_head_state s
;
3155 struct r5conf
*conf
= sh
->raid_conf
;
3158 int disks
= sh
->disks
;
3159 struct r5dev
*pdev
, *qdev
;
3161 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3162 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3163 /* already being handled, ensure it gets handled
3164 * again when current action finishes */
3165 set_bit(STRIPE_HANDLE
, &sh
->state
);
3169 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3170 set_bit(STRIPE_SYNCING
, &sh
->state
);
3171 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3173 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3175 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3176 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3177 (unsigned long long)sh
->sector
, sh
->state
,
3178 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3179 sh
->check_state
, sh
->reconstruct_state
);
3181 analyse_stripe(sh
, &s
);
3183 if (s
.handle_bad_blocks
) {
3184 set_bit(STRIPE_HANDLE
, &sh
->state
);
3188 if (unlikely(s
.blocked_rdev
)) {
3189 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3190 s
.to_write
|| s
.written
) {
3191 set_bit(STRIPE_HANDLE
, &sh
->state
);
3194 /* There is nothing for the blocked_rdev to block */
3195 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3196 s
.blocked_rdev
= NULL
;
3199 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3200 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3201 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3204 pr_debug("locked=%d uptodate=%d to_read=%d"
3205 " to_write=%d failed=%d failed_num=%d,%d\n",
3206 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3207 s
.failed_num
[0], s
.failed_num
[1]);
3208 /* check if the array has lost more than max_degraded devices and,
3209 * if so, some requests might need to be failed.
3211 if (s
.failed
> conf
->max_degraded
) {
3212 sh
->check_state
= 0;
3213 sh
->reconstruct_state
= 0;
3214 if (s
.to_read
+s
.to_write
+s
.written
)
3215 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3217 handle_failed_sync(conf
, sh
, &s
);
3221 * might be able to return some write requests if the parity blocks
3222 * are safe, or on a failed drive
3224 pdev
= &sh
->dev
[sh
->pd_idx
];
3225 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3226 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3227 qdev
= &sh
->dev
[sh
->qd_idx
];
3228 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3229 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3233 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3234 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3235 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3236 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3237 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3238 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3239 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3241 /* Now we might consider reading some blocks, either to check/generate
3242 * parity, or to satisfy requests
3243 * or to load a block that is being partially written.
3245 if (s
.to_read
|| s
.non_overwrite
3246 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3247 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3248 handle_stripe_fill(sh
, &s
, disks
);
3250 /* Now we check to see if any write operations have recently
3254 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3256 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3257 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3258 sh
->reconstruct_state
= reconstruct_state_idle
;
3260 /* All the 'written' buffers and the parity block are ready to
3261 * be written back to disk
3263 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3264 BUG_ON(sh
->qd_idx
>= 0 &&
3265 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
));
3266 for (i
= disks
; i
--; ) {
3267 struct r5dev
*dev
= &sh
->dev
[i
];
3268 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3269 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3271 pr_debug("Writing block %d\n", i
);
3272 set_bit(R5_Wantwrite
, &dev
->flags
);
3275 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3276 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3278 set_bit(STRIPE_INSYNC
, &sh
->state
);
3281 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3282 s
.dec_preread_active
= 1;
3285 /* Now to consider new write requests and what else, if anything
3286 * should be read. We do not handle new writes when:
3287 * 1/ A 'write' operation (copy+xor) is already in flight.
3288 * 2/ A 'check' operation is in flight, as it may clobber the parity
3291 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3292 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3294 /* maybe we need to check and possibly fix the parity for this stripe
3295 * Any reads will already have been scheduled, so we just see if enough
3296 * data is available. The parity check is held off while parity
3297 * dependent operations are in flight.
3299 if (sh
->check_state
||
3300 (s
.syncing
&& s
.locked
== 0 &&
3301 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3302 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3303 if (conf
->level
== 6)
3304 handle_parity_checks6(conf
, sh
, &s
, disks
);
3306 handle_parity_checks5(conf
, sh
, &s
, disks
);
3309 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3310 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3311 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3314 /* If the failed drives are just a ReadError, then we might need
3315 * to progress the repair/check process
3317 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3318 for (i
= 0; i
< s
.failed
; i
++) {
3319 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3320 if (test_bit(R5_ReadError
, &dev
->flags
)
3321 && !test_bit(R5_LOCKED
, &dev
->flags
)
3322 && test_bit(R5_UPTODATE
, &dev
->flags
)
3324 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3325 set_bit(R5_Wantwrite
, &dev
->flags
);
3326 set_bit(R5_ReWrite
, &dev
->flags
);
3327 set_bit(R5_LOCKED
, &dev
->flags
);
3330 /* let's read it back */
3331 set_bit(R5_Wantread
, &dev
->flags
);
3332 set_bit(R5_LOCKED
, &dev
->flags
);
3339 /* Finish reconstruct operations initiated by the expansion process */
3340 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3341 struct stripe_head
*sh_src
3342 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3343 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3344 /* sh cannot be written until sh_src has been read.
3345 * so arrange for sh to be delayed a little
3347 set_bit(STRIPE_DELAYED
, &sh
->state
);
3348 set_bit(STRIPE_HANDLE
, &sh
->state
);
3349 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3351 atomic_inc(&conf
->preread_active_stripes
);
3352 release_stripe(sh_src
);
3356 release_stripe(sh_src
);
3358 sh
->reconstruct_state
= reconstruct_state_idle
;
3359 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3360 for (i
= conf
->raid_disks
; i
--; ) {
3361 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3362 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3367 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3368 !sh
->reconstruct_state
) {
3369 /* Need to write out all blocks after computing parity */
3370 sh
->disks
= conf
->raid_disks
;
3371 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3372 schedule_reconstruction(sh
, &s
, 1, 1);
3373 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3374 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3375 atomic_dec(&conf
->reshape_stripes
);
3376 wake_up(&conf
->wait_for_overlap
);
3377 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3380 if (s
.expanding
&& s
.locked
== 0 &&
3381 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3382 handle_stripe_expansion(conf
, sh
);
3385 /* wait for this device to become unblocked */
3386 if (conf
->mddev
->external
&& unlikely(s
.blocked_rdev
))
3387 md_wait_for_blocked_rdev(s
.blocked_rdev
, conf
->mddev
);
3389 if (s
.handle_bad_blocks
)
3390 for (i
= disks
; i
--; ) {
3391 struct md_rdev
*rdev
;
3392 struct r5dev
*dev
= &sh
->dev
[i
];
3393 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3394 /* We own a safe reference to the rdev */
3395 rdev
= conf
->disks
[i
].rdev
;
3396 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3398 md_error(conf
->mddev
, rdev
);
3399 rdev_dec_pending(rdev
, conf
->mddev
);
3401 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3402 rdev
= conf
->disks
[i
].rdev
;
3403 rdev_clear_badblocks(rdev
, sh
->sector
,
3405 rdev_dec_pending(rdev
, conf
->mddev
);
3410 raid_run_ops(sh
, s
.ops_request
);
3414 if (s
.dec_preread_active
) {
3415 /* We delay this until after ops_run_io so that if make_request
3416 * is waiting on a flush, it won't continue until the writes
3417 * have actually been submitted.
3419 atomic_dec(&conf
->preread_active_stripes
);
3420 if (atomic_read(&conf
->preread_active_stripes
) <
3422 md_wakeup_thread(conf
->mddev
->thread
);
3425 return_io(s
.return_bi
);
3427 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3430 static void raid5_activate_delayed(struct r5conf
*conf
)
3432 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3433 while (!list_empty(&conf
->delayed_list
)) {
3434 struct list_head
*l
= conf
->delayed_list
.next
;
3435 struct stripe_head
*sh
;
3436 sh
= list_entry(l
, struct stripe_head
, lru
);
3438 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3439 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3440 atomic_inc(&conf
->preread_active_stripes
);
3441 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3446 static void activate_bit_delay(struct r5conf
*conf
)
3448 /* device_lock is held */
3449 struct list_head head
;
3450 list_add(&head
, &conf
->bitmap_list
);
3451 list_del_init(&conf
->bitmap_list
);
3452 while (!list_empty(&head
)) {
3453 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3454 list_del_init(&sh
->lru
);
3455 atomic_inc(&sh
->count
);
3456 __release_stripe(conf
, sh
);
3460 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3462 struct r5conf
*conf
= mddev
->private;
3464 /* No difference between reads and writes. Just check
3465 * how busy the stripe_cache is
3468 if (conf
->inactive_blocked
)
3472 if (list_empty_careful(&conf
->inactive_list
))
3477 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3479 static int raid5_congested(void *data
, int bits
)
3481 struct mddev
*mddev
= data
;
3483 return mddev_congested(mddev
, bits
) ||
3484 md_raid5_congested(mddev
, bits
);
3487 /* We want read requests to align with chunks where possible,
3488 * but write requests don't need to.
3490 static int raid5_mergeable_bvec(struct request_queue
*q
,
3491 struct bvec_merge_data
*bvm
,
3492 struct bio_vec
*biovec
)
3494 struct mddev
*mddev
= q
->queuedata
;
3495 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3497 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3498 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3500 if ((bvm
->bi_rw
& 1) == WRITE
)
3501 return biovec
->bv_len
; /* always allow writes to be mergeable */
3503 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3504 chunk_sectors
= mddev
->new_chunk_sectors
;
3505 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3506 if (max
< 0) max
= 0;
3507 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3508 return biovec
->bv_len
;
3514 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3516 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3517 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3518 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3520 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3521 chunk_sectors
= mddev
->new_chunk_sectors
;
3522 return chunk_sectors
>=
3523 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3527 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3528 * later sampled by raid5d.
3530 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3532 unsigned long flags
;
3534 spin_lock_irqsave(&conf
->device_lock
, flags
);
3536 bi
->bi_next
= conf
->retry_read_aligned_list
;
3537 conf
->retry_read_aligned_list
= bi
;
3539 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3540 md_wakeup_thread(conf
->mddev
->thread
);
3544 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3548 bi
= conf
->retry_read_aligned
;
3550 conf
->retry_read_aligned
= NULL
;
3553 bi
= conf
->retry_read_aligned_list
;
3555 conf
->retry_read_aligned_list
= bi
->bi_next
;
3558 * this sets the active strip count to 1 and the processed
3559 * strip count to zero (upper 8 bits)
3561 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3569 * The "raid5_align_endio" should check if the read succeeded and if it
3570 * did, call bio_endio on the original bio (having bio_put the new bio
3572 * If the read failed..
3574 static void raid5_align_endio(struct bio
*bi
, int error
)
3576 struct bio
* raid_bi
= bi
->bi_private
;
3577 struct mddev
*mddev
;
3578 struct r5conf
*conf
;
3579 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3580 struct md_rdev
*rdev
;
3584 rdev
= (void*)raid_bi
->bi_next
;
3585 raid_bi
->bi_next
= NULL
;
3586 mddev
= rdev
->mddev
;
3587 conf
= mddev
->private;
3589 rdev_dec_pending(rdev
, conf
->mddev
);
3591 if (!error
&& uptodate
) {
3592 bio_endio(raid_bi
, 0);
3593 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3594 wake_up(&conf
->wait_for_stripe
);
3599 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3601 add_bio_to_retry(raid_bi
, conf
);
3604 static int bio_fits_rdev(struct bio
*bi
)
3606 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3608 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3610 blk_recount_segments(q
, bi
);
3611 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3614 if (q
->merge_bvec_fn
)
3615 /* it's too hard to apply the merge_bvec_fn at this stage,
3624 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3626 struct r5conf
*conf
= mddev
->private;
3628 struct bio
* align_bi
;
3629 struct md_rdev
*rdev
;
3630 sector_t end_sector
;
3632 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3633 pr_debug("chunk_aligned_read : non aligned\n");
3637 * use bio_clone_mddev to make a copy of the bio
3639 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3643 * set bi_end_io to a new function, and set bi_private to the
3646 align_bi
->bi_end_io
= raid5_align_endio
;
3647 align_bi
->bi_private
= raid_bio
;
3651 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3655 end_sector
= align_bi
->bi_sector
+ (align_bi
->bi_size
>> 9);
3657 rdev
= rcu_dereference(conf
->disks
[dd_idx
].replacement
);
3658 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
) ||
3659 rdev
->recovery_offset
< end_sector
) {
3660 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3662 (test_bit(Faulty
, &rdev
->flags
) ||
3663 !(test_bit(In_sync
, &rdev
->flags
) ||
3664 rdev
->recovery_offset
>= end_sector
)))
3671 atomic_inc(&rdev
->nr_pending
);
3673 raid_bio
->bi_next
= (void*)rdev
;
3674 align_bi
->bi_bdev
= rdev
->bdev
;
3675 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3676 align_bi
->bi_sector
+= rdev
->data_offset
;
3678 if (!bio_fits_rdev(align_bi
) ||
3679 is_badblock(rdev
, align_bi
->bi_sector
, align_bi
->bi_size
>>9,
3680 &first_bad
, &bad_sectors
)) {
3681 /* too big in some way, or has a known bad block */
3683 rdev_dec_pending(rdev
, mddev
);
3687 spin_lock_irq(&conf
->device_lock
);
3688 wait_event_lock_irq(conf
->wait_for_stripe
,
3690 conf
->device_lock
, /* nothing */);
3691 atomic_inc(&conf
->active_aligned_reads
);
3692 spin_unlock_irq(&conf
->device_lock
);
3694 generic_make_request(align_bi
);
3703 /* __get_priority_stripe - get the next stripe to process
3705 * Full stripe writes are allowed to pass preread active stripes up until
3706 * the bypass_threshold is exceeded. In general the bypass_count
3707 * increments when the handle_list is handled before the hold_list; however, it
3708 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3709 * stripe with in flight i/o. The bypass_count will be reset when the
3710 * head of the hold_list has changed, i.e. the head was promoted to the
3713 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
3715 struct stripe_head
*sh
;
3717 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3719 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3720 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3721 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3723 if (!list_empty(&conf
->handle_list
)) {
3724 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3726 if (list_empty(&conf
->hold_list
))
3727 conf
->bypass_count
= 0;
3728 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3729 if (conf
->hold_list
.next
== conf
->last_hold
)
3730 conf
->bypass_count
++;
3732 conf
->last_hold
= conf
->hold_list
.next
;
3733 conf
->bypass_count
-= conf
->bypass_threshold
;
3734 if (conf
->bypass_count
< 0)
3735 conf
->bypass_count
= 0;
3738 } else if (!list_empty(&conf
->hold_list
) &&
3739 ((conf
->bypass_threshold
&&
3740 conf
->bypass_count
> conf
->bypass_threshold
) ||
3741 atomic_read(&conf
->pending_full_writes
) == 0)) {
3742 sh
= list_entry(conf
->hold_list
.next
,
3744 conf
->bypass_count
-= conf
->bypass_threshold
;
3745 if (conf
->bypass_count
< 0)
3746 conf
->bypass_count
= 0;
3750 list_del_init(&sh
->lru
);
3751 atomic_inc(&sh
->count
);
3752 BUG_ON(atomic_read(&sh
->count
) != 1);
3756 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
3758 struct r5conf
*conf
= mddev
->private;
3760 sector_t new_sector
;
3761 sector_t logical_sector
, last_sector
;
3762 struct stripe_head
*sh
;
3763 const int rw
= bio_data_dir(bi
);
3767 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
3768 md_flush_request(mddev
, bi
);
3772 md_write_start(mddev
, bi
);
3775 mddev
->reshape_position
== MaxSector
&&
3776 chunk_aligned_read(mddev
,bi
))
3779 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3780 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3782 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3784 plugged
= mddev_check_plugged(mddev
);
3785 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3787 int disks
, data_disks
;
3792 disks
= conf
->raid_disks
;
3793 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3794 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
3795 /* spinlock is needed as reshape_progress may be
3796 * 64bit on a 32bit platform, and so it might be
3797 * possible to see a half-updated value
3798 * Of course reshape_progress could change after
3799 * the lock is dropped, so once we get a reference
3800 * to the stripe that we think it is, we will have
3803 spin_lock_irq(&conf
->device_lock
);
3804 if (mddev
->delta_disks
< 0
3805 ? logical_sector
< conf
->reshape_progress
3806 : logical_sector
>= conf
->reshape_progress
) {
3807 disks
= conf
->previous_raid_disks
;
3810 if (mddev
->delta_disks
< 0
3811 ? logical_sector
< conf
->reshape_safe
3812 : logical_sector
>= conf
->reshape_safe
) {
3813 spin_unlock_irq(&conf
->device_lock
);
3818 spin_unlock_irq(&conf
->device_lock
);
3820 data_disks
= disks
- conf
->max_degraded
;
3822 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3825 pr_debug("raid456: make_request, sector %llu logical %llu\n",
3826 (unsigned long long)new_sector
,
3827 (unsigned long long)logical_sector
);
3829 sh
= get_active_stripe(conf
, new_sector
, previous
,
3830 (bi
->bi_rw
&RWA_MASK
), 0);
3832 if (unlikely(previous
)) {
3833 /* expansion might have moved on while waiting for a
3834 * stripe, so we must do the range check again.
3835 * Expansion could still move past after this
3836 * test, but as we are holding a reference to
3837 * 'sh', we know that if that happens,
3838 * STRIPE_EXPANDING will get set and the expansion
3839 * won't proceed until we finish with the stripe.
3842 spin_lock_irq(&conf
->device_lock
);
3843 if (mddev
->delta_disks
< 0
3844 ? logical_sector
>= conf
->reshape_progress
3845 : logical_sector
< conf
->reshape_progress
)
3846 /* mismatch, need to try again */
3848 spin_unlock_irq(&conf
->device_lock
);
3857 logical_sector
>= mddev
->suspend_lo
&&
3858 logical_sector
< mddev
->suspend_hi
) {
3860 /* As the suspend_* range is controlled by
3861 * userspace, we want an interruptible
3864 flush_signals(current
);
3865 prepare_to_wait(&conf
->wait_for_overlap
,
3866 &w
, TASK_INTERRUPTIBLE
);
3867 if (logical_sector
>= mddev
->suspend_lo
&&
3868 logical_sector
< mddev
->suspend_hi
)
3873 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
3874 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
3875 /* Stripe is busy expanding or
3876 * add failed due to overlap. Flush everything
3879 md_wakeup_thread(mddev
->thread
);
3884 finish_wait(&conf
->wait_for_overlap
, &w
);
3885 set_bit(STRIPE_HANDLE
, &sh
->state
);
3886 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3887 if ((bi
->bi_rw
& REQ_SYNC
) &&
3888 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3889 atomic_inc(&conf
->preread_active_stripes
);
3892 /* cannot get stripe for read-ahead, just give-up */
3893 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3894 finish_wait(&conf
->wait_for_overlap
, &w
);
3900 md_wakeup_thread(mddev
->thread
);
3902 spin_lock_irq(&conf
->device_lock
);
3903 remaining
= raid5_dec_bi_phys_segments(bi
);
3904 spin_unlock_irq(&conf
->device_lock
);
3905 if (remaining
== 0) {
3908 md_write_end(mddev
);
3914 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
3916 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
3918 /* reshaping is quite different to recovery/resync so it is
3919 * handled quite separately ... here.
3921 * On each call to sync_request, we gather one chunk worth of
3922 * destination stripes and flag them as expanding.
3923 * Then we find all the source stripes and request reads.
3924 * As the reads complete, handle_stripe will copy the data
3925 * into the destination stripe and release that stripe.
3927 struct r5conf
*conf
= mddev
->private;
3928 struct stripe_head
*sh
;
3929 sector_t first_sector
, last_sector
;
3930 int raid_disks
= conf
->previous_raid_disks
;
3931 int data_disks
= raid_disks
- conf
->max_degraded
;
3932 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
3935 sector_t writepos
, readpos
, safepos
;
3936 sector_t stripe_addr
;
3937 int reshape_sectors
;
3938 struct list_head stripes
;
3940 if (sector_nr
== 0) {
3941 /* If restarting in the middle, skip the initial sectors */
3942 if (mddev
->delta_disks
< 0 &&
3943 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
3944 sector_nr
= raid5_size(mddev
, 0, 0)
3945 - conf
->reshape_progress
;
3946 } else if (mddev
->delta_disks
>= 0 &&
3947 conf
->reshape_progress
> 0)
3948 sector_nr
= conf
->reshape_progress
;
3949 sector_div(sector_nr
, new_data_disks
);
3951 mddev
->curr_resync_completed
= sector_nr
;
3952 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
3958 /* We need to process a full chunk at a time.
3959 * If old and new chunk sizes differ, we need to process the
3962 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
3963 reshape_sectors
= mddev
->new_chunk_sectors
;
3965 reshape_sectors
= mddev
->chunk_sectors
;
3967 /* we update the metadata when there is more than 3Meg
3968 * in the block range (that is rather arbitrary, should
3969 * probably be time based) or when the data about to be
3970 * copied would over-write the source of the data at
3971 * the front of the range.
3972 * i.e. one new_stripe along from reshape_progress new_maps
3973 * to after where reshape_safe old_maps to
3975 writepos
= conf
->reshape_progress
;
3976 sector_div(writepos
, new_data_disks
);
3977 readpos
= conf
->reshape_progress
;
3978 sector_div(readpos
, data_disks
);
3979 safepos
= conf
->reshape_safe
;
3980 sector_div(safepos
, data_disks
);
3981 if (mddev
->delta_disks
< 0) {
3982 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
3983 readpos
+= reshape_sectors
;
3984 safepos
+= reshape_sectors
;
3986 writepos
+= reshape_sectors
;
3987 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
3988 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
3991 /* 'writepos' is the most advanced device address we might write.
3992 * 'readpos' is the least advanced device address we might read.
3993 * 'safepos' is the least address recorded in the metadata as having
3995 * If 'readpos' is behind 'writepos', then there is no way that we can
3996 * ensure safety in the face of a crash - that must be done by userspace
3997 * making a backup of the data. So in that case there is no particular
3998 * rush to update metadata.
3999 * Otherwise if 'safepos' is behind 'writepos', then we really need to
4000 * update the metadata to advance 'safepos' to match 'readpos' so that
4001 * we can be safe in the event of a crash.
4002 * So we insist on updating metadata if safepos is behind writepos and
4003 * readpos is beyond writepos.
4004 * In any case, update the metadata every 10 seconds.
4005 * Maybe that number should be configurable, but I'm not sure it is
4006 * worth it.... maybe it could be a multiple of safemode_delay???
4008 if ((mddev
->delta_disks
< 0
4009 ? (safepos
> writepos
&& readpos
< writepos
)
4010 : (safepos
< writepos
&& readpos
> writepos
)) ||
4011 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
4012 /* Cannot proceed until we've updated the superblock... */
4013 wait_event(conf
->wait_for_overlap
,
4014 atomic_read(&conf
->reshape_stripes
)==0);
4015 mddev
->reshape_position
= conf
->reshape_progress
;
4016 mddev
->curr_resync_completed
= sector_nr
;
4017 conf
->reshape_checkpoint
= jiffies
;
4018 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4019 md_wakeup_thread(mddev
->thread
);
4020 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
4021 kthread_should_stop());
4022 spin_lock_irq(&conf
->device_lock
);
4023 conf
->reshape_safe
= mddev
->reshape_position
;
4024 spin_unlock_irq(&conf
->device_lock
);
4025 wake_up(&conf
->wait_for_overlap
);
4026 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4029 if (mddev
->delta_disks
< 0) {
4030 BUG_ON(conf
->reshape_progress
== 0);
4031 stripe_addr
= writepos
;
4032 BUG_ON((mddev
->dev_sectors
&
4033 ~((sector_t
)reshape_sectors
- 1))
4034 - reshape_sectors
- stripe_addr
4037 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
4038 stripe_addr
= sector_nr
;
4040 INIT_LIST_HEAD(&stripes
);
4041 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
4043 int skipped_disk
= 0;
4044 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4045 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4046 atomic_inc(&conf
->reshape_stripes
);
4047 /* If any of this stripe is beyond the end of the old
4048 * array, then we need to zero those blocks
4050 for (j
=sh
->disks
; j
--;) {
4052 if (j
== sh
->pd_idx
)
4054 if (conf
->level
== 6 &&
4057 s
= compute_blocknr(sh
, j
, 0);
4058 if (s
< raid5_size(mddev
, 0, 0)) {
4062 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4063 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4064 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4066 if (!skipped_disk
) {
4067 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4068 set_bit(STRIPE_HANDLE
, &sh
->state
);
4070 list_add(&sh
->lru
, &stripes
);
4072 spin_lock_irq(&conf
->device_lock
);
4073 if (mddev
->delta_disks
< 0)
4074 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4076 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4077 spin_unlock_irq(&conf
->device_lock
);
4078 /* Ok, those stripe are ready. We can start scheduling
4079 * reads on the source stripes.
4080 * The source stripes are determined by mapping the first and last
4081 * block on the destination stripes.
4084 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4087 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4088 * new_data_disks
- 1),
4090 if (last_sector
>= mddev
->dev_sectors
)
4091 last_sector
= mddev
->dev_sectors
- 1;
4092 while (first_sector
<= last_sector
) {
4093 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4094 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4095 set_bit(STRIPE_HANDLE
, &sh
->state
);
4097 first_sector
+= STRIPE_SECTORS
;
4099 /* Now that the sources are clearly marked, we can release
4100 * the destination stripes
4102 while (!list_empty(&stripes
)) {
4103 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4104 list_del_init(&sh
->lru
);
4107 /* If this takes us to the resync_max point where we have to pause,
4108 * then we need to write out the superblock.
4110 sector_nr
+= reshape_sectors
;
4111 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4112 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4113 /* Cannot proceed until we've updated the superblock... */
4114 wait_event(conf
->wait_for_overlap
,
4115 atomic_read(&conf
->reshape_stripes
) == 0);
4116 mddev
->reshape_position
= conf
->reshape_progress
;
4117 mddev
->curr_resync_completed
= sector_nr
;
4118 conf
->reshape_checkpoint
= jiffies
;
4119 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4120 md_wakeup_thread(mddev
->thread
);
4121 wait_event(mddev
->sb_wait
,
4122 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4123 || kthread_should_stop());
4124 spin_lock_irq(&conf
->device_lock
);
4125 conf
->reshape_safe
= mddev
->reshape_position
;
4126 spin_unlock_irq(&conf
->device_lock
);
4127 wake_up(&conf
->wait_for_overlap
);
4128 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4130 return reshape_sectors
;
4133 /* FIXME go_faster isn't used */
4134 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4136 struct r5conf
*conf
= mddev
->private;
4137 struct stripe_head
*sh
;
4138 sector_t max_sector
= mddev
->dev_sectors
;
4139 sector_t sync_blocks
;
4140 int still_degraded
= 0;
4143 if (sector_nr
>= max_sector
) {
4144 /* just being told to finish up .. nothing much to do */
4146 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4151 if (mddev
->curr_resync
< max_sector
) /* aborted */
4152 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4154 else /* completed sync */
4156 bitmap_close_sync(mddev
->bitmap
);
4161 /* Allow raid5_quiesce to complete */
4162 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4164 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4165 return reshape_request(mddev
, sector_nr
, skipped
);
4167 /* No need to check resync_max as we never do more than one
4168 * stripe, and as resync_max will always be on a chunk boundary,
4169 * if the check in md_do_sync didn't fire, there is no chance
4170 * of overstepping resync_max here
4173 /* if there is too many failed drives and we are trying
4174 * to resync, then assert that we are finished, because there is
4175 * nothing we can do.
4177 if (mddev
->degraded
>= conf
->max_degraded
&&
4178 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4179 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4183 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4184 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4185 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4186 /* we can skip this block, and probably more */
4187 sync_blocks
/= STRIPE_SECTORS
;
4189 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4193 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4195 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4197 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4198 /* make sure we don't swamp the stripe cache if someone else
4199 * is trying to get access
4201 schedule_timeout_uninterruptible(1);
4203 /* Need to check if array will still be degraded after recovery/resync
4204 * We don't need to check the 'failed' flag as when that gets set,
4207 for (i
= 0; i
< conf
->raid_disks
; i
++)
4208 if (conf
->disks
[i
].rdev
== NULL
)
4211 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4213 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4218 return STRIPE_SECTORS
;
4221 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4223 /* We may not be able to submit a whole bio at once as there
4224 * may not be enough stripe_heads available.
4225 * We cannot pre-allocate enough stripe_heads as we may need
4226 * more than exist in the cache (if we allow ever large chunks).
4227 * So we do one stripe head at a time and record in
4228 * ->bi_hw_segments how many have been done.
4230 * We *know* that this entire raid_bio is in one chunk, so
4231 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4233 struct stripe_head
*sh
;
4235 sector_t sector
, logical_sector
, last_sector
;
4240 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4241 sector
= raid5_compute_sector(conf
, logical_sector
,
4243 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4245 for (; logical_sector
< last_sector
;
4246 logical_sector
+= STRIPE_SECTORS
,
4247 sector
+= STRIPE_SECTORS
,
4250 if (scnt
< raid5_bi_hw_segments(raid_bio
))
4251 /* already done this stripe */
4254 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4257 /* failed to get a stripe - must wait */
4258 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4259 conf
->retry_read_aligned
= raid_bio
;
4263 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4265 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4266 conf
->retry_read_aligned
= raid_bio
;
4274 spin_lock_irq(&conf
->device_lock
);
4275 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
4276 spin_unlock_irq(&conf
->device_lock
);
4278 bio_endio(raid_bio
, 0);
4279 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4280 wake_up(&conf
->wait_for_stripe
);
4286 * This is our raid5 kernel thread.
4288 * We scan the hash table for stripes which can be handled now.
4289 * During the scan, completed stripes are saved for us by the interrupt
4290 * handler, so that they will not have to wait for our next wakeup.
4292 static void raid5d(struct mddev
*mddev
)
4294 struct stripe_head
*sh
;
4295 struct r5conf
*conf
= mddev
->private;
4297 struct blk_plug plug
;
4299 pr_debug("+++ raid5d active\n");
4301 md_check_recovery(mddev
);
4303 blk_start_plug(&plug
);
4305 spin_lock_irq(&conf
->device_lock
);
4309 if (atomic_read(&mddev
->plug_cnt
) == 0 &&
4310 !list_empty(&conf
->bitmap_list
)) {
4311 /* Now is a good time to flush some bitmap updates */
4313 spin_unlock_irq(&conf
->device_lock
);
4314 bitmap_unplug(mddev
->bitmap
);
4315 spin_lock_irq(&conf
->device_lock
);
4316 conf
->seq_write
= conf
->seq_flush
;
4317 activate_bit_delay(conf
);
4319 if (atomic_read(&mddev
->plug_cnt
) == 0)
4320 raid5_activate_delayed(conf
);
4322 while ((bio
= remove_bio_from_retry(conf
))) {
4324 spin_unlock_irq(&conf
->device_lock
);
4325 ok
= retry_aligned_read(conf
, bio
);
4326 spin_lock_irq(&conf
->device_lock
);
4332 sh
= __get_priority_stripe(conf
);
4336 spin_unlock_irq(&conf
->device_lock
);
4343 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
4344 md_check_recovery(mddev
);
4346 spin_lock_irq(&conf
->device_lock
);
4348 pr_debug("%d stripes handled\n", handled
);
4350 spin_unlock_irq(&conf
->device_lock
);
4352 async_tx_issue_pending_all();
4353 blk_finish_plug(&plug
);
4355 pr_debug("--- raid5d inactive\n");
4359 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4361 struct r5conf
*conf
= mddev
->private;
4363 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4369 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4371 struct r5conf
*conf
= mddev
->private;
4374 if (size
<= 16 || size
> 32768)
4376 while (size
< conf
->max_nr_stripes
) {
4377 if (drop_one_stripe(conf
))
4378 conf
->max_nr_stripes
--;
4382 err
= md_allow_write(mddev
);
4385 while (size
> conf
->max_nr_stripes
) {
4386 if (grow_one_stripe(conf
))
4387 conf
->max_nr_stripes
++;
4392 EXPORT_SYMBOL(raid5_set_cache_size
);
4395 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4397 struct r5conf
*conf
= mddev
->private;
4401 if (len
>= PAGE_SIZE
)
4406 if (strict_strtoul(page
, 10, &new))
4408 err
= raid5_set_cache_size(mddev
, new);
4414 static struct md_sysfs_entry
4415 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4416 raid5_show_stripe_cache_size
,
4417 raid5_store_stripe_cache_size
);
4420 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4422 struct r5conf
*conf
= mddev
->private;
4424 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4430 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4432 struct r5conf
*conf
= mddev
->private;
4434 if (len
>= PAGE_SIZE
)
4439 if (strict_strtoul(page
, 10, &new))
4441 if (new > conf
->max_nr_stripes
)
4443 conf
->bypass_threshold
= new;
4447 static struct md_sysfs_entry
4448 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4450 raid5_show_preread_threshold
,
4451 raid5_store_preread_threshold
);
4454 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4456 struct r5conf
*conf
= mddev
->private;
4458 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4463 static struct md_sysfs_entry
4464 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4466 static struct attribute
*raid5_attrs
[] = {
4467 &raid5_stripecache_size
.attr
,
4468 &raid5_stripecache_active
.attr
,
4469 &raid5_preread_bypass_threshold
.attr
,
4472 static struct attribute_group raid5_attrs_group
= {
4474 .attrs
= raid5_attrs
,
4478 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4480 struct r5conf
*conf
= mddev
->private;
4483 sectors
= mddev
->dev_sectors
;
4485 /* size is defined by the smallest of previous and new size */
4486 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4488 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4489 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4490 return sectors
* (raid_disks
- conf
->max_degraded
);
4493 static void raid5_free_percpu(struct r5conf
*conf
)
4495 struct raid5_percpu
*percpu
;
4502 for_each_possible_cpu(cpu
) {
4503 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4504 safe_put_page(percpu
->spare_page
);
4505 kfree(percpu
->scribble
);
4507 #ifdef CONFIG_HOTPLUG_CPU
4508 unregister_cpu_notifier(&conf
->cpu_notify
);
4512 free_percpu(conf
->percpu
);
4515 static void free_conf(struct r5conf
*conf
)
4517 shrink_stripes(conf
);
4518 raid5_free_percpu(conf
);
4520 kfree(conf
->stripe_hashtbl
);
4524 #ifdef CONFIG_HOTPLUG_CPU
4525 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4528 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
4529 long cpu
= (long)hcpu
;
4530 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4533 case CPU_UP_PREPARE
:
4534 case CPU_UP_PREPARE_FROZEN
:
4535 if (conf
->level
== 6 && !percpu
->spare_page
)
4536 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4537 if (!percpu
->scribble
)
4538 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4540 if (!percpu
->scribble
||
4541 (conf
->level
== 6 && !percpu
->spare_page
)) {
4542 safe_put_page(percpu
->spare_page
);
4543 kfree(percpu
->scribble
);
4544 pr_err("%s: failed memory allocation for cpu%ld\n",
4546 return notifier_from_errno(-ENOMEM
);
4550 case CPU_DEAD_FROZEN
:
4551 safe_put_page(percpu
->spare_page
);
4552 kfree(percpu
->scribble
);
4553 percpu
->spare_page
= NULL
;
4554 percpu
->scribble
= NULL
;
4563 static int raid5_alloc_percpu(struct r5conf
*conf
)
4566 struct page
*spare_page
;
4567 struct raid5_percpu __percpu
*allcpus
;
4571 allcpus
= alloc_percpu(struct raid5_percpu
);
4574 conf
->percpu
= allcpus
;
4578 for_each_present_cpu(cpu
) {
4579 if (conf
->level
== 6) {
4580 spare_page
= alloc_page(GFP_KERNEL
);
4585 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4587 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4592 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4594 #ifdef CONFIG_HOTPLUG_CPU
4595 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4596 conf
->cpu_notify
.priority
= 0;
4598 err
= register_cpu_notifier(&conf
->cpu_notify
);
4605 static struct r5conf
*setup_conf(struct mddev
*mddev
)
4607 struct r5conf
*conf
;
4608 int raid_disk
, memory
, max_disks
;
4609 struct md_rdev
*rdev
;
4610 struct disk_info
*disk
;
4612 if (mddev
->new_level
!= 5
4613 && mddev
->new_level
!= 4
4614 && mddev
->new_level
!= 6) {
4615 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4616 mdname(mddev
), mddev
->new_level
);
4617 return ERR_PTR(-EIO
);
4619 if ((mddev
->new_level
== 5
4620 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4621 (mddev
->new_level
== 6
4622 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4623 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4624 mdname(mddev
), mddev
->new_layout
);
4625 return ERR_PTR(-EIO
);
4627 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4628 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4629 mdname(mddev
), mddev
->raid_disks
);
4630 return ERR_PTR(-EINVAL
);
4633 if (!mddev
->new_chunk_sectors
||
4634 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4635 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4636 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4637 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4638 return ERR_PTR(-EINVAL
);
4641 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
4644 spin_lock_init(&conf
->device_lock
);
4645 init_waitqueue_head(&conf
->wait_for_stripe
);
4646 init_waitqueue_head(&conf
->wait_for_overlap
);
4647 INIT_LIST_HEAD(&conf
->handle_list
);
4648 INIT_LIST_HEAD(&conf
->hold_list
);
4649 INIT_LIST_HEAD(&conf
->delayed_list
);
4650 INIT_LIST_HEAD(&conf
->bitmap_list
);
4651 INIT_LIST_HEAD(&conf
->inactive_list
);
4652 atomic_set(&conf
->active_stripes
, 0);
4653 atomic_set(&conf
->preread_active_stripes
, 0);
4654 atomic_set(&conf
->active_aligned_reads
, 0);
4655 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4656 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
4658 conf
->raid_disks
= mddev
->raid_disks
;
4659 if (mddev
->reshape_position
== MaxSector
)
4660 conf
->previous_raid_disks
= mddev
->raid_disks
;
4662 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4663 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4664 conf
->scribble_len
= scribble_len(max_disks
);
4666 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4671 conf
->mddev
= mddev
;
4673 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4676 conf
->level
= mddev
->new_level
;
4677 if (raid5_alloc_percpu(conf
) != 0)
4680 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4682 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4683 raid_disk
= rdev
->raid_disk
;
4684 if (raid_disk
>= max_disks
4687 disk
= conf
->disks
+ raid_disk
;
4691 if (test_bit(In_sync
, &rdev
->flags
)) {
4692 char b
[BDEVNAME_SIZE
];
4693 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4695 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4696 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4697 /* Cannot rely on bitmap to complete recovery */
4701 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4702 conf
->level
= mddev
->new_level
;
4703 if (conf
->level
== 6)
4704 conf
->max_degraded
= 2;
4706 conf
->max_degraded
= 1;
4707 conf
->algorithm
= mddev
->new_layout
;
4708 conf
->max_nr_stripes
= NR_STRIPES
;
4709 conf
->reshape_progress
= mddev
->reshape_position
;
4710 if (conf
->reshape_progress
!= MaxSector
) {
4711 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4712 conf
->prev_algo
= mddev
->layout
;
4715 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4716 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4717 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4719 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4720 mdname(mddev
), memory
);
4723 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4724 mdname(mddev
), memory
);
4726 conf
->thread
= md_register_thread(raid5d
, mddev
, NULL
);
4727 if (!conf
->thread
) {
4729 "md/raid:%s: couldn't allocate thread.\n",
4739 return ERR_PTR(-EIO
);
4741 return ERR_PTR(-ENOMEM
);
4745 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
4748 case ALGORITHM_PARITY_0
:
4749 if (raid_disk
< max_degraded
)
4752 case ALGORITHM_PARITY_N
:
4753 if (raid_disk
>= raid_disks
- max_degraded
)
4756 case ALGORITHM_PARITY_0_6
:
4757 if (raid_disk
== 0 ||
4758 raid_disk
== raid_disks
- 1)
4761 case ALGORITHM_LEFT_ASYMMETRIC_6
:
4762 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
4763 case ALGORITHM_LEFT_SYMMETRIC_6
:
4764 case ALGORITHM_RIGHT_SYMMETRIC_6
:
4765 if (raid_disk
== raid_disks
- 1)
4771 static int run(struct mddev
*mddev
)
4773 struct r5conf
*conf
;
4774 int working_disks
= 0;
4775 int dirty_parity_disks
= 0;
4776 struct md_rdev
*rdev
;
4777 sector_t reshape_offset
= 0;
4779 if (mddev
->recovery_cp
!= MaxSector
)
4780 printk(KERN_NOTICE
"md/raid:%s: not clean"
4781 " -- starting background reconstruction\n",
4783 if (mddev
->reshape_position
!= MaxSector
) {
4784 /* Check that we can continue the reshape.
4785 * Currently only disks can change, it must
4786 * increase, and we must be past the point where
4787 * a stripe over-writes itself
4789 sector_t here_new
, here_old
;
4791 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
4793 if (mddev
->new_level
!= mddev
->level
) {
4794 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
4795 "required - aborting.\n",
4799 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4800 /* reshape_position must be on a new-stripe boundary, and one
4801 * further up in new geometry must map after here in old
4804 here_new
= mddev
->reshape_position
;
4805 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
4806 (mddev
->raid_disks
- max_degraded
))) {
4807 printk(KERN_ERR
"md/raid:%s: reshape_position not "
4808 "on a stripe boundary\n", mdname(mddev
));
4811 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
4812 /* here_new is the stripe we will write to */
4813 here_old
= mddev
->reshape_position
;
4814 sector_div(here_old
, mddev
->chunk_sectors
*
4815 (old_disks
-max_degraded
));
4816 /* here_old is the first stripe that we might need to read
4818 if (mddev
->delta_disks
== 0) {
4819 /* We cannot be sure it is safe to start an in-place
4820 * reshape. It is only safe if user-space if monitoring
4821 * and taking constant backups.
4822 * mdadm always starts a situation like this in
4823 * readonly mode so it can take control before
4824 * allowing any writes. So just check for that.
4826 if ((here_new
* mddev
->new_chunk_sectors
!=
4827 here_old
* mddev
->chunk_sectors
) ||
4829 printk(KERN_ERR
"md/raid:%s: in-place reshape must be started"
4830 " in read-only mode - aborting\n",
4834 } else if (mddev
->delta_disks
< 0
4835 ? (here_new
* mddev
->new_chunk_sectors
<=
4836 here_old
* mddev
->chunk_sectors
)
4837 : (here_new
* mddev
->new_chunk_sectors
>=
4838 here_old
* mddev
->chunk_sectors
)) {
4839 /* Reading from the same stripe as writing to - bad */
4840 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
4841 "auto-recovery - aborting.\n",
4845 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
4847 /* OK, we should be able to continue; */
4849 BUG_ON(mddev
->level
!= mddev
->new_level
);
4850 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
4851 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
4852 BUG_ON(mddev
->delta_disks
!= 0);
4855 if (mddev
->private == NULL
)
4856 conf
= setup_conf(mddev
);
4858 conf
= mddev
->private;
4861 return PTR_ERR(conf
);
4863 mddev
->thread
= conf
->thread
;
4864 conf
->thread
= NULL
;
4865 mddev
->private = conf
;
4868 * 0 for a fully functional array, 1 or 2 for a degraded array.
4870 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4871 if (rdev
->raid_disk
< 0)
4873 if (test_bit(In_sync
, &rdev
->flags
)) {
4877 /* This disc is not fully in-sync. However if it
4878 * just stored parity (beyond the recovery_offset),
4879 * when we don't need to be concerned about the
4880 * array being dirty.
4881 * When reshape goes 'backwards', we never have
4882 * partially completed devices, so we only need
4883 * to worry about reshape going forwards.
4885 /* Hack because v0.91 doesn't store recovery_offset properly. */
4886 if (mddev
->major_version
== 0 &&
4887 mddev
->minor_version
> 90)
4888 rdev
->recovery_offset
= reshape_offset
;
4890 if (rdev
->recovery_offset
< reshape_offset
) {
4891 /* We need to check old and new layout */
4892 if (!only_parity(rdev
->raid_disk
,
4895 conf
->max_degraded
))
4898 if (!only_parity(rdev
->raid_disk
,
4900 conf
->previous_raid_disks
,
4901 conf
->max_degraded
))
4903 dirty_parity_disks
++;
4906 mddev
->degraded
= calc_degraded(conf
);
4908 if (has_failed(conf
)) {
4909 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
4910 " (%d/%d failed)\n",
4911 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
4915 /* device size must be a multiple of chunk size */
4916 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
4917 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
4919 if (mddev
->degraded
> dirty_parity_disks
&&
4920 mddev
->recovery_cp
!= MaxSector
) {
4921 if (mddev
->ok_start_degraded
)
4923 "md/raid:%s: starting dirty degraded array"
4924 " - data corruption possible.\n",
4928 "md/raid:%s: cannot start dirty degraded array.\n",
4934 if (mddev
->degraded
== 0)
4935 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
4936 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
4937 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
4940 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
4941 " out of %d devices, algorithm %d\n",
4942 mdname(mddev
), conf
->level
,
4943 mddev
->raid_disks
- mddev
->degraded
,
4944 mddev
->raid_disks
, mddev
->new_layout
);
4946 print_raid5_conf(conf
);
4948 if (conf
->reshape_progress
!= MaxSector
) {
4949 conf
->reshape_safe
= conf
->reshape_progress
;
4950 atomic_set(&conf
->reshape_stripes
, 0);
4951 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4952 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4953 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4954 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4955 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4960 /* Ok, everything is just fine now */
4961 if (mddev
->to_remove
== &raid5_attrs_group
)
4962 mddev
->to_remove
= NULL
;
4963 else if (mddev
->kobj
.sd
&&
4964 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
4966 "raid5: failed to create sysfs attributes for %s\n",
4968 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
4972 /* read-ahead size must cover two whole stripes, which
4973 * is 2 * (datadisks) * chunksize where 'n' is the
4974 * number of raid devices
4976 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4977 int stripe
= data_disks
*
4978 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
4979 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4980 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4982 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
4984 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
4985 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
4987 chunk_size
= mddev
->chunk_sectors
<< 9;
4988 blk_queue_io_min(mddev
->queue
, chunk_size
);
4989 blk_queue_io_opt(mddev
->queue
, chunk_size
*
4990 (conf
->raid_disks
- conf
->max_degraded
));
4992 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4993 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
4994 rdev
->data_offset
<< 9);
4999 md_unregister_thread(&mddev
->thread
);
5000 print_raid5_conf(conf
);
5002 mddev
->private = NULL
;
5003 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
5007 static int stop(struct mddev
*mddev
)
5009 struct r5conf
*conf
= mddev
->private;
5011 md_unregister_thread(&mddev
->thread
);
5013 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
5015 mddev
->private = NULL
;
5016 mddev
->to_remove
= &raid5_attrs_group
;
5020 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
5022 struct r5conf
*conf
= mddev
->private;
5025 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
5026 mddev
->chunk_sectors
/ 2, mddev
->layout
);
5027 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
5028 for (i
= 0; i
< conf
->raid_disks
; i
++)
5029 seq_printf (seq
, "%s",
5030 conf
->disks
[i
].rdev
&&
5031 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
5032 seq_printf (seq
, "]");
5035 static void print_raid5_conf (struct r5conf
*conf
)
5038 struct disk_info
*tmp
;
5040 printk(KERN_DEBUG
"RAID conf printout:\n");
5042 printk("(conf==NULL)\n");
5045 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5047 conf
->raid_disks
- conf
->mddev
->degraded
);
5049 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5050 char b
[BDEVNAME_SIZE
];
5051 tmp
= conf
->disks
+ i
;
5053 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5054 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5055 bdevname(tmp
->rdev
->bdev
, b
));
5059 static int raid5_spare_active(struct mddev
*mddev
)
5062 struct r5conf
*conf
= mddev
->private;
5063 struct disk_info
*tmp
;
5065 unsigned long flags
;
5067 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5068 tmp
= conf
->disks
+ i
;
5070 && tmp
->rdev
->recovery_offset
== MaxSector
5071 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5072 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5074 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5077 spin_lock_irqsave(&conf
->device_lock
, flags
);
5078 mddev
->degraded
= calc_degraded(conf
);
5079 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5080 print_raid5_conf(conf
);
5084 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5086 struct r5conf
*conf
= mddev
->private;
5088 int number
= rdev
->raid_disk
;
5089 struct disk_info
*p
= conf
->disks
+ number
;
5091 print_raid5_conf(conf
);
5092 if (rdev
== p
->rdev
) {
5093 if (number
>= conf
->raid_disks
&&
5094 conf
->reshape_progress
== MaxSector
)
5095 clear_bit(In_sync
, &rdev
->flags
);
5097 if (test_bit(In_sync
, &rdev
->flags
) ||
5098 atomic_read(&rdev
->nr_pending
)) {
5102 /* Only remove non-faulty devices if recovery
5105 if (!test_bit(Faulty
, &rdev
->flags
) &&
5106 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5107 !has_failed(conf
) &&
5108 number
< conf
->raid_disks
) {
5114 if (atomic_read(&rdev
->nr_pending
)) {
5115 /* lost the race, try later */
5122 print_raid5_conf(conf
);
5126 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5128 struct r5conf
*conf
= mddev
->private;
5131 struct disk_info
*p
;
5133 int last
= conf
->raid_disks
- 1;
5135 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5138 if (has_failed(conf
))
5139 /* no point adding a device */
5142 if (rdev
->raid_disk
>= 0)
5143 first
= last
= rdev
->raid_disk
;
5146 * find the disk ... but prefer rdev->saved_raid_disk
5149 if (rdev
->saved_raid_disk
>= 0 &&
5150 rdev
->saved_raid_disk
>= first
&&
5151 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5152 disk
= rdev
->saved_raid_disk
;
5155 for ( ; disk
<= last
; disk
++)
5156 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
5157 clear_bit(In_sync
, &rdev
->flags
);
5158 rdev
->raid_disk
= disk
;
5160 if (rdev
->saved_raid_disk
!= disk
)
5162 rcu_assign_pointer(p
->rdev
, rdev
);
5165 print_raid5_conf(conf
);
5169 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5171 /* no resync is happening, and there is enough space
5172 * on all devices, so we can resize.
5173 * We need to make sure resync covers any new space.
5174 * If the array is shrinking we should possibly wait until
5175 * any io in the removed space completes, but it hardly seems
5178 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5179 md_set_array_sectors(mddev
, raid5_size(mddev
, sectors
,
5180 mddev
->raid_disks
));
5181 if (mddev
->array_sectors
>
5182 raid5_size(mddev
, sectors
, mddev
->raid_disks
))
5184 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5185 revalidate_disk(mddev
->gendisk
);
5186 if (sectors
> mddev
->dev_sectors
&&
5187 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5188 mddev
->recovery_cp
= mddev
->dev_sectors
;
5189 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5191 mddev
->dev_sectors
= sectors
;
5192 mddev
->resync_max_sectors
= sectors
;
5196 static int check_stripe_cache(struct mddev
*mddev
)
5198 /* Can only proceed if there are plenty of stripe_heads.
5199 * We need a minimum of one full stripe,, and for sensible progress
5200 * it is best to have about 4 times that.
5201 * If we require 4 times, then the default 256 4K stripe_heads will
5202 * allow for chunk sizes up to 256K, which is probably OK.
5203 * If the chunk size is greater, user-space should request more
5204 * stripe_heads first.
5206 struct r5conf
*conf
= mddev
->private;
5207 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5208 > conf
->max_nr_stripes
||
5209 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5210 > conf
->max_nr_stripes
) {
5211 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5213 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5220 static int check_reshape(struct mddev
*mddev
)
5222 struct r5conf
*conf
= mddev
->private;
5224 if (mddev
->delta_disks
== 0 &&
5225 mddev
->new_layout
== mddev
->layout
&&
5226 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5227 return 0; /* nothing to do */
5229 /* Cannot grow a bitmap yet */
5231 if (has_failed(conf
))
5233 if (mddev
->delta_disks
< 0) {
5234 /* We might be able to shrink, but the devices must
5235 * be made bigger first.
5236 * For raid6, 4 is the minimum size.
5237 * Otherwise 2 is the minimum
5240 if (mddev
->level
== 6)
5242 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5246 if (!check_stripe_cache(mddev
))
5249 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5252 static int raid5_start_reshape(struct mddev
*mddev
)
5254 struct r5conf
*conf
= mddev
->private;
5255 struct md_rdev
*rdev
;
5257 unsigned long flags
;
5259 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5262 if (!check_stripe_cache(mddev
))
5265 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5266 if (!test_bit(In_sync
, &rdev
->flags
)
5267 && !test_bit(Faulty
, &rdev
->flags
))
5270 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5271 /* Not enough devices even to make a degraded array
5276 /* Refuse to reduce size of the array. Any reductions in
5277 * array size must be through explicit setting of array_size
5280 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5281 < mddev
->array_sectors
) {
5282 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5283 "before number of disks\n", mdname(mddev
));
5287 atomic_set(&conf
->reshape_stripes
, 0);
5288 spin_lock_irq(&conf
->device_lock
);
5289 conf
->previous_raid_disks
= conf
->raid_disks
;
5290 conf
->raid_disks
+= mddev
->delta_disks
;
5291 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5292 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5293 conf
->prev_algo
= conf
->algorithm
;
5294 conf
->algorithm
= mddev
->new_layout
;
5295 if (mddev
->delta_disks
< 0)
5296 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5298 conf
->reshape_progress
= 0;
5299 conf
->reshape_safe
= conf
->reshape_progress
;
5301 spin_unlock_irq(&conf
->device_lock
);
5303 /* Add some new drives, as many as will fit.
5304 * We know there are enough to make the newly sized array work.
5305 * Don't add devices if we are reducing the number of
5306 * devices in the array. This is because it is not possible
5307 * to correctly record the "partially reconstructed" state of
5308 * such devices during the reshape and confusion could result.
5310 if (mddev
->delta_disks
>= 0) {
5311 int added_devices
= 0;
5312 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5313 if (rdev
->raid_disk
< 0 &&
5314 !test_bit(Faulty
, &rdev
->flags
)) {
5315 if (raid5_add_disk(mddev
, rdev
) == 0) {
5317 >= conf
->previous_raid_disks
) {
5318 set_bit(In_sync
, &rdev
->flags
);
5321 rdev
->recovery_offset
= 0;
5323 if (sysfs_link_rdev(mddev
, rdev
))
5324 /* Failure here is OK */;
5326 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5327 && !test_bit(Faulty
, &rdev
->flags
)) {
5328 /* This is a spare that was manually added */
5329 set_bit(In_sync
, &rdev
->flags
);
5333 /* When a reshape changes the number of devices,
5334 * ->degraded is measured against the larger of the
5335 * pre and post number of devices.
5337 spin_lock_irqsave(&conf
->device_lock
, flags
);
5338 mddev
->degraded
= calc_degraded(conf
);
5339 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5341 mddev
->raid_disks
= conf
->raid_disks
;
5342 mddev
->reshape_position
= conf
->reshape_progress
;
5343 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5345 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5346 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5347 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5348 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5349 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5351 if (!mddev
->sync_thread
) {
5352 mddev
->recovery
= 0;
5353 spin_lock_irq(&conf
->device_lock
);
5354 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5355 conf
->reshape_progress
= MaxSector
;
5356 spin_unlock_irq(&conf
->device_lock
);
5359 conf
->reshape_checkpoint
= jiffies
;
5360 md_wakeup_thread(mddev
->sync_thread
);
5361 md_new_event(mddev
);
5365 /* This is called from the reshape thread and should make any
5366 * changes needed in 'conf'
5368 static void end_reshape(struct r5conf
*conf
)
5371 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5373 spin_lock_irq(&conf
->device_lock
);
5374 conf
->previous_raid_disks
= conf
->raid_disks
;
5375 conf
->reshape_progress
= MaxSector
;
5376 spin_unlock_irq(&conf
->device_lock
);
5377 wake_up(&conf
->wait_for_overlap
);
5379 /* read-ahead size must cover two whole stripes, which is
5380 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5382 if (conf
->mddev
->queue
) {
5383 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5384 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5386 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5387 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5392 /* This is called from the raid5d thread with mddev_lock held.
5393 * It makes config changes to the device.
5395 static void raid5_finish_reshape(struct mddev
*mddev
)
5397 struct r5conf
*conf
= mddev
->private;
5399 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5401 if (mddev
->delta_disks
> 0) {
5402 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5403 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5404 revalidate_disk(mddev
->gendisk
);
5407 spin_lock_irq(&conf
->device_lock
);
5408 mddev
->degraded
= calc_degraded(conf
);
5409 spin_unlock_irq(&conf
->device_lock
);
5410 for (d
= conf
->raid_disks
;
5411 d
< conf
->raid_disks
- mddev
->delta_disks
;
5413 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
5415 raid5_remove_disk(mddev
, rdev
) == 0) {
5416 sysfs_unlink_rdev(mddev
, rdev
);
5417 rdev
->raid_disk
= -1;
5421 mddev
->layout
= conf
->algorithm
;
5422 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5423 mddev
->reshape_position
= MaxSector
;
5424 mddev
->delta_disks
= 0;
5428 static void raid5_quiesce(struct mddev
*mddev
, int state
)
5430 struct r5conf
*conf
= mddev
->private;
5433 case 2: /* resume for a suspend */
5434 wake_up(&conf
->wait_for_overlap
);
5437 case 1: /* stop all writes */
5438 spin_lock_irq(&conf
->device_lock
);
5439 /* '2' tells resync/reshape to pause so that all
5440 * active stripes can drain
5443 wait_event_lock_irq(conf
->wait_for_stripe
,
5444 atomic_read(&conf
->active_stripes
) == 0 &&
5445 atomic_read(&conf
->active_aligned_reads
) == 0,
5446 conf
->device_lock
, /* nothing */);
5448 spin_unlock_irq(&conf
->device_lock
);
5449 /* allow reshape to continue */
5450 wake_up(&conf
->wait_for_overlap
);
5453 case 0: /* re-enable writes */
5454 spin_lock_irq(&conf
->device_lock
);
5456 wake_up(&conf
->wait_for_stripe
);
5457 wake_up(&conf
->wait_for_overlap
);
5458 spin_unlock_irq(&conf
->device_lock
);
5464 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
5466 struct r0conf
*raid0_conf
= mddev
->private;
5469 /* for raid0 takeover only one zone is supported */
5470 if (raid0_conf
->nr_strip_zones
> 1) {
5471 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5473 return ERR_PTR(-EINVAL
);
5476 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
5477 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
5478 mddev
->dev_sectors
= sectors
;
5479 mddev
->new_level
= level
;
5480 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5481 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5482 mddev
->raid_disks
+= 1;
5483 mddev
->delta_disks
= 1;
5484 /* make sure it will be not marked as dirty */
5485 mddev
->recovery_cp
= MaxSector
;
5487 return setup_conf(mddev
);
5491 static void *raid5_takeover_raid1(struct mddev
*mddev
)
5495 if (mddev
->raid_disks
!= 2 ||
5496 mddev
->degraded
> 1)
5497 return ERR_PTR(-EINVAL
);
5499 /* Should check if there are write-behind devices? */
5501 chunksect
= 64*2; /* 64K by default */
5503 /* The array must be an exact multiple of chunksize */
5504 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5507 if ((chunksect
<<9) < STRIPE_SIZE
)
5508 /* array size does not allow a suitable chunk size */
5509 return ERR_PTR(-EINVAL
);
5511 mddev
->new_level
= 5;
5512 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5513 mddev
->new_chunk_sectors
= chunksect
;
5515 return setup_conf(mddev
);
5518 static void *raid5_takeover_raid6(struct mddev
*mddev
)
5522 switch (mddev
->layout
) {
5523 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5524 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5526 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5527 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5529 case ALGORITHM_LEFT_SYMMETRIC_6
:
5530 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5532 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5533 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5535 case ALGORITHM_PARITY_0_6
:
5536 new_layout
= ALGORITHM_PARITY_0
;
5538 case ALGORITHM_PARITY_N
:
5539 new_layout
= ALGORITHM_PARITY_N
;
5542 return ERR_PTR(-EINVAL
);
5544 mddev
->new_level
= 5;
5545 mddev
->new_layout
= new_layout
;
5546 mddev
->delta_disks
= -1;
5547 mddev
->raid_disks
-= 1;
5548 return setup_conf(mddev
);
5552 static int raid5_check_reshape(struct mddev
*mddev
)
5554 /* For a 2-drive array, the layout and chunk size can be changed
5555 * immediately as not restriping is needed.
5556 * For larger arrays we record the new value - after validation
5557 * to be used by a reshape pass.
5559 struct r5conf
*conf
= mddev
->private;
5560 int new_chunk
= mddev
->new_chunk_sectors
;
5562 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5564 if (new_chunk
> 0) {
5565 if (!is_power_of_2(new_chunk
))
5567 if (new_chunk
< (PAGE_SIZE
>>9))
5569 if (mddev
->array_sectors
& (new_chunk
-1))
5570 /* not factor of array size */
5574 /* They look valid */
5576 if (mddev
->raid_disks
== 2) {
5577 /* can make the change immediately */
5578 if (mddev
->new_layout
>= 0) {
5579 conf
->algorithm
= mddev
->new_layout
;
5580 mddev
->layout
= mddev
->new_layout
;
5582 if (new_chunk
> 0) {
5583 conf
->chunk_sectors
= new_chunk
;
5584 mddev
->chunk_sectors
= new_chunk
;
5586 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5587 md_wakeup_thread(mddev
->thread
);
5589 return check_reshape(mddev
);
5592 static int raid6_check_reshape(struct mddev
*mddev
)
5594 int new_chunk
= mddev
->new_chunk_sectors
;
5596 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5598 if (new_chunk
> 0) {
5599 if (!is_power_of_2(new_chunk
))
5601 if (new_chunk
< (PAGE_SIZE
>> 9))
5603 if (mddev
->array_sectors
& (new_chunk
-1))
5604 /* not factor of array size */
5608 /* They look valid */
5609 return check_reshape(mddev
);
5612 static void *raid5_takeover(struct mddev
*mddev
)
5614 /* raid5 can take over:
5615 * raid0 - if there is only one strip zone - make it a raid4 layout
5616 * raid1 - if there are two drives. We need to know the chunk size
5617 * raid4 - trivial - just use a raid4 layout.
5618 * raid6 - Providing it is a *_6 layout
5620 if (mddev
->level
== 0)
5621 return raid45_takeover_raid0(mddev
, 5);
5622 if (mddev
->level
== 1)
5623 return raid5_takeover_raid1(mddev
);
5624 if (mddev
->level
== 4) {
5625 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5626 mddev
->new_level
= 5;
5627 return setup_conf(mddev
);
5629 if (mddev
->level
== 6)
5630 return raid5_takeover_raid6(mddev
);
5632 return ERR_PTR(-EINVAL
);
5635 static void *raid4_takeover(struct mddev
*mddev
)
5637 /* raid4 can take over:
5638 * raid0 - if there is only one strip zone
5639 * raid5 - if layout is right
5641 if (mddev
->level
== 0)
5642 return raid45_takeover_raid0(mddev
, 4);
5643 if (mddev
->level
== 5 &&
5644 mddev
->layout
== ALGORITHM_PARITY_N
) {
5645 mddev
->new_layout
= 0;
5646 mddev
->new_level
= 4;
5647 return setup_conf(mddev
);
5649 return ERR_PTR(-EINVAL
);
5652 static struct md_personality raid5_personality
;
5654 static void *raid6_takeover(struct mddev
*mddev
)
5656 /* Currently can only take over a raid5. We map the
5657 * personality to an equivalent raid6 personality
5658 * with the Q block at the end.
5662 if (mddev
->pers
!= &raid5_personality
)
5663 return ERR_PTR(-EINVAL
);
5664 if (mddev
->degraded
> 1)
5665 return ERR_PTR(-EINVAL
);
5666 if (mddev
->raid_disks
> 253)
5667 return ERR_PTR(-EINVAL
);
5668 if (mddev
->raid_disks
< 3)
5669 return ERR_PTR(-EINVAL
);
5671 switch (mddev
->layout
) {
5672 case ALGORITHM_LEFT_ASYMMETRIC
:
5673 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
5675 case ALGORITHM_RIGHT_ASYMMETRIC
:
5676 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
5678 case ALGORITHM_LEFT_SYMMETRIC
:
5679 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
5681 case ALGORITHM_RIGHT_SYMMETRIC
:
5682 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
5684 case ALGORITHM_PARITY_0
:
5685 new_layout
= ALGORITHM_PARITY_0_6
;
5687 case ALGORITHM_PARITY_N
:
5688 new_layout
= ALGORITHM_PARITY_N
;
5691 return ERR_PTR(-EINVAL
);
5693 mddev
->new_level
= 6;
5694 mddev
->new_layout
= new_layout
;
5695 mddev
->delta_disks
= 1;
5696 mddev
->raid_disks
+= 1;
5697 return setup_conf(mddev
);
5701 static struct md_personality raid6_personality
=
5705 .owner
= THIS_MODULE
,
5706 .make_request
= make_request
,
5710 .error_handler
= error
,
5711 .hot_add_disk
= raid5_add_disk
,
5712 .hot_remove_disk
= raid5_remove_disk
,
5713 .spare_active
= raid5_spare_active
,
5714 .sync_request
= sync_request
,
5715 .resize
= raid5_resize
,
5717 .check_reshape
= raid6_check_reshape
,
5718 .start_reshape
= raid5_start_reshape
,
5719 .finish_reshape
= raid5_finish_reshape
,
5720 .quiesce
= raid5_quiesce
,
5721 .takeover
= raid6_takeover
,
5723 static struct md_personality raid5_personality
=
5727 .owner
= THIS_MODULE
,
5728 .make_request
= make_request
,
5732 .error_handler
= error
,
5733 .hot_add_disk
= raid5_add_disk
,
5734 .hot_remove_disk
= raid5_remove_disk
,
5735 .spare_active
= raid5_spare_active
,
5736 .sync_request
= sync_request
,
5737 .resize
= raid5_resize
,
5739 .check_reshape
= raid5_check_reshape
,
5740 .start_reshape
= raid5_start_reshape
,
5741 .finish_reshape
= raid5_finish_reshape
,
5742 .quiesce
= raid5_quiesce
,
5743 .takeover
= raid5_takeover
,
5746 static struct md_personality raid4_personality
=
5750 .owner
= THIS_MODULE
,
5751 .make_request
= make_request
,
5755 .error_handler
= error
,
5756 .hot_add_disk
= raid5_add_disk
,
5757 .hot_remove_disk
= raid5_remove_disk
,
5758 .spare_active
= raid5_spare_active
,
5759 .sync_request
= sync_request
,
5760 .resize
= raid5_resize
,
5762 .check_reshape
= raid5_check_reshape
,
5763 .start_reshape
= raid5_start_reshape
,
5764 .finish_reshape
= raid5_finish_reshape
,
5765 .quiesce
= raid5_quiesce
,
5766 .takeover
= raid4_takeover
,
5769 static int __init
raid5_init(void)
5771 register_md_personality(&raid6_personality
);
5772 register_md_personality(&raid5_personality
);
5773 register_md_personality(&raid4_personality
);
5777 static void raid5_exit(void)
5779 unregister_md_personality(&raid6_personality
);
5780 unregister_md_personality(&raid5_personality
);
5781 unregister_md_personality(&raid4_personality
);
5784 module_init(raid5_init
);
5785 module_exit(raid5_exit
);
5786 MODULE_LICENSE("GPL");
5787 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
5788 MODULE_ALIAS("md-personality-4"); /* RAID5 */
5789 MODULE_ALIAS("md-raid5");
5790 MODULE_ALIAS("md-raid4");
5791 MODULE_ALIAS("md-level-5");
5792 MODULE_ALIAS("md-level-4");
5793 MODULE_ALIAS("md-personality-8"); /* RAID6 */
5794 MODULE_ALIAS("md-raid6");
5795 MODULE_ALIAS("md-level-6");
5797 /* This used to be two separate modules, they were: */
5798 MODULE_ALIAS("raid5");
5799 MODULE_ALIAS("raid6");